Treatment outcomes and patient-reported quality of life after orthognathic surgery with computer-assisted 2- or 3-dimensional planning: A randomized double-blind active-controlled clinical trial.

PubMed

Bengtsson, Martin; Wall, Gert; Larsson, Pernilla; Becktor, Jonas P; Rasmusson, Lars

2018-06-01

Thorough treatment planning is essential for a good clinical outcome in orthognathic treatment. The planning is often digital. Both 2-dimensional (2D) and 3-dimensional (3D) software options are available. The aim of this randomized 2-arm parallel double-blinded active-controlled clinical trial was to compare the outcomes of computer-based 2D and 3D planning techniques according to patient-reported health related quality of life. The hypothesis was that a 3D technique would give a better treatment outcome compared with a 2D technique. Orthognathic treatment for 62 subjects, aged 18 to 28 years, with severe Class III malocclusion was planned with both 2D and 3D techniques. After treatment planning but before surgery, the patients were randomly allocated via blind collection of 1 enveloped card for each subject in a 1:1 ratio to the test (3D) or the control (2D) group. Thus, the intervention was according to which planning technique was used. The primary outcome was patient-reported outcome measures. The secondary outcome was relationship between patient-reported outcome measures and cephalometric accuracy. Questionnaires on the patient's health-related quality of life (HRQoL) were distributed preoperatively and 12 months after surgical treatment. The questionnaires were coded, meaning blinding throughout the analysis. Differences between groups were tested with the Fisher permutation test. The HRQoL was also compared with measurements of cephalometric accuracy for the 2 groups. Three subjects were lost to clinical follow-up, leaving 57 included. Of these, 55 subjects completed the questionnaires, 28 in the 2D and 27 in the 3D groups. No statistically significant difference regarding HRQoL was found between the studied planning techniques: the Oral Health Impact Profile total showed -3.69 (95% confidence interval, -19.68 to 12.30). Consistent results on HRQoL and cephalometric accuracy showed a difference between pretreatment and posttreatment that increased in both groups but to a higher level in the 3D group. A difference between pretreatment and posttreatment HRQoL was shown for both groups, indicating increased quality of life after treatment. This supports recent findings comparing 3D and 2D planning techniques. No serious harm was observed during the study. Improvements of HRQoL were shown after treatment independent of which planning technique, 2D or 3D, was used. No statistically significant difference was found between the planning techniques. This trial was not registered. The protocol was not published before trial commencement. This project was supported by personal grants to Martin Bengtsson from the Scandinavian Association of Oral and Maxillofacial Surgeons (25000 SEK), the Southern Region of the Swedish Dental Association (50000 SEK), and the Swedish Association of Oral and Maxillofacial Surgeons (25000 SEK). The sponsors had no influence on the study design, analysis of the data, or the writing of the article. Copyright © 2018 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Automated Prescription of Oblique Brain 3D MRSI

PubMed Central

Ozhinsky, Eugene; Vigneron, Daniel B.; Chang, Susan M.; Nelson, Sarah J.

2012-01-01

Two major difficulties encountered in implementing Magnetic Resonance Spectroscopic Imaging (MRSI) in a clinical setting are limited coverage and difficulty in prescription. The goal of this project was to completely automate the process of 3D PRESS MRSI prescription, including placement of the selection box, saturation bands and shim volume, while maximizing the coverage of the brain. The automated prescription technique included acquisition of an anatomical MRI image, optimization of the oblique selection box parameters, optimization of the placement of OVS saturation bands, and loading of the calculated parameters into a customized 3D MRSI pulse sequence. To validate the technique and compare its performance with existing protocols, 3D MRSI data were acquired from 6 exams from 3 healthy volunteers. To assess the performance of the automated 3D MRSI prescription for patients with brain tumors, the data were collected from 16 exams from 8 subjects with gliomas. This technique demonstrated robust coverage of the tumor, high consistency of prescription and very good data quality within the T2 lesion. PMID:22692829

Three-dimensional kinematic estimation of mobile-bearing total knee arthroplasty from x-ray fluoroscopic images

NASA Astrophysics Data System (ADS)

Yamazaki, Takaharu; Futai, Kazuma; Tomita, Tetsuya; Sato, Yoshinobu; Yoshikawa, Hideki; Tamura, Shinichi; Sugamoto, Kazuomi

2011-03-01

To achieve 3D kinematic analysis of total knee arthroplasty (TKA), 2D/3D registration techniques, which use X-ray fluoroscopic images and computer-aided design (CAD) model of the knee implant, have attracted attention in recent years. These techniques could provide information regarding the movement of radiopaque femoral and tibial components but could not provide information of radiolucent polyethylene insert, because the insert silhouette on X-ray image did not appear clearly. Therefore, it was difficult to obtain 3D kinemaitcs of polyethylene insert, particularly mobile-bearing insert that move on the tibial component. This study presents a technique and the accuracy for 3D kinematic analysis of mobile-bearing insert in TKA using X-ray fluoroscopy, and finally performs clinical applications. For a 3D pose estimation technique of the mobile-bearing insert in TKA using X-ray fluoroscopy, tantalum beads and CAD model with its beads are utilized, and the 3D pose of the insert model is estimated using a feature-based 2D/3D registration technique. In order to validate the accuracy of the present technique, experiments including computer simulation test were performed. The results showed the pose estimation accuracy was sufficient for analyzing mobile-bearing TKA kinematics (the RMS error: about 1.0 mm, 1.0 degree). In the clinical applications, seven patients with mobile-bearing TKA in deep knee bending motion were studied and analyzed. Consequently, present technique enables us to better understand mobile-bearing TKA kinematics, and this type of evaluation was thought to be helpful for improving implant design and optimizing TKA surgical techniques.

A new furostanol glycoside from Tribulus terrestris.

PubMed

Xu, Yajuan; Liu, Yonghong; Xu, Tunhai; Xie, Shengxu; Si, Yunshan; Liu, Yue; Zhou, Haiou; Liu, Tonghua; Xu, Dongming

2010-01-27

Besides two known glycosides, a new furostanol glycoside was isolated from the Fruits of Tribulus terrestris L. The structure of the new furostanol glycoside was established as 26-O-beta-D-glucopyranosyl-(25S)-5alpha-furostane-20(22)-en-12-one-3beta, 26-diol-3-O-alpha-L-rhamnopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->4)]-beta-D-galactopyranoside (1) on the basis of 1D and 2D-NMR techniques, including COSY, HMBC, and HMQC correlations.

[Sesquiterpenoids of Coniogramme maxima].

PubMed

Chen, Yunfei; Liu, Shoujin; Wang, Fei

2012-04-01

To study sesquiterpenoids of Coniogramme maxima. Chemical constituents were separated by chromatography and their structures were identified according to physicochemical property and spectrum data. Fifteen compounds were separated by chromatography technique. Their structures were determined by spectral data, including 10 sesquiterpenoids as (3S)-pteroside D (1), epi-pterosin L (2), pterosin D (3), onitin (4), pterosin Z (5), onitisin (6), onitisin-glucopyranoside (7), onitin-15-O-beta-D-glucopyranoside (8), (2S,3R)-pterosin-L-2'-O-beta-D-glucopyranoside (9) and (3R)-peterosin D-3-O-beta-D-glucopyranoside (10). The other compounds were uracil (11), 3,4-dihydroxybenzaldehyde (12), 5-hydroxymethyl-2-furancarboxaldehyde (13), beta-sitosterol (14) and daucosterol (15). The above 15 compounds are separated from C. maxima for the first time, including 9 compounds being first separated from genus Coniogramme.

Two new grayanane diterpenoids from the flowers of Rhododendron molle.

PubMed

Zhang, Zhi-Run; Zhong, Jin-Dong; Li, Hong-Mei; Li, Hai-Zhou; Li, Rong-Tao; Deng, Xu-Liang

2012-01-01

A phytochemical investigation of the flowers of Rhododendron molle has yielded two new grayanane diterpenoids, rhodomolleins F and G (1, 2). Compounds 1 and 2 possessed an oxo-bridge between C-5 and C-9, and their structures were elucidated on the basis of interpretation of spectroscopic data, including 1D and 2D NMR techniques.

Synthesis of Two-Dimensional Materials for Capacitive Energy Storage

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

Mendoza-Sánchez, Beatriz; Gogotsi, Yury

The unique properties and great variety of two-dimensional (2D) nanomaterials make them highly attractive for energy storage applications. Here, an insight into the progress made towards the application of 2D nanomaterials for capacitive energy storage is provided. Moreover, synthesis methods, and electrochemical performance of various classes of 2D nanomaterials, particularly based on graphene, transition metal oxides, dichalcogenides, and carbides, are presented. Some factors that directly influence capacitive performance are discussed throughout the text and include nanosheet composition, morphology and texture, electrode architecture, and device configuration. Recent progress in the fabrication of 2D-nanomaterials-based microsupercapacitors and flexible and free-standing supercapacitors is presented.more » The main electrode manufacturing techniques with emphasis on scalability and cost-effectiveness are discussed, and include laser scribing, printing, and roll-to-roll manufacture. Some various issues that prevent the use of the full energy-storage potential of 2D nanomaterials and how they have been tackled are discussed, and include nanosheet aggregation and the low electrical conductivity of some 2D nanomaterials. In particular, the design of hybrid and hierarchical 2D and 3D structures based on 2D nanomaterials is presented. Other challenges and opportunities are discussed and include: control of nanosheets size and thickness, chemical and electrochemical instability, and scale-up of electrode films.« less

Synthesis of Two-Dimensional Materials for Capacitive Energy Storage

DOE PAGES

Mendoza-Sánchez, Beatriz; Gogotsi, Yury

2016-06-02

The unique properties and great variety of two-dimensional (2D) nanomaterials make them highly attractive for energy storage applications. Here, an insight into the progress made towards the application of 2D nanomaterials for capacitive energy storage is provided. Moreover, synthesis methods, and electrochemical performance of various classes of 2D nanomaterials, particularly based on graphene, transition metal oxides, dichalcogenides, and carbides, are presented. Some factors that directly influence capacitive performance are discussed throughout the text and include nanosheet composition, morphology and texture, electrode architecture, and device configuration. Recent progress in the fabrication of 2D-nanomaterials-based microsupercapacitors and flexible and free-standing supercapacitors is presented.more » The main electrode manufacturing techniques with emphasis on scalability and cost-effectiveness are discussed, and include laser scribing, printing, and roll-to-roll manufacture. Some various issues that prevent the use of the full energy-storage potential of 2D nanomaterials and how they have been tackled are discussed, and include nanosheet aggregation and the low electrical conductivity of some 2D nanomaterials. In particular, the design of hybrid and hierarchical 2D and 3D structures based on 2D nanomaterials is presented. Other challenges and opportunities are discussed and include: control of nanosheets size and thickness, chemical and electrochemical instability, and scale-up of electrode films.« less

A new triterpenoid saponin from Gymnema sylvestre.

PubMed

Zhang, Man-Qi; Liu, Yue; Xie, Sheng-Xu; Xu, Tun-Hai; Liu, Tong-Hua; Xu, Ya-Juan; Xu, Dong-Ming

2012-01-01

Besides four known compounds, a new triterpenoid saponin was isolated from the stems of Gymnema sylvestre. The structure of the new triterpenoid saponin was established as 3β,16β,22α-trihydroxy-olean-12-ene 3-O-β-D-xylopyranosyl-(1 → 6)-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranoside (1) on the basis of 1D and 2D NMR techniques, including COSY, HMBC, HMQC, and NOESY correlations. Four known compounds 2, 3, 4, and 5 were identified on the basis of spectroscopic data.

Lesion Detection in CT Images Using Deep Learning Semantic Segmentation Technique

NASA Astrophysics Data System (ADS)

Kalinovsky, A.; Liauchuk, V.; Tarasau, A.

2017-05-01

In this paper, the problem of automatic detection of tuberculosis lesion on 3D lung CT images is considered as a benchmark for testing out algorithms based on a modern concept of Deep Learning. For training and testing of the algorithms a domestic dataset of 338 3D CT scans of tuberculosis patients with manually labelled lesions was used. The algorithms which are based on using Deep Convolutional Networks were implemented and applied in three different ways including slice-wise lesion detection in 2D images using semantic segmentation, slice-wise lesion detection in 2D images using sliding window technique as well as straightforward detection of lesions via semantic segmentation in whole 3D CT scans. The algorithms demonstrate superior performance compared to algorithms based on conventional image analysis methods.

Quantitative Imaging of D-2-Hydroxyglutarate in Selected Histological Tissue Areas by a Novel Bioluminescence Technique.

PubMed

Voelxen, Nadine F; Walenta, Stefan; Proescholdt, Martin; Dettmer, Katja; Pusch, Stefan; Mueller-Klieser, Wolfgang

2016-01-01

Patients with malignant gliomas have a poor prognosis with average survival of less than 1 year. Whereas in other tumor entities the characteristics of tumor metabolism are successfully used for therapeutic approaches, such developments are very rare in brain tumors, notably in gliomas. One metabolic feature characteristic of gliomas, in particular diffuse astrocytomas and oligodendroglial tumors, is the variable content of D-2-hydroxyglutarate (D2HG), a metabolite that was discovered first in this tumor entity. D2HG is generated in large amounts due to various "gain-of-function" mutations in the isocitrate dehydrogenases IDH1 and IDH2. Meanwhile, D2HG has been detected in several other tumor entities, including intrahepatic bile-duct cancer, chondrosarcoma, acute myeloid leukemia, and angioimmunoblastic T-cell lymphoma. D2HG is barely detectable in healthy tissue (<0.1 mM), but its concentration increases up to 35 mM in malignant tumor tissues. Consequently, the "oncometabolite" D2HG has gained increasing interest in the field of tumor metabolism. To facilitate its quantitative measurement without loss of spatial resolution at a microscopical level, we have developed a novel bioluminescence assay for determining D2HG in sections of snap-frozen tissue. The assay was verified independently by photometric tests and liquid chromatography/mass spectrometry. The novel technique allows the microscopically resolved determination of D2HG in a concentration range of 0-10 μmol/g tissue (wet weight). In combination with the already established bioluminescence imaging techniques for ATP, glucose, pyruvate, and lactate, the novel D2HG assay enables a comparative characterization of the metabolic profile of individual tumors in a further dimension.

Technical Note: Guidelines for the digital computation of 2D and 3D enamel thickness in hominoid teeth.

PubMed

Benazzi, Stefano; Panetta, Daniele; Fornai, Cinzia; Toussaint, Michel; Gruppioni, Giorgio; Hublin, Jean-Jacques

2014-02-01

The study of enamel thickness has received considerable attention in regard to the taxonomic, phylogenetic and dietary assessment of human and non-human primates. Recent developments based on two-dimensional (2D) and three-dimensional (3D) digital techniques have facilitated accurate analyses, preserving the original object from invasive procedures. Various digital protocols have been proposed. These include several procedures based on manual handling of the virtual models and technical shortcomings, which prevent other scholars from confidently reproducing the entire digital protocol. There is a compelling need for standard, reproducible, and well-tailored protocols for the digital analysis of 2D and 3D dental enamel thickness. In this contribution we provide essential guidelines for the digital computation of 2D and 3D enamel thickness in hominoid molars, premolars, canines and incisors. We modify previous techniques suggested for 2D analysis and we develop a new approach for 3D analysis that can also be applied to premolars and anterior teeth. For each tooth class, the cervical line should be considered as the fundamental morphological feature both to isolate the crown from the root (for 3D analysis) and to define the direction of the cross-sections (for 2D analysis). Copyright © 2013 Wiley Periodicals, Inc.

Electrospinning: A versatile technique for making of 1D growth of nanostructured nanofibers and its applications: An experimental approach

NASA Astrophysics Data System (ADS)

Patil, Jyoti V.; Mali, Sawanta S.; Kamble, Archana S.; Hong, Chang K.; Kim, Jin H.; Patil, Pramod S.

2017-11-01

One dimensional (1D) metal oxide nanostructures (1D-MONS) play a key role in the development of functional devices including energy conversion, energy storage and environmental devices. They are also used for some important biomedical products like wound dressings, filter media, drug delivery and tissue engineering. The electrospinning (ES) is the versatile technique for making of 1D growth of nanostructured nanofibers, an experimental approach and its applications. The present review is focused on the 1D growth of nanostructured nanofibers in different applications like dye sensitized solar cells, perovskite solar cells, fuel cells, lithium ion batteries, redox flow batteries, supercapacitor, photocatalytic, and gas sensors based on ZnO, TiO2, MnO2, WO3, V2O5, NiO, SnO2, Fe2O3 etc. metal oxides, their composites and carbon. This review article presents an introduction to various types of ES techniques and their technical details. Also, the advantages and disadvantages of each ES technique are summarized. The various technical details such as preparative parameters, post-deposition methods, applied electric field, solution feed rate and a distance between a tip to the collector are the key factors in order to obtain exotic 1D nanostructured materials. Also, the lucid literature survey on the growth of nanostructures of various metal oxides and application in different fields are covered in this review. Further, the future perspectives has also been discussed.

Photonics of 2D gold nanolayers on sapphire surface

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

Muslimov, A. E., E-mail: amuslimov@mail.ru; Butashin, A. V.; Nabatov, B. V.

Gold layers with thicknesses of up to several nanometers, including ordered and disordered 2D nanostructures of gold particles, have been formed on sapphire substrates; their morphology is described; and optical investigations are carried out. The possibility of increasing the accuracy of predicting the optical properties of gold layers and 2D nanostructures using quantum-mechanical models based on functional density theory calculation techniques is considered. The application potential of the obtained materials in photonics is estimated.

High-resolution vascular tissue characterization in mice using 55 MHz ultrasound hybrid imaging

PubMed Central

Mahmoud, Ahmed M.; Sandoval, Cesar; Teng, Bunyen; Schnermann, Jurgen B.; Martin, Karen H.; Mustafa, S. Jamal; Mukdadi, Osama M.

2012-01-01

Ultrasound and Duplex ultrasonography in particular are routinely used to diagnose cardiovascular disease (CVD), which is the leading cause of morbidity and mortality worldwide. However, these techniques may not be able to characterize vascular tissue compositional changes due to CVD. This work describes an ultrasound-based hybrid imaging technique that can be used for vascular tissue characterization and the diagnosis of atherosclerosis. Ultrasound radiofrequency (RF) data were acquired and processed in time, frequency, and wavelet domains to extract six parameters including time integrated backscatter (TIB), time variance (Tvar), time entropy (TE), frequency integrated backscatter (FIB), wavelet root mean square value (Wrms), and wavelet integrated backscatter (WIB). Each parameter was used to reconstruct an image co-registered to morphological B-scan. The combined set of hybrid images were used to characterize vascular tissue in vitro and in vivo using three mouse models including control (C57BL/6), and atherosclerotic apolipoprotein E-knockout (APOE-KO) and APOE/A1 adenosine receptor double knockout (DKO) mice. The technique was tested using high-frequency ultrasound including single-element (center frequency = 55 MHz) and commercial array (center frequency = 40 MHz) systems providing superior spatial resolutions of 24 μm and 40 μm, respectively. Atherosclerotic vascular lesions in the APOE-KO mouse exhibited the highest values (contrast) of −10.11 ± 1.92 dB, −12.13 ± 2.13 dB, −7.54 ± 1.45 dB, −5.10 ± 1.06 dB, −5.25 ± 0.94 dB, and −10.23 ± 2.12 dB in TIB, Tvar, TE, FIB, Wrms, WIB hybrid images (n = 10, p < 0.05), respectively. Control segments of normal vascular tissue showed the lowest values of −20.20 ± 2.71 dB, −22.54 ± 4.54 dB, −14.94 ± 2.05 dB, −9.64 ± 1.34 dB, −10.20 ± 1.27 dB, and −19.36 ± 3.24 dB in same hybrid images (n = 6, p < 0.05). Results from both histology and optical images showed good agreement with ultrasound findings within a maximum error of 3.6% in lesion estimation. This study demonstrated the feasibility of a high-resolution hybrid imaging technique to diagnose atherosclerosis and characterize plaque components in mouse. In the future, it can be easily implemented on commercial ultrasound systems and eventually translated into clinics as a screening tool for atherosclerosis and the assessment of vulnerable plaques. PMID:23218908

Automated prescription of oblique brain 3D magnetic resonance spectroscopic imaging.

PubMed

Ozhinsky, Eugene; Vigneron, Daniel B; Chang, Susan M; Nelson, Sarah J

2013-04-01

Two major difficulties encountered in implementing Magnetic Resonance Spectroscopic Imaging (MRSI) in a clinical setting are limited coverage and difficulty in prescription. The goal of this project was to automate completely the process of 3D PRESS MRSI prescription, including placement of the selection box, saturation bands and shim volume, while maximizing the coverage of the brain. The automated prescription technique included acquisition of an anatomical MRI image, optimization of the oblique selection box parameters, optimization of the placement of outer-volume suppression saturation bands, and loading of the calculated parameters into a customized 3D MRSI pulse sequence. To validate the technique and compare its performance with existing protocols, 3D MRSI data were acquired from six exams from three healthy volunteers. To assess the performance of the automated 3D MRSI prescription for patients with brain tumors, the data were collected from 16 exams from 8 subjects with gliomas. This technique demonstrated robust coverage of the tumor, high consistency of prescription and very good data quality within the T2 lesion. Copyright © 2012 Wiley Periodicals, Inc.

Dinoxin B, A Novel Withanolide from Datura innoxia Leaf with specific Anti-cancer Activities

USDA-ARS?s Scientific Manuscript database

A new withanolide, dinoxin B (12,21-dihydroxy-1-oxowitha-2,6,24-trienolide-27-O-'-D-glucopyranoside) (1), was isolated from a methanol extract of Datura innoxia Mill. leaves, using bioassay guided fractionation. The structure was determined by spectroscopic techniques, including 1H, 13C-NMR, and 2D...

Nanoassembly of nanostructures by cutting, bending and soldering of carbon nanotubes with electron beam.

PubMed

Liu, Pou; Kantola, Kalle; Fukuda, Toshio; Arai, Fumihito

2009-05-01

We report that a series of in situ nanofabrication techniques of nanostructures, including cutting, bending and soldering of carbon nanotubes (CNTs), inside a field emission scanning electron microscope (FE-SEM) used for nanoassembly of nanostructures. The CNTs can be cut with electron beam assisted with oxygen gas. The cutting was developed for the bending of CNT, if some conditions of the cutting technique are changed. These include the increase of the acceleration voltage and/or setting the oxygen gas nozzle farther from the sample, and/or reducing the irradiation time. Using the proposed bending method angles larger than 90 degrees can be formed and the location of the kink can be set accurately. It is also shown that tungsten can be deposited on a substrate by the electron-beam-induced deposition, if the oxygen of the proposed cutting technique is replaced by W(CO)6. In this paper, these three nanofabrication methods were employed in the creation of a two dimensional (2D) nanostructure, the letters N and U, and a three dimensional (3D) nanostructure, the letter N. The 2D letters were constructed from 6 CNTs assembled on a substrate while the 3D letter N was bended from a single CNT and fixed to stand on a substrate. Based on the high performance of the proposed techniques, it is suggested that the cutting, bending, and soldering techniques inside SEM will become widely utilized in the fabrication and assembly of nanodevices and in the characterization of nanomaterials.

Comparison of 2- and 3-dimensional shoulder ultrasound to magnetic resonance imaging in a community hospital for the detection of supraspinatus rotator cuff tears with improved worktime room efficiency.

PubMed

Co, Steven; Bhalla, Sonny; Rowan, Kevin; Aippersbach, Sven; Bicknell, Simon

2012-08-01

The purpose of this study was to evaluate whether 3-dimensional (3D) volumetric acquisition of shoulder ultrasound (US) data for supraspinatus rotator cuff tears is as sensitive when compared with conventional 2-dimensional (2D) US and routine magnetic resonance imaging (MRI), and whether there is improved workroom time efficiency when using the 3D technique compared with the 2D technique. In this prospective study, 39 shoulders underwent US and MRI examination of their rotator cuff to confirm the accuracy of both the 2D and 3D techniques. The difference in sensitivities was compared by using confidence interval analysis. The mean times required to obtain the 2D and 3D US data and to review the scans were compared by using a 1-tailed Wilcoxon test. Sensitivity and specificity of 2D US in detecting supraspinatus full- and partial-thickness tears was 100% and 96%, and 80% and 100%, respectively, and similar values were obtained with 3D US at 100% and 100%, and 90% and 96.6%, respectively. Analysis of the confidence limits of the sensitivities showed no significant difference. The mean time (± SD) of the overall 2D examination of the shoulder, including interpretation was 10.02 ± 3.28 minutes, whereas, for the 3D examination, it was 7.08 ± 0.35 minutes. Comparison between the 2 cohorts when using a 1-tailed Wilcoxon test showed a statistically significant difference (P < .05). 3D US of the shoulder is as accurate as 2D US when compared with MRI for the diagnosis of full- and partial-thickness supraspinatus rotator cuff tears, and 3D US examination significantly reduced the time between the initial scan and the radiologist interpretation, ultimately improving workplace efficiency. Copyright © 2012 Canadian Association of Radiologists. Published by Elsevier Inc. All rights reserved.

Comparison of IMRT versus 3D-CRT in the treatment of esophagus cancer

PubMed Central

Xu, Dandan; Li, Guowen; Li, Hongfei; Jia, Fei

2017-01-01

Abstract Background: Esophageal cancer (EC) is a common cancer with high mortality because of its rapid progression and poor prognosis. Radiotherapy is one of the most effective treatments for EC. Three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) are 2 recently developed radiotherapy techniques. IMRT is believed to be more effective than 3D-CRT in target coverage, dose homogeneity, and reducing toxicity to normal organs. However, these advantages have not been demonstrated in the treatment of EC. This meta-analysis was performed to compare IMRT and 3D-CRT in the treatment of EC in terms of dose–volume histograms and outcomes including survival and toxicity. Methods: A literature search was performed in PubMed, Embase, and the Cochrane library databases from their inceptions to Dec 30, 2016. Two authors independently assessed the included studies and extracted data. The average percent irradiated volumes of adjacent noncancerous organs were calculated and compared between IMRT and 3D-CRT. The odds ratio of overall survival (OS), and radiation pneumonitis and radiation esophagitis was also evaluated. Results: Totally 7 studies were included. Of them, 5 studies (80 patients) were included in the dosimetric comparison, 3 studies (871 patients) were included in the OS analysis, and 2 studies (205 patients) were included in the irradiation toxicity analysis. For lung in patients receiving doses ≥20 Gy and heart in patients receiving dose = 50 Gy, the average irradiated volumes of IMRT were less than those from 3D-CRT. IMRT resulted in a higher OS than 3D-CRT. However, no significant difference was observed in the incidence of radiation pneumonitis and radiation esophagitis between 2 radiotherapy techniques. Conclusion: Our data suggest that IMRT-delivered high radiation dose produces significantly less average percent volumes of irradiated lung and heart than 3D-CRT. IMRT is superior to 3D-CRT in the OS of EC while shows no benefit on radiation toxicity. PMID:28767597

Comparison of IMRT versus 3D-CRT in the treatment of esophagus cancer: A systematic review and meta-analysis.

PubMed

Xu, Dandan; Li, Guowen; Li, Hongfei; Jia, Fei

2017-08-01

Esophageal cancer (EC) is a common cancer with high mortality because of its rapid progression and poor prognosis. Radiotherapy is one of the most effective treatments for EC. Three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) are 2 recently developed radiotherapy techniques. IMRT is believed to be more effective than 3D-CRT in target coverage, dose homogeneity, and reducing toxicity to normal organs. However, these advantages have not been demonstrated in the treatment of EC. This meta-analysis was performed to compare IMRT and 3D-CRT in the treatment of EC in terms of dose-volume histograms and outcomes including survival and toxicity. A literature search was performed in PubMed, Embase, and the Cochrane library databases from their inceptions to Dec 30, 2016. Two authors independently assessed the included studies and extracted data. The average percent irradiated volumes of adjacent noncancerous organs were calculated and compared between IMRT and 3D-CRT. The odds ratio of overall survival (OS), and radiation pneumonitis and radiation esophagitis was also evaluated. Totally 7 studies were included. Of them, 5 studies (80 patients) were included in the dosimetric comparison, 3 studies (871 patients) were included in the OS analysis, and 2 studies (205 patients) were included in the irradiation toxicity analysis. For lung in patients receiving doses ≥20 Gy and heart in patients receiving dose = 50 Gy, the average irradiated volumes of IMRT were less than those from 3D-CRT. IMRT resulted in a higher OS than 3D-CRT. However, no significant difference was observed in the incidence of radiation pneumonitis and radiation esophagitis between 2 radiotherapy techniques. Our data suggest that IMRT-delivered high radiation dose produces significantly less average percent volumes of irradiated lung and heart than 3D-CRT. IMRT is superior to 3D-CRT in the OS of EC while shows no benefit on radiation toxicity.

A New CT Reconstruction Technique Using Adaptive Deformation Recovery and Intensity Correction (ADRIC)

PubMed Central

Zhang, You; Ma, Jianhua; Iyengar, Puneeth; Zhong, Yuncheng; Wang, Jing

2017-01-01

Purpose Sequential same-patient CT images may involve deformation-induced and non-deformation-induced voxel intensity changes. An adaptive deformation recovery and intensity correction (ADRIC) technique was developed to improve the CT reconstruction accuracy, and to separate deformation from non-deformation-induced voxel intensity changes between sequential CT images. Materials and Methods ADRIC views the new CT volume as a deformation of a prior high-quality CT volume, but with additional non-deformation-induced voxel intensity changes. ADRIC first applies the 2D-3D deformation technique to recover the deformation field between the prior CT volume and the new, to-be-reconstructed CT volume. Using the deformation-recovered new CT volume, ADRIC further corrects the non-deformation-induced voxel intensity changes with an updated algebraic reconstruction technique (‘ART-dTV’). The resulting intensity-corrected new CT volume is subsequently fed back into the 2D-3D deformation process to further correct the residual deformation errors, which forms an iterative loop. By ADRIC, the deformation field and the non-deformation voxel intensity corrections are optimized separately and alternately to reconstruct the final CT. CT myocardial perfusion imaging scenarios were employed to evaluate the efficacy of ADRIC, using both simulated data of the extended-cardiac-torso (XCAT) digital phantom and experimentally acquired porcine data. The reconstruction accuracy of the ADRIC technique was compared to the technique using ART-dTV alone, and to the technique using 2D-3D deformation alone. The relative error metric and the universal quality index metric are calculated between the images for quantitative analysis. The relative error is defined as the square root of the sum of squared voxel intensity differences between the reconstructed volume and the ‘ground-truth’ volume, normalized by the square root of the sum of squared ‘ground-truth’ voxel intensities. In addition to the XCAT and porcine studies, a physical lung phantom measurement study was also conducted. Water-filled balloons with various shapes/volumes and concentrations of iodinated contrasts were put inside the phantom to simulate both deformations and non-deformation-induced intensity changes for ADRIC reconstruction. The ADRIC-solved deformations and intensity changes from limited-view projections were compared to those of the ‘gold-standard’ volumes reconstructed from fully-sampled projections. Results For the XCAT simulation study, the relative errors of the reconstructed CT volume by the 2D-3D deformation technique, the ART-dTV technique and the ADRIC technique were 14.64%, 19.21% and 11.90% respectively, by using 20 projections for reconstruction. Using 60 projections for reconstruction reduced the relative errors to 12.33%, 11.04% and 7.92% for the three techniques, respectively. For the porcine study, the corresponding results were 13.61%, 8.78%, 6.80% by using 20 projections; and 12.14%, 6.91% and 5.29% by using 60 projections. The ADRIC technique also demonstrated robustness to varying projection exposure levels. For the physical phantom study, the average DICE coefficient between the initial prior balloon volume and the new ‘gold-standard’ balloon volumes was 0.460. ADRIC reconstruction by 21 projections increased the average DICE coefficient to 0.954. Conclusion The ADRIC technique outperformed both the 2D-3D deformation technique and the ART-dTV technique in reconstruction accuracy. The alternately solved deformation field and non-deformation voxel intensity corrections can benefit multiple clinical applications, including tumor tracking, radiotherapy dose accumulation and treatment outcome analysis. PMID:28380247

Validation of a method for in vivo 3D dose reconstruction for IMRT and VMAT treatments using on-treatment EPID images and a model-based forward-calculation algorithm

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

Van Uytven, Eric, E-mail: eric.vanuytven@cancercare.mb.ca; Van Beek, Timothy; McCowan, Peter M.

2015-12-15

Purpose: Radiation treatments are trending toward delivering higher doses per fraction under stereotactic radiosurgery and hypofractionated treatment regimens. There is a need for accurate 3D in vivo patient dose verification using electronic portal imaging device (EPID) measurements. This work presents a model-based technique to compute full three-dimensional patient dose reconstructed from on-treatment EPID portal images (i.e., transmission images). Methods: EPID dose is converted to incident fluence entering the patient using a series of steps which include converting measured EPID dose to fluence at the detector plane and then back-projecting the primary source component of the EPID fluence upstream of themore » patient. Incident fluence is then recombined with predicted extra-focal fluence and used to calculate 3D patient dose via a collapsed-cone convolution method. This method is implemented in an iterative manner, although in practice it provides accurate results in a single iteration. The robustness of the dose reconstruction technique is demonstrated with several simple slab phantom and nine anthropomorphic phantom cases. Prostate, head and neck, and lung treatments are all included as well as a range of delivery techniques including VMAT and dynamic intensity modulated radiation therapy (IMRT). Results: Results indicate that the patient dose reconstruction algorithm compares well with treatment planning system computed doses for controlled test situations. For simple phantom and square field tests, agreement was excellent with a 2%/2 mm 3D chi pass rate ≥98.9%. On anthropomorphic phantoms, the 2%/2 mm 3D chi pass rates ranged from 79.9% to 99.9% in the planning target volume (PTV) region and 96.5% to 100% in the low dose region (>20% of prescription, excluding PTV and skin build-up region). Conclusions: An algorithm to reconstruct delivered patient 3D doses from EPID exit dosimetry measurements was presented. The method was applied to phantom and patient data sets, as well as for dynamic IMRT and VMAT delivery techniques. Results indicate that the EPID dose reconstruction algorithm presented in this work is suitable for clinical implementation.« less

Cytotoxic triterpene diglycosides from the sea cucumber Stichopus horrens.

PubMed

Cuong, Nguyen Xuan; Vien, Le Thi; Hoang, Le; Hanh, Tran Thi Hong; Thao, Do Thi; Thanh, Nguyen Van; Nam, Nguyen Hoai; Thung, Do Cong; Kiem, Phan Van; Minh, Chau Van

2017-07-01

Using various chromatographic separation techniques, eight triterpene diglycosides (1-8), including four new compounds namely stichorrenosides A-D (1-4), were isolated from a methanol extract of the Vietnamese sea cucumber S. horrens. Their structures were elucidated based on spectroscopic analyses, including HR ESI MS, 1D and 2D NMR. Their in vitro cytotoxic activity against five human cancer cell lines, Hep-G2 (hepatoma cancer), KB (epidermoid carcinoma), LNCaP (prostate cancer), MCF7 (breast cancer), and SK-Mel2 (melanoma), was evaluated using SRB methods. Stichorrenoside D (4), stichoposide A (5), and 3β-O-[β-d-xylopyranosyl-(1→2)-β-d-xylopyranosyl]-23S-acetoxyholost-7-ene (7) showed strong cytotoxicity on all five tested cancer cell lines, whereas significant effect was observed for stichorrenoside C (3) and stichoposide B (6). Copyright © 2017 Elsevier Ltd. All rights reserved.

3D matching techniques using OCT fingerprint point clouds

NASA Astrophysics Data System (ADS)

Gutierrez da Costa, Henrique S.; Silva, Luciano; Bellon, Olga R. P.; Bowden, Audrey K.; Czovny, Raphael K.

2017-02-01

Optical Coherence Tomography (OCT) makes viable acquisition of 3D fingerprints from both dermis and epidermis skin layers and their interfaces, exposing features that can be explored to improve biometric identification such as the curvatures and distinctive 3D regions. Scanned images from eleven volunteers allowed the construction of the first OCT 3D fingerprint database, to our knowledge, containing epidermal and dermal fingerprints. 3D dermal fingerprints can be used to overcome cases of Failure to Enroll (FTE) due to poor ridge image quality and skin alterations, cases that affect 2D matching performance. We evaluate three matching techniques, including the well-established Iterative Closest Points algorithm (ICP), Surface Interpenetration Measure (SIM) and the well-known KH Curvature Maps, all assessed using a 3D OCT fingerprint database, the first one for this purpose. Two of these techniques are based on registration techniques and one on curvatures. These were evaluated, compared and the fusion of matching scores assessed. We applied a sequence of steps to extract regions of interest named (ROI) minutiae clouds, representing small regions around distinctive minutia, usually located at ridges/valleys endings or bifurcations. The obtained ROI is acquired from the epidermis and dermis-epidermis interface by OCT imaging. A comparative analysis of identification accuracy was explored using different scenarios and the obtained results shows improvements for biometric identification. A comparison against 2D fingerprint matching algorithms is also presented to assess the improvements.

Comparison of Different Magnetic Resonance Cholangiography Techniques in Living Liver Donors Including Gd-EOB-DTPA Enhanced T1-Weighted Sequences

PubMed Central

Kinner, Sonja; Steinweg, Verena; Maderwald, Stefan; Radtke, Arnold; Sotiropoulos, Georgios; Forsting, Michael; Schroeder, Tobias

2014-01-01

Objectives Preoperative evaluation of potential living liver donors (PLLDs) includes the assessment of the biliary anatomy to avoid postoperative complications. Aim of this study was to compare T2-weighted (T2w) and Gd-EOB-DTPA enhanced T1-weighted (T1w) magnetic resonance cholangiography (MRC) techniques in the evaluation of PLLDs. Materials and Methods 30 PLLDs underwent MRC on a 1.5 T Magnetom Avanto (Siemens, Erlangen, Germany) using (A) 2D T2w HASTE (Half Fourier Acquisition Single Shot Turbo Spin Echo) fat saturated (fs) in axial plane, (B) 2D T2w HASTE fs thick slices in coronal plane, (C) free breathing 3D T2w TSE (turbo spin echo) RESTORE (high-resolution navigator corrected) plus (D) maximum intensity projections (MIPs), (E) T2w SPACE (sampling perfection with application optimized contrasts using different flip angle evolutions) plus (F) MIPs and (G) T2w TSE BLADE as well as Gd-EOB-DTPA T1w images without (G) and with (H) inversion recovery. Contrast enhanced CT cholangiography served as reference imaging modality. Two independent reviewers evaluated the biliary tract anatomy on a 5-point scale subjectively and objectively. Data sets were compared using a Mann-Whitney-U-test. Kappa values were also calculated. Results Source images and maximum intensity projections of 3D T2w TSE sequences (RESTORE and SPACE) proved to be best for subjective and objective evaluation directly followed by 2D HASTE sequences. Interobserver variabilities were good to excellent (k = 0.622–0.804). Conclusions 3D T2w sequences are essential for preoperative biliary tract evaluation in potential living liver donors. Furthermore, our results underline the value of different MRCP sequence types for the evaluation of the biliary anatomy in PLLDs including Gd-EOB-DTPA enhanced T1w MRC. PMID:25426932

Subnuclear foci quantification using high-throughput 3D image cytometry

NASA Astrophysics Data System (ADS)

Wadduwage, Dushan N.; Parrish, Marcus; Choi, Heejin; Engelward, Bevin P.; Matsudaira, Paul; So, Peter T. C.

2015-07-01

Ionising radiation causes various types of DNA damages including double strand breaks (DSBs). DSBs are often recognized by DNA repair protein ATM which forms gamma-H2AX foci at the site of the DSBs that can be visualized using immunohistochemistry. However most of such experiments are of low throughput in terms of imaging and image analysis techniques. Most of the studies still use manual counting or classification. Hence they are limited to counting a low number of foci per cell (5 foci per nucleus) as the quantification process is extremely labour intensive. Therefore we have developed a high throughput instrumentation and computational pipeline specialized for gamma-H2AX foci quantification. A population of cells with highly clustered foci inside nuclei were imaged, in 3D with submicron resolution, using an in-house developed high throughput image cytometer. Imaging speeds as high as 800 cells/second in 3D were achieved by using HiLo wide-field depth resolved imaging and a remote z-scanning technique. Then the number of foci per cell nucleus were quantified using a 3D extended maxima transform based algorithm. Our results suggests that while most of the other 2D imaging and manual quantification studies can count only up to about 5 foci per nucleus our method is capable of counting more than 100. Moreover we show that 3D analysis is significantly superior compared to the 2D techniques.

Design Application Translates 2-D Graphics to 3-D Surfaces

NASA Technical Reports Server (NTRS)

2007-01-01

Fabric Images Inc., specializing in the printing and manufacturing of fabric tension architecture for the retail, museum, and exhibit/tradeshow communities, designed software to translate 2-D graphics for 3-D surfaces prior to print production. Fabric Images' fabric-flattening design process models a 3-D surface based on computer-aided design (CAD) specifications. The surface geometry of the model is used to form a 2-D template, similar to a flattening process developed by NASA's Glenn Research Center. This template or pattern is then applied in the development of a 2-D graphic layout. Benefits of this process include 11.5 percent time savings per project, less material wasted, and the ability to improve upon graphic techniques and offer new design services. Partners include Exhibitgroup/Giltspur (end-user client: TAC Air, a division of Truman Arnold Companies Inc.), Jack Morton Worldwide (end-user client: Nickelodeon), as well as 3D Exhibits Inc., and MG Design Associates Corp.

A technique for estimating 4D-CBCT using prior knowledge and limited-angle projections.

PubMed

Zhang, You; Yin, Fang-Fang; Segars, W Paul; Ren, Lei

2013-12-01

To develop a technique to estimate onboard 4D-CBCT using prior information and limited-angle projections for potential 4D target verification of lung radiotherapy. Each phase of onboard 4D-CBCT is considered as a deformation from one selected phase (prior volume) of the planning 4D-CT. The deformation field maps (DFMs) are solved using a motion modeling and free-form deformation (MM-FD) technique. In the MM-FD technique, the DFMs are estimated using a motion model which is extracted from planning 4D-CT based on principal component analysis (PCA). The motion model parameters are optimized by matching the digitally reconstructed radiographs of the deformed volumes to the limited-angle onboard projections (data fidelity constraint). Afterward, the estimated DFMs are fine-tuned using a FD model based on data fidelity constraint and deformation energy minimization. The 4D digital extended-cardiac-torso phantom was used to evaluate the MM-FD technique. A lung patient with a 30 mm diameter lesion was simulated with various anatomical and respirational changes from planning 4D-CT to onboard volume, including changes of respiration amplitude, lesion size and lesion average-position, and phase shift between lesion and body respiratory cycle. The lesions were contoured in both the estimated and "ground-truth" onboard 4D-CBCT for comparison. 3D volume percentage-difference (VPD) and center-of-mass shift (COMS) were calculated to evaluate the estimation accuracy of three techniques: MM-FD, MM-only, and FD-only. Different onboard projection acquisition scenarios and projection noise levels were simulated to investigate their effects on the estimation accuracy. For all simulated patient and projection acquisition scenarios, the mean VPD (±S.D.)∕COMS (±S.D.) between lesions in prior images and "ground-truth" onboard images were 136.11% (±42.76%)∕15.5 mm (±3.9 mm). Using orthogonal-view 15°-each scan angle, the mean VPD∕COMS between the lesion in estimated and "ground-truth" onboard images for MM-only, FD-only, and MM-FD techniques were 60.10% (±27.17%)∕4.9 mm (±3.0 mm), 96.07% (±31.48%)∕12.1 mm (±3.9 mm) and 11.45% (±9.37%)∕1.3 mm (±1.3 mm), respectively. For orthogonal-view 30°-each scan angle, the corresponding results were 59.16% (±26.66%)∕4.9 mm (±3.0 mm), 75.98% (±27.21%)∕9.9 mm (±4.0 mm), and 5.22% (±2.12%)∕0.5 mm (±0.4 mm). For single-view scan angles of 3°, 30°, and 60°, the results for MM-FD technique were 32.77% (±17.87%)∕3.2 mm (±2.2 mm), 24.57% (±18.18%)∕2.9 mm (±2.0 mm), and 10.48% (±9.50%)∕1.1 mm (±1.3 mm), respectively. For projection angular-sampling-intervals of 0.6°, 1.2°, and 2.5° with the orthogonal-view 30°-each scan angle, the MM-FD technique generated similar VPD (maximum deviation 2.91%) and COMS (maximum deviation 0.6 mm), while sparser sampling yielded larger VPD∕COMS. With equal number of projections, the estimation results using scattered 360° scan angle were slightly better than those using orthogonal-view 30°-each scan angle. The estimation accuracy of MM-FD technique declined as noise level increased. The MM-FD technique substantially improves the estimation accuracy for onboard 4D-CBCT using prior planning 4D-CT and limited-angle projections, compared to the MM-only and FD-only techniques. It can potentially be used for the inter/intrafractional 4D-localization verification.

A technique for estimating 4D-CBCT using prior knowledge and limited-angle projections

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

Zhang, You; Yin, Fang-Fang; Ren, Lei

2013-12-15

Purpose: To develop a technique to estimate onboard 4D-CBCT using prior information and limited-angle projections for potential 4D target verification of lung radiotherapy.Methods: Each phase of onboard 4D-CBCT is considered as a deformation from one selected phase (prior volume) of the planning 4D-CT. The deformation field maps (DFMs) are solved using a motion modeling and free-form deformation (MM-FD) technique. In the MM-FD technique, the DFMs are estimated using a motion model which is extracted from planning 4D-CT based on principal component analysis (PCA). The motion model parameters are optimized by matching the digitally reconstructed radiographs of the deformed volumes tomore » the limited-angle onboard projections (data fidelity constraint). Afterward, the estimated DFMs are fine-tuned using a FD model based on data fidelity constraint and deformation energy minimization. The 4D digital extended-cardiac-torso phantom was used to evaluate the MM-FD technique. A lung patient with a 30 mm diameter lesion was simulated with various anatomical and respirational changes from planning 4D-CT to onboard volume, including changes of respiration amplitude, lesion size and lesion average-position, and phase shift between lesion and body respiratory cycle. The lesions were contoured in both the estimated and “ground-truth” onboard 4D-CBCT for comparison. 3D volume percentage-difference (VPD) and center-of-mass shift (COMS) were calculated to evaluate the estimation accuracy of three techniques: MM-FD, MM-only, and FD-only. Different onboard projection acquisition scenarios and projection noise levels were simulated to investigate their effects on the estimation accuracy.Results: For all simulated patient and projection acquisition scenarios, the mean VPD (±S.D.)/COMS (±S.D.) between lesions in prior images and “ground-truth” onboard images were 136.11% (±42.76%)/15.5 mm (±3.9 mm). Using orthogonal-view 15°-each scan angle, the mean VPD/COMS between the lesion in estimated and “ground-truth” onboard images for MM-only, FD-only, and MM-FD techniques were 60.10% (±27.17%)/4.9 mm (±3.0 mm), 96.07% (±31.48%)/12.1 mm (±3.9 mm) and 11.45% (±9.37%)/1.3 mm (±1.3 mm), respectively. For orthogonal-view 30°-each scan angle, the corresponding results were 59.16% (±26.66%)/4.9 mm (±3.0 mm), 75.98% (±27.21%)/9.9 mm (±4.0 mm), and 5.22% (±2.12%)/0.5 mm (±0.4 mm). For single-view scan angles of 3°, 30°, and 60°, the results for MM-FD technique were 32.77% (±17.87%)/3.2 mm (±2.2 mm), 24.57% (±18.18%)/2.9 mm (±2.0 mm), and 10.48% (±9.50%)/1.1 mm (±1.3 mm), respectively. For projection angular-sampling-intervals of 0.6°, 1.2°, and 2.5° with the orthogonal-view 30°-each scan angle, the MM-FD technique generated similar VPD (maximum deviation 2.91%) and COMS (maximum deviation 0.6 mm), while sparser sampling yielded larger VPD/COMS. With equal number of projections, the estimation results using scattered 360° scan angle were slightly better than those using orthogonal-view 30°-each scan angle. The estimation accuracy of MM-FD technique declined as noise level increased.Conclusions: The MM-FD technique substantially improves the estimation accuracy for onboard 4D-CBCT using prior planning 4D-CT and limited-angle projections, compared to the MM-only and FD-only techniques. It can potentially be used for the inter/intrafractional 4D-localization verification.« less

Counting cell number in situ by quantification of dimethyl sulphide in culture headspace.

PubMed

Chippendale, Thomas W E; Španěl, Patrik; Smith, David; El Haj, Alicia J

2014-10-07

A novel, non-invasive technique is reported for determining the numbers of cells in a culture by quantifying dimethyl sulphide (DMS) in the culture headspace as produced by the cellular enzymatic reduction of dissolved dimethyl sulphoxide (DMSO). Measured DMS concentrations, as performed using selected ion flow tube mass spectrometry (SIFT-MS), in the headspace of 2D and 3D cultures of four cell lines, viz. HEK293 (kidney), MG63 (bone), hepG2 (liver) and CALU-1 (lung), linearly correlate with starting cell number. Clear differences in the rates of production of DMS by the four cell types in both the 2D and 3D situations are seen. This novel analytical technique for cell enumeration offers a significant contribution to quality assessment across cell-based research and industry, including analysis of large scale culture systems, and for routine cell biology research.

Synthesis, crystal structure and investigation of mononuclear copper(II) and zinc(II) complexes of a new carboxylate rich tripodal ligand and their interaction with carbohydrates in alkaline aqueous solution

PubMed Central

Stewart, Christopher D.; Pedraza, Mayra; Arman, Hadi; Fan, Hua-Jun; Schilling, Eduardo Luiz; Szpoganicz, Bruno; Musie, Ghezai T.

2016-01-01

A new carboxylate rich asymmetric tripodal ligand, N-[2-carboxybenzomethyl]-N-[carboxymethyl]-β-alanine (H3camb), and its di-copper(II), (NH4)2[1]2, and di-zinc(II), ((CH3)4 N)2[2]2, complexes have been synthesized as carbohydrate binding models in aqueous solutions. The ligand and complexes have been fully characterized using several techniques, including single crystal X-ray diffraction. The interactions of (NH4)2[1]2 and ((CH3)4 N)2[2]2 with D-glucose, D-mannose, D-xylose and xylitol in aqueous alkaline media were investigated using UV–Vis and 13C-NMR spectroscopic techniques, respectively. The molar conductance, NMR and ESI–MS studies indicate that the complexes dissociate in solution to produce the respective complex anions, 1− and 2−. Complexes 1− and 2− showed chelating ability towards the naturally abundant and biologically relevant sugars, D-glucose, D-mannose, D-xylose, and xylitol. The complex ions bind to one molar equivalent of the sugars, even in the presence of stoichiometric excess of the substrates, in solution. Experimentally obtained spectroscopic data and computational results suggest that the substrates bind to the metal center in a bidentate fashion. Apparent binding constant values, pKapp, between the complexes and the substrates were determined and a specific mode of substrate binding is proposed. The pKapp and relativistic density functional theory (DFT) calculated Gibbs free energy values indicate that D-mannose displayed the strongest interaction with the complexes. Syntheses, characterizations, detailed substrate binding studies using spectroscopic techniques, single crystal X-ray diffraction and geometry optimizations of the complex-substrates with DFT calculations are also reported. PMID:25969174

Building a Competitive Edge with Additive Manufacturing

DTIC Science & Technology

2013-02-14

construct ceramic molds for complex metal parts using a 3D printing technique. They estimate the new 6 technique could eliminate all of the...processes. They include 3D printing and Additive Beam Techniques.15 Most Additive Manufacturing techniques are specific to certain classes of materials...9 Example Additive Manufacturing Techniques16 3D Printing Additive Beam Stereolithography (SLA) Direct Metal Laser Sintering (DMLS

State of the "art": a taxonomy of artistic stylization techniques for images and video.

PubMed

Kyprianidis, Jan Eric; Collomosse, John; Wang, Tinghuai; Isenberg, Tobias

2013-05-01

This paper surveys the field of nonphotorealistic rendering (NPR), focusing on techniques for transforming 2D input (images and video) into artistically stylized renderings. We first present a taxonomy of the 2D NPR algorithms developed over the past two decades, structured according to the design characteristics and behavior of each technique. We then describe a chronology of development from the semiautomatic paint systems of the early nineties, through to the automated painterly rendering systems of the late nineties driven by image gradient analysis. Two complementary trends in the NPR literature are then addressed, with reference to our taxonomy. First, the fusion of higher level computer vision and NPR, illustrating the trends toward scene analysis to drive artistic abstraction and diversity of style. Second, the evolution of local processing approaches toward edge-aware filtering for real-time stylization of images and video. The survey then concludes with a discussion of open challenges for 2D NPR identified in recent NPR symposia, including topics such as user and aesthetic evaluation.

Low-Cost 3D Printing Orbital Implant Templates in Secondary Orbital Reconstructions.

PubMed

Callahan, Alison B; Campbell, Ashley A; Petris, Carisa; Kazim, Michael

Despite its increasing use in craniofacial reconstructions, three-dimensional (3D) printing of customized orbital implants has not been widely adopted. Limitations include the cost of 3D printers able to print in a biocompatible material suitable for implantation in the orbit and the breadth of available implant materials. The authors report the technique of low-cost 3D printing of orbital implant templates used in complex, often secondary, orbital reconstructions. A retrospective case series of 5 orbital reconstructions utilizing a technique of 3D printed orbital implant templates is presented. Each patient's Digital Imaging and Communications in Medicine data were uploaded and processed to create 3D renderings upon which a customized implant was designed and sent electronically to printers open for student use at our affiliated institutions. The mock implants were sterilized and used intraoperatively as a stencil and mold. The final implant material was chosen by the surgeons based on the requirements of the case. Five orbital reconstructions were performed with this technique: 3 tumor reconstructions and 2 orbital fractures. Four of the 5 cases were secondary reconstructions. Molded Medpor Titan (Stryker, Kalamazoo, MI) implants were used in 4 cases and titanium mesh in 1 case. The stenciled and molded implants were adjusted no more than 2 times before anchored in place (mean 1). No case underwent further revision. The technique and cases presented demonstrate 1) the feasibility and accessibility of low-cost, independent use of 3D printing technology to fashion patient-specific implants in orbital reconstructions, 2) the ability to apply this technology to the surgeon's preference of any routinely implantable material, and 3) the utility of this technique in complex, secondary reconstructions.

Quantification of left ventricular functional parameter values using 3D spiral bSSFP and through-time non-Cartesian GRAPPA.

PubMed

Barkauskas, Kestutis J; Rajiah, Prabhakar; Ashwath, Ravi; Hamilton, Jesse I; Chen, Yong; Ma, Dan; Wright, Katherine L; Gulani, Vikas; Griswold, Mark A; Seiberlich, Nicole

2014-09-11

The standard clinical acquisition for left ventricular functional parameter analysis with cardiovascular magnetic resonance (CMR) uses a multi-breathhold multi-slice segmented balanced SSFP sequence. Performing multiple long breathholds in quick succession for ventricular coverage in the short-axis orientation can lead to fatigue and is challenging in patients with severe cardiac or respiratory disorders. This study combines the encoding efficiency of a six-fold undersampled 3D stack of spirals balanced SSFP sequence with 3D through-time spiral GRAPPA parallel imaging reconstruction. This 3D spiral method requires only one breathhold to collect the dynamic data. Ten healthy volunteers were recruited for imaging at 3 T. The 3D spiral technique was compared against 2D imaging in terms of systolic left ventricular functional parameter values (Bland-Altman plots), total scan time (Welch's t-test) and qualitative image rating scores (Wilcoxon signed-rank test). Systolic left ventricular functional values were not significantly different (i.e. 3D-2D) between the methods. The 95% confidence interval for ejection fraction was -0.1 ± 1.6% (mean ± 1.96*SD). The total scan time for the 3D spiral technique was 48 s, which included one breathhold with an average duration of 14 s for the dynamic scan, plus 34 s to collect the calibration data under free-breathing conditions. The 2D method required an average of 5 min 40s for the same coverage of the left ventricle. The difference between 3D and 2D image rating scores was significantly different from zero (Wilcoxon signed-rank test, p < 0.05); however, the scores were at least 3 (i.e. average) or higher for 3D spiral imaging. The 3D through-time spiral GRAPPA method demonstrated equivalent systolic left ventricular functional parameter values, required significantly less total scan time and yielded acceptable image quality with respect to the 2D segmented multi-breathhold standard in this study. Moreover, the 3D spiral technique used just one breathhold for dynamic imaging, which is anticipated to reduce patient fatigue as part of the complete cardiac examination in future studies that include patients.

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

Harmon, S; Jeraj, R; Galavis, P

Purpose: Sensitivity of PET-derived texture features to reconstruction methods has been reported for features extracted from axial planes; however, studies often utilize three dimensional techniques. This work aims to quantify the impact of multi-plane (3D) vs. single-plane (2D) feature extraction on radiomics-based analysis, including sensitivity to reconstruction parameters and potential loss of spatial information. Methods: Twenty-three patients with solid tumors underwent [{sup 18}F]FDG PET/CT scans under identical protocols. PET data were reconstructed using five sets of reconstruction parameters. Tumors were segmented using an automatic, in-house algorithm robust to reconstruction variations. 50 texture features were extracted using two Methods: 2D patchesmore » along axial planes and 3D patches. For each method, sensitivity of features to reconstruction parameters was calculated as percent difference relative to the average value across reconstructions. Correlations between feature values were compared when using 2D and 3D extraction. Results: 21/50 features showed significantly different sensitivity to reconstruction parameters when extracted in 2D vs 3D (wilcoxon α<0.05), assessed by overall range of variation, Rangevar(%). Eleven showed greater sensitivity to reconstruction in 2D extraction, primarily first-order and co-occurrence features (average Rangevar increase 83%). The remaining ten showed higher variation in 3D extraction (average Range{sub var}increase 27%), mainly co-occurence and greylevel run-length features. Correlation of feature value extracted in 2D and feature value extracted in 3D was poor (R<0.5) in 12/50 features, including eight co-occurrence features. Feature-to-feature correlations in 2D were marginally higher than 3D, ∣R∣>0.8 in 16% and 13% of all feature combinations, respectively. Larger sensitivity to reconstruction parameters were seen for inter-feature correlation in 2D(σ=6%) than 3D (σ<1%) extraction. Conclusion: Sensitivity and correlation of various texture features were shown to significantly differ between 2D and 3D extraction. Additionally, inter-feature correlations were more sensitive to reconstruction variation using single-plane extraction. This work highlights a need for standardized feature extraction/selection techniques in radiomics.« less

PIV Measurement of Transient 3-D (Liquid and Gas Phases) Flow Structures Created by a Spreading Flame over 1-Propanol

NASA Technical Reports Server (NTRS)

Hassan, M. I.; Kuwana, K.; Saito, K.

2001-01-01

In the past, we measured three-D flow structure in the liquid and gas phases that were created by a spreading flame over liquid fuels. In that effort, we employed several different techniques including our original laser sheet particle tracking (LSPT) technique, which is capable of measuring transient 2-D flow structures. Recently we obtained a state-of-the-art integrated particle image velocimetry (IPIV), whose function is similar to LSPT, but it has an integrated data recording and processing system. To evaluate the accuracy of our IPIV system, we conducted a series of flame spread tests using the same experimental apparatus that we used in our previous flame spread studies and obtained a series of 2-D flow profiles corresponding to our previous LSPT measurements. We confirmed that both LSPT and IPIV techniques produced similar data, but IPIV data contains more detailed flow structures than LSPT data. Here we present some of newly obtained IPIV flow structure data, and discuss the role of gravity in the flame-induced flow structures. Note that the application of IPIV to our flame spread problems is not straightforward, and it required several preliminary tests for its accuracy including this IPIV comparison to LSPT.

Experimental Investigation of the Near Wall Flow Structure of a Low Reynolds Number 3-D Turbulent Boundary Layer

NASA Technical Reports Server (NTRS)

Fleming, J. L.; Simpson, R. L.

1997-01-01

Laser Doppler velocimetry (LDV) measurements and hydrogen bubble flow visualization techniques were used to examine the near-wall flow structure of 2D and 3D turbulent boundary layers (TBLs) over a range of low Reynolds numbers. The goals of this research were (1) an increased understanding of the flow physics in the near wall region of turbulent boundary layers,(2) to observe and quantify differences between 2D and 3D TBL flow structures, and (3) to document Reynolds number effects for 3D TBLs. The LDV data have provided results detailing the turbulence structure of the 2D and 3D TBLs. These results include mean Reynolds stress distributions, flow skewing results, and U and V spectra. Effects of Reynolds number for the 3D flow were also examined. Comparison to results with the same 3D flow geometry but at a significantly higher Reynolds number provided unique insight into the structure of 3D TBLs. While the 3D mean and fluctuating velocities were found to be highly dependent on Reynolds number, a previously defined shear stress parameter was discovered to be invariant with Reynolds number. The hydrogen bubble technique was used as a flow visualization tool to examine the near-wall flow structure of 2D and 3D TBLs. Both the quantitative and qualitative results displayed larger turbulent fluctuations with more highly concentrated vorticity regions for the 2D flow.

Characterization of novel preclinical dose distributions for micro irradiator

NASA Astrophysics Data System (ADS)

Kodra, J.; Miles, D.; Yoon, S. W.; Kirsch, D. G.; Oldham, M.

2017-05-01

This work explores and demonstrates the feasibility of utilizing new 3D printing techniques to implement advanced micro radiation therapy for pre-clinical small animal studies. 3D printed blocks and compensators were designed and printed from a strong x-ray attenuating material at sub-millimeter resolution. These techniques enable a powerful range of new preclinical treatment capabilities including grid therapy, lattice therapy, and IMRT treatment. At small scales, verification of these treatments is exceptionally challenging, and high resolution 3D dosimetry (0.5mm3) is an essential capability to characterize and verify these capabilities, Here, investigate the 2D and 3D dosimetry of several novel pre-clinical treatments using a combination of EBT film and Presage/optical-CT 3D dosimetry in rodent-morphic dosimeters.

High-resolution vascular tissue characterization in mice using 55MHz ultrasound hybrid imaging.

PubMed

Mahmoud, Ahmed M; Sandoval, Cesar; Teng, Bunyen; Schnermann, Jurgen B; Martin, Karen H; Mustafa, S Jamal; Mukdadi, Osama M

2013-03-01

Ultrasound and Duplex ultrasonography in particular are routinely used to diagnose cardiovascular disease (CVD), which is the leading cause of morbidity and mortality worldwide. However, these techniques may not be able to characterize vascular tissue compositional changes due to CVD. This work describes an ultrasound-based hybrid imaging technique that can be used for vascular tissue characterization and the diagnosis of atherosclerosis. Ultrasound radiofrequency (RF) data were acquired and processed in time, frequency, and wavelet domains to extract six parameters including time integrated backscatter (T(IB)), time variance (T(var)), time entropy (T(E)), frequency integrated backscatter (F(IB)), wavelet root mean square value (W(rms)), and wavelet integrated backscatter (W(IB)). Each parameter was used to reconstruct an image co-registered to morphological B-scan. The combined set of hybrid images were used to characterize vascular tissue in vitro and in vivo using three mouse models including control (C57BL/6), and atherosclerotic apolipoprotein E-knockout (APOE-KO) and APOE/A(1) adenosine receptor double knockout (DKO) mice. The technique was tested using high-frequency ultrasound including single-element (center frequency=55 MHz) and commercial array (center frequency=40 MHz) systems providing superior spatial resolutions of 24 μm and 40 μm, respectively. Atherosclerotic vascular lesions in the APOE-KO mouse exhibited the highest values (contrast) of -10.11±1.92 dB, -12.13±2.13 dB, -7.54±1.45 dB, -5.10±1.06 dB, -5.25±0.94 dB, and -10.23±2.12 dB in T(IB), T(var), T(E), F(IB), W(rms), W(IB) hybrid images (n=10, p<0.05), respectively. Control segments of normal vascular tissue showed the lowest values of -20.20±2.71 dB, -22.54±4.54 dB, -14.94±2.05 dB, -9.64±1.34 dB, -10.20±1.27 dB, and -19.36±3.24 dB in same hybrid images (n=6, p<0.05). Results from both histology and optical images showed good agreement with ultrasound findings within a maximum error of 3.6% in lesion estimation. This study demonstrated the feasibility of a high-resolution hybrid imaging technique to diagnose atherosclerosis and characterize plaque components in mouse. In the future, it can be easily implemented on commercial ultrasound systems and eventually translated into clinics as a screening tool for atherosclerosis and the assessment of vulnerable plaques. Copyright © 2012 Elsevier B.V. All rights reserved.

Direct EIT reconstructions of complex admittivities on a chest-shaped domain in 2-D.

PubMed

Hamilton, Sarah J; Mueller, Jennifer L

2013-04-01

Electrical impedance tomography (EIT) is a medical imaging technique in which current is applied on electrodes on the surface of the body, the resulting voltage is measured, and an inverse problem is solved to recover the conductivity and/or permittivity in the interior. Images are then formed from the reconstructed conductivity and permittivity distributions. In the 2-D geometry, EIT is clinically useful for chest imaging. In this work, an implementation of a D-bar method for complex admittivities on a general 2-D domain is presented. In particular, reconstructions are computed on a chest-shaped domain for several realistic phantoms including a simulated pneumothorax, hyperinflation, and pleural effusion. The method demonstrates robustness in the presence of noise. Reconstructions from trigonometric and pairwise current injection patterns are included.

2D Organic Materials for Optoelectronic Applications.

PubMed

Yang, Fangxu; Cheng, Shanshan; Zhang, Xiaotao; Ren, Xiaochen; Li, Rongjin; Dong, Huanli; Hu, Wenping

2018-01-01

The remarkable merits of 2D materials with atomically thin structures and optoelectronic attributes have inspired great interest in integrating 2D materials into electronics and optoelectronics. Moreover, as an emerging field in the 2D-materials family, assembly of organic nanostructures into 2D forms offers the advantages of molecular diversity, intrinsic flexibility, ease of processing, light weight, and so on, providing an exciting prospect for optoelectronic applications. Herein, the applications of organic 2D materials for optoelectronic devices are a main focus. Material examples include 2D, organic, crystalline, small molecules, polymers, self-assembly monolayers, and covalent organic frameworks. The protocols for 2D-organic-crystal-fabrication and -patterning techniques are briefly discussed, then applications in optoelectronic devices are introduced in detail. Overall, an introduction to what is known and suggestions for the potential of many exciting developments are presented. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Bridging the Gap: From 2D Cell Culture to 3D Microengineered Extracellular Matrices.

PubMed

Li, Yanfen; Kilian, Kristopher A

2015-12-30

Historically the culture of mammalian cells in the laboratory has been performed on planar substrates with media cocktails that are optimized to maintain phenotype. However, it is becoming increasingly clear that much of biology discerned from 2D studies does not translate well to the 3D microenvironment. Over the last several decades, 2D and 3D microengineering approaches have been developed that better recapitulate the complex architecture and properties of in vivo tissue. Inspired by the infrastructure of the microelectronics industry, lithographic patterning approaches have taken center stage because of the ease in which cell-sized features can be engineered on surfaces and within a broad range of biocompatible materials. Patterning and templating techniques enable precise control over extracellular matrix properties including: composition, mechanics, geometry, cell-cell contact, and diffusion. In this review article we explore how the field of engineered extracellular matrices has evolved with the development of new hydrogel chemistry and the maturation of micro- and nano- fabrication. Guided by the spatiotemporal regulation of cell state in developing tissues, techniques for micropatterning in 2D, pseudo-3D systems, and patterning within 3D hydrogels will be discussed in the context of translating the information gained from 2D systems to synthetic engineered 3D tissues. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A new withanolide glycoside from physalis peruviana

PubMed

Ahmad; Malik; Afza; Yasmin

1999-03-01

A new withanolide glycoside, 17beta-hydroxy-14, 20-epoxy-1-oxo-[22R]-3beta-[O-beta-D-glucopyranosyl]-witha-5, 24-dienolide (1), has been isolated from the whole plant of Physalis peruviana. Its identity was determined using a combination of spectroscopic data including 2D NMR techniques and chemical transformations.

A Biomechanical Modeling Guided CBCT Estimation Technique

PubMed Central

Zhang, You; Tehrani, Joubin Nasehi; Wang, Jing

2017-01-01

Two-dimensional-to-three-dimensional (2D-3D) deformation has emerged as a new technique to estimate cone-beam computed tomography (CBCT) images. The technique is based on deforming a prior high-quality 3D CT/CBCT image to form a new CBCT image, guided by limited-view 2D projections. The accuracy of this intensity-based technique, however, is often limited in low-contrast image regions with subtle intensity differences. The solved deformation vector fields (DVFs) can also be biomechanically unrealistic. To address these problems, we have developed a biomechanical modeling guided CBCT estimation technique (Bio-CBCT-est) by combining 2D-3D deformation with finite element analysis (FEA)-based biomechanical modeling of anatomical structures. Specifically, Bio-CBCT-est first extracts the 2D-3D deformation-generated displacement vectors at the high-contrast anatomical structure boundaries. The extracted surface deformation fields are subsequently used as the boundary conditions to drive structure-based FEA to correct and fine-tune the overall deformation fields, especially those at low-contrast regions within the structure. The resulting FEA-corrected deformation fields are then fed back into 2D-3D deformation to form an iterative loop, combining the benefits of intensity-based deformation and biomechanical modeling for CBCT estimation. Using eleven lung cancer patient cases, the accuracy of the Bio-CBCT-est technique has been compared to that of the 2D-3D deformation technique and the traditional CBCT reconstruction techniques. The accuracy was evaluated in the image domain, and also in the DVF domain through clinician-tracked lung landmarks. PMID:27831866

Combining NMR spectral and structural data to form models of polychlorinated dibenzodioxins, dibenzofurans, and biphenyls binding to the AhR

NASA Astrophysics Data System (ADS)

Beger, Richard D.; Buzatu, Dan A.; Wilkes, Jon G.

2002-10-01

A three-dimensional quantitative spectrometric data-activity relationship (3D-QSDAR) modeling technique which uses NMR spectral and structural information that is combined in a 3D-connectivity matrix has been developed. A 3D-connectivity matrix was built by displaying all possible assigned carbon NMR chemical shifts, carbon-to-carbon connections, and distances between the carbons. Two-dimensional 13C-13C COSY and 2D slices from the distance dimension of the 3D-connectivity matrix were used to produce a relationship among the 2D spectral patterns for polychlorinated dibenzofurans, dibenzodioxins, and biphenyls (PCDFs, PCDDs, and PCBs respectively) binding to the aryl hydrocarbon receptor (AhR). We refer to this technique as comparative structural connectivity spectral analysis (CoSCoSA) modeling. All CoSCoSA models were developed using forward multiple linear regression analysis of the predicted 13C NMR structure-connectivity spectral bins. A CoSCoSA model for 26 PCDFs had an explained variance (r2) of 0.93 and an average leave-four-out cross-validated variance (q4 2) of 0.89. A CoSCoSA model for 14 PCDDs produced an r2 of 0.90 and an average leave-two-out cross-validated variance (q2 2) of 0.79. One CoSCoSA model for 12 PCBs gave an r2 of 0.91 and an average q2 2 of 0.80. Another CoSCoSA model for all 52 compounds had an r2 of 0.85 and an average q4 2 of 0.52. Major benefits of CoSCoSA modeling include ease of development since the technique does not use molecular docking routines.

Assessment of normal tissue complications following prostate cancer irradiation: Comparison of radiation treatment modalities using NTCP models

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

Takam, Rungdham; Bezak, Eva; Yeoh, Eric E.

2010-09-15

Purpose: Normal tissue complication probability (NTCP) of the rectum, bladder, urethra, and femoral heads following several techniques for radiation treatment of prostate cancer were evaluated applying the relative seriality and Lyman models. Methods: Model parameters from literature were used in this evaluation. The treatment techniques included external (standard fractionated, hypofractionated, and dose-escalated) three-dimensional conformal radiotherapy (3D-CRT), low-dose-rate (LDR) brachytherapy (I-125 seeds), and high-dose-rate (HDR) brachytherapy (Ir-192 source). Dose-volume histograms (DVHs) of the rectum, bladder, and urethra retrieved from corresponding treatment planning systems were converted to biological effective dose-based and equivalent dose-based DVHs, respectively, in order to account for differences inmore » radiation treatment modality and fractionation schedule. Results: Results indicated that with hypofractionated 3D-CRT (20 fractions of 2.75 Gy/fraction delivered five times/week to total dose of 55 Gy), NTCP of the rectum, bladder, and urethra were less than those for standard fractionated 3D-CRT using a four-field technique (32 fractions of 2 Gy/fraction delivered five times/week to total dose of 64 Gy) and dose-escalated 3D-CRT. Rectal and bladder NTCPs (5.2% and 6.6%, respectively) following the dose-escalated four-field 3D-CRT (2 Gy/fraction to total dose of 74 Gy) were the highest among analyzed treatment techniques. The average NTCP for the rectum and urethra were 0.6% and 24.7% for LDR-BT and 0.5% and 11.2% for HDR-BT. Conclusions: Although brachytherapy techniques resulted in delivering larger equivalent doses to normal tissues, the corresponding NTCPs were lower than those of external beam techniques other than the urethra because of much smaller volumes irradiated to higher doses. Among analyzed normal tissues, the femoral heads were found to have the lowest probability of complications as most of their volume was irradiated to lower equivalent doses compared to other tissues.« less

Recent Experimental Results Related to Ejector Mode Studies of Rocket-Based Combined Cycle (RBCC) Engines

NASA Technical Reports Server (NTRS)

Cramer, J. M.; Pal, S.; Marshall, W. M.; Santoro, R. J.

2003-01-01

Contents include the folloving: 1. Motivation. Support NASA's 3d generation launch vehicle technology program. RBCC is promising candidate for 3d generation propulsion system. 2. Approach. Focus on ejector mode p3erformance (Mach 0-3). Perform testing on established flowpath geometry. Use conventional propulsion measurement techniques. Use advanced optical diagnostic techniques to measure local combustion gas properties. 3. Objectives. Gain physical understanding of detailing mixing and combustion phenomena. Establish an experimental data set for CFD code development and validation.

Imaging of oxygen and hypoxia in cell and tissue samples.

PubMed

Papkovsky, Dmitri B; Dmitriev, Ruslan I

2018-05-14

Molecular oxygen (O 2 ) is a key player in cell mitochondrial function, redox balance and oxidative stress, normal tissue function and many common disease states. Various chemical, physical and biological methods have been proposed for measurement, real-time monitoring and imaging of O 2 concentration, state of decreased O 2 (hypoxia) and related parameters in cells and tissue. Here, we review the established and emerging optical microscopy techniques allowing to visualize O 2 levels in cells and tissue samples, mostly under in vitro and ex vivo, but also under in vivo settings. Particular examples include fluorescent hypoxia stains, fluorescent protein reporter systems, phosphorescent probes and nanosensors of different types. These techniques allow high-resolution mapping of O 2 gradients in live or post-mortem tissue, in 2D or 3D, qualitatively or quantitatively. They enable control and monitoring of oxygenation conditions and their correlation with other biomarkers of cell and tissue function. Comparison of these techniques and corresponding imaging setups, their analytical capabilities and typical applications are given.

M-BAND analysis of chromosome aberration induced by Fe-ions in human epithelial cells cultured in 3-dimensional matrices

NASA Astrophysics Data System (ADS)

Hada, Megumi; Cucinotta, Francis A.; Wu, Honglu

Energetic heavy ions pose a great health risk to astronauts in extended ISS and future lunar and Mars missions. High-LET heavy ions are particularly effective in causing various biological effects, including cell inactivation, genetic mutations, cataracts and cancer induction. Most of these biological endpoints are closely related to chromosomal damage, which can be utilized as a biomarker for radiation insults. Previously, we had studied lowand high-LET radiationinduced chromosome aberrations in human epithelial cells cultured in 2-dimension (2D) using the multicolor banding fluorescence in situ hybridization (mBAND) technique. However, it has been realized that the biological response to radiation insult in a 2D cellular environment in vitro can differ significantly from the response in 3-dimension (3D) or at the actual tissue level. In this study, we cultured human epithelial cells in 3D to provide a more suitable model for human tissue. Human mammary epithelial cells (CH184B5F5/M10) were grown in Matrigel to form 3D structures, and exposed to Fe-ions at NASA Space Radiation Laboratory (NSRL) at the Brookhaven National Laboratory or 137 Cs-gamma radiation source at the University of Texas MD Anderson Cancer Center. After exposure, cells were allowed to repair for 16hr before dissociation and subcultured at low density in 2D. G2 and metaphase chromosomes in the first cell cycle were collected using a chemical-induced premature chromosome condensation (PCC) technique, and chromosome aberrations were analyzed using mBAND technique. With this technique, individually painted chromosomal bands on one chromosome allowed the identification of interchromosomal aberrations (translocation to unpainted chromosomes) and intrachromosomal aberrations (inversions and deletions within a single painted chromosome). Our data indicate a significant difference of the chromosome aberration yield between 2D and 3D cell cultures for gamma exposures, but not for Fe ion exposures. Therefore, the RBE for chromosome aberrations obtained in a 2D model may not represent accurately the RBE for tissues.

High- and low-LET Radiation-induced Chromosome Aberrations in Human Epithelial Cells Cultured in 3-dimensional Matrices

NASA Technical Reports Server (NTRS)

Hada, M.; George K.; Cucinotta, F. A.; Wu, H.

2008-01-01

Energetic heavy ions pose a great health risk to astronauts who participate in extended ISS missions and will be an even greater concern for future manned lunar and Mars missions. High-LET heavy ions are particularly effective in causing various biological effects, including cell inactivation, genetic mutations, cataracts and cancer induction. Most of these biological endpoints are closely related to chromosomal damage, which can be utilized as a biomarker for radiation insults. Previously, we had studied low- and high-LET radiation-induced chromosome aberrations in human epithelial cells cultured in 2-dimension (2D) using the multicolor banding fluorescence in situ hybridization (mBAND) technique. However, it has been realized that the biological response to radiation insult in a 2D in vitro cellular environment can differ significantly from the response in 3-dimension (3D) or at the actual tissue level. In this study, we cultured human epithelial cells in 3D to provide a more suitable model for human tissue. Human mammary epithelial cells (CH184B5F5/M10) were grown in Matrigel to form 3D structures, and exposed to Fe-ions at NASA Space Radiation Laboratory (NSRL) at the Brookhaven National Laboratory or 137Cs-gamma radiation source at the University of Texas MD Anderson Cancer Center. After exposure, cells were allowed to repair for 16hr before dissociation and subcultured at low density in 2D. G2 and metaphase chromosomes in the first cell cycle were collected in the first cell cycle after irradiation using a chemical-induced premature chromosome condensation (PCC) technique, and chromosome aberrations were analyzed using mBAND technique. With this technique, individually painted chromosomal bands on one chromosome allowed the identification of interchromosomal aberrations (translocation to unpainted chromosomes) and intrachromosomal aberrations (inversions and deletions within a single painted chromosome). Our data indicate a significant difference in the chromosome aberration yield between 2D and 3D cell cultures after gamma exposures, but not after Fe ion exposures. Therefore, the Relative Biological Effect (RBE) for induction of chromosome aberrations obtained in a 2D model may not accurately represent RBE values obtained for tissue exposure.

M-BAND Analysis of Chromosome Aberration Induced by Fe-Ions in Human Epithelial Cells Cultured in 3-Dimensional Matrices

NASA Technical Reports Server (NTRS)

Hada, M.; Cucinotta, F. A.; Wu, H.

2008-01-01

Energetic heavy ions pose a great health risk to astronauts in extended ISS and future lunar and Mars missions. High-LET heavy ions are particularly effective in causing various biological effects, including cell inactivation, genetic mutations, cataracts and cancer induction. Most of these biological endpoints are closely related to chromosomal damage, which can be utilized as a biomarker for radiation insults. Previously, we had studied low- and high-LET radiation-induced chromosome aberrations in human epithelial cells cultured in 2-dimension (2D) using the multicolor banding fluorescence in situ hybridization (mBAND) technique. However, it has been realized that the biological response to radiation insult in a 2D cellular environment in vitro can differ significantly from the response in 3-dimension (3D) or at the actual tissue level. In this study, we cultured human epithelial cells in 3D to provide a more suitable model for human tissue. Human mammary epithelia cells (CH184B5F5/M10) were grown in Matrigel to form 3D structures, and exposed to Fe-ions at NASA Space Radiation Laboratory (NSRL) at the Brookhaven National Laboratory or 137Cs-gamma radiation source at the University of Texas MD Anderson Cancer Center. After exposure, cells were allowed to repair for 16hr before dissociation and subcultued at low density in 2D. G2 and metaphase chromosomes in the first cell cycle were collected using a chemical-induced premature chromosome condensation (PCC) technique, and chromosome aberrations were analyzed using mBAND technique. With this technique, individually painted chromosomal bands on one chromosome allowed the identification of interchromosomal aberrations (translocation to unpainted chromosomes) and intrachromosomal aberrations (inversions and deletions within a single painted chromosome). Our data indicate a significant difference of the chromosome aberration yield between 2D and 3D cell cultures for gamma exposures, but not for Fe ion exposures. Therefore, the RBE for chromosome aberrations obtained in a 2D model may not represent accurately the RBE for tissues.

A high-resolution (13)C 3D CSA-CSA-CSA correlation experiment by means of magic angle turning.

PubMed

Hu, J Z; Ye, C; Pugmire, R J; Grant, D M

2000-08-01

It is shown in this paper that a previously reported 90 degrees sample flipping (13)C 2D CSA-CSA correlation experiment may be carried out alternatively by employing constant slow sample rotation about the magic angle axis and by synchronizing the read pulse to 13 of the rotor cycle. A high-resolution 3D CSA-CSA-CSA correlation experiment based on the magic angle turning technique is reported in which the conventional 90 degrees 2D CSA-CSA powder pattern for each carbon in a system containing a number of inequivalent carbons may be separated according to the isotropic chemical shift value. The technique is demonstrated on 1,2,3-trimethoxybenzene in which all of the overlapping powder patterns that cannot be segregated by the 2D CSA-CSA experiment are resolved successfully by the 3D CSA-CSA-CSA experiment, including even the two methoxy groups (M(1) and M(3)) whose isotropic shifts, confirmed by high-speed MAS, are separated by only 1 ppm. A difference of 4 ppm in the principal value component (delta(33)) between M(1) and M(3) is readily obtained. Copyright 2000 Academic Press.

Architecture for high performance stereoscopic game rendering on Android

NASA Astrophysics Data System (ADS)

Flack, Julien; Sanderson, Hugh; Shetty, Sampath

2014-03-01

Stereoscopic gaming is a popular source of content for consumer 3D display systems. There has been a significant shift in the gaming industry towards casual games for mobile devices running on the Android™ Operating System and driven by ARM™ and other low power processors. Such systems are now being integrated directly into the next generation of 3D TVs potentially removing the requirement for an external games console. Although native stereo support has been integrated into some high profile titles on established platforms like Windows PC and PS3 there is a lack of GPU independent 3D support for the emerging Android platform. We describe a framework for enabling stereoscopic 3D gaming on Android for applications on mobile devices, set top boxes and TVs. A core component of the architecture is a 3D game driver, which is integrated into the Android OpenGL™ ES graphics stack to convert existing 2D graphics applications into stereoscopic 3D in real-time. The architecture includes a method of analyzing 2D games and using rule based Artificial Intelligence (AI) to position separate objects in 3D space. We describe an innovative stereo 3D rendering technique to separate the views in the depth domain and render directly into the display buffer. The advantages of the stereo renderer are demonstrated by characterizing the performance in comparison to more traditional render techniques, including depth based image rendering, both in terms of frame rates and impact on battery consumption.

Two-dimensional correlation spectroscopy — Biannual survey 2007-2009

NASA Astrophysics Data System (ADS)

Noda, Isao

2010-06-01

The publication activities in the field of 2D correlation spectroscopy are surveyed with the emphasis on papers published during the last two years. Pertinent review articles and conference proceedings are discussed first, followed by the examination of noteworthy developments in the theory and applications of 2D correlation spectroscopy. Specific topics of interest include Pareto scaling, analysis of randomly sampled spectra, 2D analysis of data obtained under multiple perturbations, evolution of 2D spectra along additional variables, comparison and quantitative analysis of multiple 2D spectra, orthogonal sample design to eliminate interfering cross peaks, quadrature orthogonal signal correction and other data transformation techniques, data pretreatment methods, moving window analysis, extension of kernel and global phase angle analysis, covariance and correlation coefficient mapping, variant forms of sample-sample correlation, and different display methods. Various static and dynamic perturbation methods used in 2D correlation spectroscopy, e.g., temperature, composition, chemical reactions, H/D exchange, physical phenomena like sorption, diffusion and phase transitions, optical and biological processes, are reviewed. Analytical probes used in 2D correlation spectroscopy include IR, Raman, NIR, NMR, X-ray, mass spectrometry, chromatography, and others. Application areas of 2D correlation spectroscopy are diverse, encompassing synthetic and natural polymers, liquid crystals, proteins and peptides, biomaterials, pharmaceuticals, food and agricultural products, solutions, colloids, surfaces, and the like.

2D materials advances: from large scale synthesis and controlled heterostructures to improved characterization techniques, defects and applications

DOE PAGES

Lin, Zhong; McCreary, Amber; Briggs, Natalie; ...

2016-12-08

The rise of two-dimensional (2D) materials research took place following the isolation of graphene in 2004. These new 2D materials include transition metal dichalcogenides, mono-elemental 2D sheets, and several carbide- and nitride-based materials. The number of publications related to these emerging materials has been drastically increasing over the last five years. Thus, through this comprehensive review, we aim to discuss the most recent groundbreaking discoveries as well as emerging opportunities and remaining challenges. This review starts out by delving into the improved methods of producing these new 2D materials via controlled exfoliation, metal organic chemical vapor deposition, and wet chemicalmore » means. Here we look into recent studies of doping as well as the optical properties of 2D materials and their heterostructures. Recent advances towards applications of these materials in 2D electronics are also reviewed, and include the tunnel MOSFET and ways to reduce the contact resistance for fabricating high-quality devices. Finally, several unique and innovative applications recently explored are discussed as well as perspectives of this exciting and fast moving field.« less

Spatially resolved D-T(2) correlation NMR of porous media.

PubMed

Zhang, Yan; Blümich, Bernhard

2014-05-01

Within the past decade, 2D Laplace nuclear magnetic resonance (NMR) has been developed to analyze pore geometry and diffusion of fluids in porous media on the micrometer scale. Many objects like rocks and concrete are heterogeneous on the macroscopic scale, and an integral analysis of microscopic properties provides volume-averaged information. Magnetic resonance imaging (MRI) resolves this spatial average on the contrast scale set by the particular MRI technique. Desirable contrast parameters for studies of fluid transport in porous media derive from the pore-size distribution and the pore connectivity. These microscopic parameters are accessed by 1D and 2D Laplace NMR techniques. It is therefore desirable to combine MRI and 2D Laplace NMR to image functional information on fluid transport in porous media. Because 2D Laplace resolved MRI demands excessive measuring time, this study investigates the possibility to restrict the 2D Laplace analysis to the sum signals from low-resolution pixels, which correspond to pixels of similar amplitude in high-resolution images. In this exploratory study spatially resolved D-T2 correlation maps from glass beads and mortar are analyzed. Regions of similar contrast are first identified in high-resolution images to locate corresponding pixels in low-resolution images generated with D-T2 resolved MRI for subsequent pixel summation to improve the signal-to-noise ratio of contrast-specific D-T2 maps. This method is expected to contribute valuable information on correlated sample heterogeneity from the macroscopic and the microscopic scales in various types of porous materials including building materials and rock. Copyright © 2014 Elsevier Inc. All rights reserved.

From 3D to 2D: A Review of the Molecular Imprinting of Proteins

PubMed Central

Turner, Nicholas W.; Jeans, Christopher W.; Brain, Keith R.; Allender, Christopher J.; Hlady, Vladimir; Britt, David W.

2008-01-01

Molecular imprinting is a generic technology that allows for the introduction of sites of specific molecular affinity into otherwise homogeneous polymeric matrices. Commonly this technique has been shown to be effective when targeting small molecules of molecular weight <1500, while extending the technique to larger molecules such as proteins has proven difficult. A number of key inherent problems in protein imprinting have been identified, including permanent entrapment, poor mass transfer, denaturation, and heterogeneity in binding pocket affinity, which have been addressed using a variety of approaches. This review focuses on protein imprinting in its various forms, ranging from conventional bulk techniques to novel thin film and monolayer surface imprinting approaches. PMID:17137293

From 3D to 2D: a review of the molecular imprinting of proteins.

PubMed

Turner, Nicholas W; Jeans, Christopher W; Brain, Keith R; Allender, Christopher J; Hlady, Vladimir; Britt, David W

2006-01-01

Molecular imprinting is a generic technology that allows for the introduction of sites of specific molecular affinity into otherwise homogeneous polymeric matrices. Commonly this technique has been shown to be effective when targeting small molecules of molecular weight <1500, while extending the technique to larger molecules such as proteins has proven difficult. A number of key inherent problems in protein imprinting have been identified, including permanent entrapment, poor mass transfer, denaturation, and heterogeneity in binding pocket affinity, which have been addressed using a variety of approaches. This review focuses on protein imprinting in its various forms, ranging from conventional bulk techniques to novel thin film and monolayer surface imprinting approaches.

2-dimensional implicit hydrodynamics on adaptive grids

NASA Astrophysics Data System (ADS)

Stökl, A.; Dorfi, E. A.

2007-12-01

We present a numerical scheme for two-dimensional hydrodynamics computations using a 2D adaptive grid together with an implicit discretization. The combination of these techniques has offered favorable numerical properties applicable to a variety of one-dimensional astrophysical problems which motivated us to generalize this approach for two-dimensional applications. Due to the different topological nature of 2D grids compared to 1D problems, grid adaptivity has to avoid severe grid distortions which necessitates additional smoothing parameters to be included into the formulation of a 2D adaptive grid. The concept of adaptivity is described in detail and several test computations demonstrate the effectivity of smoothing. The coupled solution of this grid equation together with the equations of hydrodynamics is illustrated by computation of a 2D shock tube problem.

A review of 3D first-pass, whole-heart, myocardial perfusion cardiovascular magnetic resonance.

PubMed

Fair, Merlin J; Gatehouse, Peter D; DiBella, Edward V R; Firmin, David N

2015-08-01

A comprehensive review is undertaken of the methods available for 3D whole-heart first-pass perfusion (FPP) and their application to date, with particular focus on possible acceleration techniques. Following a summary of the parameters typically desired of 3D FPP methods, the review explains the mechanisms of key acceleration techniques and their potential use in FPP for attaining 3D acquisitions. The mechanisms include rapid sequences, non-Cartesian k-space trajectories, reduced k-space acquisitions, parallel imaging reconstructions and compressed sensing. An attempt is made to explain, rather than simply state, the varying methods with the hope that it will give an appreciation of the different components making up a 3D FPP protocol. Basic estimates demonstrating the required total acceleration factors in typical 3D FPP cases are included, providing context for the extent that each acceleration method can contribute to the required imaging speed, as well as potential limitations in present 3D FPP literature. Although many 3D FPP methods are too early in development for the type of clinical trials required to show any clear benefit over current 2D FPP methods, the review includes the small but growing quantity of clinical research work already using 3D FPP, alongside the more technical work. Broader challenges concerning FPP such as quantitative analysis are not covered, but challenges with particular impact on 3D FPP methods, particularly with regards to motion effects, are discussed along with anticipated future work in the field.

Understanding Magnetic Resonance Imaging of Knee Cartilage Repair: A Focus on Clinical Relevance.

PubMed

Hayashi, Daichi; Li, Xinning; Murakami, Akira M; Roemer, Frank W; Trattnig, Siegfried; Guermazi, Ali

2017-06-01

The aims of this review article are (a) to describe the principles of morphologic and compositional magnetic resonance imaging (MRI) techniques relevant for the imaging of knee cartilage repair surgery and their application to longitudinal studies and (b) to illustrate the clinical relevance of pre- and postsurgical MRI with correlation to intraoperative images. First, MRI sequences that can be applied for imaging of cartilage repair tissue in the knee are described, focusing on comparison of 2D and 3D fast spin echo and gradient recalled echo sequences. Imaging features of cartilage repair tissue are then discussed, including conventional (morphologic) MRI and compositional MRI techniques. More specifically, imaging techniques for specific cartilage repair surgery techniques as described above, as well as MRI-based semiquantitative scoring systems for the knee cartilage repair tissue-MR Observation of Cartilage Repair Tissue and Cartilage Repair OA Knee Score-are explained. Then, currently available surgical techniques are reviewed, including marrow stimulation, osteochondral autograft, osteochondral allograft, particulate cartilage allograft, autologous chondrocyte implantation, and others. Finally, ongoing research efforts and future direction of cartilage repair tissue imaging are discussed.

SU-F-BRE-07: Experimental Validation of a Lung SBRT Technique Using a Novel, True Volumetric Plenoptic-Plastic-Scintillator Detector

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

Goulet, M; Rilling, M; Gingras, L

2014-06-15

Purpose: Lung SBRT is being used by an increasing number of clinics, including our center which recently treated its first patient. In order to validate this technique, the 3D dose distribution of the SBRT plan was measured using a previously developed 3D detector based on plenoptic camera and plastic scintillator technology. The excellent agreement between the detector measurement and the expected dose from the treatment planning system Pinnacle{sup 3} shows great promise and amply justify the development of the technique. Methods: The SBRT treatment comprised 8 non-coplanar 6MV photon fields with a mean field size of 12 cm{sup 2} atmore » isocentre and a total prescription dose of 12Gy per fraction for a total of 48Gy. The 3D detector was composed of a 10×10×10 cm{sup 2} EJ-260 water-equivalent plastic scintillator embedded inside a truncated cylindrical acrylic phantom of 10cm radius. The scintillation light was recorded using a static R5 light-field camera and the 3D dose was reconstructed at a 2mm resolution in all 3 dimensions using an iterative backprojection algorithm. Results: The whole 3D dose distribution was recorded at a rate of one acquisition per second. The mean absolute dose difference between the detector and Pinnacle{sup 3} was 1.3% over the region with more than 10% of the maximum dose. 3D gamma tests performed over the same region yield passing rates of 98.8% and 96.6% with criteria of 3%/1mm and 2%/1mm, respectively. Conclusion: Experimental results showed that our beam modeling and treatment planning system calculation was adequate for the safe administration of small field/high dose techniques such as SBRT. Moreover, because of the real-time capability of the detector, further validation of small field rotational, dynamic or gated technique can be monitored or verified by this system.« less

Ophiamides A-B, new potent urease inhibitory sphingolipids from Heliotropium ophioglossum.

PubMed

Firdous, Sadiqa; Ansari, Nida Hassan; Fatima, Itrat; Malik, Abdul; Afza, Nighat; Iqbal, Lubna; Lateef, Mehreen

2012-07-01

Ophiamides A (1) and B (2), two new sphingolipids have been isolated from the n-hexane subfraction of the MeOH extract of the whole plant of Heliotropium ophioglossum along with glycerol monopalmitate (3) and β-sitosterol 3-O-β-D: -glucoside (4) reported for the first time from this species. Their structures were elucidated by spectroscopic techniques including MS and 2D-NMR spectroscopy. Both the compounds 1 and 2 showed potent inhibitory activity against the enzyme urease.

SU-E-T-433: Field-In-Field Irradiation for Breast Cancer with VERO-4DRT System: A Feasibility Study

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

Hayashi, N; Mizuno, T; Takada, Y

2015-06-15

Purpose: The Vero-4DRT system is a dedicated system for high precision radiation therapy. However, the field size is limited at 15 cm x 15 cm and shapes by using multi-leaf collimator (MLC) without X-Jaw and Y-Jaw. Therefore VERO-4DRT system is not available to simple wedged irradiation for breast cancer. In this study, we suppose FIF with ring and/or tilt/pan angles whole breast irradiation (FIFWBI). The purpose of this study is to verify the feasibility of FIFWBI with VERO-4DRT system. Methods: As fundamental evaluation, we performed commissioning test with phantom. The absorbed dose evaluation at several reference points and dose distributionmore » including split area were performed. We planned 10 demonstrative shapes in phantom for measuring these contents with i-plan workstation (BrainLAB). As clinical evaluation, the dose distribution and dose indexes were evaluated with actual patient data. Five patients with breast cancer were designed FIFWBI radiotherapy plan with split fields. Then, the dose distribution and dose indexes (including Dmax, Dmin, D95, D5 and Homogeneity index) were evaluated in these plans. Results: As the results of fundamental evaluation, all absorbed dose errors between calculated and measured doses were within 2%. The gamma passing rates with 2 mm/3% criteria in all cases were 96±2%. As the results of clinical evaluation, the values of Dmax, D95, D50, D5, and Homogeneity Index were 41.7±0.90 Gy, 49.4±0.34 Gy, 52.26±0.24 Gy, and 1.39±0.03, respectively. For Japanese breast cancer patients, this technique was feasible. However, the large split region was happened in FIFWBI in case of patient with large breast. Conclusion: We evaluated the FIFWBI technique with VERO-4DRT system. This technique is feasible for Japanese patients, but the patient with large breast should be disagreed with this technique.« less

Three-dimensional ultrasound strain imaging of skeletal muscles

NASA Astrophysics Data System (ADS)

Gijsbertse, K.; Sprengers, A. M. J.; Nillesen, M. M.; Hansen, H. H. G.; Lopata, R. G. P.; Verdonschot, N.; de Korte, C. L.

2017-01-01

In this study, a multi-dimensional strain estimation method is presented to assess local relative deformation in three orthogonal directions in 3D space of skeletal muscles during voluntary contractions. A rigid translation and compressive deformation of a block phantom, that mimics muscle contraction, is used as experimental validation of the 3D technique and to compare its performance with respect to a 2D based technique. Axial, lateral and (in case of 3D) elevational displacements are estimated using a cross-correlation based displacement estimation algorithm. After transformation of the displacements to a Cartesian coordinate system, strain is derived using a least-squares strain estimator. The performance of both methods is compared by calculating the root-mean-squared error of the estimated displacements with the calculated theoretical displacements of the phantom experiments. We observe that the 3D technique delivers more accurate displacement estimations compared to the 2D technique, especially in the translation experiment where out-of-plane motion hampers the 2D technique. In vivo application of the 3D technique in the musculus vastus intermedius shows good resemblance between measured strain and the force pattern. Similarity of the strain curves of repetitive measurements indicates the reproducibility of voluntary contractions. These results indicate that 3D ultrasound is a valuable imaging tool to quantify complex tissue motion, especially when there is motion in three directions, which results in out-of-plane errors for 2D techniques.

Multimodality optical imaging of embryonic heart microstructure

PubMed Central

Yelin, Ronit; Yelin, Dvir; Oh, Wang-Yuhl; Yun, Seok H.; Boudoux, Caroline; Vakoc, Benjamin J.; Bouma, Brett E.; Tearney, Guillermo J.

2009-01-01

Study of developmental heart defects requires the visualization of the microstructure and function of the embryonic myocardium, ideally with minimal alterations to the specimen. We demonstrate multiple endogenous contrast optical techniques for imaging the Xenopus laevis tadpole heart. Each technique provides distinct and complementary imaging capabilities, including: 1. 3-D coherence microscopy with subcellular (1 to 2 µm) resolution in fixed embryos, 2. real-time reflectance confocal microscopy with large penetration depth in vivo, and 3. ultra-high speed (up to 900 frames per second) that enables real-time 4-D high resolution imaging in vivo. These imaging modalities can provide a comprehensive picture of the morphologic and dynamic phenotype of the embryonic heart. The potential of endogenous-contrast optical microscopy is demonstrated for investigation of the teratogenic effects of ethanol. Microstructural abnormalities associated with high levels of ethanol exposure are observed, including compromised heart looping and loss of ventricular trabecular mass. PMID:18163837

Multimodality optical imaging of embryonic heart microstructure.

PubMed

Yelin, Ronit; Yelin, Dvir; Oh, Wang-Yuhl; Yun, Seok H; Boudoux, Caroline; Vakoc, Benjamin J; Bouma, Brett E; Tearney, Guillermo J

2007-01-01

Study of developmental heart defects requires the visualization of the microstructure and function of the embryonic myocardium, ideally with minimal alterations to the specimen. We demonstrate multiple endogenous contrast optical techniques for imaging the Xenopus laevis tadpole heart. Each technique provides distinct and complementary imaging capabilities, including: 1. 3-D coherence microscopy with subcellular (1 to 2 microm) resolution in fixed embryos, 2. real-time reflectance confocal microscopy with large penetration depth in vivo, and 3. ultra-high speed (up to 900 frames per second) that enables real-time 4-D high resolution imaging in vivo. These imaging modalities can provide a comprehensive picture of the morphologic and dynamic phenotype of the embryonic heart. The potential of endogenous-contrast optical microscopy is demonstrated for investigation of the teratogenic effects of ethanol. Microstructural abnormalities associated with high levels of ethanol exposure are observed, including compromised heart looping and loss of ventricular trabecular mass.

Dosimetric comparison of 3D conformal, IMRT, and V-MAT techniques for accelerated partial-breast irradiation (APBI)

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

Qiu, Jian-Jian; Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai; Department of Oncology, Shanghai Medical College, Fudan University, Shanghai

2014-07-01

The purpose is to dosimetrically compare the following 3 delivery techniques: 3-dimensional conformal radiation therapy (3D-CRT), intensity-modulated arc therapy (IMRT), and volumetric-modulated arc therapy (V-MAT) in the treatment of accelerated partial-breast irradiation (APBI). Overall, 16 patients with T1/2N0 breast cancer were treated with 3D-CRT (multiple, noncoplanar photon fields) on the RTOG 0413 partial-breast trial. These cases were subsequently replanned using static gantry IMRT and V-MAT technology to understand dosimetric differences among these 3 techniques. Several dosimetric parameters were used in plan quality evaluation, including dose conformity index (CI) and dose-volume histogram analysis of normal tissue coverage. Quality assurance studies includingmore » gamma analysis were performed to compare the measured and calculated dose distributions. The IMRT and V-MAT plans gave more conformal target dose distributions than the 3D-CRT plans (p < 0.05 in CI). The volume of ipsilateral breast receiving 5 and 10 Gy was significantly less using the V-MAT technique than with either 3D-CRT or IMRT (p < 0.05). The maximum lung dose and the ipsilateral lung volume receiving 10 (V{sub 10}) or 20 Gy (V{sub 20}) were significantly less with both V-MAT and IMRT (p < 0.05). The IMRT technique was superior to 3D-CRT and V-MAT of low dose distributions in ipsilateral lung (p < 0.05 in V{sub 5} and D{sub 5}). The total mean monitor units (MUs) for V-MAT (621.0 ± 111.9) were 12.2% less than those for 3D-CRT (707.3 ± 130.9) and 46.5% less than those for IMRT (1161.4 ± 315.6) (p < 0.05). The average machine delivery time was 1.5 ± 0.2 minutes for the V-MAT plans, 7.0 ± 1.6 minutes for the 3D-CRT plans, and 11.5 ± 1.9 minutes for the IMRT plans, demonstrating much less delivery time for V-MAT. Based on this preliminary study, V-MAT and IMRT techniques offer improved dose conformity as compared with 3D-CRT techniques without increasing dose to the ipsilateral lung. In terms of MU and delivery time, V-MAT is significantly more efficient for APBI than for conventional 3D-CRT and static-beam IMRT.« less

Phonon thermal conduction in novel 2D materials.

PubMed

Xu, Xiangfan; Chen, Jie; Li, Baowen

2016-12-07

Recently, there has been increasing interest in phonon thermal transport in low-dimensional materials, due to the crucial importance of dissipating and managing heat in micro- and nano-electronic devices. Significant progress has been achieved for one-dimensional (1D) systems, both theoretically and experimentally. However, the study of heat conduction in two-dimensional (2D) systems is still in its infancy due to the limited availability of 2D materials and the technical challenges of fabricating suspended samples that are suitable for thermal measurements. In this review, we outline different experimental techniques and theoretical approaches for phonon thermal transport in 2D materials, discuss the problems and challenges of phonon thermal transport measurements and provide a comparison between existing experimental data. Special attention will be given to the effects of size, dimensionality, anisotropy and mode contributions in novel 2D systems, including graphene, boron nitride, MoS 2 , black phosphorous and silicene.

Limited angle C-arm tomosynthesis reconstruction algorithms

NASA Astrophysics Data System (ADS)

Malalla, Nuhad A. Y.; Xu, Shiyu; Chen, Ying

2015-03-01

In this paper, C-arm tomosynthesis with digital detector was investigated as a novel three dimensional (3D) imaging technique. Digital tomosythses is an imaging technique to provide 3D information of the object by reconstructing slices passing through the object, based on a series of angular projection views with respect to the object. C-arm tomosynthesis provides two dimensional (2D) X-ray projection images with rotation (-/+20 angular range) of both X-ray source and detector. In this paper, four representative reconstruction algorithms including point by point back projection (BP), filtered back projection (FBP), simultaneous algebraic reconstruction technique (SART) and maximum likelihood expectation maximization (MLEM) were investigated. Dataset of 25 projection views of 3D spherical object that located at center of C-arm imaging space was simulated from 25 angular locations over a total view angle of 40 degrees. With reconstructed images, 3D mesh plot and 2D line profile of normalized pixel intensities on focus reconstruction plane crossing the center of the object were studied with each reconstruction algorithm. Results demonstrated the capability to generate 3D information from limited angle C-arm tomosynthesis. Since C-arm tomosynthesis is relatively compact, portable and can avoid moving patients, it has been investigated for different clinical applications ranging from tumor surgery to interventional radiology. It is very important to evaluate C-arm tomosynthesis for valuable applications.

Estimation of 2D to 3D dimensions and proportionality indices for facial examination.

PubMed

Martos, Rubén; Valsecchi, Andrea; Ibáñez, Oscar; Alemán, Inmaculada

2018-06-01

Photo-anthropometry is a metric-based facial image comparison technique where measurements of the face are taken from an image using predetermined facial landmarks. In particular, dimensions and proportionality indices (DPIs) are compared to DPIs from another facial image. Different studies concluded that photo-anthropometric facial comparison, as it is currently practiced, is unsuitable for elimination purposes. The major limitation is the need for images acquired under very restrictive, controlled conditions. To overcome this latter issue, we propose a novel methodology to estimate 3D DPIs from 2D ones. It uses computer graphic techniques to simulate thousands of facial photographs under known camera conditions and regression to derive the mathematical relationship between 2D and 3D DPIs automatically. Additionally, we present a methodology that makes use of the estimated 3D DPIs for reducing the number of potential matches of a given unknown facial photograph within a set of known candidates. The error in the estimation of the 3D DPIs can be as large as 35%, but both I and III quartiles are consistently inside the ±5% range. The methodology for filtering cases has demonstrated to be useful in the task of narrowing down the list of possible candidates for a given photograph. It is able to remove on average (validated using cross-validation technique) 57% and 24% of the negative cases, depending on the amounts of DPIs available. Limitations of the work developed together with open research lines are included within the Discussion section. Copyright © 2018 Elsevier B.V. All rights reserved.

3D printed electromagnetic transmission and electronic structures fabricated on a single platform using advanced process integration techniques

NASA Astrophysics Data System (ADS)

Deffenbaugh, Paul Issac

3D printing has garnered immense attention from many fields including in-office rapid prototyping of mechanical parts, outer-space satellite replication, garage functional firearm manufacture, and NASA rocket engine component fabrication. 3D printing allows increased design flexibility in the fabrication of electronics, microwave circuits and wireless antennas and has reached a level of maturity which allows functional parts to be printed. Much more work is necessary in order to perfect the processes of 3D printed electronics especially in the area of automation. Chapter 1 shows several finished prototypes of 3D printed electronics as well as newly developed techniques in fabrication. Little is known about the RF and microwave properties and applications of the standard materials which have been developed for 3D printing. Measurement of a wide variety of materials over a broad spectrum of frequencies up to 10 GHz using a variety of well-established measurement methods is performed throughout chapter 2. Several types of high frequency RF transmission lines are fabricated and valuable model-matched data is gathered and provided in chapter 3 for future designers' use. Of particular note is a fully 3D printed stripline which was automatically fabricated in one process on one machine. Some core advantages of 3D printing RF/microwave components include rapid manufacturing of complex, dimensionally sensitive circuits (such as antennas and filters which are often iteratively tuned) and the ability to create new devices that cannot be made using standard fabrication techniques. Chapter 4 describes an exemplary fully 3D printed curved inverted-F antenna.

Results of endocapsular phacofracture debulking of hard cataracts.

PubMed

Davison, James A

2015-01-01

To present a phacoemulsification technique for hard cataracts and compare postoperative results using two different ultrasonic tip motions during quadrant removal. A phacoemulsification technique which employs in situ fracture and endocapsular debulking for hard cataracts is presented. The prospective study included 56 consecutive cases of hard cataract (LOCS III NC [Lens Opacification Classification System III, nuclear color], average 4.26), which were operated using the Infiniti machine and the Partial Kelman tip. Longitudinal tip movement was used for sculpting for all cases which were randomized to receive longitudinal or torsional/interjected longitudinal (Intelligent Phaco [IP]) strategies for quadrant removal. Measurements included cumulative dissipated energy (CDE), 3 months postoperative surgically induced astigmatism (SIA), and corneal endothelial cell density (ECD) losses. No complications were recorded in any of the cases. Respective overall and longitudinal vs IP means were as follows: CDE, 51.6±15.6 and 55.7±15.5 vs 48.6±15.1; SIA, 0.36±0.2 D and 0.4±0.2 D vs 0.3±0.2 D; and mean ECD loss, 4.1%±10.8% and 5.9%±13.4% vs 2.7%±7.8%. The differences between longitudinal and IP were not significant for any of the three categories. The endocapsular phacofracture debulking technique is safe and effective for phacoemulsification of hard cataracts using longitudinal or torsional IP strategies for quadrant removal with the Infiniti machine and Partial Kelman tip.

Comparison of alternative image reformatting techniques in micro-computed tomography and tooth clearing for detailed canal morphology.

PubMed

Lee, Ki-Wook; Kim, Yeun; Perinpanayagam, Hiran; Lee, Jong-Ki; Yoo, Yeon-Jee; Lim, Sang-Min; Chang, Seok Woo; Ha, Byung-Hyun; Zhu, Qiang; Kum, Kee-Yeon

2014-03-01

Micro-computed tomography (MCT) shows detailed root canal morphology that is not seen with traditional tooth clearing. However, alternative image reformatting techniques in MCT involving 2-dimensional (2D) minimum intensity projection (MinIP) and 3-dimensional (3D) volume-rendering reconstruction have not been directly compared with clearing. The aim was to compare alternative image reformatting techniques in MCT with tooth clearing on the mesiobuccal (MB) root of maxillary first molars. Eighteen maxillary first molar MB roots were scanned, and 2D MinIP and 3D volume-rendered images were reconstructed. Subsequently, the same MB roots were processed by traditional tooth clearing. Images from 2D, 3D, 2D + 3D, and clearing techniques were assessed by 4 endodontists to classify canal configuration and to identify fine anatomic structures such as accessory canals, intercanal communications, and loops. All image reformatting techniques in MCT showed detailed configurations and numerous fine structures, such that none were classified as simple type I or II canals; several were classified as types III and IV according to Weine classification or types IV, V, and VI according to Vertucci; and most were nonclassifiable because of their complexity. The clearing images showed less detail, few fine structures, and numerous type I canals. Classification of canal configuration was in 100% intraobserver agreement for all 18 roots visualized by any of the image reformatting techniques in MCT but for only 4 roots (22.2%) classified according to Weine and 6 (33.3%) classified according to Vertucci, when using the clearing technique. The combination of 2D MinIP and 3D volume-rendered images showed the most detailed canal morphology and fine anatomic structures. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Substrate induced changes in atomically thin 2-dimensional semiconductors: Fundamentals, engineering, and applications

NASA Astrophysics Data System (ADS)

Sun, Yinghui; Wang, Rongming; Liu, Kai

2017-03-01

Substrate has great influences on materials syntheses, properties, and applications. The influences are particularly crucial for atomically thin 2-dimensional (2D) semiconductors. Their thicknesses are less than 1 nm; however, the lateral sizes can reach up to several inches or more. Therefore, these materials must be placed onto a variety of substrates before subsequent post-processing techniques for final electronic or optoelectronic devices. Recent studies reveal that substrates have been employed as ways to modulate the optical, electrical, mechanical, and chemical properties of 2D semiconductors. In this review, we summarize recent progress upon the effects of substrates on properties of 2D semiconductors, mostly focused on 2D transition metal dichalcogenides, through viewpoints of both fundamental physics and device applications. First, we discuss various effects of substrates, including interface strain, charge transfer, dielectric screening, and optical interference. Second, we show the modulation of 2D semiconductors by substrate engineering, including novel substrates (patterned substrates, 2D-material substrates, etc.) and active substrates (phase transition materials, ferroelectric materials, flexible substrates, etc.). Last, we present prospectives and challenges in this research field. This review provides a comprehensive understanding of the substrate effects, and may inspire new ideas of novel 2D devices based on substrate engineering.

Feasibility of Tactical Air Delivery Resupply Using Gliders

DTIC Science & Technology

2016-12-01

using modern design and manufacturing techniques including AutoCAD, 3D printing , laser cutting and CorelDraw, and conducting field testing and...Sparrow,” using modern design and manufacturing techniques including AutoCAD, 3D printing , laser cutting and CorelDraw, and conducting field testing and...the desired point(s) of impact due to the atmospheric three-dimensional ( 3D ) wind and density field encountered by the descending load under canopy

A comparative study of multi-sensor data fusion methods for highly accurate assessment of manufactured parts

NASA Astrophysics Data System (ADS)

Hannachi, Ammar; Kohler, Sophie; Lallement, Alex; Hirsch, Ernest

2015-04-01

3D modeling of scene contents takes an increasing importance for many computer vision based applications. In particular, industrial applications of computer vision require efficient tools for the computation of this 3D information. Routinely, stereo-vision is a powerful technique to obtain the 3D outline of imaged objects from the corresponding 2D images. As a consequence, this approach provides only a poor and partial description of the scene contents. On another hand, for structured light based reconstruction techniques, 3D surfaces of imaged objects can often be computed with high accuracy. However, the resulting active range data in this case lacks to provide data enabling to characterize the object edges. Thus, in order to benefit from the positive points of various acquisition techniques, we introduce in this paper promising approaches, enabling to compute complete 3D reconstruction based on the cooperation of two complementary acquisition and processing techniques, in our case stereoscopic and structured light based methods, providing two 3D data sets describing respectively the outlines and surfaces of the imaged objects. We present, accordingly, the principles of three fusion techniques and their comparison based on evaluation criterions related to the nature of the workpiece and also the type of the tackled application. The proposed fusion methods are relying on geometric characteristics of the workpiece, which favour the quality of the registration. Further, the results obtained demonstrate that the developed approaches are well adapted for 3D modeling of manufactured parts including free-form surfaces and, consequently quality control applications using these 3D reconstructions.

Rocket nozzle thermal shock tests in an arc heater facility

NASA Technical Reports Server (NTRS)

Painter, James H.; Williamson, Ronald A.

1986-01-01

A rocket motor nozzle thermal structural test technique that utilizes arc heated nitrogen to simulate a motor burn was developed. The technique was used to test four heavily instrumented full-scale Star 48 rocket motor 2D carbon/carbon segments at conditions simulating the predicted thermal-structural environment. All four nozzles survived the tests without catastrophic or other structural failures. The test technique demonstrated promise as a low cost, controllable alternative to rocket motor firing. The technique includes the capability of rapid termination in the event of failure, allowing post-test analysis.

Ultra-wide-band 3D microwave imaging scanner for the detection of concealed weapons

NASA Astrophysics Data System (ADS)

Rezgui, Nacer-Ddine; Andrews, David A.; Bowring, Nicholas J.

2015-10-01

The threat of concealed weapons, explosives and contraband in footwear, bags and suitcases has led to the development of new devices, which can be deployed for security screening. To address known deficiencies of metal detectors and x-rays, an UWB 3D microwave imaging scanning apparatus using FMCW stepped frequency working in the K and Q bands and with a planar scanning geometry based on an x y stage, has been developed to screen suspicious luggage and footwear. To obtain microwave images of the concealed weapons, the targets are placed above the platform and the single transceiver horn antenna attached to the x y stage is moved mechanically to perform a raster scan to create a 2D synthetic aperture array. The S11 reflection signal of the transmitted sweep frequency from the target is acquired by a VNA in synchronism with each position step. To enhance and filter from clutter and noise the raw data and to obtain the 2D and 3D microwave images of the concealed weapons or explosives, data processing techniques are applied to the acquired signals. These techniques include background subtraction, Inverse Fast Fourier Transform (IFFT), thresholding, filtering by gating and windowing and deconvolving with the transfer function of the system using a reference target. To focus the 3D reconstructed microwave image of the target in range and across the x y aperture without using focusing elements, 3D Synthetic Aperture Radar (SAR) techniques are applied to the post-processed data. The K and Q bands, between 15 to 40 GHz, show good transmission through clothing and dielectric materials found in luggage and footwear. A description of the system, algorithms and some results with replica guns and a comparison of microwave images obtained by IFFT, 2D and 3D SAR techniques are presented.

Mapping cardiogenic oscillations using synchrotron-based phase contrast CT imaging

NASA Astrophysics Data System (ADS)

Thurgood, Jordan; Dubsky, Stephen; Siu, Karen K. W.; Wallace, Megan; Siew, Melissa; Hooper, Stuart; Fouras, Andreas

2012-10-01

In many animals, including humans, the lungs encase the majority of the heart thus the motion of each organ affects the other. The effects of the motion of the heart on the lungs potentially provides information with regards to both lung and heart health. We present a novel technique that is capable of measuring the effect of the heart on the surrounding lung tissue through the use of advanced synchrotron imaging techniques and recently developed X-ray velocimetry methods. This technique generates 2D frequency response maps of the lung tissue motion at multiple projection angles from projection X-ray images. These frequency response maps are subsequently used to generate 3D reconstructions of the lung tissue exhibiting motion at the frequency of ventilation and the lung tissue exhibiting motion at the frequency of the heart. This technique has a combined spatial and temporal resolution sufficient to observe the dynamic and complex 3D nature of lung-heart interactions.

Neutron Detection With Ultra-Fast Digitizer and Pulse Identification Techniques on DIII-D

NASA Astrophysics Data System (ADS)

Zhu, Y. B.; Heidbrink, W. W.; Piglowski, D. A.

2013-10-01

A prototype system for neutron detection with an ultra-fast digitizer and pulse identification techniques has been implemented on the DIII-D tokamak. The system consists of a cylindrical neutron fission chamber, a charge sensitive amplifier, and a GaGe Octopus 12-bit CompuScope digitizer card installed in a Linux computer. Digital pulse identification techniques have been successfully performed at maximum data acquisition rate of 50 MSPS with on-board memory of 2 GS. Compared to the traditional approach with fast nuclear electronics for pulse counting, this straightforward digital solution has many advantages, including reduced expense, improved accuracy, higher counting rate, and easier maintenance. The system also provides the capability of neutron-gamma pulse shape discrimination and pulse height analysis. Plans for the upgrade of the old DIII-D neutron counting system with these techniques will be presented. Work supported by the US Department of Energy under SC-G903402, and DE-FC02-04ER54698.

Optical 3D watermark based digital image watermarking for telemedicine

NASA Astrophysics Data System (ADS)

Li, Xiao Wei; Kim, Seok Tae

2013-12-01

Region of interest (ROI) of a medical image is an area including important diagnostic information and must be stored without any distortion. This algorithm for application of watermarking technique for non-ROI of the medical image preserving ROI. The paper presents a 3D watermark based medical image watermarking scheme. In this paper, a 3D watermark object is first decomposed into 2D elemental image array (EIA) by a lenslet array, and then the 2D elemental image array data is embedded into the host image. The watermark extraction process is an inverse process of embedding. The extracted EIA through the computational integral imaging reconstruction (CIIR) technique, the 3D watermark can be reconstructed. Because the EIA is composed of a number of elemental images possesses their own perspectives of a 3D watermark object. Even though the embedded watermark data badly damaged, the 3D virtual watermark can be successfully reconstructed. Furthermore, using CAT with various rule number parameters, it is possible to get many channels for embedding. So our method can recover the weak point having only one transform plane in traditional watermarking methods. The effectiveness of the proposed watermarking scheme is demonstrated with the aid of experimental results.

Broiler weight estimation based on machine vision and artificial neural network.

PubMed

Amraei, S; Abdanan Mehdizadeh, S; Salari, S

2017-04-01

1. Machine vision and artificial neural network (ANN) procedures were used to estimate live body weight of broiler chickens in 30 1-d-old broiler chickens reared for 42 d. 2. Imaging was performed two times daily. To localise chickens within the pen, an ellipse fitting algorithm was used and the chickens' head and tail removed using the Chan-Vese method. 3. The correlations between the body weight and 6 physical extracted features indicated that there were strong correlations between body weight and the 5 features including area, perimeter, convex area, major and minor axis length. 5. According to statistical analysis there was no significant difference between morning and afternoon data over 42 d. 6. In an attempt to improve the accuracy of live weight approximation different ANN techniques, including Bayesian regulation, Levenberg-Marquardt, Scaled conjugate gradient and gradient descent were used. Bayesian regulation with R 2 value of 0.98 was the best network for prediction of broiler weight. 7. The accuracy of the machine vision technique was examined and most errors were less than 50 g.

Use of micro computed-tomography and 3D printing for reverse engineering of mouse embryo nasal capsule

NASA Astrophysics Data System (ADS)

Tesařová, M.; Zikmund, T.; Kaucká, M.; Adameyko, I.; Jaroš, J.; Paloušek, D.; Škaroupka, D.; Kaiser, J.

2016-03-01

Imaging of increasingly complex cartilage in vertebrate embryos is one of the key tasks of developmental biology. This is especially important to study shape-organizing processes during initial skeletal formation and growth. Advanced imaging techniques that are reflecting biological needs give a powerful impulse to push the boundaries of biological visualization. Recently, techniques for contrasting tissues and organs have improved considerably, extending traditional 2D imaging approaches to 3D . X-ray micro computed tomography (μCT), which allows 3D imaging of biological objects including their internal structures with a resolution in the micrometer range, in combination with contrasting techniques seems to be the most suitable approach for non-destructive imaging of embryonic developing cartilage. Despite there are many software-based ways for visualization of 3D data sets, having a real solid model of the studied object might give novel opportunities to fully understand the shape-organizing processes in the developing body. In this feasibility study we demonstrated the full procedure of creating a real 3D object of mouse embryo nasal capsule, i.e. the staining, the μCT scanning combined by the advanced data processing and the 3D printing.

Modeling Physiological Events in 2D vs. 3D Cell Culture

PubMed Central

Duval, Kayla; Grover, Hannah; Han, Li-Hsin; Mou, Yongchao; Pegoraro, Adrian F.; Fredberg, Jeffery

2017-01-01

Cell culture has become an indispensable tool to help uncover fundamental biophysical and biomolecular mechanisms by which cells assemble into tissues and organs, how these tissues function, and how that function becomes disrupted in disease. Cell culture is now widely used in biomedical research, tissue engineering, regenerative medicine, and industrial practices. Although flat, two-dimensional (2D) cell culture has predominated, recent research has shifted toward culture using three-dimensional (3D) structures, and more realistic biochemical and biomechanical microenvironments. Nevertheless, in 3D cell culture, many challenges remain, including the tissue-tissue interface, the mechanical microenvironment, and the spatiotemporal distributions of oxygen, nutrients, and metabolic wastes. Here, we review 2D and 3D cell culture methods, discuss advantages and limitations of these techniques in modeling physiologically and pathologically relevant processes, and suggest directions for future research. PMID:28615311

[Phenolic acid derivatives from Bauhinia glauca subsp. pernervosa].

PubMed

Zhao, Qiao-Li; Wu, Zeng-Bao; Zheng, Zhi-Hui; Lu, Xin-Hua; Liang, Hong; Cheng, Wei; Zhang, Qing-Ying; Zhao, Yu-Ying

2011-08-01

To study the chemical constituents of Bauhinia glauca subsp. pernervosa, eleven phenolic acids were isolated from a 95% ethanol extract by using a combination of various chromatographic techniques including column chromatography over silica gel, ODS, MCI, Sephadex LH-20, and semi-preparative HPLC. By spectroscopic techniques including 1H NMR, 13C NMR, 2D NMR, and HR-ESI-MS, these compounds were identified as isopropyl O-beta-(6'-O-galloyl)-glucopyranoside (1), ethyl O-beta-(6'-O-galloyl)-glucopyranoside (2), 3, 4, 5-trimethoxyphenyl-(6'-O-galloyl)-O-beta-D-glucopyranoside (3), 3, 4, 5-trimethoxyphenyl-beta-D-glucopyranoside (4), gallic acid (5), methyl gallate (6), ethyl gallate (7), protocatechuic acid (8), 3, 5-dimethoxy-4-hydroxybenzoic acid (9), erigeside C (10) and glucosyringic acid (11). Among them, compound 1 is a new polyhydroxyl compound; compounds 2, 10, and 11 were isolated from the genus Bauhinia for the first time, and the other compounds were isolated from the plant for the first time. Compounds 6 and 8 showed significant protein tyrosine phosphatase1B (PTP1B) inhibitory activity in vitro with the IC50 values of 72.3 and 54.1 micromol x L(-1), respectively.

Utilization of SABRE-derived hyperpolarization to detect low-concentration analytes via 1D and 2D NMR methods.

PubMed

Lloyd, Lyrelle S; Adams, Ralph W; Bernstein, Michael; Coombes, Steven; Duckett, Simon B; Green, Gary G R; Lewis, Richard J; Mewis, Ryan E; Sleigh, Christopher J

2012-08-08

The characterization of materials by the inherently insensitive method of NMR spectroscopy plays a vital role in chemistry. Increasingly, hyperpolarization is being used to address the sensitivity limitation. Here, by reference to quinoline, we illustrate that the SABRE hyperpolarization technique, which uses para-hydrogen as the source of polarization, enables the rapid completion of a range of NMR measurements. These include the collection of (13)C, (13)C{(1)H}, and NOE data in addition to more complex 2D COSY, ultrafast 2D COSY and 2D HMBC spectra. The observations are made possible by the use of a flow probe and external sample preparation cell to re-hyperpolarize the substrate between transients, allowing repeat measurements to be made within seconds. The potential benefit of the combination of SABRE and 2D NMR methods for rapid characterization of low-concentration analytes is therefore established.

Aspects of defects in 3d-3d correspondence

DOE PAGES

Gang, Dongmin; Kim, Nakwoo; Romo, Mauricio; ...

2016-10-12

In this paper we study supersymmetric co-dimension 2 and 4 defects in the compactification of the 6d (2, 0) theory of type A N-1 on a 3-manifold M . The so-called 3d-3d correspondence is a relation between complexified Chern-Simons theory (with gauge group SL(N,C) ) on M and a 3d N=2 theory T N [M ]. We study this correspondence in the presence of supersymmetric defects, which are knots/links inside the 3-manifold. Our study employs a number of different methods: state-integral models for complex Chern-Simons theory, cluster algebra techniques, domain wall theory T [SU(N )], 5d N=2 SYM, and alsomore » supergravity analysis through holography. These methods are complementary and we find agreement between them. In some cases the results lead to highly non-trivial predictions on the partition function. Our discussion includes a general expression for the cluster partition function, which can be used to compute in the presence of maximal and certain class of non-maximal punctures when N > 2. We also highlight the non-Abelian description of the 3d N=2 T N [M ] theory with defect included, when such a description is available. This paper is a companion to our shorter paper, which summarizes our main results.« less

Colloidal Covalent Organic Frameworks

PubMed Central

2017-01-01

Covalent organic frameworks (COFs) are two- or three-dimensional (2D or 3D) polymer networks with designed topology and chemical functionality, permanent porosity, and high surface areas. These features are potentially useful for a broad range of applications, including catalysis, optoelectronics, and energy storage devices. But current COF syntheses offer poor control over the material’s morphology and final form, generally providing insoluble and unprocessable microcrystalline powder aggregates. COF polymerizations are often performed under conditions in which the monomers are only partially soluble in the reaction solvent, and this heterogeneity has hindered understanding of their polymerization or crystallization processes. Here we report homogeneous polymerization conditions for boronate ester-linked, 2D COFs that inhibit crystallite precipitation, resulting in stable colloidal suspensions of 2D COF nanoparticles. The hexagonal, layered structures of the colloids are confirmed by small-angle and wide-angle X-ray scattering, and kinetic characterization provides insight into the growth process. The colloid size is modulated by solvent conditions, and the technique is demonstrated for four 2D boronate ester-linked COFs. The diameter of individual COF nanoparticles in solution is monitored and quantified during COF growth and stabilization at elevated temperature using in situ variable-temperature liquid cell transmission electron microscopy imaging, a new characterization technique that complements conventional bulk scattering techniques. Solution casting of the colloids yields a free-standing transparent COF film with retained crystallinity and porosity, as well as preferential crystallite orientation. Collectively this structural control provides new opportunities for understanding COF formation and designing morphologies for device applications. PMID:28149954

Local 2D-2D tunneling in high mobility electron systems

NASA Astrophysics Data System (ADS)

Pelliccione, Matthew; Sciambi, Adam; Bartel, John; Goldhaber-Gordon, David; Pfeiffer, Loren; West, Ken; Lilly, Michael; Bank, Seth; Gossard, Arthur

2012-02-01

Many scanning probe techniques have been utilized in recent years to measure local properties of high mobility two-dimensional (2D) electron systems in GaAs. However, most techniques lack the ability to tunnel into the buried 2D system and measure local spectroscopic information. We report scanning gate measurements on a bilayer GaAs/AlGaAs heterostructure that allows for a local modulation of tunneling between two 2D electron layers. We call this technique Virtual Scanning Tunneling Microscopy (VSTM) [1,2] as the influence of the scanning gate is analogous to an STM tip, except at a GaAs/AlGaAs interface instead of a surface. We will discuss the spectroscopic capabilities of the technique, and show preliminary results of measurements on a high mobility 2D electron system.[1] A. Sciambi, M. Pelliccione et al., Appl. Phys. Lett. 97, 132103 (2010).[2] A. Sciambi, M. Pelliccione et al., Phys. Rev. B 84, 085301 (2011).

Comparison of 2-D and 3-D estimates of placental volume in early pregnancy.

PubMed

Aye, Christina Y L; Stevenson, Gordon N; Impey, Lawrence; Collins, Sally L

2015-03-01

Ultrasound estimation of placental volume (PlaV) between 11 and 13 wk has been proposed as part of a screening test for small-for-gestational-age babies. A semi-automated 3-D technique, validated against the gold standard of manual delineation, has been found at this stage of gestation to predict small-for-gestational-age at term. Recently, when used in the third trimester, an estimate obtained using a 2-D technique was found to correlate with placental weight at delivery. Given its greater simplicity, the 2-D technique might be more useful as part of an early screening test. We investigated if the two techniques produced similar results when used in the first trimester. The correlation between PlaV values calculated by the two different techniques was assessed in 139 first-trimester placentas. The agreement on PlaV and derived "standardized placental volume," a dimensionless index correcting for gestational age, was explored with the Mann-Whitney test and Bland-Altman plots. Placentas were categorized into five different shape subtypes, and a subgroup analysis was performed. Agreement was poor for both PlaV and standardized PlaV (p < 0.001 and p < 0.001), with the 2-D technique yielding larger estimates for both indices compared with the 3-D method. The mean difference in standardized PlaV values between the two methods was 0.007 (95% confidence interval: 0.006-0.009). The best agreement was found for regular rectangle-shaped placentas (p = 0.438 and p = 0.408). The poor correlation between the 2-D and 3-D techniques may result from the heterogeneity of placental morphology at this stage of gestation. In early gestation, the simpler 2-D estimates of PlaV do not correlate strongly with those obtained with the validated 3-D technique. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Chronology of DIC technique based on the fundamental mathematical modeling and dehydration impact.

PubMed

Alias, Norma; Saipol, Hafizah Farhah Saipan; Ghani, Asnida Che Abd

2014-12-01

A chronology of mathematical models for heat and mass transfer equation is proposed for the prediction of moisture and temperature behavior during drying using DIC (Détente Instantanée Contrôlée) or instant controlled pressure drop technique. DIC technique has the potential as most commonly used dehydration method for high impact food value including the nutrition maintenance and the best possible quality for food storage. The model is governed by the regression model, followed by 2D Fick's and Fourier's parabolic equation and 2D elliptic-parabolic equation in a rectangular slice. The models neglect the effect of shrinkage and radiation effects. The simulations of heat and mass transfer equations with parabolic and elliptic-parabolic types through some numerical methods based on finite difference method (FDM) have been illustrated. Intel®Core™2Duo processors with Linux operating system and C programming language have been considered as a computational platform for the simulation. Qualitative and quantitative differences between DIC technique and the conventional drying methods have been shown as a comparative.

[Assessment of the hearing results in tympanoplasties with the use of palisade-technique].

PubMed

Wielgosz, Romuald; Mroczkowski, Edward

2006-01-01

The cartilage has been successfuly used in reconstructive ear surgery for more than one hundred years. Histologic study of autografts cartilage (tragal or conchal) showed good long-term preservation of cartilage cells. The aim of this paper is to assess the hearing results in tympanoplasties with the use of cartilage palisade technique. The retrospective analysis concerned 108 operated clinical cases. The cartilage palisade technique was performed in 28 tympanoplasties type I, 47 tympanoplasties type II, 21 tympanoplasties type III with columella and in 2 tympanoplasties type IV. Clinical assessment included otoscopy, test for eustachian tube ventilation, test with tuning fork, audiometry on a range 0,5, 1, 2 kHz and subjective evaluation based on questionaire. The Air Bone Gap (ABG) was noted as follows: < 10 dB among 67,8% of patients and 11-20 dB among 21,4% of patients in tympanoplasty type I. In tympanoplasty type II the ABG was responsively: < 10 dB - 80% patients, 11-20 dB - 10% patients. In the type III of tympanoplasty 40,4% of patients showed ABG < 10 dB and 42,5% of patients 11-20 dB. In the type III with columella we noted 15% patients with ABG < 10 dB and 65% of them with ABG 11-20 dB. The cartilage is a good autograft for reconstruction of the tympanic membrane, middle ear and the auditory wall because of stability and lack of secondary perforations. Long-term results in hearing are also satisfactory.

Development of Emissions Measurement Techniques for Afterburning Turbine Engines. Supplement 2. Afterburner Plume Computer Program User’s Manual.

DTIC Science & Technology

1975-10-01

AO-AUHb b27 UNCLASSIFIED GENERAL ELECTRIC CO CINCINNATI OHIO AIRCRAFT ENGINE GROUP F/G 2l/5 DEVELOPMENT OF EMISSIONS MEASUREMENT TECHNIQUES FOR...Colley D.R. Ferguson M.A. Smith GENERAL ELECTRIC COMPANY Aircraft Engine Group Cincinnati, Ohio 45215 October 1975 Technical Report AFAPL-TR-7 5-52...Service (NTIS). At NTIS, it will be avail’ able to the general public, including foreign nations. This technical report has been reviewed and is

Three-dimensional waveform sensitivity kernels

NASA Astrophysics Data System (ADS)

Marquering, Henk; Nolet, Guust; Dahlen, F. A.

1998-03-01

The sensitivity of intermediate-period (~10-100s) seismic waveforms to the lateral heterogeneity of the Earth is computed using an efficient technique based upon surface-wave mode coupling. This formulation yields a general, fully fledged 3-D relationship between data and model without imposing smoothness constraints on the lateral heterogeneity. The calculations are based upon the Born approximation, which yields a linear relation between data and model. The linear relation ensures fast forward calculations and makes the formulation suitable for inversion schemes; however, higher-order effects such as wave-front healing are neglected. By including up to 20 surface-wave modes, we obtain Fréchet, or sensitivity, kernels for waveforms in the time frame that starts at the S arrival and which includes direct and surface-reflected body waves. These 3-D sensitivity kernels provide new insights into seismic-wave propagation, and suggest that there may be stringent limitations on the validity of ray-theoretical interpretations. Even recently developed 2-D formulations, which ignore structure out of the source-receiver plane, differ substantially from our 3-D treatment. We infer that smoothness constraints on heterogeneity, required to justify the use of ray techniques, are unlikely to hold in realistic earth models. This puts the use of ray-theoretical techniques into question for the interpretation of intermediate-period seismic data. The computed 3-D sensitivity kernels display a number of phenomena that are counter-intuitive from a ray-geometrical point of view: (1) body waves exhibit significant sensitivity to structure up to 500km away from the source-receiver minor arc; (2) significant near-surface sensitivity above the two turning points of the SS wave is observed; (3) the later part of the SS wave packet is most sensitive to structure away from the source-receiver path; (4) the sensitivity of the higher-frequency part of the fundamental surface-wave mode is wider than for its faster, lower-frequency part; (5) delayed body waves may considerably influence fundamental Rayleigh and Love waveforms. The strong sensitivity of waveforms to crustal structure due to fundamental-mode-to-body-wave scattering precludes the use of phase-velocity filters to model body-wave arrivals. Results from the 3-D formulation suggest that the use of 2-D and 1-D techniques for the interpretation of intermediate-period waveforms should seriously be reconsidered.

Speckle lithography for fabricating Gaussian, quasi-random 2D structures and black silicon structures.

PubMed

Bingi, Jayachandra; Murukeshan, Vadakke Matham

2015-12-18

Laser speckle pattern is a granular structure formed due to random coherent wavelet interference and generally considered as noise in optical systems including photolithography. Contrary to this, in this paper, we use the speckle pattern to generate predictable and controlled Gaussian random structures and quasi-random structures photo-lithographically. The random structures made using this proposed speckle lithography technique are quantified based on speckle statistics, radial distribution function (RDF) and fast Fourier transform (FFT). The control over the speckle size, density and speckle clustering facilitates the successful fabrication of black silicon with different surface structures. The controllability and tunability of randomness makes this technique a robust method for fabricating predictable 2D Gaussian random structures and black silicon structures. These structures can enhance the light trapping significantly in solar cells and hence enable improved energy harvesting. Further, this technique can enable efficient fabrication of disordered photonic structures and random media based devices.

BAYESIAN SEMI-BLIND COMPONENT SEPARATION FOR FOREGROUND REMOVAL IN INTERFEROMETRIC 21 cm OBSERVATIONS

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

Zhang, Le; Timbie, Peter T.; Bunn, Emory F.

In this paper, we present a new Bayesian semi-blind approach for foreground removal in observations of the 21 cm signal measured by interferometers. The technique, which we call H i Expectation–Maximization Independent Component Analysis (HIEMICA), is an extension of the Independent Component Analysis technique developed for two-dimensional (2D) cosmic microwave background maps to three-dimensional (3D) 21 cm cosmological signals measured by interferometers. This technique provides a fully Bayesian inference of power spectra and maps and separates the foregrounds from the signal based on the diversity of their power spectra. Relying only on the statistical independence of the components, this approachmore » can jointly estimate the 3D power spectrum of the 21 cm signal, as well as the 2D angular power spectrum and the frequency dependence of each foreground component, without any prior assumptions about the foregrounds. This approach has been tested extensively by applying it to mock data from interferometric 21 cm intensity mapping observations under idealized assumptions of instrumental effects. We also discuss the impact when the noise properties are not known completely. As a first step toward solving the 21 cm power spectrum analysis problem, we compare the semi-blind HIEMICA technique to the commonly used Principal Component Analysis. Under the same idealized circumstances, the proposed technique provides significantly improved recovery of the power spectrum. This technique can be applied in a straightforward manner to all 21 cm interferometric observations, including epoch of reionization measurements, and can be extended to single-dish observations as well.« less

Quantitative techniques for musculoskeletal MRI at 7 Tesla.

PubMed

Bangerter, Neal K; Taylor, Meredith D; Tarbox, Grayson J; Palmer, Antony J; Park, Daniel J

2016-12-01

Whole-body 7 Tesla MRI scanners have been approved solely for research since they appeared on the market over 10 years ago, but may soon be approved for selected clinical neurological and musculoskeletal applications in both the EU and the United States. There has been considerable research work on musculoskeletal applications at 7 Tesla over the past decade, including techniques for ultra-high resolution morphological imaging, 3D T2 and T2* mapping, ultra-short TE applications, diffusion tensor imaging of cartilage, and several techniques for assessing proteoglycan content in cartilage. Most of this work has been done in the knee or other extremities, due to technical difficulties associated with scanning areas such as the hip and torso at 7 Tesla. In this manuscript, we first provide some technical context for 7 Tesla imaging, including challenges and potential advantages. We then review the major quantitative MRI techniques being applied to musculoskeletal applications on 7 Tesla whole-body systems.

TH-A-BRF-05: MRI of Individual Lymph Nodes to Guide Regional Breast Radiotherapy

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

Heijst, T van; Asselen, B van; Lagendijk, J

2014-06-15

Purpose: In regional radiotherapy (RT) for breast-cancer patients, direct visualization of individual lymph nodes (LNs) may reduce target volumes and Result in lower toxicity (i.e. reduced radiation pneumonitis, arm edema, arm morbidity), relative to standard CT-based delineations. To this end, newly designed magnetic resonance imaging (MRI) sequences were optimized and assessed qualitatively and quantitatively. Methods: In ten healthy female volunteers, a scanning protocol was developed and optimized. Coronal images were acquired in supine RT position positioned on a wedge board on a 1.5 T Ingenia (Philips) wide-bore MRI. In four volunteers the optimized MRI protocol was applied, including a 3-dimensionalmore » (3D) T1-weighted (T1w) fast-field-echo (FFE). T2w sequences, including 3D FFE, 3D and 2D fast spin echo (FSE), and diffusion-weighted single-shot echo-planar imaging (DWI) were also performed. Several fatsuppression techniques were used. Qualitative evaluation parameters included LN contrast, motion susceptibility, visibility of anatomical structures, and fat suppression. The number of visible axillary and supraclavicular LNs was also determined. Results: T1 FFE, insensitive to motion, lacked contrast of LNs, which often blended in with soft tissue and blood. T2 FFE showed high contrast, but some LNs were obscured due to motion. Both 2D and 3D FSE were motion-insensitive having high contrast, although some blood remained visible. 2D FSE showed more anatomical details, while in 3D FSE, some blurring occurred. DWI showed high LN contrast, but suffered from geometric distortions and low resolution. Fat suppression by mDixon was the most reliable in regions with magnetic-field inhomogeneities. The FSE sequences showed the highest sensitivity for LN detection. Conclusion: MRI of regional LNs was achieved in volunteers. The FSE techniques were robust and the most sensitive. Our optimized MRI sequences can facilitate direct delineation of individual LNs. This can Result in smaller target volumes and reduced toxicity in regional RT compared to standard CT planning.« less

Thermal lensing compensation optics for high power lasers

NASA Astrophysics Data System (ADS)

Scaggs, Michael; Haas, Gil

2011-03-01

Athermalization of focusing objectives is a common technique for optimizing imaging systems in the infrared where thermal effects are a major concern. The athermalization is generally done within the spectrum of interest and not generally applied to a single wavelength. The predominate glass used with high power infrared lasers in the near infrared of one micron, such as Nd:YAG and fiber lasers, is fused silica which has excellent thermal properties. All glasses, however, have a temperature coefficient of index of refraction (dn/dT) where as the glass heats up its index of refraction changes. Most glasses, fused silica included, have a positive dn/dT. A positive dn/dT will cause the focal length of the lens to decrease with a temperature rise. Many of the fluoride glasses, like CaF2, BaF2, LiF2, etc. have a negative dn/dT. By applying athermalization techniques of glass selection and optical design, the thermal lensing in a laser objective of a high power laser system can be substantially mitigated. We describe a passive method for minimizing thermal lensing of high power laser optics.

Dynamic three-dimensional display of common congenital cardiac defects from reconstruction of two-dimensional echocardiographic images.

PubMed

Hsieh, K S; Lin, C C; Liu, W S; Chen, F L

1996-01-01

Two-dimensional echocardiography had long been a standard diagnostic modality for congenital heart disease. Further attempts of three-dimensional reconstruction using two-dimensional echocardiographic images to visualize stereotypic structure of cardiac lesions have been successful only recently. So far only very few studies have been done to display three-dimensional anatomy of the heart through two-dimensional image acquisition because such complex procedures were involved. This study introduced a recently developed image acquisition and processing system for dynamic three-dimensional visualization of various congenital cardiac lesions. From December 1994 to April 1995, 35 cases were selected in the Echo Laboratory here from about 3000 Echo examinations completed. Each image was acquired on-line with specially designed high resolution image grazmber with EKG and respiratory gating technique. Off-line image processing using a window-architectured interactive software package includes construction of 2-D ehcocardiographic pixel to 3-D "voxel" with conversion of orthogonal to rotatory axial system, interpolation, extraction of region of interest, segmentation, shading and, finally, 3D rendering. Three-dimensional anatomy of various congenital cardiac defects was shown, including four cases with ventricular septal defects, two cases with atrial septal defects, and two cases with aortic stenosis. Dynamic reconstruction of a "beating heart" is recorded as vedio tape with video interface. The potential application of 3D display of the reconstruction from 2D echocardiographic images for the diagnosis of various congenital heart defects has been shown. The 3D display was able to improve the diagnostic ability of echocardiography, and clear-cut display of the various congenital cardiac defects and vavular stenosis could be demonstrated. Reinforcement of current techniques will expand future application of 3D display of conventional 2D images.

Localized Spatio-Temporal Constraints for Accelerated CMR Perfusion

PubMed Central

Akçakaya, Mehmet; Basha, Tamer A.; Pflugi, Silvio; Foppa, Murilo; Kissinger, Kraig V.; Hauser, Thomas H.; Nezafat, Reza

2013-01-01

Purpose To develop and evaluate an image reconstruction technique for cardiac MRI (CMR)perfusion that utilizes localized spatio-temporal constraints. Methods CMR perfusion plays an important role in detecting myocardial ischemia in patients with coronary artery disease. Breath-hold k-t based image acceleration techniques are typically used in CMR perfusion for superior spatial/temporal resolution, and improved coverage. In this study, we propose a novel compressed sensing based image reconstruction technique for CMR perfusion, with applicability to free-breathing examinations. This technique uses local spatio-temporal constraints by regularizing image patches across a small number of dynamics. The technique is compared to conventional dynamic-by-dynamic reconstruction, and sparsity regularization using a temporal principal-component (pc) basis, as well as zerofilled data in multi-slice 2D and 3D CMR perfusion. Qualitative image scores are used (1=poor, 4=excellent) to evaluate the technique in 3D perfusion in 10 patients and 5 healthy subjects. On 4 healthy subjects, the proposed technique was also compared to a breath-hold multi-slice 2D acquisition with parallel imaging in terms of signal intensity curves. Results The proposed technique results in images that are superior in terms of spatial and temporal blurring compared to the other techniques, even in free-breathing datasets. The image scores indicate a significant improvement compared to other techniques in 3D perfusion (2.8±0.5 vs. 2.3±0.5 for x-pc regularization, 1.7±0.5 for dynamic-by-dynamic, 1.1±0.2 for zerofilled). Signal intensity curves indicate similar dynamics of uptake between the proposed method with a 3D acquisition and the breath-hold multi-slice 2D acquisition with parallel imaging. Conclusion The proposed reconstruction utilizes sparsity regularization based on localized information in both spatial and temporal domains for highly-accelerated CMR perfusion with potential utility in free-breathing 3D acquisitions. PMID:24123058

Network Coding in Relay-based Device-to-Device Communications

PubMed Central

Huang, Jun; Gharavi, Hamid; Yan, Huifang; Xing, Cong-cong

2018-01-01

Device-to-Device (D2D) communications has been realized as an effective means to improve network throughput, reduce transmission latency, and extend cellular coverage in 5G systems. Network coding is a well-established technique known for its capability to reduce the number of retransmissions. In this article, we review state-of-the-art network coding in relay-based D2D communications, in terms of application scenarios and network coding techniques. We then apply two representative network coding techniques to dual-hop D2D communications and present an efficient relay node selecting mechanism as a case study. We also outline potential future research directions, according to the current research challenges. Our intention is to provide researchers and practitioners with a comprehensive overview of the current research status in this area and hope that this article may motivate more researchers to participate in developing network coding techniques for different relay-based D2D communications scenarios. PMID:29503504

Comparison of mandibular first molar mesial root canal morphology using micro-computed tomography and clearing technique.

PubMed

Kim, Yeun; Perinpanayagam, Hiran; Lee, Jong-Ki; Yoo, Yeon-Jee; Oh, Soram; Gu, Yu; Lee, Seung-Pyo; Chang, Seok Woo; Lee, Woocheol; Baek, Seung-Ho; Zhu, Qiang; Kum, Kee-Yeon

2015-08-01

Micro-computed tomography (MCT) with alternative image reformatting techniques shows complex and detailed root canal anatomy. This study compared two-dimensional (2D) and 3D MCT image reformatting with standard tooth clearing for studying mandibular first molar mesial root canal morphology. Extracted human mandibular first molar mesial roots (n=31) were scanned by MCT (Skyscan 1172). 2D thin-slab minimum intensity projection (TS-MinIP) and 3D volume rendered images were constructed. The same teeth were then processed by clearing and staining. For each root, images obtained from clearing, 2D, 3D and combined 2D and 3D techniques were examined independently by four endodontists and categorized according to Vertucci's classification. Fine anatomical structures such as accessory canals, intercanal communications and loops were also identified. Agreement among the four techniques for Vertucci's classification was 45.2% (14/31). The most frequent were Vertucci's type IV and then type II, although many had complex configurations that were non-classifiable. Generally, complex canal systems were more clearly visible in MCT images than with standard clearing and staining. Fine anatomical structures such as intercanal communications, accessory canals and loops were mostly detected with a combination of 2D TS-MinIP and 3D volume-rendering MCT images. Canal configurations and fine anatomic structures were more clearly observed in the combined 2D and 3D MCT images than the clearing technique. The frequency of non-classifiable configurations demonstrated the complexity of mandibular first molar mesial root canal anatomy.

Cytotoxic withanolides from Physalis angulata.

PubMed

Gao, Caiyun; Li, Ruijun; Zhou, Miaomiao; Yang, Yanwei; Kong, Lingyi; Luo, Jun

2018-03-01

A new withanolide (1), physagulide P, together with five known withanolides (2-6), was isolated from the aerial parts of Physalis angulata L. The structure of new compound was elucidated on the basis of extensive spectroscopic techniques, including 1D, 2D NMR and HRESIMS. The activity screening indicated that compound 1 showed significant cytotoxicities against the human osteosarcoma cell line MG-63, HepG-2 hepatoma cells and breast cancer cells MDA-MB-231 with the IC 50 value of 3.50, 4.22 and 15.74 μM.

Four new compounds from Imperata cylindrica.

PubMed

Liu, Xuan; Zhang, Bin-Feng; Yang, Li; Chou, Gui-Xin; Wang, Zheng-Tao

2014-04-01

Four new compounds, impecylone (1), deacetylimpecyloside (2), seguinoside K 4-methylether (3) and impecylenolide (4), were isolated from Imperata cylindrica along with two known compounds, impecyloside (5) and seguinoside K (6). Their structures were elucidated mainly by spectroscopic analyses including 1D- and 2D-NMR techniques, and the absolute configuration of 1 was confirmed by X-ray diffraction analysis. In calcium assay, the result indicated that compounds 1, 2, 4 and 5 cannot obviously inhibit the calcium peak value compared with the negative control, and suggested that the four compounds could not have anti-inflammatory activity.

Image interpolation by adaptive 2-D autoregressive modeling and soft-decision estimation.

PubMed

Zhang, Xiangjun; Wu, Xiaolin

2008-06-01

The challenge of image interpolation is to preserve spatial details. We propose a soft-decision interpolation technique that estimates missing pixels in groups rather than one at a time. The new technique learns and adapts to varying scene structures using a 2-D piecewise autoregressive model. The model parameters are estimated in a moving window in the input low-resolution image. The pixel structure dictated by the learnt model is enforced by the soft-decision estimation process onto a block of pixels, including both observed and estimated. The result is equivalent to that of a high-order adaptive nonseparable 2-D interpolation filter. This new image interpolation approach preserves spatial coherence of interpolated images better than the existing methods, and it produces the best results so far over a wide range of scenes in both PSNR measure and subjective visual quality. Edges and textures are well preserved, and common interpolation artifacts (blurring, ringing, jaggies, zippering, etc.) are greatly reduced.

Biochemical validity of imaging techniques (X-ray, MRI, and dGEMRIC) in degenerative disc disease of the human cervical spine-an in vivo study.

PubMed

Bostelmann, Richard; Bostelmann, Tamara; Nasaca, Adrian; Steiger, Hans Jakob; Zaucke, Frank; Schleich, Christoph

2017-02-01

On a molecular level, maturation or degeneration of human intervertebral disc is among others expressed by the content of glycosaminoglycans (GAGs). According to the degenerative status, the disc content can differ in nucleus pulposus (NP) and annulus fibrosus (AF), respectively. Research in this area was conducted mostly on postmortem samples. Although several radiological classification systems exist, none includes biochemical features. Therefore, we focused our in vivo study on a widely spread and less expensive imaging technique for the cervical spine and the correlation of radiological patterns to biochemical equivalents in the intervertebral discs. The aim of this pilot study was to (1) measure the GAG content in human cervical discs, (2) to investigate whether a topographic biochemical GAG pattern can be found, and (3) whether there is a correlation between imaging data (X-ray and magnetic resonance imaging [MRI] including delayed gadolinium-enhanced MRI of cartilage [dGEMRIC] as a special imaging technique of cartilage) and the biochemical data. We conducted a prospective experimental pilot study. Only non-responders to conservative therapy were included. All subjects were physically and neurologically examined, and they completed their questionnaires. Visual analogue scale neck and arm, Neck Disability Index score, radiological parameters (X-rays, MRI, dGEMRIC), and the content of GAG in the cervical disc were assessed. After surgical removal of 12 discs, 96 fractions of AF and NP were biochemically analyzed for the GAG content using dimethylmethylene blue assay. A quantitative pattern of GAGs in the human cervical disc was identified. There were (1) significantly (p<.001) higher values of GAGs (µg GAG/mg tissue) in the NP (169.9 SD 37.3) compared with the AF (132.4 SD 42.2), and (2) significantly (p<.005) higher values of GAGs in the posterior (right/left: 149.9/160.2) compared with the anterior (right/left: 112.0/120.2) part of the AF. Third, we found in dGEMRIC imaging a significantly (p<.008) different distribution of GAGs in the cervical disc (NP 1083.3 ms [SD 248.6], AF 925.9 ms [SD 137.6]). Finally, we found that grading of disc degeneration in X-ray and MRI was significantly correlated with neither AF- nor NP-GAG content. The GAG content in human cervical discs can be detected in vivo and is subject to a significantly (p<.05) region-specific pattern (AF vs. NP; anterior vs. posterior in the AF). Up to the levels of AF and NP, this is reproducible in MRI in dGEMRIC technique, but not in X-ray or standard MRI sequences. Potentially, the MRI in dGEMRIC technique can be used as a non-invasive in vivo indicator for disc degeneration in the cervical spine. Copyright © 2016 Elsevier Inc. All rights reserved.

Atomic force microscopy for two-dimensional materials: A tutorial review

NASA Astrophysics Data System (ADS)

Zhang, Hang; Huang, Junxiang; Wang, Yongwei; Liu, Rui; Huai, Xiulan; Jiang, Jingjing; Anfuso, Chantelle

2018-01-01

Low dimensional materials exhibit distinct properties compared to their bulk counterparts. A plethora of examples have been demonstrated in two-dimensional (2-D) materials, including graphene and transition metal dichalcogenides (TMDCs). These novel and intriguing properties at the nano-, molecular- and even monatomic scales have triggered tremendous interest and research, from fundamental studies to practical applications and even device fabrication. The unique behaviors of 2-D materials result from the special structure-property relationships that exist between surface topographical variations and mechanical responses, electronic structures, optical characteristics, and electrochemical properties. These relationships are generally convoluted and sensitive to ambient and external perturbations. Characterizing these systems thus requires techniques capable of providing multidimensional information under controlled environments, such as atomic force microscopy (AFM). Today, AFM plays a key role in exploring the basic principles underlying the functionality of 2-D materials. In this tutorial review, we provide a brief introduction to some of the unique properties of 2-D materials, followed by a summary of the basic principles of AFM and the various AFM modes most appropriate for studying these systems. Following that, we will focus on five important properties of 2-D materials and their characterization in more detail, including recent literature examples. These properties include nanomechanics, nanoelectromechanics, nanoelectrics, nanospectroscopy, and nanoelectrochemistry.

Soft Robotic Manipulation and Locomotion with a 3D Printed Electroactive Hydrogel.

PubMed

Han, Daehoon; Farino, Cindy; Yang, Chen; Scott, Tracy; Browe, Daniel; Choi, Wonjoon; Freeman, Joseph W; Lee, Howon

2018-05-30

Electroactive hydrogels (EAH) that exhibit large deformation in response to an electric field have received great attention as a potential actuating material for soft robots and artificial muscle. However, their application has been limited due to the use of traditional two-dimensional (2D) fabrication methods. Here we present soft robotic manipulation and locomotion with 3D printed EAH microstructures. Through 3D design and precise dimensional control enabled by a digital light processing (DLP) based micro 3D printing technique, complex 3D actuations of EAH are achieved. We demonstrate soft robotic actuations including gripping and transporting an object and a bidirectional locomotion.

Poster — Thur Eve — 45: Comparison of different Monte Carlo methods of scoring linear energy transfer in modulated proton therapy beams

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

Granville, DA; Sawakuchi, GO

2014-08-15

In this work, we demonstrate inconsistencies in commonly used Monte Carlo methods of scoring linear energy transfer (LET) in proton therapy beams. In particle therapy beams, the LET is an important parameter because the relative biological effectiveness (RBE) depends on it. LET is often determined using Monte Carlo techniques. We used a realistic Monte Carlo model of a proton therapy nozzle to score proton LET in spread-out Bragg peak (SOBP) depth-dose distributions. We used three different scoring and calculation techniques to determine average LET at varying depths within a 140 MeV beam with a 4 cm SOBP and a 250more » MeV beam with a 10 cm SOBP. These techniques included fluence-weighted (Φ-LET) and dose-weighted average (D-LET) LET calculations from: 1) scored energy spectra converted to LET spectra through a lookup table, 2) directly scored LET spectra and 3) accumulated LET scored ‘on-the-fly’ during simulations. All protons (primary and secondary) were included in the scoring. Φ-LET was found to be less sensitive to changes in scoring technique than D-LET. In addition, the spectral scoring methods were sensitive to low-energy (high-LET) cutoff values in the averaging. Using cutoff parameters chosen carefully for consistency between techniques, we found variations in Φ-LET values of up to 1.6% and variations in D-LET values of up to 11.2% for the same irradiation conditions, depending on the method used to score LET. Variations were largest near the end of the SOBP, where the LET and energy spectra are broader.« less

[New mammography technologies and their impact on radiation dose].

PubMed

Chevalier del Rio, M

2013-12-01

This article reviews new mammography technologies resulting from advances in digital detectors and processing techniques. Most are just starting to be commercialized or are in the clinical trial phase. The results of clinical trials with the new 2D techniques (contrast-enhanced techniques or stereotactic techniques) show they are useful for diagnosing cancer. However, the greater complexity of the image acquisition process suggests that their use will be limited to particular cases such as inconclusive lesions or women with high risk for developing breast cancer. Among the 3D technologies (breast tomography and breast tomosynthesis), only breast tomosynthesis has been implemented in clinical practice, so it is the only technique for which it is possible to know the sensitivity, specificity, and radiation dose delivered. This article describes the principles underlying the way breast tomosynthesis works and the techniques used for image acquisition and reconstruction. It also summarizes the main results obtained in clinical studies, which generally show that breast tomosynthesis increases the breast cancer detection rate while decreasing the recall rate and number of biopsies taken. The protocol for breast tomosynthesis approved by the Food and Drug Administration (USA) consists of two conventional mammography projections for each breast and two tomosynthesis projections for each breast. This means multiplying the risks of inducing cancer and death associated with 2D mammography by a factor between 2 and 3 (2.6-3.3 and 0.7-0.9 per 100,000 women exposed when 50 years old, respectively). The protocol for breast tomosynthesis examinations is one of the aspects that is essential to determine when including tomosynthesis in screening programs and routine breast imaging. Copyright © 2013 SERAM. Published by Elsevier Espana. All rights reserved.

Results of endocapsular phacofracture debulking of hard cataracts

PubMed Central

Davison, James A

2015-01-01

Purpose/aim of the study To present a phacoemulsification technique for hard cataracts and compare postoperative results using two different ultrasonic tip motions during quadrant removal. Materials and methods A phacoemulsification technique which employs in situ fracture and endocapsular debulking for hard cataracts is presented. The prospective study included 56 consecutive cases of hard cataract (LOCS III NC [Lens Opacification Classification System III, nuclear color], average 4.26), which were operated using the Infiniti machine and the Partial Kelman tip. Longitudinal tip movement was used for sculpting for all cases which were randomized to receive longitudinal or torsional/interjected longitudinal (Intelligent Phaco [IP]) strategies for quadrant removal. Measurements included cumulative dissipated energy (CDE), 3 months postoperative surgically induced astigmatism (SIA), and corneal endothelial cell density (ECD) losses. Results No complications were recorded in any of the cases. Respective overall and longitudinal vs IP means were as follows: CDE, 51.6±15.6 and 55.7±15.5 vs 48.6±15.1; SIA, 0.36±0.2 D and 0.4±0.2 D vs 0.3±0.2 D; and mean ECD loss, 4.1%±10.8% and 5.9%±13.4% vs 2.7%±7.8%. The differences between longitudinal and IP were not significant for any of the three categories. Conclusion The endocapsular phacofracture debulking technique is safe and effective for phacoemulsification of hard cataracts using longitudinal or torsional IP strategies for quadrant removal with the Infiniti machine and Partial Kelman tip. PMID:26203213

What Have Metabolomics Approaches Taught Us About Type 2 Diabetes?

PubMed

Gonzalez-Franquesa, Alba; Burkart, Alison M; Isganaitis, Elvira; Patti, Mary-Elizabeth

2016-08-01

Type 2 diabetes (T2D) is increasing worldwide, making identification of biomarkers for detection, staging, and effective prevention strategies an especially critical scientific and medical goal. Fortunately, advances in metabolomics techniques, together with improvements in bioinformatics and mathematical modeling approaches, have provided the scientific community with new tools to describe the T2D metabolome. The metabolomics signatures associated with T2D and obesity include increased levels of lactate, glycolytic intermediates, branched-chain and aromatic amino acids, and long-chain fatty acids. Conversely, tricarboxylic acid cycle intermediates, betaine, and other metabolites decrease. Future studies will be required to fully integrate these and other findings into our understanding of diabetes pathophysiology and to identify biomarkers of disease risk, stage, and responsiveness to specific treatments.

The use of graphene based materials for fuel cell, photovoltaics, and supercapacitor electrode materials

NASA Astrophysics Data System (ADS)

Tsang, Alpha C. H.; Kwok, Holly Y. H.; Leung, Dennis Y. C.

2017-05-01

This manuscript presents the methodology of the production of 2D and 3D graphene based material, and their applications in fuel cell, supercapacitor, and photovoltic in recent years. Due to the uniqueness and attractive properties of graphene nanosheets, a large number of techniques have been developed for raw graphene preparation, from a chemical method to a physical deposition of carbon vapor under extreme conditions. A variety of graphene based materials were also prepared from raw graphene or graphene oxide, including the metal loaded, metal oxides loaded, to the foreign elements doped graphene. Both two-dimensional (2D) to three-dimensional (3D) structured graphene were covered. These materials included the bulk or template hybrid composite, containing graphene hydrogel, graphene aerogel, or graphene foam and its derived products. They were widely used in green energy device research, which exhibited strong activity, and developed some special usage in recent research.

A new bis-labdanic diterpene from the rhizomes of Alpinia pahangensis.

PubMed

Sivasothy, Yasodha; Ibrahim, Halijah; Paliany, Audra Shaleena; Alias, Siti Aisyah; Md Nor, Nurur Raudzah; Awang, Khalijah

2013-12-01

The rhizomes of Alpinia pahangensis yielded a new bis-labdanic diterpene for which the name pahangensin C (1) was proposed along with twelve known analogues (2-13). The structure of 1 was elucidated via spectroscopic methods including 1D and 2D NMR techniques and LCMS-IT-TOF analysis. Compounds 2 and 12 were isolated for the first time from the genus Alpinia. This is the second occurrence of compounds 2 and 12 in the Zingiberaceae family. Selected analogues exhibited moderate to strong inhibitory activity against Staphylococcus aureus and Bacillus cereus. Georg Thieme Verlag KG Stuttgart · New York.

Alternative methods of refraction: a comparison of three techniques.

PubMed

Smith, Kyla; Weissberg, Erik; Travison, Thomas G

2010-03-01

In the developing world, refractive error is a common untreated cause of visual impairment. Lay people may use portable tools to overcome this issue. This study compares three methods of measuring spherical refractive error (SE) performed by a lay technician to a subjective refraction (SR) in a controlled clinical setting and a field trial. Fifty subjects from Boston, MA (mean age, 24.3 y ± 1.5) and 50 from Nicaragua (mean age, 40 y ± 13.7) were recruited. Measures (performed on right eye only) included (1) AdSpecs, adjustable spectacles; (2) Focometer, focusable telescope; (3) Predetermined Lens Refraction (PLR), prescripted lens choices; (4) SR. Examiners were masked and techniques randomized. Student t-test compared mean SE determined by each method (95% confidence intervals). AdSpecs repeatability was evaluated by repeating measures of SE and visual acuity (VA). Mean (SD) SE for Boston subjects determined by SR was -2.46 D (3.2). Mean (SD) SE for AdSpecs, Focometer -2.41 D (2.69), -2.80 D (2.82). Among the 30 Boston subjects considered in analyses of PLR data (see Methods), PLR and SR obtained mean (SD) values of -0.65 D (1.36) and -0.41 D (1.67), respectively, a statistically significant difference of -0.24 D (p = 0.046, t = 2.09). Mean PLR SE had greatest deviation from SR, 0.67 D. 20/20 VA was achieved by SR, AdSpecs, Focometer, and PLR in 98, 88, 84, 96% of subjects. Mean (SD) SE for Nicaragua subjects determined by SR was +0.51 D (0.71). Mean (SD) SE for AdSpecs, Focometer, and PLR was +0.68 D (0.83), +0.42 D (1.13), +0.27 D (0.79). Mean PLR SE had the greatest deviation from the SR by 0.24 D, which was a statistically significant difference. 20/20 VA was achieved by SR, AdSpecs, Focometer, and PLR in 78, 66, 66, 88% of subjects. Repeated measures by AdSpecs were highly correlated. Although the mean value obtained by each technique may be similar to that obtained by SR, substantial and clinically meaningful differences may exist in some individuals; however, where SR is unavailable they could be a feasible alternative.

2D DOST based local phase pattern for face recognition

NASA Astrophysics Data System (ADS)

Moniruzzaman, Md.; Alam, Mohammad S.

2017-05-01

A new two dimensional (2-D) Discrete Orthogonal Stcokwell Transform (DOST) based Local Phase Pattern (LPP) technique has been proposed for efficient face recognition. The proposed technique uses 2-D DOST as preliminary preprocessing and local phase pattern to form robust feature signature which can effectively accommodate various 3D facial distortions and illumination variations. The S-transform, is an extension of the ideas of the continuous wavelet transform (CWT), is also known for its local spectral phase properties in time-frequency representation (TFR). It provides a frequency dependent resolution of the time-frequency space and absolutely referenced local phase information while maintaining a direct relationship with the Fourier spectrum which is unique in TFR. After utilizing 2-D Stransform as the preprocessing and build local phase pattern from extracted phase information yield fast and efficient technique for face recognition. The proposed technique shows better correlation discrimination compared to alternate pattern recognition techniques such as wavelet or Gabor based face recognition. The performance of the proposed method has been tested using the Yale and extended Yale facial database under different environments such as illumination variation and 3D changes in facial expressions. Test results show that the proposed technique yields better performance compared to alternate time-frequency representation (TFR) based face recognition techniques.

Molecular methods (digital PCR and real-time PCR) for the quantification of low copy DNA of Phytophthora nicotianae in environmental samples.

PubMed

Blaya, Josefa; Lloret, Eva; Santísima-Trinidad, Ana B; Ros, Margarita; Pascual, Jose A

2016-04-01

Currently, real-time polymerase chain reaction (qPCR) is the technique most often used to quantify pathogen presence. Digital PCR (dPCR) is a new technique with the potential to have a substantial impact on plant pathology research owing to its reproducibility, sensitivity and low susceptibility to inhibitors. In this study, we evaluated the feasibility of using dPCR and qPCR to quantify Phytophthora nicotianae in several background matrices, including host tissues (stems and roots) and soil samples. In spite of the low dynamic range of dPCR (3 logs compared with 7 logs for qPCR), this technique proved to have very high precision applicable at very low copy numbers. The dPCR was able to detect accurately the pathogen in all type of samples in a broad concentration range. Moreover, dPCR seems to be less susceptible to inhibitors than qPCR in plant samples. Linear regression analysis showed a high correlation between the results obtained with the two techniques in soil, stem and root samples, with R(2) = 0.873, 0.999 and 0.995 respectively. These results suggest that dPCR is a promising alternative for quantifying soil-borne pathogens in environmental samples, even in early stages of the disease. © 2015 Society of Chemical Industry.

Validation of a motion-robust 2D sequential technique for quantification of hepatic proton density fat fraction during free breathing.

PubMed

Pooler, B Dustin; Hernando, Diego; Ruby, Jeannine A; Ishii, Hiroshi; Shimakawa, Ann; Reeder, Scott B

2018-04-17

Current chemical-shift-encoded (CSE) MRI techniques for measuring hepatic proton density fat fraction (PDFF) are sensitive to motion artifacts. Initial validation of a motion-robust 2D-sequential CSE-MRI technique for quantification of hepatic PDFF. Phantom study and prospective in vivo cohort. Fifty adult patients (27 women, 23 men, mean age 57.2 years). 3D, 2D-interleaved, and 2D-sequential CSE-MRI acquisitions at 1.5T. Three CSE-MRI techniques (3D, 2D-interleaved, 2D-sequential) were performed in a PDFF phantom and in vivo. Reference standards were 3D CSE-MRI PDFF measurements for the phantom study and single-voxel MR spectroscopy hepatic PDFF measurements (MRS-PDFF) in vivo. In vivo hepatic MRI-PDFF measurements were performed during a single breath-hold (BH) and free breathing (FB), and were repeated by a second reader for the FB 2D-sequential sequence to assess interreader variability. Correlation plots to validate the 2D-sequential CSE-MRI against the phantom and in vivo reference standards. Bland-Altman analysis of FB versus BH CSE-MRI acquisitions to evaluate robustness to motion. Bland-Altman analysis to assess interreader variability. Phantom 2D-sequential CSE-MRI PDFF measurements demonstrated excellent agreement and correlation (R 2 > 0.99) with 3D CSE-MRI. In vivo, the mean (±SD) hepatic PDFF was 8.8 ± 8.7% (range 0.6-28.5%). Compared with BH acquisitions, FB hepatic PDFF measurements demonstrated bias of +0.15% for 2D-sequential compared with + 0.53% for 3D and +0.94% for 2D-interleaved. 95% limits of agreement (LOA) were narrower for 2D-sequential (±0.99%), compared with 3D (±3.72%) and 2D-interleaved (±3.10%). All CSE-MRI techniques had excellent correlation with MRS (R 2 > 0.97). The FB 2D-sequential acquisition demonstrated little interreader variability, with mean bias of +0.07% and 95% LOA of ± 1.53%. This motion-robust 2D-sequential CSE-MRI can accurately measure hepatic PDFF during free breathing in a patient population with a range of PDFF values of 0.6-28.5%, permitting accurate quantification of liver fat content without the need for suspended respiration. 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018. © 2018 International Society for Magnetic Resonance in Medicine.

Use of reconstructed 3D VMEC equilibria to match effects of toroidally rotating discharges in DIII-D

DOE PAGES

Wingen, Andreas; Wilcox, Robert S.; Cianciosa, Mark R.; ...

2016-10-13

Here, a technique for tokamak equilibrium reconstructions is used for multiple DIII-D discharges, including L-mode and H-mode cases when weakly 3D fieldsmore » $$\\left(\\delta B/B\\sim {{10}^{-3}}\\right)$$ are applied. The technique couples diagnostics to the non-linear, ideal MHD equilibrium solver VMEC, using the V3FIT code, to find the most likely 3D equilibrium based on a suite of measurements. It is demonstrated that V3FIT can be used to find non-linear 3D equilibria that are consistent with experimental measurements of the plasma response to very weak 3D perturbations, as well as with 2D profile measurements. Observations at DIII-D show that plasma rotation larger than 20 krad s –1 changes the relative phase between the applied 3D fields and the measured plasma response. Discharges with low averaged rotation (10 krad s –1) and peaked rotation profiles (40 krad s –1) are reconstructed. Similarities and differences to forward modeled VMEC equilibria, which do not include rotational effects, are shown. Toroidal phase shifts of up to $${{30}^{\\circ}}$$ are found between the measured and forward modeled plasma responses at the highest values of rotation. The plasma response phases of reconstructed equilibra on the other hand match the measured ones. This is the first time V3FIT has been used to reconstruct weakly 3D tokamak equilibria.« less

Reconciling Estimates of Cell Proliferation from Stable Isotope Labeling Experiments

PubMed Central

Drylewicz, Julia; Elemans, Marjet; Zhang, Yan; Kelly, Elizabeth; Reljic, Rajko; Tesselaar, Kiki; de Boer, Rob J.; Macallan, Derek C.; Borghans, José A. M.; Asquith, Becca

2015-01-01

Stable isotope labeling is the state of the art technique for in vivo quantification of lymphocyte kinetics in humans. It has been central to a number of seminal studies, particularly in the context of HIV-1 and leukemia. However, there is a significant discrepancy between lymphocyte proliferation rates estimated in different studies. Notably, deuterated 2H2-glucose (D2-glucose) labeling studies consistently yield higher estimates of proliferation than deuterated water (D2O) labeling studies. This hampers our understanding of immune function and undermines our confidence in this important technique. Whether these differences are caused by fundamental biochemical differences between the two compounds and/or by methodological differences in the studies is unknown. D2-glucose and D2O labeling experiments have never been performed by the same group under the same experimental conditions; consequently a direct comparison of these two techniques has not been possible. We sought to address this problem. We performed both in vitro and murine in vivo labeling experiments using identical protocols with both D2-glucose and D2O. This showed that intrinsic differences between the two compounds do not cause differences in the proliferation rate estimates, but that estimates made using D2-glucose in vivo were susceptible to difficulties in normalization due to highly variable blood glucose enrichment. Analysis of three published human studies made using D2-glucose and D2O confirmed this problem, particularly in the case of short term D2-glucose labeling. Correcting for these inaccuracies in normalization decreased proliferation rate estimates made using D2-glucose and slightly increased estimates made using D2O; thus bringing the estimates from the two methods significantly closer and highlighting the importance of reliable normalization when using this technique. PMID:26437372

Development of accurate potentials to explore the structure of water on 2D materials

NASA Astrophysics Data System (ADS)

Bejagam, Karteek; Singh, Samrendra; Deshmukh, Sanket; Deshmkuh Group Team; Samrendra Group Collaboration

Water play an important role in many biological and non-biological process. Thus structure of water at various interfaces and under confinement has always been the topic of immense interest. 2-D materials have shown great potential in surface coating applications and nanofluidic devices. However, the exact atomic level understanding of the wettability of single layer of these 2-D materials is still lacking mainly due to lack of experimental techniques and computational methodologies including accurate force-field potentials and algorithms to measure the contact angle of water. In the present study, we have developed a new algorithm to measure the accurate contact angle between water and 2-D materials. The algorithm is based on fitting the best sphere to the shape of the droplet. This novel spherical fitting method accounts for every individual molecule of the droplet, rather than those at the surface only. We employ this method of contact angle measurements to develop the accurate non-bonded potentials between water and 2-D materials including graphene and boron nitride (BN) to reproduce the experimentally observed contact angle of water on these 2-D materials. Different water models such as SPC, SPC/Fw, and TIP3P were used to study the structure of water at the interfaces.

Applying neutron transmission physics and 3D statistical full-field model to understand 2D Bragg-edge imaging

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

Xie, Qingge; Song, Gian; Gorti, Sarma B.

Bragg-edge imaging, which is also known as neutron radiography, has recently emerged as a novel crystalline characterization technique. Modelling of this novel technique by incorporating various features of the underlying microstructure (including the crystallographic texture, the morphological texture, and the grain size) of the material remains a subject of considerable research and development. In this paper, Inconel 718 samples made by additive manufacturing were investigated by neutron diffraction and neutron radiography techniques. The specimen features strong morphological and crystallographic textures and a highly heterogeneous microstructure. A 3D statistical full-field model is introduced by taking details of the microstructure into accountmore » to understand the experimental neutron radiography results. The Bragg-edge imaging and the total cross section were calculated based on the neutron transmission physics. A good match was obtained between the model predictions and experimental results at different incident beam angles with respect to the sample build direction. The current theoretical approach has the ability to incorporate 3D spatially resolved microstructural heterogeneity information and shows promise in understanding the 2D neutron radiography of bulk samples. With further development to incorporate the heterogeneity in lattice strain in the model, it can be used as a powerful tool in the future to better understand the neutron radiography data.« less

Applying neutron transmission physics and 3D statistical full-field model to understand 2D Bragg-edge imaging

DOE PAGES

Xie, Qingge; Song, Gian; Gorti, Sarma B.; ...

2018-02-21

Bragg-edge imaging, which is also known as neutron radiography, has recently emerged as a novel crystalline characterization technique. Modelling of this novel technique by incorporating various features of the underlying microstructure (including the crystallographic texture, the morphological texture, and the grain size) of the material remains a subject of considerable research and development. In this paper, Inconel 718 samples made by additive manufacturing were investigated by neutron diffraction and neutron radiography techniques. The specimen features strong morphological and crystallographic textures and a highly heterogeneous microstructure. A 3D statistical full-field model is introduced by taking details of the microstructure into accountmore » to understand the experimental neutron radiography results. The Bragg-edge imaging and the total cross section were calculated based on the neutron transmission physics. A good match was obtained between the model predictions and experimental results at different incident beam angles with respect to the sample build direction. The current theoretical approach has the ability to incorporate 3D spatially resolved microstructural heterogeneity information and shows promise in understanding the 2D neutron radiography of bulk samples. With further development to incorporate the heterogeneity in lattice strain in the model, it can be used as a powerful tool in the future to better understand the neutron radiography data.« less

Methodological development of topographic correction in 2D/3D ToF-SIMS images using AFM images

NASA Astrophysics Data System (ADS)

Jung, Seokwon; Lee, Nodo; Choi, Myungshin; Lee, Jungmin; Cho, Eunkyunng; Joo, Minho

2018-02-01

Time-of-flight secondary-ion mass spectrometry (ToF-SIMS) is an emerging technique that provides chemical information directly from the surface of electronic materials, e.g. OLED and solar cell. It is very versatile and highly sensitive mass spectrometric technique that provides surface molecular information with their lateral distribution as a two-dimensional (2D) molecular image. Extending the usefulness of ToF-SIMS, a 3D molecular image can be generated by acquiring multiple 2D images in a stack. These imaging techniques by ToF-SIMS provide an insight into understanding the complex structures of unknown composition in electronic material. However, one drawback in ToF-SIMS is not able to represent topographical information in 2D and 3D mapping images. To overcome this technical limitation, topographic information by ex-situ technique such as atomic force microscopy (AFM) has been combined with chemical information from SIMS that provides both chemical and physical information in one image. The key to combine two different images obtained from ToF-SIMS and AFM techniques is to develop the image processing algorithm, which performs resize and alignment by comparing the specific pixel information of each image. In this work, we present methodological development of the semiautomatic alignment and the 3D structure interpolation system for the combination of 2D/3D images obtained by ToF-SIMS and AFM measurements, which allows providing useful analytical information in a single representation.

3D Monitoring under the Keciova Mosque (Casbah-Algier, Algeria) with Ground Penetrating Radar Method

NASA Astrophysics Data System (ADS)

Kadioglu, Selma; Kagan Kadioglu, Yusuf; Deniz, Kiymet; Akin Akyol, Ali

2014-05-01

Keciova (Ketchaoua) Mosque, in Casbah-Algiers, the capital of Algeria, is a UNESCO World Heritage Site. Keciova Mosque was originally built in 1612 by the Ottoman Empire. A RAMAC CU II GPR system and a 250 MHz shielded antenna have been employed inside of the Mosque including the Cathedral and inside of the burial chambers under the Cathedral Site on parallel profiles spaced approximately 0.30 m apart to measure data. After applying standard two-dimensional (2D) and three dimensional (3D) imaging techniques, transparent 3D imaging techniques have been used to photograph the foundational infrastructures, buried remains and safety problems of the Mosque. The results showed that we obtained 3D GPR visualization until 12.0 m in depth. Firstly we imaged the base floor including corridors. Then we monitored buried remains under the first ground level between 5.0-7.0 m in depths. Finally we indicated 3D GPR photographs a spectacular protected buried old mosque structures under the second ground level between 9.0-12.0 m in depths. This project has been supported by Republic of Turkey Prime Ministry Turkish Cooperation and Coordination Agency (TIKA). This study is a contribution to the EU funded COST action TU1208, "Civil Engineering Applications of Ground penetrating Radar".

A technique for determining the deuterium/hydrogen contrast map in neutron macromolecular crystallography.

PubMed

Chatake, Toshiyuki; Fujiwara, Satoru

2016-01-01

A difference in the neutron scattering length between hydrogen and deuterium leads to a high density contrast in neutron Fourier maps. In this study, a technique for determining the deuterium/hydrogen (D/H) contrast map in neutron macromolecular crystallography is developed and evaluated using ribonuclease A. The contrast map between the D2O-solvent and H2O-solvent crystals is calculated in real space, rather than in reciprocal space as performed in previous neutron D/H contrast crystallography. The present technique can thus utilize all of the amplitudes of the neutron structure factors for both D2O-solvent and H2O-solvent crystals. The neutron D/H contrast maps clearly demonstrate the powerful detectability of H/D exchange in proteins. In fact, alternative protonation states and alternative conformations of hydroxyl groups are observed at medium resolution (1.8 Å). Moreover, water molecules can be categorized into three types according to their tendency towards rotational disorder. These results directly indicate improvement in the neutron crystal structure analysis. This technique is suitable for incorporation into the standard structure-determination process used in neutron protein crystallography; consequently, more precise and efficient determination of the D-atom positions is possible using a combination of this D/H contrast technique and standard neutron structure-determination protocols.

Evaluation of mathematical algorithms for automatic patient alignment in radiosurgery.

PubMed

Williams, Kenneth M; Schulte, Reinhard W; Schubert, Keith E; Wroe, Andrew J

2015-06-01

Image registration techniques based on anatomical features can serve to automate patient alignment for intracranial radiosurgery procedures in an effort to improve the accuracy and efficiency of the alignment process as well as potentially eliminate the need for implanted fiducial markers. To explore this option, four two-dimensional (2D) image registration algorithms were analyzed: the phase correlation technique, mutual information (MI) maximization, enhanced correlation coefficient (ECC) maximization, and the iterative closest point (ICP) algorithm. Digitally reconstructed radiographs from the treatment planning computed tomography scan of a human skull were used as the reference images, while orthogonal digital x-ray images taken in the treatment room were used as the captured images to be aligned. The accuracy of aligning the skull with each algorithm was compared to the alignment of the currently practiced procedure, which is based on a manual process of selecting common landmarks, including implanted fiducials and anatomical skull features. Of the four algorithms, three (phase correlation, MI maximization, and ECC maximization) demonstrated clinically adequate (ie, comparable to the standard alignment technique) translational accuracy and improvements in speed compared to the interactive, user-guided technique; however, the ICP algorithm failed to give clinically acceptable results. The results of this work suggest that a combination of different algorithms may provide the best registration results. This research serves as the initial groundwork for the translation of automated, anatomy-based 2D algorithms into a real-world system for 2D-to-2D image registration and alignment for intracranial radiosurgery. This may obviate the need for invasive implantation of fiducial markers into the skull and may improve treatment room efficiency and accuracy. © The Author(s) 2014.

Iterative metal artifact reduction: evaluation and optimization of technique.

PubMed

Subhas, Naveen; Primak, Andrew N; Obuchowski, Nancy A; Gupta, Amit; Polster, Joshua M; Krauss, Andreas; Iannotti, Joseph P

2014-12-01

Iterative metal artifact reduction (IMAR) is a sinogram inpainting technique that incorporates high-frequency data from standard weighted filtered back projection (WFBP) reconstructions to reduce metal artifact on computed tomography (CT). This study was designed to compare the image quality of IMAR and WFBP in total shoulder arthroplasties (TSA); determine the optimal amount of WFBP high-frequency data needed for IMAR; and compare image quality of the standard 3D technique with that of a faster 2D technique. Eight patients with nine TSA underwent CT with standardized parameters: 140 kVp, 300 mAs, 0.6 mm collimation and slice thickness, and B30 kernel. WFBP, three 3D IMAR algorithms with different amounts of WFBP high-frequency data (IMARlo, lowest; IMARmod, moderate; IMARhi, highest), and one 2D IMAR algorithm were reconstructed. Differences in attenuation near hardware and away from hardware were measured and compared using repeated measures ANOVA. Five readers independently graded image quality; scores were compared using Friedman's test. Attenuation differences were smaller with all 3D IMAR techniques than with WFBP (p < 0.0063). With increasing high-frequency data, the attenuation difference increased slightly (differences not statistically significant). All readers ranked IMARmod and IMARhi more favorably than WFBP (p < 0.05), with IMARmod ranked highest for most structures. The attenuation difference was slightly higher with 2D than with 3D IMAR, with no significant reader preference for 3D over 2D. IMAR significantly decreases metal artifact compared to WFBP both objectively and subjectively in TSA. The incorporation of a moderate amount of WFBP high-frequency data and use of a 2D reconstruction technique optimize image quality and allow for relatively short reconstruction times.

Consistency between 2D-3D Sediment Transport models

NASA Astrophysics Data System (ADS)

Villaret, Catherine; Jodeau, Magali

2017-04-01

Sediment transport models have been developed and applied by the engineering community to estimate transport rates and morphodynamic bed evolutions in river flows, coastal and estuarine conditions. Environmental modelling systems like the open-source Telemac modelling system include a hierarchy of models from 1D (Mascaret), 2D (Telemac-2D/Sisyphe) and 3D (Telemac-3D/Sedi-3D) and include a wide range of processes to represent sediment flow interactions under more and more complex situations (cohesive, non-cohesive and mixed sediment). Despite some tremendous progresses in the numerical techniques and computing resources, the quality/accuracy of model results mainly depend on the numerous choices and skills of the modeler. In complex situations involving stratification effects, complex geometry, recirculating flows… 2D model assumptions are no longer valid. A full 3D turbulent flow model is then required in order to capture the vertical mixing processes and to represent accurately the coupled flow/sediment distribution. However a number of theoretical and numerical difficulties arise when dealing with sediment transport modelling in 3D which will be high-lighted : (1) Dependency of model results to the vertical grid refinement and choice of boundary conditions and numerical scheme (2) The choice of turbulence model determines also the sediment vertical distribution which is governed by a balance between the downward settling term and upward turbulent diffusion. (3) The use of different numerical schemes for both hydrodynamics (mean and turbulent flow) and sediment transport modelling can lead to some inconsistency including a mismatch in the definition of numerical cells and definition of boundary conditions. We discuss here those present issues and present some detailed comparison between 2D and 3D simulations on a set of validation test cases which are available in the Telemac 7.2 release using both cohesive and non-cohesive sediments.

A novel high-frequency encoding algorithm for image compression

NASA Astrophysics Data System (ADS)

Siddeq, Mohammed M.; Rodrigues, Marcos A.

2017-12-01

In this paper, a new method for image compression is proposed whose quality is demonstrated through accurate 3D reconstruction from 2D images. The method is based on the discrete cosine transform (DCT) together with a high-frequency minimization encoding algorithm at compression stage and a new concurrent binary search algorithm at decompression stage. The proposed compression method consists of five main steps: (1) divide the image into blocks and apply DCT to each block; (2) apply a high-frequency minimization method to the AC-coefficients reducing each block by 2/3 resulting in a minimized array; (3) build a look up table of probability data to enable the recovery of the original high frequencies at decompression stage; (4) apply a delta or differential operator to the list of DC-components; and (5) apply arithmetic encoding to the outputs of steps (2) and (4). At decompression stage, the look up table and the concurrent binary search algorithm are used to reconstruct all high-frequency AC-coefficients while the DC-components are decoded by reversing the arithmetic coding. Finally, the inverse DCT recovers the original image. We tested the technique by compressing and decompressing 2D images including images with structured light patterns for 3D reconstruction. The technique is compared with JPEG and JPEG2000 through 2D and 3D RMSE. Results demonstrate that the proposed compression method is perceptually superior to JPEG with equivalent quality to JPEG2000. Concerning 3D surface reconstruction from images, it is demonstrated that the proposed method is superior to both JPEG and JPEG2000.

Electronic and Optoelectronic Applications Based on 2D Novel Anisotropic Transition Metal Dichalcogenides.

PubMed

Gong, Chuanhui; Zhang, Yuxi; Chen, Wei; Chu, Junwei; Lei, Tianyu; Pu, Junru; Dai, Liping; Wu, Chunyang; Cheng, Yuhua; Zhai, Tianyou; Li, Liang; Xiong, Jie

2017-12-01

With the continuous exploration of 2D transition metal dichalcogenides (TMDs), novel high-performance devices based on the remarkable electronic and optoelectronic natures of 2D TMDs are increasingly emerging. As fresh blood of 2D TMD family, anisotropic MTe 2 and ReX 2 (M = Mo, W, and X = S, Se) have drawn increasing attention owing to their low-symmetry structures and charming properties of mechanics, electronics, and optoelectronics, which are suitable for the applications of field-effect transistors (FETs), photodetectors, thermoelectric and piezoelectric applications, especially catering to anisotropic devices. Herein, a comprehensive review is introduced, concentrating on their recent progresses and various applications in recent years. First, the crystalline structure and the origin of the strong anisotropy characterized by various techniques are discussed. Specifically, the preparation of these 2D materials is presented and various growth methods are summarized. Then, high-performance applications of these anisotropic TMDs, including FETs, photodetectors, and thermoelectric and piezoelectric applications are discussed. Finally, the conclusion and outlook of these applications are proposed.

Rapid 2D-to-3D conversion

NASA Astrophysics Data System (ADS)

Harman, Philip V.; Flack, Julien; Fox, Simon; Dowley, Mark

2002-05-01

The conversion of existing 2D images to 3D is proving commercially viable and fulfills the growing need for high quality stereoscopic images. This approach is particularly effective when creating content for the new generation of autostereoscopic displays that require multiple stereo images. The dominant technique for such content conversion is to develop a depth map for each frame of 2D material. The use of a depth map as part of the 2D to 3D conversion process has a number of desirable characteristics: 1. The resolution of the depth may be lower than that of the associated 2D image. 2. It can be highly compressed. 3. 2D compatibility is maintained. 4. Real time generation of stereo, or multiple stereo pairs, is possible. The main disadvantage has been the laborious nature of the manual conversion techniques used to create depth maps from existing 2D images, which results in a slow and costly process. An alternative, highly productive technique has been developed based upon the use of Machine Leaning Algorithm (MLAs). This paper describes the application of MLAs to the generation of depth maps and presents the results of the commercial application of this approach.

A new coherent demodulation technique for land-mobile satellite communications

NASA Technical Reports Server (NTRS)

Yoshida, Shousei; Tomita, Hideho

1990-01-01

An advanced coherent demodulation technique is described for land mobile satellite (LMS) communications. The proposed technique features a combined narrow/wind band dual open loop carrier phase estimator, which is effectively able to compensate the fast carrier phase fluctuation by fading with sacrificing a phase slip rate. Also included is the realization of quick carrier and clock reacquisition after shadowing by taking open loop structure. Its bit error rate (BER) performance is superior to that of existing detection schemes, showing a BER of 1 x 10(exp -2) at 6.3 dB E sub b/N sub o over the Rician channel with 10 dB C/M and 200 Hz (1/16 modulation rate) fading pitch f sub d for QPSK. The proposed scheme consists of a fast response carrier recovery and a quick bit timing recovery with an interpolation. An experimental terminal model was developed to evaluate its performance at fading conditions. The results are quite satisfactory, giving prospects for future LMS applications.

Measurement and image processing evaluation of surface modifications of dental implants G4 pure titanium created by different techniques

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

Bulutsuz, A. G., E-mail: asligunaya@gmail.com; Demircioglu, P., E-mail: pinar.demircioglu@adu.edu.tr; Bogrekci, I., E-mail: ismail.bogrekci@adu.edu.tr

Foreign substances and organic tissue interaction placed into the jaw in order to eliminate tooth loss involves a highly complex process. Many biological reactions take place as well as the biomechanical forces that influence this formation. Osseointegration denotes to the direct structural and functional association between the living bone and the load-bearing artificial implant's surface. Taking into consideration of the requirements in the manufacturing processes of the implants, surface characterizations with high precise measurement techniques are investigated and thus long-term success of dental implant is emphasized on the importance of these processes in this study. In this research, the detailedmore » surface characterization was performed to identify the dependence of the manufacturing techniques on the surface properties by using the image processing methods and using the scanning electron microscope (SEM) for morphological properties in 3D and Taylor Hobson stylus profilometer for roughness properties in 2D. Three implant surfaces fabricated by different manufacturing techniques were inspected, and a machined surface was included into the study as a reference specimen. The results indicated that different surface treatments were strongly influenced surface morphology. Thus 2D and 3D precise inspection techniques were highlighted on the importance for surface characterization. Different image analyses techniques such as Dark-light technique were used to verify the surface measurement results. The computational phase was performed using image processing toolbox in Matlab with precise evaluation of the roughness for the implant surfaces. The relationship between the number of black and white pixels and surface roughness is presented. FFT image processing and analyses results explicitly imply that the technique is useful in the determination of surface roughness. The results showed that the number of black pixels in the image increases with increase in surface roughness.« less

Atherosclerosis imaging using 3D black blood TSE SPACE vs 2D TSE

PubMed Central

Wong, Stephanie K; Mobolaji-Iawal, Motunrayo; Arama, Leron; Cambe, Joy; Biso, Sylvia; Alie, Nadia; Fayad, Zahi A; Mani, Venkatesh

2014-01-01

AIM: To compare 3D Black Blood turbo spin echo (TSE) sampling perfection with application-optimized contrast using different flip angle evolution (SPACE) vs 2D TSE in evaluating atherosclerotic plaques in multiple vascular territories. METHODS: The carotid, aortic, and femoral arterial walls of 16 patients at risk for cardiovascular or atherosclerotic disease were studied using both 3D black blood magnetic resonance imaging SPACE and conventional 2D multi-contrast TSE sequences using a consolidated imaging approach in the same imaging session. Qualitative and quantitative analyses were performed on the images. Agreement of morphometric measurements between the two imaging sequences was assessed using a two-sample t-test, calculation of the intra-class correlation coefficient and by the method of linear regression and Bland-Altman analyses. RESULTS: No statistically significant qualitative differences were found between the 3D SPACE and 2D TSE techniques for images of the carotids and aorta. For images of the femoral arteries, however, there were statistically significant differences in all four qualitative scores between the two techniques. Using the current approach, 3D SPACE is suboptimal for femoral imaging. However, this may be due to coils not being optimized for femoral imaging. Quantitatively, in our study, higher mean total vessel area measurements for the 3D SPACE technique across all three vascular beds were observed. No significant differences in lumen area for both the right and left carotids were observed between the two techniques. Overall, a significant-correlation existed between measures obtained between the two approaches. CONCLUSION: Qualitative and quantitative measurements between 3D SPACE and 2D TSE techniques are comparable. 3D-SPACE may be a feasible approach in the evaluation of cardiovascular patients. PMID:24876923

Low-cost Volumetric Ultrasound by Augmentation of 2D Systems: Design and Prototype.

PubMed

Herickhoff, Carl D; Morgan, Matthew R; Broder, Joshua S; Dahl, Jeremy J

2018-01-01

Conventional two-dimensional (2D) ultrasound imaging is a powerful diagnostic tool in the hands of an experienced user, yet 2D ultrasound remains clinically underutilized and inherently incomplete, with output being very operator dependent. Volumetric ultrasound systems can more fully capture a three-dimensional (3D) region of interest, but current 3D systems require specialized transducers, are prohibitively expensive for many clinical departments, and do not register image orientation with respect to the patient; these systems are designed to provide improved workflow rather than operator independence. This work investigates whether it is possible to add volumetric 3D imaging capability to existing 2D ultrasound systems at minimal cost, providing a practical means of reducing operator dependence in ultrasound. In this paper, we present a low-cost method to make 2D ultrasound systems capable of quality volumetric image acquisition: we present the general system design and image acquisition method, including the use of a probe-mounted orientation sensor, a simple probe fixture prototype, and an offline volume reconstruction technique. We demonstrate initial results of the method, implemented using a Verasonics Vantage research scanner.

3-D Vision Techniques for Autonomous Vehicles

DTIC Science & Technology

1988-08-01

TITLE (Include Security Classification) W 3-D Vision Techniques for Autonomous Vehicles 12 PERSONAL AUTHOR(S) Martial Hebert, Takeo Kanade, inso Kweoni... Autonomous Vehicles Martial Hebert, Takeo Kanade, Inso Kweon CMU-RI-TR-88-12 The Robotics Institute Carnegie Mellon University Acession For Pittsburgh

Outcome and safety analysis of 3D printed patient specific pedicle screw jigs for complex spinal deformities: A comparative study.

PubMed

Garg, Bhavuk; Gupta, Manish; Singh, Menaka; Kalyanasundaram, Dinesh

2018-05-03

Spinal deformities are very challenging to treat and have a great risk of neurological complications due to hardware placement during corrective surgery. Various techniques have been introduced to ensure safe and accurate placement of pedicle screws. Patient-specific screw guides with pre-drawn and pre-validated trajectory seems to be an attractive option. We have focused on developing 3D printing technique for complex spinal deformities in India. This study also aimed to compare the placement of pedicle screw with 3D printing and free hand technique. This is a retrospective comparative clinical study at an academic institutional setting. A total of 20 patients were enrolled during the study, 10 were operated with the help of 3D printing (group 1) and 10 were operated with freehand technique (group 2). Group 1 included 6 congenital, 3 adolescent idiopathic scoliosis (AIS), one post tubercular kyphosis and Group 2 included 5 congenital, 4 AIS and one post tubercular kyphosis patient. Primary outcomes were measured in terms of screw violation and secondary outcome were measured in terms of Surgical time, Blood loss, Radiation exposure (no. of shoots required) and complications. MIMICS v18.0 Software was used for 3D reconstruction from CT scan images of all the patients. 3-Matic software was used to create drill guide. 3-D printer from Stratasys Mojo ABS P 430 model material cartilage (a thermoplastic material) was used for printing of vertebrae model and jigs. Two sample test of proportion was used to compare correctly and wrongly pedicle screw placement with 3D printing and freehand technique. T-test with equal variance was used for operating surgical time and blood loss. This work was carried out by collaboration of Orthopaedics Department, All India Institute of Medical Sciences (AIIMS), New Delhi and Biomedical Engineering Department, Indian Institute of Technology (IIT) Delhi. This project received the grant of USD 60000 from Department of Biotechnology (DBT), Government of India under DBT Innovative young Biotechnologist Award. No study-specific conflicts of interest-associated biases is declared by the authors. No superior or inferior screw violation was observed in any of our patients in either group. We found significant (p=0.03) difference between 2 groups regarding perfect screw placement in favour of 3D printing. There were 13 grade 2 medial perforations in free hand group and 3 in 3D printing group. There was no grade 3 medial perforation in either group. There were 6 grade 2 lateral perforations in free hand group and 7 in 3D printing group were observed. There were 3 grade 3 lateral perforation in free hand group and 2 in 3D printing group were observed. Analysis showed a statistically significant (p-value: 0.005) medial violation in free hand group. Surgical time was significantly (p-value: 0.03) less in 3D printing group as compared to free hand group. Mean Blood loss was higher in free hand group, however it was not statistically significant (p-value: 0.3) in 3D printing group. Fluoroscopic shots required were less in number in 3D printing group in comparison to free hand group. There was no neurological deficit in any of the patient in any group. In our study, focusing on spinal deformities statistically significant higher rate of accurate screw positioning and higher number of inserted screws with 3D printing was possible due to enhanced safety particularly at apical levels. As such, spinal deformities are difficult to treat worldwide. In India, these deformities are often neglected and present at a very late and much more deformed state when their treatment becomes even more challenging. Developing these patient specific drill templates will enable an average spine surgeon to treat these patients with much ease and safety. Copyright © 2018. Published by Elsevier Inc.

A novel assay for detecting antibodies to cytochrome P4502D6, the molecular target of liver kidney microsomal antibody type 1.

PubMed

Kerkar, N; Ma, Y; Hussain, M; Muratori, L; Targett, C; Williams, R; Bianchi, F B; Mieli-Vergani, G; Vergani, D

1999-03-04

Liver Kidney Microsomal type 1 (LKM1) antibody, the diagnostic marker of autoimmune hepatitis type 2, is also found in a proportion of patients with hepatitis C virus infection (HCV). It is detected conventionally by the subjective immunofluorescence technique. Our aim was to establish a simple and objective enzyme-linked immunosorbent assay (ELISA) that measures antibodies to cytochrome P4502D6 (CYP2D6), the target of LKM1. An indirect ELISA using eukaryotically expressed CYP2D6 was designed. Absorbance values obtained against a reference microsomal preparation were subtracted from those obtained against a microsomal preparation over-expressing CYP2D6, thus removing the non-CYP2D6-specific reaction. Sera from 51 LKM1 positive patients (21 autoimmune hepatitis and 30 with HCV infection), 111 LKM1 negative patients with chronic liver disease (including 20 with HCV infection) and 43 healthy controls were tested. Of 51 patients positive by immunofluorescence, 48 were also positive by ELISA while all the 154 LKM1 negative subjects were also negative by ELISA. There was a high degree of association between IFL and ELISA as demonstrated by a kappa reliability value of 0.96. The absorbance values by ELISA correlated with immunofluorescence LKM1 titres both in autoimmune hepatitis (r = 0.74, p < 0.001) and HCV infection (r = 0.67, p < 0.001). The simple, objective ELISA described has the potential to replace the standard immunofluorescence technique.

Using game engine for 3D terrain visualisation of GIS data: A review

NASA Astrophysics Data System (ADS)

Che Mat, Ruzinoor; Shariff, Abdul Rashid Mohammed; Nasir Zulkifli, Abdul; Shafry Mohd Rahim, Mohd; Hafiz Mahayudin, Mohd

2014-06-01

This paper reviews on the 3D terrain visualisation of GIS data using game engines that are available in the market as well as open source. 3D terrain visualisation is a technique used to visualise terrain information from GIS data such as a digital elevation model (DEM), triangular irregular network (TIN) and contour. Much research has been conducted to transform the 2D view of map to 3D. There are several terrain visualisation softwares that are available for free, which include Cesium, Hftool and Landserf. This review paper will help interested users to better understand the current state of art in 3D terrain visualisation of GIS data using game engines.

Graphics Standards in the Computer-Aided Acquisition and Logistic Support (CALS) Program Fiscal Year 1989 Volume 2: MIL-D-28003 Revisions, CGM registration

DTIC Science & Technology

1990-05-01

Naming in CALS U Based on the above rationale and trade studies, including a basic set of trademarked names in the CALS AP should be considered I during a...names for font lists. Based on the various trade studies in this report, including the one on font substitution below the following naming technique...COPYRIGHT SIGN 2/10 -FEMININE ORDINAL INDICATOR I 2/11 LEFT ANGLE QUOTATION MARK 2/12 NOr SIGN 2/13 SOFT HYPHEN 2/14 REGISTERED TRADE MARK SIGN m 2/15

Optimization Techniques for 3D Graphics Deployment on Mobile Devices

NASA Astrophysics Data System (ADS)

Koskela, Timo; Vatjus-Anttila, Jarkko

2015-03-01

3D Internet technologies are becoming essential enablers in many application areas including games, education, collaboration, navigation and social networking. The use of 3D Internet applications with mobile devices provides location-independent access and richer use context, but also performance issues. Therefore, one of the important challenges facing 3D Internet applications is the deployment of 3D graphics on mobile devices. In this article, we present an extensive survey on optimization techniques for 3D graphics deployment on mobile devices and qualitatively analyze the applicability of each technique from the standpoints of visual quality, performance and energy consumption. The analysis focuses on optimization techniques related to data-driven 3D graphics deployment, because it supports off-line use, multi-user interaction, user-created 3D graphics and creation of arbitrary 3D graphics. The outcome of the analysis facilitates the development and deployment of 3D Internet applications on mobile devices and provides guidelines for future research.

Micro/Nano-scale Strain Distribution Measurement from Sampling Moiré Fringes.

PubMed

Wang, Qinghua; Ri, Shien; Tsuda, Hiroshi

2017-05-23

This work describes the measurement procedure and principles of a sampling moiré technique for full-field micro/nano-scale deformation measurements. The developed technique can be performed in two ways: using the reconstructed multiplication moiré method or the spatial phase-shifting sampling moiré method. When the specimen grid pitch is around 2 pixels, 2-pixel sampling moiré fringes are generated to reconstruct a multiplication moiré pattern for a deformation measurement. Both the displacement and strain sensitivities are twice as high as in the traditional scanning moiré method in the same wide field of view. When the specimen grid pitch is around or greater than 3 pixels, multi-pixel sampling moiré fringes are generated, and a spatial phase-shifting technique is combined for a full-field deformation measurement. The strain measurement accuracy is significantly improved, and automatic batch measurement is easily achievable. Both methods can measure the two-dimensional (2D) strain distributions from a single-shot grid image without rotating the specimen or scanning lines, as in traditional moiré techniques. As examples, the 2D displacement and strain distributions, including the shear strains of two carbon fiber-reinforced plastic specimens, were measured in three-point bending tests. The proposed technique is expected to play an important role in the non-destructive quantitative evaluations of mechanical properties, crack occurrences, and residual stresses of a variety of materials.

Digital stereo-holographic microscopy for studying three-dimensional particle dynamics

NASA Astrophysics Data System (ADS)

Byeon, Hyeokjun; Go, Taesik; Lee, Sang Joon

2018-06-01

A digital stereo-holographic microscopy (DsHM) with two viewing angles is proposed to measure 3D information of microscale particles. This approach includes two volumetric recordings and numerical reconstruction, and it involves the combination of separately reconstructed holograms. The 3D positional information of a particle was determined by searching the center of the overlapped reconstructed volume. After confirming the proposed technique using static spherical particles, the 3D information of moving particles suspended in a Hagen-Poiseiulle flow was successfully obtained. Moreover, the 3D information of nonspherical particles, including ellipsoidal particles and red blood cells, were measured using the proposed technique. In addition to 3D positional information, the orientation and shape of the test samples were obtained from the plane images by slicing the overlapped volume perpendicular to the directions of the image recordings. This DsHM technique will be useful in analyzing the 3D dynamic behavior of various nonspherical particles, which cannot be measured by conventional digital holographic microscopy.

Speckle lithography for fabricating Gaussian, quasi-random 2D structures and black silicon structures

PubMed Central

Bingi, Jayachandra; Murukeshan, Vadakke Matham

2015-01-01

Laser speckle pattern is a granular structure formed due to random coherent wavelet interference and generally considered as noise in optical systems including photolithography. Contrary to this, in this paper, we use the speckle pattern to generate predictable and controlled Gaussian random structures and quasi-random structures photo-lithographically. The random structures made using this proposed speckle lithography technique are quantified based on speckle statistics, radial distribution function (RDF) and fast Fourier transform (FFT). The control over the speckle size, density and speckle clustering facilitates the successful fabrication of black silicon with different surface structures. The controllability and tunability of randomness makes this technique a robust method for fabricating predictable 2D Gaussian random structures and black silicon structures. These structures can enhance the light trapping significantly in solar cells and hence enable improved energy harvesting. Further, this technique can enable efficient fabrication of disordered photonic structures and random media based devices. PMID:26679513

Comparing EQ-5D valuation studies: a systematic review and methodological reporting checklist.

PubMed

Xie, Feng; Gaebel, Kathryn; Perampaladas, Kuhan; Doble, Brett; Pullenayegum, Eleanor

2014-01-01

There has been a growing interest around the world in developing country-specific scoring algorithms for the EQ-5D. This study systematically reviews all existing EQ-5D valuation studies to highlight their strengths and limitations, explores heterogeneity in observed utilities using meta-regression, and proposes a methodological checklist for reporting EQ-5D valuation studies. . We searched Medline, EMBASE, the National Health Service Economic Evaluation Database (NHS EED) via Wiley's Cochrane Library, and Wiley's Health Economic Evaluation Database from inception through November 2012, as well as bibliographies of key papers and the EuroQol Plenary Meeting Proceedings from 1991 to 2012 for English-language reports of EQ-5D valuation studies. Two reviewers independently screened the titles and abstracts for relevance. Three reviewers performed data extraction and compared the characteristics and scoring algorithms developed in the included valuation studies. . Of the 31 studies included in the review, 19 used the time trade-off (TTO) technique, 10 used the visual analogue scale (VAS) technique, and 2 used both TTO and VAS. Most studies included respondents from the general population selected by random or quota sampling and used face-to-face interviews or postal surveys. Studies valued between 7 and 198 total states, with 1-23 states valued per respondent. Different model specifications have been proposed for scoring. Some sample or demographic factors, including gender, education, percentage urban population, and national health care expenditure, were associated with differences in observed utilities for moderate or severe health states. . EQ-5D valuation studies conducted to date have varied widely in their design and in the resulting scoring algorithms. Therefore, we propose the Checklist for Reporting Valuation Studies of the EQ-5D (CREATE) for those conducting valuation studies.

Autonomous Aerial Refueling Ground Test Demonstration—A Sensor-in-the-Loop, Non-Tracking Method

PubMed Central

Chen, Chao-I; Koseluk, Robert; Buchanan, Chase; Duerner, Andrew; Jeppesen, Brian; Laux, Hunter

2015-01-01

An essential capability for an unmanned aerial vehicle (UAV) to extend its airborne duration without increasing the size of the aircraft is called the autonomous aerial refueling (AAR). This paper proposes a sensor-in-the-loop, non-tracking method for probe-and-drogue style autonomous aerial refueling tasks by combining sensitivity adjustments of a 3D Flash LIDAR camera with computer vision based image-processing techniques. The method overcomes the inherit ambiguity issues when reconstructing 3D information from traditional 2D images by taking advantage of ready to use 3D point cloud data from the camera, followed by well-established computer vision techniques. These techniques include curve fitting algorithms and outlier removal with the random sample consensus (RANSAC) algorithm to reliably estimate the drogue center in 3D space, as well as to establish the relative position between the probe and the drogue. To demonstrate the feasibility of the proposed method on a real system, a ground navigation robot was designed and fabricated. Results presented in the paper show that using images acquired from a 3D Flash LIDAR camera as real time visual feedback, the ground robot is able to track a moving simulated drogue and continuously narrow the gap between the robot and the target autonomously. PMID:25970254

Assessment of metal artifact reduction methods in pelvic CT

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

Abdoli, Mehrsima; Mehranian, Abolfazl; Ailianou, Angeliki

2016-04-15

Purpose: Metal artifact reduction (MAR) produces images with improved quality potentially leading to confident and reliable clinical diagnosis and therapy planning. In this work, the authors evaluate the performance of five MAR techniques for the assessment of computed tomography images of patients with hip prostheses. Methods: Five MAR algorithms were evaluated using simulation and clinical studies. The algorithms included one-dimensional linear interpolation (LI) of the corrupted projection bins in the sinogram, two-dimensional interpolation (2D), a normalized metal artifact reduction (NMAR) technique, a metal deletion technique, and a maximum a posteriori completion (MAPC) approach. The algorithms were applied to ten simulatedmore » datasets as well as 30 clinical studies of patients with metallic hip implants. Qualitative evaluations were performed by two blinded experienced radiologists who ranked overall artifact severity and pelvic organ recognition for each algorithm by assigning scores from zero to five (zero indicating totally obscured organs with no structures identifiable and five indicating recognition with high confidence). Results: Simulation studies revealed that 2D, NMAR, and MAPC techniques performed almost equally well in all regions. LI falls behind the other approaches in terms of reducing dark streaking artifacts as well as preserving unaffected regions (p < 0.05). Visual assessment of clinical datasets revealed the superiority of NMAR and MAPC in the evaluated pelvic organs and in terms of overall image quality. Conclusions: Overall, all methods, except LI, performed equally well in artifact-free regions. Considering both clinical and simulation studies, 2D, NMAR, and MAPC seem to outperform the other techniques.« less

Quantitative techniques for musculoskeletal MRI at 7 Tesla

PubMed Central

Taylor, Meredith D.; Tarbox, Grayson J.; Palmer, Antony J.; Park, Daniel J.

2016-01-01

Whole-body 7 Tesla MRI scanners have been approved solely for research since they appeared on the market over 10 years ago, but may soon be approved for selected clinical neurological and musculoskeletal applications in both the EU and the United States. There has been considerable research work on musculoskeletal applications at 7 Tesla over the past decade, including techniques for ultra-high resolution morphological imaging, 3D T2 and T2* mapping, ultra-short TE applications, diffusion tensor imaging of cartilage, and several techniques for assessing proteoglycan content in cartilage. Most of this work has been done in the knee or other extremities, due to technical difficulties associated with scanning areas such as the hip and torso at 7 Tesla. In this manuscript, we first provide some technical context for 7 Tesla imaging, including challenges and potential advantages. We then review the major quantitative MRI techniques being applied to musculoskeletal applications on 7 Tesla whole-body systems. PMID:28090448

Retinal imaging and image analysis.

PubMed

Abràmoff, Michael D; Garvin, Mona K; Sonka, Milan

2010-01-01

Many important eye diseases as well as systemic diseases manifest themselves in the retina. While a number of other anatomical structures contribute to the process of vision, this review focuses on retinal imaging and image analysis. Following a brief overview of the most prevalent causes of blindness in the industrialized world that includes age-related macular degeneration, diabetic retinopathy, and glaucoma, the review is devoted to retinal imaging and image analysis methods and their clinical implications. Methods for 2-D fundus imaging and techniques for 3-D optical coherence tomography (OCT) imaging are reviewed. Special attention is given to quantitative techniques for analysis of fundus photographs with a focus on clinically relevant assessment of retinal vasculature, identification of retinal lesions, assessment of optic nerve head (ONH) shape, building retinal atlases, and to automated methods for population screening for retinal diseases. A separate section is devoted to 3-D analysis of OCT images, describing methods for segmentation and analysis of retinal layers, retinal vasculature, and 2-D/3-D detection of symptomatic exudate-associated derangements, as well as to OCT-based analysis of ONH morphology and shape. Throughout the paper, aspects of image acquisition, image analysis, and clinical relevance are treated together considering their mutually interlinked relationships.

Retinal Imaging and Image Analysis

PubMed Central

Abràmoff, Michael D.; Garvin, Mona K.; Sonka, Milan

2011-01-01

Many important eye diseases as well as systemic diseases manifest themselves in the retina. While a number of other anatomical structures contribute to the process of vision, this review focuses on retinal imaging and image analysis. Following a brief overview of the most prevalent causes of blindness in the industrialized world that includes age-related macular degeneration, diabetic retinopathy, and glaucoma, the review is devoted to retinal imaging and image analysis methods and their clinical implications. Methods for 2-D fundus imaging and techniques for 3-D optical coherence tomography (OCT) imaging are reviewed. Special attention is given to quantitative techniques for analysis of fundus photographs with a focus on clinically relevant assessment of retinal vasculature, identification of retinal lesions, assessment of optic nerve head (ONH) shape, building retinal atlases, and to automated methods for population screening for retinal diseases. A separate section is devoted to 3-D analysis of OCT images, describing methods for segmentation and analysis of retinal layers, retinal vasculature, and 2-D/3-D detection of symptomatic exudate-associated derangements, as well as to OCT-based analysis of ONH morphology and shape. Throughout the paper, aspects of image acquisition, image analysis, and clinical relevance are treated together considering their mutually interlinked relationships. PMID:22275207

Adding a dimension to the infrared spectra of interfaces using heterodyne detected 2D sum-frequency generation (HD 2D SFG) spectroscopy

PubMed Central

Xiong, Wei; Laaser, Jennifer E.; Mehlenbacher, Randy D.; Zanni, Martin T.

2011-01-01

In the last ten years, two-dimensional infrared spectroscopy has become an important technique for studying molecular structures and dynamics. We report the implementation of heterodyne detected two-dimensional sum-frequency generation (HD 2D SFG) spectroscopy, which is the analog of 2D infrared (2D IR) spectroscopy, but is selective to noncentrosymmetric systems such as interfaces. We implement the technique using mid-IR pulse shaping, which enables rapid scanning, phase cycling, and automatic phasing. Absorptive spectra are obtained, that have the highest frequency resolution possible, from which we extract the rephasing and nonrephasing signals that are sometimes preferred. Using this technique, we measure the vibrational mode of CO adsorbed on a polycrystalline Pt surface. The 2D spectrum reveals a significant inhomogenous contribution to the spectral line shape, which is quantified by simulations. This observation indicates that the surface conformation and environment of CO molecules is more complicated than the simple “atop” configuration assumed in previous work. Our method can be straightforwardly incorporated into many existing SFG spectrometers. The technique enables one to quantify inhomogeneity, vibrational couplings, spectral diffusion, chemical exchange, and many other properties analogous to 2D IR spectroscopy, but specifically for interfaces. PMID:22143772

Adding a dimension to the infrared spectra of interfaces using heterodyne detected 2D sum-frequency generation (HD 2D SFG) spectroscopy.

PubMed

Xiong, Wei; Laaser, Jennifer E; Mehlenbacher, Randy D; Zanni, Martin T

2011-12-27

In the last ten years, two-dimensional infrared spectroscopy has become an important technique for studying molecular structures and dynamics. We report the implementation of heterodyne detected two-dimensional sum-frequency generation (HD 2D SFG) spectroscopy, which is the analog of 2D infrared (2D IR) spectroscopy, but is selective to noncentrosymmetric systems such as interfaces. We implement the technique using mid-IR pulse shaping, which enables rapid scanning, phase cycling, and automatic phasing. Absorptive spectra are obtained, that have the highest frequency resolution possible, from which we extract the rephasing and nonrephasing signals that are sometimes preferred. Using this technique, we measure the vibrational mode of CO adsorbed on a polycrystalline Pt surface. The 2D spectrum reveals a significant inhomogenous contribution to the spectral line shape, which is quantified by simulations. This observation indicates that the surface conformation and environment of CO molecules is more complicated than the simple "atop" configuration assumed in previous work. Our method can be straightforwardly incorporated into many existing SFG spectrometers. The technique enables one to quantify inhomogeneity, vibrational couplings, spectral diffusion, chemical exchange, and many other properties analogous to 2D IR spectroscopy, but specifically for interfaces.

Modeling target normal sheath acceleration using handoffs between multiple simulations

NASA Astrophysics Data System (ADS)

McMahon, Matthew; Willis, Christopher; Mitchell, Robert; King, Frank; Schumacher, Douglass; Akli, Kramer; Freeman, Richard

2013-10-01

We present a technique to model the target normal sheath acceleration (TNSA) process using full-scale LSP PIC simulations. The technique allows for a realistic laser, full size target and pre-plasma, and sufficient propagation length for the accelerated ions and electrons. A first simulation using a 2D Cartesian grid models the laser-plasma interaction (LPI) self-consistently and includes field ionization. Electrons accelerated by the laser are imported into a second simulation using a 2D cylindrical grid optimized for the initial TNSA process and incorporating an equation of state. Finally, all of the particles are imported to a third simulation optimized for the propagation of the accelerated ions and utilizing a static field solver for initialization. We also show use of 3D LPI simulations. Simulation results are compared to recent ion acceleration experiments using SCARLET laser at The Ohio State University. This work was performed with support from ASOFR under contract # FA9550-12-1-0341, DARPA, and allocations of computing time from the Ohio Supercomputing Center.

Raman Hyperspectral Imaging of Microfossils: Potential Pitfalls

PubMed Central

Olcott Marshall, Alison

2013-01-01

Abstract Initially, Raman spectroscopy was a specialized technique used by vibrational spectroscopists; however, due to rapid advancements in instrumentation and imaging techniques over the last few decades, Raman spectrometers are widely available at many institutions, allowing Raman spectroscopy to become a widespread analytical tool in mineralogy and other geological sciences. Hyperspectral imaging, in particular, has become popular due to the fact that Raman spectroscopy can quickly delineate crystallographic and compositional differences in 2-D and 3-D at the micron scale. Although this rapid growth of applications to the Earth sciences has provided great insight across the geological sciences, the ease of application as the instruments become increasingly automated combined with nonspecialists using this techique has resulted in the propagation of errors and misunderstandings throughout the field. For example, the literature now includes misassigned vibration modes, inappropriate spectral processing techniques, confocal depth of laser penetration incorrectly estimated into opaque crystalline solids, and a misconstrued understanding of the anisotropic nature of sp2 carbons. Key Words: Raman spectroscopy—Raman imaging—Confocal Raman spectroscopy—Disordered sp2 carbons—Hematite—Microfossils. Astrobiology 13, 920–931. PMID:24088070

The HB-2D Polarized Neutron Development Beamline at the High Flux Isotope Reactor

NASA Astrophysics Data System (ADS)

Crow, Lowell; Hamilton, WA; Zhao, JK; Robertson, JL

2016-09-01

The Polarized Neutron Development beamline, recently commissioned at the HB-2D position on the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory, provides a tool for development and testing of polarizers, polarized neutron devices, and prototyping of polarized neutron techniques. With available monochromators including pyrolytic graphite and polarizing enriched Fe-57 (Si), the instrument has operated at 4.25 and 2.6 Å wavelengths, using crystal, supermirror, or He-3 polarizers and analyzers in various configurations. The Neutron Optics and Development Team has used the beamline for testing of He-3 polarizers for use at other HFIR and Spallation Neutron Source (SNS) instruments, as well as a variety of flipper devices. Recently, we have acquired new supermirror polarizers which have improved the instrument performance. The team and collaborators also have continuing demonstration experiments of spin-echo focusing techniques, and plans to conduct polarized diffraction measurements. The beamline is also used to support a growing use of polarization techniques at present and future instruments at SNS and HFIR.

New macrocyclic lactones with acaricidal and nematocidal activities from a genetically engineered strain Streptomyces bingchenggensis BCJ60.

PubMed

Li, Jian-Song; Zhang, Hui; Zhang, Shao-Yong; Wang, Hai-Yan; Zhang, Ji; Chen, An-Liang; Wang, Ji-Dong; Xiang, Wen-Sheng

2017-04-01

Two new macrocyclic lactones, 4,25-diethyl-4,25-demethyl-milbemycin β 3 (1) and 27-formaldehyde-milbemycin β 14 (2), were isolated from a genetically engineered strain Streptomyces bingchenggensis BCJ60. Their structures were determined on the basis of spectroscopic analysis, including 1D and 2D NMR techniques as well as ESI-MS and comparison with data from the literature. The acaricidal and nematocidal capacities of compounds 1 and 2 were evaluated against Tetranychus cinnabarinus and Bursaphelenchus xylophilus, respectively. The results showed that the two new macrocyclic lactones 1 and 2 possessed potent acaricidal and nematocidal activities.

76 FR 52025 - Proposed Collection; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-19

..., including the use of automated collection techniques or other forms of information technology. 1. Title and..., respectively, who have a qualifying child who became disabled before age 22. Annuities are also payable to surviving children on the basis of disability under section 2(d)(1)(iii)(C) if the child's disability began...

A 2D spiral turbo-spin-echo technique.

PubMed

Li, Zhiqiang; Karis, John P; Pipe, James G

2018-03-09

2D turbo-spin-echo (TSE) is widely used in the clinic for neuroimaging. However, the long refocusing radiofrequency pulse train leads to high specific absorption rate (SAR) and alters the contrast compared to conventional spin-echo. The purpose of this work is to develop a robust 2D spiral TSE technique for fast T 2 -weighted imaging with low SAR and improved contrast. A spiral-in/out readout is incorporated into 2D TSE to fully take advantage of the acquisition efficiency of spiral sampling while avoiding potential off-resonance-related artifacts compared to a typical spiral-out readout. A double encoding strategy and a signal demodulation method are proposed to mitigate the artifacts because of the T 2 -decay-induced signal variation. An adapted prescan phase correction as well as a concomitant phase compensation technique are implemented to minimize the phase errors. Phantom data demonstrate the efficacy of the proposed double encoding/signal demodulation, as well as the prescan phase correction and concomitant phase compensation. Volunteer data show that the proposed 2D spiral TSE achieves fast scan speed with high SNR, low SAR, and improved contrast compared to conventional Cartesian TSE. A robust 2D spiral TSE technique is feasible and provides a potential alternative to conventional 2D Cartesian TSE for T 2 -weighted neuroimaging. © 2018 International Society for Magnetic Resonance in Medicine.

Respiratory motion resolved, self-gated 4D-MRI using Rotating Cartesian K-space (ROCK)

PubMed Central

Han, Fei; Zhou, Ziwu; Cao, Minsong; Yang, Yingli; Sheng, Ke; Hu, Peng

2017-01-01

Purpose To propose and validate a respiratory motion resolved, self-gated (SG) 4D-MRI technique to assess patient-specific breathing motion of abdominal organs for radiation treatment planning. Methods The proposed 4D-MRI technique was based on the balanced steady-state free-precession (bSSFP) technique and 3D k-space encoding. A novel ROtating Cartesian K-space (ROCK) reordering method was designed that incorporates repeatedly sampled k-space centerline as the SG motion surrogate and allows for retrospective k-space data binning into different respiratory positions based on the amplitude of the surrogate. The multiple respiratory-resolved 3D k-space data were subsequently reconstructed using a joint parallel imaging and compressed sensing method with spatial and temporal regularization. The proposed 4D-MRI technique was validated using a custom-made dynamic motion phantom and was tested in 6 healthy volunteers, in whom quantitative diaphragm and kidney motion measurements based on 4D-MRI images were compared with those based on 2D-CINE images. Results The 5-minute 4D-MRI scan offers high-quality volumetric images in 1.2×1.2×1.6mm3 and 8 respiratory positions, with good soft-tissue contrast. In phantom experiments with triangular motion waveform, the motion amplitude measurements based on 4D-MRI were 11.89% smaller than the ground truth, whereas a −12.5% difference was expected due to data binning effects. In healthy volunteers, the difference between the measurements based on 4D-MRI and the ones based on 2D-CINE were 6.2±4.5% for the diaphragm, 8.2±4.9% and 8.9±5.1% for the right and left kidney. Conclusion The proposed 4D-MRI technique could provide high resolution, high quality, respiratory motion resolved 4D images with good soft-tissue contrast and are free of the “stitching” artifacts usually seen on 4D-CT and 4D-MRI based on resorting 2D-CINE. It could be used to visualize and quantify abdominal organ motion for MRI-based radiation treatment planning. PMID:28133752

Respiratory motion-resolved, self-gated 4D-MRI using rotating cartesian k-space (ROCK).

PubMed

Han, Fei; Zhou, Ziwu; Cao, Minsong; Yang, Yingli; Sheng, Ke; Hu, Peng

2017-04-01

To propose and validate a respiratory motion resolved, self-gated (SG) 4D-MRI technique to assess patient-specific breathing motion of abdominal organs for radiation treatment planning. The proposed 4D-MRI technique was based on the balanced steady-state free-precession (bSSFP) technique and 3D k-space encoding. A novel rotating cartesian k-space (ROCK) reordering method was designed which incorporates repeatedly sampled k-space centerline as the SG motion surrogate and allows for retrospective k-space data binning into different respiratory positions based on the amplitude of the surrogate. The multiple respiratory-resolved 3D k-space data were subsequently reconstructed using a joint parallel imaging and compressed sensing method with spatial and temporal regularization. The proposed 4D-MRI technique was validated using a custom-made dynamic motion phantom and was tested in six healthy volunteers, in whom quantitative diaphragm and kidney motion measurements based on 4D-MRI images were compared with those based on 2D-CINE images. The 5-minute 4D-MRI scan offers high-quality volumetric images in 1.2 × 1.2 × 1.6 mm 3 and eight respiratory positions, with good soft-tissue contrast. In phantom experiments with triangular motion waveform, the motion amplitude measurements based on 4D-MRI were 11.89% smaller than the ground truth, whereas a -12.5% difference was expected due to data binning effects. In healthy volunteers, the difference between the measurements based on 4D-MRI and the ones based on 2D-CINE were 6.2 ± 4.5% for the diaphragm, 8.2 ± 4.9% and 8.9 ± 5.1% for the right and left kidney. The proposed 4D-MRI technique could provide high-resolution, high-quality, respiratory motion-resolved 4D images with good soft-tissue contrast and are free of the "stitching" artifacts usually seen on 4D-CT and 4D-MRI based on resorting 2D-CINE. It could be used to visualize and quantify abdominal organ motion for MRI-based radiation treatment planning. © 2017 American Association of Physicists in Medicine.

Segmentation of pulmonary nodules in three-dimensional CT images by use of a spiral-scanning technique

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

Wang Jiahui; Engelmann, Roger; Li Qiang

2007-12-15

Accurate segmentation of pulmonary nodules in computed tomography (CT) is an important and difficult task for computer-aided diagnosis of lung cancer. Therefore, the authors developed a novel automated method for accurate segmentation of nodules in three-dimensional (3D) CT. First, a volume of interest (VOI) was determined at the location of a nodule. To simplify nodule segmentation, the 3D VOI was transformed into a two-dimensional (2D) image by use of a key 'spiral-scanning' technique, in which a number of radial lines originating from the center of the VOI spirally scanned the VOI from the 'north pole' to the 'south pole'. Themore » voxels scanned by the radial lines provided a transformed 2D image. Because the surface of a nodule in the 3D image became a curve in the transformed 2D image, the spiral-scanning technique considerably simplified the segmentation method and enabled reliable segmentation results to be obtained. A dynamic programming technique was employed to delineate the 'optimal' outline of a nodule in the 2D image, which corresponded to the surface of the nodule in the 3D image. The optimal outline was then transformed back into 3D image space to provide the surface of the nodule. An overlap between nodule regions provided by computer and by the radiologists was employed as a performance metric for evaluating the segmentation method. The database included two Lung Imaging Database Consortium (LIDC) data sets that contained 23 and 86 CT scans, respectively, with 23 and 73 nodules that were 3 mm or larger in diameter. For the two data sets, six and four radiologists manually delineated the outlines of the nodules as reference standards in a performance evaluation for nodule segmentation. The segmentation method was trained on the first and was tested on the second LIDC data sets. The mean overlap values were 66% and 64% for the nodules in the first and second LIDC data sets, respectively, which represented a higher performance level than those of two existing segmentation methods that were also evaluated by use of the LIDC data sets. The segmentation method provided relatively reliable results for pulmonary nodule segmentation and would be useful for lung cancer quantification, detection, and diagnosis.« less

Target Classification of Canonical Scatterers Using Classical Estimation and Dictionary Based Techniques

DTIC Science & Technology

2012-03-22

shapes tested , when the objective parameter set was confined to a dictionary’s de - fined parameter space. These physical characteristics included...8 2.3 Hypothesis Testing and Detection Theory . . . . . . . . . . . . . . . 8 2.4 3-D SAR Scattering Models...basis pursuit de -noising (BPDN) algorithm is chosen to perform extraction due to inherent efficiency and error tolerance. Multiple shape dictionaries

Fast 2D NMR Spectroscopy for In vivo Monitoring of Bacterial Metabolism in Complex Mixtures.

PubMed

Dass, Rupashree; Grudzia Ż, Katarzyna; Ishikawa, Takao; Nowakowski, Michał; Dȩbowska, Renata; Kazimierczuk, Krzysztof

2017-01-01

The biological toolbox is full of techniques developed originally for analytical chemistry. Among them, spectroscopic experiments are very important source of atomic-level structural information. Nuclear magnetic resonance (NMR) spectroscopy, although very advanced in chemical and biophysical applications, has been used in microbiology only in a limited manner. So far, mostly one-dimensional 1 H experiments have been reported in studies of bacterial metabolism monitored in situ . However, low spectral resolution and limited information on molecular topology limits the usability of these methods. These problems are particularly evident in the case of complex mixtures, where spectral peaks originating from many compounds overlap and make the interpretation of changes in a spectrum difficult or even impossible. Often a suite of two-dimensional (2D) NMR experiments is used to improve resolution and extract structural information from internuclear correlations. However, for dynamically changing sample, like bacterial culture, the time-consuming sampling of so-called indirect time dimensions in 2D experiments is inefficient. Here, we propose the technique known from analytical chemistry and structural biology of proteins, i.e., time-resolved non-uniform sampling. The method allows application of 2D (and multi-D) experiments in the case of quickly varying samples. The indirect dimension here is sparsely sampled resulting in significant reduction of experimental time. Compared to conventional approach based on a series of 1D measurements, this method provides extraordinary resolution and is a real-time approach to process monitoring. In this study, we demonstrate the usability of the method on a sample of Escherichia coli culture affected by ampicillin and on a sample of Propionibacterium acnes , an acne causing bacterium, mixed with a dose of face tonic, which is a complicated, multi-component mixture providing complex NMR spectrum. Through our experiments we determine the exact concentration and time at which the anti-bacterial agents affect the bacterial metabolism. We show, that it is worth to extend the NMR toolbox for microbiology by including techniques of 2D z-TOCSY, for total "fingerprinting" of a sample and 2D 13 C-edited HSQC to monitor changes in concentration of metabolites in selected metabolic pathways.

Can Positron 2D-ACAR Resolve the Electronic Structure of HIGH-Tc Superconductors?

NASA Astrophysics Data System (ADS)

Chan, L. P.; Lynn, K. G.; Harshman, D. R.

We examine the ability of the positron Two-Dimensional Angular Correlation Annihilation Radiation (2D-ACAR) technique to resolve the electronic structures of high-Tc cuprate superconductors. Following a short description of the technique, discussions of the theoretical assumptions, data analysis and experimental considerations, in relation to the high-Tc superconductors, are given. We briefly review recent 2D-ACAR experiments on YBa2Cu3O7-x, Bi2Sr2CaCuO8+δ and La2-xSrxCuO4. The 2D-ACAR technique is useful in resolving the band crossings associated with the layers of the superconductors that are preferentially sampled by the positrons. Together with other Fermi surface measurements (namely angle-resolved photoemission), 2D-ACAR can resolve some of the electronic structures of high-Tc cuprate superconductors. In addition, 2D-ACAR measurements of YBa2Cu3O7-x and Bi2Sr2CaCuO8+δ also reveal an interesting temperature dependence in the fine structures, and a change in the positron lifetime in the former.

Registration of in vivo MR to histology of rodent brains using blockface imaging

NASA Astrophysics Data System (ADS)

Uberti, Mariano; Liu, Yutong; Dou, Huanyu; Mosley, R. Lee; Gendelman, Howard E.; Boska, Michael

2009-02-01

Registration of MRI to histopathological sections can enhance bioimaging validation for use in pathobiologic, diagnostic, and therapeutic evaluations. However, commonly used registration methods fall short of this goal due to tissue shrinkage and tearing after brain extraction and preparation. In attempts to overcome these limitations we developed a software toolbox using 3D blockface imaging as the common space of reference. This toolbox includes a semi-automatic brain extraction technique using constraint level sets (CLS), 3D reconstruction methods for the blockface and MR volume, and a 2D warping technique using thin-plate splines with landmark optimization. Using this toolbox, the rodent brain volume is first extracted from the whole head MRI using CLS. The blockface volume is reconstructed followed by 3D brain MRI registration to the blockface volume to correct the global deformations due to brain extraction and fixation. Finally, registered MRI and histological slices are warped to corresponding blockface images to correct slice specific deformations. The CLS brain extraction technique was validated by comparing manual results showing 94% overlap. The image warping technique was validated by calculating target registration error (TRE). Results showed a registration accuracy of a TRE < 1 pixel. Lastly, the registration method and the software tools developed were used to validate cell migration in murine human immunodeficiency virus type one encephalitis.

3D geometrical assessment of femoral curvature: a reverse engineering technique.

PubMed

Chantarapanich, Nattapon; Sitthiseripratip, Kriskrai; Mahaisavariya, Banchong; Wongcumchang, Marut; Siribodhi, Pongwit

2008-09-01

Investigate the 2D/3D geometry of femoral curvature and femoral length using the advanced technique of computerized tomography combined with reverse engineering techniques. The present study was performed using reverse engineering technique based on CT data of 99 cadaveric femora. The femur was divided into three segments, proximal, mid-shaft, and distal regions by defining 35% and 65% of the femoral total length as a boundary of each region. The intramedullary canal in the mid-shaft region was mainly extracted to determine the set of circular center, which could consequence to approximate the 3D femoral radius of curvature using the 3D least square best fit. The 3D femoral curvature was then projected into A-P and M-L directions to investigate the correlation of 2D/3D femoral curvature as normal radiographic images. It was found that the average 3D Thai femoral curvature was 895.46-mm (SD = 238.06) and the average femoral total length is 421.96-mm (SD = 27.61). In addition, the 2D femoral curvature derived from sagittal radiographic image can be used to determine the 3D femoral curvature with this equation: R3D = RSagittal + 3.67 with r = 0.987. This described technique is a non-destructive method that can effectively assess the internal/ external 3D geometric data of the femur The obtained data is useful to develop a proper design of prosthesis that required inserting into the intramedullary canal. From the present study, it can be concluded that the 2DSagittal femoral curvature derived from standard radiographic image can be represented for the 3D femoral curvature.

Improved classification accuracy in 1- and 2-dimensional NMR metabolomics data using the variance stabilising generalised logarithm transformation

PubMed Central

Parsons, Helen M; Ludwig, Christian; Günther, Ulrich L; Viant, Mark R

2007-01-01

Background Classifying nuclear magnetic resonance (NMR) spectra is a crucial step in many metabolomics experiments. Since several multivariate classification techniques depend upon the variance of the data, it is important to first minimise any contribution from unwanted technical variance arising from sample preparation and analytical measurements, and thereby maximise any contribution from wanted biological variance between different classes. The generalised logarithm (glog) transform was developed to stabilise the variance in DNA microarray datasets, but has rarely been applied to metabolomics data. In particular, it has not been rigorously evaluated against other scaling techniques used in metabolomics, nor tested on all forms of NMR spectra including 1-dimensional (1D) 1H, projections of 2D 1H, 1H J-resolved (pJRES), and intact 2D J-resolved (JRES). Results Here, the effects of the glog transform are compared against two commonly used variance stabilising techniques, autoscaling and Pareto scaling, as well as unscaled data. The four methods are evaluated in terms of the effects on the variance of NMR metabolomics data and on the classification accuracy following multivariate analysis, the latter achieved using principal component analysis followed by linear discriminant analysis. For two of three datasets analysed, classification accuracies were highest following glog transformation: 100% accuracy for discriminating 1D NMR spectra of hypoxic and normoxic invertebrate muscle, and 100% accuracy for discriminating 2D JRES spectra of fish livers sampled from two rivers. For the third dataset, pJRES spectra of urine from two breeds of dog, the glog transform and autoscaling achieved equal highest accuracies. Additionally we extended the glog algorithm to effectively suppress noise, which proved critical for the analysis of 2D JRES spectra. Conclusion We have demonstrated that the glog and extended glog transforms stabilise the technical variance in NMR metabolomics datasets. This significantly improves the discrimination between sample classes and has resulted in higher classification accuracies compared to unscaled, autoscaled or Pareto scaled data. Additionally we have confirmed the broad applicability of the glog approach using three disparate datasets from different biological samples using 1D NMR spectra, 1D projections of 2D JRES spectra, and intact 2D JRES spectra. PMID:17605789

Qualitative Research on Fatigue Associated with Depression: Content Validity of the Fatigue Associated with Depression Questionnaire (FAsD-V2).

PubMed

Matza, Louis S; Murray, Lindsey T; Phillips, Glenn A; Konechnik, Thomas J; Dennehy, Ellen B; Bush, Elizabeth N; Revicki, Dennis A

2015-10-01

Fatigue is one of the most common symptoms of major depressive disorder (MDD). The Fatigue Associated with Depression Questionnaire (FAsD) was developed to assess fatigue and its impact in patients with MDD. The current article presents the qualitative research conducted to develop and examine the content validity of the FAsD and FASD-Version 2 (FAsD-V2). Three phases of qualitative research were conducted with patients recruited from a geographically diverse range of clinics in the US. Phase I included concept elicitation focus groups, followed by cognitive interviews. Phase II employed similar techniques in a more targeted sample. Phase III included cognitive interviews to examine whether minor edits made after Phase II altered comprehensibility of the instrument. Concept elicitation focused on patients' perceptions of fatigue and its impact. Cognitive interviews focused on comprehension, clarity, relevance, and comprehensiveness of the instrument. Data were collected using semi-structured discussion guides. Thematic analyses were conducted and saturation was examined. A total of 98 patients with MDD were included. Patients' statements during concept elicitation in phases I and II supported item development and content. Cognitive interviews supported the relevance of the instrument in the target population, and patients consistently demonstrated a good understanding of the instructions, items, response options, and recall period. Minor changes to instructions for the FAsD-V2 did not affect interpretation of the instrument. This qualitative research supports the content validity of the FAsD and FAsD-V2. These results add to previous quantitative psychometric analysis suggesting the FAsD-V2 is a useful tool for assessing fatigue and its impact in patients with MDD.

High-resolution high-sensitivity elemental imaging by secondary ion mass spectrometry: from traditional 2D and 3D imaging to correlative microscopy

NASA Astrophysics Data System (ADS)

Wirtz, T.; Philipp, P.; Audinot, J.-N.; Dowsett, D.; Eswara, S.

2015-10-01

Secondary ion mass spectrometry (SIMS) constitutes an extremely sensitive technique for imaging surfaces in 2D and 3D. Apart from its excellent sensitivity and high lateral resolution (50 nm on state-of-the-art SIMS instruments), advantages of SIMS include high dynamic range and the ability to differentiate between isotopes. This paper first reviews the underlying principles of SIMS as well as the performance and applications of 2D and 3D SIMS elemental imaging. The prospects for further improving the capabilities of SIMS imaging are discussed. The lateral resolution in SIMS imaging when using the microprobe mode is limited by (i) the ion probe size, which is dependent on the brightness of the primary ion source, the quality of the optics of the primary ion column and the electric fields in the near sample region used to extract secondary ions; (ii) the sensitivity of the analysis as a reasonable secondary ion signal, which must be detected from very tiny voxel sizes and thus from a very limited number of sputtered atoms; and (iii) the physical dimensions of the collision cascade determining the origin of the sputtered ions with respect to the impact site of the incident primary ion probe. One interesting prospect is the use of SIMS-based correlative microscopy. In this approach SIMS is combined with various high-resolution microscopy techniques, so that elemental/chemical information at the highest sensitivity can be obtained with SIMS, while excellent spatial resolution is provided by overlaying the SIMS images with high-resolution images obtained by these microscopy techniques. Examples of this approach are given by presenting in situ combinations of SIMS with transmission electron microscopy (TEM), helium ion microscopy (HIM) and scanning probe microscopy (SPM).

Aberrant Expression of Calretinin, D2-40 and Mesothelin in Mucinous and Non-Mucinous Colorectal Carcinomas and Relation to Clinicopathological Features and Prognosis.

PubMed

Foda, Abd AlRahman Mohammad; El-Hawary, Amira Kamal; Hamed, Hazem

2016-10-01

CRC is a heterogeneous disease in terms of morphology, invasive behavior, metastatic capacity, and clinical outcome. Recently, many so-called mesothelial markers, including calretinin, D2-40, WT1, thrombomodulin, mesothelin, and others, have been certified. The aim of this study was to assess the immunohistochemical expression of calretinin and other mesothelial markers (D2-40 and mesothelin) in colorectal mucinous adenocarcinoma (MA) and non mucinous adenocarcinoma (NMA) specimens and relation to clinicopathological features and prognosis using manual tissue microarray technique. We studied tumor tissue specimens from 150 patients with colorectal MA and NMA who underwent radical surgery from January 2007 to January 2012. High-density manual tissue microarrays were constructed using a modified mechanical pencil tip technique, and paraffin sections were submitted for immunohistochemistry using Calretinin, D2-40 and mesothelin expressions. We found that NMA showed significantly more calretinin and D2-40 expression than MA In contrast, no statistically significant difference between NMA and MA was detected in mesothelin expression. There were no statistically significant relations between any of the clinicopathological or histological parameters and any of the three markers. In a univariate analysis, neither calretinin nor D2-40 expressions showed any significant relations to DFS or OS. However, mesothelin luminal expression was significantly associated with worse DFS. Multivariate Cox regression analysis proved that luminal mesothelin expression was an independent negative prognostic factor in NMA. In conclusion, Calretinin, D2-40 and mesothelin are aberrantly expressed in a proportion of CRC cases with more expression in NMA than MA. Aberrant expression of these mesothelial markers was not associated with clinicopathological or histological features of CRCs. Only mesothelin expression appears to be a strong predictor of adverse prognosis.

Magneto-Structural Correlations in Pseudotetrahedral Forms of the [Co(SPh)4]2- Complex Probed by Magnetometry, MCD Spectroscopy, Advanced EPR Techniques, and ab Initio Electronic Structure Calculations.

PubMed

Suturina, Elizaveta A; Nehrkorn, Joscha; Zadrozny, Joseph M; Liu, Junjie; Atanasov, Mihail; Weyhermüller, Thomas; Maganas, Dimitrios; Hill, Stephen; Schnegg, Alexander; Bill, Eckhard; Long, Jeffrey R; Neese, Frank

2017-03-06

The magnetic properties of pseudotetrahedral Co(II) complexes spawned intense interest after (PPh 4 ) 2 [Co(SPh) 4 ] was shown to be the first mononuclear transition-metal complex displaying slow relaxation of the magnetization in the absence of a direct current magnetic field. However, there are differing reports on its fundamental magnetic spin Hamiltonian (SH) parameters, which arise from inherent experimental challenges in detecting large zero-field splittings. There are also remarkable changes in the SH parameters of [Co(SPh) 4 ] 2- upon structural variations, depending on the counterion and crystallization conditions. In this work, four complementary experimental techniques are utilized to unambiguously determine the SH parameters for two different salts of [Co(SPh) 4 ] 2- : (PPh 4 ) 2 [Co(SPh) 4 ] (1) and (NEt 4 ) 2 [Co(SPh) 4 ] (2). The characterization methods employed include multifield SQUID magnetometry, high-field/high-frequency electron paramagnetic resonance (HF-EPR), variable-field variable-temperature magnetic circular dichroism (VTVH-MCD), and frequency domain Fourier transform THz-EPR (FD-FT THz-EPR). Notably, the paramagnetic Co(II) complex [Co(SPh) 4 ] 2- shows strong axial magnetic anisotropy in 1, with D = -55(1) cm -1 and E/D = 0.00(3), but rhombic anisotropy is seen for 2, with D = +11(1) cm -1 and E/D = 0.18(3). Multireference ab initio CASSCF/NEVPT2 calculations enable interpretation of the remarkable variation of D and its dependence on the electronic structure and geometry.

Temporal and modal characterization of DoD source air toxic emission factors: final report

EPA Science Inventory

This project tested three, real-/near real-time monitoring techniques to develop air toxic emission factors for Department of Defense (DoD) platform sources. These techniques included: resonance enhanced multi photon ionization time of flight mass spectrometry (REMPI-TOFMS) for o...

Technique and Preliminary Analysis of Drug-Induced Sleep Endoscopy With Online Polygraphic Cardiorespiratory Monitoring in Patients With Obstructive Sleep Apnea Syndrome.

PubMed

Gobbi, Riccardo; Baiardi, Simone; Mondini, Susanna; Cerritelli, Luca; Piccin, Ottavio; Scaramuzzino, Giuseppe; Milano, Francesca; Melotti, Maria Rita; Mordini, Francesco; Pirodda, Antonio; Cirignotta, Fabio; Sorrenti, Giovanni

2017-05-01

Drug-induced sleep endoscopy is a diagnostic technique that allows dynamic evaluation of the upper airway during artificial sleep. The lack of a standardized procedure and the difficulties associated with direct visual detection of obstructive events result in poor intraobserver and interobserver reliability, especially when otolaryngology surgeons not experienced in the technique are involved. To describe a drug-induced sleep endoscopy technique implemented with simultaneous polygraphic monitoring of cardiorespiratory parameters (DISE-PG) in patients with a diagnosis of obstructive sleep apnea syndrome and discuss the technique's possible advantages compared with the standard procedure. This prospective cohort study included 50 consecutive patients with obstructive sleep apnea syndrome who underwent DISE-PG from March 1, 2013, to June 30, 2014. A standard protocol was adopted, and all the procedures were carried out in an operation room by an experienced otolaryngology surgeon under the supervision of an anesthesiologist. Endoscopic and polygraphic obstructive respiratory events were analyzed offline in a double-blind setting and randomized order. The feasibility and safety of the DISE-PG technique, as well as its sensitivity in detecting respiratory events compared with that of the standard drug-induced sleep endoscopy procedure. All 50 patients (43 men and 7 women; mean [SD] age, 51.1 [12.1] years) underwent DISE-PG without technical problems or patient difficulties regarding the procedure. As expected, polygraphic scoring was more sensitive than endoscopic scoring in identifying obstructive events (mean [SD] total events, 13.3 [6.8] vs 5.3 [3.6]; mean [SD] difference, 8.8 [5.6]; 95% CI, 7.3 to 10.4; Cohen d, -1.5). This difference was most pronounced in patients with a higher apnea-hypopnea index (AHI) at baseline (mean [SD] difference for AHI >30, 27.1% [31.0%]; 95% CI, -36.2% to 90.4%; Cohen d, 0.2; for AH I >40, 76.0% [35.5%]; 95% CI, 4.6% to 147.4%; Cohen d, 0.5; for AHI >50, 92.2% [37.2%]; 95% CI, 17.3% to 167.1%; Cohen d, 0.6) and a high percentage of hypopneas (≥75% of all obstructive events) at baseline (mean [SD] difference, 20.2% [5.4%]; 95% CI, 9.2% to 31.3%; Cohen d, 1.1). No other anthropomorphic or polygraphic features at baseline were associated with the differences between the DISE-PG and baseline home sleep apnea test. The DISE-PG technique is feasible, safe, and more sensitive at detecting an obstructed breathing pattern than is drug-induced sleep endoscopy alone. The DISE-PG technique could be helpful for accurate comprehension of upper airway obstructive dynamics (ie, degree of obstruction and multilevel pattern) and a nonobstructive breathing pattern (ie, central apneas).

Multi-Mode 3D Kirchhoff Migration of Receiver Functions at Continental Scale With Applications to USArray

NASA Astrophysics Data System (ADS)

Millet, F.; Bodin, T.; Rondenay, S.

2017-12-01

The teleseismic scattered seismic wavefield contains valuable information about heterogeneities and discontinuities inside the Earth. By using fast Receiver Function (RF) migration techniques such as classic Common Conversion Point (CCP) stacks, one can easily interpret structural features down to a few hundred kilometers in the mantle. However, strong simplifying 1D assumptions limit the scope of these methods to structures that are relatively planar and sub-horizontal at local-to-regional scales, such as the Lithosphere-Asthenosphere Boundary and the Mantle Transition Zone discontinuities. Other more robust 2D and 2.5D methods rely on fewer assumptions but require considerable, sometime prohibitive, computation time. Following the ideas of Cheng (2017), we have implemented a simple fully 3D Prestack Kirchhoff RF migration scheme which uses the FM3D fast Eikonal solver to compute travel times and scattering angles. The method accounts for 3D elastic point scattering and includes free surface multiples, resulting in enhanced images of laterally varying dipping structures, such as subducted slabs. The method is tested for subduction structures using 2.5D synthetics generated with Raysum and 3D synthetics generated with specfem3D. Results show that dip angles, depths and lateral variations can be recovered almost perfectly. The approach is ideally suited for applications to dense regional datasets, including those collected across the Cascadia and Alaska subduction zones by USArray.

Sci-Thur PM - Colourful Interactions: Highlights 08: ARC TBI using Single-Step Optimized VMAT Fields

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

Hudson, Alana; Gordon, Deborah; Moore, Roseanne

Purpose: This work outlines a new TBI delivery technique to replace a lateral POP full bolus technique. The new technique is done with VMAT arc delivery, without bolus, treating the patient prone and supine. The benefits of the arc technique include: increased patient experience and safety, better dose conformity, better organ at risk sparing, decreased therapist time and reduction of therapist injuries. Methods: In this work we build on a technique developed by Jahnke et al. We use standard arc fields with gantry speeds corrected for varying distance to the patient followed by a single step VMAT optimization on amore » patient CT to increase dose inhomogeneity and to reduce dose to the lungs (vs. blocks). To compare the arc TBI technique to our full bolus technique, we produced plans on patient CTs for both techniques and evaluated several dosimetric parameters using an ANOVA test. Results and Conclusions: The arc technique is able reduce both the hot areas to the body (D2% reduced from 122.2% to 111.8% p<0.01) and the lungs (mean lung dose reduced from 107.5% to 99.1%, p<0.01), both statistically significant, while maintaining coverage (D98% = 97.8% vs. 94.6%, p=0.313, not statistically significant). We developed a more patient and therapist-friendly TBI treatment technique that utilizes single-step optimized VMAT plans. It was found that this technique was dosimetrically equivalent to our previous lateral technique in terms of coverage and statistically superior in terms of reduced lung dose.« less

Three-dimensional Imaging Methods for Quantitative Analysis of Facial Soft Tissues and Skeletal Morphology in Patients with Orofacial Clefts: A Systematic Review

PubMed Central

Kuijpers, Mette A. R.; Chiu, Yu-Ting; Nada, Rania M.; Carels, Carine E. L.; Fudalej, Piotr S.

2014-01-01

Background Current guidelines for evaluating cleft palate treatments are mostly based on two-dimensional (2D) evaluation, but three-dimensional (3D) imaging methods to assess treatment outcome are steadily rising. Objective To identify 3D imaging methods for quantitative assessment of soft tissue and skeletal morphology in patients with cleft lip and palate. Data sources Literature was searched using PubMed (1948–2012), EMBASE (1980–2012), Scopus (2004–2012), Web of Science (1945–2012), and the Cochrane Library. The last search was performed September 30, 2012. Reference lists were hand searched for potentially eligible studies. There was no language restriction. Study selection We included publications using 3D imaging techniques to assess facial soft tissue or skeletal morphology in patients older than 5 years with a cleft lip with/or without cleft palate. We reviewed studies involving the facial region when at least 10 subjects in the sample size had at least one cleft type. Only primary publications were included. Data extraction Independent extraction of data and quality assessments were performed by two observers. Results Five hundred full text publications were retrieved, 144 met the inclusion criteria, with 63 high quality studies. There were differences in study designs, topics studied, patient characteristics, and success measurements; therefore, only a systematic review could be conducted. Main 3D-techniques that are used in cleft lip and palate patients are CT, CBCT, MRI, stereophotogrammetry, and laser surface scanning. These techniques are mainly used for soft tissue analysis, evaluation of bone grafting, and changes in the craniofacial skeleton. Digital dental casts are used to evaluate treatment and changes over time. Conclusion Available evidence implies that 3D imaging methods can be used for documentation of CLP patients. No data are available yet showing that 3D methods are more informative than conventional 2D methods. Further research is warranted to elucidate it. Systematic review registration International Prospective Register of Systematic Reviews, PROSPERO CRD42012002041 PMID:24710215

Measurement of absolute hadronic branching fractions of D mesons and e+e- -->DD cross sections at Ec.m.=3773 MeV.

PubMed

He, Q; Muramatsu, H; Park, C S; Park, W; Thorndike, E H; Coan, T E; Gao, Y S; Liu, F; Artuso, M; Boulahouache, C; Blusk, S; Butt, J; Dambasuren, E; Dorjkhaidav, O; Li, J; Menaa, N; Mountain, R; Nandakumar, R; Randrianarivony, K; Redjimi, R; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, K; Csorna, S E; Bonvicini, G; Cinabro, D; Dubrovin, M; Briere, R A; Chen, G P; Chen, J; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Adam, N E; Alexander, J P; Berkelman, K; Cassel, D G; Crede, V; Duboscq, J E; Ecklund, K M; Ehrlich, R; Fields, L; Gibbons, L; Gittelman, B; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Hsu, L; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Meyer, T O; Onyisi, P U E; Patterson, J R; Peterson, D; Phillips, E A; Pivarski, J; Riley, D; Ryd, A; Sadoff, A J; Schwarthoff, H; Shi, X; Shepherd, M R; Stroiney, S; Sun, W M; Urner, D; Weaver, K M; Wilksen, T; Weinberger, M; Athar, S B; Avery, P; Breva-Newell, L; Patel, R; Potlia, V; Stoeck, H; Yelton, J; Rubin, P; Cawlfield, C; Eisenstein, B I; Gollin, G D; Karliner, I; Kim, D; Lowrey, N; Naik, P; Sedlack, C; Selen, M; Williams, J; Wiss, J; Edwards, K W; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Gong, D T; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Li, S Z; Poling, R; Scott, A W; Smith, A; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Zweber, P; Ernst, J; Mahmood, A H; Severini, H; Asner, D M; Dytman, S A; Love, W; Mehrabyan, S; Mueller, J A; Savinov, V; Li, Z; Lopez, A; Mendez, H; Ramirez, J; Huang, G S; Miller, D H; Pavlunin, V; Sanghi, B; Shipsey, I P J; Adams, G S; Chasse, M; Cravey, M; Cummings, J P; Danko, I; Napolitano, J

2005-09-16

Using 55.8 pb(-1) of e+e- collisions recorded at the psi(3770) resonance with the CLEO-c detector at CESR, we determine absolute hadronic branching fractions of charged and neutral D mesons using a double tag technique. Among measurements for three D0 and six D+ modes, we obtain reference branching fractions B(D0-->K-pi+)=(3.91+/-0.08+/-0.09)% and B(D+-->K-pi+pi+)=(9.5+/-0.2+/-0.3)%, where the uncertainties are statistical and systematic, respectively. Final state radiation is included in these branching fractions by allowing for additional, unobserved, photons in the final state. Using a determination of the integrated luminosity, we also extract the cross sections sigma(e+e- -->D0D0)=(3.60+/-0.07(+0.07)(-0.05)) nb and sigma(e+e- -->D+D-)=(2.79+/-0.07(+0.10)(-0.04)) nb.

Charged-particle emission tomography

NASA Astrophysics Data System (ADS)

Ding, Yijun

Conventional charged-particle imaging techniques--such as autoradiography-- provide only two-dimensional (2D) images of thin tissue slices. To get volumetric information, images of multiple thin slices are stacked. This process is time consuming and prone to distortions, as registration of 2D images is required. We propose a direct three-dimensional (3D) autoradiography technique, which we call charged-particle emission tomography (CPET). This 3D imaging technique enables imaging of thick sections, thus increasing laboratory throughput and eliminating distortions due to registration. In CPET, molecules or cells of interest are labeled so that they emit charged particles without significant alteration of their biological function. Therefore, by imaging the source of the charged particles, one can gain information about the distribution of the molecules or cells of interest. Two special case of CPET include beta emission tomography (BET) and alpha emission tomography (alphaET), where the charged particles employed are fast electrons and alpha particles, respectively. A crucial component of CPET is the charged-particle detector. Conventional charged-particle detectors are sensitive only to the 2-D positions of the detected particles. We propose a new detector concept, which we call particle-processing detector (PPD). A PPD measures attributes of each detected particle, including location, direction of propagation, and/or the energy deposited in the detector. Reconstruction algorithms for CPET are developed, and reconstruction results from simulated data are presented for both BET and alphaET. The results show that, in addition to position, direction and energy provide valuable information for 3D reconstruction of CPET. Several designs of particle-processing detectors are described. Experimental results for one detector are discussed. With appropriate detector design and careful data analysis, it is possible to measure direction and energy, as well as position of each detected particle. The null functions of CPET with PPDs that measure different combinations of attributes are calculated through singular-value decomposition. In general, the more particle attributes are measured from each detection event, the smaller the null space of CPET is. In other words, the higher dimension the data space is, the more information about an object can be recovered from CPET.

Development and comparison of projection and image space 3D nodule insertion techniques

NASA Astrophysics Data System (ADS)

Robins, Marthony; Solomon, Justin; Sahbaee, Pooyan; Samei, Ehsan

2016-04-01

This study aimed to develop and compare two methods of inserting computerized virtual lesions into CT datasets. 24 physical (synthetic) nodules of three sizes and four morphologies were inserted into an anthropomorphic chest phantom (LUNGMAN, KYOTO KAGAKU). The phantom was scanned (Somatom Definition Flash, Siemens Healthcare) with and without nodules present, and images were reconstructed with filtered back projection and iterative reconstruction (SAFIRE) at 0.6 mm slice thickness using a standard thoracic CT protocol at multiple dose settings. Virtual 3D CAD models based on the physical nodules were virtually inserted (accounting for the system MTF) into the nodule-free CT data using two techniques. These techniques include projection-based and image-based insertion. Nodule volumes were estimated using a commercial segmentation tool (iNtuition, TeraRecon, Inc.). Differences were tested using paired t-tests and R2 goodness of fit between the virtually and physically inserted nodules. Both insertion techniques resulted in nodule volumes very similar to the real nodules (<3% difference) and in most cases the differences were not statistically significant. Also, R2 values were all <0.97 for both insertion techniques. These data imply that these techniques can confidently be used as a means of inserting virtual nodules in CT datasets. These techniques can be instrumental in building hybrid CT datasets composed of patient images with virtually inserted nodules.

Low-temperature hydrogen absorption into V and Nb metals from liquid hydrogen

NASA Astrophysics Data System (ADS)

Takata, H.; Ienaga, K.; Shiga, M.; Islam, Md S.; Inagaki, Y.; Tsujii, H.; Hashizume, K.; Kawae, T.

2018-03-01

We report experimental study on low-temperature hydrogen (H) absorption in vanadium (V) and niobium (Nb) nanocontacts below T = 20 K using a point-contact spectroscopy (PCS) technique. When a small bias voltage is applied between both sides of nanocontacts immersed in liquid H2, the differential conductance (dI/dV) and the second derivative (d2 I/dV 2) are changed from those for pure V and Nb nanocontacts. Further, the spectra approach to those for a high concentrated phase of H with increasing the bias voltage. The results indicate that in-situ investigation of H absorption process from liquid H2 is possible through dI/dV and d2 I/dV 2 measurements using the PCS technique.

New phenyl-ethanediols from the culture broth of Boletus edulis.

PubMed

Yang, Wan-Qiu; Qin, Xiang-Dong; Shao, Hong-Jun; Fang, Li-Zhen; Wang, Fei; Ding, Zhi-Hui; Dong, Ze-Jun; Liu, Ji-Kai

2007-04-01

A new phenyl-ethanediol, (1S)-(4-acetylphenyl)-1, 2-ethanediol (1), and a new natural product, (1S)-(3-ethenylphenyl)-1, 2-ethanediol (2), were isolated from the culture broth of the basidiomycete Boletus edulis together with three related known compounds, 1-(4-ethylphenyl)-1, 2-ethanediol (3), 1-(3-ethylphenyl)-1, 2-ethanediol (4) and 1-(3-formylphenyl)-ethanone (5). Their structures were elucidated by spectroscopic methods including extensive 2D-NMR techniques.

Magnetic properties of tapiolite (FeTa2O6); a quasi two-dimensional (2D) antiferromagnet

NASA Astrophysics Data System (ADS)

Chung, E. M. L.; Lees, M. R.; McIntyre, G. J.; Wilkinson, C.; Balakrishnan, G.; Hague, J. P.; Visser, D.; McK Paul, D.

2004-11-01

The possibilities of two-dimensional (2D) short-range magnetic correlations and frustration effects in the mineral tapiolite are investigated using bulk-property measurements and neutron Laue diffraction. In this study of the magnetic properties of synthetic single-crystals of tapiolite, we find that single crystals of FeTa2O6 order antiferromagnetically at TN = 7.95 ± 0.05 K, with extensive two-dimensional correlations existing up to at least 40 K. Although we find no evidence that FeTa2O6 is magnetically frustrated, hallmarks of two-dimensional magnetism observed in our single-crystal data include: (i) broadening of the susceptibility maximum due to short-range correlations, (ii) a spin-flop transition and (iii) lambda anomalies in the heat capacity and d(χT)/dT. Complementary neutron Laue diffraction measurements reveal 1D magnetic diffuse scattering extending along the c* direction perpendicular to the magnetic planes. This magnetic diffuse scattering, observed for the first time using the neutron Laue technique by VIVALDI, arises directly as a result of 2D short-range spin correlations.

Management of postkeratoplasty astigmatism by paired arcuate incisions with compression sutures.

PubMed

Fares, Usama; Mokashi, Aashish A; Al-Aqaba, Mouhamed Ali; Otri, Ahmad Muneer; Miri, Ammar; Dua, Harminder Singh

2013-04-01

To analyse the efficacy of paired arcuate incisions and compression sutures technique in the management of post penetrating keratoplasty (PK) astigmatism. A paired arcuate incision with compression sutures procedure was used to treat 26 eyes with post-PK astigmatism ranging from 6.00 to 16.50 dioptres (D). The incisions were placed at the 7.0 mm optical zone inside the graft-host junction at a depth of 80% of corneal thickness. A 45° paired arc length was planned for eyes with preoperative astigmatism between 6D and 9D, and a 60° paired arc length was planned for eyes with preoperative astigmatism of >9D. At 3 months, corneal topography and refraction was performed and suture(s) removed if indicated. Net and vector astigmatism changes were calculated to determine the efficacy of the procedure. The indications for PK included keratoconus, Fuch's endothelial dystrophy, pseudophakic bullous keratopathy and corneal scar. There was a statistically significant reduction in the mean magnitude of astigmatism from 9.66 ± 2.90D preoperatively to 4.37 ± 2.53D postoperatively in the whole group. The mean decrease in the astigmatism was 4.37 ± 2.05D (58.4%) and 6.23 ± 3.63D (52.6%) in patients with 6-9D and >9D, respectively. Vector power calculations also showed a significant astigmatism reduction in all groups. The safety and efficacy indices were 1.40 and 0.28, respectively. Manual astigmatic keratotomy is a viable technique with relatively good safety and efficacy outcomes. Based on the results we propose that increasing the arc length to a minimum of 60° for astigmatism of 6-9D, and to 75° for astigmatism >9D, is likely to have a greater beneficial effect.

Nematode cholinergic pharmacology

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

Segerberg, M.A.

1989-01-01

Nematode acetylcholine (ACh) receptors were characterized using both biochemical and electrophysiological techniques, including: (1) receptor binding studies in crude homogenates of the free-living nematode Caenorhabditis elegans and the parasitic nematode Ascaris lumbricoides with the high-affinity probe ({sup 3}H)N-methylscopolamine (({sup 3}H)NMS) which binds to muscarinic receptors in many vertebrate and invertebrate tissues (2) measurement of depolarization and contraction induced by a variety of cholinergic agents, including N-methylscopolamine (NMS), in an innervated dorsal muscle strip preparation of Ascaris; (3) examination of the antagonistic actions of d-tubocurarine (dTC) and NMS at dorsal neuromuscular junction; (4) measurement of input resistance changes in Ascaris commissuralmore » motorneurons induced by ACh, dTC, NMS, pilocarpine and other cholinergic drugs.« less

Evaluation of hydrocephalus patients with 3D-SPACE technique using variant FA mode at 3T.

PubMed

Algin, Oktay

2018-06-01

The major advantages of three-dimensional sampling perfection with application optimized contrasts using different flip-angle evolution (3D-SPACE) technique are its high resistance to artifacts that occurs as a result of radiofrequency or static field, the ability of providing images with sub-millimeter voxel size which allows obtaining reformatted images in any plane due to isotropic three-dimensional data with lower specific absorption rate values. That is crucial during examination of cerebrospinal-fluid containing complex structures, and the acquisition time, which is approximately 5 min for scanning of entire cranium. Recent data revealed that T2-weighted (T2W) 3D-SPACE with variant flip-angle mode (VFAM) imaging allows fast and accurate evaluation of the hydrocephalus patients during both pre- and post-operative period for monitoring the treatment. For a better assessment of these patients; radiologists and neurosurgeons should be aware of the details and implications regarding to the 3D-SPACE technique, and they should follow the updates in this field. There could be a misconception about the difference between T2W-VFAM and routine heavily T2W 3D-SPACE images. T2W 3D-SPACE with VFAM imaging is only a subtype of 3D-SPACE technique. In this review, we described the details of T2W 3D-SPACE with VFAM imaging and comprehensively reviewed its recent applications.

Advanced space power requirements and techniques. Task 1: Mission projections and requirements. Volume 1: Technical report

NASA Technical Reports Server (NTRS)

Wolfe, M. G.

1978-01-01

The objectives of this study were to: (1) develop projections of the NASA, DoD, and civil space power requirements for the 1980-1995 time period; (2) identify specific areas of application and space power subsystem type needs for each prospective user; (3) document the supporting and historical base, including relevant cost related measures of performance; and (4) quantify the benefits of specific technology projection advancements. The initial scope of the study included: (1) construction of likely models for NASA, DoD, and civil space systems; (2) generation of a number of future scenarios; (3) extraction of time phased technology requirements based on the scenarios; and (4) cost/benefit analyses of some of the technologies identified.

Patient and technique survival in continuous ambulatory peritoneal dialysis in a single center of the west of Mexico.

PubMed

Rojas-Campos, Enrique; Alcántar-Medina, Mario; Cortés-Sanabria, Laura; Martínez-Ramírez, Héctor R; Camarena, José L; Chávez, Salvador; Flores, Antonio; Nieves, Juan J; Monteón, Francisco; Gómez-Navarro, Benjamin; Cueto-Manzano, Alfonso M

2007-01-01

In Mexico, CAPD survival has been analyzed in few studies from the center of the country. However, there are concerns that such results may not represent what occurs in other province centers of our country, particularly in our geographical area. To evaluate the patient and technique survival on CAPD of a single center of the west of Mexico, and compare them with other reported series. Retrospective cohort study. Tertiary care, teaching hospital located in Guadalajara, Jalisco. Patients from our CAPD program (1999-2002) were retrospectively studied. Interventions. Clinical and biochemical variables at the start of dialysis and at the end of the follow-up were recorded and considered in the analysis of risk factors. Endpoints were patient (alive, dead or lost to follow-up) and technique status at the end of the study (June 2002). 49 patients were included. Mean patient survival (+/- SE) was 3.32 +/- 0.22 years (CI 95%: 2.9-3.8 years). Patients in the present study were younger (39 +/- 17yrs), had larger body surface area (1.72 +/- 0.22 m2), lower hematocrit (25.4 +/- 5.2%), albumin (2.6 +/- 0.6g/dL), and cholesterol (173 +/- 44 mg/dL), and higher urea (300 +/- 93 mg/dL) and creatinine (14.9 +/- 5.6 mg/ dL) than those in other Mexican series. In univariate analysis, the following variables were associated (p < 0.05) to mortality: pre-dialysis age and creatinine clearance, and serum albumin and cholesterol at the end of follow-up. In multivariate analysis, only pre-dialysis creatinine clearance (RR 0.66, p = 0.03) and age (RR 1.08, p = 0.005) significantly predicted mortality. Mean technique survival was 2.83 +/- 0.24 years (CI 95%: 2.4-3.3). Pre-dialysis age (p < 0.05), peritonitis rate (p < 0.05), and serum phosphorus at the end of follow-up (p < 0.05) were associated with technique failure in univariate analysis, while in multivariate analysis, only pre-dialysis age (RR 1.07, p = 0.001) and peritonitis rate (RR 481, p < 0.0001) were technique failure predictors. Patients from this single center of the west of Mexico were younger, had higher body surface area and initiated peritoneal dialysis with a more deteriorated general status than patients reported in other Mexican series; in spite of the latter, patient and technique survival were not different. In our setting, pre-dialysis older age and lower CrCl significantly predicted mortality, while older predialysis age and higher peritonitis rate predicted technique failure.

4D flow imaging with MRI

PubMed Central

Stankovic, Zoran; Allen, Bradley D.; Garcia, Julio; Jarvis, Kelly B.

2014-01-01

Magnetic resonance imaging (MRI) has become an important tool for the clinical evaluation of patients with cardiovascular disease. Since its introduction in the late 1980s, 2-dimensional phase contrast MRI (2D PC-MRI) has become a routine part of standard-of-care cardiac MRI for the assessment of regional blood flow in the heart and great vessels. More recently, time-resolved PC-MRI with velocity encoding along all three flow directions and three-dimensional (3D) anatomic coverage (also termed ‘4D flow MRI’) has been developed and applied for the evaluation of cardiovascular hemodynamics in multiple regions of the human body. 4D flow MRI allows for the comprehensive evaluation of complex blood flow patterns by 3D blood flow visualization and flexible retrospective quantification of flow parameters. Recent technical developments, including the utilization of advanced parallel imaging techniques such as k-t GRAPPA, have resulted in reasonable overall scan times, e.g., 8-12 minutes for 4D flow MRI of the aorta and 10-20 minutes for whole heart coverage. As a result, the application of 4D flow MRI in a clinical setting has become more feasible, as documented by an increased number of recent reports on the utility of the technique for the assessment of cardiac and vascular hemodynamics in patient studies. A number of studies have demonstrated the potential of 4D flow MRI to provide an improved assessment of hemodynamics which might aid in the diagnosis and therapeutic management of cardiovascular diseases. The purpose of this review is to describe the methods used for 4D flow MRI acquisition, post-processing and data analysis. In addition, the article provides an overview of the clinical applications of 4D flow MRI and includes a review of applications in the heart, thoracic aorta and hepatic system. PMID:24834414

Charged-particle emission tomography

PubMed Central

Ding, Yijun; Caucci, Luca; Barrett, Harrison H.

2018-01-01

Purpose Conventional charged-particle imaging techniques —such as autoradiography —provide only two-dimensional (2D) black ex vivo images of thin tissue slices. In order to get volumetric information, images of multiple thin slices are stacked. This process is time consuming and prone to distortions, as registration of 2D images is required. We propose a direct three-dimensional (3D) autoradiography technique, which we call charged-particle emission tomography (CPET). This 3D imaging technique enables imaging of thick tissue sections, thus increasing laboratory throughput and eliminating distortions due to registration. CPET also has the potential to enable in vivo charged-particle imaging with a window chamber or an endoscope. Methods Our approach to charged-particle emission tomography uses particle-processing detectors (PPDs) to estimate attributes of each detected particle. The attributes we estimate include location, direction of propagation, and/or the energy deposited in the detector. Estimated attributes are then fed into a reconstruction algorithm to reconstruct the 3D distribution of charged-particle-emitting radionuclides. Several setups to realize PPDs are designed. Reconstruction algorithms for CPET are developed. Results Reconstruction results from simulated data showed that a PPD enables CPET if the PPD measures more attributes than just the position from each detected particle. Experiments showed that a two-foil charged-particle detector is able to measure the position and direction of incident alpha particles. Conclusions We proposed a new volumetric imaging technique for charged-particle-emitting radionuclides, which we have called charged-particle emission tomography (CPET). We also proposed a new class of charged-particle detectors, which we have called particle-processing detectors (PPDs). When a PPD is used to measure the direction and/or energy attributes along with the position attributes, CPET is feasible. PMID:28370094

Charged-particle emission tomography.

PubMed

Ding, Yijun; Caucci, Luca; Barrett, Harrison H

2017-06-01

Conventional charged-particle imaging techniques - such as autoradiography - provide only two-dimensional (2D) black ex vivo images of thin tissue slices. In order to get volumetric information, images of multiple thin slices are stacked. This process is time consuming and prone to distortions, as registration of 2D images is required. We propose a direct three-dimensional (3D) autoradiography technique, which we call charged-particle emission tomography (CPET). This 3D imaging technique enables imaging of thick tissue sections, thus increasing laboratory throughput and eliminating distortions due to registration. CPET also has the potential to enable in vivo charged-particle imaging with a window chamber or an endoscope. Our approach to charged-particle emission tomography uses particle-processing detectors (PPDs) to estimate attributes of each detected particle. The attributes we estimate include location, direction of propagation, and/or the energy deposited in the detector. Estimated attributes are then fed into a reconstruction algorithm to reconstruct the 3D distribution of charged-particle-emitting radionuclides. Several setups to realize PPDs are designed. Reconstruction algorithms for CPET are developed. Reconstruction results from simulated data showed that a PPD enables CPET if the PPD measures more attributes than just the position from each detected particle. Experiments showed that a two-foil charged-particle detector is able to measure the position and direction of incident alpha particles. We proposed a new volumetric imaging technique for charged-particle-emitting radionuclides, which we have called charged-particle emission tomography (CPET). We also proposed a new class of charged-particle detectors, which we have called particle-processing detectors (PPDs). When a PPD is used to measure the direction and/or energy attributes along with the position attributes, CPET is feasible. © 2017 The Authors. Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

Seeing the tipping point: Balance perception and visual shape.

PubMed

Firestone, Chaz; Keil, Frank C

2016-07-01

In a brief glance at an object or shape, we can appreciate a rich suite of its functional properties, including the organization of the object's parts, its optimal contact points for grasping, and its center of mass, or balancing point. However, in the real world and the laboratory, balance perception shows systematic biases whereby observers may misjudge a shape's center of mass by a severe margin. Are such biases simply quirks of physical reasoning? Or might they instead reflect more fundamental principles of object representation? Here we demonstrate systematically biased center-of-mass estimation for two-dimensional (2D) shapes (Study 1) and advance a surprising explanation of such biases. We suggest that the mind implicitly represents ordinary 2D shapes as rich, volumetric, three-dimensional (3D) objects, and that these "inflated" shape representations intrude on and bias perception of the 2D shape's geometric properties. Such "inflation" is a computer-graphics technique for segmenting shapes into parts, and we show that a model derived from this technique best accounts for the biases in center-of-mass estimation in Study 1. Further supporting this account, we show that reducing the need for inflated shape representations diminishes such biases: Center-of-mass estimation improved when cues to shapehood were attenuated (Study 2) and when shapes' depths were explicitly depicted using real-life objects laser-cut from wood (Study 3). We suggest that the technique of shape inflation is actually implemented in the mind; thus, biases in our impressions of balance reflect a more general functional characteristic of object perception. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

A low-cost microwell device for high-resolution imaging of neurite outgrowth in 3D

NASA Astrophysics Data System (ADS)

Ren, Yuan; Mlodzianoski, Michael J.; Cheun Lee, Aih; Huang, Fang; Suter, Daniel M.

2018-06-01

Objective. Current neuronal cell culture is mostly performed on two-dimensional (2D) surfaces, which lack many of the important features of the native environment of neurons, including topographical cues, deformable extracellular matrix, and spatial isotropy or anisotropy in three dimensions. Although three-dimensional (3D) cell culture systems provide a more physiologically relevant environment than 2D systems, their popularity is greatly hampered by the lack of easy-to-make-and-use devices. We aim to develop a widely applicable 3D culture procedure to facilitate the transition of neuronal cultures from 2D to 3D. Approach. We made a simple microwell device for 3D neuronal cell culture that is inexpensive, easy to assemble, and fully compatible with commonly used imaging techniques, including super-resolution microscopy. Main results. We developed a novel gel mixture to support 3D neurite regeneration of Aplysia bag cell neurons, a system that has been extensively used for quantitative analysis of growth cone dynamics in 2D. We found that the morphology and growth pattern of bag cell growth cones in 3D culture closely resemble the ones of growth cones observed in vivo. We demonstrated the capability of our device for high-resolution imaging of cytoskeletal and signaling proteins as well as organelles. Significance. Neuronal cell culture has been a valuable tool for neuroscientists to study the behavior of neurons in a controlled environment. Compared to 2D, neurons cultured in 3D retain the majority of their native characteristics, while offering higher accessibility, control, and repeatability. We expect that our microwell device will facilitate a wider adoption of 3D neuronal cultures to study the mechanisms of neurite regeneration.

Optimizing transformations of stencil operations for parallel cache-based architectures

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

Bassetti, F.; Davis, K.

This paper describes a new technique for optimizing serial and parallel stencil- and stencil-like operations for cache-based architectures. This technique takes advantage of the semantic knowledge implicity in stencil-like computations. The technique is implemented as a source-to-source program transformation; because of its specificity it could not be expected of a conventional compiler. Empirical results demonstrate a uniform factor of two speedup. The experiments clearly show the benefits of this technique to be a consequence, as intended, of the reduction in cache misses. The test codes are based on a 5-point stencil obtained by the discretization of the Poisson equation andmore » applied to a two-dimensional uniform grid using the Jacobi method as an iterative solver. Results are presented for a 1-D tiling for a single processor, and in parallel using 1-D data partition. For the parallel case both blocking and non-blocking communication are tested. The same scheme of experiments has bee n performed for the 2-D tiling case. However, for the parallel case the 2-D partitioning is not discussed here, so the parallel case handled for 2-D is 2-D tiling with 1-D data partitioning.« less

Higher-dimensional phase imaging

NASA Astrophysics Data System (ADS)

Huntley, Jonathan M.

2010-04-01

Traditional full-field interferometric techniques (speckle, moiré, holography etc) provide 2-D phase images, which encode the surface deformation state of the object under test. Over the past 15 years, the use of additional spatial or temporal dimensions has been investigated by a number of research groups. Early examples include the measurement of 3-D surface profiles by temporally-varying projected fringe patterns, and dynamic speckle interferometry. More recently (the past 5 years) a family of related techniques (Wavelength Scanning Interferometry, Phase Contrast Spectral Optical Coherence Tomography (OCT), and Tilt Scanning Interferometry) has emerged that provides the volume deformation state of the object. The techniques can be thought of as a marriage between the phase sensing capabilities of Phase Shifting Interferometry and the depth-sensing capabilities of OCT. Finally, in the past 12 months a technique called Hyperspectral Interferometry has been proposed in which absolute optical path distributions are obtained in a single shot through the spectral decomposition of a white light interferogram, and for which the additional dimension therefore corresponds to the illumination wavenumber. An overview of these developments, and the related issue of robust phase unwrapping of noisy 3-D wrapped phase volumes, is presented in this paper.

Comparison of two-dimensional fast spin echo T2 weighted sequences and three-dimensional volume isotropic T2 weighted fast spin echo (VISTA) MRI in the evaluation of triangular fibrocartilage of the wrist.

PubMed

Park, Hee Jin; Lee, So Yeon; Kang, Kyung A; Kim, Eun Young; Shin, Hun Kyu; Park, Se Jin; Park, Jai Hyung; Kim, Eugene

2018-04-01

To compare image quality of three-dimensional volume isotropic T 2 weighted fast spin echo (3D VISTA) and two-dimensional (2D) T 2 weighted images (T2WI) for evaluation of triangular fibrocartilage (TFC) and to investigate whether 3D VISTA can replace 2D T 2 WI in evaluating TFC injury. This retrospective study included 69 patients who received wrist MRIs using both 2D T 2 WI and 3D VISTA techniques for assessment of wrist pathology, including TFC injury. Two radiologists measured the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) of the two sequences. The anatomical identification score and diagnostic performance were independently assessed by two interpreters. The diagnostic abilities of 3D VISTA and 2D T 2 WI were analysed by sensitivity, specificity and accuracy for diagnosing TFC injury using surgically or clinically confirmed diagnostic reference standards. 17 cases (25%) were classified as having TFC injury. 2 cases (12%) were diagnosed surgically, and 15 cases (88%) were diagnosed by physical examination. 52 cases (75%) were diagnosed as having intact TFC. 8 of these cases (15%) were surgically confirmed, while the others were diagnosed by physical examination and clinical findings. The 3D VISTA images had significantly higher SNR and CNR values for the TFC than 2D T 2 WI images. The scores of 3D VISTA's total length, full width and sharpness were similar to those of 2D T 2 WI. We were unable to find a significant difference between 3D VISTA and 2D T 2 WI in the ability to diagnose TFC injury. 3D VISTA image quality is similar to that of 2D T 2 WI for TFC evaluation and is also excellent for tissue contrast. 3D VISTA can replace 2D images in TFC injury assessment. Advances in knowledge: 3D VISTA image quality is similar to that of 2D T 2 WI for TFC evaluation and is also excellent for tissue contrast. 3D VISTA can replace 2D images in TFC injury assessment.

Functionalized graphene and other two-dimensional materials for photovoltaic devices: device design and processing.

PubMed

Liu, Zhike; Lau, Shu Ping; Yan, Feng

2015-08-07

Graphene is the thinnest two-dimensional (2D) carbon material and has many advantages including high carrier mobilities and conductivity, high optical transparency, excellent mechanical flexibility and chemical stability, which make graphene an ideal material for various optoelectronic devices. The major applications of graphene in photovoltaic devices are for transparent electrodes and charge transport layers. Several other 2D materials have also shown advantages in charge transport and light absorption over traditional semiconductor materials used in photovoltaic devices. Great achievements in the applications of 2D materials in photovoltaic devices have been reported, yet numerous challenges still remain. For practical applications, the device performance should be further improved by optimizing the 2D material synthesis, film transfer, surface functionalization and chemical/physical doping processes. In this review, we will focus on the recent advances in the applications of graphene and other 2D materials in various photovoltaic devices, including organic solar cells, Schottky junction solar cells, dye-sensitized solar cells, quantum dot-sensitized solar cells, other inorganic solar cells, and perovskite solar cells, in terms of the functionalization techniques of the materials, the device design and the device performance. Finally, conclusions and an outlook for the future development of this field will be addressed.

3D polymer gel dosimetry using a 3D (DESS) and a 2D MultiEcho SE (MESE) sequence

NASA Astrophysics Data System (ADS)

Maris, Thomas G.; Pappas, Evangelos; Karolemeas, Kostantinos; Papadakis, Antonios E.; Zacharopoulou, Fotini; Papanikolaou, Nickolas; Gourtsoyiannis, Nicholas

2006-12-01

The utilization of 3D techniques in Magnetic Resonance Imaging data aquisition and post-processing analysis is a prerequisite especially when modern radiotherapy techniques (conformal RT, IMRT, Stereotactic RT) are to be used. The aim of this work is to compare a 3D Double Echo Steady State (DESS) and a 2D Multiple Echo Spin Echo (MESE) sequence in 3D MRI radiation dosimetry using two different MRI scanners and utilising N-VInylPyrrolidone (VIPAR) based polymer gels.

3D reconstruction of a carotid bifurcation from 2D transversal ultrasound images.

PubMed

Yeom, Eunseop; Nam, Kweon-Ho; Jin, Changzhu; Paeng, Dong-Guk; Lee, Sang-Joon

2014-12-01

Visualizing and analyzing the morphological structure of carotid bifurcations are important for understanding the etiology of carotid atherosclerosis, which is a major cause of stroke and transient ischemic attack. For delineation of vasculatures in the carotid artery, ultrasound examinations have been widely employed because of a noninvasive procedure without ionizing radiation. However, conventional 2D ultrasound imaging has technical limitations in observing the complicated 3D shapes and asymmetric vasodilation of bifurcations. This study aims to propose image-processing techniques for better 3D reconstruction of a carotid bifurcation in a rat by using 2D cross-sectional ultrasound images. A high-resolution ultrasound imaging system with a probe centered at 40MHz was employed to obtain 2D transversal images. The lumen boundaries in each transverse ultrasound image were detected by using three different techniques; an ellipse-fitting, a correlation mapping to visualize the decorrelation of blood flow, and the ellipse-fitting on the correlation map. When the results are compared, the third technique provides relatively good boundary extraction. The incomplete boundaries of arterial lumen caused by acoustic artifacts are somewhat resolved by adopting the correlation mapping and the distortion in the boundary detection near the bifurcation apex was largely reduced by using the ellipse-fitting technique. The 3D lumen geometry of a carotid artery was obtained by volumetric rendering of several 2D slices. For the 3D vasodilatation of the carotid bifurcation, lumen geometries at the contraction and expansion states were simultaneously depicted at various view angles. The present 3D reconstruction methods would be useful for efficient extraction and construction of the 3D lumen geometries of carotid bifurcations from 2D ultrasound images. Copyright © 2014 Elsevier B.V. All rights reserved.

Chromomycin SA analogs from a marine-derived Streptomyces sp.

PubMed Central

Hu, Youcai; Espindola, Ana Paula D. M; Stewart, Nathan A.; Wei, Shuguang; Posner, Bruce A.; MacMillan, John B.

2011-01-01

Two chromomycin SA analogs, chromomycin SA3 and chromomycin SA2, along with deacetylchromomycin A3 and five previously reported chromomycin analogs were isolated from a marine-derived Streptomyces sp. The structures of the new compounds were determined by spectroscopic methods including 1D and 2D NMR techniques, HRMS and chemical methods. Chromomycin SA3 and chromomycin SA2 are the first naturally occuring chromomycin analogs with truncated side-chains. Biological evaluation of chromomycin analogs for cytotoxicity against two non-small cell lung cancer (NSCLC) cell-lines, A549 and HCC44, demonstrated a decrease in cytotoxicity for the truncated sides chain chromomycin analogs. PMID:21807523

Pahangensin A and B, two new antibacterial diterpenes from the rhizomes of Alpinia pahangensis Ridley.

PubMed

Sivasothy, Yasodha; Ibrahim, Halijah; Paliany, Audra Shaleena; Alias, Siti Aisyah; Awang, Khalijah

2013-12-01

The rhizomes of Alpinia pahangensis Ridley yielded a new bis-labdanic diterpene for which the name pahangensin A (1) was proposed along with a new labdane diterpene, pahangensin B (2). Their structures were elucidated by spectroscopic methods including, 1D and 2D NMR techniques and LCMS-IT-TOF analysis. Pahangensin A (1) was found to be an antibacterial agent against Staphylococcus aureus, Bacillus cereus and Bacillus subtilis with MIC values less than 100 μg/mL, respectively. Pahangensin B (2) exhibited antibacterial activity (MIC <100 μg/mL) against B. cereus. Copyright © 2013 Elsevier Ltd. All rights reserved.

Microwave spectroscopy of high-L Rydberg states of nickel

NASA Astrophysics Data System (ADS)

Lindsay, Mark D.; Keele, Julie A.; Woods, Shannon L.; Lundeen, Stephen R.

2010-03-01

High-L non-penetrating Rydberg levels of nickel display a fine structure pattern consisting of six levels for each value of L. This pattern was studied recently with the optical RESIS technique, determining initial values of the quadrupole moment and polarizabilities of the ^2D5/2 ground state of Ni^+ [1]. Measurements are now in progress using the microwave RESIS technique [2], which promises much more precise measurements of the fine structure and of the related core properties, including the permanent hexadecapole moment.[4pt] [1] Julie A. Keele, et. al., to be published, Phys. Rev. A[0pt] [2] M.E. Hanni, et. al., Phys. Rev. A 78, 062510 (2008)

Sci-Thur AM: YIS – 03: Combining sagittally-reconstructed 3D and live-2D ultrasound for high-dose-rate prostate brachytherapy needle segmentation

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

Hrinivich, Thomas; Hoover, Douglas; Surry, Kathlee

Ultrasound-guided high-dose-rate prostate brachytherapy (HDR-BT) needle segmentation is performed clinically using live-2D sagittal images. Organ segmentation is then performed using axial images, introducing a source of geometric uncertainty. Sagittally-reconstructed 3D (SR3D) ultrasound enables both needle and organ segmentation, but suffers from shadow artifacts. We present a needle segmentation technique augmenting SR3D with live-2D sagittal images using mechanical probe tracking to mitigate image artifacts and compare it to the clinical standard. Seven prostate cancer patients underwent TRUS-guided HDR-BT during which the clinical and proposed segmentation techniques were completed in parallel using dual ultrasound video outputs. Calibrated needle end-length measurements were usedmore » to calculate insertion depth errors (IDEs), and the dosimetric impact of IDEs was evaluated by perturbing clinical treatment plan source positions. The proposed technique provided smaller IDEs than the clinical approach, with mean±SD of −0.3±2.2 mm and −0.5±3.7mm respectively. The proposed and clinical techniques resulted in 84% and 43% of needles with IDEs within ±3mm, and IDE ranges across all needles of [−7.7mm, 5.9mm] and [−9.3mm, 7.7mm] respectively. The proposed and clinical IDEs lead to mean±SD changes in the volume of the prostate receiving the prescription dose of −0.6±0.9% and −2.0±5.3% respectively. The proposed technique provides improved HDR-BT needle segmentation accuracy over the clinical technique leading to decreased dosimetric uncertainty by eliminating the axial-to-sagittal registration, and mitigates the effect of shadow artifacts by incorporating mechanically registered live-2D sagittal images.« less

Summary on several key techniques in 3D geological modeling.

PubMed

Mei, Gang

2014-01-01

Several key techniques in 3D geological modeling including planar mesh generation, spatial interpolation, and surface intersection are summarized in this paper. Note that these techniques are generic and widely used in various applications but play a key role in 3D geological modeling. There are two essential procedures in 3D geological modeling: the first is the simulation of geological interfaces using geometric surfaces and the second is the building of geological objects by means of various geometric computations such as the intersection of surfaces. Discrete geometric surfaces that represent geological interfaces can be generated by creating planar meshes first and then spatially interpolating; those surfaces intersect and then form volumes that represent three-dimensional geological objects such as rock bodies. In this paper, the most commonly used algorithms of the key techniques in 3D geological modeling are summarized.

PMMA-Etching-Free Transfer of Wafer-scale Chemical Vapor Deposition Two-dimensional Atomic Crystal by a Water Soluble Polyvinyl Alcohol Polymer Method

PubMed Central

Van Ngoc, Huynh; Qian, Yongteng; Han, Suk Kil; Kang, Dae Joon

2016-01-01

We have explored a facile technique to transfer large area 2-Dimensional (2D) materials grown by chemical vapor deposition method onto various substrates by adding a water-soluble Polyvinyl Alcohol (PVA) layer between the polymethyl-methacrylate (PMMA) and the 2D material film. This technique not only allows the effective transfer to an arbitrary target substrate with a high degree of freedom, but also avoids PMMA etching thereby maintaining the high quality of the transferred 2D materials with minimum contamination. We applied this method to transfer various 2D materials grown on different rigid substrates of general interest, such as graphene on copper foil, h-BN on platinum and MoS2 on SiO2/Si. This facile transfer technique has great potential for future research towards the application of 2D materials in high performance optical, mechanical and electronic devices. PMID:27616038

A software tool for automatic classification and segmentation of 2D/3D medical images

NASA Astrophysics Data System (ADS)

Strzelecki, Michal; Szczypinski, Piotr; Materka, Andrzej; Klepaczko, Artur

2013-02-01

Modern medical diagnosis utilizes techniques of visualization of human internal organs (CT, MRI) or of its metabolism (PET). However, evaluation of acquired images made by human experts is usually subjective and qualitative only. Quantitative analysis of MR data, including tissue classification and segmentation, is necessary to perform e.g. attenuation compensation, motion detection, and correction of partial volume effect in PET images, acquired with PET/MR scanners. This article presents briefly a MaZda software package, which supports 2D and 3D medical image analysis aiming at quantification of image texture. MaZda implements procedures for evaluation, selection and extraction of highly discriminative texture attributes combined with various classification, visualization and segmentation tools. Examples of MaZda application in medical studies are also provided.

Improved Underwater Excitation-Emission Matrix Fluorometer

NASA Technical Reports Server (NTRS)

Moore, Casey; daCunha, John; Rhoades, Bruce; Twardowski, Michael

2007-01-01

A compact, high-resolution, two-dimensional excitation-emission matrix fluorometer (EEMF) has been designed and built specifically for use in identifying and measuring the concentrations of organic compounds, including polluting hydrocarbons, in natural underwater settings. Heretofore, most EEMFs have been designed and built for installation in laboratories, where they are used to analyze the contents of samples collected in the field and brought to the laboratories. Because the present EEMF can be operated in the field, it is better suited to measurement of spatially and temporally varying concentrations of substances of interest. In excitation-emission matrix (EEM) fluorometry, fluorescence is excited by irradiating a sample at one or more wavelengths, and the fluorescent emission from the sample is measured at multiple wavelengths. When excitation is provided at only one wavelength, the technique is termed one-dimensional (1D) EEM fluorometry because the resulting matrix of fluorescence emission data (the EEM) contains only one row or column. When excitation is provided at multiple wavelengths, the technique is termed two-dimensional (2D) EEM fluorometry because the resulting EEM contains multiple rows and columns. EEM fluorometry - especially the 2D variety - is well established as a means of simultaneously detecting numerous dissolved and particulate compounds in water. Each compound or pool of compounds has a unique spectral fluorescence signature, and each EEM is rich in information content, in that it can contain multiple fluorescence signatures. By use of deconvolution and/or other mixture-analyses techniques, it is often possible to isolate the spectral signature of compounds of interest, even when their fluorescence spectra overlap. What distinguishes the present 2D EEMF over prior laboratory-type 2D EEMFs are several improvements in packaging (including a sealed housing) and other aspects of design that render it suitable for use in natural underwater settings. In addition, the design of the present 2D EEMF incorporates improvements over the one prior commercial underwater 2D EEMF, developed in 1994 by the same company that developed the present one. Notable advanced features of the present EEMF include the following: 1) High sensitivity and spectral resolution are achieved by use of an off-the-shelf grating spectrometer equipped with a sensor in the form of a commercial astronomical- grade 256 532-pixel charge-coupled-device (CCD) array. 2) All of the power supply, timing, control, and readout circuits for the illumination source and the CCD, ancillary environmental monitoring sensors, and circuitry for controlling a shutter or filter motor are custom-designed and mounted compactly on three circuit boards below a fourth circuit board that holds the CCD (see figure). 3) The compactness of the grating spectrometer, CCD, and circuit assembly makes it possible to fit the entire instrument into a compact package that is intended to be maneuverable underwater by one person. 4) In mass production, the cost of the complete instrument would be relatively low - estimated at approximately $30,000 at 2005 prices.

Using x-ray mammograms to assist in microwave breast image interpretation.

PubMed

Curtis, Charlotte; Frayne, Richard; Fear, Elise

2012-01-01

Current clinical breast imaging modalities include ultrasound, magnetic resonance (MR) imaging, and the ubiquitous X-ray mammography. Microwave imaging, which takes advantage of differing electromagnetic properties to obtain image contrast, shows potential as a complementary imaging technique. As an emerging modality, interpretation of 3D microwave images poses a significant challenge. MR images are often used to assist in this task, and X-ray mammograms are readily available. However, X-ray mammograms provide 2D images of a breast under compression, resulting in significant geometric distortion. This paper presents a method to estimate the 3D shape of the breast and locations of regions of interest from standard clinical mammograms. The technique was developed using MR images as the reference 3D shape with the future intention of using microwave images. Twelve breast shapes were estimated and compared to ground truth MR images, resulting in a skin surface estimation accurate to within an average Euclidean distance of 10 mm. The 3D locations of regions of interest were estimated to be within the same clinical area of the breast as corresponding regions seen on MR imaging. These results encourage investigation into the use of mammography as a source of information to assist with microwave image interpretation as well as validation of microwave imaging techniques.

A k-Vector Approach to Sampling, Interpolation, and Approximation

NASA Astrophysics Data System (ADS)

Mortari, Daniele; Rogers, Jonathan

2013-12-01

The k-vector search technique is a method designed to perform extremely fast range searching of large databases at computational cost independent of the size of the database. k-vector search algorithms have historically found application in satellite star-tracker navigation systems which index very large star catalogues repeatedly in the process of attitude estimation. Recently, the k-vector search algorithm has been applied to numerous other problem areas including non-uniform random variate sampling, interpolation of 1-D or 2-D tables, nonlinear function inversion, and solution of systems of nonlinear equations. This paper presents algorithms in which the k-vector search technique is used to solve each of these problems in a computationally-efficient manner. In instances where these tasks must be performed repeatedly on a static (or nearly-static) data set, the proposed k-vector-based algorithms offer an extremely fast solution technique that outperforms standard methods.

Coronary Artery Anomalies and Variants: Technical Feasibility of Assessment with Coronary MR Angiography at 3 T1

PubMed Central

Gharib, Ahmed M.; Ho, Vincent B.; Rosing, Douglas R.; Herzka, Daniel A.; Stuber, Matthias; Arai, Andrew E.; Pettigrew, Roderic I.

2008-01-01

The purpose of this study was to prospectively use a whole-heart three-dimensional (3D) coronary magnetic resonance (MR) angiography technique specifically adapted for use at 3 T and a parallel imaging technique (sensitivity encoding) to evaluate coronary arterial anomalies and variants (CAAV). This HIPAA-compliant study was approved by the local institutional review board, and informed consent was obtained from all participants. Twenty-two participants (11 men, 11 women; age range, 18–62 years) were included. Ten participants were healthy volunteers, whereas 12 participants were patients suspected of having CAAV. Coronary MR angiography was performed with a 3-T MR imager. A 3D free-breathing navigator-gated and vector electrocardiographically–gated segmented k-space gradient-echo sequence with adiabatic T2 preparation pulse and parallel imaging (sensitivity encoding) was used. Whole-heart acquisitions (repetition time msec/echo time msec, 4/1.35; 20° flip angle; 1 × 1 × 2-mm acquired voxel size) lasted 10–12 minutes. Mean examination time was 41 minutes ± 14 (standard deviation). Findings included aneurysms, ectasia, arteriovenous fistulas, and anomalous origins. The 3D whole-heart acquisitions developed for use with 3 T are feasible for use in the assessment of CAAV. © RSNA, 2008 PMID:18372470

Three-dimensional bioprinting of complex cell laden alginate hydrogel structures.

PubMed

Tabriz, Atabak Ghanizadeh; Hermida, Miguel A; Leslie, Nicholas R; Shu, Wenmiao

2015-12-21

Different bioprinting techniques have been used to produce cell-laden alginate hydrogel structures, however these approaches have been limited to 2D or simple three-dimension (3D) structures. In this study, a new extrusion based bioprinting technique was developed to produce more complex alginate hydrogel structures. This was achieved by dividing the alginate hydrogel cross-linking process into three stages: primary calcium ion cross-linking for printability of the gel, secondary calcium cross-linking for rigidity of the alginate hydrogel immediately after printing and tertiary barium ion cross-linking for long-term stability of the alginate hydrogel in culture medium. Simple 3D structures including tubes were first printed to ensure the feasibility of the bioprinting technique and then complex 3D structures such as branched vascular structures were successfully printed. The static stiffness of the alginate hydrogel after printing was 20.18 ± 1.62 KPa which was rigid enough to sustain the integrity of the complex 3D alginate hydrogel structure during the printing. The addition of 60 mM barium chloride was found to significantly extend the stability of the cross-linked alginate hydrogel from 3 d to beyond 11 d without compromising the cellular viability. The results based on cell bioprinting suggested that viability of U87-MG cells was 93 ± 0.9% immediately after bioprinting and cell viability maintained above 88% ± 4.3% in the alginate hydrogel over the period of 11 d.

Robust ferromagnetism in monolayer chromium nitride

PubMed Central

Zhang, Shunhong; Li, Yawei; Zhao, Tianshan; Wang, Qian

2014-01-01

Design and synthesis of two-dimensional (2D) materials with robust ferromagnetism and biocompatibility is highly desirable due to their potential applications in spintronics and biodevices. However, the hotly pursued 2D sheets including pristine graphene, monolayer BN, and layered transition metal dichalcogenides are nonmagnetic or weakly magnetic. Using biomimetic particle swarm optimization (PSO) technique combined with ab initio calculations we predict the existence of a 2D structure, a monolayer of rocksalt-structured CrN (100) surface, which is both ferromagnetic and biocompatible. Its dynamic, thermal and magnetic stabilities are confirmed by carrying out a variety of state-of-the-art theoretical calculations. Analyses of its band structure and density of states reveal that this material is half-metallic, and the origin of the ferromagnetism is due to p-d exchange interaction between the Cr and N atoms. We demonstrate that the displayed ferromagnetism is robust against thermal and mechanical perturbations. The corresponding Curie temperature is about 675 K which is higher than that of most previously studied 2D monolayers. PMID:24912562

Three New Cytotoxic Withanolides from the Chinese Folk Medicine Physalis angulata.

PubMed

Gao, Cai-Yun; Ma, Ting; Luo, Jun; Kong, Ling-Yi

2015-12-01

Physagulides M-O, three new withanolides (1-3), were isolated from the aerial parts of Physalis angulata L. Their structures were elucidated through extensive spectroscopic techniques, including 1D and 2D NMR, and HRESIMS. The absolute configurations (22-R) of these new compounds were determined by CD analysis. Compounds 1 and 3 showed significant selective cytotoxic activities on the MG-63 cell line, with IC50 values of 4.28 and 5.44 μM, respectively.

New steroids from Anemarrhena asphodeloides rhizome and their α-glucosidase inhibitory activity.

PubMed

Khang, Pham Van; Phuong, Dao Mai; Ma, Lei

2017-05-01

Two new steroids were isolated from acid hydrolysis residue of the rhizomes of Anemarrhena asphodeloides. Their structures were identified on the basis of several spectroscopic analysis approaches including 1D, 2D-NMR techniques, and MS data, and by the comparison of spectral data of the known compounds. The biological activities of these two isolated compounds were explored on α-glucosidase. Compound 1 displayed 4.7 folds inhibitory activity against α-glucosidase compared with the positive control acarbose.

Crack Detection with Lamb Wave Wavenumber Analysis

NASA Technical Reports Server (NTRS)

Tian, Zhenhua; Leckey, Cara; Rogge, Matt; Yu, Lingyu

2013-01-01

In this work, we present our study of Lamb wave crack detection using wavenumber analysis. The aim is to demonstrate the application of wavenumber analysis to 3D Lamb wave data to enable damage detection. The 3D wavefields (including vx, vy and vz components) in time-space domain contain a wealth of information regarding the propagating waves in a damaged plate. For crack detection, three wavenumber analysis techniques are used: (i) two dimensional Fourier transform (2D-FT) which can transform the time-space wavefield into frequency-wavenumber representation while losing the spatial information; (ii) short space 2D-FT which can obtain the frequency-wavenumber spectra at various spatial locations, resulting in a space-frequency-wavenumber representation; (iii) local wavenumber analysis which can provide the distribution of the effective wavenumbers at different locations. All of these concepts are demonstrated through a numerical simulation example of an aluminum plate with a crack. The 3D elastodynamic finite integration technique (EFIT) was used to obtain the 3D wavefields, of which the vz (out-of-plane) wave component is compared with the experimental measurement obtained from a scanning laser Doppler vibrometer (SLDV) for verification purposes. The experimental and simulated results are found to be in close agreement. The application of wavenumber analysis on 3D EFIT simulation data shows the effectiveness of the analysis for crack detection. Keywords: : Lamb wave, crack detection, wavenumber analysis, EFIT modeling

Design of the 2D electron cyclotron emission imaging instrument for the J-TEXT tokamak.

PubMed

Pan, X M; Yang, Z J; Ma, X D; Zhu, Y L; Luhmann, N C; Domier, C W; Ruan, B W; Zhuang, G

2016-11-01

A new 2D Electron Cyclotron Emission Imaging (ECEI) diagnostic is being developed for the J-TEXT tokamak. It will provide the 2D electron temperature information with high spatial, temporal, and temperature resolution. The new ECEI instrument is being designed to support fundamental physics investigations on J-TEXT including MHD, disruption prediction, and energy transport. The diagnostic contains two dual dipole antenna arrays corresponding to F band (90-140 GHz) and W band (75-110 GHz), respectively, and comprises a total of 256 channels. The system can observe the same magnetic surface at both the high field side and low field side simultaneously. An advanced optical system has been designed which permits the two arrays to focus on a wide continuous region or two radially separate regions with high imaging spatial resolution. It also incorporates excellent field curvature correction with field curvature adjustment lenses. An overview of the diagnostic and the technical progress including the new remote control technique are presented.

Design of the 2D electron cyclotron emission imaging instrument for the J-TEXT tokamak

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

Pan, X. M.; Yang, Z. J., E-mail: yangzj@hust.edu.cn; Ma, X. D.

2016-11-15

A new 2D Electron Cyclotron Emission Imaging (ECEI) diagnostic is being developed for the J-TEXT tokamak. It will provide the 2D electron temperature information with high spatial, temporal, and temperature resolution. The new ECEI instrument is being designed to support fundamental physics investigations on J-TEXT including MHD, disruption prediction, and energy transport. The diagnostic contains two dual dipole antenna arrays corresponding to F band (90-140 GHz) and W band (75-110 GHz), respectively, and comprises a total of 256 channels. The system can observe the same magnetic surface at both the high field side and low field side simultaneously. An advancedmore » optical system has been designed which permits the two arrays to focus on a wide continuous region or two radially separate regions with high imaging spatial resolution. It also incorporates excellent field curvature correction with field curvature adjustment lenses. An overview of the diagnostic and the technical progress including the new remote control technique are presented.« less

Minor oxygenated cannabinoids from high potency Cannabis sativa L.

PubMed

Ahmed, Safwat A; Ross, Samir A; Slade, Desmond; Radwan, Mohamed M; Khan, Ikhlas A; ElSohly, Mahmoud A

2015-09-01

Nine oxygenated cannabinoids were isolated from a high potency Cannabis sativa L. variety. Structure elucidation was achieved using spectroscopic techniques, including 1D and 2D NMR, HRMS and GC-MS. These minor compounds include four hexahydrocannabinols, four tetrahydrocannabinols, and one hydroxylated cannabinol, namely 9α-hydroxyhexahydrocannabinol, 7-oxo-9α-hydroxyhexa-hydrocannabinol, 10α-hydroxyhexahydrocannabinol, 10aR-hydroxyhexahydrocannabinol, Δ(9)-THC aldehyde A, 8-oxo-Δ(9)-THC, 10aα-hydroxy-10-oxo-Δ(8)-THC, 9α-hydroxy-10-oxo-Δ(6a,10a)-THC, and 1'S-hydroxycannabinol, respectively. The latter compound showed moderate anti-MRSa (IC50 10.0 μg/mL), moderate antileishmanial (IC50 14.0 μg/mL) and mild antimalarial activity against Plasmodium falciparum (D6 clone) and P. falciparum (W2 clone) with IC50 values of 3.4 and 2.3 μg/mL, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

Electronic and Optoelectronic Applications Based on 2D Novel Anisotropic Transition Metal Dichalcogenides

PubMed Central

Gong, Chuanhui; Zhang, Yuxi; Chen, Wei; Lei, Tianyu; Pu, Junru; Dai, Liping; Wu, Chunyang; Li, Liang

2017-01-01

Abstract With the continuous exploration of 2D transition metal dichalcogenides (TMDs), novel high‐performance devices based on the remarkable electronic and optoelectronic natures of 2D TMDs are increasingly emerging. As fresh blood of 2D TMD family, anisotropic MTe2 and ReX2 (M = Mo, W, and X = S, Se) have drawn increasing attention owing to their low‐symmetry structures and charming properties of mechanics, electronics, and optoelectronics, which are suitable for the applications of field‐effect transistors (FETs), photodetectors, thermoelectric and piezoelectric applications, especially catering to anisotropic devices. Herein, a comprehensive review is introduced, concentrating on their recent progresses and various applications in recent years. First, the crystalline structure and the origin of the strong anisotropy characterized by various techniques are discussed. Specifically, the preparation of these 2D materials is presented and various growth methods are summarized. Then, high‐performance applications of these anisotropic TMDs, including FETs, photodetectors, and thermoelectric and piezoelectric applications are discussed. Finally, the conclusion and outlook of these applications are proposed. PMID:29270337

Trends in data processing of comprehensive two-dimensional chromatography: state of the art.

PubMed

Matos, João T V; Duarte, Regina M B O; Duarte, Armando C

2012-12-01

The operation of advanced chromatographic systems, namely comprehensive two-dimensional (2D) chromatography coupled to multidimensional detectors, allows achieving a great deal of data that need special care to be processed in order to characterize and quantify as much as possible the analytes under study. The aim of this review is to identify the main trends, research needs and gaps on the techniques for data processing of multidimensional data sets obtained from comprehensive 2D chromatography. The following topics have been identified as the most promising for new developments in the near future: data acquisition and handling, peak detection and quantification, measurement of overlapping of 2D peaks, and data analysis software for 2D chromatography. The rational supporting most of the data processing techniques is based on the generalization of one-dimensional (1D) chromatography although algorithms, such as the inverted watershed algorithm, use the 2D chromatographic data as such. However, for processing more complex N-way data there is a need for using more sophisticated techniques. Apart from using other concepts from 1D chromatography, which have not been tested for 2D chromatography, there is still room for new improvements and developments in algorithms and software for dealing with 2D comprehensive chromatographic data. Copyright © 2012 Elsevier B.V. All rights reserved.

[RESEARCH PROGRESS OF THREE-DIMENSIONAL PRINTING TECHNIQUE FOR SPINAL IMPLANTS].

PubMed

Lu, Qi; Yu, Binsheng

2016-09-08

To summarize the current research progress of three-dimensional (3D) printing technique for spinal implants manufacture. The recent original literature concerning technology, materials, process, clinical applications, and development direction of 3D printing technique in spinal implants was reviewed and analyzed. At present, 3D printing technologies used to manufacture spinal implants include selective laser sintering, selective laser melting, and electron beam melting. Titanium and its alloys are mainly used. 3D printing spinal implants manufactured by the above materials and technology have been successfully used in clinical. But the problems regarding safety, related complications, cost-benefit analysis, efficacy compared with traditional spinal implants, and the lack of relevant policies and regulations remain to be solved. 3D printing technique is able to provide individual and customized spinal implants for patients, which is helpful for the clinicians to perform operations much more accurately and safely. With the rapid development of 3D printing technology and new materials, more and more 3D printing spinal implants will be developed and used clinically.

3D Immersive Visualization with Astrophysical Data

NASA Astrophysics Data System (ADS)

Kent, Brian R.

2017-01-01

We present the refinement of a new 3D immersion technique for astrophysical data visualization.Methodology to create 360 degree spherical panoramas is reviewed. The 3D software package Blender coupled with Python and the Google Spatial Media module are used together to create the final data products. Data can be viewed interactively with a mobile phone or tablet or in a web browser. The technique can apply to different kinds of astronomical data including 3D stellar and galaxy catalogs, images, and planetary maps.

Capillary electrophoresis in two-dimensional separation systems: Techniques and applications.

PubMed

Kohl, Felix J; Sánchez-Hernández, Laura; Neusüß, Christian

2015-01-01

The analysis of complex samples requires powerful separation techniques. Here, 2D chromatographic separation techniques (e.g. LC-LC, GC-GC) are increasingly applied in many fields. Electrophoretic separation techniques show a different selectivity in comparison to LC and GC and very high separation efficiency. Thus, 2D separation systems containing at least one CE-based separation technique are an interesting alternative featuring potentially a high degree of orthogonality. However, the generally small volumes and strong electrical fields in CE require special coupling techniques. These technical developments are reviewed in this work, discussing benefits and drawbacks of offline and online systems. Emphasis is placed on the design of the systems, their coupling, and the detector used. Moreover, the employment of strategies to improve peak capacity, resolution, or sensitivity is highlighted. Various applications of 2D separations with CE are summarized. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A novel technique for VMAT QA with EPID in cine mode on a Varian TrueBeam linac

NASA Astrophysics Data System (ADS)

Liu, Bo; Adamson, Justus; Rodrigues, Anna; Zhou, Fugen; Yin, Fang-fang; Wu, Qiuwen

2013-10-01

Volumetric modulated arc therapy (VMAT) is a relatively new treatment modality for dynamic photon radiation therapy. Pre-treatment quality assurance (QA) is necessary and many efforts have been made to apply electronic portal imaging device (EPID)-based IMRT QA methods to VMAT. It is important to verify the gantry rotation speed during delivery as this is a new variable that is also modulated in VMAT. In this paper, we present a new technique to perform VMAT QA using an EPID. The method utilizes EPID cine mode and was tested on Varian TrueBeam in research mode. The cine images were acquired during delivery and converted to dose matrices after profile correction and dose calibration. A sub-arc corresponding to each cine image was extracted from the original plan and its portal image prediction was calculated. Several analyses were performed including 3D γ analysis (2D images + gantry angle axis), 2D γ analysis, and other statistical analyses. The method was applied to 21 VMAT photon plans of 3 photon energies. The accuracy of the cine image information was investigated. Furthermore, this method's sensitivity to machine delivery errors was studied. The pass rate (92.8 ± 1.4%) for 3D γ analysis was comparable to those from Delta4 system (99.9 ± 0.1%) under similar criteria (3%, 3 mm, 5% threshold and 2° angle to agreement) at 6 MV. The recorded gantry angle and start/stop MUs were found to have sufficient accuracy for clinical QA. Machine delivery errors can be detected through combined analyses of 3D γ, gantry angle, and percentage dose difference. In summary, we have developed and validated a QA technique that can simultaneously verify the gantry angle and delivered MLC fluence for VMAT treatment.This technique is efficient and its accuracy is comparable to other QA methods.

Bridging the gap: from 2D cell culture to 3D microengineered extracellular matrices

PubMed Central

Li, Yanfen

2016-01-01

Historically the culture of mammalian cells in the laboratory has been performed on planar substrates with media cocktails that are optimized to maintain phenotype. However, it is becoming increasingly clear that much of biology discerned from 2D studies does not translate well to the 3D microenvironment. Over the last several decades, 2D and 3D microengineering approaches have been developed that better recapitulate the complex architecture and properties of in vivo tissue. Inspired by the infrastructure of the microelectronics industry, lithographic patterning approaches have taken center stage because of the ease in which cell-sized features can be engineered on surfaces and within a broad range of biocompatible materials. Patterning and templating techniques enable precise control over extracellular matrix properties including: composition, mechanics, geometry, cell-cell contact, and diffusion. In this review article we will explore how the field of engineered extracellular matrices has evolved with the development of new hydrogel chemistry and the maturation of micro- and nano- fabrication. Guided by the spatiotemporal regulation of cell state in developing tissues, we will review the maturation of micropatterning in 2D, pseudo-3D systems, and patterning within 3D hydrogels in the context of translating the information gained from 2D systems to synthetic engineered 3D tissues. PMID:26592366

Concepts and algorithms for terminal-area traffic management

NASA Technical Reports Server (NTRS)

Erzberger, H.; Chapel, J. D.

1984-01-01

The nation's air-traffic-control system is the subject of an extensive modernization program, including the planned introduction of advanced automation techniques. This paper gives an overview of a concept for automating terminal-area traffic management. Four-dimensional (4D) guidance techniques, which play an essential role in the automated system, are reviewed. One technique, intended for on-board computer implementation, is based on application of optimal control theory. The second technique is a simplified approach to 4D guidance intended for ground computer implementation. It generates advisory messages to help the controller maintain scheduled landing times of aircraft not equipped with on-board 4D guidance systems. An operational system for the second technique, recently evaluated in a simulation, is also described.

A cost comparison analysis of adjuvant radiation therapy techniques after breast-conserving surgery.

PubMed

Lanni, Thomas; Keisch, Martin; Shah, Chirag; Wobb, Jessica; Kestin, Larry; Vicini, Frank

2013-01-01

The aim of this study is to perform a cost analysis to compare adjuvant radiation therapy schedules following breast conserving surgery. Treatment planning and delivery utilization data were modeled for a series of 10 different breast RT techniques. The whole breast (WB) regimens consisted of: (1) Wedge based WB (25 fractions [fx]), (2) WB using IMRT, (3) WBRT with a boost (B), (4) WBRT using IMRT with a B, (5) Canadian WB (16 fx) with 3D-CRT, and (6) Canadian using IMRT. The accelerated partial breast irradiation (APBI) regimens included (7): APBI using 3D-CRT, (8) IMRT, (9) single channel balloon, and (10) multi-channel balloon. Costs incurred by the payer (i.e., direct medical costs) were taken from the 2011 Medicare Fee Schedule. Among all the different regimens examined, Canadian 3D-CRT and APBI 3D-CRT were the least costly whereas WB using IMRT with a B was the most expensive. Both APBI brachytherapy techniques were less costly than conventional WB with a B. In terms of direct medical costs, the technical component accounted for most, if not all, of the disparity among the various treatments. A general trend of decreasing RT costs was observed with further reductions in overall treatment time for WBRT techniques, but not all of the alternative treatment regimens led to similar total cost savings. APBI using brachytherapy techniques was less costly than conventional WBRT with a standard boost. © 2013 Wiley Periodicals, Inc.

Improving 3d Spatial Queries Search: Newfangled Technique of Space Filling Curves in 3d City Modeling

NASA Astrophysics Data System (ADS)

Uznir, U.; Anton, F.; Suhaibah, A.; Rahman, A. A.; Mioc, D.

2013-09-01

The advantages of three dimensional (3D) city models can be seen in various applications including photogrammetry, urban and regional planning, computer games, etc.. They expand the visualization and analysis capabilities of Geographic Information Systems on cities, and they can be developed using web standards. However, these 3D city models consume much more storage compared to two dimensional (2D) spatial data. They involve extra geometrical and topological information together with semantic data. Without a proper spatial data clustering method and its corresponding spatial data access method, retrieving portions of and especially searching these 3D city models, will not be done optimally. Even though current developments are based on an open data model allotted by the Open Geospatial Consortium (OGC) called CityGML, its XML-based structure makes it challenging to cluster the 3D urban objects. In this research, we propose an opponent data constellation technique of space-filling curves (3D Hilbert curves) for 3D city model data representation. Unlike previous methods, that try to project 3D or n-dimensional data down to 2D or 3D using Principal Component Analysis (PCA) or Hilbert mappings, in this research, we extend the Hilbert space-filling curve to one higher dimension for 3D city model data implementations. The query performance was tested using a CityGML dataset of 1,000 building blocks and the results are presented in this paper. The advantages of implementing space-filling curves in 3D city modeling will improve data retrieval time by means of optimized 3D adjacency, nearest neighbor information and 3D indexing. The Hilbert mapping, which maps a subinterval of the [0, 1] interval to the corresponding portion of the d-dimensional Hilbert's curve, preserves the Lebesgue measure and is Lipschitz continuous. Depending on the applications, several alternatives are possible in order to cluster spatial data together in the third dimension compared to its clustering in 2D.

Lossless compression techniques for maskless lithography data

NASA Astrophysics Data System (ADS)

Dai, Vito; Zakhor, Avideh

2002-07-01

Future lithography systems must produce more dense chips with smaller feature sizes, while maintaining the throughput of one wafer per sixty seconds per layer achieved by today's optical lithography systems. To achieve this throughput with a direct-write maskless lithography system, using 25 nm pixels for 50 nm feature sizes, requires data rates of about 10 Tb/s. In a previous paper, we presented an architecture which achieves this data rate contingent on consistent 25 to 1 compression of lithography data, and on implementation of a decoder-writer chip with a real-time decompressor fabricated on the same chip as the massively parallel array of lithography writers. In this paper, we examine the compression efficiency of a spectrum of techniques suitable for lithography data, including two industry standards JBIG and JPEG-LS, a wavelet based technique SPIHT, general file compression techniques ZIP and BZIP2, our own 2D-LZ technique, and a simple list-of-rectangles representation RECT. Layouts rasterized both to black-and-white pixels, and to 32 level gray pixels are considered. Based on compression efficiency, JBIG, ZIP, 2D-LZ, and BZIP2 are found to be strong candidates for application to maskless lithography data, in many cases far exceeding the required compression ratio of 25. To demonstrate the feasibility of implementing the decoder-writer chip, we consider the design of a hardware decoder based on ZIP, the simplest of the four candidate techniques. The basic algorithm behind ZIP compression is Lempel-Ziv 1977 (LZ77), and the design parameters of LZ77 decompression are optimized to minimize circuit usage while maintaining compression efficiency.

Development of an analytical scheme for simazine and 2,4-D in soil and water runoff from ornamental plant nursery plots.

PubMed

Sutherland, Devon J; Stearman, G Kim; Wells, Martha J M

2003-01-01

The transport and fate of pesticides applied to ornamental plant nursery crops are not well documented. Methodology for analysis of soil and water runoff samples concomitantly containing the herbicides simazine (1-chloro-4,6-bis(ethylamino)-s-triazine) and 2,4-D ((2,4-dichlorophenoxy)acetic acid) was developed in this research to investigate the potential for runoff and leaching from ornamental nursery plots. Solid-phase extraction was used prior to analysis by gas chromatography and liquid chromatography. Chromatographic results were compared with determination by enzyme-linked immunoassay analysis. The significant analytical contributions of this research include (1) the development of a scheme using chromatographic mode sequencing for the fractionation of simazine and 2,4-D, (2) optimization of the homogeneous derivatization of 2,4-D using the methylating agent boron trifluoride in methanol as an alternative to in situ generation of diazomethane, and (3) the practical application of these techniques to field samples.

Three-dimensional virtual planning in orthognathic surgery enhances the accuracy of soft tissue prediction.

PubMed

Van Hemelen, Geert; Van Genechten, Maarten; Renier, Lieven; Desmedt, Maria; Verbruggen, Elric; Nadjmi, Nasser

2015-07-01

Throughout the history of computing, shortening the gap between the physical and digital world behind the screen has always been strived for. Recent advances in three-dimensional (3D) virtual surgery programs have reduced this gap significantly. Although 3D assisted surgery is now widely available for orthognathic surgery, one might still argue whether a 3D virtual planning approach is a better alternative to a conventional two-dimensional (2D) planning technique. The purpose of this study was to compare the accuracy of a traditional 2D technique and a 3D computer-aided prediction method. A double blind randomised prospective study was performed to compare the prediction accuracy of a traditional 2D planning technique versus a 3D computer-aided planning approach. The accuracy of the hard and soft tissue profile predictions using both planning methods was investigated. There was a statistically significant difference between 2D and 3D soft tissue planning (p < 0.05). The statistically significant difference found between 2D and 3D planning and the actual soft tissue outcome was not confirmed by a statistically significant difference between methods. The 3D planning approach provides more accurate soft tissue planning. However, the 2D orthognathic planning is comparable to 3D planning when it comes to hard tissue planning. This study provides relevant results for choosing between 3D and 2D planning in clinical practice. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Software for browsing sectioned images of a dog body and generating a 3D model.

PubMed

Park, Jin Seo; Jung, Yong Wook

2016-01-01

The goals of this study were (1) to provide accessible and instructive browsing software for sectioned images and a portable document format (PDF) file that includes three-dimensional (3D) models of an entire dog body and (2) to develop techniques for segmentation and 3D modeling that would enable an investigator to perform these tasks without the aid of a computer engineer. To achieve these goals, relatively important or large structures in the sectioned images were outlined to generate segmented images. The sectioned and segmented images were then packaged into browsing software. In this software, structures in the sectioned images are shown in detail and in real color. After 3D models were made from the segmented images, the 3D models were exported into a PDF file. In this format, the 3D models could be manipulated freely. The browsing software and PDF file are available for study by students, for lecture for teachers, and for training for clinicians. These files will be helpful for anatomical study by and clinical training of veterinary students and clinicians. Furthermore, these techniques will be useful for researchers who study two-dimensional images and 3D models. © 2015 Wiley Periodicals, Inc.

Cyber-Physical Multi-Core Optimization for Resource and Cache Effects (C2ORES)

DTIC Science & Technology

2014-03-01

DoD-sponsored ATAACK mobile cloud testbed funded through the DURIP program, which is deployed at Virginia Tech and Vanderbilt University to conduct...0.9.2. Jug was configured to use a filesystem (network file system (nfs)) backend for locking and task synchronization. 4.1.7.2 Experiment 1...and performance-aware virtual machine placement technique that is realized as cloud infrastructure middleware. The key contributions of iPlace include

Three-dimensional mapping of soil chemical characteristics at micrometric scale: Statistical prediction by combining 2D SEM-EDX data and 3D X-ray computed micro-tomographic images

NASA Astrophysics Data System (ADS)

Hapca, Simona

2015-04-01

Many soil properties and functions emerge from interactions of physical, chemical and biological processes at microscopic scales, which can be understood only by integrating techniques that traditionally are developed within separate disciplines. While recent advances in imaging techniques, such as X-ray computed tomography (X-ray CT), offer the possibility to reconstruct the 3D physical structure at fine resolutions, for the distribution of chemicals in soil, existing methods, based on scanning electron microscope (SEM) and energy dispersive X-ray detection (EDX), allow for characterization of the chemical composition only on 2D surfaces. At present, direct 3D measurement techniques are still lacking, sequential sectioning of soils, followed by 2D mapping of chemical elements and interpolation to 3D, being an alternative which is explored in this study. Specifically, we develop an integrated experimental and theoretical framework which combines 3D X-ray CT imaging technique with 2D SEM-EDX and use spatial statistics methods to map the chemical composition of soil in 3D. The procedure involves three stages 1) scanning a resin impregnated soil cube by X-ray CT, followed by precision cutting to produce parallel thin slices, the surfaces of which are scanned by SEM-EDX, 2) alignment of the 2D chemical maps within the internal 3D structure of the soil cube, and 3) development, of spatial statistics methods to predict the chemical composition of 3D soil based on the observed 2D chemical and 3D physical data. Specifically, three statistical models consisting of a regression tree, a regression tree kriging and cokriging model were used to predict the 3D spatial distribution of carbon, silicon, iron and oxygen in soil, these chemical elements showing a good spatial agreement between the X-ray grayscale intensities and the corresponding 2D SEM-EDX data. Due to the spatial correlation between the physical and chemical data, the regression-tree model showed a great potential in predicting chemical composition in particular for iron, which is generally sparsely distributed in soil. For carbon, silicon and oxygen, which are more densely distributed, the additional kriging of the regression tree residuals improved significantly the prediction, whereas prediction based on co-kriging was less consistent across replicates, underperforming regression-tree kriging. The present study shows a great potential in integrating geo-statistical methods with imaging techniques to unveil the 3D chemical structure of soil at very fine scales, the framework being suitable to be further applied to other types of imaging data such as images of biological thin sections for characterization of microbial distribution. Key words: X-ray CT, SEM-EDX, segmentation techniques, spatial correlation, 3D soil images, 2D chemical maps.

Comparison of three‐dimensional analysis and stereological techniques for quantifying lithium‐ion battery electrode microstructures

PubMed Central

TAIWO, OLUWADAMILOLA O.; FINEGAN, DONAL P.; EASTWOOD, DAVID S.; FIFE, JULIE L.; BROWN, LEON D.; DARR, JAWWAD A.; LEE, PETER D.; BRETT, DANIEL J.L.

2016-01-01

Summary Lithium‐ion battery performance is intrinsically linked to electrode microstructure. Quantitative measurement of key structural parameters of lithium‐ion battery electrode microstructures will enable optimization as well as motivate systematic numerical studies for the improvement of battery performance. With the rapid development of 3‐D imaging techniques, quantitative assessment of 3‐D microstructures from 2‐D image sections by stereological methods appears outmoded; however, in spite of the proliferation of tomographic imaging techniques, it remains significantly easier to obtain two‐dimensional (2‐D) data sets. In this study, stereological prediction and three‐dimensional (3‐D) analysis techniques for quantitative assessment of key geometric parameters for characterizing battery electrode microstructures are examined and compared. Lithium‐ion battery electrodes were imaged using synchrotron‐based X‐ray tomographic microscopy. For each electrode sample investigated, stereological analysis was performed on reconstructed 2‐D image sections generated from tomographic imaging, whereas direct 3‐D analysis was performed on reconstructed image volumes. The analysis showed that geometric parameter estimation using 2‐D image sections is bound to be associated with ambiguity and that volume‐based 3‐D characterization of nonconvex, irregular and interconnected particles can be used to more accurately quantify spatially‐dependent parameters, such as tortuosity and pore‐phase connectivity. PMID:26999804

Comparison of three-dimensional analysis and stereological techniques for quantifying lithium-ion battery electrode microstructures.

PubMed

Taiwo, Oluwadamilola O; Finegan, Donal P; Eastwood, David S; Fife, Julie L; Brown, Leon D; Darr, Jawwad A; Lee, Peter D; Brett, Daniel J L; Shearing, Paul R

2016-09-01

Lithium-ion battery performance is intrinsically linked to electrode microstructure. Quantitative measurement of key structural parameters of lithium-ion battery electrode microstructures will enable optimization as well as motivate systematic numerical studies for the improvement of battery performance. With the rapid development of 3-D imaging techniques, quantitative assessment of 3-D microstructures from 2-D image sections by stereological methods appears outmoded; however, in spite of the proliferation of tomographic imaging techniques, it remains significantly easier to obtain two-dimensional (2-D) data sets. In this study, stereological prediction and three-dimensional (3-D) analysis techniques for quantitative assessment of key geometric parameters for characterizing battery electrode microstructures are examined and compared. Lithium-ion battery electrodes were imaged using synchrotron-based X-ray tomographic microscopy. For each electrode sample investigated, stereological analysis was performed on reconstructed 2-D image sections generated from tomographic imaging, whereas direct 3-D analysis was performed on reconstructed image volumes. The analysis showed that geometric parameter estimation using 2-D image sections is bound to be associated with ambiguity and that volume-based 3-D characterization of nonconvex, irregular and interconnected particles can be used to more accurately quantify spatially-dependent parameters, such as tortuosity and pore-phase connectivity. © 2016 The Authors. Journal of Microscopy published by John Wiley & Sons Ltd on behalf of Royal Microscopical Society.

Mechanical assembly of complex, 3D mesostructures from releasable multilayers of advanced materials.

PubMed

Yan, Zheng; Zhang, Fan; Liu, Fei; Han, Mengdi; Ou, Dapeng; Liu, Yuhao; Lin, Qing; Guo, Xuelin; Fu, Haoran; Xie, Zhaoqian; Gao, Mingye; Huang, Yuming; Kim, JungHwan; Qiu, Yitao; Nan, Kewang; Kim, Jeonghyun; Gutruf, Philipp; Luo, Hongying; Zhao, An; Hwang, Keh-Chih; Huang, Yonggang; Zhang, Yihui; Rogers, John A

2016-09-01

Capabilities for assembly of three-dimensional (3D) micro/nanostructures in advanced materials have important implications across a broad range of application areas, reaching nearly every class of microsystem technology. Approaches that rely on the controlled, compressive buckling of 2D precursors are promising because of their demonstrated compatibility with the most sophisticated planar technologies, where materials include inorganic semiconductors, polymers, metals, and various heterogeneous combinations, spanning length scales from submicrometer to centimeter dimensions. We introduce a set of fabrication techniques and design concepts that bypass certain constraints set by the underlying physics and geometrical properties of the assembly processes associated with the original versions of these methods. In particular, the use of releasable, multilayer 2D precursors provides access to complex 3D topologies, including dense architectures with nested layouts, controlled points of entanglement, and other previously unobtainable layouts. Furthermore, the simultaneous, coordinated assembly of additional structures can enhance the structural stability and drive the motion of extended features in these systems. The resulting 3D mesostructures, demonstrated in a diverse set of more than 40 different examples with feature sizes from micrometers to centimeters, offer unique possibilities in device design. A 3D spiral inductor for near-field communication represents an example where these ideas enable enhanced quality ( Q ) factors and broader working angles compared to those of conventional 2D counterparts.

Mechanical assembly of complex, 3D mesostructures from releasable multilayers of advanced materials

PubMed Central

Yan, Zheng; Zhang, Fan; Liu, Fei; Han, Mengdi; Ou, Dapeng; Liu, Yuhao; Lin, Qing; Guo, Xuelin; Fu, Haoran; Xie, Zhaoqian; Gao, Mingye; Huang, Yuming; Kim, JungHwan; Qiu, Yitao; Nan, Kewang; Kim, Jeonghyun; Gutruf, Philipp; Luo, Hongying; Zhao, An; Hwang, Keh-Chih; Huang, Yonggang; Zhang, Yihui; Rogers, John A.

2016-01-01

Capabilities for assembly of three-dimensional (3D) micro/nanostructures in advanced materials have important implications across a broad range of application areas, reaching nearly every class of microsystem technology. Approaches that rely on the controlled, compressive buckling of 2D precursors are promising because of their demonstrated compatibility with the most sophisticated planar technologies, where materials include inorganic semiconductors, polymers, metals, and various heterogeneous combinations, spanning length scales from submicrometer to centimeter dimensions. We introduce a set of fabrication techniques and design concepts that bypass certain constraints set by the underlying physics and geometrical properties of the assembly processes associated with the original versions of these methods. In particular, the use of releasable, multilayer 2D precursors provides access to complex 3D topologies, including dense architectures with nested layouts, controlled points of entanglement, and other previously unobtainable layouts. Furthermore, the simultaneous, coordinated assembly of additional structures can enhance the structural stability and drive the motion of extended features in these systems. The resulting 3D mesostructures, demonstrated in a diverse set of more than 40 different examples with feature sizes from micrometers to centimeters, offer unique possibilities in device design. A 3D spiral inductor for near-field communication represents an example where these ideas enable enhanced quality (Q) factors and broader working angles compared to those of conventional 2D counterparts. PMID:27679820

Mechanical assembly of complex, 3D mesostructures from releasable multilayers of advanced materials

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

Yan, Zheng; Zhang, Fan; Liu, Fei

Capabilities for assembly of three-dimensional (3D) micro/nanostructures in advanced materials have important implications across a broad range of application areas, reaching nearly every class of microsystem technology. Approaches that rely on the controlled, compressive buckling of 2D precursors are promising because of their demonstrated compatibility with the most sophisticated planar technologies, where materials include inorganic semiconductors, polymers, metals, and various heterogeneous combinations, spanning length scales from submicrometer to centimeter dimensions. We introduce a set of fabrication techniques and design concepts that bypass certain constraints set by the underlying physics and geometrical properties of the assembly processes associated with the originalmore » versions of these methods. In particular, the use of releasable, multilayer 2D precursors provides access to complex 3D topologies, including dense architectures with nested layouts, controlled points of entanglement, and other previously unobtainable layouts. Furthermore, the simultaneous, coordinated assembly of additional structures can enhance the structural stability and drive the motion of extended features in these systems. The resulting 3D mesostructures, demonstrated in a diverse set of more than 40 different examples with feature sizes from micrometers to centimeters, offer unique possibilities in device design. In conclusion, a 3D spiral inductor for near-field communication represents an example where these ideas enable enhanced quality ( Q) factors and broader working angles compared to those of conventional 2D counterparts.« less

Mechanical assembly of complex, 3D mesostructures from releasable multilayers of advanced materials

DOE PAGES

Yan, Zheng; Zhang, Fan; Liu, Fei; ...

2016-09-23

Capabilities for assembly of three-dimensional (3D) micro/nanostructures in advanced materials have important implications across a broad range of application areas, reaching nearly every class of microsystem technology. Approaches that rely on the controlled, compressive buckling of 2D precursors are promising because of their demonstrated compatibility with the most sophisticated planar technologies, where materials include inorganic semiconductors, polymers, metals, and various heterogeneous combinations, spanning length scales from submicrometer to centimeter dimensions. We introduce a set of fabrication techniques and design concepts that bypass certain constraints set by the underlying physics and geometrical properties of the assembly processes associated with the originalmore » versions of these methods. In particular, the use of releasable, multilayer 2D precursors provides access to complex 3D topologies, including dense architectures with nested layouts, controlled points of entanglement, and other previously unobtainable layouts. Furthermore, the simultaneous, coordinated assembly of additional structures can enhance the structural stability and drive the motion of extended features in these systems. The resulting 3D mesostructures, demonstrated in a diverse set of more than 40 different examples with feature sizes from micrometers to centimeters, offer unique possibilities in device design. In conclusion, a 3D spiral inductor for near-field communication represents an example where these ideas enable enhanced quality ( Q) factors and broader working angles compared to those of conventional 2D counterparts.« less

Post-coronagraphic tip-tilt sensing for vortex phase masks: The QACITS technique

NASA Astrophysics Data System (ADS)

Huby, E.; Baudoz, P.; Mawet, D.; Absil, O.

2015-12-01

Context. Small inner working angle coronagraphs, such as the vortex phase mask, are essential to exploit the full potential of ground-based telescopes in the context of exoplanet detection and characterization. However, the drawback of this attractive feature is a high sensitivity to pointing errors, which degrades the performance of the coronagraph. Aims: We propose a tip-tilt retrieval technique based on the analysis of the final coronagraphic image, hereafter called Quadrant Analysis of Coronagraphic Images for Tip-tilt Sensing (QACITS). Methods: Under the assumption of small phase aberrations, we show that the behavior of the vortex phase mask can be simply described from the entrance pupil to the Lyot stop plane with Zernike polynomials. This convenient formalism is used to establish the theoretical basis of the QACITS technique. We performed simulations to demonstrate the validity and limits of the technique, including the case of a centrally obstructed pupil. Results: The QACITS technique principle is validated with experimental results in the case of an unobstructed circular aperture, as well as simulations in presence of a central obstruction. The typical configuration of the Keck telescope (24% central obstruction) has been simulated with additional high order aberrations. In these conditions, our simulations show that the QACITS technique is still adapted to centrally obstructed pupils and performs tip-tilt retrieval with a precision of 5 × 10-2λ/D when wavefront errors amount to λ/ 14 rms and 10-2λ/D for λ/ 70 rms errors (with λ the wavelength and D the pupil diameter). Conclusions: We have developed and demonstrated a tip-tilt sensing technique for vortex coronagraphs. The implementation of the QACITS technique is based on the analysis of the scientific image and does not require any modification of the original setup. Current facilities equipped with a vortex phase mask can thus directly benefit from this technique to improve the contrast performance close to the axis.

2D and 3D optical diagnostic techniques applied to Madonna dei Fusi by Leonardo da Vinci

NASA Astrophysics Data System (ADS)

Fontana, R.; Gambino, M. C.; Greco, M.; Marras, L.; Materazzi, M.; Pampaloni, E.; Pelagotti, A.; Pezzati, L.; Poggi, P.; Sanapo, C.

2005-06-01

3D measurement and modelling have been traditionally applied to statues, buildings, archeological sites or similar large structures, but rarely to paintings. Recently, however, 3D measurements have been performed successfully also on easel paintings, allowing to detect and document the painting's surface. We used 3D models to integrate the results of various 2D imaging techniques on a common reference frame. These applications show how the 3D shape information, complemented with 2D colour maps as well as with other types of sensory data, provide the most interesting information. The 3D data acquisition was carried out by means of two devices: a high-resolution laser micro-profilometer, composed of a commercial distance meter mounted on a scanning device, and a laser-line scanner. The 2D data acquisitions were carried out using a scanning device for simultaneous RGB colour imaging and IR reflectography, and a UV fluorescence multispectral image acquisition system. We present here the results of the techniques described, applied to the analysis of an important painting of the Italian Reinassance: `Madonna dei Fusi', attributed to Leonardo da Vinci.

Valence and L-shell photoionization of Cl-like argon using R-matrix techniques

NASA Astrophysics Data System (ADS)

Tyndall, N. B.; Ramsbottom, C. A.; Ballance, C. P.; Hibbert, A.

2016-02-01

Photoionization cross-sections are obtained using the relativistic Dirac Atomic R-matrix Codes (DARC) for all valence and L-shell energy ranges between 27 and 270 eV. A total of 557 levels arising from the dominant configurations 3s23p4, 3s3p5, 3p6, 3s23p3[3d, 4s, 4p], 3p53d, 3s23p23d2, 3s3p43d, 3s3p33d2 and 2s22p53s23p5 have been included in the target wavefunction representation of the Ar III ion, including up to 4p in the orbital basis. We also performed a smaller Breit-Pauli (BP) calculation containing the lowest 124 levels. Direct comparisons are made with previous theoretical and experimental work for both valence shell and L-shell photoionization. Excellent agreement was found for transitions involving the 2Po initial state to all allowed final states for both calculations across a range of photon energies. A number of resonant states have been identified to help analyse and explain the nature of the spectra at photon energies between 250 and 270 eV.

Great River Environmental Action team (GREAT II). Literature Review of Fish and Wildlife Resources.

DTIC Science & Technology

1980-12-01

and found that high water and impoundment conditions stimulated increased growth . Growth rates within as well as among pools were similar and growth ...water- fowl and waterbirds; other birds were included in the category General Wildlife. Bacteria were included in the category General Water Quality...Spawning and Reproduction b. Age and Growth c. Feeding Habits d. Distribution, Movement and Abundance e. Management Techniques f. Parasites and Diseases 2

Error control techniques for satellite and space communications

NASA Technical Reports Server (NTRS)

Costello, Daniel J., Jr.

1993-01-01

The results included in the Ph.D. dissertation of Dr. Fu Quan Wang, who was supported by the grant as a Research Assistant from January 1989 through December 1992 are discussed. The sections contain a brief summary of the important aspects of this dissertation, which include: (1) erasurefree sequential decoding of trellis codes; (2) probabilistic construction of trellis codes; (3) construction of robustly good trellis codes; and (4) the separability of shaping and coding.

Summary on Several Key Techniques in 3D Geological Modeling

PubMed Central

2014-01-01

Several key techniques in 3D geological modeling including planar mesh generation, spatial interpolation, and surface intersection are summarized in this paper. Note that these techniques are generic and widely used in various applications but play a key role in 3D geological modeling. There are two essential procedures in 3D geological modeling: the first is the simulation of geological interfaces using geometric surfaces and the second is the building of geological objects by means of various geometric computations such as the intersection of surfaces. Discrete geometric surfaces that represent geological interfaces can be generated by creating planar meshes first and then spatially interpolating; those surfaces intersect and then form volumes that represent three-dimensional geological objects such as rock bodies. In this paper, the most commonly used algorithms of the key techniques in 3D geological modeling are summarized. PMID:24772029

Reliable four-point flexion test and model for die-to-wafer direct bonding

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

Tabata, T., E-mail: toshiyuki.tabata@cea.fr; Sanchez, L.; Fournel, F.

2015-07-07

For many years, wafer-to-wafer (W2W) direct bonding has been very developed particularly in terms of bonding energy measurement and bonding mechanism comprehension. Nowadays, die-to-wafer (D2W) direct bonding has gained significant attention, for instance, in photonics and microelectro-mechanics, which supposes controlled and reliable fabrication processes. So, whatever the stuck materials may be, it is not obvious whether bonded D2W structures have the same bonding strength as bonded W2W ones, because of possible edge effects of dies. For that reason, it has been strongly required to develop a bonding energy measurement technique which is suitable for D2W structures. In this paper, bothmore » D2W- and W2W-type standard SiO{sub 2}-to-SiO{sub 2} direct bonding samples are fabricated from the same full-wafer bonding. Modifications of the four-point flexion test (4PT) technique and applications for measuring D2W direct bonding energies are reported. Thus, the comparison between the modified 4PT and the double-cantilever beam techniques is drawn, also considering possible impacts of the conditions of measures such as the water stress corrosion at the debonding interface and the friction error at the loading contact points. Finally, reliability of a modified technique and a new model established for measuring D2W direct bonding energies is demonstrated.« less

Atomic-scale etching of hexagonal boron nitride for device integration based on two-dimensional materials.

PubMed

Park, Hamin; Shin, Gwang Hyuk; Lee, Khang June; Choi, Sung-Yool

2018-05-29

Hexagonal boron nitride (h-BN) is considered an ideal template for electronics based on two-dimensional (2D) materials, owing to its unique properties as a dielectric film. Most studies involving h-BN and its application to electronics have focused on its synthesis using techniques such as chemical vapor deposition, the electrical analysis of its surface state, and the evaluation of its performance. Meanwhile, processing techniques including etching methods have not been widely studied despite their necessity for device fabrication processes. In this study, we propose the atomic-scale etching of h-BN for integration into devices based on 2D materials, using Ar plasma at room temperature. A controllable etching rate, less than 1 nm min-1, was achieved and the low reactivity of the Ar plasma enabled the atomic-scale etching of h-BN down to a monolayer in this top-down approach. Based on the h-BN etching technique for achieving electrical contact with the underlying molybdenum disulfide (MoS2) layer of an h-BN/MoS2 heterostructure, a top-gate MoS2 field-effect transistor (FET) with h-BN gate dielectric was fabricated and characterized by high electrical performance based on the on/off current ratio and carrier mobility.

Automated 3D ultrasound measurement of the angle of progression in labor.

PubMed

Montaguti, Elisa; Rizzo, Nicola; Pilu, Gianluigi; Youssef, Aly

2018-01-01

To assess the feasibility and reliability of an automated technique for the assessment of the angle of progression (AoP) in labor by using three-dimensional (3D) ultrasound. AoP was assessed by using 3D transperineal ultrasound by two operators in 52 women in active labor to evaluate intra- and interobserver reproducibility. Furthermore, intermethod agreement between automated and manual techniques on 3D images, and between automated technique on 3D vs 2D images were evaluated. Automated measurements were feasible in all cases. Automated measurements were considered acceptable in 141 (90.4%) out of the 156 on the first assessments and in all 156 after repeating measurements for unacceptable evaluations. The automated technique on 3D images demonstrated good intra- and interobserver reproducibility. The 3D-automated technique showed a very good agreement with the 3D manual technique. Notably, AoP calculated with the 3D automated technique were significantly wider in comparison with those measured manually on 3D images (133 ± 17° vs 118 ± 21°, p = 0.013). The assessment of the angle of progression through 3D ultrasound is highly reproducible. However, automated software leads to a systematic overestimation of AoP in comparison with the standard manual technique thus hindering its use in clinical practice in its present form.

Intensity-Modulated Radiotherapy for Craniospinal Irradiation: Target Volume Considerations, Dose Constraints, and Competing Risks

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

Parker, William; Filion, Edith; Roberge, David

2007-09-01

Purpose: To report the results of an analysis of dose received to tissues and organs outside the target volume, in the setting of spinal axis irradiation for the treatment of medulloblastoma, using three treatment techniques. Methods and Materials: Treatment plans (total dose, 23.4 Gy) for a standard two-dimensional (2D) technique, a three-dimensional (3D) technique using a 3D imaging-based target volume, and an intensity-modulated radiotherapy (IMRT) technique, were compared for 3 patients in terms of dose-volume statistics for target coverage, as well as organ at risk (OAR) and overall tissue sparing. Results: Planning target volume coverage and dose homogeneity was superiormore » for the IMRT plans for V{sub 95%} (IMRT, 100%; 3D, 96%; 2D, 98%) and V{sub 107%} (IMRT, 3%; 3D, 38%; 2D, 37%). In terms of OAR sparing, the IMRT plan was better for all organs and whole-body contour when comparing V{sub 10Gy}, V{sub 15Gy}, and V{sub 20Gy}. The 3D plan was superior for V{sub 5Gy} and below. For the heart and liver in particular, the IMRT plans provided considerable sparing in terms of V{sub 10Gy} and above. In terms of the integral dose, the IMRT plans were superior for liver (IMRT, 21.9 J; 3D, 28.6 J; 2D, 38.6 J) and heart (IMRT, 9 J; 3D, 14.1J; 2D, 19.4 J), the 3D plan for the body contour (IMRT, 349 J; 3D, 337 J; 2D, 555 J). Conclusions: Intensity-modulated radiotherapy is a valid treatment option for spinal axis irradiation. We have shown that IMRT results in sparing of organs at risk without a significant increase in integral dose.« less

Use of real time three-dimensional transesophageal echocardiography in intracardiac catheter based interventions.

PubMed

Perk, Gila; Lang, Roberto M; Garcia-Fernandez, Miguel Angel; Lodato, Joe; Sugeng, Lissa; Lopez, John; Knight, Brad P; Messika-Zeitoun, David; Shah, Sanjiv; Slater, James; Brochet, Eric; Varkey, Mathew; Hijazi, Ziyad; Marino, Nino; Ruiz, Carlos; Kronzon, Itzhak

2009-08-01

Real-time three-dimensional (RT3D) echocardiography is a recently developed technique that is being increasingly used in echocardiography laboratories. Over the past several years, improvements in transducer technologies have allowed development of a full matrix-array transducer that allows acquisition of pyramidal-shaped data sets. These data sets can be processed online and offline to allow accurate evaluation of cardiac structures, volumes, and mass. More recently, a transesophageal transducer with RT3D capabilities has been developed. This allows acquisition of high-quality RT3D images on transesophageal echocardiography (TEE). Percutaneous catheter-based procedures have gained growing acceptance in the cardiac procedural armamentarium. Advances in technology and technical skills allow increasingly complex procedures to be performed using a catheter-based approach, thus obviating the need for open-heart surgery. The authors used RT3D TEE to guide 72 catheter-based cardiac interventions. The procedures included the occlusion of atrial septal defects or patent foramen ovales (n=25), percutaneous mitral valve repair (e-valve clipping; n=3), mitral balloon valvuloplasty for mitral stenosis (n=10), left atrial appendage obliteration (n=11), left atrial or pulmonary vein ablation for atrial fibrillation (n=5), percutaneous closures of prosthetic valve dehiscence (n=10), percutaneous aortic valve replacement (n=6), and percutaneous closures of ventricular septal defects (n=2). In this review, the authors describe their experience with this technique, the added value over multiplanar two-dimensional TEE, and the pitfalls that were encountered. The main advantages found for the use RT3D TEE during catheter-based interventions were (1) the ability to visualize the entire lengths of intracardiac catheters, including the tips of all catheters and the balloons or devices they carry, along with a clear depiction of their positions in relation to other cardiac structures, and (2) the ability to ability to demonstrate certain structures in an "en face" view, which is not offered by any other currently available real-time imaging technique, enabling appreciation of the exact nature of the lesion that is undergoing intervention. RT3D TEE is a powerful new imaging tool that may become the technique of choice and the standard of care for guidance of selected percutaneous catheter-based procedures.

Analysis of thermal energy storage material with change-of-phase volumetric effects

NASA Technical Reports Server (NTRS)

Kerslake, Thomas W.; Ibrahim, Mounir B.

1990-01-01

NASA's Space Station Freedom proposed hybrid power system includes photovoltaic arrays with nickel hydrogen batteries for energy storage and solar dynamic collectors driving Brayton heat engines with change-of-phase Thermal Energy Storage (TES) devices. A TES device is comprised of multiple metallic, annular canisters which contain a eutectic composition LiF-CaF2 Phase Change Material (PCM) that melts at 1040 K. A moderately sophisticated LiF-CaF2 PCM computer model is being developed in three stages considering 1-D, 2-D, and 3-D canister geometries, respectively. The 1-D model results indicate that the void has a marked effect on the phase change process due to PCM displacement and dynamic void heat transfer resistance. Equally influential are the effects of different boundary conditions and liquid PCM natural convection. For the second stage, successful numerical techniques used in the 1-D phase change model are extended to a 2-D (r,z) PCM containment canister model. A prototypical PCM containment canister is analyzed and the results are discussed.

TH-B-204-01: Real-Time Tracking with Implanted Markers

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

Xu, Q.

Implanted markers as target surrogates have been widely used for treatment verification, as they provide safe and reliable monitoring of the inter- and intra-fractional target motion. The rapid advancement of technology requires a critical review and recommendation for the usage of implanted surrogates in current field. The symposium, also reporting an update of AAPM TG 199 - Implanted Target Surrogates for Radiation Treatment Verification, will be focusing on all clinical aspects of using the implanted target surrogates for treatment verification and related issues. A wide variety of markers available in the market will be first reviewed, including radiopaque markers, MRImore » compatible makers, non-migrating coils, surgical clips and electromagnetic transponders etc. The pros and cons of each kind will be discussed. The clinical applications of implanted surrogates will be presented based on different anatomical sites. For the lung, we will discuss gated treatments and 2D or 3D real-time fiducial tracking techniques. For the prostate, we will be focusing on 2D-3D, 3D-3D matching and electromagnetic transponder based localization techniques. For the liver, we will review techniques when patients are under gating, shallow or free breathing condition. We will review techniques when treating challenging breast cancer as deformation may occur. Finally, we will summarize potential issues related to the usage of implanted target surrogates with TG 199 recommendations. A review of fiducial migration and fiducial derived target rotation in different disease sites will be provided. The issue of target deformation, especially near the diaphragm, and related suggestions will be also presented and discussed. Learning Objectives: Knowledge of a wide variety of markers Knowledge of their application for different disease sites Understand of issues related to these applications Z. Wang: Research funding support from Brainlab AG Q. Xu: Consultant for Accuray; Q. Xu, I am a consultant for Accuray planning service.« less

TH-B-204-03: TG-199: Implanted Markers for Radiation Treatment Verification

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

Wang, Z.

Implanted markers as target surrogates have been widely used for treatment verification, as they provide safe and reliable monitoring of the inter- and intra-fractional target motion. The rapid advancement of technology requires a critical review and recommendation for the usage of implanted surrogates in current field. The symposium, also reporting an update of AAPM TG 199 - Implanted Target Surrogates for Radiation Treatment Verification, will be focusing on all clinical aspects of using the implanted target surrogates for treatment verification and related issues. A wide variety of markers available in the market will be first reviewed, including radiopaque markers, MRImore » compatible makers, non-migrating coils, surgical clips and electromagnetic transponders etc. The pros and cons of each kind will be discussed. The clinical applications of implanted surrogates will be presented based on different anatomical sites. For the lung, we will discuss gated treatments and 2D or 3D real-time fiducial tracking techniques. For the prostate, we will be focusing on 2D-3D, 3D-3D matching and electromagnetic transponder based localization techniques. For the liver, we will review techniques when patients are under gating, shallow or free breathing condition. We will review techniques when treating challenging breast cancer as deformation may occur. Finally, we will summarize potential issues related to the usage of implanted target surrogates with TG 199 recommendations. A review of fiducial migration and fiducial derived target rotation in different disease sites will be provided. The issue of target deformation, especially near the diaphragm, and related suggestions will be also presented and discussed. Learning Objectives: Knowledge of a wide variety of markers Knowledge of their application for different disease sites Understand of issues related to these applications Z. Wang: Research funding support from Brainlab AG Q. Xu: Consultant for Accuray; Q. Xu, I am a consultant for Accuray planning service.« less

TH-B-204-02: Application of Implanted Markers in Proton Therapy

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

Park, S.

Implanted markers as target surrogates have been widely used for treatment verification, as they provide safe and reliable monitoring of the inter- and intra-fractional target motion. The rapid advancement of technology requires a critical review and recommendation for the usage of implanted surrogates in current field. The symposium, also reporting an update of AAPM TG 199 - Implanted Target Surrogates for Radiation Treatment Verification, will be focusing on all clinical aspects of using the implanted target surrogates for treatment verification and related issues. A wide variety of markers available in the market will be first reviewed, including radiopaque markers, MRImore » compatible makers, non-migrating coils, surgical clips and electromagnetic transponders etc. The pros and cons of each kind will be discussed. The clinical applications of implanted surrogates will be presented based on different anatomical sites. For the lung, we will discuss gated treatments and 2D or 3D real-time fiducial tracking techniques. For the prostate, we will be focusing on 2D-3D, 3D-3D matching and electromagnetic transponder based localization techniques. For the liver, we will review techniques when patients are under gating, shallow or free breathing condition. We will review techniques when treating challenging breast cancer as deformation may occur. Finally, we will summarize potential issues related to the usage of implanted target surrogates with TG 199 recommendations. A review of fiducial migration and fiducial derived target rotation in different disease sites will be provided. The issue of target deformation, especially near the diaphragm, and related suggestions will be also presented and discussed. Learning Objectives: Knowledge of a wide variety of markers Knowledge of their application for different disease sites Understand of issues related to these applications Z. Wang: Research funding support from Brainlab AG Q. Xu: Consultant for Accuray; Q. Xu, I am a consultant for Accuray planning service.« less

TH-B-204-00: Implanted Markers for Radiation Therapy and TG 199 Update

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

NONE

Implanted markers as target surrogates have been widely used for treatment verification, as they provide safe and reliable monitoring of the inter- and intra-fractional target motion. The rapid advancement of technology requires a critical review and recommendation for the usage of implanted surrogates in current field. The symposium, also reporting an update of AAPM TG 199 - Implanted Target Surrogates for Radiation Treatment Verification, will be focusing on all clinical aspects of using the implanted target surrogates for treatment verification and related issues. A wide variety of markers available in the market will be first reviewed, including radiopaque markers, MRImore » compatible makers, non-migrating coils, surgical clips and electromagnetic transponders etc. The pros and cons of each kind will be discussed. The clinical applications of implanted surrogates will be presented based on different anatomical sites. For the lung, we will discuss gated treatments and 2D or 3D real-time fiducial tracking techniques. For the prostate, we will be focusing on 2D-3D, 3D-3D matching and electromagnetic transponder based localization techniques. For the liver, we will review techniques when patients are under gating, shallow or free breathing condition. We will review techniques when treating challenging breast cancer as deformation may occur. Finally, we will summarize potential issues related to the usage of implanted target surrogates with TG 199 recommendations. A review of fiducial migration and fiducial derived target rotation in different disease sites will be provided. The issue of target deformation, especially near the diaphragm, and related suggestions will be also presented and discussed. Learning Objectives: Knowledge of a wide variety of markers Knowledge of their application for different disease sites Understand of issues related to these applications Z. Wang: Research funding support from Brainlab AG Q. Xu: Consultant for Accuray; Q. Xu, I am a consultant for Accuray planning service.« less

3D reconstruction of internal structure of animal body using near-infrared light

NASA Astrophysics Data System (ADS)

Tran, Trung Nghia; Yamamoto, Kohei; Namita, Takeshi; Kato, Yuji; Shimizu, Koichi

2014-03-01

To realize three-dimensional (3D) optical imaging of the internal structure of animal body, we have developed a new technique to reconstruct CT images from two-dimensional (2D) transillumination images. In transillumination imaging, the image is blurred due to the strong scattering in the tissue. We had developed a scattering suppression technique using the point spread function (PSF) for a fluorescent light source in the body. In this study, we have newly proposed a technique to apply this PSF for a light source to the image of unknown light-absorbing structure. The effectiveness of the proposed technique was examined in the experiments with a model phantom and a mouse. In the phantom experiment, the absorbers were placed in the tissue-equivalent medium to simulate the light-absorbing organs in mouse body. Near-infrared light was illuminated from one side of the phantom and the image was recorded with CMOS camera from another side. Using the proposed techniques, the scattering effect was efficiently suppressed and the absorbing structure can be visualized in the 2D transillumination image. Using the 2D images obtained in many different orientations, we could reconstruct the 3D image. In the mouse experiment, an anesthetized mouse was held in an acrylic cylindrical holder. We can visualize the internal organs such as kidneys through mouse's abdomen using the proposed technique. The 3D image of the kidneys and a part of the liver were reconstructed. Through these experimental studies, the feasibility of practical 3D imaging of the internal light-absorbing structure of a small animal was verified.

Ultimate Tensile Strength as a Function of Test Rate for Various Ceramic Matrix Composites at Elevated Temperatures

NASA Technical Reports Server (NTRS)

Choi, Sung R.; Bansal, Narottam P.; Gyekenyesi, John P.

2002-01-01

Ultimate tensile strength of five different continuous fiber-reinforced ceramic composites, including SiC/BSAS (2D 2 types), SiC/MAS-5 (2D), SiC/SiC (2D enhanced), and C/SiC(2D) was determined as a function of test rate at I 100 to 1200 'C in air. All five composite materials exhibited a significant dependency of ultimate strength on test rate such that the ultimate strength decreased with decreasing test rate, similar to the behavior observed in many advanced monolithic ceramics at elevated temperatures. The application of the preloading technique as well as the prediction of life from one loading configuration (constant stress rate) to another (constant stress loading) for SiC/BSAS suggested that the overall macroscopic failure mechanism of the composites would be the one governed by a power-law type of damage evolution/accumulation, analogous to slow crack growth commonly observed in advanced monolithic ceramics.

Three-dimensional vs. two-dimensional shear-wave elastography of the testes - preliminary study on a healthy collective.

PubMed

Marcon, J; Trottmann, M; Rübenthaler, J; D'Anastasi, M; Stief, C G; Reiser, M F; Clevert, D A

2016-01-01

Shear wave elastography (SWE) and its derivative Supersonic Shear Imaging (SSI) are newer techniques for the determination of tissue elasticity by measuring the velocity of generated shear waves (SWV), which correlates positively with tissue stiffness.The techniques are integrated into many modern ultrasound systems and have been examined in the evaluation of viscoelastic properties of different organ systems. Two-dimensional shear wave elastography (2D SWE) of the testes has been found to be a useful tool in recent studies which included the determination of standard values in healthy volunteers. Three-dimensional shear wave elastography (3D SWE) is the latest development in elastography and is made possible by generation of a multiplanar three-dimensional map via volumetric acquisition with a special ultrasound transducer. This technique allows the assessment of tissue elasticity in a three-dimensional, fully accessible organ map.The aim of this preliminary study was to both evaluate the feasibility of 3D SWE and to compare 2D and 3D SWE standard values in the testes of healthy subjects. We examined the testes of healthy male volunteers (n = 32) with a mean age of 51.06±17.75 years (range 25-77 years) by B-mode ultrasound, 2D and 3D SWE techniques in September of 2016. Volunteers with a history of testicular pathologies were excluded. For all imaging procedures the SL15-4 linear transducer (bandwidth 4-15 MHz) as well as the SLV16-4 volumetric probe (bandwidth 4-16 MHz) of the Aixplorer® ultrasound device (SuperSonic Imagine, Aix-en-Provence, France) were used. Seven regions of interest (ROI, Q-Box®) within the testes were evaluated for SWV using both procedures. SWV values were described in m/s. Results were statistically evaluated using univariateanalysis. Mean SWV values were 1.05 m/s for the 2D SWE and 1.12 m/s for the 3D SWE.Comparisons of local areas delivered no statistically significant differences (p = 0.11 to p = 0.66), except for the region in the central portion in the superior part of the coronal plane (p = 0.03). Testicular volume was significanty higher by a mean of 1.72 ml when measured with 3D SWE (p = 0.001). 3D SWE proved to be a feasible diagnostic tool in the assessment of testicular tissue, providing the examiner with a fully accessible three-dimensional map in a multiplanar or multislice view. With this technique a more precise testicular imaging - especially if combined with the display of tissue stiffness in SWE - is available and therefore could improve the diagnostic work-up of scrotal masses or the routine investigation of infertile men. Further studies for a better understanding in the context of various testicular pathologies will be required.

The role of welding techniques in the biomechanical behavior of implant-supported prostheses.

PubMed

Rodrigues, Sabrina Alessandra; Presotto, Anna Gabriella Camacho; Barão, Valentim Adelino Ricardo; Consani, Rafael Leonardo Xediek; Nóbilo, Mauro Antônio Arruda; Mesquita, Marcelo Ferraz

2017-09-01

This in vitro study investigated the role of welding techniques of implant-supported prostheses in the 2D and 3D marginal misfits of prosthetic frameworks, strain induced on the mini abutment, and detorque of prosthetic screws. The correlations between the analyzed variables were also investigated. Frameworks were cast in commercially pure titanium (cp-Ti). A marginal misfit of 200μm was simulated in the working models (control group) (n=20). The 2D marginal misfit was analyzed according to the single-screw test protocol using a precision optical microscope. The 3D marginal misfit was performed by X-ray microtomography. Strain gauge analysis was performed to investigate the strain induced on the mini abutment. A digital torque meter was used for analysis of the detorque and the mean value was calculated for each framework. Afterwards, the frameworks were divided into two experimental groups (n=10): Laser (L) and TIG (T). The welding techniques were performed according to the following parameters: L (390V/9ms); T (36A/60ms). The L and T groups were reevaluated according to the marginal misfit, strain, and detorque. The results were submitted to one-way ANOVA followed by Tukey's HSD test and Person correlation analysis (α=0.05). Welding techniques statistically reduced the 2D and 3D marginal misfits of prosthetic frameworks (p<0.001), the strain induced on the mini abutment replicas (p=0.006), and improved the screw torque maintenance (p<0.001). Similar behavior was noted between L and T groups for all dependent variables (p>0.05). Positive correlations were observed between 2D and 3D marginal misfit reading methods (r=0.943, p<0.0001) and between misfit and strain (2D r=0.844, p<0.0001 and 3D r=0.864, p<0.0001). Negative correlation was observed between misfit and detorque (2D r=-0.823, p=0.003 and 3D r=-0.811, p=0.005). In conclusion, the welding techniques improved the biomechanical behavior of the implant-supported system. TIG can be an acceptable and affordable technique to reduce the misfit of 3-unit Ti frameworks. Copyright © 2017 Elsevier B.V. All rights reserved.

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

Zhang, X; Penagaricano, J; Narayanasamy, G

Purpose: Hippocampus avoidance whole brain radiotherapy (HA-WBRT) has been shown to reduce the risk of neurocognitive dysfunction. This type of treatment has the potential of insurance company payment denial due to increased cost of intensity modulated radiotherapy (IMRT), while the accepted modality for WBRT is three-dimensional conformal radiotherapy (3DCRT). The purpose of this study is to assess HA-WBRT treatment plans using 3DCRT and multi-criteria optimization (MCO) that meets the RTOG 0933 criteria. Methods: Ten patients with brain metastases at least 0.5cm away from the hippocampal avoidance region as defined in RTOG 0933 were selected in this study. HA-WBRT treatment plansmore » with MCO 3DCRT technique (MCO-3D) was generated with beam arrangements and dose constraints following the RTOG 0933 guidelines. MCO-3D plans were compared with plans using MCO IMRT techniques (MCO-IMRT) with same beam arrangements and dose constraints. Evaluation parameters included D98% D2% and dose homogeneity index of PTV, and Dmax and D100% of the hippocampi. The OAR doses were also evaluated. Results: For MCO-IMRT plans, PTV D2% and hippocampi Dmax and D100% met RTOG 0933 objectives in all ten patients (PTV D2%<37.5Gy; Hippocampi Dmax<16Gy and D100%<9Gy). One patient met the RTOG 0933 PTV D98% objective (PTV D98%>25Gy) and 9/10 patients met acceptable variation (PTV D98%<25Gy). For MCO-3D plans, PTV D2% met RTOG 0933 objective for all patients; 1/10 patient for PTV D98% and 6/10 patients for Hippocampi Dmax and 7/10 patients for hippocampi D100% met RTOG 0933 objective. All the other patients met the RTOG 0933 acceptable variation requirement. (PTV D98%<25Gy; Hippocampi Dmax<17Gy and D100%<10Gy). Conclusion: All dosimetric parameters of MCO-3D plans met the criteria of at least acceptable variation per RTOG 0933. This may be helpful in cases where there is denial of patient’s medical insurance coverage due to the use of IMRT for HA-WBRT.« less

Placental Volumetry by 2-D Sonography with a New Mathematical Formula: Prospective Study on the Shell of a Spherical Sector Model.

PubMed

Kozinszky, Zoltan; Surányi, Andrea; Péics, Hajnalka; Molnár, András; Pál, Attila

2015-08-01

The aim of this study was to determine the utility of a new mathematical model in volumetric assessment of the placenta using 2-D ultrasound. Placental volumetry was performed in a prospective cross-sectional survey by virtual organ computer-aided analysis (VOCAL) with the help of a shell-off method in 346 uncomplicated pregnancies according to STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines. Furthermore, placental thickness, length and height were measured with the 2-D technique to estimate placental volume based on the mathematical formula for the volume of "the shell of the spherical sector." Fetal size was also assessed by 2-D sonography. The placental volumes measured by 2-D and 3-D techniques had a correlation of 0.86. In the first trimester, the correlation was 0.82, and later during pregnancy, it was 0.86. Placental volumetry using "the circle-shaped shell of the spherical sector" mathematical model with 2-D ultrasound technique may be introduced into everyday practice to screen for placental volume deviations associated with adverse pregnancy outcome. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

The accuracy of a 2D and 3D dendritic tip scaling parameter in predicting the columnar to equiaxed transition (CET)

NASA Astrophysics Data System (ADS)

Seredyński, M.; Rebow, M.; Banaszek, J.

2016-09-01

The dendrite tip kinetics model accuracy relies on the reliability of the stability constant used, which is usually experimentally determined for 3D situations and applied to 2D models. The paper reports authors' attempts to cure the situation by deriving 2D dendritic tip scaling parameter for aluminium-based alloy: Al-4wt%Cu. The obtained parameter is then incorporated into the KGT dendritic growth model in order to compare it with the original 3D KGT counterpart and to derive two-dimensional and three-dimensional versions of the modified Hunt's analytical model for the columnar-to-equiaxed transition (CET). The conclusions drawn from the above analysis are further confirmed through numerical calculations of the two cases of Al-4wt%Cu metallic alloy solidification using the front tracking technique. Results, including the porous zone-under-cooled liquid front position, the calculated solutal under-cooling and a new predictor of the relative tendency to form an equiaxed zone, are shown, compared and discussed two numerical cases. The necessity to calculate sufficiently precise values of the tip scaling parameter in 2D and 3D is stressed.

Electron spin-echo techniques for the study of protein motion

NASA Astrophysics Data System (ADS)

Kar, Leela; Johnson, Michael E.; Bowman, Michael K.

Electron spin-echo (ESE) spectroscopy has been used to make the first direct measurements of spin-spin relaxation times of a spin-labeled protein at physiological temperatures. Results from experiments using maleimide-labeled deoxygenated hemoglobin (dHb) from individuals homozygous for sickle cell anemia (dHbS) have been compared with those from control experiments using dHb from normal adults (dHbA). Hb "immobilized" by ammonium sulfate precipitation and by siloxane polymer entrapment have been studied for a suitable "rigid" reference. Two-dimensional ESE (2D-ESE) experiments have been performed using all of these systems. The 2D contour plots show that 2D-ESE is sensitive to the slow motion of dHbS polymers and can differentiate it from both that of immobilized Hb and of HbA molecules in solution at the same temperature and concentration. More importantly, the 2D-ESE technique enables one to select for slower motion and thereby extract the dHbS polymer signal from the total signal generated by the heterogeneous system containing dHbS molecules in solution as well as in the polymer. Computer simulations using current slow motional theories show that detailed motional and structural information may be obtained by such studies. The considerable potential of 2D-ESE spectroscopy in the study of macromolecular motion is illustrated by comparing 2D-ESE with the nonlinear technique of saturation transfer electron paramagnetic resonance.

The 3D widgets for exploratory scientific visualization

NASA Technical Reports Server (NTRS)

Herndon, Kenneth P.; Meyer, Tom

1995-01-01

Computational fluid dynamics (CFD) techniques are used to simulate flows of fluids like air or water around such objects as airplanes and automobiles. These techniques usually generate very large amounts of numerical data which are difficult to understand without using graphical scientific visualization techniques. There are a number of commercial scientific visualization applications available today which allow scientists to control visualization tools via textual and/or 2D user interfaces. However, these user interfaces are often difficult to use. We believe that 3D direct-manipulation techniques for interactively controlling visualization tools will provide opportunities for powerful and useful interfaces with which scientists can more effectively explore their datasets. A few systems have been developed which use these techniques. In this paper, we will present a variety of 3D interaction techniques for manipulating parameters of visualization tools used to explore CFD datasets, and discuss in detail various techniques for positioning tools in a 3D scene.

[Technical advancement improves survival in patients with locally advanced non-small cell lung cancer (LA-NSCLC) receiving definitive radiotherapy].

PubMed

Wang, J B; Jiang, W; Ji, Z; Cao, J Z; Liu, L P; Men, Y; Xu, C; Wang, X Z; Hui, Z G; Liang, J; Lyu, J M; Zhou, Z M; Xiao, Z F; Feng, Q F; Chen, D F; Zhang, H X; Yin, W B; Wang, L H

2016-08-01

This study aimed to evaluate the impact of technical advancement of radiation therapy in patients with LA-NSCLC receiving definitive radiotherapy (RT). Patients treated with definitive RT (≥50 Gy) between 2000 and 2010 were retrospectively reviewed. Overall survival (OS), cancer specific survival (CSS), locoregional progression-free survival (LRPFS), distant metastasis-free survival (DMFS) and progression-free survival (PFS) were calculated and compared among patients irradiated with different techniques. Radiation-induced lung injury (RILI) and esophageal injury (RIEI) were assessed according to the National Cancer Institute Common Terminology Criteria for Adverse Events 3.0 (NCI-CTCAE 3.0). A total of 946 patients were eligible for analysis, including 288 treated with two-dimensional radiotherapy (2D-RT), 209 with three-dimensional conformal radiation therapy (3D-CRT) and 449 with intensity-modulated radiation therapy (IMRT) respectively. The median follow-up time for the whole population was 84.1 months. The median OS of 2D-RT, 3D-CRT and IMRT groups were 15.8, 19.7 and 23.3 months, respectively, with the corresponding 5-year survival rate of 8.7%, 13.0% and 18.8%, respectively (P<0.001). The univariate analysis demonstrated significantly inferior OS, LRPFS, DMFS and PFS of 2D-RT than those provided by 3D-CRT or IMRT. The univariate analysis also revealed that the IMRT group had significantly loger LRPFS and a trend toward better OS and DMFS compared with 3D-CRT. Multivariate analysis showed that TNM stage, RT technique and KPS were independent factors correlated with all survival indexes. Compared with 2D-RT, the utilization of IMRT was associated with significantly improved OS, LRPFS, DMFS as well as PFS. Compared with 3D-CRT, IMRT provided superior DMFS (P=0.035), a trend approaching significance with regard to LRPFS (P=0.073) but no statistically significant improvement on OS, CSS and PFS in multivariate analysis. The incidence rates of RILI were significantly decreased in the IMRT group (29.3% vs. 26.6% vs.14.0%, P<0.001) whereas that of RIET rates were similar (34.7% vs. 29.7% vs. 35.3%, P=0.342) among the three groups. Radiation therapy technique is a factor affecting prognosis of LA-NSCLC patients. Advanced radiation therapy technique is associated with improved tumor control and survival, and decreased radiation-induced lung toxicity.

A benzil and isoflavone from Iris tenuifolia.

PubMed

Choudhary, Muhammad Iqbal; Hareem, Sumaira; Siddiqui, Hina; Anjum, Shazia; Ali, Shamsher; Atta-Ur-Rahman; Zaidi, Mudassir Israr

2008-06-01

Two compounds, tenuifodione (1) and tenuifone (2), and 12 known compounds, izalpinin (3), alpinone (4), arborinone (5), irilin B (6), irisone A (7), irisone B (8), betavulgarin (9), beta-sitosterol (10), 5,7-dihydroxy-2',6-dimethoxyisoflavone (11), 2',5-dihdroxy-6,7-methylenedioxy flavanone (12), irisoid A (13) and ethyl-beta-d-glucopyranoside (14) were isolated from the whole plant of Iris tenuifolia Pall. All compounds, except 12, were isolated for the first time from this plant. Compounds 2, 3 and 11 have shown a considerable DPPH radical scavenging activity. Structures of these compounds were identified on the basis of spectroscopic techniques, including 2D NMR. Compounds 3, 5 and 7 were also subjected to single-crystal X-ray diffraction analysis and their structures were unambiguously deduced.

Extension of a three-dimensional viscous wing flow analysis

NASA Technical Reports Server (NTRS)

Weinberg, Bernard C.; Chen, Shyi-Yaung; Thoren, Stephen J.; Shamroth, Stephen J.

1990-01-01

Three-dimensional unsteady viscous effects can significantly influence the performance of fixed and rotary wing aircraft. These effects are important in both flows about helicopter rotors in forward flight and flows about 3-D (swept and tapered) supercritical wings. A computational procedure for calculating such flow field is developed, and therefore would be of great value in the design process as well as in understanding the corresponding flow phenomena. The procedure is based upon an alternating direction technique employing the Linearized Block Implicit method for solving 3-D viscous flow problems. In order to demonstrate the viability of this method, 2-D and 3-D problems are computed. These include the flow over a 2-D NACA 0012 airfoil under steady and oscillating conditions, and the steady, skewed, 3-D flow on a flat plate. Although actual 3-D flows over wings were not obtained, the ground work was laid for considering such flows. The description of the computational procedure and results are given.

The 2d-LCA as an alternative to x-wires

NASA Astrophysics Data System (ADS)

Puczylowski, Jaroslaw; Hölling, Michael; Peinke, Joachim

2015-11-01

The 2d-Laser Cantilever Anemometer (2d-LCA) is an innovative sensor for two-dimensional velocity measurements in fluids. It uses a micostructured cantilever made of silicon and SU-8 as a sensing element and is capable of performing mesurements with extremly high temporal resolutions up to 150kHz. The size of the cantilever defines its spatial resolution, which is in the order of 150 μm only. Another big feature is a large angular range of 180° in total. The 2d-LCA has been developed as an alternative measurement method to x-wires with the motivation to create a sensor that can operate in areas where the use of hot-wire anemometry is difficult. These areas include measurements in liquids and in near-wall or particle-laden flows. Unlike hot-wires, the resolution power of the 2d-LCA does not decrease with increasing flow velocity, making it particularly suitable for measurements in high speed flows. Comparative measurements with the 2d-LCA and hot-wires have been carried out in order to assess the performance of the new anemometer. The data of both measurement techniques were analyzed using the same stochastic methods including a spectral analysis as well as an inspection of increment statistics and structure functions. Furthermore, key parameters, such as mean values of both velocity components, angles of attack and the characteristic length scales were determined from both data sets. The analysis reveals a great agreement between both anemometers and thus confirms the new approach.

2d-LCA - an alternative to x-wires

NASA Astrophysics Data System (ADS)

Puczylowski, Jaroslaw; Hölling, Michael; Peinke, Joachim

2014-11-01

The 2d-Laser Cantilever Anemometer (2d-LCA) is an innovative sensor for two-dimensional velocity measurements in fluids. It uses a micostructured cantilever made of silicon and SU-8 as a sensing element and is capable of performing mesurements with extremly high temporal resolutions up to 150 kHz. The size of the cantilever defines its spatial resolution, which is in the order of 150 μm only. Another big feature is a large angular range of 180° in total. The 2d-LCA has been developed as an alternative measurement method to x-wires with the motivation to create a sensor that can operate in areas where the use of hot-wire anemometry is difficult. These areas include measurements in liquids and in near-wall or particle-laden flows. Unlike hot-wires, the resolution power of the 2d-LCA does not decrease with increasing flow velocity, making it particularly suitable for measurements in high speed flows. Comparative measurements with the 2d-LCA and hot-wires have been carried out in order to assess the performance of the new anemometer. The data of both measurement techniques were analyzed using the same stochastic methods including a spectral analysis as well as an inspection of increment statistics and structure functions. Furthermore, key parameters, such as mean values of both velocity components, angles of attack and the characteristic length scales were determined from both data sets. The analysis reveals a great agreement between both anemometers and thus confirms the new approach.

National Survey of Water Exercise Participants. D.C., July 5-8, 1988). Papers by U.S.S.R.

ERIC Educational Resources Information Center

Midtlyng, Joanna; Nelson, C. Van Cleave

This survey generated a profile of a typical water exercise participant. Data include: (1) subject's medical clearance for water exercise, swimming ability, physical and related problems, reasons for participation and perceived psycho-physical benefits of water exercise; (2) techniques of monitoring water exercise intensity: kinds of flotation…

Improved spatial coverage for brain 3D PRESS MRSI by automatic placement of outer-volume suppression saturation bands.

PubMed

Ozhinsky, Eugene; Vigneron, Daniel B; Nelson, Sarah J

2011-04-01

To develop a technique for optimizing coverage of brain 3D (1) H magnetic resonance spectroscopic imaging (MRSI) by automatic placement of outer-volume suppression (OVS) saturation bands (sat bands) and to compare the performance for point-resolved spectroscopic sequence (PRESS) MRSI protocols with manual and automatic placement of sat bands. The automated OVS procedure includes the acquisition of anatomic images from the head, obtaining brain and lipid tissue maps, calculating optimal sat band placement, and then using those optimized parameters during the MRSI acquisition. The data were analyzed to quantify brain coverage volume and data quality. 3D PRESS MRSI data were acquired from three healthy volunteers and 29 patients using protocols that included either manual or automatic sat band placement. On average, the automatic sat band placement allowed the acquisition of PRESS MRSI data from 2.7 times larger brain volumes than the conventional method while maintaining data quality. The technique developed helps solve two of the most significant problems with brain PRESS MRSI acquisitions: limited brain coverage and difficulty in prescription. This new method will facilitate routine clinical brain 3D MRSI exams and will be important for performing serial evaluation of response to therapy in patients with brain tumors and other neurological diseases. Copyright © 2011 Wiley-Liss, Inc.

A multimodal biometric authentication system based on 2D and 3D palmprint features

NASA Astrophysics Data System (ADS)

Aggithaya, Vivek K.; Zhang, David; Luo, Nan

2008-03-01

This paper presents a new personal authentication system that simultaneously exploits 2D and 3D palmprint features. Here, we aim to improve the accuracy and robustness of existing palmprint authentication systems using 3D palmprint features. The proposed system uses an active stereo technique, structured light, to capture 3D image or range data of the palm and a registered intensity image simultaneously. The surface curvature based method is employed to extract features from 3D palmprint and Gabor feature based competitive coding scheme is used for 2D representation. We individually analyze these representations and attempt to combine them with score level fusion technique. Our experiments on a database of 108 subjects achieve significant improvement in performance (Equal Error Rate) with the integration of 3D features as compared to the case when 2D palmprint features alone are employed.

Surface Tension Guided Hanging-Drop: Producing Controllable 3D Spheroid of High-Passaged Human Dermal Papilla Cells and Forming Inductive Microtissues for Hair-Follicle Regeneration.

PubMed

Lin, Bojie; Miao, Yong; Wang, Jin; Fan, Zhexiang; Du, Lijuan; Su, Yongsheng; Liu, Bingcheng; Hu, Zhiqi; Xing, Malcolm

2016-03-09

Human dermal papilla (DP) cells have been studied extensively when grown in the conventional monolayer. However, because of great deviation from the real in vivo three-dimensional (3D) environment, these two-dimensional (2D) grown cells tend to lose the hair-inducible capability during passaging. Hence, these 2D caused concerns have motivated the development of novel 3D culture techniques to produce cellular microtissues with suitable mimics. The hanging-drop approach is based on surface tension-based technique and the interaction between surface tension and gravity field that makes a convergence of liquid drops. This study used this technique in a converged drop to form cellular spheroids of dermal papilla cells. It leads to a controllable 3Dspheroid model for scalable fabrication of inductive DP microtissues. The optimal conditions for culturing high-passaged (P8) DP spheroids were determined first. Then, the morphological, histological and functional studies were performed. In addition, expressions of hair-inductive markers including alkaline phosphatase, α-smooth muscle actin and neural cell adhesion molecule were also analyzed by quantitative RT-PCR, immunostaining and immunoblotting. Finally, P8-DP microtissues were coimplanted with newborn mouse epidermal cells (EPCs) into nude mice. Our results indicated that the formation of 3D microtissues not only endowed P8-DP microtissues many similarities to primary DP, but also confer these microtissues an enhanced ability to induce hair-follicle (HF) neogenesis in vivo. This model provides a potential to elucidate the native biology of human DP, and also shows the promising for the controllable and scalable production of inductive DP cells applied in future follicle regeneration.

3D-Printing: an emerging and a revolutionary technology in pharmaceuticals.

PubMed

Singhvi, Gautam; Patil, Shalini; Girdhar, Vishal; Chellappan, Dinesh K; Gupta, Gaurav; Dua, Kamal

2018-06-01

One of the novel and progressive technology employed in pharmaceutical manufacturing, design of medical device and tissue engineering is threedimensional (3D) printing. 3D printing technologies provide great advantages in 3D scaffolds fabrication over traditional methods in the control of pore size, porosity, and interconnectivity. Various techniques of 3Dprinting include powder bed fusion, fused deposition modeling, binder deposition, inkjet printing, photopolymerization and many others which are still evolving. 3Dprinting technique been employed in developing immediate release products, various systems to deliver multiple release modalities etc. 3D printing has opened the door for new generation of customized drug delivery with builtin flexibility for safer and effective therapy. Our minireview provides a quick snapshot on an overview of 3D printing, various techniques employed, applications and its advancements in pharmaceutical sciences.

Ingasaponin, a complex triterpenoid saponin with immunological adjuvant activity from Inga laurina.

PubMed

Cruz, Maria de Fátima Simão Jucá; Pereira, Gabriela Moysés; Ribeiro, Marcela Gonçalves; da Silva, Ari Miranda; Tinoco, Luzineide Wanderley; da Silva, Bernadete Pereira; Parente, José Paz

2016-02-01

As part of our search of bioactive saponins from Brazilian plants, phytochemical study of the seeds of Inga laurina led to the isolation of a new complex triterpenoid saponin, named ingasaponin. It is the first saponin isolated from a species of Inga genus. It was isolated by using chromatographic methods and its structural elucidation was performed using detailed analyses of (1)H and (13)C NMR spectra including 2D-NMR spectroscopic techniques and chemical conversions. Its structure was established as 21-[[(2E,6S)-6-[[6-deoxy-4-O-[(2E,6S)-6-[(β-D-glucopyranosyl)oxy]-2,6-dimethyl-1-oxo-2,7-octadienyl]-[(β-D-glucopyranosyl)oxy]-2,6-dimethyl-1-oxo-2,7-octadienyl]-[(β-D-glucopyranosyl)oxy]-2,6-dimethyl-1-oxo-2,7-octadienyl]-[(β-D-glucopyranosyl)oxy]-2-(hydroxymethyl)-6-methyl-1-oxo-2,7-octadienyl]oxy]-16-hydroxy-3-[[O-β-D-xylopyranosyl-(1 → 2)-O-α-L-arabinopyranosyl-(1 → 6)-2-(acetylamino)-2-deoxy-β-D-glucopyranosyl]oxy]-(3β,16α,21β)-olean-12-en-28-oic acid O-α-L-arabinofuranosyl-(1 → 4)-O-[β-D-glucopyranosyl-(1 → 3)]-O-6-deoxy-α-L-mannopyranosyl-(1 → 2)-β-D-glucopyranosyl ester (1). The hemolytic potential of 1 was evaluated using in vitro assays, and its adjuvant activity on the cellular immune response against ovalbumin antigen was investigated using in vivo models. Copyright © 2015 Elsevier Ltd. All rights reserved.

Chalcogenide glass-on-graphene photonics

NASA Astrophysics Data System (ADS)

Lin, Hongtao; Song, Yi; Huang, Yizhong; Kita, Derek; Deckoff-Jones, Skylar; Wang, Kaiqi; Li, Lan; Li, Junying; Zheng, Hanyu; Luo, Zhengqian; Wang, Haozhe; Novak, Spencer; Yadav, Anupama; Huang, Chung-Che; Shiue, Ren-Jye; Englund, Dirk; Gu, Tian; Hewak, Daniel; Richardson, Kathleen; Kong, Jing; Hu, Juejun

2017-12-01

Two-dimensional (2D) materials are of tremendous interest to integrated photonics, given their singular optical characteristics spanning light emission, modulation, saturable absorption and nonlinear optics. To harness their optical properties, these atomically thin materials are usually attached onto prefabricated devices via a transfer process. Here, we present a new route for 2D material integration with planar photonics. Central to this approach is the use of chalcogenide glass, a multifunctional material that can be directly deposited and patterned on a wide variety of 2D materials and can simultaneously function as the light-guiding medium, a gate dielectric and a passivation layer for 2D materials. Besides achieving improved fabrication yield and throughput compared with the traditional transfer process, our technique also enables unconventional multilayer device geometries optimally designed for enhancing light-matter interactions in the 2D layers. Capitalizing on this facile integration method, we demonstrate a series of high-performance glass-on-graphene devices including ultra-broadband on-chip polarizers, energy-efficient thermo-optic switches, as well as graphene-based mid-infrared waveguide-integrated photodetectors and modulators.

Novel Biomaterials Used in Medical 3D Printing Techniques.

PubMed

Tappa, Karthik; Jammalamadaka, Udayabhanu

2018-02-07

The success of an implant depends on the type of biomaterial used for its fabrication. An ideal implant material should be biocompatible, inert, mechanically durable, and easily moldable. The ability to build patient specific implants incorporated with bioactive drugs, cells, and proteins has made 3D printing technology revolutionary in medical and pharmaceutical fields. A vast variety of biomaterials are currently being used in medical 3D printing, including metals, ceramics, polymers, and composites. With continuous research and progress in biomaterials used in 3D printing, there has been a rapid growth in applications of 3D printing in manufacturing customized implants, prostheses, drug delivery devices, and 3D scaffolds for tissue engineering and regenerative medicine. The current review focuses on the novel biomaterials used in variety of 3D printing technologies for clinical applications. Most common types of medical 3D printing technologies, including fused deposition modeling, extrusion based bioprinting, inkjet, and polyjet printing techniques, their clinical applications, different types of biomaterials currently used by researchers, and key limitations are discussed in detail.

Inverse-optimized 3D conformal planning: Minimizing complexity while achieving equivalence with beamlet IMRT in multiple clinical sites

PubMed Central

Fraass, Benedick A.; Steers, Jennifer M.; Matuszak, Martha M.; McShan, Daniel L.

2012-01-01

Purpose: Inverse planned intensity modulated radiation therapy (IMRT) has helped many centers implement highly conformal treatment planning with beamlet-based techniques. The many comparisons between IMRT and 3D conformal (3DCRT) plans, however, have been limited because most 3DCRT plans are forward-planned while IMRT plans utilize inverse planning, meaning both optimization and delivery techniques are different. This work avoids that problem by comparing 3D plans generated with a unique inverse planning method for 3DCRT called inverse-optimized 3D (IO-3D) conformal planning. Since IO-3D and the beamlet IMRT to which it is compared use the same optimization techniques, cost functions, and plan evaluation tools, direct comparisons between IMRT and simple, optimized IO-3D plans are possible. Though IO-3D has some similarity to direct aperture optimization (DAO), since it directly optimizes the apertures used, IO-3D is specifically designed for 3DCRT fields (i.e., 1–2 apertures per beam) rather than starting with IMRT-like modulation and then optimizing aperture shapes. The two algorithms are very different in design, implementation, and use. The goals of this work include using IO-3D to evaluate how close simple but optimized IO-3D plans come to nonconstrained beamlet IMRT, showing that optimization, rather than modulation, may be the most important aspect of IMRT (for some sites). Methods: The IO-3D dose calculation and optimization functionality is integrated in the in-house 3D planning/optimization system. New features include random point dose calculation distributions, costlet and cost function capabilities, fast dose volume histogram (DVH) and plan evaluation tools, optimization search strategies designed for IO-3D, and an improved, reimplemented edge/octree calculation algorithm. The IO-3D optimization, in distinction to DAO, is designed to optimize 3D conformal plans (one to two segments per beam) and optimizes MLC segment shapes and weights with various user-controllable search strategies which optimize plans without beamlet or pencil beam approximations. IO-3D allows comparisons of beamlet, multisegment, and conformal plans optimized using the same cost functions, dose points, and plan evaluation metrics, so quantitative comparisons are straightforward. Here, comparisons of IO-3D and beamlet IMRT techniques are presented for breast, brain, liver, and lung plans. Results: IO-3D achieves high quality results comparable to beamlet IMRT, for many situations. Though the IO-3D plans have many fewer degrees of freedom for the optimization, this work finds that IO-3D plans with only one to two segments per beam are dosimetrically equivalent (or nearly so) to the beamlet IMRT plans, for several sites. IO-3D also reduces plan complexity significantly. Here, monitor units per fraction (MU/Fx) for IO-3D plans were 22%–68% less than that for the 1 cm × 1 cm beamlet IMRT plans and 72%–84% than the 0.5 cm × 0.5 cm beamlet IMRT plans. Conclusions: The unique IO-3D algorithm illustrates that inverse planning can achieve high quality 3D conformal plans equivalent (or nearly so) to unconstrained beamlet IMRT plans, for many sites. IO-3D thus provides the potential to optimize flat or few-segment 3DCRT plans, creating less complex optimized plans which are efficient and simple to deliver. The less complex IO-3D plans have operational advantages for scenarios including adaptive replanning, cases with interfraction and intrafraction motion, and pediatric patients. PMID:22755717

Metalloproteomics: Forward and Reverse Approaches in Metalloprotein Structural and Functional Characterization

PubMed Central

Shi, Wuxian; Chance, Mark R.

2010-01-01

About one-third of all proteins are associated with a metal. Metalloproteomics is defined as the structural and functional characterization of metalloproteins on a genome-wide scale. The methodologies utilized in metalloproteomics, including both forward (bottom-up) and reverse (top-down) technologies, to provide information on the identity, quantity and function of metalloproteins are discussed. Important techniques frequently employed in metalloproteomics include classical proteomics tools such as mass spectrometry and 2-D gels, immobilized-metal affinity chromatography, bioinformatics sequence analysis and homology modeling, X-ray absorption spectroscopy and other synchrotron radiation based tools. Combinative applications of these techniques provide a powerful approach to understand the function of metalloproteins. PMID:21130021

Prospective study aiming to compare 2D mammography and tomosynthesis + synthesized mammography in terms of cancer detection and recall. From double reading of 2D mammography to single reading of tomosynthesis.

PubMed

Romero Martín, Sara; Raya Povedano, Jose Luis; Cara García, María; Santos Romero, Ana Luz; Pedrosa Garriguet, Margarita; Álvarez Benito, Marina

2018-06-01

To evaluate tomosynthesis compared with 2D-mammography in cancer detection and recalls in a screening-programme, and assess performing synthesized instead of 2D, and compare double reading of 2D with single reading of tomosynthesis. Women (age 50-69 years) participating in the screening-programme were included. 2D-mammography and tomosynthesis were performed. There were four reading models: 2D-mammography (first); 2D-mammography (second); tomosynthesis + synthesized (third); tomosynthesis + synthesized + 2D (fourth reading). Paired double reading of 2D (first+second) and tomosynthesis (third+fourth) were analysed. In 16,067 participants, there were 98 cancers and 1,196 recalls. Comparing double reading of 2D with single reading of tomosynthesis, there was an increase of 12.6 % in cancer detection with the third reading (p= 0.043) and 6.9 % with the fourth reading (p=0.210), and a decrease in recalls of 40.5 % (p<0.001) and 44.4 % (p<0.001), respectively. With double reading of both techniques, there was an increase in cancer detection of 17.4 % (p = 0.004) and a decrease in recalls of 12.5 % (p = 0.001) with tomosynthesis. Single reading of tomosynthesis plus synthesized increased cancer detection and decreased recalls compared with double reading 2D. 2D did not improve results when added to tomosynthesis. • Tomosynthesis increases cancer detection and decreases recall rates versus 2D mammography. • Synthesized-mammography avoids performing 2D, showing higher cancer detection. • Single reading of tomosynthesis + synthesized is feasible as a new practice.

On the Performance Evaluation of 3D Reconstruction Techniques from a Sequence of Images

NASA Astrophysics Data System (ADS)

Eid, Ahmed; Farag, Aly

2005-12-01

The performance evaluation of 3D reconstruction techniques is not a simple problem to solve. This is not only due to the increased dimensionality of the problem but also due to the lack of standardized and widely accepted testing methodologies. This paper presents a unified framework for the performance evaluation of different 3D reconstruction techniques. This framework includes a general problem formalization, different measuring criteria, and a classification method as a first step in standardizing the evaluation process. Performance characterization of two standard 3D reconstruction techniques, stereo and space carving, is also presented. The evaluation is performed on the same data set using an image reprojection testing methodology to reduce the dimensionality of the evaluation domain. Also, different measuring strategies are presented and applied to the stereo and space carving techniques. These measuring strategies have shown consistent results in quantifying the performance of these techniques. Additional experiments are performed on the space carving technique to study the effect of the number of input images and the camera pose on its performance.

Feasibility of using an inversion-recovery ultrashort echo time (UTE) sequence for quantification of glenoid bone loss.

PubMed

Ma, Ya-Jun; West, Justin; Nazaran, Amin; Cheng, Xin; Hoenecke, Heinz; Du, Jiang; Chang, Eric Y

2018-02-02

To utilize the 3D inversion recovery prepared ultrashort echo time with cones readout (IR-UTE-Cones) MRI technique for direct imaging of lamellar bone with comparison to the gold standard of computed tomography (CT). CT and MRI was performed on 11 shoulder specimens and three patients. Five specimens had imaging performed before and after glenoid fracture (osteotomy). 2D and 3D volume-rendered CT images were reconstructed and conventional T1-weighted and 3D IR-UTE-Cones MRI techniques were performed. Glenoid widths and defects were independently measured by two readers using the circle method. Measurements were compared with those made from 3D CT datasets. Paired-sample Student's t tests and intraclass correlation coefficients were performed. In addition, 2D CT and 3D IR-UTE-Cones MRI datasets were linearly registered, digitally overlaid, and compared in consensus by these two readers. Compared with the reference standard (3D CT), glenoid bone diameter measurements made on 2D CT and 3D IR-UTE-Cones were not significantly different for either reader, whereas T1-weighted images underestimated the diameter (mean difference of 0.18 cm, p = 0.003 and 0.16 cm, p = 0.022 for readers 1 and 2, respectively). However, mean margin of error for measuring glenoid bone loss was small for all modalities (range, 1.46-3.92%). All measured ICCs were near perfect. Digitally registered 2D CT and 3D IR-UTE-Cones MRI datasets yielded essentially perfect congruity between the two modalities. The 3D IR-UTE-Cones MRI technique selectively visualizes lamellar bone, produces similar contrast to 2D CT imaging, and compares favorably to measurements made using 2D and 3D CT.

Image cross-correlation using COSI-Corr: A versatile technique to monitor and quantity surface deformation in space and time

NASA Astrophysics Data System (ADS)

Leprince, S.; Ayoub, F.; Avouac, J.

2011-12-01

We have developed a suite of algorithms for precise Co-registration of Optically Sensed Images and Correlation (COSI-Corr) which were implemented in a software package first released to the academic community in 2007. Its capability for accurate surface deformation measurement has proved useful for a wide variety of applications. We present the fundamental principles of COSI-Corr, which are the key ingredients to achieve sub-pixel registration and sub-pixel measurement accuracy, and we show how they can be applied to various types of images to extract 2D, 3D, or even 4D deformation fields of a given surface. Examples are drawn from recent collaborative studies and include: (1) The study of the Icelandic Krafla rifting crisis that occurred from 1975 to 1984 where we used a combination of archived airborne photographs, declassified spy satellite imagery, and modern satellite acquisitions to propose a detailed 2D displacement field of the ground; (2) The estimation of glacial velocities from fast New Zealand glaciers using successive ASTER acquisitions; (3) The derivation of sand dunes migration rates; (4) The estimation of ocean swell velocity taking advantage of the short time delay between the acquisition of different spectral bands on the SPOT 5 satellite; (5) The derivation of the full 3D ground displacement field induced by the 2010 Mw 7.2 El Mayor-Cucapah Earthquake, as recorded from pre- and post-event lidar acquisitions; (6) And, the estimation of 2D in plane deformation of mechanical samples under stress in the lab. Finally, we conclude by highlighting the potential future and implication of applying such correlation techniques on a large scale to provide global monitoring of our environment.

Rotator cuff tear shape characterization: a comparison of two-dimensional imaging and three-dimensional magnetic resonance reconstructions.

PubMed

Gyftopoulos, Soterios; Beltran, Luis S; Gibbs, Kevin; Jazrawi, Laith; Berman, Phillip; Babb, James; Meislin, Robert

2016-01-01

The purpose of this study was to see if 3-dimensional (3D) magnetic resonance imaging (MRI) could improve our understanding of rotator cuff tendon tear shapes. We believed that 3D MRI would be more accurate than two-dimensional (2D) MRI for classifying tear shapes. We performed a retrospective review of MRI studies of patients with arthroscopically proven full-thickness rotator cuff tears. Two orthopedic surgeons reviewed the information for each case, including scope images, and characterized the shape of the cuff tear into crescent, longitudinal, U- or L-shaped longitudinal, and massive type. Two musculoskeletal radiologists reviewed the corresponding MRI studies independently and blind to the arthroscopic findings and characterized the shape on the basis of the tear's retraction and size using 2D MRI. The 3D reconstructions of each cuff tear were reviewed by each radiologist to characterize the shape. Statistical analysis included 95% confidence intervals and intraclass correlation coefficients. The study reviewed 34 patients. The accuracy for differentiating between crescent-shaped, longitudinal, and massive tears using measurements on 2D MRI was 70.6% for reader 1 and 67.6% for reader 2. The accuracy for tear shape characterization into crescent and longitudinal U- or L-shaped using 3D MRI was 97.1% for reader 1 and 82.4% for reader 2. When further characterizing the longitudinal tears as massive or not using 3D MRI, both readers had an accuracy of 76.9% (10 of 13). The overall accuracy of 3D MRI was 82.4% (56 of 68), significantly different (P = .021) from 2D MRI accuracy (64.7%). Our study has demonstrated that 3D MR reconstructions of the rotator cuff improve the accuracy of characterizing rotator cuff tear shapes compared with current 2D MRI-based techniques. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Identification of geometric faces in hand-sketched 3D objects containing curved lines

NASA Astrophysics Data System (ADS)

El-Sayed, Ahmed M.; Wahdan, A. A.; Youssif, Aliaa A. A.

2017-07-01

The reconstruction of 3D objects from 2D line drawings is regarded as one of the key topics in the field of computer vision. The ongoing research is mainly focusing on the reconstruction of 3D objects that are mapped only from 2D straight lines, and that are symmetric in nature. Commonly, this approach only produces basic and simple shapes that are mostly flat or rather polygonized in nature, which is normally attributed to inability to handle curves. To overcome the above-mentioned limitations, a technique capable of handling non-symmetric drawings that encompass curves is considered. This paper discusses a novel technique that can be used to reconstruct 3D objects containing curved lines. In addition, it highlights an application that has been developed in accordance with the suggested technique that can convert a freehand sketch to a 3D shape using a mobile phone.

Comparative analysis of 2D spatio-temporal visualisation techniques for the pulsed THz-radiation field using an electro-optic crystal

NASA Astrophysics Data System (ADS)

Ushakov, A. A.; Chizhov, P. A.; Bukin, V. V.; Garnov, S. V.; Savel'ev, A. B.

2018-05-01

Two 2D techniques for visualising the field of pulsed THz radiation ('shadow' and 'interferometric'), which are based on the linear electro-optical effect with application of a ZnTe detector crystal 1 × 1 cm in size, are compared. The noise level and dynamic range for the aforementioned techniques are analysed and their applicability limits are discussed.

Platform for Post-Processing Waveform-Based NDE

NASA Technical Reports Server (NTRS)

Roth, Don J.

2010-01-01

Signal- and image-processing methods are commonly needed to extract information from the waves, improve resolution of, and highlight defects in an image. Since some similarity exists for all waveform-based nondestructive evaluation (NDE) methods, it would seem that a common software platform containing multiple signal- and image-processing techniques to process the waveforms and images makes sense where multiple techniques, scientists, engineers, and organizations are involved. NDE Wave & Image Processor Version 2.0 software provides a single, integrated signal- and image-processing and analysis environment for total NDE data processing and analysis. It brings some of the most useful algorithms developed for NDE over the past 20 years into a commercial-grade product. The software can import signal/spectroscopic data, image data, and image series data. This software offers the user hundreds of basic and advanced signal- and image-processing capabilities including esoteric 1D and 2D wavelet-based de-noising, de-trending, and filtering. Batch processing is included for signal- and image-processing capability so that an optimized sequence of processing operations can be applied to entire folders of signals, spectra, and images. Additionally, an extensive interactive model-based curve-fitting facility has been included to allow fitting of spectroscopy data such as from Raman spectroscopy. An extensive joint-time frequency module is included for analysis of non-stationary or transient data such as that from acoustic emission, vibration, or earthquake data.

Recent Advances in Ultrathin Two-Dimensional Nanomaterials.

PubMed

Tan, Chaoliang; Cao, Xiehong; Wu, Xue-Jun; He, Qiyuan; Yang, Jian; Zhang, Xiao; Chen, Junze; Zhao, Wei; Han, Shikui; Nam, Gwang-Hyeon; Sindoro, Melinda; Zhang, Hua

2017-05-10

Since the discovery of mechanically exfoliated graphene in 2004, research on ultrathin two-dimensional (2D) nanomaterials has grown exponentially in the fields of condensed matter physics, material science, chemistry, and nanotechnology. Highlighting their compelling physical, chemical, electronic, and optical properties, as well as their various potential applications, in this Review, we summarize the state-of-art progress on the ultrathin 2D nanomaterials with a particular emphasis on their recent advances. First, we introduce the unique advances on ultrathin 2D nanomaterials, followed by the description of their composition and crystal structures. The assortments of their synthetic methods are then summarized, including insights on their advantages and limitations, alongside some recommendations on suitable characterization techniques. We also discuss in detail the utilization of these ultrathin 2D nanomaterials for wide ranges of potential applications among the electronics/optoelectronics, electrocatalysis, batteries, supercapacitors, solar cells, photocatalysis, and sensing platforms. Finally, the challenges and outlooks in this promising field are featured on the basis of its current development.

A new detection scheme for ultrafast 2D J-resolved spectroscopy

NASA Astrophysics Data System (ADS)

Giraudeau, Patrick; Akoka, Serge

2007-06-01

Recent ultrafast techniques enable 2D NMR spectra to be obtained in a single scan. A modification of the detection scheme involved in this technique is proposed, permitting the achievement of 2D 1H J-resolved spectra in 500 ms. The detection gradient echoes are substituted by spin echoes to obtain spectra where the coupling constants are encoded along the direct ν2 domain. The use of this new J-resolved detection block after continuous phase-encoding excitation schemes is discussed in terms of resolution and sensitivity. J-resolved spectra obtained on cinnamic acid and 3-ethyl bromopropionate are presented, revealing the expected 2D J-patterns with coupling constants as small as 2 Hz.

Efficient 3D inversions using the Richards equation

NASA Astrophysics Data System (ADS)

Cockett, Rowan; Heagy, Lindsey J.; Haber, Eldad

2018-07-01

Fluid flow in the vadose zone is governed by the Richards equation; it is parameterized by hydraulic conductivity, which is a nonlinear function of pressure head. Investigations in the vadose zone typically require characterizing distributed hydraulic properties. Water content or pressure head data may include direct measurements made from boreholes. Increasingly, proxy measurements from hydrogeophysics are being used to supply more spatially and temporally dense data sets. Inferring hydraulic parameters from such datasets requires the ability to efficiently solve and optimize the nonlinear time domain Richards equation. This is particularly important as the number of parameters to be estimated in a vadose zone inversion continues to grow. In this paper, we describe an efficient technique to invert for distributed hydraulic properties in 1D, 2D, and 3D. Our technique does not store the Jacobian matrix, but rather computes its product with a vector. Existing literature for the Richards equation inversion explicitly calculates the sensitivity matrix using finite difference or automatic differentiation, however, for large scale problems these methods are constrained by computation and/or memory. Using an implicit sensitivity algorithm enables large scale inversion problems for any distributed hydraulic parameters in the Richards equation to become tractable on modest computational resources. We provide an open source implementation of our technique based on the SimPEG framework, and show it in practice for a 3D inversion of saturated hydraulic conductivity using water content data through time.

Contrast-enhanced MR Angiography of the Abdomen with Highly Accelerated Acquisition Techniques

PubMed Central

Mostardi, Petrice M.; Glockner, James F.; Young, Phillip M.

2011-01-01

Purpose: To demonstrate that highly accelerated (net acceleration factor [Rnet] ≥ 10) acquisition techniques can be used to generate three-dimensional (3D) subsecond timing images, as well as diagnostic-quality high-spatial-resolution contrast material–enhanced (CE) renal magnetic resonance (MR) angiograms with a single split dose of contrast material. Materials and Methods: All studies were approved by the institutional review board and were HIPAA compliant; written consent was obtained from all participants. Twenty-two studies were performed in 10 female volunteers (average age, 47 years; range, 27–62 years) and six patients with renovascular disease (three women; average age, 48 years; range, 37–68 years; three men; average age, 60 years; range, 50–67 years; composite average age, 54 years; range, 38–68 years). The two-part protocol consisted of a low-dose (2 mL contrast material) 3D timing image with approximate 1-second frame time, followed by a high-spatial-resolution (1.0–1.6-mm isotropic voxels) breath-hold 3D renal MR angiogram (18 mL) over the full abdominal field of view. Both acquisitions used two-dimensional (2D) sensitivity encoding acceleration factor (R) of eight and 2D homodyne (HD) acceleration (RHD) of 1.4–1.8 for Rnet = R · RHD of 10 or higher. Statistical analysis included determination of mean values and standard deviations of image quality scores performed by two experienced reviewers with use of eight evaluation criteria. Results: The 2-mL 3D time-resolved image successfully portrayed progressive arterial filling in all 22 studies and provided an anatomic overview of the vasculature. Successful timing was also demonstrated in that the renal MR angiogram showed adequate or excellent portrayal of the main renal arteries in 21 of 22 studies. Conclusion: Two-dimensional acceleration techniques with Rnet of 10 or higher can be used in CE MR angiography to acquire (a) a 3D image series with 1-second frame time, allowing accurate bolus timing, and (b) a high-spatial-resolution renal angiogram. © RSNA, 2011 Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11110242/-/DC1 PMID:21900616

Diuretic-enhanced gadolinium excretory MR urography: comparison of conventional gradient-echo sequences and echo-planar imaging.

PubMed

Nolte-Ernsting, C C; Tacke, J; Adam, G B; Haage, P; Jung, P; Jakse, G; Günther, R W

2001-01-01

The aim of this study was to investigate the utility of different gadolinium-enhanced T1-weighted gradient-echo techniques in excretory MR urography. In 74 urologic patients, excretory MR urography was performed using various T1-weighted gradient-echo (GRE) sequences after injection of gadolinium-DTPA and low-dose furosemide. The examinations included conventional GRE sequences and echo-planar imaging (GRE EPI), both obtained with 3D data sets and 2D projection images. Breath-hold acquisition was used primarily. In 20 of 74 examinations, we compared breath-hold imaging with respiratory gating. Breath-hold imaging was significantly superior to respiratory gating for the visualization of pelvicaliceal systems, but not for the ureters. Complete MR urograms were obtained within 14-20 s using 3D GRE EPI sequences and in 20-30 s with conventional 3D GRE sequences. Ghost artefacts caused by ureteral peristalsis often occurred with conventional 3D GRE imaging and were almost completely suppressed in EPI sequences (p < 0.0001). Susceptibility effects were more pronounced on GRE EPI MR urograms and calculi measured 0.8-21.7% greater in diameter compared with conventional GRE sequences. Increased spatial resolution degraded the image quality only in GRE-EPI urograms. In projection MR urography, the entire pelvicaliceal system was imaged by acquisition of a fast single-slice sequence and the conventional 2D GRE technique provided superior morphological accuracy than 2D GRE EPI projection images (p < 0.0003). Fast 3D GRE EPI sequences improve the clinical practicability of excretory MR urography especially in old or critically ill patients unable to suspend breathing for more than 20 s. Conventional GRE sequences are superior to EPI in high-resolution detail MR urograms and in projection imaging.

Comparison of three-dimensional particle tracking and sizing using plenoptic imaging and digital in-line holography.

PubMed

Hall, Elise M; Thurow, Brian S; Guildenbecher, Daniel R

2016-08-10

Digital in-line holography (DIH) and plenoptic photography are two techniques for single-shot, volumetric measurement of 3D particle fields. Here we present a comparison of the two methods by applying plenoptic imaging to experimental configurations that have been previously investigated with DIH. These experiments include the tracking of secondary droplets from the impact of a water drop on a thin film of water and tracking of pellets from a shotgun. Both plenoptic imaging and DIH successfully quantify the 3D nature of these particle fields. This includes measurement of the 3D particle position, individual particle sizes, and three-component velocity vectors. For the initial processing methods presented here, both techniques give out-of-plane positional accuracy of approximately 1-2 particle diameters. For a fixed image sensor, digital holography achieves higher effective in-plane spatial resolutions. However, collimated and coherent illumination makes holography susceptible to image distortion through index of refraction gradients, as demonstrated in the shotgun experiments. In contrast, plenoptic imaging allows for a simpler experimental configuration and, due to the use of diffuse, white-light illumination, plenoptic imaging is less susceptible to image distortion in the shotgun experiments.

Via Method for Lithography Free Contact and Preservation of 2D Materials.

PubMed

Telford, Evan J; Benyamini, Avishai; Rhodes, Daniel; Wang, Da; Jung, Younghun; Zangiabadi, Amirali; Watanabe, Kenji; Taniguchi, Takashi; Jia, Shuang; Barmak, Katayun; Pasupathy, Abhay N; Dean, Cory R; Hone, James

2018-02-14

Atomically thin 2D materials span the common components of electronic circuits as metals, semiconductors, and insulators, and can manifest correlated phases such as superconductivity, charge density waves, and magnetism. An ongoing challenge in the field is to incorporate these 2D materials into multilayer heterostructures with robust electrical contacts while preventing disorder and degradation. In particular, preserving and studying air-sensitive 2D materials has presented a significant challenge since they readily oxidize under atmospheric conditions. We report a new technique for contacting 2D materials, in which metal via contacts are integrated into flakes of insulating hexagonal boron nitride, and then placed onto the desired conducting 2D layer, avoiding direct lithographic patterning onto the 2D conductor. The metal contacts are planar with the bottom surface of the boron nitride and form robust contacts to multiple 2D materials. These structures protect air-sensitive 2D materials for months with no degradation in performance. This via contact technique will provide the capability to produce "atomic printed circuit boards" that can form the basis of more complex multilayer heterostructures.

Cytotoxic deoxybenzoins and diphenylethylenes from Arundina graminifolia.

PubMed

Hu, Qiu-Fen; Zhou, Bin; Ye, Yan-Qing; Jiang, Zhi-Yong; Huang, Xiang-Zhong; Li, Yin-Ke; Du, Gang; Yang, Guang-Yu; Gao, Xue-Mei

2013-10-25

Eight new C-4-alkylated deoxybenzoins (1-8), three new diphenylethylenes (9-11), and five known diphenylethylenes were isolated from Arundina graminifolia. The structures of 1-11 were elucidated by spectroscopic methods including extensive 1D and 2D NMR techniques. Compounds 9-11 are the first naturally occurring diphenylethylenes possessing a hydroxyethyl unit. Compounds 1-11 were evaluated for cytotoxicity against five human tumor cell lines. Compounds 4, 5, and 9-11 showed significant cytotoxicity against five cancer cell lines, with IC50 values ranging from 1.8 to 8.7 μM.

Robot-assisted, single-site, dismembered pyeloplasty for ureteropelvic junction obstruction with the new da Vinci platform: a stage 2a study.

PubMed

Buffi, Nicolò Maria; Lughezzani, Giovanni; Fossati, Nicola; Lazzeri, Massimo; Guazzoni, Giorgio; Lista, Giuliana; Larcher, Alessandro; Abrate, Alberto; Fiori, Cristian; Cestari, Andrea; Porpiglia, Francesco

2015-01-01

Laparoendoscopic single-site surgery (LESS) has gained popularity in urology over the last few years. To report a stage 2a study of robot-assisted single-site (R-LESS) pyeloplasty for ureteropelvic junction obstruction (UPJO). This study is an investigative pilot study of 30 consecutive cases of R-LESS pyeloplasty performed at two participating institutions between July 2011 and September 2013. Dismembered R-LESS pyeloplasty was performed at two surgical centers. Feasibility (conversion rate), safety (complication rate and Clavien-Dindo classification), efficacy (clinical outcome) of the procedure were assessed. The median patient age was 37 yr (range: 19-65 yr) and median body mass index was 23 kg/m(2) (range: 19-29 kg/m(2)). The median operative time was 160 min (range: 101-300 min), the median postoperative stay was 5 d (range: 3-13 d), and the median time to catheter removal was 3 d (range: 2-10). Two cases required conversion, the first one to standard laparoscopic technique and the second one to standard robotic technique. No intraoperative complications were reported. In three cases, an additional 5-mm trocar was needed. The postoperative complications rate was 26% (n=8). Most of them were grade 1 complications (n=4; 13%), followed by grade 2 (n=3; 10%) and grade 3 (n=1; 3.3%) complications, according to the Clavien-Dindo classification. One patient needed a surgical reintervention with standard robotic technique 3 d after surgery for urinary leakage. The overall success rate, considered as the resolution of symptoms and the absence of functional impairment at postoperative imaging, was 93.3% (n=28) at a median follow-up of 13 mo (range: 3-21 mo). The main limitations of this study are the limited number of patients included and the short-term follow-up. Single-site robotic pyeloplasty is a feasible technique in selected patients, with good cosmetic results and excellent short-term clinical outcomes. Prospective studies are needed to further assess its role for the treatment of UPJO. Single-site robot-assisted pyeloplasty is a feasible technique with good cosmetic results and excellent short-term clinical outcomes. Copyright © 2014. Published by Elsevier B.V.

3D temporal subtraction on multislice CT images using nonlinear warping technique

NASA Astrophysics Data System (ADS)

Ishida, Takayuki; Katsuragawa, Shigehiko; Kawashita, Ikuo; Kim, Hyounseop; Itai, Yoshinori; Awai, Kazuo; Li, Qiang; Doi, Kunio

2007-03-01

The detection of very subtle lesions and/or lesions overlapped with vessels on CT images is a time consuming and difficult task for radiologists. In this study, we have developed a 3D temporal subtraction method to enhance interval changes between previous and current multislice CT images based on a nonlinear image warping technique. Our method provides a subtraction CT image which is obtained by subtraction of a previous CT image from a current CT image. Reduction of misregistration artifacts is important in the temporal subtraction method. Therefore, our computerized method includes global and local image matching techniques for accurate registration of current and previous CT images. For global image matching, we selected the corresponding previous section image for each current section image by using 2D cross-correlation between a blurred low-resolution current CT image and a blurred previous CT image. For local image matching, we applied the 3D template matching technique with translation and rotation of volumes of interests (VOIs) which were selected in the current and the previous CT images. The local shift vector for each VOI pair was determined when the cross-correlation value became the maximum in the 3D template matching. The local shift vectors at all voxels were determined by interpolation of shift vectors of VOIs, and then the previous CT image was nonlinearly warped according to the shift vector for each voxel. Finally, the warped previous CT image was subtracted from the current CT image. The 3D temporal subtraction method was applied to 19 clinical cases. The normal background structures such as vessels, ribs, and heart were removed without large misregistration artifacts. Thus, interval changes due to lung diseases were clearly enhanced as white shadows on subtraction CT images.

Multiview 3D sensing and analysis for high quality point cloud reconstruction

NASA Astrophysics Data System (ADS)

Satnik, Andrej; Izquierdo, Ebroul; Orjesek, Richard

2018-04-01

Multiview 3D reconstruction techniques enable digital reconstruction of 3D objects from the real world by fusing different viewpoints of the same object into a single 3D representation. This process is by no means trivial and the acquisition of high quality point cloud representations of dynamic 3D objects is still an open problem. In this paper, an approach for high fidelity 3D point cloud generation using low cost 3D sensing hardware is presented. The proposed approach runs in an efficient low-cost hardware setting based on several Kinect v2 scanners connected to a single PC. It performs autocalibration and runs in real-time exploiting an efficient composition of several filtering methods including Radius Outlier Removal (ROR), Weighted Median filter (WM) and Weighted Inter-Frame Average filtering (WIFA). The performance of the proposed method has been demonstrated through efficient acquisition of dense 3D point clouds of moving objects.

Investigating Gravity Waves in Polar Mesospheric Clouds Using Tomographic Reconstructions of AIM Satellite Imagery

NASA Astrophysics Data System (ADS)

Hart, V. P.; Taylor, M. J.; Doyle, T. E.; Zhao, Y.; Pautet, P.-D.; Carruth, B. L.; Rusch, D. W.; Russell, J. M.

2018-01-01

This research presents the first application of tomographic techniques for investigating gravity wave structures in polar mesospheric clouds (PMCs) imaged by the Cloud Imaging and Particle Size instrument on the NASA AIM satellite. Albedo data comprising consecutive PMC scenes were used to tomographically reconstruct a 3-D layer using the Partially Constrained Algebraic Reconstruction Technique algorithm and a previously developed "fanning" technique. For this pilot study, a large region (760 × 148 km) of the PMC layer (altitude 83 km) was sampled with a 2 km horizontal resolution, and an intensity weighted centroid technique was developed to create novel 2-D surface maps, characterizing the individual gravity waves as well as their altitude variability. Spectral analysis of seven selected wave events observed during the Northern Hemisphere 2007 PMC season exhibited dominant horizontal wavelengths of 60-90 km, consistent with previous studies. These tomographic analyses have enabled a broad range of new investigations. For example, a clear spatial anticorrelation was observed between the PMC albedo and wave-induced altitude changes, with higher-albedo structures aligning well with wave troughs, while low-intensity regions aligned with wave crests. This result appears to be consistent with current theories of PMC development in the mesopause region. This new tomographic imaging technique also provides valuable wave amplitude information enabling further mesospheric gravity wave investigations, including quantitative analysis of their hemispheric and interannual characteristics and variations.

A methodology for the generation of the 2-D map from unknown navigation environment by traveling a short distance

NASA Technical Reports Server (NTRS)

Bourbakis, N.; Sarkar, D.

1994-01-01

A technique for generation of a 2-D space map by traveling a short distance is described. The space to be mapped can be classified as: (1) space without obstacles, (2) space with stationary obstacles, and (3) space with moving obstacles. This paper presents the methodology used to generate a 2-D map of an unknown navigation space. The ability to minimize the redundancy during traveling and maximize the confidence function for generation of the map are advantages of this technique.

Pop-up assembly of 3D structures actuated by heat shrinkable polymers

NASA Astrophysics Data System (ADS)

Cui, Jianxun; Adams, J. G. M.; Zhu, Yong

2017-12-01

Folding 2D sheets into desired 3D structures is a promising fabrication technique that can find a wide range of applications. Compressive buckling provides an attractive strategy to actuate the folding and can be applied to a broad range of materials. Here a new and simple method is reported to achieve controlled compressive buckling, which is actuated by a heat shrinkable polymer sheet. The buckling deformation is localized at the pre-defined creases in the 2D sheet, resulting in sharp folding. Two approaches are developed to actuate the transformation, which follow similar geometric rules. In the first approach, the 2D precursor is pushed from outside, which leads to a 3D structure surrounded by the shrunk polymer sheet. Assembled 3D structures include prisms/pyramids with different base shapes, house roof, partial soccer ball, Miura-ori structure and insect wing. In the second approach, the 2D precursor is pulled from inside, which leads to a 3D structure enclosing the shrunk polymer sheet. Prisms/pyramids with different base shapes are assembled. The assembled structures are further tessellated to fabricate cellular structures that can be used as thermal insulator and crash energy absorber. They are also stacked vertically to fabricate complex multilayer structures.

Emerging Applications of Bedside 3D Printing in Plastic Surgery

PubMed Central

Chae, Michael P.; Rozen, Warren M.; McMenamin, Paul G.; Findlay, Michael W.; Spychal, Robert T.; Hunter-Smith, David J.

2015-01-01

Modern imaging techniques are an essential component of preoperative planning in plastic and reconstructive surgery. However, conventional modalities, including three-dimensional (3D) reconstructions, are limited by their representation on 2D workstations. 3D printing, also known as rapid prototyping or additive manufacturing, was once the province of industry to fabricate models from a computer-aided design (CAD) in a layer-by-layer manner. The early adopters in clinical practice have embraced the medical imaging-guided 3D-printed biomodels for their ability to provide tactile feedback and a superior appreciation of visuospatial relationship between anatomical structures. With increasing accessibility, investigators are able to convert standard imaging data into a CAD file using various 3D reconstruction softwares and ultimately fabricate 3D models using 3D printing techniques, such as stereolithography, multijet modeling, selective laser sintering, binder jet technique, and fused deposition modeling. However, many clinicians have questioned whether the cost-to-benefit ratio justifies its ongoing use. The cost and size of 3D printers have rapidly decreased over the past decade in parallel with the expiration of key 3D printing patents. Significant improvements in clinical imaging and user-friendly 3D software have permitted computer-aided 3D modeling of anatomical structures and implants without outsourcing in many cases. These developments offer immense potential for the application of 3D printing at the bedside for a variety of clinical applications. In this review, existing uses of 3D printing in plastic surgery practice spanning the spectrum from templates for facial transplantation surgery through to the formation of bespoke craniofacial implants to optimize post-operative esthetics are described. Furthermore, we discuss the potential of 3D printing to become an essential office-based tool in plastic surgery to assist in preoperative planning, developing intraoperative guidance tools, teaching patients and surgical trainees, and producing patient-specific prosthetics in everyday surgical practice. PMID:26137465

Emerging Applications of Bedside 3D Printing in Plastic Surgery.

PubMed

Chae, Michael P; Rozen, Warren M; McMenamin, Paul G; Findlay, Michael W; Spychal, Robert T; Hunter-Smith, David J

2015-01-01

Modern imaging techniques are an essential component of preoperative planning in plastic and reconstructive surgery. However, conventional modalities, including three-dimensional (3D) reconstructions, are limited by their representation on 2D workstations. 3D printing, also known as rapid prototyping or additive manufacturing, was once the province of industry to fabricate models from a computer-aided design (CAD) in a layer-by-layer manner. The early adopters in clinical practice have embraced the medical imaging-guided 3D-printed biomodels for their ability to provide tactile feedback and a superior appreciation of visuospatial relationship between anatomical structures. With increasing accessibility, investigators are able to convert standard imaging data into a CAD file using various 3D reconstruction softwares and ultimately fabricate 3D models using 3D printing techniques, such as stereolithography, multijet modeling, selective laser sintering, binder jet technique, and fused deposition modeling. However, many clinicians have questioned whether the cost-to-benefit ratio justifies its ongoing use. The cost and size of 3D printers have rapidly decreased over the past decade in parallel with the expiration of key 3D printing patents. Significant improvements in clinical imaging and user-friendly 3D software have permitted computer-aided 3D modeling of anatomical structures and implants without outsourcing in many cases. These developments offer immense potential for the application of 3D printing at the bedside for a variety of clinical applications. In this review, existing uses of 3D printing in plastic surgery practice spanning the spectrum from templates for facial transplantation surgery through to the formation of bespoke craniofacial implants to optimize post-operative esthetics are described. Furthermore, we discuss the potential of 3D printing to become an essential office-based tool in plastic surgery to assist in preoperative planning, developing intraoperative guidance tools, teaching patients and surgical trainees, and producing patient-specific prosthetics in everyday surgical practice.

2,4-Dichlorophenoxyacetic acid (2,4-D) degradation promoted by nanoparticulate zerovalent iron (nZVI) in aerobic suspensions.

PubMed

Correia de Velosa, Adriana; Pupo Nogueira, Raquel F

2013-05-30

Reactive species generated by Fe(0) oxidation promoted by O2 (catalyzed or not by ligands) are able to degrade contaminant compounds like the herbicide 2,4-dichlorophenoxyacetic acid. The degradation of 2,4-D was influenced by the concentrations of zero valent iron (ZVI) and different ligands, as well as by pH. In the absence of ligands, the highest 2,4-D degradation rate was obtained at pH 3, while the highest percentage degradation (50%) was achieved at pH 5 after 120 min of reaction. Among the ligands studied (DTPA, EDTA, glycine, oxalate, and citrate), only ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA) significantly enhanced oxidation of 2,4-D. This increase in oxidation was observed at all pH values tested (including neutral to alkaline conditions), indicating the feasibility of the technique for treatment of contaminated water. In the presence of EDTA, the oxidation rate was greater at pH 3 than at pH 5 or 7. Increasing the EDTA concentration increased the rate and percentage of 2,4-D degradation, however increasing the Fe(0) concentration resulted in the opposite behavior. It was found that degradation of EDTA and 2,4-D occurred simultaneously, and that the new methodology avoided any 2,4-D removal by adsorption/coprecipitation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Preprocessing of 2-Dimensional Gel Electrophoresis Images Applied to Proteomic Analysis: A Review.

PubMed

Goez, Manuel Mauricio; Torres-Madroñero, Maria Constanza; Röthlisberger, Sarah; Delgado-Trejos, Edilson

2018-02-01

Various methods and specialized software programs are available for processing two-dimensional gel electrophoresis (2-DGE) images. However, due to the anomalies present in these images, a reliable, automated, and highly reproducible system for 2-DGE image analysis has still not been achieved. The most common anomalies found in 2-DGE images include vertical and horizontal streaking, fuzzy spots, and background noise, which greatly complicate computational analysis. In this paper, we review the preprocessing techniques applied to 2-DGE images for noise reduction, intensity normalization, and background correction. We also present a quantitative comparison of non-linear filtering techniques applied to synthetic gel images, through analyzing the performance of the filters under specific conditions. Synthetic proteins were modeled into a two-dimensional Gaussian distribution with adjustable parameters for changing the size, intensity, and degradation. Three types of noise were added to the images: Gaussian, Rayleigh, and exponential, with signal-to-noise ratios (SNRs) ranging 8-20 decibels (dB). We compared the performance of wavelet, contourlet, total variation (TV), and wavelet-total variation (WTTV) techniques using parameters SNR and spot efficiency. In terms of spot efficiency, contourlet and TV were more sensitive to noise than wavelet and WTTV. Wavelet worked the best for images with SNR ranging 10-20 dB, whereas WTTV performed better with high noise levels. Wavelet also presented the best performance with any level of Gaussian noise and low levels (20-14 dB) of Rayleigh and exponential noise in terms of SNR. Finally, the performance of the non-linear filtering techniques was evaluated using a real 2-DGE image with previously identified proteins marked. Wavelet achieved the best detection rate for the real image. Copyright © 2018 Beijing Institute of Genomics, Chinese Academy of Sciences and Genetics Society of China. Production and hosting by Elsevier B.V. All rights reserved.

Integrality and separability of multitouch interaction techniques in 3D manipulation tasks.

PubMed

Martinet, Anthony; Casiez, Géry; Grisoni, Laurent

2012-03-01

Multitouch displays represent a promising technology for the display and manipulation of data. While the manipulation of 2D data has been widely explored, 3D manipulation with multitouch displays remains largely unexplored. Based on an analysis of the integration and separation of degrees of freedom, we propose a taxonomy for 3D manipulation techniques with multitouch displays. Using that taxonomy, we introduce Depth-Separated Screen-Space (DS3), a new 3D manipulation technique based on the separation of translation and rotation. In a controlled experiment, we compared DS3 with Sticky Tools and Screen-Space. Results show that separating the control of translation and rotation significantly affects performance for 3D manipulation, with DS3 performing faster than the two other techniques.

Evaluation of the Chondromalacia Patella Using a Microscopy Coil: Comparison of the Two-Dimensional Fast Spin Echo Techniques and the Three-Dimensional Fast Field Echo Techniques

PubMed Central

Kim, Hyun-joo; Kang, Chang Ho; Ryu, Jeong Ah; Shin, Myung Jin; Cho, Kyung-Ja; Cho, Woo Shin

2011-01-01

Objective We wanted to compare the two-dimensional (2D) fast spin echo (FSE) techniques and the three-dimensional (3D) fast field echo techniques for the evaluation of the chondromalacia patella using a microscopy coil. Materials and Methods Twenty five patients who underwent total knee arthroplasty were included in this study. Preoperative MRI evaluation of the patella was performed using a microscopy coil (47 mm). The proton density-weighted fast spin echo images (PD), the fat-suppressed PD images (FS-PD), the intermediate weighted-fat suppressed fast spin echo images (iw-FS-FSE), the 3D balanced-fast field echo images (B-FFE), the 3D water selective cartilage scan (WATS-c) and the 3D water selective fluid scan (WATS-f) were obtained on a 1.5T MRI scanner. The patellar cartilage was evaluated in nine areas: the superior, middle and the inferior portions that were subdivided into the medial, central and lateral facets in a total of 215 areas. Employing the Noyes grading system, the MRI grade 0-I, II and III lesions were compared using the gross and microscopic findings. The sensitivity, specificity and accuracy were evaluated for each sequence. The significance of the differences for the individual sequences was calculated using the McNemar test. Results The gross and microscopic findings demonstrated 167 grade 0-I lesions, 40 grade II lesions and eight grade III lesions. Iw-FS-FSE had the highest accuracy (sensitivity/specificity/accuracy = 88%/98%/96%), followed by FS-PD (78%/98%/93%, respectively), PD (76%/98%/93%, respectively), B-FFE (71%/100%/93%, respectively), WATS-c (67%/100%/92%, respectively) and WATS-f (58%/99%/89%, respectively). There were statistically significant differences for the iw-FS-FSE and WATS-f and for the PD-FS and WATS-f (p < 0.01). Conclusion The iw-FS-FSE images obtained with a microscopy coil show best diagnostic performance among the 2D and 3D GRE images for evaluating the chondromalacia patella. PMID:21228943

Evaluation of the chondromalacia patella using a microscopy coil: comparison of the two-dimensional fast spin echo techniques and the three-dimensional fast field echo techniques.

PubMed

Kim, Hyun-joo; Lee, Sang Hoon; Kang, Chang Ho; Ryu, Jeong Ah; Shin, Myung Jin; Cho, Kyung-Ja; Cho, Woo Shin

2011-01-01

We wanted to compare the two-dimensional (2D) fast spin echo (FSE) techniques and the three-dimensional (3D) fast field echo techniques for the evaluation of the chondromalacia patella using a microscopy coil. Twenty five patients who underwent total knee arthroplasty were included in this study. Preoperative MRI evaluation of the patella was performed using a microscopy coil (47 mm). The proton density-weighted fast spin echo images (PD), the fat-suppressed PD images (FS-PD), the intermediate weighted-fat suppressed fast spin echo images (iw-FS-FSE), the 3D balanced-fast field echo images (B-FFE), the 3D water selective cartilage scan (WATS-c) and the 3D water selective fluid scan (WATS-f) were obtained on a 1.5T MRI scanner. The patellar cartilage was evaluated in nine areas: the superior, middle and the inferior portions that were subdivided into the medial, central and lateral facets in a total of 215 areas. Employing the Noyes grading system, the MRI grade 0-I, II and III lesions were compared using the gross and microscopic findings. The sensitivity, specificity and accuracy were evaluated for each sequence. The significance of the differences for the individual sequences was calculated using the McNemar test. The gross and microscopic findings demonstrated 167 grade 0-I lesions, 40 grade II lesions and eight grade III lesions. Iw-FS-FSE had the highest accuracy (sensitivity/specificity/accuracy = 88%/98%/96%), followed by FS-PD (78%/98%/93%, respectively), PD (76%/98%/93%, respectively), B-FFE (71%/100%/93%, respectively), WATS-c (67%/100%/92%, respectively) and WATS-f (58%/99%/89%, respectively). There were statistically significant differences for the iw-FS-FSE and WATS-f and for the PD-FS and WATS-f (p < 0.01). The iw-FS-FSE images obtained with a microscopy coil show best diagnostic performance among the 2D and 3D GRE images for evaluating the chondromalacia patella.

The structure of the exopolysaccharide of Pseudomonas fluorescens strain H13.

PubMed

Osman, S F; Fett, W F; Irwin, P; Cescutti, P; Brouillette, J N; O'Connor, J V

1997-05-19

An acidic exopolysaccharide was isolated from P. fluorescens strain H13. The structure of the polysaccharide repeating unit was determined using chemical methods and 1D and 2D NMR techniques. The repeating unit was characterized as a trisaccharide composed of D-glucose, 2-acetamido-2-deoxy-D-glucose and 4-O-acetyl-2-acetamido-2-deoxy-D-mannuronic acid.

[Combined use of wide-detector and adaptive statistical iterative reconstruction-V technique in abdominal CT with low radiation dose].

PubMed

Wang, H X; Lü, P J; Yue, S W; Chang, L Y; Li, Y; Zhao, H P; Li, W R; Gao, J B

2017-12-05

Objective: To investigate the image quality and radiation dose with wide-detector(80 mm) and adaptive statistical iterative reconstruction-V (ASIR-V) technique at abdominal contrast enhanced CT scan. Methods: In the first phantom experiment part, the percentage of ASIR-V for half dose of combined wide detector with ASIR-V technique as compared with standard-detector (40 mm) technique was determined. The human experiment was performed based on the phantom study, 160 patients underwent contrast-enhanced abdominal CT scan were prospectively collected and divided into the control group ( n =40) with image reconstruction using 40% ASIR (group A) and the study group ( n =120) with random number table. According to pre-ASIR-V percentage, the study group was assigned into three groups[40 cases in each group, group B: 0 pre-ASIR-V scan with image reconstruction of 0-100% post-ASIR-V (interval 10%, subgroups B0-B10); group C: 20% pre-ASIR-V with 20%, 40% and 60% post-ASIR-V (subgroups C1-C3); group D: 40%pre-ASIR-V with 40% and 60% post-ASIR-V (subgroups D1-D2)]. Image noise, CT attenuation values and CNR of the liver, pancreas, aorta and portal vein were compared by using two sample t test and One-way ANOVA. Qualitative visual parameters (overall image quality as graded on a 5-point scale) was compared by Mann-Whitney U test and Kruskal-Wallis H test. Results: The phantom experiment showed that the percentage of pre-ASIR-V for half dose was 40%. With the 40% pre-ASIR-V, radiation dose in the study group was reduced by 35.5% as compared with the control group. Image noise in the subgroups of B2-B10, C2-C3 and D1-D2 were lower ( t =-14.681--3.046, all P <0.05) while CNR in the subgroups of B4-B10, C2-3 and D1-D2 were higher( t =2.048-9.248, all P <0.05)than those in group A, except the CNR of liver in the arterial phase (AP) in C2, D1 and D2 and the CNR of pancreas in AP in D1 ( t =0.574-1.327, all P >0.05). The subjective image quality scores increased gradually in the range of 0-60% post-ASIR-V and decreased with post-ASIR-V larger than 70%. The overall image quality of subgroup B3-B8, C2-C3 and D1-D2 were higher than that in group A ( Z =-2.229--6.533, all P <0.05). Conclusion: Compared with stand-detector together with ASIR technique, wide-detector combined with 40% pre-ASIR-V technique with 60% post-ASIR-V image reconstruction can reduce radiation dose while maintain good overall image quality.

Comparison of Bispectral Index™ values during the flotation restricted environmental stimulation technique and results for stage I sleep: a prospective pilot investigation.

PubMed

Dunham, C Michael; McClain, Jesse V; Burger, Amanda

2017-11-29

To determine whether Bispectral Index™ values obtained during flotation-restricted environment stimulation technique have a similar profile in a single observation compared to literature-derived results found during sleep and other relaxation-induction interventions. Bispectral Index™ values were as follows: awake-state, 96.6; float session-1, 84.3; float session-2, 82.3; relaxation-induction, 82.8; stage I sleep, 86.0; stage II sleep, 66.2; and stages III-IV sleep, 45.1. Awake-state values differed from float session-1 (%difference 12.7%; Cohen's d = 3.6) and float session-2 (%difference 14.8%; Cohen's d = 4.6). Relaxation-induction values were similar to float session-1 (%difference 1.8%; Cohen's d = 0.3) and float session-2 (%difference 0.5%; Cohen's d = 0.1). Stage I sleep values were similar to float session-1 (%difference 1.9%; Cohen's d = 0.4) and float session-2 (%difference 4.3%; Cohen's d = 1.0). Stage II sleep values differed from float session-1 (%difference 21.5%; Cohen's d = 4.3) and float session-2 (%difference 19.6%; Cohen's d = 4.0). Stages III-IV sleep values differed from float session-1 (%difference 46.5%; Cohen's d = 5.6) and float session-2 (%difference 45.2%; Cohen's d = 5.4). Bispectral Index™ values during flotation were comparable to those found in stage I sleep and nadir values described with other relaxation-induction techniques.

Electron Tomography: A Three-Dimensional Analytic Tool for Hard and Soft Materials Research

DOE PAGES

Ercius, Peter; Alaidi, Osama; Rames, Matthew J.; ...

2015-06-18

Three-dimensional (3D) structural analysis is essential to understand the relationship between the structure and function of an object. Many analytical techniques, such as X-ray diffraction, neutron spectroscopy, and electron microscopy imaging, are used to provide structural information. Transmission electron microscopy (TEM), one of the most popular analytic tools, has been widely used for structural analysis in both physical and biological sciences for many decades, in which 3D objects are projected into two-dimensional (2D) images. In many cases, 2D-projection images are insufficient to understand the relationship between the 3D structure and the function of nanoscale objects. Electron tomography (ET) is amore » technique that retrieves 3D structural information from a tilt series of 2D projections, and is gradually becoming a mature technology with sub-nanometer resolution. Distinct methods to overcome sample-based limitations have been separately developed in both physical and biological science, although they share some basic concepts of ET. Here, this review discusses the common basis for 3D characterization, and specifies difficulties and solutions regarding both hard and soft materials research. It is hoped that novel solutions based on current state-of-the-art techniques for advanced applications in hybrid matter systems can be motivated. Electron tomography produces quantitative 3D reconstructions for biological and physical sciences from sets of 2D projections acquired at different tilting angles in a transmission electron microscope. Finally, state-of-the-art techniques capable of producing 3D representations such as Pt-Pd core-shell nanoparticles and IgG1 antibody molecules are reviewed.« less

Technique and Preliminary Analysis of Drug-Induced Sleep Endoscopy With Online Polygraphic Cardiorespiratory Monitoring in Patients With Obstructive Sleep Apnea Syndrome

PubMed Central

Gobbi, Riccardo; Mondini, Susanna; Cerritelli, Luca; Piccin, Ottavio; Scaramuzzino, Giuseppe; Milano, Francesca; Melotti, Maria Rita; Mordini, Francesco; Pirodda, Antonio; Cirignotta, Fabio; Sorrenti, Giovanni

2017-01-01

Importance Drug-induced sleep endoscopy is a diagnostic technique that allows dynamic evaluation of the upper airway during artificial sleep. The lack of a standardized procedure and the difficulties associated with direct visual detection of obstructive events result in poor intraobserver and interobserver reliability, especially when otolaryngology surgeons not experienced in the technique are involved. Objectives To describe a drug-induced sleep endoscopy technique implemented with simultaneous polygraphic monitoring of cardiorespiratory parameters (DISE-PG) in patients with a diagnosis of obstructive sleep apnea syndrome and discuss the technique’s possible advantages compared with the standard procedure. Design, Setting, and Participants This prospective cohort study included 50 consecutive patients with obstructive sleep apnea syndrome who underwent DISE-PG from March 1, 2013, to June 30, 2014. A standard protocol was adopted, and all the procedures were carried out in an operation room by an experienced otolaryngology surgeon under the supervision of an anesthesiologist. Endoscopic and polygraphic obstructive respiratory events were analyzed offline in a double-blind setting and randomized order. Main Outcomes and Measures The feasibility and safety of the DISE-PG technique, as well as its sensitivity in detecting respiratory events compared with that of the standard drug-induced sleep endoscopy procedure. Results All 50 patients (43 men and 7 women; mean [SD] age, 51.1 [12.1] years) underwent DISE-PG without technical problems or patient difficulties regarding the procedure. As expected, polygraphic scoring was more sensitive than endoscopic scoring in identifying obstructive events (mean [SD] total events, 13.3 [6.8] vs 5.3 [3.6]; mean [SD] difference, 8.8 [5.6]; 95% CI, 7.3 to 10.4; Cohen d, –1.5). This difference was most pronounced in patients with a higher apnea-hypopnea index (AHI) at baseline (mean [SD] difference for AHI >30, 27.1% [31.0%]; 95% CI, –36.2% to 90.4%; Cohen d, 0.2; for AH I >40, 76.0% [35.5%]; 95% CI, 4.6% to 147.4%; Cohen d, 0.5; for AHI >50, 92.2% [37.2%]; 95% CI, 17.3% to 167.1%; Cohen d, 0.6) and a high percentage of hypopneas (≥75% of all obstructive events) at baseline (mean [SD] difference, 20.2% [5.4%]; 95% CI, 9.2% to 31.3%; Cohen d, 1.1). No other anthropomorphic or polygraphic features at baseline were associated with the differences between the DISE-PG and baseline home sleep apnea test. Conclusions and Relevance The DISE-PG technique is feasible, safe, and more sensitive at detecting an obstructed breathing pattern than is drug-induced sleep endoscopy alone. The DISE-PG technique could be helpful for accurate comprehension of upper airway obstructive dynamics (ie, degree of obstruction and multilevel pattern) and a nonobstructive breathing pattern (ie, central apneas). PMID:28253389

Dione's resurfacing history as determined from a global impact crater database

NASA Astrophysics Data System (ADS)

Kirchoff, Michelle R.; Schenk, Paul

2015-08-01

Saturn's moon Dione has an interesting and unique resurfacing history recorded by the impact craters on its surface. In order to further resolve this history, we compile a crater database that is nearly global for diameters (D) equal to and larger than 4 km using standard techniques and Cassini Imaging Science Subsystem images. From this database, spatial crater density maps for different diameter ranges are generated. These maps, along with the observed surface morphology, have been used to define seven terrain units for Dione, including refinement of the smooth and "wispy" (or faulted) units from Voyager observations. Analysis of the terrains' crater size-frequency distributions (SFDs) indicates that: (1) removal of D ≈ 4-50 km craters in the "wispy" terrain was most likely by the formation of D ≳ 50 km craters, not faulting, and likely occurred over a couple billion of years; (2) resurfacing of the smooth plains was most likely by cryovolcanism at ∼2 Ga; (3) most of Dione's largest craters (D ⩾ 100 km), including Evander (D = 350 km), may have formed quite recently (<2 Ga), but are still relaxed, indicating Dione has been thermally active for at least half its history; and (4) the variation in crater SFDs at D ≈ 4-15 km is plausibly due to different levels of minor resurfacing (mostly subsequent large impacts) within each terrain.

PSYCHE Pure Shift NMR Spectroscopy.

PubMed

Foroozandeh, Mohammadali; Morris, Gareth; Nilsson, Mathias

2018-03-13

Broadband homodecoupling techniques in NMR, also known as "pure shift" methods, aim to enhance spectral resolution by suppressing the effects of homonuclear coupling interactions to turn multiplet signals into singlets. Such techniques typically work by selecting a subset of "active" nuclear spins to observe, and selectively inverting the remaining, "passive", spins to reverse the effects of coupling. Pure Shift Yielded by Chirp Excitation (PSYCHE) is one such method; it is relatively recent, but has already been successfully implemented in a range of different NMR experiments. Paradoxically, PSYCHE is one of the trickiest of pure shift NMR techniques to understand but one of the easiest to use. Here we offer some insights into theoretical and practical aspects of the method, and into the effects and importance of the experimental parameters. Some recent improvements that enhance the spectral purity of PSYCHE spectra will be presented, and some experimental frameworks including examples in 1D and 2D NMR spectroscopy, for the implementation of PSYCHE will be introduced. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biogas upgrading: optimal activated carbon properties for siloxane removal.

PubMed

Cabrera-Codony, Alba; Montes-Morán, Miguel A; Sánchez-Polo, Manuel; Martín, Maria J; Gonzalez-Olmos, Rafael

2014-06-17

A total of 12 commercial activated carbons (ACs) have been tested for the removal of octamethylcyclotetrasiloxane (D4) in dynamic adsorption experiments using different carrier gases and D4 concentrations. Characterization of the ACs included several physical and chemical techniques. The D4 adsorption capacities were strongly related with the textural development of the ACs. Results showed that the optimum adsorbent for D4 is a wood-based chemically activated carbon, which rendered an adsorption capacity of 1732 ± 93 mg g(-1) using 1000 ppm (v/v) of D4 with dry N2 as the carrier gas. When the concentration of D4 was lowered to typical values found in biogas, the adsorption capacity was halved. The presence of major biogas compounds (i.e., CH4 and CO2) and humidity further reduced the D4 adsorption capacity. The polymerization of D4 over the surface of all ACs was found to be relevant after prolonged contact times. The extent of this phenomenon, which may negatively affect the thermal regeneration of the AC, correlated reasonably well with the presence of phenolic and carboxylic groups on the carbon surfaces.

Effects of implant system, impression technique, and impression material on accuracy of the working cast.

PubMed

Wegner, Kerstin; Weskott, Katharina; Zenginel, Martha; Rehmann, Peter; Wöstmann, Bernd

2013-01-01

This in vitro study aimed to identify the effects of the implant system, impression technique, and impression material on the transfer accuracy of implant impressions. The null hypothesis tested was that, in vitro and within the parameters of the experiment, the spatial relationship of a working cast to the placement of implants is not related to (1) the implant system, (2) the impression technique, or (3) the impression material. A steel maxilla was used as a reference model. Six implants of two different implant systems (Standard Plus, Straumann; Semados, Bego) were fixed in the reference model. The target variables were: three-dimensional (3D) shift in all directions, implant axis direction, and rotation. The target variables were assessed using a 3D coordinate measuring machine, and the respective deviations of the plaster models from the nominal values of the reference model were calculated. Two different impression techniques (reposition/pickup) and four impression materials (Aquasil Ultra, Flexitime, Impregum Penta, P2 Magnum 360) were investigated. In all, 80 implant impressions for each implant system were taken. Statistical analysis was performed using multivariate analysis of variance. The implant system significantly influenced the transfer accuracy for most spatial dimensions, including the overall 3D shift and implant axis direction. There was no significant difference between the two implant systems with regard to rotation. Multivariate analysis of variance showed a significant effect on transfer accuracy only for the implant system. Within the limits of the present study, it can be concluded that the transfer accuracy of the intraoral implant position on the working cast is far more dependent on the implant system than on the selection of a specific impression technique or material.

Mathematical modeling of serum 13C-retinol in captive rhesus monkeys provides new insights on hypervitaminosis A.

PubMed

Escaron, Anne L; Green, Michael H; Howe, Julie A; Tanumihardjo, Sherry A

2009-10-01

Hypervitaminosis A is increasingly a public health concern, and thus noninvasive quantitative methods merit exploration. In this study, we applied the (13)C-retinol isotope dilution test to a nonhuman primate model with excessive liver stores. After baseline serum chemistries, rhesus macaques (Macaca mulatta; n = 16) were administered 3.5 mumol (13)C(2)-retinyl acetate. Blood was drawn at baseline, 5 h, and 2, 4, 7, 14, 21, and 28 d following the dose. Liver biopsies were collected 7 d before and 2 d after dosing (n = 4) and at 7, 14, and 28 d (n = 4/time) after dosing. Serum and liver were analyzed by HPLC and GC-combustion-isotope ratio MS for retinol and its enrichment, respectively. Model-based compartmental analysis was applied to serum data. Lactate dehydrogenase was elevated in 50% of the monkeys. Total body reserves (TBR) of vitamin A (VA) were calculated at 28 d. Predicted TBR (3.52 +/- 2.01 mmol VA) represented measured liver stores (4.56 +/- 1.38 mmol VA; P = 0.124). Predicted liver VA concentrations (13.3 +/- 9.7 micromol/g) were similar to measured liver VA concentrations (16.4 +/- 5.3 micromol/g). The kinetic models predict that 27-52% of extravascular VA is exchanging with serum in hypervitaminotic A monkeys. The test correctly diagnosed hypervitaminosis A in all monkeys, i.e. 100% sensitivity. Stable isotope techniques have important public health potential for the classification of VA status, including hypervitaminosis, because no other technique besides invasive liver biopsies, correctly identifies excessive liver VA stores.

The importance of atomic and molecular correlation on the bonding in transition metal compounds

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Walch, Stephen P.

1986-01-01

The determination of accurate spectroscopic parameters for molecular systems containing transition metal atoms is shown to require extensive data sets and a high level correlation treatment, and techniques and their limitations are considered. Extensive results reported on the transition metal atoms, hydrides, oxides, and dimers makes possible the design of a calculation to correctly describe the mixing of different atomic asymptotes, and to give a correct balance between molecular bonding and exchange interactions. Examples considered include the dipole moment of the 2Delta state of NiH, which can help determine the mixture of 3d(8)4s(2) and 3d(9)4s(1) in the NiH wavefunction, and the bonding in CrO, where an equivalent description of the relative energies associated with the Cr 3d-3d atomic exchange and the Cr-O bond is important.

Teaching Computational Geophysics Classes using Active Learning Techniques

NASA Astrophysics Data System (ADS)

Keers, H.; Rondenay, S.; Harlap, Y.; Nordmo, I.

2016-12-01

We give an overview of our experience in teaching two computational geophysics classes at the undergraduate level. In particular we describe The first class is for most students the first programming class and assumes that the students have had an introductory course in geophysics. In this class the students are introduced to basic Matlab skills: use of variables, basic array and matrix definition and manipulation, basic statistics, 1D integration, plotting of lines and surfaces, making of .m files and basic debugging techniques. All of these concepts are applied to elementary but important concepts in earthquake and exploration geophysics (including epicentre location, computation of travel time curves for simple layered media plotting of 1D and 2D velocity models etc.). It is important to integrate the geophysics with the programming concepts: we found that this enhances students' understanding. Moreover, as this is a 3 year Bachelor program, and this class is taught in the 2nd semester, there is little time for a class that focusses on only programming. In the second class, which is optional and can be taken in the 4th or 6th semester, but often is also taken by Master students we extend the Matlab programming to include signal processing and ordinary and partial differential equations, again with emphasis on geophysics (such as ray tracing and solving the acoustic wave equation). This class also contains a project in which the students have to write a brief paper on a topic in computational geophysics, preferably with programming examples. When teaching these classes it was found that active learning techniques, in which the students actively participate in the class, either individually, in pairs or in groups, are indispensable. We give a brief overview of the various activities that we have developed when teaching theses classes.

2D imaging and 3D sensing data acquisition and mutual registration for painting conservation

NASA Astrophysics Data System (ADS)

Fontana, Raffaella; Gambino, Maria Chiara; Greco, Marinella; Marras, Luciano; Pampaloni, Enrico M.; Pelagotti, Anna; Pezzati, Luca; Poggi, Pasquale

2004-12-01

We describe the application of 2D and 3D data acquisition and mutual registration to the conservation of paintings. RGB color image acquisition, IR and UV fluorescence imaging, together with the more recent hyperspectral imaging (32 bands) are among the most useful techniques in this field. They generally are meant to provide information on the painting materials, on the employed techniques and on the object state of conservation. However, only when the various images are perfectly registered on each other and on the 3D model, no ambiguity is possible and safe conclusions may be drawn. We present the integration of 2D and 3D measurements carried out on two different paintings: "Madonna of the Yarnwinder" by Leonardo da Vinci, and "Portrait of Lionello d'Este", by Pisanello, both painted in the XV century.

2D imaging and 3D sensing data acquisition and mutual registration for painting conservation

NASA Astrophysics Data System (ADS)

Fontana, Raffaella; Gambino, Maria Chiara; Greco, Marinella; Marras, Luciano; Pampaloni, Enrico M.; Pelagotti, Anna; Pezzati, Luca; Poggi, Pasquale

2005-01-01

We describe the application of 2D and 3D data acquisition and mutual registration to the conservation of paintings. RGB color image acquisition, IR and UV fluorescence imaging, together with the more recent hyperspectral imaging (32 bands) are among the most useful techniques in this field. They generally are meant to provide information on the painting materials, on the employed techniques and on the object state of conservation. However, only when the various images are perfectly registered on each other and on the 3D model, no ambiguity is possible and safe conclusions may be drawn. We present the integration of 2D and 3D measurements carried out on two different paintings: "Madonna of the Yarnwinder" by Leonardo da Vinci, and "Portrait of Lionello d'Este", by Pisanello, both painted in the XV century.

An optical tracking system for virtual reality

NASA Astrophysics Data System (ADS)

Hrimech, Hamid; Merienne, Frederic

2009-03-01

In this paper we present a low-cost 3D tracking system which we have developed and tested in order to move away from traditional 2D interaction techniques (keyboard and mouse) in an attempt to improve user's experience while using a CVE. Such a tracking system is used to implement 3D interaction techniques that augment user experience, promote user's sense of transportation in the virtual world as well as user's awareness of their partners. The tracking system is a passive optical tracking system using stereoscopy a technique allowing the reconstruction of three-dimensional information from a couple of images. We have currently deployed our 3D tracking system on a collaborative research platform for investigating 3D interaction techniques in CVEs.

Three-Dimensional Printing of Multifunctional Nanocomposites: Manufacturing Techniques and Applications.

PubMed

Farahani, Rouhollah D; Dubé, Martine; Therriault, Daniel

2016-07-01

The integration of nanotechnology into three-dimensional printing (3DP) offers huge potential and opportunities for the manufacturing of 3D engineered materials exhibiting optimized properties and multifunctionality. The literature relating to different 3DP techniques used to fabricate 3D structures at the macro- and microscale made of nanocomposite materials is reviewed here. The current state-of-the-art fabrication methods, their main characteristics (e.g., resolutions, advantages, limitations), the process parameters, and materials requirements are discussed. A comprehensive review is carried out on the use of metal- and carbon-based nanomaterials incorporated into polymers or hydrogels for the manufacturing of 3D structures, mostly at the microscale, using different 3D-printing techniques. Several methods, including but not limited to micro-stereolithography, extrusion-based direct-write technologies, inkjet-printing techniques, and popular powder-bed technology, are discussed. Various examples of 3D nanocomposite macro- and microstructures manufactured using different 3D-printing technologies for a wide range of domains such as microelectromechanical systems (MEMS), lab-on-a-chip, microfluidics, engineered materials and composites, microelectronics, tissue engineering, and biosystems are reviewed. Parallel advances on materials and techniques are still required in order to employ the full potential of 3D printing of multifunctional nanocomposites. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Micromachining Techniques in Developing High-Frequency Piezoelectric Composite Ultrasonic Array Transducers

PubMed Central

Liu, Changgeng; Djuth, Frank T.; Zhou, Qifa; Shung, K. Kirk

2014-01-01

Several micromachining techniques for the fabrication of high-frequency piezoelectric composite ultrasonic array transducers are described in this paper. A variety of different techniques are used in patterning the active piezoelectric material, attaching backing material to the transducer, and assembling an electronic interconnection board for transmission and reception from the array. To establish the feasibility of the process flow, a hybrid test ultrasound array transducer consisting of a 2-D array having an 8 × 8 element pattern and a 5-element annular array was designed, fabricated, and assessed. The arrays are designed for a center frequency of ~60 MHz. The 2-D array elements are 105 × 105 μm in size with 5-μm kerfs between elements. The annular array surrounds the square 2-D array and provides the option of transmitting from the annular array and receiving with the 2-D array. Each annular array element has an area of 0.71 mm2 with a 16-μm kerf between elements. The active piezoelectric material is (1 − x) Pb(Mg1/3Nb2/3)O3−xPbTiO3 (PMN-PT)/epoxy 1–3 composite with a PMN-PT pillar lateral dimension of 8 μm and an average gap width of ~4 μm, which was produced by deep reactive ion etching (DRIE) dry etching techniques. A novel electric interconnection strategy for high-density, small-size array elements was proposed. After assembly, the array transducer was tested and characterized. The capacitance, pulse–echo responses, and crosstalk were measured for each array element. The desired center frequency of ~60 MHz was achieved and the −6-dB bandwidth of the received signal was ~50%. At the center frequency, the crosstalk between adjacent 2-D array elements was about −33 dB. The techniques described herein can be used to build larger arrays containing smaller elements. PMID:24297027

Low-Dose, Long-Wave UV Light Does Not Affect Gene Expression of Human Mesenchymal Stem Cells

PubMed Central

Wong, Darice Y.; Ranganath, Thanmayi; Kasko, Andrea M.

2015-01-01

Light is a non-invasive tool that is widely used in a range of biomedical applications. Techniques such as photopolymerization, photodegradation, and photouncaging can be used to alter the chemical and physical properties of biomaterials in the presence of live cells. Long-wave UV light (315 nm–400 nm) is an easily accessible and commonly used energy source for triggering biomaterial changes. Although exposure to low doses of long-wave UV light is generally accepted as biocompatible, most studies employing this wavelength only establish cell viability, ignoring other possible (non-toxic) effects. Since light exposure of wavelengths longer than 315 nm may potentially induce changes in cell behavior, we examined changes in gene expression of human mesenchymal stem cells exposed to light under both 2D and 3D culture conditions, including two different hydrogel fabrication techniques, decoupling UV exposure and radical generation. While exposure to long-wave UV light did not induce significant changes in gene expression regardless of culture conditions, significant changes were observed due to scaffold fabrication chemistry and between cells plated in 2D versus encapsulated in 3D scaffolds. In order to facilitate others in searching for more specific changes between the many conditions, the full data set is available on Gene Expression Omnibus for querying. PMID:26418040

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

Baker, Kevin L.

The purpose of this LDRD project was to demonstrate high spatial and temporal resolution x-ray imaging using optical detectors, and in particular the VISAR and OHRV diagnostics on the OMEGA laser. The x-ray source being imaged was a backlighter capsule being imploded by 39 beams of the OMEGA laser. In particular this approach utilized a semiconductor with the side facing the backlighter capsule coated with a thin aluminum layer to allow x rays to pass through the metal layer and then get absorbed in the semiconductor. The other side of the semiconductor was AR coated to allow the VISAR ormore » OHRV probe beam to sample the phase change of the semiconductor as the x rays were absorbed in the semiconductor. This technique is capable of acquiring sub-picosecond 2-D or 1-D x-ray images, detector spatial resolution of better than 10 um and the ability to operate in a high neutron flux environment expected on ignition shots with burning plasmas. In addition to demonstrating this technique on the OMEGA laser, several designs were made to improve the phase sensitivity, temporal resolution and number of frames over the existing diagnostics currently implemented on the OMEGA laser. These designs included both 2-d imaging diagnostics as well as improved 1-D imaging diagnostics which were streaked in time.« less

2-D Versus 3-D Cross-Correlation-Based Radial and Circumferential Strain Estimation Using Multiplane 2-D Ultrafast Ultrasound in a 3-D Atherosclerotic Carotid Artery Model.

PubMed

Fekkes, Stein; Swillens, Abigail E S; Hansen, Hendrik H G; Saris, Anne E C M; Nillesen, Maartje M; Iannaccone, Francesco; Segers, Patrick; de Korte, Chris L

2016-10-01

Three-dimensional (3-D) strain estimation might improve the detection and localization of high strain regions in the carotid artery (CA) for identification of vulnerable plaques. This paper compares 2-D versus 3-D displacement estimation in terms of radial and circumferential strain using simulated ultrasound (US) images of a patient-specific 3-D atherosclerotic CA model at the bifurcation embedded in surrounding tissue generated with ABAQUS software. Global longitudinal motion was superimposed to the model based on the literature data. A Philips L11-3 linear array transducer was simulated, which transmitted plane waves at three alternating angles at a pulse repetition rate of 10 kHz. Interframe (IF) radio-frequency US data were simulated in Field II for 191 equally spaced longitudinal positions of the internal CA. Accumulated radial and circumferential displacements were estimated using tracking of the IF displacements estimated by a two-step normalized cross-correlation method and displacement compounding. Least-squares strain estimation was performed to determine accumulated radial and circumferential strain. The performance of the 2-D and 3-D methods was compared by calculating the root-mean-squared error of the estimated strains with respect to the reference strains obtained from the model. More accurate strain images were obtained using the 3-D displacement estimation for the entire cardiac cycle. The 3-D technique clearly outperformed the 2-D technique in phases with high IF longitudinal motion. In fact, the large IF longitudinal motion rendered it impossible to accurately track the tissue and cumulate strains over the entire cardiac cycle with the 2-D technique.

High temporal and high spatial resolution MR angiography (4D-MRA).

PubMed

Hadizadeh, D R; Marx, C; Gieseke, J; Schild, H H; Willinek, W A

2014-09-01

In the first decade of the twenty-first century, whole-body magnetic resonance scanners with high field strengths (and thus potentially better signal-to-noise ratios) were developed. At the same time, parallel imaging and "echo-sharing" techniques were refined to allow for increasingly high spatial and temporal resolution in dynamic magnetic resonance angiography ("time-resolved" = TR-MRA). This technological progress facilitated tracking the passage of intra-venously administered contrast agent boluses as well as the acquisition of volume data sets at high image refresh rates ("4D-MRA"). This opened doors for many new applications in non-invasive vascular imaging, including simultaneous anatomic and functional analysis of many vascular pathologies including arterio-venous malformations. Different methods were established to acquire 4D-MRA using various strategies to acquire k-space trajectories over time in order to optimize imaging according to clinical needs. These include "keyhole"-based techniques (e. g. 4D-TRAK), TRICKS - both with and without projection - and HYPR-reconstruction, TREAT, and TWIST. Some of these techniques were first introduced in the 1980 s and 1990 s, were later enhanced and modified, and finally implemented in the products of major vendors. In the last decade, a large number of studies on the clinical applications of TR-MRA was published. This manuscript provides an overview of the development of TR-MRA methods and the 4D-MRA techniques as they are currently used in the diagnosis, treatment and follow-up of vascular diseases in various parts of the body. © Georg Thieme Verlag KG Stuttgart · New York.

Delayed Gamma-ray Spectroscopy for Safeguards Applications

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

Mozin, Vladimir

The delayed gamma-ray assay technique utilizes an external neutron source (D-D, D-T, or electron accelerator-driven), and high-resolution gamma-ray spectrometers to perform characterization of SNM materials behind shielding and in complex configurations such as a nuclear fuel assembly. High-energy delayed gamma-rays (2.5 MeV and above) observed following the active interrogation, provide a signature for identification of specific fissionable isotopes in a mixed sample, and determine their relative content. Potential safeguards applications of this method are: 1) characterization of fresh and spent nuclear fuel assemblies in wet or dry storage; 2) analysis of uranium enrichment in shielded or non-characterized containers or inmore » the presence of a strong radioactive background and plutonium contamination; 3) characterization of bulk and waste and product streams at SNM processing plants. Extended applications can include warhead confirmation and warhead dismantlement confirmation in the arms control area, as well as SNM diagnostics for the emergency response needs. In FY16 and prior years, the project has demonstrated the delayed gamma-ray measurement technique as a robust SNM assay concept. A series of empirical and modeling studies were conducted to characterize its response sensitivity, develop analysis methodologies, and analyze applications. Extensive experimental tests involving weapons-grade Pu, HEU and depleted uranium samples were completed at the Idaho Accelerator Center and LLNL Dome facilities for various interrogation time regimes and effects of the neutron source parameters. A dedicated delayed gamma-ray response modeling technique was developed and its elements were benchmarked in representative experimental studies, including highresolution gamma-ray measurements of spent fuel at the CLAB facility in Sweden. The objective of the R&D effort in FY17 is to experimentally demonstrate the feasibility of the delayed gamma-ray interrogation of shielded SNM samples with portable neutron sources suitable for field applications.« less

3D Printing Based on Cardiac CT Assists Anatomic Visualization Prior to Transcatheter Aortic Valve Replacement

PubMed Central

Ripley, Beth; Kelil, Tatiana; Cheezum, Michael K.; Goncalves, Alexandra; Di Carli, Marcelo F.; Rybicki, Frank J.; Steigner, Mike; Mitsouras, Dimitrios; Blankstein, Ron

2017-01-01

Background 3D printing is a promising technique that may have applications in medicine, and there is expanding interest in the use of patient-specific 3D models to guide surgical interventions. Objective To determine the feasibility of using cardiac CT to print individual models of the aortic root complex for transcatheter aortic valve replacement (TAVR) planning as well as to determine the ability to predict paravalvular aortic regurgitation (PAR). Methods This retrospective study included 16 patients (9 with PAR identified on blinded interpretation of post-procedure trans-thoracic echocardiography and 7 age, sex, and valve size-matched controls with no PAR). 3D printed models of the aortic root were created from pre-TAVR cardiac computed tomography data. These models were fitted with printed valves and predictions regarding post-implant PAR were made using a light transmission test. Results Aortic root 3D models were highly accurate, with excellent agreement between annulus measurements made on 3D models and those made on corresponding 2D data (mean difference of −0.34 mm, 95% limits of agreement: ± 1.3 mm). The 3D printed valve models were within 0.1 mm of their designed dimensions. Examination of the fit of valves within patient-specific aortic root models correctly predicted PAR in 6 of 9 patients (6 true positive, 3 false negative) and absence of PAR in 5 of 7 patients (5 true negative, 2 false positive). Conclusions Pre-TAVR 3D-printing based on cardiac CT provides a unique patient-specific method to assess the physical interplay of the aortic root and implanted valves. With additional optimization, 3D models may complement traditional techniques used for predicting which patients are more likely to develop PAR. PMID:26732862

Additive lattice kirigami

PubMed Central

Castle, Toen; Sussman, Daniel M.; Tanis, Michael; Kamien, Randall D.

2016-01-01

Kirigami uses bending, folding, cutting, and pasting to create complex three-dimensional (3D) structures from a flat sheet. In the case of lattice kirigami, this cutting and rejoining introduces defects into an underlying 2D lattice in the form of points of nonzero Gaussian curvature. A set of simple rules was previously used to generate a wide variety of stepped structures; we now pare back these rules to their minimum. This allows us to describe a set of techniques that unify a wide variety of cut-and-paste actions under the rubric of lattice kirigami, including adding new material and rejoining material across arbitrary cuts in the sheet. We also explore the use of more complex lattices and the different structures that consequently arise. Regardless of the choice of lattice, creating complex structures may require multiple overlapping kirigami cuts, where subsequent cuts are not performed on a locally flat lattice. Our additive kirigami method describes such cuts, providing a simple methodology and a set of techniques to build a huge variety of complex 3D shapes. PMID:27679822

Additive lattice kirigami.

PubMed

Castle, Toen; Sussman, Daniel M; Tanis, Michael; Kamien, Randall D

2016-09-01

Kirigami uses bending, folding, cutting, and pasting to create complex three-dimensional (3D) structures from a flat sheet. In the case of lattice kirigami, this cutting and rejoining introduces defects into an underlying 2D lattice in the form of points of nonzero Gaussian curvature. A set of simple rules was previously used to generate a wide variety of stepped structures; we now pare back these rules to their minimum. This allows us to describe a set of techniques that unify a wide variety of cut-and-paste actions under the rubric of lattice kirigami, including adding new material and rejoining material across arbitrary cuts in the sheet. We also explore the use of more complex lattices and the different structures that consequently arise. Regardless of the choice of lattice, creating complex structures may require multiple overlapping kirigami cuts, where subsequent cuts are not performed on a locally flat lattice. Our additive kirigami method describes such cuts, providing a simple methodology and a set of techniques to build a huge variety of complex 3D shapes.

Application of Magnetic Resonance Imaging and Three-Dimensional Treatment Planning in the Treatment of Orbital Lymphoma

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

Rudoltz, Marc S.; Ayyangar, Komanduri; Mohiuddin, Mohammed

Radiotherapy for lymphoma of the orbit must be individualized for each patient and clinical setting. Most techniques focus on optimizing the dose to the tumor while sparing the lens. This study describes a technique utilizing magnetic resonance imaging (MRI) and three dimensional (3D) planning in the treatment of orbital lymphoma. A patient presented with an intermediate grade lymphoma of the right orbit. The prescribed tumor dose was 4050 cGy in 18 fractions. Three D planning was carried out and tumor volumes, retina, and lens were subsequently outlined. Dose calculations including dose volume histograms of the target, retina, and lens weremore » then performed. Part of the retina was outside of the treatment volume while 50% of the retina received 90% or more of the prescribed dose. The patient was clinically NED when last seen 2 years following therapy with no treatment-related morbidity. Patients with lymphomas of the orbit can be optimally treated using MRI based 3D treatment planning.« less

Assessment of groundwater potentiality using geophysical techniques in Wadi Allaqi basin, Eastern Desert, Egypt - Case study

NASA Astrophysics Data System (ADS)

Helaly, Ahmad Sobhy

2017-12-01

Electrical resistivity surveying has been carried out for the determination of the thickness and resistivity of layered media in Wadi Allaqi, Eastern Desert, Egypt. That is widely used geophysical tool for the purpose of assessing the groundwater potential and siting the best locations for boreholes in the unconfined Nubian Sandstone aquifers within the study area. This has been done using thirteen 1D Vertical Electrical Sounding (VES) surveys. 1D-VES surveys provide only layered model structures for the subsurface and do not provide comprehensive information for interpreting the structure and extent of subsurface hydro-geological features. The integration of two-dimensional (2D) geophysical techniques for groundwater prospecting has been done to provide a more detailed identification for the subsurface hydro-geological features from which potential sites for successful borehole locations are recognized. In addition, five magnetic profiles were measured for basement depth determination, expected geological structures and thickness of sedimentary succession that could include some basins suitable for groundwater accumulation as groundwater aquifers.

A survey of clearing techniques for 3D imaging of tissues with special reference to connective tissue.

PubMed

Azaripour, Adriano; Lagerweij, Tonny; Scharfbillig, Christina; Jadczak, Anna Elisabeth; Willershausen, Brita; Van Noorden, Cornelis J F

2016-08-01

For 3-dimensional (3D) imaging of a tissue, 3 methodological steps are essential and their successful application depends on specific characteristics of the type of tissue. The steps are 1° clearing of the opaque tissue to render it transparent for microscopy, 2° fluorescence labeling of the tissues and 3° 3D imaging. In the past decades, new methodologies were introduced for the clearing steps with their specific advantages and disadvantages. Most clearing techniques have been applied to the central nervous system and other organs that contain relatively low amounts of connective tissue including extracellular matrix. However, tissues that contain large amounts of extracellular matrix such as dermis in skin or gingiva are difficult to clear. The present survey lists methodologies that are available for clearing of tissues for 3D imaging. We report here that the BABB method using a mixture of benzyl alcohol and benzyl benzoate and iDISCO using dibenzylether (DBE) are the most successful methods for clearing connective tissue-rich gingiva and dermis of skin for 3D histochemistry and imaging of fluorescence using light-sheet microscopy. Copyright © 2016 The Authors. Published by Elsevier GmbH.. All rights reserved.

Cancer drug discovery: recent innovative approaches to tumor modeling.

PubMed

Lovitt, Carrie J; Shelper, Todd B; Avery, Vicky M

2016-09-01

Cell culture models have been at the heart of anti-cancer drug discovery programs for over half a century. Advancements in cell culture techniques have seen the rapid evolution of more complex in vitro cell culture models investigated for use in drug discovery. Three-dimensional (3D) cell culture research has become a strong focal point, as this technique permits the recapitulation of the tumor microenvironment. Biologically relevant 3D cellular models have demonstrated significant promise in advancing cancer drug discovery, and will continue to play an increasing role in the future. In this review, recent advances in 3D cell culture techniques and their application in tumor modeling and anti-cancer drug discovery programs are discussed. The topics include selection of cancer cells, 3D cell culture assays (associated endpoint measurements and analysis), 3D microfluidic systems and 3D bio-printing. Although advanced cancer cell culture models and techniques are becoming commonplace in many research groups, the use of these approaches has yet to be fully embraced in anti-cancer drug applications. Furthermore, limitations associated with analyzing information-rich biological data remain unaddressed.

Realization and characterization of a beam of titanium atoms

NASA Astrophysics Data System (ADS)

Azaroual, E. M.; Luc, P.; Vetter, R.

1992-06-01

A dense thermal beam of titanium atoms has been realized using a tungsten crucible inside a high temperature oven (leqslant 2 300 K). Its flux (≈ 10^{14} atom/cm^2/s) and its long term stability have been measured by means of a quartz balance, its angular divergence has been evaluated from the size of a metallic spot deposited on a glass plate. A spectroscopic investigation performed via the laser-induced fluorescence technique has led to the measurement of the isotope shifts between ^{46}Ti, ^{48}Ti and ^{50}Ti, for six visible 3d^2 4s^2 a ^3FJ''to 3d^2 4s4p z ^5DJ' transitions. This beam offers the characteristics required to apply high resolution laser techniques to reaction dynamics crossed-beam experiments. Un jet intense de titane atomique a été réalisé à partir d'un creuset de tungstène porté à haute température (leqslant 2 300 K). Le flux (≈ 10^{14} atomes/cm^2/s) et la stabilité à long terme du jet ont été mesurés avec une balance à quartz ; la divergence angulaire a été évaluée à partir de la dimension de dépôts métalliques sur des lames-témoin. Le jet a également été caractérisé par spectroscopie : la technique de fluorescence induite par laser a permis de mesurer le déplacement spectral dû aux isotopes 46, 48 et 50 de Ti, pour six transitions visibles du type 3d^2 4s^2 a ^3FJ''to 3d^2 4s4p z ^5DJ'. Le jet réalisé offre les caractéristiques requises pour l'application des techniques laser à haute résolution aux expériences de dynamique réactionnelle en faisceaux croisés.

Postoperative outcomes of two- and three-dimensional planning in orthognathic surgery: A comparative study.

PubMed

Wu, Ting-Yu; Lin, Hsiu-Hsia; Lo, Lun-Jou; Ho, Cheng-Ting

2017-08-01

Compared with conventional two-dimensional (2D) planning, three-dimensional (3D) planning in orthognathic surgery yields more accurate anatomical information and enables the precise positioning of maxillary and mandibular segments, particularly for patients with facial asymmetry. Accordingly, surgical outcomes achieved using 3D planning should be superior. This study determined the differences between the 2D and 3D planning techniques by comparing their surgical outcomes. In this retrospective study, patients who underwent surgery following the traditional 2D planning technique were classified into the 2D planning group. Patients in whom the 2D plan was transferred to a 3D system after surgical simulation were classified into the 3D planning group. Surgical outcomes were compared using cephalometric measurements and patient perception of the results. In the 3D planning group, more favorable results were observed in frontal symmetry, change in the angle between the orbital and occlusal lines, frontal ramus inclination, and the distances from the mandibular central incisor and menton to the midsagittal line. No significant differences were observed in the lateral profiles (SNA, SNB, ANB, and angle convexity) of the two groups. Patient satisfaction was favorable in the two groups, but more patients in the 3D planning group reported being very satisfied. The 3D planning technique provided superior overall outcomes. The study findings can be used to augment clinical planning and surgical execution when using a conventional approach. Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Three dimensional scattering center imaging techniques

NASA Technical Reports Server (NTRS)

Younger, P. R.; Burnside, W. D.

1991-01-01

Two methods to image scattering centers in 3-D are presented. The first method uses 2-D images generated from Inverse Synthetic Aperture Radar (ISAR) measurements taken by two vertically offset antennas. This technique is shown to provide accurate 3-D imaging capability which can be added to an existing ISAR measurement system, requiring only the addition of a second antenna. The second technique uses target impulse responses generated from wideband radar measurements from three slightly different offset antennas. This technique is shown to identify the dominant scattering centers on a target in nearly real time. The number of measurements required to image a target using this technique is very small relative to traditional imaging techniques.

Use of micro-photoluminescence as a contactless measure of the 2D electron density in a GaAs quantum well

NASA Astrophysics Data System (ADS)

Kamburov, D.; Baldwin, K. W.; West, K. W.; Lyon, S.; Pfeiffer, L. N.; Pinczuk, A.

2017-06-01

We compare micro-photoluminescence (μPL) as a measure of the electron density in a clean, two-dimensional (2D) system confined in a GaAs quantum well (QW) to the standard magneto-transport technique. Our study explores the PL shape evolution across a number of molecular beam epitaxy-grown samples with different QW widths and 2D electron densities and notes its correspondence with the density obtained in magneto-transport measurements on these samples. We also measure the 2D density in a top-gated quantum well sample using both PL and transport and find that the two techniques agree to within a few percent over a wide range of gate voltages. We find that the PL measurements are sensitive to gate-induced 2D density changes on the order of 109 electrons/cm2. The spatial resolution of the PL density measurement in our experiments is 40 μm, which is already substantially better than the millimeter-scale resolution now possible in spatial density mapping using magneto-transport. Our results establish that μPL can be used as a reliable high spatial resolution technique for future contactless measurements of density variations in a 2D electron system.

Quantitative pre-clinical screening of therapeutics for joint diseases using contrast enhanced micro-computed tomography.

PubMed

Willett, N J; Thote, T; Hart, M; Moran, S; Guldberg, R E; Kamath, R V

2016-09-01

The development of effective therapies for cartilage protection has been limited by a lack of efficient quantitative cartilage imaging modalities in pre-clinical in vivo models. Our objectives were two-fold: first, to validate a new contrast-enhanced 3D imaging analysis technique, equilibrium partitioning of an ionic contrast agent-micro computed tomography (EPIC-μCT), in a rat medial meniscal transection (MMT) osteoarthritis (OA) model; and second, to quantitatively assess the sensitivity of EPIC-μCT to detect the effects of matrix metalloproteinase inhibitor (MMPi) therapy on cartilage degeneration. Rats underwent MMT surgery and tissues were harvested at 1, 2, and 3 weeks post-surgery or rats received an MMPi or vehicle treatment and tissues harvested 3 weeks post-surgery. Parameters of disease progression were evaluated using histopathology and EPIC-μCT. Correlations and power analyses were performed to compare the techniques. EPIC-μCT was shown to provide simultaneous 3D quantification of multiple parameters, including cartilage degeneration and osteophyte formation. In MMT animals treated with MMPi, OA progression was attenuated, as measured by 3D parameters such as lesion volume and osteophyte size. A post-hoc power analysis showed that 3D parameters for EPIC-μCT were more sensitive than 2D parameters requiring fewer animals to detect a therapeutic effect of MMPi. 2D parameters were comparable between EPIC-μCT and histopathology. This study demonstrated that EPIC-μCT has high sensitivity to provide 3D structural and compositional measurements of cartilage and bone in the joint. EPIC-μCT can be used in combination with histology to provide a comprehensive analysis to screen new potential therapies. Copyright © 2016 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

[Use of four kinds of three-dimensional printing guide plate in bone tumor resection and reconstruction operation].

PubMed

Fu, Jun; Guo, Zheng; Wang, Zhen; Li, Xiangdong; Fan, Hongbin; Li, Jing; Pei, Yanjun; Pei, Guoxian; Li, Dan

2014-03-01

To explore the effectiveness of excision and reconstruction of bone tumor by using operation guide plate made by variety of three-dimensional (3-D) printing techniques, and to compare the advantages and disadvantages of different 3-D printing techniques in the manufacture and application of operation guide plate. Between September 2012 and January 2014, 31 patients with bone tumor underwent excision and reconstruction of bone tumor by using operation guide plate. There were 19 males and 12 females, aged 6-67 years (median, 23 years). The disease duration ranged from 15 days to 12 months (median, 2 months). There were 13 cases of malignant tumor and 18 cases of benign tumor. The tumor located in the femur (9 cases), the spine (7 cases), the tibia (6 cases), the pelvis (5 cases), the humerus (3 cases), and the fibula (1 case). Four kinds of 3-D printing technique were used in processing operation guide plate: fused deposition modeling (FDM) in 9 cases, stereo lithography appearance (SLA) in 14 cases, 3-D printing technique in 5 cases, and selective laser sintering (SLS) in 3 cases; the materials included ABS resin, photosensitive resin, plaster, and aluminum alloy, respectively. Before operation, all patients underwent thin layer CT scanning (0.625 mm) in addition to conventional imaging. The data were collected for tumor resection design, and operation guide plate was designed on the basis of excision plan. Preoperatively, the operation guide plates were made by 3-D printing equipment. After sterilization, the guide plates were used for excision and reconstruction of bone tumor. The time of plates processing cycle was recorded to analyse the efficiency of 4 kinds of 3-D printing techniques. The time for design and operation and intraoperative fluoroscopy frequency were recorded. Twenty-eight patients underwent similar operations during the same period as the control group. The processing time of operation guide plate was (19.3 +/- 6.5) hours in FDM, (5.2 +/- 1.3) hours in SLA, (8.6 +/- 1.9) hours in 3-D printing technique, and (51.7 +/- 12.9) hours in SLS. The preoperative design and operation guide plate were successfully made, which was used for excision and reconstruction of bone tumor in 31 cases. Except 3 failures (operation guide plate fracture), the resection and reconstruction operations followed the preoperative design in the other 28 cases. The patients had longer design time, shorter operation time, and less fluoroscopy frequency than the patients of the control group, showing significant differences (P < 0.05). The follow-up time was 1-12 months (mean, 3.7 months). Postoperative X-ray and CT showed complete tumor resection and stable reconstruction. 3-D printing operation guide plates are well adapted to the requirements of individual operation for bone tumor resection and reconstruction. The 4 kinds of 3-D printing techniques have their own advantages and should be chosen according to the need of operation.

Autonomous space target recognition and tracking approach using star sensors based on a Kalman filter.

PubMed

Ye, Tao; Zhou, Fuqiang

2015-04-10

When imaged by detectors, space targets (including satellites and debris) and background stars have similar point-spread functions, and both objects appear to change as detectors track targets. Therefore, traditional tracking methods cannot separate targets from stars and cannot directly recognize targets in 2D images. Consequently, we propose an autonomous space target recognition and tracking approach using a star sensor technique and a Kalman filter (KF). A two-step method for subpixel-scale detection of star objects (including stars and targets) is developed, and the combination of the star sensor technique and a KF is used to track targets. The experimental results show that the proposed method is adequate for autonomously recognizing and tracking space targets.

A controlled clinical trial testing two potentially non-cross-resistant chemotherapeutic regimens in small-cell carcinoma of the lung.

PubMed

Broder, L E; Selawry, O S; Charyulu, K N; Ng, A; Bagwell, S

1981-03-01

With the objectives of improving response rate, duration of response, and survival in small-cell carcinoma of the lung, 39 patients were randomized to remission-induction with either one of two potentially non-cross-resistant drug combinations: APE (consisting of adriamycin, 35 mg/m2 IV, D1 Q 3 weeks; procarbazine, 60 mg/m2 PO, D1-10 Q 3 weeks; and the epipodophyllotoxin (VP16-213), 130 mg/m2 IV, D8, 15 Q 3 weeks) or MOCC (composed of methotrexate, 15 mg/m2 IV (with [vincristine] Oncovin) or PO twice weekly D8-21 Q 3 weeks; Oncovin, 1.5 mg/m2 IV, D8, 15 Q 3 weeks; cyclophosphamide, 600 mg/m2 IV, D1 Q 3 weeks, and CCNU, 60 mg/m2 PO Q 6 weeks). A fixed crossover to the alternate regimen occurred at three months. Radiotherapy was delivered to the primary tumor (locoregional disease only) by a split course technique (1,750 rads for five days with a three-week split, followed by 3,400 rads over 17 days). The median survival including both arms was 11 months for regional and nine months for extensive disease. The chemotherapeutic activity of both regimens was comparable, with 15/17 (88 percent) of the patients responding to APE (including six complete) and 14/17 (82 percent) responding to MOCC (including five complete). The median survival for the complete responders was 11.7 months, while the partial responders survived for a median of 9.7 months. There were 2/9 (22 percent) responders to the alternate regimen at progressive disease. The overall incidence of CNS progression was 17 percent. The toxicity of the regimens was moderate, except for one instance of granulocytopenic death. This study establishes two equipotent drug combinations for the treatment of small-cell carcinoma of the lung.

Evaluation of a novel educational strategy, including inhaler-based reminder labels, to improve asthma inhaler technique.

PubMed

Basheti, Iman A; Armour, Carol L; Bosnic-Anticevich, Sinthia Z; Reddel, Helen K

2008-07-01

To evaluate the feasibility, acceptability and effectiveness of a brief intervention about inhaler technique, delivered by community pharmacists to asthma patients. Thirty-one pharmacists received brief workshop education (Active: n=16, CONTROL: n=15). Active Group pharmacists were trained to assess and teach dry powder inhaler technique, using patient-centered educational tools including novel Inhaler Technique Labels. Interventions were delivered to patients at four visits over 6 months. At baseline, patients (Active: 53, CONTROL: 44) demonstrated poor inhaler technique (mean+/-S.D. score out of 9, 5.7+/-1.6). At 6 months, improvement in inhaler technique score was significantly greater in Active cf. CONTROL patients (2.8+/-1.6 cf. 0.9+/-1.4, p<0.001), and asthma severity was significantly improved (p=0.015). Qualitative responses from patients and pharmacists indicated a high level of satisfaction with the intervention and educational tools, both for their effectiveness and for their impact on the patient-pharmacist relationship. A simple feasible intervention in community pharmacies, incorporating daily reminders via Inhaler Technique Labels on inhalers, can lead to improvement in inhaler technique and asthma outcomes. Brief training modules and simple educational tools, such as Inhaler Technique Labels, can provide a low-cost and sustainable way of changing patient behavior in asthma, using community pharmacists as educators.

Mixed Dimensional Van der Waals Heterostructures for Opto-Electronics.

NASA Astrophysics Data System (ADS)

Jariwala, Deep

The isolation of a growing number of two-dimensional (2D) materials has inspired worldwide efforts to integrate distinct 2D materials into van der Waals (vdW) heterostructures. While a tremendous amount of research activity has occurred in assembling disparate 2D materials into ``all-2D'' van der Waals heterostructures, this concept is not limited to 2D materials alone. Given that any passivated, dangling bond-free surface will interact with another via vdW forces, the vdW heterostructure concept can be extended to include the integration of 2D materials with non-2D materials that adhere primarily through noncovalent interactions. In the first part of this talk I will present our work on emerging mixed-dimensional (2D + nD, where n is 0, 1 or 3) heterostructure devices performed at Northwestern University. I will present two distinct examples of gate-tunable p-n heterojunctions 1. Single layer n-type MoS2\\ (2D) combined with p-type semiconducting single walled carbon nanotubes (1D) and 2. Single layer MoS2 combined with 0D molecular semiconductor, pentacene. I will present the unique electrical properties, underlying charge transport mechanisms and photocurrent responses in both the above systems using a variety of scanning probe microscopy techniques as well as computational analysis. This work shows that van der Waals interactions are robust across different dimensionalities of materials and can allow fabrication of semiconductor devices with unique geometries and properties unforeseen in bulk semiconductors. Finally, I will briefly discuss our recent work from Caltech on near-unity absorption in atomically-thin photovoltaic devices. This work is supported by the Materials Research Center at Northwestern University, funded by the National Science Foundation (NSF DMR-1121262) and the Resnick Sustainability Institute at Caltech.

A systematic literature review of health state utility values in head and neck cancer.

PubMed

Meregaglia, Michela; Cairns, John

2017-09-02

Health state utility values (HSUVs) are essential parameters in model-based economic evaluations. This study systematically identifies HSUVs in head and neck cancer and provides guidance for selecting them from a growing body of health-related quality of life studies. We systematically reviewed the published literature by searching PubMed, EMBASE and The Cochrane Library using a pre-defined combination of keywords. The Tufts Cost-Effectiveness Analysis Registry and the School of Health and Related Research Health Utilities Database (ScHARRHUD) specifically containing health utilities were also queried, in addition to the Health Economics Research Centre database of mapping studies. Studies were considered for inclusion if reporting original HSUVs assessed using established techniques. The characteristics of each study including country, design, sample size, cancer subsite addressed and demographics of responders were summarized narratively using a data extraction form. Quality scoring and critical appraisal of the included studies were performed based on published recommendations. Of a total 1048 records identified by the search, 28 studies qualified for data extraction and 346 unique HSUVs were retrieved from them. HSUVs were estimated using direct methods (e.g. standard gamble; n = 10 studies), multi-attribute utility instruments (MAUIs; n = 13) and mapping techniques (n = 3); two studies adopted both direct and indirect approaches. Within the MAUIs, the EuroQol 5-dimension questionnaire (EQ-5D) was the most frequently used (n = 11), followed by the Health Utility Index Mark 3 (HUI3; n = 2), the 15D (n = 2) and the Short Form-Six Dimension (SF-6D; n = 1). Different methods and types of responders (i.e. patients, healthy subjects, clinical experts) influenced the magnitude of HSUVs for comparable health states. Only one mapping study developed an original algorithm using head and neck cancer data. The identified studies were considered of intermediate quality. This review provides a dataset of HSUVs systematically retrieved from published studies in head and neck cancer. There is currently a lack of research for some disease phases including recurrent and metastatic cancer, and treatment-related complications. In selecting HSUVs for cost-effectiveness modeling purposes, preference should be given to EQ-5D utility values; however, mapping to EQ-5D is a potentially valuable technique that should be further developed in this cancer population.

Novel Biomaterials Used in Medical 3D Printing Techniques

PubMed Central

Tappa, Karthik; Jammalamadaka, Udayabhanu

2018-01-01

The success of an implant depends on the type of biomaterial used for its fabrication. An ideal implant material should be biocompatible, inert, mechanically durable, and easily moldable. The ability to build patient specific implants incorporated with bioactive drugs, cells, and proteins has made 3D printing technology revolutionary in medical and pharmaceutical fields. A vast variety of biomaterials are currently being used in medical 3D printing, including metals, ceramics, polymers, and composites. With continuous research and progress in biomaterials used in 3D printing, there has been a rapid growth in applications of 3D printing in manufacturing customized implants, prostheses, drug delivery devices, and 3D scaffolds for tissue engineering and regenerative medicine. The current review focuses on the novel biomaterials used in variety of 3D printing technologies for clinical applications. Most common types of medical 3D printing technologies, including fused deposition modeling, extrusion based bioprinting, inkjet, and polyjet printing techniques, their clinical applications, different types of biomaterials currently used by researchers, and key limitations are discussed in detail. PMID:29414913

Dietary Protein Requirement of Men >65 Years Old Determined by the Indicator Amino Acid Oxidation Technique Is Higher than the Current Estimated Average Requirement.

PubMed

Rafii, Mahroukh; Chapman, Karen; Elango, Rajavel; Campbell, Wayne W; Ball, Ronald O; Pencharz, Paul B; Courtney-Martin, Glenda

2016-03-09

The current estimated average requirement (EAR) and RDA for protein of 0.66 and 0.8 g ⋅ kg -1 ⋅ d -1 , respectively, for adults, including older men, are based on nitrogen balance data analyzed by monolinear regression. Recent studies in young men and older women that used the indicator amino acid oxidation (IAAO) technique suggest that those values may be too low. This observation is supported by 2-phase linear crossover analysis of the nitrogen balance data. The main objective of this study was to determine the protein requirement for older men by using the IAAO technique. Six men aged >65 y were studied; each individual was tested 7 times with protein intakes ranging from 0.2 to 2.0 g ⋅ kg -1 ⋅ d -1 in random order for a total of 42 studies. The diets provided energy at 1.5 times the resting energy expenditure and were isocaloric. Protein was consumed hourly for 8 h as an amino acid mixture with the composition of egg protein with l-[1- 13 C]phenylalanine as the indicator amino acid. The group mean protein requirement was determined by applying a mixed-effects change-point regression analysis to F 13 CO 2 (label tracer oxidation in breath 13 CO 2 ), which identified a breakpoint in F 13 CO 2 in response to graded intakes of protein. The estimated protein requirement and RDA for older men were 0.94 and 1.24 g ⋅ kg -1 ⋅ d -1 , respectively, which are not different from values we published using the same method in young men and older women. The current intake recommendations for older adults for dietary protein of 0.66 g ⋅ kg -1 ⋅ d -1 for the EAR and 0.8 g ⋅ kg -1 ⋅ d -1 for the RDA appear to be underestimated by ∼30%. Future longer-term studies should be conducted to validate these results. This trial was registered at clinicaltrials.gov as NCT01948492. © 2016 American Society for Nutrition.

Biotechnological production of enantiomerically pure d-lactic acid.

PubMed

Klotz, Silvia; Kaufmann, Norman; Kuenz, Anja; Prüße, Ulf

2016-11-01

The fermentation process of l-lactic acid is well known. Little importance was attached to d-lactic acid, but in the past 10 years, d-lactic acid gained significantly in importance. d-Lactic acid is an interesting precursor for manufacturing heat-resistant polylactic acid (PLA) bioplastics which can be widely used, for example as packaging material, coatings, for textiles or in the automotive industry.This review provides a comprehensive overview of the most recent developments, including a spectrum of studied microorganisms and their capabilities for the production of d-lactic acid. Additionally, the technological achievements in biotechnological d-lactic acid production including fermentation techniques like fed batch, simultaneous saccharification, and fermentation and continuous techniques are presented. Attention is also turned to suitable alternative substrates and their applicability in fermentation processes. Furthermore, advantages and disadvantages of product recovery and purification are discussed. Economic aspects of PLA are pointed out, and the present industrial producers of lactic acid are briefly introduced.

Isothermal DNA origami folding: avoiding denaturing conditions for one-pot, hybrid-component annealing

NASA Astrophysics Data System (ADS)

Kopielski, Andreas; Schneider, Anne; Csáki, Andrea; Fritzsche, Wolfgang

2015-01-01

The DNA origami technique offers great potential for nanotechnology. Using biomolecular self-assembly, defined 2D and 3D nanoscale DNA structures can be realized. DNA origami allows the positioning of proteins, fluorophores or nanoparticles with an accuracy of a few nanometers and enables thereby novel nanoscale devices. Origami assembly usually includes a thermal denaturation step at 90 °C. Additional components used for nanoscale assembly (such as proteins) are often thermosensitive, and possibly damaged by such harsh conditions. They have therefore to be attached in an extra second step to avoid defects. To enable a streamlined one-step nanoscale synthesis - a so called one-pot folding - an adaptation of the folding procedures is required. Here we present a thermal optimization of this process for a 2D DNA rectangle-shaped origami resulting in an isothermal assembly protocol below 60 °C without thermal denaturation. Moreover, a room temperature protocol is presented using the chemical additive betaine, which is biocompatible in contrast to chemical denaturing approaches reported previously.The DNA origami technique offers great potential for nanotechnology. Using biomolecular self-assembly, defined 2D and 3D nanoscale DNA structures can be realized. DNA origami allows the positioning of proteins, fluorophores or nanoparticles with an accuracy of a few nanometers and enables thereby novel nanoscale devices. Origami assembly usually includes a thermal denaturation step at 90 °C. Additional components used for nanoscale assembly (such as proteins) are often thermosensitive, and possibly damaged by such harsh conditions. They have therefore to be attached in an extra second step to avoid defects. To enable a streamlined one-step nanoscale synthesis - a so called one-pot folding - an adaptation of the folding procedures is required. Here we present a thermal optimization of this process for a 2D DNA rectangle-shaped origami resulting in an isothermal assembly protocol below 60 °C without thermal denaturation. Moreover, a room temperature protocol is presented using the chemical additive betaine, which is biocompatible in contrast to chemical denaturing approaches reported previously. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr04176c

Sliding-slab three-dimensional TSE imaging with a spiral-In/Out readout.

PubMed

Li, Zhiqiang; Wang, Dinghui; Robison, Ryan K; Zwart, Nicholas R; Schär, Michael; Karis, John P; Pipe, James G

2016-02-01

T2 -weighted imaging is of great diagnostic value in neuroimaging. Three-dimensional (3D) Cartesian turbo spin echo (TSE) scans provide high signal-to-noise ratio (SNR) and contiguous slice coverage. The purpose of this preliminary work is to implement a novel 3D spiral TSE technique with image quality comparable to 2D/3D Cartesian TSE. The proposed technique uses multislab 3D TSE imaging. To mitigate the slice boundary artifacts, a sliding-slab method is extended to spiral imaging. A spiral-in/out readout is adopted to minimize the artifacts that may be present with the conventional spiral-out readout. Phase errors induced by B0 eddy currents are measured and compensated to allow for the combination of the spiral-in and spiral-out images. A nonuniform slice encoding scheme is used to reduce the truncation artifacts while preserving the SNR performance. Preliminary results show that each of the individual measures contributes to the overall performance, and the image quality of the results obtained with the proposed technique is, in general, comparable to that of 2D or 3D Cartesian TSE. 3D sliding-slab TSE with a spiral-in/out readout provides good-quality T2 -weighted images, and, therefore, may become a promising alternative to Cartesian TSE. © 2015 Wiley Periodicals, Inc.

A synthetic seismicity model for the Middle America Trench

NASA Technical Reports Server (NTRS)

Ward, Steven N.

1991-01-01

A novel iterative technique, based on the concept of fault segmentation and computed using 2D static dislocation theory, for building models of seismicity and fault interaction which are physically acceptable and geometrically and kinematically correct, is presented. The technique is applied in two steps to seismicity observed at the Middle America Trench. The first constructs generic models which randomly draw segment strengths and lengths from a 2D probability distribution. The second constructs predictive models in which segment lengths and strengths are adjusted to mimic the actual geography and timing of large historical earthquakes. Both types of models reproduce the statistics of seismicity over five units of magnitude and duplicate other aspects including foreshock and aftershock sequences, migration of foci, and the capacity to produce both characteristic and noncharacteristic earthquakes. Over a period of about 150 yr the complex interaction of fault segments and the nonlinear failure conditions conspire to transform an apparently deterministic model into a chaotic one.

Frequency-domain nonlinear optics in two-dimensionally patterned quasi-phase-matching media.

PubMed

Phillips, C R; Mayer, B W; Gallmann, L; Keller, U

2016-07-11

Advances in the amplification and manipulation of ultrashort laser pulses have led to revolutions in several areas. Examples include chirped pulse amplification for generating high peak-power lasers, power-scalable amplification techniques, pulse shaping via modulation of spatially-dispersed laser pulses, and efficient frequency-mixing in quasi-phase-matched nonlinear crystals to access new spectral regions. In this work, we introduce and demonstrate a new platform for nonlinear optics which has the potential to combine these separate functionalities (pulse amplification, frequency transfer, and pulse shaping) into a single monolithic device that is bandwidth- and power-scalable. The approach is based on two-dimensional (2D) patterning of quasi-phase-matching (QPM) gratings combined with optical parametric interactions involving spatially dispersed laser pulses. Our proof of principle experiment demonstrates this technique via mid-infrared optical parametric chirped pulse amplification of few-cycle pulses. Additionally, we present a detailed theoretical and numerical analysis of such 2D-QPM devices and how they can be designed.

Spatially encoded phase-contrast MRI-3D MRI movies of 1D and 2D structures at millisecond resolution.

PubMed

Merboldt, Klaus-Dietmar; Uecker, Martin; Voit, Dirk; Frahm, Jens

2011-10-01

This work demonstrates that the principles underlying phase-contrast MRI may be used to encode spatial rather than flow information along a perpendicular dimension, if this dimension contains an MRI-visible object at only one spatial location. In particular, the situation applies to 3D mapping of curved 2D structures which requires only two projection images with different spatial phase-encoding gradients. These phase-contrast gradients define the field of view and mean spin-density positions of the object in the perpendicular dimension by respective phase differences. When combined with highly undersampled radial fast low angle shot (FLASH) and image reconstruction by regularized nonlinear inversion, spatial phase-contrast MRI allows for dynamic 3D mapping of 2D structures in real time. First examples include 3D MRI movies of the acting human hand at a temporal resolution of 50 ms. With an even simpler technique, 3D maps of curved 1D structures may be obtained from only three acquisitions of a frequency-encoded MRI signal with two perpendicular phase encodings. Here, 3D MRI movies of a rapidly rotating banana were obtained at 5 ms resolution or 200 frames per second. In conclusion, spatial phase-contrast 3D MRI of 2D or 1D structures is respective two or four orders of magnitude faster than conventional 3D MRI. Copyright © 2011 Wiley-Liss, Inc.

Virtual Machine-level Software Transactional Memory: Principles, Techniques, and Implementation

DTIC Science & Technology

2015-08-13

against non-VM STMs, with the same algorithm inside the VM versus “outside”it. Our competitor non-VM STMs include Deuce, ObjectFabric, Multiverse , and...TL2 ByteSTM/NOrec Non-VM/NOrec Deuce/TL2 Object Fabric Multiverse JVSTM (a) 20% writes. (b) 80% writes. Fig. 1 Throughput for Linked-List. Higher is...When Scalability Meets Consistency: Genuine Multiversion Update-Serializable Partial Data Replication. In ICDCS, pages 455–465, 2012. [34] D

Developing a protocol for creating microfluidic devices with a 3D printer, PDMS, and glass

NASA Astrophysics Data System (ADS)

Collette, Robyn; Novak, Eric; Shirk, Kathryn

2015-03-01

Microfluidics research requires the design and fabrication of devices that have the ability to manipulate small volumes of fluid, typically ranging from microliters to picoliters. These devices are used for a wide range of applications including the assembly of materials and testing of biological samples. Many methods have been previously developed to create microfluidic devices, including traditional nanolithography techniques. However, these traditional techniques are cost-prohibitive for many small-scale laboratories. This research explores a relatively low-cost technique using a 3D printed master, which is used as a template for the fabrication of polydimethylsiloxane (PDMS) microfluidic devices. The masters are designed using computer aided design (CAD) software and can be printed and modified relatively quickly. We have developed a protocol for creating simple microfluidic devices using a 3D printer and PDMS adhered to glass. This relatively simple and lower-cost technique can now be scaled to more complicated device designs and applications. Funding provided by the Undergraduate Research Grant Program at Shippensburg University and the Student/Faculty Research Engagement Grants from the College of Arts and Sciences at Shippensburg University.

Depth-diameter ratios for Martian impact craters: Implications for target properties and episodes of degradation

NASA Technical Reports Server (NTRS)

Barlow, N. G.

1993-01-01

This study determines crater depth through use of photoclinometric profiles. Random checks of the photoclinometric results are performed using shadow estimation techniques. The images are Viking Orbiter digital format frames; in cases where the digital image is unusable for photoclinometric analysis, shadow estimation is used to determine crater depths. The two techniques provide depth results within 2 percent of each other. Crater diameters are obtained from the photoclinometric profiles and checked against the diameters measured from the hard-copy images using a digitizer. All images used in this analysis are of approximately 40 m/pixel resolution. The sites that have been analyzed to date include areas within Arabia, Maja Valles, Memnonia, Acidalia, and Elysium. Only results for simple craters (craters less than 5 km in diameter) are discussed here because of the low numbers of complex craters presently measured in the analysis. General results indicate that impact craters are deeper than average. A single d/D relationship for fresh impact craters on Mars does not exist due to changes in target properties across the planet's surface. Within regions where target properties are approximately constant, however, d/D ratios for fresh craters can be determined. In these regions, the d/D ratios of nonpristine craters can be compared with the fresh crater d/D relationship to obtain information on relative degrees of crater degradation. This technique reveals that regional episodes of enhanced degradation have occurred. However, the lack of statistically reliable size-frequency distribution data prevents comparison of the relative ages of these events between different regions, and thus determination of a large-scale episode (or perhaps several episodes) cannot be made at this time.

Has 4D transperineal ultrasound additional value over 2D transperineal ultrasound for diagnosing obstructed defaecation syndrome?

PubMed

van Gruting, I M A; Kluivers, K; Sultan, A H; De Bin, R; Stankiewicz, A; Blake, H; Thakar, R

2018-06-08

To establish the diagnostic test accuracy of both two-dimensional (2D) and four-dimensional (4D) transperineal ultrasound, to assess if 4D ultrasound imaging provides additional value in the diagnosis of posterior pelvic floor disorders in women with obstructed defaecation syndrome. In this prospective cohort study, 121 consecutive women with obstructed defaecation syndrome were recruited. Symptoms of obstructed defaecation and signs of pelvic organ prolapse were assessed using validated methods. All women underwent both 2D transperineal ultrasound (Pro-focus, 8802 transducer, BK-medical) and 4D transperineal ultrasound (Voluson i, RAB4-8-RS transducer, GE). Imaging analysis was performed by two blinded observers. Pelvic floor disorders were dichotomised into presence or absence according pre-defined cut-off values. In the absence of a reference standard a composite reference standard was created from a combination of results of evacuation proctogram, magnetic resonance imaging and endovaginal ultrasound. Primary outcome measures were diagnostic test characteristics of 2D and 4D transperineal ultrasound for diagnosis or rectocele, enterocele, intussusception and anismus. Secondary outcome measures were interobserver agreement, agreement between the two techniques and correlation of signs and symptoms to imaging findings. For diagnosis of all four posterior pelvic floor disorders there was no difference in sensitivity and specificity between 2D and 4D TPUS (p= 0.131 - 1.000). A good agreement between 2D and 4D TPUS was found for the diagnosis of rectocele (ĸ 0.675) and a moderate agreement for diagnosis of enterocele, intussusception and anismus (ĸ 0.465 - 0.545). There was no difference in rectocele depth measurements between both TPUS techniques (19.9 mm vs 19.0 mm, p=0.802). Inter-observer agreement was comparable for both techniques, however 2D TPUS had an excellent interobserver agreement for diagnosis of enterocele and rectocele depth measurements. Diagnosis of rectocele and enterocele on both 2D and 4D TPUS correlated well with presence of posterior vaginal wall prolapse on clinical examination (OR 1.89 - 2.72). In this group of ODS patients, the imaging findings on both techniques did not correlate with severity of symptoms of ODS (OR 0.82 - 1.08). There is no evidence of a superiority of 4D ultrasound acquisition to dynamic 2D ultrasound acquisition for the diagnosis of posterior pelvic floor disorders. Both 2D and 4D TPUS could be used interchangeably to screen women with symptoms of obstructed defaecation. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Isolation, chemical characterization, and free radical scavenging activity of phenolics from Triticum aestivum L. aerial parts.

PubMed

Kowalska, Iwona; Pecio, Lukasz; Ciesla, Lukasz; Oleszek, Wieslaw; Stochmal, Anna

2014-11-19

Fourteen phenolic compounds (flavonoids and phenolic acids) were isolated and 19 were identified in the aerial parts of Triticum aestivum L. The structures of these compounds were established on the basis of the data obtained by electrospray ionization-mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR) techniques. T. aestivum L. was found to be rich in flavones, especially in luteolin derivatives. Three of the isolated compounds, including luteolin 6-C-[6Glc″-O-E-caffeoyl-β-D-glucopyranosyl(1″→2)-β-glucopyranoside], luteolin 6-C-[5Rib″-O-E-feruoyl-β-D-ribofuranosyl(1″→2)-β-glucopyranoside], and 3',4',5'-O-trimethyltricetin 7-O-[β-D-glucuropyranosyl(1″→2)-β-D-glucopyranoside], have been reported for the first time in the plant kingdom. The amount of individual phenolics, in winter wheat, was also determined. Additionally, the free radical scavenging potential of the isolated compounds was tested in a simple and rapid thin-layer chromatography-2,2-diphenyl-1-picrylhydrazyl radical test (TLC-DPPH•) with image processing.

Three-dimensional photography for the evaluation of facial profiles in obstructive sleep apnoea.

PubMed

Lin, Shih-Wei; Sutherland, Kate; Liao, Yu-Fang; Cistulli, Peter A; Chuang, Li-Pang; Chou, Yu-Ting; Chang, Chih-Hao; Lee, Chung-Shu; Li, Li-Fu; Chen, Ning-Hung

2018-06-01

Craniofacial structure is an important determinant of obstructive sleep apnoea (OSA) syndrome risk. Three-dimensional stereo-photogrammetry (3dMD) is a novel technique which allows quantification of the craniofacial profile. This study compares the facial images of OSA patients captured by 3dMD to three-dimensional computed tomography (3-D CT) and two-dimensional (2-D) digital photogrammetry. Measurements were correlated with indices of OSA severity. Thirty-eight patients diagnosed with OSA were included, and digital photogrammetry, 3dMD and 3-D CT were performed. Distances, areas, angles and volumes from the images captured by three methods were analysed. Almost all measurements captured by 3dMD showed strong agreement with 3-D CT measurements. Results from 2-D digital photogrammetry showed poor agreement with 3-D CT. Mandibular width, neck perimeter size and maxillary volume measurements correlated well with the severity of OSA using all three imaging methods. Mandibular length, facial width, binocular width, neck width, cranial base triangle area, cranial base area 1 and middle cranial fossa volume correlated well with OSA severity using 3dMD and 3-D CT, but not with 2-D digital photogrammetry. 3dMD provided accurate craniofacial measurements of OSA patients, which were highly concordant with those obtained by CT, while avoiding the radiation associated with CT. © 2018 Asian Pacific Society of Respirology.

SU-F-BRB-13: Correlation of Improved Target and Organ-At-Risk Dosimetric Quantities and Clinical Outcomes for Helical Tomotherapy Treated Mesothelioma

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

Qi, S; Kishan, A; Alexander, S

2015-06-15

Purpose: We have observed improved local control probability (LCP) for adjuvant mesothelioma radiotherapy following pleurectomy/decortication using Tomotherapy compared to the conventional 3D technique (p<0.05). This work assesses the correlation between the improved clinical outcomes against dosimetry quantities. Methods: Thirty-eight mesothelioma cases consecutively treated at our clinic were retrospectively analyzed. Sixteen patients were treated using 3D technique planned on the Eclipse for c-arm accelerators prior to 7/2012; the other 22 cases were treated on Tomotherapy using helical IMRT after 7/2012. Typical 3D plans consisting of 15 MV AP/PA photon fields prescribed to 10 cm depth followed by matching electron fields withmore » energy ranging from 8–16 MeV. Tomotherapy plans were designed using 2.5cm jaw, 0.287 pitch with directional blocking of the contralateral lung. The same prescription of 45 Gy (1.8GyX25) was used for both techniques. The dosimetry metrics for the critical structures: ipsilateral-/contralateral-lung, heart, cord, esophagus, etc were compared between two techniques. Results: Superior LCP is closely associated with improved target coverage. Tomotherapy plans yielded dramatically better target coverage and less dose heterogeneity despite of more advanced/larger disease. The averaged PTV volumes were 2287.3±569.9 (Tomotherapy) vs. 1904.8±312.3cc (3D); V100s were: 91.1±4.0 (%) vs. 47.8±12.7 (%) with heterogeneity indices of 1.20±0.1 vs.1.37±0.38 and for the Tomotherapy and 3D plans, respectively. Compared to the 3D technique, we observed significant lower maximum cord doses (p<0.001), lower mean esophagus doses (p<0.002), and lower heart mean doses when tumor was left-sided (p=0.002). For ipsilateral-/contralateral-lungs, however, the mean doses and V20, V5 of Tomotherapy plans were significantly higher than the 3D plans (p<0.01) regardless which sides of lung were treated. However, rates of radiation pneumonitis were no different. Conclusion: Tomotherapy achieved great improvement of plan quality including target coverage, resulting in significantly better local control over the traditional 3D technique for adjuvant radiotherapy for mesothelioma.« less

Structural modification of unilamellar and multilamellar vesicles in the presence of vitamin D

NASA Astrophysics Data System (ADS)

Devarajan, A.; Raouf, Y. A.; Rashid, S.; Law, R. L.; Stojanoff, V.; Isakovic, A. F.; Gater, D. L.

Chronic vitamin D deficiency is increasingly associated with a range of health conditions, such as cardiovascular disease, diabetes and certain cancers. Our report contributes to a mechanistic understanding of these associations. Vitamin D is a lipophilic compound that is synthesized in the skin by the action of UV light on 7-dehydrocholesterol and obtained from dietary sources. We look at how vitamin D could be extracted from either skin membranes or therapeutic liposomes and transported through the body by its associated proteins. A variety of physical techniques (FTIR, DLS, UV-Vis spectroscopy, NMR, XRD) are brought to investigate: (a) the behavior of vitamin D in model membranes, and (b) the effect of vitamin D-associated proteins on membrane structure. Our results include: (1) vitamin D can be incorporated into DOPC membranes up to 40mol% with only minor changes in the dynamics of the lipid acyl chains; (2) liposomes containing larger quantities of vitamin D may have reduced stability over time; (3) the vitamin D binding protein and the vitamin D receptor do associate with and alter the behavior of model membranes, including systems that do not contain vitamin D. We acknowledge the support from KU-KAIST collaborative Grant program, and support from BNL staff.

CT-image-based conformal brachytherapy of breast cancer. The significance of semi-3-D and 3-D treatment planning.

PubMed

Polgár, C; Major, T; Somogyi, A; Takácsi-Nagy, Z; Mangel, L C; Forrai, G; Sulyok, Z; Fodor, J; Németh, G

2000-03-01

To compare the conventional 2-D, the simulator-guided semi-3-D and the recently developed CT-guided 3-D brachytherapy treatment planning in the interstitial radiotherapy of breast cancer. In 103 patients with T1-2, N0-1 breast cancer the tumor bed was clipped during breast conserving surgery. Fifty-two of them received boost brachytherapy after 46 to 50 Gy teletherapy and 51 patients were treated with brachytherapy alone via flexible implant tubes. Single, double and triple plane implant was used in 6, 89 and 8 cases, respectively. The dose of boost brachytherapy and sole brachytherapy prescribed to dose reference points was 3 times 4.75 Gy and 7 times 5.2 Gy, respectively. The positions of dose reference points varied according to the level (2-D, semi-3-D and 3-D) of treatment planning performed. The treatment planning was based on the 3-D reconstruction of the surgical clips, implant tubes and skin points. In all cases the implantations were planned with a semi-3-D technique aided by simulator. In 10 cases a recently developed CT-guided 3-D planning system was used. The semi-3-D and 3-D treatment plans were compared to hypothetical 2-D plans using dose-volume histograms and dose non-uniformity ratios. The values of mean central dose, mean skin dose, minimal clip dose, proportion of underdosaged clips and mean target surface dose were evaluated. The accuracy of tumor bed localization and the conformity of planning target volume and treated volume were also analyzed in each technique. With the help of conformal semi-3-D and 3-D brachytherapy planning we could define reference dose points, active source positions and dwell times individually. This technique decreased the mean skin dose with 22.2% and reduced the possibility of geographical miss. We could achieve the best conformity between the planning target volume and the treated volume with the CT-image based 3-D treatment planning, at the cost of worse dose homogeneity. The mean treated volume was reduced by 25.1% with semi-3-D planning, however, it was increased by 16.2% with 3-D planning, compared to the 2-D planning. The application of clips into the tumor bed and the conformal (semi-3-D and 3-D) planning help to avoid geographical miss. CT is suitable for 3-D brachytherapy planning. Better local control with less side effects might be achieved with these new techniques. Conformal 3-D brachytherapy calls for new treatment planning concepts, taking the irregular 3-D shape of the target volume into account. The routine clinical application of image-based 3-D brachytherapy is a real aim in the very close future.

Adaptive wall technology for minimization of wall interferences in transonic wind tunnels

NASA Technical Reports Server (NTRS)

Wolf, Stephen W. D.

1988-01-01

Modern experimental techniques to improve free air simulations in transonic wind tunnels by use of adaptive wall technology are reviewed. Considered are the significant advantages of adaptive wall testing techniques with respect to wall interferences, Reynolds number, tunnel drive power, and flow quality. The application of these testing techniques relies on making the test section boundaries adjustable and using a rapid wall adjustment procedure. A historical overview shows how the disjointed development of these testing techniques, since 1938, is closely linked to available computer support. An overview of Adaptive Wall Test Section (AWTS) designs shows a preference for use of relatively simple designs with solid adaptive walls in 2- and 3-D testing. Operational aspects of AWTS's are discussed with regard to production type operation where adaptive wall adjustments need to be quick. Both 2- and 3-D data are presented to illustrate the quality of AWTS data over the transonic speed range. Adaptive wall technology is available for general use in 2-D testing, even in cryogenic wind tunnels. In 3-D testing, more refinement of the adaptive wall testing techniques is required before more widespread use can be planned.

Successful mouse cloning of an outbred strain by trichostatin A treatment after somatic nuclear transfer.

PubMed

Kishigami, Satoshi; Bui, Hong-Thuy; Wakayama, Sayaka; Tokunaga, Kenzo; Van Thuan, Nguyen; Hikichi, Takafusa; Mizutani, Eiji; Ohta, Hiroshi; Suetsugu, Rinako; Sata, Tetsutaro; Wakayama, Teruhiko

2007-02-01

Although the somatic cloning technique has been used for numerous applications and basic research of reprogramming in various species, extremely low success rates have plagued this technique for a decade. Further in mice, the "clonable" strains have been limited to mainly hybrid F1 strains such as B6D2F1. Recently, we established a new efficient cloning technique using trichostatin A (TSA) which leads to a 2-5 fold increase in success rates for mouse cloning of B6D2F1 cumulus cells. To further test the validity of this TSA cloning technique, we tried to clone the adult ICR mouse, an outbred strain, which has never been directly cloned before. Only when TSA was used did we obtain both male and female cloned mice from cumulus and fibroblast cells of adult ICR mice with 4-5% success rates, which is comparable to 5-7% of B6D2F1. Thus, the TSA treatment is the first cloning technique to allow us to successfully clone outbred mice, demonstrating that this technique not only improves the success rates of cloning from hybrid strains, but also enables mouse cloning from normally "unclonable" strains.

New cytotoxic and anti-inflammatory compounds isolated from Morus alba L.

PubMed

Qin, Jing; Fan, Min; He, Juan; Wu, Xing-De; Peng, Li-Yan; Su, Jia; Cheng, Xiao; Li, Yan; Kong, Ling-Mei; Li, Rong-Tao; Zhao, Qin-Shi

2015-01-01

Six Diels-Alder adducts (1-6) and nine prenylated flavanones (7-15) were isolated from the root bark of Morus alba L. Among them, soroceal B (1) and sanggenol Q (7) were new compounds. Their structures were elucidated on the basis of extensive spectroscopic methods, including 1D and 2D NMR techniques. Compounds 1-3, 9, 10, 12, 13 and 15 exhibited cytotoxic activity against five human tumour lines and compound 2 inhibited significantly selective cytotoxic activities towards HL-60 and AGS cells with IC50 of 3.4 and 3.6 μM. Compounds 3, 5, 9 and 12 exhibited moderate inhibitory activity against nitric oxide production in LPS-activated RAW264.7.

Interaction Between a Steady Detonation Wave in Nitromethane and Geometrical Complex Confinement Defects

NASA Astrophysics Data System (ADS)

Crouzet, B.; Soulard, L.; Carion, N.; Manczur, P.

2007-12-01

Two copper cylinder expansion tests were carried out on nitromethane. They differ from the classical cylinder test in that the liner includes evenly-spaced protruding circular defects. The aim is to study how a detonation front propagating in the liquid explosive interacts with the confining material defects. The subsequent motion of the metal, accelerated by the expanding detonation products, is measured using a range of diagnostic techniques: electrical probes, a rapid framing camera, a glass block associated with a streak camera and velocity laser interferometers. The different experimental records have been examined in the light of previous classical cylinder test measurements, simple 2D theoretical shock polar analysis results and 2D numerical simulations.

Canard configured aircraft with 2-D nozzle

NASA Technical Reports Server (NTRS)

Child, R. D.; Henderson, W. P.

1978-01-01

A closely-coupled canard fighter with vectorable two-dimensional nozzle was designed for enhanced transonic maneuvering. The HiMAT maneuver goal of a sustained 8g turn at a free-stream Mach number of 0.9 and 30,000 feet was the primary design consideration. The aerodynamic design process was initiated with a linear theory optimization minimizing the zero percent suction drag including jet effects and refined with three-dimensional nonlinear potential flow techniques. Allowances were made for mutual interference and viscous effects. The design process to arrive at the resultant configuration is described, and the design of a powered 2-D nozzle model to be tested in the LRC 16-foot Propulsion Wind Tunnel is shown.

Focus: Two-dimensional electron-electron double resonance and molecular motions: The challenge of higher frequencies.

PubMed

Franck, John M; Chandrasekaran, Siddarth; Dzikovski, Boris; Dunnam, Curt R; Freed, Jack H

2015-06-07

The development, applications, and current challenges of the pulsed ESR technique of two-dimensional Electron-Electron Double Resonance (2D ELDOR) are described. This is a three-pulse technique akin to 2D Exchange Nuclear Magnetic Resonance, but involving electron spins, usually in the form of spin-probes or spin-labels. As a result, it required the extension to much higher frequencies, i.e., microwaves, and much faster time scales, with π/2 pulses in the 2-3 ns range. It has proven very useful for studying molecular dynamics in complex fluids, and spectral results can be explained by fitting theoretical models (also described) that provide a detailed analysis of the molecular dynamics and structure. We discuss concepts that also appear in other forms of 2D spectroscopy but emphasize the unique advantages and difficulties that are intrinsic to ESR. Advantages include the ability to tune the resonance frequency, in order to probe different motional ranges, while challenges include the high ratio of the detection dead time vs. the relaxation times. We review several important 2D ELDOR studies of molecular dynamics. (1) The results from a spin probe dissolved in a liquid crystal are followed throughout the isotropic → nematic → liquid-like smectic → solid-like smectic → crystalline phases as the temperature is reduced and are interpreted in terms of the slowly relaxing local structure model. Here, the labeled molecule is undergoing overall motion in the macroscopically aligned sample, as well as responding to local site fluctuations. (2) Several examples involving model phospholipid membranes are provided, including the dynamic structural characterization of the boundary lipid that coats a transmembrane peptide dimer. Additionally, subtle differences can be elicited for the phospholipid membrane phases: liquid disordered, liquid ordered, and gel, and the subtle effects upon the membrane, of antigen cross-linking of receptors on the surface of plasma membrane, vesicles can be observed. These 2D ELDOR experiments are performed as a function of mixing time, Tm, i.e., the time between the second and third π/2 pulses, which provides a third dimension. In fact, a fourth dimension may be added by varying the ESR frequency/magnetic field combination. Therefore, (3) it is shown how continuous-wave multifrequency ESR studies enable the decomposition of complex dynamics of, e.g., proteins by virtue of their respective time scales. These studies motivate our current efforts that are directed to extend 2D ELDOR to higher frequencies, 95 GHz in particular (from 9 and 17 GHz), in order to enable multi-frequency 2D ELDOR. This required the development of quasi-optical methods for performing the mm-wave experiments, which are summarized. We demonstrate state-of-the-art 95 GHz 2D ELDOR spectroscopy through its ability to resolve the two signals from a spin probe dissolved in both the lipid phase and the coexisting aqueous phase. As current 95 GHz experiments are restricted by limited spectral coverage of the π/2 pulse, as well as the very short T2 relaxation times of the electron spins, we discuss how these limitations are being addressed.

Focus: Two-dimensional electron-electron double resonance and molecular motions: The challenge of higher frequencies

NASA Astrophysics Data System (ADS)

Franck, John M.; Chandrasekaran, Siddarth; Dzikovski, Boris; Dunnam, Curt R.; Freed, Jack H.

2015-06-01

The development, applications, and current challenges of the pulsed ESR technique of two-dimensional Electron-Electron Double Resonance (2D ELDOR) are described. This is a three-pulse technique akin to 2D Exchange Nuclear Magnetic Resonance, but involving electron spins, usually in the form of spin-probes or spin-labels. As a result, it required the extension to much higher frequencies, i.e., microwaves, and much faster time scales, with π/2 pulses in the 2-3 ns range. It has proven very useful for studying molecular dynamics in complex fluids, and spectral results can be explained by fitting theoretical models (also described) that provide a detailed analysis of the molecular dynamics and structure. We discuss concepts that also appear in other forms of 2D spectroscopy but emphasize the unique advantages and difficulties that are intrinsic to ESR. Advantages include the ability to tune the resonance frequency, in order to probe different motional ranges, while challenges include the high ratio of the detection dead time vs. the relaxation times. We review several important 2D ELDOR studies of molecular dynamics. (1) The results from a spin probe dissolved in a liquid crystal are followed throughout the isotropic → nematic → liquid-like smectic → solid-like smectic → crystalline phases as the temperature is reduced and are interpreted in terms of the slowly relaxing local structure model. Here, the labeled molecule is undergoing overall motion in the macroscopically aligned sample, as well as responding to local site fluctuations. (2) Several examples involving model phospholipid membranes are provided, including the dynamic structural characterization of the boundary lipid that coats a transmembrane peptide dimer. Additionally, subtle differences can be elicited for the phospholipid membrane phases: liquid disordered, liquid ordered, and gel, and the subtle effects upon the membrane, of antigen cross-linking of receptors on the surface of plasma membrane, vesicles can be observed. These 2D ELDOR experiments are performed as a function of mixing time, Tm, i.e., the time between the second and third π/2 pulses, which provides a third dimension. In fact, a fourth dimension may be added by varying the ESR frequency/magnetic field combination. Therefore, (3) it is shown how continuous-wave multifrequency ESR studies enable the decomposition of complex dynamics of, e.g., proteins by virtue of their respective time scales. These studies motivate our current efforts that are directed to extend 2D ELDOR to higher frequencies, 95 GHz in particular (from 9 and 17 GHz), in order to enable multi-frequency 2D ELDOR. This required the development of quasi-optical methods for performing the mm-wave experiments, which are summarized. We demonstrate state-of-the-art 95 GHz 2D ELDOR spectroscopy through its ability to resolve the two signals from a spin probe dissolved in both the lipid phase and the coexisting aqueous phase. As current 95 GHz experiments are restricted by limited spectral coverage of the π/2 pulse, as well as the very short T2 relaxation times of the electron spins, we discuss how these limitations are being addressed.

Polyphenolic compounds with antioxidant potential and neuro-protective effect from Cimicifuga dahurica (Turcz.) Maxim.

PubMed

Qin, Rulan; Zhao, Ying; Zhao, Yudan; Zhou, Wanrong; Lv, Chongning; Lu, Jincai

2016-12-01

Three new phenolic compounds (1-3), along with five known compounds (4-8) were isolated from the rhizome of Cimicifuga dahurica (Turcz.) Maxim. Their structures were elucidated by spectroscopic methods including 1D-NMR, 2D-NMR and HR-MS techniques. DPPH method and protective effect on PC12 cells against H 2 O 2 -induced oxidative damage model were carried to evaluate the antioxidant capability of these compounds. Compound 5 showed significant antioxidant activity with IC 50 values 9.33μM in DPPH assay and compound 2 displayed marked neuro-protective effect with 87.65% cell viability at the concentration of 10μM. Additionally, the possible structure-activity relationships of these phenolic compounds were tentatively discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

Evaluation of the Communication Between Arachnoid Cysts and Neighboring Cerebrospinal Fluid Spaces by T2W 3D-SPACE With Variant Flip-Angle Technique at 3 T.

PubMed

Algin, Oktay

2018-05-21

Phase-contrast cine magnetic resonance imaging (PC-MRI) is a widely used technique for determination of possible communication of arachnoid cysts (ACs). Three-dimensional (3D) sampling perfection with application-optimized contrasts using different flip-angle evolutions (3D-SPACE) technique is a relatively new method for 3D isotropic scanning of the entire cranium within a short time. In this research, the usage of the 3D-SPACE technique in differentiation of communicating or noncommunicating type ACs was evaluated. Thirty-five ACs in 34 patients were retrospectively examined. The 3D-SPACE, PC-MRI, and contrast material-enhanced cisternography (if present) images of the patients were analyzed. Each cyst was described according to cyst size/location, third ventricle diameter, Evans index, and presence of hydrocephalus. Communication was defined as absent (score 0), suspected (score 1), or present (score 2) on each sequence. Results of PC-MRI or cisternography (if available) examinations were used as criterion standard techniques to categorize all cysts as communicating or noncommunicating type. The results of 3D-SPACE were compared with criterion standard techniques. The comparisons between groups were performed using Mann-Whitney and Fisher exact tests. For demonstration of communication status of the cysts, criterion standard test results and 3D-SPACE findings were almost in perfect harmony (κ[95% confidence interval: 0.94]; P < 0.001). When evaluating the communicative properties, 3D-SPACE findings correlated with other final results at a rate of 97%. There is a positive correlation with third ventricular diameters and Evans index for all patients (r = 0.77, P < 0.001). For other analyzed variables, there is no significant difference or correlation between the groups. The 3D-SPACE technique is an easy, useful, and noninvasive alternative for the evaluation of morphology, topographical relationships, and communication status of ACs.

Stainless Steel Crown Placement Utilizing the Hall Technique

DTIC Science & Technology

2017-03-23

Technique presented at/published to HINMAN Dental Society, 33 Lenox Pointe NE, Atlanta, GA, 23-25 March 2017 in accordance with MDWI 41-108, has...DISAPPROVED D N/A Academic presentation on dental techniques using publicly avai lable in format ion. A ppropriate disclaim ers included. Approved 28

Techniques for the rapid display and manipulation of 3-D biomedical data.

PubMed

Goldwasser, S M; Reynolds, R A; Talton, D A; Walsh, E S

1988-01-01

The use of fully interactive 3-D workstations with true real-time performance will become increasingly common as technology matures and economical commercial systems become available. This paper provides a comprehensive introduction to high speed approaches to the display and manipulation of 3-D medical objects obtained from tomographic data acquisition systems such as CT, MR, and PET. A variety of techniques are outlined including the use of software on conventional minicomputers, hardware assist devices such as array processors and programmable frame buffers, and special purpose computer architecture for dedicated high performance systems. While both algorithms and architectures are addressed, the major theme centers around the utilization of hardware-based approaches including parallel processors for the implementation of true real-time systems.

Estimation of liver T₂ in transfusion-related iron overload in patients with weighted least squares T₂ IDEAL.

PubMed

Vasanawala, Shreyas S; Yu, Huanzhou; Shimakawa, Ann; Jeng, Michael; Brittain, Jean H

2012-01-01

MRI imaging of hepatic iron overload can be achieved by estimating T(2) values using multiple-echo sequences. The purpose of this work is to develop and clinically evaluate a weighted least squares algorithm based on T(2) Iterative Decomposition of water and fat with Echo Asymmetry and Least-squares estimation (IDEAL) technique for volumetric estimation of hepatic T(2) in the setting of iron overload. The weighted least squares T(2) IDEAL technique improves T(2) estimation by automatically decreasing the impact of later, noise-dominated echoes. The technique was evaluated in 37 patients with iron overload. Each patient underwent (i) a standard 2D multiple-echo gradient echo sequence for T(2) assessment with nonlinear exponential fitting, and (ii) a 3D T(2) IDEAL technique, with and without a weighted least squares fit. Regression and Bland-Altman analysis demonstrated strong correlation between conventional 2D and T(2) IDEAL estimation. In cases of severe iron overload, T(2) IDEAL without weighted least squares reconstruction resulted in a relative overestimation of T(2) compared with weighted least squares. Copyright © 2011 Wiley-Liss, Inc.

Hierarchically 3D assembled strontium titanate nanomaterials for water splitting application

NASA Astrophysics Data System (ADS)

Moniruddin, Md; Afroz, Khurshida; Shabdan, Yerkin; Bizri, Baraa; Nuraje, Nurxat

2017-10-01

Water splitting is an important technique to store solar energy in the simple form of chemical energy, such as hydrogen. Strontium titanate (SrTiO3) is one of the most promising photocatalysts to produce hydrogen gas from water splitting. In this research, an electrospinning technique in combination with sol-gel method was developed to synthesize 3D porous SrTiO3 nanostructures. Different crystallite sizes of SrTiO3-nanofibers (STO-NFs) were produced by varying the synthesis parameters including precursor concentration and calcination temperature. The synthesized nanofibers were characterized using DSC, TGA, XRD, SEM, and TEM. The crystallite size of STO-NFs decreases with increasing precursor concentration (3.03-15.78 vol.%) and gradually increases as the calcination temperature increases within the range of 600-800 °C. The photocatalytic activity of different STO-NFs (based on crystallite size) was also evaluated by the amount of H2 production from water splitting under UV irradiation. The H2 evolution study demonstrated that the photocatalytic activity of the STO-NFs strongly depends on the crystallite size of the nanofibers, precursor concentration, and calcination temperature. The H2 production rate increases with increasing crystallite size and temperature, whereas it decreases with increasing precursor concentration. The photocatalytic performance of the STO-NFs was also compared with the commercial SrTiO3 nanoparticles (STO-NPs) after Pt addition as a cocatalyst, where the synthesized nanofibers showed 2 times higher H2 production rate (1.14 mmol/g-h) than that of the nanoparticles. This synthesis technique provides a good example to produce other inorganic photocatalytic 3D porous structure materials.

SU-F-J-158: Respiratory Motion Resolved, Self-Gated 4D-MRI Using Rotating Cartesian K-Space Sampling

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

Han, F; Zhou, Z; Yang, Y

Purpose: Dynamic MRI has been used to quantify respiratory motion of abdominal organs in radiation treatment planning. Many existing 4D-MRI methods based on 2D acquisitions suffer from limited slice resolution and additional stitching artifacts when evaluated in 3D{sup 1}. To address these issues, we developed a 4D-MRI (3D dynamic) technique with true 3D k-space encoding and respiratory motion self-gating. Methods: The 3D k-space was acquired using a Rotating Cartesian K-space (ROCK) pattern, where the Cartesian grid was reordered in a quasi-spiral fashion with each spiral arm rotated using golden angle{sup 2}. Each quasi-spiral arm started with the k-space center-line, whichmore » were used as self-gating{sup 3} signal for respiratory motion estimation. The acquired k-space data was then binned into 8 respiratory phases and the golden angle ensures a near-uniform k-space sampling in each phase. Finally, dynamic 3D images were reconstructed using the ESPIRiT technique{sup 4}. 4D-MRI was performed on 6 healthy volunteers, using the following parameters (bSSFP, Fat-Sat, TE/TR=2ms/4ms, matrix size=500×350×120, resolution=1×1×1.2mm, TA=5min, 8 respiratory phases). Supplemental 2D real-time images were acquired in 9 different planes. Dynamic locations of the diaphragm dome and left kidney were measured from both 4D and 2D images. The same protocol was also performed on a MRI-compatible motion phantom where the motion was programmed with different amplitude (10–30mm) and frequency (3–10/min). Results: High resolution 4D-MRI were obtained successfully in 5 minutes. Quantitative motion measurements from 4D-MRI agree with the ones from 2D CINE (<5% error). The 4D images are free of the stitching artifacts and their near-isotropic resolution facilitates 3D visualization and segmentation of abdominal organs such as the liver, kidney and pancreas. Conclusion: Our preliminary studies demonstrated a novel ROCK 4D-MRI technique with true 3D k-space encoding and respiratory motion self-gating. The technique leads to high-resolution and artifacts-free 4D images for improved abdominal organ motion studies. K.S acknowledges funding support from NIH R01CA188300.« less

Development of scanning holographic display using MEMS SLM

NASA Astrophysics Data System (ADS)

Takaki, Yasuhiro

2016-10-01

Holography is an ideal three-dimensional (3D) display technique, because it produces 3D images that naturally satisfy human 3D perception including physiological and psychological factors. However, its electronic implementation is quite challenging because ultra-high resolution is required for display devices to provide sufficient screen size and viewing zone. We have developed holographic display techniques to enlarge the screen size and the viewing zone by use of microelectromechanical systems spatial light modulators (MEMS-SLMs). Because MEMS-SLMs can generate hologram patterns at a high frame rate, the time-multiplexing technique is utilized to virtually increase the resolution. Three kinds of scanning systems have been combined with MEMS-SLMs; the screen scanning system, the viewing-zone scanning system, and the 360-degree scanning system. The screen scanning system reduces the hologram size to enlarge the viewing zone and the reduced hologram patterns are scanned on the screen to increase the screen size: the color display system with a screen size of 6.2 in. and a viewing zone angle of 11° was demonstrated. The viewing-zone scanning system increases the screen size and the reduced viewing zone is scanned to enlarge the viewing zone: a screen size of 2.0 in. and a viewing zone angle of 40° were achieved. The two-channel system increased the screen size to 7.4 in. The 360-degree scanning increases the screen size and the reduced viewing zone is scanned circularly: the display system having a flat screen with a diameter of 100 mm was demonstrated, which generates 3D images viewed from any direction around the flat screen.

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

Guy, Jean-Baptiste; Falk, Alexander T.; Auberdiac, Pierre

Introduction: For patients with cervical cancer, intensity-modulated radiation therapy (IMRT) improves target coverage and allows dose escalation while reducing the radiation dose to organs at risk (OARs). In this study, we compared dosimetric parameters among 3-dimensional conformal radiotherapy (3D-CRT), “step-and-shoot” IMRT, and volumetric intensity-modulated arc radiotherapy (VMAT) in a series of patients with cervical cancer receiving definitive radiotherapy. Computed tomography (CT) scans of 10 patients with histologically proven cervical cancer treated with definitive radiation therapy (RT) from December 2008 to March 2010 at our department were selected for this study. The gross tumor volume (GTV) and clinical target volume (CTV)more » were delineated following the guidelines of the Gyn IMRT consortium that included cervix, uterus, parametrial tissues, and the pelvic nodes including presacral. The median age was 57 years (range: 30 to 85 years). All 10 patients had squamous cell carcinoma with Federation of Gynecology and Obstetrics (FIGO) stage IB-IIIB. All patients were treated by VMAT. OAR doses were significantly reduced for plans with intensity-modulated technique compared with 3D-CRT except for the dose to the vagina. Between the 2 intensity-modulated techniques, significant difference was observed for the mean dose to the small intestine, to the benefit of VMAT (p < 0.001). There was no improvement in terms of OARs sparing for VMAT although there was a tendency for a slightly decreased average dose to the rectum: − 0.65 Gy but not significant (p = 0.07). The intensity modulation techniques have many advantages in terms of quality indexes, and particularly OAR sparing, compared with 3D-CRT. Following the ongoing technologic developments in modern radiotherapy, it is essential to evaluate the intensity-modulated techniques on prospective studies of a larger scale.« less

ARRA-funded VS30 measurements using multi-technique approach at strong-motion stations in California and central-eastern United States

USGS Publications Warehouse

Yong, Alan; Martin, Antony; Stokoe, Kenneth; Diehl, John

2013-01-01

Funded by the 2009 American Recovery and Reinvestment Act (ARRA), we conducted geophysical site characterizations at 191 strong-motion stations: 187 in California and 4 in the Central-Eastern United States (CEUS). The geophysical methods used at each site included passive and active surface-wave and body-wave techniques. Multiple techniques were used at most sites, with the goal of robustly determining VS (shear-wave velocity) profiles and VS30 (the time-averaged shear-wave velocity in the upper 30 meters depth). These techniques included: horizontal-to-vertical spectral ratio (HVSR), two-dimensional (2-D) array microtremor (AM), refraction microtremor (ReMi™), spectral analysis of surface wave (SASW), multi-channel analysis of surface waves (Rayleigh wave: MASRW; and Love wave: MASLW), and compressional- and shear-wave refraction. Of the selected sites, 47 percent have crystalline, volcanic, or sedimentary rock at the surface or at relatively shallow depth, and 53 percent are of Quaternary sediments located in either rural or urban environments. Calculated values of VS30 span almost the full range of the National Earthquake Hazards Reduction Program (NEHRP) Site Classes, from D (stiff soils) to B (rock). The NEHRP Site Classes based on VS30 range from being consistent with the Class expected from analysis of surficial geology, to being one or two Site Classes below expected. In a few cases where differences between the observed and expected Site Class occurred, it was the consequence of inaccurate or coarse geologic mapping, as well as considerable degradation of the near-surface rock. Additionally, several sites mapped as rock have Site Class D (stiff soil) velocities, which is due to the extensive weathering of the surficial rock.

Four-dimensional diffusion-weighted MR imaging (4D-DWI): a feasibility study.

PubMed

Liu, Yilin; Zhong, Xiaodong; Czito, Brian G; Palta, Manisha; Bashir, Mustafa R; Dale, Brian M; Yin, Fang-Fang; Cai, Jing

2017-02-01

Diffusion-weighted Magnetic Resonance Imaging (DWI) has been shown to be a powerful tool for cancer detection with high tumor-to-tissue contrast. This study aims to investigate the feasibility of developing a four-dimensional DWI technique (4D-DWI) for imaging respiratory motion for radiation therapy applications. Image acquisition was performed by repeatedly imaging a volume of interest (VOI) using an interleaved multislice single-shot echo-planar imaging (EPI) 2D-DWI sequence in the axial plane. Each 2D-DWI image was acquired with an intermediately low b-value (b = 500 s/mm 2 ) and with diffusion-encoding gradients in x, y, and z diffusion directions. Respiratory motion was simultaneously recorded using a respiratory bellow, and the synchronized respiratory signal was used to retrospectively sort the 2D images to generate 4D-DWI. Cine MRI using steady-state free precession was also acquired as a motion reference. As a preliminary feasibility study, this technique was implemented on a 4D digital human phantom (XCAT) with a simulated pancreas tumor. The respiratory motion of the phantom was controlled by regular sinusoidal motion profile. 4D-DWI tumor motion trajectories were extracted and compared with the input breathing curve. The mean absolute amplitude differences (D) were calculated in superior-inferior (SI) direction and anterior-posterior (AP) direction. The technique was then evaluated on two healthy volunteers. Finally, the effects of 4D-DWI on apparent diffusion coefficient (ADC) measurements were investigated for hypothetical heterogeneous tumors via simulations. Tumor trajectories extracted from XCAT 4D-DWI were consistent with the input signal: the average D value was 1.9 mm (SI) and 0.4 mm (AP). The average D value was 2.6 mm (SI) and 1.7 mm (AP) for the two healthy volunteers. A 4D-DWI technique has been developed and evaluated on digital phantom and human subjects. 4D-DWI can lead to more accurate respiratory motion measurement. This has a great potential to improve the visualization and delineation of cancer tumors for radiotherapy. © 2016 American Association of Physicists in Medicine.

Novel RF and microwave components employing ferroelectric and solid-state tunable capacitors for multi-functional wireless communication systems

NASA Astrophysics Data System (ADS)

Tombak, Ali

The recent advancement in wireless communications demands an ever increasing improvement in the system performance and functionality with a reduced size and cost. This thesis demonstrates novel RF and microwave components based on ferroelectric and solid-state based tunable capacitor (varactor) technologies for the design of low-cost, small-size and multi-functional wireless communication systems. These include tunable lumped element VHF filters based on ferroelectric varactors, a beam-steering technique which, unlike conventional systems, does not require separate power divider and phase shifters, and a predistortion linearization technique that uses a varactor based tunable R-L-C resonator. Among various ferroelectric materials, Barium Strontium Titanate (BST) is actively being studied for the fabrication of high performance varactors at RF and microwave frequencies. BST based tunable capacitors are presented with typical tunabilities of 4.2:1 with the application of 5 to 10 V DC bias voltages and typical loss tangents in the range of 0.003--0.009 at VHF frequencies. Tunable lumped element lowpass and bandpass VHF filters based on BST varactors are also demonstrated with tunabilities of 40% and 57%, respectively. A new beam-steering technique is developed based on the extended resonance power dividing technique. Phased arrays based on this technique do not require separate power divider and phase shifters. Instead, the power division and phase shifting circuits are combined into a single circuit, which utilizes tunable capacitors. This results in a substantial reduction in the circuit complexity and cost. Phased arrays based on this technique can be employed in mobile multimedia services and automotive collision avoidance radars. A 2-GHz 4-antenna and a 10-GHz 8-antenna extended resonance phased arrays are demonstrated with scan ranges of 20 degrees and 18 degrees, respectively. A new predistortion linearization technique for the linearization of RF/microwave power amplifiers is also presented. This technique utilizes a varactor based tunable R-L-C resonator in shunt configuration. Due to the small number of circuit elements required, linearizers based on this technique offer low-cost and simple circuitry, hence can be utilized in handheld and cellular applications. A 1.8 GHz power amplifier with 9 dB gain is linearized using this technique. The linearizer improves the output 1-dB compression point of the power amplifier from 21 to 22.8 dBm. Adjacent channel power ratio (ACPR) is improved approximately 11 dB at an output RF power level of 17.5 dBm. The thesis is concluded by summarizing the main achievements and discussing the future work directions.

3D TEM reconstruction and segmentation process of laminar bio-nanocomposites

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

Iturrondobeitia, M., E-mail: maider.iturrondobeitia@ehu.es; Okariz, A.; Fernandez-Martinez, R.

2015-03-30

The microstructure of laminar bio-nanocomposites (Poly (lactic acid)(PLA)/clay) depends on the amount of clay platelet opening after integration with the polymer matrix and determines the final properties of the material. Transmission electron microscopy (TEM) technique is the only one that can provide a direct observation of the layer dispersion and the degree of exfoliation. However, the orientation of the clay platelets, which affects the final properties, is practically immeasurable from a single 2D TEM image. This issue can be overcome using transmission electron tomography (ET), a technique that allows the complete 3D characterization of the structure, including the measurement ofmore » the orientation of clay platelets, their morphology and their 3D distribution. ET involves a 3D reconstruction of the study volume and a subsequent segmentation of the study object. Currently, accurate segmentation is performed manually, which is inefficient and tedious. The aim of this work is to propose an objective/automated segmentation methodology process of a 3D TEM tomography reconstruction. In this method the segmentation threshold is optimized by minimizing the variation of the dimensions of the segmented objects and matching the segmented V{sub clay} (%) and the actual one. The method is first validated using a fictitious set of objects, and then applied on a nanocomposite.« less

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

Larner, J.

In this interactive session, lung SBRT patient cases will be presented to highlight real-world considerations for ensuring safe and accurate treatment delivery. An expert panel of speakers will discuss challenges specific to lung SBRT including patient selection, patient immobilization techniques, 4D CT simulation and respiratory motion management, target delineation for treatment planning, online treatment alignment, and established prescription regimens and OAR dose limits. Practical examples of cases, including the patient flow thought the clinical process are presented and audience participation will be encouraged. This panel session is designed to provide case demonstration and review for lung SBRT in terms ofmore » (1) clinical appropriateness in patient selection, (2) strategies for simulation, including 4D and respiratory motion management, and (3) applying multi imaging modality (4D CT imaging, MRI, PET) for tumor volume delineation and motion extent, and (4) image guidance in treatment delivery. Learning Objectives: Understand the established requirements for patient selection in lung SBRT Become familiar with the various immobilization strategies for lung SBRT, including technology for respiratory motion management Understand the benefits and pitfalls of applying multi imaging modality (4D CT imaging, MRI, PET) for tumor volume delineation and motion extent determination for lung SBRT Understand established prescription regimes and OAR dose limits.« less

Totally robotic vs 3D laparoscopic colectomy: A single centers preliminary experience

PubMed Central

Guerrieri, Mario; Campagnacci, Roberto; Sperti, Pierluigi; Belfiori, Giulio; Gesuita, Rosaria; Ghiselli, Roberto

2015-01-01

AIM: To compare robotic and three-dimensional (3D) laparoscopic colectomy based on the literature and our preliminary experience. METHODS: This retrospective observational study compared operative measures and postoperative outcomes between laparoscopic 3D and robotic colectomy for cancer. From September 2013 to September 2014, 24 robotic colectomies and 23 3D laparoscopic colectomy were performed at our Department. Data were analyzed and reported both by approach and by colectomy side. Robotic left colectomy (RL) vs laparoscopic 3D left colectomy (LL 3D) and Robotic right colectomy (RR) vs laparoscopic 3D (LR 3D). Rectal cancer procedures were not included. RESULTS: There were 18 RR and 11 LR 3D, 6 RL and 12 LL 3D. As regards LR 3D, extracorporeal anastomosis (EA) was performed in 7 patients and intracorporeal anastomosis (IA) in 4; the RR group included 14 IA and 4 EA. There was no mortality. Median operative time was higher for the robotic group while conversion rate (12.5% vs 13%) and lymph nodes removed (14 vs 13) were similar for both. First flatus time was 1 d for RR and 2 d the other patient groups. Oral intake was resumed in 1 d by LR and in 2 d by the other patients (P = 0.012). Overall cost was €4950 and €1950 for RL and LL 3D, and €4450 and €1450 for RR and LR 3D, respectively. CONCLUSION: There were no differences between RR and LR 3D, except that IA was easier with RR, and probably contributed with the learning curve to the longer operative time recorded. Both techniques offer similar advantages for the patient with significantly different costs. In left colectomies robotic colectomy provided better outcomes, especially in resections approaching the rectum. PMID:26674518

Association study of Demodex bacteria and facial dermatoses based on DGGE technique.

PubMed

Zhao, YaE; Yang, Fan; Wang, RuiLing; Niu, DongLing; Mu, Xin; Yang, Rui; Hu, Li

2017-03-01

The role of bacteria is unclear in the facial skin lesions caused by Demodex. To shed some light on this issue, we conducted a case-control study comparing cases with facial dermatoses with controls with healthy skin using denaturing gradient gel electrophoresis (DGGE) technique. The bacterial diversity, composition, and principal component were analyzed for Demodex bacteria and the matched facial skin bacteria. The result of mite examination showed that all 33 cases were infected with Demodex folliculorum (D. f), whereas 16 out of the 30 controls were infected with D. f, and the remaining 14 controls were infected with Demodex brevis (D. b). The diversity analysis showed that only evenness index presented statistical difference between mite bacteria and matched skin bacteria in the cases. The composition analysis showed that the DGGE bands of cases and controls were assigned to 12 taxa of 4 phyla, including Proteobacteria (39.37-52.78%), Firmicutes (2.7-26.77%), Actinobacteria (0-5.71%), and Bacteroidetes (0-2.08%). In cases, the proportion of Staphylococcus in Firmicutes was significantly higher than that in D. f controls and D. b controls, while the proportion of Sphingomonas in Proteobacteria was significantly lower than that in D. f controls. The between-group analysis (BGA) showed that all the banding patterns clustered into three groups, namely, D. f cases, D. f controls, and D. b controls. Our study suggests that the bacteria in Demodex should come from the matched facial skin bacteria. Proteobacteria and Firmicutes are the two main taxa. The increase of Staphylococcus and decrease of Sphingomonas might be associated with the development of facial dermatoses.

Towards high-precision measurement of the Tritium - He-3 mass difference

NASA Astrophysics Data System (ADS)

Shi, Wei; Redshaw, Matthew; Victoria, Juliette; Myers, Edmund

2004-05-01

An independent measurement of the mass difference of ^3He-^3T provides an important check of systematic errors in tritium beta-decay experiments that set limits to the electron anti-neutrino mass [1]. Using the precision Penning trap system developed at MIT but recently relocated to Florida State University [2], and the simultaneous two-ion cyclotron frequency measurement technique recently developed at MIT [3], we aim to measure this mass difference to better than 30 meV/c^2, more than an order of magnitude improvement over previous measurements [4,5]. Problems being addressed include producing single T^+ ions in the trap without spoiling the vacuum with ^3He, and the extension of the MIT techniques to ions of lighter mass. [1] KATRIN: http://iklau1.fzk.de/tritium [2] See abstract by Redshaw et al. [3] S. Rainville, J.K. Thompson, and D.E. Pritchard, Science 303, 334 (2004). [4] R.S. Van Dyck, D.L. Farnham, and P.B. Schwinberg, PRL 70, 2888 (1993). [5] G. Audi, A.H. Wapstra, and C. Thibault, Nuclear Physics A729, 337 (2003).

High Voltage Testing. Volume 2. Specifications and Test Procedures

DTIC Science & Technology

1982-08-01

the greatest impact on the initial assumption and criteria developed in the published criteria documents include: dielectric withstanding voltage...3382-75 Measurement of Energy and Integrated Charge Transfer Due to Partial Discharges (Corona) Using Bridge Techniques. ASTM-D 3426 - Dielectric... Energy (NEMA Publication No. WC 7-1971). NEMA Publication No. 109 - AIEE-EEI-NEMA Standard Basic Insulation Level. 092-57 - Method of Test for Flash and

Fabrication of Gold-coated 3-D Woodpile Structures for Mid-IR Thermal Emitters

NASA Astrophysics Data System (ADS)

Li, Shengkai; Moridani, Amir; Kothari, Rohit; Lee, Jae-Hwang; Watkins, James

3-D metallic woodpile nanostructures possess enhancements in thermal radiation that are both wavelength and polarization specific and are promising for thermal-optical devices for various applications including thermal photovoltaics, self-cooling devices, and chemical and bio-sensors. However, current fabrication techniques for such structures are limited by slow speed, small area capability, the need for expensive facilities and, in general, are not suitable for high-throughput mass production. Here we demonstrate a new strategy for the fabrication of 3D metallic woodpile structures. Well-defined TiO2 woodpile structures were fabricated using a layer-by-layer nanoimprint method using TiO2 nanoparticle ink dispersions. The TiO2 woodpile was then coated with a high purity, conformal gold film via reactive deposition in supercritical carbon dioxide. The final gold-coated woodpile structures exhibit strong spectral and polarization specific thermal emission enhancements. The fabrication method demonstrated here is promising for high-throughput, low-cost preparation of 3D metallic woodpile structures and other 3D nanostructures. Center for Hierarchical Manufacturing, NSF.

Comparative Study of 2D and 3D Optical Imaging Systems: Laparoendoscopic Single-Site Surgery in an Ex Vivo Model.

PubMed

Vilaça, Jaime; Pinto, José Pedro; Fernandes, Sandra; Costa, Patrício; Pinto, Jorge Correia; Leão, Pedro

2017-12-01

Usually laparoscopy is performed by means of a 2-dimensional (2D) image system and multiport approach. To overcome the lack of depth perception, new 3-dimensional (3D) systems are arising with the added advantage of providing stereoscopic vision. To further reduce surgery-related trauma, there are new minimally invasive surgical techniques being developed, such as LESS (laparoendoscopic single-site) surgery. The aim of this study was to compare 2D and 3D laparoscopic systems in LESS surgical procedures. All participants were selected from different levels of experience in laparoscopic surgery-10 novices, 7 intermediates, and 10 experts were included. None of the participants had had previous experience in LESS surgery. Participants were chosen randomly to begin their experience with either the 2D or 3D laparoscopic system. The exercise consisted of performing an ex vivo pork cholecystectomy through a SILS port with the assistance of a fixed distance laparoscope. Errors, time, and participants' preference were recorded. Statistical analysis of time and errors between groups was conducted with a Student's t test (using independent samples) and the Mann-Whitney test. In all 3 groups, the average time with the 2D system was significantly reduced after having used the 3D system ( P < .05). In the postexercise questionnaire, two thirds of participants showed a preference for using the 3D system. This study suggests that the 3D system may improve the learning curve and that learning from the 3D system is transferable to the 2D environment. Additionally, the majority of participants prefer 3D equipment.

3D GRASE PROPELLER: Improved Image Acquisition Technique for Arterial Spin Labeling Perfusion Imaging

PubMed Central

Tan, Huan; Hoge, W. Scott; Hamilton, Craig A.; Günther, Matthias; Kraft, Robert A.

2014-01-01

Arterial spin labeling (ASL) is a non-invasive technique that can quantitatively measure cerebral blood flow (CBF). While traditionally ASL employs 2D EPI or spiral acquisition trajectories, single-shot 3D GRASE is gaining popularity in ASL due to inherent SNR advantage and spatial coverage. However, a major limitation of 3D GRASE is through-plane blurring caused by T2 decay. A novel technique combining 3D GRASE and a PROPELLER trajectory (3DGP) is presented to minimize through-plane blurring without sacrificing perfusion sensitivity or increasing total scan time. Full brain perfusion images were acquired at a 3×3×5mm3 nominal voxel size with Q2TIPS-FAIR as the ASL preparation sequence. Data from 5 healthy subjects was acquired on a GE 1.5T scanner in less than 4 minutes per subject. While showing good agreement in CBF quantification with 3D GRASE, 3DGP demonstrated reduced through-plane blurring, improved anatomical details, high repeatability and robustness against motion, making it suitable for routine clinical use. PMID:21254211

Reducing scan angle using adaptive prior knowledge for a limited-angle intrafraction verification (LIVE) system for conformal arc radiotherapy.

PubMed

Zhang, Yawei; Yin, Fang-Fang; Zhang, You; Ren, Lei

2017-05-07

The purpose of this study is to develop an adaptive prior knowledge guided image estimation technique to reduce the scan angle needed in the limited-angle intrafraction verification (LIVE) system for 4D-CBCT reconstruction. The LIVE system has been previously developed to reconstruct 4D volumetric images on-the-fly during arc treatment for intrafraction target verification and dose calculation. In this study, we developed an adaptive constrained free-form deformation reconstruction technique in LIVE to further reduce the scanning angle needed to reconstruct the 4D-CBCT images for faster intrafraction verification. This technique uses free form deformation with energy minimization to deform prior images to estimate 4D-CBCT based on kV-MV projections acquired in extremely limited angle (orthogonal 3°) during the treatment. Note that the prior images are adaptively updated using the latest CBCT images reconstructed by LIVE during treatment to utilize the continuity of the respiratory motion. The 4D digital extended-cardiac-torso (XCAT) phantom and a CIRS 008A dynamic thoracic phantom were used to evaluate the effectiveness of this technique. The reconstruction accuracy of the technique was evaluated by calculating both the center-of-mass-shift (COMS) and 3D volume-percentage-difference (VPD) of the tumor in reconstructed images and the true on-board images. The performance of the technique was also assessed with varied breathing signals against scanning angle, lesion size, lesion location, projection sampling interval, and scanning direction. In the XCAT study, using orthogonal-view of 3° kV and portal MV projections, this technique achieved an average tumor COMS/VPD of 0.4  ±  0.1 mm/5.5  ±  2.2%, 0.6  ±  0.3 mm/7.2  ±  2.8%, 0.5  ±  0.2 mm/7.1  ±  2.6%, 0.6  ±  0.2 mm/8.3  ±  2.4%, for baseline drift, amplitude variation, phase shift, and patient breathing signal variation, respectively. In the CIRS phantom study, this technique achieved an average tumor COMS/VPD of 0.7  ±  0.1 mm/7.5  ±  1.3% for a 3 cm lesion and 0.6  ±  0.2 mm/11.4  ±  1.5% for a 2 cm lesion in the baseline drift case. The average tumor COMS/VPD were 0.5  ±  0.2 mm/10.8  ±  1.4%, 0.4  ±  0.3 mm/7.3  ±  2.9%, 0.4  ±  0.2 mm/7.4  ±  2.5%, 0.4  ±  0.2 mm/7.3  ±  2.8% for the four real patient breathing signals, respectively. Results demonstrated that the adaptive prior knowledge guided image estimation technique with LIVE system is robust against scanning angle, lesion size, location and scanning direction. It can estimate on-board images accurately with as little as 6 projections in orthogonal-view 3° angle. In conclusion, adaptive prior knowledge guided image reconstruction technique accurately estimates 4D-CBCT images using extremely-limited angle and projections. This technique greatly improves the efficiency and accuracy of LIVE system for ultrafast 4D intrafraction verification of lung SBRT treatments.

Full-color large-scaled computer-generated holograms for physical and non-physical objects

NASA Astrophysics Data System (ADS)

Matsushima, Kyoji; Tsuchiyama, Yasuhiro; Sonobe, Noriaki; Masuji, Shoya; Yamaguchi, Masahiro; Sakamoto, Yuji

2017-05-01

Several full-color high-definition CGHs are created for reconstructing 3D scenes including real-existing physical objects. The field of the physical objects are generated or captured by employing three techniques; 3D scanner, synthetic aperture digital holography, and multi-viewpoint images. Full-color reconstruction of high-definition CGHs is realized by RGB color filters. The optical reconstructions are presented for verifying these techniques.

A quantitative damage imaging technique based on enhanced CCRTM for composite plates using 2D scan

NASA Astrophysics Data System (ADS)

He, Jiaze; Yuan, Fuh-Gwo

2016-10-01

A two-dimensional (2D) non-contact areal scan system was developed to image and quantify impact damage in a composite plate using an enhanced zero-lag cross-correlation reverse-time migration (E-CCRTM) technique. The system comprises a single piezoelectric wafer mounted on the composite plate and a laser Doppler vibrometer (LDV) for scanning a region in the vicinity of the PZT to capture the scattered wavefield. The proposed damage imaging technique takes into account the amplitude, phase, geometric spreading, and all of the frequency content of the Lamb waves propagating in the plate; thus, a reflectivity coefficients of the delamination is calculated and potentially related to damage severity. Comparisons are made in terms of damage imaging quality between 2D areal scans and 1D line scans as well as between the proposed and existing imaging conditions. The experimental results show that the 2D E-CCRTM performs robustly when imaging and quantifying impact damage in large-scale composites using a single PZT actuator with a nearby areal scan using LDV.

Effect of heterophoria measurement technique on the clinical accommodative convergence to accommodation ratio.

PubMed

Escalante, Jaime Bernal; Rosenfield, Mark

2006-05-01

Measurement of the stimulus accommodative convergence to accommodation (AC/A) ratio is a standard procedure in clinical optometric practice. Typically, heterophoria is assessed at several accommodative stimulus levels, and the gradient of the vergence to accommodation function computed. A number of procedures are available for the subjective measurement of heterophoria, but it is unclear whether the use of different vergence measurement techniques will alter the obtained AC/A value. Accordingly, the current study compared AC/A ratios measured using 3 clinical subjective heterophoria tests, namely the von Graefe (VG), Maddox Rod (MR), and Modified Thorington (MT) procedures. The AC/A ratio was measured in 60 visually normal subjects between 20 and 25 years of age using each of the 3 procedures listed above. The accommodative stimulus was varied by the introduction of +/-1.00 diopter (D) spherical lenses over the distance refractive correction while subjects viewed a target at a viewing distance of 40 cm. To examine the repeatability of each procedure, the AC/A ratio was measured on 2 separate occasions for each measurement technique, with the 2 sessions being separated by at least 24 hours. Mean values of stimulus AC/A ratio measured using the VG, MR, and MT procedures were 3.47, 2.99, and 2.46Delta/D, respectively. These differences were significant (p=0.0001). In addition, the coefficient of repeatability for the 3 techniques was 2.22, 1.99, and 1.20 Delta/D, respectively. Ratios obtained using the Modified Thorington technique with +/-1.00 D lenses showed the best repeatability, whereas the poorest repeatability was found with the von Graefe technique when only +1.00 D lenses were used to vary the accommodative stimulus. Accordingly, we recommend that that Modified Thorington procedure with +/-1.00 D lenses be used to quantify heterophoria during clinical measurement of the stimulus AC/A ratio.

Integration of 3D printing and additive manufacturing in the interventional pulmonologist's toolbox.

PubMed

Guibert, Nicolas; Mhanna, Laurent; Didier, Alain; Moreno, Benjamin; Leyx, Pierre; Plat, Gavin; Mazieres, Julien; Hermant, Christophe

2018-01-01

New 3D technologies are rapidly entering into the surgical landscape, including in interventional pulmonology. The transition of 2D restricted data into a physical model of pathological airways by three-dimensional printing (3DP) allows rapid prototyping and fabrication of complex and patient-specific shapes and can thus help the physician to plan and guide complex procedures. Furthermore, computer-assisted designed (CAD) patient-specific devices have already helped surgeons overcome several therapeutic impasses and are likely to rapidly cover a wider range of situations. We report herein with a special focus on our clinical experience: i) how additive manufacturing is progressively integrated into the management of complex central airways diseases; ii) the appealing future directions of these new technologies, including the potential of the emerging technique of bioprinting; iii) the main pitfalls that could delay its introduction into routine care. Copyright © 2017. Published by Elsevier Ltd.

A Cylindrical, Inner Volume Selecting 2D-T2-Prep Improves GRAPPA-Accelerated Image Quality in MRA of the Right Coronary Artery

PubMed Central

Coristine, Andrew J.; Yerly, Jerome; Stuber, Matthias

2016-01-01

Background Two-dimensional (2D) spatially selective radiofrequency (RF) pulses may be used to excite restricted volumes. By incorporating a "pencil beam" 2D pulse into a T2-Prep, one may create a "2D-T2-Prep" that combines T2-weighting with an intrinsic outer volume suppression. This may particularly benefit parallel imaging techniques, where artefacts typically originate from residual foldover signal. By suppressing foldover signal with a 2D-T2-Prep, image quality may therefore improve. We present numerical simulations, phantom and in vivo validations to address this hypothesis. Methods A 2D-T2-Prep and a conventional T2-Prep were used with GRAPPA-accelerated MRI (R = 1.6). The techniques were first compared in numerical phantoms, where per pixel maps of SNR (SNRmulti), noise, and g-factor were predicted for idealized sequences. Physical phantoms, with compartments doped to mimic blood, myocardium, fat, and coronary vasculature, were scanned with both T2-Preparation techniques to determine the actual SNRmulti and vessel sharpness. For in vivo experiments, the right coronary artery (RCA) was imaged in 10 healthy adults, using accelerations of R = 1,3, and 6, and vessel sharpness was measured for each. Results In both simulations and phantom experiments, the 2D-T2-Prep improved SNR relative to the conventional T2-Prep, by an amount that depended on both the acceleration factor and the degree of outer volume suppression. For in vivo images of the RCA, vessel sharpness improved most at higher acceleration factors, demonstrating that the 2D-T2-Prep especially benefits accelerated coronary MRA. Conclusion Suppressing outer volume signal with a 2D-T2-Prep improves image quality particularly well in GRAPPA-accelerated acquisitions in simulations, phantoms, and volunteers, demonstrating that it should be considered when performing accelerated coronary MRA. PMID:27736866

Application of 3D printed customized external fixator in fracture reduction.

PubMed

Qiao, Feng; Li, Dichen; Jin, Zhongmin; Gao, Yongchang; Zhou, Tao; He, Jinlong; Cheng, Li

2015-01-01

Long bone fracture is common in traumatic osteopathic patients. Good reduction is beneficial for bone healing, preventing the complications such as delayed union, nonunion, malunion, but is hard to achieve. Repeated attempts during the surgery would increase the operation time, cause new damage to the fracture site and excessive exposure to radiation. Robotic and navigation techniques can help improve the reduction accuracy, however, the high cost and complexity of operation have limited their clinical application. We combined 3D printing with computer-assisted reduction technique to develop a customised external fixator with the function of fracture reduction. The original CT data obtained by scanning the fracture was imported to computer for reconstructing and reducing the 3D image of the fracture, based on which the external fixator (named as Q-Fixator) was designed and then fabricated by 3D printing techniques. The fracture reduction and fixation was achieved by connecting the pins inserted in the bones with the customised Q-Fixator. Experiments were conducted on three fracture models to demonstrate the reduction results. Good reduction results were obtained on all three fractured bone models, with an average rotation of 1.21°(± 0.24), angulation of 1.84°(± 0.28), and lateral displacement of 2.22 mm(± 0.62). A novel customised external fixator for long bone fracture reduction was readily developed using 3D printing technique. The customised external fixator had the advantages of easy manipulation, accurate reduction, minimally invasion and experience-independence. Future application of the customised external fixator can be extended to include the fixation function with stress adjustment and potentially optimise the fracture healing process. Copyright © 2015 Elsevier Ltd. All rights reserved.

Biomaterial shell bending with 3D-printed templates in vertical and alveolar ridge augmentation: a technical note.

PubMed

Draenert, Florian G; Gebhart, Florian; Mitov, Gergo; Neff, Andreas

2017-06-01

Alveolar ridge and vertical augmentations are challenging procedures in dental implantology. Even material blocks with an interconnecting porous system are never completely resorbed. Shell techniques combined with autologous bone chips are therefore the gold standard. Using biopolymers for these techniques is well documented. We applied three-dimensional (3-D) techniques to create an individualized bending model for the adjustment of a plane biopolymer membrane made of polylactide. Two cases with a vertical alveolar ridge defect in the maxilla were chosen. The cone beam computed tomography data were processed with a 3-D slicer and the Autodesk Meshmixer to generate data about the desired augmentation result. STL data were used to print a bending model. A 0.2-mm poly-D, L-lactic acid membrane (KLS Matin Inc., Tuttlingen, Germany) was bended accordingly and placed into the defect via a tunnel approach in both cases. A mesh graft of autologous bone chips and hydroxylapatite material was augmented beneath the shell, which was fixed with osteosynthesis screws. The operative procedure was fast and without peri- or postoperative complications or complaints. The panoramic x-ray showed correct fitting of the material in the location. Bone quality at the time of implant placement was type II, resulting in good primary stability. A custom-made 3-D model for bending confectioned biomaterial pieces is an appropriate method for individualized adjustment in shell techniques. The advantages over direct printing of the biomaterial shell and products on the market, such as the Xyoss shell (Reoss Inc., Germany), include cost-efficiency and avoidance of regulatory issues. Copyright © 2016 Elsevier Inc. All rights reserved.

1H Spectroscopic Imaging of Human Brain at 3T: Comparison of Fast 3D-MRSI Techniques

PubMed Central

Zierhut, Matthew L.; Ozturk-Isik, Esin; Chen, Albert P.; Park, Ilwoo; Vigneron, Daniel B.; Nelson, Sarah J.

2011-01-01

Purpose To investigate the signal-to-noise-ratio (SNR) and data quality of time-reduced 1H 3D-MRSI techniques in the human brain at 3T. Materials and Methods Techniques that were investigated included ellipsoidal k-space sampling, parallel imaging, and EPSI. The SNR values for NAA, Cho, Cre, and lactate or lipid peaks were compared after correcting for effective spatial resolution and acquisition time in a phantom and in the brains of human volunteers. Other factors considered were linewidths, metabolite ratios, partial volume effects, and subcutaneous lipid contamination. Results In volunteers, the median normalized SNR for parallel imaging data decreased by 34–42%, but could be significantly improved using regularization. The normalized signal to noise loss in flyback EPSI data was 11–18%. The effective spatial resolutions of the traditional, ellipsoidal, SENSE, and EPSI data were 1.02, 2.43, 1.03, and 1.01cm3, respectively. As expected, lipid contamination was variable between subjects but was highest for the SENSE data. Patient data obtained using the flyback EPSI method were of excellent quality. Conclusions Data from all 1H 3D-MRSI techniques were qualitatively acceptable, based upon SNR, linewidths, and metabolite ratios. The larger FOV obtained with the EPSI methods showed negligible lipid aliasing with acceptable SNR values in less than 9.5 minutes without compromising the PSF. PMID:19711396

In situ nuclear magnetic resonance microimaging of live biofilms in a microchannel

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

Renslow, R. S.; Marshall, M. J.; Tucker, A. E.

Nuclear magnetic resonance (NMR) microimaging and spectroscopy was used to interrogate fluids of biological importance (e.g., water, buffer, medium solution) and live biofilms in a microchannel compatible for analyses at ambient pressure and under vacuum. Studies using buffer, growth medium, and actively growing Shewanella oneidensis biofilms were used to demonstrate in situ NMR microimaging measurement capabilities including velocity mapping, diffusion coefficient mapping, relaxometry, localized spectroscopy, and 2D and 3D imaging within a microchannel suitable for different analytical platforms. This technique is promising for diverse applications of correlative imaging using a portable microfluidic platform.

Verticillosides A-M: Polyoxygenated pregnane glycosides from Asclepias verticillata L.

PubMed

Araya, Juan J; Binns, Franklin; Kindscher, Kelly; Timmermann, Barbara N

2012-06-01

As part of our ongoing effort to explore the chemical diversity of plants of the United States Midwest region, the isolation and identification of 13 pregnane glycosides named verticillosides A-M from Asclepias verticillata L. are reported. The structures of these compounds were elucidated by various spectroscopic techniques, including 1D and 2D NMR, IR, UV, and HRMS. The cytotoxicity of the isolates was evaluated against paired breast cell lines Hs578T (cancer) and Hs578Bst (normal), however, no significant growth inhibition was observed. Copyright © 2012 Elsevier Ltd. All rights reserved.

Post-patterning of an electronic homojunction in atomically thin monoclinic MoTe2

NASA Astrophysics Data System (ADS)

Kim, Sera; Kim, Jung Ho; Kim, Dohyun; Hwang, Geunwoo; Baik, Jaeyoon; Yang, Heejun; Cho, Suyeon

2017-06-01

Monoclinic group 6 transition metal dichalcogenides (TMDs) have been extensively studied for their intriguing 2D physics (e.g. spin Hall insulator) as well as for ohmic homojunction contacts in 2D device applications. A critical prerequisite for those applications is thickness control of the monoclinic 2D materials, which allows subtle engineering of the topological states or electronic bandgaps. Local thickness control enables the realization of clean homojunctions between different electronic states, and novel device operation in a single material. However, conventional fabrication processes, including chemical methods, typically produce non-homogeneous and relatively thick monoclinic TMDs, due to their distorted octahedral structures. Here, we report on a post-patterning technique using laser-irradiation to fabricate homojunctions between two different thickness areas in monoclinic MoTe2. A thickness-dependent electronic change from a metallic to semiconducting state, resulting in an electronic homojunction, was realized by the optical patterning of pristine MoTe2 flakes, and a pre-patterned device channel of monoclinic MoTe2 with a thickness-resolution of 5 nm. Our work provides insight on an optical post-process method for controlling thickness, as a promising approach for fabricating impurity-free 2D TMDs homojunction devices.

Antioxidant, anti-glycation and anti-inflammatory activities of phenolic constituents from Cordia sinensis.

PubMed

Al-Musayeib, Nawal; Perveen, Shagufta; Fatima, Itrat; Nasir, Muhammad; Hussain, Ajaz

2011-12-08

Nine compounds have been isolated from the ethyl acetate soluble fraction of C. sinensis, namely protocatechuic acid (1), trans-caffeic acid (2), methyl rosmarinate (3), rosmarinic acid (4), kaempferide-3-O-β-D-glucopyranoside (5), kaempferol-3-O-β-D-glucopyranoside (6), quercetin-3-O-β-D-glucopyranoside (7), kaempferide-3-O-α-L-rhamnopyranosyl (1→6)-β-D-glucopyranoside (8) and kaempferol-3-O-α-L-rhamno-pyranosyl (1→6)-β-D-glucopyranoside (9), all reported for the first time from this species. The structures of these compounds were deduced on the basis of spectroscopic studies, including 1D and 2D NMR techniques. Compounds 1-9 were investigated for biological activity and showed significant anti-inflammatory activity in the carrageen induced rat paw edema test. The antioxidant activities of isolated compounds 1-9 were evaluated by the DPPH radical scavenging test, and compounds 1, 2, 4 and 7-9 exhibited marked scavenging activity compared to the standard BHA. These compounds were further studied for their anti-glycation properties and some compounds showed significant anti-glycation inhibitory activity. The purity of compounds 2-5, 8 and 9 was confirmed by HPLC. The implications of these results for the chemotaxonomic studies of the genus Cordia have also been discussed.

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

Kumaran Nair, C; Hoffman, D; Wright, C

Purpose: We aim to evaluate a new commercial dose mimicking inverse-planning application that was designed to provide cross-platform treatment planning, for its dosimetric quality and efficiency. The clinical benefit of this application allows patients treated on O-shaped linac to receive an equivalent plan on conventional L-shaped linac as needed for workflow or machine downtime. Methods: The dose mimicking optimization process seeks to create a similar DVH of an O-shaped linac-based plans with an alternative treatment technique (IMRT or VMAT), by maintaining target conformity, and penalizing dose falloff outside the target. Ten head and neck (HN) helical delivery plans, including simplemore » and complex cases were selected for re-planning with the dose mimicking application. All plans were generated for a 6 MV beam model, using 7-field/ 9-field IMRT and VMAT techniques. PTV coverage (D1, D99 and homogeneity index [HI]), and OARs avoidance (Dmean / Dmax) were compared. Results: The resulting dose mimicked HN plans achieved acceptable PTV coverage for HI (VMAT 7.0±2.3, 7-fld 7.3±2.4, and 9-fld 7.0±2.4), D99 (98.0%±0.7%, 97.8%±0.7%, and 98.0%±0.7%), as well as D1 (106.4%±2.1%, 106.5%±2.2%, and 106.4%±2.1%), respectively. The OAR dose discrepancy varied: brainstem (2% to 4%), cord (3% to 6%), esophagus (−4% to −8%), larynx (−4% to 2%), and parotid (4% to 14%). Mimicked plans would typically be needed for 1–5 fractions of a treatment course, and we estimate <1% variance would be introduced in target coverage while maintaining comparable low dose to OARs. All mimicked plans were approved by independent physician and passed patient specific QA within our established tolerance. Conclusion: Dose mimicked plans provide a practical alternative for responding to clinical workflow issues, and provide reliability for patient treatment. The quality of dose mimicking for HN patients highly depends on the delivery technique, field numbers and angles, as well as user selection of structures.« less

Unstable simple volatiles and gas chromatography-tandem mass spectrometry analysis of essential oil from the roots bark of Oplopanax horridus extracted by supercritical fluid extraction.

PubMed

Shao, Li; Bao, Mei-Hua; Ouyang, Dong-Sheng; Wang, Chong-Zhi; Yuan, Chun-Su; Zhou, Hong-Hao; Huang, Wei-Hua

2014-11-27

Volatile oil from the root bark of Oplopanax horridus is regarded to be responsible for the clinical uses of the title plant as a respiratory stimulant and expectorant. Therefore, a supercritical fluid extraction method was first employed to extract the volatile oil from the roots bark of O. horridus, which was subsequently analyzed by GC/MS. Forty-eight volatile compounds were identified by GC/MS analysis, including (S,E)-nerolidol (52.5%), τ-cadinol (21.6%) and S-falcarinol (3.6%). Accordingly, the volatile oil (100 g) was subjected to chromatographic separation and purification. As a result, the three compounds, (E)-nerolidol (2 g), τ-cadinol (62 mg) and S-falcarinol (21 mg), were isolated and purified from the volatile oil, the structures of which were unambiguously elucidated by detailed spectroscopic analysis including 1D- and 2D-NMR techniques.

Three-dimensional imaging of porous media using confocal laser scanning microscopy.

PubMed

Shah, S M; Crawshaw, J P; Boek, E S

2017-02-01

In the last decade, imaging techniques capable of reconstructing three-dimensional (3-D) pore-scale model have played a pivotal role in the study of fluid flow through complex porous media. In this study, we present advances in the application of confocal laser scanning microscopy (CLSM) to image, reconstruct and characterize complex porous geological materials with hydrocarbon reservoir and CO 2 storage potential. CLSM has a unique capability of producing 3-D thin optical sections of a material, with a wide field of view and submicron resolution in the lateral and axial planes. However, CLSM is limited in the depth (z-dimension) that can be imaged in porous materials. In this study, we introduce a 'grind and slice' technique to overcome this limitation. We discuss the practical and technical aspects of the confocal imaging technique with application to complex rock samples including Mt. Gambier and Ketton carbonates. We then describe the complete workflow of image processing to filtering and segmenting the raw 3-D confocal volumetric data into pores and grains. Finally, we use the resulting 3-D pore-scale binarized confocal data obtained to quantitatively determine petrophysical pore-scale properties such as total porosity, macro- and microporosity and single-phase permeability using lattice Boltzmann (LB) simulations, validated by experiments. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

An Integrated Calibration Technique for Stereo Vision Systems (PREPRINT)

DTIC Science & Technology

2010-03-01

technique for stereo vision systems has been developed. To demonstrate and evaluate this calibration technique, multiple Wii Remotes (Wiimotes) from Nintendo ...from Nintendo were used to form stereo vision systems to perform 3D motion capture in real time. This integrated technique is a two-step process...Wiimotes) used in Nintendo Wii games. Many researchers have successfully dealt with the problem of camera calibration by taking images from a 2D

Ray-based approach to integrated 3D visual communication

NASA Astrophysics Data System (ADS)

Naemura, Takeshi; Harashima, Hiroshi

2001-02-01

For a high sense of reality in the next-generation communications, it is very important to realize three-dimensional (3D) spatial media, instead of existing 2D image media. In order to comprehensively deal with a variety of 3D visual data formats, the authors first introduce the concept of "Integrated 3D Visual Communication," which reflects the necessity of developing a neutral representation method independent of input/output systems. Then, the following discussions are concentrated on the ray-based approach to this concept, in which any visual sensation is considered to be derived from a set of light rays. This approach is a simple and straightforward to the problem of how to represent 3D space, which is an issue shared by various fields including 3D image communications, computer graphics, and virtual reality. This paper mainly presents the several developments in this approach, including some efficient methods of representing ray data, a real-time video-based rendering system, an interactive rendering system based on the integral photography, a concept of virtual object surface for the compression of tremendous amount of data, and a light ray capturing system using a telecentric lens. Experimental results demonstrate the effectiveness of the proposed techniques.

MO-B-BRD-03: Principles, Pitfalls and Techniques of 3D Printing for Bolus and Compensators

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

Baker, J.

This session is designed so that the learning objectives are practical. The intent is that the attendee may take home an understanding of not just the technology, but also the logistical steps necessary to execute these 3D printing techniques in the clinic. Four practical 3D printing topics will be discussed: (i) Creating bolus and compensators for photon machines; (ii) tools for proton therapy; (iii) clinical applications in imaging; (iv) custom phantom design for clinic and research use. The use of 3D printers within the radiation oncology setting is proving to be a useful tool for creating patient specific bolus andmore » compensators with the added benefit of cost savings. Creating the proper protocol is essential to ensuring that the desired effect is achieved and modeled in the treatment planning system. The critical choice of printer material (since it determines the interaction with the radiation) will be discussed. Selection of 3D printer type, design methods, verification of dose calculation, and the printing process will be detailed to give the basis for establishing your own protocol for electron and photon fields. A practical discussion of likely obstacles that may be encountered will be included. The diversity of systems and techniques in proton facilities leads to different facilities having very different requirements for beam modifying hardware and quality assurance devices. Many departments find the need to design and fabricate facility-specific equipment, making 3D printing an attractive technology. 3D printer applications in proton therapy will be discussed, including beam filters and compensators, and the design of proton therapy specific quality assurance tools. Quality control specific to 3D printing in proton therapy will be addressed. Advantages and disadvantages of different printing technology for these applications will also be discussed. 3D printing applications using high-resolution radiology-based imaging data will be presented. This data is used to 3D print individualized physical models of patient’s unique anatomy for aid in planning complex and challenging surgical procedures. Methods, techniques and imaging requirements for 3D printing anatomic models from imaging data will be discussed. Specific applications currently being used in the radiology clinic will be detailed. Standardized phantoms for radiation therapy are abundant. However, custom phantom designs can be advantageous for both clinical tasks and research. 3D printing is a useful method of custom fabrication that allows one to construct custom objects relatively quickly. Possibilities for custom radiotherapy phantoms range from 3D printing a hollow shell and filling the shell with tissue equivalent materials to fully printing the entire phantom with materials that are tissue equivalent as well as suitable for 3D printing. A range of materials available for use in radiotherapy phantoms and in the case of phantoms for dosimetric measurements, this choice is critical. The necessary steps required will be discussed including: modalities of 3D model generation, 3D model requirements for 3D printing, generation of machine instructions from the 3D model, and 3D printing techniques, choice of phantoms material, and troubleshooting techniques for each step in the process. Case examples of 3D printed phantoms will be shown. Learning Objectives: Understand the types of 3D modeling software required to design your device, the file formats required for data transfer from design software to 3D printer, and general troubleshooting techniques for each step of the process. Learn the differences between materials and design for photons vs. electrons vs. protons. Understand the importance of material choice and design geometries for your custom phantoms. Learn specific steps of quality assurance and quality control for 3D printed beam filters and compensators for proton therapy. Learn of special 3D printing applications for imaging. Cunha: Research support from Phillips Healthcare.« less

Prolongation of liver-specific function for primary hepatocytes maintenance in 3D printed architectures.

PubMed

Kim, Yohan; Kang, Kyojin; Yoon, Sangtae; Kim, Ji Sook; Park, Su A; Kim, Wan Doo; Lee, Seung Bum; Ryu, Ki-Young; Jeong, Jaemin; Choi, Dongho

2018-01-02

Isolated primary hepatocytes from the liver are very similar to in vivo native liver hepatocytes, but they have the disadvantage of a limited lifespan in 2D culture. Although a sandwich culture and 3D organoids with mesenchymal stem cells (MSCs) as an attractive assistant cell source to extend lifespan can be used, it cannot fully reproduce the in vivo architecture. Moreover, long-term 3D culture leads to cell death because of hypoxic stress. Therefore, to overcome the drawback of 2D and 3D organoids, we try to use a 3D printing technique using alginate hydrogels with primary hepatocytes and MSCs. The viability of isolated hepatocytes was more than 90%, and the cells remained alive for 7 days without morphological changes in the 3D hepatic architecture with MSCs. Compared to a 2D system, the expression level of functional hepatic genes and proteins was higher for up to 7 days in the 3D hepatic architecture. These results suggest that both the 3D bio-printing technique and paracrine molecules secreted by MSCs supported long-term culture of hepatocytes without morphological changes. Thus, this technique allows for widespread expansion of cells while forming multicellular aggregates, may be applied to drug screening and could be an efficient method for developing an artificial liver.

Modelling of 3D fractured geological systems - technique and application

NASA Astrophysics Data System (ADS)

Cacace, M.; Scheck-Wenderoth, M.; Cherubini, Y.; Kaiser, B. O.; Bloecher, G.

2011-12-01

All rocks in the earth's crust are fractured to some extent. Faults and fractures are important in different scientific and industry fields comprising engineering, geotechnical and hydrogeological applications. Many petroleum, gas and geothermal and water supply reservoirs form in faulted and fractured geological systems. Additionally, faults and fractures may control the transport of chemical contaminants into and through the subsurface. Depending on their origin and orientation with respect to the recent and palaeo stress field as well as on the overall kinematics of chemical processes occurring within them, faults and fractures can act either as hydraulic conductors providing preferential pathways for fluid to flow or as barriers preventing flow across them. The main challenge in modelling processes occurring in fractured rocks is related to the way of describing the heterogeneities of such geological systems. Flow paths are controlled by the geometry of faults and their open void space. To correctly simulate these processes an adequate 3D mesh is a basic requirement. Unfortunately, the representation of realistic 3D geological environments is limited by the complexity of embedded fracture networks often resulting in oversimplified models of the natural system. A technical description of an improved method to integrate generic dipping structures (representing faults and fractures) into a 3D porous medium is out forward. The automated mesh generation algorithm is composed of various existing routines from computational geometry (e.g. 2D-3D projection, interpolation, intersection, convex hull calculation) and meshing (e.g. triangulation in 2D and tetrahedralization in 3D). All routines have been combined in an automated software framework and the robustness of the approach has been tested and verified. These techniques and methods can be applied for fractured porous media including fault systems and therefore found wide applications in different geo-energy related topics including CO2 storage in deep saline aquifers, shale gas extraction and geothermal heat recovery. The main advantage is that dipping structures can be integrated into a 3D body representing the porous media and the interaction between the discrete flow paths through and across faults and fractures and within the rock matrix can be correctly simulated. In addition the complete workflow is captured by open-source software.

Integral refractive index imaging of flowing cell nuclei using quantitative phase microscopy combined with fluorescence microscopy.

PubMed

Dardikman, Gili; Nygate, Yoav N; Barnea, Itay; Turko, Nir A; Singh, Gyanendra; Javidi, Barham; Shaked, Natan T

2018-03-01

We suggest a new multimodal imaging technique for quantitatively measuring the integral (thickness-average) refractive index of the nuclei of live biological cells in suspension. For this aim, we combined quantitative phase microscopy with simultaneous 2-D fluorescence microscopy. We used 2-D fluorescence microscopy to localize the nucleus inside the quantitative phase map of the cell, as well as for measuring the nucleus radii. As verified offline by both 3-D confocal fluorescence microscopy and 2-D fluorescence microscopy while rotating the cells during flow, the nucleus of cells in suspension that are not during division can be assumed to be an ellipsoid. The entire shape of a cell in suspension can be assumed to be a sphere. Then, the cell and nucleus 3-D shapes can be evaluated based on their in-plain radii available from the 2-D phase and fluorescent measurements, respectively. Finally, the nucleus integral refractive index profile is calculated. We demonstrate the new technique on cancer cells, obtaining nucleus refractive index values that are lower than those of the cytoplasm, coinciding with recent findings. We believe that the proposed technique has the potential to be used for flow cytometry, where full 3-D refractive index tomography is too slow to be implemented during flow.

A Novel 2D Image Compression Algorithm Based on Two Levels DWT and DCT Transforms with Enhanced Minimize-Matrix-Size Algorithm for High Resolution Structured Light 3D Surface Reconstruction

NASA Astrophysics Data System (ADS)

Siddeq, M. M.; Rodrigues, M. A.

2015-09-01

Image compression techniques are widely used on 2D image 2D video 3D images and 3D video. There are many types of compression techniques and among the most popular are JPEG and JPEG2000. In this research, we introduce a new compression method based on applying a two level discrete cosine transform (DCT) and a two level discrete wavelet transform (DWT) in connection with novel compression steps for high-resolution images. The proposed image compression algorithm consists of four steps. (1) Transform an image by a two level DWT followed by a DCT to produce two matrices: DC- and AC-Matrix, or low and high frequency matrix, respectively, (2) apply a second level DCT on the DC-Matrix to generate two arrays, namely nonzero-array and zero-array, (3) apply the Minimize-Matrix-Size algorithm to the AC-Matrix and to the other high-frequencies generated by the second level DWT, (4) apply arithmetic coding to the output of previous steps. A novel decompression algorithm, Fast-Match-Search algorithm (FMS), is used to reconstruct all high-frequency matrices. The FMS-algorithm computes all compressed data probabilities by using a table of data, and then using a binary search algorithm for finding decompressed data inside the table. Thereafter, all decoded DC-values with the decoded AC-coefficients are combined in one matrix followed by inverse two levels DCT with two levels DWT. The technique is tested by compression and reconstruction of 3D surface patches. Additionally, this technique is compared with JPEG and JPEG2000 algorithm through 2D and 3D root-mean-square-error following reconstruction. The results demonstrate that the proposed compression method has better visual properties than JPEG and JPEG2000 and is able to more accurately reconstruct surface patches in 3D.

Insights into drug metabolism by cytochromes P450 from modelling studies of CYP2D6-drug interactions

PubMed Central

Maréchal, J-D; Kemp, C A; Roberts, G C K; Paine, M J I; Wolf, C R; Sutcliffe, M J

2008-01-01

The cytochromes P450 (CYPs) comprise a vast superfamily of enzymes found in virtually all life forms. In mammals, xenobiotic metabolizing CYPs provide crucial protection from the effects of exposure to a wide variety of chemicals, including environmental toxins and therapeutic drugs. Ideally, the information on the possible metabolism by CYPs required during drug development would be obtained from crystal structures of all the CYPs of interest. For some years only crystal structures of distantly related bacterial CYPs were available and homology modelling techniques were used to bridge the gap and produce structural models of human CYPs, and thereby obtain useful functional information. A significant step forward in the reliability of these models came seven years ago with the first crystal structure of a mammalian CYP, rabbit CYP2C5, followed by the structures of six human enzymes, CYP1A2, CYP2A6, CYP2C8, CYP2C9, CYP2D6 and CYP3A4, and a second rabbit enzyme, CYP2B4. In this review we describe as a case study the evolution of a CYP2D6 model, leading to the validation of the model as an in silico tool for predicting binding and metabolism. This work has led directly to the successful design of CYP2D6 mutants with novel activity—including creating a testosterone hydroxylase, converting quinidine from inhibitor to substrate, creating a diclofenac hydroxylase and creating a dextromethorphan O-demethylase. Our modelling-derived hypothesis-driven integrated interdisciplinary studies have given key insight into the molecular determinants of CYP2D6 and other important drug metabolizing enzymes. PMID:18026129

3D thermography imaging standardization technique for inflammation diagnosis

NASA Astrophysics Data System (ADS)

Ju, Xiangyang; Nebel, Jean-Christophe; Siebert, J. Paul

2005-01-01

We develop a 3D thermography imaging standardization technique to allow quantitative data analysis. Medical Digital Infrared Thermal Imaging is very sensitive and reliable mean of graphically mapping and display skin surface temperature. It allows doctors to visualise in colour and quantify temperature changes in skin surface. The spectrum of colours indicates both hot and cold responses which may co-exist if the pain associate with an inflammatory focus excites an increase in sympathetic activity. However, due to thermograph provides only qualitative diagnosis information, it has not gained acceptance in the medical and veterinary communities as a necessary or effective tool in inflammation and tumor detection. Here, our technique is based on the combination of visual 3D imaging technique and thermal imaging technique, which maps the 2D thermography images on to 3D anatomical model. Then we rectify the 3D thermogram into a view independent thermogram and conform it a standard shape template. The combination of these imaging facilities allows the generation of combined 3D and thermal data from which thermal signatures can be quantified.

LOD-Sprite Technique for Accelerated Terrain Rendering

DTIC Science & Technology

1999-01-01

includes limited parallax, is possible. Another category samples the full plenoptic function, resulting in 3D, 4D or even 5D image sprites [13, 10... Plenoptic modeling: An image- based rendering system. Computer Graphics (Proc. SIG- GRAPH ’95), pages 39–46, 1995. [19] P. Rademacher and G. Bishop

Chemical constituents of Cichorium intybus and their inhibitory effects against urease and alpha-chymotrypsin enzymes.

PubMed

Saied, Sumayya; Shah, Shazia; Ali, Zulfiqar; Khan, Ajmal; Marasini, Bishnu P; Choudhary, Muhammad Iqbal

2011-08-01

Phytochemical investigation of the aerial parts of Cichorium intybus L. resulted in the isolation and identification of two new natural metabolites, 2,6-di[but-3(E)-en-2-onyl]naphthalene (1), and 3,3',4,4'-tetrahydroxychalcone (2), along with nine known compounds. Their structures were determined by spectroscopic techniques including 1D and 2D NMR. The known compounds were identified as scopoletin (3), 4-hydroxyphenylacetic acid (4), 3-hydroxy-4-methoxybenzoic acid (5), 4,4'-dihydroxychalcone (6), 6,7-dihydroxycoumarine (7), 1-triacontanol (8), lupeol (9), beta-sitosterol (10), and beta-sitosterol-3-O-beta-glucopyranoside (11). Compounds 4-6 and 8 are reported for the first time from C. intybus. Compounds 2 and 3 showed weak inhibitory activities against urease and alpha-chymotrypsin enzymes, respectively.

Three new diphenyl ether derivatives from the fermentation products of an endophytic fungus Phomopsis fukushii.

PubMed

Gao, Yu-Hong; Zheng, Rui; Li, Jing; Kong, Wei-Song; Liu, Xin; Ye, Lin; Mi, Qi-Li; Kong, Wei-Song; Zhou, Min; Yang, Guang-Yu; Hu, Qiu-Fen; Du, Gang; Yang, Hai-Ying; Li, Xue-Mei

2018-01-17

Three new diphenyl ethers (1-3), together with four known isopentylated diphenyl ethers derivatives (4-7), were isolated from the fermentation products of an endophytic fungus Phomopsis fukushii. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1-3 were evaluated for their anti-methicillin-resistant Staphylococcus aureus (anti-MRSA) activity. The results revealed that compounds 1 and 2 showed strong inhibitions with inhibition zone diameters (IZD) of 20.2 ± 2.5 mm and 17.9 ± 2.2 mm, respectively. Compound 3 also showed good inhibition with IZD 15.2 ± 1.8 mm. The IZD data of compound 1 is close to that of positive control with IZD 21.9 ± 2.1 mm.

Three-dimensional volumetric analysis of irradiated lung with adjuvant breast irradiation.

PubMed

Teh, Amy Yuen Meei; Park, Eileen J H; Shen, Liang; Chung, Hans T

2009-12-01

To retrospectively evaluate the dose-volume histogram data of irradiated lung in adjuvant breast radiotherapy (ABR) using a three-dimensional computed tomography (3D-CT)-guided planning technique; and to investigate the relationship between lung dose-volume data and traditionally used two-dimensional (2D) parameters, as well as their correlation with the incidence of steroid-requiring radiation pneumonitis (SRRP). Patients beginning ABR between January 2005 and February 2006 were retrospectively reviewed. Patients included were women aged >or=18 years with ductal carcinoma in situ or Stage I-III invasive carcinoma, who received radiotherapy using a 3D-CT technique to the breast or chest wall (two-field radiotherapy [2FRT]) with or without supraclavicular irradiation (three-field radiotherapy [3FRT]), to 50 Gy in 25 fractions. A 10-Gy tumor-bed boost was allowed. Lung dose-volume histogram parameters (V(10), V(20), V(30), V(40)), 2D parameters (central lung depth [CLD], maximum lung depth [MLD], and lung length [LL]), and incidence of SRRP were reported. A total of 89 patients met the inclusion criteria: 51 had 2FRT, and 38 had 3FRT. With 2FRT, mean ipsilateral V(10), V(20), V(30), V(40) and CLD, MLD, LL were 20%, 14%, 11%, and 8% and 2.0 cm, 2.1 cm, and 14.6 cm, respectively, with strong correlation between CLD and ipsilateral V(10-V40) (R(2) = 0.73-0.83, p < 0.0005). With 3FRT, mean ipsilateral V(10), V(20), V(30), and V(40) were 30%, 22%, 17%, and 11%, but its correlation with 2D parameters was poor. With a median follow-up of 14.5 months, 1 case of SRRP was identified. With only 1 case of SRRP observed, our study is limited in its ability to provide definitive guidance, but it does provide a starting point for acceptable lung irradiation during ABR. Further prospective studies are warranted.

D Digitization and Mapping of Heritage Monuments and Comparison with Historical Drawings

NASA Astrophysics Data System (ADS)

Fiorillo, F.; Remondino, F.; Barba, S.; Santoriello, A.; De Vita, C. B.; Casellato, A.

2013-07-01

The paper presents the integration of different 3D recording techniques and instruments to survey the archaeological area of Paestum (Italy). Paestum was included in the UNESCO World Heritage list since 1998, and still preserves the ruins of Greek and Roman times. Photogrammetry and terrestrial laser scanning (TLS) acquisitions were integrated in order to exploit the advantages of the 3D surveying techniques and produce digital models, orthoimages, maps and other geometric representations useful for archaeological, architectural and cultural touristic purposes. The obtained 3D results are then compared to historical representations to show the high quality of such ancient manual drawings.

Rescuing the Clinical Breast Examination: Advances in Classifying Technique and Assessing Physician Competency.

PubMed

Laufer, Shlomi; D'Angelo, Anne-Lise D; Kwan, Calvin; Ray, Rebbeca D; Yudkowsky, Rachel; Boulet, John R; McGaghie, William C; Pugh, Carla M

2017-12-01

Develop new performance evaluation standards for the clinical breast examination (CBE). There are several, technical aspects of a proper CBE. Our recent work discovered a significant, linear relationship between palpation force and CBE accuracy. This article investigates the relationship between other technical aspects of the CBE and accuracy. This performance assessment study involved data collection from physicians (n = 553) attending 3 different clinical meetings between 2013 and 2014: American Society of Breast Surgeons, American Academy of Family Physicians, and American College of Obstetricians and Gynecologists. Four, previously validated, sensor-enabled breast models were used for clinical skills assessment. Models A and B had solitary, superficial, 2 cm and 1 cm soft masses, respectively. Models C and D had solitary, deep, 2 cm hard and moderately firm masses, respectively. Finger movements (search technique) from 1137 CBE video recordings were independently classified by 2 observers. Final classifications were compared with CBE accuracy. Accuracy rates were model A = 99.6%, model B = 89.7%, model C = 75%, and model D = 60%. Final classification categories for search technique included rubbing movement, vertical movement, piano fingers, and other. Interrater reliability was (k = 0.79). Rubbing movement was 4 times more likely to yield an accurate assessment (odds ratio 3.81, P < 0.001) compared with vertical movement and piano fingers. Piano fingers had the highest failure rate (36.5%). Regression analysis of search pattern, search technique, palpation force, examination time, and 6 demographic variables, revealed that search technique independently and significantly affected CBE accuracy (P < 0.001). Our results support measurement and classification of CBE techniques and provide the foundation for a new paradigm in teaching and assessing hands-on clinical skills. The newly described piano fingers palpation technique was noted to have unusually high failure rates. Medical educators should be aware of the potential differences in effectiveness for various CBE techniques.

[Clinical and laboratory features of pediatric acute myeloid leukemia with inversion of chromosome 16].

PubMed

He, Ya-xiang; Xue, Yong-quan; Wang, Hong-ying; Yang, Nai-chao; Shao, Xue-jun; Xu, Jun; Ji, Zheng-hua; Huang, Yi-ping; Ding, Yun-fang; Hu, Shao-yan

2012-08-01

To evaluate the clinical and laboratory features of pediatric inv(16) acute myeloid leukemia (AML) retrospectively. Dual color fluorescence in situ hybridization (D-FISH) using a LSI CBFβ inv(16) break apart probe labeled by Spectrum red and Spectrum green was performed in 15 acute myeloid leukemia cases, including 13 cases with or without abnormal eosinophils but with positive core binding factor β (CBFβ)-MYH11 fusion transcript detected by RT-PCR, and 2 cases with trisomy 8 (+8). The results were compared with the morphology, immunophenotype, karyotype and RT-PCR. Morphologically, 12 cases were diagnosed as M(4)EO, 2 as M(4), and 1 as M(2a). Immunophenotypically, all 13 AML cases with inv(16) showed positive expression of CD(13) and CD(33), but without the expression of any lymphoid lineage antigens. Karyotyping analysis with G-banding detected inv(16) in 10 AML cases, including 9 M(4)EO cases and 1 M(2a), but only 5 positive cases were detected using R-banding technique. Among them, 2 cases had simultaneous +8 and trisomy22 (+22), one had +22 only in addition to inv(16). D-FISH revealed a CBFβ-MYH11 rearrangement in 13 cases of AML with positive RT-PCR results, and the mean positive rate of cell detection was 55.15% (range 37.0% - 86.0%). The complete remission rate (CR) and median survival period in this series of inv(16) AML were 81.5%and 11 months, respectively, of whom, 8 cases were still in CR. Relapse and karyotypic evolution were seen in case 5 with +8, +22 in addition to inv(16). AML with inv(16) is a special subtype. Most cases belong to M(4)EO. Its prognosis is good in general, but it seems to be an unfavorable feature for AML with inv(16) and +8, +22 simultaneously, especially with karyotypic evolution. For detection of inv(16), G-banding technique is evidently superior to R-banding technique. D-FISH combined with RT-PCR are more sensitive and reliable than chromosome banding analysis.

High-temperature two-dimensional liquid chromatography of ethylene-vinylacetate copolymers.

PubMed

Ginzburg, Anton; Macko, Tibor; Dolle, Volker; Brüll, Robert

2010-10-29

Temperature rising elution fractionation hyphenated to size exclusion chromatography (TREF×SEC) is a routine technique to determine the chemical heterogeneity of semicrystalline olefin copolymers. Its applicability is limited to well crystallizing samples. High-temperature two-dimensional liquid chromatography, HT 2D-LC, where the chromatographic separation by HPLC is hyphenated to SEC (HPLC×SEC) holds the promise to separate such materials irrespective of their crystallizability. A model blend consisting of ethylene-vinyl acetate (EVA) copolymers covering a broad range of chemical composition distribution including amorphous and semicrystalline copolymers and a polyethylene standard was separated by HT 2D-LC at 140°C. Both axes of the contour plot, i.e. the compositional axis from the HPLC and the molar mass axis from the SEC separation were calibrated for the first time. Therefore, a new approach to determine the void and dwell volume of the developed HT 2D-LC instrument was applied. The results from the HT 2D-LC separation are compared to those from a cross-fractionation (TREF×SEC) experiment. Copyright © 2010. Published by Elsevier B.V.

Two-Dimensional Si-Nanodisk Array Fabricated Using Bio-Nano-Process and Neutral Beam Etching for Realistic Quantum Effect Devices

NASA Astrophysics Data System (ADS)

Huang, Chi-Hsien; Igarashi, Makoto; Woné, Michel; Uraoka, Yukiharu; Fuyuki, Takashi; Takeguchi, Masaki; Yamashita, Ichiro; Samukawa, Seiji

2009-04-01

A high-density, large-area, and uniform two-dimensional (2D) Si-nanodisk array was successfully fabricated using the bio-nano-process, advanced etching techniques, including a treatment using nitrogen trifluoride and hydrogen radical (NF3 treatment) and a damage-free chlorine neutral beam (NB). By using the surface oxide formed by neutral beam oxidation (NBO) for the preparation of a 2D nanometer-sized iron core array as an etching mask, a well-ordered 2D Si-nanodisk array was obtained owing to the dangling bonds of the surface oxide. By changing the NF3 treatment time without changing the quantum effect of each nanodisk, we could control the gap between adjacent nanodisks. A device with two electrodes was fabricated to investigate the electron transport in a 2D Si-nanodisk array. Current fluctuation and time-dependent currents were clearly observed owing to the charging-discharging of the nanodisks adjacent to the current percolation path. The new structure may have great potential for future novel quantum effect devices.

Comparison of three-dimensional particle tracking and sizing using plenoptic imaging and digital in-line holography

DOE PAGES

Hall, Elise M.; Thurow, Brian S.; Guildenbecher, Daniel R.

2016-08-08

Digital in-line holography (DIH) and plenoptic photography are two techniques for single-shot, volumetric measurement of 3D particle fields. Here we present a comparison of the two methods by applying plenoptic imaging to experimental configurations that have been previously investigated with DIH. These experiments include the tracking of secondary droplets from the impact of a water drop on a thin film of water and tracking of pellets from a shotgun. Both plenoptic imaging and DIH successfully quantify the 3D nature of these particle fields. Furthermore, this includes measurement of the 3D particle position, individual particle sizes, and three-component velocity vectors. Formore » the initial processing methods presented here, both techniques give out-of-plane positional accuracy of approximately 1–2 particle diameters. For a fixed image sensor, digital holography achieves higher effective in-plane spatial resolutions. However, collimated and coherent illumination makes holography susceptible to image distortion through index of refraction gradients, as demonstrated in the shotgun experiments. In contrast, plenoptic imaging allows for a simpler experimental configuration and, due to the use of diffuse, white-light illumination, plenoptic imaging is less susceptible to image distortion in the shotgun experiments.« less

Two-dimensional strain-mapping by electron backscatter diffraction and confocal Raman spectroscopy

NASA Astrophysics Data System (ADS)

Gayle, Andrew J.; Friedman, Lawrence H.; Beams, Ryan; Bush, Brian G.; Gerbig, Yvonne B.; Michaels, Chris A.; Vaudin, Mark D.; Cook, Robert F.

2017-11-01

The strain field surrounding a spherical indentation in silicon is mapped in two dimensions (2-D) using electron backscatter diffraction (EBSD) cross-correlation and confocal Raman spectroscopy techniques. The 200 mN indentation created a 4 μm diameter residual contact impression in the silicon (001) surface. Maps about 50 μm × 50 μm area with 128 pixels × 128 pixels were generated in several hours, extending, by comparison, assessment of the accuracy of both techniques to mapping multiaxial strain states in 2-D. EBSD measurements showed a residual strain field dominated by in-surface normal and shear strains, with alternating tensile and compressive lobes extending about three to four indentation diameters from the contact and exhibiting two-fold symmetry. Raman measurements showed a residual Raman shift field, dominated by positive shifts, also extending about three to four indentation diameters from the contact but exhibiting four-fold symmetry. The 2-D EBSD results, in combination with a mechanical-spectroscopic analysis, were used to successfully predict the 2-D Raman shift map in scale, symmetry, and shift magnitude. Both techniques should be useful in enhancing the reliability of microelectromechanical systems (MEMS) through identification of the 2-D strain fields in MEMS devices.

Label-free genotyping of cytochrome P450 2D6*10 using ligation-mediated strand displacement amplification with DNAzyme-based chemiluminescence detection.

PubMed

Wang, Hong-Qi; Wu, Zhan; Zhang, Yan; Tang, Li-Juan; Yu, Ru-Qin; Jiang, Jian-Hui

2012-01-13

Genotyping of cytochrome P450 monooxygenase 2D6*10 (CYP2D6*10) plays an important role in pharmacogenomics, especially in clinical drug therapy of Asian populations. This work reported a novel label-free technique for genotyping of CYP2D6*10 based on ligation-mediated strand displacement amplification (SDA) with DNAzyme-based chemiluminescence detection. Discrimination of single-base mismatch is firstly accomplished using DNA ligase to generate a ligation product. The ligated product then initiates a SDA reaction to produce aptamer sequences against hemin, which can be probed by chemiluminescence detection. The proposed strategy is used for the assay of CYP2D6*10 target and the genomic DNA. The results reveal that the proposed technique displays chemiluminescence responses in linear correlation to the concentrations of DNA target within the range from 1 pM to 1 nM. A detection limit of 0.1 pM and a signal-to-background ratio of 57 are achieved. Besides such high sensitivity, the proposed CYP2D6*10 genotyping strategy also offers superb selectivity, great robustness, low cost and simplified operations due to its label-free, homogeneous, and chemiluminescence-based detection format. These advantages suggest this technique may hold considerable potential for clinical CYP2D6*10 genotyping and association studies. Copyright © 2011 Elsevier B.V. All rights reserved.

Enhanced visualization of MR angiogram with modified MIP and 3D image fusion

NASA Astrophysics Data System (ADS)

Kim, JongHyo; Yeon, Kyoung M.; Han, Man Chung; Lee, Dong Hyuk; Cho, Han I.

1997-05-01

We have developed a 3D image processing and display technique that include image resampling, modification of MIP, volume rendering, and fusion of MIP image with volumetric rendered image. This technique facilitates the visualization of the 3D spatial relationship between vasculature and surrounding organs by overlapping the MIP image on the volumetric rendered image of the organ. We applied this technique to a MR brain image data to produce an MRI angiogram that is overlapped with 3D volume rendered image of brain. MIP technique was used to visualize the vasculature of brain, and volume rendering was used to visualize the other structures of brain. The two images are fused after adjustment of contrast and brightness levels of each image in such a way that both the vasculature and brain structure are well visualized either by selecting the maximum value of each image or by assigning different color table to each image. The resultant image with this technique visualizes both the brain structure and vasculature simultaneously, allowing the physicians to inspect their relationship more easily. The presented technique will be useful for surgical planning for neurosurgery.

Tomographic phase microscopy and its biological applications

NASA Astrophysics Data System (ADS)

Choi, Wonshik

2012-12-01

Conventional interferometric microscopy techniques such as digital holographic microscopy and quantitative phase microscopy are often classified as 3D imaging techniques because a recorded complex field image can be numerically propagated to a different depth. In a strict sense, however, a single complex field image contains only 2D information on a specimen. The measured 2D image is only a subset of the 3D structure. For the 3D mapping of an object, multiple independent 2D images are to be taken, for example at multiple incident angles or wavelengths, and then combined by the so-called optical diffraction tomography (ODT). In this Letter, tomographic phase microscopy (TPM) is reviewed that experimentally realizes the concept of the ODT for the 3D mapping of biological cells in their native state, and some of its interesting biological and biomedical applications are introduced. [Figure not available: see fulltext.

Molecular orbital study of some eight-coordinate sulfur chelate complexes of molybdenum

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

Perkins, P.G.; Schultz, F.A.

1983-03-30

A number of molybdenum complexes involving the formal oxidation states Mo(IV) and Mo(V) have been studied by a self-consistent-field molecular orbital technique. All the complexes were of dodecahedral geometry and had eight sulfurs chelated to the central metal atom. In all, a series of five tetrakis complexes was studied, including the ligands dithiocarbamate (dtc), thioxanthate (txn), 1,1-dicyano-2,2-ethylenedithiolate (i-mnt), 1-cyano-1-carbethoxy-2,2-ethylenedithiolate (ced), and 1,1-dicarbethoxy-2,2-ethylenedithiolate (ded). The 4d orbitals were included on molybdenum, and the empty 3d levels on all sulfur atoms. The results show that the highest occupied molecular orbital in each case has over 90% metal d/sub xy/ character. Further, themore » energy of this orbital is linearly related to the reversible half-wave potentials for Mo(IV) ..-->.. Mo(V) and Mo(V) ..-->.. Mo(VI) oxidations of the complexes. A further irreversible oxidation observed experimentally also is closely related to the calculated energy levels. Relationships between the calculated results and Mo 3d/sub 5///sub 2/ X-ray photoelectron binding energies, EPR parameters, and charge-transfer absorption energies are discussed. Electrochemical and spectroscopic properties of these MoS/sub 8/ complexes can be understood in terms of a manifold of orbital energies that retain approximately constant spacings between one another and that move up or down in absolute energy in response to the charge donated or withdrawn by the ligands.« less

[Morphological and functional cartilage imaging].

PubMed

Rehnitz, C; Weber, M-A

2014-06-01

Excellent morphological imaging of cartilage is now possible and allows the detection of subtle cartilage pathologies. Besides the standard 2D sequences, a multitude of 3D sequences are available for high-resolution cartilage imaging. The first part therefore deals with modern possibilities of morphological imaging. The second part deals with functional cartilage imaging with which it is possible to detect changes in cartilage composition and thus early osteoarthritis as well as to monitor biochemical changes after therapeutic interventions. Validated techniques such as delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) and T2 mapping as well the latest techniques, such as the glycosaminoglycan chemical exchange-dependent saturation transfer (gagCEST) technique will be discussed.

[Morphological and functional cartilage imaging].

PubMed

Rehnitz, C; Weber, M-A

2015-04-01

Excellent morphological imaging of cartilage is now possible and allows the detection of subtle cartilage pathologies. Besides the standard 2D sequences, a multitude of 3D sequences are available for high-resolution cartilage imaging. The first part therefore deals with modern possibilities of morphological imaging. The second part deals with functional cartilage imaging with which it is possible to detect changes in cartilage composition and thus early osteoarthritis as well as to monitor biochemical changes after therapeutic interventions. Validated techniques such as delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) and T2 mapping as well the latest techniques, such as the glycosaminoglycan chemical exchange-dependent saturation transfer (gagCEST) technique will be discussed.

3D isotropic T2-weighted fast spin echo (VISTA) versus 2D T2-weighted fast spin echo in evaluation of the calcaneofibular ligament in the oblique coronal plane.

PubMed

Park, H J; Lee, S Y; Choi, Y J; Hong, H P; Park, S J; Park, J H; Kim, E

2017-02-01

To investigate whether the image quality of three-dimensional (3D) volume isotropic fast spin echo acquisition (VISTA) magnetic resonance imaging (MRI) of the calcaneofibular ligament (CFL) view is comparable to that of 2D fast spin echo T2-weighted images (2D T2 FSE) for the evaluation of the CFL, and whether 3D VISTA can replace 2D T2 FSE for the evaluation of CFL injuries. This retrospective study included 76 patients who underwent ankle MRI with CFL views of both 2D T2 FSE MRI and 3D VISTA. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of both techniques were measured. The anatomical identification score and diagnostic performances were evaluated by two readers independently. The diagnostic performances of 3D VISTA and 2D T2 FSE were analysed by sensitivity, specificity, and accuracy for diagnosing CFL injury with reference standards of surgically or clinically confirmed diagnoses. Surgical correlation was performed in 29% of the patients, and clinical examination was used in those who did not have surgery (71%). The SNRs and CNRs of 3D VISTA were significantly higher than those of 2D T2 FSE. The anatomical identification scores on 3D VISTA were inferior to those on 2D T2 FSE, and the differences were statistically significant (p<0.05). There were no significant differences in diagnostic performance between the two sequences when diagnoses were classified as normal or abnormal. Although the image quality of 3D VISTA MRI of the CFL view is not equal to that of 2D T2 FSE for the anatomical evaluation of CFL, 3D VISTA has a diagnostic performance comparable to that of 2D T2 FSE for the diagnosis of CFL injuries. Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Two-dimensional fringe probing of transient liquid temperatures in a mini space.

PubMed

Xue, Zhenlan; Qiu, Huihe

2011-05-01

A 2D fringe probing transient temperature measurement technique based on photothermal deflection theory was developed. It utilizes material's refractive index dependence on temperature gradient to obtain temperature information from laser deflection. Instead of single beam, this method applies multiple laser beams to obtain 2D temperature information. The laser fringe was generated with a Mach-Zehnder interferometer. A transient heating experiment was conducted using an electric wire to demonstrate this technique. Temperature field around a heating wire and variation with time was obtained utilizing the scattering fringe patterns. This technique provides non-invasive 2D temperature measurements with spatial and temporal resolutions of 3.5 μm and 4 ms, respectively. It is possible to achieve temporal resolution to 500 μs utilizing the existing high speed camera.

Investigation of rail irregularity effects on wheel/rail dynamic force in slab track: Comparison of two and three dimensional models

NASA Astrophysics Data System (ADS)

Sadeghi, Javad; Khajehdezfuly, Amin; Esmaeili, Morteza; Poorveis, Davood

2016-07-01

Rail irregularity is one of the most significant load amplification factors in railway track systems. In this paper, the capability and effectiveness of the two main railway slab tracks modeling techniques in prediction of the influences of rail irregularities on the Wheel/Rail Dynamic Force (WRDF) were investigated. For this purpose, two 2D and 3D numerical models of vehicle/discontinuous slab track interaction were developed. The validation of the numerical models was made by comparing the results of the models with those obtained from comprehensive field tests carried out in this research. The effects of the harmonic and non-harmonic rail irregularities on the WRDF obtained from 3D and 2D models were investigated. The results indicate that the difference between WRDF obtained from 2D and 3D models is negligible when the irregularities on the right and left rails are the same. However, as the difference between irregularities of the right and left rails increases, the results obtained from 2D and 3D models are considerably different. The results indicate that 2D models have limitations in prediction of WRDF; that is, a 3D modeling technique is required to predict WRDF when there is uneven or non-harmonic irregularity with large amplitudes. The size and extent of the influences of rail irregularities on the wheel/rail forces were discussed leading to provide a better understanding of the rail-wheel contact behavior and the required techniques for predicting WRDF.

A methodological evaluation of volumetric measurement techniques including three-dimensional imaging in breast surgery.

PubMed

Hoeffelin, H; Jacquemin, D; Defaweux, V; Nizet, J L

2014-01-01

Breast surgery currently remains very subjective and each intervention depends on the ability and experience of the operator. To date, no objective measurement of this anatomical region can codify surgery. In this light, we wanted to compare and validate a new technique for 3D scanning (LifeViz 3D) and its clinical application. We tested the use of the 3D LifeViz system (Quantificare) to perform volumetric calculations in various settings (in situ in cadaveric dissection, of control prostheses, and in clinical patients) and we compared this system to other techniques (CT scanning and Archimedes' principle) under the same conditions. We were able to identify the benefits (feasibility, safety, portability, and low patient stress) and limitations (underestimation of the in situ volume, subjectivity of contouring, and patient selection) of the LifeViz 3D system, concluding that the results are comparable with other measurement techniques. The prospects of this technology seem promising in numerous applications in clinical practice to limit the subjectivity of breast surgery.

A Methodological Evaluation of Volumetric Measurement Techniques including Three-Dimensional Imaging in Breast Surgery

PubMed Central

Hoeffelin, H.; Jacquemin, D.; Defaweux, V.; Nizet, J L.

2014-01-01

Breast surgery currently remains very subjective and each intervention depends on the ability and experience of the operator. To date, no objective measurement of this anatomical region can codify surgery. In this light, we wanted to compare and validate a new technique for 3D scanning (LifeViz 3D) and its clinical application. We tested the use of the 3D LifeViz system (Quantificare) to perform volumetric calculations in various settings (in situ in cadaveric dissection, of control prostheses, and in clinical patients) and we compared this system to other techniques (CT scanning and Archimedes' principle) under the same conditions. We were able to identify the benefits (feasibility, safety, portability, and low patient stress) and limitations (underestimation of the in situ volume, subjectivity of contouring, and patient selection) of the LifeViz 3D system, concluding that the results are comparable with other measurement techniques. The prospects of this technology seem promising in numerous applications in clinical practice to limit the subjectivity of breast surgery. PMID:24511536

Mathematical Modeling of Serum 13C-Retinol in Captive Rhesus Monkeys Provides New Insights on Hypervitaminosis A1–3

PubMed Central

Escaron, Anne L.; Green, Michael H.; Howe, Julie A.; Tanumihardjo, Sherry A.

2009-01-01

Hypervitaminosis A is increasingly a public health concern, and thus noninvasive quantitative methods merit exploration. In this study, we applied the 13C-retinol isotope dilution test to a nonhuman primate model with excessive liver stores. After baseline serum chemistries, rhesus macaques (Macaca mulatta; n = 16) were administered 3.5 μmol 13C2-retinyl acetate. Blood was drawn at baseline, 5 h, and 2, 4, 7, 14, 21, and 28 d following the dose. Liver biopsies were collected 7 d before and 2 d after dosing (n = 4) and at 7, 14, and 28 d (n = 4/time) after dosing. Serum and liver were analyzed by HPLC and GC-combustion-isotope ratio MS for retinol and its enrichment, respectively. Model-based compartmental analysis was applied to serum data. Lactate dehydrogenase was elevated in 50% of the monkeys. Total body reserves (TBR) of vitamin A (VA) were calculated at 28 d. Predicted TBR (3.52 ± 2.01 mmol VA) represented measured liver stores (4.56 ± 1.38 mmol VA; P = 0.124). Predicted liver VA concentrations (13.3 ± 9.7 μmol/g) were similar to measured liver VA concentrations (16.4 ± 5.3 μmol/g). The kinetic models predict that 27–52% of extravascular VA is exchanging with serum in hypervitaminotic A monkeys. The test correctly diagnosed hypervitaminosis A in all monkeys, i.e. 100% sensitivity. Stable isotope techniques have important public health potential for the classification of VA status, including hypervitaminosis, because no other technique besides invasive liver biopsies, correctly identifies excessive liver VA stores. PMID:19710158

Why 1D electrical resistivity techniques can result in inaccurate siting of boreholes in hard rock aquifers and why electrical resistivity tomography must be preferred: the example of Benin, West Africa

NASA Astrophysics Data System (ADS)

Alle, Iboukoun Christian; Descloitres, Marc; Vouillamoz, Jean-Michel; Yalo, Nicaise; Lawson, Fabrice Messan Amen; Adihou, Akonfa Consolas

2018-03-01

Hard rock aquifers are of particular importance for supplying people with drinking water in Africa and in the world. Although the common use of one-dimensional (1D) electrical resistivity techniques to locate drilling site, the failure rate of boreholes is usually high. For instance, about 40% of boreholes drilled in hard rock aquifers in Benin are unsuccessful. This study investigates why the current use of 1D techniques (e.g. electrical profiling and electrical sounding) can result in inaccurate siting of boreholes, and checks the interest and the limitations of the use of two-dimensional (2D) Electrical Resistivity Tomography (ERT). Geophysical numerical modeling and comprehensive 1D and 2D resistivity surveys were carried out in hard rock aquifers in Benin. The experiments carried out at 7 sites located in different hard rock groups confirmed the results of the numerical modeling: the current use of 1D techniques can frequently leads to inaccurate siting, and ERT better reveals hydrogeological targets such as thick weathered zone (e.g. stratiform fractured layer and preferential weathering associated with subvertical fractured zone). Moreover, a cost analysis demonstrates that the use of ERT can save money at the scale of a drilling programme if ERT improves the success rate by only 5% as compared to the success rate obtained with 1D techniques. Finally, this study demonstrates, using the example of Benin, that the use of electrical resistivity profiling and sounding for siting boreholes in weathered hard rocks of western Africa should be discarded and replaced by the use of ERT technique, more efficient.

In Situ 3D Coherent X-ray Diffraction Imaging of Shock Experiments: Possible?

NASA Astrophysics Data System (ADS)

Barber, John

2011-03-01

In traditional coherent X-ray diffraction imaging (CXDI), a 2D or quasi-2D object is illuminated by a beam of coherent X-rays to produce a diffraction pattern, which is then manipulated via a process known as iterative phase retrieval to reconstruct an image of the original 2D sample. Recently, there have been dramatic advances in methods for performing fully 3D CXDI of a sample from a single diffraction pattern [Raines et al, Nature 463 214-7 (2010)], and these methods have been used to image samples tens of microns in size using soft X-rays. In this work, I explore the theoretical possibility of applying 3D CXDI techniques to the in situ imaging of the interaction between a shock front and a polycrystal, a far more stringent problem. A delicate trade-off is required between photon energy, spot size, imaging resolution, and the dimensions of the experimental setup. In this talk, I will outline the experimental and computational requirements for performing such an experiment, and I will present images and movies from simulations of one such hypothetical experiment, including both the time-resolved X-ray diffraction patterns and the time-resolved sample imagery.

Solid oxide fuel cell simulation and design optimization with numerical adjoint techniques

NASA Astrophysics Data System (ADS)

Elliott, Louie C.

This dissertation reports on the application of numerical optimization techniques as applied to fuel cell simulation and design. Due to the "multi-physics" inherent in a fuel cell, which results in a highly coupled and non-linear behavior, an experimental program to analyze and improve the performance of fuel cells is extremely difficult. This program applies new optimization techniques with computational methods from the field of aerospace engineering to the fuel cell design problem. After an overview of fuel cell history, importance, and classification, a mathematical model of solid oxide fuel cells (SOFC) is presented. The governing equations are discretized and solved with computational fluid dynamics (CFD) techniques including unstructured meshes, non-linear solution methods, numerical derivatives with complex variables, and sensitivity analysis with adjoint methods. Following the validation of the fuel cell model in 2-D and 3-D, the results of the sensitivity analysis are presented. The sensitivity derivative for a cost function with respect to a design variable is found with three increasingly sophisticated techniques: finite difference, direct differentiation, and adjoint. A design cycle is performed using a simple optimization method to improve the value of the implemented cost function. The results from this program could improve fuel cell performance and lessen the world's dependence on fossil fuels.

[Evaluation of visual stimulation combined with intracavernous injections for the treatment of severe erectile dysfunction].

PubMed

Galiano, Marc; Rouprêt, Morgan; Beley, Sébastien; Gattegno, Bernard; Chartier-Kastler, Emmanuel; Richard, François

2007-04-01

To assess the value of visual sexual stimulation combined with intracavernous injections (ICI) in patients treated for severe erectile dysfunction. All patients with severe erectile dysfunction were prospectively included in this study between 2005 and 2006. The outpatient protocol consisted of comparing the efficacy of alprostadil ICI alone on D0 and ICI combined with erotic stimulation on D8. End-points were: time to onset and rigidity of erection. A subjective score (1 to 5) was used to quantify erection. Forty patients with a mean age of 64.5 years (range: 52-70 years) were included in the study. All patients had an IIEF5 score less than 15. Erectile dysfunction was secondary to urological surgery in 35% of cases. The mean time to onset of erection was 10 min 18 s (range: 2-20 min) on D0 and 10 min 50 s (range: 2-20 min) on D8. No significant difference for rigidity and quality of erection was observed between D0 and D8 and erections were scored as 5 in 30 cases (75%), 4 in 8 cases (20%) and 3 in 2 cases (5%) at each visit. Visual sexual stimulation has not been demonstrated to be truly effective in the hospital setting in combination with intracavernous injections. In order to increase the patient satisfaction rate, the urologist must above all educate the patient in the intracavernous injection technique in an appropriate environment.

O(1D) kinetic study of key ozone depleting substances and greenhouse gases.

PubMed

Baasandorj, Munkhbayar; Fleming, Eric L; Jackman, Charles H; Burkholder, James B

2013-03-28

A key stratospheric loss process for ozone depleting substances (ODSs) and greenhouse gases (GHGs) is reaction with the O((1)D) atom. In this study, rate coefficients, k, for the O((1)D) atom reaction were measured for the following key halocarbons: chlorofluorocarbons (CFCs) CFCl3 (CFC-11), CF2Cl2 (CFC-12), CFCl2CF2Cl (CFC-113), CF2ClCF2Cl (CFC-114), CF3CF2Cl (CFC-115); hydrochlorofluorocarbons (HCFCs) CHF2Cl (HCFC-22), CH3CClF2 (HCFC-142b); and hydrofluorocarbons (HFCs) CHF3 (HFC-23), CHF2CF3 (HFC-125), CH3CF3 (HFC-143a), and CF3CHFCF3 (HFC-227ea). Total rate coefficients, kT, corresponding to the loss of the O((1)D) atom, were measured over the temperature range 217-373 K using a competitive reactive technique. kT values for the CFC and HCFC reactions were >1 × 10(-10) cm(3) molecule(-1) s(-1), except for CFC-115, and the rate coefficients for the HFCs were in the range (0.095-0.72) × 10(-10) cm(3) molecule(-1) s(-1). Rate coefficients for the CFC-12, CFC-114, CFC-115, HFC-23, HFC-125, HFC-143a, and HFC-227ea reactions were observed to have a weak negative temperature dependence, E/R ≈ -25 K. Reactive rate coefficients, kR, corresponding to the loss of the halocarbon, were measured for CFC-11, CFC-115, HCFC-22, HCFC-142b, HFC-23, HFC-125, HFC-143a, and HFC-227ea using a relative rate technique. The reactive branching ratio obtained was dependent on the composition of the halocarbon and the trend in O((1)D) reactivity with the extent of hydrogen and chlorine substitution is discussed. The present results are critically compared with previously reported kinetic data and the discrepancies are discussed. 2D atmospheric model calculations were used to evaluate the local and global annually averaged atmospheric lifetimes of the halocarbons and the contribution of O((1)D) chemistry to their atmospheric loss. The O((1)D) reaction was found to be a major global loss process for CFC-114 and CFC-115 and a secondary global loss process for the other molecules included in this study.

Application of 5-bromo-2'deoxyuridine as a label for in situ hybridization in chromosome microdissection and painting, and 3' OH DNA end labeling for apoptosis.

PubMed

Mühlmann-Díaz, M C; Dullea, R G; Bedford, J S

1996-07-01

We have utilized 5-bromo-2'deoxyuridine (BrdU) substituted DNA as a probe for a number of applications including, principally, for chromosome painting by fluorescence in situ hybridization (FISH) but also for DNA end-labeling to detect apoptotic cell death and for filter hybridization. Br-dUTP was used as a substitute for biotin or digoxigenin-dUTP in probe labeling techniques, such as random priming, nick translation, end-labeling or PCR. An especially useful application is that it may be incorporated into probe DNA while cells or plasmids in bacteria are growing in the presence of BrdU. This can be particularly advantageous when large quantities of probe are needed, since the cost per mole of digoxigenin-dUTP or biotin-dUTP is nearly 1000 times that of Br-dUTP. Also, if probe is prepared by growth in BrdU, the difference in cost to prepare equal quantities of labeled DNA is more than 10,000 times greater for biotin-dUTP.

3D Fiber Orientation Simulation for Plastic Injection Molding

NASA Astrophysics Data System (ADS)

Lin, Baojiu; Jin, Xiaoshi; Zheng, Rong; Costa, Franco S.; Fan, Zhiliang

2004-06-01

Glass fiber reinforced polymer is widely used in the products made using injection molding processing. The distribution of fiber orientation inside plastic parts has direct effects on quality of molded parts. Using computer simulation to predict fiber orientation distribution is one of most efficient ways to assist engineers to do warpage analysis and to find a good design solution to produce high quality plastic parts. Fiber orientation simulation software based on 2-1/2D (midplane /Dual domain mesh) techniques has been used in industry for a decade. However, the 2-1/2D technique is based on the planar Hele-Shaw approximation and it is not suitable when the geometry has complex three-dimensional features which cannot be well approximated by 2D shells. Recently, a full 3D simulation software for fiber orientation has been developed and integrated into Moldflow Plastics Insight 3D simulation software. The theory for this new 3D fiber orientation calculation module is described in this paper. Several examples are also presented to show the benefit in using 3D fiber orientation simulation.

Large Area 2D and 3D Colloidal Photonic Crystals Fabricated by a Roll-to-Roll Langmuir-Blodgett Method.

PubMed

Parchine, Mikhail; McGrath, Joe; Bardosova, Maria; Pemble, Martyn E

2016-06-14

We present our results on the fabrication of large area colloidal photonic crystals on flexible poly(ethylene terephthalate) (PET) film using a roll-to-roll Langmuir-Blodgett technique. Two-dimensional (2D) and three-dimensional (3D) colloidal photonic crystals from silica nanospheres (250 and 550 nm diameter) with a total area of up to 340 cm(2) have been fabricated in a continuous manner compatible with high volume manufacturing. In addition, the antireflective properties and structural integrity of the films have been enhanced via the use of a second roll-to-roll process, employing a slot-die coating of an optical adhesive over the photonic crystal films. Scanning electron microscopy images, atomic force microscopy images, and UV-vis optical transmission and reflection spectra of the fabricated photonic crystals are analyzed. This analysis confirms the high quality of the 2D and 3D photonic crystals fabricated by the roll-to-roll LB technique. Potential device applications of the large area 2D and 3D colloidal photonic crystals on flexible PET film are briefly reviewed.

SU-E-T-548: How To Decrease Spine Dose In Patients Who Underwent Sterotactic Spine Radiosurgery?

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

Acar, H; Altinok, A; Kucukmorkoc, E

2014-06-01

Purpose: Stereotactic radiosurgery for spine metastases involves irradiation using a single high dose fraction. The purpose of this study was to dosimetrically compare stereotactic spine radiosurgery(SRS) plans using a recently new volumetric modulated arc therapy(VMAT) technique against fix-field intensity-modulated radiotherapy(IMRT). Plans were evaluated for target conformity and spinal cord sparing. Methods: Fifteen previously treated patients were replanned using the Eclipse 10.1 TPS AAA calculation algorithm. IMRT plans with 7 fields were generated. The arc plans used 2 full arc configurations. Arc and IMRT plans were normalized and prescribed to deliver 16.0 Gy in a single fraction to 90% of themore » planning target volume(PTV). PTVs consisted of the vertebral body expanded by 3mm, excluding the PRV-cord, where the cord was expanded by 2mm.RTOG 0631 recommendations were applied for treatment planning. Partial spinal cord volume was defined as 5mm above and below the radiosurgery target volume. Plans were compared for conformity and gradient index as well as spinal cord sparing. Results: The conformity index values of fifteen patients for two different treatment planning techniques were shown in table 1. Conformity index values for 2 full arc planning (average CI=0.84) were higher than that of IMRT planning (average CI=0.79). The gradient index values of fifteen patients for two different treatment planning techniques were shown in table 2. Gradient index values for 2 full arc planning (average GI=3.58) were higher than that of IMRT planning (average GI=2.82).The spinal cord doses of fifteen patients for two different treatment planning techniques were shown in table 3. D0.35cc, D0.03cc and partial spinal cord D10% values in 2 full arc plannings (average D0.35cc=819.3cGy, D0.03cc=965.4cGy, 10%partial spinal=718.1cGy) were lower than IMRT plannings (average D0.35cc=877.4cGy, D0.03c=1071.4cGy, 10%partial spinal=805.1cGy). Conclusions: The two arc VMAT technique is superior to 7 field IMRT technique in terms of both spinal cord sparing and better conformity and gradient indexes.« less

MO-G-BRD-01: Point/Counterpoint Debate: Arc Based Techniques Will Make Conventional IMRT Obsolete

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

Shepard, D; Popple, R; Balter, P

2014-06-15

A variety of intensity modulated radiation therapy (IMRT) delivery techniques have been developed that have provided clinicians with the ability to deliver highly conformal dose distributions. The delivery techniques include compensators, step-and-shoot IMRT, sliding window IMRT, volumetric modulated arc therapy (VMAT), and tomotherapy. A key development in the field of IMRT was the introduction of new planning algorithms and delivery control systems in 2007 that made it possible to coordinate the gantry rotation speed, dose rate, and multileaf collimator leaf positions during the delivery of arc therapy. With these developments, VMAT became a routine clinical tool. The use of VMATmore » has continued to grow in recent years and some would argue that this will soon make conventional IMRT obsolete, and this is the premise of this debate. To introduce the debate, David Shepard, Ph.D. will provide an overview of IMRT delivery techniques including historical context and how they are being used today. The debate will follow with Richard Popple, Ph.D. arguing FOR the Proposition and Peter Balter, Ph.D. arguing AGAINST it. Learning Objectives: Understand the different delivery techniques for IMRT. Understand the potential benefits of conventional IMRT. Understand the potential benefits of arc-based IMRT delivery.« less

Environment dependent enhanced photoluminescence and Boolean logic gates like behavior of Bi2O3 and Ag:Bi2O3 nanostructures

NASA Astrophysics Data System (ADS)

Hariharan, S.; Karthikeyan, B.

2018-03-01

In the evolution of nanotechnology research for smart and precise sensor fabrication, here we report the implementation of simple logic gate operations performing by luminescent nanostructures in biomolecule environment based on photoluminescence (PL) technique. This present work deals with the luminescence property of α-Bi2O3 and Ag modified α-Bi2O3 nanostructures for D-glucose and Bovine serum albumin (BSA) sensing applications. These nanostructures are prepared by simple co-precipitation method and their morphology are examined using transmission electron microscope (TEM). We explore the PL characteristics of the prepared nanostructures and observe their change in PL intensity in the presence of D-glucose and BSA molecules. Enhancement in PL intensity is observed in the presence of D-glucose and BSA. Based on the PL response of prepared nanostructures in the biomolecule environment, we demonstrate biophotonic logic gates including YES, PASS 0, OR and INHIBIT gates.

Remote sensing of surface currents with single shipborne high-frequency surface wave radar

NASA Astrophysics Data System (ADS)

Wang, Zhongbao; Xie, Junhao; Ji, Zhenyuan; Quan, Taifan

2016-01-01

High-frequency surface wave radar (HFSWR) is a useful technology for remote sensing of surface currents. It usually requires two (or more) stations spaced apart to create a two-dimensional (2D) current vector field. However, this method can only obtain the measurements within the overlapping coverage, which wastes most of the data from only one radar observation. Furthermore, it increases observation's costs significantly. To reduce the number of required radars and increase the ocean area that can be measured, this paper proposes an economical methodology for remote sensing of the 2D surface current vector field using single shipborne HFSWR. The methodology contains two parts: (1) a real space-time multiple signal classification (MUSIC) based on sparse representation and unitary transformation techniques is developed for measuring the radial currents from the spreading first-order spectra, and (2) the stream function method is introduced to obtain the 2D surface current vector field. Some important conclusions are drawn, and simulations are included to validate the correctness of them.

Effects of blurring and vertical misalignment on visual fatigue of stereoscopic displays

NASA Astrophysics Data System (ADS)

Baek, Sangwook; Lee, Chulhee

2015-03-01

In this paper, we investigate two error issues in stereo images, which may produce visual fatigue. When two cameras are used to produce 3D video sequences, vertical misalignment can be a problem. Although this problem may not occur in professionally produced 3D programs, it is still a major issue in many low-cost 3D programs. Recently, efforts have been made to produce 3D video programs using smart phones or tablets, which may present the vertical alignment problem. Also, in 2D-3D conversion techniques, the simulated frame may have blur effects, which can also introduce visual fatigue in 3D programs. In this paper, to investigate the relationship between these two errors (vertical misalignment and blurring in one image), we performed a subjective test using simulated 3D video sequences that include stereo video sequences with various vertical misalignments and blurring in a stereo image. We present some analyses along with objective models to predict the degree of visual fatigue from vertical misalignment and blurring.

Effect of Shear Deformation and Continuity on Delamination Modelling with Plate Elements

NASA Technical Reports Server (NTRS)

Glaessgen, E. H.; Riddell, W. T.; Raju, I. S.

1998-01-01

The effects of several critical assumptions and parameters on the computation of strain energy release rates for delamination and debond configurations modeled with plate elements have been quantified. The method of calculation is based on the virtual crack closure technique (VCCT), and models that model the upper and lower surface of the delamination or debond with two-dimensional (2D) plate elements rather than three-dimensional (3D) solid elements. The major advantages of the plate element modeling technique are a smaller model size and simpler geometric modeling. Specific issues that are discussed include: constraint of translational degrees of freedom, rotational degrees of freedom or both in the neighborhood of the crack tip; element order and assumed shear deformation; and continuity of material properties and section stiffness in the vicinity of the debond front, Where appropriate, the plate element analyses are compared with corresponding two-dimensional plane strain analyses.

Structure elucidation of organic compounds from natural sources using 1D and 2D NMR techniques

NASA Astrophysics Data System (ADS)

Topcu, Gulacti; Ulubelen, Ayhan

2007-05-01

In our continuing studies on Lamiaceae family plants including Salvia, Teucrium, Ajuga, Sideritis, Nepeta and Lavandula growing in Anatolia, many terpenoids, consisting of over 50 distinct triterpenoids and steroids, and over 200 diterpenoids, several sesterterpenoids and sesquiterpenoids along with many flavonoids and other phenolic compounds have been isolated. For Salvia species abietanes, for Teucrium and Ajuga species neo-clerodanes for Sideritis species ent-kaurane diterpenes are characteristic while nepetalactones are specific for Nepeta species. In this review article, only some interesting and different type of skeleton having constituents, namely rearranged, nor- or rare diterpenes, isolated from these species will be presented. For structure elucidation of these natural diterpenoids intensive one- and two-dimensional NMR techniques ( 1H, 13C, APT, DEPT, NOE/NOESY, 1H- 1H COSY, HETCOR, COLOC, HMQC/HSQC, HMBC, SINEPT) were used besides mass and some other spectroscopic methods.

Electron Tomography: A Three-Dimensional Analytic Tool for Hard and Soft Materials Research.

PubMed

Ercius, Peter; Alaidi, Osama; Rames, Matthew J; Ren, Gang

2015-10-14

Three-dimensional (3D) structural analysis is essential to understand the relationship between the structure and function of an object. Many analytical techniques, such as X-ray diffraction, neutron spectroscopy, and electron microscopy imaging, are used to provide structural information. Transmission electron microscopy (TEM), one of the most popular analytic tools, has been widely used for structural analysis in both physical and biological sciences for many decades, in which 3D objects are projected into two-dimensional (2D) images. In many cases, 2D-projection images are insufficient to understand the relationship between the 3D structure and the function of nanoscale objects. Electron tomography (ET) is a technique that retrieves 3D structural information from a tilt series of 2D projections, and is gradually becoming a mature technology with sub-nanometer resolution. Distinct methods to overcome sample-based limitations have been separately developed in both physical and biological science, although they share some basic concepts of ET. This review discusses the common basis for 3D characterization, and specifies difficulties and solutions regarding both hard and soft materials research. It is hoped that novel solutions based on current state-of-the-art techniques for advanced applications in hybrid matter systems can be motivated. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electron Tomography: A Three-Dimensional Analytic Tool for Hard and Soft Materials Research

PubMed Central

Alaidi, Osama; Rames, Matthew J.

2016-01-01

Three-dimensional (3D) structural analysis is essential to understand the relationship between the structure and function of an object. Many analytical techniques, such as X-ray diffraction, neutron spectroscopy, and electron microscopy imaging, are used to provide structural information. Transmission electron microscopy (TEM), one of the most popular analytic tools, has been widely used for structural analysis in both physical and biological sciences for many decades, in which 3D objects are projected into two-dimensional (2D) images. In many cases, 2D-projection images are insufficient to understand the relationship between the 3D structure and the function of nanoscale objects. Electron tomography (ET) is a technique that retrieves 3D structural information from a tilt series of 2D projections, and is gradually becoming a mature technology with sub-nanometer resolution. Distinct methods to overcome sample-based limitations have been separately developed in both physical and biological science, although they share some basic concepts of ET. This review discusses the common basis for 3D characterization, and specifies difficulties and solutions regarding both hard and soft materials research. It is hoped that novel solutions based on current state-of-the-art techniques for advanced applications in hybrid matter systems can be motivated. PMID:26087941

A Measurement of the νμ Charged Current Quasielastic Cross-section on Water with T2K's Near Detector

NASA Astrophysics Data System (ADS)

Yuan, Tianlu; Lopez, Jeremy; Marino, Alysia; T2K Collaboration

2015-04-01

The T2K experiment has collected an impressive amount of data the past few years useful for both oscillation analyses and precision measurements. Its near-detector, ND280, comprising of several sub-detectors, include water targets that allow for the extraction of a water-based cross-section measurement. We present a selection of νμ charged current events occurring within the Pi-Zero Detector (PØD). The charged, outgoing tracks are required to enter and be identified by the Tracker of T2K's near-detector. Our sample corresponds to approximately 6 × 1020 protons on target. The cross section is determined using an iterative Baysian unfolding technique, which includes all systematic uncertainties. By separating the dataset into time periods when the PØD is filled with water and when it is empty, a subtraction method provides a distribution of νμ interactions on water only. In this way, we produce a measurement of the νμ CCQE cross-section on water.

An overview of optical diagnostics developed for the Lockheed Martin compact fusion reactor

NASA Astrophysics Data System (ADS)

Sommers, Bradley; Raymond, Anthony; Gucker, Sarah; Lockheed Martin Compact Fusion Reactor Team

2017-10-01

The T4B experiment is a linear, encapsulated ring cusp confinement device, designed to develop a physics and technology basis for a follow-on high beta machine as part of the compact fusion reactor program. Toward this end, a collection of non-invasive optical diagnostics have been developed to investigate confinement, neutral beam heating, and source behavior on the T4B device. These diagnostics include: (1) a multipoint Thomson scattering system employing a 532 nm Nd:YAG laser and high throughput spectrometer to measure 1D profiles of electron density and temperature, (2) a dispersion interferometer utilizing a continuous-wave CO2 laser (10.6 μm) to measure time resolved, line-integrated electron density, and (3) a bolometer suite utilizing four AXUV photodiodes with 64 lines of sight to generate 2D reconstructions of total radiative power and soft x-ray emission (via beryllium filters). An overview of design methods, including laser systems, detection schemes, and data analysis techniques is presented as well as results to date.

High power-efficient asynchronous SAR ADC for IoT devices

NASA Astrophysics Data System (ADS)

Zhang, Beichen; Yao, Bingbing; Liu, Liyuan; Liu, Jian; Wu, Nanjian

2017-10-01

This paper presents a power-efficient 100-MS/s, 10-bit asynchronous successive approximation register (SAR) ADC. It includes an on-chip reference buffer and the total power dissipation is 6.8 mW. To achieve high performance with high power-efficiency in the proposed ADC, bootstrapped switch, redundancy, set-and-down switching approach, dynamic comparator and dynamic logic techniques are employed. The prototype was fabricated using 65 nm standard CMOS technology. At a 1.2-V supply and 100 MS/s, the ADC achieves an SNDR of 56.2 dB and a SFDR of 65.1 dB. The ADC core consumes only 3.1 mW, resulting in a figure of merit (FOM) of 30.27 fJ/conversionstep and occupies an active area of only 0.009 mm2.

Cytotoxic steroids from the leaves of Dysoxylum binectariferum.

PubMed

Yan, Hui-Jiao; Wang, Jun-Song; Kong, Ling-Yi

2014-08-01

Four new cholestane-type (1-4) and two new ergostane-type (5, 6) steroids were isolated from the leaves of Dysoxylum binectariferum. Their structures were elucidated on the basis of spectroscopic analysis, including 1D and 2D NMR techniques. The absolute configurations were established by comparison with the literature and Mo2(OAc)4-induced electronic circular dichroism (ECD) data. All the isolates were evaluated for cytotoxicity against A549 (lung carcinoma), MCF-7 (breast adenocarcinoma), and HepG2 (hepatocellular carcinoma) human cancer cell lines. Three of the new cholestane-type steroids displayed potent antiproliferative effects on the tumor cells with IC50 values ranging from 1.5 to 9.6μM, whereas the two new ergostane-type (5, 6) steroids were deemed inactive. Copyright © 2014 Elsevier Inc. All rights reserved.

Data Visualization for ESM and ELINT: Visualizing 3D and Hyper Dimensional Data

DTIC Science & Technology

2011-06-01

technique to present multiple 2D views was devised by D. Asimov . He assembled multiple two dimensional scatter plot views of the hyper dimensional...Viewing Multidimensional Data”, D. Asimov , DIAM Journal on Scientific and Statistical Computing, vol.61, pp.128-143, 1985. [2] “High-Dimensional

[Three-dimensional endoscopic endonasal study of skull base anatomy].

PubMed

Abarca-Olivas, Javier; Monjas-Cánovas, Irene; López-Álvarez, Beatriz; Lloret-García, Jaime; Sanchez-del Campo, Jose; Gras-Albert, Juan Ramon; Moreno-López, Pedro

2014-01-01

Training in dissection of the paranasal sinuses and the skull base is essential for anatomical understanding and correct surgical techniques. Three-dimensional (3D) visualisation of endoscopic skull base anatomy increases spatial orientation and allows depth perception. To show endoscopic skull base anatomy based on the 3D technique. We performed endoscopic dissection in cadaveric specimens fixed with formalin and with the Thiel technique, both prepared using intravascular injection of coloured material. Endonasal approaches were performed with conventional 2D endoscopes. Then we applied the 3D anaglyph technique to illustrate the pictures in 3D. The most important anatomical structures and landmarks of the sellar region under endonasal endoscopic vision are illustrated in 3D images. The skull base consists of complex bony and neurovascular structures. Experience with cadaver dissection is essential to understand complex anatomy and develop surgical skills. A 3D view constitutes a useful tool for understanding skull base anatomy. Copyright © 2012 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

An Approximate Axisymmetric Viscous Shock Layer Aeroheating Method for Three-Dimensional Bodies

NASA Technical Reports Server (NTRS)

Brykina, Irina G.; Scott, Carl D.

1998-01-01

A technique is implemented for computing hypersonic aeroheating, shear stress, and other flow properties on the windward side of a three-dimensional (3D) blunt body. The technique uses a 2D/axisymmetric flow solver modified by scale factors for a, corresponding equivalent axisymmetric body. Examples are given in which a 2D solver is used to calculate the flow at selected meridional planes on elliptic paraboloids in reentry flight. The report describes the equations and the codes used to convert the body surface parameters into input used to scale the 2D viscous shock layer equations in the axisymmetric viscous shock layer code. Very good agreement is obtained with solutions to finite rate chemistry 3D thin viscous shock layer equations for a finite rate catalytic body.

Bayer image parallel decoding based on GPU

NASA Astrophysics Data System (ADS)

Hu, Rihui; Xu, Zhiyong; Wei, Yuxing; Sun, Shaohua

2012-11-01

In the photoelectrical tracking system, Bayer image is decompressed in traditional method, which is CPU-based. However, it is too slow when the images become large, for example, 2K×2K×16bit. In order to accelerate the Bayer image decoding, this paper introduces a parallel speedup method for NVIDA's Graphics Processor Unit (GPU) which supports CUDA architecture. The decoding procedure can be divided into three parts: the first is serial part, the second is task-parallelism part, and the last is data-parallelism part including inverse quantization, inverse discrete wavelet transform (IDWT) as well as image post-processing part. For reducing the execution time, the task-parallelism part is optimized by OpenMP techniques. The data-parallelism part could advance its efficiency through executing on the GPU as CUDA parallel program. The optimization techniques include instruction optimization, shared memory access optimization, the access memory coalesced optimization and texture memory optimization. In particular, it can significantly speed up the IDWT by rewriting the 2D (Tow-dimensional) serial IDWT into 1D parallel IDWT. Through experimenting with 1K×1K×16bit Bayer image, data-parallelism part is 10 more times faster than CPU-based implementation. Finally, a CPU+GPU heterogeneous decompression system was designed. The experimental result shows that it could achieve 3 to 5 times speed increase compared to the CPU serial method.

Clinical analysis of speculum-based vaginal packing for high-dose-rate intracavitary tandem and ovoid brachytherapy in cervical cancer

PubMed Central

Sud, Shivani; Roth, Toni

2018-01-01

Purpose Intra-vaginal packing is used to fix the applicator and displace organs at risk (OAR) during high-dose-rate intracavitary tandem and ovoid brachytherapy (HDR-ICB). We retain the speculum from applicator placement as a dual-function bladder and rectum retractor during treatment. Our objective is to review salient techniques for OAR displacement, share our packing technique, and determine the reduction in dose to OAR and inter-fraction variability of dose to OAR, associated with speculum-based vaginal packing (SBVP) in comparison to conventional gauze packing during HDR-ICB. Material and methods We reviewed HDR-ICB treatment plans for 45 patients, including 10 who underwent both conventional gauze packing and SBVP. Due to institutional inter-provider practice differences, patients non-selectively received either packing procedure. Packing was performed under conscious sedation, followed by cone beam computed tomography used for dosimetric planning. Maximum absolute and percent-of-prescription dose to the International Commission of Radiation Units bladder and rectal points in addition to D0.1cc, D1.0cc, and D2.0cc volumes of the bladder and rectum were analyzed and compared for each packing method using an independent sample t-test. Results Of the 179 fractions included, 73% and 27% used SBVP and gauze packing, respectively. For patients prescribed 6 Gy to point A, SBVP was associated with reduced mean D0.1cc bladder dose, inter-fraction variability in D0.1cc bladder dose by 9.3% (p = 0.026) and 9.0%, respectively, and statistically equivalent rectal D0.1cc, D1.0cc, and D2.0cc. Patients prescribed 5.5 Gy or 5 Gy to point A after dose optimization, were less likely to benefit from SBVP. In the intra-patient comparison, 80% of patients had reduction in at least one rectum or bladder parameter. Conclusions In patients with conducive anatomy, SBVP is a cost-efficient packing method that is associated with improved bladder sparing and comparable rectal sparing relative to gauze packing during HDR-ICB without general anesthesia. PMID:29619054

Comparison of learning curves and skill transfer between classical and robotic laparoscopy according to the viewing conditions: implications for training.

PubMed

Blavier, Adélaïde; Gaudissart, Quentin; Cadière, Guy-Bernard; Nyssen, Anne-Sophie

2007-07-01

The purpose of this study was to evaluate the perceptual (2-dimensional [2D] vs. 3-dimensional [3D] view) and instrumental (classical vs. robotic) impacts of new robotic system on learning curves. Forty medical students without any surgical experience were randomized into 4 groups (classical laparoscopy with 3D-direct view or with 2D-indirect view, robotic system in 3D or in 2D) and repeated a laparoscopic task 6 times. After these 6 repetitions, they performed 2 trials with the same technique but in the other viewing condition (perceptive switch). Finally, subjects performed the last 3 trials with the technique they never used (technical switch). Subjects evaluated their performance answering a questionnaire (impressions of mastery, familiarity, satisfaction, self-confidence, and difficulty). Our study showed better performance and improvement in 3D view than in 2D view whatever the instrumental aspect. Participants reported less mastery, familiarity, and self-confidence and more difficulty in classical laparoscopy with 2D-indirect view than in the other conditions. Robotic surgery improves surgical performance and learning, particularly by 3D view advantage. However, perceptive and technical switches emphasize the need to adapt and pursue training also with traditional technology to prevent risks in conversion procedure.

Issues in the digital implementation of control compensators. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Moroney, P.

1979-01-01

Techniques developed for the finite-precision implementation of digital filters were used, adapted, and extended for digital feedback compensators, with particular emphasis on steady state, linear-quadratic-Gaussian compensators. Topics covered include: (1) the linear-quadratic-Gaussian problem; (2) compensator structures; (3) architectural issues: serialism, parallelism, and pipelining; (4) finite wordlength effects: quantization noise, quantizing the coefficients, and limit cycles; and (5) the optimization of structures.

Two- and three-dimensional accuracy of dental impression materials: effects of storage time and moisture contamination.

PubMed

Chandran, Deepa T; Jagger, Daryll C; Jagger, Robert G; Barbour, Michele E

2010-01-01

Dental impression materials are used to create an inverse replica of the dental hard and soft tissues, and are used in processes such as the fabrication of crowns and bridges. The accuracy and dimensional stability of impression materials are of paramount importance to the accuracy of fit of the resultant prosthesis. Conventional methods for assessing the dimensional stability of impression materials are two-dimensional (2D), and assess shrinkage or expansion between selected fixed points on the impression. In this study, dimensional changes in four impression materials were assessed using an established 2D and an experimental three-dimensional (3D) technique. The former involved measurement of the distance between reference points on the impression; the latter a contact scanning method for producing a computer map of the impression surface showing localised expansion, contraction and warpage. Dimensional changes were assessed as a function of storage times and moisture contamination comparable to that found in clinical situations. It was evident that dimensional changes observed using the 3D technique were not always apparent using the 2D technique, and that the former offers certain advantages in terms of assessing dimensional accuracy and predictability of impression methods. There are, however, drawbacks associated with 3D techniques such as the more time-consuming nature of the data acquisition and difficulty in statistically analysing the data.

Stability analysis of nonlinear Roesser-type two-dimensional systems via a homogenous polynomial technique

NASA Astrophysics Data System (ADS)

Zhang, Tie-Yan; Zhao, Yan; Xie, Xiang-Peng

2012-12-01

This paper is concerned with the problem of stability analysis of nonlinear Roesser-type two-dimensional (2D) systems. Firstly, the fuzzy modeling method for the usual one-dimensional (1D) systems is extended to the 2D case so that the underlying nonlinear 2D system can be represented by the 2D Takagi—Sugeno (TS) fuzzy model, which is convenient for implementing the stability analysis. Secondly, a new kind of fuzzy Lyapunov function, which is a homogeneous polynomially parameter dependent on fuzzy membership functions, is developed to conceive less conservative stability conditions for the TS Roesser-type 2D system. In the process of stability analysis, the obtained stability conditions approach exactness in the sense of convergence by applying some novel relaxed techniques. Moreover, the obtained result is formulated in the form of linear matrix inequalities, which can be easily solved via standard numerical software. Finally, a numerical example is also given to demonstrate the effectiveness of the proposed approach.

Coupled two-dimensional edge plasma and neutral gas modeling of tokamak scrape-off-layers

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

Maingi, Rajesh

1992-08-01

The objective of this study is to devise a detailed description of the tokamak scrape-off-layer (SOL), which includes the best available models of both the plasma and neutral species and the strong coupling between the two in many SOL regimes. A good estimate of both particle flux and heat flux profiles at the limiter/divertor target plates is desired. Peak heat flux is one of the limiting factors in determining the survival probability of plasma-facing-components at high power levels. Plate particle flux affects the neutral flux to the pump, which determines the particle exhaust rate. A technique which couples a two-dimensionalmore » (2-D) plasma and a 2-D neutral transport code has been developed (coupled code technique), but this procedure requires large amounts of computer time. Relevant physics has been added to an existing two-neutral-species model which takes the SOL plasma/neutral coupling into account in a simple manner (molecular physics model), and this model is compared with the coupled code technique mentioned above. The molecular physics model is benchmarked against experimental data from a divertor tokamak (DIII-D), and a similar model (single-species model) is benchmarked against data from a pump-limiter tokamak (Tore Supra). The models are then used to examine two key issues: free-streaming-limits (ion energy conduction and momentum flux) and the effects of the non-orthogonal geometry of magnetic flux surfaces and target plates on edge plasma parameter profiles.« less

Three-dimensional near-field MIMO array imaging using range migration techniques.

PubMed

Zhuge, Xiaodong; Yarovoy, Alexander G

2012-06-01

This paper presents a 3-D near-field imaging algorithm that is formulated for 2-D wideband multiple-input-multiple-output (MIMO) imaging array topology. The proposed MIMO range migration technique performs the image reconstruction procedure in the frequency-wavenumber domain. The algorithm is able to completely compensate the curvature of the wavefront in the near-field through a specifically defined interpolation process and provides extremely high computational efficiency by the application of the fast Fourier transform. The implementation aspects of the algorithm and the sampling criteria of a MIMO aperture are discussed. The image reconstruction performance and computational efficiency of the algorithm are demonstrated both with numerical simulations and measurements using 2-D MIMO arrays. Real-time 3-D near-field imaging can be achieved with a real-aperture array by applying the proposed MIMO range migration techniques.

MR angiography of the renal artery: comparison of breath-hold two-dimensional phase-contrast cine technique with the phased-array coil and breath-hold two-dimensional time-of-flight technique with the body coil.

PubMed

Masui, T; Takehara, Y; Igarashi, T; Ichijo, K; Takahashi, M; Kaneko, M; Nozaki, A

1997-07-01

Breath-hold 2D phase-contrast (PC) cine MR angiography with a phased-array coil and 2D time-of-flight (TOF) MR angiography were performed in the renal arteries and their findings were compared. Breath-hold 2D thin slice PC and TOF MR angiography were performed in 10 normal volunteers for renal arteries. A PC technique with k-space segmentation was utilized with the phased-array coil. A PC technique provided visualization of the renal artery more distally than a TOF technique (4.8 +/- 0.5 cm vs. 3.7 +/- 0.8 cm). With cardiac triggering, distal renal arteries were well demonstrated in PC MR angiography. On PC images, up- or downward movements of the mid to distal renal arteries with aortic pulsatility were recognized. The quality of the images was better with the PC than with the TOF technique (3.4 vs. 2.7). The mid to distal portions of the renal arteries translationally move with aortic pulsatility. To consistently visualize and evaluate them on MR angiography, cardiac triggering might be required to reduce the effects of pulsatile motions of the renal artery in the use of a phased-array coil.

Corrosion and Corrosion-Fatigue Behavior of 7075 Aluminum Alloys Studied by In Situ X-Ray Tomography

NASA Astrophysics Data System (ADS)

Stannard, Tyler

7XXX Aluminum alloys have high strength to weight ratio and low cost. They are used in many critical structural applications including automotive and aerospace components. These applications frequently subject the alloys to static and cyclic loading in service. Additionally, the alloys are often subjected to aggressive corrosive environments such as saltwater spray. These chemical and mechanical exposures have been known to cause premature failure in critical applications. Hence, the microstructural behavior of the alloys under combined chemical attack and mechanical loading must be characterized further. Most studies to date have analyzed the microstructure of the 7XXX alloys using two dimensional (2D) techniques. While 2D studies yield valuable insights about the properties of the alloys, they do not provide sufficiently accurate results because the microstructure is three dimensional and hence its response to external stimuli is also three dimensional (3D). Relevant features of the alloys include the grains, subgrains, intermetallic inclusion particles, and intermetallic precipitate particles. The effects of microstructural features on corrosion pitting and corrosion fatigue of aluminum alloys has primarily been studied using 2D techniques such as scanning electron microscopy (SEM) surface analysis along with post-mortem SEM fracture surface analysis to estimate the corrosion pit size and fatigue crack initiation site. These studies often limited the corrosion-fatigue testing to samples in air or specialized solutions, because samples tested in NaCl solution typically have fracture surfaces covered in corrosion product. Recent technological advancements allow observation of the microstructure, corrosion and crack behavior of aluminum alloys in solution in three dimensions over time (4D). In situ synchrotron X-Ray microtomography was used to analyze the corrosion and cracking behavior of the alloy in four dimensions to elucidate crack initiation at corrosion pits for samples of multiple aging conditions and impurity concentrations. Additionally, chemical reactions between the 3.5 wt% NaCl solution and the crack surfaces were quantified by observing the evolution of hydrogen bubbles from the crack. The effects of the impurity particles and age-hardening particles on the corrosion and fatigue properties were examined in 4D.