Analysis of vibrational dynamics in cell-substrate interactions using nanopipette electrochemical sensors.

Cell-substrate interaction plays a critical role in determining the mechanical status of living cell membrane. Changes of substrate surface properties can significantly alter the cell mechanical microenvironment, leading to mechanical changes of cell membrane. However, it is still difficult to accurately quantify the influence of the substrate surface properties on the mechanical status of living cell membrane without damage. This study addresses the challenge by using an electrochemical sensor made from an ultrasmall quartz nanopipette. With the tip diameter less than 100 nm, the nanopipette-based sensor achieves highly sensitive, noninvasive and label-free monitoring of the mechanical status of single living cells by collecting stable cyclic membrane oscillatory signals from continuous current versus time traces. The electrochemical signals collected from PC12 cells cultured on three different substrates (bare ITO (indium tin oxides) glass, hydroxyl modified ITO glass, amino modified ITO glass) indicate that the microenvironment more favorable for cell adhesion can increase the membrane stiffness. This work provides a label-free electrochemical approach to accurately quantify the mechanical status of single living cells in real-time, which may help to better understand the relationship between the cell membrane and the extra cellular matrix.

Construction of yield loss indicators for cold vortex, light-temperature-water combined stress during the flowering period of rice in Northeast China.

The construction of a yield loss evaluation index for the cold vortex type light-temperature-water composite adversity during rice flowering period in Northeast China is important for elucidating the impacts of cold vortex type composite disasters on rice yield loss in middle and high latitude areas. Moreover, it can provide meteorological support to ensure safe production of high-quality japonica rice in China and contribute to regional disaster reduction and efficiency improvement. By combining growth period data, meteorological data, and yield data, we delineated and constructed the composite stress occurrence index of cold vortex type light-temperature-water at the flowering stage of japonica. We analyzed the relationship between factors causing disasters and yield structure, as well as the relationship between different yield structures and yield by employing BP neural network method. We further dissected the processes involved in the causation of combined disasters. Based on the K-means clustering method and historical typical disaster years, we quantified the critical thresholds and disaster grades, and established an evaluation index and model for assessing yield loss caused by combined stress from cold vortex type light-temperature-water. Finally, we examined the spatial and temporal variations of low temperature, abundant rainfall, and reduced sunlight during the flowering period in the three provinces of Northeast China. Results showed that the critical thresholds for light, temperature, and water stress index during the flowering stage of mild, moderate, and severe cold vortex types were [0, 0.21), [0.21, 0.32), and [0.32, 0.64], respectively. The rates of yield loss were [0, 0.03), [0.03, 0.08), and [0.08, 0.096], respectively. Based on the verification results of a total of 751 samples in 11 random years from 1961 to 2020, the percentage of stations for which the production reduction grade, as calculated by the composite index developed in this study, aligning with the actual production reduction grade was 63.7%, consistently exceeding 58.0% annually. Moreover, the proportion of sites with a similarity or difference level of 1 stood at 88.3%, surpassing 85.0% in each year. The index could effectively assess the extent of rice yield loss caused by cold vortex disasters in Northeast China.

Nanoconfined Electrokinetic Chromatography (NEC): Gradient Separation and Sensing of Short DNA Fragments at the Single-Molecule Level.

Glass nanopipets have been demonstrated to be a powerful tool for the sensing and discrimination of biomolecules, such as DNA strands with different lengths or configurations. Despite progress made in nanopipet-based sensors, it remains challenging to develop effective strategies that separate and sense in one operation. In this study, we demonstrate an agarose gel-filled nanopipet that enables hyphenated length-dependent separation and electrochemical sensing of short DNA fragments based on the electrokinetic flow of DNA molecules in the nanoconfined channel at the tip of the nanopipet. This nanoconfined electrokinetic chromatography (NEC) method is used to distinguish the mixture of DNA strands without labels, and the ionic current signals measured in real time show that the mixed DNA strands pass through the tip hole in order according to the molecular weight. With NEC, gradient separation and electrochemical measurement of biomolecules can be achieved simultaneously at the single-molecule level, which is further applied for programmable gene delivery into single living cells. Overall, NEC provides a multipurpose platform integrating separation, sensing, single-cell delivery, and manipulation, which may bring new insights into advanced bioapplication.

Effect of lactic acid bacteria on the structure and potential function of the microbial community of Nongxiangxing Daqu.

OBJECTIVES: The microbial community structure of the saccharifying starter, Nongxiangxing Daqu(Daqu), is a crucial factor in determining Baijiu's quality. Lactic acid bacteria (LAB), are the dominant microorganisms in the Daqu. The present study investigated the effects of LAB on the microbial community structure and its contribution to microbial community function during the fermentation of Daqu. METHODS: The effect of LAB on the structure and function of the microbial community of Daqu was investigated using high-throughput sequencing technology combined with multivariate statistical analysis. RESULTS: LAB showed a significant stage-specific evolution pattern during Daqu fermentation. The LEfSe analysis and the random forest learning algorithm identified LAB as vital differential microorganisms during Daqu fermentation. The correlation co-occurrence network showed aggregation of LAB and Daqu microorganisms, indicating LAB's significant position in influencing the microbial community structure, and suggests that LAB showed negative correlations with Bacillus, Saccharopolyspora, and Thermoactinomyces but positive correlations with Issatchenkia, Candida, Acetobacter, and Gluconobacter. The predicted genes of LAB enriched 20 functional pathways during Daqu fermentation, including Biosynthesis of amino acids, Alanine, aspartate and glutamate metabolism, Valine, leucine and isoleucine biosynthesis and Starch and sucrose metabolism, which suggested that LAB had the functions of polysaccharide metabolism and amino acid biosynthesis. CONCLUSION: LAB are important in determining the composition and function of Daqu microorganisms, and LAB are closely related to the production of nitrogenous flavor substances in Daqu. The study provides a foundation for further exploring the function of LAB and the regulation of Daqu quality.

Chilling injury monitoring and intensity identification of dryland maize in Heilongjiang.

BACKGROUND: Accurate and timely access to large-scale crop damage information provides an essential reference for responding to agricultural disaster prevention and mitigation needs and ensuring food production security. The present study aimed to reveal the new characteristics of low-temperature cold damage to maize in the context of climate warming. Heilongjiang, one of the provinces with the highest latitude, the most significant climate change and the largest maize production in China, was taken as the study area. We combined meteorological stations and MODIS remote sensing data to spatially identify the occurrence and intensity of cold damage to maize based on the growing season temperature distance level index, as well as to assess the extent of cold damage. RESULTS: The main findings are: (i) The frequency and intensity range of cold damage in the growing season (May to September) in Heilongjiang Province from 1991 to 2020 against climate warming showed a decreasing trend. The average temperature from 1991 to 2000 was 17.777 °C, with seven occurrences of maize cold damage years, of which 5 years comprised widespread cold damage and 2 years comprised regional cold damage. The average temperature from 2000 to 2010 was 18.137 °C, with cold damage three times, of which 2 years comprised regional cold damage and 1 year comprised widespread cold damage. The average temperature from 2010 to 2020 was 18.130 °C, with one maize cold damage year occurring, which comprised regional cold damage. The frequency of maize chilling injury decreased significantly from 1991 to 2020, from 0.23 in 1991-2000 to 0.1 in 2000-2010 and, finally, to 0.03 in 2010-2020. (ii) The good consistency between MODIS_LST data and temperature data from meteorological stations suggests that MODIS_LST data can be used to build a temperature remote sensing estimation model for spatially extensive cold damage monitoring and intensity discrimination. (iii) Taking 2009 as an example of a large-scale cold damage year, the spatial discrimination of maize cold damage intensity shows that the spatial distribution of chilling injury intensity has no obvious geographical features. The intensity of cold damage was mainly mild cold damage. According to administrative regions, the scope of chilling injury was the largest in Mudanjiang City, Heihe City, and Jixi City, accounting for 91.56%, 86.25%, and 84.91%, respectively. The areas with the most extensive range of severe chilling injuries were the Great Khingan Mountains region, Heihe City, Mudanjiang City, Yichun City, and Jixi City. CONCLUSION: In the context of climate warming, the frequency and intensity range of maize cold damage showed a decreasing trend from 1991 to 2020 in Heilongjiang Province. The results of cold damage identification based on MODIS_LST data are accurate and can improve the spatial accuracy. The results of the present study provide a reference and guidance for dealing with the occurrence and defence of spatially refined cold damage. © 2023 Society of Chemical Industry.

Distribution characteristics of climate potential productivity of soybean in frigid region and its response to climate change.

The scope of this study is to analyze the climatic potential productivity of soybean [Glycine max (L.) Merr.] and explore the impact of climate change on soybean in the frigid region in China by using daily climatic variables from 144 meteorological stations for the period 1971‒2019. The gradually descending model is used to estimate photosynthesis, light-temperature, and climatic potential productivity of soybean. The results show that climate potential productivity of soybean in the frigid region ranges from large to small: Liaoning > Jilin > Heilongjiang > East Four Leagues (four cities in eastern Inner Mongolia), with Heilongjiang and East Four Leagues showing a significant upward trend. Spatially, the climate potential productivity is larger on plains than that on mountains. The Northeast Plain and Sanjiang Plain are areas with high climate potential productivity. Changes in climatic factors have different impacts on the climate potential productivity of soybean. The influence of temperature changes on the climate potential productivity shows a positive effect, and climate warming compensates for the lack of heat in the frigid region. Furthermore, radiation and precipitation are the main climatic factors leading to spatial differences in the climate potential productivity of soybean in the frigid region. Radiation changes have a positive effect on soybean climate potential productivity in plain areas and a negative effect on the mountains. However, precipitation reduction negatively affects most of the frigid region, while it has a positive effect on the two plains of Heilongjiang. Precipitation responses the needs of soybean growth. Our findings recommend that a transition of soybean planting from the mountainous region to plain, that is, from low potential productivity areas to high potential productivity areas, could be an effective strategy for regional optimization for planting structure and rational utilization of irrigation technology.

Cancer Mortality and Long-Term Environmental Exposure of Cadmium in Contaminated Community Based on a Third Retrospective Cause of Death Investigation of Residents Living in the Guangdong Province from 2004 to 2005.

This study compared the temporal and geographic trends of cancer in China with a specific focus on the long-term exposure to soil cadmium (Cd) pollution. The geographic information system (GIS; kriging interpolation method) was used to detect the Cd contained in the soil from the Dabaoshan area, Guangdong Province. The standard rate ratio (SRR) was calculated to describe the relationship between Cd exposure and cancer mortality risk using the low-exposure group as a reference. Eight hundred six cancer deaths (533 male and 273 female) in the total population of 972,970 were identified, and the age-standardized rate (world) was 145.64 per 100,000. Significant dose-response relationships were found using the low-exposure group as the reference group. The Cd soil levels were positively associated with the cancer mortality risk in the community population, particularly for all cancers (SRR = 3.27; 95% CI = 2.42-4.55), esophageal cancer (SRR = 5.42; 95% CI = 1.07-30.56), stomach cancer (SRR = 5.99; 95% CI = 2.00-18.66), liver cancer (SRR = 4.45; 95% CI = 2.16-10.34), and lung cancer (SRR = 2.86; 95% CI = 1.62-5.31) for the total population. Additionally, similar results were obtained when using the 2000 China standard population. Cd exposure significantly affected the standardized mortality rates (China) by age group for all cancers, esophageal cancer, stomach cancer, liver cancer, and lung cancer in the total population, particularly in the age groups of 35-54, 55-74, and ≥ 75 years, respectively. Cd soil level is likely positively associated with increased cancer mortality of all cancer types and esophageal, stomach, liver, and lung cancers but not for other specific categories of cancer.

[Time-series characteristics of drought and flood in spring soybean growing season and its effect on soybean yield in Heilongjiang Province, China]. / é»‘é¾™æ±Ÿçœå¤§è±†ç”Ÿé•¿å­£æ—±æ¶æ—¶åºç‰¹å¾åŠå ¶å¯¹äº§é‡çš„å½±å“.

Under the background of climate change, the spatial-temporal distribution of precipita-tion in Heilongjiang Province is uneven, and drought and flood frequently change, which is not conducive to the safety of soybean production for the province. To clarify the influence mechanism of drought and flood in the growing season on soybean yield in Heilongjiang Province, we analyzed the time-series characteristics of drought and flood in soybean growing season and its effect on soybean yield in different growth stages, based on data of daily precipitation from 60 meteorological stations during 1961 to 2018 and soybean yield in the same period, with the standardized precipitation index (SPI) as the drought and flood evaluation index. The results showed that, from 1961 to 2018, the influence range of drought in soybean growing season in Heilongjiang Province showed a weak decreasing trend, while that of flood showed a weak increasing trend. In the same period, the intensity of both drought and flood showed a weak increasing trend, with slightly stronger role of flood intensity. The probability of the co-occurrence of drought and flood accounted for 60.3%. The soybean growing season in Heilongjiang Province may become wetter. From 2012 to 2018, the influence range and occurrence intensity of flood were significantly higher than that of drought, six years of the whole or regional flood occurred, in which five years were moderate degrees. The effects of drought and flood on soybean yield differed across regions in soybean growing season. The effect of flood on soybean yield was significantly stronger than that of drought in the Northwest, North and East, and were similar in the Midland, while in the Southwest, South and Southeast, the effect of drought was much greater than that of flood. The fluctuation of soybean yield was closely related to drought and flood during bloom-seed-filling period. Among them, in the Northwest, Southwest, Midland, South and Southeast of Heilongjiang, soybean yield would reach a high level when there was a little bit more precipitation, but the moderate and above-moderate levels of flood would cause the reduction. In the North, the fluctuation of soybean yield was mainly affected by flood, while in the East, the effects of drought and flood on soybean yield were similar.

The relationship between long-term exposure to PM2.5 and fasting plasma glucose levels in Chinese children and adolescents aged 6-17 years: A national cross-sectional study.

BACKGROUND: Previous studies investigating the association between PM2.5 exposure and fasting plasma glucose levels (FPGLs) are mostly limited to short- and mid-term PM2.5 exposure and lack adjustments for key confounders in adult research. OBJECTIVES: Exploring the relationship between seven years long-term PM2.5 exposure and FPGLs in Chinese children and adolescents aged 6-17 years. METHODS: Between September 2013 and December 2013, 16,489 participants aged 6-17 years were recruited using a four-staged, stratified, cluster sampling strategy from 7 provinces, autonomous regions and municipalities of mainland China. A generalized linear mixed model (GLMM) was used to estimate the relationship between annual PM2.5 exposure (2007-2013) and FPGLs stratified by sex and one-year age increments. Sociodemographic characteristics, living with both parents, early-life factors, behaviours, and infection symptoms were gradually adjusted from the crude model to regression model 6, and BMI was adjusted for in model 7. RESULTS: The annual concentration of PM2.5 was 56.23 (±12.99) µg/m3. The mean FPGLs in the 8551 boys (4.75 mmol/L ± 0.52) was significantly higher than that in the 8194 girls (4.63 mmol/L ± 0.48) (P < 0.0001). In model 6, for every 10 µg/m3 increase in PM2.5 exposure, the FPGLs in boys and girls increased by 0.048 (95% CIs 0.031 to 0.065) mmol/L (P < 0.0001) and 0.054 (95% CIs 0.039 to 0.069) mmol/L (P < 0.0001), respectively. The FPGLs were significantly positively associated with long-term PM2.5 exposure at the ages of 12, 15 and 16 years in both the boys and girls and exhibited age differences in model 7. The prevalence of impaired fasting plasma glucose (IFP) and diabetes decreased by 0.8% when the exposure concentration of PM2.5 was reduced by 10 µg/m3 in model 6, which assessed the negative effects of PM2.5 exposure and revealed that 1,298,920 children and adolescents could have been protected from IFP and diabetes in 2013 in China. CONCLUSIONS: Long-term PM2.5 exposure may be an independent risk factor of elevated FPGLs. The adverse effect of PM2.5 exposure on FPGLs in children and adolescents could appear after 10 years of cumulative exposure. The precise intervention time was revealed as approximately 12 and 11 years in boys and girls, respectively. There are great public health implications associated with early prevention strategies for the eradication of the negative effects of long-term exposure to PM2.5 on FPGLs.

Complete Genome Sequence of the Poly-γ-Glutamate-Synthesizing Bacterium Bacillus subtilis Bs-115.

Bacillus subtilis Bs-115 was isolated from the soil of a corn field in Yutai County, Jinan City, Shandong Province, People's Republic of China, and is characterized by the efficient synthesis of poly-γ-glutamate (γ-PGA), with corn saccharification liquid as the sole energy and carbon source during the process of γ-PGA formation. Here, we report the complete genome sequence of Bacillus subtilis Bs-115 and the genes associated with poly-γ-glutamate synthesis.

[Optimization of fuel ethanol production from kitchen waste by Plackett-Burman design].

Kitchen garbage was chosen to produce ethanol through simultaneous saccharification and fermentation (SSF) by Zymomonas mobilis. Plackett-Burman design was employed to screen affecting parameters during SSF process. The parameters were divided into two parts, enzymes and nutritions. None of the nutritions added showed significant effect during the experiment, which demonstrated that the kitchen garbage could meet the requirement of the microorganism without extra supplementation. Protease and glucoamylase were determined to be affecting factors for ethanol production. Single factor experiment showed that the optimum usage of these two enzymes were both 100 U/g and the corresponding maximum ethanol was determined to be 53 g/L. The ethanol yield could be as high as 44%. The utilization of kitchen garbage to produce ethanol could reduce threaten of waste as well as improve the protein content of the spent. This method could save the ethanol production cost and benefit for the recycle of kitchen garbage.

[The development of FSCLZLY--an ascites-ultrafiltration instrument].

It's known to all that the refractory ascites treatment has so far been a very difficult clinical problem. We have extracted much experience from the practical techniques used in the refractory ascites treatments of more than 1,000 cases, and have developed the ascites ultrafiltration & concentration therapeutic instrument--FSCLZLY-A. The clinical applications show that it is very effective. Its effective rate is about 72.08%. Therefore, it is a very useful and important medical device for refractory ascites, for the improvement of renal function, and for the prevention of the infection of abdominal cavity.