958 research outputs found
Epidemiological study on antimicrobial use and non-compliance with withdrawal times in broiler farms in Vietnam
L’utilisation d’antimicrobiens chez les animaux de consommation est une source de préoccupation importante pour la santé publique à travers le monde en raison de ses impacts potentiels sur l’émergence de micro-organismes résistants aux antimicrobiens et sur la présence de résidus antimicrobiens néfastes dans la viande. Cependant, dans les pays en développement, peu de données sont disponibles sur les pratiques d’utilisation des antimicrobiens à la ferme. Par conséquent, une étude épidémiologique transversale a été menée de juin à août 2011 dans des élevages de poulets de chair situés dans le sud du Vietnam, ayant pour objectifs de décrire la prévalence d’utilisation des antimicrobiens ajoutés à l’eau de boisson ou aux aliments à la ferme, et de tester les associations entre les caractéristiques des fermes et la non-conformité avec les périodes de retrait recommandés sur l’étiquette des produits. Un échantillon d’accommodement de 70 fermes a été sélectionné. Les propriétaires des fermes ont été interrogés en personne afin de compléter un questionnaire sur les caractéristiques des fermes et les pratiques d’utilisation d’antimicrobiens. Au cours des 6 mois précédant les entrevues, il a été rapporté que la colistine, la tylosine, l’ampicilline, l’enrofloxacine, la doxycycline, l’amoxicilline, la diavéridine et la sulfadimidine ont été utilisés au moins une fois dans les fermes échantillonnées, avec une fréquence descendante (de 75.7% à 30.0%). D’après deux scénarios de risque basés sur la comparaison de la période de retrait recommandée sur l’étiquette du produit et celle pratiquée à la ferme, de 14.3% à 44.3% des propriétaires de ferme interrogés n’ont pas respecté la période de retrait recommandée sur l’étiquette au moins une fois au cours des 6 derniers mois, et ce pour au moins un antimicrobien. Les facteurs de risque associés (p<0.05) avec une non-conformité avec la période de retrait recommandée sur l’étiquette pour au moins un des deux scénarios sont les suivants : élever des oiseaux qui n’appartiennent pas tous à des races d’origine asiatique, vacciner contre la bronchite infectieuse, avoir utilisé plus de 6 différents antimicrobiens à la ferme au cours des 6 derniers mois, et utiliser un mélange d’aliments fait maison et commerciaux. Nos résultats soulignent l’importance d’utiliser les antimicrobiens de façon judicieuse et en respectant les temps de retrait officiels, afin de protéger le consommateur contre les risques pour la santé causés par une exposition à des niveaux nocifs de résidus antimicrobiens.Antimicrobial use in food-animal husbandry is an important public health concern worldwide due to its potential impact on the emergence of drug-resistant microbes and its harmful residues in meat. However, in developing countries, few data are available on farm drug use practices. Therefore a cross-sectional epidemiological study was conducted on broiler chicken farms in Southern Vietnam from June 2011 to August 2011 with the aim of both describing prevalence of antimicrobials added to feed or water at the farm level and ascertaining any associations between farm characteristics and non-compliance of antimicrobial withdrawal times on labels. A convenient sample of 70 broiler farms was surveyed via personal interviews with farm owners using a questionnaire pertaining to farm characteristics and drug use practices. Over the 6-month period prior to the interviews, colistin, tylosin, ampicillin, enrofloxacin, doxycyclin, amoxicillin, diaveridin, and sulfadimidin were used at least once in descending frequency (from 75.7% to 30.0%) by the farms surveyed. Following two risk scenarios based on the comparison of recommended label withdrawal times with actual withdrawal times practiced during this period, between 14.3% and 44.3% of farmers did not comply with on-label withdrawal times for at least one antimicrobial. Risk factors associated (p<0.05) with non-compliance with on-label withdrawal times in at least one risk scenario were: raising birds other than Asian-indigenous bird breeds only, vaccinating against infectious bronchitis, using more than 6 different antimicrobials on a farm during the last 6 months prior to the interview, and mixing home-made and commercial feed. Our results underline the importance of using antimicrobials judiciously and respecting official withdrawal times in order to protect the consumer from the health risks caused by exposure to harmful levels of antimicrobial residues
Carbohydrates generated via hot water as catalyst for CO2 reduction reaction
Combining terrestrial biomass with submarine-type hydrothermal environments for CO2 reduction is a possible approach for realizing new energies while achieving sustainable circulation of carbon. Herein, carbohydrateenabled CO2 reduction based on NaHCO3 conversion to formate revealed that hydrothermal environments facilitated direct hydrogen transfer from carbohydrates (glucose, cellulose) to CO2/NaHCO3 with hot water (250–300 °C, 5–20 MPa) acting as homogeneous catalyst in absence of any conventional catalysts giving CO2/ NaHCO3 reduction efficiencies as high as 76% for cellulose. Time-resolved operando hydrothermal DRIFTS spectra of glycolaldehyde in hot water (250 °C, autogenous pressure) verified that water catalyzed NaHCO3 reduction by converting the -CHO group in the carbohydrate to its hydrated state as -CH(OH)2, which enabled NaHCO3 reduction by direct hydrogen transfer and that the ratio of hydrogen transfer from water:- glycolaldehyde for NaHCO3 reduction was about 13:87 on an atom basis. For cellulose exploited as energy input, a greater than 3.4% solar-to-formate efficiency can be theoretically attained, which is unprecedented compared with present literature values. These findings provide basic data for future studies on biomass-enabled CO2 reduction and broaden the scope of hydrothermal chemistry for developing net-zero emission processes
Suspension and Measurement of Graphene and Bi2Se3 Atomic Membranes
Coupling high quality, suspended atomic membranes to specialized electrodes
enables investigation of many novel phenomena, such as spin or Cooper pair
transport in these two dimensional systems. However, many electrode materials
are not stable in acids that are used to dissolve underlying substrates. Here
we present a versatile and powerful multi-level lithographical technique to
suspend atomic membranes, which can be applied to the vast majority of
substrate, membrane and electrode materials. Using this technique, we
fabricated suspended graphene devices with Al electrodes and mobility of 5500
cm^2/Vs. We also demonstrate, for the first time, fabrication and measurement
of a free-standing thin Bi2Se3 membrane, which has low contact resistance to
electrodes and a mobility of >~500 cm^2/Vs
Health-related quality of life in KEYNOTE-010 : a phase II/III study of pembrolizumab versus docetaxel in patients with previously treated advanced, programmed death ligand 1-expressing NSCLC
Introduction: In the phase II/III KEYNOTE-010 study (ClinicalTrials.gov, NCT01905657), pembrolizumab significantly prolonged overall survival over docetaxel in patients with previously treated, programmed death ligand 1-expressing (tumor proportion score >= 1%), advanced NSCLC. Health-related quality of life (HRQoL) results are reported here. Methods: Patients were randomized 1:1:1 to pembrolizumab 2 or 10 mg/kg every 3 weeks or docetaxel 75 mg/m(2) every 3 weeks. HRQoL was assessed using European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLC) Core 30 (C30), EORTC QLQ-Lung Cancer 13 (LC13), and EuroQoL-5D. Key analyses included mean baseline-to-week-12 change in global health status (GHS)/quality of life (QoL) score, functioning and symptom domains, and time to deterioration in a QLQ-LC13 composite endpoint of cough, dyspnea, and chest pain. Results: Patient reported outcomes compliance was high across all three instruments. Pembrolizumab was associated with better QLQ-C30 GHS/QoL scores from baseline to 12 weeks than docetaxel, regardless of pembrolizumab dose or tumor proportion score status (not significant). Compared with docetaxel, fewer pembrolizumab-treated patients had "deteriorated" status and more had "improved" status in GHS/QoL. Nominally significant improvement was reported in many EORTC symptom domains with pembrolizumab, and nominally significant worsening was reported with docetaxel. Significant prolongation in true time to deterioration for the QLQ-LC13 composite endpoint emerged for pembrolizumab 10 mg/kg compared to docetaxel (nominal two-sided p = 0.03), but not for the 2-mg/kg dose. Conclusions: These findings suggest that HRQoL and symptoms are maintained or improved to a greater degree with pembrolizumab than with docetaxel in this NSCLC patient population. (C) 2019 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.
Magnetoconductance Oscillations in High-Mobility Suspended Bilayer and Trilayer Graphene
We report pronounced magnetoconductance oscillations observed on suspended
bilayer and trilayer graphene devices with mobilities up to 270,000 cm2/Vs. For
bilayer devices, we observe conductance minima at all integer filling factors
nu between 0 and -8, as well as a small plateau at {\nu}=1/3. For trilayer
devices, we observe features at nu=-1, -2, -3 and -4, and at {\nu}~0.5 that
persist to 4.5K at B=8T. All of these features persist for all accessible
values of Vg and B, and could suggest the onset of symmetry breaking of the
first few Landau (LL) levels and fractional quantum Hall states.Comment: to appear in Phys. Rev. Let
An endoscopic modification of the simultaneous ‘above and below’ approach to large pituitary adenomas
Surgical resections of large-to-giant pituitary adenomas (PA) are technically challenging procedures. Tumors with a fibrous consistency or ‘hour-glass’ configurations are particularly difficult to remove completely and safely through the transsphenoidal route alone. Although the transcranial approach can facilitate the removal of a large suprasellar mass, it may be associated with significant bleeding within the intradural space. A simultaneous microscopic transcranial and transsphenoidal approach has been described as an alternative surgical strategy. We have further modified this ‘above and below’ approach by adopting endoscopic techniques for the transsphenoidal part of the procedure. This modified approach has the advantages of requiring only one operating microscope, and permitting freer maneuvers and easier orientation for both surgical teams. We present two patients successfully treated with this approach. Complete tumor removal was achieved and both patients achieved satisfactory functional recovery
Mathematical model of blood and interstitial flow and lymph production in the liver.
We present a mathematical model of blood and interstitial flow in the liver. The liver is treated as a lattice of hexagonal \u2018classic\u2019 lobules, which are assumed to be long enough that end effects may be neglected and a
two-dimensional problem considered. Since sinusoids and lymphatic vessels are numerous and small compared to the lobule, we use a homogenized approach, describing the sinusoidal and interstitial spaces as porous media. We model plasma filtration from sinusoids to the interstitium, lymph uptake by lymphatic ducts, and lymph outflow from the liver
surface. Our results show that the effect of the liver surface only penetrates a depth of a few lobules\u2019 thickness into the tissue. Thus, we separately consider a single lobule lying sufficiently far from all external boundaries that we may regard it as being in an infinite lattice, and also a model of the region near the liver surface. The model predicts that slightly more lymph is produced by interstitial fluid flowing through the liver surface than that taken up by the lymphatic vessels in the liver and that the on-peritonealized region of the surface of the liver results in the total lymph production (uptake by lymphatics plus fluid crossing surface) being about 5 % more than if the entire surface were covered by the Glisson\u2013peritoneal membrane. Estimates of lymph outflow through the surface of the liver are in good agreement with experimental data. We also study the effect of non-physiological values of the controlling parameters, particularly focusing
on the conditions of portal hypertension and ascites. To our knowledge, this is the first attempt to model lymph production in the liver. The model provides clinically relevant information about lymph outflow pathways and predicts the systemic response to pathological variations
Smc5/6 coordinates formation and resolution of joint molecules with chromosome morphology to ensure meiotic divisions
During meiosis, Structural Maintenance of Chromosome (SMC) complexes underpin two fundamental features of meiosis: homologous recombination and chromosome segregation. While meiotic functions of the cohesin and condensin complexes have been delineated, the role of the third SMC complex, Smc5/6, remains enigmatic. Here we identify specific, essential meiotic functions for the Smc5/6 complex in homologous recombination and the regulation of cohesin. We show that Smc5/6 is enriched at centromeres and cohesin-association sites where it regulates sister-chromatid cohesion and the timely removal of cohesin from chromosomal arms, respectively. Smc5/6 also localizes to recombination hotspots, where it promotes normal formation and resolution of a subset of joint-molecule intermediates. In this regard, Smc5/6 functions independently of the major crossover pathway defined by the MutLγ complex. Furthermore, we show that Smc5/6 is required for stable chromosomal localization of the XPF-family endonuclease, Mus81-Mms4Eme1. Our data suggest that the Smc5/6 complex is required for specific recombination and chromosomal processes throughout meiosis and that in its absence, attempts at cell division with unresolved joint molecules and residual cohesin lead to severe recombination-induced meiotic catastroph
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