185 research outputs found
Электростатическое выделение титана из катодного осадка после электролиза расплава KF • K Cl • K 2TiF6-TiO2
Технология сборки и сварки хребтовой балки рамы железнодорожной платформы
При производстве деталей вагонов поездов особое значение отдается технологии сборки и сварки, от которой будет зависеть качество и работоспособность конструкции. Одной из наиболее нагруженных деталей вагона является хребтовая балка. Хребтовая балка служит для крепления на ней автосцепного и тормозного оборудования.
Предметом изучения является технология автоматической сварки под слоем флюса плавящимся электродом. Объектом изучения в выпускной квалификационной работе является технология изготовления хребтовой балки. Цель работы – является разработка технологического процесса сборки и автоматической сварки под слоем флюса вагонной хребтовой.In the production of train car parts, special emphasis is given to assembly and welding technology, on which the quality and performance of the structure will depend. One of the most loaded parts of the car is a spinal beam. Spinal beam serves to attach the auto-coupling and brake equipment on it.
The subject of study is the technology of automatic welding under a layer of flux by a consumable electrode. The object of study in the final qualifying work is the technology of making a spinal beam.
The purpose of the work is the development of the technological process of assembly and automatic welding under a layer of flux wagon spinal
Исследование физико-химических характеристик нефтяных газов Лугинецкого месторождения
Объектами исследования являются: сырьевой газ F-450, газ сухой отбензиненный SK-625, топливный газ высокого давления. Цель работы – исследование физико-химических характеристик нефтяных газов Лугинецкого месторождения. В процессе исследования проводились испытания проб газа. Состав газа проанализирован в динамике за 3 месяца. Результаты исследования позволяют сделать выводы о том, что газ имеет стабильный состав – содержание всех компонентов меняется незначительно. Область применения: полученные результаты могут быть использованы в отчетной документации Лугенецкого газоконденсатного месторождения.Objects of research are: raw F-450 gas, gas dry stripped SK-625, fuel gas of a high pressure. The work purpose – research of physical and chemical characteristics of oil gases of the Luginetsky field. In the course of research tests of tests of gas were carried out. The composition of gas is analysed in dynamics in 3 months. Results of research allow to draw conclusions that gas has stable structure – the maintenance of all components changes slightly. Scope: the received results can be used in reporting documentation of the Lugenetsky gas-condensate field
Анализ термодинамических параметров нефтепровода с предварительным подогревом нефти в условиях Севера
Объектом исследования является трубопровод, на котором применяется технология перекачки нефти с предварительным подогревом. Цель работы – определить влияние термодинамических характеристик трубопроводного транспорта нефти в условиях Севера на эффективность технологии перекачки нефти с предварительным подогревом. В процессе исследования проводились гидравлические и тепловые расчеты, расчет оптимальной температуры транспорта, расчет экономической эффективности использования технологии транспорта с подогревом. Рассмотрены вопросы корректного описания вязкостно-температурной характеристики нефти для определения оптимальной температуры подогрева нефти, влияния термодинамических параметров системы «нефтепровод-окружающая среда» на эффективность применения предварительного подогрева.The object of research is the hot oil pipeline. Purpose - to determine the influence of the thermodynamic characteristics of the pipeline transport of oil in the North on the effectiveness of technology of hot oil transfer.
The study carried out hydraulic and thermal calculations, the calculation of optimal transport temperature, calculation of economic efficiency of use of hot oil transport. The questions of the correct description of viscosity-temperature characteristics of the oil to determine the optimum temperature of heating oil, the effect of thermodynamic parameters of the system "pipeline-environment" on the effectiveness of transport. Presents measures for health and safety point of operation of oil heating, environmental protection, technical and economic part
Interictal abnormal fMRI activation of visual areas during a motor task cued by visual stimuli in migraine
Beta-blocker migraine prophylaxis affects the excitability of the visual cortex as revealed by transcranial magnetic stimulation
The objective of this study is to assess effects of beta-blocker migraine prophylaxis on cortical excitability determined by transcranial magnetic stimulation (TMS). Phosphene and motor thresholds (PT, MT) were investigated in 29 patients with migraine, in 15 of them prior to and following preventive medication with metoprolol and in 14 patients without prophylaxis. Following prophylaxis headache frequency significantly decreased (p = 0.005) and mean PT were significantly increased (51.5 ± 7.5 vs. 63.6 ± 8.4%) compared to patients without preventive treatment (53.7 ± 5.3 vs. 52.3 ± 6.3%; p = 0.040). Mean MT did not significantly differ either between groups or due to treatment. In the group of all patients, a significant inverse correlation between headache frequency and the level of PT was found (R = −0.629; p < 0.01). There was, however, no significant correlation in the subgroups of patients. We conclude that (a) clinical efficacy of beta-blocker treatment in migraine could be (at least partly) linked to its ability to modulate the excitability of the visual cortex and (b) the PT determined by TMS appears suitable to assess the effects of prophylaxis on cortical excitability in the individual patient. This may be useful in clinical trials investigating migraine preventive drugs
Accurate and Rapid Estimation of Phosphene Thresholds (REPT)
To calibrate the intensity of transcranial magnetic stimulation (TMS) at the occipital pole, the phosphene threshold is used as a measure of cortical excitability. The phosphene threshold (PT) refers to the intensity of magnetic stimulation that induces illusory flashes of light (phosphenes) on a proportion of trials. The existing PT estimation procedures lack the accuracy and mathematical rigour of modern threshold estimation methods. We present an improved and automatic procedure for estimating the PT which is based on the well-established Ψ Bayesian adaptive staircase approach. To validate the new procedure, we compared it with another commonly used procedure for estimating the PT. We found that our procedure is more accurate, reliable, and rapid when compared with an existing PT measurement procedure. The new procedure is implemented in Matlab and works automatically with the Magstim Rapid2 stimulator using a convenient graphical user interface. The Matlab program is freely available for download
Zilucoplan in immune-mediated necrotising myopathy: a phase 2, randomised, double-blind, placebo-controlled, multicentre trial
BACKGROUND:
Immune-mediated necrotising myopathy is an autoimmune myopathy characterised by proximal muscle weakness, high creatine kinase concentrations, and autoantibodies recognising 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) or the signal recognition particle (SRP). No approved therapies exist for people with immune-mediated necrotising myopathy. Previous studies have suggested that complement activation might be pathogenic in immune-mediated necrotising myopathy; therefore, zilucoplan, a complement C5 (C5) inhibitor, could be a potential therapy. We aimed to evaluate the efficacy, safety, and tolerability of zilucoplan in adult participants with anti-HMGCR or anti-SRP autoantibody-positive immune-mediated necrotising myopathy.
METHODS:
IMNM-01 was a phase 2, multicentre, randomised, double-blind, placebo-controlled study done at 15 hospital sites across the USA, the UK, France, and the Netherlands. Participants aged 18–74 years were eligible for inclusion if they had a clinically confirmed diagnosis of immune-mediated necrotising myopathy, positive serology for anti-HMGCR or anti-SRP autoantibodies, clinical evidence of weakness, serum total creatine kinase concentration of more than 1000 U/L at screening, and no change in glucocorticoids or other immunosuppressive therapies for 30 days before baseline or expected during the first 8 weeks of the study. Participants were randomly assigned (1:1) to receive daily subcutaneous zilucoplan (0·3 mg/kg) or placebo for 8 weeks by use of a computerised randomisation algorithm; with optional enrolment in the study open-label extension. Randomisation was stratified by autoantibody status. Participants and study staff were masked to treatment group assignment. Primary efficacy endpoint (in the intent-to-treat population, defined as all participants who were randomly assigned to a treatment group) was percent change from baseline to week 8 in creatine kinase concentrations. Safety analyses were performed on the safety population (participants who received at least one dose of study drug during the main study, irrespective of whether they continued to the extension period—study participants were analysed on the basis of the treatment received). This study is registered with ClinicalTrials.gov, NCT04025632.
FINDINGS:
Between Nov 7, 2019, and Jan 7, 2021, we randomly assigned 27 participants (13 female and 14 male) to receive zilucoplan (n=12) or placebo (n=15). All 27 participants completed the 8-week main study. At week 8 there were no significant differences between treatment groups in median percent change of creatine kinase concentrations versus baseline (–15·1% [IQR –31·1 to 3·2] in the zilucoplan group vs –16·3% [–43·8 to 5·9] in the placebo group; p=0·46) and no clinically relevant improvement over time within the treatment group despite target engagement based on mode of action. There were no unexpected adverse safety or tolerability findings. Treatment-emergent adverse events were reported in nine (75%) of 12 participants in the zilucoplan group, and in 13 (87%) of 15 participants in the placebo group, and serious treatment-emergent adverse events were reported in zero participants in the zilucoplan group and three (20%) participants in the placebo group. The most frequent treatment-emergent adverse events were headache (four [33%] participants in the zilucoplan group and four [27%] participants in the placebo group) and nausea (three [25%] participants in the zilucoplan group and three [20%] participants in the placebo group).
INTERPRETATION:
C5 inhibition does not appear to be an efficacious treatment modality for people with immune-mediated necrotising myopathy. Rather than being the primary driver for disease activity, complement activation might be secondary to muscle injury.
FUNDING:
Ra Pharmaceuticals (now part of UCB Pharma)
Similar or Different? The Role of the Ventrolateral Prefrontal Cortex in Similarity Detection
Patients with frontal lobe syndrome can exhibit two types of abnormal behaviour when asked to place a banana and an orange in a single category: some patients categorize them at a concrete level (e.g., “both have peel”), while others continue to look for differences between these objects (e.g., “one is yellow, the other is orange”). These observations raise the question of whether abstraction and similarity detection are distinct processes involved in abstract categorization, and that depend on separate areas of the prefrontal cortex (PFC). We designed an original experimental paradigm for a functional magnetic resonance imaging (fMRI) study involving healthy subjects, confirming the existence of two distinct processes relying on different prefrontal areas, and thus explaining the behavioural dissociation in frontal lesion patients. We showed that: 1) Similarity detection involves the anterior ventrolateral PFC bilaterally with a right-left asymmetry: the right anterior ventrolateral PFC is only engaged in detecting physical similarities; 2) Abstraction per se activates the left dorsolateral PFC
Systematic assessment of training-induced changes in corticospinal output to hand using frameless stereotaxic transcranial magnetic stimulation.
Measuring changes in the characteristics of corticospinal output has become a critical part of assessing the impact of motor experience on cortical organization in both the intact and injured human brain. In this protocol we describe a method for systematically assessing training-induced changes in corticospinal output that integrates volumetric anatomical MRI with transcranial magnetic stimulation (TMS). A TMS coil is sited to a target grid superimposed onto a 3D MRI of cortex using a stereotaxic neuronavigation system. Subjects are then required to exercise the first dorsal interosseus (FDI) muscle on two different tasks for a total of 30 min. The protocol allows for reliably and repeatedly detecting changes in corticospinal output to FDI muscle in response to brief periods of motor training
- …