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Accurate analysis of technological innovation mechanism in different regions is the key to promoting China’s technological innovation, economic transformation and upgrading. This paper collected statistical data of high-tech enterprises in 27 provinces in China from 2009 to 2016, established a novel PSO-GRNN model, and applied sensitivity analysis to explore the influencing factors and regional differences of enterprise technological innovation in Eastern, Central and Western China. The empirical results showed that the influencing factors were innovation investment, market environment, government support and foreign technology spillover sorting by impact size. Innovation investment was the decisive factor of technological innovation, but innovation resources mainly concentrated on Eastern China, severely insufficient in Central and Western China. Market environment was favorable to Eastern and Central China, but unfavorable to Western China, which restricted greatly the development of Western China. The principalagent problem of state-owned enterprise and the crowding out effect of government research and development funds jointly led to the negative influence of government support on technological innovation. Foreign technology spillover had significant positive effects on technological innovation in Western China. This paper clarifies some disputes about influencing factors of technological innovation and provides a new research perspective for related issues. First published online 27 May 2021

Air contamination is identified with individuals’ wellbeing and furthermore affects the sustainable development of economy and society. This paper gathered the time series data of seven meteorological conditions variables of Beijing city from 1 November 2013 to 31 October 2017 and utilized the generalized regression neural network optimized by the particle swarm optimization algorithm (PSO-GRNN) to explore seasonal disparity in the impacts of mean atmospheric humidity, maximum wind velocity, insolation duration, mean wind velocity and rain precipitation on air quality index (AQI). The results showed that in general, the most significant impacting factor on air quality in Beijing is insolation duration, mean atmospheric humidity, and maximum wind velocity. In spring and autumn, the meteorological diffusion conditions represented by insolation duration and mean atmospheric humidity had a significant effect on air quality. In summer, temperature and wind are the most significant variables influencing air quality in Beijing; the most important reason for air contamination in Beijing in winter is the increase in air humidity and the deterioration of air diffusion condition. This study investigates the seasonal effects of meteorological conditions on air contamination and suggests a new research method for air quality research. In future studies, the impacts of different variables other than meteorological conditions on air quality should be assessed.

To reduce the gas disaster of high gas coal seam and improve the efficiency of gas extraction by high drilling, the layout parameters of drilling holes in Pingdingshan coal mine are optimized. Based on the analysis and calculation of the \"three zones\" of the movement towards the overly strata of No.10 coal in Pingdingshan coal mine, the height of caving zone and fissure zone in 24,130 working face are 10.06–14.46 m and 38.75–49.95 m respectively. The elevation angle, azimuth angle and the length of high-level boreholes are studied and analyzed by COMSOL numerical simulation software. The simulation results show that the optimum layout parameters of high-level boreholes are as follows: The elevation angle of borehole should be controlled at 9°–12°, the azimuth angle should be 30°–45°, and the length of borehole should be 150 m. Then the optimum layout parameters of high-level boreholes are determined for engineering application of 24,130 working face. Borehole data onto actual mine show that the optimum layout parameters of high-level boreholes were elevation angle between 8°and 11°, azimuth angle between 30° and 42°, and length of boreholes between 145 and 155 m. The simulation results are basically consistent with the measured data. The maximum gas concentration in working face, upper corner and return air roadway is stably controlled below 1%. The safe mining of 24,130 working face is ensured, which provided a certain reference value of gas control in the goaf of Pingdingshan mine and adjacent mines.

In this work, we studied a novel algae cultivation strategy, mixotrophic microalgae biofilm, to improve the productivity and cost-efficiency of algal biofuel production. In contrast to previous methods, this improved approach can achieve high productivity at low cost by harnessing the benefits of mixotrophic growth’s high efficiency, i.e., capable of subsisting on inorganic and organic carbons thus unaffected by limited light, and microalgae biofilm’s low harvesting cost. Our results, as one of the first studies of this type, proved that microalgae biofilms under mixotrophic condition exhibited significantly higher productivity and quality of biofuel feedstock: 2–3 times higher of biomass yield, 2–10 times higher of lipid accumulation, and 40–60% lower of ash content when compared to microalgae biofilms under autotrophic condition. In addition, we investigated the impact of cell-surface properties (hydrophobicity and roughness) on the growth activities of microalgae biofilms and found that the productivity of mixotrophic biofilms was significantly correlated with the surface hydrophobicity. Finally, our work demonstrated the applicability of integrating this novel cultivation method with wastewater for maximum efficiency. This study opens a new possibility to solve the long-lasting challenges of algal biofuel feedstock production, i.e., low productivity and high cost of algal cultivation.

To investigate the non-linear relationship between diabetes mellitus (DM) duration and the development of diabetic retinopathy (DR). By investigating the association between these variables, our goal is to contribute to the existing knowledge regarding the impact of DM duration on the development and severity of DR. A retrospective cross-sectional study was conducted on 420 patients in the Department of Endocrinology at Guangdong Provincial People’s Hospital, who had undergone ophthalmic consultations from December 2017 to November 2018. The analysis of DM duration and DR utilized a generalized additive model to identify both linear and non-linear connections. The threshold effect was determined using a two-piece regression model. The study included a total of 420 patients, with a mean age of 58.7 years. Of these, 56.9% (239/420) were male. The prevalence of DR was 38.33% (161/420). After adjusting for confounding factors, a nonlinear relationship between DM duration and DR was observed, with a turning point at 8 years. On the left side of the turning point, the prevalence increased by 24% per 1-year increase in DM duration ( OR : 1.24; 95% CI : 1.11–1.38; P <0.0001). However, no statistically significant differences were found on the right side of the turning point ( OR : 1.02; 95% CI : 0.97–1.08; P  = 0.4987). Our study identified a non-linear relationship between DM duration and DR in patients. When the DM duration is less than 8 years, a positive correlation exists between DM duration and DR. However, once the DM duration exceeds 8 years, the effect reaches saturation, and no significant correlation is observed.

Unlike inorganic crystals, metal-organic frameworks do not have a well-developed nanostructure library, and establishing their appropriately diverse and complex architectures remains a major challenge. Here, we demonstrate a general route to control metal-organic framework structure by a solvent-assisted ligand exchange approach. Thirteen different types of metal-organic framework structures have been prepared successfully. To demonstrate a proof of concept application, we used the obtained metal-organic framework materials as precursors for synthesizing nanoporous carbons and investigated their electrochemical Na + storage properties. Due to the unique architecture, the one-dimensional nanoporous carbon derived from double-shelled ZnCo bimetallic zeolitic imidazolate framework nanotubes exhibits high specific capacity as well as superior rate capability and cycling stability. Our study offers an avenue for the controllable preparation of well-designed meta-organic framework structures and their derivatives, which would further broaden the application opportunities of metal-organic framework materials. Metal-organic frameworks are promising for a range of applications, but architectural control is challenging. Here the authors use solvent-assisted ligand exchange to access a variety of metal-organic framework nanomaterials for precursors of nanoporous carbon with sodium ion storage properties.

Analysis of the changes of microorganisms during Chinese Feng-flavor Daqu fermentation, and the specific contribution of different environmental factors to Daqu microorganisms. High throughput sequencing technology and SourceTracker software were used to analyze the microbial diversity of Feng-flavor Daqu before and after fermentation. 85 fungal and 105 bacterial were detected in the newly pressed Feng-flavor Daqu, while 33 fungal and 50 bacterial in the mature Daqu, and 202 fungal and 555 bacterial in the environmental samples. After fermentation, the microbial community structure of Daqu changed and decreased significantly. 94.7% of fungi come from raw materials and 1.8% from outdoor ground, 60.95% of bacteria come from indoor ground, 20.44% from raw materials, and 8.98% from tools. By comparing the changes of microorganisms in Daqu before and after fermentation, the microorganisms in mature Daqu may mainly come from not only the enhanced strains but also the environment.The source of main microorganisms in Feng-flavor Daqu and the influence of environmental factors on the quality of Daqu were clarified, which provided a basis for improving the quality of Feng-flavor Daqu.

Munc13-1 is a large multifunctional protein essential for synaptic vesicle fusion and neurotransmitter release. Its dysfunction has been linked to many neurological disorders. Evidence suggests that the MUN domain of Munc13-1 collaborates with Munc18-1 to initiate SNARE assembly, thereby priming vesicles for fast calcium-triggered vesicle fusion. The underlying molecular mechanism, however, is poorly understood. Recently, it was found that Munc18-1 catalyzes neuronal SNARE assembly through an obligate template complex intermediate containing Munc18-1 and 2 SNARE proteins—syntaxin 1 and VAMP2. Here, using single-molecule force spectroscopy, we discovered that the MUN domain of Munc13-1 stabilizes the template complex by ∼2.1 kBT. The MUN-bound template complex enhances SNAP-25 binding to the templated SNAREs and subsequent full SNARE assembly. Mutational studies suggest that the MUN-bound template complex is functionally important for SNARE assembly and neurotransmitter release. Taken together, our observations provide a potential molecular mechanism by which Munc13-1 and Munc18-1 cooperatively chaperone SNARE folding and assembly, thereby regulating synaptic vesicle fusion.

IntroductionIn order to solve the current situation of water shortage and achieve sustainable agricultural development, micro-sprinkler water-saving irrigation is one of the effective methods to improve water use efficiency (WUE) compared with flood irrigation. However, the effects of water content on wheat grain weight and plant hormone content under micro-sprinkler water-saving irrigation, and the potential mechanism of different water content on plant hormone-mediated grain grouting under micro-sprinkler water-saving irrigation are still largely unknown.MethodsTherefore, this study conducted extensive monitoring of wheat grain weight and plant hormone content under different water content in a typical winter wheat field (wheat) in the North China Plain from 2019 to 2021 by 13C isotope tracer technology through a field experiment based on micro-sprinkling water-saving irrigation.ResultsThe results showed that under micro-sprinkler water saving irrigation, the lateral development of wheat roots after anthesis was promoted by W3 treatment in the deep soil depth (0-60 cm), which was the basis for efficient absorption of water and fertilizer, as well as efficient formation of photosynthate. Meanwhile, W3 treatment significantly promoted the transfer of photosynthetic products from leaves, stems and sheaths to grain. Compared with other treatments, W3 treatment significantly increased the average grain filling rate and grain filling time. Compared with W1, W2 and W5 treatments, W3 and W4 treatments significantly improved the number of grains per ear, 1000 grain weight and grain yield. From the perspective of water saving, W3 treatment had the highest effect. Compared with W1, W2 and W5 treatments, W3 treatment significantly increased the average grain yield of the two seasons by 19.69%, 6.30% and 8.07%, respectively.DiscussionIn this study, optimizing micro-sprinkler water saving irrigation can improve root development, promote photosynthetic product transport, and increase average grain filling rate and grain filling time, thereby increasing grain yield.This study provides valuable insights into improving sustainable wheat production in micro-water-saving irrigation agricultural cropping systems, and it may provide a practical framework for striking a balance between groundwater protection and food security.

Scholars have proposed the practice of split nitrogen fertilizer application (SNFA), which has proven to be an effective approach for enhancing nitrogen use efficiency. However, the combined effects of SNFA on wheat plant nitrogen use efficiency, ammonia (NH 3 ) emission flux, as well as the rates of nitrification and denitrification in different ecosystems remain unclear. Meanwhile, few studies have sought to understand the effects of the split nitrogen fertilizer method under water-saving irrigation technology conditions on nitrogen loss. The current study assessed soil NH 3 volatilization, nitrification, and denitrification intensities, as well as the abundance of nitrogen cycle-related functional genes following application of different treatments. Specifically, we applied a nitrogen rate of 240 kg⋅ha –1 , and the following fertilizer ratios of the percent base to that of topdressing under water-saving irrigation: N1 (basal/dressing, 100/0%), N2 (basal/dressing, 70/30%), N3 (basal/dressing, 50/50%), N4 (basal/dressing, 30/70%), and N5 (basal/dressing, 0/100%). N3 treatment significantly reduced NH 3 volatilization, nitrification, and denitrification intensities, primarily owing to the reduced reaction substrate concentration (NO 3 – and NH 4 + ) and abundance of functional genes involved in the nitrogen cycle ( amoA- AOB, nirK , and nirS ) within the wheat-land soil. 15 N tracer studies further demonstrated that N3 treatments significantly increased the grain nitrogen accumulation by 9.50–28.27% compared with that under other treatments. This increase was primarily due to an increase in the amount of nitrogen absorbed by wheat from soil and fertilizers, which was caused by an enhancement in total nitrogen uptake (7.2–21.81%). Overall, N3 treatment (basal/dressing, 50/50%) was found to effectively reduce nitrogen loss through NH 3 volatilization, nitrification and denitrification while improving nitrogen uptake by wheat. Thus, its application will serve to further maximize the yield and provide a fertilization practice that will facilitate cleaner wheat production in the North China Plain.