Many encapsulated bacteria use capsules to cause invasive diseases. However, it remains largely unknown how the capsules enhance bacterial virulence under in vivo infection conditions. Here we show that the capsules primarily target the liver to enhance bacterial survival at the onset of blood-borne infections. In a mouse sepsis model, the capsules enabled human pathogens Streptococcus pneumoniae and Escherichia coli to circumvent the recognition of liver-resident macrophage Kupffer cells (KCs) in a capsular serotype-dependent manner. In contrast to effective capture of acapsular bacteria by KCs, the encapsulated bacteria are partially (low-virulence types) or completely (high-virulence types) “untouchable” for KCs. We finally identified the asialoglycoprotein receptor (ASGR) as the first known capsule receptor on KCs to recognize the low-virulence serotype-7F and -14 pneumococcal capsules. Our data identify the molecular interplay between the capsules and KCs as a master controller of the fate and virulence of encapsulated bacteria, and suggest that the interplay is targetable for therapeutic control of septic infections.

Purpose Knowledge sharing, as a kind of social behavior that incorporates collective intelligence to achieve a certain goal, has become a remarkable developing trend in recent years. Under the context of traditional teaching, this study aims to explore the manner in which students become effective in sharing knowledge to help optimize course design and improve our existing education. Design/methodology/approach Among 195 university students taking an elective, the effects of different incentives on group performance in completing tasks is explored on the basis of a randomized experiment. Findings Results show that intra-group cooperation can be helpful to student performance, whereas intra-group competition neither improves nor worsens student performance. The former is mainly driven by reciprocity, especially for that stimulated by inter-group competition, whereas the latter is stimulated by egoism. Thus, proper reciprocity can promote student behavior to increase voluntary contribution. In addition, intra-group differences do not interfere with group performance, especially task-oriented groups. Originality/value Certain suggestions are proposed to improve the curriculum design in large classrooms. Forming groups is the best way to strengthen student knowledge sharing. Within task-oriented groups, the incentives of inter-group competition can encourage students to deepen intra-group cooperation and thus effectively improve group performance under the conditions of external competition.

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Background The alcohol consumption pattern, alcoholic liver disease (ALD) prevalence and related risk factors among alcohol drinkers in Beijing haven’t been fully elucidated. Hence, a cross-sectional study was conducted to investigate potential link among these factors. Methods A two-stage stratified cluster sampling was carried out in Beijing. All participants were 25 years of age or older, possessed with medical insurance, and lived in Beijing for over 6 months. As part for this investigation, participants were asked to answer a questionnaire and undergo physical examination. The questionnaire included demographic information, alcohol intake, and medical history. The physical examination included physical and Fibrotouch tests. Moreover, 10 ml blood sample was collected from each subject to examine liver functions, perform routine blood, Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV). Results Overall, 74,988 residents participated in our study. The proportion of current drinkers among all participants was 46.10%. The differences in gender, region, age group, education, annual household income, and occupation among lifetime abstainers, former drinkers, non-weekly and weekly drinkers were significantly different (P<0.05). The ethanol intake between men and women, people living in urban and rural regions were significantly different (P<0.05). Strong spirits were commonly consumed by men, whereas, beers were commonly consumed by women. Drinking strong spirits generally lead to liver steatosis. In addition, ALD prevalence was 1.30% in participants over 25 years old. The differences in ALD prevalence between men and women, and among different age groups, were significant (P<0.05). Based on our analysis, ALD risk factors in Beijing included: gender (male), age (older than 35 years), high waist circumference, high blood pressure, high BMI, high blood sugar level, and being heavy drinkers. Conclusion Compared with other cities or regions in China, the level of alcohol consumption in Beijing is at an upper middle level. But the ALD prevalence is low likely because ethanol intake is relatively low. Our analysis revealed that heavy drinking is a major risk factor for ALD development. Hence, if alcohol consumption is unavoidable, we caution against heavy drinking.

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