Sample records for vaaks jri olt

  1. Isotopic fingerprint of the middle Olt River basin, Romania.

    PubMed

    Popescu, Raluca; Costinel, Diana; Ionete, Roxana Elena; Axente, Damian

    2014-01-01

    One of the most important tributaries of the Danube River in Romania, the Olt River, was characterized in its middle catchment in terms of the isotopic composition using continuous flow-isotope ratio mass spectrometry (CF-IRMS). Throughout a period of 10 months, from November 2010 to August 2011, water samples from the Olt River and its more important tributaries were collected in order to investigate the seasonal and spatial isotope patterns of the basin waters. The results revealed a significant difference between the Olt River and its tributaries, by the fact that the Olt River waters show smaller seasonal variations in the stable isotopic composition and are more depleted in (18)O and (2)H. The waters present an overall enrichment in heavy isotopes during the warm seasons.

  2. Software defined multi-OLT passive optical network for flexible traffic allocation

    NASA Astrophysics Data System (ADS)

    Zhang, Shizong; Gu, Rentao; Ji, Yuefeng; Zhang, Jiawei; Li, Hui

    2016-10-01

    With the rapid growth of 4G mobile network and vehicular network services mobile terminal users have increasing demand on data sharing among different radio remote units (RRUs) and roadside units (RSUs). Meanwhile, commercial video-streaming, video/voice conference applications delivered through peer-to-peer (P2P) technology are still keep on stimulating the sharp increment of bandwidth demand in both business and residential subscribers. However, a significant issue is that, although wavelength division multiplexing (WDM) and orthogonal frequency division multiplexing (OFDM) technology have been proposed to fulfil the ever-increasing bandwidth demand in access network, the bandwidth of optical fiber is not unlimited due to the restriction of optical component properties and modulation/demodulation technology, and blindly increase the wavelength cannot meet the cost-sensitive characteristic of the access network. In this paper, we propose a software defined multi-OLT PON architecture to support efficient scheduling of access network traffic. By introducing software defined networking technology and wavelength selective switch into TWDM PON system in central office, multiple OLTs can be considered as a bandwidth resource pool and support flexible traffic allocation for optical network units (ONUs). Moreover, under the configuration of the control plane, ONUs have the capability of changing affiliation between different OLTs under different traffic situations, thus the inter-OLT traffic can be localized and the data exchange pressure of the core network can be released. Considering this architecture is designed to be maximum following the TWDM PON specification, the existing optical distribution network (ODN) investment can be saved and conventional EPON/GPON equipment can be compatible with the proposed architecture. What's more, based on this architecture, we propose a dynamic wavelength scheduling algorithm, which can be deployed as an application on control plane

  3. Predictors of renal recovery in patients with pre-orthotopic liver transplant (OLT) renal dysfunction.

    PubMed

    Iglesias, Jose; Frank, Elliot; Mehandru, Sushil; Davis, John M; Levine, Jerrold S

    2013-07-13

    Renal dysfunction occurs commonly in patients awaiting orthotopic liver transplantation (OLT) for end-stage liver disease. The use of simultaneous liver-kidney transplantation has increased in the MELD scoring era. As patients may recover renal function after OLT, identifying factors predictive of renal recovery is a critical issue, especially given the scarcity of available organs. Employing the UNOS database, we sought to identify donor- and patient-related predictors of renal recovery among 1720 patients with pre-OLT renal dysfunction and transplanted from 1989 to 2005. Recovery of renal function post-OLT was defined as a composite endpoint of serum creatinine (SCr) ≤1.5 mg/dL at discharge and survival ≥29 days. Pre-OLT renal dysfunction was defined as any of the following: SCr ≥2 mg/dL at any time while awaiting OLT or need for renal replacement therapy (RRT) at the time of registration and/or OLT. Independent predictors of recovery of renal function post-OLT were absence of hepatic allograft dysfunction, transplantation during MELD era, recipient female sex, decreased donor age, decreased recipient ALT at time of OLT, decreased recipient body mass index at registration, use of anti-thymocyte globulin as induction therapy, and longer wait time from registration. Contrary to popular belief, a requirement for RRT, even for prolonged periods in excess of 8 weeks, was not an independent predictor of failure to recover renal function post-OLT. These data indicate that the duration of renal dysfunction, even among those requiring RRT, is a poor way to discriminate reversible from irreversible renal dysfunction.

  4. Predictors of renal recovery in patients with pre-orthotopic liver transplant (OLT) renal dysfunction

    PubMed Central

    2013-01-01

    Background Renal dysfunction occurs commonly in patients awaiting orthotopic liver transplantation (OLT) for end-stage liver disease. The use of simultaneous liver-kidney transplantation has increased in the MELD scoring era. As patients may recover renal function after OLT, identifying factors predictive of renal recovery is a critical issue, especially given the scarcity of available organs. Methods Employing the UNOS database, we sought to identify donor- and patient-related predictors of renal recovery among 1720 patients with pre-OLT renal dysfunction and transplanted from 1989 to 2005. Recovery of renal function post-OLT was defined as a composite endpoint of serum creatinine (SCr) ≤1.5 mg/dL at discharge and survival ≥29 days. Pre-OLT renal dysfunction was defined as any of the following: SCr ≥2 mg/dL at any time while awaiting OLT or need for renal replacement therapy (RRT) at the time of registration and/or OLT. Results Independent predictors of recovery of renal function post-OLT were absence of hepatic allograft dysfunction, transplantation during MELD era, recipient female sex, decreased donor age, decreased recipient ALT at time of OLT, decreased recipient body mass index at registration, use of anti-thymocyte globulin as induction therapy, and longer wait time from registration. Contrary to popular belief, a requirement for RRT, even for prolonged periods in excess of 8 weeks, was not an independent predictor of failure to recover renal function post-OLT. Conclusion These data indicate that the duration of renal dysfunction, even among those requiring RRT, is a poor way to discriminate reversible from irreversible renal dysfunction. PMID:23849513

  5. Distinct enzyme profiles in patients with cryptogenic cirrhosis reflect heterogeneous causes with different outcomes after liver transplantation (OLT): a long-term documentation before and after OLT.

    PubMed

    Berg, Thomas; Neuhaus, Ruth; Klein, Reinhild; Leder, Korinna; Lobeck, Hartmut; Bechstein, Wolf-Otto; Müller, Andrea R; Wiedenmann, Bertram; Hopf, Uwe; Berg, Peter A; Neuhaus, Peter

    2002-09-27

    Sound information is lacking about the clinical presentation of cryptogenic cirrhosis and its outcome after orthotopic liver transplantation (OLT). Among 856 patients who have been transplanted at our center, 40 patients had no evidence of any known etiologies and were therefore defined as suffering from cryptogenic cirrhosis. Their median follow-up period before OLT was 78 months (range, 1-264), and after OLT 97 months (range, 1-132). Laboratory and histological data were evaluated according to features being compatible either with a toxic, hepatitic, or cholestatic condition. The clinical and histological findings differed specifically between these three groups. The toxic-like group (GGT 4-18 x upper limit of normal [ULN]) expressed significantly higher IgA levels, had histologically more often fatty liver changes, and risk factors for non-alcoholic steatohepatitis predominated (56% compared with 3% in the other groups, P=0.01). The hepatitic-like group (ALT 2-18 x ULN) showed histologically features of chronic hepatitis or hepatitic cirrhosis, and only among these patients a median International Autoimmune Hepatitis (IAH) score of 13 was found suggesting autoimmune hepatitis (AiH). In the cholestatic group (AP 2-8 x ULN) histology was compatible with a non-toxic inflammatory process but IAH score excluded AiH in all. After OLT, actuarial graft and patients survival was 90% at 5 years. Mild or moderate graft hepatitis occurred in 9 patients (23%) and was significantly associated with a pre-OLT IAH score >or= 10 (P =0.008). This study provides arguments that cryptogenic cirrhosis is a heterogeneous disease in which autoimmune mechanisms might be predominately involved and being responsible for recurrence of chronic liver disease observed in some instances after OLT.

  6. Clinical outcomes of liver transplantation for HBV-related hepatocellular carcinoma: data from the NIH HBV OLT study.

    PubMed

    Han, Steven-Huy; Reddy, K Rajender; Keeffe, Emmet B; Soldevila-Pico, Consuelo; Gish, Robert; Chung, Raymond T; Degertekin, Bulent; Lok, Anna

    2011-01-01

    Hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) is an indication for orthotopic liver transplantation (OLT) in patients with tumor stage within the United Network for Organ Sharing criteria. The number of patients listed for HBV-related HCC is increasing, while the number of patients listed for HBV-related cirrhosis is declining presumptively because of the availability of more effective oral nucleos(t)ide analogues. This study presents the final, long-term outcome of patients transplanted for HBV-related HCC in the National Institutes of Health (NIH) HBV OLT Study Group. Ninety-eight patients (52.4%) in the NIH HBV OLT cohort underwent OLT for HBV-related HCC. With a mean follow-up of 36.5 months post-OLT, 12 (12.2%) patients developed recurrence of HCC. Multivariate analysis did not find a statistically significant role of gender, tumor stage at OLT, pre-OLT HCC treatment, recurrence of HBV, or duration of HCC diagnosis pre-OLT in predicting HCC recurrence. Serum alpha-fetoprotein (AFP) level >200 ng/mL at transplant was found to be statistically significant in predicting HCC recurrence (p=0.003). HCC recurrence was significantly associated with decreased post-OLT survival. HCC is the most common indication for OLT in patients with chronic hepatitis B in the era of more effective oral antivirals. Serum AFP at the time of OLT is significantly associated with HCC recurrence. © 2010 John Wiley & Sons A/S.

  7. OLT-centralized sampling frequency offset compensation scheme for OFDM-PON.

    PubMed

    Chen, Ming; Zhou, Hui; Zheng, Zhiwei; Deng, Rui; Chen, Qinghui; Peng, Miao; Liu, Cuiwei; He, Jing; Chen, Lin; Tang, Xionggui

    2017-08-07

    We propose an optical line terminal (OLT)-centralized sampling frequency offset (SFO) compensation scheme for adaptively-modulated OFDM-PON systems. By using the proposed SFO scheme, the phase rotation and inter-symbol interference (ISI) caused by SFOs between OLT and multiple optical network units (ONUs) can be centrally compensated in the OLT, which reduces the complexity of ONUs. Firstly, the optimal fast Fourier transform (FFT) size is identified in the intensity-modulated and direct-detection (IMDD) OFDM system in the presence of SFO. Then, the proposed SFO compensation scheme including phase rotation modulation (PRM) and length-adaptive OFDM frame has been experimentally demonstrated in the downlink transmission of an adaptively modulated optical OFDM with the optimal FFT size. The experimental results show that up to ± 300 ppm SFO can be successfully compensated without introducing any receiver performance penalties.

  8. Incidence, risk factors and ERCP outcome for biliary complications after cadaveric OLT.

    PubMed

    Martins, Fernanda Prata; De Paulo, Gustavo Andrade; Conceição, Raquel Dilgerian; Zurstrassen, Maria Paula; Thomé, Tadeu; Ferraz-Neto, Ben-Hur; Ferrari, Angelo Paulo

    2011-01-01

    Biliary complications (BC) occur in up to 39.5% of patients after orthotopic liver transplantation (OLT), being an important source of post-transplant morbidity. The aim is to evaluate the incidence of BC after OLT, associated risk factors and outcome after endoscopic treatment. A retrospective case series between June 2005 and December 2008, including 195 patients that underwent 216 OLT from deceased donors. Thirty-one patients (14.3%) presented at least 1 BC, anastomotic stricture being the most frequent (83.8%). Non-anastomotic stricture was present in 1 (3.2%) and anastomotic fistula in 1. One patient presented anastomotic disconnection at ERCP. BC occurred 94.6 (7-487) days after OLT. Twenty-seven patients underwent endoscopic treatment, on average 2.6 ERCPs were performed per patient. Global endoscopic treatment success rate was 77.3%; being 73.7% for stenosis and 100% (3/3) for anastomotic fistula with stenosis. Recurrence of biliary stricture was observed in 3 patients, all referred to endoscopic re-treatment. ERCP complications: 2 (2.8%) stent migrations, 1 (1.4%) early stent occlusion, 1 (1.4%) respiratory distress and 1(1.4%) severe acute pancreatitis and death. There was no correlation between studied risk factors and BC's occurrence. ERCP was effective for the treatment of BC after OLT. Studied risk factors had no correlation with BC.

  9. [To evaluate the role of OLT on splenomegaly of portal hypertension by the radiological changes of splenic morphology and collaterals].

    PubMed

    Liang, Ying-ying; Wang, Jin; Shan, Hong; Yan, Rong-hua; Hu, Bing; Jiang, Zai-bo; He, Bing-jun; Liu, Jing-jing; Ren, Ling-lan; Shao, Shuo

    2012-11-20

    To explore the effect of orthotopic liver transplantation (OLT) on portal hypertension by observing the radiological changes of splenic volume and collaterals before and after OLT. In our hospital 56 patients performing OLT due to cirrhosis, portal hypertension and splenomegaly were classified into five groups according to their following-up time: A (≤3 months), B (>3-6 months), C (>6-12 months), D (>12-24 months), and E (>24 months). Twenty health people were chose as control group (F). The splenic width, thickness, length, volume, diameter of portal and splenic vein and collaterals were measured and observed in every patient of six groups before and after OLT respectively. After OLT, the splenic volume decreased by 25.4%, 27.8%, 21.9%, 25.2%, 27.7% in five groups respectively, which was still larger than the normal group (P<0.05). Gastroesophageal varices in 31 cases (81.6%, 31/36) became normal after OLT. The opened umbilical vein disappeared and the retroperitoneal varices persisted in five cases after OLT. Splenomegaly and opened collaterals can be relieved by OLT effectively. The splenic volume didn't change obviously until it decreased by 25% in the three months after OLT. Gastroesophageal varices can be removed in most of patients after OLT. The splenomegaly could last paralled with the splenic vein and retroperitoneal varices after OLT. After OLT, correct disposal of splenic and collateral changes could improve the success rate and the long-term treatment effect of OLT.

  10. Efficient traffic grooming with dynamic ONU grouping for multiple-OLT-based access network

    NASA Astrophysics Data System (ADS)

    Zhang, Shizong; Gu, Rentao; Ji, Yuefeng; Wang, Hongxiang

    2015-12-01

    Fast bandwidth growth urges large-scale high-density access scenarios, where the multiple Passive Optical Networking (PON) system clustered deployment can be adopted as an appropriate solution to fulfill the huge bandwidth demands, especially for a future 5G mobile network. However, the lack of interaction between different optical line terminals (OLTs) results in part of the bandwidth resources waste. To increase the bandwidth efficiency, as well as reduce bandwidth pressure at the edge of a network, we propose a centralized flexible PON architecture based on Time- and Wavelength-Division Multiplexing PON (TWDM PON). It can provide flexible affiliation for optical network units (ONUs) and different OLTs to support access network traffic localization. Specifically, a dynamic ONU grouping algorithm (DGA) is provided to obtain the minimal OLT outbound traffic. Simulation results show that DGA obtains an average 25.23% traffic gain increment under different OLT numbers within a small ONU number situation, and the traffic gain will increase dramatically with the increment of the ONU number. As the DGA can be deployed easily as an application running above the centralized control plane, the proposed architecture can be helpful to improve the network efficiency for future traffic-intensive access scenarios.

  11. A point-based prediction model for cardiovascular risk in orthotopic liver transplantation: The CAR-OLT score.

    PubMed

    VanWagner, Lisa B; Ning, Hongyan; Whitsett, Maureen; Levitsky, Josh; Uttal, Sarah; Wilkins, John T; Abecassis, Michael M; Ladner, Daniela P; Skaro, Anton I; Lloyd-Jones, Donald M

    2017-12-01

    Cardiovascular disease (CVD) complications are important causes of morbidity and mortality after orthotopic liver transplantation (OLT). There is currently no preoperative risk-assessment tool that allows physicians to estimate the risk for CVD events following OLT. We sought to develop a point-based prediction model (risk score) for CVD complications after OLT, the Cardiovascular Risk in Orthotopic Liver Transplantation risk score, among a cohort of 1,024 consecutive patients aged 18-75 years who underwent first OLT in a tertiary-care teaching hospital (2002-2011). The main outcome measures were major 1-year CVD complications, defined as death from a CVD cause or hospitalization for a major CVD event (myocardial infarction, revascularization, heart failure, atrial fibrillation, cardiac arrest, pulmonary embolism, and/or stroke). The bootstrap method yielded bias-corrected 95% confidence intervals for the regression coefficients of the final model. Among 1,024 first OLT recipients, major CVD complications occurred in 329 (32.1%). Variables selected for inclusion in the model (using model optimization strategies) included preoperative recipient age, sex, race, employment status, education status, history of hepatocellular carcinoma, diabetes, heart failure, atrial fibrillation, pulmonary or systemic hypertension, and respiratory failure. The discriminative performance of the point-based score (C statistic = 0.78, bias-corrected C statistic = 0.77) was superior to other published risk models for postoperative CVD morbidity and mortality, and it had appropriate calibration (Hosmer-Lemeshow P = 0.33). The point-based risk score can identify patients at risk for CVD complications after OLT surgery (available at www.carolt.us); this score may be useful for identification of candidates for further risk stratification or other management strategies to improve CVD outcomes after OLT. (Hepatology 2017;66:1968-1979). © 2017 by the American Association for the Study of Liver

  12. [Evolution of endemic tuberculosis in Olt county, Romania, between 1990 and 2008].

    PubMed

    Golli, Andreea-Loredana; Didilescu, C; Niţu, Mimi-Floarea; Eparu, Ion

    2011-01-01

    A world-wide recrudescence of tuberculosis has been seen, due to the deterioration of the health state of the population from many areas of the world, because of increasing number of homeless persons, and also the immigrants from countries with TB epidemic. The present epidemiological context draw attention to the necessity of early detection of the disease and the beginning of early directly observed treatment, preferably ambulatory, if the sick person doesn't have other complications, isn't infected with multidrog resistant bacili and lives in a properly social environment for his support. For the evaluation of tuberculosis epidemic in Olt county, the authors realised a retrospective study on a period of over 15 years (1990-2008), based on the analysis of the main epidemiological indices of TB epidemic in this county compared with Romania: global incidence both in adults and children, for new cases nd relapses apart, incidence of MDR-TB (multidrug resistant-tuberculosis) cases, mortality through tuberculosis. Global incidence of TB in Olt county almost doubled between 1990-2008, reaching 147, 4 per hundred thousand, with much higher values compared with the national ones. Olt county presents constant values over the national ones between 1995-2008, due to the global incidence and also to the new cases and relapses. The incidence of new cases in children in 2008 (20,4 per hundred thousand) was below the national level (28 per hundred thousand). The risk of illness for the 0-14 years old children from Olt county was significantly lower in 2008 compared with the previous year, which, toghether with a number of MDR-TB cases under 15, signifies a regress of the epidemic.

  13. De-novo cholangiocarcinoma in native common bile duct remnant following OLT for primary sclerosing cholangitis.

    PubMed

    Landaverde, Carmen; Ng, Vivian; Sato, Alisa; Tabibian, James; Durazo, Francisco; Busuttil, Ronald

    2009-01-01

    Primary sclerosing cholangitis (PSC) is a chronic, progressive, inflammatory and obstructive disease of the intra- and extra-hepatic bile ducts of unknown etiology. Currently, orthotopic liver transplantation (OLT) is the only definitive treatment for PSC-related end-stage liver disease. However, PSC has been known to recur in the grafted liver. Roux-en-Y hepaticojejunostomy is more commonly performed than choledochocholedochostomy for PSC, although choledochocholedochostomy has been found to be safe and efficacious for PSC if the distal common bile duct is uninvolved at the time of OLT. Our case is unique in that it describes a patient who developed de-novo cholangiocarcinoma in the remnant portion of the native common bile duct six years after OLT with choledochocholedochostomy for PSC-associated end-stage liver disease without having PSC recurrence. In conclusion, our case report indicates that choledochocholedochostomy may not be desirable in PSC due to an increased risk of developing cholangiocarcinoma in the native common bile duct. This risk exists as well with a Roux-en-Y hepaticojejunostomy in the remaining intra-duodenal and intra-pancreatic biliary epithelium, although in theory to a lesser extent. Therefore, the risk of developing cholangiocarcinoma in the recipient common bile duct can only be completely eliminated by performing a Whipple procedure at the time of OLT.

  14. Bone mineral density before and after OLT: long-term follow-up and predictive factors.

    PubMed

    Guichelaar, Maureen M J; Kendall, Rebecca; Malinchoc, Michael; Hay, J Eileen

    2006-09-01

    Fracturing after liver transplantation (OLT) occurs due to the combination of preexisting low bone mineral density (BMD) and early posttransplant bone loss, the risk factors for which are poorly defined. The prevalence and predictive factors for hepatic osteopenia and osteoporosis, posttransplant bone loss, and subsequent bone gain were studied by the long-term posttransplant follow-up of 360 consecutive adult patients with end-stage primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC). Only 20% of patients with advanced PBC or PSC have normal bone mass. Risk factors for low spinal BMD are low body mass index, older age, postmenopausal status, muscle wasting, high alkaline phosphatase and low serum albumin. A high rate of spinal bone loss occurred in the first 4 posttransplant months (annual rate of 16%) especially in those with younger age, PSC, higher pretransplant bone density, no inflammatory bowel disease, shorter duration of liver disease, current smoking, and ongoing cholestasis at 4 months. Factors favoring spinal bone gain from 4 to 24 months after transplantation were lower baseline and/or 4-month bone density, premenopausal status, lower cumulative glucocorticoids, no ongoing cholestasis, and higher levels of vitamin D and parathyroid hormone. Bone mass therefore improves most in patients with lowest pretransplant BMD who undergo successful transplantation with normal hepatic function and improved gonadal and nutritional status. Patients transplanted most recently have improved bone mass before OLT, and although bone loss still occurs early after OLT, these patients also have a greater recovery in BMD over the years following OLT.

  15. Ventral incisional hernia (VIH) repair after liver transplantation (OLT) with a biological mesh: experience in 3 cases.

    PubMed

    Schaffellner, S; Sereinigg, M; Wagner, D; Jakoby, E; Kniepeiss, D; Stiegler, P; Haybäck, J; Müller, H

    2016-05-01

    Hernias after orthotopic liver transplant (OLT) occur in about 30 % of cases. Predisposing factors in liver cirrhotic patients of cases are ascites, low abdominal muscle mass and cachexia before and immunosuppression after OLT. Standard operative transplant-technique even in small hernias is to implant a mesh. For patients after liver transplantation a porcine non-cross linked biological patch being less immunogenic than synthetic and cross-linked meshes is chosen for ventral incisional hernia repair. 3 patients (1 female, 2 male), OLT indications Hepatitis C, exogenous- toxic cirrhosis, median-age 53 (51 - 56) and median time to hernia occurrence after OLT were 10 month (6 - 18 m) are documented. 2 patients suffered from diabetes, 2 from chronic-obstructive lung disease. Maintenance immunosuppressions were Everolimus in 1 patient, Everolimus + MMF in the second and Everolimus +Tacrolimus in the third patient. The biological was chosen for hernia repair due to the preexisting risk- factors. Meshes, 10 × 16 cm were placed, in IPOM (Intra-Peritonel-Onlay-Mesh) -position by relaparatomy. Insolvable, monofile, interrupted sutures were used. All patients recovered primarily, and were dismissed within 10 d post OP. No wound healing disorders or signs of postoperative infections occurred. All are free of hernia recurrence in a mean observation time of 22 month (10 - 36). The usage of porcine non-cross-linked biological patches seems feasible for incisional hernia repair after OLT. Wound infections in these patients have been observed with other meshes. Further investigation is needed to prove potential superiority of this biological to the other meshes. © Georg Thieme Verlag KG Stuttgart · New York.

  16. Is there any difference in anesthetic management of different post-OLT stage patients undergoing nontransplant organ surgery?

    PubMed

    Feng, Zhi-Ying; Zhang, Jian; Zhu, Sheng-Mei; Zheng, Shu-Sen

    2006-08-01

    Little information is available about anesthesia management of nontransplant organ surgery of recipients after adult liver transplantation. The aim of this study was to discuss the anesthesia management of recipients for different stages after liver transplantation. The medical records of 16 patients were reviewed after OLT scheduled for elective nontransplant organ surgery at our institution from September 2002 to October 2005. The patients were divided into perioperative stage (group A) and mid-term and long-term stage (group B) groups according to post-OLT time. The data of 16 patients preoperation, intraoperation and postoperation were analyzed. The measurements of alanine transaminase (ALT), total bilirubin (TB), prothrombin time (PT), and lung infection were significantly higher in group A than in group B (P<0.05). The incidence of hyperglycaemia was significantly higher in group B than in group A (P<0.05). During operation the incidence of hypotension was significantly higher in group A than in group B (P<0.05). After operation, the number of patients in ICU was significantly larger and the extubation time was longer in group A than in group B. General anesthesia was induced in 14 patients, and regional anesthesia in 2 patients. Regional or general anesthesia can be safely delivered to adult OLT recipients except for contraindications. Special considerations include protection of the function of important organs, correction of hemodynamic instability in perioperative stage patients after OLT, and measurement of the side-effects of immunosuppression in mid-term and long-term stage patients.

  17. How do we manage post-OLT redundant bile duct?

    PubMed

    Torres, Victor; Martinez, Nicholas; Lee, Gabriel; Almeda, Jose; Gross, Glenn; Patel, Sandeep; Rosenkranz, Laura

    2013-04-28

    To address endoscopic outcomes of post-Orthotopic liver transplantation (OLT) patients diagnosed with a "redundant bile duct" (RBD). Medical records of patients who underwent OLT at the Liver Transplant Center, University Texas Health Science Center at San Antonio Texas were retrospectively analyzed. Patients with suspected biliary tract complications (BTC) underwent endoscopic retrograde cholangiopancreatography (ERCP). All ERCP were performed by experienced biliary endoscopist. RBD was defined as a looped, sigmoid-shaped bile duct on cholangiogram with associated cholestatic liver biomarkers. Patients with biliary T-tube placement, biliary anastomotic strictures, bile leaks, bile-duct stones-sludge and suspected sphincter of oddi dysfunction were excluded. Therapy included single or multiple biliary stents with or without sphincterotomy. The incidence of RBD, the number of ERCP corrective sessions, and the type of endoscopic interventions were recorded. Successful response to endoscopic therapy was defined as resolution of RBD with normalization of associated cholestasis. Laboratory data and pertinent radiographic imaging noted included the pre-ERCP period and a follow up period of 6-12 mo after the last ERCP intervention. One thousand two hundred and eighty-two patient records who received OLT from 1992 through 2011 were reviewed. Two hundred and twenty-four patients underwent ERCP for suspected BTC. RBD was reported in each of the initial cholangiograms. Twenty-one out of 1282 (1.6%) were identified as having RBD. There were 12 men and 9 women, average age of 59.6 years. Primary indication for ERCP was cholestatic pattern of liver associated biomarkers. Nineteen out of 21 patients underwent endoscopic therapy and 2/21 required immediate surgical intervention. In the endoscopically managed group: 65 ERCP procedures were performed with an average of 3.4 per patient and 1.1 stent per session. Fifteen out of 19 (78.9%) patients were successfully managed with

  18. Impact of UCSF criteria according to pre- and post-OLT tumor features: analysis of 479 patients listed for HCC with a short waiting time.

    PubMed

    Decaens, Thomas; Roudot-Thoraval, Françoise; Hadni-Bresson, Solange; Meyer, Carole; Gugenheim, Jean; Durand, Francois; Bernard, Pierre-Henri; Boillot, Olivier; Sulpice, Laurent; Calmus, Yvon; Hardwigsen, Jean; Ducerf, Christian; Pageaux, Georges-Philippe; Dharancy, Sebastien; Chazouilleres, Olivier; Cherqui, Daniel; Duvoux, Christophe

    2006-12-01

    Orthotopic liver transplantation (OLT) indication for hepatocellular carcinoma (HCC) is currently based on the Milan criteria. The University of California, San Francisco (UCSF) recently proposed an expansion of the selection criteria according to tumors characteristics on the explanted liver. This study: 1) assessed the validity of these criteria in an independent large series and 2) tested for the usefulness of these criteria when applied to pre-OLT tumor evaluation. Between 1985 and 1998, 479 patients were listed for liver transplantation (LT) for HCC and 467 were transplanted. According to pre-OLT (imaging at date of listing) or post-OLT (explanted liver) tumor characteristics, patients were retrospectively classified according to both the Milan and UCSF criteria. The 5-yr survival statistics were assessed by the Kaplan-Meier method and compared by the log-rank test. Pre-OLT UCSF criteria were analyzed according to an intention-to-treat principle. Based on the pre-OLT evaluation, 279 patients were Milan+, 44 patients were UCSF+ but Milan- (subgroup of patients that might benefit from the expansion), and 145 patients were UCSF- and Milan-. With a short median waiting time of 4 months, 5-yr survival was 60.1 +/- 3.0%, 45.6 +/- 7.8%, and 34.7 +/- 4.0%, respectively (P < 0.001). The 5-yr survival was arithmetically lower in UCSF+ Milan- patients compared to Milan+ but this difference was not significant (P = 0.10). Based on pathological features of the explanted liver, 5-yr survival was 70.4 +/- 3.4%, 63.6 +/- 7.8%, and 34.1 +/- 3.1%, in Milan+ patients (n = 184), UCSF+ Milan- patients (n = 39), and UCSF- Milan- patients (n = 238), respectively (P < 0.001). However, the 5-yr survival did not differ between Milan+ and UCSF+ Milan- patients (P = 0.33). In conclusion, these results show that when applied to pre-OLT evaluation, the UCSF criteria are associated with a 5-yr survival below 50%. Their applicability is therefore limited, despite similar survival rates

  19. Success and complications of an intra-ductal fully covered self-expanding metal stent (ID-FCSEMS) to treat anastomotic biliary strictures (AS) after orthotopic liver transplantation (OLT).

    PubMed

    Aepli, Patrick; St John, Andrew; Gupta, Saurabh; Hourigan, Luke F; Vaughan, Rhys; Efthymiou, Marios; Kaffes, Arthur

    2017-04-01

    Anastomotic biliary strictures (AS) after orthotopic liver transplantation (OLT) belong to the most common biliary complications and cause the biggest morbidity burden after OLT. Metal stents for benign biliary strictures are gaining acceptance with many published series. Traditional metal stent designs seem to have poor durability in AS after OLT. Novel intra-ductal stents are showing promise in these strictures. As a result, we designed a special stent with an antimigration waist and a short stent length with a long removal string that rests in the duodenum for easy removal. This is a retrospective multi-centre Australian study of AS after OLT treated with a novel intra-ductal fully covered self-expanding metal stent. From August 2008 to October 2014, records from three liver transplant centres were reviewed. Totally 36 ID-FCSEMS were inserted in 31 cases to treat an AS after OLT. The mean age of the patients was 56 years, and 61 % were male. The mean time of AS presentation after OLT was 20.3 months. Eight out of our 31 patients were previously treated using multiple plastic stenting over time without any success. Treatment with the ID-FCSEMS was performed with an average treatment time of 3.8 months. Stricture resolution was achieved in 100 %. All attempted stents removals were successful without any difficulty. Complications were reported in 6.5 %. It was pleasing that only one case of stent migration (2.8 %) was seen. Follow-up showed seven cases of AS recurrence (24.1 %), and all were treated successfully with repeat ERCP and stenting (some metal, some plastic). This novel ID-FCSEMS has a high clinical success and low complication rate, and in particular, there was only one case of stent migration. As a result, this stent type is preferred to traditional metal stents for treating AS after OLT.

  20. Virtualized Networks and Virtualized Optical Line Terminal (vOLT)

    NASA Astrophysics Data System (ADS)

    Ma, Jonathan; Israel, Stephen

    2017-03-01

    The success of the Internet and the proliferation of the Internet of Things (IoT) devices is forcing telecommunications carriers to re-architecture a central office as a datacenter (CORD) so as to bring the datacenter economics and cloud agility to a central office (CO). The Open Network Operating System (ONOS) is the first open-source software-defined network (SDN) operating system which is capable of managing and controlling network, computing, and storage resources to support CORD infrastructure and network virtualization. The virtualized Optical Line Termination (vOLT) is one of the key components in such virtualized networks.

  1. Early diagnostic value of plasma PCT and BG assay for CRBSI after OLT.

    PubMed

    Chen, J; Wang, Y; Shen, Z; Zhu, Z; Song, Y; Han, R

    2011-06-01

    The aim was to evaluate the role of procalcitonin (PCT) and (1-3)-β-D-glucan (BG) tests for early detection or exclusion of central venous catheter-related bloodstream infections (CRBSI) in patients after orthotopic liver transplantation (OLT). Fifty-five patients with clinically suspected CRBSI were assessed after OLT in this prospective study. On the day of clinical suspicion of CRBSI, blood samples were obtained from central venous catheters and a peripheral vein for blood cultures and from a peripheral vein for PCT and BG tests. Plasma PCT and BG values were measured by using an immunoluminometric assay and Fungitell BG assay, respectively. No prisoners or organs from prisoners were used in this study. Twenty-five patients (45%) were diagnosed with CRBIS. Among them, 13 (52%) displayed gram-positive bacteriemia, 11 (44%) gram-negative bacteriemia, and 1 (4%) fungemia. The PCT values were higher in CRBSI than in non-CRBSI patients (P = .003). CRBSI patients did not show significant increases in plasma BG values compared with non-CRBSI subjects (P = .051). PCT and BG area under receiver operating characteristic curves were 0.840 and 0.486, respectively. Sensitivity, specificity, and positive and negative predictive values of a PCT of ≥ 3.1 ng/mL for the diagnosis of CRBSI were 0.72, 0.87, 0.82, and 0.79, respectively. The figures for a BG of ≥ 83 pg/mL were 0.32, 0.90, 0.73, and 0.61, respectively. Among the 24 patients with bacteria infections, PCT was higher in patients with gram-negative than those with gram-positive bacterial infections (P = .022). We concluded that the PCT assay may be a useful rapid diagnostic adjunct for the diagnosis of suspected CRBSI in OLT patients. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. New species of Ipomoea (Convolvulaceae) from South America

    PubMed Central

    Wood, John R.I.; Muñoz-Rodríguez, Pablo; Degen, Rosa; Scotland, Robert W.

    2017-01-01

    Abstract The importance of discovering, describing and cataloguing poorly known species in herbarium collections is discussed. It is a spur to efforts at rediscovery and consequent conservation efforts. The problems faced in describing species from limited material are discussed and our methods and criteria in making a decision are described. Prospects for future novelties are briefly assessed. Fifteen new species are described and illustrated with line drawings and distribution maps: Ipomoea attenuata J.R.I. Wood & Scotland, I. cuscoensis J.R.I. Wood & P. Muñoz, I. dasycarpa J.R.I. Wood & Scotland, I. dolichopoda J.R.I. Wood & R. Degen, I. ensiformis J.R.I.Wood & Scotland, I. fasciculata J.R.I. Wood & Scotland, I. graminifolia J.R.I. Wood & Scotland, I. kraholandica J.R.I. Wood & Scotland, I. longirostra J.R.I. Wood & Scotland, I. revoluta J.R.I. Wood & Scotland, I. scopulina J.R.I. Wood &. Scotland, I. uninervis J.R.I. Wood & Scotland, I. veadeirosii J.R.I. Wood & Scotland, I. velutinifolia J.R.I. Wood & Scotland, I. walteri J.R.I. Wood & Scotland. All species are narrow endemics except I. velutinifolia which is found in Brazil and Peru; of the others, 12 are found in Brazil and one each in Paraguay and Peru. PMID:29118645

  3. Successful Pregnancies in Two Orthotopic Liver Transplant (OLT) Recipients in Iran; Two Case Reports.

    PubMed

    Zahra, Tayebi; Seyyed Alireza, Taqhavi; Shirin, Shahbazi

    2009-10-01

    Pregnancy and parenting have been part of human life throughout history and liver transplant recipients are not any exception. This paper reports successful pregnancies in two liver transplant recipients in Iran. The first case was a 34-year old woman who had undergone orthotopic liver transplantation (OLT) at Shiraz Namazi Educational Hospital in 2002. She decided to get pregnant seven years after the operation. During pregnancy, immunosuppressive therapy continued, except Mycophenolate Mofetil which has an absolute contra-indication in pregnancy. The patient was followed up during pregnancy by the transplant team as well as a gynecologist. She faced no significant complications and the liver function was stable during pregnancy. She later underwent a Cesarean section in the 38(th) week of gestation and the newborn was a healthy girl weighing 2480g with an Apgar score of 8 at the time of birth. There were no evidences of prematurity or structural abnormalities in the newborn. The second case was a 31-year old primipara who had received an orthotopic liver transplant (OLT) in Shiraz in 2002. She had a smooth pregnancy without any complications and the newborn was a boy weighing 3100g with Apgar scores of 8 and 10 at the time of birth and 5 minutes thereafter, respectively. As the number of transplant recipients is growing along with the number of recipients who are in their fertility years, it is vital to ensure a proper medical care by a coordinated multidisciplinary team during pregnancy.

  4. Clinical values of AFP, GPC3 mRNA in peripheral blood for prediction of hepatocellular carcinoma recurrence following OLT: AFP, GPC3 mRNA for prediction of HCC.

    PubMed

    Wang, Yuliang; Shen, Zhongyang; Zhu, Zhijun; Han, Ruifa; Huai, Mingsheng

    2011-03-01

    Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. Annually, about 200,000 patients died of HCC in China. Liver transplantation (LT) holds great theoretical appeal in treating HCC. However, the high recurrence rate after transplantation is the most important limiting factor for long-term survival. To assess the value of alpha-fetoprotein (AFP) messenger RNA (mRNA), Glypican-3 (GPC3) mRNA-expressing cells in the peripheral blood (PB) for prediction of HCC recurrence following orthotopic liver transplantation (OLT). 29 patients with HCC who underwent OLT with a minimum clinical follow-up of 12 months were included in this retrospective study. We detected AFP mRNA, GPC3 mRNA-expressing cells in the PB by TaqMan real-time reverse transcriptase-polymerase chain reaction (RT-PCR), pre-, intra- and post-operatively. The early recurrence of patients was evaluated. 8 (28%), 15 (52%), and 9 (31%) patients had AFP mRNA detected pre-, intra-, and post-operatively, respectively. With 12 months of follow-up, HCC recurred in 7 (24%) patients. Univariate analysis revealed that positive pre- and post-operative AFP mRNA, TNM stage as well as vascular invasion were significant predictors for the HCC recurrence. Multivariate analysis revealed that being positive for AFP mRNA pre-operatively remained a significant risk factor for HCC recurrence after OLT. GPC3 mRNA was expressed in all PB samples. There was no significant difference in the expression levels of GPC3 mRNA between the HCC and control groups. There were no significant differences in GPC3 mRNA expression values between those patients with and without tumor recurrence. The pre-operative detection of circulating AFP mRNA-expressing cells could be a useful predictor for HCC recurrence following OLT. GPC3 mRNA-expressing cells in PB seem to have no diagnostic value.

  5. Management of end stage liver disease (ESLD): what is the current role of orthotopic liver transplantation (OLT)?

    PubMed

    Miró, José M; Laguno, Montserrat; Moreno, Asuncion; Rimola, Antonio

    2006-01-01

    Liver disease due to chronic hepatitis B and C is now a leading cause of morbidity and mortality among HIV-infected patients in the developed world, where classical opportunistic complications of severe immunodeficiency have declined dramatically. Orthotopic liver transplantation (OLT) is the only therapeutic option for patients with end-stage liver disease (ESLD). Accumulated experience in North America and Europe in the last 5 years indicates that 3-year survival in selected HIV-infected recipients of liver transplants was similar to that of HIV-negative recipients. So, HIV infection by itself is not therefore a contraindication for liver transplantation. As survival of HIV-infected patients with ESLD is shorter than non-HIV-infected population, the evaluation for OLT should be made after the first liver decompensation. The current selection criteria for HIV-positive transplant candidates include: no history of opportunistic infections or HIV-related neoplasms, CD4 cell count > 100 cells/mm(3), and plasma HIV viral load suppressible with antiretroviral treatment. For drug abusers, a 2-year abstinence from heroin and cocaine is required, although patients can be in a methadone programme. The main problems in the post-transplant period are pharmacokinetic and pharmacodynamic interactions between antiretrovirals and immunosuppressive drugs, and the management of relapse of HCV infection. Up to now, experience with pegylated interferon and ribavirin is scarce in this population. Currently, HCV re-infection is the main cause for concern.

  6. Magnetic resonance cholangiography in the assessment and management of biliary complications after OLT.

    PubMed

    Girometti, Rossano; Cereser, Lorenzo; Bazzocchi, Massimo; Zuiani, Chiara

    2014-07-28

    Despite advances in patient and graft management, biliary complications (BC) still represent a challenge both in the early and delayed period after orthotopic liver transplantation (OLT). Because of unspecific clinical presentation, imaging is often mandatory in order to diagnose BC. Among imaging modalities, magnetic resonance cholangiography (MRC) has gained widespread acceptance as a tool to represent the reconstructed biliary tree noninvasively, using both the conventional technique (based on heavily T2-weighted sequences) and contrast-enhanced MRC (based on the acquisition of T1-weighted sequences after the administration of hepatobiliary contrast agents). On this basis, MRC is generally indicated to: (1) avoid unnecessary procedures of direct cholangiography in patients with a negative examination and/or identify alternative complications; and (2) provide a road map for interventional procedures or surgery. As illustrated in the review, MRC is accurate in the diagnosis of different types of biliary complications, including anastomotic strictures, non-anastomotic strictures, leakage and stones.

  7. [To the issue of postreperfusion syndrome predictors in orthotopic liver transplantation (OLT)].

    PubMed

    Kiseleva, E A; Ushakova, I A; Kim, E F; Matveev, G P; Biriulina, N Iu; Vabishchevich, A V

    2012-01-01

    The aim of the study is revelation of postperfusion syndrome (pPS) predictors in orthotopic liver transplantation (OLT). Was conducted a retrospective analysis of anesthesia maintainance protocols during orthotopic liver transplantation in 261 patients aged from 6 months to 60 years. Investigated the effect of various factors on the development of PPS by the application of methods of non-parametric statistics. Significantly more frequent development of the PPS is noted in the age group from 3 to 18 years (up to 30% of patients). In recipients older than 18 years the frequency of the development of the PPS does not depend on age, with an average of 14%. The development of the PPS does not depend on the recipient sex, the nature of the pathology which served as an indication to the OTP, the initial severity of the state, type of OTP (living related donor or cadaveric transplantation, primary or re-transplantation), the transplant warm ischemia duration, use, or the lack of venous-venous bypass, metabolic status of the patient. The obtained results do not contradict to the data of foreign publications. Among parameters available for screening, predictor of PPS was not detected.

  8. Using stable isotopes in tracing contaminant sources in an industrial area: A case study on the hydrological basin of the Olt River, Romania.

    PubMed

    Popescu, Raluca; Mimmo, Tanja; Dinca, Oana Romina; Capici, Calogero; Costinel, Diana; Sandru, Claudia; Ionete, Roxana Elena; Stefanescu, Ioan; Axente, Damian

    2015-11-15

    Tracing pollution sources and transformation of nitrogen compounds in surface- and groundwater is an issue of great significance worldwide due to the increased human activity, translated in high demand of water resources and pollution. In this work, the hydrological basin of an important chemical industrial platform in Romania (Ramnicu Valcea industrial area) was characterized in terms of the physico-chemical and isotope composition of δ(18)O and δ(2)H in water samples and δ(15)N of the inorganic nitrogen species. Throughout a period of one year, water samples from the Olt River and its more important tributaries were collected monthly in the industrial area, when the seasonal and spatial isotope patterns of the surface waters and the main sources of pollution were determined. Higher inorganic nitrogen concentrations (up to 10.2 mg N L(-1)) were measured between November 2012 and April 2013, which were designated as anthropogenic additions using the mixing calculations. The main sources of pollution with inorganic nitrogen were agriculture and residential release. The inorganic nitrogen from the industrial waste water duct had a distinct δ(15)N fingerprint (mean of -8.6‰). Also, one industrial release into the environment was identified for Olt River, at Ionesti site, in November 2012. The mean precipitation samples had the lowest inorganic nitrogen concentrations (less than 5.5 mg N L(-1)) with a distinct δ(15)N fingerprint compared to the surface and industrial waters. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Demonstration of Laser Plasma X-Ray Source with X-Ray Collimator Final Report CRADA No. TC-1564-99

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

    Lane, S. M.; Forber, R. A.

    2017-09-28

    This collaborative effort between the University of California, Lawrence Livermore National Laboratory (LLNL) and JMAR Research, Inc. (JRI), was to demonstrate that LLNL x-ray collimators can effectively increase the wafer throughput of JRI's laser based x-ray lithography systems. The technical objectives were expected to be achieved by completion of the following tasks, which are separated into two task lists by funding source. The organization (LLNL or JMAR) having primary responsibility is given parenthetically for each task.

  10. Biofilm composition in the Olt River (Romania) reservoirs impacted by a chlor-alkali production plant.

    PubMed

    Dranguet, P; Cosio, C; Le Faucheur, S; Hug Peter, D; Loizeau, J-L; Ungureanu, V-Gh; Slaveykova, V I

    2017-05-24

    Freshwater biofilms can be useful indicators of water quality and offer the possibility to assess contaminant effects at the community level. The present field study examines the effects of chlor-alkali plant effluents on the community composition of biofilms grown in the Olt River (Romania) reservoirs. The relationship between ambient water quality variables and community composition alterations was explored. Amplicon sequencing revealed a significant modification of the composition of microalgal, bacterial and fungal communities in the biofilms collected in the impacted reservoirs in comparison with those living in the uncontaminated control reservoir. The abundance corrected Simpson index showed lower richness and diversity in biofilms collected in the impacted reservoirs than in the control reservoir. The biofilm bacterial communities of the impacted reservoirs were characterized by the contaminant-tolerant Cyanobacteria and Bacteroidetes, whereas microalgal communities were predominantly composed of Bacillariophyta and fungal communities of Lecanoromycetes and Paraglomycetes. A principal component analysis revealed that major contaminants present in the waste water of the chlor-alkali production plant, i.e. Na + , Ca 2+ , Cl - and Hg, were correlated with the alteration of biofilm community composition in the impacted reservoirs. However, the biofilm composition was also influenced by water quality variables such as NO 3 - , SO 4 2- , DOC and Zn from unknown sources. The results of the present study imply that, even when below the environmental quality standards, typical contaminants of chlor-alkali plant releases may affect biofilm composition and that their impacts on the microbial biodiversity might be currently overlooked.

  11. Refracted Acoustic Communications in Wireless Underwater Sensor Networks with Mobility

    DTIC Science & Technology

    2015-07-01

    presented in ( Nicolaou et al., 2007). Depth measurement ca- pability is assumed in depth-based routing schemes (Hasannezhad et al., 2014). Awareness of...Ri cosαk )2 = (di j Ri tanαk)2+(Δzi j+Ri)2 R2i cos2αk = d2i j 2di jRi tanαk+R 2 i tan 2αk+ . . . (Δzi j)2+2Δzi jRi+R2i Grouping all R2i terms on the...1754–1757. Lurton, X. (2010). An Introduction to Underwater Acoustics. Springer-Verlag, Berlin, 2nd edition. Nicolaou , N., See, A., Cui, J., and

  12. Logical optical line terminal technologies towards flexible and highly reliable metro- and access-integrated networks

    NASA Astrophysics Data System (ADS)

    Okamoto, Satoru; Sato, Takehiro; Yamanaka, Naoaki

    2017-01-01

    In this paper, flexible and highly reliable metro and access integrated networks with network virtualization and software defined networking technologies will be presented. Logical optical line terminal (L-OLT) technologies and active optical distribution networks (ODNs) are the key to introduce flexibility and high reliability into the metro and access integrated networks. In the Elastic Lambda Aggregation Network (EλAN) project which was started in 2012, a concept of the programmable optical line terminal (P-OLT) has been proposed. A role of the P-OLT is providing multiple network services that have different protocols and quality of service requirements by single OLT box. Accommodated services will be Internet access, mobile front-haul/back-haul, data-center access, and leased line. L-OLTs are configured within the P-OLT box to support the functions required for each network service. Multiple P-OLTs and programmable optical network units (P-ONUs) are connected by the active ODN. Optical access paths which have flexible capacity are set on the ODN to provide network services from L-OLT to logical ONUs (L-ONUs). The L-OLT to L-ONU path on the active ODN provides a logical connection. Therefore, introducing virtualization technologies becomes possible. One example is moving an L-OLT from one P-OLT to another P-OLT like a virtual machine. This movement is called L-OLT migration. The L-OLT migration provides flexible and reliable network functions such as energy saving by aggregating L-OLTs to a limited number of P-OLTs, and network wide optical access path restoration. Other L-OLT virtualization technologies and experimental results will be also discussed in the paper.

  13. Historical record of mercury contamination in sediments from the Babeni Reservoir in the Olt River, Romania.

    PubMed

    Bravo, Andrea Garcia; Loizeau, Jean-Luc; Ancey, Lydie; Ungureanu, Viorel Gheorghe; Dominik, Janusz

    2009-08-01

    Mercury (Hg) is a ubiquitous and hazardous contaminant in the aquatic environment showing a strong biomagnification effect along the food chain. The most common transfer path of Hg to humans is contaminated fish consumption. In severely exposed humans, Hg poisoning may lead to damage in the central nervous system. Thus, it is important to examine current and past contamination levels of Hg in aquatic milieu. The Olt River is the largest Romanian tributary of the Danube River. The use of Hg as an electrode in a chlor-alkali plant contributed to the contamination of the aquatic environment in the Rm Valcea region. The purpose of this study was to compare the current state of Hg contamination with the past contamination using a historical record obtained from a dated sediment core from one of the Olt River reservoirs (Babeni) located downstream from the chlor-alkali plant. To our knowledge, no published data on Hg contamination in this region are available. The Babeni Reservoir was selected for this study because it is situated downstream from the chlor-alkali plant, whilst the other reservoirs only retain the pollutants coming from the upstream part of the watershed. Preliminary analyses (unpublished) showed high Hg concentrations in the surface sediment of the Babeni Reservoir. One core was taken in the upstream Valcea Reservoir to provide a local background level of Hg concentrations in sediments. Sediment texture was uniform in the cores from both reservoirs. Laminated sediment structure, without any obvious discontinuities, was observed. Hg concentrations in the sediment core from the Valcea Reservoir were low and constant (0.01-0.08 mg/kg). In Babeni Reservoir sediments, Hg concentrations were very high in the deeper core section (up to 45 mg/kg in the longest core) and decreased to lower concentrations toward the top of the cores (1.3-2.4 mg/kg). This decrease probably reflects technological progress in control of emissions from the Hg-cell-based chlor

  14. Hepatic encephalopathy before and neurological complications after liver transplantation have no impact on the employment status 1 year after transplantation

    PubMed Central

    Pflugrad, Henning; Tryc, Anita B; Goldbecker, Annemarie; Strassburg, Christian P; Barg-Hock, Hannelore; Klempnauer, Jürgen; Weissenborn, Karin

    2017-01-01

    AIM To investigate the impact of hepatic encephalopathy before orthotopic liver transplantation (OLT) and neurological complications after OLT on employment after OLT. METHODS One hundred and fourteen patients with chronic liver disease aged 18-60 years underwent neurological examination to identify neurological complications, neuropsychological tests comprising the PSE-Syndrome-Test yielding the psychometric hepatic encephalopathy score, the critical flicker frequency and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), completed a questionnaire concerning their occupation and filled in the short form 36 (SF-36) to assess health-related quality of life before OLT and 12 mo after OLT, if possible. Sixty-eight (59.6%) patients were recruited before OLT, while on the waiting list for OLT at Hannover Medical School [age: 48.7 ± 10.2 years, 45 (66.2%) male], and 46 (40.4%) patients were included directly after OLT. RESULTS Before OLT 43.0% of the patients were employed. The patients not employed before OLT were more often non-academics (employed: Academic/non-academic 16 (34.0%)/31 vs not employed 10 (17.6%)/52, P = 0.04), had more frequently a history of hepatic encephalopathy (HE) (yes/no; employed 15 (30.6%)/34 vs not employed 32 (49.2%)/33, P = 0.05) and achieved worse results in psychometric tests (RBANS sum score mean ± SD employed 472.1 ± 44.5 vs not employed 443.1 ± 56.7, P = 0.04) than those employed. Ten patients (18.2%), who were not employed before OLT, resumed work afterwards. The patients employed after OLT were younger [age median (range, min-max) employed 47 (42, 18-60) vs not employed 50 (31, 29-60), P = 0.01], achieved better results in the psychometric tests (RBANS sum score mean ± SD employed 490.7 ± 48.2 vs not employed 461.0 ± 54.5, P = 0.02) and had a higher health-related quality of life (SF 36 sum score mean ± SD employed 627.0 ± 138.1 vs not employed 433.7 ± 160.8; P < 0.001) compared to patients not

  15. Anatomic feature of deltoid ligament attachment in posteromedial osteochondral lesion of talar dome.

    PubMed

    Nakasa, Tomoyuki; Sawa, Mikiya; Ikuta, Yasunari; Yoshikawa, Masahiro; Tsuyuguchi, Yusuke; Adachi, Nobuo

    2018-03-01

    Osteochondral lesions of the talus (OLT) are recognized as being commonly associated with trauma. However, the etiology of OLT remains unclear. In the case of a posteromedial lesion of OLT (medial OLT), the deep layer of the deltoid ligament is located close to the medial OLT, and this relationship between a medial lesion and deltoid ligament could be a risk factor for medial OLT. The purpose of this study is to investigate the unique anatomic feature of the deep deltoid attachment to the talus in patients with medial OLT compared with patients with non-medial OLT. Forty ankles with medial OLT and 40 ankles without medial OLT were retrospectively reviewed in this study. On the coronal images of MRI, the attachment of deltoid ligament was measured. The continuity of the osteochondral fragment and its bed was evaluated on MRI and arthroscopic findings. Coronal MRI images showed that the attachment of the deep deltoid ligament to the medial OLT was broader and located more proximally than in non-medial OLT. The continuity of fibers from the insertion site of deltoid ligament to the talus to the osteochondral fragment was observed (76.7%). In the arthroscopic findings, the osteochondral fragment was obviously connected to the talus at the medial site in 85.2% of feet. The location of the deep deltoid ligament attachment to the medial OLT was more proximal and there was the possibility of these anatomic feature might contribute to the pathogenesis of medial OLT. Copyright © 2017 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

  16. Predictors of renal function recovery among patients undergoing renal replacement therapy following orthotopic liver transplantation.

    PubMed

    Andreoli, Maria Claudia Cruz; Souza, Nádia Karina Guimarães de; Ammirati, Adriano Luiz; Matsui, Thais Nemoto; Carneiro, Fabiana Dias; Ramos, Ana Claudia Mallet de Souza; Iizuca, Ilson Jorge; Coelho, Maria Paula Vilela; Afonso, Rogério Carballo; Ferraz-Neto, Ben-Hur; Almeida, Marcio Dias de; Durão, Marcelino; Batista, Marcelo Costa; Monte, Julio Cesar; Pereira, Virgílio Gonçalves; Santos, Oscar Pavão Dos; Santos, Bento Cardoso Dos

    2017-01-01

    Renal dysfunction frequently occurs during the periods preceding and following orthotopic liver transplantation (OLT), and in many cases, renal replacement therapy (RRT) is required. Information regarding the duration of RRT and the rate of kidney function recovery after OLT is crucial for transplant program management. We evaluated a sample of 155 stable patients undergoing post-intensive care hemodialysis (HD) from a patient population of 908 adults who underwent OLT. We investigated the average time to renal function recovery (duration of RRT required) and determined the risk factors for remaining on dialysis > 90 days after OLT. Log-rank tests were used for univariate analysis, and Cox proportional hazards models were used to identify factors associated with the risk of remaining on HD. The results of our analysis showed that of the 155 patients, 28% had pre-OLT diabetes mellitus, 21% had pre-OLT hypertension, and 40% had viral hepatitis. Among the patients, the median MELD (Model for End-Stage Liver Disease) score was 27 (interquartile range [IQR] 22-35). When they were listed for liver transplantation, 32% of the patients had serum creatinine (Scr) levels > 1.5 mg/dL or were on HD, and 50% had serum creatinine (Scr) levels > 1.5 mg/dL or were on HD at the time of OLT. Of the transplanted patients, 25% underwent pre-OLT intermittent HD, and 14% and 41% underwent continuous renal replacement therapy (CRRT) pre-OLT and post-OLT, respectively. At 90 days post-OLT, 118 (76%) patients had been taken off dialysis, and 16 (10%) patients had died while undergoing HD. The median recovery time of these post-OLT patients was 33 (IQR 27-39) days. In the multivariate analysis, fulminant hepatic failure as the cause of liver disease (p<0.001), the absence of pre-OLT hypertension (p = 0.016), a lower intraoperative fresh-frozen plasma (FFP) transfusion volume (p = 0.019) and not undergoing pre-OLT intermittent HD (p = 0.032) were associated with performing RRT for less than

  17. Predictors of renal function recovery among patients undergoing renal replacement therapy following orthotopic liver transplantation

    PubMed Central

    de Souza, Nádia Karina Guimarães; Ammirati, Adriano Luiz; Matsui, Thais Nemoto; Carneiro, Fabiana Dias; Ramos, Ana Claudia Mallet de Souza; Iizuca, Ilson Jorge; Afonso, Rogério Carballo; Ferraz-Neto, Ben-Hur; de Almeida, Marcio Dias; Durão, Marcelino; Batista, Marcelo Costa; Monte, Julio Cesar; Pereira, Virgílio Gonçalves; dos Santos, Oscar Pavão

    2017-01-01

    Renal dysfunction frequently occurs during the periods preceding and following orthotopic liver transplantation (OLT), and in many cases, renal replacement therapy (RRT) is required. Information regarding the duration of RRT and the rate of kidney function recovery after OLT is crucial for transplant program management. We evaluated a sample of 155 stable patients undergoing post-intensive care hemodialysis (HD) from a patient population of 908 adults who underwent OLT. We investigated the average time to renal function recovery (duration of RRT required) and determined the risk factors for remaining on dialysis > 90 days after OLT. Log-rank tests were used for univariate analysis, and Cox proportional hazards models were used to identify factors associated with the risk of remaining on HD. The results of our analysis showed that of the 155 patients, 28% had pre-OLT diabetes mellitus, 21% had pre-OLT hypertension, and 40% had viral hepatitis. Among the patients, the median MELD (Model for End-Stage Liver Disease) score was 27 (interquartile range [IQR] 22-35). When they were listed for liver transplantation, 32% of the patients had serum creatinine (Scr) levels > 1.5 mg/dL or were on HD, and 50% had serum creatinine (Scr) levels > 1.5 mg/dL or were on HD at the time of OLT. Of the transplanted patients, 25% underwent pre-OLT intermittent HD, and 14% and 41% underwent continuous renal replacement therapy (CRRT) pre-OLT and post-OLT, respectively. At 90 days post-OLT, 118 (76%) patients had been taken off dialysis, and 16 (10%) patients had died while undergoing HD. The median recovery time of these post-OLT patients was 33 (IQR 27–39) days. In the multivariate analysis, fulminant hepatic failure as the cause of liver disease (p<0.001), the absence of pre-OLT hypertension (p = 0.016), a lower intraoperative fresh-frozen plasma (FFP) transfusion volume (p = 0.019) and not undergoing pre-OLT intermittent HD (p = 0.032) were associated with performing RRT for less

  18. Persistent Hg contamination and occurrence of Hg-methylating transcript (hgcA) downstream of a chlor-alkali plant in the Olt River (Romania).

    PubMed

    Bravo, Andrea G; Loizeau, Jean-Luc; Dranguet, Perrine; Makri, Stamatina; Björn, Erik; Ungureanu, Viorel Gh; Slaveykova, Vera I; Cosio, Claudia

    2016-06-01

    Chlor-alkali plants using mercury (Hg) cell technology are acute point sources of Hg pollution in the aquatic environment. While there have been recent efforts to reduce the use of Hg cells, some of the emitted Hg can be transformed to neurotoxic methylmercury (MeHg). Here, we aimed (i) to study the dispersion of Hg in four reservoirs located downstream of a chlor-alkali plant along the Olt River (Romania) and (ii) to track the activity of bacterial functional genes involved in Hg methylation. Total Hg (THg) concentrations in water and sediments decreased successively from the initial reservoir to downstream reservoirs. Suspended fine size particles and seston appeared to be responsible for the transport of THg into downstream reservoirs, while macrophytes reflected the local bioavailability of Hg. The concentration and proportion of MeHg were correlated with THg, but were not correlated with bacterial activity in sediments, while the abundance of hgcA transcript correlated with organic matter and Cl(-) concentration, indicating the importance of Hg bioavailability in sediments for Hg methylation. Our data clearly highlights the importance of considering Hg contamination as a legacy pollutant since there is a high risk of continued Hg accumulation in food webs long after Hg-cell phase out.

  19. Distribution and landscape controls of organic layer thickness and carbon within the Alaskan Yukon River Basin

    USGS Publications Warehouse

    Pastick, Neal J.; Rigge, Matthew B.; Wylie, Bruce K.; Jorgenson, M. Torre; Rose, Joshua R.; Johnson, Kristofer D.; Ji, Lei

    2014-01-01

    Understanding of the organic layer thickness (OLT) and organic layer carbon (OLC) stocks in subarctic ecosystems is critical due to their importance in the global carbon cycle. Moreover, post-fire OLT provides an indicator of long-term successional trajectories and permafrost susceptibility to thaw. To these ends, we 1) mapped OLT and associated uncertainty at 30 m resolution in the Yukon River Basin (YRB), Alaska, employing decision tree models linking remotely sensed imagery with field and ancillary data, 2) converted OLT to OLC using a non-linear regression, 3) evaluate landscape controls on OLT and OLC, and 4) quantified the post-fire recovery of OLT and OLC. Areas of shallow (2 = 0.68; OLC: R2 = 0.66), where an average of 16 cm OLT and 5.3 kg/m2 OLC were consumed by fires. Strong predictors of OLT included climate, topography, near-surface permafrost distributions, soil wetness, and spectral information. Our modeling approach enabled us to produce regional maps of OLT and OLC, which will be useful in understanding risks and feedbacks associated with fires and climate feedbacks.

  20. Laparoscopic Sleeve Gastrectomy for Morbid Obesity in Patients After Orthotopic Liver Transplant: a Matched Case-Control Study.

    PubMed

    Tsamalaidze, Levan; Stauffer, John A; Arasi, Lisa C; Villacreses, Diego E; Franco, Jose Salvador Serrano; Bowers, Steven; Elli, Enrique F

    2018-02-01

    Obesity is frequently encountered in patients with orthotopic liver transplant (OLT). The role of bariatric surgery is still unclear for this specific population. The aim of this study was to review our experience with laparoscopic sleeve gastrectomy (LSG) after OLT. We performed a retrospective case-control study of patients undergoing LSG after OLT from 2010 to 2016. OLT-LSG patients were matched by age, sex, body mass index (BMI), and year to non-OLT patients undergoing LSG. Demographics, operative variables, postoperative events, and long-term weight loss with comorbidity resolution were collected and compared between cases and controls. Of 303 patients undergoing LSG, 12 (4%) had previous OLT. They were matched to 36 non-OLT patients. No difference was found between groups in the American Society of Anesthesiologists class, mean operative time, or postoperative morbidity. The non-OLT group, however, had a significantly shorter mean hospital stay than the OLT group (1.7 vs 3.1 days; P < .001). There were no conversions to open procedures. For patients with long-term follow-up, change in BMI after LSG was similar between the groups, but the non-OLT patients had significantly more excess body weight loss at 2 years (53.7 vs 45.2%; P < .001). Similar resolution of comorbid conditions was noted in both groups. LSG caused no changes in dosage of immunosuppressive medications, and no liver complications occurred. LSG after OLT in appropriately selected patients appears to have similar outcomes to LSG in non-OLT patients.

  1. High-resolution airborne gravity imaging over James Ross Island (West Antarctica)

    USGS Publications Warehouse

    Jordan, T.A.; Ferraccioli, F.; Jones, P.C.; Smellie, J.L.; Ghidella, M.; Corr, H. F. J.; Zakrajsek, A.F.

    2007-01-01

    James Ross Island (JRI) exposes a Miocene-Recent alkaline basaltic volcanic complex that developed in a back-arc, east of the northern Antarctic Peninsula. JRI has been the focus of several geological studies because it provides a window on Neogene magmatic processes and paleoenvironments. However, little is known about its internal structure. New airborne gravity data were collected as part of the first high-resolution aerogeophysical survey flown over the island and reveal a prominent negative Bouguer gravity anomaly over Mt Haddington. This is intriguing as basaltic volcanoes are typically associated with positive Bouguer anomalies, linked to underlying mafic intrusions. The negative Bouguer anomaly may be associated with a hitherto unrecognised low-density sub-surface body, such as a breccia-filled caldera, or a partially molten magma chamber.

  2. Societal reintegration following cadaveric orthotopic liver transplantation.

    PubMed

    Kelly, Ryan; Hurton, Scott; Ayloo, Subhashini; Cwinn, Mathew; De Coutere-Bosse, Sarah; Molinari, Michele

    2016-06-01

    Studies on patients' societal reintegration following orthotopic liver transplantation (OLT) are scarce. Between September 2006 and January 2008, all adults who were alive after 3 years post OLT were included in this prospective cohort study. Validated questionnaires were administered to all candidates with the primary aim of investigating the rate of their social re-integration following OLT and potential barriers they might have encountered. Among 157 eligible patients 110 (70%) participated. Mean participants' age was 57 years (SD 11.4) and 43% were females. Prior to OLT, 75% of patients were married and 6% were divorced. Following OLT there was no significant difference in marital status. Employment rate fell from 72% to 30% post-OLT. Patients who had been employed in either low-skill or advanced-skill jobs were less likely to return to work. After OLT, personal income fell an average of 4,363 Canadian dollars (CAN$) (SD 20,733) (P=0.03) but the majority of recipients (80%) reported high levels of satisfaction for their role in society. Although patients' satisfaction post-OLT is high, employment status is likely to be negatively affected for individuals who are not self-employed. Strategies to assist recipients in returning to their pre-OLT jobs should be developed to improve patients' economical status and societal ability to recoup resources committed for OLT.

  3. Evaluation of joint position sense measured by inversion angle replication error in patients with an osteochondral lesion of the talus.

    PubMed

    Nakasa, Tomoyuki; Adachi, Nobuo; Shibuya, Hayatoshi; Okuhara, Atsushi; Ochi, Mitsuo

    2013-01-01

    The etiology of the osteochondral lesion of the talar dome (OLT) remains unclear. A joint position sense deficit of the ankle is reported to be a possible cause of ankle disorder. Repeated contact of the articular surface of the talar dome with the plafond during inversion might be a cause of OLT. The aim of the present study was to evaluate the joint position sense deficit by measuring the replication error of the inversion angle in patients with OLT. The replication error, which is the difference between the index angle and replication angle in inversion, was measured in 15 patients with OLT. The replication error in 15 healthy volunteers was evaluated as a control group. The side to side differences of the replication errors between the patients with OLT and healthy volunteers and the replication errors in each angle between the involved and uninvolved ankle in the patients with OLT were investigated. Finally, the side to side differences of the replication errors between the patients with OLT with a traumatic and nontraumatic history were compared. The side to side difference in the patients with OLT (1.3° ± 0.2°) was significantly greater than that in the healthy subjects (0.4° ± 0.7°) (p ≤ .05). Significant differences were found between the involved and uninvolved sides at 10°, 15°, 20°, and 25° in the patients with OLT. No significant difference (p > .05) was found between the patients with traumatic and nontraumatic OLT. The present study found that the patients with OLT have a joint position sense deficit during inversion movement, regardless of a traumatic history. Although various factors for the etiology of OLT have been reported, the joint position sense deficit in inversion might be a cause of OLT. Copyright © 2013 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  4. Exposing Clinicians to Exposure: A Randomized Controlled Dissemination Trial of Exposure Therapy for Anxiety Disorders

    PubMed Central

    Harned, Melanie S.; Dimeff, Linda A.; Woodcock, Eric A.; Kelly, Tim; Zavertnik, Jake; Contreras, Ignacio; Danner, Sankirtana M.

    2014-01-01

    Objective The present study evaluated three technology-based methods of training mental health providers in exposure therapy (ET) for anxiety disorders. Training methods were designed to address common barriers to the dissemination of ET, including limited access to training, negative clinician attitudes toward ET, and lack of support during and following training. Method Clinicians naïve to ET (N=181, Mage = 37.4, 71.3% female, 72.1% Caucasian) were randomly assigned to: 1) an interactive, multimedia online training (OLT), 2) OLT plus a brief, computerized motivational enhancement intervention (OLT+ME), or 3) OLT + ME plus a web-based learning community (OLT+ME+LC). Assessments were completed at baseline, post-training, and 6 and 12 weeks following training. Outcomes include satisfaction, knowledge, self-efficacy, attitudes, self-reported clinical use, and observer-rated clinical proficiency. Results All three training methods led to large and comparable improvements in self-efficacy and clinical use of ET, indicating that OLT alone was sufficient for improving these outcomes. The addition of the ME intervention did not significantly improve outcomes in comparison to OLT alone. Supplementing the OLT with both the ME intervention and the LC significantly improved attitudes and clinical proficiency in comparison to OLT alone. The OLT+ME+LC condition was superior to both other conditions in increasing knowledge of ET. Conclusions Multi-component trainings that address multiple potential barriers to dissemination appear to be most effective in improving clinician outcomes. Technology-based training methods offer a satisfactory, effective, and scalable way to train mental health providers in evidence-based treatments such as ET. PMID:25311284

  5. Factors influencing long-term quality of life and depression in German liver transplant recipients: a single-centre cross-sectional study.

    PubMed

    Zahn, Alexandra; Seubert, Lisa; Jünger, Jana; Schellberg, Dieter; Weiss, Karl Heinz; Schemmer, Peter; Stremmel, Wolfgang; Sauer, Peter; Gotthardt, Daniel Nils

    2013-06-26

    Health-related quality of life (HRQOL) following orthotopic liver transplantation (OLT) has become increasingly important. Therefore, we aimed to identify factors affecting HRQOL after OLT. This cross-sectional, single-centre study surveyed 281 OLT patients. Survey tools included the Short Form (SF-36) Health Survey, the Patient Health Questionnaire 9 (PHQ9), and a self-designed employment questionnaire. Patient medical records were reviewed. Participants included 187 men (mean age at OLT: 50 [± 11; 13-69] years). Primary indications for OLT were viral hepatitis (28%), alcoholic liver disease (35%), cholestatic liver disease (11%), and others (26%). Follow-up ranged from 2 to 136 months. Clinical factors associated with improved HRQOL were age ≤ 45 years at OLT and current MELD score <=≤ 13. Time after OLT and indication for transplantation affected SF-36 HRQOL. SF-36 physical component summary scales plateaued at 3-years post-OLT and then stabilized. For the SF-36 HRQOL, scores were the lowest in all domains for OLT recipients transplanted for chronic viral hepatitis and for unemployed patients, whereas sex and number of transplantations showed no significant differences. The PHQ9 results showed that depression was significantly more frequent among patients with current MELD score ≥ 13 or impaired liver function and those transplanted for chronic viral hepatitis or unemployed patients. Age and sex did not influence PHQ9 results. Medical and psychosocial support is crucial for long-term HRQOL after OLT. Developing multidisciplinary interventions to address issues such as employment, age, MELD score, and liver function may improve long-term HRQOL in these patients.

  6. The Effect of Bridging Locoregional Therapy and Sociodemographics on Survival in Hepatocellular Carcinoma Patients Undergoing Orthotopic Liver Transplantation: A United Network for Organ Sharing Population Study.

    PubMed

    Magnetta, Michael J; Xing, Minzhi; Zhang, Di; Kim, Hyun S

    2016-12-01

    To investigate socioeconomic and demographic factors associated with transplantation outcomes in patients with hepatocellular carcinoma (HCC) treated with bridging locoregional therapy (LRT) before orthotopic liver transplantation (OLT). The United Network for Organ Sharing (UNOS) database was used to identify all patients in the United States with HCC who were listed for OLT between 2002 and 2013. Mean overall survival (OS) after OLT was stratified based on age, sex, ethnicity, transplant year, region, and insurance status. Kaplan-Meier estimation was used for survival analysis with log-rank test and Cox proportional hazards model to assess independent prognostic factors for OS. Of the 17,291 listed patients with HCC, 14,511 underwent OLT. Mean age was 57.4 years (76.8% male). Favorable sociodemographic factors were associated with increased rates of bridging LRT before OLT and longer wait time on the transplant list and were shown to be independent prognostic factors for prolonged OS after OLT using multivariate analysis. Favorable demographic factors included patient age < 60 years, donor age < 45 years, year of diagnosis between 2008 and 2013, UNOS regions 4 and 5, Asian ethnicity, high functional status, postgraduate education, private payer insurance, and employment at the time of OLT. Patients with favorable sociodemographics had higher rates of LRT before OLT performed for HCC cure. These patients had longer transplant wait times and longer OS after OLT. Copyright © 2016 SIR. Published by Elsevier Inc. All rights reserved.

  7. Seasonal Water Transport in the Atmosphere of Mars: Applications of a Mars General Circulation Model Using Mars Global Surveyor Data

    NASA Technical Reports Server (NTRS)

    Hollingsworth, Jeffery L.; Bridger, Alison F. C.; Haberle, Robert M.

    1999-01-01

    This is a Final Report for a Joint Research Interchange (JRI) between NASA Ames Research Center and San Jose State University, Department of Meteorology. We present below a summary of progress made during the duration of this JRI. The focus of this JRI has been to investigate seasonal water vapor transport in the atmosphere of Mars and its effects on the planet's present climate. To this end, the primary task has been to adapt a new dynamical processor for the adiabatic tendencies of the atmospheric circulation into the NASA Ames Mars general circulation model (MGCM). Using identical boundary and initial conditions, several comparative tests between the new and old MGCMs have been performed and the nature of the simulated circulations have been diagnosed. With confidence that the updated version of the Ames MGCM produces quite similar mean and eddy circulation statistics, the new climate model is well poised as a tool to pursue fundamental questions related to the spatial and seasonal variations of atmospheric water vapor on Mars, and to explore exchanges of water with non-atmospheric reservoirs and transport within its atmosphere. In particular, the role of surface sources and sinks can be explored, the range of water-vapor saturation altitudes can be investigated, and plausible precipitation mechanisms can be studied, for a range of atmospheric dust loadings. Such future investigations can contribute to a comprehensive study of surface inventories, exchange mechanisms, and the relative importance of atmospheric transport Mars' water cycle. A listing of presentations made and manuscripts submitted during the course of this project is provided.

  8. Seasonal Water Transport in the Atmosphere of Mars: Applications of a Mars General Circulation Model Using Mars Global Surveyor Data

    NASA Technical Reports Server (NTRS)

    Hollingsworth, Jeffery L.; Bridger, Alison F. C.; Haberle, Robert M.

    1999-01-01

    This is a Final Report for a Joint Research Interchange (JRI) between NASA Ames Research Center and San Jose State University, Department of Meteorology. We present below a summary of progress made during the duration of this JRI. The focus of this JRI has been to investigate seasonal water vapor transport in the atmosphere of Mars and its effects on the planet's present climate. To this end, the primary task has been to adapt a new dynamical processor for the adiabatic tendencies of the atmospheric circulation into the NASA Ames Mars general circulation model (MGCM). Using identical boundary and initial conditions, several comparative tests between the new and old MGCMs have been performed and the nature of the simulated circulations have been diagnosed. With confidence that the updated version of the Ames MGCM produces quite similar mean and eddy circulation statistics, the new climate model is well poised as a tool to pursue fundamental questions related to the spatial and seasonal variations of atmospheric water vapor on Mars, and to explore exchanges of water with non-atmospheric reservoirs and transport within its atmosphere. In particular, the role of surface sources and sinks can be explored, the range of water-vapor saturation altitudes can be investigated, and plausible precipitation mechanisms can be studied, for a range of atmospheric dust loadings, such future investigations can contribute to a comprehensive study of surface inventories, exchange mechanisms, and the relative importance of atmospheric transport Mars' water cycle. A listing of presentations made and manuscripts submitted during the course of this project is provided.

  9. Presence of intrahepatic (total and ccc) HBV DNA is not predictive of HBV recurrence after liver transplantation.

    PubMed

    Hussain, Munira; Soldevila-Pico, Consuelo; Emre, Sukru; Luketic, Velimir; Lok, Anna S F

    2007-08-01

    Previous studies reported that hepatitis B virus (HBV) deoxyribonucleic acid (DNA) can be detected in livers of patients who received transplants for hepatitis B despite the absence of serological markers of HBV recurrence. Quantification of HBV DNA was not performed and presence of covalently closed circular (ccc) DNA was not analyzed in most studies. We aimed to quantify total and ccc HBV DNA in explant liver and post-orthotopic liver transplantation (OLT) biopsies and to correlate the values with HBV recurrence post-OLT. Frozen liver tissue from 34 patients (9 with explant liver only, 9 with explant liver and post-OLT liver biopsies, and 16 with post-OLT biopsies only) in the National Institutes of Health HBV-OLT study was examined using real-time polymerase chain reaction (PCR). Among the 18 patients with explant liver, 7 were hepatitis B e antigen (HBeAg)-positive, 8 had detectable serum HBV DNA, and 10 received antiviral therapy prior to OLT. Total and ccc HBV DNA was detected in explant livers of 17 and 16 patients, respectively. Of the 10 patients who received antiviral therapy pre-OLT, serum HBV DNA was undetectable in 8 at transplantation but 7 had detectable total and ccc HBV DNA in their explant liver. Of the 25 patients with post-OLT biopsies, total HBV DNA was detected in 83% and ccc DNA in 17% of 47 biopsies, although only 2 patients had HBV recurrence. In conclusion, total and ccc HBV DNA could be detected in explant livers of most patients despite antiviral therapy pre-OLT. Total but not ccc HBV DNA could be detected in post-OLT liver biopsies of most patients despite undetectable serum HBV DNA and hepatitis B surface antigen (HBsAg). Our findings suggest that occult HBV reinfection occurs in most HBV patients after OLT and continued administration of appropriate prophylactic therapy is important in preventing overt HBV recurrence. Copyright (c) 2007 AASLD.

  10. Permafrost and organic layer interactions over a climate gradient in a discontinuous permafrost zone

    NASA Astrophysics Data System (ADS)

    Johnson, Kristofer D.; Harden, Jennifer W.; McGuire, A. David; Clark, Mark; Yuan, Fengming; Finley, Andrew O.

    2013-09-01

    Permafrost is tightly coupled to the organic soil layer, an interaction that mediates permafrost degradation in response to regional warming. We analyzed changes in permafrost occurrence and organic layer thickness (OLT) using more than 3000 soil pedons across a mean annual temperature (MAT) gradient. Cause and effect relationships between permafrost probability (PF), OLT, and other topographic factors were investigated using structural equation modeling in a multi-group analysis. Groups were defined by slope, soil texture type, and shallow (<28 cm) versus deep organic (≥28 cm) layers. The probability of observing permafrost sharply increased by 0.32 for every 10-cm OLT increase in shallow OLT soils (OLTs) due to an insulation effect, but PF decreased in deep OLT soils (OLTd) by 0.06 for every 10-cm increase. Across the MAT gradient, PF in sandy soils varied little, but PF in loamy and silty soils decreased substantially from cooler to warmer temperatures. The change in OLT was more heterogeneous across soil texture types—in some there was no change while in others OLTs soils thinned and/or OLTd soils thickened at warmer locations. Furthermore, when soil organic carbon was estimated using a relationship with thickness, the average increase in carbon in OLTd soils was almost four times greater compared to the average decrease in carbon in OLTs soils across all soil types. If soils follow a trajectory of warming that mimics the spatial gradients found today, then heterogeneities of permafrost degradation and organic layer thinning and thickening should be considered in the regional carbon balance.

  11. Permafrost and organic layer interactions over a climate gradient in a discontinuous permafrost zone

    USGS Publications Warehouse

    Johnson, Kristofer D.; Harden, Jennifer W.; McGuire, A. David; Clark, Mark; Yuan, Fengming; Finley, Andrew O.

    2013-01-01

    Permafrost is tightly coupled to the organic soil layer, an interaction that mediates permafrost degradation in response to regional warming. We analyzed changes in permafrost occurrence and organic layer thickness (OLT) using more than 3000 soil pedons across a mean annual temperature (MAT) gradient. Cause and effect relationships between permafrost probability (PF), OLT, and other topographic factors were investigated using structural equation modeling in a multi-group analysis. Groups were defined by slope, soil texture type, and shallow (<28 cm) versus deep organic (≥28 cm) layers. The probability of observing permafrost sharply increased by 0.32 for every 10-cm OLT increase in shallow OLT soils (OLTs) due to an insulation effect, but PF decreased in deep OLT soils (OLTd) by 0.06 for every 10-cm increase. Across the MAT gradient, PF in sandy soils varied little, but PF in loamy and silty soils decreased substantially from cooler to warmer temperatures. The change in OLT was more heterogeneous across soil texture types—in some there was no change while in others OLTs soils thinned and/or OLTd soils thickened at warmer locations. Furthermore, when soil organic carbon was estimated using a relationship with thickness, the average increase in carbon in OLTd soils was almost four times greater compared to the average decrease in carbon in OLTs soils across all soil types. If soils follow a trajectory of warming that mimics the spatial gradients found today, then heterogeneities of permafrost degradation and organic layer thinning and thickening should be considered in the regional carbon balance.

  12. Pretreatment of liver grafts in vivo by γ-aminobutyric acid receptor regulation reduces cold ischemia/warm reperfusion injury in rat

    PubMed Central

    Hori, Tomohide; Gardner, Lindsay B.; Hata, Toshiyuki; Chen, Feng; Baine, Ann-Marie T.; Uemoto, Shinji; Nguyen, Justin H.

    2014-01-01

    Summary Background: Gamma-aminobutyric acid (GABA) is found throughout the body. The regulation of GABA receptor (GABAR) reduces oxidative stress (OS). Ischemia/reperfusion injury after orthotopic liver transplantation (OLT) causes OS-induced graft damage. The effects of GABAR regulation in donors in vivo were investigated. Material/Methods: Donor rats received saline, a GABAR agonist or GABAR antagonist 4 h before surgery. Recipient rats were divided into four groups according to the donor treatments: laparotomy, OLT with saline, OLT with GABAR agonist and OLT with GABAR antagonist. Histopathological, biochemical and immunohistological examinations were performed at 6, 12 and 24 h after OLT. Protein assays were performed at 6 h after OLT. The 4-hydroxynonenal (4-HNE), ataxia-telangiectasia mutated kinase (ATM), phosphorylated histone H2AX (γH2AX), phosphatidylinositol-3 kinase (PI3K), Akt and superoxide dismutase (SOD) were assessed by western blot analysis. Results: In the univariate analysis, histopathological and biochemical profiles verified that the GABAR agonist reduced graft damage. Immunohistology revealed that the GABAR agonist prevented the induction of apoptosis. Measurement of 4-4-HNE levels confirmed OS-induced damage after OLT, and the GABAR agonist improved this damage. In the γH2AX, PI3K, Akt and antioxidant enzymes (SODs), ATM and H2AX were greatly increased after OLT, and were reduced by the GABAR agonist. In the multivariate analyses between multiple groups, histopathological assessment, aspartate aminotransferase level, immunohistological examinations for apoptotic induction and γH2AX showed statistical differences. Conclusions: A specific agonist demonstrated regulation of GABAR in vivo in the liver. This activation in vivo reduced OS after OLT via the ATM/H2AX pathway. PMID:23792534

  13. Change in hepatic function, hemodynamics, and morphology after liver transplant. Physiological effect of therapy.

    PubMed

    Millikan, W J; Henderson, J M; Stewart, M T; Warren, W D; Marsh, J W; Galloway, J R; Jennings, H; Kawasaki, S; Dodson, T F; Perlino, C A

    1989-05-01

    Orthotopic liver transplantation (OLT) has become standard therapy for patients with acute hepatic necrosis and end-stage liver disease. This study measured change in hepatic function (galactose elimination capacity [GEC]), liver blood flow (low dose galactose clearance: flow), hepatic volume (CT scan; volume) and morphology after OLT. The aim was to measure the physiologic response after OLT and compare this response with that after selective shunt (SS) and sclerotherapy (ES) to determine which patients should receive specific therapy. Between January 1987 and November 1988, 37 patients underwent OLT. Operative mortality was 18%, which was similar to that of SS in Child's C cirrhotics. GEC and volume were less in transplant patients than in cirrhotics treated with SS or ES. GEC, flow, and volume normalized after OLT; GEC was preserved after ES and SS, but volume decreased. Three preoperative patterns were observed that can aid in selection of OLT candidates. Patients with chronic cirrhosis (chronic active hepatitis; cryptogenic) need OLT when GEC is less than or equal to 225 mg/min and volume is less than or equal to 50% normal. Patients with Budd-Chiari Syndrome require OLT if cirrhosis has evolved. Patients with sclerosing cholangitis and primary biliary cirrhosis qualify for transplants when complications of the portal hypertensive syndrome develop. The studies can also direct therapy for ES failures. Selective shunt is indicated in those patients with stable disease whose GEC is greater than or equal to 300 mg/min and liver volume is greater than 75% normal; OLT is indicated for cirrhotics with GEC that is less than 225 mg/min and liver volume that is less than 50% predicted normal.

  14. Cardiovascular risk after orthotopic liver transplantation, a review of the literature and preliminary results of a prospective study.

    PubMed

    Pisano, Giuseppina; Fracanzani, Anna L; Caccamo, Lucio; Donato, Maria F; Fargion, Silvia

    2016-10-28

    Improved surgical techniques and greater efficacy of new anti-rejection drugs have significantly improved the survival of patients undergoing orthotopic liver transplantation (OLT). This has led to an increased incidence of metabolic disorders as well as cardiovascular and cerebrovascular diseases as causes of morbidity and mortality in OLT patients. In the last decade, several studies have examined which predisposing factors lead to increased cardiovascular risk ( i.e ., age, ethnicity, diabetes, NASH, atrial fibrillation, and some echocardiographic parameters) as well as which factors after OLT ( i.e ., weight gain, metabolic syndrome, immunosuppressive therapy, and renal failure) are linked to increased cardiovascular mortality. However, currently, there are no available data that evaluate the development of atherosclerotic damage after OLT. The awareness of high cardiovascular risk after OLT has not only lead to the definition of new but generally not accepted screening of high risk patients before transplantation, but also to the need for careful patient follow up and treatment to control metabolic and cardiovascular pathologies after transplant. Prospective studies are needed to better define the predisposing factors for recurrence and de novo occurrence of metabolic alterations responsible for cardiovascular damage after OLT. Moreover, such studies will help to identify the timing of disease progression and damage, which in turn may help to prevent morbidity and mortality for cardiovascular diseases. Our preliminary results show early occurrence of atherosclerotic damage, which is already present a few weeks following OLT, suggesting that specific, patient-tailored therapies should be started immediately post OLT.

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

    Maleux, Geert; Pirenne, Jacques; Vaninbroukx, Johan

    Our purpose was to assess the feasibility of orthotopic liver transplantation (OLT) in patients priorly having undergone transjugular intrahepatic portosystemic shunt (TIPS) with an expanded tetrafluoroethylene (e-PTFE)-covered endoprosthesis. In 48 patients an e- PTFE-covered endoprosthesis was inserted to treat severe complications of portal hypertension. In 36 patients the endoprosthesis was inserted during TIPS creation (de novo TIPS); in the other 12 patients the endoprosthesis was placed to repermeabilize the previously created, but occluded bare stent (revision TIPS). Eight of them (5 de novo and 3 revision cases) later underwent an OLT. The hospital records of these patients were reviewed frommore » initial admission, through TIPS, the pre-OLT period, and OLT to current postoperative status. Five de novo and 3 revision cases underwent OLT 4-279 days (mean delay: 80.8 days) after TIPS procedure. All OLT's were performed under veno-venous bypass surgery. De visu surgical inspection confirmed correct positioning of the fully patent stent graft, starting in the portal vein and ending at the junction of the hepatic vein to the inferior caval vein. No surgical difficulty was observed during proximal or distal clamping or during resection of the diseased liver. Correctly positioned e-PTFE-covered nitinol endoprostheses do not interfere with a later OLT and may not be considered as a contraindication in patients who need a TIPS as a bridge to OLT.« less

  16. Effects of an early referral system on liver transplantation for hepatoblastoma at Texas Children's Hospital.

    PubMed

    Kueht, Michael; Thompson, Patrick; Rana, Abbas; Cotton, Ronald; O'Mahony, Christine; Goss, John

    2016-06-01

    The purposes of this study were to analyze the effects of an ERS on time to transplantation and to describe our center's experience with OLT for HB. Patients who received OLT for HB between 2000 and 2013 were included. Patient and allograft characteristics, chemotherapy regimens, and prior surgical therapies were examined. The interval between diagnosis and OLT prior to and following the institution of an ERS for transplant was compared. Survival and tumor recurrence were analyzed. Nineteen patients received OLT for HB (mean age 33 months). All children received grafts from deceased donors. Two patients underwent prior resections. Tumor recurred in four patients (21.1%). Both patients who received salvage transplants experienced post-OLT recurrence. Three of the four recurrences occurred in spite of adjuvant chemotherapy. There were three deaths: two from metastatic disease. One- and five-yr survivals were 86.1% and 73.8%. After the institution of the ERS, the mean interval between tissue diagnosis and OLT was significantly reduced. Our series of 19 patients demonstrates a 21% recurrence of HB following OLT despite chemotherapy. Five-yr survival reached 73.8%. A system of early referral can effectively reduce times between diagnosis and transplant. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Differences in health-related quality of life scores after orthotopic liver transplantation with respect to selected socioeconomic factors.

    PubMed

    Saab, Sammy; Bownik, Hillary; Ayoub, Noel; Younossi, Zobair; Durazo, Francisco; Han, Steven; Hong, Johnny C; Farmer, Douglas; Busuttil, Ronald W

    2011-05-01

    One of the current ultimate goals of orthotopic liver transplantation (OLT) is the improvement of patients' health-related quality of life (HRQOL). The purpose of this study was to look at the effects of socioeconomic and demographic differences on the short-term and long-term HRQOL outcomes of OLT recipients. Three hundred three adult OLT recipients who were seen at the University of California Los Angeles were administered the Medical Outcomes Study Short Form 36 (SF-36), the Chronic Liver Disease Questionnaire (CLDQ), and a demographic survey. A parsimonious model of 12 socioeconomic and demographic predictors was identified. Their simultaneous influence on each SF-36 and CLDQ HRQOL domain score was evaluated with multivariate linear regression and backward selection. Hepatitis C virus impaired HRQOL; this was shown in the SF-36 Vitality and Bodily Pain domains and in most CLDQ domains. Females experienced more HRQOL impairment only within the CLDQ Abdominal Symptoms domain. OLT recipients who were married had better SF-36 Role-Emotion domain scores. OLT recipients with more than 12 years of education had better SF-36 Physical Functioning scores. Employed OLT recipients had less HRQOL impairment; this was evidenced by better scores in multiple domains of the SF-36 and the CLDQ. OLT patients with health maintenance organization or preferred provider organization insurance had higher HRQOL scores within almost all SF-36 and CLDQ domains. Patients with a mix of public and private insurance had significantly higher HRQOL scores in comparison with those with only public insurance. Identifying patients at higher risk for worse HRQOL scores, less satisfaction with OLT results, and greater problems with fatigue or mental health stressors will assist transplant centers in using their medical teams to develop early interventions and multidisciplinary approaches to improve HRQOL outcomes after OLT. Copyright © 2011 American Association for the Study of Liver Diseases.

  18. New Learning Technologies and Media in Quebec: Profile and Positioning of the Main Stakeholders = Portrait et positionnement des intervenants en nouvelles technologies et nouveaux medias d'apprentissage au Quebec.

    ERIC Educational Resources Information Center

    Human Resources Development Canada, Hull (Quebec). Office of Learning Technologies.

    This document is the product of a study that was conducted to identify the target audience of Canada's Office of Learning Technologies (OLT), determine which stakeholders should be involved in developing the OLT's action program; and recommend specific actions for the OLT to take. Chapter 1 provides an overview of the study methodology, which…

  19. Out-of-Level Testing for Special Education Students with Mild Learning Handicaps.

    ERIC Educational Resources Information Center

    Jones, Eric D.; And Others

    The purpose of this study was to evaluate the utility of out-of-level testing (OLT) when it is applied to the assessment of special education students with mild learning handicaps. This evaluation of OLT involved testing hypotheses related to: (1) the adequacy of vertical scaling, (2) the reliability and (3) the validity of OLT scores. Fifty-eight…

  20. Improving the Performance of Online Learning Teams--A Discourse Analysis

    ERIC Educational Resources Information Center

    Liu, Ying Chieh; Burn, Janice M.

    2007-01-01

    This paper compares the processes of Face-To-Face (FTF) teams and Online Learning Teams (OLTs) and proposes methods to improve the performance of OLTs. An empirical study reviewed the performance of fifteen FTF teams and OLTs and their communication patterns were coded by the TEMPO system developed by Futoran et al. (1989) in order to develop a…

  1. Circulating FoxP3+ Regulatory T and Interleukin17-Producing Th17 Cells Actively Influence HBV Clearance in De Novo Hepatitis B Virus Infected Patients after Orthotopic Liver Transplantation

    PubMed Central

    Li, Jin; Yang, Mei; Liu, Yuan; Guo, Xiaodong; Li, Hanwei; Liu, Zhenwen; Zhao, Jingmin

    2015-01-01

    Objective To longitudinally investigate the role of FoxP3+ Regulatory T cells (Treg) and interleukin17-producing T helper 17 cells (Th17) in De Novo Hepatitis B Virus infection after orthotopic Liver Transplantation (DNHB-OLT), and analyze the possible correlation between these cells and HBV clearance of the disease. Methods We enrolled 12 control cases after orthotopic Liver Transplantation (OLT) and 24 patients, including 12 diagnosed with DNHB-OLT and 12 diagnosed with Acute Hepatitis B Virus infection (AHB), into the study from the liver transplantation and research center at Beijing 302 Hospital. Flow cytometry was used to detect the frequencies of Treg and Th17, and ELISA was applied to detect the concentration of IL6, IL22, TGF-β and IL2 in peripheral blood. We also measured the gene expression level by real time-quantitative PCR and protein expression using immunohistochemistry and western-blot. Furthermore, we divided DNHB-OLT patients into the clearance and non-clearance groups and examined longitudinally Th17, Treg cells at different times. Results The percentage of Treg cells, expression of FoxP3 mRNA and related anti-inflammatory cytokines such as IL2 and TGF-β1 in the DNHB-OLT group were significantly higher than that in the AHB and OLT groups. The percentage of Th17 cells, expression of RORγt mRNA and related pro-inflammatory cytokines such as IL17 and IL22 in the DNHB-OLT group were significantly lower than that in the AHB group, but the levels of these cytokines are very similar to the OLT group. The ratios of Treg to Th17 in the DNHB-OLT group were significantly higher than that in the OLT and AHB groups. Treg frequencies significantly correlated with HBV DNA, whereas IL17 frequencies didn’t significantly correlate with ALT. In DNHB-OLT patients, the clearance group was accompanied by a rapid increase in the Th17 cells during the first 4th week and afterwards continuously decrease to the control group, together with a continuously decrease in

  2. Seven big strike-slip earthquakes

    NASA Astrophysics Data System (ADS)

    Lohman, R. B.; Simons, M.; Pritchard, M. E.

    2003-12-01

    We examine seven large (Mw > 7) strike-slip earthquakes that occurred since the beginning of ERS 1 and 2 missions. We invert GPS observations and InSAR interferograms and azimuth offsets for coseismic slip distributions. We explore two refinements to the traditional least-squares inversion technique with roughness constraints. First, we diverge from the usual definition of ``roughness'' as the average roughness over the entire fault plane, and allow ``variable smoothing'' constraints. Variable smoothing allows our inversion to select models that are more complex in regions that are well-resolved by the data, while still damping regions that are poorly resolved. Second, we choose our smoothing parameters using the jR_i criterion. The jR_i criterion draws on the theory behind cross-validation and the bootstrap method. We examine the theoretical basis behind such methods and use an analytical approximation technique for linear problems. We provide maps of model variance and spatial averaging scale over the fault plane, to explicitly show which features in our slip models are robust. We examine the 1992 Landers (CA), 1995 Sakhalin (Russia), 1995 Kobe (Japan), 1997 Ardekul (Iran), 1997 Manyi (Tibet), 1999 Hector Mine (CA), and 2001 Kunlun (Tibet) earthquakes. We compare features of the slip distributions such as the depth distribution of slip, the inferred magnitude and the degree of heterogeneity of slip over the fault plane, as resolved by the available InSAR and GPS data. We end with a brief description of the data coverage required for future earthquakes of similar size if we want to infer some of the above quantities to within a given confidence interval. We describe both the number of InSAR scenes and the distribution of GPS points that would be required, based on theoretical treatments of the fault plane/data point geometry using the jR_i method.

  3. Insights into accumulation variability over the last 2000 years at James Ross Island, Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Massam, A.; Mulvaney, R.; McConnell, J.; Abram, N.; Arienzo, M. M.; Whitehouse, P. L.

    2016-12-01

    The James Ross Island ice core, drilled to 364 m on the northern tip of the Antarctic Peninsula, preserves a climate record that spans beyond the Holocene period to the end of the last glacial maximum (LGM). Reanalysis of the ice core using high-resolution continuous flow analysis (CFA) highlighted errors in the identification of events of known age that had been used to constrain the earlier chronology. The new JRI2 chronology is annual layer counted to 300 years, with the remaining profile reconstructed using a new age-depth model that is tied to age horizons identified in the annual-layer counted WAIS Divide ice core record. An accurate age-depth profile requires reliable known-age horizons along the ice core profile. In addition, these allow us to determine a solution for the accumulation history and rate of compaction due to vertical strain. The accuracy of the known-age constraints used in JRI2 allows only a small uncertainty in the reconstruction of the most recent 2000 years of accumulation variability. Independently, the surface temperature profile has been estimated from the stable water isotope profile and calibrated to borehole temperature observations. We present the accumulation, vertical thinning and temperature history interpreted from the James Ross Island ice core for the most recent 2000 years. JRI2 reconstructions show accumulation variability on a decadal to centennial timescale up to 20% from the present-day mean annual accumulation rate of 0.63 m yr-1. Analysis of the accumulation profile for James Ross Island offers insight into the sensitivity of accumulation to a change in surface temperature, as well as the reliability of the assumed relationship between accumulation and surface temperature in climate reconstructions using stable water isotope proxies.

  4. Multicenter Study of Staging and Therapeutic Predictors of Hepatocellular Carcinoma Recurrence following Transplantation.

    PubMed

    Welling, Theodore H; Eddinger, Kevin; Carrier, Kristen; Zhu, Danting; Kleaveland, Tyler; Moore, Derek E; Schaubel, Douglas E; Abt, Peter L

    2018-05-05

    Orthotopic liver transplantation (OLT) and resection are effective treatments for hepatocellular carcinoma (HCC). However, optimizing OLT and limiting HCC recurrence remains a vexing problem. New HCC MELD and allocation algorithms provide greater observation of HCC patients, many while receiving local-regional treatments. Potential benefits of local-regional treatment for limiting HCC recurrence post-OLT remain incompletely understood. Therefore we aimed to define HCC specific prognostic factors affecting recurrence in a contemporary, multi-center cohort of HCC patients undergoing OLT and specifically whether local-regional therapies limited recurrence. We identified 441 patients undergoing OLT for HCC at three major transplant centers from 2008-2013. Cox regression was used to analyze covariate-adjusted recurrence and mortality rates post-OLT. "Bridging" or "down-staging" therapy was used in 238 patients (54%) with transarterial chemoembolization (TACE) being used in 170 (71%) of treated patients. The survival rate post-OLT was 88% and 78% at 1 and 3 years, respectively, with HCC recurrence (28% of deaths) significantly increasing mortality rate (HR=19.87, p<0.0001). Tumor size, not tumor number, either at presentation or on explant independently predicted HCC recurrence (HR 1.36 and 1.73, respectively, p<0.05) with a threshold effect noted at 4.0 cm size. Local-regional therapy (TACE) reduced HCC recurrence by 64% when adjusting for presenting tumor size (HR 0.36, p<0.05). Explant tumor size and microvascular invasion predicted mortality (HR 1.19 and 1.51, respectively, p<0.05) and pathologic response to therapy (TACE or RFA) significantly decreased explant tumor size (0.56-1.62 cm diameter reduction, p<0.05). HCC tumor size at presentation or explant is the most important predictor for HCC recurrence post-OLT. Local-regional therapy to achieve a pathologic response (decreasing tumor size) can limit HCC recurrences post-OLT. This article is protected by copyright

  5. An Intercomparison of the Dynamical Cores of Global Atmospheric Circulation Models for Mars

    NASA Technical Reports Server (NTRS)

    Hollingsworth, Jeffery L.; Bridger, Alison F. C.; Haberle, Robert M.

    1998-01-01

    This is a Final Report for a Joint Research Interchange (JRI) between NASA Ames Research Center and San Jose State University, Department of Meteorology. The focus of this JRI has been to evaluate the dynamical 'cores' of two global atmospheric circulation models for Mars that are in operation at the NASA Ames Research Center. The two global circulation models in use are fundamentally different: one uses spherical harmonics in its horizontal representation of field variables; the other uses finite differences on a uniform longitude-latitude grid. Several simulations have been conducted to assess how the dynamical processors of each of these circulation models perform using identical 'simple physics' parameterizations. A variety of climate statistics (e.g., time-mean flows and eddy fields) have been compared for realistic solstitial mean basic states. Results of this research have demonstrated that the two Mars circulation models with completely different spatial representations and discretizations produce rather similar circulation statistics for first-order meteorological fields, suggestive of a tendency for convergence of numerical solutions. Second and higher-order fields can, however, vary significantly between the two models.

  6. An Intercomparison of the Dynamical Cores of Global Atmospheric Circulation Models for Mars

    NASA Technical Reports Server (NTRS)

    Hollingsworth, Jeffery L.; Bridger, Alison F. C.; Haberle, Robert M.

    1998-01-01

    This is a Final Report for a Joint Research Interchange (JRI) between NASA Ames Research Cen- ter and San Jose State University, Department of Meteorology. The focus of this JRI has been to evaluate the dynamical "cores" of two global atmospheric circulation models for Mars that are in operation at the NASA Ames Research Center. ne two global circulation models in use are fundamentally different: one uses spherical harmonics in its horizontal representation of field variables; the other uses finite differences on a uniform longitude-latitude grid. Several simulations have been conducted to assess how the dynamical processors of each of these circulation models perform using identical "simple physics" parameterizations. A variety of climate statistics (e.g., time-mean flows and eddy fields) have been compared for realistic solstitial mean basic states. Results of this research have demonstrated that the two Mars circulation models with completely different spatial representations and discretizations produce rather similar circulation statistics for first-order meteorological fields, suggestive of a tendency for convergence of numerical solutions. Second and higher-order fields can, however, vary significantly between the two models.

  7. Enhancement of Programmed Death Ligand 2 on Hepatitis C Virus Infected Hepatocytes by Calcineurin Inhibitors

    PubMed Central

    Koike, Kazuko; Takaki, Akinobu; Yagi, Takahito; Iwasaki, Yoshiaki; Yasunaka, Tetsuya; Sadamori, Hiroshi; Shinoura, Susumu; Umeda, Yuzo; Yoshida, Ryuichi; Sato, Daisuke; Nobuoka, Daisuke; Utsumi, Masashi; Miyake, Yasuhiro; Ikeda, Fusao; Shiraha, Hidenori; Fujiwara, Toshiyoshi; Yamamoto, Kazuhide

    2015-01-01

    Background Post orthotopic liver transplantation (OLT) viral hepatitis is an immunological condition where immune cells induce hepatitis during conditions of immune-suppression. The immune-regulatory programmed death-1 (PD-1)/PD-ligand 1 system is acknowledged to play important roles in immune-mediated diseases. However, the PD-1/PD-L2 interaction is not well characterized, with PD-L2 also exhibiting an immunostimulatory function. We hypothesized that this atypical molecule could affect the recurrence of post-OLT hepatitis. To test this hypothesis, we conducted immunohistochemical staining analysis and in vitro analysis of PD-L2. Methods The expression of PD-L2 was evaluated in liver biopsy specimens from patients with chronic hepatitis B (n = 15), post-OLT hepatitis B (n = 8), chronic hepatitis C (n = 48), and post-OLT hepatitis C (CH-C-OLT) (n = 14). The effect of calcineurin inhibitors (CNIs) and hepatitis C virus (HCV) on PD-L2 expression was investigated in hepatoma cell lines. Results The PD-L2 was highly expressed on CH-C-OLT hepatocytes. Treatment of hepatoma cell lines with CNIs resulted in increased PD-L2 expression, especially in combination with HCV core or NS3 protein. Transfection of cell lines with PD-L2 containing plasmid resulted in high intercellular adhesion molecule-1 (ICAM-1) expression, which might enhance hepatitis activity. Conclusions The PD-L2 is highly expressed on CH-C-OLT hepatocytes, whereas HCV proteins, in combination with CNIs, induce high expression of PD-L2 resulting in elevated expression of ICAM-1. These findings demonstrate the effect of CNIs on inducing PD-L2 and subsequent ICAM-1 expression, effects that may produce inflammatory cell infiltration in post-OLT hepatitis C. PMID:25675203

  8. Employment after liver transplantation: a review.

    PubMed

    Huda, A; Newcomer, R; Harrington, C; Keeffe, E B; Esquivel, C O

    2015-03-01

    Return to productive employment is often an important milestone in the recovery and rehabilitation process after liver transplantation (OLT). This literature review identifies factors associated with employment in patients who underwent OLT. We searched PubMed for articles that addressed the various factors affecting employment after OLT. The studies demonstrated improvement in the quality of life and examined factors that predicted whether patients would return to work after OLT. Demographic variable associated with posttransplant employment included young age, male sex, college degree, Caucasian race, and pretransplant employment. Patients with alcohol-related liver disease had a significantly lower rate of employment than did those with other etiologies of liver disease. Recipients who were employed after transplantation had a significantly better posttransplant functional status than did those who were not employed. Economic pressures are increasing the expectation that patients who undergo successful OLT will return to work. Thus, transplant teams need to have a better understanding of posttransplant work outcomes for this vulnerable population, and greater attention must be paid to the full social rehabilitation of transplant recipients. Specific interventions for OLT recipients should be designed to evaluate and change their health perceptions and encourage their return to work. Published by Elsevier Inc.

  9. The Lord’s Resistance Army Wicked Problem

    DTIC Science & Technology

    2012-03-14

    alarming proportions after the failure of the Juba Peace Talks and “Operation Lightning Thunder” ( OLT ). Consequently between September 2008 and December...phase, followed with an assault by ground forces.60 The planners of OLT had assumed that the air strikes would have a decisive effect on the morale...different capabilities. 18 During OLT , dozens of LRA officers were killed or captured or simply surrendered and LRA’s core fighters were reduced to

  10. Operative Technique and Clinical Outcome in Endoscopic Core Decompression of Osteochondral Lesions of the Talus: A Pilot Study

    PubMed Central

    Beck, Sascha; Claßen, Tim; Haversath, Marcel; Jäger, Marcus; Landgraeber, Stefan

    2016-01-01

    Background Revitalizing the necrotic subchondral bone and preserving the intact cartilage layer by retrograde drilling is the preferred option for treatment of undetached osteochondral lesions of the talus (OLT). We assessed the effectiveness of Endoscopic Core Decompression (ECD) in treatment of OLT. Material/Methods Seven patients with an undetached OLT of the medial talar dome underwent surgical treatment using an arthroscopically-guided transtalar drill meatus for core decompression of the lesion. Under endoscopic visualization the OLT was completely debrided while preserving the cartilage layer covering the defect. The drill tunnel and debrided OLT were filled using an injectable bone graft substitute. Various clinical scores, radiographic imaging, and MRI were evaluated after a mean follow-up of 24.1 months. Results The American Orthopedic Foot and Ankle Society Score significantly improved from 71.0±2.4 to 90.3±5.9, and the Foot and Ankle Disability Index improved from 71.8±11.1 to 91.7±4.8. Radiographically, we observed good bone remodelling of the medial talar dome contour within 3 months. In MRI, an alteration of the bony signal of the drill tunnel and the excised OLT remained for more than 12 months. Conclusions First follow-up results for the surgical technique described in this study are highly promising for treatment of undetached stable OLT grade II or transitional stage II–III according to the Pritsch classification. Even lesions larger than 150 mm2 showed good clinical scores, with full restoration of the medial talar dome contour in radiographic imaging. PMID:27362485

  11. Operative Technique and Clinical Outcome in Endoscopic Core Decompression of Osteochondral Lesions of the Talus: A Pilot Study.

    PubMed

    Beck, Sascha; Claßen, Tim; Haversath, Marcel; Jäger, Marcus; Landgraeber, Stefan

    2016-06-30

    BACKGROUND Revitalizing the necrotic subchondral bone and preserving the intact cartilage layer by retrograde drilling is the preferred option for treatment of undetached osteochondral lesions of the talus (OLT). We assessed the effectiveness of Endoscopic Core Decompression (ECD) in treatment of OLT. MATERIAL AND METHODS Seven patients with an undetached OLT of the medial talar dome underwent surgical treatment using an arthroscopically-guided transtalar drill meatus for core decompression of the lesion. Under endoscopic visualization the OLT was completely debrided while preserving the cartilage layer covering the defect. The drill tunnel and debrided OLT were filled using an injectable bone graft substitute. Various clinical scores, radiographic imaging, and MRI were evaluated after a mean follow-up of 24.1 months. RESULTS The American Orthopedic Foot and Ankle Society Score significantly improved from 71.0±2.4 to 90.3±5.9, and the Foot and Ankle Disability Index improved from 71.8±11.1 to 91.7±4.8. Radiographically, we observed good bone remodelling of the medial talar dome contour within 3 months. In MRI, an alteration of the bony signal of the drill tunnel and the excised OLT remained for more than 12 months. CONCLUSIONS First follow-up results for the surgical technique described in this study are highly promising for treatment of undetached stable OLT grade II or transitional stage II-III according to the Pritsch classification. Even lesions larger than 150 mm2 showed good clinical scores, with full restoration of the medial talar dome contour in radiographic imaging.

  12. [Long-term, tumor-free survival after radiotherapy combining hepatectomy-Whipple en bloc and orthotopic liver transplantation for early-stage hilar cholangiocarcinoma].

    PubMed

    Wu, You-min; Johlin, Frederick C; Rayhill, Stephen C; Jensen, Chris S; Jin, Xie; Mitros, Frank A

    2009-08-01

    To report the experience in surveillance and early detection of cholangiocarcinoma (CC) and in using en bloc total hepatectomy-pancreaticoduodenectomy-orthotopic liver transplantation (OLT-Whipple) to achieve complete eradication of early-stage CC complicating primary sclerosing cholangitis (PSC). Asymptomatic PSC patients underwent surveillance using endoscopic ultrasound and endoscopic retrograde cholangiopancreatography (ERCP) with multilevel brushings for cytological evaluation. Patients diagnosed with CC were treated with combined extra-beam radiotherapy, lesion-focused brachytherapy, and OLT-Whipple. Between January 1988 and February 2001, 42 of 119 PSC patients were followed according to the surveillance protocol. CC was detected in 8 patients, 6 of whom underwent OLT-Whipple. Of those 6 patients, 4 had stage I CC, and 2 had stage II CC. All 6 OLT-Whipple patients received combined external-beam and brachytherapy radiotherapy. The median time from diagnosis to OLT-Whipple was 144 days. One patient died 55 months post-transplant of an unrelated cause, without tumor recurrence. The other 5 were well without recurrence at 79, 82, 108, 128, 129 and 145 months. For patients with PSC, ERCP surveillance cytology and intralumenal endoscopic ultrasound examination allow for early detection of CC. Broad and lesion-focused radiotherapy combined with OLT-Whipple to remove the biliary epithelium en bloc offers promising long-term, tumor-free survival. All patients tolerated this extensive surgery well with good quality of life following surgery and recovery. These findings support consideration of the complete excision of an intact biliary tree via OLT-Whipple in patients with early-stage hilar CC complicating PSC.

  13. Increased Risk of Death for Patients on the Waitlist for Liver Transplant Residing at Greater Distance From Specialized Liver Transplant Centers in the United States.

    PubMed

    Cicalese, Luca; Shirafkan, Ali; Jennings, Kristofer; Zorzi, Daria; Rastellini, Cristiana

    2016-10-01

    We have previously shown that patients listed for orthotopic liver transplantation (OLT) in United Network for Organ Sharing Region 4 (Texas and Oklahoma) have higher waitlist mortality rates when residing more than 30 miles from specialized liver transplant centers (LTC). Considering that findings might only be exclusive for this region with its peculiarities in terms of having the highest land surface extensions, lowest population densities, and largest rural populations. We investigated the entire OLT patient population in the United States to assess if our previous regional findings are nationally validated and if a rural, micropolitan, or metropolitan residence location affects outcome of waitlisted OLT patients in the nation. Patients waiting for OLT in the United States from 2002 to 2012 were stratified by distance from the patients' residence to LTC and by Rural Urban Commuting Area (RUCA) codes classification. Statistical analyses were performed to evaluate risk of mortality on the waitlist and the likelihood to receive an OLT using a Cox proportional hazards model and a generalized additive model with a logistic link. Survival time and probability of death while on the waitlist for OLT using distance to LTC showed significant increased risk with the distance (P = 0.001 and P < 0.0001, respectively). At the same time, using RUCA classification as the variable did not show significance (P = 0.14 and P = 0.73, respectively). Distance from an LTC is a risk factor of mortality on the waitlist for OLT, whereas RUCA classification is not a significant factor.

  14. Pathological Roles of Interleukin-22 in the Development of Recurrent Hepatitis C after Liver Transplantation

    PubMed Central

    Li, Jin; Cheung, Eddie; Li, Hanwei; Zhao, Jingmin; Liu, Hongling; Liu, Zhenwen; Zhang, Min

    2016-01-01

    Objective The aim of this study was to longitudinally evaluate and analyze the role of interleukin-22-producing CD4 positive cells (IL-22) in the pathogenesis of Hepatitis C Virus recurrence after Orthotopic Liver Transplantation (HCV-OLT). Methods 15 HCV-OLT, 15 age- and gender- matched non-HCV post-OLT (OLT) and 15 hepatitis C virus infected (HCV) patients were enrolled into our study from the liver transplantation and research center at Beijing 302 Hospital. We determined the frequencies of IL-22 using flow cytometry and expression of IL-22 mRNA using PCR in peripheral blood and liver tissue. We also divided HCV-OLT patients into rapid fibrosis progression (RFP) and slow fibrosis progression (SFP), examined IL-22 cells and analyzed the correlations between IL-22 frequencies and liver injury, fibrosis and clinical parameters. Moreover, we investigated the role of IL-22 in Human Hepatic Stellate Cells (HSCs). Results The levels of serum IL-22, frequencies of IL-22 producing cells in peripheral blood mononuclear cells, and expression of IL-22 mRNA and protein in the liver in the HCV-OLT group were significantly higher than that in the HCV and OLT groups. Furthermore, eight (53.3%) patients developed RFP after two years; another three patients were diagnosed liver cirrhosis. The frequencies of IL-22 were much higher in RFP compared with SFP, while no significant difference existed between OLT and SFP. Intrahepatic IL-22 positive cells were located in fibrotic areas and significantly correlated with α-smooth muscle actin (α-SMA) and fibrosis staging scores, not with grading scores and HCRVNA. In vitro, IL-22 administration prevented HSCs apoptosis, promoted HSCs proliferation and activation, up-regulated the expression of HSC-sourced growth factors including α-SMA, TGF-β and TIMP-1, and increased the production of liver fibrosis markers including laminin, hyaluronic acid and collagen type IV. Conclusion Peripheral and intrahepatic IL-22 is up-regulated and plays

  15. Extracorporeal albumin dialysis in patients with Amanita phalloides poisoning.

    PubMed

    Faybik, Peter; Hetz, Hubert; Baker, Amir; Bittermann, Clemens; Berlakovich, Gabriela; Werba, Alois; Krenn, Claus-Georg; Steltzer, Heinz

    2003-01-01

    Ingestion of Amanita phalloides is the most common cause of lethal mushroom poisoning. The relative late onset of symptoms is a distinct diagnostic feature of Amanita intoxication and also the main reason of failure for extracorporeal removal of Amanita-specific toxins from the gut and circulation. Extracorporeal albumin dialysis (ECAD) has been used on six consecutive patients admitted after A. phalloides poisoning with acute liver failure (ALF). Six patients, with mean age of 46 years (range: 9-70 years), underwent one to three ECAD treatments. The mean time from mushroom ingestion until the first ECAD treatment was 76 h. Two patients regenerated spontaneously under ECAD treatment and orthotopic liver transplantation (OLT) could be avoided. Two patients were successfully bridged to OLT and one patient died because of cerebral herniation. One patient was treated with ECAD immediately after OLT because of the graft dysfunction and survived without re-transplantation. ECAD appeared to be a successful treatment perspective in supporting liver regeneration or in sufficient bridging to OLT and also in treatment of graft dysfunction after OLT in patients with A. phalloides poisoning.

  16. Algorithm for prioritization of patients on the waiting list for liver transplantation.

    PubMed

    Gambato, M; Senzolo, M; Canova, D; Germani, G; Tomat, S; Masier, A; Russo, F P; Perissinotto, E; Zanus, G; Cillo, U; Burra, P

    2007-01-01

    Prioritization of patients on the waiting list (WL) for OLT is still a critical issue. Numerous models have been developed to predict mortality before and after OLT. The aim of the study was to prospectively evaluate cirrhotics with and without hepatocellular carcinoma (HCC) undergoing orthotopic liver transplantation (OLT) severity of liver disease on the WL and at transplant, mortality on the WL and after OLT, and their correlations. An algorithm based on seven patient variables (MELD, CTP, UNOS, HCC, BMI, waiting time, age) was created by software dedicated to prioritize patients on the waiting list. We evaluated 118 patients including 75 men and 43 women of age range 19 to 66 years, who underwent OLT from July 2004 to June 2006. Mean CTP and MELD at listing were 8.44 (range 6-12) and 13 (range 2-24), respectively. Overall mortality on the WL at 24 months was 13%, which was significantly higher among patients with MELD > 25 compared to patients with MELD 0 to 15 (P < .0001) or MELD 16 to 25 (P = .0007) at listing. Mean MELD at OLT was 15 (range 7-36), which was significantly lower in patients with than without HCC (MELD 12 vs 16; P = .0003). Six hundred-day patient survival was significantly lower among patients with MELD > 25 compared to patients with MELD < 25 at OLT (P = .017), whereas no difference in survival was observed between patients with and without HCC. The sickest patients are characterized by high mortality both on the waiting list and after liver transplantation. Patients with HCC are transplanted in better condition compared to patients without HCC with the same survival.

  17. Bridging Locoregional Therapy Prolongs Survival in Patients Listed for Liver Transplant with Hepatocellular Carcinoma

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

    Xing, Minzhi; Sakaria, Sonali; Dhanasekaran, Renumathy

    Background and AimsTo evaluate the long-term survival benefit of bridging locoregional therapy (LRT) prior to orthotopic liver transplantation (OLT) in patients with hepatocellular carcinoma (HCC) within Milan criteria.MethodsOur transplant center registry was studied for all HCC patients within the Milan criteria who were listed for OLT from 1998 to 2013. Baseline clinical characteristics and median overall survival (OS) were calculated and stratified by LRT, OLT status, and wait times. Survival analysis was conducted using Kaplan–Meier estimation and log-rank test.ResultsOf 265 listed, 205 underwent OLT (mean follow-up 7.6 years). Of 205, 111 received bridging LRT (A), and 94 did not (B).more » Both were similar in demographics and tumor characteristics (p > 0.05). Median OS from HCC for A/B were 86.4 vs. 68.9 months (p = 0.01). Median OS from OLT for A/B were 74.6 vs. 63.6 months (p = 0.03). On multivariate analysis, independent predictors for survival from HCC were bridging LRT (p = 0.002) and high wait time (p = 0.008); independent predictors for survival from OLT were bridging LRT (p = 0.005) and high wait time (p = 0.005). Of 60 who were listed but did not undergo transplant, 44 received LRT (C) and 16 received best supportive care (D). Median OS from HCC for C/D were 37.1 vs. 24.8 months (p = 0.03).ConclusionsBridging LRT and high wait times were independent positive prognostic factors for survival from HCC diagnosis and OLT.« less

  18. Primary non-function is frequently associated with fatty liver allografts and high mortality after re-transplantation.

    PubMed

    Kulik, Ulf; Lehner, Frank; Klempnauer, Jürgen; Borlak, Jürgen

    2017-08-01

    The shortage of liver donations demands the use of suboptimal grafts with steatosis being a frequent finding. Although ≤30% macrovesicular steatosis is considered to be safe the risk for primary non-function (PNF) and outcome after re-transplantation (re-OLT) is unknown. Among 1205 orthotopic liver transplantations performed at our institution the frequency, survival and reason of re-OLT were evaluated. PNF (group A) cases and those with initial transplant function but subsequent need for re-OLT (group B) were analysed. Histopathology and clinical judgement determined the cause of PNF and included an assessment of hepatic steatosis. Additionally, survival of fatty liver allografts (group C) not requiring re-OLT was considered in Kaplan-Meier and multivariate regression analysis. A total of 77 high urgency re-OLTs were identified and included 39 PNF cases. Nearly 70% of PNF cases were due to primary fatty liver allografts. The 3-month in-hospital mortality for PNF cases after re-OLT was 46% and the mean survival after re-OLT was 0.5 years as compared to 5.2 and 5.1 years for group B, C, respectively, (P<.008). In multivariate Cox regression analysis only hepatic steatosis was associated with an inferior survival (HR 4.272, P=.002). The MELD score, donor BMI, age, cold ischaemic time, ICU stay, serum sodium and transaminases did not influence overall survival. Our study highlights fatty liver allografts to be a major cause for PNF with excessive mortality after re-transplantation. The findings demand the development of new methods to predict risk for PNF of fatty liver allografts. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Comparison of macrophage migration inhibitory factor and neutrophil gelatinase-associated lipocalin-2 to predict acute kidney injury after liver transplantation: An observational pilot study

    PubMed Central

    Schiefer, Judith; Miller, Edmund J.; Berlakovich, Gabriela A.

    2017-01-01

    Introduction Several biomarkers have been suggested as early predictors of acute kidney injury (AKI) after orthotopic liver transplantation (OLT). Neutrophil gelatinase-associated lipocalin-2 (NGAL) appears to be a promising predictor of AKI after OLT, but the clinical benefit remains to be proven. Recently, systemic macrophage migration inhibitory factor (MIF) has been proposed as early indicator for requirement of renal replacement therapy after OLT. The aim of this prospective, observational pilot study was to compare the predictive values of serum and urinary MIF for severe AKI after OLT to those of serum and urinary NGAL. Methods Concentrations of MIF and NGAL were measured in serum and urine samples collected from patients undergoing OLT. Acute kidney injury was classified according to the KDIGO criteria, with stages 2 and 3 summarized as severe AKI. Areas under the receiver operating curves (AUC) were calculated to assess predictive values of MIF and NGAL for the development of severe AKI. Results Forty-five patients (mean age 55±8 years) were included. Nineteen patients (38%) developed severe AKI within 48 hours after reperfusion. At the end of OLT, serum MIF was predictive of severe AKI (AUC 0.73; 95% confidence intervals, CI 0.55–0.90; P = 0.03), whereas urinary MIF, serum NGAL, and urinary NGAL were not. On the first postoperative day, serum MIF (AUC 0.78; CI 0.62–0.93; P = 0.006), urinary MIF (AUC 0.71; CI 0.53–0.88; P = 0.03), and urinary NGAL (AUC 0.79; CI 0.64–0.93; P = 0.02) were predictive for severe AKI, while serum NGAL was not. Conclusion In the setting of OLT, MIF and NGAL had similar predictive values for the development of severe AKI. PMID:28813470

  20. Cost of achieving equivalent outcomes in sicker patients after liver transplant.

    PubMed

    Dhar, Vikrom K; Wima, Koffi; Kim, Young; Hoehn, Richard S; Jung, Andrew D; Ertel, Audrey E; Diwan, Tayyab S; Paterno, Flavio; Shah, Shimul A

    2018-03-01

    We aimed to characterize variability in cost after straightforward orthotopic liver transplant (OLT). Using the University HealthSystem Consortium and Scientific Registry of Transplant Recipients databases, we identified patients who underwent OLT between 2011 and 2014. Patients meeting criteria for straightforward OLT, defined as length of stay < 14 days with discharge to home, were selected (n = 5763) and grouped into tertiles (low, medium, high) according to cost of perioperative stay. Patients undergoing straightforward OLT were of similar demographics regardless of cost. High cost patients were more likely to require preoperative hemodialysis, had higher severity of illness, and higher model for end-stage liver disease (MELD) (p < 0.01). High cost patients required greater utilization of resources including lab tests, blood transfusions, and opioids (p < 0.01). Despite having higher burden of disease and requiring increased resource utilization, high cost OLT patients with a straightforward perioperative course were shown to have identical 2-year graft and overall survival compared to lower cost patients (p = 0.82 and p = 0.63), respectively. Providing adequate perioperative care for OLT patients with higher severity of illness and disease burden requires increased cost and resource utilization; however, doing so provides these patients with long term survival equivalent to more routine patients. Copyright © 2017 International Hepato-Pancreato-Biliary Association Inc. Published by Elsevier Ltd. All rights reserved.

  1. Reconfigurable multiport EPON repeater

    NASA Astrophysics Data System (ADS)

    Oishi, Masayuki; Inohara, Ryo; Agata, Akira; Horiuchi, Yukio

    2009-11-01

    An extended reach EPON repeater is one of the solutions to effectively expand FTTH service areas. In this paper, we propose a reconfigurable multi-port EPON repeater for effective accommodation of multiple ODNs with a single OLT line card. The proposed repeater, which has multi-ports in both OLT and ODN sides, consists of TRs, BTRs with the CDR function and a reconfigurable electrical matrix switch, can accommodate multiple ODNs to a single OLT line card by controlling the connection of the matrix switch. Although conventional EPON repeaters require full OLT line cards to accommodate subscribers from the initial installation stage, the proposed repeater can dramatically reduce the number of required line cards especially when the number of subscribers is less than a half of the maximum registerable users per OLT. Numerical calculation results show that the extended reach EPON system with the proposed EPON repeater can save 17.5% of the initial installation cost compared with a conventional repeater, and can be less expensive than conventional systems up to the maximum subscribers especially when the percentage of ODNs in lightly-populated areas is higher.

  2. Malodor reductions and improved oral hygiene by toothbrushing and mouthrinsing.

    PubMed

    Nandlal, B; Shahikumar, P; Avinash, B S; Sreenivasan, P K; Subramanyam, R

    2016-01-01

    This clinical study compared the effects of an antibacterial regimen, comprising a triclosan toothpaste and a 0.075% cetylpyridinium chloride (CPC) mouthrinse, on malodor, self-reported malodor, and oral hygiene measures such as dental plaque, gingivitis, and bleeding relative to brushing with a fluoride toothpaste. At baseline, 36 subjects were evaluated for malodor (9-point organoleptic scale [OLT]), dental plaque (Turesky modification of Quigley-Hein; PI), gingivitis (Lφe-Silness; GI) and bleeding (Ainamo and Bay; BI) and randomized to (1) tooth brushing with fluoride toothpaste, or (2) a regimen comprising tooth brushing with a triclosan toothpaste and mouth rinsing with CPC mouthrinse. After the first use of assigned treatments, subjects were evaluated for malodor 2 h after breakfast (OLT-2 h) and used provided treatments for the next 14 days. On the 7 th and 14 th days, subjects refrained from oral hygiene for 12 h before evaluations (OLT, PI, GI, and BI) and then performed oral hygiene at the dental clinic. Subjects were evaluated for malodor 2 h after breakfast (OLT-2 h) and self-assessed their malodor on a 100 mm visual analog scale (VAS). Treatment groups demonstrated no significant differences in OLT, PI, GI, BI at baseline (P > 0.05). OLT-2 h scores after the first use of regimen and after tooth brushing alone were 5.94 and 6.21, respectively, and were statistically significantly different (P < 0.05). Correspondingly, the regimen demonstrated progressive reductions in OLT and OLT-2 h on the 7 th and 14 th day evaluations (5.81, 4.88, and 5.09, 4.20, respectively) and were significantly lower than after tooth brushing alone (6.49, 6.18, and 6.35, 5.99, respectively) (P < 0.05). From the 7 th to 14 th days, the regimen also demonstrated progressively lower PI, GI, BI, and self-reported malodor (VAS scores) which were significantly lower than tooth brushing alone (P < 0.05). Results from this study demonstrated that a regimen comprising a triclosan

  3. Structural shifts of fecal microbial communities in rats with acute rejection after liver transplantation.

    PubMed

    Xie, Yirui; Luo, Zhuanbo; Li, Zhengfeng; Deng, Min; Liu, Hao; Zhu, Biao; Ruan, Bing; Li, Lanjuan

    2012-08-01

    Bacterial translocation and the development of sepsis after orthotopic liver transplantation (OLT) may be promoted by immunological damage to the intestinal mucosa or by quantitative and qualitative changes in intestinal microbiota. This study monitored structural shifts of gut microbiota in rats with OLT using PCR-denaturing gradient gel electrophoresis (DGGE) and real-time quantitative PCR (RT-qPCR). RT-qPCR targets six major microorganisms (Domain Bacteria, Bacteroides, Bifidobacteria, Enterobacteriaceae, Lactobacillus and Clostridium leptum subgroup). Isograft, Allograft and Sham model were studied. Bacterial translocation to host organs and plasma endotoxin were determined. Alteration in gut microbiota was associated with the elevation of plasma endotoxin and a higher rate of bacterial translocation (BT) to liver in rats with acute rejection. Dynamic analysis of DGGE fingerprints showed that the gut microbiota structure of animals in the three groups was similar before the operation. But significant alterations in the composition of fecal microbiota in Allograft group were observed at 1 and 2 weeks after the OLT. The acute rejection was accompanied by the shifts of gut microbiota towards members of Bacteroides and Ruminococcus. Results from RT-qPCR indicated that Bacteroides significantly increased at 2 weeks after the OLT, whereas numbers of Bifidobacterium spp. decreased at 1 week and recovered at 2 weeks after the OLT. In summary, our data showed that rats with acute rejection after OLT exhibited significant structure shifts in the gut microbiota which dominant by overgrowth of Bacteroides and Ruminococcus, and these were associated with elevation of plasma endotoxin and higher rate of BT.

  4. Donor age does not influence 12-month outcome after orthotopic liver transplantation.

    PubMed

    Faber, W; Seehofer, D; Puhl, G; Guckelberger, O; Bertram, C; Neuhaus, P; Bahra, M

    2011-12-01

    Orthotopic liver transplantation (OLT) is the most effective treatment for patients with end-stage liver disease to date. The discrepancy between the numbers of donor livers and recipients has become a significant problem, resulting in a high patient mortality on the waiting list. Due to this, an expansion of the donor pool is necessary, for example, by accepting donor grafts from elderly donors. The aim of this study was to investigate the outcome after OLT depending on donor age. We retrospectively evaluated the outcome of 272 full-size cadaveric initial single OLTs within 12 months after OLT. The outcome was analyzed by dividing the collective into four donor age categories: donor age under 50, between 50 and 59, between 60 and 69, and 70 years or above. The outcome after OLT in these patients was retrospectively reviewed by using a prospective database. Patients positive for hepatitis C were excluded from the analysis. No increase of initial nonfunction was observed. Furthermore, no significant differences with regard to surgical complications and serum liver parameter were observed between the groups. Neither patient mortality rates nor rejection rates were different between the groups. However, ischemic-type biliary lesion rates increased significantly with donor age over 70 years (P<.05). The acceptance of liver grafts from older donors is a possible alternative to narrow the gap between donated and required organs. Safe use under optimal protocols is necessary to avoid a deterioration of post-OLT results. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. Rotational Thromboelastometry or Conventional Coagulation Tests in Liver Transplantation: Comparing Blood Loss, Transfusions, and Cost.

    PubMed

    Smart, Laura; Mumtaz, Khalid; Scharpf, Danielle; Gray, Nicole O'Bleness; Traetow, Daniel; Black, Sylvester; Michaels, Anthony J; Elkhammas, Elmahdi; Kirkpatrick, Robert; Hanje, A James

    Orthotopic liver transplantation (OLT) can be associated with significant bleeding requiring multiple blood product transfusions. Rotational thromboelastometry (ROTEM) is a point-of-care device that has been used to monitor coagulation during OLT. Whether it reduces blood loss/transfusions during OLT remains controversial. We aim to compare ROTEM with conventional coagulation tests (aPTT, PT, INR, platelet count, fibrinogen) to guide transfusion of platelets, cryoprecipitate, and fresh frozen plasma (FFP) during OLT over 3 years. Thirty-four patients who had transfusions guided by ROTEM were compared to 34 controls who received transfusions guided by conventional coagulation tests (CCT). Intraoperative blood loss, type/ amount of blood products transfused, and direct costs were compared between the two groups. The ROTEM group had significantly less intra-operative blood loss (2.0 vs. 3.0 L, p = 0.04) and fresh frozen plasma (FFP) transfusion (4 units vs. 6.5 units, p = 0.015) compared to the CCT group (2.0L vs. 3.0L, p = 0.04). However, total number of patients transfused cryoprecipitate was increased in ROTEM (n = 25;73%) as compared to CCT (n = 19; 56%), p = 0.033. The direct cost of blood products plus testing was reduced in the ROTEM group ($113,142.89 vs. $127,814.77). In conclusion implementation of a ROTEM-guided transfusion algorithm resulted in a reduction in intra-operative blood loss, FFP transfusion and a decrease in direct cost during OLT. ROTEM is a useful and safe point of care device in OLT setting.

  6. The Lord’s Resistance Army: The U.S. Response

    DTIC Science & Technology

    2012-04-11

    initiated “Operation Lightning Thunder” ( OLT ), a campaign intended to capture or kill senior LRA leaders in northeastern DRC, where they had...enlarged regional campaign is viewed as the continuation of OLT . While the UPDF has since succeeded in capturing or killing several LRA commanders

  7. A 20-year period of orthotopic liver transplantation activity in a single center: a time series analysis performed using the R Statistical Software.

    PubMed

    Santori, G; Andorno, E; Morelli, N; Casaccia, M; Bottino, G; Di Domenico, S; Valente, U

    2009-05-01

    In many Western countries a "minimum volume rule" policy has been adopted as a quality measure for complex surgical procedures. In Italy, the National Transplant Centre set the minimum number of orthotopic liver transplantation (OLT) procedures/y at 25/center. OLT procedures performed in a single center for a reasonably large period may be treated as a time series to evaluate trend, seasonal cycles, and nonsystematic fluctuations. Between January 1, 1987 and December 31, 2006, we performed 563 cadaveric donor OLTs to adult recipients. During 2007, there were another 28 procedures. The greatest numbers of OLTs/y were performed in 2001 (n = 51), 2005 (n = 50), and 2004 (n = 49). A time series analysis performed using R Statistical Software (Foundation for Statistical Computing, Vienna, Austria), a free software environment for statistical computing and graphics, showed an incremental trend after exponential smoothing as well as after seasonal decomposition. The predicted OLT/mo for 2007 calculated with the Holt-Winters exponential smoothing applied to the previous period 1987-2006 helped to identify the months where there was a major difference between predicted and performed procedures. The time series approach may be helpful to establish a minimum volume/y at a single-center level.

  8. Outcomes after liver transplantation of patients with Indo-Asian ethnicity.

    PubMed

    Rocha, Chiara; Perera, M Thamara; Roberts, Keith; Bonney, Glenn; Gunson, Bridget; Nightingale, Peter; Bramhall, Simon R; Isaac, John; Muiesan, Paolo; Mirza, Darius F

    2015-04-01

    The impact of ethnicity on outcomes after orthotopic liver transplantation (OLT) is unclear. The British Indo-Asian population has a high incidence of liver disease but its contribution to the national deceased donor pool is small. We evaluated access to and outcomes of OLT in Indo-Asians. We compared 182 Indo-Asians with white patients undergoing OLT. Matching criteria were transplantation year, liver disease, age, sex. Donor and recipient characteristics, postoperative outcomes, including patient and graft survival, OLT era (early, 1987-2001; late, 2002-2011) were compared. Survival was also analyzed by underlying disease-acute liver failure (ALF) and chronic liver failure. Indo-Asians had higher diabetes incidence. There were no differences in waiting time for transplantation, despite smaller body size and more uncommon blood groups (B, AB) among Indo-Asians. In the early era, patient survival for Indo-Asians with ALF was worse when compared to whites. In the late era, graft and patient survival at 1, 2, and 5 years were similar between groups. This study demonstrates that Indo-Asian patients have equal access to OLT and comparable outcomes to whites in the United Kingdom. Survival has improved among Indo-Asian patients; this may be attributable to careful patient selection in case of ALF, though improvement of patient management may have contributed.

  9. Risk factors for alcohol relapse following orthotopic liver transplantation: a systematic review.

    PubMed

    Rustad, James K; Stern, Theodore A; Prabhakar, Maithri; Musselman, Dominique

    2015-01-01

    Each year, 5000-6000 individuals undergo orthotopic liver transplantation (OLT) in the United States, and of these, nearly 18% have alcoholic liver disease. Relapse to alcohol occurs in more than 40% of patients with OLT for alcoholic liver disease. We sought to identify factors that predict relapse to alcohol or medication nonadherence following OLT in patients with alcoholic liver disease and to review what randomized clinical interventions have addressed these factors following OLT. Our hypothesis was that there would be factors before and after OLT that predict relapse to alcohol following OLT, and that these, if targeted, might improve sobriety and associated outcomes of adherence with medications and appointments. We performed a review (focusing on articles published since 2004) with PubMed and MEDLINE searches using the following search terms: liver transplantation, recidivism, alcohol relapse, and predictors of alcohol relapse. We supplemented the online searches with manual reviews of article reference lists and selected relevant articles for further review by author consensus. In largely white populations, prospective studies document that shorter length of pretransplantation sobriety is a significant predictor of time to first drink and time to binge use. Presence of psychiatric comorbidity, high score on standardized High-risk Alcoholism Relapse Scale, and diagnosis of Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) alcohol dependence are predictive of posttransplantation alcohol relapse. Pretransplantation alcohol use history variables (e.g., family history of alcoholism) reliably discriminate between complete abstainers and those who drink, while medical and psychosocial characteristics at early post-liver transplantation period (e.g., more bodily pain) maximally discriminate patterns of alcohol use. Alcoholic individuals with early-onset, rapidly accelerating moderate use and early-onset, continuously increasing heavy use have

  10. Recipient’s Genetic R702W NOD2 Variant Is Associated with an Increased Risk of Bacterial Infections after Orthotopic Liver Transplantation

    PubMed Central

    van Hoek, Bart; van den Berg, Arie P.; Porte, Robert J.; Blokzijl, Hans; Coenraad, Minneke J.; Hepkema, Bouke G.; Schaapherder, Alexander F.; Ringers, Jan; Weersma, Rinse K.; Verspaget, Hein W.

    2013-01-01

    Introduction Orthotopic liver transplantation (OLT) is accompanied by a significant postoperative infection risk. Immunosuppression to prevent rejection increases the susceptibility to infections, mainly by impairing the adaptive immune system. Genetic polymorphisms in the lectin complement pathway of the donor have recently been identified as important risk determinants of clinically significant bacterial infection (CSI) after OLT. Another genetic factor involved in innate immunity is NOD2, which was reported to be associated with increased risk of spontaneous bacterial peritonitis in cirrhotic patients. Methods We assessed association of three genetic NOD2 variants (R702W, G908R and 3020insC) with increased risk of CSI after OLT. 288 OLT recipient-donor pairs from two tertiary referral centers were genotyped for the three NOD2 variants. The probability of CSI in relation to NOD2 gene variants was determined with cumulative incidence curves and log-rank analysis. Results The R702W NOD2 variant in the recipient was associated with CSI after OLT. Eight out of 15 (53.3%) individuals with a mutated genotype compared to 80/273 (29.3%) with wild type genotype developed CSI (p=0.027, univariate cox regression), illustrated by a higher frequency of CSI after OLT over time (p=0.0003, log rank analysis). Multivariate analysis (including the donor lectin complement pathway profile) showed independence of this R702W NOD2 association from other risk factors (HR 2.0; p=0.04). The other NOD2 variants, G908R and 3020insC, in the recipient were not associated with CSI. There was no association with CSI after OLT for any of the NOD2 variants in the donor. Conclusion The mutated NOD2 R702W genotype in the recipient is independently associated with an increased risk of bacterial infections after liver transplantation, indicating a predisposing role for this genetic factor impairing the recipient’s innate immune system. PMID:23977330

  11. Intestinal microbial variation may predict early acute rejection after liver transplantation in rats.

    PubMed

    Ren, Zhigang; Jiang, Jianwen; Lu, Haifeng; Chen, Xinhua; He, Yong; Zhang, Hua; Xie, Haiyang; Wang, Weilin; Zheng, Shusen; Zhou, Lin

    2014-10-27

    Acute rejection (AR) remains a life-threatening complication after orthotopic liver transplantation (OLT) and there are few available diagnostic biomarkers clinically for AR. This study aims to identify intestinal microbial profile and explore potential application of microbial profile as a biomarker for AR after OLT. The OLT models in rats were established. Hepatic graft histology, ultrastructure, function, and intestinal barrier function were tested. Ileocecal contents were collected for intestinal microbial analysis. Hepatic graft suffered from the ischemia-reperfusion (I/R) injury on day 1, initial AR on day 3, and severe AR on day 7 after OLT. Real-time quantitative polymerase chain reaction results showed that genus Faecalibacterium prausnitzii and Lactobacillus were decreased, whereas Clostridium bolteae was increased during AR. Notably, cluster analysis of denaturing gradient gel electrophoresis (DGGE) profiles showed the 7AR and 3AR groups clustered together with 73.4% similarity, suggesting that intestinal microbiota was more sensitive than hepatic function in responding to AR. Microbial diversity and species richness were decreased during AR. Phylogenetic tree analysis showed that most of the decreased key bacteria belonged to phylum Firmicutes, whereas increased key bacteria belonged to phylum Bacteroidetes. Moreover, intestinal microvilli loss and tight junction damage were noted, and intestinal barrier dysfunction during AR presented a decrease of fecal secretory immunoglobulin A (sIgA) and increase of blood bacteremia, endotoxin, and tumor necrosis factor-α. We dynamically detail intestinal microbial characterization and find a high sensitivity of microbial change during AR after OLT, suggesting that intestinal microbial variation may predict AR in early phase and become an assistant therapeutic target to improve rejection after OLT.

  12. Intestinal Microbial Variation May Predict Early Acute Rejection after Liver Transplantation in Rats

    PubMed Central

    Ren, Zhigang; Jiang, Jianwen; Lu, Haifeng; Chen, Xinhua; He, Yong; Zhang, Hua; Xie, Haiyang; Wang, Weilin; Zheng, Shusen; Zhou, Lin

    2014-01-01

    Background Acute rejection (AR) remains a life-threatening complication after orthotopic liver transplantation (OLT) and there are few available diagnostic biomarkers clinically for AR. This study aims to identify intestinal microbial profile and explore potential application of microbial profile as a biomarker for AR after OLT. Methods The OLT models in rats were established. Hepatic graft histology, ultrastructure, function, and intestinal barrier function were tested. Ileocecal contents were collected for intestinal microbial analysis. Results Hepatic graft suffered from the ischemia-reperfusion (I/R) injury on day 1, initial AR on day 3, and severe AR on day 7 after OLT. Real-time quantitative polymerase chain reaction results showed that genus Faecalibacterium prausnitzii and Lactobacillus were decreased, whereas Clostridium bolteae was increased during AR. Notably, cluster analysis of denaturing gradient gel electrophoresis (DGGE) profiles showed the 7AR and 3AR groups clustered together with 73.4% similarity, suggesting that intestinal microbiota was more sensitive than hepatic function in responding to AR. Microbial diversity and species richness were decreased during AR. Phylogenetic tree analysis showed that most of the decreased key bacteria belonged to phylum Firmicutes, whereas increased key bacteria belonged to phylum Bacteroidetes. Moreover, intestinal microvilli loss and tight junction damage were noted, and intestinal barrier dysfunction during AR presented a decrease of fecal secretory immunoglobulin A (sIgA) and increase of blood bacteremia, endotoxin, and tumor necrosis factor-α. Conclusion We dynamically detail intestinal microbial characterization and find a high sensitivity of microbial change during AR after OLT, suggesting that intestinal microbial variation may predict AR in early phase and become an assistant therapeutic target to improve rejection after OLT. PMID:25321166

  13. Investigating bang for your training buck: a randomized controlled trial comparing three methods of training clinicians in two core strategies of dialectical behavior therapy.

    PubMed

    Dimeff, Linda A; Harned, Melanie S; Woodcock, Eric A; Skutch, Julie M; Koerner, Kelly; Linehan, Marsha M

    2015-05-01

    The present study examined the efficacy of online training (OLT), instructor-led training (ILT), and a treatment manual (TM) in training mental health clinicians in two core strategies of Dialectical Behavior Therapy (DBT): chain analysis and validation. A randomized controlled trial compared OLT, ILT, and TM among clinicians naïve to DBT (N=172) who were assessed at baseline, post-training, and 30, 60, and 90 days following training. Primary outcomes included satisfaction, self-efficacy, motivation, knowledge, clinical proficiency, and clinical use. Overall, ILT outperformed OLT and TM in satisfaction, self-efficacy, and motivation, whereas OLT was the most effective method for increasing knowledge. The conditions did not differ in observer-rated clinical proficiency or self-reported clinical use, which both increased to moderate levels after training. In addition, ILT was particularly effective at improving motivation to use chain analysis, whereas OLT was particularly effective at increasing knowledge of validation strategies. These findings suggest that these types of brief, didactic trainings may be effective methods of increasing knowledge of new treatment strategies, but may not be sufficient to enable clinicians to achieve a high level of clinical use or proficiency. Additional research examining the possible advantages of matching training methods to types of treatment strategies may help to determine a tailored, more effective approach to training clinicians in empirically supported treatments. Copyright © 2015. Published by Elsevier Ltd.

  14. The needs and expectations of overseas liver transplant recipients' families in Taiwan: across different transplantation stages.

    PubMed

    Chen, H-M; Shih, F-Jong; Pan, Y-J; Shih, F J; Wang, S-S

    2014-04-01

    This study explored the needs and expectations of Taiwanese overseas liver transplant recipients' families (OLTRFs) across three liver transplantation stages. An exploratory qualitative method was applied to a purposive sample of OLTRFs who received guided face-to-face, semi-structured interviews. Data were subjected to content analysis. Nineteen OLTRF members (15 females, 4 males) aged between 29 and 71 years (mean, 55.1 years) for 19 patients who had end-stage liver diseases were interviewed regarding overseas liver transplantation (OLT) across three stages: pre-departure (first stage), stay in mainland China (second stage), and re-entry into Taiwan (third stage). Five types of needs across OLT stages were reported: (a) knowing precise operation schedule in advance (first to second stages); (b) sharing the caring burdens (second to third stages); (c) knowing the updated health status if possible (all stages); (d) obtaining timely psychological support (all stages); and (e) effective communications between health professionals in Taiwan and mainland China to ensure the caring quality (all stages). Furthermore, five expectations were reported: (a) more donor sources (first stage); (b) comprehensive caring strategies for OLT (first stage); (c) a comprehensive consultation system and timely assistance channels for OLT recipients and their families (second to third stages); (d) a legal and accessible therapy process (all stages); and (e) the cooperation with foreign countries and allowed experience sharing for better quality of patient care (all stages). Most ethnic Chinese believe that family is an integrated system; moreover, there is close attachment between OLT recipients and their families. The needs and expectations of the recipients' family across three transplantation stages were first reported in this project. With this knowledge, the health providers of related countries are empowered by a better understanding of the family's needs and expectations of these

  15. Extreme hepatic resections for the treatment of advanced hepatoblastoma: Are planned close margins an acceptable approach?

    PubMed

    Fonseca, Adriana; Gupta, Abha; Shaikh, Furqan; Ramphal, Raveena; Ng, Vicky; McGilvray, Ian; Gerstle, J Ted

    2018-02-01

    Orthotopic liver transplantation (OLT) is considered the standard for children with hepatoblastoma (HB) in whom complete surgical resection is not possible. However, OLT is not always available or feasible. To describe the outcome of children with HB who were initially deemed unresectable and underwent complex hepatectomy with planned close margins, and ultimately avoided OLT. Demographic data, surgical and pathologic details, and survival information were collected from children treated for HB between January 2010 to December 2015. Among six children (median age 12 months (3-41 months)), PRETEXT classification was III (n = 2), III/IV (n = 1), and IV (n = 3). Patients received a median of six cycles (range 4-7) of platinum-based induction chemotherapy; five received doxorubicin. Experienced pediatric surgeons performed extended right and left hepatectomy in five and one patients, respectively, with assistance of an experienced liver transplant surgeon (n = 4). Microscopic margins were positive (n = 2) and negative but close (n = 4; 2-5 mm). Two patients required vascular reconstruction of the vena cava. At median follow-up of 3.3 years (1.7-4.6 years), there was no evidence of local recurrence. One patient had recurrence of pulmonary disease 3 months after surgery. Patients with advanced HB treated with complex surgical resections with positive or close negative margins had good outcomes without OLT. We suggest that planned positive or close microscopic margins in highly selected HB patients may spare the morbidity of OLT and offer an alternative for those ineligible for OLT. Our experience illustrates the importance of a multidisciplinary team specialized in the management of liver tumors. © 2017 Wiley Periodicals, Inc.

  16. Summative Evaluation of the Office of Learning Technologies. Final Report

    ERIC Educational Resources Information Center

    Human Resources Development Canada, 2002

    2002-01-01

    The Office of Learning Technologies (OLT) was launched by Human Resources Canada (HRDC) in 1996 as part of an education and training strategy for adult learners. It was established with an annual budget of $6 million. As a contributions program, the OLT encourages and supports initiatives of various public and private sector partners to expand…

  17. Post-operative imaging in liver transplantation: State-of-the-art and future perspectives

    PubMed Central

    Girometti, Rossano; Como, Giuseppe; Bazzocchi, Massimo; Zuiani, Chiara

    2014-01-01

    Orthotopic liver transplantation (OLT) represents a major treatment for end-stage chronic liver disease, as well as selected cases of hepatocellular carcinoma and acute liver failure. The ever-increasing development of imaging modalities significantly contributed, over the last decades, to the management of recipients both in the pre-operative and post-operative period, thus impacting on graft and patients survival. When properly used, imaging modalities such as ultrasound, multidetector computed tomography, magnetic resonance imaging (MRI) and procedures of direct cholangiography are capable to provide rapid and reliable recognition and treatment of vascular and biliary complications occurring after OLT. Less defined is the role for imaging in assessing primary graft dysfunction (including rejection) or chronic allograft disease after OLT, e.g., hepatitis C virus (HCV) recurrence. This paper: (1) describes specific characteristic of the above imaging modalities and the rationale for their use in clinical practice; (2) illustrates main imaging findings related to post-OLT complications in adult patients; and (3) reviews future perspectives emerging in the surveillance of recipients with HCV recurrence, with special emphasis on MRI. PMID:24876739

  18. Epistaxis in end stage liver disease masquerading as severe upper gastrointestinal hemorrhage.

    PubMed

    Camus, Marine; Jensen, Dennis M; Matthews, Jason D; Ohning, Gordon V; Kovacs, Thomas O; Jutabha, Rome; Ghassemi, Kevin A; Machicado, Gustavo A; Dulai, Gareth S

    2014-10-14

    To describe the prevalence, diagnosis, treatment, and outcomes of end stage liver disease (ESLD) patients with severe epistaxis thought to be severe upper gastrointestinal hemorrhage (UGIH). This observational single center study included all consecutive patients with ESLD and epistaxis identified from consecutive subjects hospitalized with suspected UGIH and prospectively enrolled in our databases of severe UGIH between 1998 and 2011. A total of 1249 patients were registered for severe UGIH in the data basis, 461 (36.9%) were cirrhotics. Epistaxis rather than UGIH was the bleeding source in 20 patients. All patients had severe coagulopathy. Epistaxis was initially controlled in all cases. Fifteen (75%) subjects required posterior nasal packing and 2 (10%) embolization in addition to correction of coagulopathy. Five (25%) patients died in the hospital, 12 (60%) received orthotopic liver transplantation (OLT), and 3 (15%) were discharged without OLT. The mortality rate was 63% in patients without OLT. Severe epistaxis in patients with ESLD is (1) a diagnosis of exclusion that requires upper endoscopy to exclude severe UGIH; and (2) associated with a high mortality rate in patients not receiving OLT.

  19. [Portopulmonary hypertension: Updated review].

    PubMed

    Rodríguez-Almendros, Nielzer; Toapanta-Yanchapaxi, Liz N; Aguirre Valadez, Jonathan; Espinola Zavaleta, Nilda; Muñoz-Martínez, Sergio G; García-Juárez, Ignacio

    Portopulmonary hypertension (PPH) is a rare condition worldwide, although epidemiological data are unknown in Mexico. However, chronic liver diseases are very prevalent in Mexico. PPH is the 4th subtype in frequency in the group of pulmonary arterial hypertension. Its diagnosis is made within 2 scenarios: patients with suspected pulmonary hypertension and candidates for orthotopic liver transplantation (OLT). Both echocardiogram and a right cardiac catheterisation are crucial for diagnosis in both cases. PPH is a challenge for OLT, since it can significantly increase perioperative mortality. The use of specific therapy is the cornerstone of this disease, as a measure to improve the outcome of those who become candidates for OLT with moderate to severe PPH. It is important to recognise that PPH can be a contraindication to OLT. The role of lung-liver transplantation or heart-lung-liver transplantation as a measure to heal pulmonary vascular disease in patients with PPH is still uncertain. Copyright © 2016 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.

  20. A Propagator Expansion Method for Solving Linearized Plasma Kinetic Equations with Collisions.

    DTIC Science & Technology

    1984-06-25

    of the collision frequency. For the linearized Balescu -Lenard collision * operator and for the zero-order distribution function Maxwellian, we obtain...Rev. 94:511. 3. Lenard, A. , and Bernstein, 1. 13. (1958) Phys. Rev. 112:1456. 4. Dougherty, J. P. (1964) Phys. Fluids 7:1788. 5. Balescu , R. (1960...long wavelength limit for the linearized Balescu - Lenard collision operator and for f0 Maxwellian. We obLain the total L damping rate 1 jry which is

  1. Percutaneous osteoplasty for the treatment of a painful osteochondral lesion of the talus: a case report and literature review.

    PubMed

    Seo, Sung-Suk; Park, Joo-Yeon; Kim, Hae-Jin; Yoon, Ji-Wook; Park, Sang-Hyun; Kim, Kyung-Hoon

    2012-01-01

    An osteochondral lesion of the talus (OLT) is a lesion involving the talar articular cartilage and its subchondral bone. OLT is a known cause of chronic ankle pain after ankle sprains in the active population. The lesion causes deep ankle pain associated with weight-bearing, impaired function, limited range of motion, stiffness, catching, locking, and swelling. There are 2 common patterns of OLTs. Anterolateral talar dome lesions result from inversion and dorsiflexion injuries of the ankle at the area impacting against the fibula. Posteromedial lesions result from inversion, plantar flexion, and external rotation injuries of the ankle at the area impacting against the tibial ceiling of the ankle joint. Early diagnosis of an OLT is particularly important because the tibiotalar joint is exposed to more compressive load per unit area than any other joint in the body. Failure of diagnosis can lead to the evolution of a small, stable lesion into a larger lesion or an unstable fragment, which can result in chronic pain, joint instability, and premature osteoarthritis. A 43-year-old man, with a history of ankle sprain one year previously, visited our pain clinic for continuous right ankle pain after walking or standing for more than 30 minutes. There was a focal tenderness on the posteromedial area of the right talus. Imaging studies revealed a posteromedial OLT classified as having a geode form according to the FOG (fractures, osteonecroses, geodes) radiological classification and categorized as a stage 2a lesion on magnetic resonance imaging. The patient was scheduled for aspiration and osteoplasty with hydroxyapatite under arthroscopic and fluoroscopic guidance. A 26-gauge needle was inserted to infiltrate local anesthetics into the skin over the cyst and ankle joint. An arthroscope was placed into the joint to approach the OLT. The arthroscopic view showed that there was no connection between the OLT and the cyst of the talus body. A 13-gauge bone biopsy needle was

  2. NOISECHECK Procedures for Measuring Noise Exposure from Aircraft Operations

    DTIC Science & Technology

    1980-11-01

    in § afterburner , 8 min € MIL PVR, 8 min 6 80« rpm, and 20 min « idle). Aircraft Maintenance and Runup Log Procedure 1. Log every maintenance...OoMirtnat OltUnct »it« Profilt & SEL utt Eq. l Stipolt- « tnt I Fro» lorkihttt 7 NOISEFILE Sa ♦ 4 SEL Sltnt OltUnct WtSEFlLE SEL Mrtrift

  3. Intraseasonal and Interannual Variability of Mars Present Climate

    NASA Astrophysics Data System (ADS)

    Hollingsworth, Jeffery L.; Bridger, Alison F. C.; Haberle, Robert M.

    1996-01-01

    This is a Final Report for a Joint Research Interchange (JRI) between NASA Ames Research Center and San Jose State University, Department of Meteorology. The focus of this JRI has been to investigate the nature of intraseasonal and interannual variability of Mars'present climate. We have applied a three-dimensional climate model based on the full hydrostatic primitive equations to determine the spatial, but primarily, the temporal structures of the planet's large-scale circulation as it evolves during a given seasonal advance, and, over multi-annual cycles. The particular climate model applies simplified physical parameterizations and is computationally efficient. It could thus easily be integrated in a perpetual season or advancing season configuration, as well as over many Mars years. We have assessed both high and low-frequency components of the circulation (i.e., motions having periods of Omicron(2-10 days) or greater than Omicron(10 days), respectively). Results from this investigation have explored the basic issue whether Mars' climate system is naturally 'chaotic' associated with nonlinear interactions of the large-scale circulation-regardless of any allowance for year-to-year variations in external forcing mechanisms. Titles of papers presented at scientific conferences and a manuscript to be submitted to the scientific literature are provided. An overview of a areas for further investigation is also presented.

  4. Urea cycle disorders: a case report of a successful treatment with liver transplant and a literature review.

    PubMed

    Foschi, Francesco Giuseppe; Morelli, Maria Cristina; Savini, Sara; Dall'Aglio, Anna Chiara; Lanzi, Arianna; Cescon, Matteo; Ercolani, Giorgio; Cucchetti, Alessandro; Pinna, Antonio Daniele; Stefanini, Giuseppe Francesco

    2015-04-07

    The urea cycle is the final pathway for nitrogen metabolism. Urea cycle disorders (UCDs) include a variety of genetic defects, which lead to inefficient urea synthesis. Elevated blood ammonium level is usually dominant in the clinical pattern and the primary manifestations affect the central nervous system. Herein, we report the case of a 17-year-old girl who was diagnosed with UCD at the age of 3. Despite a controlled diet, she was hospitalized several times for acute attacks with recurrent life risk. She came to our attention for a hyperammonemic episode. We proposed an orthotopic liver transplant (OLT) as a treatment; the patient and her family were in complete agreement. On February 28, 2007, she successfully received a transplant. Following the surgery, she has remained well, and she is currently leading a normal life. Usually for UCDs diet plays the primary therapeutic role, while OLT is often considered as a last resort. Our case report and the recent literature data on the quality of life and prognosis of traditionally treated patients vs OLT patients, support OLT as a primary intervention to prevent life-threatening acute episodes and chronic mental impairment.

  5. Epistaxis in end stage liver disease masquerading as severe upper gastrointestinal hemorrhage

    PubMed Central

    Camus, Marine; Jensen, Dennis M; Matthews, Jason D; Ohning, Gordon V; Kovacs, Thomas O; Jutabha, Rome; Ghassemi, Kevin A; Machicado, Gustavo A; Dulai, Gareth S

    2014-01-01

    AIM: To describe the prevalence, diagnosis, treatment, and outcomes of end stage liver disease (ESLD) patients with severe epistaxis thought to be severe upper gastrointestinal hemorrhage (UGIH). METHODS: This observational single center study included all consecutive patients with ESLD and epistaxis identified from consecutive subjects hospitalized with suspected UGIH and prospectively enrolled in our databases of severe UGIH between 1998 and 2011. RESULTS: A total of 1249 patients were registered for severe UGIH in the data basis, 461 (36.9%) were cirrhotics. Epistaxis rather than UGIH was the bleeding source in 20 patients. All patients had severe coagulopathy. Epistaxis was initially controlled in all cases. Fifteen (75%) subjects required posterior nasal packing and 2 (10%) embolization in addition to correction of coagulopathy. Five (25%) patients died in the hospital, 12 (60%) received orthotopic liver transplantation (OLT), and 3 (15%) were discharged without OLT. The mortality rate was 63% in patients without OLT. CONCLUSION: Severe epistaxis in patients with ESLD is (1) a diagnosis of exclusion that requires upper endoscopy to exclude severe UGIH; and (2) associated with a high mortality rate in patients not receiving OLT. PMID:25320538

  6. All-optical virtual private network system in OFDM based long-reach PON using RSOA re-modulation technique

    NASA Astrophysics Data System (ADS)

    Kim, Chang-Hun; Jung, Sang-Min; Kang, Su-Min; Han, Sang-Kook

    2015-01-01

    We propose an all-optical virtual private network (VPN) system in an orthogonal frequency division multiplexing (OFDM) based long reach PON (LR-PON). In the optical access network field, technologies based on fundamental upstream (U/S) and downstream (D/S) have been actively researched to accommodate explosion of data capacity. However, data transmission among the end users which is arisen from cloud computing, file-sharing and interactive game takes a large weight inside of internet traffic. Moreover, this traffic is predicted to increase more if Internet of Things (IoT) services are activated. In a conventional PON, VPN data is transmitted through ONU-OLT-ONU via U/S and D/S carriers. It leads to waste of bandwidth and energy due to O-E-O conversion in the OLT and round-trip propagation between OLT and remote node (RN). Also, it causes inevitable load to the OLT for electrical buffer, scheduling and routing. The network inefficiency becomes more critical in a LR-PON which has been researched as an effort to reduce CAPEX and OPEX through metro-access consolidation. In the proposed system, the VPN data is separated from conventional U/S and re-modulated on the D/S carrier by using RSOA in the ONUs to avoid bandwidth consumption of U/S and D/S unlike in previously reported system. Moreover, the transmitted VPN data is re-directed to the ONUs by wavelength selective reflector device in the RN without passing through the OLT. Experimental demonstration for the VPN communication system in an OFDM based LR-PON has been verified.

  7. Availability of anesthetic effect monitoring: utilization, intraoperative management and time to extubation in liver transplantation.

    PubMed

    Schumann, R; Hudcova, J; Bonney, I; Cepeda, M S

    2010-12-01

    Titration of volatile anesthetics to anesthetic effect monitoring using the bispectral index (BIS) has been shown to decrease anesthetic requirements and facilitate recovery from anesthesia unrelated to liver transplantation (OLT). To determine whether availability of such monitoring influences its utilization pattern and affect anesthetic care and outcomes in OLT, we conducted a retrospective analysis in recipients with and without such monitoring. We evaluated annual BIS utilization over a period of 7 years, and compared 41 BIS-monitored patients to 42 controls. All received an isoflurane/air/oxygen and opioid-based anesthetic with planned postoperative ventilation. Data collection included age, body mass index (BMI), gender, Model for End-stage Liver Disease (MELD) score, and time to extubation (TtE). Mean preanhepatic, anhepatic, and postanhepatic end-tidal isoflurane concentrations were compared, as well as BIS values for each phase of OLT using the Kruskal-Wallis and Wilcoxon signed-rank tests, respectively. The use of anesthetic effect monitoring when available increased steadily from 15% of cases in the first year to almost 93% by year 7. There was no significant difference in age, gender, BMI, MELD, or TtE between groups. The BIS group received less inhalational anesthetic during each phase of OLT compared to the control group. However, this difference was statistically significant only during the anhepatic phase (P = .026), and was clinically not impressive. Within the BIS group, the mean BIS value was 38.74 ± 5.25 (mean ± standard deviation), and there was no difference for the BIS value between different transplant phases. Availability of anesthetic effect monitoring as an optional monitoring tool during OLT results in its increasing utilization by anesthesia care teams over time. However, unless integrated into an intraoperative algorithm and an early extubation protocol for fast tracking of OLT recipients, this utilization does not appear to provide

  8. Serious gaming for orthotopic liver transplant anesthesiology: A randomized control trial.

    PubMed

    Katz, Daniel; Zerillo, Jeron; Kim, Sang; Hill, Bryan; Wang, Ryan; Goldberg, Andrew; DeMaria, Samuel

    2017-04-01

    Anesthetic management of orthotopic liver transplantation (OLT) is complex. Given the unequal distributions of liver transplant surgeries performed at different centers, anesthesiology providers receive relatively uneven OLT training and exposure. One well-suited modality for OLT training is the "serious game," an interactive application created for the purpose of imparting knowledge or skills, while leveraging the self-motivating elements of video games. We therefore developed a serious game designed to teach best practices for the anesthetic management of a standard OLT and determined if the game would improve resident performance in a simulated OLT. Forty-four residents on the liver transplant rotation were randomized to either the gaming group (GG) or the control group (CG) prior to their introductory simulation. Both groups were given access to the same educational materials and literature during their rotation, but the GG also had access to the OLT Trainer. Performance on the simulations were recorded on a standardized grading rubric. Both groups experienced an increase in score relative to baseline that was statistically significant at every stage. The improvements in scores were greater for the GG participants than the CG participants. Overall score improvement between the GG and CG (mean [standard deviation]) was statistically significant (GG, 7.95 [3.65]; CG, 4.8 [4.48]; P = 0.02), as were scores for preoperative assessment (GG, 2.67 [2.09]; CG, 1.17 [1.43]; P = 0.01) and anhepatic phase (GG, 1.62 [1.01]; CG, 0.75 [1.28]; P = 0.02). Of the residents with game access, 81% were "very satisfied" or "satisfied" with the game overall. In conclusion, adding a serious game to an existing educational curriculum for liver transplant anesthesia resulted in significant learning gains for rotating anesthesia residents. The intervention was straightforward to implement and cost-effective. Liver Transplantation 23 430-439 2017 AASLD. © 2017 by the American Association

  9. A simplified multivisceral transplantation procedure for patients with combined end-stage liver disease and type 2 diabetes mellitus.

    PubMed

    He, Xiao-Shun; Fu, Shun-Jun; Zhao, Qiang; Zhu, Xiao-Feng; Wang, Dong-Ping; Han, Ming; Ju, Wei-Qiang; Ma, Yi; Jiao, Xing-Yuan; Yuan, Xiao-Peng; Hu, An-Bin; Guo, Zhi-Yong

    2017-09-01

    In liver transplant patients with type 2 diabetes mellitus (DM), the disease worsens after transplantation because of longterm use of diabetogenic immunosuppressive drugs, making management of those patients a great challenge. The objective of our study was to evaluate the safety and efficacy of a simplified multivisceral transplantation (SMT) procedure for the treatment of patients with end-stage liver disease and concurrent type 2 DM. Forty-four patients who had pretransplant type 2 DM were included. A total of 23 patients received SMT, and 21 patients received orthotopic liver transplantation (OLT). Patient and graft survivals, complications, diabetic control, and quality of life (QOL) were retrospectively analyzed in both groups. The 1-, 3-, and 5-year cumulative patient and graft survival rates were 91.5%, 75.4%, and 75.4% in the SMT group and were 94.4%, 64.4%, and 64.4% in the OLT group, respectively (P = 0.70). Interestingly, 95.7% (22/23) of patients achieved complete remission from DM after SMT compared with 16.7% (3/18) of patients after OLT. The occurrence of biliary complication was significantly higher in the OLT group than that in the SMT group (23.8% versus 0.0%; P = 0.01). Moreover, better QOL was observed in the SMT group than that in the OLT group. In conclusion, the SMT procedure we described here is a safe and viable option for patients with end-stage live disease and concurrent type 2 DM. This SMT procedure offers excellent transplant outcomes and QOL. Liver Transplantation 23 1161-1170 2017 AASLD. © 2017 by the American Association for the Study of Liver Diseases.

  10. The safety and efficacy of ledipasvir/sofosbuvir with or without ribavirin in the treatment of orthotopic liver transplant recipients with recurrent hepatitis C: real-world data.

    PubMed

    Pyrsopoulos, Nikolaos; Trilianos, Panagiotis; Lingiah, Vivek A; Fung, Phoenix; Punnoose, Merlin

    2018-07-01

    Recurrent hepatitis C (RHC) in orthotopic liver transplantation (OLT) population is associated with accelerated rates of fibrosis, low efficacy and decreased tolerability with traditional therapies. The aim of this study was to evaluate the safety and efficacy of ledipasvir/sofosbuvir (LED/SOF) with or without ribavirin (RBV) in OLT patients with RHC. Patients at least 3 months post-OLT and with documented RHC were treated with LED/SOF with or without RBV for either 12 or 24 weeks. End-of-treatment and sustained virological response 12 weeks after the completion of treatment were documented. Patients were closely monitored for treatment-related adverse effects and the potential need for adjustment in their immunosuppression. Seventy-one patients were included in the study. Median age was 62 years. Median time from OLT was 55 months. Twenty-six (36.6%) patients were treatment-naive and 45 (63.4%) had previously failed interferon-based therapies. The majority of patients (57.7%) had stage F0-F2 fibrosis. Sixty-seven (94.3%) patients completed 12 weeks of LED/SOF with RBV, three patients completed 12 or 24 weeks of LED/SOF without RBV, and one patient completed only 8 weeks of LED/SOF without RBV owing to severe allograft dysfunction. Sustained virological response was near universal in our cohort (98.5%) regardless of genotype, fibrosis stage, and regimen or treatment duration. Most commonly reported side effects were malaise and gastrointestinal upset. No patient required adjustment in immunosuppression and no episodes of rejection were documented during treatment. The combination of LED/SOF with RBV for 12 weeks or LED/SOF for 24 weeks is very effective and safe in treating OLT recipients with RHC.

  11. Isoflurane: An Ideal Anesthetic for Rodent Orthotopic Liver Transplantation Surgery?

    PubMed

    Cao, D; Liu, Y; Li, J; Gong, J

    2016-10-01

    Because the choice of anesthetic affects the rodent orthotopic liver transplantation (OLT) model, we compared the effects of isoflurane, ketamine, chloral hydrate, and pentobarbital on the OLT model. OLT was performed using the two-cuff technique. Two hundred male rats were randomly divided into five groups: control, isoflurane, ketamine, chloral hydrate, and pentobarbital groups. Rectal temperatures, respiratory rates, arterial blood values (pH, PaCO 2 , PaO 2 , and SatO 2 ), liver function tests and histopathology, recovery times, and anhepatic stage mortality rates were assessed. Compared with controls, respiratory rates decreased by 20% in the isoflurane group, and decreased by 40%-50% in the ketamine, chloral hydrate, and pentobarbital groups. The PaO 2 , SatO 2 , and pH levels in the ketamine, chloral hydrate, and pentobarbital groups were significantly lower than those in the isoflurane and control groups (P < .05). Only the pentobarbital group displayed significant liver histopathologic changes along with significantly higher levels of serum alanine aminotransferase and total bilirubin, but a significantly lower level of serum albumin, compared with the control group (P < .05). The isoflurane group had a 0% anhepatic stage mortality rate compared with rates of 30%-40% in the other anesthetic groups. Isoflurane should be the preferred anesthetic for rodent OLT surgery due to its minimal respiratory and hepatic physiological effects as well as its low anhepatic phase mortality rate. Secondary to isoflurane, ketamine and chloral hydrate may be administered as donor anesthetics. Pentobarbital use should be avoided entirely in rodent OLT surgery due to its significant hepatotoxic effects. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Recurrent Primary Biliary Cirrhosis: Peritransplant Factors and Ursodeoxycholic Acid Treatment Post-Liver Transplant

    PubMed Central

    Guy, Jennifer E.; Qian, Peiqing; Lowell, Jeffrey A.; Peters, Marion G.

    2014-01-01

    Primary biliary cirrhosis (PBC) recurs after orthotopic liver transplantation (OLT) in up to one-third of patients. These patients are typically asymptomatic, can be identified by abnormal liver biochemistries, and have evidence of histologic recurrence on liver biopsy. The effect of treatment on recurrence has not been determined. This pilot study evaluates the factors associated with recurrent PBC and describes our experience using ursodeoxycholic acid treatment in this patient population. Forty-eight patients with PBC were followed for at least 1 yr post-OLT, and 27 patients (56%) developed abnormal serum alkaline phosphatase. Seventeen patients (35%) had evidence of recurrent PBC by liver biopsy. Patients with recurrent PBC had a trend toward longer warm ischemia times and more episodes of acute cellular rejection in the first year posttransplant, but this was not significant in multivariate analysis. Donor or recipient age, donor and recipient cytomegalovirus status, and dose of immunosuppression did not correlate with recurrence of PBC. Those patients diagnosed with recurrent PBC were placed on ursodeoxycholic acid, 15 mg/kg daily, with improvement in serum alkaline phosphatase in the majority. In conclusion, recurrent PBC is not infrequent post-OLT, and ursodeoxycholic acid can be used with some benefit post-OLT. Treatment effects on long-term survival are not known. PMID:16184542

  13. A comparison of operation, endoscopic retrograde cholangiopancreatography, and percutaneous transhepatic cholangiography in biliary complications after hepatic transplantation.

    PubMed

    Kuo, P C; Lewis, W D; Stokes, K; Pleskow, D; Simpson, M A; Jenkins, R L

    1994-08-01

    Biliary complications (BC) remain a significant cause of morbidity and mortality after orthotopic liver transplantation (OLT). In an effort to determine the incidence of BC after OLT and the success of management options, 157 hepatic transplants performed from January 1987 to July 1991 were reviewed. The incidence of BC was 25 percent, with a one year mortality rate of 43.5 percent compared with 23.4 percent for patients in a control group (p < 0.05). Most BC occurring before postoperative day 30 presented as leaks, with a one year mortality rate of 50 percent (p < 0.03 versus control group). Biliary complications presenting after postoperative day 30 presented as strictures, with a one year mortality rate of 36.8 percent (p = NS versus control group). Endoscopic retrograde cholangiopancreatography (ERCP), percutaneous transhepatic cholangiography (PTHC), and operative treatment were analyzed to determine relative patency rates after intervention for BC. The analysis showed that ERCP and PTHC were equivalent, with a one year patency rate of 45 percent. Operative treatment had a patency rate of 89 percent (p < 0.05 compared to ERCP and PTHC). The results from ERCP and PTHC may be useful for delineation of rejection versus BC after OLT. However, operative treatment is significantly more effective for definitive treatment of BC after OLT.

  14. Traffic-aware energy saving scheme with modularization supporting in TWDM-PON

    NASA Astrophysics Data System (ADS)

    Xiong, Yu; Sun, Peng; Liu, Chuanbo; Guan, Jianjun

    2017-01-01

    Time and wavelength division multiplexed passive optical network (TWDM-PON) is considered to be a primary solution for next-generation passive optical network stage 2 (NG-PON2). Due to the feature of multi-wavelength transmission of TWDM-PON, some of the transmitters/receivers at the optical line terminal (OLT) could be shut down to reduce the energy consumption. Therefore, a novel scheme called traffic-aware energy saving scheme with modularization supporting is proposed. Through establishing the modular energy consumption model of OLT, the wavelength transmitters/receivers at OLT could be switched on or shut down adaptively depending on sensing the status of network traffic load, thus the energy consumption of OLT will be effectively reduced. Furthermore, exploring the technology of optical network unit (ONU) modularization, each module of ONU could be switched to sleep or active mode independently in order to reduce the energy consumption of ONU. Simultaneously, the polling sequence of ONU could be changed dynamically via sensing the packet arrival time. In order to guarantee the delay performance of network traffic, the sub-cycle division strategy is designed to transmit the real-time traffic preferentially. Finally, simulation results verify that the proposed scheme is able to reduce the energy consumption of the network while maintaining the traffic delay performance.

  15. Feature-space-based FMRI analysis using the optimal linear transformation.

    PubMed

    Sun, Fengrong; Morris, Drew; Lee, Wayne; Taylor, Margot J; Mills, Travis; Babyn, Paul S

    2010-09-01

    The optimal linear transformation (OLT), an image analysis technique of feature space, was first presented in the field of MRI. This paper proposes a method of extending OLT from MRI to functional MRI (fMRI) to improve the activation-detection performance over conventional approaches of fMRI analysis. In this method, first, ideal hemodynamic response time series for different stimuli were generated by convolving the theoretical hemodynamic response model with the stimulus timing. Second, constructing hypothetical signature vectors for different activity patterns of interest by virtue of the ideal hemodynamic responses, OLT was used to extract features of fMRI data. The resultant feature space had particular geometric clustering properties. It was then classified into different groups, each pertaining to an activity pattern of interest; the applied signature vector for each group was obtained by averaging. Third, using the applied signature vectors, OLT was applied again to generate fMRI composite images with high SNRs for the desired activity patterns. Simulations and a blocked fMRI experiment were employed for the method to be verified and compared with the general linear model (GLM)-based analysis. The simulation studies and the experimental results indicated the superiority of the proposed method over the GLM-based analysis in detecting brain activities.

  16. Are drowned donors marginal donors? A single pediatric center experience.

    PubMed

    Kumm, Kayla R; Galván, N Thao N; Koohmaraie, Sarah; Rana, Abbas; Kueht, Michael; Baugh, Katherine; Hao, Liu; Yoeli, Dor; Cotton, Ronald; O'Mahony, Christine A; Goss, John A

    2017-09-01

    Drowning, a common cause of death in the pediatric population, is a potentially large donor pool for OLT. Anecdotally, transplant centers have deemed these organs high risk over concerns for infection and graft dysfunction. We theorized drowned donor liver allografts do not portend worse outcomes and therefore should not be excluded from the donation pool. We reviewed our single-center experience of pediatric OLTs between 1988 and 2015 and identified 33 drowned donor recipients. These OLTs were matched 1:2 to head trauma donor OLTs from our center. A chart review assessed postoperative peak AST and ALT, incidence of HAT, graft and recipient survival. Recipient survival at one year between patients with drowned donor vs head trauma donor allografts was not statistically significant (94% vs 97%, P=.63). HAT incidence was 6.1% in the drowned donor group vs 7.6% in the control group (P=.78). Mean postoperative peak AST and ALT was 683 U/L and 450 U/L for drowned donors vs 1119 U/L and 828 U/L in the matched cohort. These results suggest drowned donor liver allografts do not portend worse outcomes in comparison with those procured from head trauma donors. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Does an injection of a stromal vascular fraction containing adipose-derived mesenchymal stem cells influence the outcomes of marrow stimulation in osteochondral lesions of the talus? A clinical and magnetic resonance imaging study.

    PubMed

    Kim, Yong Sang; Lee, Ho Jin; Choi, Yun Jin; Kim, Yong Il; Koh, Yong Gon

    2014-10-01

    Marrow stimulation for the treatment of osteochondral lesions of the talus (OLTs) is controversial in patients with poor prognostic factors of OLTs. Currently, mesenchymal stem cells (MSCs) are expected to biologically augment the treatment of OLTs. To compare the clinical and magnetic resonance imaging (MRI) outcomes between an injection of MSCs with marrow stimulation and marrow stimulation alone in patients with OLTs. Cohort study; Level of evidence, 3. A total of 49 patients (50 ankles) with OLTs underwent follow-up MRI after arthroscopic treatment. Among these 50 ankles, 26 underwent marrow stimulation alone (conventional group), and 24 underwent marrow stimulation with an injection of a stromal vascular fraction (SVF) containing MSCs (MSC group). Clinical outcomes were evaluated according to the visual analog scale (VAS) for pain, American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale, and Tegner activity scale. The magnetic resonance observation of cartilage repair tissue (MOCART) score was used for the MRI evaluation of repaired lesions. The mean VAS score, AOFAS score, and Tegner score improved from 7.1 ± 1.2, 68.5 ± 5.6, and 3.4 ± 0.6 to 3.9 ± 0.8, 78.3 ± 4.9, and 3.5 ± 0.8, respectively, in the conventional group and from 7.1 ± 0.8, 67.7 ± 4.7, and 3.4 ± 0.5 to 3.2 ± 0.8, 83.3 ± 7.0, and 3.9 ± 0.7, respectively, in the MSC group. All clinical outcomes, including the VAS, AOFAS, and Tegner scores, improved significantly in the MSC group compared with the conventional group (P = .003, .009, and .041, respectively). There was a significant difference (P = .037) in the mean MOCART score between the conventional and MSC groups (49.4 ± 16.6 vs 62.1 ± 21.8, respectively), and significant correlations of the MOCART score with clinical outcomes were found in both groups (P < .05). Patient age (≥46.1 years), large lesion size (≥151.2 mm(2)), and the presence of subchondral cysts were associated with a worse MOCART score in the

  18. Metallurgical Examination of a Cast Turret Manufactured by the American Steel Foundries

    DTIC Science & Technology

    1945-03-28

    ferrite and a structure stmlar to tempered bainite tnd fine carb ides. 4. The results of this investigatio l inCicate that the American Steel Foundries...1hirrot No 11Mufac t~redj~ t!Le American~ Steel Poidcries J.J Wil jr;I 4?1 ’JJ No. B171; 11000 Picral Structure simuilar to temnpered bainite Lavsociated wita fine carbides and ferrite patcha.. FIGM I ...examination has been conducted on two samples of the. cast turret to. 3171 for the Hedium Tank II4, maiufactured by the i.meriaan Steel Foundries, which

  19. Piggyback technique in adult orthotopic liver transplantation: an analysis of 1067 liver transplants at a single center

    PubMed Central

    Nakamura, Noboru; Vaidya, Anil; Levi, David M.; Kato, Tomoaki; Nery, Jose R.; Madariaga, Juan R.; Molina, Enrique; Ruiz, Phillip; Gyamfi, Anthony; Tzakis, Andreas G.

    2006-01-01

    Background. Orthotopic liver transplantation (OLT) in adult patients has traditionally been performed using conventional caval reconstruction technique (CV) with veno-venous bypass. Recently, the piggyback technique (PB) without veno-venous bypass has begun to be widely used. The aim of this study was to assess the effect of routine use of PB on OLTs in adult patients. Patients and methods. A retrospective analysis was undertaken of 1067 orthotopic cadaveric whole liver transplantations in adult patients treated between June 1994 and July 2001. PB was used as the routine procedure. Patient demographics, factors including cold ischemia time (CIT), warm ischemia time (WIT), operative time, transfusions, blood loss, and postoperative results were assessed. The effects of clinical factors on graft survival were assessed by univariate and multivariate analyses.In all, 918 transplantations (86%) were performed with PB. Blood transfusion, WIT, and usage of veno-venous bypass were less with PB. Seventy-five (8.3%) cases with PB had refractory ascites following OLT (p=NS). Five venous outflow stenosis cases (0.54%) with PB were noted (p=NS). The liver and renal function during the postoperative periods was similar. Overall 1-, 3-, and 5-year patient survival rates were 85%, 78%, and 72% with PB. Univariate analysis showed that cava reconstruction method, CIT, WIT, amount of transfusion, length of hospital stay, donor age, and tumor presence were significant factors influencing graft survival. Multivariate analysis further reinforced the fact that CIT, donor age, amount of transfusion, and hospital stay were prognostic factors for graft survival. Conclusions. PB can be performed safely in the majority of adult OLTs. Results of OLT with PB are as same as for CV. Liver function, renal function, morbidity, mortality, and patient and graft survival are similar to CV. However, amount of transfusion, WIT, and use of veno-venous bypass are less with PB. PMID:18333273

  20. The effect of prior upper abdominal surgery on outcomes after liver transplantation for hepatocellular carcinoma: An analysis of the database of the organ procurement transplant network.

    PubMed

    Silva, Jack P; Berger, Nicholas G; Yin, Ziyan; Liu, Ying; Tsai, Susan; Christians, Kathleen K; Clarke, Callisia N; Mogal, Harveshp; Gamblin, T Clark

    2018-05-01

    Orthotopic liver transplantation (OLT) is the preferred treatment for hepatocellular carcinoma (HCC) in select patients. Many patients listed for OLT have a history of prior upper abdominal surgery (UAS). Repeat abdominal surgery increases operative complexity and may cause a greater incidence of complication. This study sought to compare outcomes after liver transplantation for patients with and without prior UAS. Adult HCC patients undergoing OLT were identified using the database from the Organ Procurement and Transplantation Network (1987-2015). Patients were separated by presence of prior UAS into 2 propensity-matched cohorts. Overall survival (OS) and graft survival (GS) were analyzed by log-rank test and graphed using Kaplan-Meier method. Recipient and donor demographic and clinical characteristics were also studied using Cox regression models. A total of 15,043 patients were identified, of whom 6,205 had prior UAS (41.2%). After 1:1 propensity score matching, cohorts (UAS versus no UAS) contained 4,669 patients. UAS patients experienced shorter GS (122 months vs 129 months; P < .001) and shorter OS (130 months vs 141 months; P < .001). Median duration of stay for both cohorts was 8 days. Multivariate Cox regression models revealed that prior UAS was associated with an increased hazard ratio (HR) for GS (HR 1.14; 95% confidence interval (CI) 1.06-1.22; P < .001) and OS (HR 1.14; 95% CI 1.06-1.23; P < .001). Prior UAS is an independent negative predictor of GS and OS after OLT for HCC. OLT performed in patients with UAS remains a well-tolerated and effective treatment for select HCC patients but may alter expected outcomes and influence follow-up protocols. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Role of Stereotactic Body Radiation Therapy Before Orthotopic Liver Transplantation: Retrospective Evaluation of Pathologic Response and Outcomes

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

    Mannina, Edward Michael, E-mail: emmannina@gmail.com; Cardenes, Higinia Rosa; Lasley, Foster D.

    Purpose: To analyze the results of stereotactic body radiation therapy (SBRT) in patients with early-stage, localized hepatocellular carcinoma who underwent definitive orthotopic liver transplantation (OLT). Methods and Materials: The subjects of this retrospective report are 38 patients diagnosed with hepatocellular carcinoma who underwent SBRT per institutional phase 1 to 2 eligibility criteria, before definitive OLT. Pre-OLT radiographs were compared with pathologic gold standard. Analysis of treatment failures and deaths was undertaken. Results: With median follow-up of 4.8 years from OLT, 9 of 38 patients (24%) recurred, whereas 10 of 38 patients (26%) died. Kaplan-Meier estimates of 3-year overall survival and disease-free survivalmore » are 77% and 74%, respectively. Sum longest dimension of tumors was significantly associated with disease-free survival (hazard ratio 1.93, P=.026). Pathologic response rate (complete plus partial response) was 68%. Radiographic scoring criteria performed poorly; modified Response Evaluation Criteria in Solid Tumors produced highest concordance (κ = 0.224). Explants revealed viable tumor in 74% of evaluable patients. Treatment failures had statistically larger sum longest dimension of tumors (4.0 cm vs 2.8 cm, P=.014) and non–statistically significant higher rates of lymphovascular space invasion (44% vs 17%), cT2 disease (44% vs 21%), ≥pT2 disease (67% vs 34%), multifocal tumors at time of SBRT (44% vs 21%), and less robust mean α-fetoprotein response (−25 IU/mL vs −162 IU/mL). Conclusions: Stereotactic body radiation therapy before to OLT is a well-tolerated treatment providing 68% pathologic response, though 74% of explants ultimately contained viable tumor. Radiographic response criteria poorly approximate pathology. Our data suggest further stratification of patients according to initial disease burden and treatment response.« less

  2. Using old liver grafts for liver transplantation: where are the limits?

    PubMed

    Jiménez-Romero, Carlos; Caso Maestro, Oscar; Cambra Molero, Félix; Justo Alonso, Iago; Alegre Torrado, Cristina; Manrique Municio, Alejandro; Calvo Pulido, Jorge; Loinaz Segurola, Carmelo; Moreno González, Enrique

    2014-08-21

    The scarcity of ideal liver grafts for orthotopic liver transplantation (OLT) has led transplant teams to investigate other sources of grafts in order to augment the donor liver pool. One way to get more liver grafts is to use marginal donors, a not well-defined group which includes mainly donors > 60 years, donors with hypernatremia or macrosteatosis > 30%, donors with hepatitis C virus or hepatitis B virus positive serologies, cold ischemia time > 12 h, non-heart-beating donors, and grafts from split-livers or living-related donations. Perhaps the most practical and frequent measure to increase the liver pool, and thus to reduce waiting list mortality, is to use older livers. In the past years the results of OLT with old livers have improved, mainly due to better selection and maintenance of donors, improvements in surgical techniques in donors and recipients, and intra- and post-OLT management. At the present time, sexagenarian livers are generally accepted, but there still exists some controversy regarding the use of septuagenarian and octogenarian liver grafts. The aim of this paper is to briefly review the aging process of the liver and reported experiences using old livers for OLT. Fundamentally, the series of septuagenarian and octogenarian livers will be addressed to see if there is a limit to using these aged grafts.

  3. Using old liver grafts for liver transplantation: Where are the limits?

    PubMed Central

    Jiménez-Romero, Carlos; Caso Maestro, Oscar; Cambra Molero, Félix; Justo Alonso, Iago; Alegre Torrado, Cristina; Manrique Municio, Alejandro; Calvo Pulido, Jorge; Loinaz Segurola, Carmelo; Moreno González, Enrique

    2014-01-01

    The scarcity of ideal liver grafts for orthotopic liver transplantation (OLT) has led transplant teams to investigate other sources of grafts in order to augment the donor liver pool. One way to get more liver grafts is to use marginal donors, a not well-defined group which includes mainly donors > 60 years, donors with hypernatremia or macrosteatosis > 30%, donors with hepatitis C virus or hepatitis B virus positive serologies, cold ischemia time > 12 h, non-heart-beating donors, and grafts from split-livers or living-related donations. Perhaps the most practical and frequent measure to increase the liver pool, and thus to reduce waiting list mortality, is to use older livers. In the past years the results of OLT with old livers have improved, mainly due to better selection and maintenance of donors, improvements in surgical techniques in donors and recipients, and intra- and post-OLT management. At the present time, sexagenarian livers are generally accepted, but there still exists some controversy regarding the use of septuagenarian and octogenarian liver grafts. The aim of this paper is to briefly review the aging process of the liver and reported experiences using old livers for OLT. Fundamentally, the series of septuagenarian and octogenarian livers will be addressed to see if there is a limit to using these aged grafts. PMID:25152573

  4. Perioperative management in orthotopic liver transplantation: results of an Italian national survey.

    PubMed

    Biancofiore, G; Della Rocca, G

    2012-06-01

    No data are available on the perioperative approach during orthotopic liver transplantation (OLT) in Italy, apart from sporadically single center studies. The Department of Anesthesia cooperating with each Italian licensed OLT center received a questionnaire regarding preoperative evaluation, intraoperative anesthesia management, anesthetic drugs, blood components therapy, perioperative monitoring, supportive therapies, postoperative care, staff and organization. Twenty-two centers were surveyed and 17 returned the questionnaire. Center specific protocols for OLT anesthesia exist in 12 centers. Balanced anesthesia (volatile anesthetic agents and continuous infusion of opioids) is the standard anesthetic method. In 14 cases a thromboelastogram is available; one center reported not to have a rapid infusion device available. Pulmonary artery catheterization with a continuous cardiac output device is the most used hemodynamic monitoring system; in case of hemodynamic instability, the combination of dopamine/noradrenaline resulted the first choice before vascular clamping whereas noradrenaline alone after graft's reperfusion. No difference about which intraoperative phase is mostly characterized by the use of blood components was reported. Postoperative care is provided on anesthesiological-guided Intensive Care Units (ICU) in all the surveyed centers and in three centers the ICU is dedicated only to transplant patients. The results of this survey show that in Italy the perioperative management of patients undergoing OLT is not homogeneous. This database allows to debate on the best practices and pathways for perioperative management of these patients, and to stimulate future clinical trials aimed to assess the different component and steps forwards of the whole process.

  5. Epsilon-aminocaproic acid improves postrecirculation hemodynamics by reducing intraliver activated protein C consumption in orthotopic liver transplantation.

    PubMed

    Kong, H Y; Wen, X H; Huang, S Q; Zhu, S M

    2014-01-01

    Activated protein C (APC) is related to regulating the inflammatory response and hemodynamic stability upon reperfusion in cardiac operations and orthotopic liver transplantation (OLT). Epsilon-aminocaproic acid (EACA) is frequently used to treat fibrinolysis during OLT. It also has inhibitory effects related to the inflammatory response. However, it remains to be determined whether EACA can attenuate intraliver APC consumption and improve hemodynamic stability after reperfusion during OLT. Fifty-nine recipients were randomized to receive either EACA (150 mg kg(-1) given intravenously prior to incision, followed by 15 mg kg(-1) h(-1) infusion until 2 h after the graft reperfusion) or the same volume of saline. Blood samples to assess plasma APC and protein C were obtained immediately before and after reperfusion from the inferior caval effluent or the portal veins for calculation of transliver differences (Δ). Hemodynamics and vasoactive medication use during the reperfusion period were observed in both groups. No transhepatic changes in protein C were found in either group. Immediately after reperfusion, a marked intraliver consumption of APC was noted in all recipients (P < 0.001), and intraliver consumption of APC in the control group was greater than that in the EACA-treated group (P < 0.05). Fewer requirements for vasoactive medication use after reperfusion and better initial graft function were noted in the EACA-treated group (P < 0.05). EACA can attenuate intraliver APC consumption and improve hemodynamic stability after reperfusion and initial graft function during OLT.

  6. Congestion estimation technique in the optical network unit registration process.

    PubMed

    Kim, Geunyong; Yoo, Hark; Lee, Dongsoo; Kim, Youngsun; Lim, Hyuk

    2016-07-01

    We present a congestion estimation technique (CET) to estimate the optical network unit (ONU) registration success ratio for the ONU registration process in passive optical networks. An optical line terminal (OLT) estimates the number of collided ONUs via the proposed scheme during the serial number state. The OLT can obtain congestion level among ONUs to be registered such that this information may be exploited to change the size of a quiet window to decrease the collision probability. We verified the efficiency of the proposed method through simulation and experimental results.

  7. Applying psychological theories to evidence-based clinical practice: identifying factors predictive of placing preventive fissure sealants.

    PubMed

    Bonetti, Debbie; Johnston, Marie; Clarkson, Jan E; Grimshaw, Jeremy; Pitts, Nigel B; Eccles, Martin; Steen, Nick; Thomas, Ruth; Maclennan, Graeme; Glidewell, Liz; Walker, Anne

    2010-04-08

    Psychological models are used to understand and predict behaviour in a wide range of settings, but have not been consistently applied to health professional behaviours, and the contribution of differing theories is not clear. This study explored the usefulness of a range of models to predict an evidence-based behaviour -- the placing of fissure sealants. Measures were collected by postal questionnaire from a random sample of general dental practitioners (GDPs) in Scotland. Outcomes were behavioural simulation (scenario decision-making), and behavioural intention. Predictor variables were from the Theory of Planned Behaviour (TPB), Social Cognitive Theory (SCT), Common Sense Self-regulation Model (CS-SRM), Operant Learning Theory (OLT), Implementation Intention (II), Stage Model, and knowledge (a non-theoretical construct). Multiple regression analysis was used to examine the predictive value of each theoretical model individually. Significant constructs from all theories were then entered into a 'cross theory' stepwise regression analysis to investigate their combined predictive value. Behavioural simulation - theory level variance explained was: TPB 31%; SCT 29%; II 7%; OLT 30%. Neither CS-SRM nor stage explained significant variance. In the cross theory analysis, habit (OLT), timeline acute (CS-SRM), and outcome expectancy (SCT) entered the equation, together explaining 38% of the variance. Behavioural intention - theory level variance explained was: TPB 30%; SCT 24%; OLT 58%, CS-SRM 27%. GDPs in the action stage had significantly higher intention to place fissure sealants. In the cross theory analysis, habit (OLT) and attitude (TPB) entered the equation, together explaining 68% of the variance in intention. The study provides evidence that psychological models can be useful in understanding and predicting clinical behaviour. Taking a theory-based approach enables the creation of a replicable methodology for identifying factors that may predict clinical behaviour

  8. Predicting the discharge status after liver transplantation at a single center: a new approach for a new era.

    PubMed

    Kelly, Dympna M; Bennett, Renee; Brown, Nancy; McCoy, Judy; Boerner, Derek; Yu, Changhong; Eghtesad, Bijan; Barsoum, Wael; Fung, John J; Kattan, Michael W

    2012-07-01

    The aim of this study was to develop a tool for preoperatively predicting the need of a patient to attend an extended care facility after orthotopic liver transplantation (OLT). A multidisciplinary group, which included 2 transplant surgeons, 2 transplant nurses, 1 nurse manager, 2 physical therapists, 1 case manager, 1 home health care professional, 1 rehabilitation physician, and 1 statistician, met to identify preoperative factors relevant to discharge planning. The parameters that were examined as potential predictors of the discharge status were as follows: age, sex, language, Karnofsky score, OLT alone (versus a combined procedure), creatinine, bilirubin, international normalized ratio (INR), albumin, body mass index (BMI), Child-Turcotte-Pugh score, chemical Model for End-Stage Liver Disease score, renal dialysis, location before transplantation, comorbidities (encephalopathy, ascites, hydrothorax, and hepatopulmonary syndrome), diabetes mellitus (DM), cardiac ejection fraction and right ventricular systolic pressure, sex and availability of the primary caregiver, donor risk index, and donor characteristics. Between January 2004 and April 2010, 730 of 777 patients (94%) underwent only liver transplantation, and 47 patients (6%) underwent combined procedures. Five hundred nineteen patients (67%) were discharged home, 215 (28%) were discharged to a facility, and 43 (6%) died early after OLT. A multivariate logistic regression analysis identified the following parameters as significantly influencing the discharge status: a low Karnofsky score, an older age, female sex, an INR of 2.0, a creatinine level of 2.0 mg/dL, DM, a high bilirubin level, a low albumin level, a low or high BMI, and renal dialysis before OLT. The nomogram was prospectively validated with a population of 126 OLT recipients with a concordance index of 0.813. In conclusion, a new approach to improving the efficiency of hospital care is essential. We believe that this tool will aid in reducing

  9. N-acetylcysteine induces shedding of selectins from liver and intestine during orthotopic liver transplantation

    PubMed Central

    Taut, F J H; Schmidt, H; Zapletal, C M; Thies, J C; Grube, C; Motsch, J; Klar, E; Martin, E

    2001-01-01

    In orthotopic liver transplantation (OLT), N-acetylcysteine (NAC) reduces ischaemia/reperfusion (I/R) injury, improves liver synthesis function and prevents primary nonfunction of the graft. To further elucidate the mechanisms of these beneficial effects of NAC, we investigated influence of high-dose NAC therapy on the pattern of adhesion molecule release from liver and intestine during OLT. Nine patients receiving allograft OLT were treated with 150 mg NAC/kg during the first hour after reperfusion; 10 patients received the carrier only. One hour after reperfusion, samples of arterial, portal venous and hepatic venous plasma were taken and blood flow in the hepatic artery and the portal vein was measured. Absolute concentrations of sICAM-1, sVCAM-1, sP-selectin and sE-selectin were not markedly different. However, balance calculations showed release of selectins from NAC-treated livers as opposed to net uptake in controls (P ≤ 0·02 for sP-selectin). This shedding of selectins might be a contributing factor to the decrease in leucocyte adherence and improved haemodynamics found experimentally with NAC-treatment. PMID:11422213

  10. An investigation of noise performance in optical lock-in thermography

    NASA Astrophysics Data System (ADS)

    Rajic, Nik; Antolis, Cedric

    2017-12-01

    An investigation into the noise performance of optical lock-in thermography (OLT) is described. The study aims to clarify the influence of infrared detector type and key inspection parameters such as illumination strength and lock-in duration on the quality of OLT amplitude and phase imagery. The study compares the performance of a state-of-the-art cooled photon detector with several lower-cost microbolometers. The results reveal a significant noise performance advantage to the photon detector. Under certain inspection regimes the advantage with respect to phase image quality is disproportionately high relative to detector sensitivities. This is shown to result from an explicit dependence in the phase signal variance on the ratio between the signal amplitude and the detector sensitivity. While this finding supports the preferred use of photon detectors for OLT inspections, it does not exclude microbolometers from a useful role. In cases where the significantly lower capital cost and improved practicality of microbolometers provide an advantage it is shown that performance shortfalls can be overcome with a relatively small factorial increase in optical illumination intensity.

  11. Cardio-hepatic risk assessment by CMR imaging in liver transplant candidates.

    PubMed

    Reddy, Sahadev T; Thai, Ngoc L; Oliva, Jose; Tom, Kusum B; Dishart, Michael K; Doyle, Mark; Yamrozik, June A; Williams, Ronald B; Shah, Moneal; Wani, Adil; Singh, Anil; Maheswary, Rishi; Biederman, Robert W W

    2018-03-02

    The preoperative workup of orthotopic liver transplantation (OLT) patients is practically complex given the need for multiple imaging modalities. We recently demonstrated in our proof-of-concept study the value of a one-stop-shop approach using cardiovascular MRI (CMR) to address this complex problem. However, this approach requires further validation in a larger cohort, as detection of hepatocellular carcinoma (HCC) as well as cardiovascular risk assessment is critically important in these patients. We hypothesized that coronary risk assessment and HCC detectability is acceptable using the one-stop-shop CMR approach. In this observational study, patients underwent CMRI evaluation including cardiac function, stress CMR, thoracoabdominal MRA, and abdominal MRI on a standard MRI scanner in one examination. Over 8 years, 252 OLT candidates underwent evaluation in the cardiac MRI suit. The completion rates for each segment of the CMR examination were 99% for function, 95% completed stress CMR, 93% completed LGE for viability, 85% for liver MRI, and 87% for MRA. A negative CMR stress examination had 100% CAD event-free survival at 12 months. A total of 63 (29%) patients proceeded to OLT. Explant pathology confirmed detection/exclusion of HCC. This study further defines the population suitable for the one-stop-shop CMR concept for preop evaluation of OLT candidates providing a road map for integrated testing in this complex patient population for evaluation of cardiac risk and detection of HCC lesions. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Changes in the Concentrations of Mediators of Inflammation and Oxidative Stress in Exhaled Breath Condensate During Liver Transplantation and Their Relations With Postoperative ARDS.

    PubMed

    Liu, Dezhao; Luo, Gangjian; Luo, Chenfang; Wang, Tao; Sun, Guoliang; Hei, Ziqing

    2015-05-01

    Oxidative stress and inflammatory responses are thought to be involved in the pathogenesis of ARDS, which is one of the most serious complications of orthotopic liver transplantation (OLT). The collection of exhaled breath condensate (EBC) is a noninvasive method for obtaining clinical samples from the lungs. However, the changes of mediators of inflammation and oxidative stress in EBC remain unclear. Therefore, the aim of this study was to investigate the changes of mediators in EBC from OLT subjects and the relations between these mediators and ARDS. The levels of mediators of oxidative stress (superoxide dismutase [SOD], malondialdehyde [MDA], H2O2, NO, and 8-iso-prostaglandin F2α) and of inflammatory factors (tumor necrosis factor-α[TNF-α], interleukin [IL]-8, and IL-10) were measured in EBC and serum samples collected from 28 subjects before OLT surgery and at 2 and 4 h after the anhepatic phase. The diagnostic value for ARDS until the 3 days following transplantation was evaluated. Eighteen subjects developed ARDS after OLT. The concentrations of TNF-α, IL-8, MDA, NO, H2O2, and 8-iso-prostaglandin F2α were much higher in the ARDS group than in the control group, whereas the levels of IL-10 and SOD were lower in the ARDS group than in the control group. The serum levels of mediators of oxidative stress or inflammation were closely related to EBC levels. Receiver operating characteristic analysis showed that areas under the curves for MDA, NO, H2O2, 8-iso-prostaglandin F2α, TNF-α, IL-8, SOD, and IL-10 were 0.88, 0.88, 0.78, 0.84, 0.84, 0.94, 0.81, and 0.84 at 2 h after graft reperfusion and 0.98, 0.88, 0.92, 0.79, 0.95, 0.83, 0.88, and 0.97 at 4 h after graft reperfusion. EBC analysis is a noninvasive method for detecting mediators of inflammation and oxidative stress from the lungs. This method could be used to predict the higher incidence of ARDS induced by OLT. Copyright © 2015 by Daedalus Enterprises.

  13. Predictive Value of Serum Creatinine, Blood Urea Nitrogen, Uric Acid, and β2-Microglobulin in the Evaluation of Acute Kidney Injury after Orthotopic Liver Transplantation.

    PubMed

    Lu, Hai-Yang; Ning, Xin-Yu; Chen, Ying-Qi; Han, Shu-Jun; Chi, Ping; Zhu, Sai-Nan; Yue, Yun

    2018-05-05

    As a major complication after orthotopic liver transplantation (OLT), the occurrence of acute kidney injury (AKI) is frequently defined by serum creatinine (Cr); however, the accuracy of commonly used blood urea nitrogen (BUN), uric acid (UA), and β 2 -microglobulin (β 2 -MG) remains to be explored. This retrospective study compared the accuracy of these parameters for post-OLT AKI evaluation. Patients who underwent OLT in three centers between July 2003 and December 2013 were enrolled. The postoperative AKI group was diagnosed by the Kidney Disease Improving Global Outcomes (KDIGO) criteria and classified by stage. Measurement data were analyzed using the t-test or Wilcoxon rank-sum test; enumerated data were analyzed using the Chi-square test or Fisher's exact test. Diagnostic reliability and predictive accuracy were evaluated using receiver operating characteristic (ROC) curve analysis. This study excluded 976 cases and analyzed 697 patients (578 men and 119 women); the post-OLT AKI incidence was 0.409. Compared with the no-AKI group, the AKI group showed very significant differences in Model for End-stage Liver Disease score (14.74 ± 9.91 vs. 11.07 ± 9.54, Z = 5.404; P < 0.001), hepatic encephalopathy (45 [15.8%] vs. 30 [7.3%], χ 2 = 12.699; P < 0.001), hemofiltration (28 [9.8%] vs. 0 [0.0%], χ 2 = 42.171; P < 0.001), and 28-day mortality (23 [8.1%] vs. 9 [2.2%], χ 2 = 13.323; P <0.001). Moreover, mean values of Cr, BUN, UA, and β 2 -MG in the AKI group differed significantly at postoperative days 1, 3, and 7 (all P < 0.001). ROC curve area was 0.847 of Cr for the detection of AKI Stage 1 (sensitivity 80.1%, specificity 75.7%, cutoff value 88.23 μmol/L), 0.916 for Stage 2 (sensitivity 87.6%, specificity 82.6%, cutoff value 99.9 μmol/L), and 0.972 for Stage 3 (sensitivity 94.1%, specificity 88.2%, cutoff value 122.90 μmol/L). The sensitivity and specificity of serum Cr might be a high-value indicator for the diagnosis and grading of post-OLT AKI.

  14. Survival benefits of interferon-based therapy in patients with recurrent hepatitis C after orthotopic liver transplantation

    PubMed Central

    Zanaga, L.P.; Vigani, A.G.; Angerami, R.N.; Giorgetti, A.; Escanhoela, C.A.F.; Ataíde, E.C.; Boin, I.F.S.F.; Stucchi, R.S.B.

    2017-01-01

    Recurrent hepatitis C after orthotopic liver transplantation (OLT) is universal and can lead to graft failure and, consequently, reduced survival. Hepatitis C treatment can be used to prevent these detrimental outcomes. The aim of this study was to describe rates of hepatitis C recurrence and sustained virological response (SVR) to interferon-based treatment after OLT and its relationship to survival and progression of liver disease through retrospective analysis of medical records of 127 patients who underwent OLT due to cirrhosis or hepatocellular carcinoma secondary to chronic hepatitis C between January 2002 and December 2013. Fifty-six patients were diagnosed with recurrent disease, 42 started interferon-based therapy and 37 completed treatment. Demographic, treatment- and outcome-related variables were compared between SVR and non-responders (non-SVR). There was an overall 54.1% SVR rate with interferon-based therapies. SVR was associated with longer follow-up after treatment (median 66.5 vs 37 months for non-SVR, P=0.03) and after OLT (median 105 vs 72 months, P=0.074), and lower rates of disease progression (15 vs 64.7%, P=0.0028) and death (5 vs 35.3%, P=0.033). Regardless of the result of therapy (SVR or non-SVR), there was a significant difference between treated and untreated patients regarding the occurrence of death (P<0.001) and months of survival (P<0.001). Even with suboptimal interferon-based therapies (compared to the new direct-acting antivirals) there is a 54.1% SVR rate to treatment. SVR is associated with improved survival and reduced risks of clinical decompensation, loss of the liver graft and death. PMID:28076451

  15. An assessment of thromboelastometry to monitor blood coagulation and guide transfusion support in liver transplantation.

    PubMed

    Blasi, Annabel; Beltran, Joan; Pereira, Arturo; Martinez-Palli, Graciela; Torrents, Abiguei; Balust, Jaume; Zavala, Elizabeth; Taura, Pilar; Garcia-Valdecasas, Juan-Carlos

    2012-09-01

    Rotation thromboelastometry (TEM) has been proposed as a convenient alternative to standard coagulation tests in guiding the treatment of coagulopathy during orthotopic liver transplantation (OLT). This study was aimed at assessing the value of TEM in monitoring blood coagulation and guide transfusion support in OLT. Standard coagulation and TEM (EXTEM and FIBTEM) tests were performed at four preestablished intraoperative time points in 236 OLTs and prospectively recorded in a dedicated database together with the main operative and transfusion data. Transfusion thresholds were based on standard coagulation tests. Spearman's rank correlation (ρ), linear regression, and receiver operating characteristic curves were used when appropriate. EXTEM maximum clot firmness (MCF(EXTEM)) was the TEM variable that best correlated with the platelet (PLT) and fibrinogen levels (ρ = 0.62 and ρ = 0.69, respectively). MCF(FIBTEM) correlated with fibrinogen level (ρ = 0.70). EXTEM clot amplitude at 10 minutes (A10(EXTEM)) was a good linear predictor of MCF(EXTEM) (R(2) =0.93). The cutoff values that best predicted the transfusion threshold for PLTs and fibrinogen were A10(EXTEM) = 35 mm and A10(FIBTEM) = 8 mm. At these values, the negative and positive predictive accuracies of TEM to predict the transfusion thresholds were 95 and 27%, respectively. A10(EXTEM) is an adequate TEM variable to guide therapeutic decisions during OLT. Patients with A10(EXTEM) of greater than 35 mm are unlikely to bleed because of coagulation deficiencies, but using A10(EXTEM) of not more than 35 mm as the sole transfusion criterion can lead to unnecessary utilization of PLTs and fibrinogen-rich products. © 2012 American Association of Blood Banks.

  16. Thyroid storm complicated by fulminant hepatic failure: case report and literature review.

    PubMed

    Hambleton, Catherine; Buell, Joseph; Saggi, Bob; Balart, Luis; Shores, Nathan J; Kandil, Emad

    2013-11-01

    Thyroid storm is a presentation of severe thyrotoxicosis that has a mortality rate of up to 20% to 30%. Fulminant hepatic failure (FHF) entails encephalopathy with severe coagulopathy in the setting of liver disease. It carries a high mortality rate, with an approximately 60% rate of overall survival for patients who undergo orthotopic liver transplantation (OLT). Fulminant hepatic failure is a rare but serious complication of thyroid storm. There have been only 6 previously reported cases of FHF with thyroid storm. We present a patient from our institution with thyroid storm and FHF. A literature review was performed to analyze the outcomes of the 6 additional cases of concomitant thyroid storm and FHF. Our patient underwent thyroidectomy followed by OLT. Her serum levels of thyroid-stimulating hormone, triiodothyronine, thyroxine, and transaminase normalized, and she was ready for discharge within 10 days of surgery. She has survived without complication. There is a 40% mortality rate for the reported patients treated medically with these conditions. Of the 7 total cases of reported FHF and thyroid storm, 2 patients died. Only 2 of the 7 patients underwent thyroidectomy and OLT--both at our institution. Both patients survived without complications. Thyroid storm and FHF each independently carry high mortality rates, and managing patients with both conditions simultaneously is an extraordinary challenge. These cases should compel clinicians to investigate liver function in hyperthyroid patients and to be wary of its rapid decline in patients who present in thyroid storm with symptoms of liver dysfunction. Patients with rapidly progressing thyroid storm and FHF should be considered for total thyroidectomy and OLT.

  17. Analysis of INF-gamma, TNF-alpha and dendritic cells to predict hepatitis C virus recurrence in liver transplant patients.

    PubMed

    Ocaña, L; Cos, J; Quer, J; Bilbao, I; Palou, E; Parra, R; Sauleda, S; Esteban, J I; Guàrdia, J; Massuet, L I; Margarit, C

    2005-11-01

    Hepatitis C virus (HCV) infection is one of the leading causes of chronic liver disease and the reason for more than 50% of liver transplantations (OLT). Recurrent HCV infection occurs in almost all transplant recipients and has an unfavorable course. Although immunosuppressive agents are necessary to avoid allograft rejection, these drugs may favor viral replication facilitating viral-mediated graft injury. To predict the evolution of two HCV(+) patients who underwent OLT, we studied INF-gamma and TNF-alpha production and the maturation capacity of dendritic cells (DCs) at three time points: before transplantation (Pre-Tx) and at 2 (2M) and 6 (6M) months after transplantation. Cytometric bead assays were used to quantify INF-gamma and TNF-alpha production in the supernates of mixed leukocyte reactions (MLR) between spleen cells from the liver donor and CD4(+) cells from the recipients. Immature and mature DCs were generated in vitro from patient monocytes. The one patient who experienced recurrent HCV showed loss of CD4(+) responses to donor antigens and INF-gamma and TNF-alpha production after OLT. In contrast, the other patient maintained detectable levels of these cytokines after OLT. It was possible to generate mature DCs from monocytes with the aid of CD40L in both cases, but decreased expression of HLA-DR, CD80, and CD86 markers was observed upon posttransplantation analyses in the patient with recurrent HCV. Loss of the proliferative response as well as INF-gamma and TNF-alpha production, together with a decreased HLA-DR, CD80, and CD86 (markers of mature DCs), indicated an inadequate immune response to viral progression in the liver transplant recipient with relapsing HCV infection.

  18. Betel quid chewing leads to the development of unique de novo malignancies in liver transplant recipients, a retrospective single center study in Taiwan.

    PubMed

    Chen, Yi-Chan; Cheng, Chih-Hsien; Wang, Yu-Chao; Wu, Ting-Jun; Chou, Hong-Shiue; Chan, Kun-Ming; Lee, Wei-Chen; Lee, Chen-Fang; Soong, Ruey Shyang

    2016-09-01

    Orthotopic liver transplantation (OLT) is the choice of treatment not only for end-stage liver disease and acute liver failure but also for hepatocellular carcinoma (HCC). The development of de novo malignancies after liver transplantation plays an important role in late mortality; the incidence of late mortality has increased owing to improved survival. The incidence of de novo malignancies is 2.3% to 25%, which is 2 to 3 times that of malignancies in the general population. The most commonly reported de novo malignancies in solid organs are skin cancer, Karposi sarcoma, and colon cancer according to the frequency of exposure to a specific carcinogen. We hypothesized that exposure to different carcinogens would change the distribution of de novo malignancies among patients after OLT. In Taiwan, 10% of the population is exposed to a unique carcinogen, the betel quid, which is associated with a high incidence of head and neck cancer (HNC) among the Taiwanese population.From 2004 to 2014, we retrospectively reviewed 484 cases post-OLT at our institution and 16 patients with 17 de novo malignancies were identified. Most of the patients had HNC, which is in contrast to previous literature reports.Univariate and multivariate analyses identified betel quid chewing as the main leading factor for HNC in the Taiwanese population.Routine screening of the oral mucosa in patients with the habit of betel quid chewing is recommended in Taiwan for the early detection of HNC. Routine screening with aggressive treatment after diagnosis of HNC in patients with the habit of chewing betel quid, who underwent OLT, resulted in good patient prognosis.

  19. Optical power equalization for upstream traffic with injection-locked Fabry-Perot lasers in TDM-PON

    NASA Astrophysics Data System (ADS)

    Huang, Ting-Tsan; Sheu, Lih-Gen; Chi, Sien

    2010-10-01

    An optical power equalization of upstream traffic in time-division-multiplexed passive optical network (TDM-PON) based on injection-locked Fabry-Perot lasers has been experimentally investigated. The upstream transmitters with stable spectrum are achieved by using an external injection light source in the optical line terminal (OLT). The different upstream powers can be equalized by injection locking a Fabry-Perot laser diode (FP-LD) biased below threshold current in OLT. The dynamic upstream power range from - 8.5 to - 19.5 db m is reduced to a 1.6 dB maximal power variation, when the uplink signal is directly modulated at 1.25 Gb/s.

  20. Prediction of early postoperative infections in pediatric liver transplantation by logistic regression

    NASA Astrophysics Data System (ADS)

    Uzunova, Yordanka; Prodanova, Krasimira; Spassov, Lubomir

    2016-12-01

    Orthotopic liver transplantation (OLT) is the only curative treatment for end-stage liver disease. Early diagnosis and treatment of infections after OLT are usually associated with improved outcomes. This study's objective is to identify reliable factors that can predict postoperative infectious morbidity. 27 children were included in the analysis. They underwent liver transplantation in our department. The correlation between two parameters (the level of blood glucose at 5th postoperative day and the duration of the anhepatic phase) and postoperative infections was analyzed, using univariate analysis. In this analysis, an independent predictive factor was derived which adequately identifies patients at risk of infectious complications after a liver transplantation.

  1. Soil thermal properties at two different sites on James Ross Island in the period 2012/13

    NASA Astrophysics Data System (ADS)

    Hrbáček, Filip; Láska, Kamil

    2015-04-01

    James Ross Island (JRI) is the largest island in the eastern part of the Antarctic Peninsula. Ulu Peninsula in the northern part of JRI is considered the largest ice free area in the Maritime Antarctica region. However, information about permafrost on JRI, active layer and its soil properties in general are poorly known. In this study, results of soil thermal measurements at two different sites on Ulu Peninsula are presented between 1 April 2012 and 30 April 2013. The study sites are located (1) on an old Holocene marine terrace (10 m a. s. l.) in the closest vicinity of Johann Gregor Mendel (JGM) Station and (2) on top of a volcanic plateau named Johnson Mesa (340 m a. s. l.) about 4 km south of the JGM Station. The soil temperatures were measured at 30 min interval using platinum resistance thermometers Pt100/8 in two profiles up to 200 cm at JGM Station and 75 cm at Johnson Mesa respectively. Decagon 10HS volumetric water content sensors were installed up 30 cm at Johnson Mesa to 50 cm at JGM Station, while Hukseflux HFP01 soil heat flux sensors were used for direct monitoring of soil physical properties at 2.5 cm depth at both sites. The mean soil temperature varied between -5.7°C at 50 cm and -6.3°C at 5 cm at JGM Station, while that for Johnson Mesa varied between -6.9°C at 50 cm and -7.1°C at 10 cm. Maximum active layer thickness estimated from 0 °C isotherm reached 52 cm at JGM Station and 50 cm at Johnson Mesa respectively which corresponded with maximum observed annual temperature at 50 cm at both sites. The warmest part of both profiles detected at 50 cm depth corresponded with maximum thickness of active layer, estimated from 0°C isotherm, reached 52 cm at JGM Station and 50 cm at Johnson Mesa respectively. Volumetric water content at 5 cm varied around 0.25 m3m-3 at both sites. The slight increase to 0.32 m3m-3 was observed at JGM Station at 50 cm and at Johnson Mesa at 30 cm depth. Soil texture analysis showed distinctly higher share of coarser

  2. Prevention of hypothermia in patients undergoing orthotopic liver transplantation using the humigard® open surgery humidification system: a prospective randomized pilot and feasibility clinical trial.

    PubMed

    Weinberg, Laurence; Huang, Andrew; Alban, Daniel; Jones, Robert; Story, David; McNicol, Larry; Pearce, Brett

    2017-01-23

    Perioperative thermal disturbances during orthotopic liver transplantation (OLT) are common. We hypothesized that in patients undergoing OLT the use of a humidified high flow CO 2 warming system maintains higher intraoperative temperatures when compared to standardized multimodal strategies to maintain thermoregulatory homeostasis. We performed a randomized pilot study in adult patients undergoing primary OLT. Participants were randomized to receive either open wound humidification with a high flow CO 2 warming system in addition to standard care (Humidification group) or to standard care alone (Control group). The primary end point was nasopharyngeal core temperature measured 5 min immediately prior to reperfusion of the donor liver (Stage 3 - 5 min). Secondary endpoints included intraoperative PaCO 2 , minute ventilation and the use of vasoconstrictors. Eleven patients were randomized to each group. Both groups were similar for age, body mass index, MELD, SOFA and APACHE II scores, baseline temperature, and duration of surgery. Immediately prior to reperfusion (Stage 3 - 5 min) the mean (SD) core temperature was higher in the Humidification Group compared to the Control Group: 36.0 °C (0.13) vs. 35.4 °C (0.22), p = 0.028. Repeated measured ANOVA showed that core temperatures over time during the stages of the transplant were higher in the Humidification Group compared to the Control Group (p < 0.0001). There were no significant differences in the ETCO 2 , PaCO 2 , minute ventilation, or inotropic support. The humidified high flow CO 2 warming system was superior to standardized multimodal strategies in maintaining normothermia in patients undergoing OLT. Use of the device was feasible and did not interfere with any aspects of surgery. A larger study is needed to investigate if the improved thermoregulation observed is associated with improved patient outcomes. ACTRN12616001631493 . Retrospectively registered 25 November 2016.

  3. 10Gbps monolithic silicon FTTH transceiver for PON

    NASA Astrophysics Data System (ADS)

    Zhang, J.; Liow, T. Y.; Lo, G. Q.; Kwong, D. L.

    2010-05-01

    We propose a new passive optical network (PON) configuration and a novel silicon photonic transceiver architecture for optical network unit (ONU), eliminating the need for an internal laser source in ONU. We adopt dual fiber network configuration. The internal light source in each of the ONUs is eliminated. Instead, an extra seed laser source in the optical line termination (OLT) operates in continuous wave mode to serve the ONUs in the PON as a shared and centralized laser source. λ1 from OLT Tx and λ2 from the seed laser are combined by using a WDM combiner and connected to serve the multiple ONUs through the downstream fibers. The ONUs receive the data in λ1. Meanwhile, the ONUs encode and transmit data in λ2, which are sent back to OLT. The monolithic ONU transceiver contains a wavelength-division-multiplexing (WDM) filter component, a silicon modulator and a Ge photo-detector. The WDM in ONU selectively guides λ1 to the Ge-PD where the data in λ1 are detected and converted to electrical signals, and λ2 to the transmitter where the light is modulated by upstream data. The modulated optical signals in λ2 from ONUs are connected back to OLT through upstream fibers. The monolithic ONU transceiver chip size is only 2mm by 4mm. The crosstalk between the Tx and Rx is measured to be less than -20dB. The transceiver chip is integrated on a SFP+ transceiver board. Both Tx and Rx demonstrated data rate capabilities of up to 10Gbps. By implementing this scheme, the ONU transceiver size can be significantly reduced and the assembly processes will be greatly simplified. The results demonstrate the feasibility of mass manufacturing monolithic silicon ONU transceivers via low cost

  4. Analysis of opioid-mediated analgesia in Phase III studies of methylnaltrexone for opioid-induced constipation in patients with chronic noncancer pain

    PubMed Central

    Webster, Lynn R; Brenner, Darren M; Barrett, Andrew C; Paterson, Craig; Bortey, Enoch; Forbes, William P

    2015-01-01

    Background Subcutaneous methylnaltrexone is efficacious and well tolerated for opioid-induced constipation (OIC) but may theoretically disrupt opioid-mediated analgesia. Methods Opioid use, pain intensity, and opioid withdrawal (Objective Opioid Withdrawal Scale [OOWS] and Subjective Opiate Withdrawal Scale [SOWS] scores) were reported in a randomized, double-blind trial with an open-label extension (RCT) and an open-label trial (OLT) evaluating safety in adults with chronic noncancer pain. In the RCT, patients taking ≥50 mg of oral morphine equivalents daily with <3 rescue-free bowel movements weekly received methyl naltrexone 12 mg once daily (n=150), every other day (n=148), or placebo (n=162) for 4 weeks, followed by open-label methylnaltrexone 12 mg (as needed [prn]; n=364) for 8 weeks. In the OLT, patients (n=1,034) on stable opioid doses with OIC received methylnaltrexone 12 mg prn for up to 48 weeks. Results Minimal fluctuations of median morphine equivalent dose from baseline (BL) were observed in the RCT double-blind period (BL, 154.8–161.0 mg/d; range, 137.1–168.0 mg/d), RCT open-label period (BL, 156.3–174.6; range, 144.0–180.0) and OLT (BL, 120 mg/d; range, 117.3–121.1 mg/d). No significant change from BL in pain intensity score occurred in any group at weeks 2 or 4 (both P≥0.1) of the RCT double-blind period, and scores remained stable during the open-label period and in the OLT (mean change, −0.2 to 0.1). Changes from BL in OOWS and SOWS scores during the double-blind period were not significantly impacted by methylnaltrexone exposure at weeks 2 or 4 (P>0.05 for all). Conclusion Methylnaltrexone did not affect opioid-mediated analgesia in patients with chronic noncancer pain and OIC. PMID:26586963

  5. Septuagenarian and octogenarian donors provide excellent liver grafts for transplantation.

    PubMed

    Darius, T; Monbaliu, D; Jochmans, I; Meurisse, N; Desschans, B; Coosemans, W; Komuta, M; Roskams, T; Cassiman, D; van der Merwe, S; Van Steenbergen, W; Verslype, C; Laleman, W; Aerts, R; Nevens, F; Pirenne, J

    2012-11-01

    Wider utilization of liver grafts from donors ≥ 70 years old could substantially expand the organ pool, but their use remains limited by fear of poorer outcomes. We examined the results at our center of liver transplantation (OLT) using livers from donors ≥ 70 years old. From February 2003 to August 2010, we performed 450 OLT including 58 (13%) using donors ≥ 70 whose outcomes were compared with those using donors <70 years old. Cerebrovascular causes of death predominated among donors ≥ 70 (85% vs 47% in donors <70; P < .001). In contrast, traumatic causes of death predominated among donors <70 (36% vs 14% in donors ≥ 70; P = .002). Unlike grafts from donors <70 years old, grafts from older individuals had no additional risk factors (steatosis, high sodium, or hemodynamic instability). Both groups were comparable for cold and warm ischemia times. No difference was noted in posttransplant peak transaminases, incidence of primary nonfunction, hepatic artery thrombosis, biliary strictures, or retransplantation rates between groups. The 1- and 5-year patient survivals were 88% and 82% in recipients of livers <70 versus 90% and 84% in those from ≥ 70 years old (P = .705). Recipients of older grafts, who were 6 years older than recipients of younger grafts (P < .001), tended to have a lower laboratory Model for End-Stage Liver Disease score (P = .074). Short and mid-term survival following OLT using donors ≥ 70 yo can be excellent provided that there is adequate donor and recipient selection. Septuagenarians and octogenarians with cerebrovascular ischemic and bleeding accidents represent a large pool of potential donors whose wider use could substantially reduce mortality on the OLT waiting list. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Bidirectional multi-optical line terminals incorporated converged WSN-PON network using M/M/1 queuing

    NASA Astrophysics Data System (ADS)

    Kumar, Love; Sharma, Vishal; Singh, Amarpal

    2017-12-01

    Wireless Sensor Networks (WSNs) have an assortment of application areas, for instance, civil, military, and video surveillance with restricted power resources and transmission link. To accommodate the massive traffic load in hefty sensor networks is another key issue. Subsequently, there is a necessity to backhaul the sensed information of such networks and prolong the transmission link to access the distinct receivers. Passive Optical Network (PON), a next-generation access technology, comes out as a suitable candidate for the convergence of the sensed data to the core system. The earlier demonstrated work with single-OLT-PON introduces an overloaded buffer akin to video surveillance scenarios. In this paper, to combine the bandwidth potential of PONs with the mobility capability of WSNs, the viability for the convergence of PONs and WSNs incorporating multi-optical line terminals is demonstrated to handle the overloaded OLTs. The existing M/M/1 queue theory with interleaving polling with adaptive cycle time as dynamic bandwidth algorithm is used to shun the probability of packets clash. Further, the proposed multi-sink WSN and multi-OLT PON converged structure is investigated in bidirectional mode analytically and through computer simulations. The observations establish the proposed structure competent to accommodate the colossal data traffic through less time consumption.

  7. A CLS-based survivable and energy-saving WDM-PON architecture

    NASA Astrophysics Data System (ADS)

    Zhu, Min; Zhong, Wen-De; Zhang, Zhenrong; Luan, Feng

    2013-11-01

    We propose and demonstrate an improved survivable and energy-saving WDM-PON with colorless ONUs. It incorporates both energy-saving and self-healing operations. A simple effective energy-saving scheme is proposed by including an energy-saving control unit in the OLT and a control unit at each ONU. The energy-saving scheme realizes both dozing and sleep (offline) modes, which greatly improves the energy-saving efficiency for WDM-PONs. An intelligent protection switching scheme is designed in the OLT, which can distinguish if an ONU is in dozing/sleep (offline) state or a fiber is faulty. Moreover, by monitoring the optical power of each channel on both working and protection paths, the OLT can know the connection status of every fiber path, thus facilitating an effective protection switching and a faster failure recovery. The improved WDM-PON architecture not only significantly reduces energy consumption, but also performs self-healing operation in practical operation scenarios. The scheme feasibility is experimentally verified with 10 Gbit/s downstream and 1.25 Gbit/s upstream transmissions. We also examine the energy-saving efficiency of our proposed energy-saving scheme by simulation, which reveals that energy saving mainly arises from the dozing mode, not from the sleep mode when the ONU is in the online state.

  8. Liver transplantation from hepatitis B surface antigen positive donors: a safe way to expand the donor pool.

    PubMed

    Loggi, Elisabetta; Micco, Lorenzo; Ercolani, Giorgio; Cucchetti, Alessandro; Bihl, Florian K; Grazi, Gian Luca; Gitto, Stefano; Bontadini, Andrea; Bernardi, Mauro; Grossi, Paolo; Costa, Alessandro Nanni; Pinna, Antonio Daniele; Brander, Christian; Andreone, Pietro

    2012-03-01

    The main limitation of orthotopic liver transplantation (OLT) is the scarcity of available donor organs. A possibility to increase the organ pool is to use grafts from hepatitis B virus surface antigen (HBsAg) positive donors, but few data are currently available in this setting. We assessed the clinical, serovirological, and immunological outcomes of liver transplant from HBsAg positive donors in a single centre study. From 2005 to 2009 10 patients underwent OLT from HBsAg positive donors, for HBV-related disease (n=6) or HBV-unrelated disease (n=4). The median follow-up was 42 months (range 12-60). All recipients were HBcAb positive and were given antiviral prophylaxis. Patients transplanted for HBV-related disease never cleared HBsAg. Two HBsAg negative patients never tested positive for HBsAg, whereas the others experienced an HBsAg appearance, followed by spontaneous production of anti-HBs, allowing HBsAg clearance. No patient ever had any sign of HBV hepatitis. HBV replication was effectively controlled by antiviral therapy. The immunologic sub-study showed that a most robust anti-HBV specific T cell response was associated with the control of HBV infection. OLT from HBsAg positive donors seems to be a safe procedure in the era of highly effective antiviral therapy. Copyright © 2011 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  9. Endoscopic treatment of bile duct complications after orthotopic liver transplantation.

    PubMed

    Polese, L; Cillo, U; Brolese, A; Boccagni, P; Neri, D; Bassi, D; Erroi, F; Zanus, G; D'Amico, D F; Norberto, L

    2007-01-01

    To assess the indications and results of endoscopic retrograde cholangio-pancreatography (ERCP) in patients who have undergone ortotopic liver transplantation (OLT). We reviewed data from 42 consecutive patients who underwent ERCP for biliary complications after OLT over an 8-year period, in particular recording indications and success of the treatment after a mean of 17 months follow-up. Cholangiograms performed in 33/42 patients (79%) displayed anastomotic strictures in 17 patients (52%), bile duct stones in 8 (24%), both bile duct stones and an anastomotic stricture in 2 (6%), papillary stenosis in 1 (3%), and anastomotic biliary leakage in 1 (3%). In contrast, the contrastogram was normal in four patients (12%). Stone extraction was completed in 9/10 patients (90%) with a mean of 1.2 sessions, while stricture dilation was achieved in 12/19 patients (63%) after a mean of 1.7 sessions, by stent positioning (n = 7), balloon dilation (n = 4), or Soehendra dilator (n = 1). Both biliary leakage and papillary stenosis were cured by ERCP. Only one procedure-related complication -- severe pancreatitis (2.4%) -- was observed and no mortality. ERCP is a safe and effective mode of management of bile duct complications after OLT. It should be attempted before a surgical approach. Better results are obtained for treatment of biliary stones than of anastomotic strictures.

  10. Dose requirements of continuous infusion of rocuronium and atracurium throughout orthotopic liver transplantation in humans

    PubMed Central

    Weng, Xiao-chuan; Zhou, Liang; Fu, Yin-yan; Zhu, Sheng-mei; He, Hui-liang; Wu, Jian

    2005-01-01

    Objective: To compare the dose requirements of continuous infusion of rocuronium and atracurium throughout orthotopic liver transplantation (OLT) in humans. Methods: Twenty male patients undergoing liver transplantation were randomly assigned to two comparable groups of 10 patients each to receive a continuous infusion of rocuronium or atracurium under intravenous balanced anesthesia. The response of adductor pollicis to train-of-four (TOF) stimulation of unlar nerve was monitored. The infusion rates of rocuronium and atracurium were adjusted to maintain T1/Tc ratio of 2%~10%. The total dose of each drug given during each of the three phases of OLT was recorded. Results: Rocuronium requirement, which were (0.468±0.167) mg/(kg·h) during the paleohepatic phase, decreased significantly during the anhepatic phase to (0.303±0.134) mg/(kg·h) and returned to the initial values at the neohepatic period ((0.429±0.130) mg/(kg·h)); whereas atracuruim requirements remained unchanged during orthotopic liver transplantation. Conclusions: This study showed that the exclusion of the liver from the circulation results in the significantly reduced requirement of rocuronium while the requirement of atracurium was not changed, which suggests that the liver is of major importance in the clearance of rocuronium. A continuous infusion of atracurium with constant rate can provide stable neuromuscular blockade during the three stages of OLT. PMID:16130187

  11. Intrahepatic bilioenteric anastomosis after biliary complications of liver transplantation: operative rescue of surgical failures.

    PubMed

    Mercado, Miguel Angel; Vilatobá, Mario; Chan, Carlos; Domínguez, Ismael; Leal, Rafael Paulino; Olivera, Marco Antonio

    2009-03-01

    Biliary complications after orthotopic liver transplantation (OLT) are multifactorial in origin. In most series, the frequency of such complications ranges from 5-20%. Most can be treated by endoscopy and/or interventional radiology. For cases in which this option is not successful, surgical approach is indicated. We report the results of reoperation using an intrahepatic bilioenteric anastomosis. The medical charts of patients with biliary complications after OLT during a 10-year period (1997-2007), who failed to respond to nonsurgical treatment and were surgically treated, were reviewed. Roux-en-Y hepatojejunostomy was performed. Segments IV and V were partially removed after cutting the hilar plate, thus obtaining healthy ducts without ischemic or inflammatory reaction and allowing a wide hepatojejunostomy. Five cases (8.4%) with biliary complications after duct-to-duct anastomosis not amenable to further endoscopic management or interventional radiology were identified. Hepaticojejunostomy was achieved in all cases (wide, tension-free, nonischemic, fine hydrolyzable sutures), and segments IV and V were partially removed. No cholangitis, jaundice, and liver function test abnormalities were present in the postoperative. Mean follow-up was 24 months. Only one patient died of causes not related to bile duct reconstruction during follow-up. Intrahepatic hepatojejunostomy with partial resection of segments IV and V offers an excellent therapeutic alternative for biliary complications that require a surgical approach after OLT.

  12. Power budget of direct-detection ultra-dense WDM-Nyquist-SCM PON with low-complexity SSBI mitigation

    NASA Astrophysics Data System (ADS)

    Soeiro, Ricardo O. J.; Alves, Tiago M. F.; Cartaxo, Adolfo V. T.

    2017-07-01

    The power budget (PB) of a direct-detection ultra-dense wavelength division/subcarrier multiplexing (SCM) passive optical network (PON) is assessed numerically for downstream, when a low-complexity iterative signal-to-signal beat interference (SSBI) mitigation technique is employed. Each SCM signal, inserted in a 12.5 GHz width optical channel, is comprised of two or three electrically generated and multiplexed 16-quadrature-amplitude-modulation (QAM) or 32-QAM Nyquist pulse-shaped subcarriers, each with a 7% forward error correction bit rate of 10.7 Gbit/s. The PB and maximum number of optical network units (ONUs) served by each optical line terminal (OLT) are compared with and without SSBI mitigation. When SSBI mitigation is realized, PB gains up to 4.5 dB are attained relative to the PB in the absence of SSBI mitigation. The PB gain enabled by the SSBI mitigation technique proposed in this work increases the number of ONUs served per OLT at least by a factor of 2, for the cases of higher spectral efficiency. In particular, for a SCM signal comprised of three subcarriers, the maximum number of ONUs served per OLT is between 2 and 32, and between 8 and 64, in the absence of SSBI mitigation, and when SSBI mitigation is employed, respectively, depending on the fiber length (up to 50 km) and order of QAM.

  13. Design of a mutual authentication based on NTRUsign with a perturbation and inherent multipoint control protocol frames in an Ethernet-based passive optical network

    NASA Astrophysics Data System (ADS)

    Yin, Aihan; Ding, Yisheng

    2014-11-01

    Identity-related security issues inherently present in passive optical networks (PON) still exist in the current (1G) and next-generation (10G) Ethernet-based passive optical network (EPON) systems. We propose a mutual authentication scheme that integrates an NTRUsign digital signature algorithm with inherent multipoint control protocol (MPCP) frames over an EPON system between the optical line terminal (OLT) and optical network unit (ONU). Here, a primitive NTRUsign algorithm is significantly modified through the use of a new perturbation so that it can be effectively used for simultaneously completing signature and authentication functions on the OLT and the ONU sides. Also, in order to transmit their individual sensitive messages, which include public key, signature, and random value and so forth, to each other, we redefine three unique frames according to MPCP format frame. These generated messages can be added into the frames and delivered to each other, allowing the OLT and the ONU to go ahead with a mutual identity authentication process to verify their legal identities. Our simulation results show that this proposed scheme performs very well in resisting security attacks and has low influence on the registration efficiency to to-be-registered ONUs. A performance comparison with traditional authentication algorithms is also presented. To the best of our knowledge, no detailed design of mutual authentication in EPON can be found in the literature up to now.

  14. A proposal for an SDN-based SIEPON architecture

    NASA Astrophysics Data System (ADS)

    Khalili, Hamzeh; Sallent, Sebastià; Piney, José Ramón; Rincón, David

    2017-11-01

    Passive Optical Network (PON) elements such as Optical Line Terminal (OLT) and Optical Network Units (ONUs) are currently managed by inflexible legacy network management systems. Software-Defined Networking (SDN) is a new networking paradigm that improves the operation and management of networks. In this paper, we propose a novel architecture, based on the SDN concept, for Ethernet Passive Optical Networks (EPON) that includes the Service Interoperability standard (SIEPON). In our proposal, the OLT is partially virtualized and some of its functionalities are allocated to the core network management system, while the OLT itself is replaced by an OpenFlow (OF) switch. A new MultiPoint MAC Control (MPMC) sublayer extension based on the OpenFlow protocol is presented. This would allow the SDN controller to manage and enhance the resource utilization, flow monitoring, bandwidth assignment, quality-of-service (QoS) guarantees, and energy management of the optical network access, to name a few possibilities. The OpenFlow switch is extended with synchronous ports to retain the time-critical nature of the EPON network. OpenFlow messages are also extended with new functionalities to implement the concept of EPON Service Paths (ESPs). Our simulation-based results demonstrate the effectiveness of the new architecture, while retaining a similar (or improved) performance in terms of delay and throughput when compared to legacy PONs.

  15. Hypothermic oxygenated machine perfusion (HOPE) for orthotopic liver transplantation of human liver allografts from extended criteria donors (ECD) in donation after brain death (DBD): a prospective multicentre randomised controlled trial (HOPE ECD-DBD).

    PubMed

    Czigany, Zoltan; Schöning, Wenzel; Ulmer, Tom Florian; Bednarsch, Jan; Amygdalos, Iakovos; Cramer, Thorsten; Rogiers, Xavier; Popescu, Irinel; Botea, Florin; Froněk, Jiří; Kroy, Daniela; Koch, Alexander; Tacke, Frank; Trautwein, Christian; Tolba, Rene H; Hein, Marc; Koek, Ger H; Dejong, Cornelis H C; Neumann, Ulf Peter; Lurje, Georg

    2017-10-10

    Orthotopic liver transplantation (OLT) has emerged as the mainstay of treatment for end-stage liver disease. In an attempt to improve the availability of donor allografts and reduce waiting list mortality, graft acceptance criteria were extended increasingly over the decades. The use of extended criteria donor (ECD) allografts is associated with a higher incidence of primary graft non-function and/or delayed graft function. As such, several strategies have been developed aiming at reconditioning poor quality ECD liver allografts. Hypothermic oxygenated machine perfusion (HOPE) has been successfully tested in preclinical experiments and in few clinical series of donation after cardiac death OLT. HOPE ECD-DBD is an investigator-initiated, open-label, phase-II, prospective multicentre randomised controlled trial on the effects of HOPE on ECD allografts in donation after brain death (DBD) OLT. Human whole organ liver grafts will be submitted to 1-2 hours of HOPE (n=23) via the portal vein before implantation and are going to be compared with a control group (n=23) of patients transplanted after conventional cold storage. Primary (peak and Δ peak alanine aminotransferase within 7 days) and secondary (aspartate aminotransferase, bilirubin and international normalised ratio, postoperative complications, early allograft dysfunction, duration of hospital and intensive care unit stay, 1-year patient and graft survival) endpoints will be analysed within a 12-month follow-up. Extent of ischaemia-reperfusion (I/R) injury will be assessed using liver tissue, perfusate, bile and serum samples taken during the perioperative phase of OLT. The study was approved by the institutional review board of the RWTH Aachen University, Aachen, Germany (EK 049/17). The current paper represent the pre-results phase. First results are expected in 2018. NCT03124641. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No

  16. A novel wavelength reused bidirectional RoF-WDM-PON architecture to mitigate reflection and Rayleigh backscattered noise in multi-Gb/s m-QAM OFDM SSB upstream and downstream transmission over a single fiber

    NASA Astrophysics Data System (ADS)

    Patel, Dhananjay; Dalal, U. D.

    2017-05-01

    A novel m-QAM Orthogonal Frequency Division Multiplexing (OFDM) Single Sideband (SSB) architecture is proposed for centralized light source (CLS) bidirectional Radio over Fiber (RoF) - Wavelength Division Multiplexing (WDM) - Passive Optical Network (PON). In bidirectional transmission with carrier reuse over the single fiber, the Rayleigh Backscattering (RB) noise and reflection (RE) interferences from optical components can seriously deteriorate the transmission performance of the fiber optic systems. These interferometric noises can be mitigated by utilizing the optical modulation schemes at the Optical Line Terminal (OLT) and Optical Network Unit (ONU) such that the spectral overlap between the optical data spectrum and the RB and RE noise is minimum. A mathematical model is developed for the proposed architecture to accurately measure the performance of the transmission system and also to analyze the effect of interferometric noise caused by the RB and RE. The model takes into the account the different modulation schemes employed at the OLT and the ONU using a Mach Zehnder Modulator (MZM), the optical launch power and the bit-rates of the downstream and upstream signals, the gain of the amplifiers at the OLT and the ONU, the RB-RE noise, chromatic dispersion of the single mode fiber and optical filter responses. In addition, the model analyzes all the components of the RB-RE noise such as carrier RB, signal RB, carrier RE and signal RE, thus providing the complete representation of all the physical phenomena involved. An optical m-QAM OFDM SSB signal acts as a test signal to validate the model which provides excellent agreement with simulation results. The SSB modulation technique using the MZM at the OLT and the ONU differs in the data transmission technique that takes place through the first-order higher and the lower optical sideband respectively. This spectral gap between the downstream and upstream signals reduces the effect of Rayleigh backscattering and

  17. KEAP1-NRF2 COMPLEX IN ISCHEMIA-INDUCED HEPATOCELLULAR DAMAGE OF MOUSE LIVER TRANSPLANTS

    PubMed Central

    Ke, Bibo; Shen, Xiu-Da; Zhang, Yu; Ji, Haofeng; Gao, Feng; Yue, Shi; Kamo, Naoko; Zhai, Yuan; Yamamoto, Masayuki; Busuttil, Ronald W.; Kupiec-Weglinski, Jerzy W.

    2015-01-01

    Background The Keap1-Nrf2 signaling pathway regulates host cell defense responses against oxidative stress and maintains the cellular redox balance. Aims&Methods: We investigated the function/molecular mechanisms by which Keap1-Nrf2 complex may influence liver ischemia/reperfusion injury (IRI) in a mouse model of hepatic cold storage (20h at 4 C) followed by orthotopic liver transplantation (OLT). Results The Keap1 hepatocyte-specific knock-out (HKO) in the donor liver ameliorated post-transplant IRI, evidenced by improved hepatocellular function and OLT outcomes (Keap1HKO Keap1HKO; 100% survival), as compared with controls (WT WT; 50% survival; p<0.01). In contrast, donor liver Nrf2 deficiency exacerbated IRI in transplant recipients (Nrf2KO Nrf2KO; 40% survival). Ablation of Keap1 signaling reduced macrophage/neutrophil trafficking, pro-inflammatory cytokine programs, and hepatocellular necrosis/apoptosis, while simultaneously promoting anti-apoptotic functions in OLTs. At the molecular level, Keap1HKO increased Nrf2 levels, stimulated Akt phosphorylation, and enhanced expression of anti-oxidant Trx1, HIF-1 , and HO-1. Pretreatment of liver donors with PI3K inhibitor (LY294002) disrupted Akt/HIF-1 signaling and recreated hepatocellular damage in otherwise IR-resistant Keap1HKO transplants. In parallel in vitro studies, hydrogen peroxide-stressed Keap1-deficient hepatocytes were characterized by enhanced expression of Nrf2, Trx1, and Akt phosphorylation, in association with decreased release of lactate dehydrogenase (LDH) in cell culture supernatants. Conclusions Keap1-Nrf2 complex prevents oxidative injury in IR-stressed OLTs through Keap1 signaling, which negatively regulates Nrf2 pathway. Activation of Nrf2 induces Trx1 and promotes PI3K/Akt, crucial for HIF-1 activity. HIF-1 -mediated overexpression of HO-1/CyclinD1 facilitates cytoprotection by limiting hepatic inflammatory responses, and hepatocellular necrosis/apoptosis in PI3K-dependent manner. PMID

  18. Glacial-interglacial dynamics of Antarctic firn columns: comparison between simulations and ice core air-?15N measurements

    NASA Astrophysics Data System (ADS)

    Capron, E.; Landais, A.; Buiron, D.; Cauquoin, A.; Chappellaz, J. A.; Debret, M.; Jouzel, J.; Leuenberger, M.; Martinerie, P.; Masson-Delmotte, V.; Mulvaney, R.; Parrenin, F.; Prié, F.

    2013-12-01

    Correct estimation of the firn lock-in depth is essential for correctly linking gas and ice chronologies in ice core studies. Here, two approaches to constrain the firn depth evolution in Antarctica are presented over the last deglaciation: outputs of a firn densification model, and measurements of δ15N of N2 in air trapped in ice core, assuming that δ15N is only affected by gravitational fractionation in the firn column. Since the firn densification process is largely governed by surface temperature and accumulation rate, we have investigated four ice cores drilled in coastal (Berkner Island, BI, and James Ross Island, JRI) and semi-coastal (TALDICE and EPICA Dronning Maud Land, EDML) Antarctic regions. Combined with available ice core air- δ15N measurements from the EPICA Dome C (EDC) site, the studied regions encompass a large range of surface accumulation rates and temperature conditions. Our δ15N profiles reveal a heterogeneous response of the firn structure to glacial-interglacial climatic changes. While firn densification simulations correctly predict TALDICE δ15N variations, they systematically fail to capture the large millennial-scale δ15N variations measured at BI and the δ15N glacial levels measured at JRI and EDML - a mismatch previously reported for central East Antarctic ice cores. New constraints of the EDML gas-ice depth offset during the Laschamp event (41 ka) and the last deglaciation do not favour the hypothesis of a large convective zone within the firn as the explanation of the glacial firn model- δ15N data mismatch for this site. While we could not conduct an in-depth study of the influence of impurities in snow for firnification from the existing datasets, our detailed comparison between the δ15N profiles and firn model simulations under different temperature and accumulation rate scenarios suggests that the role of accumulation rate may have been underestimated in the current description of firnification models.

  19. Glacial-interglacial dynamics of Antarctic firn columns: comparison between simulations and ice core air-δ15N measurements

    NASA Astrophysics Data System (ADS)

    Capron, E.; Landais, A.; Buiron, D.; Cauquoin, A.; Chappellaz, J.; Debret, M.; Jouzel, J.; Leuenberger, M.; Martinerie, P.; Masson-Delmotte, V.; Mulvaney, R.; Parrenin, F.; Prié, F.

    2013-05-01

    Correct estimation of the firn lock-in depth is essential for correctly linking gas and ice chronologies in ice core studies. Here, two approaches to constrain the firn depth evolution in Antarctica are presented over the last deglaciation: outputs of a firn densification model, and measurements of δ15N of N2 in air trapped in ice core, assuming that δ15N is only affected by gravitational fractionation in the firn column. Since the firn densification process is largely governed by surface temperature and accumulation rate, we have investigated four ice cores drilled in coastal (Berkner Island, BI, and James Ross Island, JRI) and semi-coastal (TALDICE and EPICA Dronning Maud Land, EDML) Antarctic regions. Combined with available ice core air-δ15N measurements from the EPICA Dome C (EDC) site, the studied regions encompass a large range of surface accumulation rates and temperature conditions. Our δ15N profiles reveal a heterogeneous response of the firn structure to glacial-interglacial climatic changes. While firn densification simulations correctly predict TALDICE δ15N variations, they systematically fail to capture the large millennial-scale δ15N variations measured at BI and the δ15N glacial levels measured at JRI and EDML - a mismatch previously reported for central East Antarctic ice cores. New constraints of the EDML gas-ice depth offset during the Laschamp event (~41 ka) and the last deglaciation do not favour the hypothesis of a large convective zone within the firn as the explanation of the glacial firn model-δ15N data mismatch for this site. While we could not conduct an in-depth study of the influence of impurities in snow for firnification from the existing datasets, our detailed comparison between the δ15N profiles and firn model simulations under different temperature and accumulation rate scenarios suggests that the role of accumulation rate may have been underestimated in the current description of firnification models.

  20. An All-Optical Access Metro Interface for Hybrid WDM/TDM PON Based on OBS

    NASA Astrophysics Data System (ADS)

    Segarra, Josep; Sales, Vicent; Prat, Josep

    2007-04-01

    A new all-optical access metro network interface based on optical burst switching (OBS) is proposed. A hybrid wavelength-division multiplexing/time-division multiplexing (WDM/TDM) access architecture with reflective optical network units (ONUs), an arrayed-waveguide-grating outside plant, and a tunable laser stack at the optical line terminal (OLT) is presented as a solution for the passive optical network. By means of OBS and a dynamic bandwidth allocation (DBA) protocol, which polls the ONUs, the available access bandwidth is managed. All the network intelligence and costly equipment is located at the OLT, where the DBA module is centrally implemented, providing quality of service (QoS). To scale this access network, an optical cross connect (OXC) is then used to attain a large number of ONUs by the same OLT. The hybrid WDM/TDM structure is also extended toward the metropolitan area network (MAN) by introducing the concept of OBS multiplexer (OBS-M). The network element OBS-M bridges the MAN and access networks by offering all-optical cross connection, wavelength conversion, and data signaling. The proposed innovative OBS-M node yields a full optical data network, interfacing access and metro with a geographically distributed access control. The resulting novel access metro architectures are nonblocking and, with an improved signaling, provide QoS, scalability, and very low latency. Finally, numerical analysis and simulations demonstrate the traffic performance of the proposed access scheme and all-optical access metro interface and architectures.

  1. Dilemmas across different overseas liver transplant stages: Taiwan transplant recipient families' perspectives.

    PubMed

    Chen, H-M; Hu, R-H; Shih, F-Jong; Shih, F-J

    2012-03-01

    This study aimed to explore the dilemmas of Taiwanese overseas liver transplant recipient families (OLTRF) across three overseas liver transplant (OLT) stages in Taiwan and Mainland China. An exploratory qualitative method was employed using a purposive sample of OLTRF, who received guided face-to-face, semistructured interviews. Data were subjected to content analysis. Nineteen OLTRF (15 female, 4 male) aged between 29 and 71 years (mean 55.1) for 19 patients with end-stage liver diseases were interviewed. OLT stages including predeparture stage (first stage), stay in China stage (second stage), and reentry to Taiwan stage (third stage). Ten kinds of dilemmas were encountered: (1) unable to get transplantation immediately (first to second stages); (2) dilemma of choosing overseas transplantation (first to second stages); (3) uncertainty about the transplantation outcomes (second to third stages); (4) care pressure (second to third stages); (5) poor diet adaptation (second to third stages); (6) lack of trust in the medical care quality (second stage); (7) worry about not fulfilling family responsibilities (second stage); (8) lack of information (all stages); (9) financial pressure (all stages); and (10) frustration when seeking medical care (all stages). Taiwanese OLTRF's perspectives of their dilemmas through the OLT process were first revealed in this study. Both Western and Eastern health professionals might be empowered by better understanding of OLTRF's living experiences and concerns during the stages of overseas liver transplantation. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Demonstration of flexible multicasting and aggregation functionality for TWDM-PON

    NASA Astrophysics Data System (ADS)

    Chen, Yuanxiang; Li, Juhao; Zhu, Paikun; Zhu, Jinglong; Tian, Yu; Wu, Zhongying; Peng, Huangfa; Xu, Yongchi; Chen, Jingbiao; He, Yongqi; Chen, Zhangyuan

    2017-06-01

    The time- and wavelength-division multiplexed passive optical network (TWDM-PON) has been recognized as an attractive solution to provide broadband access for the next-generation networks. In this paper, we propose flexible service multicasting and aggregation functionality for TWDM-PON utilizing multiple-pump four-wave-mixing (FWM) and cyclic arrayed waveguide grating (AWG). With the proposed scheme, multiple TWDM-PON links share a single optical line terminal (OLT), which can greatly reduce the network deployment expense and achieve efficient network resource utilization by load balancing among different optical distribution networks (ODNs). The proposed scheme is compatible with existing TDM-PON infrastructure with fixed-wavelength OLT transmitter, thus smooth service upgrade can be achieved. Utilizing the proposed scheme, we demonstrate a proof-of-concept experiment with 10-Gb/s OOK and 10-Gb/s QPSK orthogonal frequency division multiplexing (OFDM) signal multicasting and aggregating to seven PON links. Compared with back-to-back (BTB) channel, the newly generated multicasting OOK signal and OFDM signal have power penalty of 1.6 dB and 2 dB at the BER of 10-3, respectively. For the aggregation of multiple channels, no obvious power penalty is observed. What is more, to verify the flexibility of the proposed scheme, we reconfigure the wavelength selective switch (WSS) and adjust the number of pumps to realize flexible multicasting functionality. One to three, one to seven, one to thirteen and one to twenty-one multicasting are achieved without modifying OLT structure.

  3. Liver transplantation for hepatocellular carcinoma: the Hong Kong experience.

    PubMed

    Ng, Kelvin K; Lo, Chung Mau; Chan, See Ching; Chok, Kenneth S; Cheung, Tan-To; Fan, Sheung Tat

    2010-09-01

    Orthotopic liver transplantation (OLT) is the best treatment option for selected patients with hepatocellular carcinoma (HCC) with the background of cirrhosis since this treatment modality can cure both diseases at once. Over the years, the applicability of OLT for HCC has evolved. In Asia, including Hong Kong, a shortage of deceased donor liver grafts is a universal problem having to be faced in all transplant centers. Living-donor liver transplant (LDLT) has therefore been developed to counteract organ shortage and the high prevalence of HCC. The application of LDLT for HCC is a complex process involving donor voluntarism, selection criteria for the recipient and justification with respect to long-term survival in comparison to the result of deceased donor liver transplant. This article reviews the authors' experience with OLT for HCC patients in Hong Kong, with emphasis on the applicability and outcome of LDLT for HCC. Donor voluntarism has a significant impact on the application of LDLT. "Fast-track" LDLT in the setting of recurrence following curative treatment carries a high risk of recurrence even though the tumor stage fulfills the standard criteria. Although the survival outcome may be worse following LDLT than DDLT for HCC, LDLT is still the main treatment option for patients with transplantable HCC in Hong Kong, and a reasonable survival outcome can be achieved in selected patients with extended indications. It is particularly true that LDLT provides the only hope for patients with advanced HCC under the constricting problem of organ shortage.

  4. A reconfigurable all-optical VPN based on XGM effect of SOA in WDM PON

    NASA Astrophysics Data System (ADS)

    Hu, Xiaofeng; Zhang, Liang; Cao, Pan; Wang, Tao; Su, Yikai

    2010-12-01

    We propose and experimentally demonstrate a reconfigurable all-optical VPN scheme enabling intercommunications among different ONUs in a WDM PON. Reconfiguration is realized by dynamically setting wavelength conversion of optical VPN signal using a SOA in the OLT.

  5. The Influence of Task and Personality Characteristics on Employee Turnover and Absenteeism Incidents.

    DTIC Science & Technology

    1981-01-01

    E oc vc li.’ r .IIuaJry 1.981 Office of’ Nav;il Rcs,.il vh Q# ,. 4 ,lL1 , 0r4i gT...Ic It, toil ill Who, (-, o) r i n partC ~S lort’Iic L o i f. 111V llll~ of tIc Ul ilLI7 )LA . .. L: 0 I [Ile:; . Sb c ~ T c It A I 1’: 1 w1 -iid ex...UlmA ioctlt.y Vc v jn- Ilic . P’or c v i ) L c1) 1 W I S I I t’,.ItL IV e y 10r- ILI I L v J c o 1) t, )I c rflv or ind ah- - tce isi - W 4i e L

  6. Vraagstukken besmettingsbeheersing prio 3 (Questions Regarding Contamination Control, Priority 3)

    DTIC Science & Technology

    2008-11-01

    nl T +31 15 284 30 00 F +31 15 284 39 91 info-DenV@tno nl Datum nov ember 2008 Auteur (s) H.F.G. Oudmaijer Rubricering rapporl Vastgesteld door...F +31 15 284 39 91 info-DenV@tno.nl TNO-rapportnummer TNO-DV 2008 A495 Opdrachtnummer Datum november 2008 Auteur (s) H.F.G. Oudmaijer...zeep kan volgens de theorie beter vaak met een beetje water als in een keer met dezelfde totale massa water gespoeld moeten worden. Met een pH

  7. Experimental demonstration of time- and mode-division multiplexed passive optical network

    NASA Astrophysics Data System (ADS)

    Ren, Fang; Li, Juhao; Tang, Ruizhi; Hu, Tao; Yu, Jinyi; Mo, Qi; He, Yongqi; Chen, Zhangyuan; Li, Zhengbin

    2017-07-01

    A time- and mode-division multiplexed passive optical network (TMDM-PON) architecture is proposed, in which each optical network unit (ONU) communicates with the optical line terminal (OLT) independently utilizing both different time slots and switched optical linearly polarized (LP) spatial modes. Combination of a mode multiplexer/demultiplexer (MUX/DEUX) and a simple N × 1 optical switch is employed to select the specific LP mode in each ONU. A mode-insensitive power splitter is used for signal broadcast/combination between OLT and ONUs. We theoretically propose a dynamic mode and time slot assignment scheme for TMDM-PON based on inter-ONU priority rating, in which the time delay and packet loss ratio's variation tendency are investigated by simulation. Moreover, we experimentally demonstrate 2-mode TMDM-PON transmission over 10 km FMF with 10-Gb/s on-off keying (OOK) signal and direct detection.

  8. Efficacy of oral vancomycin in recurrent primary sclerosing cholangitis following liver transplantation

    PubMed Central

    Hey, Penelope; Lokan, Julie; Johnson, Paul; Gow, Paul

    2017-01-01

    Primary sclerosing cholangitis (PSC) is a liver disease that leads to progressive destruction and stricturing of the biliary tree. Unfortunately, apart from orthotopic liver transplantation (OLT), there are no universally accepted therapies to treat this disease. Even following transplantation, recurrence of PSC is seen in approximately one quarter of patients and leads to high rates of graft failure. Oral vancomycin, through possible immunomodulatory and anti-inflammatory mechanisms, has been shown in small-scale studies to be successful in improving liver function tests in patients with pretransplant PSC. We report the first case of an adult patient diagnosed with recurrent PSC 4 years after OLT who was treated with oral vancomycin leading to complete normalisation of his liver biochemistry. This case adds to the growing literature of a potential therapeutic role for this antibiotic in PSC and highlights interesting questions regarding mechanisms of disease. PMID:28951512

  9. Effect of intestinal microbiota alteration on hepatic damage in rats with acute rejection after liver transplantation.

    PubMed

    Xie, Yirui; Chen, Huazhong; Zhu, Biao; Qin, Nan; Chen, Yunbo; Li, Zhengfeng; Deng, Min; Jiang, Haiyin; Xu, Xiangfei; Yang, Jiezuan; Ruan, Bing; Li, Lanjuan

    2014-11-01

    The previous studies all focus on the effect of probiotics and antibiotics on infection after liver transplantation. Here, we focus on the effect of gut microbiota alteration caused by probiotics and antibiotics on hepatic damage after allograft liver transplantation. Brown-Norway rats received saline, probiotics, or antibiotics via daily gavage for 3 weeks. Orthotopic liver transplantation (OLT) was carried out after 1 week of gavage. Alteration of the intestinal microbiota, liver function and histopathology, serum and liver cytokines, and T cells in peripheral blood and Peyer's patch were evaluated. Distinct segregation of fecal bacterial diversity was observed in the probiotic group and antibiotic group when compared with the allograft group. As for diversity of intestinal mucosal microbiota and pathology of intestine at 2 weeks after OLT, antibiotics and probiotics had a significant effect on ileum and colon. The population of Lactobacillus and Bifidobacterium in the probiotic group was significantly greater than the antibiotic group and the allograft group. The liver injury was significantly reduced in the antibiotic group and the probiotic group compared with the allograft group. The CD4/CD8 and Treg cells in Peyer's patch were decreased in the antibiotic group. The intestinal Treg cell and serum and liver TGF-β were increased markedly while CD4/CD8 ratio was significantly decreased in the probiotic group. It suggested that probiotics mediate their beneficial effects through increase of Treg cells and TGF-β and deduction of CD4/CD8 in rats with acute rejection (AR) after OLT.

  10. An autonomous recovery mechanism against optical distribution network failures in EPON

    NASA Astrophysics Data System (ADS)

    Liem, Andrew Tanny; Hwang, I.-Shyan; Nikoukar, AliAkbar

    2014-10-01

    Ethernet Passive Optical Network (EPON) is chosen for servicing diverse applications with higher bandwidth and Quality-of-Service (QoS), starting from Fiber-To-The-Home (FTTH), FTTB (business/building) and FTTO (office). Typically, a single OLT can provide services to both residential and business customers on the same Optical Line Terminal (OLT) port; thus, any failures in the system will cause a great loss for both network operators and customers. Network operators are looking for low-cost and high service availability mechanisms that focus on the failures that occur within the drop fiber section because the majority of faults are in this particular section. Therefore, in this paper, we propose an autonomous recovery mechanism that provides protection and recovery against Drop Distribution Fiber (DDF) link faults or transceiver failure at the ONU(s) in EPON systems. In the proposed mechanism, the ONU can automatically detect any signal anomalies in the physical layer or transceiver failure, switching the working line to the protection line and sending the critical event alarm to OLT via its neighbor. Each ONU has a protection line, which is connected to the nearest neighbor ONU, and therefore, when failure occurs, the ONU can still transmit and receive data via the neighbor ONU. Lastly, the Fault Dynamic Bandwidth Allocation for recovery mechanism is presented. Simulation results show that our proposed autonomous recovery mechanism is able to maintain the overall QoS performance in terms of mean packet delay, system throughput, packet loss and EF jitter.

  11. Neutrophil extracellular traps are pathogenic in primary graft dysfunction after lung transplantation.

    PubMed

    Sayah, David M; Mallavia, Beñat; Liu, Fengchun; Ortiz-Muñoz, Guadalupe; Caudrillier, Axelle; DerHovanessian, Ariss; Ross, David J; Lynch, Joseph P; Saggar, Rajan; Ardehali, Abbas; Ware, Lorraine B; Christie, Jason D; Belperio, John A; Looney, Mark R

    2015-02-15

    Primary graft dysfunction (PGD) causes early mortality after lung transplantation and may contribute to late graft failure. No effective treatments exist. The pathogenesis of PGD is unclear, although both neutrophils and activated platelets have been implicated. We hypothesized that neutrophil extracellular traps (NETs) contribute to lung injury in PGD in a platelet-dependent manner. To study NETs in experimental models of PGD and in lung transplant patients. Two experimental murine PGD models were studied: hilar clamp and orthotopic lung transplantation after prolonged cold ischemia (OLT-PCI). NETs were assessed by immunofluorescence microscopy and ELISA. Platelet activation was inhibited with aspirin, and NETs were disrupted with DNaseI. NETs were also measured in bronchoalveolar lavage fluid and plasma from lung transplant patients with and without PGD. NETs were increased after either hilar clamp or OLT-PCI compared with surgical control subjects. Activation and intrapulmonary accumulation of platelets were increased in OLT-PCI, and platelet inhibition reduced NETs and lung injury, and improved oxygenation. Disruption of NETs by intrabronchial administration of DNaseI also reduced lung injury and improved oxygenation. In bronchoalveolar lavage fluid from human lung transplant recipients, NETs were more abundant in patients with PGD. NETs accumulate in the lung in both experimental and clinical PGD. In experimental PGD, NET formation is platelet-dependent, and disruption of NETs with DNaseI reduces lung injury. These data are the first description of a pathogenic role for NETs in solid organ transplantation and suggest that NETs are a promising therapeutic target in PGD.

  12. Neutrophil Extracellular Traps Are Pathogenic in Primary Graft Dysfunction after Lung Transplantation

    PubMed Central

    Mallavia, Beñat; Liu, Fengchun; Ortiz-Muñoz, Guadalupe; Caudrillier, Axelle; DerHovanessian, Ariss; Ross, David J.; Lynch III, Joseph P.; Saggar, Rajan; Ardehali, Abbas; Ware, Lorraine B.; Christie, Jason D.; Belperio, John A.; Looney, Mark R.

    2015-01-01

    Rationale: Primary graft dysfunction (PGD) causes early mortality after lung transplantation and may contribute to late graft failure. No effective treatments exist. The pathogenesis of PGD is unclear, although both neutrophils and activated platelets have been implicated. We hypothesized that neutrophil extracellular traps (NETs) contribute to lung injury in PGD in a platelet-dependent manner. Objectives: To study NETs in experimental models of PGD and in lung transplant patients. Methods: Two experimental murine PGD models were studied: hilar clamp and orthotopic lung transplantation after prolonged cold ischemia (OLT-PCI). NETs were assessed by immunofluorescence microscopy and ELISA. Platelet activation was inhibited with aspirin, and NETs were disrupted with DNaseI. NETs were also measured in bronchoalveolar lavage fluid and plasma from lung transplant patients with and without PGD. Measurements and Main Results: NETs were increased after either hilar clamp or OLT-PCI compared with surgical control subjects. Activation and intrapulmonary accumulation of platelets were increased in OLT-PCI, and platelet inhibition reduced NETs and lung injury, and improved oxygenation. Disruption of NETs by intrabronchial administration of DNaseI also reduced lung injury and improved oxygenation. In bronchoalveolar lavage fluid from human lung transplant recipients, NETs were more abundant in patients with PGD. Conclusions: NETs accumulate in the lung in both experimental and clinical PGD. In experimental PGD, NET formation is platelet-dependent, and disruption of NETs with DNaseI reduces lung injury. These data are the first description of a pathogenic role for NETs in solid organ transplantation and suggest that NETs are a promising therapeutic target in PGD. PMID:25485813

  13. Early viral-specific T-cell testing predicts late Cytomegalovirus reactivation following Liver Transplantation.

    PubMed

    Sood, S; Haifer, C; Yu, L; Pavlovic, J; Gow, P J; Jones, R M; Visvanathan, K; Angus, P W; Testro, A G

    2018-05-29

    Although antiviral prophylaxis is effective in preventing early cytomegalovirus (CMV) reactivation following liver transplantation (OLT), it predisposes patients to late CMV after prophylaxis has ceased. QuantiFERON-CMV (QFN-CMV, Qiagen, The Netherlands) measures an individual's viral-specific immune response. Fifty-nine OLT recipients were prospectively monitored post-OLT in an observational cohort study. QFN-CMV was performed at regular time-points. An absolute QFN-CMV <0.1IU/mL was considered non-reactive. 50/59 (84.7%) had a reactive QFN-CMV by M6. 38/59 (64.4%) had antiviral prophylaxis or treatment before M6, with 31/38 (81.6%) developing a reactive QFN-CMV by 6 months. Over 90% already had a reactive result as early as 3 months post-transplant. 3 patients (5.08%) developed late CMV between 6-12 months (median 251 days) - all had a non-reactive M6 QFN-CMV. 2/3 experienced CMV disease. Non-reactive M6 QFN-CMV was significantly associated with late CMV (OR=54.4, PPV=0.33, NPV=1.00, p=0.003). Although only 5% of recipients developed late CMV, 2/3 suffered CMV disease. M6 QFN-CMV has an excellent NPV for late CMV, suggesting patients who exhibit a robust ex-vivo immune response at M6 can safely cease CMV monitoring. Furthermore, >90% already express viral-specific immunity as early as 3 months. Conceivably, antiviral prophylaxis could be discontinued early in these patients. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  14. Epstein-Barr DNA serology and positron-emission tomography imaging of the head and neck in pediatric transplant recipients.

    PubMed

    Sidell, Douglas; Venick, Robert S; Shapiro, Nina L

    2014-05-01

    Epstein-Barr virus (EBV) infection is a potential precursor of post-transplantation lymphoproliferative disorder (PTLD) in the pediatric transplant patient. Positron-emission tomography (PET) imaging is increasingly utilized in this population to monitor for neoplasia and PTLD. We assess the association between EBV serum titers and Waldeyer's ring and cervical lymph node PET positivity in the pediatric transplant recipient. Retrospective analysis of EBV serology and PET imaging results in pediatric orthotopic liver transplantation (OLT) recipients. Imaging results and laboratory data were reviewed for all pediatric OLT recipients from January 2005 to July 2011 at a single institution. Charts were evaluated for PET positivity at Waldeyer's ring or cervical lymphatics, and for EBV serology results. Demographic data extracted include patient sex and age at transplantation. A total of 122 pediatric OLT recipients were reviewed. Twelve patients (10%) underwent PET imaging. Overall, four patients (33%) had evidence of PET positivity at Waldeyer's ring or cervical lymphatics. Five patients (42%) had positive EBV serology. There was a significant association between PET imaging results and EBV DNA serology results (P = .01). PTLD surveillance in the pediatric transplant recipient is an important component of long-term care in this population. Although PET imaging is a new modality in monitoring pediatric transplant recipients for early signs of PTLD, an association between EBV serology and PET imaging results appears to exist. With increased implementation, PET imaging will likely prove valuable in its ability to monitor the transplant recipient at risk for PTLD. © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

  15. Symptomatic osteonecrosis of the femoral head after adult orthotopic liver transplantation.

    PubMed

    Li, Hua; Zhang, Jian; He, Ji-Wen; Wang, Kun; Wang, Gen-Shu; Jiang, Nan; Fu, Bin-Sheng; Wang, Guo-Ying; Yang, Yang; Chen, Gui-Hua

    2012-07-01

    With the increase of survival in liver transplantation recipients, more patients are at a high risk of developing osteonecrosis, especially in the femoral head, due to immunosuppressive treatment. The purpose of this study was to report the incidence, possible risk factors, and outcome of symptomatic osteonecrosis of the femoral head (ONFH) in adult patients with current immunosuppressive agents and individual protocol after liver transplantation in China. A retrospective analysis was performed on 226 adult patients who underwent orthotopic liver transplantation (OLT) at a single liver transplantation institution between January 2004 and December 2008. The posttransplant survival time (or pre-retransplantation survival time) of all the patients were more than 24 months. The possible pre- and post-transplantation risk factors of symptomatic ONFH were investigated and the curative effects of the treatment were also reported. The incidence of ONFH was 1.33% in patients after OLT. ONFH occurred at a mean of (14 ± 6) months (range, 10 - 21 months) after transplantation. Male patients more often presented with osteonecrosis as a complication than female patients. The patients with lower pre-transplantation total bilirubin and direct bilirubin levels (P < 0.05). There was no difference in the cumulative dose of corticosteroids or tacrolimus between the patients with or without symptomatic ONFH. Patients were treated either pharmacologically or surgically. All patients showed a nice curative effect without major complications during the 18 - 63 months post-treatment follow up. The symptomatic ONFH does not occur commonly after adult OLT in the current individual immunosuppressive protocol in China.

  16. Coherent UDWDM PON with joint subcarrier reception at OLT.

    PubMed

    Kottke, Christoph; Fischer, Johannes Karl; Elschner, Robert; Frey, Felix; Hilt, Jonas; Schubert, Colja; Schmidt, Daniel; Wu, Zifeng; Lankl, Berthold

    2014-07-14

    In this contribution, we report on the experimental investigation of an ultra-dense wavelength-division multiplexing (UDWDM) upstream link with up to 700 × 2.488 Gb/s polarization-division multiplexing differential quadrature phase-shift keying parallel upstream user channels transmitted over 80 km of standard single-mode fiber. We discuss challenges of the digital signal processing in the optical line terminal arising from the joint reception of several upstream user channels. We present solutions for resource and cost-efficient realization of the required channel separation, matched filtering, down-conversion and decimation as well as realization of the clock recovery and polarization demultiplexing for each individual channel.

  17. 300 Gb/s IM/DD based SDM-WDM-PON with laserless ONUs.

    PubMed

    Bao, Fangdi; Morioka, Toshio; Oxenløwe, Leif K; Hu, Hao

    2018-04-02

    A low-cost, high-speed SDM-WDM-PON architecture is proposed by using a multi-core fiber (MCF) and intensity modulation/directly detection (IM/DD). One of the MCF cores is used for sending laser sources from optical line terminal (OLT) to optical network unit (ONU), thus facilitating laserless and colorless ONUs, and providing ease of network management and maintenance. In addition, the wavelengths of the ONUs are controlled on the OLT side, which also enables flexible optical networks. Thanks to the low inter-core crosstalk of a MCF, downstream (DS) and upstream (US) signals are transmitted independently in different cores of the MCF, not only increasing the aggregated capacity but also avoiding the Rayleigh backscattering noise. Finally, a proof-of-principle experiment is performed by using a 7-core fiber, achieving 300 /120 Gb/s aggregated capacity for DS and US (3 × cores, 4 × wavelengths, 25/10 Gb/s per wavelength), respectively.

  18. De-optical-line-terminal hybrid access-aggregation optical network for time-sensitive services based on software-defined networking orchestration

    NASA Astrophysics Data System (ADS)

    Bai, Wei; Yang, Hui; Xiao, Hongyun; Yu, Ao; He, Linkuan; Zhang, Jie; Li, Zhen; Du, Yi

    2017-11-01

    With the increase in varieties of services in network, time-sensitive services (TSSs) appear and bring forward an impending need for delay performance. Ultralow-latency communication has become one of the important development goals for many scenarios in the coming 5G era (e.g., robotics and driverless cars). However, the conventional methods, which decrease delay by promoting the available resources and the network transmission speed, have limited effect; a new breakthrough for ultralow-latency communication is necessary. We propose a de-optical-line-terminal (De-OLT) hybrid access-aggregation optical network (DAON) for TSS based on software-defined networking (SDN) orchestration. In this network, low-latency all-optical communication based on optical burst switching can be achieved by removing OLT. For supporting this network and guaranteeing the quality of service for TSSs, we design SDN-driven control method and service provision method. Numerical results demonstrate the proposed DAON promotes network service efficiency and avoids traffic congestion.

  19. Effect of mouth cleaning with hinokitiol-containing gel on oral malodor: a randomized, open-label pilot study.

    PubMed

    Iha, Kosaku; Suzuki, Nao; Yoneda, Masahiro; Takeshita, Toru; Hirofuji, Takao

    2013-10-01

    The aim of the study was to evaluate the effect of mouth cleaning with hinokitiol-containing gel on oral malodor. An open-label, randomized, controlled trial was conducted to assess oral malodor and clinical parameters related to oral malodor before and after mouth cleaning with hinokitiol-containing gel (n = 9) or with gel not including hinokitiol (n = 9). Mouth cleaning included the teeth, gingiva, and tongue and was carried out 3 times per day for 4 weeks. Organoleptic test (OLT) scores (P = .021), levels of hydrogen sulfide (P = .008) and methyl mercaptan (P = .020), frequency of bleeding on probing, average probing pocket depth, and plaque index significantly improved in the group using hinokitiol. In contrast, only the OLT score (P = .031) significantly improved in the control group after the treatment regimen. Mouth cleaning with hinokitiol-containing gel may be effective for reduction of oral malodor. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. U.S. EPA, Pesticide Product Label, FRUIT BUILDER'S FISH OIL PESTICIDE/STICKER-SPREADER, 11/06/1981

    EPA Pesticide Factsheets

    2011-04-21

    ... 'E;'<1 .... : f''':.l ':, • 'l I,) ,Ih':i I:, th •. (~"I:"L'd t!:,..rl,;,]nt ~ldge of l)lLJ d·. Jt'icprnt..!It ,)! tll'~ ute of IL) ,) iLl" ·n~, ;)1 Olt I'f" 'I' J.JI!,Jr': .. 'j' .... n (j hi! ...

  1. Hydrometeor Data and Analytical-Theoretical Investigations Pertaining to the SAMS Rain Erosion Program of the 1972-73 Season at Wallops Island, Virginia - AFGL/SAMS Report Number 5

    DTIC Science & Technology

    1977-07-05

    Report No.5 1. INTRODUCTION The liquid-water-content values and other associated hydrometeorological information for the trajectories of the SAMS...Map Showin« Sitini; Locations of Rain ( Jauges and Oisdrometers Relative to the Missile Launch Pads 80 OltOftOMCTCR I |"fy/^n ^J^^^^^ 01 J I

  2. Exploring Staff Perceptions: Early Childhood Teacher Educators Examine Online Teaching and Learning Challenges and Dilemmas

    ERIC Educational Resources Information Center

    Davis, Julie; Lennox, Sandra; Walker, Sue; Walsh, Kerryann

    2007-01-01

    Early Childhood teacher educators at Queensland University of Technology (QUT) have been engaging with online teaching and learning since the mid 1990s. On campus students have lectures and tutorials supported by information and communication technologies via QUT's home grown learning management system, Online Learning and Teaching (OLT). We…

  3. Designing Journalism Capstone Units That Demonstrate Student Skills

    ERIC Educational Resources Information Center

    Cullen, Trevor

    2016-01-01

    There are considerable differences in the structure, content, and delivery of tertiary journalism degrees in Australia as identified in a 2014 Office for Learning and Teaching (OLT) Innovation and Development Project report on graduate qualities and journalism curriculum renewal. To address this situation, the author argues for journalism capstone…

  4. Natural History of Cirrhosis of Liver after First Decompensation: A Prospective Study in India.

    PubMed

    Shah, Apurva S; Amarapurkar, Deepak N

    2018-03-01

    As liver cirrhosis is a dynamic condition, it is possible to improve survival in decompensated cirrhosis. Hence, we planned a prospective study to determine the natural history of cirrhosis after first decompensation. We enrolled all patients of liver cirrhosis who presented with first episode of decompensation defined by the presence of ascites, either overt or detected by Ultrasonography (UD), Gastroesophageal Variceal Bleeding (GEVB), and Hepatic Encephalopathy (HE). All patients were followed up to death/liver transplant or at least for the period of 1 year. Multivariable Cox proportional hazards regression was used to analyze the risk of failure (death or Orthotopic Liver Transplantation (OLT)). In total of 110 cirrhotic patients (93 males, mean age 50 ± 11 years), the most frequent etiology was alcohol (48%), followed by nonalcoholic steatohepatitis/cryptogenic (26%), hepatitis B (10%), autoimmune hepatitis (7%), and hepatitis C (6%). The distribution of CTP classes was: 4%, 56%, and 41% in class A, B, and C, respectively. Ascites was the most common decompensation found in 88 patients (80%) followed by HE (14%) and GEVB (6%). At 1-year follow up, transplant free survival was 78%, 2 underwent OLT, 4 developed hepatocellular carcinoma, and 24 died. Cumulative incidence of failure (death or OLT) by type of decompensation after 1 year was: 22% overt ascites, 50% GEVB, 28% UD ascites, 20% HE, and 33% ascites and GEVB concomitant. Patients with UD ascites do not have a negligible mortality rate as compared to overt ascites. Patients with cirrhosis after first decompensation have better transplant free survival with treatment of etiology and complications than previously mentioned in literature.

  5. CXCR3+CD4+ T cells mediate innate immune function in the pathophysiology of liver ischemia/reperfusion injury.

    PubMed

    Zhai, Yuan; Shen, Xiu-da; Hancock, Wayne W; Gao, Feng; Qiao, Bo; Lassman, Charles; Belperio, John A; Strieter, Robert M; Busuttil, Ronald W; Kupiec-Weglinski, Jerzy W

    2006-05-15

    Ischemia-reperfusion injury (IRI), an innate immune-dominated inflammatory response, develops in the absence of exogenous Ags. The recently highlighted role of T cells in IRI raises a question as to how T lymphocytes interact with the innate immune system and function with no Ag stimulation. This study dissected the mechanism of innate immune-induced T cell recruitment and activation in rat syngeneic orthotopic liver transplantation (OLT) model. Liver IRI was induced after cold storage (24-36 h) at 4 degrees C in University of Wisconsin solution. Gene products contributing to IRI were identified by cDNA microarray at 4-h posttransplant. IRI triggered increased intrahepatic expression of CXCL10, along with CXCL9 and 11. The significance of CXCR3 ligand induction was documented by the ability of neutralizing anti-CXCR3 Ab treatment to ameliorate hepatocellular damage and improve 14-day survival of 30-h cold-stored OLTs (95 vs 40% in controls; p < 0.01). Immunohistology analysis confirmed reduced CXCR3+ and CD4+ T cell infiltration in OLTs after treatment. Interestingly, anti-CXCR3 Ab did not suppress innate immune activation in the liver, as evidenced by increased levels of IL-1beta, IL-6, inducible NO synthase, and multiple neutrophil/monokine-targeted chemokine programs. In conclusion, this study demonstrates a novel mechanism of T cell recruitment and function in the absence of exogenous Ag stimulation. By documenting that the execution of innate immune function requires CXCR3+CD4+ T cells, it highlights the critical role of CXCR3 chemokine biology for the continuum of innate to adaptive immunity in the pathophysiology of liver IRI.

  6. Adverse events affect sorafenib efficacy in patients with recurrent hepatocellular carcinoma after liver transplantation: experience at a single center and review of the literature.

    PubMed

    Zavaglia, Claudio; Airoldi, Aldo; Mancuso, Andrea; Vangeli, Marcello; Viganò, Raffaella; Cordone, Gabriella; Gentiluomo, Maria; Belli, Luca Saverio

    2013-02-01

    The aim of this study was to assess the safety and efficacy of sorafenib, with or without everolimus, in the treatment of recurrent hepatocellular carcinoma (HCC) after an orthotopic liver transplantation (OLT). We reviewed the outcome of our consecutive cohort series of patients. Eleven patients (nine men) with recurrent HCC after OLT were treated. Four patients received cyclosporine plus sorafenib at a starting dose of 400 mg twice daily; seven received the combination of sorafenib (same dosage) and everolimus. Sorafenib was reduced or stopped according to the drug label. The median time to recurrence was 12 months (range 2-66). The mean age at the start of treatment was 57 ± 9 years. Sorafenib was withdrawn because of intolerance or side-effects in four (36%) patients. Dose reduction because of adverse events or intolerance was required in 91% of patients after 26 ± 11 days from the start of treatment. The average length of treatment was 68 days (range 15-444). One patient died because of a massive gastrointestinal bleeding while receiving sorafenib and everolimus. The most frequent adverse events were fatigue (54%), skin toxicity (45%), and hypophosphatemia (36%). Two patients (18%) showed a radiological partial response, one (9%) had a stable disease, and six (54%) showed a progressive disease. None of the patients achieved a complete response. Treatment response could not be assessed in two (18%) patients. The overall median survival since the start of treatment was 5 months. One-year survival was 18%. Sorafenib, with or without mammalian target of rapamycin inhibitors, is poorly tolerated and rarely effective in the treatment of recurrent HCC after OLT.

  7. Clinical impact and efficacy of lamivudine therapy in de novo hepatitis B infection after liver transplantation.

    PubMed

    Castells, Lluís; Vargas, Víctor; Rodríguez, Francisco; Allende, Helena; Buti, Maria; Sánchez-Avila, José F; Jardí, Rosendo; Margarit, Carlos; Pumarola, Tomás; Esteban, Rafael; Guardia, Jaime

    2002-10-01

    De novo hepatitis B virus (HBV) infection after orthotopic liver transplantation (OLT) in patients negative for hepatitis B surface antigen (HBsAg) is between 1.7% and 3.5% in areas with a low prevalence of HBV infection. The importance of this problem and the efficacy of lamivudine treatment has not been defined in areas with a high prevalence of positivity to antibody to hepatitis B core antigen (Anti-HBc). To define the characteristics and the clinical impact of de novo HBV infection in OLT recipients and to evaluate the efficacy of lamivudine treatment in this context, 229 HBsAg (-) donors (145 men, 84 women) were retrospectively evaluated between June 1994 and June 2000. Forty-eight recipients were excluded for various reasons. The final study population included 181 patients that were prospectively followed up for more than 6 months after OLT. When de novo HBV infection was detected, liver allograft biopsy was performed and treatment with lamivudine was indicated if patients were HBV-DNA-positive with elevated ALT levels. Survival time was defined as the interval between diagnosis of HBV infection and death or last follow-up visit. Thirty-one of 229 liver donors (13.5%) were anti-HBc(+). After a mean follow-up of 54.4+/-30 months, 9 of the 181 recipients (5%) developed de novo HBV infection; 8 of 27 recipients (29.6%) of livers from anti-HBc(+) donors as compared with only one of 154 recipients (0.6%) of livers from anti-HBc(-) donors P < 0.005). Liver biopsies performed in 8 of 9 cases showed chronic active hepatitis in 7 patients and acute hepatitis in one patient who cleared HBV spontaneously during the first 3 months. Seven patients were treated with lamivudine for a mean period of 24.5 months; HBV-DNA became negative in 5 of 7 (71.4%), and HBeAg became undetectable in 3 of 6 patients (50%). Patient actuarial survival rates at 1, 3, and 5 years were 100%, 94.7%, and 81.2% for recipients of anti-HBc (+) livers and 95.2%, 83%, and 77.3% for recipients of

  8. The Effects of Aerodynamic Heating and Heat Transfer on the Surface Temperature of a Body of Revolution in Steady Supersonic Flight

    DTIC Science & Technology

    1947-07-01

    HF..-I.T THA.:\\SFER 0.:\\ THE SnlfACE TDJPER.Hl’RE Of ... BODY OF RE’·OLt·TIO.:\\ 471 o~~---~~~--~~~~~--~~~~--~ 1.2 1.6 2.0 2,4 2.8 3.2 Moch number

  9. Engineering of a multi-station shoulder simulator.

    PubMed

    Smith, Simon L; Li, Lisa; Joyce, Thomas J

    2016-05-01

    This work aimed to engineer a multi-station shoulder simulator in order to wear test shoulder prostheses using recognized shoulder activities of daily living. A bespoke simulator was designed, built and subject to commissioning trials before a first wear test was conducted. Five JRI Orthopaedics Reverse Shoulder VAIOS 42 mm prostheses were tested for 2.0 million cycles and a mean wear rate and standard deviation of 14.2 ± 2.1 mm(3)/10(6) cycles measured for the polymeric glenoid components. This result when adjusted for prostheses diameters and test conditions showed excellent agreement with results from hip simulator studies of similar materials in a lubricant of bovine serum. The Newcastle Shoulder Simulator is the first multi-station shoulder simulator capable of applying physiological motion and loading for typical activities of daily living. © IMechE 2016.

  10. Permafrost and organic layer interactions over a climate gradient in a discontinuous permafrost zone

    Treesearch

    Kristofer D. Johnson; Jennifer W. Harden; A. David McGuire; Mark Clark; Fengming Yuan; Andrew O. Finley

    2013-01-01

    Permafrost is tightly coupled to the organic soil layer, an interaction that mediates permafrost degradation in response to regional warming. We analyzed changes in permafrost occurrence and organic layer thickness (OLT) using more than 3000 soil pedons across a mean annual temperature (MAT) gradient. Cause and effect relationships between permafrost probability (PF),...

  11. "Bush Law 101": Realising Place Conscious Pedagogy in the Law Curriculum

    ERIC Educational Resources Information Center

    Kennedy, Amanda; Mundy, Trish; Nielsen, Jennifer M.

    2016-01-01

    In 2012, a team of academics from six universities worked on an OLT-funded project, "Rethinking Law Curriculum: developing strategies to prepare law graduates for practice in rural and regional Australia." The project was motivated by the declining proportion of lawyers being attracted to and remaining in practice in rural and regional…

  12. CS-10 Verification Survey at Former McClellan AFB, Sacramento, CA

    DTIC Science & Technology

    2013-09-26

    8217!11C’D ./ -k~>olY 3ə ’-Af" 4 \\I Olt te’o Q__li~\\ (G"d.07y r ,~ ’illi’ 󈧏󈧓 ’>, - c;;¥a’f’’i c""" I 16 Distribution A: Approved for public release

  13. Postschool Goals and Transition Services for Students with Learning Disabilities

    ERIC Educational Resources Information Center

    Daviso, Alfred W.; Denney, Stephen C.; Baer, Robert M.; Flexer, Robert

    2011-01-01

    This article describes the initial findings for students with learning disabilities from the first year of The Ohio Longitudinal Transition Study (OLTS). The study included 416 participants with learning disabilities who were exiting high school. Data from an in-school survey were analyzed by sample demographics (e.g. school setting, school type,…

  14. Waupaca Foundry, Inc. Plant No.5

    EPA Pesticide Factsheets

    2015-09-10

    ... y 2 ,Qt:;" qq_, s- 2.0'J'"' 99, R" ·~ ~.0) /Olt ? I. 9 0 II I. '2 It' 8' I. ffj lr~rr q ., ?~ 1/(.C /0 /.10 IZ2 ' ... I (.., 67 r II '"';9( 1 i , II 8 I ' q. c-=r;.. '-t r 177 'I 6. l, 6 ;- ) -- ...

  15. Response to Dietary Oxalate after Bariatric Surgery

    PubMed Central

    Froeder, Leila; Arasaki, Carlos Haruo; Malheiros, Carlos Alberto; Baxmann, Alessandra Calábria

    2012-01-01

    Summary Background and objectives Bariatric surgery (BS) may be associated with increased oxalate excretion and a higher risk of nephrolithiasis. This study aimed to investigate urinary abnormalities and responses to an acute oxalate load as an indirect assessment of the intestinal absorption of oxalate in this population. Design, setting, participants, & measurements Twenty-four–hour urine specimens were collected from 61 patients a median of 48 months after BS (post-BS) as well as from 30 morbidly obese (MO) participants; dietary information was obtained through 24-hour food recalls. An oral oxalate load test (OLT), consisting of 2-hour urine samples after overnight fasting and 2, 4, and 6 hours after consuming 375 mg of oxalate (spinach juice), was performed on 21 MO and 22 post-BS patients 12 months after BS. Ten post-BS patients also underwent OLT before surgery (pre-BS). Results There was a higher percentage of low urinary volume (<1.5 L/d) in post-BS versus MO (P<0.001). Hypocitraturia and hyperoxaluria (P=0.13 and P=0.36, respectively) were more frequent in BS versus MO patients. The OLT showed intragroup (P<0.001 for all periods versus baseline) and intergroup differences (P<0.001 for post-BS versus MO; P=0.03for post-BS versus pre-BS). The total mean increment in oxaluria after 6 hours of load, expressed as area under the curve, was higher in both post-BS versus MO and in post-BS versus pre-BS participants (P<0.001 for both). Conclusions The mean oxaluric response to an oxalate load is markedly elevated in post-bariatric surgery patients, suggesting that increased intestinal absorption of dietary oxalate is a predisposing mechanism for enteric hyperoxaluria. PMID:23024163

  16. Magnetic ring anastomosis of suprahepatic vena cava: novel technique for liver transplantation in rat.

    PubMed

    Shi, Yuan; Zhang, Wei; Deng, Yong-lin; Zhang, Ya-min; Zhang, Quan-sheng; Zhang, Wei-ye; Zheng, Hong; Pan, Cheng; Shen, Zhong-Yang

    2015-01-01

    To improve the technique of suprahepatic vena cava (SHVC) reconstruction in rat OLT, novel magnetic rings were designed and manufactured to facilitate reconstruction of SHVC and shorten the anhepatic time. One-hundred and twenty adult male Wistar rats were randomly divided into two groups: rings group (n = 30), using magnetic rings for SHVC reconstruction; suture group (n = 30), 7/0 prolene suture was used for SHVC running anastomosis as control. Cuff techniques were used for portal vein and infrahepatic vena cava reconstruction as Kamada and Calne described. The bile duct was reconnected with a stent. The hepatic re-arterialization was omitted. In the rings group, the SHVC reconstruction took 0.91 ± 0.24 (mean ± SD) min; the anhepatic phase and the recipient operation time were 5.63 ± 0.65 min and 36.02 ± 8.02 min, respectively. In suture group, the anastomotic time of SHVC was 10.40 ± 2.11 min; the anhepatic phase and the recipient operation time were 17.76 ± 2.51 and 49.38 ± 12.06 min, respectively, and there was statistically significant difference between the two groups. The ALT levels reached peak at 24 h post-OLT (186.2 ± 32.5 IU/l) and restored to normal level at 96 h gradually. In the rings group, 29 of 30 rats survived at day 7 and 28 of 30 rats survived at day 30. In contrast, only 25 of 30 recipients in suture group remained alive at day 7 and 22 of 30 remained alive at day 30 (P < 0.05). Better anastomotic healing was founded in rings group by pathology and scanning electron microscope. The magnetic rings technique provides a novel, simple method for SHVC reconstruction of OLT in rat. It significantly shortens anhepatic phase, while the success rate of the operation is satisfactory. © 2014 Steunstichting ESOT.

  17. Impact of N-acetylcysteine on the hepatic microcirculation after orthotopic liver transplantation.

    PubMed

    Koeppel, T A; Lehmann, T G; Thies, J C; Gehrcke, R; Gebhard, M M; Herfarth, C; Otto, G; Post, S

    1996-05-15

    Recent observations showed an improvement of hepatic macro- and microhemodynamics as well as survival rates after warm ischemia of the liver following treatment with N-acetylcysteine (NAC). In this study we assessed the influence of NAC on the hepatic microcirculation after orthotopic liver transplantation (OLT) using intravital fluorescence microscopy. OLT with simultaneous arterialization was performed in 16 male Lewis rats following cold storage in University of Wisconsin solution for 24 hr. Within the experimental group (n = 8) donors received NAC (400 mg/kg) 25 min before hepatectomy. In addition, high-dose treatment of recipients with NAC (400 mg/kg) was started with reperfusion. Control animals (n = 8) received an equivalent amount of Ringer's solution. Intravital fluorescence microscopy was performed 30-90 min after reperfusion assessing acinar and sinusoidal perfusion, leukocyte-endothelium interaction, and phagocytic activity. Treatment with NAC reduced the number of nonperfused sinusoid from 52.4 +/- 0.8% to 15.7 +/- 0.5% (p = 0.0001) (mean +/- SEM). Furthermore, we achieved a significant reduction of leukocytes adhering to sinusoidal endothelium (per mm2 liver surface) from 351.9 +/- 13.0 in controls to 83.6 +/- 4.2 in the experimental group (P = 0.0001). In postsinusoidal venules, treatment with NAC decreased the number of sticking leukocytes (per mm2 endothelium) from 1098.5 +/- 59.6 to 425.9 +/- 37.7 (P = 0.0001). Moreover, bile flow was significantly increased after therapy with NAC (4.3 +/- 1.2 vs. 2.2 +/- 0.7 ml/90 min x 100g liver) (P < 0.05). Phagocytic activity was not influenced by application of NAC. We conclude that high-dose therapy with NAC in OLT attenuates manifestations of microvascular perfusion failure early after reperfusion and should be considered as a means to reduce reperfusion injury.

  18. Intraoperative Portal Flow of Less Than 1 Liter per Minute After Orthotopic Liver Transplantation Is Not Associated Per Se With an Increased Rate of Early Graft Dysfunction.

    PubMed

    Gastaca, M; Prieto, M; Valdivieso, A; Ruiz, P; Ventoso, A; Palomares, I; Matarranz, A; Martinez-Indart, L; Ortiz de Urbina, J

    2016-09-01

    The aim of this study was to determine whether a portal flow of <1,000 mL/min in orthotopic liver transplantation (OLT) is associated with a higher incidence of early graft dysfunction (EGD) and graft loss. A retrospective study was performed of 540 OLTs carried out consecutively from December 2004 to December 2013. Patients were divided into 2 groups: group A, portal flow <1,000 mL/min; and group B, portal flow >1,000 mL/min. We studied the incidence of EGD and graft survival. A subanalysis was performed to define the minimum acceptable portal flow/100 g of liver weight to reduce the development EGD and graft loss. Group A included 29 patients and group B, 511 patients. Group A had significantly lower-weight donors and recipients, female recipients with cholestatic disease, lower MELD scores, and lower hepatic artery flow. EGD occurred in 7 patients in group A (24.1%) versus 101 patients in group B (19.8%; P = .43). No significant differences were found in 1- and 5-year graft survival. A portal flow of <80 mL/min/100 g of liver weight was related to a significantly higher risk of developing EGD (odds ratio, 4.35; 95% confidence interval [CI], 1.46-12.91; P = .008) and graft loss (hazard ratio, 4.05; 95% CI, 1.32-12.42; P = .014). Intraoperative portal flow of <1,000 mL/min in OLT was not related per se with a higher incidence of EGD or graft loss. Significantly higher risk of developing EGD and graft loss was associated with a portal flow of <80 mL/min/100 g of liver weight. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Comparison of the WarmCloud and Bair Hugger Warming Devices for the Prevention of Intraoperative Hypothermia in Patients Undergoing Orthotopic Liver Transplantation: A Randomized Clinical Trial

    PubMed Central

    Pearce, Brett; Mattheyse, Linda; Ellard, Louise; Desmond, Fiona; Pillai, Param; Weinberg, Laurence

    2018-01-01

    Background The avoidance of hypothermia is vital during prolonged and open surgery to improve patient outcomes. Hypothermia is particularly common during orthotopic liver transplantation (OLT) and associated with undesirable physiological effects that can adversely impact on perioperative morbidity. The KanMed WarmCloud (Bromma, Sweden) is a revolutionary, closed-loop, warm-air heating mattress developed to maintain normothermia and prevent pressure sores during major surgery. The clinical effectiveness of the WarmCloud device during OLT is unknown. Therefore, we conducted a randomized controlled trial to determine whether the WarmCloud device reduces hypothermia and prevents pressure injuries compared with the Bair Hugger underbody warming device. Methods Patients were randomly allocated to receive either the WarmCloud or Bair Hugger warming device. Both groups also received other routine standardized multimodal thermoregulatory strategies. Temperatures were recorded by nasopharyngeal temperature probe at set time points during surgery. The primary endpoint was nasopharyngeal temperature recorded 5 minutes before reperfusion. Secondary endpoints included changes in temperature over the predefined intraoperative time points, number of patients whose nadir temperature was below 35.5°C and the development of pressure injuries during surgery. Results Twenty-six patients were recruited with 13 patients randomized to each group. One patient from the WarmCloud group was excluded because of a protocol violation. Baseline characteristics were similar. The mean (standard deviation) temperature before reperfusion was 36.0°C (0.7) in the WarmCloud group versus 36.3°C (0.6) in the Bairhugger group (P = 0.25). There were no statistical differences between the groups for any of the secondary endpoints. Conclusions When combined with standardized multimodal thermoregulatory strategies, the WarmCloud device does not reduce hypothermia compared with the Bair Hugger device in

  20. Scalable Active Optical Access Network Using Variable High-Speed PLZT Optical Switch/Splitter

    NASA Astrophysics Data System (ADS)

    Ashizawa, Kunitaka; Sato, Takehiro; Tokuhashi, Kazumasa; Ishii, Daisuke; Okamoto, Satoru; Yamanaka, Naoaki; Oki, Eiji

    This paper proposes a scalable active optical access network using high-speed Plumbum Lanthanum Zirconate Titanate (PLZT) optical switch/splitter. The Active Optical Network, called ActiON, using PLZT switching technology has been presented to increase the number of subscribers and the maximum transmission distance, compared to the Passive Optical Network (PON). ActiON supports the multicast slot allocation realized by running the PLZT switch elements in the splitter mode, which forces the switch to behave as an optical splitter. However, the previous ActiON creates a tradeoff between the network scalability and the power loss experienced by the optical signal to each user. It does not use the optical power efficiently because the optical power is simply divided into 0.5 to 0.5 without considering transmission distance from OLT to each ONU. The proposed network adopts PLZT switch elements in the variable splitter mode, which controls the split ratio of the optical power considering the transmission distance from OLT to each ONU, in addition to PLZT switch elements in existing two modes, the switching mode and the splitter mode. The proposed network introduces the flexible multicast slot allocation according to the transmission distance from OLT to each user and the number of required users using three modes, while keeping the advantages of ActiON, which are to support scalable and secure access services. Numerical results show that the proposed network dramatically reduces the required number of slots and supports high bandwidth efficiency services and extends the coverage of access network, compared to the previous ActiON, and the required computation time for selecting multicast users is less than 30msec, which is acceptable for on-demand broadcast services.

  1. [Orthotopic liver transplantation in adult patients with cadaveric grafts. Experience of the Fundeni Center of General Surgery and Liver Transplantation].

    PubMed

    Popescu, I; Ionescu, M; Tulbure, D; Ciurea, S; Băilă, S; Braşoveanu, V; Hrehoreţ, D; Sârbu-Boeţi, P; Pietrăreanu, D; Alexandrescu, S; Dorobanţu, B; Gheorghe, L; Gheorghe, C; Mihăilă, M; Boroş, M; Croitoru, M; Herlea, V

    2005-01-01

    We analyze the experience of the Center of General Surgery and Liver Transplantation from the Fundeni Clinical Institute (Bucharest, Romania) regarding orthotopic liver transplantation (OLT) in adult recipients, with whole liver grafts from cadaveric donors, between April 2000 (when the first successful LT was performed in Romania) and December 2004. This series includes 37 OLTs in adult recipients (16 women and 21 men, aged between 29-57 years--average 46 years). Other two LT with whole liver cadaveric grafts and two reduced-size LT were performed in children; also, in the same period, due to the acute organ shortage, other methods of LT were performed in 28 patients (21 living donor LT, 6 split LT and one "do mino" LT), that were not included in the present series. The indications for OLT were HBV cirrhosis--10, HBV+HDV cirrhosis--4, HCV cirrhosis--11, HBV+HCV cirrhosis--2, biliary cirrhosis--5, Wilson disease--2, alcoholic cirrhosis--1, non-alcoholic liver disease--1, autoimmune cirrhosis--1. With three exceptions, in which the classical transplantation technique was used, the liver was grafted following the technique described by Belghiti. Local postoperative complications occurred in 15 patients (41%) and general complications in 17 (46%); late complications were registered in 18 patients (49%) and recurrence of the initial disease in 6 patients (16%). Intrao- and postoperative mortality was 8% (3/37). There were two patients (5%) who died because of immunosuppressive drug neurotoxicity at more than 30 days following LT. Four patients (11%) died lately because of PTLD, liver venoocclusive disease, recurrent autoimmune hepatitis and liver venoocclusive disease, myocardial infarction, respectively. Thirty-four patients survived the postoperative period (92%); according to Kaplan-Meier analysis, actuarial patient-survival rate at month 31 was 75%.

  2. The Impact of Fire on Active Layer Thicknes

    NASA Astrophysics Data System (ADS)

    Schaefer, K. M.; Parsekian, A.; Natali, S.; Ludwig, S.; Michaelides, R. J.; Zebker, H. A.; Chen, J.

    2016-12-01

    Fire influences permafrost thermodynamics by darkening the surface to increase solar absorption and removing insulating moss and organic soil, resulting in an increase in Active Layer Thickness (ALT). The summer of 2015 was one of the worst fire years on record in Alaska with multiple fires in the Yukon-Kuskokwim (YK) Delta. To understand the impacts of fire on permafrost, we need large-scale, extensive measurements of ALT both within and outside the fire zones. In August 2016, we surveyed ALT across multiple fire zones in the YK Delta using Ground Penetrating Radar (GPR) and mechanical probing. GPR uses pulsed, radio-frequency electromagnetic waves to noninvasively image the subsurface and is an effective tool to quickly map ALT over large areas. We supplemented this ALT data with measurements of Volumetric Water Content (VWC), Organic Layer Thickness (OLT), and burn severity. We quantified the impacts of fire by statistically comparing the measurements inside and outside the fire zones and statistically regressing ALT against VWC, change in OLT, and burn severity.

  3. Efficacy of oral vancomycin in recurrent primary sclerosing cholangitis following liver transplantation.

    PubMed

    Hey, Penelope; Lokan, Julie; Johnson, Paul; Gow, Paul

    2017-09-25

    Primary sclerosing cholangitis (PSC) is a liver disease that leads to progressive destruction and stricturing of the biliary tree. Unfortunately, apart from orthotopic liver transplantation (OLT), there are no universally accepted therapies to treat this disease. Even following transplantation, recurrence of PSC is seen in approximately one quarter of patients and leads to high rates of graft failure. Oral vancomycin, through possible immunomodulatory and anti-inflammatory mechanisms, has been shown in small-scale studies to be successful in improving liver function tests in patients with pretransplant PSC. We report the first case of an adult patient diagnosed with recurrent PSC 4 years after OLT who was treated with oral vancomycin leading to complete normalisation of his liver biochemistry. This case adds to the growing literature of a potential therapeutic role for this antibiotic in PSC and highlights interesting questions regarding mechanisms of disease. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  4. Valuing the Leadership Role of University Unit Coordinators

    ERIC Educational Resources Information Center

    Pepper, Coral; Roberts, Susan

    2016-01-01

    In this paper we describe the experiences of 64 unit coordinators across 15 Australian universities, gathered during 2011/2012 as part of an Office for Learning and Teaching (OLT) project. Our intention was to gain insight into how unit coordinators (academics who coordinate a discrete unit of study) perceive their role as leaders of learning in…

  5. An enhanced DWBA algorithm in hybrid WDM/TDM EPON networks with heterogeneous propagation delays

    NASA Astrophysics Data System (ADS)

    Li, Chengjun; Guo, Wei; Jin, Yaohui; Sun, Weiqiang; Hu, Weisheng

    2011-12-01

    An enhanced dynamic wavelength and bandwidth allocation (DWBA) algorithm in hybrid WDM/TDM PON is proposed and experimentally demonstrated. In addition to the fairness of bandwidth allocation, this algorithm also considers the varying propagation delays between ONUs and OLT. The simulation based on MATLAB indicates that the improved algorithm has a better performance compared with some other algorithms.

  6. Finding the Sweet Spot: Bridging X3D, S1000D, and SCORM for Embedded Performance Assessment and Life Cycle Training Content Management

    DTIC Science & Technology

    2010-07-14

    f\\11 eL1&iled.i’m:COilPI: Io) d< olt <llllllt e\\’CDI: re<ci\\oifi’Om XJD KCD!: f71 10Ucl!C«~~~:ItttO nl’liTOIIdledAI (I’R.ooicnRes>ocl t\\’t:U r«d\\’ed

  7. Think tank (2) Its development and the current situation of the key organizations in Japan

    NASA Astrophysics Data System (ADS)

    Obara, Michio

    There were some think tank businesses in Japan before the war. South Manchuria Railway Company established its Research Department for the purpose of getting power to control Manchuria as a colony, and got the good results. Think tank business was flourishing three times after the war. This business attracts much attention when the social and economic paradigm is going to change. Among the key large-scale think tanks in Japan, Nomura Research Institute, Ltd. (NRI) was the first to enhance the system functions by the merger, and posted think tank function up in the SI business. Mitsubishi Research Institute, Inc. (MRI) intends to be an orthodox think tank, and established an advanced research institute and the laboratory for R&D. Daiwa Institute of Research, Ltd. (DIR) focuses on economic forecast by using system. Fuji Research Institute. Corp. (FUJI RIC) focuses on survey and policy proposing in macro-economics, and analyzing technology. The Japan Research Institute, Ltd. (JRI) focuses on regional development, and R&D in advanced technology.

  8. Think tank (3) - Present activities of other representative organizations

    NASA Astrophysics Data System (ADS)

    Obara, Michio

    There were some think tank businesses in Japan before the war. South Manchuria Railway Company established its Research Department for the purpose of getting power to control Manchuria as a colony, and got the good results. Think tank business was flourishing three times after the war. This business attracts much attention when the social and economic paradigm is going to change. Among the key large-scale think tanks in Japan, Nomura Research Institute, Ltd. (NRI) was the first to enhance the system functions by the merger, and posted think tank function up in the SI business. Mitsubishi Research Institute, Inc. (MRI) intends to be an orthodox think tank, and established an advanced research institute and the laboratory for R&D. Daiwa Institute of Research, Ltd. (DIR) focuses on economic forecast by using system. Fuji Research Institute, Corp. (FUJI RIC) focuses on survey and policy proposing in macro-economics, and analyzing technology. The Japan Research Institute, Ltd. (JRI) focuses on regional development, and R&D in advanced technology.

  9. [Changes in hemodynamics and oxygen metabolism of different Child-grade patients during orthotopic liver transplantation without veno-venous bypass].

    PubMed

    Zhao, Dong; Wang, Tian-long; Pan, Fang; Zhao, Lei; Zhang, Lian-feng; Yang, Ba-xian

    2006-08-18

    To investigate the changes in hemodynamics and oxygen metabolism of different Child-grade patients during orthotopic liver transplantation (OLT) without veno-venous bypass. Forty patients with end-stage liver disease undergoing non veno-venous OLT under general anesthesia were enrolled in this research. Swan-Ganz catheter was placed in the pulmonary artery via right internal jugular vein and right radial artery was cannulated to monitor mean pulmonary artery pressure (mPAP) and artery blood pressure (ABP) continuously. Pulmonary capillary wedge pressure (PCWP) and central venous pressure (CVP) were also recorded. Cardiac output (CO) was recorded at several time points, such as, 30 min after induction (T1), when inferior vena cava and portal vein were clamped (T2), 30 min after portal vein was clamped (T3), 10 min after unclamping of portal vein (T4), 60 min after graft reperfusion (T5) and at the end of the operation (T6). Blood samples were taken from radial and pulmonary artery for blood gas analysis and hemodynamic parameters, such as, cardiac index (CI), stroke volume index (SVI), pulmonary vascular resistance index (PVRI), and system vascular resistance index (SVRI); oxygen delivery (DO2) and oxygen consumption (VO2) were also calculated at these time points. (1) The mPAP values were much higher in group C than in group A or B at all time points. CVP was significantly increased at T1 or T2 in group C as compared with those points of Child's B or C. PCWP was increased significantly after unclamping of portal vein in all three groups and was much higher at several points in Child's C than in Child's A or B. The SVRI value of T1 and the PVRI value of T3 were much lower in group C than those points in group A and the value of SVRI/PVRI was less than normal except at T3 point. And blood gas analysis elucidated that PaO2 was higher than 400 mm Hg at any points. (2) Oxygen consumption was significantly decreased during the operation due to less blood supply and was

  10. Living donor liver transplantation for congenital absence of the portal vein.

    PubMed

    Sanada, Y; Mizuta, K; Kawano, Y; Egami, S; Hayashida, M; Wakiya, T; Mori, M; Hishikawa, S; Morishima, K; Fujiwara, T; Sakuma, Y; Hyodo, M; Yasuda, Y; Kobayashi, E; Kawarasaki, H

    2009-12-01

    The congenital absence of the portal vein (CAPV) is a rare venous malformation in which mesenteric venous blood drains directly into the systemic circulation. Liver transplantation (OLT) may be indicated for patients with symptomatic CAPV refractory to medical treatment, especially due to hyperammonemia, portosystemic encephalopathy, hepatopulmonary syndrome, or hepatic tumors. Because portal hypertension and collateral circulation do not occur with CAPV, significant splanchnic congestion may occur when the portocaval shunt is totally clamped during portal vein (PV) reconstruction in OLT. This phenomenon results in severe bowel edema and hemodynamic instability, which negatively impact the patient's condition and postoperative recovery. We have successfully reconstructed the PV in living donor liver transplantation (LDLT) using a venous interposition graft, which was anastomosed end-to-side to the portocaval shunt by a partial side-clamp, using a patent round ligament of the liver, which was anastomosed end-to-end to the graft PV with preservation of both the portal and caval blood flows. Owing to the differences in anatomy among patients, at LDLT for CAPV liver transplant surgeons should seek to preserve both portal and caval blood flows.

  11. Estimate carbon emissions from degraded permafrost with InSAR and a soil thermal model

    NASA Astrophysics Data System (ADS)

    Zhou, Z.; Liu, L.

    2016-12-01

    Climate warming, tundra fire over past decades has caused degradation in permafrost widely and quickly. Recent studies indicate that an increase in degradation could switch permafrost from a carbon sink to a source, with the potential of creating a positive feedback to anthropogenic climate warming. Unfortunately, Soil Organic Carbon (SOC) emissions from degraded permafrost unquantified, and limit our ability to understand SOC losses in arctic environments. This work will investigate recent 10 years of data already collected at the Anaktuvuk River fire (both ground and remote sensed), and will employ a soil thermal model to estimate SOC emission in this region. The model converts the increases in Active Layer Thickness (ALT), as measured by InSAR, to changes in Organic Layer Thickness (OLT), and SOC. ALOS-1/2 L-band SAR dataset will be used to produce the ATL changes over the study area. Soil prosperities (e.g. temperature at different depth, bulk density) will be used in the soil thermal model to estimate OLT changes and SOC losses. Ground measurement will validate the InSAR results and the soil thermal model. A final estimation of SOC emission will be produced in Anaktuvuk River region.

  12. Integrated coding-aware intra-ONU scheduling for passive optical networks with inter-ONU traffic

    NASA Astrophysics Data System (ADS)

    Li, Yan; Dai, Shifang; Wu, Weiwei

    2016-12-01

    Recently, with the soaring of traffic among optical network units (ONUs), network coding (NC) is becoming an appealing technique for improving the performance of passive optical networks (PONs) with such inter-ONU traffic. However, in the existed NC-based PONs, NC can only be implemented by buffering inter-ONU traffic at the optical line terminal (OLT) to wait for the establishment of coding condition, such passive uncertain waiting severely limits the effect of NC technique. In this paper, we will study integrated coding-aware intra-ONU scheduling in which the scheduling of inter-ONU traffic within each ONU will be undertaken by the OLT to actively facilitate the forming of coding inter-ONU traffic based on the global inter-ONU traffic distribution, and then the performance of PONs with inter-ONU traffic can be significantly improved. We firstly design two report message patterns and an inter-ONU traffic transmission framework as the basis for the integrated coding-aware intra-ONU scheduling. Three specific scheduling strategies are then proposed for adapting diverse global inter-ONU traffic distributions. The effectiveness of the work is finally evaluated by both theoretical analysis and simulations.

  13. Environmental Impact Research Program. Osprey Nest Platforms. Section 5.1.6, US Army Corps of Engineers Wildlife Resources Management Manual.

    DTIC Science & Technology

    1986-07-01

    34"x 0treated pole, with 101, olts5" min. top diam. 518"x 7" hardwood dowel,6’O set 1- 112" deep, glued TOP VIEW I r 2’-,9 Some as dinam . of pole usedI I...added strength ; these are described in the section entitled Tripod Support. Pole supports. Two designs are suggested for attaching the solid base

  14. VizieR Online Data Catalog: TrES-2b multi-band transit observations (Mislis+, 2010)

    NASA Astrophysics Data System (ADS)

    Mislis, D.; Schroeter, S.; Schmitt, J. H. M. M.; Cordes, O.; Reif, K.

    2010-02-01

    The OLT data were taken on 11 April 2009 using a 3Kx3K CCD with a 1x1 FOV and an I-band filter as in our previous observing run (Paper I, Mislis & Schmitt, 2009, Cat. ). The Calar Alto data were taken on 28 May 2009 using BUSCA and the 2.2m telescope. (1 data file).

  15. VizieR Online Data Catalog: Transit timing variations on Qatar-1 (von Essen+, 2013)

    NASA Astrophysics Data System (ADS)

    von Essen, C.; Schroter, S.; Agol, E.; Schmitt, J. H. M. M.

    2013-06-01

    The OLT data were taken between March 2011 and October 2012 using an Apogee Alta U9000 CCD with a 9'x9' field of view. The PTST data were taken between May and August 2012 using a Santa Barbara CCD with a 30'x30' field of view in a 3x3 binning and a Baade R-band filter setup. (2 data files).

  16. Acute quadriplegic myopathy with myosin-deficient muscle fibres after liver transplantation: defining the clinical picture and delimiting the risk factors.

    PubMed

    Miró, O; Salmerón, J M; Masanés, F; Alonso, J R; Graus, F; Mas, A; Grau, J M

    1999-04-27

    In the last few years, rare cases of acute quadriplegic myopathy (AQM*) with myosin-deficient muscle fibres occurring after solid organ transplantation has been reported. The aim of the present study was to review all cases of AQM with myosin deficient fibres seen at our institution among a large series of patients after orthotopic liver transplants (OLT), with special attention to clinical aspects and associated risk factors. Additionally, an extensive review of all ultrastructurally demonstrated cases of AQM in transplant recipients is also included. Among patients involved in 281 consecutive liver transplant procedures performed in a 4-year period, 3 men and 1 woman developed an arreflexic, flaccid quadriplegia in the immediate postoperative period of OLT. After ruling out other causes of weakness, a muscle biopsy was performed and a loss of thick (myosin) filaments was confirmed by ultrastructural analysis in all cases. Accurate clinical, epidemiological, and evolutive data were recorded. Corticosteroids had been used at usual dosage given to liver transplant recipients; all four patients had several intra- and postoperative complications leading to receiving significantly higher amounts of hemoderivates, to develop renal failure in all cases, and to require a significantly higher number of reoperations within a few days after transplantation than our contemporaneous global series of liver transplant recipients. AQM patients required a significantly longer intensive care unit and hospital stay. Muscular recovery was the rule, but currently a mild myopathic gait remains in three patients. These and other reported cases of AQM do not histologically and clinically differ from AQM seen in other critically ill patients who have not had transplants. Patients with a complicated intra- and postoperative course of OLT who develop newly acquired acute muscle weakness should be suspected as having acute AQM with myosin-deficient muscle fibres. In this setting

  17. Model for end-stage liver disease dynamic stratification of survival benefit.

    PubMed

    Avolio, A W; Siciliano, M; Barone, M; Lai, Q; Caracciolo, G L; Barbarino, R; Nicolotti, N; Lirosi, M C; Gasbarrini, A; Agnes, S

    2012-09-01

    Only patients with Model for End-stage Liver Disease (MELD) scores ≥18 or ≥17 experience a survival benefit (SB) at 12 and 36 months after liver transplantation (OLT). The SB calculation estimates the difference after stratification for risk categories between the survival rate of transplanted versus waiting list patients. The aim of this study was to perform a short- and long-term (60 months) SB analyses of a Italian OLT program. One-hundred seventy-one patients were stratified into four MELD classes (6-14, 15-18, 19-25, 26-40), and two groups: namely, waiting list (WL) and transplanted groups (TX). The median waiting time for transplanted patients was 4.4 months (range, 0-35). SB was expressed as mortality hazard ratio (MHR) as obtained through a Cox regression analysis using as a covariate the status of each patient in the waiting list (WL = 0, reference group) or the TX group (TX = 1). Values over 1 indicated the MHR in favor of the WL with the values below 1 indicating MHR in favor of Tx. In the MELD class 6 to 14, the MHR was above 1 at 3 and 6 months, indicating an SB in favor of WL; subsequently, the MHR dropped below 1, indicating an SB in favor of TX (P < .05). In the MELD class 15 to 18 the MHR was above 1 at 3 months, but below 1 subsequently (P < .05). For MELD classes 19 to 25 and 26 to 40, the MHR was always below 1 (P < .01). According to the SB approach, patients in the MELD class 6 to 14 could safely wait for at least 36 months; patients in the MELD class 15 to 18 should likely remain no longer than 12 months on the waiting list, and all the remaining patients with MELD > 18 should be transplanted as soon as possible. OLT should not be precluded but only postponed for MELD < 19 patients. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Safety and immunogenicity of a Vi polysaccharide-tetanus toxoid conjugate vaccine (Typbar-TCV) in healthy infants, children, and adults in typhoid endemic areas: a multicenter, 2-cohort, open-label, double-blind, randomized controlled phase 3 study.

    PubMed

    Mohan, Vadrevu Krishna; Varanasi, Vineeth; Singh, Anit; Pasetti, Marcela F; Levine, Myron M; Venkatesan, Ramasamy; Ella, Krishna M

    2015-08-01

    Enteric fever caused by Salmonella Typhi remains a major public health problem in developing countries. Typbar-TCV is a single-dose typhoid Vi polysaccharide-tetanus toxoid conjugate vaccine for persons ≥6 months of age. Six hundred fifty-four healthy subjects aged 2-45 years enrolled in a double-blind, randomized controlled trial (RCT) received a single dose of Typbar-TCV or comparator "Vi polysaccharide" (Typbar), and 327 healthy subjects aged 6-23 months received a single dose of Typbar-TCV in an open-label trial (OLT); both received single- or multidose presentations from different lots. After 2 years, subsets in each group received a booster dose. The primary objective included analysis of geometric mean titer (GMTs) and 4-fold rise of anti-Vi serum immunoglobulin G (IgG) enzyme-linked immunosorbent assay titers over baseline (seroconversion [SCN]) 42 days after immunization. Typbar-TCV recipients in the RCT attained higher anti-Vi IgG GMTs 42 days after immunization (SCN, 97%; GMT, 1293 [95% confidence interval {CI}, 1153-1449]) than recipients of Typbar (SCN, 93%; GMT, 411 [95% CI, 359-471]) (P < .001). Typbar-TCV was highly immunogenic in the OLT (SCN, 98%; GMT, 1937 [95% CI, 1785-2103]). Two years after vaccination, anti-Vi titers remained higher in Typbar-TCV subjects (GMT, 82 [95% CI, 73-92]); and exhibited higher avidity (geometric mean avidity index [GMAI], 60%) than in Typbar recipients (GMT, 46 [95% CI, 40-53]; GMAI 46%) in the RCT (P < .001). OLT Typbar-TCV recipients achieved GMT of 48 (95% CI, 42-55) and GMAI of 57%. Typbar-TCV induced multiple IgG subclasses and strong booster responses in all ages. No serious vaccine-attributable adverse events were observed. Single-dose Typbar-TCV is well tolerated and induces robust and long-lasting serum anti-Vi IgG across age groups. CTRI/2011/08/001957, CTRI/2014/01/004341. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved

  19. On-Line Point Positioning with Single Frame Camera Data

    DTIC Science & Technology

    1992-03-15

    tion algorithms and methods will be found in robotics and industrial quality control. 1. Project data The project has been defined as "On-line point...development and use of the OLT algorithms and meth- ods for applications in robotics , industrial quality control and autonomous vehicle naviga- tion...Of particular interest in robotics and autonomous vehicle navigation is, for example, the task of determining the position and orientation of a mobile

  20. Development of JSTAMP-Works/NV and HYSTAMP for Multipurpose Multistage Sheet Metal Forming Simulation

    NASA Astrophysics Data System (ADS)

    Umezu, Yasuyoshi; Watanabe, Yuko; Ma, Ninshu

    2005-08-01

    Since 1996, Japan Research Institute Limited (JRI) has been providing a sheet metal forming simulation system called JSTAMP-Works packaged the FEM solvers of LS-DYNA and JOH/NIKE, which might be the first multistage system at that time and has been enjoying good reputation among users in Japan. To match the recent needs, "faster, more accurate and easier", of process designers and CAE engineers, a new metal forming simulation system JSTAMP-Works/NV is developed. The JSTAMP-Works/NV packaged the automatic healing function of CAD and had much more new capabilities such as prediction of 3D trimming lines for flanging or hemming, remote control of solver execution for multi-stage forming processes and shape evaluation between FEM and CAD. On the other way, a multi-stage multi-purpose inverse FEM solver HYSTAMP is developed and will be soon put into market, which is approved to be very fast, quite accurate and robust. Lastly, authors will give some application examples of user defined ductile damage subroutine in LS-DYNA for the estimation of material failure and springback in metal forming simulation.

  1. Prevalence and awareness of halitosis in a sample of Jordanian population

    PubMed Central

    Hammad, Mohammad M.; Darwazeh, Azmi MG.; Al-Waeli, Haider; Tarakji, Bassel; Alhadithy, Teeb T.

    2014-01-01

    Objectives: This study was conducted to estimate the prevalence and awareness of halitosis among the subjects of a population, and also to compare the results of Halimeter® readings to self-estimation of halitosis and to assess the relationship between halitosis and oral health. Materials and Methods: A sample of 205 employees from the Jordan University for Science and Technology (JUST) were selected as study subjects. A standardized questionnaire focusing on dental hygiene, self-reported halitosis, and smoking was filled by all participants. In the clinical examination, the objective values for assessment of oral health and the presence of halitosis were gathered through an organoleptic test (OLT) and the measurement of volatile sulfur compound (VSC) level by Halimeter for each participant. Results: The prevalence of halitosis was 78%, with low rate of awareness (20.5%). The amount of TC played the most important role in increasing the concentration of VSCs in mouth air (P < 0.001). Conclusion: A statistically significant correlation was found between OLT and Halimeter values (P < 0.001). Subjective patients’ opinion did not correlate with the objective evaluation of halitosis. TC scores and smoking were the factors significantly associated to halitosis. The Halimeter showed promising characteristics regarding diagnosis of halitosis for clinical setting and field surveys. PMID:25625076

  2. Lack of Clinical Relevance of ANA and ASMA Positivity in Patients with Liver Transplantation without a History of Autoimmune Diseases.

    PubMed

    Pellegrini, Lucienne; Parrilli, Gianpaolo; Santonicola, Antonella; Cinquanta, Luigi; Caputo, Cesare; Ciacci, Carolina; Zingone, Fabiana

    2017-01-01

    The relevance of isolated autoimmunity elevation in orthotopic liver transplantation (OLT) patients is unknown. Our aim was to analyse how serum autoantibodies change in time and to evaluate their clinical relevance in OLT patients. Patients were invited to provide samples to evaluate ANA, AMA, ASMA, and LKM at the time of enrolment ( T 0), after 6 months ( T 6), and after 12 months ( T 12). We included 114 patients in the study (76% males, median age 62.5 years), finding isolated elevation of at least one serum antibody in up to 80% of them. We described fluctuating positive autoantibodies in the one year of observation, with only 45.6% of patients positive for ANA and less than 2% positive for ASMA, at all three times. Isolated elevation of tissue antibodies was not related to gender, age, HCC at transplant, early rejection, cause of transplantation, immunotherapy taken, and age at the time of the study. We did not detect a higher prevalence of positive autoimmunity in patients with signs of liver injury. ANA and ASMA evaluation in patients with liver transplantation and no history of autoimmune disease has no clinical relevance, since it varies in time and is not related to any risk factors or liver injury. Routine autoimmunity evaluation should be avoided.

  3. Lack of Clinical Relevance of ANA and ASMA Positivity in Patients with Liver Transplantation without a History of Autoimmune Diseases

    PubMed Central

    Pellegrini, Lucienne; Parrilli, Gianpaolo; Santonicola, Antonella; Cinquanta, Luigi; Caputo, Cesare

    2017-01-01

    The relevance of isolated autoimmunity elevation in orthotopic liver transplantation (OLT) patients is unknown. Our aim was to analyse how serum autoantibodies change in time and to evaluate their clinical relevance in OLT patients. Patients were invited to provide samples to evaluate ANA, AMA, ASMA, and LKM at the time of enrolment (T0), after 6 months (T6), and after 12 months (T12). We included 114 patients in the study (76% males, median age 62.5 years), finding isolated elevation of at least one serum antibody in up to 80% of them. We described fluctuating positive autoantibodies in the one year of observation, with only 45.6% of patients positive for ANA and less than 2% positive for ASMA, at all three times. Isolated elevation of tissue antibodies was not related to gender, age, HCC at transplant, early rejection, cause of transplantation, immunotherapy taken, and age at the time of the study. We did not detect a higher prevalence of positive autoimmunity in patients with signs of liver injury. ANA and ASMA evaluation in patients with liver transplantation and no history of autoimmune disease has no clinical relevance, since it varies in time and is not related to any risk factors or liver injury. Routine autoimmunity evaluation should be avoided. PMID:28337446

  4. Diverse effects of FK506 on the apoptosis of hepatocytes and infiltrating lymphocytes in an allografted rat liver.

    PubMed

    Moriuchi, Hiroki; Kamohara, Yukio; Eguchi, Susumu; Gu, Weili; Fujioka, Hikaru; Yamamoto, Takao; Tajima, Yoshitsugu; Kanematsu, Takashi; Koji, Takehiko

    2011-05-01

    The current study investigated whether FK506 (FK) regulates the apoptotic systems in allografted rat liver and the contribution of Fas/Fas-ligand system and Bcl-2 family during acute rejection. The recipients were divided into three groups, the allo, the allo-FK, and the syn group. Rats were euthanized 1, 3, 5, and 7 d after OLT. Apoptotic activity was explored using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay. The expression of Fas/Fas-ligand and Bcl-2/Bax in the grafted livers was investigated by Western blotting and immunohistochemistry. The apoptotic index (AI) of hepatocytes in the allo-FK group was less than that in the allo group. Fas in the allo group was more intense than that in the allo-FK group in the periportal areas on day 1 and 3, while Bcl-2 in the allo group was less intense than that in the allo-FK group in the pericaval areas at all time-points after OLT. FK provides beneficial antiapoptotic effects on hepatocytes in the grafted rat livers through both the down-regulation of Fas expression in the periportal areas and the up-regulation of Bcl-2 expression in the pericaval areas. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. Caffeine suppresses exercise-enhanced long-term and location memory in middle-aged rats: Involvement of hippocampal Akt and CREB signaling.

    PubMed

    Cechella, José L; Leite, Marlon R; da Rocha, Juliana T; Dobrachinski, Fernando; Gai, Bibiana M; Soares, Félix A A; Bresciani, Guilherme; Royes, Luiz F F; Zeni, Gilson

    2014-11-05

    The cognitive function decline is closely related with brain changes generated by age. The ability of caffeine and exercise to prevent memory impairment has been reported in animal models and humans. The purpose of the present study was to investigate whether swimming exercise and caffeine administration enhance memory in middle-aged Wistar rats. Male Wistar rats (18months) received caffeine at a dose of 30mg/kg, 5days per week by a period of 4weeks. Animals were subjected to swimming training with a workload (3% of body weight, 20min per day for 4weeks). After 4weeks, the object recognition test (ORT) and the object location test (OLT) were performed. The results of this study demonstrated that caffeine suppressed exercise-enhanced long-term (ORT) and spatial (OLT) memory in middle-aged and this effect may be related to a decrease in hippocampal p-CREB signaling. This study also provided evidence that the effects of this protocol on memory were not accompanied by alterations in the levels of activated Akt. The [(3)H] glutamate uptake was reduced in hippocampus of rats administered with caffeine and submitted to swimming protocol. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  6. A Novel Reliable WDM-PON System

    NASA Astrophysics Data System (ADS)

    Chen, Benyang; Gan, Chaoqin; Qi, Yongqian; Xia, Lei

    2011-12-01

    In this paper, a reliable Wavelength-Division-Multiplexing Passive Optical Network (WDM-PON) system is proposed. It can provide the protection against both the feeder fiber failure and the distribution fiber failure. When the fiber failure occurs, the corresponding switches in the OLT and in the ONU can switch to the protection link without affecting the users in normal status. That is to say, the protection for one ONU is independent of the other ONUs.

  7. Photonic integrated transmitter and receiver for NG-PON2

    NASA Astrophysics Data System (ADS)

    Tavares, Ana; Lopes, Ana; Rodrigues, Cláudio; Mãocheia, Paulo; Mendes, Tiago; Brandão, Simão.; Rodrigues, Francisco; Ferreira, Ricardo; Teixeira, António

    2014-08-01

    In this paper the authors present a monolithic Photonic Integrated Circuit which includes a transmitter and a receiver for NG-PON2. With this layout it is possible to build an OLT and, by redesigning some filters, also an ONU. This technology allows reducing the losses in the transmitter and in the receiver, increasing power budget, and also reducing the OEO conversions, which has been a major problem that operators want to surpass.

  8. Serial volumetric assessment of large for size liver grafts after whole cadaveric liver transplant in adults: do large liver grafts shrink in size?

    PubMed

    Bekheit, Mohamed; Rajakannu, Muthukumarassamy; Bucur, Petru; Adam, Rene; SaCunha, Antonio; Castaing, Denis; Cherqui, Daniel; Vibert, Eric

    2016-02-01

    After whole graft orthotopic liver transplantation (OLT), adaptation of the large grafts' volume to recipient weight is widely accepted despite the paucity of evidence on this subject. Thirty nine patients with GRWR > 2.5% were included in this study and subsequently divided into two groups with 3 ≥ GRWR > 3%. Patients had CT scans at three predetermined time points after OLT used for measuring the liver volume. The objective of this study is to evaluate the volumetric changes of whole large liver grafts after adult OLT. At LT, the mean graft recipient body weight ratio (GRWR) was 3.1 ± 0.4%. The mean liver weight was 1881 ± 68 g at LT, 2014 ± 99 ml at one week, 1725 ± 126 ml at 3 months, and 1632 ± 117 (ml) at >6 months. There is an initial increase at 1 week after LT and a subsequent decrease of liver volume on later measurements. None of the late volume measurements were significantly different from the initial graft volume at liver transplant in pair wise comparisons ANOVA repeated measures (p > 0.05). Similarly, the mean GRWR did not change significantly between the initial calculation at transplantation date and the subsequent measurements during the different study time points (F = 0.04, p = 0.96) with a mean of 3.1% (95% CI = 2.2-4.2). AUC ROC discriminated a cutoff of 3% for the initial GRWR above which grafts tend to decrease in size over time (c statistics = 0.74, p = 0.036). In a Clustered ANOVA repeated measures, there was no significant difference in the changes of liver volume between both groups. However, patients with GRWR > 3 showed a trend towards a latent reduction in volume over the tracing period. There was a tendency, but none significant; towards a higher bilirubin, AST, ALT levels over the first postoperative days in recipients with GRWR > 3. Large grafts do not significantly decrease in size. Nonetheless, grafts weighing >3% of the GRWR show a different trend towards decrease in size over time. Copyright © 2015. Published by

  9. Proceedings of the Meeting of the Coordinating Group on Modern Control Theory (4th) Held at Rochester, Michigan, on 27-28 October 1982. Part II,

    DTIC Science & Technology

    1983-01-01

    DCUMNTATON AGEREAD INSTRUCTIONS ______ REPORT___DOCUMENTATION _____PAGE_ BEFORE COMPLETKNG FORM 1REPORT NUMBER ILGOVT ACCESSION No. 3 . RECIPIENT’S...Herbert E. Cohen) control 0900 - Endgame Performance Study of a Special Class of Interceptors by Dr. Jonathan Korn ALPHATECH, Inc. 3 New England Executive...tactile/force feedback sensor applications. 3 L i7 TYPICAL GRIPPER FACE (NOT IN GRIPPER B3OLTS 00 BASE SLIP Nm mSENSORS "o 0 TORQUE, GRIP 0 fie d e

  10. Installation Restoration Program. Phase II. Confirmation/Quantification. Stage 1 for Tinker AFB, Oklahoma. Volume 2. Appendices,

    DTIC Science & Technology

    1985-09-01

    Special Olt 9-; ~ ~ ~ ~ ~ J -..-- w--- ’- V - V --y a - . . . . . . RADIAN APPENDIX A Definitions, Nomenclatures and Units A- i . -- 5. . -, - - STAGED...contaminatg ed 11 a thei±r~ iMei S-t.r-roundlin. Review the u f -r Ai Force investigationa. These *r-esu I.ts shall~ I & prvie une eatcvr B-5 -9 V q M I ...results or highly complicated nonlinear mathematical modeling , should * be precise, clear and technically defendable. This section should clearly

  11. Recent Selected Papers of Northwestern Polytechnical University in Two Parts. Part I. 1979.

    DTIC Science & Technology

    1981-08-20

    pressure coefficient is calculated by the exact Bernoulli equation. Two numerical examples are included, and the results agree fairly well with known... Bernoulli equation is applied to cal- culate the pressure coefficient: ft. 2 2, Lq32) In the above expression, all the derivatives are calculated by...0.14: R Olt(6) The real part on the unit circle in ecuation (2) is used. Making use of equations (5) and (6), both sides of equation (2) are expanded

  12. The Development of Decision Aids for Counter-Terrorist Applications

    DTIC Science & Technology

    1980-12-01

    I.D. AM OLT of PLO A14YOLP of PLO Agua Sandinist TPLF of Turkey 0 TERORISTS 3 4 25 2 GROUP CAPABILITY Unknown Unknown Auto Weapons Sten Gun "DEADLINE...of any terrorist group to different situ - ations are not independent, but reflect a coherent policy regarding violence and willingness to negotiate...importance in this stage is the need to deter future terrorist activities with- out jeopardizing our credibility in future negotiation situ - ations. I8

  13. Research and emulation of ranging in BPON system

    NASA Astrophysics Data System (ADS)

    Yang, Guangxiang; Tao, Dexin; He, Yan

    2005-12-01

    Ranging is one of the key technologies in Broadband Passive Optical Network based on the ATM (BPON) system. It is complex for software designers and difficult to test. In order to simplify the ranging procedure, enhance its efficiency, and find an appropriate method to verify it, a new ranging procedure that completely satisfies the requirements specified in ITU-T G.983.1 and one verifying method is proposed in this paper. A kind of ranging procedure without serial number (SN) searching function, called one-by-one ranging are developed under the condition of cold PON, cold Optical Network Termination (ONU). The ranging procedure includes the use of OLT and ONU flow charts respectively. By using the network emulation software OPNET, the BPON system is modeled and the ranging procedure is simulated. The emulation experimental results show that the presented ranging procedure can effectively eliminate the collision of burst mode signals between ONUs, which can be ranged one-by-one under the controlling of OLT, while also enhancing the ranging efficiency. As all of the message formats used in this research conform with the ITU-T G.983.1, the ranging procedure can meet the protocol specifications with good interoperability, and is very compatible with products of other manufacturer. According to the present study of ranging procedures, guidelines and principles are provided, Also some design difficulties are eliminated in the software design.

  14. Pulsed laser-based optical frequency comb generator for high capacity wavelength division multiplexed passive optical network supporting 1.2 Tbps

    NASA Astrophysics Data System (ADS)

    Ullah, Rahat; Liu, Bo; Zhang, Qi; Saad Khan, Muhammad; Ahmad, Ibrar; Ali, Amjad; Khan, Razaullah; Tian, Qinghua; Yan, Cheng; Xin, Xiangjun

    2016-09-01

    An architecture for flattened and broad spectrum multicarriers is presented by generating 60 comb lines from pulsed laser driven by user-defined bit stream in cascade with three modulators. The proposed scheme is a cost-effective architecture for optical line terminal (OLT) in wavelength division multiplexed passive optical network (WDM-PON) system. The optical frequency comb generator consists of a pulsed laser in cascade with a phase modulator and two Mach-Zehnder modulators driven by an RF source incorporating no phase shifter, filter, or electrical amplifier. Optical frequency comb generation is deployed in the simulation environment at OLT in WDM-PON system supports 1.2-Tbps data rate. With 10-GHz frequency spacing, each frequency tone carries data signal of 20 Gbps-based differential quadrature phase shift keying (DQPSK) in downlink transmission. We adopt DQPSK-based modulation technique in the downlink transmission because it supports 2 bits per symbol, which increases the data rate in WDM-PON system. Furthermore, DQPSK format is tolerant to different types of dispersions and has a high spectral efficiency with less complex configurations. Part of the downlink power is utilized in the uplink transmission; the uplink transmission is based on intensity modulated on-off keying. Minimum power penalties have been observed with excellent eye diagrams and other transmission performances at specified bit error rates.

  15. Impact of backreflections on single-fiber bidirectional wavelength-division-multiplexing passive optical networks (WDM-PONs)

    NASA Astrophysics Data System (ADS)

    Gao, Shiyu

    With increased demand for bandwidth-hungry applications such as video-on-demand, wavelength-division-multiplexing passive optical network (WDM-PON) has become a strong contender in overcoming the last mile bottle neck. However, the wide-scale deployment of WDM-PONs has been delayed mainly due to the high cost of wavelength-specific optical components. To realize cost-effective WDM-PONs, various wavelength-independent, so called colorless architectures, have been developed so that all the subscribers can have identical optical network units (ONUs). In such WDM-PONs, however, single-fiber bidirectional transmission results in degradation of system performance caused by interference between the signals and backreflections. This thesis investigates the impact of backreflections on single-fiber bidirectional WDM-PONs. A WDM-PON with various optical line terminals (OLTs) and colorless ONU configurations is presented. The dependence of the power penalty, caused by backreflections, on a variety of parameters is investigated. This includes parameters such as the source linewidths, receiver bandwidth, transmission line loss (TLL), ONU gain, chirp effect at the ONU and optical return loss (ORL), in various WDM-PON configurations. The WDM-PON with continuous wave (CW) seed light and remodulation schemes are both presented and studied experimentally. The impacts of the backreflections on the single-fiber bidirectional WDM-PON with various OLT and ONU configurations are compared and analyzed accordingly.

  16. Protein C activity and postoperative metabolic liver function after liver transplantation.

    PubMed

    Wagener, G; Diaz, G; Guarrera, J V; Minhaz, M; Renz, J F; Sladen, R N

    2012-06-01

    Protein C is a natural thrombin antagonist produced by hepatocytes. Its levels are low in liver failure and predispose patients to increased risk for thrombosis. Little is known about the relationship between protein C activity and hepatic function after orthotopic liver transplantation (OLT). We measured protein C activity of 41 patients undergoing liver transplantation by the Staclot method (normal range, 70%-130%) preoperatively and then daily on postoperative days (POD) 0-5. The mean protein C activity was low before OLT (34.3 ± 4.3%) and inversely correlated with the preoperative Model for End-Stage Liver Disease score (Spearman's r = -0.643; P < .0001). Mean activity increased significantly on POD 1 (58.9 ± 4.5%), and remained above preoperative levels through POD 5. Ten patients developed metabolic liver dysfunction defined by a serum total bilirubin >5 mg/dL on POD 7. These patients had significantly lower protein C activity from POD 3 (47.2 ± 9.6% vs 75.9 ± 5.8%; P = .01) to POD 5. Preoperative protein C activity correlated inversely with the severity of liver failure as indicated by preoperative MELD score. Protein C activity recovered rapidly in patients with good allograft function but remained significantly lower in patients who had limited metabolic function as evidenced by increased total bilirubin levels. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. GSK3β and VDAC Involvement in ER Stress and Apoptosis Modulation during Orthotopic Liver Transplantation

    PubMed Central

    Zaouali, Mohamed Amine; Panisello, Arnau; Lopez, Alexandre; Castro, Carlos; Folch, Emma; Carbonell, Teresa; Rolo, Anabela; Palmeira, Carlos Marques; Garcia-Gil, Agustin; Adam, René; Roselló-Catafau, Joan

    2017-01-01

    We investigated the involvement of glycogen synthase kinase-3β (GSK3β) and the voltage-dependent anion channel (VDAC) in livers subjected to cold ischemia–reperfusion injury (I/R) associated with orthotopic liver transplantation (OLT). Rat livers were preserved in University of Wisconsin (UW) and Institute Georges Lopez (IGL-1) solution, the latter enriched or not with trimetazidine, and then subjected to OLT. Transaminase (ALT) and HMGB1 protein levels, glutamate dehydrogenase (GLDH), and oxidative stress (MDA) were measured. The AKT protein kinase and its direct substrates, GSK3β and VDAC, as well as caspases 3, 9, and cytochrome C and reticulum endoplasmic stress-related proteins (GRP78, pPERK, ATF4, and CHOP), were determined by Western blot. IGL-1+TMZ significantly reduced liver injury. We also observed a significant phosphorylation of AKT, which in turn induced the phosphorylation and inhibition of GSK3β. In addition, TMZ protected the mitochondria since, in comparison with IGL-1 alone, we found reductions in VDAC phosphorylation, apoptosis, and GLDH release. All these results were correlated with decreased ER stress. Addition of TMZ to IGL-1 solution increased the tolerance of the liver graft to I/R injury through inhibition of GSK3β and VDAC, contributing to ER stress reduction and cell death prevention. PMID:28282906

  18. A Descriptive Study of the DoD-Managed Freight Forwarder Concept.

    DTIC Science & Technology

    1986-09-01

    AFLC/PMPO AMSAC-OL/ 7 AFLC ILC/ AWST MTMCEA/ ITEL AFLC ILC/EC MTMC-ITX AFLC ILC/GB USN/OP-632B AF IT! LSM USN/SUP-07C DISAM/DIC USASAC-NCAD (OL/T) SAAC...commercial insurance coverage for the protection of all purchaser-owned FMS materiel while in custody of the freight forwarder. r . Process FMS customer...export for each shipment. r . Provide export boxing and marking if required. s. Carry out freight rate negotiations as required. t. Retrieve freight from

  19. Long reach DWDM-PON with 12.5 GHz channel spacing based on comb source seeding

    NASA Astrophysics Data System (ADS)

    Zhou, Zhao; Nie, Hai-tao; Wang, Yao-jun

    2016-07-01

    A long reach dense wavelength division multiplexing passive optical network (DWDM-PON) with 12.5 GHz channel spacing is proposed and experimentally demonstrated. An optical frequency comb source is used to provide the multiwavelength seeding light, while reflective semiconductor optical amplifiers (RSOAs) are installed in both optical line terminal (OLT) and optical network units (ONUs) as colorless transmitter. The experimental results show that the bidirectional transmission for 1.2 Gbit/s data rate is achieved over 80 km single mode fiber (SMF).

  20. Study of dual-polarization OQAM-OFDM PON with direct detection

    NASA Astrophysics Data System (ADS)

    Luo, Qing-long; Feng, Min; Bai, Cheng-lin; Hu, Wei-sheng

    2016-01-01

    An offset quadrature amplitude modulation orthogonal frequency-division multiplexing (OQAM-OFDM) passive optical network (PON) architecture with direct detection is brought up to increase the transmission range and improve the system performance. In optical line terminal (OLT), OQAM-OFDM signals at 40 Gbit/s are transmitted as downstream. At each optical network unit (ONU), the optical OQAM-OFDM signal is demodulated with direct detection. The results show that the transmission distance can exceed 20 km with negligible penalty under the experimental conditions.

  1. Shock Tunnel Tests of Arched Wall Panels

    DTIC Science & Technology

    1974-07-01

    NCNOR « LOT S/W ETC lOLT ANCMO« NOO IEE DETAIL* / tELOW , , METAL TIE* / I*" 0. C. VERT -HAiONRT «ALL...same as shown in Table 2-1. 2-6 m^ Table 2-1 SPACING OF WALL TIES i Moiimuffl Dittonc« Moiimum Spocing ef No 4 Gogt Wall Typ. I K«twHn Lot ...sides free to move), the flexural cracking occurs at the top, botton \\ and center, and the resistance to motion, induced by ’ wedging"or geometric

  2. A novel WDM passive optical network architecture supporting two independent multicast data streams

    NASA Astrophysics Data System (ADS)

    Qiu, Yang; Chan, Chun-Kit

    2012-01-01

    We propose a novel scheme to perform optical multicast overlay of two independent multicast data streams on a wavelength-division-multiplexed (WDM) passive optical network. By controlling a sinusoidal clock signal and shifting the wavelength at the optical line terminal (OLT), the delivery of the two multicast data, being carried by the generated optical tones, can be independently and flexibly controlled. Simultaneous transmission of 10-Gb/s unicast downstream and upstream data as well as two independent 10-Gb/s multicast data was successfully demonstrated.

  3. PowerFilm PowerShade Fixed Site Solar System Cost Reduction Plan

    DTIC Science & Technology

    2014-07-31

    2337 230’^ St Ames, lA 50014 JL’Olt^lO:pi𔄁oq7 j pageii Executive summary Power film and its partners have developed a Generation II PowerShade...which meets or exceeds the goals of this development contract, increasing power and improving the ROI of the power shade significantly while improving a...number of the human factors. Comparing the Gen II 1.8 KW PowerShade to the equivalent power Gen I unit (Gen I Medium), The cost has been reduced

  4. Effects of Tadalafil Once-Daily or On-Demand vs Placebo on Return to Baseline Erectile Function After Bilateral Nerve-Sparing Radical Prostatectomy--Results from a Randomized Controlled Trial (REACTT).

    PubMed

    Mulhall, John P; Brock, Gerald; Oelke, Matthias; Fode, Mikkel; Probst, Kai A; Henneges, Carsten; d'Anzeo, Gianluca; Rossi, Andrea; Büttner, Hartwig

    2016-04-01

    The multicenter, randomized, double-blind, double-dummy, placebo-controlled REACTT trial suggested that treatment with tadalafil once daily (OaD) started early after bilateral nerve-sparing radical prostatectomy (nsRP) for prostate cancer may contribute to erectile function (EF)-recovery, which was predefined as achieving an International Index of Erectile Function (IIEF)-EF score ≥22. Here, we report descriptive post-hoc analyses, using the more strict definition for EF-recovery of returning back to the pre-surgery IIEF-EF-level ("back-to-baseline analysis"). REACTT included 422 men <68 years with adenocarcinoma of the prostate and preoperative IIEF-EF ≥22 who underwent nsRP at 50 centers from 9 European countries and Canada. Patients were randomized post-nsRP 1:1:1 to 9-month double-blind treatment (DBT) with tadalafil 5 mg OaD (n = 139), tadalafil 20 mg on-demand (pro-re-nata, PRN; n = 142), or placebo (n = 141), followed by 6-week drug-free washout (DFW) and 3-month open-label tadalafil OaD treatment (OLT). Proportion of patients returning to their preoperative IIEF-EF category (22-25 or ≥26) at the end of DBT, DFW, and OLT. Overall, 92.4% of patients had pre-surgery (baseline) IIEF-EF scores ≥26 (tadalafil OaD 94.2%, PRN 91.6%, placebo 91.5%), 7.4% had IIEF-EF 22-25. At the end of DBT, 22.3% of patients on tadalafil OaD had achieved "back-to-baseline" IIEF-EF, compared with 11.3% on tadalafil PRN and 7.8% on placebo. Of all 58 patients "back-to-baseline" at the end of DBT, only 1 PRN-group patient had started from a baseline IIEF-EF <26. The treatment-group difference at the end of DBT was not maintained after DFW. After 3 months of OLT with tadalafil OaD, the proportion of patients with "back-to-baseline" IIEF-EF had almost doubled in all 3 groups. Changing the definition for EF-recovery from IIEF-EF ≥22 to the more strict definition of "returning back-to-baseline IIEF-EF" had no major impact. Tadalafil OaD started early after nsRP improved

  5. Optimization of immunosuppressive therapy based on a multiparametric mixed lymphocyte reaction assay reduces infectious complications and mortality in living donor liver transplant recipients.

    PubMed

    Tanaka, Y; Tashiro, H; Onoe, T; Ide, K; Ishiyama, K; Ohdan, H

    2012-03-01

    We investigated the clinical relevance of immune monitoring by a multiparametric mixed lymphocyte reaction (MLR) assay, wherein the number and phenotype of alloreactive precursors can be quantified by combining the results of carboxyfluorescein diacetate succinimidyl ester labeling and flow cytometry analysis. In 51 adult patients undergoing living donor liver transplantation (OLT), immunosuppressive drugs were dosed on the basis of immune monitoring by the MLR assay (optimized protocol: group O). In 64 other patients, the agents were prescribed according to empirical regimens (empirical protocol: group E). In group O, MLR assays were performed at 2- to 4-week intervals until 3 months after OLT and thereafter at 3- to 6-month intervals. Therapeutic adjustments for immunosuppressants were determined by tapering the doses in cases of anti-donor hyporesponsiveness for both CD4+ and CD8+ T-cell subsets. The 1-year patient and graft survivals in groups O versus E were 90.2% versus 76.6%, respectively. The incidence of acute rejection episodes (ARE) among group O (13.7%) were lower than in cohort E (28.1%). None of the patients in group O while four patients (3%) in group E already have shown chronic rejection to date. The incidences of bacteremia and fungal infections in group O (9.8% and 7.5%, respectively) were lower than in cohort E (18.8% and 12.6%, respectively). A multiparametric MLR assay may facilitate the development of adequate immunosuppressive regimens. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. A novel design of optical CDMA system based on TCM and FFH

    NASA Astrophysics Data System (ADS)

    Fang, Jun-Bin; Xu, Zhi-Hai; Huang, Hong-bin; Zheng, Liming; Chen, Shun-er; Liu, Wei-ping

    2005-02-01

    For the application in Passive Optical Network (PON), a novel design of OCDMA system scheme is proposed in this paper. There are two key components included in this scheme: a new kind of OCDMA encoder/decoder system based on TCM and FFH and an improved Optical Line Terminal (OLT) receiving system with improved anti-interference performance by the use of Long Period Fiber Grating (LPFG). In the encoder/decoder system, Trellis Coded Modulation (TCM) encoder is applied in front of the FFH modulator. Original signal firstly is encoded through TCM encoder, and then the redundant code out of the TCM encoder will be mapped into one of the FFH modulation signal subsets for transmission. On the receiver (decoder) side, transmitting signal is demodulated through FFH and decoded by trellis decoder. Owing to the fact that high coding gain can be acquired by TCM without adding transmitting band and reducing transmitting speed, TCM is utilized to ameliorate bit error performance and reduce multi-user interference. In the OLT receiving system, EDFA and LPFG are placed in front of decoder to get excellent gain flatness on a large bandwidth, and Optical Hard Limiter (OHL) is also deployed to improve detection performance, through which the anti-interference performance of receiving system can be greatly enhanced. At the same time, some software is used to simulate the system performance for further analysis and authentication. The related work in this paper provides a valuable reference to the research.

  7. Angiogenesis and proliferation of bile duct enhances ischemic tolerance in rats with cirrhosis

    PubMed Central

    Zhang, Zhiqiang; Li, Zhennan; Zou, Chen; Zhang, Jingjing; Zhu, Yi; Miao, Yi

    2015-01-01

    Background/aims: Primary biliary cirrhosis (PBC), an autoimmune disease of the liver, is marked by slow progressive destruction of bile ducts. These patients with PBC often undergo orthotopic liver transplantation (OLT). Ischemic bile duct lesion (IBDL) is a major source of morbidity and even mortality after OLT. Cirrhosis of the liver has a higher tolerance to ischemia than a normal liver, but the mechanism remains unknown. Angiogenesis and proliferation of bile duct often responses in bile duct ischemia, which may enhance ischemic tolerance in patients with cirrhosis. Methodology: To test the hypothesis, a rat model with cirrhosis was established. Biochemical indexes of ischemic severity were measured including total bilirubin (TBIL) and direct bilirubin (DBIL). Immunohistochemical assay was performed for Ki67 (a biomarker for the proliferation of bile duct) and CD34 (a biomarker of angiogenesis). Results: The levels were lower for TBIL and DBIL in the bile duct from rat model with cirrhosis than that from a normal rat after ischemic surgery (P < 0.05). The levels were higher for Ki67 and CD34 from a rat model with cirrhosis than that from a normal rat after ischemic surgery (P < 0.05). Conclusions: The results suggest that a liver with cirrhosis has a better ischemic tolerance than a normal liver. Angiogenesis and proliferation of bile duct enhances ischemic tolerance in rats with cirrhosis. More research on the pathogenesis of IBDLs is needed for developing more specific preventive or therapeutic strategies. PMID:26550120

  8. Self-healing ring-based WDM-PON

    NASA Astrophysics Data System (ADS)

    Zhou, Yang; Gan, Chaoqin; Zhu, Long

    2010-05-01

    In this paper, a survivable ring-based wavelength-division-multiplexing (WDM)-passive optical network (PON) for fiber protection is proposed. Protections for feeder fiber and distributed fiber are independent in the scheme. Optical line terminal (OLT) and optical network units (ONUs) can automatically switch to protection link when fiber failure occurs. Protection distributed fiber is not required in the scheme. Cost-effective components are used in ONUs to minimize costs of network. A simulation study is performed to demonstrate the scheme. Its result shows good performance of upstream and downstream signals.

  9. Effects of curcumin on short-term spatial and recognition memory, adult neurogenesis and neuroinflammation in a streptozotocin-induced rat model of dementia of Alzheimer's type.

    PubMed

    Bassani, Taysa B; Turnes, Joelle M; Moura, Eric L R; Bonato, Jéssica M; Cóppola-Segovia, Valentín; Zanata, Silvio M; Oliveira, Rúbia M M W; Vital, Maria A B F

    2017-09-29

    Curcumin is a natural polyphenol with evidence of antioxidant, anti-inflammatory and neuroprotective properties. Recent evidence also suggests that curcumin increases cognitive performance in animal models of dementia, and this effect would be related to its capacity to enhance adult neurogenesis. The aim of this study was to test the hypothesis that curcumin treatment would be able to preserve cognition by increasing neurogenesis and decreasing neuroinflammation in the model of dementia of Alzheimer's type induced by an intracerebroventricular injection of streptozotocin (ICV-STZ) in Wistar rats. The animals were injected with ICV-STZ or vehicle and curcumin treatments (25, 50 and 100mg/kg, gavage) were performed for 30days. Four weeks after surgery, STZ-lesioned animals exhibited impairments in short-term spatial memory (Object Location Test (OLT) and Y maze) and short-term recognition memory (Object Recognition Test - ORT), decreased cell proliferation and immature neurons (Ki-67- and doublecortin-positive cells, respectively) in the subventricular zone (SVZ) and dentate gyrus (DG) of hippocampus, and increased immunoreactivity for the glial markers GFAP and Iba-1 (neuroinflammation). Curcumin treatment in the doses of 50 and 100mg/kg prevented the deficits in recognition memory in the ORT, but not in spatial memory in the OLT and Y maze. Curcumin treatment exerted only slight improvements in neuroinflammation, resulting in no improvements in hippocampal and subventricular neurogenesis. These results suggest a positive effect of curcumin in object recognition memory which was not related to hippocampal neurogenesis. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Classical Notions of Coagulation Revisited in Relation with Blood Losses, Transfusion Rate for 700 Consecutive Liver Transplantations.

    PubMed

    Massicotte, Luc; Thibeault, Lynda; Roy, André

    2015-07-01

    During the last decade, improved surgical and anesthetic management, such as better understanding of coagulation defects and the use of the phlebotomy, has reduced intraoperative blood product transfusions during orthotopic liver transplantation (OLT). The goal of this study was to look at the impact of initial conventional coagulation tests on blood loss and blood product requirement and to evaluate the role of the phlebotomy during liver transplantations. A total of 700 consecutive OLTs were studied. The group of patients was split into two according to the median of starting international normalized ratio to study blood losses and transfusion rate. Logistic regression was used to determine the main predictors of blood loss, intraoperative blood transfusion, and survival. There was no intergroup difference for demographic characteristics. The mean blood loss was 1,184 mL with a median of 920 mL. Overall, 77.4% of the patients did not receive any blood product and the mean transfusion rate of red blood cells (RBCs) was 0.5 ± 1.4 units per patient. Severity of recipients' disease did not correlate with blood loss or transfusion rate. Starting hemoglobin value was the only biochemical variable linked to RBC transfusions. Phlebotomy was linked to decrease in blood loss, RBC transfusions, and increased survival rate. It is concluded that bleeding did not correlate with traditional coagulation defects or the severity of recipient's disease. Preemptive phlebotomy was linked to a decreased blood loss, a decreased transfusion rate, and an increased 1-year survival rate. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  11. Liver transplantation from anti-hepatitis C virus-positive donors: our experience.

    PubMed

    Álvaro, E; Abradelo, M; Fuertes, A; Manrique, A; Colina, F; Alegre, C; Calvo, J; García, M; García-Sesma, A; Cambra, F; Sanabria, R; Moreno, E; Jimenez, C

    2012-01-01

    Hepatitis C (HCV) is among the most common causes of end-stage liver disease worldwide. The donor shortage leads us to consider alternative organ sources such as HCV-positive donors. The outcomes of these transplants must be evaluated thoroughly since there is universal recurrence of disease among HCV-positive liver transplant recipients. From January 2005 to April 2011, we performed 143 liver transplants (OLT) to treat end-stage liver disease secondary to HCV infection. Thirteen patients (9,1%) received livers from HCV-positive donors. A control group consisted of 130 HCV-positive patients who underwent OLT during the same period with organs from HCV-negative donors. Donor HCV status was assessed by 2 tests: HCV antibodies and viral load. Not only recipient and graft survivals were analyzed, but also frequency, timing and severity of hepatitis recurrence. Among 143 transplants performed in HCV-positive recipients during a 6-year period from January 1, 2005, to April 30, 2011, 9.1% of patients received an organ from an anti-HCV-positive donor, 72.7% of whom showed a negative viral load. The vast majority (80%) of our patients suffered hepatitis during their follow-up, 22.4% of which were severe cases. No significant difference in patient or graft survival was observed between the 2 groups. A high percentage of grafts with initial positive serology for HCV showed no viral replication. Grafts from HCV-positive donors can be considered to be a safe, effective source for liver donation. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Hepcidin expression does not rescue the iron-poor phenotype of Kupffer cells in Hfe-null mice after liver transplantation.

    PubMed

    Garuti, Cinzia; Tian, Yinghua; Montosi, Giuliana; Sabelli, Manuela; Corradini, Elena; Graf, Rolf; Ventura, Paolo; Vegetti, Alberto; Clavien, Pierre-Alain; Pietrangelo, Antonello

    2010-07-01

    Hemochromatosis is a common hereditary disease caused by mutations in HFE and characterized by increased absorption of iron in the intestine. However, the intestine does not appear to be the site of mutant HFE activity in the disease; we investigated the role of the liver-the source of the iron regulatory hormone hepcidin-in pathogenesis in mice. We exchanged livers between Hfe wild-type (+/+) and Hfe null (-/-) mice by orthotopic liver transplantation (OLT) and assessed histopathology, serum and tissue iron parameters, and hepatic hepcidin messenger RNA expression. At 6-8 months after OLT, Hfe(-/-) mice that received Hfe(-/-) livers maintained the hemochromatosis phenotype: iron accumulation in hepatocytes but not Kupffer cells (KC), increased transferrin levels, and low levels of iron in the spleen. Hfe(+/+) mice that received Hfe(-/-) livers had increased levels of iron in serum and liver and low levels of iron in spleen. However, they did not develop the iron-poor KCs that characterize hemochromatosis: KCs appeared iron rich, although hepatic hepcidin expression was low. Transplantation of Hfe(+/+) livers into Hfe(-/-) mice prevented hepatic iron accumulation but did not return spleen and plasma levels of iron to normal; KCs still appeared to be iron poor, despite normal hepcidin expression. In Hfe(-/-) mice, transplantation of livers from Hfe(+/+) mice reversed the iron-loading phenotype associated with hemochromatosis (regardless of Hfe expression in intestine). However, KCs still had low levels of iron that were not affected by hepatic hepcidin expression. These findings indicate an independent, iron-modifying effect of HFE in KCs. Copyright 2010 AGA Institute. Published by Elsevier Inc. All rights reserved.

  13. WDM/TDM PON experiments using the AWG free spectral range periodicity to transmit unicast and multicast data

    NASA Astrophysics Data System (ADS)

    Bock, Carlos; Prat, Josep

    2005-04-01

    A hybrid WDM/TDM PON architecture implemented by means of two cascaded Arrayed Waveguide Gratings (AWG) is presented. Using the Free Spectral Range (FSR) periodicity of AWGs we transmit unicast and multicast traffic on different wavelengths to each Optical Network Unit (ONU). The OLT is equipped with two laser stacks, a tunable one for unicast transmission and a fixed one for multicast transmission. We propose the ONU to be reflective in order to avoid any light source at the Costumer Premises Equipment (CPE). Optical transmission tests demonstrate correct transmission at 2.5 Gbps up to 30 km.

  14. Bidirectional and simultaneous FTTX/Ethernet services using RSOA based remodulation and polarization multiplexing technique

    NASA Astrophysics Data System (ADS)

    Das, Anindya S.; Patra, Ardhendu S.

    2015-08-01

    A bidirectional and simultaneous transmission of Ethernet, FTTX services through single optical carrier wavelength employing polarization multiplexing technique in the transmitter end and the user end. 10 Gbps and 2.5 Gbps datarates are transmitted over 50 km single mode fiber employing POLMUX technique at OLT and ONU to provide Ethernet and FTTX services concurrently to the user. Reflective semiconductor optical amplifier is used to reuse and remodulate the downlink signal to uplink transmission. The upstream and the downstream transmission performances are observed by the bit error rate values and the eye diagrams obtained by the BER analyzer.

  15. In-service communication channel sensing based on reflectometry for TWDM-PON systems

    NASA Astrophysics Data System (ADS)

    Iida, Daisuke; Kuwano, Shigeru; Terada, Jun

    2014-05-01

    Many base stations are accommodated in TWDM-PON based mobile backhaul and fronthaul networks for future radio access, and failed connections in an optical network unit (ONU) wavelength channel severely degrade system performance. A cost effective in-service ONU wavelength channel monitor is essential to ensure proper system operation without failed connections. To address this issue we propose a reflectometry-based remote sensing method that provides wavelength channel information with the optical line terminal (OLT)-ONU distance. The method realizes real-time monitoring of ONU wavelength channels without signal quality degradation. Experimental results show it achieves wavelength channel distinction with high distance resolution.

  16. A power-efficient switchable CML driver at 10 Gbps

    NASA Astrophysics Data System (ADS)

    Peipei, Chen; Lei, Li; Huihua, Liu

    2016-02-01

    High static power limits the application of conventional current-mode logic(CML). This paper presents a power-efficient switchable CML driver, which achieves a significant current saving by 75% compared with conventional ones. Implemented in the 130 nm CMOS technology process, the proposed CML driver just occupies an area about 0.003 mm2 and provides a robust differential signal of 1600 mV for 10 Gbps optical line terminal (OLT) with a total current of 10 mA. The peak-to-peak jitter is about 4 ps (0.04TUI) and the offset voltage is 347.2 mV @ 1600 mVPP.

  17. Multipurpose Arcade Combat Simulator (MACS) Basic Rifle Marksmanship (BRM) Program

    DTIC Science & Technology

    1989-10-01

    that shooters are aiming at the center of mass of each target to the best of their abilities. It then computes the central point of the three-round shot...group, measures the distance between this central point and the actual center of the target, and uses this distance as a constant offset value, which...WAE LIto, SIT 3 CLA HO CHANGE 151100 CM? $111 ,10-Im6%AAG ISE LEST30 IF$ SCREEN OCO ias NEXT 2 syltJ4 NSK L91T1)S Olt ?ILA ,r6 SORDERA COLo0 410 Ltx7 2

  18. Collaborative video caching scheme over OFDM-based long-reach passive optical networks

    NASA Astrophysics Data System (ADS)

    Li, Yan; Dai, Shifang; Chang, Xiangmao

    2018-07-01

    Long-reach passive optical networks (LR-PONs) are now considered as a desirable access solution for cost-efficiently delivering broadband services by integrating metro network with access network, among which orthogonal frequency division multiplexing (OFDM)-based LR-PONs gain greater research interests due to their good robustness and high spectrum efficiency. In such attractive OFDM-based LR-PONs, however, it is still challenging to effectively provide video service, which is one of the most popular and profitable broadband services, for end users. Given that more video requesters (i.e., end users) far away from optical line terminal (OLT) are served in OFDM-based LR-PONs, it is efficiency-prohibitive to use traditional video delivery model, which relies on the OLT to transmit videos to requesters, for providing video service, due to the model will incur not only larger video playback delay but also higher downstream bandwidth consumption. In this paper, we propose a novel video caching scheme that to collaboratively cache videos on distributed optical network units (ONUs) which are closer to end users, and thus to timely and cost-efficiently provide videos for requesters by ONUs over OFDM-based LR-PONs. We firstly construct an OFDM-based LR-PON architecture to enable the cooperation among ONUs while caching videos. Given a limited storage capacity of each ONU, we then propose collaborative approaches to cache videos on ONUs with the aim to maximize the local video hit ratio (LVHR), i.e., the proportion of video requests that can be directly satisfied by ONUs, under diverse resources requirements and requests distributions of videos. Simulations are finally conducted to evaluate the efficiency of our proposed scheme.

  19. Bridging locoregional therapy for hepatocellular carcinoma prior to liver transplantation.

    PubMed

    Heckman, Jason T; Devera, Michael B; Marsh, J Wallis; Fontes, Paulo; Amesur, Nikhil B; Holloway, Shane E; Nalesnik, Michael; Geller, David A; Steel, Jennifer L; Gamblin, T Clark

    2008-11-01

    The impact of locoregional therapy prior to liver transplantation for hepatocellular carcinoma utilizing either transcatheter arterial chemoembolization (TACE), yttrium-90 ((90)Y), radiofrequency ablation (RFA), or resection prior to orthotopic liver transplantation (OLT) is largely unknown. We sought to examine locoregional therapies and their effect on survival compared with transplantation alone. A retrospective review of a prospectively collected database. 123 patients were included. Patients were analyzed in two groups. Group I consisted of 50 patients that received therapy (20 TACE; 16 (90)Y; 13 RFA, 3 resections). Group II consisted of 73 patients transplanted without therapy. Median list time was 28 days (range 2-260 days ) in group I, and 24 days (range 1-380 days) in group II. Median time from therapy to OLT was 3.8 months (range 9 days to 68 months). Twelve patients (24%) were successfully downstaged (8 TACE, 2 (90)Y, 2 RFA/resection). Overall 1-, 3-, and 5-year survival were 81%, 74%, and 74%, respectively. Survival was not statistically significantly different between the two groups (P = 0.53). The 12 patients downstaged did not have a significant difference in survival as compared with the patients who received therapy but did not respond or the patients who were transplanted without therapy (P = 0.76). Our report addresses locoregional therapy for hepatocellular carcinoma as a bridge to transplant. There was no statistical difference in overall survival between patients treated and those not treated prior to transplant. We provide further evidence that locoregional therapy is a safe tool for patients on the transplant list, does not impact survival, and can downstage selected patients to allow life-saving liver transplantation.

  20. Menstrual blood-derived mesenchymal stem cells differentiate into functional hepatocyte-like cells*

    PubMed Central

    Mou, Xiao-zhou; Lin, Jian; Chen, Jin-yang; Li, Yi-fei; Wu, Xiao-xing; Xiang, Bing-yu; Li, Cai-yun; Ma, Ju-ming; Xiang, Charlie

    2013-01-01

    Orthotopic liver transplantation (OLT) is the only proven effective treatment for both end-stage and metabolic liver diseases. Hepatocyte transplantation is a promising alternative for OLT, but the lack of available donor livers has hampered its clinical application. Hepatocyte-like cells (HLCs) differentiated from many multi-potential stem cells can help repair damaged liver tissue. Yet almost suitable cells currently identified for human use are difficult to harvest and involve invasive procedures. Recently, a novel mesenchymal stem cell derived from human menstrual blood (MenSC) has been discovered and obtained easily and repeatedly. In this study, we examined whether the MenSCs are able to differentiate into functional HLCs in vitro. After three weeks of incubation in hepatogenic differentiation medium containing hepatocyte growth factor (HGF), fibroblast growth factor-4 (FGF-4), and oncostain M (OSM), cuboidal HLCs were observed, and cells also expressed hepatocyte-specific marker genes including albumin (ALB), α-fetoprotein (AFP), cytokeratin 18/19 (CK18/19), and cytochrome P450 1A1/3A4 (CYP1A1/3A4). Differentiated cells further demonstrated in vitro mature hepatocyte functions such as urea synthesis, glycogen storage, and indocyanine green (ICG) uptake. After intrasplenic transplantation into mice with 2/3 partial hepatectomy, the MenSC-derived HLCs were detected in recipient livers and expressed human ALB protein. We also showed that MenSC-derived HLC transplantation could restore the serum ALB level and significantly suppressed transaminase activity of liver injury animals. In conclusion, MenSCs may serve as an ideal, easily accessible source of material for tissue engineering and cell therapy of liver tissues. PMID:24190442

  1. Gene Therapy for Liver Transplantation Using Adenoviral Vectors: CD40–CD154 Blockade by Gene Transfer of CD40Ig Protects Rat Livers from Cold Ischemia and Reperfusion Injury

    PubMed Central

    Ke, Bibo; Shen, Xiu-Da; Gao, Feng; Busuttil, Ronald W.; Löwenstein, Pedro R.; Castro, Maria G.; Kupiec-Weglinski, Jerzy W.

    2010-01-01

    Liver injury induced by ischemia/reperfusion (I/R) is the prime factor in delayed or loss graft function following transplantation. CD4+ T lymphocytes are key cellular mediators of antigen-independent inflammatory response triggered by I/R. We attempted to modulate rat liver I/R injury by targeted gene therapy with CD40Ig, which blocks the CD40–CD154 costimulation pathway. One hundred percent of Ad-CD40Ig-pretreated orthotopic liver transplants (OLTs) subjected to 24 h of cold (4°C) ischemia survived >14 days (vs 50% in untreated/Ad-β-gal groups). Ad-CD40Ig treatment decreased sGOT levels and depressed neutrophil infiltration, compared with controls. These functional data correlated with histological Suzuki’s grading of hepatic injury, which in untreated/Ad-β-gal groups showed severe necrosis (>60%) and moderate to severe sinusoidal congestion; the Ad-CD40Ig-pretreated group revealed minimal sinusoidal congestion/necrosis. Unlike in controls, OLT expression of mRNA coding for IL-2/IFN-γ remained depressed, whereas that of IL-4/IL-13 reciprocally increased in the Ad-CD40Ig group. Ad-CD40Ig reduced frequency of TUNEL+ cells and proapoptotic Caspase-3, but enhanced antioxidant HO-1 and antiapoptotic Bcl-2/Bcl-xl expression. Thus, prolonged blockade of CD40–CD154 by CD40Ig exerts potent cytoprotection against hepatic I/R injury. These results provide the rationale for a novel gene therapy approach to maximize the organ donor pool through the safer use of liver transplants exposed to prolonged cold ischemia. PMID:14741776

  2. Repeated Neck Restraint Stress Bidirectionally Modulates Excitatory Transmission in the Dentate Gyrus and Performance in a Hippocampus-dependent Memory Task.

    PubMed

    Spyrka, Jadwiga; Hess, Grzegorz

    2018-05-21

    The consequences of stress depend on characteristics of the stressor, including the duration of exposure, severity, and predictability. Exposure of mice to repeated neck restraint has been shown to bidirectionally modulate the potential for long-term potentiation (LTP) in the dentate gyrus (DG) in a manner dependent on the number of restraint repetitions, but the influence of repeated brief neck restraint on electrophysiology of single DG neurons has not yet been investigated. Here, we aimed at finding the effects of 1, 3, 7, 14, or 21 daily neck restraint sessions lasting 10 min on electrophysiological characteristics of DG granule cells as well as excitatory and inhibitory synaptic inputs to these neurons. While the excitability of DG granule cells and inhibitory synaptic transmission were unchanged, neck restraint decreased the frequency of spontaneous excitatory currents after three repetitions but enhanced it after 14 and 21 repetitions. The consequences of repeated neck restraint on hippocampus-dependent memory were investigated using the object location test (OLT). Neck restraint stress impaired cognitive performance in the OLT after three repetitions but improved it after 14 and 21 repetitions. Mice subjected to three neck restraint sessions displayed an increase in the measures of depressive and anxiety-like behaviors, however, prolongation of the exposure to neck restraint resulted in a gradual decline in the intensity of these measures. These data indicate that stress imposed by an increasing number of repeated neck restraint episodes bidirectionally modulates both excitatory synaptic transmission in the DG and cognitive performance in the object location memory task. Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.

  3. [Cause of death after liver transplantation: an analysis of 41 cases in 382 patients].

    PubMed

    Rayes, N; Bechstein, W O; Keck, H; Blumhardt, G; Lohmann, R; Neuhaus, P

    1995-01-01

    The aim of this study was to analyse the causes of death after liver transplantation in order to find and to avoid preventable fatal complications if possible. Between September 1988 and September 1993 415 orthotopic liver transplantations in 382 patients were performed at the Rudolf Virchow University Hospital in Berlin. During the same interval 41 (10.7%) of these patients died. Their clinical records were reviewed. The main cause of death was infection (29.3%), followed by recurrent malignancy (21.9%). Less patients died because of hepatitis B-reinfection (14.6%), chronic rejection (7.3%), hemorrhage (7.3%), cardiac failure (7.3%), trauma (4.8%), hypoxia (4.8%) and recurrence of alcoholic liver disease (4.8%). There was a wide spectrum of opportunistic infectious agents with CMV and Pneumocystis carinii being the most important pathogenic organisms. Only one isolated bacterial infection as principle cause of death was found. In all fatal infections the lung was the primary site of infection, 7 patients additionally developed sepsis. Altogether 75 patients (19.6%) with hepatitis B-cirrhosis were transplanted. Six of them (8%) developed a fatal hepatitis B-reinfection. Malignancy was the indication for OLT in 41 patients (10.7%). Six of these patients (14.6%) died because of recurrent tumor. Regarding the whole series, most deaths occurred four to twelve months (58.5%) and only five (12.2%) during the first month after OLT. Recurrence of primary disease is an important factor regarding total mortality. Therefore it is necessary to practise a careful selection of liver transplant recipients. In the future more attention needs to be drawn towards prevention, identification and management of opportunistic infections.

  4. Cognitive and Temperament Predictors of Executive Ability: Principles for Developing Leadership Capacity

    DTIC Science & Technology

    1993-05-01

    experience essays. Salmoni, A. W ., Schmidt, R. A., & Walter , C. B. (1985). Knowledge of results and motor learning: A review and critical reappraisal...Individuals as producers of their own development: A life-span perspective. New York: Academic Press. Tornow , W . W ., & Pinto, P. R. (1976). The development of...0a S C c -0 0 o 0, olt z - 1:.- 6 is a E 3 0: 060 ac g C : a o , ’ V1 0~ ~ OON g ~ ow aa Ab w .2 c C - too U0b 0b a- - 0 0 C O X WE-- 0 c a0 a = Cc

  5. Side-to-side cavocavostomy with an endovascular stapler: Rescue technique for severe hepatic vein and/or inferior vena cava outflow obstruction after liver transplantation using the piggyback technique.

    PubMed

    Quintini, Cristiano; Miller, Charles M; Hashimoto, Koji; Philip, Ding; Uso, Teresa Diago; Aucejo, Federico; Kelly, Dympna; Winans, Charles; Eghtesad, Bijan; Vogt, David; Fung, John

    2009-01-01

    Venous outflow obstruction is a rare but potentially lethal complication after orthotopic liver transplantation (OLT) with the "piggyback" technique. Therapeutic options include angioplasty with or without stent placement, surgical reconstruction of the venous anastomosis, and retransplantation. Surgical options are technically very challenging and the outcomes discouraging. We describe here two cases of venous outflow obstruction in recipients of piggyback liver grafts, one involving both the vena cava and hepatic veins and the other affecting only hepatic vein outflow. Both patients were treated successfully with side-to-side cavo-cavostomy using an endovascular (endo-GIA) stapler. This novel technique is fast and effective in resolving the outflow obstruction. Copyright 2008 AASLD.

  6. Intracranial tuberculoma in a liver transplant patient: first reported case and review of the literature.

    PubMed

    Henderson, Corey; Meyers, Burt; Humayun Gultekin, S; Liu, Bin; Zhang, David Y

    2003-01-01

    A 66-year-old female who had undergone an orthotopic liver transplant two years before admission was admitted with fever and neurological symptoms of several days' duration. Following an extensive work-up, which revealed positive intracranial lesions on computed typography and magnetic resonance imaging, the patient was begun on broad spectrum antimicrobials including corticosteroids. The patient responded though the etiology of infection remained unclear. After a stereotactic biopsy was performed revealing granulomas and acid-fast bacilli, the patient was started on antituberculous medications. A review of the literature reveals that the rare occurrence of intracranial tuberculoma should be considered in an orthotopic liver transplant (OLT) patient with central nervous system pathology.

  7. Computer Assisted Medical Diagnosis (CAMD) System Version 1.0 Technical Manual.

    DTIC Science & Technology

    1992-10-01

    Asaasasa S " "ft Mo Q0r "Ma.. @ ffM ’ 0e= 1aw- 0ý K. O - ^0e’O.t-,ý 4V .4 0;P S&. co *;:c Olt 0-oZo6.06-c v- f ’*-IA S0 . N Ml t* Q.0. L . ii a ,I...M& N.-2 1NNNNa N1ý*m N NN NNNNNN NN-NNNNNNN W.9 co 2 ;:N 2 .0 al .0-w -lI -, a? S -J w a a ( ( acca (a *. (a m. a a *.mo i-W - U - - - - U - 4--’- a-W

  8. Space Shuttle Endeavour Move

    NASA Image and Video Library

    2012-10-12

    The driver of the Over Land Transporter (OLT) is seen as he maneuvers the space shuttle Endeavour on the streets of Los Angeles as it heads to its new home at the California Science Center, Friday, Oct. 12, 2012. Endeavour, built as a replacement for space shuttle Challenger, completed 25 missions, spent 299 days in orbit, and orbited Earth 4,671 times while traveling 122,883,151 miles. Beginning Oct. 30, the shuttle will be on display in the CSC's Samuel Oschin Space Shuttle Endeavour Display Pavilion, embarking on its new mission to commemorate past achievements in space and educate and inspire future generations of explorers. Photo Credit: (NASA/Carla Cioffi)

  9. (LBA-and-WRM)-based DBA scheme for multi-wavelength upstream transmission supporting 10 Gbps and 1 Gbps in MAN

    NASA Astrophysics Data System (ADS)

    Zhang, Yuchao; Gan, Chaoqin; Gou, Kaiyu; Xu, Anni; Ma, Jiamin

    2018-01-01

    DBA scheme based on Load balance algorithm (LBA) and wavelength recycle mechanism (WRM) for multi-wavelength upstream transmission is proposed in this paper. According to 1 Gbps and 10 Gbps line rates, ONUs are grouped into different VPONs. To facilitate wavelength management, resource pool is proposed to record wavelength state. To realize quantitative analysis, a mathematical model describing metro-access network (MAN) environment is presented. To 10G-EPON upstream, load balance algorithm is designed to ensure load distribution fairness for 10G-OLTs. To 1G-EPON upstream, wavelength recycle mechanism is designed to share remained wavelengths. Finally, the effectiveness of the proposed scheme is demonstrated by simulation and analysis.

  10. Continued rapid glacier recession following the 1995 collapse of the Prince Gustav Ice Shelf on the Antarctic Peninsula (Invited)

    NASA Astrophysics Data System (ADS)

    Glasser, N. F.; Scambos, T. A.

    2009-12-01

    We use optical satellite imagery (ASTER and Landsat) to document changes in the Prince Gustav Ice Shelf (PGIS) and its tributary glaciers before and after its 1995 collapse. Interpretation of a pre-collapse Landsat 4-5 TM image acquired in February 1988 shows that the ice shelf was fed primarily by Sjogren Glacier from the Antarctic Peninsula and by Rhoss Glacier from James Ross Island (JRI). In 1988, the PGIS contained numerous structural discontinuities (rifts and crevasses), which collectively indicate that ice-shelf break-up had commenced at least seven years before collapse. Meltwater ponds and streams were also common across its surface. After the ice shelf collapsed, Rhoss Glacier became a tidewater glacier and has since experienced rapid and continued recession. Between January 2001 and December 2006 (six to eleven years after the collapse of the PGIS), the front of Rhoss Glacier receded a total of 13.6 km. We conclude that where tributary glaciers become tidewater glaciers they react to ice-shelf removal by rapid and continued recession and that the response time of glaciers on the Antarctic Peninsula to ice-shelf removal is measured on annual to decadal timescales. This rapid recession, coupled with previously documented tributary glacier thinning and acceleration, indicates that Antarctic Peninsula glaciers are extremely sensitive to ice-shelf collapse.

  11. [Extracorporeal reconstruction of arteries of a transplant of the liver for its subsequent implantation and surgical aspects of arterial anatomy the hepatoduodenal area].

    PubMed

    Khubutiia, M Sh; Guliaev, V A; Novruzbekov, M S; Lemenev, V L; Driaev, V T

    2014-01-01

    Orthotopic liver transplantation (OLT) remains the only and radical method of treating patients with terminal stages of chronic diffuse hepatic diseases (cirrhoses), of patients with various congenital metabolic lesions of the liver, autoimmune diseases characterized by lesions of bile ducts, as well as series of both primary and secondary tumorous hepatic lesions. Liver transplantation is one of the most complicated operative interventions. Difficulty of OLT is determined by multifactorial and well-coordinated work of various medical services at the pre-, intra- and postoperative stage of management. One of the important components of success in transplantation consists in providing adequate arterial blood flow of the transplanted organ, which is achieved by extracorporeal reconstruction of the transplant. Variants of arterial blood supply of the liver are observed in each third donor. These anatomical peculiarities increase probability of a surgical error, which is considerably higher if not taking into consideration the complicated anatomy of the donor organ and its misalignment with the anatomical peculiarities of the recipient. Surgeon's responsibility is especially great during taking out the liver from the donor, as well as during its preparation for implantation. Procurement of the liver and pancreas from the same donor for transplantation to two different recipients may be accompanied and followed by the so-called conflict of interests which the surgeon has to decide in favour of the both during procurement of the organ for its extracorporeal processing. The sequence of the presented surgical manipulations on hepatic and pancreatic vessels, as well as anatomical reference points make it possible to preserve the vessels of the maximum length for the both organs. A wide variety of the structure of hepatic vessels may be divided into three types, depending upon the number of the sources of arterial blood supply.

  12. Experimental demonstration of large capacity WSDM optical access network with multicore fibers and advanced modulation formats.

    PubMed

    Li, Borui; Feng, Zhenhua; Tang, Ming; Xu, Zhilin; Fu, Songnian; Wu, Qiong; Deng, Lei; Tong, Weijun; Liu, Shuang; Shum, Perry Ping

    2015-05-04

    Towards the next generation optical access network supporting large capacity data transmission to enormous number of users covering a wider area, we proposed a hybrid wavelength-space division multiplexing (WSDM) optical access network architecture utilizing multicore fibers with advanced modulation formats. As a proof of concept, we experimentally demonstrated a WSDM optical access network with duplex transmission using our developed and fabricated multicore (7-core) fibers with 58.7km distance. As a cost-effective modulation scheme for access network, the optical OFDM-QPSK signal has been intensity modulated on the downstream transmission in the optical line terminal (OLT) and it was directly detected in the optical network unit (ONU) after MCF transmission. 10 wavelengths with 25GHz channel spacing from an optical comb generator are employed and each wavelength is loaded with 5Gb/s OFDM-QPSK signal. After amplification, power splitting, and fan-in multiplexer, 10-wavelength downstream signal was injected into six outer layer cores simultaneously and the aggregation downstream capacity reaches 300 Gb/s. -16 dBm sensitivity has been achieved for 3.8 × 10-3 bit error ratio (BER) with 7% Forward Error Correction (FEC) limit for all wavelengths in every core. Upstream signal from ONU side has also been generated and the bidirectional transmission in the same core causes negligible performance degradation to the downstream signal. As a universal platform for wired/wireless data access, our proposed architecture provides additional dimension for high speed mobile signal transmission and we hence demonstrated an upstream delivery of 20Gb/s per wavelength with QPSK modulation formats using the inner core of MCF emulating a mobile backhaul service. The IQ modulated data was coherently detected in the OLT side. -19 dBm sensitivity has been achieved under the FEC limit and more than 18 dB power budget is guaranteed.

  13. Optimal Utilization of Donor Grafts With Extended Criteria

    PubMed Central

    Cameron, Andrew M.; Ghobrial, R Mark; Yersiz, Hasan; Farmer, Douglas G.; Lipshutz, Gerald S.; Gordon, Sherilyn A.; Zimmerman, Michael; Hong, Johnny; Collins, Thomas E.; Gornbein, Jeffery; Amersi, Farin; Weaver, Michael; Cao, Carlos; Chen, Tony; Hiatt, Jonathan R.; Busuttil, Ronald W.

    2006-01-01

    Objective: Severely limited organ resources mandate maximum utilization of donor allografts for orthotopic liver transplantation (OLT). This work aimed to identify factors that impact survival outcomes for extended criteria donors (ECD) and developed an ECD scoring system to facilitate graft-recipient matching and optimize utilization of ECDs. Methods: Retrospective analysis of over 1000 primary adult OLTs at UCLA. Extended criteria (EC) considered included donor age (>55 years), donor hospital stay (>5 days), cold ischemia time (>10 hours), and warm ischemia time (>40 minutes). One point was assigned for each extended criterion. Cox proportional hazard regression model was used for multivariate analysis. Results: Of 1153 allografts considered in the study, 568 organs exhibited no extended criteria (0 score), while 429, 135 and 21 donor allografts exhibited an EC score of 1, 2 and 3, respectively. Overall 1-year patient survival rates were 88%, 82%, 77% and 48% for recipients with EC scores of 0, 1, 2 and 3 respectively (P < 0.001). Adjusting for recipient age and urgency at the time of transplantation, multivariate analysis identified an ascending mortality risk ratio of 1.4 and 1.8 compared to a score of 0 for an EC score of 1, and 2 (P < 0.01) respectively. In contrast, an EC score of 3 was associated with a mortality risk ratio of 4.5 (P < 0.001). Further, advanced recipient age linearly increased the death hazard ratio, while an urgent recipient status increased the risk ratio of death by 50%. Conclusions: Extended criteria donors can be scored using readily available parameters. Optimizing perioperative variables and matching ECD allografts to appropriately selected recipients are crucial to maintain acceptable outcomes and represent a preferable alternative to both high waiting list mortality and to a potentially futile transplant that utilizes an ECD for a critically ill recipient. PMID:16772778

  14. Autoimmune conditions are associated with perioperative thrombotic complications in liver transplant recipients: A UNOS database analysis.

    PubMed

    Bezinover, Dmitri; Iskandarani, Khaled; Chinchilli, Vernon; McQuillan, Patrick; Saner, Fuat; Kadry, Zakiyah; Riley, Thomas R; Janicki, Piotr K

    2016-05-21

    End stage liver disease (ESLD) is associated with significant thrombotic complications. In this study, we attempted to determine if patients with ESLD, due to oncologic or autoimmune diseases, are susceptible to thrombosis to a greater extent than patients with ESLD due to other causes. In this retrospective study, we analyzed the UNOS database to determine the incidence of thrombotic complications in orthotopic liver transplant (OLT) recipients with autoimmune and oncologic conditions. Between 2000 and 2012, 65,646 OLTs were performed. We found 4,247 cases of preoperative portal vein thrombosis (PVT) and 1,233 cases of postoperative vascular thrombosis (VT) leading to graft failure. Statistical evaluation demonstrated that patients with either hepatocellular carcinoma (HCC) or autoimmune hepatitis (AIC) had a higher incidence of PVT (p = 0.05 and 0.03 respectively). Patients with primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC) and AIC had a higher incidence of postoperative VT associated with graft failure (p < 0.0001, p < 0.0001, p = 0.05 respectively). Patients with preoperative PVT had a higher incidence of postoperative VT (p < 0.0001). Multivariable logistic regression demonstrated that patients with AIC, and BMI ≥40, having had a transjugular intrahepatic portosystemic shunt, and those with diabetes mellitus were more likely to have preoperative PVT: odds ratio (OR)(1.36, 1.19, 1.78, 1.22 respectively). Patients with PSC, PBC, AIC, BMI ≤18, or with a preoperative PVT were more likely to have a postoperative VT: OR (1.93, 2.09, 1.64, 1.60, and 2.01, respectively). Despite the limited number of variables available in the UNOS database potentially related to thrombotic complications, this analysis demonstrates a clear association between autoimmune causes of ESLD and perioperative thrombotic complications. Perioperative management of patients at risk should include strategies to reduce the potential for these

  15. AWG-based WDM-PON monitoring system using an optical switch and a WDM filter

    NASA Astrophysics Data System (ADS)

    Liaw, S.-K.; Lai, Y.-T.; Chang, C.-L.; Shung, O.

    2008-09-01

    A new WDM-PON scheme with real-time monitoring based on a time-sharing method is proposed. It uses an optical time domain reflectometer (OTDR) to monitor multiple ports by integrating an optical switch (OSW) with a dense wavelength division multiplexer (DWDM) at the optical line terminal (OLT) site. Each downstream signal and its corresponding monitoring signal are separated by m times the free-space range (FSR) of an array waveguide grating (AWG). A bit error rate (BER) test in 2.5 Gb/s × 27 km is performed with and without turning on the OTDR. A small power penalty of 0.7 dB is observed compared to the back-to-back measurement.

  16. A novel survivable architecture for hybrid WDM/TDM passive optical networks

    NASA Astrophysics Data System (ADS)

    Qiu, Yang; Chan, Chun-Kit

    2014-02-01

    A novel tree-ring survivable architecture, which consists of an organization of a wavelength-division-multiplexing (WDM) tree from optical line terminal (OLT) to remote nodes (RNs) and a time division multiplexing (TDM) ring in each RN, is proposed for hybrid WDM/TDM passive optical networks. By utilizing the cyclic property of arrayed waveguide gratings (AWGs) and the single-ring topology among a group of optical network units (ONUs) in the remote node, not only the feeder and distribution fibers, but also any fiber failures in the RN rings are protected simultaneously. Five-Gbit/s transmissions under both normal working and protection modes were experimentally demonstrated and a traffic restoration time was successfully measured.

  17. Re-modulated technology of WDM-PON employing different DQPSK downstream signals

    NASA Astrophysics Data System (ADS)

    Gao, Chao; Xin, Xiang-jun; Yu, Chong-xiu

    2012-11-01

    This paper proposes a kind of modulation architecture for wavelength-division-multiplexing passive optical network (WDMPON) employing optical differential quadrature phase shift keying (DQPSK) downstream signals and two different modulation formats of re-modulated upstream signals. At the optical line terminal (OLT), 10 Gbit/s signal is modulated with DQPSK. At the optical network unit (ONU), part of the downstream signal is re-modulated with on-off keying (OOK) or inverse-return-to-zero (IRZ). Simulation results show the impact on the system employing NRZ, RZ and carrier-suppressed return-to-zero (CSRZ). The analyses also reflect that the architecture can restrain chromatic dispersion and channel crosstalk, which makes it the best architecture of access network in the future.

  18. The radio-on-fiber-wavelength-division-multiplexed-passive-optical network (WDM-RoF-PON) for wireless and wire layout with linearly-polarized dual-wavelength fiber laser and carrier reusing

    NASA Astrophysics Data System (ADS)

    Ji, Wei; Chang, Jun

    2013-07-01

    In this paper, we design a WDM-RoF-PON based on linearly-polarized dual-wavelength fiber laser and CSRZ-DPSK, which can achieve wire-line and wireless access synchronously. With the CSRZ-DPSK modulation, the wireless access in ONU can save RF source and the frequency of radio carrier can be controlled by OLT. The dual-wavelength fiber laser is the union light source of WDM-PON with polarization multiplexing. By the RSOA and downstream light source reusing, the ONU can save omit laser source and makes the WDM-PON to be colorless. The networking has the credible transmission property, including wireless access and fiber transmission. The networking also has excellent covering range.

  19. Reduced Transfusion During OLT by POC Coagulation Management and TEG Functional Fibrinogen: A Retrospective Observational Study.

    PubMed

    De Pietri, Lesley; Ragusa, Francesca; Deleuterio, Annalisa; Begliomini, Bruno; Serra, Valentina

    2016-01-01

    Patients undergoing orthotopic liver transplantation are at high risk of bleeding complications. Several Authors have shown that thromboelastography (TEG)-based coagulation management and the administration of fibrinogen concentrate reduce the need for blood transfusion. We conducted a single-center, retrospective cohort observational study (Modena Polyclinic, Italy) on 386 consecutive patients undergoing liver transplantation. We assessed the impact on resource consumption and patient survival after the introduction of a new TEG-based transfusion algorithm, requiring also the introduction of the fibrinogen functional thromboelastography test and a maximum amplitude of functional fibrinogen thromboelastography transfusion cutoff (7 mm) to direct in administering fibrinogen (2012-2014, n = 118) compared with a purely TEG-based algorithm previously used (2005-2011, n = 268). After 2012, there was a significant decrease in the use of homologous blood (1502 ± 1376 vs 794 ± 717 mL, P < 0.001), fresh frozen plasma (537 ± 798 vs 98 ± 375 mL, P < 0.001), and platelets (158 ± 280 vs 75 ± 148 mL, P < 0.005), whereas the use of fibrinogen increased (0.1 ± 0.5 vs 1.4 ± 1.8 g, P < 0.001). There were no significant differences in 30-day and 6-month survival between the 2 groups. The implementation of a new coagulation management method featuring the addition of the fibrinogen functional thromboelastography test to the TEG test according to an algorithm which provides for the administration of fibrinogen has helped in reducing the need for transfusion in patients undergoing liver transplantation with no impact on their survival.

  20. Natural radioactivity in stream sediments of Oltet River, Romania

    NASA Astrophysics Data System (ADS)

    Ion, Adriana

    2017-04-01

    The concentration of naturally occurring radionuclides (U-238, Th-232 and K-40) in stream sediments of the Oltet River was measured in order to establish the primary sources of radionuclides, the transport pathways and the geochemical factors favouring their mobilisation and concentration in the existing geological context. The Oltet River has a length of 185 Km and crosses the southern central part of the country, being the right tributary of the Olt River. The range in elevation of the watercourse varies between 1963 m in the springs area (Parîng Mountains) and 200 m at the confluence with the Olt River, whereas the relief of the Oltet Basin has a varied character, manifested by the presence of diverse forms of relief, starting with major mountainous heights and ending with low-lying plains regions. In cross section from North to South, the Olteț River cuts metamorphic rocks (schist, gneisses, quartzite, marble, mica-schist's), magmatic rocks (granite and granitoid massifs - intruded by veins of microgranite, aplite, pegmatite and lamprophyre) and limestone, followed by deposits composed of clays, marls, sands and gravels, that are characterized by the presence of lignite seams. 44 stream sediment samples were collected in summer of 2016 from sampling points distributed along the river with an equidistance of about 4 - 5 km. The activity concentrations of the U-238, Th-232 and K-40 were measured by gamma ray spectrometry using HPGe detector (ORTEC) with 26% relative efficiency in multilayer shielding. The reference materials used were IAEA - RGK-1 and IAEA - 314. Analysis was performed on the <2 mm fraction of sediment sample, each sample was counted for 24,000 s. U-238 specific activity in the stream sediments varies between 6.18 and 68.76 Bq/Kg and Th-232 specific activity from 8.12 to 89.28 Bq/Kg, whereas the K-40 specific activity in sediments ranges from 99.01 to 312.16 Bq/Kg. In the upper sector of the Oltet River, concentrations of U-238, Th-232 and K-40

  1. Micro-Pressure Sensors for Future Mars Missions

    NASA Technical Reports Server (NTRS)

    Catling, David C.

    1996-01-01

    The joint research interchange effort was directed at the following principal areas: u further development of NASA-Ames' Mars Micro-meteorology mission concept as a viable NASA space mission especially with regard to the science and instrument specifications u interaction with the flight team from NASA's New Millennium 'Deep-Space 2' (DS-2) mission with regard to selection and design of micro-pressure sensors for Mars u further development of micro-pressure sensors suitable for Mars The research work undertaken in the course of the Joint Research Interchange should be placed in the context of an ongoing planetary exploration objective to characterize the climate system on Mars. In particular, a network of small probes globally-distributed on the surface of the planet has often been cited as the only way to address this particular science goal. A team from NASA Ames has proposed such a mission called the Micrometeorology mission, or 'Micro-met' for short. Surface pressure data are all that are required, in principle, to calculate the Martian atmospheric circulation, provided that simultaneous orbital measurements of the atmosphere are also obtained. Consequently, in the proposed Micro-met mission a large number of landers would measure barometric pressure at various locations around Mars, each equipped with a micro-pressure sensor. Much of the time on the JRI was therefore spent working with the engineers and scientists concerned with Micro-met to develop this particular mission concept into a more realistic proposition.

  2. Advanced Motor-Controller Development.

    DTIC Science & Technology

    1983-06-22

    OUTPUTS: 16 BIT PROE:UCT IN ACCA , FiCC:B Oi:t2 -* 0011: 0172 B:7 .04E SIFY STA A MCAN:,* SF,-’E MULTIPLICAND 001t4 0175 iF CLF: A INIT RESUI_I_T AOll5...OL-:t41) 04: ELSE ACCA IS UNC:HANGED 0-142 01SF ::,A 0CI CLAMP 0’Fi A #0 TEST SIGN OF A C0It 0l91 E’E: fBM I C.LIPI EBRFNCH IF NEG 01t4 4 : : 001,15 19...ELSE S.:ET ACCA =-ACCB:1B TQJ5. 01 .’ NEG B .ESTOPE ACCE: 01155 C. l1’-9 E -9 PTI RETUR’N Al? I .9~~ _________ . .... ... | |- - - - . . rjOt :E

  3. Performance analysis of cross-seeding WDM-PON system using transfer matrix method

    NASA Astrophysics Data System (ADS)

    Simatupang, Joni Welman; Pukhrambam, Puspa Devi; Huang, Yen-Ru

    2016-12-01

    In this paper, a model based on the transfer matrix method is adopted to analyze the effects of Rayleigh backscattering and Fresnel multiple reflections on a cross-seeding WDM-PON system. As part of analytical approximation methods, this time-independent model is quite simple but very efficient when it is applied to various WDM-PON transmission systems, including the cross-seeding scheme. The cross seeding scheme is most beneficial for systems with low loop-back ONU gain or low reflection loss at the drop fiber for upstream data in bidirectional transmission. However for downstream data transmission, multiple reflections power could destroy the usefulness of the cross-seeding scheme when the reflectivity is high enough and the RN is positioned near OLT or close to ONU.

  4. Analysis of the influence of backscattered optical power over bidirectional PON links

    NASA Astrophysics Data System (ADS)

    Martínez, J. J.; Garcés, I.; López, A.; Villafranca, A.; Losada, M. A.

    2010-05-01

    Our aim is to describe the behavior of non-linear scattering effects that arise in standard single mode fiber (SMF), specifically scattering effects that propagate optical power in the reverse direction of the source signal such as Rayleigh Scattering (RS) and Brillouin Scattering (BS). For this purpose, the effects of backscattering phenomena over a bidirectional data transmission in a passive optical network (PON) scheme have been assessed. The impact of these high optical power components over reception at the optical line terminal (OLT) side has been determined when both links use the same wavelength. Bit Error Rate (BER) measurements have been performed with different transmission rates, using several techniques to mitigate the influence of backscattering over the received signal and considering cases with filtered and unfiltered BS.

  5. Sliceable transponders for metro-access transmission links

    NASA Astrophysics Data System (ADS)

    Wagner, C.; Madsen, P.; Spolitis, S.; Vegas Olmos, J. J.; Tafur Monroy, I.

    2015-01-01

    This paper presents a solution for upgrading optical access networks by reusing existing electronics or optical equipment: sliceable transponders using signal spectrum slicing and stitching back method after direct detection. This technique allows transmission of wide bandwidth signals from the service provider (OLT - optical line terminal) to the end user (ONU - optical network unit) over an optical distribution network (ODN) via low bandwidth equipment. We show simulation and experimental results for duobinary signaling of 1 Gbit/s and 10 Gbit/s waveforms. The number of slices is adjusted to match the lowest analog bandwidth of used electrical devices and scale from 2 slices to 10 slices. Results of experimental transmission show error free signal recovery by using post forward error correction with 7% overhead.

  6. Colorless ONU implementation for WDM-PON using direct-detection optical OFDM

    NASA Astrophysics Data System (ADS)

    Feng, Min; Luo, Qing-long; Bai, Cheng-lin

    2013-03-01

    A novel architecture for the colorless optical network unit (ONU) is proposed and experimentally demonstrated with direct-detection optical orthogonal frequency division multiplexing (DDO-OFDM). In this architecture, polarization-division multiplexing is used to reduce the cost at ONU. In optical line terminal (OLT), quadrature amplitude modulation (QAM) intensity-modulated OFDM signal with x-polarization at 10 Gbit/s is transmitted as downstream. At each ONU, the optical OFDM signal is demodulated with direct detection, and γ-polarization signal is modulated for upstream on-off keying (OOK) data at 5 Gbit/s. Simulation results show that the power penalty is negligible for both optical OFDM downstream and the on-off keying upstream signals after over 50 km single-mode fiber (SMF) transmission.

  7. The effect of ultrasonics on the strength properties of carbon steel processed by cold plastic deformation

    NASA Technical Reports Server (NTRS)

    Atanasiu, N.; Dragan, O.; Atanasiu, Z.

    1974-01-01

    A study was made of the influence of ultrasounds on the mechanical properties of OLT 35 carbon steel tubes cold-drawn on a plug ultrasonically activated by longitudinal waves. Experimental results indicate that: 1. The reduction in the values of the flow limit and tensile strength is proportional to the increase in acoustic energy introduced into the material subjected to deformation. 2. The diminution in influence of ultrasounds on tensile strength and flow rate that is due to an increased degree of deformation is explained by a reduction in specific density of the acoustic energy at the focus of deformation. 3. The relations calculated on the basis of the variation in the flow limit and tensile strength as a function of acoustic energy intensity was verified experimentally.

  8. Military Standard Generators Prototype Modifications. Volume 3. 60 kW DoD Generator Set

    DTIC Science & Technology

    1988-03-31

    14 JAN ., 17 :35: ’w. 6843 GEN S DS-00 273 . .. •- -,- - 32. 351 3 DE,-.. F Z EX ,-UST 2 895. 93 DEL;. F C REL!:7T 3 988.34 DEC-. F C 4 EXH-4AUST 4...33. 351 DEG. F C 20 GEN. FRAME TOP 11. 64 DEG. F C 2:1 GEN. FRAME BTTM 82. 15± DEG. F C 21 GEN. FRAME BTTM 113. i6 DEG. F C 2,. GEN. EXCITER 32. 992...DEG. F C 21 GEli . FRAME BTTM ±88.15 DEG. F S2 -EN. EXCITER 12. 49 DEG. F C 22 S-EN. EXCITER 185. 5 DEG. F 27 G2N. ’OLT. REG. 95. 459 DEG. F C 23 GEN

  9. Evaluation of the Impact of Towing DC-9 Transport Airplanes at Boston-Logan Airport.

    DTIC Science & Technology

    1980-05-01

    42- 22’ 71’ 02’ 12 1617 [t6 -96 F6p olt ln, slotr ADHA ,- r ’ C is on 11 f / 1 -3 . P o s.Nt Ofic /29/3 / 06/64 70 0 ftj. SE 42- 21’ 71’ W1 20 360 337 336...34A-A8 $64 DOUGLAS AIRCRAFT CO LONG BEACH CA PIG/ 1 /2 GG EVALUATION OF THE IMPACT OF TOWING DC-9 TRANSPORT AIRPLANES AT -ETC(U) MAY G0 E A HOOVER DOT...a -ib’f t0 tie U S. pubic through the Nat onj T, r ,ca, h -nrrmatior Ser\\ice, St 1 ’ o c: a q~nii 22161 - - ,.......~ - r’) C 2 TAINKD A ,4

  10. PWFQ: a priority-based weighted fair queueing algorithm for the downstream transmission of EPON

    NASA Astrophysics Data System (ADS)

    Xu, Sunjuan; Ye, Jiajun; Zou, Junni

    2005-11-01

    In the downstream direction of EPON, all ethernet frames share one downlink channel from the OLT to destination ONUs. To guarantee differentiated services, a scheduling algorithm is needed to solve the link-sharing issue. In this paper, we first review the classical WFQ algorithm and point out the shortcomings existing in the fair queueing principle of WFQ algorithm for EPON. Then we propose a novel scheduling algorithm called Priority-based WFQ (PWFQ) algorithm which distributes bandwidth based on priority. PWFQ algorithm can guarantee the quality of real-time services whether under light load or under heavy load. Simulation results also show that PWFQ algorithm not only can improve delay performance of real-time services, but can also meet the worst-case delay bound requirements.

  11. Rapid generation of functional hepatocyte-like cells from human adipose-derived stem cells.

    PubMed

    Fu, Yanli; Deng, Jie; Jiang, Qingyuan; Wang, Yuan; Zhang, Yujing; Yao, Yunqi; Cheng, Fuyi; Chen, Xiaolei; Xu, Fen; Huang, Meijuan; Yang, Yang; Zhang, Shuang; Yu, Dechao; Zhao, Robert Chunhua; Wei, Yuquan; Deng, Hongxin

    2016-08-05

    Liver disease is a major cause of death worldwide. Orthotropic liver transplantation (OLT) represents the only effective treatment for patients with liver failure, but the increasing demand for organs is unfortunately so great that its application is limited. Hepatocyte transplantation is a promising alternative to OLT for the treatment of some liver-based metabolic disorders or acute liver failure. Unfortunately, the lack of donor livers also makes it difficult to obtain enough viable hepatocytes for hepatocyte-based therapies. Currently, a fundamental solution to this key problem is still lacking. Here we show a novel non-transgenic protocol that facilitates the rapid generation of functional induced hepatocytes (iHeps) from human adipose-derived stem cells (hADSCs), providing a source of available cells for autologous hepatocytes to treat liver disease. We used collagenase digestion to isolate hADSCs. The surface marker was detected by flow cytometry. The multipotential differentiation potency was detected by induction into adipocytes, osteocytes, and chondrocytes. Passage 3-7 hADSCs were induced into iHeps using an induction culture system composed of small molecule compounds and cell factors. Primary cultured hADSCs presented a fusiform or polygon appearance that became fibroblast-like after passage 3. More than 95 % of the cells expressed the mesenchymal cell markers CD29, CD44, CD166, CD105, and CD90. hADSCs possessed multipotential differentiation towards adipocytes, osteocytes, and chondrocytes. We rapidly induced hADSCs into iHeps within 10 days in vitro; the cellular morphology changed from fusiform to close-connected cubiform, which was similar to hepatocytes. After induction, most of the iHeps co-expressed albumin and alpha-1 antitrypsin; they also expressed mature hepatocyte special genes and achieved the basic functions of hepatocyte. Moreover, iHep transplantation could improve the liver function of acute liver-injured NPG mice and prolong life. We

  12. A subclinical high tricuspid regurgitation pressure gradient independent of the mean pulmonary artery pressure is a risk factor for the survival after living donor liver transplantation.

    PubMed

    Saragai, Yosuke; Takaki, Akinobu; Umeda, Yuzo; Matsusaki, Takashi; Yasunaka, Tetsuya; Oyama, Atsushi; Kaku, Ryuji; Nakamura, Kazufumi; Yoshida, Ryuichi; Nobuoka, Daisuke; Kuise, Takashi; Takagi, Kosei; Adachi, Takuya; Wada, Nozomu; Takeuchi, Yasuto; Koike, Kazuko; Ikeda, Fusao; Onishi, Hideki; Shiraha, Hidenori; Nakamura, Shinichiro; Morimatsu, Hiroshi; Ito, Hiroshi; Fujiwara, Toshiyoshi; Yagi, Takahito; Okada, Hiroyuki

    2018-05-15

    Portopulmonary hypertension (POPH) is characterized by pulmonary vasoconstriction, while hepatopulmonary syndrome (HPS) is characterized by vasodilation. Definite POPH is a risk factor for the survival after orthotopic liver transplantation (OLT), as the congestive pressure affects the grafted liver, while subclinical pulmonary hypertension (PH) has been acknowledged as a non-risk factor for deceased donor OLT. Given that PH measurement requires cardiac catheterization, the tricuspid regurgitation pressure gradient (TRPG) measured by echocardiography is used to screen for PH and congestive pressure to the liver. We investigated the impact of a subclinical high TRPG on the survival of small grafted living donor liver transplantation (LDLT). We retrospectively analyzed 84 LDLT candidates. Patients exhibiting a TRPG ≥25 mmHg on echocardiography were categorized as potentially having liver congestion (subclinical high TRPG; n = 34). The mean pulmonary artery pressure (mPAP) measured after general anesthesia with FIO 2 0.6 (mPAP-FIO 2 0.6) was also assessed. Patients exhibiting pO 2  < 80 mmHg and an alveolar-arterial oxygen gradient (AaDO 2 ) ≥ 15 mmHg were categorized as potentially having HPS (subclinical HPS; n = 29). The clinical course after LDLT was investigated according to subclinical high TRPG. A subclinical high TRPG (p = 0.012) and older donor age (p = 0.008) were correlated with a poor 40-month survival. Although a higher mPAP-FIO 2 0.6 was expected to correlate with a worse survival, a high mPAP-FIO 2 0.6 with a low TRPG was associated with high frequency complicating subclinical HPS and a good survival, suggesting a reduction in the PH pressure via pulmonary shunt. In cirrhosis patients, mPAP-FIO 2 0.6 may not accurately reflect the congestive pressure to the liver, as the pressure might escape via pulmonary shunt. A subclinical high TRPG is an important marker for predicting a worse survival after LDLT, possibly reflecting

  13. Implantability, Complications, and Follow-Up After Transjugular Intrahepatic Portosystemic Stent-Shunt Creation With the 6F Self-Expanding Sinus-SuperFlex-Visual Stent.

    PubMed

    Spira, Daniel; Wiskirchen, Jakub; Lauer, Ulrich; Ketelsen, Dominik; Nikolaou, Konstantin; Wiesinger, Benjamin

    2016-07-01

    The transjugular intrahepatic portosystemic stent-shunt (TIPSS) builds a shortcut between the portal vein and a liver vein, and represents a sophisticated alternative to open surgery in the management of portal hypertension or its complications. To describe clinical experiences with a low-profile nitinol stent system in TIPSS creation, and to assess primary and long-term success. Twenty-six patients (5 females, 21 males; mean age 54.6 years) were treated using a low-profile 6F self-expanding sinus-SuperFlex-Visual stent system. The indication for TIPSS creation was refractory bleeding in 9 of the 26 patients, refractory ascites in 18 patients, and acute thrombosis of the portal vein confluence in one patient. Portosystemic pressure gradients before and after TIPSS, periprocedural and long-term complications, and the time to orthotopic liver transplantation (OLT) or death were recorded. The portosystemic pressure gradient was significantly reduced, from 20.9 ± 6.3 mmHg before to 8.2 ± 2.3 mmHg after TIPSS creation (P < 0.001). Procedure-related complications included acute tract occlusion (n = 2), liver hematoma (n = 1), hepatic encephalopathy (n = 1), and cardiac failure (n = 1). Three of the 26 patients had late-onset TIPSS occlusion (at 12, 12, and 39 months after TIPSS creation). Three patients died within one week after the procedure due to their poor general condition (multiorgan failure, acute respiratory distress syndrome, necrotizing pancreatitis, and aspiration pneumonia). Another four patients succumbed to their underlying advanced liver disease within one year after TIPSS insertion. Seven patients underwent OLT at a mean time of 9.4 months after TIPSS creation. The sinus-SuperFlex-Visual stent system can be safely deployed as a TIPSS device. The pressure gradient reduction was clinically sufficient to treat the patients' symptoms, and periprocedural complications were due to the TIPSS procedure per se rather than to the particular stent system employed

  14. Comparison of hepatic MDCT, MRI, and DSA to explant pathology for the detection and treatment planning of hepatocellular carcinoma.

    PubMed

    Ladd, Lauren M; Tirkes, Temel; Tann, Mark; Agarwal, David M; Johnson, Matthew S; Tahir, Bilal; Sandrasegaran, Kumaresan

    2016-12-01

    The diagnosis and treatment plan for hepatocellular carcinoma (HCC) can be made from radiologic imaging. However, lesion detection may vary depending on the imaging modality. This study aims to evaluate the sensitivities of hepatic multidetector computed tomography (MDCT), magnetic resonance imaging (MRI), and digital subtraction angiography (DSA) in the detection of HCC and the consequent management impact on potential liver transplant patients. One hundred and sixteen HCC lesions were analyzed in 41 patients who received an orthotopic liver transplant (OLT). All of the patients underwent pretransplantation hepatic DSA, MDCT, and/or MRI. The imaging results were independently reviewed retrospectively in a blinded fashion by two interventional and two abdominal radiologists. The liver explant pathology was used as the gold standard for assessing each imaging modality. The sensitivity for overall HCC detection was higher for cross-sectional imaging using MRI (51.5%, 95% confidence interval [CI]=36.2-58.4%) and MDCT (49.8%, 95% CI=43.7-55.9%) than for DSA (41.7%, 95% CI=36.2-47.3%) ( P =0.05). The difference in false-positive rate was not statistically significant between MRI (22%), MDCT (29%), and DSA (29%) ( P =0.67). The sensitivity was significantly higher for detecting right lobe lesions than left lobe lesions for all modalities (MRI: 56.1% vs. 43.1%, MDCT: 55.0% vs. 42.0%, and DSA: 46.9% vs. 33.9%; all P <0.01). The sensitivities of the three imaging modalities were also higher for lesions ≥2 cm vs. <2 cm (MRI: 73.4% vs. 32.7%, MDCT: 66.9% vs. 33.8%, and DSA: 62.2% vs. 24.1%; all P <0.01). The interobserver correlation was rated as very good to excellent. The sensitivity for detecting HCC is higher for MRI and MDCT than for DSA, and so cross-sectional imaging modalities should be used to evaluate OLT candidacy.

  15. Study of bidirectional broadband passive optical network (BPON) using EDFA

    NASA Astrophysics Data System (ADS)

    Almalaq, Yasser

    Optical line terminals (OLTs) and number of optical network units (ONUs) are two main parts of passive optical network (PON). OLT is placed at the central office of the service providers, the ONUs are located near to the end subscribers. When compared with point-to-point design, a PON decreases the number of fiber used and central office components required. Broadband PON (BPON), which is one type of PON, can support high-speed voice, data and video services to subscribers' residential homes and small businesses. In this research, by using erbium doped fiber amplifier (EDFA), the performance of bi-directional BPON is experimented and tested for both downstream and upstream traffic directions. Ethernet PON (E-PON) and gigabit PON (G-PON) are the two other kinds of passive optical network besides BPON. The most beneficial factor of using BPON is it's reduced cost. The cost of the maintenance between the central office and the users' side is suitable because of the use of passive components, such as a splitter in the BPON architecture. In this work, a bidirectional BPON has been analyzed for both downstream and upstream cases by using bit error rate analyzer (BER). BER analyzers test three factors that are the maximum Q factor, minimum bit error rate, and eye height. In other words, parameters such as maximum Q factor, minimum bit error rate, and eye height can be analyzed utilized a BER tester. Passive optical components such as a splitter, optical circulator, and filters have been used in modeling and simulations. A 12th edition Optiwave simulator has been used in order to analyze the bidirectional BPON system. The system has been tested under several conditions such as changing the fiber length, extinction ratio, dispersion, and coding technique. When a long optical fiber above 40km was used, an EDFA was used in order to improve the quality of the signal.

  16. 1.25-3.125 Gb/s per user PON with RSOA as phase modulator for statistical wavelength ONU

    NASA Astrophysics Data System (ADS)

    Chu, Guang Yong; Polo, Victor; Lerín, Adolfo; Tabares, Jeison; Cano, Iván N.; Prat, Josep

    2015-12-01

    We report a new scheme to support, cost efficiently, ultra-dense wavelength division multiplexing (UDWDM) for optical access networks. As validating experiment, we apply phase modulation of a reflective semiconductor optical amplifier (RSOA) at the ONU with a single DFB, and simplified coherent receiver at OLT for upstream. We extend the limited 3-dB modulation bandwidth of available uncooled To-can packaged RSOA (~400 MHz) and operate it at 3.125 Gb/s with the optimal performance for phase modulation using small and large signal measurement characteristics. The optimal condition is selected at input power of 0 dBm, with 70 mA bias condition. The sensitivities at 3.125 Gb/s (at BER=10-3) for heterodyne and intradyne detection reach -34.3 dBm and -38.8 dBm, respectively.

  17. Hierarchy Bayesian model based services awareness of high-speed optical access networks

    NASA Astrophysics Data System (ADS)

    Bai, Hui-feng

    2018-03-01

    As the speed of optical access networks soars with ever increasing multiple services, the service-supporting ability of optical access networks suffers greatly from the shortage of service awareness. Aiming to solve this problem, a hierarchy Bayesian model based services awareness mechanism is proposed for high-speed optical access networks. This approach builds a so-called hierarchy Bayesian model, according to the structure of typical optical access networks. Moreover, the proposed scheme is able to conduct simple services awareness operation in each optical network unit (ONU) and to perform complex services awareness from the whole view of system in optical line terminal (OLT). Simulation results show that the proposed scheme is able to achieve better quality of services (QoS), in terms of packet loss rate and time delay.

  18. Suppression of optical beat interference-noise in orthogonal frequency division multiple access-passive optical network link using self-homodyne balanced detection

    NASA Astrophysics Data System (ADS)

    Won, Yong-Yuk; Jung, Sang-Min; Han, Sang-Kook

    2014-08-01

    A new technique, which reduces optical beat interference (OBI) noise in orthogonal frequency division multiple access-passive optical network (OFDMA-PON) links, is proposed. A self-homodyne balanced detection, which uses a single laser for the optical line terminal (OLT) as well as for the optical network unit (ONU), reduces OBI noise and also improves the signal to noise ratio (SNR) of the discrete multi-tone (DMT) signal. The proposed scheme is verified by transmitting quadrature phase shift keying (QPSK)-modulated DMT signal over a 20-km single mode fiber. The optical signal to noise ratio (OSNR), that is required for BER of 10-5, is reduced by 2 dB in the balanced detection compared with a single channel due to the cancellation of OBI noise in conjunction with the local laser.

  19. Power Budget Analysis of Colorless Hybrid WDM/TDM-PON Scheme Using Downstream DPSK and Re-modulated Upstream OOK Data Signals

    NASA Astrophysics Data System (ADS)

    Khan, Yousaf; Afridi, Muhammad Idrees; Khan, Ahmed Mudassir; Rehman, Waheed Ur; Khan, Jahanzeb

    2014-09-01

    Hybrid wavelength-division multiplexed/time-division multiplexed passive optical access networks (WDM/TDM-PONs) combine the advance features of both WDM and TDM PONs to provide a cost-effective access network solution. We demonstrate and analyze the transmission performances and power budget issues of a colorless hybrid WDM/TDM-PON scheme. A 10-Gb/s downstream differential phase shift keying (DPSK) and remodulated upstream on/off keying (OOK) data signals are transmitted over 25 km standard single mode fiber. Simulation results show error free transmission having adequate power margins in both downstream and upstream transmission, which prove the applicability of the proposed scheme to future passive optical access networks. The power budget confines both the PON splitting ratio and the distance between the Optical Line Terminal (OLT) and Optical Network Unit (ONU).

  20. Energy-efficient orthogonal frequency division multiplexing-based passive optical network based on adaptive sleep-mode control and dynamic bandwidth allocation

    NASA Astrophysics Data System (ADS)

    Zhang, Chongfu; Xiao, Nengwu; Chen, Chen; Yuan, Weicheng; Qiu, Kun

    2016-02-01

    We propose an energy-efficient orthogonal frequency division multiplexing-based passive optical network (OFDM-PON) using adaptive sleep-mode control and dynamic bandwidth allocation. In this scheme, a bidirectional-centralized algorithm named the receiver and transmitter accurate sleep control and dynamic bandwidth allocation (RTASC-DBA), which has an overall bandwidth scheduling policy, is employed to enhance the energy efficiency of the OFDM-PON. The RTASC-DBA algorithm is used in an optical line terminal (OLT) to control the sleep mode of an optical network unit (ONU) sleep and guarantee the quality of service of different services of the OFDM-PON. The obtained results show that, by using the proposed scheme, the average power consumption of the ONU is reduced by ˜40% when the normalized ONU load is less than 80%, compared with the average power consumption without using the proposed scheme.

  1. Adaptive upstream optical power adjustment depending on required power budget in PON access

    NASA Astrophysics Data System (ADS)

    Yeh, C. H.; Chow, C. W.; Liu, Y. L.

    2012-11-01

    According to the present passive optical network (PON) standard, the fiber transmission lengths are from 500 m to 20 km between the optical line terminal (OLT) and different optical network units (ONUs). It will result in difference power losses (ΔPloss) from 4 to 5 dB. Hence, we propose to adjust adaptively the output optical power of the upstream laser diode (LD) depending on the different fiber lengths. With the different fiber transmission lengths, we can properly adjust the bias current and modulation index of upstream LD for energy-saving. We characterize and analyze experimentally the relationship of output optical power and modulation amplitude Vamp under different fiber transmissions in PON access. Moreover, due to the adaptive power control of upstream signal, the optical upstream equalization also can be retrieved with power variation of 1.1 dB in this experiment.

  2. An upstream burst-mode equalization scheme for 40 Gb/s TWDM PON based on optimized SOA cascade

    NASA Astrophysics Data System (ADS)

    Sun, Xiao; Chang, Qingjiang; Gao, Zhensen; Ye, Chenhui; Xiao, Simiao; Huang, Xiaoan; Hu, Xiaofeng; Zhang, Kaibin

    2016-02-01

    We present a novel upstream burst-mode equalization scheme based on optimized SOA cascade for 40 Gb/s TWDMPON. The power equalizer is placed at the OLT which consists of two SOAs, two circulators, an optical NOT gate, and a variable optical attenuator. The first SOA operates in the linear region which acts as a pre-amplifier to let the second SOA operate in the saturation region. The upstream burst signals are equalized through the second SOA via nonlinear amplification. From theoretical analysis, this scheme gives sufficient dynamic range suppression up to 16.7 dB without any dynamic control or signal degradation. In addition, a total power budget extension of 9.3 dB for loud packets and 26 dB for soft packets has been achieved to allow longer transmission distance and increased splitting ratio.

  3. Bandwidth efficient bidirectional 5 Gb/s overlapped-SCM WDM PON with electronic equalization and forward-error correction.

    PubMed

    Buset, Jonathan M; El-Sahn, Ziad A; Plant, David V

    2012-06-18

    We demonstrate an improved overlapped-subcarrier multiplexed (O-SCM) WDM PON architecture transmitting over a single feeder using cost sensitive intensity modulation/direct detection transceivers, data re-modulation and simple electronics. Incorporating electronic equalization and Reed-Solomon forward-error correction codes helps to overcome the bandwidth limitation of a remotely seeded reflective semiconductor optical amplifier (RSOA)-based ONU transmitter. The O-SCM architecture yields greater spectral efficiency and higher bit rates than many other SCM techniques while maintaining resilience to upstream impairments. We demonstrate full-duplex 5 Gb/s transmission over 20 km and analyze BER performance as a function of transmitted and received power. The architecture provides flexibility to network operators by relaxing common design constraints and enabling full-duplex operation at BER ∼ 10(-10) over a wide range of OLT launch powers from 3.5 to 8 dBm.

  4. CACDA JIFFY III War Game. Volume V. Programmer’s Manual.

    DTIC Science & Technology

    1980-10-01

    60 ONAT1,OLTE-ETER SRC(ENO TO 0113-- .1 066153 REA24A.L265) ASRtc flant54 CALL aPt N(IFIT93L1-O 5060155 1265 PORN *?AM180015 IF1ASRC*EO.3HEND) 60 TO 16...POIN-/9799,ITE4 * iLOST") 12699r IF(IRUMe.Nl.tlPSIN7 c9604X9ET’ZLl. 2273 13 990 PoRn .*TI" .?X.!2,5W*F6#D 12T20 IFLAG2ut Z 33 -UIll-Offf THUE k COUTPUT...A344b3299999. sfl IFIIHI’l&.NE.9q99@.3G0 ’?O 160 IZ TNH S CLNP!~CORC NOT FOUND- dOG IT TO MISTORY FILE 35C67: co 150 1.390 9O £1411 3.. ;5C69: 150 C

  5. Multi-band transit observations of the TrES-2b exoplanet

    NASA Astrophysics Data System (ADS)

    Mislis, D.; Schröter, S.; Schmitt, J. H. M. M.; Cordes, O.; Reif, K.

    2010-02-01

    We present a new data set of transit observations of the TrES-2b exoplanet taken in spring 2009, using the 1.2 m Oskar-Lühning telescope (OLT) of Hamburg Observatory and the 2.2 m telescope at Calar Alto Observatory using BUSCA (Bonn University Simultaneous CAmera). Both the new OLT data, taken with the same instrumental setup as our data taken in 2008, as well as the simultaneously recorded multicolor BUSCA data confirm the low inclination values reported previously, and in fact suggest that the TrES-2b exoplanet has already passed the first inclination threshold (imin,1 = 83.417°) and is not eclipsing the full stellar surface any longer. Using the multi-band BUSCA data we demonstrate that the multicolor light curves can be consistently fitted with a given set of limb darkening coefficients without the need to adjust these coefficients, and further, we can demonstrate that wavelength dependent stellar radius changes must be small as expected from theory. Our new observations provide further evidence for a change of the orbit inclination of the transiting extrasolar planet TrES-2b reported previously. We examine in detail possible causes for this inclination change and argue that the observed change should be interpreted as nodal regression. While the assumption of an oblate host star requires an unreasonably large second harmonic coefficient, the existence of a third body in the form of an additional planet would provide a very natural explanation for the observed secular orbit change. Given the lack of clearly observed short-term variations of transit timing and our observed secular nodal regression rate, we predict a period between approximately 50 and 100 days for a putative perturbing planet of Jovian mass. Such an object should be detectable with present-day radial velocity (RV) techniques, but would escape detection through transit timing variations. Photometric transit data are only available in electronic form at the CDS via anonymous ftp to cdsarc

  6. Neodymium Isotopic Compositions of the Titanite Reference Materials Used in U-Pb Geochronology

    NASA Astrophysics Data System (ADS)

    Ma, Q.; Yang, Y.; Zhao, Z.

    2017-12-01

    Titanite (CaTiSiO5) is a widespread mineral and preferentially incorporates considerable uranium and significant light rare earth elements (LREEs) in its structure. Geochronology based upon U-Pb and Pb-Pb analyses of titanite has proven to be useful for understanding the P-T-t evolution of many igneous, metamorphic and hydrothermally altered rock samples (Scott and St-Onge, 1995). In the meantime, Sm-Nd isotopic composition in single titanite can be used to obtain initial Nd isotope composition at the time of titanite crystallization when combined with its U-Pb age, making titanite the most versatile mineral for dating metamorphism and tracing hydrothermal source (Amelin et al., 2009). The widely utilized in situ analyses by SIMS and LA-(MC)-ICP-MS have emphasized the significance for uniform and homogeneous reference materials for external correction (Liu et al., 2012, Sun et al., 2012, Yang et al., 2014). Here, we present U-Pb ages and Sm-Nd isotope analyses of twelve natural titanite crystals (12YQ82, T004, Ontario, BLR-1, OLT1, Khan, Qinghu, TLS-36, NW-IOA, C253, Pakistan and MKED1) acquired by Agilent 7500a Q-ICP-MS and Neptune MC-ICP-MS, respectively, combined a 193 nm ArF excimer laser ablation system. For U-Pb dating, elemental fractionation and instrumental drift were externally corrected using MKED1 titanite standard, showing results of U-Pb analyses all within error of those recommended values. With respect to Sm-Nd isotopes, we employed the interference-free 147Sm/149Sm to deduct 144Sm isobaric interference on 144Nd, and the fractionation between 147Sm and 144Nd was calibrated using BLR-1 titanite, which is proved homogenous in Sm-Nd isotopic system. The obtained Sm-Nd isotopic compositions for natural titanite samples are all consistent with those values determined by isotope dilution (ID) MC-ICP-MS, demonstrating the precision and accuracy currently available for in situ Sm-Nd analyses. Our results demonstrate that BLR-1, OLT1 and Ontario titanites

  7. Study on the capability of four-level partial response equalization in RSOA-based WDM-PON

    NASA Astrophysics Data System (ADS)

    Guo, Qi; Tran, An Vu

    2010-12-01

    The expected development of advanced video services with HDTV quality demands the delivery of more than Gb/s link to end users across the last mile connection. Future access networks are also required to have long reach for reduction in the number of central offices (CO). Fueled by those requirements, we propose a novel equalization scheme that increases the capacity and reach of the wavelength division multiplexing passive optical network (WDM-PON) based on a low bandwidth reflective semiconductor optical amplifier (RSOA). We investigate the characteristics of 10 Gb/s upstream transmission in WDM-PON using RSOA with only 1.2 GHz electrical bandwidth and various lengths of fiber. It is proven that the proposed four-level partial response equalizer (PRE) is capable of mitigating the impact of ISI in the received signals from optical network units (ONU) located 0 km to 75 km away from the optical line terminal (OLT).

  8. Three-mode mode-division-multiplexing passive optical network over 12-km low mode-crosstalk FMF using all-fiber mode MUX/DEMUX

    NASA Astrophysics Data System (ADS)

    Ren, Fang; Li, Juhao; Wu, Zhongying; Hu, Tao; Yu, Jinyi; Mo, Qi; He, Yongqi; Chen, Zhangyuan; Li, Zhengbin

    2017-01-01

    We propose three-mode mode-division-multiplexing passive optical network (MDM-PON) based on low mode-crosstalk few-mode fiber (FMF) and all-fiber mode multiplexer/demultiplexer (MUX/DEMUX). The FMF with step-index profile is designed and fabricated for effectively three-independent-spatial-mode transmission and low mode-crosstalk for MDM-PON transmission. The all-fiber mode MUX/DEMUX are composed of cascaded mode selective couplers (MSCs), which simultaneously multiplex or demultiplex multiple modes. Based on the low mode-crosstalk of the FMF and all-fiber mode MUX/DEMUX, each optical network unit (ONU) communicates with the optical line terminal (OLT) independently utilizing a different optical linearly polarized (LP) spatial mode in MDM-PON system. We experimentally demonstrate MDM-PON transmission of three independent-spatial-modes over 12-km FMF with 10-Gb/s optical on-off keying (OOK) signal and direct detection.

  9. A long-reach WDM passive optical network enabling broadcasting service with centralized light source

    NASA Astrophysics Data System (ADS)

    Liu, D.; Tang, M.; Fu, S.; Liu, D.; Shum, P.

    2012-02-01

    We propose a long-reach wavelength-division-multiplexed (WDM) passive optical network (PON) to provide conventional point-to-point (P2P) data and downstream broadcasting service simultaneously by superimposing, for each WDM channel, the differential-phase-shift-keying (DPSK) broadcasting signal with the subcarrier multiplexing (SCM) modulated downstream P2P signal, at the optical line terminal (OLT). In the optical network units (ONUs), by re-modulating part of the downstream signal with a reflective semiconductor optical amplifier (RSOA), we realize color-less ONUs for upstream data transmission. The proposed scheme is numerically verified with a 5 Gb/s downstream P2P signal and broadcasting services, as well as 2.5 Gb/s upstream data through a 60 km bidirectional fiber link. In particular, the influence of the downstream lightwave's optical carrier-subcarrier ratio (OCSR) on the system performance is also investigated.

  10. TWC and AWG based optical switching structure for OVPN in WDM-PON

    NASA Astrophysics Data System (ADS)

    Bai, Hui-feng; Chen, Yu-xin; Wang, Qin

    2015-03-01

    With the rapid development of optical elements with large capacity and high speed, the network architecture is of great importance in determing the performance of wavelength division multiplexing passive optical network (WDM-PON). This paper proposes a switching structure based on the tunable wavelength converter (TWC) and the arrayed-waveguide grating (AWG) for WDM-PON, in order to provide the function of opitcal virtual private network (OVPN). Using the tunable wavelength converter technology, this switch structure is designed and works between the optical line terminal (OLT) and optical network units (ONUs) in the WDM-PON system. Moreover, the wavelength assignment of upstream/downstream can be realized and direct communication between ONUs is also allowed by privite wavelength channel. Simulation results show that the proposed TWC and AWG based switching structure is able to achieve OVPN function and to gain better performances in terms of bite error rate (BER) and time delay.

  11. Summary of Synoptic Meteorological Observations (SSMO). South America and Selected Island Coastal Marine Areas, East Coast. Volume 2. Area 9-Rio de Janeiro, Area 10-Florianopolis, Area 11-Porto Alegre, Area 12-Buenos Aires, Area 13-Bahia Blanca, Area 14-Rawson, Area 15-Puerto Deseado, Area 16-Magellan Strain East.

    DTIC Science & Technology

    1977-06-01

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  12. Acute hepatitis B in a patient with OLT during treatment with peg-interferon and ribavirin for hepatitis C recurrence.

    PubMed

    Biliotti, Elisa; Zacharia, Sabu; Grieco, Stefania; Spaziante, Martina; Giusto, Michela; Merli, Manuela; Gallinaro, Valentina; Taliani, Gloria

    2012-12-01

    The course and outcome of acute viral hepatitis in liver transplanted patients with hepatitis C recurrence are unknown. Here we describe a patient who presented with acute hepatitis B infection while on treatment with peg-interferon and ribavirin for hepatitis C recurrence after liver transplantation. A nucleoside analogue was added (entecavir) and the patient cleared hepatitis C virus (HCV) infection and seroconverted to anti-HBs. In this case, the acute hepatitis B virus (HBV) infection might have contributed to the clearance of HCV, the concomitant immunosuppression might have lead to the slow clearance of HBV infection, and the combined antiviral therapy has helped in the resolution of both infections. Hepatitis B vaccination should be recommended in susceptible patients waiting for liver transplantation.

  13. Design and performance of 10-Gb/s L-band REAM-SOA for OLT Transmitter in next generation access networks.

    PubMed

    Lee, Dong-Hun; Jeong, Jong Sool; Kim, Ki-Soo; Kim, Hyun-Soo; Kim, Dong Churl; Park, Mi-Ran; Han, Yong-Tak; Kwon, Oh Kee; Kwon, O-Kyun

    2015-02-09

    We present a 10-Gb/s L-band reflective electro-absorption modulator integrated with a semiconductor optical amplifier (REAM-SOA) having improved transmission performance at very low input power of seed light. To decrease the input power of seed light, the absorption characteristics of the REAM are adjusted to reduce the amplified spontaneous emission light returned into the SOA, suppressing the gain saturation effect of the SOA. At a considerably low input power of -16 dBm, the REAM-SOA exhibits a low transmission penalty of about 1.2 dB after 50-km SMF transmission. Over a wide input power range from -16 dBm to 5 dBm, a penalty of less than 1.6 dB is achieved at 50-km transmission.

  14. Hybrid scheduling mechanisms for Next-generation Passive Optical Networks based on network coding

    NASA Astrophysics Data System (ADS)

    Zhao, Jijun; Bai, Wei; Liu, Xin; Feng, Nan; Maier, Martin

    2014-10-01

    Network coding (NC) integrated into Passive Optical Networks (PONs) is regarded as a promising solution to achieve higher throughput and energy efficiency. To efficiently support multimedia traffic under this new transmission mode, novel NC-based hybrid scheduling mechanisms for Next-generation PONs (NG-PONs) including energy management, time slot management, resource allocation, and Quality-of-Service (QoS) scheduling are proposed in this paper. First, we design an energy-saving scheme that is based on Bidirectional Centric Scheduling (BCS) to reduce the energy consumption of both the Optical Line Terminal (OLT) and Optical Network Units (ONUs). Next, we propose an intra-ONU scheduling and an inter-ONU scheduling scheme, which takes NC into account to support service differentiation and QoS assurance. The presented simulation results show that BCS achieves higher energy efficiency under low traffic loads, clearly outperforming the alternative NC-based Upstream Centric Scheduling (UCS) scheme. Furthermore, BCS is shown to provide better QoS assurance.

  15. Experimental demonstration of the real-time online fault monitoring technique for chaos-based passive optical networks

    NASA Astrophysics Data System (ADS)

    Dou, Xinyu; Yin, Hongxi; Yue, Hehe; Jin, Yu; Shen, Jing; Li, Lin

    2015-09-01

    In this paper, a real-time online fault monitoring technique for chaos-based passive optical networks (PONs) is proposed and experimentally demonstrated. The fault monitoring is performed by the chaotic communication signal. The proof-of-concept experiments are demonstrated for two PON structures, i.e., wavelength-division-multiplexing (WDM) PON and Ethernet PON (EPON), respectively. For WDM PON, two monitoring approaches are investigated, one deploying a chaotic optical time domain reflectometry (OTDR) for each transmitter, and the other using only one tunable chaotic OTDR. The experimental results show that the faults at beyond 20 km from the OLT can be detected and located. The spatial resolution of the tunable chaotic OTDR is an order of magnitude of centimeter. Meanwhile, the monitoring process can operate in parallel with the chaotic optical secure communications. The proposed technique has benefits of real-time, online, precise fault location, and simple realization, which will significantly reduce the cost of operation, administration and maintenance (OAM) of PON.

  16. A cost-effective WDM-PON architecture simultaneously supporting wired, wireless and optical VPN services

    NASA Astrophysics Data System (ADS)

    Wu, Yanzhi; Ye, Tong; Zhang, Liang; Hu, Xiaofeng; Li, Xinwan; Su, Yikai

    2011-03-01

    It is believed that next-generation passive optical networks (PONs) are required to provide flexible and various services to users in a cost-effective way. To address this issue, for the first time, this paper proposes and demonstrates a novel wavelength-division-multiplexed PON (WDM-PON) architecture to simultaneously support three types of services: 1) wireless access traffic, 2) optical virtual passive network (VPN) communications, and 3) conventional wired services. In the optical line terminal (OLT), we use two cascaded Mach-Zehnder modulators (MZMs) on each wavelength channel to generate an optical carrier, and produce the wireless and the downstream traffic using the orthogonal modulation technique. In each optical network unit (ONU), the obtained optical carrier is modulated by a single MZM to provide the VPN and upstream communications. Consequently, the light sources in the ONUs are saved and the system cost is reduced. The feasibility of our proposal is experimentally and numerically verified.

  17. Using Fabry-Perot laser diode and reflective semiconductor optical amplifier for long reach WDM-PON system

    NASA Astrophysics Data System (ADS)

    Yeh, C. H.; Chow, C. W.; Wu, Y. F.; Shih, F. Y.; Chi, S.

    2011-10-01

    In this investigation, we propose and investigate the simple self-injection locked Fabry-Perot laser diodes (FP-LDs) in optical line terminal (OLT); and wavelength-tunable optical network unit (ONU) using reflective optical semiconductor amplifier (RSOA) and FP-LD laser for downstream and upstream traffic in long reach (LR) wavelength division multiplexed-passive optical network (WDM-PON) respectively. The output performance of the proposed two laser sources in terms of power and side-mode suppression ratio (SMSR) has been discussed. Here, for the downstream traffic, the proposed optical transmitter can be directly modulated at 2.5 Gb/s on-off keying (OOK) format with nearly 0.4 dB power penalty at bit error rate (BER) of 10 -9 through 75 km single-mode fiber (SMF) transmission. Moreover, the proposed upstream transmitter can be directly modulated at 1.25 and 2.5 Gb/s with nearly 0.5 and 1.1 dB power penalty, respectively, at the BER of 10 -9.

  18. Improving upstream transmission performance using a receiver with decision threshold level adjustment in a loopback WDM-PON

    NASA Astrophysics Data System (ADS)

    Cho, Seung-Hyun; Lee, Sang-Soo; Shin, Dong-Wook

    2010-06-01

    We have experimentally demonstrated that the use of an optical receiver with decision threshold level adjustment (DTLA) improved the performance of an upstream transmission in reflective semiconductor optical amplifier (RSOA)-based loopback wavelength division multiplexing-passive optical network (WDM-PON). Even though the extinction ratio (ER) of the downstream signal was as much as 9 dB and the injection power into the RSOA at the optical network unit was about -24 dBm, we successfully obtained error-free transmission results for the upstream signal through careful control of the decision threshold value in the optical receiver located at optical line terminal (OLT). Using an optical receiver with DTLA for upstream signal detection overcame significant obstacles related to the injection power into the RSOA and the ER of the downstream signal, which were previously considered limitations of the wavelength remodulation scheme. This technique is expected to provide flexibility for the optical link design in the practical deployment of a WDM-PON.

  19. Efficient eNB inter-communication scheme in converged mobile and NG-PON2 system

    NASA Astrophysics Data System (ADS)

    Xiao, Simiao; Sun, Xiao; Zhang, Kaibin

    2016-02-01

    In LTE, a new X2-interface is defined to facilitate direct communication between neighboring eNBs. Since LTE is an all-IP network, the X2-interface traffic currently needs to be routed and transponded in L3 at the edge router by IP addressing. As mobile data increases, it is a promising trend to backhaul mobile services based on PON. In this paper, an effective approach for eNB inter-communication over TWDM-PON is proposed. By associating the IP address of eNB and the MAC address of ONU, the "inter-eNB communication in L3" can be mapped into "inter-ONU communication in L2" and transponded via the protocol of PON at the OLT. Thus, fast and cost-effective eNB inter-communication can be realized based on TWDM-PON within one wavelength channel and between different wavelength channels. The increasing data traffic pressure to the core network can also be alleviated.

  20. WDM-PON access network with lightwave source centralized full-duplex link based on SSB-OOFDM for wired and 60 GHz band wireless alternative accesses

    NASA Astrophysics Data System (ADS)

    Ma, Jianxin; Wang, Zhao; Zheng, Guoli

    2014-04-01

    A novel lightwave centralized full-duplex WDM-PON access network based on single sideband optical orthogonal frequency-division multiplexing (SSB-OOFDM) is proposed for providing wired and 60-GHz band wireless accesses alternately. At the OLT, the multi-channels with 10-Gb/s 4-QAM-RF-OFDM signals are SSB modulated on the optical local oscillators (OLOs). At the RN, one OOFDM signal along with two OLOs is abstracted and switched to the corresponding HONU, where the signal can be downconverted to the 10-GHz or 60-GHz band RF-OFDM signal by one OLO for wired or wireless access, while the other one is used to bear the uplink signal. Since the HONU is free from the light sources, the system complexity and cost are reduced. Full duplex transmission over 25 km fiber have been demonstrated that the error vector magnitude (EVM) of the down- and up-link signals are much below the FEC limit for both the wired and 60-GHz band wireless access services.

  1. PAM4 based symmetrical 112-Gbps long-reach TWDM-PON

    NASA Astrophysics Data System (ADS)

    Wu, Liyu; Gao, Fan; Zhang, Minming; Fu, Songnian; Deng, Lei; Choi, Michael; Chang, Donald; Lei, Gordon K. P.; Liu, Deming

    2018-02-01

    We experimentally demonstrate cost effective symmetrical 112-Gbps long-reach passive optical network (LR-PON) over 70-km standard signal mode fiber (SSMF), based on pulse amplitude modulation (PAM)-4. Four 10G-class directly modulated lasers (DMLs) at C-band are used for achieving 4 × 28-Gbps downstream transmission, while two 18G-class DMLs at O-band are used to realize 2 × 56-Gbps upstream transmission, without any optical amplification in optical distributed network (ODN). Both dispersion compensation fiber (DCF) for downstream signal and praseodymium-doped fiber amplifier (PDFA) for upstream signal are equipped at optical line terminal (OLT). Meanwhile, sparse Volterra filter (SVF) equalizer is proposed to mitigate the transmission impairments with substantial reduction of computation complexity. Finally, we can successfully provide a loss budget of 33 dB per downstream wavelength channel, indicating of 64 optical network units (ONUs) with more than 1.25 Gbps per ONU.

  2. Revision of cemented hip arthroplasty using a hydroxyapatite-ceramic-coated femoral component.

    PubMed

    Raman, R; Kamath, R P; Parikh, A; Angus, P D

    2005-08-01

    We report the clinical and radiological outcome of 86 revisions of cemented hip arthroplasties using JRI-Furlong hydroxyapatite-ceramic-coated acetabular and femoral components. The acetabular component was revised in 62 hips and the femoral component in all hips. The mean follow-up was 12.6 years and no patient was lost to follow-up. The mean age of the patients was 71.2 years. The mean Harris hip and Oxford scores were 82 (59 to 96) and 23.4 (14 to 40), respectively. The mean Charnley modification of the Merle d'Aubigné and Postel score was 5 (3 to 6) for pain, 4.9 (3 to 6) for movement and 4.4 (3 to 6) for mobility. Migration of the acetabular component was seen in two hips and the mean acetabular inclination was 42.6 degrees. The mean linear polyethylene wear was 0.05 mm/year. The mean subsidence of the femoral component was 1.9 mm and stress shielding was seen in 23 (28%) with bony ingrowth in 76 (94%). Heterotopic ossification was seen in 12 hips (15%). There were three re-revisions, two for deep sepsis and one for recurrent dislocation and there were no re-revisions for aseptic loosening. The mean EuroQol EQ-5D description scores and health thermometer scores were 0.69 (0.51 to 0.89) and 79 (54 to 95), respectively. With an end-point of definite or probable loosening, the probability of survival at 12 years was 93.9% and 95.6% for the acetabular and femoral components, respectively. Overall survival at 12 years, with removal or further revision of either component for any reason as the end-point, was 92.3%. Our study supports the continued use of this arthroplasty and documents the durability of hydroxyapatite-ceramic-coated components.

  3. Robotic Rock Classification

    NASA Technical Reports Server (NTRS)

    Hebert, Martial

    1999-01-01

    This report describes a three-month research program undertook jointly by the Robotics Institute at Carnegie Mellon University and Ames Research Center as part of the Ames' Joint Research Initiative (JRI.) The work was conducted at the Ames Research Center by Mr. Liam Pedersen, a graduate student in the CMU Ph.D. program in Robotics under the supervision Dr. Ted Roush at the Space Science Division of the Ames Research Center from May 15 1999 to August 15, 1999. Dr. Martial Hebert is Mr. Pedersen's research adviser at CMU and is Principal Investigator of this Grant. The goal of this project is to investigate and implement methods suitable for a robotic rover to autonomously identify rocks and minerals in its vicinity, and to statistically characterize the local geological environment. Although primary sensors for these tasks are a reflection spectrometer and color camera, the goal is to create a framework under which data from multiple sensors, and multiple readings on the same object, can be combined in a principled manner. Furthermore, it is envisioned that knowledge of the local area, either a priori or gathered by the robot, will be used to improve classification accuracy. The key results obtained during this project are: The continuation of the development of a rock classifier; development of theoretical statistical methods; development of methods for evaluating and selecting sensors; and experimentation with data mining techniques on the Ames spectral library. The results of this work are being applied at CMU, in particular in the context of the Winter 99 Antarctica expedition in which the classification techniques will be used on the Nomad robot. Conversely, the software developed based on those techniques will continue to be made available to NASA Ames and the data collected from the Nomad experiments will also be made available.

  4. Agrometeorological drought in the Romanian plain within the sector delimited by the valleys of the Olt and Buzău Rivers.

    PubMed

    Murărescu, Ovidiu; Murătoreanu, George; Frînculeasa, Mădălina

    2014-01-01

    The last few decades have recorded a high frequency of the meteorological drought phenomenon. Southern and south-eastern Romania make no exception, with such phenomena often occurring from July to November 2011, which brought about an agrometerological drought that lasted from the third decade of July to early December, with a slight improvement in October. This situation led to a decrease in soil water reserves, mainly in the first 20 cm, with a negative impact on agricultural crops and the following agricultural year as well. The methodology was based on a correlative analysis between the decadal rainfall quantities and the existing soil water reserve, during the interval between June and November 2011, for eight weather stations. The statistico-mathematical data analysis showed an intensification of the pedological drought phenomenon in September, with a slight improvement in October and an increase in November.

  5. High output power of differently cut Nd:MgO:LiTaO3 CW lasers

    NASA Astrophysics Data System (ADS)

    Sun, D. H.; Liu, S. D.; Wang, D. Z.; Sang, Y. H.; Kang, X. L.; Liu, H.; Bi, Y.; Yan, B. X.; He, J. L.; Wang, J. Y.

    2013-04-01

    A high-quality Nd3+ and Mg2+ co-doped LiTaO3 (Nd:MgO:LT) crystal was grown by the Czochralski method. The polarized absorption spectra and fluorescence spectra were studied, and the absorption cross section was calculated by Judd-Ofelt (J-O) theory. The laser performance with different sample cuts of the crystal was investigated for the first time, and it was found that Nd:MgO:LT crystal with different cutting directions (a and c) exhibits different laser properties. By optimizing a partial reflectivity mirror in the laser experimental setting, a high continuous wave output power of 3.58 W was obtained at 1092 and 1076 nm with an optical-to-optical conversion efficiency of 22.78% and slope efficiency of 26.06%. The results indicate that Nd:MgO:LT crystal is a promising candidate for the manufacture of Nd3+ doped periodically poled MgO:LiTaO3 crystal (Nd:PPMgOLT), which should have considerable applications in self-frequency doubling and optical parametric oscillation laser devices.

  6. Energy-saving framework for passive optical networks with ONU sleep/doze mode.

    PubMed

    Van, Dung Pham; Valcarenghi, Luca; Dias, Maluge Pubuduni Imali; Kondepu, Koteswararao; Castoldi, Piero; Wong, Elaine

    2015-02-09

    This paper proposes an energy-saving passive optical network framework (ESPON) that aims to incorporate optical network unit (ONU) sleep/doze mode into dynamic bandwidth allocation (DBA) algorithms to reduce ONU energy consumption. In the ESPON, the optical line terminal (OLT) schedules both downstream (DS) and upstream (US) transmissions in the same slot in an online and dynamic fashion whereas the ONU enters sleep mode outside the slot. The ONU sleep time is maximized based on both DS and US traffic. Moreover, during the slot, the ONU might enter doze mode when only its transmitter is idle to further improve energy efficiency. The scheduling order of data transmission, control message exchange, sleep period, and doze period defines an energy-efficient scheme under the ESPON. Three schemes are designed and evaluated in an extensive FPGA-based evaluation. Results show that whilst all the schemes significantly save ONU energy for different evaluation scenarios, the scheduling order has great impact on their performance. In addition, the ESPON allows for a scheduling order that saves ONU energy independently of the network reach.

  7. Recent progress in InP/polymer-based devices for telecom and data center applications

    NASA Astrophysics Data System (ADS)

    Kleinert, Moritz; Zhang, Ziyang; de Felipe, David; Zawadzki, Crispin; Maese Novo, Alejandro; Brinker, Walter; Möhrle, Martin; Keil, Norbert

    2015-02-01

    Recent progress on polymer-based photonic devices and hybrid photonic integration technology using InP-based active components is presented. High performance thermo-optic components, including compact polymer variable optical attenuators and switches are powerful tools to regulate and control the light flow in the optical backbone. Polymer arrayed waveguide gratings integrated with InP laser and detector arrays function as low-cost optical line terminals (OLTs) in the WDM-PON network. External cavity tunable lasers combined with C/L band thinfilm filter, on-chip U-groove and 45° mirrors construct a compact, bi-directional and color-less optical network unit (ONU). A tunable laser integrated with VOAs, TFEs and two 90° hybrids builds the optical front-end of a colorless, dual-polarization coherent receiver. Multicore polymer waveguides and multi-step 45°mirrors are demonstrated as bridging devices between the spatialdivision- multiplexing transmission technology using multi-core fibers and the conventional PLCbased photonic platforms, appealing to the fast development of dense 3D photonic integration.

  8. Energy efficient flexible hybrid wavelength division multiplexing-time division multiplexing passive optical network with pay as you grow deployment

    NASA Astrophysics Data System (ADS)

    Garg, Amit Kumar; Madavi, Amresh Ashok; Janyani, Vijay

    2017-02-01

    A flexible hybrid wavelength division multiplexing-time division multiplexing passive optical network architecture that allows dual rate signals to be sent at 1 and 10 Gbps to each optical networking unit depending upon the traffic load is proposed. The proposed design allows dynamic wavelength allocation with pay-as-you-grow deployment capability. This architecture is capable of providing up to 40 Gbps of equal data rates to all optical distribution networks (ODNs) and up to 70 Gbps of a asymmetrical data rate to the specific ODN. The proposed design handles broadcasting capability with simultaneous point-to-point transmission, which further reduces energy consumption. In this architecture, each module sends a wavelength to each ODN, thus making the architecture fully flexible; this flexibility allows network providers to use only required OLT components and switch off others. The design is also reliable to any module or TRx failure and provides services without any service disruption. Dynamic wavelength allocation and pay-as-you-grow deployment support network extensibility and bandwidth scalability to handle future generation access networks.

  9. Early Spontaneous Graft Intra- and Perihepatic Hematoma after Liver Transplantation.

    PubMed

    Lupaşcu, Cristian; Apopei, Oana; Vlad, Nutu; Vasiluta, Ciprian; Trofin, Ana-Maria; Zabara, Mihai; Vornicu, Alexandra; Lupaşcu-Ursulescu, Corina; Nitu, Mioara; Crumpei, Felicia; Braşoveanu, Vladislav; Popescu, Irinel

    2017-01-01

    Hematoma of the graft is a life threatening complication of liver transplantation (LT) and there has been no overt conclusion in the literature about optimal management except in scarcely reported cases. It may be either intrahepatic or subcapsular, then again it may develop spontaneously or following parenchimal injuries or transhepatic percutaneous invasive manoeuvers. In this report we describe a rare case of large spontaneous graft intra- and perihepatic hematoma. A 62 year-old man underwent a whole graft orthotopic liver transplantation (OLT) for decompensated chronic liver disease due to alcoholic cirrhosis. The surgical procedure was uneventful. During the early postoperative course, routine Doppler ultrasound examination and CT-scan revealed an extrahepatic paracaval hematoma, 7 days after transplantation, which was stable and conservatively managed until the 18-th postoperative day, when rapidly expanding intraparenchimal hematoma involving the right hemiliver, several other perihepatic hematomas, significant right pleural effusion and hemorrhagic ascites were described. The patient was successfully treated conservatively (nonsurgically) with slow recovery of the liver allograft and discharged one month later in good general status. Celsius.

  10. Performance investigation of optical multicast overlay system using orthogonal modulation format

    NASA Astrophysics Data System (ADS)

    Singh, Simranjit; Singh, Sukhbir; Kaur, Ramandeep; Kaler, R. S.

    2015-03-01

    We proposed a bandwidth efficient wavelength division multiplexed-passive optical network (WDM-PON) to simultaneously transmit 60 Gb/s unicast and 10 Gb/s multicast services with 10 Gb/s upstream. The differential phase shift keying (DPSK) multicast signal is superimposed onto multiplexed non-return to zero/polarization shift keying (NRZ/PolSK) orthogonal modulated data signals. Upstream amplitude shift keying (ASK) signals formed without use of any additional light source and superimposed onto received unicast NRZ/PolSK signal before being transmitted back to optical line terminal (OLT). We also investigated the proposed WDM-PON system for variable optical input power, transmission distance of single mode fiber in multicast enable and disable mode. The measured Quality factor for all unicast and multicast signal is in acceptable range (>6). The original contribution of this paper is to propose a bandwidth efficient WDM-PON system that could be projected even in high speed scenario at reduced channel spacing and expected to be more technical viable due to use of optical orthogonal modulation formats.

  11. Optical beat interference noise reduction in OFDMA optical access link using self-homodyne balanced detection

    NASA Astrophysics Data System (ADS)

    Jung, Sang-Min; Won, Yong-Yuk; Han, Sang-Kook

    2013-12-01

    A Novel technique for reducing the OBI noise in optical OFDMA-PON uplink is presented. OFDMA is a multipleaccess/ multiplexing scheme that can provide multiplexing operation of user data streams onto the downlink sub-channels and uplink multiple access by means of dividing OFDM subcarriers as sub-channels. The main issue of high-speed, single-wavelength upstream OFDMA-PON arises from optical beating interference noise. Because the sub-channels are allocated dynamically to multiple access users over same nominal wavelength, it generates the optical beating interference among upstream signals. In this paper, we proposed a novel scheme using self-homodyne balanced detection in the optical line terminal (OLT) to reduce OBI noise which is generated in the uplink transmission of OFDMA-PON system. When multiple OFDMA sub-channels over the same nominal wavelength are received at the same time in the proposed architecture, OBI noises can be removed using balanced detection. Using discrete multitone modulation (DMT) to generate real valued OFDM signals, the proposed technique is verified through experimental demonstration.

  12. The transmission of symmetric 40 Gb/s TWDM-based NG-PON2 utilizing delay interferometer (DI) for RSOA bandwidth enhancement

    NASA Astrophysics Data System (ADS)

    Bindhaiq, Salem; Zulkifli, Nadiatulhuda; Supa'at, AbuSahmah M.

    2016-07-01

    Time and wavelength-division multiplexed passive optical network (TWDM-PON) has been finally selected as the pragmatic solution for the next-generation passive optical network stage 2 (NG-PON2). In this paper, we propose a symmetric 40 Gb/s TWDM-PON system with low cost reflective semiconductor optical amplifier (RSOA) for both downstream and upstream directions. A single bi-pass delay interferometer (DI), deployed in the optical line terminal (OLT), is used to enhance the poor performance of the RSOA with respect to the low bandwidth induced by laser chirp. With the help of the 40 GHz free spectrum range (FSR) DI, we show a successful transmission of the proposed work through simulation study where an aggregate capacity of 40 Gb/s is transported over 40 km transmission distance with 32 splits. The TWDM-PON system at BER of 10-6 has shown a minimum receiver sensitivity of -22.78 dBm and -22.71 dBm for both downstream and upstream, respectively with maximum power penalty of 2 dB for downstream channel and 2.39 dB for upstream channel.

  13. OSLG: A new granting scheme in WDM Ethernet passive optical networks

    NASA Astrophysics Data System (ADS)

    Razmkhah, Ali; Rahbar, Akbar Ghaffarpour

    2011-12-01

    Several granting schemes have been proposed to grant transmission window and dynamic bandwidth allocation (DBA) in passive optical networks (PON). Generally, granting schemes suffer from bandwidth wastage of granted windows. Here, we propose a new granting scheme for WDM Ethernet PONs, called optical network unit (ONU) Side Limited Granting (OSLG) that conserves upstream bandwidth, thus resulting in decreasing queuing delay and packet drop ratio. In OSLG instead of optical line terminal (OLT), each ONU determines its transmission window. Two OSLG algorithms are proposed in this paper: the OSLG_GA algorithm that determines the size of its transmission window in such a way that the bandwidth wastage problem is relieved, and the OSLG_SC algorithm that saves unused bandwidth for more bandwidth utilization later on. The OSLG can be used as granting scheme of any DBA to provide better performance in the terms of packet drop ratio and queuing delay. Our performance evaluations show the effectiveness of OSLG in reducing packet drop ratio and queuing delay under different DBA techniques.

  14. Consensus document. Management of non-alcoholic fatty liver disease (NAFLD). Clinical practice guideline.

    PubMed

    Aller, Rocío; Fernández-Rodríguez, Conrado; Lo Iacono, Oreste; Bañares, Rafael; Abad, Javier; Carrión, José Antonio; García-Monzón, Carmelo; Caballería, Joan; Berenguer, Marina; Rodríguez-Perálvarez, Manuel; Miranda, José López; Vilar-Gómez, Eduardo; Crespo, Javier; García-Cortés, Miren; Reig, María; Navarro, José María; Gallego, Rocío; Genescà, Joan; Arias-Loste, María Teresa; Pareja, María Jesús; Albillos, Agustín; Muntané, Jordi; Jorquera, Francisco; Solà, Elsa; Hernández-Guerra, Manuel; Rojo, Miguel Ángel; Salmerón, Javier; Caballería, Llorenc; Diago, Moisés; Molina, Esther; Bataller, Ramón; Romero-Gómez, Manuel

    2018-05-01

    Non-alcoholic fatty liver disease (NAFLD) is the main cause of liver diseases in Spain and the incidence is raising due to the outbreak of type 2 diabetes and obesity. This CPG suggests recommendation about diagnosis, mainly non-invasive biomarkers, and clinical management of this entity. Life-style modifications to achieve weight loss is the main target in the management of NAFLD. Low caloric Mediterranean diet and 200 minutes/week of aerobic exercise are encouraged. In non-responders patients with morbid obesity, bariatric surgery or metabolic endoscopy could be indicated. Pharmacological therapy is indicated in patients with NASH and fibrosis and non-responders to weight loss measures. NAFLD could influence liver transplantation, as a growing indication, the impact of steatosis in the graft viability, de novo NAFLD rate after OLT and a raised cardiovascular risk that modify the management of this entity. The current CPG was the result of the First Spanish NAFLD meeting in Seville. Copyright © 2018 Elsevier España, S.L.U. All rights reserved.

  15. Why should we pay more for layout designers?

    NASA Astrophysics Data System (ADS)

    Khan, Samee U.

    2003-12-01

    In this paper, we discuss the Passive Optical Network (PON) deployment on an arbitrary grid with guarenteed p-1 equipment failure. We show that this problem in general is NP-hard. We propose an algorithm, which guarantees a solution of 4-approximation to the optimal deployment, and further argue that this is the best lower bound achievable in our case.A basic architecture of PON is shown in figure 1.The main component of PON is an optical splitter device. Depending on which direction the light is travelling, it splits the incoming light and distributes it to multiple fibers towards Optical Network Termination (ONT), or combines it into one towards Optical Line Terminal (OLT). The PON technology uses a double-star architecture. The first star topology centers at the OLT, and the second at the optical splitter. PROBLEM DESCRIPTION: We can formulate the problem of optimal p-1 fault-tolerent PON Network Layout (PNL)as a graph theoretical problem. Consider a graph G(V,E), such that V represent the physical locations of the subscriber's, CO, and another location acquired by the CO to expand its network, and E represent the communication lines between two Vi's. If there is no direct communication line c(i,j) between Vi and Vj, we consider the shortest path between them measured in terms of simple distance or cost constraints. Without the loss of generality we assume that c(i,j)=c(j,i). For simplicity we do not further sub-divide V into the obvious categories that represent the locations of OLT, ONT, CO, optical splitters and the subscribers. We can now formulate the PNL problem as follows: "Given an undirected graph G, find the locations of ONTs and splitters such that the cost of the equipment is minimized and for QoS the maximum distance from an ONT to the pth splitter and from a splitter to the pth OLT is minimized". We assume that the OLT is residing inside the CO. The problem definition does not consider the optimization of ONT to the customer premises. This is due

  16. Source constraints on the genesis of Danubian granites in the South Carpathians Alpine Belt (Romania)

    NASA Astrophysics Data System (ADS)

    Duchesne, Jean-Clair; Laurent, Oscar; Gerdes, Axel; Bonin, Bernard; Liégeois, Jean-Paul; Tatu, Mihai; Berza, Tudor

    2017-12-01

    The pre-Alpine basement of the Lower Danubian nappes in the South Carpathians is made up of two Precambrian terranes (Drăgşan and Lainici-Păiuş) that were intruded by Pan-African/Cadomian and Variscan granitoid massifs. We focus on the major and trace element geochemistry (1) in the Drăgşan terrane, of the Variscan Retezat and Parâng intrusions; (2) in the Lainici-Păiuş terrane, of the Variscan Furcǎtura, Petreanu and Frumosu intrusions and of the Pan-African Vârful Pietrii, Şuşiţa and Olteţ granites and granitic leucosomes of migmatites; and (3) in the Upper Danubian nappes basement, of the Variscan Muntele Mic, Sfârdin, Cherbelezu and Ogradena intrusions. For each intrusion, in which a range of composition is observed, we decipher the differentiation mechanisms (fractional crystallization, hybridization, melt laden with restite minerals, etc.) in order to define the parental liquid compositions. The latter are calc-alkaline to alkali-calcic (except Olteţ that is calcic) and medium to high-K in composition. With [La/Yb]N > 10 and Sr/Y > 15, most melts display the so-called "continental adakite" affinities. The parental melt compositions are compared with experimental data to determine the melting conditions and the nature of the source rock. When the P-T conditions can be estimated, the temperatures range between 850 °C and 875 °C and the pressure between 5 and 15 kbar regardless of the ages of the granites and the terrane in which they have intruded. The source rock composition is dominated by a variety of mafic igneous compositions or metasediments rich in volcanic components. Clay-rich (pelitic) protoliths have not been identified. We confirm a Variscan age (c. 300 Ma) for the Frumosu intrusion granite and inherited Precambrian ages (c. 1.7-1.9 and 2.6-2.9 Ga) for the Motru dyke swarm. Thus, both Drăgşan and Lainici-Păiuş together with the Upper Danubian basement terranes were affected by Variscan post-collisional granitic plutonism. In

  17. Correlation of Multislice CT and Histomorphology in HCC Following TACE: Predictors of Outcome

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

    Herber, S., E-mail: herber@radiologie.klinik.uni-mainz.d; Biesterfeld, S.; Franz, U.

    2008-07-15

    The purpose of this study was to correlate histopathological with CT findings in patients suffering from hepatocellular carcinoma (HCC) eligible for orthotopic liver transplantation (OLT), with a special focus on the antitumoral effect of transarterial chemoembolization (TACE) therapy. A total of 42 consecutive patients suffering from HCC had been treated prior to OLT by means of TACE. TACE was carried out with a mixture of Lipiodol (10-20 ml) and mitomycin C (max. dosage, 10 mg). TACE was performed at 6- to 8-week intervals. Follow-up investigation included contrast-enhanced multislice CT controls and laboratory control. Liver explants were evaluated macroscopically and microscopicallymore » to determine the number and size of the tumor lesions as well as the degree of tumor necrosis. Necrosis was investigated in H and E-stained sections. The degree of necrosis was classified as follows: 0-25%, 26-50%, 51-75%, 75-99%, and complete necrosis. Two hundred thirty-one TACE procedures (5.5 {+-} 2.9; range, 1-14) were performed. Mean tumor size in CT before and after TACE was 4.1 {+-} 2.4 (range, 1.0-12.0 cm) and 2.7 {+-} 1.2 (range, 1.0-6.0 cm; p < 0.001). Mean tumor number before and after TACE in CT was 2.5 {+-} 1.5 (n = 105; range, 1-8) and 2.4 {+-} 2.0 (n = 103; range, 1-6; p = 0.99). In the surgical specimen tumor size and tumor number were 2.8 {+-} 1.6 (range, 1.0-7.0 cm; p = 0.78) and 1.9 {+-} 1.2 (range, 1-7; p = 0.003). Mean tumor necrosis was 67.8% {+-} 28.1%. Tumor necrosis was subtotal or complete in 17 of 42 (40.5%) patients. Tumor necrosis correlated significantly with the degree of arterial devascularization in CT (p = 0.001), the amount of Lipiodol washout (p = 0.002), and the number of tumor lesions (i.e., unifocal vs. multifocal). Furthermore, elevated serum levels of bilirubin (p = 0.005) and decreased albumin (p = 0.004) affected the local antitumoral effect. A poor necrosis rate (< 25%) significantly correlated with the number of TACE procedures

  18. The onset of the volcanism in the Ciomadul Volcanic Dome Complex (Eastern Carpathians): Eruption chronology and magma type variation

    NASA Astrophysics Data System (ADS)

    Molnár, Kata; Harangi, Szabolcs; Lukács, Réka; Dunkl, István; Schmitt, Axel K.; Kiss, Balázs; Garamhegyi, Tamás; Seghedi, Ioan

    2018-04-01

    Combined zircon U-Th-Pb and (U-Th)/He dating was applied to refine the eruption chronology of the last 2 Myr for the andesitic and dacitic Pilişca volcano and Ciomadul Volcanic Dome Complex (CVDC), the youngest volcanic area of the Carpathian-Pannonian region, located in the southernmost Harghita, eastern-central Europe. The proposed eruption ages, which are supported also by the youngest zircon crystallization ages, are much younger than the previously determined K/Ar ages. By dating every known eruption center in the CVDC, repose times between eruptive events were also accurately determined. Eruption of the andesite at Murgul Mare (1865 ± 87 ka) and dacite of the Pilişca volcanic complex (1640 ± 37 ka) terminated an earlier pulse of volcanic activity within the southernmost Harghita region, west of the Olt valley. This was followed by the onset of the volcanism in the CVDC, which occurred after several 100s kyr of eruptive quiescence. At ca. 1 Ma a significant change in the composition of erupted magma occurred from medium-K calc-alkaline compositions to high-K dacitic (Baba-Laposa dome at 942 ± 65 ka) and shoshonitic magmas (Malnaş and Bixad domes; 964 ± 46 ka and 907 ± 66 ka, respectively). Noteworthy, eruptions of magmas with distinct chemical compositions occurred within a restricted area, a few km from one another. These oldest lava domes of the CVDC form a NNE-SSW striking tectonic lineament along the Olt valley. Following a brief (ca. 100 kyr) hiatus, extrusion of high-K andesitic magma continued at Dealul Mare (842 ± 53 ka). After another ca. 200 kyr period of quiescence two high-K dacitic lava domes extruded (Puturosul: 642 ± 44 ka and Balvanyos: 583 ± 30 ka). The Turnul Apor lava extrusion occurred after a ca. 200 kyr repose time (at 344 ± 33 ka), whereas formation of the Haramul Mic lava dome (154 ± 16 ka) represents the onset of the development of the prominent Ciomadul volcano. The accurate determination of eruption dates shows that the

  19. Simplified flexible-PON upstream transmission using pulse position modulation at ONU and DSP-enabled soft-combining at OLT for adaptive link budgets.

    PubMed

    Liu, Xiang; Effenberger, Frank; Chand, Naresh

    2015-03-09

    We demonstrate a flexible modulation and detection scheme for upstream transmission in passive optical networks using pulse position modulation at optical network unit, facilitating burst-mode detection with automatic decision threshold tracking, and DSP-enabled soft-combining at optical line terminal. Adaptive receiver sensitivities of -33.1 dBm, -36.6 dBm and -38.3 dBm at a bit error ratio of 10(-4) are respectively achieved for 2.5 Gb/s, 1.25 Gb/s and 625 Mb/s after transmission over a 20-km standard single-mode fiber without any optical amplification.

  20. Glacial-interglacial dynamics of Antarctic firn columns: comparison between simulations and ice core air-δ15N measurements

    NASA Astrophysics Data System (ADS)

    Capron, E.; Landais, A.; Buiron, D.; Cauquoin, A.; Chappellaz, J.; Debret, M.; Jouzel, J.; Leuenberger, M.; Martinerie, P.; Masson-Delmotte, V.; Mulvaney, R.; Parrenin, F.; Prié, F.

    2012-12-01

    Correct estimate of the firn lock-in depth is essential for correctly linking gas and ice chronologies in ice cores studies. Here, two approaches to constrain the firn depth evolution in Antarctica are presented over the last deglaciation: output of a firn densification model and measurements of δ15N of N2 in air trapped in ice core. Since the firn densification process is largely governed by surface temperature and accumulation rate, we have investigated four ice cores drilled in coastal (Berkner Island, BI, and James Ross Island, JRI) and semi coastal (TALDICE and EPICA Dronning Maud Land, EDML) Antarctic regions. Combined with available δ15N measurements performed from the EPICA Dome C (EDC) site, the studied regions encompass a large range of surface accumulation rate and temperature conditions. While firn densification simulations are able to correctly represent most of the δ15N trends over the last deglaciation measured in the EDC, BI, TALDICE and EDML ice cores, they systematically fail to capture BI and EDML δ15N glacial levels, a mismatch previously seen for Central East Antarctic ice cores. Using empirical constraints of the EDML gas-ice depth offset during the Laschamp event (~ 41 ka), we can rule out the existence of a large convective zone as the explanation of the glacial firn model-δ15N data mismatch for this site. The good match between modelled and measured δ15N at TALDICE as well as the lack of any clear correlation between insoluble dust concentration in snow and δ15N records in the different ice cores suggest that past changes in loads of impurities are not the only main driver of glacial-interglacial changes in firn lock-in depth. We conclude that firn densification dynamics may instead be driven mostly by accumulation rate changes. The mismatch between modelled and measured δ15N may be due to inaccurate reconstruction of past accumulation rate or underestimated influence of accumulation rate in firnification models.

  1. A Hybrid OFDM-TDM Architecture with Decentralized Dynamic Bandwidth Allocation for PONs

    PubMed Central

    Cevik, Taner

    2013-01-01

    One of the major challenges of passive optical networks is to achieve a fair arbitration mechanism that will prevent possible collisions from occurring at the upstream channel when multiple users attempt to access the common fiber at the same time. Therefore, in this study we mainly focus on fair bandwidth allocation among users, and present a hybrid Orthogonal Frequency Division Multiplexed/Time Division Multiplexed architecture with a dynamic bandwidth allocation scheme that provides satisfying service qualities to the users depending on their varying bandwidth requirements. Unnecessary delays in centralized schemes occurring during bandwidth assignment stage are eliminated by utilizing a decentralized approach. Instead of sending bandwidth demands to the optical line terminal (OLT) which is the only competent authority, each optical network unit (ONU) runs the same bandwidth demand determination algorithm. ONUs inform each other via signaling channel about the status of their queues. This information is fed to the bandwidth determination algorithm which is run by each ONU in a distributed manner. Furthermore, Light Load Penalty, which is a phenomenon in optical communications, is mitigated by limiting the amount of bandwidth that an ONU can demand. PMID:24194684

  2. 128 Gb/s TWDM PON system using dispersion-supported transmission method

    NASA Astrophysics Data System (ADS)

    Bindhaiq, Salem; Zulkifli, Nadiatulhuda; Supa'at, Abusahmah M.; Idrus, Sevia M.; Salleh, M. S.

    2017-11-01

    Time and wavelength division multiplexed passive optical network (TWDM-PON) trend is considered as the most extraordinary trend of the next generation solution to accommodate exponential traffic growth for converged new services. In this paper, we briefly review recent progress on TWDM-PON system through the use of low cost directly modulated lasers (DMLs) transmission for various line rate transmissions to date. Furthermore, through simulation, we propose and evaluate a cost effective way to upgrade TWDM-PON up to a symmetric capacity of 128 Gb/s using fiber Bragg gratings (FBGs) in optical line terminal (OLT) as a paramount dispersion manager in high speed light-wave systems in both upstream and downstream directions. A low cost and potential chirpless directed modulated grating laser (DMGL) is employed for downstream link and DML with a single delay-interferometer (DI) is employed for upstream link. After illustrating the demonstrated system architecture and configuration, we present the results and analysis to prove the system feasibility. The results show that a successful transmission is achieved over 40 km single mode fiber with a power budget of 33.7 dB, which could support 1:256 splitting ratio.

  3. Burst mode PCS of EPON

    NASA Astrophysics Data System (ADS)

    Du, Xiao

    2005-02-01

    Normal GIGA ETHERNET continuously transmits or receives 8B/10B codes including data codes, idle codes or configuration information. In ETHERNET network, one computer links one port of switch through CAT5 and that is OK. But for EPON, it is different. All ONUs share one fiber in upstream, if we inherit the GIGA ETHERNET PHY, then collision will occur. All ONUs always transmit 8B/10B codes, and the optical signal will overlay. The OLT will receive the fault information. So we need a novel EPON PHY instead of ETHERNET PHY. But its major function is compatible with ETHERNET"s. In this article, first, the function of PCS sub layer is discussed and a novel PCS module is given that can be used in not only EPON system but also in GIGA ETHERNET system. The design of PCS is based on 1000BASE-X PCS technology. And the function of 1000BASE-X PCS should be accomplished first. Next we modify the design in order to meet the requirements of EPON system. In the new design, the auto negotiation and synchronization is the same to the 1000 BASE-X technology.

  4. A novel EPON architecture for supporting direct communication between ONUs

    NASA Astrophysics Data System (ADS)

    Wang, Liqian; Chen, Xue; Wang, Zhen

    2008-11-01

    In the traditional EPON network, optical signal from one ONU can not reach other ONUs. So ONUs can not directly transmit packets to other ONUs .The packets must be transferred by the OLT and it consumes both upstream bandwidth and downstream bandwidth. The bandwidth utilization is low and becomes lower when there are more packets among ONUs. When the EPON network carries P2P (Peer-to-Peer) applications and VPN applications, there would be a great lot of packets among ONUs and the traditional EPON network meets the problem of low bandwidth utilization. In the worst situation the bandwidth utilization of traditional EPON only is 50 percent. This paper proposed a novel EPON architecture and a novel medium access control protocol to realize direct packets transmission between ONUs. In the proposed EPON we adopt a novel circled architecture in the splitter. Due to the circled-splitter, optical signals from an ONU can reach the other ONUs and packets could be directly transmitted between two ONUs. The traffic between two ONUs only consumes upstream bandwidth and the bandwidth cost is reduced by 50 percent. Moreover, this kind of directly transmission reduces the packet's latency.

  5. Characterization of hepatocellular carcinoma (HCC) in non-alcoholic fatty liver disease (NAFLD) patients without cirrhosis.

    PubMed

    Mohamad, Bashar; Shah, Vaishal; Onyshchenko, Mykola; Elshamy, Mohammed; Aucejo, Federico; Lopez, Rocio; Hanouneh, Ibrahim A; Alhaddad, Razan; Alkhouri, Naim

    2016-07-01

    The incidence of hepatocellular carcinoma (HCC) has increased significantly in United States over the last few decades in parallel with the epidemic of nonalcoholic fatty liver disease (NAFLD). Limited data suggests that HCC could arise in steatotic liver without the presence of cirrhosis. The present study was conducted to characterize patients with NAFLD presenting with HCC in non-cirrhotic liver (NCL) compared to the NAFLD- HCC patients in association with cirrhotic liver (CL). A retrospective analysis of all patients diagnosed with HCC and NAFLD diagnosis seen at our institution between 2003 and 2012 was done. The patients were characterized based on demographic and clinical variables as well as histological and tumor features. Comparisons between the NCL and CL groups were done using analysis of variance (ANOVA) or the non-parametric Kruskal-Wallis tests and Pearson's chi-square tests or Fisher's Exact tests as appropriate. P value of <0.05 was considered statistically significant. Thirty-six patients with NAFLD and HCC in NCL (HCC-NCL group) were identified and compared to 47 patients with NAFLD-HCC and Liver Cirrhosis (HCC-LC group). Liver fibrosis was not present in 55.9 % of patients in the HCC-NCL group (F0), stage 1 was present in 17.6 %, stage 2 in 8.8 % and stage 3 in 17.6 %. Lobular inflammation was present in 63.6 % of non-cirrhotic patients. Patients in the HCC-NCL were older (67.5 ± 12.3 vs. 62.7 ± 8.1 years), and less likely to be obese (52 % vs. 83 %) or have type 2 diabetes (38 % vs. 83 %), with p value <0.05 for all. More importantly, compared with the HCC-CL group, those in the HCC-NCL group were more likely to present with a single nodule (80.6 % vs. 52.2 %), larger nodule size (>5 cm) (77.8 % vs. 10.6 %), and receive hepatic resection as the modality of HCC treatment (66.7 % vs. 17 %); and were less likely to receive loco-regional therapy (22.3 % vs. 61.7 %) or orthotopic liver transplantation (OLT) (0 % vs. 72.3 %), with p value <0

  6. Grant management procedure for energy saving TDM-PONs

    NASA Astrophysics Data System (ADS)

    Alaelddin, Fuad Yousif Mohammed; Newaz, S. H. Shah; AL-Hazemi, Fawaz; Choi, Jun Kyun

    2018-01-01

    In order to minimize energy consumption in Time Division Multiplexing-Passive Optical Network (TDM-PON), IEEE and ITU-T have mandated sleep mode mechanism for Optical Network Units (ONUs) in the latest TDM-PON standards (e.g. IEEE P1904.1 SIEPON, ITU-T G.sup45). The sleep mode mechanism is a promising mean for maximizing energy saving in an ONU. An ONU in sleep mode flips between sleep and active state depending on the presence or absent of upstream and downstream frames. To ensure Quality of Service (QoS) of upstream frames, the recent TDM-PON standards introduced an early wake-up mechanism, in which an ONU is forced to leave the sleep state on upstream frame arrival. When the Optical Line Terminal (OLT) of a TDM-PON allows early wake-up of its connected ONUs, it allocates gratuitous grants for the sleeping ONUs along with allocating upstream grants for the ONUs in active state. Note that, the gratuitous grants control message sent periodically by the OLT on Inter-Gratuitous grant Interval (IGI) time. After leaving sleep state due to the arrival of upstream frame, the ONU uses its allocated gratuitous grant to send a control message mentioning the amount of upstream bandwidth (upstream grant) required in order to forward the remaining frames in its buffer. However, the existing early wake-up process of ONU can lead to increase the energy consumption of an ONU. It is because of the ONU wakes-up immediately from the sleep state on arrival of the upstream frame, but even so, it needs to wait for forwarding the frame until its allocated gratuitous grant period, resulting in spending energy unnecessarily. In addition, current energy saving solution for TDM-PONs do not provide a clear solution on how to manage different types of grants (e.g. listening grant, upstream transmission grant) within a Dynamic Bandwidth Allocation (DBA) polling cycle. To address this problem, we propose a state-of-art Grant Management Procedure (GMP) in order to maximize energy saving in a TDM

  7. Alkaline phosphatase: the next independent predictor of the poor 90-day outcome in alcoholic hepatitis.

    PubMed

    Kasztelan-Szczerbinska, Beata; Slomka, Maria; Celinski, Krzysztof; Szczerbinski, Mariusz

    2013-01-01

    Determination of risk factors relevant to 90-day prognosis in AH. Comparison of the conventional prognostic models such as Maddrey's modified discriminant function (mDF) and Child-Pugh-Turcotte (CPT) score with newer ones: the Glasgow Alcoholic Hepatitis Score (GAHS); Age, Bilirubin, INR, Creatinine (ABIC) score, Model for End-Stage Liver Disease (MELD), and MELD-Na in the death prediction. The clinical and laboratory variables obtained at admission were assessed. The mDF, CPT, GAHS, ABIC, MELD, and MELD-Na scores' different areas under the curve (AUCs) and the best threshold values were compared. Logistic regression was used to assess predictors of the 90-day outcome. One hundred sixteen pts fulfilled the inclusion criteria. Twenty (17.4%) pts died and one underwent orthotopic liver transplantation (OLT) within 90 days of follow-up. No statistically significant differences in the models' performances were found. Multivariate logistic regression identified CPT score, alkaline phosphatase (AP) level higher than 1.5 times the upper limit of normal (ULN), and corticosteroids (CS) nonresponse as independent predictors of mortality. The CPT score, AP > 1.5 ULN, and the CS nonresponse had an independent impact on the 90-day survival in AH. Accuracy of all studied scoring systems was comparable.

  8. A New Training for Older Adults Using Combined Neuromuscular Electrical Stimulation and Volitional Contraction: A Pilot Study.

    PubMed

    Takano, Yoshio; Matsuse, Hiroo; Tsukada, Yuuya; Omoto, Masayuki; Hashida, Ryuki; Shiba, Naoto

    2016-01-01

    The hybrid training system (HTS) resists the motion of a volitionally contracting agonist muscle using force generated by its electrically stimulated antagonist. We have developed a new training method using the principle of HTS. This study was designed to evaluate the effect of HTS with electrical stimulation on muscle strength and physical function by comparing it against training without electrical stimulation in older adults. 16 subjects were randomly divided into two groups: the squat and single leg lift training (control, CTR) group, and the CTR with HTS training group. Some electrical stimulation was applied to the quadriceps and hamstring muscles in the HTS group. The subjects performed training for 25 min per session 3 times a week for 12 weeks. At points before and after the research maximal isokinetic torque, knee-flexors (KFT) and knee-extensors (KET), a one-leg standing test (OLT), a functional reach test (FRT), a 10-meter maximal gait time (10MGT) and Timed up & go test (TUG) were conducted. None of the subjects had any injuries during the study period. TUG significantly improved after the training period in both the HTS group (7.15 sec to 6.01 sec P = 0.01) and in the CTR.

  9. Orthotopic liver transplantation for portosystemic encephalopathy in an adult with congenital absence of the portal vein.

    PubMed

    Wojcicki, Maciej; Haagsma, Elizabeth B; Gouw, Annette S H; Slooff, Maarten J H; Porte, Robert J

    2004-09-01

    Congenital absence of the portal vein (CAPV) is a very rare venous malformation in which mesenteric venous blood drains directly into the systemic circulation. There is no portal perfusion of the liver and no portal hypertension. This abnormality is usually coincidentally discovered in children, the majority of whom have no signs of encephalopathy and only slightly abnormal liver function tests. Additional anomalies common in CAPV are cardiovascular abnormalities and hepatic tumors. To date, only 5 adult patients (>18 years) with CAPV have been described, none of whom underwent liver transplantation. We describe a 45-year-old man with CAPV and end-stage renal insufficiency due to focal segmental glomerulopathy, who developed therapy-resistant encephalopathy with intermittently high ammonia levels. The patient underwent a combined liver and kidney transplantation and is doing well at 2.5 years of follow-up. Histopathological examination of the native liver showed no portal vein branches in the portal tracts. In conclusion, our experience suggests that, although children with CAPV usually have no symptoms of encephalopathy, this may still develop at a later stage in adult life. When encephalopathy becomes refractory to medical therapy, orthotopic liver transplantation (OLT) can be successfully performed with restoration of normal cerebral function.

  10. Optical frequency comb generation with high tone-to-noise ratio for large-capacity wavelength division multiplexed passive optical network

    NASA Astrophysics Data System (ADS)

    Ullah, Rahat; Liu, Bo; Zhang, Qi; Tian, Qinghua; Tian, Feng; Qu, Zhaowei; Yan, Cheng; Khan, Muhammad Saad; Ahmad, Ibrar; Xin, Xiangjun

    2015-11-01

    We propose a technique for the generation of optical frequency comb from a single source, which reduces the costs of optical access networks. Two Mach-Zehnder modulators are cascaded with one phase modulator driven by radiofrequency signals. With 10-GHz frequency spacing, the generated 40 optical multicarriers have good tone-to-noise ratio with least excursions in their comb lines. The laser array at the optical line terminal of the conventional wavelength division multiplexed passive optical network (WDM-PON) system has been replaced with optical frequency comb generator (OFCG), which may result in cost-effective optical line terminal (OLT) supporting a large-capacity WDM-PON system. Of 40 carriers generated, each carrier carries 10 Gbps data based on differential phase-shift keying. Four hundred Gbps multiplexed data from all channels are successfully transmitted through a fiber span of 25 km with negligible power penalties. Part of the downlink signal is used in uplink transmission at optical network unit where intensity-modulated on-off keying is deployed for remodulation. Theoretical analysis of the proposed WDM-PON system based on OFCG are in good agreement with simulation results. The metrics considered for the analysis of the proposed OFCG in a WDM-PON system are power penalties of the full-duplex transmission, eye diagrams, and bit error rate.

  11. Electrical properties, phase transitions and conduction mechanisms of the [(C2H5)NH3]2CdCl4 compound

    NASA Astrophysics Data System (ADS)

    Mohamed, C. Ben; Karoui, K.; Saidi, S.; Guidara, K.; Rhaiem, A. Ben

    2014-10-01

    The [(C2H5)NH3]2CdCl4 hybrid material was prepared and its calorimetric study and electric properties were investigated at low temperature. The X-ray powder diffractogram has shown that the compound is crystallized in the orthorhombic system with Abma space group, and the refined unit cell parameters are a=7.546 Å, b=7.443 Å, and c=21.831 Å. The calorimetric study has revealed two endothermic peaks at 216 K and 357 K, which are confirmed by the variation of fp and σdc as a function of temperature. The equivalent circuit based on the Z-View-software was proposed and the conduction mechanisms were determined. The obtained results have been discussed in terms of the correlated barrier hopping model (CBH) in phase I (low temperature (OLT)), non-overlapping small polaron tunneling model (NSPT) in phase II (room temperature (ORT)) and the overlapping large polaron tunneling model in phase III (high temperature (OHT)). The density of localized states NF(E) at the Fermi level and the binding energy Wm were calculated. The variation of the dielectric loss log(εʺ) with log(ω) was found to follow the empirical law, ε″=B ωm(T).

  12. Dipeptidylpeptidase-IV, a key enzyme for the degradation of incretins and neuropeptides: activity and expression in the liver of lean and obese rats

    PubMed Central

    Tarantola, E.; Bertone, V.; Milanesi, G.; Capelli, E.; Ferrigno, A.; Neri, D.; Vairetti, M.; Barni, S.; Freitas, I.

    2012-01-01

    Given the scarcity of donors, moderately fatty livers (FLs) are currently being considered as possible grafts for orthotopic liver transplantation (OLT), notwithstanding their poor tolerance to conventional cold preservation. The behaviour of parenchymal and sinusoidal liver cells during transplantation is being studied worldwide. Much less attention has been paid to the biliary tree, although this is considered the Achille's heel even of normal liver transplantation. To evaluate the response of the biliary compartment of FLs to the various phases of OLT reliable markers are necessary. Previously we demonstrated that Alkaline Phosphatase was scarcely active in bile canaliculi of FLs and thus ruled it out as a marker. As an alternative, dipeptidylpeptidase-IV (DPP-IV), was investigated. This ecto-peptidase plays an important role in glucose metabolism, rapidly inactivating insulin secreting hormones (incretins) that are important regulators of glucose metabolism. DPP-IV inhibitors are indeed used to treat Type II diabetes. Neuropeptides regulating bile transport and composition are further important substrates of DPP-IV in the enterohepatic axis. DPP-IV activity was investigated with an azo-coupling method in the liver of fatty Zucker rats (fa/fa), using as controls lean Zucker (fa/+) and normal Wistar rats. Protein expression was studied by immunofluorescence with the monoclonal antibody (clone 5E8). In Wistar rat liver, DPP-IV activity and expression were high in the whole biliary tree, and moderate in sinusoid endothelial cells, in agreement with the literature. Main substrates of DPP-IV in hepatocytes and cholangiocytes could be incretins GLP-1 and GIP, and neuropeptides such as vasoactive intestinal peptide (VIP) and substance P, suggesting that these substances are inactivated or modified through the biliary route. In lean Zucker rat liver the enzyme reaction and protein expression patterns were similar to those of Wistar rat. In obese rat liver the patterns

  13. Dipeptidylpeptidase--IV, a key enzyme for the degradation of incretins and neuropeptides: activity and expression in the liver of lean and obese rats.

    PubMed

    Tarantola, E; Bertone, V; Milanesi, G; Capelli, E; Ferrigno, A; Neri, D; Vairetti, M; Barni, S; Freitas, I

    2012-10-08

    Given the scarcity of donors, moderately fatty livers (FLs) are currently being considered as possible grafts for orthotopic liver transplantation (OLT), notwithstanding their poor tolerance to conventional cold preservation. The behaviour of parenchymal and sinusoidal liver cells during transplantation is being studied worldwide. Much less attention has been paid to the biliary tree, although this is considered the Achille's heel even of normal liver transplantation. To evaluate the response of the biliary compartment of FLs to the various phases of OLT reliable markers are necessary. Previously we demonstrated that Alkaline Phosphatase was scarcely active in bile canaliculi of FLs and thus ruled it out as a marker. As an alternative, dipeptidylpeptidase-IV (DPP-IV), was investigated. This ecto-peptidase plays an important role in glucose metabolism, rapidly inactivating insulin secreting hormones (incretins) that are important regulators of glucose metabolism. DPP-IV inhibitors are indeed used to treat Type II diabetes. Neuropeptides regulating bile transport and composition are further important substrates of DPP-IV in the enterohepatic axis. DPP-IV activity was investigated with an azo-coupling method in the liver of fatty Zucker rats (fa/fa), using as controls lean Zucker (fa/+) and normal Wistar rats. Protein expression was studied by immunofluorescence with the monoclonal antibody (clone 5E8). In Wistar rat liver, DPP-IV activity and expression were high in the whole biliary tree, and moderate in sinusoid endothelial cells, in agreement with the literature. Main substrates of DPP-IV in hepatocytes and cholangiocytes could be incretins GLP-1 and GIP, and neuropeptides such as vasoactive intestinal peptide (VIP) and substance P, suggesting that these substances are inactivated or modified through the biliary route. In lean Zucker rat liver the enzyme reaction and protein expression patterns were similar to those of Wistar rat. In obese rat liver the patterns

  14. Link Power Budget and Traffict QoS Performance Analysis of Gygabit Passive Optical Network

    NASA Astrophysics Data System (ADS)

    Ubaidillah, A.; Alfita, R.; Toyyibah

    2018-01-01

    Data service of telecommunication network is needed widely in the world; therefore extra wide bandwidth must be provided. For this case, PT. Telekomunikasi Tbk. applies GPON (Gigabit Passive Optical Network) as optical fibre based on telecommunication network system. GPON is a point to a multipoint technology of FTTx (Fiber to The x) that transmits information signals to the subscriber over optical fibre. In GPON trunking system, from OLT (Optical Line Terminal), the network is split to many ONT (Optical Network Terminal) of the subscribers, so it causes path loss and attenuation. In this research, the GPON performance is measured from the link power budget system and the Quality of Service (QoS) of the traffic. And the observation result shows that the link power budget system of this GPON is in good condition. The link power budget values from the mathematical calculation and direct measurement are satisfy the ITU-T G984 Class B standard, that the power level must be between -8 dBm to -27 dBm. While from the traffic performance, the observation result shows that the network resource utility of the subscribers of the observed area is not optimum. The mean of subscriber utility rate is 27.985 bps for upstream and 79.687 bps for downstream. While maximally, It should be 60.800 bps for upstream and 486.400 bps for downstream.

  15. An adaptive two-stage energy-efficiency mechanism for the doze mode in EPON

    NASA Astrophysics Data System (ADS)

    Nikoukar, AliAkbar; Hwang, I.-Shyan; Su, Yu-Min; Liem, Andrew Tanny

    2016-07-01

    Sleep and doze power-saving modes are the common ways to reduce power consumption of optical network units (ONUs) in Ethernet passive optical network (EPON). The doze mode turns off the ONU transmitter when there is no traffic in the upstream direction while the sleep mode turns off the ONU transmitter and receiver. As the result, the sleep mode is more efficient compared to the doze mode, but it introduces additional complexity of scheduling and signaling, losses the clock synchronization and requires long clock recovery time; furthermore, it requires the cooperation of the optical line terminal (OLT) in the downstream direction to queue frames. To improve the energy-saving in the doze mode, a new two-stage mechanism is introduced that the doze sleep duration is extended for longer time with acceptable quality-of-services (QoS) metrics when ONU is idle in the current cycle. By this way the ONU enters the doze mode even in the high load traffic; moreover, the green dynamic bandwidth allocation (GBA) is proposed to calculate the doze sleep duration based on the ONU queue state and incoming traffic ratio. Simulation results show that the proposed mechanism significantly improves the energy-saving 74% and 54% when traffic load is from the light load to the high load in different traffic situations, and also promises the QoS performance.

  16. OTACT: ONU Turning with Adaptive Cycle Times in Long-Reach PONs

    NASA Astrophysics Data System (ADS)

    Zare, Sajjad; Ghaffarpour Rahbar, Akbar

    2015-01-01

    With the expansion of PON networks as Long-Reach PON (LR-PON) networks, the problem of degrading the efficiency of centralized bandwidth allocation algorithms threatens this network due to high propagation delay. This is because these algorithms are based on bandwidth negotiation messages frequently exchanged between the optical line terminal (OLT) in the Central Office and optical network units (ONUs) near the users, which become seriously delayed when the network is extended. To solve this problem, some decentralized algorithms are proposed based on bandwidth negotiation messages frequently exchanged between the Remote Node (RN)/Local Exchange (LX) and ONUs near the users. The network has a relatively high delay since there are relatively large distances between RN/LX and ONUs, and therefore, control messages should travel twice between ONUs and RN/LX in order to go from one ONU to another ONU. In this paper, we propose a novel framework, called ONU Turning with Adaptive Cycle Times (OTACT), that uses Power Line Communication (PLC) to connect two adjacent ONUs. Since there is a large population density in urban areas, ONUs are closer to each other. Thus, the efficiency of the proposed method is high. We investigate the performance of the proposed scheme in contrast with other decentralized schemes under the worst case conditions. Simulation results show that the average upstream packet delay can be decreased under the proposed scheme.

  17. Evolving experience with prevention and treatment of splenic artery syndrome after orthotopic liver transplantation.

    PubMed

    Mogl, Martina T; Nüssler, Natascha C; Presser, Sabine J; Podrabsky, Petr; Denecke, Timm; Grieser, Christian; Neuhaus, Peter; Guckelberger, Olaf

    2010-08-01

    Impaired hepatic arterial perfusion after orthotopic liver transplantation (OLT) may lead to ischemic biliary tract lesions and graft-loss. Hampered hepatic arterial blood flow is observed in patients with hypersplenism, often described as arterial steal syndrome (ASS). However, arterial and portal perfusions are directly linked via the hepatic arterial buffer response (HABR). Recently, the term 'splenic artery syndrome' (SAS) was coined to describe the effect of portal hyperperfusion leading to diminished hepatic arterial blood flow. We retrospectively analyzed 650 transplantations in 585 patients. According to preoperative imaging, 78 patients underwent prophylactic intraoperative ligation of the splenic artery. In case of postoperative SAS, coil-embolization of the splenic artery was performed. After exclusion of 14 2nd and 3rd retransplantations and 83 procedures with arterial interposition grafts, SAS was diagnosed in 28 of 553 transplantations (5.1%). Twenty-six patients were treated with coil-embolization, leading to improved liver function, but requiring postinterventional splenectomy in two patients. Additionally, two patients with SAS underwent splenectomy or retransplantation without preceding embolization. Prophylactic ligation could not prevent SAS entirely (n = 2), but resulted in a significantly lower rate of complications than postoperative coil-embolization. We recommend prophylactic ligation of the splenic artery for patients at risk of developing SAS. Post-transplant coil-embolization of the splenic artery corrected hemodynamic changes of SAS, but was associated with a significant morbidity.

  18. Dialysis-dependent acute kidney injury in children with end-stage liver disease: prevalence, dialysis modalities and outcome.

    PubMed

    Kreuzer, Martin; Gähler, Dagmar; Rakenius, Annette C; Prüfe, Jenny; Jack, Thomas; Pfister, Eva-Doreen; Pape, Lars

    2015-12-01

    Acute kidney injury (AKI) is a major complication in children with hepatic failure which leads to increased morbidity and mortality. The aim of this study was to provide paediatric data on the prevalence of dialysis-dependent AKI (dAKI), the feasibility and efficacy of dialysis methods and outcome. We conducted a retrospective analysis of 367 children listed for orthotopic liver transplantation (OLT) in our centre during the past decade. Data on 30 children (15 boys, 15 girls) were compiled for retrospective analysis, and data on dialysis feasibility and efficacy were available for 26 of these. Median age was 3.5 (range 0.4-17.7) years. Median MELD (Model For End-Stage Liver Disease) score was 33. dAKI was caused by hepato-renal syndrome in 16 of the 30 children. Twenty-one patients were treated with continuous veno-venous haemofiltration (CVVH), and nine patients received peritoneal dialysis (PD). Overall mortality was 77%. Mortality within the PD-group was 100 % versus 67% in the CVVH-group (p = 0.039). Urea reduction rate within the first 24 h of treatment was 12.9% in the PD group and 23.5% in the CVVH group (p = 0.019). Children with end-stage liver disease have a high risk for dAKI associated with high mortality. CVVH is associated with better efficacy and less mortality than PD.

  19. Incidence of DAA failure and the clinical impact of retreatment in real-life patients treated in the advanced stage of liver disease: Interim evaluations from the PITER network

    PubMed Central

    Gaeta, Giovanni Battista; Brunetto, Maurizia Rossana; Di Leo, Alfredo; Iannone, Andrea; Santantonio, Teresa Antonia; Giammario, Adele; Raimondo, Giovanni; Filomia, Roberto; Coppola, Carmine; Amoruso, Daniela Caterina; Blanc, Pierluigi; Del Pin, Barbara; Chemello, Liliana; Cavalletto, Luisa; Morisco, Filomena; Donnarumma, Laura; Rumi, Maria Grazia; Gasbarrini, Antonio; Siciliano, Massimo; Massari, Marco; Corsini, Romina; Coco, Barbara; Madonia, Salvatore; Cannizzaro, Marco; Zignego, Anna Linda; Monti, Monica; Russo, Francesco Paolo; Zanetto, Alberto; Persico, Marcello; Masarone, Mario; Villa, Erica; Bernabucci, Veronica; Taliani, Gloria; Biliotti, Elisa; Chessa, Luchino; Pasetto, Maria Cristina; Andreone, Pietro; Margotti, Marzia; Brancaccio, Giuseppina; Ieluzzi, Donatella; Borgia, Guglielmo; Zappulo, Emanuela; Calvaruso, Vincenza; Petta, Salvatore; Falzano, Loredana; Quaranta, Maria Giovanna; Weimer, Liliana Elena; Rosato, Stefano; Vella, Stefano; Giannini, Edoardo Giovanni

    2017-01-01

    worsened in 2 (2.8%) patients. Of patients who were retreated, 3 (4%) had undergone OLT before retreatment (all reached SVR12 following retreatment) and 2 (2.8%) underwent OLT after having achieved retreatment SVR12. Two (70%) of the 3 patients who failed to achieve SVR12 after retreatment, and 2 (2.8%) of the 69 patients who achieved retreatment SVR12 died from liver failure (Child-Pugh class deteriorated from B to C) or HCC complications. Conclusions Failure rate following the first DAA regimen in patients with advanced disease is similar to or lower than that reported in clinical trials, although the majority of patients were treated with suboptimal regimens. Interim findings showed that worsening of liver function after failure, in terms of Child Pugh class deterioration, was improved by successful retreatment in about one third of retreated patients within a short follow-up period; however, in some advanced liver disease patients, clinical outcomes (Child Pugh class, HCC development, liver failure and death) were independent of viral eradication. PMID:28977040

  20. Incidence of DAA failure and the clinical impact of retreatment in real-life patients treated in the advanced stage of liver disease: Interim evaluations from the PITER network.

    PubMed

    Kondili, Loreta A; Gaeta, Giovanni Battista; Brunetto, Maurizia Rossana; Di Leo, Alfredo; Iannone, Andrea; Santantonio, Teresa Antonia; Giammario, Adele; Raimondo, Giovanni; Filomia, Roberto; Coppola, Carmine; Amoruso, Daniela Caterina; Blanc, Pierluigi; Del Pin, Barbara; Chemello, Liliana; Cavalletto, Luisa; Morisco, Filomena; Donnarumma, Laura; Rumi, Maria Grazia; Gasbarrini, Antonio; Siciliano, Massimo; Massari, Marco; Corsini, Romina; Coco, Barbara; Madonia, Salvatore; Cannizzaro, Marco; Zignego, Anna Linda; Monti, Monica; Russo, Francesco Paolo; Zanetto, Alberto; Persico, Marcello; Masarone, Mario; Villa, Erica; Bernabucci, Veronica; Taliani, Gloria; Biliotti, Elisa; Chessa, Luchino; Pasetto, Maria Cristina; Andreone, Pietro; Margotti, Marzia; Brancaccio, Giuseppina; Ieluzzi, Donatella; Borgia, Guglielmo; Zappulo, Emanuela; Calvaruso, Vincenza; Petta, Salvatore; Falzano, Loredana; Quaranta, Maria Giovanna; Weimer, Liliana Elena; Rosato, Stefano; Vella, Stefano; Giannini, Edoardo Giovanni

    2017-01-01

    patients who were retreated, 3 (4%) had undergone OLT before retreatment (all reached SVR12 following retreatment) and 2 (2.8%) underwent OLT after having achieved retreatment SVR12. Two (70%) of the 3 patients who failed to achieve SVR12 after retreatment, and 2 (2.8%) of the 69 patients who achieved retreatment SVR12 died from liver failure (Child-Pugh class deteriorated from B to C) or HCC complications. Failure rate following the first DAA regimen in patients with advanced disease is similar to or lower than that reported in clinical trials, although the majority of patients were treated with suboptimal regimens. Interim findings showed that worsening of liver function after failure, in terms of Child Pugh class deterioration, was improved by successful retreatment in about one third of retreated patients within a short follow-up period; however, in some advanced liver disease patients, clinical outcomes (Child Pugh class, HCC development, liver failure and death) were independent of viral eradication.

  1. Non-Dipole Features of the Geomagnetic Field May Persist for Millions of Years

    NASA Astrophysics Data System (ADS)

    Biasi, J.; Kirschvink, J. L.

    2017-12-01

    Here we present paleointensity results from within the South Atlantic Anomaly (SAA), which is a large non-dipole feature of the geomagnetic field. Within the area of the SAA, anomalous declinations, inclinations, and intensities are observed. Our results suggest that the SAA has been present for at least 5 Ma. This is orders-of-magnitude greater than any previous estimate, and suggests that some non-dipole features do not `average out' over geologic time, which is a fundamental assumption in all paleodirectional studies. The SAA has been steadily growing in size since the first magnetic measurements were made in the South Atlantic, and it is widely believed to have appeared 400 years ago. Recent studies from South Africa (Tarduno et al. (2015)) and Tristan da Cunha (Shah et al. (2016)) have suggested that the SAA has persisted for 1 ka and 96 ka respectively. We conducted paleointensity (PI) experiments on basaltic lavas from James Ross Island, on the Antarctic Peninsula. This large shield volcano has been erupting regularly over the last 6+ Ma (dated via Ar/Ar geochronology), and therefore contains the most complete volcanostratigraphic record in the south Atlantic. Our PI experiments used the Thellier-Thellier method, the IZZI protocol, and the same selection criteria as the Lawrence et al. (2009) study of Ross Island lavas (near McMurdo Station), which is the only comparable PI study on the Antarctic continent. We determined an average paleointensity at JRI of 13.8±5.2 μT, which is far lower than what we would expect from a dipole field (55 μT). In addition, this is far lower than the current value over James Ross Island of 36 μT. These results support the following conclusions: The time-averaged field model of Juarez et al. (1998) and Tauxe et al. (2013) is strongly favored by our PI data. The SAA has persisted over James Ross Island for at least 5 Ma, and has not drifted significantly over that time. The strength of non-dipole features such as the SAA

  2. Novel toggle-rate based energy-efficient scheme for heavy load real-time IM-DD OFDM-PON with ONU LLID identification in time-domain using amplitude decision.

    PubMed

    Qin, Youxiang; Zhang, Junjie

    2017-07-10

    A novel low complexity and energy-efficient scheme by controlling the toggle-rate of ONU with time-domain amplitude identification is proposed for a heavy load downlink in an intensity-modulation and direct-detection orthogonal frequency division multiplexing passive optical network (IM-DD OFDM-PON). In a conventional OFDM-PON downlink, all ONUs have to perform demodulation for all the OFDM frames in a broadcast way no matter whether the frames are targeted to or not, which causes a huge energy waste. However, in our scheme, the optical network unit (ONU) logical link identifications (LLIDs) are inserted into each downlink OFDM frame in time-domain at the optical line terminal (OLT) side. At the ONU side, the LLID is obtained with a low complexity and high precision amplitude identification method. The ONU sets the toggle-rate of demodulation module to zero when the frames are not targeted to, which avoids unnecessary digital signal processing (DSP) energy consumption. Compared with the sleep-mode methods consisting of clock recovery and synchronization, toggle-rate shows its advantage in fast changing, which is more suitable for the heavy load scenarios. Moreover, for the first time to our knowledge, the characteristics of the proposed scheme are investigated in a real-time IM-DD OFDM system, which performs well at the received optical power as low as -21dBm. The experimental results show that 25.1% energy consumption can be saved in the receiver compared to the conventional configurations.

  3. All-optical VPN utilizing DSP-based digital orthogonal filters access for PONs

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoling; Zhang, Chongfu; Chen, Chen; Jin, Wei; Qiu, Kun

    2018-04-01

    Utilizing digital filtering-enabled signal multiplexing and de-multiplexing, a cost-effective all-optical virtual private network (VPN) system is proposed, for the first time to our best knowledge, in digital filter multiple access passive optical networks (DFMA-PONs). Based on the DFMA technology, the proposed system can be easily designed to meet the requirements of next generation network's flexibility, elasticity, adaptability and compatibility. Through dynamic digital filter allocation and recycling, the proposed all-optical VPN system can provide dynamic establishments and cancellations of multiple VPN communications with arbitrary traffic volumes. More importantly, due to the employment of DFMA technology, the system is not limited to a fixed signal format and different signal formats such as pulse amplitude modulation (PAM), quadrature amplitude modulation (QAM) and orthogonal frequency division multiplexing (OFDM) can be used. Moreover, one transceiver is sufficient to simultaneously transmit upstream (US)/VPN data to optical line terminal (OLT) or other VPN optical network units (ONUs), thus leading to great reduction in network constructions and operation expenditures. The proposed all-optical VPN system is demonstrated with the transceiver incorporating the formats of QAM and OFDM, which can be made transparent to downstream (DS), US and VPN communications. The bit error rates (BERs) of DS, US and VPN for OFDM signals are below the forward-error-correction (FEC) limit of 3 . 8 × 10-3 when the received optical powers are about -16.8 dBm, -14.5 dBm and -15.7 dBm, respectively.

  4. Geophysical evidence for non-uniform permafrost degradation after fire across boreal landscapes

    NASA Astrophysics Data System (ADS)

    Minsley, B. J.; Pastick, N. J.; Wylie, B. K.; Brown, D. N.; Kass, A.

    2015-12-01

    Fire can be a significant driver of permafrost change in boreal landscapes, altering the availability of soil carbon and nutrients that have important implications for future climate and ecological succession. However, not all landscapes are equally susceptible to fire-induced change. As fire frequency is expected to increase in the high latitudes, methods to understand the vulnerability and resilience of different landscapes to permafrost degradation are needed. We present a combination of multi-scale remote sensing, geophysical, and field observations that reveal details of both near-surface (<1 m) and deeper impacts of fire on permafrost. Along 11 transects that span burned-unburned boundaries in different landscape settings within interior Alaska, subsurface imaging indicates locations where permafrost appears to be resilient to disturbance from fire, areas where warm permafrost conditions exist that may be most vulnerable to future change, and also where permafrost has thawed. High-resolution geophysical data corroborate remote sensing interpretations of near-surface permafrost, and also add new high-fidelity details of spatial heterogeneity that extend from the shallow subsurface to depths of about 10 m. Data collected along each transect include observations of active layer thickness (ALT), organic layer thickness (OLT), plant species cover, electrical resistivity tomography (ERT), and downhole Nuclear Magnetic Resonance (NMR) measurements. Results show that post-fire impacts on permafrost can be variable, and depend on multiple factors such as fire severity, soil texture, and soil moisture.

  5. A prospective group sequential study evaluating a new type of fully covered self-expandable metal stent for the treatment of benign biliary strictures (with video).

    PubMed

    Poley, Jan-Werner; Cahen, Djuna L; Metselaar, Herold J; van Buuren, Henk R; Kazemier, Geert; van Eijck, Casper H J; Haringsma, Jelle; Kuipers, Ernst J; Bruno, Marco J

    2012-04-01

    Fully-covered self expandable metal stents (fcSEMSs) are an alternative to progressive plastic stenting for the treatment of benign biliary strictures (BBS) with the prospect of a higher treatment efficacy and the need for fewer ERCPs, thereby reducing the burden for patients and possibly costs. Key to this novel treatment is safe stent removal. To investigate the feasibility and safety of stent removal of a fcSEMS with a proximal retrieval lasso: a long wire thread integrated in the proximal ends of the wire mesh that hangs freely in the stent lumen. Pulling it enables gradual removal of the stent inside-out. A secondary aim was success of stricture resolution. Non-randomized, prospective follow-up study with 3 sequential cohorts of 8 patients with BBS. Academic tertiary referral center. Eligible patients had strictures either postsurgical (post-cholecystectomy (LCx) or liver transplantation (OLT)), due to chronic pancreatitis (CP), or papillary stenosis (PF). Strictures had to be located at least 2 cm below the liver hilum. All patients had one plastic stent in situ across the stricture and had not undergone previous treatment with either multiple plastic stents or fcSEMS. The first cohort of patients underwent stent placement for 2 months, followed by 3 months if the stricture had not resolved. The second and third cohort started with 3 months and 4 months, respectively, both followed by another 4 months if indicated. Treatment success was defined by stricture resolution at cholangiography, the ability to pass an inflated extraction balloon and clinical follow-up (at least 6 months). safety of stent removal. Secondary outcomes were complications and successful stricture resolution. A total of 23 patients (11 female; 20-67 yrs) were eligible for final analysis. One patient developed a malignant neuroendocrine tumor in the setting of CP. Strictures were caused by CP (13), OLT (6), LCx (3) and PF (1). In total 39 fcSEMS were placed and removed. Removals were easy

  6. Extended criteria donors in liver transplantation Part I: reviewing the impact of determining factors.

    PubMed

    Nemes, Balázs; Gámán, György; Polak, Wojciech G; Gelley, Fanni; Hara, Takanobu; Ono, Shinichiro; Baimakhanov, Zhassulan; Piros, Laszlo; Eguchi, Susumu

    2016-07-01

    The definition and factors of extended criteria donors have already been set; however, details of the various opinions still differ in many respects. In this review, we summarize the impact of these factors and their clinical relevance. Elderly livers must not be allocated for hepatitis C virus (HCV) positives, or patients with acute liver failure. In cases of markedly increased serum transaminases, donor hemodynamics is an essential consideration. A prolonged hypotension of the donor does not always lead to an increase in post-transplantation graft loss if post-OLT care is proper. Hypernatremia of less than 160 mEq/L is not an absolute contraindication to accept a liver graft per se. The presence of steatosis is an independent and determinant risk factor for the outcome. The gold standard of the diagnosis is the biopsy. This is recommended in all doubtful cases. The use of HCV+ grafts for HCV+ recipients is comparable in outcome. The leading risk factor for HCV recurrence is the actual RNA positivity of the donor. The presence of a proper anti-HBs level seems to protect from de novo HBV infection. A favourable outcome can be expected if a donation after cardiac death liver is transplanted in a favourable condition, meaning, a warm ischemia time < 30 minutes, cold ischemia time < 8-10 hours, and donor age 50-60 years. The pathway of organ quality assessment is to obtain the most relevant information (e.g. biopsy), consider the co-existing donor risk factors and the reserve capacity of the recipient, and avoid further technical issues.

  7. Vascular invasion is a prognostic indicator in hepatoblastoma.

    PubMed

    Shi, Yan; Commander, Sarah J; Masand, Prakash M; Heczey, Andras; Goss, John A; Vasudevan, Sanjeev A

    2017-06-01

    The data regarding vascular invasion as a prognostic factor in hepatoblastoma (HB) are conflicted. The purpose of this study is to examine the relationship between vascular invasion and outcomes. This is a retrospective review of patients <18 years old who underwent resection for hepatoblastoma from 1998 to 2015. Pathology reports were used to identify patients who had pathologic vascular invasion (VI), and those who did not (NVI). Sixty-six children were identified with a median age at diagnosis of 21months (interquartile range: 10-33months). Pathologic vascular invasion was present in 42/66 (64%) patients. A significant difference (P=0.02) in 3-year overall survival (3YOS) was detected between NVI (95%) and VI (61%). Recurrent disease was present in 8/66 (12%) patients. A marginally significant difference (P=0.08) was found in 3-year recurrence free survival (3YRFS) between NVI (94%) and the VI (76%) groups. Patients with NVI had no metastatic disease, had a lower recurrence rate, universally responded to neoadjuvant chemotherapy, and were less likely to have small cell undifferentiated histology. Twenty-one children underwent orthotopic liver transplant (OLT), with no difference in 3YROS or 3YRFS. Pathologic vascular invasion is associated with significantly worse 3YOS in HB, and lack of vascular invasion was associated with more favorable disease characteristics. The presence of pathologic vascular invasion did not confer a worse outcome in patients treated with liver transplantation in this cohort of patients. Retrospective review. Level III. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. The impact of a diphenyl diselenide-supplemented diet and aerobic exercise on memory of middle-aged rats.

    PubMed

    Cechella, José L; Leite, Marlon R; Gai, Rafaela M; Zeni, Gilson

    2014-08-01

    Selenium is an essential trace element for human health and has received attention for its role as a nutrient. The combination of exercise and nutrients has been proposed to promote health. The aim of this study was to determine the effects of a diet supplemented with diphenyl diselenide (PhSe)2 and swimming exercise on memory of middle-aged rats. Male Wistar rats (12months) received standard diet chow supplemented with 1ppm of (PhSe)2 for 4weeks. Rats were submitted to swimming training (20min per day for 4weeks). After 4weeks, memory was evaluated in the object recognition test (ORT) and in the object location test (OLT). The hippocampal levels of phosphorylated cAMP-response element-binding protein (CREB) were determined. The results of the present study demonstrated that the association of (PhSe)2-supplemented diet and swimming exercise improved short-term memory, long-term memory and spatial learning, and this effect was not related to the increase in hippocampal p-CREB levels in middle-age rats. This study also revealed that middle-aged rats in the swimming exercise group had the best performance in short- and long-term memory. In conclusion, we demonstrated that swimming exercise, (PhSe)2-supplemented diet or the association of these factors improved learning and memory functioning. The hippocampal levels of CREB were not directly related to the benefits of swimming exercise and (PhSe)2-supplemented diet association in memory of middle-aged rats. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Evaluation of effect of hybrid bioartificial liver using end-stage liver disease model

    PubMed Central

    Liu, Qing; Duan, Zhong-Ping; Huang, Chun; Zhao, Chun-Hui

    2004-01-01

    AIM: To study the role of hybrid bioartificial liver (HBL) in clearing proinflammatory cytokines and endotoxin in patients with acute and sub-acute liver failure and the effects of HBL on systemic inflammatory syndrome (SIRS) and multiple organ dysfunction syndrome (MODS). METHODS: Five cases with severe liver failure (3 acute and 2 subacute) were treated with HBL. The clinical signs and symptoms, total bilirubin (TBIL), serum ammonia, endotoxin TNF-α, IL-6 and prothrombin activity (PTA), cholinesterase (CHE) were recorded before, during and after treatment. The end-stage liver disease (MELD) was used for the study. RESULTS: Two patients were bridged for spontaneous recovery and 1 patient was bridged for OLT successfully. Another 2 patients died on d 8 and d 21. The spontaneous recovery rate was 30.0%. PTA and CHE in all patients were significantly increased (P < 0.01), while the serum TBIL, endotoxin,TNF-α, IL-6 were decreased. MELD score (mean 43.6) predicted 100% deaths within 3 mo before treatment with HBL. After treatment with HBL, four out of 5 patients had decreased MELD scores (mean 36.6). The MELD score predicted 66% mortalities. CONCLUSION: The proinflammatory cytokines (TNFα, IL-6 and endotoxin)can be significantly removed by hybrid bioartificial liver and HBL appears to be effective in blocking SIRS and MODS in patients with acute and sub-acute liver failure. MELD is a reliable measure for predicting short-term mortality risk in patients with end-stage liver disease. The prognostic result also corresponds to clinical outcome. PMID:15112365

  10. Qatar-1: indications for possible transit timing variations

    NASA Astrophysics Data System (ADS)

    von Essen, C.; Schröter, S.; Agol, E.; Schmitt, J. H. M. M.

    2013-07-01

    Aims: Variations in the timing of transiting exoplanets provide a powerful tool for detecting additional planets in the system. Thus, the aim of this paper is to discuss the plausibility of transit timing variations (TTVs) on the Qatar-1 system by means of primary transit light curves analysis. Furthermore, we provide an interpretation of the timing variation. Methods: We observed Qatar-1 between March 2011 and October 2012 using the 1.2 m OLT telescope in Germany and the 0.6 m PTST telescope in Spain. We present 26 primary transits of the hot Jupiter Qatar-1b. In total, our light curves cover a baseline of 18 months. Results: We report on indications for possible long-term TTVs. Assuming that these TTVs are true, we present two different scenarios that could explain them. Our reported ~190 days TTV signal can be reproduced by either a weak perturber in resonance with Qatar-1b, or by a massive body in the brown dwarf regime. More observations and radial velocity monitoring are required to better constrain the perturber's characteristics. We also refine the ephemeris of Qatar-1b, which we find to be T0 = 2456157.42204 ± 0.0001 BJDTDB and P = 1.4200246 ± 0.0000007 days, and improve the system orbital parameters. Tables of the transit observations are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/555/A92

  11. Genetic expression programming-based DBA for enhancing peer-assisted music-on-demand service in EPON

    NASA Astrophysics Data System (ADS)

    Liem, Andrew Tanny; Hwang, I.-Shyan; Nikoukar, AliAkbar; Lee, Jhong-Yue

    2015-03-01

    Today, the popularity of peer-assisted music-on-demand (MoD) has increased significantly worldwide. This service allows users to access large music library tracks, listen to music, and share their playlist with other users. Unlike the conventional voice traffic, such an application maintains music quality that ranges from 160 kbps to 320 kbps, which most likely consumes more bandwidth than other traffics. In the access network, Ethernet passive optical network (EPON) is one of the best candidates for delivering such a service because of being cost-effective and with high bandwidth. To maintain music quality, a stutter needs to be prevented because of either network effects or when the due user was not receiving enough resources to play in a timely manner. Therefore, in this paper, we propose two genetic expression programming (GEP)-based dynamic bandwidth allocations (DBAs). The first DBA is a generic DBA that aims to find an optimum formula for voice, video, and data services. The second DBA aims to find optimum formulas so that Optical Line Terminal (OLT) can satisfy not only the voice and Peer-to-Peer (P2P) MoD traffics but also reduce the stutter. Optical Network Unit (ONU) traits such as REPORT and GATE messages, cycle time, and mean packet delay are set to be predictor variables. Simulation results show that our proposed DBAs can satisfy the voice and P2P MoD services packet delay and monitor other overall system performances such as expedited forwarding (EF) jitter, packet loss, bandwidth waste, and system throughputs.

  12. Improved amino acid, bioenergetic metabolite and neurotransmitter profiles following human amnion epithelial cell transplant in intermediate maple syrup urine disease mice.

    PubMed

    Skvorak, Kristen J; Dorko, Kenneth; Marongiu, Fabio; Tahan, Veysel; Hansel, Marc C; Gramignoli, Roberto; Arning, Erland; Bottiglieri, Teodoro; Gibson, K Michael; Strom, Stephen C

    2013-06-01

    Orthotopic liver transplant (OLT) significantly improves patient outcomes in maple syrup urine disease (MSUD; OMIM: 248600), yet organ shortages point to the need for alternative therapies. Hepatocyte transplantation has shown both clinical and preclinical efficacy as an intervention for metabolic liver diseases, yet the availability of suitable livers for hepatocyte isolation is also limited. Conversely, human amnion epithelial cells (hAEC) may have utility as a hepatocyte substitute, and they share many of the characteristics of pluripotent embryonic stem cells while lacking their safety and ethical concerns. We reported that like hepatocytes, transplantation of hAEC significantly improved survival and lifespan, normalized body weight, and significantly improved branched-chain amino acid (BCAA) levels in sera and brain in a transgenic murine model of intermediate maple syrup urine disease (imsud). In the current report, we detail the neural and peripheral metabolic improvements associated with hAEC transplant in imsud mice, including amino acids associated with bioenergetics, the urea cycle, as well as the neurotransmitter systems for serotonin, dopamine, and gamma-aminobutyric acid (GABA). This stem cell therapy results in significant global correction of the metabolic profile that characterizes the disease, both in the periphery and the central nervous system, the target organ for toxicity in iMSUD. The significant correction of the disease phenotype, coupled with the theoretical benefits of hAEC, particularly their lack of immunogenicity and tumorigenicity, suggests that human amnion epithelial cells deserve serious consideration for clinical application to treat metabolic liver diseases. Copyright © 2013. Published by Elsevier Inc.

  13. Primary Budd-Chiari syndrome - a single center experience.

    PubMed

    Raszeja-Wyszomirska, Joanna; Mieżyńska-Kurtycz, Joanna; Marlicz, Wojciech; Lawniczak, Małgorzata; Wójcicki, Maciej

    2012-09-01

    Budd-Chiari syndrome (BCS) is recognized as a clinical manifestation of various prothrombotic conditions which may be lethal within 3 years of the onset of symptoms if untreated. This study is a retrospective analysis of patients with BCS managed between 2004 and 2011. The diagnosis was confirmed with contrast CT-angiography and/or Doppler ultrasound. BCS was diagnosed in 20 patients (11 females and 9 males), median age 38 years (ranging from 18 to 56). Twelve patients were referred as acute BCS for the liver transplant (LTx) assessment. Thrombosis of the hepatic veins was caused by myeloproliferative disorders (n=8), end-stage liver disease (n=4), protein C deficiency (n=3), paroxysmal nocturnal hemoglobinuria (PNH) (n=1), antiphospholipid syndrome (n=1) and secondary poliglobulia (n=1). In two patients the origin of BCS could not be established despite appropriate screening. Median follow-up was 29 months. Low molecular heparin with subsequent conversion to vitamin K antagonists was routinely applied in all patients. Two patients underwent TIPS procedure with good long term outcome and 10 subjects received LTx; 1 patient was lost to follow-up and 1 died of chest infection 9 years since the diagnosis of BCS was made; 14 patients, including those who received LTx, were alive and well at least one year after BCS diagnosis. All survivors remain stable and are followed-up on a regular basis. Strict adherence to the diagnostic and therapeutic guidelines plays a crucial role in the management of BCS patients. Our results confirm the efficacy of anticoagulation as well as TIPS and/or OLT in treatment of this rare condition.

  14. Revisiting the role of pathological analysis in transarterial chemoembolization-treated hepatocellular carcinoma after transplantation

    PubMed Central

    Vasuri, Francesco; Malvi, Deborah; Rosini, Francesca; Baldin, Pamela; Fiorentino, Michelangelo; Paccapelo, Alexandro; Ercolani, Giorgio; Pinna, Antonio Daniele; Golfieri, Rita; Morselli-Labate, Antonio Maria; Grigioni, Walter Franco; D’Errico-Grigioni, Antonia

    2014-01-01

    AIM: To define the histopathological features predictive of post-transplant hepatocellular carcinoma (HCC) recurrence after transarterial chemoembolization, applicable for recipient risk stratification. METHODS: We retrospectively reviewed the specimens of all suspicious nodules (total 275) from 101 consecutive liver transplant recipients which came to our Pathology Unit over a 6-year period. All nodules were sampled and analyzed, and follow-up data were collected. We finally considered 11 histological variables for each patient: total number of nodules, number of viable nodules, size of the major nodule, size of the major viable nodule, occurrence of microscopic vascular invasion, maximum Edmondson's grade, clear cell/sarcomatous changes, and the residual neoplastic volume. Survival data were computed by means of the Kaplan-Meier procedure and analyzed by means of the Cox proportional hazards model. The multivariate linear regression and a k-means cluster analysis were also used in order to compute the standardized histological score. RESULTS: The total number of nodules, the residual neoplastic volume (the total volume of all evaluated nodules minus the necrotic portion) and the microvascular invasion entered the Cox multivariate hazard model with HCC recurrence as dependent variable. The histological score was therefore computed and a cluster analysis sorted recipients into 3 risk groups, with 3.3%, 18.5% and 53.8% respectively of tumor recurrence rates and 1.6%, 11.1% and 38.5% of tumor-related mortality respectively at the end of follow-up. CONCLUSION: The histological score allows a reliable stratification of HCC recurrence risk, especially in those recipients found out to be beyond the Milan criteria after orthotopic liver transplantation (OLT). PMID:25309084

  15. Liver transplantation in Greek children: 15 years experience

    PubMed Central

    Xinias, Ioannis; Mavroudi, Antigoni; Vrani, Olga; Imvrios, Georgios; Takoudas, Dimitrios; Spiroglou, Kleomenis

    2010-01-01

    Liver transplantation (LT) is the only available live-saving procedure for children with irreversible liver failure. This paper reports our experience from the follow-up of 16 Greek children with end-stage liver failure who underwent a LT. Over a period of 15 years, 16 pediatric liver recipients received follow up after being subjected to OLT (orthotopic liver transplantation) due to end-stage liver failure. Nine children initially presented with extrahepatic biliary atresia, 2 with acute liver failure after toxic mushroom ingestion, 2 with intrahepatic cholestasis, 2 with metabolic diseases and one with hepatoblastoma. Ten children received a liver transplant in the Organ Transplantation Unit of Aristotle University of Thessaloniki and the rest in other transplant centers. Three transplants came from a living-related donor and 13 from a deceased donor. Six children underwent immunosuppressive treatment with cyclosporine, mycophenolate mofetil and corticosteroids, and 7 with tacrolimus, mycophenolate mofetil and corticosteroids. Three out of 16 children died within the first month after the transplantation due to post-transplant complications. Three children presented with acute rejection and one with chronic organ rejection which was successfully managed. Five children presented with cytomegalovirus infection, 5 with Epstein-Barr virus, 2 with HSV1,2, 2 with ParvoB19 virus, 2 with varicella-zoster virus and one with C. Albicans infection. One child presented with upper gastrointestinal hemorrhage and one with small biliary paucity. A satisfying outcome was achieved in most cases, with good graft function, except for the patient with small biliary paucity who required re-transplantation. The long-term clinical course of liver transplanted children is good under the condition that they are attended in specialized centers. PMID:21589827

  16. Outcomes of Locoregional Tumor Therapy for Patients with Hepatocellular Carcinoma and Transjugular Intrahepatic Portosystemic Shunts

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

    Padia, Siddharth A., E-mail: spadia@uw.edu; Chewning, Rush H., E-mail: rchewnin@uw.edu; Kogut, Matthew J., E-mail: kogutm@uw.edu

    PurposeLocoregional therapy for hepatocellular carcinoma (HCC) can be challenging in patients with a transjugular intrahepatic portosystemic shunt (TIPS). This study compares safety and imaging response of ablation, chemoembolization, radioembolization, and supportive care in patients with both TIPS and HCC.MethodsThis retrospective study included 48 patients who had both a TIPS and a diagnosis of HCC. Twenty-nine of 48 (60 %) underwent treatment for HCC, and 19/48 (40 %) received best supportive care (i.e., symptomatic management only). While etiology of cirrhosis and indication for TIPS were similar between the two groups, treated patients had better baseline liver function (34 vs. 67 % Child-Pugh class C).more » Tumor characteristics were similar between the two groups. A total of 39 ablations, 17 chemoembolizations, and 10 yttrium-90 radioembolizations were performed on 29 patients.ResultsAblation procedures resulted in low rates of hepatotoxicity and clinical toxicity. Post-embolization/ablation syndrome occurred more frequently in patients undergoing chemoembolization than ablation (47 vs. 15 %). Significant hepatic dysfunction occurred more frequently in the chemoembolization group than the ablation group. Follow-up imaging response showed objective response in 100 % of ablation procedures, 67 % of radioembolization procedures, and 50 % of chemoembolization procedures (p = 0.001). When censored for OLT, patients undergoing treatment survived longer than patients receiving supportive care (2273 v. 439 days, p = 0.001).ConclusionsAblation appears to be safe and efficacious for HCC in patients with TIPS. Catheter-based approaches are associated with potential increased toxicity in this patient population. Chemoembolization appears to be associated with increased toxicity compared to radioembolization.« less

  17. Symmetric 40-Gb/s TWDM-PON with 51-dB loss budget by using a single SOA as preamplifier, booster and format converter in ONU.

    PubMed

    Li, Zhengxuan; Yi, Lilin; Hu, Weisheng

    2014-10-06

    In this paper, we propose to use a semiconductor optical amplifier (SOA) in the optical network unit (ONU) to improve the loss budget in time and wavelength division multiplexed-passive optical network (TWDM-PON) systems. The SOA boosts the upstream signal to increase the output power of the electro-absorption modulated laser (EML) and simultaneously pre-amplifies the downstream signal for sensitivity improvement. The penalty caused by cross gain modulation (XGM) effect is negligible due to the low extinction ratio (ER) of upstream signal and the large wavelength difference between upstream and downstream links. In order to achieve a higher output power, the SOA is driven into its saturation region, where the self-phase modulation (SPM) effect converts the intensity into phase information and realizes on-off-keying (OOK) to phase-shifted-keying (PSK) format conversion. In this way, the pattern effect is eliminated, which releases the requirement of gain-clamping on SOA. To further improve the loss budget of upstream link, an Erbium doped fiber amplifier (EDFA) is used in the optical line terminal (OLT) to pre-amplify the received signal. For the downstream direction, directly modulated laser (DML) is used as the laser source. Taking advantage of its carrier-less characteristic, directly modulated signal shows high tolerance to fiber nonlinearity, which could support a downstream launch power as high as + 16 dBm per channel. In addition, the signal is pre-amplified by the SOA in ONU before being detected, so the sensitivity limitation for downstream link is also removed. As a result, a truly passive symmetric 40-Gb/s TWDM-PON was demonstrated, achieving a link loss budget of 51 dB.

  18. Object location and object recognition memory impairments, motivation deficits and depression in a model of Gulf War illness.

    PubMed

    Hattiangady, Bharathi; Mishra, Vikas; Kodali, Maheedhar; Shuai, Bing; Rao, Xiolan; Shetty, Ashok K

    2014-01-01

    Memory and mood deficits are the enduring brain-related symptoms in Gulf War illness (GWI). Both animal model and epidemiological investigations have indicated that these impairments in a majority of GW veterans are linked to exposures to chemicals such as pyridostigmine bromide (PB, an antinerve gas drug), permethrin (PM, an insecticide) and DEET (a mosquito repellant) encountered during the Persian Gulf War-1. Our previous study in a rat model has shown that combined exposures to low doses of GWI-related (GWIR) chemicals PB, PM, and DEET with or without 5-min of restraint stress (a mild stress paradigm) causes hippocampus-dependent spatial memory dysfunction in a water maze test (WMT) and increased depressive-like behavior in a forced swim test (FST). In this study, using a larger cohort of rats exposed to GWIR-chemicals and stress, we investigated whether the memory deficiency identified earlier in a WMT is reproducible with an alternative and stress free hippocampus-dependent memory test such as the object location test (OLT). We also ascertained the possible co-existence of hippocampus-independent memory dysfunction using a novel object recognition test (NORT), and alterations in mood function with additional tests for motivation and depression. Our results provide new evidence that exposure to low doses of GWIR-chemicals and mild stress for 4 weeks causes deficits in hippocampus-dependent object location memory and perirhinal cortex-dependent novel object recognition memory. An open field test performed prior to other behavioral analyses revealed that memory impairments were not associated with increased anxiety or deficits in general motor ability. However, behavioral tests for mood function such as a voluntary physical exercise paradigm and a novelty suppressed feeding test (NSFT) demonstrated decreased motivation levels and depression. Thus, exposure to GWIR-chemicals and stress causes both hippocampus-dependent and hippocampus-independent memory

  19. Performance analysis of TCP traffic and its influence on ONU's energy saving in energy efficient TDM-PON

    NASA Astrophysics Data System (ADS)

    Alaelddin, Fuad Yousif Mohammed; Newaz, S. H. Shah; Lee, Joohyung; Uddin, Mohammad Rakib; Lee, Gyu Myoung; Choi, Jun Kyun

    2015-12-01

    The majority of the traffic over the Internet is TCP based, which is very sensitive to packet loss and delay. Existing research efforts in TDM-Passive Optical Networks (TDM-PONs) mostly evaluate energy saving and traffic delay performances under different energy saving solutions. However, to the best of our knowledge, how energy saving mechanisms could affect TCP traffic performance in TDM-PONs has hardly been studied. In this paper, by means of our state-of-art OPNET Modular based TDM-PON simulator, we evaluate TCP traffic delay, throughput, and Optical Network Unit (ONU) energy consumption performances in a TDM-PON where energy saving mechanisms are employed in ONUs. Here, we study the performances under commonly used energy saving mechanisms defined in standards for TDM-PONs: cyclic sleep and doze mode. In cyclic sleep mode, we evaluate the performances under two well-known sleep interval length deciding algorithms (i.e. fixed sleep interval (FSI) and exponential sleep interval deciding (ESID)) that an OLT uses to decide sleep interval lengths for an ONU. Findings in this paper put forward the strong relationship among TCP traffic delay, throughput and ONU energy consumption under different sleep interval lengths. Moreover, we reveal that under high TCP traffic, both FSI and ESID will end up showing similar delay, energy and throughput performance. Our findings also show that doze mode can offer better TCP throughput and delay performance at the price of consuming more energy than cyclic sleep mode. In addition, our results provide a glimpse on understanding at what point doze mode becomes futile in improving energy saving of an ONU under TCP traffic. Furthermore, in this paper, we highlight important research issues that should be studied in future research to maximize energy saving in TDM-PONs while meeting traffic Quality of Service requirements.

  20. Serum neopterin and soluble CD163 as markers of macrophage activation in paracetamol (acetaminophen)-induced human acute liver injury.

    PubMed

    Craig, D G; Lee, P; Pryde, E A; Hayes, P C; Simpson, K J

    2013-12-01

    Macrophage activation is implicated in the pathogenesis of the systemic inflammatory response syndrome (SIRS) following paracetamol (acetaminophen) overdose (POD). Neopterin is synthesised from macrophages and reflects the intensity of monocyte/macrophage activation. Soluble CD163 (sCD163) is a marker of alternatively activated M2 macrophages. To examine neopterin and sCD163 levels in a cohort of acute liver injury patients. Consecutive patients (n = 41, (18 (43.9%) male) with acute liver injury were enrolled. Neopterin and sCD163 levels were measured by ELISA. A total of 24/33 (72.7%) POD patients developed hepatic encephalopathy (HE), and therefore acute liver failure. Both neopterin and sCD163 levels were significantly higher in PODs compared with chronic liver disease (neopterin P < 0.001, sCD163 P = 0.038) and healthy (both P < 0.001) controls. Admission neopterin levels were significantly higher in PODs: with HE (P = 0.001); with the SIRS (P = 0.005); who required renal replacement therapy (P = 0.003); who died or required liver transplantation (P = 0.006; AUROC 78.6% (95% CI 62.2-94.9%). Serum sCD163 levels were significantly higher in those PODs with the SIRS (P = 0.033) on admission, and were higher in those PODs who died or required OLT (P = 0.024). Both admission neopterin and sCD163 levels in PODs correlated with organ failure scores but not with serum ALT. There was no significant correlation between neopterin and sCD163 values. Both serum neopterin and sCD163 levels are significantly elevated following paracetamol overdose, and reflect the degree of macrophage activation in this condition. Serum neopterin in particular may have value as an early proxy marker of macrophage activation following paracetamol overdose. © 2013 John Wiley & Sons Ltd.

  1. Novel MDM-PON scheme utilizing self-homodyne detection for high-speed/capacity access networks.

    PubMed

    Chen, Yuanxiang; Li, Juhao; Zhu, Paikun; Wu, Zhongying; Zhou, Peng; Tian, Yu; Ren, Fang; Yu, Jinyi; Ge, Dawei; Chen, Jingbiao; He, Yongqi; Chen, Zhangyuan

    2015-12-14

    In this paper, we propose a cost-effective, energy-saving mode-division-multiplexing passive optical network (MDM-PON) scheme utilizing self-homodyne detection for high-speed/capacity access network based on low modal-crosstalk few-mode fiber (FMF) and all-fiber mode multiplexer/demultiplexer (MUX/DEMUX). In the proposed scheme, one of the spatial modes is used to transmit a portion of signal carrier (namely pilot-tone) as the local oscillator (LO), while the others are used for signal-bearing channels. At the receiver, the pilot-tone and the signal can be separated without strong crosstalk and sent to the receiver for coherent detection. The spectral efficiency (SE) is significantly enhanced when multiple spatial channels are used. Meanwhile, the self-homodyne detection scheme can effectively suppress laser phase noise, which relaxes the requirement for the lasers line-width at the optical line terminal or optical network units (OLT/ONUs). The digital signal processing (DSP) at the receiver is also simplified since it removes the need for frequency offset compensation and complex phase correction, which reduces the computational complexity and energy consumption. Polarization division multiplexing (PDM) that offers doubled SE is also supported by the scheme. The proposed scheme is scalable to multi-wavelength application when wavelength MUX/DEMUX is utilized. Utilizing the proposed scheme, we demonstrate a proof of concept 4 × 40-Gb/s orthogonal frequency division multiplexing (OFDM) transmission over 55-km FMF using low modal-crosstalk two-mode FMF and MUX/DEMUX with error free operation. Compared with back to back case, less than 1-dB Q-factor penalty is observed after 55-km FMF of the four channels. Signal power and pilot-tone power are also optimized to achieve the optimal transmission performance.

  2. Donor Age-Based Analysis of Liver Transplantation Outcomes: Short- and Long-Term Outcomes Are Similar Regardless of Donor Age.

    PubMed

    Chapman, William C; Vachharajani, Neeta; Collins, Kelly M; Garonzik-Wang, Jackie; Park, Yikyung; Wellen, Jason R; Lin, Yiing; Shenoy, Surendra; Lowell, Jeffrey A; Doyle, M B Majella

    2015-07-01

    The shortage of donor organs has led to increasing use of extended criteria donors, including older donors. The upper limit of donor age that produces acceptable outcomes continues to be explored. In liver transplantation, with appropriate selection, graft survival and patient outcomes would be comparable regardless of age. We performed a retrospective analysis of 1,036 adult orthotopic liver transplantations (OLT) from a prospectively maintained database performed between January 1, 2000 and December 31, 2013. The study focus group was liver transplantations performed using grafts from older (older than 60 years) deceased donors. Deceased donor liver transplantations done during the same time period using grafts from younger donors (younger than 60 years) were analyzed for comparison. Both groups were further divided based on recipient age (less than 60 years and 60 years or older). Donor age was the primary variable. Recipient variables included were demographics, indication for transplantation, Model for End-Stage Liver Disease (MELD), graft survival, and patient survival. Operative details and postoperative complications were analyzed. Patient demographics and perioperative details were similar between groups. Patient and graft survival rates were similar in the 4 groups. Rates of rejection (p = 0.07), bile leak (p = 0.17), and hepatic artery thrombosis were comparable across all groups (p = 0.84). Hepatitis C virus recurrence was similar across all groups (p = 0.10). Thirty-one young recipients (less than 60 years) received grafts from donors aged 70 or older. Their survival and other complication rates were comparable to those in the young donor to young recipient group. Comparable outcomes in graft and patient survivals were achieved using older donors (60 years or more), regardless of recipient age, without increased rate of complications. Copyright © 2015 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

  3. A SIEPON based transmitter sleep mode energy-efficient mechanism in EPON

    NASA Astrophysics Data System (ADS)

    Nikoukar, AliAkbar; Hwang, I.-Shyan; Wang, Chien-Jung; Ab-Rahman, Mohammad Syuhaimi; Liem, Andrew Tanny

    2015-06-01

    The main energy consumption in computer networks is the access networks. The passive optical network (PON) has the least energy consumption among access network technologies. In addition, the time division multiplexing (TDM) Ethernet PON (EPON) is one of the best candidates to improve energy consumption by time utilization. The optical network unit (ONU) can utilize the time and save the energy in the EPON by turning off its transmitter/receiver when there is no upstream/downstream traffic. The ITU-T and IEEE organizations are published standards for energy-saving in the TDM-PON. Although their standards provide the framework to accomplish the energy-saving, the algorithms/criteria to generate events to accommodate various operational policies, time to wake up, parameter values for timers are out of scope of the standards. Many studies have proposed schemes for energy-saving in TDM-PON to achieve maximum energy saving. Even so, these schemes increase the mean packet delay and consequently, reduce the quality of service (QoS). In this paper, first we take a look to the state of the art for PON energy-saving. Additionally, a mechanism based on SIEPON standard in EPON with new components in the ONUs and optical line terminal (OLT) is proposed to save the transmitter energy and guarantee QoS. The proposed mechanism follows the SIEPON standard, considers the QoS first, and then saves the energy as far as possible. The ONU sleep controller unit (OSC) and green dynamic bandwidth allocation (GDBA) are used to calculate the ONU transmitter sleep (Tx) duration and grant the proper time to the ONUs. Simulation results show that the proposed energy-saving mechanism not only promises the QoS performance in terms of mean packet delay, packet loss, throughput, and jitter, but also saves energy in different maximum cycle times.

  4. Full duplex fiber link for alternative wired and wireless access based on SSB optical millimeter-wave with 4-PAM signal

    NASA Astrophysics Data System (ADS)

    Ma, Jianxin; Zhang, Junjie

    2015-03-01

    A novel full-duplex fiber-wireless link based on single sideband (SSB) optical millimeter (mm)-wave with 10 Gbit/s 4-pulse amplitude modulation (PAM) signal is proposed to provide alternative wired and 40 GHz wireless accesses for the user terminals. The SSB optical mm-wave with 4-PAM signal consists of two tones: one bears the 4-PAM signal and the other is unmodulated with high power. After transmission over the fiber to the hybrid optical network unit (HONU), the SSB optical mm-wave signal can be decomposed by fiber Bragg gratings (FBGs) as the SSB optical mm-wave signal with reduced carrier-to-sideband ratio (the baseband 4-PAM optical signal) and the uplink optical carrier for the wireless (wired) access. This makes the HONU free from the laser source. For the uplink, since the wireless access signal is converted to the baseband by power detection, both the transmitter in the HONU and the receiver in optical line terminal (OLT) are co-shared for both wireless and wired accesses, which makes the full duplex link much simpler. In our scheme, the optical electrical field of the square-root increment level 4-PAM signal assures an equal level spacing receiving for both the downlink wired and wireless accesses. Since the downlink wireless signal is down-converted to the baseband by power detection, RF local oscillator is unnecessary. To confirm the feasibility of our proposed scheme, a simulation full duplex link with 40 GHz SSB optical mm-wave with 10 Gbit/s 4-PAM signal is built. The simulation results show that both down- and up-links for either wired or wireless access can keep good performance even if the link length of the SSMF is extended to 40 km.

  5. Network coding based joint signaling and dynamic bandwidth allocation scheme for inter optical network unit communication in passive optical networks

    NASA Astrophysics Data System (ADS)

    Wei, Pei; Gu, Rentao; Ji, Yuefeng

    2014-06-01

    As an innovative and promising technology, network coding has been introduced to passive optical networks (PON) in recent years to support inter optical network unit (ONU) communication, yet the signaling process and dynamic bandwidth allocation (DBA) in PON with network coding (NC-PON) still need further study. Thus, we propose a joint signaling and DBA scheme for efficiently supporting differentiated services of inter ONU communication in NC-PON. In the proposed joint scheme, the signaling process lays the foundation to fulfill network coding in PON, and it can not only avoid the potential threat to downstream security in previous schemes but also be suitable for the proposed hybrid dynamic bandwidth allocation (HDBA) scheme. In HDBA, a DBA cycle is divided into two sub-cycles for applying different coding, scheduling and bandwidth allocation strategies to differentiated classes of services. Besides, as network traffic load varies, the entire upstream transmission window for all REPORT messages slides accordingly, leaving the transmission time of one or two sub-cycles to overlap with the bandwidth allocation calculation time at the optical line terminal (the OLT), so that the upstream idle time can be efficiently eliminated. Performance evaluation results validate that compared with the existing two DBA algorithms deployed in NC-PON, HDBA demonstrates the best quality of service (QoS) support in terms of delay for all classes of services, especially guarantees the end-to-end delay bound of high class services. Specifically, HDBA can eliminate queuing delay and scheduling delay of high class services, reduce those of lower class services by at least 20%, and reduce the average end-to-end delay of all services over 50%. Moreover, HDBA also achieves the maximum delay fairness between coded and uncoded lower class services, and medium delay fairness for high class services.

  6. Liver transplantation in children with Alagille syndrome--a study of twelve cases.

    PubMed

    Cardona, J; Houssin, D; Gauthier, F; Devictor, D; Losay, J; Hadchouel, M; Bernard, O

    1995-08-27

    Cholestasis associated with Alagille syndrome may, in a few cases, be extremely severe and result in major impairment in the quality of life during early childhood and end up in cirrhosis eventually. We report the results of liver transplantation in 12 children with a severe hepatic form of Alagille syndrome. All children presented with cholestatic jaundice from birth, peculiar facies, stenosis of the peripheral pulmonary artery, and posterior embryotoxon; butterfly-like vertebrae were present in 9 children. At the time of transplantation (mean age 7 years 10 months) refractory pruritus was present in 9 children, xanthoma in 11, and height and weight retardation in 11. Total serum bilirubin ranged from 116 to 322 mumol/L and total serum cholesterol from 3.5 to 29 mmol/L. Systolic right ventricular pressure was moderately raised (36 to 48 mmHg) in 5 children; mean creatinine clearance was 99 ml/min/1.73 m2. Histologic examination of the removed livers showed cirrhosis, severe annular fibrosis, and moderate portal fibrosis in 4 children each. Follow-up in the 11 survivors has ranged from 14 months to 5 1/2 years. All lead normal lives. Pruritus and xanthomas disappeared. Increase in height was observed in 8 of the 10 survivors who had growth retardation prior to transplantation. School level is normal in 4 (median age at LT: 5 yr 9 mo) and below normal in 6 (median age at OLT: 9 yr 9 mo). Liver function tests are normal in 10 children. Mean creatinine clearance is 101 ml/min/1.73 m2. These results indicate that the quality of life can be considerably improved after liver transplantation in children with a severe hepatic form of Alagille syndrome and suggest that it could be carried out before these children attend elementary school.

  7. Centennial-millennial scale variations in Western Antarctic Ice Sheet discharge and their relationship to climate and ocean changes during the late Holocene

    NASA Astrophysics Data System (ADS)

    Snilstveit Hoem, Frida; Ninnemann, Ulysses S.; Kleiven, Helga (Kikki) F.; Irvali, Nil

    2017-04-01

    period of generally low IRD, coincides with Little Ice Age at 600 cal yr B.P. The local surface water hydrography appears relatively stable over the past 4000 years with the planktonic δ18O signal indicating centennial-millennial scale changes of typically ≤1˚ C (Δ0.22) and notably smaller in amplitude than the regional warming observed over the past century. The lack of correlation between surface water physical properties and IRD in the downcore records, suggests that IRD is not reflecting iceberg survival but rather changes in the supply (WAIS dynamics) or routing. Consistent with this interpretation, IRD covaries with climate on the Antarctic Peninsula (from JRI ice core) over the past 4 kyr with cooler conditions and lower amounts of IRD over much of the past two millennia than occurred earlier in the neoglaciation. Both records indicate a recovery with warming and increased IRD prior to industrialization. This relationship is consistent with the hypothesis that climate and specifically ocean temperatures were important for modulating WAIS discharge rates over the past few millennia.

  8. Risk factors and outcome in patients with primary sclerosing cholangitis with persistent biliary candidiasis.

    PubMed

    Rupp, Christian; Bode, Konrad Alexander; Chahoud, Fadi; Wannhoff, Andreas; Friedrich, Kilian; Weiss, Karl-Heinz; Sauer, Peter; Stremmel, Wolfgang; Gotthardt, Daniel Nils

    2014-10-23

    Candidiasis is commonly observed in patients with primary sclerosing cholangitis (PSC), but the clinical risk factors associated with its presence have not been fully investigated. In this study, we aimed to analyse the incidence, risk factors, and transplantation-free survival in primary sclerosing cholangitis (PSC) patients with persistent biliary candidiasis. We retrospectively analysed patients diagnosed with PSC who were admitted to our department during 2002 to 2012. One-hundred fifty patients whose bile cultures were tested for fungal species were selected, and their clinical and laboratory parameters were investigated. The results of endoscopic retrograde cholangiography (ERC) and bile cultures were analysed using chart reviews. The cases of biliary candidiasis were sub-classified as transient or persistent. Thirty out of 150 (20.0%) patients had biliary candidiasis. Although all patients demonstrated comparable baseline characteristics, those with biliary candidiasis showed significantly reduced transplantation-free survival (p < 0.0001) along with a markedly elevated frequency of cholangiocarcinoma (CCA) (p = 0.04). The patients were further sub-classified according to the transient (15/30) or persistent (15/30) nature of their biliary candidiasis. A subgroup analysis showed reduced survival with a greater necessity for orthotopic liver transplantation (OLT) only in patients with persistence of Candida (p = 0.007). The survival in the patients with transient biliary candidiasis was comparable to that in candidiasis-free patients. In a multivariate regression analysis that included Mayo risk score (MRS), sex, age, dominant stenosis, inflammatory bowel disease, autoimmune hepatitis overlap syndrome, and number of times ERC was performed, biliary candidiasis was an independent risk factor for reduced survival (p = 0.008). Risk factors associated with acquisition of biliary candidiasis were age at PSC diagnosis and number of ERCs. The persistence of biliary

  9. High Efficiency Automatic-Power-Controlled and Gain-Clamped EDFA for Broadband Passive Optical Networking Systems

    NASA Astrophysics Data System (ADS)

    Shen, Jyi-Lai; Wei, Shui-Ken; Lin, Chin-Yuan; Iong Li, Ssu; Huang, Chih-Chuan

    2010-04-01

    The configuration of a simple improved high efficiency automatic-power-controlled and gain-clamped EDFA (APC-GC-EDFA) for broadband passive optical networking systems (BPON) is presented here. In order to compensate the phase and amplitude variation due to the different distance between the optical line terminal (OLT) and optical network units (ONU), the APC-GC-EDFA need to be employed. A single 980 nm laser module is employed as the primary pump. To extend the bandwidth, all C-band ASE is recycled as the secondary pump to enhance the gain efficiency. An electrical feedback circuit is used as a multi-wavelength channel transmitter monitor for the automatic power control to improve the gain-flattened flatness for stable amplification. The experimental results prove that the EDFA system can provide flatter clamped gain in both C-band and L-band configurations. The gain flatness wavelength ranging from 1530 to 1610 nm is within 32.83 ± 0.64 dB, i.e. below 1.95 %. The gains are clamped at 33.85 ± 0.65 dB for the input signal power of -40 dBm to -10 dBm. The range of noise figure is between 6.37 and 6.56, which is slightly lower compared to that of unclamped amplifiers. This will be very useful for measuring the gain flatness of APC-GC-EDFA. Finally, we have also demonstrated the records of the overall simultaneous dynamics measurements for the new system stabilization. The carrier to noise ratio (CNR) is 49.5 to 50.8 dBc which is above the National Television System Committee (NTSC) standard of 43 dBc, and both composite second order (CSO) 69.2 to 71.5 dBc and composite triple beat (CTB) of 69.8 to 72.2 dBc are above 53 dBc. The recorded corresponding rise-time of 1.087 ms indicates that the system does not exhibit any overshoot of gain or ASE variation due to the signal at the beginning of the pulse.

  10. Ring-like reliable PON planning with physical constraints for a smart grid

    NASA Astrophysics Data System (ADS)

    Wang, Xin; Gu, Rentao; Ji, Yuefeng

    2016-01-01

    Due to the high reliability requirements in the communication networks of a smart grid, a ring-like reliable PON is an ideal choice to carry power distribution information. Economical network planning is also very important for the smart grid communication infrastructure. Although the ring-like reliable PON has been widely used in the real applications, as far as we know, little research has been done on the network optimization subject of the ring-like reliable PON. Most PON planning research studies only consider a star-like topology or cascaded PON network, which barely guarantees the reliability requirements of the smart grid. In this paper, we mainly investigate the economical network planning problem for the ring-like reliable PON of the smart grid. To address this issue, we built a mathematical model for the planning problem of the ring-like reliable PON, and the objective was to minimize the total deployment costs under physical constraints. The model is simplified such that all of the nodes have the same properties, except OLT, because each potential splitter site can be located in the same ONU position in power communication networks. The simplified model is used to construct an optimal main tree topology in the complete graph and a backup-protected tree topology in the residual graph. An efficient heuristic algorithm, called the Constraints and Minimal Weight Oriented Fast Searching Algorithm (CMW-FSA), is proposed. In CMW-FSA, a feasible solution can be obtained directly with oriented constraints and a few recursive search processes. From the simulation results, the proposed planning model and CMW-FSA are verified to be accurate (the error rates are less than 0.4%) and effective compared with the accurate solution (CAESA), especially in small and sparse scenarios. The CMW-FSA significantly reduces the computation time compared with the CAESA. The time complexity algorithm of the CMW-FSA is acceptable and calculated as T(n) = O(n3). After evaluating the

  11. Influence of chemical speciation and biofilm composition on mercury accumulation by freshwater biofilms.

    PubMed

    Dranguet, P; Le Faucheur, S; Cosio, C; Slaveykova, V I

    2017-01-25

    Mercury (Hg) is a pollutant of high concern for aquatic systems due to the biomagnification of its methylated form along the food chain. However, in contrast to other metals, gaining knowledge of its bioavailable forms for aquatic microorganisms remains challenging, making Hg risk assessment difficult. Ubiquitous and sessile freshwater biofilms are well known to accumulate and to transform Hg present in their ambient environment. The present study thus aims to evaluate whether non-extractable (proxy of intracellular) Hg accumulated by biofilms could be a good indicator of Hg bioavailability for microorganisms in freshwater. To that end, the link between Hg concentration and speciation, as well as biofilm composition (percentage of abiotic, biotic, chlorophyll and phycocyanin-fractions and abundance of dsrA, gcs, merA and hgcA bacterial genes) and biofilm Hg accumulation was examined. The studied biofilms were grown on artificial substrata in four reservoirs along the Olt River (Romania), which was contaminated by Hg coming from chlor-alkali plant effluents. The 0.45 μm-filterable Hg concentrations in ambient waters were measured and inorganic IHg speciation was modelled. Biofilms were analyzed for their non-extractable IHg and methylmercury (MeHg) contents as well as for their composition. The non-extractable IHg content was related, but not significantly, to the concentration of total IHg (r 2 = 0.88, p = 0.061) whereas a significant correlation was found with the predicted IHg concentration that is not bound to dissolved organic matter (r 2 = 0.95, p = 0.027), despite its extremely low concentrations (10 -25 M), showing a limitation of the thermodynamic Hg modelling to predict Hg bioavailability. The studied biofilms were different in biomass and composition and a principal component analysis showed that the non-extractable IHg content correlated with the abundance of the merA and hgcA genes, while MeHg accumulation was only linked with the abundance of the r

  12. TEM analysis of the initial stages of BaSO4 crystallization

    NASA Astrophysics Data System (ADS)

    Ruiz Agudo, Cristina; Putnis, Christine V.; Ruiz Agudo, Encarnación; Putnis, Andrew

    2014-05-01

    observed ex-situ in a Transmission Electron Microscope. We found that barite precipitation involves the initial formation of nanometer-size (5-10 nm) particles that fuse in an oriented way to form larger particles. Two hierarchical levels of aggregation are observed: first, the aggregation of 5-10 nm particles to form larger, but still nanometer-sized (20-60 nm) particles. In a second stage, these latter particles aggregate to produce larger single crystals (200-500 nm). No evidence of an amorphous or crystalline precursor phase previous to crystalline barite was found. These results are of importance for the design of scale prevention methods, particularly in the choice of the most suitable scale inhibitor. Gebauer D., Cölfen H., Verch A. and Antonietti M. (2009) The multiple roles of additives in CaCO3 crystallization: a quantitative case study. Adv. Mater. 21, 435-439. Gebauer D., Völkel A. and Cölfen H. (2008) Stable prenucleation calcium carbonate clusters. Science 332, 1819-1822. Van Driessche A.E.S., Benning L.G., Rodriguez-Blanco J. D., Ossorio M., Bots P. and García-Ruiz J. M. (2012) The role and implications of bassanite as a stable precursor phase to gypsum precipitation. Science 336, 69-71. Baumgartner J., Dey A., Bomans P. H. H., Le Coadou C., Fratzl P., Sommerdijk N. A. J. M. and Faivre D. (2013) Nucleation and growth of magnetite from solution. Nature 12, 310-314. Li D., Nielsen M.H., Lee J.R.I, Frandsen C., Banfield J.F. and De Yoreo J.J.(2012) Direction-Specific Interactions Control Crystal Growth by Oriented Attachment. Science 336, 1014-1018.

  13. Febuxostat for treating chronic gout

    PubMed Central

    Tayar, Jean H; Lopez-Olivo, Maria Angeles; Suarez-Almazor, Maria E

    2014-01-01

    Background Gout is the most common inflammatory arthritis in men over 40 years and has an increasing prevalence among postmenopausal women. Lowering serum uric acid levels remains one of the primary goals in the treatment of chronic gout. In clinical trials, febuxostat has been shown to be effective in lowering serum uric acid levels to < 6.0 mg/dL. Objectives To evaluate the benefits and harms of febuxostat for chronic gout. Search methods We searched The Cochrane Library, MEDLINE, EMBASE, and International Pharmaceutical Abstracts from inception to July 2011. The ClinicalTrials.gov website was searched for references to trials of febuxostat. Our search did not include any restrictions. Selection criteria Two authors independently reviewed the search results and disagreements were resolved by discussion. We included any controlled clinical trial or open label trial (OLT) using febuxostat at any dose. Data collection and analysis Data and risk of bias were independently extracted by two authors and summarised in a meta-analysis. Continuous data were expressed as mean difference and dichotomous data as risk ratio (RR). Main results Four randomised trials and two OLTs with 3978 patients were included. Risk of bias differed by outcome, ranging from low to high risk of bias. Included studies failed to report on five to six of the nine outcome measures recommended by OMERACT. Patients taking febuxostat 120 mg and 240 mg reported more frequent gout flares than in the placebo group at 4 to 28 weeks (RR 1.7; 95% CI 1.3 to 2.3, and RR 2.6; 95% CI 1.8 to 3.7 respectively). No statistically significant differences were observed at 40 mg and 80 mg. Compared to placebo, patients on febuxostat 40 mg were 40.1 times more likely to achieve serum uric acid levels < 6.0 mg/dL at 4 weeks (95% CI 2.5 to 639), with an absolute treatment benefit of 56% (95% CI 37% to 71%). For febuxostat 80 mg and 120 mg, patients were 68.9 and 80.7 times more likely to achieve serum uric acid levels

  14. Solutal convection induced by dissolution. Influence on erosion dynamics and interface shaping.

    NASA Astrophysics Data System (ADS)

    Berhanu, Michael; Philippi, Julien; Cohen, Caroline; Derr, Julien; Courrech du Pont, Sylvain

    2017-04-01

    dissolution patterns can be related to the characteristic of the convective flow. C. Oltéan, F. Golfier and M.A. Buès, Numerical and experimental investigation of buoyancy-driven dissolution in vertical fracture, J. Geophys. Res. Solid Earth, 118(5), 2038-2048 (2013) C. Cohen, M. Berhanu, J. Derr and S. Courrech du Pont, Erosion patterns on dissolving and melting bodies (2015 Gallery of Fluid motion), Phys. Rev. Fluids, 1, 050508 (2016) T. S. Sullivan, Y. Liu, and R. E. Ecke, Turbulent solutal convection and surface patterning in solid dissolution, Phys. Rev. E 54, 486 (1996)

  15. Melt Transport and Mantle Assimilation at Atlantis Massif (IODP Site U1309): Evidence from Chemical Profiles along Olivine Crystallographic Axes

    NASA Astrophysics Data System (ADS)

    Ferrando, C.; Godard, M.; Ildefonse, B.; Rampone, E.

    2017-12-01

    Olivine-rich troctolites (Ol > 70%, Ol T) indicate that extensive melt impregnation of preexisting Ol rich lithologies participate to the building of slow spread crust. To constrain their origin and their impact on the structure and geochemistry of oceanic crust, we realized a multi-scale petro-structural, geochemical, and numerical modelling study of Ol T drilled at IODP Hole U1309D (Atlantis Massif, Exp. 304/305). Ol T display deformed (high temperature imprint) corroded coarse grained to undeformed fine grained Ol embayed in poikilitic Cpx and Plg. Ol crystallographic preferred orientations show [001] cluster suggesting formation after impregnation and assimilation of a deformed Ol rich matrix at high melt/rock ratios. Ol have variable major and minor element compositions, but similar fractionated REE (DyN/YbN = 0.04 - 0.11). Chemical traverses along principal crystallographic axes of Ol are flat suggesting local equilibrium between Ol and neighboring phases. 3 types of Ol T were distinguished. Ol T 1 - 2 display sharp contacts. Ol T 1 has Ol <75% (single grains) and primitive compositions (Mg# = 85-86; Ni = 1870-2840 ppm, Mn = 1570-1950 ppm; Li = 1.2 - 2.7 ppm). Ol T 2 have high Ol ( > 75%, dominantly aggregates) yet more evolved composition (Mg# = 83-84, Ni = 1790 - 2510 ppm, Mn = 1760 - 1990 ppm, Li = 1.5 - 3.9 ppm) in contrast to modal and composition trends predicted by MORB crystallization. Ol T 3 has diffusive contacts with gabbroic veins, variable modal Ol with the most evolved compositions and record late stages of Ol-T formation. Ol T compositions are best modelled assuming percolation of primitive MORB melts into Hole U1309B harzburgite, triggering Opx dissolution, followed by Ol assimilation and Plg + Cpx crystallization. Modelling shows that Ol Ni variations at constant Mg# in Ol T are mantle inherited. Ol T 1 compositions were fitted assuming higher Ol assimilation (Ma = 0.06 - 0.13) in contrast to Ol T 2 -3 (Ma = 0.01 - 0.02). Ol T 3 was `buffered

  16. Optimal reentry prediction of space objects from LEO using RSM and GA

    NASA Astrophysics Data System (ADS)

    Mutyalarao, M.; Raj, M. Xavier James

    2012-07-01

    The accurate estimation of the orbital life time (OLT) of decaying near-Earth objects is of considerable importance for the prediction of risk object re-entry time and hazard assessment as well as for mitigation strategies. Recently, due to the reentries of large number of risk objects, which poses threat to the human life and property, a great concern is developed in the space scientific community all over the World. The evolution of objects in Low Earth Orbit (LEO) is determined by a complex interplay of the perturbing forces, mainly due to atmospheric drag and Earth gravity. These orbits are mostly in low eccentric (eccentricity < 0.2) and have variations in perigee and apogee altitudes due to perturbations during a revolution. The changes in the perigee and apogee altitudes of these orbits are mainly due to the gravitational perturbations of the Earth and the atmospheric density. It has become necessary to use extremely complex force models to match with the present operational requirements and observational techniques. Further the re-entry time of the objects in such orbits is sensitive to the initial conditions. In this paper the problem of predicting re-entry time is attempted as an optimal estimation problem. It is known that the errors are more in eccentricity for the observations based on two line elements (TLEs). Thus two parameters, initial eccentricity and ballistic coefficient, are chosen for optimal estimation. These two parameters are computed with response surface method (RSM) using a genetic algorithm (GA) for the selected time zones, based on rough linear variation of response parameter, the mean semi-major axis during orbit evolution. Error minimization between the observed and predicted mean Semi-major axis is achieved by the application of an optimization algorithm such as Genetic Algorithm (GA). The basic feature of the present approach is that the model and measurement errors are accountable in terms of adjusting the ballistic coefficient

  17. Four-fold increase in users of time-wavelength division multiplexing (TWDM) passive optical network (PON) by delayed optical amplitude modulation (AM) upstream

    NASA Astrophysics Data System (ADS)

    Kachhatiya, Vivek; Prince, Shanthi

    2016-12-01

    In this paper, we have proposed and simulated optical time division multiplexed passive optical network (TDM-PON) using delayed optical amplitude modulation (AM). Eight upstream wavelengths are demonstrated to show optical time wavelength division multiplexed (TWDM) by combining optical network units (ONU) users data at the remote node (RN). Each ONU generates 2.5 Gb/s user data, and it is modulated using novel return to zero (RZ) delayed AM. Optical TDM aggregates 10 Gb/s data per wavelength from four 2.5 Gb/s upstream user data, which facilitates four different ONU data on the same wavelength as 10 Gb/s per upstream wavelength and, simplify the laser requirements (2.5 Gb/s) at each optical network unit (ONU) transmitter. Upstream optical TWDM-PON is investigated for eight wavelengths with wavelength spacing of 100 GHz. Novel optical TDM for upstream increased the number of the simultaneous user to fourfold from conventional TWDM-PON using delayed AM with a high-quality-factor of received signal. Despite performance degradation due to different fiber reach and dispersion compensation technique, Optical TWDM link shows significant improvement regarding receiver sensitivity when compared with common TWDM link. Hence, it offers optimistic thinking to show optical TDM at this phase as one of the future direction, where complex digital signal processing (DSP) and coherent optical communication are frequently demonstrated to serve the access network. Downstream side conventional TWDM eight wavelengths are multiplexed at the OLT and sent downstream to serve distributed tunable ONU receivers through an optical distribution network (ODN). Each downstream wavelengths are modulated at the peak rate of 10 Gb/s using non-return to zero external modulation (NRZ-EM). The proposed architecture is cost efficient and supports high data rates as well as ;pay as you grow; network for both service providers and the users perspectives. Users are classified into two categories viz home

  18. Metroticket 2.0 Model for Analysis of Competing Risks of Death After Liver Transplantation for Hepatocellular Carcinoma.

    PubMed

    Mazzaferro, Vincenzo; Sposito, Carlo; Zhou, Jian; Pinna, Antonio D; De Carlis, Luciano; Fan, Jia; Cescon, Matteo; Di Sandro, Stefano; Yi-Feng, He; Lauterio, Andrea; Bongini, Marco; Cucchetti, Alessandro

    2018-01-01

    % chance of HCC-specific survival 5 years after transplantation, their level of AFP should be <200 ng/mL and the sum of number and size of tumors (in centimeters) should not exceed 7; if the level of AFP was 200-400 ng/mL, the sum of the number and size of tumors should be ≤5; if their level of AFP was 400-1000 ng/mL, the sum of the number and size of tumors should be ≤4. In the validation set, the model identified patients who survived 5 years after liver transplantation with 0.721 accuracy (95% confidence interval, 0.648%-0.793%). Our model, based on patients' level of AFP and HCC number and size, outperformed the Milan; University of California, San Francisco; Shanghai-Fudan; Up-to-7 criteria (P < .001); and AFP French model (P = .044) to predict which patients will survive for 5 years after liver transplantation. We developed a model based on level of AFP, tumor size, and tumor number, to determine risk of death from HCC-related factors after liver transplantation. This model might be used to select end points and refine selection criteria for liver transplantation for patients with HCC. To predict 5-year survival and risk of HCC-related death using an online calculator, please see www.hcc-olt-metroticket.org/. ClinicalTrials.gov ID NCT02898415. Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.

  19. Inelastic processes in atomic collisions involving ground state and laser-prepared atoms

    NASA Astrophysics Data System (ADS)

    Planje, Willem Gilles

    1999-11-01

    In dit proefschrift worden experimenten beschreven waarbij ionen of atomen met een bepaalde snelheid op een ensemble van doelwitatomen worden gericht. Wanneer twee deeltjes elkaar voldoende genaderd hebben, vindt er wissel- werking plaats waarbij allerlei processen kunnen optreden. Deze processen resulteren in specieke eindproducten. Kennis over de interactie tussen twee botsingspartners wordt verkregen door te bekijken welke eindproducten ontstaan, en in welke mate. Een belangrijke grootheid die van invloed is op mogelijke processen is de onderlinge snelheid van de twee kernen, oftewel de botsingssnelheid. Wanneer de botsingssnelheid voldoende klein is dan kunnen de verschillende reactiemechanismen zowel kwalitatief als kwanti- tatief vaak goed voorspeld worden door het systeem te beschouwen als een kort-stondig molecuul, opgebouwd uit de twee botsende deeltjes. De ver- schillende processen die kunnen optreden worden gekwaliceerd afhankelijk van de vorming van bepaalde eindproducten. Ruwweg de volgende indeling kan gemaakt worden: 1. de interne structuur van de eindproducten zijn identiek aan die van de beginproducten. We spreken dan van een elastische botsing. 2. e en van de deeltjes of beiden worden in een aangeslagen toestand ge- bracht (of ge¨oniseerd). Dit zijn processen waarbij de herschikte elek- tronen zich bij de oorspronkelijke kern bevinden. We spreken dan van excitatie of ionisatie. 3. e en of meerdere elektronen bevinden zich bij de andere kern na de botsing (eventueel in aangeslagen toestand). We spreken dan van elek- tronenoverdracht. In het eerste deel van deze dissertatie worden botsingsexperimenten tussen heliumionen en natriumatomen beschreven waarbij het proces van elek- tronenoverdracht wordt onderzocht. Bij dit mechanisme is het buitenste 117?Samenvatting natriumelektron betrokken. Deze kan relatief gemakkelijk `overspringen' naar het heliumion wanneer deze zich dicht in de buurt van het natrium- atoom bevindt. Het elektron kan hierbij een