243 research outputs found

    Thermo-mechanical stress simulation of unconstrained region of straight X20 steam pipe

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    The thermo-mechanical stress, strain and temperature distribution across the thickness of X20 steam pipe at region less susceptible to thermo-mechanical failure was simulated using finite element analysis software, Abaqus. The mesh convergence studies conducted showed that 10 mm mesh size was suitable for the simulation. The temperature distribution profile across the thickness of Pyrogel showed that pyrogel is an excellent insulation jacket for steam pipes. The maximum stress value obtained from the simulation shows that the pipe is operating below the yield strength of X20 steel at the region under study. Hence, the pipe’s failure at this region due to thermo-mechanical stress or strain only is practically impossible over a long period of time. A deviation of 0.5% was found to exist between the analytical and simulated stress value obtained. This indicates a strong correlation between the simulated and analytical stress results.Eskom and Tshwane University of Technology.https://www.journals.elsevier.com/procedia-manufacturingpm2020Mechanical and Aeronautical Engineerin

    Precision Measurement of PArity Violation in Polarized Cold Neutron Capture on the Proton: the NPDGamma Experiment

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    The NPDGamma experiment at the Los Alamos Neutron Science Center (LANSCE) is dedicated to measure with high precision the parity violating asymmetry in the γ\gamma emission after capture of spin polarized cold neutrons in para-hydrogen. The measurement will determine unambiguously the weak pion-nucleon-nucleon (πNN\pi NN) coupling constant {\it fπ1^1_{\pi}}Comment: Proceedings of the PANIC'05 Conference, Santa Fe, NM, USA, October 24-28, 2005, 3 pages, 2 figure

    A first-in-class, humanized antibody targeting alternatively spliced tissue factor: preclinical evaluation in an orthotopic model of pancreatic ductal adenocarcinoma

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    In 2021, pancreatic ductal adenocarcinoma (PDAC) is the 3(rd) leading cause of cancer deaths in the United States. This is largely due to a lack of symptoms and limited treatment options, which extend survival by only a few weeks. There is thus an urgent need to develop new therapies effective against PDAC. Previously, we have shown that the growth of PDAC cells is suppressed when they are co-implanted with RabMab1, a rabbit monoclonal antibody specific for human alternatively spliced tissue factor (asTF). Here, we report on humanization of RabMab1, evaluation of its binding characteristics, and assessment of its in vivo properties. hRabMab1 binds asTF with a K-D in the picomolar range; suppresses the migration of high-grade Pt45.P1 cells in Boyden chamber assays; has a long half-life in circulation (similar to 5 weeks); and significantly slows the growth of pre-formed orthotopic Pt45.P1 tumors in athymic nude mice when administered intravenously. Immunohistochemical analysis of tumor tissue demonstrates the suppression of i) PDAC cell proliferation, ii) macrophage infiltration, and iii) neovascularization, whereas RNAseq analysis of tumor tissue reveals the suppression of pathways that promote cell division and focal adhesion. This is the first proof-of-concept study whereby a novel biologic targeting asTF has been investigated as a systemically administered single agent, with encouraging results. Given that hRabMab1 has a favorable PK profile and is able to suppress the growth of human PDAC cells in vivo, it comprises a promising candidate for further clinical development.Thrombosis and Hemostasi

    Lubricating Bacteria Model for Branching growth of Bacterial Colonies

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    Various bacterial strains (e.g. strains belonging to the genera Bacillus, Paenibacillus, Serratia and Salmonella) exhibit colonial branching patterns during growth on poor semi-solid substrates. These patterns reflect the bacterial cooperative self-organization. Central part of the cooperation is the collective formation of lubricant on top of the agar which enables the bacteria to swim. Hence it provides the colony means to advance towards the food. One method of modeling the colonial development is via coupled reaction-diffusion equations which describe the time evolution of the bacterial density and the concentrations of the relevant chemical fields. This idea has been pursued by a number of groups. Here we present an additional model which specifically includes an evolution equation for the lubricant excreted by the bacteria. We show that when the diffusion of the fluid is governed by nonlinear diffusion coefficient branching patterns evolves. We study the effect of the rates of emission and decomposition of the lubricant fluid on the observed patterns. The results are compared with experimental observations. We also include fields of chemotactic agents and food chemotaxis and conclude that these features are needed in order to explain the observations.Comment: 1 latex file, 16 jpeg files, submitted to Phys. Rev.

    TUXEDO: a phase I/II trial of cetuximab with chemoradiotherapy in muscle-invasive bladder cancer

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    Objective: To assess the feasibility and preliminary efficacy of adding cetuximab to standard chemoradiotherapy for muscle-invasive bladder cancer. Patients and Methods: TUXEDO was a prospective, single-arm, open-label, phase I/II trial conducted in six UK hospitals. Cetuximab was administered with an initial loading dose of 400 mg/m2 on Day 1 of Week −1, and then seven weekly doses of 250 mg/m2. The radiotherapy schedule was 64 Gy/32F with Day 1 mitomycin C (12 g/m2) and 5-fluorouracil (500 mg/m2/day) over Days 1–5 and Days 22–26. Patients with T2-4aN0M0 urothelial cancer and a performance status of 0–1 were eligible. Prior neoadjuvant therapy was permitted. The Phase I primary outcome was impact on radiotherapy treatment completion and toxicity experienced during treatment. The Phase II primary outcome was local control at 3 months post treatment. Results: Between September 2012 and October 2016, 33 patients were recruited; seven in Phase I, 26 in Phase II. Three patients in Phase II were subsequently deemed ineligible and received no trial therapy. Eight patients discontinued cetuximab due to adverse effects. The patients’ median (range) age was 70.1 (60.6–75.1) years, 20 had a performance status of 0, 27 were male and 26 had already received neoadjuvant chemotherapy. In Phase I, all patients completed planned radiotherapy, with no delays or dose reductions. Of the 30 evaluable patients in Phase II, 25 had confirmed local control 3 months after treatment (77%, 95% confidence interval 58–90). During the trial there were 18 serious adverse events. The study was halted due to slow accrual. Conclusion: Phase I data demonstrate it is feasible and safe to add cetuximab to chemoradiotherapy. Exploratory analysis of Phase II data provides evidence to consider further clinical evaluation of cetuximab in this setting

    Maintenance Therapy With Tumor-Treating Fields Plus Temozolomide vs Temozolomide Alone for Glioblastoma: A Randomized Clinical Trial.

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    IMPORTANCE: Glioblastoma is the most devastating primary malignancy of the central nervous system in adults. Most patients die within 1 to 2 years of diagnosis. Tumor-treating fields (TTFields) are a locoregionally delivered antimitotic treatment that interferes with cell division and organelle assembly. OBJECTIVE: To evaluate the efficacy and safety of TTFields used in combination with temozolomide maintenance treatment after chemoradiation therapy for patients with glioblastoma. DESIGN, SETTING, AND PARTICIPANTS: After completion of chemoradiotherapy, patients with glioblastoma were randomized (2:1) to receive maintenance treatment with either TTFields plus temozolomide (n = 466) or temozolomide alone (n = 229) (median time from diagnosis to randomization, 3.8 months in both groups). The study enrolled 695 of the planned 700 patients between July 2009 and November 2014 at 83 centers in the United States, Canada, Europe, Israel, and South Korea. The trial was terminated based on the results of this planned interim analysis. INTERVENTIONS: Treatment with TTFields was delivered continuously (>18 hours/day) via 4 transducer arrays placed on the shaved scalp and connected to a portable medical device. Temozolomide (150-200 mg/m2/d) was given for 5 days of each 28-day cycle. MAIN OUTCOMES AND MEASURES: The primary end point was progression-free survival in the intent-to-treat population (significance threshold of .01) with overall survival in the per-protocol population (n = 280) as a powered secondary end point (significance threshold of .006). This prespecified interim analysis was to be conducted on the first 315 patients after at least 18 months of follow-up. RESULTS: The interim analysis included 210 patients randomized to TTFields plus temozolomide and 105 randomized to temozolomide alone, and was conducted at a median follow-up of 38 months (range, 18-60 months). Median progression-free survival in the intent-to-treat population was 7.1 months (95% CI, 5.9-8.2 months) in the TTFields plus temozolomide group and 4.0 months (95% CI, 3.3-5.2 months) in the temozolomide alone group (hazard ratio [HR], 0.62 [98.7% CI, 0.43-0.89]; P = .001). Median overall survival in the per-protocol population was 20.5 months (95% CI, 16.7-25.0 months) in the TTFields plus temozolomide group (n = 196) and 15.6 months (95% CI, 13.3-19.1 months) in the temozolomide alone group (n = 84) (HR, 0.64 [99.4% CI, 0.42-0.98]; P = .004). CONCLUSIONS AND RELEVANCE: In this interim analysis of 315 patients with glioblastoma who had completed standard chemoradiation therapy, adding TTFields to maintenance temozolomide chemotherapy significantly prolonged progression-free and overall survival. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00916409

    Racial and Ethnic Differences in Acceptability of Urine and Cervico-Vaginal Sample Self-Collection for HPV-Based Cervical Cancer Screening

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    Background: We compared women's acceptability of urine and cervico-vaginal sample self-collection for high-risk (oncogenic) human papillomavirus (hrHPV) testing and assessed whether acceptability varied across racial/ethnic groups. Methods: As part of a test accuracy study of urine-based hrHPV testing, we recruited a convenience sample of women 25-65 years of age at two colposcopy clinics in North Carolina between November 2016 and January 2019. After self-collection of urine and cervico-vaginal samples, women completed a questionnaire on the acceptability of the sample collection methods. We coded open-ended questions inductively. All results are presented stratified by racial/ethnic group. Results: We included 410 women (119 Hispanic, 115 non-Hispanic Black, 154 non-Hispanic White, and 22 women with other racial identities). Most women (79%, 95% confidence interval [CI] = 76%-83%) had positive feelings about urine-based hrHPV testing. Women generally preferred urine (78%, 95% CI = 74%-82%) over cervico-vaginal self-collection (18%, 95% CI = 14%-22%), but the degree differed by racial/ethnic group, increasing from 75% in non-Hispanic Black to 82% in Hispanic women (p = 0.011). Most women reported at least one positive aspect of urine (89%) and cervico-vaginal self-collection (85%) for hrHPV testing with the most common positive aspect being easy sample collection, although 16% of women were concerned about performing the cervico-vaginal self-collection correctly. Conclusions: Self-collection for hrHPV-based cervical cancer screening is highly acceptable to women across different racial/ethnic groups in the United States, and most women in our study would be more likely to attend future cervical cancer screening appointments if screening were urine based. Urine-based hrHPV testing is a promising approach to improve cervical cancer screening coverage

    Global assessment of dengue Virus-Specific CD4+ T cell responses in Dengue-Endemic areas

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    Background: Dengue is a major public health problem worldwide. Assessment of adaptive immunity is important to understanding immunopathology and to define correlates of protection against dengue virus (DENV). To enable global assessment of CD4+ T cell responses, we mapped HLA-DRB1-restricted DENV-specific CD4+ T cell epitopes in individuals previously exposed to DENV in the general population of the dengue-endemic region of Managua, Nicaragua. Methods: HLA class II epitopes in the population of Managua were identified by an in vitro IFNγ ELISPOT assay. CD4+ T cells purified by magnetic bead negative selection were stimulated with HLA-matched epitope pools in the presence of autologous antigen-presenting cells, followed by pool deconvolution to identify specific epitopes. The epitopes identified in this study were combined with those previously identified in the DENV endemic region of Sri Lanka, to generate a “megapool” (MP) consisting of 180 peptides specifically designed to achieve balanced HLA and DENV serotype coverage. The DENV CD4MP180 was validated by intracellular cytokine staining assays. Results: We detected responses directed against a total of 431 epitopes, representing all 4 DENV serotypes, restricted by 15 different HLA-DRB1 alleles. The responses were associated with a similar pattern of protein immunodominance, overall higher magnitude of responses, as compared to what was observed previously in the Sri Lanka region. Based on these epitope mapping studies, we designed a DENV CD4 MP180 with higher and more consistent coverage, which allowed the detection of CD4+ T cell DENV responses ex vivo in various cohorts of DENV exposed donors worldwide, including donors from Nicaragua, Brazil, Singapore, Sri Lanka, and U.S. domestic flavivirus-naïve subjects immunized with Tetravalent Dengue Live-Attenuated Vaccine (TV005). This broad reactivity reflects that the 21 HLA-DRB1 alleles analyzed in this and previous studies account for more than 80% of alleles present with a phenotypic frequency ≥5% worldwide, corresponding to 92% phenotypic coverage of the general population (i.e., 92% of individuals express at least one of these alleles). Conclusion: The DENV CD4 MP180 can be utilized to measure ex vivo responses to DENV irrespective of geographical location

    First cosmology results using SNe Ia from the dark energy survey: analysis, systematic uncertainties, and validation

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    International audienceWe present the analysis underpinning the measurement of cosmological parameters from 207 spectroscopically classified type Ia supernovae (SNe Ia) from the first three years of the Dark Energy Survey Supernova Program (DES-SN), spanning a redshift range of 0.01
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