2,274 research outputs found
The evolution of health policy in China and internal migrants: Continuity, change, and current implementation challenges
Rural–urban migration is a defining feature of socio-economic change in contemporary China. It is estimated that internal migrants in China account for 20% of its population of 1.39 billion, providing manpower to the expanding urban industries. Yet internal migrants have long faced barriers to accessing health and other social services in urban destinations, and the migration process may expose them to novel health risks and inequities. Based on the analysis of policy documents and associated material, this article reviews the historical development of health policy in China in relation to internal migrants, identifying elements of continuity and change in the policy agenda and the ways in which migrants have been framed in policy formulations. Against this background, remaining gaps in the current policy framework and implementation challenges are discussed
Three-photon absorption in water-soluble ZnS nanocrystals
We report on large three-photon absorption (3PA) in glutathione-capped ZnS
semiconductor nanocrystals (NCs), determined by both Z-scan and transient
transmission techniques with 120-fs laser pulses. The monodispersed,
water-soluble ZnS NCs are synthesized by a modified protocol with a mean
diameter of 2.5 nm. Their 3PA cross-section is determined to be around
2.7x10^-78 cm^6s^2photon^-2 at an optimal wavelength of commercial Ti:sapphire
femtosecond lasers. This value is nearly one order of magnitude greater than
that of CdS NCs, and four to five orders of magnitude higher than those of the
previously reported common UV fluorescent dyes.Comment: 15 pages, 4 figure
Preparation and properties of asphalt binders modified by THFS extracted from direct coal liquefaction residue
This paper aims to study the preparation and viscoelastic properties of asphalt binder modified by tetrahydrofuran soluble fraction (THFS) extracted from direct coal liquefaction residue. The modified asphalt binders, which blended with SK-90 (control asphalt binder) and 4%, 6%, 8% and 10% THFS (by weight of SK-90), were fabricated. The preparation process for asphalt binder was optimized in terms of the orthogonal array test strategy and gray correlation analysis results. The properties of asphalt binder were measured by applying Penetration performance grade and Superpave performance grade specifications. In addition, the temperature step and frequency sweep test in Dynamic Shear Rheometer were conducted to predict the rheological behavior, temperature and frequency susceptibility of asphalt binder. The test results suggested the optimal preparation process, such as 150 °C shearing temperature, 45 min shearing time and 4000 rpm shearing rate. Subsequently, the addition of THFS was beneficial in increasing the high-temperature properties but decreased the low-temperature properties and resistance to fatigue. The content analysis of THFS showed the percentage of 4~6% achieved a balance in the high-and-low temperature properties of asphalt binder. The asphalt binder with higher THFS content exhibited higher resistance to rutting and less sensitivity to frequency and temperature
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Promoting H2O2 production via 2-electron oxygen reduction by coordinating partially oxidized Pd with defect carbon.
Electrochemical synthesis of H2O2 through a selective two-electron (2e-) oxygen reduction reaction (ORR) is an attractive alternative to the industrial anthraquinone oxidation method, as it allows decentralized H2O2 production. Herein, we report that the synergistic interaction between partially oxidized palladium (Pdδ+) and oxygen-functionalized carbon can promote 2e- ORR in acidic electrolytes. An electrocatalyst synthesized by solution deposition of amorphous Pdδ+ clusters (Pd3δ+ and Pd4δ+) onto mildly oxidized carbon nanotubes (Pdδ+-OCNT) shows nearly 100% selectivity toward H2O2 and a positive shift of ORR onset potential by ~320 mV compared with the OCNT substrate. A high mass activity (1.946 A mg-1 at 0.45 V) of Pdδ+-OCNT is achieved. Extended X-ray absorption fine structure characterization and density functional theory calculations suggest that the interaction between Pd clusters and the nearby oxygen-containing functional groups is key for the high selectivity and activity for 2e- ORR
A study on blocking store-operated Ca2+ entry in pulmonary arterial smooth muscle cells with xyloketals from marine fungi
In this study, the effect of four xyloketal compounds 1-4 on store-operated calcium entry (SOCE) was investigated in primary distal pulmonary arterial smooth muscle cells (PASMCs) isolated from mice. The results showed that xyloketal A (1), an unusual ketal compound with C-3 symmetry, exhibited strong SOCE blocking activity. Secretion of interleukin-8 (IL-8) was also inhibited by xyloketal A. The parallel artificial membrane permeability assay (PAMPA) of 1-4 suggested that these xyloketals were easily penetrable through the cell membrane. Moreover, the molecular docking study of xyloketal A with activation region of the stromal interaction molecule (STIM) 1 and the calcium release-activated calcium modulator (ORAI) 1 (STIM1-ORAI1) protein complex, the key domain of SOCE, revealed that xyloketal A exibited non-covalent interaction with the key residue lysine 363 (LYS363) in the identified cytosolic regions in STIM1-C. These findings provided useful information for xyloketal A as SOCE inhibitor for further evaluation
Deficiency of Mkrn2 causes abnormal spermiogenesis and spermiation, and impairs male fertility.
Although recent studies have shed insights on some of the potential causes of male infertility, new underlining molecular mechanisms still remain to be elucidated. Makorin-2 (Mkrn2) is an evolutionarily conserved gene whose biological functions are not fully known. We developed an Mrkn2 knockout mouse model to study the role of this gene, and found that deletion of Mkrn2 in mice led to male infertility. Mkrn2 knockout mice produced abnormal sperms characterized by low number, poor motility, and aberrant morphology. Disruption of Mkrn2 also caused failure of sperm release (spermiation failure) and misarrangement of ectoplasmic specialization (ES) in testes, thus impairing spermiogenesis and spermiation. To understand the molecular mechanism, we found that expression of Odf2, a vital protein in spermatogenesis, was significantly decreased. In addition, we found that expression levels of Odf2 were decreased in Mkrn2 knockout mice. We also found that MKRN2 was prominently expressed in the sperm of normal men, but was significantly reduced in infertile men. This result indicates that our finding is clinically relevant. The results of our study provided insights into a new mechanism of male infertility caused by the MKRN2 downregulation
Loop-Mediated Isothermal Amplification Assay Targeting the MOMP Gene for Rapid Detection of Chlamydia psittaci Abortus Strain
For rapid detection of the Chlamydia psittaci abortus strain, a loop-mediated isothermal amplification (LAMP) assay was developed and evaluated in this study. The primers for the LAMP assay were designed on the basis of the main outer membrane protein (MOMP) gene sequence of C. psittaci. Analysis showed that the assay could detect the abortus strain of C. psittaci with adequate specificity. The sensitivity of the test was the same as that of the nested-conventional PCR and higher than that of chick embryo isolation. Testing of 153 samples indicated that the LAMP assay could detect the genome of the C. psittaci abortus strain effectively in clinical samples. This assay is a useful tool for rapid diagnosis of C. psittaci infection in sheep, swine and cattle
Downregulation of CD4+LAP+ and CD4+CD25+ Regulatory T Cells in Acute Coronary Syndromes
Detection of DC electric forces with zeptonewton sensitivity by single-ion phonon laser
Detecting extremely small forces helps exploring new physics quantitatively.
Here we demonstrate that the phonon laser made of a single trapped
Ca ion behaves as an exquisite sensor for small force measurement.
We report our successful detection of small electric forces regarding the DC
trapping potential with sensitivity of 2.410.49 zN/, with
the ion only under Doppler cooling, based on the injection-locking of the
oscillation phase of the phonon laser in addition to the classical squeezing
applied to suppress the measurement uncertainty. We anticipate that such a
single-ion sensor would reach a much better force detection sensitivity in the
future once the trapping system is further improved and the fluorescence
collection efficiency is further enhanced.Comment: arXiv admin note: text overlap with arXiv:2110.0114
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