28 research outputs found
HCV genotype 6 prevalence, spontaneous clearance and diversity amongst elderly members of the Li ethnic minority in Baisha County, China
The epidemiology of hepatitis C virus varies widely across geographical regions and ethnic groups. Our previous study showed that 6 strains isolated from Baisha County, Hainan Island, China, were all new genotype 6 (gt6) subtypes which differed significantly from subtypes of other regions. In the current study, we conducted a comprehensive epidemiological survey of HCV in the Li ethnic group, native to Baisha County. AntiâHCV antibodies were detected by 2 independent ELISAs in all participants, and positive results confirmed by the recombinant immunoblot assay (RIBA) and HCV RNA viral loads were measured. Univariate chiâsquare test and multivariable logistic regression analyses were used to determine the risk factors for HCV infection and spontaneous clearance rates. Indeterminate RIBA results were excluded or included in analyses; consequently, findings were expressed as a range. Direct sequencing of partial regions within NS5B and E1 was employed for genotyping. Among 1682 participants, 117 to 153 were antiâHCV positive (7.0%â9.1%), with 42.7%â52.6% confirmed to have cleared infection. AntiâHCV positivity was associated with older age (âĽ60 years) (OR = 0.02, 95% CI 0.01â0.05, P < 0.01) and surgery (OR = 2.75, 95% CI 1.36â5.57, P < 0.01), with no significant difference found between the HCV infection group and the HCV spontaneous clearance group. The gt6 subtype distribution characteristics of Baisha County were unique, complex and diverse. The sequences did not cluster with known gt6 subtypes but formed 4 Baisha communityâspecific groups. HCV infection in members of the Li minority ethnic group is characterized by high prevalence rates in the elderly, high spontaneous clearance rates and broad gt6 diversity
Manganese causes neurotoxic iron accumulation via translational repression of Amyloid Precursor Protein (APP) and H-Ferritin
For more than 150 years, it is known that occupational overexposure of manganese (Mn) causes movement disorders resembling Parkinson's disease (PD) and PDâlike syndromes. However, the mechanisms of Mn toxicity are still poorly understood. Here, we demonstrate that Mn doseâ and timeâdependently blocks the protein translation of amyloid precursor protein (APP) and heavyâchain Ferritin (HâFerritin), both iron homeostatic proteins with neuroprotective features. APP and HâFerritin are postâtranscriptionally regulated by iron responsive proteins, which bind to homologous iron responsive elements (IREs) located in the 5â˛âuntranslated regions (5â˛âUTRs) within their mRNA transcripts. Using reporter assays, we demonstrate that Mn exposure repressed the 5â˛âUTRâactivity of APP and HâFerritin, presumably via increased iron responsive proteinsâiron responsive elements binding, ultimately blocking their protein translation. Using two specific Fe2+âspecific probes (RhoNoxâ1 and IPâ1) and ion chromatography inductively coupled plasma mass spectrometry (ICâICPâMS), we show that loss of the protective axis of APP and HâFerritin resulted in unchecked accumulation of redoxâactive ferrous iron (Fe2+) fueling neurotoxic oxidative stress. Enforced APP expression partially attenuated Mnâinduced generation of cellular and lipid reactive oxygen species and neurotoxicity. Lastly, we could validate the Mnâmediated suppression of APP and HâFerritin in two rodent in vivo models (C57BL6/N mice and RjHan:SD rats) mimicking acute and chronic Mn exposure. Together, these results suggest that Mnâinduced neurotoxicity is partly attributable to the translational inhibition of APP and HâFerritin resulting in impaired iron metabolism and exacerbated neurotoxic oxidative stress
Organizational and Inter-Organizational Factors Affecting Aircraft Maintenance Safety in China: A Preliminary Study
The main aim of this research was to explore the organizational and inter-organizational factors affecting aircraft maintenance safety. Specifically it is intended: (a) to probe the categories of organizational factors which effect maintenance safety through the study of an aircraft maintenance organization; and (b) to explore the interface between pilots and maintenance technicians, which is referred to as the information interface due to the exchange of the information between both parties for the safety of flight. The study consisted of 17 interviewees from one aircraft maintenance organization in China, who participated in structured one-on-one interviews. The data were coded using content analysis techniques which could convert the qualitative interview data into quantitative data. Four categories of factors were revealed, including individual and environment, factors relating to the technical systems, non-technical systems, information interface. Results of this research also show that compared to the pilots, the maintenance personnel were less strict with the departure standards for the aircraft (e.g. minimum equipment), which may lead to the conflict between pilots and maintenance personnel
Perceived colleagues' safety knowledge/behavior and safety performance: Safety climate as a moderator in a multilevel study
This study presented a model specifying the relationship of unit-level safety climate and perceived colleagues' safety knowledge/behavior (PCSK/B) to safety behavior (safety compliance and safety participation), as well as safety performance (injuries and near misses). PCSK/B, a measure of descriptive norms, was taken as a new individual-level predictor. Hierarchical linear modeling analyses indicated the significant cross-level interaction effects of unit-level safety climate and PCSK/B on safety behavior, i.e., the more positive the safety climate, the stronger effects PCSK/B has on safety behavior. The effect of PCSK/B on injuries was mediated by safety behavior. Implications for management and safety climate research were discussed. (C) 2009 Elsevier Ltd. All rights reserved
The relationship between safety climate, safety performance and safety-related outcomes: A multilevel study in Chinese management context.
The Interactive Effects of Self-control Demands and Teacher Support on Vocational High School Students' Ego Depletion and Safety Behaviors
Overexpression of LiDXS and LiDXR From Lily (Lilium âSiberiaâ) Enhances the Terpenoid Content in Tobacco Flowers
Lilium, the famous and significant cut flower, emits a variety of volatile organic compounds, which mainly contain monoterpenes, such as myrcene, (E)-β-ocimene, and linalool. To understand the molecular mechanism of monoterpene synthesis in Lilium, we cloned two potential genes in the methylerythritol 4-phosphate pathway, namely LiDXS and LiDXR, from the strong-flavored oriental Lilium âSiberiaâ using a homology-based PCR strategy. The expression levels of LiDXS and LiDXR were consistent with the emission and accumulation of monoterpenes in different floral organs and during the floral development, indicating that these two genes may play key roles in monoterpene synthesis. Subcellular localization demonstrated that LiDXS and LiDXR are expressed in the chloroplasts. Ectopic expression in transgenic tobacco suggested that the flowers of LiDXS and LiDXR transgenic lines accumulated substantially more diterpene, sclareol, compared to the plants transformed with empty vector. Surprisingly, increased content of the monoterpene, linalool and sesquiterpene, caryophyllene, were detected in the LiDXR transgenic lines, whereas the emission of caryophyllene, increased in one of the LiDXS transgenic tobacco lines, indicating that these two genes play significant roles in the synthesis of floral volatiles in the transgenic plants. These results demonstrate that LiDXR can contribute to monoterpene biosynthesis in Lilium âSiberiaâ; however, the role of LiDXS in the biosynthesis of monoterpenes needs further study