Little is known about virus-host cell interactions that regulate the lytic potential of viruses during productive replication. Sindbis virus (SV), a single-stranded positive-sense RNA virus in the alphavirus genus (family Togaviridae), results in lytic infection in most vertebrate cell lines, but persistent productive infection in post-mitotic neurons. The cellular oncogene bcl-2, which encodes an inner mitochondrial membrane protein of M(r) 26,000 (ref. 2), blocks programmed cell death (apoptosis) in neurons. We therefore investigated whether SV infection induces programmed cell death in non-neuronal cells, and if so, whether virus-induced programmed cell death can be blocked by transfection with bcl-2. We demonstrate that SV infection of baby hamster kidney (BHK-2), mouse neuroblastoma (N18), and rat prostatic adenocarcinoma (AT-3) cells results in programmed cell death, whereas SV infection of bcl-2-transfected AT-3 cells results in long-term persistent productive infection. Thus cellular bcl-2 oncogene expression plays a role in the establishment of persistent viral infection by blocking virus-induced programmed cell death.

Over 70% of the present cohort showed adequate knowledge, appropriate attitudes/beliefs and behavior on antibiotic use. Despite a small percent (8%-9%) of respondents reportedly shared and/or self-prescribed antibiotics, this would translate into the practice of half a million people in Hong Kong. Public education programmes should therefore be developed, targeting specific areas of misconceptions, misuse of antibiotic and vulnerable groups at risk of improper use of antibiotics.

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Background/Objective Mental health problems are common among adolescents and greatly influenced by stressful events. This study sought to assess the prevalence and correlates of insomnia, depressive and anxiety symptoms among Chinese adolescents during the COVID-19. Method Cross-sectional study ( N = 1794 adolescents, mean age = 15.26) was conducted in May 2020. An online survey was used to collect socio-demographic data, COVID-related fear (COVID-fear), nutrition, physical activity (PA) level and the symptoms of insomnia, depression and anxiety. Results The prevalence of insomnia, depressive and anxiety symptoms was 37.80%, 48.20% and 36.70%, respectively, among Chinese adolescents during the pandemic. Generalized linear models revealed that female, left behind children, and students with greater COVID-fear tended to report symptoms of insomnia, depression and anxiety concurrently. After adjusting for socio-demographic factors and COVID-fear, better nutritional status and moderately active PA were both associated with lower levels of depressive and anxiety symptoms, while highly active PA was associated with lower levels of insomnia, depressive and anxiety symptoms. Conclusions These findings suggest that more attention should be paid to psychological health among adolescents while combating COVID-19. To promote adolescents’ mental health, educators should help adolescents develop a healthy lifestyle with balanced diet and regular exercise.

MOF-5 is an important metal-organic framework and has been intensely studied, especially in its hydrogen storage properties. In this study, we obtained the interpenetrated MOF-5 materials (MOF-5int) using N,N 0 -dimethylformamide (DMF) or N,N 0 -diethylformamide (DEF) as solvents. The Langmuir surface area of MOF-5-int determined by N 2 adsorption is 950-1100 m 2 g À1 , much lower than the non-penetrated MOF-5 (3000 m 2 g À1 ). However, it can store 1.54-1.82 wt% by volumetric method hydrogen at 77 K and 1 atm, which is higher than the amount stored by the non-penetrated MOF-5. The MOF-5-int was also characterized by XRD-powder diffraction, thermogravimetric analysis (TGA), nitrogen adsorption/desorption analysis, scanning electron microscope (SEM) and X-ray single-crystal structure diffraction. In addition, we found grinding greatly facilitates the decomposition of the MOF-5-int material by H 2 O to a nonporous phase ZnBDC$xH 2 O (within 2-5 min, BDC ¼ 1,4-benzenedicarboxylate), even under low humidity (30%), which calls for careful handling of the MOF-5 material. The effects of the water content, reaction time, reaction temperature, molar ratio of Zn(NO 3 ) 2 to H 2 BDC, addition of H 2 O 2 , rapid stirring and dilution on the synthesis of MOF-5-int were studied and the synthetic conditions were optimized. Moreover, Hafizovic et al. (J. Am. Chem. Soc., 2007, 129, 3612) found the intensity ratio of the powder XRD peak at 9.7 to that at 6.8 (referred to as the R 1 value) of MOF-5 can be used to predict its porosity. The lower the intensity ratio, the more porous it is. In this study, we showed that MOF-5-int can have a very low R 1 value but also a low porosity. The low specific surface area (SSA) is mainly due to its interpenetrated structure instead of the entrapped zinc species or the mesopores in the material, as previously proposed in the literature, and associated with the characteristic, very strong peak at 13.8 in its XRD-powder diffraction pattern. A high R 2 value (the ratio of the intensity of the peak at 13.8 to that at 6.8 ) suggests an interpenetrated structure, especially when the R 1 value is low. In addition, we found that although entrapped ZnO or solvent molecules can increase the R 1 value, and a low R 1 value implies no zinc species or solvent molecules entrapped in the MOF-5 framework, a high R 1 value does not necessarily suggest the presence of entrapped molecules.