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We evaluated the individual and combined effects of salinity and alkalinity on gill Na+/K+-ATPase enzyme activity, plasma ion concentration, and osmotic pressure in Luciobarbus capito. Increasing salinity concentrations (5, 8, 11, and 14 g/L) were associated with an initial increase and then decrease in L. capito gill Na+/K+-ATPase activity. Activity was affected by the difference between internal and external Na+ ion concentrations and osmotic pressure (P<0.05). Both plasma ion (Na+, K+, and Cl−) concentration and osmotic pressure increased significantly (P<0.05). An increase in alkalinity (15, 30, 45, and 60 mM) caused a significant increase in plasma K+ and urea nitrogen concentrations (P<0.05) but had no effect on either plasma osmotic pressure or gill filament ATPase activity. In the two-factor experiment, the saline-alkaline interaction caused a significant increase in plasma ion (Na+, Cl−, and urea nitrogen) and osmotic pressure (P<0.05). Variance analysis revealed that salinity, alkalinity, and their interaction significantly affected osmotic pressure, with salinity being most affected, followed by alkalinity, and their interaction. Gill filament ATPase activity increased at first and then decreased; peak values were observed in the orthogonal experiment group at a salinity of 8 g/L and alkalinity of 30 mM. [ABSTRACT FROM AUTHOR]

Nanofluids that are produced by dispersing nanoparticles into traditional heat transfer fluids, show greater thermal conductivities than regular fluids. An interfacial nano-shell between the nanoparticle and the base fluid was used to derive an expression for the effective thermal conductivity of nanofluids. Unlike with traditional models, the effective thermal conductivity predicted by the present model is not only affected by the ratio of the thermal conductivities of the particle and the media and their relative volume fractions, but is also affected by the nanoparticle radius and the thermal conductivity and thickness of the interfacial nano-shell. The calculated results predicted by this model agree quite well with available experimental data. [ABSTRACT FROM AUTHOR]

Summary: Objectives: Injection drug use is a major route of HIV transmission in China, yet relatively little is known about why so few injection drug users utilize free HIV testing services. This study aimed to examine barriers to HIV testing and voluntary counseling and testing (VCT) service utilization among injection drug users in Shanghai, China. Methods: Utilizing mixed methods, we analyzed data from a survey of 540 compulsory drug abuse treatment patients and data from focus groups with 70 service providers and patients. Results: Only 24.4% of patients expressed willingness to be tested for HIV. Willingness to be tested was associated with younger age and more positive attitudes towards condom use. Patients reported several barriers to utilization of voluntary HIV testing services, including lack of information about these services, perceptions of no risk or low-risk for HIV infection, fear of positive results, and the stigma or discrimination that may be experienced by the patient or their family. Having limited skills related to HIV counseling was reported by service providers as the primary barrier to encouraging patients to utilize HIV testing/VCT services. Conclusions: Special intervention programs targeting injection drug users, their family members, and service providers may increase HIV testing in China. [Copyright &y& Elsevier]