171 research outputs found
Diffuse-Charge Dynamics in Electrochemical Systems
The response of a model micro-electrochemical system to a time-dependent
applied voltage is analyzed. The article begins with a fresh historical review
including electrochemistry, colloidal science, and microfluidics. The model
problem consists of a symmetric binary electrolyte between parallel-plate,
blocking electrodes which suddenly apply a voltage. Compact Stern layers on the
electrodes are also taken into account. The Nernst-Planck-Poisson equations are
first linearized and solved by Laplace transforms for small voltages, and
numerical solutions are obtained for large voltages. The ``weakly nonlinear''
limit of thin double layers is then analyzed by matched asymptotic expansions
in the small parameter , where is the
screening length and the electrode separation. At leading order, the system
initially behaves like an RC circuit with a response time of
(not ), where is the ionic diffusivity, but nonlinearity
violates this common picture and introduce multiple time scales. The charging
process slows down, and neutral-salt adsorption by the diffuse part of the
double layer couples to bulk diffusion at the time scale, . In the
``strongly nonlinear'' regime (controlled by a dimensionless parameter
resembling the Dukhin number), this effect produces bulk concentration
gradients, and, at very large voltages, transient space charge. The article
concludes with an overview of more general situations involving surface
conduction, multi-component electrolytes, and Faradaic processes.Comment: 10 figs, 26 pages (double-column), 141 reference
МОРФОЛОГІЧНІ І МІКРОБІОЛОГІЧНІ ОСОБЛИВОСТІ ЗАГОЄННЯ ПОКРИВНИХ ТКАНИН ПІСЛЯ МІСЦЕВОГО ПРОМЕНЕВОГО ПОШКОДЖЕННЯ
Узагальнені результати комплексного експериментально-морфологічного дослідження особливостей загоєння променевої виразки шкіри (ПВШ), інфікованої Pseudomonas aeruginosa (P. aeruginosa), у порівнянні з неінфікованою ПВШ. Інфікована ПВШ характеризувалася багатошаровою будовою, що залежало від тривалості експерименту. Процеси загоєння інфікованої ПВШ у порівнянні з неінфікованою значно уповільнені
OS-2158 Interferon lambda 4 is associated with dysfunctional antibacterial immunity during alcohol-related liver disease
Mucosa-associated invariant T cells link intestinal immunity with antibacterial immune defects in alcoholic liver disease
Background/aims: Intestinal permeability with systemic distribution of bacterial products are central in the immunopathogenesis of alcoholic liver disease (ALD), yet links with intestinal immunity remain elusive. Mucosa-associated invariant T cells (MAIT) are found in liver, blood and intestinal mucosa and are a key component of antibacterial host defences. Their role in ALD is unknown.
Methods/design: We analysed frequency, phenotype, transcriptional regulation and function of blood MAIT cells in severe alcoholic hepatitis (SAH), alcohol-related cirrhosis (ARC) and healthy controls (HC). We also examined direct impact of ethanol, bacterial products from faecal extracts and antigenic hyperstimulation on MAIT cell functionality. Presence of MAIT cells in colon and liver was assessed by quantitative PCR and immunohistochemistry/gene expression respectively.
Results: In ARC and SAH, blood MAIT cells were dramatically depleted, hyperactivated and displayed defective antibacterial cytokine/cytotoxic responses. These correlated with suppression of lineage-specific transcription factors and hyperexpression of homing receptors in the liver with intrahepatic preservation of MAIT cells in ALD. These alterations were stronger in SAH, where surrogate markers of bacterial infection and microbial translocation were higher than ARC. Ethanol exposure in vitro, in vivo alcohol withdrawal and treatment with Escherichia coli had no effect on MAIT cell frequencies, whereas exposure to faecal bacteria/antigens induced functional impairments comparable with blood MAIT cells from ALD and significant MAIT cell depletion, which was not observed in other T cell compartments.
Conclusions: In ALD, the antibacterial potency of MAIT cells is compromised as a consequence of contact with microbial products and microbiota, suggesting that the ‘leaky’ gut observed in ALD drives MAIT cell dysfunction and susceptibility to infection in these patients
Peg-interferon lambda treatment induces robust innate and adaptive immunity in chronic hepatitis B patients
IFN-lambda (IFNλ) is a member of the type III IFN family and is reported to possess anti-pathogen, anti-cancer, and immunomodulatory properties; however, there are limited data regarding its impact on host immune responses in vivo. We performed longitudinal and comprehensive immunosurveillance to assess the ability of pegylated (peg)-IFNλ to augment antiviral host immunity as part of a clinical trial assessing the efficacy of peg-IFNλ in chronic hepatitis B (CHB) patients. These patients were pretreated with directly acting antiviral therapy (entecavir) for 12 weeks with subsequent addition of peg-IFNλ for up to 32 weeks. In a subgroup of patients, the addition of peg-IFNλ provoked high serum levels of antiviral cytokine IL-18. We also observed the enhancement of natural killer cell polyfunctionality and the recovery of a pan-genotypic HBV-specific CD4+ T cells producing IFN-γ with maintenance of HBV-specific CD8+ T cell antiviral and cytotoxic activities. It was only in these patients that we observed strong virological control with reductions in both viral replication and HBV antigen levels. Here, we show for the first time that in vivo peg-IFNλ displays significant immunostimulatory properties with improvements in the main effectors mediating anti-HBV immunity. Interestingly, the maintenance in HBV-specific CD8+ T cells in the presence of peg-IFNλ is in contrast to previous studies showing that peg-IFNa treatment for CHB results in a detrimental effect on the functionality of this important antiviral T cell compartment
Proučavanje 194Ir uhvatom termičkih neutrona I (d, p) reakcijom
Levels of 194Ir were studied using thermal neutron capture reaction. A pair spectrometer was used to measure the high-energy γ-ray spectrum from thermal-neutron capture in enriched 193Ir target over the energy range 4640 - 6100 keV. The low-energy γ-radiation from the reaction was studied with crystal diffraction spectrometers, and conversion electrons were observed with magnetic spectrometers. The high-sensitivity measurements at the Grenoble reactor, evaluated for transition energies up to 500 keV, are compared with lower-sensitivity measurements at the Wuerenlingen and Salaspils reactors. The comparison helped to obtain reliable isotopic identification for a number of 194Ir lines. The multipolarity admixtures for 29 γ-transitions were determined on the basis of conversion lines from different electron subshells. Prompt and delayed γ-γ coincidences were measured using semiconductor and scintillation detectors. The 193Ir(d,p) high-resolution spectra, observed with a magnetic spectrometer, are given. All these data contributed to establishing a detailed level scheme of 194Ir. Additional data and the interpretation of the results in terms of current models will be presented in a forthcoming paper.Proučavala su se stanja u 194Ir reakcijama 193Ir(n, γ) i 193Ir(d, p). Mjerenja uhvata termičkih neutrona načinjena su uz reaktore u Grenoblu, Wuerenlingenu i Salapsisu. Za mjerenja γ-zračenja visoke energije upotrebljavao se spektrometar parova, a za niske energije difraktometar. Konverzijske elektrone se mjerilo magnetskim spektrometrom. Mjerenja reakcije (d, p) visokog razlučivanja izvedena su magnetskim spektrometrom. Usporedbe tih mjerenja omogućile su pouzdano izotopno prepoznavanje prijelaza u 194 Ir, a spektri konverzijskih elektrona i određivanje multipolnosti prijelaza. Dobiveni su podaci osnova sheme raspada 194Ir
Коррекция нарушений микробиоценоза кишечника с помощью кишечного лаважа при острых отравлениях
Background. In acute poisoning, accompanied by a violation of microbiocenosis, the problem of its correction has not been studied enough.Aim of study. Evaluate the possibility of correcting violations of microbiocenosis using intestinal lavage in cases of poisoning with psychopharmacological preparations and cauterizing substances.Material and methods. 50 male (76.4%) and female (23.6%) patients aged 42 (36; 52) years with psychopharmacological drugs and cauterizing substances poisoning were examined, the composition of the fecal microflora was studied. A total of 100 studies of up to 10 species of microorganisms were conducted. In order to correct violations of the species composition of microbiocenosis, 30 patients underwent intestinal lavage. The comparison group included 20 patients who did not use intestinal lavage.Results. In patients with these poisonings, violations of the specific microbial composition of feces were detected. Intestinal lavage, in contrast to standard therapy, had a corrective effect on fecal microbiocenosis.Conclusion. With the help of intestinal lavage, it is possible to correct violations of microbiocenosis in acute poisoning in a short time. Актуальность. При острых отравлениях, сопровождающихся нарушением микробиоценоза кишечника, проблема его коррекции изучена недостаточно.Цель. Оценить возможность коррекции нарушений микробиоценоза кишечника с помощью кишечного лаважа (КЛ) при отравлениях психофармакологическими препаратами (ОПФП) и веществами прижигающего действия (ОВПД).Материал и методы. Обследованы 50 больных мужского (76,4%) и женского (23,6%) пола в возрасте 42 (36; 52) лет с ОПФП и ОВПД, которым исследовали состав микрофлоры фекалий. Всего было проведено 100 исследований, выделено 10 микроорганизмов в каждом исследовании. С целью коррекции нарушений качественного и количественного состава микробиоты 30 больным был проведен КЛ. 20 пациентов, которым КЛ не применяли, составили группу сравнения.Результаты. У больных с указанными отравлениями были выявлены нарушения микробного состава фекалий. Кишечный лаваж, в отличие от стандартной терапии, оказывал корригирующее влияние на микробиоценоз кишечника.Заключение. С помощью кишечного лаважа удается в короткий срок скорригировать нарушения микробиоценоза при острых отравлениях.
IT controls in the public cloud : success factors for allocation of roles and responsibilities
The rapid adoption of cloud computing by organizations has resulted in the transformation of the roles and responsibilities of staff in managing the information technology (IT) resources (via IT governance controls) that have migrated to the cloud. Hence, the objective of this research is to provide a set of success factors that can assist IT managers to allocate the roles and responsibilities
of IT controls appropriately to staff to manage the migrated IT resources. Accordingly, we generated a set of success factors from behavioral and information systems (IS) literature. These success factors were verified using in-depth interviews of executives from the United Arab Emirates (UAE).
The empirical intervention suggests that the role allocation is driven predominantly by people’s skills, competencies, organizational strategy, structures, and policies. In addition, the research made clear that the most significant competency and skill for a person allocated to IT controls is to be able to evaluate and manage a cloud service provider, especially in terms of risks, compliance, and security issues related to public cloud technology. The findings of this study not only offer new insights for scholars and practitioners involved in assigning responsibilities but also provide extensions for IT governance framework authorities to align their guidelines to the emerging cloud technology
Effect of prior treatments on selinexor, bortezomib, and dexamethasone in previously treated multiple myeloma
Therapeutic regimens for previously treated multiple myeloma (MM) may not provide prolonged disease control and are often complicated by significant adverse events, including peripheral neuropathy. In patients with previously treated MM in the Phase 3 BOSTON study, once weekly selinexor, once weekly bortezomib, and 40 mg dexamethasone (XVd) demonstrated a significantly longer median progression-free survival (PFS), higher response rates, deeper responses, a trend to improved survival, and reduced incidence and severity of bortezomib-induced peripheral neuropathy when compared with standard twice weekly bortezomib and 80 mg dexamethasone (Vd). The pre-specified analyses described here evaluated the influence of the number of prior lines of therapy, prior treatment with lenalidomide, prior proteasome inhibitor (PI) therapy, prior immunomodulatory drug therapy, and prior autologous stem cell transplant (ASCT) on the efficacy and safety of XVd compared with Vd. In this 1:1 randomized study, enrolled patients were assigned to receive once weekly oral selinexor (100 mg) with once weekly subcutaneous bortezomib (1.3 mg/m2) and 40 mg per week dexamethasone (XVd) versus standard twice weekly bortezomib and 80 mg per week dexamethasone (Vd). XVd significantly improved PFS, overall response rate, time-to-next-treatment, and showed reduced all grade and grade ≥ 2 peripheral neuropathy compared with Vd regardless of prior treatments, but the benefits of XVd over Vd were more pronounced in patients treated earlier in their disease course who had either received only one prior therapy, had never been treated with a PI, or had prior ASCT. Treatment with XVd improved outcomes as compared to Vd regardless of prior therapies as well as manageable and generally reversible adverse events. XVd was associated with clinical benefit and reduced peripheral neuropathy compared to standard Vd in previously treated MM. These results suggest that the once weekly XVd regimen may be optimally administered to patients earlier in their course of disease, as their first bortezomib-containing regimen, and in those relapsing after ASCT. Trial registration: ClinicalTrials.gov (NCT03110562). Registered 12 April 2017. https://clinicaltrials.gov/ct2/show/NCT03110562
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