Theoretical analysis and experimental evaluation of a CsI(Tl) based electronic portal imaging system

International Nuclear Information System (INIS)

Sawant, Amit; Zeman, Herbert; Samant, Sanjiv; Lovhoiden, Gunnar; Weinberg, Brent; DiBianca, Frank

2002-01-01

This article discusses the design and analysis of a portal imaging system based on a thick transparent scintillator. A theoretical analysis using Monte Carlo simulation was performed to calculate the x-ray quantum detection efficiency (QDE), signal to noise ratio (SNR) and the zero frequency detective quantum efficiency [DQE(0)] of the system. A prototype electronic portal imaging device (EPID) was built, using a 12.7 mm thick, 20.32 cm diameter, CsI(Tl) scintillator, coupled to a liquid nitrogen cooled CCD TV camera. The system geometry of the prototype EPID was optimized to achieve high spatial resolution. The experimental evaluation of the prototype EPID involved the determination of contrast resolution, depth of focus, light scatter and mirror glare. Images of humanoid and contrast detail phantoms were acquired using the prototype EPID and were compared with those obtained using conventional and high contrast portal film and a commercial EPID. A theoretical analysis was also carried out for a proposed full field of view system using a large area, thinned CCD camera and a 12.7 mm thick CsI(Tl) crystal. Results indicate that this proposed design could achieve DQE(0) levels up to 11%, due to its order of magnitude higher QDE compared to phosphor screen-metal plate based EPID designs, as well as significantly higher light collection compared to conventional TV camera based systems

Monolayer graphene-insulator-semiconductor emitter for large-area electron lithography

Science.gov (United States)

Kirley, Matthew P.; Aloui, Tanouir; Glass, Jeffrey T.

2017-06-01

The rapid adoption of nanotechnology in fields as varied as semiconductors, energy, and medicine requires the continual improvement of nanopatterning tools. Lithography is central to this evolving nanotechnology landscape, but current production systems are subject to high costs, low throughput, or low resolution. Herein, we present a solution to these problems with the use of monolayer graphene in a graphene-insulator-semiconductor (GIS) electron emitter device for large-area electron lithography. Our GIS device displayed high emission efficiency (up to 13%) and transferred large patterns (500 × 500 μm) with high fidelity (industries and opening opportunities in nanomanufacturing.

Prospective clinical evaluation of an electronic portal imaging device

International Nuclear Information System (INIS)

Michalski, Jeff M.; Graham, Mary V.; Bosch, Walter R.; Wong, John; Gerber, Russell L.; Cheng, Abel; Tinger, Alfred; Valicenti, Richard K.

1996-01-01

Purpose: To determine whether the clinical implementation of an electronic portal imaging device can improve the precision of daily external beam radiotherapy. Methods and Materials: In 1991, an electronic portal imaging device was installed on a dual energy linear accelerator in our clinic. After training the radiotherapy technologists in the acquisition and evaluation of portal images, we performed a randomized study to determine whether online observation, interruption, and intervention would result in more precise daily setup. The patients were randomized to one of two groups: those whose treatments were actively monitored by the radiotherapy technologists and those that were imaged but not monitored. The treating technologists were instructed to correct the following treatment errors: (a) field placement error (FPE) > 1 cm; (b) incorrect block; (c) incorrect collimator setting; (d) absent customized block. Time of treatment delivery was recorded by our patient tracking and billing computers and compared to a matched set of patients not participating in the study. After the patients radiation therapy course was completed, an offline analysis of the patient setup error was planned. Results: Thirty-two patients were treated to 34 anatomical sites in this study. In 893 treatment sessions, 1,873 fields were treated (1,089 fields monitored and 794 fields unmonitored). Ninety percent of the treated fields had at least one image stored for offline analysis. Eighty-seven percent of these images were analyzed offline. Of the 1,011 fields imaged in the monitored arm, only 14 (1.4%) had an intervention recorded by the technologist. Despite infrequent online intervention, offline analysis demonstrated that the incidence of FPE > 10 mm in the monitored and unmonitored groups was 56 out of 881 (6.1%) and 95 out of 595 (11.2%), respectively; p 10 mm was confined to the pelvic fields. The time to treat patients in this study was 10.78 min (monitored) and 10.10 min (unmonitored

Quality assurance for electronic portal imaging devices

International Nuclear Information System (INIS)

Shalev, S.; Rajapakshe, R.; Gluhchev, G.; Luchka, K.

1997-01-01

Electronic portal imaging devices (EPIDS) are assuming an ever-increasing role in the verification of radiation treatment accuracy. They are used both in a passive capacity, for the determination of field displacement distributions (''setup errors''), and also in an active role whereby the patient setup is corrected on the basis of electronic portal images. In spite of their potential impact on the precision of patient treatment, there are few quality assurance procedures available, and most of the EPIDS in clinical use are subject, at best, to only perfunctory quality assurance. The goals of this work are (a) to develop an objective and reproducible test for EPID image quality on the factory floor and during installation of the EPID on site; (b) to provide the user with a simple and accurate tool for acceptance, commissioning, and routine quality control; and (c) to initiate regional, national and international collaboration in the implementation of standardized, objective, and automated quality assurance procedures. To this end we have developed an automated test in which a simple test object is imaged daily, and the spatial and contrast resolution of the EPID are automatically evaluated in terms of ''acceptable'', ''warning'' and ''stop'' criteria. Our experience over two years shows the test to be highly sensitive, reproducible, and inexpensive in time and effort. Inter-institutional trials are under way in Canada, US and Europe which indicate large variations in EPID image quality from one EPID to another, and from one center to another. We expect the new standardized quality assurance procedure to lead to improved, and consistent image quality, increased operator acceptance of the technology, and agreement on uniform standards by equipment suppliers and health care agencies. (author)

Front-end electronics for the Muon Portal project

Energy Technology Data Exchange (ETDEWEB)

Garozzo, S.; Marano, D.; Bonanno, G.; Grillo, A.; Romeo, G.; Timpanaro, M.C. [INAF, Osservatorio Astrofisico di Catania, Via S. Sofia 78, I-95123 Catania (Italy); Lo Presti, D.; Riggi, F.; Russo, V.; Bonanno, D.; La Rocca, P.; Longhitano, F.; Bongiovanni, D.G. [Università di Catania, Dipartimento di Fisica e Astronomia, and INFN, Sezione di Catania, Via S. Sofia 64, I-95123 Catania (Italy); Fallica, G.; Valvo, G. [ST-Microelectronics, Stradale V Primosole 50, Catania (Italy)

2016-10-11

The Muon Portal Project was born as a joint initiative between Italian research and industrial partners, aimed at the construction of a real-size working detector prototype to inspect the content of traveling containers by means of secondary cosmic-ray muon radiation and recognize potentially dangerous hidden materials. The tomographic image is obtained by reconstructing the incoming and outgoing muon trajectories when crossing the inspected volume, employing two tracker planes located above and below the container under inspection. In this paper, the design and development of the front-end electronics of the Muon Portal detector is presented, with particular emphasis being devoted to the photo-sensor devices detecting the scintillation light and to the read-out circuitry which is in charge of processing and digitizing the analog pulse signals. In addition, the remote control system, mechanical housing, and thermal cooling system of all structural blocks of the Muon Portal tracker are also discussed, demonstrating the effectiveness and functionality of the adopted design.

Use of an electronic patient portal among the chronically ill: an observational study.

Science.gov (United States)

Riippa, Iiris; Linna, Miika; Rönkkö, Ilona; Kröger, Virpi

2014-12-08

Electronic patient portals may enhance effective interaction between the patient and the health care provider. To grasp the full potential of patient portals, health care providers need more knowledge on which patient groups prefer electronic services and how patients should be served through this channel. The objective of this study was to assess how chronically ill patients' state of health, comorbidities, and previous care are associated with their adoption and use of a patient portal. A total of 222 chronically ill patients, who were offered access to a patient portal with their health records and secure messaging with care professionals, were included in the study. Differences in the characteristics of non-users, viewers, and interactive users of the patient portal were analyzed before access to the portal. Patients' age, gender, diagnoses, levels of the relevant physiological measurements, health care contacts, and received physiological measurements were collected from the care provider's electronic health record. In addition, patient-reported health and patient activation were assessed by a survey. Despite the broad range of measures used to indicate the patients' state of health, the portal user groups differed only in their recorded diagnosis for hypertension, which was most common in the non-user group. However, there were significant differences in the amount of care received during the year before access to the portal. The non-user group had more nurse visits and more measurements of relevant physiological outcomes than viewers and interactive users. They also had fewer referrals to specialized care during the year before access to the portal than the two other groups. The viewers and the interactive users differed from each other significantly in the number of nurse calls received, the interactive users having more calls than the viewers. No significant differences in age, gender, or patient activation were detected between the user groups. Previous

Portal hemodynamics in chronic portal-systemic encephalopathy

International Nuclear Information System (INIS)

Takashi, Motohide; Igarashi, Masahiko; Hino, Shinichi; Takayasu, Kenichi; Goto, Nobuaki; Musha, Hirotaka; Ohnishi, Kunihiko; Okuda, Kunio

1985-01-01

A portal hemodynamic study was made in 7 consecutive patients with chronic portal-systemic encephalopathy by percutaneous transhepatic catheterization of the portal vein and injecting contrast medium into the superior mesenteric vein or by superior mesenteric arterial portography in comparison with patients without encephalopathy studied by percutaneous catheterization of these veins. It is suggested that chronic portal-systemic encephalopathy is a result of a large collateral route shunting a large proportion of the superior mesenteric venous blood into systemic circulation, and that development of such collaterals precludes formation of large esophageal varices. (Auth.)

Gravure printing of graphene for large-area flexible electronics.

Science.gov (United States)

Secor, Ethan B; Lim, Sooman; Zhang, Heng; Frisbie, C Daniel; Francis, Lorraine F; Hersam, Mark C

2014-07-09

Gravure printing of graphene is demonstrated for the rapid production of conductive patterns on flexible substrates. Development of suitable inks and printing parameters enables the fabrication of patterns with a resolution down to 30 μm. A mild annealing step yields conductive lines with high reliability and uniformity, providing an efficient method for the integration of graphene into large-area printed and flexible electronics. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Analysis of patient setup accuracy using electronic portal imaging device

International Nuclear Information System (INIS)

Onogi, Yuzo; Aoki, Yukimasa; Nakagawa, Keiichi

1996-01-01

Radiation therapy is performed in many fractions, and accurate patient setup is very important. This is more significant nowadays because treatment planning and radiation therapy are more precisely performed. Electronic portal imaging devices and automatic image comparison algorithms let us analyze setup deviations quantitatively. With such in mind we developed a simple image comparison algorithm. Using 2459 electronic verification images (335 ports, 123 treatment sites) generated during the past three years at our institute, we evaluated the results of the algorithm, and analyzed setup deviations according to the area irradiated, use of a fixing device (shell), and arm position. Calculated setup deviation was verified visually and their fitness was classified into good, fair, bad, and incomplete. The result was 40%, 14%, 22%, 24% respectively. Using calculated deviations classified as good (994 images), we analyzed setup deviations. Overall setup deviations described in 1 SD along axes x, y, z, was 1.9 mm, 2.5 mm, 1.7 mm respectively. We classified these deviations into systematic and random components, and found that random error was predominant in our institute. The setup deviations along axis y (cranio-caudal direction) showed larger distribution when treatment was performed with the shell. Deviations along y (cranio-caudal) and z (anterior-posterior) had larger distribution when treatment occurred with the patient's arm elevated. There was a significant time-trend error, whose deviations become greater with time. Within all evaluated ports, 30% showed a time-trend error. Using an electronic portal imaging device and automatic image comparison algorithm, we are able to analyze setup deviations more precisely and improve setup method based on objective criteria. (author)

[100] or [110] aligned, semiconductor-based, large-area, flexible, electronic devices

Science.gov (United States)

Goyal, Amit

2015-03-24

Novel articles and methods to fabricate the same resulting in flexible, large-area, [100] or [110] textured, semiconductor-based, electronic devices are disclosed. Potential applications of resulting articles are in areas of photovoltaic devices, flat-panel displays, thermophotovoltaic devices, ferroelectric devices, light emitting diode devices, computer hard disc drive devices, magnetoresistance based devices, photoluminescence based devices, non-volatile memory devices, dielectric devices, thermoelectric devices and quantum dot laser devices.

Patient Use of the Electronic Communication Portal in Management of Type 2 Diabetes.

Science.gov (United States)

Peremislov, Diana

2017-09-01

High incidence and prevalence of type 2 diabetes require urgent attention to the management of this chronic disease. The purpose of this study was to explore electronic communication (e-communication) between patients with type 2 diabetes and their providers within the patient portal. Qualitative design with conventional content analysis techniques was used. A purposive random sample of 90 electronic medical record charts of patient-portal users with type 2 diabetes was subjected to a retrospective review. The sample mainly consisted of patients between the ages of 50 and 70 years, who were white, non-Hispanic, and English-speaking. The three major themes that emerged in e-communication via patient portal were inform theme, which was the most frequently identified theme; instruct/request theme, which was mainly used in initiation of e-communication; and the question theme. The patient portal was used primarily for requests by patients and instruction by providers, showing relatively short e-message encounters with a high number of partially completed encounters, frequent lack of resolution, and a low level of involvement of diabetes specialists in e-communication. There is a need to revise healthcare system guidelines on initiation and use of e-communication via patient portal and develop standardized templates to promote diabetes education in type 2 diabetes.

A literature review of electronic portal imaging for radiotherapy dosimetry

NARCIS (Netherlands)

van Elmpt, Wouter; McDermott, Leah; Nijsten, Sebastiaan; Wendling, Markus; Lambin, Philippe; Mijnheer, Ben

2008-01-01

Electronic portal imaging devices (EPIDs) have been the preferred tools for verification of patient positioning for radiotherapy in recent decades. Since EPID images contain dose information, many groups have investigated their use for radiotherapy dose measurement. With the introduction of the

Positive identity entry control system with geographically distributed portals and enrollment stations

International Nuclear Information System (INIS)

McIntire, J.M.

1985-01-01

A positive identity entry control system using distributed processing to allow reliable geographically separated portals and enrollment stations has been installed and is fully operational at a large area DOE site. Identity verification requires a credential, a memorized number and measurement of a physical characteristic of the user. Additionally, all portal activity is monitored by guards. The portal system is dual redundant such that no single point failure will shut down operations. Each portal site maintains its own subset of the master data base so off-site failure of the central data base manager or its communication links will not significantly affect local portal activity. The system is suitable for installations with large populations requiring access control at several remote sites scattered over a large area

ESTERR-PRO: A Setup Verification Software System Using Electronic Portal Imaging

Directory of Open Access Journals (Sweden)

Pantelis A. Asvestas

2007-01-01

Full Text Available The purpose of the paper is to present and evaluate the performance of a new software-based registration system for patient setup verification, during radiotherapy, using electronic portal images. The estimation of setup errors, using the proposed system, can be accomplished by means of two alternate registration methods. (a The portal image of the current fraction of the treatment is registered directly with the reference image (digitally reconstructed radiograph (DRR or simulator image using a modified manual technique. (b The portal image of the current fraction of the treatment is registered with the portal image of the first fraction of the treatment (reference portal image by applying a nearly automated technique based on self-organizing maps, whereas the reference portal has already been registered with a DRR or a simulator image. The proposed system was tested on phantom data and on data from six patients. The root mean square error (RMSE of the setup estimates was 0.8±0.3 (mean value ± standard deviation for the phantom data and 0.3±0.3 for the patient data, respectively, by applying the two methodologies. Furthermore, statistical analysis by means of the Wilcoxon nonparametric signed test showed that the results that were obtained by the two methods did not differ significantly (P value >0.05.

Electron Emission from Ultra-Large Area MOS Electron Emitters

DEFF Research Database (Denmark)

Thomsen, Lasse Bjørchmar; Nielsen, Gunver; Vendelbo, Søren Bastholm

2009-01-01

Ultralarge metal-oxide-semiconductor (MOS) devices with an active oxide area of 1 cm2 have been fabricated for use as electron emitters. The MOS structures consist of a Si substrate, a SiO2 tunnel barrier (~5 nm), a Ti wetting layer (3–10 Å), and a Au top layer (5–60 nm). Electron emission from...... layer is varied from 3 to 10 Å which changes the emission efficiency by more than one order of magnitude. The apparent mean free path of ~5 eV electrons in Au is found to be 52 Å. Deposition of Cs on the Au film increased the electron emission efficiency to 4.3% at 4 V by lowering the work function....... Electron emission under high pressures (up to 2 bars) of Ar was observed. ©2009 American Vacuum Society...

Information Portal Costs and Benefits

Directory of Open Access Journals (Sweden)

Lorena BATAGAN

2006-01-01

Full Text Available All transformations of our society are the product of the large use of Information and Communications Technologies (ICT and Internet. ICT are technologies which facilitate communication, processing, and transmission of information by electronic means. It is very important to use the new technologies to the correct value because this determinate an increase of global benefits. Portal provides a consistent way to select, evaluate, prioritize and plan the right information. In research we point the important costs and benefits for an informational portal. The portal for local administrative determinate for citizens the access to information of interest and on the other hand make easier for employer to manage the documents.

Large area strain analysis using scanning transmission electron microscopy across multiple images

International Nuclear Information System (INIS)

Oni, A. A.; Sang, X.; LeBeau, J. M.; Raju, S. V.; Saxena, S.; Dumpala, S.; Broderick, S.; Rajan, K.; Kumar, A.; Sinnott, S.

2015-01-01

Here, we apply revolving scanning transmission electron microscopy to measure lattice strain across a sample using a single reference area. To do so, we remove image distortion introduced by sample drift, which usually restricts strain analysis to a single image. Overcoming this challenge, we show that it is possible to use strain reference areas elsewhere in the sample, thereby enabling reliable strain mapping across large areas. As a prototypical example, we determine the strain present within the microstructure of a Ni-based superalloy directly from atom column positions as well as geometric phase analysis. While maintaining atomic resolution, we quantify strain within nanoscale regions and demonstrate that large, unit-cell level strain fluctuations are present within the intermetallic phase

Development of Geometrical Quality Control Real-time Analysis Program using an Electronic Portal Imaging

International Nuclear Information System (INIS)

Lee, Sang Rok; Jung, Kyung Yong; Jang, Min Sun; Lee, Byung Gu; Kwon, Young Ho

2012-01-01

To develop a geometrical quality control real-time analysis program using an electronic portal imaging to replace film evaluation method. A geometrical quality control item was established with the Eclipse treatment planning system (Version 8.1, Varian, USA) after the Electronic Portal Imaging Device (EPID) took care of the problems occurring from the fixed substructure of the linear accelerator (CL-iX, Varian, USA). Electronic portal image (single exposure before plan) was created at the treatment room's 4DTC (Version 10.2, Varian, USA) and a beam was irradiated in accordance with each item. The gaining the entire electronic portal imaging at the Off-line review and was evaluated by a self-developed geometrical quality control real-time analysis program. As for evaluation methods, the intra-fraction error was analyzed by executing 5 times in a row under identical conditions and procedures on the same day, and in order to confirm the infer-fraction error, it was executed for 10 days under identical conditions of all procedures and was compared with the film evaluation method using an Iso-align quality control device. Measurement and analysis time was measured by sorting the time into from the device setup to data achievement and the time amount after the time until the completion of analysis and the convenience of the users and execution processes were compared. The intra-fraction error values for each average 0.1, 0.2, 0.3, 0.2 mm at light-radiation field coincidence, collimator rotation axis, couch rotation axis and gantry rotation axis. By checking the infer-fraction error through 10 days of continuous quality control, the error values obtained were average 1.7, 1.4, 0.7, 1.1 mm for each item. Also, the measurement times were average 36 minutes, 15 minutes for the film evaluation method and electronic portal imaging system, and the analysis times were average 30 minutes, 22 minutes. When conducting a geometrical quality control using an electronic portal imaging

Clinician Perspectives on an Electronic Portal to Improve Communication with Patients and Families in the Intensive Care Unit.

Science.gov (United States)

Bell, Sigall K; Roche, Stephanie D; Johansson, Anna C; O'Reilly, Kristin P; Lee, Barbara S; Sands, Kenneth E; Talmor, Daniel S; Brown, Samuel M

2016-12-01

Communication in the intensive care unit (ICU) often falls short of patient and family needs, putting them at risk for significant physical and emotional harm. As electronic patient portals rapidly evolve, one designed specifically for the ICU might potentially enhance communication among patients, family members, and clinicians; however, the views of frontline ICU staff on such technology are unknown. To identify clinician perspectives on the current state of communication among patients, families, and clinicians in the ICU, and assess their views on whether and how an electronic portal may address existing communication deficits and improve care. Three focus groups comprised altogether of 26 clinicians from 6 ICUs, representing several disciplines in an academic medical center in Boston, Massachusetts. Transcripts were analyzed inductively for major themes using grounded theory. We identified seven themes reflecting clinician perspectives on communication challenges and desired portal functionality: (1) comprehension and literacy; (2) results and updates; (3) patient and family preferences; (4) interclinician communication; (5) family informational needs; (6) the ICU as an unfamiliar environment; and (7) enhancing humanism through technology. Each theme included current gaps in practice, potential benefits and concerns related to an ICU communication portal, and participant recommendations. Benefits included enhanced education, patient/family engagement, and clinician workflow. Challenges included the stress and uncertainty of ICU care, fear of technology replacing human connection, existing interclinician communication failures, and the tension between informing families without overwhelming them. Overall, clinicians were cautiously supportive of an electronic portal to enhance communication in the ICU and made several specific recommendations for design and implementation. As new technologies expand opportunities for greater transparency and participation in

Analysis of interfraction and intrafraction variation during tangential breast irradiation with an electronic portal imaging device

International Nuclear Information System (INIS)

Smith, Ryan P.; Bloch, Peter; Harris, Eleanor E.; McDonough, James; Sarkar, Abhirup; Kassaee, Alireza; Avery, Steven; Solin, Lawrence J.

2005-01-01

Purpose: To evaluate the daily setup variation and the anatomic movement of the heart and lungs during breast irradiation with tangential photon beams, as measured with an electronic portal imaging device. Methods and materials: Analysis of 1,709 portal images determined changes in the radiation field during a treatment course in 8 patients. Values obtained for every image included central lung distance (CLD) and area of lung and heart within the irradiated field. The data from these measurements were used to evaluate variation from setup between treatment days and motion due to respiration and/or patient movement during treatment delivery. Results: The effect of respiratory motion and movement during treatment was minimal: the maximum range in CLD for any patient on any day was 0.25 cm. The variation caused by day-to-day setup variation was greater, with CLD values for patients ranging from 0.59 cm to 2.94 cm. Similar findings were found for heart and lung areas. Conclusions: There is very little change in CLD and corresponding lung and heart area during individual radiation treatment fractions in breast tangential fields, compared with a relatively greater amount of variation that occurs between days

The BioMart community portal: an innovative alternative to large, centralized data repositories

Science.gov (United States)

Smedley, Damian; Haider, Syed; Durinck, Steffen; Pandini, Luca; Provero, Paolo; Allen, James; Arnaiz, Olivier; Awedh, Mohammad Hamza; Baldock, Richard; Barbiera, Giulia; Bardou, Philippe; Beck, Tim; Blake, Andrew; Bonierbale, Merideth; Brookes, Anthony J.; Bucci, Gabriele; Buetti, Iwan; Burge, Sarah; Cabau, Cédric; Carlson, Joseph W.; Chelala, Claude; Chrysostomou, Charalambos; Cittaro, Davide; Collin, Olivier; Cordova, Raul; Cutts, Rosalind J.; Dassi, Erik; Genova, Alex Di; Djari, Anis; Esposito, Anthony; Estrella, Heather; Eyras, Eduardo; Fernandez-Banet, Julio; Forbes, Simon; Free, Robert C.; Fujisawa, Takatomo; Gadaleta, Emanuela; Garcia-Manteiga, Jose M.; Goodstein, David; Gray, Kristian; Guerra-Assunção, José Afonso; Haggarty, Bernard; Han, Dong-Jin; Han, Byung Woo; Harris, Todd; Harshbarger, Jayson; Hastings, Robert K.; Hayes, Richard D.; Hoede, Claire; Hu, Shen; Hu, Zhi-Liang; Hutchins, Lucie; Kan, Zhengyan; Kawaji, Hideya; Keliet, Aminah; Kerhornou, Arnaud; Kim, Sunghoon; Kinsella, Rhoda; Klopp, Christophe; Kong, Lei; Lawson, Daniel; Lazarevic, Dejan; Lee, Ji-Hyun; Letellier, Thomas; Li, Chuan-Yun; Lio, Pietro; Liu, Chu-Jun; Luo, Jie; Maass, Alejandro; Mariette, Jerome; Maurel, Thomas; Merella, Stefania; Mohamed, Azza Mostafa; Moreews, Francois; Nabihoudine, Ibounyamine; Ndegwa, Nelson; Noirot, Céline; Perez-Llamas, Cristian; Primig, Michael; Quattrone, Alessandro; Quesneville, Hadi; Rambaldi, Davide; Reecy, James; Riba, Michela; Rosanoff, Steven; Saddiq, Amna Ali; Salas, Elisa; Sallou, Olivier; Shepherd, Rebecca; Simon, Reinhard; Sperling, Linda; Spooner, William; Staines, Daniel M.; Steinbach, Delphine; Stone, Kevin; Stupka, Elia; Teague, Jon W.; Dayem Ullah, Abu Z.; Wang, Jun; Ware, Doreen; Wong-Erasmus, Marie; Youens-Clark, Ken; Zadissa, Amonida; Zhang, Shi-Jian; Kasprzyk, Arek

2015-01-01

The BioMart Community Portal (www.biomart.org) is a community-driven effort to provide a unified interface to biomedical databases that are distributed worldwide. The portal provides access to numerous database projects supported by 30 scientific organizations. It includes over 800 different biological datasets spanning genomics, proteomics, model organisms, cancer data, ontology information and more. All resources available through the portal are independently administered and funded by their host organizations. The BioMart data federation technology provides a unified interface to all the available data. The latest version of the portal comes with many new databases that have been created by our ever-growing community. It also comes with better support and extensibility for data analysis and visualization tools. A new addition to our toolbox, the enrichment analysis tool is now accessible through graphical and web service interface. The BioMart community portal averages over one million requests per day. Building on this level of service and the wealth of information that has become available, the BioMart Community Portal has introduced a new, more scalable and cheaper alternative to the large data stores maintained by specialized organizations. PMID:25897122

A radiation-tolerant electronic readout system for portal imaging

Science.gov (United States)

Östling, J.; Brahme, A.; Danielsson, M.; Iacobaeus, C.; Peskov, V.

2004-06-01

A new electronic portal imaging device, EPID, is under development at the Karolinska Institutet and the Royal Institute of Technology. Due to considerable demands on radiation tolerance in the radiotherapy environment, a dedicated electronic readout system has been designed. The most interesting aspect of the readout system is that it allows to read out ˜1000 pixels in parallel, with all electronics placed outside the radiation beam—making the detector more radiation resistant. In this work we are presenting the function of a small prototype (6×100 pixels) of the electronic readout board that has been tested. Tests were made with continuous X-rays (10-60 keV) and with α particles. The results show that, without using an optimised gas mixture and with an early prototype only, the electronic readout system still works very well.

Clinical Trial Electronic Portals for Expedited Safety Reporting: Recommendations from the Clinical Trials Transformation Initiative Investigational New Drug Safety Advancement Project.

Science.gov (United States)

Perez, Raymond P; Finnigan, Shanda; Patel, Krupa; Whitney, Shanell; Forrest, Annemarie

2016-12-15

Use of electronic clinical trial portals has increased in recent years to assist with sponsor-investigator communication, safety reporting, and clinical trial management. Electronic portals can help reduce time and costs associated with processing paperwork and add security measures; however, there is a lack of information on clinical trial investigative staff's perceived challenges and benefits of using portals. The Clinical Trials Transformation Initiative (CTTI) sought to (1) identify challenges to investigator receipt and management of investigational new drug (IND) safety reports at oncologic investigative sites and coordinating centers and (2) facilitate adoption of best practices for communicating and managing IND safety reports using electronic portals. CTTI, a public-private partnership to improve the conduct of clinical trials, distributed surveys and conducted interviews in an opinion-gathering effort to record investigator and research staff views on electronic portals in the context of the new safety reporting requirements described in the US Food and Drug Administration's final rule (Code of Federal Regulations Title 21 Section 312). The project focused on receipt, management, and review of safety reports as opposed to the reporting of adverse events. The top challenge investigators and staff identified in using individual sponsor portals was remembering several complex individual passwords to access each site. Also, certain tasks are time-consuming (eg, downloading reports) due to slow sites or difficulties associated with particular operating systems or software. To improve user experiences, respondents suggested that portals function independently of browsers and operating systems, have intuitive interfaces with easy navigation, and incorporate additional features that would allow users to filter, search, and batch safety reports. Results indicate that an ideal system for sharing expedited IND safety information is through a central portal used by

A large area cooled-CCD detector for electron microscopy

International Nuclear Information System (INIS)

Faruqi, A.R.; Andrews, H.N.; Raeburn, C.

1994-01-01

Large area cooled-CCDs are an excellent medium for (indirectly) recording electron images and electron diffraction patterns in real time and for use in electron tomography; real-time imaging is extremely useful in making rapid adjustments in the electron microscope. CCDs provide high sensitivity (useful for minimising dosage to radiation-sensitive biological specimen), good resolution, stable performance, excellent dynamic range and linearity and a reasonably fast readout.We have built an electron imaging device based on the EEV 1152 by 814 pixel CCD which is controlled from a unix based SUN Sparcstation operating under X-Windows. The incident 100 kV electrons are converted to visible light in a 0.5 mm thick YAG single crystal which is imaged through a lens on to the CCD.The CCD electronics is designed to be as flexible as possible and allows a wide variation in the readout speed to cater for the relatively fast application where readout noise is less critical and low readout noise applications where the extra few seconds of readout time are not significant. The CCD electronics is built in VME format which is controlled through a S-bus to VME driver. With two parallel channels of readout the whole image can be read out in similar 1 s (using the faster readout speed) with 16 bit precision and the image is displayed under X-Windows in a few seconds. The present readout works at 500 kHz and has a noise of similar 30 e rms per pixel. With a Peltier cooling device we can operate the CCD at similar -40 circle C which reduces the dark current adequately to allow exposures of up to several minutes. Several examples of patterns collected with the system on a Philips CM12 microscope will be presented. ((orig.))

Electronic Health Record Portal Adoption: a cross country analysis.

Science.gov (United States)

Tavares, Jorge; Oliveira, Tiago

2017-07-05

This study's goal is to understand the factors that drive individuals to adopt Electronic Health Record (EHR) portals and to estimate if there are differences between countries with different healthcare models. We applied a new adoption model using as a starting point the extended Unified Theory of Acceptance and Use of Technology (UTAUT2) by incorporating the Concern for Information Privacy (CFIP) framework. To evaluate the research model we used the partial least squares (PLS) - structural equation modelling (SEM) approach. An online questionnaire was administrated in the United States (US) and Europe (Portugal). We collected 597 valid responses. The statistically significant factors of behavioural intention are performance expectancy ([Formula: see text] total  = 0.285; P expectancy ([Formula: see text] total  = 0.160; P value ([Formula: see text] total  = 0.152; P value are only predictors in the US group. The model explained 53% of the variance in behavioural intention and 36% of the variance in use behaviour. Our study identified critical factors for the adoption of EHR portals and significant differences between the countries. Confidentiality issues do not seem to influence acceptance. The EHR portals usage patterns are significantly higher in US compared to Portugal.

Preferences of Current and Potential Patients and Family Members Regarding Implementation of Electronic Communication Portals in Intensive Care Units.

Science.gov (United States)

Brown, Samuel M; Bell, Sigall K; Roche, Stephanie D; Dente, Erica; Mueller, Ariel; Kim, Tae-Eun; O'Reilly, Kristin; Lee, Barbara Sarnoff; Sands, Ken; Talmor, Daniel

2016-03-01

The quality of communication with patients and family members in intensive care units (ICUs) is a focus of current interest for clinical care improvement. Electronic communication portals are commonly used in other healthcare settings to improve communication. We do not know whether patients and family members desire such portals in ICUs, and if so, what functionality they should provide. To define interest in and desired elements of an electronic communication portal among current and potential ICU patients and their family members. We surveyed, via an Internet panel, 1,050 English-speaking adults residing in the United States with a personal or family history of an ICU admission within 10 years (cohort A) and 1,050 individuals without a history of such admission (cohort B). We also administered a survey instrument in person to 105 family members of patients currently admitted to ICUs at an academic medical center in Boston (cohort C). Respondents, especially current ICU family members, supported an electronic communication portal, including access via an electronic tablet. They wanted at least daily updates, one-paragraph summaries of family meetings including a list of key decisions made, and knowledge of the role and experience of treating clinicians. Overall, they preferred detailed rather than "big picture" information. Respondents were generally comfortable sharing information with their family members. Preferences regarding a communication portal varied significantly by age, sex, ethnicity, and prior experience with ICU hospitalization. Electronic communication portals appear welcome in contemporary ICUs. Frequent updates, knowledge about the professional qualifications of clinicians, detailed medical information, and documentation of family meetings are particularly desired.

Multi-controller based 29 channel whole body portal monitor

International Nuclear Information System (INIS)

Dheeraj Reddy, J.; Narender Reddy, J.

2004-01-01

Portal Monitors are an essential part of personnel monitoring programme in any Nuclear Power Plant or Radiochemical/Reprocessing Plant. Compared to conventional Portal Monitors, whole-body Portals are preferred, for effective monitoring of entire body of the person being monitored for radioactive contamination. This is achieved by effectively distributing a large number of detectors on front/back of the person being monitored. The entry and exit for such Portals is usually side ways. The electronic system, designed essentially consists of powerful compact electronic circuits, comprising of three micro-controllers, a host of (32) 12C serial counters, other serial ADCs, DACs etc., apart from pulse processing, HV and LV circuits. Built-in embedded code has powerful fault diagnostics routines to show up failures in detector / detector electronics, HV, LV and other circuits apart from indicating contamination status, through visual and aural indications such as MIMIC, visual LCD display and individual channel counts etc. The Portal structural design consists of four individual SS members integrated, lead shielding assemblies (inside), on hinged support frames facilitate ease of assembling and dismantling of the structure. The detector arrangement is so arranged to have optimal uniform spread out, so as to record contamination of the whole body of the person being monitored. (author)

Large-Area, Ensemble Molecular Electronics: Motivation and Challenges.

Science.gov (United States)

Vilan, Ayelet; Aswal, Dinesh; Cahen, David

2017-03-08

We review charge transport across molecular monolayers, which is central to molecular electronics (MolEl), using large-area junctions (NmJ). We strive to provide a wide conceptual overview of three main subtopics. First, a broad introduction places NmJ in perspective to related fields of research and to single-molecule junctions (1mJ) in addition to a brief historical account. As charge transport presents an ultrasensitive probe for the electronic perfection of interfaces, in the second part ways to form both the monolayer and the contacts are described to construct reliable, defect-free interfaces. The last part is dedicated to understanding and analyses of current-voltage (I-V) traces across molecular junctions. Notwithstanding the original motivation of MolEl, I-V traces are often not very sensitive to molecular details and then provide a poor probe for chemical information. Instead, we focus on how to analyze the net electrical performance of molecular junctions, from a functional device perspective. Finally, we point to creation of a built-in electric field as a key to achieve functionality, including nonlinear current-voltage characteristics that originate in the molecules or their contacts to the electrodes. This review is complemented by a another review that covers metal-molecule-semiconductor junctions and their unique hybrid effects.

Large vehicle portal monitor for perimeter safeguards applications

International Nuclear Information System (INIS)

Caldwell, J.T.; Atwater, H.F.; Bernard, W.; Bieri, J.M.; Shunk, E.R.

1979-01-01

We have developed a class of vehicle portal monitors based on shielded 4π geometry neutron counting. we have derived and experimentally verified an analytical expression relating the detection sensitivity of the neutron tunnel vehicle portal monitor to four design parameters of the system. For a given number of neutron detectors, this design achieves one or more orders of magnitude improvement in nuclear materials detection sensitivity over previous vehicle portal monitors

New ICPP portal monitor

International Nuclear Information System (INIS)

Georgeson, M.A.; Nichols, C.E.

1981-04-01

A large area gas filled proportional-detector portal monitor mounted in a swinging door frame has been designed and developed at the Idaho Chemical Processing Plant (ICPP). This monitor extends the sensitivity and speed of personnel contamination detection to levels equal to or exceeding that obtained using hand-held portable survey techniques. The new monitor has state-of-the-art electronics which result in rapid response, and use statistical principles in the alarm logic to reduce or eliminate spurious alarms. In addition, the evaluation of this instrument indicates that it will detect small enough quantities of U-235 in shielded containers to meet current special nuclear materials (SNM) detection standards. Simultaneous detection of very low level contamination and small quantities of SNM results in a monitor particularly useful for nuclear installations

Suppression of the Transit -Time Instability in Large-Area Electron Beam Diodes

Science.gov (United States)

Myers, Matthew C.; Friedman, Moshe; Swanekamp, Stephen B.; Chan, Lop-Yung; Ludeking, Larry; Sethian, John D.

2002-12-01

Experiment, theory, and simulation have shown that large-area electron-beam diodes are susceptible to the transit-time instability. The instability modulates the electron beam spatially and temporally, producing a wide spread in electron energy and momentum distributions. The result is gross inefficiency in beam generation and propagation. Simulations indicate that a periodic, slotted cathode structure that is loaded with resistive elements may be used to eliminate the instability. Such a cathode has been fielded on one of the two opposing 60 cm × 200 cm diodes on the NIKE KrF laser at the Naval Research Laboratory. These diodes typically deliver 600 kV, 500 kA, 250 ns electron beams to the laser cell in an external magnetic field of 0.2 T. We conclude that the slotted cathode suppressed the transit-time instability such that the RF power was reduced by a factor of 9 and that electron transmission efficiency into the laser gas was improved by more than 50%.

Suppression of the transit-time instability in large-area electron beam diodes

International Nuclear Information System (INIS)

Myers, Matthew C.; Friedman, Moshe; Sethian, John D.; Swanekamp, Stephen B.; Chan, L.-Y.; Ludeking, Larry

2002-01-01

Experiment, theory, and simulation have shown that large-area electron-beam diodes are susceptible to the transit-time instability. The instability modulates the electron beam spatially and temporally, producing a wide spread in electron energy and momentum distributions. The result is gross inefficiency in beam generation and propagation. Simulations indicate that a periodic, slotted cathode structure that is loaded with resistive elements may be used to eliminate the instability. Such a cathode has been fielded on one of the two opposing 60 cm x 200 cm diodes on the NIKE KrF laser at the Naval Research Laboratory. These diodes typically deliver 600 kV, 500 kA, 250 ns electron beams to the laser cell in an external magnetic field of 0.2 T. We conclude that the slotted cathode suppressed the transit-time instability such that the RF power was reduced by a factor of 9 and that electron transmission efficiency into the laser gas was improved by more than 50%

An image correlation procedure for digitally reconstructed radiographs and electronic portal images

International Nuclear Information System (INIS)

Dong, Lei; Boyer, Arthur L.

1995-01-01

Purpose: To study a procedure that uses megavoltage digitally reconstructed radiographs (DRRs) calculated from patient's three-dimensional (3D) computed tomography (CT) data as a reference image for correlation with on-line electronic portal images (EPIs) to detect patient setup errors. Methods and Materials: Megavoltage DRRs were generated by ray tracing through a modified volumetric CT data set in which CT numbers were converted into linear attenuation coefficients for the therapeutic beam energy. The DRR transmission image was transformed to the grayscale window of the EPI by a histogram-matching technique. An alternative approach was to calibrate the transmission DRR using a measured response curve of the electronic portal imaging device (EPID). This forces the calculated transmission fluence values to be distributed in the same range as that of the EPID image. A cross-correlation technique was used to determine the degree of alignment of the patient anatomy found in the EPID image relative to the reference DRR. Results: Phantom studies demonstrated that the correlation procedure had a standard deviation of 0.5 mm and 0.5 deg. in aligning translational shifts and in-plane rotations. Systematic errors were found between a reference DRR and a reference EPID image. The automated grayscale image-correlation process was completed within 3 s on a workstation computer or 12 s on a PC. Conclusion: The alignment procedure allows the direct comparison of a patient's treatment portal designed with a 3D planning computer with a patient's on-line portal image acquired at the treatment unit. The image registration process is automated to the extent that it requires minimal user intervention, and it is fast and accurate enough for on-line clinical applications

Performance of the Antares large area cold cathode electron gun

International Nuclear Information System (INIS)

Rosocha, L.A.; Mansfield, C.R.

1983-01-01

The performance of the electron gun which supplies ionization for the Antares high power electron beam sustained CO 2 laser power amplifier is described. This electron gun is a coaxial cylindrical cold cathode vacuum triode having a total electron aperture area of approximately 9 m 2 . Electrons are extracted from the gun in pulses of 3-6 μs duration, average current densities of 40-60 ma/cm2, and electron energies of 450-500 keV. The main areas of discussion in this paper are the performance in terms of grid control, current density balance, and current runaway due to breakdown limitations. Comparison of the experimental results with the predictions of a theoretical model for the electron gun will also be presented

Performance of the Antares large area cold cathode electron gun

International Nuclear Information System (INIS)

Rosocha, L.A.; Mansfield, C.R.

1983-01-01

The performance of the electron gun which supplies ionization for the Antares high-power electron-beam-sustained CO 2 -laser power amplifier is described. This electron gun is a coaxial cylindrical cold cathode vacuum triode having a total electron aperture area of approximately 9 m 2 . Electrons are extracted from the gun in pulses of 3 to 6 μs duration, average current densities of 40 to 60 mA/cm 2 , and electron energies of 450 to 500 keV. The main areas of discussion in this paper are the performance in terms of grid control, current-density balance, and current runaway due to breakdown limitations. Comparison of the experimental results with the predictions of a theoretical model for the electron gun are also presented

Dose patient verification during treatment using an amorphous silicon electronic portal imaging device in radiotherapy

International Nuclear Information System (INIS)

Berger, Lucie

2006-01-01

Today, amorphous silicon electronic portal imaging devices (aSi EPID) are currently used to check the accuracy of patient positioning. However, they are not use for dose reconstruction yet and more investigations are required to allow the use of an aSi EPID for routine dosimetric verification. The aim of this work is first to study the dosimetric characteristics of the EPID available at the Institut Curie and then, to check patient dose during treatment using these EPID. First, performance optimization of the Varian aS500 EPID system is studied. Then, a quality assurance system is set up in order to certify the image quality on a daily basis. An additional study on the dosimetric performance of the aS500 EPID is monitored to assess operational stability for dosimetry applications. Electronic portal imaging device is also a useful tool to improve IMRT quality control. The validation and the quality assurance of a portal dose image prediction system for IMRT pre-treatment quality control are performed. All dynamic IMRT fields are verified in clinical routine with the new method based on portal dosimetry. Finally, a new formalism for in vivo dosimetry using transit dose measured with EPID is developed and validated. The absolute dose measurement issue using aSi EPID is described and the midplane dose determination using in vivo dose measurements in combination with portal imaging is used with 3D-conformal-radiation therapy. (author) [fr

Periodic quality control of a linear accelerator using electronic portal imaging

International Nuclear Information System (INIS)

Planes Meseguer, D.; Dorado Rodriguez, M. P.; Esposito, R. D.

2011-01-01

In this paper we present our solution for the realization of the monthly periodic quality control (CP) geometry - mechanical and multi leaf collimator (MLC), using the electronic system for portal imaging (EPI). We have developed specific programs created with free software. The monitoring results are automatically stored on our web server, along with other information generated in our service.

Electronic patient portals: evidence on health outcomes, satisfaction, efficiency, and attitudes: a systematic review.

Science.gov (United States)

Goldzweig, Caroline Lubick; Orshansky, Greg; Paige, Neil M; Towfigh, Ali Alexander; Haggstrom, David A; Miake-Lye, Isomi; Beroes, Jessica M; Shekelle, Paul G

2013-11-19

Patient portals tied to provider electronic health record (EHR) systems are increasingly popular. To systematically review the literature reporting the effect of patient portals on clinical care. PubMed and Web of Science searches from 1 January 1990 to 24 January 2013. Hypothesis-testing or quantitative studies of patient portals tethered to a provider EHR that addressed patient outcomes, satisfaction, adherence, efficiency, utilization, attitudes, and patient characteristics, as well as qualitative studies of barriers or facilitators, were included. Two reviewers independently extracted data and addressed discrepancies through consensus discussion. From 6508 titles, 14 randomized, controlled trials; 21 observational, hypothesis-testing studies; 5 quantitative, descriptive studies; and 6 qualitative studies were included. Evidence is mixed about the effect of portals on patient outcomes and satisfaction, although they may be more effective when used with case management. The effect of portals on utilization and efficiency is unclear, although patient race and ethnicity, education level or literacy, and degree of comorbid conditions may influence use. Limited data for most outcomes and an absence of reporting on organizational and provider context and implementation processes. Evidence that patient portals improve health outcomes, cost, or utilization is insufficient. Patient attitudes are generally positive, but more widespread use may require efforts to overcome racial, ethnic, and literacy barriers. Portals represent a new technology with benefits that are still unclear. Better understanding requires studies that include details about context, implementation factors, and cost.

Rapid portal imaging with a high-efficiency, large field-of-view detector.

Science.gov (United States)

Mosleh-Shirazi, M A; Evans, P M; Swindell, W; Symonds-Tayler, J R; Webb, S; Partridge, M

1998-12-01

The design, construction, and performance evaluation of an electronic portal imaging device (EPID) are described. The EPID has the same imaging geometry as the current mirror-based systems except for the x-ray detection stage, where a two-dimensional (2D) array of 1 cm thick CsI(Tl) detector elements are utilized. The approximately 18% x-ray quantum efficiency of the scintillation detector and its 30 x 40 cm2 field-of-view at the isocenter are greater than other area-imaging EPIDs. The imaging issues addressed are theoretical and measured signal-to-noise ratio, linearity of the imaging chain, influence of frame-summing on image quality and image calibration. Portal images of test objects and a humanoid phantom are used to measure the performance of the system. An image quality similar to the current devices is achieved but with a lower dose. With approximately 1 cGy dose delivered by a 6 MV beam, a 2 mm diam structure of 1.3% contrast and an 18 mm diam object of 0.125% contrast can be resolved without using image-enhancement methods. A spatial resolution of about 2 mm at the isocenter is demonstrated. The capability of the system to perform fast sequential imaging, synchronized with the radiation pulses, makes it suitable for patient motion studies and verification of intensity-modulated beams as well as its application in cone-beam megavoltage computed tomography.

The Muon Portal Project: A large-area tracking detector for muon tomography

Science.gov (United States)

Riggi, F.

2016-05-01

The Muon Portal Project [1] is a joint initiative between research and industrial partners, aimed at the construction of a real size detector protoype to search for hidden high-Z fissile materials inside containers by the muon scattering technique. The detector is based on a set of 48 detection modules (1 m × 3 m), so as to provide four X-Y detection planes, two placed above and two below the container to be inspected. After a research and development phase, which led to the choice and test of the individual components, the construction of the full size detector has already started and will be completed in a few months.

Idiopathic portal hypertension

International Nuclear Information System (INIS)

Han, Tae Kyun; Ryu, Dae Sik; Kim, Heung Chul; Hur, Hun; Eom, Kyeung Tae; Namkung, Sook; Park, Man Soo; Hwang, Woo Chul; Lee, Kwan Seop

1996-01-01

To describe the radiologic findings of idiopathic portal hypertension and to find the points of differentiation between idiopathic portal hypertension and liver cirrhosis. Four portograms in five patients who for four years had suffered from pathologically confirmed idiopathic portal hypertension were retrospectively analyzed and compared with a portogram obtained from a control subject with liver cirrhosis. Portographic finding s of idiopathic portal hypertension were paucity of medium-sized portal branches, irregular and obtuse-angled division of peripheral branches, abrupt interruption and an avascular area beneath the liver margin. A portogram of idiopathic portal hypertension may be useful in differentiation this and liver cirrhosis

Image timing and detector performance of a matrix ion-chamber electronic portal imaging device

International Nuclear Information System (INIS)

Greer, P.

1996-01-01

The Oncology Centre of Auckland Hospital recently purchased a Varian PortalVision TM electronic portal imaging device (EPID). Image acquisition times, input-output characteristics and contrast-detail curves of this matrix liquid ion-chamber EPID have been measured to examine the variation in imaging performance with acquisition mode. The variation in detector performance with acquisition mode has been examined. The HV cycle time can be increased to improve image quality. Consideration should be given to the acquisition mode and HV cycle time used when imaging to ensure adequate imaging performance with reasonable imaging time. (author)

The Muon Portal Project: A large-area tracking detector for muon tomography

Directory of Open Access Journals (Sweden)

Riggi F.

2016-01-01

Full Text Available The Muon Portal Project [1] is a joint initiative between research and industrial partners, aimed at the construction of a real size detector protoype to search for hidden high-Z fissile materials inside containers by the muon scattering technique. The detector is based on a set of 48 detection modules (1 m × 3 m, so as to provide four X-Y detection planes, two placed above and two below the container to be inspected. After a research and development phase, which led to the choice and test of the individual components, the construction of the full size detector has already started and will be completed in a few months.

Electromagnetic surface waves for large-area RF plasma productions between large-area planar electrodes

International Nuclear Information System (INIS)

Nonaka, S.

1992-01-01

Recently, large-area plasma production has been tested by means of a 13.56 MHz radio-frequency (RF) discharge between a pair of large-area planar electrodes, approximately 0.5 m x 1.4 m, as one of the semiconductor technologies for fabrication of large-area amorphous silicon solar cells in the ''Sunshine Project'' of the Agency of Industrial Science and Technology in Japan. We also confirmed long plasma production between a pair of long electrodes. In this paper, normal electromagnetic (EM) waves propagating in a region between a planar waveguide with one plasma and two dielectric layers are analyzed in order to study the feasibility of large-area plasma productions by EM wave-discharges between a pair of large-area RF electrodes larger than the half-wavelength of RF wave. In conclusion, plasmas higher than an electron plasma frequency will be produced by an odd TMoo surface mode. (author) 4 refs., 3 figs

Large-Area High-Performance Flexible Pressure Sensor with Carbon Nanotube Active Matrix for Electronic Skin.

Science.gov (United States)

Nela, Luca; Tang, Jianshi; Cao, Qing; Tulevski, George; Han, Shu-Jen

2018-03-14

Artificial "electronic skin" is of great interest for mimicking the functionality of human skin, such as tactile pressure sensing. Several important performance metrics include mechanical flexibility, operation voltage, sensitivity, and accuracy, as well as response speed. In this Letter, we demonstrate a large-area high-performance flexible pressure sensor built on an active matrix of 16 × 16 carbon nanotube thin-film transistors (CNT TFTs). Made from highly purified solution tubes, the active matrix exhibits superior flexible TFT performance with high mobility and large current density, along with a high device yield of nearly 99% over 4 inch sample area. The fully integrated flexible pressure sensor operates within a small voltage range of 3 V and shows superb performance featuring high spatial resolution of 4 mm, faster response than human skin (<30 ms), and excellent accuracy in sensing complex objects on both flat and curved surfaces. This work may pave the road for future integration of high-performance electronic skin in smart robotics and prosthetic solutions.

Feasibility of megavoltage portal CT using an electronic portal imaging device (EPID) and a multi-level scheme algebraic reconstruction technique (MLS-ART)

International Nuclear Information System (INIS)

Guan, Huaiqun; Zhu, Yunping

1998-01-01

Although electronic portal imaging devices (EPIDs) are efficient tools for radiation therapy verification, they only provide images of overlapped anatomic structures. We investigated using a fluorescent screen/CCD-based EPID, coupled with a novel multi-level scheme algebraic reconstruction technique (MLS-ART), for a feasibility study of portal computed tomography (CT) reconstructions. The CT images might be useful for radiation treatment planning and verification. We used an EPID, set it to work at the linear dynamic range and collimated 6 MV photons from a linear accelerator to a slit beam of 1 cm wide and 25 cm long. We performed scans under a total of ∼200 monitor units (MUs) for several phantoms in which we varied the number of projections and MUs per projection. The reconstructed images demonstrated that using the new MLS-ART technique megavoltage portal CT with a total of 200 MUs can achieve a contrast detectibility of ∼2.5% (object size 5mmx5mm) and a spatial resolution of 2.5 mm. (author)

Maternity patients' access to their electronic medical records: use and perspectives of a patient portal.

Science.gov (United States)

Megan Forster, Megan; Dennison, Kerrie; Callen, Joanne; Andrew, Andrew; Westbrook, Johanna I

Patients have been able to access clinical information from their paper-based health records for a number of years. With the advent of Electronic Medical Records (EMRs) access to this information can now be achieved online using a secure electronic patient portal. The purpose of this study was to investigate maternity patients' use and perceptions of a patient portal developed at the Mater Mothers' Hospital in Brisbane, Australia. A web-based patient portal, one of the first developed and deployed in Australia, was introduced on 26 June 2012. The portal was designed for maternity patients booked at Mater Mothers' Hospital, as an alternative to the paper-based Pregnancy Health Record. Through the portal, maternity patients are able to complete their hospital registration form online and obtain current health information about their pregnancy (via their EMR), as well as access a variety of support tools to use during their pregnancy such as tailored public health advice. A retrospective cross-sectional study design was employed. Usage statistics were extracted from the system for a one year period (1 July 2012 to 30 June 2013). Patients' perceptions of the portal were obtained using an online survey, accessible by maternity patients for two weeks in February 2013 (n=80). Descriptive statistics were employed to analyse the data. Between July 2012 and June 2013, 10,892 maternity patients were offered a patient portal account and access to their EMR. Of those 6,518 created one (60%; 6,518/10,892) and 3,104 went on to request access to their EMR (48%; 3,104/6,518). Of these, 1,751 had their access application granted by 30 June 2013. The majority of maternity patients submitted registration forms online via the patient portal (56.7%). Patients could view their EMR multiple times: there were 671 views of the EMR, 2,781 views of appointment schedules and 135 birth preferences submitted via the EMR. Eighty survey responses were received from EMR account holders, (response

The stability of liquid-filled matrix ionization chamber electronic portal imaging devices for dosimetry purposes

International Nuclear Information System (INIS)

Louwe, R.J.W.; Tielenburg, R.; Ingen, K.M. van; Mijnheer, B.J.; Herk, M.B. van

2004-01-01

This study was performed to determine the stability of liquid-filled matrix ionization chamber (LiFi-type) electronic portal imaging devices (EPID) for dosimetric purposes. The short- and long-term stability of the response was investigated, as well as the importance of factors influencing the response (e.g., temperature fluctuations, radiation damage, and the performance of the electronic hardware). It was shown that testing the performance of the electronic hardware as well as the short-term stability of the imagers may reveal the cause of a poor long-term stability of the imager response. In addition, the short-term stability was measured to verify the validity of the fitted dose-response curve immediately after beam startup. The long-term stability of these imagers could be considerably improved by correcting for room temperature fluctuations and gradual changes in response due to radiation damage. As a result, the reproducibility was better than 1% (1 SD) over a period of two years. The results of this study were used to formulate recommendations for a quality control program for portal dosimetry. The effect of such a program was assessed by comparing the results of portal dosimetry and in vivo dosimetry using diodes during the treatment of 31 prostate patients. The improvement of the results for portal dosimetry was consistent with the deviations observed with the reproducibility tests in that particular period. After a correction for the variation in response of the imager, the average difference between the measured and prescribed dose during the treatment of prostate patients was -0.7%±1.5% (1 SD), and -0.6%±1.1% (1 SD) for EPID and diode in vivo dosimetry, respectively. It can be concluded that a high stability of the response can be achieved for this type of EPID by applying a rigorous quality control program

Highly segmented large-area hybrid photodiodes with bialkali photocathodes and enclosed VLSI readout electronics

CERN Document Server

Braem, André; Filthaut, Frank; Go, A; Joram, C; Weilhammer, Peter; Wicht, P; Dulinski, W; Séguinot, Jacques; Wenzel, H; Ypsilantis, Thomas

2000-01-01

We report on the principles, design, fabrication, and operation of a highly segmented, large-area hybrid photodiode, which is being developed in the framework of the LHCb RICH project. The device consists of a cylindrical, 127 mm diameter vacuum envelope capped with a spherical borosilicate UV-glass entrance window, with an active-to-total-area fraction of 81A fountain-focusing electron optics is used to demagnify the image onto a 50 mm diameter silicon sensor, containing 2048 pads of size 1*1 mm/sup 2/. (10 refs).

Duplex sonography in portal hypertension

International Nuclear Information System (INIS)

Kwon, Hyuk Po; Jang, J. C.; Park, B. H.

1990-01-01

We measure the diameter and blood velocity of the portal vein in 50 patients with cirrhosis of the liver and 40 healthy subjects, and calculated cross sectional area, mean blood flow velocity, blood flow volume and congestion index. In patients with cirrhosis of the liver, the cross sectional area of the portal vein was significantly increased: the mean blood flow volume was significantly reduced; the blood flow volume was significantly increased; the congestion index of the portal vein was significantly increased. Duples sonography may play an important role in the diagnosis of portal hypertension

Wall shear stress in portal vein of cirrhotic patients with portal hypertension.

Science.gov (United States)

Wei, Wei; Pu, Yan-Song; Wang, Xin-Kai; Jiang, An; Zhou, Rui; Li, Yu; Zhang, Qiu-Juan; Wei, Ya-Juan; Chen, Bin; Li, Zong-Fang

2017-05-14

To investigate wall shear stress (WSS) magnitude and distribution in cirrhotic patients with portal hypertension using computational fluid dynamics. Idealized portal vein (PV) system models were reconstructed with different angles of the PV-splenic vein (SV) and superior mesenteric vein (SMV)-SV. Patient-specific models were created according to enhanced computed tomography images. WSS was simulated by using a finite-element analyzer, regarding the blood as a Newtonian fluid and the vessel as a rigid wall. Analysis was carried out to compare the WSS in the portal hypertension group with that in healthy controls. For the idealized models, WSS in the portal hypertension group (0-10 dyn/cm 2 ) was significantly lower than that in the healthy controls (10-20 dyn/cm 2 ), and low WSS area (0-1 dyn/cm 2 ) only occurred in the left wall of the PV in the portal hypertension group. Different angles of PV-SV and SMV-SV had different effects on the magnitude and distribution of WSS, and low WSS area often occurred in smaller PV-SV angle and larger SMV-SV angle. In the patient-specific models, WSS in the cirrhotic patients with portal hypertension (10.13 ± 1.34 dyn/cm 2 ) was also significantly lower than that in the healthy controls ( P portal hypertension, the low WSS area extended to wider levels and the magnitude of WSS reached lower levels, thereby being more prone to disturbed flow occurrence. Cirrhotic patients with portal hypertension show dramatic hemodynamic changes with lower WSS and greater potential for disturbed flow, representing a possible causative factor of PV thrombosis.

First clinical tests using a liquid-filled electronic portal imaging device and a convolution model for the verification of the midplane dose

International Nuclear Information System (INIS)

Boellaard, R.; Herk, M. van; Uiterwaal, H.; Mijnheer, B.

1998-01-01

Background and purpose: Recently, algorithms have been developed to derive the patient dose from portal dose measurements using a liquid-filled electronic portal imaging device. These algorithms have already been validated for several phantom geometries irradiated under clinical conditions. It is the aim of the present study to investigate the applicability of a liquid-filled electronic portal imaging device in combination with these algorithms for two-dimensional midplane dose verification in clinical practice. Measurements and methods: Portal dose images were obtained during several patient treatments under routine clinical conditions. Measurements were performed to verify the midplane dose during radiotherapy of larynx cancer with 4 MV beams, breast and lung cancer with 8 MV beams and prostate cancer with both 8 and 18 MV beams. Midplane doses, determined from portal dose measurements and analyzed with our algorithms, were compared with midplane doses calculated with our three-dimensional (3D) treatment planning system (TPS). Results: For the larynx treatment the measured 2D midplane dose agreed within 2.0% with TPS calculations in most parts of the field. Larger differences were found in a small region below the skin due to the absence of electron equilibrium, which is not taken into account in our portal dose analysis. For breast irradiations the measured midplane dose showed a homogeneous distribution in the AP direction in the axial plane, while high dose regions were observed in the cranial and caudal part of the breast. Portal dose measurements and TPS calculations agreed within 2.5% for most of the prostate and lung irradiations. For a few of the prostate and lung treatments larger local differences were found due to differences between the actual patient anatomy and the planning CT data, e.g. as a result of variable gas filling in the rectum and anatomical changes in the lung. Conclusions: Portal dose measurements with a liquid-filled electronic portal

Distinct DNA exit and packaging portals in the virus Acanthamoeba polyphaga mimivirus.

Science.gov (United States)

Zauberman, Nathan; Mutsafi, Yael; Halevy, Daniel Ben; Shimoni, Eyal; Klein, Eugenia; Xiao, Chuan; Sun, Siyang; Minsky, Abraham

2008-05-13

Icosahedral double-stranded DNA viruses use a single portal for genome delivery and packaging. The extensive structural similarity revealed by such portals in diverse viruses, as well as their invariable positioning at a unique icosahedral vertex, led to the consensus that a particular, highly conserved vertex-portal architecture is essential for viral DNA translocations. Here we present an exception to this paradigm by demonstrating that genome delivery and packaging in the virus Acanthamoeba polyphaga mimivirus occur through two distinct portals. By using high-resolution techniques, including electron tomography and cryo-scanning electron microscopy, we show that Mimivirus genome delivery entails a large-scale conformational change of the capsid, whereby five icosahedral faces open up. This opening, which occurs at a unique vertex of the capsid that we coined the "stargate", allows for the formation of a massive membrane conduit through which the viral DNA is released. A transient aperture centered at an icosahedral face distal to the DNA delivery site acts as a non-vertex DNA packaging portal. In conjunction with comparative genomic studies, our observations imply a viral packaging pathway akin to bacterial DNA segregation, which might be shared by diverse internal membrane-containing viruses.

Distinct DNA exit and packaging portals in the virus Acanthamoeba polyphaga mimivirus.

Directory of Open Access Journals (Sweden)

Nathan Zauberman

2008-05-01

Full Text Available Icosahedral double-stranded DNA viruses use a single portal for genome delivery and packaging. The extensive structural similarity revealed by such portals in diverse viruses, as well as their invariable positioning at a unique icosahedral vertex, led to the consensus that a particular, highly conserved vertex-portal architecture is essential for viral DNA translocations. Here we present an exception to this paradigm by demonstrating that genome delivery and packaging in the virus Acanthamoeba polyphaga mimivirus occur through two distinct portals. By using high-resolution techniques, including electron tomography and cryo-scanning electron microscopy, we show that Mimivirus genome delivery entails a large-scale conformational change of the capsid, whereby five icosahedral faces open up. This opening, which occurs at a unique vertex of the capsid that we coined the "stargate", allows for the formation of a massive membrane conduit through which the viral DNA is released. A transient aperture centered at an icosahedral face distal to the DNA delivery site acts as a non-vertex DNA packaging portal. In conjunction with comparative genomic studies, our observations imply a viral packaging pathway akin to bacterial DNA segregation, which might be shared by diverse internal membrane-containing viruses.

The cumulative verification image analysis tool for offline evaluation of portal images

International Nuclear Information System (INIS)

Wong, John; Yan Di; Michalski, Jeff; Graham, Mary; Halverson, Karen; Harms, William; Purdy, James

1995-01-01

Purpose: Daily portal images acquired using electronic portal imaging devices contain important information about the setup variation of the individual patient. The data can be used to evaluate the treatment and to derive correction for the individual patient. The large volume of images also require software tools for efficient analysis. This article describes the approach of cumulative verification image analysis (CVIA) specifically designed as an offline tool to extract quantitative information from daily portal images. Methods and Materials: The user interface, image and graphics display, and algorithms of the CVIA tool have been implemented in ANSCI C using the X Window graphics standards. The tool consists of three major components: (a) definition of treatment geometry and anatomical information; (b) registration of portal images with a reference image to determine setup variation; and (c) quantitative analysis of all setup variation measurements. The CVIA tool is not automated. User interaction is required and preferred. Successful alignment of anatomies on portal images at present remains mostly dependent on clinical judgment. Predefined templates of block shapes and anatomies are used for image registration to enhance efficiency, taking advantage of the fact that much of the tool's operation is repeated in the analysis of daily portal images. Results: The CVIA tool is portable and has been implemented on workstations with different operating systems. Analysis of 20 sequential daily portal images can be completed in less than 1 h. The temporal information is used to characterize setup variation in terms of its systematic, random and time-dependent components. The cumulative information is used to derive block overlap isofrequency distributions (BOIDs), which quantify the effective coverage of the prescribed treatment area throughout the course of treatment. Finally, a set of software utilities is available to facilitate feedback of the information for

Noncirrhotic portal hypertension.

Science.gov (United States)

Da, Ben L; Koh, Christopher; Heller, Theo

2018-05-01

Noncirrhotic portal hypertension represents a heterogeneous group of liver disorders that is characterized by portal hypertension in the absence of cirrhosis. The purpose of this review is to serve as a guide on how to approach a patient with noncirrhotic portal hypertension with a focus on recent developments. Recent studies pertaining to noncirrhotic portal hypertension have investigated aetiological causes, mechanisms of disease, noninvasive diagnostic modalities, clinical characteristics in the paediatric population and novel treatment targets. Noncirrhotic portal hypertension is an underappreciated clinical entity that can be difficult to diagnosis without a healthy suspicion. Diagnosis then relies on a comprehensive understanding of the causes and clinical manifestations of this disease, as well as a careful interpretation of the liver biopsy. Noninvasive approaches to diagnosis may play a significant role moving forward in this disease. Treatment in NCPH remains largely targeted at the individual sequalae of portal hypertension.

Using an electronic portal imaging device for exit dose measurements in radiotherapy

International Nuclear Information System (INIS)

Ganowicz, M.; Wozniak, B.; Bekman, A.; Maniakowski, Z.

2003-01-01

To present a method of determining the exit dose with the use of an electronic portal imaging device (EPID). The device used was the Portal Vision LC250 (Varian). The EPID signals on the central beam axis have been related to the exit dose. The exit dose measurements were performed with the ionisation chamber in the slab phantom at the distance of dose maximum from the exit surface of the phantom. EPID reading was investigated as a function of field size, phantom thickness and source-detector distance. The relation between dose rate and the EPID reading is described with empirical functions applicable to the obtained data. The exit dose is calculated from the EPID reading as a product of the calibration factor and appropriate correction factors. The determination of the exit dose rate from the EPID signal requires the knowledge of many parameters and earlier determination of essential characteristics. (author)

Fabrication, characterization and testing of silicon photomultipliers for the Muon Portal Project

International Nuclear Information System (INIS)

La Rocca, P.; Billotta, S.; Blancato, A.A.; Bonanno, D.; Bonanno, G.; Fallica, G.; Garozzo, S.; Lo Presti, D.; Marano, D.; Pugliatti, C.; Riggi, F.; Romeo, G.; Santagati, G.; Valvo, G.

2015-01-01

The Muon Portal is a recently started Project aiming at the construction of a large area tracking detector that exploits the muon tomography technique to inspect the contents of traveling cargo containers. The detection planes will be made of plastic scintillator strips with embedded wavelength-shifting fibres. Special designed silicon photomultipliers will read the scintillation light transported by the fibres along the strips and a dedicated electronics will combine signals from different strips to reduce the overall number of channels, without loss of information. Different silicon photomultiplier prototypes, both with the p-on-n and n-on-p technologies, have been produced by STMicroelectronics during the last years. In this paper we present the main characteristics of the silicon photomultipliers designed for the Muon Portal Project and describe the setup and the procedure implemented for the characterization of these devices, giving some statistical results obtained from the test of a first batch of silicon photomultipliers

Fabrication, characterization and testing of silicon photomultipliers for the Muon Portal Project

Energy Technology Data Exchange (ETDEWEB)

La Rocca, P., E-mail: paola.larocca@ct.infn.it [Dipartimento di Fisica e Astronomia - Catania (Italy); INFN - Sezione di Catania (Italy); Billotta, S. [INAF - Osservatorio Astrofisico di Catania (Italy); Blancato, A.A.; Bonanno, D. [Dipartimento di Fisica e Astronomia - Catania (Italy); Bonanno, G. [INAF - Osservatorio Astrofisico di Catania (Italy); Fallica, G. [STMicroelectronics - Catania (Italy); Garozzo, S. [INAF - Osservatorio Astrofisico di Catania (Italy); Lo Presti, D. [Dipartimento di Fisica e Astronomia - Catania (Italy); INFN - Sezione di Catania (Italy); Marano, D. [INAF - Osservatorio Astrofisico di Catania (Italy); Pugliatti, C.; Riggi, F. [Dipartimento di Fisica e Astronomia - Catania (Italy); INFN - Sezione di Catania (Italy); Romeo, G. [INAF - Osservatorio Astrofisico di Catania (Italy); Santagati, G. [Dipartimento di Fisica e Astronomia - Catania (Italy); INFN - Sezione di Catania (Italy); Valvo, G. [STMicroelectronics - Catania (Italy)

2015-07-01

The Muon Portal is a recently started Project aiming at the construction of a large area tracking detector that exploits the muon tomography technique to inspect the contents of traveling cargo containers. The detection planes will be made of plastic scintillator strips with embedded wavelength-shifting fibres. Special designed silicon photomultipliers will read the scintillation light transported by the fibres along the strips and a dedicated electronics will combine signals from different strips to reduce the overall number of channels, without loss of information. Different silicon photomultiplier prototypes, both with the p-on-n and n-on-p technologies, have been produced by STMicroelectronics during the last years. In this paper we present the main characteristics of the silicon photomultipliers designed for the Muon Portal Project and describe the setup and the procedure implemented for the characterization of these devices, giving some statistical results obtained from the test of a first batch of silicon photomultipliers.

Portal dosimetry in wedged beams

NARCIS (Netherlands)

Spreeuw, Hanno; Rozendaal, Roel; Camargo, Priscilla; Mans, Anton; Wendling, Markus; Olaciregui-Ruiz, Igor; Sonke, Jan-Jakob; van Herk, Marcel; Mijnheer, Ben

2015-01-01

Portal dosimetry using electronic portal imaging devices (EPIDs) is often applied to verify high-energy photon beam treatments. Due to the change in photon energy spectrum, the resulting dose values are, however, not very accurate in the case of wedged beams if the pixel-to-dose conversion for the

Moving strip technique of electron beam therapy

Energy Technology Data Exchange (ETDEWEB)

Matsushima, Kishio; Wakasa, Hiroyuki; Oguri, Nobuhiro; Kitayama, Takuichi; Nakagiri, Yoshitada; Mikami, Yasutaka; Hashimoto, Keiji; Hiraki, Yoshio; Aono, Kaname

1984-12-01

The fieldsize in electron beam therapy is determined by the cone size. In case of skin metastasis of a malignant tumor and so on, which need a large field size and whose area is much larger than the size of the cone, a large field size is usually produced by dividing the portals. However, the dose distribution at the border of the field becomes unequal, and hot and cold dose areas are produced according to the distance between portals. We tried the strip field technique in a large field along the long axis of the body in order to flatten the dose of the border employing the moving strip used for whole abdominal irradiation in ovarian cancer. We set the film in Mix-DP and used the strip field technique with 2.5cm steps. We discussed the relationship between the interval (distance between portals) and the flattening of the dose within the field. Skin movement due to breathing and influences on the flattening of the dose were considered. The proper flatness was obtained at depths of 0,1,2, and 3cm by setting the interval at 0.5cm. When skin movement was produced by breathing in +-1.5mm, the proper flaness was obtained also at a 0.5-cm interval. It seems that smoothing is increased by breathing. An ''electron beam moving strip'' with a 2.5-cm step and 0.5-cm interval was clinically effective in the treatment of patients with skin metastasis of colon cancer. (author).

Web-based Service Portal in Healthcare

Science.gov (United States)

Silhavy, Petr; Silhavy, Radek; Prokopova, Zdenka

Information delivery is one the most important task in healthcare. The growing sector of electronic healthcare has an important impact on the information delivery. There are two basic approaches towards information delivering. The first is web portal and second is touch-screen terminal. The aim of this paper is to investigate the web-based service portal. The most important advantage of web-based portal in the field of healthcare is an independent access for patients. This paper deals with the conditions and frameworks for healthcare portals

ICPP digital wide area portal monitor

International Nuclear Information System (INIS)

Nichols, C.E.

1978-01-01

A portal montior is described which is used to check personnel for contamination. The monitor is extremely sensitive. In addition to personnel contamination control, it serves as an extremely effective SNM detector capable of detecting U-235 in half the quantities specified in Federal Standards

Improving diabetes management with a patient portal: a qualitative study of diabetes self-management portal.

Science.gov (United States)

Urowitz, Sara; Wiljer, David; Dupak, Kourtney; Kuehner, Zachary; Leonard, Kevin; Lovrics, Emily; Picton, Peter; Seto, Emily; Cafazzo, Joe

2012-11-30

Effective management and care of diabetes is crucial to reducing associated risks such as heart disease and kidney failure. With increasing access and use of the Internet, online chronic disease management is being explored as a means of providing patients with support and the necessary tools to monitor and manage their disease. The objective of our study was to evaluate the experience of patients and providers using an online diabetes management portal for patients. Participants were recruited from a large sample population of 887 for a follow-up questionnaire to be completed after 6 months of using the patient portal. Participants were presented with the option to participate in an additional interview and, if the participant agreed, a time and date was scheduled for the interview. A 5-item, open-ended questionnaire was used to capture providers' opinions of the patient portal. Providers included general practitioners (GPs), nurses, nurse practitioners (NPs), dieticians, diabetes educators (DECs), and other clinical staff. A total of 854 patients were consented for the questionnaire. Seventeen (8 male, 9 female) patients agreed to participate in a telephone interview. Sixty-four health care providers completed the five open-ended questions; however, an average of 48.2 responses were recorded per question. Four major themes were identified and will be discussed in this paper. These themes have been classified as: facilitators of disease management, barriers to portal use, patient-provider communication and relationship, and recommendations for portal improvements. This qualitative study shows that online chronic disease management portals increase patient access to information and engagement in their health care, but improvements in the portal itself may improve usability and reduce attrition. Furthermore, this study identifies a grey area that exists in the roles that GPs and AHPs should play in the facilitation of online disease management.

Congestive index of portal vein

International Nuclear Information System (INIS)

Kim, Won Ho; Kim, H. K.; Lee, S. C.; Han, S. H.; Han, K. H.; Chung, J. B.; Choi, H. J.

1989-01-01

In patients with portal hypertension, the blood flow volume is maintained despite decreased blood flow velocity due to enlargement of the vascular cross sectional area. Thus, the 'congestion index' of the portal vein, which is the ratio between the cross sectional area (cm2) and the blood flow velocity (cm/sec) determined by a Doppler ultrasonography, may be a sensitive index by which to assess portal hypertension. We performed Doppler ultrasonography on 24 normal subjects, 14 patients with biopsy proved chronic active hepatitis and 55 patients with liver cirrhosis in order to assess the diagnostic value of the congestion index. The cross sectional area of the portal vein was significantly enlarged and the mean blood flow velocity was significantly reduced in patients with liver cirrhosis compared with controls. However, the blood flow volume was no difference. The congestion index of the portal vein was significantly increased in patients with liver cirrhosis (0.113+0.035) compared with patients with chronic active hepatitis(0.078+0.029) (p<0.001) and controls (0.053+0.016) (p<0.001). The sensitivity, specificity and predictability of the congestion index for detection of patients with the cirrhosis of the liver were 76.4%, 100% and 100% respectively, when the normal range was set at mean+2SD. The results suggest that the congestion index of the portal vein may pla a significant role in diagnosis of portal hypertensive patients

Level-set segmentation of pulmonary nodules in megavolt electronic portal images using a CT prior

International Nuclear Information System (INIS)

Schildkraut, J. S.; Prosser, N.; Savakis, A.; Gomez, J.; Nazareth, D.; Singh, A. K.; Malhotra, H. K.

2010-01-01

Purpose: Pulmonary nodules present unique problems during radiation treatment due to nodule position uncertainty that is caused by respiration. The radiation field has to be enlarged to account for nodule motion during treatment. The purpose of this work is to provide a method of locating a pulmonary nodule in a megavolt portal image that can be used to reduce the internal target volume (ITV) during radiation therapy. A reduction in the ITV would result in a decrease in radiation toxicity to healthy tissue. Methods: Eight patients with nonsmall cell lung cancer were used in this study. CT scans that include the pulmonary nodule were captured with a GE Healthcare LightSpeed RT 16 scanner. Megavolt portal images were acquired with a Varian Trilogy unit equipped with an AS1000 electronic portal imaging device. The nodule localization method uses grayscale morphological filtering and level-set segmentation with a prior. The treatment-time portion of the algorithm is implemented on a graphical processing unit. Results: The method was retrospectively tested on eight cases that include a total of 151 megavolt portal image frames. The method reduced the nodule position uncertainty by an average of 40% for seven out of the eight cases. The treatment phase portion of the method has a subsecond execution time that makes it suitable for near-real-time nodule localization. Conclusions: A method was developed to localize a pulmonary nodule in a megavolt portal image. The method uses the characteristics of the nodule in a prior CT scan to enhance the nodule in the portal image and to identify the nodule region by level-set segmentation. In a retrospective study, the method reduced the nodule position uncertainty by an average of 40% for seven out of the eight cases studied.

Automated detection of a prostate Ni-Ti stent in electronic portal images

OpenAIRE

Carl, Jesper; Nielsen, Henning; Nielsen, Jane; Lund, Bente; Larsen, Erik Hoejkjaer

2006-01-01

  Udgivelsesdato: DEC  Planning target volumes (PTV) in fractionated radiotherapy still have to be outlined with wide margins to the clinical target volume due to uncertainties arising from daily shift of the prostate position. A recently proposed new method of visualization of the prostate is based on insertion of a thermo-expandable Ni-Ti stent. The current study proposes a new detection algorithm for automated detection of the Ni-Ti stent in electronic portal images. The algorithm is ba...

Computer tomographic findings in portal hypertension due to cirrhosis of the liver. Pt. 1

International Nuclear Information System (INIS)

Koester, O.; Kunz, R.; Fischer, P.; Lackner, K.; Koischwitz, D.; Bonn Univ.

1983-01-01

The CT findings in 80 patients with confirmed portal hypertension due to intrahepatic block were analysed retrospectively. The findings included ascites, hypo-dense areas in the liver, nodular or irregular liver contour, the inability of define intrahepatic portal vessels with narrow window settings, the so-called ''kissing'' sign and evidence of hepato-fugal collaterals and thickning of the wall of the oesophagus. Electronic measurements of various organs (liver, spleen) and vessel diameters (portal vein, superior mesenteric vein) provide parameters which permit classification of patients into the cirrhotic group, as compared with a control group. The statistical significance of this classification was checked by the Kolmogoroff-Smirnoff test. (orig.)

Computer tomographic findings in portal hypertension due to cirrhosis of the liver. Pt. 1

Energy Technology Data Exchange (ETDEWEB)

Koester, O; Kunz, R; Fischer, P; Lackner, K; Koischwitz, D

1983-06-01

The CT findings in 80 patients with confirmed portal hypertension due to intrahepatic block were analysed retrospectively. The findings included ascites, hypo-dense areas in the liver, nodular or irregular liver contour, the inability of define intrahepatic portal vessels with narrow window settings, the so-called ''kissing'' sign and evidence of hepato-fugal collaterals and thickening of the wall of the oesophagus. Electronic measurements of various organs (liver, spleen) and vessel diameters (portal vein, superior mesenteric vein) provide parameters which permit classification of patients into the cirrhotic group, as compared with a control group. The statistical significance of this classification was checked by the Kolmogoroff-Smirnoff test.

Optimization of the electron collection efficiency of a large area MCP-PMT for the JUNO experiment

International Nuclear Information System (INIS)

Chen, Lin; Tian, Jinshou; Liu, Chunliang; Wang, Yifang; Zhao, Tianchi; Liu, Hulin; Wei, Yonglin; Sai, Xiaofeng; Chen, Ping; Wang, Xing; Lu, Yu; Hui, Dandan; Guo, Lehui; Liu, Shulin; Qian, Sen; Xia, Jingkai; Yan, Baojun; Zhu, Na; Sun, Jianning; Si, Shuguang

2016-01-01

A novel large-area (20-inch) photomultiplier tube based on microchannel plate (MCP-PMTs) is proposed for the Jiangmen Underground Neutrino Observatory (JUNO) experiment. Its photoelectron collection efficiency C e is limited by the MCP open area fraction (A open ). This efficiency is studied as a function of the angular (θ), energy (E) distributions of electrons in the input charge cloud and the potential difference (U) between the PMT photocathode and the MCP input surface, considering secondary electron emission from the MCP input electrode. In CST Studio Suite, Finite Integral Technique and Monte Carlo method are combined to investigate the dependence of C e on θ, E and U. Results predict that C e can exceed A open , and are applied to optimize the structure and operational parameters of the 20-inch MCP-PMT prototype. C e of the optimized MCP-PMT is expected to reach 81.2%. Finally, the reduction of the penetration depth of the MCP input electrode layer and the deposition of a high secondary electron yield material on the MCP are proposed to further optimize C e .

Characterization of an electronic system for Image acquisition portal to open field dosimetry; Caracterizacao de um sistema eletronico de aquisicao de imagem portal para dosimetria em radioterapia

Energy Technology Data Exchange (ETDEWEB)

Barbi, Gustavo L.; Oliveira, Harley F.; Bertucci, Edenyse C.; Amaral, Leonardo L.; Borges, Leandro F., E-mail: gustavobarbi@usp.br [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Hospital das Clinicas. Centro de Ciencias das Imagens e Fisica Medica

2012-08-15

The objective was to characterize and enable an electronic portal imaging device (EPID) to use like a portal dosimetry device - PDI, in non-transit mode, without interposition of scattering between the beam and EPID for measurement to open fields. The images as well as the DICOM header data are extracted from software ImageJ and the information are used in the basic algorithm for converting pixel to dose. The linearity and reproducibility of response were analyzed, and the maximum deviation found of 2,3% to 800 monitor units (MU) for linearity and -0,9% for reproducibility of signal measured daily. A 512x512 matrix with a resolution of 0,8mm was established to restore the shape of beam from the image. The field size dependence was evaluated, by obtaining the ratio of total scattering of ionization chamber and EPID. Finally, a calibration factor of 28470.88{+-}170.73 pixel/cGy was established for the central area of the image. Comparative analyzes between the PDI, radiochromic film and array of ionization chambers (MatriXX) showed good agreement for fields greater then 5 x 5 cm{sup 2} to reestablishment of form field and dose, however, for fields between 3x3 cm{sup 2} and 5x5 cm{sup 2}, the agreement to shape of beam was best established by film. (author)

Periodic quality control of a linear accelerator using electronic portal imaging; Controles de calidad periodicos de un acelerador lineal utilizando el sistema electronico de imagenes portales

Energy Technology Data Exchange (ETDEWEB)

Planes Meseguer, D.; Dorado Rodriguez, M. P.; Esposito, R. D.

2011-07-01

In this paper we present our solution for the realization of the monthly periodic quality control (CP) geometry - mechanical and multi leaf collimator (MLC), using the electronic system for portal imaging (EPI). We have developed specific programs created with free software. The monitoring results are automatically stored on our web server, along with other information generated in our service.

Health literacy and patient portals.

Science.gov (United States)

Gu, Yulong; Orr, Martin; Warren, Jim

2015-06-01

Health literacy has been described as the capacity to obtain, process, and understand basic health information and services needed to make appropriate health decisions. Improving health literacy may serve to promote concordance with therapy, engage patients in their own health care, and improve health outcomes. Patient portal technology aims at enabling patients and families to have easy access to key information in their own medical records and to communicate with their health care providers electronically. However, there is a gap in our understanding of how portals will improve patient outcome. The authors believe patient portal technology presents an opportunity to improve patient concordance with prescribed therapy, if adequate support is provided to equip patients (and family/carers) with the knowledge needed to utilise the health information available via the portals. Research is needed to understand what a health consumer will use patient portals for and how to support a user to realise the technology's potential.

Stability of large-area molecular junctions

NARCIS (Netherlands)

Akkerman, Hylke B.; Kronemeijer, Auke J.; Harkema, Jan; van Hal, Paul A.; Smits, Edsger C. P.; de Leeuw, Dago M.; Blom, Paul W. M.

The stability of molecular junctions is crucial for any application of molecular electronics. Degradation of molecular junctions when exposed to ambient conditions is regularly observed. In this report the stability of large-area molecular junctions under ambient conditions for more than two years

Gas Electron Multipliers: Development of large area GEMs and spherical GEMs

CERN Document Server

Duarte Pinto, Serge; Brock, Ian

2011-01-01

Gaseous radiation detectors have been a crucial part of high-energy physics instrumentation since the 1960s, when the first multiwire proportional counters were built. In the 1990s the first micropattern gas detectors (MPGDs) saw the light; with sub-millimeter feature sizes these novel detectors were faster and more accurate than their predecessors. The gas electron multiplier (GEM) is one of the most successful of these technologies. It is a charge multiplication structure made from a copper clad polymer foil, pierced with a regular and dense pattern of holes. I will describe the properties and the application of GEMs and GEM detectors, and the research and development I have done on this technology. Two of the main objectives were the development of large area GEMs (~m^2) for particle physics experiments and GEMs with a spherical shape for x-ray or neutron diffraction detectors. Both have been realized, and the new techniques involved are finding their way to applications in research and industry.

Gas electron multipliers. Development of large area GEMS and spherical GEMS

Energy Technology Data Exchange (ETDEWEB)

Pinto, Serge Duarte

2011-08-15

Gaseous radiation detectors have been a crucial part of high-energy physics instrumentation since the 1960s, when the first multiwire proportional counters were built. In the 1990s the first micropattern gas detectors (MPGDS) saw the light; with sub-millimeter feature sizes these novel detectors were faster and more accurate than their predecessors. The gas electron multiplier (GEM) is one of the most successful of these technologies. It is a charge multiplication structure made from a copper clad polymer foil, pierced with a regular and dense pattern of holes. I describe the properties and the application of GEMs and GEM. detectors, and the research and development I have done on this technology. Two of the main objectives were the development of large area GEMs ({proportional_to}m{sup 2}) for particle physics experiments and GEMs with a spherical shape for X-ray or neutron diffraction detectors. Both have been realized, and the new techniques involved are finding their way to applications in research and industry. (orig.)

Gas electron multipliers: Development of large area GEMS and spherical GEMS

International Nuclear Information System (INIS)

Pinto, Serge Duarte

2011-08-01

Gaseous radiation detectors have been a crucial part of high-energy physics instrumentation since the 1960s, when the first multiwire proportional counters were built. In the 1990s the first micropattern gas detectors (MPGDS) saw the light; with sub-millimeter feature sizes these novel detectors were faster and more accurate than their predecessors. The gas electron multiplier (GEM) is one of the most successful of these technologies. It is a charge multiplication structure made from a copper clad polymer foil, pierced with a regular and dense pattern of holes. I describe the properties and the application of GEMs and GEM. detectors, and the research and development I have done on this technology. Two of the main objectives were the development of large area GEMs (∝m 2 ) for particle physics experiments and GEMs with a spherical shape for X-ray or neutron diffraction detectors. Both have been realized, and the new techniques involved are finding their way to applications in research and industry. (orig.)

Advances in the treatment of portal hypertension in cirrhosis.

Science.gov (United States)

Kimer, N; Wiese, S; Mo, S; Møller, S; Bendtsen, F

2016-08-01

Non-selective beta-blockers and handling of esophageal varices has been key elements in the treatment of portal hypertension in recent decades. Liver vein catheterization has been essential in diagnosis and monitoring of portal hypertension, but ongoing needs for noninvasive tools has led to research in areas of both biomarkers, and transient elastography, which displays promising results in discerning clinically significant portal hypertension. Novel research into the areas of hepatic stellate cell function and the dynamic components of portal hypertension has revealed promising areas of treatment modalities, targeting intestinal decontamination, angiogenesis, inflammation and oxidative stress. Future studies may reveal if these initiatives lead to developments of new drugs for treatment of portal hypertension.

Advances in the treatment of portal hypertension in cirrhosis

DEFF Research Database (Denmark)

Kimer, Nina; Wiese, S; Mo, S S

2016-01-01

Non-selective beta-blockers and handling of esophageal varices has been key elements in the treatment of portal hypertension in recent decades. Liver vein catheterization has been essential in diagnosis and monitoring of portal hypertension, but ongoing needs for noninvasive tools has led...... to research in areas of both biomarkers, and transient elastography, which displays promising results in discerning clinically significant portal hypertension. Novel research into the areas of hepatic stellate cell function and the dynamic components of portal hypertension has revealed promising areas...... of treatment modalities, targeting intestinal decontamination, angiogenesis, inflammation and oxidative stress. Future studies may reveal if these initiatives lead to developments of new drugs for treatment of portal hypertension....

Impact and user satisfaction of a clinical information portal embedded in an electronic health record.

Science.gov (United States)

Tannery, Nancy H; Epstein, Barbara A; Wessel, Charles B; Yarger, Frances; LaDue, John; Klem, Mary Lou

2011-01-01

In 2008, a clinical information tool was developed and embedded in the electronic health record system of an academic medical center. In 2009, the initial information tool, Clinical-e, was superseded by a portal called Clinical Focus, with a single search box enabling a federated search of selected online information resources. To measure the usefulness and impact of Clinical Focus, a survey was used to gather feedback about users' experience with this clinical resource. The survey determined what type of clinicians were using this tool and assessed user satisfaction and perceived impact on patient care decision making. Initial survey results suggest the majority of respondents found Clinical Focus easy to navigate, the content easy to read, and the retrieved information relevant and complete. The majority would recommend Clinical Focus to their colleagues. Results indicate that this tool is a promising area for future development.

Development of a model using narrow slit beam profiles to account for the backscatter response of an amorphous silicon electronic portal imaging device

International Nuclear Information System (INIS)

Maria Das, K.J.; Ostapiak, Orest

2008-01-01

An electronic portal imaging device (EPID), currently used for determining proper patient placement during irradiation in a radiotherapy treatment, can also be used for the purpose of pre- treatment IMRT QA. However, the Varian aS500 portal imager exhibits dosimetric artifacts caused by non-uniform backscatter from mechanical support structures located behind the imager

Detection of organ movement in cervix cancer patients using a fluoroscopic electronic portal imaging device and radiopaque markers

International Nuclear Information System (INIS)

Kaatee, Robert S.J.P.; Olofsen, Manouk J.J.; Verstraate, Marjolein B.J.; Quint, Sandra; Heijmen, Ben J.M.

2002-01-01

Purpose: To investigate the use of a fluoroscopic electronic portal imaging device (EPID) and radiopaque markers to detect internal cervix movement. Methods and Materials: For 10 patients with radiopaque markers clamped to the cervix, electronic portal images were made during external beam irradiation. Bony structures and markers in the portal images were registered with the same structures in the corresponding digitally reconstructed radiographs of the planning computed tomogram. Results: The visibility of the markers in the portal images was good, but their fixation should be improved. Generally, the correlation between bony structure displacements and marker movement was poor, the latter being substantially larger. The standard deviations describing the systematic and random bony anatomy displacements were 1.2 and 2.6 mm, 1.7 and 2.9 mm, and 1.6 and 2.7 mm in the lateral, cranial-caudal, and dorsal-ventral directions, respectively. For the marker movement those values were 3.4 and 3.4 mm, 4.3 and 5.2 mm, 3.2 and 5.2 mm, respectively. Estimated clinical target volume to planning target volume (CTV-PTV) planning margins (∼11 mm) based on the observed overall marker displacements (bony anatomy + internal cervix movement) are only marginally larger than the margins required to account for internal marker movement alone. Conclusions: With our current patient setup techniques and methods of setup verification and correction, the required CTV-PTV margins are almost fully determined by internal organ motion. Setup verification and correction using radiopaque markers might allow decreasing those margins, but technical improvements are needed

Study on the dose response characteristics of a scanning liquid ion-chamber electronic portal imaging device

CERN Document Server

Ma Shao Gang; Song Yi Xin

2002-01-01

Objective: To study the dose response characteristics and the influence factors such as gantry angle, field size and acquisition mode on the dosimetric response curves, when using a scanning liquid ion-chamber electronic portal imaging device (EPID) for dose verification. Methods: All experiments were carried out on a Varian 600 C/D accelerator (6 MV X-ray) equipped with a Varian PortalVision sup T sup M MK2 type EPID. To obtain the dose response curve, the relationship between the incident radiation intensity to the detector and the pixel value output from the EPID were established. Firstly, the different dose rates of 6 MV X-rays were obtained by varying SSD. Secondly, three digital portal images were acquired for each dose rate using the EPID and averaged to avoid the influence of the dose rate fluctuations of the accelerator. The pixel values of all images were read using self-designed image analysis software, and and average for a region consisting of 11 x 11 pixels around the center was taken as the res...

Assessment of Set-up Accuracy in Tangential Breast Treatment Using Electronic Portal Imaging Device

International Nuclear Information System (INIS)

Lee, Byung Koo; Kang, Soo Man

2012-01-01

The aim of this study was to investigate the setup accuracy for tangential breast treatment patients using electronic portal image and 2-D reconstruction image Twenty two patients undergoing tangential breast treatment. To explore the setup accuracy, distances between chosen landmarks were taken as reference parameters. The difference between measured reference parameters on simulation films and electronic portal images (EPIs) was calculated as the setup error. A total of 22 simulation films and 110 EPIs were evaluated. In the tangential fields, the calculated reference parameters were the central lung distance (CLD), central soft-tissue distance (CSTD), and above lung distance (ALD), below lung distance (BLD). In the medial tangential field, the average difference values for these parameters were 1.0, -6.4, -2.1 and 2.0, respectively; and the values were 1.5, 2.3, 4.1 and 1.1, respectively. In the lateral tangential field, the average difference values for these parameters were -1.5, -4.3, -2.7 and -1.3, respectively; and the values were 3.3, 2.1, 2.9 and 2.5, respectively. CLD, CSTD, ALD and BLD in the tangential fields are easily identifiable and are helpful for detecting setup errors using EPIs in patients undergoing tangential breast radiotherapy treatment.

Assessment of Set-up Accuracy in Tangential Breast Treatment Using Electronic Portal Imaging Device

Energy Technology Data Exchange (ETDEWEB)

Lee, Byung Koo [Dept. of Radiation Oncology, Korea University Anam Hospital, Seoul (Korea, Republic of); Kang, Soo Man [Dept. of Radiation Oncology, Korea University Gospel Hospital, Seoul (Korea, Republic of)

2012-09-15

The aim of this study was to investigate the setup accuracy for tangential breast treatment patients using electronic portal image and 2-D reconstruction image Twenty two patients undergoing tangential breast treatment. To explore the setup accuracy, distances between chosen landmarks were taken as reference parameters. The difference between measured reference parameters on simulation films and electronic portal images (EPIs) was calculated as the setup error. A total of 22 simulation films and 110 EPIs were evaluated. In the tangential fields, the calculated reference parameters were the central lung distance (CLD), central soft-tissue distance (CSTD), and above lung distance (ALD), below lung distance (BLD). In the medial tangential field, the average difference values for these parameters were 1.0, -6.4, -2.1 and 2.0, respectively; and the values were 1.5, 2.3, 4.1 and 1.1, respectively. In the lateral tangential field, the average difference values for these parameters were -1.5, -4.3, -2.7 and -1.3, respectively; and the values were 3.3, 2.1, 2.9 and 2.5, respectively. CLD, CSTD, ALD and BLD in the tangential fields are easily identifiable and are helpful for detecting setup errors using EPIs in patients undergoing tangential breast radiotherapy treatment.

Assessment of flatness and symmetry of megavoltage x-ray beam with an electronic portal imaging device

CERN Document Server

Liu, G; Bezak, E

2002-01-01

The input/output characteristics of the Wellhofer BIS 710 electronic portal imaging device (EPID) have been investigated to establish its efficacy for periodic quality assurance (QA) applications. Calibration curves have been determined for the energy fluence incident on the detector versus the pixel values. The effect of the charge coupled device (CCD) camera sampling time and beam parameters (such as beam field size, dose rate, photon energy) on the calibration have been investigated for a region of interest (ROI) around the central beam axis. The results demonstrate that the pixel output is a linear function of the incident exposure, as expected for a video-based electronic portal imaging system. The field size effects of the BIS 710 are similar to that of an ion chamber for smaller field sizes up to 10 x 10 cm sup 2. However, for larger field sizes the pixel value increases more rapidly. Furthermore, the system is slightly sensitive to dose rate and is also energy dependent. The BIS 710 has been used in t...

Meaningful Use of a Confidential Adolescent Patient Portal.

Science.gov (United States)

Thompson, Lindsay A; Martinko, Thomas; Budd, Pamela; Mercado, Rebeccah; Schentrup, Anzeela M

2016-02-01

To design and evaluate the usage of an adolescent patient portal specifically adapted for adolescent health care needs that also satisfied institutional meaningful use guidelines regarding electronic health records. Key stakeholders at one academic health care center adopted an online portal and opted to designate a patient portal specifically for adolescents to maximize confidentiality in compliance with state privacy laws. This study analyzed aggregate electronic health record data of adolescents' (ages 12-17.9 years) uptake, usage, and functionality of this portal and compared it to parent portal usage for younger children (ages 0-11 years). Differences in means were calculated using paired t tests. The portal was used similarly between parents of young children and adolescents, with almost 1,000 enrollees in each group from September 1, 2012 to March 31, 2015. There were no gender differences in enrollment. Adolescents were less likely than parents of younger children to review appointments (73% vs. 85%), laboratory tests (67% vs. 79%), problem lists (40% vs. 78%), or allergies (45% vs. 77%, all p values adolescents sent 1,397 confidential messages. Institutional decisions for implementing meaningful use requirements can align with goals of adolescent health. Patient portals can enhance adolescent health care quality and adolescents readily use a confidential portal. Implementation of meaningful use requirements should be checked against adolescent health care needs to maximize confidentiality and promote health communication. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Verification of setup errors in external beam radiation therapy using electronic portal imaging

International Nuclear Information System (INIS)

Krishna Murthy, K.; Al-Rahbi, Zakiya; Sivakumar, S.S.; Davis, C.A.; Ravichandran, R.

2008-01-01

The objective of this study was to conduct an audit on QA aspects of treatment delivery by the verification of the treatment fields position on different days to document the efficiency of immobilization methods and reproducibility of treatment. A retrospective study was carried out on 60 patients, each 20 treated for head and neck, breast, and pelvic sites; and a total of 506 images obtained by electronic portal imaging device (EPID) were analyzed. The portal images acquired using the EPID systems attached to the Varian linear accelerators were superimposed on the reference images. The anatomy matching software (Varian portal Vision. 6.0) was used, and the displacements in two dimensions and rotation were noted for each treated field to study the patient setup errors. The percentages of mean deviations more than 3 mm in lateral (X) and longitudinal (Y) directions were 17.5%, 11.25%, and 7.5% for breast, pelvis, and head and neck cases respectively. In all cases, the percentage of mean deviation with more than 5 mm error was 0.83%. The maximum average mean deviation in all the cases was 1.87. The average mean SD along X and Y directions in all the cases was less than 2.65. The results revealed that the ranges of setup errors are site specific and immobilization methods improve reproducibility. The observed variations were well within the limits. The study confirmed the accuracy and quality of treatments delivered to the patients. (author)

Optimization of the electron collection efficiency of a large area MCP-PMT for the JUNO experiment

Energy Technology Data Exchange (ETDEWEB)

Chen, Lin, E-mail: chenlin@opt.cn [State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics (XIOPM), Chinese Academy of Sciences (CAS), Xi’an 710119 (China); Graduate School of Chinese Academy of Sciences (CAS), Beijing 100049 (China); Xi’an Jiaotong University, Xi’an 710049 (China); Tian, Jinshou [Graduate School of Chinese Academy of Sciences (CAS), Beijing 100049 (China); Liu, Chunliang [Xi’an Jiaotong University, Xi’an 710049 (China); Wang, Yifang; Zhao, Tianchi [Institute of High Energy Physics (IHEP) of CAS, Beijing 100049 (China); Liu, Hulin; Wei, Yonglin; Sai, Xiaofeng [Graduate School of Chinese Academy of Sciences (CAS), Beijing 100049 (China); Chen, Ping [State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics (XIOPM), Chinese Academy of Sciences (CAS), Xi’an 710119 (China); Graduate School of Chinese Academy of Sciences (CAS), Beijing 100049 (China); Wang, Xing; Lu, Yu [Graduate School of Chinese Academy of Sciences (CAS), Beijing 100049 (China); Hui, Dandan; Guo, Lehui [State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics (XIOPM), Chinese Academy of Sciences (CAS), Xi’an 710119 (China); Graduate School of Chinese Academy of Sciences (CAS), Beijing 100049 (China); Liu, Shulin; Qian, Sen; Xia, Jingkai; Yan, Baojun; Zhu, Na [Institute of High Energy Physics (IHEP) of CAS, Beijing 100049 (China); Sun, Jianning; Si, Shuguang [North Night Vision Technology (NNVT) CO., LTD, Nanjing 210110 (China); and others

2016-08-11

A novel large-area (20-inch) photomultiplier tube based on microchannel plate (MCP-PMTs) is proposed for the Jiangmen Underground Neutrino Observatory (JUNO) experiment. Its photoelectron collection efficiency C{sub e} is limited by the MCP open area fraction (A{sub open}). This efficiency is studied as a function of the angular (θ), energy (E) distributions of electrons in the input charge cloud and the potential difference (U) between the PMT photocathode and the MCP input surface, considering secondary electron emission from the MCP input electrode. In CST Studio Suite, Finite Integral Technique and Monte Carlo method are combined to investigate the dependence of C{sub e} on θ, E and U. Results predict that C{sub e} can exceed A{sub open}, and are applied to optimize the structure and operational parameters of the 20-inch MCP-PMT prototype. C{sub e} of the optimized MCP-PMT is expected to reach 81.2%. Finally, the reduction of the penetration depth of the MCP input electrode layer and the deposition of a high secondary electron yield material on the MCP are proposed to further optimize C{sub e}.

Personal health records as portal to the electronic medical record.

Science.gov (United States)

Cahill, Jennifer E; Gilbert, Mark R; Armstrong, Terri S

2014-03-01

This topic review discusses the evolving clinical challenges associated with the implementation of electronic personal health records (PHR) that are fully integrated with electronic medical records (EMR). The benefits of facilitating patient access to the EMR through web-based, PHR-portals may be substantial; foremost is the potential to enhance the flow of information between patient and healthcare practitioner. The benefits of improved communication and transparency of care are presumed to be a reduction in clinical errors, increased quality of care, better patient-management of disease, and better disease and symptom comprehension. Yet PHR databases allow patients open access to newly-acquired clinical data without the benefit of concurrent expert clinical interpretation, and therefore may create the potential for greater patient distress and uncertainty. With specific attention to neuro-oncology patients, this review focuses on the developing conflicts and consequences associated with the use of a PHR that parallels data acquisition of the EMR in real-time. We conclude with a discussion of recommendations for implementing fully-integrated PHR for neuro-oncology patients.

Evaluation of set-of errors in pelvic irradiation with electronic portal imaging device

International Nuclear Information System (INIS)

Wu Xiaoying; Zhang Zhen; Wang Wenchao; Ren Jun; Guo Xiaomei; Lu Huizhong

2007-01-01

Objective: Evaluate the systematic and random set-up error in the pelvic irradiation u- sing electronic portal imaging device(EPID) to provide institution-specific margin for PTV design in pelvic cancer treatment planning with 3D conformal therapy and/or IMRT. Methods: From May to August 2005, twelve patients who received pelvic irradiation, were involved in this study. CT simulations were performed and DRRs were generated as the reference images. Ant-post and lateral portal images were taken daily, and total of 244 sets of EPID images were collected for the whole group. The translational shifts along right-left, superior-inferior and anterior-posterior directions were calculated with aligning the pelvic bony structures on the DRRs and electronic portal images. The systematic and random setup errors were evaluated based on the 244 sets of data. PTV margin was assessed assuming target rotation was negligible. Results: In the right- left (R-L), superior-inferior (S-I) and anterior-posterior (A-P) directions, the maximum shifts were 9.9, 14.0 and 21.1 mm and the systematic setup errors were 0.5, 0.2 and 2.3 mm respectively. For all 244 sets of data in this study, the frequency of the shift larger than 10 mm were 0% (R-L), 1% (S-I) and 3% (A -P); and in R-L and S-I direction, 92% and 91% of the times the shift was smaller than 5 mm. However, only 79% of the times the A-P shift was less than 5 mm. Conclusions: It is suggested in this study that in order to achieve a target coverage of better than 95% of the times throughout the pelvic irradiation in our institution, a 5 mm PTV margin in right-left and superior-inferior directions is required, however, the anterior-posterior margin needs to be increased to at least 10 mm. One needs to be cautious though when applying the PTV margin derived from small sample of patient population to individual patient. (authors)

Radioactivity Portal Monitor: An actual application and its unconventional detector

International Nuclear Information System (INIS)

Izraelevitch, F.; Matatagui, E.; Regueiro Veiga, J.L.

2012-01-01

A Radioactivity Portal Monitor is an instrument designed to be used at traffic check points to detect the presence of ionizing radiation in goods, vehicles, people, in critical places such as those at border road crossing, airports and seaports, the entrance at nuclear facilities etc. and alert the officer to the presence of radioactive and nuclear material. We have developed and built, and is in operation a Radioactivity Portal Monitor for gamma radiation. The detector and the associated electronics does not follow a conventional design concept and is based on a pressurized ionization chamber with a very large sensitive volume (60 liters) and a very large length (2 meters), and a very low level DC electronics (fAmp). The System is simple, and its operational characteristics are excellent. The reference radiation level is the background radiation, which is continuously measured, and compared with the radiation level measured when a subject (vehicle, person, good) goes trough the Monitor. The system automatically takes a decision, and alert the officer with an alarm signal if the detected radiation level is larger than the reference (dynamical) level. We will describe the designed system and some of its characterization results will be shown (author)

Analysis and modeling of electronic portal imaging exit dose measurements

International Nuclear Information System (INIS)

Pistorius, S.; Yeboah, C.

1995-01-01

In spite of the technical advances in treatment planning and delivery in recent years, it is still unclear whether the recommended accuracy in dose delivery is being achieved. Electronic portal imaging devices, now in routine use in many centres, have the potential for quantitative dosimetry. As part of a project which aims to develop an expert-system based On-line Dosimetric Verification (ODV) system we have investigated and modelled the dose deposited in the detector of a video based portal imaging system. Monte Carlo techniques were used to simulate gamma and x-ray beams in homogeneous slab phantom geometries. Exit doses and energy spectra were scored as a function of (i) slab thickness, (ii) field size and (iii) the air gap between the exit surface and the detector. The results confirm that in order to accurately calculate the dose in the high atomic number Gd 2 O 2 S detector for a range of air gaps, field sizes and slab thicknesses both the magnitude of the primary and scattered components and their effective energy need to be considered. An analytic, convolution based model which attempts to do this is proposed. The results of the simulation and the ability of the model to represent these data will be presented and discussed. This model is used to show that, after training, a back-propagation feed-forward cascade correlation neural network has the ability to identify and recognise the cause of, significant dosimetric errors

SIFT: A method to verify the IMRT fluence delivered during patient treatment using an electronic portal imaging device

International Nuclear Information System (INIS)

Vieira, Sandra C.; Dirkx, Maarten L.P.; Heijmen, Ben J.M.; Boer, Hans C.J. de

2004-01-01

Purpose: Radiotherapy patients are increasingly treated with intensity-modulated radiotherapy (IMRT) and high tumor doses. As part of our quality control program to ensure accurate dose delivery, a new method was investigated that enables the verification of the IMRT fluence delivered during patient treatment using an electronic portal imaging device (EPID), irrespective of changes in patient geometry. Methods and materials: Each IMRT treatment field is split into a static field and a modulated field, which are delivered in sequence. Images are acquired for both fields using an EPID. The portal dose image obtained for the static field is used to determine changes in patient geometry between the planning CT scan and the time of treatment delivery. With knowledge of these changes, the delivered IMRT fluence can be verified using the portal dose image of the modulated field. This method, called split IMRT field technique (SIFT), was validated first for several phantom geometries, followed by clinical implementation for a number of patients treated with IMRT. Results: The split IMRT field technique allows for an accurate verification of the delivered IMRT fluence (generally within 1% [standard deviation]), even if large interfraction changes in patient geometry occur. For interfraction radiological path length changes of 10 cm, deliberately introduced errors in the delivered fluence could still be detected to within 1% accuracy. Application of SIFT requires only a minor increase in treatment time relative to the standard IMRT delivery. Conclusions: A new technique to verify the delivered IMRT fluence from EPID images, which is independent of changes in the patient geometry, has been developed. SIFT has been clinically implemented for daily verification of IMRT treatment delivery

The weight and angle of depression detection and control system of a large portal crane

Science.gov (United States)

Shi, Lian-Wen; Xie, Hongxia; Wang, Meijing; Guan, Yankui; Leng, Gengxin

2008-12-01

In order to prevent overturning accidents, the lifted weight and the angle of depression should be detected when a large portal crane is working in a shipyard. However, the locations of the weight sensor and the angle of depression detection part are far away from the central control room. The long signal transmitting distance is so long that it results in a lot of interferences, even the breaking down of the system. In order to solve the above mentioned problems, a high precision analog signal amplifier and a voltage / current (V / I) transforming circuit is set at the place of the sensor to detect the weight. After the sensor signals have been amplified, they will be transformed into 4 to 20 mA current signals for transmission. Thus the interferences in the long transmitting process can be overcome. A WXJ-3 potentiometer is applied to detect the angle of depression. This device has the advantages of a high accuracy of repeated positions, a good stability and a strong anti-fatigue property. After processed by the current-strengthened circuit, the transmitted signals representing voltage value can have the characteristics of transmitting currents because of the large current value. Then the anti-jamming capability is stronger. Send the weight and the angle of depression detection signals to A/D converter, then the signals turn into digital representation and are sent to the control system composed of a PLC. The PLC calculates the current rated lifting weight depending on the different angles of depression, and when the weight is greater than the rated one, the PLC sends control signals to stop the lifting; hence the crane can only put down the weights. So the safety of the large portal crane is effectively guaranteed. At present ,the system has been applied to the 70-ton large portal cranes of the Tianjin Xingang Shipyard with a safe operation of 10 years.

Índice de congestão portal e a ocorrência de trombose portal pós-dape Portal congestion and thrombosis after EDS

Directory of Open Access Journals (Sweden)

Fabio Gonçalves Ferreira

2005-08-01

portal vein were analyzed: diameter, area, mean blood flow velocity and blood flow, whereupon the congestion index was calculated. RESULTS: The diameter, area and blood flow of the portal vein were greater in group B (mean of 1.52 cm; 1.77 cm² and 2533.12 ml / min than in group A (mean of 1.33 cm; 1.44 cm² and 1609.03 ml / min with p = 0.03; 0.03 and 0.04 respectively. Difference of the congestion index was not statistically significant between the two groups (p = 0.07. CONCLUSIONS: The portal vein congestion index at the preoperative of EDS estimated by Doppler ultrasound was not predictive of portal vein thrombosis in the postoperative of patients with portal hypertension due to schistosomiasis.

The use of gold markers and electronic portal imaging for radiotherapy verification in prostate cancer patients: Sweden Ghana Medical Centre experience

Directory of Open Access Journals (Sweden)

George Felix Acquah

2014-02-01

Full Text Available The success of radiotherapy cancer treatment delivery depends on the accuracy of patient setup for each fraction. A significant problem arises from reproducing the same patient position and prostate location during treatment planning for every fraction of the treatment process. To analyze the daily movements of the prostate, gold markers are implanted in the prostate and portal images taken and manually matched with reference images to locate the prostate. Geometrical and fiducial markers are annotated onto a highly quality generated digitally reconstructed radiographs, that are compared with portal images acquired right before treatment dose delivery. A 0 and 270 degree treatment fields are used to calculate prostate shifts for all prostate cancer patients undergoing treatment at the Sweden Ghana Medical Centre, using an iViewGT portal imaging device. After aligning of the marker positions onto the reference images, the set-up deviations corrections are displayed and an on-line correction procedure applied. The measured migrations of the prostate markers are below the threshold of 3 mm for the main plans and 2 mm for the boost plans. With daily electronic portal imaging combined with gold markers, provides an objective method for verifying and correcting the position of the prostate immediately prior to radiation delivery.--------------------------------------------Cite this article as: Acquah GF. The use of gold markers and electronic portal imaging for radiotherapy verification in prostate cancer patients: Sweden Ghana Medical Centre experience. Int J Cancer Ther Oncol 2014; 2(1:020112.DOI: http://dx.doi.org/10.14319/ijcto.0201.12

Burgers vector analysis of large area misfit dislocation arrays from bend contour contrast in transmission electron microscope images

CERN Document Server

Spiecker, E

2002-01-01

A transmission electron microscopy method is described which allows us to determine the Burgers vectors (BVs) of a large number of interfacial misfit dislocations (MDs) in mismatched heterostructures. The method combines large-area plan-view thinning of the sample for creating a strongly bent electron transparent foil with the analysis of the splitting and displacement of bend contours at their crossings with the MDs. The BV analysis is demonstrated for 60 deg. MDs in a low-mismatched SiGe/Si(001) heterostructure. Crossings of various bend contours with the MDs are analysed with respect to their information content for the BV analysis. In future applications the method may be used for analysing such a large number of MDs that a quantitative comparison with x-ray diffraction experiments, especially with data on diffusely scattered x-rays originating from the strain fields around the dislocations, becomes possible.

Verifying 4D gated radiotherapy using time-integrated electronic portal imaging: a phantom and clinical study

Directory of Open Access Journals (Sweden)

Slotman Ben J

2007-08-01

Full Text Available Abstract Background Respiration-gated radiotherapy (RGRT can decrease treatment toxicity by allowing for smaller treatment volumes for mobile tumors. RGRT is commonly performed using external surrogates of tumor motion. We describe the use of time-integrated electronic portal imaging (TI-EPI to verify the position of internal structures during RGRT delivery Methods TI-EPI portals were generated by continuously collecting exit dose data (aSi500 EPID, Portal vision, Varian Medical Systems when a respiratory motion phantom was irradiated during expiration, inspiration and free breathing phases. RGRT was delivered using the Varian RPM system, and grey value profile plots over a fixed trajectory were used to study object positions. Time-related positional information was derived by subtracting grey values from TI-EPI portals sharing the pixel matrix. TI-EPI portals were also collected in 2 patients undergoing RPM-triggered RGRT for a lung and hepatic tumor (with fiducial markers, and corresponding planning 4-dimensional CT (4DCT scans were analyzed for motion amplitude. Results Integral grey values of phantom TI-EPI portals correlated well with mean object position in all respiratory phases. Cranio-caudal motion of internal structures ranged from 17.5–20.0 mm on planning 4DCT scans. TI-EPI of bronchial images reproduced with a mean value of 5.3 mm (1 SD 3.0 mm located cranial to planned position. Mean hepatic fiducial markers reproduced with 3.2 mm (SD 2.2 mm caudal to planned position. After bony alignment to exclude set-up errors, mean displacement in the two structures was 2.8 mm and 1.4 mm, respectively, and corresponding reproducibility in anatomy improved to 1.6 mm (1 SD. Conclusion TI-EPI appears to be a promising method for verifying delivery of RGRT. The RPM system was a good indirect surrogate of internal anatomy, but use of TI-EPI allowed for a direct link between anatomy and breathing patterns.

Manufacture of axially insulated large-area diodes

International Nuclear Information System (INIS)

Ma Weiyi; Zhou Kungang; Wang Youtian; Zhang Dong; Shan Yusheng; Wang Naiyan

1999-01-01

The author describes the design and construction of the axially insulated large-area diodes used in the 'Heaven-1'. The four axially insulated large-area diodes are connected to the 10 ohm pulse transmission lines via the vacuum feed through tubes. The experimental results with the diodes are given. The diodes can steadily work at the voltage of 650 kV, and the diode current density is about 80 A per cm 2 with a pulse width of 220 ns. The electron beams with a total energy of 25 kJ are obtained

Preliminary Study of Position-Sensitive Large-Area Radiation Portal Monitor

Energy Technology Data Exchange (ETDEWEB)

Lim, Chang Hwy; Kim, Hyunok; Moon, Myung Kook [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Jongyul [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Park, Jong Won; Lim, Yong Kon [Korea Institute of Ocean Science and Technology, Daejeon (Korea, Republic of)

2013-10-15

An RPM, which is a passive inspection method, is a system for monitoring the movement of radioactive materials at an airport, seaport, border, etc. To detect a γ-ray, an RPM using the plastic scintillator is generally used. The method of γ-ray detection using an RPM with a plastic scintillator is to measure lights generated by an incident γ-ray in the scintillator. Generally, a large-area RPM uses one or two photomultiplier tubes (PMT) for light collection. However, in this study, we developed a 4-ch RPM that can measure the radiation signal using 4 PMTs. The reason for using 4 PMTs is to calculate the position of the radiation source. In addition, we developed an electric device for acquisition of a 4-ch output signal at the same time. To estimate the performance of the developed RPM, we performed an RPM test using a {sup 60}Co γ-ray check source. In this study, we performed the development of a 4-ch RPM. The major function of the typical RPM is to measure the radiation. However, we developed a position-sensitive 4-ch RPM, which can be used to measure the location of the radiation source, as well as the radiation measurement, at the same time. In the future, we plan to develop an algorithm for a position detection of the radiation. In addition, an algorithm will be applied to an RPM.

Large-area perovskite nanowire arrays fabricated by large-scale roll-to-roll micro-gravure printing and doctor blading

Science.gov (United States)

Hu, Qiao; Wu, Han; Sun, Jia; Yan, Donghang; Gao, Yongli; Yang, Junliang

2016-02-01

Organic-inorganic hybrid halide perovskite nanowires (PNWs) show great potential applications in electronic and optoelectronic devices such as solar cells, field-effect transistors and photodetectors. It is very meaningful to fabricate ordered, large-area PNW arrays and greatly accelerate their applications and commercialization in electronic and optoelectronic devices. Herein, highly oriented and ultra-long methylammonium lead iodide (CH3NH3PbI3) PNW array thin films were fabricated by large-scale roll-to-roll (R2R) micro-gravure printing and doctor blading in ambient environments (humility ~45%, temperature ~28 °C), which produced PNW lengths as long as 15 mm. Furthermore, photodetectors based on these PNWs were successfully fabricated on both silicon oxide (SiO2) and flexible polyethylene terephthalate (PET) substrates and showed moderate performance. This study provides low-cost, large-scale techniques to fabricate large-area PNW arrays with great potential applications in flexible electronic and optoelectronic devices.Organic-inorganic hybrid halide perovskite nanowires (PNWs) show great potential applications in electronic and optoelectronic devices such as solar cells, field-effect transistors and photodetectors. It is very meaningful to fabricate ordered, large-area PNW arrays and greatly accelerate their applications and commercialization in electronic and optoelectronic devices. Herein, highly oriented and ultra-long methylammonium lead iodide (CH3NH3PbI3) PNW array thin films were fabricated by large-scale roll-to-roll (R2R) micro-gravure printing and doctor blading in ambient environments (humility ~45%, temperature ~28 °C), which produced PNW lengths as long as 15 mm. Furthermore, photodetectors based on these PNWs were successfully fabricated on both silicon oxide (SiO2) and flexible polyethylene terephthalate (PET) substrates and showed moderate performance. This study provides low-cost, large-scale techniques to fabricate large-area PNW arrays

Effects of respiration on target and critical structure positions during treatment assessed with movie-loop electronic portal imaging

International Nuclear Information System (INIS)

Herman, Michael G.; Khadivi, Kevin O.; Kleinberg, Lawrence; Gage, Irene; Abrams, Ross A.

1997-01-01

Purpose: To determine the extent of organ and target motion due to patient respiration during chest radiotherapy using electronic portal imaging, to examine these effects on treatment volumes and to show that simulation and treatment port films do not reflect this range of motion. Materials and Methods: Twenty four patients consisting of 17 tangential breast and 7 AP-PA lung field arrangements were imaged during daily radiation treatment. Eight to 10 sequential movie-loop images were acquired during each field of each fraction with a liquid ion chamber electronic portal imaging device (EPID). Motion relative to the reference image was assessed orthogonally to the central axis of the beam. In tangential breast images, cranial, caudad and lateral lung-chest wall landmarks were used; for AP-PA lung, visible tumor, mediastinum and bronchus. Inter and intra-fractional landmark displacements were determined through off-line analysis. Intra-fractional displacements, determined from multiple images within one fraction, indicate motion of the landmark during treatment. Inter-fractional data represents motion between treatment fractions as seen in routine portal film imaging. The effects on treatment volumes were assessed for the largest displacements using the EPID data together with CT reconstruction. Results: The mean, maximum and standard deviation (σ) for observed respiration induced displacements in the cranio-caudad (CC) and lateral directions relative to the beam are summarized both within (intra) and between (inter) fractions: These data indicate that while the mean displacements are small, the standard deviations are significant and the maximum motion observed during a fraction due to respiration may exceed 3 cm in certain cases. In addition, the intra-fractional displacements significantly exceed the inter-fractional displacements, which suggests that anatomical motion is not fully quantified in routine portal imaging. In lung treatments where the largest

Investigation of electronic quality of electrodeposited cadmium sulphide layers from thiourea precursor for use in large area electronics

Energy Technology Data Exchange (ETDEWEB)

Ojo, A.A., E-mail: chartell2006@yahoo.com; Dharmadasa, I.M.

2016-09-01

CdS layers used in thin film solar cells and other electronic devices are usually grown by wet chemical methods using CdCl{sub 2} as the Cadmium source and either Na{sub 2}S{sub 2}O{sub 3}, NH{sub 4}S{sub 2}O{sub 3} or NH{sub 2}CSNH{sub 2} as Sulphur sources. Obviously, one of the sulphur precursors should produce more suitable CdS layers required to give the highest performing devices. This can only be achieved by comprehensive experimental work on growth and characterisation of CdS layers from the above mentioned sulphur sources. This paper presents the results observed on CdS layers grown by electrodepositing using two electrode configuration and thiourea as the sulphur precursor. X-ray diffraction (XRD), Raman spectroscopy, optical absorption, scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX) and photoelectrochemical (PEC) cell methods have been used to characterise the material properties. In order to test and study the electronic device quality of the layers, ohmic and rectifying contacts were fabricated on the electroplated layers. Schottky barriers, formed on the layers were also compared with previously reported work on Chemical Bath Deposited CBD-CdS layers and bulk single crystals of CdS. Comparatively, Schottky diodes fabricated on electroplated CdS layers using two-electrode system and thiourea precursor exhibit excellent electronic properties suitable for electronic devices such as thin film solar panels and large area display devices. - Highlights: • Precipitate-free electrodeposition of CdS is achievable using Thiourea precursor. • Electrodeposition of CdS using 2-electrode configuration. • The electrodeposited CdS shows excellent electronic properties. • Exploration of the effect of heat treatment temperature and heat treatment duration.

A novel canine model of portal vein stenosis plus thioacetamide administration-induced cirrhotic portal hypertension with hypersplenism.

Science.gov (United States)

Lin, Dexin; Wu, Xianbin; Ji, Xiaoke; Zhang, Qiyu; Lin, YuanWei; Chen, WeiJian; Jin, Wangxun; Deng, Liming; Chen, Yunzhi; Chen, Bicheng; Li, Jianmin

2012-01-01

Current large animal models that could closely resemble the typical features of cirrhotic portal hypertension in human have not been well established. Thus, we aimed to develop and describe a reliable and reproducible canine cirrhosis model of portal hypertension. A total of 30 mongrel dogs were randomly divided into four groups: 1 (control; n = 5), 2 (portal vein stenosis [PVS]; n = 5], 3 (thioacetamide [TAA]; n = 5), and 4 (PVS plus TAA; n = 15). After 4-months modeling period, liver and spleen CT perfusion, abdominal CT scans, portal hemodynamics, gastroscopy, hepatic function, blood routine, the bone marrow, liver, and spleen histology were studied. The animals in group 2 (PVS) developed extrahepatic portosystemic collateral circulation, particularly esophageal varices, without hepatic cirrhosis and portal hypertension. Animals from group 3 (TAA) presented mild cirrhosis and portal hypertension without significant symptoms of esophageal varices and hypersplenism. In contrast, animals from group 4 (PVS + TAA) showed well-developed micronodular and macronodular cirrhosis, associated with significant portal hypertension and hypersplenism. The combination of PVS and TAA represents a novel, reliable, and reproducible canine cirrhosis model of portal hypertension, which is associated with the typical characteristics of portal hypertension, including hypersplenism.

Search for hidden high-Z materials inside containers with the Muon Portal Project

International Nuclear Information System (INIS)

Rocca, P La; Bandieramonte, M; Blancato, A A; Bonanno, D; Indelicato, V; Presti, D Lo; Petta, C; Antonuccio, V; Becciani, U; Belluso, M; Billotta, S; Bonanno, G; Costa, A; Garozzo, S; Massimino, P; Belluomo, F; Fallica, G; Leonora, E; Longhitano, F; Longo, S

2014-01-01

The Muon Portal is a recently born project that plans to build a large area muon detector for a noninvasive inspection of shipping containers in the ports, searching for the presence of potential fissile (U, Pu) threats. The technique employed by the project is the well-known muon tomography, based on cosmic muon scattering from high-Z materials. The design and operational parameters of the muon portal under construction will be described in this paper, together with preliminary simulation and test results

Search for hidden high-Z materials inside containers with the Muon Portal Project

Science.gov (United States)

La Rocca, P.; Antonuccio, V.; Bandieramonte, M.; Becciani, U.; Belluomo, F.; Belluso, M.; Billotta, S.; Blancato, A. A.; Bonanno, D.; Bonanno, G.; Costa, A.; Fallica, G.; Garozzo, S.; Indelicato, V.; Leonora, E.; Longhitano, F.; Longo, S.; Lo Presti, D.; Massimino, P.; Petta, C.; Pistagna, C.; Pugliatti, C.; Puglisi, M.; Randazzo, N.; Riggi, F.; Riggi, S.; Romeo, G.; Russo, G. V.; Santagati, G.; Valvo, G.; Vitello, F.; Zaia, A.; Zappalà, G.

2014-01-01

The Muon Portal is a recently born project that plans to build a large area muon detector for a noninvasive inspection of shipping containers in the ports, searching for the presence of potential fissile (U, Pu) threats. The technique employed by the project is the well-known muon tomography, based on cosmic muon scattering from high-Z materials. The design and operational parameters of the muon portal under construction will be described in this paper, together with preliminary simulation and test results.

CT of portal vein tumor thrombosis. Usefulness of dynamic CT

Energy Technology Data Exchange (ETDEWEB)

Takemoto, Kazumasa; Inoue, Yuichi; Tanaka, Masahiro; Nemoto, Yutaka; Nakamura, Kenji [Osaka City Univ. (Japan). Faculty of Medicine

1983-08-01

We evaluated CT findings of portal vein tumor thrombosis in 16 hepatomas by plain, contrast and dynamic CT. Plain and contrast CT findings were an enlargement of the portal vein (81%), intraluminal low density area (63%). Dynamic CT enhanced the diagnostic capability of the tumor thrombus as a relatively low density area because of the marked enhancement of the portal vein. In addition, dynamic CT newly demonstrated hyperdense peripheral ring (35%) and arterio portal shunt (35%). It is advisable to select the scan level to include the portal vein when dynamic CT is performed in the patient of hepatocellular carcinoma.

Radioisotopic evaluation of portal circulation

International Nuclear Information System (INIS)

Maliska, C.; Rosenthal, D.

1986-01-01

The use of a radio-tracer of portal circulation through the intestine, should prevent cruel punctures in the portal-vein or spleen as it is usually the case with traditional methods in the study of portal-system. The absorption of I-131 and Tc-99m, previously cheked in rabbits presented similar results in dogs. The time of circulation between terminal large-intestine and the liver (t-RF) was determined by external counting at hepatic level by recording radioactivity variation-time. In healthy animals the t-RF was from 20to 60 seconds, with average time of 42 seconds. In 2 animals with partial binding of portal-vein the t-RF went up to 110 and 120 seconds. (Author) [pt

Validation of quality control tests of a multi leaf collimator using electronic portal image devices and commercial software; Validacion de unas pruebas de control de calidad del colimador multilamina utilizando dispositivos electronicos de imagen portal y una aplicacion comercial

Energy Technology Data Exchange (ETDEWEB)

Latorre-Musoll, A.; Jornet Sala, N.; Carrasco de Fez, P.; Edualdo Puell, T.; Ruiz Martinez, A.; Ribas Morales, M.

2013-07-01

We describe a daily quality control procedure of the multi leaf collimator (MLC) based on electronic portal image devices and commercial software. We designed tests that compare portal images of a set of static and dynamic MLC configurations to a set of reference images using commercial portal dosimetry software. Reference images were acquired using the same set of MLC configurations after the calibration of the MLC. To assess the sensitivity to detect MLC under performances, we modified the MLC configurations by inserting a range of leaf position and speed errors. Distance measurements on portal images correlated with leaf position errors down to 0.1 mm in static MLC configurations. Dose differences between portal images correlated both with speed errors down to 0.5% of the nominal leaf velocities and with leaf position errors down to 0.1 mm in dynamic MLC configurations. The proposed quality control procedure can assess static and dynamic MLC configurations with high sensitivity and reliability. (Author)

Generation of low KV x-ray portal images with mega-voltage electron beams

International Nuclear Information System (INIS)

Kenny, J.; Ebert, M.

2004-01-01

Full text: The increasing complexity of radiation therapy plans and reduced target margins, have made accurate localization of patients at treatment a crucial quality assurance issue. Mega-voltage portal images, the standard for treatment localization, are inherently low in contrast because x-ray attenuation at these energies is similar for most body tissues. Thus anatomical features are difficult to distinguish and match to features on a reference diagnostic image. This project investigates the possibly of using x-rays created by an external target placed in the path of a clinical mega-voltage electron beam. This target is optimised to produce a higher proportion of useful imaging x-rays in the range of 50-200kV. It is thought that a high efficiency Varian aSi500 amorphous silicon EPID will be sufficient to compensate for the very low efficiency of x-ray production. The project was undertaken with concurrent theoretical and experimental components. The former involved Monte Carlo models of low Z target design while in the later, experimental data was gathered to validate the model and explore the practical issues associated with electron mode image acquisition. A 6 MeV electron beam model for a Varian Clinac 21EX was developed with EGS4/BEAMnrc User Code and compared to measured beam data. Phase space data scored at the secondary collimator then became the input for simulations of a target placed in the accessory tray. Target materials were predominately low atomic number (Z) because a) production of high energy x-rays is minimized and, b) fewer low energy x-rays produced will be absorbed within the target. Photon and electron energy spectrums of the modified beam were evaluated for a range of target geometries. Ultimately, several materials were used in combination to optimise an x-ray yield for energies <200kV while removing electrons and very low energy x-rays, that contribute to patient dose but not to image formation. Low energy images of a PIPs EPID QA

ASH External Web Portal (External Portal) -

Data.gov (United States)

Department of Transportation — The ASH External Web Portal is a web-based portal that provides single sign-on functionality, making the web portal a single location from which to be authenticated...

Portal venous stent placement for treatment of portal hypertension caused by benign main portal vein stenosis.

Science.gov (United States)

Shan, Hong; Xiao, Xiang-Sheng; Huang, Ming-Sheng; Ouyang, Qiang; Jiang, Zai-Bo

2005-06-07

To evaluate the value of endovascular stent in the treatment of portal hypertension caused by benign main portal vein stenosis. Portal vein stents were implanted in six patients with benign main portal vein stenosis (inflammatory stenosis in three cases, postprocedure of liver transplantation in another three cases). Changes in portal vein pressure, portal vein patency, relative clinical symptoms, complications, and survival were evaluated. Six metallic stents were successfully placed across the portal vein stenotic or obstructive lesions in six patients. Mean portal venous pressure decreased significantly after stent implantation from (37.3+/-4.7) cm H(2)O to (18.0+/-1.9) cm H(2)O. The portal blood flow restored and the symptoms caused by portal hypertension were eliminated. There were no severe procedure-related complications. The patients were followed up for 1-48 mo. The portal vein remained patent during follow-up. All patients survived except for one patient who died of other complications of liver transplantation. Percutaneous portal vein stent placement for the treatment of portal hypertension caused by benign main portal vein stenosis is safe and effective.

Dosimetric verification of radiation therapy including intensity modulated treatments, using an amorphous-silicon electronic portal imaging device

Science.gov (United States)

Chytyk-Praznik, Krista Joy

Radiation therapy is continuously increasing in complexity due to technological innovation in delivery techniques, necessitating thorough dosimetric verification. Comparing accurately predicted portal dose images to measured images obtained during patient treatment can determine if a particular treatment was delivered correctly. The goal of this thesis was to create a method to predict portal dose images that was versatile and accurate enough to use in a clinical setting. All measured images in this work were obtained with an amorphous silicon electronic portal imaging device (a-Si EPID), but the technique is applicable to any planar imager. A detailed, physics-motivated fluence model was developed to characterize fluence exiting the linear accelerator head. The model was further refined using results from Monte Carlo simulations and schematics of the linear accelerator. The fluence incident on the EPID was converted to a portal dose image through a superposition of Monte Carlo-generated, monoenergetic dose kernels specific to the a-Si EPID. Predictions of clinical IMRT fields with no patient present agreed with measured portal dose images within 3% and 3 mm. The dose kernels were applied ignoring the geometrically divergent nature of incident fluence on the EPID. A computational investigation into this parallel dose kernel assumption determined its validity under clinically relevant situations. Introducing a patient or phantom into the beam required the portal image prediction algorithm to account for patient scatter and attenuation. Primary fluence was calculated by attenuating raylines cast through the patient CT dataset, while scatter fluence was determined through the superposition of pre-calculated scatter fluence kernels. Total dose in the EPID was calculated by convolving the total predicted incident fluence with the EPID-specific dose kernels. The algorithm was tested on water slabs with square fields, agreeing with measurement within 3% and 3 mm. The

MASCP Gator: An overview of the Arabidopsis proteomic aggregation portal

Directory of Open Access Journals (Sweden)

Gregory W Mann

2013-10-01

Full Text Available A key challenge in the area of bioinformatics in the coming decades is the ability to manage the wealth of information that is being generated from the variety of high throughput methodologies currently being undertaken in laboratories across the world. While these approaches have made available large volumes of data to the research community, less attention has been given to the problem of how to intuitively present the data to enable greater biological insights. Recently, an attempt was made to tackle this problem in the area of Arabidopsis proteomics. The model plant has been the target of countless proteomics surveys producing an exhaustive array of data and online repositories. The MASCP Gator is an aggregation portal for proteomic data currently being produced by the community and unites a large collection of specialized resources to a single portal (http://gator.masc-proteomics.org/. Here we describe the latest additions, upgrades and features to this resource further expanding its role into protein modifications and genome sequence variations.

Large-area smart glass and integrated photovoltaics

Energy Technology Data Exchange (ETDEWEB)

Lampert, C.M. [Star Science, 8730 Water Road, Cotati, CA 94931-4252 (United States)

2003-04-01

Several companies throughout the world are developing dynamic glazing and large-area flat panel displays. University and National Laboratory groups are researching new materials and processes to improve these products. The concept of a switchable glazing for building and vehicle application is very attractive. Conventional glazing only offers fixed transmittance and control of energy passing through it. Given the wide range of illumination conditions and glare, a dynamic glazing with adjustable transmittance offers the best solution. Photovoltaics can be integrated as power sources for smart windows. In this way a switchable window could be a completely stand alone smart system. A new range of large-area flat panel display including light-weight and flexible displays are being developed. These displays can be used for banner advertising, dynamic pricing in stores, electronic paper, and electronic books, to name only a few applications. This study covers selected switching technologies including electrochromism, suspended particles, and encapsulated liquid crystals.

NOTE: A method for controlling image acquisition in electronic portal imaging devices

Science.gov (United States)

Glendinning, A. G.; Hunt, S. G.; Bonnett, D. E.

2001-02-01

Certain types of camera-based electronic portal imaging devices (EPIDs) which initiate image acquisition based on sensing a change in video level have been observed to trigger unreliably at the beginning of dynamic multileaf collimation sequences. A simple, novel means of controlling image acquisition with an Elekta linear accelerator (Elekta Oncology Systems, Crawley, UK) is proposed which is based on illumination of a photodetector (ORP-12, Silonex Inc., Plattsburgh, NY, USA) by the electron gun of the accelerator. By incorporating a simple trigger circuit it is possible to derive a beam on/off status signal which changes at least 100 ms before any dose is measured by the accelerator. The status signal does not return to the beam-off state until all dose has been delivered and is suitable for accelerator pulse repetition frequencies of 50-400 Hz. The status signal is thus a reliable means of indicating the initiation and termination of radiation exposure, and thus controlling image acquisition of such EPIDs for this application.

Benchmark test cases for evaluation of computer-based methods for detection of setup errors: realistic digitally reconstructed electronic portal images with known setup errors

International Nuclear Information System (INIS)

Fritsch, Daniel S.; Raghavan, Suraj; Boxwala, Aziz; Earnhart, Jon; Tracton, Gregg; Cullip, Timothy; Chaney, Edward L.

1997-01-01

Purpose: The purpose of this investigation was to develop methods and software for computing realistic digitally reconstructed electronic portal images with known setup errors for use as benchmark test cases for evaluation and intercomparison of computer-based methods for image matching and detecting setup errors in electronic portal images. Methods and Materials: An existing software tool for computing digitally reconstructed radiographs was modified to compute simulated megavoltage images. An interface was added to allow the user to specify which setup parameter(s) will contain computer-induced random and systematic errors in a reference beam created during virtual simulation. Other software features include options for adding random and structured noise, Gaussian blurring to simulate geometric unsharpness, histogram matching with a 'typical' electronic portal image, specifying individual preferences for the appearance of the 'gold standard' image, and specifying the number of images generated. The visible male computed tomography data set from the National Library of Medicine was used as the planning image. Results: Digitally reconstructed electronic portal images with known setup errors have been generated and used to evaluate our methods for automatic image matching and error detection. Any number of different sets of test cases can be generated to investigate setup errors involving selected setup parameters and anatomic volumes. This approach has proved to be invaluable for determination of error detection sensitivity under ideal (rigid body) conditions and for guiding further development of image matching and error detection methods. Example images have been successfully exported for similar use at other sites. Conclusions: Because absolute truth is known, digitally reconstructed electronic portal images with known setup errors are well suited for evaluation of computer-aided image matching and error detection methods. High-quality planning images, such as

Digitalization and networking of analog simulators and portal images.

Science.gov (United States)

Pesznyák, Csilla; Zaránd, Pál; Mayer, Arpád

2007-03-01

Many departments have analog simulators and irradiation facilities (especially cobalt units) without electronic portal imaging. Import of the images into the R&V (Record & Verify) system is required. Simulator images are grabbed while portal films scanned by using a laser scanner and both converted into DICOM RT (Digital Imaging and Communications in Medicine Radiotherapy) images. Image intensifier output of a simulator and portal films are converted to DICOM RT images and used in clinical practice. The simulator software was developed in cooperation at the authors' hospital. The digitalization of analog simulators is a valuable updating in clinical use replacing screen-film technique. Film scanning and digitalization permit the electronic archiving of films. Conversion into DICOM RT images is a precondition of importing to the R&V system.

The BioMart community portal: an innovative alternative to large, centralized data repositories

Science.gov (United States)

The BioMart Community Portal (www.biomart.org) is a community-driven effort to provide a unified interface to biomedical databases that are distributed worldwide. The portal provides access to numerous database projects supported by 30 scientific organizations. It includes over 800 different biologi...

Mapping the electrical properties of large-area graphene

DEFF Research Database (Denmark)

Bøggild, Peter; Mackenzie, David; Whelan, Patrick Rebsdorf

2017-01-01

The significant progress in terms of fabricating large-area graphene films for transparent electrodes, barriers, electronics, telecommunication and other applications has not yet been accompanied by efficient methods for characterizing the electrical properties of large-area graphene. While......, and a high measurement effort per device. In this topical review, we provide a comprehensive overview of the issues that need to be addressed by any large-area characterisation method for electrical key performance indicators, with emphasis on electrical uniformity and on how this can be used to provide...... a more accurate analysis of the graphene film. We review and compare three different, but complementary approaches that rely either on fixed contacts (dry laser lithography), movable contacts (micro four point probes) and non-contact (terahertz time-domain spectroscopy) between the probe and the graphene...

Giant cavernous hemangioma coexistent with diffuse hepatic hemangiomatosis presenting as portal vein thrombosis and hepatic lobar atrophy

Directory of Open Access Journals (Sweden)

Bo Reum Yoo

2014-01-01

Full Text Available

A combination of giant hepatic hemangioma and diffuse hemangiomatosis is extremely rare in adults. Even when they are large, hemangiomas are soft and rarely compress adjacent structures. A 78-year-old man presented with abdominal pain and distension. Ultrasonography, computed tomography, and magnetic resonance imaging demonstrated a large expansile mass replacing the medial segment and caudate lobe with diffusely scattered nodules in the entire liver. The large hilar mass contained a central nonenhancing area and had a mass effect, leading to left portal vein occlusion. The image findings also revealed two unprecedented findings: left lateral segmental atrophy of the liver and recent portomesenteric vein thrombosis. The hepatic lesions were confirmed with hemangiomas by ultrasonography-guided biopsy. We diagnosed intrahepatic portal vein obstruction caused by a mass effect of giant hepatic hemangioma coexistent with diffuse hemangiomatosis, resulting in hepatic segmental atrophy and extrahepatic portal vein thrombosis.

Giant cavernous hemangioma coexistent with diffuse hepatic hemangiomatosis presenting as portal vein thrombosis and hepatic lobar atrophy

Energy Technology Data Exchange (ETDEWEB)

Yoo, Bo Reum; Han, Hyun Young; Choi, So Young; Kim, Joo Heun [Eulji University Hospital, Daejeon(Korea, Republic of)

2014-03-15

A combination of giant hepatic hemangioma and diffuse hemangiomatosis is extremely rare in adults. Even when they are large, hemangiomas are soft and rarely compress adjacent structures. A 78-year-old man presented with abdominal pain and distension. Ultrasonography, computed tomography, and magnetic resonance imaging demonstrated a large expansile mass replacing the medial segment and caudate lobe with diffusely scattered nodules in the entire liver. The large hilar mass contained a central nonenhancing area and had a mass effect, leading to left portal vein occlusion. The image findings also revealed two unprecedented findings: left lateral segmental atrophy of the liver and recent portomesenteric vein thrombosis. The hepatic lesions were confirmed with hemangiomas by ultrasonography-guided biopsy. We diagnosed intrahepatic portal vein obstruction caused by a mass effect of giant hepatic hemangioma coexistent with diffuse hemangiomatosis, resulting in hepatic segmental atrophy and extrahepatic portal vein thrombosis.

Next generation non-vacuum, maskless, low temperature nanoparticle ink laser digital direct metal patterning for a large area flexible electronics.

Science.gov (United States)

Yeo, Junyeob; Hong, Sukjoon; Lee, Daehoo; Hotz, Nico; Lee, Ming-Tsang; Grigoropoulos, Costas P; Ko, Seung Hwan

2012-01-01

Flexible electronics opened a new class of future electronics. The foldable, light and durable nature of flexible electronics allows vast flexibility in applications such as display, energy devices and mobile electronics. Even though conventional electronics fabrication methods are well developed for rigid substrates, direct application or slight modification of conventional processes for flexible electronics fabrication cannot work. The future flexible electronics fabrication requires totally new low-temperature process development optimized for flexible substrate and it should be based on new material too. Here we present a simple approach to developing a flexible electronics fabrication without using conventional vacuum deposition and photolithography. We found that direct metal patterning based on laser-induced local melting of metal nanoparticle ink is a promising low-temperature alternative to vacuum deposition- and photolithography-based conventional metal patterning processes. The "digital" nature of the proposed direct metal patterning process removes the need for expensive photomask and allows easy design modification and short turnaround time. This new process can be extremely useful for current small-volume, large-variety manufacturing paradigms. Besides, simple, scalable, fast and low-temperature processes can lead to cost-effective fabrication methods on a large-area polymer substrate. The developed process was successfully applied to demonstrate high-quality Ag patterning (2.1 µΩ·cm) and high-performance flexible organic field effect transistor arrays.

Next generation non-vacuum, maskless, low temperature nanoparticle ink laser digital direct metal patterning for a large area flexible electronics.

Directory of Open Access Journals (Sweden)

Junyeob Yeo

Full Text Available Flexible electronics opened a new class of future electronics. The foldable, light and durable nature of flexible electronics allows vast flexibility in applications such as display, energy devices and mobile electronics. Even though conventional electronics fabrication methods are well developed for rigid substrates, direct application or slight modification of conventional processes for flexible electronics fabrication cannot work. The future flexible electronics fabrication requires totally new low-temperature process development optimized for flexible substrate and it should be based on new material too. Here we present a simple approach to developing a flexible electronics fabrication without using conventional vacuum deposition and photolithography. We found that direct metal patterning based on laser-induced local melting of metal nanoparticle ink is a promising low-temperature alternative to vacuum deposition- and photolithography-based conventional metal patterning processes. The "digital" nature of the proposed direct metal patterning process removes the need for expensive photomask and allows easy design modification and short turnaround time. This new process can be extremely useful for current small-volume, large-variety manufacturing paradigms. Besides, simple, scalable, fast and low-temperature processes can lead to cost-effective fabrication methods on a large-area polymer substrate. The developed process was successfully applied to demonstrate high-quality Ag patterning (2.1 µΩ·cm and high-performance flexible organic field effect transistor arrays.

Calculation of neutron die-away times in a large-vehicle portal monitor

International Nuclear Information System (INIS)

Lillie, R.A.; Santoro, R.T.; Alsmiller, R.G. Jr.

1980-05-01

Monte Carlo methods have been used to calculate neutron die-away times in a large-vehicle portal monitor. These calculations were performed to investigate the adequacy of using neutron die-away time measurements to detect the clandestine movement of shielded nuclear materials. The geometry consisted of a large tunnel lined with He 3 proportional counters. The time behavior of the (n,p) capture reaction in these counters was calculated when the tunnel contained a number of different tractor-trailer load configurations. Neutron die-away times obtained from weighted least squares fits to these data were compared. The change in neutron die-away time due to the replacement of cargo in a fully loaded truck with a spherical shell containing 240 kg of borated polyethylene was calculated to be less than 3%. This result together with the overall behavior of neutron die-away time versus mass inside the tunnel strongly suggested that measurements of this type will not provide a reliable means of detecting shielded nuclear materials in a large vehicle. 5 figures, 4 tables

Portal-venous gas unrelated to mesenteric ischemia

International Nuclear Information System (INIS)

Wiesner, Walter; Mortele, Koenraad J.; Ji, Hoon; Ros, Pablo R.; Glickman, Jonathan N.

2002-01-01

The aim of this study was to report on 8 patients with all different non-ischemic etiologies for portal-venous gas and to discuss this rare entity and its potentially misleading CT findings in context with a review of the literature. The CT examinations of eight patients who presented with intrahepatic portal-venous gas, unrelated to bowel ischemia or infarction, were reviewed and compared with their medical records with special emphasis on the pathogenesis and clinical impact of portal-venous gas caused by non-ischemic conditions. The etiologies for portal-venous gas included: abdominal trauma (n=1); large gastric cancer (n=1); prior gastroscopic biopsy (n=1); prior hemicolectomy (n=1); graft-vs-host reaction (n=1); large paracolic abscess (n=1); mesenteric recurrence of ovarian cancer superinfected with clostridium septicum (n=1); and sepsis with Pseudomonas aeruginosa (n=1). The clinical outcome of all patients was determined by their underlying disease and not negatively influenced by the presence of portal-venous gas. Although the presence of portal-venous gas usually raises the suspicion of bowel ischemia and/or intestinal necrosis, this CT finding may be related to a variety of non-ischemic etiologies and pathogeneses as well. The knowledge about these conditions may help to avoid misinterpretation of CT findings, inappropriate clinical uncertainty and unnecessary surgery in certain cases. (orig.)

Portal Vein Stenting for Portal Biliopathy with Jaundice

Energy Technology Data Exchange (ETDEWEB)

Hyun, Dongho, E-mail: mesentery@naver.com; Park, Kwang Bo, E-mail: kbjh.park@samsung.com [Sungkyunkwan University School of Medicine, Department of Radiology, Samsung Medical Center (Korea, Republic of); Lim, Seong Joo [Konyang University, Department of Radiology, College of Medicine, Konyang University Hospital (Korea, Republic of); Hwang, Jin Ho [Hallym University Sacred Heart Hospital, Department of Radiology (Korea, Republic of); Sinn, Dong Hyun [Sungkyunkwan University School of Medicine, Department of Medicine, Samsung Medical Center (Korea, Republic of)

2016-04-15

Portal biliopathy refers to obstruction of the bile duct by dilated peri- or para-ductal collateral channels following the main portal vein occlusion from various causes. Surgical shunt operation or endoscopic treatment has been reported. Herein, we report a case of portal biliopathy that was successfully treated by interventional portal vein recanalization.

The Sydney West Knowledge Portal: Evaluating the Growth of a Knowledge Portal to Support Translational Research.

Science.gov (United States)

Janssen, Anna; Robinson, Tracy Elizabeth; Provan, Pamela; Shaw, Tim

2016-06-29

The Sydney West Translational Cancer Research Centre is an organization funded to build capacity for translational research in cancer. Translational research is essential for ensuring the integration of best available evidence into practice and for improving patient outcomes. However, there is a low level of awareness regarding what it is and how to conduct it optimally. One solution to addressing this gap is the design and deployment of web-based knowledge portals to disseminate new knowledge and engage with and connect dispersed networks of researchers. A knowledge portal is an web-based platform for increasing knowledge dissemination and management in a specialized area. To measure the design and growth of an web-based knowledge portal for increasing individual awareness of translational research and to build organizational capacity for the delivery of translational research projects in cancer. An adaptive methodology was used to capture the design and growth of an web-based knowledge portal in cancer. This involved stakeholder consultations to inform initial design of the portal. Once the portal was live, site analytics were reviewed to evaluate member usage of the portal and to measure growth in membership. Knowledge portal membership grew consistently for the first 18 months after deployment, before leveling out. Analysis of site metrics revealed members were most likely to visit portal pages with community-generated content, particularly pages with a focus on translational research. This was closely followed by pages that disseminated educational material about translational research. Preliminary data from this study suggest that knowledge portals may be beneficial tools for translating new evidence and fostering an environment of communication and collaboration.

Implications of Patient Portal Transparency in Oncology: Qualitative Interview Study on the Experiences of Patients, Oncologists, and Medical Informaticists.

Science.gov (United States)

Alpert, Jordan M; Morris, Bonny B; Thomson, Maria D; Matin, Khalid; Brown, Richard F

2018-03-26

Providing patients with unrestricted access to their electronic medical records through patient portals has impacted patient-provider communication and patients' personal health knowledge. However, little is known about how patient portals are used in oncology. The aim of this study was to understand attitudes of the portal's adoption for oncology and to identify the advantages and disadvantages of using the portal to communicate and view medical information. In-depth semistructured interviews were conducted with 60 participants: 35 patients, 13 oncologists, and 12 medical informaticists. Interviews were recorded, transcribed, and thematically analyzed to identify critical incidents and general attitudes encountered by participants. Two primary themes were discovered: (1) implementation practices influence attitudes, in which the decision-making and execution process of introducing portals throughout the hospital did not include the input of oncologists. Lack of oncologists' involvement led to a lack of knowledge about portal functionality, such as not knowing the time period when test results would be disclosed to patients; (2) perceptions of portals as communication tools varies by user type, meaning that each participant group (patients, oncologists, and medical informaticists) had varied opinions about how the portal should be used to transmit and receive information. Oncologists and medical informaticists had difficulty understanding one another's culture and communication processes in their fields, while patients had preferences for how they would like to receive communication, but it largely depended upon the type of test being disclosed. The majority of patients (54%, 19/35) who participated in this study viewed lab results or scan reports via the portal before being contacted by a clinician. Most were relatively comfortable with this manner of disclosure but still preferred face-to-face or telephone communication. Findings from this study indicate that

Pathology of idiopathic non-cirrhotic portal hypertension.

Science.gov (United States)

Guido, Maria; Sarcognato, Samantha; Sacchi, Diana; Colloredo, Guido

2018-04-12

Idiopathic non-cirrhotic portal hypertension is an under-recognized vascular liver disease of unknown etiology, characterized by clinical signs of portal hypertension in the absence of cirrhosis. By definition, any disorder known to cause portal hypertension in the absence of cirrhosis and any cause of chronic liver disease must be excluded to make a diagnosis of idiopathic non-cirrhotic portal hypertension. However, the diagnosis is often difficult because the disease resembles cirrhosis and there is no gold standard test. Liver biopsy is an essential tool: it is able to exclude cirrhosis and other causes of portal hypertension and it allows the identification of the characteristic lesions. Nonetheless, the histological diagnosis of idiopathic non-cirrhotic portal hypertension is not always straightforward, in particular by needle biopsy samples, because there is no pathognomonic lesion, but rather a variety of vascular changes which are unevenly distributed, very subtle, and not all necessarily identified in a single specimen. Pathologists should be able to recognize several patterns of injury, involving portal/periportal areas as well as parenchymal structures.The histological features of idiopathic non-cirrhotic portal hypertension are described in this review, focusing on their interpretation in needle biopsy specimens.

Portal Vein Dopplerflowmetry in healthy sheep according to age

Directory of Open Access Journals (Sweden)

Alexandra F. Belotta

Full Text Available ABSTRACT: Pulsed Doppler ultrasound was used to evaluate portal blood flow, portal velocity and portal congestion index in 24 healthy sheep divided into groups (lambs, yearlings and ewes, according to age. Measurements were performed at the 11th right intercostal space using ideal insonation angle and uniform insonation method. Mean values obtained in each group were compared with one-way ANOVA, followed by Tukey post-hoc test. Portal velocity and portal blood flow were statistically similar between the groups (P>0.05. Mean portal velocity were 17.75; 17.13 and 16.75; while mean portal blood flow were 26.65; 31.04 and 24.32 for lambs, yearlings and ewes, respectively. Portal congestion index was statistically distinct between the groups and values for lambs, yearlings and ewes were 0.009; 0.058 and 0.09, respectively (P<0.01. Statistical differences were observed in portal vein diameter, portal vein area and portal congestion index between the groups, presumably due to influence of weight and not to age.

Progress on large area GEMs (VCI 2010)

CERN Document Server

Villa, Marco; Alfonsi, Matteo; Brock, Ian; Croci, Gabriele; David, Eric; de Oliveira, Rui; Ropelewski, Leszek; Taureg, Hans; van Stenis, Miranda

2011-01-01

The Gas Electron Multiplier (GEM) manufacturing technique has recently evolved to allow the production of large area GEMs. A novel approach based on single mask photolithography eliminates the mask alignment issue, which limits the dimensions in the traditional double mask process. Moreover, a splicing technique overcomes the limited width of the raw material. Stretching and handling issues in large area GEMs have also been addressed. Using the new improvements it was possible to build a prototype triple-GEM detector of ~ 2000 cm2 active area, aimed at an application for the TOTEM T1 upgrade. Further refinements of the single mask technique give great control over the shape of the GEM holes and the size of the rims, which can be tuned as needed. In this framework, simulation studies can help to understand the GEM behavior depending on the hole shape.

Portal Vein Thrombosis

Directory of Open Access Journals (Sweden)

Hakan Demirci

2016-01-01

Full Text Available Portal vein thrombosis is an important cause of presinusoidal portal hypertension. Portal vein thrombosis commonly occurs in patient with cirrhosis, malignancy and prothrombotic states. Patients with acute portal vein thrombosis have immediate onset. Patients with chronic portal vein thrombosis have developed portal hypertension and cavernous portal transformation. Portal vein thrombosis is diagnosed with doppler ultrasound, computed tomography and magnetic resonance imaging. Therapy with low molecular weight heparin achieves recanalization in more than half of acute cases.

Edge field emission of large-area single layer graphene

Energy Technology Data Exchange (ETDEWEB)

Kleshch, Victor I., E-mail: klesch@polly.phys.msu.ru [Department of Physics, M.V. Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Bandurin, Denis A. [Department of Physics, M.V. Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Orekhov, Anton S. [Department of Physics, M.V. Lomonosov Moscow State University, Moscow 119991 (Russian Federation); A.V. Shubnikov Institute of Crystallography, RAS, Moscow 119333 (Russian Federation); Purcell, Stephen T. [ILM, Université Claude Bernard Lyon 1 et CNRS, UMR 5586, 69622 Villeurbanne (France); Obraztsov, Alexander N. [Department of Physics, M.V. Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Department of Physics and Mathematics, University of Eastern Finland, Joensuu 80101 (Finland)

2015-12-01

Graphical abstract: - Highlights: • Stable field emission was observed from the edge of large-area graphene on quartz. • A strong hysteresis in current–voltage characteristics was observed. • The hysteresis was explained by mechanical peeling of graphene edge from substrate. • Reversible peeling of graphene edge may be used in microelectromechanical systems. - Abstract: Field electron emission from the edges of large-area (∼1 cm × 1 cm) graphene films deposited onto quartz wafers was studied. The graphene was previously grown by chemical vapour deposition on copper. An extreme enhancement of electrostatic field at the edge of the films with macroscopically large lateral dimensions and with single atom thickness was achieved. This resulted in the creation of a blade type electron emitter, providing stable field emission at low-voltage with linear current density up to 0.5 mA/cm. A strong hysteresis in current–voltage characteristics and a step-like increase of the emission current during voltage ramp up were observed. These effects were explained by the local mechanical peeling of the graphene edge from the quartz substrate by the ponderomotive force during the field emission process. Specific field emission phenomena exhibited in the experimental study are explained by a unique combination of structural, electronic and mechanical properties of graphene. Various potential applications ranging from linear electron beam sources to microelectromechanical systems are discussed.

Digitalization and networking of analog simulators and portal images

Energy Technology Data Exchange (ETDEWEB)

Pesznyak, C.; Zarand, P.; Mayer, A. [Uzsoki Hospital, Budapest (Hungary). Inst. of Oncoradiology

2007-03-15

Background: Many departments have analog simulators and irradiation facilities (especially cobalt units) without electronic portal imaging. Import of the images into the R and V (Record and Verify) system is required. Material and Methods: Simulator images are grabbed while portal films scanned by using a laser scanner and both converted into DICOM RT (Digital Imaging and Communications in Medicine Radiotherapy) images. Results: Image intensifier output of a simulator and portal films are converted to DICOM RT images and used in clinical practice. The simulator software was developed in cooperation at the authors' hospital. Conclusion: The digitalization of analog simulators is a valuable updating in clinical use replacing screen-film technique. Film scanning and digitalization permit the electronic archiving of films. Conversion into DICOM RT images is a precondition of importing to the R and V system. (orig.)

Development of a computerized portal verification scheme for pelvic treatment fields

International Nuclear Information System (INIS)

Nie, K.; Yin, F.-F.; Gao, Q.; Brasacchio, R.

1996-01-01

Purpose/Objective: At present, treatment verification between portal and reference images is performed based on manually-identified features by radiation oncologist, which is both time-consuming and potentially error-prone. There is a demand for the computerized verification procedure in clinical application. The purpose of this study is to develop a computerized portal verification scheme for pelvic treatment fields. Materials/Methods: The automated verification system involves image acquisition, image feature extraction, feature matching between reference and portal images and quantitative evaluation of patient setup. Electronic portal images with a matrix size of 256 x 256 and 12 bit gray levels were acquired using a liquid matrix electronic portal imaging device. Simulation images were acquired by digitizing simulation films using a TV camera into images with 256 x 256 matrix and 8 bit gray levels. Initially a Canny edge detector is applied to identify the field edges and an elliptic Fourier transformation is used to correlate the size and shape information between the reference and portal field edges. Several measures can be calculated using the transformation coefficients to describe the field shape, size and orientation. The quantitative information regarding to the relative shifts, rotation and magnification factor between portal and reference field edges can then be determined based on these measures. Next the pelvic brim, which is typically used as the landmark for radiation treatment verification, is identified by a pyramid searching process with double snakes defined from initial global area to final local area. A snake is an active model and energy-minimizing spline guided by external constraint forces and influenced by image forces that pull it toward features such as lines and edges. The search range is limited to the region between two snakes. Sobel edge detector and wavelet transformation approach are used to generate a serial image forces at

Semiconductor-based, large-area, flexible, electronic devices on {110} oriented substrates

Science.gov (United States)

Goyal, Amit

2014-08-05

Novel articles and methods to fabricate the same resulting in flexible, oriented, semiconductor-based, electronic devices on {110} textured substrates are disclosed. Potential applications of resulting articles are in areas of photovoltaic devices, flat-panel displays, thermophotovoltaic devices, ferroelectric devices, light emitting diode devices, computer hard disc drive devices, magnetoresistance based devices, photoluminescence based devices, non-volatile memory devices, dielectric devices, thermoelectric devices and quantum dot laser devices.

Fundamental factors influencing portal image quality

International Nuclear Information System (INIS)

Jaffray, D.A.

1995-01-01

It has been recognized that improved methods of verifying radiation field placement in external beam radiotherapy are required in order to make frequent checks of field placement feasible. As a result, a large number of electronic portal imaging systems have been developed as possible replacements for film. These developments have produced digital systems with faster acquisition and improved display contrast, however, the quality of the images acquired with such systems is still disappointing. This presentation examines many of the fundamental factors which limit the quality of radiographs obtained with a megavoltage radiotherapy beam. The size and shape of the radiation sources (focal and extra-focal) in radiotherapy machines and their influence on the spatial resolution of portal images are examined. Monte Carlo simulations of x-ray interactions within the patient determined that a significant fraction of the x-ray scatter generated in the patient is due to bremsstrahlung and positron annihilation. Depending on the detector, the scatter signal can reduce the differential signal-to-noise by 20%. Furthermore, a Monte Carlo study of the interaction of x-rays within typical fluoroscopic imaging detectors (metal plate/phosphor screen) demonstrates the degrading effect of energy absorption noise on the detective quantum efficiency of fluoroscopic based imaging systems. Finally, the spatial frequency content in the x-ray shadowgram is demonstrated to change with x-ray energy, resulting in images that appear to have reduced spatial resolution at megavoltage energies. The relative magnitude of each of these factors will be presented and recommendations for the next generation of portal imaging systems will be made

Dosimetric characterization of an electronic portal imaging device (EPID) and development of a portal dosimetry simple model; Caracterizacion dosimetrica de un dispositivo electronico de imagen portal (EPID) y desarrollo de un modelo simple de dosimetria portal

Energy Technology Data Exchange (ETDEWEB)

Ripol ValentIn, O.; GarcIa Romero, A.; Hernandez Vitoria, A.; Jimenez Albericio, J.; Cortes Rodicio, J.; Millan Cebrian, E.; Ruiz Manzano, P.; Canellas Anoz, M.

2010-07-01

The use of the Electronic Portal Imaging Devices (EPID) for the quality control of linear accelerators of electrons is increasingly extended in practice. In this work the dosimetric characteristics of an EPID OptiVue{sup TM}1000 ST were studied and a friendly and simple method for the absorbed dose calibration was suggested. This method is based on a simple mathematical model, including: an absorbed dose transformation coefficient and image lag and field shape corrections. Software tools were developed in order to process the information and the results were validated by comparing them with the measured data with ionization chambers. The studied device showed suitable characteristics for its use for EPID dosimetry and the calculated results fitted satisfactorily with the dose planes obtained with the ionization chambers. Keeping in mind the model limitations, we concluded that it is possible to start the use of the EPID for the accelerator quality control and improvements for the current model should be studied, as well as other suitable applications: e.g. the Intensity Modulated Radiation Therapy (IMRT) treatment verification procedures. (Author).

New Technology and Experimental Study on Snow-Melting Heated Pavement System in Tunnel Portal

Directory of Open Access Journals (Sweden)

Jinxing Lai

2015-01-01

Full Text Available In recent years, with the rapid growth of economy and sharp rise of motor vehicles in China, the pavement skid resistance in tunnel portals has become increasingly important in cold region. However, the deicing salt, snow removal with machine, and other antiskid measures adopted by highway maintenance division have many limitations. To improve the treatment effect, we proposed a new snow-melting approach employing electric heat tracing, in which heating cables are installed in the structural layer of road. Through the field experiment, laboratory experiment, and numerical investigation, structure type, heating power, and preheating time of the flexible pavement heating system in tunnel portal were systematically analyzed, and advantages of electric heat tracing technology in improving the pavement skid resistance in tunnel portal were also presented. Therefore, such new technology, which offers new snow-melting methods for tunnel portal, bridge, mountainous area, and large longitudinal slope in cold region, has promising prospect for extensive application.

Obliterative portal venopathy without portal hypertension: an underestimated condition.

Science.gov (United States)

Guido, Maria; Sarcognato, Samantha; Sonzogni, Aurelio; Lucà, Maria Grazia; Senzolo, Marco; Fagiuoli, Stefano; Ferrarese, Alberto; Pizzi, Marco; Giacomelli, Luciano; Colloredo, Guido

2016-03-01

Obliterative portal venopathy without portal hypertension has been described by a single study in a limited number of patients, thus very little is known about this clinical condition. This study aimed to investigate the prevalence of obliterative portal venopathy and its clinical-pathological correlations in patients with cryptogenic chronic liver test abnormalities without clinical signs of portal hypertension. We analysed 482 liver biopsies from adults with non-cirrhotic cryptogenic chronic liver disorders and without any clinical signs of portal hypertension, consecutively enrolled in a 5-year period. Twenty cases of idiopathic non-cirrhotic portal hypertension diagnosed in the same period, were included for comparison. Histological findings were matched with clinical and laboratory features. Obliterative portal venopathy was identified in 94 (19.5%) of 482 subjects and in all 20 cases of idiopathic non-cirrhotic portal hypertension: both groups shared the entire spectrum of histological changes described in the latter condition. The prevalence of incomplete fibrous septa and nodular regenerative hyperplasia was higher in the biopsies of idiopathic non-cirrhotic portal hypertension (P = 0.006 and P = 0.002), a possible hint of a more advanced stage of the disease. The two groups also shared several clinical laboratory features, including a similar liver function test profile, concomitant prothrombotic conditions and extrahepatic autoimmune disorders. Obliterative portal venopathy occurs in a substantial proportion of patients with unexplained chronic abnormal liver function tests without portal hypertension. The clinical-pathological profile of these subjects suggests that they may be in an early (non-symptomatic) stage of idiopathic non-cirrhotic portal hypertension. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Inkjet printing as a roll-to-roll compatible technology for the production of large area electronic devices on a pre-industrial scale

NARCIS (Netherlands)

Teunissen, P.; Rubingh, E.; Lammeren, T. van; Abbel, R.J.; Groen, P.

2014-01-01

Inkjet printing is a promising approach towards the solution processing of electronic devices on an industrial scale. Of particular interest is the production of high-end applications such as large area OLEDs on flexible substrates. Roll-to-roll (R2R) processing technologies involving inkjet

Treatment verification with megavoltage electronic portal imaging applied to the tomotherapy concept

International Nuclear Information System (INIS)

Hesse, B.-M.; Spies, L.; Groh, B.; Doll, J.; Haering, P.; Hoever, K. H.

1997-01-01

Purpose: A new treatment strategy called Tomotherapy, introduced by T. R. Mackie et al. in 1993, was designed to perform a dynamic conformal treatment technique in precision radiotherapy. This technique delivers sliced intensity-modulated radiation fields to achieve best tumor control while sparing neighbouring sensitive normal tissue and organs at risk. The beam continuously revolves around the patient similarly to a spiral-CT while the patient is moved through the bore of the gantry. As a first step towards the realization of such a concept with a linear accelerator (Siemens Mevatron Experimental) used in clinical routine, we focused on treatment setup and dose verification. In tomotherapy, an actual CT data set is needed for patient positioning and for the verification of the absorbed dose, also, the dose transmitted through the patient must be known. This makes possible both routine tomographic treatment setup verification and tomographic dose reconstruction of the actual delivered dose. Materials and Methods: All measurements were performed with a megavoltage electronic portal imaging device of Wellhoefer TM (BIS-710). The BIS-710 detector is based on a scintillation foil and contains a camera for 10-bit digital data output. The dimension of the detector plane is 512 x 512 pixels with a pixel size of 0.6 mm in each direction. The BIS-710 was developed especially for quantitative dose measuring, whereas most of the existing Portal Imaging Systems are used for image display only. To examine the properties of the BIS-710 concerning tomographical reconstruction with a therapeutic 6 MV X-ray beam, a tissue-equivalent Alderson head phantom was rotated stepwise across a stationary beam between the collimator and the detector plane. The influence of scattering can be estimated by comparing measurements which were taken with a homogeneous phantom which is invariant under rotation with a calculated exit dose distribution using a simple exponential law for the

Editor's welcome, PORTAL, Vol. 1, No. 1, January 2004

Directory of Open Access Journals (Sweden)

Paul Allatson

2004-01-01

Full Text Available Welcome to the inaugural issue of PORTAL On behalf of the Executive Editorial Committee of PORTAL Journal of Multidisciplinary International Studies, it is a great pleasure to announce the virtual birth of this fully peer-reviewed journal under the auspices of UTSePress, the exciting new electronic publishing enterprise housed at the central library at the University of Technology, Sydney (UTS, Australia. PORTAL itself is edited by staff from the Institute for International Studies, a dynamic research and teaching centre at UTS. The launch of PORTAL's inaugural issue will take place simultaneously in Sydney, Australia, and Guadalajara, México, on January 28 (Sydney / 27 (Guadalajara 2004. The trans-Pacific axial enabling this twin launch is emblematic of the many axes of dialogue that, it is to be hoped, will characterize the content and reception of this and future issues of Portal. We are grateful to the many people at the Center for Social Sciences and Humanities at la Universidad de Guadalajara, México, for their provision of the technologies and tequila that will facilitate Portal's digital launch in a different space and timezone to its 'homebirth' in Sydney, Australia. As PORTAL's 'Focus and Scope' statement indicates, the journal is dedicated to publishing scholarship by practitioners of-and dissenters from-international, regional, area, migration, and ethnic studies. PORTAL is also committed to providing a space for cultural producers interested in the internationalization of cultures. With these aims in mind we have conceived PORTAL as a "multidisciplinary venture," to use Michel Chaouli's words. That is, PORTAL signifies "a place where researchers [and cultural producers] are exposed to different ways of posing questions and proffering answers, without creating out of their differing disciplinary languages a common theoretical or methodological pidgin" (2003, p. 57. Our hope is that scholars working in the humanities

Search for Cosmic-Ray Electron and Positron Anisotropies with Seven Years of Fermi Large Area Telescope Data

International Nuclear Information System (INIS)

Abdollahi, S.; Ackermann, M.; Ajello, M.; Albert, A.; Atwood, W. B.

2017-01-01

We present the Large Area Telescope on board the Fermi Gamma-ray Space Telescope that has collected the largest ever sample of high-energy cosmic-ray electron and positron events since the beginning of its operation. Potential anisotropies in the arrival directions of cosmic-ray electrons or positrons could be a signature of the presence of nearby sources. We use almost seven years of data with energies above 42 GeV processed with the Pass 8 reconstruction. The present data sample can probe dipole anisotropies down to a level of 10"-"3. We take into account systematic effects that could mimic true anisotropies at this level. We present a detailed study of the event selection optimization of the cosmic-ray electrons and positrons to be used for anisotropy searches. Since no significant anisotropies have been detected on any angular scale, we present upper limits on the dipole anisotropy. Lastly, the present constraints are among the strongest to date probing the presence of nearby young and middle-aged sources.

Electronic portal imaging device detection of radioopaque markers for the evaluation of prostate position during megavoltage irradiation: a clinical study

International Nuclear Information System (INIS)

Vigneault, Eric; Pouliot, Jean; Laverdiere, Jacques; Roy, Jean; Dorion, Marc

1997-01-01

Purpose: This study was designed to assess daily prostatic apex motion relative to pelvic bone structures during megavoltage irradiation. Methods and Materials: Radioopaque markers were implanted under ultrasound guidance near the prostatic apex of 11 patients with localized prostatic carcinoma. Patients were subsequently treated with a four field-box technique at a beam energy of 23 MV. During treatment, on-line images were obtained with an electronic portal imaging device (EPID). The marker was easily identified, even on unprocessed images, and the distance between the marker and a bony landmark was measured. Timelapse movies were also reviewed. After the completion of treatment, a transcrectal ultrasound examination was performed in 8 of 11 patients, to verify the position of the marker. Results: We acquired over 900 digital portal images and analyzed posterioanterior and right lateral views. The quality of portal images obtained with megavoltage irradiation was good. It was possible to evaluate pelvic bone structures even without image histogram equalization. Moreover, the radioopaque marker was easily visible on every online portal image. The review of timelapse movies showed important interfraction motion of the marker while bone structures remained stable. We measured the position of the marker for each fraction. Marker displacements up to 1.6 cm were measured between 2 consecutive days of treatment. Important marker motions were predominantly in the posteroanterior and cephalocaudal directions. In eight patients, we verified the position of the marker relative to the prostatic apex with ultrasound at the end of the treatments. The marker remained in the trapezoid zone. Intratreatment images reviewed in two cases showed no change in marker position. Our results, obtained during the treatment courses, indicate similar or larger prostate motions than previously observed in studies that used intertreatment x-ray films and CT images. Marker implantation under

Clean-lifting transfer of large-area residual-free graphene films.

Science.gov (United States)

Wang, Di-Yan; Huang, I-Sheng; Ho, Po-Hsun; Li, Shao-Sian; Yeh, Yun-Chieh; Wang, Duan-Wei; Chen, Wei-Liang; Lee, Yu-Yang; Chang, Yu-Ming; Chen, Chia-Chun; Liang, Chi-Te; Chen, Chun-Wei

2013-08-27

A unique "clean-lifting transfer" (CLT) technique that applies a controllable electrostatic force to transfer large-area and high-quality CVD-grown graphene onto various rigid or flexible substrates is reported. The CLT technique without using any organic support or adhesives can produce residual-free graphene films with large-area processability, and has great potential for future industrial production of graphene-based electronics or optoelectronics. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Radioisotopic flow scanning for portal blood flow and portal hypertension

International Nuclear Information System (INIS)

Hesdorffer, C.S.; Bezwoda, W.R.; Danilewitz, M.D.; Esser, J.D.; Tobias, M.

1987-01-01

The use of a simple, noninvasive, isotope scanning technique for the determination of relative portal blood flow and detection of portal hypertension is described. Using this technique the presence of portal hypertension was demonstrated in seven of nine patients known to have elevated portal venous pressure. By contrast, esophageal varices were demonstrated in only five of these patients, illustrating the potential value of the method. Furthermore, this technique has been adapted to the study of portal blood flow in patients with myeloproliferative disorders with splenomegaly but without disturbances in hepatic architecture. Results demonstrate that the high relative splenic flow resulting from the presence of splenomegaly may in turn be associated with elevated relative portal blood flow and portal hypertension. The theoretic reasons for the development of flow-related portal hypertension and its relationship to splenic blood flow are discussed

CT portal venography manifestations of portal collateral circulation in patients with portal hypertension due to cirrhosis

International Nuclear Information System (INIS)

Ni Ming; Lv Weifu; Deng Kexue

2009-01-01

Objective: To analyze CT portal venography (CTPV) manifestations of portal collateral circulation in patients with cirrhosis by using a 16-detector row spiral CT scanner. Methods: CTPV was performed in 36 patients with portal hypertension due to cirrhosis, the diagnosis was proved by clinical data, hepatic function findings and imaging signs. By using post-processing reconstruction technique, 3D images of portal venous system and portal collateral circulation were obtained. Results: CTPV images displayed the portal venous system and its collateral circulation stereoscopically. Of 36 patients, left gastric varices were seen in 29(80.6%), lower esophageal varices in 18(50.0%), short gastric or posterior gastric varices in 15(41.7%), paraesophageal varices in 9(25.0%), gastro-renal or splenorenal shunts in 8(22.2%), spongelike transformation of portal vein in 7(19.4%), paraumbilical and abdominal wall varices in 6(16.7%), congenital cavernous in 6(16.7%) and paravertebral venous shunts in 4(11.1%). Conclusion: CTPV can well display the site, extent and severity of the portal collateral circulation in patients with portal hypertension due to cirrhosis,which is of great clinical importance for judging the patient's condition, for selecting therapeutic protocols and for estimating prognosis. (authors)

Large-Area Chemical Vapor Deposited MoS2 with Transparent Conducting Oxide Contacts toward Fully Transparent 2D Electronics

KAUST Repository

Dai, Zhenyu

2017-09-08

2D semiconductors are poised to revolutionize the future of electronics and photonics, much like transparent oxide conductors and semiconductors have revolutionized the display industry. Herein, these two types of materials are combined to realize fully transparent 2D electronic devices and circuits. Specifically, a large-area chemical vapor deposition process is developed to grow monolayer MoS2 continuous films, which are, for the first time, combined with transparent conducting oxide (TCO) contacts. Transparent conducting aluminum doped zinc oxide contacts are deposited by atomic layer deposition, with composition tuning to achieve optimal conductivity and band-offsets with MoS2. The optimized process gives fully transparent TCO/MoS2 2D electronics with average visible-range transmittance of 85%. The transistors show high mobility (4.2 cm2 V−1 s−1), fast switching speed (0.114 V dec−1), very low threshold voltage (0.69 V), and large switching ratio (4 × 108). To our knowledge, these are the lowest threshold voltage and subthreshold swing values reported for monolayer chemical vapor deposition MoS2 transistors. The transparent inverters show fast switching properties with a gain of 155 at a supply voltage of 10 V. The results demonstrate that transparent conducting oxides can be used as contact materials for 2D semiconductors, which opens new possibilities in 2D electronic and photonic applications.

Transhepatic course of the portal vein with subcapsular ramification

Energy Technology Data Exchange (ETDEWEB)

Goebel, N

1985-06-01

In a patient, investigated for uterine carcinoma, CT of the liver showed an anomalous course of a large portal vein, which traversed the liver and divided under the ventrolateral liver capsule in its branches. There were no signs of portal hypertension.

OntoFire: an ontology-based geo-portal for wildfires

Science.gov (United States)

Kalabokidis, K.; Athanasis, N.; Vaitis, M.

2011-12-01

With the proliferation of the geospatial technologies on the Internet, the role of geo-portals (i.e. gateways to Spatial Data Infrastructures) in the area of wildfires management emerges. However, keyword-based techniques often frustrate users when looking for data of interest in geo-portal environments, while little attention has been paid to shift from the conventional keyword-based to navigation-based mechanisms. The presented OntoFire system is an ontology-based geo-portal about wildfires. Through the proposed navigation mechanisms, the relationships between the data can be discovered, which would otherwise not be possible when using conventional querying techniques alone. End users can use the browsing interface to find resources of interest by using the navigation mechanisms provided. Data providers can use the publishing interface to submit new metadata, modify metadata or removing metadata in/from the catalogue. The proposed approach can improve the discovery of valuable information that is necessary to set priorities for disaster mitigation and prevention strategies. OntoFire aspires to be a focal point of integration and management of a very large amount of information, contributing in this way to the dissemination of knowledge and to the preparedness of the operational stakeholders.

Technique investigation on large area neutron scintillation detector array

International Nuclear Information System (INIS)

Chen Jiabin

2006-12-01

The detailed project for developing Large Area Neutron Scintillation Detector Array (LaNSA) to be used for measuring fusion fuel area density on Shenguang III prototype is presented, including experimental principle, detector working principle, electronics system design and the needs for target chamber etc. The detailed parameters for parts are given and the main causes affecting the system function are analyzed. The realization path is introduced. (authors)

Portal Hypertension

Science.gov (United States)

... Overview of Gallbladder Cancer Additional Content Medical News Portal Hypertension By Steven K. Herrine, MD, Professor of Medicine, ... Liver Hepatic Encephalopathy Jaundice in Adults Liver Failure Portal Hypertension Portal hypertension is abnormally high blood pressure in ...

Using Patient Portals to Increase Engagement in Patients with Cancer.

Science.gov (United States)

Rodriguez, Elizabeth S

2018-04-03

To review patient portals which serve as a tool for patient engagement by increasing access to electronic health care information and expanding ways to communicate with health care providers. Reviews of the literature and first-hand experience. Meaningful Use requirements propelled the design and development of patient portals in recent years. Patient engagement in oncology can improve quality of life and outcomes. Oncology nurses facilitate patient adoption of patient portals and support usage. Patient education helps manage communication expectations and understanding of online medical information. Copyright © 2018 Elsevier Inc. All rights reserved.

Patient portals and broadband internet inequality.

Science.gov (United States)

Perzynski, Adam T; Roach, Mary Joan; Shick, Sarah; Callahan, Bill; Gunzler, Douglas; Cebul, Randall; Kaelber, David C; Huml, Anne; Thornton, John Daryl; Einstadter, Douglas

2017-09-01

Patient portals have shown potential for increasing health care quality and efficiency. Internet access and other factors influencing patient portal use could worsen health disparities. Observational study of adults with 1 or more visits to the outpatient clinics of an urban public health care system from 2012 to 2015. We used mixed effects logistic regression to evaluate the association between broadband internet access and (1) patient portal initiation (whether a patient logged in at least 1 time) and (2) messaging, controlling for demographic and neighborhood characteristics. There were 243 248 adults with 1 or more visits during 2012-2015 and 70 835 (29.1%) initiated portal use. Portal initiation was 34.1% for whites, 23.4% for blacks, and 23.8% for Hispanics, and was lower for Medicaid (26.5%), Medicare (23.4%), and uninsured patients (17.4%) than commercially insured patients (39.3%). In multivariate analysis, both initiation of portal use (odds ratio [OR] = 1.24 per quintile, 95% confidence interval [CI], 1.23-1.24, P  internet access. The majority of adults with outpatient visits to a large urban health care system did not use the patient portal, and initiation of use was lower for racial and ethnic minorities, persons of lower socioeconomic status, and those without neighborhood broadband internet access. These results suggest the emergence of a digital divide in patient portal use. Given the scale of investment in patient portals and other internet-dependent health information technologies, efforts are urgently needed to address this growing inequality. © The Author 2017. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Portal monitoring for detecting fissile materials and chemical explosives

International Nuclear Information System (INIS)

Albright, D.

1992-01-01

The portal monitoring of pedestrians, packages, equipment, and vehicles entering or leaving areas of high physical security has been common for many years. Many nuclear facilities rely on portal monitoring to prevent the theft or diversion of plutonium and highly enriched uranium. At commercial airports, portals are used to prevent firearms and explosives from being smuggled onto airplanes. An August 1989 Federal Aviation Administration (FAA) regulation requires US airlines to screen luggage on international flights for chemical explosives. This paper reports that portal monitoring is now being introduced into arms-control agreements. Because some of the portal-monitoring equipment that would be useful in verifying arms-control agreements is already widely used as part of the physical security systems at nuclear facilities and commercial airports, the authors review these uses of portal monitoring, as well as its role in verifying the INF treaty. Then the authors survey the major types of portal-monitoring equipment that would be most useful in detecting nuclear warheads or fissile material

Investigation of tilted dose kernels for portal dose prediction in a-Si electronic portal imagers

International Nuclear Information System (INIS)

Chytyk, K.; McCurdy, B. M. C.

2006-01-01

The effect of beam divergence on dose calculation via Monte Carlo generated dose kernels was investigated in an amorphous silicon electronic portal imaging device (EPID). The flat-panel detector was simulated in EGSnrc with an additional 3.0 cm water buildup. The model included details of the detector's imaging cassette and the front cover upstream of it. To approximate the effect of the EPID's rear housing, a 2.1 cm air gap and 1.0 cm water slab were introduced into the simulation as equivalent backscatter material. Dose kernels were generated with an incident pencil beam of monoenergetic photons of energy 0.1, 2, 6, and 18 MeV. The orientation of the incident pencil beam was varied from 0 deg. to 14 deg. in 2 deg. increments. Dose was scored in the phosphor layer of the detector in both cylindrical (at 0 deg. ) and Cartesian (at 0 deg. -14 deg.) geometries. To reduce statistical fluctuations in the Cartesian geometry simulations at large radial distances from the incident pencil beam, the voxels were first averaged bilaterally about the pencil beam and then combined into concentric square rings of voxels. Profiles of the EPID dose kernels displayed increasing asymmetry with increasing angle and energy. A comparison of the superposition (tilted kernels) and convolution (parallel kernels) dose calculation methods via the χ-comparison test (a derivative of the γ-evaluation) in worst-case-scenario geometries demonstrated an agreement between the two methods within 0.0784 cm (one pixel width) distance-to-agreement and up to a 1.8% dose difference. More clinically typical field sizes and source-to-detector distances were also tested, yielding at most a 1.0% dose difference and the same distance-to-agreement. Therefore, the assumption of parallel dose kernels has less than a 1.8% dosimetric effect in extreme cases and less than a 1.0% dosimetric effect in most clinically relevant situations and should be suitable for most clinical dosimetric applications. The

Genomics Portals: integrative web-platform for mining genomics data.

Science.gov (United States)

Shinde, Kaustubh; Phatak, Mukta; Johannes, Freudenberg M; Chen, Jing; Li, Qian; Vineet, Joshi K; Hu, Zhen; Ghosh, Krishnendu; Meller, Jaroslaw; Medvedovic, Mario

2010-01-13

A large amount of experimental data generated by modern high-throughput technologies is available through various public repositories. Our knowledge about molecular interaction networks, functional biological pathways and transcriptional regulatory modules is rapidly expanding, and is being organized in lists of functionally related genes. Jointly, these two sources of information hold a tremendous potential for gaining new insights into functioning of living systems. Genomics Portals platform integrates access to an extensive knowledge base and a large database of human, mouse, and rat genomics data with basic analytical visualization tools. It provides the context for analyzing and interpreting new experimental data and the tool for effective mining of a large number of publicly available genomics datasets stored in the back-end databases. The uniqueness of this platform lies in the volume and the diversity of genomics data that can be accessed and analyzed (gene expression, ChIP-chip, ChIP-seq, epigenomics, computationally predicted binding sites, etc), and the integration with an extensive knowledge base that can be used in such analysis. The integrated access to primary genomics data, functional knowledge and analytical tools makes Genomics Portals platform a unique tool for interpreting results of new genomics experiments and for mining the vast amount of data stored in the Genomics Portals backend databases. Genomics Portals can be accessed and used freely at http://GenomicsPortals.org.

Inpatient Portals for Hospitalized Patients and Caregivers: A Systematic Review.

Science.gov (United States)

Kelly, Michelle M; Coller, Ryan J; Hoonakker, Peter Lt

2018-06-01

Patient portals, web-based personal health records linked to electronic health records (EHRs), provide patients access to their healthcare information and facilitate communication with providers. Growing evidence supports portal use in ambulatory settings; however, only recently have portals been used with hospitalized patients. Our objective was to review the literature evaluating the design, use, and impact of inpatient portals, which are patient portals designed to give hospitalized patients and caregivers inpatient EHR clinical information for the purpose of engaging them in hospital care. Literature was reviewed from 2006 to 2017 in PubMed, Web of Science, CINALPlus, Cochrane, and Scopus to identify English language studies evaluating patient portals, engagement, and inpatient care. Data were analyzed considering the following 3 themes: inpatient portal design, use and usability, and impact. Of 731 studies, 17 were included, 9 of which were published after 2015. Most studies were qualitative with small samples focusing on inpatient portal design; 1 nonrandomized trial was identified. Studies described hospitalized patients' and caregivers' information needs and design recommendations. Most patient and caregiver participants in included studies were interested in using an inpatient portal, used it when offered, and found it easy to use and/or useful. Evidence supporting the role of inpatient portals in improving patient and caregiver engagement, knowledge, communication, and care quality and safety is limited. Included studies indicated providers had concerns about using inpatient portals; however, the extent to which these concerns have been realized remains unclear. Inpatient portal research is emerging. Further investigation is needed to optimally design inpatient portals to maximize potential benefits for hospitalized patients and caregivers while minimizing unintended consequences for healthcare teams. © 2017 Society of Hospital Medicine.

The SNS/HFIR Web Portal System for SANS

International Nuclear Information System (INIS)

Campbell, Stuart I; Miller, Stephen D; Bilheux, Jean-Christophe; Reuter, Michael A; Peterson, Peter F; Kohl, James A; Trater, James R; Vazhkudai, Sudharshan S; Lynch, Vickie E; Green, Mark L

2010-01-01

The new generation of neutron scattering instruments being built are higher resolution and produce one or more orders of magnitude larger data than the previous generation of instruments. For instance, we have grown out of being able to perform some important tasks with our laptops. The data sizes are too big and the computational time would be too long. These large datasets can be problematic as facility users now begin to struggle with many of the same issues faced by more established computing communities. These issues include data access, management, and movement, data format standards, distributed computing, and collaboration with others. The Neutron Science Portal has been designed, and implemented to provide users with an easy-to-use interface for managing and processing data, while also keeping an eye on meeting modern computer security requirements that are currently being imposed on institutions. Users can browse or search for data which they are allowed to see, run data reduction and analysis applications, perform sample activation calculations and perform McStas simulations. Collaboration is facilitated by providing users a read/writeable common area, shared across all experiment team members. The portal currently has over 370 registered users; almost 7TB of experiment and user data, approximately 1,000,000 files cataloged, and had almost 10,000 unique visits last year. Future directions for enhancing portal robustness include examining how to mirror data and portal services, better facilitation of collaborations via virtual organizations, enhancing disconnected service via 'thick client' applications, and better inter-facility connectivity to support cross-cutting research.

An automated portal verification system for the tangential breast portal field

International Nuclear Information System (INIS)

Yin, F.-F.; Lai, W.; Chen, C. W.; Nelson, D. F.

1995-01-01

Purpose/Objective: In order to ensure the treatment is delivered as planned, a portal image is acquired in the accelerator and is compared to the reference image. At present, this comparison is performed by radiation oncologists based on the manually-identified features, which is both time-consuming and potentially error-prone. With the introduction of various electronic portal imaging devices, real-time patient positioning correction is becoming clinically feasible to replace time-delayed analysis using films. However, this procedure requires present of radiation oncologists during patient treatment which is not cost-effective and practically not realistic. Therefore, the efficiency and quality of radiation therapy could be substantially improved if this procedure can be automated. The purpose of this study is to develop a fully computerized verification system for the radiation therapy of breast cancer for which a similar treatment setup is generally employed. Materials/Methods: The automated verification system involves image acquisition, image feature extraction, feature correlation between reference and portal images, and quantitative evaluation of patient setup. In this study, a matrix liquid ion-chamber EPID was used to acquire digital portal images which is directly attached to Varian CL2100C accelerator. For effective use of computation memory, the 12-bit gray levels in original portal images were quantized to form a range of 8-bit gray levels. A typical breast portal image includes three important components: breast and lung tissues in the treatment field, air space within the treatment field, and non-irradiated region. A hierarchical region processing technique was developed to separate these regions sequentially. The inherent hierarchical features were formulated based on different radiation attenuation for different regions as: treatment field edge -- breast skin line -- chest wall. Initially, a combination of a Canny edge detector and a constrained

Large area x-ray detectors for cargo radiography

Science.gov (United States)

Bueno, C.; Albagli, D.; Bendahan, J.; Castleberry, D.; Gordon, C.; Hopkins, F.; Ross, W.

2007-04-01

Large area x-ray detectors based on phosphors coupled to flat panel amorphous silicon diode technology offer significant advances for cargo radiologic imaging. Flat panel area detectors provide large object coverage offering high throughput inspections to meet the high flow rate of container commerce. These detectors provide excellent spatial resolution when needed, and enhanced SNR through low noise electronics. If the resolution is reduced through pixel binning, further advances in SNR are achievable. Extended exposure imaging and frame averaging enables improved x-ray penetration of ultra-thick objects, or "select-your-own" contrast sensitivity at a rate many times faster than LDAs. The areal coverage of flat panel technology provides inherent volumetric imaging with the appropriate scanning methods. Flat panel area detectors have flexible designs in terms of electronic control, scintillator selection, pixel pitch, and frame rates. Their cost is becoming more competitive as production ramps up for the healthcare, nondestructive testing (NDT), and homeland protection industries. Typically used medical and industrial polycrystalline phosphor materials such as Gd2O2S:Tb (GOS) can be applied to megavolt applications if the phosphor layer is sufficiently thick to enhance x-ray absorption, and if a metal radiator is used to augment the quantum detection efficiency and reduce x-ray scatter. Phosphor layers ranging from 0.2-mm to 1-mm can be "sandwiched" between amorphous silicon flat panel diode arrays and metal radiators. Metal plates consisting of W, Pb or Cu, with thicknesses ranging from 0.25-mm to well over 1-mm can be used by covering the entire area of the phosphor plate. In some combinations of high density metal and phosphor layers, the metal plate provides an intensification of 25% in signal due to electron emission from the plate and subsequent excitation within the phosphor material. This further improves the SNR of the system.

Racial/ethnic variation in devices used to access patient portals.

Science.gov (United States)

Chang, Eva; Blondon, Katherine; Lyles, Courtney R; Jordan, Luesa; Ralston, James D

2018-01-01

We examined racial/ethnic variation in the devices used by patients to access medical records through an online patient portal. Retrospective, cross-sectional analysis. Using data from 318,700 adults enrolled in an integrated delivery system between December 2012 and November 2013, we examined: 1) online patient portal use that directly engages the electronic health record and 2) portal use over desktops/laptops only, mobile devices only, or both device types. The primary covariate was race/ethnicity (non-Hispanic white, black, Hispanic, and Asian). Other covariates included age, sex, primary language, and neighborhood-level income and education. Portal use and devices used were assessed with multiple and multinomial logistic models, respectively. From December 2012 to November 2013, 56% of enrollees used the patient portal. Of these portal users, 62% used desktops/laptops only, 6% used mobile devices only, and 32% used both desktops/laptops and mobile devices. Black, Hispanic, and Asian enrollees had significantly lower odds of portal use than whites. Black and Hispanic portal users also were significantly more likely to use mobile devices only (relative risk ratio, 1.73 and 1.44, respectively) and both device types (1.21 and 1.07, respectively) than desktops/laptops only compared with whites. Although racial/ethnic minority enrollees were less likely to access the online patient portal overall, a greater proportion of black and Hispanic users accessed the patient portal with mobile devices than did non-Hispanic white users. The rapid spread of mobile devices among racial/ethnic minorities may help reduce variation in online patient portal use. Mobile device use may represent an opportunity for healthcare organizations to further engage black and Hispanic enrollees in online patient portal use.

On line portal imaging

International Nuclear Information System (INIS)

Munro, Peter

1996-01-01

devices such as for dosimetry will also be investigated. However, the area where most ef fort must be placed is in determining the best way of employing EPIDs clinically. It is only once this is done that the potential of portal imaging technology can be realized

Reasons and barriers for using a patient portal: survey among patients with diabetes mellitus.

Science.gov (United States)

Ronda, Maaike C M; Dijkhorst-Oei, Lioe-Ting; Rutten, Guy E H M

2014-11-25

The use of a Web portal for patients with diabetes mellitus to access their own personal health record may result in improved diabetes outcomes. However, the adoption by patients is slow. This may be caused by patient characteristics, but also by the content, layout, and promotion of the portal. Detailed knowledge about this could help increase patients' participation in Web portals. The aim was to study the opinions of patients with diabetes and identify perceived barriers to using a Web portal to optimize its use. We conducted a survey among patients with type 1 and type 2 diabetes mellitus from 62 primary care practices and 1 outpatient hospital clinic in the central area of the Netherlands who all used the same electronic health record with a Web portal. Questionnaires about patient characteristics, opinions about reasons for use or nonuse, and about portal content were sent to 1500 patients with a login and 3000 patients without a login to the Web portal. Patient groups were stratified according to login frequency. Demographic and diabetes-related variables were analyzed with multivariable regression analysis. The total response rate was 66.63% (2391/4399); 1390 of 4399 patients (31.60%) were eligible for analysis. There were 413 regular users (login frequency more than once) and 758 nonusers (no login). Most nonusers (72.4%) stated that the main reason for not requesting a login was that they were unaware of the existence of the portal. Other barriers reported by patients were disinterest in managing their own disease (28.5%, 216/758) and feelings of inadequacy with the use of computers and Internet (11.6%, 88/758). Patients treated by a general practitioner were more frequently nonusers compared to patients treated by an internist (78.8%, 666/846 vs 28.3%, 92/325; Ppatient portal is the main barrier of enrollment. Users and nonusers perceive the usefulness of the portal differently and do not have the same recommendations for additional functionalities. To

DES Science Portal: Computing Photometric Redshifts

Energy Technology Data Exchange (ETDEWEB)

Gschwend, Julia [LIneA, Rio de Janeiro

2016-01-01

An important challenge facing photometric surveys for cosmological purposes, such as the Dark Energy Survey (DES), is the need to produce reliable photometric redshifts (photo-z). The choice of adequate algorithms and configurations and the maintenance of an up-to-date spectroscopic database to build training sets, for example, are challenging tasks when dealing with large amounts of data that are regularly updated and constantly growing. In this paper, we present the first of a series of tools developed by DES, provided as part of the DES Science Portal, an integrated web-based data portal developed to facilitate the scientific analysis of the data, while ensuring the reproducibility of the analysis. We present the DES Science Portal photometric redshift tools, starting from the creation of a spectroscopic sample to training the neural network photo-z codes, to the final estimation of photo-zs for a large photometric catalog. We illustrate this operation by calculating well calibrated photo-zs for a galaxy sample extracted from the DES first year (Y1A1) data. The series of processes mentioned above is run entirely within the Portal environment, which automatically produces validation metrics, and maintains the provenance between the different steps. This system allows us to fine tune the many steps involved in the process of calculating photo-zs, making sure that we do not lose the information on the configurations and inputs of the previous processes. By matching the DES Y1A1 photometry to a spectroscopic sample, we define different training sets that we use to feed the photo-z algorithms already installed at the Portal. Finally, we validate the results under several conditions, including the case of a sample limited to i<22.5 with the color properties close to the full DES Y1A1 photometric data. This way we compare the performance of multiple methods and training configurations. The infrastructure presented here is an effcient way to test several methods of

29 CFR 785.24 - Principles noted in Portal-to-Portal Bulletin.

Science.gov (United States)

2010-07-01

... 29 Labor 3 2010-07-01 2010-07-01 false Principles noted in Portal-to-Portal Bulletin. 785.24 Section 785.24 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR... of Principles Preparatory and Concluding Activities § 785.24 Principles noted in Portal-to-Portal...

Observer variability when evaluating patient movement from electronic portal images of pelvic radiotherapy fields

International Nuclear Information System (INIS)

Geraint Lewis, D.; Ryan, Karen R.; Smith, Cyril W.

2005-01-01

Background and purpose: A study has been performed to evaluate inter-observer variability when assessing pelvic patient movement using an electronic portal imaging device (EPID). Materials and methods: Four patient image sets were used with 3-6 portal images per set. The observer group consisted of nine radiographers with 3-18 months clinical EPID experience. The observers outlined bony landmarks on a digital simulator image and used matching software to evaluate field placement errors (FPEs) on each portal image relative to the reference simulator image. Data were evaluated statistically, using a two-component analysis of variance technique, to quantify both the inter-observer variability in evaluating FPEs and inter-fraction variability in patient position relative to the residuals of the analysis. Intra-observer variability was also estimated using four of the observers carrying out three sets of repeat readings. Results: Eight sets of variance data were analysed, based on FPEs in two orthogonal directions for each of the four patient image sets studied. Initial analysis showed that both inter-observer variation and inter-fraction-patient position variation were statistically significant (P<0.05) in seven of the eight cases evaluated. The averaged root-mean-square (RMS) deviation of the observers from the group mean was 1.1 mm, with a maximum deviation of 5.0 mm recorded for an individual observer. After additional training and re-testing of two of the observers who recorded the largest deviations from the group mean, a subsequent analysis showed the inter-observer variability for the group to be significant in only three of the eight cases, with averaged RMS deviation reduced to 0.5 mm, with a maximum deviation of 2.7 mm. The intra-observer variability was 0.5 mm, averaged over the four observers tested. Conclusions: We have developed a quantitative approach to evaluate inter-observer variability in terms of its statistical significance compared to inter

Genomics Portals: integrative web-platform for mining genomics data

Directory of Open Access Journals (Sweden)

Ghosh Krishnendu

2010-01-01

Full Text Available Abstract Background A large amount of experimental data generated by modern high-throughput technologies is available through various public repositories. Our knowledge about molecular interaction networks, functional biological pathways and transcriptional regulatory modules is rapidly expanding, and is being organized in lists of functionally related genes. Jointly, these two sources of information hold a tremendous potential for gaining new insights into functioning of living systems. Results Genomics Portals platform integrates access to an extensive knowledge base and a large database of human, mouse, and rat genomics data with basic analytical visualization tools. It provides the context for analyzing and interpreting new experimental data and the tool for effective mining of a large number of publicly available genomics datasets stored in the back-end databases. The uniqueness of this platform lies in the volume and the diversity of genomics data that can be accessed and analyzed (gene expression, ChIP-chip, ChIP-seq, epigenomics, computationally predicted binding sites, etc, and the integration with an extensive knowledge base that can be used in such analysis. Conclusion The integrated access to primary genomics data, functional knowledge and analytical tools makes Genomics Portals platform a unique tool for interpreting results of new genomics experiments and for mining the vast amount of data stored in the Genomics Portals backend databases. Genomics Portals can be accessed and used freely at http://GenomicsPortals.org.

Advances in the management of childhood portal hypertension.

Science.gov (United States)

McKiernan, Patrick; Abdel-Hady, Mona

2015-05-01

Portal hypertension is one of the most serious complications of childhood liver disease, and variceal bleeding is the most feared complication. Most portal hypertension results from cirrhosis but extra hepatic portal vein obstruction is the single commonest cause. Upper gastrointestinal endoscopy endoscopy remains necessary to diagnose gastro-esophageal varices. Families of children with portal hypertension should be provided with written instructions in case of gastrointestinal bleeding. Children with large varices should be considered for primary prophylaxis on a case-by-case basis. The preferred method is variceal band ligation. Children with acute bleeding should be admitted to hospital and treated with antibiotics and pharmacotherapy before urgent therapeutic endoscopy. All children who have bled should then receive secondary prophylaxis. The preferred method is variceal band ligation and as yet there is little evidence to support the use of β-blockers. Children with extrahepatic portal vein obstruction should be assessed for suitability of mesoportal bypass.

OntoFire: an ontology-based geo-portal for wildfires

Directory of Open Access Journals (Sweden)

K. Kalabokidis

2011-12-01

Full Text Available With the proliferation of the geospatial technologies on the Internet, the role of geo-portals (i.e. gateways to Spatial Data Infrastructures in the area of wildfires management emerges. However, keyword-based techniques often frustrate users when looking for data of interest in geo-portal environments, while little attention has been paid to shift from the conventional keyword-based to navigation-based mechanisms. The presented OntoFire system is an ontology-based geo-portal about wildfires. Through the proposed navigation mechanisms, the relationships between the data can be discovered, which would otherwise not be possible when using conventional querying techniques alone. End users can use the browsing interface to find resources of interest by using the navigation mechanisms provided. Data providers can use the publishing interface to submit new metadata, modify metadata or removing metadata in/from the catalogue. The proposed approach can improve the discovery of valuable information that is necessary to set priorities for disaster mitigation and prevention strategies. OntoFire aspires to be a focal point of integration and management of a very large amount of information, contributing in this way to the dissemination of knowledge and to the preparedness of the operational stakeholders.

Evaluation of respiratory movement during gated radiotherapy using film and electronic portal imaging

International Nuclear Information System (INIS)

Ford, E.C.; Mageras, G.S.; Yorke, E.; Rosenzweig, K.E.; Wagman, R.; Ling, C.C.

2002-01-01

Purpose: To evaluate the effectiveness of a commercial system in reducing respiration-induced treatment uncertainty by gating the radiation delivery. Methods and Materials: The gating system considered here measures respiration from the position of a reflective marker on the patient's chest. Respiration-triggered planning CT scans were obtained for 8 patients (4 lung, 4 liver) at the intended phase of respiration (6 at end expiration and 2 at end inspiration). In addition, fluoroscopic movies were recorded simultaneously with the respiratory waveform. During the treatment sessions, gated localization films were used to measure the position of the diaphragm relative to the vertebral bodies, which was compared to the reference digitally reconstructed radiograph derived from the respiration-triggered planning CT. Variability was quantified by the standard deviation about the mean position. We also assessed the interfraction variability of soft tissue structures during gated treatment in 2 patients using an amorphous silicon electronic portal imaging device. Results: The gated localization films revealed an interfraction patient-averaged diaphragm variability of 2.8±1.0 mm (error bars indicate standard deviation in the patient population). The fluoroscopic data yielded a patient-averaged intrafraction diaphragm variability of 2.6±1.7 mm. With no gating, this intrafraction excursion became 6.9±2.1 mm. In gated localization films, the patient-averaged mean displacement of the diaphragm from the planning position was 0.0±3.9 mm. However, in 4 of the 8 patients, the mean (over localization films) displacement was >4 mm, indicating a systematic displacement in treatment position from the planned one. The position of soft tissue features observed in portal images during gated treatments over several fractions showed a mean variability between 2.6 and 5.7 mm. The intrafraction variability, however, was between 0.6 and 1.4 mm, indicating that most of the variability was

Teen use of a patient portal: a qualitative study of parent and teen attitudes.

Science.gov (United States)

Bergman, David A; Brown, Nancy L; Wilson, Sandra

2008-01-01

We conducted a qualitative study of the attitudes of teens and parents toward the use of a patient portal. We conducted two teen and two parent focus groups, one teen electronic bulletin board, and one parent electronic bulletin board. Videotapes and transcripts from the groups were independently analyzed by two reviewers for significant themes, which were then validated by two other members of the research team. Twenty-eight teens and 23 parents participated in the groups. Significant themes included issues about teens' control of their own healthcare; enthusiasm about the use of a patient portal to access their providers, seek health information, and make appointments; and concerns about confidentiality. In summary, there was considerable support among teens and parents for a patient portal as well as concerns about confidentiality. The teen portal affords an opportunity to negotiate issues of confidentiality.

Portal hypertensiv gastropati

DEFF Research Database (Denmark)

Brinch, K; Møller, S; Henriksen, Jens Henrik Sahl

1995-01-01

Portal hypertensive gastropathy (PHG) as defined by congestive changes in the gastric mucosa owing to increased portal pressure, was first described about ten years ago. Whereas definition and grading of severity are still under debate, there is general agreement that PHG is a new clinical entity....... PHG is present in 50-80% of patients with liver cirrhosis. PHG is a major cause of upper gastrointestinal bleeding in patients with portal hypertension (25-90% depending on severity). Presence of portal hypertension is a prerequisite for the development of PHG, and reduction of portal pressure...

A comparison of field-only electronic portal imaging hard copies with double exposure port films in radiation therapy treatment setup confirmation to determine its clinical application in a radiotherapy center

International Nuclear Information System (INIS)

Hatherly, Kay; Smylie, Josephine; Rodger, Alan

1999-01-01

Purpose: To determine in which treatment sites field-only hard copy electronic portal images (EPI) captured during a treatment exposure could replace traditional double exposed port films in a busy radiation oncology department. Methods and Materials: The three linear accelerators in the William Buckland Radiotherapy Centre (WBRC) at the Alfred Hospital in Melbourne are each equipped with an electronic portal imaging device (EPID). These devices can be used daily on all patients where the treatment fields are within the size constraint of the cassette, for example, less than 25 x 25 cm. Port films using radiographic film in hard cassettes were previously considered the standard method of field placement verification. After the radiation therapists were trained in all program aspects of capturing, enhancing, and producing hard copies of EPIs, a study was developed to evaluate the possibility of replacing port films with EPI hard copies within the established departmental procedures. Comparison of EPI hard copy with the simulator film and the port film of the same field was carried out by the radiation oncologist specialists. Seventy-eight comparison sets were generated and grouped into seven anatomical regions for evaluation by the radiation oncologist specialist responsible for each particular region. The outcome decision was the preferred imaging option. Where no preference was stated, EPI became the modality of choice, as it increased the efficiency of work practice. Results: The results indicate that field-only EPI can be considered to be at least as clinically useful for treatment verification in the following sites: breast, chest, hip, spine, and large pelvic fields. Port films using a standard, double exposure technique were considered necessary for partial brain fields, small pelvis fields, extremities, and radical head and neck fields. Conclusion: The quality of field-only images captured using an EPID has been favorably assessed to be equivalent to, or an

Rare Disease Video Portal

OpenAIRE

Sánchez Bocanegra, Carlos Luis

2011-01-01

Rare Disease Video Portal (RD Video) is a portal web where contains videos from Youtube including all details from 12 channels of Youtube. Rare Disease Video Portal (RD Video) es un portal web que contiene los vídeos de Youtube incluyendo todos los detalles de 12 canales de Youtube. Rare Disease Video Portal (RD Video) és un portal web que conté els vídeos de Youtube i que inclou tots els detalls de 12 Canals de Youtube.

Customizable Scientific Web Portal for Fusion Research

Energy Technology Data Exchange (ETDEWEB)

Abla, G; Kim, E; Schissel, D; Flannagan, S [General Atomics, San Diego (United States)

2009-07-01

The Web browser has become one of the major application interfaces for remotely participating in magnetic fusion experiments. Recently in other areas, web portals have begun to be deployed. These portals are used to present very diverse sources of information in a unified way. While a web portal has several benefits over other software interfaces, such as providing single point of access for multiple computational services, and eliminating the need for client software installation, the design and development of a web portal has unique challenges. One of the challenges is that a web portal needs to be fast and interactive despite a high volume of tools and information that it presents. Another challenge is the visual output on the web portal often is overwhelming due to the high volume of data generated by complex scientific instruments and experiments; therefore the applications and information should be customizable depending on the needs of users. An appropriate software architecture and web technologies can meet these problems. A web-portal has been designed to support the experimental activities of DIII-D researchers worldwide. It utilizes a multi-tier software architecture, and web 2.0 technologies, such as AJAX, Django, and Memcached, to develop a highly interactive and customizable user interface. It offers a customizable interface with personalized page layouts and list of services for users to select. The users can create a unique personalized working environment to fit their own needs and interests. Customizable services are: real-time experiment status monitoring, diagnostic data access, interactive data visualization. The web-portal also supports interactive collaborations by providing collaborative logbook, shared visualization and online instant message services. Furthermore, the web portal will provide a mechanism to allow users to create their own applications on the web portal as well as bridging capabilities to external applications such as

Knowledge portal: a tool to capture university requirements

Science.gov (United States)

Mansourvar, Marjan; Binti Mohd Yasin, Norizan

2011-10-01

New technologies, especially, the Internet have made a huge impact on knowledge management and information dissemination in education. The web portal as a knowledge management system is very popular topics in many organizations including universities. Generally, a web portal defines as a gateway to online network accessible resources through the intranet, extranet or Internet. This study develops a knowledge portal for the students in the Faculty of Computer Science and Information Technology (FCSIT), University of Malaya (UM). The goals of this portal are to provide information for the students to help them to choose the right courses and major that are relevant to their intended future jobs or career in IT. A quantitative approach used as the selected method for this research. Quantitative method provides an easy and useful way to collect data from a large sample population.

Walter Reed Army Medical Center's Internet-based electronic health portal.

Science.gov (United States)

Abbott, Kevin C; Boocks, Carl E; Sun, Zhengyi; Boal, Thomas R; Poropatich, Ronald K

2003-12-01

Use of the World Wide Web (WWW) and electronic media to facilitate medical care has been the subject of many reports in the popular press. However, few reports have documented the results of implementing electronic health portals for essential medical tasks, such as prescription refills and appointments. At Walter Reed Army Medical Center, "Search & Learn" medical information, Internet-based prescription refills and patient appointments were established in January 2001. A multiphase retrospective analysis was conducted to determine the use of the "Search & Learn" medical information and the relative number of prescription refills and appointments conducted via the WWW compared with conventional methods. From January 2001 to May 2002, there were 34,741 refills and 819 appointments made over the Internet compared with 2,275,112 refills and approximately 500,000 appointments made conventionally. WWW activity accounted for 1.52% of refills and 0.16% of appointments. There was a steady increase in this percentage over the time of the analysis. In April of 2002, the monthly average of online refills had risen to 4.57% and online appointments were at 0.27%. Online refills were projected to account for 10% of all prescriptions in 2 years. The "Search & Learn" medical information portion of our web site received 147,429 unique visits during this same time frame, which was an average of 326 visitors per day. WWW-based methods of conducting essential medical tasks accounted for a small but rapidly increasing percentage of total activity at Walter Reed Army Medical Center. Subsequent phases of analysis will assess demographic and geographic factors and aid in the design of future systems to increase use of the Internet-based systems.

Treatment of portal hypertension caused by benign main portal vein stenosis with endovascular stent

International Nuclear Information System (INIS)

Huang Mingsheng; Shan Hong; Jiang Zaibo; Guan Shouhai; Zhu Kangshun; Li Zhengran; Zhou Yubin; He Bingjun

2004-01-01

Objective: To evaluate the value of endovascular stent in the treatment of portal hypertension caused by benign main portal vein stenosis. Methods: Portal vein stents were implanted in 6 patients with benign main portal vein stenosis (inflammatory stenosis in 3 cases, postprocedure of liver transplantation in another 3 cases). The change of portal vein pressure, the patency of portal vein, relative clinical symptoms, complications, and survival were evaluated. Results: Six metallic stents were successfully placed across the portal vein stenotic or obstructive lesions in all 6 patients. Mean portal venous pressure decreased significantly after stent implantation from (37.3 ± 4.7) cm H 2 O (1 cm H 2 O=0.098 kPa) to (18.0 ± 1.9) cm H 2 O (P<0.001). The portal blood flow was restored, and the symptoms caused by portal hypertension were eliminated. There was no severe procedure-related complication. Follow-up time was from 5 to 36 months. The portal vein remained patent during the follow-up. All patients survived except one patient who died of other complications of liver transplantation. Conclusion: Percutaneous portal vein stent placement for the treatment of the benign main portal vein stenosis is safe and effective. (authors)

Development of a one-stop beam verification system using electronic portal imaging devices for routine quality assurance

International Nuclear Information System (INIS)

Lim, Sangwook; Ma, Sun Young; Jeung, Tae Sig; Yi, Byong Yong; Lee, Sang Hoon; Lee, Suk; Cho, Sam Ju; Choi, Jinho

2012-01-01

In this study, a computer-based system for routine quality assurance (QA) of a linear accelerator (linac) was developed by using the dosimetric properties of an amorphous silicon electronic portal imaging device (EPID). An acrylic template phantom was designed such that it could be placed on the EPID and be aligned with the light field of the collimator. After irradiation, portal images obtained from the EPID were transferred in DICOM format to a computer and analyzed using a program we developed. The symmetry, flatness, field size, and congruence of the light and radiation fields of the photon beams from the linac were verified simultaneously. To validate the QA system, the ion chamber and film (X-Omat V2; Kodak, New York, NY) measurements were compared with the EPID measurements obtained in this study. The EPID measurements agreed with the film measurements. Parameters for beams with energies of 6 MV and 15 MV were obtained daily for 1 month using this system. It was found that our QA tool using EPID could substitute for the film test, which is a time-consuming method for routine QA assessment.

Development of a one-stop beam verification system using electronic portal imaging devices for routine quality assurance

Energy Technology Data Exchange (ETDEWEB)

Lim, Sangwook, E-mail: medicalphysics@hotmail.com [Department of Radiation Oncology, Kosin University College of Medicine, Seo-gu, Busan (Korea, Republic of); Ma, Sun Young; Jeung, Tae Sig [Department of Radiation Oncology, Kosin University College of Medicine, Seo-gu, Busan (Korea, Republic of); Yi, Byong Yong [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD (United States); Lee, Sang Hoon [Department of Radiation Oncology, Cheil General Hospital and Women' s Healthcare Center, Kwandong University College of Medicine, Jung-gu, Seoul (Korea, Republic of); Lee, Suk [Department of Radiation Oncology, College of Medicine, Korea University, Seongbuk-gu, Seoul (Korea, Republic of); Cho, Sam Ju [Department of Radiation Oncology, Eulji University School of Medicine, Eulji General Hospital, Nowon-gu, Seoul (Korea, Republic of); Choi, Jinho [Department of Radiation Oncology, Gachon University of Medicine and Science, Namdong-gu, Incheon (Korea, Republic of)

2012-10-01

In this study, a computer-based system for routine quality assurance (QA) of a linear accelerator (linac) was developed by using the dosimetric properties of an amorphous silicon electronic portal imaging device (EPID). An acrylic template phantom was designed such that it could be placed on the EPID and be aligned with the light field of the collimator. After irradiation, portal images obtained from the EPID were transferred in DICOM format to a computer and analyzed using a program we developed. The symmetry, flatness, field size, and congruence of the light and radiation fields of the photon beams from the linac were verified simultaneously. To validate the QA system, the ion chamber and film (X-Omat V2; Kodak, New York, NY) measurements were compared with the EPID measurements obtained in this study. The EPID measurements agreed with the film measurements. Parameters for beams with energies of 6 MV and 15 MV were obtained daily for 1 month using this system. It was found that our QA tool using EPID could substitute for the film test, which is a time-consuming method for routine QA assessment.

Quality control of portal imaging with PTW EPID QC PHANTOM registered

International Nuclear Information System (INIS)

Pesznyak, Csilla; Kiraly, Reka; Polgar, Istvan; Zarand, Pal; Mayer, Arpad; Fekete, Gabor; Mozes, Arpad; Kiss, Balazs

2009-01-01

Purpose: quality assurance (QA) and quality control (QC) of different electronic portal imaging devices (EPID) and portal images with the PTW EPID QC PHANTOM registered . Material and methods: characteristic properties of images of different file formats were measured on Siemens OptiVue500aSi registered , Siemens BeamView Plus registered , Elekta iView registered , and Varian PortalVision trademark and analyzed with the epidSoft registered 2.0 program in four radiation therapy centers. The portal images were taken with Kodak X-OMAT V registered and the Kodak Portal Localisation ReadyPack registered films and evaluated with the same program. Results: the optimal exposition both for EPIDs and portal films of different kind was determined. For double exposition, the 2+1 MU values can be recommended in the case of Siemens OptiVue500aSi registered , Elekta iView registered and Kodak Portal Localisation ReadyPack registered films, while for Siemens BeamView Plus registered , Varian PortalVision trademark and Kodak X-OMAT V registered film 7+7 MU is recommended. Conclusion: the PTW EPID QC PHANTOM registered can be used not only for amorphous silicon EPIDs but also for images taken with a video-based system or by using an ionization chamber matrix or for portal film. For analysis of QC tests, a standardized format (used at the acceptance test) should be applied, as the results are dependent on the file format used. (orig.)

Segmental hepatic artery at hepatic hilar area. Analysis by 3 dimensional integrated image of artery, portal vein and bile duct

Energy Technology Data Exchange (ETDEWEB)

Sakai, Hisamune; Okuda, Kouji; Yoshida, Jun; Kinoshita, Hisafumi; Aoyagi, Shigeaki [Kurume Univ., School of Medicine, Kurume, Fukuoka (Japan)

2006-11-15

Multiple individual variations in running and bifurcation of the hepatic artery, biliary duct and portal vein are known in hepatic hilar area. This paper describes the examination of such arterial variations by integrating the 3D images of those vessels obtained by multidetector-row CT (MDCT). Subjects are findings from 64 patients with cholangiocarcinoma, hepatocarcinoma or cholelithiasis. MDCT dynamic scanning, and percutaneous transhepatic biliary drainage-CT and/or drip infusion cholangiography-CT with the intravenous iopamidol and/or iotroxate megulumin, were done with GE LightSpeed Ultra 16 slice type equipment to compose the 3D images. Arterial variants of the bifurcation in the right and left lobe were found to be 18 cases/62 (29%) and 13/64 (20%), respectively. The left artery running at right side of portal venous umbilical region was seen in 9/64 (14%) and right artery running ''northward'', in 9/62 (14%). Previous realization of such individual 3D arterial variations as above is necessary for the precise microsurgery of the hilar area to preserve the essential vessel. (T.I.)

Segmental hepatic artery at hepatic hilar area. Analysis by 3 dimensional integrated image of artery, portal vein and bile duct

International Nuclear Information System (INIS)

Sakai, Hisamune; Okuda, Kouji; Yoshida, Jun; Kinoshita, Hisafumi; Aoyagi, Shigeaki

2006-01-01

Multiple individual variations in running and bifurcation of the hepatic artery, biliary duct and portal vein are known in hepatic hilar area. This paper describes the examination of such arterial variations by integrating the 3D images of those vessels obtained by multidetector-row CT (MDCT). Subjects are findings from 64 patients with cholangiocarcinoma, hepatocarcinoma or cholelithiasis. MDCT dynamic scanning, and percutaneous transhepatic biliary drainage-CT and/or drip infusion cholangiography-CT with the intravenous iopamidol and/or iotroxate megulumin, were done with GE LightSpeed Ultra 16 slice type equipment to compose the 3D images. Arterial variants of the bifurcation in the right and left lobe were found to be 18 cases/62 (29%) and 13/64 (20%), respectively. The left artery running at right side of portal venous umbilical region was seen in 9/64 (14%) and right artery running ''northward'', in 9/62 (14%). Previous realization of such individual 3D arterial variations as above is necessary for the precise microsurgery of the hilar area to preserve the essential vessel. (T.I.)

MyWelch: building an information portal system in a medical library environment.

Science.gov (United States)

Zhang, Dongming; Zambrowicz, Caroline; Zhou, Hong; Roderer, Nancy

2003-01-01

MyWelch is a medical library portal system that users can use to create customized web sites that reflect their research needs and personal interests. In the MyWelch environment, faculty and students are empowered to take a greater role in identifying their needs and determining their requirements in the electronic environment. The portal system also facilitates interaction among library users and staff.

Highly Flexible and High-Performance Complementary Inverters of Large-Area Transition Metal Dichalcogenide Monolayers

KAUST Repository

Pu, Jiang

2016-03-23

Complementary inverters constructed from large-area monolayers of WSe2 and MoS2 achieve excellent logic swings and yield an extremely high gain, large total noise margin, low power consumption, and good switching speed. Moreover, the WSe2 complementary-like inverters built on plastic substrates exhibit high mechanical stability. The results provide a path toward large-area flexible electronics. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

The provider perspective: investigating the effect of the Electronic Patient-Reported Outcome (ePRO) mobile application and portal on primary care provider workflow.

Science.gov (United States)

Hans, Parminder K; Gray, Carolyn Steele; Gill, Ashlinder; Tiessen, James

2018-03-01

Aim This qualitative study investigates how the Electronic Patient-Reported Outcome (ePRO) mobile application and portal system, designed to capture patient-reported measures to support self-management, affected primary care provider workflows. The Canadian health system is facing an ageing population that is living with chronic disease. Disruptive innovations like mobile health technologies can help to support health system transformation needed to better meet the multifaceted needs of the complex care patient. However, there are challenges with implementing these technologies in primary care settings, in particular the effect on primary care provider workflows. Over a six-week period interdisciplinary primary care providers (n=6) and their complex care patients (n=12), used the ePRO mobile application and portal to collaboratively goal-set, manage care plans, and support self-management using patient-reported measures. Secondary thematic analysis of focus groups, training sessions, and issue tracker reports captured user experiences at a Toronto area Family Health Team from October 2014 to January 2015. Findings Key issues raised by providers included: liability concerns associated with remote monitoring, increased documentation activities due to a lack of interoperability between the app and the electronic patient record, increased provider anxiety with regard to the potential for the app to disrupt and infringe upon appointment time, and increased demands for patient engagement. Primary care providers reported the app helped to focus care plans and to begin a collaborative conversation on goal-setting. However, throughout our investigation we found a high level of provider resistance evidenced by consistent attempts to shift the app towards fitting with existing workflows rather than adapting much of their behaviour. As health systems seek innovative and disruptive models to better serve this complex patient population, provider change resistance will need to

Prostate position relative to pelvic bony anatomy based on intraprostatic gold markers and electronic portal imaging

International Nuclear Information System (INIS)

Schallenkamp, John M.; Herman, Michael G.; Kruse, Jon J.; Pisansky, Thomas M.

2005-01-01

Purpose: To describe the relative positions and motions of the prostate, pelvic bony anatomy, and intraprostatic gold fiducial markers during daily electronic portal localization of the prostate. Methods and Materials: Twenty prostate cancer patients were treated supine with definitive external radiotherapy according to an on-line target localization protocol using three or four intraprostatic gold fiducial markers and an electronic portal imaging device. Daily pretherapy and through-treatment electronic portal images (EPIs) were obtained for each of four treatment fields. The patients' pelvic bony anatomy, intraprostatic gold markers, and a best visual match to the target (i.e., prostate) were identified on simulation digitally reconstructed radiographs and during daily treatment setup and delivery. These data provided quantitative inter- and intrafractional analysis of prostate motion, its position relative to the bony anatomy, and the individual intraprostatic fiducial markers. Treatment planning margins, with and without on-line localization, were subsequently compared. Results: A total of 22,266 data points were obtained from daily pretherapy and through-treatment EPIs. The pretherapy three-dimensional (3D) average displacement of the fiducial markers, as a surrogate for the prostate, was 5.6 mm, which improved to 2.8 mm after use of the localization protocol. The bony anatomy 3D average displacement was 4.4 mm both before and after localization to the prostate (p = 0.46). Along the superior-inferior (SI), anterior-posterior (AP), and right-left (RL) axes, the average prostate displacement improved from 2.5, 3.7, and 1.9 mm, respectively, before localization to 1.4, 1.6, and 1.1 mm after (all p < 0.001). The pretherapy to through-treatment position of the bony landmarks worsened from 1.7 to 2.5 mm (p < 0.001) in the SI axis, remained statistically unchanged at 2.8 mm (p = 0.39) in the AP axis, and improved from 2.0 to 1.2 mm in the RL axis (p < 0.001). There

Process Simulation and Characterization of Substrate Engineered Silicon Thin Film Transistor for Display Sensors and Large Area Electronics

International Nuclear Information System (INIS)

Hashmi, S M; Ahmed, S

2013-01-01

Design, simulation, fabrication and post-process qualification of substrate-engineered Thin Film Transistors (TFTs) are carried out to suggest an alternate manufacturing process step focused on display sensors and large area electronics applications. Damage created by ion implantation of Helium and Silicon ions into single-crystalline n-type silicon substrate provides an alternate route to create an amorphized region responsible for the fabrication of TFT structures with controllable and application-specific output parameters. The post-process qualification of starting material and full-cycle devices using Rutherford Backscattering Spectrometry (RBS) and Proton or Particle induced X-ray Emission (PIXE) techniques also provide an insight to optimize the process protocols as well as their applicability in the manufacturing cycle

Uniformity studies in large area triple-GEM based detectors

Energy Technology Data Exchange (ETDEWEB)

Akl, M. Abi [Science Program, Texas A& M University at Qatar, PO Box 23874, Doha (Qatar); Bouhali, O., E-mail: othmane.bouhali@qatar.tamu.edu [Science Program, Texas A& M University at Qatar, PO Box 23874, Doha (Qatar); Qatar Computing Research Institute, Hamad Bin Khalifa University, PO Box 5825, Doha (Qatar); Castaneda, A.; Maghrbi, Y.; Mohamed, T. [Science Program, Texas A& M University at Qatar, PO Box 23874, Doha (Qatar)

2016-10-01

Gas Electron Multiplier (GEM) based detectors have been used in many applications since their introduction in 1997. Large areas, e.g. exceeding 30×30 cm{sup 2}, of GEM detectors are foreseen in future experiments which puts stringent requirements on the uniformity of response across the detection area. We investigate the effect of small variations of several parameters that could affect the uniformity. Parameters such as the anode pitch, the gas gap, the size and the shape of the holes are investigated. Simulation results are presented and compared to previous experimental data.

Portal vein thrombosis; risk factors, clinical presentation and treatment

DEFF Research Database (Denmark)

Sogaard, Kirstine K; Astrup, Lone B; Vilstrup, Hendrik

2007-01-01

and treatment of portal vein thrombosis in a single-centre. METHODS: Sixty-seven patients were identified in the electronic records from 1992 to 2005. All data were obtained from the patient records. RESULTS: One or more risk factors (e.g. prothrombotic disorder or abdominal inflammation) were present in 87......BACKGROUND: Portal vein thrombosis (PVT) is increasingly frequently being diagnosed, but systematic descriptions of the natural history and clinical handling of the condition are sparse. The aim of this retrospective study was to describe risk factors, clinical presentation, complications...

The feasible study of vasodilators in portal vein targeting infusion for treating portal hypertension

International Nuclear Information System (INIS)

Wu Hanping; Liang Huiming; Zheng Chuansheng; Feng Gansheng

2002-01-01

Objective: To find out the ideal portal vein tar getting injection routes for portal hypertension treatment. Methods: 28 cirrhotic rat models with portal hypertension induced by CCl 4 were divided into 4 groups: inferior caval vein injection group, portal vein injection group, hepatic artery injection group, spleen injection group. The changes in portal vein pressure (PVP), inferior caval vein pressure (ICVP), mean artery pressure (MAP) and heart rate (HR) were monitored before and after prazosin injection. Results: After intra-portal, intra-hepatic arterial or spleen injection of prazosin, larger decrease in PVP and lesser effects on MAP than intravenous injection had been induced. The effect on HR showed no difference among these four groups. Conclusions: Hepatic artery and spleen prazosin administration have the same advantages on treatment of portal hypertension as those of intra-portal infusion, that is the greater decrease on portal vein pressure, the lesser effects on systemic hemodynamics. Vasodilation drugs for hepatic artery infusion through percutaneous port catheter system by hepatic artery implantation would be an ideal method for portal hypertension treatment

{100} or 45.degree.-rotated {100}, semiconductor-based, large-area, flexible, electronic devices

Science.gov (United States)

Goyal, Amit [Knoxville, TN

2012-05-15

Novel articles and methods to fabricate the same resulting in flexible, {100} or 45.degree.-rotated {100} oriented, semiconductor-based, electronic devices are disclosed. Potential applications of resulting articles are in areas of photovoltaic devices, flat-panel displays, thermophotovoltaic devices, ferroelectric devices, light emitting diode devices, computer hard disc drive devices, magnetoresistance based devices, photoluminescence based devices, non-volatile memory devices, dielectric devices, thermoelectric devices and quantum dot laser devices.

Intrahepatic portal-hepatic venous shunt diagnosed by ultrasonography and computed tomography

International Nuclear Information System (INIS)

Shinagawa, Takashi; Iino, Yasuo; Ukaji, Haruyasu; Ishizuka, Masaharu

1986-01-01

Two cases of intrahepatic portal-hepatic venous shunt found by ultrasonography and computed tomography are reported. The first case came to the hospital because of hematuria. A large shunt between the portal vein and the hepatic vein was demonstrated by ultrasonography done for screening, and confirmed by percutaneous transhepatic portography (PTP). The second case was admitted because of cholelithiasis. Computed tomography with contrast enhancement revealed a dilated portal vein in the upper portion of the right lobe. It was subsequently shown by PTP to be a portal-hepatic venous shunt. Portal vein pressure and histological finding of the liver were normal in both cases. The etiology of the shunt was thought to be congenital in these cases for lack of liver disease, portal hypertension and history of trauma. Both cases had no history of hepatic encephalopathy and did not show any symptom attributable to the shunt. (author)

Portal vein thrombosis.

Science.gov (United States)

Chawla, Yogesh K; Bodh, Vijay

2015-03-01

Portal vein thrombosis is an important cause of portal hypertension. PVT occurs in association with cirrhosis or as a result of malignant invasion by hepatocellular carcinoma or even in the absence of associated liver disease. With the current research into its genesis, majority now have an underlying prothrombotic state detectable. Endothelial activation and stagnant portal blood flow also contribute to formation of the thrombus. Acute non-cirrhotic PVT, chronic PVT (EHPVO), and portal vein thrombosis in cirrhosis are the three main variants of portal vein thrombosis with varying etiological factors and variability in presentation and management. Procoagulant state should be actively investigated. Anticoagulation is the mainstay of therapy for acute non-cirrhotic PVT, with supporting evidence for its use in cirrhotic population as well. Chronic PVT (EHPVO) on the other hand requires the management of portal hypertension as such and with role for anticoagulation in the setting of underlying prothrombotic state, however data is awaited in those with no underlying prothrombotic states. TIPS and liver transplant may be feasible even in the setting of PVT however proper selection of candidates and type of surgery is warranted. Thrombolysis and thrombectomy have some role. TARE is a new modality for management of HCC with portal vein invasion.

A heuristic approach to edge detection in on-line portal imaging

International Nuclear Information System (INIS)

McGee, Kiaran P.; Schultheiss, Timothy E.; Martin, Eric E.

1995-01-01

Purpose: Portal field edge detection is an essential component of several postprocessing techniques used in on-line portal imaging, including field shape verification, selective contrast enhancement, and treatment setup error detection. Currently edge detection of successive fractions in a multifraction portal image series involves the repetitive application of the same algorithm. As the number of changes in the field is small compared to the total number of fractions, standard edge detection algorithms essentially recalculate the same field shape numerous times. A heuristic approach to portal edge detection has been developed that takes advantage of the relatively few changes in the portal field shape throughout a fractionation series. Methods and Materials: The routine applies a standard edge detection routine to calculate an initial field edge and saves the edge information. Subsequent fractions are processed by applying an edge detection operator over a small region about each point of the previously defined contour, to determine any shifts in the field shape in the new image. Failure of this edge check indicates that a significant change in the field edge has occurred, and the original edge detection routine is applied to the image. Otherwise the modified edge contour is used to define the new edge. Results: Two hundred and eighty-one portal images collected from an electronic portal imaging device were processed by the edge detection routine. The algorithm accurately calculated each portal field edge, as well as reducing processing time in subsequent fractions of an individual portal field by a factor of up to 14. Conclusions: The heuristic edge detection routine is an accurate and fast method for calculating portal field edges and determining field edge setup errors

Macronodular hepatic tuberculosis associated with portal vein thrombosis and portal hypertension

International Nuclear Information System (INIS)

Venkatesh, S.K.; Tan, L.K.A.; Siew, E.P.Y.; Putti, T.C.

2005-01-01

Tuberculosis (TB) of the liver is usually associated with miliary spread. Macronodular TB of the liver is rare. A case of macronodular TB of the liver in a 31-year-old woman causing portal vein thrombosis and portal hypertension is presented. Ultrasound and CT appearances are described. There was coexistent ileo-caecal TB with extensive mesenteric and retroperitoneal lymphadenopathy. Macronodular TB should be considered in the differential diagnosis when a patient presents with multiple calcified masses in the liver with portal vein thrombosis and portal hypertension. Copyright (2005) Blackwell Science Pty Ltd

Two-dimensional exit dosimetry using a liquid-filled electronic portal imaging device and a convolution model

International Nuclear Information System (INIS)

Boellaard, Ronald; Herk, Marcel van; Uiterwaal, Hans; Mijnheer, Ben

1997-01-01

Background and purpose: To determine the accuracy of two-dimensional exit dose measurements with an electronic portal imaging device, EPID, using a convolution model for a variety of clinically relevant situations. Materials and methods: Exit doses were derived from portal dose images, obtained with a liquid-filled EPID at distances of 50 cm or more behind the patient, by using a convolution model. The resulting on- and off-axis exit dose values were first compared with ionization chamber exit dose measurements for homogeneous and inhomogeneous phantoms in open and wedged 4,8 and 18 MV photon beams. The accuracy of the EPID exit dose measurements was then determined for a number of anthropomorphic phantoms (lung and larynx) irradiated under clinical conditions and for a few patients treated in an 8 MV beam. The latter results were compared with in vivo exit dose measurements using diodes. Results: The exit dose can be determined from portal images with an accuracy of 1.2% (1 SD) compared with ionization chamber measurements for open beams and homogeneous phantoms at all tested beam qualities. In the presence of wedges and for inhomogeneous phantoms the average relative accuracy slightly deteriorated to 1.7% (1 SD). For lung phantoms in a 4 MV beam a similar accuracy was obtained after refinement of our convolution model, which requires knowledge of the patient contour. Differences between diode and EPID exit dose measurements for an anthropomorphic lung phantom in an 8 MV beam were 2.5% at most, with an average agreement within 1% (1 SD). For larynx phantoms in a 4 MV beam exit doses obtained with an ionization chamber and EPID agreed within 1.5% (1 SD). Finally, exit doses in a few patients irradiated in an 8 MV beam could be determined with the EPID with an accuracy of 1.1% (1 SD) relative to exit dose measurements using diodes. Conclusions: Portal images, obtained with our EPID and analyzed with our convolution model, can be used to determine the exit dose

A Look at Success for Data Portals (Invited)

Science.gov (United States)

White, C. E.

2013-12-01

As a member of Esri's Geoportal Server team for the past six years, I have been involved in hundreds of customer portal, geoportal, and spatial data infrastructure implementations. Our team's goal for each implementation is - of course- for it to be successful. A successful data portal can be defined by a number of indicators. The foremost measure of success is that the target end users are able to easily find and access data that meets their needs. Other indicators are effectiveness of the user interface, interoperability mechanisms to enhance discoverability and usability across contexts, compliance with data sharing mandates, extendibility/portability of the system as technology evolves, and staff expertise to maintain the system. Further, some data portals have not only been successful by these measures but have also challenged and expanded the state of the art in the areas of discovery, access, and managing data. This talk will address models, principles, and best practices for deploying data portals that are successful by these measures, identify examples of excellence in the field, and discuss upcoming advances in portal technology to support scientists in sharing their work.

Noncirrotisk intrahepatisk portal hypertension

DEFF Research Database (Denmark)

Dam Fialla, Annette; Havelund, Troels

2007-01-01

Non-cirrhotic intrahepatic portal hypertension is characterized by portal hypertension in the absence of liver cirrhosis or portal vein thrombosis. The disease is common in the East and rarely seen in the West. Two cases with oesophageal varices are described. The histopathology is heterogeneous...... but includes vascular lesions and portal fibrosis. Patient management follows the current recommendations for variceal bleeding....

Hepatic angiography: Portal hypertension

International Nuclear Information System (INIS)

Oliver, T.W. Jr.; Sones, P.J. Jr.

1985-01-01

Portal hypertension is usually a manifestation of underlying hepatic parenchymal disease, although it may be secondary to portal or hepatic venous thrombosis and rarely to hyperdynamic portal states. Portal hypertension may present as encephalopathy, ascites, jaundice, hepatic failure, or catastrophic upper gastrointestinal hemorrhage. Radiologic investigation should include indirect or direct measurements of portal pressure, assessment of portal venous perfusion, visualization of collaterals, and demonstration of arterial and venous anatomy for potential shunt procedure. Following survival of initial variceal bleeding, the most effective procedure to prevent recurrent hemorrhage is a shunt to decompress the varices. The decision whether to intervene medically or surgically during the acute hemorrhagic episode as well as the type of shunt used to prevent future hemorrhage is the subject of continuing controversy

R2 Water Quality Portal Monitoring Stations

Data.gov (United States)

U.S. Environmental Protection Agency — The Water Quality Data Portal (WQP) provides an easy way to access data stored in various large water quality databases. The WQP provides various input parameters on...

Large area nuclear particle detectors using ET materials

International Nuclear Information System (INIS)

1987-08-01

The purpose of this SBIR Phase 1 feasibility effort was to demonstrate the usefulness of Quantex electron-trapping (ET) materials for spatial detection of nuclear particles over large areas. This demonstration entailed evaluating the prompt visible scintillation as nuclear particles impinged on films of ET materials, and subsequently detecting the nuclear particle impingement information pattern stored in the ET material, by means of the visible-wavelength luminescence produced by near-infrared interrogation. Readily useful levels of scintillation and luminescence outputs are demonstrated

Real-time Cherenkov emission portal imaging during CyberKnife® radiotherapy

International Nuclear Information System (INIS)

Roussakis, Yiannis; Mason, Suzannah; Dehghani, Hamid; Zhang, Rongxiao; Heyes, Geoff; Webster, Gareth; Green, Stuart; Pogue, Brian

2015-01-01

The feasibility of real-time portal imaging during radiation therapy, through the Cherenkov emission (CE) effect is investigated via a medical linear accelerator (CyberKnife ® ) irradiating a partially-filled water tank with a 60 mm circular beam. A graticule of lead/plywood and a number of tissue equivalent materials were alternatively placed at the beam entrance face while the induced CE at the exit face was imaged using a gated electron-multiplying-intensified-charged-coupled device (emICCD) for both stationary and dynamic scenarios. This was replicated on an Elekta Synergy ® linear accelerator with portal images acquired using the iViewGT ™ system. Profiles across the acquired portal images were analysed to reveal the potential resolution and contrast limits of this novel CE based portal imaging technique and compared against the current standard. The CE resolution study revealed that using the lead/plywood graticule, separations down to 3.4  ±  0.5 mm can be resolved. A 28 mm thick tissue-equivalent rod with electron density of 1.69 relative to water demonstrated a CE contrast of 15% through air and 14% through water sections, as compared to a corresponding contrast of 19% and 12% using the iViewGT ™ system. For dynamic scenarios, video rate imaging with 30 frames per second was achieved. It is demonstrated that CE-based portal imaging is feasible to identify both stationary and dynamic objects within a CyberKnife ® radiotherapy treatment field. (note)

Trans-anastomotic porto-portal varices in patients with gastrointestinal haemorrhage

International Nuclear Information System (INIS)

Mitchell, A.W.M.; Jackson, J.E.

2000-01-01

AIM: Porto-portal varices are commonly seen in patients with segmental extra-hepatic portal hypertension and develop to provide a collateral circulation around an area of portal venous obstruction. It is not well recognized that such communications may also develop across surgical anastomoses and be the source of gastrointestinal haemorrhage. The possible mode of development of such communications has not been previously discussed. MATERIALS AND METHODS: Over a 3-year period between 1995 and 1998, porto-portal varices were demonstrated across surgical anastomoses in four patients who were referred for the investigation of acute (two), acute-on-chronic (one) and chronic gastrointestinal bleeding (one). Their medical notes and the findings at angiography were reviewed. RESULTS: Three patients had segmental portal hypertension due to extra-hepatic portal vein (one) or superior mesenteric vein (two) stenosis/occlusion. One patient had mild portal hypertension due to hepatic fibrosis secondary to congenital biliary atresia. At angiography all patients were shown to have varices crossing previous surgical anastomoses. These varices were presumed to be the cause of bleeding in three of the four patients; the site of bleeding in the fourth individual was not determined. CONCLUSIONS: Trans-anastomotic porto-portal varices are rare. They develop in the presence of extra-hepatic portal hypertension and presumably arise within peri-anastomotic inflammatory tissue. Such varices may be difficult to manage and their prognosis is poor when bleeding occurs. Mitchell, A.W.M., Jackson, J.E. (2000)

Mobile Portal Implementation Strategy

DEFF Research Database (Denmark)

Gao, Ping; Damsgaard, Jan

2005-01-01

Mobile portal plays an important role in mobile commerce market. Current literature focuses on static analysis on the value chain of mobile portals. This article provides a dynamic perspective on mobile portal strategy. Drawing upon network economics, we describe mobile portal implementation...... as a fourphase process. In different phase, a portal provider has various challenges to overcome and adopt diverse strategies, and correspondingly the regulator has different foci. The conceptual framework proposed in this article offers a basis for further analyses on the market dynamics of mobile commerce......, and can be generalized to studying other networked technologies...

Hepatic venography in noncirrhotic idiopathic portal hypertension: comparison with cirrhosis of the liver

International Nuclear Information System (INIS)

Futagawa, S.; Fukazawa, M.; Musha, H.

1981-01-01

Free and wedged hepatic venography were carried out in 37 patients with idiopathic portal hypertension (IPH) and the findings compared with those in 88 patients with cirrhosis of the liver. Characteristic changes in IPH included frequent vein-to-vein anastomoses, narrower angles between large veins and their tributaries, smooth and wavy middle-sized to large branches (giving a general ''weeping willow'' appearance), homogeneous sinusoidal filling, and minimal to absent filling of the portal venous system on wedged retrograde portography. In cirrhosis, by contrast, changes included rare vein-to-vein anastomoses, wide angles between veins and tributaries, irregular stenoses of large veins and branches at various levels, spotty sinusoidal filling, and frequent retrograde flow in the portal venous system. Hepatic venography is helpful in differentiating IPH from cirrhosis

Roadside Tracker Portal-less Portal Monitor

Energy Technology Data Exchange (ETDEWEB)

Ziock, Klaus-Peter [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Cheriyadat, Anil M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bradley, Eric Craig [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Cunningham, Mark F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Fabris, Lorenzo [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Goddard, Jr, James Samuel [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hornback, Donald Eric [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Karnowski, Thomas Paul [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kerekes, Ryan A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Newby, Jason [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2013-07-01

This report documents the full development cycle of the Roadside Tracker (RST) Portal-less Portal monitor (Fig. 1) funded by DHS DNDO. The project started with development of a proof-of-feasibility proto-type, proceeded through design and construction of a proof-of-concept (POC) prototype, a test-and-evaluation phase, participation in a Limited Use Exercise that included the Standoff Radiation Detections Systems developed under an Advanced Technology Demonstration and concluded with participation in a Characterization Study conducted by DNDO.

Tc-99m-Sn colloid dynamic and static scintigraphic evaluation of patients with portal hypertension

Energy Technology Data Exchange (ETDEWEB)

Kamal, S; Lodhi, T; Qureshi, H; Zuberi, S; Khan, R

1986-04-01

Dynamic scintigraphy of the liver and spleen was performed by injecting Tc-99m-Sl colloid as a bolus in 15 normal controls and 17 patients presenting with portal hypertension. Using a computer, the hepatic and splenic time-activity curves were analyzed. In addition to the Ratio of Area, the Ratio of Integral and Slope of Integral for liver to spleen were also calculated. The Ratio of the Area (L/S) was significantly different in the normal and portal hypertensives (p < 0.001). The Ratios of the Integral and the slope of the Integral were not only significantly different in the normals and portal hypertensives (p < 0.001) but were also significantly different in the cirrhotic and the non-cirrhotic group of portal hypertensives (p < 0.001). In the routine study of liver scintigraphy in cases of portal hypertension, by adding the above mentioned method, the increased information of uptake dynamics seems to be useful for differentiating the cirrhotic and non-cirrhotic groups of portal hypertension.

Tc-99m-Sn colloid dynamic and static scintigraphic evaluation of patients with portal hypertension

International Nuclear Information System (INIS)

Kamal, S.; Lodhi, T.; Qureshi, H.; Zuberi, S.; Khan, R.

1986-01-01

Dynamic scintigraphy of the liver and spleen was performed by injecting Tc-99m-Sl colloid as a bolus in 15 normal controls and 17 patients presenting with portal hypertension. Using a computer, the hepatic and splenic time-activity curves were analyzed. In addition to the Ratio of Area, the Ratio of Integral and Slope of Integral for liver to spleen were also calculated. The Ratio of the Area (L/S) was significantly different in the normal and portal hypertensives (p < 0.001). The Ratios of the Integral and the slope of the Integral were not only significantly different in the normals and portal hypertensives (p < 0.001) but were also significantly different in the cirrhotic and the non-cirrhotic group of portal hypertensives (p < 0.001). In the routine study of liver scintigraphy in cases of portal hypertension, by adding the above mentioned method, the increased information of uptake dynamics seems to be useful for differentiating the cirrhotic and non-cirrhotic groups of portal hypertension. (author)

Quality Control of Mega Voltage Portal Imaging System

International Nuclear Information System (INIS)

Diklic, A.; Dundara Debeljuh, D.; Jurkovic, S.; Smilovic Radojcic, D.; Svabic Kolacio; Kasabasic, M.; Faj, D.

2013-01-01

The Electronic Portal Imaging Device (EPID) is a system used to verify either the correct positioning of the patient during radiotherapy treatment or the linear accelerator beam parameters. The correct position of the patient corresponds to the position at which the patient was scanned at the CT simulator and according to which the therapy plan was made and optimized. Regarding this, besides the advanced treatment planning system and optimized treatment planning techniques, the day-to-day reproduction of simulated conditions is of great importance for the treatment outcome. Therefore, to verify the patient set-up portal imaging should be applied prior to the first treatment session and repeated according to treatment prescriptions during the treatment. In order to achieve full functionality and precision of the EPID, it must be included in radiotherapy Quality Control (QC) programme. The QC of the Mega Voltage portal imaging system was separated in two parts. In the first, the QC of the detector parameters should be performed. For this purpose, the FC2 and QC3 phantoms should be used, along with the Portal Image Processing System program (PIPSpro) package for data analysis. The second part of the QC of the linear accelerator's portal imaging system should include the QC of the CBCT. In this part a set of predefined manufacturer's tests using two different phantoms, one for the geometry calibration and the other for the image quality evaluation, should be performed. Also, the treatment conditions should be simulated using anthropomorphic phantoms and dose distributions for particular EPID protocols should be measured. Procedures for quality control of the portal imaging system developed and implemented at University Hospital Rijeka are presented in this paper.(author)

Knowledge, workflow and electronic document management in the system of the State Nuclear Regulatory Inspectorate of Ukraine. Preparing the platform development and implementation of the Knowledge Portal

International Nuclear Information System (INIS)

Bozhko, S.G.; Shevchenko, Yi.A.; Pecheritsya, O.V.; Singayivs'kij, A.M.

2016-01-01

The previous paper considered the creation of the system for management of nuclear knowledge, workflow and electronic documents (hereinafter called the Knowledge Portal) in the field of safe nuclear energy use. It presented initial steps needed to make an informed decision on the feasibility of implementing the Knowledge Portal and proposed methodological approaches based on practical experience of the State Nuclear Regulatory Inspectorate of Ukraine and the SSTC NRS. Further pre - project activities of the state body, local authorities, enterprises, institutions and organizations irrespective of ownership (hereinafter called the Institution) involve the development and drawing attention to the package of analytical, technical and feasibility documents. In particular, it is recommended to take into account the results of analyzing world trends in the development of information technology, audit status information and telecommunication systems (hereinafter - ITS) of the Institution, detailed strategy for the development of ITS Institution (hereinafter - the Strategy), the concept of the Knowledge Portal (hereinafter - the Concept) and preliminary technical solution The results of review and approval of the Concept and architecture solution by scientific and technical council of the Institution is the basis for the preparation of Ter ms of Reference (hereinafter - TOR) on the development of the Knowledge Portal, forming schedules for the procurement of hardware and software, works on the development and implementation of portal solutions and information security systems

Echographic and hemodynamic parameters in patients with hepatic cirrhosis and portal hypertension

International Nuclear Information System (INIS)

Rikhsieva, L.Eh.; Akhmedzhanova, Sh.Sh.; Myasnik, B.N.; Khodzhibekov, M.Kh.

1989-01-01

The efficiency of combined echoradionuclide investigation for the identification of the severity of portal hypertension and the determination of clear-cut criteria for the differentiation of stages of portal hypertension with reference to functional potentials of renal hemodynamics and systemic circulation at large is demonstrated

Mapping the electrical properties of large-area graphene

Science.gov (United States)

Bøggild, Peter; Mackenzie, David M. A.; Whelan, Patrick R.; Petersen, Dirch H.; Due Buron, Jonas; Zurutuza, Amaia; Gallop, John; Hao, Ling; Jepsen, Peter U.

2017-12-01

The significant progress in terms of fabricating large-area graphene films for transparent electrodes, barriers, electronics, telecommunication and other applications has not yet been accompanied by efficient methods for characterizing the electrical properties of large-area graphene. While in the early prototyping as well as research and development phases, electrical test devices created by conventional lithography have provided adequate insights, this approach is becoming increasingly problematic due to complications such as irreversible damage to the original graphene film, contamination, and a high measurement effort per device. In this topical review, we provide a comprehensive overview of the issues that need to be addressed by any large-area characterisation method for electrical key performance indicators, with emphasis on electrical uniformity and on how this can be used to provide a more accurate analysis of the graphene film. We review and compare three different, but complementary approaches that rely either on fixed contacts (dry laser lithography), movable contacts (micro four point probes) and non-contact (terahertz time-domain spectroscopy) between the probe and the graphene film, all of which have been optimized for maximal throughput and accuracy, and minimal damage to the graphene film. Of these three, the main emphasis is on THz time-domain spectroscopy, which is non-destructive, highly accurate and allows both conductivity, carrier density and carrier mobility to be mapped across arbitrarily large areas at rates that by far exceed any other known method. We also detail how the THz conductivity spectra give insights on the scattering mechanisms, and through that, the microstructure of graphene films subject to different growth and transfer processes. The perspectives for upscaling to realistic production environments are discussed.

Patient portal readiness among postpartum patients in a safety net setting.

Science.gov (United States)

Wieland, Daryl; Gibeau, Anne; Dewey, Caitlin; Roshto, Melanie; Frankel, Hilary

2017-07-05

Maternity patients interact with the healthcare system over an approximately ten-month interval, requiring multiple visits, acquiring pregnancy-specific education, and sharing health information among providers. Many features of a web-based patient portal could help pregnant women manage their interactions with the healthcare system; however, it is unclear whether pregnant women in safety-net settings have the resources, skills or interest required for portal adoption. In this study of postpartum patients in a safety net hospital, we aimed to: (1) determine if patients have the technical resources and skills to access a portal, (2) gain insight into their interest in health information, and (3) identify the perceived utility of portal features and potential barriers to adoption. We developed a structured questionnaire to collect demographics from postpartum patients and measure use of technology and the internet, self-reported literacy, interest in health information, awareness of portal functions, and perceived barriers to use. The questionnaire was administered in person to women in an inpatient setting. Of the 100 participants surveyed, 95% reported routine internet use and 56% used it to search for health information. Most participants had never heard of a patient portal, yet 92% believed that the portal functions were important. The two most appealing functions were to check results and manage appointments. Most participants in this study have the required resources such as a device and familiarity with the internet to access a patient portal including an interest in interacting with a healthcare institution via electronic means. Pregnancy is a critical episode of care where active engagement with the healthcare system can influence outcomes. Healthcare systems and portal developers should consider ways to tailor a portal to address the specific health needs of a maternity population including those in a safety net setting.

Application of backscatter electrons for large area imaging of cavities produced by neutron irradiation

Energy Technology Data Exchange (ETDEWEB)

Pastukhov, V.I. [Joint Stock Company “Institute of Nuclear Materials” (JSC “INM”), Zarechny, Sverdlovsk Region (Russian Federation); Ural Federal University Named After the First President of Russia, B. N. Yeltsyn, Ekaterinburg (Russian Federation); National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation); Averin, S.A.; Panchenko, V.L. [Joint Stock Company “Institute of Nuclear Materials” (JSC “INM”), Zarechny, Sverdlovsk Region (Russian Federation); National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation); Portnykh, I.A. [Joint Stock Company “Institute of Nuclear Materials” (JSC “INM”), Zarechny, Sverdlovsk Region (Russian Federation); Freyer, P.D. [Westinghouse Electric Company, Pittsburgh, PA (United States); Giannuzzi, L.A. [L.A. Giannuzzi & Associates LLC, Fort Myers, FL (United States); Garner, F.A., E-mail: frank.garner@dslextreme.com [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation); Radiation Effects Consulting LLC, Richland, WA (United States); Texas A& M University, College Station, TX (United States)

2016-11-15

It is shown that with proper optimization, backscattered electrons in a scanning electron microscope can produce images of cavity distribution in austenitic steels over a large specimen surface for a depth of ∼500–700 nm, eliminating the need for electropolishing or multiple specimen production. This technique is especially useful for quantifying cavity structures when the specimen is known or suspected to contain very heterogeneous distributions of cavities. Examples are shown for cold-worked EK-164, a very heterogeneously-swelling Russian fast reactor fuel cladding steel and also for AISI 304, a homogeneously-swelling Western steel used for major structural components of light water cooled reactors. This non-destructive overview method of quantifying cavity distribution can be used to direct the location and number of required focused ion beam prepared transmission electron microscopy specimens for examination of either neutron or ion-irradiated specimens. This technique can also be applied in stereo mode to quantify the depth dependence of cavity distributions.

Determining the optimal portal blood volume in a shunt before surgery in extrahepatic portal hypertension

Directory of Open Access Journals (Sweden)

Yurchuk Vladimir A

2016-04-01

Full Text Available The aim of the study: To determine the necessary shunt diameter and assess the optimal portal blood volume in a shunt in children with extrahepatic portal hypertension before the portosystemic shunt surgery. Changes in the liver hemodynamics were studied in 81 children aged from 4 to 7 years with extrahepatic portal hypertension. We established that it is necessary to calculate the shunt diameter and the blood volume in a shunt in patients with extrahepatic portal hypertension before the portosystemic shunt surgery. It allows us to preserve the hepatic portal blood flow and effectively decrease the pressure in the portal system. Portosystemic shunt surgery in patients with extrahepatic portal hypertension performed in accordance with the individualized shunt volume significantly decreases portal pressure, preserves stable hepatic hemodynamics and prevents gastro-esophageal hemorrhage.

Laser Direct Write micro-fabrication of large area electronics on flexible substrates

Science.gov (United States)

Zacharatos, F.; Makrygianni, M.; Geremia, R.; Biver, E.; Karnakis, D.; Leyder, S.; Puerto, D.; Delaporte, P.; Zergioti, I.

2016-06-01

To date, Laser Direct Write (LDW) techniques, such as Laser Induced Forward Transfer (LIFT), selective laser ablation and selective laser sintering of metal nanoparticle (NP) ink layers are receiving growing attention for the printing of uniform and well-defined conductive patterns with resolution down to 10 μm. For flexible substrates in particular, selective laser sintering of such NP patterns has been widely applied, as a low temperature and high resolution process compatible with large area electronics. In this work, LDW of silver NP inks has been carried out on polyethylene-terephthalate (PET), polyethylene-naphthalate (PEN) and polyimide (PI) substrates to achieve low electrical resistivity electrodes. In more detail, high speed short pulsed (picosecond and nanosecond) lasers with repetition rates up to 1 MHz were used to print (LIFT) metal NP inks. We thus achieved uniform and continuous patterns with a minimum feature size of 1 μm and a total footprint larger than 1 cm2. Next, the printed patterns were laser sintered with ns pulses at 532 nm over a wide laser fluence window, resulting in an electrical resistivity of 10 μΩ cm. We carried out spatial beam shaping experiments to achieve a top-hat laser intensity profile and employed selective laser ablation of thin films (thickness on the order of 100 nm) to produce silver micro-electrodes with a resolution on the order of 10 μm and a low line edge roughness. Laser sintering was combined with laser ablation to constitute a fully autonomous micro-patterning technique of metallic micro-features, with a 10 μm resolution and geometrical characteristics tuned for interdigitated electrodes for sensor applications.

Towards molecular electronics with large-area molecular junctions

NARCIS (Netherlands)

Akkerman, HB; Blom, PWM; de Leeuw, DM; de Boer, B

2006-01-01

Electronic transport through single molecules has been studied extensively by academic(1-8) and industrial(9,10) research groups. Discrete tunnel junctions, or molecular diodes, have been reported using scanning probes(11,12), break junctions(13,14), metallic crossbars(6) and nanopores(8,15). For

CT findings of portal vein aneurysm

International Nuclear Information System (INIS)

Yang, Dal Mo; Chang, Mi Son; Yoon, Myung Hwan; Kim, Hak Soo; Kim, Hyung Sik; Chung, Hyo Sun; Chung, Jin Woo

1999-01-01

To describe the CT findings of portal vein aneurysm in eight patients. All patients included in this study (two men and six women) underwent CT examinations between October 1996 and June1998. Of these eight, three were suffering from hepatic disease and portal hypertension. We determined the location, shape, size, and characteristics of the lesions, and the presence or absence of portal vein anomaly. Seven patients had intrahepatic portal vein aneurysm (at the umbilical portion of the left portal vein in five patients, between the transverse and umbilical portion of the left portal vein in one, and at the bifurcation of the anterior and posterior branch of the right portal vein in one), while extrahepatic portal vein aneurysm, at the confluence of the superior mesenteric and splenic vein was found in only one. Lesions were cyst-shaped in seven cases and saccular in one, and showed well-circumscribed, markedly enhanced mass, which communicated with the portal vein and/or gives off major branches. Portal vein anomaly, in which the right anterior segmental portal vein originated from the umbilical portion of the left portal vein, was seen in three patients. In all three, intrahepatic portal vein aneurysm was present at the umbilical portion of the left portal vein, and in one, the umbilical protion of the left portal vein was located to the right of the Cantlic line. CT examination can help reveal portal vein aneurysm by detecting a well-circumscribed, markedly enhanced mass which communicates with the portal vein and/or gives off major branches

Study in rabbits of portal circulation by a radioisotopic method

International Nuclear Information System (INIS)

Maliska, C.

1980-01-01

The development of a precocius - and noninvasive method for the detection of portal circulation alterations by means of time interval measurements between the rectal administration of radiotracers and their detection in liver and head is aimed at. The pertecnetate ( 99 sup(m)Tc)- and iodate ( 131 I) absorption by the terminal large intestine was tested in 22 rabbits. The time iinterval between rectal administration of the radiotracer and its appearance in liver and head was determined in 12 rabbits, by external detection with a scintillation camera. The same parameters were studied in 9 animals submitted to the ligature of the portal vein. Iodate and pertecnetate are absorbed by the terminal large intestine, the pertecnetate absorption being significantly smaller than that of iodate. The pertecnetate distribution volume is smaller than that of iodate; the rectum - liver - and rectum - head time intervals is increased in animals with the ligature of portal vein. Application of the method to larger animals will permit the necessary improvements for its utilization as a precocius - noninvasive - and inocuous test in the evaluation of alteration of the human portal circulation. (Author) [pt

Pediatric portal hypertension

Science.gov (United States)

Vogel, Clarissa Barbon

2017-01-01

Abstract: Pediatric portal hypertension management is a team approach between the patient, the patient's family, the primary caregiver, and specialty providers. Evidence-based practice guidelines have not been established in pediatrics. This article serves as a review for the primary care NP in the management of pediatric portal hypertension, discussing the etiology, pathophysiology, and clinical presentation of pediatric portal hypertension, diagnostic tests, and treatment and management options. PMID:28406835

Patient Portal Use and Blood Pressure Control in Newly Diagnosed Hypertension.

Science.gov (United States)

Manard, William; Scherrer, Jeffrey F; Salas, Joanne; Schneider, F David

2016-01-01

Current evidence that patient portal use improves disease management is inconclusive. Randomized controlled trials have found no benefit of Web-based patient-provider communication for blood pressure (BP) control, but patients from these studies were not selected for uncontrolled hypertension, nor did measures of portal use occur in a real-world setting, as captured in the electronic medical record. This study determined whether patient portal use by patients with treated, incident hypertension was associated with achieving BP control. Between 2008 to 2010, 1571 patients with an incident hypertension diagnosis, ages 21 to >89 years, were identified from an academic medical center primary care patient data registry. Cox proportional hazard models were computed to estimate the association between portal use and incident BP control during follow-up (2011-2015), before and after adjusting for covariates. Covariates included sociodemographics, smoking, obesity and other physical and mental health comorbidities, and volume of health care utilization. After adjusting for age, portal users were more likely than nonusers to achieve BP control (hazard ratio, 1.24; 95% confidence interval, 1.06-1.45). After adjustment for sociodemographics, portal use was no longer associated with BP control (hazard ratio, 0.98; 95% confidence interval, 0.83-1.16). Patient sociodemographic factors, including race, sex, and socioeconomic status, account for the observation that portal use leads to BP control among persons with newly diagnosed hypertension. Further research is warranted to determine whether there are benefits of portal use for other chronic conditions. © Copyright 2016 by the American Board of Family Medicine.

Establishment of a reversible model of prehepatic portal hypertension in rats.

Science.gov (United States)

Zhao, Xin; Dou, Jian; Gao, Qing-Jun

2016-08-01

The aim of the present study was to improve upon the traditional model of pre-hepatic portal hypertension in rats, and simulate the anhepatic phase of orthotopic liver transplantation without veno-venous bypass. A reversible model of portal hypertension was induced by portal vein ligation, with a label ring ligated along the portal vein. A total of 135 male Wistar rats were divided into three groups: i) Normal control (NC) group; ii) portal hypertensive control (PHTC) group; and iii) reperfusion (R) group. In the R group, rats with portal hypertension underwent simultaneous clamping of the portal triad and retrohepatic vena cava for 1 h, followed by removal of the clamps to enable blood reperfusion. Portal venography and portal vein pressure were recorded during the surgery. Arterial oxygen pressure (PaO 2 ), and alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total bilirubin (TBil) levels were determined, and pathological changes of the liver were investigated by immunohistochemical staining. The results demonstrated that, 3 weeks after portal vein ligation, the vein area and the free portal pressures in the PHTC group were significantly increased compared with those in the NC group. The serum ALT and AST levels in the R group at different time points were significantly elevated compared with those in the PHTC group, and reached their maximal levels at 24 h after reperfusion. Furthermore, the PaO 2 at 24 h after reperfusion was significantly decreased. In conclusion, the reversible model of pre-hepatic portal hypertension in rats was successfully established using the introduction of a label ring. This model may be useful for basic research focusing on the anhepatic phase of orthotopic liver transplantation without veno-venous bypass.

A Population-Level Data Analytics Portal for Self-Administered Lifestyle and Mental Health Screening.

Science.gov (United States)

Zhang, Xindi; Warren, Jim; Corter, Arden; Goodyear-Smith, Felicity

2016-01-01

This paper describes development of a prototype data analytics portal for analysis of accumulated screening results from eCHAT (electronic Case-finding and Help Assessment Tool). eCHAT allows individuals to conduct a self-administered lifestyle and mental health screening assessment, with usage to date chiefly in the context of primary care waiting rooms. The intention is for wide roll-out to primary care clinics, including secondary school based clinics, resulting in the accumulation of population-level data. Data from a field trial of eCHAT with sexual health questions tailored to youth were used to support design of a data analytics portal for population-level data. The design process included user personas and scenarios, screen prototyping and a simulator for generating large-scale data sets. The prototype demonstrates the promise of wide-scale self-administered screening data to support a range of users including practice managers, clinical directors and health policy analysts.

Large area, low cost solar cell development and production readiness

Science.gov (United States)

Michaels, D.

1982-01-01

A process sequence for a large area ( or = 25 sq. cm) silicon solar cell was investigated. Generic cell choice was guided by the expected electron fluence, by the packing factors of various cell envelope designs onto each panel to provide needed voltage as well as current, by the weight constraints on the system, and by the cost goals of the contract.

Search for Higgs portal DM at the ILC

Energy Technology Data Exchange (ETDEWEB)

Ko, P. [School of Physics, KIAS,Seoul 02455 (Korea, Republic of); Quantum Universe Center, KIAS,Seoul 02455 (Korea, Republic of); Yokoya, Hiroshi [Quantum Universe Center, KIAS,Seoul 02455 (Korea, Republic of)

2016-08-18

Higgs portal dark matter (DM) models are simple interesting and viable DM models. There are three types of the models depending on the DM spin: scalar, fermion and vector DM models. In this paper, we consider renormalizable, unitary and gauge invariant Higgs portal DM models, and study how large parameter regions can be surveyed at the International Linear Collider (ILC) experiment at √s=500 GeV. For the Higgs portal singlet fermion and vector DM cases, the force mediator involves two scalar propagators, the SM-like Higgs boson and the dark Higgs boson. We show that their interference generates interesting and important patterns in the mono-Z plus missing E{sub T} signatures at the ILC, and the results are completely different from those obtained from the Higgs portal DM models within the effective field theories. In addition, we show that it would be possible to distinguish the spin of DM in the Higgs portal scenarios, if the shape of the recoil-mass distribution is observed. We emphasize that the interplay between these collider observations and those in the direct detection experiments has to be performed in the model with renomalizability and unitarity to combine the model analyses in different scales.

Quality control of portal imaging with PTW EPID QC PHANTOM {sup registered}

Energy Technology Data Exchange (ETDEWEB)

Pesznyak, Csilla; Kiraly, Reka; Polgar, Istvan; Zarand, Pal; Mayer, Arpad [Inst. of Oncoradiology, Uzsoki Hospital, Budapest (Hungary); Fekete, Gabor [Dept. of Oncotherapy, Univ. of Szeged (Hungary); Mozes, Arpad [Oncology Center, Kalman Pandy County Hospital, Gyula (Hungary); Kiss, Balazs [Dept. of Radiation Oncology, Markusovszky County Hospital, Szombathely (Hungary)

2009-01-15

Purpose: quality assurance (QA) and quality control (QC) of different electronic portal imaging devices (EPID) and portal images with the PTW EPID QC PHANTOM {sup registered}. Material and methods: characteristic properties of images of different file formats were measured on Siemens OptiVue500aSi {sup registered}, Siemens BeamView Plus {sup registered}, Elekta iView {sup registered}, and Varian PortalVision trademark and analyzed with the epidSoft {sup registered} 2.0 program in four radiation therapy centers. The portal images were taken with Kodak X-OMAT V {sup registered} and the Kodak Portal Localisation ReadyPack {sup registered} films and evaluated with the same program. Results: the optimal exposition both for EPIDs and portal films of different kind was determined. For double exposition, the 2+1 MU values can be recommended in the case of Siemens OptiVue500aSi {sup registered}, Elekta iView {sup registered} and Kodak Portal Localisation ReadyPack {sup registered} films, while for Siemens BeamView Plus {sup registered}, Varian PortalVision trademark and Kodak X-OMAT V {sup registered} film 7+7 MU is recommended. Conclusion: the PTW EPID QC PHANTOM {sup registered} can be used not only for amorphous silicon EPIDs but also for images taken with a video-based system or by using an ionization chamber matrix or for portal film. For analysis of QC tests, a standardized format (used at the acceptance test) should be applied, as the results are dependent on the file format used. (orig.)

Portal vein thrombosis is a potentially preventable complication in clinical islet transplantation

Science.gov (United States)

Kawahara, Toshiyasu; Kin, Tatsuya; Kashkoush, Samy; Gala-Lopez, Boris; Bigam, David L.; Kneteman, Norman M.; Koh, Angela; Senior, Peter A.; Shapiro, A.M. James

2011-01-01

Percutaneous transhepatic portal access avoids surgery, but is rarely associated with bleeding or portal venous thrombosis. We herein report our large, single-center experience of percutaneous islet implantation, and evaluate risk factors of portal vein thrombosis and graft function. Prospective data was collected on 268 intraportal islet transplants (122 subjects). A portal venous Doppler ultrasound was obtained on Days 1 and 7 days posttransplant. Therapeutic heparinization, complete ablation of the portal catheter tract with Avitene paste, and limiting packed cell volume to islet transplant procedures over the past 5 years. In the previous cumulative experience, partial thrombosis did not affect islet function. Standard liver volume correlated negatively (r=−0.257, Pislet transplantation, provided therapeutic anticoagulation is maintained, and packed cell volume is limited to <5 ml. PMID:21883914

Pure crystal orientation and anisotropic charge transport in large-area hybrid perovskite films

KAUST Repository

Cho, Nam Chul; Li, Feng; Turedi, Bekir; Sinatra, Lutfan; Sarmah, Smritakshi P.; Parida, Manas R.; Saidaminov, Makhsud I.; Banavoth, Murali; Burlakov, Victor M.; Goriely, Alain; Mohammed, Omar F.; Wu, Tao; Bakr, Osman

2016-01-01

Controlling crystal orientations and macroscopic morphology is vital to develop the electronic properties of hybrid perovskites. Here we show that a large-area, orientationally pure crystalline (OPC) methylammonium lead iodide (MAPbI3) hybrid

DEVELOPMENT OF EDUCATION AND INFORMATION PORTAL OF PHYSICS ACADEMIC COURSE: WEB DESIGN FEATURES

Directory of Open Access Journals (Sweden)

Іryna A. Slipukhina

2018-04-01

Full Text Available The purpose of this article is to present the main components and features of designing an educational and informational portal for students. Selection of personal trajectory is realized through the use of personal account, which includes electronic laboratory reports, information materials on studying progress, means of communication with a teacher, etc. The created portal allows the administrator to easily monitor and check laboratory reports, keep an e-journal with grades. To develop the website design, functional modules and components, the Adobe Photoshop ™ environment was used, as well as the HTML and CSS layout of the web portal. The modern Bootstrap technology was applied to adapt the web page interface. The didactic opportunities of using this portal as a part of personalization process in teaching physics were considered.

Airbus’s Supplier Portal: changing a business paradigm

NARCIS (Netherlands)

E.M. van Raaij (Erik); J.C.M. van den Ende (Jan); D. Baumann (Dominic)

2015-01-01

textabstractWith procurement volume determining 75 to 80 per cent of costs, Airbus heavily depends on its 1,000 or more key suppliers. As a solution to the complexity of its supply chain, it introduced a portal to serve as an electronic marketplace for all interactions with its suppliers. Five years

Automated Classification of Consumer Health Information Needs in Patient Portal Messages.

Science.gov (United States)

Cronin, Robert M; Fabbri, Daniel; Denny, Joshua C; Jackson, Gretchen Purcell

2015-01-01

Patients have diverse health information needs, and secure messaging through patient portals is an emerging means by which such needs are expressed and met. As patient portal adoption increases, growing volumes of secure messages may burden healthcare providers. Automated classification could expedite portal message triage and answering. We created four automated classifiers based on word content and natural language processing techniques to identify health information needs in 1000 patient-generated portal messages. Logistic regression and random forest classifiers detected single information needs well, with area under the curves of 0.804-0.914. A logistic regression classifier accurately found the set of needs within a message, with a Jaccard index of 0.859 (95% Confidence Interval: (0.847, 0.871)). Automated classification of consumer health information needs expressed in patient portal messages is feasible and may allow direct linking to relevant resources or creation of institutional resources for commonly expressed needs.

Biology of portal hypertension.

Science.gov (United States)

McConnell, Matthew; Iwakiri, Yasuko

2018-02-01

Portal hypertension develops as a result of increased intrahepatic vascular resistance often caused by chronic liver disease that leads to structural distortion by fibrosis, microvascular thrombosis, dysfunction of liver sinusoidal endothelial cells (LSECs), and hepatic stellate cell (HSC) activation. While the basic mechanisms of LSEC and HSC dysregulation have been extensively studied, the role of microvascular thrombosis and platelet function in the pathogenesis of portal hypertension remains to be clearly characterized. As a secondary event, portal hypertension results in splanchnic and systemic arterial vasodilation, leading to the development of a hyperdynamic circulatory syndrome and subsequently to clinically devastating complications including gastroesophageal varices and variceal hemorrhage, hepatic encephalopathy from the formation of portosystemic shunts, ascites, and renal failure due to the hepatorenal syndrome. This review article discusses: (1) mechanisms of sinusoidal portal hypertension, focusing on HSC and LSEC biology, pathological angiogenesis, and the role of microvascular thrombosis and platelets, (2) the mesenteric vasculature in portal hypertension, and (3) future directions for vascular biology research in portal hypertension.

Extrahepatic portal hypertension in childhood

International Nuclear Information System (INIS)

Takehara, Hiroo; Komi, Nobuhiko; Goh, Masahiro; Yoshida, Sadahiro; Kameoka, Kazuhiro; Hino, Masao; Sui, Osamu

1986-01-01

Four pediatric patients with extrahepatic portal hypertension had undergone portography and computerized radionuclide angiography in order to examine shape of portal system and to evaluate hepatic blood flow before and aftersurgical treatment. In all patients, cavernous transformation of portal system was demonstrated by portography, and in one of them spontaneous splenorenal shunt occurred. In 3 of them, who underwent esophageal transsection combined with paraesophagogastric devascularization and splenectomy, so-called direct operation, increase of portal blood flow was revealed by computerized radionuclide angiography. It is suggested that direct operation increasing portal blood flow after surgery is effective in treating extrahepatic portal hypertension in childhood. (author)

Reliability in endoscopic diagnosis of portal hypertensive gastropathy

Science.gov (United States)

de Macedo, George Fred Soares; Ferreira, Fabio Gonçalves; Ribeiro, Maurício Alves; Szutan, Luiz Arnaldo; Assef, Mauricio Saab; Rossini, Lucio Giovanni Battista

2013-01-01

AIM: To analyze reliability among endoscopists in diagnosing portal hypertensive gastropathy (PHG) and to determine which criteria from the most utilized classifications are the most suitable. METHODS: From January to July 2009, in an academic quaternary referral center at Santa Casa of São Paulo Endoscopy Service, Brazil, we performed this single-center prospective study. In this period, we included 100 patients, including 50 sequential patients who had portal hypertension of various etiologies; who were previously diagnosed based on clinical, laboratory and imaging exams; and who presented with esophageal varices. In addition, our study included 50 sequential patients who had dyspeptic symptoms and were referred for upper digestive endoscopy without portal hypertension. All subjects underwent upper digestive endoscopy, and the images of the exam were digitally recorded. Five endoscopists with more than 15 years of experience answered an electronic questionnaire, which included endoscopic criteria from the 3 most commonly used Portal Hypertensive Gastropathy classifications (McCormack, NIEC and Baveno) and the presence of elevated or flat antral erosive gastritis. All five endoscopists were blinded to the patients’ clinical information, and all images of varices were deliberately excluded for the analysis. RESULTS: The three most common etiologies of portal hypertension were schistosomiasis (36%), alcoholic cirrhosis (20%) and viral cirrhosis (14%). Of the 50 patients with portal hypertension, 84% were Child A, 12% were Child B, 4% were Child C, 64% exhibited previous variceal bleeding and 66% were previously endoscopic treated. The endoscopic parameters, presence or absence of mosaic-like pattern, red point lesions and cherry-red spots were associated with high inter-observer reliability and high specificity for diagnosing Portal Hypertensive Gastropathy. Sensitivity, specificity and reliability for the diagnosis of PHG (%) were as follows: mosaic-like pattern

Usability of Discovery Portals

NARCIS (Netherlands)

Bulens, J.D.; Vullings, L.A.E.; Houtkamp, J.M.; Vanmeulebrouk, B.

2013-01-01

As INSPIRE progresses to be implemented in the EU, many new discovery portals are built to facilitate finding spatial data. Currently the structure of the discovery portals is determined by the way spatial data experts like to work. However, we argue that the main target group for discovery portals

Quantitative measurement of portal blood flow by magnetic resonance phase contrast. Comparative study of flow phantom and Doppler ultrasound in vivo

International Nuclear Information System (INIS)

Tsunoda, Masatoshi; Kimoto, Shin; Hamazaki, Keisuke; Takeda, Yoshihiro; Hiraki, Yoshio.

1994-01-01

A non-invasive method for measuring portal blood flow by magnetic resonance (MR) phase contrast was evaluated in a flow phantom and 20 healthy volunteers. In a flow phantom study, the flow volumes and mean flow velocities measured by MR phase contrast showed close correlations with those measured by electromagnetic flow-metry. In 20 healthy volunteers, the cross-sectional areas, flow volumes and mean flow velocities measured by MR phase contrast correlated well with those measured by the Doppler ultrasound method. Portal blood flow averaged during the imaging time could be measured under natural breathing conditions by using a large number of acquisitions without the limitations imposed on the Doppler ultrasound method. MR phase contrast is considered to be useful for the non-invasive measurement of portal blood flow. (author)

The Knowledge Portal

Data.gov (United States)

Office of Personnel Management — Information on various courses, as well as personal data of employees and training records from The Knowledge Portal (TKP), a web-based training portal used for the...

Nuclear Instrumentation Module (NIM) standard logic processor as a portal signal analyzer

International Nuclear Information System (INIS)

Minges, G.P.

1978-01-01

A general purpose electronic logic processor has been designed into a 2 wide NIM (Nuclear Instrumentation Module) bin module. The unit utilizes a microprocessor to achieve necessary versatility. The processor's first use is as a new generation signal analyzer for use in radiometric personnel and vehicle portal monitors. Significant improvements have been obtained in sensitivity and stability over existing analog discriminators. The new analyzer is presently being used to update personnel and vehicle portal monitoring systems

Portals people, processes, technology

CERN Document Server

Cox, Andrew

2006-01-01

First applied to internet gateways such as Yahoo, the concept of the ""portal"" has evolved in a number of directions. How can information services best take advantage of internet portals to improve access to resources? This collection seeks answers to such questions, providing an overview of how portals are being used.

Exploratory portals of research data in education

Directory of Open Access Journals (Sweden)

Di Blas Nicoletta

2015-12-01

Full Text Available This paper presents a powerful tool to enhance research in education: ‘exploratory portals’, supporting effective storage, sharing and exploration of large sets of research data. The workflow is the following: data are gathered by a research group; they are then classified according to a taxonomy (the one that best fits the group’s research interest; once uploaded in the portal, they can be ‘explored’ via a combination of faceted search (enriched by Boolean operators and data mining techniques. The system can thus answer in a few seconds to sophisticated user’s queries that otherwise would require hours; it can save a session’s results and materials for sharing with other scholars or for further investigation. The paper presents a case study of exploratory portal, dealing with data on (technology-based education. The portal has effectively been used by five different research groups, to run complex investigations of data about technology integration into schools.

A Brief Technical History of the Large-Area Picosecond Photodetector (LAPPD) Collaboration

Energy Technology Data Exchange (ETDEWEB)

Adams, B.W.; et al.

2016-03-06

The Large Area Picosecond PhotoDetector (LAPPD) Collaboration was formed in 2009 to develop large-area photodetectors capable of time resolutions measured in pico-seconds, with accompanying sub-millimeter spatial resolution. During the next three and one-half years the Collaboration developed the LAPPD design of 20 x 20 cm modules with gains greater than $10^7$ and non-uniformity less than $15\\%$, time resolution less than 50 psec for single photons and spatial resolution of 700~microns in both lateral dimensions. We describe the R\\&D performed to develop large-area micro-channel plate glass substrates, resistive and secondary-emitting coatings, large-area bialkali photocathodes, and RF-capable hermetic packaging. In addition, the Collaboration developed the necessary electronics for large systems capable of precise timing, built up from a custom low-power 15-GigaSample/sec waveform sampling 6-channel integrated circuit and supported by a two-level modular data acquisition system based on Field-Programmable Gate Arrays for local control, data-sparcification, and triggering. We discuss the formation, organization, and technical successes and short-comings of the Collaboration. The Collaboration ended in December 2012 with a transition from R\\&D to commercialization.

The portal protein plays essential roles at different steps of the SPP1 DNA packaging process

International Nuclear Information System (INIS)

Isidro, Anabela; Henriques, Adriano O.; Tavares, Paulo

2004-01-01

A large number of viruses use a specialized portal for entry of DNA to the viral capsid and for its polarized exit at the beginning of infection. These families of viruses assemble an icosahedral procapsid containing a portal protein oligomer in one of its 12 vertices. The viral ATPase (terminase) interacts with the portal vertex to form a powerful molecular motor that translocates DNA to the procapsid interior against a steep concentration gradient. The portal protein is an essential component of this DNA packaging machine. Characterization of single amino acid substitutions in the portal protein gp6 of bacteriophage SPP1 that block DNA packaging identified sequential steps in the packaging mechanism that require its action. Gp6 is essential at early steps of DNA packaging and for DNA translocation to the capsid interior, it affects the efficiency of DNA packaging, it is a central component of the headful sensor that determines the size of the packaged DNA molecule, and is essential for closure of the portal pore by the head completion proteins to prevent exit of the DNA encapsidated. Functional regions of gp6 necessary at each step are identified within its primary structure. The similarity between the architecture of portal oligomers and between the DNA packaging strategies of viruses using portals strongly suggests that the portal protein plays the same roles in a large number of viruses

A nationwide Dutch study regarding treatment portals for elective neck irradiation

Energy Technology Data Exchange (ETDEWEB)

Van Dieren, E B [Integraal Kankercentrum, Rotterdam (Netherlands); Nowak, P J.C.M.; Van Soernsen de Koste, J.R.; Van Est, H; Heijmen, B J.M.; Levendag, P C

1995-12-01

The variation in treatment portals for elective radiotherapy of the neck, and the three-dimensional dosimetric consequences of this variation was assessed. Therefore, 16 experienced radiation oncologists from all major head and neck cooperative groups in the Netherlands (n=11) were asked to define RT-portals on a lateral and/or AP simulation film, for (routine) elective neck irradiation for a T2 tumor of the mobile tongue and a T3 tumor of the supraglottic larynx. Treatment portals were compared and evaluated using a three-dimensional treatment planning system and CT data with contoured critical structures and target volume. The CT-defined clinical target volume was mutually agreed upon by ENT-surgeons and radiation oncologists. Large differences were seen in treated volume (a factor of five). In addition, due to the variation in the cranial boundary of the RT-portals, the estimated NTCP varied considerably (0-50%). Moreover, several of the RT-portals did not adequately cover the CT-defined target volume. Even amongst experienced head and neck radiation oncologists, little agreement was observed with respect to treatment technique and size of the treatment portals in case of elective neck irradiation. This results in a considerable variation in treated volume. As a consequence, a large difference exists in the anticipated probability of normal tissue complication, and possibly in tumor control probability. Therefore, a definition of target volume and, consequently, a standardization of elective neck portals in mandatory. This is even more important if the primary tumor and clinically node-negative neck are to be treated by 3D conformal RT using multiple CT-slices for target delineation and positioning of BEV blocks in order to spare the normal tissue function with maximum tumor control probability.

A nationwide Dutch study regarding treatment portals for elective neck irradiation

International Nuclear Information System (INIS)

Van Dieren, E.B.; Nowak, P.J.C.M.; Van Soernsen de Koste, J.R.; Van Est, H.; Heijmen, B.J.M.; Levendag, P.C.

1995-01-01

The variation in treatment portals for elective radiotherapy of the neck, and the three-dimensional dosimetric consequences of this variation was assessed. Therefore, 16 experienced radiation oncologists from all major head and neck cooperative groups in the Netherlands (n=11) were asked to define RT-portals on a lateral and/or AP simulation film, for (routine) elective neck irradiation for a T2 tumor of the mobile tongue and a T3 tumor of the supraglottic larynx. Treatment portals were compared and evaluated using a three-dimensional treatment planning system and CT data with contoured critical structures and target volume. The CT-defined clinical target volume was mutually agreed upon by ENT-surgeons and radiation oncologists. Large differences were seen in treated volume (a factor of five). In addition, due to the variation in the cranial boundary of the RT-portals, the estimated NTCP varied considerably (0-50%). Moreover, several of the RT-portals did not adequately cover the CT-defined target volume. Even amongst experienced head and neck radiation oncologists, little agreement was observed with respect to treatment technique and size of the treatment portals in case of elective neck irradiation. This results in a considerable variation in treated volume. As a consequence, a large difference exists in the anticipated probability of normal tissue complication, and possibly in tumor control probability. Therefore, a definition of target volume and, consequently, a standardization of elective neck portals in mandatory. This is even more important if the primary tumor and clinically node-negative neck are to be treated by 3D conformal RT using multiple CT-slices for target delineation and positioning of BEV blocks in order to spare the normal tissue function with maximum tumor control probability

Transmission dosimetry with a liquid-filled electronic portal imaging device

Energy Technology Data Exchange (ETDEWEB)

Boellaard, R; Van Herk, M; Mijnheer, B J [Nederlands Kanker Inst. ` Antoni van Leeuwenhoekhuis` , Amsterdam (Netherlands)

1995-12-01

The aim of transmission dosimetry is to correlate transmission dose values with patient dose values. A liquid-filled electronic portal imaging device (EPID) has been developed. After determination of the dose response relationship, i.e. the relation between pixel value and dose rate, for clinical situations it was found that the EPID is applicable for two-dimensional dosimetry with an accuracy of about 1%. The aim of this study was to investigate transmission dose distributions at different phantom-detector distances to predict exit dose distributions from transmission dose images. An extensive set of transmission dose measurements below homogeneous phantoms were performed with the EPID. The influence of several parameters such as field size, phantom thickness, phantom-detector distance and phantom-source distance on the transmission dose and its distribution were investigated. The two-dimensional transmission dose images were separated into two components: a primary dose and a scattered dose distribution. It was found that the scattered dose is maximal at a phantom thickness of about 10 cm. The scattered dose distribution below a homogeneous phantom has a Gaussian shape. The width of the Gaussian is small at small phantom-detector distances and increases for larger phantom-detector distances. The dependence of the scattered dose distribution on the field size at various phantom-detector distances has been used to estimate the dose distribution at the exit site of the phantom. More work is underway to determine the exit dose distributions for clinical situations, including the presence of inhomogeneities.

Transmission dosimetry with a liquid-filled electronic portal imaging device

International Nuclear Information System (INIS)

Boellaard, R.; Van Herk, M.; Mijnheer, B.J.

1995-01-01

The aim of transmission dosimetry is to correlate transmission dose values with patient dose values. A liquid-filled electronic portal imaging device (EPID) has been developed. After determination of the dose response relationship, i.e. the relation between pixel value and dose rate, for clinical situations it was found that the EPID is applicable for two-dimensional dosimetry with an accuracy of about 1%. The aim of this study was to investigate transmission dose distributions at different phantom-detector distances to predict exit dose distributions from transmission dose images. An extensive set of transmission dose measurements below homogeneous phantoms were performed with the EPID. The influence of several parameters such as field size, phantom thickness, phantom-detector distance and phantom-source distance on the transmission dose and its distribution were investigated. The two-dimensional transmission dose images were separated into two components: a primary dose and a scattered dose distribution. It was found that the scattered dose is maximal at a phantom thickness of about 10 cm. The scattered dose distribution below a homogeneous phantom has a Gaussian shape. The width of the Gaussian is small at small phantom-detector distances and increases for larger phantom-detector distances. The dependence of the scattered dose distribution on the field size at various phantom-detector distances has been used to estimate the dose distribution at the exit site of the phantom. More work is underway to determine the exit dose distributions for clinical situations, including the presence of inhomogeneities

Final Report for DOE Project: Portal Web Services: Support of DOE SciDAC Collaboratories

Energy Technology Data Exchange (ETDEWEB)

Mary Thomas, PI; Geoffrey Fox, Co-PI; Gannon, D; Pierce, M; Moore, R; Schissel, D; Boisseau, J

2007-10-01

Grid portals provide the scientific community with familiar and simplified interfaces to the Grid and Grid services, and it is important to deploy grid portals onto the SciDAC grids and collaboratories. The goal of this project is the research, development and deployment of interoperable portal and web services that can be used on SciDAC National Collaboratory grids. This project has four primary task areas: development of portal systems; management of data collections; DOE science application integration; and development of web and grid services in support of the above activities.

Perivesical varices and portal hypertension: imaging study

International Nuclear Information System (INIS)

Mallorquin Jimenez, F.; Medina Benitez, A.; Lopez Machado, E.; Pardo Moreno, M.D.; Garrido Moreno, C.; Pastor Rull, J.

1995-01-01

Nine patients with portal hypertension syndrome and Perivesical varices are studied retrospectively by means of imaging techniques including ultrasound, duplex Doppler, color Doppler, CT and angiography. All the patients presented portal thrombosis and thickening of the bladder wall. These collaterals either represent a shunting of hepato pedal flow or correspond to blood stasis associated with said syndrome. Ultrasound, whether involving duplex Doppler or color Doppler techniques, is highly useful to detect the presence of Perivesical varices which appear as tubular or rounded hypo echogenic areas in the bladder wall. Given the association of this entity with bladder wall thickening, it should be taken into account in any clinical situation involving said change, especially in patients with portal hypertension; moreover knowledge of its presence is of great importance when the possibility of creating shunts by means of interventional or surgical vascular procedures or other types of abdominal procedures are being considered because of the risk of bleeding. (Author)

Regional blood flows by the microsphere method: reproducibility in portal hypertensive rats and influence of a portal vein catheter

International Nuclear Information System (INIS)

Hadengue, A.; Lee, S.S.; Koshy, A.; Girod, C.; Lebrec, D.

1988-01-01

To determine the reproducibility of splanchnic blood flow measurements by the microsphere method in rats with portal hypertension and the effects of laparotomy with portal vein cannulation, eight groups of 10 rats were studied. Microspheres were labelled with 113 Sn or 141 Ce. Laparotomy with portal cannulation had no significant effect in sham-operated rats. In awake portal hypertensive rats, cardiac output and splanchnic blood flow were lower in portal vein cannulated rats compared with those of non-cannulated animals. In anesthetized portal hypertensive rats blood flows were unaffected by portal cannulation, but arterial pressure and heart rate were elevated. Anesthesia also decreased portal pressure in portal hypertensive rats. We conclude that the microsphere method remains reproducible in portal hypertensive rat models. Laparotomy with portal cannulation can alter systemic and splanchnic hemodynamics in portal hypertensive rats; these effects can also be changed during pentobarbital anesthesia. Regional blood flow measurements in portal hypertensive rats should be performed in animals without portal cannulation and preferably in the awake state

Automated Classification of Consumer Health Information Needs in Patient Portal Messages

Science.gov (United States)

Cronin, Robert M.; Fabbri, Daniel; Denny, Joshua C.; Jackson, Gretchen Purcell

2015-01-01

Patients have diverse health information needs, and secure messaging through patient portals is an emerging means by which such needs are expressed and met. As patient portal adoption increases, growing volumes of secure messages may burden healthcare providers. Automated classification could expedite portal message triage and answering. We created four automated classifiers based on word content and natural language processing techniques to identify health information needs in 1000 patient-generated portal messages. Logistic regression and random forest classifiers detected single information needs well, with area under the curves of 0.804–0.914. A logistic regression classifier accurately found the set of needs within a message, with a Jaccard index of 0.859 (95% Confidence Interval: (0.847, 0.871)). Automated classification of consumer health information needs expressed in patient portal messages is feasible and may allow direct linking to relevant resources or creation of institutional resources for commonly expressed needs. PMID:26958285

Fabrication of large area flexible nanoplasmonic templates with flow coating

Science.gov (United States)

Huang, Qian; Devetter, Brent M.; Roosendaal, Timothy; LaBerge, Max; Bernacki, Bruce E.; Alvine, Kyle J.

2017-07-01

We describe the development of a custom-built two-axis flow coater for the deposition of polymeric nanosphere monolayers that could be used in the fabrication of large area nanoplasmonic films. The technique described here has the capability of depositing large areas (up to 7 in. × 10 in.) of self-assembled monolayers of polymeric nanospheres onto polyethylene terephthalate (PET) films. Here, three sets of films consisting of different diameters (ranging from 100 to 300 nm) of polymeric nanospheres were used to demonstrate the capabilities of this instrument. To improve the surface wettability of the PET substrates during wet-deposition, we enhanced the wettability by using a forced air blown-arc plasma treatment system. Both the local microstructure, as confirmed by scanning electron microscopy, describing monolayer and multilayer coverage, and the overall macroscopic uniformity of the resultant nanostructured film were optimized by controlling the relative stage to blade speed and nanosphere concentration. We also show using a smaller nanoparticle template that such monolayers can be used to form nanoplasmonic films. As this flow-coating approach is a scalable technique, large area films such as the ones described here have a variety of crucial emerging applications in areas such as energy, catalysis, and chemical sensing.

Assessment of dosimetrical performance in 11 Varian a-Si500 electronic portal imaging devices

International Nuclear Information System (INIS)

Kavuma, Awusi; Glegg, Martin; Currie, Garry; Elliott, Alex

2008-01-01

Dosimetrical characteristics of 11 Varian a-Si-500 electronic portal imaging devices (EPIDs) in clinical use for periods ranging between 10 and 86 months were investigated for consistency of performance and portal dosimetry implications. Properties studied include short-term reproducibility, signal linearity with monitor units, response to reference beam, signal uniformity across the detector panel, signal dependence on field size, dose-rate influence, memory effects and image profiles as a function of monitor units. The EPID measurements were also compared with those of the ionization chambers' to ensure stability of the linear accelerators. Depending on their clinical installation date, the EPIDs were interfaced with one of the two different acquisition control software packages, IAS2/IDU-II or IAS3/IDU-20. Both the EPID age and image acquisition system influenced the dosimetric characteristics with the newer version (IAS3 with IDU-20) giving better data reproducibility and linearity fit than the older version (IAS2 with IDU-II). The relative signal response (uniformity) after 50 MU was better than 95% of the central value and independent of detector. Sensitivity for all EPIDs reduced continuously with increasing dose rates for the newer image acquisition software. In the dose-rate range 100-600 MU min -1 , the maximum variation in sensitivity ranged between 1 and 1.8% for different EPIDs. For memory effects, the increase in the measured signal at the centre of the irradiated field for successive images was within 1.8% and 1.0% for the older and newer acquisition systems, respectively. Image profiles acquired at a lower MU in the radial plane (gun-target) had gradients in measured pixel values of up to 25% for the older system. Detectors with software/hardware versions IAS3/IDU-20 have a high degree of accuracy and are more suitable for routine quantitative IMRT dosimetrical verification.

R2 Water Quality Portal Monitoring Stations

Science.gov (United States)

The Water Quality Data Portal (WQP) provides an easy way to access data stored in various large water quality databases. The WQP provides various input parameters on the form including location, site, sampling, and date parameters to filter and customize the returned results. The The Water Quality Portal (WQP) is a cooperative service sponsored by the United States Geological Survey (USGS), the Environmental Protection Agency (EPA) and the National Water Quality Monitoring Council (NWQMC) that integrates publicly available water quality data from the USGS National Water Information System (NWIS) the EPA STOrage and RETrieval (STORET) Data Warehouse, and the USDA ARS Sustaining The Earth??s Watersheds - Agricultural Research Database System (STEWARDS).

Applications of portals in the energetic sector; Aplicaciones de portales en el sector energetico

Energy Technology Data Exchange (ETDEWEB)

Santos Dominguez, Martin; Arroyo Figueroa, Gustavo [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

2000-07-01

An operative portal joins the applications, contents and services of the company in a single page of Intranet such way that promises to change deeply the information technology in the next years. The corporative portals will change what people visualize in the screen of their computer at the beginning of every working day. Unlike seeing the network (Web) only with pages of language of hypertext bearing (HTML), the corporative portal acts as a gate between Internet and the private networks. This article presents a general vision of the benefits of the corporative portals, the existing technologies and the potential markets. [Spanish] Un portal operativo une las aplicaciones, contenidos y servicios de la empresa en una sola pagina de Intranet, de tal forma que promete cambiar, profundamente la tecnologia de la informacion en los proximos anos. Los portales corporativos cambiaran lo que la gente visualiza en la pantalla de su computadora al comienzo de cada dia de trabajo. A diferencia de ver la red (Web) solo con paginas de lenguaje de marcacion de hipertexto (HTML), el portal corporativo actua como compuerta entre Internet y las redes privadas. Este articulo presenta una vision general de los beneficios de los portales corporativos, las tecnologias y los mercados potenciales existentes.

The Digital Divide and Patient Portals: Internet Access Explained Differences in Patient Portal Use for Secure Messaging by Age, Race, and Income.

Science.gov (United States)

Graetz, Ilana; Gordon, Nancy; Fung, Vick; Hamity, Courtnee; Reed, Mary E

2016-08-01

Online access to health records and the ability to exchange secure messages with physicians can improve patient engagement and outcomes; however, the digital divide could limit access to web-based portals among disadvantaged groups. To understand whether sociodemographic differences in patient portal use for secure messaging can be explained by differences in internet access and care preferences. Cross-sectional survey to examine the association between patient sociodemographic characteristics and internet access and care preferences; then, the association between sociodemographic characteristics and secure message use with and without adjusting for internet access and care preference. One thousand forty-one patients with chronic conditions in a large integrated health care delivery system (76% response rate). Internet access, portal use for secure messaging, preference for in-person or online care, and sociodemographic and health characteristics. Internet access and preference mediated some of the differences in secure message use by age, race, and income. For example, using own computer to access the internet explained 52% of the association between race and secure message use and 60% of the association between income and use (Sobel-Goodman mediation test, Pdifferences in portal use remained statistically significant when controlling for internet access and preference. As the availability and use of patient portals increase, it is important to understand which patients have limited access and the barriers they may face. Improving internet access and making portals available across multiple platforms, including mobile, may reduce some disparities in secure message use.

Ligation of superior mesenteric vein and portal to splenic vein anastomosis after superior mesenteric-portal vein confluence resection during pancreaticoduodenectomy - Case report.

Science.gov (United States)

Tang, Jianlin; Abbas, Jihad; Hoetzl, Katherine; Allison, David; Osman, Mahamed; Williams, Mallory; Zelenock, Gerald B

2014-12-01

62 year old Caucasian female with pancreatic head mass abutting the superior mesenteric vein (SMV) presented with fine needle aspiration biopsy confirmed diagnosis of ductal adenocarcinoma. CT scan showed near complete obstruction of portal vein and large SMV collateral development. After 3 months of neoadjuvant therapy, her portal vein flow improved significantly, SMV collateral circulation was diminished. Pancreaticoduodenectomy (PD) and superior mesenteric portal vein (SMPV) confluence resection were performed; A saphenous vein interposition graft thrombosed immediately. The splenic vein remnant was distended and adjacent to the stump of the portal vein. Harvesting an internal jugular vein graft required extra time and using a synthetic graft posed a risk of graft thrombosis or infection. As a result, we chose to perform a direct anastomosis of the portal and splenic vein in a desperate situation. The anastomosis decompressed the mesenteric venous system, so we then ligated the SMV. The patient had an uneventful postoperative course, except transient ascites. She redeveloped ascites more than one year later. At that time a PET scan showed bilateral lung and right femur metastatic disease. She expired 15 months after PD. The lessons we learned are (1) Before SMPV confluence resection, internal jugular vein graft should be ready for reconstruction. (2) Synthetic graft is an alternative for internal jugular vein graft. (3) Direct portal vein to SMV anastomosis can be achieved by mobilizing liver. (4) It is possible that venous collaterals secondary to SMV tumor obstruction may have allowed this patient's post-operative survival.

Oncogenomic portals for the visualization and analysis of genome-wide cancer data.

Science.gov (United States)

Klonowska, Katarzyna; Czubak, Karol; Wojciechowska, Marzena; Handschuh, Luiza; Zmienko, Agnieszka; Figlerowicz, Marek; Dams-Kozlowska, Hanna; Kozlowski, Piotr

2016-01-05

Somatically acquired genomic alterations that drive oncogenic cellular processes are of great scientific and clinical interest. Since the initiation of large-scale cancer genomic projects (e.g., the Cancer Genome Project, The Cancer Genome Atlas, and the International Cancer Genome Consortium cancer genome projects), a number of web-based portals have been created to facilitate access to multidimensional oncogenomic data and assist with the interpretation of the data. The portals provide the visualization of small-size mutations, copy number variations, methylation, and gene/protein expression data that can be correlated with the available clinical, epidemiological, and molecular features. Additionally, the portals enable to analyze the gathered data with the use of various user-friendly statistical tools. Herein, we present a highly illustrated review of seven portals, i.e., Tumorscape, UCSC Cancer Genomics Browser, ICGC Data Portal, COSMIC, cBioPortal, IntOGen, and BioProfiling.de. All of the selected portals are user-friendly and can be exploited by scientists from different cancer-associated fields, including those without bioinformatics background. It is expected that the use of the portals will contribute to a better understanding of cancer molecular etiology and will ultimately accelerate the translation of genomic knowledge into clinical practice.

Large area electron beam pumped krypton fluoride laser amplifier

International Nuclear Information System (INIS)

Sethian, J.D.; Obenschain, S.P.; Gerber, K.A.; Pawley, C.J.; Serlin, V.; Sullivan, C.A.; Webster, W.; Deniz, A.V.; Lehecka, T.; McGeoch, M.W.; Altes, R.A.; Corcoran, P.A.; Smith, I.D.; Barr, O.C.

1997-01-01

Nike is a recently completed multi-kilojoule krypton fluoride (KrF) laser that has been built to study the physics of direct drive inertial confinement fusion. This paper describes in detail both the pulsed power and optical performance of the largest amplifier in the Nike laser, the 60 cm amplifier. This is a double pass, double sided, electron beam-pumped system that amplifies the laser beam from an input of 50 J to an output of up to 5 kJ. It has an optical aperture of 60 cm x 60 cm and a gain length of 200 cm. The two electron beams are 60 cm high x 200 cm wide, have a voltage of 640 kV, a current of 540 kA, and a flat top power pulse duration of 250 ns. A 2 kG magnetic field is used to guide the beams and prevent self-pinching. Each electron beam is produced by its own Marx/pulse forming line system. The amplifier has been fully integrated into the Nike system and is used on a daily basis for laser-target experiments. copyright 1997 American Institute of Physics

Three-dimensional Structure of a Viral Genome-delivery Portal Vertex

Energy Technology Data Exchange (ETDEWEB)

A Olia; P Prevelige Jr.; J Johnson; G Cingolani

2011-12-31

DNA viruses such as bacteriophages and herpesviruses deliver their genome into and out of the capsid through large proteinaceous assemblies, known as portal proteins. Here, we report two snapshots of the dodecameric portal protein of bacteriophage P22. The 3.25-{angstrom}-resolution structure of the portal-protein core bound to 12 copies of gene product 4 (gp4) reveals a {approx}1.1-MDa assembly formed by 24 proteins. Unexpectedly, a lower-resolution structure of the full-length portal protein unveils the unique topology of the C-terminal domain, which forms a {approx}200-{angstrom}-long {alpha}-helical barrel. This domain inserts deeply into the virion and is highly conserved in the Podoviridae family. We propose that the barrel domain facilitates genome spooling onto the interior surface of the capsid during genome packaging and, in analogy to a rifle barrel, increases the accuracy of genome ejection into the host cell.

Elastography methods for the non-invasive assessment of portal hypertension.

Science.gov (United States)

Roccarina, Davide; Rosselli, Matteo; Genesca, Joan; Tsochatzis, Emmanuel A

2018-02-01

The gold standard to assess the presence and severity of portal hypertension remains the hepatic vein pressure gradient, however the recent development of non-invasive assessment using elastography techniques offers valuable alternatives. In this review, we discuss the diagnostic accuracy and utility of such techniques in patients with portal hypertension due to cirrhosis. Areas covered: A literature search focused on liver and spleen stiffness measurement with different elastographic techniques for the assessment of the presence and severity of portal hypertension and oesophageal varices in people with chronic liver disease. The combination of elastography with parameters such as platelet count and spleen size is also discussed. Expert commentary: Non-invasive assessment of liver fibrosis and portal hypertension is a validated tool for the diagnosis and follow-up of patients. Baveno VI recommended the combination of transient elastography and platelet count for ruling out varices needing treatment in patients with compensated advanced chronic liver disease. Assessment of aetiology specific cut-offs for ruling in and ruling out clinically significant portal hypertension is an unmet clinical need. The incorporation of spleen stiffness measurements in non-invasive algorithms using validated software and improved measuring scales might enhance the non-invasive diagnosis of portal hypertension in the next 5 years.

Portal venous anatomy in right lobe of the liver : CT evaluation

International Nuclear Information System (INIS)

Shin, Kue Hee; Kim, Hyung Seuk; Kim, Tae Hyung; Lee, Ki Yeol; Park, Cheol Min; Cha, In Ho

1997-01-01

To evaluate the portal venous anatomy in the right lobe of the liver, focusing particularly on the location and size of the anterior and posterior segmental branches of the portal vein and the relationship of the right subdiaphragmatic peripheral portal vein to the right hepatic vein. From June 1995 to December 1995, 100 spiral CT scan which showed no abnormal findings in the hepatic area were retrospectively analysed. Portal dominant phase images were obtained after the administration of contrast media, with a delay of 60-65seconds (100-120ml, 2-3ml/sec injection rate), slice thickness 10mm and table speed 10mm/sec. On spiral CT scans, we assessed the location and size of the right portal vein and its branches and also observed the relationship of this vein to the right hepatic vein. In all patients, the right portal trunk divided into anterior and posterior branches. The anterior segmental portal vein was located cephalad to the posterior segment in 81cases (81%), at the same level in 17 (17%), and caudad in two (2%). Its diameter was greater (>2mm) than that of its posterior segment in 33cases (33%), smaller in three (3%), and similar in 64 (64%). In 95cases, the right anterior segmetal portal vein which was directed posteriorly, supplied the subdiaphragmatic portion of segment 7. In 81% of cases, the position of the anterior segmental portal vein cephalad, and in 64% of cases it was similar in size to the posterior portal vein. In almost all cases, the subdiaphragmatic portion of segment 7 was supplied by the portal vein from segment 8. Therefore, the right hepatic vein is not in all cases an adequate landmark for dividing Couinaud segments 7 and 8 in the subdiaphragmatic portion

From EGEE Operations Portal towards EGI Operations Portal

Science.gov (United States)

Cordier, Hélène; L'Orphelin, Cyril; Reynaud, Sylvain; Lequeux, Olivier; Loikkanen, Sinikka; Veyre, Pierre

Grid operators in EGEE have been using a dedicated dashboard as their central operational tool, stable and scalable for the last 5 years despite continuous upgrade from specifications by users, monitoring tools or data providers. In EGEE-III, recent regionalisation of operations led the Operations Portal developers to conceive a standalone instance of this tool. We will see how the dashboard reorganization paved the way for the re-engineering of the portal itself. The outcome is an easily deployable package customized with relevant information sources and specific decentralized operational requirements. This package is composed of a generic and scalable data access mechanism, Lavoisier; a renowned php framework for configuration flexibility, Symfony and a MySQL database. VO life cycle and operational information, EGEE broadcast and Downtime notifications are next for the major reorganization until all other key features of the Operations Portal are migrated to the framework. Features specifications will be sketched at the same time to adapt to EGI requirements and to upgrade. Future work on feature regionalisation, on new advanced features or strategy planning will be tracked in EGI- Inspire through the Operations Tools Advisory Group, OTAG, where all users, customers and third parties of the Operations Portal are represented from January 2010.

The Fermi Large Area Telescope as a cosmic-ray detector

International Nuclear Information System (INIS)

Sgrò, Carmelo

2013-01-01

The Fermi Large Area Telescope is an international observatory conceived to study high energy gamma-rays from the universe. It is designed to identify and reconstruct electromagnetic showers and it can collect cosmic-ray electrons and positrons thanks to its triggering and filtering capabilities. The Fermi LAT collaboration has published several results on charged cosmic rays. We measured the inclusive spectrum of electrons and positrons from 7 GeV to 1 TeV and searched for anisotropies in the electron incoming direction. We have recently published a measurement of cosmic-ray positron-only and electron-only spectra for energies between 20 GeV and 200 GeV exploiting the Earth's magnetic field as a charge separator. In this work we describe the techniques and capabilities of the LAT as a cosmic-ray detector and review the recent results and their interpretations. Prospects for future studies and observations will also be discussed

DES Science Portal: II- Creating Science-Ready Catalogs

Energy Technology Data Exchange (ETDEWEB)

Fausti Neto, Angelo; et al.

2017-08-18

We present a novel approach for creating science-ready catalogs through a software infrastructure developed for the Dark Energy Survey (DES). We integrate the data products released by the DES Data Management and additional products created by the DES collaboration in an environment known as DES Science Portal. Each step involved in the creation of a science-ready catalog is recorded in a relational database and can be recovered at any time. We describe how the DES Science Portal automates the creation and characterization of lightweight catalogs for DES Year 1 Annual Release, and show its flexibility in creating multiple catalogs with different inputs and configurations. Finally, we discuss the advantages of this infrastructure for large surveys such as DES and the Large Synoptic Survey Telescope. The capability of creating science-ready catalogs efficiently and with full control of the inputs and configurations used is an important asset for supporting science analysis using data from large astronomical surveys.

Utilization of an electronic portal imaging device for measurement of dynamic wedge data

International Nuclear Information System (INIS)

Elder, Eric S.; Miner, Marc S.; Butker, Elizabeth K.; Sutton, Danny S.; Davis, Lawrence W.

1996-01-01

Purpose/Objective: Due to the motion of the collimator during dynamic wedge treatments, the conventional method of collecting comprehensive wedge data with a water tank and a scanning ionization chamber is obsolete. It is the objective of this work to demonstrate the use of an electronic portal imaging device (EPID) and software to accomplish this task. Materials and Methods: A Varian Clinac[reg] 2300 C/D, equipped with a PortalVision TM EPID and Dosimetry Research Mode experimental software, was used to produce the radiation field. The Dosimetry Research Mode experimental software allows for a band of 10 of 256 high voltage electrodes to be continuously read and averaged by the 256 electrometer electrodes. The file that is produced contains data relating to the integrated ionization at each of the 256 points, essentially the cross plane beam profile. Software was developed using Microsoft C ++ to reformat the data for import into a Microsoft Excel spreadsheet allowing for easy mathematical manipulation and graphical display. Beam profiles were measured by the EPID with a 100 cm TSD for various field sizes. Each field size was measured open, steel wedged, and dynamically wedged. Scanning ionization chamber measurements performed in a water tank were compared to the open and steel wedged fields. Ionization chamber measurements taken in a water tank were compared with the dynamically wedged measurements. For the EPID measurements the depth was varied using Gammex RMI Solid Water TM placed directly above the EPID sensitive volume. Bolus material was placed between the Solid Water TM and the EPID to avoid an air gap. Results: Comparison of EPID measurements with those from an ion chamber in a water tank showed a discrepancy of ∼5%. Scans were successfully obtained for open, steel wedged and dynamically wedged beams. Software has been developed to allow for easy graphical display of beam profiles. Conclusions: Measurement of dynamic wedge data proves to be easily

Tests of innovative photon detectors and integrated electronics for the large-area CLAS12 ring-imaging Cherenkov detector

Energy Technology Data Exchange (ETDEWEB)

Contalbrigo, M., E-mail: contalbrigo@fe.infn.it

2015-07-01

A large area ring-imaging Cherenkov detector has been designed to provide clean hadron identification capability in the momentum range from 3 GeV/c to 8 GeV/c for the CLAS12 experiments at the upgraded 12 GeV continuous electron beam accelerator facility of Jefferson Lab. Its aim is to study the 3D nucleon structure in the yet poorly explored valence region by deep-inelastic scattering, and to perform precision measurements in hadron spectroscopy. The adopted solution foresees a novel hybrid optics design based on an aerogel radiator, composite mirrors and a densely packed and highly segmented photon detector. Cherenkov light will either be imaged directly (forward tracks) or after two mirror reflections (large angle tracks). Extensive tests have been performed on Hamamatsu H8500 and novel flat multi-anode photomultipliers under development and on various types of silicon photomultipliers. A large scale prototype based on 28 H8500 MA-PMTs has been realized and tested with few GeV/c hadron beams at the T9 test-beam facility of CERN. In addition a small prototype was used to study the response of customized SiPM matrices within a temperature interval ranging from 25 down to −25 °C. The preliminary results of the individual photon detector tests and of the prototype performance at the test-beams are here reported.

The effect of partial portal decompression on portal blood flow and effective hepatic blood flow in man: a prospective study.

Science.gov (United States)

Rosemurgy, A S; McAllister, E W; Godellas, C V; Goode, S E; Albrink, M H; Fabri, P J

1995-12-01

With the advent of transjugular intrahepatic porta-systemic stent shunt and the wider application of the surgically placed small diameter prosthetic H-graft portacaval shunt (HGPCS), partial portal decompression in the treatment of portal hypertension has received increased attention. The clinical results supporting the use of partial portal decompression are its low incidence of variceal rehemorrhage due to decreased portal pressures and its low rate of hepatic failure, possibly due to maintenance of blood flow to the liver. Surprisingly, nothing is known about changes in portal hemodynamics and effective hepatic blood flow following partial portal decompression. To prospectively evaluate changes in portal hemodynamics and effective hepatic blood flow brought about by partial portal decompression, the following were determined in seven patients undergoing HGPCS: intraoperative pre- and postshunt portal vein pressures and portal vein-inferior vena cava pressure gradients, intraoperative pre- and postshunt portal vein flow, and pre- and postoperative effective hepatic blood flow. With HGPCS, portal vein pressures and portal vein-inferior vena cava pressure gradients decreased significantly, although portal pressures remained above normal. In contrast to the significant decreases in portal pressures, portal vein blood flow and effective hepatic blood flow do not decrease significantly. Changes in portal vein pressures and portal vein-inferior vena cava pressure gradients are great when compared to changes in portal vein flow and effective hepatic blood flow. Reduction of portal hypertension with concomitant maintenance of hepatic blood flow may explain why hepatic dysfunction is avoided following partial portal decompression.

A Novel Method of Fabricating Flexible Transparent Conductive Large Area Graphene Film

International Nuclear Information System (INIS)

Fan Tian-Ju; Yuan Chun-Qiu; Tang Wei; Tong Song-Zhao; Huang Wei; Min Yong-Gang; Liu Yi-Dong; Epstein, Arthur J.

2015-01-01

We fabricate flexible conductive and transparent graphene films on position-emission-tomography substrates and prepare large area graphene films by graphite oxide sheets with the new technical process. The multi-layer graphene oxide sheets can be chemically reduced by HNO 3 and HI to form a highly conductive graphene film on a substrate at lower temperature. The reduced graphene oxide sheets show a high conductivity sheet with resistance of 476 Ω/sq and transmittance of 76% at 550 nm (6 layers). The technique used to produce the transparent conductive graphene thin film is facile, inexpensive, and can be tunable for a large area production applied for electronics or touch screens. (paper)

Impact of health portal enrollment with email reminders on adherence to clinic appointments: a pilot study.

Science.gov (United States)

Horvath, Monica; Levy, Janet; L'Engle, Pete; Carlson, Boyd; Ahmad, Asif; Ferranti, Jeffrey

2011-05-26

Internet portal technologies that provide access to portions of electronic health records have the potential to revolutionize patients' involvement in their care. However, relatively few descriptions of the demographic characteristics of portal enrollees or of the effects of portal technology on quality outcomes exist. This study examined data from patients who attended one of seven Duke Medicine clinics and who were offered the option of enrolling in and using the Duke Medicine HealthView portal (HVP). The HVP allows patients to manage details of their appointment scheduling and provides automated email appointment reminders in addition to the telephone and mail reminders that all patients receive. Our objective was to test whether portal enrollment with an email reminder functionality is significantly related to decreases in rates of appointment "no-shows," which are known to impair clinic operational efficiency. Appointment activity during a 1-year period was examined for all patients attending one of seven Duke Medicine clinics. Patients were categorized as portal enrollees or as nonusers either by their status at time of appointment or at the end of the 1-year period. Demographic characteristics and no-show rates among these groups were compared. A binomial logistic regression model was constructed to measure the adjusted impact of HVP enrollment on no-show rates, given confounding factors. To demonstrate the effect of HVP use over time, monthly no-show rates were calculated for patient appointment keeping and contrasted between preportal and postportal deployment periods. Across seven clinics, 58,942 patients, 15.7% (9239/58,942) of whom were portal enrollees, scheduled 198,199 appointments with an overall no-show rate of 9.9% (19,668/198,199). We found that HVP enrollees were significantly more likely to be female, white, and privately insured compared with nonusers. Bivariate no-show rate differences between portal enrollment groups varied widely according

Glutamine synthetase activity and glutamate uptake in hippocampus and frontal cortex in portal hypertensive rats

Science.gov (United States)

Acosta, Gabriela Beatriz; Fernández, María Alejandra; Roselló, Diego Martín; Tomaro, María Luján; Balestrasse, Karina; Lemberg, Abraham

2009-01-01

AIM: To study glutamine synthetase (GS) activity and glutamate uptake in the hippocampus and frontal cortex (FC) from rats with prehepatic portal vein hypertension. METHODS: Male Wistar rats were divided into sham-operated group and a portal hypertension (PH) group with a regulated stricture of the portal vein. Animals were sacrificed by decapitation 14 d after portal vein stricture. GS activity was determined in the hippocampus and FC. Specific uptake of radiolabeled L-glutamate was studied using synaptosome-enriched fractions that were freshly prepared from both brain areas. RESULTS: We observed that the activity of GS increased in the hippocampus of PH rats, as compared to control animals, and decreased in the FC. A significant decrease in glutamate uptake was found in both brain areas, and was more marked in the hippocampus. The decrease in glutamate uptake might have been caused by a deficient transport function, significantly and persistent increase in this excitatory neurotransmitter activity. CONCLUSION: The presence of moderate ammonia blood levels may add to the toxicity of excitotoxic glutamate in the brain, which causes alterations in brain function. Portal vein stricture that causes portal hypertension modifies the normal function in some brain regions. PMID:19533812

Contrast-enhanced sonography for quantitative assessment of portal hypertension in patients with liver cirrhosis.

Science.gov (United States)

Qu, En-Ze; Zhang, Ying-Cai; Li, Zhi-Yan; Liu, Yang; Wang, Jin-Rui

2014-11-01

The clinical utility of contrast-enhanced sonography in portal hypertension remains unclear. We explored the feasibility of using contrast-enhanced sonography for noninvasive assessment of portal venous pressure. Twenty healthy individuals (control group; 9 men; mean age, 46.4 years) and 18 patients with portal hypertension (15 men; mean age, 46.2 years) were enrolled in this study. The portal hypertension group included patients who underwent splenectomy and pericardial blood vessel disarticulation at our hospital from October 2010 to March 2011. One week before surgery, patients with portal hypertension underwent preoperative liver contrast-enhanced sonography. Two-dimensional, Doppler, and contrast-enhanced sonographic parameters were compared between the groups. Portal venous pressure was measured intraoperatively by portal vein puncture in the portal hypertension group, and its relationship with the other parameters was analyzed. The 2-dimensional, Doppler, and contrast-enhanced sonographic parameters differed between the groups (P Portal venous pressure was inversely correlated with the area under the portal vein/hepatic artery time-intensity curve ratio (Qp/Qa), portal vein/hepatic artery strength ratio (Ip/Ia), and portal vein/hepatic artery wash-in perfusion slope ratio (βp/βa), with correlation coefficients of -0.701, -0.625, and -0.494, respectively. Measurement of the liver contrast-enhanced sonographic parameters Qp/Qa, Ip/Ia, and βp/βa could be used as a new quantitative method for noninvasively assessing portal venous pressure. © 2014 by the American Institute of Ultrasound in Medicine.

Magnetic Resonance Imaging of a Liver Hydatid Cyst Invading the Portal Vein and Causing Portal Cavernomatosis.

Science.gov (United States)

Herek, Duygu; Sungurtekin, Ugur

2015-01-01

Hepatic hydatid cysts rarely invade portal veins causing portal cavernomatosis as a secondary complication. We report the case of a patient with direct invasion of the right portal vein by hydatid cysts causing portal cavernomatosis diagnosed via magnetic resonance imaging (MRI). The presented case highlights the useful application of MRI with T2-weighted images and gadolinium-enhanced T1-weighted images in the diagnosis of hepatic hydatid lesions presenting with a rare complication of portal cavernomatosis.

IMPROVEMENT OF SCHISTOSOMAL PORTAL HYPERTENSIVE COLOPATHY AFTER SURGICAL TREATMENT

Directory of Open Access Journals (Sweden)

Maria Angelina Carvalho MIRANDA

2013-04-01

Full Text Available Context Data on vascular alterations in patients with hepatosplenic schistosomiasis and portal hypertensive colopathy and changes in these after surgery to decrease portal hypertension are limited. Objective The purpose of this study was to analyse the alterations of portal hypertensive colopathy previously and 6-12 months after splenectomy and gastric devascularization. Methods Twelve patients with hepatosplenic schistosomiasis who also had upper gastrointestinal bleeding were studied prospectively. Their endoscopic findings before and 6-12 months after the surgery were analysed. In addition, mucosal biopsies from ascending colon, sigmoid colon and rectum at these time points were subjected to histological and histomorphometric assessment. It was used a control group due to lack of normal pattern of the histomorphometric measures of vessels in individuals without portal hypertension. The critical level of significance adopted in all tests was of a maximum probability error of 5%. Results Surgery did not lead to significant improvement in histological and endoscopic findings. However, on histomorphometry, there was a significant decrease in the area, diameter and thickness of the vessels in mucosa at all colonic sites. Conclusion Surgery for decompression of schistosomal portal hypertension has a beneficial effect on the associated colopathy, being best indicated in patients with gastrointestinal bleeding and esophageal varices.

Large-area formation of self-aligned crystalline domains of organic semiconductors on transistor channels using CONNECT

Science.gov (United States)

Park, Steve; Giri, Gaurav; Shaw, Leo; Pitner, Gregory; Ha, Jewook; Koo, Ja Hoon; Gu, Xiaodan; Park, Joonsuk; Lee, Tae Hoon; Nam, Ji Hyun; Hong, Yongtaek; Bao, Zhenan

2015-01-01

The electronic properties of solution-processable small-molecule organic semiconductors (OSCs) have rapidly improved in recent years, rendering them highly promising for various low-cost large-area electronic applications. However, practical applications of organic electronics require patterned and precisely registered OSC films within the transistor channel region with uniform electrical properties over a large area, a task that remains a significant challenge. Here, we present a technique termed “controlled OSC nucleation and extension for circuits” (CONNECT), which uses differential surface energy and solution shearing to simultaneously generate patterned and precisely registered OSC thin films within the channel region and with aligned crystalline domains, resulting in low device-to-device variability. We have fabricated transistor density as high as 840 dpi, with a yield of 99%. We have successfully built various logic gates and a 2-bit half-adder circuit, demonstrating the practical applicability of our technique for large-scale circuit fabrication. PMID:25902502

Solution coating of large-area organic semiconductor thin films with aligned single-crystalline domains

KAUST Repository

Diao, Ying; Tee, Benjamin C-K.; Giri, Gaurav; Xu, Jie; Kim, Do Hwan; Becerril, Hector A.; Stoltenberg, Randall M.; Lee, Tae Hoon; Xue, Gi; Mannsfeld, Stefan C. B.; Bao, Zhenan

2013-01-01

Solution coating of organic semiconductors offers great potential for achieving low-cost manufacturing of large-area and flexible electronics. However, the rapid coating speed needed for industrial-scale production poses challenges to the control

Colangiopatía portal: complicación poco frecuente de la hipertensión portal

OpenAIRE

Veloso, Victoria; Servente, Liliana; Hernández, Nelia

2017-01-01

Resumen: Se describe el caso clínico de una mujer de 62 años en la que se diagnostica una estenosis del colédoco en el contexto de hipertensión portal prehepática (cavernomatosis portal). Abstract: We report the case of a 62 years old woman with a choledochal stricture and chronic obstruction of the portal vein (portal cavernomatosis). Resumo: Relatamos o caso de uma mulher de 62 anos com diagnóstico de estenose do colédoco no contexto da hipertensão portal pré-hepática (cavernomat...

A Prototype Large Area Detector Module for Muon Scattering Tomography

Energy Technology Data Exchange (ETDEWEB)

Steer, C.A.; Boakes, J.; Burns, J.; Snow, S.; Stapleton, M.; Thompson, L.F.; Quillin, S. [AWE Aldermaston, Reading, Berkshire, RG7 4PR (United Kingdom)

2015-07-01

Abstract-Shielded special nuclear materials (SNM) are of concern as some fissile isotopes have low gamma and neutron emission rates. These materials are also easily shielded to the point where their passive emissions are comparable to background. Consequently, shielded SNM is very challenging for passive radiation detection portals which scan cargo containers. One potential solution for this is to utilise the natural cosmic ray muon background and examine how these muons scatter from materials inside the container volume, terms; the muon scattering tomography (MST) technique measures the three-dimensional localised scattering at all points within a cargo container, providing a degree of material discrimination. There is the additional benefit that the MST signal increases with the presence of more high density shielding materials, in contrast to passive radiation detection. Simulations and calculations suggest that the effectiveness of the technique is sensitive to the tracking accuracy amongst other parameters, motivating the need to develop practical detector systems that are capable of tracking cosmic ray muons. To this end, we have constructed and tested a 2 m by 2 m demonstration module based on gaseous drift chambers and triggered by a large area scintillator-based detector, which is readout by wavelength shifting fibres. We discuss its design, construction, characterisation and operational challenges. (authors)

False-positive liver scans due to portal hypertension: correlation with percutaneous transhepatic portograms in 33 patients

International Nuclear Information System (INIS)

Takayasu, K.; Moriyama, N.; Suzuki, M.; Yamada, T.; Fukutake, T.; Shima, Y.; Kobayashi, C.; Musha, H.; Okuda, K.

1983-01-01

Tc-99m-phytate scanning of the liver and percutaneous transhepatic catheterization of the portal vein were performed in 33 patients--26 with cirrhosis, 3 with chronic active hepatitis, 2 with idiopathic portal hypertension, and 2 with unresolved acute hepatitis. A discrete defect in the porta hepatis area was seen in 6 of 28 patients who had portal vein pressure above 200 mm H2O. In 5 of the 6 patients with a false-positive scan, the umbilical portion of the left portal vein branch was dilated (larger than 25 x 20 mm) on the portogram, with or without a patent paraumbilical vein. The anatomical basis of this phenomenon is discussed, and it is suggested that this area be given special attention

The XCAT Science Portal

Directory of Open Access Journals (Sweden)

Sriram Krishnan

2002-01-01

Full Text Available This paper describes the design and prototype implementation of the XCAT Grid Science Portal. The portal lets grid application programmers script complex distributed computations and package these applications with simple interfaces for others to use. Each application is packaged as a notebook which consists of web pages and editable parameterized scripts. The portal is a workstation-based specialized personal web server, capable of executing the application scripts and launching remote grid applications for the user. The portal server can receive event streams published by the application and grid resource information published by Network Weather Service (NWS [35] or Autopilot [16] sensors. Notebooks can be published and stored in web based archives for others to retrieve and modify. The XCAT Grid Science Portal has been tested with various applications, including the distributed simulation of chemical processes in semiconductor manufacturing and collaboratory support for X-ray crystallographers.

Supporting the education evidence portal via text mining

Science.gov (United States)

Ananiadou, Sophia; Thompson, Paul; Thomas, James; Mu, Tingting; Oliver, Sandy; Rickinson, Mark; Sasaki, Yutaka; Weissenbacher, Davy; McNaught, John

2010-01-01

The UK Education Evidence Portal (eep) provides a single, searchable, point of access to the contents of the websites of 33 organizations relating to education, with the aim of revolutionizing work practices for the education community. Use of the portal alleviates the need to spend time searching multiple resources to find relevant information. However, the combined content of the websites of interest is still very large (over 500 000 documents and growing). This means that searches using the portal can produce very large numbers of hits. As users often have limited time, they would benefit from enhanced methods of performing searches and viewing results, allowing them to drill down to information of interest more efficiently, without having to sift through potentially long lists of irrelevant documents. The Joint Information Systems Committee (JISC)-funded ASSIST project has produced a prototype web interface to demonstrate the applicability of integrating a number of text-mining tools and methods into the eep, to facilitate an enhanced searching, browsing and document-viewing experience. New features include automatic classification of documents according to a taxonomy, automatic clustering of search results according to similar document content, and automatic identification and highlighting of key terms within documents. PMID:20643679

Anatomy of the Portal Vein Bifurcation: Implication for Transjugular Intrahepatic Portal Systemic Shunts

International Nuclear Information System (INIS)

Kwok, Philip Chong-hei; Ng, Wai Fu; Lam, Christine Suk-yee; Tsui, Polly Po; Faruqi, Asma

2003-01-01

Purpose: The relationship of the portalvein bifurcation to the liver capsule in Asians, which is an important landmark for transjugular intrahepatic portosystemic shunt, has not previously been described. Methods: The anatomy of the portal vein bifurcation was studied in 70 adult Chinese cadavers; it was characterized as intrahepatic or extrahepatic. The length of the exposed portion of the right and left portal veins was measured when the bifurcation was extrahepatic. Results: The portal vein bifurcation was intrahepatic in 37 cadavers (53%) and extrahepatic in 33 cadavers (47%). The mean length of the right and left extrahepatic portal veins was 0.96 cm and 0.85 cm respectively.Both were less than or equal to 2 cm in 94% of the cadavers with extrahepatic bifurcation. There was no correlation between the presence of cirrhosis and the location of the portal vein bifurcation(p 1.0). There was no statistically significant difference in liver mass in cadavers with either extrahepatic or intrahepatic bifurcation (p =0.40). Conclusions: These findings suggest that fortransjugular intrahepatic portosystemic shunt placement, a portal vein puncture 2 cm from the bifurcation will be safe in most cases

The application of TIPSS in portal vein cancerous thrombosis complicated with portal hypertension

International Nuclear Information System (INIS)

Jiang Zaibo; Shan Hong; Guan Shouhai; Zhu Kangshun; Huang Mingsheng; Li Zhengran; Zhu Wenke; Liu Lang; Guo Tiansheng

2002-01-01

Objective: To discuss the technical skills and the contraindication of trans-jugular intrahepatic portosystemic shunt stent (TIPSS) in portal vein cancerous thrombosis (PVCT) complicated with portal hypertension. Methods: There were 16 cases of PVCT with portal hypertension, and average age of 53.6 yr. There were 9 cases with complete occlusion of portal vein trunk and 7 cases with incomplete thrombosis. There were 5 cases with cavernous transformation of the portal vein (CTPV). 1 case of simple upper gastro-intestinal tract (GIT) massive bleeding, 4 with refractory ascites and 11 with upper GIT massive bleeding and refractory ascites. Results: The procedure of TIPS was successful in 11 cases, the successful rate reached about 68.8%. The mean portal vein pressure was reduced from 4.9 kPa to 2.4 kPa with average 2. 5 kPa reduction. Ascites decreased, bleeding stopped and the clinical symptoms disappeared. The average survival period was 136 days. The procedure failed in 5 cases. Conclusions: TIPSS is an effective method to control the bleeding and ascites caused by PVCT. The PV cavernous transformation was the contraindication of TIPSS

Large-Area Synthesis of High-Quality Uniform Few-Layer MoTe2.

Science.gov (United States)

Zhou, Lin; Xu, Kai; Zubair, Ahmad; Liao, Albert D; Fang, Wenjing; Ouyang, Fangping; Lee, Yi-Hsien; Ueno, Keiji; Saito, Riichiro; Palacios, Tomás; Kong, Jing; Dresselhaus, Mildred S

2015-09-23

The controlled synthesis of large-area, atomically thin molybdenum ditelluride (MoTe2) crystals is crucial for its various applications based on the attractive properties of this emerging material. In this work, we developed a chemical vapor deposition synthesis to produce large-area, uniform, and highly crystalline few-layer 2H and 1T' MoTe2 films. It was found that these two different phases of MoTe2 can be grown depending on the choice of Mo precursor. Because of the highly crystalline structure, the as-grown few-layer 2H MoTe2 films display electronic properties that are comparable to those of mechanically exfoliated MoTe2 flakes. Our growth method paves the way for the large-scale application of MoTe2 in high-performance nanoelectronics and optoelectronics.

The NOAO NVO Portal

Science.gov (United States)

Miller, C. J.; Gasson, D.; Fuentes, E.

2007-10-01

The NOAO NVO Portal is a web application for one-stop discovery, analysis, and access to VO-compliant imaging data and services. The current release allows for GUI-based discovery of nearly a half million images from archives such as the NOAO Science Archive, the Hubble Space Telescope WFPC2 and ACS instruments, XMM-Newton, Chandra, and ESO's INT Wide-Field Survey, among others. The NOAO Portal allows users to view image metadata, footprint wire-frames, FITS image previews, and provides one-click access to science quality imaging data throughout the entire sky via the Firefox web browser (i.e., no applet or code to download). Users can stage images from multiple archives at the NOAO NVO Portal for quick and easy bulk downloads. The NOAO NVO Portal also provides simplified and direct access to VO analysis services, such as the WESIX catalog generation service. We highlight the features of the NOAO NVO Portal (http://nvo.noao.edu).

Feasibility study using a Ni-Ti stent and electronic portal imaging to localize the prostate during radiotherapy.

Science.gov (United States)

Carl, Jesper; Lund, Bente; Larsen, Erik Hoejkjaer; Nielsen, Jane

2006-02-01

A new method for localization of the prostate during external beam radiotherapy is presented. The method is based on insertion of a thermo-expandable Ni-Ti stent. The stent is originally developed for treatment of bladder outlet obstruction caused by benign hyperplasia. The radiological properties of the stent are used for precise prostate localization during treatment using electronic portal images. Patients referred for intended curative radiotherapy and having a length of their prostatic urethra in the range from 25 to 65 mm were included. Pairs of isocentric orthogonal portal images were used to determine the 3D position at eight different treatment sessions for each patient. Fourteen patients were enrolled in the study. The data obtained demonstrated that the stent position was representative of the prostate location. The stent may also improve delineation of the prostate GTV, and prevent obstruction of bladder outlet during treatment. Precision in localization of the stent was less than 1 mm. Random errors in stent position were left-right 1.6 mm, cranial-caudal 2.2 mm and anterior-posterior 3.2 mm. In four of 14 patients a dislocation of the stent to the bladder occurred. Dislocation only occurred in patients with length of prostatic urethra less than 40 mm. A new method for radiological high precision localization of the prostate during radiotherapy is presented. The method is based on insertion of a standard Ni-Ti thermo-expandable stent, designed for treatment of benign prostate hyperplasia.

Design and Implementation of a Portal for the Medical Equipment Market: MEDICOM

Science.gov (United States)

Kalivas, Dimitris; Panou-Diamandi, Ourania; Zeelenberg, Cees; van Nimwegen, Chris

2001-01-01

Background The MEDICOM (Medical Products Electronic Commerce) Portal provides the electronic means for medical-equipment manufacturers to communicate online with their customers while supporting the Purchasing Process and Post Market Surveillance. The Portal offers a powerful Internet-based search tool for finding medical products and manufacturers. Its main advantage is the fast, reliable and up-to-date retrieval of information while eliminating all unrelated content that a general-purpose search engine would retrieve. The Universal Medical Device Nomenclature System (UMDNS) registers all products. The Portal accepts end-user requests and generates a list of results containing text descriptions of devices, UMDNS attribute values, and links to manufacturer Web pages and online catalogues for access to more-detailed information. Device short descriptions are provided by the corresponding manufacturer. The Portal offers technical support for integration of the manufacturers' Web sites with itself. The network of the Portal and the connected manufacturers' sites is called the MEDICOM system. Objective To establish an environment hosting all the interactions of consumers (health care organizations and professionals) and providers (manufacturers, distributors, and resellers of medical devices). Methods The Portal provides the end-user interface, implements system management, and supports database compatibility. The Portal hosts information about the whole MEDICOM system (Common Database) and summarized descriptions of medical devices (Short Description Database); the manufacturers' servers present extended descriptions. The Portal provides end-user profiling and registration, an efficient product-searching mechanism, bulletin boards, links to on-line libraries and standards, on-line information for the MEDICOM system, and special messages or advertisements from manufacturers. Platform independence and interoperability characterize the system design. Relational Database

Design and implementation of a portal for the medical equipment market: MEDICOM.

Science.gov (United States)

Palamas, S; Kalivas, D; Panou-Diamandi, O; Zeelenberg, C; van Nimwegen, C

2001-01-01

The MEDICOM (Medical Products Electronic Commerce) Portal provides the electronic means for medical-equipment manufacturers to communicate online with their customers while supporting the Purchasing Process and Post Market Surveillance. The Portal offers a powerful Internet-based search tool for finding medical products and manufacturers. Its main advantage is the fast, reliable and up-to-date retrieval of information while eliminating all unrelated content that a general-purpose search engine would retrieve. The Universal Medical Device Nomenclature System (UMDNS) registers all products. The Portal accepts end-user requests and generates a list of results containing text descriptions of devices, UMDNS attribute values, and links to manufacturer Web pages and online catalogues for access to more-detailed information. Device short descriptions are provided by the corresponding manufacturer. The Portal offers technical support for integration of the manufacturers Web sites with itself. The network of the Portal and the connected manufacturers sites is called the MEDICOM system. To establish an environment hosting all the interactions of consumers (health care organizations and professionals) and providers (manufacturers, distributors, and resellers of medical devices). The Portal provides the end-user interface, implements system management, and supports database compatibility. The Portal hosts information about the whole MEDICOM system (Common Database) and summarized descriptions of medical devices (Short Description Database); the manufacturers servers present extended descriptions. The Portal provides end-user profiling and registration, an efficient product-searching mechanism, bulletin boards, links to on-line libraries and standards, on-line information for the MEDICOM system, and special messages or advertisements from manufacturers. Platform independence and interoperability characterize the system design. Relational Database Management Systems are used for

Sharing Physician Notes Through an Electronic Portal is Associated With Improved Medication Adherence: Quasi-Experimental Study

OpenAIRE

Wright, Eric; Darer, Jonathan; Tang, Xiaoqin; Thompson, Jason; Tusing, Lorraine; Fossa, Alan; Delbanco, Tom; Ngo, Long; Walker, Jan

2015-01-01

Background In surveys, interviews, and focus groups, patients taking medications and offered Web portal access to their primary care physicians? (PCPs) notes report improved adherence to their regimens. However, objective confirmation has yet to be reported. Objective To evaluate the association between patient Internet portal access to primary care physician visit notes and medication adherence. Methods This study is a retrospective comparative analysis at one site of the OpenNotes quasi-exp...

Customizable scientific web-portal for DIII-D nuclear fusion experiment

Energy Technology Data Exchange (ETDEWEB)

Abla, G; Kim, E N; Schissel, D P, E-mail: abla@fusion.gat.co [General Atomics, PO Box 85608, San Diego, California 92186-5608 (United States)

2010-04-01

Increasing utilization of the Internet and convenient web technologies has made the web-portal a major application interface for remote participation and control of scientific instruments. While web-portals have provided a centralized gateway for multiple computational services, the amount of visual output often is overwhelming due to the high volume of data generated by complex scientific instruments and experiments. Since each scientist may have different priorities and areas of interest in the experiment, filtering and organizing information based on the individual user's need can increase the usability and efficiency of a web-portal. DIII-D is the largest magnetic nuclear fusion device in the US. A web-portal has been designed to support the experimental activities of DIII-D researchers worldwide. It offers a customizable interface with personalized page layouts and list of services for users to select. Each individual user can create a unique working environment to fit his own needs and interests. Customizable services are: real-time experiment status monitoring, diagnostic data access, interactive data analysis and visualization. The web-portal also supports interactive collaborations by providing collaborative logbook, and online instant announcement services. The DIII-D web-portal development utilizes multi-tier software architecture, and Web 2.0 technologies and tools, such as AJAX and Django, to develop a highly-interactive and customizable user interface.

Customizable scientific web-portal for DIII-D nuclear fusion experiment

International Nuclear Information System (INIS)

Abla, G; Kim, E N; Schissel, D P

2010-01-01

Increasing utilization of the Internet and convenient web technologies has made the web-portal a major application interface for remote participation and control of scientific instruments. While web-portals have provided a centralized gateway for multiple computational services, the amount of visual output often is overwhelming due to the high volume of data generated by complex scientific instruments and experiments. Since each scientist may have different priorities and areas of interest in the experiment, filtering and organizing information based on the individual user's need can increase the usability and efficiency of a web-portal. DIII-D is the largest magnetic nuclear fusion device in the US. A web-portal has been designed to support the experimental activities of DIII-D researchers worldwide. It offers a customizable interface with personalized page layouts and list of services for users to select. Each individual user can create a unique working environment to fit his own needs and interests. Customizable services are: real-time experiment status monitoring, diagnostic data access, interactive data analysis and visualization. The web-portal also supports interactive collaborations by providing collaborative logbook, and online instant announcement services. The DIII-D web-portal development utilizes multi-tier software architecture, and Web 2.0 technologies and tools, such as AJAX and Django, to develop a highly-interactive and customizable user interface.

Customizable scientific web-portal for DIII-D nuclear fusion experiment

Science.gov (United States)

Abla, G.; Kim, E. N.; Schissel, D. P.

2010-04-01

Increasing utilization of the Internet and convenient web technologies has made the web-portal a major application interface for remote participation and control of scientific instruments. While web-portals have provided a centralized gateway for multiple computational services, the amount of visual output often is overwhelming due to the high volume of data generated by complex scientific instruments and experiments. Since each scientist may have different priorities and areas of interest in the experiment, filtering and organizing information based on the individual user's need can increase the usability and efficiency of a web-portal. DIII-D is the largest magnetic nuclear fusion device in the US. A web-portal has been designed to support the experimental activities of DIII-D researchers worldwide. It offers a customizable interface with personalized page layouts and list of services for users to select. Each individual user can create a unique working environment to fit his own needs and interests. Customizable services are: real-time experiment status monitoring, diagnostic data access, interactive data analysis and visualization. The web-portal also supports interactive collaborations by providing collaborative logbook, and online instant announcement services. The DIII-D web-portal development utilizes multi-tier software architecture, and Web 2.0 technologies and tools, such as AJAX and Django, to develop a highly-interactive and customizable user interface.

Charge reconstruction in large-area photomultipliers

Science.gov (United States)

Grassi, M.; Montuschi, M.; Baldoncini, M.; Mantovani, F.; Ricci, B.; Andronico, G.; Antonelli, V.; Bellato, M.; Bernieri, E.; Brigatti, A.; Brugnera, R.; Budano, A.; Buscemi, M.; Bussino, S.; Caruso, R.; Chiesa, D.; Corti, D.; Dal Corso, F.; Ding, X. F.; Dusini, S.; Fabbri, A.; Fiorentini, G.; Ford, R.; Formozov, A.; Galet, G.; Garfagnini, A.; Giammarchi, M.; Giaz, A.; Insolia, A.; Isocrate, R.; Lippi, I.; Longhitano, F.; Lo Presti, D.; Lombardi, P.; Marini, F.; Mari, S. M.; Martellini, C.; Meroni, E.; Mezzetto, M.; Miramonti, L.; Monforte, S.; Nastasi, M.; Ortica, F.; Paoloni, A.; Parmeggiano, S.; Pedretti, D.; Pelliccia, N.; Pompilio, R.; Previtali, E.; Ranucci, G.; Re, A. C.; Romani, A.; Saggese, P.; Salamanna, G.; Sawy, F. H.; Settanta, G.; Sisti, M.; Sirignano, C.; Spinetti, M.; Stanco, L.; Strati, V.; Verde, G.; Votano, L.

2018-02-01

Large-area PhotoMultiplier Tubes (PMT) allow to efficiently instrument Liquid Scintillator (LS) neutrino detectors, where large target masses are pivotal to compensate for neutrinos' extremely elusive nature. Depending on the detector light yield, several scintillation photons stemming from the same neutrino interaction are likely to hit a single PMT in a few tens/hundreds of nanoseconds, resulting in several photoelectrons (PEs) to pile-up at the PMT anode. In such scenario, the signal generated by each PE is entangled to the others, and an accurate PMT charge reconstruction becomes challenging. This manuscript describes an experimental method able to address the PMT charge reconstruction in the case of large PE pile-up, providing an unbiased charge estimator at the permille level up to 15 detected PEs. The method is based on a signal filtering technique (Wiener filter) which suppresses the noise due to both PMT and readout electronics, and on a Fourier-based deconvolution able to minimize the influence of signal distortions—such as an overshoot. The analysis of simulated PMT waveforms shows that the slope of a linear regression modeling the relation between reconstructed and true charge values improves from 0.769 ± 0.001 (without deconvolution) to 0.989 ± 0.001 (with deconvolution), where unitary slope implies perfect reconstruction. A C++ implementation of the charge reconstruction algorithm is available online at [1].

Realizing Large-Scale, Electronic-Grade Two-Dimensional Semiconductors.

Science.gov (United States)

Lin, Yu-Chuan; Jariwala, Bhakti; Bersch, Brian M; Xu, Ke; Nie, Yifan; Wang, Baoming; Eichfeld, Sarah M; Zhang, Xiaotian; Choudhury, Tanushree H; Pan, Yi; Addou, Rafik; Smyth, Christopher M; Li, Jun; Zhang, Kehao; Haque, M Aman; Fölsch, Stefan; Feenstra, Randall M; Wallace, Robert M; Cho, Kyeongjae; Fullerton-Shirey, Susan K; Redwing, Joan M; Robinson, Joshua A

2018-02-27

Atomically thin transition metal dichalcogenides (TMDs) are of interest for next-generation electronics and optoelectronics. Here, we demonstrate device-ready synthetic tungsten diselenide (WSe 2 ) via metal-organic chemical vapor deposition and provide key insights into the phenomena that control the properties of large-area, epitaxial TMDs. When epitaxy is achieved, the sapphire surface reconstructs, leading to strong 2D/3D (i.e., TMD/substrate) interactions that impact carrier transport. Furthermore, we demonstrate that substrate step edges are a major source of carrier doping and scattering. Even with 2D/3D coupling, transistors utilizing transfer-free epitaxial WSe 2 /sapphire exhibit ambipolar behavior with excellent on/off ratios (∼10 7 ), high current density (1-10 μA·μm -1 ), and good field-effect transistor mobility (∼30 cm 2 ·V -1 ·s -1 ) at room temperature. This work establishes that realization of electronic-grade epitaxial TMDs must consider the impact of the TMD precursors, substrate, and the 2D/3D interface as leading factors in electronic performance.

New possibilities of digital luminescence radiography (DLR) and digital image processing for verification and portal imaging

International Nuclear Information System (INIS)

Zimmermann, J.S.; Blume, J.; Wendhausen, H.; Hebbinghaus, D.; Kovacs, G.; Eilf, K.; Schultze, J.; Kimmig, B.N.

1995-01-01

We developed a method, using digital luminescence radiography (DLR), not only for portal imaging of photon beams in an excellent quality, but also for verification of electron beams. Furtheron, DLR was used as basic instrument for image fusion of portal and verification film and simulation film respectively for image processing in ''beams-eye-view'' verification (BEVV) of rotating beams or conformation therapy. Digital radiographs of an excellent quality are gained for verification of photon and electron beams. In photon beams, quality improvement vs. conventional portal imaging may be dramatic, even more for high energy beams (e.g. 15-MV-photon beams) than for Co-60. In electron beams, excellent results may be easily obtained. By digital image fusion of 1 or more verification films on simulation film or MRI-planning film, more precise judgement even on small differences between simulation and verification films becomes possible. Using BEVV, it is possible to compare computer aided simulation in rotating beams or conformation therapy with the really applied treatment. The basic principle of BEVV is also suitable for dynamic multileaf collimation. (orig.) [de

SU-E-T-438: Commissioning of An In-Vivo Quality Assurance Method Using the Electronic Portal Imaging Device

International Nuclear Information System (INIS)

Morin, O; Held, M; Pouliot, J

2014-01-01

Purpose: Patient specific pre-treatment quality assurance (QA) using arrays of detectors or film have been the standard approach to assure the correct treatment is delivered to the patient. This QA approach is expensive, labor intensive and does not guarantee or document that all remaining fractions were treated properly. The purpose of this abstract is to commission and evaluate the performance of a commercially available in-vivo QA software using the electronic portal imaging device (EPID) to record the daily treatments. Methods: The platform EPIgray V2.0.2 (Dosisoft), which machine model compares ratios of TMR with EPID signal to predict dose was commissioned for an Artiste (Siemens Oncology Care Systems) and a Truebeam (Varian medical systems) linear accelerator following the given instructions. The systems were then tested on three different phantoms (homogeneous stack of solid water, anthropomorphic head and pelvis) and on a library of patient cases. Simple and complex fields were delivered at different exposures and for different gantry angles. The effects of the table attenuation and the EPID sagging were evaluated. Gamma analysis of the measured dose was compared to the predicted dose for complex clinical IMRT cases. Results: Commissioning of the EPIgray system for two photon energies took 8 hours. The difference between the dose planned and the dose measured with EPIgray was better than 3% for all phantom scenarios tested. Preliminary results on patients demonstrate an accuracy of 5% is achievable in high dose regions for both 3DCRT and IMRT. Large discrepancies (>5%) were observed due to metallic structures or air cavities and in low dose areas. Flat panel sagging was visible and accounted for in the EPIgray model. Conclusion: The accuracy achieved by EPIgray is sufficient to document the safe delivery of complex IMRT treatments. Future work will evaluate EPIgray for VMAT and high dose rate deliveries. This work is supported by Dosisoft, Cachan, France

Evaluation of patients with portal hypertension using Tc-99m-Sn Colloid scintigraphy

International Nuclear Information System (INIS)

Khan, H.A.

1990-01-01

Thirty seven cases of portal hypertension with endoscopically proven esophageal varieces underwent liver biopsy to determine the aetiology of portal hypertension. From which 19 had cirrhosis and 18 Idiopathic Portal Hypertension. Tc-99m-Sn colloid static and dynamic scintigraphy of the liver and spleen was performed in these patients. Apart from the calculation of ratio of area (A L/S), ratio of integral (I L/S) were also computed to see if these could be used to differentiate cirrhosis from IPH. Significant difference was noted in the ratio of the area in patients and controls, but the ratios of the integral (IL/S) and the slope of the integral (SIL/S) were not only significantly different in the patients and controls but also in the two groups of patients. The sensitivity of this test when compared with histology was 58% for cirrhosis and IPH but when compared with clinical diagnosis it was 76% for cirrhosis and 62% for IPH group. Therefore, by using the above mentioned technique in the routine study of liver scintigraphy in patients with portal hypertension, the added information obtained can be used to further differentiate the cirrhotic and non cirrhotic group of portal hypertensives. (author)

A two-dimensional matrix correction for off-axis portal dose prediction errors

International Nuclear Information System (INIS)

Bailey, Daniel W.; Kumaraswamy, Lalith; Bakhtiari, Mohammad; Podgorsak, Matthew B.

2013-01-01

Purpose: This study presents a follow-up to a modified calibration procedure for portal dosimetry published by Bailey et al. [“An effective correction algorithm for off-axis portal dosimetry errors,” Med. Phys. 36, 4089–4094 (2009)]. A commercial portal dose prediction system exhibits disagreement of up to 15% (calibrated units) between measured and predicted images as off-axis distance increases. The previous modified calibration procedure accounts for these off-axis effects in most regions of the detecting surface, but is limited by the simplistic assumption of radial symmetry. Methods: We find that a two-dimensional (2D) matrix correction, applied to each calibrated image, accounts for off-axis prediction errors in all regions of the detecting surface, including those still problematic after the radial correction is performed. The correction matrix is calculated by quantitative comparison of predicted and measured images that span the entire detecting surface. The correction matrix was verified for dose-linearity, and its effectiveness was verified on a number of test fields. The 2D correction was employed to retrospectively examine 22 off-axis, asymmetric electronic-compensation breast fields, five intensity-modulated brain fields (moderate-high modulation) manipulated for far off-axis delivery, and 29 intensity-modulated clinical fields of varying complexity in the central portion of the detecting surface. Results: Employing the matrix correction to the off-axis test fields and clinical fields, predicted vs measured portal dose agreement improves by up to 15%, producing up to 10% better agreement than the radial correction in some areas of the detecting surface. Gamma evaluation analyses (3 mm, 3% global, 10% dose threshold) of predicted vs measured portal dose images demonstrate pass rate improvement of up to 75% with the matrix correction, producing pass rates that are up to 30% higher than those resulting from the radial correction technique alone. As

Portal verification using the KODAK ACR 2000 RT storage phosphor plate system and EC films. A semiquantitative comparison.

Science.gov (United States)

Geyer, Peter; Blank, Hilbert; Alheit, Horst

2006-03-01

The suitability of the storage phosphor plate system ACR 2000 RT (Eastman Kodak Corp., Rochester, MN, USA), that is destined for portal verification as well as for portal simulation imaging in radiotherapy, had to be proven by the comparison with a highly sensitive verification film. The comparison included portal verification images of different regions (head and neck, thorax, abdomen, and pelvis) irradiated with 6- and 15-MV photons and electrons. Each portal verification image was done at the storage screen and the EC film as well, using the EC-L cassettes (both: Eastman Kodak Corp., Rochester, MN, USA) for both systems. The soft-tissue and bony contrast and the brightness were evaluated and compared in a ranking of the two compared images. Different phantoms were irradiated to investigate the high- and low-contrast resolution. To account for quality assurance application, the short-time exposure of the unpacked and irradiated storage screen by green and red room lasers was also investigated. In general, the quality of the processed ACR images was slightly higher than that of the films, mostly due to cases of an insufficient exposure to the film. The storage screen was able to verify electron portals even for low electron energies with only minor photon contamination. The laser lines were sharply and clearly visible on the ACR images. The ACR system may replace the film without any noticeable decrease in image quality thereby reducing processing time and saving the costs of films and avoiding incorrect exposures.

Laser Direct Write micro-fabrication of large area electronics on flexible substrates

International Nuclear Information System (INIS)

Zacharatos, F.; Makrygianni, M.; Geremia, R.; Biver, E.; Karnakis, D.; Leyder, S.; Puerto, D.; Delaporte, P.; Zergioti, I.

2016-01-01

Highlights: • Laser Direct Writing of metallic patterns with a minimum feature size of 1 μm. • Selective Laser Ablation of 50 nm thick metal films on flexible substrates. • Selective Laser sintering resulting in an electrical resistivity of 9 μΩ cm. • Laser fabrication of interdigitated electrodes for sensor applications. - Abstract: To date, Laser Direct Write (LDW) techniques, such as Laser Induced Forward Transfer (LIFT), selective laser ablation and selective laser sintering of metal nanoparticle (NP) ink layers are receiving growing attention for the printing of uniform and well-defined conductive patterns with resolution down to 10 μm. For flexible substrates in particular, selective laser sintering of such NP patterns has been widely applied, as a low temperature and high resolution process compatible with large area electronics. In this work, LDW of silver NP inks has been carried out on polyethylene-terephthalate (PET), polyethylene-naphthalate (PEN) and polyimide (PI) substrates to achieve low electrical resistivity electrodes. In more detail, high speed short pulsed (picosecond and nanosecond) lasers with repetition rates up to 1 MHz were used to print (LIFT) metal NP inks. We thus achieved uniform and continuous patterns with a minimum feature size of 1 μm and a total footprint larger than 1 cm"2. Next, the printed patterns were laser sintered with ns pulses at 532 nm over a wide laser fluence window, resulting in an electrical resistivity of 10 μΩ cm. We carried out spatial beam shaping experiments to achieve a top-hat laser intensity profile and employed selective laser ablation of thin films (thickness on the order of 100 nm) to produce silver micro-electrodes with a resolution on the order of 10 μm and a low line edge roughness. Laser sintering was combined with laser ablation to constitute a fully autonomous micro-patterning technique of metallic micro-features, with a 10 μm resolution and geometrical characteristics tuned for

Laser Direct Write micro-fabrication of large area electronics on flexible substrates

Energy Technology Data Exchange (ETDEWEB)

Zacharatos, F.; Makrygianni, M. [National Technical University of Athens, Physics Department, Zografou Campus, 15780 (Greece); Geremia, R.; Biver, E.; Karnakis, D. [Oxford Lasers Ltd, Unit 8 Moorbrook Park, Oxfordshire OX11 7HP (United Kingdom); Leyder, S.; Puerto, D.; Delaporte, P. [Aix-Marseille University, CNRS, LP3 – UMR 7341, 13288 Marseille Cedex 9 (France); Zergioti, I., E-mail: zergioti@central.ntua.gr [National Technical University of Athens, Physics Department, Zografou Campus, 15780 (Greece)

2016-06-30

Highlights: • Laser Direct Writing of metallic patterns with a minimum feature size of 1 μm. • Selective Laser Ablation of 50 nm thick metal films on flexible substrates. • Selective Laser sintering resulting in an electrical resistivity of 9 μΩ cm. • Laser fabrication of interdigitated electrodes for sensor applications. - Abstract: To date, Laser Direct Write (LDW) techniques, such as Laser Induced Forward Transfer (LIFT), selective laser ablation and selective laser sintering of metal nanoparticle (NP) ink layers are receiving growing attention for the printing of uniform and well-defined conductive patterns with resolution down to 10 μm. For flexible substrates in particular, selective laser sintering of such NP patterns has been widely applied, as a low temperature and high resolution process compatible with large area electronics. In this work, LDW of silver NP inks has been carried out on polyethylene-terephthalate (PET), polyethylene-naphthalate (PEN) and polyimide (PI) substrates to achieve low electrical resistivity electrodes. In more detail, high speed short pulsed (picosecond and nanosecond) lasers with repetition rates up to 1 MHz were used to print (LIFT) metal NP inks. We thus achieved uniform and continuous patterns with a minimum feature size of 1 μm and a total footprint larger than 1 cm{sup 2}. Next, the printed patterns were laser sintered with ns pulses at 532 nm over a wide laser fluence window, resulting in an electrical resistivity of 10 μΩ cm. We carried out spatial beam shaping experiments to achieve a top-hat laser intensity profile and employed selective laser ablation of thin films (thickness on the order of 100 nm) to produce silver micro-electrodes with a resolution on the order of 10 μm and a low line edge roughness. Laser sintering was combined with laser ablation to constitute a fully autonomous micro-patterning technique of metallic micro-features, with a 10 μm resolution and geometrical characteristics tuned for

Presentation of Austrians recommended dispersion model for tunnel portals

Energy Technology Data Exchange (ETDEWEB)

Oettl, D.; Sturm, P.; Almbauer, R. [Inst. for Internal Combustion Engines and Thermodynamics, Graz Univ. of Technology (Austria)

2004-07-01

Street tunnels in cities are often suggested as solution to avoid daily congestions but also to prevent residential areas from high noise and air pollution emissions. In case of longitudinal ventilated tunnels high pollution levels may occur in the vicinity of the portals. The dispersion of pollutants from tunnel portals is considered to differ significantly from those of other sources, such as line or point sources. To the best of the authors knowledge, there exist currently two distinct dispersion models, which are especially designed to treat dispersion from tunnel portals. Okamoto et al proposed a diagnostic wind field model, where the dispersion is modelled using a Taylor-Galerkin-Forester filter method. Oettl et al. developed a Lagrangian-type model (GRAL TM 3.5=Graz Lagrangian model Tunnel Module version 3.5), which is briefly described in the next section. (orig.)

Current status of portal vein thrombosis in Japan: Results of a questionnaire survey by the Japan Society for Portal Hypertension.

Science.gov (United States)

Kojima, Seiichiro; Watanabe, Norihito; Koizumi, Jun; Kokubu, Shigehiro; Murashima, Naoya; Matsutani, Shoichi; Obara, Katsutoshi

2018-03-01

To investigate the current status of portal vein thrombosis (PVT) in Japan, the Clinical Research Committee of the Japan Society of Portal Hypertension undertook a questionnaire survey. A questionnaire survey of 539 cases of PVT over the previous 10 years was carried out at institutions affiliated with the Board of Trustees of the Japan Society of Portal Hypertension. The most frequent underlying etiology of PVT was liver cirrhosis in 75.3% of patients. Other causes included inflammatory diseases of the hepatobiliary system and the pancreas, malignant tumors, and hematologic diseases. The most frequent site was the main trunk of the portal vein (MPV) in 70.5%, and complete obstruction of the MPV was present in 11.5%. Among the medications for PVT, danaparoid was given to 45.8%, warfarin to 26.2%, heparin to 17.3%, and anti-thrombin III to 16.9%. Observation of the course was practiced in 22.4%. Factors contributing to therapeutic efficacy were implementation of various medications, thrombi localized to either the right or left portal vein only, non-complete obstruction of the MPV and Child-Pugh class A liver function. A survival analysis showed that the prognosis was favorable with PVT disappearance regardless of treatment. The questionnaire survey showed the current status of PVT in Japan. Any appropriate medication should be given to a patient with PVT when PVT is recognized. It is necessary to compile a large amount of information and reach a consensus on safe and highly effective management of PVT. © 2017 The Japan Society of Hepatology.

Personalization Methods for Internet Portals

OpenAIRE

Barbara Dębska; Agnieszka Kubacka

2012-01-01

The article presents methods of acquiring and gathering data about users of internet portals, with particular emphasis on educational portals. Definitions, aims and tasks related to the process of personalization of e-learning portals are thoroughly discussed. So are knowledge acquisition techniques applied in personalization, especially artificial intelligence methods.

Transparent Large-Area MoS2 Phototransistors with Inkjet-Printed Components on Flexible Platforms.

Science.gov (United States)

Kim, Tae-Young; Ha, Jewook; Cho, Kyungjune; Pak, Jinsu; Seo, Jiseok; Park, Jongjang; Kim, Jae-Keun; Chung, Seungjun; Hong, Yongtaek; Lee, Takhee

2017-10-24

Two-dimensional (2D) transition-metal dichalcogenides (TMDCs) have gained considerable attention as an emerging semiconductor due to their promising atomically thin film characteristics with good field-effect mobility and a tunable band gap energy. However, their electronic applications have been generally realized with conventional inorganic electrodes and dielectrics implemented using conventional photolithography or transferring processes that are not compatible with large-area and flexible device applications. To facilitate the advantages of 2D TMDCs in practical applications, strategies for realizing flexible and transparent 2D electronics using low-temperature, large-area, and low-cost processes should be developed. Motivated by this challenge, we report fully printed transparent chemical vapor deposition (CVD)-synthesized monolayer molybdenum disulfide (MoS 2 ) phototransistor arrays on flexible polymer substrates. All the electronic components, including dielectric and electrodes, were directly deposited with mechanically tolerable organic materials by inkjet-printing technology onto transferred monolayer MoS 2 , and their annealing temperature of printed MoS 2 phototransistors exhibit excellent transparency and mechanically stable operation.

Use of a web portal among adult clinic patients seen for type 2 diabetes mellitus.

Science.gov (United States)

Coughlin, Steven S; Heboyan, Vahé; Williams, Lovoria B; Hatzigeorgiou, Christos

2018-01-01

To determine the number of adult clinic patients seen for type 2 diabetes mellitus (T2DM) at an academic medical center and to examine characteristics of those who had or had not registered for a web portal. Electronic records were reviewed to identify web portal registration by patients treated for T2DM by age, sex, race and Hispanic ethnicity, and service (General Internal Medicine, Endocrinology). A total of 1,401 patients with T2DM were seen in General Internal Medicine and Endocrinology outpatient clinics. Less than one third (32%) had registered for the web portal. Women were more likely to have registered for the web portal than men [odds ratio (OR) =1.25; 95% CI, 0.99-1.57; Pweb portal, along with those who were 56 to 60 and >66 years of age. In multivariate analysis, a statistically significant association was observed between web portal registration and General Internal Medicine clinic vs . Endocrinology clinic (OR =2.96, P18-25 years, male sex (adjusted OR =0.71, P=0.006), and Black race (OR =0.33, P<0.001). Additional research is needed to identify portal design features that improve glycemic control and interventions that will increase use of patient portals, especially among Black patients with T2DM and those with low health literacy or computer literacy.

Ligation of superior mesenteric vein and portal to splenic vein anastomosis after superior mesenteric-portal vein confluence resection during pancreaticoduodenectomy – Case report

Science.gov (United States)

Tang, Jianlin; Abbas, Jihad; Hoetzl, Katherine; Allison, David; Osman, Mahamed; Williams, Mallory; Zelenock, Gerald B.

2014-01-01

62 year old Caucasian female with pancreatic head mass abutting the superior mesenteric vein (SMV) presented with fine needle aspiration biopsy confirmed diagnosis of ductal adenocarcinoma. CT scan showed near complete obstruction of portal vein and large SMV collateral development. After 3 months of neoadjuvant therapy, her portal vein flow improved significantly, SMV collateral circulation was diminished. Pancreaticoduodenectomy (PD) and superior mesenteric portal vein (SMPV) confluence resection were performed; A saphenous vein interposition graft thrombosed immediately. The splenic vein remnant was distended and adjacent to the stump of the portal vein. Harvesting an internal jugular vein graft required extra time and using a synthetic graft posed a risk of graft thrombosis or infection. As a result, we chose to perform a direct anastomosis of the portal and splenic vein in a desperate situation. The anastomosis decompressed the mesenteric venous system, so we then ligated the SMV. The patient had an uneventful postoperative course, except transient ascites. She redeveloped ascites more than one year later. At that time a PET scan showed bilateral lung and right femur metastatic disease. She expired 15 months after PD. Conclusion The lessons we learned are (1) Before SMPV confluence resection, internal jugular vein graft should be ready for reconstruction. (2) Synthetic graft is an alternative for internal jugular vein graft. (3) Direct portal vein to SMV anastomosis can be achieved by mobilizing liver. (4) It is possible that venous collaterals secondary to SMV tumor obstruction may have allowed this patient's post-operative survival. PMID:25568802

Sonographic detection of portal venous gas

International Nuclear Information System (INIS)

Lee, Wang Yul; Lee, S. K.; Cho, O. K.

1989-01-01

Portal venous gas suggests underlying bowel disease such as strangulating intestinal obstruction and its demonstration carries with it an important implications with respect to patient management. Radiography has been the gold standard for the detection of portal venous gas. We have experienced two cases of portal venous gas diagnosed by ultrasound. Sonographic findings were floating echoes in the main portal vein and highly echogenic linear or patchy echoes within the hepatic parenchyma. Simple abdominal films of those cases failed to demonstrate gas in the portal venous system

Usability of Discovery Portals

OpenAIRE

Bulens, J.D.; Vullings, L.A.E.; Houtkamp, J.M.; Vanmeulebrouk, B.

2013-01-01

As INSPIRE progresses to be implemented in the EU, many new discovery portals are built to facilitate finding spatial data. Currently the structure of the discovery portals is determined by the way spatial data experts like to work. However, we argue that the main target group for discovery portals are not spatial data experts but professionals with limited spatial knowledge, and a focus outside the spatial domain. An exploratory usability experiment was carried out in which three discovery p...

Celiac disease as a potential cause of idiopathic portal hypertension: a case report

Directory of Open Access Journals (Sweden)

Zamani Farhad

2009-02-01

Full Text Available Abstract Introduction Idiopathic portal hypertension is a disorder of unknown etiology, clinically characterized by portal hypertension, splenomegaly and anemia secondary to hypersplenism. Case presentation A 54-year-old man was admitted to our hospital for evaluation of malaise, weight loss, abdominal swelling and lower limb edema. His paraclinical tests revealed pancytopenia, large ascites, splenomegaly and esophageal varices consistent with portal hypertension. Duodenal biopsy and serologic findings were compatible with celiac disease. His symptoms improved on a gluten-free diet, but his clinical course was further complicated with ulcerative jejunoileitis, and intestinal T-cell lymphoma. Conclusion It seems that celiac disease, by an increased immune reaction in the splenoportal axis, can result in the development of idiopathic portal hypertension in susceptible affected patients.

Large area damage testing of optics

International Nuclear Information System (INIS)

Sheehan, L.; Kozlowski, M.; Stolz, C.

1996-01-01

The damage threshold specifications for the National Ignition Facility will include a mixture of standard small-area tests and new large-area tests. During our studies of laser damage and conditioning processes of various materials we have found that some damage morphologies are fairly small and this damage does not grow with further illumination. This type of damage might not be detrimental to the laser performance. We should therefore assume that some damage can be allowed on the optics, but decide on a maximum damage allowance of damage. A new specification of damage threshold termed open-quotes functional damage thresholdclose quotes was derived. Further correlation of damage size and type to system performance must be determined in order to use this measurement, but it is clear that it will be a large factor in the optics performance specifications. Large-area tests have verified that small-area testing is not always sufficient when the optic in question has defect-initiated damage. This was evident for example on sputtered polarizer and mirror coatings where the defect density was low enough that the features could be missed by standard small- area testing. For some materials, the scale-length at which damage non-uniformities occur will effect the comparison of small-area and large-area tests. An example of this was the sub-aperture tests on KD*P crystals on the Beamlet test station. The tests verified the large-area damage threshold to be similar to that found when testing a small-area. Implying that for this KD*P material, the dominate damage mechanism is of sufficiently small scale-length that small-area testing is capable of determining the threshold. The Beamlet test station experiments also demonstrated the use of on-line laser conditioning to increase the crystals damage threshold

Percutaneous transhepatic portal vein stenting in a patient with benign non-transplant postoperative portal vein stenosis: A case report

OpenAIRE

Madhusudhan, KS; Agrawal, Nikhil; Srivastava, Deep N; Pal, Sujoy; Gupta, Arun K

2013-01-01

Extrahepatic portal vein stenosis is caused by a variety of benign and malignant diseases and results in development of symptoms due to portal hypertension. Benign post-surgical adhesions causing portal vein stenosis in non-transplant population is an uncommon etiology of portal hypertension. Endovascular treatment of such patients with angioplasty and stenting is uncommonly reported in literature. We report a case of portal hypertension caused by benign postoperative portal vein fibrosis, su...

Blood Changes after Splenectomy in Portal Hypertension. The ...

African Journals Online (AJOL)

Background: Splenectomy is a frequently performed operation for patients with portal hypertension and hypersplenism in areas endemic for schistosomiasis. Reactive thrombocytosis (RT) has been described following splenectomy. Nevertheless, data are lacking on the long term changes of platelet count and other blood ...

On line portal imaging

International Nuclear Information System (INIS)

Munro, Peter

1997-01-01

Purpose/Objective: The purpose of this presentation is to examine the various imaging devices that have been developed for portal imaging, describe some of the image registration methods that have been developed to determine geometric errors quantitatively, and discuss how portal imaging has been incorporated into clinical practice. Discussion: Verification of patient positioning has always been an important aspect of external beam radiation therapy. Over the past decade many portal imaging devices have been developed by individual investigators and most accelerator manufacturers now offer 'on-line' portal imaging systems. The commercial devices include T.V. camera-based systems, liquid ionisation chamber systems, and shortly, flat panel systems. The characteristics of these imaging systems will be discussed. In addition, other approaches such as the use of kilovoltage x-ray sources, video monitoring, and ultrasound have been proposed for improving patient positioning. Some of the advantages of these approaches will be discussed. One of the major advantages of on-line portal imaging is that many quantitative techniques have been developed to detect errors in patient positioning. The general approach is to register anatomic structures on a portal image with the same structures on a digitized simulator film. Once the anatomic structures have been registered, any discrepancies in the position of the patient can be identified. One problem is finding a common frame of reference for the simulator and portal images, since the location of the radiation field within the pixel matrix may differ for the two images. As a result, a common frame of reference has to be established before the anatomic structures in the images can be registered - generally by registering radiation field edges identified in the simulator and portal images. In addition, distortions in patient geometry or rotations out of the image plane can confound the image registration techniques. Despite the

Quantitative vs. subjective portal verification using digital portal images.

Science.gov (United States)

Bissett, R; Leszczynski, K; Loose, S; Boyko, S; Dunscombe, P

1996-01-15

Off-line, computer-aided prescription (simulator) and treatment (portal) image registration using chamfer matching has been implemented on PC based viewing station. The purposes of this study were (a) to evaluate the performance of interactive anatomy and field edge extraction and subsequent registration, and (b) to compare observer's perceptions of field accuracy with measured discrepancies following anatomical registration. Prescription-treatment image pairs for 48 different patients were examined in this study. Digital prescription images were produced with the aid of a television camera and a digital frame grabber, while the treatment images were obtained directly from an on-line portal imaging system. To facilitate perception of low contrast anatomical detail, on-line portal images were enhanced with selective adaptive histogram equalization prior to extraction of anatomical edges. Following interactive extraction of anatomical and field border information by an experienced observer, the identified anatomy was registered using chamfer matching. The degree of conformity between the prescription and treatment fields was quantified using several parameters, which included relative prescription field coverage and overcoverage, as well as the translational and rotational displacements as measured by chamfer matching applied to the boundaries of the two fields. These quantitative measures were compared with subjective evaluations made by four radiation oncologists. All the images in this series that included a range of the most commonly seen treatment sites were registered and the conformity parameters were found. The mean treatment/prescription field coverage and overcoverage were approximately 95 and 7%, respectively before registration. The mean translational displacement in the transverse and cranio-caudal directions were 2.9 and 3.4 mm, respectively. The mean rotational displacement was approximately 2 degrees. For all four oncologists, the portals classified

Design and Initial Tests of the Tracker-Converter ofthe Gamma-ray Large Area Space Telescope

Energy Technology Data Exchange (ETDEWEB)

Atwood, W.B.; Bagagli, R.; Baldini, L.; Bellazzini, R.; Barbiellini, G.; Belli, F.; Borden, T.; Brez, A.; Brigida, M.; Caliandro, G.A.; Cecchi, C.; Cohen-Tanugi, J.; De; Drell, P.; Favuzzi, C.; Fukazawa, Y.; Fusco, P.; Gargano, F.; Germani, S.; Giannitrapani, R.; Giglietto, N.; /UC, Santa Cruz /INFN, Pisa /Pisa U. /INFN, Trieste /INFN,

2007-04-16

The Tracker subsystem of the Large Area Telescope (LAT) science instrument of the Gamma-ray Large Area Space Telescope (GLAST) mission has been completed and tested. It is the central detector subsystem of the LAT and serves both to convert an incident gamma-ray into an electron-positron pair and to track the pair in order to measure the gamma-ray direction. It also provides the principal trigger for the LAT. The Tracker uses silicon strip detectors, read out by custom electronics, to detect charged particles. The detectors and electronics are packaged, along with tungsten converter foils, in 16 modular, high-precision carbon-composite structures. It is the largest silicon-strip detector system ever built for launch into space, and its aggressive design emphasizes very low power consumption, passive cooling, low noise, high efficiency, minimal dead area, and a structure that is highly transparent to charged particles. The test program has demonstrated that the system meets or surpasses all of its performance specifications as well as environmental requirements. It is now installed in the completed LAT, which is being prepared for launch in early 2008.

Strategi Branding Portal Online Www.tripriau.com Dalam Membangun Brand Awareness Sebagai Portal Online Pariwisata Provinsi Riau

OpenAIRE

Rahmadhani, Yuri; Lubis, Evawani Elysa

2017-01-01

Online portal www.tripriau.com online portal is one of the online portal in Riau Province that has its own uniqueness. These portals contain local content and the potential of tourism in the province of Riau. Since its establishment, www.tripriau.com do branding strategy in order to build brand awareness or trust the reader to be known as a tourism-themed online portal. As the selection of brand name Trip Riau, Riau Guide My tagline, as well as the implementation of travel instagram photo con...

Palliative treatment of TIPS to portal vein tumor thrombosis complicated with portal vein hypertension

International Nuclear Information System (INIS)

Jiang Zaibo; Shan Hong; Guan Shouhai; Zhu Kangshun; Huang Mingsheng; Li Zhengran; Guo Tiansheng; Liu Lang

2002-01-01

Objective: To evaluate the palliative therapeutic effects of transjugular intrahepatic portosystemic shunt (TIPS) in portal vein tumor thrombosis (PVTT) complicated with portal vein hypertension, and to discuss the technical skills. Methods: There were 14 cases of end-stage hepatocellular carcinoma complicated with PVTT and portal vein hypertension, the average age was 53.6 yr. There were 8 cases with complete occlusion of main portal vein, 6 eases with incomplete thrombosis, and 5 cases combined with portal vein cavernous transformation. One case had simple hemorrhage, 3 eases had intractable ascites, and 10 cases had hemorrhage accompanied by intractable ascites. Results: The procedure of TIPS was successful in 10 cases, the successful rate was about 71%. The mean portal vein pressure was reduced from 37.2 mm Hg to 18.2 mm Hg, with an average reduction of 19.0 mm Hg. After the procedure of TIPS, the ascites decreased, hemorrhage stopped and the clinical symptoms disappeared. The average survival period was 132.3 days. The procedure were failing in 4 cases. Conclusion: TIPS was an effective palliative therapeutic methods to control the hemorrhage and ascites aroused by hepatic carcinoma complicated with PVTT

The DIRAC Web Portal 2.0

Science.gov (United States)

Mathe, Z.; Casajus Ramo, A.; Lazovsky, N.; Stagni, F.

2015-12-01

For many years the DIRAC interware (Distributed Infrastructure with Remote Agent Control) has had a web interface, allowing the users to monitor DIRAC activities and also interact with the system. Since then many new web technologies have emerged, therefore a redesign and a new implementation of the DIRAC Web portal were necessary, taking into account the lessons learnt using the old portal. These new technologies allowed to build a more compact, robust and responsive web interface that enables users to have better control over the whole system while keeping a simple interface. The web framework provides a large set of “applications”, each of which can be used for interacting with various parts of the system. Communities can also create their own set of personalised web applications, and can easily extend already existing ones with a minimal effort. Each user can configure and personalise the view for each application and save it using the DIRAC User Profile service as RESTful state provider, instead of using cookies. The owner of a view can share it with other users or within a user community. Compatibility between different browsers is assured, as well as with mobile versions. In this paper, we present the new DIRAC Web framework as well as the LHCb extension of the DIRAC Web portal.

Large scale oil lease automation and electronic custody transfer

International Nuclear Information System (INIS)

Price, C.R.; Elmer, D.C.

1995-01-01

Typically, oil field production operations have only been automated at fields with long term production profiles and enhanced recovery. The automation generally consists of monitoring and control at the wellhead and centralized facilities. However, Union Pacific Resources Co. (UPRC) has successfully implemented a large scale automation program for rapid-decline primary recovery Austin Chalk wells where purchasers buy and transport oil from each individual wellsite. This project has resulted in two significant benefits. First, operators are using the system to re-engineer their work processes. Second, an inter-company team created a new electronic custody transfer method. This paper will describe: the progression of the company's automation objectives in the area; the field operator's interaction with the system, and the related benefits; the research and development of the new electronic custody transfer method

Intrahepatic portal-hepatic venous shunt diagnosed by ultrasonography and computed tomography. Report of two cases

Energy Technology Data Exchange (ETDEWEB)

Shinagawa, Takashi; Iino, Yasuo; Ukaji, Haruyasu; Ishizuka, Masaharu

1986-02-01

Two cases of intrahepatic portal-hepatic venous shunt found by ultrasonography and computed tomography are reported. The first case came to the hospital because of hematuria. A large shunt between the portal vein and the hepatic vein was demonstrated by ultrasonography done for screening, and confirmed by percutaneous transhepatic portography (PTP). The second case was admitted because of cholelithiasis. Computed tomography with contrast enhancement revealed a dilated portal vein in the upper portion of the right lobe. It was subsequently shown by PTP to be a portal-hepatic venous shunt. Portal vein pressure and histological finding of the liver were normal in both cases. The etiology of the shunt was thought to be congenital in these cases for lack of liver disease, portal hypertension and history of trauma. Both cases had no history of hepatic encephalopathy and did not show any symptom attributable to the shunt.

Portal pressure correlated to visceral circulation times

Energy Technology Data Exchange (ETDEWEB)

Friman, L [Serafimerlasarettet, Stockholm (Sweden)

1979-01-01

Visceral angiography was performed in 7 patients with normal portal pressure and in 10 with portal hypertension. Circulation times, size of vessels and portal pressure were determined. At celiac angiography, a direct correlation was found between time for maximum filling of portal vein and portal pressure, provided no vascular abnormalities existed. At superior mesenteric angiography such a correlation was not found; loss of flow by shunts in portal hypertension being one explanation. Portocaval shunts are common in the celiac system, but uncommon in the superior mesenteric system.

Percutaneous transhepatic portal vein stenting in a patient with benign non-transplant postoperative portal vein stenosis: A case report

Directory of Open Access Journals (Sweden)

KS Madhusudhan

2013-01-01

Full Text Available Extrahepatic portal vein stenosis is caused by a variety of benign and malignant diseases and results in development of symptoms due to portal hypertension. Benign post-surgical adhesions causing portal vein stenosis in non-transplant population is an uncommon etiology of portal hypertension. Endovascular treatment of such patients with angioplasty and stenting is uncommonly reported in literature. We report a case of portal hypertension caused by benign postoperative portal vein fibrosis, successfully treated by self-expandable metallic stent.

The Modern Research Data Portal: A Design Pattern for Networked, Data-Intensive Science

Energy Technology Data Exchange (ETDEWEB)

Chard, Kyle [Univ. of Chicago, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States); Dart, Eli [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Foster, Ian [Univ. of Chicago, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States); Shifflett, David [Univ. of Chicago, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States); Tuecke, Steven [Univ. of Chicago, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States); Williams, Jason [Univ. of Chicago, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States)

2017-09-12

Here we describe best practices for providing convenient, high-speed, secure access to large data via research data portals. We capture these best practices in a new design pattern, the Modern Research Data Portal, that disaggregates the traditional monolithic web-based data portal to achieve orders-of-magnitude increases in data transfer performance, support new deployment architectures that decouple control logic from data storage, and reduce development and operations costs. We introduce the design pattern; explain how it leverages high-performance Science DMZs and cloud-based data management services; review representative examples at research laboratories and universities, including both experimental facilities and supercomputer sites; describe how to leverage Python APIs for authentication, authorization, data transfer, and data sharing; and use coding examples to demonstrate how these APIs can be used to implement a range of research data portal capabilities. Sample code at a companion web site, https://docs.globus.org/mrdp, provides application skeletons that readers can adapt to realize their own research data portals.

The SmartGeo Portal: A retrospective

Science.gov (United States)

Heilmann, Zeno; Satta, Guido; Bonomi, Ernesto

2016-04-01

The SmartGeo portal was created in a follow-up project that evolved from the geophysical data imaging services of a Grid computing portal for Geoscience, called GRIDA3. The scope of the project was to support commercial geotechnical service providers as well as academic researchers working in near-surface geoscience. Starting from the existing services, the SmartGeo portal was set up on new hardware, using the latest version of the grid portal environment EnginFrame. After a first working version was established, the services were reviewed, updated and accompanied by new services according to the feedback we received from our partners. One partner for instance experienced large difficulties in a project that aimed at delineating the aquifer for finding water pollutant substances in an industrial area of Basel. The seismic imaging service inherited from the previous portal was employing a data-driven algorithm optimized to provide, directly during data acquisition, nearly in real-time a first image of the subsurface structure. Different to this, our user needed for his data from a geologically very complex and noisy urban environment the maximum lateral resolution and noise reduction possible. For this purpose we added two cutting edge data imaging algorithms able to deliver such high precision results by simultaneously optimizing, for every single image point, all parameters of the mathematical model---a procedure which increased the computational effort by one or two magnitudes, respectively. Thus, parallel computing on grid infrastructure served for maximizing the image resolution instead for generating real-time results. This proved also very useful for the data of an academic partner, recorded for imaging the structure of a shallow sedimentary basin, where we could obtain strongly improved seismic velocity information using these new algorithms. A general user request was to implement interactive data visualization tools. To fulfill this demand we took

Portal pressure correlated to visceral circulation times

International Nuclear Information System (INIS)

Friman, L.

1979-01-01

Visceral angiography was performed in 7 patients with normal portal pressure and in 10 with portal hypertension. Circulation times, size of vessels and portal pressure were determined. At celiac angiography, a direct correlation was found between time for maximum filling of portal vein and portal pressure, provided no vascular abnormalities existed. At superior mesenteric angiography such a correlation was not found; loss of flow by shunts in portal hypertension being one explanation. Portocaval shunts are common in the celiac system, but uncommon in the superior mesenteric system. (Auth.)

Feasibility study using a Ni-Ti stent and electronic portal imaging to localize the prostate during radiotherapy

International Nuclear Information System (INIS)

Carl, Jesper; Lund, Bente; Larsen, Erik Hoejkjaer; Nielsen, Jane

2006-01-01

Background and purpose: A new method for localization of the prostate during external beam radiotherapy is presented. The method is based on insertion of a thermo-expandable Ni-Ti stent. The stent is originally developed for treatment of bladder outlet obstruction caused by benign hyperplasia. The radiological properties of the stent are used for precise prostate localization during treatment using electronic portal images. Patients and methods: Patients referred for intended curative radiotherapy and having a length of their prostatic urethra in the range from 25 to 65 mm were included. Pairs of isocentric orthogonal portal images were used to determine the 3D position at eight different treatment sessions for each patient. Results: Fourteen patients were enrolled in the study. The data obtained demonstrated that the stent position was representative of the prostate location. The stent may also improve delineation of the prostate GTV, and prevent obstruction of bladder outlet during treatment. Precision in localization of the stent was less than 1 mm. Random errors in stent position were left-right 1.6 mm, cranial-caudal 2.2 mm and anterior-posterior 3.2 mm. In four of 14 patients a dislocation of the stent to the bladder occurred. Dislocation only occurred in patients with length of prostatic urethra less than 40 mm. Conclusions: A new method for radiological high precision localization of the prostate during radiotherapy is presented. The method is based on insertion of a standard Ni-Ti thermo-expandable stent, designed for treatment of benign prostate hyperplasia

Structure-function analysis of the DNA translocating portal of the bacteriophage T4 packaging machine.

Science.gov (United States)

Padilla-Sanchez, Victor; Gao, Song; Kim, Hyung Rae; Kihara, Daisuke; Sun, Lei; Rossmann, Michael G; Rao, Venigalla B

2014-03-06

Tailed bacteriophages and herpesviruses consist of a structurally well conserved dodecameric portal at a special 5-fold vertex of the capsid. The portal plays critical roles in head assembly, genome packaging, neck/tail attachment, and genome ejection. Although the structures of portals from phages φ29, SPP1, and P22 have been determined, their mechanistic roles have not been well understood. Structural analysis of phage T4 portal (gp20) has been hampered because of its unusual interaction with the Escherichia coli inner membrane. Here, we predict atomic models for the T4 portal monomer and dodecamer, and we fit the dodecamer into the cryo-electron microscopy density of the phage portal vertex. The core structure, like that from other phages, is cone shaped with the wider end containing the "wing" and "crown" domains inside the phage head. A long "stem" encloses a central channel, and a narrow "stalk" protrudes outside the capsid. A biochemical approach was developed to analyze portal function by incorporating plasmid-expressed portal protein into phage heads and determining the effect of mutations on head assembly, DNA translocation, and virion production. We found that the protruding loops of the stalk domain are involved in assembling the DNA packaging motor. A loop that connects the stalk to the channel might be required for communication between the motor and the portal. The "tunnel" loops that project into the channel are essential for sealing the packaged head. These studies established that the portal is required throughout the DNA packaging process, with different domains participating at different stages of genome packaging. © 2013.

Portal protein functions akin to a DNA-sensor that couples genome-packaging to icosahedral capsid maturation

Energy Technology Data Exchange (ETDEWEB)

Lokareddy, Ravi K.; Sankhala, Rajeshwer S.; Roy, Ankoor; Afonine, Pavel V.; Motwani, Tina; Teschke, Carolyn M.; Parent, Kristin N.; Cingolani, Gino (Rutgers); (LBNL); (Connecticut); (TJU); (MSU)

2017-01-30

Tailed bacteriophages and herpesviruses assemble infectious particles via an empty precursor capsid (or ‘procapsid’) built by multiple copies of coat and scaffolding protein and by one dodecameric portal protein. Genome packaging triggers rearrangement of the coat protein and release of scaffolding protein, resulting in dramatic procapsid lattice expansion. Here, we provide structural evidence that the portal protein of the bacteriophage P22 exists in two distinct dodecameric conformations: an asymmetric assembly in the procapsid (PC-portal) that is competent for high affinity binding to the large terminase packaging protein, and a symmetric ring in the mature virion (MV-portal) that has negligible affinity for the packaging motor. Modelling studies indicate the structure of PC-portal is incompatible with DNA coaxially spooled around the portal vertex, suggesting that newly packaged DNA triggers the switch from PC- to MV-conformation. Thus, we propose the signal for termination of ‘Headful Packaging’ is a DNA-dependent symmetrization of portal protein.

Portal protein functions akin to a DNA-sensor that couples genome-packaging to icosahedral capsid maturation

Science.gov (United States)

Lokareddy, Ravi K.; Sankhala, Rajeshwer S.; Roy, Ankoor; Afonine, Pavel V.; Motwani, Tina; Teschke, Carolyn M.; Parent, Kristin N.; Cingolani, Gino

2017-01-01

Tailed bacteriophages and herpesviruses assemble infectious particles via an empty precursor capsid (or ‘procapsid') built by multiple copies of coat and scaffolding protein and by one dodecameric portal protein. Genome packaging triggers rearrangement of the coat protein and release of scaffolding protein, resulting in dramatic procapsid lattice expansion. Here, we provide structural evidence that the portal protein of the bacteriophage P22 exists in two distinct dodecameric conformations: an asymmetric assembly in the procapsid (PC-portal) that is competent for high affinity binding to the large terminase packaging protein, and a symmetric ring in the mature virion (MV-portal) that has negligible affinity for the packaging motor. Modelling studies indicate the structure of PC-portal is incompatible with DNA coaxially spooled around the portal vertex, suggesting that newly packaged DNA triggers the switch from PC- to MV-conformation. Thus, we propose the signal for termination of ‘Headful Packaging' is a DNA-dependent symmetrization of portal protein. PMID:28134243

Production of a large area diffuse arc plasma with multiple cathode

International Nuclear Information System (INIS)

Wang Cheng; Cui Hai-Chao; Li Wan-Wan; Liao Meng-Ran; Xia Wei-Dong; Xia Wei-Luo

2017-01-01

An arc channel at atmospheric pressure tends to shrink generally. In this paper, a non-transferred DC arc plasma device with multiple cathode is introduced to produce a large area arc plasma at atmospheric pressure. This device is comprised of a 42-mm diameter tubular chamber, multiple cathode which is radially inserted into the chamber, and a tungsten anode with a nozzle in its center. In argon/helium atmosphere, a large area and circumferential homogenous diffuse arc plasma, which fills the entire cross section surrounded by the cathode tips, is observed. Results show that the uniformity and stability of diffuse arc plasma are strongly related to the plasma forming gas. Based on these experimental results, an explanation to the arc diffusion is suggested. Moreover, the electron excitation temperature and electron density measured in diffuse helium plasma are much lower than those of constricted arc column, which indicates the diffuse helium plasma probably deviates from the local thermodynamic equilibrium state. Unlike the common non-transferred arc plasma devices, this device can provide a condition for axial-fed feedstock particles. The plasma device is attempted to spheroidize alumina powders by using the central axis to send the powder. Results show that the powder produced is usually a typical hollow sphere. (paper)

Transjugular intrahepatic portosystemic shunt in patients with active variceal bleeding due to portal hypertension and portal vein thrombosis

International Nuclear Information System (INIS)

Shin, Hyun Woong; Ryeom, Hun Kyu; Lee, Sang Kwon; Lee, Jong Min; Kim, Young Sun; Suh, Kyung Jin; Kim, Tae Hun; Kim, Yong Joo

1997-01-01

To evaluate the feasibility and efficacy of transjugular intrahepatic portosystemic shunt (TIPS) in patients with active variceal bleeding due to liver cirrhosis and pre-existing portal vein thrombosis. Of a total of 123 patients who underwent TIPS, 14 patients with intractable variceal bleeding due to portal hypertension and portal vein thrombosis were included in this study. Noncavernomatous portal vein occlusion was seen in eight patients, and complete portal vein occlusion with cavernomatous trans-formation in six. For all patients, the methods used for TIPS placement were the same as those used in patients with patents portal veins. In seven of eight patients with noncavernomatous occlusion, right hepatic vein-right portal vein shunting was performed; in one with knoncavernomatous occlusion, a shunt was created between the right hepatic and left portal vein. In five of six patients with cavernomatous occlusion, the right hepatic and main portal vein were connected via a collateral vein. The procedures were technically successful in all except one patient. Immediate hemostatis was achieved after all technically successful procedures, and no significant complications were encountered. Minor complications were noted in six patients (three biliary tree punctures, one transperitoneal puncture, one splenic vein perforation, one hepatic subcapsular hematoma). TIPS is a technically feasible and hemodynamically effective procedure, even in patients with active variceal bleeding due to cirrhosis and complete portal vein occlusion

A user-friendly web portal for T-Coffee on supercomputers

Directory of Open Access Journals (Sweden)

Koetsier Jos

2011-05-01

Full Text Available Abstract Background Parallel T-Coffee (PTC was the first parallel implementation of the T-Coffee multiple sequence alignment tool. It is based on MPI and RMA mechanisms. Its purpose is to reduce the execution time of the large-scale sequence alignments. It can be run on distributed memory clusters allowing users to align data sets consisting of hundreds of proteins within a reasonable time. However, most of the potential users of this tool are not familiar with the use of grids or supercomputers. Results In this paper we show how PTC can be easily deployed and controlled on a super computer architecture using a web portal developed using Rapid. Rapid is a tool for efficiently generating standardized portlets for a wide range of applications and the approach described here is generic enough to be applied to other applications, or to deploy PTC on different HPC environments. Conclusions The PTC portal allows users to upload a large number of sequences to be aligned by the parallel version of TC that cannot be aligned by a single machine due to memory and execution time constraints. The web portal provides a user-friendly solution.

Large area inkjet printing for organic photovoltaics and organic light emitting diodes using non-halogenated ink formulations

NARCIS (Netherlands)

Eggenhuisen, T.M.; Coenen, M.J.J.; Slaats, M.W.L.; Groen, W.A.

2014-01-01

The transfer of laboratory scale solution processing of organic electronics to large area roll-to-roll production requires the use of up-scalable deposition techniques. Furthermore, industrial production demands the omission of halogenated and other harmful solvents. Here, the authors discuss large

A chess web portal

OpenAIRE

Volf, Žiga

2011-01-01

The aim of the thesis was to develop a web portal for chess players, which is intended to be a place for quality chess joining over the Internet and chess education. This need is caused by existing social networks and websites for playing chess, which offer you a very small amount of quality chess joining and education. As a result of the work the chess portal was created. We have presented the development of the chess portal in the thesis, which has all the features the chess players are i...

Gallblader varices in children with portal cavernoma: duplex-Doppler and color Doppler ultrasound studies

International Nuclear Information System (INIS)

Muro, D.; Sanguesa, C.; Lopez, A.

1998-01-01

To determine the prevalence of varices in the gallbladder wall, observed by duplex-Doppler and color Doppler ultrasound, in children with cavernoma of the portal vein. Nineteen patients with portal hypertension were studied prospectively by duplex-Doppler and color Doppler ultrasound: 12 of the patients had developed a cavernoma of the portal vein. The presence of peri vesicular varices was assessed in the group of patients with portal cavernoma. Duplex-Doppler and color Doppler ultrasound disclosed the presence of varices in gallbladder wall in nine of the 12 patients (75%). The varices appeared as anechoic and serpiginous areas, and Doppler ultrasound revealed slowed venous flow. However, the three patients in whom gallbldder varices were not detected presented collateral gastric ciculation and spontaneous splenorenal shunt. Gallbladder varices are common in children with portal vein cavernoma; they present hepatopetal flow. Their developments is not related to the size of the portal cavernoma, the presence of spontaneous portosystemic shunts, or endoscopic obliteration of gastric and esophageal varices. The detection of gallbladder varices in patients with portal hypertension who are to undergo biliary surgery is highly important for the surgeon, helping to avoid perioperative complications. (Author) 15 refs

BSD Portals for LINUX 2.0

Science.gov (United States)

McNab, A. David; woo, Alex (Technical Monitor)

1999-01-01

Portals, an experimental feature of 4.4BSD, extend the file system name space by exporting certain open () requests to a user-space daemon. A portal daemon is mounted into the file name space as if it were a standard file system. When the kernel resolves a pathname and encounters a portal mount point, the remainder of the path is passed to the portal daemon. Depending on the portal "pathname" and the daemon's configuration, some type of open (2) is performed. The resulting file descriptor is passed back to the kernel which eventually returns it to the user, to whom it appears that a "normal" open has occurred. A proxy portalfs file system is responsible for kernel interaction with the daemon. The overall effect is that the portal daemon performs an open (2) on behalf of the kernel, possibly hiding substantial complexity from the calling process. One particularly useful application is implementing a connection service that allows simple scripts to open network sockets. This paper describes the implementation of portals for LINUX 2.0.

Predictive model of portal venous system thrombosis in cirrhotic portal hypertensive patients after splenectomy

OpenAIRE

He, Shasha; He, Fangping

2015-01-01

Objective: This study is to investigate the risk factors of portal venous system thrombosis (PVT) in patients with cirrhotic portal hypertension after splenectomy and to establish a Logistic regression prediction model. Methods: A total of 119 patients with cirrhotic portal hypertension were enrolled. Their clinical data was retrospectively analyzed. They were divided into PVT group (n = 18) and non-PVT group (n = 101). One-way analysis and multivariate Logistic regression analysis were perfo...

Quantitative vs. subjective portal verification using digital portal images

International Nuclear Information System (INIS)

Bissett, Randy; Leszczynski, Konrad; Loose, Stephen; Boyko, Susan; Dunscombe, Peter

1996-01-01

Purpose: Off-line, computer-aided prescription (simulator) and treatment (portal) image registration using chamfer matching has been implemented on PC based viewing station. The purposes of this study were (a) to evaluate the performance of interactive anatomy and field edge extraction and subsequent registration, and (b) to compare observer's perceptions of field accuracy with measured discrepancies following anatomical registration. Methods and Materials: Prescription-treatment image pairs for 48 different patients were examined in this study. Digital prescription images were produced with the aid of a television camera and a digital frame grabber, while the treatment images were obtained directly from an on-line portal imaging system. To facilitate perception of low contrast anatomical detail, on-line portal images were enhanced with selective adaptive histogram equalization prior to extraction of anatomical edges. Following interactive extraction of anatomical and field border information by an experienced observer, the identified anatomy was registered using chamber matching. The degree of conformity between the prescription and treatment fields was quantified using several parameters, which included relative prescription field coverage and overcoverage, as well as the translational and rotational displacements as measured by chamfer matching applied to the boundaries of the two fields. These quantitative measures were compared with subjective evaluations made by four radiation oncologists. Results: All the images in this series that included a range of the most commonly seen treatment sites were registered and the conformity parameters were found. The mean treatment/prescription field coverage and overcoverage were approximately 95 and 7%, respectively before registration. The mean translational displacement in the transverse and cranio-caudal directions were 2.9 and 3.4 mm, respectively. The mean rotational displacement was approximately 2 deg. . For all

Electronic and atomic impacts on large clusters

International Nuclear Information System (INIS)

Gspann, J.

1982-01-01

Describing first the generation and properties of molecular beams of large Van der Waals clusters such as speed distribution, cluster size distribution, and internal temperature of the clusters, the review then features the results of electronic impacts on large clusters: metastable electronic cluster excitations, ejection of positive cluster ions of less than 100 atoms from much larger parent clusters, and ionization of the large clusters. Atomic impacts at thermal energies are treated with respect to the scattering cross section of the clusters, their drag coefficient in free molecular flow, and the peculiarities of impacts on helium clusters of either isotope. (Auth.)

Portal monitoring technology control process

International Nuclear Information System (INIS)

York, R.L.

1998-01-01

Portal monitors are an important part of the material protection, control, and accounting (MPC and A) programs in Russia and the US. Although portal monitors are only a part of an integrated MPC and A system, they are an effective means of controlling the unauthorized movement of special nuclear material (SNM). Russian technical experts have gained experience in the use of SNM portal monitors from US experts ad this has allowed them to use the monitors more effectively. Several Russian institutes and companies are designing and manufacturing SNM portal monitors in Russia. Interactions between Russian and US experts have resulted in improvements to the instruments. SNM portal monitor technology has been effectively transferred from the US to Russia and should be a permanent part of the Russian MPC and A Program. Progress in the implementation of the monitors and improvements to how they are used are discussed

Basic dose response of fluorescent screen-based portal imaging device

International Nuclear Information System (INIS)

Yeo, In Hwan; Yonannes, Yonas; Zhu, Yunping

1999-01-01

The purpose of this study is to investigate fundamental aspects of the dose response of fluorescent screen-based electronic portal imaging devices (EPIDs). We acquired scanned signal across portal planes as we varied the radiation that entered the EPID by changing the thickness and anatomy of the phantom as well as the air gap between the phantom and the EPID. In addition, we simulated the relative contribution of the scintillation light signal in the EPID system. We have shown that the dose profile across portal planes is a function of the air gap and phantom thickness. We have also found that depending on the density change within the phantom geometry, errors associated with dose response based on the EPID scan can be as high as 7%. We also found that scintillation light scattering within the EPID system is an important source of error. This study revealed and demonstrated fundamental characteristics of dose response of EPID, as relative to that of ion chambers. This study showed that EPID based on fluorescent screen cannot be an accurate dosimetry system

Gamma portal detector with micro-processed and GSM communication system

International Nuclear Information System (INIS)

Carneiro, Lindolff Thadeu

2008-01-01

Full text: We present in this paper a new concept of gamma radiation portal detector, where the detection process is monitored by a micro-controller, coupled to a compatible GSM communication system, which is suitable to be accessed by all mobile phone operators worldwide. The signal generated at the detectors is converted by an A/D circuit, and driven to a micro-controller where a software evaluates the signal conditions and, depending on a previously set program, it triggers a communication system which sends the alarm to any computer linked to internet and/or to any mobile phone protocol by a specific software linked to the portal. The control electronic system is compatible to several detectors types, ranging from gas based devices to solid state ones. The portal is totally compatible with the ANSI - Standard N42.35 - 2004. It can be used in all types of government and industrial control scenarios. Its measure device permits the use of the equipment in all range of sensibility and in tracking radiation signals where it is. (author)

On the Efficiency of Spam Mailing and Portal Advertising

OpenAIRE

Martin Bandulet

2005-01-01

The objective of this paper is to provide a simple approach endogenizing the welfare reducing or welfare enhancing effect of informative advertising. Using this approach, it is possible to analyse the welfare consequences of a technology shock that reduces unit information costs, and to explain whether electronic junk mails or portal advertising will cause welfare gains or losses in a competitive environment.

Large area, low cost space solar cells with optional wraparound contacts

Science.gov (United States)

Michaels, D.; Mendoza, N.; Williams, R.

1981-01-01

Design parameters for two large area, low cost solar cells are presented, and electron irradiation testing, thermal alpha testing, and cell processing are discussed. The devices are a 2 ohm-cm base resistivity silicon cell with an evaporated aluminum reflector produced in a dielectric wraparound cell, and a 10 ohm-cm silicon cell with the BSF/BSR combination and a conventional contact system. Both cells are 5.9 x 5.9 cm and require 200 micron thick silicon material due to mission weight constraints. Normalized values for open circuit voltage, short circuit current, and maximum power calculations derived from electron radiation testing are given. In addition, thermal alpha testing values of absorptivity and emittance are included. A pilot cell processing run produced cells averaging 14.4% efficiencies at AMO 28 C. Manufacturing for such cells will be on a mechanized process line, and the area of coverslide application technology must be considered in order to achieve cost effective production.

Portal control of viral prohead expansion and DNA packaging

International Nuclear Information System (INIS)

Ray, Krishanu; Oram, Mark; Ma, Jinxia; Black, Lindsay W.

2009-01-01

Bacteriophage T4 terminase packages DNA in vitro into empty small or large proheads (esps or elps). In vivo maturation of esps yields the more stable and voluminous elps required to contain the 170 kb T4 genome. Functional proheads can be assembled containing portal-GFP fusion proteins. In the absence of terminase activity these accumulated in esps in vivo, whereas wild-type portals were found in elps. By nuclease protection assay dsDNAs of lengths 0.1, 0.2, 0.5, 5, 11, 20, 40 or 170 kb were efficiently packaged into wild-type elps in vitro, but less so into esps and gp20-GFP elps; particularly with DNAs shorter than 11 kb. However, 0.1 kb substrates were equally efficiently packaged into all types of proheads as judged by fluorescence correlation spectroscopy. These data suggest the portal controls the expansion of the major capsid protein lattice during prohead maturation, and that this expansion is necessary for DNA protection but not for packaging.

Direct interaction of the bacteriophage SPP1 packaging ATPase with the portal protein.

Science.gov (United States)

Oliveira, Leonor; Cuervo, Ana; Tavares, Paulo

2010-03-05

DNA packaging in tailed bacteriophages and other viruses requires assembly of a complex molecular machine at a specific vertex of the procapsid. This machine is composed of the portal protein that provides a tunnel for DNA entry, an ATPase that fuels DNA translocation (large terminase subunit), and most frequently, a small terminase subunit. Here we characterized the interaction between the terminase ATPase subunit of bacteriophage SPP1 (gp2) and the procapsid portal vertex. We found, by affinity pulldown assays with purified proteins, that gp2 interacts with the portal protein, gp6, independently of the terminase small subunit gp1, DNA, or ATP. The gp2-procapsid interaction via the portal protein depends on gp2 concentration and requires the presence of divalent cations. Competition experiments showed that isolated gp6 can only inhibit gp2-procapsid interactions and DNA packaging at gp6:procapsid molar ratios above 10-fold. Assays with gp6 carrying mutations in distinct regions of its structure that affect the portal-induced stimulation of ATPase and DNA packaging revealed that none of these mutations impedes gp2-gp6 binding. Our results demonstrate that the SPP1 packaging ATPase binds directly to the portal and that the interaction is stronger with the portal embedded in procapsids. Identification of mutations in gp6 that allow for assembly of the ATPase-portal complex but impair DNA packaging support an intricate cross-talk between the two proteins for activity of the DNA translocation motor.

In situ catalytic growth of large-area multilayered graphene/MoS2 heterostructures

Science.gov (United States)

Fu, Wei; Du, Fei-Hu; Su, Juan; Li, Xin-Hao; Wei, Xiao; Ye, Tian-Nan; Wang, Kai-Xue; Chen, Jie-Sheng

2014-04-01

Stacking various two-dimensional atomic crystals on top of each other is a feasible approach to create unique multilayered heterostructures with desired properties. Herein for the first time, we present a controlled preparation of large-area graphene/MoS2 heterostructures via a simple heating procedure on Mo-oleate complex coated sodium sulfate under N2 atmosphere. Through a direct in situ catalytic reaction, graphene layer has been uniformly grown on the MoS2 film formed by the reaction of Mo species with S pecies, which is from the carbothermal reduction of sodium sulfate. Due to the excellent graphene ``painting'' on MoS2 atomic layers, the significantly shortened lithium ion diffusion distance and the markedly enhanced electronic conductivity, these multilayered graphene/MoS2 heterostructures exhibit high specific capacity, unprecedented rate performance and outstanding cycling stability, especially at a high current density, when used as an anode material for lithium batteries. This work provides a simple but efficient route for the controlled fabrication of large-area multilayered graphene/metal sulfide heterostructures with promising applications in battery manufacture, electronics or catalysis.

One-dimensional self-confinement promotes polymorph selection in large-area organic semiconductor thin films

KAUST Repository

Giri, Gaurav; Li, Ruipeng; Smilgies, Detlef Matthias; Li, Erqiang; Diao, Ying; Lenn, Kristina M.; Chiu, Melanie; Lin, Debora W.; Allen, Ranulfo A.; Reinspach, Julia A.; Mannsfeld, Stefan C B; Thoroddsen, Sigurdur T; Clancy, Paulette; Bao, Zhenan; Amassian, Aram

2014-01-01

A crystal's structure has significant impact on its resulting biological, physical, optical and electronic properties. In organic electronics, 6,13(bis-triisopropylsilylethynyl)pentacene (TIPS-pentacene), a small-molecule organic semiconductor, adopts metastable polymorphs possessing significantly faster charge transport than the equilibrium crystal when deposited using the solution-shearing method. Here, we use a combination of high-speed polarized optical microscopy, in situ microbeam grazing incidence wide-angle X-ray-scattering and molecular simulations to understand the mechanism behind formation of metastable TIPS-pentacene polymorphs. We observe that thin-film crystallization occurs first at the air-solution interface, and nanoscale vertical spatial confinement of the solution results in formation of metastable polymorphs, a one-dimensional and large-area analogy to crystallization of polymorphs in nanoporous matrices. We demonstrate that metastable polymorphism can be tuned with unprecedented control and produced over large areas by either varying physical confinement conditions or by tuning energetic conditions during crystallization through use of solvent molecules of various sizes. © 2014 Macmillan Publishers Limited.

One-dimensional self-confinement promotes polymorph selection in large-area organic semiconductor thin films.

Science.gov (United States)

Giri, Gaurav; Li, Ruipeng; Smilgies, Detlef-M; Li, Er Qiang; Diao, Ying; Lenn, Kristina M; Chiu, Melanie; Lin, Debora W; Allen, Ranulfo; Reinspach, Julia; Mannsfeld, Stefan C B; Thoroddsen, Sigurdur T; Clancy, Paulette; Bao, Zhenan; Amassian, Aram

2014-04-16

A crystal's structure has significant impact on its resulting biological, physical, optical and electronic properties. In organic electronics, 6,13(bis-triisopropylsilylethynyl)pentacene (TIPS-pentacene), a small-molecule organic semiconductor, adopts metastable polymorphs possessing significantly faster charge transport than the equilibrium crystal when deposited using the solution-shearing method. Here, we use a combination of high-speed polarized optical microscopy, in situ microbeam grazing incidence wide-angle X-ray-scattering and molecular simulations to understand the mechanism behind formation of metastable TIPS-pentacene polymorphs. We observe that thin-film crystallization occurs first at the air-solution interface, and nanoscale vertical spatial confinement of the solution results in formation of metastable polymorphs, a one-dimensional and large-area analogy to crystallization of polymorphs in nanoporous matrices. We demonstrate that metastable polymorphism can be tuned with unprecedented control and produced over large areas by either varying physical confinement conditions or by tuning energetic conditions during crystallization through use of solvent molecules of various sizes.

Doppler US evaluation of the hypertensive portal system

International Nuclear Information System (INIS)

Needleman, L.; Kurtz, A.B.; Bezzi, M.; Rifkin, M.D.; Pasto, M.E.; Pennell, R.G.; Baltarowich, O.H.; Goldberg, B.B.

1986-01-01

In patients with known portal hypertension, pulsed Doppler US was used for qualitative and directional evaluation of flow in the portal venous system and collateral vessels. Most patients had normal hepatopetal flow. Doppler US revealed the following abnormal blood flow patterns: hepatofugal portal flow, bidirectional portal flow, intrahepatic portal shunting, flow in portasystemic collaterals, and hepatic vein obstruction. Doppler US can provide important clinical information in the evaluation of portal hypertension

Evaluation of image quality for various electronic portal imaging devices in radiation therapy

Energy Technology Data Exchange (ETDEWEB)

Son, Soon Yong; Choi, Kwan Woo [Dept. of Radiology, Asan Medical Center, Seoul (Korea, Republic of); Kim, Jung Min [Dept. of College of Health Science, Radiologic Science, Korea University, Seoul (Korea, Republic of); and others

2015-12-15

In megavoltage (MV) radiotherapy, delivering the dose to the target volume is important while protecting the surrounding normal tissue. The purpose of this study was to evaluate the modulation transfer function (MTF), the noise power spectrum (NPS), and the detective quantum efficiency (DQE) using an edge block in megavoltage X-ray imaging (MVI). We used an edge block, which consists of tungsten with dimensions of 19 (thickness) × 10 (length) × 1 (width) cm3 and measured the pre-sampling MTF at 6 MV energy. Various radiation therapy (RT) devices such as TrueBeamTM (Varian), BEAMVIEWPLUS (Siemens), iViewGT (Elekta) and Clinac®iX (Varian) were used. As for MTF results, TrueBeamTM(Varian) flattening filter free(FFF) showed the highest values of 0.46 mm-1and1.40mm-1for MTF 0.5 and 0.1. In NPS, iViewGT (Elekta) showed the lowest noise distribution. In DQE, iViewGT (Elekta) showed the best efficiency at a peak DQE and 1 mm-1DQE of 0.0026 and 0.00014, respectively. This study could be used not only for traditional QA imaging but also for quantitative MTF, NPS, and DQE measurement for development of an electronic portal imaging device (EPID)

Accessibility in e-government portals of the Judiciary

Directory of Open Access Journals (Sweden)

Mariana Pessini Mezzaroba

2016-05-01

Full Text Available This article deals with an analysis of the application of Macedo accessibility guidelines (2010 for the publication of texts on the Web. In this paper, e-government portals were observed, particularly the judiciary, using the Supreme Court site Federal (STF, to verify whether the available material allows people with some kind of visual disability to access it and become aware of its contents. We also used the model of accessibility in Electronic Government eMag, established by the Federal Government, through Decree n. 03 of 07 May 2007.It were also developed the graphical representation of synthesis (RGS addressed the issue. The analysis was performed from the application of e-government accessibility evaluator ASES (Appraiser and accessibility Simulator Sites, combining their results with the textual guidelines already mentioned. After analyzing the results, it shows a table with errors and recommendations to the portal.

Knowledge Portals: Ontologies at Work

OpenAIRE

Staab, Steffen; Maedche, Alexander

2001-01-01

Knowledge portals provide views onto domain-specific information on the World Wide Web, thus helping their users find relevant, domain-specific information. The construction of intelligent access and the contribution of information to knowledge portals, however, remained an ad hoc task, requiring extensive manual editing and maintenance by the knowledge portal providers. To diminish these efforts, we use ontologies as a conceptual backbone for providing, accessing, and structuring information...

On line portal imaging

International Nuclear Information System (INIS)

Munro, Peter

1995-01-01

Purpose/Objective: The purpose of this presentation is to review the physics of imaging with high energy x-ray beams; examine the various imaging devices that have been developed for portal imaging; describe some of the image registration methods that have been developed to determine errors in patient positioning quantitatively; and discuss some of the ways that portal imaging has been incorporated into routine clinical practice. Verification of patient positioning has always been an important aspect of external beam radiation therapy. Checks of patient positioning have generally been done with film, however, film suffers from a number of drawbacks, such as poor image display and delays due to film development. Over the past decade many portal imaging devices have been developed by individual investigators and most accelerator manufacturers now offer 'on-line' portal imaging systems, which are intended to overcome the limitations of portal films. The commercial devices can be classified into three categories: T.V. camera-based systems, liquid ionisation chamber systems, and amorphous silicon systems. Many factors influence the quality of images generated by these portal imaging systems. These include factors which are unavoidable (e.g., low subject contrast), factors which depend upon the individual imaging device forming the image (e.g., dose utilisation, spatial resolution) as well as factors which depend upon the characteristics of the linear accelerator irradiating the imaging system (x-ray source size, image magnification). The fundamental factors which limit image quality and the characteristics of individual imaging systems, such as spatial resolution, temporal response, and quantum utilisation will be discussed. One of the major advantages of on-line portal imaging is that many quantitative techniques have been developed to detect errors in patient positioning. The general approach is to register anatomic structures on a portal image with the same

The SNS/HFIR Web Portal System How Can it Help Me?

International Nuclear Information System (INIS)

Miller, Stephen D.; Geist, Al; Herwig, Kenneth W.; Peterson, Peter F.; Reuter, Michael A.; Ren, Shelly; Bilheux, Jean-Christophe; Campbell, Stuart I.; Kohl, James Arthur; Vazhkudai, Sudharshan S.; Cobb, John W.; Lynch, Vickie E.; Chen, Meili; Trater, James R.

2010-01-01

In a busy world, continuing with the status-quo, to do things the way we are already familiar, often seems to be the most efficient way to conduct our work. We look for the value-add to decide if investing in a new method is worth the effort. How shall we evaluate if we have reached this tipping point for change? For contemporary researchers, understanding the properties of the data is a good starting point. The new generation of neutron scattering instruments being built are higher resolution and produce one or more orders of magnitude larger data than the previous generation of instruments. For instance, we have grown out of being able to perform some important tasks with our laptops the data are too big and the computations would simply take too long. These large datasets can be problematic as facility users now begin to grapple with many of the same issues faced by more established computing communities. These issues include data access, management, and movement, data format standards, distributed computing, and collaboration among others. The Neutron Science Portal has been architected, designed, and implemented to provide users with an easy-to-use interface for managing and processing data, while also keeping an eye on meeting modern cybersecurity requirements imposed on institutions. The cost of entry for users has been lowered by utilizing a web interface providing access to backend portal resources. Users can browse or search for data which they are allowed to see, data reduction applications can be run without having to load the software, sample activation calculations can be performed for SNS and HFIR beamlines, McStas simulations can be run on TeraGrid and ORNL computers, and advanced analysis applications such as those being produced by the DANSE project can be run. Behind the scenes is a live cataloging system which automatically catalogs and archives experiment data via the data management system, and provides proposal team members access to their

Effect of contact area on electron transport through graphene-metal interface.

Science.gov (United States)

Liu, Hongmei; Kondo, Hisashi; Ohno, Takahisa

2013-08-21

We perform first-principles investigations of electron transport in armchair graphene nanoribbons adsorbed on Cu(111) and Ni(111) surfaces with various contact areas. We find that the contact area between metals and graphene has different influences on the conductance. The Cu-graphene system shows an increase in differential conductance for more contact area at a low bias voltage, primarily originating from the shift of transmission peaks relative to the Fermi energy. As the bias increases, there is an irregular change of conductance, including a weak negative differential conductance for more contact area. In contrast, the conductance of the Ni-graphene junction is monotonically enhanced with increasing overlap area. The minority spin which shows a broad transmission is responsible for the conductance increase of Ni-graphene. These behaviors can be attributed to different mechanisms of the interfacial electron transport: Charge transfer between graphene and Cu largely dominates the transmission enhancement of Cu-graphene, whereas hybridization between graphene and Ni states plays a more important role in the transmission enhancement of Ni-graphene. The different behaviors of transmission increase correlate with not only the strength of the graphene-metal interaction but also the location of metal d states.

Pregnancy with Portal Hypertension

Science.gov (United States)

Aggarwal, Neelam; Negi, Neha; Aggarwal, Aakash; Bodh, Vijay; Dhiman, Radha K.

2014-01-01

Even though pregnancy is rare with cirrhosis and advanced liver disease, but it may co-exist in the setting of non-cirrhotic portal hypertension as liver function is preserved but whenever encountered together is a complex clinical dilemma. Pregnancy in a patient with portal hypertension presents a special challenge to the obstetrician as so-called physiological hemodynamic changes associated with pregnancy, needed for meeting demands of the growing fetus, worsen the portal hypertension thereby putting mother at risk of potentially life-threatening complications like variceal hemorrhage. Risks of variceal bleed and hepatic decompensation increase many fold during pregnancy. Optimal management revolves round managing the portal hypertension and its complications. Thus management of such cases requires multi-speciality approach involving obstetricians experienced in dealing with high risk cases, hepatologists, anesthetists and neonatologists. With advancement in medical field, pregnancy is not contra-indicated in these women, as was previously believed. This article focuses on the different aspects of pregnancy with portal hypertension with special emphasis on specific cause wise treatment options to decrease the variceal bleed and hepatic decompensation. Based on extensive review of literature, management from pre-conceptional period to postpartum is outlined in order to have optimal maternal and perinatal outcomes. PMID:25755552

Fast magnetic reconstruction of the portal vein with allogeneic blood vessels in canines.

Science.gov (United States)

Wang, Shan-Pei; Yan, Xiao-Peng; Xue, Fei; Dong, Ding-Hui; Zhang, Xu-Feng; Ma, Feng; Wang, Hao-Hua; Lv, Yi

2015-06-01

The resection and reconstruction of large vessels, including the portal vein, are frequently needed in tumor resection. Warm ischemia before reconstruction might have deleterious effects on the function of some vital organs and therefore, how to reconstruct the vessels quickly after resection is extremely important. The present study was to introduce a new type of magnetic compression anastomosis (MCA) device to establish a quick non-suture anastomosis of the portal vein after resection in canines. The new MCA device consists of a pair of titanium alloy and neodymium-ferrum-boron magnet (Ti-NdFeB) composite rings. The NdFeB magnetic ring as a core of the device was hermetically sealed inside the biomedical titanium alloy case. Twelve canines were divided into two groups: a MCA group in which the end-to-end anastomoses was made with a new device after resection in the portal vein and a traditional manual suture (TMS) group consisted of 6 canines. The anastomosis time, anastomotic patency and quality were investigated at week 24 postoperatively. The portal vein was reconstructed successfully in all of the animals and they all survived. The duration of portal vein anastomosis was significantly shorter in the MCA group than in the TMS group (8.16+/-1.25 vs 36.24+/-2.17 min, PNdFeB composite MCA device was applicable in reconstruction of large vessels after resection. This device was easy to use and the anastomosis was functionally better than the traditional sutured anastomosis.

Blood in the gastric lumen increases splanchnic blood flow and portal pressure in portal-hypertensive rats.

Science.gov (United States)

Chen, L; Groszmann, R J

1996-10-01

In portal-hypertensive humans, portal blood flow and pressure increase after a meal. These hemodynamic changes may increase variceal rupture risk. The aim of this study was to determine whether blood in the stomach lumen increases splanchnic flow and portal pressure (PP) in portal-hypertensive rats. superior mesenteric artery flow and PP were measured in conscious, unrestrained, fasted partial portal vein-ligated rats with chronically implanted Doppler flow probes or portal vein catheters before and after gavage with heparinized, warmed blood from donor rats, air, standard meal, or empty tube. Percentage of changes in flow and pressure from baseline were significantly greater after gavage with blood (an increase of 22.6% +/- 3.5% and an increase of 16.4% +/- 3.1%, respectively) than empty tube (an increase of 3.4% +/- 0.6% and a decrease of 5.4% +/- 3.5%, respectively) (P empty tube (P calories probably contributes to these hemodynamic changes. In patients with variceal hemorrhage, blood in the stomach may increase the risk of persistent variceal bleeding or rebleeding.

Antibody Portal | Office of Cancer Clinical Proteomics Research

Science.gov (United States)

Central to reproducibility in biomedical research is being able to use well-characterized and defined reagents. The CPTAC Antibody Portal serves as a National Cancer Institute (NCI) community resource that provides access to a large number of standardized renewable affinity reagents (to cancer-associated targets) and accompanying characterization data.

Portal vein stenting for delayed jejunal varix bleeding associated with portal venous occlusion after hepatoiliary and pancreatic surgery

Energy Technology Data Exchange (ETDEWEB)

Hyun, Dong Ho; Park, Kwang Bo; Cho, Sung Ki; Park, Hong Suk; Shin, Sung Wook; Choo, Sung Wook; Do, Young Soo; Choo, In Wook; Choi, Dong Wook [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

2017-09-15

The study aimed to describe portal stenting for postoperative portal occlusion with delayed (≥ 3 months) variceal bleeding in the afferent jejunal loop. Eleven consecutive patients (age range, 2–79 years; eight men and three women) who underwent portal stenting between April 2009 and December 2015 were included in the study. Preoperative medical history and the postoperative clinical course were reviewed. Characteristics of portal occlusion and details of procedures were also investigated. Technical success, treatment efficacy (defined as disappearance of jejunal varix on follow-up CT), and clinical success were analyzed. Primary stent patency rate was plotted using the Kaplan-Meier method. All patients underwent hepatobiliary-pancreatic cancer surgery except two children with liver transplantation for biliary atresia. Portal occlusion was caused by benign postoperative change (n = 6) and local tumor recurrence (n = 5). Variceal bleeding occurred at 27 months (4 to 72 months) and portal stenting was performed at 37 months (4 to 121 months), on average, postoperatively. Technical success, treatment efficacy, and clinical success rates were 90.9, 100, and 81.8%, respectively. The primary patency rate of portal stent was 88.9% during the mean follow-up period of 9 months. Neither procedure-related complication nor mortality occurred. Interventional portal stenting is an effective treatment for delayed jejunal variceal bleeding due to portal occlusion after hepatobiliary-pancreatic surgery.

Portal vein stenting for delayed jejunal varix bleeding associated with portal venous occlusion after hepatoiliary and pancreatic surgery

International Nuclear Information System (INIS)

Hyun, Dong Ho; Park, Kwang Bo; Cho, Sung Ki; Park, Hong Suk; Shin, Sung Wook; Choo, Sung Wook; Do, Young Soo; Choo, In Wook; Choi, Dong Wook

2017-01-01

The study aimed to describe portal stenting for postoperative portal occlusion with delayed (≥ 3 months) variceal bleeding in the afferent jejunal loop. Eleven consecutive patients (age range, 2–79 years; eight men and three women) who underwent portal stenting between April 2009 and December 2015 were included in the study. Preoperative medical history and the postoperative clinical course were reviewed. Characteristics of portal occlusion and details of procedures were also investigated. Technical success, treatment efficacy (defined as disappearance of jejunal varix on follow-up CT), and clinical success were analyzed. Primary stent patency rate was plotted using the Kaplan-Meier method. All patients underwent hepatobiliary-pancreatic cancer surgery except two children with liver transplantation for biliary atresia. Portal occlusion was caused by benign postoperative change (n = 6) and local tumor recurrence (n = 5). Variceal bleeding occurred at 27 months (4 to 72 months) and portal stenting was performed at 37 months (4 to 121 months), on average, postoperatively. Technical success, treatment efficacy, and clinical success rates were 90.9, 100, and 81.8%, respectively. The primary patency rate of portal stent was 88.9% during the mean follow-up period of 9 months. Neither procedure-related complication nor mortality occurred. Interventional portal stenting is an effective treatment for delayed jejunal variceal bleeding due to portal occlusion after hepatobiliary-pancreatic surgery

Portal verification using the KODAK ACR 2000 RT storage phosphor plate system and EC registered films. A semiquantitative comparison

International Nuclear Information System (INIS)

Geyer, P.; Blank, H.; Alheit, H.

2006-01-01

Background and Purpose: the suitability of the storage phosphor plate system ACR 2000 RT (Eastman Kodak Corp., Rochester, MN, USA), that is destined for portal verification as well as for portal simulation imaging in radiotherapy, had to be proven by the comparison with a highly sensitive verification film. Material and Methods: the comparison included portal verification images of different regions (head and neck, thorax, abdomen, and pelvis) irradiated with 6- and 15-MV photons and electrons. Each portal verification image was done at the storage screen and the EC registered film as well, using the EC-L registered cassettes (both: Eastman Kodak Corp., Rochester, MN, USA) for both systems. The soft-tissue and bony contrast and the brightness were evaluated and compared in a ranking of the two compared images. Different phantoms were irradiated to investigate the high- and low-contrast resolution. To account for quality assurance application, the short-time exposure of the unpacked and irradiated storage screen by green and red room lasers was also investigated. Results: in general, the quality of the processed ACR images was slightly higher than that of the films, mostly due to cases of an insufficient exposure to the film. The storage screen was able to verify electron portals even for low electron energies with only minor photon contamination. The laser lines were sharply and clearly visible on the ACR images. Conclusion: the ACR system may replace the film without any noticeable decrease in image quality thereby reducing processing time and saving the costs of films and avoiding incorrect exposures. (orig.)

TMEM16A regulates portal vein smooth muscle cell proliferation in portal hypertension.

Science.gov (United States)

Zeng, Xi; Huang, Ping; Chen, Mingkai; Liu, Shiqian; Wu, Nannan; Wang, Fang; Zhang, Jing

2018-01-01

The aim of the present study was to elucidate the effect of transmembrane protein 16A (TMEM16A) on portal vein smooth muscle cell (PVSMC) proliferation associated with portal vein remodeling in portal hypertension (PHT). Sprague-Dawley rats were subjected to bile duct ligation to establish a rat model of liver cirrhosis and PHT. Sham-operated animals served as controls. At 8 weeks after bile duct ligation, the extent of liver fibrosis and the portal vein wall thickness were assessed using hematoxylin-eosin staining. The protein expression levels of TMEM16A, extracellular signal-regulated kinase 1 and 2 (ERK1/2) and phosphorylated ERK1/2 (p-ERK1/2) in the portal vein were detected by immunohistochemistry and western blotting. In vitro , the lentivirus vectors were constructed and transfected into PVSMCs to upregulate the expression of TMEM16A. Isolated rat primary PVSMCs were treated with a small molecule inhibitor of TMEM16A, T16A-inhA01. Cell cycle was detected by flow cytometry. The activity of TMEM16A in the portal vein isolated from bile duct ligated rats was decreased, while the expression level of p-ERK1/2 was increased. However, in vitro , upregulation of TMEM16A promoted the proliferation PVSMCs, while inhibition of TMEM16A channels inhibited the proliferation of PVSMCs. The results indicated that TMEM16A contributes to PVSMCs proliferation in vitro , but in vivo , it may be a negative regulator of cell proliferation influenced by numerous factors.

Cavernous transformation of the portal vein

International Nuclear Information System (INIS)

Lehotska, V.; Dostalova, K.; Durkovsky, A.; Samal, V.

1995-01-01

In this contribution, the authors give an account of a rare case of a cavernous transformation of the portal vein that may have originated secondarily in a proliferative hematogenous disease with a polyglobulia and thrombosis in the periferal blood count as well as development of portal hypertension of a prehepatal type. The state of hyper-coagulation in a myeloproliferative disease may have lead to a chronic thrombosis of the portal vein with a subsequent malformation of the portal vein in terms of a cavernous transformation of the portal vein. The case is an interesting one because of the discrepancy between the gravity of the thrombotic complication and slightness of the symptoms in the clinical picture. The authors point out the importance of ultrasonography and computed tomography examination following the intravenous application of a water solution of a contrast medium in a morphologic diagnosing of a rare complication of a chronic thrombotic clot of the portal vein - the cavernous transformation. (authors)

Estimation of four-dimensional dose distribution using electronic portal imaging device in radiation therapy

International Nuclear Information System (INIS)

Mizoguchi, Asumi; Arimura, Hidetaka; Shioyama, Yoshiyuki

2013-01-01

We are developing a method to evaluate four-dimensional radiation dose distribution in a patient body based upon the animated image of EPID (electronic portal imaging device) which is an image of beam-direction at the irradiation. In the first place, we have obtained the image of the dose which is emitted from patient body at therapy planning using therapy planning CT image and dose evaluation algorism. In the second place, we have estimated the emission dose image at the irradiation using EPID animated image which is obtained at the irradiation. In the third place, we have got an affine transformation matrix including respiratory movement in the body by performing linear registration on the emission dose image at therapy planning to get the one at the irradiation. In the fourth place, we have applied the affine transformation matrix on the therapy planning CT image and estimated the CT image 'at irradiation'. Finally we have evaluated four-dimensional dose distribution by calculating dose distribution in the CT image 'at irradiation' which has been estimated for each frame of the EPID animated-image. This scheme may be useful for evaluating therapy results and risk management. (author)

Programmable and functional electrothermal bimorph actuators based on large-area anisotropic carbon nanotube paper

Science.gov (United States)

Li, Qingwei; Liu, Changhong; Fan, Shoushan

2018-04-01

Electro-active polymer (EAP) actuators, such as electronic, ionic and electrothermal (ET) actuators, have become an important branch of next-generation soft actuators in bionic robotics. However, most reported EAP actuators could realize only simple movements, being restricted by the small area of flexible electrodes and simple designs. We prepared large-area flexible electrodes of high anisotropy, made of oriented carbon nanotube (CNT) paper, and carried out artful graphic designs and processing on the electrodes to make functional ET bimorph actuators which can realize large bending deformations (over 220°, curvature > 1.5 cm-1) and bionic movements driven by electricity. The anisotropy of CNT paper benefits electrode designs and multiform actuations for complex actuators. Based on the large-area CNT paper, more interesting and functional actuators can be designed and prepared which will have practical applications in the fields of artificial muscles, complicated actuations, and soft and bionic robotics.

Assessment of a customised immobilisation system for head and neck IMRT using electronic portal imaging

International Nuclear Information System (INIS)

Humphreys, Mandy; Guerrero Urbano, M.Teressa; Mubata, Cefas; Miles, Elizabeth; Harrington, Kevin J.; Bidmead, Margaret; Nutting, Christopher M.

2005-01-01

Purpose: To evaluate set-up reproducibility of a cabulite shell and determine CTV-PTV margins for head and neck intensity-modulated-radiotherapy. Materials and methods: Twenty patients were entered into the study. A total of 354 anterior and lateral isocentric electronic portal images (EPIs) were compared to simulator reference images. Results: About 94% of all translational displacements were ≤3 mm, and 99% ≤5 mm. The overall systematic error was 0.9 mm (±1.0SD) in the Right-Left, 0.7 mm (±0.9SD) in the Superior-Inferior and -0.02 mm (±1.1SD) in the Anterior-Posterior directions. The corresponding SDs of the random errors were ±0.4, ±0.6 and ±0.7 mm. The estimated margins required from CTV-PTV were calculated according to the Van Herk formula was 2.9, 2.6 and 3.3 mm, respectively. Conclusions: This head and neck immobilisation system is of sufficient accuracy for its use with IMRT treatments and a 3 mm CTV-PTV margin has been adopted

Study of radiation portal monitor and its application to metal recycling industry

International Nuclear Information System (INIS)

Pujol, L.; Lara-Calleja, S.; Suarez-Navarro, M. J.; Gonzalez-Gonzalez, J. A.

2009-01-01

The industry of the iron and the steel in one of the most important sectors in Spain for its economic development. the recycling of metallic materials as well as the import of metallic scrap is very significant. Several reports on accidental dispersion or smelting of radioactive sources in metal recycling industries confirm the possibility that radioactive material might be mixed with scrap. In consequence, this type of accident shows the necessity of a rigorous and specific radiation control of the sector. The control of these materials with radioactive content can be carried out with radiation portal monitors installed at the entrance of these industries. The detection of radioactive materials presents special features as the continuous background acquisition or the minimisation of the relatively large number of innocent/nuisance detections. In the present work, we study a radiation portal monitor, the FHT-1388-T Thermo-Eberline. This is one of the usual radiation portal systems installed at the entrance of the metal recycling industry. Se study the characteristics and parameters of this portal monitor to optimise its use. furthermore, we propose some rapid tests for radiation portal systems in metal recycling industry. (Author) 16 refs

Morphological and biomechanical remodeling of the hepatic portal vein in a swine model of portal hypertension.

Science.gov (United States)

He, Xi-Ju; Huang, Tie-Zhu; Wang, Pei-Jun; Peng, Xing-Chun; Li, Wen-Chun; Wang, Jun; Tang, Jie; Feng, Na; Yu, Ming-Hua

2012-02-01

To obtain the morphological and biomechanical remodeling of portal veins in swine with portal hypertension (PHT), so as to provide some mechanical references and theoretical basis for clinical practice about PHT. Twenty white pigs were used in this study, 14 of them were subjected to both carbon tetrachloride- and pentobarbital-containing diet to induce experimental liver cirrhosis and PHT, and the remaining animals served as the normal controls. The morphological remodeling of portal veins was observed. Endothelial nitric oxide synthase expression profile in the vessel wall was assessed at both mRNA and protein level. The biomechanical changes of the hepatic portal veins were evaluated through assessing the following indicators: the incremental elastic modulus, pressure-strain elastic modulus, volume elastic modulus, and the incremental compliance. The swine PHT model was successfully established. The percentages for the microstructural components and the histological data significantly changed in the experimental group. Endothelial nitric oxide synthase expression was significantly downregulated in the portal veins of the experimental group. Three incremental elastic moduli (the incremental elastic modulus, pressure-strain elastic modulus, and volume elastic modulus) of the portal veins from PHT animals were significantly larger than those of the controls (P portal vein decreased. Our study suggests that the morphological and biomechanical properties of swine hepatic portal veins change significantly during the PHT process, which may play a critical role in the development of PHT and serve as potential therapeutic targets during clinical practice. Copyright © 2012 Annals of Vascular Surgery Inc. Published by Elsevier Inc. All rights reserved.

Prediction of DVH parameter changes due to setup errors for breast cancer treatment based on 2D portal dosimetry

International Nuclear Information System (INIS)

Nijsten, S. M. J. J. G.; Elmpt, W. J. C. van; Mijnheer, B. J.; Minken, A. W. H.; Persoon, L. C. G. G.; Lambin, P.; Dekker, A. L. A. J.

2009-01-01

Electronic portal imaging devices (EPIDs) are increasingly used for portal dosimetry applications. In our department, EPIDs are clinically used for two-dimensional (2D) transit dosimetry. Predicted and measured portal dose images are compared to detect dose delivery errors caused for instance by setup errors or organ motion. The aim of this work is to develop a model to predict dose-volume histogram (DVH) changes due to setup errors during breast cancer treatment using 2D transit dosimetry. First, correlations between DVH parameter changes and 2D gamma parameters are investigated for different simulated setup errors, which are described by a binomial logistic regression model. The model calculates the probability that a DVH parameter changes more than a specific tolerance level and uses several gamma evaluation parameters for the planning target volume (PTV) projection in the EPID plane as input. Second, the predictive model is applied to clinically measured portal images. Predicted DVH parameter changes are compared to calculated DVH parameter changes using the measured setup error resulting from a dosimetric registration procedure. Statistical accuracy is investigated by using receiver operating characteristic (ROC) curves and values for the area under the curve (AUC), sensitivity, specificity, positive and negative predictive values. Changes in the mean PTV dose larger than 5%, and changes in V 90 and V 95 larger than 10% are accurately predicted based on a set of 2D gamma parameters. Most pronounced changes in the three DVH parameters are found for setup errors in the lateral-medial direction. AUC, sensitivity, specificity, and negative predictive values were between 85% and 100% while the positive predictive values were lower but still higher than 54%. Clinical predictive value is decreased due to the occurrence of patient rotations or breast deformations during treatment, but the overall reliability of the predictive model remains high. Based on our

Portal hyperflow in patients with hepatosplenic mansonic schistosomiasis Hiperfluxo portal na forma hepatosplênica da esquistossomose mansônica

Directory of Open Access Journals (Sweden)

Roberto de Cleva

2004-02-01

Full Text Available PURPOSE: The purpose of this study was to assess portal hemodynamics in patients with portal hypertension due to hepatosplenic schistosomiasis as well as to assess the contribution of splanchnic hyperflow to the pathophysiology of the portal hypertension. METHODS: Sixteen patients with schistosomal portal hypertension and previous history of upper digestive bleeding due to esophageal varices rupture underwent elective esophagogastric devascularization and splenectomy and were prospectively studied. All patients underwent intraoperative invasive hemodynamic portal monitoring with a 4F-thermodilution catheter. The intraoperative portal hemodynamic assessment was conducted after laparotomy (initial and after esophagogastric devascularization (final. RESULTS: The initial portal pressure was elevated (mean 28.5 ± 4.5 mm Hg, and a significant drop of 25% was observed at the end of the surgery (21.9 ± 4.9 mm Hg. The initial portal flow was elevated (mean 1766.9 ± 686.6 mL/min. A significant fall (42% occurred at the end of the surgical procedure (1025.62 ± 338.7 mL/min. Fourteen patients (87.5% presented a portal flow of more than 1200 mL/min, and in 5 cases, values greater than 2000 mL/min were observed. CONCLUSIONS: Esophagogastric devascularization and splenectomy promote a significant reduction of the elevated portal pressure and flow in schistosomal portal hypertension. These data favor the hypothesis of portal hyperflow in the physiopathology of portal hypertension of schistosomiasis.OBJETIVOS: o objetivo do presente estudo é estudar a hemodinâmica portal em pacientes com hipertensão portal secundária a forma hepatoesplênica da esquistossomose e avaliar a contribuição do hiperfluxo esplênico na sua fisiopatologia CASUÍSTICA E MÉTODOS: Foram estudados prospectivamente 16 pacientes portadores de hipertensão portal secundária à forma hepatoesplênica da esquistossomose mansônica com indicação de tratamento cirúrgico. Todos foram

Intelligent interaction based on holographic personalized portal

Directory of Open Access Journals (Sweden)

Yadong Huang

2017-06-01

Full Text Available Purpose – The purpose of this paper is to study the architecture of holographic personalized portal, user modeling, commodity modeling and intelligent interaction. Design/methodology/approach – In this paper, the authors propose crowd-science industrial ecological system based on holographic personalized portal and its interaction. The holographic personality portal is based on holographic enterprises, commodities and consumers, and the personalized portal consists of accurate ontology, reliable supply, intelligent demand and smart cyberspace. Findings – The personalized portal can realize the information acquisition, characteristic analysis and holographic presentation. Then, the intelligent interaction, e.g. demand decomposition, personalized search, personalized presentation and demand prediction, will be implemented within the personalized portal. Originality/value – The authors believe that their work on intelligent interaction based on holographic personalized portal, which has been first proposed in this paper, is innovation focusing on the interaction between intelligence and convenience.

A Large Hadron Electron Collider at CERN, Physics, Machine, Detector

CERN Document Server

Adolphson, C

2011-01-01

The physics programme and the design are described of a new electron-hadron collider, the LHeC, in which electrons of $60$ to possibly $140$\\,GeV collide with LHC protons of $7000$\\,GeV. With an $ep$ design luminosity of about $10^{33}$\\,cm$^{-2}$s$^{-1}$, the Large Hadron Electron Collider exceeds the integrated luminosity collected at HERA by two orders of magnitude and the kinematic range by a factor of twenty in the four-momentum squared, $Q^2$, and in the inverse Bjorken $x$. The physics programme is devoted to an exploration of the energy frontier, complementing the LHC and its discovery potential for physics beyond the Standard Model with high precision deep inelastic scattering (DIS) measurements. These are projected to solve a variety of fundamental questions in strong and electroweak interactions. The LHeC thus becomes the world's cleanest high resolution microscope, designed to continue the path of deep inelastic lepton-hadron scattering into unknown areas of physics and kinematics. The physics ...

Portal venous hemodynamics in cystic fibrosis: A criterion of hepatic involvement

International Nuclear Information System (INIS)

Vergesslich, K.A.; Sommer, G.; Mostbeck, G.; Ponhold, W.; Gotz, M.

1986-01-01

In 24 patients with cystic fibrosis (CF), mean age 11.6 years, the velocity, flow volume, and cross-sectional area of the portal vein were determined by duplex-US, and findings were compared with findings in 30 age-matched controls. Size and echogenicity of liver and spleen were assessed by real-time US. There was a significant difference between CF and normal mean values, including, in CF, a decrease in velocity (P <.003), an increase in cross-sectional area (P <.001), and an increase in flow volume (P <.05). Changes in portal venous hemodynamics correlated with increased liver echogenicity and spleen size, suggestive of chronic parenchymal liver disease. Duplex US is a valuable diagnostic tool in the assessment of hepatic involvement in CF

Thickness determination of large-area films of yttria-stabilized zirconia produced by pulsed laser deposition

Energy Technology Data Exchange (ETDEWEB)

Pryds, N. [Materials Research Department, Riso National Laboratory, DK-4000 Roskilde (Denmark)]. E-mail: nini.pryds@risoe.dk; Toftmann, B. [Department of Optics and Plasma Research, Riso National Laboratory, DK-4000 Roskilde (Denmark); Bilde-Sorensen, J.B. [Materials Research Department, Riso National Laboratory, DK-4000 Roskilde (Denmark); Schou, J. [Department of Optics and Plasma Research, Riso National Laboratory, DK-4000 Roskilde (Denmark); Linderoth, S. [Materials Research Department, Riso National Laboratory, DK-4000 Roskilde (Denmark)

2006-04-30

Films of yttria-stabilized zirconia (YSZ) on a polished silicon substrate of diameter up to 125 mm have been produced in a large-area pulsed laser deposition (PLD) setup under typical PLD conditions. The film thickness over the full film area has been determined by energy-dispersive X-ray spectrometry in a scanning electron microscope (SEM) with use of a method similar to one described by Bishop and Poole. The attenuation of the electron-induced X-rays from the Si wafer by the film was monitored at a number of points along a diameter and the thickness was determined by Monte Carlo simulations of the attenuation for various values of film thickness with the program CASINO. These results have been compared with direct measurements in the SEM of the film thickness on a cross-section on one of the wafers. The results of these measurements demonstrate the ability of this technique to accurately determine the thickness of a large film, i.e. up to diameters of 125 mm, in a relatively short time, without destroying the substrate, without the need of a standard sample and without the need of a flat substrate. We have also demonstrated that by controlling the deposition parameters large-area YSZ films with uniform thickness can be produced.

Thickness determination of large-area films of yttria-stabilized zirconia produced by pulsed laser deposition

International Nuclear Information System (INIS)

Pryds, N.; Toftmann, B.; Bilde-Sorensen, J.B.; Schou, J.; Linderoth, S.

2006-01-01

Films of yttria-stabilized zirconia (YSZ) on a polished silicon substrate of diameter up to 125 mm have been produced in a large-area pulsed laser deposition (PLD) setup under typical PLD conditions. The film thickness over the full film area has been determined by energy-dispersive X-ray spectrometry in a scanning electron microscope (SEM) with use of a method similar to one described by Bishop and Poole. The attenuation of the electron-induced X-rays from the Si wafer by the film was monitored at a number of points along a diameter and the thickness was determined by Monte Carlo simulations of the attenuation for various values of film thickness with the program CASINO. These results have been compared with direct measurements in the SEM of the film thickness on a cross-section on one of the wafers. The results of these measurements demonstrate the ability of this technique to accurately determine the thickness of a large film, i.e. up to diameters of 125 mm, in a relatively short time, without destroying the substrate, without the need of a standard sample and without the need of a flat substrate. We have also demonstrated that by controlling the deposition parameters large-area YSZ films with uniform thickness can be produced

Nursing portal; a nursing informatics solution for iran, lessons learned from a comparative study.

Science.gov (United States)

Safdari, Reza; Masoori, Niloufar; Torabi, Mashaallah; Cheraghi, Mohammad A; Farzananejad, Ahmadreza; Azadmanjir, Zahra

2012-01-01

The nursing portal is an informatics solution in which services and capabilities supports the nursing staff in their practices and professional development with respect to the existing challenges for use of Internet by nurses at work. It can be considered as a creditable gateway for quick access to research-based evidence provided by reliable resources. Also it provide interactive virtual environment for knowledge exchange with experts or colleagues in different geographical area. Through a comparative study on specialized nursing portals in Iran and other three countries, the aim of this paper is defining desired content and structural specifications of nursing portals which support the practice of nurses in the workplace. Based on results of the present study, a set of recommendations provide for development of a comprehensive nursing portal in Iran.

Large catchment area recharges Titan's Ontario Lacus

Science.gov (United States)

Dhingra, Rajani D.; Barnes, Jason W.; Yanites, Brian J.; Kirk, Randolph L.

2018-01-01

We seek to address the question of what processes are at work to fill Ontario Lacus while other, deeper south polar basins remain empty. Our hydrological analysis indicates that Ontario Lacus has a catchment area spanning 5.5% of Titan's surface and a large catchment area to lake surface area ratio. This large catchment area translates into large volumes of liquid making their way to Ontario Lacus after rainfall. The areal extent of the catchment extends to at least southern mid-latitudes (40°S). Mass conservation calculations indicate that runoff alone might completely fill Ontario Lacus within less than half a Titan year (1 Titan year = 29.5 Earth years) assuming no infiltration. Cassini Visual and Infrared Mapping Spectrometer (VIMS) observations of clouds over the southern mid and high-latitudes are consistent with precipitation feeding Ontario's large catchment area. This far-flung rain may be keeping Ontario Lacus filled, making it a liquid hydrocarbon oasis in the relatively dry south polar region.

Radiation portal evaluation parameters

International Nuclear Information System (INIS)

York, R.L.

1998-01-01

The detection of the unauthorized movement of radioactive materials is one of the most effective nonproliferation measures. Automatic special nuclear material (SNM) portal monitors are designed to detect this unauthorized movement and are an important part of the safeguard systems at US nuclear facilities. SNM portals differ from contamination monitors because they are designed to have high sensitivity for the low energy gamma-rays associated with highly enriched uranium (HEU) and plutonium. These instruments are now being installed at international borders to prevent the spread of radioactive contamination an SNM. In this paper the parameters important to evaluating radiation portal monitors are discussed. (author)

CMOS compatible route for GaAs based large scale flexible and transparent electronics

KAUST Repository

Nour, Maha A.; Ghoneim, Mohamed T.; Droopad, Ravi; Hussain, Muhammad Mustafa

2014-01-01

Flexible electronics using gallium arsenide (GaAs) for nano-electronics with high electron mobility and optoelectronics with direct band gap are attractive for many applications. Here we describe a state-of-the-art CMOS compatible batch fabrication process of transforming traditional electronic circuitry into large-area flexible, semitransparent platform. We show a simple release process for peeling off 200 nm of GaAs from 200 nm GaAs/300 nm AlAs stack on GaAs substrate using diluted hydrofluoric acid (HF). This process enables releasing a single top layer compared to peeling off all layers with small sizes at the same time. This is done utilizing a network of release holes which contributes to the better transparency (45 % at 724 nm wavelength) observed.

CMOS compatible route for GaAs based large scale flexible and transparent electronics

KAUST Repository

Nour, Maha A.

2014-08-01

Flexible electronics using gallium arsenide (GaAs) for nano-electronics with high electron mobility and optoelectronics with direct band gap are attractive for many applications. Here we describe a state-of-the-art CMOS compatible batch fabrication process of transforming traditional electronic circuitry into large-area flexible, semitransparent platform. We show a simple release process for peeling off 200 nm of GaAs from 200 nm GaAs/300 nm AlAs stack on GaAs substrate using diluted hydrofluoric acid (HF). This process enables releasing a single top layer compared to peeling off all layers with small sizes at the same time. This is done utilizing a network of release holes which contributes to the better transparency (45 % at 724 nm wavelength) observed.

A simple quality assurance test tool for the visual verification of light and radiation field congruent using electronic portal images device and computed radiography

International Nuclear Information System (INIS)

Njeh, Christopher F; Caroprese, Blas; Desai, Pushkar

2012-01-01

The radiation field on most megavoltage radiation therapy units are shown by a light field projected through the collimator by a light source mounted inside the collimator. The light field is traditionally used for patient alignment. Hence it is imperative that the light field is congruent with the radiation field. A simple quality assurance tool has been designed for rapid and simple test of the light field and radiation field using electronic portal images device (EPID) or computed radiography (CR). We tested this QA tool using Varian PortalVision and Elekta iViewGT EPID systems and Kodak CR system. Both the single and double exposure techniques were evaluated, with double exposure technique providing a better visualization of the light-radiation field markers. The light and radiation congruency could be detected within 1 mm. This will satisfy the American Association of Physicists in Medicine task group report number 142 recommendation of 2 mm tolerance. The QA tool can be used with either an EPID or CR to provide a simple and rapid method to verify light and radiation field congruence

Design and implementation of a web-based patient portal linked to an electronic health record designed to improve medication safety: the Patient Gateway medications module

Directory of Open Access Journals (Sweden)

Jeffrey Schnipper

2008-07-01

Full Text Available In this article we describe the background, design, and preliminary results of a medications module within Patient Gateway (PG, a patient portal linked to an electronic health record (EHR. The medications module is designed to improve the accuracy of medication lists within the EHR, reduce adverse drug events and improve patient_provider communication regarding medications and allergies in several primary care practices within a large integrated healthcare delivery network. This module allows patients to view and modify the list of medications and allergies from the EHR, report nonadherence, side effects and other medication-related problems and easily communicate this information to providers, who can verify the information and update the EHR as needed. Usage and satisfaction data indicate that patients found the module easy to use, felt that it led to their providers having more accurate information about them and enabled them to feel more prepared for their forthcoming visits. Further analyses will determine the effects of this module on important medication-related outcomes and identify further enhancements needed to improve on this approach.

Frequency of gastric varices in patients with portal hypertension based on endoscopic findings

International Nuclear Information System (INIS)

Mir, A.W.; Chaudry, A.A.; Mir, S.; Ahmed, N.; Khan, A.A.; Shahzadi, M.

2017-01-01

To find out the frequency of gastric varices in patients with portal hypertension based on endoscopic findings. Study Design: Descriptive Study. Place and Duration of Study: Department of Gastroenterology, Military Hospital, Rawalpindi from Jan to Jun 2011. Material and Methods: All patients fulfilling the inclusion criteria were selected through consecutive sampling. The patients presenting with hematemesis, melena or ascites with portal hypertension on ultrasound abdomen were admitted in the hospital. The patients were first stabilized hemodynamically and then kept empty stomach for at least four hours before endoscopy. The patients were sedated with intravenous midazolam and endoscopic findings obtained were entered on the patient proforma. Results: The overall frequency of gastric varices was 11 percent, whereas 89 percent had no gastric varices. Conclusion: A large number of patients with portal hypertension have gastric varices. It is recommended that endoscopy be carried out in all patients with identified portal hypertension. (author)

Editor's welcome, PORTAL, Vol. 1, No. 2, July 2004

Directory of Open Access Journals (Sweden)

Paul Allatson

2005-03-01

Full Text Available Since the highly successful inauguration of PORTAL in January 2004, we have received many kind expressions of support from international studies practitioners in a range of fields, and from such places as Canada, Italy, Mexico, Nigeria, New Zealand, Spain, Trinidad, the U.K., and the U.S.A. Particularly gratifying have been the endorsements of the journal and its publishing aims by people involved in their own electronic publishing enterprises. For their generous responses to PORTAL, the Editorial Committee would like to express its collective appreciation to the following people: Professor Jean-Marie Volet, of the University of Western Australia, and the guiding editor of the ground-breaking e-journal Mots Pluriels (www.arts.uwa.edu.au/MotsPluriels; and Francis Leo Collins, member of the Editorial Committee for the Graduate Journal of Asia Pacific Studies (GJAPS, based in Auckland, New Zealand. PORTAL's readers may be interested in the current call for papers from GJAPS (www.arts.auckland.ac.nz/gjaps, for a special issue on "Imagining the Asia-Pacific" (deadline October 31, 2004. This issue of PORTAL contains essays that cover wide terrain: the Chilean diasporic community in Australia; the world of German intellectuals; contemporary Mexican socio-political movements; rural-urban migration in China; and transnational advocacy networks and election monitoring in the Philippines, Chile, Nicaragua and Mexico. In the cultural section of this issue, we are delighted to present a short story from the noted German Studies scholar Anthony Stephens, and the first half of a beautiful, deeply poetic and haunting novel entitled Son, from the London-based writer and art-critic Jennifer Higgie. The novel’s second and final part will appear in PORTAL vol. 2, no. 1, in January 2005. On a different note, we would like to express our support for the inaugural Ubud Writers and Readers Festival, to be held in Ubud, Bali, from October 11 to 17, 2004. The Festival

LEP - Large Electron Positron Exhibition LEPFest 2000

CERN Multimedia

2000-01-01

The Large Electron-Positron Collider (LEP) is 27 km long. Its four detectors (ALEPH, DELPHI, L3, OPAL) measure precisely what happens in the collisions of electrons and positrons. These conditions only exist-ed in the Universe when it was about 10 -10 sec old.

Novel Rat Model of Repetitive Portal Venous Embolization Mimicking Human Non-Cirrhotic Idiopathic Portal Hypertension

DEFF Research Database (Denmark)

Klein, Sabine; Hinüber, Christian; Hittatiya, Kanishka

2016-01-01

BACKGROUND: Non-cirrhotic idiopathic portal hypertension (NCIPH) is characterized by splenomegaly, anemia and portal hypertension, while liver function is preserved. However, no animal models have been established yet. This study assessed a rat model of NCIPH and characterized the hemodynamics......, and compared it to human NCIPH. METHODS: Portal pressure (PP) was measured invasively and coloured microspheres were injected in the ileocecal vein in rats. This procedure was performed weekly for 3 weeks (weekly embolization). Rats without and with single embolization served as controls. After four weeks (one...... in the weekly embolization group. Fibrotic markers αSMA and Desmin were upregulated in weekly embolized rats. DISCUSSION: This study establishes a model using repetitive embolization via portal veins, comparable with human NCIPH and may serve to test new therapies....

Idiopathic Noncirrhotic Portal Hypertension: An Appraisal

Science.gov (United States)

Lee, Hwajeong; Rehman, Aseeb Ur; Fiel, M. Isabel

2016-01-01

Idiopathic noncirrhotic portal hypertension is a poorly defined clinical condition of unknown etiology. Patients present with signs and symptoms of portal hypertension without evidence of cirrhosis. The disease course appears to be indolent and benign with an overall better outcome than cirrhosis, as long as the complications of portal hypertension are properly managed. This condition has been recognized in different parts of the world in diverse ethnic groups with variable risk factors, resulting in numerous terminologies and lack of standardized diagnostic criteria. Therefore, although the diagnosis of idiopathic noncirrhotic portal hypertension requires clinical exclusion of other conditions that can cause portal hypertension and histopathologic confirmation, this entity is under-recognized clinically as well as pathologically. Recent studies have demonstrated that variable histopathologic entities with different terms likely represent a histologic spectrum of a single entity of which obliterative portal venopathy might be an underlying pathogenesis. This perception calls for standardization of the nomenclature and formulation of widely accepted diagnostic criteria, which will facilitate easier recognition of this disorder and will highlight awareness of this entity. PMID:26563701

Validation of intensity modulated radiation therapy patient plans with portal images

International Nuclear Information System (INIS)

Delpon, G.; Warren, S.; Mahe, D.; Gaudaire, S.; Lisbona, A.

2007-01-01

The goal of this study was to show the feasibility of step and shoot intensity-modulated radiation therapy pre-treatment quality control for patients using the electronic portal imaging device (iViewGT) fitted on a Sli+ linac (Elekta Oncology Systems, Crawley, UK) instead of radiographic films. Since the beginning of intensity-modulated radiation therapy treatments, the dosimetric quality control necessary before treating each new patient has been a time-consuming and therefore costly obligation. In order to fully develop this technique, it seems absolutely essential to reduce the cost of these controls, especially the linac time. Up to now, verification of the relative dosimetry field by field has been achieved by acquiring radiographic films in the isocenter plane and comparing them to the results of the XiO planning system (Computerized Medical Systems, Missouri, USA) using RIT113 v4.1 software (Radiological Imaging Technology, Colorado, USA). A qualitative and quantitative evaluation was realised for every field of every patient. A quick and simple procedure was put into place to be able to make the same verifications using portal images. This new technique is not a modification of the overall methodology of analysis. The results achieved by comparing the measurement with the electronic portal imaging device and the calculation with the treatment planning system were in line with those achieved with the films for all indicators we studied (isodoses, horizontal and vertical dose profiles and gamma index). (authors)

Performance of large electron energy filter in large volume plasma device

International Nuclear Information System (INIS)

Singh, S. K.; Srivastava, P. K.; Awasthi, L. M.; Mattoo, S. K.; Sanyasi, A. K.; Kaw, P. K.; Singh, R.

2014-01-01

This paper describes an in-house designed large Electron Energy Filter (EEF) utilized in the Large Volume Plasma Device (LVPD) [S. K. Mattoo, V. P. Anita, L. M. Awasthi, and G. Ravi, Rev. Sci. Instrum. 72, 3864 (2001)] to secure objectives of (a) removing the presence of remnant primary ionizing energetic electrons and the non-thermal electrons, (b) introducing a radial gradient in plasma electron temperature without greatly affecting the radial profile of plasma density, and (c) providing a control on the scale length of gradient in electron temperature. A set of 19 independent coils of EEF make a variable aspect ratio, rectangular solenoid producing a magnetic field (B x ) of 100 G along its axis and transverse to the ambient axial field (B z ∼ 6.2 G) of LVPD, when all its coils are used. Outside the EEF, magnetic field reduces rapidly to 1 G at a distance of 20 cm from the center of the solenoid on either side of target and source plasma. The EEF divides LVPD plasma into three distinct regions of source, EEF and target plasma. We report that the target plasma (n e ∼ 2 × 10 11  cm −3 and T e ∼ 2 eV) has no detectable energetic electrons and the radial gradients in its electron temperature can be established with scale length between 50 and 600 cm by controlling EEF magnetic field. Our observations reveal that the role of the EEF magnetic field is manifested by the energy dependence of transverse electron transport and enhanced transport caused by the plasma turbulence in the EEF plasma

Automated detection of a prostate Ni-Ti stent in electronic portal images.

Science.gov (United States)

Carl, Jesper; Nielsen, Henning; Nielsen, Jane; Lund, Bente; Larsen, Erik Hoejkjaer

2006-12-01

Planning target volumes (PTV) in fractionated radiotherapy still have to be outlined with wide margins to the clinical target volume due to uncertainties arising from daily shift of the prostate position. A recently proposed new method of visualization of the prostate is based on insertion of a thermo-expandable Ni-Ti stent. The current study proposes a new detection algorithm for automated detection of the Ni-Ti stent in electronic portal images. The algorithm is based on the Ni-Ti stent having a cylindrical shape with a fixed diameter, which was used as the basis for an automated detection algorithm. The automated method uses enhancement of lines combined with a grayscale morphology operation that looks for enhanced pixels separated with a distance similar to the diameter of the stent. The images in this study are all from prostate cancer patients treated with radiotherapy in a previous study. Images of a stent inserted in a humanoid phantom demonstrated a localization accuracy of 0.4-0.7 mm which equals the pixel size in the image. The automated detection of the stent was compared to manual detection in 71 pairs of orthogonal images taken in nine patients. The algorithm was successful in 67 of 71 pairs of images. The method is fast, has a high success rate, good accuracy, and has a potential for unsupervised localization of the prostate before radiotherapy, which would enable automated repositioning before treatment and allow for the use of very tight PTV margins.

Automated detection of a prostate Ni-Ti stent in electronic portal images

International Nuclear Information System (INIS)

Carl, Jesper; Nielsen, Henning; Nielsen, Jane; Lund, Bente; Larsen, Erik Hoejkjaer

2006-01-01

Planning target volumes (PTV) in fractionated radiotherapy still have to be outlined with wide margins to the clinical target volume due to uncertainties arising from daily shift of the prostate position. A recently proposed new method of visualization of the prostate is based on insertion of a thermo-expandable Ni-Ti stent. The current study proposes a new detection algorithm for automated detection of the Ni-Ti stent in electronic portal images. The algorithm is based on the Ni-Ti stent having a cylindrical shape with a fixed diameter, which was used as the basis for an automated detection algorithm. The automated method uses enhancement of lines combined with a grayscale morphology operation that looks for enhanced pixels separated with a distance similar to the diameter of the stent. The images in this study are all from prostate cancer patients treated with radiotherapy in a previous study. Images of a stent inserted in a humanoid phantom demonstrated a localization accuracy of 0.4-0.7 mm which equals the pixel size in the image. The automated detection of the stent was compared to manual detection in 71 pairs of orthogonal images taken in nine patients. The algorithm was successful in 67 of 71 pairs of images. The method is fast, has a high success rate, good accuracy, and has a potential for unsupervised localization of the prostate before radiotherapy, which would enable automated repositioning before treatment and allow for the use of very tight PTV margins

BELIEF Project: the Portal and the Digital Library

International Nuclear Information System (INIS)

Zoppi, F.; Calabro, G.

2007-01-01

BELIEF (Bringing Europes eLectronic Infrastructures to Expanding Frontiers) Project aim to create a platform where eInfrastructures providers and users can collaborate and exchange knowledge, which will help ensure that eInfrastructures are developed and used effectively worldwide, filling the gap separating the Research Infrastructure providers from the users, and thus contribute to the emergence of a competitive knowledge-based economy. To create this synergy of multi-disciplinary Research Infrastructure communities, BELIEF created a one-stop-shop for eInfrastructures communities providing online a Digital Library (DL) and a Portal with a search and contact facility, case studies, a discussion forum, eInfrastructures publications. Offline, it has organised events including brainstorming, networking workshops and international conferences and publications, since BELIEFs values are firmly rooted in international cooperation to the emerging economies, particularly of Latin America and India. The Portal and the DL are key parts of this project. There was an opportunity to provide a ready and common source of information on eInfrastructures, both for the users wanting to find out the supply, and for the providers wanting to extend user base and develop their systems. The Portal and the DL respond to this demand by supplying to researchers documentation that matches their search criteria precisely, according to their interest and professional profile. (Author)

[Predictive value of ultrasonography in portal hypertension].

Science.gov (United States)

Moreno, E; Torres, P; Trejo, C; Barra Ostoni, V; Ortega, C; Römer, H

1991-01-01

Portal hypertension is a common pathology in childhood and one of its most common causes is cavernomatosis of the portal vein. This obstruction causes hemodynamic changes which lead to splenomegaly and collateral circulation. Esophageal varices are one of the most important sequelae, which endanger the patient's life because of a bleeding tendency. Ecosonography helps to detect the thickening of the lesser omentum vis a vis the aortic diameter, caused by the collateral circulation. We studied 15 children presenting with portal hypertension resulting from portal vein cavernomatosis; we performed an upper GI endoscopy and abdominal ecosonography. The endoscopy revealed grade II esophageal varices in 20% of cases, the remaining 80% had grade III and grade IV. Ecosonography revealed an increased lesser omentum/aorta ratio in children with portal hypertension, compared to controls (p portal hypertension.

Techno-economic assessment of novel vanadium redox flow batteries with large-area cells

Science.gov (United States)

Minke, Christine; Kunz, Ulrich; Turek, Thomas

2017-09-01

The vanadium redox flow battery (VRFB) is a promising electrochemical storage system for stationary megawatt-class applications. The currently limited cell area determined by the bipolar plate (BPP) could be enlarged significantly with a novel extruded large-area plate. For the first time a techno-economic assessment of VRFB in a power range of 1 MW-20 MW and energy capacities of up to 160 MWh is presented on the basis of the production cost model of large-area BPP. The economic model is based on the configuration of a 250 kW stack and the overall system including stacks, power electronics, electrolyte and auxiliaries. Final results include a simple function for the calculation of system costs within the above described scope. In addition, the impact of cost reduction potentials for key components (membrane, electrode, BPP, vanadium electrolyte) on stack and system costs is quantified and validated.

Celecoxib ameliorates portal hypertension of the cirrhotic rats through the dual inhibitory effects on the intrahepatic fibrosis and angiogenesis.

Science.gov (United States)

Gao, Jin-Hang; Wen, Shi-Lei; Yang, Wen-Juan; Lu, Yao-Yao; Tong, Huan; Huang, Zhi-Yin; Liu, Zhang-Xu; Tang, Cheng-Wei

2013-01-01

Increased intra-hepatic resistance to portal blood flow is the primary factor leading to portal hypertension in cirrhosis. Up-regulated expression of cyclooxygenase-2 (COX-2) in the cirrhotic liver might be a potential target to ameliorate portal hypertension. To verify the effect of celecoxib, a selective inhibitor of COX-2, on portal hypertension and the mechanisms behind it. Cirrhotic liver model of rat was established by peritoneal injection of thiacetamide (TAA). 36 rats were randomly assigned to control, TAA and TAA+celecoxib groups. Portal pressures were measured by introduction of catheters into portal vein. Hepatic fibrosis was assessed by the visible hepatic fibrotic areas and mRNAs for collagen III and α-SMA. The neovasculature was determined by hepatic vascular areas, vascular casts and CD31 expression. Expressions of COX-2, vascular endothelial growth factor (VEGF), VEGF receptor-2 (VEGFR-2) and related signal molecules were quantitated. Compared with TAA group, the portal pressure in TAA+celecoxib group was significantly decreased by 17.8%, pportal venules. The data of fibrotic areas, CD31expression, mRNA levels of α-SMA and collagen III in TAA+celecoxib group were much lower than those in TAA group, pprotein levels of VEGF, VEGFR-2 and COX-2 induced by TAA was significantly inhibited after celecoxib treatment. The expressions of prostaglandin E2 (PGE2), phosphorylated extracellular signal-regulated kinase (p-ERK), hypoxia-inducible factor-1α (HIF-1α), and c-fos were also down-regulated after celecoxib treatment. Long term administration of celecoxib can efficiently ameliorate portal hypertension in TAA rat model by its dual inhibitory effects on the intrahepatic fibrosis and angiogenesis. The anti-angiogenesis effect afforded by celecoxib may attribute to its modulation on VEGF/VEGFR-2 through the down-regulation of integrated signal pathways involving PGE2- HIF-1α- VEGF and p-ERK- c-fos- VEGFR-2.

A large area detector for x-ray applications

International Nuclear Information System (INIS)

Rodricks, B.; Huang, Qiang; Hopf, R.; Wang, Kemei.

1993-01-01

A large area detector for x-ray synchrotron applications has been developed. The front end of this device consist of a scintillator coupled to a fiber-optic taper. The fiber-optic taper is comprised of 4 smaller (70 mm x 70 mm) tapers fused together in a square matrix giving an active area of 140 mm x 140 mm. Each taper has a demagnification of 5.5 resulting in four small ends that are 12 mm diagonally across. The small ends of each taper are coupled to four microchannel-plate-based image intensifiers. The output from each image intensifier is focused onto a Charge Coupled Device (CCD) detector. The four CCDs are read out in parallel and are independently controlled. The image intensifiers also act as fast (20 ns) electronic shutters. The system is capable of displaying images in real time. Additionally, with independent control on the readout of each row of data from the CCD, the system is capable of performing high speed imaging through novel readout manipulation

BRAZILIAN NEWS PORTALS CHARACTERISTICS

Directory of Open Access Journals (Sweden)

Heloiza G. Herckovitz

2011-02-01

Full Text Available A content analysis of four Brazilian news media portals found that economic news dominated the top headlines with little attention paid to education, the environment and welfare. Other trends included a focus on local events and national news sources, reliance on few sources, mostly official ones, and a low percentage of news that fitted the concept of newsworthiness (a combination of both social significance and deviance concepts. Other findings of a study of 432 top news stories published by UOL, Estadão, iG and Terra during a 15-day period between February and March 2008 indicate that the top portions of the portals’ front pages carry news that lacks story depth, editorial branding, and multimedia applications. The results suggest that online news portals are in their infancy although Brazil has the largest online population of Latin America. This study hopes to shed light on the gatekeeping process in Brazilian news portals. Brazilian media portals have yet to become a significant editorial force able to provide knowledge about social issues and public affairs in a socially responsible fashione.

Idiopathic noncirrhotic portal hypertension: current perspectives.

Science.gov (United States)

Riggio, Oliviero; Gioia, Stefania; Pentassuglio, Ilaria; Nicoletti, Valeria; Valente, Michele; d'Amati, Giulia

2016-01-01

The term idiopathic noncirrhotic portal hypertension (INCPH) has been recently proposed to replace terms, such as hepatoportal sclerosis, idiopathic portal hypertension, incomplete septal cirrhosis, and nodular regenerative hyperplasia, used to describe patients with a hepatic presinusoidal cause of portal hypertension of unknown etiology, characterized by features of portal hypertension (esophageal varices, nonmalignant ascites, porto-venous collaterals), splenomegaly, patent portal, and hepatic veins and no clinical and histological signs of cirrhosis. Physicians should learn to look for this condition in a number of clinical settings, including cryptogenic cirrhosis, a disease known to be associated with INCPH, drug administration, and even chronic alterations in liver function tests. Once INCPH is clinically suspected, liver histology becomes mandatory for the correct diagnosis. However, pathologists should be familiar with the histological features of INCPH, especially in cases in which histology is not only requested to exclude liver cirrhosis.

Teen Use of a Patient Portal: A Qualitative Study of Parent and Teen Attitudes

OpenAIRE

Bergman, David A.; Brown, Nancy L.; Wilson, Sandra

2008-01-01

We conducted a qualitative study of the attitudes of teens and parents toward the use of a patient portal. We conducted two teen and two parent focus groups, one teen electronic bulletin board, and one parent electronic bulletin board. Videotapes and transcripts from the groups were independently analyzed by two reviewers for significant themes, which were then validated by two other members ...

Large area high-speed metrology SPM system

International Nuclear Information System (INIS)

Klapetek, P; Valtr, M; Martinek, J; Picco, L; Payton, O D; Miles, M; Yacoot, A

2015-01-01

We present a large area high-speed measuring system capable of rapidly generating nanometre resolution scanning probe microscopy data over mm 2 regions. The system combines a slow moving but accurate large area XYZ scanner with a very fast but less accurate small area XY scanner. This arrangement enables very large areas to be scanned by stitching together the small, rapidly acquired, images from the fast XY scanner while simultaneously moving the slow XYZ scanner across the region of interest. In order to successfully merge the image sequences together two software approaches for calibrating the data from the fast scanner are described. The first utilizes the low uncertainty interferometric sensors of the XYZ scanner while the second implements a genetic algorithm with multiple parameter fitting during the data merging step of the image stitching process. The basic uncertainty components related to these high-speed measurements are also discussed. Both techniques are shown to successfully enable high-resolution, large area images to be generated at least an order of magnitude faster than with a conventional atomic force microscope. (paper)

Large area high-speed metrology SPM system

Science.gov (United States)

Klapetek, P.; Valtr, M.; Picco, L.; Payton, O. D.; Martinek, J.; Yacoot, A.; Miles, M.

2015-02-01

We present a large area high-speed measuring system capable of rapidly generating nanometre resolution scanning probe microscopy data over mm2 regions. The system combines a slow moving but accurate large area XYZ scanner with a very fast but less accurate small area XY scanner. This arrangement enables very large areas to be scanned by stitching together the small, rapidly acquired, images from the fast XY scanner while simultaneously moving the slow XYZ scanner across the region of interest. In order to successfully merge the image sequences together two software approaches for calibrating the data from the fast scanner are described. The first utilizes the low uncertainty interferometric sensors of the XYZ scanner while the second implements a genetic algorithm with multiple parameter fitting during the data merging step of the image stitching process. The basic uncertainty components related to these high-speed measurements are also discussed. Both techniques are shown to successfully enable high-resolution, large area images to be generated at least an order of magnitude faster than with a conventional atomic force microscope.

The Higgs Portal and Cosmology

Energy Technology Data Exchange (ETDEWEB)

Assamagan, Ketevi [Brookhaven National Lab. (BNL), Upton, NY (United States); Chen, Chien-Yi [Perimeter Inst. for Theoretical Physics, Waterloo, ON (Canada); Univ. of Victoria, BC (Canada); Chou, John Paul [Rutgers Univ., Piscataway, NJ (United States); Curtin, David [Univ. of Maryland, College Park, MD (United States); Fedderke, Michael A. [Univ. of Chicago, IL (United States); Gershtein, Yuri [Rutgers Univ., Piscataway, NJ (United States); He, Xiao-Gang [Shanghai Jiao Tong Univ. (China); Klute, Markus [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Kozaczuk, Jonathon [TRIUMF, Vancouver, BC (Canada); Kotwal, Ashutosh [Duke Univ., Durham, NC (United States); Lowette, Steven [Vrije Univ., Brussels (Belgium); No, Jose Miguel [Univ. of Sussex, Brighton (United Kingdom); Plehn, Tilman [Heidelberg Univ. (Germany); Qian, Jianming [Univ. of Michigan, Ann Arbor, MI (United States); Ramsey-Musolf, Michael [Univ. of Massachusetts, Amherst, MA (United States); Safonov, Alexei [Texas A & M Univ., College Station, TX (United States); Shelton, Jessie [Univ. of Illinois, Urbana-Champaign, IL (United States); Spannowsky, Michael [Durham Univ. (United Kingdom); Su, Shufang [Univ. of Arizona, Tucson, AZ (United States); Walker, Devin G. E. [Univ. of Washington, Seattle, WA (United States); Willocq, Stephane [Univ. of Massachusetts, Amherst, MA (United States); Winslow, Peter [Univ. of Massachusetts, Amherst, MA (United States)

2016-04-18

Higgs portal interactions provide a simple mechanism for addressing two open problems in cosmology: dark matter and the baryon asymmetry. In the latter instance, Higgs portal interactions may contain the ingredients for a strong first-order electroweak phase transition as well as new CP-violating interactions as needed for electroweak baryogenesis. These interactions may also allow for a viable dark matter candidate. We survey the opportunities for probing the Higgs portal as it relates to these questions in cosmology at the LHC and possible future colliders.

An analysis of splenoportographic findings in portal hypertension

Energy Technology Data Exchange (ETDEWEB)

Jung, Eun Mi; Moon, Sook Ran; Kim, Han Suk [National Medical Center, Seoul (Korea, Republic of); Park, Soo Soung [College of Medicine, Chung Ang University, Seoul (Korea, Republic of)

1983-12-15

Splenoportography has been proved as a useful method for the evaluation of circulatory disturbances in portal hypertension. Authors analyzed the various aspects of these disturbance on splenoportography in 22 cases that was performed under the clinical suspicion of portal hypertension during recent 6 years, from May, 1976 to July 1982 at the Department of Radiology, National Medical Center. The results were as follows: 1. Liver cirrhosis was the most frequent cause of intrahepatic obstruction type in portal hypertension (86%). 2. The portal pressure was more than 400 mmH{sub 2}0 in 67% of the cases (range; 300-540 mmH{sub 2}0). 3. In the majority of the cases, the higher the portal pressure was, the more dilated splenic and portal veins were. The diameter of portal vein was more than 15 mm in 79%, more than 21 mm in 47% of the cases (range; 10-26 mm). The diameter of splenic vein was more than 15 mm in 48% of the cases (range; 7-23 mm). Especially the diameter of splenic vein was larger than that of portal vein in 20% of the cases. 4. There was no definite correlation between the development of collateral circulation and the diameter of splenic and portal veins. 5. The filling of collateral circulation was definite sign of portal hypertension, though not regular. In portal hypertension, the collateral circulation was formed via coronary vein (91%), short gastric vein (64%), inferior mesenteric vein (36%). 6. Splenic-hilum time was delayed in 64% of the cases. Intrahepatic portal vein emptying time was more than 6 seconds in all the cases. 7. Most of the cases (91%) could be diagnosed as portal hypertension with vasculogram and hepatogram.

An analysis of splenoportographic findings in portal hypertension

International Nuclear Information System (INIS)

Jung, Eun Mi; Moon, Sook Ran; Kim, Han Suk; Park, Soo Soung

1983-01-01

Splenoportography has been proved as a useful method for the evaluation of circulatory disturbances in portal hypertension. Authors analyzed the various aspects of these disturbance on splenoportography in 22 cases that was performed under the clinical suspicion of portal hypertension during recent 6 years, from May, 1976 to July 1982 at the Department of Radiology, National Medical Center. The results were as follows: 1. Liver cirrhosis was the most frequent cause of intrahepatic obstruction type in portal hypertension (86%). 2. The portal pressure was more than 400 mmH 2 0 in 67% of the cases (range; 300-540 mmH 2 0). 3. In the majority of the cases, the higher the portal pressure was, the more dilated splenic and portal veins were. The diameter of portal vein was more than 15 mm in 79%, more than 21 mm in 47% of the cases (range; 10-26 mm). The diameter of splenic vein was more than 15 mm in 48% of the cases (range; 7-23 mm). Especially the diameter of splenic vein was larger than that of portal vein in 20% of the cases. 4. There was no definite correlation between the development of collateral circulation and the diameter of splenic and portal veins. 5. The filling of collateral circulation was definite sign of portal hypertension, though not regular. In portal hypertension, the collateral circulation was formed via coronary vein (91%), short gastric vein (64%), inferior mesenteric vein (36%). 6. Splenic-hilum time was delayed in 64% of the cases. Intrahepatic portal vein emptying time was more than 6 seconds in all the cases. 7. Most of the cases (91%) could be diagnosed as portal hypertension with vasculogram and hepatogram

Specific surface area evaluation method by using scanning electron microscopy

International Nuclear Information System (INIS)

Petrescu, Camelia; Petrescu, Cristian; Axinte, Adrian

2000-01-01

Ceramics are among the most interesting materials for a large category of applications, including both industry and health. Among the characteristic of the ceramic materials, the specific surface area is often difficult to evaluate.The paper presents a method of evaluation for the specific surface area of two ceramic powders by means of scanning electron microscopy measurements and an original method of computing the specific surface area.Cumulative curves are used to calculate the specific surface area under assumption that the values of particles diameters follow a normal logarithmic distribution. For two powder types, X7R and NPO the results are the following: - for the density ρ (g/cm 2 ), 5.5 and 6.0, respectively; - for the average diameter D bar (μm), 0.51 and 0.53, respectively; - for σ, 1.465 and 1.385, respectively; - for specific surface area (m 2 /g), 1.248 and 1.330, respectively. The obtained results are in good agreement with the values measured by conventional methods. (authors)

A Climate Information Portal for Copernicus: a central portal for European climate services?

Science.gov (United States)

Juckes, Martin; Swart, Rob; Thysse, Peter; Som de Cerff, Wim; Groot, Annemarie; Bennett, Victoria; Costa, Luis; Lückenkötter, Johannes; Callaghan, Sarah

2015-04-01

The FP7 project "Climate Information Portal for Copernicus" (CLIPC) is developing a demonstration portal for the Copernicus Climate Change Service (C3S). This project is one of a suite of FP7 research activities which are administratively independent of Copernicus, focussed on creating the technical and scientific building blocks needed for the service. It is to be expected that at EGU 2015 there will be many presentations describing portals delivering new and innovative ranges of services. It would be unwise to seek to replace all this creative activity with a single portal -- instead CLIPC is designing a portal to make distributed resources more accessible through flexible discovery systems. CLIPC needs to deliver more than a directory of resources: resources need to be presented in common protocols so that users can access multiple datasets. More information about the project objectives is available at www.clipc.eu. The gulf between the climate science communities and the end user communities is a central challenge being addressed in the project. It is important to understand that there is significant diversity and multiple communication barriers within these two sets of communities as well as between them. The CLIPC services must presentation will provide a review of progress towards this ambitious goal, through a discussion of user requirements activities, an overview of the proposed architecture, work on assessing and adjusting model biasses, and a discussion of the climate impact indicators which will be provided through the portal. When looking at the usability of data for the various users, CLIPC will implement a set of services functioning as a "knowledge base" supplying information to users about the data, including definitions of terminology used, quality of datasets, versioning, and user annotations.