95 research outputs found

    Гибридная интегральная схема для обработки звукового сигнала

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    Разработана гибридная интегральная схема с номинальным напряжением питания 1,4 В, током потребления 0,7 мА и габаритными размерами 8x4x3 мм для обработки звукового сигнала в автономной аппаратуре.Розроблена гібридна інтегральна схема з номінальною напругою живлення 1,4 В, струмом споживання 0,7 мА і габаритними розмірами 8x4x3 мм забезпечує багатофункціональну обробку звуковою сигналу в аналоговій мікроелектронній апаратурі. Наведено її конструкторсько-технологічні та електричні параметри.Developed hybrid integrated circuit with rated supply voltage of 1,4 V, current consumption 0,7 mA and overall dimensions 8x4x3 mm provides soft processing of the audio signal in analog microelectronic equipment. Given its design, technological and electrical parameters

    Quantifying Cost-Effectiveness of Controlling Nosocomial Spread of Antibiotic-Resistant Bacteria: The Case of MRSA

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    BACKGROUND: The costs and benefits of controlling nosocomial spread of antibiotic-resistant bacteria are unknown. METHODS: We developed a mathematical algorithm to determine cost-effectiveness of infection control programs and explored the dynamical interactions between different epidemiological variables and cost-effectiveness. The algorithm includes occurrence of nosocomial infections, attributable mortality, costs and efficacy of infection control and how antibiotic-resistant bacteria affect total number of infections: do infections with antibiotic-resistant bacteria replace infections caused by susceptible bacteria (replacement scenario) or occur in addition to them (addition scenario). Methicillin-resistant Staphylococcus aureus (MRSA) bacteremia was used for illustration using observational data on S. aureus bacteremia (SAB) in our hospital (n = 189 between 2001-2004, all being methicillin-susceptible S. aureus [MSSA]). RESULTS: In the replacement scenario, the costs per life year gained range from 45,912 euros to 6590 euros for attributable mortality rates ranging from 10% to 50%. Using 20,000 euros per life year gained as a threshold, completely preventing MRSA would be cost-effective in the replacement scenario if attributable mortality of MRSA is > or = 21%. In the addition scenario, infection control would be cost saving along the entire range of estimates for attributable mortality. CONCLUSIONS: Cost-effectiveness of controlling antibiotic-resistant bacteria is highly sensitive to the interaction between infections caused by resistant and susceptible bacteria (addition or replacement) and attributable mortality. In our setting, controlling MRSA would be cost saving for the addition scenario but would not be cost-effective in the replacement scenario if attributable mortality would be < 21%

    Nasal Colonization of Humans with Methicillin-Resistant Staphylococcus aureus (MRSA) CC398 with and without Exposure to Pigs

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    Background: Studies in several European countries and in North America revealed a frequent nasal colonization of livestock with MRSA CC398 and also in humans with direct professional exposure to colonized animals. The study presented here addresses the question of further transmission to non exposed humans. Methods: After selecting 47 farms with colonized pigs in different regions of Germany we sampled the nares of 113 humans working daily with pigs and of their 116 non exposed family members. The same was performed in 18 veterinarians attending pig farms and in 44 of their non exposed family members. For investigating transmission beyond families we samples the nares of 462 pupils attending a secondary school in a high density pig farming area. MRSA were detected by direct culture on selective agar. The isolates were typed by means of spa-sequence typing and classification of SCCmec elements. For attribution of spa sequence types to clonal lineages as defined by multi locus sequence typing we used the BURP algorithm. Antibiotic susceptibility testing was performed by microbroth dilution assay. Results: At the farms investigated 86% of humans exposed and only 4.3% of their family members were found to carry MRSA exhibiting spa-types corresponding to clonal complex CC398. Nasal colonization was also found in 45% of veterinarians caring for pig farms and in 9% of their non exposed family members. Multivariate analysis revealed that antibiotic usage prior to sampling beard no risk with respect to colonization. From 462 pupils only 3 were found colonized, all 3 were living on pig farms. Conclusion: These results indicate that so far the dissemination of MRSA CC398 to non exposed humans is infrequent and probably does not reach beyond familial communities

    Prevalence and molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) among pigs on German farms and import of livestock-related MRSA into hospitals

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    The aim of this study was to evaluate the prevalence and molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) among pigs and estimate the impact of this animal reservoir on human healthcare. Nasal swabs were derived from 1,600 pigs at 40 German farms. The MRSA were characterized using S. aureus protein A (spa) typing, multilocus sequence typing (MLST) and detection of toxin genes. In a retrospective case control study, we compared risk factors for the carriage of MRSA between patients carrying spa types found among regional pigs and patients with other MRSA molecular types. Pigs carrying MRSA were identified on 70% of the farms (spa types t011, t034, t108, t1451 and t2510, all associated with MLST sequence type ST398). Contact to pigs and cattle were independent risk factors for the carriage of these spa types in patients at hospital admission. Our results indicate that livestock represents a relevant reservoir for the import of MRSA into regional German hospitals

    MicroRNA-34a activation in tuberous sclerosis complex during early brain development may lead to impaired corticogenesis

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    AIMS: Tuberous sclerosis complex (TSC) is a genetic disorder associated with dysregulation of the mechanistic target of rapamycin complex 1 (mTORC1) signalling pathway. Neurodevelopmental disorders, frequently present in TSC, are linked to cortical tubers in the brain. We previously reported microRNA-34a (miR-34a) among the most upregulated miRs in tubers. Here, we characterised miR-34a expression in tubers with the focus on the early brain development and assessed the regulation of mTORC1 pathway and corticogenesis by miR-34a. METHODS: We analysed the expression of miR-34a in resected cortical tubers (n = 37) compared with autopsy-derived control tissue (n = 27). The effect of miR-34a overexpression on corticogenesis was assessed in mice at E18. The regulation of the mTORC1 pathway and the expression of the bioinformatically predicted target genes were assessed in primary astrocyte cultures from three patients with TSC and in SH-SY5Y cells following miR-34a transfection. RESULTS: The peak of miR-34a overexpression in tubers was observed during infancy, concomitant with the presence of pathological markers, particularly in giant cells and dysmorphic neurons. miR-34a was also strongly expressed in foetal TSC cortex. Overexpression of miR-34a in mouse embryos decreased the percentage of cells migrated to the cortical plate. The transfection of miR-34a mimic in TSC astrocytes negatively regulated mTORC1 and decreased the expression of the target genes RAS related (RRAS) and NOTCH1. CONCLUSIONS: MicroRNA-34a is most highly overexpressed in tubers during foetal and early postnatal brain development. miR-34a can negatively regulate mTORC1; however, it may also contribute to abnormal corticogenesis in TSC

    Identification of Srp9 as a febrile seizure susceptibility gene

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    Objective: Febrile seizures (FS) are the most common seizure type in young children. Complex FS are a risk factor for mesial temporal lobe epilepsy (mTLE). To identify new FS susceptibility genes we used a forward genetic strategy in mice and subsequently analyzed candidate genes in humans. Methods: We mapped a quantitative trait locus (QTL1) for hyperthermia-induced FS on mouse chromosome 1, containing the signal recognition particle 9 (Srp9) gene. Effects of differential Srp9 expression were assessed in vivo and in vitro. Hippocampal SRP9 expression and genetic association were analyzed in FS and mTLE patients. Results: Srp9 was differentially expressed between parental strains C57BL/6J and A/J. Chromosome substitution strain 1 (CSS1) mice exhibited lower FS susceptibility and Srp9 expression than C57BL/6J mice. In vivo knockdown of brain Srp9 reduced FS susceptibility. Mice with reduced Srp9 expression and FS susceptibility, exhibited reduced hippocampal AMPA and NMDA currents. Downregulation of neuronal Srp9 reduced surface expression of AMPA receptor subunit GluA1. mTLE patients with antecedent FS had higher SRP9 expression than patients without. SRP9 promoter SNP rs12403575(G/A) was genetically associated with FS and mTLE. Interpretation: Our findings identify SRP9 as a novel FS susceptibility gene and indicate that SRP9 conveys its effects through endoplasmic reticulum (ER)-dependent synthesis and trafficking of membrane proteins, such as glutamate receptors. Discovery of this new FS gene and mechanism may provide new leads for early diagnosis and treatment of children with complex FS at risk for mTLE
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