Association between daily screen time and risk of stroke among middle-aged and elderly people: research based on China health and nutrition survey.

Background: We aimed to explore the independent associations between screen time and the risk of stroke among Chinese adults based on the China Health and Nutrition Survey (CHNS). Methods: Data on Chinese adults aged older than 40 years from the CHNS in during 2004-2009 were selected. A total of 4,587 individuals were included in 2009, including screen time and the risk of stroke. Simultaneously, we traced the previous screen time to 2004 for those with outcome measures in 2009 (n = 2,100). Basic information, lifestyle, and screen behavior were obtained through face-to-face interviews and self-completed questionnaires. Anthropometric data collected included blood pressure, body weight, height, hip circumference, and waist circumference. Fasting blood was obtained for measurements of lipid and glucose levels. Cross-sectional analysis and cohort analysis were both performed using multivariate logistic regression. Results: Of all participants, 3,004 (65.49%) participants spent more than 2 h per day on screen time. Taking the men who spent less than 2 h on screen per day as reference, the crude odds ratio (OR) of the high risk of stroke was 1.53 [95% confidence interval (CI), 1.20-1.95] for the men who spent 2-3 h per day on screen and 2.37 (95% CI, 1.78-3.16) for the men who spent more than 3 h per day on screen. This difference remained significant after adjusting for confounding factors. No association was observed among women. However, in the cohort analysis with screen time in 2006 as the independent variable, the association between screen time and stroke risk was found both in men [OR, 1.83 (95% CI, 1.19-2.82)] and women [OR, 1.48 (95% CI, 1.10-1.99)]). Conclusion: We found that the high screen time was associated with an increased stroke risk, which was pronounced in men, warranting a universal need to limit screen time in order to improve health.

Farmland boundary extraction based on the AttMobile-DeeplabV3+ network and least squares fitting of straight lines.

The rapid extraction of farmland boundaries is key to implementing autonomous operation of agricultural machinery. This study addresses the issue of incomplete farmland boundary segmentation in existing methods, proposing a method for obtaining farmland boundaries based on unmanned aerial vehicle (UAV) remote sensing images. The method is divided into two steps: boundary image acquisition and boundary line fitting. To acquire the boundary image, an improved semantic segmentation network, AttMobile-DeeplabV3+, is designed. Subsequently, a boundary tracing function is used to track the boundaries of the binary image. Lastly, the least squares method is used to obtain the fitted boundary line. The paper validates the method through experiments on both crop-covered and non-crop-covered farmland. Experimental results show that on crop-covered and non-crop-covered farmland, the network's intersection over union (IoU) is 93.25% and 93.14%, respectively; the pixel accuracy (PA) for crop-covered farmland is 96.62%. The average vertical error and average angular error of the extracted boundary line are 0.039 and 1.473°, respectively. This research provides substantial and accurate data support, offering technical assistance for the positioning and path planning of autonomous agricultural machinery.

Effects of periplocoside T isolated from Periploca sepium on behavior and sensory-CNS-motor circuits in Drosophila melanogaster larvae.

Periplocoside T (PST) from Periploca sepium has insecticidal activity against some lepidopterans, which can significantly inhibit the activity of vacuolar-type H+-ATPases (V-ATPase). V-ATPase is involved in the release of neurotransmitters in vesicles during nerve signal transduction. However, there are actions of PST on behavior and sensory-central nervous system (CNS)-motor neural circuit which are commonly overlooked. After exposure to 500 mg/L PST for 48 h, the difference of the proportion of larvae responding to stimuli in the four Drosophila strains was not significant as compared to controls, but larval mouth hook movement and body wall motion were significantly decreased as compared to controls, and the decrease was more obvious in parats1; DSC1-/- and DSC1-/- strains, especially in parats1; DSC1-/- strain. Compared with control (DMSO), the excitatory junction potential (EJP) frequencies of sensory-CNS-motor circuits in the four Drosophila strains after PST or bafiloymcin A1 (BA1, a V-ATPase specific inhibitor) treatment gradually decreased with time, and the decreasing amplitude of BA1 treatment was greater than that of PST treatment, but both were higher than that of the control. The decay amplitude of EJP frequency in two strains with DSC1 channel knockout was lower than that of w1118 and parats1 strains without DSC1 channel knockout. Thus, the results indicated that PST, similar to BA1, could inhibit the transmission of sensory-CNS-motor circuit excitability of Drosophila larvae by inhibiting the activity of V-ATPase, and DSC1 channel play a role of in regulating the stability of nervous system.

Role of DSC1 in Drosophila melanogaster synaptic activities in response to haedoxan A.

Drosophila sodium channel 1 (DSC1) encodes a voltage-gated divalent cation channel that mediates neuronal excitability in insects. Previous research revealed that DSC1 knockout Drosophila melanogaster conferred different susceptibility to insecticides, which indicated the vital regulation role of DSC1 under insecticide stress. Haedoxan A (HA) is a lignan compound isolated from Phryma leptostachya, and we found that HA has excellent insecticidal activity and is worthy of further study as a botanical insecticide. Herein, we performed bioassay and electrophysiological experiments to test the biological and neural changes in the larval Drosophila with/without DSC1 knockout in response to HA. Bioassay results showed that knockout of DSC1 reduced the sensitivity to HA in both w1118 (a common wild-type strain in the laboratory) and parats1 (a pyrethroid-resistant strain) larvae. Except for parats1 /DSC1-/- , electrophysiology results implicated that HA delayed the decay rate and increased the frequency of miniature excitatory junctional potentials of Drosophila from w1118 , parats1 , and DSC1-/- strains. Moreover, the neuromuscular synapse excitatory activities of parats1 /DSC1-/- larvae were more sensitive to HA than DSC1-/- larvae, which further confirmed the functional contribution of DSC1 to neuronal excitability. Collectively, these results indicated that the DSC1 channel not only regulated the insecticidal activity of HA, but also maintained the stability of neural circuits through functional interaction with voltage-gated sodium channels. Therefore, our study provides useful information for elucidating the regulatory mechanism of DSC1 in the neural system of insects involving the action of HA derived from P. leptostachya.

Structure and function of aldopentose catabolism enzymes involved in oxidative non-phosphorylative pathways.

Platform chemicals and polymer precursors can be produced via enzymatic pathways starting from lignocellulosic waste materials. The hemicellulose fraction of lignocellulose contains aldopentose sugars, such as D-xylose and L-arabinose, which can be enzymatically converted into various biobased products by microbial non-phosphorylated oxidative pathways. The Weimberg and Dahms pathways convert pentose sugars into α-ketoglutarate, or pyruvate and glycolaldehyde, respectively, which then serve as precursors for further conversion into a wide range of industrial products. In this review, we summarize the known three-dimensional structures of the enzymes involved in oxidative non-phosphorylative pathways of pentose catabolism. Key structural features and reaction mechanisms of a diverse set of enzymes responsible for the catalytic steps in the reactions are analysed and discussed.

A novel thermostable aspartic protease from Talaromyces leycettanus and its specific autocatalytic activation through an intermediate transition state.

Aspartic proteases exhibit optimum enzyme activity under acidic conditions and have been extensively used in food, fermentation, and leather industries. In this study, a novel aspartic protease precursor (proTlAPA1) from Talaromyces leycettanus was identified and successfully expressed in Pichia pastoris. Subsequently, the auto-activation processing of the zymogen proTlAPA1 was studied by SDS-PAGE and N-terminal sequencing, under different processing conditions. TlAPA1 shared the highest identity of 70.3% with the aspartic endopeptidase from Byssochlamys spectabilis (GAD91729) and was classified into a new subgroup of the aspartic protease A1 family, based on evolutionary analysis. Mature TlAPA1 protein displayed an optimal activity at 60 °C and remained stable at temperatures of 55 °C and below, indicating the thermostable nature of TlAPA1 aspartic protease. During the auto-activation processing of proTlAPA1, a 45-kDa intermediate was identified that divided the processing mechanism into two steps: formation of intermediates and activation of the mature protein (TlAPA1). The former step can be processed without proteolytic activity, while the latter process depended on protease activity completely. The discovery of the novel aspartic protease TlAPA1 and the study of its activation process will contribute to a better understanding of the mechanism of aspartic protease auto-activation.

Improving the catalytic performance of Proteinase K from Parengyodontium album for use in feather degradation.

Proteinase K (PROK) from Parengyodontium album hydrolyzes keratin, a major protein component of poultry feathers, which are an inexpensive and renewable protein resource. Based on structural studies for analysis of amino acid flexibility near the catalytic center, identification of highly conserved residues, and experimental screening, we obtained a mutant R218S with residual activity 1.6-fold higher than that of PROK after incubation at 60 °C for 1 h. Molecular dynamics simulation indicated that substitution of Arg218 with Ser leads to three hydrogen bonds being introduced into the structure, stabilizing the ß-sheet in which Ser218 is located, and thus improvement of thermostability. Additionally, the mutant R218S had a 15% increase in specific activity compared to PROK and improvement in the rate and thoroughness of feather degradation compared with PROK. We confirmed the positive effects of enhancing catalytic center rigidity on enzyme thermostability, a finding which may have broad applications.

Effect of Sodium Oleate on the Adsorption Morphology and Mechanism of Nanobubbles on the Mica Surface.

Nanobubbles promote the flotation of fine-grained minerals. In the associated mechanism, the aggregation of fine particles is first promoted, which increases the probability of collision between particles and bubbles. However, the interaction between nanobubbles and mineral particles is often neglected, especially when the surface properties of the nanobubbles are modified by flotation collectors. In this study, the interaction mechanism between nanobubbles and the mica surface is investigated by nanoparticle tracking analysis, zeta potential measurement, and atomic force microscopy. The results reveal that the hydrophobic group of sodium oleate points toward the inside of the nanobubble and the hydrophilic group faces outward after the interaction of sodium oleate molecules and nanobubbles. A surfactant micelle with nanobubbles as the core is formed, thus considerably reducing the concentration of sodium oleate to form micelles. The adsorption of the modified nanobubbles on the mineral surface is carried out by the specific adsorption of the exposed hydrophilic group and the mineral surface. This adsorption method is superior to the hydrophobic interaction between the nanobubbles and the hydrophobic mineral surface. Further, the nanobubbles are highly selective for the activation sites on the mineral surface in the adsorption mode. This study will help understand the interaction between nanobubbles and collectors to further apply nanobubbles to treat fine-grained mineral particles.

High-throughput amplicon sequencing demonstrates extensive diversity of xylanase genes in the sediment of soda lake Dabusu.

OBJECTIVE: To explore the diversity of glycoside hydrolase family 10 xylanase genes in the sediment of soda lake Dabusu by using high-throughput amplicon sequencing based on the Illumina HiSeq2500 platform. RESULTS: A total of 227,420 clean reads, representing approximately 49.5 M bp, were obtained. Operational taxonomic unit (OTU) classification, with a 95% sequence identity cut-off, resulted in 467 OTUs with 392 annotated as GH10 xylanase, exhibiting 35-99% protein sequence identity with their closest-related xylanases in GenBank. Above 75% of the total OTUs demonstrated less than 80% identity with known xylanases. In addition, xylanases derived from the sediment were found to be affiliated to 12 different phyla, with Bacteroidetes, Proteobacteria, Actinobacteria, Firmicutes, Verrucomicrobia, and Basidiomycota being the dominant phyla. Moreover, barcode sequence had a major effect on abundance with only a minor effect on diversity. CONCLUSIONS: High-throughput amplicon sequencing offers insight into xylanase gene diversity at a substantially higher resolution and lesser cost than library cloning and Sanger sequencing, facilitating a more thorough understanding of xylanase distribution and ecology.

High-level expression and characterization of a novel aspartic protease from Talaromyces leycettanus JCM12802 and its potential application in juice clarification.

Aspartic proteases are promising fining agents used in the production of fruit juices. In this study, a novel aspartic protease gene (Tlap) was identified in Talaromyces leycettanus JCM12802 and heterologously expressed in Pichia pastoris. Using casein as the substrate, purified recombinant TlAP showed optimal activities at pH 3.0 and 55 °C with a specific activity of 1795.4 ±â€¯62.8 U/mg, and remained stable over a pH range of 3.0-6.0 and at temperatures of 45 °C and below. Moreover, the enzyme was highly resistant to most metal ions and chemical reagents except for Fe3+ and ß-mercaptoethanol. When added to apple, orange, grape and kiwi fruit juice, it showed excellent proteolytic activity against haze-forming proteins, decreasing the turbidity by up to 49.9 nephelometry turbidity units (NTU). These favorable enzymatic properties make TlAP attractive for potential use in the juice industry.

Novel Salt-Tolerant Xylanase from a Mangrove-Isolated Fungus Phoma sp. MF13 and Its Application in Chinese Steamed Bread.

A novel glycosyl hydrolase family 11 xylanase gene, xynMF13A, was cloned from Phoma sp. MF13, a xylanase-producing fungus isolated from mangrove sediment. xynMF13A was heterologously expressed in Pichia pastoris, and the recombinant XynMF13A (rXynMF13A) was purified by Ni-affinity chromatography. The temperature and pH optima of purified rXynMF13A were 45 °C and pH 5.0, respectively. rXynMF13A showed a high level of salt tolerance, with maximal enzyme activity being seen at 0.5 M NaCl and as much as 53% of maximal activity at 4 M NaCl. The major rXynMF13A hydrolysis products from corncob xylan were xylobiose, xylotriose, xylotetraose, and xylopentaose, but no xylose was found. These hydrolysis products suggest an important potential for XynMF13A in the production of xylooligosaccharides (XOs). Furthermore, rXynMF13A had beneficial effects on Chinese steamed bread production, by increasing specific volume and elasticity while decreasing hardness and chewiness. These results demonstrate XynMF13A to be a novel xylanase with potentially significant applications in baking, XOs production, and seafood processing.

Exploratory study on resilience and its influencing factors among hospital nurses in Guangzhou, China.

BACKGROUND: Currently, building resilience in nurses is recognized as an important factor that helps maintain their health and stay in their profession; thus, identifying which factors can help them build resilience is necessary. METHODS: A cross-sectional survey design was used, and 1356 nurses from 11 general hospitals in Guangzhou, China, were assessed using the Chinese version of the Conner-Davidson Resilience Scale, the General Self-Efficacy Scale, the Simplified Coping Style Questionnaire, and the Job Stress Scale of Chinese nurses. The demographic characteristics of participants were also gathered. RESULTS: The mean total score of nurses' resilience is 59.99 (SD 13.59), which was significantly lower (P < 0.001) than that of the general people in China. The regression analysis affirmed that the factors which influence the resilience of nurses include self-efficacy, coping style, job stress, and education level (R 2 = 49.4%, P < 0.001). CONCLUSION: Nurses had low resilience. They could not effectively cope with job challenges and recover from adversity. Strengthening self-efficacy, choosing active coping, decreasing job stress, and enhancing educational training can effectively improve their resilience.