Evolution of Digital Health and Exploration of Patented Technologies (2017-2021): Bibliometric Analysis.

BACKGROUND: The significant impact of digital health emerged prominently during the COVID-19 pandemic. Despite this, there is a paucity of bibliometric analyses focusing on technologies within the field of digital health patents. Patents offer a wealth of insights into technologies, commercial prospects, and competitive landscapes, often undisclosed in other publications. Given the rapid evolution of the digital health industry, safeguarding algorithms, software, and advanced surgical devices through patent systems is imperative. The patent system simultaneously acts as a valuable repository of technological knowledge, accessible to researchers. This accessibility facilitates the enhancement of existing technologies and the advancement of medical equipment, ultimately contributing to public health improvement and meeting public demands. OBJECTIVE: The primary objective of this study is to gain a more profound understanding of technology hotspots and development trends within the field of digital health. METHODS: Using a bibliometric analysis methodology, we assessed the global technological output reflected in patents on digital health published between 2017 and 2021. Using Citespace5.1R8 and Excel 2016, we conducted bibliometric visualization and comparative analyses of key metrics, including national contributions, institutional affiliations, inventor profiles, and technology topics. RESULTS: A total of 15,763 digital health patents were identified as published between 2017 and 2021. The China National Intellectual Property Administration secured the top position with 7253 published patents, whereas Koninklijke Philips emerged as the leading institution with 329 patents. Notably, Assaf Govari emerged as the most prolific inventor. Technology hot spots encompassed categories such as "Medical Equipment and Information Systems," "Image Analysis," and "Electrical Diagnosis," classified by Derwent Manual Code. A patent related to the technique of receiving and transmitting data through microchips garnered the highest citation, attributed to the patentee Covidien LP. CONCLUSIONS: The trajectory of digital health patents has been growing since 2017, primarily propelled by China, the United States, and Japan. Applications in health interventions and enhancements in surgical devices represent the predominant scenarios for digital health technology. Algorithms emerged as the pivotal technologies protected by patents, whereas techniques related to data transfer, storage, and exchange in the digital health domain are anticipated to be focal points in forthcoming basic research.

Changes in seminal plasma microecological dynamics and the mechanistic impact of core metabolite hexadecanamide in asthenozoospermia patients.

Asthenozoospermia (AZS) is a prevalent contributor to male infertility, characterized by a substantial decline in sperm motility. In recent years, large-scale studies have explored the interplay between the male reproductive system's microecology and its implications for reproductive health. Nevertheless, the direct association between seminal microecology and male infertility pathogenesis remains inconclusive. This study used 16S rDNA sequencing and multi-omics analysis to conduct a comprehensive investigation of the seminal microbial community and metabolites in AZS patients. Patients were categorized into four distinct groups: Normal, mild AZS (AZS-I), moderate AZS (AZS-II), and severe AZS (AZS-III). Microbiome differential abundance analysis revealed significant differences in microbial composition and metabolite profiles within the seminal plasma of these groups. Subsequently, patients were classified into a control group (Normal and AZS-I) and an AZS group (AZS-II and AZS-III). Correlation and cross-reference analyses identified distinct microbial genera and metabolites. Notably, the AZS group exhibited a reduced abundance of bacterial genera such as Pseudomonas, Serratia, and Methylobacterium-Methylorubrum in seminal plasma, positively correlating with core differential metabolite (hexadecanamide). Conversely, the AZS group displayed an increased abundance of bacterial genera such as Uruburuella, Vibrio, and Pseudoalteromonas, with a negative correlation with core differential metabolite (hexadecanamide). In vitro and in vivo experiments validated that hexadecanamide significantly enhanced sperm motility. Using predictive metabolite-targeting gene analysis and single-cell transcriptome sequencing, we profiled the gene expression of candidate target genes PAOX and CA2. Protein immunoblotting techniques validated the upregulation protein levels of PAOX and CA2 in sperm samples after hexadecanamide treatment, enhancing sperm motility. In conclusion, this study uncovered a significant correlation between six microbial genera in seminal plasma and the content of the metabolite hexadecanamide, which is related to AZS. Hexadecanamide notably enhances sperm motility, suggesting its potential integration into clinical strategies for managing AZS, providing a foundational framework for diagnostic and therapeutic advancements.

Deoxyuridine-rich cytoplasmic DNA antagonizes STING-dependent innate immune responses and sensitizes resistant tumors to anti-PD-L1 therapy.

DNA damage and cytoplasmic DNA induce type-1 interferon (IFN-1) and potentiate responses to immune checkpoint inhibitors. Our prior work found that inhibitors of the DNA damage response kinase ATR (ATRi) induce IFN-1 and deoxyuridine (dU) incorporation by DNA polymerases, akin to antimetabolites. Whether and how dU incorporation is required for ATRi-induced IFN-1 signaling is not known. Here, we show that ATRi-dependent IFN-1 responses require uracil DNA glycosylase (UNG)-initiated base excision repair and STING. Quantitative analyses of nine distinct nucleosides reveals that ATRi induce dU incorporation more rapidly in UNG wild-type than knockout cells, and that induction of IFN-1 is associated with futile cycles of repair. While ATRi induce similar numbers of micronuclei in UNG wild-type and knockout cells, dU containing micronuclei and cytoplasmic DNA are increased in knockout cells. Surprisingly, DNA fragments containing dU block STING-dependent induction of IFN-1, MHC-1, and PD-L1. Furthermore, UNG knockout sensitizes cells to IFN-γ in vitro , and potentiates responses to anti-PD-L1 in resistant tumors in vivo . These data demonstrate an unexpected and specific role for dU-rich DNA in suppressing STING-dependent IFN-1 responses, and show that UNG-deficient tumors have a heightened response to immune checkpoint inhibitors. STATEMENT OF SIGNIFICANCE: Antimetabolites disrupt nucleotide pools and increase dU incorporation by DNA polymerases. We show that unrepaired dU potentiates responses to checkpoint inhibitors in mouse models of cancer. Patients with low tumor UNG may respond to antimetabolites combined with checkpoint inhibitors, and patients with high tumor UNG may respond to UNG inhibitors combined with checkpoint inhibitors.

Pseudotargeted lipidomics analysis of scoparone on glycerophospholipid metabolism in non-alcoholic steatohepatitis mice by LC-MRM-MS.

As the inflammatory subtype of nonalcoholic fatty liver disease (NAFLD), the progression of nonalcoholic steatohepatitis (NASH) is associated with disorders of glycerophospholipid metabolism. Scoparone is the major bioactive component in Artemisia capillaris which has been widely used to treat NASH in traditional Chinese medicine. However, the underlying mechanisms of scoparone against NASH are not yet fully understood, which hinders the development of effective therapeutic agents for NASH. Given the crucial role of glycerophospholipid metabolism in NASH progression, this study aimed to characterize the differential expression of glycerophospholipids that is responsible for scoparone's pharmacological effects and assess its efficacy against NASH. Liquid chromatography-multiple reaction monitoring-mass spectrometry (LC-MRM-MS) was performed to get the concentrations of glycerophospholipids, clarify mechanisms of disease, and highlight insights into drug discovery. Additionally, pathologic findings also presented consistent changes in high-fat diet-induced NASH model, and after scoparone treatment, both the levels of glycerophospholipids and histopathology were similar to normal levels, indicating a beneficial effect during the observation time. Altogether, these results refined the insights on the mechanisms of scoparone against NASH and suggested a route to relieve NASH with glycerophospholipid metabolism. In addition, the current work demonstrated that a pseudotargeted lipidomic platform provided a novel insight into the potential mechanism of scoparone action.

The therapeutic effect of a novel GAPDH inhibitor in mouse model of breast cancer and efficacy monitoring by molecular imaging.

BACKGROUND: Breast cancer is a serious threat to women's health with high morbidity and mortality. The development of more effective therapies for the treatment of breast cancer is strongly warranted. Growing evidence suggests that targeting glucose metabolism may be a promising cancer treatment strategy. We previously identified a new glyceraldehyde-3-phosphate dehydrogenase (GAPDH) inhibitor, DC-5163, which shows great potential in inhibiting tumor growth. Here, we evaluated the anticancer potential of DC-5163 in breast cancer cells. METHODS: The effects of DC-5163 on breast cancer cells were investigated in vitro and in vivo. Seahorse, glucose uptake, lactate production, and cellular ATP content assays were performed to examine the impact of DC-5163 on cellular glycolysis. Cell viability, colony-forming ability, cell cycle, and apoptosis were assessed by CCK8 assay, colony formation assay, flow cytometry, and immunoblotting respectively. The anticancer activity of DC-5163 in vivo was evaluated in a mouse breast cancer xenograft model. RESULTS: DC-5163 suppressed aerobic glycolysis and reduced energy supply of breast cancer cells, thereby inhibiting breast cancer cell growth, inducing cell cycle arrest in the G0/G1 phase, and increasing apoptosis. The therapeutic efficacy was assessed using a breast cancer xenograft mouse model. DC-5163 treatment markedly suppressed tumor growth in vivo without inducing evident systemic toxicity. Micro-PET/CT scans revealed a notable reduction in tumor 18F-FDG and 18F-FLT uptake in the DC-5163 treatment group compared to the DMSO control group. CONCLUSIONS: Our results suggest that DC-5163 is a promising GAPDH inhibitor for suppressing breast cancer growth without obvious side effects. 18F-FDG and 18F-FLT PET/CT can noninvasively assess the levels of glycolysis and proliferation in tumors following treatment with DC-5163.

Characterization of an imported HIV-1 A1/A7/G recombinant in China.

BACKGROUND: International migration has accelerated the HIV-1 spread across national borders, gradually reducing the restrictions on the geographical distribution of HIV-1 subtypes. Subtypes A and G are globally recognized as the third and sixth most dominant HIV-1 genotypes, mainly prevalent in Africa, but rarely detected in China. Here we reported an imported HIV-1 recombinant which was composed of sub-subtypes A1 and A7 of subtype A and subtype G genes in a Chinese female. This virus was the first HIV-1 recombinant including A7 genes reported in the world. CASE PRESENTATION: The near full-length genome (NFLG) was obtained from the plasma sample of the female in an HIV-1 molecular epidemiological survey with 853 participants in China. Phylogenetic analyses showed that this NFLG sequence contains three A7 segments, four G segments and one A1 segment with seven breakpoints, and all these segments were closely related to HIV-1 references circulating in Africa. The evidence from epidemiological investigation indicated that this female participant had a more-than-two-years heterosexual contact history with a fixed partner from Nigeria, a country in west Africa, which further supported the results of phylogenetic analyses. By the Bayesian phylogenetic analyses, the times of most recent common ancestors (tMRCA) of the partial pol gene (nt2308-3284, A7 region) and full-length vpr-vpu plus partial env gene (nt5534-6858, G region) were estimated around 1989 and 1984, respectively. CONCLUSIONS: In this study, by using the NFLG sequencing, we identified an imported HIV-1 A1/A7/G recombinant which was estimated to originate around 1980s in Africa and introduced into China with international migration. This study highlighted the complexity of the global HIV-1 epidemic, the necessity of using genome sequences to determine HIV-1 genotypes and the importance of real-time monitoring of HIV-1 infection among international migrants and travelers.

Electroencephalogram-based objective assessment of cognitive function level associated with age-related hearing loss.

Age-Related Hearing Loss (ARHL) is a common problem in aging. Numerous longitudinal cohort studies have revealed that ARHL is closely related to cognitive function, leading to a significant risk of cognitive decline and dementia. This risk gradually increases with the severity of hearing loss. We designed dual auditory Oddball and cognitive task paradigms for the ARHL subjects, then obtained the Montreal Cognitive Assessment (MoCA) scale evaluation results for all the subjects. Multi-dimensional EEG characteristics helped explore potential biomarkers to evaluate the cognitive level of the ARHL group, having a significantly lower P300 peak amplitude coupled with a prolonged latency. Moreover, visual memory, auditory memory, and logical calculation were investigated during the cognitive task paradigm. In the ARHL groups, the alpha-to-beta rhythm energy ratio in the visual and auditory memory retention period and the wavelet packet entropy value within the logical calculation period were significantly reduced. Correlation analysis between the above specificity indicators and the subjective scale results of the ARHL group revealed that the auditory P300 component characteristics could assess attention resources and information processing speed. The alpha and beta rhythm energy ratio and wavelet packet entropy can become potential indicators to determine working memory and logical cognitive computation-related cognitive ability.

Methodological and reporting quality of systematic reviews on health effects of air pollutants were higher than extreme temperatures: a comparative study.

BACKGROUND: An increasing number of systematic reviews (SRs) in the environmental field have been published in recent years as a result of the global concern about the health impacts of air pollution and temperature. However, no study has assessed and compared the methodological and reporting quality of SRs on the health effects of air pollutants and extreme temperatures. This study aims to assess and compare the methodological and reporting quality of SRs on the health effects of ambient air pollutants and extreme temperatures. METHODS: PubMed, Embase, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane Library, Web of Science, and Epistemonikos databases were searched. Two researchers screened the literature and extracted information independently. The methodological quality of the SRs was assessed through A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR 2). The reporting quality was assessed through Preferred Reporting Items of Systematic reviews and Meta-Analyses (PRISMA). RESULTS: We identified 405 SRs (286 for air pollution, 108 for temperature, and 11 for the synergistic effects). The methodological and reporting quality of the included SRs were suboptimal, with major deficiencies in protocol registration. The methodological quality of SRs of air pollutants was better than that of temperature, especially in terms of satisfactory explanations for any heterogeneity (69.6% v. 45.4%). The reporting quality of SRs of air pollution was better than temperature, however, adherence to the reporting of the assessment results of risk of bias in all SRs (53.5% v. 34.3%) was inadequate. CONCLUSIONS: Methodological and reporting quality of SRs on the health effect of air pollutants were higher than those of temperatures. However, deficiencies in protocol registration and the assessment of risk of bias remain an issue for both pollutants and temperatures. In addition, developing a risk-of-bias assessment tool applicable to the temperature field may improve the quality of SRs.

Preparation and Characterization of Carbide Particle-Toughened Si-B System of High Thermostability Polycrystalline Diamond by HPHT Sintering.

In this research, we report the synthesis of Si-TmC-B/PCD composites using Si, B, and transition metal carbide particles (TmC) as binders at high pressure and high temperature (HPHT method, 5.5 GPa and 1450 °C). The microstructure, elemental distribution, phase composition, thermal stability, and mechanical properties of PCD composites were systematically investigated. The Si-B/PCD sample is thermally stable in air at 919 °C. The initial oxidation temperature of the PCD sample with ZrC particles is as high as 976 °C, and it also has a maximum flexural strength of 762.2 MPa, and the highest fracture toughness of 8.0 MPa·m1/2.

Identification of a novel HIV-1 second-generation circulating recombinant form (CRF136_0107) among MSM in China.

OBJECTIVE: To investigate the molecular epidemiology of HIV-1 in Heilongjiang, China, and try to spot signs of new circulating recombinant form (CRF) in this region. DESIGN: A molecular epidemiological study was conducted in Heilongjiang, China during 2011-2020. METHODS: Plasma samples were collected from three HIV-1-positive patients (two MSM and one man lacking risk factor information). The near full-length genome sequences (NFLGs) of a novel CRF were then obtained and subjected to phylogenetic analysis using Mega 7.0.26. Recombination analysis was performed by the jumping profile Hidden Markov Model (jpHMM). Finally, the origin time of this novel CRF was inferred using the Bayesian phylogenetic analysis in Beast v1.10.4. RESULTS: The three NFLGs formed a distinct monophyletic cluster in the neighbor-joining (NJ) tree. Recombination analysis revealed that the recombinant genome was composed of five segments derived from CRF01_AE, subtypes B, and C, but further confirmed to be a second-generation recombinant form of CRF01_AE/CRF07_BC by a comparison of genome maps and subregion phylogenetic analysis and, therefore, designated as CRF136_0107. With Bayesian phylogenetic analysis, CRF136_0107 was estimated to originate around 2010-2011. CONCLUSION: A novel HIV-1 CRF01_AE/CRF07_BC second-generation CRF called CRF136_0107 was identified among MSM in Heilongjiang, a northeast province of China.

Association of macronutrients intake distribution with osteoarthritis risk among adults in NHANES, 2013-2016.

The association between dietary macronutrient distribution and the risk of OA remains unknown. We aimed to evaluate how dietary macronutrient distribution was correlated with the risk of OA in US adults. We performed a cross-sectional study consisting of 7,725 participants from National Health and Nutrition Examination Survey (NHANES) 2013-2016. Dietary macronutrient intake and OA status were assessed by using dietary recall method and self-reported questionnaire, respectively. We evaluated the association between dietary macronutrient distribution and the risk of OA using multivariate regression models. We conducted the isocaloric substitution analysis using the multivariate nutrient density method. Higher percentage of energy intake from fat was associated with higher risk of OA [OR = 1.05 (95% CI, 1.00, 1.09); P = 0.034]. No significant correlation was observed between the percentage of energy intake from carbohydrate or protein and risk of OA. Isocaloric substitution analysis revealed that only the substitution between fat and carbohydrate was significantly associated with the risk of OA [OR = 1.05 (95% CI, 1.003 to 1.09); P = 0.037]. Our findings suggested that a diet with low percentage of energy intake from fat may be beneficial in the prevention of OA. Further prospective cohort studies are needed to assess our results.

Gut microbiota-bile acids-glucagon like peptide-1 axis contributes the resistance to high fat diet-induced obesity in mice.

In human and rodents, some individuals may remain lean even when they are challenged with high calorie intake. Here, we used C57BL/6J mice to establish animal models of high-fat diet (HFD) induced obesity sensitive (DIO) mice and obesity resistant (DIR) mice. In DIR mice, improved metabolic profile through brown adipose tissue (BAT) activation was observed, while plasma unconjugated bile acids (BAs) were decreased together with increased intestine tauro-conjugated BAs (e.g., T-ß-MCA). The composition of the gut flora also differs greatly between DIR and DOR. Using fecal microbiota transplants from DIR mice, HFD fed recipient mice exhibited a trend toward reduced adiposity and improved glucose tolerance, showing increased serum tauro-conjugated BAs levels. STC-1 cell experiments confirmed T-ß-MCA could activate FXR/TGR5 pathway and induce the production of GLP-1, inhibiting genes that regulate the ceramide synthesis. Our results indicated that the DIR mice exhibited higher energy expenditure by activating BAT thermogenesis, which may be related to altered gut microbiota-bile acids-glucagon like peptide-1 axis.

Association between red blood cell distribution width and psoriasis among the US adults.

Introduction: The association between red blood cell distribution width (RDW) and psoriasis among the US adults is still unknown. We aimed to assess whether RDW is associated with psoriasis in the US adults. Method: We conducted a cross-sectional study consisting of 14,089 participants from National Health and Nutrition Examination Survey (NHANES) 2009-2014. Psoriasis status were assessed by self-reported questionnaire. We evaluated the association between RDW and risk of psoriasis using multivariate regression models. Subgroup and interaction analysis were performed. Results: The higher RDW level was associated with an increased risk of psoriasis (OR = 1.10 [95% CI, 1.01, 1.19]; p = 0.025) after adjusting for confounders in female. However, there is no significant association between RDW and risk of psoriasis among male (OR = 0.99 [95% CI, 0.87, 1.15]; p = 0.992). Subgroup and interaction analysis found that the strongest positive association mainly exists in female participants with BMD greater than 29.9 kg/m2 (OR = 1.20 [95% CI, 1.09, 1.32], Pint = 0.004). Discussion: In conclusion, we found that increased RDW levels were associated with an increased risk of psoriasis in females, which could provide clinicians with auxiliary data for the early diagnosis of psoriasis.

Young MSM changed temporal HIV-1 epidemic pattern in Heilongjiang Province, China.

Background: Human immunodeficiency virus type 1 (HIV-1) epidemic in China is featured by geographical diversity of epidemic patterns. Understanding the characteristics of regional HIV-1 epidemic allows carrying out targeted prevention and controlling measures. This seven-year cross-sectional study was conducted in Heilongjiang, one province of Northeast China, where newly diagnosed infection is fast increasing yearly, but temporal HIV-1 epidemic trend is largely unknown. Methods: Information of 1,006 newly diagnosed HIV-1-infected participants were collected before antiretroviral therapy during 2010-2016 in Heilongjiang province. HIV-1 genotype was identified based on the viral gag and env gene sequences. Recent infection was determined by Limiting-Antigen Avidity assays. Comparison analyses on the median ages, CD4 counts, proportions of stratified age groups and CD4 count groups, and rates of recent HIV-1 infection among different population and sampling times were performed to understand temporal HIV-1 epidemic features. Results: Homosexual contact among men who have sex with men (MSM) was the main transmission route and CRF01_AE was the most dominant HIV-1 genotype. During 2010-2016, the HIV-1 epidemic showed three new changes: the median age continued to decline, the cases with a CD4 count more than 500 cells/µl (CD4hi cases) disproportionally expanded, and the recent HIV-1 infection rate steadily increased. MSM cases determined the temporal trend of HIV-1 epidemic here. Increase of young MSM cases (aged <30 years) made the main contribution to the younger age trend of MSM cases. These young MSM exhibited a higher median CD4 count, a higher proportion of CD4hi cases, and a higher rate of recent HIV-1 infection than cases aged 30 years and more. MSM infected by CRF01_AE virus mostly affected HIV-1 epidemic patterns among MSM population. Conclusion: Young MSM have become a new hotspot and vulnerable group for HIV-1 transmission in Heilongjiang Province, Northeast China. The rapid increase in the number of young MSM cases, mainly those with CRF01_AE infection, changed temporal HIV-1 epidemic pattern here. Measures for prevention and control of HIV-1 infection among this population are urgently needed in the future.

Effect of Physical Exercise on College Students' Life Satisfaction: Mediating Role of Competence and Relatedness Needs.

This study examined the effect of physical exercise on the life satisfaction among college students. On the basis of the Basic Psychological Need Theory, the mediating roles of competence and relatedness needs satisfaction and their differences among college students in physical education (PE) majors and non-PE majors were explored. The sample included 1,012 college students who were selected to participate in an online survey. Major findings were as follows: (1) The total effect of physical exercise commitment on college students' life satisfaction was marginally significant while that of physical exercise adherence was not significant; (2) The effect of physical exercise commitment was observed exclusively through the mediating role of relatedness need satisfaction, while that of physical exercise adherence was through both competence and relatedness needs satisfaction; (3) In terms of differences caused by major, only one mediation path, that was, physical exercise → competence need satisfaction → college students's life satisfaction was significant among PE majors. This study thus enriched the empirical research on the benefits of physical exercise to individual mental health, highlighted the particularity of college students majoring in PE, and provided targeted and sensible suggestions for the design of physical exercise intervention programs.

Corporate Co-Agglomeration and Green Economy Efficiency in China.

This paper uses panel OLS, IV, and system GMM methods to empirically study the effects of manufacturing and producer service corporate co-agglomeration on green economy efficiency (GEE) in China. Chinese panel data from 2000 to 2019 are collected to assess the GEE and co-agglomeration degrees. The regression results show that there is an "inverted U-shaped" relationship between co-agglomeration and GEE. However, regional heterogeneity is found in the effects of corporate co-agglomeration on GEE. The mediating analysis indicates that corporate co-agglomeration could increase GEE through business entrepreneurship and innovation entrepreneurship. Variables such as transportation infrastructure, human capital, foreign direct investment, and environmental regulations are also found to have an elevating effect on GEE, whereas local fiscal expenditure on environmental protection has little effect. The findings in this paper indicate that entrepreneurship plays an important role in the process of co-agglomeration impacting GEE which differs in different regions and thus provide references for corporate and regional sustainable development.

Gm-PLoc: A Subcellular Localization Model of Multi-Label Protein Based on GAN and DeepFM.

Identifying the subcellular localization of a given protein is an essential part of biological and medical research, since the protein must be localized in the correct organelle to ensure physiological function. Conventional biological experiments for protein subcellular localization have some limitations, such as high cost and low efficiency, thus massive computational methods are proposed to solve these problems. However, some of these methods need to be improved further for protein subcellular localization with class imbalance problem. We propose a new model, generating minority samples for protein subcellular localization (Gm-PLoc), to predict the subcellular localization of multi-label proteins. This model includes three steps: using the position specific scoring matrix to extract distinguishable features of proteins; synthesizing samples of the minority category to balance the distribution of categories based on the revised generative adversarial networks; training a classifier with the rebalanced dataset to predict the subcellular localization of multi-label proteins. One benchmark dataset is selected to evaluate the performance of the presented model, and the experimental results demonstrate that Gm-PLoc performs well for the multi-label protein subcellular localization.

Responses of soil nematode community within soil aggregates to tea plantation age.

It is increasingly believed that soil nematodes play an important role in the soil community and have a pronounced influence on the evaluation of soil health and the monitoring of soil food web changes. Soil aggregates provide habitable pore space and resource availability for soil organisms. The distribution of soil nematodes, which are relatively small soil fauna, may be related to the degree of soil aggregates. Soil nematode communities were studied with different soil components: large macro-aggregates (> 2 mm), medium macro-aggregates (2-1 mm), small macro-aggregates (1-0.25 mm), and micro-aggregates (< 0.25 mm) extracted from the same crop variety plantings (Sichuan tea) of different ages (19 years, 26 years, 34 years, and 56 years) in Sichuan province, southwestern China, in 2018. The results showed that the tea plantation with 26 years of cultivation was more suitable for the propagation of nematode communities, and the numbers of total nematodes were highest in the > 2 mm fractions. Compared with other tea plantations, the Margalef index (SR) of 26-year-old tea plantation was significantly higher than that within the large and medium macro-aggregates, and the maturity index (MI) was higher in the large and small macro-aggregates in the 26-year-old tea plantation. In the large macro-aggregates, the value of functional metabolic footprints decreased with the tea plantation age. In addition, the functional metabolic footprints increased with the increase in soil aggregate size. Our finding suggests that nematode communities are limited by resource availability and resource quality played an important role in determining nematode communities. Moreover, the soil food web was degenerated with the age of tea cultivation. Therefore, in the study area, it is necessary to pay attention to the rational allocation and application of organic fertilizer in the late stage of tea planting, so as to maintain the soil fertility and soil food web structure of the tea garden.

Relationship of Soil Microbiota to Seed Kernel Metabolism in Camellia oleifera Under Mulched.

An experiment was conducted from 2016 to 2017 to assess the effect of kernel metabolism in development stages after organic mulching compared to control. Organic mulching significantly increased crop yields (higher 128% in 2016, higher 60% in 2017), oil content (the highest oil content was 27.6% higher than that of the control), and improved soil properties (SOC, SAN, AP, and AK). In this study, soil pH, SOC, AN, AP, and AK in 0-30 cm soil depth were measured. Results showed that the effect of mulching on soil pH was not significant at the harvesting stage. The greatest metabolic differences occurred during the period of high oil conversion (S2-S4), primarily involving 11 relevant metabolic pathways. This further verified that Camellia oleifera oil yield was improved after mulching. A total of 1,106 OTUs were detected by using 16S rRNA, and Venn diagram showed that there were 106 unique OTUs in control and 103 OTUs in the treatment, respectively. Correlation analysis showed that soil pH and soil temperature were two indicators with the most correlations with soil microbiota. The yield was significantly positively correlated with soil microbial Proteobacteria, Bacteroidetes, and soil nutrition indexes. Organic mulching improved the physicochemical properties of soils, caused differences in the relative abundance of dominant bacteria in soil bacteria, and improved the soil microbiological environment to promote plant growth, indicating that organic mulching is an effective measure to alleviate seasonal drought.

Suitable coverage and slope guided by soil and water conservation can prevent non-point source pollution diffusion: A case study of grassland.

Non-point source pollution caused by surface runoff has been a popular hydrological and environmental safety issue and has attracted extensive attention from global scholars. To identify the optimal vegetation coverage of Festuca arundinacea grassland for controlling soil erosion and purifying surface runoff, bare land was chosen as the control in this experiment. Simulated rainfall experiments were carried out with three levels of coverage (low coverage, moderate coverage and full coverage) under four slope conditions (flat slope, gentle slope, medium slope, and steep slope) and at four rainfall intensities (moderate rainfall, heavy rainfall, rainstorm and heavy rainstorm). The comprehensive evaluation results suggested that the capacity of Festuca arundinacea grassland for reducing the surface runoff, sediment yield, suspended solids (SS), total nitrogen (TN), total phosphorus (TP) and chemical oxygen demand (COD) decreased with increasing rainfall intensity and slope but increased with increasing vegetation coverage. Structural equation model (SEM) results suggested that there were positive relationships between the vegetation coverage and purification capacity index and negative correlations between the rainfall intensity and slope and the purification capacity index. The response surface analysis results suggested that the optimal vegetation coverage should be higher than 84% and that the slope should be smaller than 10° for controlling soil erosion and avoiding pollution via diffusion with surface runoff in Festuca arundinacea grassland. This study proposes recommendations for the vegetation configuration pattern in the development and management of runoff purification systems.