SARS-CoV-2 rapidly spreads among humans via social networks, with social mixing and network characteristics potentially facilitating transmission. However, limited data on topological structural features has hindered in-depth studies. Existing research is based on snapshot analyses, preventing temporal investigations of network changes. Comparing network characteristics over time offers additional insights into transmission dynamics. We examined confirmed COVID-19 patients from an eastern Chinese province, analyzing social mixing and network characteristics using transmission network topology before and after widespread interventions. Between the two time periods, the percentage of singleton networks increased from 38.9$ \% $ to 62.8$ \% $$ (p<0.001) $; the average shortest path length decreased from 1.53 to 1.14 $ (p<0.001) $; the average betweenness reduced from 0.65 to 0.11$ (p<0.001) $; the average cluster size dropped from 4.05 to 2.72 $ (p=0.004) $; and the out-degree had a slight but nonsignificant decline from 0.75 to 0.63 $ (p=0.099). $ Results show that nonpharmaceutical interventions effectively disrupted transmission networks, preventing further disease spread. Additionally, we found that the networks’ dynamic structure provided more information than solely examining infection curves after applying descriptive and agent-based modeling approaches. In summary, we investigated social mixing and network characteristics of COVID-19 patients during different pandemic stages, revealing transmission network heterogeneities.

Paediatric Mycoplasma pneumoniae pneumonia (MPP) is a major cause of community-acquired pneumonia in China. Data on epidemiology of paediatric MPP from China are little known. This study retrospectively collected data from June 2006 to June 2016 in Beijing Children's Hospital, Capital Medical University of North China and aims to explore the epidemiological features of paediatric MPP and severe MPP (SMPP) in North China during the past 10 years. A total of 27 498 paediatric patients with pneumonia were enrolled. Among them, 37.5% of paediatric patients had MPP. In this area, an epidemic took place every 2–3 years at the peak, and the positive rate of MPP increased during these peak years over time. The peak age of MPP was between the ages of 6 and 10 years, accounting for 75.2%, significantly more compared with other age groups (χ2 = 1384.1, P < 0.0001). The epidemics peaked in September, October and November (χ2 = 904.9, P < 0.0001). Additionally, 13.0% of MPP paediatric patients were SMPP, but over time, the rate of SMPP increased, reaching 42.6% in 2016. The mean age of paediatric patients with SMPP (6.7 ± 3.0 years old) was younger than that of patients with non-SMPP (7.4 ± 3.2 years old) (t = 3.60, P = 0.0001). The prevalence of MPP and SMPP is common in China, especially in children from 6 to 10 years old. Paediatric patients with SMPP tend to be younger than those with non-SMPP. MPP outbreaks occur every 2–3 years in North China. September, October and November are the peak months, unlike in South China. Understanding the epidemiological characteristics of paediatric MPP can contribute to timely treatment and diagnosis, and may improve the prognosis of children with SMPP.

Crack propagation behaviors in a precracked single crystal Ag under mode I loading at different temperatures are studied by molecular dynamics simulation. The simulation results show that the crack propagation behaviors are sensitive to external temperature. At 0 K, the crack propagates in a brittle manner. Crack tip blunting and void generation are first observed followed by void growth and linkage with the main crack, which lead to the propagation of the main crack and brittle failure immediately without any microstructure evolution. As the temperature gets higher, more void nucleations and dislocation emissions occur in the crack propagation process. The deformation of the single crystal Ag can be considered as plastic deformation due to dislocation emissions. The crack propagation dynamics characterizing the microstructure evolution of atoms around the crack tip is also shown. Finally, it is shown that the stress of the single crystal Ag changes with the crack length synchronously.

Background: This study examined the use of low doses of antipsychotic medications (300 mg/day CPZeq or less) in older Asian patients with schizophrenia and its demographic and clinical correlates.

Methods: Information on hospitalized patients with schizophrenia, aged 55 years or older, was extracted from the database of the Research on Asian Psychotropic Prescription Patterns (REAP) study (2001–2009). Data on 1,452 patients in eight Asian countries and territories including China, Hong Kong, Japan, Korea, Singapore, Taiwan, India, and Malaysia were analyzed. Sociodemographic and clinical characteristics and antipsychotic prescriptions were recorded using a standardized protocol and data collection procedure.

Results: The prescription frequency for low doses of antipsychotic medications was 40.9% in the pooled sample. Multiple logistic regression analysis of the whole sample showed that patients on low doses of antipsychotic medications were more likely to be female, have an older age, a shorter length of illness, and less positive symptoms. Of patients in the six countries and territories that participated in all the surveys between 2001 and 2009, those in Japan were less likely to receive low doses of antipsychotics.

Conclusion: Low doses of antipsychotic medications were only applied in less than half of older Asian patients with schizophrenia.

We test the hypothesis of increasing prevalence of low-dose antipsychotic use (⩽300 mg/d chlorpromazine-equivalent) in East Asia and examine clinical correlates of conservative dosing. Rates of low-dose antipsychotic prescription were determined for 4535 patients with DSM-IV diagnosis of schizophrenia in six East Asian countries and territories, with comparisons analysed for 2004 vs. 2001. Between 2001 (n=2399 subjects) and 2004 (n=2136 subjects), prescription rates for low doses of antipsychotic drugs (APDs) increased from 24.8% to 44.0% (p<0.001). Low doses were more likely among older patients (p=0.005), during first-lifetime hospitalizations (p<0.001), and among patients with less prominent delusions, hallucinations or disorganized speech (all p<0.05). Multivariate modelling indicated that low doses were strongly associated with older age, first admission, sampling year (2004>2001), less use of antipsychotic polytherapy (all p<0.001) and depot antipsychotics (p=0.009). Conservative dosing of APDs was increasingly prevalent in East Asia. Our findings suggest characteristics of patients who may be particularly likely to require low antipsychotic doses.

Nine prepubertal gilts (JunMu No. 1) were randomly allocated into three groups (n=3) and fed with a high-energy diet (Group H), a low-energy diet (Group L), or a moderate-energy diet (Group M) for 14 days. Free access to water was provided throughout the research period. Ovaries and uteri were collected after the energy treatments, and processed for determination of the absolute quantities of insulin-like growth factor receptor (IGF-1R) and epidermal growth factor receptor (EGFR) mRNA, using real-time polymerase chain reaction (PCR). The expression of IGF-1R and EGFR mRNA in ovaries and uteri was significantly ranked as: Group H>Group M>Group L (P<0.05). This result suggests that high energy intake markedly enhanced the ovarian and uterine expression of IGF-1R and EGFR in prepubertal gilts, whereas insufficient energy intake markedly inhibited such expression. IGF-1R and EGFR may be involved in mediating the effects of energy intake on the development of the reproductive system in prepubertal gilts.

To identify Porcine haemagglutinating encephalomyelitis virus (HEV) 67N receptor in porcine kidney (PK) cell membranes, the S1 protein of HEV was expressed in Pichia pastoris and purified by Ni2+ affinity chromatograph. Polyclonal antibodies to HEV were prepared by immunizing rabbits by injecting the purified S1 protein four times. After SDS–polyacrylamide gel electrophoresis (SDS–PAGE), the PK cell membrane proteins were transferred on to nitrocellulose membrane. A virus overlay protein binding assay (VOPBA) was performed using the recombinant S1 protein to identify the protein binding receptor, HEV-S1. The result showed that HEV-S1 protein bound to one band (about 90 kDa) in PK cell membranes. This result is very important for the study of the pathogenic mechanism of HEV.

Background. This is the first study to examine variation across cohorts in lifetime risk of DSM-IV mental disorders in metropolitan China.

Method. Face-to-face household interviews of 2633 adults in Beijing and 2568 adults in Shanghai were conducted from November 2001 to February 2002 using a multi-stage household probability sampling method. The Chinese World Mental Health (WMH) Survey Initiative version of the WHO Composite International Diagnostic Interview (WMH-CIDI) was used for assessment.

Results. Lifetime prevalence of any disorder was 13·2%. Alcohol abuse (4·7%), major depressive disorder (3·5%), and specific phobia (2·6%) were the most common disorders. The median age of onset was later for mood (43 years) than anxiety (17 years) and substance use (25 years) disorders. Compared to observed lifetime prevalence, the projected lifetime risk as of age 75 years increased by 106% for major depressive disorder (7·2%), and was uniformly higher for all disorders. Relative odds of any lifetime disorder were 4·7 in the most recent cohorts (ages 18–34) compared to the eldest cohorts (ages [ges ]65).

Conclusions. The findings of this cross-sectional study tally with the view that rapid socioeconomic changes may bring about increasing incidence of mental disorders in China. However, prospective longitudinal studies are needed to confirm if the increase is real. Because of the huge size of the Chinese population, any increase in projected lifetime risk of mental disorders represents an enormous increase in the number of affected individuals.

Background. Psychiatric epidemiological surveys in China have repeatedly found much lower prevalence estimates than in most other parts of the world.

Method. Face-to-face household interviews of 5201 subjects (2633 in Beijing and 2568 in Shanghai respectively) were conducted from November 2001 to February 2002 using a multistage household probability sampling method. A Chinese version of the World Health Organization Composite International Diagnostic Interview (CIDI) was used for assessment.

Results. Twelve-month prevalence of any DSM-IV mental disorder in metropolitan China is estimated to be 7·0%, with major depressive disorder (2·0%), specific phobia (1·9%), and intermittent explosive disorder (1·7%) the most common disorders. Of these, 13·9% are classified as serious, 32·6% moderate, and 53·5% mild. Only 3·4% of respondents with any disorder sought treatment within the previous 12 months.

Conclusions. Although the general pattern of disorders, risk factors, and unmet need for treatment are similar to those in other countries, a low prevalence of mental disorders is found in metropolitan China. Resolving methodological problems that cause downward bias in estimates, such as stigma-related under-reporting and diagnostic incongruity with a somatopsychic mode of symptom presentation may lead to more accurate and probably higher prevalence estimates in future epidemiological studies. As a low prevalence still translates into an enormous number of people in China, measures are urgently needed to address the huge unmet need for treatment of mental disorders.