The CDEX-1 experiment conducted a search of low-mass (< 10GeV/c super(2)) weakly interacting massive particles dark matter at the China Jinping Underground Laboratory using a p-type point-contact ...germanium detector with a fiducial mass of 915 g at a physics analysis threshold of 475 eVee. We report the hardware setup, detector characterization, data acquisition, and analysis procedures of this experiment. No excess of unidentified events is observed after the subtraction of the known background. Using 335.6 kg-days of data, exclusion constraints on the weakly interacting massive particle-nucleon spin-independent and spin-dependent couplings are derived.
This work demonstrates a highly sensitive peroxide test strip (PTS)-based enzyme-linked immunosorbent assay (ELISA) for both qualitative and quantitative detection of drugs of abuse (morphine) and ...disease biomarkers (interleukin-6 and HIV-1 capsid antigen p24). This color-based PTS is a commercially available product with advantages of low cost, easy operation, and portability, and it is an ideal signal readout strategy in ELISA to simplify the immunoassay procedures and enable point-of-care testing (POCT). In addition, we introduce the bioorthogonal reaction that can effectively amplify the signal by controlling the cycles of bioorthogonal reaction to achieve the desirable sensitivity depending on different analytes. The limit of detection is 0.2 ng/mL for morphine, 3.98 pg/mL for interleukin-6, and 11.6 pg/mL for detection of HIV-capsid antigen (p24). This PTS-ELISA applies to both the qualitative and quantitative detection of IL-6 and p24 in clinical serum samples with good accuracy, which provides a promising tool for the POCT in clinical diagnosis.
We report the results of searches for solar axions and galactic dark matter axions or axionlike particles with the CDEX-1 experiment at the China Jinping Underground Laboratory, using 335.6 kg days ...of data from a p-type point-contact germanium detector. The data are compatible with the background model, and no excess signals are observed. Limits of solar axions on the model-independent coupling gAe<2.5×10−11 from Compton, bremsstrahlung, atomic-recombination, and deexcitation channels and gANeff×gAe<6.4×10−17 from a Fe57 M1 transition at 90% confidence level are derived. Within the framework of the Dine-Fischler-Srednicki-Zhitnitskiy and Kim-Shifman-Vainshtein-Zakharov models, our results exclude the axion mass heavier than 0.9 and 177 eV/c2, respectively. The derived constraints for dark matter axions below 1 keV improve over the previous results.
Purpose: This study aimed to analyze first-choice medical institutions for middle-aged and older adults in Fujian Province to promote the development of hierarchical diagnosis and treatment for them. ...Patients and Methods: Single factor analysis, disordered multi-classification logistic regression, and multiple correspondence classification were used to analyze the influencing factors of first-choice medical institutions for middle-aged and older adults. A total of 486 valid questionnaires were obtained. The questionnaire was based on Health Service Integration Theory and the behavioral model of Andersen. Results: Age, education level, living area, monthly income, nearest medical institution to home, and integrated health service system understanding significantly influenced respondents' preference of first medical institution. Middle-aged and older adults were more inclined to visit county and municipal hospitals first. The treatment center's proximity was also an important determinant of their first-choice selection of medical care. Conclusion: To realize high-quality hierarchical diagnosis and treatment and integrated health service system construction, it is important to improve the service capacity of primary medical institutions, increase the training of family doctors, implement the contract coverage of family doctors, optimize the allocation and geographical layout of primary medical institutions, ensure adequate income levels, and promote township hospital staff. Keywords: hierarchical diagnosis, middle-aged adult, older adult, first medical institution, influencing factors
Purpose: To establish an in vitro lipotoxicity model with mouse cardiomyocytes (MCMs) and investigate the molecular mechanism of the peroxisome proliferator-activated receptors (PPAR) signaling on ...mitochondrial energy metabolism disorder and cellular injury in diabetic cardiomyopathy (DCM). Methods: Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed on the differentially expressed genes (DEGs) of DCM. CCK-8 method was used to detect the proliferation inhibition effect of palmitate (PA) on MCMs. Oil red O staining and mRNA levels of CD36 were used to verify intracellular lipid accumulation. DCFH-DA method was used to determine the content of intracellular reactive oxygen species (ROS), and ATP levels were detected by the ATP Detection Kit. Transmission electron microscope (TEM) was used to observe the mitochondrial structure. Western blot was used to detect the expression levels of PPARalpha, PPARgamma, P-mTOR, mTOR, PGC-1alpha, UCP2, and BNP. In addition, the expression of PPARgamma was also detected by cellular immunofuorescence staining. BNP levels were detected by qRT-PCR and the ELISA Kit. Results: KEGG pathway analysis combined with GO analysis has shown that PPAR signaling played a significant regulatory role in mitochondrial biogenesis and fatty acid metabolism in DCM. Then, MCMs stimulated with PA for 24 h were selected as an in vitro lipotoxicity model. PA decreased cell viability, cell membrane shrinkage, and lipid accumulation. Meanwhile, PA-induced increase in cellular ROS led to ATP generation reduction and mitochondrial damage. Furthermore, the expression levels of p-mTOR- PPARalpha/gamma were decreased, and the expressions of PGC-1alpha and UCP2 were increased. The levels of BNP were elevated, demonstrating PA impaired cardiomyocytes. Conclusion: Mtochondrial energy metabolism obstacle and cell injury appeared in cardiac lipotoxicity of DCM, associated with lipid accumulation and increased ROS, indicating a crosstalk with the PPAR pathway mediated mechanism. Keywords: diabetic cardiomyopathy, lipotoxicity, mitochondrial energy metabolism, cell damage, PPAR
A systematic study of the Mn-site substitution by M = Al, Cr, Fe, Co, Ni, Cu, and Ga in polycrystalline La0.7Sr0.3Mn0.9M0.1O3 compounds has been carried out. It was deduced from the experimental data ...that the magnetic coupling between the M and Mn ions is antiferromagnetic for Cr3+ and Fe3+, and ferromagnetic for Co2+/3+, Ni2+, and Cu2+. The variation of the Curie temperature versus M was discussed in terms of the double-exchange (DE) interaction of Mn3+OMn4+ as well as the superexchange interactions between the M and Mn ions. It is found that the Mn-site substitution by various M could not enhance the MR response at a low magnetic field of 2 kO.
Objective: Taxis play an important role in the transportation system of China, but they have a relatively high accident rate. The current study discusses the driver's financial burden in the Chinese ...context and explores its correlation with working conditions, risky driving behavior, and other characteristics of taxi drivers who are involved in accidents.
Method: A total of 2,391 taxi drivers from 29 companies in four Chinese cities were interviewed and then asked to complete a questionnaire concerning their socio-demographic characteristics, working conditions, risky driving behavior, and accident frequency during the previous two years. Given the increase in the management fee (measured in CNY) charged by taxi companies, the drivers were divided into three groups: the "less than 150" group, the" 150 to 180" group and the "over 180" group, where were named Group 1, Group 2 and Group 3, respectively. Finally, the zero-inflated Poisson model was used to investigate the factors that contributed to the accident rate for each group.
Result: The significant factors that lead to accidents differed significantly for drivers with different levels of financial burden. First, most of the factors were weakly correlated with the crash rate among Group 1 drivers. Second, many factors related to working conditions and risky driving behavior were significant for drivers in Groups 2 and 3, while working hours and off-duty days were significant only for drivers in Group 3. Third, working hours were negatively correlated with accident rates for drivers in Group 3, and the drivers who suffered from the heaviest financial burden were most affected by fatigue and sleep problems.
Conclusion: Financial burden is the root cause behind the propensity of taxi drivers to be involved in accidents. Taxi companies should find ways to reduce drivers' expenses, and new technologies, such as taxi-calling or location and navigation based on mobile applications, should be introduced into the traditional taxi industry.
Micro-sized sponge particulates have attracted extensive attention because of their potential to overcome the intrinsic limitations of conventional monolithic scaffolds in tissue engineering. ...Bioactive nanocomposite microsponges are regarded as potential bone substitute materials for bone regeneration.
Based on a combination of microfluidic emulsion with further freezing and in situ thawing, chitosan (CS)-hydroxyapatite (HAP) microsponges were prepared and characterized in terms of their morphology and elemental distribution using a scanning electron microscope equipped with an X-ray detector. The swelling ratio, porosity, degradability, antibacterial activity, and bioactivity were detected and analyzed. The biological functions of the CS-HAP microsponges were examined to assess the adhesion, proliferation, and differentiation of in vitro co-cultured rat bone marrow mesenchymal stem cells (rBMSCs). Furthermore, the CS-HAP microsponges were used as cell-free scaffolds and implanted into calvarial defects in a rat model to evaluate the in vivo osteogenesis.
The CS-HAP microsponges have a porous structure with high porosity (~76%), good swelling capacity (~1900%), and shape-memory properties. The results of in vitro experiments show that the CS-HAP microsponges achieve good bioactivity and promote osteogenic differentiation of rBMSCs. Furthermore, the CS-HAP microsponges significantly promote bone regeneration in rat calvarial defects.
The bioactive CS-HAP microsponges have the potential to be used as bone substitute materials for bone tissue engineering.
We report results of a search for light dark matter weakly interacting massive particles (WIMPs) with CDEX-1 experiment at the China Jinping Underground Laboratory, based on 53.9 kg-days of data from ...a p-type point-contact germanium detector enclosed by a Nal(TI) crystal scintillator as anti-Compton detector. The event rate and spectrum above the analysis threshold of 475 eVee are consistent with the understood background model. Part of the allowed regions for WIMP-nucleus coherent elastic scattering at WIMP mass of 6-20 GeV are probed and excluded. Independent of interaction channels, this result contradicts the interpretation that the anomalous excesses of the CoGeNT experiment are induced by dark matter, since identical detector techniques are used in both experiments.
Abstract A series of amphiphilic alternative block polyurethane copolymers based on poly(3-hydroxybutyrate- co -4-hydroxybutyrate) (P3/4HB) and poly(ethylene glycol) (PEG) were synthesized by a ...coupling reaction between P3/4HB-diol and PEG-diisocyanate, with different 3HB, 4HB, PEG compositions and segment lengths. Stannous octanoate was used as catalyst. The chemical structure, alternative block arrangement, molecular weight and distribution were systematically characterized by FTIR,1 H NMR, GPC and composition analysis. The thermal property was studied by DSC and TGA. Platelet adhesion study revealed that the alternative block polyurethanes possess excellent hemocompatibility. CCK-8 assay illuminated that the non-toxic block polyurethanes maintain rat aortic smooth muscle cells (RaSMCs) good viability. The in-vitro degradation of the copolymers in PBS buffer solution and in lipase buffer medium was investigated. Results showed that the copolymer films exhibit different degradation patterns in different media from surface erosion to diffusion bulk collapsing. The synthetic methodology for the alternative block polyurethanes provides a way to control the exact structure of the biomaterials and tailor the properties to subtle requirements.
PDF
