Radical lymph node dissection and assessment: Impact on gallbladder cancer prognosis

PubMed Central

Liu, Gui-Jie; Li, Xue-Hua; Chen, Yan-Xin; Sun, Hui-Dong; Zhao, Gui-Mei; Hu, San-Yuan

2013-01-01

AIM: To investigate the lymph node metastasis patterns of gallbladder cancer (GBC) and evaluate the optimal categorization of nodal status as a critical prognostic factor. METHODS: From May 1995 to December 2010, a total of 78 consecutive patients with GBC underwent a radical resection at Liaocheng People’s Hospital. A radical resection was defined as removing both the primary tumor and the regional lymph nodes of the gallbladder. Demographic, operative and pathologic data were recorded. The lymph nodes retrieved were examined histologically for metastases routinely from each node. The positive lymph node count (PLNC) as well as the total lymph node count (TLNC) was recorded for each patient. Then the metastatic to examined lymph nodes ratio (LNR) was calculated. Disease-specific survival (DSS) and predictors of outcome were analyzed. RESULTS: With a median follow-up time of 26.50 mo (range, 2-132 mo), median DSS was 29.00 ± 3.92 mo (5-year survival rate, 20.51%). Nodal disease was found in 37 patients (47.44%). DSS of node-negative patients was significantly better than that of node-positive patients (median DSS, 40 mo vs 17 mo, χ2 = 14.814, P < 0.001), while there was no significant difference between N1 patients and N2 patients (median DSS, 18 mo vs 13 mo, χ2 = 0.741, P = 0.389). Optimal TLNC was determined to be four. When node-negative patients were divided according to TLNC, there was no difference in DSS between TLNC < 4 subgroup and TLNC ≥ 4 subgroup (median DSS, 37 mo vs 54 mo, χ2 = 0.715, P = 0.398). For node-positive patients, DSS of TLNC < 4 subgroup was worse than that of TLNC ≥ 4 subgroup (median DSS, 13 mo vs 21 mo, χ2 = 11.035, P < 0.001). Moreover, for node-positive patients, a new cut-off value of six nodes was identified for the number of TLNC that clearly stratified them into 2 separate survival groups (< 6 or ≥ 6, respectively; median DSS, 15 mo vs 33 mo, χ2 = 11.820, P < 0.001). DSS progressively worsened with increasing PLNC and LNR, but no definite cut-off value could be identified. Multivariate analysis revealed histological grade, tumor node metastasis staging, TNLC and LNR to be independent predictors of DSS. Neither location of positive lymph nodes nor PNLC were identified as an independent variable by multivariate analysis. CONCLUSION: Both TLNC and LNR are strong predictors of outcome after curative resection for GBC. The retrieval and examination of at least 6 nodes can influence staging quality and DSS, especially in node-positive patients. PMID:23964151

Radical lymph node dissection and assessment: Impact on gallbladder cancer prognosis.

PubMed

Liu, Gui-Jie; Li, Xue-Hua; Chen, Yan-Xin; Sun, Hui-Dong; Zhao, Gui-Mei; Hu, San-Yuan

2013-08-21

To investigate the lymph node metastasis patterns of gallbladder cancer (GBC) and evaluate the optimal categorization of nodal status as a critical prognostic factor. From May 1995 to December 2010, a total of 78 consecutive patients with GBC underwent a radical resection at Liaocheng People's Hospital. A radical resection was defined as removing both the primary tumor and the regional lymph nodes of the gallbladder. Demographic, operative and pathologic data were recorded. The lymph nodes retrieved were examined histologically for metastases routinely from each node. The positive lymph node count (PLNC) as well as the total lymph node count (TLNC) was recorded for each patient. Then the metastatic to examined lymph nodes ratio (LNR) was calculated. Disease-specific survival (DSS) and predictors of outcome were analyzed. With a median follow-up time of 26.50 mo (range, 2-132 mo), median DSS was 29.00 ± 3.92 mo (5-year survival rate, 20.51%). Nodal disease was found in 37 patients (47.44%). DSS of node-negative patients was significantly better than that of node-positive patients (median DSS, 40 mo vs 17 mo, χ² = 14.814, P < 0.001), while there was no significant difference between N1 patients and N2 patients (median DSS, 18 mo vs 13 mo, χ² = 0.741, P = 0.389). Optimal TLNC was determined to be four. When node-negative patients were divided according to TLNC, there was no difference in DSS between TLNC < 4 subgroup and TLNC ≥ 4 subgroup (median DSS, 37 mo vs 54 mo, χ² = 0.715, P = 0.398). For node-positive patients, DSS of TLNC < 4 subgroup was worse than that of TLNC ≥ 4 subgroup (median DSS, 13 mo vs 21 mo, χ² = 11.035, P < 0.001). Moreover, for node-positive patients, a new cut-off value of six nodes was identified for the number of TLNC that clearly stratified them into 2 separate survival groups (< 6 or ≥ 6, respectively; median DSS, 15 mo vs 33 mo, χ² = 11.820, P < 0.001). DSS progressively worsened with increasing PLNC and LNR, but no definite cut-off value could be identified. Multivariate analysis revealed histological grade, tumor node metastasis staging, TNLC and LNR to be independent predictors of DSS. Neither location of positive lymph nodes nor PNLC were identified as an independent variable by multivariate analysis. Both TLNC and LNR are strong predictors of outcome after curative resection for GBC. The retrieval and examination of at least 6 nodes can influence staging quality and DSS, especially in node-positive patients.

Comparison of prognostic nomograms based on different nodal staging systems in patients with resected gastric cancer.

PubMed

Wang, Zi-Xian; Qiu, Miao-Zhen; Jiang, Yu-Ming; Zhou, Zhi-Wei; Li, Guo-Xin; Xu, Rui-Hua

2017-01-01

Purpose: Previous studies addressing the optimal nodal staging system in patients with resected gastric cancer have shown inconsistent results, and the optimal system for development of prognostic nomograms remains unclear. In this study, we compared prognostic nomograms based on the metastatic lymph node (MLN) count, lymph node ratio (LNR), and log odds of metastatic lymph nodes (LODDS) to predict the 5-year overall survival in patients with resected gastric cancer. Methods: We analysed 15,320 patients with resected gastric cancer in the Surveillance, Epidemiology, and End Results (SEER) database between 1988 and 2010. Missing data were handled using multiple imputation. When assessed as a continuous covariate with restricted cubic splines, each MLN, LNR, and LODDS variable was incorporated into a nomogram with other significant prognosticators to predict the 5-year overall survival. A two-centre Chinese dataset (1,595 cases) was used as external validation data. Results: The discriminatory abilities of the MLN-, LNR-, and LODDS-based nomograms were comparable (concordance indices: 0.744, 0.741, and 0.744, respectively, in the SEER set, P > 0.152 for all pairwise comparisons; 0.715, 0.712, and 0.713, respectively, in the Chinese set, P > 0.445 for all pairwise comparisons). The discriminatory abilities of the three nomograms were all superior to the American Joint Committee on Cancer (AJCC) TNM classification (concordance indices: 0.713, P < 0.001 for all in the SEER set; and 0.693, P < 0.001 for all in the Chinese set). The discriminatory abilities of the nomograms were comparable regardless of the number of nodes examined. Moreover, decision curve analyses indicated similar net benefits of using the nomograms. Conclusion: MLN-, LNR-, and LODDS should be considered equally in the development of multivariate prognostic models and nomograms to refine the prediction of survival among patients with resected gastric cancer.

Lymph nodes ratio based nomogram predicts survival of resectable gastric cancer regardless of the number of examined lymph nodes.

PubMed

Chen, Shangxiang; Rao, Huamin; Liu, Jianjun; Geng, Qirong; Guo, Jing; Kong, Pengfei; Li, Shun; Liu, Xuechao; Sun, Xiaowei; Zhan, Youqing; Xu, Dazhi

2017-07-11

To develop a nomogram to predict the prognosis of gastric cancer patients on the basis of metastatic lymph nodes ratio (mLNR), especially in the patients with total number of examined lymph nodes (TLN) less than 15. The nomogram was constructed based on a retrospective database that included 2,205 patients underwent curative resection in Cancer Center, Sun Yat-sen University (SYSUCC). Resectable gastric cancer (RGC) patients underwent curative resection before December 31, 2008 were assigned as the training set (n=1,470) and those between January 1, 2009 and December 31, 2012 were selected as the internal validation set (n=735). Additional external validations were also performed separately by an independent data set (n=602) from Jiangxi Provincial Cancer Hospital (JXCH) in Jiangxi, China and a data set (n=3,317) from the Surveillance, Epidemiology, and End Results (SEER) database. The Independent risk factors were identified by Multivariate Cox Regression. In the SYSUCC set, TNM (Tumor-node-metastasis) and TRM-based (Tumor-Positive Nodes Ratio-Metastasis) nomograms were constructed respectively. The TNM-based nomogram showed better discrimination than the AJCC-TNM staging system (C-index: 0.73 versus 0.69, p<0.01). When the mLNR was included in the nomogram, the C-index increased to 0.76. Furthermore, the C-index in the TRM-based nomogram was similar between TLN ≥16 (C-index: 0.77) and TLN ≤15 (C-index: 0.75). The discrimination was further ascertained by internal and external validations. We developed and validated a novel TRM-based nomogram that provided more accurate prediction of survival for gastric cancer patients who underwent curative resection, regardless of the number of examined lymph nodes.

What is the most accurate lymph node staging method for perihilar cholangiocarcinoma? Comparison of UICC/AJCC pN stage, number of metastatic lymph nodes, lymph node ratio, and log odds of metastatic lymph nodes.

PubMed

Conci, S; Ruzzenente, A; Sandri, M; Bertuzzo, F; Campagnaro, T; Bagante, F; Capelli, P; D'Onofrio, M; Piccino, M; Dorna, A E; Pedrazzani, C; Iacono, C; Guglielmi, A

2017-04-01

We compared the prognostic performance of the International Union Against Cancer/American Joint Committee on Cancer (UICC/AJCC) 7th edition pN stage, number of metastatic LNs (MLNs), LN ratio (LNR), and log odds of MLNs (LODDS) in patients with perihilar cholangiocarcinoma (PCC) undergoing curative surgery in order to identify the best LN staging method. Ninety-nine patients who underwent surgery with curative intent for PCC in a single tertiary hepatobiliary referral center were included in the study. Two approaches were used to evaluate and compare the predictive power of the different LN staging methods: one based on the estimation of variable importance with prediction error rate and the other based on the calculation of the receiver operating characteristic (ROC) curve. LN dissection was performed in 92 (92.9%) patients; 49 were UICC/AJCC pN0 (49.5%), 33 pN1 (33.3%), and 10 pN2 (10.1%). The median number of LNs retrieved was 8. The prediction error rate ranged from 42.7% for LODDS to 47.1% for UICC/AJCC pN stage. Moreover, LODDS was the variable with the highest area under the ROC curve (AUC) for prediction of 3-year survival (AUC = 0.71), followed by LNR (AUC = 0.60), number of MLNs (AUC = 0.59), and UICC/AJCC pN stage (AUC = 0.54). The number of MLNs, LNR, and LODDS appear to better predict survival than the UICC/AJCC pN stage in patients undergoing curative surgery for PCC. Moreover, LODDS seems to be the most accurate and predictive LN staging method. Copyright © 2017 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.

Evaluation of the Lactate-to-N-Acetyl-aspartate Ratio Defined With Magnetic Resonance Spectroscopic Imaging Before Radiation Therapy as a New Predictive Marker of the Site of Relapse in Patients With Glioblastoma Multiforme

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deviers, Alexandra; UMR; INP

Purpose: Because lactate accumulation is considered a surrogate for hypoxia and tumor radiation resistance, we studied the spatial distribution of the lactate-to-N-acetyl-aspartate ratio (LNR) before radiation therapy (RT) with 3D proton magnetic resonance spectroscopic imaging (3D-{sup 1}H-MRSI) and assessed its impact on local tumor control in glioblastoma (GBM). Methods and Materials: Fourteen patients with newly diagnosed GBM included in a phase 2 chemoradiation therapy trial constituted our database. Magnetic resonance imaging (MRI) and MRSI data before RT were evaluated and correlated to MRI data at relapse. The optimal threshold for tumor-associated LNR was determined with receiver-operating-characteristic (ROC) curve analysis ofmore » the pre-RT LNR values and MRI characteristics of the tumor. This threshold was used to segment pre-RT normalized LNR maps. Two spatial analyses were performed: (1) a pre-RT volumetric comparison of abnormal LNR areas with regions of MRI-defined lesions and a choline (Cho)-to- N-acetyl-aspartate (NAA) ratio ≥2 (CNR2); and (2) a voxel-by-voxel spatial analysis of 4,186,185 voxels with the intention of evaluating whether pre-RT abnormal LNR areas were predictive of the site of local recurrence. Results: A LNR of ≥0.4 (LNR-0.4) discriminated between tumor-associated and normal LNR values with 88.8% sensitivity and 97.6% specificity. LNR-0.4 voxels were spatially different from those of MRI-defined lesions, representing 44% of contrast enhancement, 64% of central necrosis, and 26% of fluid-attenuated inversion recovery (FLAIR) abnormality volumes before RT. They extended beyond the overlap with CNR2 for most patients (median: 20 cm{sup 3}; range: 6-49 cm{sup 3}). LNR-0.4 voxels were significantly predictive of local recurrence, regarded as contrast enhancement at relapse: 71% of voxels with a LNR-0.4 before RT were contrast enhanced at relapse versus 10% of voxels with a normal LNR (P<.01). Conclusions: Pre-RT LNR-0.4 in GBM indicates tumor areas that are likely to relapse. Further investigations are needed to confirm lactate imaging as a tool to define additional biological target volumes for dose painting.« less

Identification of an N staging system that predicts oncologic outcome in resected left-sided pancreatic cancer.

PubMed

Kim, Sung Hyun; Hwang, Ho Kyoung; Lee, Woo Jung; Kang, Chang Moo

2016-06-01

In this study, we investigated which N staging system was the most accurate at predicting survival in pancreatic cancer patients.Lymph node (LN) metastasis is known to be one of the important prognostic factors in resected pancreatic cancer. There are several LN evaluation systems to predict oncologic impact.From January 1992 to December 2014, 77 medical records of patients who underwent radical pancreatectomy for left-sided pancreatic cancer were reviewed retrospectively. Clinicopathologic variables including pN stage, total number of retrieved LNs (N-RLN), lymph node ratio (LNR), and absolute number of LN metastases (N-LNmet) were evaluated. Disease-free survival (DFS) and disease-specific survival (DSS) were analyzed according to these 4 LN staging systems.In univariate analysis, pN stage (pN0 vs pN1: 17.5 months vs 7.9 months, P = 0.001), LNR (<0.08 vs ≥0.08: 17.5 months vs 4.4 months, P < 0.001), and N-LNmet (#N = 0 vs #N = 1 vs #N≥2: 17.5 months vs 11.0 months vs 6.4 months, P = 0.002) had a significant effect on DFS, whereas the pN stage (pN0 vs pN1: 35.3 months vs 16.7 months, P = 0.001), LNR (<0.08 vs ≥0.08: 37.1 months vs 15.0 months, P < 0.001), and N-LNmet (#N = 0 vs #N = 1 vs #N≥2: 35.3 months vs 18.4 months vs 16.4 months, P = 0.001) had a significant effect on DSS. In multivariate analysis, N-LNmet (#N≥2) was identified as an independent prognostic factor of oncologic outcome (DFS and DSS: Exp (β) = 2.83, P = 0.001, and Exp (β) = 3.17, P = 0.001, respectively).Absolute number of lymph node metastases predicted oncologic outcome in resected left-sided pancreatic cancer patients.

Pattern of tumour growth of the primary colon cancer predicts long-term outcome after resection of liver metastases.

PubMed

Spelt, Lidewij; Sasor, Agata; Ansari, Daniel; Andersson, Roland

2016-10-01

To identify significant predictive factors for overall survival (OS) and disease-free survival (DFS) after liver resection for colon cancer metastases, with special focus on features of the primary colon cancer, such as lymph node ratio (LNR), vascular invasion, and perineural invasion. Patients operated for colonic cancer liver metastases between 2006 and 2014 were included. Details on patient characteristics, the primary colon cancer operation and metastatic disease were collected. Multivariate analysis was performed to select predictive variables for OS and DFS. Median OS and DFS were 67 and 20 months, respectively. 1-, 3- and 5-year OS were 97, 76, and 52%. 1-, 3- and 5-year DFS were 65, 42, and 37%. Multivariate analysis showed LNR to be an independent predictive factor for DFS but not for OS. Other identified predictive factors were vascular and perineural invasion of the primary colon cancer, size of the largest metastasis and severe complications after liver surgery for OS, and perineural invasion, number of liver metastases and preoperative CEA-level for DFS. Traditional N-stage was also considered to be an independent predictive factor for DFS in a separate multivariate analysis. LNR and perineural invasion of the primary colon cancer can be used as a prognostic variable for DFS after a concomitant liver resection for colon cancer metastases. Vascular and perineural invasion of the primary colon cancer are predictive for OS.

Development of comprehensive nomograms for evaluating overall and cancer-specific survival of laryngeal squamous cell carcinoma patients treated with neck dissection

PubMed Central

Shi, Xiao; Hu, Wei-ping; Ji, Qing-hai

2017-01-01

Background Neck dissection for laryngeal squamous cell carcinoma (LSCC) patients could provide complementary prognostic information for AJCC N staging, like lymph node ratio (LNR). The aim of this study was to develop effective nomograms to better predict survival for LSCC patients treated with neck dissection. Results 2752 patients were identified and randomly divided into training (n = 2477) and validation (n = 275) cohorts. The 3- and 5-year probabilities of cancer-specific mortality (CSM) were 30.1% and 37.2% while 3- and 5-year death resulting from other causes (DROC) rate were 6.2% and 11.3%, respectively. 13 significant prognostic factors including LNR for overall (OS) and 12 (except race) for CSS were enrolled in the nomograms. Concordance index as a commonly used indicator of predictive performance, showed the nomograms had superiority over the no-LNR models and TNM classification (Training-cohort: OS: 0.713 vs 0.703 vs 0.667, CSS: 0.725 vs 0.713 vs 0.688; Validation-cohort: OS: 0.704 vs 0.690 vs 0.658, cancer-specific survival (CSS): 0.709 vs 0.693 vs 0.672). All calibration plots revealed good agreement between nomogram prediction and actual survival. Materials and Methods We identified LSCC patients undergoing neck dissection diagnosed between 1988 and 2008 from Surveillance, Epidemiology, and End Results (SEER) database. Optimal cutoff points were determined by X-tile program. Cumulative incidence function was used to analyze cancer-specific mortality (CSM) and death resulting from other causes (DROC). Significant predictive factors were used to establish nomograms estimating overall (OS) and cancer-specific survival (CSS). The nomograms were bootstrapped validated both internally and externally. Conclusions Comprehensive nomograms were constructed to predict OS and CSS for LSCC patients treated with neck dissection more accurately. PMID:28430613

Prognostic Relevance of Lymph Node Regression After Neoadjuvant Chemoradiation for Esophageal Cancer.

PubMed

Philippron, Annouck; Bollschweiler, Elfriede; Kunikata, Ayumi; Plum, Patrick; Schmidt, Claudia; Favi, Francesco; Drebber, Uta; Hölscher, Arnulf H

2016-01-01

Prognostic factors after preoperative chemoradiation for patients with advanced esophageal cancer are under discussion. Treatment response measured in the primary tumor is a well-defined prognostic marker. The prognostic relevance of tumor regression in lymph nodes (LNs), eg, histomorphologic characteristics must be evaluated in a larger series of patients. From 1997-2010, 403 patients with cT3N×M0 esophageal cancer underwent preoperative chemoradiation followed by transthoracic esophagectomy. Histopathologic response of the primary tumor was graded in resected specimens as "minor" (≥10% vital residual tumor cells) or "major." The LNs of all patients without LN metastases (ypN0 n = 222, adenocarcinoma n = 129, squamous cell carcinoma n = 93) were reevaluated for central fibrosis. Univariate and multivariate analyses were performed on histomorphologic criteria of examined LNs and used to correlate these with tumor response and prognosis. The 5-year survival rate (5YSR) for all patients was 30%. Overall, 5480 LNs were reevaluated for the existence of central fibrosis in ypN0 cases. The prognostic relevance of the LN regression (LNR) grading system was confirmed for all patients with univariate (P < 0.001) and multivariate (P = 0.02) analyses. In results, the 5YSR for ypN0 patients overall was 37%, for patients with major response by the primary tumor was 42%, and for minor responders was 19% (P < 0.001). Analyzing LNR in major responders, the group with less than 3 LNs with central fibrosis (n = 52) showed significantly better prognosis (5YSR = 63%) compared to those with more (5YSR = 34%), (P = 0.016). Conclusion includes morphologic signs of metastatic LNR after chemoradiation, such as central fibrosis, are of prognostic relevance for patients with advanced esophageal cancer, especially for those with major response of the primary tumor. Copyright © 2016 Elsevier Inc. All rights reserved.

Chemical modifications of liquid natural rubber

NASA Astrophysics Data System (ADS)

Azhar, Nur Hanis Adila; Rasid, Hamizah Md; Yusoff, Siti Fairus M.

2016-11-01

Liquid natural rubber (LNR) was synthesized via photosentisized degradation of natural rubber (NR). LNR was modified into epoxidized liquid natural rubber (LENR) and hydroxylated liquid natural rubber (LNR-OH) using Na2WO4/CH3COOH/H2O2 catalytic system. Chemical structures of LNR and modified LNRs were characterized using Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) and 1H Nuclear Magnetic Resonance (NMR) spectroscopies. Integration of 1H NMR was used to calculate the epoxy content (%) of LENR. 1H NMR detected the formation of LNR-OH after prolonged heating and increased of catalyst in oxidation reaction.

Tensile and morphology properties of PLA/LNR blends modified with maleic anhydride grafted-polylactic acid and -natural rubber

NASA Astrophysics Data System (ADS)

Ruf, Mohd Farid Hakim Mohd; Ahmad, Sahrim; Chen, Ruey Shan; Shahdan, Dalila; Zailan, Farrah Diyana

2018-04-01

This research was carried out to investigate the addition of grafted copolymers of maleic anhydride grafted-polylactic acid(PLA-g-MA) and maleic anhydride grafted-natural rubber (NR-g-MA) on the tensile and morphology properties of polylactic acid/ liquid natural rubber (PLA/LNR) blends. Prior to blend preparation, the PLA-g-MA and NR-g-MA was first self-synthesized using maleic anhydride (MA) and dicumyl peroxide (DCP) as initiator together with the PLA and NR respectively. The PLA/LNR, PLA/LNR/PLA-g-MA and PLA/LNR/NR-g-MA blends were prepared via melt-blending method. The loading of PLA-g-MA and NR-g-MA was varied by 5, 10 and 15 wt% respectively. The addition of PLA-g-MA led to increment in tensile strength with 5 and 10 wt% while NR-g-MA gives lower than controlled sample (PLA/LNR blend). Scanning electron microscope (SEM) showed the interaction of the components in the blends. The PLA/LNR compatibilized with PLA-g-MA and NR-g-MA shows greater dispersion and adhesion.

A new look at the International Duration Evaluation of Adjuvant therapy (IDEA) classification-Defining novel predictive and prognostic markers in stage III colon cancer.

PubMed

Margalit, Ofer; Mamtani, Ronac; Yang, Yu-Xiao; Reiss, Kim A; Golan, Talia; Halpern, Naama; Aderka, Dan; Giantonio, Bruce; Shacham-Shmueli, Einat; Boursi, Ben

2018-04-23

The International Duration Evaluation of Adjuvant therapy (IDEA) pooled analysis compared 3 to 6 months of adjuvant chemotherapy for stage III colon cancer. The overarching goal was to reduce chemotherapy-related toxicity, mainly oxaliplatin-induced neuropathy. Patients were classified into low-risk and high-risk groups, suggesting that low-risk patients may be offered only 3 months of treatment. We aimed to evaluate the benefit of monotherapy versus doublet chemotherapy in low and high IDEA risk groups. Using the National Cancer Database (2004-2014), we identified 56,728 low-risk and 47,557 high-risk individuals with stage III colon cancer, according to the IDEA classification. We used multivariate Cox regression to evaluate the magnitude of survival differences between IDEA risk groups, according to treatment intensity (doublet versus monotherapy). In a secondary analysis, we examined the prognostic and predictive value of subgroups of age, tumour sidedness and lymph node ratio (LNR). Low and high IDEA risk groups derived similar benefit from doublet adjuvant chemotherapy as compared with monotherapy, with hazard ratios (HRs) of 0.83 (95% confidence interval [CI] 0.79-0.86) and 0.80 (95% CI 0.78-0.83), respectively. The only subpopulations that did not benefit from doublet chemotherapy were low-risk patients older than 72 years (HR = 0.95, 95% CI 0.90-1.01) and high-risk patients older than 85 years (HR = 0.90, 95% CI 0.77-1.05). LNR and tumour sidedness were shown as additional prognostic, but not predictive, factors within the IDEA risk groups. IDEA risk classification per se does not predict for treatment benefit from doublet chemotherapy in stage III colon cancer. However, omission of oxaliplatin can be considered in IDEA low-risk patients older than 72 years. Copyright © 2018 Elsevier Ltd. All rights reserved.

COX-2 overexpression in resected pancreatic head adenocarcinomas correlates with favourable prognosis

PubMed Central

2014-01-01

Background Overexpression of cyclooxygenase-2 (COX-2) has been implicated in oncogenesis and progression of adenocarcinomas of the pancreatic head. The data on the prognostic importance of COX expression in these tumours is inconsistent and conflicting. We evaluated how COX-2 overexpression affected overall postoperative survival in pancreatic head adenocarcinomas. Methods The study included 230 consecutive pancreatoduodenectomies for pancreatic cancer (PC, n = 92), ampullary cancer (AC, n = 62) and distal bile duct cancer (DBC, n = 76). COX-2 expression was assessed by immunohistochemistry. Associations between COX-2 expression and histopathologic variables including degree of differentiation, histopathologic type of differentiation (pancreatobiliary vs. intestinal) and lymph node ratio (LNR) were evaluated. Unadjusted and adjusted survival analysis was performed. Results COX-2 staining was positive in 71% of PC, 77% in AC and 72% in DBC. Irrespective of tumour origin, overall patient survival was more favourable in patients with COX-2 positive tumours than COX-2 negative (p = 0.043 in PC, p = 0.011 in AC, p = 0.06 in DBC). In tumours of pancreatobiliary type of histopathological differentiation, COX-2 expression did not significantly affect overall patient survival. In AC with intestinal differentiation COX-2 expression significantly predicted favourable survival (p = 0.003). In PC, COX-2 expression was significantly associated with high degree of differentiation (p = 0.002). COX-2 and LNR independently predicted good prognosis in a multivariate model. Conclusions COX-2 is overexpressed in pancreatic cancer, ampullary cancer and distal bile duct cancer and confers a survival benefit in all three cancer types. In pancreatic cancer, COX-2 overexpression is significantly associated with the degree of differentiation and independently predicts a favourable prognosis. PMID:24950702

Electrospinning of PVC with natural rubber

NASA Astrophysics Data System (ADS)

Othman, Muhammad Hariz; Mohamed, Mahathir; Abdullah, Ibrahim

2013-11-01

Polyvinyl chloride (PVC) was mixed with natural rubbers which are liquid natural rubber (LNR), liquid epoxidised natural rubber (LENR) and liquid epoxidised natural rubber acrylate (LENRA) for a preparation of a fine non-woven fiber's mat. PVC and each natural rubbers(PVC:LENR, PVC:LNR and PVC:LENRA) were mixed based on ratio of 70:30. Electrospinning method was used to prepare the fiber. The results show that the spinnable concentration of PVC/ natural rubber/THF solution is 16 wt%. The morphology, diameter, structure and degradation temperature of electrospun fibers were investigated by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). SEM photos showed that the morphology and diameter of the fibers were mainly affected by the addition of natural rubber. TGA results suggested that PVC electrospun fiber has higher degradation temperature than those electrospun fibers that contain natural rubber.

Electrospinning of PVC with natural rubber

DOE Office of Scientific and Technical Information (OSTI.GOV)

Othman, Muhammad Hariz; Abdullah, Ibrahim; Mohamed, Mahathir

Polyvinyl chloride (PVC) was mixed with natural rubbers which are liquid natural rubber (LNR), liquid epoxidised natural rubber (LENR) and liquid epoxidised natural rubber acrylate (LENRA) for a preparation of a fine non-woven fiber’s mat. PVC and each natural rubbers(PVC:LENR, PVC:LNR and PVC:LENRA) were mixed based on ratio of 70:30. Electrospinning method was used to prepare the fiber. The results show that the spinnable concentration of PVC/ natural rubber/THF solution is 16 wt%. The morphology, diameter, structure and degradation temperature of electrospun fibers were investigated by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). SEM photos showed that the morphologymore » and diameter of the fibers were mainly affected by the addition of natural rubber. TGA results suggested that PVC electrospun fiber has higher degradation temperature than those electrospun fibers that contain natural rubber.« less

Observations on the T lnR term in the quark-antiquark free energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kiskis, J.

1986-06-15

Consider the response of a pure gauge theory at temperature T to an external quark-antiquark pair separated by R. In the confining phase, the leading term in the free energy at large R is sigmaR. A string-model calculation has given T lnR for the next-to-leading term. In this paper, the origin of the T lnR term is considered in a more general context that includes the analog spin model and the lattice gauge theory at strong coupling. The connection with transverse fluctuations is emphasized.

Resource Optimization Scheme for Multimedia-Enabled Wireless Mesh Networks

PubMed Central

Ali, Amjad; Ahmed, Muhammad Ejaz; Piran, Md. Jalil; Suh, Doug Young

2014-01-01

Wireless mesh networking is a promising technology that can support numerous multimedia applications. Multimedia applications have stringent quality of service (QoS) requirements, i.e., bandwidth, delay, jitter, and packet loss ratio. Enabling such QoS-demanding applications over wireless mesh networks (WMNs) require QoS provisioning routing protocols that lead to the network resource underutilization problem. Moreover, random topology deployment leads to have some unused network resources. Therefore, resource optimization is one of the most critical design issues in multi-hop, multi-radio WMNs enabled with multimedia applications. Resource optimization has been studied extensively in the literature for wireless Ad Hoc and sensor networks, but existing studies have not considered resource underutilization issues caused by QoS provisioning routing and random topology deployment. Finding a QoS-provisioned path in wireless mesh networks is an NP complete problem. In this paper, we propose a novel Integer Linear Programming (ILP) optimization model to reconstruct the optimal connected mesh backbone topology with a minimum number of links and relay nodes which satisfies the given end-to-end QoS demands for multimedia traffic and identification of extra resources, while maintaining redundancy. We further propose a polynomial time heuristic algorithm called Link and Node Removal Considering Residual Capacity and Traffic Demands (LNR-RCTD). Simulation studies prove that our heuristic algorithm provides near-optimal results and saves about 20% of resources from being wasted by QoS provisioning routing and random topology deployment. PMID:25111241

Resource optimization scheme for multimedia-enabled wireless mesh networks.

PubMed

Ali, Amjad; Ahmed, Muhammad Ejaz; Piran, Md Jalil; Suh, Doug Young

2014-08-08

Wireless mesh networking is a promising technology that can support numerous multimedia applications. Multimedia applications have stringent quality of service (QoS) requirements, i.e., bandwidth, delay, jitter, and packet loss ratio. Enabling such QoS-demanding applications over wireless mesh networks (WMNs) require QoS provisioning routing protocols that lead to the network resource underutilization problem. Moreover, random topology deployment leads to have some unused network resources. Therefore, resource optimization is one of the most critical design issues in multi-hop, multi-radio WMNs enabled with multimedia applications. Resource optimization has been studied extensively in the literature for wireless Ad Hoc and sensor networks, but existing studies have not considered resource underutilization issues caused by QoS provisioning routing and random topology deployment. Finding a QoS-provisioned path in wireless mesh networks is an NP complete problem. In this paper, we propose a novel Integer Linear Programming (ILP) optimization model to reconstruct the optimal connected mesh backbone topology with a minimum number of links and relay nodes which satisfies the given end-to-end QoS demands for multimedia traffic and identification of extra resources, while maintaining redundancy. We further propose a polynomial time heuristic algorithm called Link and Node Removal Considering Residual Capacity and Traffic Demands (LNR-RCTD). Simulation studies prove that our heuristic algorithm provides near-optimal results and saves about 20% of resources from being wasted by QoS provisioning routing and random topology deployment.

Hydrogenation of liquid natural rubber via diimide reduction in hydrazine hydrate/hydrogen peroxide system

NASA Astrophysics Data System (ADS)

Yusof, Muhammad Jefri Mohd; Jamaluddin, Naharullah; Abdullah, Ibrahim; Yusoff, Siti Fairus M.

2015-09-01

Liquid natural rubber (LNR) with molecular weight of lower than 105 and shorter polymeric chain than natural rubber was prepared. LNR was then hydrogenated via diimide reduction by oxidation of hydrazine hydrate with hydrogen peroxide. The unsaturated units of the rubber were converted into saturated hydrocarbon to strengthen the backbone of the polymer so it was able to resist thermal degradation. The results indicated that hydrogenation degree of the product (HLNR) could be extended to 91.2% conversion under appropriate conditions. The hydrogenated LNR (HLNR) was characterized using Fourier-Transform Infrared (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopy. The physical characteristics of HLNR were analyzed with Termogravimetric Analysis (TGA).

Hydrogenation of liquid natural rubber via diimide reduction in hydrazine hydrate/hydrogen peroxide system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yusof, Muhammad Jefri Mohd; Jamaluddin, Naharullah; Abdullah, Ibrahim

Liquid natural rubber (LNR) with molecular weight of lower than 10{sup 5} and shorter polymeric chain than natural rubber was prepared. LNR was then hydrogenated via diimide reduction by oxidation of hydrazine hydrate with hydrogen peroxide. The unsaturated units of the rubber were converted into saturated hydrocarbon to strengthen the backbone of the polymer so it was able to resist thermal degradation. The results indicated that hydrogenation degree of the product (HLNR) could be extended to 91.2% conversion under appropriate conditions. The hydrogenated LNR (HLNR) was characterized using Fourier-Transform Infrared (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopy. The physical characteristicsmore » of HLNR were analyzed with Termogravimetric Analysis (TGA)« less

Effect of ultrasonic treatment on tensile properties of PLA/LNR/NiZn ferrite nanocomposite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shahdan, Dalila; Ahmad, Sahrim Hj.; Flaifel, Moayad Husein

2013-11-27

The influence of sonication treatment time on the morphological and mechanical properties of LNR/PLA composite impregnated with different filler loadings of NiZn ferrite nanoparticles was investigated. The nanocomposite was prepared using melt blending method with assistance of ultrasonic treatment of 0, 1 and 2 hrs. Structural characterization of the nanocomposites was examined using scanning electron microscopy (SEM) with their elemental composition being confirmed by energy dispersive X-ray spectroscopy (EDX). The tensile properties of LNR/PLA composite treated with different ultrasonication times have improved with increasing magnetic nanofiller signature in the nanocomposite. Further, the optimum sonication time of 1 hr was foundmore » to produce nanocomposite with maximum tensile properties.« less

Depletion of nucleus accumbens dopamine leads to impaired reward and aversion processing in mice: Relevance to motivation pathologies.

PubMed

Bergamini, Giorgio; Sigrist, Hannes; Ferger, Boris; Singewald, Nicolas; Seifritz, Erich; Pryce, Christopher R

2016-10-01

Dopamine (DA) neurotransmission, particularly the ventral tegmental area-nucleus accumbens (VTA-NAcc) projection, underlies reward and aversion processing, and deficient DA function could underlie motivational impairments in psychiatric disorders. 6-hydroxydopamine (6-OHDA) injection is an established method for chronic DA depletion, principally applied in rat to study NAcc DA regulation of reward motivation. Given the increasing focus on studying environmental and genetic regulation of DA function in mouse models, it is important to establish the effects of 6-OHDA DA depletion in mice, in terms of reward and aversion processing. This mouse study investigated effects of 6-OHDA-induced NAcc DA depletion using the operant behavioural test battery of progressive ratio schedule (PRS), learned non-reward (LNR), learned helplessness (LH), treadmill, and in addition Pavlovian fear conditioning. 6-OHDA NAcc DA depletion, confirmed by ex vivo HPLC-ED, reduced operant responding: for gustatory reward under effortful conditions in the PRS test; to a stimulus recently associated with gustatory non-reward in the LNR test; to escape footshock recently experienced as uncontrollable in the LH test; and to avoid footshock by physical effort in the treadmill test. Evidence for specificity of effects to NAcc DA was provided by lack of effect of medial prefrontal cortex DA depletion in the LNR and LH tests. These findings add significantly to the evidence that NAcc DA is a major regulator of behavioural responding, particularly at the motivational level, to both reward and aversion. They demonstrate the suitability of mouse models for translational study of causation and reversal of pathophysiological DA function underlying motivation psychopathologies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Thermal properties of hydrogenated liquid natural rubber

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jamaluddin, Naharullah; Abdullah, Ibrahim; Yusoff, Siti Fairus M.

Natural rubber (NR) was modified to form liquid natural rubber (LNR) via photooxidative degradation. Hydrogenated liquid natural rubber (HLNR) was synthesized by using diimide as source of hydrogen which the diimide is produced by thermolysis of p-toluenesulfonyl hydrazide (TSH). The structure of HLNR was characterized by determining the changes of main peaks in Fourier Transform infrared and nuclear magnetic resonance spectra after hydrogenation. Thermogravimetric analysis showed that the HLNR had higher decomposition temperature compared to LNR and the decomposition temperature is directly proportional to the percentage of conversion.

Thermal properties of hydrogenated liquid natural rubber

NASA Astrophysics Data System (ADS)

Jamaluddin, Naharullah; Abdullah, Ibrahim; Yusoff, Siti Fairus M.

2015-09-01

Natural rubber (NR) was modified to form liquid natural rubber (LNR) via photooxidative degradation. Hydrogenated liquid natural rubber (HLNR) was synthesized by using diimide as source of hydrogen which the diimide is produced by thermolysis of p-toluenesulfonyl hydrazide (TSH). The structure of HLNR was characterized by determining the changes of main peaks in Fourier Transform infrared and nuclear magnetic resonance spectra after hydrogenation. Thermogravimetric analysis showed that the HLNR had higher decomposition temperature compared to LNR and the decomposition temperature is directly proportional to the percentage of conversion.

Less than 12 lymph nodes in the surgical specimen after neoadjuvant chemo-radiotherapy: an indicator of tumor regression in locally advanced rectal cancer?

PubMed Central

Gurawalia, Jaiprakash; Nayak, Sandeep P.; Kurpad, Vishnu; Pandey, Arun

2016-01-01

Background The number of lymph node retrieved in the surgical specimen is important for tumor staging and has paramount impact on prognosis in colorectal cancer and imitates the adequacy of lymph node surgical clearance. The paucity of lymph node yields in patients undergoing resection after preoperative chemo radiotherapy (CRT) in rectal cancer has seen. Lower total number of lymph nodes in the total mesoractal excision (TME) specimen after CRT, could a marker of better tumor response. Methods We retrospectively reviewed the prospectively managed data of patients underwent excision for rectal cancer, who treated by neoadjuvant radiotherapy with or without chemotherapy in locally advanced rectal cancer. From 2010 to 2014, 364 patients underwent rectal cancer surgery, of which ninety-one treated with neoadjuvant treatment. Standard surgical and pathological protocols were followed. Patients were categorized into two groups based on the number of total harvested lymph nodes with group 1, having 12 or more nodes harvested, and group 2 including patients who had <12 lymph nodes harvested. The total number of lymph nodes retrieved from the surgical specimen was correlated with grade of tumor regression with neoadjuvant treatment. Results Out of 91 patients, 38 patients (42%) had less than 12 lymph nodes examined in specimen. The difference in median number of lymph nodes was observed significantly as 9 (range, 2–11) versus 16 (range, 12–32), in group 2 and 1, respectively (P<0.01). Patients with fewer lymph node group were comparable with respect to age, BMI, pre-operative staging, neoadjuvant treatment. Pathological complete response in tumor pCR was seen with significantly higher rate (40% vs. 26%, P<0.05) in group 2. As per Mandard criteria, there was significant difference in tumor regression grade (TRG) between both the groups (P<0.05). Among patients with metastatic lymph nodes, median LNR was lower in <12 lymph nodes group at 0.167 (range, 0.09–0.45) versus 0.187 (range, 0.05–0.54), difference was not statistically significant (P=0.81). Conclusions Retrieval of fewer than 12 lymph nodes in surgical specimen of rectal cancer who had received neo-adjuvant radiotherapy with or without chemotherapy should be considered as a good indicator of tumor response with better local disease control, and a good prognostic factor, rather than as a pointer of poor diligence of the surgical and pathological assessment. PMID:28078118

The abundance and diversity of legume-nodulating rhizobia in 28-year-old plantations of tropical, subtropical, and exotic tree species: a case study from the Forest Reserve of Bandia, Senegal.

PubMed

Sene, Godar; Thiao, Mansour; Samba-Mbaye, Ramatoulaye; Khasa, Damase; Kane, Aboubacry; Mbaye, Mame Samba; Beaulieu, Marie-Ève; Manga, Anicet; Sylla, Samba Ndao

2013-01-01

Several fast-growing and multipurpose tree species have been widely used in West Africa to both reverse the tendency of land degradation and restore soil productivity. Although beneficial effects have been reported on soil stabilization, there still remains a lack of information about their impact on soil microorganisms. Our investigation has been carried out in exotic and native tree plantations of 28 years and aimed to survey and compare the abundance and genetic diversity of natural legume-nodulating rhizobia (LNR). The study of LNR is supported by the phylogenetic analysis which clustered the isolates into three genera: Bradyrhizobium, Mesorhizobium, and Sinorhizobium. The results showed close positive correlations between the sizes of LNR populations estimated both in the dry and rainy seasons and the presence of legume tree hosts. There were significant increases in Rhizobium spp. population densities in response to planting with Acacia spp., and high genetic diversities and richness of genotypes were fittest in these tree plantations. This suggests that enrichment of soil Rhizobium spp. populations is host specific. The results indicated also that species of genera Mesorhizobium and Sinorhizobium were lacking in plantations of non-host species. By contrast, there was a widespread distribution of Bradyrhizobium spp. strains across the tree plantations, with no evident specialization in regard to plantation type. Finally, the study provides information about the LNR communities associated with a range of old tree plantations and some aspects of their relationships to soil factors, which may facilitate the management of man-made forest systems that target ecosystem rehabilitation and preservation of soil biota.

[Value of quantitative iodine-based material decomposition images with gemstone spectral CT imaging in the follow-up of patients with hepatocellular carcinoma after TACE treatment].

PubMed

Xing, Gusheng; Wang, Shuang; Li, Chenrui; Zhao, Xinming; Zhou, Chunwu

2015-03-01

To investigate the value of quantitative iodine-based material decomposition images with gemstone spectral CT imaging in the follow-up of patients with hepatocellular carcinoma (HCC) after transcatheter arterial chemoebolization (TACE). Consecutive 32 HCC patients with previous TACE treatment were included in this study. For the follow-up, arterial phase (AP) and venous phase (VP) dual-phase CT scans were performed with a single-source dual-energy CT scanner (Discovery CT 750HD, GE Healthcare). Iodine concentrations were derived from iodine-based material-decomposition images in the liver parenchyma, tumors and coagulation necrosis (CN) areas. The iodine concentration difference (ICD) between the arterial-phase (AP) and venal-phase (VP) were quantitatively evaluated in different tissues.The lesion-to-normal parenchyma iodine concentration ratio (LNR) was calculated. ROC analysis was performed for the qualitative evaluation, and the area under ROC (Az) was calculated to represent the diagnostic ability of ICD and LNR. In all the 32 HCC patients, the region of interesting (ROI) for iodine concentrations included liver parenchyma (n=42), tumors (n=28) and coagulation necrosis (n=24). During the AP the iodine concentration of CNs (median value 0.088 µg/mm(3)) appeared significantly higher than that of the tumors (0.064 µg/mm(3), P=0.022) and liver parenchyma (0.048 µg/mm(3), P=0.005). But it showed no significant difference between liver parenchyma and tumors (P=0.454). During the VP the iodine concentration in hepatic parenchyma (median value 0.181 µg/mm(3)) was significantly higher than that in CNs (0.140 µg/mm(3), P=0.042). There was no significant difference between liver parenchyma and tumors, CNs and tumors (both P>0.05). The median value of ICD in CNs was 0.006 µg/mm(3), significantly lower than that of the HCC (0.201 µg/mm(3), P<0.001) and hepatic parenchyma (0.117 µg/mm(3), P<0.001). The ICDs in tumors and hepatic parenchyma showed no significant difference (P=0.829). During the AP, the LNR had no significant difference between CNs and tumors (a median value 1.805 vs. 1.310, P=0.389), and during the VP, the difference was also non-significant (the median value 0.647 vs. 0.713, P=0.660). The mean Az value of ICDs for evaluation of surviving tumor tissues was 0.804, whiles LNR measured a disappointing result in both AV images and VP images. Quantitative iodine-based material decomposition images with gemstone spectral CT imaging can improve the diagnostic efficacy of CT imaging for HCC patients after TACE treatment.

Mechanical performance of hybrid polyester composites reinforced Cloisite 30B and kenaf fibre

NASA Astrophysics Data System (ADS)

Bonnia, N. N.; Surip, S. N.; Ratim, S.; Mahat, M. M.

2012-06-01

Hybridization of rubber toughened polyester-kenaf nanocomposite was prepared by adding various percentage of kenaf fiber with 4% Cloisite 30B in unsaturated polyester resin. Composite were prepared by adding filler to modified polyester resin subsequently cross-linked using methyl ethyl ketone peroxide and the accelerator cobalt octanoate 1%. Three per hundred rubbers (phr) of liquid natural rubber (LNR) were added in producing this composite. This composite expected to be applied in the interior of passenger cars and truck cabins. This is a quality local product from a combination of good properties polyester and high performance natural fiber, kenaf that is suitable for many applications such as in automotive sector and construction sector. The mechanical and thermal properties of composite were characterized using Durometer Shore-D hardness test, Izod impact test, Scanning electron microscopy, thermogravimetry (TGA) and differential scanning calorimetry (DSC). Result shows that addition of LNR give good properties on impact, flexural and hardness compare to without LNR composite. DSC curve shows that all composition of composites is fully cured and good in thermal properties. Addition of higher percentage of kenaf will lead the composite to elastic behavior and decrease the toughened properties of the composite. Hybrid system composite showed the flexural properties within the flexural properties of kenaf - polyester and Cloisite 30B.

Molecular Physiology of Root System Architecture in Model Grasses

NASA Astrophysics Data System (ADS)

Hixson, K.; Ahkami, A. H.; Anderton, C.; Veličković, D.; Myers, G. L.; Chrisler, W.; Lindenmaier, R.; Fang, Y.; Yabusaki, S.; Rosnow, J. J.; Farris, Y.; Khan, N. E.; Bernstein, H. C.; Jansson, C.

2017-12-01

Unraveling the molecular and physiological mechanisms involved in responses of Root System Architecture (RSA) to abiotic stresses and shifts in microbiome structure is critical to understand and engineer plant-microbe-soil interactions in the rhizosphere. In this study, accessions of Brachypodium distachyon Bd21 (C3 model grass) and Setaria viridis A10.1 (C4 model grass) were grown in phytotron chambers under current and elevated CO2 levels. Detailed growth stage-based phenotypic analysis revealed different above- and below-ground morphological and physiological responses in C3 and C4 grasses to enhanced CO2 levels. Based on our preliminary results and by screening values of total biomass, water use efficiency, root to shoot ratio, RSA parameters and net assimilation rates, we postulated a three-phase physiological mechanism, i.e. RootPlus, BiomassPlus and YieldPlus phases, for grass growth under elevated CO2 conditions. Moreover, this comprehensive set of morphological and process-based observations are currently in use to develop, test, and calibrate biophysical whole-plant models and in particular to simulate leaf-level photosynthesis at various developmental stages of C3 and C4 using the model BioCro. To further link the observed phenotypic traits at the organismal level to tissue and molecular levels, and to spatially resolve the origin and fate of key metabolites involved in primary carbohydrate metabolism in different root sections, we complement root phenotypic observations with spatial metabolomics data using mass spectrometry imaging (MSI) methods. Focusing on plant-microbe interactions in the rhizosphere, six bacterial strains with plant growth promoting features are currently in use in both gel-based and soil systems to screen root growth and development in Brachypodium. Using confocal microscopy, GFP-tagged bacterial systems are utilized to study the initiation of different root types of RSA, including primary root (PR), coleoptile node axile root (CNR) and leaf node axile root (LNR) during developmental stages of root formation. The root exudates also will be quantified and preliminary data will be used to engineer our microbial consortium to improve plant growth.

Magnetic and microwave absorbing properties of magnetite-thermoplastic natural rubber nanocomposites

NASA Astrophysics Data System (ADS)

Kong, Ing; Hj Ahmad, Sahrim; Hj Abdullah, Mustaffa; Hui, David; Nazlim Yusoff, Ahmad; Puryanti, Dwi

2010-11-01

Magnetic and microwave absorbing properties of thermoplastic natural rubber (TPNR) filled magnetite (Fe 3O 4) nanocomposites were investigated. The TPNR matrix was prepared from polypropylene (PP), natural rubber (NR) and liquid natural rubber (LNR) in the ratio of 70:20:10 with the LNR as the compatibilizer. TPNR-Fe 3O 4 nanocomposites with 4-12 wt% Fe 3O 4 as filler were prepared via a Thermo Haake internal mixer using a melt-blending method. XRD reveals the presence of cubic spinel structure of Fe 3O 4 with the lattice parameter of a=8.395 Å. TEM micrograph shows that the Fe 3O 4 nanoparticles are almost spherical with the size ranging 20-50 nm. The values of saturation magnetization ( MS), remanence ( MR), initial magnetic susceptibility ( χi) and initial permeability ( μi) increase, while the coercivity ( HC) decreases with increasing filler content for all compositions. For nanocomposites, the values of the real ( ɛr') and imaginary permittivity ( ɛr'') and imaginary permeability ( μr'') increase, while the value of real permeability ( μr') decreases as the filler content increases. The absorption or minimum reflection loss ( RL) continuously increases and the dip shifts to a lower frequency region with the increasing of both filler content in nanocomposites and the sample thickness. The RL is -25.51 dB at 12.65 GHz and the absorbing bandwidth in which the RL is less than -10 dB is 2.7 GHz when the filler content is 12 wt% at 9 mm sample thickness.

Hierarchical Feature Extraction With Local Neural Response for Image Recognition.

PubMed

Li, Hong; Wei, Yantao; Li, Luoqing; Chen, C L P

2013-04-01

In this paper, a hierarchical feature extraction method is proposed for image recognition. The key idea of the proposed method is to extract an effective feature, called local neural response (LNR), of the input image with nontrivial discrimination and invariance properties by alternating between local coding and maximum pooling operation. The local coding, which is carried out on the locally linear manifold, can extract the salient feature of image patches and leads to a sparse measure matrix on which maximum pooling is carried out. The maximum pooling operation builds the translation invariance into the model. We also show that other invariant properties, such as rotation and scaling, can be induced by the proposed model. In addition, a template selection algorithm is presented to reduce computational complexity and to improve the discrimination ability of the LNR. Experimental results show that our method is robust to local distortion and clutter compared with state-of-the-art algorithms.

Automation of experiments at Dubna Gas-Filled Recoil Separator

NASA Astrophysics Data System (ADS)

Tsyganov, Yu. S.

2016-01-01

Approaches to solving the problems of automation of basic processes in long-term experiments in heavy ion beams of the Dubna Gas-Filled Recoil Separator (DGFRS) facility are considered. Approaches in the field of spectrometry, both of rare α decays of superheavy nuclei and those for constructing monitoring systems to provide accident-free experiment running with highly radioactive targets and recording basic parameters of experiment, are described. The specific features of Double Side Silicon Strip Detectors (DSSSDs) are considered, special attention is paid to the role of boundary effects of neighboring p-n transitions in the "active correlations" method. An example of an off-beam experiment attempting to observe Zeno effect is briefly considered. Basic examples for nuclear reactions of complete fusion at 48Ca ion beams of U-400 cyclotron (LNR, JINR) are given. A scenario of development of the "active correlations" method for the case of very high intensity beams of heavy ions at promising accelerators of LNR, JINR, is presented.

Occult lymph node metastasis and risk of regional recurrence in papillary thyroid cancer after bilateral prophylactic central neck dissection: A multi-institutional study.

PubMed

Lee, Young Chan; Na, Se Young; Park, Gi Cheol; Han, Ju Hyun; Kim, Seung Woo; Eun, Young Gyu

2017-02-01

The impact of occult lymph node metastasis on regional recurrence after prophylactic central neck dissection for preoperative, nodal-negative papillary thyroid cancer is controversial. We investigated risk factors for regional lymph node recurrence in papillary thyroid cancer patients who underwent total thyroidectomy and bilateral prophylactic central neck dissection. Analysis was according to clinicopathologic characteristics and occult lymph node metastasis patterns. This multicenter study enrolled 211 consecutive patients who underwent total thyroidectomy with bilateral prophylactic central neck dissection for papillary thyroid cancer without evidence of central lymph node metastasis on preoperative imaging. Clinicopathologic features and central lymph node metastasis patterns were analyzed for predicting regional recurrence. Multivariate Cox regression analysis was used to identify independent factors for recurrence. Median follow-up time was 43 months (24-95 months). Ten patients (4.7%) showed regional lymph node recurrence. The estimated 5-year, regional recurrence-free survival was 95.2%. Tumor size ≥1 cm, central lymph node metastasis, lymph node ratio, and prelaryngeal lymph node metastasis were associated with regional recurrence in univariate analysis (P < .05). In multivariate analysis, a lymph node ratio ≥ 0.26 was a significant risk factor for regional lymph node recurrence (odds ratio = 11.63, P = .003). Lymph node ratio ≥ 0.26 was an independent predictor of worse recurrence-free survival on Cox regression analysis (hazard ratio = 11.49, P = .002). Although no significant association was observed between the presence of occult lymph node metastasis and regional recurrence, lymph node ratio ≥ 0.26 was an independent predictor of regional lymph node recurrence in papillary thyroid cancer patients who underwent total thyroidectomy and bilateral prophylactic central neck dissection. Copyright © 2016 Elsevier Inc. All rights reserved.

Insights into Autoregulation of Notch3 from Structural and Functional Studies of Its Negative Regulatory Region.

PubMed

Xu, Xiang; Choi, Sung Hee; Hu, Tiancen; Tiyanont, Kittichoat; Habets, Roger; Groot, Arjan J; Vooijs, Marc; Aster, Jon C; Chopra, Rajiv; Fryer, Christy; Blacklow, Stephen C

2015-07-07

Notch receptors are transmembrane proteins that undergo activating proteolysis in response to ligand stimulation. A negative regulatory region (NRR) maintains receptor quiescence by preventing protease cleavage prior to ligand binding. We report here the X-ray structure of the NRR of autoinhibited human Notch3, and compare it with the Notch1 and Notch2 NRRs. The overall architecture of the autoinhibited conformation, in which three LIN12-Notch repeat (LNR) modules wrap around a heterodimerization domain, is preserved in Notch3, but the autoinhibited conformation of the Notch3 NRR is less stable. The Notch3 NRR uses a highly conserved surface on the third LNR module to form a dimer in the crystal. Similar homotypic interfaces exist in Notch1 and Notch2. Together, these studies reveal distinguishing structural features associated with increased basal activity of Notch3, demonstrate increased ligand-independent signaling for disease-associated mutations that map to the Notch3 NRR, and identify a conserved dimerization interface present in multiple Notch receptors. Copyright © 2015 Elsevier Ltd. All rights reserved.

Prognostic value of total number of lymph nodes retrieved differs between left-sided colon cancer and right-sided colon cancer in stage III patients with colon cancer.

PubMed

Yang, Lin; Xiong, Zhenchong; Xie, Qiankun; He, Wenzhuo; Liu, Shousheng; Kong, Pengfei; Jiang, Chang; Guo, Guifang; Xia, Liangping

2018-05-11

The consensus is that a minimum of 12 lymph nodes should be analyzed at colectomy for colon cancer. However, right colon cancer and left colon cancer have different characteristics, and this threshold value for total number of lymph nodes retrieved may not be universally applicable. The data of 63,243 patients with colon cancer treated between 2004 and 2012 were retrieved from the National Cancer Institute's Surveillance, Epidemiology, and End Results database. Multivariate Cox regression analysis was used to determine the predictive value of total number of lymph nodes for survival after adjusting for lymph nodes ratio. The predictive value in left-sided colon cancer and right-sided colon cancer was compared. The optimal total number of lymph nodes cutoff value for prediction of overall survival was identified using the online tool Cutoff Finder. Survival of patients with high total number of lymph nodes (≥12) and low total number of lymph nodes (< 12) was compared by Kaplan-Meier analysis. After stratifying by lymph nodes ratio status, total number of lymph nodes≥12 remained an independent predictor of survival in the whole cohort and in right-sided colon cancer, but not in left-sided colon cancer. The optimal cutoff value for total number of lymph nodes was determined to be 11. Low total number of lymph nodes (< 11) was associated with significantly poorer survival after adjusting for lymph nodes ratio in all subgroups except in the subgroup with high lymph nodes ratio (0.5-1.0). Previous reports of the prognostic significance of total number of lymph nodes on node-positive colon cancer were confounded by lymph nodes ratio. The 12-node standard for total number of lymph nodes may not be equally applicable in right-sided colon cancer and left-sided colon cancer.

Importance of Metastatic Lymph Node Ratio in Non-Metastatic, Lymph Node-Invaded Colon Cancer: A Clinical Trial

PubMed Central

Isik, Arda; Peker, Kemal; Firat, Deniz; Yilmaz, Bahri; Sayar, Ilyas; Idiz, Oguz; Cakir, Coskun; Demiryilmaz, Ismail; Yilmaz, Ismayil

2014-01-01

Background The aim of this study was to evaluate the prognostic importance of the metastatic lymph node ratio for stage III colon cancer patients and to find a cut-off value at which the overall survival and disease-free survival change. Material/Methods Patients with pathological stage III colon cancer were retrospectively evaluated for: age; preoperative values of Crp, Cea, Ca 19-9, and Afp; pathologic situation of vascular, perineural, lymphatic, and serosal involvement; and metastatic lymph node ratio values were calculated. Results The study included 58 stage III colon cancer patients: 20 (34.5%) females and 38 (65.5%) males were involved in the study. Multivariate analysis was applied to the following variables to evaluate significance for overall survival and disease-free survival: age, Crp, Cea, perineural invasion, and metastatic lymph node ratio. The metastatic lymph node ratio (<0.25 or ≥0.25) is the only independent variable significant for overall and disease-free survival. Conclusions Metastatic lymph node ratio is an ideal prognostic marker for stage III colon cancer patients, and 0.25 is the cut-off value for prognosis. PMID:25087904

Lymph node ratio as a prognostic factor in metastatic cutaneous head and neck squamous cell carcinoma.

PubMed

Vasan, Kartik; Low, Tsu-Hui Hubert; Gupta, Ruta; Ashford, Bruce; Asher, Rebecca; Gao, Kan; Ch'ng, Sydney; Palme, Carsten E; Clark, Jonathan R

2018-05-01

The prognostic impact of the size and number of nodal metastases in head and neck cutaneous squamous cell carcinoma (SCC) is well established. The purpose of this study was to validate the prognostic significance of the lymph node ratio in metastatic head and neck cutaneous SCC. A retrospective review of 326 patients with head and neck cutaneous SCC with parotid and/or cervical nodal metastases was performed. The primary endpoints were overall survival (OS) and disease-free survival (DFS). The minimal-P approach was used to investigate the optimal lymph node ratio threshold. Our data included 77 recurrences and 101 deaths. A lymph node ratio of 6% was a significant predictor of shorter DFS (hazard ratio [HR] 1.62; 95% confidence interval [CI] 1.11-2.38; P = .01) and OS (HR 1.63; 95% CI 1.03-2.58; P = 0.04) on multivariable analysis. The lymph node ratio is an independent prognosticator of survival outcomes in patients presenting with metastatic head and neck cutaneous SCC. A lymph node ratio >6% is a significant threshold to categorize patients into low and high risk. © 2018 Wiley Periodicals, Inc.

[Risk factors of non-sentinel lymph node metastasis in breast cancer patients with positive sentinel lymph node ≤ 2].

PubMed

Gao, Yajun; He, Yingjian; Fan, Zhaoqing; Ouyang, Tao

2014-08-13

To explore retrospectively the risk factors of non-sentinel lymph node (NSLN) metastasis in breast cancer patients with sentinel lymph node metastasis ≤ 2 and examine the likelihood of non-sentinel lymph node prediction. A sentinel lymph node biopsy database containing 455 breast cancer patients admitted between July 2005 and February 2012 at Beijing Cancer Hospital was analyzed retrospectively. The patients had ≤ 2 positive sentinel lymph node and complete axillary lymph node dissection. The SLNS⁺/SLNS ratio (P = 0.001), histological grade (P = 0.075), size of mass (P = 0.023) and onset age (P = 0.074) were correlated with NSLN metastases. Only SLNS⁺/SLNS (OR 0.502 95% CI 0.322-0.7844) , histological grade ratio (histological grade ratio II, III and others vs grade I OR 2.696, 2.102, 3.662) were significant independent predictors for NSLN metastases . The ROC value was 0.62 (0.56, 0.68). For ≤ 2 positive sentinel lymph nodes of breast cancer, ratio of SLNS⁺/SLNS and histological grading are independent factors affecting NSLN metastases. However, the results remain unsatisfactory for predicting the status of NSLN.

Comparison of four staging systems of lymph node metastasis in gastric cancer.

PubMed

Zhang, Ming; Zhu, Guanyu; Ma, Yan; Xue, Yingwei

2009-11-01

The classification of lymph node metastasis in patients with gastric cancer is still controversial. Our aim was to evaluate the relative merits of four staging systems of lymph node metastasis. In our study, the nodal status was classified according to the 5th edition of the tumor node metastasis (TNM) system, the Japanese Classification of Gastric Carcinoma (JCGC), the ratio of metastatic lymph nodes, and the size of the largest metastatic lymph node. Each staging system was scored as good (+2), fair (+1), or poor (0) with respect to the theoretical value (extent of the anatomical lymphatic tumor spread), convenience (simplicity), surgical applicability (extent of lymph node dissection), and prognostic value (ability to predict survival rate). In the multivariate analysis including the four staging systems and other potential prognostic factors, stepwise Cox regression revealed that the ratio of metastatic lymph nodes was the most independent prognostic factor. The TNM, ratio, and size systems were convenient because they had no consideration for the location of the tumor and lymph node. Although the JCGC system had advantages in theoretical value and surgical application, it was most optional due to the complexity of the system. Although all different staging systems are comparable, the metastatic lymph node ratio system is convenient, reproducible, and has the highest ability to predict survival.

Preoperative serum C-reactive protein levels and post-operative lymph node ratio are important predictors of survival after pancreaticoduodenectomy for pancreatic ductal adenocarcinoma.

PubMed

Sanjay, Pandanaboyana; de Figueiredo, Rodrigo S; Leaver, Heather; Ogston, Simon; Kulli, Christoph; Polignano, Francesco M; Tait, Iain S

2012-03-10

There is paucity of data on the prognostic value of pre-operative inflammatory response and post-operative lymph node ratio on patient survival after pancreatic-head resection for pancreatic ductal adenocarcinoma. To evaluate the role of the preoperative inflammatory response and postoperative pathology criteria to identify predictive and/or prognostic variables for pancreatic ductal adenocarcinoma. All patients who underwent pancreaticoduodenectomy for pancreatic ductal adenocarcinoma between 2002 and 2008 were reviewed retrospectively. The following impacts on patient survival were assessed: i) preoperative serum CRP levels, white cell count, neutrophil count, neutrophil/lymphocyte ratio, lymphocyte count, platelet/lymphocyte ratio; and ii) post-operative pathology criteria including lymph node status and lymph node ratio. Fifty-one patients underwent potentially curative resection for pancreatic ductal adenocarcinoma during the study period. An elevated preoperative CRP level (greater than 3 mg/L) was found to be a significant adverse prognostic factor (P=0.015) predicting a poor survival, whereas white cell count (P=0.278), neutrophil count (P=0.850), neutrophil/lymphocyte ratio (P=0.272), platelet/lymphocyte ratio (P=0.532) and lymphocyte count (P=0.721) were not significant prognosticators at univariate analysis. Presence of metastatic lymph nodes did not adversely affect survival (P=0.050), however a raised lymph node ratio predicted poor survival at univariate analysis (P<0.001). The preoperative serum CRP level retained significance at multivariate analysis (P=0.011), together with lymph node ratio (P<0.001) and tumour size (greater than 2 cm; P=0.008). A pre-operative elevated serum CRP level and raised post-operative lymph node ratio represent significant independent prognostic factors that predict poor prognosis in patients undergoing curative resection for pancreatic ductal adenocarcinoma. There is potential for future neo-adjuvant and adjuvant treatment strategies in pancreatic cancer to be tailored based on preoperative and postoperative factors that predict a poor survival.

Ratio of metastatic lymph nodes to total number of nodes resected is prognostic for survival in esophageal carcinoma.

PubMed

Kelty, Clive J; Kennedy, Catherine W; Falk, Gregory L

2010-09-01

The role of the number of metastatic nodes in esophageal cancer surgery is of interest. We assess predictors of survival after oesophagectomy for esophageal and gastroesophageal junction malignancy. Prospective data of consecutive patients undergoing oesophagectomy and systematic lymphadenectomy between 1991 and 2007. Of 224 patients, 148 patients (66%) had adenocarcinoma, 70 (31%) squamous cell carcinoma, and 6 (2.6%) were other tumor types. Five-year survival was 43% with hospital mortality of 3.5%. Locoregional recurrence occurred in 14%. The total number of affected nodes significantly reduced survival (four or more metastatic nodes). Further analysis of the ratio of nodes affected to the total number resected showed a significant decrease in survival as the percentage of positive nodes increased (p < 0.001). Patients undergoing surgery for esophageal cancer should be staged according to a minimum total number of metastatic lymph nodes and ratios because this more accurately predicts survival than current staging systems.

Pseudomorphic InGaAs Materials

DTIC Science & Technology

1990-07-31

tive mass Schrodinger equation can be cast using a finite element technique (Galerkin residual method) into a symmetric tridiagonal matrix formulation...lnr’Gal-.’As composition. All of the structures were fabricated by molecular beam epitaxy (MBE). The effects of different growth conditions were evaluated... different growth conditions were evaluated with a combination of characterization techniques. Key results to emerge from this work relate to the

Information Processing Approaches to Cognitive Development

DTIC Science & Technology

1988-07-01

Craik . F.I.M., & Lockhart , R.S. (1972). Levels of processing : A framework for memory research. Journal of Verbal Learning and Verbal Behavior, 11...task at both levels of performance, then one would, in both cases, postulate systems that had the ability to process symbols at the microscopic level ...821760s and early 70s. (cf. Atkinson & Shiffrin. 1968: Craik & Lockhart . 1972: Norman, Rumelhart, & LNR, 1975). This architecture is comprised of several

The Ratio Between Metastatic and Examined Lymph Nodes (N Ratio) Is an Independent Prognostic Factor in Gastric Cancer Regardless of the Type of Lymphadenectomy

PubMed Central

Marchet, Alberto; Mocellin, Simone; Ambrosi, Alessandro; Morgagni, Paolo; Garcea, Domenico; Marrelli, Daniele; Roviello, Franco; de Manzoni, Giovanni; Minicozzi, Annamaria; Natalini, Giovanni; De Santis, Francesco; Baiocchi, Luca; Coniglio, Arianna; Nitti, Donato

2007-01-01

Purpose: To investigate whether the ratio between metastatic and examined lymph nodes (N ratio) is a better prognostic factor as compared with traditional staging systems in patients with gastric cancer regardless of the extension of lymph node dissection. Patients & Methods: We retrospectively reviewed the data of 1853 patients who underwent radical resection for gastric carcinoma at 6 Italian centers. Patients with >15 (group 1, n = 1421) and those with ≤15 (group 2, n = 432) lymph nodes examined were separately analyzed. N ratio categories (N ratio 0, 0%; N ratio 1, 1%–9%; N ratio 2, 10%–25%; N ratio 3, >25%) were determined by the best cut-off approach. Results: After a median follow-up of 45.5 months (range, 4–182 months), the 5-year overall survival of N0, N1, and N2 patients of group 1 versus group 2 was 83.4% versus 74.2% (P = 0.0026), 54.3% versus 44.3% (P = 0.018), and 32.7% versus 14.7% (P = 0.004), respectively, suggesting that a low number of excised lymph nodes can lead to the understaging of patients. N ratio identified subsets of patients with significantly different survival rates within N1 and N2 stages in both groups. At multivariate analysis, the N ratio (but not N stage) was retained as an independent prognostic factor both in group 1 and group 2 (HR for N ratio 1, N ratio 2, and N ratio 3 = 1.67, 2.96, and 6.59, and 1.56, 2.68, and 4.28, respectively). In our series, the implementation of N ratio led to the identification of subgroups of patients prognostically more homogeneous than those classified by the TNM system. Conclusion: N ratio is a simple and reproducible prognostic tool that can stratify patients with gastric cancer also in case of limited lymph node dissection. These data may represent the rational for improving the prognostic power of current UICC TNM staging system and ultimately the selection of patients who may most benefit from adjuvant treatments. PMID:17414602

Node Self-Deployment Algorithm Based on Pigeon Swarm Optimization for Underwater Wireless Sensor Networks

PubMed Central

Yu, Shanen; Xu, Yiming; Jiang, Peng; Wu, Feng; Xu, Huan

2017-01-01

At present, free-to-move node self-deployment algorithms aim at event coverage and cannot improve network coverage under the premise of considering network connectivity, network reliability and network deployment energy consumption. Thus, this study proposes pigeon-based self-deployment algorithm (PSA) for underwater wireless sensor networks to overcome the limitations of these existing algorithms. In PSA, the sink node first finds its one-hop nodes and maximizes the network coverage in its one-hop region. The one-hop nodes subsequently divide the network into layers and cluster in each layer. Each cluster head node constructs a connected path to the sink node to guarantee network connectivity. Finally, the cluster head node regards the ratio of the movement distance of the node to the change in the coverage redundancy ratio as the target function and employs pigeon swarm optimization to determine the positions of the nodes. Simulation results show that PSA improves both network connectivity and network reliability, decreases network deployment energy consumption, and increases network coverage. PMID:28338615

Studies of Typing from the LNR Typing Research Group.

DTIC Science & Technology

1982-09-01

For, illegal digraphs, there cannot be any predefined motor routine in long term memory, and the probability that such engrams exist for infrequent...the access to the motor engrams corresponding to the letters or digraphs composing a string is assumed to have occurred prior to the onset of the...that some motor engrams corresponding to sequences of letters are also found. This possibility will be discussed in more detail later. The length effects

Indocyanine Green Guided Pelvic Lymph Node Dissection: An Efficient Technique to Classify the Lymph Node Status of Patients with Prostate Cancer Who Underwent Radical Prostatectomy.

PubMed

Ramírez-Backhaus, Miguel; Mira Moreno, Alejandra; Gómez Ferrer, Alvaro; Calatrava Fons, Ana; Casanova, Juan; Solsona Narbón, Eduardo; Ortiz Rodríguez, Isabel María; Rubio Briones, José

2016-11-01

We evaluated the effectiveness of indocyanine green guided pelvic lymph node dissection for the optimal staging of prostate cancer and analyzed whether the technique could replace extended pelvic lymph node dissection. A solution of 25 mg indocyanine green in 5 ml sterile water was transperineally injected. Pelvic lymph node dissection was started with the indocyanine green stained nodes followed by extended pelvic lymph node dissection. Primary outcome measures were sensitivity, specificity, predictive value and likelihood ratio of a negative test of indocyanine green guided pelvic lymph node dissection. A total of 84 patients with a median age of 63.55 years and a median prostate specific antigen of 8.48 ng/ml were included in the study. Of these patients 60.7% had intermediate risk disease and 25% had high or very high risk disease. A median of 7 indocyanine green stained nodes per patient was detected (range 2 to 18) with a median of 22 nodes excised during extended pelvic lymph node dissection. Lymph node metastasis was identified in 25 patients, 23 of whom had disease properly classified by indocyanine green guided pelvic lymph node dissection. The most frequent location of indocyanine green stained nodes was the proximal internal iliac artery followed by the fossa of Marcille. The negative predictive value was 96.7% and the likelihood ratio of a negative test was 8%. Overall 1,856 nodes were removed and 603 were stained indocyanine green. Pathological examination revealed 82 metastatic nodes, of which 60% were indocyanine green stained. The negative predictive value was 97.4% but the likelihood ratio of a negative test was 58.5%. Indocyanine green guided pelvic lymph node dissection correctly staged 97% of cases. However, according to our data it cannot replace extended pelvic lymph node dissection. Nevertheless, its high negative predictive value could allow us to avoid extended pelvic lymph node dissection if we had an accurate intraoperative lymph fluorescent analysis. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Observing patchy reionization with future CMB polarization experiments

NASA Astrophysics Data System (ADS)

Roy, A.; Lapi, A.; Spergel, D.; Baccigalupi, C.

2018-05-01

We study the signal from patchy reionization in view of the future high accuracy polarization measurements of the Cosmic Microwave Background (CMB). We implement an extraction procedure of the patchy reionization signal analogous to CMB lensing. We evaluate the signal to noise ratio (SNR) for the future Stage IV (S4) CMB experiment. The signal has a broad peak centered on the degree angular scales, with a long tail at higher multipoles. The CMB S4 experiment can effectively constrain the properties of reionization by measuring the signal on degree scales. The signal amplitude depends on the properties of the structure determining the reionization morphology. We describe bubbles having radii distributed log-normally. The expected S/N is sensitive to the mean bubble radius: bar R=5 Mpc implies S/N ≈ 4, bar R=10 Mpc implies S/N ≈ 20. The spread of the radii distribution strongly affects the integrated SNR, that changes by a factor of 102 when σlnr goes from ln 2 to ln 3. Future CMB experiments will thus place important constraints on the physics of reionization.

Ultrasound texture analysis: Association with lymph node metastasis of papillary thyroid microcarcinoma.

PubMed

Kim, Soo-Yeon; Lee, Eunjung; Nam, Se Jin; Kim, Eun-Kyung; Moon, Hee Jung; Yoon, Jung Hyun; Han, Kyung Hwa; Kwak, Jin Young

2017-01-01

This retrospective study aimed to evaluate whether ultrasound texture analysis is useful to predict lymph node metastasis in patients with papillary thyroid microcarcinoma (PTMC). This study was approved by the Institutional Review Board, and the need to obtain informed consent was waived. Between May and July 2013, 361 patients (mean age, 43.8 ± 11.3 years; range, 16-72 years) who underwent staging ultrasound (US) and subsequent thyroidectomy for conventional PTMC ≤ 10 mm between May and July 2013 were included. Each PTMC was manually segmented and its histogram parameters (Mean, Standard deviation, Skewness, Kurtosis, and Entropy) were extracted with Matlab software. The mean values of histogram parameters and clinical and US features were compared according to lymph node metastasis using the independent t-test and Chi-square test. Multivariate logistic regression analysis was performed to identify the independent factors associated with lymph node metastasis. Tumors with lymph node metastasis (n = 117) had significantly higher entropy compared to those without lymph node metastasis (n = 244) (mean±standard deviation, 6.268±0.407 vs. 6.171±.0.405; P = .035). No additional histogram parameters showed differences in mean values according to lymph node metastasis. Entropy was not independently associated with lymph node metastasis on multivariate logistic regression analysis (Odds ratio, 0.977 [95% confidence interval (CI), 0.482-1.980]; P = .949). Younger age (Odds ratio, 0.962 [95% CI, 0.940-0.984]; P = .001) and lymph node metastasis on US (Odds ratio, 7.325 [95% CI, 3.573-15.020]; P < .001) were independently associated with lymph node metastasis. Texture analysis was not useful in predicting lymph node metastasis in patients with PTMC.

[Comparison of two quantitative methods of endobronchial ultrasound real-time elastography for evaluating intrathoracic lymph nodes].

PubMed

Mao, X W; Yang, J Y; Zheng, X X; Wang, L; Zhu, L; Li, Y; Xiong, H K; Sun, J Y

2017-06-12

Objective: To compare the clinical value of two quantitative methods in analyzing endobronchial ultrasound real-time elastography (EBUS-RTE) images for evaluating intrathoracic lymph nodes. Methods: From January 2014 to April 2014, EBUS-RTE examination was performed in patients who received EBUS-TBNA examination in Shanghai Chest Hospital. Each intrathoracic lymph node had a selected EBUS-RTE image. Stiff area ratio and mean hue value of region of interest (ROI) in each image were calculated respectively. The final diagnosis of lymph node was based on the pathologic/microbiologic results of EBUS-TBNA, pathologic/microbiologic results of other examinations and clinical following-up. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were evaluated for distinguishing malignant and benign lesions. Results: Fifty-six patients and 68 lymph nodes were enrolled in this study, of which 35 lymph nodes were malignant and 33 lymph nodes were benign. The stiff area ratio and mean hue value of benign and malignant lesions were 0.32±0.29, 0.62±0.20 and 109.99±28.13, 141.62±17.52, respectively, and statistical differences were found in both of those two methods ( t =-5.14, P <0.01; t =-5.53, P <0.01). The area under curves was 0.813, 0.814 in stiff area ratio and mean hue value, respectively. The optimal diagnostic cut-off value of stiff area ratio was 0.48, and the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 82.86%, 81.82%, 82.86%, 81.82% and 82.35%, respectively. The optimal diagnostic cut-off value of mean hue value was 126.28, and the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 85.71%, 75.76%, 78.95%, 83.33% and 80.88%, respectively. Conclusion: Both the stiff area ratio and mean hue value methods can be used for analyzing EBUS-RTE images quantitatively, having the value of differentiating benign and malignant intrathoracic lymph nodes, and the stiff area ratio is better than the mean hue value between the two methods.

Aspect Ratio of Receiver Node Geometry based Indoor WLAN Propagation Model

NASA Astrophysics Data System (ADS)

Naik, Udaykumar; Bapat, Vishram N.

2017-08-01

This paper presents validation of indoor wireless local area network (WLAN) propagation model for varying rectangular receiver node geometry. The rectangular client node configuration is a standard node arrangement in computer laboratories of academic institutes and research organizations. The model assists to install network nodes for the better signal coverage. The proposed model is backed by wide ranging real time received signal strength measurements at 2.4 GHz. The shadow fading component of signal propagation under realistic indoor environment is modelled with the dependency on varying aspect ratio of the client node geometry. The developed new model is useful in predicting indoor path loss for IEEE 802.11b/g WLAN. The new model provides better performance in comparison to well known International Telecommunication Union and free space propagation models. It is shown that the proposed model is simple and can be a useful tool for indoor WLAN node deployment planning and quick method for the best utilisation of the office space.

Dynamical jumping real-time fault-tolerant routing protocol for wireless sensor networks.

PubMed

Wu, Guowei; Lin, Chi; Xia, Feng; Yao, Lin; Zhang, He; Liu, Bing

2010-01-01

In time-critical wireless sensor network (WSN) applications, a high degree of reliability is commonly required. A dynamical jumping real-time fault-tolerant routing protocol (DMRF) is proposed in this paper. Each node utilizes the remaining transmission time of the data packets and the state of the forwarding candidate node set to dynamically choose the next hop. Once node failure, network congestion or void region occurs, the transmission mode will switch to jumping transmission mode, which can reduce the transmission time delay, guaranteeing the data packets to be sent to the destination node within the specified time limit. By using feedback mechanism, each node dynamically adjusts the jumping probabilities to increase the ratio of successful transmission. Simulation results show that DMRF can not only efficiently reduce the effects of failure nodes, congestion and void region, but also yield higher ratio of successful transmission, smaller transmission delay and reduced number of control packets.

Ratio between maximum standardized uptake value of N1 lymph nodes and tumor predicts N2 disease in patients with non-small cell lung cancer in 18F-FDG PET-CT scan.

PubMed

Honguero Martínez, A F; García Jiménez, M D; García Vicente, A; López-Torres Hidalgo, J; Colon, M J; van Gómez López, O; Soriano Castrejón, Á M; León Atance, P

2016-01-01

F-18 fluorodeoxyglucose integrated PET-CT scan is commonly used in the work-up of lung cancer to improve preoperative disease stage. The aim of the study was to analyze the ratio between SUVmax of N1 lymph nodes and primary lung cancer to establish prediction of mediastinal disease (N2) in patients operated on non-small cell lung cancer. This is a retrospective study of a prospective database. Patients operated on non-small cell lung cancer (NSCLC) with N1 disease by PET-CT scan were included. None of them had previous induction treatment, but they underwent standard surgical resection plus systematic lymphadenectomy. There were 51 patients with FDG-PET-CT scan N1 disease. 44 (86.3%) patients were male with a mean age of 64.1±10.8 years. Type of resection: pneumonectomy=4 (7.9%), lobectomy/bilobectomy=44 (86.2%), segmentectomy=3 (5.9%). adenocarcinoma=26 (51.0%), squamous=23 (45.1%), adenosquamous=2 (3.9%). Lymph nodes after surgical resection: N0=21 (41.2%), N1=12 (23.5%), N2=18 (35.3%). Mean ratio of the SUVmax of N1 lymph node to the SUVmax of the primary lung tumor (SUVmax N1/T ratio) was 0.60 (range 0.08-2.80). ROC curve analysis to obtain the optimal cut-off value of SUVmax N1/T ratio to predict N2 disease was performed. At multivariate analysis, we found that a ratio of 0.46 or greater was an independent predictor factor of N2 mediastinal lymph node metastases with a sensitivity and specificity of 77.8% and 69.7%, respectively. SUVmax N1/T ratio in NSCLC patients correlates with mediastinal lymph node metastasis (N2 disease) after surgical resection. When SUVmax N1/T ratio on integrated PET-CT scan is equal or superior to 0.46, special attention should be paid on higher probability of N2 disease. Copyright © 2015 Elsevier España, S.L.U. and SEMNIM. All rights reserved.

[Research on Application of Fourier Transform Infrared Spectrometry in the Diagnosis of Lymph Node Metastasis in Gastric Cancer].

PubMed

Bai, Yue-kui; Yu, Li-wei; Zhang, Le; Fu, Jing; Leng, Hui; Yang, Xiao-jun; Ma, Jun-qiang; Li, Xiao-juan; Li, Xiu-juan; Zhu, Qing; Zhang, Yuan-fu; Ling, Xiao-feng; Cao, Wen-lan

2015-03-01

To explore the feasibility of quick intraoperative in situ and noninvasive diagnosis of lymph node metastasis in gastric cancer by Fourier transform infrared (FTIR) spectrometry. FTIR spectra of surgically removed fresh lymph nodes were measured by FTIR via probe of attenuated total reflection (ATR). For each spectrum, 13 bands were indentified and assigned between 3 000 and 1 000 cm(-1). Peaks in the spectra were measured and relative intensity ratios were calculated and compared between the spectra of Metastatic lymph nodes (MLN) and Non-metastatic lymph nodes (NMLN). Standard statistic analysis was performed. 720 lymph nodes were measured in 38 gastric cancer patients. Results show that there were significant differences between the FTIR of 540 MLN and 180 NMLN. (1) For the band related to nucleic acid: The ratios of I1240/I1460 (p = 0.015) and I1080/I1460 (p = 0.034) increased in MLN, which shows that the relative quantity of nucleic acid was more in MLN than that in NMLN. (2) For the bands related to protein: The ratios of I1640 /I1460 (p = 0.001) and I146/I1460 (p = 0.027) increased in MLN, which shows that the relative quantity of protein was more in MLN. (3) For the bands related to lipid: The ratio of I2855/I460 and I1740/I1460 decreased in MLN FTIR spectrum, indicating the lower relative quantity of lipid in MLN. (4) For the bands related to carbohydrate: The ratio of I1160/I1460 (p = 0.023) decreased in MLN FTIR spectrum, indicating the lower relative quantity of carbohydrate in MLN. The results demonstrate that the FTIR spectroscopy technique maybe develop into a promising method for in situ and quick intraoperative differential diagnosis of lymph node metastasis in gastric cancer.

[Anatomy and histology characteristics of lymph node in nude mice].

PubMed

Sun, R; Gao, B; Guo, C B

2017-10-18

To compare the differences of anatomical and histological characteristics of lymph nodes between BALB/c nude mice and BALB/c mice. Firstly, twenty BALB/c nude mice and twenty BALB/c mice were dissected by using a surgical microscope. Secondly, the differences of T cells and B cells at the lymph node were compared by the expressions of CD 3 and CD 20 immunohistochemistry dyes. There were, on average, 23 nodes per mouse contained within the large lymph node assembly in the BALB/c nude mouse. The anatomical features of the lymph node distribution in the nude mice were mainly found in the neck with relatively higher density. There were two lymph nodes both in the submandible lymph nodes group and in the superficial cervical lymph nodes group (the constituent ratios were 95% and 90%, respectively) in the BALB/c nude mice, but there were four lymph nodes (the constituent ratios were 95% and 90%, respectively) in the BALB/c mice. There were significant difference between the BALB/c nude mice and the BALB/c mice. Mostly there were two lymph nodes of deep cervical lymph nodes both in the BALB/c nude mice and the BALB/c mice (the constituent ratios were 95% and 100%, respectively). There were no significant difference between the BALB/c nude mice and the BALB/c mice. We confirmed that the number of CD 3 -positive T lymphocytes in lymph nodes of the nude mice decreased greatly as compared with the BALB/c mice. Expressions of CD3 in T cells were 95% and 100% in the BALB/c nude mice and in the BALB/c mice, respectively. There were significant differences between the BALB/c nude mice and the BALB/c mice. Expressions of CD20 in B cells were 95% and 100% in the BALB/c nude mice and in the BALB/c mice, respectively. There was no significant difference between the BALB/c nude mice and BALB/c mice. The anatomical pictures of lymph node distribution in the nude mouse will be benefit to those who are interested. The anatomical features of the lymph node local higher density in neck of the nude mouse and lack of CD3-positive T lymphocytes would be useful for obtaining a better understanding of localized lymph node metastasis of oral transplant tumors.

Utility of Computed Tomography versus Abdominal Ultrasound Examination to Identify Iliosacral Lymphadenomegaly in Dogs with Apocrine Gland Adenocarcinoma of the Anal Sac.

PubMed

Palladino, S; Keyerleber, M A; King, R G; Burgess, K E

2016-11-01

Apocrine gland adenocarcinoma of the anal sac (AGAAS) is associated with high rates of iliosacral lymph node metastasis, which may influence treatment and prognosis. Magnetic resonance imaging (MRI) recently has been shown to be more sensitive than abdominal ultrasound examination (AUS) in affected patients. To compare the rate of detection of iliosacral lymphadenomegaly between AUS and computed tomography (CT) in dogs with AGAAS. Cohort A: A total of 30 presumed normal dogs. Cohort B: A total of 20 dogs with AGAAS that underwent AUS and CT. Using cohort A, mean normalized lymph node : aorta (LN : AO) ratios were established for medial iliac, internal iliac, and sacral lymph nodes. The CT images in cohort B then were reviewed retrospectively and considered enlarged if their LN : AO ratio measured 2 standard deviations above the mean normalized ratio for that particular node in cohort A. Classification and visibility of lymph nodes identified on AUS were compared to corresponding measurements obtained on CT. Computed tomography identified lymphadenomegaly in 13 of 20 AGAAS dogs. Of these 13 dogs, AUS correctly identified and detected all enlarged nodes in only 30.8%, and either misidentified or failed to detect additional enlarged nodes in the remaining dogs. Despite limitations in identifying enlargement in all affected lymph nodes, AUS identified at least 1 enlarged node in 100% of affected dogs. Abdominal ultrasound examination is an effective screening test for lymphadenomegaly in dogs with AGAAS, but CT should be considered in any patient in which an additional metastatic site would impact therapeutic planning. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Strain elastography of abnormal axillary nodes in breast cancer patients does not improve diagnostic accuracy compared with conventional ultrasound alone.

PubMed

Park, Young Mi; Fornage, Bruno D; Benveniste, Ana Paula; Fox, Patricia S; Bassett, Roland L; Yang, Wei Tse

2014-12-01

The purpose of this study was to determine the diagnostic value of strain elastography (SE) alone and in combination with gray-scale ultrasound in the diagnosis of benign versus metastatic disease for abnormal axillary lymph nodes in breast cancer patients. Patients with breast cancer and axillary lymph nodes suspicious for metastatic disease on conventional ultrasound who underwent SE of the suspicious node before ultrasound-guided fine-needle aspiration biopsy (FNAB) were included in this study. On conventional ultrasound, the long- and short-axis diameters, long-axis-to-short-axis ratio, cortical echogenicity, thickness, and evenness were documented. The nodal vascularity was assessed on power Doppler imaging. Elastograms were evaluated for the percentage of black (hard) areas in the lymph node, and the SE-ultrasound size ratio was calculated. Two readers assessed the images independently and then in consensus in cases of disagreement. ROC AUCs were calculated for conventional ultrasound, SE, and both methods combined. Interreader reliability was assessed using kappa statistics. A total of 101 patients with 104 nodes were examined; 35 nodes were benign, and 69 had metastases. SE alone showed a significantly lower AUC (62%) than did conventional ultrasound (92%) (p<0.001). There was no difference between the AUC of conventional ultrasound and the AUC of the combination of conventional ultrasound and SE (93%) (p=0.16). Interreader reliability was moderate for all variables (κ≥0.60) except the SE-ultrasound size ratio (κ=0.35). Added SE does not improve the diagnostic ability of conventional ultrasound when evaluating abnormal axillary lymph nodes.

An improved PRoPHET routing protocol in delay tolerant network.

PubMed

Han, Seung Deok; Chung, Yun Won

2015-01-01

In delay tolerant network (DTN), an end-to-end path is not guaranteed and packets are delivered from a source node to a destination node via store-carry-forward based routing. In DTN, a source node or an intermediate node stores packets in buffer and carries them while it moves around. These packets are forwarded to other nodes based on predefined criteria and finally are delivered to a destination node via multiple hops. In this paper, we improve the dissemination speed of PRoPHET (probability routing protocol using history of encounters and transitivity) protocol by employing epidemic protocol for disseminating message m, if forwarding counter and hop counter values are smaller than or equal to the threshold values. The performance of the proposed protocol was analyzed from the aspect of delivery probability, average delay, and overhead ratio. Numerical results show that the proposed protocol can improve the delivery probability, average delay, and overhead ratio of PRoPHET protocol by appropriately selecting the threshold forwarding counter and threshold hop counter values.

Hop Optimization and Relay Node Selection in Multi-hop Wireless Ad-Hoc Networks

NASA Astrophysics Data System (ADS)

Li, Xiaohua(Edward)

In this paper we propose an efficient approach to determine the optimal hops for multi-hop ad hoc wireless networks. Based on the assumption that nodes use successive interference cancellation (SIC) and maximal ratio combining (MRC) to deal with mutual interference and to utilize all the received signal energy, we show that the signal-to-interference-plus-noise ratio (SINR) of a node is determined only by the nodes before it, not the nodes after it, along a packet forwarding path. Based on this observation, we propose an iterative procedure to select the relay nodes and to calculate the path SINR as well as capacity of an arbitrary multi-hop packet forwarding path. The complexity of the algorithm is extremely low, and scaling well with network size. The algorithm is applicable in arbitrarily large networks. Its performance is demonstrated as desirable by simulations. The algorithm can be helpful in analyzing the performance of multi-hop wireless networks.

Vascularity as assessed by Doppler intraoral ultrasound around the invasion front of tongue cancer is a predictor of pathological grade of malignancy and cervical lymph node metastasis.

PubMed

Yamamoto, Chika; Yuasa, Kenji; Okamura, Kazuhiko; Shiraishi, Tomoko; Miwa, Kunihiro

2016-01-01

To quantitatively evaluate the relationship of vascularity of tongue cancer as demonstrated on intraoral ultrasonography images and tumour thickness with pathological grade of malignancy and the presence of cervical lymph node metastases. 18 patients with tongue cancer were enrolled in this retrospective study. Using Doppler ultrasonography images of the invasion front of the cancers along the length of their tumour boundaries, three vascular indexes were analysed quantitatively, namely ratio of blood flow signal area within the cancer to whole tumour area (BAR), blood flow signal number ratio (BNR) and blood flow signal width ratio (BWR). The associations between these three indexes and occurrence of cervical lymph node metastasis and pathological grade of malignancy [Yamamoto-Kohama (YK) classification] were assessed. Furthermore, the relationship between tumour thickness and occurrence of cervical lymph node metastasis was evaluated on B-mode intraoral ultrasonography images. There was no significant association between BAR and tumour thickness or occurrence of cervical lymph node metastasis. The BNRs and BWRs of patients with cervical lymph node metastasis were significantly higher than those of patients without nodal involvement. The BWRs of patients with high-grade malignancy (YK-4C) were significantly higher than those of patients with low-grade malignancy (YK-2 or 3). BNR and BWR on the invasion front of the tongue cancer are predictors of pathological grade of malignancy and cervical lymph node metastasis.

Lymph node ratio predicts disease-specific survival in melanoma patients.

PubMed

Xing, Yan; Badgwell, Brian D; Ross, Merrick I; Gershenwald, Jeffrey E; Lee, Jeffrey E; Mansfield, Paul F; Lucci, Anthony; Cormier, Janice N

2009-06-01

The objectives of this analysis were to compare various measures associated with lymph node (LN) dissection and to identify threshold values associated with disease-specific survival (DSS) outcomes in patients with melanoma. Patients with lymph node-positive melanoma who underwent therapeutic LN dissection of the neck, axilla, and inguinal region were identified from the SEER database (1988-2005). We performed Cox multivariate analyses to determine the impact of the total number of LNs removed, number of negative LNs removed, and LN ratio on DSS. Multivariate cut-point analyses were conducted for each anatomic region to identify the threshold values associated with the largest improvement in DSS. The LN ratio was significantly associated with DSS for all LN regions. The LN ratio thresholds resulting in the greatest difference in 5-year DSS were .07, .13, and .18 for neck, axillary, and inguinal regions, respectively, corresponding to 15, 8, and 6 LNs removed per positive lymph node. After adjustment for other clinicopathologic factors, the hazard ratios (HRs) were .53 (95% confidence interval [CI], .40 to .71) in the neck, .52 (95% CI, .42 to .65) in the axillary, and .47 (95% CI, .36 to .61) in the inguinal regions for patients who met the LN ratio threshold. Among the prognostic factors examined, LN ratio was the best indicator of the extent of LN dissection, regardless of anatomic nodal region. These data provide evidence-based guidelines for defining adequate LN dissections in melanoma patients. (c) 2009 American Cancer Society.

Corrosion Control of Pilings in Seawater: Buzzards Bay.

DTIC Science & Technology

1981-01-01

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Surgical excision of anal sac apocrine gland adenocarcinomas with and without adjunctive chemotherapy in dogs: 42 cases (2005-2011).

PubMed

Potanas, Christopher P; Padgett, Sheldon; Gamblin, Rance M

2015-04-15

Objective-To identify variables associated with prognosis in dogs undergoing surgical excision of anal sac apocrine gland adenocarcinomas (ASACs) with and without adjunctive chemotherapy. Design-Retrospective case series. Animals-42 dogs with ASACs. Procedures-Information on signalment, clinical signs, diagnostic procedures, surgical procedures, adjunctive therapies, survival time, and disease-free interval was obtained from the medical records. Results-Survival time was significantly associated with the presence of sublumbar lymphadenopathy and sublumbar lymph node extirpation, with median survival time significantly shorter for dogs with sublumbar lymphadenopathy (hazard ratio, 2.31) than for those without and for dogs that underwent lymph node extirpation (hazard ratio, 2.31) than for those that did not. Disease-free interval was significantly associated with the presence of sublumbar lymphadenopathy, lymph node extirpation, and administration of platinum-containing chemotherapeutic agents, with median disease-free interval significantly shorter for dogs with sublumbar lymphadenopathy (hazard ratio, 2.47) than for those without, for dogs that underwent lymph node extirpation (hazard ratio, 2.47) than for those that did not, and for dogs that received platinum-containing chemotherapeutic agents (hazard ratio, 2.69) than for those that did not. Survival time and disease-free interval did not differ among groups when dogs were grouped on the basis of histopathologic margins (complete vs marginal vs incomplete excision). Conclusions and Clinical Relevance-Results suggested that in dogs with ASAC undergoing surgical excision, the presence of sublumbar lymphadenopathy and lymph node extirpation were both negative prognostic factors. However, completeness of surgical excision was not associated with survival time or disease-free interval.

Diagnostic implications of a small-voxel reconstruction for loco-regional lymph node characterization in breast cancer patients using FDG-PET/CT.

PubMed

Koopman, Daniëlle; van Dalen, Jorn A; Arkies, Hester; Oostdijk, Ad H J; Francken, Anne Brecht; Bart, Jos; Slump, Cornelis H; Knollema, Siert; Jager, Pieter L

2018-01-16

We evaluated the diagnostic implications of a small-voxel reconstruction for lymph node characterization in breast cancer patients, using state-of-the-art FDG-PET/CT. We included 69 FDG-PET/CT scans from breast cancer patients. PET data were reconstructed using standard 4 × 4 × 4 mm 3 and small 2 × 2 × 2 mm 3 voxels. Two hundred thirty loco-regional lymph nodes were included, of which 209 nodes were visualised on PET/CT. All nodes were visually scored as benign or malignant, and SUV max and TB ratio (=SUV max /SUV background ) were measured. Final diagnosis was based on histological or imaging information. We determined the accuracy, sensitivity and specificity for both reconstruction methods and calculated optimal cut-off values to distinguish benign from malignant nodes. Sixty-one benign and 169 malignant lymph nodes were included. Visual evaluation accuracy was 73% (sensitivity 67%, specificity 89%) on standard-voxel images and 77% (sensitivity 78%, specificity 74%) on small-voxel images (p = 0.13). Across malignant nodes visualised on PET/CT, the small-voxel score was more often correct compared with the standard-voxel score (89 vs. 76%, p <  0.001). In benign nodes, the standard-voxel score was more often correct (89 vs. 74%, p = 0.04). Quantitative data were based on the 61 benign and 148 malignant lymph nodes visualised on PET/CT. SUVs and TB ratio were on average 3.0 and 1.6 times higher in malignant nodes compared to those in benign nodes (p <  0.001), on standard- and small-voxel PET images respectively. Small-voxel PET showed average increases in SUV max and TB ratio of typically 40% over standard-voxel PET. The optimal SUV max cut-off using standard-voxels was 1.8 (sensitivity 81%, specificity 95%, accuracy 85%) while for small-voxels, the optimal SUV max cut-off was 2.6 (sensitivity 78%, specificity 98%, accuracy 84%). Differences in accuracy were non-significant. Small-voxel PET/CT improves the sensitivity of visual lymph node characterization and provides a higher detection rate of malignant lymph nodes. However, small-voxel PET/CT also introduced more false-positive results in benign nodes. Across all nodes, differences in accuracy were non-significant. Quantitatively, small-voxel images require higher cut-off values. Readers have to adapt their reference standards.

Suppressed epidemics in multirelational networks

NASA Astrophysics Data System (ADS)

Xu, Elvis H. W.; Wang, Wei; Xu, C.; Tang, Ming; Do, Younghae; Hui, P. M.

2015-08-01

A two-state epidemic model in networks with links mimicking two kinds of relationships between connected nodes is introduced. Links of weights w1 and w0 occur with probabilities p and 1 -p , respectively. The fraction of infected nodes ρ (p ) shows a nonmonotonic behavior, with ρ drops with p for small p and increases for large p . For small to moderate w1/w0 ratios, ρ (p ) exhibits a minimum that signifies an optimal suppression. For large w1/w0 ratios, the suppression leads to an absorbing phase consisting only of healthy nodes within a range pL≤p ≤pR , and an active phase with mixed infected and healthy nodes for p pR . A mean field theory that ignores spatial correlation is shown to give qualitative agreement and capture all the key features. A physical picture that emphasizes the intricate interplay between infections via w0 links and within clusters formed by nodes carrying the w1 links is presented. The absorbing state at large w1/w0 ratios results when the clusters are big enough to disrupt the spread via w0 links and yet small enough to avoid an epidemic within the clusters. A theory that uses the possible local environments of a node as variables is formulated. The theory gives results in good agreement with simulation results, thereby showing the necessity of including longer spatial correlations.

Adjustable Trajectory Design Based on Node Density for Mobile Sink in WSNs

PubMed Central

Yang, Guisong; Liu, Shuai; He, Xingyu; Xiong, Naixue; Wu, Chunxue

2016-01-01

The design of movement trajectories for mobile sink plays an important role in data gathering for Wireless Sensor Networks (WSNs), as it affects the network coverage, and packet delivery ratio, as well as the network lifetime. In some scenarios, the whole network can be divided into subareas where the nodes are randomly deployed. The node densities of these subareas are quite different, which may result in a decreased packet delivery ratio and network lifetime if the movement trajectory of the mobile sink cannot adapt to these differences. To address these problems, we propose an adjustable trajectory design method based on node density for mobile sink in WSNs. The movement trajectory of the mobile sink in each subarea follows the Hilbert space-filling curve. Firstly, the trajectory is constructed based on network size. Secondly, the adjustable trajectory is established based on node density in specific subareas. Finally, the trajectories in each subarea are combined to acquire the whole network’s movement trajectory for the mobile sink. In addition, an adaptable power control scheme is designed to adjust nodes’ transmitting range dynamically according to the movement trajectory of the mobile sink in each subarea. The simulation results demonstrate that the proposed trajectories can adapt to network changes flexibly, thus outperform both in packet delivery ratio and in energy consumption the trajectories designed only based on the network size and the whole network node density. PMID:27941662

Lymph node retrieval during esophagectomy with and without neoadjuvant chemoradiotherapy: prognostic and therapeutic impact on survival.

PubMed

Koen Talsma, A; Shapiro, Joel; Looman, Caspar W N; van Hagen, Pieter; Steyerberg, Ewout W; van der Gaast, Ate; van Berge Henegouwen, Mark I; Wijnhoven, Bas P L; van Lanschot, J Jan B; Hulshof, Maarten C C M; van Laarhoven, Hanneke W M; Nieuwenhuijzen, Grard A P; Hospers, Geke A P; Bonenkamp, Johannes J; Cuesta, Miguel A; Blaisse, Reinoud J B; Busch, Olivier R C; ten Kate, Fiebo J W; Creemers, Geert-Jan; Punt, Cornelis J A; Plukker, John T M; Verheul, Henk M W; van Dekken, Herman; van der Sangen, Maurice J C; Rozema, Tom; Biermann, Katharina; Beukema, Jannet C; Piet, Anna H M; van Rij, Caroline M; Reinders, Janny G; Tilanus, Hugo W

2014-11-01

We aimed to examine the association between total number of resected nodes and survival in patients after esophagectomy with and without nCRT. Most studies concerning the potentially positive effect of extended lymphadenectomy on survival have been performed in patients who underwent surgery alone. As nCRT is known to frequently "sterilize" regional nodes, it is unclear whether extended lymphadenectomy after nCRT is still useful. Patients from the randomized CROSS-trial who completed the entire protocol (ie, surgery alone or chemoradiotherapy + surgery) were included. With Cox regression models, we compared the impact of number of resected nodes as well as resected positive nodes on survival in both groups. One hundred sixty-one patients underwent surgery alone, and 159 patients received multimodality treatment. The median (interquartile range) number of resected nodes was 18 (12-27) and 14 (9-21), with 2 (1-6) and 0 (0-1) resected positive nodes, respectively. Persistent lymph node positivity after nCRT had a greater negative prognostic impact on survival as compared with lymph node positivity after surgery alone. The total number of resected nodes was significantly associated with survival for patients in the surgery-alone arm (hazard ratio per 10 additionally resected nodes, 0.76; P=0.007), but not in the multimodality arm (hazard ratio 1.00; P=0.98). The number of resected nodes had a prognostic impact on survival in patients after surgery alone, but its therapeutic value is still controversial. After nCRT, the number of resected nodes was not associated with survival. These data question the indication for maximization of lymphadenectomy after nCRT.

Cooperative wireless network control based health and activity monitoring system.

PubMed

Prakash, R; Ganesh, A Balaji; Girish, Siva V

2016-10-01

A real-time cooperative communication based wireless network is presented for monitoring health and activity of an end-user in their environment. The cooperative communication offers better energy consumption and also an opportunity to aware the current location of a user non-intrusively. The link between mobile sensor node and relay node is dynamically established by using Received Signal Strength Indicator (RSSI) and Link Quality Indicator (LQI) based on adaptive relay selection scheme. The study proposes a Linear Acceleration based Transmission Power Decision Control (LA-TPDC) algorithm to further enhance the energy efficiency of cooperative communication. Further, the occurrences of false alarms are carefully prevented by introducing three stages of sequential warning system. The real-time experiments are carried-out by using the nodes, namely mobile sensor node, relay nodes and a destination node which are indigenously developed by using a CC430 microcontroller integrated with an in-built transceiver at 868 MHz. The wireless node performance characteristics, such as energy consumption, Signal-Noise ratio (SNR), Bit Error Rate (BER), Packet Delivery Ratio (PDR) and transmission offset are evaluated for all the participated nodes. The experimental results observed that the proposed linear acceleration based transmission power decision control algorithm almost doubles the battery life time than energy efficient conventional cooperative communication.

Pattern of node metastases in patients treated with radical cystectomy and extended or superextended pelvic lymph node dissection due to bladder cancer.

PubMed

Moschini, Marco; Arbelaez, Emilio; Cornelius, Julian; Mattei, Agostino; Shariat, Shahrokh F; Dell Oglio, Paolo; Zaffuto, Emanuele; Salonia, Andrea; Montorsi, Francesco; Briganti, Alberto; Colombo, Renzo; Gallina, Andrea

2018-06-01

Pelvic lymph node dissection (PLND) has a diagnostic and therapeutic role during radical cystectomy in bladder cancer patients. However, at the time, no prospective data supports the value of extended PLND in improving survival expectances. We sought to describe incidence and location of node metastases in patients treated with extended and superextended PLND. We evaluated 653 contemporary patients with clinically nonmetastatic high risk nonmuscle invasive or muscle-invasive bladder cancer treated with radical cystectomy and extended or superextended PLND without neoadjuvant chemotherapy at a single tertiary referral center between 1990 and 2013. Limited PLND is defined as the removal of obturator and internal iliac nodes. Standard included also the external iliac nodes. Extended includes also common and presacral nodes. Finally, superextended PLND includes all the nodes removed along the inferior mesenteric artery. We evaluated incidence of pathologically node metastases. Logistic regression analyses evaluate preoperative and pathologic characteristics to the risk of harboring node metastases in the extended and superextended template. Overall, 191 (29.3%) patients were found with pathologically node confirmed metastases. Of these, 56 (29.3%) patients were found with a single node metastasis, while 135 (70.7%) had multiple node metastases. The vast majority of patients were found with node metastases standard template (n = 172, 26.3%), on the other hand 30 (4.6%) and 21 (3.2%) patients had node metastases in extended and superextended templates, respectively. However, of these only 2 patients were found without concomitant lymph node metastases in the limited or standard templates. On multivariable analyses, cN+ status (odds ratio = 4.40, P<0.001) and cT3-4 vs. cT1-2 (odds ratio = 2.25, P<0.001) were associated with an increased risk of harboring node metastases in the extended or superextended template. We found that the majority of patients harbored node disease in the limited or standard node dissection pattern. On the other hand, only a minority of patient were found with a disease in extended or superextended template without harboring a concomitant node disease in the limited pattern. Copyright © 2018 Elsevier Inc. All rights reserved.

The accumulation of regulatory T cells in the hepatic hilar lymph nodes in biliary atresia.

PubMed

Sakamoto, Naoya; Muraji, Toshihiro; Ohtani, Haruo; Masumoto, Kouji

2017-10-01

A proposed etiopathogenesis of biliary atresia (BA) involves T-cell-mediated inflammatory bile duct damage and progressive hepatic fibrosis. Pediatric surgeons often observe swelling of the hepatic hilar lymph nodes during the Kasai procedure. Given the importance of regulatory mechanisms in immune responses, the present study was designed to analyze the quantitative changes of regulatory T cells (T reg cells) in the hepatic hilar lymph nodes (hepatic hilar LNs) and peripheral blood (PB) in BA. The hepatic hilar LNs and PB obtained during the Kasai procedure were analyzed by flow cytometry. The ratios of total and active Tregs to the total CD4 + cells in the PB and the hepatic hilar LNs were compared. In patients with BA, the ratios of both the total and active T reg cells in the hepatic hilar LNs were higher than those in the PB (total T reg cells: PB vs. LN; P < 0.001; active T reg cells: PB vs. LN; P = 0.001). In BA patients, the increase in the ratio of active T reg cells to the CD4 + cells in the LNs in comparison to the PB was greater than that in control patients. The ratio observed in the BA patients was almost double the ratio observed in the control patients. The median LN/PB ratio in the BA patients was 3.1, while that in controls was 1.6 (P = 0.03). The present study showed that the ratios of both total T reg cells and active T reg cells were higher in the hepatic hilar lymph nodes of BA patients. This finding could shed light on the pathogenesis of BA.

Statistical evaluation of the Local Lymph Node Assay.

PubMed

Hothorn, Ludwig A; Vohr, Hans-Werner

2010-04-01

In the Local Lymph Node Assay measured endpoints for each animal, such as cell proliferation, cell counts and/or lymph node weight should be evaluated separately. The primary criterion for a positive response is when the estimated stimulation index is larger than a specified relative threshold that is endpoint- and strain-specific. When the lower confidence limit for ratio-to-control comparisons is larger than a relevance threshold, a biologically relevant increase can be concluded according to the proof of hazard. Alternatively, when the upper confidence limit for ratio-to-control comparisons is smaller than a tolerable margin, harmlessness can be concluded according to a proof of safety. Copyright 2009 Elsevier Inc. All rights reserved.

AURP: An AUV-Aided Underwater Routing Protocol for Underwater Acoustic Sensor Networks

PubMed Central

Yoon, Seokhoon; Azad, Abul K.; Oh, Hoon; Kim, Sunghwan

2012-01-01

Deploying a multi-hop underwater acoustic sensor network (UASN) in a large area brings about new challenges in reliable data transmissions and survivability of network due to the limited underwater communication range/bandwidth and the limited energy of underwater sensor nodes. In order to address those challenges and achieve the objectives of maximization of data delivery ratio and minimization of energy consumption of underwater sensor nodes, this paper proposes a new underwater routing scheme, namely AURP (AUV-aided underwater routing protocol), which uses not only heterogeneous acoustic communication channels but also controlled mobility of multiple autonomous underwater vehicles (AUVs). In AURP, the total data transmissions are minimized by using AUVs as relay nodes, which collect sensed data from gateway nodes and then forward to the sink. Moreover, controlled mobility of AUVs makes it possible to apply a short-range high data rate underwater channel for transmissions of a large amount of data. To the best to our knowledge, this work is the first attempt to employ multiple AUVs as relay nodes in a multi-hop UASN to improve the network performance in terms of data delivery ratio and energy consumption. Simulations, which are incorporated with a realistic underwater acoustic communication channel model, are carried out to evaluate the performance of the proposed scheme, and the results indicate that a high delivery ratio and low energy consumption can be achieved. PMID:22438740

AURP: an AUV-aided underwater routing protocol for underwater acoustic sensor networks.

PubMed

Yoon, Seokhoon; Azad, Abul K; Oh, Hoon; Kim, Sunghwan

2012-01-01

Deploying a multi-hop underwater acoustic sensor network (UASN) in a large area brings about new challenges in reliable data transmissions and survivability of network due to the limited underwater communication range/bandwidth and the limited energy of underwater sensor nodes. In order to address those challenges and achieve the objectives of maximization of data delivery ratio and minimization of energy consumption of underwater sensor nodes, this paper proposes a new underwater routing scheme, namely AURP (AUV-aided underwater routing protocol), which uses not only heterogeneous acoustic communication channels but also controlled mobility of multiple autonomous underwater vehicles (AUVs). In AURP, the total data transmissions are minimized by using AUVs as relay nodes, which collect sensed data from gateway nodes and then forward to the sink. Moreover, controlled mobility of AUVs makes it possible to apply a short-range high data rate underwater channel for transmissions of a large amount of data. To the best to our knowledge, this work is the first attempt to employ multiple AUVs as relay nodes in a multi-hop UASN to improve the network performance in terms of data delivery ratio and energy consumption. Simulations, which are incorporated with a realistic underwater acoustic communication channel model, are carried out to evaluate the performance of the proposed scheme, and the results indicate that a high delivery ratio and low energy consumption can be achieved.

Prognostic Value of Lymph Node Yield and Density in Head and Neck Malignancies.

PubMed

Cheraghlou, Shayan; Otremba, Michael; Kuo Yu, Phoebe; Agogo, George O; Hersey, Denise; Judson, Benjamin L

2018-06-01

Objective Studies have suggested that the lymph node yield and lymph node density from selective or elective neck dissections are predictive of patient outcomes and may be used for patient counseling, treatment planning, or quality measurement. Our objective was to systematically review the literature and conduct a meta-analysis of studies that investigated the prognostic significance of lymph node yield and/or lymph node density after neck dissection for patients with head and neck cancer. Data Sources The Ovid/Medline, Ovid/Embase, and NLM PubMed databases were systematically searched on January 23, 2017, for articles published between January 1, 1946, and January 23, 2017. Review Methods We reviewed English-language original research that included survival analysis of patients undergoing neck dissection for a head and neck malignancy stratified by lymph node yield and/or lymph node density. Study data were extracted by 2 independent researchers (S.C. and M.O.). We utilized the DerSimonian and Laird random effects model to account for heterogeneity of studies. Results Our search yielded 350 nonduplicate articles, with 23 studies included in the final synthesis. Pooled results demonstrated that increased lymph node yield was associated with a significant improvement in survival (hazard ratio, 0.833; 95% CI, 0.790-0.879). Additionally, we found that increased lymph node density was associated with poorer survival (hazard ratio, 1.916; 95% CI, 1.637-2.241). Conclusions Increased nodal yield portends improved outcomes and may be a valuable quality indicator for neck dissections, while increased lymph node density is associated with diminished survival and may be used for postsurgical counseling and planning for adjuvant therapy.

A Mobile Anchor Assisted Localization Algorithm Based on Regular Hexagon in Wireless Sensor Networks

PubMed Central

Rodrigues, Joel J. P. C.

2014-01-01

Localization is one of the key technologies in wireless sensor networks (WSNs), since it provides fundamental support for many location-aware protocols and applications. Constraints of cost and power consumption make it infeasible to equip each sensor node in the network with a global position system (GPS) unit, especially for large-scale WSNs. A promising method to localize unknown nodes is to use several mobile anchors which are equipped with GPS units moving among unknown nodes and periodically broadcasting their current locations to help nearby unknown nodes with localization. This paper proposes a mobile anchor assisted localization algorithm based on regular hexagon (MAALRH) in two-dimensional WSNs, which can cover the whole monitoring area with a boundary compensation method. Unknown nodes calculate their positions by using trilateration. We compare the MAALRH with HILBERT, CIRCLES, and S-CURVES algorithms in terms of localization ratio, localization accuracy, and path length. Simulations show that the MAALRH can achieve high localization ratio and localization accuracy when the communication range is not smaller than the trajectory resolution. PMID:25133212

Occult Pelvic Lymph Node Involvement in Bladder Cancer: Implications for Definitive Radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goldsmith, Benjamin; Baumann, Brian C.; He, Jiwei

2014-03-01

Purpose: To inform radiation treatment planning for clinically staged, node-negative bladder cancer patients by identifying clinical factors associated with the presence and location of occult pathologic pelvic lymph nodes. Methods and Materials: The records of patients with clinically staged T1-T4N0 urothelial carcinoma of the bladder undergoing radical cystectomy and pelvic lymphadenectomy at a single institution were reviewed. Logistic regression was used to evaluate associations between preoperative clinical variables and occult pathologic pelvic or common iliac lymph nodes. Percentages of patient with involved lymph node regions entirely encompassed within whole bladder (perivesicular nodal region), small pelvic (perivesicular, obturator, internal iliac, andmore » external iliac nodal regions), and extended pelvic clinical target volume (CTV) (small pelvic CTV plus common iliac regions) were calculated. Results: Among 315 eligible patients, 81 (26%) were found to have involved pelvic lymph nodes at the time of surgery, with 38 (12%) having involved common iliac lymph nodes. Risk of occult pathologically involved lymph nodes did not vary with clinical T stage. On multivariate analysis, the presence of lymphovascular invasion (LVI) on preoperative biopsy was significantly associated with occult pelvic nodal involvement (odds ratio 3.740, 95% confidence interval 1.865-7.499, P<.001) and marginally associated with occult common iliac nodal involvement (odds ratio 2.307, 95% confidence interval 0.978-5.441, P=.056). The percentages of patients with involved lymph node regions entirely encompassed by whole bladder, small pelvic, and extended pelvic CTVs varied with clinical risk factors, ranging from 85.4%, 95.1%, and 100% in non-muscle-invasive patients to 44.7%, 71.1%, and 94.8% in patients with muscle-invasive disease and biopsy LVI. Conclusions: Occult pelvic lymph node rates are substantial for all clinical subgroups, especially patients with LVI on biopsy. Extended coverage of pelvic lymph nodes up to the level of the common iliac nodes may be warranted in subsets of patients.« less

Clinical and pathological factors influencing survival in a large cohort of triple-negative breast cancer patients.

PubMed

Urru, Silvana Anna Maria; Gallus, Silvano; Bosetti, Cristina; Moi, Tiziana; Medda, Ricardo; Sollai, Elisabetta; Murgia, Alma; Sanges, Francesca; Pira, Giovanna; Manca, Alessandra; Palmas, Dolores; Floris, Matteo; Asunis, Anna Maria; Atzori, Francesco; Carru, Ciriaco; D'Incalci, Maurizio; Ghiani, Massimo; Marras, Vincenzo; Onnis, Daniela; Santona, Maria Cristina; Sarobba, Giuseppina; Valle, Enrichetta; Canu, Luisa; Cossu, Sergio; Bulfone, Alessandro; Rocca, Paolo Cossu; De Miglio, Maria Rosaria; Orrù, Sandra

2018-01-08

To provide further information on the clinical and pathological prognostic factors in triple-negative breast cancer (TNBC), for which limited and inconsistent data are available. Pathological characteristics and clinical records of 841 TNBCs diagnosed between 1994 and 2015 in four major oncologic centers from Sardinia, Italy, were reviewed. Multivariate hazard ratios (HRs) for mortality and recurrence according to various clinicopathological factors were estimated using Cox proportional hazards models. After a mean follow-up of 4.3 years, 275 (33.3%) TNBC patients had a progression of the disease and 170 (20.2%) died. After allowance for study center, age at diagnosis, and various clinicopathological factors, all components of the TNM staging system were identified as significant independent prognostic factors for TNBC mortality. The HRs were 3.13, 9.65, and 29.0, for stage II, III and IV, respectively, vs stage I. Necrosis and Ki-67 > 16% were also associated with increased mortality (HR: 1.61 and 1.99, respectively). Patients with tumor histotypes other than ductal invasive/lobular carcinomas had a more favorable prognosis (HR: 0.40 vs ductal invasive carcinoma). No significant associations with mortality were found for histologic grade, tumor infiltrating lymphocytes, and lymphovascular invasion. Among lymph node positive TNBCs, lymph node ratio appeared to be a stronger predictor of mortality than pathological lymph nodes stage (HR: 0.80 for pN3 vs pN1, and 3.05 for >0.65 vs <0.21 lymph node ratio), respectively. Consistent results were observed for cancer recurrence, except for Ki-67 and necrosis that were not found to be significant predictors for recurrence. This uniquely large study of TNBC patients provides further evidence that, besides tumor stage at diagnosis, lymph node ratio among lymph node positive tumors is an additional relevant predictor of survival and tumor recurrence, while Ki-67 seems to be predictive of mortality, but not of recurrence.

Using Link Disconnection Entropy Disorder to Detect Fast Moving Nodes in MANETs.

PubMed

Alvarez, Carlos F; Palafox, Luis E; Aguilar, Leocundo; Sanchez, Mauricio A; Martinez, Luis G

2016-01-01

Mobile ad-hoc networks (MANETs) are dynamic by nature; this dynamism comes from node mobility, traffic congestion, and other transmission conditions. Metrics to evaluate the effects of those conditions shine a light on node's behavior in an ad-hoc network, helping to identify the node or nodes with better conditions of connection. In this paper, we propose a relative index to evaluate a single node reliability, based on the link disconnection entropy disorder using neighboring nodes as reference. Link disconnection entropy disorder is best used to identify fast moving nodes or nodes with unstable communications, this without the need of specialized sensors such as GPS. Several scenarios were studied to verify the index, measuring the effects of Speed and traffic density on the link disconnection entropy disorder. Packet delivery ratio is associated to the metric detecting a strong relationship, enabling the use of the link disconnection entropy disorder to evaluate the stability of a node to communicate with other nodes. To expand the utilization of the link entropy disorder, we identified nodes with higher speeds in network simulations just by using the link entropy disorder.

Energy Consumption Research of Mobile Data Collection Protocol for Underwater Nodes Using an USV.

PubMed

Lv, Zhichao; Zhang, Jie; Jin, Jiucai; Li, Qi; Gao, Baoru

2018-04-16

The Unmanned Surface Vehicle (USV) integrated with an acoustic modem is a novel mobile vehicle for data collection, which has an advantage in terms of mobility, efficiency, and collection cost. In the scenario of data collection, the USV is controlled autonomously along the planning trajectory and the data of underwater nodes are dynamically collected. In order to improve the efficiency of data collection and extend the life of the underwater nodes, a mobile data collection protocol for underwater nodes using the USV was proposed. In the protocol, the stop-and-wait ARQ transmission mechanism is adopted, where the duty cycle is designed considering the ratio between the sleep mode and the detection mode, and the transmission ratio is defined by the duty cycle, wake-up signal cycles, and USV’s speed. According to protocol, the evaluation index for energy consumption is constructed based on the duty cycle and the transmission ratio. The energy consumption of the protocol is simulated and analyzed using the mobile communication experiment data of USV, taking into consideration USV’s speed, data sequence length, and duty cycle. Optimized protocol parameters are identified, which in turn denotes the proposed protocol’s feasibility and effectiveness.

Bulk Nanolaminated Nickel: Preparation, Microstructure, Mechanical Property, and Thermal Stability

NASA Astrophysics Data System (ADS)

Liu, Fan; Yuan, Hao; Goel, Sunkulp; Liu, Ying; Wang, Jing Tao

2018-02-01

A bulk nanolaminated (NL) structure with distinctive fractions of low- and high-angle grain boundaries ( f LAGBs and f HAGBs) is produced in pure nickel, through a two-step process of primary grain refinement by equal-channel angular pressing (ECAP), followed by a secondary geometrical refinement via liquid nitrogen rolling (LNR). The lamellar boundary spacings of 2N and 4N nickel are refined to 40 and 70 nm, respectively, and the yield strength of the NL structure in 2N nickel reaches 1.5 GPa. The impacts of the deformation path, material purity, grain boundary (GB) misorientation, and energy on the microstructure, refinement ability, mechanical strength, and thermal stability are investigated to understand the inherent governing mechanisms. GB migration is the main restoration mechanism limiting the refinement of an NL structure in 4N nickel, while in 2N nickel, shear banding occurs and mediates one-fifth of the total true normal rolling strain at the mesoscale, restricting further refinement. Three typical structures [ultrafine grained (UFG), NL with low f LAGBs, and NL with high f LAGBs] obtained through three different combinations of ECAP and LNR were studied by isochronal annealing for 1 hour at temperatures ranging from 433 K to 973 K (160 °C to 700 °C). Higher thermal stability in the NL structure with high f LAGBs is shown by a 50 K (50 °C) delay in the initiation temperature of recrystallization. Based on calculations and analyses of the stored energies of deformed structures from strain distribution, as characterized by kernel average misorientation (KAM), and from GB misorientations, higher thermal stability is attributed to high f LAGBs in this type of NL structure. This is confirmed by a slower change in the microstructure, as revealed by characterizing its annealing kinetics using KAM maps.

Subgroup Economic Evaluation of Radiotherapy for Breast Cancer After Mastectomy.

PubMed

Wan, Xiaomin; Peng, Liubao; Ma, Jinan; Chen, Gannong; Li, Yuanjian

2015-11-01

A recent meta-analysis by the Early Breast Cancer Trialists' Collaborative Group found significant improvements achieved by postmastectomy radiotherapy (PMRT) for patients with breast cancer with 1 to 3 positive nodes (pN1-3). It is unclear whether PMRT is cost-effective for subgroups of patients with positive nodes. To determine the cost-effectiveness of PMRT for subgroups of patients with breast cancer with positive nodes. A semi-Markov model was constructed to estimate the expected lifetime costs, life expectancy, and quality-adjusted life-years for patients receiving or not receiving radiation therapy. Clinical and health utilities data were from meta-analyses by the Early Breast Cancer Trialists' Collaborative Group or randomized clinical trials. Costs were estimated from the perspective of the Chinese society. One-way and probabilistic sensitivity analyses were performed. The incremental cost-effective ratio was estimated as $7984, $4043, $3572, and $19,021 per quality-adjusted life-year for patients with positive nodes (pN+), patients with pN1-3, patients with pN1-3 who received systemic therapy, and patients with >4 positive nodes (pN4+), respectively. According to World Health Organization recommendations, these incremental cost-effective ratios were judged as cost-effective. However, the results of one-way sensitivity analyses suggested that the results were highly sensitive to the relative effectiveness of PMRT (rate ratio). We determined that the results were highly sensitive to the rate ratio. However, the addition of PMRT for patients with pN1-3 in China has a reasonable chance to be cost-effective and may be judged as an efficient deployment of limited health resource, and the risk and uncertainty of PMRT are relatively greater for patients with pN4+. Copyright © 2015 Elsevier HS Journals, Inc. All rights reserved.

Factors affecting mortality in elderly patients who underwent surgery for gastric cancer.

PubMed

Kayılıoglu, Selami Ilgaz; Göktug, Ufuk Utku; Dinc, Tolga; Sozen, Isa; Yavuz, Zeynep; Coskun, Faruk

2018-03-05

The aim of this study was to determine factors affecting overall mortality in patients over 60 years of age who underwent surgery for gastric cancer in our clinic. Data on histopathological diagnosis (tumor size, lymph node status, and number), pathological stage, serum albumin level, tumor markers, complete blood count, and demographic information of 109 patients over 60 years of age who had surgery for gastric cancer between January 2011 and July 2016 were obtained retrospectively from the patient files. In addition, the survival status of all patients were examined and recorded. Metastatic lymph node ratio (MLR), red cell distribution width platelet ratio (RPR), neutrophil-lymphocyte ratio (NLR), plateletlymphocyte ratio (PLR), and prognostic nutritional index (PNI) were calculated. On univariate analysis of independent parameters, pathological LN number (p = 0.001), MLR (p <0.001), T3 (p = 0.001) or T4 (p = 0,006) tumor stage according to TNM system, the presence of metastasis (p = 0.063), and male gender (p = 0.066) were found to affect overall mortality (OM). On multivariable Cox regression analysis of these results, MLR (p = 0.005) and T stage (p = 0.006) was determined to be a statistically significant and independent prognostic value. In patients over 60 years of age who underwent surgery for gastric cancer, the factors affecting mortality were determined to be the presence of metastases, number of pathological lymph nodes, and male gender. Metastatic lymph node ratio and T1&T2 stage were determined to be independent prognostic factors. Elderly, Gastric cancer, Mortality, Prognostic factor.

Nonlinear Finite Element Analysis of Shells with Large Aspect Ratio

NASA Technical Reports Server (NTRS)

Chang, T. Y.; Sawamiphakdi, K.

1984-01-01

A higher order degenerated shell element with nine nodes was selected for large deformation and post-buckling analysis of thick or thin shells. Elastic-plastic material properties are also included. The post-buckling analysis algorithm is given. Using a square plate, it was demonstrated that the none-node element does not have shear locking effect even if its aspect ratio was increased to the order 10 to the 8th power. Two sample problems are given to illustrate the analysis capability of the shell element.

In Vivo{sup 1}H Magnetic Resonance Spectroscopy of Lactate in Patients With Stage IV Head and Neck Squamous Cell Carcinoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Le, Quynh-Thu; Koong, Albert; Lieskovsky, Yee Yie

2008-07-15

Purpose: To investigate in vivo{sup 1}H magnetic resonance spectroscopy imaging of lactate for assessing tumor hypoxia in head and neck cancers and to determine its utility in predicting the response and outcomes. Methods and Materials: Volume-localized lactate-edited {sup 1}H magnetic resonance spectroscopy at 1.5 T was performed in vivo on involved neck nodes and control subcutaneous tissues in 36 patients with Stage IV head and neck cancer. The signal intensities (SIs) of lactate, choline, and creatine and the choline/creatine ratio were measured. The tumor partial pressure of oxygen (pO{sub 2}) was obtained in the same lymph node before MRS. Patientsmore » were treated with either two cycles of induction chemotherapy (tirapazamine, cisplatin, 5-fluorouracil) followed by simultaneous chemoradiotherapy or the same regimen without tirapazamine. The lactate SI and the choline/creatine ratio correlated with the tumor pO{sub 2}, nodal response, and locoregional control. Results: The lactate SI was greater for the involved nodes (median, 0.25) than for the subcutaneous tissue (median, 0.04; p = 0.07). No significant correlation was found between the lactate SI and tumor pO{sub 2} (mean, 0.46 {+-} 0.10 for hypoxic nodes [pO{sub 2} {<=}10 mm Hg, n = 15] vs. 0.36 {+-} 0.07 for nonhypoxic nodes [pO{sub 2} >10 mm Hg, n = 21], p = 0.44). A significant correlation was found between the choline/creatine ratios and tumor pO{sub 2} (mean, 2.74 {+-} 0.34 for hypoxic nodes vs. 1.78 {+-} 0.31 for nonhypoxic nodes, p = 0.02). No correlation was found between the lactate SI and the complete nodal response (p = 0.52) or locoregional control rates. Conclusions: The lactate SI did not correlate with tumor pO{sub 2}, treatment response, or locoregional control. Additional research is needed to refine this technique.« less

Axisymmetric bubble pinch-off at high Reynolds numbers.

PubMed

Gordillo, J M; Sevilla, A; Rodríguez-Rodríguez, J; Martínez-Bazán, C

2005-11-04

Analytical considerations and potential-flow numerical simulations of the pinch-off of bubbles at high Reynolds numbers reveal that the bubble minimum radius, rn, decreases as tau proportional to r2n sqrt[1lnr2n], where tau is the time to break up, when the local shape of the bubble near the singularity is symmetric. However, if the gas convective terms in the momentum equation become of the order of those of the liquid, the bubble shape is no longer symmetric and the evolution of the neck changes to a rn proportional to tau1/3 power law. These findings are verified experimentally.

On the lunar node resonance of the orbital plane evolution of the Earth's satellite orbits

NASA Astrophysics Data System (ADS)

Zhu, Ting-Lei

2018-06-01

This paper aims to investigate the effects of lunar node resonance on the circular medium Earth orbits (MEO). The dynamical model is established in classical Hamiltonian systems with the application of Lie transform to remove the non-resonant terms. Resonant condition, stability and phase structures are studied. The lunar node resonance occurs when the secular changing rates of the orbital node (with respect to the equator) and the lunar node (with respect to the ecliptic) form a simple integer ratio. The resonant conditions are satisfied for both inclined and equatorial orbits. The orbital plane would have long period (with typical timescales of several centuries) fluctuation due to the resonance.

Assessing localized skin-to-fat water in arms of women with breast cancer via tissue dielectric constant measurements in pre- and post-surgery patients.

PubMed

Mayrovitz, Harvey N; Weingrad, Daniel N; Lopez, Lidice

2015-05-01

Skin-to-fat tissue dielectric constant (TDC) values at 300 MHz largely depend on tissue water and provide a rapid way to assess skin water by touching skin with a probe for approximately 10 s. This method has been used to investigate lymphedema features accompanying breast cancer (BC), but relationships between TDC and nodes removed or symptoms is unclear. Our goals were: (1) to compare TDC values in BC patients prior to surgery (group A) and in patients who had BC-related surgery (group B) to determine if TDC of group B were related to nodes removed and reported symptoms and (2) to develop tentative lymphedema-detection thresholds. Arm volumes and TDC values of at-risk and contralateral forearms and biceps were determined in 103 women awaiting surgery for BC and 104 women who had BC-related surgery 26.3 ± 17.5 months prior to evaluation. Inter-arm ratios (at-risk/contralateral) were determined and patients answered questions about lymphedema-related symptoms. Inter-arm TDC ratios for group A forearm and biceps were respectively 1.003 ± 0.096 and 1.012 ± 0.143. Group B forearm ratios were significantly greater, and among group B patients who reported at least one symptom there was a significant correlation between TDC ratios and symptom burden and nodes removed. Inter-arm TDC ratios are significantly related to symptoms and nodes removed. Ratios increase with increasing symptom score and might be used to detect pre-clinical unilateral lymphedema using TDC ratio thresholds of 1.30 for forearm and 1.45 for biceps. Threshold confirmation awaits targeted prospective studies but can serve as guideposts to provide quantitative and easily done tracking assessments during follow-up visits.

Classification between Failed Nodes and Left Nodes in Mobile Asset Tracking Systems †

PubMed Central

Kim, Kwangsoo; Jin, Jae-Yeon; Jin, Seong-il

2016-01-01

Medical asset tracking systems track a medical device with a mobile node and determine its status as either in or out, because it can leave a monitoring area. Due to a failed node, this system may decide that a mobile asset is outside the area, even though it is within the area. In this paper, an efficient classification method is proposed to separate mobile nodes disconnected from a wireless sensor network between nodes with faults and a node that actually has left the monitoring region. The proposed scheme uses two trends extracted from the neighboring nodes of a disconnected mobile node. First is the trend in a series of the neighbor counts; the second is that of the ratios of the boundary nodes included in the neighbors. Based on such trends, the proposed method separates failed nodes from mobile nodes that are disconnected from a wireless sensor network without failures. The proposed method is evaluated using both real data generated from a medical asset tracking system and also using simulations with the network simulator (ns-2). The experimental results show that the proposed method correctly differentiates between failed nodes and nodes that are no longer in the monitoring region, including the cases that the conventional methods fail to detect. PMID:26901200

Sonographic findings predictive of central lymph node metastasis in patients with papillary thyroid carcinoma: influence of associated chronic lymphocytic thyroiditis on the diagnostic performance of sonography.

PubMed

Yoo, Yeon Hwa; Kim, Jeong-Ah; Son, Eun Ju; Youk, Ji Hyun; Kwak, Jin Young; Kim, Eun-Kyung; Park, Cheong Soo

2013-12-01

To analyze sonographic findings suggesting central lymph node metastasis of papillary thyroid carcinoma and to evaluate the influence of associated chronic lymphocytic thyroiditis on the diagnostic performance of sonography for predicting central lymph node metastasis. A total of 124 patients (101 female and 23 male; mean age, 47.5 years; range, 21-74 years) underwent sonographically guided fine-needle aspiration in central lymph nodes from January 2008 to July 2011. Sonographic features of size, shape, margin, thickening of the cortex, cortical echogenicity, presence of a hilum, cystic changes, calcification, and vascularity of enlarged lymph nodes were analyzed before fine-needle aspiration and classified into 2 categories (probably benign and suspicious). Sonographic findings were correlated with the pathologic diagnosis and associated chronic lymphocytic thyroiditis. Receiver operating characteristic curve analysis was performed to assess the diagnostic performance of sonography for predicting central lymph node metastasis according to the associated thyroiditis. Fifty-one lymph nodes (39.5%) were malignant, and 73 (60.5%) were benign. On univariate analysis, size, shape, margin, cortical thickening, cortical echogenicity, cystic changes, calcification, and vascularity were significantly different between the benign and metastatic nodes (P < .05). On multivariate analysis, eccentric cortical thickening (odds ratio, 26.59; 95% confidence interval [CI], 3.26-216.66) and hyper echogenicity of the cortex (odds ratio, 18.46; 95% CI, 2.44-139.64) were significantly associated with malignant nodes (P < .05). The area under the curve values for sonography for predicting metastasis were 0.756 (95% CI, 0.618-0.894) in chronic lymphocytic thyroiditis-positive patients and 0.971 (95% CI, 0.938-1.000) in negative patients. Eccentric cortical thickening and cortical hyperechogenicity were the sonographic findings predictive of central lymph node metastasis from papillary thyroid carcinoma. The diagnostic performance of sonography for predicting metastasis was superior in chronic lymphocytic thyroiditis-negative patients than in positive patients.

Patterns of a spatial exploration under time evolution of the attractiveness: Persistent nodes, degree distribution, and spectral properties

NASA Astrophysics Data System (ADS)

da Silva, Roberto

2018-06-01

This work explores the features of a graph generated by agents that hop from one node to another node, where the nodes have evolutionary attractiveness. The jumps are governed by Boltzmann-like transition probabilities that depend both on the euclidean distance between the nodes and on the ratio (β) of the attractiveness between them. It is shown that persistent nodes, i.e., nodes that never been reached by this special random walk are possible in the stationary limit differently from the case where the attractiveness is fixed and equal to one for all nodes (β = 1). Simultaneously, one also investigates the spectral properties and statistics related to the attractiveness and degree distribution of the evolutionary network. Finally, a study of the crossover between persistent phase and no persistent phase was performed and it was also observed the existence of a special type of transition probability which leads to a power law behaviour for the time evolution of the persistence.

Using Link Disconnection Entropy Disorder to Detect Fast Moving Nodes in MANETs

PubMed Central

Palafox, Luis E.; Aguilar, Leocundo; Sanchez, Mauricio A.; Martinez, Luis G.

2016-01-01

Mobile ad-hoc networks (MANETs) are dynamic by nature; this dynamism comes from node mobility, traffic congestion, and other transmission conditions. Metrics to evaluate the effects of those conditions shine a light on node’s behavior in an ad-hoc network, helping to identify the node or nodes with better conditions of connection. In this paper, we propose a relative index to evaluate a single node reliability, based on the link disconnection entropy disorder using neighboring nodes as reference. Link disconnection entropy disorder is best used to identify fast moving nodes or nodes with unstable communications, this without the need of specialized sensors such as GPS. Several scenarios were studied to verify the index, measuring the effects of Speed and traffic density on the link disconnection entropy disorder. Packet delivery ratio is associated to the metric detecting a strong relationship, enabling the use of the link disconnection entropy disorder to evaluate the stability of a node to communicate with other nodes. To expand the utilization of the link entropy disorder, we identified nodes with higher speeds in network simulations just by using the link entropy disorder. PMID:27219671

An enhanced performance through agent-based secure approach for mobile ad hoc networks

NASA Astrophysics Data System (ADS)

Bisen, Dhananjay; Sharma, Sanjeev

2018-01-01

This paper proposes an agent-based secure enhanced performance approach (AB-SEP) for mobile ad hoc network. In this approach, agent nodes are selected through optimal node reliability as a factor. This factor is calculated on the basis of node performance features such as degree difference, normalised distance value, energy level, mobility and optimal hello interval of node. After selection of agent nodes, a procedure of malicious behaviour detection is performed using fuzzy-based secure architecture (FBSA). To evaluate the performance of the proposed approach, comparative analysis is done with conventional schemes using performance parameters such as packet delivery ratio, throughput, total packet forwarding, network overhead, end-to-end delay and percentage of malicious detection.

Dynamic resource allocation scheme for distributed heterogeneous computer systems

NASA Technical Reports Server (NTRS)

Liu, Howard T. (Inventor); Silvester, John A. (Inventor)

1991-01-01

This invention relates to a resource allocation in computer systems, and more particularly, to a method and associated apparatus for shortening response time and improving efficiency of a heterogeneous distributed networked computer system by reallocating the jobs queued up for busy nodes to idle, or less-busy nodes. In accordance with the algorithm (SIDA for short), the load-sharing is initiated by the server device in a manner such that extra overhead in not imposed on the system during heavily-loaded conditions. The algorithm employed in the present invention uses a dual-mode, server-initiated approach. Jobs are transferred from heavily burdened nodes (i.e., over a high threshold limit) to low burdened nodes at the initiation of the receiving node when: (1) a job finishes at a node which is burdened below a pre-established threshold level, or (2) a node is idle for a period of time as established by a wakeup timer at the node. The invention uses a combination of the local queue length and the local service rate ratio at each node as the workload indicator.

A Deadline-Aware Scheduling and Forwarding Scheme in Wireless Sensor Networks.

PubMed

Dao, Thi-Nga; Yoon, Seokhoon; Kim, Jangyoung

2016-01-05

Many applications in wireless sensor networks (WSNs) require energy consumption to be minimized and the data delivered to the sink within a specific delay. A usual solution for reducing energy consumption is duty cycling, in which nodes periodically switch between sleep and active states. By increasing the duty cycle interval, consumed energy can be reduced more. However, a large duty cycle interval causes a long end-to-end (E2E) packet delay. As a result, the requirement of a specific delay bound for packet delivery may not be satisfied. In this paper, we aim at maximizing the duty cycle while still guaranteeing that the packets arrive at the sink with the required probability, i.e., the required delay-constrained success ratio (DCSR) is achieved. In order to meet this objective, we propose a novel scheduling and forwarding scheme, namely the deadline-aware scheduling and forwarding (DASF) algorithm. In DASF, the E2E delay distribution with the given network model and parameters is estimated in order to determine the maximum duty cycle interval, with which the required DCSR is satisfied. Each node independently selects a wake-up time using the selected interval, and packets are forwarded to a node in the potential forwarding set, which is determined based on the distance between nodes and the sink. DASF does not require time synchronization between nodes, and a node does not need to maintain neighboring node information in advance. Simulation results show that the proposed scheme can satisfy a required delay-constrained success ratio and outperforms existing algorithms in terms of E2E delay and DCSR.

A Deadline-Aware Scheduling and Forwarding Scheme in Wireless Sensor Networks

PubMed Central

Dao, Thi-Nga; Yoon, Seokhoon; Kim, Jangyoung

2016-01-01

Many applications in wireless sensor networks (WSNs) require energy consumption to be minimized and the data delivered to the sink within a specific delay. A usual solution for reducing energy consumption is duty cycling, in which nodes periodically switch between sleep and active states. By increasing the duty cycle interval, consumed energy can be reduced more. However, a large duty cycle interval causes a long end-to-end (E2E) packet delay. As a result, the requirement of a specific delay bound for packet delivery may not be satisfied. In this paper, we aim at maximizing the duty cycle while still guaranteeing that the packets arrive at the sink with the required probability, i.e., the required delay-constrained success ratio (DCSR) is achieved. In order to meet this objective, we propose a novel scheduling and forwarding scheme, namely the deadline-aware scheduling and forwarding (DASF) algorithm. In DASF, the E2E delay distribution with the given network model and parameters is estimated in order to determine the maximum duty cycle interval, with which the required DCSR is satisfied. Each node independently selects a wake-up time using the selected interval, and packets are forwarded to a node in the potential forwarding set, which is determined based on the distance between nodes and the sink. DASF does not require time synchronization between nodes, and a node does not need to maintain neighboring node information in advance. Simulation results show that the proposed scheme can satisfy a required delay-constrained success ratio and outperforms existing algorithms in terms of E2E delay and DCSR. PMID:26742046

Utilization of sentinel lymph node biopsy for uterine cancer.

PubMed

Wright, Jason D; Cham, Stephanie; Chen, Ling; Burke, William M; Hou, June Y; Tergas, Ana I; Desai, Vrunda; Hu, Jim C; Ananth, Cande V; Neugut, Alfred I; Hershman, Dawn L

2017-06-01

To limit the potential short and long-term morbidity of lymphadenectomy, sentinel lymph node biopsy has been proposed for endometrial cancer. The principle of sentinel lymph node biopsy relies on removal of a small number of lymph nodes that are the first drainage basins from a tumor and thus the most likely to harbor tumor cells. While the procedure may reduce morbidity, efficacy data are limited and little is known about how commonly the procedure is performed. We examined the patterns and predictors of use of sentinel lymph node biopsy and outcomes of the procedure in women with endometrial cancer who underwent hysterectomy. We used the Perspective database to identify women with uterine cancer who underwent hysterectomy from 2011 through 2015. Billing and charge codes were used to classify women as having undergone lymphadenectomy, sentinel lymph node biopsy, or no nodal assessment. Multivariable models were used to examine clinical, demographic, and hospital characteristics with use of sentinel lymph node biopsy. Length of stay and cost were compared among the different methods of nodal assessment. Among 28,362 patients, 9327 (32.9%) did not undergo nodal assessment, 17,669 (62.3%) underwent lymphadenectomy, and 1366 (4.8%) underwent sentinel lymph node biopsy. Sentinel lymph node biopsy was performed in 1.3% (95% confidence interval, 1.0-1.6%) of abdominal hysterectomies, 3.4% (95% confidence interval, 2.7-4.1%) of laparoscopic hysterectomies, and 7.5% (95% confidence interval, 7.0-8.0%) of robotic-assisted hysterectomies. In a multivariable model, more recent year of surgery was associated with performance of sentinel lymph node biopsy. Compared to abdominal hysterectomy, those undergoing laparoscopic (adjusted risk ratio, 2.45; 95% confidence interval, 1.89-3.18) and robotic-assisted (adjusted risk ratio, 2.69; 95% confidence interval, 2.19-3.30) hysterectomy were more likely to undergo sentinel lymph node biopsy. Among women who underwent minimally invasive hysterectomy, length of stay and cost were lower for sentinel lymph node biopsy compared to lymphadenectomy. The use of sentinel lymph node biopsy for endometrial cancer increased from 2011 through 2015. The increased use was most notable in women who underwent a robotic-assisted hysterectomy. Copyright © 2017 Elsevier Inc. All rights reserved.

Initial experiences in the photoacoustic detection of melanoma metastases in resected lymph nodes

NASA Astrophysics Data System (ADS)

Grootendorst, D.; Jose, J.; Van der Jagt, P.; Van der Weg, W.; Nagel, K.; Wouters, M.; Van Boven, H.; Van Leeuwen, T. G.; Steenbergen, W.; Ruers, T.; Manohar, S.

2011-03-01

Accurate lymph node analysis is essential to determine the prognosis and treatment of patients suffering from melanoma. The initial results of a tomographic photoacoustic modality to detect melanoma metastases in resected lymph nodes are presented based on phantom models and a human lymph node. The results show melanoma metastases detection is feasible and the setup is capable of distinguishing absorbing structures down to 1 mm. In addition, the use of longer laser wavelengths could result in an image containing a higher contrast ratio. Future research shall be focused on using the melanin characteristics to improve contrast and detection possibilities.

T-cell subsets in lymph nodes identify a subgroup of follicular lymphoma patients with favorable outcome.

PubMed

Magnano, Laura; Martínez, Antonio; Carreras, Joaquim; Martínez-Trillos, Alejandra; Giné, Eva; Rovira, Jordina; Dlouhy, Ivan; Baumann, Tycho; Balagué, Olga; Campo, Elías; López-Guillermo, Armando; Villamor, Neus

2017-04-01

We have analyzed in lymph nodes at diagnosis of 75 patients with follicular lymphoma (FL) the relationship between different T-cell subpopulations, assessed by immunohistochemistry (IHC) and flow cytometry (FC), with the outcome. CD4 + cells were the most abundant T-cells in tumor tissue sections, whilst CD57 + cells were the less frequent. In addition to nonambulatory performance status, advanced stage and FLIPI, low CD4 + CD57 + /CD4 + ratio (p = .041), and low CD4 + /CD8 + ratio (p = .008) predicted poor overall survival (OS). Multivariate analysis showed that CD4 + CD57 + /CD4 + ratio was the most important variable for OS. In conclusion, T-cell subpopulations, including CD4 + CD57 + /CD4 + ratio analyzed by FC, could identify FL patients with favorable outcome.

An Optimized Hidden Node Detection Paradigm for Improving the Coverage and Network Efficiency in Wireless Multimedia Sensor Networks.

PubMed

Alanazi, Adwan; Elleithy, Khaled

2016-09-07

Successful transmission of online multimedia streams in wireless multimedia sensor networks (WMSNs) is a big challenge due to their limited bandwidth and power resources. The existing WSN protocols are not completely appropriate for multimedia communication. The effectiveness of WMSNs varies, and it depends on the correct location of its sensor nodes in the field. Thus, maximizing the multimedia coverage is the most important issue in the delivery of multimedia contents. The nodes in WMSNs are either static or mobile. Thus, the node connections change continuously due to the mobility in wireless multimedia communication that causes an additional energy consumption, and synchronization loss between neighboring nodes. In this paper, we introduce an Optimized Hidden Node Detection (OHND) paradigm. The OHND consists of three phases: hidden node detection, message exchange, and location detection. These three phases aim to maximize the multimedia node coverage, and improve energy efficiency, hidden node detection capacity, and packet delivery ratio. OHND helps multimedia sensor nodes to compute the directional coverage. Furthermore, an OHND is used to maintain a continuous node- continuous neighbor discovery process in order to handle the mobility of the nodes. We implement our proposed algorithms by using a network simulator (NS2). The simulation results demonstrate that nodes are capable of maintaining direct coverage and detecting hidden nodes in order to maximize coverage and multimedia node mobility. To evaluate the performance of our proposed algorithms, we compared our results with other known approaches.

Wireless Energy Harvesting Two-Way Relay Networks with Hardware Impairments.

PubMed

Peng, Chunling; Li, Fangwei; Liu, Huaping

2017-11-13

This paper considers a wireless energy harvesting two-way relay (TWR) network where the relay has energy-harvesting abilities and the effects of practical hardware impairments are taken into consideration. In particular, power splitting (PS) receiver is adopted at relay to harvests the power it needs for relaying the information between the source nodes from the signals transmitted by the source nodes, and hardware impairments is assumed suffered by each node. We analyze the effect of hardware impairments [-20]on both decode-and-forward (DF) relaying and amplify-and-forward (AF) relaying networks. By utilizing the obtained new expressions of signal-to-noise-plus-distortion ratios, the exact analytical expressions of the achievable sum rate and ergodic capacities for both DF and AF relaying protocols are derived. Additionally, the optimal power splitting (OPS) ratio that maximizes the instantaneous achievable sum rate is formulated and solved for both protocols. The performances of DF and AF protocols are evaluated via numerical results, which also show the effects of various network parameters on the system performance and on the OPS ratio design.

Comparison of FDG-PET with MIBI-SPECT in the detection of breast cancer and axillary lymph node metastasis.

PubMed

Yutani, K; Shiba, E; Kusuoka, H; Tatsumi, M; Uehara, T; Taguchi, T; Takai, S I; Nishimura, T

2000-01-01

The purpose of this work was to compare [18F]2-deoxy-2-fluoro-D-glucose (FDG) PET and 99mTc-methoxyisobutylisonitrile (MIBI) SPECT in the detection of breast cancer and axillary lymph node metastasis in the same patients. FDG-PET and MIBI-SPECT were performed within 3 days for 40 women (age range 25-86 years old) with suspected breast cancer, in whom biopsies and/or mastectomies were performed. Both images were visually assessed, and the count ratio between tumor and normal tissue (T/N ratio) was calculated. Thirty-eight patients had breast cancer, and the remaining two had benign breast lesions. The sensitivities of FDG-PET and MIBI-SPECT were 78.9 and 76.3% for breast cancer and 50.0 and 37.5% for axillary lymph node metastasis, respectively. The T/N ratio of breast cancer was significantly higher in FDG-PET (6.01 +/- 3.08 mean +/- SD) than that in MIBI-SPECT (3.48 +/- 1.21) (p = 0.01). Nonmalignant diffuse uptake of FDG in the breasts and the accumulation of MIBI in heart and liver occasionally obscured tumor uptake. These results indicate that MIBI-SPECT is comparable with FDG-PET in detecting breast cancer. Neither FDG-PET nor MIBI-SPECT is sufficiently sensitive to rule out axillary lymph node metastasis.

Electronic correlation effects and the Coulomb gap at finite temperature.

PubMed

Sandow, B; Gloos, K; Rentzsch, R; Ionov, A N; Schirmacher, W

2001-02-26

We have investigated the effect of the long-range Coulomb interaction on the one-particle excitation spectrum of n-type germanium, using tunneling spectroscopy on mechanically controllable break junctions. At low temperatures, the tunnel conductance shows a minimum at zero bias voltage due to the Coulomb gap. Above 1 K, the gap is filled by thermal excitations. This behavior is reflected in the variable-range hopping resistivity measured on the same samples: up to a few degrees Kelvin the Efros-Shklovskii lnR infinity T(-1/2) law is obeyed, whereas at higher temperatures deviations from this law occur. The type of crossover differs from that considered previously in the literature.

Antigen-loaded dendritic cell migration: MR imaging in a pancreatic carcinoma model.

PubMed

Zhang, Zhuoli; Li, Weiguo; Procissi, Daniele; Li, Kangan; Sheu, Alexander Y; Gordon, Andrew C; Guo, Yang; Khazaie, Khashayarsha; Huan, Yi; Han, Guohong; Larson, Andrew C

2015-01-01

To test the following hypotheses in a murine model of pancreatic cancer: (a) Vaccination with antigen-loaded iron-labeled dendritic cells reduces T2-weighted signal intensity at magnetic resonance (MR) imaging within peripheral draining lymph nodes ( LN lymph node s) and (b) such signal intensity reductions are associated with tumor size changes after dendritic cell vaccination. The institutional animal care and use committee approved this study. Panc02 cells were implanted into the flanks of 27 C57BL/6 mice bilaterally. After tumors reached 10 mm, cell viability was evaluated, and iron-labeled dendritic cell vaccines were injected into the left hind footpad. The mice were randomly separated into the following three groups (n = 9 in each): Group 1 was injected with 1 million iron-labeled dendritic cells; group 2, with 2 million cells; and control mice, with 200 mL of phosphate-buffered saline. T1- and T2-weighted MR imaging of labeled dendritic cell migration to draining LN lymph node s was performed before cell injection and 6 and 24 hours after injection. The signal-to-noise ratio ( SNR signal-to-noise ratio ) of the draining LN lymph node s was measured. One-way analysis of variance ( ANOVA analysis of variance ) was used to compare Prussian blue-positive dendritic cell measurements in LN lymph node s. Repeated-measures ANOVA analysis of variance was used to compare in vivo T2-weighted SNR signal-to-noise ratio LN lymph node measurements between groups over the observation time points. Trypan blue assays showed no significant difference in mean viability indexes (unlabeled vs labeled dendritic cells, 4.32% ± 0.69 [standard deviation] vs 4.83% ± 0.76; P = .385). Thirty-five days after injection, the mean left and right flank tumor sizes, respectively, were 112.7 mm(2) ± 16.4 and 109 mm(2) ± 24.3 for the 1-million dendritic cell group, 92.2 mm(2) ± 9.9 and 90.4 mm(2) ± 12.8 for the 2-million dendritic cell group, and 193.7 mm(2) ± 20.9 and 189.4 mm(2) ± 17.8 for the control group (P = .0001 for control group vs 1-million cell group; P = .00007 for control group vs 2-million cell group). There was a correlation between postinjection T2-weighted SNR signal-to-noise ratio decreases in the left popliteal LN lymph node 24 hours after injection and size changes at follow-up for tumors in both flanks (R = 0.81 and R = 0.76 for left and right tumors, respectively). MR imaging approaches can be used for quantitative measurement of accumulated iron-labeled dendritic cell-based vaccines in draining LN lymph node s. The amount of dendritic cell-based vaccine in draining LN lymph node s correlates well with observed protective effects.

Antigen-loaded Dendritic Cell Migration: MR Imaging in a Pancreatic Carcinoma Model

PubMed Central

Li, Weiguo; Procissi, Daniele; Li, Kangan; Sheu, Alexander Y.; Gordon, Andrew C.; Guo, Yang; Khazaie, Khashayarsha; Huan, Yi; Han, Guohong; Larson, Andrew C.

2015-01-01

Purpose To test the following hypotheses in a murine model of pancreatic cancer: (a) Vaccination with antigen-loaded iron-labeled dendritic cells reduces T2-weighted signal intensity at magnetic resonance (MR) imaging within peripheral draining lymph nodes (LNlymph nodes) and (b) such signal intensity reductions are associated with tumor size changes after dendritic cell vaccination. Materials and Methods The institutional animal care and use committee approved this study. Panc02 cells were implanted into the flanks of 27 C57BL/6 mice bilaterally. After tumors reached 10 mm, cell viability was evaluated, and iron-labeled dendritic cell vaccines were injected into the left hind footpad. The mice were randomly separated into the following three groups (n = 9 in each): Group 1 was injected with 1 million iron-labeled dendritic cells; group 2, with 2 million cells; and control mice, with 200 mL of phosphate-buffered saline. T1- and T2-weighted MR imaging of labeled dendritic cell migration to draining LNlymph nodes was performed before cell injection and 6 and 24 hours after injection. The signal-to-noise ratio (SNRsignal-to-noise ratio) of the draining LNlymph nodes was measured. One-way analysis of variance (ANOVAanalysis of variance) was used to compare Prussian blue–positive dendritic cell measurements in LNlymph nodes. Repeated-measures ANOVAanalysis of variance was used to compare in vivo T2-weighted SNRsignal-to-noise ratio LNlymph node measurements between groups over the observation time points. Results Trypan blue assays showed no significant difference in mean viability indexes (unlabeled vs labeled dendritic cells, 4.32% ± 0.69 [standard deviation] vs 4.83% ± 0.76; P = .385). Thirty-five days after injection, the mean left and right flank tumor sizes, respectively, were 112.7 mm2 ± 16.4 and 109 mm2 ± 24.3 for the 1-million dendritic cell group, 92.2 mm2 ± 9.9 and 90.4 mm2 ± 12.8 for the 2-million dendritic cell group, and 193.7 mm2 ± 20.9 and 189.4 mm2 ± 17.8 for the control group (P = .0001 for control group vs 1-million cell group; P = .00007 for control group vs 2-million cell group). There was a correlation between postinjection T2-weighted SNRsignal-to-noise ratio decreases in the left popliteal LNlymph node 24 hours after injection and size changes at follow-up for tumors in both flanks (R = 0.81 and R = 0.76 for left and right tumors, respectively). Conclusion MR imaging approaches can be used for quantitative measurement of accumulated iron-labeled dendritic cell–based vaccines in draining LNlymph nodes. The amount of dendritic cell–based vaccine in draining LNlymph nodes correlates well with observed protective effects. © RSNA, 2014 Online supplemental material is available for this article. PMID:25222066

An Optimized Hidden Node Detection Paradigm for Improving the Coverage and Network Efficiency in Wireless Multimedia Sensor Networks

PubMed Central

Alanazi, Adwan; Elleithy, Khaled

2016-01-01

Successful transmission of online multimedia streams in wireless multimedia sensor networks (WMSNs) is a big challenge due to their limited bandwidth and power resources. The existing WSN protocols are not completely appropriate for multimedia communication. The effectiveness of WMSNs varies, and it depends on the correct location of its sensor nodes in the field. Thus, maximizing the multimedia coverage is the most important issue in the delivery of multimedia contents. The nodes in WMSNs are either static or mobile. Thus, the node connections change continuously due to the mobility in wireless multimedia communication that causes an additional energy consumption, and synchronization loss between neighboring nodes. In this paper, we introduce an Optimized Hidden Node Detection (OHND) paradigm. The OHND consists of three phases: hidden node detection, message exchange, and location detection. These three phases aim to maximize the multimedia node coverage, and improve energy efficiency, hidden node detection capacity, and packet delivery ratio. OHND helps multimedia sensor nodes to compute the directional coverage. Furthermore, an OHND is used to maintain a continuous node– continuous neighbor discovery process in order to handle the mobility of the nodes. We implement our proposed algorithms by using a network simulator (NS2). The simulation results demonstrate that nodes are capable of maintaining direct coverage and detecting hidden nodes in order to maximize coverage and multimedia node mobility. To evaluate the performance of our proposed algorithms, we compared our results with other known approaches. PMID:27618048

The prognostic significance of nonsentinel lymph node metastasis in melanoma.

PubMed

Brown, Russell E; Ross, Merrick I; Edwards, Michael J; Noyes, R Dirk; Reintgen, Douglas S; Hagendoorn, Lee J; Stromberg, Arnold J; Martin, Robert C G; McMasters, Kelly M; Scoggins, Charles R

2010-12-01

We hypothesized that metastasis beyond the sentinel lymph nodes (SLN) to the nonsentinel nodes (NSN) is an important predictor of survival. Analysis was performed of a prospective multi-institutional study that included patients with melanoma ≥ 1.0 mm in Breslow thickness. All patients underwent SLN biopsy; completion lymphadenectomy was performed for all SLN metastases. Disease-free survival (DFS) and overall survival (OS) were computed by Kaplan-Meier analysis; univariate and multivariate analyses were performed to identify factors associated with differences in survival among groups. A total of 2335 patients were analyzed over a median follow-up of 68 months. We compared 3 groups: SLN negative (n = 1988), SLN-only positive (n = 296), and both SLN and NSN positive (n = 51). The 5-year DFS rates were 85.5, 64.8, and 42.6% for groups 1, 2, and 3, respectively (P < 0.001). The 5-year OS rates were 85.5, 64.9, and 49.4%, respectively (P < 0.001). On univariate analysis, predictors of decreased OS included: SLN metastasis, NSN metastasis, increased total number of positive LN, increased ratio of positive LN to total LN, increased age, male gender, increased Breslow thickness, presence of ulceration, Clark level ≥ IV, and axial primary site (in all cases, P < 0.01). When the total number of positive LN and NSN status were evaluated using multivariate analysis, NSN status remained statistically significant (P < 0.01), while the total number of positive LN and LN ratio did not. NSN melanoma metastasis is an independent prognostic factor for DFS and OS, which is distinct from the number of positive lymph nodes or the lymph node ratio.

Best bang for your buck: GPU nodes for GROMACS biomolecular simulations

PubMed Central

Páll, Szilárd; Fechner, Martin; Esztermann, Ansgar; de Groot, Bert L.; Grubmüller, Helmut

2015-01-01

The molecular dynamics simulation package GROMACS runs efficiently on a wide variety of hardware from commodity workstations to high performance computing clusters. Hardware features are well‐exploited with a combination of single instruction multiple data, multithreading, and message passing interface (MPI)‐based single program multiple data/multiple program multiple data parallelism while graphics processing units (GPUs) can be used as accelerators to compute interactions off‐loaded from the CPU. Here, we evaluate which hardware produces trajectories with GROMACS 4.6 or 5.0 in the most economical way. We have assembled and benchmarked compute nodes with various CPU/GPU combinations to identify optimal compositions in terms of raw trajectory production rate, performance‐to‐price ratio, energy efficiency, and several other criteria. Although hardware prices are naturally subject to trends and fluctuations, general tendencies are clearly visible. Adding any type of GPU significantly boosts a node's simulation performance. For inexpensive consumer‐class GPUs this improvement equally reflects in the performance‐to‐price ratio. Although memory issues in consumer‐class GPUs could pass unnoticed as these cards do not support error checking and correction memory, unreliable GPUs can be sorted out with memory checking tools. Apart from the obvious determinants for cost‐efficiency like hardware expenses and raw performance, the energy consumption of a node is a major cost factor. Over the typical hardware lifetime until replacement of a few years, the costs for electrical power and cooling can become larger than the costs of the hardware itself. Taking that into account, nodes with a well‐balanced ratio of CPU and consumer‐class GPU resources produce the maximum amount of GROMACS trajectory over their lifetime. © 2015 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc. PMID:26238484

Best bang for your buck: GPU nodes for GROMACS biomolecular simulations.

PubMed

Kutzner, Carsten; Páll, Szilárd; Fechner, Martin; Esztermann, Ansgar; de Groot, Bert L; Grubmüller, Helmut

2015-10-05

The molecular dynamics simulation package GROMACS runs efficiently on a wide variety of hardware from commodity workstations to high performance computing clusters. Hardware features are well-exploited with a combination of single instruction multiple data, multithreading, and message passing interface (MPI)-based single program multiple data/multiple program multiple data parallelism while graphics processing units (GPUs) can be used as accelerators to compute interactions off-loaded from the CPU. Here, we evaluate which hardware produces trajectories with GROMACS 4.6 or 5.0 in the most economical way. We have assembled and benchmarked compute nodes with various CPU/GPU combinations to identify optimal compositions in terms of raw trajectory production rate, performance-to-price ratio, energy efficiency, and several other criteria. Although hardware prices are naturally subject to trends and fluctuations, general tendencies are clearly visible. Adding any type of GPU significantly boosts a node's simulation performance. For inexpensive consumer-class GPUs this improvement equally reflects in the performance-to-price ratio. Although memory issues in consumer-class GPUs could pass unnoticed as these cards do not support error checking and correction memory, unreliable GPUs can be sorted out with memory checking tools. Apart from the obvious determinants for cost-efficiency like hardware expenses and raw performance, the energy consumption of a node is a major cost factor. Over the typical hardware lifetime until replacement of a few years, the costs for electrical power and cooling can become larger than the costs of the hardware itself. Taking that into account, nodes with a well-balanced ratio of CPU and consumer-class GPU resources produce the maximum amount of GROMACS trajectory over their lifetime. © 2015 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc.

Proactive schema based link lifetime estimation and connectivity ratio.

PubMed

Bachir, Bouamoud; Ali, Ouacha; Ahmed, Habbani; Mohamed, Elkoutbi

2014-01-01

The radio link between a pair of wireless nodes is affected by a set of random factors such as transmission range, node mobility, and environment conditions. The properties of such radio links are continually experienced when nodes status balances between being reachable and being unreachable; thereby on completion of each experience the statistical distribution of link lifetime is updated. This aspect is emphasized in mobile ad hoc network especially when it is deployed in some fields that require intelligent processing of data information such as aerospace domain.

Effect of Abutment Modification and Cement Type on Retention of Cement-Retained Implant Supported Crowns

PubMed Central

Farzin, Mitra; Torabi, Kianoosh; Ahangari, Ahmad Hasan; Derafshi, Reza

2014-01-01

Objective: Provisional cements are commonly used to facilitate retrievability of cement-retained fixed implant restorations; but compromised abutment preparation may affect the retention of implant-retained crowns.The purpose of this study was to investigate the effect of abutment design and type of luting agent on the retentive strength of cement-retained implant restorations. Materials and Method: Two prefabricated abutments were attached to their corresponding analogs and embedded in an acrylic resin block. The first abutment (control group) was left intact without any modifications. The screw access channel for the first abutment was completely filled with composite resin. In the second abutment, (test group) the axial wall was partially removed to form an abutment with 3 walls. Wax models were made by CAD/CAM. Ten cast copings were fabricated for each abutment. The prepared copings were cemented on the abutments by Temp Bond luting agent under standardized conditions (n=20). The assemblies were stored in 100% humidity for one day at 37°C prior to testing. The cast crown was removed from the abutment using an Instron machine, and the peak removal force was recorded. Coping/abutment specimens were cleaned after testing, and the testing procedure was repeated for Dycal luting agent (n=20). Data were analyzed with two- way ANOVA (α=0.05). Results: There was no significant difference in the mean transformed retention (Ln-R) between intact abutments (4.90±0.37) and the abutments with 3 walls (4.83±0.25) using Dycal luting agent. However, in TempBond group, the mean transformed retention (Ln-R) was significantly lower in the intact abutment (3.9±0.23) compared to the abutment with 3 walls (4.13±0.33, P=0.027). Conclusion: The retention of cement-retained implant restoration can be improved by the type of temporary cement used. The retention of cast crowns cemented to implant abutments with TempBond is influenced by the wall removal. PMID:25628660

Recurrence of tuberculosis in a low-incidence setting: a retrospective cross-sectional study augmented by whole genome sequencing.

PubMed

Parvaresh, Laila; Crighton, Taryn; Martinez, Elena; Bustamante, Andrea; Chen, Sharon; Sintchenko, Vitali

2018-06-07

The recurrence of tuberculosis (TB) disease in treated patients can serve as a marker of the efficacy of TB control programs. Recurrent disease represents either endogenous reactivation with the same strain of Mycobacterium tuberculosis due to non-compliance or inadequate therapy or exogenous reinfection with a new strain. Genotyping or whole genome sequencing (WGS) of M. tuberculosis isolates from initial and recurrent cases can differentiate between reinfection and reactivation. This study examined cases of recurrent TB in New South Wales, Australia, using genotyping and WGS. Culture-confirmed TB cases diagnosed at least 12 months apart between January 2011 and December 2016 were included. Isolates of M. tuberculosis from patients were compared using 24-locus Mycobacterial Interspersed Repetitive Unit Variable Number Tandem Repeat (MIRU-24) typing and WGS. Eighteen cases of recurrent disease were identified but isolates from only 15 (83%) were available for study. MIRU-24 findings classified 13 (13/15; 87%) as reactivation and two (13%), as reinfection. Sequencing 13 cultivable paired isolates demonstrated 11 reactivations and two reinfections. There was genomic similarity in 10 out of 13 pairs while one case (1/13; 8%) had 12 SNPS differences. Two other cases (2/13;15%) had > 200 SNPs differences and were classified as reinfection. No phenotypic or genomic evidence of drug resistance was observed. TB control programs can achieve consistently low rates of recurrent disease in low incidence settings. WGS of implicated isolates augments the differentiation between reactivation and reinfection and indicates that the majority of recurrences are due to reactivation rather than reinfection. Predominance of reactivation over reinfection indicates high-quality public health practices and a low risk of local transmission. This study was approved by the Western Sydney Local Health District (WSLHD) Human Research Ethics Committee (HREC Ref: AU RED LNR/17/WMEAD/190; SSA Ref: LNR SSA/17/WMEAD/191).

Estimating Lymphodynamic Conditions and Lymphovenous Anastomosis Efficacy Using 99mTc-phytate Lymphoscintigraphy with SPECT-CT in Patients with Lower-limb Lymphedema

PubMed Central

Fukushima, Yoshimitsu; Kumita, Shinichiro; Ogawa, Rei; Hyakusoku, Hiko

2015-01-01

Background: Diagnostic and therapeutic strategies for lower-limb lymphedema have not yet been established. The purpose of this study was to estimate the lymphodynamic condition and therapeutic efficacy of lymphovenous anastomosis (LVA) in lower-limb lymphedema patients using 2-phase 99mTc-phytate lymphoscintigraphy with single-photon emission computed tomography-computed tomography (SPECT-CT). Methods: In this study, consecutive patients with lower-limb lymphedema who underwent 2-phase lymphoscintigraphy using 99mTc-phytate were enrolled between June 2013 and June 2014. SPECT-CT was also performed to clarify the relationships between functional and morphological information. In both the early and delayed images, inguinal lymph node accumulation, dermal backflow, and their sequential alternations were evaluated, and liver-to-blood ratio and inguinal lymph node-to-blood ratio were calculated. All participants were classified into 6 types of lymphodynamic conditions based on the image findings. Patients with both dermal backflow and associated normal lymphatic vessel accumulation proceeded to LVA and underwent a second lymphoscintigraphy after the operation. Results: Of all 30 participants, the largest population was categorized as type 4, which had consistent inguinal lymph node accumulation defect with dermal backflow. In 12 operated cases, dermal backflow was degraded in 10 cases by LVA. Liver-to-blood ratio in both early and delayed images and inguinal lymph node-to-blood ratio in delayed image significantly increased after LVA. Conclusions: Lymphoscintigraphy with SPECT-CT can provide both functional and morphological information simultaneously in patients with lower-limb lymphedema. Using these procedures, a type categorization for the patients was devised, which reflects their lymphodynamic conditions. The therapeutic efficacy of LVA could also be estimated quantitatively by the derived findings. PMID:26090294

Uncertainty Quantification of Hypothesis Testing for the Integrated Knowledge Engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cuellar, Leticia

2012-05-31

The Integrated Knowledge Engine (IKE) is a tool of Bayesian analysis, based on Bayesian Belief Networks or Bayesian networks for short. A Bayesian network is a graphical model (directed acyclic graph) that allows representing the probabilistic structure of many variables assuming a localized type of dependency called the Markov property. The Markov property in this instance makes any node or random variable to be independent of any non-descendant node given information about its parent. A direct consequence of this property is that it is relatively easy to incorporate new evidence and derive the appropriate consequences, which in general is notmore » an easy or feasible task. Typically we use Bayesian networks as predictive models for a small subset of the variables, either the leave nodes or the root nodes. In IKE, since most applications deal with diagnostics, we are interested in predicting the likelihood of the root nodes given new observations on any of the children nodes. The root nodes represent the various possible outcomes of the analysis, and an important problem is to determine when we have gathered enough evidence to lean toward one of these particular outcomes. This document presents criteria to decide when the evidence gathered is sufficient to draw a particular conclusion or decide in favor of a particular outcome by quantifying the uncertainty in the conclusions that are drawn from the data. The material in this document is organized as follows: Section 2 presents briefly a forensics Bayesian network, and we explore evaluating the information provided by new evidence by looking first at the posterior distribution of the nodes of interest, and then at the corresponding posterior odds ratios. Section 3 presents a third alternative: Bayes Factors. In section 4 we finalize by showing the relation between the posterior odds ratios and Bayes factors and showing examples these cases, and in section 5 we conclude by providing clear guidelines of how to use these for the type of Bayesian networks used in IKE.« less

Distribution of finger nodes and their association with underlying radiographic features of osteoarthritis.

PubMed

Rees, Frances; Doherty, Sally; Hui, Michelle; Maciewicz, Rose; Muir, Kenneth; Zhang, Weiya; Doherty, Michael

2012-04-01

To determine the distribution of clinically palpable hand interphalangeal (IP) nodes at each finger and thumb joint in a population with nodes, the influence of left or right hand dominance and sex on the development of nodes, and the association between nodes and underlying radiographic features of osteoarthritis (OA). We performed a cross-sectional analysis of participants in the Genetics of Osteoarthritis and Lifestyle (GOAL) study who had ≥1 Heberden's nodes or Bouchard's nodes on clinical examination. Frequencies (%) of nodes were described for each IP joint in the hand. Associations between nodes and underlying radiographic OA were shown with odds ratios (ORs) and 95% confidence intervals. A logistic regression model was used to adjust for the following confounding factors: age, sex, body mass index, left or right hand dominance, hand trauma, occupation with heavy manual activity, and participation in sports. Of the 3,170 GOAL participants, 1,939 had ≥1 nodes (mean age 68 years, 54% women). The distal IP joints of the index finger were the most frequently affected, followed by the thumb IP joint. Nodes were more common in dominant hands and women. There was a significant association between nodes and underlying radiographic OA (OR range 2.26-21.23). This association was stronger for joint space narrowing than for osteophytes. A dose-response relationship was found between clinical severity of Heberden's nodes and underlying radiographic change. Our study supports the positive association between nodes and radiographic OA, especially narrowing, and the influence of sex and left or right hand dominance on development of nodes. In this age group, presence of nodes may be taken as an indication of underlying small joint OA. Copyright © 2012 by the American College of Rheumatology.

Tumour thickness as a determinant of nodal metastasis in oral tongue carcinoma.

PubMed

Wang, Kejia; Veivers, David

2017-09-01

Tumour thickness is a strong predictor for cervical node involvement in oral cavity squamous cell carcinomas (SCCs), with a recent meta-analysis concluding a 4-mm optimal prognostic cut-off point. No consensus has been reached for the tumour thickness cut-off for oral tongue SCCs. A retrospective review of prospectively collected data from 112 patients by the Northern Sydney Cancer Centre (Australia) with primary oral tongue SCC was conducted. Tumour thickness was measured by standard histopathological techniques and cervical node involvement was determined either from neck dissection histopathology or by clinical and radiological follow-up. Neck dissection was performed in 78 patients (70%). Tumour thickness was a significant predictor of cervical node disease (P < 0.01), with a median tumour thickness of 5.5 mm. Cervical node metastasis rates for tumours <2, 2-3.9 and ≥4 mm thick were 10%, 42.1% and 46.5%, respectively. The rate of cervical node metastasis was significantly higher for patients with tumours thicker than a cut-off of 2 mm (odds ratio: 7.53, P < 0.01). A 4-mm thickness cut-off was also statistically significant (P < 0.05); however, the odds ratio was smaller at 2.52. Despite some previous evidence for a 4-mm tumour thickness cut-off in oral tongue SCCs, thinner tumours (2-3.9 mm) can also have a propensity for cervical node metastasis. Patients in this category require close monitoring for regional recurrence if they do not have a neck dissection. © 2016 Royal Australasian College of Surgeons.

Greedy data transportation scheme with hard packet deadlines for wireless ad hoc networks.

PubMed

Lee, HyungJune

2014-01-01

We present a greedy data transportation scheme with hard packet deadlines in ad hoc sensor networks of stationary nodes and multiple mobile nodes with scheduled trajectory path and arrival time. In the proposed routing strategy, each stationary ad hoc node en route decides whether to relay a shortest-path stationary node toward destination or a passing-by mobile node that will carry closer to destination. We aim to utilize mobile nodes to minimize the total routing cost as far as the selected route can satisfy the end-to-end packet deadline. We evaluate our proposed routing algorithm in terms of routing cost, packet delivery ratio, packet delivery time, and usability of mobile nodes based on network level simulations. Simulation results show that our proposed algorithm fully exploits the remaining time till packet deadline to turn into networking benefits of reducing the overall routing cost and improving packet delivery performance. Also, we demonstrate that the routing scheme guarantees packet delivery with hard deadlines, contributing to QoS improvement in various network services.

Greedy Data Transportation Scheme with Hard Packet Deadlines for Wireless Ad Hoc Networks

PubMed Central

Lee, HyungJune

2014-01-01

We present a greedy data transportation scheme with hard packet deadlines in ad hoc sensor networks of stationary nodes and multiple mobile nodes with scheduled trajectory path and arrival time. In the proposed routing strategy, each stationary ad hoc node en route decides whether to relay a shortest-path stationary node toward destination or a passing-by mobile node that will carry closer to destination. We aim to utilize mobile nodes to minimize the total routing cost as far as the selected route can satisfy the end-to-end packet deadline. We evaluate our proposed routing algorithm in terms of routing cost, packet delivery ratio, packet delivery time, and usability of mobile nodes based on network level simulations. Simulation results show that our proposed algorithm fully exploits the remaining time till packet deadline to turn into networking benefits of reducing the overall routing cost and improving packet delivery performance. Also, we demonstrate that the routing scheme guarantees packet delivery with hard deadlines, contributing to QoS improvement in various network services. PMID:25258736

The effects of malicious nodes on performance of mobile ad hoc networks

NASA Astrophysics Data System (ADS)

Li, Fanzhi; Shi, Xiyu; Jassim, Sabah; Adams, Christopher

2006-05-01

Wireless ad hoc networking offers convenient infrastructureless communication over the shared wireless channel. However, the nature of ad hoc networks makes them vulnerable to security attacks. Unlike their wired counterpart, infrastructureless ad hoc networks do not have a clear line of defense, their topology is dynamically changing, and every mobile node can receive messages from its neighbors and can be contacted by all other nodes in its neighborhood. This poses a great danger to network security if some nodes behave in a malicious manner. The immediate concern about the security in this type of networks is how to protect the network and the individual mobile nodes against malicious act of rogue nodes from within the network. This paper is concerned with security aspects of wireless ad hoc networks. We shall present results of simulation experiments on ad hoc network's performance in the presence of malicious nodes. We shall investigate two types of attacks and the consequences will be simulated and quantified in terms of loss of packets and other factors. The results show that network performance, in terms of successful packet delivery ratios, significantly deteriorates when malicious nodes act according to the defined misbehaving characteristics.

A Routing Path Construction Method for Key Dissemination Messages in Sensor Networks

PubMed Central

Moon, Soo Young; Cho, Tae Ho

2014-01-01

Authentication is an important security mechanism for detecting forged messages in a sensor network. Each cluster head (CH) in dynamic key distribution schemes forwards a key dissemination message that contains encrypted authentication keys within its cluster to next-hop nodes for the purpose of authentication. The forwarding path of the key dissemination message strongly affects the number of nodes to which the authentication keys in the message are actually distributed. We propose a routing method for the key dissemination messages to increase the number of nodes that obtain the authentication keys. In the proposed method, each node selects next-hop nodes to which the key dissemination message will be forwarded based on secret key indexes, the distance to the sink node, and the energy consumption of its neighbor nodes. The experimental results show that the proposed method can increase by 50–70% the number of nodes to which authentication keys in each cluster are distributed compared to geographic and energy-aware routing (GEAR). In addition, the proposed method can detect false reports earlier by using the distributed authentication keys, and it consumes less energy than GEAR when the false traffic ratio (FTR) is ≥10%. PMID:25136649

Adaptive multi-node multiple input and multiple output (MIMO) transmission for mobile wireless multimedia sensor networks.

PubMed

Cho, Sunghyun; Choi, Ji-Woong; You, Cheolwoo

2013-10-02

Mobile wireless multimedia sensor networks (WMSNs), which consist of mobile sink or sensor nodes and use rich sensing information, require much faster and more reliable wireless links than static wireless sensor networks (WSNs). This paper proposes an adaptive multi-node (MN) multiple input and multiple output (MIMO) transmission to improve the transmission reliability and capacity of mobile sink nodes when they experience spatial correlation. Unlike conventional single-node (SN) MIMO transmission, the proposed scheme considers the use of transmission antennas from more than two sensor nodes. To find an optimal antenna set and a MIMO transmission scheme, a MN MIMO channel model is introduced first, followed by derivation of closed-form ergodic capacity expressions with different MIMO transmission schemes, such as space-time transmit diversity coding and spatial multiplexing. The capacity varies according to the antenna correlation and the path gain from multiple sensor nodes. Based on these statistical results, we propose an adaptive MIMO mode and antenna set switching algorithm that maximizes the ergodic capacity of mobile sink nodes. The ergodic capacity of the proposed scheme is compared with conventional SN MIMO schemes, where the gain increases as the antenna correlation and path gain ratio increase.

Adaptive Multi-Node Multiple Input and Multiple Output (MIMO) Transmission for Mobile Wireless Multimedia Sensor Networks

PubMed Central

Cho, Sunghyun; Choi, Ji-Woong; You, Cheolwoo

2013-01-01

Mobile wireless multimedia sensor networks (WMSNs), which consist of mobile sink or sensor nodes and use rich sensing information, require much faster and more reliable wireless links than static wireless sensor networks (WSNs). This paper proposes an adaptive multi-node (MN) multiple input and multiple output (MIMO) transmission to improve the transmission reliability and capacity of mobile sink nodes when they experience spatial correlation. Unlike conventional single-node (SN) MIMO transmission, the proposed scheme considers the use of transmission antennas from more than two sensor nodes. To find an optimal antenna set and a MIMO transmission scheme, a MN MIMO channel model is introduced first, followed by derivation of closed-form ergodic capacity expressions with different MIMO transmission schemes, such as space-time transmit diversity coding and spatial multiplexing. The capacity varies according to the antenna correlation and the path gain from multiple sensor nodes. Based on these statistical results, we propose an adaptive MIMO mode and antenna set switching algorithm that maximizes the ergodic capacity of mobile sink nodes. The ergodic capacity of the proposed scheme is compared with conventional SN MIMO schemes, where the gain increases as the antenna correlation and path gain ratio increase. PMID:24152920

A Collaborative Secure Localization Algorithm Based on Trust Model in Underwater Wireless Sensor Networks

PubMed Central

Han, Guangjie; Liu, Li; Jiang, Jinfang; Shu, Lei; Rodrigues, Joel J.P.C.

2016-01-01

Localization is one of the hottest research topics in Underwater Wireless Sensor Networks (UWSNs), since many important applications of UWSNs, e.g., event sensing, target tracking and monitoring, require location information of sensor nodes. Nowadays, a large number of localization algorithms have been proposed for UWSNs. How to improve location accuracy are well studied. However, few of them take location reliability or security into consideration. In this paper, we propose a Collaborative Secure Localization algorithm based on Trust model (CSLT) for UWSNs to ensure location security. Based on the trust model, the secure localization process can be divided into the following five sub-processes: trust evaluation of anchor nodes, initial localization of unknown nodes, trust evaluation of reference nodes, selection of reference node, and secondary localization of unknown node. Simulation results demonstrate that the proposed CSLT algorithm performs better than the compared related works in terms of location security, average localization accuracy and localization ratio. PMID:26891300

Lymph Node Micrometastases are Associated with Worse Survival in Patients with Otherwise Node-Negative Hilar Cholangiocarcinoma.

PubMed

Mantel, Hendrik T J; Wiggers, Jim K; Verheij, Joanne; Doff, Jan J; Sieders, Egbert; van Gulik, Thomas M; Gouw, Annette S H; Porte, Robert J

2015-12-01

Lymph node metastases on routine histology are a strong negative predictor for survival after resection of hilar cholangiocarcinoma. Additional immunohistochemistry can detect lymph node micrometastases in patients who are otherwise node negative, but the prognostic value is unsure. The objective of this study was to assess the effect on survival of immunohistochemically detected lymph node micrometastases in patients with node-negative (pN0) hilar cholangiocarcinoma on routine histology. Between 1990 and 2010, a total of 146 patients underwent curative-intent resection of hilar cholangiocarcinoma with regional lymphadenectomy at two university medical centers in the Netherlands. Ninety-one patients (62 %) without lymph node metastases at routine histology were included. Micrometastases were identified by multiple sectioning of all lymph nodes and additional immunostaining with an antibody against cytokeratin 19 (K19). The association with overall survival was assessed in univariable and multivariable analysis. Median follow-up was 48 months. Micrometastases were identified in 16 (5 %) of 324 lymph nodes, corresponding to 11 (12 %) of 91 patients. There were no differences in clinical variables between K19 lymph node-positive and -negative patients. Five-year survival rates in patients with lymph node micrometastases were significantly lower compared to patients without micrometastases (27 vs. 54 %, P = 0.01). Multivariable analysis confirmed micrometastases as an independent prognostic factor for survival (adjusted Hazard ratio 2.4, P = 0.02). Lymph node micrometastases are associated with worse survival after resection of hilar cholangiocarcinoma. Immunohistochemical detection of lymph node micrometastases leads to better staging of patients who were initially diagnosed with node-negative (pN0) hilar cholangiocarcinoma on routine histology.

An improved graph cut segmentation method for cervical lymph nodes on sonograms and its relationship with node's shape assessment.

PubMed

Zhang, Junhua; Wang, Yuanyuan; Shi, Xinling

2009-12-01

A modified graph cut was proposed under the elliptical shape constraint to segment cervical lymph nodes on sonograms, and its effect on the measurement of short axis to long axis ratio (S/L) was investigated by using the relative ultimate measurement accuracy (RUMA). Under the same user inputs, the proposed algorithm successfully segmented all 60 sonograms tested, while the traditional graph cut failed. The mean RUMA resulted from the developed method was comparable to that resulted from the manual segmentation. Results indicated that utilizing the elliptical shape prior could appreciably improve the graph cut for nodes segmentation, and the proposed method satisfied the accuracy requirement of S/L measurement.

Prognostic impacts of postoperative complications in patients with intrahepatic cholangiocarcinoma after curative operations.

PubMed

Miyata, Tatsunori; Yamashita, Yo-Ichi; Yamao, Takanobu; Umezaki, Naoki; Tsukamoto, Masayo; Kitano, Yuki; Yamamura, Kensuke; Arima, Kota; Kaida, Takayoshi; Nakagawa, Shigeki; Imai, Katsunori; Hashimoto, Daisuke; Chikamoto, Akira; Ishiko, Takatoshi; Baba, Hideo

2017-06-01

The postoperative complication is one of an indicator of poor prognosis in patients with several gastroenterological cancers after curative operations. We, herein, examined prognostic impacts of postoperative complications in patients with intrahepatic cholangiocarcinoma after curative operations. We retrospectively analyzed 60 patients with intrahepatic cholangiocarcinoma who underwent primary curative operations from June 2002 to February 2016. Prognostic impacts of postoperative complications were analyzed using log-rank test and Cox proportional hazard model. Postoperative complications (Clavien-Dindo classification grade 3 or more) occurred in 13 patients (21.7%). Overall survival of patients without postoperative complications was significantly better than that of patients with postoperative complications (p = 0.025). Postoperative complications are independent prognostic factor of overall survival (hazard ratio 3.02; p = 0.030). In addition, bile duct resection and reconstruction (Odds ratio 59.1; p = 0.002) and hepatitis C virus antibody positive (Odds ratio 7.14; p= 0.022), and lymph node dissection (Odds ratio 6.28; p = 0.040) were independent predictors of postoperative complications. Postoperative complications may be an independent predictor of poorer survival in patients with intrahepatic cholangiocarcinoma after curative operations. Lymph node dissection and bile duct resection and reconstruction were risk factors for postoperative complications, therefore we should pay attentions to perform lymph node dissections, bile duct resection and reconstruction in patients with intrahepatic cholangiocarcinoma.

Superasymmetric fission of heavy nuclei induced by intermediate-energy protons

NASA Astrophysics Data System (ADS)

Deppman, A.; Andrade-II, E.; Guimarães, V.; Karapetyan, G. S.; Tavares, O. A. P.; Balabekyan, A. R.; Demekhina, N. A.; Adam, J.; Garcia, F.; Katovsky, K.

2013-12-01

In this work we present the results for the investigation of intermediate-mass fragment (IMF) production with the proton-induced reaction at 660 MeV on 238U and 237Np target. The data were obtained with the LNR Phasotron U-400M Cyclotron at Joint Institute for Nuclear Research (JINR), Dubna, Russia. A total of 93 isotopes, in the mass range of 30

SOUNET: Self-Organized Underwater Wireless Sensor Network.

PubMed

Kim, Hee-Won; Cho, Ho-Shin

2017-02-02

In this paper, we propose an underwater wireless sensor network (UWSN) named SOUNET where sensor nodes form and maintain a tree-topological network for data gathering in a self-organized manner. After network topology discovery via packet flooding, the sensor nodes consistently update their parent node to ensure the best connectivity by referring to the timevarying neighbor tables. Such a persistent and self-adaptive method leads to high network connectivity without any centralized control, even when sensor nodes are added or unexpectedly lost. Furthermore, malfunctions that frequently happen in self-organized networks such as node isolation and closed loop are resolved in a simple way. Simulation results show that SOUNET outperforms other conventional schemes in terms of network connectivity, packet delivery ratio (PDR), and energy consumption throughout the network. In addition, we performed an experiment at the Gyeongcheon Lake in Korea using commercial underwater modems to verify that SOUNET works well in a real environment.

SOUNET: Self-Organized Underwater Wireless Sensor Network

PubMed Central

Kim, Hee-won; Cho, Ho-Shin

2017-01-01

In this paper, we propose an underwater wireless sensor network (UWSN) named SOUNET where sensor nodes form and maintain a tree-topological network for data gathering in a self-organized manner. After network topology discovery via packet flooding, the sensor nodes consistently update their parent node to ensure the best connectivity by referring to the time-varying neighbor tables. Such a persistent and self-adaptive method leads to high network connectivity without any centralized control, even when sensor nodes are added or unexpectedly lost. Furthermore, malfunctions that frequently happen in self-organized networks such as node isolation and closed loop are resolved in a simple way. Simulation results show that SOUNET outperforms other conventional schemes in terms of network connectivity, packet delivery ratio (PDR), and energy consumption throughout the network. In addition, we performed an experiment at the Gyeongcheon Lake in Korea using commercial underwater modems to verify that SOUNET works well in a real environment. PMID:28157164

Clinical significance of lymph node metastasis in gastric cancer

PubMed Central

Deng, Jing-Yu; Liang, Han

2014-01-01

Gastric cancer, one of the most common malignancies in the world, frequently reveals lymph node, peritoneum, and liver metastases. Most of gastric cancer patients present with lymph node metastasis when they were initially diagnosed or underwent surgical resection, which results in poor prognosis. Both the depth of tumor invasion and lymph node involvement are considered as the most important prognostic predictors of gastric cancer. Although extended lymphadenectomy was not considered a survival benefit procedure and was reported to be associated with high mortality and morbidity in two randomized controlled European trials, it showed significant superiority in terms of lower locoregional recurrence and disease related deaths compared to limited lymphadenectomy in a 15-year follow-up study. Almost all clinical investigators have reached a consensus that the predictive efficiency of the number of metastatic lymph nodes is far better than the extent of lymph node metastasis for the prognosis of gastric cancer worldwide, but other nodal metastatic classifications of gastric cancer have been proposed as alternatives to the number of metastatic lymph nodes for improving the predictive efficiency for patient prognosis. It is still controversial over whether the ratio between metastatic and examined lymph nodes is superior to the number of metastatic lymph nodes in prognostic evaluation of gastric cancer. Besides, the negative lymph node count has been increasingly recognized to be an important factor significantly associated with prognosis of gastric cancer. PMID:24744586

Lymph Node Yield as a Predictor of Survival in Pathologically Node Negative Oral Cavity Carcinoma.

PubMed

Lemieux, Aaron; Kedarisetty, Suraj; Raju, Sharat; Orosco, Ryan; Coffey, Charles

2016-03-01

Even after a pathologically node-negative (pN0) neck dissection for oral cavity squamous cell carcinoma (SCC), patients may develop regional recurrence. In this study, we (1) hypothesize that an increased number of lymph nodes removed (lymph node yield) in patients with pN0 oral SCC predicts improved survival and (2) explore predictors of survival in these patients using a multivariable model. Case series with chart review. Administrative database analysis. The SEER database was queried for patients diagnosed with all-stage oral cavity SCC between 1988 and 2009 who were determined to be pN0 after elective lymph node dissection. Demographic and treatment variables were extracted. The association of lymph node yield with 5-year all-cause survival was studied with multivariable survival analyses. A total of 4341 patients with pN0 oral SCC were included in this study. The 2 highest lymph node yield quartiles (representing >22 nodes removed) were found to be significant predictors of overall survival (22-35 nodes: hazard ratio [HR] = 0.854, P = .031; 36-98 nodes: HR = 0.827, P = .010). Each additional lymph node removed during neck dissection was associated with increased survival (HR = 0.995, P = .022). These data suggest that patients with oral SCC undergoing elective neck dissection may experience an overall survival benefit associated with greater lymph node yield. Mechanisms behind the demonstrated survival advantage are unknown. Larger nodal dissections may remove a greater burden of microscopic metastatic disease, diminishing the likelihood of recurrence. Lymph node yield may serve as an objective measure of the adequacy of lymphadenectomy. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

A dual-modal magnetic nanoparticle probe for preoperative and intraoperative mapping of sentinel lymph nodes by magnetic resonance and near infrared fluorescence imaging

PubMed Central

Zhou, Zhengyang; Chen, Hongwei; Lipowska, Malgorzata; Wang, Liya; Yu, Qiqi; Yang, Xiaofeng; Tiwari, Diana; Yang, Lily; Mao, Hui

2016-01-01

The ability to reliably detect sentinel lymph nodes for sentinel lymph node biopsy and lymphadenectomy is important in clinical management of patients with metastatic cancers. However, the traditional sentinel lymph node mapping with visible dyes is limited by the penetration depth of light and fast clearance of the dyes. On the other hand, sentinel lymph node mapping with radionucleotide technique has intrinsically low spatial resolution and does not provide anatomic details in the sentinel lymph node mapping procedure. This work reports the development of a dual modality imaging probe with magnetic resonance and near infrared imaging capabilities for sentinel lymph node mapping using magnetic iron oxide nanoparticles (10 nm core size) conjugated with a near infrared molecule with emission at 830 nm. Accumulation of magnetic iron oxide nanoparticles in sentinel lymph nodes leads to strong T2 weighted magnetic resonance imaging contrast that can be potentially used for preoperative localization of sentinel lymph nodes, while conjugated near infrared molecules provide optical imaging tracking of lymph nodes with a high signal to background ratio. The new magnetic nanoparticle based dual imaging probe exhibits a significant longer lymph node retention time. Near infrared signals from nanoparticle conjugated near infrared dyes last up to 60 min in sentinel lymph node compared to that of 25 min for the free near infrared dyes in a mouse model. Furthermore, axillary lymph nodes, in addition to sentinel lymph nodes, can be also visualized with this probe, given its slow clearance and sufficient sensitivity. Therefore, this new dual modality imaging probe with the tissue penetration and sensitive detection of sentinel lymph nodes can be applied for preoperative survey of lymph nodes with magnetic resonance imaging and allows intraoperative sentinel lymph node mapping using near infrared optical devices. PMID:23812946

A 16 Yin Yang gene expression ratio signature for ER+/node- breast cancer.

PubMed

Xu, Wayne; Jia, Gaofeng; Cai, Nianguang; Huang, Shujun; Davie, James R; Pitz, Marshall; Banerji, Shantanu; Murphy, Leigh

2017-03-15

Breast cancer is one of the leading causes of cancer death in women. It is a complex and heterogeneous disease with different clinical outcomes. Stratifying patients into subgroups with different outcomes could help guide clinical decision making. In this study, we used two opposing groups of genes, Yin and Yang, to develop a prognostic expression ratio signature. Using the METABRIC cohort we identified a16-gene signature capable of stratifying breast cancer patients into four risk levels with intention that low-risk patients would not undergo adjuvant systemic therapy, intermediate-low-risk patients will be treated with hormonal therapy only, and intermediate-high- and high-risk groups will be treated by chemotherapy in addition to the hormonal therapy. The 16-gene signature for four risk level stratifications of breast cancer patients has been validated using 14 independent datasets. Notably, the low-risk group (n = 51) of 205 estrogen receptor-positive and node negative (ER+/node-) patients from three different datasets who had not had any systemic adjuvant therapy had 100% 15-year disease-specific survival rate. The Concordance Index of YMR for ER+/node negative patients is close to the commercially available signatures. However, YMR showed more significance (HR = 3.7, p = 8.7e-12) in stratifying ER+/node- subgroup than OncotypeDx (HR = 2.7, p = 1.3e-7), MammaPrint (HR = 2.5, p = 5.8e-7), rorS (HR = 2.4, p = 1.4e-6), and NPI (HR = 2.6, p = 1.2e-6). YMR signature may be developed as a clinical tool to select a subgroup of low-risk ER+/node- patients who do not require any adjuvant hormonal therapy (AHT). © 2016 UICC.

Incorporation of N0 Stage with Insufficient Numbers of Lymph Nodes into N1 Stage in the Seventh Edition of the TNM Classification Improves Prediction of Prognosis in Gastric Cancer: Results of a Single-Institution Study of 1258 Chinese Patients.

PubMed

Li, Bofei; Li, Yuanfang; Wang, Wei; Qiu, Haibo; Seeruttun, Sharvesh Raj; Fang, Cheng; Chen, Yongming; Liang, Yao; Li, Wei; Chen, Yingbo; Sun, Xiaowei; Guan, Yuanxiang; Zhan, Youqing; Zhou, Zhiwei

2016-01-01

This study examined the prognosis of the "node-negative with eLNs ≤ 15" designation and the additional value of incorporating it into the pN1 designation in the seventh edition of the N classification. From January 2000 to September 2010, a total of 1258 gastric cancer patients (patients with eLNs > 15 or node-negative with eLNs ≤ 15) undergoing radical gastric resection were enrolled in this study. We incorporated node-negative patients with eLNs ≤ 15 into pN1 and compared this designation with the current 7th edition UICC N stage for 3, 5-year overall survival by univariate and multivariate analysis. Homogeneity, discriminatory ability, and monotonicity of gradients in the hypothetical N stage and the UICC N stage were compared using linear trend χ2, likelihood ratio χ2 statistics, and Akaike information criterion (AIC) calculations. Node-negative patients with eLNs ≤ 15 had worse survival compared with those with eLNs > 15. In univariate and multivariate analyses, the hypothetical N stage showed superiority to the 7th edition pN staging. The hypothetical staging system had higher linear trend and likelihood ratio χ (2) scores and smaller AIC values compared with those for the TNM system, which represented the optimum prognostic stratification. Node-negative patients with eLNs ≤ 15 can be considered to be incorporated into the pN1 stage in the 7th edition of the TNM classification.

Ventral Striatum Functional Connectivity as a Predictor of Adolescent Depressive Disorder in a Longitudinal Community-Based Sample.

PubMed

Pan, Pedro Mario; Sato, João R; Salum, Giovanni A; Rohde, Luis A; Gadelha, Ary; Zugman, Andre; Mari, Jair; Jackowski, Andrea; Picon, Felipe; Miguel, Eurípedes C; Pine, Daniel S; Leibenluft, Ellen; Bressan, Rodrigo A; Stringaris, Argyris

2017-11-01

Previous studies have implicated aberrant reward processing in the pathogenesis of adolescent depression. However, no study has used functional connectivity within a distributed reward network, assessed using resting-state functional MRI (fMRI), to predict the onset of depression in adolescents. This study used reward network-based functional connectivity at baseline to predict depressive disorder at follow-up in a community sample of adolescents. A total of 637 children 6-12 years old underwent resting-state fMRI. Discovery and replication analyses tested intrinsic functional connectivity (iFC) among nodes of a putative reward network. Logistic regression tested whether striatal node strength, a measure of reward-related iFC, predicted onset of a depressive disorder at 3-year follow-up. Further analyses investigated the specificity of this prediction. Increased left ventral striatum node strength predicted increased risk for future depressive disorder (odds ratio=1.54, 95% CI=1.09-2.18), even after excluding participants who had depressive disorders at baseline (odds ratio=1.52, 95% CI=1.05-2.20). Among 11 reward-network nodes, only the left ventral striatum significantly predicted depression. Striatal node strength did not predict other common adolescent psychopathology, such as anxiety, attention deficit hyperactivity disorder, and substance use. Aberrant ventral striatum functional connectivity specifically predicts future risk for depressive disorder. This finding further emphasizes the need to understand how brain reward networks contribute to youth depression.

Adjuvant chemotherapy in lymph node positive bladder cancer.

PubMed

Gofrit, Ofer N; Stadler, Walter M; Zorn, Kevin C; Lin, Shang; Silvestre, Josephine; Shalhav, Arieh L; Zagaja, Gregory P; Steinberg, Gary D

2009-01-01

Lymph node-positive bladder cancer is a systemic disease in the majority of patients. Adjuvant chemotherapy given shortly after surgery, when tumor burden is low, seems reasonable, yet there is no proof that it improves survival. In this retrospective study, we compare the outcomes of patients with microscopic lymph node positive bladder cancer (pN1 or pN2) treated with radical cystectomy followed by adjuvant chemotherapy and those who declined chemotherapy. Sixty-seven patients with lymph node positive bladder cancer (26 pN1 and 41 pN2) who underwent radical cystectomy between April 1995 and April 2005 were reviewed. Combined adjuvant chemotherapy (gemcitabine and cisplatin in most patients) was given to 35 patients (52%), but declined by 32 (48%). The two groups were similar in performance status, postoperative complication rate, and N stage but deferring patients were on average 5 years older and had a more advanced T stage. Study primary endpoint was overall survival (OS). Adjuvant chemotherapy was well tolerated and 28/35 patients (80%) completed all 4 cycles. Median OS of patients given adjuvant chemotherapy was 48 months compared with 8 months for declining patients (hazard ratio 0.13, 95% CI 0.04-0.4, P < 0.0001). Multivariate age adjusted analysis showed that adjuvant chemotherapy was an independent factor affecting OS (hazard ratio 0.2, P < 0.0001). This study supports the use of adjuvant chemotherapy after radical cystectomy in patients with node positive bladder cancer. Study design and patient imbalances make it impossible to draw definitive conclusions.

Simultaneous energy harvesting and information processing in wireless multiple relays with multiple antennas

NASA Astrophysics Data System (ADS)

Albaaj, Azhar; Makki, S. Vahab A.; Alabkhat, Qassem; Zahedi, Abdulhamid

2017-07-01

Wireless networks suffer from battery discharging specially in cooperative communications when multiple relays have an important role but they are energy constrained. To overcome this problem, energy harvesting from radio frequency signals is applied to charge the node battery. These intermediate nodes have the ability to harvest energy from the source signal and use the energy harvested to transmit information to the destination. In fact, the node tries to harvest energy and then transmit the data to destination. Division of energy harvesting and data transmission can be done in two algorithms: time-switching-based relaying protocol and power-splitting-based relaying protocol. These two algorithms also can be applied in delay-limited and delay-tolerant transmission systems. The previous works have assumed a single relay for energy harvesting, but in this article, the proposed method is concentrated on improving the outage probability and throughput by using multiple antennas in each relay node instead of using single antenna. According to our simulation results, when using multi-antenna relays, ability of energy harvesting is increased and thus system performance will be improved to great extent. Maximum ratio combining scheme has been used when the destination chooses the best signal of relays and antennas satisfying the required signal-to-noise ratio.

Prostaglandin E2 Prevents Ovariectomy-Induced Cancellous Bone Loss in Rats

NASA Technical Reports Server (NTRS)

Ke, Hua Zhu; Li, Mei; Jee, Webster S. S.

1992-01-01

The object of this study was to determine whether prostaglandin E2, (PGE2) can prevent ovariectomy induced cancellous bone loss. Thirty-five 3-month-old female Sprague-Dawley rats were divided into two groups. The rats in the first group were ovariectomized (OVX) while the others received sham operation (sham-OVX). The OVX group was further divided into three treatment groups. The daily doses for the three groups were 0,1 and 6 mg PGE2/kg for 90 days. Bone histomorphometric analyses were performed on double-fluorescent-labeled undecalcified proximal tibial metaphysis (PTM). We confirmed that OVX induces massive cancellous bone loss (-80%) and a higher bone turnover (+143%). The new findings from the present study demonstrate that bone loss due to ovarian hormone deficiency can be prevented by a low-dose (1 mg) daily administration of PGE2. Furthermore, a higher-dose (6 mg) daily administration of PGE2 not only prevents bone loss but also adds extra bone to the proximal tibial metaphyses. PGE, at the 1-mg dose level significantly increased trabecular bone area, trabecular width, trabecular node density, density of node to node, ratio of node to free end, and thus significantly decreased trabecular separation from OVX controls. At this dose level, these same parameters did not differ significantly from sham-OVX controls. However, at the 6-mg dose level PGE2, there were significant increases in trabecular bone area, trabecular width, trabecular node density, density of node to node, and ratio of node to free end, while there was significant decrease in trabecular separation from both OVX and sham-operated controls. The changes in indices of trabecular bone microanatomical structure indicated that PGE2 prevented bone loss as well as the disconnection of existing trabeculae. In summary, PGE2, administration to OVX rats decreased bone turnover and increased bone formation parameters resulting in a positive bone balance that prevented bone loss (in both lower and higher doses) and added extra bone to metaphyses of OVX rats (in higher dose). These findings support the strategy of the use of bone stimulation agents in the prevention of estrogen depletion bone loss (postmenopausal osteoporosis).

Novel Indocyanine Green-Phytate Colloid Technique for Sentinel Node Detection in Head and Neck: Mouse Study.

PubMed

Araki, Koji; Mizokami, Daisuke; Tomifuji, Masayuki; Yamashita, Taku; Ohnuki, Kazunobu; Umeda, Izumi O; Fujii, Hirofumi; Kosuda, Shigeru; Shiotani, Akihiro

2014-08-01

Sentinel node navigation surgery using real-time, near-infrared imaging with indocyanine green is becoming popular by allowing head and neck surgeons to avoid unnecessary neck dissection. The major drawback of this method is its quick migration through the lymphatics, limiting the diagnostic time window and undesirable detection of downstream nodes. We resolved this problem by mixing indocyanine green (ICG) with phytate colloid to retard its migration and demonstrated its feasibility in a nude mouse study. Experimental prospective animal study. Animal laboratory. Indocyanine green at 3 concentrations was tested to determine the optimal concentration for sentinel lymph node detection in a mouse model. Effect of indocyanine green with phytate colloid mixture solutions was also analyzed. Indocyanine green or mixture solution at different mixing ratios were injected into the tongue of nude mice and near-infrared fluorescence images were captured sequentially for up to 48 hours. The brightness of fluorescence in the sentinel lymph node and lymph nodes further downstream were assessed. Indocyanine green concentration >50 μg/mL did not improve sentinel lymph node detection. The addition of phytate colloid to indocyanine green extended the period when sentinel lymph node was detectable. Second echelon lymph nodes were not imaged in mice injected with the mixture, while these were visualized in mice injected with indocyanine green alone. This novel technique of ICG-phytate colloid mixture allows prolonged diagnostic time window, prevention of downstream subsequent nodes detection, and improved accuracy for the detection of true sentinel lymph nodes. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2014.

The data-driven null models for information dissemination tree in social networks

NASA Astrophysics Data System (ADS)

Zhang, Zhiwei; Wang, Zhenyu

2017-10-01

For the purpose of detecting relatedness and co-occurrence between users, as well as the distribution features of nodes in spreading path of a social network, this paper explores topological characteristics of information dissemination trees (IDT) that can be employed indirectly to probe the information dissemination laws within social networks. Hence, three different null models of IDT are presented in this article, including the statistical-constrained 0-order IDT null model, the random-rewire-broken-edge 0-order IDT null model and the random-rewire-broken-edge 2-order IDT null model. These null models firstly generate the corresponding randomized copy of an actual IDT; then the extended significance profile, which is developed by adding the cascade ratio of information dissemination path, is exploited not only to evaluate degree correlation of two nodes associated with an edge, but also to assess the cascade ratio of different length of information dissemination paths. The experimental correspondences of the empirical analysis for several SinaWeibo IDTs and Twitter IDTs indicate that the IDT null models presented in this paper perform well in terms of degree correlation of nodes and dissemination path cascade ratio, which can be better to reveal the features of information dissemination and to fit the situation of real social networks.

Rapid detection of metastatic melanoma in lymph nodes using proton magnetic resonance spectroscopy of fine needle aspiration biopsy specimens.

PubMed

Lean, Cynthia L; Bourne, Roger; Thompson, John F; Scolyer, Richard A; Stretch, Jonathan; Li, Ling-Xi Lawrence; Russell, Peter; Mountford, Carolyn

2003-06-01

Accurate staging of patients with primary cutaneous melanoma includes assessment of regional lymph nodes for the presence of micrometastatic disease. Sentinel lymph node biopsy is highly accurate but is an invasive surgical procedure with a 5-10% complication rate, and requires labour-intensive and expensive histological examination to identify disease. A rapid, accurate and cost-effective non-surgical technique able to detect micrometastatic deposits of melanoma in regional lymph nodes would be of great benefit. Fine needle aspiration biopsies and tissue specimens were obtained from lymph nodes from 18 patients undergoing node resection for metastatic melanoma and five patients undergoing radical retropubic prostatectomy. One-dimensional proton magnetic resonance spectroscopy was undertaken at 360 MHz (8.5 T). Lymph nodes were cut into 3 mm thick slices and embedded. Four sequential 5 microm tissue sections were cut from each block and stained, with haematoxylin and eosin, for S100 protein, for HMB45, and again with haematoxylin and eosin, respectively. Proton magnetic resonance spectroscopy distinguished between benign and malignant lymph node tissue (P < 0.001, separate t-test) and benign and malignant lymph node fine needle aspiration biopsy (P < 0.012) based on the ratio of the integrals of resonances from lipid/other metabolites (1.8-2.5 p.p.m. region) and 'choline' (3.1-3.3 p.p.m. region). In conclusion, one-dimensional proton magnetic resonance spectroscopy on a simple fine needle aspiration biopsy can distinguish lymph nodes containing metastatic melanoma from uninvolved nodes, providing a rapid, accurate and cost-effective non-surgical technique to assess regional lymph nodes in patients with melanoma.

Distinguishing manipulated stocks via trading network analysis

NASA Astrophysics Data System (ADS)

Sun, Xiao-Qian; Cheng, Xue-Qi; Shen, Hua-Wei; Wang, Zhao-Yang

2011-10-01

Manipulation is an important issue for both developed and emerging stock markets. For the study of manipulation, it is critical to analyze investor behavior in the stock market. In this paper, an analysis of the full transaction records of over a hundred stocks in a one-year period is conducted. For each stock, a trading network is constructed to characterize the relations among its investors. In trading networks, nodes represent investors and a directed link connects a stock seller to a buyer with the total trade size as the weight of the link, and the node strength is the sum of all edge weights of a node. For all these trading networks, we find that the node degree and node strength both have tails following a power-law distribution. Compared with non-manipulated stocks, manipulated stocks have a high lower bound of the power-law tail, a high average degree of the trading network and a low correlation between the price return and the seller-buyer ratio. These findings may help us to detect manipulated stocks.

Performance of an anisotropic Allman/DKT 3-node thin triangular flat shell element

NASA Astrophysics Data System (ADS)

Ertas, A.; Krafcik, J. T.; Ekwaro-Osire, S.

1992-05-01

A simple, explicit formulation of the stiffness matrix for an anisotropic, 3-node, thin triangular flat shell element in global coordinates is presented. An Allman triangle (AT) is used for membrane stiffness. The membrane stiffness matrix is explicitly derived by applying an Allman transformation to a Felippa 6-node linear strain triangle (LST). Bending stiffness is incorporated by the use of a discrete Kirchhoff triangle (DKT) bending element. Stiffness terms resulting from anisotropic membrane-bending coupling are included by integrating, in area coordinates, the membrane and bending strain-displacement matrices. Using the aforementioned approach, the objective of this study is to develop and test the performance of a practical 3-node flat shell element that could be used in plate problems with unsymmetrically stacked composite laminates. The performance of the latter element is tested on plates of varying aspect ratios. The developed 3-node shell element should simplify the programming task and have the potential of reducing the computational time.

Immune response in melanoma: an in-depth analysis of the primary tumor and corresponding sentinel lymph node

PubMed Central

Ma, Michelle W.; Medicherla, Ratna C.; Qian, Meng; de Miera, Eleazar Vega-Saenz; Friedman, Erica B.; Berman, Russell S.; Shapiro, Richard L.; Pavlick, Anna C.; Ott, Patrick A.; Bhardwaj, Nina; Shao, Yongzhao; Osman, Iman; Darvishian, Farbod

2013-01-01

The sentinel lymph node is the initial site of metastasis. Down-regulation of anti-tumor immunity plays a role in nodal progression. Our objective was to investigate the relationship between immune modulation and sentinel lymph node positivity, correlating it with outcome in melanoma patients. Lymph node/primary tissues from melanoma patients prospectively accrued and followed at New York University Medical Center were evaluated for the presence of regulatory T-cells (Foxp3+) and dendritic cells (conventional: CD11c+, mature: CD86+) using immunohistochemistry. Primary melanoma immune cell profiles from sentinel lymph node-positive/-negative patients were compared. Logistic regression models inclusive of standard-of-care/immunologic primary tumor characteristics were constructed to predict the risk of sentinel lymph node positivity. Immunological responses in the positive sentinel lymph node were also compared to those in the negative non-sentinel node from the same nodal basin and matched negative sentinel lymph node. Decreased immune response was defined as increased regulatory T-cells or decreased dendritic cells. Associations between the expression of these immune modulators, clinicopathologic variables, and clinical outcome were evaluated using univariate/multivariate analyses. Primary tumor conventional dendritic cells and regression were protective against sentinel lymph node metastasis (odds ratio=0.714, 0.067; P=0.0099, 0.0816, respectively). Anti-tumor immunity was down-regulated in the positive sentinel lymph node with an increase in regulatory T-cells compared to the negative non-sentinel node from the same nodal basin (P=0.0005) and matched negative sentinel lymph node (P=0.0002). The positive sentinel lymph node also had decreased numbers of conventional dendritic cells compared to the negative sentinel lymph node (P<0.0001). Adding sentinel lymph node regulatory T-cell expression improved the discriminative power of a recurrence risk assessment model using clinical stage. Primary tumor regression was associated with prolonged disease-free (P=0.025) and melanoma-specific (P=0.014) survival. Our results support an assessment of local immune profiles in both the primary tumor and sentinel lymph node to help guide therapeutic decisions. PMID:22425909

Modeling and optimization of Quality of Service routing in Mobile Ad hoc Networks

NASA Astrophysics Data System (ADS)

Rafsanjani, Marjan Kuchaki; Fatemidokht, Hamideh; Balas, Valentina Emilia

2016-01-01

Mobile ad hoc networks (MANETs) are a group of mobile nodes that are connected without using a fixed infrastructure. In these networks, nodes communicate with each other by forming a single-hop or multi-hop network. To design effective mobile ad hoc networks, it is important to evaluate the performance of multi-hop paths. In this paper, we present a mathematical model for a routing protocol under energy consumption and packet delivery ratio of multi-hop paths. In this model, we use geometric random graphs rather than random graphs. Our proposed model finds effective paths that minimize the energy consumption and maximizes the packet delivery ratio of the network. Validation of the mathematical model is performed through simulation.

Mitotic rate is associated with positive lymph nodes in patients with thin melanomas.

PubMed

Wheless, Lee; Isom, Chelsea A; Hooks, Mary A; Kauffmann, Rondi M

2018-05-01

The American Joint Commission on Cancer will remove mitotic rate from its staging guidelines in 2018. Using a large nationally representative cohort, we examined the association between mitotic rate and lymph node positivity among thin melanomas. A total of 149,273 thin melanomas in the National Cancer Database were examined for their association of high-risk features of mitotic rate, ulceration, and Breslow depth with lymph node status. Among 17,204 patients with thin melanomas with data on Breslow depth, ulceration, and mitotic rate who underwent a lymph node biopsy, there was a strong linear relationship between odds of having a positive lymph node and mitotic rate (R 2  = 0.96, P < .0001, β = 3.31). The odds of having a positive node increased by 19% with each 1-point increase in mitotic rate (odds ratio, 1.19; 95% confidence interval, 1.17-1.21). Cases with negative nodes had a mean mitotic rate of 1.54 plus or minus 2.07 mitoses/mm 2 compared with 3.30 plus or minus 3.54 mitoses/mm 2 for those with positive nodes (P < .0001). The data collected do not allow for survival analyses. Mitotic rate was strongly associated with the odds of having a positive lymph node and should continue to be reported on pathology reports. Copyright © 2017 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

Contribution of Kinetic Characteristics of Axillary Lymph Nodes to the Diagnosis in Breast Magnetic Resonance Imaging

PubMed Central

Örgüç, Şebnem; Başara, Işıl; Pekindil, Gökhan; Coşkun, Teoman

2012-01-01

Objective: To assess the contribution of kinetic characteristics in the discrimination of malignant-benign axillary lymph nodes. Material and Methods: One hundred fifty-five female patients were included in the study. Following magnetic resonance imaging (MRI) examinations postprocessing applications were applied, dynamic curves were obtained from subtracted images. Types of dynamic curves were correlated with histopathological results in malignant cases or final clinical results in patients with no evidence of malignancy. Sensitivity, specificity, positive likehood ratio (+LHR), negative (−LHR) of dynamic curves characterizing the axillary lymph nodes were calculated. Results: A total of 178 lymph nodes greater than 8 mm were evaluated in 113 patients. Forty-six lymph nodes in 24 cases had malignant axillary involvement. 132 lymph nodes in 89 patients with benign diagnosis were included in the study. The sensitivity of type 3 curve as an indicator of malignancy was calculated as 89%. However the specificity, +LHR, −LHR were calculated as 14%, 1.04, 0.76 respectively. Conclusion: Since kinetic analysis of both benign and malignant axillary lymph nodes, rapid enhancement and washout (type 3) they cannot be used as a discriminator, unlike breast lesions. MRI, depending on the kinetic features of the axillary lymph nodes, is not high enough to be used in the clinical management of breast cancer patients. PMID:25207016

MAC Protocol for Ad Hoc Networks Using a Genetic Algorithm

PubMed Central

Elizarraras, Omar; Panduro, Marco; Méndez, Aldo L.

2014-01-01

The problem of obtaining the transmission rate in an ad hoc network consists in adjusting the power of each node to ensure the signal to interference ratio (SIR) and the energy required to transmit from one node to another is obtained at the same time. Therefore, an optimal transmission rate for each node in a medium access control (MAC) protocol based on CSMA-CDMA (carrier sense multiple access-code division multiple access) for ad hoc networks can be obtained using evolutionary optimization. This work proposes a genetic algorithm for the transmission rate election considering a perfect power control, and our proposition achieves improvement of 10% compared with the scheme that handles the handshaking phase to adjust the transmission rate. Furthermore, this paper proposes a genetic algorithm that solves the problem of power combining, interference, data rate, and energy ensuring the signal to interference ratio in an ad hoc network. The result of the proposed genetic algorithm has a better performance (15%) compared to the CSMA-CDMA protocol without optimizing. Therefore, we show by simulation the effectiveness of the proposed protocol in terms of the throughput. PMID:25140339

Towards a hybrid energy efficient multi-tree-based optimized routing protocol for wireless networks.

PubMed

Mitton, Nathalie; Razafindralambo, Tahiry; Simplot-Ryl, David; Stojmenovic, Ivan

2012-12-13

This paper considers the problem of designing power efficient routing with guaranteed delivery for sensor networks with unknown geographic locations. We propose HECTOR, a hybrid energy efficient tree-based optimized routing protocol, based on two sets of virtual coordinates. One set is based on rooted tree coordinates, and the other is based on hop distances toward several landmarks. In HECTOR, the node currently holding the packet forwards it to its neighbor that optimizes ratio of power cost over distance progress with landmark coordinates, among nodes that reduce landmark coordinates and do not increase distance in tree coordinates. If such a node does not exist, then forwarding is made to the neighbor that reduces tree-based distance only and optimizes power cost over tree distance progress ratio. We theoretically prove the packet delivery and propose an extension based on the use of multiple trees. Our simulations show the superiority of our algorithm over existing alternatives while guaranteeing delivery, and only up to 30% additional power compared to centralized shortest weighted path algorithm.

Towards a Hybrid Energy Efficient Multi-Tree-Based Optimized Routing Protocol for Wireless Networks

PubMed Central

Mitton, Nathalie; Razafindralambo, Tahiry; Simplot-Ryl, David; Stojmenovic, Ivan

2012-01-01

This paper considers the problem of designing power efficient routing with guaranteed delivery for sensor networks with unknown geographic locations. We propose HECTOR, a hybrid energy efficient tree-based optimized routing protocol, based on two sets of virtual coordinates. One set is based on rooted tree coordinates, and the other is based on hop distances toward several landmarks. In HECTOR, the node currently holding the packet forwards it to its neighbor that optimizes ratio of power cost over distance progress with landmark coordinates, among nodes that reduce landmark coordinates and do not increase distance in tree coordinates. If such a node does not exist, then forwarding is made to the neighbor that reduces tree-based distance only and optimizes power cost over tree distance progress ratio. We theoretically prove the packet delivery and propose an extension based on the use of multiple trees. Our simulations show the superiority of our algorithm over existing alternatives while guaranteeing delivery, and only up to 30% additional power compared to centralized shortest weighted path algorithm. PMID:23443398

Cascading failures mechanism based on betweenness-degree ratio distribution with different connecting preferences

NASA Astrophysics Data System (ADS)

Wang, Xiao Juan; Guo, Shi Ze; Jin, Lei; Chen, Mo

We study the structural robustness of the scale free network against the cascading failure induced by overload. In this paper, a failure mechanism based on betweenness-degree ratio distribution is proposed. In the cascading failure model we built the initial load of an edge which is proportional to the node betweenness of its ends. During the edge random deletion, we find a phase transition. Then based on the phase transition, we divide the process of the cascading failure into two parts: the robust area and the vulnerable area, and define the corresponding indicator to measure the performance of the networks in both areas. From derivation, we find that the vulnerability of the network is determined by the distribution of betweenness-degree ratio. After that we use the connection between the node ability coefficient and distribution of betweenness-degree ratio to explain the cascading failure mechanism. In simulations, we verify the correctness of our derivations. By changing connecting preferences, we find scale free networks with a slight assortativity, which performs better both in robust area and vulnerable area.

Self-adaptive trust based ABR protocol for MANETs using Q-learning.

PubMed

Kumar, Anitha Vijaya; Jeyapal, Akilandeswari

2014-01-01

Mobile ad hoc networks (MANETs) are a collection of mobile nodes with a dynamic topology. MANETs work under scalable conditions for many applications and pose different security challenges. Due to the nomadic nature of nodes, detecting misbehaviour is a complex problem. Nodes also share routing information among the neighbours in order to find the route to the destination. This requires nodes to trust each other. Thus we can state that trust is a key concept in secure routing mechanisms. A number of cryptographic protection techniques based on trust have been proposed. Q-learning is a recently used technique, to achieve adaptive trust in MANETs. In comparison to other machine learning computational intelligence techniques, Q-learning achieves optimal results. Our work focuses on computing a score using Q-learning to weigh the trust of a particular node over associativity based routing (ABR) protocol. Thus secure and stable route is calculated as a weighted average of the trust value of the nodes in the route and associativity ticks ensure the stability of the route. Simulation results show that Q-learning based trust ABR protocol improves packet delivery ratio by 27% and reduces the route selection time by 40% over ABR protocol without trust calculation.

Self-Adaptive Trust Based ABR Protocol for MANETs Using Q-Learning

PubMed Central

Jeyapal, Akilandeswari

2014-01-01

Mobile ad hoc networks (MANETs) are a collection of mobile nodes with a dynamic topology. MANETs work under scalable conditions for many applications and pose different security challenges. Due to the nomadic nature of nodes, detecting misbehaviour is a complex problem. Nodes also share routing information among the neighbours in order to find the route to the destination. This requires nodes to trust each other. Thus we can state that trust is a key concept in secure routing mechanisms. A number of cryptographic protection techniques based on trust have been proposed. Q-learning is a recently used technique, to achieve adaptive trust in MANETs. In comparison to other machine learning computational intelligence techniques, Q-learning achieves optimal results. Our work focuses on computing a score using Q-learning to weigh the trust of a particular node over associativity based routing (ABR) protocol. Thus secure and stable route is calculated as a weighted average of the trust value of the nodes in the route and associativity ticks ensure the stability of the route. Simulation results show that Q-learning based trust ABR protocol improves packet delivery ratio by 27% and reduces the route selection time by 40% over ABR protocol without trust calculation. PMID:25254243

Centralized Routing and Scheduling Using Multi-Channel System Single Transceiver in 802.16d

NASA Astrophysics Data System (ADS)

Al-Hemyari, A.; Noordin, N. K.; Ng, Chee Kyun; Ismail, A.; Khatun, S.

This paper proposes a cross-layer optimized strategy that reduces the effect of interferences from neighboring nodes within a mesh networks. This cross-layer design relies on the routing information in network layer and the scheduling table in medium access control (MAC) layer. A proposed routing algorithm in network layer is exploited to find the best route for all subscriber stations (SS). Also, a proposed centralized scheduling algorithm in MAC layer is exploited to assign a time slot for each possible node transmission. The cross-layer optimized strategy is using multi-channel single transceiver and single channel single transceiver systems for WiMAX mesh networks (WMNs). Each node in WMN has a transceiver that can be tuned to any available channel for eliminating the secondary interference. Among the considered parameters in the performance analysis are interference from the neighboring nodes, hop count to the base station (BS), number of children per node, slot reuse, load balancing, quality of services (QoS), and node identifier (ID). Results show that the proposed algorithms significantly improve the system performance in terms of length of scheduling, channel utilization ratio (CUR), system throughput, and average end to end transmission delay.

Diagnostic Value of Endorectal Ultrasound in Preoperative Assessment of Lymph Node Involvement in Colorectal Cancer: a Meta-analysis.

PubMed

Li, Li; Chen, Shi; Wang, Ke; Huang, Jiao; Liu, Li; Wei, Sheng; Gao, Hong-Yu

2015-01-01

Nodal invasion by colorectal cancer is a critical determinant in estimating patient survival and in choosing appropriate preoperative treatment. The present meta-analysis was designed to evaluate the diagnostic value of endorectal ultrasound (EUS) in preoperative assessment of lymph node involvement in colorectal cancer. We systematically searched PubMed, Web of Science, Embase, and China National Knowledge Infrastructure (CNKI) databases for relevant studies published on or before December 10th, 2014. The sensitivity, specificity, likelihood ratios, diagnostic odds ratio (DOR) and area under the summary receiver operating characteristics curve (AUC) were assessed to estimate the diagnostic value of EUS. Subgroup analysis and meta-regression were performed to explore heterogeneity across studies. Thirty-three studies covering 3,016 subjects were included. The pooled sensitivity and specificity were 0.69 (95%CI: 0.63-0.75) and 0.77 (95%CI: 0.73-0.82), respectively. The positive and negative likelihood ratios were 3.09 (95%CI: 2.52-3.78) and 0.39 (95%CI: 0.32-0.48), respectively. The DOR was 7.84 (95%CI: 5.56-11.08), and AUC was 0.80 (95%CI: 0.77-0.84). This meta-analysis indicated that EUS has moderate diagnostic value in preoperative assessment of lymph node involvement in colorectal cancer. Further refinements in technology and diagnostic criteria are necessary to improve the diagnostic accuracy of EUS.

Long non-coding RNA CCAT1 as a diagnostic and prognostic molecular marker in various cancers: a meta-analysis.

PubMed

Zhang, Zhihui; Xie, Haibiao; Liang, Daqiang; Huang, Lanbing; Liang, Feiguo; Qi, Qiang; Yang, Xinjian

2018-05-04

Long non-coding RNA colon cancer-associated transcript-1 (CCAT1) is newly found to be related with diagnoses and prognosis of cancer. This meta-analysis was performed to investigate the relationship between CCAT1 expression and clinical parameters, including survival condition, lymph node metastasis and tumor node metastasis grade. The primary literatures were collected through initial search criteria from electronic databases, including PubMed, OVID Evidence-based medicine Reviews and others (up to May 12, 2017). Eligible studies were identified and selected by the inclusion and exclusion criteria. Data was extracted and computed into Hazard ratio (HR) for the assessment of overall survival, subgroup analyses were prespecified based on the digestive tract cancer or others. Analysis of different CCAT1 expression related with lymph node metastasis or tumor node metastasis grade was conducted. Risk of bias was assessed by the Newcastle-Ottawa Scale. 9 studies were included. This meta-analysis showed that high CCAT1 expression level was related to poor overall survival, the pooled HR was 2.42 (95% confidence interval, CI: 1.86-3.16; P < 0.001; fix- effects model), similarly in the cancer type subgroups: digestive tract cancer (HR, 2.42; 95% CI, 1.79-3.29; P < 0.001; fix- effects model) and others (HR, 2.42; 95% CI, 1.42-4.13; P = 0.001; fix- effects model). The analysis showed that high CCAT1 was strongly related to positive lymph node metastasis (Odds ratio, OR: 3.24; 95% CI, 2.04-5.16; P < 0.001; fix- effects model), high tumor node metastasis stage (OR, 3.87; 95% CI, 2.53-5.92; P < 0.001; fix- effects model). In conclusion, this meta-analysis revealed that CCAT1 had potential as a diagnostic and prognostic biomarker in various cancers.

Optimizing treatment for children and adolescents with papillary thyroid carcinoma in post-Chernobyl exposed region: The roles of lymph node dissections in the central and lateral neck compartments.

PubMed

Fridman, Mikhail; Krasko, Olga; Lam, Alfred King-Yin

2018-06-01

There is lack of data to predict lymph node metastases in pediatric thyroid cancer. The aims are to study (1) the factors affecting the lymph node metastases in children and adolescence with papillary thyroid carcinoma in region exposed to radiation and (2) to evaluate the predictive significance of these factors for lateral compartment lymphadenectomy. Five hundred and nine patients with papillary thyroid carcinoma underwent total thyroidectomy and lymph nodes resection (central and lateral compartments of the neck) surgery during the period of 1991-2010 in Belarus were recruited. The factors related to lymph node metastases were studied in these patients. In the patients with papillary thyroid carcinoma, increase number of cancer-positive lymph nodes in the central neck compartment were associated with a risk to develop lateral nodal disease as well as bilateral nodal disease. Futhermore, positive lateral compartment nodal metastases are associated with age and gender of the patients, tumour size, minimal extra-thyroidal extension, solid architectonic, extensive desmoplasia in carcinoma, presence of psammoma bodies, extensive involvement of the thyroid and metastatic ratio index revealed after examination of the central cervical chain lymph nodes. The presence of nodal disease, degree of lymph node involvement and the distribution of lymph node metastases significantly increase the recurrence rates of patients with papillary thyroid carcinoma. To conclude, the lymph nodes metastases in young patients with papillary thyroid carcinoma in post-Chernobyl exposed region are common and the pattern could be predicted by many clinical and pathological factors. Copyright © 2018 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.

Ultrasound-Guided Fine-Needle Aspiration of Non-palpable and Suspicious Axillary Lymph Nodes with Subsequent Removal after Tattooing: False-Negative Results and Concordance with Sentinel Lymph Nodes.

PubMed

Kim, Won Hwa; Kim, Hye Jung; Jung, Jin Hyang; Park, Ho Yong; Lee, Jeeyeon; Kim, Wan Wook; Park, Ji Young; Cheon, Hyejin; Lee, So Mi; Cho, Seung Hyun; Shin, Kyung Min; Kim, Gab Chul

2017-11-01

Ultrasonography-guided fine-needle aspiration (US-guided FNA) for axillary lymph nodes (ALNs) is currently used with various techniques for the initial staging of breast cancer and tagging of ALNs. With the implementation of the tattooing of biopsied ALNs, the rate of false-negative results of US-guided FNA for non-palpable and suspicious ALNs and concordance with sentinel lymph nodes were determined by node-to node analyses. A total of 61 patients with breast cancer had negative results for metastasis on US-guided FNA of their non-palpable and suspicious ALNs. The biopsied ALNs were tattooed with an injection of 1-3 mL Charcotrace (Phebra, Lane Cove West, Australia) ink and removed during sentinel lymph node biopsy or axillary dissection. We determined the rate of false-negative results and concordance with the sentinel lymph nodes by a retrospective review of surgical and pathologic findings. The association of false-negative results with clinical and imaging factors was evaluated using logistic regression. Of the 61 ALNs with negative results for US-guided FNA, 13 (21%) had metastases on final pathology. In 56 of 61 ALNs (92%), tattooed ALNs corresponded to the sentinel lymph nodes. Among the 5 patients (8%) without correspondence, 1 patient (2%) had 2 metastatic ALNs of 1 tattooed node and 1 sentinel lymph node. In multivariate analysis, atypical cells on FNA results (odds ratio = 20.7, p = 0.040) was independently associated with false-negative FNA results. False-negative ALNs after US-guided FNA occur at a rate of 21% and most of the tattooed ALNs showed concordance with sentinel lymph nodes. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

LoWMob: Intra-PAN Mobility Support Schemes for 6LoWPAN

PubMed Central

Bag, Gargi; Raza, Muhammad Taqi; Kim, Ki-Hyung; Yoo, Seung-Wha

2009-01-01

Mobility in 6LoWPAN (IPv6 over Low Power Personal Area Networks) is being utilized in realizing many applications where sensor nodes, while moving, sense and transmit the gathered data to a monitoring server. By employing IEEE802.15.4 as a baseline for the link layer technology, 6LoWPAN implies low data rate and low power consumption with periodic sleep and wakeups for sensor nodes, without requiring them to incorporate complex hardware. Also enabling sensor nodes with IPv6 ensures that the sensor data can be accessed anytime and anywhere from the world. Several existing mobility-related schemes like HMIPv6, MIPv6, HAWAII, and Cellular IP require active participation of mobile nodes in the mobility signaling, thus leading to the mobility-related changes in the protocol stack of mobile nodes. In this paper, we present LoWMob, which is a network-based mobility scheme for mobile 6LoWPAN nodes in which the mobility of 6LoWPAN nodes is handled at the network-side. LoWMob ensures multi-hop communication between gateways and mobile nodes with the help of the static nodes within a 6LoWPAN. In order to reduce the signaling overhead of static nodes for supporting mobile nodes, LoWMob proposes a mobility support packet format at the adaptation layer of 6LoWPAN. Also we present a distributed version of LoWMob, named as DLoWMob (or Distributed LoWMob), which employs Mobility Support Points (MSPs) to distribute the traffic concentration at the gateways and to optimize the multi-hop routing path between source and destination nodes in a 6LoWPAN. Moreover, we have also discussed the security considerations for our proposed mobility schemes. The performance of our proposed schemes is evaluated in terms of mobility signaling costs, end-to-end delay, and packet success ratio. PMID:22346730

LoWMob: Intra-PAN Mobility Support Schemes for 6LoWPAN.

PubMed

Bag, Gargi; Raza, Muhammad Taqi; Kim, Ki-Hyung; Yoo, Seung-Wha

2009-01-01

Mobility in 6LoWPAN (IPv6 over Low Power Personal Area Networks) is being utilized in realizing many applications where sensor nodes, while moving, sense and transmit the gathered data to a monitoring server. By employing IEEE802.15.4 as a baseline for the link layer technology, 6LoWPAN implies low data rate and low power consumption with periodic sleep and wakeups for sensor nodes, without requiring them to incorporate complex hardware. Also enabling sensor nodes with IPv6 ensures that the sensor data can be accessed anytime and anywhere from the world. Several existing mobility-related schemes like HMIPv6, MIPv6, HAWAII, and Cellular IP require active participation of mobile nodes in the mobility signaling, thus leading to the mobility-related changes in the protocol stack of mobile nodes. In this paper, we present LoWMob, which is a network-based mobility scheme for mobile 6LoWPAN nodes in which the mobility of 6LoWPAN nodes is handled at the network-side. LoWMob ensures multi-hop communication between gateways and mobile nodes with the help of the static nodes within a 6LoWPAN. In order to reduce the signaling overhead of static nodes for supporting mobile nodes, LoWMob proposes a mobility support packet format at the adaptation layer of 6LoWPAN. Also we present a distributed version of LoWMob, named as DLoWMob (or Distributed LoWMob), which employs Mobility Support Points (MSPs) to distribute the traffic concentration at the gateways and to optimize the multi-hop routing path between source and destination nodes in a 6LoWPAN. Moreover, we have also discussed the security considerations for our proposed mobility schemes. The performance of our proposed schemes is evaluated in terms of mobility signaling costs, end-to-end delay, and packet success ratio.

Synchronous Firefly Algorithm for Cluster Head Selection in WSN.

PubMed

Baskaran, Madhusudhanan; Sadagopan, Chitra

2015-01-01

Wireless Sensor Network (WSN) consists of small low-cost, low-power multifunctional nodes interconnected to efficiently aggregate and transmit data to sink. Cluster-based approaches use some nodes as Cluster Heads (CHs) and organize WSNs efficiently for aggregation of data and energy saving. A CH conveys information gathered by cluster nodes and aggregates/compresses data before transmitting it to a sink. However, this additional responsibility of the node results in a higher energy drain leading to uneven network degradation. Low Energy Adaptive Clustering Hierarchy (LEACH) offsets this by probabilistically rotating cluster heads role among nodes with energy above a set threshold. CH selection in WSN is NP-Hard as optimal data aggregation with efficient energy savings cannot be solved in polynomial time. In this work, a modified firefly heuristic, synchronous firefly algorithm, is proposed to improve the network performance. Extensive simulation shows the proposed technique to perform well compared to LEACH and energy-efficient hierarchical clustering. Simulations show the effectiveness of the proposed method in decreasing the packet loss ratio by an average of 9.63% and improving the energy efficiency of the network when compared to LEACH and EEHC.

Differences in treatment and survival among African-American and Caucasian women with early stage operable breast cancer.

PubMed

Sail, Kavita; Franzini, Luisa; Lairson, David; Du, Xianglin

2012-01-01

To examine racial disparities associated with breast cancer treatment and survival in elderly patients with early stage operable breast cancer. We studied 23,110 women with node-positive and 31,572 women with node-negative tumor who were aged ≥65 with stages I, II, or IIIA breast cancer in 1991-2002 using the Surveillance, Epidemiology and End Results (SEER)-Medicare linked data. Logistic regression analyses were performed to assess the odds of receiving adjuvant chemotherapy and radiation after breast conserving surgery (BCS) for blacks compared to whites. Cox proportional hazard regression models were used to determine the risk of mortality in blacks compared to whites, stratified by types of treatment. Black women with node-positive and node-negative tumors were 25% (odds ratio = 0.75, 95% CI = 0.65-0.87) and 17% (0.83, 0.70-0.99) less likely to receive chemotherapy than white women, after adjusting for patient and tumor characteristics. This relation was not attenuated and remained statistically significant even after adjustment for socioeconomic status. In women with node-negative tumor who did not receive chemotherapy, black women were significantly more likely to die than white women (hazard ratio (HR) = 1.14, 95% CI = 1.04-1.24) after adjusting for patient and tumor characteristics, and comorbidity; and (1.11, 1.01-1.22) after additionally adjusting for socioeconomic status. There were racial disparities between black and white women in receiving adjuvant chemotherapy and radiotherapy following BCS. Higher risk of mortality in black compared to white women was found only in those receiving no chemotherapy. Future studies should explore the root causes of racial disparities beyond treatment factors.

A privacy-preserving parallel and homomorphic encryption scheme

NASA Astrophysics Data System (ADS)

Min, Zhaoe; Yang, Geng; Shi, Jingqi

2017-04-01

In order to protect data privacy whilst allowing efficient access to data in multi-nodes cloud environments, a parallel homomorphic encryption (PHE) scheme is proposed based on the additive homomorphism of the Paillier encryption algorithm. In this paper we propose a PHE algorithm, in which plaintext is divided into several blocks and blocks are encrypted with a parallel mode. Experiment results demonstrate that the encryption algorithm can reach a speed-up ratio at about 7.1 in the MapReduce environment with 16 cores and 4 nodes.

Distributed Optimization of Multi Beam Directional Communication Networks

DTIC Science & Technology

2017-06-30

kT is the noise figure of the receiver. The path loss from node i to the central station is denoted as fi,C and is similarly defined. We seek to...optimally allocate power among several transmit beams per node in order to maximize the total signal-to- interference noise ratio at the central station...Computing, vol. 15, no. 9, September 2016. [6] X. Quan, Y. Liu, S. Shao, C. Huang, and Y. Tang, “Impacts of Phase Noise on Digital Self-Iinterference

Variable-range-hopping magnetoresistance

NASA Astrophysics Data System (ADS)

Azbel, Mark Ya

1991-03-01

The hopping magnetoresistance R of a two-dimensional insulator with metallic impurities is considered. In sufficiently weak magnetic fields it increases or decreases depending on the impurity density n: It decreases if n is low and increases if n is high. In high magnetic fields B, it always exponentially increases with √B . Such fields yield a one-dimensional temperature dependence: lnR~1/ √T . The calculation provides an accurate leading approximation for small impurities with one eigenstate in their potential well. In the limit of infinitesimally small impurities, an impurity potential is described by a generalized function. This function, similar to a δ function, is localized at a point, but, contrary to a δ function in the dimensionality above 1, it has finite eigenenergies. Such functions may be helpful in the study of scattering and localization of any waves.

Reconfigurable routing protocol for free space optical sensor networks.

PubMed

Xie, Rong; Yang, Won-Hyuk; Kim, Young-Chon

2012-01-01

Recently, free space optical sensor networks (FSOSNs), which are based on free space optics (FSO) instead of radio frequency (RF), have gained increasing visibility over traditional wireless sensor networks (WSNs) due to their advantages such as larger capacity, higher security, and lower cost. However, the performance of FSOSNs is restricted to the requirement of a direct line-of-sight (LOS) path between a sender and a receiver pair. Once a node dies of energy depletion, the network would probably suffer from a dramatic decrease of connectivity, resulting in a huge loss of data packets. Thus, this paper proposes a reconfigurable routing protocol (RRP) to overcome this problem by dynamically reconfiguring the network virtual topology. The RRP works in three phases: (1) virtual topology construction, (2) routing establishment, and (3) reconfigurable routing. When data transmission begins, the data packets are first routed through the shortest hop paths. Then a reconfiguration is initiated by the node whose residual energy falls below a threshold. Nodes affected by this dying node are classified into two types, namely maintenance nodes and adjustment nodes, and they are reconfigured according to the types. An energy model is designed to evaluate the performance of RRP through OPNET simulation. Our simulation results indicate that the RRP achieves better performance compared with the simple-link protocol and a direct reconfiguration scheme in terms of connectivity, network lifetime, packet delivery ratio and the number of living nodes.

One node driving synchronisation

NASA Astrophysics Data System (ADS)

Wang, Chengwei; Grebogi, Celso; Baptista, Murilo S.

2015-12-01

Abrupt changes of behaviour in complex networks can be triggered by a single node. This work describes the dynamical fundamentals of how the behaviour of one node affects the whole network formed by coupled phase-oscillators with heterogeneous coupling strengths. The synchronisation of phase-oscillators is independent of the distribution of the natural frequencies, weakly depends on the network size, but highly depends on only one key oscillator whose ratio between its natural frequency in a rotating frame and its coupling strength is maximum. This result is based on a novel method to calculate the critical coupling strength with which the phase-oscillators emerge into frequency synchronisation. In addition, we put forward an analytical method to approximately calculate the phase-angles for the synchronous oscillators.

One node driving synchronisation

PubMed Central

Wang, Chengwei; Grebogi, Celso; Baptista, Murilo S.

2015-01-01

Abrupt changes of behaviour in complex networks can be triggered by a single node. This work describes the dynamical fundamentals of how the behaviour of one node affects the whole network formed by coupled phase-oscillators with heterogeneous coupling strengths. The synchronisation of phase-oscillators is independent of the distribution of the natural frequencies, weakly depends on the network size, but highly depends on only one key oscillator whose ratio between its natural frequency in a rotating frame and its coupling strength is maximum. This result is based on a novel method to calculate the critical coupling strength with which the phase-oscillators emerge into frequency synchronisation. In addition, we put forward an analytical method to approximately calculate the phase-angles for the synchronous oscillators. PMID:26656718

Load balancing strategy and its lookup-table enhancement in deterministic space delay/disruption tolerant networks

NASA Astrophysics Data System (ADS)

Huang, Jinhui; Liu, Wenxiang; Su, Yingxue; Wang, Feixue

2018-02-01

Space networks, in which connectivity is deterministic and intermittent, can be modeled by delay/disruption tolerant networks. In space delay/disruption tolerant networks, a packet is usually transmitted from the source node to the destination node indirectly via a series of relay nodes. If anyone of the nodes in the path becomes congested, the packet will be dropped due to buffer overflow. One of the main reasons behind congestion is the unbalanced network traffic distribution. We propose a load balancing strategy which takes the congestion status of both the local node and relay nodes into account. The congestion status, together with the end-to-end delay, is used in the routing selection. A lookup-table enhancement is also proposed. The off-line computation and the on-line adjustment are combined together to make a more precise estimate of the end-to-end delay while at the same time reducing the onboard computation. Simulation results show that the proposed strategy helps to distribute network traffic more evenly and therefore reduces the packet drop ratio. In addition, the average delay is also decreased in most cases. The lookup-table enhancement provides a compromise between the need for better communication performance and the desire for less onboard computation.

Node similarity within subgraphs of protein interaction networks

NASA Astrophysics Data System (ADS)

Penner, Orion; Sood, Vishal; Musso, Gabriel; Baskerville, Kim; Grassberger, Peter; Paczuski, Maya

2008-06-01

We propose a biologically motivated quantity, twinness, to evaluate local similarity between nodes in a network. The twinness of a pair of nodes is the number of connected, labeled subgraphs of size n in which the two nodes possess identical neighbours. The graph animal algorithm is used to estimate twinness for each pair of nodes (for subgraph sizes n=4 to n=12) in four different protein interaction networks (PINs). These include an Escherichia coli PIN and three Saccharomyces cerevisiae PINs - each obtained using state-of-the-art high-throughput methods. In almost all cases, the average twinness of node pairs is vastly higher than that expected from a null model obtained by switching links. For all n, we observe a difference in the ratio of type A twins (which are unlinked pairs) to type B twins (which are linked pairs) distinguishing the prokaryote E. coli from the eukaryote S. cerevisiae. Interaction similarity is expected due to gene duplication, and whole genome duplication paralogues in S. cerevisiae have been reported to co-cluster into the same complexes. Indeed, we find that these paralogous proteins are over-represented as twins compared to pairs chosen at random. These results indicate that twinness can detect ancestral relationships from currently available PIN data.

Data Acquisition Based on Stable Matching of Bipartite Graph in Cooperative Vehicle–Infrastructure Systems †

PubMed Central

Tang, Xiaolan; Hong, Donghui; Chen, Wenlong

2017-01-01

Existing studies on data acquisition in vehicular networks often take the mobile vehicular nodes as data carriers. However, their autonomous movements, limited resources and security risks impact the quality of services. In this article, we propose a data acquisition model using stable matching of bipartite graph in cooperative vehicle-infrastructure systems, namely, DAS. Contents are distributed to roadside units, while vehicular nodes support supplementary storage. The original distribution problem is formulated as a stable matching problem of bipartite graph, where the data and the storage cells compose two sides of vertices. Regarding the factors relevant with the access ratio and delay, the preference rankings for contents and roadside units are calculated, respectively. With a multi-replica preprocessing algorithm to handle the potential one-to-many mapping, the matching problem is addressed in polynomial time. In addition, vehicular nodes carry and forward assistant contents to deliver the failed packets because of bandwidth competition. Furthermore, an incentive strategy is put forward to boost the vehicle cooperation and to achieve a fair bandwidth allocation at roadside units. Experiments show that DAS achieves a high access ratio and a small storage cost with an acceptable delay. PMID:28594359

Digital seismo-acoustic signal processing aboard a wireless sensor platform

NASA Astrophysics Data System (ADS)

Marcillo, O.; Johnson, J. B.; Lorincz, K.; Werner-Allen, G.; Welsh, M.

2006-12-01

We are developing a low power, low-cost wireless sensor array to conduct real-time signal processing of earthquakes at active volcanoes. The sensor array, which integrates data from both seismic and acoustic sensors, is based on Moteiv TMote Sky wireless sensor nodes (www.moteiv.com). The nodes feature a Texas Instruments MSP430 microcontroller, 48 Kbytes of program memory, 10 Kbytes of static RAM, 1 Mbyte of external flash memory, and a 2.4-GHz Chipcon CC2420 IEEE 802.15.4 radio. The TMote Sky is programmed in TinyOS. Basic signal processing occurs on an array of three peripheral sensor nodes. These nodes are tied into a dedicated GPS receiver node, which is focused on time synchronization, and a central communications node, which handles data integration and additional processing. The sensor nodes incorporate dual 12-bit digitizers sampling a seismic sensor and a pressure transducer at 100 samples per second. The wireless capabilities of the system allow flexible array geometry, with a maximum aperture of 200m. We have already developed the digital signal processing routines on board the Moteiv Tmote sensor nodes. The developed routines accomplish Real-time Seismic-Amplitude Measurement (RSAM), Seismic Spectral- Amplitude Measurement (SSAM), and a user-configured Short Term Averaging / Long Term Averaging (STA LTA ratio), which is used to calculate first arrivals. The processed data from individual nodes are transmitted back to a central node, where additional processing may be performed. Such processing will include back azimuth determination and other wave field analyses. Future on-board signal processing will focus on event characterization utilizing pattern recognition and spectral characterization. The processed data is intended as low bandwidth information which can be transmitted periodically and at low cost through satellite telemetry to a web server. The processing is limited by the computational capabilities (RAM, ROM) of the nodes. Nevertheless, we envision this product to be a useful tool for assessing the state of unrest at remote volcanoes.

Enhancing the Accuracy of Platelet to Lymphocyte Ratio after Adjustment for Large Platelet Count: A Pilot Study in Breast Cancer Patients

PubMed Central

Seretis, Charalampos; Seretis, Fotios; Lagoudianakis, Emmanuel; Politou, Marianna; Gemenetzis, George; Salemis, Nikolaos S.

2012-01-01

Background. The objective of our study is to investigate the potential effect of adjusting preoperative platelet to lymphocyte ratio, an emerging biomarker of survival in cancer patients, for the fraction of large platelets. Methods. A total of 79 patients with breast neoplasias, 44 with fibroadenomas, and 35 with invasive ductal carcinoma were included in the study. Both conventional platelet to lymphocyte ratio (PLR) and the adjusted marker, large platelet to lymphocyte ratio (LPLR), were correlated with laboratory and histopathological parameters of the study sample. Results. LPLR elevation was significantly correlated with the presence of malignancy, advanced tumor stage, metastatic spread in the axillary nodes and HER2/neu overexpression, while PLR was only correlated with the number of infiltrated lymph nodes. Conclusions. This is the first study evaluating the effect of adjustment for large platelet count on improving PLR accuracy, when correlated with the basic independent markers of survival in a sample of breast cancer patients. Further studies are needed in order to assess the possibility of applying our adjustment as standard in terms of predicting survival rates in cancer. PMID:23304480

Enhancing the accuracy of platelet to lymphocyte ratio after adjustment for large platelet count: a pilot study in breast cancer patients.

PubMed

Seretis, Charalampos; Seretis, Fotios; Lagoudianakis, Emmanuel; Politou, Marianna; Gemenetzis, George; Salemis, Nikolaos S

2012-01-01

Background. The objective of our study is to investigate the potential effect of adjusting preoperative platelet to lymphocyte ratio, an emerging biomarker of survival in cancer patients, for the fraction of large platelets. Methods. A total of 79 patients with breast neoplasias, 44 with fibroadenomas, and 35 with invasive ductal carcinoma were included in the study. Both conventional platelet to lymphocyte ratio (PLR) and the adjusted marker, large platelet to lymphocyte ratio (LPLR), were correlated with laboratory and histopathological parameters of the study sample. Results. LPLR elevation was significantly correlated with the presence of malignancy, advanced tumor stage, metastatic spread in the axillary nodes and HER2/neu overexpression, while PLR was only correlated with the number of infiltrated lymph nodes. Conclusions. This is the first study evaluating the effect of adjustment for large platelet count on improving PLR accuracy, when correlated with the basic independent markers of survival in a sample of breast cancer patients. Further studies are needed in order to assess the possibility of applying our adjustment as standard in terms of predicting survival rates in cancer.

Differences in fluorescence profiles from breast cancer tissues due to changes in relative tryptophan content via energy transfer: tryptophan content correlates with histologic grade and tumor size but not with lymph node metastases

NASA Astrophysics Data System (ADS)

Sordillo, Laura A.; Sordillo, Peter P.; Budansky, Yury; Pu, Yang; Alfano, Robert R.

2014-12-01

The correlation between histologic grade, an increasingly important measure of prognosis for patients with breast cancer, and tryptophan levels from tissues of 15 breast carcinoma patients was investigated. Changes in the relative content of key native organic biomolecule tryptophan were seen from the fluorescence spectra of cancerous and paired normal tissues with excitation wavelengths of 280 and 300 nm. Due to a large spectral overlap and matching excitation-emission spectra, fluorescence resonance energy transfer from tryptophan-donor to reduced nicotinamide adenine dinucleotides-acceptor was noted. We used the ratios of fluorescence intensities at their spectral emission peaks, or spectral fingerprint peaks, at 340, 440, and 460 nm. Higher ratios correlated strongly with high histologic grade, while lower-grade tumors had low ratios. Large tumor size also correlated with high ratios, while the number of lymph node metastases, a major factor in staging, was not correlated with tryptophan levels. High histologic grade correlates strongly with increased content of tryptophan in breast cancer tissues and suggests that measurement of tryptophan content may be useful as a part of the evaluation of these patients.

The Value of Sentinel Lymph Node Biopsy in Oral Cavity Cancers

PubMed Central

Kaya, İsa; Göde, Sercan; Öztürk, Kerem; Turhal, Göksel; Aliyev, Araz; Akyıldız, Serdar; Duygun, Ülkem Yararbaş; Uluöz, Ümit; Yavuzer, Atilla

2015-01-01

Objective The aim of this study was to establish the effectiveness of sentinel lymph node biopsy in the detection of metastasis in N0 necks of T1–T2 early-stage oral cavity cancers. Materials and Methods Twenty neck dissections were performed in 18 patients diagnosed with T1 and T2 oral cavity cancer, with an indication for elective neck dissection between November 2007 and January 2011. The male to female ratio was 12:8, with a mean age of 54.5 years (range 28–76). Eight of the dissections were performed for lower lip cancer, 7 for tongue cancer, and 5 for floor of the mouth cancer. Sentinel lymph node biopsy was used to detect metastatic lymph nodes. Tc99m radionuclide injection was administered to the periphery of the tumor 24 h before the operation, and a lymphoscintigraphy image was obtained 30 min after the injection. Sentinel lymph nodes were localized and excised on the day of surgery using static lymphoscintigraphy images and a gamma probe. Sentinel lymph nodes were sent for a frozen section examination, and either a selective or a comprehensive neck dissection was performed for each neck according to the results. Results After the final histopathological examination of the specimens, the negative predictive value, the positive predictive value, the accuracy of the sentinel lymph node biopsy, and frozen section accuracy were found to be 100%. Conclusion Sentinel lymph node biopsy was found to be an efficient method in the pathological staging and management of the N0 neck in early T-stage oral cavity cancers. PMID:29391982

DMP: Detouring Using Multiple Paths against Jamming Attack for Ubiquitous Networking System

PubMed Central

Kim, Mihui; Chae, Kijoon

2010-01-01

To successfully realize the ubiquitous network environment including home automation or industrial control systems, it is important to be able to resist a jamming attack. This has recently been considered as an extremely threatening attack because it can collapse the entire network, despite the existence of basic security protocols such as encryption and authentication. In this paper, we present a method of jamming attack tolerant routing using multiple paths based on zones. The proposed scheme divides the network into zones, and manages the candidate forward nodes of neighbor zones. After detecting an attack, detour nodes decide zones for rerouting, and detour packets destined for victim nodes through forward nodes in the decided zones. Simulation results show that our scheme increases the PDR (Packet Delivery Ratio) and decreases the delay significantly in comparison with rerouting by a general routing protocol on sensor networks, AODV (Ad hoc On Demand Distance Vector), and a conventional JAM (Jammed Area Mapping) service with one reroute. PMID:22319316

B-mode sonographic criteria for differential diagnosis of cervicofacial lymphadenopathy in cat-scratch disease and toxoplasmosis.

PubMed

Ridder, Gerd Jürgen; Boedeker, Carsten Christof; Lee, Tao-Kwang Kevin; Sander, Anna

2003-04-01

Our purpose was to evaluate different sonographic parameters of cervicofacial lymphadenopathy caused by cat-scratch disease (CSD) and toxoplasmosis. By use of high-resolution B-mode sonography a total of 552 lymph nodes in the head and neck were detected between January 1997 and December 2001. There were 71 patients (422 lymph nodes) with CSD and 19 patients (130 lymph nodes) with toxoplasmosis. Sonographic variables, including 20 sonomorphologic features along with age and gender, were analyzed with multivariate logistic regression. Heterogenous lymph nodes were more often found in CSD (p =.003), and nonsharp nodal borders showed a significant association with CSD (p =.0005). Multivariate analysis identified sharpness of borders (p =.0001), S/L ratio (p =.0006), and type of lymphadenopathy (acute, abscessed, chronic) (p =.0006) as most significant for differentiating between CSD and toxoplasmosis. These results provide significant and useful criteria for ultrasonographic differentiation between CSD and toxoplasmosis. Copyright 2003 Wiley Periodicals, Inc.

Region-Based Collision Avoidance Beaconless Geographic Routing Protocol in Wireless Sensor Networks.

PubMed

Lee, JeongCheol; Park, HoSung; Kang, SeokYoon; Kim, Ki-Il

2015-06-05

Due to the lack of dependency on beacon messages for location exchange, the beaconless geographic routing protocol has attracted considerable attention from the research community. However, existing beaconless geographic routing protocols are likely to generate duplicated data packets when multiple winners in the greedy area are selected. Furthermore, these protocols are designed for a uniform sensor field, so they cannot be directly applied to practical irregular sensor fields with partial voids. To prevent the failure of finding a forwarding node and to remove unnecessary duplication, in this paper, we propose a region-based collision avoidance beaconless geographic routing protocol to increase forwarding opportunities for randomly-deployed sensor networks. By employing different contention priorities into the mutually-communicable nodes and the rest of the nodes in the greedy area, every neighbor node in the greedy area can be used for data forwarding without any packet duplication. Moreover, simulation results are given to demonstrate the increased packet delivery ratio and shorten end-to-end delay, rather than well-referred comparative protocols.

A Multi-Agent Framework for Packet Routing in Wireless Sensor Networks

PubMed Central

Ye, Dayon; Zhang, Minji; Yang, Yu

2015-01-01

Wireless sensor networks (WSNs) have been widely investigated in recent years. One of the fundamental issues in WSNs is packet routing, because in many application domains, packets have to be routed from source nodes to destination nodes as soon and as energy efficiently as possible. To address this issue, a large number of routing approaches have been proposed. Although every existing routing approach has advantages, they also have some disadvantages. In this paper, a multi-agent framework is proposed that can assist existing routing approaches to improve their routing performance. This framework enables each sensor node to build a cooperative neighbour set based on past routing experience. Such cooperative neighbours, in turn, can help the sensor to effectively relay packets in the future. This framework is independent of existing routing approaches and can be used to assist many existing routing approaches. Simulation results demonstrate the good performance of this framework in terms of four metrics: average delivery latency, successful delivery ratio, number of live nodes and total sensing coverage. PMID:25928063

Region-Based Collision Avoidance Beaconless Geographic Routing Protocol in Wireless Sensor Networks

PubMed Central

Lee, JeongCheol; Park, HoSung; Kang, SeokYoon; Kim, Ki-Il

2015-01-01

Due to the lack of dependency on beacon messages for location exchange, the beaconless geographic routing protocol has attracted considerable attention from the research community. However, existing beaconless geographic routing protocols are likely to generate duplicated data packets when multiple winners in the greedy area are selected. Furthermore, these protocols are designed for a uniform sensor field, so they cannot be directly applied to practical irregular sensor fields with partial voids. To prevent the failure of finding a forwarding node and to remove unnecessary duplication, in this paper, we propose a region-based collision avoidance beaconless geographic routing protocol to increase forwarding opportunities for randomly-deployed sensor networks. By employing different contention priorities into the mutually-communicable nodes and the rest of the nodes in the greedy area, every neighbor node in the greedy area can be used for data forwarding without any packet duplication. Moreover, simulation results are given to demonstrate the increased packet delivery ratio and shorten end-to-end delay, rather than well-referred comparative protocols. PMID:26057037

DMP: detouring using multiple paths against jamming attack for ubiquitous networking system.

PubMed

Kim, Mihui; Chae, Kijoon

2010-01-01

To successfully realize the ubiquitous network environment including home automation or industrial control systems, it is important to be able to resist a jamming attack. This has recently been considered as an extremely threatening attack because it can collapse the entire network, despite the existence of basic security protocols such as encryption and authentication. In this paper, we present a method of jamming attack tolerant routing using multiple paths based on zones. The proposed scheme divides the network into zones, and manages the candidate forward nodes of neighbor zones. After detecting an attack, detour nodes decide zones for rerouting, and detour packets destined for victim nodes through forward nodes in the decided zones. Simulation results show that our scheme increases the PDR (Packet Delivery Ratio) and decreases the delay significantly in comparison with rerouting by a general routing protocol on sensor networks, AODV (Ad hoc On Demand Distance Vector), and a conventional JAM (Jammed Area Mapping) service with one reroute.

Joint Resource Optimization for Cognitive Sensor Networks with SWIPT-Enabled Relay.

PubMed

Lu, Weidang; Lin, Yuanrong; Peng, Hong; Nan, Tian; Liu, Xin

2017-09-13

Energy-constrained wireless networks, such as wireless sensor networks (WSNs), are usually powered by fixed energy supplies (e.g., batteries), which limits the operation time of networks. Simultaneous wireless information and power transfer (SWIPT) is a promising technique to prolong the lifetime of energy-constrained wireless networks. This paper investigates the performance of an underlay cognitive sensor network (CSN) with SWIPT-enabled relay node. In the CSN, the amplify-and-forward (AF) relay sensor node harvests energy from the ambient radio-frequency (RF) signals using power splitting-based relaying (PSR) protocol. Then, it helps forward the signal of source sensor node (SSN) to the destination sensor node (DSN) by using the harvested energy. We study the joint resource optimization including the transmit power and power splitting ratio to maximize CSN's achievable rate with the constraint that the interference caused by the CSN to the primary users (PUs) is within the permissible threshold. Simulation results show that the performance of our proposed joint resource optimization can be significantly improved.

Social-aware data dissemination in opportunistic mobile social networks

NASA Astrophysics Data System (ADS)

Yang, Yibo; Zhao, Honglin; Ma, Jinlong; Han, Xiaowei

Opportunistic Mobile Social Networks (OMSNs), formed by mobile users with social relationships and characteristics, enhance spontaneous communication among users that opportunistically encounter each other. Such networks can be exploited to improve the performance of data forwarding. Discovering optimal relay nodes is one of the important issues for efficient data propagation in OMSNs. Although traditional centrality definitions to identify the nodes features in network, they cannot identify effectively the influential nodes for data dissemination in OMSNs. Existing protocols take advantage of spatial contact frequency and social characteristics to enhance transmission performance. However, existing protocols have not fully exploited the benefits of the relations and the effects between geographical information, social features and user interests. In this paper, we first evaluate these three characteristics of users and design a routing protocol called Geo-Social-Interest (GSI) protocol to select optimal relay nodes. We compare the performance of GSI using real INFOCOM06 data sets. The experiment results demonstrate that GSI overperforms the other protocols with highest data delivery ratio and low communication overhead.

Expression and prognostic value of soluble CD97 and its ligand CD55 in intrahepatic cholangiocarcinoma.

PubMed

Meng, Ze-Wu; Liu, Min-Chao; Hong, Hai-Jie; Du, Qiang; Chen, Yan-Ling

2017-03-01

The incidence rate of intrahepatic cholangiocarcinoma is rising, and treatment options are limited. Therefore, new biological markers of intrahepatic cholangiocarcinoma are needed. Immunohistochemistry and enzyme-linked immunosorbent assay were applied to analyze the expressions of CD97, CD55, and soluble CD97 in 71 patients with intrahepatic cholangiocarcinoma and 10 patients with hepatolithiasis. CD97 and CD55 were not expressed in hepatolithiatic tissues, but positive expression was observed in 76.1% (54/71) and 70.4% (50/71) of intrahepatic cholangiocarcinoma patients. The univariate analyses indicated that the positive expressions of CD97 and CD55 were related to short intrahepatic cholangiocarcinoma survival of patients (both p = 0.001). Furthermore, CD97 and CD55 expressions and biliary soluble CD97 levels were significantly associated with histological grade (p = 0.004, 0.002, and 0.012, respectively), lymph node metastases (p = 0.020, 0.038, and 0.001, respectively), and venous invasion (p = 0.003, 0.002, and 0.001, respectively). The multivariate analyses indicated that lymph node metastases (hazard ratio: 2.407, p = 0.003), positive CD55 expression (hazard ratio: 4.096, p = 0.003), and biliary soluble CD97 levels (hazard ratio: 2.434, p = 0.002) were independent risk factors for the intrahepatic cholangiocarcinoma survival. The receiver operating characteristic (ROC) curve analysis indicated that when the cutoff values of biliary soluble CD97 were 1.15 U/mL, the diagnostic value for predicting lymph node metastasis had a sensitivity of 87.5% and a specificity of 51.3%. For intrahepatic cholangiocarcinoma patient death within 60 months at a cutoff value of 0.940 U/mL, the diagnostic value sensitivity was 89.3% and the specificity was 93.3%. Biliary soluble CD97 may be a new biological marker for early diagnosis, prediction of lymph node metastasis and poor prognosis, and discovery of a therapeutic target.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dinshaw, Ketayun A.; Budrukkar, Ashwini N.; Chinoy, Roshan F.

Purpose: The outcome of breast cancer treatment can vary in different geographic and ethnic groups. A multivariate analysis was performed for various prognostic factors in 1022 Indian women with pathologic Stage I-II breast cancer treated between 1980 and 2000 with standard breast-conserving therapy with or without systemic adjuvant therapy. Methods and Materials: At a mean follow-up of 53 months, the outcomes studied were local failure, locoregional failure, and distant failure, overall survival (OS), and disease-free survival (DFS). Results: The median pathologic tumor size was 3 cm (range, 1-5 cm), and axillary lymph node metastasis was present in 39% of women.more » The actuarial 5- and 10-year OS and DFS rate was 87% and 77% and 76% and 68%, respectively. Lymphovascular emboli or invasion (LVI) was the strongest independent adverse factor for all failure and survival (local failure, hazard ratio 2.85; 95% confidence interval, 1.68-4.83; OS; hazard ratio, 2.01, 95% confidence interval, 1.35-2.99). Lymph node metastasis was also an independent adverse factor for local failure, locoregional failure, distant failure, DFS, and OS (hazard ratio, 1.55, 95% confidence interval, 1.04-2.30). Age {<=}40 years increased the incidence of local recurrence, and patients with inner quadrant tumors had inferior DFS. The incidence of LVI was significantly greater in women with lymph node metastases than in node-negative women (p < 0.001) and in women with Grade 3 tumors than in those with Grade 1 or 2 tumors (p = 0.001). Conclusion: In Indian women, LVI was the strongest independent prognostic factor for OS, DFS, and local recurrence, irrespective of nodal status and systemic adjuvant treatment. Although LVI may not be a contraindication for BCT, as has been proposed by certain groups, it is necessary to define its role in prospective studies in determining local and systemic treatment.« less

Molecular organization of cytokinesis nodes and contractile rings by super-resolution fluorescence microscopy of live fission yeast

PubMed Central

Laplante, Caroline; Huang, Fang; Tebbs, Irene R.; Bewersdorf, Joerg; Pollard, Thomas D.

2016-01-01

Cytokinesis in animals, fungi, and amoebas depends on the constriction of a contractile ring built from a common set of conserved proteins. Many fundamental questions remain about how these proteins organize to generate the necessary tension for cytokinesis. Using quantitative high-speed fluorescence photoactivation localization microscopy (FPALM), we probed this question in live fission yeast cells at unprecedented resolution. We show that nodes, protein assembly precursors to the contractile ring, are discrete structural units with stoichiometric ratios and distinct distributions of constituent proteins. Anillin Mid1p, Fes/CIP4 homology-Bin/amphiphysin/Rvs (F-BAR) Cdc15p, IQ motif containing GTPase-activating protein (IQGAP) Rng2p, and formin Cdc12p form the base of the node that anchors the ends of myosin II tails to the plasma membrane, with myosin II heads extending into the cytoplasm. This general node organization persists in the contractile ring where nodes move bidirectionally during constriction. We observed the dynamics of the actin network during cytokinesis, starting with the extension of short actin strands from nodes, which sometimes connected neighboring nodes. Later in cytokinesis, a broad network of thick bundles coalesced into a tight ring around the equator of the cell. The actin ring was ∼125 nm wide and ∼125 nm thick. These observations establish the organization of the proteins in the functional units of a cytokinetic contractile ring. PMID:27647921

A Two-Phase Time Synchronization-Free Localization Algorithm for Underwater Sensor Networks.

PubMed

Luo, Junhai; Fan, Liying

2017-03-30

Underwater Sensor Networks (UWSNs) can enable a broad range of applications such as resource monitoring, disaster prevention, and navigation-assistance. Sensor nodes location in UWSNs is an especially relevant topic. Global Positioning System (GPS) information is not suitable for use in UWSNs because of the underwater propagation problems. Hence, some localization algorithms based on the precise time synchronization between sensor nodes that have been proposed for UWSNs are not feasible. In this paper, we propose a localization algorithm called Two-Phase Time Synchronization-Free Localization Algorithm (TP-TSFLA). TP-TSFLA contains two phases, namely, range-based estimation phase and range-free evaluation phase. In the first phase, we address a time synchronization-free localization scheme based on the Particle Swarm Optimization (PSO) algorithm to obtain the coordinates of the unknown sensor nodes. In the second phase, we propose a Circle-based Range-Free Localization Algorithm (CRFLA) to locate the unlocalized sensor nodes which cannot obtain the location information through the first phase. In the second phase, sensor nodes which are localized in the first phase act as the new anchor nodes to help realize localization. Hence, in this algorithm, we use a small number of mobile beacons to help obtain the location information without any other anchor nodes. Besides, to improve the precision of the range-free method, an extension of CRFLA achieved by designing a coordinate adjustment scheme is updated. The simulation results show that TP-TSFLA can achieve a relative high localization ratio without time synchronization.

Element fracture technique for hypervelocity impact simulation

NASA Astrophysics Data System (ADS)

Zhang, Xiao-tian; Li, Xiao-gang; Liu, Tao; Jia, Guang-hui

2015-05-01

Hypervelocity impact dynamics is the theoretical support of spacecraft shielding against space debris. The numerical simulation has become an important approach for obtaining the ballistic limits of the spacecraft shields. Currently, the most widely used algorithm for hypervelocity impact is the smoothed particle hydrodynamics (SPH). Although the finite element method (FEM) is widely used in fracture mechanics and low-velocity impacts, the standard FEM can hardly simulate the debris cloud generated by hypervelocity impact. This paper presents a successful application of the node-separation technique for hypervelocity impact debris cloud simulation. The node-separation technique assigns individual/coincident nodes for the adjacent elements, and it applies constraints to the coincident node sets in the modeling step. In the explicit iteration, the cracks are generated by releasing the constrained node sets that meet the fracture criterion. Additionally, the distorted elements are identified from two aspects - self-piercing and phase change - and are deleted so that the constitutive computation can continue. FEM with the node-separation technique is used for thin-wall hypervelocity impact simulations. The internal structures of the debris cloud in the simulation output are compared with that in the test X-ray graphs under different material fracture criteria. It shows that the pressure criterion is more appropriate for hypervelocity impact. The internal structures of the debris cloud are also simulated and compared under different thickness-to-diameter ratios (t/D). The simulation outputs show the same spall pattern with the tests. Finally, the triple-plate impact case is simulated with node-separation FEM.

Lymph node harvest in colon and rectal cancer: Current considerations

PubMed Central

McDonald, James R; Renehan, Andrew G; O’Dwyer, Sarah T; Haboubi, Najib Y

2012-01-01

The prognostic significance of identifying lymph node (LN) metastases following surgical resection for colon and rectal cancer is well recognized and is reflected in accurate staging of the disease. An established body of evidence exists, demonstrating an association between a higher total LN count and improved survival, particularly for node negative colon cancer. In node positive disease, however, the lymph node ratios may represent a better prognostic indicator, although the impact of this on clinical treatment has yet to be universally established. By extension, strategies to increase surgical node harvest and/or laboratory methods to increase LN yield seem logical and might improve cancer staging. However, debate prevails as to whether or not these extrapolations are clinically relevant, particularly when very high LN counts are sought. Current guidelines recommend a minimum of 12 nodes harvested as the standard of care, yet the evidence for such is questionable as it is unclear whether an increasing the LN count results in improved survival. Findings from modern treatments, including down-staging in rectal cancer using pre-operative chemoradiotherapy, paradoxically suggest that lower LN count, or indeed complete absence of LNs, are associated with improved survival; implying that using a specific number of LNs harvested as a measure of surgical quality is not always appropriate. The pursuit of a sufficient LN harvest represents good clinical practice; however, recent evidence shows that the exhaustive searching for very high LN yields may be unnecessary and has little influence on modern approaches to treatment. PMID:22347537

A Two-Phase Time Synchronization-Free Localization Algorithm for Underwater Sensor Networks

PubMed Central

Luo, Junhai; Fan, Liying

2017-01-01

Underwater Sensor Networks (UWSNs) can enable a broad range of applications such as resource monitoring, disaster prevention, and navigation-assistance. Sensor nodes location in UWSNs is an especially relevant topic. Global Positioning System (GPS) information is not suitable for use in UWSNs because of the underwater propagation problems. Hence, some localization algorithms based on the precise time synchronization between sensor nodes that have been proposed for UWSNs are not feasible. In this paper, we propose a localization algorithm called Two-Phase Time Synchronization-Free Localization Algorithm (TP-TSFLA). TP-TSFLA contains two phases, namely, range-based estimation phase and range-free evaluation phase. In the first phase, we address a time synchronization-free localization scheme based on the Particle Swarm Optimization (PSO) algorithm to obtain the coordinates of the unknown sensor nodes. In the second phase, we propose a Circle-based Range-Free Localization Algorithm (CRFLA) to locate the unlocalized sensor nodes which cannot obtain the location information through the first phase. In the second phase, sensor nodes which are localized in the first phase act as the new anchor nodes to help realize localization. Hence, in this algorithm, we use a small number of mobile beacons to help obtain the location information without any other anchor nodes. Besides, to improve the precision of the range-free method, an extension of CRFLA achieved by designing a coordinate adjustment scheme is updated. The simulation results show that TP-TSFLA can achieve a relative high localization ratio without time synchronization. PMID:28358342

Critical temperatures of hybrid laminates using finite elements

NASA Astrophysics Data System (ADS)

Chockalingam, S.; Mathew, T. C.; Singh, G.; Rao, G. V.

1992-06-01

Thermal buckling of antisymmetric cross-ply hybrid laminates is investigated. A one-dimensional finite element based on first-order shear deformation theory, having two nodes and six degrees of freedom per node, namely axial displacement, transverse displacements and rotation of the normal to the beam axis and their derivatives with respect to beam coordinate axis, is employed for this purpose. Various types of hybrid laminates with different combination of glass/epoxy, Kevlar/epoxy and carbon/epoxy are considered. Effects of slenderness ratio, boundary conditions and lay-ups are studied in detail.

Expression of Proteins Involved in Epithelial-Mesenchymal Transition as Predictors of Metastasis and Survival in Breast Cancer Patients

DTIC Science & Technology

2013-11-01

Ptrend 0.78 0.62 0.75 Unconditional logistic regression was used to estimate odds ratios (OR) and 95 % confidence intervals (CI) for risk of node...Ptrend 0.71 0.67 Unconditional logistic regression was used to estimate odds ratios (OR) and 95 % confidence intervals (CI) for risk of high-grade tumors... logistic regression was used to estimate odds ratios (OR) and 95 % confidence intervals (CI) for the associations between each of the seven SNPs and

Shared Memory Parallelism for 3D Cartesian Discrete Ordinates Solver

NASA Astrophysics Data System (ADS)

Moustafa, Salli; Dutka-Malen, Ivan; Plagne, Laurent; Ponçot, Angélique; Ramet, Pierre

2014-06-01

This paper describes the design and the performance of DOMINO, a 3D Cartesian SN solver that implements two nested levels of parallelism (multicore+SIMD) on shared memory computation nodes. DOMINO is written in C++, a multi-paradigm programming language that enables the use of powerful and generic parallel programming tools such as Intel TBB and Eigen. These two libraries allow us to combine multi-thread parallelism with vector operations in an efficient and yet portable way. As a result, DOMINO can exploit the full power of modern multi-core processors and is able to tackle very large simulations, that usually require large HPC clusters, using a single computing node. For example, DOMINO solves a 3D full core PWR eigenvalue problem involving 26 energy groups, 288 angular directions (S16), 46 × 106 spatial cells and 1 × 1012 DoFs within 11 hours on a single 32-core SMP node. This represents a sustained performance of 235 GFlops and 40:74% of the SMP node peak performance for the DOMINO sweep implementation. The very high Flops/Watt ratio of DOMINO makes it a very interesting building block for a future many-nodes nuclear simulation tool.

Influence of thyroid gland status on the thyroglobulin cutoff level in washout fluid from cervical lymph nodes of patients with recurrent/metastatic papillary thyroid cancer.

PubMed

Lee, Jun Ho; Lee, Hyun Chul; Yi, Ha Woo; Kim, Bong Kyun; Bae, Soo Youn; Lee, Se Kyung; Choe, Jun-Ho; Kim, Jung-Han; Kim, Jee Soo

2016-04-01

The influence of serum thyroglobulin (Tg) and thyroidectomy status on Tg in fine-needle aspiration cytology (FNAC) washout fluid is unclear. A total of 282 lymph nodes were prospectively subjected to FNAC, fine-needle aspiration (FNA)-Tg measurement, and frozen and permanent biopsies. We evaluated the diagnostic performance of several predetermined FNA-Tg cutoff values for recurrence/metastasis in lymph nodes according to thyroidectomy status. The diagnostic performance of FNA-Tg varied according to thyroidectomy status. The optimized cutoff value of FNA-Tg was 2.2 ng/mL. However, among FNAC-negative lymph nodes, the FNA-Tg cutoff value of 0.9 ng/mL showed better diagnostic performance in patients with a thyroid gland. An FNA-Tg/serum-Tg cutoff ratio of 1 showed the best diagnostic performance in patients without a thyroid gland. Applying the optimal cutoff values of FNA-Tg according to thyroid gland status and serum Tg level facilitates the diagnostic evaluation of neck lymph node recurrences/metastases in patients with papillary thyroid carcinoma (PTC). © 2015 Wiley Periodicals, Inc. Head Neck 38: E1705-E1712, 2016. © 2015 Wiley Periodicals, Inc.

Synchronous Firefly Algorithm for Cluster Head Selection in WSN

PubMed Central

Baskaran, Madhusudhanan; Sadagopan, Chitra

2015-01-01

Wireless Sensor Network (WSN) consists of small low-cost, low-power multifunctional nodes interconnected to efficiently aggregate and transmit data to sink. Cluster-based approaches use some nodes as Cluster Heads (CHs) and organize WSNs efficiently for aggregation of data and energy saving. A CH conveys information gathered by cluster nodes and aggregates/compresses data before transmitting it to a sink. However, this additional responsibility of the node results in a higher energy drain leading to uneven network degradation. Low Energy Adaptive Clustering Hierarchy (LEACH) offsets this by probabilistically rotating cluster heads role among nodes with energy above a set threshold. CH selection in WSN is NP-Hard as optimal data aggregation with efficient energy savings cannot be solved in polynomial time. In this work, a modified firefly heuristic, synchronous firefly algorithm, is proposed to improve the network performance. Extensive simulation shows the proposed technique to perform well compared to LEACH and energy-efficient hierarchical clustering. Simulations show the effectiveness of the proposed method in decreasing the packet loss ratio by an average of 9.63% and improving the energy efficiency of the network when compared to LEACH and EEHC. PMID:26495431

R2NA: Received Signal Strength (RSS) Ratio-Based Node Authentication for Body Area Network

PubMed Central

Wu, Yang; Wang, Kai; Sun, Yongmei; Ji, Yuefeng

2013-01-01

The body area network (BAN) is an emerging branch of wireless sensor networks for personalized applications. The services in BAN usually have a high requirement on security, especially for the medical diagnosis. One of the fundamental directions to ensure security in BAN is how to provide node authentication. Traditional research using cryptography relies on prior secrets shared among nodes, which leads to high resource cost. In addition, most existing non-cryptographic solutions exploit out-of-band (OOB) channels, but they need the help of additional hardware support or significant modifications to the system software. To avoid the above problems, this paper presents a proximity-based node authentication scheme, which only uses wireless modules equipped on sensors. With only one sensor and one control unit (CU) in BAN, we could detect a unique physical layer characteristic, namely, the difference between the received signal strength (RSS) measured on different devices in BAN. Through the above-mentioned particular difference, we can tell whether the sender is close enough to be legitimate. We validate our scheme through both theoretical analysis and experiments, which are conducted on the real Shimmer nodes. The results demonstrate that our proposed scheme has a good security performance.

Second-harmonic generation reveals a relationship between metastatic potential and collagen fiber structure

NASA Astrophysics Data System (ADS)

Burke, Kathleen A.; Dawes, Ryan P.; Cheema, Mehar K.; Perry, Seth; Brown, Edward

2014-02-01

Second Harmonic Generation (SHG) of collagen signals allows for the analysis of collagen structural changes throughout metastatic progression. The directionality of coherent SHG signals, measured through the ratio of the forward-propagating to backward propagating signal (F/B ratio), is affected by fibril diameter, spacing, and order versus disorder of fibril packing within a fiber. As tumors interact with their microenvironment and metastasize, it causes changes in these parameters, and concurrent changes in the F/B ratio. Specifically, the F/B ratio of breast tumors that are highly metastatic to the lymph nodes is significantly higher than those in tumors with restricted lymph node involvement. We utilized in vitro analysis of tumor cell motility through collagen gels of different microstructures, and hence different F/B ratios, to explore the relationship between collagen microstructures and metastatic capabilities of the tumor. By manipulating environmental factors of fibrillogenesis and biochemical factors of fiber composition we created methods of varying the average F/B ratio of the gel, with significant changes in fiber structure occurring as a result of alterations in incubation temperature and increasing type III collagen presence. A migration assay was performed using simultaneous SHG and fluorescent imaging to measure average penetration depth of human tumor cells into the gels of significantly different F/B ratios, with preliminary data demonstrating that cells penetrate deeper into gels of higher F/B ratio caused by lower type III collagen concentration. Determining the role of collagen structure in tumor cell motility will aid in the future prediction metastatic capabilities of a primary tumor.

The elastic ratio: introducing curvature into ratio-based image segmentation.

PubMed

Schoenemann, Thomas; Masnou, Simon; Cremers, Daniel

2011-09-01

We present the first ratio-based image segmentation method that allows imposing curvature regularity of the region boundary. Our approach is a generalization of the ratio framework pioneered by Jermyn and Ishikawa so as to allow penalty functions that take into account the local curvature of the curve. The key idea is to cast the segmentation problem as one of finding cyclic paths of minimal ratio in a graph where each graph node represents a line segment. Among ratios whose discrete counterparts can be globally minimized with our approach, we focus in particular on the elastic ratio [Formula: see text] that depends, given an image I, on the oriented boundary C of the segmented region candidate. Minimizing this ratio amounts to finding a curve, neither small nor too curvy, through which the brightness flux is maximal. We prove the existence of minimizers for this criterion among continuous curves with mild regularity assumptions. We also prove that the discrete minimizers provided by our graph-based algorithm converge, as the resolution increases, to continuous minimizers. In contrast to most existing segmentation methods with computable and meaningful, i.e., nondegenerate, global optima, the proposed approach is fully unsupervised in the sense that it does not require any kind of user input such as seed nodes. Numerical experiments demonstrate that curvature regularity allows substantial improvement of the quality of segmentations. Furthermore, our results allow drawing conclusions about global optima of a parameterization-independent version of the snakes functional: the proposed algorithm allows determining parameter values where the functional has a meaningful solution and simultaneously provides the corresponding global solution.

Axillary lymph node metastases in patients with breast carcinomas: assessment with nonenhanced versus uspio-enhanced MR imaging.

PubMed

Memarsadeghi, Mazda; Riedl, Christopher C; Kaneider, Andreas; Galid, Arik; Rudas, Margaretha; Matzek, Wolfgang; Helbich, Thomas H

2006-11-01

To prospectively assess the accuracy of nonenhanced versus ultrasmall superparamagnetic iron oxide (USPIO)-enhanced magnetic resonance (MR) imaging for depiction of axillary lymph node metastases in patients with breast carcinoma, with histopathologic findings as reference standard. The study was approved by the university ethics committee; written informed consent was obtained. Twenty-two women (mean age, 60 years; range, 40-79 years) with breast carcinomas underwent nonenhanced and USPIO-enhanced (2.6 mg of iron per kilogram of body weight intravenously administered) transverse T1-weighted and transverse and sagittal T2-weighted and T2*-weighted MR imaging in adducted and elevated arm positions. Two experienced radiologists, blinded to the histopathologic findings, analyzed images of axillary lymph nodes with regard to size, morphologic features, and USPIO uptake. A third independent radiologist served as a tiebreaker if consensus between two readers could not be reached. Visual and quantitative analyses of MR images were performed. Sensitivity, specificity, and accuracy values were calculated. To assess the effect of USPIO after administration, signal-to-noise ratio (SNR) changes were statistically analyzed with repeated-measurements analysis of variance (mixed model) for MR sequences. At nonenhanced MR imaging, of 133 lymph nodes, six were rated as true-positive, 99 as true-negative, 23 as false-positive, and five as false-negative. At USPIO-enhanced MR imaging, 11 lymph nodes were rated as true-positive, 120 as true-negative, two as false-positive, and none as false-negative. In two metastatic lymph nodes in two patients with more than one metastatic lymph node, a consensus was not reached. USPIO-enhanced MR imaging revealed a node-by-node sensitivity, specificity, and accuracy of 100%, 98%, and 98%, respectively. At USPIO-enhanced MR imaging, no metastatic lymph nodes were missed on a patient-by-patient basis. Significant interactions indicating differences in the decrease of SNR values for metastatic and nonmetastatic lymph nodes were found for all sequences (P < .001 to P = .022). USPIO-enhanced MR imaging appears valuable for assessment of axillary lymph node metastases in patients with breast carcinomas and is superior to nonenhanced MR imaging.

Sentinel Lymph Node Biopsy After Neoadjuvant Chemotherapy in Patients With an Initial Diagnosis of Cytology-Proven Lymph Node-Positive Breast Cancer.

PubMed

Enokido, Katsutoshi; Watanabe, Chie; Nakamura, Seigo; Ogiya, Akiko; Osako, Tomo; Akiyama, Futoshi; Yoshimura, Akiyo; Iwata, Hiroji; Ohno, Shinji; Kojima, Yasuyuki; Tsugawa, Koichiro; Motomura, Kazuyoshi; Hayashi, Naoki; Yamauchi, Hideko; Sato, Nobuaki

2016-08-01

Sentinel lymph node biopsy (SNB) is the standard treatment of node-negative breast cancer; however, whether SNB should be performed for patients with node-positive disease before neoadjuvant chemotherapy (NAC) is controversial. We evaluated the accuracy of SNB after NAC in patients with breast cancer with nodal metastasis before chemotherapy to determine the false-negative rate (FNR) and detection rate for SNB. In the present multicenter prospective study performed from September 2011 to April 2013, 143 patients with breast cancer and positive axillary nodes, proved by fine needle aspiration cytology at the initial diagnosis (stage T1-T3N1M0), were enrolled. All patients underwent breast surgery with SNB and complete axillary lymph node dissection. After NAC, the pathologic complete nodal response rate was 52.4%. The sentinel lymph node could be identified in 130 cases (90.9%); the FNR was 16.0% (13 of 81). The FNR of each clinical subtype was 42.1% (8 of 19) for the estrogen receptor-positive and human epithelial growth factor 2 (HER2)-negative (luminal type), 16.7% (2 of 12) for ER-positive and HER2-positive (luminal-HER2 type), 3.2% (1 of 31) for HER2-positive (HER2-enriched type), and 10.5% (2 of 19) for ER-negative and HER2-negative (triple-negative breast cancer; P = .003). The FNR was significantly greater in the luminal than in the nonluminal type (odds ratio, 9.91; 95% confidence interval, 6.77-14.52). SNB after NAC in patients with initially node-positive breast cancer was technically feasible but should not be recommended for the luminal subtype. However, the tumor subtype can guide patient selection, and axillary lymph node dissection could be omitted for the luminal-HER2, HER2-enriched, and triple-negative breast cancer subtypes. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Quality of care along the cancer continuum: does receiving adequate lymph node evaluation for colon cancer lead to comprehensive postsurgical care?

PubMed

Parsons, Helen M; Tuttle, Todd M; Kuntz, Karen M; Begun, James W; McGovern, Patricia M; Virnig, Beth A

2012-09-01

Among surgically treated patients with colon cancer, lower long-term mortality has been demonstrated in those with 12 or more lymph nodes evaluated. We examined whether patients receiving adequate lymph node evaluation were also more likely to receive comprehensive postsurgical care, leading to lower mortality. We used the 1992 to 2007 Surveillance, Epidemiology, and End Results (SEER)-Medicare data to identify surgically treated American Joint Committee on Cancer (AJCC) stage III colon cancer patients. We used chi-square analyses and logistic regression to evaluate the association between adequate (≥12) lymph node evaluation and receipt of postsurgical care (adjuvant chemotherapy, surveillance colonoscopy, CT scans, and CEA testing) and Cox proportional hazards regression to evaluate 10-year all-cause mortality, adjusting for postsurgical care. Among 17,906 surgically treated stage III colon cancer patients, adequate (≥12) lymph node evaluation was not associated with receiving comprehensive postsurgical care after adjustment for patient and tumor characteristics (p > 0.05 for all). Initially, adequate lymph node evaluation was associated with lower all-cause mortality (hazard ratio [HR] 0.88; 95% CI [0.85 to 0.91]), but among 3-year survivors, the impact of adequate lymph node evaluation on lower mortality was diminished (HR 0.94; 95% CI [0.88 to 1.01]). However, receiving comprehensive postsurgical care was associated with continued lower mortality in 3-year survivors. Adequate lymph node evaluation for colon cancer was associated with lower mortality among all patients. However, among 3-year survivors, the association between lymph node evaluation and lower hazard of death was no longer significant, while postsurgical care remained strongly associated with lower long-term mortality, indicating that postsurgical care may partially explain the relationship between lymph node evaluation and mortality. Copyright © 2012 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Effect of time to sentinel-node biopsy on the prognosis of cutaneous melanoma.

PubMed

Tejera-Vaquerizo, Antonio; Nagore, Eduardo; Puig, Susana; Robert, Caroline; Saiag, Philippe; Martín-Cuevas, Paula; Gallego, Elena; Herrera-Acosta, Enrique; Aguilera, José; Malvehy, Josep; Carrera, Cristina; Cavalcanti, Andrea; Rull, Ramón; Vilalta-Solsona, Antonio; Lannoy, Emilie; Boutros, Celine; Benannoune, Naima; Tomasic, Gorana; Aegerte, Philippe; Vidal-Sicart, Sergi; Palou, Josep; Alos, L Lúcia; Requena, Celia; Traves, Víctor; Pla, Ángel; Bolumar, Isidro; Soriano, Virtudes; Guillén, Carlos; Herrera-Ceballos, Enrique

2015-09-01

In patients with primary cutaneous melanoma, there is generally a delay between excisional biopsy of the primary tumour and sentinel-node biopsy. The objective of this study is to analyse the prognostic implications of this delay. This was an observational, retrospective, cohort study in four tertiary referral hospitals. A total of 1963 patients were included. The factor of interest was the interval between the date of the excisional biopsy of the primary melanoma and the date of the sentinel-node biopsy (delay time) in the prognosis. The primary outcome was melanoma-specific survival and disease-free survival. A delay time of 40 days or less (hazard ratio (HR), 1.7; confidence interval (CI), 1.2-2.5) increased Breslow thickness (Breslow ⩾ 2 mm, HR, > 3.7; CI, 1.4-10.7), ulceration (HR, 1.6; CI, 1.1-2.3), sentinel-node metastasis (HR, 2.9; CI, 1.9-4.2), and primary melanoma localised in the head or neck were independently associated with worse melanoma-specific survival (all P < 0.03). The stratified analysis showed that the effect of delay time was at the expense of the patients with a negative sentinel-node biopsy and without regression. Early sentinel-node biopsy is associated with worse survival in patients with cutaneous melanoma. Copyright © 2015 Elsevier Ltd. All rights reserved.

Recommendation for incorporation of a different lymph node scoring system in future AJCC N category for oral cancer.

PubMed

Lee, Ching-Chih; Su, Yu-Chieh; Hung, Shih-Kai; Chen, Po-Chun; Huang, Chung-I; Huang, Wei-Lun; Lin, Yu-Wei; Yang, Ching-Chieh

2017-10-26

To compare the prognostic value of 3 different lymph node scoring systems " log odds of positive nodes (LODDS), lymph node ratio (rN), and lymph node yield " in an effort to improve the staging of oral cancer. We identified 3958 oral cancer patients from Surveillance, Epidemiology, and End Results database from 2007 to 2013. In univariate analysis, LODDS, pN, rN, and lymph node yield were prognostic factors for 5-year disease-specific survival (DSS) and overall survival (OS). Multivariate analysis indicated that patients with LODDS 4 had worst 5-year DSS and OS. Stage migration occurred in pN1 and pN2 patients with LODDS 4. In pN1 patients, those with LODDS 4 had the worst 5-year DSS (41.2%) and OS (31.6%) than patients with pN1 and LODDS 2-3. In pN2 patients, those with LODDS4 had the worst 5-year DSS (34.5%) and OS (27.4%) than patients with pN2 and LODDS 2-3. The proposed staging system, which incorporates LODDS with AJCC pN, had better discriminability and prediction accuracy for predicting survival. We also noted that patients with LODDS 4 given adjuvant radiotherapy had better 5-year DSS and OS. The LODDS should be considered as a future candidate measurement for N category in oral cancer.

Dynamic behavior of microscale particles controlled by standing bulk acoustic waves

DOE Office of Scientific and Technical Information (OSTI.GOV)

Greenhall, J.; Raeymaekers, B., E-mail: bart.raeymaekers@utah.edu; Guevara Vasquez, F.

2014-10-06

We analyze the dynamic behavior of a spherical microparticle submerged in a fluid medium, driven to the node of a standing bulk acoustic wave created by two opposing transducers. We derive the dynamics of the fluid-particle system taking into account the acoustic radiation force and the time-dependent and time-independent drag force acting on the particle. Using this dynamic model, we characterize the transient and steady-state behavior of the fluid-particle system as a function of the particle and fluid properties and the transducer operating parameters. The results show that the settling time and percent overshoot of the particle trajectory are dependentmore » on the ratio of the acoustic radiation force and time-independent damping force. In addition, we show that the particle oscillates around the node of the standing wave with an amplitude that depends on the ratio of the time-dependent drag forces and the particle inertia.« less

Assessment of Ultrasound Features Predicting Axillary Nodal Metastasis in Breast Cancer: The Impact of Cortical Thickness

PubMed Central

Stachs, A.; Thi, A. Tra-Ha; Dieterich, M.; Stubert, J.; Hartmann, S.; Glass, Ä.; Reimer, T.; Gerber, B.

2015-01-01

Purpose: To evaluate the accuracy of axillary ultrasound (AUS) in detecting nodal metastasis in patients with early-stage breast cancer and to identify AUS features with high predictive power. Materials and Methods: Prospective single-center preliminary study in 105 patients with a primary diagnosis of breast cancer and clinically negative axilla. AUS was performed using a 12 MHz linear-array transducer before ultrasound-guided needle biopsy. Nodal characteristics (shape, longitudinal-transverse [LT] axis ratio, margins, cortical thickness, hyperechoic hilum) were correlated with histopathological nodal status after SLNB or axillary lymph node dissection (ALND). Results: Nodal metastases were present in 42/105 patients (40.0%). Univariate analyses showed that absence of hyperechoic hilum, round shape, LT axis ratio<2, sharp margins and cortical thickness>3 mm were associated with lymph node metastasis. Multivariate logistic regression analysis revealed cortical thickness > 3 mm as an independent predictive parameter for nodal involvement. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 66.7, 74.6, 63.6, 77.0% and 71.4% respectively when cortical thickness > 3 mm was applied as the criterion for AUS positivity. Axillary tumor volume was low in patients with pT1/2 tumors and negative AUS, since only 3.2% of patients had > 2 metastatic lymph nodes. Conclusion: Cortical thickness>3 mm is a reliable predictor of nodal metastatic involvement. Negative AUS does not exclude lymph node metastases, but extensive axillary tumor volume is rare. PMID:27689144

Invasive intraductal papillary mucinous neoplasm versus sporadic pancreatic adenocarcinoma: a stage-matched comparison of outcomes.

PubMed

Wasif, Nabil; Bentrem, David J; Farrell, James J; Ko, Clifford Y; Hines, Oscar J; Reber, Howard A; Tomlinson, James S

2010-07-15

Although invasive intraductal papillary mucinous neoplasm (IPMN) of the pancreas is thought to be more indolent than sporadic pancreatic adenocarcinoma (PAC), the natural history remains poorly defined. The authors compared survival and identify prognostic factors after resection for invasive IPMN versus stage-matched PAC. The Surveillance, Epidemiology, and End Results database (1991-2005) was used to identify 729 patients with invasive IPMN and 8082 patients with PAC who underwent surgical resection. Patients with resected invasive IPMN experienced improved overall survival when compared with resected PAC (median survival, 21 vs 14 months; P<.001). Stratification by nodal status demonstrated no difference in survival among lymph node-positive patients; however, median survival of resected, lymph node-negative, invasive IPMN was significantly improved compared with lymph node-negative PAC (34 vs 18 months; P<.001). On multivariate analysis, PAC histology was an adverse predictor of overall survival (hazard ratio [HR], 1.31; 95% confidence interval [CI], 1.15-1.50) compared with invasive IPMN. For patients with invasive IPMN, positive lymph nodes (HR, 1.98; 95% CI, 1.50-2.60), high tumor grade (HR, 1.74; 95% CI, 1.31-2.31), tumor size>2 cm (HR, 1.50; 95% CI, 1.04-2.19), and age>66 years (HR, 1.33; 95% CI, 1.03-1.73) were adverse predictors of survival. Although lymph node-negative invasive IPMN showed improved survival after resection compared with lymph node-negative PAC, the natural history of lymph node-positive invasive IPMN mimicked that of lymph node-positive PAC. The authors also identified adverse predictors of survival in invasive IPMN to guide discussions regarding use of adjuvant therapies and prognosis after resection of invasive IPMN. Copyright (c) 2010 American Cancer Society.

The Effect of Thyroiditis on the Yield of Central Compartment Lymph Nodes in Patients with Papillary Thyroid Cancer.

PubMed

Lai, Victoria; Yen, Tina W F; Rose, Brian T; Fareau, Gilbert G; Misustin, Sarah M; Evans, Douglas B; Wang, Tracy S

2015-12-01

In patients who have undergone thyroidectomy and central compartment neck dissection (CCND) for papillary thyroid cancer (PTC), visualization of enlarged lymph nodes may lead to more extensive CCND. This study sought to determine the effect of patient age and the presence of thyroiditis on the number of malignant and total lymph nodes resected in patients who underwent CCND for PTC. This retrospective review examined a prospective database of patients who underwent total thyroidectomy and CCND for PTC between April 2009 and June 2013 and had thyroiditis on the final pathology. The patients were categorized into age groups by decade (18-29, 30-39, 40-49, 50-59, and ≥60 years) and compared with a control group of patients matched by age, gender, and tumor size. Of 74 patients with thyroiditis, 64 (87 %) were women. The median age of the patients was 47.5 years (range 18.2-72.0 years). The patients with thyroiditis had more lymph nodes resected than those without thyroiditis (median 11 vs 7; p < 0.01). However, these patients had fewer malignant lymph nodes (median 0 vs 1.5; p = 0.06), resulting in a lower lymph node ratio (0 vs 0.18; p = 0.02) for the entire cohort, but particularly for the youngest (18-29 years) and oldest (≥60 years) age groups. Patients with thyroiditis and PTC who underwent CCND had more lymph nodes resected but a had lower proportion of metastatic lymph nodes than those without thyroiditis. Given the relatively low yield of malignant cervical lymphadenopathy, a more judicious approach to CCND might be considered, particularly for the youngest and oldest patients with PTC and thyroiditis.

T2AR: trust-aware ad-hoc routing protocol for MANET.

PubMed

Dhananjayan, Gayathri; Subbiah, Janakiraman

2016-01-01

Secure data transfer against the malicious attacks is an important issue in an infrastructure-less independent network called mobile ad-hoc network (MANET). Trust assurance between MANET nodes is the key parameter in the high-security provision under dynamic topology variations and open wireless constraints. But, the malicious behavior of nodes reduces the trust level of the nodes that leads to an insecure data delivery. The increase in malicious attacks causes the excessive energy consumption that leads to a reduction of network lifetime. The lack of positional information update of the nodes in ad-hoc on-demand vector (AODV) protocol during the connection establishment offers less trust level between the nodes. Hence, the trust rate computation using energy and mobility models and its update are the essential tasks for secure data delivery. This paper proposes a trust-aware ad-hoc routing (T2AR) protocol to improve the trust level between the nodes in MANET. The proposed method modifies the traditional AODV routing protocol with the constraints of trust rate, energy, mobility based malicious behavior prediction. The packet sequence ID matching from the log reports of neighbor nodes determine the trust rate that avoids the malicious report generation. Besides, the direct and indirect trust observation schemes utilization increases the trust level. Besides, the received signal strength indicator utilization determines the trusted node is within the communication range or not. The comparative analysis between the proposed T2AR with the existing methods such as TRUNCMAN, RBT, GR, FBR and DICOTIDS regarding the average end-to-end delay, throughput, false positives, packet delivery ratio shows the effectiveness of T2AR in the secure MANET environment design.

Breast Cancer Subtype is Associated With Axillary Lymph Node Metastasis

PubMed Central

He, Zhen-Yu; Wu, San-Gang; Yang, Qi; Sun, Jia-Yuan; Li, Feng-Yan; Lin, Qin; Lin, Huan-Xin

2015-01-01

Abstract The purpose of this study was to assess whether breast cancer subtype (BCS) as determined by estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 can predict the axillary lymph node metastasis in breast cancer. Patients who received breast conserving surgery or mastectomy and axillary lymph node dissection were identified from 2 cancer centers. The associations between clinicopathological variables and axillary lymph node involvement were evaluated in univariate and multivariate regression analyses. A total of 3471 patients met the inclusion criteria, and 53.0% had axillary lymph node metastases at diagnosis. Patients with hormone receptor (HR)−/human epidermal growth factor receptor 2 (HER2)− subtype had a higher grade disease and the lowest rate of lymphovascular invasion. Univariate and multivariable logistic regression analyses showed that BCS was significantly associated with lymph node involvement. Patients with the HR−/HER2− subtype had the lowest odds of having nodal positivity than those with other BCSs. HR+/HER2− (odds ratio [OR] 1.651, 95% confidence interval [CI]: 1.349–2.021, P < 0.001), HR+/HER2+ (OR 1.958, 95%CI 1.542–2.486, P < 0.001), and HR−/HER2+ (OR 1.525, 95%CI 1.181–1.970, P < 0.001) tumors had higher risk of nodal positivity than the HR−/HER2− subtype. The other independent predictors of nodal metastases included tumor size, tumor grade, and lymphovascular invasion. Breast cancer subtype can predict the presence of axillary lymph node metastasis in breast cancer. HR−/HER2− is associated with a reduced risk of axillary lymph node metastasis compared to other BCSs. Our findings may play an important role in guiding axillary treatment considerations if further confirmed in larger sample size studies. PMID:26632910

Normal Axillary Lymph Node Variability Between White and Black Women on Breast MRI.

PubMed

Grimm, Lars J; Viradia, Neal K; Johnson, Karen S

2018-03-01

This study aimed to determine if there were differences in the imaging features of normal lymph nodes between white and black women using magnetic resonance imaging. Following institutional review board approval, we identified white and black women who underwent breast magnetic resonance imaging from November 1, 2008 to December 31, 2013 at our institution. To identify normal lymph nodes for measurement, patients with any benign or malignant causes for lymph node enlargement and patients with any subsequent breast cancer in the following 2 years were excluded. Black and white women were age matched at a 1:2 ratio. The largest lymph node in each axilla was measured for the long-axis length and maximal cortical thickness. Comparisons were made between white and black women using a conditional logistic regression to control for matching. There were 55 black women and 110 white women for analysis. The mean lymph node long-axis length was 14.7 ± 5.3 mm for black women and 14.4 ± 6.4 mm for white women (P = .678). The mean maximum cortical thickness was 3.3 ± 1.6 mm for black women and 2.6 ± 1.4 mm for Caucasian women (P < .001). A significantly higher percentage of black than white women had cortical thicknesses greater than threshold values of 3, 4, 5, 6, and 7 mm (P < .01 for all). The normal lymph node cortical thickness in black women is significantly greater than in white women, which should be considered when deciding to recommend a lymph node biopsy. Copyright © 2018 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Use of Lymph Node Ultrasound Prior to Sentinel Lymph Node Biopsy in 384 Patients with Melanoma: A Cost-Effectiveness Analysis.

PubMed

Olmedo, D; Brotons-Seguí, M; Del Toro, C; González, M; Requena, C; Traves, V; Pla, A; Bolumar, I; Moreno-Ramírez, D; Nagore, E

2017-12-01

Locoregional lymph node ultrasound is not typically included in guidelines as part of the staging process prior to sentinel lymph node biopsy (SLNB). The objective of the present study was to make a clinical and economic analysis of lymph node ultrasound prior to SLNB. We performed a retrospective study of 384 patients with clinical stage I-II primary melanoma who underwent locorregional lymph node ultrasound (with or without ultrasound-guided biopsy) prior to SLNB between 2004 and 2015. We evaluated the reliability and cost-effectiveness of the strategy. Use of locorregional lymph node ultrasound avoided SLNB in 23 patients (6%). Ultrasound had a sensitivity of 46% and specificity of 76% for the detection of metastatic lymph nodes that were not clinically palpable. False negatives were significantly more common in patients aged over 60 years and in tumors with a thickness of less than 2mm. The staging process using SLNB and ultrasound with ultrasound-guided biopsy produced an increase of €16.30 in the unit price. Our cost-effectiveness analysis identified the staging protocol with ultrasound and SLNB as the dominant strategy, with a lower cost-effectiveness ratio than the alternative, consisting of SLNB alone (8,095.24 vs. €28,605.00). Ultrasound with ultrasound-guided biopsy for the diagnostic staging of melanoma prior to SLNB is a useful and cost-effective tool. This procedure does not substitute SLNB, though it does allow to avoid SLNB in a not insignificant proportion of patients. Copyright © 2017 AEDV. Publicado por Elsevier España, S.L.U. All rights reserved.

Predicting axillary lymph node metastasis from kinetic statistics of DCE-MRI breast images

NASA Astrophysics Data System (ADS)

Ashraf, Ahmed B.; Lin, Lilie; Gavenonis, Sara C.; Mies, Carolyn; Xanthopoulos, Eric; Kontos, Despina

2012-03-01

The presence of axillary lymph node metastases is the most important prognostic factor in breast cancer and can influence the selection of adjuvant therapy, both chemotherapy and radiotherapy. In this work we present a set of kinetic statistics derived from DCE-MRI for predicting axillary node status. Breast DCE-MRI images from 69 women with known nodal status were analyzed retrospectively under HIPAA and IRB approval. Axillary lymph nodes were positive in 12 patients while 57 patients had no axillary lymph node involvement. Kinetic curves for each pixel were computed and a pixel-wise map of time-to-peak (TTP) was obtained. Pixels were first partitioned according to the similarity of their kinetic behavior, based on TTP values. For every kinetic curve, the following pixel-wise features were computed: peak enhancement (PE), wash-in-slope (WIS), wash-out-slope (WOS). Partition-wise statistics for every feature map were calculated, resulting in a total of 21 kinetic statistic features. ANOVA analysis was done to select features that differ significantly between node positive and node negative women. Using the computed kinetic statistic features a leave-one-out SVM classifier was learned that performs with AUC=0.77 under the ROC curve, outperforming the conventional kinetic measures, including maximum peak enhancement (MPE) and signal enhancement ratio (SER), (AUCs of 0.61 and 0.57 respectively). These findings suggest that our DCE-MRI kinetic statistic features can be used to improve the prediction of axillary node status in breast cancer patients. Such features could ultimately be used as imaging biomarkers to guide personalized treatment choices for women diagnosed with breast cancer.

Completion Dissection or Observation for Sentinel-Node Metastasis in Melanoma.

PubMed

Faries, Mark B; Thompson, John F; Cochran, Alistair J; Andtbacka, Robert H; Mozzillo, Nicola; Zager, Jonathan S; Jahkola, Tiina; Bowles, Tawnya L; Testori, Alessandro; Beitsch, Peter D; Hoekstra, Harald J; Moncrieff, Marc; Ingvar, Christian; Wouters, Michel W J M; Sabel, Michael S; Levine, Edward A; Agnese, Doreen; Henderson, Michael; Dummer, Reinhard; Rossi, Carlo R; Neves, Rogerio I; Trocha, Steven D; Wright, Frances; Byrd, David R; Matter, Maurice; Hsueh, Eddy; MacKenzie-Ross, Alastair; Johnson, Douglas B; Terheyden, Patrick; Berger, Adam C; Huston, Tara L; Wayne, Jeffrey D; Smithers, B Mark; Neuman, Heather B; Schneebaum, Schlomo; Gershenwald, Jeffrey E; Ariyan, Charlotte E; Desai, Darius C; Jacobs, Lisa; McMasters, Kelly M; Gesierich, Anja; Hersey, Peter; Bines, Steven D; Kane, John M; Barth, Richard J; McKinnon, Gregory; Farma, Jeffrey M; Schultz, Erwin; Vidal-Sicart, Sergi; Hoefer, Richard A; Lewis, James M; Scheri, Randall; Kelley, Mark C; Nieweg, Omgo E; Noyes, R Dirk; Hoon, Dave S B; Wang, He-Jing; Elashoff, David A; Elashoff, Robert M

2017-06-08

Sentinel-lymph-node biopsy is associated with increased melanoma-specific survival (i.e., survival until death from melanoma) among patients with node-positive intermediate-thickness melanomas (1.2 to 3.5 mm). The value of completion lymph-node dissection for patients with sentinel-node metastases is not clear. In an international trial, we randomly assigned patients with sentinel-node metastases detected by means of standard pathological assessment or a multimarker molecular assay to immediate completion lymph-node dissection (dissection group) or nodal observation with ultrasonography (observation group). The primary end point was melanoma-specific survival. Secondary end points included disease-free survival and the cumulative rate of nonsentinel-node metastasis. Immediate completion lymph-node dissection was not associated with increased melanoma-specific survival among 1934 patients with data that could be evaluated in an intention-to-treat analysis or among 1755 patients in the per-protocol analysis. In the per-protocol analysis, the mean (±SE) 3-year rate of melanoma-specific survival was similar in the dissection group and the observation group (86±1.3% and 86±1.2%, respectively; P=0.42 by the log-rank test) at a median follow-up of 43 months. The rate of disease-free survival was slightly higher in the dissection group than in the observation group (68±1.7% and 63±1.7%, respectively; P=0.05 by the log-rank test) at 3 years, based on an increased rate of disease control in the regional nodes at 3 years (92±1.0% vs. 77±1.5%; P<0.001 by the log-rank test); these results must be interpreted with caution. Nonsentinel-node metastases, identified in 11.5% of the patients in the dissection group, were a strong, independent prognostic factor for recurrence (hazard ratio, 1.78; P=0.005). Lymphedema was observed in 24.1% of the patients in the dissection group and in 6.3% of those in the observation group. Immediate completion lymph-node dissection increased the rate of regional disease control and provided prognostic information but did not increase melanoma-specific survival among patients with melanoma and sentinel-node metastases. (Funded by the National Cancer Institute and others; MSLT-II ClinicalTrials.gov number, NCT00297895 .).

Clinicopathologic Features of Submucosal Esophageal Squamous Cell Carcinoma.

PubMed

Emi, Manabu; Hihara, Jun; Hamai, Yoichi; Furukawa, Takaoki; Ibuki, Yuta; Okada, Morihito

2017-12-01

The prognoses of submucosal esophageal squamous cell carcinoma patients vary. Patients with favorable prognoses may receive less invasive or nonsurgical interventions, whereas patients with poor prognoses or advanced esophageal cancer may require aggressive treatments. We sought to identify prognostic factors for patients with submucosal esophageal squamous cell carcinoma, focusing on lymph node metastasis and recurrence. We included 137 submucosal esophageal squamous cell carcinoma patients who had undergone transthoracic esophagectomy with systematic extended lymph node dissection. Submucosal tumors were classified as SM1, SM2, and SM3 according to the depth of invasion. Prognostic factors were determined by univariable and multivariable analyses. Lymph node metastasis was observed in 18.8%, 30.5%, and 50.0% of SM1, SM2, and SM3 cases, respectively. The overall 5-year recurrence rate was 21.9%; the rates for SM1, SM2, and SM3 tumors were 9.4%, 18.6%, and 34.8%, respectively. The SM1 tumors all recurred locoregionally; distant metastasis occurred in SM2 and SM3 cases. The 5-year overall survival rates were 83%, 77%, and 59% for SM1, SM2, and SM3 cases, respectively. On univariable analysis, lymph node metastasis, depth of submucosal invasion (SM3 versus SM1/2), and tumor location (upper thoracic versus mid/lower thoracic) were poor prognostic factors for overall survival. Multivariable Cox regression analyses identified depth of submucosal invasion (hazard ratio 2.51, 95% confidence interval: 1.37 to 4.61) and tumor location (hazard ratio 2.43, 95% confidence interval: 1.18 to 4.63) as preoperative prognostic factors. Tumor location (upper thoracic) and infiltration (SM3) are the worse prognostic factors of submucosal esophageal squamous cell carcinoma, but lymph node metastasis is not a predictor of poorer prognosis. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Regional Nodal Irradiation in Early-Stage Breast Cancer.

PubMed

Whelan, Timothy J; Olivotto, Ivo A; Parulekar, Wendy R; Ackerman, Ida; Chua, Boon H; Nabid, Abdenour; Vallis, Katherine A; White, Julia R; Rousseau, Pierre; Fortin, Andre; Pierce, Lori J; Manchul, Lee; Chafe, Susan; Nolan, Maureen C; Craighead, Peter; Bowen, Julie; McCready, David R; Pritchard, Kathleen I; Gelmon, Karen; Murray, Yvonne; Chapman, Judy-Anne W; Chen, Bingshu E; Levine, Mark N

2015-07-23

Most women with breast cancer who undergo breast-conserving surgery receive whole-breast irradiation. We examined whether the addition of regional nodal irradiation to whole-breast irradiation improved outcomes. We randomly assigned women with node-positive or high-risk node-negative breast cancer who were treated with breast-conserving surgery and adjuvant systemic therapy to undergo either whole-breast irradiation plus regional nodal irradiation (including internal mammary, supraclavicular, and axillary lymph nodes) (nodal-irradiation group) or whole-breast irradiation alone (control group). The primary outcome was overall survival. Secondary outcomes were disease-free survival, isolated locoregional disease-free survival, and distant disease-free survival. Between March 2000 and February 2007, a total of 1832 women were assigned to the nodal-irradiation group or the control group (916 women in each group). The median follow-up was 9.5 years. At the 10-year follow-up, there was no significant between-group difference in survival, with a rate of 82.8% in the nodal-irradiation group and 81.8% in the control group (hazard ratio, 0.91; 95% confidence interval [CI], 0.72 to 1.13; P=0.38). The rates of disease-free survival were 82.0% in the nodal-irradiation group and 77.0% in the control group (hazard ratio, 0.76; 95% CI, 0.61 to 0.94; P=0.01). Patients in the nodal-irradiation group had higher rates of grade 2 or greater acute pneumonitis (1.2% vs. 0.2%, P=0.01) and lymphedema (8.4% vs. 4.5%, P=0.001). Among women with node-positive or high-risk node-negative breast cancer, the addition of regional nodal irradiation to whole-breast irradiation did not improve overall survival but reduced the rate of breast-cancer recurrence. (Funded by the Canadian Cancer Society Research Institute and others; MA.20 ClinicalTrials.gov number, NCT00005957.).

Oncological outcome following laparoscopic versus open surgery for cancer in the transverse colon: a nationwide cohort study.

PubMed

Nordholm-Carstensen, Andreas; Jensen, Kristian Kiim; Krarup, Peter-Martin

2018-03-30

The literature on transverse colonic cancer resection is sparse. The optimal surgical approach for this disease is thus unknown. This study aimed to examine laparoscopic versus open surgery for transverse colonic cancer. This study was a nationwide, retrospective cohort study of all patients registered with a transverse colonic cancer in Denmark between 2010 and 2013. Data were obtained from the Danish Colorectal Cancer Group, the Danish Pathology Registry, Danish National Patient Registry, and patients' records. Main outcome measures were surgical resection plane, lymph node yield, and long-term cancer recurrence and survival. In total, 357 patients were included. Non-mesocolic resection was more frequent with laparoscopic compared with open resection (adjusted odds ratio 2.44, 95% CI 1.29-4.60, P = 0.006). Median number of harvested lymph nodes was higher after open compared with laparoscopic resection (22 versus 19, P = 0.03). Non-mesocolic resection (adjusted hazard ratio 2.45, 95% CI 1.25-4.79, P = 0.01) and increasing tumor stage (P < 0.001) were factors associated with recurrence. Cancer recurrence was significantly associated with an increased risk of mortality (adjusted hazard ratio 4.32, 95% CI 2.75-6.79, P < 0.001). Overall mortality was, however, not associated with the surgical approach or surgical plane. Although associated with a lower rate of mesocolic resection plane and fewer lymph nodes harvested, laparoscopic surgery for transverse colonic cancers led to similar long-term results compared with open resection.

Strategy of Using Intratreatment Hypoxia Imaging to Selectively and Safely Guide Radiation Dose De-escalation Concurrent With Chemotherapy for Locoregionally Advanced Human Papillomavirus–Related Oropharyngeal Carcinoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Nancy, E-mail: leen2@mskcc.org; Schoder, Heiko; Beattie, Brad

Purpose: To report a small substudy of an ongoing large, multi-arm study using functional imaging to assess pre-/intratreatment hypoxia for all head and neck cancer, in which we hypothesized that pre- and early-treatment hypoxia assessment using functional positron emission tomography (PET) imaging may help select which human papillomavirus (HPV)-positive (HPV{sup +}) oropharyngeal cancer (OPC) patients can safely receive radiation de-escalation without jeopardizing treatment outcomes. Methods and Materials: Patients with HPV{sup +} oropharyngeal carcinoma were enrolled on an institutional review board–approved prospective study of which de-escalation based on imaging response was done for node(s) only. Pretreatment {sup 18}F-fluorodeoxyglucose and dynamic {sup 18}F-FMISOmore » (fluoromisonidazole) positron emission tomography (PET) scans were performed. For patients with pretreatment hypoxia on{sup 18}F-FMISO PET (defined as a >1.2 tumor to muscle standard uptake value ratio), a repeat scan was done 1 week after chemoradiation. Patients without pretreatment hypoxia or with resolution of hypoxia on repeat scan received a 10-Gy dose reduction to metastatic lymph node(s). The 2-year local, regional, distant metastasis–free, and overall survival rates were estimated using the Kaplan-Meier product-limit method. A subset of patients had biopsy of a hypoxic node done under image guidance. Results: Thirty-three HPV{sup +} OPC patients were enrolled in this pilot study. One hundred percent showed pretreatment hypoxia (at primary site and/or node[s]), and among these, 48% resolved (at primary site and/or node[s]); 30% met criteria and received 10-Gy reduction to the lymph node(s). At the median follow-up of 32 months (range, 21-61 months), the 2-year locoregional control rate was 100%. One patient failed distantly with persistence of hypoxia on {sup 18}F-FMISO PET. The 2-year distant metastasis–free rate was 97%. The 2-year OS rate was 100%. Hypoxia on imaging was confirmed pathologically. Conclusions: Hypoxia is present in HPV{sup +} tumors but resolves within 1 week of treatment in 48% of cases either at the primary site and/or lymph node(s). Our 100% locoregional control rate suggests that intratreatment functional imaging used to selectively de-escalate node(s) to 60 Gy was confirmed safe using our stringent imaging criteria. Intratreatment functional imaging warrants further study to determine its ultimate role in de-escalation treatment strategies.« less

Strategy of Using Intratreatment Hypoxia Imaging to Selectively and Safely Guide Radiation Dose De-escalation Concurrent With Chemotherapy for Locoregionally Advanced Human Papillomavirus-Related Oropharyngeal Carcinoma.

PubMed

Lee, Nancy; Schoder, Heiko; Beattie, Brad; Lanning, Ryan; Riaz, Nadeem; McBride, Sean; Katabi, Nora; Li, Duan; Yarusi, Brett; Chan, Susie; Mitrani, Lindsey; Zhang, Zhigang; Pfister, David G; Sherman, Eric; Baxi, Shrujal; Boyle, Jay; Morris, Luc G T; Ganly, Ian; Wong, Richard; Humm, John

2016-09-01

To report a small substudy of an ongoing large, multi-arm study using functional imaging to assess pre-/intratreatment hypoxia for all head and neck cancer, in which we hypothesized that pre- and early-treatment hypoxia assessment using functional positron emission tomography (PET) imaging may help select which human papillomavirus (HPV)-positive (HPV(+)) oropharyngeal cancer (OPC) patients can safely receive radiation de-escalation without jeopardizing treatment outcomes. Patients with HPV(+) oropharyngeal carcinoma were enrolled on an institutional review board-approved prospective study of which de-escalation based on imaging response was done for node(s) only. Pretreatment (18)F-fluorodeoxyglucose and dynamic (18)F-FMISO (fluoromisonidazole) positron emission tomography (PET) scans were performed. For patients with pretreatment hypoxia on(18)F-FMISO PET (defined as a >1.2 tumor to muscle standard uptake value ratio), a repeat scan was done 1 week after chemoradiation. Patients without pretreatment hypoxia or with resolution of hypoxia on repeat scan received a 10-Gy dose reduction to metastatic lymph node(s). The 2-year local, regional, distant metastasis-free, and overall survival rates were estimated using the Kaplan-Meier product-limit method. A subset of patients had biopsy of a hypoxic node done under image guidance. Thirty-three HPV(+) OPC patients were enrolled in this pilot study. One hundred percent showed pretreatment hypoxia (at primary site and/or node[s]), and among these, 48% resolved (at primary site and/or node[s]); 30% met criteria and received 10-Gy reduction to the lymph node(s). At the median follow-up of 32 months (range, 21-61 months), the 2-year locoregional control rate was 100%. One patient failed distantly with persistence of hypoxia on (18)F-FMISO PET. The 2-year distant metastasis-free rate was 97%. The 2-year OS rate was 100%. Hypoxia on imaging was confirmed pathologically. Hypoxia is present in HPV(+) tumors but resolves within 1 week of treatment in 48% of cases either at the primary site and/or lymph node(s). Our 100% locoregional control rate suggests that intratreatment functional imaging used to selectively de-escalate node(s) to 60 Gy was confirmed safe using our stringent imaging criteria. Intratreatment functional imaging warrants further study to determine its ultimate role in de-escalation treatment strategies. Copyright © 2016 Elsevier Inc. All rights reserved.

Efficiency of B-mode Ultrasound and Strain Elastography in Differentiating Between Benign and Malignant Cervical Lymph Nodes.

PubMed

Turgut, Eser; Celenk, Cetin; Tanrivermis Sayit, Asli; Bekci, Tumay; Gunbey, Hediye Pinar; Aslan, Kerim

2017-09-01

The purpose of this study was to evaluate the diagnostic accuracy and efficiency of ultrasonography (US), especially when combined with strain elastography (SE), in differentiating between benign and malignant cervical lymph nodes (LNs). Forty-one LNs were examined by B-mode US, power Doppler US, and SE. The following imaging features were analyzed: shape, echogenicity, echogenic hilum, calcification, intranodal vascular pattern, elasticity scores (5 categories), and strain ratio. The average strain ratio was calculated as the mean strain of the adjacent sternocleidomastoid muscle divided by the mean strain of the target LN. The results of the US and SE features were compared with the histopathologic findings. The imaging features that were significantly associated with malignant LNs were an increased short-to-long axis diameter ratio, abnormal or absence of hilum, microcalcification, type 2-3-4 vascularity, 3-4-5 elasticity scores, and a high level of strain ratio (P < 0.05). The cutoff value of the strain index was detected as 1.18. According to this, there was a significant difference (P = 0.004) in the strain index between benign and malignant LNs. Strain elastography is useful in differentiating between benign and malignant cervical LNs, thereby informing decisions to perform a biopsy and/or surgery, and facilitating follow-up.

A social activity and physical contact-based routing algorithm in mobile opportunistic networks for emergency response to sudden disasters

NASA Astrophysics Data System (ADS)

Wang, Xiaoming; Lin, Yaguang; Zhang, Shanshan; Cai, Zhipeng

2017-05-01

Sudden disasters such as earthquake, flood and hurricane necessitate the employment of communication networks to carry out emergency response activities. Routing has a significant impact on the functionality, performance and flexibility of communication networks. In this article, the routing problem is studied considering the delivery ratio of messages, the overhead ratio of messages and the average delay of messages in mobile opportunistic networks (MONs) for enterprise-level emergency response communications in sudden disaster scenarios. Unlike the traditional routing methods for MONS, this article presents a new two-stage spreading and forwarding dynamic routing algorithm based on the proposed social activity degree and physical contact factor for mobile customers. A new modelling method for describing a dynamic evolving process of the topology structure of a MON is first proposed. Then a multi-copy spreading strategy based on the social activity degree of nodes and a single-copy forwarding strategy based on the physical contact factor between nodes are designed. Compared with the most relevant routing algorithms such as Epidemic, Prophet, Labelled-sim, Dlife-comm and Distribute-sim, the proposed routing algorithm can significantly increase the delivery ratio of messages, and decrease the overhead ratio and average delay of messages.

Ultrasonographic Evaluation of Cervical Lymph Nodes in Thyroid Cancer.

PubMed

Machado, Maria Regina Marrocos; Tavares, Marcos Roberto; Buchpiguel, Carlos Alberto; Chammas, Maria Cristina

2017-02-01

Objective To determine what ultrasonographic features can identify metastatic cervical lymph nodes, both preoperatively and in recurrences after complete thyroidectomy. Study Design Prospective. Setting Outpatient clinic, Department of Head and Neck Surgery, School of Medicine, University of São Paulo, Brazil. Subjects and Methods A total of 1976 lymph nodes were evaluated in 118 patients submitted to total thyroidectomy with or without cervical lymph node dissection. All the patients were examined by cervical ultrasonography, preoperatively and/or postoperatively. The following factors were assessed: number, size, shape, margins, presence of fatty hilum, cortex, echotexture, echogenicity, presence of microcalcification, presence of necrosis, and type of vascularity. The specificity, sensitivity, positive predictive value, and negative predictive value of each variable were calculated. Univariate and multivariate logistic regression analyses were conducted. A receiver operator characteristic (ROC) curve was plotted to determine the best cutoff value for the number of variables to discriminate malignant lymph nodes. Results Significant differences were found between metastatic and benign lymph nodes with regard to all of the variables evaluated ( P < .05). Logistic regression analysis revealed that size and echogenicity were the best combination of altered variables (odds ratio, 40.080 and 7.288, respectively) in discriminating malignancy. The ROC curve analysis showed that 4 was the best cutoff value for the number of altered variables to discriminate malignant lymph nodes, with a combined specificity of 85.7%, sensitivity of 96.4%, and efficiency of 91.0%. Conclusion Greater diagnostic accuracy was achieved by associating the ultrasonographic variables assessed rather than by considering them individually.

Importance of Delphian Lymph Node Evaluation in Autoimmune Thyroiditis: Fact or Fiction?

PubMed Central

Ormeci, Tugrul; Çolakoğulları, Mukaddes; Orhan, İsrafil

2016-01-01

Summary Background Our main objective was to evaluate the association between autoimmune thyroiditis and the Delphian lymph node during different stages of thyroiditis. Material/Methods The relationships between the ultrasonography (US) results of thyroiditis and characteristics of the Delphian lymph node in different stages of AT were evaluated. Thyroid hormone and antibody levels were assessed. A total of 126 patients were divided into four groups according to the thyroid US findings: Group 1: control cases; Group 2: indeterminate cases; Group 3: established thyroiditis cases; Group 4: advanced-late stage thyroiditis cases. Indeterminate cases attended a 1-year follow-up, and the cases with a sonographic finding matching thyroiditis formed Group 2. Results The rate of Delphian lymph node presence in Group 4 was significantly higher than in Groups 1 and 2 (p<0.01). In addition, its presence was significantly higher in Group 3 than in Group 1 (p<0.05). Although there was a difference in Delphian lymph node presence between Groups 2 and 3, it was not significant (p=0.052), nor was there a significant difference between Groups 1 and 2 (p>0.05). Both the long and short axis measurements were significantly higher in Groups 2, 3, and 4 compared to those in the control group. However, the same increase was not observed in the long/short axis ratio. Conclusions Both the presence and dimensions of the Delphian lymph node were highly correlated with the progress of autoimmune thyroiditis. Evaluating the Delphian lymph nodes might prevent missing a diagnosis of autoimmune thyroiditis. PMID:26985243

Cervical node metastasis in T1 squamous cell carcinoma of oral tongue- pattern and the predictive factors.

PubMed

S, Vishak; Rohan, Vinayak

2014-06-01

The squamous cell carcinoma (SCC) of the oral tongue is a common cancer in India. Elective lymphadenectomy is generally performed in all patients with T2-T4 tumors. In this study we have tried to analyze the pattern and risk factors associated with lymph node metastasis in T1 tongue cancers. A retrospective review of the records of 57 patients undergoing surgery for treatment of T1 sqamous cell carcinoma of oral tongue was carried out. The clinicopatological features of the tumor, pattern of nodal metastasis and the risk factors associated with lymph node metastasis were studied. Totally 57 patients with T1 tumor underwent excision of the primary and modified neck dissection (MND). Lymph node metastasis was found in 36.8 % of the patients. Level I to Level II was the commonest site of metastasis. Skip metastasis at level III and IV was found in 8.5 % of the patients and isolated skip metastasis at level IV in 1.5 % of the patients. The risk factors associated with the lymph node metastasis on univariete analysis were; higher grade, tumor size >1 cm and tumor thickness >3 mm. On multivariate analysis only the tumor thickness was found to be a risk factor for the lymph node metastasis (hazard ratio of 21.59). T1 sqamous cell carcinoma of tongue is associated with a high incidence of lymph node metastasis. Elective neck dissection should be considered in all patients with tumors more than 3 mm in thickness.

A High RORγT/CD3 Ratio is a Strong Prognostic Factor for Postoperative Survival in Advanced Colorectal Cancer: Analysis of Helper T Cell Lymphocytes (Th1, Th2, Th17 and Regulatory T Cells).

PubMed

Yoshida, Naohiro; Kinugasa, Tetsushi; Miyoshi, Hiroaki; Sato, Kensaku; Yuge, Kotaro; Ohchi, Takafumi; Fujino, Shinya; Shiraiwa, Sachiko; Katagiri, Mitsuhiro; Akagi, Yoshito; Ohshima, Koichi

2016-03-01

Tumor-infiltrating lymphocytes (TILs), part of the host immune response, have been widely reported as influential factors in the tumor microenvironment for the clinical outcome of colorectal cancer (CRC). However, the network of helper T cells is very complex, and which T-cell subtypes affect the progression of CRC and postoperative prognosis remains unclear. This study investigated the expression of several subtypes of TILs including T helper type 1 (Th1), Th2, Th17, and regulatory T (Treg) cells to determine their correlation with clinicopathologic features and postoperative prognosis. The study investigated the expression of TILs using immunohistochemistry of tissue microarray samples for 199 CRC patients. The number of each T-cell subtype infiltrating tumors was counted using ImageJ software. The relationship between TIL marker expression, clinicopathologic features, and prognosis was analyzed. A high RORγT/CD3 ratio (Th17 ratio) was significantly correlated with lymph node metastasis (p = 0.002), and a high of Foxp3/CD3 ratio (Treg ratio) was correlated with tumor location in the colon (p = 0.04), as shown by the Chi square test. In multivariate analysis, a high RORγT/CD3 ratio was the only independent prognostic factor for overall survival (p = 0.04; hazard ratio [HR], 1.84; 95% confidence interval [CI] 1.02-3.45). This study confirmed a high RORγT/CD3 ratio as a strong prognostic marker for postoperative survival. The immunohistochemistry results suggest that Th17 may affect lymph node metastasis in CRC. If new immunotherapies reducing Th17 expression are established, they may improve the efficiency of cancer treatment and prolong the survival of patients with CRC.

Integrated data lookup and replication scheme in mobile ad hoc networks

NASA Astrophysics Data System (ADS)

Chen, Kai; Nahrstedt, Klara

2001-11-01

Accessing remote data is a challenging task in mobile ad hoc networks. Two problems have to be solved: (1) how to learn about available data in the network; and (2) how to access desired data even when the original copy of the data is unreachable. In this paper, we develop an integrated data lookup and replication scheme to solve these problems. In our scheme, a group of mobile nodes collectively host a set of data to improve data accessibility for all members of the group. They exchange data availability information by broadcasting advertising (ad) messages to the group using an adaptive sending rate policy. The ad messages are used by other nodes to derive a local data lookup table, and to reduce data redundancy within a connected group. Our data replication scheme predicts group partitioning based on each node's current location and movement patterns, and replicates data to other partitions before partitioning occurs. Our simulations show that data availability information can quickly propagate throughout the network, and that the successful data access ratio of each node is significantly improved.

Loss surface of XOR artificial neural networks

NASA Astrophysics Data System (ADS)

Mehta, Dhagash; Zhao, Xiaojun; Bernal, Edgar A.; Wales, David J.

2018-05-01

Training an artificial neural network involves an optimization process over the landscape defined by the cost (loss) as a function of the network parameters. We explore these landscapes using optimization tools developed for potential energy landscapes in molecular science. The number of local minima and transition states (saddle points of index one), as well as the ratio of transition states to minima, grow rapidly with the number of nodes in the network. There is also a strong dependence on the regularization parameter, with the landscape becoming more convex (fewer minima) as the regularization term increases. We demonstrate that in our formulation, stationary points for networks with Nh hidden nodes, including the minimal network required to fit the XOR data, are also stationary points for networks with Nh+1 hidden nodes when all the weights involving the additional node are zero. Hence, smaller networks trained on XOR data are embedded in the landscapes of larger networks. Our results clarify certain aspects of the classification and sensitivity (to perturbations in the input data) of minima and saddle points for this system, and may provide insight into dropout and network compression.

Mobile Sinks Assisted Geographic and Opportunistic Routing Based Interference Avoidance for Underwater Wireless Sensor Network

PubMed Central

Ahmed, Farwa; Wadud, Zahid; Alrajeh, Nabil; Alabed, Mohamad Souheil

2018-01-01

The distinctive features of acoustic communication channel-like high propagation delay, multi-path fading, quick attenuation of acoustic signal, etc. limit the utilization of underwater wireless sensor networks (UWSNs). The immutable selection of forwarder node leads to dramatic death of node resulting in imbalanced energy depletion and void hole creation. To reduce the probability of void occurrence and imbalance energy dissipation, in this paper, we propose mobility assisted geo-opportunistic routing paradigm based on interference avoidance for UWSNs. The network volume is divided into logical small cubes to reduce the interference and to make more informed routing decisions for efficient energy consumption. Additionally, an optimal number of forwarder nodes is elected from each cube based on its proximity with respect to the destination to avoid void occurrence. Moreover, the data packets are recovered from void regions with the help of mobile sinks which also reduce the data traffic on intermediate nodes. Extensive simulations are performed to verify that our proposed work maximizes the network lifetime and packet delivery ratio. PMID:29614794

Mobile Sinks Assisted Geographic and Opportunistic Routing Based Interference Avoidance for Underwater Wireless Sensor Network.

PubMed

Ahmed, Farwa; Wadud, Zahid; Javaid, Nadeem; Alrajeh, Nabil; Alabed, Mohamad Souheil; Qasim, Umar

2018-04-02

The distinctive features of acoustic communication channel-like high propagation delay, multi-path fading, quick attenuation of acoustic signal, etc. limit the utilization of underwater wireless sensor networks (UWSNs). The immutable selection of forwarder node leads to dramatic death of node resulting in imbalanced energy depletion and void hole creation. To reduce the probability of void occurrence and imbalance energy dissipation, in this paper, we propose mobility assisted geo-opportunistic routing paradigm based on interference avoidance for UWSNs. The network volume is divided into logical small cubes to reduce the interference and to make more informed routing decisions for efficient energy consumption. Additionally, an optimal number of forwarder nodes is elected from each cube based on its proximity with respect to the destination to avoid void occurrence. Moreover, the data packets are recovered from void regions with the help of mobile sinks which also reduce the data traffic on intermediate nodes. Extensive simulations are performed to verify that our proposed work maximizes the network lifetime and packet delivery ratio.

The golden proportion in facial soft-tissues of Vietnamese females.

PubMed

Nguyen, Minh Son; Saag, Mare; Le, Van Nho; Nguyen, Thuy Trang; Nguyen, Bui Bao Tien; Jagomägi, Triin

2016-01-01

Objective of the current study was to evaluate proportions of frontal facial soft-tissues of Vietnamese females correspond to the golden proportion (GP). Sixty frontal facial photographs of Vietnamese female students aged 19 years were selected. The selected participants had symmetrical face, a Class I relationship occlusion, complete lip closure, and no history of trauma and orthodontic treatment. The photographic record was set-up with a white backdrop, fill light, a reflector, a camera Canon 650D and subjects were asked to sit in a standard position. Trichion (TR), Temporal soft tissue (TS), Lateral canthus (LC), Lateral nasal (LN), Chilion (CH), and Menton (ME) point were used for photometric measurements on CorelDRAW Graphic X3 software. The vertical facial proportions (mean, percentage compared with GP) were significantly higher than the GP including: LC-CH:CH-ME (1.661, 102%), LN-ME:LC-LN (1.729, 106%), TR-ME:LC-ME (1.739, 107%), TR-LN:LN-ME (1.759, 108%). Whereas TR-ME:LN-ME; CH-ME:LN-CH; LC-LN:LN-CH had ratios of 84% - 92% and were significantly smaller in comparison with GP. The horizontal facial proportions of CHR-L:LNR-L, LCR-L:CHR-L and TSR-L:LCR-L deviated from the GP with mean values of 1.221, 1.922 and 1.229, respectively. The new mean values of TR-ME:LC-ME (1.733), TR-LN:LN-ME (1.732), LC-ME:TR-LC (1.374), CH-ME:LN-CH (1.524), which were predictable changes in proportions, can be significantly converged to the GP if LC-CH:CH-ME is equal to the GP. Soft-tissue facial proportions of Vietnamese females did not correspond to the GP. Changing the lower third face may create harmony vertical facial proportions.

Analysis of Perioperative Chemotherapy in Resected Pancreatic Cancer: Identifying the Number and Sequence of Chemotherapy Cycles Needed to Optimize Survival.

PubMed

Epelboym, Irene; Zenati, Mazen S; Hamad, Ahmad; Steve, Jennifer; Lee, Kenneth K; Bahary, Nathan; Hogg, Melissa E; Zeh, Herbert J; Zureikat, Amer H

2017-09-01

Receipt of 6 cycles of adjuvant chemotherapy (AC) is standard of care in pancreatic cancer (PC). Neoadjuvant chemotherapy (NAC) is increasingly utilized; however, optimal number of cycles needed alone or in combination with AC remains unknown. We sought to determine the optimal number and sequence of perioperative chemotherapy cycles in PC. Single institutional review of all resected PCs from 2008 to 2015. The impact of cumulative number of chemotherapy cycles received (0, 1-5, and ≥6 cycles) and their sequence (NAC, AC, or NAC + AC) on overall survival was evaluated Cox-proportional hazard modeling, using 6 cycles of AC as reference. A total of 522 patients were analyzed. Based on sample size distribution, four combinations were evaluated: 0 cycles = 12.1%, 1-5 cycles of combined NAC + AC = 29%, 6 cycles of AC = 25%, and ≥6 cycles of combined NAC + AC = 34%, with corresponding survival. 13.1, 18.5, 37, and 36.8 months. On MVA (P < 0.0001), tumor stage [hazard ratio (HR) 1.35], LNR (HR 4.3), and R1 margins (HR 1.77) were associated with increased hazard of death. Compared with 6 cycles AC, receipt of 0 cycles [HR 3.57, confidence interval (CI) 2.47-5.18] or 1-5 cycles in any combination (HR 2.37, CI 1.73-3.23) was associated with increased hazard of death, whereas receipt of ≥6 cycles in any sequence was associated with optimal and comparable survival (HR 1.07, CI 0.78-1.47). Receipt of 6 or more perioperative cycles of chemotherapy either as combined neoadjuvant and adjuvant or adjuvant alone may be associated with optimal and comparable survival in resected PC.

An Energy Scaled and Expanded Vector-Based Forwarding Scheme for Industrial Underwater Acoustic Sensor Networks with Sink Mobility.

PubMed

Wadud, Zahid; Hussain, Sajjad; Javaid, Nadeem; Bouk, Safdar Hussain; Alrajeh, Nabil; Alabed, Mohamad Souheil; Guizani, Nadra

2017-09-30

Industrial Underwater Acoustic Sensor Networks (IUASNs) come with intrinsic challenges like long propagation delay, small bandwidth, large energy consumption, three-dimensional deployment, and high deployment and battery replacement cost. Any routing strategy proposed for IUASN must take into account these constraints. The vector based forwarding schemes in literature forward data packets to sink using holding time and location information of the sender, forwarder, and sink nodes. Holding time suppresses data broadcasts; however, it fails to keep energy and delay fairness in the network. To achieve this, we propose an Energy Scaled and Expanded Vector-Based Forwarding (ESEVBF) scheme. ESEVBF uses the residual energy of the node to scale and vector pipeline distance ratio to expand the holding time. Resulting scaled and expanded holding time of all forwarding nodes has a significant difference to avoid multiple forwarding, which reduces energy consumption and energy balancing in the network. If a node has a minimum holding time among its neighbors, it shrinks the holding time and quickly forwards the data packets upstream. The performance of ESEVBF is analyzed through in network scenario with and without node mobility to ensure its effectiveness. Simulation results show that ESEVBF has low energy consumption, reduces forwarded data copies, and less end-to-end delay.

Performance Analysis of Evolutionary Algorithms for Steiner Tree Problems.

PubMed

Lai, Xinsheng; Zhou, Yuren; Xia, Xiaoyun; Zhang, Qingfu

2017-01-01

The Steiner tree problem (STP) aims to determine some Steiner nodes such that the minimum spanning tree over these Steiner nodes and a given set of special nodes has the minimum weight, which is NP-hard. STP includes several important cases. The Steiner tree problem in graphs (GSTP) is one of them. Many heuristics have been proposed for STP, and some of them have proved to be performance guarantee approximation algorithms for this problem. Since evolutionary algorithms (EAs) are general and popular randomized heuristics, it is significant to investigate the performance of EAs for STP. Several empirical investigations have shown that EAs are efficient for STP. However, up to now, there is no theoretical work on the performance of EAs for STP. In this article, we reveal that the (1+1) EA achieves 3/2-approximation ratio for STP in a special class of quasi-bipartite graphs in expected runtime [Formula: see text], where [Formula: see text], [Formula: see text], and [Formula: see text] are, respectively, the number of Steiner nodes, the number of special nodes, and the largest weight among all edges in the input graph. We also show that the (1+1) EA is better than two other heuristics on two GSTP instances, and the (1+1) EA may be inefficient on a constructed GSTP instance.

LAG-3 in Non-Small-cell Lung Cancer: Expression in Primary Tumors and Metastatic Lymph Nodes Is Associated With Improved Survival.

PubMed

Hald, Sigurd M; Rakaee, Mehrdad; Martinez, Inigo; Richardsen, Elin; Al-Saad, Samer; Paulsen, Erna-Elise; Blix, Egil Støre; Kilvaer, Thomas; Andersen, Sigve; Busund, Lill-Tove; Bremnes, Roy M; Donnem, Tom

2018-05-01

Lymphocyte activation gene-3 (LAG-3) is an immune checkpoint receptor and a putative therapeutic target in non-small-cell lung cancer (NSCLC). We explored the prognostic effect of LAG-3 + tumor-infiltrating lymphocytes (TILs) in primary tumors and metastatic lymph nodes in NSCLC and its potential for inclusion in an immunoscore, supplementing the TNM classification. Primary tumor tissue from 553 stage I-IIIB NSCLC patients and 143 corresponding metastatic lymph nodes were collected. The expression of LAG-3 was evaluated by immunohistochemistry on tissue microarrays. On univariate analysis, LAG-3 + TILs in the intraepithelial and stromal compartments of primary tumors and in the intraepithelial and extraepithelial compartments of metastatic lymph nodes were associated with improved disease-specific survival (DSS). On multivariate analysis, stromal LAG-3 + TILs were a significant independent predictor of improved DSS (hazard ratio [HR], 0.59; 95% confidence interval [CI], 0.43-0.82; P = .002). Stromal LAG-3 + TILs did not have prognostic impact across all pathologic stages. In the metastatic lymph nodes, intraepithelial (HR, 0.61; 95% CI, 0.38-0.99; P = .049) and extraepithelial (HR, 0.54; 95% CI, 0.29-0.70; P < .001) LAG-3 + TILs were independently associated with favorable DSS. LAG-3 + TILs are an independent positive prognostic factor in stage I-IIIB NSCLC. LAG-3 in metastatic lymph nodes is a candidate marker for an immunoscore in NSCLC. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of pathologist's dedication on lymph node detection rate and postoperative survival in colorectal cancer.

PubMed

Unger, L W; Muckenhuber, M; Riss, S; Argeny, S; Stift, J; Mesteri, I; Stift, A

2018-04-28

As adjuvant chemotherapy in colorectal cancer relies on the identification of lymph node metastases, the pathologist's dedication may have a considerable influence on postoperative survival. The aim of this retrospective study was to assess the impact of the pathologist's dedication on lymph node detection rate and postoperative survival in patients operated on by a single experienced colorectal surgeon within a 5-year period. We assessed 229 patients undergoing total mesorectal excision or complete mesocolic excision by the senior author between 1 January 2009 and 31 December 2013. Pathologists were grouped as 'general pathologist' or 'dedicated pathologist' depending on their dedication/specialization. Dedicated pathologists found statistically significantly more lymph nodes in colorectal specimens than general pathologists [23 (interquartile range 24) vs 14 (interquartile range 11), respectively; P < 0.001]. The detection rate of ≥ 12 lymph nodes per specimen was significantly higher in the dedicated pathologist group [65/74 (87.8%) vs 105/155 (67.7%); P = 0.016]. However, postoperative survival did not differ in the respective subgroups. In the multivariable analysis by Cox proportional hazard model, International Union against Cancer Stage IV was the only factor associated with decreased disease-specific survival (hazard ratio 28.257; 95% CI 3.850-207.386; P = 0.001). In our centre, the pathologist's dedication has an impact on lymph node detection rate but does not influence postoperative disease-specific survival. Colorectal Disease © 2018 The Association of Coloproctology of Great Britain and Ireland.

All-Cause Mortality for Life Insurance Applicants with a History of Breast Cancer.

PubMed

Freitas, Stephen A; MacKenzie, Ross; Wylde, David N; Roudebush, Bradley T; Bergstrom, Richard L; Holowaty, J Carl; Hart, Anna; Rigatti, Steven J; Gill, Stacy

2017-01-01

Breast cancer is the most commonly diagnosed cancer worldwide. Breast cancer is also the second leading cause of cancer death among women in the United States after lung cancer with over 40,000 breast cancer deaths occurring each year. The purpose of this research was to determine the all-cause mortality of applicants diagnosed with breast cancer currently or at some time in the past. Life insurance applicants with reported breast cancer were extracted from data covering United States residents between November 2007 and November 2014. Information about these applicants was matched to the Social Security Death Master (SSDMF) file for deaths occurring from 2007 to 2011 and to another commercially available death source file (Other Death Source, ODS) for deaths occurring from 2007 to 2014 to determine vital status. If there was a death from the other death source, then the SSDMF was searched to verify the death. The study had approximately 561,000 person-years of exposure. Actual-to-expected (A/E) mortality ratios were calculated using the Society of Actuaries 2008 Valuation Basic Table (2008VBT), select and ultimate table (age last birthday) and the 2010 US population as expected mortality ratios. Since the A/Es presented in this paper were known to be an underestimate due to the exclusion of the recent SSDMF deaths, comparative analysis of the mortality ratios was done. Since there was no smoking status information in this study, all expected bases were not smoker distinct. Overall, the 35-44 age group had 6.3 times the relative mortality ratio than those in the 65-75 age group. The relative mortality ratio for the 35-44 age group applicants, when cancer severity was accounted for in combination with 3 or more nodes of cancer involvement, was 29.3 times that when compared to those in the 65-75 age group having localized cancer, where no nodes are involved. The 35-44 age group applicants who were diagnosed with cancer within the last year had over 10-fold increase in relative mortality ratios compared to the 65-75 age group, who were over 10 years from diagnosis. Taking the severity of cancer along with time from diagnosis showed over a 12 times relative mortality ratio between the low rate of over 10 years from diagnosis and localized involvement to those diagnosed within the last year having 3 or more nodes with cancer. Applicant age, time since diagnosis and cancer severity were the most significant variables to predict the relative mortality ratios.

Efficient Data Gathering in 3D Linear Underwater Wireless Sensor Networks Using Sink Mobility

PubMed Central

Akbar, Mariam; Javaid, Nadeem; Khan, Ayesha Hussain; Imran, Muhammad; Shoaib, Muhammad; Vasilakos, Athanasios

2016-01-01

Due to the unpleasant and unpredictable underwater environment, designing an energy-efficient routing protocol for underwater wireless sensor networks (UWSNs) demands more accuracy and extra computations. In the proposed scheme, we introduce a mobile sink (MS), i.e., an autonomous underwater vehicle (AUV), and also courier nodes (CNs), to minimize the energy consumption of nodes. MS and CNs stop at specific stops for data gathering; later on, CNs forward the received data to the MS for further transmission. By the mobility of CNs and MS, the overall energy consumption of nodes is minimized. We perform simulations to investigate the performance of the proposed scheme and compare it to preexisting techniques. Simulation results are compared in terms of network lifetime, throughput, path loss, transmission loss and packet drop ratio. The results show that the proposed technique performs better in terms of network lifetime, throughput, path loss and scalability. PMID:27007373

Efficient Data Gathering in 3D Linear Underwater Wireless Sensor Networks Using Sink Mobility.

PubMed

Akbar, Mariam; Javaid, Nadeem; Khan, Ayesha Hussain; Imran, Muhammad; Shoaib, Muhammad; Vasilakos, Athanasios

2016-03-19

Due to the unpleasant and unpredictable underwater environment, designing an energy-efficient routing protocol for underwater wireless sensor networks (UWSNs) demands more accuracy and extra computations. In the proposed scheme, we introduce a mobile sink (MS), i.e., an autonomous underwater vehicle (AUV), and also courier nodes (CNs), to minimize the energy consumption of nodes. MS and CNs stop at specific stops for data gathering; later on, CNs forward the received data to the MS for further transmission. By the mobility of CNs and MS, the overall energy consumption of nodes is minimized. We perform simulations to investigate the performance of the proposed scheme and compare it to preexisting techniques. Simulation results are compared in terms of network lifetime, throughput, path loss, transmission loss and packet drop ratio. The results show that the proposed technique performs better in terms of network lifetime, throughput, path loss and scalability.

Viterbi decoder node synchronization losses in the Reed-Solomon/Veterbi concatenated channel

NASA Technical Reports Server (NTRS)

Deutsch, L. J.; Miller, R. L.

1982-01-01

The Viterbi decoders currently used by the Deep Space Network (DSN) employ an algorithm for maintaining node synchronization that significantly degrades at bit signal-to-noise ratios (SNRs) of below 2.0 dB. In a recent report by the authors, it was shown that the telemetry receiving system, which uses a convolutionally encoded downlink, will suffer losses of 0.85 dB and 1.25 dB respectively at Voyager 2 Uranus and Neptune encounters. This report extends the results of that study to a concatenated (255,223) Reed-Solomon/(7, 1/2) convolutionally coded channel, by developing a new radio loss model for the concatenated channel. It is shown here that losses due to improper node synchronization of 0.57 dB at Uranus and 1.0 dB at Neptune can be expected if concatenated coding is used along with an array of one 64-meter and three 34-meter antennas.

An efficient and reliable geographic routing protocol based on partial network coding for underwater sensor networks.

PubMed

Hao, Kun; Jin, Zhigang; Shen, Haifeng; Wang, Ying

2015-05-28

Efficient routing protocols for data packet delivery are crucial to underwater sensor networks (UWSNs). However, communication in UWSNs is a challenging task because of the characteristics of the acoustic channel. Network coding is a promising technique for efficient data packet delivery thanks to the broadcast nature of acoustic channels and the relatively high computation capabilities of the sensor nodes. In this work, we present GPNC, a novel geographic routing protocol for UWSNs that incorporates partial network coding to encode data packets and uses sensor nodes' location information to greedily forward data packets to sink nodes. GPNC can effectively reduce network delays and retransmissions of redundant packets causing additional network energy consumption. Simulation results show that GPNC can significantly improve network throughput and packet delivery ratio, while reducing energy consumption and network latency when compared with other routing protocols.

Amplify-and-forward cooperative diversity for green UWB-based WBSNs.

PubMed

Shaban, Heba; Abou El-Nasr, Mohamad

2013-01-01

This paper proposes a novel green cooperative diversity technique based on suboptimal template-based ultra-wideband (UWB) wireless body sensor networks (WBSNs) using amplify-and-forward (AF) relays. In addition, it analyzes the bit-error-rate (BER) performance of the proposed nodes. The analysis is based on the moment-generating function (MGF) of the total signal-to-noise ratio (SNR) at the destination. It also provides an approximate value for the total SNR. The analysis studies the performance of equally correlated binary pulse position modulation (EC-BPPM) assuming the sinusoidal and square suboptimal template pulses. Numerical results are provided for the performance evaluation of optimal and suboptimal template-based nodes with and without relay cooperation. Results show that one relay node provides ~23 dB performance enhancement at 1e - 3 BER, which mitigates the effect of the nondesirable non-line-of-sight (NLOS) links in WBSNs.

Amplify-and-Forward Cooperative Diversity for Green UWB-Based WBSNs

PubMed Central

2013-01-01

This paper proposes a novel green cooperative diversity technique based on suboptimal template-based ultra-wideband (UWB) wireless body sensor networks (WBSNs) using amplify-and-forward (AF) relays. In addition, it analyzes the bit-error-rate (BER) performance of the proposed nodes. The analysis is based on the moment-generating function (MGF) of the total signal-to-noise ratio (SNR) at the destination. It also provides an approximate value for the total SNR. The analysis studies the performance of equally correlated binary pulse position modulation (EC-BPPM) assuming the sinusoidal and square suboptimal template pulses. Numerical results are provided for the performance evaluation of optimal and suboptimal template-based nodes with and without relay cooperation. Results show that one relay node provides ~23 dB performance enhancement at 1e − 3 BER, which mitigates the effect of the nondesirable non-line-of-sight (NLOS) links in WBSNs. PMID:24307880

The Case for Modular Redundancy in Large-Scale High Performance Computing Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Engelmann, Christian; Ong, Hong Hoe; Scott, Stephen L

2009-01-01

Recent investigations into resilience of large-scale high-performance computing (HPC) systems showed a continuous trend of decreasing reliability and availability. Newly installed systems have a lower mean-time to failure (MTTF) and a higher mean-time to recover (MTTR) than their predecessors. Modular redundancy is being used in many mission critical systems today to provide for resilience, such as for aerospace and command \\& control systems. The primary argument against modular redundancy for resilience in HPC has always been that the capability of a HPC system, and respective return on investment, would be significantly reduced. We argue that modular redundancy can significantly increasemore » compute node availability as it removes the impact of scale from single compute node MTTR. We further argue that single compute nodes can be much less reliable, and therefore less expensive, and still be highly available, if their MTTR/MTTF ratio is maintained.« less

Decreased Lung Perfusion After Breast/Chest Wall Irradiation: Quantitative Results From a Prospective Clinical Trial

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liss, Adam L., E-mail: adamliss68@gmail.com; Marsh, Robin B.; Kapadia, Nirav S.

Purpose: To quantify lung perfusion changes after breast/chest wall radiation therapy (RT) using pre- and post-RT single photon emission computed tomography/computed tomography (SPECT/CT) attenuation-corrected perfusion scans; and correlate decreased perfusion with adjuvant RT dose for breast cancer in a prospective clinical trial. Methods and Materials: As part of an institutional review board–approved trial studying the impact of RT technique on lung function in node-positive breast cancer, patients received breast/chest wall and regional nodal irradiation including superior internal mammary node RT to 50 to 52.2 Gy with a boost to the tumor bed/mastectomy scar. All patients underwent quantitative SPECT/CT lung perfusion scanningmore » before RT and 1 year after RT. The SPECT/CT scans were co-registered, and the ratio of decreased perfusion after RT relative to the pre-RT perfusion scan was calculated to allow for direct comparison of SPECT/CT perfusion changes with delivered RT dose. The average ratio of decreased perfusion was calculated in 10-Gy dose increments from 0 to 60 Gy. Results: Fifty patients had complete lung SPECT/CT perfusion data available. No patient developed symptoms consistent with pulmonary toxicity. Nearly all patients demonstrated decreased perfusion in the left lung according to voxel-based analyses. The average ratio of lung perfusion deficits increased for each 10-Gy increment in radiation dose to the lung, with the largest changes in regions of lung that received 50 to 60 Gy (ratio 0.72 [95% confidence interval 0.64-0.79], P<.001) compared with the 0- to 10-Gy region. For each increase in 10 Gy to the left lung, the lung perfusion ratio decreased by 0.06 (P<.001). Conclusions: In the assessment of 50 patients with node-positive breast cancer treated with RT in a prospective clinical trial, decreased lung perfusion by SPECT/CT was demonstrated. Our study allowed for quantification of lung perfusion defects in a prospective cohort of breast cancer patients for whom attenuation-corrected SPECT/CT scans could be registered directly to RT treatment fields for precise dose estimates.« less

Management of penile cancer in a Singapore tertiary hospital.

PubMed

Tan, Teck Wei; Chia, Sing Joo; Chong, Kian Tai

2017-06-01

To present our experience of managing penile squamous cell carcinoma (SCC) in a tertiary hospital in Singapore and to evaluate the prognostic value of the inflammatory markers neutrophil-lymphocyte ratio (NLR) and lymphocyte-monocyte ratio (LMR). We reviewed our prospectively maintained Institutional Review Board-approved urological cancer database to identify men treated for penile SCC at our centre between January 2007 and December 2015. For all the patients identified, we collected epidemiological and clinical data. In all, 39 patients were identified who were treated for penile SCC in our centre. The median [interquartile range (IQR)] follow-up was 34 (16.5-66) months. Although very few (23%) of our patients with high-risk clinical node-negative underwent prophylactic inguinal lymph node dissection (ILND), they still had excellent 5-year recurrence-free survival (RFS; 90%) and cancer-specific survival (CSS; 90%). At multivariate analysis, higher N stage was significantly associated with worse RFS and CSS. Patients with a high NLR (≥2.8) had significantly higher T-stage ( P  = 0.006) and worse CSS ( P  < 0.001) than those with a low NLR. Patients with a low LMR (<3.3) had significantly higher T-stage ( P  = 0.013) and worse RFS ( P  = 0.009) and CSS ( P  < 0.022) than those with a high LMR. Although very few of our patients with intermediate- and high-risk clinical node-negative SCC underwent prophylactic ILND, they still had excellent 5-year RFS and CSS. However, survival was poor in patients with node-positive disease. The pre-treatment NLR and LMR could serve as biomarkers to predict the prognosis of patients with penile cancer.

An object-oriented and quadrilateral-mesh based solution adaptive algorithm for compressible multi-fluid flows

NASA Astrophysics Data System (ADS)

Zheng, H. W.; Shu, C.; Chew, Y. T.

2008-07-01

In this paper, an object-oriented and quadrilateral-mesh based solution adaptive algorithm for the simulation of compressible multi-fluid flows is presented. The HLLC scheme (Harten, Lax and van Leer approximate Riemann solver with the Contact wave restored) is extended to adaptively solve the compressible multi-fluid flows under complex geometry on unstructured mesh. It is also extended to the second-order of accuracy by using MUSCL extrapolation. The node, edge and cell are arranged in such an object-oriented manner that each of them inherits from a basic object. A home-made double link list is designed to manage these objects so that the inserting of new objects and removing of the existing objects (nodes, edges and cells) are independent of the number of objects and only of the complexity of O( 1). In addition, the cells with different levels are further stored in different lists. This avoids the recursive calculation of solution of mother (non-leaf) cells. Thus, high efficiency is obtained due to these features. Besides, as compared to other cell-edge adaptive methods, the separation of nodes would reduce the memory requirement of redundant nodes, especially in the cases where the level number is large or the space dimension is three. Five two-dimensional examples are used to examine its performance. These examples include vortex evolution problem, interface only problem under structured mesh and unstructured mesh, bubble explosion under the water, bubble-shock interaction, and shock-interface interaction inside the cylindrical vessel. Numerical results indicate that there is no oscillation of pressure and velocity across the interface and it is feasible to apply it to solve compressible multi-fluid flows with large density ratio (1000) and strong shock wave (the pressure ratio is 10,000) interaction with the interface.

Breast cancer subtypes can be determinant in the decision making process to avoid surgical axillary staging: A retrospective cohort study.

PubMed

Marrazzo, Antonio; Boscaino, Giovanni; Marrazzo, Emilia; Taormina, Pietra; Toesca, Antonio

2015-09-01

The need for performing axillary lymph-node dissection in early breast cancer when the sentinel lymph node (SLN) is positive has been questioned in recent years. The purpose of this study was to identify a low-risk subgroup of early breast cancer patients in whom surgical axillary staging could be avoided, and to assess the probability of having a positive lymph-node (LN). We evaluated the cohort of 612 consecutive women affected by early breast cancer. We considered age, tumor size, histological grade, vascular invasion, lymphatic invasion and cancer subtype (Luminal A, Luminal B HER-2+, Luminal B HER-2-, HER-2+, and Triple Negative) as variables for univariate and multivariate analyses to assess probability of there being a positive SLN o nonsentinel lymph node (NSLN). Chi-square, Fisher's Exact test and Student's t tests were used to investigate the relationship between variables; whereas logit models were used to estimate and quantify the strength of the relationship among some covariates and SLN or the number of metastases. A significant positive effect of vascular invasion and lymphatic invasion (odds ratios are 4 and 6), and a negative effect of TN (odds ratios is 10) were noted. With respect to positive NSLN, size alone has a significant (positive) effect on tumor presence, but focusing on the number of metastases, also age has a (negative) significant effect. This work shows correlation between subtypes and the probability of having positive SLN. Patients not expressing vascular invasion, lymphatic invasion and, moreover, a triple-negative tumor subtype may be good candidates for breast conservative surgery without axillary surgical staging. Copyright © 2015 IJS Publishing Group Limited. Published by Elsevier Ltd. All rights reserved.

Volume-Based Parameters of {sup 18}F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Improve Disease Recurrence Prediction in Postmastectomy Breast Cancer Patients With 1 to 3 Positive Axillary Lymph Nodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakajima, Naomi, E-mail: haruhi0321@gmail.com; Department of Radiology, Ehime University, Ehime; Kataoka, Masaaki

Purpose: To determine whether volume-based parameters on pretreatment {sup 18}F-fluorodeoxyglucose positron emission tomography/computed tomography in breast cancer patients treated with mastectomy without adjuvant radiation therapy are predictive of recurrence. Methods and Materials: We retrospectively analyzed 93 patients with 1 to 3 positive axillary nodes after surgery, who were studied with {sup 18}F-fluorodeoxyglucose positron emission tomography/computed tomography for initial staging. We evaluated the relationship between positron emission tomography parameters, including the maximum standardized uptake value, metabolic tumor volume (MTV), and total lesion glycolysis (TLG), and clinical outcomes. Results: The median follow-up duration was 45 months. Recurrence was observed in 11 patients.more » Metabolic tumor volume and TLG were significantly related to tumor size, number of involved nodes, nodal ratio, nuclear grade, estrogen receptor (ER) status, and triple negativity (TN) (all P values were <.05). In receiver operating characteristic curve analysis, MTV and TLG showed better predictive performance than tumor size, ER status, or TN (area under the curve: 0.85, 0.86, 0.79, 0.74, and 0.74, respectively). On multivariate analysis, MTV was an independent prognostic factor of locoregional recurrence-free survival (hazard ratio 34.42, 95% confidence interval 3.94-882.71, P=.0008) and disease-free survival (DFS) (hazard ratio 13.92, 95% confidence interval 2.65-103.78, P=.0018). The 3-year DFS rate was 93.8% for the lower MTV group (<53.1; n=85) and 25.0% for the higher MTV group (≥53.1; n=8; P<.0001, log–rank test). The 3-year DFS rate for patients with both ER-positive status and MTV <53.1 was 98.2%; and for those with ER-negative status and MTV ≥53.1 it was 25.0% (P<.0001). Conclusions: Volume-based parameters improve recurrence prediction in postmastectomy breast cancer patients with 1 to 3 positive nodes. The addition of MTV to ER status or TN has potential benefits to identify a subgroup at higher risk for recurrence.« less

Directional Migration of Recirculating Lymphocytes through Lymph Nodes via Random Walks

PubMed Central

Thomas, Niclas; Matejovicova, Lenka; Srikusalanukul, Wichat; Shawe-Taylor, John; Chain, Benny

2012-01-01

Naive T lymphocytes exhibit extensive antigen-independent recirculation between blood and lymph nodes, where they may encounter dendritic cells carrying cognate antigen. We examine how long different T cells may spend in an individual lymph node by examining data from long term cannulation of blood and efferent lymphatics of a single lymph node in the sheep. We determine empirically the distribution of transit times of migrating T cells by applying the Least Absolute Shrinkage & Selection Operator () or regularised to fit experimental data describing the proportion of labelled infused cells in blood and efferent lymphatics over time. The optimal inferred solution reveals a distribution with high variance and strong skew. The mode transit time is typically between 10 and 20 hours, but a significant number of cells spend more than 70 hours before exiting. We complement the empirical machine learning based approach by modelling lymphocyte passage through the lymph node . On the basis of previous two photon analysis of lymphocyte movement, we optimised distributions which describe the transit times (first passage times) of discrete one dimensional and continuous (Brownian) three dimensional random walks with drift. The optimal fit is obtained when drift is small, i.e. the ratio of probabilities of migrating forward and backward within the node is close to one. These distributions are qualitatively similar to the inferred empirical distribution, with high variance and strong skew. In contrast, an optimised normal distribution of transit times (symmetrical around mean) fitted the data poorly. The results demonstrate that the rapid recirculation of lymphocytes observed at a macro level is compatible with predominantly randomised movement within lymph nodes, and significant probabilities of long transit times. We discuss how this pattern of migration may contribute to facilitating interactions between low frequency T cells and antigen presenting cells carrying cognate antigen. PMID:23028891

Cervical Node Tuberculosis in Adults of an Urban Middle Class Community: Incidence and Management.

PubMed

Khajanchi, Monty; Bambarkar, Supriya; Gadgil, Anita; Roy, Nobhojit

2016-09-01

The aim of this study is to estimate the incidence of cervical node tuberculosis (TB) in an urban middle class population and to describe an effective protocol for management of cervical lymphadenopathy. The present study is a prospective observational study conducted over two years (2007-2009) in a community hospital in Mumbai, India. All adults (age ≥14 years) presenting with cervical lymphadenopathy, not resolving were included and their details of history and examination were noted. All patients were subjected to fine needle aspiration cytology (FNAC) and biopsy was done selectively as indicated. The response at 1, 3 and 6 months of starting anti tuberculous treatment (ATT) were noted. A total of 191 patients were included in this study. The mean age was 41 years and male to female ratio was 1:1.1 in patients with cervical lymphadenopathy. A history of contact with a patient of TB was the most significantly associated history seen in patients diagnosed to have TB of cervical nodes (p < 0.001). TB (38.7%) followed by reactive nodes (37.6%) were the most common etiologies. A 90.6% response rate was seen in patients taking 6 months ATT for cervical node TB. The incidence of adult (≥14 years) cervical node TB was 52/100,000 people in an urban middle class community in Mumbai. A single swelling in the neck without other associated symptoms or signs was the commonest mode of presentation of TB of the neck nodes. A history of contact with TB, demonstrated an association with the final diagnosis of tuberculous lymphadenopathy.

Multi-channel distributed coordinated function over single radio in wireless sensor networks.

PubMed

Campbell, Carlene E-A; Loo, Kok-Keong Jonathan; Gemikonakli, Orhan; Khan, Shafiullah; Singh, Dhananjay

2011-01-01

Multi-channel assignments are becoming the solution of choice to improve performance in single radio for wireless networks. Multi-channel allows wireless networks to assign different channels to different nodes in real-time transmission. In this paper, we propose a new approach, Multi-channel Distributed Coordinated Function (MC-DCF) which takes advantage of multi-channel assignment. The backoff algorithm of the IEEE 802.11 distributed coordination function (DCF) was modified to invoke channel switching, based on threshold criteria in order to improve the overall throughput for wireless sensor networks (WSNs) over 802.11 networks. We presented simulation experiments in order to investigate the characteristics of multi-channel communication in wireless sensor networks using an NS2 platform. Nodes only use a single radio and perform channel switching only after specified threshold is reached. Single radio can only work on one channel at any given time. All nodes initiate constant bit rate streams towards the receiving nodes. In this work, we studied the impact of non-overlapping channels in the 2.4 frequency band on: constant bit rate (CBR) streams, node density, source nodes sending data directly to sink and signal strength by varying distances between the sensor nodes and operating frequencies of the radios with different data rates. We showed that multi-channel enhancement using our proposed algorithm provides significant improvement in terms of throughput, packet delivery ratio and delay. This technique can be considered for WSNs future use in 802.11 networks especially when the IEEE 802.11n becomes popular thereby may prevent the 802.15.4 network from operating effectively in the 2.4 GHz frequency band.

Patterns of Recurrence in Electively Irradiated Lymph Node Regions After Definitive Accelerated Intensity Modulated Radiation Therapy for Head and Neck Squamous Cell Carcinoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bosch, Sven van den, E-mail: sven.vandenbosch@radboudumc.nl; Dijkema, Tim; Verhoef, Lia C.G.

Purpose: To provide a comprehensive risk assessment on the patterns of recurrence in electively irradiated lymph node regions after definitive radiation therapy for head and neck cancer. Methods and Materials: Two hundred sixty-four patients with stage cT2-4N0-2M0 squamous cell carcinoma of the oropharynx, larynx, or hypopharynx treated with accelerated intensity modulated radiation therapy between 2008 and 2012 were included. On the radiation therapy planning computed tomography (CT) scans from all patients, 1166 lymph nodes (short-axis diameter ≥5 mm) localized in the elective volume were identified and delineated. The exact sites of regional recurrences were reconstructed and projected on the initial radiationmore » therapy planning CT scan by performing coregistration with diagnostic imaging of the recurrence. Results: The actuarial rate of recurrence in electively irradiated lymph node regions at 2 years was 5.1% (95% confidence interval 2.4%-7.8%). Volumetric analysis showed an increased risk of recurrence with increasing nodal volume. Receiver operating characteristic analysis demonstrated that the summed long- and short-axis diameter is a good alternative for laborious volume calculations, using ≥17 mm as cut-off (hazard ratio 17.8; 95% confidence interval 5.7-55.1; P<.001). Conclusions: An important risk factor was identified that can help clinicians in the pretreatment risk assessment of borderline-sized lymph nodes. Not overtly pathologic nodes with a summed diameter ≥17 mm may require a higher than elective radiation therapy dose. For low-risk elective regions (all nodes <17 mm), the safety of dose de-escalation below the traditional 45 to 50 Gy should be investigated.« less

Multi-Channel Distributed Coordinated Function over Single Radio in Wireless Sensor Networks

PubMed Central

Campbell, Carlene E.-A.; Loo, Kok-Keong (Jonathan); Gemikonakli, Orhan; Khan, Shafiullah; Singh, Dhananjay

2011-01-01

Multi-channel assignments are becoming the solution of choice to improve performance in single radio for wireless networks. Multi-channel allows wireless networks to assign different channels to different nodes in real-time transmission. In this paper, we propose a new approach, Multi-channel Distributed Coordinated Function (MC-DCF) which takes advantage of multi-channel assignment. The backoff algorithm of the IEEE 802.11 distributed coordination function (DCF) was modified to invoke channel switching, based on threshold criteria in order to improve the overall throughput for wireless sensor networks (WSNs) over 802.11 networks. We presented simulation experiments in order to investigate the characteristics of multi-channel communication in wireless sensor networks using an NS2 platform. Nodes only use a single radio and perform channel switching only after specified threshold is reached. Single radio can only work on one channel at any given time. All nodes initiate constant bit rate streams towards the receiving nodes. In this work, we studied the impact of non-overlapping channels in the 2.4 frequency band on: constant bit rate (CBR) streams, node density, source nodes sending data directly to sink and signal strength by varying distances between the sensor nodes and operating frequencies of the radios with different data rates. We showed that multi-channel enhancement using our proposed algorithm provides significant improvement in terms of throughput, packet delivery ratio and delay. This technique can be considered for WSNs future use in 802.11 networks especially when the IEEE 802.11n becomes popular thereby may prevent the 802.15.4 network from operating effectively in the 2.4 GHz frequency band. PMID:22346614

Predictors of Nodal Upstaging in Clinical Node Negative Patients With Penile Carcinoma: A National Cancer Database Analysis.

PubMed

Winters, Brian R; Mossanen, Matthew; Holt, Sarah K; Lin, Daniel W; Wright, Jonathan L

2016-10-01

To examine the risk factors associated with upstaging at inguinal lymph node dissection (ILND) in men with penile cancer and clinically negative lymph nodes (cN0) using a large US cancer database. The National Cancer Data Base was queried from 1998 to 2012 to identify men with penile cancer who underwent ILND and had complete clinical or pathologic node status available. Lymphovascular invasion (LVI) was available after 2010. Multivariate logistic regression evaluated factors (cT stage, grade, LVI) associated with pathologic nodal upstaging in those with cN0 disease. Correlations between clinical and pathologic node status were also calculated with weighted kappa statistics. Complete clinical and pathologic LN status was available for 875 patients. Of these, 461 (53%) were cN0. Upstaging occurred in 111 (24%). When stratified by low, intermediate, and high-risk groups, the proportion with pathologically positive LNs was 16%, 20%, and 27%, respectively (P = .12). On multivariate analysis, limited to men with LVI data available (N = 206), LVI (odds ratio 3.10, 95% confidence interval 1.39-6.92), but not increasing stage (univariate only) or grade (univariate only), was significantly associated with upstaging at ILND. In this analysis, of 461 patients with node-negative penile cancer undergoing ILND, upstaging was observed in 24%. LVI was the strongest independent predictor of occult lymph node disease. These findings corroborate the presence of LVI as the significant risk factor for occult micrometastases and suggest a possible improvement in existing risk stratification groupings, with the presence of LVI, regardless of stage or grade, to be considered high-risk disease. Copyright © 2016 Elsevier Inc. All rights reserved.

Strategies for a better performance of RPL under mobility in wireless sensor networks

NASA Astrophysics Data System (ADS)

Latib, Z. A.; Jamil, A.; Alduais, N. A. M.; Abdullah, J.; Audah, L. H. M.; Alias, R.

2017-09-01

A Wireless Sensor Network (WSN) is usually stationary, which the network comprises of static nodes. The increase demand for mobility in various applications such as environmental monitoring, medical, home automation, and military, raises the question how IPv6 Routing Protocol for Low-Power and Lossy Networks (RPL) would perform under these mobility applications. This paper aims to understand performance of RPL and come out with strategies for a better performance of RPL in mobility scenarios. Because of this, this paper evaluates the performance of the RPL protocol under three different scenarios: sink and sensor nodes are static, static sink and mobile sensor nodes, and sink and sensor nodes are mobile. The network scenarios are implemented in Cooja simulator. A WSN consists of 25 sensor nodes and one sink node is configured in the simulation environment. The simulation is varied over different packet rates and ContikiMAC's Clear Channel Assessment (CCA) rate. As the performance metric, RPL is evaluated in term of packet delivery ratio (PDR), power consumption and packet rates. The simulation results show RPL provides a poor PDR in the mobility scenarios when compared to the static scenario. In addition, RPL consumes more power and increases duty-cycle rate to support mobility when compared to the static scenario. Based on the findings, we suggest three strategies for a better performance of RPL in mobility scenarios. First, RPL should operates at a lower packet rates when implemented in the mobility scenarios. Second, RPL should be implemented with a higher duty-cycle rate. Lastly, the sink node should be positioned as much as possible in the center of the mobile network.

p16-positive lymph node metastases from cutaneous head and neck squamous cell carcinoma: No association with high-risk human papillomavirus or prognosis and implications for the workup of the unknown primary.

PubMed

McDowell, Lachlan J; Young, Richard J; Johnston, Meredith L; Tan, Tze-Jian; Kleid, Stephen; Liu, Chen S; Bressel, Mathias; Estall, Vanessa; Rischin, Danny; Solomon, Benjamin; Corry, June

2016-04-15

The incidence of p16 overexpression and the role of human papillomavirus (HPV) in cutaneous head and neck squamous cell carcinoma (cHNSCC) are unclear. One hundred forty-three patients with cHNSCC lymph node metastases involving the parotid gland were evaluated for p16 expression by immunohistochemistry. The detection of 18 high-risk HPV subtypes was performed with HPV RNA in situ hybridization for a subset of 59 patients. The results were correlated with clinicopathological features and outcomes. The median follow-up time was 5.3 years. No differences were observed in clinicopathological factors with respect to the p16 status. p16 was positive, weak, and negative in 45 (31%), 21 (15%), and 77 cases (54%), respectively. No high-risk HPV subtypes were identified, regardless of the p16 status. The p16 status was not prognostic for overall (hazard ratio, 1.08; 95% confidence interval [CI], 0.85-1.36; P = .528), cancer-specific (hazard ratio, 1.12; 95% CI, 0.77-1.64; P = .542), or progression-free survival (hazard ratio, 1.03; 95% CI, 0.83-1.29; P = .783). Distant metastasis-free survival, freedom from locoregional failure, and freedom from local failure were also not significantly associated with the p16 status. p16 positivity is common but not prognostic in cHNSCC lymph node metastases. High-risk HPV subtypes are not associated with p16 positivity and do not appear to play a role in this disease. HPV testing, in addition to the p16 status in the unknown primary setting, may provide additional information for determining a putative primary site. © 2016 American Cancer Society.

Prognostic impact of number of resected and involved lymph nodes at complete resection on survival in non-small cell lung cancer.

PubMed

Saji, Hisashi; Tsuboi, Masahiro; Yoshida, Koichi; Kato, Yasufumi; Nomura, Masaharu; Matsubayashi, Jun; Nagao, Toshitaka; Kakihana, Masatoshi; Usuda, Jitsuo; Kajiwara, Naohiro; Ohira, Tatsuo; Ikeda, Norihiko

2011-11-01

Lymph node (LN) status is a major determinant of stage and survival in patients with lung cancer. In the 7th edition of the TNM Classification of Malignant Tumors, the number of involved LNs is included in the definition of pN factors in breast, stomach, esophageal, and colorectal cancer, and the pN status significantly correlates with prognosis. We retrospectively investigated the prognostic impact of the number of resected LNs (RLNs) and involved LNs in the context of other established clinical prognostic factors, in a series of 928 consecutive patients with non-small cell lung cancer (NSCLC) who underwent complete resection at our institution between 2000 and 2007. The mean number of RLNs was 15. There was a significant difference in the total number of RLNs categorized between less than 10 and ≥10 (p = 0.0129). Although the incidence of LN involvement was statistically associated with poor prognosis, the largest statistically significant increase in overall survival was observed between 0 to 3 and ≥4 involved LNs (hazard ratio = 7.680; 95% confidence interval = 5.051-11.655, p < 0.0001). On multivariate analysis, we used the ratio between the number of involved LNs and RLNs. The number of RLNs was found to be a strong independent prognostic factor for NSCLC (hazard ratio = 6.803; 95% confidence interval = 4.137-11.186, p < 0.0001). Complete resection including 10 or more LNs influenced survival at complete NSCLC resection. Four involved LNs seemed to be a benchmark for NSCLC prognosis. The number of involved LNs is a strong independent prognostic factor in NSCLC, and the results of this study may provide new information for determining the N category in the next tumor, node, metastasis classification.

Impact of smoking history on the outcomes of women with early-stage breast cancer: a secondary analysis of a randomized study.

PubMed

Abdel-Rahman, Omar; Cheung, Winson Y

2018-04-11

To assess the impact of smoking history on the outcomes of early-stage breast cancer patients treated with sequential anthracyclines-taxanes in a randomized study. This is a secondary analysis of patient-level data of 1242 breast cancer patients referred for adjuvant chemotherapy in the BCIRG005 clinical trial. Overall survival was assessed according to smoking history through Kaplan-Meier analysis. Univariate and multivariate Cox regression analyses of factors affecting overall and relapse-free survival were subsequently conducted. Factors that were evaluated included: age, performance status, number of chemotherapy cycles, T stage, lymph node ratio, estrogen receptor status, adjuvant radiotherapy and smoking history. Kaplan-Meier analysis of overall survival according to smoking status (ever smoker vs. never smoker) was conducted. There was a trend toward a better overall survival among never smokers compared to ever smokers; however, it was not statistically significant (P = 0.098). The following factors were associated with better overall survival in multivariate analysis: older age (P = 0.011), complete chemotherapy course (P = 0.002), lower T stage (P < 0.0001), lower lymph node ratio (P < 0.0001) and positive estrogen receptor status (P = 0.006). Otherwise, the following factors were associated with better relapse-free survival in multivariate analysis: older age (P = 0.001), never smoking status (P = 0.021), lower T stage (P = 0.028), lower lymph node ratio (P < 0.0001) and positive estrogen receptor status (P < 0.0001). Early-stage breast cancer patients with a positive smoking history experienced worse relapse-free survival compared to never smokers. Physicians managing breast cancer patients should prioritize discussion about the benefits of smoking cessation when counseling their patients.

Radiotherapy or surgery of the axilla after a positive sentinel node in breast cancer (EORTC 10981-22023 AMAROS):a randomised, multicentre, open-label, phase 3 non-inferiority trial

PubMed Central

Donker, Mila; van Tienhoven, Geertjan; Straver, Marieke E; Meijnen, Philip; van de Velde, Cornelis J H; Mansel, Robert E; Cataliotti, Luigi; Westenberg, A Helen; Klinkenbijl, Jean H G; Orzalesi, Lorenzo; Bouma, Willem H; van der Mijle, Huub C J; Nieuwenhuijzen, Grard A P; Veltkamp, Sanne C; Slaets, Leen; Duez, Nicole J; de Graaf, Peter W; van Dalen, Thijs; Marinelli, Andreas; Rijna, Herman; Snoj, Marko; Bundred, Nigel J; Merkus, Jos W S; Belkacemi, Yazid; Petignat, Patrick; Schinagl, Dominic A X; Coens, Corneel; Messina, Carlo G M; Bogaerts, Jan; Rutgers, Emiel J T

2014-01-01

Summary Background If treatment of the axilla is indicated in patients with breast cancer who have a positive sentinel node, axillary lymph node dissection is the present standard. Although axillary lymph node dissection provides excellent regional control, it is associated with harmful side-effects. We aimed to assess whether axillary radiotherapy provides comparable regional control with fewer side-effects. Methods Patients with T1–2 primary breast cancer and no palpable lymphadenopathy were enrolled in the randomised, multicentre, open-label, phase 3 non-inferiority EORTC 10981-22023 AMAROS trial. Patients were randomly assigned (1:1) by a computer-generated allocation schedule to receive either axillary lymph node dissection or axillary radiotherapy in case of a positive sentinel node, stratified by institution. The primary endpoint was non-inferiority of 5-year axillary recurrence, considered to be not more than 4% for the axillary radiotherapy group compared with an expected 2% in the axillary lymph node dissection group. Analyses were by intention to treat and per protocol. The AMAROS trial is registered with ClinicalTrials.gov, number NCT00014612. Findings Between Feb 19, 2001, and April 29, 2010, 4823 patients were enrolled at 34 centres from nine European countries, of whom 4806 were eligible for randomisation. 2402 patients were randomly assigned to receive axillary lymph node dissection and 2404 to receive axillary radiotherapy. Of the 1425 patients with a positive sentinel node, 744 had been randomly assigned to axillary lymph node dissection and 681 to axillary radiotherapy; these patients constituted the intention-to-treat population. Median follow-up was 6·1 years (IQR 4·1–8·0) for the patients with positive sentinel lymph nodes. In the axillary lymph node dissection group, 220 (33%) of 672 patients who underwent axillary lymph node dissection had additional positive nodes. Axillary recurrence occurred in four of 744 patients in the axillary lymph node dissection group and seven of 681 in the axillary radiotherapy group. 5-year axillary recurrence was 0·43% (95% CI 0·00–0·92) after axillary lymph node dissection versus 1·19% (0·31–2·08) after axillary radiotherapy. The planned non-inferiority test was underpowered because of the low number of events. The one-sided 95% CI for the underpowered non-inferiority test on the hazard ratio was 0·00–5·27, with a non-inferiority margin of 2. Lymphoedema in the ipsilateral arm was noted significantly more often after axillary lymph node dissection than after axillary radiotherapy at 1 year, 3 years, and 5 years. Interpretation Axillary lymph node dissection and axillary radiotherapy after a positive sentinel node provide excellent and comparable axillary control for patients with T1–2 primary breast cancer and no palpable lymphadenopathy. Axillary radiotherapy results in significantly less morbidity. Funding EORTC Charitable Trust. PMID:25439688

Case-only analyses of the associations between polymorphisms in the metastasis modifying genes BRMS1 and SIPA1 and breast tumor characteristics, lymph node metastasis, and survival

PubMed Central

Roberts, Michelle R.; Hong, Chi-Chen; Edge, Stephen B.; Yao, Song; Bshara, Wiam; Higgins, Michael J.; Freudenheim, Jo L.; Ambrosone, Christine B.

2013-01-01

Introduction Lymph node metastases and tumor characteristics predict breast cancer prognosis but correlate imperfectly with likelihood of metastatic relapse. Discovery of genetic polymorphisms affecting metastasis may improve identification of patients requiring aggressive adjuvant therapy to prevent recurrence. We investigated associations between several variants in the BRMS1 and SIPA1 metastasis-modifying genes and lymph node metastases, tumor subtype and grade, recurrence, disease-free survival and overall survival. Methods This cross-sectional and prospective prognostic analysis included 859 patients who received surgery for incident breast cancer at Roswell Park Cancer Institute, participated in the DataBank and BioRepository shared resource, and had DNA, clinical, and pathology data available for analysis. Genotyping for BRMS1 (rs11537993, rs3116068, and rs1052566) and SIPA1 (rs75894763, rs746429, rs3741378, and rs2306364) polymorphisms was performed using Sequenom® iPLEX Gold and Taqman® real-time PCR assays. Logistic and Cox proportional hazards regressions were used to estimate odds ratios (OR) and hazard ratios (HR), respectively. Results BRMS1 rs1052566 heterozygous individuals were more likely to have node positive tumors (OR=1.58, 95% CI 1.13-2.23), although there was no dose-response relationship, and those with at least one variant allele were less likely to have the luminal B subtype (AG+AA: OR=0.59, 95% CI 0.36-0.98). BRMS1 rs3116068 was associated with increased likelihood of having the luminal B and the HER2-enriched tumor subtype (Ptrend=0.03). Two SIPA1 SNPs, rs746429 and rs2306364, were associated with decreased risk of triple negative tumors (Ptrend=0.04 and 0.07, respectively). Presence of 8 or more risk alleles was associated with an increased likelihood of having a node positive tumor (OR=2.14, 95% CI 1.18-3.36, Ptrend = 0.002). There were no significant associations with survival. Conclusions Polymorphisms in metastasis-associated genes may be related to tumor characteristics and lymph node metastasis, but not survival. Future evaluation of metastasis modifying gene variants is necessary to better understand the biology of metastasis. PMID:23771732

Case-only analyses of the associations between polymorphisms in the metastasis-modifying genes BRMS1 and SIPA1 and breast tumor characteristics, lymph node metastasis, and survival.

PubMed

Roberts, Michelle R; Hong, Chi-Chen; Edge, Stephen B; Yao, Song; Bshara, Wiam; Higgins, Michael J; Freudenheim, Jo L; Ambrosone, Christine B

2013-06-01

Lymph node metastases and tumor characteristics predict breast cancer prognosis but correlate imperfectly with likelihood of metastatic relapse. Discovery of genetic polymorphisms affecting metastasis may improve identification of patients requiring aggressive adjuvant therapy to prevent recurrence. We investigated associations between several variants in the BRMS1 and SIPA1 metastasis-modifying genes and lymph node metastases, tumor subtype and grade, recurrence, disease-free survival, and overall survival. This cross-sectional and prospective prognostic analysis included 859 patients who received surgery for incident breast cancer at Roswell Park Cancer Institute, participated in the DataBank and BioRepository shared resource, and had DNA, clinical, and pathology data available for analysis. Genotyping for BRMS1 (rs11537993, rs3116068, and rs1052566) and SIPA1 (rs75894763, rs746429, rs3741378, and rs2306364) polymorphisms was performed using Sequenom(®) iPLEX Gold and Taqman(®) real-time PCR assays. Logistic and Cox proportional hazards regressions were used to estimate odds ratios (OR) and hazard ratios (HR), respectively. BRMS1 rs1052566 heterozygous individuals were more likely to have node-positive tumors (OR = 1.58, 95 % CI 1.13-2.23), although there was no dose-response relationship, and those with at least one variant allele were less likely to have the luminal B subtype (AG + AA: OR = 0.59, 95 % CI 0.36-0.98). BRMS1 rs3116068 was associated with increased likelihood of having the luminal B and the HER2-enriched tumor subtype (P trend = 0.03). Two SIPA1 SNPs, rs746429 and rs2306364, were associated with decreased risk of triple-negative tumors (P trend = 0.04 and 0.07, respectively). Presence of 8 or more risk alleles was associated with an increased likelihood of having a node-positive tumor (OR = 2.14, 95 % CI 1.18-3.36, P trend = 0.002). There were no significant associations with survival. Polymorphisms in metastasis-associated genes may be related to tumor characteristics and lymph node metastasis, but not survival. Future evaluation of metastasis-modifying gene variants is necessary to better understand the biology of metastasis.

The Effects of Hashimoto Thyroiditis on Lymph Node Metastases in Unifocal and Multifocal Papillary Thyroid Carcinoma

PubMed Central

Zhu, Feng; Shen, Yi Bin; Li, Fu Qiang; Fang, Yun; Hu, Liang; Wu, Yi Jun

2016-01-01

Abstract The purpose of this study was to investigate the risk factors for central and lateral neck lymph node metastases in papillary thyroid carcinoma (PTC) and multifocal papillary thyroid carcinoma (MPTC), particularly when associated with Hashimoto thyroiditis (HT). A retrospective analysis of 763 consecutive patients who underwent total thyroidectomy with bilateral central neck dissection in the First Affiliated Hospital, College of Medicine, Zhejiang University between October 2011 and October 2014 was conducted. All patients had formal histological diagnoses of HT. Multivariable logistic regression analysis was performed to identify risk factors of neck lymph node metastases. Our study identified 277 PTC patients with HT and showed comparatively low rates of central lymph node metastases (CLNM) compared with the PTC patients without HT (37.2% versus 54.7%, P < 0.001). There were no statistically significant differences in lateral lymph node metastases (LLNM) (P = 0.656). Neck lymph node metastases were histologically proven in 127 (45.8%) patients with PTC with HT, including 103 CLNM and 24 LLNM. There were no significant differences in LLNM between the MPTC-associated HT and classic MPTC cases; however, a significantly reduced risk of CLNM was observed in the MPTC-associated HT compared with the MPTC cases (35.7% versus 72.4%, respectively, P < 0.001). In the multivariate analysis, HT was identified as an independent alleviating factor for CLNM in all PTC patients (odds ratio, 0.369; 95% confidence interval (CI), 0.261 to 0.521; P < 0.001) and in MPTC patients (odds ratio, 0.227; 95% CI, 0.126–0.406; P < 0.001). A cut-off of thyroid peroxidase antibody >140 IU/mL was established as the most sensitive and specific level for the prediction of MPTC based on receiver operating characteristic curve analyses. Thyroid peroxidase antibody, age, tumor size, and multifocality exhibited the ability to predict CLNM in PTC with HT patients with an area under the curve of 81.1% based on a multivariate model. Hashimoto thyroiditis was associated with increased prevalences of multifocality and capsular invasion. In contrast, HT was associated with a reduced risk of CLNM in PTC and MPTC patients, which indicated a potential protective effect. We found that the prognostic prediction model was applicable for predicting multifocality and CLNM in PTC patients with HT. PMID:26871795

The Effects of Hashimoto Thyroiditis on Lymph Node Metastases in Unifocal and Multifocal Papillary Thyroid Carcinoma: A Retrospective Chinese Cohort Study.

PubMed

Zhu, Feng; Shen, Yi Bin; Li, Fu Qiang; Fang, Yun; Hu, Liang; Wu, Yi Jun

2016-02-01

The purpose of this study was to investigate the risk factors for central and lateral neck lymph node metastases in papillary thyroid carcinoma (PTC) and multifocal papillary thyroid carcinoma (MPTC), particularly when associated with Hashimoto thyroiditis (HT).A retrospective analysis of 763 consecutive patients who underwent total thyroidectomy with bilateral central neck dissection in the First Affiliated Hospital, College of Medicine, Zhejiang University between October 2011 and October 2014 was conducted. All patients had formal histological diagnoses of HT. Multivariable logistic regression analysis was performed to identify risk factors of neck lymph node metastases.Our study identified 277 PTC patients with HT and showed comparatively low rates of central lymph node metastases (CLNM) compared with the PTC patients without HT (37.2% versus 54.7%, P < 0.001). There were no statistically significant differences in lateral lymph node metastases (LLNM) (P = 0.656). Neck lymph node metastases were histologically proven in 127 (45.8%) patients with PTC with HT, including 103 CLNM and 24 LLNM. There were no significant differences in LLNM between the MPTC-associated HT and classic MPTC cases; however, a significantly reduced risk of CLNM was observed in the MPTC-associated HT compared with the MPTC cases (35.7% versus 72.4%, respectively, P < 0.001). In the multivariate analysis, HT was identified as an independent alleviating factor for CLNM in all PTC patients (odds ratio, 0.369; 95% confidence interval (CI), 0.261 to 0.521; P < 0.001) and in MPTC patients (odds ratio, 0.227; 95% CI, 0.126-0.406; P < 0.001). A cut-off of thyroid peroxidase antibody >140 IU/mL was established as the most sensitive and specific level for the prediction of MPTC based on receiver operating characteristic curve analyses. Thyroid peroxidase antibody, age, tumor size, and multifocality exhibited the ability to predict CLNM in PTC with HT patients with an area under the curve of 81.1% based on a multivariate model.Hashimoto thyroiditis was associated with increased prevalences of multifocality and capsular invasion. In contrast, HT was associated with a reduced risk of CLNM in PTC and MPTC patients, which indicated a potential protective effect. We found that the prognostic prediction model was applicable for predicting multifocality and CLNM in PTC patients with HT.

Adjuvant Pertuzumab and Trastuzumab in Early HER2-Positive Breast Cancer.

PubMed

von Minckwitz, Gunter; Procter, Marion; de Azambuja, Evandro; Zardavas, Dimitrios; Benyunes, Mark; Viale, Giuseppe; Suter, Thomas; Arahmani, Amal; Rouchet, Nathalie; Clark, Emma; Knott, Adam; Lang, Istvan; Levy, Christelle; Yardley, Denise A; Bines, Jose; Gelber, Richard D; Piccart, Martine; Baselga, Jose

2017-07-13

Pertuzumab increases the rate of pathological complete response in the preoperative context and increases overall survival among patients with metastatic disease when it is added to trastuzumab and chemotherapy for the treatment of human epidermal growth factor receptor 2 (HER2)-positive breast cancer. In this trial, we investigated whether pertuzumab, when added to adjuvant trastuzumab and chemotherapy, improves outcomes among patients with HER2-positive early breast cancer. We randomly assigned patients with node-positive or high-risk node-negative HER2-positive, operable breast cancer to receive either pertuzumab or placebo added to standard adjuvant chemotherapy plus 1 year of treatment with trastuzumab. We assumed a 3-year invasive-disease-free survival rate of 91.8% with pertuzumab and 89.2% with placebo. In the trial population, 63% of the patients who were randomly assigned to receive pertuzumab (2400 patients) or placebo (2405 patients) had node-positive disease and 36% had hormone-receptor-negative disease. Disease recurrence occurred in 171 patients (7.1%) in the pertuzumab group and 210 patients (8.7%) in the placebo group (hazard ratio, 0.81; 95% confidence interval [CI], 0.66 to 1.00; P=0.045). The estimates of the 3-year rates of invasive-disease-free survival were 94.1% in the pertuzumab group and 93.2% in the placebo group. In the cohort of patients with node-positive disease, the 3-year rate of invasive-disease-free survival was 92.0% in the pertuzumab group, as compared with 90.2% in the placebo group (hazard ratio for an invasive-disease event, 0.77; 95% CI, 0.62 to 0.96; P=0.02). In the cohort of patients with node-negative disease, the 3-year rate of invasive-disease-free survival was 97.5% in the pertuzumab group and 98.4% in the placebo group (hazard ratio for an invasive-disease event, 1.13; 95% CI, 0.68 to 1.86; P=0.64). Heart failure, cardiac death, and cardiac dysfunction were infrequent in both treatment groups. Diarrhea of grade 3 or higher occurred almost exclusively during chemotherapy and was more frequent with pertuzumab than with placebo (9.8% vs. 3.7%). Pertuzumab significantly improved the rates of invasive-disease-free survival among patients with HER2-positive, operable breast cancer when it was added to trastuzumab and chemotherapy. Diarrhea was more common with pertuzumab than with placebo. (Funded by F. Hoffmann-La Roche/Genentech; APHINITY ClinicalTrials.gov number, NCT01358877 .).

Automated classification and quantitative analysis of arterial and venous vessels in fundus images

NASA Astrophysics Data System (ADS)

Alam, Minhaj; Son, Taeyoon; Toslak, Devrim; Lim, Jennifer I.; Yao, Xincheng

2018-02-01

It is known that retinopathies may affect arteries and veins differently. Therefore, reliable differentiation of arteries and veins is essential for computer-aided analysis of fundus images. The purpose of this study is to validate one automated method for robust classification of arteries and veins (A-V) in digital fundus images. We combine optical density ratio (ODR) analysis and blood vessel tracking algorithm to classify arteries and veins. A matched filtering method is used to enhance retinal blood vessels. Bottom hat filtering and global thresholding are used to segment the vessel and skeleton individual blood vessels. The vessel tracking algorithm is used to locate the optic disk and to identify source nodes of blood vessels in optic disk area. Each node can be identified as vein or artery using ODR information. Using the source nodes as starting point, the whole vessel trace is then tracked and classified as vein or artery using vessel curvature and angle information. 50 color fundus images from diabetic retinopathy patients were used to test the algorithm. Sensitivity, specificity, and accuracy metrics were measured to assess the validity of the proposed classification method compared to ground truths created by two independent observers. The algorithm demonstrated 97.52% accuracy in identifying blood vessels as vein or artery. A quantitative analysis upon A-V classification showed that average A-V ratio of width for NPDR subjects with hypertension decreased significantly (43.13%).

A computational system for lattice QCD with overlap Dirac quarks

NASA Astrophysics Data System (ADS)

Chiu, Ting-Wai; Hsieh, Tung-Han; Huang, Chao-Hsi; Huang, Tsung-Ren

2003-05-01

We outline the essential features of a Linux PC cluster which is now being developed at National Taiwan University, and discuss how to optimize its hardware and software for lattice QCD with overlap Dirac quarks. At present, the cluster constitutes of 30 nodes, with each node consisting of one Pentium 4 processor (1.6/2.0 GHz), one Gbyte of PC800 RDRAM, one 40/80 Gbyte hard disk, and a network card. The speed of this system is estimated to be 30 Gflops, and its price/performance ratio is better than $1.0/Mflops for 64-bit (double precision) computations in quenched lattice QCD with overlap Dirac quarks.

Celiac Node Failure Patterns After Definitive Chemoradiation for Esophageal Cancer in the Modern Era

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amini, Arya; UC Irvine School of Medicine, Irvine, California; Xiao Lianchun

2012-06-01

Purpose: The celiac lymph node axis acts as a gateway for metastatic systemic spread. The need for prophylactic celiac nodal coverage in chemoradiation therapy for esophageal cancer is controversial. Given the improved ability to evaluate lymph node status before treatment via positron emission tomography (PET) and endoscopic ultrasound, we hypothesized that prophylactic celiac node irradiation may not be needed for patients with localized esophageal carcinoma. Methods and Materials: We reviewed the radiation treatment volumes for 131 patients who underwent definitive chemoradiation for esophageal cancer. Patients with celiac lymph node involvement at baseline were excluded. Median radiation dose was 50.4 Gy.more » The location of all celiac node failures was compared with the radiation treatment plan to determine whether the failures occurred within or outside the radiation treatment field. Results: At a median follow-up time of 52.6 months (95% CI 46.1-56.7 months), 6 of 60 patients (10%) without celiac node coverage had celiac nodal failure; in 5 of these patients, the failures represented the first site of recurrence. Of the 71 patients who had celiac coverage, only 5 patients (7%) had celiac region relapse. In multivariate analyses, having a pretreatment-to-post-treatment change in standardized uptake value on PET >52% (odds ratio [OR] 0.198, p = 0.0327) and having failure in the clinical target volume (OR 10.72, p = 0.001) were associated with risk of celiac region relapse. Of those without celiac coverage, the 6 patients that later developed celiac failure had a worse median overall survival time compared with the other 54 patients who did not fail (median overall survival time: 16.5 months vs. 31.5 months, p = 0.041). Acute and late toxicities were similar in both groups. Conclusions: Although celiac lymph node failures occur in approximately 1 of 10 patients, the lack of effective salvage treatments and subsequent low morbidity may justify prophylactic treatment in distal esophageal cancer patients.« less

A Markovian model of evolving world input-output network

PubMed Central

Isacchini, Giulio

2017-01-01

The initial theoretical connections between Leontief input-output models and Markov chains were established back in 1950s. However, considering the wide variety of mathematical properties of Markov chains, so far there has not been a full investigation of evolving world economic networks with Markov chain formalism. In this work, using the recently available world input-output database, we investigated the evolution of the world economic network from 1995 to 2011 through analysis of a time series of finite Markov chains. We assessed different aspects of this evolving system via different known properties of the Markov chains such as mixing time, Kemeny constant, steady state probabilities and perturbation analysis of the transition matrices. First, we showed how the time series of mixing times and Kemeny constants could be used as an aggregate index of globalization. Next, we focused on the steady state probabilities as a measure of structural power of the economies that are comparable to GDP shares of economies as the traditional index of economies welfare. Further, we introduced two measures of systemic risk, called systemic influence and systemic fragility, where the former is the ratio of number of influenced nodes to the total number of nodes, caused by a shock in the activity of a node, and the latter is based on the number of times a specific economic node is affected by a shock in the activity of any of the other nodes. Finally, focusing on Kemeny constant as a global indicator of monetary flow across the network, we showed that there is a paradoxical effect of a change in activity levels of economic nodes on the overall flow of the world economic network. While the economic slowdown of the majority of nodes with high structural power results to a slower average monetary flow over the network, there are some nodes, where their slowdowns improve the overall quality of the network in terms of connectivity and the average flow of the money. PMID:29065145

The AA genotype of the regulatory BCL2 promoter polymorphism ( 938C>A) is associated with a favorable outcome in lymph node negative invasive breast cancer patients.

PubMed

Bachmann, Hagen S; Otterbach, Friedrich; Callies, Rainer; Nückel, Holger; Bau, Maja; Schmid, Kurt W; Siffert, Winfried; Kimmig, Rainer

2007-10-01

Expression of the antiapoptotic and antiproliferative protein Bcl-2 has been repeatedly shown to be associated with better clinical outcome in breast cancer. We recently showed a novel regulatory (-938C>A) single-nucleotide polymorphism (SNP) in the inhibitory P2 BCL2 gene promoter generating significantly different BCL2 promoter activities. Paraffin-embedded neoplastic and nonneoplastic tissues from 274 patients (161 still alive after a follow-up period of at least 80 months) with primary unilateral invasive breast carcinoma were investigated. Bcl-2 expression of tumor cells was shown by immunohistochemistry; nonneoplastic tissues were used for genotyping. Both the Bcl-2 expression and the (-938C>A) genotypes were correlated with the patients' survival. Kaplan-Meier curves revealed a significant association of the AA genotype with increased survival (P = 0.030) in lymph node-negative breast cancer patients, whereas no genotype effect could be observed in lymph node-positive cases. Ten-year survival rates were 88.6% for the AA genotype, 78.4% for the AC genotype, and 65.8% for the CC genotype. Multivariable Cox regression identified the BCL2 (-938CC) genotype as an independent prognostic factor for cancer-related death in lymph node-negative breast carcinoma patients (hazard ratio, 3.59; P = 0.032). Immunohistochemical Bcl-2 expression was significantly associated with the clinical outcome of lymph node-positive but not of lymph node-negative breast cancer patients. In lymph node-negative cases, the (-938C>A) SNP was both significantly related with the immunohistochemically determined level of Bcl-2 expression (P = 0.044) and the survival of patients with Bcl-2-expressing carcinomas (P = 0.006). These results suggest the (-938C>A) polymorphism as a survival prognosticator as well as indicator of a high-risk group within patients with lymph node-negative breast cancer.

The Role of Energy Reservoirs in Distributed Computing: Manufacturing, Implementing, and Optimizing Energy Storage in Energy-Autonomous Sensor Nodes

NASA Astrophysics Data System (ADS)

Cowell, Martin Andrew

The world already hosts more internet connected devices than people, and that ratio is only increasing. These devices seamlessly integrate with peoples lives to collect rich data and give immediate feedback about complex systems from business, health care, transportation, and security. As every aspect of global economies integrate distributed computing into their industrial systems and these systems benefit from rich datasets. Managing the power demands of these distributed computers will be paramount to ensure the continued operation of these networks, and is elegantly addressed by including local energy harvesting and storage on a per-node basis. By replacing non-rechargeable batteries with energy harvesting, wireless sensor nodes will increase their lifetimes by an order of magnitude. This work investigates the coupling of high power energy storage with energy harvesting technologies to power wireless sensor nodes; with sections covering device manufacturing, system integration, and mathematical modeling. First we consider the energy storage mechanism of supercapacitors and batteries, and identify favorable characteristics in both reservoir types. We then discuss experimental methods used to manufacture high power supercapacitors in our labs. We go on to detail the integration of our fabricated devices with collaborating labs to create functional sensor node demonstrations. With the practical knowledge gained through in-lab manufacturing and system integration, we build mathematical models to aid in device and system design. First, we model the mechanism of energy storage in porous graphene supercapacitors to aid in component architecture optimization. We then model the operation of entire sensor nodes for the purpose of optimally sizing the energy harvesting and energy reservoir components. In consideration of deploying these sensor nodes in real-world environments, we model the operation of our energy harvesting and power management systems subject to spatially and temporally varying energy availability in order to understand sensor node reliability. Looking to the future, we see an opportunity for further research to implement machine learning algorithms to control the energy resources of distributed computing networks.

Adjuvant chemotherapy versus chemoradiotherapy for small cell lung cancer with lymph node metastasis: a retrospective observational study with use of a national database in Japan.

PubMed

Urushiyama, Hirokazu; Jo, Taisuke; Yasunaga, Hideo; Yamauchi, Yasuhiro; Matsui, Hiroki; Hasegawa, Wakae; Takeshima, Hideyuki; Hiraishi, Yoshihisa; Mitani, Akihisa; Fushimi, Kiyohide; Nagase, Takahide

2017-09-02

The optimal postoperative treatment strategy for small cell lung cancer (SCLC) remains unclear, especially in patients with lymph node metastasis. We aimed to compare the outcomes of patients with SCLC and lymph node metastasis treated with postoperative adjuvant chemotherapy or chemoradiotherapy. We retrospectively collected data on patients with postoperative SCLC diagnosed with N1 and N2 lymph node metastasis from the Diagnosis Procedure Combination database in Japan, between July 2010 and March 2015. We extracted data on patient age, sex, comorbidities, and TNM classification at lung surgery; operative procedures, chemotherapy drugs, and radiotherapy during hospitalization; and discharge status. Recurrence-free survival was compared between the chemotherapy and chemoradiotherapy groups using multivariable Cox regression analysis. Median recurrence-free survival was 1146 days (95% confidence interval [CI], 885-1407) in the chemotherapy group (n = 489) and 873 days (95% CI, 464-1282) in the chemoradiotherapy group (n = 75). There was no significant difference between these after adjusting for patient backgrounds (hazard ratio, 1.29; 95% CI, 0.91-1.84). There was no significant difference in recurrence-free survival between patients with SCLC and N1-2 lymph node metastasis treated with postoperative adjuvant chemotherapy and chemoradiotherapy. Further randomized clinical trials are needed to address this issue.

A grid matrix-based Raman spectroscopic method to characterize different cell milieu in biopsied axillary sentinel lymph nodes of breast cancer patients.

PubMed

Som, Dipasree; Tak, Megha; Setia, Mohit; Patil, Asawari; Sengupta, Amit; Chilakapati, C Murali Krishna; Srivastava, Anurag; Parmar, Vani; Nair, Nita; Sarin, Rajiv; Badwe, R

2016-01-01

Raman spectroscopy which is based upon inelastic scattering of photons has a potential to emerge as a noninvasive bedside in vivo or ex vivo molecular diagnostic tool. There is a need to improve the sensitivity and predictability of Raman spectroscopy. We developed a grid matrix-based tissue mapping protocol to acquire cellular-specific spectra that also involved digital microscopy for localizing malignant and lymphocytic cells in sentinel lymph node biopsy sample. Biosignals acquired from specific cellular milieu were subjected to an advanced supervised analytical method, i.e., cross-correlation and peak-to-peak ratio in addition to PCA and PC-LDA. We observed decreased spectral intensity as well as shift in the spectral peaks of amides and lipid bands in the completely metastatic (cancer cells) lymph nodes with high cellular density. Spectral library of normal lymphocytes and metastatic cancer cells created using the cellular specific mapping technique can be utilized to create an automated smart diagnostic tool for bench side screening of sampled lymph nodes. Spectral library of normal lymphocytes and metastatic cancer cells created using the cellular specific mapping technique can be utilized to develop an automated smart diagnostic tool for bench side screening of sampled lymph nodes supported by ongoing global research in developing better technology and signal and big data processing algorithms.

Quality assessment of lymph node sampling in rhabdomyosarcoma: A surveillance, epidemiology, and end results (SEER) program study.

PubMed

Lobeck, Inna; Dupree, Phylicia; Karns, Rebekah; Rodeberg, David; von Allmen, Daniel; Dasgupta, Roshni

2017-04-01

Lymph node sampling is integral in the management of extremity and paratesticular rhabdomyosarcoma (RMS). The aim of this study was to determine overall surgical compliance with treatment protocols and impact of nodal sampling outcomes in these tumors. A query of the surveillance, epidemiology, and end results program (SEER) database was performed from 2003 to 2008 for patients <19years of age with RMS. Data obtained included demographics, five-year survival and rate of nodal sampling. Analysis was performed utilizing chi-squared, Kaplan-Meier and hazard ratio modeling. Of 537 patients with extremity RMS, nodal sampling was performed in 25.7% (n=138). This lack of nodal sampling had a negative outcome on survival (p=0.004). Sixty five patients with paratesticular RMS aged greater than 10 were identified and also displayed low rates of lymph node sampling (47.7%, n=31). For paratesticular patients, a similar increase in survival was seen in patients who underwent nodal evaluation (p=0.024). Lymph node sampling is the standard of care in RMS. However, surgical compliance with treatment protocols is poor. Nodal evaluation correlated significantly with overall survival. These findings suggest a need for improved education among surgeons and oncologists regarding the need lymph node assessment in pediatric oncology patients. Evidence rating/classification: Prognosis study, Level III. Copyright © 2017 Elsevier Inc. All rights reserved.

Energy Efficient Cluster Based Scheduling Scheme for Wireless Sensor Networks

PubMed Central

Srie Vidhya Janani, E.; Ganesh Kumar, P.

2015-01-01

The energy utilization of sensor nodes in large scale wireless sensor network points out the crucial need for scalable and energy efficient clustering protocols. Since sensor nodes usually operate on batteries, the maximum utility of network is greatly dependent on ideal usage of energy leftover in these sensor nodes. In this paper, we propose an Energy Efficient Cluster Based Scheduling Scheme for wireless sensor networks that balances the sensor network lifetime and energy efficiency. In the first phase of our proposed scheme, cluster topology is discovered and cluster head is chosen based on remaining energy level. The cluster head monitors the network energy threshold value to identify the energy drain rate of all its cluster members. In the second phase, scheduling algorithm is presented to allocate time slots to cluster member data packets. Here congestion occurrence is totally avoided. In the third phase, energy consumption model is proposed to maintain maximum residual energy level across the network. Moreover, we also propose a new packet format which is given to all cluster member nodes. The simulation results prove that the proposed scheme greatly contributes to maximum network lifetime, high energy, reduced overhead, and maximum delivery ratio. PMID:26495417

Perpendicular STT_RAM cell in 8 nm technology node using Co1/Ni3(1 1 1)||Gr2||Co1/Ni3(1 1 1) structure as magnetic tunnel junction

NASA Astrophysics Data System (ADS)

Varghani, Ali; Peiravi, Ali; Moradi, Farshad

2018-04-01

The perpendicular anisotropy Spin-Transfer Torque Random Access Memory (P-STT-RAM) is considered to be a promising candidate for high-density memories. Many distinct advantages of Perpendicular Magnetic Tunnel Junction (P-MTJ) compared to the conventional in-plane MTJ (I-MTJ) such as lower switching current, circular cell shape that facilitates manufacturability in smaller technology nodes, large thermal stability, smaller cell size, and lower dipole field interaction between adjacent cells make it a promising candidate as a universal memory. However, for small MTJ cell sizes, the perpendicular technology requires new materials with high polarization and low damping factor as well as low resistance area product of a P-MTJ in order to avoid a high write voltage as technology is scaled down. A new graphene-based STT-RAM cell for 8 nm technology node that uses high perpendicular magnetic anisotropy cobalt/nickel (Co/Ni) multilayer as magnetic layers is proposed in this paper. The proposed junction benefits from enough Tunneling Magnetoresistance Ratio (TMR), low resistance area product, low write voltage, and low power consumption that make it suitable for 8 nm technology node.

An Effective Cuckoo Search Algorithm for Node Localization in Wireless Sensor Network.

PubMed

Cheng, Jing; Xia, Linyuan

2016-08-31

Localization is an essential requirement in the increasing prevalence of wireless sensor network (WSN) applications. Reducing the computational complexity, communication overhead in WSN localization is of paramount importance in order to prolong the lifetime of the energy-limited sensor nodes and improve localization performance. This paper proposes an effective Cuckoo Search (CS) algorithm for node localization. Based on the modification of step size, this approach enables the population to approach global optimal solution rapidly, and the fitness of each solution is employed to build mutation probability for avoiding local convergence. Further, the approach restricts the population in the certain range so that it can prevent the energy consumption caused by insignificant search. Extensive experiments were conducted to study the effects of parameters like anchor density, node density and communication range on the proposed algorithm with respect to average localization error and localization success ratio. In addition, a comparative study was conducted to realize the same localization task using the same network deployment. Experimental results prove that the proposed CS algorithm can not only increase convergence rate but also reduce average localization error compared with standard CS algorithm and Particle Swarm Optimization (PSO) algorithm.

An Effective Cuckoo Search Algorithm for Node Localization in Wireless Sensor Network

PubMed Central

Cheng, Jing; Xia, Linyuan

2016-01-01

Localization is an essential requirement in the increasing prevalence of wireless sensor network (WSN) applications. Reducing the computational complexity, communication overhead in WSN localization is of paramount importance in order to prolong the lifetime of the energy-limited sensor nodes and improve localization performance. This paper proposes an effective Cuckoo Search (CS) algorithm for node localization. Based on the modification of step size, this approach enables the population to approach global optimal solution rapidly, and the fitness of each solution is employed to build mutation probability for avoiding local convergence. Further, the approach restricts the population in the certain range so that it can prevent the energy consumption caused by insignificant search. Extensive experiments were conducted to study the effects of parameters like anchor density, node density and communication range on the proposed algorithm with respect to average localization error and localization success ratio. In addition, a comparative study was conducted to realize the same localization task using the same network deployment. Experimental results prove that the proposed CS algorithm can not only increase convergence rate but also reduce average localization error compared with standard CS algorithm and Particle Swarm Optimization (PSO) algorithm. PMID:27589756

High histologic grade and increased relative content of tryptophan in breast cancer using ratios from fingerprint fluorescence spectral peaks

NASA Astrophysics Data System (ADS)

Sordillo, Laura A.; Sordillo, Peter P.; Budansky, Yury; Pu, Yang; Alfano, R. R.

2015-03-01

Histologic grade is a very important, but underappreciated, parameter of breast cancer aggressiveness. Despite its importance, it has historically not been included as one of the criteria for staging of this cancer. In this study, spectral fluorescence profiles from patients with breast carcinoma were acquired. Ratios of emission peaks at 340 over 440,460 nm from biomolecules in malignant and normal samples were calculated. Cancerous over normal ratios (double ratio (DR) method) were evaluated with respect to tumor characteristics. Increased tryptophan content in breast cancer tissues correlates strongly with high grade, but not with lymph node metastases, estrogen receptor, progesterone receptor or Her-2-Neu receptor status.

Effect of Occult Metastases on Survival in Node-Negative Breast Cancer

PubMed Central

Weaver, Donald L.; Ashikaga, Takamaru; Krag, David N.; Skelly, Joan M.; Anderson, Stewart J.; Harlow, Seth P.; Julian, Thomas B.; Mamounas, Eleftherios P.; Wolmark, Norman

2011-01-01

BACKGROUND Retrospective and observational analyses suggest that occult lymph-node metastases are an important prognostic factor for disease recurrence or survival among patients with breast cancer. Prospective data on clinical outcomes from randomized trials according to sentinel-node involvement have been lacking. METHODS We randomly assigned women with breast cancer to sentinel-lymph-node biopsy plus axillary dissection or sentinel-lymph-node biopsy alone. Paraffin-embedded tissue blocks of sentinel lymph nodes obtained from patients with pathologically negative sentinel lymph nodes were centrally evaluated for occult metastases deeper in the blocks. Both routine staining and immunohistochemical staining for cytokeratin were used at two widely spaced additional tissue levels. Treating physicians were unaware of the findings, which were not used for clinical treatment decisions. The initial evaluation at participating sites was designed to detect all macrometastases larger than 2 mm in the greatest dimension. RESULTS Occult metastases were detected in 15.9% (95% confidence interval [CI], 14.7 to 17.1) of 3887 patients. Log-rank tests indicated a significant difference between patients in whom occult metastases were detected and those in whom no occult metastases were detected with respect to overall survival (P = 0.03), disease-free survival (P = 0.02), and distant-disease–free interval (P = 0.04). The corresponding adjusted hazard ratios for death, any outcome event, and distant disease were 1.40 (95% CI, 1.05 to 1.86), 1.31 (95% CI, 1.07 to 1.60), and 1.30 (95% CI, 1.02 to 1.66), respectively. Five-year Kaplan-Meier estimates of overall survival among patients in whom occult metastases were detected and those without detectable metastases were 94.6% and 95.8%, respectively. CONCLUSIONS Occult metastases were an independent prognostic variable in patients with sentinel nodes that were negative on initial examination; however, the magnitude of the difference in outcome at 5 years was small (1.2 percentage points). These data do not indicate a clinical benefit of additional evaluation, including immunohistochemical analysis, of initially negative sentinel nodes in patients with breast cancer. (Funded by the National Cancer Institute; ClinicalTrials.gov number, NCT00003830.) PMID:21247310

A Novel Risk Stratification to Predict Local-Regional Failures in Urothelial Carcinoma of the Bladder After Radical Cystectomy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baumann, Brian C.; Guzzo, Thomas J.; He Jiwei

2013-01-01

Purpose: Local-regional failures (LF) following radical cystectomy (RC) plus pelvic lymph node dissection (PLND) with or without chemotherapy for invasive urothelial bladder carcinoma are more common than previously reported. Adjuvant radiation therapy (RT) could reduce LF but currently has no defined role because of previously reported morbidity. Modern techniques with improved normal tissue sparing have rekindled interest in RT. We assessed the risk of LF and determined those factors that predict recurrence to facilitate patient selection for future adjuvant RT trials. Methods and Materials: From 1990-2008, 442 patients with urothelial bladder carcinoma at University of Pennsylvania were prospectively followed aftermore » RC plus PLND with or without chemotherapy with routine pelvic computed tomography (CT) or magnetic resonance imaging (MRI). One hundred thirty (29%) patients received chemotherapy. LF was any pelvic failure detected before or within 3 months of distant failure. Competing risk analyses identified factors predicting increased LF risk. Results: On univariate analysis, pathologic stage {>=}pT3, <10 nodes removed, positive margins, positive nodes, hydronephrosis, lymphovascular invasion, and mixed histology significantly predicted LF; node density was marginally predictive, but use of chemotherapy, number of positive nodes, type of surgical diversion, age, gender, race, smoking history, and body mass index were not. On multivariate analysis, only stage {>=}pT3 and <10 nodes removed were significant independent LF predictors with hazard ratios of 3.17 and 2.37, respectively (P<.01). Analysis identified 3 patient subgroups with significantly different LF risks: low-risk ({<=}pT2), intermediate-risk ({>=}pT3 and {>=}10 nodes removed), and high-risk ({>=}pT3 and <10 nodes) with 5-year LF rates of 8%, 23%, and 42%, respectively (P<.01). Conclusions: This series using routine CT and MRI surveillance to detect LF confirms that such failures are relatively common in cases of locally advanced disease and provides a rubric based on pathological stage and number of nodes removed that stratifies patients into 3 groups with significantly different LF risks to simplify patient selection for future adjuvant radiation therapy trials.« less

Comparative Efficacy and Safety of Adjuvant Letrozole Versus Anastrozole in Postmenopausal Patients With Hormone Receptor-Positive, Node-Positive Early Breast Cancer: Final Results of the Randomized Phase III Femara Versus Anastrozole Clinical Evaluation (FACE) Trial.

PubMed

Smith, Ian; Yardley, Denise; Burris, Howard; De Boer, Richard; Amadori, Dino; McIntyre, Kristi; Ejlertsen, Bent; Gnant, Michael; Jonat, Walter; Pritchard, Kathleen I; Dowsett, Mitch; Hart, Lowell; Poggio, Susan; Comarella, Lisa; Salomon, Herve; Wamil, Barbara; O'Shaughnessy, Joyce

2017-04-01

Purpose The Letrozole (Femara) Versus Anastrozole Clinical Evaluation (FACE) study compared the efficacy and safety of adjuvant letrozole versus anastrozole in postmenopausal patients with hormone receptor (HR) -positive and node-positive early breast cancer (eBC). Methods Postmenopausal women with HR-positive and node-positive eBC were randomly assigned to receive adjuvant therapy with either letrozole (2.5 mg) or anastrozole (1 mg) once per day for 5 years or until recurrence of disease. Patients were stratified on the basis of the number of lymph nodes and human epidermal growth factor receptor 2 status. The primary end point was 5-year disease-free survival (DFS), and the key secondary end points were overall survival and safety. Results A total of 4,136 patients were randomly assigned to receive either letrozole (n = 2,061) or anastrozole (n = 2,075). The final analysis was done at 709 DFS events (letrozole, 341 [16.5%]; anastrozole, 368 [17.7%]). The 5-year estimated DFS rate was 84.9% for letrozole versus 82.9% for anastrozole arm (hazard ratio, 0.93; 95% CI, 0.80 to 1.07; P = .3150). Exploratory analysis showed similar DFS with letrozole and anastrozole in all evaluated subgroups. The 5-year estimated overall survival rate was 89.9% for letrozole versus 89.2% for anastrozole arm (hazard ratio, 0.98; 95% CI, 0.82 to 1.17; P = .7916). Most common grade 3 to 4 adverse events (> 5% of patients) reported for letrozole versus anastrozole were arthralgia (3.9% v 3.3%, and 48.2% v 47.9% for all adverse events), hypertension (1.2% v 1.0%), hot flushes (0.8% v 0.4%), myalgia (0.8% v 0.7%), dyspnea (0.8% v 0.5%), and depression (0.8% v 0.6%). Conclusion Letrozole did not demonstrate significantly superior efficacy or safety compared with anastrozole in postmenopausal patients with HR-positive, node-positive eBC.

Preoperative tumor size at MRI predicts deep myometrial invasion, lymph node metastases, and patient outcome in endometrial carcinomas.

PubMed

Ytre-Hauge, Sigmund; Husby, Jenny A; Magnussen, Inger J; Werner, Henrica M J; Salvesen, Øyvind O; Bjørge, Line; Trovik, Jone; Stefansson, Ingunn M; Salvesen, Helga B; Haldorsen, Ingfrid S

2015-03-01

The aim of this study was to explore the relation between preoperative tumor size based on magnetic resonance imaging (MRI) and the surgical pathologic staging parameters (deep myometrial invasion, cervical stroma invasion, and metastatic lymph nodes) and to assess the prognostic impact of tumor size in endometrial carcinomas. Interobserver variability for the different tumor size measurements was also assessed. Preoperative pelvic MRI of 212 patients with histologically confirmed endometrial carcinomas was read independently by 3 radiologists. Maximum tumor diameters were measured in 3 orthogonal planes (anteroposterior, transverse, and craniocaudal planes [CC]), and tumor volumes were estimated. Tumor size was analyzed in relation to surgical staging results and patient survival. The multivariate analyses were adjusted for preoperative risk status based on endometrial biopsy. Intraclass correlation coefficients and receiver operating characteristics curves for the different tumor measurements were also calculated. Anteroposterior tumor diameter independently predicted deep myometrial invasion (P < 0.001), whereas CC tumor diameter tended to independently predict lymph node metastases (P = 0.06). Based on receiver operating characteristic curves, the following tumor size cutoff values were identified: anteroposterior diameter greater than 2 cm predicted deep myometrial invasion (unadjusted odds ratio [OR], 12.4; P < 0.001; adjusted OR, 6.7; P < 0.001) and CC diameter greater than 4 cm predicted lymph node metastases (unadjusted OR, 6.2; P < 0.001; adjusted OR, 4.9; P = 0.009). Large tumor size was associated with reduced progression/recurrence-free survival (P ≤ 0.005 for all size parameters), and CC diameter had an independent impact on survival (adjusted hazards ratio, 1.04; P = 0.009). The interobserver variability for the different size measurements was very low (intraclass correlation coefficient, 0.78-0.85). Anteroposterior tumor diameter greater than 2 cm predicts deep myometrial invasion, and CC tumor diameter greater than 4 cm predicts lymph node metastases. Tumor size is a strong prognostic factor in endometrial carcinomas. Preoperative tumor measurements based on MRI may potentially improve preoperative risk stratification models and thus enable better tailored surgical treatment in endometrial cancer.

Cooperative Opportunistic Pressure Based Routing for Underwater Wireless Sensor Networks.

PubMed

Javaid, Nadeem; Muhammad; Sher, Arshad; Abdul, Wadood; Niaz, Iftikhar Azim; Almogren, Ahmad; Alamri, Atif

2017-03-19

In this paper, three opportunistic pressure based routing techniques for underwater wireless sensor networks (UWSNs) are proposed. The first one is the cooperative opportunistic pressure based routing protocol (Co-Hydrocast), second technique is the improved Hydrocast (improved-Hydrocast), and third one is the cooperative improved Hydrocast (Co-improved Hydrocast). In order to minimize lengthy routing paths between the source and the destination and to avoid void holes at the sparse networks, sensor nodes are deployed at different strategic locations. The deployment of sensor nodes at strategic locations assure the maximum monitoring of the network field. To conserve the energy consumption and minimize the number of hops, greedy algorithm is used to transmit data packets from the source to the destination. Moreover, the opportunistic routing is also exploited to avoid void regions by making backward transmissions to find reliable path towards the destination in the network. The relay cooperation mechanism is used for reliable data packet delivery, when signal to noise ratio (SNR) of the received signal is not within the predefined threshold then the maximal ratio combining (MRC) is used as a diversity technique to improve the SNR of the received signals at the destination. Extensive simulations validate that our schemes perform better in terms of packet delivery ratio and energy consumption than the existing technique; Hydrocast.

Cooperative Opportunistic Pressure Based Routing for Underwater Wireless Sensor Networks

PubMed Central

Javaid, Nadeem; Muhammad; Sher, Arshad; Abdul, Wadood; Niaz, Iftikhar Azim; Almogren, Ahmad; Alamri, Atif

2017-01-01

In this paper, three opportunistic pressure based routing techniques for underwater wireless sensor networks (UWSNs) are proposed. The first one is the cooperative opportunistic pressure based routing protocol (Co-Hydrocast), second technique is the improved Hydrocast (improved-Hydrocast), and third one is the cooperative improved Hydrocast (Co-improved Hydrocast). In order to minimize lengthy routing paths between the source and the destination and to avoid void holes at the sparse networks, sensor nodes are deployed at different strategic locations. The deployment of sensor nodes at strategic locations assure the maximum monitoring of the network field. To conserve the energy consumption and minimize the number of hops, greedy algorithm is used to transmit data packets from the source to the destination. Moreover, the opportunistic routing is also exploited to avoid void regions by making backward transmissions to find reliable path towards the destination in the network. The relay cooperation mechanism is used for reliable data packet delivery, when signal to noise ratio (SNR) of the received signal is not within the predefined threshold then the maximal ratio combining (MRC) is used as a diversity technique to improve the SNR of the received signals at the destination. Extensive simulations validate that our schemes perform better in terms of packet delivery ratio and energy consumption than the existing technique; Hydrocast. PMID:28335494

Laser interference microscopy: a novel approach to the visualization of structural changes in myelin during the propagation of nerve impulses

NASA Astrophysics Data System (ADS)

Yusipovich, A. I.; Cherkashin, A. A.; Verdiyan, E. E.; Sogomonyan, I. A.; Maksimov, G. V.

2016-08-01

We used 3D phase images obtained by laser interference microscopy (LIM) for ex vivo evaluation of changes in the structure of myelin during repetitive stimulation. In this work we propose a simple model of myelinated nerve fiber (mNF), which describes phase images as a result of different geometry and membrane-to-cytoplasm ratio in various regions, particularly, the internode and paranodal-nodal-paranodal region, including the node of Ranvier. Application of this model provides clear interpretation of the phase images and also demonstrates that repetitive action potentials are accompanied by structural changes in myelin in the internode and cytoplasmic modification in the node of Ranvier. The first 20 min of stimulation did not induce significant changes in the measured parameters, but then the optical path difference at the periphery of mNF and at the node of Ranvier declined reversibly. We believe that our model is also applicable to other modifications of interference and non-interference imaging.

An efficient coordination protocol for wireless sensor networks

NASA Astrophysics Data System (ADS)

Paruchuri, Vamsi; Durresi, Arjan; Durresi, Mimoza; Barolli, Leonard

2005-10-01

Backbones infrastructures in wireless sensor networks reduce the communication overhead and energy consumption. In this paper, we present BackBone Routing (BBR), a fully distributed protocol for construction and rotation of backbone networks. BBR reduces energy consumption without significantly diminishing the capacity or connectivity of the network. Another key feature of BBR is its energy balancing nature by distributing the role of being Backbone Node among all the nodes. BBR builds on the observation that when a region of a shared-channel wireless network has a sufficient density of nodes, only a small number of them need be on at any time to forward traffic for active connections. Improvement in system lifetime due to BBR increases as the ratio of idle-to-sleep energy consumption increases, and increases as the density of the network increases. Our experiments show that BBR is more efficient in saving energy and extending network life without deteriorating network performance when compared with geographical shortest path routing.

Adaptive Reliable Routing Protocol Using Combined Link Stability Estimation for Mobile Ad hoc Networks

NASA Astrophysics Data System (ADS)

Vadivel, R.; Bhaskaran, V. Murali

2010-10-01

The main reason for packet loss in ad hoc networks is the link failure or node failure. In order to increase the path stability, it is essential to distinguish and moderate the failures. By knowing individual link stability along a path, path stability can be identified. In this paper, we develop an adaptive reliable routing protocol using combined link stability estimation for mobile ad hoc networks. The main objective of this protocol is to determine a Quality of Service (QoS) path along with prolonging the network life time and to reduce the packet loss. We calculate a combined metric for a path based on the parameters Link Expiration Time, Node Remaining Energy and Node Velocity and received signal strength to predict the link stability or lifetime. Then, a bypass route is established to retransmit the lost data, when a link failure occurs. By simulation results, we show that the proposed reliable routing protocol achieves high delivery ratio with reduced delay and packet drop.

Receiver-Based Ad Hoc On Demand Multipath Routing Protocol for Mobile Ad Hoc Networks

PubMed Central

Al-Nahari, Abdulaziz; Mohamad, Mohd Murtadha

2016-01-01

Decreasing the route rediscovery time process in reactive routing protocols is challenging in mobile ad hoc networks. Links between nodes are continuously established and broken because of the characteristics of the network. Finding multiple routes to increase the reliability is also important but requires a fast update, especially in high traffic load and high mobility where paths can be broken as well. The sender node keeps re-establishing path discovery to find new paths, which makes for long time delay. In this paper we propose an improved multipath routing protocol, called Receiver-based ad hoc on demand multipath routing protocol (RB-AOMDV), which takes advantage of the reliability of the state of the art ad hoc on demand multipath distance vector (AOMDV) protocol with less re-established discovery time. The receiver node assumes the role of discovering paths when finding data packets that have not been received after a period of time. Simulation results show the delay and delivery ratio performances are improved compared with AOMDV. PMID:27258013

Resource-Efficient, Hierarchical Auto-Tuning of a Hybrid Lattice Boltzmann Computation on the Cray XT4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Computational Research Division, Lawrence Berkeley National Laboratory; NERSC, Lawrence Berkeley National Laboratory; Computer Science Department, University of California, Berkeley

2009-05-04

We apply auto-tuning to a hybrid MPI-pthreads lattice Boltzmann computation running on the Cray XT4 at National Energy Research Scientific Computing Center (NERSC). Previous work showed that multicore-specific auto-tuning can improve the performance of lattice Boltzmann magnetohydrodynamics (LBMHD) by a factor of 4x when running on dual- and quad-core Opteron dual-socket SMPs. We extend these studies to the distributed memory arena via a hybrid MPI/pthreads implementation. In addition to conventional auto-tuning at the local SMP node, we tune at the message-passing level to determine the optimal aspect ratio as well as the correct balance between MPI tasks and threads permore » MPI task. Our study presents a detailed performance analysis when moving along an isocurve of constant hardware usage: fixed total memory, total cores, and total nodes. Overall, our work points to approaches for improving intra- and inter-node efficiency on large-scale multicore systems for demanding scientific applications.« less

Receiver-Based Ad Hoc On Demand Multipath Routing Protocol for Mobile Ad Hoc Networks.

PubMed

Al-Nahari, Abdulaziz; Mohamad, Mohd Murtadha

2016-01-01

Decreasing the route rediscovery time process in reactive routing protocols is challenging in mobile ad hoc networks. Links between nodes are continuously established and broken because of the characteristics of the network. Finding multiple routes to increase the reliability is also important but requires a fast update, especially in high traffic load and high mobility where paths can be broken as well. The sender node keeps re-establishing path discovery to find new paths, which makes for long time delay. In this paper we propose an improved multipath routing protocol, called Receiver-based ad hoc on demand multipath routing protocol (RB-AOMDV), which takes advantage of the reliability of the state of the art ad hoc on demand multipath distance vector (AOMDV) protocol with less re-established discovery time. The receiver node assumes the role of discovering paths when finding data packets that have not been received after a period of time. Simulation results show the delay and delivery ratio performances are improved compared with AOMDV.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaplan, W.D.; Piez, C.W.; Gelman, R.S.

Recent qualitative studies suggest that a micro Tc-99m sulfur colloid (..mu..SC) offers clinically acceptable images of the lymphatic system following intradermal injection. The authors have prospectively compared ..mu..SC to Tc-99m antimony colloid (SbS), the current agent of choice, in patients (pts) undergoing internal mammary lymphoscintigraphy. Twenty-eight consecutive females from 32-76 yrs of age were studied; 14 received SbS and 14 received ..mu..SC, (1.0 mCi, subcostal in posterior rectus sheath). Images (gamma camera and computer) of the injection site, anterior thorax and a Co-57 standard at the sternal notch were obtained at time 0 and 3 hrs after injection. The differencemore » in X-bar% lymph node uptake was not statistically significant for the two groups. The clinical information obtained with the two radiocolloids was similar with respect to number of nodes seen, migration and relative ''brightness'' (ratio-node/Co-57). Additional patient studies will be needed to confirm this observation.« less

Hardware and software status of QCDOC

NASA Astrophysics Data System (ADS)

Boyle, P. A.; Chen, D.; Christ, N. H.; Clark, M.; Cohen, S. D.; Cristian, C.; Dong, Z.; Gara, A.; Joó, B.; Jung, C.; Kim, C.; Levkova, L.; Liao, X.; Liu, G.; Mawhinney, R. D.; Ohta, S.; Petrov, K.; Wettig, T.; Yamaguchi, A.

2004-03-01

QCDOC is a massively parallel supercomputer whose processing nodes are based on an application-specific integrated circuit (ASIC). This ASIC was custom-designed so that crucial lattice QCD kernels achieve an overall sustained performance of 50% on machines with several 10,000 nodes. This strong scalability, together with low power consumption and a price/performance ratio of $1 per sustained MFlops, enable QCDOC to attack the most demanding lattice QCD problems. The first ASICs became available in June of 2003, and the testing performed so far has shown all systems functioning according to specification. We review the hardware and software status of QCDOC and present performance figures obtained in real hardware as well as in simulation.

Effects of oxygen-augmented atmosphere on the immune response.

NASA Technical Reports Server (NTRS)

Guttman, H. N.

1973-01-01

Antibovine serum albumin antibody and nonspecific protein production was evaluated in female rabbits (11-14.5 kg) housed in special cages ventilated with 20% or 40% oxygen at normal barometric pressure. Animals exposed to 40% oxygen do not show normal steady increase of serum antibody. Instead, their titers show a pattern of undershoot, overshoot, undershoot, and finally equilibration at a subnormal level; they have a depressed popliteal node polysome level and have an abnormally low proportion of membrane-bound polysomes. They also show reduced capability of popliteal nodes to synthesize protein (as expected from the reduced number of polysomes). However, the ratio of newly-synthesized specific antibody: nonspecific protein remains normal.

Investigating Associations Between Proliferation Indices, C-kit, and Lymph Node Stage in Canine Mast Cell Tumors.

PubMed

Krick, Erika Lauren; Kiupel, Matti; Durham, Amy C; Thaiwong, Tuddow; Brown, Dorothy C; Sorenmo, Karin U

Previous studies have evaluated cellular proliferation indices, KIT expression, and c-kit mutations to predict the clinical behavior of canine mast cell tumors (MCTs). The study purpose was to retrospectively compare mitotic index, argyrophilic nucleolar organizer regions (AgNORs)/nucleus, Ki-67 index, KIT labeling pattern, and internal tandem duplication mutations in c-KIT between stage I and stage II grade II MCTs. Medical records and tumor biopsy samples from dogs with Grade II MCTs with cytological or histopathological regional lymph node evaluation were included. Signalment, tumor location and stage, and presence of a recurrent versus de novo tumor were recorded. Mitotic index, AgNORs/nucleus, Ki-67, KIT staining pattern, and internal tandem duplication mutations in exon 11 of c-KIT were evaluated. Sixty-six tumors (51 stage I; 15 stage II) were included. Only AgNORs/nucleus and recurrent tumors were significantly associated with stage (odds ratio 2.8, 95% confidence interval [CI] 1.0-8.0, P = .049; odds ratio 8.8, 95% CI 1.1-69.5; P = .039). Receiver-operator characteristic analysis showed that the sensitivity and specificity of AgNORs/cell ≥ 1.87 were 93.3% and 27.4%, respectively, (area under the curve: 0.65) for predicting stage. Recurrent tumors and higher AgNORs/nucleus are associated with stage II grade II MCTs; however, an AgNOR cutoff value that reliably predicts lymph node metastasis was not determined.

Effects of irradiation combined with cis-diamminedichloroplatinum (CDDP) suppository in rabbit VX2 rectal tumors.

PubMed

Wakatsuki, Kazuo; Oda, Kenji; Koda, Keiji; Seike, Kazuhiro; Takiguchi, Nobuhiro; Saito, Norio; Miyazaki, Masaru

2005-03-01

To decrease local recurrence and increase disease free survival, various preoperative therapies for patients with advanced rectal cancer have been studied. Cis-diamminedichloroplatinum (II) (CDDP) has become one of the most widely used cancer chemotherapeutic drugs. It has also been found to have radiosensitizing properties. In this experimental study, the efficacy of chemoradiotherapy using a novel CDDP suppository, and one with mixed micelles, was examined in a rabbit VX2 rectal tumor model. Rabbits were divided into four groups: control group, irradiation (R) group, CDDP suppository plus irradiation (CR) group, and mixed micelles plus CDDP suppository plus irradiation (CMR) group. Tumor growth ratios were reduced significantly in the CR and CMR groups as compared with the ratio in the control group. Microscopically, response rates of main tumors were 0%, 33.3%, 70.0%, and 91. 7%, respectively. The number of metastatic lymph nodes in the CR and CMR groups decreased significantly compared to the control group and the R group. The microscopic response rates of metastatic lymph nodes were 0%, 11.1%, 40.0%, and 41.7%, respectively. Lung metastases were observed in three rabbits in the R group, and in one rabbit in the CMR group. Tissue platinum concentrations both in tumors and in regional lymph nodes increased significantly when mixed micelles were used. Chemoradiotherapy using the CDDP suppository and mixed micelles was effective for local control in the rabbit VX2 rectal tumor model.

DO PROXIMAL AND DISTAL GASTRIC TUMOURS BEHAVE DIFFERENTLY?

PubMed Central

da COSTA, Laurence Bedin; TONETO, Marcelo Garcia; MOREIRA, Luis Fernando

2016-01-01

ABSTRACT Background: Although the incidence of gastric (adenocarcinoma) cancer has been decreasing over time, it is still one of the most common malignancies worldwide, and proximal tumours tend to have a worse prognosis. Aim: To compare surgical outcomes and prognosis between proximal - excluding tumours of the cardia - and distal gastric cancer. Methods: Out of 293 cases reviewed - 209 with distal and 69 with proximal gastric cancer - were compared for clinical and pathological features, stage, surgical outcome, mortality and survival. Results: Statistically, there was no significant difference between patients in both groups regarding mortality (p=0.661), adjuvant chemotherapy (p 0.661), and radiation (p=1.000). However, there was significant difference in the degree of lymph node dissection employed (p=0.002) and the number of positive lymph nodes resected (p=0.038) between the two groups. The odds of death at five years for patients who had a D0 dissection was three times greater (odds ratio 2.78; (95%CI 1.33-5.82) than that for patients who had a D2 dissection, while for patients who had a D1 dissection the odds ratio was only 1.41 (95%CI 0.71-2.83) compared to D2-dissected patients. Conclusion: Although no significant differences were found between proximal and distal gastric cancer, the increased risk of death in D0- and D1-dissected patients clearly suggests an important role of radical D2 lymph node dissection in survival. PMID:28076476

Combining antiangiogenic therapy with neoadjuvant chemotherapy increases treatment efficacy in stage IIIA (N2) non-small cell lung cancer without increasing adverse effects.

PubMed

Zhao, Xiaoliang; Su, Yanjun; You, Jian; Gong, Liqun; Zhang, Zhenfa; Wang, Meng; Zhao, Zhenqing; Zhang, Zhen; Li, Xiaolin; Wang, Changli

2016-09-20

To evaluate the safety and efficacy of combining Endostar antiangiogenic therapy with neoadjuvant chemotherapy for the treatment of stage IIIA (N2) NSCLC, we conducted a randomized, controlled, open-label clinical study of 30 NSCLC patients. Patients were randomly assigned to the test or control groups, which received either two cycles of an NP neoadjuvant chemotherapy regimen combined with Endostar or the NP regimen alone, respectively, at a 2:1 ratio. Efficacy was assessed after 3 weeks, and surgical resection occurred within 4 weeks, in the 26 patients who successfully completed treatment. While total response rates (RR) and clinical benefit rates (CBR) did not differ between the experimental groups, total tumor regression rates (TRR) were higher in the test group than in the control group. Median DFS and OS also did not differ between the test and control groups. Clinical perioperative indicators, including intraoperative blood loss, number of dissected lymph node groups, duration of postoperative indwelling catheter use, and time to postoperative discharge, were comparable in the test and control groups. Finally, hematological and non-hematological toxicities and postoperative pathological indicators, including down-staging ratio, complete resection ratio, and metastatic lymph node ratio, also did not differ between the groups. Overall, combining Endostar with NP neoadjuvant chemotherapy increased therapeutic efficacy without increasing adverse effects in stage IIIA-N2 NSCLC patients. This study is registered with ClinicalTrials.gov (number NCT02497118).

LBMR: Load-Balanced Multipath Routing for Wireless Data-Intensive Transmission in Real-Time Medical Monitoring.

PubMed

Tseng, Chinyang Henry

2016-05-31

In wireless networks, low-power Zigbee is an excellent network solution for wireless medical monitoring systems. Medical monitoring generally involves transmission of a large amount of data and easily causes bottleneck problems. Although Zigbee's AODV mesh routing provides extensible multi-hop data transmission to extend network coverage, it originally does not, and needs to support some form of load balancing mechanism to avoid bottlenecks. To guarantee a more reliable multi-hop data transmission for life-critical medical applications, we have developed a multipath solution, called Load-Balanced Multipath Routing (LBMR) to replace Zigbee's routing mechanism. LBMR consists of three main parts: Layer Routing Construction (LRC), a Load Estimation Algorithm (LEA), and a Route Maintenance (RM) mechanism. LRC assigns nodes into different layers based on the node's distance to the medical data gateway. Nodes can have multiple next-hops delivering medical data toward the gateway. All neighboring layer-nodes exchange flow information containing current load, which is the used by the LEA to estimate future load of next-hops to the gateway. With LBMR, nodes can choose the neighbors with the least load as the next-hops and thus can achieve load balancing and avoid bottlenecks. Furthermore, RM can detect route failures in real-time and perform route redirection to ensure routing robustness. Since LRC and LEA prevent bottlenecks while RM ensures routing fault tolerance, LBMR provides a highly reliable routing service for medical monitoring. To evaluate these accomplishments, we compare LBMR with Zigbee's AODV and another multipath protocol, AOMDV. The simulation results demonstrate LBMR achieves better load balancing, less unreachable nodes, and better packet delivery ratio than either AODV or AOMDV.

Optical see-through cancer vision goggles enable direct patient visualization and real-time fluorescence-guided oncologic surgery

PubMed Central

Mondal, Suman B.; Gao, Shengkui; Zhu, Nan; Hebimana-Griffin, LeMoyne; Akers, Walter J.; Liang, Rongguang; Gruev, Viktor; Margenthaler, Julie; Achilefu, Samuel

2017-01-01

Background The inability to directly visualize the patient and surgical site limits the use of current near infrared fluorescence-guided surgery systems for real-time sentinel lymph node biopsy and tumor margin assessment. Methods We evaluated an optical see-through goggle augmented imaging and navigation system (GAINS) for near-infrared fluorescence-guided surgery. Tumor-bearing mice injected with a near infrared cancer-targeting agent underwent fluorescence-guided tumor resection. Female Yorkshire pigs received hind leg intradermal indocyanine green injection and underwent fluorescence-guided popliteal lymph node resection. Four breast cancer patients received 99mTc-sulfur colloid and indocyanine green retroareolarly, before undergoing sentinel lymph node biopsy using radioactive tracking and fluorescence imaging. Three other breast cancer patients received indocyanine green retroareolarly before undergoing standard-of-care partial mastectomy, followed by fluorescence imaging of resected tumor and tumor cavity for margin assessment. Results Using near-infrared fluorescence from the dyes, the optical see-through GAINS accurately identified all mouse tumors, pig lymphatics, and 4 pig popliteal lymph nodes with high signal-to-background ratio. In 4 human breast cancer patients, 11 sentinel lymph nodes were identified with a detection sensitivity of 86.67± 0.27% for radioactive tracking and 100% for GAINS. Tumor margin status was accurately predicted by GAINS in all three patients, including clear margins in patients 1 and 2 and positive margins in patient 3 as confirmed by paraffin embedded section histopathology. Conclusions The optical see-through GAINS prototype enhances near infrared fluorescence-guided surgery for sentinel lymph node biopsy and tumor margin assessment in breast cancer patients without disrupting the surgical workflow in the operating room. PMID:28213790

Clinical and economic outcomes associated with adjuvant chemotherapy in elderly patients with early stage operable breast cancer.

PubMed

Sail, Kavita R; Franzini, Luisa; Lairson, David R; Du, Xianglin L

2012-01-01

Breast cancer poses a huge medical burden to the U.S. health-care system, and chemotherapy is an important contributor to cancer costs. This article examines the differences between breast cancer patients who received chemotherapy and those who did not in costs and survival by age, treatment, and axillary node status. We studied a cohort of 23,110 node-positive and 31,572 node-negative women aged 65 years and older diagnosed with incident American Joint Committee on Cancer stage I, II, or IIIA breast cancer between January 1, 1991, and December 31, 2002, using Surveillance Epidemiology and End Results-Medicare data. Total treatment costs and costs associated with the use of chemotherapy were estimated by using the phase-of-care approach. The phase-specific costs were combined to estimate total Medicare payments for cancer care from diagnosis to death. Cox proportional hazard ratio of mortality was used to determine the effectiveness of adjuvant chemotherapy after adjusting for selected patient and tumor characteristics. We used propensity scores to minimize the bias associated with the receipt of adjuvant chemotherapy. Regression-adjusted difference in the average lifetime cost estimates for all node-positive patients receiving chemotherapy was approximately $2438 and was significantly higher (P < 0.05) than for patients not receiving chemotherapy. Mortality was significantly lower in node-positive and node-negative women aged 65 to 74 years receiving chemotherapy. Decision makers can use cost and effectiveness estimates from this study to assess the relative value of chemotherapy in different age groups. Copyright © 2012 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Nonsentinel lymph node status in patients with cutaneous melanoma: results from a multi-institution prognostic study.

PubMed

Pasquali, Sandro; Mocellin, Simone; Mozzillo, Nicola; Maurichi, Andrea; Quaglino, Pietro; Borgognoni, Lorenzo; Solari, Nicola; Piazzalunga, Dario; Mascheroni, Luigi; Giudice, Giuseppe; Patuzzo, Roberto; Caracò, Corrado; Ribero, Simone; Marone, Ugo; Santinami, Mario; Rossi, Carlo Riccardo

2014-03-20

We investigated whether the nonsentinel lymph node (NSLN) status in patients with melanoma improves the prognostic accuracy of common staging features; then we formulated a proposal for including the NSLN status in the current melanoma staging system. We retrospectively collected the clinicopathologic data of 1,538 patients with positive SLN status who underwent completion lymph node dissection (CLND) at nine Italian centers. Multivariable Cox regression survival analysis was used to identify independent prognostic factors. Literature meta-analysis was used to summarize the available evidence on the prognostic value of the NSLN status in patients with positive SLN. NSLN metastasis was observed in 353 patients (23%). After a median follow-up of 45 months, NSLN status was an independent prognostic factor for melanoma-specific survival (hazard ratio [HR] = 1.34; 95% CI, 1.18 to 1.52; P < .001). NSLN status efficiently stratified the prognosis of patients with two to three positive lymph nodes (n = 387; HR = 1.39; 95% CI, 1.07 to 1.81; P = .013), independently of other staging features. Searching the literature, this patient subgroup was investigated in other two studies. Pooling the results (n = 620 patients; 284 NSLN negative and 336 NSLN positive), we found that NSLN status is a highly significant prognostic factor (summary HR = 1.59; 95% CI, 1.27 to 1.98; P < .001) in patients with two to three positive lymph nodes. These findings support the independent prognostic value of the NSLN status in patients with two to three positive lymph nodes, suggesting that this information should be considered for the routine staging in patients with melanoma.

Optical See-Through Cancer Vision Goggles Enable Direct Patient Visualization and Real-Time Fluorescence-Guided Oncologic Surgery.

PubMed

Mondal, Suman B; Gao, Shengkui; Zhu, Nan; Habimana-Griffin, LeMoyne; Akers, Walter J; Liang, Rongguang; Gruev, Viktor; Margenthaler, Julie; Achilefu, Samuel

2017-07-01

The inability to visualize the patient and surgical site directly, limits the use of current near infrared fluorescence-guided surgery systems for real-time sentinel lymph node biopsy and tumor margin assessment. We evaluated an optical see-through goggle augmented imaging and navigation system (GAINS) for near-infrared, fluorescence-guided surgery. Tumor-bearing mice injected with a near infrared cancer-targeting agent underwent fluorescence-guided, tumor resection. Female Yorkshire pigs received hind leg intradermal indocyanine green injection and underwent fluorescence-guided, popliteal lymph node resection. Four breast cancer patients received 99m Tc-sulfur colloid and indocyanine green retroareolarly before undergoing sentinel lymph node biopsy using radioactive tracking and fluorescence imaging. Three other breast cancer patients received indocyanine green retroareolarly before undergoing standard-of-care partial mastectomy, followed by fluorescence imaging of resected tumor and tumor cavity for margin assessment. Using near-infrared fluorescence from the dyes, the optical see-through GAINS accurately identified all mouse tumors, pig lymphatics, and four pig popliteal lymph nodes with high signal-to-background ratio. In 4 human breast cancer patients, 11 sentinel lymph nodes were identified with a detection sensitivity of 86.67 ± 0.27% for radioactive tracking and 100% for GAINS. Tumor margin status was accurately predicted by GAINS in all three patients, including clear margins in patients 1 and 2 and positive margins in patient 3 as confirmed by paraffin-embedded section histopathology. The optical see-through GAINS prototype enhances near infrared fluorescence-guided surgery for sentinel lymph node biopsy and tumor margin assessment in breast cancer patients without disrupting the surgical workflow in the operating room.

Ultrasound-based clinical prediction rule model for detecting papillary thyroid cancer in cervical lymph nodes: A pilot study.

PubMed

Patel, Nayana U; McKinney, Kristin; Kreidler, Sarah M; Bieker, Teresa M; Russ, Paul; Roberts, Katherine; Glueck, Deborah H; Albuja-Cruz, Maria; Klopper, Joshua; Haugen, Bryan R

2016-01-01

To identify sonographic features of cervical lymph nodes (LNs) that are associated with papillary thyroid cancer (PTC) and to develop a prediction model for classifying nodes as metastatic or benign. This retrospective study included the records of postthyroidectomy patients with PTC who had undergone cervical ultrasound and LN biopsy. LN location, size, shape, hilum, echopattern, Doppler flow, and microcalcifications were assessed. Model selection was used to identify features associated with malignant LNs and to build a predictive, binary-outcome, generalized linear mixed model. A cross-validated receiver operating characteristic analysis was conducted to assess the accuracy of the model for classifying metastatic nodes. We analyzed records from 71 LNs (23 metastatic) in 44 patients (16 with PTC). The predictive model included a nonhomogeneous echopattern (odds ratio [OR], 5.73; 95% confidence interval [CI], 1.07-30.74; p = 0.04), microcalcifications (OR, 4.91; 95% CI, 0.91-26.54; p = 0.06), and volume (OR, 2.57; 95% CI, 0.66-9.99; p = 0.16) as predictors. The model had an area under the curve of 0.74 (95% CI, 0.60-0.85), sensitivity of 65% (95% CI, 50% to 78%), and specificity of 85% (95% CI, 73% to 94%) at the Youden optimal cut point of 0.38. Nonhomogeneous echopattern, microcalcifications, and node volume were predictive of malignant LNs in patients with PTC. A larger sample is needed to validate this model. © 2015 Wiley Periodicals, Inc.

A Bayesian Sampler for Optimization of Protein Domain Hierarchies

PubMed Central

2014-01-01

Abstract The process of identifying and modeling functionally divergent subgroups for a specific protein domain class and arranging these subgroups hierarchically has, thus far, largely been done via manual curation. How to accomplish this automatically and optimally is an unsolved statistical and algorithmic problem that is addressed here via Markov chain Monte Carlo sampling. Taking as input a (typically very large) multiple-sequence alignment, the sampler creates and optimizes a hierarchy by adding and deleting leaf nodes, by moving nodes and subtrees up and down the hierarchy, by inserting or deleting internal nodes, and by redefining the sequences and conserved patterns associated with each node. All such operations are based on a probability distribution that models the conserved and divergent patterns defining each subgroup. When we view these patterns as sequence determinants of protein function, each node or subtree in such a hierarchy corresponds to a subgroup of sequences with similar biological properties. The sampler can be applied either de novo or to an existing hierarchy. When applied to 60 protein domains from multiple starting points in this way, it converged on similar solutions with nearly identical log-likelihood ratio scores, suggesting that it typically finds the optimal peak in the posterior probability distribution. Similarities and differences between independently generated, nearly optimal hierarchies for a given domain help distinguish robust from statistically uncertain features. Thus, a future application of the sampler is to provide confidence measures for various features of a domain hierarchy. PMID:24494927

A Tree Based Broadcast Scheme for (m, k)-firm Real-Time Stream in Wireless Sensor Networks.

PubMed

Park, HoSung; Kim, Beom-Su; Kim, Kyong Hoon; Shah, Babar; Kim, Ki-Il

2017-11-09

Recently, various unicast routing protocols have been proposed to deliver measured data from the sensor node to the sink node within the predetermined deadline in wireless sensor networks. In parallel with their approaches, some applications demand the specific service, which is based on broadcast to all nodes within the deadline, the feasible real-time traffic model and improvements in energy efficiency. However, current protocols based on either flooding or one-to-one unicast cannot meet the above requirements entirely. Moreover, as far as the authors know, there is no study for the real-time broadcast protocol to support the application-specific traffic model in WSN yet. Based on the above analysis, in this paper, we propose a new ( m , k )-firm-based Real-time Broadcast Protocol (FRBP) by constructing a broadcast tree to satisfy the ( m , k )-firm, which is applicable to the real-time model in resource-constrained WSNs. The broadcast tree in FRBP is constructed by the distance-based priority scheme, whereas energy efficiency is improved by selecting as few as nodes on a tree possible. To overcome the unstable network environment, the recovery scheme invokes rapid partial tree reconstruction in order to designate another node as the parent on a tree according to the measured ( m , k )-firm real-time condition and local states monitoring. Finally, simulation results are given to demonstrate the superiority of FRBP compared to the existing schemes in terms of average deadline missing ratio, average throughput and energy consumption.

Calibrated birth-death phylogenetic time-tree priors for bayesian inference.

PubMed

Heled, Joseph; Drummond, Alexei J

2015-05-01

Here we introduce a general class of multiple calibration birth-death tree priors for use in Bayesian phylogenetic inference. All tree priors in this class separate ancestral node heights into a set of "calibrated nodes" and "uncalibrated nodes" such that the marginal distribution of the calibrated nodes is user-specified whereas the density ratio of the birth-death prior is retained for trees with equal values for the calibrated nodes. We describe two formulations, one in which the calibration information informs the prior on ranked tree topologies, through the (conditional) prior, and the other which factorizes the prior on divergence times and ranked topologies, thus allowing uniform, or any arbitrary prior distribution on ranked topologies. Although the first of these formulations has some attractive properties, the algorithm we present for computing its prior density is computationally intensive. However, the second formulation is always faster and computationally efficient for up to six calibrations. We demonstrate the utility of the new class of multiple-calibration tree priors using both small simulations and a real-world analysis and compare the results to existing schemes. The two new calibrated tree priors described in this article offer greater flexibility and control of prior specification in calibrated time-tree inference and divergence time dating, and will remove the need for indirect approaches to the assessment of the combined effect of calibration densities and tree priors in Bayesian phylogenetic inference. © The Author(s) 2014. Published by Oxford University Press, on behalf of the Society of Systematic Biologists.

Characterisation of a fibre optic Raman probe within a hypodermic needle.

PubMed

Iping Petterson, Ingeborg E; Day, John C C; Fullwood, Leanne M; Gardner, Benjamin; Stone, Nick

2015-11-01

We demonstrate the first use of a multifibre Raman probe that fits inside the bore of a hypodermic needle. A Raman probe containing multiple collection fibres provides improved signal collection efficiency in biological samples compared with a previous two-fibre design. Furthermore, probe performance (signal-to-noise ratios) compared favourably with the performance achieved in previous Raman microscope experiments able to distinguish between benign lymph nodes, primary malignancies in lymph nodes and secondary malignancies in lymph nodes. The experimental measurements presented here give an indication of the sampling volume of the Raman needle probe in lymphoid tissues. Liquid tissue phantoms were used that contained scattering medium encompassing a range of scattering properties similar to those of a variety of tissue types, including lymph node tissues. To validate the appropriateness of the phantoms, the sampling depth of the probe was also measured in excised lymph node tissue. More than 50 % of Raman photons collected were found to originate from between the tip of the needle and a depth of 500 μm into the tissue. The needle probe presented here achieves spectral quality comparable to that in numerous studies previously demonstrating Raman disease discrimination. It is expected that this approach could achieve targeted subcutaneous tissue measurements and be viable for use for the in vivo Raman diagnostics of solid organs located within a few centimetres below the skin's surface. Graphical Abstract Schematic of multi-fibre Raman needle probe with disposible tips and proximal optical filtration.

Additional Nodal Disease Prediction in Breast Cancer with Sentinel Lymph Node Metastasis Based on Clinicopathological Features.

PubMed

Orsaria, Paolo; Caredda, Emanuele; Genova, Federica; Materazzo, Marco; Capuano, Ilaria; Vanni, Gianluca; Granai, Alessandra Vittoria; DE Majo, Adriano; Portarena, Ilaria; Sileri, Pierpaolo; Petrella, Giuseppe; Palombi, Leonardo; Buonomo, Oreste Claudio

2018-04-01

The standard-of-care in breast cancer (BC) with positive sentinel lymph node (SLN) metastasis includes complete axillary lymph node dissection (ALND); however, almost half of such cases have no further tumor burden. This study aimed to assess the clinicopathological factors that predict non-SLN metastasis to define subgroups of SLN-positive patients in whom the axilla may be staged by SLN biopsy alone, while avoiding unnecessary overtreatment. The records of 191 patients with histologically-proven primary BC who underwent a positive (SLN) biopsy between 2005 and 2017 were reviewed. Patients with at least one tumor-involved SLN who underwent completion ALND were enrolled. Demographic and clinicopathological characteristics, including age, primary tumor size and histological grade, lymphovascular invasion, ratio of positive SLNs to the harvested SLNs, SLN metastasis size, and molecular subtype classification according to immunohistochemical biomarker status [estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2)], were evaluated. Data were collected retrospectively and analyzed using the Mann-Whitney and Chi-square tests (statistical significance: p<0.05). The incidence of non-SLN metastasis associated with positive SLN was 48.6% (93/191). The risk of additional nodal spread correlated with high sentinel nodal ratio >0.67 [odds ratio (OR)=2.55, p=0.032], luminal BC subtype (OR=2.67, p=0.06), HER2 overexpression (OR=0.4, p=0.016), and ER + PR - HER2 - profile (OR=2.95, p=0.027). There was a tendency (statistically insignificant; p>0.05) toward higher incidence of non SLN metastasis with increasing age and histological grade, which could be attributed to the small sample size. According to this study, sentinel nodal ratio and BC subtypes as per ER, PR, and HER2 status significantly predicted the likelihood of additional lymphatic involvement. Validation of these parameters in prospective studies is indicated, and may help individualize treatment modalities. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Meta-analysis of aberrant lymphatic drainage in recurrent breast cancer.

PubMed

Ahmed, M; Baker, R; Rubio, I T

2016-11-01

Sentinel node biopsy (SNB) in recurrent breast cancer offers targeted axillary staging compared with axillary lymph node dissection (ALND) or no treatment. The evidence for lymphatic mapping in recurrent breast cancer is reviewed, focusing on aberrant drainage and its implications for patient management. A meta-analysis of studies evaluating lymphatic mapping in recurrent breast cancer was performed. Outcomes included sentinel node identification, aberrant lymphatic pathways and metastatic node rates in aberrant drainage and ipsilateral axilla. Pooled odds ratios (ORs) and 95 per cent confidence intervals (c.i.) were estimated using fixed-effect analyses, or random-effects analyses in the event of statistically significant heterogeneity. Seven studies reported data on lymphatic mapping in 1053 patients with recurrent breast cancer. The intraoperative sentinel node identification rate was 59·6 (95 per cent c.i. 56·7 to 62·6) per cent, and significantly greater when the original axillary surgery was SNB compared with ALND (OR 2·97, 95 per cent c.i. 1·66 to 5·32). The rate of aberrant lymphatic drainage identification was 25·7 (23·0 to 28·3) per cent, and significantly greater when the original axillary surgery was ALND (OR 0·27, 0·19 to 0·38). The metastatic sentinel node rate was 10·4 (8·6 to 12·3) per cent, and a significantly greater metastatic nodal burden was identified in the ipsilateral axilla (OR 6·31, 1·03 to 38·79). Lymphatic mapping is feasible in recurrent breast cancer. It avoids ALND in over 50 per cent of patients who have undergone SNB, and allows the 4 per cent of patients with metastatically involved aberrant nodes to receive targeted surgical and adjuvant therapies. © 2016 BJS Society Ltd Published by John Wiley & Sons Ltd.

Association Between Adjuvant Chemotherapy and Overall Survival in Patients With Rectal Cancer and Pathological Complete Response After Neoadjuvant Chemotherapy and Resection.

PubMed

Dossa, Fahima; Acuna, Sergio A; Rickles, Aaron S; Berho, Mariana; Wexner, Steven D; Quereshy, Fayez A; Baxter, Nancy N; Chadi, Sami A

2018-04-19

Although American guidelines recommend use of adjuvant chemotherapy in patients with locally advanced rectal cancer, individuals who achieve a pathological complete response (pCR) following neoadjuvant chemoradiotherapy are less likely to receive adjuvant treatment than incomplete responders. The association and resection of adjuvant chemotherapy with survival in patients with pCR is unclear. To determine whether patients with locally advanced rectal cancer who achieve pCR after neoadjuvant chemoradiation therapy and resection benefit from the administration of adjuvant chemotherapy. This retrospective propensity score-matched cohort study identified patients with locally advanced rectal cancer from the National Cancer Database from 2006 through 2012. We selected patients with nonmetastatic invasive rectal cancer who achieved pCR after neoadjuvant chemoradiation therapy and resection. We matched patients who received adjuvant chemotherapy to patients who did not receive adjuvant treatment in a 1:1 ratio. We separately matched subgroups of patients with node-positive disease before treatment and node-negative disease before treatment to investigate for effect modification by pretreatment nodal status. We compared overall survival between groups using Kaplan-Meier survival methods and Cox proportional hazards models. We identified 2455 patients (mean age, 59.5 years; 59.8% men) with rectal cancer with pCR after neoadjuvant chemoradiation therapy and resection. We matched 667 patients with pCR who received adjuvant chemotherapy and at least 8 weeks of follow-up after surgery to patients with pCR who did not receive adjuvant treatment. Over a median follow-up of 3.1 years (interquartile range, 1.94-4.40 years), patients treated with adjuvant chemotherapy demonstrated better overall survival than those who did not receive adjuvant treatment (hazard ratio, 0.44; 95% CI, 0.28-0.70). When stratified by pretreatment nodal status, only those patients with pretreatment node-positive disease exhibited improved overall survival with administration of adjuvant chemotherapy (hazard ratio, 0.24; 95% CI, 0.10-0.58). The administration of adjuvant chemotherapy in patients with rectal cancer with pCR is associated with improved overall survival, particularly in patients with pretreatment node-positive disease. Although this study suggests a beneficial effect of adjuvant treatment on survival in patients with pCR, these results are limited by the presence of potential unmeasured confounding in this nonrandomized study.

Evaluation of the anaphylactoid potential of Andrographis paniculata extracts using the popliteal lymph node assay and P815 cell degranulation in vitro.

PubMed

Hu, Xuguang; Wen, Ya; Liu, Shasha; Luo, Jiabo; Tan, Xiaomei; Li, Zhiheng; Lu, Xinhua; Long, Xiaoying

2015-04-14

The anaphylactoid reactions induced by andrographis injection have repeatedly been reported. The aim of our study was to evaluate the immuno-sensitizing potential of extracts from Andrographis paniculata Nees and to screen for the constituent that is responsible for inducing the anaphylactoid reaction. In the direct popliteal lymph node assay (D-PLNA), female BALB/c mice were randomly divided into several groups with ten mice per group according to the experiment design, the right hind footpads of mice received a single subcutaneous injection of Andrographis paniculata (50 μl), and the left hind footpads received the same volume of vehicle. Seven days later, the mice were sacrificed by cervical dislocation, and the popliteal lymph nodes from both the left and right sides were removed. The weight (WI) and cellularity indices (CI) of the popliteal lymph nodes (PLNs) were then calculated, and the pathological changes of the PLNs were measured. In addition, P815 mast cells were collected for the in vitro cell degranulation experiment. The level of histamine, the percentage of cell degranulation and the ratio of ammonia glycosidase released were measured to further evaluate the potential allergenicity. Alcohol extract (AEE), ethyl acetate extract (EAE) and n-butanol extract (NBE) significantly increased the weight (WI > 2) and cell number (CI > 5) of PLNs (P < 0.05, P < 0.01). Additionally, all the three monomers of andrographis, namely NAD, AND, and DDA, significantly increased the weight (WI > 2) and cell number (CI > 5) of the PLNs (P < 0.05, P < 0.01). In the cell model, all of the different extract fractions (AEE, EAE and NBE) and the three monomers of andrographis markedly elevated the level of histamine, the percentage of cell degranulation and the ratio of ammonia glycosidase released. The diterpene lactone compounds of Andrographis paniculata Nees (total lactones of andrographolide) may have a potential sensitizing capacity in andrographis injection.

Mediastinal lymph node dissection versus mediastinal lymph node sampling for early stage non-small cell lung cancer: a systematic review and meta-analysis.

PubMed

Huang, Xiongfeng; Wang, Jianmin; Chen, Qiao; Jiang, Jielin

2014-01-01

This systematic review and meta-analysis aimed to evaluate the overall survival, local recurrence, distant metastasis, and complications of mediastinal lymph node dissection (MLND) versus mediastinal lymph node sampling (MLNS) in stage I-IIIA non-small cell lung cancer (NSCLC) patients. A systematic search of published literature was conducted using the main databases (MEDLINE, PubMed, EMBASE, and Cochrane databases) to identify relevant randomized controlled trials that compared MLND vs. MLNS in NSCLC patients. Methodological quality of included randomized controlled trials was assessed according to the criteria from the Cochrane Handbook for Systematic Review of Interventions (Version 5.1.0). Meta-analysis was performed using The Cochrane Collaboration's Review Manager 5.3. The results of the meta-analysis were expressed as hazard ratio (HR) or risk ratio (RR), with their corresponding 95% confidence interval (CI). We included results reported from six randomized controlled trials, with a total of 1,791 patients included in the primary meta-analysis. Compared to MLNS in NSCLC patients, there was no statistically significant difference in MLND on overall survival (HR = 0.77, 95% CI 0.55 to 1.08; P = 0.13). In addition, the results indicated that local recurrence rate (RR = 0.93, 95% CI 0.68 to 1.28; P = 0.67), distant metastasis rate (RR = 0.88, 95% CI 0.74 to 1.04; P = 0.15), and total complications rate (RR = 1.10, 95% CI 0.67 to 1.79; P = 0.72) were similar, no significant difference found between the two groups. Results for overall survival, local recurrence rate, and distant metastasis rate were similar between MLND and MLNS in early stage NSCLC patients. There was no evidence that MLND increased complications compared with MLNS. Whether or not MLND is superior to MLNS for stage II-IIIA remains to be determined.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, H; Cape Breton Cancer Centre, Sydney, NS

Purpose: To perform the comparison of dose distributions and dosevolume- histograms generated by VMAT and conventional field-in-field technique for left-sided breast and chestwall cancers; to determine whether VMAT offers more dosimetric benefits than does the field-in-field technique. Methods: All VMAT and field-in-filed plans were produced in Eclipse(version 10). Five plans were generated for left-sided breast and leftsided chestwall with supraclavicular nodes, respectively. A clockwise arc (CW) and a counter-clockwise arc (CCW) were used with start and stop angles being 310o±10o and 140o±10o. Collimator angles were 30o for CW and 330o for CCW. The conformity index (CI) is the ratio ofmore » V95% over PTV. The homogeneity index (HI) is the ratio of the difference between D2% and D98% over the prescribed dose. The V5, as an indicator of low dose bath to organs-at-risk, was used for ipsilateral lung, heart, contralateral lung, and contralateral breast. The V20, as an indicator of radiation pneumonitis, was used for ipsilateral lung. Results: Breast/chestwall VMAT delivers much higher low dose bath to ipsilateral lung, contralateral lung and contralateral breast/chestwall for both intact breast and chestwall with nodes. V5 for heart is increased in VMAT plans. V20 for ipsilateral lung is lower in VMAT plans. PTV coverage is similar for both techniques. For one particular chestwall patient with supraclavicular and internal mammary nodes, VMAT offers superior dose coverage of PTVs with slightly more low-dose-wash to heart, contralateral lung and contralateral breast. Conclusion: This study indicates that there is generally no benefit using VMAT for left-sided intact breast, due to large low-dose-bath (5Gy) to normal tissues with insignificant improvement in PTV coverage. Dosimetric benefits will be seen in VMAT plans for some chestwall patients with large size, and/or internal mammary nodes, etc. Whether a chestwall patient is treated with VMAT should be carefully analyzed on an individual basis.« less

Metabolic Tumor Volume on 18F-FDG PET/CT Improves Preoperative Identification of High-Risk Endometrial Carcinoma Patients.

PubMed

Husby, Jenny A; Reitan, Bernt C; Biermann, Martin; Trovik, Jone; Bjørge, Line; Magnussen, Inger J; Salvesen, Øyvind O; Salvesen, Helga B; Haldorsen, Ingfrid S

2015-08-01

Our objective was to prospectively explore the diagnostic value of (18)F-FDG PET/CT for preoperative staging in endometrial carcinomas and to investigate whether (18)F-FDG PET-specific quantitative tumor parameters reflect clinical and histologic characteristics. Preoperative (18)F-FDG PET/CT was prospectively performed on 129 consecutive endometrial carcinoma patients. Two physicians who did not know the clinical findings or staging results independently reviewed the images, assessing primary tumor, cervical stroma involvement and metastatic spread, and determining maximum and mean standardized uptake value (SUVmax and SUVmean, respectively) for tumor, metabolic tumor volume (MTV), and total lesion glycolysis (TLG). All parameters were analyzed in relation to histomorphologic and clinical tumor characteristics. Receiver-operating-characteristic curves for identification of deep myometrial invasion and lymph node metastases were generated, and MTV cutoffs for predicting deep myometrial invasion and lymph node metastases were calculated. The sensitivity, specificity, and accuracy of (18)F-FDG PET/CT for the detection of lymph node metastases were 77%-85%, 91%-96%, and 89%-93%, respectively. SUVmax, SUVmean, MTV, and TLG were significantly related to deep myometrial invasion, presence of lymph node metastases, and high histologic grade (P < 0.015 for all) and independently predicted deep myometrial invasion (P < 0.015) and lymph node metastases (P < 0.025) after adjustment for preoperative histologic risk (based on subtype and grade) in endometrial biopsies. Optimal cutoffs for MTV in predicting deep myometrial invasion (20 mL) and the presence of lymph node metastases (30 mL) yielded odds ratios of 7.8 (P < 0.001) and 16.5 (P = 0.001), respectively. (18)F-FDG PET/CT represents a clinically valuable tool for preoperatively evaluating the presence of lymph node metastases in endometrial carcinoma patients. Applying MTV cutoffs for the prediction of deep myometrial invasion and lymph node metastases may increase diagnostic accuracy and aid preoperative identification of high-risk patients, enabling restriction of lymphadenectomy for patients with a low risk of aggressive disease. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Price of anarchy on heterogeneous traffic-flow networks

NASA Astrophysics Data System (ADS)

Rose, A.; O'Dea, R.; Hopcraft, K. I.

2016-09-01

The efficiency of routing traffic through a network, comprising nodes connected by links whose cost of traversal is either fixed or varies in proportion to volume of usage, can be measured by the "price of anarchy." This is the ratio of the cost incurred by agents who act to minimize their individual expenditure to the optimal cost borne by the entire system. As the total traffic load and the network variability—parameterized by the proportion of variable-cost links in the network—changes, the behaviors that the system presents can be understood with the introduction of a network of simpler structure. This is constructed from classes of nonoverlapping paths connecting source to destination nodes that are characterized by the number of variable-cost edges they contain. It is shown that localized peaks in the price of anarchy occur at critical traffic volumes at which it becomes beneficial to exploit ostensibly more expensive paths as the network becomes more congested. Simulation results verifying these findings are presented for the variation of the price of anarchy with the network's size, aspect ratio, variability, and traffic load.

Price of anarchy on heterogeneous traffic-flow networks.

PubMed

Rose, A; O'Dea, R; Hopcraft, K I

2016-09-01

The efficiency of routing traffic through a network, comprising nodes connected by links whose cost of traversal is either fixed or varies in proportion to volume of usage, can be measured by the "price of anarchy." This is the ratio of the cost incurred by agents who act to minimize their individual expenditure to the optimal cost borne by the entire system. As the total traffic load and the network variability-parameterized by the proportion of variable-cost links in the network-changes, the behaviors that the system presents can be understood with the introduction of a network of simpler structure. This is constructed from classes of nonoverlapping paths connecting source to destination nodes that are characterized by the number of variable-cost edges they contain. It is shown that localized peaks in the price of anarchy occur at critical traffic volumes at which it becomes beneficial to exploit ostensibly more expensive paths as the network becomes more congested. Simulation results verifying these findings are presented for the variation of the price of anarchy with the network's size, aspect ratio, variability, and traffic load.

A Secure Region-Based Geographic Routing Protocol (SRBGR) for Wireless Sensor Networks

PubMed Central

Adnan, Ali Idarous; Hanapi, Zurina Mohd; Othman, Mohamed; Zukarnain, Zuriati Ahmad

2017-01-01

Due to the lack of dependency for routing initiation and an inadequate allocated sextant on responding messages, the secure geographic routing protocols for Wireless Sensor Networks (WSNs) have attracted considerable attention. However, the existing protocols are more likely to drop packets when legitimate nodes fail to respond to the routing initiation messages while attackers in the allocated sextant manage to respond. Furthermore, these protocols are designed with inefficient collection window and inadequate verification criteria which may lead to a high number of attacker selections. To prevent the failure to find an appropriate relay node and undesirable packet retransmission, this paper presents Secure Region-Based Geographic Routing Protocol (SRBGR) to increase the probability of selecting the appropriate relay node. By extending the allocated sextant and applying different message contention priorities more legitimate nodes can be admitted in the routing process. Moreover, the paper also proposed the bound collection window for a sufficient collection time and verification cost for both attacker identification and isolation. Extensive simulation experiments have been performed to evaluate the performance of the proposed protocol in comparison with other existing protocols. The results demonstrate that SRBGR increases network performance in terms of the packet delivery ratio and isolates attacks such as Sybil and Black hole. PMID:28121992

A Smart Collaborative Routing Protocol for Reliable Data Diffusion in IoT Scenarios.

PubMed

Ai, Zheng-Yang; Zhou, Yu-Tong; Song, Fei

2018-06-13

It is knotty for current routing protocols to meet the needs of reliable data diffusion during the Internet of Things (IoT) deployments. Due to the random placement, limited resources and unattended features of existing sensor nodes, the wireless transmissions are easily exposed to unauthorized users, which becomes a vulnerable area for various malicious attacks, such as wormhole and Sybil attacks. However, the scheme based on geographic location is a suitable candidate to defend against them. This paper is inspired to propose a smart collaborative routing protocol, Geographic energy aware routing and Inspecting Node (GIN), for guaranteeing the reliability of data exchanging. The proposed protocol integrates the directed diffusion routing, Greedy Perimeter Stateless Routing (GPSR), and the inspecting node mechanism. We first discuss current wireless routing protocols from three diverse perspectives (improving transmission rate, shortening transmission range and reducing transmission consumption). Then, the details of GIN, including the model establishment and implementation processes, are presented by means of the theoretical analysis. Through leveraging the game theory, the inspecting node is elected to monitor the network behaviors. Thirdly, we evaluate the network performances, in terms of transmission delay, packet loss ratio, and throughput, between GIN and three traditional schemes (i.e., Flooding, GPSR, and GEAR). The simulation results illustrate that the proposed protocol is able to outperform the others.

A Secure Region-Based Geographic Routing Protocol (SRBGR) for Wireless Sensor Networks.

PubMed

Adnan, Ali Idarous; Hanapi, Zurina Mohd; Othman, Mohamed; Zukarnain, Zuriati Ahmad

2017-01-01

Due to the lack of dependency for routing initiation and an inadequate allocated sextant on responding messages, the secure geographic routing protocols for Wireless Sensor Networks (WSNs) have attracted considerable attention. However, the existing protocols are more likely to drop packets when legitimate nodes fail to respond to the routing initiation messages while attackers in the allocated sextant manage to respond. Furthermore, these protocols are designed with inefficient collection window and inadequate verification criteria which may lead to a high number of attacker selections. To prevent the failure to find an appropriate relay node and undesirable packet retransmission, this paper presents Secure Region-Based Geographic Routing Protocol (SRBGR) to increase the probability of selecting the appropriate relay node. By extending the allocated sextant and applying different message contention priorities more legitimate nodes can be admitted in the routing process. Moreover, the paper also proposed the bound collection window for a sufficient collection time and verification cost for both attacker identification and isolation. Extensive simulation experiments have been performed to evaluate the performance of the proposed protocol in comparison with other existing protocols. The results demonstrate that SRBGR increases network performance in terms of the packet delivery ratio and isolates attacks such as Sybil and Black hole.

An Energy-Efficient Mobile Sink-Based Unequal Clustering Mechanism for WSNs.

PubMed

Gharaei, Niayesh; Abu Bakar, Kamalrulnizam; Mohd Hashim, Siti Zaiton; Hosseingholi Pourasl, Ali; Siraj, Mohammad; Darwish, Tasneem

2017-08-11

Network lifetime and energy efficiency are crucial performance metrics used to evaluate wireless sensor networks (WSNs). Decreasing and balancing the energy consumption of nodes can be employed to increase network lifetime. In cluster-based WSNs, one objective of applying clustering is to decrease the energy consumption of the network. In fact, the clustering technique will be considered effective if the energy consumed by sensor nodes decreases after applying clustering, however, this aim will not be achieved if the cluster size is not properly chosen. Therefore, in this paper, the energy consumption of nodes, before clustering, is considered to determine the optimal cluster size. A two-stage Genetic Algorithm (GA) is employed to determine the optimal interval of cluster size and derive the exact value from the interval. Furthermore, the energy hole is an inherent problem which leads to a remarkable decrease in the network's lifespan. This problem stems from the asynchronous energy depletion of nodes located in different layers of the network. For this reason, we propose Circular Motion of Mobile-Sink with Varied Velocity Algorithm (CM2SV2) to balance the energy consumption ratio of cluster heads (CH). According to the results, these strategies could largely increase the network's lifetime by decreasing the energy consumption of sensors and balancing the energy consumption among CHs.

The Optimization Based Dynamic and Cyclic Working Strategies for Rechargeable Wireless Sensor Networks with Multiple Base Stations and Wireless Energy Transfer Devices

PubMed Central

Ding, Xu; Han, Jianghong; Shi, Lei

2015-01-01

In this paper, the optimal working schemes for wireless sensor networks with multiple base stations and wireless energy transfer devices are proposed. The wireless energy transfer devices also work as data gatherers while charging sensor nodes. The wireless sensor network is firstly divided into sub networks according to the concept of Voronoi diagram. Then, the entire energy replenishing procedure is split into the pre-normal and normal energy replenishing stages. With the objective of maximizing the sojourn time ratio of the wireless energy transfer device, a continuous time optimization problem for the normal energy replenishing cycle is formed according to constraints with which sensor nodes and wireless energy transfer devices should comply. Later on, the continuous time optimization problem is reshaped into a discrete multi-phased optimization problem, which yields the identical optimality. After linearizing it, we obtain a linear programming problem that can be solved efficiently. The working strategies of both sensor nodes and wireless energy transfer devices in the pre-normal replenishing stage are also discussed in this paper. The intensive simulations exhibit the dynamic and cyclic working schemes for the entire energy replenishing procedure. Additionally, a way of eliminating “bottleneck” sensor nodes is also developed in this paper. PMID:25785305

The optimization based dynamic and cyclic working strategies for rechargeable wireless sensor networks with multiple base stations and wireless energy transfer devices.

PubMed

Ding, Xu; Han, Jianghong; Shi, Lei

2015-03-16

In this paper, the optimal working schemes for wireless sensor networks with multiple base stations and wireless energy transfer devices are proposed. The wireless energy transfer devices also work as data gatherers while charging sensor nodes. The wireless sensor network is firstly divided into sub networks according to the concept of Voronoi diagram. Then, the entire energy replenishing procedure is split into the pre-normal and normal energy replenishing stages. With the objective of maximizing the sojourn time ratio of the wireless energy transfer device, a continuous time optimization problem for the normal energy replenishing cycle is formed according to constraints with which sensor nodes and wireless energy transfer devices should comply. Later on, the continuous time optimization problem is reshaped into a discrete multi-phased optimization problem, which yields the identical optimality. After linearizing it, we obtain a linear programming problem that can be solved efficiently. The working strategies of both sensor nodes and wireless energy transfer devices in the pre-normal replenishing stage are also discussed in this paper. The intensive simulations exhibit the dynamic and cyclic working schemes for the entire energy replenishing procedure. Additionally, a way of eliminating "bottleneck" sensor nodes is also developed in this paper.

Brain connectivity aberrations in anabolic-androgenic steroid users.

PubMed

Westlye, Lars T; Kaufmann, Tobias; Alnæs, Dag; Hullstein, Ingunn R; Bjørnebekk, Astrid

2017-01-01

Sustained anabolic-androgenic steroid (AAS) use has adverse behavioral consequences, including aggression, violence and impulsivity. Candidate mechanisms include disruptions of brain networks with high concentrations of androgen receptors and critically involved in emotional and cognitive regulation. Here, we tested the effects of AAS on resting-state functional brain connectivity in the largest sample of AAS-users to date. We collected resting-state functional magnetic resonance imaging (fMRI) data from 151 males engaged in heavy resistance strength training. 50 users tested positive for AAS based on the testosterone to epitestosterone (T/E) ratio and doping substances in urine. 16 previous users and 59 controls tested negative. We estimated brain network nodes and their time-series using ICA and dual regression and defined connectivity matrices as the between-node partial correlations. In line with the emotional and behavioral consequences of AAS, current users exhibited reduced functional connectivity between key nodes involved in emotional and cognitive regulation, in particular reduced connectivity between the amygdala and default-mode network (DMN) and between the dorsal attention network (DAN) and a frontal node encompassing the superior and inferior frontal gyri (SFG/IFG) and the anterior cingulate cortex (ACC), with further reductions as a function of dependency, lifetime exposure, and cycle state (on/off).

Sentinel-lymph-node resection compared with conventional axillary-lymph-node dissection in clinically node-negative patients with breast cancer: overall survival findings from the NSABP B-32 randomised phase 3 trial.

PubMed

Krag, David N; Anderson, Stewart J; Julian, Thomas B; Brown, Ann M; Harlow, Seth P; Costantino, Joseph P; Ashikaga, Takamaru; Weaver, Donald L; Mamounas, Eleftherios P; Jalovec, Lynne M; Frazier, Thomas G; Noyes, R Dirk; Robidoux, André; Scarth, Hugh Mc; Wolmark, Norman

2010-10-01

Sentinel-lymph-node (SLN) surgery was designed to minimise the side-effects of lymph-node surgery but still offer outcomes equivalent to axillary-lymph-node dissection (ALND). The aims of National Surgical Adjuvant Breast and Bowel Project (NSABP) trial B-32 were to establish whether SLN resection in patients with breast cancer achieves the same survival and regional control as ALND, but with fewer side-effects. NSABP B-32 was a randomised controlled phase 3 trial done at 80 centres in Canada and the USA between May 1, 1999, and Feb 29, 2004. Women with invasive breast cancer were randomly assigned to either SLN resection plus ALND (group 1) or to SLN resection alone with ALND only if the SLNs were positive (group 2). Random assignment was done at the NSABP Biostatistical Center (Pittsburgh, PA, USA) with a biased coin minimisation approach in an allocation ratio of 1:1. Stratification variables were age at entry (≤ 49 years, ≥ 50 years), clinical tumour size (≤ 2·0 cm, 2·1-4·0 cm, ≥ 4·1 cm), and surgical plan (lumpectomy, mastectomy). SLN resection was done with a blue dye and radioactive tracer. Outcome analyses were done in patients who were assessed as having pathologically negative sentinel nodes and for whom follow-up data were available. The primary endpoint was overall survival. Analyses were done on an intention-to-treat basis. All deaths, irrespective of cause, were included. The mean time on study for the SLN-negative patients with follow-up information was 95·6 months (range 70·1-126·7). This study is registered with ClinicalTrials.gov, number NCT00003830. 5611 women were randomly assigned to the treatment groups, 3989 had pathologically negative SLN. 309 deaths were reported in the 3986 SLN-negative patients with follow-up information: 140 of 1975 patients in group 1 and 169 of 2011 in group 2. Log-rank comparison of overall survival in groups 1 and 2 yielded an unadjusted hazard ratio (HR) of 1·20 (95% CI 0·96-1·50; p=0·12). 8-year Kaplan-Meier estimates for overall survival were 91·8% (95% CI 90·4-93·3) in group 1 and 90·3% (88·8-91·8) in group 2. Treatment comparisons for disease-free survival yielded an unadjusted HR of 1·05 (95% CI 0·90-1·22; p=0·54). 8-year Kaplan-Meier estimates for disease-free survival were 82·4% (80·5-84·4) in group 1 and 81·5% (79·6-83·4) in group 2. There were eight regional-node recurrences as first events in group 1 and 14 in group 2 (p=0·22). Patients are continuing follow-up for longer-term assessment of survival and regional control. The most common adverse events were allergic reactions, mostly related to the administration of the blue dye. Overall survival, disease-free survival, and regional control were statistically equivalent between groups. When the SLN is negative, SLN surgery alone with no further ALND is an appropriate, safe, and effective therapy for breast cancer patients with clinically negative lymph nodes. US Public Health Service, National Cancer Institute, and Department of Health and Human Services. Copyright © 2010 Elsevier Ltd. All rights reserved.

Computational analysis of complex systems: Applications to population dynamics and networks

NASA Astrophysics Data System (ADS)

Molnar, Ferenc

In most complex evolving systems, we can often find a critical subset of the constituents that can initiate a global change in the entire system. For example, in complex networks, a critical subset of nodes can efficiently spread information, influence, or control dynamical processes over the entire network. Similarly, in nonlinear dynamics, we can locate key variables, or find the necessary parameters, to reach the attraction basin of a desired global state. In both cases, a fundamental goal is finding the ability to efficiently control these systems. We study two distinct complex systems in this dissertation, exploring these topics. First, we analyze a population dynamics model describing interactions of sex-structured population groups. Specifically, we analyze how a sex-linked genetic trait's ecological consequence (population survival or extinction) can be influenced by the presence of sex-specific cultural mortality traits, motivated by the desire to expand the theoretical understanding of the role of biased sex ratios in organisms. We analyze dynamics within a single population group, as well as between competing groups. We find that there is a finite range of sex ratio bias that can be maintained in stable equilibrium by sex-specific mortalities. We also find that the outcome of an invasion and the ensuing between-group competition depends not on larger equilibrium group densities, but on the higher allocation of sex-ratio genes. When we extend the model with diffusive dispersal, we find that a critical patch size for achieving positive growth only exists if the population expands into an empty environment. If a resident population is already present that can be exploited by the invading group, then any small seed of invader can advance from rarity, in the mean-field approximation, as long as the local competition dynamics favors the invader's survival. Most spatial models assume initial populations with a uniform distribution inside a finite patch; a simple, but not a cost-efficient approach. We show, using a novel application of simulated annealing, that a specific, non-trivial shape of spatial distribution can minimize the total cost of successful invasion, i.e., the cost of ecological restoration. Further, our approach can be generalized to essentially any reaction-diffusion model with diffusive spreading. In the second part of the dissertation we conduct an extensive study of minimum dominating sets (MDS) in complex networks; particularly, in scale-free networks. MDS is the smallest subset of nodes in a network that can reach every other node as nearest neighbors, thus it provides a key subset of nodes that play critical role in controllability and observability of social, biological, and technological networks. Continued interest in network control, monitoring and influencing of complex networks motivates our research of understanding the properties and practical application-related issues of the MDS. Our study of the scaling behavior reveals that the size of MDS always scales linearly with network size, as long as the power-law degree exponent gamma of the degree distribution is larger than 2. However, when gamma<2, a domination transition occurs, allowing the MDS size to become O(1), leading to easily dominated networks, under certain structural conditions. Motivated by practical applicability in large networks, we develop a new dominating set selection method, derived from probabilistic node selection techniques, which can select small dominating sets without complete network topology information. We also show that the effectiveness of our method, as well as the effectiveness of other heuristics of dominating set selection, strongly depends on the assortativity of networks. Finally, we conduct a numerical study to analyze the fraction of nodes that remain dominated, after the network is damaged, and some nodes are removed. We find that dominating sets optimized for small size are particularly vulnerable to damage; a significant amount of "domination coverage" may be lost if key dominator nodes are deleted. However, we also find that increasing the redundancy of dominating sets by adding a few well-picked nodes can successfully increase the post-damage dominated fraction of the network. Based on this idea, we develop two algorithms to build dominating sets with flexible balance between size and damage resilience.

Effective-medium theory of elastic waves in random networks of rods.

PubMed

Katz, J I; Hoffman, J J; Conradi, M S; Miller, J G

2012-06-01

We formulate an effective medium (mean field) theory of a material consisting of randomly distributed nodes connected by straight slender rods, hinged at the nodes. Defining wavelength-dependent effective elastic moduli, we calculate both the static moduli and the dispersion relations of ultrasonic longitudinal and transverse elastic waves. At finite wave vector k the waves are dispersive, with phase and group velocities decreasing with increasing wave vector. These results are directly applicable to networks with empty pore space. They also describe the solid matrix in two-component (Biot) theories of fluid-filled porous media. We suggest the possibility of low density materials with higher ratios of stiffness and strength to density than those of foams, aerogels, or trabecular bone.

Correlation between obesity and fat-infiltrated axillary lymph nodes visualized on mammography.

PubMed

diFlorio Alexander, Roberta M; Haider, Steffen J; MacKenzie, Todd; Goodrich, Martha E; Weiss, Julie; Onega, Tracy

2018-01-05

Using screening mammography, this study investigated the association between obesity and axillary lymph node (LN) size and morphology. We conducted a retrospective review of 188 females who underwent screening mammography at an academic medical centre. Length and width of the LN and hilum were measured in the largest, mammographically visible axillary node. The hilo-cortical ratio (HCR) was calculated as the hilar width divided by the cortical width. Measurements were performed by a board certified breast radiologist and a resident radiology physician. Inter-rater agreement was assessed with Pearson correlation coefficient. We performed multivariable regression analysis for associations of LN measurements with body mass index (BMI), breast density and age. There was a strong association between BMI and LN dimensions, hilum dimensions and HCR (p < 0.001 for all metrics). There was no significant change in cortex width with increasing BMI (p = 0.15). Increases in LN length and width were found with increasing BMI [0.6 mm increase in length per unit BMI, 95% CI (0.4-0.8), p < 0.001 and0.3 mm increase in width per unit BMI, 95% CI(0.2-0.4), p < 0.001, respectively]. Inter-rater reliability for lymph node and hilum measurements was 0.57-0.72. We found a highly significant association between increasing BMI and axillary LN dimensions independent of age and breast density with strong interobserver agreement. The increase in LN size was driven by expansion of the LN hilum secondary to fat infiltration. Advances in knowledge: This preliminary work determined a relationship between fat infiltrated axillary lymph nodes and obesity.

A simplified CT-based definition of the supraclavicular and infraclavicular nodal volumes in breast cancer.

PubMed

Atean, I; Pointreau, Y; Ouldamer, L; Monghal, C; Bougnoux, A; Bera, G; Barillot, I

2013-02-01

The available contouring guidelines for the supraclavicular and infraclavicular lymph nodes appeared to be inadequate for their delineation on non-enhanced computed tomography (CT) scans. For this purpose, we developed delineation guidelines for the clinical target volumes (CTV) of these lymph nodes on non-enhanced CT-slices performed in the treatment position of breast cancer. A fresh female cadaver study as well as delineation and an anatomical descriptions review were performed to propose a simplified definition of the supra- and infraclavicular lymph nodes using readily identifiable anatomical structures. This definition was developed jointly by breast radiologists, breast surgeons, and radiation oncologists. To validate these guidelines, the primary investigator and seven radiation oncologists (observers) independently delineated 10 different nodal CTVs. The primary investigator contours were considered to be the gold standard contours. Contour accuracy and concordance were evaluated. Written guidelines for the delineation of supra- and infraclavicular lymph nodes CTVs were developed. Consistent contours with minimal variability existed between the delineated volumes; the mean kappa index was 0.83. The mean common contoured and additional contoured volumes were 84.6% and 18.5%, respectively. The mean overlap volume ratio was 0.71. Simplified CT-based atlas for delineation of the supra- and infraclavicular lymph nodes for locoregional irradiation of the breast on non-enhanced CT-scan, have been developed in this study. This atlas provides a consistent set of guidelines for delineating these volumes. Copyright © 2012 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

beta(2)microglobulin mRNA expression levels are prognostic for lymph node metastasis in colorectal cancer patients.

PubMed

Shrout, J; Yousefzadeh, M; Dodd, A; Kirven, K; Blum, C; Graham, A; Benjamin, K; Hoda, R; Krishna, M; Romano, M; Wallace, M; Garrett-Mayer, E; Mitas, M

2008-06-17

Colorectal cancer (CRC) is the fourth most common non-cutaneous malignancy in the United States and the second most frequent cause of cancer-related death. One of the most important determinants of CRC survival is lymph node metastasis. To determine whether molecular markers might be prognostic for lymph node metastases, we measured by quantitative real-time RT-PCR the expression levels of 15 cancer-associated genes in formalin-fixed paraffin-embedded primary tissues derived from stage I-IV CRC patients with (n=20) and without (n=18) nodal metastases. Using the mean of the 15 genes as an internal reference control, we observed that low expression of beta(2)microglobulin (B2M) was a strong prognostic indicator of lymph node metastases (area under the curve (AUC)=0.85; 95% confidence interval (CI)=0.69-0.94). We also observed that the expression ratio of B2M/Spint2 had the highest prognostic accuracy (AUC=0.87; 95% CI=0.71-0.96) of all potential two-gene combinations. Expression values of Spint2 correlated with the mean of the entire gene set at an R(2) value of 0.97, providing evidence that Spint2 serves not as an independent prognostic gene, but rather as a reliable reference control gene. These studies are the first to demonstrate a prognostic role of B2M at the mRNA level and suggest that low B2M expression levels might be useful for identifying patients with lymph node metastasis and/or poor survival.

A Tree Based Broadcast Scheme for (m, k)-firm Real-Time Stream in Wireless Sensor Networks

PubMed Central

Park, HoSung; Kim, Beom-Su; Kim, Kyong Hoon; Shah, Babar; Kim, Ki-Il

2017-01-01

Recently, various unicast routing protocols have been proposed to deliver measured data from the sensor node to the sink node within the predetermined deadline in wireless sensor networks. In parallel with their approaches, some applications demand the specific service, which is based on broadcast to all nodes within the deadline, the feasible real-time traffic model and improvements in energy efficiency. However, current protocols based on either flooding or one-to-one unicast cannot meet the above requirements entirely. Moreover, as far as the authors know, there is no study for the real-time broadcast protocol to support the application-specific traffic model in WSN yet. Based on the above analysis, in this paper, we propose a new (m, k)-firm-based Real-time Broadcast Protocol (FRBP) by constructing a broadcast tree to satisfy the (m, k)-firm, which is applicable to the real-time model in resource-constrained WSNs. The broadcast tree in FRBP is constructed by the distance-based priority scheme, whereas energy efficiency is improved by selecting as few as nodes on a tree possible. To overcome the unstable network environment, the recovery scheme invokes rapid partial tree reconstruction in order to designate another node as the parent on a tree according to the measured (m, k)-firm real-time condition and local states monitoring. Finally, simulation results are given to demonstrate the superiority of FRBP compared to the existing schemes in terms of average deadline missing ratio, average throughput and energy consumption. PMID:29120404

Efficient and Stable Routing Algorithm Based on User Mobility and Node Density in Urban Vehicular Network.

PubMed

Al-Mayouf, Yusor Rafid Bahar; Ismail, Mahamod; Abdullah, Nor Fadzilah; Wahab, Ainuddin Wahid Abdul; Mahdi, Omar Adil; Khan, Suleman; Choo, Kim-Kwang Raymond

2016-01-01

Vehicular ad hoc networks (VANETs) are considered an emerging technology in the industrial and educational fields. This technology is essential in the deployment of the intelligent transportation system, which is targeted to improve safety and efficiency of traffic. The implementation of VANETs can be effectively executed by transmitting data among vehicles with the use of multiple hops. However, the intrinsic characteristics of VANETs, such as its dynamic network topology and intermittent connectivity, limit data delivery. One particular challenge of this network is the possibility that the contributing node may only remain in the network for a limited time. Hence, to prevent data loss from that node, the information must reach the destination node via multi-hop routing techniques. An appropriate, efficient, and stable routing algorithm must be developed for various VANET applications to address the issues of dynamic topology and intermittent connectivity. Therefore, this paper proposes a novel routing algorithm called efficient and stable routing algorithm based on user mobility and node density (ESRA-MD). The proposed algorithm can adapt to significant changes that may occur in the urban vehicular environment. This algorithm works by selecting an optimal route on the basis of hop count and link duration for delivering data from source to destination, thereby satisfying various quality of service considerations. The validity of the proposed algorithm is investigated by its comparison with ARP-QD protocol, which works on the mechanism of optimal route finding in VANETs in urban environments. Simulation results reveal that the proposed ESRA-MD algorithm shows remarkable improvement in terms of delivery ratio, delivery delay, and communication overhead.

Physiological effects of Meloidogyne incognita infection on cotton genotypes with differing levels of resistance in the greenhouse

USDA-ARS?s Scientific Manuscript database

Greenhouse tests were conducted to evaluate 1) the effect of Meloidogyne incognita infection in cotton on plant growth and physiology including the height-to-node ratio, chlorophyll content, dark adapted quantum yield of photosystem II, and leaf area, and 2) the extent to which moderate or high leve...

Pediatric Type Follicular Lymphoma: A Rare Entity with Excellent Prognosis

DTIC Science & Technology

2018-01-19

lymphomas, has a median age range of 7.5-11.7, and has a male- female ratio of 4:1. This entity occurs most frequently in the tonsils and head and... neck lymph nodes. The pathogenesis of follicular lymphoma in adults is based upon immunoglobulin gene rearrangements with BCL2, BCL6, and MYC

Predictors and Patterns of Local, Regional, and Distant Failure in Squamous Cell Carcinoma of the Vulva.

PubMed

Bogani, Giorgio; Cromi, Antonella; Serati, Maurizio; Uccella, Stefano; Donato, Violante Di; Casarin, Jvan; Naro, Edoardo Di; Ghezzi, Fabio

2017-06-01

To identify factors predicting for recurrence in vulvar cancer patients undergoing surgical treatment. We retrospectively evaluated data of consecutive patients with squamous cell vulvar cancer treated between January 1, 1990 and December 31, 2013. Basic descriptive statistics and multivariable analysis were used to design predicting models influencing outcomes. Five-year disease-free survival (DFS) and overall survival (OS) were analyzed using the Cox model. The study included 101 patients affected by vulvar cancer: 64 (63%) stage I, 12 (12%) stage II, 20 (20%) stage III, and 5 (5%) stage IV. After a mean (SD) follow-up of 37.6 (22.1) months, 21 (21%) recurrences occurred. Local, regional, and distant failures were recorded in 14 (14%), 6 (6%), and 3 (3%) patients, respectively. Five-year DFS and OS were 77% and 82%, respectively. At multivariate analysis only stromal invasion >2 mm (hazard ratio: 4.9 [95% confidence interval, 1.17-21.1]; P=0.04) and extracapsular lymph node involvement (hazard ratio: 9.0 (95% confidence interval, 1.17-69.5); P=0.03) correlated with worse DFS, although no factor independently correlated with OS. Looking at factors influencing local and regional failure, we observed that stromal invasion >2 mm was the only factor predicting for local recurrence, whereas lymph node extracapsular involvement predicted for regional recurrence. Stromal invasion >2 mm and lymph node extracapsular spread are the most important factors predicting for local and regional failure, respectively. Studies evaluating the effectiveness of adjuvant treatment in high-risk patients are warranted.

Energy-efficient ECG compression on wireless biosensors via minimal coherence sensing and weighted ℓ₁ minimization reconstruction.

PubMed

Zhang, Jun; Gu, Zhenghui; Yu, Zhu Liang; Li, Yuanqing

2015-03-01

Low energy consumption is crucial for body area networks (BANs). In BAN-enabled ECG monitoring, the continuous monitoring entails the need of the sensor nodes to transmit a huge data to the sink node, which leads to excessive energy consumption. To reduce airtime over energy-hungry wireless links, this paper presents an energy-efficient compressed sensing (CS)-based approach for on-node ECG compression. At first, an algorithm called minimal mutual coherence pursuit is proposed to construct sparse binary measurement matrices, which can be used to encode the ECG signals with superior performance and extremely low complexity. Second, in order to minimize the data rate required for faithful reconstruction, a weighted ℓ1 minimization model is derived by exploring the multisource prior knowledge in wavelet domain. Experimental results on MIT-BIH arrhythmia database reveals that the proposed approach can obtain higher compression ratio than the state-of-the-art CS-based methods. Together with its low encoding complexity, our approach can achieve significant energy saving in both encoding process and wireless transmission.

An Efficient Next Hop Selection Algorithm for Multi-Hop Body Area Networks

PubMed Central

Ayatollahitafti, Vahid; Ngadi, Md Asri; Mohamad Sharif, Johan bin; Abdullahi, Mohammed

2016-01-01

Body Area Networks (BANs) consist of various sensors which gather patient’s vital signs and deliver them to doctors. One of the most significant challenges faced, is the design of an energy-efficient next hop selection algorithm to satisfy Quality of Service (QoS) requirements for different healthcare applications. In this paper, a novel efficient next hop selection algorithm is proposed in multi-hop BANs. This algorithm uses the minimum hop count and a link cost function jointly in each node to choose the best next hop node. The link cost function includes the residual energy, free buffer size, and the link reliability of the neighboring nodes, which is used to balance the energy consumption and to satisfy QoS requirements in terms of end to end delay and reliability. Extensive simulation experiments were performed to evaluate the efficiency of the proposed algorithm using the NS-2 simulator. Simulation results show that our proposed algorithm provides significant improvement in terms of energy consumption, number of packets forwarded, end to end delay and packet delivery ratio compared to the existing routing protocol. PMID:26771586

On the Simulation-Based Reliability of Complex Emergency Logistics Networks in Post-Accident Rescues.

PubMed

Wang, Wei; Huang, Li; Liang, Xuedong

2018-01-06

This paper investigates the reliability of complex emergency logistics networks, as reliability is crucial to reducing environmental and public health losses in post-accident emergency rescues. Such networks' statistical characteristics are analyzed first. After the connected reliability and evaluation indices for complex emergency logistics networks are effectively defined, simulation analyses of network reliability are conducted under two different attack modes using a particular emergency logistics network as an example. The simulation analyses obtain the varying trends in emergency supply times and the ratio of effective nodes and validates the effects of network characteristics and different types of attacks on network reliability. The results demonstrate that this emergency logistics network is both a small-world and a scale-free network. When facing random attacks, the emergency logistics network steadily changes, whereas it is very fragile when facing selective attacks. Therefore, special attention should be paid to the protection of supply nodes and nodes with high connectivity. The simulation method provides a new tool for studying emergency logistics networks and a reference for similar studies.

On the Simulation-Based Reliability of Complex Emergency Logistics Networks in Post-Accident Rescues

PubMed Central

Wang, Wei; Huang, Li; Liang, Xuedong

2018-01-01

This paper investigates the reliability of complex emergency logistics networks, as reliability is crucial to reducing environmental and public health losses in post-accident emergency rescues. Such networks’ statistical characteristics are analyzed first. After the connected reliability and evaluation indices for complex emergency logistics networks are effectively defined, simulation analyses of network reliability are conducted under two different attack modes using a particular emergency logistics network as an example. The simulation analyses obtain the varying trends in emergency supply times and the ratio of effective nodes and validates the effects of network characteristics and different types of attacks on network reliability. The results demonstrate that this emergency logistics network is both a small-world and a scale-free network. When facing random attacks, the emergency logistics network steadily changes, whereas it is very fragile when facing selective attacks. Therefore, special attention should be paid to the protection of supply nodes and nodes with high connectivity. The simulation method provides a new tool for studying emergency logistics networks and a reference for similar studies. PMID:29316614

Efficient, balanced, transmission line RF circuits by back propagation of common impedance nodes.

PubMed

Markhasin, Evgeny; Hu, Jianping; Su, Yongchao; Herzfeld, Judith; Griffin, Robert G

2013-06-01

We present a new, efficient strategy for designing fully balanced transmission line RF circuits for solid state NMR probes based on back propagation of common impedance nodes (BPCIN). In this approach, the impedance node phenomenon is the sole means of achieving mutual RF isolation and balance in all RF channels. BPCIN is illustrated using a custom double resonance 3.2 mm MAS probe operating at 500 MHz ((1)H) and 125 MHz ((13)C). When fully optimized, the probe is capable of producing high homogeneity (810°/90° ratios of 86% and 89% for (1)H and (13)C, respectively) and high efficiency (γB1=100 kHz for (1)H and (13)C at 70 W and 180 W of RF input, respectively; up to 360 kHz for (1)H). The probe's performance is illustrated by 2D MAS correlation spectra of microcrystals of the tripeptide N-f-MLF-OH and hydrated amyloid fibrils of the protein PI3-SH3. Copyright © 2013 Elsevier Inc. All rights reserved.

A Novel Cross-Layer Routing Protocol Based on Network Coding for Underwater Sensor Networks.

PubMed

Wang, Hao; Wang, Shilian; Bu, Renfei; Zhang, Eryang

2017-08-08

Underwater wireless sensor networks (UWSNs) have attracted increasing attention in recent years because of their numerous applications in ocean monitoring, resource discovery and tactical surveillance. However, the design of reliable and efficient transmission and routing protocols is a challenge due to the low acoustic propagation speed and complex channel environment in UWSNs. In this paper, we propose a novel cross-layer routing protocol based on network coding (NCRP) for UWSNs, which utilizes network coding and cross-layer design to greedily forward data packets to sink nodes efficiently. The proposed NCRP takes full advantages of multicast transmission and decode packets jointly with encoded packets received from multiple potential nodes in the entire network. The transmission power is optimized in our design to extend the life cycle of the network. Moreover, we design a real-time routing maintenance protocol to update the route when detecting inefficient relay nodes. Substantial simulations in underwater environment by Network Simulator 3 (NS-3) show that NCRP significantly improves the network performance in terms of energy consumption, end-to-end delay and packet delivery ratio compared with other routing protocols for UWSNs.

Evaluation of N-ratio in selecting patients for adjuvant chemoradiotherapy after d2-gastrectomy.

PubMed

Costa Junior, Wilson Luiz da; Coimbra, Felipe José Fernández; Batista, Thales Paulo; Ribeiro, Héber Salvador de Castro; Diniz, Alessandro Landskron

2013-01-01

Whether adjuvant chemoradiotherapy may contribute to improve survival outcomes after D2-gastrectomy remains controversial. To explore the clinical utility of N-Ratio in selecting gastric cancer patients for adjuvant chemoradiotherapy after D2-gastrectomy. A retrospective cohort study was carried out on gastric cancer patients who underwent D2-gastrectomy alone or D2-gastrectomy plus adjuvant chemoradiotherapy (INT-0116 protocol) at the Hospital A. C. Camargo from September 1998 to December 2008. Statistical analysis were performed using multiple conventional methods, such as c-statistic, adjusted Cox's regression and stratified survival analysis. Our analysis involved 128 patients. According to c-statistic, the N-Ratio (i.e., as a continuous variable) presented "area under ROC curve" (AUC) of 0.713, while the number of metastatic nodes presented AUC of 0.705. After categorization, the cut-offs provide by Marchet et al. displayed the highest discriminating power - AUC value of 0.702. This N-Ratio categorization was confirmed as an independent predictor of survival using multivariate analyses. There also was a trend of better survival by adding of adjuvant chemoradiotherapy only for patients with milder degrees of lymphatic spread - 5-year survival of 23.1% vs 66.9%, respectively (HR = 0.426, 95% CI 0.150-1.202; P = 0.092). This study confirms the N-Ratio as a tool to improve the lymph node metastasis staging in gastric cancer and suggests the cut-offs provided by Marchet et al. as the best way for its categorization after a D2-gastrectomy. In these settings, the N-Ratio appears a useful tool to select patients for adjuvant chemoradiotherapy, and the benefit of adding this type of adjuvancy to D2-gastrectomy is suggested to be limited to patients with milder degrees of lymphatic spread (i.e., NR2, 10%-25%).

Freezing transition of the directed polymer in a 1+d random medium: Location of the critical temperature and unusual critical properties

NASA Astrophysics Data System (ADS)

Monthus, Cécile; Garel, Thomas

2006-07-01

In dimension d⩾3 , the directed polymer in a random medium undergoes a phase transition between a free phase at high temperature and a low-temperature disorder-dominated phase. For the latter phase, Fisher and Huse have proposed a droplet theory based on the scaling of the free-energy fluctuations ΔF(l)˜lθ at scale l . On the other hand, in related growth models belonging to the Kardar-Parisi-Zhang universality class, Forrest and Tang have found that the height-height correlation function is logarithmic at the transition. For the directed polymer model at criticality, this translates into logarithmic free-energy fluctuations ΔFTc(l)˜(lnl)σ with σ=1/2 . In this paper, we propose a droplet scaling analysis exactly at criticality based on this logarithmic scaling. Our main conclusion is that the typical correlation length ξ(T) of the low-temperature phase diverges as lnξ(T)˜[-ln(Tc-T)]1/σ˜[-ln(Tc-T)]2 , instead of the usual power law ξ(T)˜(Tc-T)-ν . Furthermore, the logarithmic dependence of ΔFTc(l) leads to the conclusion that the critical temperature Tc actually coincides with the explicit upper bound T2 derived by Derrida and co-workers, where T2 corresponds to the temperature below which the ratio ZL2¯/(ZL¯)2 diverges exponentially in L . Finally, since the Fisher-Huse droplet theory was initially introduced for the spin-glass phase, we briefly mention the similarities with and differences from the directed polymer model. If one speculates that the free energy of droplet excitations for spin glasses is also logarithmic at Tc , one obtains a logarithmic decay for the mean square correlation function at criticality, C2(r)¯˜1/(lnr)σ , instead of the usual power law 1/rd-2+η .

Real time network traffic monitoring for wireless local area networks based on compressed sensing

NASA Astrophysics Data System (ADS)

Balouchestani, Mohammadreza

2017-05-01

A wireless local area network (WLAN) is an important type of wireless networks which connotes different wireless nodes in a local area network. WLANs suffer from important problems such as network load balancing, large amount of energy, and load of sampling. This paper presents a new networking traffic approach based on Compressed Sensing (CS) for improving the quality of WLANs. The proposed architecture allows reducing Data Delay Probability (DDP) to 15%, which is a good record for WLANs. The proposed architecture is increased Data Throughput (DT) to 22 % and Signal to Noise (S/N) ratio to 17 %, which provide a good background for establishing high qualified local area networks. This architecture enables continuous data acquisition and compression of WLAN's signals that are suitable for a variety of other wireless networking applications. At the transmitter side of each wireless node, an analog-CS framework is applied at the sensing step before analog to digital converter in order to generate the compressed version of the input signal. At the receiver side of wireless node, a reconstruction algorithm is applied in order to reconstruct the original signals from the compressed signals with high probability and enough accuracy. The proposed algorithm out-performs existing algorithms by achieving a good level of Quality of Service (QoS). This ability allows reducing 15 % of Bit Error Rate (BER) at each wireless node.

The association of lymph node volume with cervical metastatic lesions in head and neck cancer patients.

PubMed

Liang, Ming-Tai; Chen, Clayton Chi-Chang; Wang, Ching-Ping; Wang, Chen-Chi; Lin, Whe-Dar; Liu, Shih-An

2009-06-01

The aim of this study was to determine if volume of cervical lymph node measured via computed tomography (CT) could differentiate metastatic from benign lesions in head and neck cancer patients. We conducted a retrospective review of chart and images in a tertiary referring center in Taiwan. Patients with head and neck cancers underwent radical, modified radical or functional neck dissection were enrolled. The CT images before operation were reassessed by a radiologist and were compared with the results of pathological examination. A total of 102 patients were included for final analyses. Most patients were male (n = 96, 94%) and average age was 50.1 years. Although the average nodal volume in patients with cervical metastases was higher than those of patients without cervical metastases, it was not an independent factor associated with cervical metastasis after controlling for other variables; however, central nodal necrosis on enhanced CT image [odds ratio (OR) 18.95, P = 0.008) and minimal axial diameter >7.5 mm (OR 6.868, P = 0.001) were independent factors correlated with cervical metastasis. Therefore, the volume of cervical lymph node measured from CT images cannot predict cervical metastases in head and neck cancer patients. Measurement of minimal axial diameter of the largest lymph node is a simple and more accurate way to predict cervical metastasis instead.

[Prognostic value of three different staging schemes based on pN, MLR and LODDS in patients with T3 esophageal cancer].

PubMed

Wang, L; Cai, L; Chen, Q; Jiang, Y H

2017-10-23

Objective: To evaluate the prognostic value of three different staging schemes based on positive lymph nodes (pN), metastatic lymph nodes ratio (MLR) and log odds of positive lymph nodes (LODDS) in patients with T3 esophageal cancer. Methods: From 2007 to 2014, clinicopathological characteristics of 905 patients who were pathologically diagnosed as T3 esophageal cancer and underwent radical esophagectomy in Zhejiang Cancer Hospital were retrospectively analyzed. Kaplan-Meier curves and Multivariate Cox proportional hazards models were used to evaluate the independent prognostic factors. The values of three lymph node staging schemes for predicting 5-year survival were analyzed by using receiver operating characteristic (ROC) curves. Results: The 1-, 3- and 5-year overall survival rates of patients with T3 esophageal cancer were 80.9%, 50.0% and 38.4%, respectively. Multivariate analysis showed that MLR stage, LODDS stage and differentiation were independent prognostic survival factors ( P <0.05 for all). ROC curves showed that the area under the curve of pN stage, MLR stage, LODDS stage was 0.607, 0.613 and 0.618, respectively. However, the differences were not statistically significant ( P >0.05). Conclusions: LODDS is an independent prognostic factor for patients with T3 esophageal cancer. The value of LODDS staging system may be superior to pN staging system for evaluating the prognosis of these patients.

Improved local and regional control with radiotherapy for Merkel cell carcinoma of the head and neck.

PubMed

Strom, Tobin; Naghavi, Arash O; Messina, Jane L; Kim, Sungjune; Torres-Roca, Javier F; Russell, Jeffery; Sondak, Vernon K; Padhya, Tapan A; Trotti, Andy M; Caudell, Jimmy J; Harrison, Louis B

2017-01-01

We hypothesized that radiotherapy (RT) would improve both local and regional control with Merkel cell carcinoma of the head and neck. A single-institution institutional review board-approved study was performed including 113 patients with nonmetastatic Merkel cell carcinoma of the head and neck. Postoperative RT was delivered to the primary tumor bed (71.7% cases) ± draining lymphatics (33.3% RT cases). Postoperative local RT was associated with improved local control (3-year actuarial local control 89.4% vs 68.1%; p = .005; Cox hazard ratio [HR] 0.18; 95% confidence interval [CI] = 0.06-0.55; p = .002). Similarly, regional RT was associated with improved regional control (3-year actuarial regional control 95.0% vs 66.7%; p = .008; Cox HR = 0.09; 95% CI = 0.01-0.69; p = .02). Regional RT played an important role for both clinical node-negative patients (3-year regional control 100% vs 44.7%; p = .03) and clinical/pathological node-positive patients (3-year regional control 90.9% vs 55.6%; p = .047). Local RT was beneficial for all patients with Merkel cell carcinoma of the head and neck, whereas regional RT was beneficial for clinical node-negative and clinical/pathological node-positive patients. © 2016 Wiley Periodicals, Inc. Head Neck 39: 48-55, 2017. © 2016 Wiley Periodicals, Inc.

On the Performance Evaluation of a MIMO-WCDMA Transmission Architecture for Building Management Systems.

PubMed

Tsampasis, Eleftherios; Gkonis, Panagiotis K; Trakadas, Panagiotis; Zahariadis, Theodοre

2018-01-08

The goal of this study was to investigate the performance of a realistic wireless sensor nodes deployment in order to support modern building management systems (BMSs). A three-floor building orientation is taken into account, where each node is equipped with a multi-antenna system while a central base station (BS) collects and processes all received information. The BS is also equipped with multiple antennas; hence, a multiple input-multiple output (MIMO) system is formulated. Due to the multiple reflections during transmission in the inner of the building, a wideband code division multiple access (WCDMA) physical layer protocol has been considered, which has already been adopted for third-generation (3G) mobile networks. Results are presented for various MIMO orientations, where the mean transmission power per node is considered as an output metric for a specific signal-to-noise ratio (SNR) requirement and number of resolvable multipath components. In the first set of presented results, the effects of multiple access interference on overall transmission power are highlighted. As the number of mobile nodes per floor or the requested transmission rate increases, MIMO systems of a higher order should be deployed in order to maintain transmission power at adequate levels. In the second set of results, a comparison is performed among transmission in diversity combining and spatial multiplexing mode, which clearly indicate that the first case is the most appropriate solution for indoor communications.

Estimation of composite hydraulic resistance in ice-covered alluvial streams

NASA Astrophysics Data System (ADS)

Ghareh Aghaji Zare, Soheil; Moore, Stephanie A.; Rennie, Colin D.; Seidou, Ousmane; Ahmari, Habib; Malenchak, Jarrod

2016-02-01

Formation, propagation, and recession of ice cover introduce a dynamic boundary layer to the top of rivers during northern winters. Ice cover affects water velocity magnitude and distribution, water level and consequently conveyance capacity of the river. In this research, total resistance, i.e., "composite resistance," is studied for a 4 month period including stable ice cover, breakup, and open water stages in Lower Nelson River (LNR), northern Manitoba, Canada. Flow and ice characteristics such as water velocity and depth and ice thickness and condition were measured continuously using acoustic techniques. An Acoustic Doppler Current Profiler (ADCP) and Shallow Water Ice Profiling Sonar (SWIPS) were installed simultaneously on a bottom mount and deployed for this purpose. Total resistance to the flow and boundary roughness are estimated using measured bulk hydraulic parameters. A novel method is developed to calculate composite resistance directly from measured under ice velocity profiles. The results of this method are compared to the measured total resistance and to the calculated composite resistance using formulae available in literature. The new technique is demonstrated to compare favorably to measured total resistance and to outperform previously available methods.

Assessing the Mechanisms Responsible for Differences between Nitrogen Requirements of Saccharomyces cerevisiae Wine Yeasts in Alcoholic Fermentation

PubMed Central

Brice, Claire; Sanchez, Isabelle; Tesnière, Catherine

2014-01-01

Nitrogen is an essential nutrient for Saccharomyces cerevisiae wine yeasts during alcoholic fermentation, and its abundance determines the fermentation rate and duration. The capacity to ferment under conditions of nitrogen deficiency differs between yeasts. A characterization of the nitrogen requirements of a set of 23 strains revealed large differences in their fermentative performances under nitrogen deficiency, and these differences reflect the nitrogen requirements of the strains. We selected and compared two groups of strains, one with low nitrogen requirements (LNRs) and the other with high nitrogen requirements (HNRs). A comparison of various physiological traits indicated that the differences are not related to the ability to store nitrogen or the protein content. No differences in protein synthesis activity were detected between strains with different nitrogen requirements. Transcriptomic analysis revealed expression patterns specific to each of the two groups of strains, with an overexpression of stress genes in HNR strains and a stronger expression of biosynthetic genes in LNR strains. Our data suggest that differences in glycolytic flux may originate from variations in nitrogen sensing and signaling under conditions of starvation. PMID:24334661

Engineering intranasal mRNA vaccines to enhance lymph node trafficking and immune responses.

PubMed

Li, Man; Li, You; Peng, Ke; Wang, Ying; Gong, Tao; Zhang, Zhirong; He, Qin; Sun, Xun

2017-12-01

Intranasal mRNA vaccination provides immediate immune protection against pandemic diseases. Recent studies have shown that diverse forms of polyethyleneimine (PEI) have potent mucosal adjuvant activity, which could significantly facilitate the delivery of intranasal mRNA vaccines. Nevertheless, optimizing the chemical structure of PEI to maximize its adjuvanticity and decrease its toxicity remains a challenge. Here we show that the chemical structure of PEI strongly influences how well nanocomplexes of PEI and mRNA migrate to the lymph nodes and elicit immune responses. Conjugating cyclodextrin (CD) with PEI600 or PEI2k yielded CP (CD-PEI) polymers with different CD/PEI ratios. We analyzed the delivery efficacy of CP600, CP2k, and PEI25k as intranasal mRNA vaccine carriers by evaluating the lymph nodes migration and immune responses. Among these polymers, CP2k/mRNA showed significantly higher in vitro transfection efficiency, stronger abilities to migrate to lymph nodes and stimulate dendritic cells maturation in vivo, which further led to potent humoral and cellular immune responses, and showed lower local and systemic toxicity than PEI25k/mRNA. These results demonstrate the potential of CD-PEI2k/mRNA nanocomplex as a self-adjuvanting vaccine delivery vehicle that traffics to lymph nodes with high efficiency. As we face outbreaks of pandemic diseases such as Zika virus, intranasal mRNA vaccination provides instant massive protection against highly variant viruses. Various polymer-based delivery systems have been successfully applied in intranasal vaccine delivery. However, the influence of molecular structure of the polymeric carriers on the lymph node trafficking and dendritic cell maturation is seldom studied for intranasal vaccination. Therefore, engineering polymer-based vaccine delivery system and elucidating the relationship between molecular structure and the intranasal delivery efficiency are essential for maximizing the immune responses. We hereby construct self-adjuvanting polymer-based intranasal mRNA vaccines to enhance lymph node trafficking and further improve immune responses. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Study of a number of biochemical indices of the blood and tissue of dogs after prolonged gamma-radiation

NASA Technical Reports Server (NTRS)

Alers, I.; Alersova, E.; Praslichka, T.; Mishurova, E.; Sedlakova, A.; Malatova, Z.; Akhunov, A. A.; Markelov, B. A.

1974-01-01

The glucose content in blood and the lipid content in serum and tissues of dogs exposed to chronic radiation for 3 and 5 years were studied. In tissues of these animals, the concentration of soluble DNA and DNA contained in DNP was studied in the spleen, lymph node (deep cervical node) and bone marrow of thigh bones. Results indicate that chronic gamma irradiation significantly changes concentrations of glucose in the blood, and that of several lipids in serum and tissues. A reduction in the concentration of DNP in tested organs reflects changes in the relative number of cells with various nuclear cytoplasmic ratios; most pronounced changes in biochemical indices occur in dogs exposed to chronic gamma radiation in doses of 125 rad per year.

Construction of optimal 3-node plate bending triangles by templates

NASA Astrophysics Data System (ADS)

Felippa, C. A.; Militello, C.

A finite element template is a parametrized algebraic form that reduces to specific finite elements by setting numerical values to the free parameters. The present study concerns Kirchhoff Plate-Bending Triangles (KPT) with 3 nodes and 9 degrees of freedom. A 37-parameter template is constructed using the Assumed Natural Deviatoric Strain (ANDES). Specialization of this template includes well known elements such as DKT and HCT. The question addressed here is: can these parameters be selected to produce high performance elements? The study is carried out by staged application of constraints on the free parameters. The first stage produces element families satisfying invariance and aspect ratio insensitivity conditions. Application of energy balance constraints produces specific elements. The performance of such elements in benchmark tests is presently under study.

a Linux PC Cluster for Lattice QCD with Exact Chiral Symmetry

NASA Astrophysics Data System (ADS)

Chiu, Ting-Wai; Hsieh, Tung-Han; Huang, Chao-Hsi; Huang, Tsung-Ren

A computational system for lattice QCD with overlap Dirac quarks is described. The platform is a home-made Linux PC cluster, built with off-the-shelf components. At present the system constitutes of 64 nodes, with each node consisting of one Pentium 4 processor (1.6/2.0/2.5 GHz), one Gbyte of PC800/1066 RDRAM, one 40/80/120 Gbyte hard disk, and a network card. The computationally intensive parts of our program are written in SSE2 codes. The speed of our system is estimated to be 70 Gflops, and its price/performance ratio is better than $1.0/Mflops for 64-bit (double precision) computations in quenched QCD. We discuss how to optimize its hardware and software for computing propagators of overlap Dirac quarks.

Matrix multiplication on the Intel Touchstone Delta

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huss-Lederman, S.; Jacobson, E.M.; Tsao, A.

1993-12-31

Matrix multiplication is a key primitive in block matrix algorithms such as those found in LAPACK. We present results from our study of matrix multiplication algorithms on the Intel Touchstone Delta, a distributed memory message-passing architecture with a two-dimensional mesh topology. We obtain an implementation that uses communication primitives highly suited to the Delta and exploits the single node assembly-coded matrix multiplication. Our algorithm is completely general, able to deal with arbitrary mesh aspect ratios and matrix dimensions, and has achieved parallel efficiency of 86% with overall peak performance in excess of 8 Gflops on 256 nodes for an 8800more » {times} 8800 matrix. We describe our algorithm design and implementation, and present performance results that demonstrate scalability and robust behavior over varying mesh topologies.« less

Primary adenocarcinoma of bladder.

PubMed

Wilson, T G; Pritchett, T R; Lieskovsky, G; Warner, N E; Skinner, D G

1991-09-01

Between April 1983 and December 1987, we have treated and followed 16 patients at the University of Southern California for adenocarcinoma of the bladder. In 10 patients, the cancer originated from a nonurachal source; all underwent radical cystectomy, bilateral pelvic lymph node dissection, and urinary diversion. The other 6 patients had an apparent urachal origin of their cancer. Half of these patients were treated with radical cystectomy and urinary diversion and half were treated initially with segmental cystectomy. Presenting characteristics (age, sex ratio, and symptoms) were similar for both groups. Three-year adjusted acturial tumor-free survival rates for the two groups were 48 percent and 31 percent, respectively. We advocate an aggressive approach of radical cystectomy, bilateral pelvic lymph node dissection, and urinary diversion for all invasive adenocarcinoma of the bladder, regardless of location.

An Adaption Broadcast Radius-Based Code Dissemination Scheme for Low Energy Wireless Sensor Networks.

PubMed

Yu, Shidi; Liu, Xiao; Liu, Anfeng; Xiong, Naixue; Cai, Zhiping; Wang, Tian

2018-05-10

Due to the Software Defined Network (SDN) technology, Wireless Sensor Networks (WSNs) are getting wider application prospects for sensor nodes that can get new functions after updating program codes. The issue of disseminating program codes to every node in the network with minimum delay and energy consumption have been formulated and investigated in the literature. The minimum-transmission broadcast (MTB) problem, which aims to reduce broadcast redundancy, has been well studied in WSNs where the broadcast radius is assumed to be fixed in the whole network. In this paper, an Adaption Broadcast Radius-based Code Dissemination (ABRCD) scheme is proposed to reduce delay and improve energy efficiency in duty cycle-based WSNs. In the ABCRD scheme, a larger broadcast radius is set in areas with more energy left, generating more optimized performance than previous schemes. Thus: (1) with a larger broadcast radius, program codes can reach the edge of network from the source in fewer hops, decreasing the number of broadcasts and at the same time, delay. (2) As the ABRCD scheme adopts a larger broadcast radius for some nodes, program codes can be transmitted to more nodes in one broadcast transmission, diminishing the number of broadcasts. (3) The larger radius in the ABRCD scheme causes more energy consumption of some transmitting nodes, but radius enlarging is only conducted in areas with an energy surplus, and energy consumption in the hot-spots can be reduced instead due to some nodes transmitting data directly to sink without forwarding by nodes in the original hot-spot, thus energy consumption can almost reach a balance and network lifetime can be prolonged. The proposed ABRCD scheme first assigns a broadcast radius, which doesn’t affect the network lifetime, to nodes having different distance to the code source, then provides an algorithm to construct a broadcast backbone. In the end, a comprehensive performance analysis and simulation result shows that the proposed ABRCD scheme shows better performance in different broadcast situations. Compared to previous schemes, the transmission delay is reduced by 41.11~78.42%, the number of broadcasts is reduced by 36.18~94.27% and the energy utilization ratio is improved up to 583.42%, while the network lifetime can be prolonged up to 274.99%.

Prognostic and predictive value of the 21-gene recurrence score assay in postmenopausal women with node-positive, oestrogen-receptor-positive breast cancer on chemotherapy: a retrospective analysis of a randomised trial.

PubMed

Albain, Kathy S; Barlow, William E; Shak, Steven; Hortobagyi, Gabriel N; Livingston, Robert B; Yeh, I-Tien; Ravdin, Peter; Bugarini, Roberto; Baehner, Frederick L; Davidson, Nancy E; Sledge, George W; Winer, Eric P; Hudis, Clifford; Ingle, James N; Perez, Edith A; Pritchard, Kathleen I; Shepherd, Lois; Gralow, Julie R; Yoshizawa, Carl; Allred, D Craig; Osborne, C Kent; Hayes, Daniel F

2010-01-01

The 21-gene recurrence score assay is prognostic for women with node-negative, oestrogen-receptor-positive breast cancer treated with tamoxifen. A low recurrence score predicts little benefit of chemotherapy. For node-positive breast cancer, we investigated whether the recurrence score was prognostic in women treated with tamoxifen alone and whether it identified those who might not benefit from anthracycline-based chemotherapy, despite higher risks of recurrence. The phase 3 trial SWOG-8814 for postmenopausal women with node-positive, oestrogen-receptor-positive breast cancer showed that chemotherapy with cyclophosphamide, doxorubicin, and fluorouracil (CAF) before tamoxifen (CAF-T) added survival benefit to treatment with tamoxifen alone. Optional tumour banking yielded specimens for determination of recurrence score by RT-PCR. In this retrospective analysis, we assessed the effect of recurrence score on disease-free survival by treatment group (tamoxifen vs CAF-T) using Cox regression, adjusting for number of positive nodes. There were 367 specimens (40% of the 927 patients in the tamoxifen and CAF-T groups) with sufficient RNA for analysis (tamoxifen, n=148; CAF-T, n=219). The recurrence score was prognostic in the tamoxifen-alone group (p=0.006; hazard ratio [HR] 2.64, 95% CI 1.33-5.27, for a 50-point difference in recurrence score). There was no benefit of CAF in patients with a low recurrence score (score <18; log-rank p=0.97; HR 1.02, 0.54-1.93), but an improvement in disease-free survival for those with a high recurrence score (score > or =31; log-rank p=0.033; HR 0.59, 0.35-1.01), after adjustment for number of positive nodes. The recurrence score by treatment interaction was significant in the first 5 years (p=0.029), with no additional prediction beyond 5 years (p=0.58), although the cumulative benefit remained at 10 years. Results were similar for overall survival and breast-cancer-specific survival. The recurrence score is prognostic for tamoxifen-treated patients with positive nodes and predicts significant benefit of CAF in tumours with a high recurrence score. A low recurrence score identifies women who might not benefit from anthracycline-based chemotherapy, despite positive nodes. National Cancer Institute and Genomic Health. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

An Adaption Broadcast Radius-Based Code Dissemination Scheme for Low Energy Wireless Sensor Networks

PubMed Central

Yu, Shidi; Liu, Xiao; Cai, Zhiping; Wang, Tian

2018-01-01

Due to the Software Defined Network (SDN) technology, Wireless Sensor Networks (WSNs) are getting wider application prospects for sensor nodes that can get new functions after updating program codes. The issue of disseminating program codes to every node in the network with minimum delay and energy consumption have been formulated and investigated in the literature. The minimum-transmission broadcast (MTB) problem, which aims to reduce broadcast redundancy, has been well studied in WSNs where the broadcast radius is assumed to be fixed in the whole network. In this paper, an Adaption Broadcast Radius-based Code Dissemination (ABRCD) scheme is proposed to reduce delay and improve energy efficiency in duty cycle-based WSNs. In the ABCRD scheme, a larger broadcast radius is set in areas with more energy left, generating more optimized performance than previous schemes. Thus: (1) with a larger broadcast radius, program codes can reach the edge of network from the source in fewer hops, decreasing the number of broadcasts and at the same time, delay. (2) As the ABRCD scheme adopts a larger broadcast radius for some nodes, program codes can be transmitted to more nodes in one broadcast transmission, diminishing the number of broadcasts. (3) The larger radius in the ABRCD scheme causes more energy consumption of some transmitting nodes, but radius enlarging is only conducted in areas with an energy surplus, and energy consumption in the hot-spots can be reduced instead due to some nodes transmitting data directly to sink without forwarding by nodes in the original hot-spot, thus energy consumption can almost reach a balance and network lifetime can be prolonged. The proposed ABRCD scheme first assigns a broadcast radius, which doesn’t affect the network lifetime, to nodes having different distance to the code source, then provides an algorithm to construct a broadcast backbone. In the end, a comprehensive performance analysis and simulation result shows that the proposed ABRCD scheme shows better performance in different broadcast situations. Compared to previous schemes, the transmission delay is reduced by 41.11~78.42%, the number of broadcasts is reduced by 36.18~94.27% and the energy utilization ratio is improved up to 583.42%, while the network lifetime can be prolonged up to 274.99%. PMID:29748525

MACS, An Instrument, and a Methodology for Simulations and Global Measurements of the Coronal Electron Temperature and the Solar Wind Velocity on the Solar Corona

NASA Technical Reports Server (NTRS)

Reginald, Nelson L.; Fisher, Richard R. (Technical Monitor)

2000-01-01

The determination of the radial and latitudinal temperature and wind profiles of the solar corona is of great importance in understanding the coronal heating mechanism and the dynamics of coronal expansion. Cram presented the theory for the formation of the K-coronal spectrum and identified two important observations. He observed the existence of temperature sensitive anti-nodes at certain wavelengths in the theoretical K-coronal spectra. The anti-nodes are separated by temperature-insensitive nodes. Remarkably, Cram showed that the wavelengths of the nodes and anti-nodes are almost independent of altitude above the solar limb. Because of these features, Cram suggested that the intensity ratios at two anti-nodes could be used as a diagnostic of the electron temperature in the K-corona. Based on this temperature diagnostic technique prescribed by Cram a slit-based spectroscopic study was performed by Ichimoto et al. on the solar corona in conjunction with the total solar eclipse of 3 Nov 1994 in Putre, Chile to determine the temperature profile of the solar corona. In this thesis Cram's theory has been extended to incorporate the role of the solar wind in the formation of the K-corona, and we have identified both temperature and wind sensitive intensity ratios. The instrument, MACS, for Multi Aperture Coronal Spectrometer, a fiber optic based spectrograph, was designed for global and simultaneous measurement of the thermal electron temperature and the solar wind velocity in the solar corona. The first ever experiment of this nature was conducted in conjunction with the total solar eclipse of 11 Aug 1999 in Elazig, Turkey. In this instrument one end of each of twenty fiber optic tips were positioned in the focal plane of the telescope in such a way that we could observe conditions simultaneously at many different latitudes and two different radial distances in the solar corona. The other ends of the fibers were vertically aligned and placed at the primary focus of the collimating lens of the spectrograph to obtain simultaneous and global spectra on the solar corona. By isolating the K-coronal spectrum from the spectrum recorded by each fiber the temperature and the wind sensitive intensity ratios were calculated to obtain simultaneous and global measurements of the thermal electron temperature and the solar wind velocity. We were successful in obtaining reliable estimates of the coronal temperature at many positions in the corona. This is the first time that simultaneous measurements of coronal temperatures have been obtained at so many points. However due to instrumental scattering encountered during observations, reliable estimates of the wind velocity turned out to be impossible to obtain. Although remedial measures were taken prior to observation, this task proved to be difficult owing to the inability to replicate the conditions expected during an eclipse in the laboratory. The full extent of the instrumental scattering was apparent only when we analyzed the observational sequence. Nevertheless the experience obtained from this very first attempt to simultaneously and globally measure both the wind velocity and the temperature on the solar corona have provided valuable information to conduct any future observations successfully.

Effect of Pathologic Tumor Response and Nodal Status on Survival in the Medical Research Council Adjuvant Gastric Infusional Chemotherapy Trial

PubMed Central

Smyth, Elizabeth C.; Fassan, Matteo; Cunningham, David; Allum, William H.; Okines, Alicia F.C.; Lampis, Andrea; Hahne, Jens C.; Rugge, Massimo; Peckitt, Clare; Nankivell, Matthew; Langley, Ruth; Ghidini, Michele; Braconi, Chiara; Wotherspoon, Andrew; Grabsch, Heike I.

2016-01-01

Purpose The Medical Research Council Adjuvant Gastric Infusional Chemotherapy (MAGIC) trial established perioperative epirubicin, cisplatin, and fluorouracil chemotherapy as a standard of care for patients with resectable esophagogastric cancer. However, identification of patients at risk for relapse remains challenging. We evaluated whether pathologic response and lymph node status after neoadjuvant chemotherapy are prognostic in patients treated in the MAGIC trial. Materials and Methods Pathologic regression was assessed in resection specimens by two independent pathologists using the Mandard tumor regression grading system (TRG). Differences in overall survival (OS) according to TRG were assessed using the Kaplan-Meier method and compared using the log-rank test. Univariate and multivariate analyses using the Cox proportional hazards method established the relationships among TRG, clinical-pathologic variables, and OS. Results Three hundred thirty resection specimens were analyzed. In chemotherapy-treated patients with a TRG of 1 or 2, median OS was not reached, whereas for patients with a TRG of 3, 4, or 5, median OS was 20.47 months. On univariate analysis, high TRG and lymph node metastases were negatively related to survival (Mandard TRG 3, 4, or 5: hazard ratio [HR], 1.94; 95% CI, 1.11 to 3.39; P = .0209; lymph node metastases: HR, 3.63; 95% CI, 1.88 to 7.0; P < .001). On multivariate analysis, only lymph node status was independently predictive of OS (HR, 3.36; 95% CI, 1.70 to 6.63; P < .001). Conclusion Lymph node metastases and not pathologic response to chemotherapy was the only independent predictor of survival after chemotherapy plus resection in the MAGIC trial. Prospective evaluation of whether omitting postoperative chemotherapy and/or switching to a noncross-resistant regimen in patients with lymph node-positive disease whose tumor did not respond to preoperative epirubicin, cisplatin, and fluorouracil may be appropriate. PMID:27298411

Surgical quality of wedge resection affects overall survival in patients with early stage non-small cell lung cancer.

PubMed

Ajmani, Gaurav S; Wang, Chi-Hsiung; Kim, Ki Wan; Howington, John A; Krantz, Seth B

2018-07-01

Very few studies have examined the quality of wedge resection in patients with non-small cell lung cancer. Using the National Cancer Database, we evaluated whether the quality of wedge resection affects overall survival in patients with early disease and how these outcomes compare with those of patients who receive stereotactic radiation. We identified 14,328 patients with cT1 to T2, N0, M0 disease treated with wedge resection (n = 10,032) or stereotactic radiation (n = 4296) from 2005 to 2013 and developed a subsample of propensity-matched wedge and radiation patients. Wedge quality was grouped as high (negative margins, >5 nodes), average (negative margins, ≤5 nodes), and poor (positive margins). Overall survival was compared between patients who received wedge resection of different quality and those who received radiation, adjusting for demographic and clinical variables. Among patients who underwent wedge resection, 94.6% had negative margins, 44.3% had 0 nodes examined, 17.1% had >5 examined, and 3.0% were nodally upstaged; 16.7% received a high-quality wedge, which was associated with a lower risk of death compared with average-quality resection (adjusted hazard ratio [aHR], 0.74; 95% confidence interval [CI], 0.67-0.82). Compared with stereotactic radiation, wedge patients with negative margins had significantly reduced hazard of death (>5 nodes: aHR, 0.50; 95% CI, 0.43-0.58; ≤5 nodes: aHR, 0.65; 95% CI, 0.60-0.70). There was no significant survival difference between margin-positive wedge and radiation. Lymph nodes examined and margins obtained are important quality metrics in wedge resection. A high-quality wedge appears to confer a significant survival advantage over lower-quality wedge and stereotactic radiation. A margin-positive wedge appears to offer no benefit compared with radiation. Copyright © 2018 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Fluorouracil, doxorubicin, and cyclophosphamide (FAC) versus FAC followed by weekly paclitaxel as adjuvant therapy for high-risk, node-negative breast cancer: results from the GEICAM/2003-02 study.

PubMed

Martín, Miguel; Ruiz, Amparo; Ruiz Borrego, Manuel; Barnadas, Agustí; González, Sonia; Calvo, Lourdes; Margelí Vila, Mireia; Antón, Antonio; Rodríguez-Lescure, Alvaro; Seguí-Palmer, Miguel Angel; Muñoz-Mateu, Montserrat; Dorca Ribugent, Joan; López-Vega, José Manuel; Jara, Carlos; Espinosa, Enrique; Mendiola Fernández, César; Andrés, Raquel; Ribelles, Nuria; Plazaola, Arrate; Sánchez-Rovira, Pedro; Salvador Bofill, Javier; Crespo, Carmen; Carabantes, Francisco J; Servitja, Sonia; Chacón, José Ignacio; Rodríguez, César A; Hernando, Blanca; Álvarez, Isabel; Carrasco, Eva; Lluch, Ana

2013-07-10

Adding taxanes to anthracycline-based adjuvant therapy improves survival outcomes of patients with node-positive breast cancer (BC). Currently, however, most patients with BC are node negative at diagnosis. The only pure node-negative study (Spanish Breast Cancer Research Group 9805) reported so far showed a docetaxel benefit but significant toxicity. Here we tested the efficacy and safety of weekly paclitaxel (wP) in node-negative patients, which is yet to be established. Patients with BC having T1-T3/N0 tumors and at least one high-risk factor for recurrence (according to St. Gallen 1998 criteria) were eligible. After primary surgery, 1,925 patients were randomly assigned to receive fluorouracil, doxorubicin, and cyclophosphamide (FAC) × 6 or FAC × 4 followed by wP × 8 (FAC-wP). The primary end point was disease-free survival (DFS) after a median follow-up of 5 years. Secondary end points included toxicity and overall survival. After a median follow-up of 63.3 months, 93% and 90.3% of patients receiving FAC-wP or FAC regimens, respectively, remained disease free (hazard ratio [HR], 0.73; 95% CI, 0.54 to 0.99; log-rank P = .04). Thirty-one patients receiving FAC-wP versus 40 patients receiving FAC died (one and seven from cardiovascular diseases, respectively; HR, 0.79; 95% CI, 0.49 to 1.26; log-rank P = .31). The most relevant grade 3 and 4 adverse events in the FAC-wP versus the FAC arm were febrile neutropenia (2.7% v 3.6%), fatigue (7.9% v 3.4%), and sensory neuropathy (5.5% v 0%). For patients with high-risk node-negative BC, the adjuvant FAC-wP regimen was associated with a small but significant improvement in DFS compared with FAC therapy, in addition to manageable toxicity, especially regarding long-term cardiac effects.

Distribution of Cervical Lymph Node Metastases From Squamous Cell Carcinoma of the Oropharynx in the Era of Risk Stratification Using Human Papillomavirus and Smoking Status.

PubMed

Amsbaugh, Mark J; Yusuf, Mehran; Cash, Elizabeth; Silverman, Craig; Wilson, Elizabeth; Bumpous, Jeffrey; Potts, Kevin; Perez, Cesar; Bert, Robert; Redman, Rebecca; Dunlap, Neal

2016-10-01

To investigate the factors contributing to the clinical presentation of oropharyngeal squamous cell carcinoma (OPSCC) in the era of risk stratification using human papilloma virus (HPV) and smoking status. All patients with OPSCC presenting to our institutional multidisciplinary clinic from January 2009 to June 2015 were reviewed from a prospective database. The patients were grouped as being at low risk, intermediate risk, and high risk in the manner described by Ang et al. Variance in clinical presentation was examined using χ(2), Kruskal-Wallis, Mann-Whitney, and logistic regression analyses. The rates of HPV/p16 positivity (P<.001), never-smoking (P=.016), and cervical lymph node metastases (P=.023) were significantly higher for patients with OPSCC of the tonsil, base of tongue (BOT), or vallecula subsites when compared with pharyngeal wall or palate subsites. Low-risk patients with tonsil, base of tongue, or vallecula primary tumors presented with nodal stage N2a at a much higher than expected frequency (P=.007), and high-risk patients presented with tumor stage T4 at a much higher than expected frequency (P=.003). Patients with BOT primary tumors who were never-smokers were less likely to have clinically involved ipsilateral neck disease than were former smokers (odds ratio 1.8; P=.038). The distribution of cervical lymph node metastases was not associated with HPV/p16 positivity, risk group, or subsite. When these data were compared with those in historical series, no significant differences were seen in the patterns of cervical lymph node metastases for patients with OPSCC. For patients with OPSCC differences in HPV status, smoking history and anatomic subsite were associated with differences in clinical presentation but not with distribution of cervical lymph node metastases. Historical series describing the patterns of cervical lymph node metastases in patients with OPSCC remain clinically relevant. Copyright © 2016 Elsevier Inc. All rights reserved.

Tumour mutation status and sites of metastasis in patients with cutaneous melanoma.

PubMed

Adler, Nikki R; Wolfe, Rory; Kelly, John W; Haydon, Andrew; McArthur, Grant A; McLean, Catriona A; Mar, Victoria J

2017-09-26

Cutaneous melanoma can metastasise haematogenously and/or lymphogenously to form satellite/in-transit, lymph node or distant metastasis. This study aimed to determine if BRAF and NRAS mutant and wild-type tumours differ in their site of first tumour metastasis and anatomical metastatic pathway. Prospective cohort of patients with a histologically confirmed primary cutaneous melanoma at three tertiary referral centres in Melbourne, Australia from 2010 to 2015. Multinomial regression determined clinical, histological and mutational factors associated with the site of first metastasis and metastatic pathway. Of 1048 patients, 306 (29%) developed metastasis over a median 4.7 year follow-up period. 73 (24%), 192 (63%) and 41 (13%) developed distant, regional lymph node and satellite/in-transit metastasis as the first site of metastasis, respectively. BRAF mutation was associated with lymph node metastasis (adjusted RRR 2.46 95% CI 1.07-5.69, P=0.04) and sentinel lymph node positivity (adjusted odds ratio [aOR] OR 1.55, 95% CI 1.14-2.10, P=0.005). BRAF mutation and NRAS mutation were associated with increased odds of developing liver metastasis (aOR 3.09, 95% CI 1.49-6.42, P=0.003; aOR 3.17, 95% CI 1.32-7.58, P=0.01) and central nervous system (CNS) metastasis (aOR 4.65, 95% CI 2.23-9.69, P<0.001; aOR 4.03, 95% CI 1.72-9.44, P=0.001). NRAS mutation was associated with lung metastasis (aOR 2.44, 95% CI 1.21-4.93, P=0.01). BRAF mutation was found to be associated with lymph node metastasis as first metastasis and sentinel lymph node positivity. BRAF and NRAS mutations were associated with CNS and liver metastasis and NRAS mutation with lung metastasis. If these findings are validated in additional prospective studies, a role for heightened visceral organ surveillance may be warranted in patients with tumours harbouring these somatic mutations.

Gene expression profiles in auricle skin as a possible additional endpoint for determination of sensitizers: A multi-endpoint evaluation of the local lymph node assay.

PubMed

Tsuchiyama, Hiromi; Maeda, Akihisa; Nakajima, Mayumi; Kitsukawa, Mika; Takahashi, Kei; Miyoshi, Tomoya; Mutsuga, Mayu; Asaoka, Yoshiji; Miyamoto, Yohei; Oshida, Keiyu

2017-10-05

The murine local lymph node assay (LLNA) is widely used to test chemicals to induce skin sensitization. Exposure of mouse auricle skin to a sensitizer results in proliferation of local lymph node T cells, which has been measured by in vivo incorporation of H 3 -methyl thymidine or 5-bromo-2'-deoxyuridine (BrdU). The stimulation index (SI), the ratio of the mean proliferation in each treated group to that in the concurrent vehicle control group, is frequently used as a regulatory-authorized endpoint for LLNA. However, some non-sensitizing irritants, such as sodium dodecyl sulfate (SDS) or methyl salicylate (MS), have been reported as false-positives by this endpoint. In search of a potential endpoint to enhance the specificity of existing endpoints, we evaluated 3 contact sensitizers; (hexyl cinnamic aldehyde [HCA], oxazolone [OXA], and 2,4-dinitrochlorobenzene [DNCB]), 1 respiratory sensitizer (toluene 2,4-diisocyanate [TDI]), and 2 non-sensitizing irritants (MS and SDS) by several endpoints in LLNA. Each test substance was applied to both ears of female CBA/Ca mice daily for 3 consecutive days. The ears and auricle lymph node cells were analyzed on day 5 for endpoints including the SI value, lymph node cell count, cytokine release from lymph node cells, and histopathological changes and gene expression profiles in auricle skin. The SI values indicated that all the test substances induced significant proliferation of lymph node cells. The lymph node cell counts showed no significant changes by the non-sensitizers assessed. The inflammatory findings of histopathology were similar among the auricle skins treated by sensitizers and irritants. Gene expression profiles of cytokines IFN-γ, IL-4, and IL-17 in auricle skin were similar to the cytokine release profiles in draining lymph node cells. In addition, the gene expression of the chemokine CXCL1 and/or CXCL2 showed that it has the potential to discriminate sensitizers and non-sensitizing irritants. Our results suggest that multi-endpoint analysis in the LLNA leads to a better determination of the sensitizing potential of test substances. We also show that the gene expression of CXCL1 and/or CXCL2, which is involved in elicitation of contact hypersensitivity (CHS), can be a possible additional endpoint for discrimination of sensitizing compounds in LLNA. Copyright © 2017 Elsevier B.V. All rights reserved.

Developing Causal Understanding with Causal Maps: The Impact of Total Links, Temporal Flow, and Lateral Position of Outcome Nodes

ERIC Educational Resources Information Center

Jeong, Allan; Lee, Woon Jee

2012-01-01

This study examined some of the methodological approaches used by students to construct causal maps in order to determine which approaches help students understand the underlying causes and causal mechanisms in a complex system. This study tested the relationship between causal understanding (ratio of root causes correctly/incorrectly identified,…

Link Scheduling Algorithm with Interference Prediction for Multiple Mobile WBANs

PubMed Central

Le, Thien T. T.

2017-01-01

As wireless body area networks (WBANs) become a key element in electronic healthcare (e-healthcare) systems, the coexistence of multiple mobile WBANs is becoming an issue. The network performance is negatively affected by the unpredictable movement of the human body. In such an environment, inter-WBAN interference can be caused by the overlapping transmission range of nearby WBANs. We propose a link scheduling algorithm with interference prediction (LSIP) for multiple mobile WBANs, which allows multiple mobile WBANs to transmit at the same time without causing inter-WBAN interference. In the LSIP, a superframe includes the contention access phase using carrier sense multiple access with collision avoidance (CSMA/CA) and the scheduled phase using time division multiple access (TDMA) for non-interfering nodes and interfering nodes, respectively. For interference prediction, we define a parameter called interference duration as the duration during which disparate WBANs interfere with each other. The Bayesian model is used to estimate and classify the interference using a signal to interference plus noise ratio (SINR) and the number of neighboring WBANs. The simulation results show that the proposed LSIP algorithm improves the packet delivery ratio and throughput significantly with acceptable delay. PMID:28956827

Staging of pelvic lymph nodes in patients with prostate cancer: Usefulness of multiple b value SE-EPI diffusion-weighted imaging on a 3.0 T MR system.

PubMed

Vallini, Valentina; Ortori, Simona; Boraschi, Piero; Manassero, Francesca; Gabelloni, Michela; Faggioni, Lorenzo; Selli, Cesare; Bartolozzi, Carlo

2016-01-01

To evaluate the usefulness of diffusion-weighted imaging (DWI) with a multiple b value SE-EPI sequence on a 3.0 T MR scanner for staging of pelvic lymph nodes in patients with prostate cancer candidate to radical prostatectomy and extended pelvic lymph node dissection (PLND). Institutional review board approval was obtained and written informed consent was taken from all enrolled subjects. A series of 26 patients with pathologically proven prostate cancer (high or intermediate risk according to D'Amico risk groups) scheduled for radical prostatectomy and PLND underwent 3 T MRI before surgery. DWI was performed using an axial respiratory-triggered spin-echo echo-planar sequence with multiple b values (500, 800, 1000, 1500 s/mm(2)) in all diffusion directions. ADC values were calculated by means of dedicated software fitting the curve obtained from the corresponding ADC for each b value. Fitted ADC measurements were performed at the level of proximal and distal external iliac, internal iliac, and obturator nodal stations bilaterally. Lymph node appearance was also assessed in terms of short axis, long-to-short axis ratio, node contour and intranodal heterogeneity of signal intensity. A total of 173 lymph nodes and 104 nodal stations were evaluated on DWI and pathologically analysed. Mean fitted ADC values were 0.79 ± 0.14 × 10(-3) mm(2)/s for metastatic lymph nodes and 1.13 ± 0.29 × 10(-3) mm(2)/s in non-metastatic ones (P < 0.0001). The cut-off for fitted ADC obtained by ROC curve analysis was 0.91 × 10(-3) mm(2)/s. A two-point-level score was assigned for each qualitative parameter, and the mean grading score was 6.09 ± 0.61 for metastastic lymph nodes and 5.42 ± 0.79 for non-metastatic ones, respectively (P = 0.001). Using a score threshold of 4 for morphological, structural, and dimensional MRI analysis and a cut--off value of 0.91 × 10(-3) mm(2)/s for fitted ADC measurements of pelvic lymph nodes, per--station sensitivity, specificity, PPV, NPV and diagnostic accuracy were 100%, 7.9%, 15.6%, 100% and 21.3%, and 84.6%, 89.5%, 57.9%, 97.1% and 88.8%, respectively. 3.0T DWI with a multiple b value SE-EPI sequence may help distinguish benign from malignant pelvic lymph nodes in patients with prostate cancer.

Sentinel node biopsy status is strongly predictive of survival in cutaneous melanoma: Extended follow-up of Oxford patients from 1998 to 2014.

PubMed

Thomson, David R; Rughani, Milap G; Kuo, Rachel; Cassell, Oliver C S

2017-10-01

Sentinel lymph node biopsy (SLNB) is widely used as a key investigatory tool for cutaneous melanoma, with results incorporated into the latest AJCC staging guidelines. We present the results of our extended follow-up of sentinel lymph node biopsy for melanoma over a sixteen-year period. Data were collected prospectively from June 1998 to December 2014 from a single tertiary skin cancer referral centre. Chi-squared analysis was used to analyse patient demographics and primary tumour pathology. Survival analysis was conducted using Cox regression models and Kaplan-Meier survival curves. Over a sixteen-year period 1527 patients underwent SLNB in 1609 basins, with 2876 nodes harvested. 347 patients (23%) had a positive biopsy. The most common primary tumour sites for males was the back (32%); women had a significantly higher number of melanomas occurring on the lower and upper limbs (45% and 26% respectively) [all p < 0.0001, Chi-squared]. Mean follow-up time was 4.9 years. Patients with a positive SLNB at diagnosis were significantly more likely to die from melanoma (subhazard ratio 5.59, p = 0.000, 95% CI 3.59-8.69). Breslow thickness and ulceration were also significant predictors of melanoma-specific mortality. For patients with a primary Breslow >4.0 mm ten-year disease free survival was 52% for SLNB negative and 26% for SLNB positive patients. For Breslow thicknesses of 2.01-4 mm these values were 66% and 32% respectively. Sentinel lymph node biopsy status is strongly predictive of survival across all thicknesses of primary cutaneous melanoma. Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Clinical significance of preoperative carcinoembryonic antigen level in patients with clinical stage IA non-small cell lung cancer.

PubMed

Maeda, Ryo; Suda, Takashi; Hachimaru, Ayumi; Tochii, Daisuke; Tochii, Sachiko; Takagi, Yasushi

2017-01-01

The objective of this study was to assess the preoperative serum carcinoembryonic antigen (CEA) level in patients with clinical stage IA non-small cell lung cancer (NSCLC) and to evaluate its clinical significance. Between January 2005 and December 2014, a total of 378 patients with clinical stage IA NSCLC underwent complete resection with systematic node dissection. The survival rate was estimated starting from the date of surgery to the date of either death or the last follow-up by the Kaplan-Meier method. Univariate analyses by log-rank tests were used to determine prognostic factors. Cox proportional hazards ratios were used to identify independent predictors of poor prognosis. Clinicopathological predictors of lymph node metastases were evaluated by logistic regression analyses. The 5-year survival rate of patients with an elevated preoperative serum CEA level was significantly lower than that of patients with a normal CEA level (75.5% vs. 87.7%; P=0.02). However, multivariate analysis did not show the preoperative serum CEA level to be an independent predictor of poor prognosis. Postoperative pathological factors, including lymphatic permeation, visceral pleural invasion, and lymph node metastases, tended to be positive in patients with an elevated preoperative serum CEA level. In addition, the CEA level was a statistically significant independent clinical predictor of lymph node metastases. The preoperative serum CEA level was not an independent predictor of poor prognosis in patients with pathological stage IA NSCLC but was an important clinical predictor of tumor invasiveness and lymph node metastases in patients with clinical stage IA NSCLC. Therefore, measurement of the preoperative serum CEA level should be considered even for patients with early-stage NSCLC.

Radiation Use and Long-Term Survival in Breast Cancer Patients With T1, T2 Primary Tumors and One to Three Positive Axillary Lymph Nodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buchholz, Thomas A.; Woodward, Wendy A.; Duan Zhigang

2008-07-15

Background: For patients with Stage II breast cancer with one to three positive lymph nodes, controversy exists about whether radiation as a component of treatment provides a survival benefit. Methods and Materials: We analyzed data from patients with Stage II breast cancer with one to three positive lymph nodes diagnosed from 1988-2002 in the Surveillance, Epidemiology, and End Results registry and compared the outcome of 12,693 patients treated with breast-conservation therapy with radiation (BCT + XRT) with the 18,902 patients treated with mastectomy without radiation (MRM w/o XRT). Results: Patients treated with BCT + XRT were younger, were more likelymore » to be treated in recent years of the study period, more commonly had T1 primary tumors, and had fewer involved nodes compared with those treated with MRM w/o XRT (p < 0.001 for all differences). The 15-year breast cancer-specific survival rate for the BCT + XRT group was 80% vs. 72% for the MRM w/o XRT group (p < 0.001). Cox regression analysis showed that MRM w/o XRT was associated with a hazard ratio for breast cancer death of 1.19 (p < 0.001) and for overall death of 1.25 (p < 0.001). The survival benefit in the BCT + XRT group was not limited to subgroups with high-risk disease features. Conclusions: Radiation use was independently associated with improved survival for patients with Stage II breast cancer with one to three positive lymph nodes. Because multivariate analyses of retrospective data cannot account for all potential biases, these data require confirmation in randomized clinical trials.« less

LBMR: Load-Balanced Multipath Routing for Wireless Data-Intensive Transmission in Real-Time Medical Monitoring

PubMed Central

Tseng, Chinyang Henry

2016-01-01

In wireless networks, low-power Zigbee is an excellent network solution for wireless medical monitoring systems. Medical monitoring generally involves transmission of a large amount of data and easily causes bottleneck problems. Although Zigbee’s AODV mesh routing provides extensible multi-hop data transmission to extend network coverage, it originally does not, and needs to support some form of load balancing mechanism to avoid bottlenecks. To guarantee a more reliable multi-hop data transmission for life-critical medical applications, we have developed a multipath solution, called Load-Balanced Multipath Routing (LBMR) to replace Zigbee’s routing mechanism. LBMR consists of three main parts: Layer Routing Construction (LRC), a Load Estimation Algorithm (LEA), and a Route Maintenance (RM) mechanism. LRC assigns nodes into different layers based on the node’s distance to the medical data gateway. Nodes can have multiple next-hops delivering medical data toward the gateway. All neighboring layer-nodes exchange flow information containing current load, which is the used by the LEA to estimate future load of next-hops to the gateway. With LBMR, nodes can choose the neighbors with the least load as the next-hops and thus can achieve load balancing and avoid bottlenecks. Furthermore, RM can detect route failures in real-time and perform route redirection to ensure routing robustness. Since LRC and LEA prevent bottlenecks while RM ensures routing fault tolerance, LBMR provides a highly reliable routing service for medical monitoring. To evaluate these accomplishments, we compare LBMR with Zigbee’s AODV and another multipath protocol, AOMDV. The simulation results demonstrate LBMR achieves better load balancing, less unreachable nodes, and better packet delivery ratio than either AODV or AOMDV. PMID:27258297

Chaotic Bohmian trajectories for stationary states

NASA Astrophysics Data System (ADS)

Cesa, Alexandre; Martin, John; Struyve, Ward

2016-09-01

In Bohmian mechanics, the nodes of the wave function play an important role in the generation of chaos. However, so far, most of the attention has been on moving nodes; little is known about the possibility of chaos in the case of stationary nodes. We address this question by considering stationary states, which provide the simplest examples of wave functions with stationary nodes. We provide examples of stationary wave functions for which there is chaos, as demonstrated by numerical computations, for one particle moving in three spatial dimensions and for two and three entangled particles in two dimensions. Our conclusion is that the motion of the nodes is not necessary for the generation of chaos. What is important is the overall complexity of the wave function. That is, if the wave function, or rather its phase, has a complex spatial variation, it will lead to complex Bohmian trajectories and hence to chaos. Another aspect of our work concerns the average Lyapunov exponent, which quantifies the overall amount of chaos. Since it is very hard to evaluate the average Lyapunov exponent analytically, which is often computed numerically, it is useful to have simple quantities that agree well with the average Lyapunov exponent. We investigate possible correlations with quantities such as the participation ratio and different measures of entanglement, for different systems and different families of stationary wave functions. We find that these quantities often tend to correlate to the amount of chaos. However, the correlation is not perfect, because, in particular, these measures do not depend on the form of the basis states used to expand the wave function, while the amount of chaos does.

Efficient and Stable Routing Algorithm Based on User Mobility and Node Density in Urban Vehicular Network

PubMed Central

Al-Mayouf, Yusor Rafid Bahar; Ismail, Mahamod; Abdullah, Nor Fadzilah; Wahab, Ainuddin Wahid Abdul; Mahdi, Omar Adil; Khan, Suleman; Choo, Kim-Kwang Raymond

2016-01-01

Vehicular ad hoc networks (VANETs) are considered an emerging technology in the industrial and educational fields. This technology is essential in the deployment of the intelligent transportation system, which is targeted to improve safety and efficiency of traffic. The implementation of VANETs can be effectively executed by transmitting data among vehicles with the use of multiple hops. However, the intrinsic characteristics of VANETs, such as its dynamic network topology and intermittent connectivity, limit data delivery. One particular challenge of this network is the possibility that the contributing node may only remain in the network for a limited time. Hence, to prevent data loss from that node, the information must reach the destination node via multi-hop routing techniques. An appropriate, efficient, and stable routing algorithm must be developed for various VANET applications to address the issues of dynamic topology and intermittent connectivity. Therefore, this paper proposes a novel routing algorithm called efficient and stable routing algorithm based on user mobility and node density (ESRA-MD). The proposed algorithm can adapt to significant changes that may occur in the urban vehicular environment. This algorithm works by selecting an optimal route on the basis of hop count and link duration for delivering data from source to destination, thereby satisfying various quality of service considerations. The validity of the proposed algorithm is investigated by its comparison with ARP-QD protocol, which works on the mechanism of optimal route finding in VANETs in urban environments. Simulation results reveal that the proposed ESRA-MD algorithm shows remarkable improvement in terms of delivery ratio, delivery delay, and communication overhead. PMID:27855165

Lymph node density as a prognostic predictor in patients with betel nut-related oral squamous cell carcinoma.

PubMed

Chang, Wei-Chin; Lin, Chun-Shu; Yang, Cheng-Yu; Lin, Chih-Kung; Chen, Yuan-Wu

2018-04-01

Lymph node metastasis in oral squamous cell carcinoma (OSCC) is a poor prognostic factor. The histopathologic stage (e.g., pN) is used to evaluate the severity of lymph node metastasis; however, the current staging system insufficiently predicts survival and recurrence. We investigated clinical outcomes and lymph node density (LND) in betel nut-chewing individuals. We retrospectively analyzed 389 betel nut-exposed patients with primary OSCC who underwent surgical resection in 2002-2015. The prognostic significance of LND was evaluated by overall survival (OS) and disease-free survival (DFS) using the Kaplan-Meier method. Kaplan-Meier analyses showed that the 5-year OS and DFS rates in all patients were 60.9 and 48.9%, respectively. Multivariate analysis showed that variables independently prognostic for OS were aged population (hazard ratio [HR] = 1.6, 95% confidence interval [95% CI] = 1.1-2.5; P = .025), and cell differentiation classification (HR = 2.4, 95% CI = 1.4-4.2; P = .002). In pathologic N-positive patients, a receiver operating characteristic (ROC) curve for OS was used and indicated the best cutoff of 0.05, and the multivariate analysis showed that LND was an independent predictor of OS (HR = 2.2, 95% CI = 1.3-3.7; P = .004). Lymph node density, at a cutoff of 0.05, was an independent predictor of OS and DFS. OS and DFS underwent multiple analyses, and LND remained significant. The pathologic N stage had no influence in the OS analysis. LND is a more reliable predictor of survival in betel nut-chewing patients for further post operation adjuvant treatment, such as reoperation or adjuvant radiotherapy.

Prognostic Significance of Tumor Size of Small Lung Adenocarcinomas Evaluated with Mediastinal Window Settings on Computed Tomography

PubMed Central

Sakao, Yukinori; Kuroda, Hiroaki; Mun, Mingyon; Uehara, Hirofumi; Motoi, Noriko; Ishikawa, Yuichi; Nakagawa, Ken; Okumura, Sakae

2014-01-01

Background We aimed to clarify that the size of the lung adenocarcinoma evaluated using mediastinal window on computed tomography is an important and useful modality for predicting invasiveness, lymph node metastasis and prognosis in small adenocarcinoma. Methods We evaluated 176 patients with small lung adenocarcinomas (diameter, 1–3 cm) who underwent standard surgical resection. Tumours were examined using computed tomography with thin section conditions (1.25 mm thick on high-resolution computed tomography) with tumour dimensions evaluated under two settings: lung window and mediastinal window. We also determined the patient age, gender, preoperative nodal status, tumour size, tumour disappearance ratio, preoperative serum carcinoembryonic antigen levels and pathological status (lymphatic vessel, vascular vessel or pleural invasion). Recurrence-free survival was used for prognosis. Results Lung window, mediastinal window, tumour disappearance ratio and preoperative nodal status were significant predictive factors for recurrence-free survival in univariate analyses. Areas under the receiver operator curves for recurrence were 0.76, 0.73 and 0.65 for mediastinal window, tumour disappearance ratio and lung window, respectively. Lung window, mediastinal window, tumour disappearance ratio, preoperative serum carcinoembryonic antigen levels and preoperative nodal status were significant predictive factors for lymph node metastasis in univariate analyses; areas under the receiver operator curves were 0.61, 0.76, 0.72 and 0.66, for lung window, mediastinal window, tumour disappearance ratio and preoperative serum carcinoembryonic antigen levels, respectively. Lung window, mediastinal window, tumour disappearance ratio, preoperative serum carcinoembryonic antigen levels and preoperative nodal status were significant factors for lymphatic vessel, vascular vessel or pleural invasion in univariate analyses; areas under the receiver operator curves were 0.60, 0.81, 0.81 and 0.65 for lung window, mediastinal window, tumour disappearance ratio and preoperative serum carcinoembryonic antigen levels, respectively. Conclusions According to the univariate analyses including a logistic regression and ROCs performed for variables with p-values of <0.05 on univariate analyses, our results suggest that measuring tumour size using mediastinal window on high-resolution computed tomography is a simple and useful preoperative prognosis modality in small adenocarcinoma. PMID:25365326

Significance and interest of dense seismic arrays for understanding the mechanics of clayey landslides: a test case of 150 nodes at Super-Sauze landslide

NASA Astrophysics Data System (ADS)

Provost, Floriane; Malet, Jean-Philippe; Hibert, Clément; Vergne, Jérôme

2017-04-01

Clayey landslides present various seismic sources generated by the slope deformation (rockfall, slidequakes, tremors, fluid transfers). However, the characterization of the micro-seismicity and the construction of advanced catalogs (classification of the seismic source, time, and location) are complex for such objects because of the variety of recorded signals, the low signal to noise ratios, the highly attenuating medium, and the small size of the object that limits the picking of the P and S-waves. A full understanding of the seismic sources is hence often difficult because of the few number of seismometers, the large distance source-to-sensor (> 50m) and because of the lack of a continous spatially distributed record of the slope deformation. Recent progress in the geophysical instrumentation allowed the deployment of a dense network of 150 ZLand nodes (Tesla Corp.) combined with a Ground-Based InSAR sensor (IDS, IBIS-FM) for a period of ca. 2 months at the Super-Sauze clayey landslide (South French Alps). The Zland nodes are vertical wireless seismometers with 12 days autonomy. Three nodes were co-located at 50 locations in the most active part of the landslide and above the main scarp with a sensor-to-sensor distance of ca. 50m and a sample frequency of 400Hz. The Ground-Based InSAR sensor was installed in front of the landslide at a distance of ca. 800m and acquired an image every 15 minutes. The seismic events are detected automatically based on their spectrogram content with Signal-to-Noise Ratio (SNR) larger than 1.5 and automatically classified using the Random Forest algorithm. The landslide endogenous sources are then located by optimization of the inter-trace correlation of the first arrivals. This experiment aims to document the deformation of the landslide by combining surface and in depth information and provides a new insight into the seismic sources interpretation. The spatial distribution of the deformation is compared to the location of the endogenous seismic events in order to analyze seismic vs. aseismic deformation.

Locoregional Tumor Extension and Preoperative Smoking are Significant Risk Factors for Early Recurrence After Esophagectomy for Cancer.

PubMed

Mantziari, Styliani; Allemann, Pierre; Winiker, Michael; Demartines, Nicolas; Schäfer, Markus

2018-07-01

Tumor recurrence during the first year after oncological esophagectomy has been reported in up to 17-66% of patients. However, little is known as to the risk factors potentially associated with this adverse outcome. The aim of this retrospective observational study was to identify clinically relevant parameters associated with early recurrence. All patients with squamous cell cancer or adenocarcinoma of the esophagus or gastroesophageal junction, operated with curative intent in our center from 2000 to 2014, were screened for this study. Univariate analysis was conducted to identify variables potentially associated with early recurrence, and clinically relevant parameters with P < 0.1 were included in multiple logistic regression. Survival analyses were conducted with the Kaplan-Meier method. Significance threshold was set at P < 0.05. Among the 164 included patients, 46 (28%) presented early recurrence. Eight patients (17.4%) had locoregional and 38 patients (82.6%) metastatic recurrence. Advanced T and N stages, lymph node capsular effraction, a high positive-to-resected lymph node ratio, positive resection margins, poor response to neoadjuvant treatment, preoperative active smoking, malnutrition and dysphagia were associated with early recurrence on a univariate level. In multivariable analysis, preoperative smoking (OR 2.76, 95% CI 1.28-6.17), pT stage (OR 1.72, 95% CI 1.18-2.58) and an increased positive-to-resected lymph node ratio (OR 6.72, 95% CI 1.08-48.51) remained independently associated with ER. Our study identified both patient- and tumor-related parameters as risk factors for early recurrence after oncological esophagectomy. Of particular interest, active smoking was significantly associated with this adverse outcome, highlighting the importance of preoperative smoking cessation.

Selective Changes in the Immune Profile of Tumor-Draining Lymph Nodes After Different Neoadjuvant Chemoradiation Regimens for Locally Advanced Cervical Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Battaglia, Alessandra; Buzzonetti, Alexia; Martinelli, Enrica

2010-04-15

Purpose: To assess how neoadjuvant chemoradiation regimens modulate the immune system state in tumor-draining lymph nodes (TDLN), in the setting of advanced cervical cancer. Methods and Materials: Tumor-draining lymph nodes of patients undergoing chemotherapy only (nonirradiated, NI-TDLN) and chemoradiation with lower-dose (39.6 Gy, LD-TDLN) and higher-dose radiation (50 Gy, HD-TDLN) were analyzed by multicolor flow cytometry. Results: Enlarging our previous data, LD-TDLN showed features overall indicative of an enhanced antitumor response as compared with NI-TDLN, namely a significant Th1 and Tc1 polarization and a lower amount of the potent CD4{sup +}Foxp3{sup +}CD25{sup high} regulatory T cell (Treg) subset identified bymore » neuropilin-1 expression. Conversely, compared with NI-TDLN, HD-TDLN showed features overall indicative of an impaired antitumor response, namely a significantly inverted CD4/CD8 cell ratio, a higher Nrp1{sup +}Treg frequency, and a higher frequency of CCR4{sup +}Treg, a Treg subset facilitated in migrating out from TDLN to suppress the immune response against distant cancer cells. Moreover, the Th1 and Tc1 polarization induced by LD radiation was lost, and there was an unfavorable tolerogenic/immunogenic dendritic cell ratio compared with LD-TDLN. Conclusions: Even minor differences in radiation dose in neoadjuvant regimens for locally advanced cervical cancer are crucial for determining the balance between a tolerogenic and an efficacious antitumor immune response in TDLN. Because most of the anticancer immune response takes place in TDLN, the present findings also emphasize the importance of chemoradiation protocols in the context of immunotherapeutic trials.« less

Accuracy of computed tomographic features in differentiating intestinal tuberculosis from Crohn's disease: a systematic review with meta-analysis.

PubMed

Kedia, Saurabh; Sharma, Raju; Sreenivas, Vishnubhatla; Madhusudhan, Kumble Seetharama; Sharma, Vishal; Bopanna, Sawan; Pratap Mouli, Venigalla; Dhingra, Rajan; Yadav, Dawesh Prakash; Makharia, Govind; Ahuja, Vineet

2017-04-01

Abdominal computed tomography (CT) can noninvasively image the entire gastrointestinal tract and assess extraintestinal features that are important in differentiating Crohn's disease (CD) and intestinal tuberculosis (ITB). The present meta-analysis pooled the results of all studies on the role of CT abdomen in differentiating between CD and ITB. We searched PubMed and Embase for all publications in English that analyzed the features differentiating between CD and ITB on abdominal CT. The features included comb sign, necrotic lymph nodes, asymmetric bowel wall thickening, skip lesions, fibrofatty proliferation, mural stratification, ileocaecal area, long segment, and left colonic involvements. Sensitivity, specificity, positive and negative likelihood ratios, and diagnostic odds ratio (DOR) were calculated for all the features. Symmetric receiver operating characteristic curve was plotted for features present in >3 studies. Heterogeneity and publication bias was assessed and sensitivity analysis was performed by excluding studies that compared features on conventional abdominal CT instead of CT enterography (CTE). We included 6 studies (4 CTE, 1 conventional abdominal CT, and 1 CTE+conventional abdominal CT) involving 417 and 195 patients with CD and ITB, respectively. Necrotic lymph nodes had the highest diagnostic accuracy (sensitivity, 23%; specificity, 100%; DOR, 30.2) for ITB diagnosis, and comb sign (sensitivity, 82%; specificity, 81%; DOR, 21.5) followed by skip lesions (sensitivity, 86%; specificity, 74%; DOR, 16.5) had the highest diagnostic accuracy for CD diagnosis. On sensitivity analysis, the diagnostic accuracy of other features excluding asymmetric bowel wall thickening remained similar. Necrotic lymph nodes and comb sign on abdominal CT had the best diagnostic accuracy in differentiating CD and ITB.

Guiding gate-etch process development using 3D surface reaction modeling for 7nm and beyond

NASA Astrophysics Data System (ADS)

Dunn, Derren; Sporre, John R.; Deshpande, Vaibhav; Oulmane, Mohamed; Gull, Ronald; Ventzek, Peter; Ranjan, Alok

2017-03-01

Increasingly, advanced process nodes such as 7nm (N7) are fundamentally 3D and require stringent control of critical dimensions over high aspect ratio features. Process integration in these nodes requires a deep understanding of complex physical mechanisms to control critical dimensions from lithography through final etch. Polysilicon gate etch processes are critical steps in several device architectures for advanced nodes that rely on self-aligned patterning approaches to gate definition. These processes are required to meet several key metrics: (a) vertical etch profiles over high aspect ratios; (b) clean gate sidewalls free of etch process residue; (c) minimal erosion of liner oxide films protecting key architectural elements such as fins; and (e) residue free corners at gate interfaces with critical device elements. In this study, we explore how hybrid modeling approaches can be used to model a multi-step finFET polysilicon gate etch process. Initial parts of the patterning process through hardmask assembly are modeled using process emulation. Important aspects of gate definition are then modeled using a particle Monte Carlo (PMC) feature scale model that incorporates surface chemical reactions.1 When necessary, species and energy flux inputs to the PMC model are derived from simulations of the etch chamber. The modeled polysilicon gate etch process consists of several steps including a hard mask breakthrough step (BT), main feature etch steps (ME), and over-etch steps (OE) that control gate profiles at the gate fin interface. An additional constraint on this etch flow is that fin spacer oxides are left intact after final profile tuning steps. A natural optimization required from these processes is to maximize vertical gate profiles while minimizing erosion of fin spacer films.2

Comparison of Three Non-Imaging Angle-Diversity Receivers as Input Sensors of Nodes for Indoor Infrared Wireless Sensor Networks: Theory and Simulation

PubMed Central

Mendoza, Beatriz R.; Rodríguez, Silvestre; Pérez-Jiménez, Rafael; Ayala, Alejandro; González, Oswaldo

2016-01-01

In general, the use of angle-diversity receivers makes it possible to reduce the impact of ambient light noise, path loss and multipath distortion, in part by exploiting the fact that they often receive the desired signal from different directions. Angle-diversity detection can be performed using a composite receiver with multiple detector elements looking in different directions. These are called non-imaging angle-diversity receivers. In this paper, a comparison of three non-imaging angle-diversity receivers as input sensors of nodes for an indoor infrared (IR) wireless sensor network is presented. The receivers considered are the conventional angle-diversity receiver (CDR), the sectored angle-diversity receiver (SDR), and the self-orienting receiver (SOR), which have been proposed or studied by research groups in Spain. To this end, the effective signal-collection area of the three receivers is modelled and a Monte-Carlo-based ray-tracing algorithm is implemented which allows us to investigate the effect on the signal to noise ratio and main IR channel parameters, such as path loss and rms delay spread, of using the three receivers in conjunction with different combination techniques in IR links operating at low bit rates. Based on the results of the simulations, we show that the use of a conventional angle-diversity receiver in conjunction with the equal-gain combining technique provides the solution with the best signal to noise ratio, the lowest computational capacity and the lowest transmitted power requirements, which comprise the main limitations for sensor nodes in an indoor infrared wireless sensor network. PMID:27428966

Clinicopathological significance of plasminogen activator inhibitor-1 promoter 4G/5G polymorphism in breast cancer: a meta-analysis.

PubMed

Lee, Ju-Han; Kim, Younghye; Choi, Jung-Woo; Kim, Young-Sik

2013-01-01

Plasminogen activator inhibitor type 1 (PAI-1) is associated with poor prognosis in breast cancer. Transcriptional expression of the PAI-1 can be controlled by PAI-1 promoter 4G/5G polymorphism. However, the significance of PAI-1 promoter 4G/5G polymorphism in breast cancer patients is contentious. To address this controversy, we conducted a meta-analysis for the relationships between PAI-1 promoter polymorphism and clinicopathological characteristics of breast cancer. Relevant published studies were identified using a search of PubMed, Embase, and the ISI Web of Science. The effect sizes of PAI-1 promoter 4G/5G polymorphism on breast cancer risk, lymph node metastasis, histologic grade, and overall survival were calculated by odds ratio (OR) or hazard ratio. The effect sizes were combined using a random-effects model. Individuals with 4G/4G genotype had a higher risk of breast cancer than those with the combined 4G/5G and 5G/5G genotypes (OR = 1.388; p = 0.031). Breast cancer patients with the 5G/5G genotype displayed lymph node metastasis more than patients with either the combined other genotypes (OR = 1.495; p = 0.027) or with the 4G/4G genotype (OR = 1.623; p = 0.018). However, the PAI-1 promoter 4G/5G polymorphism was not associated with histological grade or overall survival. PAI-1 promoter 4G/5G polymorphism is associated with a relatively increased risk of breast cancer development and lymph node metastasis. Copyright © 2013 IMSS. Published by Elsevier Inc. All rights reserved.

A decision tree model for predicting mediastinal lymph node metastasis in non-small cell lung cancer with F-18 FDG PET/CT.

PubMed

Pak, Kyoungjune; Kim, Keunyoung; Kim, Mi-Hyun; Eom, Jung Seop; Lee, Min Ki; Cho, Jeong Su; Kim, Yun Seong; Kim, Bum Soo; Kim, Seong Jang; Kim, In Joo

2018-01-01

We aimed to develop a decision tree model to improve diagnostic performance of positron emission tomography/computed tomography (PET/CT) to detect metastatic lymph nodes (LN) in non-small cell lung cancer (NSCLC). 115 patients with NSCLC were included in this study. The training dataset included 66 patients. A decision tree model was developed with 9 variables, and validated with 49 patients: short and long diameters of LNs, ratio of short and long diameters, maximum standardized uptake value (SUVmax) of LN, mean hounsfield unit, ratio of LN SUVmax and ascending aorta SUVmax (LN/AA), and ratio of LN SUVmax and superior vena cava SUVmax. A total of 301 LNs of 115 patients were evaluated in this study. Nodular calcification was applied as the initial imaging parameter, and LN SUVmax (≥3.95) was assessed as the second. LN/AA (≥2.92) was required to high LN SUVmax. Sensitivity was 50% for training dataset, and 40% for validation dataset. However, specificity was 99.28% for training dataset, and 96.23% for validation dataset. In conclusion, we have developed a new decision tree model for interpreting mediastinal LNs. All LNs with nodular calcification were benign, and LNs with high LN SUVmax and high LN/AA were metastatic Further studies are needed to incorporate subjective parameters and pathologic evaluations into a decision tree model to improve the test performance of PET/CT.

The Influence of Macronutrients on Splanchnic and Hepatic Lymphocytes in Aging Mice.

PubMed

Le Couteur, David G; Tay, Szun S; Solon-Biet, Samantha; Bertolino, Patrick; McMahon, Aisling C; Cogger, Victoria C; Colakoglu, Feyza; Warren, Alessandra; Holmes, Andrew J; Pichaud, Nicolas; Horan, Martin; Correa, Carolina; Melvin, Richard G; Turner, Nigel; Ballard, J William O; Ruohonen, Kari; Raubenheimer, David; Simpson, Stephen J

2015-12-01

There is a strong association between aging, diet, and immunity. The effects of macronutrients and energy intake on splanchnic and hepatic lymphocytes were studied in 15 month old mice. The mice were ad-libitum fed 1 of 25 diets varying in the ratios and amounts of protein, carbohydrate, and fat over their lifetime. Lymphocytes in liver, spleen, Peyers patches, mesenteric lymph nodes, and inguinal lymph nodes were evaluated using flow cytometry. Low protein intake reversed aging changes in splenic CD4 and CD8 T cells, CD4:CD8 T cell ratio, memory/effector CD4 T cells and naïve CD4 T cells. A similar influence of total caloric intake in these ad-libitum fed mice was not apparent. Protein intake also influenced hepatic NK cells and B cells, while protein to carbohydrate ratio influenced hepatic NKT cells. Hepatosteatosis was associated with increased energy and fat intake and changes in hepatic Tregs, effector/memory T, and NK cells. Hepatic NK cells were also associated with body fat, glucose tolerance, and leptin levels while hepatic Tregs were associated with hydrogen peroxide production by hepatic mitochondria. Dietary macronutrients, particularly protein, influence splanchnic lymphocytes in old age, with downstream associations with mitochondrial function, liver pathology, and obesity-related phenotype. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

All-Cause Mortality for Life Insurance Applicants with a History of Prostate Cancer.

PubMed

Freitas, Stephen A; MacKenzie, Ross; Wylde, David N; Roudebush, Bradley T; Bergstrom, Richard L; Holowaty, J Carl; Beckman, Margaret; Rigatti, Steven J; Gill, Stacy

2017-01-01

- To determine the all-cause mortality of life insurance applicants diagnosed with prostate cancer currently or at some time in the past. - Prostate cancer is common and a frequent cause of cancer death. Both the frequency of prostate cancer in men and its propensity for causing premature mortality require insurance company medical directors and underwriters to have a good understanding of prostate cancer-related mortality trends, patterns, and outcomes in the insured population. - Life insurance applicants with reported prostate cancer were extracted from data covering United States residents between November 2007 and November 2014. Information about these applicants was matched to the Social Security Death Master (SSDMF) file for deaths occurring from 2007 to 2011 and to another commercially available death source file (Other Death Source, ODS) for deaths occurring from 2007 to 2014 to determine vital status. Actual to Expected (A/E) mortality ratios were calculated using the Society of Actuaries 2015 Valuation Basic Table (2015VBT), select and ultimate table (age last birthday) and the 2013 US population as expected mortality ratios. All expected bases were not smoker distinct. - The study covered applicants between the ages of 45 and 75 and had approximately 405,000 person-years of exposure. Older aged applicants had a lower mortality ratio than those who were younger. Applicants 45 to 54 had the highest mortality ratios in the first year after diagnosis which steadily decreased in years 6 to 10 with an increase in the mortality ratio for those over 10 years from diagnosis. Relative mortality rate was close to unity for those with localized cancer across all age groups. The mortality ratio was 2 to 4 times greater for those with cancer in 1 positive node, and much greater with 3 positive nodes. For each time-from-diagnosis category, the relative mortality ratios compared to age were highest in the 45-54 age group. The A/E mortality ratios based on the 2015VBT were consistently 3 to 4 times that of the mortality ratios based on the 2013 US population. - The mortality patterns of insurance applicants with prostate cancer were similar to that observed in individuals with prostate cancer in the general population. Applicant age, time to diagnosis and cancer severity were the most significant variables to predict mortality.

GPU-accelerated Modeling and Element-free Reverse-time Migration with Gauss Points Partition

NASA Astrophysics Data System (ADS)

Zhen, Z.; Jia, X.

2014-12-01

Element-free method (EFM) has been applied to seismic modeling and migration. Compared with finite element method (FEM) and finite difference method (FDM), it is much cheaper and more flexible because only the information of the nodes and the boundary of the study area are required in computation. In the EFM, the number of Gauss points should be consistent with the number of model nodes; otherwise the accuracy of the intermediate coefficient matrices would be harmed. Thus when we increase the nodes of velocity model in order to obtain higher resolution, we find that the size of the computer's memory will be a bottleneck. The original EFM can deal with at most 81×81 nodes in the case of 2G memory, as tested by Jia and Hu (2006). In order to solve the problem of storage and computation efficiency, we propose a concept of Gauss points partition (GPP), and utilize the GPUs to improve the computation efficiency. Considering the characteristics of the Gaussian points, the GPP method doesn't influence the propagation of seismic wave in the velocity model. To overcome the time-consuming computation of the stiffness matrix (K) and the mass matrix (M), we also use the GPUs in our computation program. We employ the compressed sparse row (CSR) format to compress the intermediate sparse matrices and try to simplify the operations by solving the linear equations with the CULA Sparse's Conjugate Gradient (CG) solver instead of the linear sparse solver 'PARDISO'. It is observed that our strategy can significantly reduce the computational time of K and Mcompared with the algorithm based on CPU. The model tested is Marmousi model. The length of the model is 7425m and the depth is 2990m. We discretize the model with 595x298 nodes, 300x300 Gauss cells and 3x3 Gauss points in each cell. In contrast to the computational time of the conventional EFM, the GPUs-GPP approach can substantially improve the efficiency. The speedup ratio of time consumption of computing K, M is 120 and the speedup ratio time consumption of RTM is 11.5. At the same time, the accuracy of imaging is not harmed. Another advantage of the GPUs-GPP method is its easy applications in other numerical methods such as the FEM. Finally, in the GPUs-GPP method, the arrays require quite limited memory storage, which makes the method promising in dealing with large-scale 3D problems.

Thermomechanical Testing Techniques for Microcircuits.

DTIC Science & Technology

1975-05-01

nodel thermal resistances ana the thermal capacitance (Wcp) for each node were determined. In order to calculate these values , the thermophysical ...present analysis by substituting the appropriate property values for methyl alcohol in place of those for Freon. A check was then made to determine... properties were assumed: GLASS ALLOY 42 ALTJMINA Elastic Modulus, psi 7.34 x 106 22 x 106 48 x 106 Poisson’s Ratio .294

Economic evaluation of genomic test-directed chemotherapy for early-stage lymph node-positive breast cancer.

PubMed

Hall, Peter S; McCabe, Christopher; Stein, Robert C; Cameron, David

2012-01-04

Multi-parameter genomic tests identify patients with early-stage breast cancer who are likely to derive little benefit from adjuvant chemotherapy. These tests can potentially spare patients the morbidity from unnecessary chemotherapy and reduce costs. However, the costs of the test must be balanced against the health benefits and cost savings produced. This economic evaluation compared genomic test-directed chemotherapy using the Oncotype DX 21-gene assay with chemotherapy for all eligible patients with lymph node-positive, estrogen receptor-positive early-stage breast cancer. We performed a cost-utility analysis using a state transition model to calculate expected costs and benefits over the lifetime of a cohort of women with estrogen receptor-positive lymph node-positive breast cancer from a UK perspective. Recurrence rates for Oncotype DX-selected risk groups were derived from parametric survival models fitted to data from the Southwest Oncology Group 8814 trial. The primary outcome was the incremental cost-effectiveness ratio, expressed as the cost (in 2011 GBP) per quality-adjusted life-year (QALY). Confidence in the incremental cost-effectiveness ratio was expressed as a probability of cost-effectiveness and was calculated using Monte Carlo simulation. Model parameters were varied deterministically and probabilistically in sensitivity analysis. Value of information analysis was used to rank priorities for further research. The incremental cost-effectiveness ratio for Oncotype DX-directed chemotherapy using a recurrence score cutoff of 18 was £5529 (US $8852) per QALY. The probability that test-directed chemotherapy is cost-effective was 0.61 at a willingness-to-pay threshold of £30 000 per QALY. Results were sensitive to the recurrence rate, long-term anthracycline-related cardiac toxicity, quality of life, test cost, and the time horizon. The highest priority for further research identified by value of information analysis is the recurrence rate in test-selected subgroups. There is substantial uncertainty regarding the cost-effectiveness of Oncotype DX-directed chemotherapy. It is particularly important that future research studies to inform cost-effectiveness-based decisions collect long-term outcome data.

Stability of low aspect ratio inverted flags and rods in a uniform flow

NASA Astrophysics Data System (ADS)

Huertas-Cerdeira, Cecilia; Sader, John E.; Gharib, Morteza

2016-11-01

Cantilevered elastic plates and rods in an inverted configuration, where the leading edge is free to move and the trailing edge is clamped, undergo complex dynamics when subjected to a uniform flow. The stability of low aspect ratio inverted plates and rods is theoretically examined, showing that it is markedly different from that of their large aspect ratio counterpart. In the limit of zero aspect ratio, the undeflected equilibrium position is found to be stable for all wind speeds. A saddle-node bifurcation emerges at finite wind speed, giving rise to a strongly deflected stable and a weakly deflected unstable equilibria. This theory is compared to experimental measurements, where good agreement is found. This research was supported by a Grant of the Gordon and Betty Moore Foundation, the Australian Research Council Grants scheme and a "la Caixa" Fellowship Grant for Post-Graduate Studies of "la Caixa" Banking Foundation.

Classification of intelligence quotient via brainwave sub-band power ratio features and artificial neural network.

PubMed

Jahidin, A H; Megat Ali, M S A; Taib, M N; Tahir, N Md; Yassin, I M; Lias, S

2014-04-01

This paper elaborates on the novel intelligence assessment method using the brainwave sub-band power ratio features. The study focuses only on the left hemisphere brainwave in its relaxed state. Distinct intelligence quotient groups have been established earlier from the score of the Raven Progressive Matrices. Sub-band power ratios are calculated from energy spectral density of theta, alpha and beta frequency bands. Synthetic data have been generated to increase dataset from 50 to 120. The features are used as input to the artificial neural network. Subsequently, the brain behaviour model has been developed using an artificial neural network that is trained with optimized learning rate, momentum constant and hidden nodes. Findings indicate that the distinct intelligence quotient groups can be classified from the brainwave sub-band power ratios with 100% training and 88.89% testing accuracies. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Cost-Performance Parametrics for Transporting Small Packages to the Mars Vicinity

NASA Technical Reports Server (NTRS)

McCleskey, C.; Lepsch, Roger A.; Martin, J.; Popescu, M.

2015-01-01

This paper explores the costs and performance required to deliver a small-sized payload package (CubeSat-sized, for instance) to various transportation nodes en route to Mars and near-Mars destinations (such as Mars moons, Phobos and Deimos). Needed is a contemporary assessment and summary compilation of transportation metrics that factor both performance and affordability of modern and emerging delivery capabilities. The paper brings together: (a) required mass transport gear ratios in delivering payload from Earths surface to the Mars vicinity, (b) the cyclical energy required for delivery, and (c) the affordability and availability of various means of transporting material across various Earth-Moon vicinity and Near-Mars vicinity nodes relevant to Mars transportation. Examples for unit deliveries are computed and tabulated, using a CubeSat as a unit, for periodic near-Mars delivery campaign scenarios.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frayce, D.; Khayat, R.E.; Derdouri, A.

The dual reciprocity boundary element method (DRBEM) is implemented to solve three-dimensional transient heat conduction problems in the presence of arbitrary sources, typically as these problems arise in materials processing. The DRBEM has a major advantage over conventional BEM, since it avoids the computation of volume integrals. These integrals stem from transient, nonlinear, and/or source terms. Thus there is no need to discretize the inner domain, since only a number of internal points are needed for the computation. The validity of the method is assessed upon comparison with results from benchmark problems where analytical solutions exist. There is generally goodmore » agreement. Comparison against finite element results is also favorable. Calculations are carried out in order to assess the influence of the number and location of internal nodes. The influence of the ratio of the numbers of internal to boundary nodes is also examined.« less

Decoder synchronization for deep space missions

NASA Technical Reports Server (NTRS)

Statman, J. I.; Cheung, K.-M.; Chauvin, T. H.; Rabkin, J.; Belongie, M. L.

1994-01-01

The Consultative Committee for Space Data Standards (CCSDS) recommends that space communication links employ a concatenated, error-correcting, channel-coding system in which the inner code is a convolutional (7,1/2) code and the outer code is a (255,223) Reed-Solomon code. The traditional implementation is to perform the node synchronization for the Viterbi decoder and the frame synchronization for the Reed-Solomon decoder as separate, sequential operations. This article discusses a unified synchronization technique that is required for deep space missions that have data rates and signal-to-noise ratios (SNR's) that are extremely low. This technique combines frame synchronization in the bit and symbol domains and traditional accumulated-metric growth techniques to establish a joint frame and node synchronization. A variation on this technique is used for the Galileo spacecraft on its Jupiter-bound mission.

Data-Gathering Scheme Using AUVs in Large-Scale Underwater Sensor Networks: A Multihop Approach

PubMed Central

Khan, Jawaad Ullah; Cho, Ho-Shin

2016-01-01

In this paper, we propose a data-gathering scheme for hierarchical underwater sensor networks, where multiple Autonomous Underwater Vehicles (AUVs) are deployed over large-scale coverage areas. The deployed AUVs constitute an intermittently connected multihop network through inter-AUV synchronization (in this paper, synchronization means an interconnection between nodes for communication) for forwarding data to the designated sink. In such a scenario, the performance of the multihop communication depends upon the synchronization among the vehicles. The mobility parameters of the vehicles vary continuously because of the constantly changing underwater currents. The variations in the AUV mobility parameters reduce the inter-AUV synchronization frequency contributing to delays in the multihop communication. The proposed scheme improves the AUV synchronization frequency by permitting neighboring AUVs to share their status information via a pre-selected node called an agent-node at the static layer of the network. We evaluate the proposed scheme in terms of the AUV synchronization frequency, vertical delay (node→AUV), horizontal delay (AUV→AUV), end-to-end delay, and the packet loss ratio. Simulation results show that the proposed scheme significantly reduces the aforementioned delays without the synchronization time-out process employed in conventional works. PMID:27706042

Data-Gathering Scheme Using AUVs in Large-Scale Underwater Sensor Networks: A Multihop Approach.

PubMed

Khan, Jawaad Ullah; Cho, Ho-Shin

2016-09-30

In this paper, we propose a data-gathering scheme for hierarchical underwater sensor networks, where multiple Autonomous Underwater Vehicles (AUVs) are deployed over large-scale coverage areas. The deployed AUVs constitute an intermittently connected multihop network through inter-AUV synchronization (in this paper, synchronization means an interconnection between nodes for communication) for forwarding data to the designated sink. In such a scenario, the performance of the multihop communication depends upon the synchronization among the vehicles. The mobility parameters of the vehicles vary continuously because of the constantly changing underwater currents. The variations in the AUV mobility parameters reduce the inter-AUV synchronization frequency contributing to delays in the multihop communication. The proposed scheme improves the AUV synchronization frequency by permitting neighboring AUVs to share their status information via a pre-selected node called an agent-node at the static layer of the network. We evaluate the proposed scheme in terms of the AUV synchronization frequency, vertical delay (node→AUV), horizontal delay (AUV→AUV), end-to-end delay, and the packet loss ratio. Simulation results show that the proposed scheme significantly reduces the aforementioned delays without the synchronization time-out process employed in conventional works.

Epidemic spreading on evolving signed networks

NASA Astrophysics Data System (ADS)

Saeedian, M.; Azimi-Tafreshi, N.; Jafari, G. R.; Kertesz, J.

2017-02-01

Most studies of disease spreading consider the underlying social network as obtained without the contagion, though epidemic influences people's willingness to contact others: A "friendly" contact may be turned to "unfriendly" to avoid infection. We study the susceptible-infected disease-spreading model on signed networks, in which each edge is associated with a positive or negative sign representing the friendly or unfriendly relation between its end nodes. In a signed network, according to Heider's theory, edge signs evolve such that finally a state of structural balance is achieved, corresponding to no frustration in physics terms. However, the danger of infection affects the evolution of its edge signs. To describe the coupled problem of the sign evolution and disease spreading, we generalize the notion of structural balance by taking into account the state of the nodes. We introduce an energy function and carry out Monte Carlo simulations on complete networks to test the energy landscape, where we find local minima corresponding to the so-called jammed states. We study the effect of the ratio of initial friendly to unfriendly connections on the propagation of disease. The steady state can be balanced or a jammed state such that a coexistence occurs between susceptible and infected nodes in the system.

A Novel Cross-Layer Routing Protocol Based on Network Coding for Underwater Sensor Networks

PubMed Central

Wang, Hao; Wang, Shilian; Bu, Renfei; Zhang, Eryang

2017-01-01

Underwater wireless sensor networks (UWSNs) have attracted increasing attention in recent years because of their numerous applications in ocean monitoring, resource discovery and tactical surveillance. However, the design of reliable and efficient transmission and routing protocols is a challenge due to the low acoustic propagation speed and complex channel environment in UWSNs. In this paper, we propose a novel cross-layer routing protocol based on network coding (NCRP) for UWSNs, which utilizes network coding and cross-layer design to greedily forward data packets to sink nodes efficiently. The proposed NCRP takes full advantages of multicast transmission and decode packets jointly with encoded packets received from multiple potential nodes in the entire network. The transmission power is optimized in our design to extend the life cycle of the network. Moreover, we design a real-time routing maintenance protocol to update the route when detecting inefficient relay nodes. Substantial simulations in underwater environment by Network Simulator 3 (NS-3) show that NCRP significantly improves the network performance in terms of energy consumption, end-to-end delay and packet delivery ratio compared with other routing protocols for UWSNs. PMID:28786915

Axillary lymph node uptake of technetium-99m-MDP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ongseng, F.; Goldfarb, C.R.; Finestone, H.

We sought to determine the frequency and significance of axillary lymph node visualization on bone scans performed with diphosphonates. Consecutive {sup 99m}Tc-methylene diphosphonate ({sup 99m}Tc-MDP) bone scans (2435) were inspected for axillary soft-tissue uptake. In positive cases, the results of physical examination, correlative imaging studies and serial bone scans were recorded, as was the site of venipuncture. Forty-eight studies (2%) showed axillary uptake ipsilateral to the injection site. Extravasation of tracer, documented by focal activity near the injection site, was present in every case. There was no association with axillary adenopathy, mass, induration of radiographically visible calcification. On some images,more » foci adjacent to the axilla were superimposed on the rib, scapula, or humerus. The bone-to-background ratio was frequently reduced; repeat imaging after 1-2 hr usually improved osseous detail. Ipsilateral axillary lymph node visualization due to extravasation of {sup 99m}Tc-MDP is frequently associated with additional foci superimposed on osseous structures simulating pathology. Delayed skeletal uptake is common in such cases and necessitates a greater time interval between injection and imaging. 7 refs., 3 figs.« less

Performance of Low-Density Parity-Check Coded Modulation

NASA Astrophysics Data System (ADS)

Hamkins, J.

2011-02-01

This article presents the simulated performance of a family of nine AR4JA low-density parity-check (LDPC) codes when used with each of five modulations. In each case, the decoder inputs are codebit log-likelihood ratios computed from the received (noisy) modulation symbols using a general formula which applies to arbitrary modulations. Suboptimal soft-decision and hard-decision demodulators are also explored. Bit-interleaving and various mappings of bits to modulation symbols are considered. A number of subtle decoder algorithm details are shown to affect performance, especially in the error floor region. Among these are quantization dynamic range and step size, clipping degree-one variable nodes, "Jones clipping" of variable nodes, approximations of the min* function, and partial hard-limiting messages from check nodes. Using these decoder optimizations, all coded modulations simulated here are free of error floors down to codeword error rates below 10^{-6}. The purpose of generating this performance data is to aid system engineers in determining an appropriate code and modulation to use under specific power and bandwidth constraints, and to provide information needed to design a variable/adaptive coded modulation (VCM/ACM) system using the AR4JA codes. IPNPR Volume 42-185 Tagged File.txt

Joint Transmit Power Allocation and Splitting for SWIPT Aided OFDM-IDMA in Wireless Sensor Networks

PubMed Central

Li, Shanshan; Zhou, Xiaotian; Wang, Cheng-Xiang; Yuan, Dongfeng; Zhang, Wensheng

2017-01-01

In this paper, we propose to combine Orthogonal Frequency Division Multiplexing-Interleave Division Multiple Access (OFDM-IDMA) with Simultaneous Wireless Information and Power Transfer (SWIPT), resulting in SWIPT aided OFDM-IDMA scheme for power-limited sensor networks. In the proposed system, the Receive Node (RN) applies Power Splitting (PS) to coordinate the Energy Harvesting (EH) and Information Decoding (ID) process, where the harvested energy is utilized to guarantee the iterative Multi-User Detection (MUD) of IDMA to work under sufficient number of iterations. Our objective is to minimize the total transmit power of Source Node (SN), while satisfying the requirements of both minimum harvested energy and Bit Error Rate (BER) performance from individual receive nodes. We formulate such a problem as a joint power allocation and splitting one, where the iteration number of MUD is also taken into consideration as the key parameter to affect both EH and ID constraints. To solve it, a sub-optimal algorithm is proposed to determine the power profile, PS ratio and iteration number of MUD in an iterative manner. Simulation results verify that the proposed algorithm can provide significant performance improvement. PMID:28677636

Joint Transmit Power Allocation and Splitting for SWIPT Aided OFDM-IDMA in Wireless Sensor Networks.

PubMed

Li, Shanshan; Zhou, Xiaotian; Wang, Cheng-Xiang; Yuan, Dongfeng; Zhang, Wensheng

2017-07-04

In this paper, we propose to combine Orthogonal Frequency Division Multiplexing-Interleave Division Multiple Access (OFDM-IDMA) with Simultaneous Wireless Information and Power Transfer (SWIPT), resulting in SWIPT aided OFDM-IDMA scheme for power-limited sensor networks. In the proposed system, the Receive Node (RN) applies Power Splitting (PS) to coordinate the Energy Harvesting (EH) and Information Decoding (ID) process, where the harvested energy is utilized to guarantee the iterative Multi-User Detection (MUD) of IDMA to work under sufficient number of iterations. Our objective is to minimize the total transmit power of Source Node (SN), while satisfying the requirements of both minimum harvested energy and Bit Error Rate (BER) performance from individual receive nodes. We formulate such a problem as a joint power allocation and splitting one, where the iteration number of MUD is also taken into consideration as the key parameter to affect both EH and ID constraints. To solve it, a sub-optimal algorithm is proposed to determine the power profile, PS ratio and iteration number of MUD in an iterative manner. Simulation results verify that the proposed algorithm can provide significant performance improvement.

Low-frequency meandering piezoelectric vibration energy harvester.

PubMed

Berdy, David F; Srisungsitthisunti, Pornsak; Jung, Byunghoo; Xu, Xianfan; Rhoads, Jeffrey F; Peroulis, Dimitrios

2012-05-01

The design, fabrication, and characterization of a novel low-frequency meandering piezoelectric vibration energy harvester is presented. The energy harvester is designed for sensor node applications where the node targets a width-to-length aspect ratio close to 1:1 while simultaneously achieving a low resonant frequency. The measured power output and normalized power density are 118 μW and 5.02 μW/mm(3)/g(2), respectively, when excited by an acceleration magnitude of 0.2 g at 49.7 Hz. The energy harvester consists of a laser-machined meandering PZT bimorph. Two methods, strain-matched electrode (SME) and strain-matched polarization (SMP), are utilized to mitigate the voltage cancellation caused by having both positive and negative strains in the piezoelectric layer during operation at the meander's first resonant frequency. We have performed finite element analysis and experimentally demonstrated a prototype harvester with a footprint of 27 x 23 mm and a height of 6.5 mm including the tip mass. The device achieves a low resonant frequency while maintaining a form factor suitable for sensor node applications. The meandering design enables energy harvesters to harvest energy from vibration sources with frequencies less than 100 Hz within a compact footprint.

Factors Influencing Relapse-Free Survival in Merkel Cell Carcinoma of the Lower Limb-A Review of 60 Cases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poulsen, Michael, E-mail: michael_poulsen@health.qld.gov.a; Round, Caroline; Keller, Jacqui

2010-02-01

Purpose: Factors affecting relapse-free survival (RFS) in patients with Merkel cell carcinoma (MCC) of the lower limb were reviewed. Methods and Materials: The records of 60 patients from 1986 to 2005 with a diagnosis of MCC of the lower limb or buttock were retrospectively reviewed. The patients were treated with curative intent with surgery, radiation, or chemotherapy. Results: The 5-year overall survival, disease-specific survival, and RFS were 53%, 61%, and 20%, respectively. Factors influencing RFS were analyzed using univariate analysis. It appeared that recurrent disease worsened RFS (p = 0.03) and the addition of any radiotherapy improved RFS (p <0.001),more » as did radiotherapy to the inguinal nodes (p = 0.01) or primary site and inguinal nodes (p = 0.003). Age, surgical margins, and stage were not statistically significant. On multivariate analysis, the only significant factor was the addition of radiotherapy (hazard ratio = 0.51 p = 0.03). Conclusion: The addition of radiotherapy improves RFS compared with surgery alone. Elective treatment should be given to the inguinal nodes to reduce the risk of relapse.« less

Applying self-organizing map and modified radial based neural network for clustering and routing optimal path in wireless network

NASA Astrophysics Data System (ADS)

Hoomod, Haider K.; Kareem Jebur, Tuka

2018-05-01

Mobile ad hoc networks (MANETs) play a critical role in today’s wireless ad hoc network research and consist of active nodes that can be in motion freely. Because it consider very important problem in this network, we suggested proposed method based on modified radial basis function networks RBFN and Self-Organizing Map SOM. These networks can be improved by the use of clusters because of huge congestion in the whole network. In such a system, the performance of MANET is improved by splitting the whole network into various clusters using SOM. The performance of clustering is improved by the cluster head selection and number of clusters. Modified Radial Based Neural Network is very simple, adaptable and efficient method to increase the life time of nodes, packet delivery ratio and the throughput of the network will increase and connection become more useful because the optimal path has the best parameters from other paths including the best bitrate and best life link with minimum delays. Proposed routing algorithm depends on the group of factors and parameters to select the path between two points in the wireless network. The SOM clustering average time (1-10 msec for stall nodes) and (8-75 msec for mobile nodes). While the routing time range (92-510 msec).The proposed system is faster than the Dijkstra by 150-300%, and faster from the RBFNN (without modify) by 145-180%.

Clinical significance of prominent retraction clefts in invasive urothelial carcinoma.

PubMed

Shah, Tanmay S; Kaag, Matthew; Raman, Jay D; Chan, Wilson; Tran, Truc; Kunchala, Sudhir; Shuman, Lauren; DeGraff, David J; Chen, Guoli; Warrick, Joshua I

2017-03-01

Micropapillary morphology in invasive urothelial carcinoma is an established predictor of aggressive disease. It is unknown, however, if prominent retraction is associated with more aggressive disease in the absence of classic micropapillary morphology. We reviewed a retrospective series of 309 radical cystectomy specimens with clinical follow-up data and documented the presence or absence of invasive urothelial carcinoma with prominent retraction clefts, defined as invasive carcinoma with retraction involving the majority of invasive tumor nests in at least one 100× field but without classic micropapillary morphology. Invasive carcinomas with plasmacytoid, sarcomatoid, nested, and small cell morphology were excluded, as were cases without lymph node sampling. In invasive conventional urothelial carcinoma, the presence of prominent retraction clefts was associated lymph node metastasis (odds ratio 4.7, P = .0015, Fisher exact test) but not pathologic tumor stage or several other oncologic parameters (all Ps > .10). Similarly, invasive urothelial carcinoma with micropapillary morphology had lymph node metastasis more frequently than conventional urothelial carcinoma without prominent retraction clefts (P < .001, Fisher exact test), but there was no difference in pathologic tumor stage or oncologic parameters (all Ps > .10). There was no statistically significant difference in rates of lymph node metastasis between invasive urothelial carcinoma with micropapillary morphology and conventional urothelial carcinoma with prominent retraction clefts (P = .54, Fisher exact test). The findings suggest that prominent retraction in invasive urothelial carcinoma may be associated with more aggressive disease, even in the absence of classic micropapillary morphology. Copyright © 2016 Elsevier Inc. All rights reserved.

A Novel Passive Tracking Scheme Exploiting Geometric and Intercept Theorems

PubMed Central

Zhou, Biao; Sun, Chao; Ahn, Deockhyeon; Kim, Youngok

2018-01-01

Passive tracking aims to track targets without assistant devices, that is, device-free targets. Passive tracking based on Radio Frequency (RF) Tomography in wireless sensor networks has recently been addressed as an emerging field. The passive tracking scheme using geometric theorems (GTs) is one of the most popular RF Tomography schemes, because the GT-based method can effectively mitigate the demand for a high density of wireless nodes. In the GT-based tracking scheme, the tracking scenario is considered as a two-dimensional geometric topology and then geometric theorems are applied to estimate crossing points (CPs) of the device-free target on line-of-sight links (LOSLs), which reveal the target’s trajectory information in a discrete form. In this paper, we review existing GT-based tracking schemes, and then propose a novel passive tracking scheme by exploiting the Intercept Theorem (IT). To create an IT-based CP estimation scheme available in the noisy non-parallel LOSL situation, we develop the equal-ratio traverse (ERT) method. Finally, we analyze properties of three GT-based tracking algorithms and the performance of these schemes is evaluated experimentally under various trajectories, node densities, and noisy topologies. Analysis of experimental results shows that tracking schemes exploiting geometric theorems can achieve remarkable positioning accuracy even under rather a low density of wireless nodes. Moreover, the proposed IT scheme can provide generally finer tracking accuracy under even lower node density and noisier topologies, in comparison to other schemes. PMID:29562621

On the Performance Evaluation of a MIMO–WCDMA Transmission Architecture for Building Management Systems

PubMed Central

Tsampasis, Eleftherios; Gkonis, Panagiotis K.; Trakadas, Panagiotis; Zahariadis, Theodοre

2018-01-01

The goal of this study was to investigate the performance of a realistic wireless sensor nodes deployment in order to support modern building management systems (BMSs). A three-floor building orientation is taken into account, where each node is equipped with a multi-antenna system while a central base station (BS) collects and processes all received information. The BS is also equipped with multiple antennas; hence, a multiple input–multiple output (MIMO) system is formulated. Due to the multiple reflections during transmission in the inner of the building, a wideband code division multiple access (WCDMA) physical layer protocol has been considered, which has already been adopted for third-generation (3G) mobile networks. Results are presented for various MIMO orientations, where the mean transmission power per node is considered as an output metric for a specific signal-to-noise ratio (SNR) requirement and number of resolvable multipath components. In the first set of presented results, the effects of multiple access interference on overall transmission power are highlighted. As the number of mobile nodes per floor or the requested transmission rate increases, MIMO systems of a higher order should be deployed in order to maintain transmission power at adequate levels. In the second set of results, a comparison is performed among transmission in diversity combining and spatial multiplexing mode, which clearly indicate that the first case is the most appropriate solution for indoor communications. PMID:29316720

Cost-Effective Encryption-Based Autonomous Routing Protocol for Efficient and Secure Wireless Sensor Networks.

PubMed

Saleem, Kashif; Derhab, Abdelouahid; Orgun, Mehmet A; Al-Muhtadi, Jalal; Rodrigues, Joel J P C; Khalil, Mohammed Sayim; Ali Ahmed, Adel

2016-03-31

The deployment of intelligent remote surveillance systems depends on wireless sensor networks (WSNs) composed of various miniature resource-constrained wireless sensor nodes. The development of routing protocols for WSNs is a major challenge because of their severe resource constraints, ad hoc topology and dynamic nature. Among those proposed routing protocols, the biology-inspired self-organized secure autonomous routing protocol (BIOSARP) involves an artificial immune system (AIS) that requires a certain amount of time to build up knowledge of neighboring nodes. The AIS algorithm uses this knowledge to distinguish between self and non-self neighboring nodes. The knowledge-building phase is a critical period in the WSN lifespan and requires active security measures. This paper proposes an enhanced BIOSARP (E-BIOSARP) that incorporates a random key encryption mechanism in a cost-effective manner to provide active security measures in WSNs. A detailed description of E-BIOSARP is presented, followed by an extensive security and performance analysis to demonstrate its efficiency. A scenario with E-BIOSARP is implemented in network simulator 2 (ns-2) and is populated with malicious nodes for analysis. Furthermore, E-BIOSARP is compared with state-of-the-art secure routing protocols in terms of processing time, delivery ratio, energy consumption, and packet overhead. The findings show that the proposed mechanism can efficiently protect WSNs from selective forwarding, brute-force or exhaustive key search, spoofing, eavesdropping, replaying or altering of routing information, cloning, acknowledgment spoofing, HELLO flood attacks, and Sybil attacks.

Cost-Effective Encryption-Based Autonomous Routing Protocol for Efficient and Secure Wireless Sensor Networks

PubMed Central

Saleem, Kashif; Derhab, Abdelouahid; Orgun, Mehmet A.; Al-Muhtadi, Jalal; Rodrigues, Joel J. P. C.; Khalil, Mohammed Sayim; Ali Ahmed, Adel

2016-01-01

The deployment of intelligent remote surveillance systems depends on wireless sensor networks (WSNs) composed of various miniature resource-constrained wireless sensor nodes. The development of routing protocols for WSNs is a major challenge because of their severe resource constraints, ad hoc topology and dynamic nature. Among those proposed routing protocols, the biology-inspired self-organized secure autonomous routing protocol (BIOSARP) involves an artificial immune system (AIS) that requires a certain amount of time to build up knowledge of neighboring nodes. The AIS algorithm uses this knowledge to distinguish between self and non-self neighboring nodes. The knowledge-building phase is a critical period in the WSN lifespan and requires active security measures. This paper proposes an enhanced BIOSARP (E-BIOSARP) that incorporates a random key encryption mechanism in a cost-effective manner to provide active security measures in WSNs. A detailed description of E-BIOSARP is presented, followed by an extensive security and performance analysis to demonstrate its efficiency. A scenario with E-BIOSARP is implemented in network simulator 2 (ns-2) and is populated with malicious nodes for analysis. Furthermore, E-BIOSARP is compared with state-of-the-art secure routing protocols in terms of processing time, delivery ratio, energy consumption, and packet overhead. The findings show that the proposed mechanism can efficiently protect WSNs from selective forwarding, brute-force or exhaustive key search, spoofing, eavesdropping, replaying or altering of routing information, cloning, acknowledgment spoofing, HELLO flood attacks, and Sybil attacks. PMID:27043572

Coalition Game-Based Secure and Effective Clustering Communication in Vehicular Cyber-Physical System (VCPS).

PubMed

Huo, Yan; Dong, Wei; Qian, Jin; Jing, Tao

2017-02-27

In this paper, we address the low efficiency of cluster-based communication for the crossroad scenario in the Vehicular Cyber-Physical System (VCPS), which is due to the overload of the cluster head resulting from a large number of transmission bandwidth requirements. After formulating the issue as a coalition formation game, a coalition-based clustering strategy is proposed, which could converge into a Nash-stable partition to accomplish the clustering formation process. In the proposed strategy, the coalition utility is formulated by the relative velocity, relative position and the bandwidth availability ratio of vehicles among the cluster. Employing the coalition utility, the vehicles are denoted as the nodes that make the decision whether to switch to a new coalition or stay in the current coalition. Based on this, we can make full use of the bandwidth provided by cluster head under the requirement of clustering stability. Nevertheless, there exist selfish nodes duringtheclusteringformation,soastointendtobenefitfromnetworks. Thisbehaviormaydegrade the communication quality and even destroy the cluster. Thus, we also present a reputation-based incentive and penalty mechanism to stop the selfish nodes from entering clusters. Numerical simulation results show that our strategy, CG-SECC, takes on a better performance for the tradeoff between the stability and efficiency of clustering communication. Besides, a case study demonstrates that the proposed incentive and penalty mechanism can play an important role in discovering and removing malicious nodes.

Coalition Game-Based Secure and Effective Clustering Communication in Vehicular Cyber-Physical System (VCPS)

PubMed Central

Huo, Yan; Dong, Wei; Qian, Jin; Jing, Tao

2017-01-01

In this paper, we address the low efficiency of cluster-based communication for the crossroad scenario in the Vehicular Cyber-Physical System (VCPS), which is due to the overload of the cluster head resulting from a large number of transmission bandwidth requirements. After formulating the issue as a coalition formation game, a coalition-based clustering strategy is proposed, which could converge into a Nash-stable partition to accomplish the clustering formation process. In the proposed strategy, the coalition utility is formulated by the relative velocity, relative position and the bandwidth availability ratio of vehicles among the cluster. Employing the coalition utility, the vehicles are denoted as the nodes that make the decision whether to switch to a new coalition or stay in the current coalition. Based on this, we can make full use of the bandwidth provided by cluster head under the requirement of clustering stability. Nevertheless, there exist selfish nodes during the clustering formation, so as to intend to benefit from networks. This behavior may degrade the communication quality and even destroy the cluster. Thus, we also present a reputation-based incentive and penalty mechanism to stop the selfish nodes from entering clusters. Numerical simulation results show that our strategy, CG-SECC, takes on a better performance for the tradeoff between the stability and efficiency of clustering communication. Besides, a case study demonstrates that the proposed incentive and penalty mechanism can play an important role in discovering and removing malicious nodes. PMID:28264469

Delamination detection by Multi-Level Wavelet Processing of Continuous Scanning Laser Doppler Vibrometry data

NASA Astrophysics Data System (ADS)

Chiariotti, P.; Martarelli, M.; Revel, G. M.

2017-12-01

A novel non-destructive testing procedure for delamination detection based on the exploitation of the simultaneous time and spatial sampling provided by Continuous Scanning Laser Doppler Vibrometry (CSLDV) and the feature extraction capability of Multi-Level wavelet-based processing is presented in this paper. The processing procedure consists in a multi-step approach. Once the optimal mother-wavelet is selected as the one maximizing the Energy to Shannon Entropy Ratio criterion among the mother-wavelet space, a pruning operation aiming at identifying the best combination of nodes inside the full-binary tree given by Wavelet Packet Decomposition (WPD) is performed. The pruning algorithm exploits, in double step way, a measure of the randomness of the point pattern distribution on the damage map space with an analysis of the energy concentration of the wavelet coefficients on those nodes provided by the first pruning operation. A combination of the point pattern distributions provided by each node of the ensemble node set from the pruning algorithm allows for setting a Damage Reliability Index associated to the final damage map. The effectiveness of the whole approach is proven on both simulated and real test cases. A sensitivity analysis related to the influence of noise on the CSLDV signal provided to the algorithm is also discussed, showing that the processing developed is robust enough to measurement noise. The method is promising: damages are well identified on different materials and for different damage-structure varieties.

Small aspect ratio Taylor-Couette flow: onset of a very-low-frequency three-torus state.

PubMed

Lopez, Juan M; Marques, Francisco

2003-09-01

The nonlinear dynamics of Taylor-Couette flow in a small aspect ratio annulus (where the length of the cylinders is half of the annular gap between them) is investigated by numerically solving the full three-dimensional Navier-Stokes equations. The system is invariant to arbitrary rotations about the annulus axis and to a reflection about the annulus half-height, so that the symmetry group is SO(2)xZ2. In this paper, we systematically investigate primary and subsequent bifurcations of the basic state, concentrating on a parameter regime where the basic state becomes unstable via Hopf bifurcations. We derive the four distinct cases for the symmetries of the bifurcated orbit, and numerically find two of these. In the parameter regime considered, we also locate the codimension-two double Hopf bifurcation where these two Hopf bifurcations coincide. Secondary Hopf bifurcations (Neimark-Sacker bifurcations), leading to modulated rotating waves, are subsequently found and a saddle-node-infinite-period bifurcation between a stable (node) and an unstable (saddle) modulated rotating wave is located, which gives rise to a very-low-frequency three-torus. This paper provides the computed example of such a state, along with a comprehensive bifurcation sequence leading to its onset.

MACS, An Instrument and a Methodology for Simultaneous and Global Measurements of the Coronal Electron Temperature and the Solar Wind Velocity on the Solar Corona

NASA Technical Reports Server (NTRS)

Reginald, Nelson L.

2000-01-01

In Cram's theory for the formation of the K-coronal spectrum he observed the existence of temperature sensitive anti-nodes, which were separated by temperature insensitive nodes, at certain wave-lengths in the K-coronal spectrum. Cram also showed these properties were remarkably independent of altitude above the solar limb. In this thesis Cram's theory has been extended to incorporate the role of the solar wind in the formation of the K-corona, and we have identified both temperature and wind sensitive intensity ratios. The instrument, MACS, for Multi Aperture Coronal Spectrometer, a fiber optic based spectrograph, was designed for global and simultaneous measurements of the thermal electron temperature and the solar wind velocity in the solar corona. The first ever experiment of this nature was conducted in conjunction with the total solar eclipse of 11 August 1999 in Elazig, Turkey. Here twenty fiber optic tips were positioned in the focal plane of the telescope to observe simultaneously at many different latitudes and two different radial distances in the solar corona. The other ends were vertically stacked and placed at the primary focus of the spectrograph. By isolating the K-coronal spectrum from each fiber the temperature and the wind sensitive intensity ratios were calculated.

Diagnostic Accuracy of F-18 FDG PET/CT for Preoperative Lymph Node Staging in Newly Diagnosed Bladder Cancer Patients: A Systematic Review and Meta-Analysis.

PubMed

Ha, Hong Ku; Koo, Phillip J; Kim, Seong-Jang

2018-05-30

We aimed to assess the diagnostic accuracy of F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for preoperative lymph node (LN) staging in newly diagnosed bladder cancer (BC) patients through a systematic review and meta-analysis. MEDLINE, Embase, and the Cochrane Library database, from the earliest available date of indexing through June 30, 2017, were searched for studies evaluating the diagnostic performance of F-18 FDG PET/CT for preoperative LN staging in newly diagnosed BC. We determined the sensitivities and specificities across studies, calculated positive and negative likelihood ratios (LR+ and LR-), and constructed summary receiver operating characteristic curves. Across 14 studies (785 patients), the pooled sensitivity was 0.57 (95% CI: 0.49-0.64) and the pooled specificity was 0.92 (95% CI: 0.87-0.95). The LR syntheses gave an overall LR+ of 7.4 (95% CI: 4.4-12.3) and an LR- of 0.47 (95% CI: 0.39-0.56). The pooled diagnostic odds ratio was 16 (95% CI: 9-28). F-18 FDG PET/CT shows a low sensitivity and high specificity for the detection of metastatic LNs in patients with newly diagnosed BC. © 2018 S. Karger AG, Basel.

Distribution of Cervical Lymph Node Metastases From Squamous Cell Carcinoma of the Oropharynx in the Era of Risk Stratification Using Human Papillomavirus and Smoking Status

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amsbaugh, Mark J., E-mail: mjamsb01@louisville.edu; Yusuf, Mehran; Cash, Elizabeth

Purpose/Objective(s): To investigate the factors contributing to the clinical presentation of oropharyngeal squamous cell carcinoma (OPSCC) in the era of risk stratification using human papilloma virus (HPV) and smoking status. Methods and Materials: All patients with OPSCC presenting to our institutional multidisciplinary clinic from January 2009 to June 2015 were reviewed from a prospective database. The patients were grouped as being at low risk, intermediate risk, and high risk in the manner described by Ang et al. Variance in clinical presentation was examined using χ{sup 2}, Kruskal-Wallis, Mann-Whitney, and logistic regression analyses. Results: The rates of HPV/p16 positivity (P<.001), never-smoking (P=.016),more » and cervical lymph node metastases (P=.023) were significantly higher for patients with OPSCC of the tonsil, base of tongue (BOT), or vallecula subsites when compared with pharyngeal wall or palate subsites. Low-risk patients with tonsil, base of tongue, or vallecula primary tumors presented with nodal stage N2a at a much higher than expected frequency (P=.007), and high-risk patients presented with tumor stage T4 at a much higher than expected frequency (P=.003). Patients with BOT primary tumors who were never-smokers were less likely to have clinically involved ipsilateral neck disease than were former smokers (odds ratio 1.8; P=.038). The distribution of cervical lymph node metastases was not associated with HPV/p16 positivity, risk group, or subsite. When these data were compared with those in historical series, no significant differences were seen in the patterns of cervical lymph node metastases for patients with OPSCC. Conclusions: For patients with OPSCC differences in HPV status, smoking history and anatomic subsite were associated with differences in clinical presentation but not with distribution of cervical lymph node metastases. Historical series describing the patterns of cervical lymph node metastases in patients with OPSCC remain clinically relevant.« less

Proposed Lymph Node Staging System Using the International Consensus Guidelines for Lymph Node Levels Is Predictive for Nasopharyngeal Carcinoma Patients From Endemic Areas Treated With Intensity Modulated Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Wen-Fei; Sun, Ying; Mao, Yan-Ping

2013-06-01

Purpose: To propose a lymph node (N) staging system for nasopharyngeal carcinoma (NPC) based on the International Consensus Guidelines for lymph node (LN) levels and MRI-determined nodal variables. Methods and Materials: The MRI scans and medical records of 749 NPC patients receiving intensity modulated radiation therapy with or without chemotherapy were retrospectively reviewed. The prognostic significance of nodal level, laterality, maximal axial diameter, extracapsular spread, necrosis, and Union for International Cancer Control/American Joint Committee on Cancer (UICC/AJCC) size criteria were analyzed. Results: Nodal level and laterality were the only independent prognostic factors for distant failure and disease failure in multivariatemore » analysis. Compared with unilateral levels Ib, II, III, and/or Va involvement (hazard ratio [HR] 1), retropharyngeal lymph node involvement alone had a similar prognostic value (HR 0.71; 95% confidence interval [CI] 0.43-1.17; P=.17), whereas bilateral levels Ib, II, III, and/or Va involvement (HR 1.65; 95% CI 1.06-2.58; P=.03) and levels IV, Vb, and/or supraclavicular fossa involvement (HR 3.47; 95% CI 1.92-6.29; P<.01) both significantly increased the HR for distant failure. Thus we propose that the N category criteria could be revised as follows: N0, no regional LN metastasis; N1, retropharyngeal lymph node involvement, and/or unilateral levels Ib, II, III, and/or Va involvement; N2, bilateral levels Ib, II, III, and/or Va involvement; N3, levels IV, Vb, and/or supraclavicular fossa involvement. Compared with the 7th edition of the UICC/AJCC criteria, the proposed N staging system provides a more satisfactory distinction between the HRs for regional failure, distant failure, and disease failure in each N category. Conclusions: The proposed N staging system defined by the International Consensus Guidelines and laterality is predictive and practical. However, because of no measurements of the maximal nodal diameter on MRI slices, the prognostic significance of LN size needs further evaluation.« less

Utility of choline positron emission tomography/computed tomography for lymph node involvement identification in intermediate- to high-risk prostate cancer: a systematic literature review and meta-analysis.

PubMed

Evangelista, Laura; Guttilla, Andrea; Zattoni, Fabio; Muzzio, Pier Carlo; Zattoni, Filiberto

2013-06-01

Determination of tumour involvement of regional lymph nodes in patients with prostate cancer (PCa) is of key importance for the proper planning of treatment. To provide a critical overview of published reports and to perform a meta-analysis about the diagnostic performance of 18F-choline and 11C-choline positron emission tomography (PET) or PET/computed tomography (CT) in the lymph node staging of PCa. A Medline, Web of Knowledge, and Google Scholar search was carried out to select English-language articles published before January 2012 that discussed the diagnostic performance of choline PET to individualise lymph node disease at initial staging in PCa patients. Articles were included only if absolute numbers of true-positive, true-negative, false-positive, and false-negative test results were available or derivable from the text and focused on lymph node metastases. Reviews, clinical reports, and editorial articles were excluded. All complete studies were reviewed; thus qualitative and quantitative analyses were performed. From the year 2000 to January 2012, we found 18 complete articles that critically evaluated the role of choline PET and PCa at initial staging. The meta-analysis was carried out and consisted of 10 selected studies with a total of 441 patients. The meta-analysis provided the following results: pooled sensitivity 49.2% (95% confidence interval [CI], 39.9-58.4) and pooled specificity 95% (95% CI, 92-97.1). The area under the curve was 0.9446 (p<0.05). The heterogeneity ranged between 22.7% and 78.4%. The diagnostic odds ratio was 18.999 (95% CI, 7.109-50.773). Choline PET and PET/CT provide low sensitivity in the detection of lymph node metastases prior to surgery in PCa patients. A high specificity has been reported from the overall studies. Studies carried out on a larger scale with a homogeneous patient population together with the evaluation of cost effectiveness are warranted. Copyright © 2012 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Risk of secondary lymphedema in breast cancer survivors is related to serum phospholipid fatty acid desaturation.

PubMed

Ryu, Eunjung; Yim, Seung Yun; Do, Hyun Ju; Lim, Jae-Young; Yang, Eun Joo; Shin, Min-Jeong; Lee, Seung-Min

2016-09-01

Secondary lymphedema is a common irreversible side effect of breast cancer surgery. We investigated if risk of secondary lymphedema in breast cancer survivors was related to changes in serum phospholipid fatty acid composition. Study subjects were voluntarily recruited into the following three groups: breast cancer survivors who had sentinel lymph node biopsy without lymphedema (SLNB), those who had auxillary lymph node dissection without lymphedema (ALND), and those who had ALND with lymphedema (ALND + LE). Body mass index (BMI), serum lipid profiles, bioimpedance data with single-frequency bioimpedance analysis (SFBIA), and serum phospholipid compositions were analyzed and compared among the groups. BMI, serum total cholesterol (total-C), and low-density lipoprotein cholesterol (LDL-C) and SFBIA ratios increased only in the ALND + LE. High polyunsaturated fatty acids (PUFAs) and high C20:4 to C18:2 n-6 PUFAs (arachidonic acid [AA]/linoleic acid [LA]) was detected in the ALND and ALND + LE groups compared to SLNB. The ALND + LE group showed increased activity indices for delta 6 desaturase (D6D) and D5D and increased ratio of AA to eicosapentaenoic acid (AA/EPA) compared to the ALND and SLNB groups. Correlation and regression analysis indicated that D6D, D5D, and AA/EPA were associated with SFBIA ratios. We demonstrated that breast cancer survivors with lymphedema had elevated total PUFAs, fatty acid desaturase activity indices, and AA/EPA in serum phospholipids. Our findings suggested that desaturation extent of fatty acid composition might be related to the risk of secondary lymphedema in breast cancer survivors.

Prognostic significance of neutrophil-to-lymphocyte ratio in biliary tract cancers: a systematic review and meta-analysis.

PubMed

Tang, Haowen; Lu, Wenping; Li, Bingmin; Li, Chonghui; Xu, Yinzhe; Dong, Jiahong

2017-05-30

Inflammation was considered to perform crucial roles in the development and metastasis of malignancies. A heightened neutrophil-lymphocyte ratio has been described to be associated with detrimental survivals in different malignancies. Debate remains over the impact of heightened neutrophil-lymphocyte ratio on survivals in biliary tract cancer. The review evaluated the prognostic value of neutrophil-lymphocyte ratio in biliary tract cancer. MEDLINE, the Cochrane Library, EMBASE, and the Chinese SinoMed were systematically searched for relevant articles. Associations between neutrophil-lymphocyte ratio and long-term outcomes were expressed as the hazard ratios and 95% confidence intervals. The odds ratio was utilized to assess the association between neutrophil-lymphocyte ratio and clinicopathological parameters. Fourteen studies consisting of 3217 patients were analyzed: 1278 (39.73%) in the high pretreatment neutrophil-lymphocyte ratio group and 1939 (60.27%) in the low pretreatment neutrophil-lymphocyte ratio one. The results proved that heightened pretreatment neutrophil-lymphocyte ratio was significantly associated with detrimental overall survival and relapse free survival for biliary tract cancer patients. In addition, elevated neutrophil-lymphocyte ratio was positively correlated with higher carbohydrate antigen 19-9 levels, advanced TNM staging and greater lymph node involvement. This meta-analysis marked that an increased pretreatment neutrophil-lymphocyte ratio was significantly linked with detrimental long-term outcomes and clinicopathological parameters for patients with biliary tract cancer.

A two-hop based adaptive routing protocol for real-time wireless sensor networks.

PubMed

Rachamalla, Sandhya; Kancherla, Anitha Sheela

2016-01-01

One of the most important and challenging issues in wireless sensor networks (WSNs) is to optimally manage the limited energy of nodes without degrading the routing efficiency. In this paper, we propose an energy-efficient adaptive routing mechanism for WSNs, which saves energy of nodes by removing the much delayed packets without degrading the real-time performance of the used routing protocol. It uses the adaptive transmission power algorithm which is based on the attenuation of the wireless link to improve the energy efficiency. The proposed routing mechanism can be associated with any geographic routing protocol and its performance is evaluated by integrating with the well known two-hop based real-time routing protocol, PATH and the resulting protocol is energy-efficient adaptive routing protocol (EE-ARP). The EE-ARP performs well in terms of energy consumption, deadline miss ratio, packet drop and end-to-end delay.

Evolutionary Beamforming Optimization for Radio Frequency Charging in Wireless Rechargeable Sensor Networks.

PubMed

Yao, Ke-Han; Jiang, Jehn-Ruey; Tsai, Chung-Hsien; Wu, Zong-Syun

2017-08-20

This paper investigates how to efficiently charge sensor nodes in a wireless rechargeable sensor network (WRSN) with radio frequency (RF) chargers to make the network sustainable. An RF charger is assumed to be equipped with a uniform circular array (UCA) of 12 antennas with the radius λ , where λ is the RF wavelength. The UCA can steer most RF energy in a target direction to charge a specific WRSN node by the beamforming technology. Two evolutionary algorithms (EAs) using the evolution strategy (ES), namely the Evolutionary Beamforming Optimization (EBO) algorithm and the Evolutionary Beamforming Optimization Reseeding (EBO-R) algorithm, are proposed to nearly optimize the power ratio of the UCA beamforming peak side lobe (PSL) and the main lobe (ML) aimed at the given target direction. The proposed algorithms are simulated for performance evaluation and are compared with a related algorithm, called Particle Swarm Optimization Gravitational Search Algorithm-Explore (PSOGSA-Explore), to show their superiority.

Low leakage Ru-strontium titanate-Ru metal-insulator-metal capacitors for sub-20 nm technology node in dynamic random access memory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Popovici, M., E-mail: Mihaela.Ioana.Popovici@imec.be; Swerts, J.; Redolfi, A.

2014-02-24

Improved metal-insulator-metal capacitor (MIMCAP) stacks with strontium titanate (STO) as dielectric sandwiched between Ru as top and bottom electrode are shown. The Ru/STO/Ru stack demonstrates clearly its potential to reach sub-20 nm technology nodes for dynamic random access memory. Downscaling of the equivalent oxide thickness, leakage current density (J{sub g}) of the MIMCAPs, and physical thickness of the STO have been realized by control of the Sr/Ti ratio and grain size using a heterogeneous TiO{sub 2}/STO based nanolaminate stack deposition and a two-step crystallization anneal. Replacement of TiN with Ru as both top and bottom electrodes reduces the amount of electricallymore » active defects and is essential to achieve a low leakage current in the MIM capacitor.« less

Cost/Performance Ratio Achieved by Using a Commodity-Based Cluster

NASA Technical Reports Server (NTRS)

Lopez, Isaac

2001-01-01

Researchers at the NASA Glenn Research Center acquired a commodity cluster based on Intel Corporation processors to compare its performance with a traditional UNIX cluster in the execution of aeropropulsion applications. Since the cost differential of the clusters was significant, a cost/performance ratio was calculated. After executing a propulsion application on both clusters, the researchers demonstrated a 9.4 cost/performance ratio in favor of the Intel-based cluster. These researchers utilize the Aeroshark cluster as one of the primary testbeds for developing NPSS parallel application codes and system software. The Aero-shark cluster provides 64 Intel Pentium II 400-MHz processors, housed in 32 nodes. Recently, APNASA - a code developed by a Government/industry team for the design and analysis of turbomachinery systems was used for a simulation on Glenn's Aeroshark cluster.

On the duration and intensity of cumulative advantage competitions

NASA Astrophysics Data System (ADS)

Jiang, Bo; Sun, Liyuan; Figueiredo, Daniel R.; Ribeiro, Bruno; Towsley, Don

2015-11-01

Network growth can be framed as a competition for edges among nodes in the network. As with various other social and physical systems, skill (fitness) and luck (random chance) act as fundamental forces driving competition dynamics. In the context of networks, cumulative advantage (CA)—the rich-get-richer effect—is seen as a driving principle governing the edge accumulation process. However, competitions coupled with CA exhibit non-trivial behavior and little is formally known about duration and intensity of CA competitions. By isolating two nodes in an ideal CA competition, we provide a mathematical understanding of how CA exacerbates the role of luck in detriment of skill. We show, for instance, that when nodes start with few edges, an early stroke of luck can place the less skilled in the lead for an extremely long period of time, a phenomenon we call ‘struggle of the fittest’. We prove that duration of a simple skill and luck competition model exhibit power-law tails when CA is present, regardless of skill difference, which is in sharp contrast to the exponential tails when fitness is distinct but CA is absent. We also prove that competition intensity is always upper bounded by an exponential tail, irrespective of CA and skills. Thus, CA competitions can be extremely long (infinite mean, depending on fitness ratio) but almost never very intense. The theoretical results are corroborated by extensive numerical simulations. Our findings have important implications to competitions not only among nodes in networks but also in contexts that leverage socio-physical models embodying CA competitions.

Arm morbidity of axillary dissection with sentinel node biopsy versus delayed axillary dissection.

PubMed

Ballal, Helen; Hunt, Catherine; Bharat, Chrianna; Murray, Kevin; Kamyab, Roshi; Saunders, Christobel

2018-02-02

Staging of axillary lymph nodes in breast cancer is important for prognostication and planning of adjuvant therapy. The traditional practice of proceeding to axillary lymph node dissection (ALND) if sentinel lymph node biopsy (SLNB) is positive is being challenged and clinical trials are underway. For many centres, this will mean a move away from intra-operative SLNB assessment and utilization of a second procedure to perform ALND. It is sometimes perceived that a delayed ALND results in increased tissue damage and thus increased morbidity. We compared morbidity in those undergoing SLNB only, or ALND as a one- or two-stage procedure. A retrospective review of a prospectively collected institutional database was used to review rates of lymphoedema and shoulder function in women undergoing breast cancer surgery between 2008 and 2012. The overall lymphoedema rate in 745 patients was 8.2% at 12 months. There was no difference in lymphoedema rates between those undergoing immediate or delayed ALND (17.8 and 8.6%, respectively, P = 0.092). Post-operative shoulder elevation, odds ratio (OR) = 0.390, 95% confidence interval (CI) = (0.218, 0.698) and abduction, OR = 0.437 (95% CI = (0.271, 0.705)) were reduced if an ALND was performed although there was no difference between immediate or delayed. ALND remains a risk factor for post-operative morbidity. There is no increased risk of lymphoedema or shoulder function deficit with a positive SLNB and delayed ALND compared to immediate ALND. © 2018 Royal Australasian College of Surgeons.

Involved-node radiotherapy in early-stage Hodgkin's lymphoma. Definition and guidelines of the German Hodgkin Study Group (GHSG).

PubMed

Eich, Hans Theodor; Müller, Rolf-Peter; Engenhart-Cabillic, Rita; Lukas, Peter; Schmidberger, Heinz; Staar, Susanne; Willich, Normann

2008-08-01

Radiotherapy of Hodgkin's Lymphoma has evolved from extended-field to involved-field (IF) radiotherapy reducing toxicity whilst maintaining high cure rates. Recent publications recommend further reduction in the radiation field to involved-node (IN) radiotherapy; however, this concept has never been tested in a randomized trial. The German Hodgkin Study Group aims to compare it with standard IF radiotherapy in their future HD17 trial. ALL patients must be examined by the radiation oncologist before the start of chemotherapy. At that time, patients must have complete staging CT scans. For patients with IN radiotherapy, a radiation planning CT before and after chemotherapy with patients in the treatment position is recommended. Fusion techniques, allowing the overlapping of the pre- and postchemotherapy CT scans, should be used. Usage of PET-CT scans with patients in the treatment position is recommended, whenever possible. The clinical target volume encompasses the initial volume of the Lymph node(s) before chemotherapy and incorporates the initial Location and extent of the disease taking the displacement of the normal tissues into account. The margin of the planning target volume should be 2 cm in axial and 3 cm in craniocaudal direction. If necessary, it can be reduced to 1-1.5 cm. To minimize Lung and cardiac toxicity, the target definition in the mediastinum is different. The concept of IN radiotherapy has been proposed as a means to further improve the therapeutic ratio by reducing the risk of radiation-induced toxicity, including second malignancies. Field sizes wiLL further decrease compared to IF radiotherapy.

DOW-PR DOlphin and Whale Pods Routing Protocol for Underwater Wireless Sensor Networks (UWSNs).

PubMed

Wadud, Zahid; Ullah, Khadem; Hussain, Sajjad; Yang, Xiaodong; Qazi, Abdul Baseer

2018-05-12

Underwater Wireless Sensor Networks (UWSNs) have intrinsic challenges that include long propagation delays, high mobility of sensor nodes due to water currents, Doppler spread, delay variance, multipath, attenuation and geometric spreading. The existing Weighting Depth and Forwarding Area Division Depth Based Routing (WDFAD-DBR) protocol considers the weighting depth of the two hops in order to select the next Potential Forwarding Node (PFN). To improve the performance of WDFAD-DBR, we propose DOlphin and Whale Pod Routing protocol (DOW-PR). In this scheme, we divide the transmission range into a number of transmission power levels and at the same time select the next PFNs from forwarding and suppressed zones. In contrast to WDFAD-DBR, our scheme not only considers the packet upward advancement, but also takes into account the number of suppressed nodes and number of PFNs at the first and second hops. Consequently, reasonable energy reduction is observed while receiving and transmitting packets. Moreover, our scheme also considers the hops count of the PFNs from the sink. In the absence of PFNs, the proposed scheme will select the node from the suppressed region for broadcasting and thus ensures minimum loss of data. Besides this, we also propose another routing scheme (whale pod) in which multiple sinks are placed at water surface, but one sink is embedded inside the water and is physically connected with the surface sink through high bandwidth connection. Simulation results show that the proposed scheme has high Packet Delivery Ratio (PDR), low energy tax, reduced Accumulated Propagation Distance (APD) and increased the network lifetime.

DOW-PR DOlphin and Whale Pods Routing Protocol for Underwater Wireless Sensor Networks (UWSNs)

PubMed Central

Wadud, Zahid; Ullah, Khadem; Hussain, Sajjad; Yang, Xiaodong; Qazi, Abdul Baseer

2018-01-01

Underwater Wireless Sensor Networks (UWSNs) have intrinsic challenges that include long propagation delays, high mobility of sensor nodes due to water currents, Doppler spread, delay variance, multipath, attenuation and geometric spreading. The existing Weighting Depth and Forwarding Area Division Depth Based Routing (WDFAD-DBR) protocol considers the weighting depth of the two hops in order to select the next Potential Forwarding Node (PFN). To improve the performance of WDFAD-DBR, we propose DOlphin and Whale Pod Routing protocol (DOW-PR). In this scheme, we divide the transmission range into a number of transmission power levels and at the same time select the next PFNs from forwarding and suppressed zones. In contrast to WDFAD-DBR, our scheme not only considers the packet upward advancement, but also takes into account the number of suppressed nodes and number of PFNs at the first and second hops. Consequently, reasonable energy reduction is observed while receiving and transmitting packets. Moreover, our scheme also considers the hops count of the PFNs from the sink. In the absence of PFNs, the proposed scheme will select the node from the suppressed region for broadcasting and thus ensures minimum loss of data. Besides this, we also propose another routing scheme (whale pod) in which multiple sinks are placed at water surface, but one sink is embedded inside the water and is physically connected with the surface sink through high bandwidth connection. Simulation results show that the proposed scheme has high Packet Delivery Ratio (PDR), low energy tax, reduced Accumulated Propagation Distance (APD) and increased the network lifetime. PMID:29757208

Non sentinel node involvement prediction for sentinel node micrometastases in breast cancer: nomogram validation and comparison with other models.

PubMed

Houvenaeghel, Gilles; Bannier, Marie; Nos, Claude; Giard, Sylvia; Mignotte, Herve; Jacquemier, Jocelyne; Martino, Marc; Esterni, Benjamin; Belichard, Catherine; Classe, Jean-Marc; Tunon de Lara, Christine; Cohen, Monique; Payan, Raoul; Blanchot, Jerome; Rouanet, Philippe; Penault-Llorca, Frederique; Bonnier, Pascal; Fournet, Sandrine; Agostini, Aubert; Marchal, Frederique; Garbay, Jean-Remi

2012-04-01

The risk of non sentinel node (NSN) involvement varies in function of the characteristics of sentinel nodes (SN) and primary tumor. Our aim was to determine and validate a statistical tool (a nomogram) able to predict the risk of NSN involvement in case of SN micro or sub-micrometastasis of breast cancer. We have compared this monogram with other models described in the literature. We have collected data on 905 patients, then 484 other patients, to build and validate the nomogram and compare it with other published scores and nomograms. Multivariate analysis conducted on the data of the first cohort allowed us to define a nomogram based on 5 criteria: the method of SN detection (immunohistochemistry or by standard coloration with HES); the ratio of positive SN out of total removed SN; the pathologic size of the tumor; the histological type; and the presence (or not) of lympho-vascular invasion. The nomogram developed here is the only one dedicated to micrometastasis and developed on the basis of two large cohorts. The results of this statistical tool in the calculation of the risk of NSN involvement is similar to those of the MSKCC (the similarly more effective nomogram according to the literature), with a lower rate of false negatives. this nomogram is dedicated specifically to cases of SN involvement by metastasis lower or equal to 2 mm. It could be used in clinical practice in the way to omit ALND when the risk of NSN involvement is low. Copyright © 2011 Elsevier Ltd. All rights reserved.

Definition and impact of pathologic complete response on prognosis after neoadjuvant chemotherapy in various intrinsic breast cancer subtypes.

PubMed

von Minckwitz, Gunter; Untch, Michael; Blohmer, Jens-Uwe; Costa, Serban D; Eidtmann, Holger; Fasching, Peter A; Gerber, Bernd; Eiermann, Wolfgang; Hilfrich, Jörn; Huober, Jens; Jackisch, Christian; Kaufmann, Manfred; Konecny, Gottfried E; Denkert, Carsten; Nekljudova, Valentina; Mehta, Keyur; Loibl, Sibylle

2012-05-20

The exact definition of pathologic complete response (pCR) and its prognostic impact on survival in intrinsic breast cancer subtypes is uncertain. Tumor response at surgery and its association with long-term outcome of 6,377 patients with primary breast cancer receiving neoadjuvant anthracycline-taxane-based chemotherapy in seven randomized trials were analyzed. Disease-free survival (DFS) was significantly superior in patients with no invasive and no in situ residuals in breast or nodes (n = 955) compared with patients with residual ductal carcinoma in situ only (n = 309), no invasive residuals in breast but involved nodes (n = 186), only focal-invasive disease in the breast (n = 478), and gross invasive residual disease (n = 4,449; P < .001). Hazard ratios for DFS comparing patients with or without pCR were lowest when defined as no invasive and no in situ residuals (0.446) and increased monotonously when in situ residuals (0.523), no invasive breast residuals but involved nodes (0.623), and focal-invasive disease (0.727) were included in the definition. pCR was associated with improved DFS in luminal B/human epidermal growth factor receptor 2 (HER2) -negative (P = .005), HER2-positive/nonluminal (P < .001), and triple-negative (P < .001) tumors but not in luminal A (P = .39) or luminal B/HER2-positive (P = .45) breast cancer. pCR in HER2-positive (nonluminal) and triple-negative tumors was associated with excellent prognosis. pCR defined as no invasive and no in situ residuals in breast and nodes can best discriminate between patients with favorable and unfavorable outcomes. Patients with noninvasive or focal-invasive residues or involved lymph nodes should not be considered as having achieved pCR. pCR is a suitable surrogate end point for patients with luminal B/HER2-negative, HER2-positive (nonluminal), and triple-negative disease but not for those with luminal B/HER2-positive or luminal A tumors.

The Impact of Definitive Local Therapy for Lymph Node-Positive Prostate Cancer: A Population-Based Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rusthoven, Chad G., E-mail: chad.rusthoven@ucdenver.edu; Carlson, Julie A.; Waxweiler, Timothy V.

2014-04-01

Purpose: To evaluate the survival outcomes for patients with lymph node-positive, nonmetastatic prostate cancer undergoing definitive local therapy (radical prostatectomy [RP], external beam radiation therapy [EBRT], or both) versus no local therapy (NLT) in the US population in the modern prostate specific antigen (PSA) era. Methods and Materials: The Surveillance, Epidemiology, and End Results database was queried for patients with T1-4N1M0 prostate cancer diagnosed from 1995 through 2005. To allow comparisons of equivalent datasets, patients were analyzed in separate clinical (cN+) and pathologically confirmed (pN+) lymph node-positive cohorts. Kaplan-Meier overall survival (OS) and prostate cancer-specific survival (PCSS) estimates were generated,more » with accompanying univariate log-rank and multivariate Cox proportional hazards comparisons. Results: A total of 796 cN+ and 2991 pN+ patients were evaluable. Among cN+ patients, 43% underwent EBRT and 57% had NLT. Outcomes for cN+ patients favored EBRT, with 10-year OS rates of 45% versus 29% (P<.001) and PCSS rates of 67% versus 53% (P<.001). Among pN+ patients, 78% underwent local therapy (RP 57%, EBRT 10%, or both 11%) and 22% had NLT. Outcomes for pN+ also favored local therapy, with 10-year OS rates of 65% versus 42% (P<.001) and PCSS rates of 78% versus 56% (P<.001). On multivariate analysis, local therapy in both the cN+ and pN+ cohorts remained independently associated with improved OS and PCSS (all P<.001). Local therapy was associated with favorable hazard ratios across subgroups, including patients aged ≥70 years and those with multiple positive lymph nodes. Among pN+ patients, no significant differences in survival were observed between RP versus EBRT and RP with or without adjuvant EBRT. Conclusions: In this large, population-based cohort, definitive local therapy was associated with significantly improved survival in patients with lymph node-positive prostate cancer.« less

Comparison of long-term results between laparoscopy-assisted gastrectomy and open gastrectomy with D2 lymph node dissection for advanced gastric cancer.

PubMed

Hamabe, Atsushi; Omori, Takeshi; Tanaka, Koji; Nishida, Toshirou

2012-06-01

Laparoscopy-assisted gastrectomy (LAG) has been established as a low-invasive surgery for early gastric cancer. However, it remains unknown whether it is applicable also for advanced gastric cancer, mainly because the long-term results of LAG with D2 lymph node dissection for advanced gastric cancer have not been well validated compared with open gastrectomy (OG). A retrospective cohort study was performed to compare LAG and OG with D2 lymph node dissection. For this study, 167 patients (66 LAG and 101 OG patients) who underwent gastrectomy with D2 lymph node dissection for advanced gastric cancer were reviewed. Recurrence-free survival and overall survival time were estimated using Kaplan-Meier curves. Stratified log-rank statistical evaluation was used to compare the difference between the LAG and OG groups stratified by histologic type, pathologic T status, N status, and postoperative adjuvant chemotherapy. The adjusted Cox proportional hazards regression models were used to calculate the hazard ratios (HRs) of LAG. The 5-year recurrence-free survival rate was 89.6% in the LAG group and 75.8% in the OG group (nonsignificant difference; stratified log-rank statistic, 3.11; P = 0.0777). The adjusted HR of recurrence for LAG compared with OG was 0.389 [95% confidence interval (CI) 0.131-1.151]. The 5-year overall survival rate was 94.4% in the LAG group and 78.5% in the OG group (nonsignificant difference; stratified log-rank statistic, 0.4817; P = 0.4877). The adjusted HR of death for LAG compared with OG was 0.633 (95% CI 0.172-2.325). The findings show that LAG with D2 lymph node dissection is acceptable in terms of long-term results for advanced gastric cancer cases and may be applicable for advanced gastric cancer treatment.

The Impact of Axillary Lymph Node Surgery on Breast Skin Thickening During and After Radiation Therapy for Breast Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Torres, Mylin A., E-mail: matorre@emory.edu; Winship Cancer Institute, Emory University, Atlanta, Georgia; Yang, Xiaofeng

Purpose: This prospective study was conducted to determine predictors of epidermal thickening during and after whole-breast radiation therapy (XRT) using objective measurements acquired with ultrasound. Methods and Materials: After breast-conserving surgery, 70 women received a definitive course of whole-breast XRT (50 Gy plus boost). Prior to XRT, at week 6 of XRT, and 6 weeks after XRT, patients underwent objective ultrasound measurements of epidermal thickness over the lumpectomy cavity and all 4 quadrants of the treated breast. A skin thickness ratio (STRA) was then generated normalizing for corresponding measurements taken of the untreated breast. Results: Baseline measurements indicated that 87% of patientsmore » had skin thickening in the treated versus untreated breast (mean increase, 27%; SD, 0.29) prior to XRT. The STRA increased significantly by week 6 of XRT (mean, 25%; SD, 0.46) and continued to increase significantly 6 weeks after XRT (mean, 33%; SD, 0.46) above baseline measurements (P<.001 for both time points). On multivariate analysis, breast volume (P=.003) and surgical evaluation of the axilla with full lymph node dissection (P<.05) predicted for more severe changes in the STRA 6 weeks after XRT compared with baseline. STRA measurements correlated with physician ratings of skin toxicity according to Radiation Therapy Oncology Group grading criteria. Conclusions: This is one of the first studies to objectively document that lymph node surgery affects XRT-induced skin thickening in patients with breast cancer. Surgical evaluation of the axilla with complete lymph node dissection was associated with the most severe XRT-induced skin changes after XRT completion. These results may inform future studies aimed at minimizing side effects of XRT and surgery, particularly when surgical lymph node assessments may not alter breast cancer management or outcome.« less

Interaction between body mass index and hormone-receptor status as a prognostic factor in lymph-node-positive breast cancer

PubMed Central

Chung, Il Yong; Park, Yu Rang; Min, Yul Ha; Lee, Yura; Yoon, Tae In; Sohn, Guiyun; Lee, Sae Byul; Kim, Jisun; Kim, Hee Jeong; Ko, Beom Seok; Son, Byung Ho; Ahn, Sei Hyun

2017-01-01

The aim of this study was to determine the relationship between the body mass index (BMI) at a breast cancer diagnosis and various factors including the hormone-receptor, menopause, and lymph-node status, and identify if there is a specific patient subgroup for which the BMI has an effect on the breast cancer prognosis. We retrospectively analyzed the data of 8,742 patients with non-metastatic invasive breast cancer from the research database of Asan Medical Center. The overall survival (OS) and breast-cancer-specific survival (BCSS) outcomes were compared among BMI groups using the Kaplan-Meier method and Cox proportional-hazards regression models with an interaction term. There was a significant interaction between BMI and hormone-receptor status for the OS (P = 0.029), and BCSS (P = 0.013) in lymph-node-positive breast cancers. Obesity in hormone-receptor-positive breast cancer showed a poorer OS (adjusted hazard ratio [HR] = 1.51, 95% confidence interval [CI] = 0.92 to 2.48) and significantly poorer BCSS (HR = 1.80, 95% CI = 1.08 to 2.99). In contrast, a high BMI in hormone-receptor-negative breast cancer revealed a better OS (HR = 0.44, 95% CI = 0.16 to 1.19) and BCSS (HR = 0.53, 95% CI = 0.19 to 1.44). Being underweight (BMI < 18.50 kg/m2) with hormone-receptor-negative breast cancer was associated with a significantly worse OS (HR = 1.98, 95% CI = 1.00–3.95) and BCSS (HR = 2.24, 95% CI = 1.12–4.47). There was no significant interaction found between the BMI and hormone-receptor status in the lymph-node-negative setting, and BMI did not interact with the menopause status in any subgroup. In conclusion, BMI interacts with the hormone-receptor status in a lymph-node-positive setting, thereby playing a role in the prognosis of breast cancer. PMID:28248981

Six Cycles of Doxorubicin and Cyclophosphamide or Paclitaxel Are Not Superior to Four Cycles As Adjuvant Chemotherapy for Breast Cancer in Women With Zero to Three Positive Axillary Nodes: Cancer and Leukemia Group B 40101

PubMed Central

Shulman, Lawrence N.; Cirrincione, Constance T.; Berry, Donald A.; Becker, Heather P.; Perez, Edith A.; O'Regan, Ruth; Martino, Silvana; Atkins, James N.; Mayer, Erica; Schneider, Charles J.; Kimmick, Gretchen; Norton, Larry; Muss, Hyman; Winer, Eric P.; Hudis, Clifford

2012-01-01

Purpose The ideal duration of adjuvant chemotherapy for patients with lower risk primary breast cancer is not known. Cancer and Leukemia Group B trial 40101 was conducted using a phase III factorial design to define whether six cycles of a chemotherapy regimen are superior to four cycles. We also sought to determine whether paclitaxel (T) is as efficacious as doxorubicin/cyclophosphamide (AC), but with reduced toxicity. Patients and Methods Between 2002 and 2008, the study enrolled women with operable breast cancer and zero to three positive nodes. Patients were randomly assigned to either four or six cycles of either AC or T. Study stratifiers were estrogen receptor/progesterone receptor (ER/PgR), human epidermal growth factor receptor 2 (HER2), and menopausal status. After 2003, all treatment was administered in dose-dense fashion. The primary efficacy end point was relapse-free survival (RFS). Results A total of 3,171 patients were enrolled; 94% were node-negative and 6% had one to three positive nodes. At a median follow-up of 5.3 years, the 4-year RFS was 90.9% and 91.8% for six and four cycles, respectively. The adjusted hazard ratio (HR) of six to four cycles regarding RFS was 1.03 (95% CI, 0.84 to 1.28; P = .77). The 4-year OS was 95.3% and 96.3% for six and four cycles, respectively, with an HR of six to four cycles of 1.12 (95% CI, 0.84 to 1.49; P = .44). There was no interaction between treatment duration and chemotherapy regimen, ER/PgR, or HER2 status on RFS or OS. Conclusion For women with resected primary breast cancer and zero to three positive nodes, we found no evidence that extending chemotherapy regimens of AC or single-agent T from four to six cycles improves clinical outcome. PMID:22826271

A scalable PC-based parallel computer for lattice QCD

NASA Astrophysics Data System (ADS)

Fodor, Z.; Katz, S. D.; Pappa, G.

2003-05-01

A PC-based parallel computer for medium/large scale lattice QCD simulations is suggested. The Eo¨tvo¨s Univ., Inst. Theor. Phys. cluster consists of 137 Intel P4-1.7GHz nodes. Gigabit Ethernet cards are used for nearest neighbor communication in a two-dimensional mesh. The sustained performance for dynamical staggered (wilson) quarks on large lattices is around 70(110) GFlops. The exceptional price/performance ratio is below $1/Mflop.

Impact of lunar oxygen production on direct manned Mars missions

NASA Technical Reports Server (NTRS)

Young, Roy M., Jr.; Tucker, William B.

1992-01-01

A manned Mars program made up of six missions is evaluated to determine the impact of using lunar liquid oxygen (LOX) as a propellant. Two departure and return nodes, low Earth orbit and low lunar orbit, are considered, as well as two return vehicle configurations, a full 70,000-kg vehicle and a 6800-kg capsule. The cost of lunar LOX delivered to orbit is expressed as a ratio of Earth launch cost.

Evaluating a preoperative protocol that includes magnetic resonance imaging for lymph node metastasis in the Cholangiocarcinoma Screening and Care Program (CASCAP) in Thailand.

PubMed

Songthamwat, Metha; Chamadol, Nittaya; Khuntikeo, Narong; Thinkhamrop, Jadsada; Koonmee, Supinda; Chaichaya, Nathaphop; Bethony, Jeffrey; Thinkhamrop, Bandit

2017-09-20

Treatment planning especially liver resection in cholangiocarcinoma (CCA) depends on the extension of tumor and lymph node metastasis which is included as a key criterion for operability. Magnetic resonance imaging (MRI) offers a rapid and powerful tool for the detection of lymph node metastasis (LNM) and in the current manuscript is assessed as a critical tool in the preoperative protocol for liver resection for treatment of CCA. However, the accuracy of MRI to detect LNM from CCA had yet to be comprehensively evaluated. The accuracy of MRI to detect LNM was assessed in a cohort of individuals with CCA from the Cholangiocarcinoma Screening and Care Program (CASCAP), a screening program designed to reduce CCA in Northeastern Thailand by community-based ultrasound (US) for CCA. CCA-positive individuals are referred to one of the nine tertiary centers in the study to undergo a preoperative protocol that included enhanced imaging by MRI. Additionally, these individuals also underwent lymph node biopsies for histological confirmation of LNM (the "gold standard") to determine the accuracy of the MRI results. MRI accurately detected the presence or absence of LNM in only 29 out of the 51 CCA cases (56.9%, 95% CI 42.2-70.7), resulting in a sensitivity of 57.1% (95% CI 34.0-78.2) and specificity of 56.7% (95% CI 37.4-74.5), with positive and negative predictive values of 48.0% (95% CI 27.8-68.7) and 65.4% (95% CI 44.3-82.8), respectively. The positive likelihood ratio was 1.32 (95% CI 0.76-2.29), and the negative likelihood ratio was 0.76 (95% CI 0.42-1.36). MRI showed limited sensitivity and a poor positive predictive value for the diagnosis of LNM for CCA, which is of particular concern in this resource-limited setting, where simpler detection methods could be utilized that are more cost-effective in this region of Thailand. Therefore, the inclusion of MRI, a costly imaging method, should be reconsidered as part of protocol for treatment planning of CCA, given the number of false positives, especially as it is critical in determining the operability for CCA subjects.

21-Gene recurrence score and locoregional recurrence in lymph node-negative, estrogen receptor-positive breast cancer

PubMed Central

Turashvili, Gulisa; Chou, Joanne F.; Brogi, Edi; Morrow, Monica; Dickler, Maura; Norton, Larry; Hudis, Clifford; Wen, Hannah Y

2017-01-01

Background/purpose The 21-gene recurrence score (RS) assay evaluates the likelihood of distant recurrence and benefit of chemotherapy in lymph node-negative, estrogen receptor (ER)-positive, HER2-negative breast cancer patients. The RS categories are associated with the risk of locoregional recurrence (LRR) in some, but not all studies. Methods We reviewed the institutional database to identify consecutive female patients with node-negative, ER+/HER2− breast carcinoma tested for the 21-gene RS assay and treated at our center from 2008 to 2013. We collected data on clinicopathologic features, treatment, and outcome. Statistical analysis was performed using SAS version 9.4 or R version 3.3.2. Results Of 2326 patients, 60% (1394) were in the low RS group, 33.4% (777) in the intermediate RS group, and 6.6% (155) in the high RS group. Median follow-up was 53 months. A total of 44 LRRs were observed, with a cumulative incidence of 0.17% at 12 months and 1.6% at 48 months. The cumulative incidence of LRR at 48 months was 0.84%, 2.72% and 2.80% for low, intermediate, and high RS groups, respectively (p<0.01). Univariate analysis showed that the risk of LRR was associated with the RS categories (p<0.01), T stage (p<0.01) and lymphovascular invasion (LVI) (p=0.009). There was no difference in LRR rates by initial local treatment (total mastectomy vs. breast-conserving surgery plus radiation therapy). The RS remained significantly associated with LRR after adjusting for LVI and T stage. Compared to patients with low RS, the risk of LRR was increased more than 4-fold (hazard ratio: 4.61, 95% CI 1.90–11.19, p<0.01), and 3-fold (hazard ratio: 2.81, 95% CI 1.41–5.56, p<0.01) for high and intermediate risk categories, respectively. Conclusions Our study confirms that RS is significantly associated with the risk of LRR in node-negative, ER+/HER2− breast cancer patients. Our findings suggest that in addition to its value for prognostic stage grouping and decision-making regarding adjuvant systemic therapy, the role of the RS in identifying patients not requiring radiotherapy should be studied. PMID:28702894

Significant Prognostic Factors for Completely Resected pN2 Non-small Cell Lung Cancer without Neoadjuvant Therapy

PubMed Central

Nakao, Masayuki; Mun, Mingyon; Nakagawa, Ken; Nishio, Makoto; Ishikawa, Yuichi; Okumura, Sakae

2015-01-01

Purpose: To identify prognostic factors for pathologic N2 (pN2) non-small cell lung cancer (NSCLC) treated by surgical resection. Methods: Between 1990 and 2009, 287 patients with pN2 NSCLC underwent curative resection at the Cancer Institute Hospital without preoperative treatment. Results: The 5-year overall survival (OS), cancer-specific survival (CSS), and recurrence-free survival (RFS) rates were 46%, 55% and 24%, respectively. The median follow-up time was 80 months. Multivariate analysis identified four independent predictors for poor OS: multiple-zone mediastinal lymph node metastasis (hazard ratio [HR], 1.616; p = 0.003); ipsilateral intrapulmonary metastasis (HR, 1.042; p = 0.002); tumor size >30 mm (HR, 1.013; p = 0.002); and clinical stage N1 or N2 (HR, 1.051; p = 0.030). Multivariate analysis identified three independent predictors for poor RFS: multiple-zone mediastinal lymph node metastasis (HR, 1.457; p = 0.011); ipsilateral intrapulmonary metastasis (HR, 1.040; p = 0.002); and tumor size >30 mm (HR, 1.008; p = 0.032). Conclusion: Multiple-zone mediastinal lymph node metastasis, ipsilateral intrapulmonary metastasis, and tumor size >30 mm were common independent prognostic factors of OS, CSS, and RFS in pN2 NSCLC. PMID:25740454

Outage probability of a relay strategy allowing intra-link errors utilizing Slepian-Wolf theorem

NASA Astrophysics Data System (ADS)

Cheng, Meng; Anwar, Khoirul; Matsumoto, Tad

2013-12-01

In conventional decode-and-forward (DF) one-way relay systems, a data block received at the relay node is discarded, if the information part is found to have errors after decoding. Such errors are referred to as intra-link errors in this article. However, in a setup where the relay forwards data blocks despite possible intra-link errors, the two data blocks, one from the source node and the other from the relay node, are highly correlated because they were transmitted from the same source. In this article, we focus on the outage probability analysis of such a relay transmission system, where source-destination and relay-destination links, Link 1 and Link 2, respectively, are assumed to suffer from the correlated fading variation due to block Rayleigh fading. The intra-link is assumed to be represented by a simple bit-flipping model, where some of the information bits recovered at the relay node are the flipped version of their corresponding original information bits at the source. The correlated bit streams are encoded separately by the source and relay nodes, and transmitted block-by-block to a common destination using different time slots, where the information sequence transmitted over Link 2 may be a noise-corrupted interleaved version of the original sequence. The joint decoding takes place at the destination by exploiting the correlation knowledge of the intra-link (source-relay link). It is shown that the outage probability of the proposed transmission technique can be expressed by a set of double integrals over the admissible rate range, given by the Slepian-Wolf theorem, with respect to the probability density function ( pdf) of the instantaneous signal-to-noise power ratios (SNR) of Link 1 and Link 2. It is found that, with the Slepian-Wolf relay technique, so far as the correlation ρ of the complex fading variation is | ρ|<1, the 2nd order diversity can be achieved only if the two bit streams are fully correlated. This indicates that the diversity order exhibited in the outage curve converges to 1 when the bit streams are not fully correlated. Moreover, the Slepian-Wolf outage probability is proved to be smaller than that of the 2nd order maximum ratio combining (MRC) diversity, if the average SNRs of the two independent links are the same. Exact as well as asymptotic expressions of the outage probability are theoretically derived in the article. In addition, the theoretical outage results are compared with the frame-error-rate (FER) curves, obtained by a series of simulations for the Slepian-Wolf relay system based on bit-interleaved coded modulation with iterative detection (BICM-ID). It is shown that the FER curves exhibit the same tendency as the theoretical results.

Effect of Axillary Dissection vs No Axillary Dissection on 10-Year Overall Survival Among Women With Invasive Breast Cancer and Sentinel Node Metastasis: The ACOSOG Z0011 (Alliance) Randomized Clinical Trial.

PubMed

Giuliano, Armando E; Ballman, Karla V; McCall, Linda; Beitsch, Peter D; Brennan, Meghan B; Kelemen, Pond R; Ollila, David W; Hansen, Nora M; Whitworth, Pat W; Blumencranz, Peter W; Leitch, A Marilyn; Saha, Sukamal; Hunt, Kelly K; Morrow, Monica

2017-09-12

The results of the American College of Surgeons Oncology Group Z0011 (ACOSOG Z0011) trial were first reported in 2005 with a median follow-up of 6.3 years. Longer follow-up was necessary because the majority of the patients had estrogen receptor-positive tumors that may recur later in the disease course (the ACOSOG is now part of the Alliance for Clinical Trials in Oncology). To determine whether the 10-year overall survival of patients with sentinel lymph node metastases treated with breast-conserving therapy and sentinel lymph node dissection (SLND) alone without axillary lymph node dissection (ALND) is noninferior to that of women treated with axillary dissection. The ACOSOG Z0011 phase 3 randomized clinical trial enrolled patients from May 1999 to December 2004 at 115 sites (both academic and community medical centers). The last date of follow-up was September 29, 2015, in the ACOSOG Z0011 (Alliance) trial. Eligible patients were women with clinical T1 or T2 invasive breast cancer, no palpable axillary adenopathy, and 1 or 2 sentinel lymph nodes containing metastases. All patients had planned lumpectomy, planned tangential whole-breast irradiation, and adjuvant systemic therapy. Third-field radiation was prohibited. The primary outcome was overall survival with a noninferiority hazard ratio (HR) margin of 1.3. The secondary outcome was disease-free survival. Among 891 women who were randomized (median age, 55 years), 856 (96%) completed the trial (446 in the SLND alone group and 445 in the ALND group). At a median follow-up of 9.3 years (interquartile range, 6.93-10.34 years), the 10-year overall survival was 86.3% in the SLND alone group and 83.6% in the ALND group (HR, 0.85 [1-sided 95% CI, 0-1.16]; noninferiority P = .02). The 10-year disease-free survival was 80.2% in the SLND alone group and 78.2% in the ALND group (HR, 0.85 [95% CI, 0.62-1.17]; P = .32). Between year 5 and year 10, 1 regional recurrence was seen in the SLND alone group vs none in the ALND group. Ten-year regional recurrence did not differ significantly between the 2 groups. Among women with T1 or T2 invasive primary breast cancer, no palpable axillary adenopathy, and 1 or 2 sentinel lymph nodes containing metastases, 10-year overall survival for patients treated with sentinel lymph node dissection alone was noninferior to overall survival for those treated with axillary lymph node dissection. These findings do not support routine use of axillary lymph node dissection in this patient population based on 10-year outcomes. clinicaltrials.gov Identifier: NCT00003855.

Lymphadenectomy for the management of endometrial cancer

PubMed Central

May, Katie; Bryant, Andrew; Dickinson, Heather O; Kehoe, Sean; Morrison, Jo

2014-01-01

Background Endometrial carcinoma is the most common gynaecological cancer in western Europe and North America. Lymph node metastases can be found in approximately 10% of women who clinically have cancer confined to the womb prior to surgery and removal of all pelvic and para-aortic lymph nodes (lymphadenectomy) is widely advocated. Pelvic and para-aortic lymphadenectomy is part of the FIGO staging system for endometrial cancer. This recommendation is based on non-randomised controlled trials (RCTs) data that suggested improvement in survival following pelvic and para-aortic lymphadenectomy. However, treatment of pelvic lymph nodes may not confer a direct therapeutic benefit, other than allocating women to poorer prognosis groups. Furthermore, a systematic review and meta-analysis of RCTs of routine adjuvant radiotherapy to treat possible lymph node metastases in women with early-stage endometrial cancer, did not find a survival advantage. Surgical removal of pelvic and para-aortic lymph nodes has serious potential short and long-term sequelae and most women will not have positive lymph nodes. It is therefore important to establish the clinical value of a treatment with known morbidity. Objectives To evaluate the effectiveness and safety of lymphadenectomy for the management of endometrial cancer. Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL) Issue 2, 2009. Cochrane Gynaecological Cancer Review Group Trials Register, MEDLINE (1966 to June 2009), Embase (1966 to June 2009). We also searched registers of clinical trials, abstracts of scientific meetings, reference lists of included studies and contacted experts in the field. Selection criteria RCTs and quasi-RCTs that compared lymphadenectomy with no lymphadenectomy, in adult women diagnosed with endometrial cancer. Data collection and analysis Two review authors independently abstracted data and assessed risk of bias. Hazard ratios (HRs) for overall and progression-free survival and risk ratios (RRs) comparing adverse events in women who received lymphadenectomy or no lymphadenectomy were pooled in random effects meta-analyses. Main results Two RCTs met the inclusion criteria; they randomised 1945 women, and reported HRs for survival, adjusted for prognostic factors, based on 1851 women. Meta-analysis indicated no significant difference in overall and recurrence-free survival between women who received lymphadenectomy and those who received no lymphadenectomy (pooled HR = 1.07, 95% CI: 0.81 to 1.43 and HR = 1.23, 95% CI: 0.96 to 1.58 for overall and recurrence-free survival respectively). We found no statistically significant difference in risk of direct surgical morbidity between women who received lymphadenectomy and those who received no lymphadenectomy. However, women who received lymphadenectomy had a significantly higher risk of surgically related systemic morbidity and lymphoedema/lymphocyst formation than those who had no lymphadenectomy (RR = 3.72, 95% CI: 1.04 to 13.27 and RR = 8.39, 95% CI: 4.06, 17.33 for risk of surgically related systemic morbidity and lymphoedema/lymphocyst formation respectively). Authors’ conclusions We found no evidence that lymphadenectomy decreases the risk of death or disease recurrence compared with no lymphadenectomy in women with presumed stage I disease. The evidence on serious adverse events suggests that women who receive lymphadenectomy are more likely to experience surgically related systemic morbidity or lymphoedema/lymphocyst formation. PMID:20091639

Evaluation of prognostic value and stage migration effect using positive lymph node ratio in gastric cancer.

PubMed

Komatsu, S; Ichikawa, D; Nishimura, M; Kosuga, T; Okamoto, K; Konishi, H; Shiozaki, A; Fujiwara, H; Otsuji, E

2017-01-01

To detect the best cut-off value of the positive lymph node ratio (PLNR) for stratifying the prognosis and analyzing its value with regard to stage migration effect using PLNR in gastric cancer. We retrospectively analyzed 1069 consecutive gastric cancer patients, who underwent curative gastrectomy with radical lymphadenectomy from 1997 through 2009. 1) The mean number of dissected lymph nodes was 42.6 in pStage I, 32.4 in pStage II and 37.1 in pStage III. The PLNR of 0.2 was proved to be the best cut-off value to stratify the prognosis of patients into two groups (P < 0.0001; PLNR <0.2 vs. PLNR ≥0.2), and patients were correctly classified into four groups: PLNR 0, PLNR 0-<0.2, PLNR 0.2-<0.4 and PLNR ≥0.4 by the Kaplan-Meier method. 2) Compared patients with the PLNR <0.2, those with the PLNR ≥0.2 had a significantly higher incidence of pT3 or greater, pN2 or greater, lymphatic invasion, vascular invasion and undifferentiated cancer. Multivariate analysis showed that the PLNR ≥0.2 was an independent prognostic factor [P < 0.0001, HR 2.77 (95% CI: 1.87-4.09)]. 2) The PLNR cut-off value of 0.2 could discriminate a stage migration effect in pN2-N3 and pStage II-III, which patients with PLNR ≥0.2 might be potentially diagnosed as a lower stage after gastrectomy. The PLNR contributes to evaluating prognosis and stage migration effect even in a single institute and enable to identify those who need meticulous treatments and follow-up in patients with gastric cancer. Copyright © 2016 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.

Cost-Effectiveness Analysis of Elective Neck Dissection in Patients With Clinically Node-Negative Oral Cavity Cancer.

PubMed

Acevedo, Joseph R; Fero, Katherine E; Wilson, Bayard; Sacco, Assuntina G; Mell, Loren K; Coffey, Charles S; Murphy, James D

2016-11-10

Purpose Recently, a large randomized trial found a survival advantage among patients who received elective neck dissection in conjunction with primary surgery for clinically node-negative oral cavity cancer compared with those receiving primary surgery alone. However, elective neck dissection comes with greater upfront cost and patient morbidity. We present a cost-effectiveness analysis of elective neck dissection for the initial surgical management of early-stage oral cavity cancer. Methods We constructed a Markov model to simulate primary, adjuvant, and salvage therapy; disease recurrence; and survival in patients with T1/T2 clinically node-negative oral cavity squamous cell carcinoma. Transition probabilities were derived from clinical trial data; costs (in 2015 US dollars) and health utilities were estimated from the literature. Incremental cost-effectiveness ratios, expressed as dollar per quality-adjusted life-year (QALY), were calculated with incremental cost-effectiveness ratios less than $100,000/QALY considered cost effective. We conducted one-way and probabilistic sensitivity analyses to examine model uncertainty. Results Our base-case model found that over a lifetime the addition of elective neck dissection to primary surgery reduced overall costs by $6,000 and improved effectiveness by 0.42 QALYs compared with primary surgery alone. The decrease in overall cost despite the added neck dissection was a result of less use of salvage therapy. On one-way sensitivity analysis, the model was most sensitive to assumptions about disease recurrence, survival, and the health utility reduction from a neck dissection. Probabilistic sensitivity analysis found that treatment with elective neck dissection was cost effective 76% of the time at a willingness-to-pay threshold of $100,000/QALY. Conclusion Our study found that the addition of elective neck dissection reduces costs and improves health outcomes, making this a cost-effective treatment strategy for patients with early-stage oral cavity cancer.

Coexpression of α6β4 Integrin and Guanine Nucleotide Exchange Factor Net1 Identifies Node-Positive Breast Cancer Patients at High Risk for Distant Metastasis

PubMed Central

Gilcrease, Michael Z.; Kilpatrick, Shannan K.; Woodward, Wendy A.; Zhou, Xiao; Nicolas, Marlo M.; Corley, Lynda J.; Fuller, Gregory N.; Tucker, Susan L.; Diaz, Leslie K.; Buchholz, Thomas A.; Frost, Jeffrey A.

2009-01-01

Preclinical data indicate that α6β4 integrin signaling through Ras homolog gene family, member A, plays an important role in tumor cell motility. The objective of this study was to determine whether the combined expression of α6β4 integrin and neuroepithelioma transforming gene 1 (Net1), a guanine nucleotide exchange factor specific for Ras homolog gene family member A, is associated with adverse clinical outcome in breast cancer patients. Immunohistochemical expression of each protein was evaluated in a tumor tissue microarray prepared from the primary tumors of 94 node-positive patients with invasive breast carcinoma treated with total mastectomy and doxorubicin-based chemotherapy without radiation with a median follow-up of 12.5 years. Associations between staining results and multiple clinicopathologic variables were investigated. Although there was no significant association between α6β4 integrin or Net1 expression and clinical outcome when each marker was considered individually, coexpression of α6β4 and Net1 was associated with decreased distant metastasis–free survival (P = 0.030). In the subset of patients with hormone receptor–positive tumors, coexpression of α6β4 and Net1 was associated with a decrease in distant metastasis–free and overall survival (P < 0.001 and P = 0.006, respectively). Although an association between human epidermal growth factor receptor 2 expression and coexpression of α6β4 and Net1 (P = 0.008) was observed, coexpression of α6β4 and Net1 (hazard ratio, 1.63; P = 0.02) and lymphovascular invasion (hazard ratio, 2.35; P = 0.02) were the only factors independently associated with the development of distant metastasis in multivariate analysis. These findings suggest that coexpression of α6β4 integrin and Net1 could be a useful biomarker for aggressive disease in node-positive breast cancer patients. PMID:19124484

The Prognostic Significance of Sentinel Lymph Node Status for Patients with Thick Melanoma.

PubMed

Bello, Danielle M; Han, Gang; Jackson, Laura; Bulloch, Kaleigh; Ariyan, Stephan; Narayan, Deepak; Rothberg, Bonnie Gould; Han, Dale

2016-12-01

Sentinel lymph node biopsy (SLNB) is recommended for patients with intermediate-thickness melanoma, but the use of SLNB for patients with thick melanoma is debated. This report presents a single-institution study investigating factors predictive of sentinel lymph node (SLN) metastasis and outcome for thick-melanoma patients . A retrospective review of a single-institution database from 1997 to 2012 identified 147 patients with thick primary cutaneous melanoma (≥4 mm) who had an SLNB. Clinicopathologic characteristics were correlated with nodal status and outcome. The median age of the patients was 67 years, and 61.9 % of the patients were men. The median tumor thickness was 5.5 mm, and 54 patients (36.7 %) had a positive SLN. Multivariable analysis showed that only tumor thickness significantly predicted SLN metastasis (odds ratio 1.14; 95 % confidence interval (CI) 1.02-1.28; P = 0.02). The overall median follow-up period was 34.6 months. Overall survival (OS) and melanoma-specific survival (MSS) were significantly worse for the positive versus negative-SLN patients. Multivariable analysis showed that age [hazard ratio (HR) 1.04; 95 % CI 1.01-1.07; P = 0.02] and SLN status (HR 2.24; 95 % CI 1.03-4.88; P = 0.04) significantly predicted OS, whereas only SLN status (HR 3.85; 95 % CI 2.13-6.97; P < 0.01) significantly predicted MSS. Tumor thickness predicts SLN status in thick melanomas. Furthermore, SLN status is prognostic for OS and MSS in thick-melanoma patients, with positive-SLN patients having significantly worse OS and MSS. These findings show that SLNB should be recommended for thick-melanoma patients, particularly because detection of SLN metastasis can identify patients for potential systemic therapy and treatment of nodal disease at a microscopic stage.

Plasmacytoid dendritic cells (PDC) are the major DC subset innately producing cytokines in human lymph nodes.

PubMed

Cox, Karina; North, Margaret; Burke, Michael; Singhal, Hemant; Renton, Sophie; Aqel, Nayef; Islam, Sabita; Knight, Stella C

2005-11-01

Plasmacytoid dendritic cells (PDC) constitute a distinct subset of DC found in human peripheral lymph nodes (LN), but little is known about their function. Cell suspensions were prepared from tumor draining LN (n=20) and control LN (n=11) of women undergoing surgical resection for primary breast cancer and elective surgery for benign conditions, respectively. Using four-color flow cytometry, human leukocyte antigen-DR+ DC subsets were identified phenotypically. The proportions and numbers of cells innately producing interleukin (IL)-4, IL-10, IL-12, and interferon-gamma (IFN-gamma) were also measured from intracellular accumulation of cytokine after blocking with monensin. All flow cytometry data were collected without compensation and were compensated off-line using the Winlist algorithm (Verity software). This package also provided the subtraction program to calculate percentage positive cells and intensity of staining. PDC (CD11c-, CD123+) expressed more cytokines than did myeloid DC (CD11c+) or CD1a+ putative "migratory" DC (P<0.001). LN PDC from patients with a good prognosis (px; n=11) demonstrated a relative increase in IL-12 and IFN-gamma expression (median IL-10:IL-12 ratio=0.78 and median IL-4:IFN-gamma ratio=0.7), and PDC from LN draining poor px cancer (n=9) showed a relative increase in IL-10 and IL-4 expression (median IL-10:IL-12 ratio=1.31 and median IL-4:IFN-gamma ratio=2.6). The difference in IL-4:IFN-gamma expression between good and poor px cancer groups was significant (P<0.05). Thus, PDC innately producing cytokines were identified in cell suspensions from human LN, and the character of PDC cytokine secretion may differ between two breast cancer prognostic groups. We speculate that a shift towards PDC IL-10 and IL-4 expression could promote tumor tolerance in LN draining poor px breast cancer.

Opposing flow in square porous annulus: Influence of Dufour effect

DOE Office of Scientific and Technical Information (OSTI.GOV)

Athani, Abdulgaphur, E-mail: abbu.bec@gmail.com; Al-Rashed, Abdullah A. A. A., E-mail: aa.alrashed@paaet.edu.kw; Khaleed, H. M. T., E-mail: khalid-tan@yahoo.com

Heat and mass transfer in porous medium is very important area of research which is also termed as double diffusive convection or thermo-solutal convection. The buoyancy ratio which is the ratio of thermal to concentration buoyancy can have negative values thus leading to opposing flow. This article is aimed to study the influence of Dufour effect on the opposing flow in a square porous annulus. The partial differential equations that govern the heat and mass transfer behavior inside porous medium are solved using finite element method. A three node triangular element is used to divide the porous domain into smallermore » elements. Results are presented with respect to geometric and physical parameters such as duct diameter ratio, Rayleigh number, radiation parameter etc. It is found that the heat transfer increase with increase in Rayleigh number and radiation parameter. It is observed that Dufour coefficient has more influence on velocity profile.« less

Systems and methods for optimal power flow on a radial network

DOEpatents

Low, Steven H.; Peng, Qiuyu

2018-04-24

Node controllers and power distribution networks in accordance with embodiments of the invention enable distributed power control. One embodiment includes a node controller including a distributed power control application; a plurality of node operating parameters describing the operating parameter of a node and a set of at least one node selected from the group consisting of an ancestor node and at least one child node; wherein send node operating parameters to nodes in the set of at least one node; receive operating parameters from the nodes in the set of at least one node; calculate a plurality of updated node operating parameters using an iterative process to determine the updated node operating parameters using the node operating parameters that describe the operating parameters of the node and the set of at least one node, where the iterative process involves evaluation of a closed form solution; and adjust node operating parameters.

Analytical Model of Inlet Growth and Equilibrium Cross-Sectional Area

DTIC Science & Technology

2016-04-01

performance in a real-world setting. BACKGROUND: Long-term inlet stability in bar-built systems is determined by the tidal and wave forces that...across the node was limited due to convergence of the two incoming tidal waves . As such, the equivalent bay area was calculated using the midpoint as a...sediment transport is driven by tides and does not incorporate other forcing and associated sediment pathways. The ratio of wave to tidal energy is an

Surgical Tourniquets in Orthopaedics

DTIC Science & Technology

2009-12-01

occlusion pressure and the ratio of the cuff width to the limb circumference23. This relationship is shown in Figure 4, indicating that, for a given limb...measured limb occlusion pressure to account for physiologic Fig. 3 a: A normal node of Ranvier of a nerve in a limb, showing a nodal gap 1 to 2 mm in ...limb occlusion pressure an additional pressure safety margin that is selected to be greater than the magnitude of any increase in limb occlusion

Can the new RCP R0/R1 classification predict the clinical outcome in ductal adenocarcinoma of the pancreatic head?

PubMed

Janot, M S; Kersting, S; Belyaev, O; Matuschek, A; Chromik, A M; Suelberg, D; Uhl, W; Tannapfel, A; Bergmann, U

2012-08-01

According to the International Union Against Cancer (UICC), R1 is defined as the microscopic presence of tumor cells at the surface of the resection margin (RM). In contrast, the Royal College of Pathologists (RCP) suggested to declare R1 already when tumor cells are found within 1 mm of the RM. The aim of this study was to determine the significance of the RM concerning the prognosis of pancreatic ductal adenocarcinoma (PDAC). From 2007 to 2009, 62 patients underwent a curative operation for PDAC of the pancreatic head. The relevance of R status on cumulative overall survival (OS) was assessed on univariate and multivariate analysis for both the classic R classification (UICC) and the suggestion of the RCP. Following the UICC criteria, a positive RM was detected in 8 %. Along with grading and lymph node ratio, R status revealed a significant impact on OS on univariate and multivariate analysis. Applying the suggestion of the RCP, R1 rate rose to 26 % resulting in no significant impact on OS in univariate analysis. Our study has shown that the RCP suggestion for R status has no impact on the prognosis of PDAC. In contrast, our data confirmed the UICC R classification of RM as well as N category, grading, and lymph node ratio as significant prognostic factors.

The prognostic value of circulating tumor cells in patients with melanoma: a systematic review and meta-analysis.

PubMed

Mocellin, Simone; Hoon, Dave; Ambrosi, Alessandro; Nitti, Donato; Rossi, Carlo Riccardo

2006-08-01

The detection of circulating tumor cells (CTC) in patients with melanoma represents an appealing prognostic tool, but no consensus exists on this topic. We aimed to comprehensively and quantitatively summarize the evidence for the use of CTC to predict patients' clinical outcome. Fifty-three studies enrolling 5,433 patients were reviewed. Correlation of CTC status with tumor-node-metastasis disease stage and patients' overall (OS) and progression-free (PFS) survival was assessed by means of association statistics and meta-analysis, respectively. CTC status correlated with both tumor-node-metastasis stage (stage I, 32%; stage II, 41.7%; stage III, 41.1%; stage IV, 47.4%; P(trend) < 0.0001) and survival (OS: hazard ratio, 2.42; 95% confidence interval, 1.7-3.45, P < 0.0001; PFS: hazard ratio, 2.45; 95% confidence interval, 1.78-3.38; P < 0.0001). However, statistical heterogeneity was significant for both OS and PFS, likely underscoring the wide variability in study design. Furthermore, CTC positivity rates in early stages were higher and in the metastatic setting were lower than expected, which indicates an unsatisfactory accuracy of currently available CTC detection assays. Our findings suggest that CTC might have a clinically valuable prognostic power in patients with melanoma. However, the heterogeneity of the studies thus far published warrants caution not to overestimate the favorable results of pooled data.

Improving the communication reliability of body sensor networks based on the IEEE 802.15.4 protocol.

PubMed

Gomes, Diogo; Afonso, José A

2014-03-01

Body sensor networks (BSNs) enable continuous monitoring of patients anywhere, with minimum constraints to daily life activities. Although the IEEE 802.15.4 and ZigBee(®) (ZigBee Alliance, San Ramon, CA) standards were mainly developed for use in wireless sensors network (WSN) applications, they are also widely used in BSN applications because of device characteristics such as low power, low cost, and small form factor. However, compared with WSNs, BSNs present some very distinctive characteristics in terms of traffic and mobility patterns, heterogeneity of the nodes, and quality of service requirements. This article evaluates the suitability of the carrier sense multiple access-collision avoidance protocol, used by the IEEE 802.15.4 and ZigBee standards, for data-intensive BSN applications, through the execution of experimental tests in different evaluation scenarios, in order to take into account the effects of contention, clock drift, and hidden nodes on the communication reliability. Results show that the delivery ratio may decrease substantially during transitory periods, which can last for several minutes, to a minimum of 90% with retransmissions and 13% without retransmissions. This article also proposes and evaluates the performance of the BSN contention avoidance mechanism, which was designed to solve the identified reliability problems. This mechanism was able to restore the delivery ratio to 100% even in the scenario without retransmissions.

Clinical characteristics of patients with bone sarcoidosis.

PubMed

Zhou, Ying; Lower, Elyse E; Li, Huiping; Farhey, Yolanda; Baughman, Robert P

2017-08-01

To assess the clinical features, diagnosis, and treatment of bone sarcoidosis in the United States. Patients with bone sarcoidosis were identified and matched to sarcoidosis patients based on race, gender, and age. Detailed characteristics were obtained by medical record review. A total of 64 patients with bone sarcoidosis were enrolled in this study. The female:male ratio was 1.46:1 and the white:black ratio was 3:1. Thirty-eight (59.4%) of 64 patients had bone symptoms. Compared to matched cases, bone sarcoidosis patients have more multi-organ involvement and higher incidence with liver, spleen, and extrathoracic lymph node involvement than controls (P < 0.05). Spine was the most commonly affected bone in 44 (68.8%) of patients, followed by pelvis (35.9%), and hands (15.6%). MRI and PET/CT scan was the common imaging technology, which performed in 36 patients and 32 patients, respectively, and with 97.2% and 93.8% positive bone uptake. Laboratory test indicated anemia was more common in bone sarcoidosis group than controls (P = 0.044). Infliximab was more commonly used in bone sarcoidosis patients than controls (P = 0.009). Bone sarcoidosis was associated with multi-organs affection, and high frequency of liver, spleen, or extrathoracic lymph node involvement. Infliximab should be considered in those patients with aggressive and refractory bone sarcoidosis. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Elevated CD147 expression is associated with shorter overall survival in non-small cell lung cancer.

PubMed

Zhang, Xiaojun; Tian, Tian; Zhang, Xiaofeng; Liu, Changting; Fang, Xiangqun

2017-06-06

A number of studies have reported on the prognostic role of CD147 expression in non-small cell lung cancer (NSCLC); however, the results remain controversial. This study aims to investigate the impact of CD147 on the prognosis of NSCLC by means of a meta-analysis. A literature search was performed for relevant studies published before October 29, 2016. The hazard ratios (HRs), odds ratios (ORs), and 95% confidence intervals (CIs) were calculated as effective measures. Sensitivity analysis and publication bias examination were also conducted. Ten eligible studies with a total of 1605 patients were included in this meta-analysis. CD147 overexpression was correlated with poor overall survival (OS) (HR=1.59, 95% CI=1.32-1.91, p<0.001). Elevated CD147 expression was associated with the presence of lymph node metastasis (OR=2.31, 95% CI=1.74-3.07, p<0.001) and advanced TNM stage (OR=3.03, 95% CI=1.24-7.39, p=0.015). However, no significant association between CD147 and sex, age, differentiation, or histology was found. No evidence of significant publication bias was identified. This meta-analysis revealed that overexpression of CD147 was associated with shorter OS, the presence of lymph node metastasis and advanced TNM stage in NSCLC. Therefore, CD147 could serve as a potential prognostic marker for NSCLC.

Elevated CD147 expression is associated with shorter overall survival in non-small cell lung cancer

PubMed Central

Zhang, Xiaojun; Tian, Tian; Zhang, Xiaofeng; Liu, Changting; Fang, Xiangqun

2017-01-01

A number of studies have reported on the prognostic role of CD147 expression in non-small cell lung cancer (NSCLC); however, the results remain controversial. This study aims to investigate the impact of CD147 on the prognosis of NSCLC by means of a meta-analysis. A literature search was performed for relevant studies published before October 29, 2016. The hazard ratios (HRs), odds ratios (ORs), and 95% confidence intervals (CIs) were calculated as effective measures. Sensitivity analysis and publication bias examination were also conducted. Ten eligible studies with a total of 1605 patients were included in this meta-analysis. CD147 overexpression was correlated with poor overall survival (OS) (HR=1.59, 95% CI=1.32–1.91, p<0.001). Elevated CD147 expression was associated with the presence of lymph node metastasis (OR=2.31, 95% CI=1.74–3.07, p<0.001) and advanced TNM stage (OR=3.03, 95% CI=1.24–7.39, p=0.015). However, no significant association between CD147 and sex, age, differentiation, or histology was found. No evidence of significant publication bias was identified. This meta-analysis revealed that overexpression of CD147 was associated with shorter OS, the presence of lymph node metastasis and advanced TNM stage in NSCLC. Therefore, CD147 could serve as a potential prognostic marker for NSCLC. PMID:28445149

The number of tumor infiltrating T-cell subsets in lymph nodes from patients with Hodgkin lymphoma is associated with the outcome after first line ABVD therapy.

PubMed

Alonso-Álvarez, Sara; Vidriales, Maria Belén; Caballero, Maria Dolores; Blanco, Oscar; Puig, Noemí; Martin, Alejandro; Peñarrubia, Maria Jesús; Zato, Esther; Galende, Josefina; Bárez, Abelardo; Alcoceba, Miguel; Orfão, Alberto; González, Marcos; García-Sanz, Ramón

2017-05-01

Prognostic factors in Hodgkin lymphoma (HL) still fail to accurately identify high-risk patients. Tumor microenvironment in HL is a current focus of research for risk definition but few studies have focused on infiltrating lymphocytes. Here, we analyzed the number of tumor infiltrating lymphocytes by flow cytometry in diagnostic biopsies from 96 HL homogeneously treated patients with ABVD with or without radiotherapy. Most lymph node cells were lymphocytes (90 ± 17), with a median T/B/NK distribution of 74%/26%/0.7%, and CD4 + T-cell predominance. The amount of CD19 + B cells, and NK cells did not show association with disease features. However, high numbers of CD8 + and CD4 + cells were associated with better and poorer outcomes, respectively. Patients with ≥15% cytotoxic CD8 + cells among the total cell population had a longer 10-year freedom from treatment failure (FFTF) (93% vs. 73%, p=.04). In turn, cases with ≥75% of CD4 + infiltrating cells showed a significantly decreased FFTF (73% vs. 96%, p=.021). Consequently, CD4/CD8 ratio ≥5 associated with a poorer 10-year FFTF (69.5% vs. 94%, p=.02). This deleterious effect was particularly prominent in advanced disease (n = 58, p=.01). In multivariate analysis, a CD4/CD8 ratio ≥5 was the only independent variable to predict for treatment failure (HR = 4.5, 95% confidence interval, 1.2-16.8). In conclusion, our study shows that high CD4 + and low CD8 + T-cells infiltrates of tumor specimens associate with poor prognosis in HL patients, and CD4/CD8 ratio might be potentially useful for tailoring therapy.

Transcatheter Arterial Embolization With Spherical Embolic Agent for Pulmonary Metastases From Renal Cell Carcinoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seki, Akihiko, E-mail: sekia@igtc.jp; Hori, Shinichi, E-mail: horishin@igtc.jp; Sueyoshi, Satoru, E-mail: sueyoshis@igtc.jp

2013-12-15

Purpose: This retrospective study aimed to evaluate the safety and local efficacy of transcatheter arterial embolization (TAE) with superabsorbent polymer microspheres (SAP-MS) in patients with pulmonary metastases from renal cell carcinoma (RCC). Methods: Sixteen patients with unresectable pulmonary metastases from RCC refractory to standard therapy were enrolled to undergo TAE with the purpose of mass reduction and/or palliation. The prepared SAP-MS swell to approximately two times larger than their dry-state size (100-150 {mu}m [n = 14], 50-100 {mu}m [n = 2]). Forty-nine pulmonary nodules (lung n = 22, mediastinal lymph node n = 17, and hilar lymph node n =more » 10) were selected as target lesions for evaluation. Local tumor response was evaluated 3 months after TAE according to Response Evaluation Criteria in Solid Tumors (RECIST; version 1.1). The relationship between tumor enhancement ratio by CT during selective angiography and local tumor response was evaluated. Results: The number of TAE sessions per patient ranged from 1 to 5 (median 2.9). Embolized arteries at initial TAE were bronchial arteries in 14 patients (87.5 %) and nonbronchial systemic arteries in 11 patients (68.8 %). Nodule-based evaluation showed that 5 (10.2 %) nodules had complete response, 17 (34.7 %) had partial response, 15 (30.6 %) had stable disease, and 12 (24.5 %) had progressive disease. The response rate was significantly greater in 22 lesions that had a high tumor enhancement ratio than in 27 lesions that had a slight or moderate ratio (90.9 vs. 7.4 %, p = 0.01). Severe TAE-related adverse events did not occur. Conclusion: TAE with SAP-MS might be a well-tolerated and locally efficacious palliative option for patients with pulmonary metastases from RCC.« less

Parametric binary dissection

NASA Technical Reports Server (NTRS)

Bokhari, Shahid H.; Crockett, Thomas W.; Nicol, David M.

1993-01-01

Binary dissection is widely used to partition non-uniform domains over parallel computers. This algorithm does not consider the perimeter, surface area, or aspect ratio of the regions being generated and can yield decompositions that have poor communication to computation ratio. Parametric Binary Dissection (PBD) is a new algorithm in which each cut is chosen to minimize load + lambda x(shape). In a 2 (or 3) dimensional problem, load is the amount of computation to be performed in a subregion and shape could refer to the perimeter (respectively surface) of that subregion. Shape is a measure of communication overhead and the parameter permits us to trade off load imbalance against communication overhead. When A is zero, the algorithm reduces to plain binary dissection. This algorithm can be used to partition graphs embedded in 2 or 3-d. Load is the number of nodes in a subregion, shape the number of edges that leave that subregion, and lambda the ratio of time to communicate over an edge to the time to compute at a node. An algorithm is presented that finds the depth d parametric dissection of an embedded graph with n vertices and e edges in O(max(n log n, de)) time, which is an improvement over the O(dn log n) time of plain binary dissection. Parallel versions of this algorithm are also presented; the best of these requires O((n/p) log(sup 3)p) time on a p processor hypercube, assuming graphs of bounded degree. How PBD is applied to 3-d unstructured meshes and yields partitions that are better than those obtained by plain dissection is described. Its application to the color image quantization problem is also discussed, in which samples in a high-resolution color space are mapped onto a lower resolution space in a way that minimizes the color error.

Self-organized topology of recurrence-based complex networks

NASA Astrophysics Data System (ADS)

Yang, Hui; Liu, Gang

2013-12-01

With the rapid technological advancement, network is almost everywhere in our daily life. Network theory leads to a new way to investigate the dynamics of complex systems. As a result, many methods are proposed to construct a network from nonlinear time series, including the partition of state space, visibility graph, nearest neighbors, and recurrence approaches. However, most previous works focus on deriving the adjacency matrix to represent the complex network and extract new network-theoretic measures. Although the adjacency matrix provides connectivity information of nodes and edges, the network geometry can take variable forms. The research objective of this article is to develop a self-organizing approach to derive the steady geometric structure of a network from the adjacency matrix. We simulate the recurrence network as a physical system by treating the edges as springs and the nodes as electrically charged particles. Then, force-directed algorithms are developed to automatically organize the network geometry by minimizing the system energy. Further, a set of experiments were designed to investigate important factors (i.e., dynamical systems, network construction methods, force-model parameter, nonhomogeneous distribution) affecting this self-organizing process. Interestingly, experimental results show that the self-organized geometry recovers the attractor of a dynamical system that produced the adjacency matrix. This research addresses a question, i.e., "what is the self-organizing geometry of a recurrence network?" and provides a new way to reproduce the attractor or time series from the recurrence plot. As a result, novel network-theoretic measures (e.g., average path length and proximity ratio) can be achieved based on actual node-to-node distances in the self-organized network topology. The paper brings the physical models into the recurrence analysis and discloses the spatial geometry of recurrence networks.

Right- and left-sided colon cancer – clinical and pathological differences of the disease entity in one organ

PubMed Central

Berut, Maciej; Dziki, Lukasz; Trzcinski, Radzislaw; Dziki, Adam

2016-01-01

Introduction Some researchers suggest that cancers located in the right vs. the left side of the colon are different and they can be regarded as distinct disease entities. The aim of this study was to analyze differences in clinical, epidemiological and pathological features of patients with right-sided (RCC) and left-sided (LCC) colon cancer. Material and methods One thousand two hundred and twenty-four patients were operated on due to colorectal cancer. A group of 477 patients (254 women, mean age 65.5 ±11 for the whole group) with colon cancer was included (212 RCC vs. 265 LCC). Results Right colon cancer patients were older (67.8 ±11.3 vs. 63.2 ±11.2; p = 0.0087). Left colon cancer patients underwent surgery for urgent indications more often (17.0% vs. 8.5%; p = 0006). Tumor diameter was greater in the RCC group (55 ±60 mm vs. 38 ±21 mm; p = 0.0003). Total number of removed lymph nodes was higher in the RCC group (11.7 ±6 vs. 8.3 ±5; p = 0.0001). Lymph node ratio was higher in the LCC group (0.45 ±0.28 vs. 0.30 ±0.25; p = 0.0063). We found a strong positive correlation between tumor diameter and the number of removed lymph nodes in the LCC group (r = 0.531). Conclusions These differences may result from the fact that RCC patients are diagnosed at an older age. The smaller number of removed lymph nodes in LCC patients may result in incorrect staging. It is still necessary to find other biological dissimilarities of adenocarcinoma located on different sides of the colon. PMID:28144267

Right- and left-sided colon cancer - clinical and pathological differences of the disease entity in one organ.

PubMed

Mik, Michal; Berut, Maciej; Dziki, Lukasz; Trzcinski, Radzislaw; Dziki, Adam

2017-02-01

Some researchers suggest that cancers located in the right vs. the left side of the colon are different and they can be regarded as distinct disease entities. The aim of this study was to analyze differences in clinical, epidemiological and pathological features of patients with right-sided (RCC) and left-sided (LCC) colon cancer. One thousand two hundred and twenty-four patients were operated on due to colorectal cancer. A group of 477 patients (254 women, mean age 65.5 ±11 for the whole group) with colon cancer was included (212 RCC vs. 265 LCC). Right colon cancer patients were older (67.8 ±11.3 vs. 63.2 ±11.2; p = 0.0087). Left colon cancer patients underwent surgery for urgent indications more often (17.0% vs. 8.5%; p = 0006). Tumor diameter was greater in the RCC group (55 ±60 mm vs. 38 ±21 mm; p = 0.0003). Total number of removed lymph nodes was higher in the RCC group (11.7 ±6 vs. 8.3 ±5; p = 0.0001). Lymph node ratio was higher in the LCC group (0.45 ±0.28 vs. 0.30 ±0.25; p = 0.0063). We found a strong positive correlation between tumor diameter and the number of removed lymph nodes in the LCC group ( r = 0.531). These differences may result from the fact that RCC patients are diagnosed at an older age. The smaller number of removed lymph nodes in LCC patients may result in incorrect staging. It is still necessary to find other biological dissimilarities of adenocarcinoma located on different sides of the colon.

Histological assessment of cervical lymph node identifies patients with head and neck squamous cell carcinoma (HNSCC): who would benefit from chemoradiation after surgery?

PubMed

Wan, Xiao Chloe; Egloff, Ann Marie; Johnson, Jonas

2012-12-01

Postoperative chemoradiation (CRT) has been shown to be more effective than postoperative radiotherapy (RT) alone in high risk head and neck squamous cell carcinoma (HNSCC) patients. Multimodality therapy is associated with more treatment related-toxicity. In this study, we assessed cervical lymph node histological characteristics to detect prognostic and predictive value differences to help guide therapeutic decision making. Retrospective analysis of Cancer Registry data. HNSCC surgical patients who had tumor resection and neck dissection at our institution from 1980 to 2008 were identified (n=1510). Multivariable Cox proportional hazards regression models were developed to identify significant predictors of three outcomes: overall survival (OS), disease-specific survival (DSS), and neck disease recurrence (NDR). Hazard ratios were estimated for the number of cervical nodal metastases and presence of extracapsular spread (ECS) by adjuvant treatment after controlling for significant covariates. Increasing number of positive nodes was significantly associated with poorer outcomes in OS, DSS, and NDR models (p<0.0001, p<0.0001, p=0.0002, respectively). OS and DSS associated with adjuvant treatment (none, RT, or CRT) were modified by number of positive nodes, ECS status, and cancer site. The presence of ECS was associated with reduced OS and DSS (p=0.077, p=0.001 respectively), but not significantly associated with NDR (p=0.179). Nodal positive patients benefited from adjuvant therapy regardless of ECS status. CRT consistently conferred a survival advantage over RT across all nodal categories, although the difference was not statistically significant. We observed a consistent survival advantage with CRT over RT for patients with positive cervical nodal metastasis, although the difference was not statistically significant. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

Poor Prognosis of Lower Inner Quadrant in Lymph Node-negative Breast Cancer Patients Who Received No Chemotherapy: A Study Based on Nationwide Korean Breast Cancer Registry Database.

PubMed

Hwang, Ki-Tae; Kim, Jongjin; Kim, Eun-Kyu; Jung, Sung Hoo; Sohn, Guiyun; Kim, Seung Il; Jeong, Joon; Lee, Hyouk Jin; Park, Jin Hyun; Oh, Sohee

2017-07-01

We aimed to investigate the prognostic influence of primary tumor site on the survival of patients with breast cancer. Data of 63,388 patients with primary breast cancer from the Korean Breast Cancer Registry were analyzed. Primary tumor sites were classified into 5 groups: upper outer quadrant, lower outer quadrant, upper inner quadrant, lower inner quadrant (LIQ), and central portion. We analyzed overall survival (OS) and breast cancer-specific survival (BCSS) according to primary tumor site. Central portion and LIQ showed lower survival rates regarding both OS and BCSS compared with the other 3 quadrants (all P < .05) and hazard ratios were 1.267 (95% CI, 1.180-1.360, P < .001) and 1.215 (95% CI, 1.097-1.345, P < .001), respectively. Although central portion showed more unfavorable clinicopathologic features, LIQ showed more favorable features than the other 3 quadrants. Primary tumor site was a significant factor in univariate and multivariate analyses for OS and BCSS (all P < .001). For lymph node-negative patients, LIQ showed a worse OS than the other primary tumor sites in the subgroup with no chemotherapy (P < .001), but that effect disappeared in the subgroup with chemotherapy (P = .058). LIQ showed a worse prognosis despite having more favorable clinicopathologic features than other tumor locations and it was more prominent for lymph node-negative patients who received no chemotherapy. The hypothesis of possible hidden internal mammary node metastasis could be suggested to play a key role in LIQ lesions. Copyright © 2017 Elsevier Inc. All rights reserved.

Self-organized topology of recurrence-based complex networks.

PubMed

Yang, Hui; Liu, Gang

2013-12-01

With the rapid technological advancement, network is almost everywhere in our daily life. Network theory leads to a new way to investigate the dynamics of complex systems. As a result, many methods are proposed to construct a network from nonlinear time series, including the partition of state space, visibility graph, nearest neighbors, and recurrence approaches. However, most previous works focus on deriving the adjacency matrix to represent the complex network and extract new network-theoretic measures. Although the adjacency matrix provides connectivity information of nodes and edges, the network geometry can take variable forms. The research objective of this article is to develop a self-organizing approach to derive the steady geometric structure of a network from the adjacency matrix. We simulate the recurrence network as a physical system by treating the edges as springs and the nodes as electrically charged particles. Then, force-directed algorithms are developed to automatically organize the network geometry by minimizing the system energy. Further, a set of experiments were designed to investigate important factors (i.e., dynamical systems, network construction methods, force-model parameter, nonhomogeneous distribution) affecting this self-organizing process. Interestingly, experimental results show that the self-organized geometry recovers the attractor of a dynamical system that produced the adjacency matrix. This research addresses a question, i.e., "what is the self-organizing geometry of a recurrence network?" and provides a new way to reproduce the attractor or time series from the recurrence plot. As a result, novel network-theoretic measures (e.g., average path length and proximity ratio) can be achieved based on actual node-to-node distances in the self-organized network topology. The paper brings the physical models into the recurrence analysis and discloses the spatial geometry of recurrence networks.

Self-organized topology of recurrence-based complex networks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Hui, E-mail: huiyang@usf.edu; Liu, Gang

With the rapid technological advancement, network is almost everywhere in our daily life. Network theory leads to a new way to investigate the dynamics of complex systems. As a result, many methods are proposed to construct a network from nonlinear time series, including the partition of state space, visibility graph, nearest neighbors, and recurrence approaches. However, most previous works focus on deriving the adjacency matrix to represent the complex network and extract new network-theoretic measures. Although the adjacency matrix provides connectivity information of nodes and edges, the network geometry can take variable forms. The research objective of this article ismore » to develop a self-organizing approach to derive the steady geometric structure of a network from the adjacency matrix. We simulate the recurrence network as a physical system by treating the edges as springs and the nodes as electrically charged particles. Then, force-directed algorithms are developed to automatically organize the network geometry by minimizing the system energy. Further, a set of experiments were designed to investigate important factors (i.e., dynamical systems, network construction methods, force-model parameter, nonhomogeneous distribution) affecting this self-organizing process. Interestingly, experimental results show that the self-organized geometry recovers the attractor of a dynamical system that produced the adjacency matrix. This research addresses a question, i.e., “what is the self-organizing geometry of a recurrence network?” and provides a new way to reproduce the attractor or time series from the recurrence plot. As a result, novel network-theoretic measures (e.g., average path length and proximity ratio) can be achieved based on actual node-to-node distances in the self-organized network topology. The paper brings the physical models into the recurrence analysis and discloses the spatial geometry of recurrence networks.« less

Complications of pacemaker therapy in adults with congenital heart disease: a multicenter study.

PubMed

Opić, Petra; van Kranenburg, Matthijs; Yap, Sing-Chien; van Dijk, Arie P; Budts, Werner; Vliegen, Hubert W; van Erven, Lieselot; Can, Anil; Sahin, Gulhan; Theuns, Dominic A M J; Witsenburg, Maarten; Roos-Hesselink, Jolien W

2013-10-09

This study aims to investigate indications and complications of permanent cardiac pacing in adults with congenital heart disease (CHD). Two-hundred and seventy-four CHD patients were identified who underwent permanent pacemaker implantation between 1972 and 2009. The indication for pacing was acquired sinus node or AV node conduction disease (63%), sinus node or AV node conduction disease after cardiac surgery (28%), and drug/arrhythmia-related indications (9%). Patients with complex CHD received a pacemaker at younger age (23 versus 31 years, p<0.0001) and more often received an epicardial pacing system (51% versus 23%, p<0.0001) compared to those with simple or moderate CHD. Twenty-nine patients (10.6%) had a periprocedural complication during the primary pacemaker implantation (general population: 5.2%). The most common acute complications were lead dysfunction (4.0%), bleeding (2.6%), pocket infection (1.5%) and pneumothorax (1.5%). During a median follow-up of 12 years, pacemaker-related complications requiring intervention occurred in 95 patients (34.6%). The most common late pacemaker-related complications included lead failure (24.8%), pacemaker dysfunction/early battery depletion (5.1%), pacemaker migration (4.7%) and erosion (4.7%). Pacemaker implantation at younger age (<18 years) was an independent predictor of late pacemaker-related complication (adjusted hazard ratio 1.68, 95% confidence interval 1.07 to 2.63, p=0.023). The risk of periprocedural complications seems higher in the CHD population compared to the general population and more than one-third of CHD patients encountered a pacemaker-related complication during long-term follow-up. This risk increases for those who receive a pacemaker at younger age. Crown Copyright © 2013. Published by Elsevier Ireland Ltd. All rights reserved.

Pathologic Predictors of Survival During Lymph Node Dissection for Metastatic Renal-Cell Carcinoma: Results From a Multicenter Collaboration.

PubMed

Chipollini, Juan; Abel, E Jason; Peyton, Charles C; Boulware, David C; Karam, Jose A; Margulis, Vitaly; Master, Viraj A; Zargar-Shoshtari, Kamran; Matin, Surena F; Sexton, Wade J; Raman, Jay D; Wood, Christopher G; Spiess, Philippe E

2018-04-01

To determine the therapeutic value of lymph node dissection (LND) during cytoreductive nephrectomy (CN) and assess predictors of cancer-specific survival (CSS) in metastatic renal-cell carcinoma. We identified 293 consecutive patients treated with CN at 4 academic institutions from March 2000 to May 2015. LND was performed in 187 patients (63.8%). CSS was estimated by the Kaplan-Meier method for the entire cohort and for a propensity score-matched cohort. Cox proportional hazards regression was used to evaluate CSS in a multivariate model and in an inverse probability weighting-adjusted model for patients who underwent dissection. Median follow-up was 12.6 months (interquartile range, 4.47, 30.3), and median survival was 15.9 months. Of the 293 patients, 187 (63.8%) underwent LND. One hundred six patients had nodal involvement (pN+) with a median CSS of 11.3 months (95% confidence interval [CI], 6.6, 15.9) versus 24.2 months (95% confidence interval, 14.1, 34.3) for pN- patients (log-rank P = .002). The hazard ratio for LND was 1.325 (95% CI, 1.002, 1.75) for the whole cohort and 1.024 (95% CI, 0.682, 1.537) in the propensity score-matched cohort. Multivariate analysis revealed that number of positive lymph nodes (P < .001) was a significant predictor of worse CSS. For patients with metastatic renal-cell carcinoma undergoing CN with lymphadenectomy, the number of nodes positive was predictive of survival at short-term follow-up. However, nonstandardized lymphadenectomy only provided prognostic information without therapeutic benefit. Prospective studies with standardized templates are required to further ascertain the therapeutic value of LND. Copyright © 2017 Elsevier Inc. All rights reserved.

Understanding the Scalability of Bayesian Network Inference Using Clique Tree Growth Curves

NASA Technical Reports Server (NTRS)

Mengshoel, Ole J.

2010-01-01

One of the main approaches to performing computation in Bayesian networks (BNs) is clique tree clustering and propagation. The clique tree approach consists of propagation in a clique tree compiled from a Bayesian network, and while it was introduced in the 1980s, there is still a lack of understanding of how clique tree computation time depends on variations in BN size and structure. In this article, we improve this understanding by developing an approach to characterizing clique tree growth as a function of parameters that can be computed in polynomial time from BNs, specifically: (i) the ratio of the number of a BN s non-root nodes to the number of root nodes, and (ii) the expected number of moral edges in their moral graphs. Analytically, we partition the set of cliques in a clique tree into different sets, and introduce a growth curve for the total size of each set. For the special case of bipartite BNs, there are two sets and two growth curves, a mixed clique growth curve and a root clique growth curve. In experiments, where random bipartite BNs generated using the BPART algorithm are studied, we systematically increase the out-degree of the root nodes in bipartite Bayesian networks, by increasing the number of leaf nodes. Surprisingly, root clique growth is well-approximated by Gompertz growth curves, an S-shaped family of curves that has previously been used to describe growth processes in biology, medicine, and neuroscience. We believe that this research improves the understanding of the scaling behavior of clique tree clustering for a certain class of Bayesian networks; presents an aid for trade-off studies of clique tree clustering using growth curves; and ultimately provides a foundation for benchmarking and developing improved BN inference and machine learning algorithms.

The triglyceride-glucose index, an insulin resistance marker in newborns?

PubMed

Gesteiro, Eva; Bastida, Sara; Barrios, Laura; Sánchez-Muniz, Francisco J

2018-04-01

The study aims to assess the utility of the triglyceride-glucose index (TyG) as a marker of insulin resistance (IR) in neonates. TyG and the homeostatic model assessment (HOMA-IR) values were compared in 196 singleton, term normoweight and without distress newborns. A Decision Tree procedure (CHAID) was used to classify cases into groups or predict values of a dependent (Ln HOMA-IR) variable. Three nodes were drawn for TyG: ≤ 6.7, > 6.7-7.8 and > 7.8 (p < 0.0001; F = 20.52). The predictability of those TyG values vs HOMA-IR was statistically significant (p < 0.0001). It was neither affected by gender (p = 0.084), glucose challenge test (p = 0.138) classifications nor by the TyG node* glucose challenge test and TyG node*gender interactions (p = 0.456 and p = 0.209, respectively). Glucose, HOMA-IR, and the triglyceride/HDL cholesterol ratio increased progressively from node 1 to 3 for TyG while QUICKI decreased. In conclusion, TyG appears to be a suitable tool for identifying IR at birth, justifying the further insulin determination in those neonates. TyG ≥ 7.8 is recommended as cut-off point in neonates. The need for a follow-up study to confirm the TyG as early IR marker is desirable. • HOMA-IR and the triglyceride-glucose index (TyG) show a high correlation. • The TyG has been used as an insulin resistance marker in adults. • This is the first study where TyG has been assessed in neonates. • TyG appears to be a suitable and cheap tool for identifying insulin resistance at birth.

Effect of acoustic resonance phenomenon on fluid flow with light dust

NASA Astrophysics Data System (ADS)

Hamakawa, Hiromitsu; Arshad, Azim B. M.; Ohta, Mitsuo

2011-10-01

In the present paper, the attention is focused on the characteristics of lightweight materials collection in the duct using acoustic resonance phenomena. The acoustic resonance was excited by using a controlled speaker at the middle of a test duct. We measured the sound pressure level, frequency response characteristics, acoustic damping ratio, mode shape, and lightweight materials response to acoustic resonance excited by a speaker. As a result, the acoustic damping ratio decreased as the mode number of acoustic resonance increased. The tissue strips and the lightweight materials were collected at the node of acoustic pressure when the acoustic resonance was excited. It was made clear that it is possible to control lightweight materials using acoustic resonance excited by a speaker.

Sentinel nodes identified by computed tomography-lymphography accurately stage the axilla in patients with breast cancer

PubMed Central

2013-01-01

Background Sentinel node biopsy often results in the identification and removal of multiple nodes as sentinel nodes, although most of these nodes could be non-sentinel nodes. This study investigated whether computed tomography-lymphography (CT-LG) can distinguish sentinel nodes from non-sentinel nodes and whether sentinel nodes identified by CT-LG can accurately stage the axilla in patients with breast cancer. Methods This study included 184 patients with breast cancer and clinically negative nodes. Contrast agent was injected interstitially. The location of sentinel nodes was marked on the skin surface using a CT laser light navigator system. Lymph nodes located just under the marks were first removed as sentinel nodes. Then, all dyed nodes or all hot nodes were removed. Results The mean number of sentinel nodes identified by CT-LG was significantly lower than that of dyed and/or hot nodes removed (1.1 vs 1.8, p <0.0001). Twenty-three (12.5%) patients had ≥2 sentinel nodes identified by CT-LG removed, whereas 94 (51.1%) of patients had ≥2 dyed and/or hot nodes removed (p <0.0001). Pathological evaluation demonstrated that 47 (25.5%) of 184 patients had metastasis to at least one node. All 47 patients demonstrated metastases to at least one of the sentinel nodes identified by CT-LG. Conclusions CT-LG can distinguish sentinel nodes from non-sentinel nodes, and sentinel nodes identified by CT-LG can accurately stage the axilla in patients with breast cancer. Successful identification of sentinel nodes using CT-LG may facilitate image-based diagnosis of metastasis, possibly leading to the omission of sentinel node biopsy. PMID:24321242

Broadcasting a message in a parallel computer

DOEpatents

Archer, Charles J; Faraj, Ahmad A

2013-04-16

Methods, systems, and products are disclosed for broadcasting a message in a parallel computer that includes: transmitting, by the logical root to all of the nodes directly connected to the logical root, a message; and for each node except the logical root: receiving the message; if that node is the physical root, then transmitting the message to all of the child nodes except the child node from which the message was received; if that node received the message from a parent node and if that node is not a leaf node, then transmitting the message to all of the child nodes; and if that node received the message from a child node and if that node is not the physical root, then transmitting the message to all of the child nodes except the child node from which the message was received and transmitting the message to the parent node.

Broadcasting a message in a parallel computer

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

Methods, systems, and products are disclosed for broadcasting a message in a parallel computer that includes: transmitting, by the logical root to all of the nodes directly connected to the logical root, a message; and for each node except the logical root: receiving the message; if that node is the physical root, then transmitting the message to all of the child nodes except the child node from which the message was received; if that node received the message from a parent node and if that node is not a leaf node, then transmitting the message to all of the childmore » nodes; and if that node received the message from a child node and if that node is not the physical root, then transmitting the message to all of the child nodes except the child node from which the message was received and transmitting the message to the parent node.« less

A novel method for the accurate evaluation of Poisson's ratio of soft polymer materials.

PubMed

Lee, Jae-Hoon; Lee, Sang-Soo; Chang, Jun-Dong; Thompson, Mark S; Kang, Dong-Joong; Park, Sungchan; Park, Seonghun

2013-01-01

A new method with a simple algorithm was developed to accurately measure Poisson's ratio of soft materials such as polyvinyl alcohol hydrogel (PVA-H) with a custom experimental apparatus consisting of a tension device, a micro X-Y stage, an optical microscope, and a charge-coupled device camera. In the proposed method, the initial positions of the four vertices of an arbitrarily selected quadrilateral from the sample surface were first measured to generate a 2D 1st-order 4-node quadrilateral element for finite element numerical analysis. Next, minimum and maximum principal strains were calculated from differences between the initial and deformed shapes of the quadrilateral under tension. Finally, Poisson's ratio of PVA-H was determined by the ratio of minimum principal strain to maximum principal strain. This novel method has an advantage in the accurate evaluation of Poisson's ratio despite misalignment between specimens and experimental devices. In this study, Poisson's ratio of PVA-H was 0.44 ± 0.025 (n = 6) for 2.6-47.0% elongations with a tendency to decrease with increasing elongation. The current evaluation method of Poisson's ratio with a simple measurement system can be employed to a real-time automated vision-tracking system which is used to accurately evaluate the material properties of various soft materials.

Dynamically reassigning a connected node to a block of compute nodes for re-launching a failed job

DOE Office of Scientific and Technical Information (OSTI.GOV)

Budnik, Thomas A; Knudson, Brant L; Megerian, Mark G

Methods, systems, and products for dynamically reassigning a connected node to a block of compute nodes for re-launching a failed job that include: identifying that a job failed to execute on the block of compute nodes because connectivity failed between a compute node assigned as at least one of the connected nodes for the block of compute nodes and its supporting I/O node; and re-launching the job, including selecting an alternative connected node that is actively coupled for data communications with an active I/O node; and assigning the alternative connected node as the connected node for the block of computemore » nodes running the re-launched job.« less