239 research outputs found
ВИКОРИСТАННЯ ІМПУЛЬСНОГО МЕТОДУ ВИМІРЮВАННЬ ДЛЯ ВИЗНАЧЕННЯ ПОШКОДЖЕННЯ КАБЕЛЬНИХ ЛІНІЙ
В даній роботі розглядаються особливості
використання приладу ІКЛ-5 для швидкого
визначення точності імпульсних вимірювань в пошкодженнях кабельних ліній і точного
знаходження міста пошкодження кабелю. Для
досягнення поставленої мети запропонований
імпульсний метод, який визначає місце і характер пошкодження кабельних ліній. Обраний у роботі підхід дає можливість вимірювання при будьякому складному характері ушкодження. Завдяки цьому забезпечується зручність, простота і
швидкість вимірювань
Hyperinsulinemic-euglycemic Clamps in Conscious, Unrestrained Mice
Type 2 diabetes is characterized by a defect in insulin action. The hyperinsulinemic-euglycemic clamp, or insulin clamp, is widely considered the "gold standard" method for assessing insulin action in vivo. During an insulin clamp, hyperinsulinemia is achieved by a constant insulin infusion. Euglycemia is maintained via a concomitant glucose infusion at a variable rate. This variable glucose infusion rate (GIR) is determined by measuring blood glucose at brief intervals throughout the experiment and adjusting the GIR accordingly. The GIR is indicative of whole-body insulin action, as mice with enhanced insulin action require a greater GIR. The insulin clamp can incorporate administration of isotopic 2[14C]deoxyglucose to assess tissue-specific glucose uptake and [3-3H]glucose to assess the ability of insulin to suppress the rate of endogenous glucose appearance (endoRa), a marker of hepatic glucose production, and to stimulate the rate of whole-body glucose disappearance (Rd)
Socioeconomic position links circulatory microbiota differences with biological age
Imbalanced nutrition is associated with accelerated ageing, possibly mediated by microbiota. An analysis of the circulatory microbiota obtained from the leukocytes of participants in the MRC Twenty-07 general population cohort was performed. We now report that in this cohort, the most biologically aged exhibit a significantly higher abundance of circulatory pathogenic bacteria, including Neisseria, Rothia and Porphyromonas, while those less biologically aged possess more circulatory salutogenic (defined as being supportive of human health and wellbeing) bacteria, including Lactobacillus, Lachnospiraceae UCG-004 and Kocuria. The presence of these salutogenic bactreria is consistent with a capacity to metabolise and produce Nrf2 agonists. We also demonstrate that associated one carbon metabolism, notably betaine levels, did not vary with chronological age, but displayed a difference with socioeconomic position (SEP). Those at lower SEP possessed significantly lower betaine levels indicative of a poorer diet and poorer health span and consistent with reduced global DNA methylation levels in this group. Our data suggest a clear route to improving age related health and resilience based on dietary modulation of the microbiota
Measuring the impact of dietary supplementation with citrus or cucumber extract on chicken gut microbiota using 16s rRNA gene sequencing
This study investigated the effects of dietary supplements, citrus (CTS) and cucumber (CMB), on the jejunum and cecum microbiota of 14- and 28-days old broiler chickens to evaluate their impact on the gut health and assess their role as alternatives to antibiotic growth promoters (ABGPs). 16SrRNA gene sequencing revealed the overall bacterial microbiota composition was significantly affected by the gut site (p?<?0.001) but not by either of the dietary supplements, CTS and CMB, at both 14 and 28 days of age. However, as a result of Linear discriminant analysis (LDA) effect size (LEfSE), CTS dietary supplements significantly increased the counts of Lactobacillus (p?<?0.01) and decreased the counts of Enterococcus (p?<?0.01) and Clostridium (p?<?0.05) in the jejunum, whereas the counts of Blautia were increased (p?<?0.01) and Enterococcus were decreased (p?<?0.05) in the cecum at both ages. Only minor CMB effects were identified in the cecum and non in the jejunum. The use of CTS dietary supplements has been shown to be associated to the reduction of potentially pathogenic bacteria (Enterococcus and Clostridium) and to the growth of beneficial bacteria (Lactobacillus and Blautia) which are known to have positive effects on chicken health in terms of nutrients absorption, stimulation and production of short chain fatty acids (SCFAs). Therefore, this study suggests that the use of a CTS supplemented diet could promote gut health while no clear advantages have been identified with the use of CMB as a dietary supplement
Directional ballistic transport in the two-dimensional metal PdCoO2
This project was supported by the Max Planck Society and the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (MiTopMat, grant agreement no. 715730). M.D.B. and P.H.M. acknowledge EPSRC for PhD studentship support through grant number EP/L015110/1. Research in Dresden benefits from the environment of the Excellence Cluster ct.qmat. A.S. acknowledges support from an ARCS Foundation Fellowship, a Ford Foundation Predoctoral Fellowship and a National Science Foundation Graduate Research Fellowship. A.S. would thanks Z. Gomez and E. Huang for helpful discussions and T. Devereaux for letting us use his group cluster. Computational work was performed on the Sherlock cluster at Stanford University and on resources of the National Energy Research Scientific Computing Center, supported by the DOE under contract DE_AC02-05CH11231. T.S. acknowledges support from the Emergent Phenomena in Quantum Systems initiative of the Gordon and Betty Moore Foundation, and from the Natural Sciences and Engineering Research Council of Canada (NSERC), in particular the Discovery Grant (RGPIN-2020-05842), Accelerator Supplement (RGPAS-2020-00060) and Discovery Launch Supplement (DGECR-2020-00222). T.S. contributed to this work prior to joining AWS. D.G.-G.’s and A.W.B.’s involvement in calculations was supported by the US Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division under contract DE-AC02-76SF00515. E.Z. and M.M. thank the International Max Planck Research School for Chemistry and Physics of Quantum Materials (IMPRS-CPQM) for financial support. G.B. and D.A.B. acknowledge support from the Natural Sciences and Engineering Research Council of Canada (NSERC Discovery Grant RGPIN-2018-04280) and from the Canada First Research Excellence Fund.In an idealized infinite crystal, the material properties are constrained by the symmetries of the unit cell. The point-group symmetry is broken by the sample shape of any finite crystal, but this is commonly unobservable in macroscopic metals. To sense the shape-induced symmetry lowering in such metals, long-lived bulk states originating from an anisotropic Fermi surface are needed. Here we show how a strongly facetted Fermi surface and the long quasiparticle mean free path present in microstructures of PdCoO2 yield an in-plane resistivity anisotropy that is forbidden by symmetry on an infinite hexagonal lattice. We fabricate bar-shaped transport devices narrower than the mean free path from single crystals using focused ion beam milling, such that the ballistic charge carriers at low temperatures frequently collide with both of the side walls that define the channel. Two symmetry-forbidden transport signatures appear: the in-plane resistivity anisotropy exceeds a factor of 2, and a transverse voltage appears in zero magnetic field. Using ballistic Monte Carlo simulations and a numerical solution of the Boltzmann equation, we identify the orientation of the narrow channel as the source of symmetry breaking.Publisher PDFPeer reviewe
Job Insecurity and Future Labour Market Outcomes
This paper uses longitudinal survey data to test the degree to which measures of job insecurity are correlated with changes in labour market status. Three major findings are reported. First, the perceived probability of job loss is only weakly related to both exogenous job separations and subsequent transitions to unemployment and inactivity. Second, while fears of job loss tend to persist across time and job spells, they do so at a highly diminishing rate, suggesting that the impacts on other outcomes (such as psychological well-being) may be quite limited. Third, quit intentions are strongly correlated with both voluntary separations and transitions to alternative employment. The desire to quit, however, does not appear to diminish greatly across successive employment spells
A Compact Cold-Atom Interferometer with a High Data-Rate Grating Magneto-Optical Trap and a Photonic-Integrated-Circuit-Compatible Laser System
The extreme miniaturization of a cold-atom interferometer accelerometer
requires the development of novel technologies and architectures for the
interferometer subsystems. Here we describe several component technologies and
a laser system architecture to enable a path to such miniaturization. We
developed a custom, compact titanium vacuum package containing a
microfabricated grating chip for a tetrahedral grating magneto-optical trap
(GMOT) using a single cooling beam. In addition, we designed a multi-channel
photonic-integrated-circuit-compatible laser system implemented with a single
seed laser and single sideband modulators in a time-multiplexed manner,
reducing the number of optical channels connected to the sensor head. In a
compact sensor head containing the vacuum package, sub-Doppler cooling in the
GMOT produces 15 uK temperatures, and the GMOT can operate at a 20 Hz data
rate. We validated the atomic coherence with Ramsey interferometry using
microwave spectroscopy, then demonstrated a light-pulse atom interferometer in
a gravimeter configuration for a 10 Hz measurement data rate and T = 0 - 4.5 ms
interrogation time, resulting in g / g = 2.0e-6. This work represents
a significant step towards deployable cold-atom inertial sensors under large
amplitude motional dynamics.Comment: 21 pages, 10 figure
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Health-related quality of life in patients with a germline BRCA mutation and metastatic pancreatic cancer receiving maintenance olaparib
Background: Patients with metastatic pancreatic cancer often have a detriment in health-related quality of life (HRQoL). In the randomized, double-blind, phase III POLO trial progression-free survival was significantly longer with maintenance olaparib, a poly(ADP-ribose) polymerase inhibitor, than placebo in patients with a germline BRCA1 and/or BRCA2 mutation (gBRCAm) and metastatic pancreatic cancer whose disease had not progressed during first-line platinum-based chemotherapy. The prespecified HRQoL evaluation is reported here. Patients and methods: Patients were randomized to receive maintenance olaparib (300 mg b.i.d.; tablets) or placebo. HRQoL was assessed using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30-item module at baseline, every 4 weeks until disease progression, at discontinuation, and 30 days after last dose. Scores ranged from 0 to 100; a ≥10-point change or difference between arms was considered clinically meaningful. Adjusted mean change from baseline was analysed using a mixed model for repeated measures. Time to sustained clinically meaningful deterioration (TSCMD) was analysed using a log-rank test. Results: Of 154 randomized patients, 89 of 92 olaparib-arm and 58 of 62 placebo-arm patients were included in HRQoL analyses. The adjusted mean change in Global Health Status (GHS) score from baseline was <10 points in both arms and there was no significant between-group difference [-2.47; 95% confidence interval (CI) -7.27, 2.33; P = 0.31]. Analysis of physical functioning scores showed a significant between-group difference (-4.45 points; 95% CI -8.75, -0.16; P = 0.04). There was no difference in TSCMD for olaparib versus placebo for GHS [P = 0.25; hazard ratio (HR) 0.72; 95% CI 0.41, 1.27] or physical functioning (P = 0.32; HR 1.38; 95% CI 0.73, 2.63). Conclusions: HRQoL was preserved with maintenance olaparib treatment with no clinically meaningful difference compared with placebo. These results support the observed efficacy benefit of maintenance olaparib in patients with a gBRCAm and metastatic pancreatic cancer. ClincalTrials.gov number: NCT02184195
Associations with photoreceptor thickness measures in the UK Biobank.
Spectral-domain OCT (SD-OCT) provides high resolution images enabling identification of individual retinal layers. We included 32,923 participants aged 40-69 years old from UK Biobank. Questionnaires, physical examination, and eye examination including SD-OCT imaging were performed. SD OCT measured photoreceptor layer thickness includes photoreceptor layer thickness: inner nuclear layer-retinal pigment epithelium (INL-RPE) and the specific sublayers of the photoreceptor: inner nuclear layer-external limiting membrane (INL-ELM); external limiting membrane-inner segment outer segment (ELM-ISOS); and inner segment outer segment-retinal pigment epithelium (ISOS-RPE). In multivariate regression models, the total average INL-RPE was observed to be thinner in older aged, females, Black ethnicity, smokers, participants with higher systolic blood pressure, more negative refractive error, lower IOPcc and lower corneal hysteresis. The overall INL-ELM, ELM-ISOS and ISOS-RPE thickness was significantly associated with sex and race. Total average of INL-ELM thickness was additionally associated with age and refractive error, while ELM-ISOS was additionally associated with age, smoking status, SBP and refractive error; and ISOS-RPE was additionally associated with smoking status, IOPcc and corneal hysteresis. Hence, we found novel associations of ethnicity, smoking, systolic blood pressure, refraction, IOPcc and corneal hysteresis with photoreceptor thickness
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