RESUMO
Vanadium oxides have aroused attention as cathode materials in aqueous zinc-ion batteries (AZIBs) due to their low cost and high safety. However, low ion diffusion and vanadium dissolution often lead to capacity decay and deteriorating stability during cycling. Herein, vanadium dioxides (VO2) nanobelts are coated with a single-atom cobalt dispersed N-doped carbon (Co-N-C) layer via a facile calcination strategy to form Co-N-C layer coated VO2 nanobelts (VO2@Co-N-C NBs) for cathodes in AZIBs. Various in-/ex situ characterizations demonstrate the interfaces between VO2 layers and Co-N-C layers can protect the VO2 NBs from collapsing, increase ion diffusion, and enhance the Zn2+ storage performance. Additional density functional theory (DFT) simulations demonstrate that CoâOâV bonds between VO2 and Co-N-C layers can enhance interfacial Zn2+ storage. Moreover, the VO2@Co-N-C NBs provided an ultrahigh capacity (418.7 mAh g-1 at 1 A g-1), outstanding long-term stability (over 8000 cycles at 20 A g-1), and superior rate performance.
RESUMO
The objectives of the study were to estimate the prevalence of anti-hepatitis C virus (HCV) positivity among blood donors from Chengdu, China, and to determine risk factors associated with infection. In this study, data were collected from volunteer blood donors between July 2006 and June 2007. Anti-HCV test was performed in 119,518 donors. To identify risk factors associated with HCV infections a case-control study was conducted in 305 unique HCV-seropositive blood donors and 610 seronegative donors matched for age and sex. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression. The population attributable risk (PAR) to risk factor was estimated according to the Bruzzi's formula. The prevalence of anti-HCV positivity was 0.53% (95% CI: 0.489-0.572%). The final multivariate model included the following independent HCV risk factors: razor sharing (OR=29.16; 95% CI: 12.89-66.00), blood transfusion (OR=20.84; 95% CI: 3.76-115.45), acupuncture (OR=8.01; 95% CI: 3.16-20.30), a history of hospitalization, injections >10 years earlier, a family history of hepatitis B, dental treatment, and ear piercing. The PAR of risk factors are 68.4%, 6.3%, 14.1%, 23.1%, 29.5%, 29.3%, 38.9%, and 27.8%, respectively, and the total PAR is 98.3%. Infection with HCV among blood donors in Chengdu is associated with iatrogenic risk factors and beauty treatment-related risk. Razor sharing is an important risk factor for HCV infection. These results indicate that infection control measures in healthcare settings may reduce the burden of HCV infection and there is a need for development of effective educational programs to improve HCV knowledge among beauty culture professionals, barber cosmetologists, and the general public to avoid risk behaviors.
Assuntos
Doadores de Sangue , Anticorpos Anti-Hepatite C/sangue , Hepatite C/epidemiologia , Hepatite C/virologia , Adolescente , Adulto , Estudos de Casos e Controles , China/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Estudos Soroepidemiológicos , Adulto JovemRESUMO
OBJECTIVE: To discuss the coding of full dentition with 32 locations and measure the characteristics of some bony indexes in occlusal-facial digital radiology (DR). METHODS: To select randomly three hundred DR orthopantomogram and code the full dentition, then analyze the diversity of dental patterns. To select randomly one hundred DR lateral cephalogram and measure six indexes (N-S,N-Me,Cd-Gn,Cd-Go,NP-SN,MP-SN) separately by one odontologist and one trained forensic graduate student, then calculate the coefficient variation (CV) of every index and take a correlation analysis for the consistency between two measurements. RESULTS: (1) The total diversity of 300 dental patterns was 75%.It was a very high value. (2)All six quantitative variables had comparatively high CV value.(3) After the linear correlation analysis between two measurements, all six coefficient correlations were close to 1. This indicated that the measurements were stable and consistent. CONCLUSION: The method of coding full dentition in DR orthopantomogram and measuring six bony indexes in DR lateral cephalogram can be used to forensic identification.