Ventricular Volume Load Reveals the Mechanoelastic Impact of Communicating Hydrocephalus on Dynamic Cerebral Autoregulation.

Several studies have shown that the progression of communicating hydrocephalus is associated with diminished cerebral perfusion and microangiopathy. If communicating hydrocephalus similarly alters the cerebrospinal fluid circulation and cerebral blood flow, both may be related to intracranial mechanoelastic properties as, for instance, the volume pressure compliance. Twenty-three shunted patients with communicating hydrocephalus underwent intraventricular constant-flow infusion with Hartmann's solution. The monitoring included transcranial Doppler (TCD) flow velocities (FV) in the middle (MCA) and posterior cerebral arteries (PCA), intracranial pressure (ICP), and systemic arterial blood pressure (ABP). The analysis covered cerebral perfusion pressure (CPP), the index of pressure-volume compensatory reserve (RAP), and phase shift angles between Mayer waves (3 to 9 cpm) in ABP and MCA-FV or PCA-FV. Due to intraventricular infusion, the pressure-volume reserve was exhausted (RAP) 0.84+/-0.1 and ICP was increased from baseline 11.5+/-5.6 to plateau levels of 20.7+/-6.4 mmHg. The ratio dRAP/dICP distinguished patients with large 0.1+/-0.01, medium 0.05+/-0.02, and small 0.02+/-0.01 intracranial volume compliances. Both M wave phase shift angles (r = 0.64; p<0.01) and CPP (r = 0.36; p<0.05) displayed a gradual decline with decreasing dRAP/dICP gradients. This study showed that in communicating hydrocephalus, CPP and dynamic cerebral autoregulation in particular, depend on the volume-pressure compliance. The results suggested that the alteration of mechanoelastic characteristics contributes to a reduced cerebral perfusion and a loss of autonomy of cerebral blood flow regulation. Results warrant a prospective TCD follow-up to verify whether the alteration of dynamic cerebral autoregulation may indicate a progression of communicating hydrocephalus.Alexander-von-Humboldt foundation, Cambridge Enterprise Ltd.This is the final version of the article. It first appeared from the Public Library of Science via http://dx.doi.org/10.1371/journal.pone.015850

Survey in expert clinicians on the validity of automated calculation of optimal cerebral perfusion pressure

BACKGROUND: Optimal cerebral perfusion pressure (CPPopt) targeting in traumatic brain injury (TBI) patients constitutes an active and controversial area of research. It has been suggested that an autoregulation guided CPP therapy may improve TBI outcome. Prerequisites of a CPPopt intervention study would be objective criteria for the CPPopt detection. This study compared the agreement between automated and visual CPPopt detection. METHODS: Twenty-five clinicians from 18 centers worldwide, familiar with brain monitoring and using dedicated software, reviewed ten 4-hour CPPopt screenshots at 48 hours after ictus in selected TBI patients. Each screenshot displayed the trends of cerebral perfusion pressure (CPP), intracranial pressure (ICP), cerebrovascular pressure reactivity (PRx) as well as the "CPP-optimal" curve and its associated value (automated CPPopt). The main objective was to evaluate the agreement between expert clinicians as well as the agreement between the clinicians and automated CPPopt. RESULTS : Twenty-two clinicians responded to our call (88%). Three screenshots were judged as "CPPopt not determinable" by > 45% of the clinicians. For the whole group, the consensus between automated CPPopt and clinicians' visual CPPopt was high. Three clinicians were identified as outliers. All clinicians recommended to modify CPP when patients differed >+/- 5 mmHg from their CPPopt. The inter-observer consensus was highest in cases with current CPP below the optimal value. CONCLUSIONS: The overall agreement between automated CPPopt and visual CPPopt identified by autoregulation experts was high, except for those cases when the curve was deemed by the clinicians not reliable enough to yield a trustworthy CPPopt

Exactly solvable Richardson–Gaudin models and their applications

3 pages, 1 table, 1 figure.--PACS nrs.: 21.60.Cs, 21.60.Fw, 02.30.Ik.--Arxiv pre-print available at: http://arxiv.org/abs/math-ph/0609022v1We first show that the quantum pairing problem can be mapped exactly on to a classical electrostatic problem in two dimensions and then use this analogy to obtain a pictorial representation of how superconductivity arises in a finite fermionic system. Specific application to the nuclei 114−116Sn suggests some new insight into the evolution of pairing correlations in a quantum system with few active particles. We also summarize other recent work on exactly solvable pairing models, including their applications in a wide variety of strongly correlated quantum systems.The work reported herein was supported in part by the US National Science Foundation under grant no PHY-0140036 and in part by the Spanish DGI under grant no BFM2003-05316-C02-02.Peer reviewe

Мобильное приложение для курьерской службы доставки «Ptichka»

Целью работы является реализация кроссплатформенного мобильного приложения для курьерской службы доставки "Ptichka". В процессе выполнения выпускной квалификационной работы проводился сравнительный анализ технологий разработки мобильных приложении?, с целью выбора наиболее подходящей для решения целей данной работы.The aim of the work is implementation a cross-platform mobile application for courier delivery service "Ptichka"

Baroreflex Impairment After Subarachnoid Hemorrhage Is Associated With Unfavorable Outcome.

BACKGROUND AND PURPOSE: Aneurysmal subarachnoid hemorrhage (SAH) is characterized by important changes in the autonomic nervous system with potentially adverse consequences. The baroreflex has a key role in regulating the autonomic nervous system. Its role in SAH outcome is not known. The purpose of this study was to evaluate the association between the baroreflex and the functional 3-month outcome in SAH. METHODS: The study used a prospective database of 101 patients hospitalized for SAH. We excluded patients receiving β-blockers or noradrenaline. Baroreflex sensitivity (BRS) was measured using the cross-correlation method. A good outcome was defined by a Glasgow Outcome Scale score at 4 or 5 at 3 months. RESULTS: Forty-eight patients were included. Median age was 58 years old (36-76 years); women/men: 34/14. The World Federation of Neurosurgery clinical severity score on admission was 1 or 2 for 73% of patients. In the univariate analysis, BRS (P=0.007), sedation (P=0.001), World Federation of Neurosurgery score (P=0.001), Glasgow score (P=0.002), Fisher score (P=0.022), and heart rate (P=0.037) were associated with outcome. The area under the receiver operating characteristic curve for the model with BRS as a single predictor was estimated at 0.835. For each unit increase in BRS, the odds for a good outcome were predicted to increase by 31%. Area under the receiver operating characteristic curve for heart rate alone was 0.670. In the multivariate analysis, BRS (odds ratio, 1.312; 95% confidence interval, 1.048-1.818; P=0.018) and World Federation of Neurosurgery (odds ratio, 0.382; 95% confidence interval, 0.171-0.706; P=0.001) were significantly associated with outcome. Area under the receiver operating characteristic curve was estimated at 0.900. CONCLUSIONS: In SAH, early BRS was associated with 3-month outcome. This conclusion requires confirmation on a larger number of patients in a multicentre study

Разработка системы управления теплопотреблением административного здания

В выпускной квалификационной работе рассматривается система управления теплопотреблением административного здания в г. Томске по адресу ул. Предвокзальная 49/3. Согласно федеральному закону №263-ФЗ о энергосбережением, был создан проект по внедрению системы диспетчерезации и автоматизации теплового узла. При разработке проекта был произведен выбор оборудования и рассчитаны гидравлические потери, социальная ответственность и экономический эффект внедрения данной системы.Final qualifying work contains a review of a system that manages the heat consumption in the administrative building in Tomsk, Predvokzalnaya street 49/3. According to the federal law #263 about energy-saving, one of the projects was developed to implement a dispatch and automation system for the heat node. During the development of the project the equipment was selected, the hydraulic losses were calculated same as the social responsibility and economic effect of the introduction of this system