78 research outputs found

    Модернизация технологического процесса сбора и утилизации газа на установках подготовки нефти на месторождениях Западной Сибири

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    Объектом исследования является технологический процесс подготовки скважинной продукции и осушки газа на установке подготовки нефти (УПН) п. Пионерный Катыльгинского нефтяного месторождения компании АО "Томскнефть" ВНК, а также технология компримирования газа на дожимной контейнерной компрессорной станции (ДККС). Целью данной работы является компримирование попутного нефтяного газа добытого на второй ступени сепарации на объекте УПН "Пионерный" и доказательство эффективности использования ДККС. В процессе исследования проведен анализ эффективности работы дожимной контейнерной компрессорной станции. В результате исследования была доказана эффективность внедрения ДККС в технологический процесс объекта УПН "Пионерный", путем снижения количества вредных выбросов в атмосферу.The object of the study is the technological process of well production preparation and gas dehydration at the oil treatment unit (OTP) of the Pionerny settlement of the Katylginsky oil field of the JSC Tomskneft VNK, as well as the technology of gas compression at the booster container compressor station (DCKS). The purpose of this work is to compress associated petroleum gas produced at the second stage of separation at the Pioneer OTF facility and to prove the efficiency of using the DCS. In the course of the study, the analysis of the efficiency of the booster container compressor station was carried out

    Reversible cerebral vasoconstriction syndrome with concurrent bilateral carotid artery dissection

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    Background: The pathophysiological basis of reversible cerebral vasoconstriction syndrome is poorly understood but carotid artery dissection has been discussed as a rare possible cause. So far, only single cases of unilateral carotid artery dissection and reversible cerebral vasoconstriction syndrome have been reported. Case: Here, we describe the case of a 54-year old patient presenting to the emergency department with right hemiparesis, hypaesthesia and dysarthria. Furthermore, he reported two episodes of thunderclap headache after autosexual activity. Cerebral imaging showed ischaemic infarcts, slight cortical subarachnoid haemorrhage, bilateral carotid artery dissection and fluctuating intracranial vessel irregularities, compatible with reversible cerebral vasoconstriction syndrome. An extensive diagnostic work-up was normal. No typical trigger factors of reversible cerebral vasoconstriction syndrome could be found. The patient received intravenous heparin and the calcium channel blocker nimodipine. Follow-up imaging revealed no vessel irregularities, the left internal carotid artery was still occluded. Conclusion: This case supports the assumption that carotid artery dissection should be considered as a potential trigger of reversible cerebral vasoconstriction syndrome, possibly by altering sympathetic vascular tone

    Endovascular stroke treatment in orally anticoagulated patients: an analysis from the German Stroke Registry-Endovascular Treatment

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    Background Endovascular treatment (ET) in orally anticoagulated (OAC) patients has not been evaluated in randomized clinical trials and data regarding this issue are sparse. Methods We analyzed data from the German Stroke Registry-Endovascular Treatment (GSR-ET; NCT03356392, date of registration: 22 Nov 2017). The primary outcomes were successful reperfusion defined as modified thrombolysis in cerebral infarction (mTICI 2b-3), good outcome at 3 months (modified Rankin scale [mRS] 0–2 or back to baseline), and intracranial hemorrhage (ICH) on follow-up imaging at 24 h analyzed by unadjusted univariate and adjusted binary logistic regression analysis. Additionally, we analyzed mortality at 3 months with adjusted binary logistic regression analysis. Results Out of 6173 patients, there were 1306 (21.2%) OAC patients, 479 (7.8%) with vitamin K antagonists (VKA) and 827 (13.4%) with non-vitamin K antagonist oral anticoagulation (NOAC). The control group consisted of 4867 (78.8%) non-OAC patients. ET efficacy with the rates of mTICI 2b-3 was similar among the three groups (85.6%, 85.3% vs 84.3%, p = 0.93 and 1). On day 90, good outcome was less frequent in OAC patients (27.8%, 27.9% vs 39.5%, p < 0.005 and < 0.005). OAC status was not associated with ICH at 24 h (NOAC: odd’s ratio [OR] 0.89, 95% confidence interval [CI] 0.67–1.20; VKA: OR 1.04, CI 0.75–1.46). Binary logistic regression analysis revealed no influence of OAC status on good outcome at 3 months (NOAC: OR 1.25, CI 0.99–1.59; VKA: OR 1.18, CI 0.89–1.56) and mortality at 3 months (NOAC: OR 1.03, CI 0.81–1.30; VKA: OR 1.04, CI 0.78–1.1.37). Conclusions ET can be performed safely and successfully in LVO stroke patients treated with OAC. Clinical trial registration-URL http://www.clinicaltrials.gov. Unique identifier: NCT03356392

    Nanolithography Based on the Formation and Manipulation of Nanometer-Size Organic Liquid Menisci

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    In this work we form and manipulate nanometer-size liquid bridges of nonpolar organic solvents such as octane and 1-octene with a dynamic force microscope. These menisci have been used to confine chemical reactions that gave rise to the fabrication of nanometer-size structures.Peer reviewe

    Decreased CSF Levels of beta-Amyloid in Patients With Cortical Superficial Siderosis

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    Background: Cortical superficial siderosis (cSS) represents a key neuroimaging marker of cerebral amyloid angiopathy (CAA) that is associated with intracranial hemorrhages and cognitive impairment. Nevertheless, the association between cSS and core cerebrospinal fluid (CSF) biomarkers for dementia remain unclear. Methods: One hundred and one patients with probable (79%, 80/101) or possible (21%, 21/101) CAA according to the modified Boston criteria and mild cognitive impairment according to Petersen criteria were prospectively included between 2011 and 2016. CSF analyses of ß-amyloid 42, ß-amyloid 40, total tau and phosphorylated tau were performed using sandwich-type enzyme-linked immunosorbent-assay. All patients received MRI and Mini-Mental-State Examination (MMSE). Logistic regression analysis was used to adjust for possible confounders. Results: cSS was present in 61% (62/101). Of those, 53% (33/62) had disseminated cSS and 47% (29/62) focal cSS. ß-amyloid 42 was lower in patients with cSS than in patients without cSS (OR 0.2; 95% CI 0.08–0.6; p = 0.0052) and lower in patients with disseminated cSS than in those with focal cSS (OR 0.02; 95% CI 0.003–0.2; p = 0.00057). Presence of cSS had no association with regard to ß-amyloid 40, total tau and phosphorylated tau. Conclusions: Our results demonstrate that the presence and extent of cSS are associated with reduced CSF ß-amyloid 42 levels. Further studies are needed to investigate the underlying mechanisms of this association

    The carotid plaque imaging in acute stroke (CAPIAS) study:

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    Background: In up to 30% of patients with ischemic stroke no definite etiology can be established. A significant proportion of cryptogenic stroke cases may be due to non-stenosing atherosclerotic plaques or low grade carotid artery stenosis not fulfilling common criteria for atherothrombotic stroke. The aim of the CAPIAS study is to determine the frequency, characteristics, clinical and radiological long-term consequences of ipsilateral complicated American Heart Association lesion type VI (AHA-LT VI) carotid artery plaques in patients with cryptogenic stroke. Methods/Design: 300 patients (age > 49 years) with unilateral DWI-positive lesions in the anterior circulation and non- or moderately stenosing (<70% NASCET) internal carotid artery plaques will be enrolled in the prospective multicenter study CAPIAS. Carotid plaque characteristics will be determined by high-resolution black-blood carotid MRI at baseline and 12 month follow up. Primary outcome is the prevalence of complicated AHA-LT VI plaques in cryptogenic stroke patients ipsilateral to the ischemic stroke compared to the contralateral side and to patients with defined stroke etiology. Secondary outcomes include the association of AHA-LT VI plaques with the recurrence rates of ischemic events up to 36 months, rates of new ischemic lesions on cerebral MRI (including clinically silent lesions) after 12 months and the influence of specific AHA-LT VI plaque features on the progression of atherosclerotic disease burden, on specific infarct patterns, biomarkers and aortic arch plaques. Discussion: CAPIAS will provide important insights into the role of non-stenosing carotid artery plaques in cryptogenic stroke. The results might have implications for our understanding of stroke mechanism, offer new diagnostic options and provide the basis for the planning of targeted interventional studies

    Catch-up-ESUS - follow-up in embolic stroke of undetermined source (ESUS) in a prospective, open-label, observational study: study protocol and initial baseline data

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    Introduction. So far there is no uniform, commonly accepted diagnostic and therapeutic algorithm for patients with embolic stroke of undetermined source (ESUS). Recent clinical trials on secondary stroke prevention in ESUS did not support the use of oral anticoagulation. As ESUS comprises heterogeneous subgroups including a wide age-range, concomitant patent foramen ovale (PFO), and variable probability for atrial fibrillation (AF), an individualised approach is urgently needed. This prospective registry study aims to provide initial data towards an individual, structured diagnostic and therapeutic approach in ESUS patients. Methods and analysis. The open-label, investigator-initiated, prospective, single-centre, observational registry study (Catch-up-ESUS) started in 01/2018. Consecutive ESUS patients ≥18 years who give informed consent are included and will be followed up for 3 years. Stratified by age <60 or ≥60 years, the patients are processed following a standardised diagnostic and treatment algorithm with an interdisciplinary design involving neurologists and cardiologists. Depending on the strata, patients receive a transesophageal echocardiogram; all patients receive an implantable cardiac monitor. Patients <60 years with PFO and without evidence of concomitant AF are planned for PFO closure within 6 months after stroke. The current diagnostic and therapeutic workup of ESUS patients requires improvement by both standardisation and a more individualised approach. Catch-up-ESUS will provide important data with respect to AF detection and PFO closure and will estimate stratified stroke recurrence rates after ESUS. Ethics and dissemination. The study has been approved by the responsible ethics committee at the Ludwig Maximilian University, Munich, Germany (project number 17–685). Catch-Up-ESUS is conducted in accordance with the Declaration of Helsinki. All patients will have to give written informed consent or, if unable to give consent themselves, their legal guardian will have to provide written informed consent for their participation. The first observation period of the registry study is 1 year, followed by the first publication of the results including follow-up of the patients. Further publications will be considered according the predefined individual follow-up dates of the stroke patients up to 36 months

    Structural reorganization of the cerebral cortex after vestibulo-cerebellar stroke

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    Objective: Structural reorganization following cerebellar infarcts is not yet known. This study aimed to demonstrate structural volumetric changes over time in the cortical vestibular and multisensory areas (i.e., brain plasticity) after acute cerebellar infarcts with vestibular and ocular motor symptoms. Additionally, we evaluated whether structural reorganization in the patients topographically correlates with cerebello-cortical connectivity that can be observed in healthy participants. Methods: We obtained high-resolution structural imaging in seven patients with midline cerebellar infarcts at two time points. These data were compared to structural imaging of a group of healthy age-matched controls using voxel-based morphometry (2×2 ANOVA approach). The maximum overlap of the infarcts was used as a seed region for a separate resting-state functional connectivity analysis in healthy volunteers. Results: Volumetric changes were detected in the multisensory cortical vestibular areas around the parieto-opercular and (retro-) insular cortex. Furthermore, structural reorganization was evident in parts of the frontal, temporal, parietal, limbic, and occipital lobes and reflected functional connections between the main infarct regions in the cerebellum and the cerebral cortex in healthy individuals. Conclusions: This study demonstrates structural reorganization in the parieto-opercular insular vestibular cortex after acute vestibulo-cerebellar infarcts. Additionally, the widely distributed structural reorganization after midline cerebellar infarcts provides additional in vivo evidence for the multifaceted contribution of cerebellar processing to cortical functions that extend beyond vestibular or ocular motor function

    Global multisensory reorganization after vestibular brain stem stroke

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    Objective Patients with acute central vestibular syndrome suffer from vertigo, spontaneous nystagmus, postural instability with lateral falls, and tilts of visual vertical. Usually, these symptoms compensate within months. The mechanisms of compensation in vestibular infarcts are yet unclear. This study focused on structural changes in gray and white matter volume that accompany clinical compensation. Methods We studied patients with acute unilateral brain stem infarcts prospectively over 6 months. Structural changes were compared between the acute phase and follow‐up with a group of healthy controls using voxel‐based morphometry. Results Restitution of vestibular function following brain stem infarcts was accompanied by downstream structural changes in multisensory cortical areas. The changes depended on the location of the infarct along the vestibular pathways in patients with pathological tilts of the SVV and on the quality of the vestibular percept (rotatory vs graviceptive) in patients with pontomedullary infarcts. Patients with pontomedullary infarcts with vertigo or spontaneous nystagmus showed volumetric increases in vestibular parietal opercular multisensory and (retro‐) insular areas with right‐sided preference. Compensation of graviceptive deficits was accompanied by adaptive changes in multiple multisensory vestibular areas in both hemispheres in lower brain stem infarcts and by additional changes in the motor system in upper brain stem infarcts. Interpretation This study demonstrates multisensory neuroplasticity in both hemispheres along with the clinical compensation of vestibular deficits following unilateral brain stem infarcts. The data further solidify the concept of a right‐hemispheric specialization for core vestibular processing. The identification of cortical structures involved in central compensation could serve as a platform to launch novel rehabilitative treatments such as transcranial stimulations
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