Length limitation of astral microtubules orients cell divisions in murine intestinal crypts.

Planar spindle orientation is critical for epithelial tissue organization and is generally instructed by the long cell-shape axis or cortical polarity domains. We introduced mouse intestinal organoids in order to study spindle orientation in a monolayered mammalian epithelium. Although spindles were planar, mitotic cells remained elongated along the apico-basal (A-B) axis, and polarity complexes were segregated to basal poles, so that spindles oriented in an unconventional manner, orthogonal to both polarity and geometric cues. Using high-resolution 3D imaging, simulations, and cell-shape and cytoskeleton manipulations, we show that planar divisions resulted from a length limitation in astral microtubules (MTs) which precludes them from interacting with basal polarity, and orient spindles from the local geometry of apical domains. Accordingly, lengthening MTs affected spindle planarity, cell positioning, and crypt arrangement. We conclude that MT length regulation may serve as a key mechanism for spindles to sense local cell shapes and tissue forces to preserve mammalian epithelial architecture.

Chitosan-driven biocompatible hydrogel based on water-soluble polypyrrole for stable human-machine interfaces.

Recently, wearable hydrogel sensors based on polypyrrole have shown considerable promise in the realms of human-machine interfaces. However, because of the water insolubility of pyrrole and polypyrrole, the preparation of polypyrrole conductive hydrogels with comprehensive properties by a simplified method remains a great challenge. Herein, the water-soluble polypyrrole was synthesized and the conformal CxPy conductive hydrogels were fabricated by the strategy of one-pot method of introducing chitosan and water-soluble polypyrrole into acrylamide matrix containing cucurbit[7]uril. The hydrogel exhibited good mechanical strength (215.48 kPa at the fracture strain of 2149.17 %), superior adhesion strength (~51.54 kPa), excellent conductivity (0.534 S m-1) and biocompatibility (The cell viability of NIH3T3 is 98.25 %). As a strain sensor, C10P5 hydrogel exhibited excellent stability during 1000 times cycles, which is suitable for epidermal sensors to monitor body motions and physiological signals. Therefore, the chitosan-driven conductive hydrogel would present prosperous prospects in the fields of human-machine interfaces.

Prevalence of cardiovascular risk factors clustering among suburban residents in Beijing, China.

BACKGROUND: The prevalence of cardiovascular risk factors (CRFs) has been increasing in urbanization areas of China. The article aims to estimate the up-to-date prevalence and clustering of major modifiable CRFs among suburban residents in Beijing. METHODS: A cross-sectional survey in a representative sample of 16371 suburban residents aged 35 to 74 years was carried out in 2007, and results were compared with counterparts of China and the United States. Data was collected by questionnaires, blood pressure, anthropometric, and laboratory measurements. RESULTS: The age-standardized prevalence of investigated major CRFs (overweight/obesity, diabetes, hypertension, dyslipidemia, and current smoking) in the study was 36.2%, 6.5%, 36.9%, 35.4%, and 36.3%, respectively. Overall, 83.5%, 47.2% and 17.5% of participants in the study had ≥1, ≥2, and ≥3 major CRFs, which were higher than total China (80.5%, 45.9%, and 17.2%) and lower than the United State (93.1%, 73.0% and 35.9%), respectively. The adjusted odds ratio (95% confidence interval) of ≥1, ≥2, and ≥3 CRFs for men compared with women was 3.4 (3.0 to 3.9), 4.3 (3.7 to 5.0), and 5.4 (4.6 to 6.5), respectively. In addition, older age groups were more likely to have ≥1, ≥2, and ≥3 of these modifiable cardiovascular risk factors compared with younger age groups, respectively. CONCLUSIONS: High prevalence and clustering of major modifiable CRFs are commonly present in suburban residents in Beijing. More effective population-based interventions, such as smoking cessation, healthy diet, increased physical activity are required to reduce the prevalence of these CRFs and the increasing burden of cardiovascular diseases in China.