83 research outputs found
The Need to Reconceptualize Wild Animals Post-COVID 19: Miscoordination of Wildlife Regulations in Chinaâs Food Legal Order
Today, China is one of the largest markets for wild animal trading. Yet, wild animals are in a regulatory grey area. There is an increasing need to revisit how wild animals are simultaneously but differently regulated in the food and wildlife protection regimes. Rarely do attempts to understand these two regimes occur, making this article\u27s analysis of miscoordination in these bodies of law crucial in addressing the hindrance of nationwide food safety improvement efforts
Etiology and clinical characteristics of fever of unknown origin in children: a 15-year experience in a single center
PurposeFever is one of the most common symptoms in children. In previous studies, infectious disease was the most common cause of pediatric fever of unknown origin (FUO). The aim of this study is to investigate the etiology, clinical characteristics and prognosis of pediatric FUO in 21 century with more diagnostics available and to analyze the factors for certain disease categories.MethodsAmong the children under 18 years old who were hospitalized at Samsung Medical Center from January 2000 to December 2014, the patients who met the criteria including fever of â„38.0â for longer than â„14 days and failure to reach a diagnosis after one week of investigations were included.ResultsTotal 100 patients were identified. Confirmed diagnosis was achieved in 57 patients (57%). Among them, infectious diseases (n=19, 19%) were most common, followed by connective tissue diseases (n=15, 15%), necrotizing lymphadenitis (n=8, 8%), and malignancies (n=7, 7%). Children with fever duration over 28 days had a trend for higher frequency of connective tissue diseases (28.3%) except undiagnosed etiology. The symptoms such as arthritis, lymph node enlargement and only fever without other symptoms were significantly related with connective tissue diseases, necrotizing lymphadenitis and undiagnosed respectively (P<0.001). Ninety-two patients have become afebrile at discharge and 1 patient died (1%).ConclusionAlmost half of our patients were left without diagnosis. Although it has been known that infectious disease was most common cause of pediatric FUO in the past, undiagnosed portion of FUO have now increased due to development of diagnostic techniques for infectious diseases
Implantable cardioverter defibrillator as a treatment for massive left ventricular fibroma-induced ventricular arrhythmia in a child
Pediatric cardiac tumors are rare. Among these, cardiac fibroma is the second most common. Its clinical manifestations depend on size and location of the tumor and include arrhythmia or obstruction to blood flow. Symptomatic cardiac fibroma is generally treated with surgical resection or cardiac transplantation. We present the case of a 12-year-old boy with a lethal ventricular arrhythmia induced by a remnant tumor that was previously partially resected. An implantable cardioverter defibrillator was inserted as the arrhythmia was resistant to medical treatment. He was discharged in stable condition with an implantable cardioverter defibrillator generator and followed up in the outpatient clinic
Nanoscale PerovskiteâSensitized Solar Cell Revisited: DyeâCell or PerovskiteâCell?
A general and straightforward way of preparing few nanometer-sized well-separated MAPbIxBr3-x perovskite photosensitizers on the
surface of ~1 ÎŒm thick mesoporous TiO2 photoanode was suggested via a two-step sequential deposition of low-concentrated lead halides
(0.10 ~ 0.30 M PbI2 or PbBr2) and methylammonium iodide/bromide (MAI/MABr). When those nanoscale MAPbIxBr3-x perovskites are
incorporated as a photosensitizer in typical solid state dye-sensitized solar cells (ss-DSSCs), it could be verified clearly by the capacitance
analysis that nano-particulate MAPbI3 perovskites are playing the same role as that of a typical dye sensitizer (MK-2 molecule) though their
size, composition and structure are different
Uric acid regulates α-synuclein transmission in Parkinsonian models
Ample evidence demonstrates that α-synuclein (α-syn) has a critical role in the pathogenesis of Parkinsonâs disease (PD) with evidence indicating that its propagation from one area of the brain to others may be the primary mechanism for disease progression. Uric acid (UA), a natural antioxidant, has been proposed as a potential disease modifying candidate in PD. In the present study, we investigated whether UA treatment modulates cell-to-cell transmission of extracellular α-syn and protects dopaminergic neurons in the α-syn-enriched model. In a cellular model, UA treatment decreased internalized cytosolic α-syn levels and neuron-to-neuron transmission of α-syn in donor-acceptor cell models by modulating dynamin-mediated and clathrin-mediated endocytosis. Moreover, UA elevation in α-syn-inoculated mice inhibited propagation of extracellular α-syn which decreased expression of phosphorylated α-syn in the dopaminergic neurons of the substantia nigra leading to their increased survival. UA treatment did not lead to change in markers related with autophagolysosomal and microglial activity under the same experimental conditions. These findings suggest UA may control the pathological conditions of PD via additive mechanisms which modulate the propagation of α-syn
Preparation of nanoscale inorganic CsPbIxBr3-x perovskite photosensitizers on the surface of mesoporous TiO2 film for solid-state sensitized solar cells
Metal chalcogenide quantum dot (QD)-like all-inorganic nanoscale perovskite photosensitizers of CsPbIxBr3-x were prepared on the surface of mesoscopic TiO2 film by a direct two-step spin-coating of lead and cesium halide precursors for application into solid-state dye-sensitized solar cells (DSSCs), as confirmed by impedance frequency response analysis. A few nanometer-sized hemisphere-shaped dots of CsPbIxBr3-x perovskites were deposited and distributed separately onto TiO2, which were checked by scanning and transmission electron microscopic (SEM and TEM) techniques. The as-deposited CsPbIxBr3-x perovskites were stable only in the case of including about 20% or more bromide in the composition of halides. When the bromide content increased in the ratio of halides of CsPbIxBr3-x, gradual decrease in lattice spacing and blue-shift of emission peaks were observed in X-ray diffraction (XRD) and photoluminescence (PL) measurements, respectively. These well-defined nano-particulate CsPbIxBr3-x perovskites were incorporated into solid-state DSSCs and tested as a new type of photosensitizers. The initial power conversion efficiency (PCE) of ca. 1.0â3.5% based on relatively thin mesoporous TiO2 film (~1 ÎŒm) looks promising with many parameters remaining for possibly more optimization. The best result, 3.79%, was obtained from CsPbI2.2Br0.80 25 days after initial measurement. These CsPbIxBr3-x-sensitized cells displayed a stable record of PCE over ~2 month and no hysteresis behavior in current-voltage traces
Crystal Structures of Malonyl-Coenzyme A Decarboxylase Provide Insights into Its Catalytic Mechanism and Disease-Causing Mutations
Malonyl-coenzyme A decarboxylase (MCD) is found from bacteria to humans, has important roles in regulating fatty acid metabolism and food intake, and is an attractive target for drug discovery. We report here four crystal structures of MCD from human, Rhodopseudomonas palustris, Agrobacterium vitis, and Cupriavidus metallidurans at up to 2.3Â Ă
resolution. The MCD monomer contains an N-terminal helical domain involved in oligomerization and a C-terminal catalytic domain. The four structures exhibit substantial differences in the organization of the helical domains and, consequently, the oligomeric states and intersubunit interfaces. Unexpectedly, the MCD catalytic domain is structurally homologous to those of the GCN5-related N-acetyltransferase superfamily, especially the curacin A polyketide synthase catalytic module, with a conserved His-Ser/Thr dyad important for catalysis. Our structures, along with mutagenesis and kinetic studies, provide a molecular basis for understanding pathogenic mutations and catalysis, as well as a template for structure-based drug design
Analytical approach to bit-string models of language evolution
A formulation of bit-string models of language evolution, based on
differential equations for the population speaking each language, is introduced
and preliminarily studied. Connections with replicator dynamics and diffusion
processes are pointed out. The stability of the dominance state, where most of
the population speaks a single language, is analyzed within a mean-field-like
approximation, while the homogeneous state, where the population is evenly
distributed among languages, can be exactly studied. This analysis discloses
the existence of a bistability region, where dominance coexists with
homogeneity as possible asymptotic states. Numerical resolution of the
differential system validates these findings.Comment: To appear in Int. J. Mod. Phys.
The Case of Anticipating Changes in the North Korean Food Safety Regime
40 pagesThis Article aims to provide one of the worldâs first analyses of the North Korean food safety regime. Very rarely has this regime been a subject of discussion, as much attention has been diverted to food security issues. However, food safety remains a critical problem for the people
Implementation of Biomimicry for Detecting Composite Structure Damage Using Impedance-Based Non-Destructive Testing Method
Up to date, biomimicry has aided in designing novel ideas and solving various problems in the field of civil engineering. For example, the concept of a load carrying process from a tree can be used to design an effective bridge. Inspired by nature, the authors have adopted the concept of how spiders use vibrations to monitor the state of the web and the presence of prey. A nondestructive testing method known as the electromechanical impedance technique has been proven to be effective when detecting local damage. However, the aforementioned technique uses a high frequency which results in a limited sensing range. Thus, to overcome this problem, an idea using the piezoelectric transducer combined with wires was introduced and tested against composite plates subjected to debonding damage. From the experiment results, the concept introduced from this research shows that biomimicry can increase the sensing range for electromechanical impedance technique which may allow one to create a monitoring system with minimal cost
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