Comparison of agar gel immunodiffusion test, enzyme-linked immunosorbent assay and PCR in diagnostics of enzootic bovine leukosis

Bovine leukaemia virus (BLV) is a retrovirus that induces a chronic infection in cattle. Once infected, cattle remain virus carriers for life and start to show an antibody response within a few weeks after infection. Eradication and control of the disease are based on early diagnostics and segregation of the carriers. The choice of a diagnostic method depends on the eradication programme, money resources and characteristics of the herd to be analysed. The agar gel immunodiffusion (AGID) test has been the serological test of choice for routine diagnosis of serum samples. Nevertheless, in more recent years, the enzyme-linked immunosorbent assay (ELISA) has replaced the AGID for large scale testing. For this purpose, commercially available BLV-ELISA kits were compared to the AGID and to the polymerase chain reaction (PCR) method performed with two sets of primers, amplifying env region. The ELISA kit based on the p24 core protein was found to be less specific and served as a screening test. The ELISA kit based on the envelope glycoprotein (gpSI) served as a verification test and gave a good correlation with the AGID test and PCR method. However, ELISA showed a higher sensitivity than AGID. The p24 based ELiSA was useful for screening a large number of samples, whereas gp51 based ELISA, AGID and PCR were more important for detecting the antibody response against the individual BLV-proteins and therefore for verification of the infection with BLV

Quality assessment of vascular access procedures for hemodialysis: A position paper of the Vascular Access Society based on the analysis of existing guidelines

Quality assessment in vascular access procedures for hemodialysis is not clearly defined. The aim of this article is to compare various guidelines regarding recommendation on quality control in angioaccess surgery. The overall population of end-stage renal disease patients and patients in need for hemodialysis treatment is growing every year. Chronic intermittent hemodialysis is still the main therapy. The formation of a functional angioaccess is the cornerstone in the management of those patients. Native (autologous) arteriovenous fistula is the best vascular access available. A relatively high percentage of primary failure and fistula abandonment increases the need for quality control in this field of surgery. There are very few recommendations of quality assessment on creation of a vascular access for hemodialysis in the searched guidelines. Some guidelines recommend the proportion of native arteriovenous fistula in incident and prevalent patients as well as the maximum tolerable percentage of central venous catheters and complications. According to some guidelines, surgeon's experience and expertise have a considerable influence on outcomes. There are no specific recommendations regarding surgeon's specialty, grade, level of skills, and experience. In conclusion, there is a weak recommendation in the guidelines on quality control in vascular access surgery. Quality assessment criteria should be defined in this field of surgery. According to these criteria, patients and nephrologists could choose the best vascular access center or surgeon. Centers with best results should be referral centers, and centers with poorer results should implement quality improvement programs

Validation of a patient-specific hemodynamic computational model for surgical planning of vascular access in hemodialysis patients

Vascular access dysfunction is one of the main causes of morbidity and hospitalization in hemodialysis patients. This major clinical problem points out the need for prediction of hemodynamic changes induced by vascular access surgery. Here we reviewed the potential of a patient-specific computational vascular network model that includes vessel wall remodeling to predict blood flow change within 6 weeks after surgery for different arteriovenous fistula configurations. For model validation, we performed a multicenter, prospective clinical study to collect longitudinal data on arm vasculature before and after surgery. Sixty-three patients with newly created arteriovenous fistula were included in the validation data set and divided into four groups based on fistula configuration. Predicted brachial artery blood flow volumes 40 days after surgery had a significantly high correlation with measured values. Deviation of predicted from measured brachial artery blood flow averaged 3% with a root mean squared error of 19.5%, showing that the computational tool reliably predicted patient-specific blood flow increase resulting from vascular access surgery and subsequent vascular adaptation. This innovative approach may help the surgeon to plan the most appropriate fistula configuration to optimize access blood flow for hemodialysis, potentially reducing the incidence of vascular access dysfunctions and the need of patient hospitalization

Navier-Stokes Simulation of a Heavy Lift Slowed-Rotor Compound Helicopter Configuration

Time accurate numerical simulations were performed using the Reynolds-averaged Navier-Stokes (RANS) flow solver OVERFLOW for a heavy lift, slowed-rotor, compound helicopter configuration, tested at the NASA Langley 14- by 22-Foot Subsonic Tunnel. The primary purpose of these simulations is to provide support for the development of a large field of view Particle Imaging Velocimetry (PIV) flow measurement technique supported by the Subsonic Rotary Wing (SRW) project under the NASA Fundamental Aeronautics program. These simulations provide a better understanding of the rotor and body wake flows and helped to define PIV measurement locations as well as requirements for validation of flow solver codes. The large field PIV system can measure the three-dimensional velocity flow field in a 0.914m by 1.83m plane. PIV measurements were performed upstream and downstream of the vertical tail section and are compared to simulation results. The simulations are also used to better understand the tunnel wall and body/rotor support effects by comparing simulations with and without tunnel floor/ceiling walls and supports. Comparisons are also made to the experimental force and moment data for the body and rotor

Weyl's law and quantum ergodicity for maps with divided phase space

For a general class of unitary quantum maps, whose underlying classical phase space is divided into several invariant domains of positive measure, we establish analogues of Weyl's law for the distribution of eigenphases. If the map has one ergodic component, and is periodic on the remaining domains, we prove the Schnirelman-Zelditch-Colin de Verdiere Theorem on the equidistribution of eigenfunctions with respect to the ergodic component of the classical map (quantum ergodicity). We apply our main theorems to quantised linked twist maps on the torus. In the Appendix, S. Zelditch connects these studies to some earlier results on `pimpled spheres' in the setting of Riemannian manifolds. The common feature is a divided phase space with a periodic component.Comment: Colour figures. Black & white figures available at http://www2.maths.bris.ac.uk/~majm. Appendix by Steve Zelditc

An Early Study on the Mechanisms that Allow Tissue-Engineered Vascular Grafts to Resist Intimal Hyperplasia

Intimal hyperplasia is one of the prominent failure mechanisms for arteriovenous fistulas and arteriovenous access grafts. Human tissue-engineered vascular grafts (TEVGs) were implanted as arteriovenous grafts in a novel baboon model. Ultrasound was used to monitor flow rates and vascular diameters throughout the study. Intimal hyperplasia in the outflow vein of TEVGs was assessed at the anastomosis and at juxta-anastomotic regions via histological analysis, and was compared to intimal hyperplasia with polytetrafluoroethylene (PTFE) grafts in the baboon model and in literature reports from other animal models. Less venous intimal hyperplasia was observed in histological sections with arteriovenous TEVGs than with arteriovenous PTFE grafts. TEVGs were associated with a mild, noninflammatory intimal hyperplasia. The extent of intimal tissue that formed with TEVG placement correlated with the rate of blood flow through tissue engineered vascular grafts at 2 weeks postimplant. Outflow vein dilatation was observed with increased flow rate. Both mid-graft flow rates and outflow vein diameters reached a plateau by week 4, which suggested that venous remodeling and intimal hyperplasia largely occurred within the first 4 weeks of implant in the baboon model. Given their compliant and noninflammatory nature, TEVGs appear resistant to triggers for venous intimal hyperplasia that are common for PTFE arteriovenous grafts, including (1) abundant proinflammatory macrophage populations that are associated with PTFE grafts and (2) compliance mismatch between PTFE grafts and the outflow vein. Our findings suggest that arteriovenous TEVGs develop only a mild form of venous intimal hyperplasia, which results from the typical hemodynamic changes that are associated with arteriovenous settings

Manual for use of Al-containing residues in low-carbon mineral binders

Our society can no longer be imagined without its modern infrastructure, which is inevitably based on the use of various mineral and metallic materials and requires a high energy consumption. Parallel to the production of materials, as well as the production of electricity, huge amounts of various industrial and mining residues (waste/by-product) are generated and many of them are sent to landfill. The European Union (EU) aims to increase resource efficiency and the supply of ”secondary raw materials“ through recycling [1], inventory of waste from extractive industries [2], and waste prevention, waste re-use and material recycling [3]. Much of the industrial and mining waste is enriched with aluminium (Al) and therefore has a potential to replace natural sources of Al in mineral binders with a high Al demand. However, the use of industrial residue in mineral binders requires an extensive knowledge of its chemical composition, including potential hazardous components (e.g. mercury), mineral composition, organic content, radioactivity and physical properties (moisture content, density, etc.). This manual addresses the legislative aspects, governing the use of secondary raw materials in construction products, description of the most common Al-containing industrial and mining residue (bauxite deposits, red mud, ferrous slag, ash and some other by products from industry), potentiality for their reutilisation and its economic aspects, potential requirements/barriers for the use of secondary raw materials in the cement industry and a description of belite-sulfoaluminate cements, which are a promising solution for implementing the circular economy through the use of large amounts of landfilled Al-rich industrial residue and mining waste cement clinker raw mixture. This manual was prepared by partners of the RIS-ALiCE project. It provides a popular content, which targets relevant stakeholders as well as the wider society. Moreover, it offers education material for undergraduate, master and PhD students.Other links: [http://www.zag.si/dl/manual-alice.pdf

Оптимизация конструкции захвата для детали «Барабан»

Грузозахватные приспособления обычно применяются при производстве работ по подъему и перемещению грузов с применением грузоподъемных машин. Использование приспособлений позволяет реализовать максимальное удобство и безопасность производственного процесса. Грузозахватные приспособления конструируются для определенного этапа технологического процесса, для конкретного изделия. При проектировании таких приспособлений необходимо учитывать основные показатели оптимальности конструкции: прочность, надежность, простота, удобство и безопасность при эксплуатации, эргономичность. Кроме того, нужно стремиться к наименьшей массе и, соответственно, металлоемкости захвата. Конструкция грузозахватного приспособления, в основном, будет зависеть от назначенных технологом поверхностей, за которые можно крепиться и от максимальной высоты подъема крюка крана. В статье описана задача по конструированию захвата для детали «Барабан¬ в новом технологическом процессе. Рассмотрена конструкция существующего захвата, взятого за прототип. Приведен анализ различных вариантов конструктивных решений, созданных в процессе проектирования. Выбран вариант конструкции захвата, который в наибольшей степени соответствует требованиям технического задания. Конструкция этого модернизированного приспособления представляет собой захват с тремя лапами, удерживающими деталь, и подвес в виде траверсы. Разработанная конструкторская документация утверждена производством и отделом промышленной безопасности