100 research outputs found
Equity in use of maternal health services in Western Rural China: a survey from Shaanxi province
BACKGROUND: The 20(th) century was marked by a significant improvement in worldwide human health and access to healthcare. However, these improvements were not completely or uniformly distributed among, or even within, nations. This study was designed to assess the use of maternal health services by pregnant women in China, with a focus on the inequity related to family income level. METHODS: Two population-based cross-sectional surveys were carried out in the Zhenan and Lantian counties in March 2007 and from December 2008 to March 2009. A total of 2562 women completed the questionnaires, including 948 who were pregnant in 2006 and 1614 from 2008–2009. The concentration index (CI) was calculated and used to analyze the parameters of maternal health care in the two counties surveyed. RESULTS: The responses in both 2006 and 2008–2009 indicated a bias towards higher (rich) economic statuses for the use of maternal and child health services. The CI of ‘delivery at health facility’ was 0.0206 (95% confidence interval between 0.0114 and 0.0299) for 2006 and 0.0053 (95% confidence interval between 0.0015 and 0.0091) for 2008, which represented a statistically significant inequity for women of lower (poor) economic statuses. Similar CI was observed in ‘receiving antenatal care within 12 weeks’ for 2006 (CI(2006) = 0.0956, 95% confidence interval between 0.0516 and 0.1396). The CIs of ‘postnatal visit’ and ‘postnatal visit >3-times’ was positive (except for 2006), indicating that the poor used postnatal care less than the non-poor. In 2008, poor women had C-sections more often than non-poor women (CI(2008) = −0.0629, 95% confidence interval between-0.1165 and −0.0093), but such a difference was not observed in 2006. CONCLUSIONS: In 2006 and 2008, the use of maternal health services in western rural China was significantly unequal between pregnant women of poor and non-poor economic statuses. Financial support that enables poorer pregnant women to use health services will be beneficial. Utilization of maternal healthcare services can be improved if out-of-pocket expenses can be minimized
Comparison of Depressive Symptoms and Its Influencing Factors among the Elderly in Urban and Rural Areas: Evidence from the China Health and Retirement Longitudinal Study (CHARLS)
Depression amongst the elderly population is a worldwide public health problem, especially in China. Affected by the urban–rural dual structure, depressive symptoms of the elderly in urban and rural areas are significantly different. In order to compare depressive symptoms and its influencing factors among the elderly in urban and rural areas, we used the data from the fourth wave of the China Health and Retirement Longitudinal Study (CHARLS). A total of 7690 participants at age 60 or older were included in this study. The results showed that there was a significant difference in the prevalence estimate of depression between urban and rural elderly (χ2 = 10.9.76, p 0.001). The prevalence of depression among rural elderly was significantly higher than that of urban elderly (OR-unadjusted = 1.88, 95% CI: 1.67 to 2.12). After adjusting for gender, age, marital status, education level, minorities, religious belief, self-reported health, duration of sleep, life satisfaction, chronic disease, social activities and having income or not, the prevalence of depression in rural elderly is 1.52 times (OR = 1.52, 95% CI: 1.32 to 1.76) than that of urban elderly. Gender, education level, self-reported health, duration of sleep, chronic diseases were associated with depression in both urban and rural areas. In addition, social activities were connected with depression in urban areas, while minorities, marital status and having income or not were influencing factors of depression among the rural elderly. The interaction analysis showed that the interaction between marital status, social activities and urban and rural sources was statistically significant (divorced: coefficient was 1.567, p 0.05; social activities: coefficient was 0.340, p 0.05), while gender, education level, minorities, self-reported health, duration of sleep, life satisfaction, chronic disease, social activities having income or not and urban and rural sources have no interaction (p > 0.05). Thus, it is necessary to propose targeted and precise intervention strategies to prevent depression after accurately identifying the factors’ effects
RNA Helicase DDX17 Inhibits Hepatitis B Virus Replication by Blocking Viral Pregenomic RNA Encapsidation
DDX17 is a member of the DEAD-box helicase family proteins involved in cellular RNA folding, splicing, and translation. It has been reported that DDX17 serves as a cofactor of host zinc finger antiviral protein (ZAP)-mediated retroviral RNA degradation and exerts direct antiviral function against Raft Valley fever virus through binding to specific stem-loop structures of viral RNA. Intriguingly, we have previously shown that ZAP inhibits hepatitis B virus (HBV) replication through promoting viral RNA decay, and the ZAP-responsive element (ZRE) of HBV pregenomic RNA (pgRNA) contains a stem-loop structure, specifically epsilon, which serves as the packaging signal for pgRNA encapsidation. In this study, we demonstrated that the endogenous DDX17 is constitutively expressed in human hepatocyte-derived cells but dispensable for ZAP-mediated HBV RNA degradation. However, DDX17 was found to inhibit HBV replication primarily by reducing the level of cytoplasmic encapsidated pgRNA in a helicase-dependent manner. Immunofluorescence assay revealed that DDX17 could gain access to cytoplasm from nucleus in the presence of HBV RNA. In addition, RNA immunoprecipitation and electrophoretic mobility shift assays demonstrated that the enzymatically active DDX17 competes with HBV polymerase to bind to pgRNA at the 5' epsilon motif. In summary, our study suggests that DDX17 serves as an intrinsic host restriction factor against HBV through interfering with pgRNA encapsidation. IMPORTANCE Hepatitis B virus (HBV) chronic infection, a long-studied but yet incurable disease, remains a major public health concern worldwide. Given that HBV replication cycle highly depends on host factors, deepening our understanding of the host-virus interaction is thus of great significance in the journey of finding a cure. In eukaryotic cells, RNA helicases of the DEAD box family are highly conserved enzymes involved in diverse processes of cellular RNA metabolism. Emerging data have shown that DDX17, a typical member of the DEAD box family, functions as an antiviral factor through interacting with viral RNA. In this study, we, for the first time, demonstrate that DDX17 inhibits HBV through blocking the formation of viral replication complex, which not only broadens the antiviral spectrum of DDX17 but also provides new insight into the molecular mechanism of DDX17-mediated virus-host interaction
End-of-treatment anti-HBs levels and HBeAg status identify durability of HBsAg loss after PEG-IFN discontinuation
BackgroundHepatitis B surface antigen (HBsAg) loss, namely, the functional cure, can be achieved through the pegylated interferon (PEG-IFN)-based therapy. However, it is an unignorable fact that a small proportion of patients who achieved functional cure develop HBsAg reversion (HRV) and the related factors are not well described.MethodsA total of 112 patients who achieved PEG-IFN-induced HBsAg loss were recruited. HBV biomarkers and biochemical parameters were examined dynamically. HBV RNA levels were assessed in the cross-sectional analysis. The primary endpoint was HRV, defined as the reappearance of HBsAg after PEG-IFN discontinuation.ResultsHRV occurred in 17 patients during the follow-up period. Univariable analysis indicated that hepatitis B e antigen (HBeAg) status, different levels of hepatitis B surface antibody (anti-HBs), and hepatitis B core antibody (anti-HBc) at the end of PEG-IFN treatment (EOT) were significantly associated with the incidence of HRV through using the log-rank test. Additionally, time-dependent receiver operating characteristic (ROC) analysis showed that the anti-HBs was superior to anti-HBc in predictive power for the incidence of HRV during the follow-up period. Multivariable Cox proportional hazard analysis found that anti-HBs ≥1.3 log10IU/L (hazard ratio (HR), 0.148; 95% confidence interval (CI), 0.044-0.502) and HBeAg negativity (HR, 0.183; 95% CI, 0.052-0.639) at EOT were independently associated with lower incidence of HRV. Cross-sectional analysis indicated that the HBV RNA levels were significantly correlated with the HBsAg levels in patients with HRV (r=0.86, p=0.003).ConclusionsEOT HBeAg negativity and anti-HBs ≥1.3 log10IU/L identify the low risk of HRV after PEG-IFN discontinuation
Testing the competition-colonization trade-off and its correlations with functional trait variations among subtropical tree species
The competition-colonization trade-off, by which species can partition spatial niches, is a potentially important mechanism allowing the maintenance of species diversity in plant communities. We examined whether there was evidence for this trade-off among tree species in a subtropical forest and how it correlated with eight functional traits. We developed and estimated a metric for colonization ability that incorporates both fecundity and seed dispersal based on seed trap data and the sizes and distributions of adult trees. Competitive ability was estimated as survival probability under high crowding conditions based on neighborhood models. Although we found no significant relationship between colonization and competitive abilities, there was a significant negative correlation between long distance dispersal ability and competitive ability at the 5 cm size class. Colonizers had traits associated with faster growth, such as large leaves and low leaf lamina density, whereas competitors had traits associated with higher survival, such as dense wood. Our results imply that any trade-off between competition and colonization may be more determined by dispersal ability than by fecundity, suggesting that seed dispersal is an important contributor to diversity maintenance. Future work should test how competitive ability covaries with the components of colonization ability, as we did here
Mean Square Exponential Stability of Stochastic Delay Differential Systems with Logic Impulses
This paper focuses on the mean square exponential stability of stochastic delay differential systems with logic impulses. Firstly, a class of nonlinear stochastic delay differential systems with logic impulses is constructed. Then, the logic impulses are transformed into an equivalent algebraic expression by using the semi-tensor product method. Thirdly, the mean square exponential stability criteria of nonlinear stochastic delay differential systems with logic impulses are given. Finally, two kinds of stochastic delay differential systems with logic impulses and uncertain parameters are discussed, and the coefficient conditions guaranteeing the mean square exponential stability of these systems are obtained
Microstructure and Texture Evolution in Low Carbon and Low Alloy Steel during Warm Deformation
Warm compression tests were carried out on low carbon and low alloy steel at temperatures of 600–850 °C and stain rates of 0.01–10 s−1. The evolution of microstructure and texture was studied using a scanning electron microscope and electron backscattered diffraction. The results indicated that cementite spheroidization occurred and greatly reduced at 750 °C due to a phase transformation. Dynamic recrystallization led to a transition from {112}<110> texture to {111}<112> texture. Below 800 °C, the intensity and variation of texture with deformation temperature is more significant than that above 800 °C. The contents of the {111}<110> texture and {111}<112> texture were equivalent above 800 °C, resulting in the better uniformity of γ-fiber texture. Nucleation of <110>//ND-oriented grains increased, leading to the strengthening of <110>//ND texture. Microstructure analysis revealed that the uniform and refined grains can be obtained after deformation at 800 °C and 850 °C. The texture variation reflected the fact that 800 °C was the critical value for temperature sensitivity of warm deformation. At a large strain rate, the lowest dislocation density appeared after deformation at 800 °C. Therefore, 800 °C is a suitable temperature for the warm forming application, where the investigated material is easy to deform and evolves into a uniform and refined microstructure
NMR technology in reservoir evaluation for shale oil and gas
Since the development of unconventional oil and gas business, Nuclear Magnetic Resonance (NMR) technology has been gradually applied in the evaluation for unconventional reservoirs due to the merits such as nondestructive, sensitive and fast, this technology has become one of the important methods in shale oil and gas reservoir evaluation. Therefore, based on the experimental principle of NMR technology, this paper focuses on the applications of NMR technology in the full-scale integrated characterization of pore and fracture distribution, characterization of shale porosity, pore wettability, fluid mobility and fluid classification, etc. In addition, the applications of NMR in describing water migration, methane adsorption and desorption, carbon dioxide displacement and other fluid behaviors, obtaining organic matter information, oil shale interface area, determining organic pores and inorganic pores, analyzing pore connectivity, and obtaining information about high-viscosity asphalt and kerogen are also briefly reviewed. Finally, the shortcomings of NMR and the development trend of NMR in shale reservoir evaluation are analyzed
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