276 research outputs found
Test engineering education in Europe: the EuNICE-Test project
The paper deals with a European experience of education in industrial test of ICs and SoCs using remote testing facilities. The project addresses the problem of the shortage in microelectronics engineers aware with the new challenge of testing mixed-signal SoCs far multimedia/telecom market. It aims at providing test training facilities at a European scale in both initial and continuing education contexts. This is done by allowing the academic and industrial partners of the consortium to train engineers using the common test resources center (CRTC) hosted by LIRMM (Laboratoire d'Informatique, de Robotique et de Microelectronique de Montpellier, France). CRTC test tools include up-to-date/high-tech testers that are fully representative of real industrial testers as used on production testfloors. At the end of the project, it is aimed at reaching a cruising speed of about 16 trainees per year per center. Each trainee will have attend at least one one-week training using the remote test facilities of CRTC
Structure-affinity relationships (SARs) and structure-kinetics relationships (SKRs) of Kv11.1 blockers
Medicinal Chemistr
High-rate pacing suppresses Torsade de Pointes arrhythmias and reduces spatial dispersion of repolarization in the chronic AV-block dog model
Background: An electrical storm of Torsade de Pointes arrhythmias (TdP) can be reproducibly induced in the anesthetized chronic AV-block (CAVB) dog by infusion of the IKr-blocker dofetilide. Earlier studies showed that these arrhythmias 1) arise from locations with high spatial dispersion in repolarization (SDR) and 2) can be suppressed by high-rate pacing. We examined whether suppression of TdP by high-rate pacing is established through a decrease in SDR in the CAVB dog.Methods: Dofetilide (25 μg/kg in 5 min) was administered to 5 anesthetized CAVB dogs to induce TdP arrhythmias. During the experiments, animals were continuously paced from the right ventricular apex at 50 beats/minute (RVA50). Upon TdP occurrence and conversion, RVA pacing was consecutively set to 100, 80 and 60 beats/minute for 2 min, referred to as pacing blocks. To determine the additional anti-arrhythmic effects of HRP over defibrillation alone, the number of arrhythmic events and SDR at RVA100 were compared to data from three previously conducted experiments, in which dogs underwent the same experimental protocol but were paced at RVA60 upon TdP occurrence (RVA60retro). In all experiments, recordings included surface electrocardiogram and mapping by 56 intramural needles, each recording four electrograms, evenly inserted into the ventricular walls and septum. For each pacing block, the number of ectopic beats (EB), and TdP severity were scored. SDR was quantified as the average difference in repolarization time within four squared needles (SDRcubic).Results: In 4 out of 5 animals, pacing at RVA100 suppressed TdP occurrence. One dog could not be converted by defibrillation after the initial TdP. Compared to RVA50, pacing at RVA100, but not RVA80 and RVA60, significantly reduced the TdP score (78 ± 33 vs. 0 ± 0, p < 0.05 and vs. 12.5 ± 25 and 25 ± 50, both p > 0.05). The reduction in TdP score was reflected by a significant decrease in SDRcubic (125 ± 46 ms before TdP vs. 49 ± 18 ms during RVA100, p < 0.05), and SDR was smaller than in the RVA60retro animals (101 ± 52 ms, p < 0.05 vs. RVA100).Conclusion: In CAVB dogs, high-rate pacing effectively suppresses TdP, which, at least in part, results from a spatial homogenization of cardiac repolarization, as reflected by a decrease in SDR
CE-MS metabolic profiling of volume-restricted plasma samples from an acute mouse model for epileptic seizures to discover potentially involved metabolomic features
Currently, a high variety of analytical techniques to perform metabolomics is available. One of these techniques is capillary electrophoresis coupled to mass spectrometry (CE-MS), which has emerged as a rather strong analytical technique for profiling polar and charged compounds. This work aims to discover with CE-MS potential metabolic consequences of evoked seizures in plasma by using a 6Hz acute corneal seizure mouse model. CE-MS is an appealing technique because of its capability to handle very small sample volumes, such as the 10 mu L plasma samples obtained using capillary microsampling in this study. After liquid-liquid extraction, the samples were analyzed with CE-MS using low-pH separation conditions, followed by data analysis and biomarker identification. Both electrically induced seizures showed decreased values of methionine, lysine, glycine, phenylalanine, citrulline, 3-methyladenine and histidine in mice plasma. However, a second provoked seizure, 13 days later, showed a less pronounced decrease of the mean concentrations of these plasma metabolites, demonstrated by higher fold change ratios. Other obtained markers that can be related to seizure activities based on literature data, are isoleucine, serine, proline, tryptophan, alanine, arginine, valine and asparagine. Most amino acids showed relatively stable plasma concentrations between the basal levels (Time point 1) and after the 13-day wash-out period (Time point 3), which suggests its effectiveness. Overall, this work clearly demonstrated the possibility of profiling metabolite consequences related to seizure activities of an intrinsically low amount of body fluid using CE-MS. It would be useful to investigate and validate, in the future, the known and unknown metabolites in different animal models as well as in humans.Analytical BioScience
Fast Nonlinear Ion Transport via Field-Induced Hydrodynamic Slip in Sub-20-nm Hydrophilic Nanofluidic Transistors
Social Determinants of Community Health Services Utilization among the Users in China: A 4-Year Cross-Sectional Study
Background To identify social factors determining the frequency of community health service (CHS) utilization among CHS users in China. Methods Nationwide cross-sectional surveys were conducted in 2008, 2009, 2010, and 2011. A total of 86,116 CHS visitors selected from 35 cities were interviewed. Descriptive analysis and multinomial logistic regression analysis were employed to analyze characteristics of CHS users, frequency of CHS utilization, and the socio-demographic and socio-economic factors influencing frequency of CHS utilization. Results Female and senior CHS clients were more likely to make 3–5 and ≥6 CHS visits (as opposed to 1–2 visits) than male and young clients, respectively. CHS clients with higher education were less frequent users than individuals with primary education or less in 2008 and 2009; in later surveys, CHS clients with higher education were the more frequent users. The association between frequent CHS visits and family income has changed significantly between 2008 and 2011. In 2011, income status did not have a discernible effect on the likelihood of making ≥6 CHS visits, and it only had a slight effect on making 3–5 CHS visits. Conclusion CHS may play an important role in providing primary health care to meet the demands of vulnerable populations in China. Over time, individuals with higher education are increasingly likely to make frequent CHS visits than individuals with primary school education or below. The gap in frequency of CHS utilization among different economic income groups decreased from 2008 to 2011
LUF7244 plus Dofetilide Rescues Aberrant Kv11.1 Trafficking and Produces Functional IKv11.1
Kv11.1 (hERG) channels play a critical role in repolarization of cardiomyocytes during the cardiac action potential (AP). Drug mediated Kv11.1 blockade results in AP prolongation, which poses an increased risk of sudden cardiac death. Many drugs, like pentamidine, interfere with normal Kv11.1 forward trafficking and thus reduce functional Kv11.1 channel densities. Although class III antiarrhythmics, e.g. dofetilide, rescue congenital and acquired forward trafficking defects, this is of little use due to their simultaneous acute channel blocking effect. We aimed to test the ability of a combination of dofetilide plus LUF7244, a Kv11.1 allosteric modulator/activator, to rescue Kv11.1 trafficking and produce functional Kv11.1 current. LUF7244 treatment by itself did not disturb or rescue WT or G601S Kv11.1 trafficking as shown by western blot and immunofluorescence microcopy analysis. Pentamidine-decreased maturation of WT Kv11.1 levels was rescued by 10 μM dofetilide or 10 μM dofetilide + 5 μM LUF7244. In trafficking defective G601S Kv11.1 cells, dofetilide (10 μM) or dofetilide+LUF7244 (10+5 μM) restored Kv11.1 trafficking also, as demonstrated by western blot and immunofluorescence microscopy. LUF7244 (10 μM) increased IKv11.1 despite the presence of dofetilide (1 μM) in WT Kv11.1 cells. In G601S expressing cells, long-term treatment (24-48 h) with LUF7244 (10 μM) and dofetilide (1 μM) increased IKv11.1 compared to non-treated, or acutely treated cells. We conclude that dofetilide plus LUF7244 rescues Kv11.1 trafficking and produces functional IKv11.1. Thus, combined administration of LUF7244 and an IKV11.1 trafficking corrector could serve as a new pharmacological therapy of both congenital and drug-induced Kv11.1 trafficking defects.Toxicolog
Multi-frequency study of supernova remnants in the Large Magellanic Cloud. Confirmation of the supernova remnant status of DEM L205
We present new X-ray and radio data of the LMC SNR candidate DEM L205,
obtained by XMM-Newton and ATCA, along with archival optical and infrared
observations. We use data at various wavelengths to study this object and its
complex neighbourhood, in particular in the context of the star formation
activity, past and present, around the source. We analyse the X-ray spectrum to
derive some remnant's properties, such as age and explosion energy. Supernova
remnant features are detected at all observed wavelengths: soft and extended
X-ray emission is observed, arising from a thermal plasma with a temperature kT
between 0.2 keV and 0.3 keV. Optical line emission is characterised by an
enhanced [SII]/Halpha ratio and a shell-like morphology, correlating with the
X-ray emission. The source is not or only tentatively detected at near-infrared
wavelengths (< 10 microns), but there is a detection of arc-like emission at
mid and far-infrared wavelengths (24 and 70 micron) that can be unambiguously
associated with the remnant. We suggest that thermal emission from dust heated
by stellar radiation and shock waves is the main contributor to the infrared
emission. Finally, an extended and faint non-thermal radio emission correlates
with the remnant at other wavelengths and we find a radio spectral index
between -0.7 and -0.9, within the range for SNRs. The size of the remnant is
~79x64 pc and we estimate a dynamical age of about 35000 years. We definitely
confirm DEM L205 as a new SNR. This object ranks amongst the largest remnants
known in the LMC. The numerous massive stars and the recent outburst in star
formation around the source strongly suggest that a core-collapse supernova is
the progenitor of this remnant. (abridged)Comment: 11 pages, 6 figures, accepted for publication in A&
Assessment of health care needs and utilization in a mixed public-private system: the case of the Athens area
BACKGROUND: Given the public-private mix of the Greek health system, the purpose of this study was to assess whether variations in the utilisation of health services, both primary and inpatient care, were associated with underlying health care needs and/or various socio-economic factors. METHODS: Data was obtained from a representative sample (N = 1426) residing in the broader Athens area (response rate 70.6%). Perceived health-related quality of life (HRQOL), as measured by the physical and mental summary component scores of the SF-36 Health Survey, was used as a proxy of health care need. Health care utilization was measured by a) last-month visits to public sector physicians, b) last-month visits to private sector physicians, c) last-year visits to hospital emergency departments and d) last-year hospital admissions. Statistical analysis involved the implementation of logistic regression models. RESULTS: Health care need was the factor most strongly associated with all measures of health care utilization, except for visits to public physicians. Women, elderly, less wealthy and individuals of lower physical health status visited physicians contracted to their insurance fund (public sector). Women, well educated and those once again of lower physical health status were more likely to visit private providers. Visits to hospital emergency departments and hospital admissions were related to need and no socio-economic factor was related to the use of those types of care. CONCLUSION: This study has demonstrated a positive relationship between health care need and utilisation of health services within a mixed public-private health care system. Concurrently, interesting differences are evident in the utilization of various types of services. The results have potential implications in health policy-making and particularly in the proper allocation of scarce health resources
Molecular and Electrophysiological Characterization of a Novel Cation Channel of Trypanosoma cruzi
We report the identification, functional expression, purification, reconstitution and electrophysiological characterization of a novel cation channel (TcCat) from Trypanosoma cruzi, the etiologic agent of Chagas disease. This channel is potassium permeable and shows inward rectification in the presence of magnesium. Western blot analyses with specific antibodies indicated that the protein is expressed in the three main life cycle stages of the parasite. Surprisingly, the parasites have the unprecedented ability to rapidly change the localization of the channel when they are exposed to different environmental stresses. TcCat rapidly translocates to the tip of the flagellum when trypomastigotes are submitted to acidic pH, to the plasma membrane when epimastigotes are submitted to hyperosmotic stress, and to the cell surface when amastigotes are released to the extracellular medium. Pharmacological block of TcCat activity also resulted in alterations in the trypomastigotes ability to respond to hyperosmotic stress. We also demonstrate the feasibility of purifying and reconstituting a functional ion channel from T. cruzi after recombinant expression in bacteria. The peculiar characteristics of TcCat could be important for the development of specific inhibitors with therapeutic potential against trypanosomes
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