913 research outputs found
Actual and Predicted Behavior of Large Metal Culverts
The stability of large metal culverts depends on the performance of the backfill around the pipe, which must be considered as a part of the structure when evaluating its safety. A simplified method to evaluate the current stability of such a structure on the basis of the structure\u27s shape is derived. Useful when limited amount of information is available, this method provides an economical procedure for: (1) evaluating the condition of the existing backfill and its capability to provide a safe support for the structure; (2) predicting final movements and determining if additional investigations are necessary to establish the safety of the structure; and (3) determining if measured deflections are in agreement with those predicted and, if not, determining if the safety of the structure is endangered by phenomena other than the expected behavior of surrounding soil (e.g. voids near pipe, soil erosion, non-symmetric loadings)
Chemotherapy-Response Monitoring of Breast Cancer Patients Using Quantitative Ultrasound-Based Intra-Tumour Heterogeneities
© 2017 The Author(s). Anti-cancer therapies including chemotherapy aim to induce tumour cell death. Cell death introduces alterations in cell morphology and tissue micro-structures that cause measurable changes in tissue echogenicity. This study investigated the effectiveness of quantitative ultrasound (QUS) parametric imaging to characterize intra-tumour heterogeneity and monitor the pathological response of breast cancer to chemotherapy in a large cohort of patients (n = 100). Results demonstrated that QUS imaging can non-invasively monitor pathological response and outcome of breast cancer patients to chemotherapy early following treatment initiation. Specifically, QUS biomarkers quantifying spatial heterogeneities in size, concentration and spacing of acoustic scatterers could predict treatment responses of patients with cross-validated accuracies of 82 ± 0.7%, 86 ± 0.7% and 85 ± 0.9% and areas under the receiver operating characteristic (ROC) curve of 0.75 ± 0.1, 0.80 ± 0.1 and 0.89 ± 0.1 at 1, 4 and 8 weeks after the start of treatment, respectively. The patients classified as responders and non-responders using QUS biomarkers demonstrated significantly different survivals, in good agreement with clinical and pathological endpoints. The results form a basis for using early predictive information on survival-linked patient response to facilitate adapting standard anti-cancer treatments on an individual patient basis
Синдром Буверета
According to the literature Bouveret’s syndrome is a rare disease with an unclear clinical picture and difficulties in diagnosis. The known diagnostic methods include X-ray examination, ultrasonography, computerized tomography, the endoscopic examination of the gastrointestinal tract. Researchers indicate that the most successful diagnosis can be made when combining ultrasound and contrast radiography. There isn’t a clear opinion about Bouveret’s
syndrome surgical treatment. Preference is given to the simple methods - enterotomy with the extraction of the biliary concrement leaving the elimination of the fistula and cholecystectomy for the second phase of treatment. In this case there appear a risk of the recurrence of biliary obstruction and the occurrence of cholangitis. A clinic case of a 62-year-old woman, who had difficulties in the diagnosis of biliary ileus has been described. The clinical picture has not corresponded to the X-ray examination results. The increase of obstruction syndrome and lack of the effect of conservative therapy have required a classical surgical treatment. In this case the solution of the problem has been reached by one stage treatment: cholecystectomy, enterotomy with gall stone extraction and the liquidation of gastric defect. The postoperative period has been complicated with a bilateral pleurisy, which has been
succesfully cured by carrying out the pleural puncture and antibiotic therapy.В соответствии с данными литературы, синдром Буверета – это редкое заболевание с неясной клинической картиной и сложной
диагностикой. Среди методов его диагностики наиболее известны рентгенологические методы, ультразвуковое исследование, компьютерная
томография, эндоскопическое исследование желудочно-кишечного тракта. Исследователи отмечают наибольшую вероятность успешной
диагностики при сочетании УЗИ с контрастным рентгенологическим исследованием. Нет единого мнения и относительно хирургического
лечения синдрома Буверета. Предпочтение отдаётся простым методам – энтеротомии с удалением желчного камня, при том, что ликвидация
свища и холецистэктомия остаются на второй этап лечения. Но, в этом случае остаётся опасность рецидива билиарной непроходимости и
возникновения холангита. Приводится клинический случай женщины 62 лет, у которой были трудности диагностики кишечной непроходимости
билиарного генеза. Клиническая картина не соответствовала данным рентгенологического исследования. Нарастание клиники кишечной
непроходимости и отсутствие эффекта от консервативной терапии потребовало хирургического лечения классическим способом. В нашем
случае решение проблемы достигнуто проведением одноэтапного лечения: холецистэктомия, энтеротомия с извлечением камня и закрытие
дефекта желудка. Послеоперационный период осложнился двухсторонним плевритом, который успешно вылечили посредством проведения
плевральной пункции и терапии антибиотиками
Peptide exchange on MHC-I by TAPBPR is driven by a negative allostery release cycle.
Chaperones TAPBPR and tapasin associate with class I major histocompatibility complexes (MHC-I) to promote optimization (editing) of peptide cargo. Here, we use solution NMR to investigate the mechanism of peptide exchange. We identify TAPBPR-induced conformational changes on conserved MHC-I molecular surfaces, consistent with our independently determined X-ray structure of the complex. Dynamics present in the empty MHC-I are stabilized by TAPBPR and become progressively dampened with increasing peptide occupancy. Incoming peptides are recognized according to the global stability of the final pMHC-I product and anneal in a native-like conformation to be edited by TAPBPR. Our results demonstrate an inverse relationship between MHC-I peptide occupancy and TAPBPR binding affinity, wherein the lifetime and structural features of transiently bound peptides control the regulation of a conformational switch located near the TAPBPR binding site, which triggers TAPBPR release. These results suggest a similar mechanism for the function of tapasin in the peptide-loading complex
Fluctuation-Induced Transitions in a Bistable Surface Reaction: Catalytic CO Oxidation on a Pt Field Emitter Tip
GYNOCARE Update: Modern Strategies to Improve Diagnosis and Treatment of Rare Gynecologic Tumors—Current Challenges and Future Directions
More than 50% of all gynecologic tumors can be classified as rare (defined as an incidence of ≤6 per 100,000 women) and usually have a poor prognosis owing to delayed diagnosis and treatment. In contrast to almost all other common solid tumors, the treatment of rare gynecologic tumors (RGT) is often based on expert opinion, retrospective studies, or extrapolation from other tumor sites with similar histology, leading to difficulty in developing guidelines for clinical practice. Currently, gynecologic cancer research, due to distinct scientific and technological challenges, is lagging behind. Moreover, the overall efforts for addressing these challenges are fragmented across different European countries and indeed, worldwide. The GYNOCARE, COST Action CA18117 (European Network for Gynecological Rare Cancer Research) programme aims to address these challenges through the creation of a unique network between key stakeholders covering distinct domains from concept to cure: basic research on RGT, biobanking, bridging with industry, and setting up the legal and regulatory requirements for international innovative clinical trials. On this basis, members of this COST Action, (Working Group 1, “Basic and Translational Research on Rare Gynecological Cancer”) have decided to focus their future efforts on the development of new approaches to improve the diagnosis and treatment of RGT. Here, we provide a brief overview of the current state-of-the-art and describe the goals of this COST Action and its future challenges with the aim to stimulate discussion and promote synergy across scientists engaged in the fight against this rare cancer worldwide
Diagnostic performance of FibroTest, SteatoTest and ActiTest in patients with NAFLD using the SAF score as histological reference
BACKGROUND: Blood tests of liver injury are less well validated in non‐alcoholic fatty liver disease (NAFLD) than in patients with chronic viral hepatitis. AIMS: To improve the validation of three blood tests used in NAFLD patients, FibroTest for fibrosis staging, SteatoTest for steatosis grading and ActiTest for inflammation activity grading. METHODS: We pre‐included new NAFLD patients with biopsy and blood tests from a single‐centre cohort (FibroFrance) and from the multicentre FLIP consortium. Contemporaneous biopsies were blindly assessed using the new steatosis, activity and fibrosis (SAF) score, which provides a reliable and reproducible diagnosis and grading/staging of the three elementary features of NAFLD (steatosis, inflammatory activity) and fibrosis with reduced interobserver variability. We used nonbinary‐ROC (NonBinAUROC) as the main endpoint to prevent spectrum effect and multiple testing. RESULTS: A total of 600 patients with reliable tests and biopsies were included. The mean NonBinAUROCs (95% CI) of tests were all significant (P < 0.0001): 0.878 (0.864–0.892) for FibroTest and fibrosis stages, 0.846 (0.830–0.862) for ActiTest and activity grades, and 0.822 (0.804–0.840) for SteatoTest and steatosis grades. FibroTest had a higher NonBinAUROC than BARD (0.836; 0.820–0.852; P = 0.0001), FIB4 (0.845; 0.829–0.861; P = 0.007) but not significantly different than the NAFLD score (0.866; 0.850–0.882; P = 0.26). FibroTest had a significant difference in median values between adjacent stage F2 and stage F1 contrarily to BARD, FIB4 and NAFLD scores (Bonferroni test P < 0.05). CONCLUSIONS: In patients with NAFLD, SteatoTest, ActiTest and FibroTest are non‐invasive tests that offer an alternative to biopsy, and they correlate with the simple grading/staging of the SAF scoring system across the three elementary features of NAFLD: steatosis, inflammatory activity and fibrosis
The EFSUMB Guidelines and Recommendations for Musculoskeletal Ultrasound - Part I: Extraarticular Pathologies
The first part of the guidelines and recommendations for musculoskeletal ultrasound, produced under the auspices of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB), provides information about the use of musculoskeletal ultrasound for assessing extraarticular structures (muscles, tendons, entheses, ligaments, bones, bursae, fasciae, nerves, skin, subcutaneous tissues, and nails) and their pathologies. Clinical applications, practical points, limitations, and artifacts are described and discussed for every structure. After an extensive literature review, the recommendations have been developed according to the Oxford Centre for Evidence-based Medicine and GRADE criteria and the consensus level was established through a Delphi process. The document is intended to guide clinical users in their daily practice
Increased variability in ApcMin/+ intestinal tissue can be measured with microultrasound
Altered tissue structure is a feature of many disease states and is usually measured by microscopic methods, limiting analysis to small areas. Means to rapidly and quantitatively measure the structure and organisation of large tissue areas would represent a major advance not just for research but also in the clinic. Here, changes in tissue organisation that result from heterozygosity in Apc, a precancerous situation, are comprehensively measured using microultrasound and three-dimensional high-resolution microscopy. Despite its normal appearance in conventionally examined cross-sections, both approaches revealed a significant increase in the variability of tissue organisation in Apc heterozygous tissue. These changes preceded the formation of aberrant crypt foci or adenoma. Measuring these premalignant changes using microultrasound provides a potential means to detect microscopically abnormal regions in large tissue samples, independent of visual examination or biopsies. Not only does this provide a powerful tool for studying tissue structure in experimental settings, the ability to detect and monitor tissue changes by microultrasound could be developed into a powerful adjunct to screening endoscopy in the clinic
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