456 research outputs found
Major emerging and re-emerging zoonoses in China: a matter of global health and socioeconomic development for 1.3 billion
SummaryEmerging and re-emerging zoonoses are a significant public health concern and cause considerable socioeconomic problems globally. The emergence of severe acute respiratory syndrome (SARS), highly pathogenic avian influenza (HPAI) H5N1, avian influenza H7N9, and severe fever with thrombocytopenia syndrome (SFTS), and the re-emergence of rabies, brucellosis, and other zoonoses have had a significant effect on the national economy and public health in China, and have affected other countries. Contributing factors that continue to affect emerging and re-emerging zoonoses in China include social and environmental factors and microbial evolution, such as population growth, urbanization, deforestation, livestock production, food safety, climate change, and pathogen mutation. The Chinese government has devised new strategies and has taken measures to deal with the challenges of these diseases, including the issuing of laws and regulations, establishment of disease reporting systems, implementation of special projects for major infectious diseases, interdisciplinary and international cooperation, exotic disease surveillance, and health education. These strategies and measures can serve as models for the surveillance and response to continuing threats from emerging and re-emerging zoonoses in other countries
Recombination of Aromatic Radicals with Molecular Oxygen
International audienceThe addition of molecular oxygen to hydrocarbon radicals yields peroxy radicals (ROO), which are crucialspecies in both atmospheric and combustion chemistry. For aromatic radicals there is little known aboutthe recombination kinetics, especially for the high temperatures of relevance to combustion. Here, we haveemployed direct CASPT2 based variable reaction coordinate transition state theory to predict the high pres-sure recombination rates for four prototypical aromatic hydrocarbon radicals: phenyl, benzyl, 1-naphthyl,and 2-naphthyl. The variation in the predicted rates is discussed in relation to their molecular structure. Thepredicted rate coefficients are in reasonably satisfactory agreement with the limited experimental data andare expected to find utility in chemical modeling studies of PAH growth and oxidation
A class of pseudoinverse-free greedy block nonlinear Kaczmarz methods for nonlinear systems of equations
In this paper, we construct a class of nonlinear greedy average block
Kaczmarz methods to solve nonlinear problems without computing the
Moore-Penrose pseudoinverse. This kind of methods adopts the average technique
of Gaussian Kaczmarz method and combines with the greedy strategy, which
greatly reduces the amount of computation. The convergence analysis and
numerical experiments of the proposed method are given. The numerical results
show the effectiveness of the proposed methods
Ignored adult primary hypothyroidism presenting chiefly with persistent ovarian cysts: a need for increased awareness
<p>Abstract</p> <p>Background</p> <p>Ovarian cysts are a common cause for gynecological surgery. However, some cysts are a direct result of endocrine disorders and do not require surgery. This report describes an unusual case in which persistent ovarian cysts are associated with primary hypothyroidism in a young woman. The data were collected by history-taking, physical examination, laboratory tests, ultrasound, magnetic resonance imaging and a histo-pathological study. In addition, the exons of the gene encoding the human follicle-stimulating hormone receptor were sequenced.</p> <p>Discussion</p> <p>The patient had markedly elevated levels of thyroid-stimulating hormone and follicle-stimulating hormone and an enlarged pituitary gland. After treatment with thyroid hormone replacement, regression of the enlarged pituitary and the ovarian cysts was observed. The possible mechanisms of the pathophysiology are discussed below.</p> <p>Summary</p> <p>It is necessary to consider hypothyroidism and other endocrine disorders in the differential diagnosis of adult patients with ovarian multiple cyst formation in order to prevent inadvertent ovarian surgery.</p
Thickness dependence of superconductivity and superconductor-insulator transition in ultrathin FeSe films on SrTiO3(001) substrate
Interface-enhanced high-temperature superconductivity in one unit-cell (UC)
FeSe film on SrTiO3(001) (STO) substrate has recently attracted much attention
in condensed matter physics and material science. Here, by ex situ transport
measurements, we report on the superconductivity in FeSe ultra-thin films with
different thickness on STO substrate. We find that the onset superconducting
transition temperature (Tc) decreases with increasing film thickness of FeSe,
which is opposite to the behavior usually observed in traditional
superconductor films. By systematic post-annealing of 5 UC FeSe films, we
observe an insulator to superconductor transition, which is accompanied with a
sign change of the dominated charge carriers from holes to electrons at low
temperatures according to the corresponding Hall measurement
Post-training corticosterone inhibits the return of fear evoked by platform stress and a subthreshold conditioning procedure in Sprague-Dawley rats
The return of fear is an important issue in anxiety disorder research. Each time a fear memory is reactivated, it may further strengthen overactivation of the fear circuit, which may contribute to long-term maintenance of the fear memory. Recent evidence indicates that glucocorticoids may help attenuate pathological fear, but its role in the return of fear is unclear. In the present study, systemic corticosterone (CORT; 25 mg/kg) administration 1 h after fear conditioning did not impair the consolidation process but significantly suppressed the return of fear evoked by a subthreshold conditioning (SC) procedure and elevated platform (EP) stress. Compared with the SC-induced return of fear, acute stress-induced return was state-dependent. In addition, post-training CORT treatment increased the adrenocorticotropic response after EP stress, which indicates that the drug-induced suppression of the return of fear may possibly derive from its regulation effect of the hypothalamic-pituitary-adrenal axis reactivity to stress. These results suggest that post-training CORT administration may help inhibit the return of fear evoked by EP or SC stress. The possible mechanisms involved in the high-dose CORT-induced suppression of the SC- and EP-induced return of fear are discussed. (C) 2015 Elsevier Inc. All rights reserved.</p
Ovarian Hormonal Change-Related Energy Metabolism and Obesity in Menopausal Women
Obesity and its related severe consequences have been a major public health problem worldwide. A significant weight gain and intra-abdominal adipose tissue accumulation are observed as women begin the menopausal transition. A number of clinical and basic research indicate that ovarian hormone may play a crucial role. However, the underlying mechanisms are largely unknown. In this chapter, we aim to systematically review the literature in the influences of ovarian hormone on the physiology of lipid and glucose metabolism, obesity-related hormone, and the regulation of body weight by the dietary intake, feeding behavior. A variety of research modalities have been used to explore the effects of MHT in perimenopausal women. Hence, we will also summarize the latest progress of MHT use on the effect of body mass, body fat redistribution, and insulin resistance, which lead to protective cardiometabolic effects
Molecular Determinants of Magnolol Targeting Both RXRα and PPARγ
Nuclear receptors retinoic X receptor α (RXRα) and peroxisome proliferator activated receptor γ (PPARγ) function potently in metabolic diseases, and are both important targets for anti-diabetic drugs. Coactivation of RXRα and PPARγ is believed to synergize their effects on glucose and lipid metabolism. Here we identify the natural product magnolol as a dual agonist targeting both RXRα and PPARγ. Magnolol was previously reported to enhance adipocyte differentiation and glucose uptake, ameliorate blood glucose level and prevent development of diabetic nephropathy. Although magnolol can bind and activate both of these two nuclear receptors, the transactivation assays indicate that magnolol exhibits biased agonism on the transcription of PPAR-response element (PPRE) mediated by RXRα:PPARγ heterodimer, instead of RXR-response element (RXRE) mediated by RXRα:RXRα homodimer. To further elucidate the molecular basis for magnolol agonism, we determine both the co-crystal structures of RXRα and PPARγ ligand-binding domains (LBDs) with magnolol. Structural analyses reveal that magnolol adopts its two 5-allyl-2-hydroxyphenyl moieties occupying the acidic and hydrophobic cavities of RXRα L-shaped ligand-binding pocket, respectively. While, two magnolol molecules cooperatively accommodate into PPARγ Y-shaped ligand-binding pocket. Based on these two complex structures, the key interactions for magnolol activating RXRα and PPARγ are determined. As the first report on the dual agonist targeting RXRα and PPARγ with receptor-ligand complex structures, our results are thus expected to help inspect the potential pharmacological mechanism for magnolol functions, and supply useful hits for nuclear receptor multi-target ligand design
Spin Fluctuation Induced Linear Magnetoresistance in Ultrathin Superconducting FeSe Films
The discovery of high-temperature superconductivity in FeSe/STO has trigged
great research interest to reveal a range of exotic physical phenomena in this
novel material. Here we present a temperature dependent magnetotransport
measurement for ultrathin FeSe/STO films with different thickness and
protection layers. Remarkably, a surprising linear magnetoresistance (LMR) is
observed around the superconducting transition temperatures but absent
otherwise. The experimental LMR can be reproduced by magnetotransport
calculations based on a model of magnetic field dependent disorder induced by
spin fluctuation. Thus, the observed LMR in coexistence with superconductivity
provides the first magnetotransport signature for spin fluctuation around the
superconducting transition region in ultrathin FeSe/STO films
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