Бандаж робочого колеса турбінного ступеня

Бандаж робочого колеса турбінного ступеня містить бандажну стрічку з отворами, що відповідають формі шипів робочих лопаток, просунутих в отвори бандажної стрічки, та допоміжне кільце з ущільнювальними гребенями на його зовнішній поверхні, яке надіте на бандажну стрічку. На зовнішній торцевій частині шипів робочих лопаток виконані виступи циліндричної, сферичної або конічної форми. На внутрішній частині допоміжного кільця з ущільнювальними гребенями створені лунки, розміри яких відповідають формі і розмірам зазначених виступів над шипами робочих лопаток

Анализ неоднородности почвенного покрова санитарно-защитной зоны воздушной линии электропередачи сверхвысокого напряжения

Объектом исследования являются земли санитарно-защитной зоны «ЛЭП ВЛ-500 кВ ПС "Итатская"-ПС "Ново-Анжерская" № 524» (кадастровый номер 42.00.2.41). Цель работы: оценка неоднородности земель санитарно-защитной зоны воздушной линии электропередач сверхвысокого напряжения по степени нарушенности почвенного покрова южной тайги Западной Сибири. В работе использованы натурные полевые обследования почвенного покрова санитарно-защитной зоны воздушной линии электропередачи сверхвысокого напряжения. В результате работы составлена карта антропогенных механических нарушений почвенного покрова санитарно-защитной зоны воздушной линии электропередачи сверхвысокого напряжения. Проанализированы почвенные нарушения по характеру распространения, форме и степени нарушенности.The object of the study are soil sanitary protection zone «Power transmission lines of 500 kV Substation «Itatsky» -PC «New-Anzherka» № 524" (cadastral number42.00.2.41). Objective: To assess heterogeneity of land sanitary protection zone of overhead power lines EHV according to the degree of soil disturbance of the southern taiga of Western Siberia. In the work used field survey of the soil cover of the sanitary protection zone of overhead power lines EHV. As a result of work compiled a map anthropogenic mechanical soil disturbance sanitary protection zone of overhead power lines EHV. Analyzed soil disturbances on the character of propagation, form and extent of the breach

Decline of emergency admissions for cardiovascular and cerebrovascular events after the outbreak of COVID-19

Background The spread of the novel coronavirus SARS-CoV-2 and the guidance from authorities for social distancing and media reporting lead to significant uncertainty in Germany. Concerns have been expressed regarding the underdiagnosing of harmful diseases. We explored the rates of emergency presentations for acute coronary syndrome (ACS) and acute cerebrovascular events (ACVE) before and after spread of SARS-CoV-2. Methods We analyzed all-cause visits at a tertiary university emergency department and admissions for ACS and ACVE before (calendar weeks 1–9, 2020) and after (calendar weeks 10–16, 2020) the first coronavirus disease (COVID-19) case in the region of the Saarland, Germany. The data were compared with the same period of the previous year. Results In 2020 an average of 346 patients per week presented at the emergency department whereas in 2019 an average of 400 patients presented up to calendar week 16 (p = 0.018; whole year 2019 = 395 patients per week). After the first COVID-19 diagnosis in the region, emergency department visit volume decreased by 30% compared with the same period in 2019 (p = 0.0012). Admissions due to ACS decreased by 41% (p = 0.0023 for all; Δ − 71% (p = 0.007) for unstable angina, Δ − 25% (p = 0.42) for myocardial infarction with ST-elevation and Δ − 17% (p = 0.28) without ST-elevation) compared with the same period in 2019 and decreased from 142 patients in calendar weeks 1–9 to 62 patients in calendar weeks 10–16. ACVE decreased numerically by 20% [p = 0.25 for all; transient ischemic attack: Δ − 32% (p = 0.18), ischemic stroke: Δ − 23% (p = 0.48), intracerebral haemorrhage: Δ + 57% (p = 0.4)]. There was no significant change in ACVE per week (p = 0.7) comparing calendar weeks 1–9 (213 patients) and weeks 10–16 (147 patients). Testing of 3756 samples was performed to detect 58 SARS-CoV-2 positive patients (prevalence 1,54%, thereof one patient with myocardial and two with cerebral ischemia) up to calendar week 16 in 2020. Conclusions The COVID-19 pandemic was associated with a significant decrease in all-cause admission and admissions due to cardiovascular events in the emergency department. Regarding acute cerebrovascular events there was a numerical decrease but no significant difference

One-step selection of Vaccinia virus-binding DNA aptamers by MonoLEX

<p>Abstract</p> <p>Background</p> <p>As a new class of therapeutic and diagnostic reagents, more than fifteen years ago RNA and DNA aptamers were identified as binding molecules to numerous small compounds, proteins and rarely even to complete pathogen particles. Most aptamers were isolated from complex libraries of synthetic nucleic acids by a process termed SELEX based on several selection and amplification steps. Here we report the application of a new one-step selection method (MonoLEX) to acquire high-affinity DNA aptamers binding Vaccinia virus used as a model organism for complex target structures.</p> <p>Results</p> <p>The selection against complete Vaccinia virus particles resulted in a 64-base DNA aptamer specifically binding to orthopoxviruses as validated by dot blot analysis, Surface Plasmon Resonance, Fluorescence Correlation Spectroscopy and real-time PCR, following an aptamer blotting assay. The same oligonucleotide showed the ability to inhibit <it>in vitro </it>infection of Vaccinia virus and other orthopoxviruses in a concentration-dependent manner.</p> <p>Conclusion</p> <p>The MonoLEX method is a straightforward procedure as demonstrated here for the identification of a high-affinity DNA aptamer binding Vaccinia virus. MonoLEX comprises a single affinity chromatography step, followed by subsequent physical segmentation of the affinity resin and a single final PCR amplification step of bound aptamers. Therefore, this procedure improves the selection of high affinity aptamers by reducing the competition between aptamers of different affinities during the PCR step, indicating an advantage for the single-round MonoLEX method.</p

Polen und Deutschland vor 1000 Jahren

Der Begegnung Kaiser Ottos III. und des Herzogs Boleslaw Chrobry zu Gnesen im Winter des Jahres 1000 ist anläßlich des Millenniums in Polen und Deutschland vielfach gedacht worden. Nirgends aber fanden sich führende Fachhistoriker beider Länder in so großer Zahl zusammen wie zur Berliner Tagung am 28. und 29. Januar 2000 im Institut für vergleichende Geschichte Europas im Mittelalter an der Humboldt-Universität zu Berlin. Der "Akt von Gnesen" gilt in der Geschichtswissenschaft als Sternstunde in der Geschichte der polnisch-deutschen Beziehungen, als welthistorisches Ereignis, das der künftigen polnisch/westslawisch-ungarisch-deutschen Region seinen Stempel aufgedrückt hat

HIV Drug Resistance (HIVDR) in Antiretroviral Therapy-Naïve Patients in Tanzania Not Eligible for WHO Threshold HIVDR Survey Is Dramatically High

The World Health Organization (WHO) has recommended guidelines for a HIV drug resistance (HIVDR) survey for resource-limited countries. Eligibility criteria for patients include age below 25 years in order to focus on the prevalence of transmitted HIVDR (tHIVDR) in newly-infected individuals. Most of the participating sites across Africa have so far reported tHIVDR prevalences of below 5%. In this study we investigated whether the rate of HIVDR in patients <25 years is representative for HIVDR in the rest of the therapy-naïve population. HIVDR was determined in 88 sequentially enrolled ART-naïve patients from Mwanza, Tanzania (mean age 35.4 years). Twenty patients were aged <25 years and 68 patients were aged 25-63 years. The frequency of HIVDR in the study population was 14.8% (95%; CI 0.072-0.223) and independent of NVP-resistance induced by prevention of mother-to-child transmission programs. Patients >25 years had a significantly higher HIVDR frequency than younger patients (19.1%; 95% CI 0.095-0.28) versus 0%, P = 0.0344). In 2 out of the 16 patients with HIVDR we found traces of antiretrovirals (ARVs) in plasma. ART-naïve patients aged over 25 years exhibited significantly higher HIVDR than younger patients. Detection of traces of ARVs in individuals with HIVDR suggests that besides transmission, undisclosed misuse of ARVs may constitute a significant factor in the generation of the observed high HIVDR rate. The current WHO tHIVDR survey that is solely focused on the transmission of HIVDR and that excludes patients over 25 years of age may therefore result in substantial underestimation of the prevalence of HIVDR in the therapy-naïve population. Similar studies should be performed also in other areas to test whether the so far reported optimistic picture of low HIVDR prevalence in young individuals is really representative for the rest of the ART-naïve HIV-infected population

Two-dimensional wave patterns of spreading depolarization: retracting, re-entrant, and stationary waves

We present spatio-temporal characteristics of spreading depolarizations (SD) in two experimental systems: retracting SD wave segments observed with intrinsic optical signals in chicken retina, and spontaneously occurring re-entrant SD waves that repeatedly spread across gyrencephalic feline cortex observed by laser speckle flowmetry. A mathematical framework of reaction-diffusion systems with augmented transmission capabilities is developed to explain the emergence and transitions between these patterns. Our prediction is that the observed patterns are reaction-diffusion patterns controlled and modulated by weak nonlocal coupling. The described spatio-temporal characteristics of SD are of important clinical relevance under conditions of migraine and stroke. In stroke, the emergence of re-entrant SD waves is believed to worsen outcome. In migraine, retracting SD wave segments cause neurological symptoms and transitions to stationary SD wave patterns may cause persistent symptoms without evidence from noninvasive imaging of infarction

Comparison of Plasmodium berghei challenge models for the evaluation of pre-erythrocytic malaria vaccines and their effect on perceived vaccine efficacy

<p>Abstract</p> <p>Background</p> <p>The immunological mechanisms responsible for protection against malaria infection vary among <it>Plasmodium </it>species, host species and the developmental stage of parasite, and are poorly understood. A challenge with live parasites is the most relevant approach to testing the efficacy of experimental malaria vaccines. Nevertheless, in the mouse models of <it>Plasmodium berghei </it>and <it>Plasmodium yoelii</it>, parasites are usually delivered by intravenous injection. This route is highly artificial and particularly in the <it>P. berghei </it>model produces inconsistent challenge results. The initial objective of this study was to compare an optimized intravenous (IV) delivery challenge model with an optimized single infectious mosquito bite challenge model. Finding shortcomings of both approaches, an alternative approach was explored, <it>i.e</it>., the subcutaneous challenge.</p> <p>Methods</p> <p>Mice were infected with <it>P. berghei </it>sporozoites by intravenous (tail vein) injection, single mosquito bite, or subcutaneous injection of isolated parasites into the subcutaneous pouch at the base of the hind leg. Infection was determined in blood smears 7 and 14 days later. To determine the usefulness of challenge models for vaccine testing, mice were immunized with circumsporozoite-based DNA vaccines by gene gun.</p> <p>Results</p> <p>Despite modifications that allowed infection with a much smaller than reported number of parasites, the IV challenge remained insufficiently reliable and reproducible. Variations in the virulence of the inoculum, if not properly monitored by the rigorous inclusion of sporozoite titration curves in each experiment, can lead to unacceptable variations in reported vaccine efficacies. In contrast, mice with different genetic backgrounds were consistently infected by a single mosquito bite, without overwhelming vaccine-induced protective immune responses. Because of the logistical challenges associated with the mosquito bite model, the subcutaneous challenge route was optimized. This approach, too, yields reliable challenge results, albeit requiring a relatively large inoculum.</p> <p>Conclusions</p> <p>Although a single bite by <it>P. berghei </it>infected <it>Anopheles </it>mosquitoes was superior to the IV challenge route, it is laborious. However, any conclusive evaluation of a pre-erythrocytic malaria vaccine candidate should require challenge through the natural anatomic target site of the parasite, the skin. The subcutaneous injection of isolated parasites represents an attractive compromise. Similar to the mosquito bite model, it allows vaccine-induced antibodies to exert their effect and is, therefore not as prone to the artifacts of the IV challenge.</p