Rational Sampling Numbers of Soil pH for Spatial Variation: A Case Study from Yellow River Delta in China

Spatial variation of soil pH is important for the evaluation of environmental quality. A reasonable number of sampling points has an important meaning for accurate quantitative expression on spatial distribution of soil pH and resource savings. Based on the grid distribution point method, 908, 797, 700, 594, 499, 398, 299, 200, 149, 100, 75 and 50 sampling points, which were randomly selected from 908 sampling points, constituted 12 sample sets. Semi-variance structure analysis was carried out for different point sets, and ordinary Kriging was used for spatial prediction and accuracy verification, and the influence of different sampling points on spatial variation of soil pH was discussed. The results show that the pH value in Kenli County (China) was generally between 7.8 and 8.1, and the soil was alkaline. Semi-variance models fitted by different point sets could reflect the spatial structure characteristics of soil pH with accuracy. With a decrease in the number of sampling points, the Sill value of sample set increased, and the spatial autocorrelation gradually weakened. Considering the prediction accuracy, spatial distribution and investigation cost, a number of sampling points greater than or equal to 150 could satisfy the spatial variation expression of soil pH at the county level in the Yellow River Delta. This is equivalent to taking at least 107 sampling points per 1000 km2. The results in this study are applicable to areas with similar environmental and soil conditions as the Yellow River Delta, and have reference significance for these areas

Protective Effects of Millettia Pulchra Flavonoids on Myocardial Ischemia In Vitro and In Vivo

Background: Previous studies have demonstrated that Millettia pulchra flavonoids (MPF) exhibit protective effects on myocardial ischemia reperfusion injury (MI/RI) in isolated rat hearts and show anti-oxidative, anti-hypoxic and anti-stress properties. Methods: In this study, the cardioprotective effects of MPF on myocardial ischemia and its underlying mechanisms were investigated by a hypoxia/ reoxygenation (H/R) injury model in vitro and a rat MI/RI model in vivo. Results: We found that the lactate dehydrogenase (LDH) and inducible nitric oxide synthase (iNOS) activities were decreased in the MPF pretreatment group, whereas the activities of constructional nitric oxide synthase (cNOS), total nitric oxide synthase (tNOS), Na+-K+-ATPase and Ca2+-Mg2+-ATPase were significantly increased. In addition, the cardiocytes were denser in the MPF groups than in the control group. The mortality rate and apoptosis rate of cardiocytes were significantly decreased. Furthermore, pretreatment with MPF in vivo significantly improved the hemodynamics, decreased malondialdehyde (MDA) abundance, increased the activities of plasma superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and decreased the expression of the Bax protein and ratio Bax/Bc1-2 ration. Conclusions: These results suggest that MPF is an attractive protective substance in myocardial ischemia due to its negative effects on heart rate and ionotropy, reduction of myocardial oxidative damage and modulation of gene expression associated with apoptosis

Association between ambient temperature and semen quality among sperm donation volunteers in South China

Background: Potential adverse effects of non-optimum temperatures on human semen quality have drawn much concern worldwide; however, the exposure–response relationship remains less understood. Objectives: To quantitatively assess the association between exposure to ambient temperature and semen quality in South China, and to identify potential critical exposure windows. Methods: We conducted a longitudinal study to investigate 11,050 volunteers who lived in Guangdong province, China and intended to donate sperm in the Guangdong provincial human sperm bank during 2016–2021. Exposure to ambient temperature during 0–90 days before semen collection was assessed by extracting daily temperatures from a validated grid dataset at each subject’s residential address. Linear mixed models and linear regression models were used to perform exposure–response analyses. Results: During the study period, the 11,050 subjects underwent 44,564 semen analyses. Each 5 °C increase of lag 0–90 day exposure to ambient temperature was approximately linearly associated with a 3.11 (95 % confidence interval [CI]: 2.08, 4.14) × 106/ml, 9.31 (4.83, 13.80) × 106, 1.27 % (0.91 %, 1.62 %), 8.20 (5.33, 11.08) × 106, 1.37 % (1.01 %, 1.74 %), 8.29 (5.52, 11.06) × 106, 0.67 % (0.28 %, 1.05 %), and 4.50 (2.20, 6.80) × 106 reduction in sperm concentration, total sperm number, total motility, total motile sperm number, progressive motility, total progressive sperm number, normal forms, and total normal form sperm number, respectively (all p  0.05). We identified a critical exposure period of 10–14 days before semen collection for sperm motility, and 70–90 days before semen collection for sperm count and morphology. Conclusions: Our study provides consistent evidence that higher ambient temperature was significantly associated with a reduction in semen quality in South China. The findings highlight the needs to reduce high temperature exposures during 3 months before ejaculation to maintain better semen quality

S100A9+CD14+ monocytes contribute to anti-PD-1 immunotherapy resistance in advanced hepatocellular carcinoma by attenuating T cell-mediated antitumor function

Abstract Background The paucity of reliable biomarkers for predicting immunotherapy efficacy in patients with advanced hepatocellular carcinoma (HCC) has emerged as a burgeoning concern with the expanding use of immunotherapy. This study endeavors to delve into the potential peripheral biomarkers capable of prognosticating efficacy in HCC patients who are poised to receive anti-PD-1 monotherapy within the phase III clinical trial, KEYNOTE394. Additionally, we sought to elucidate the underlying molecular mechanisms for resistance to immune checkpoint blockade (ICB) and propose innovative combination immunotherapy strategies for future clinical application. Methods Patient blood samples were collected for single-cell RNA sequencing to evaluate the immune cell signature before receiving ICB therapy. Subsequently, in vitro assays and in vivo murine model experiments were conducted to validate the mechanism that S100A9+CD14+ monocytes play a role in ICB resistance. Results Our study demonstrates a notable enrichment of S100A9+CD14+ monocytes in the peripheral blood of patients exhibiting suboptimal responses to anti-PD-1 therapy. Moreover, we identified the Mono_S100A9 signature as a predictive biomarker, indicative of reduced efficacy in immunotherapy and decreased survival benefits across various tumor types. Mechanistically, S100A9 activates PD-L1 transcription by directly binding to the CD274 (PD-L1) gene promoter, thereby suppressing T-cell proliferation and cytotoxicity via the PD-1/PD-L1 axis, consequently diminishing the therapeutic effectiveness of subsequent anti-PD-1 treatments. Furthermore, our in vivo studies revealed that inhibiting S100A9 can synergistically enhance the efficacy of anti-PD-1 drugs in the eradication of hepatocellular carcinoma. Conclusions Our study underscores the significance of S100A9+CD14+ monocytes in predicting inadequate response to ICB treatment and provides insights into the monocyte cell-intrinsic mechanisms of resistance to ICB therapy. We also propose a combined therapeutic approach to enhance ICB efficacy by targeting S100A9

A Landsat-derived annual inland water clarity dataset of China between 1984 and 2018

Water clarity serves as a sensitive tool for understanding the spatial pattern and historical trend in lakes' trophic status. Despite the wide availability of remotely sensed data, this metric has not been fully explored for long-term environmental monitoring. To this end, we utilized Landsat top-of-atmosphere reflectance products within Google Earth Engine in the period 1984–2018 to retrieve the average Secchi disk depth (SDD) for each lake in each year. Three SDD datasets were used for model calibration and validation from different field campaigns mainly conducted during 2004–2018. The red  blue band ratio algorithm was applied to map SDD for lakes (>0.01 km2) based on the first SDD dataset, where R2=0.79 and relative RMSE (rRMSE) =61.9  %. The other two datasets were used to validate the temporal transferability of the SDD estimation model, which confirmed the stable performance of the model. The spatiotemporal dynamics of SDD were analyzed at the five lake regions and individual lake scales, and the average, changing trend, lake number and area, and spatial distribution of lake SDDs across China were presented. In 2018, we found the number of lakes with SDD 4 m were the largest, both accounting for about 24.00 % of the total lakes. During 1984–2018, lakes in the Tibetan–Qinghai Plateau region (TQR) had the clearest water with an average value of 3.32±0.38 m, while that in the northeastern region (NLR) exhibited the lowest SDD (mean 0.60±0.09 m). Among the 10 814 lakes with SDD results for more than 10 years, 55.42 % and 3.49 % of lakes experienced significant increasing and decreasing trends, respectively. At the five lake regions, except for the Inner Mongolia–Xinjiang region (MXR), more than half of the total lakes in every other region exhibited significant increasing trends. In the eastern region (ELR), NLR and Yungui Plateau region (YGR), almost more than 50 % of the lakes that displayed increase or decrease in SDD were mainly distributed in the area range of 0.01–1 km2, whereas those in the TQR and MXR were primarily concentrated in large lakes (>10 km2). Spatially, lakes located in the plateau regions generally exhibited higher SDD than those situated in the flat plain regions. The dataset is freely available at the National Tibetan Plateau Data Center (https://doi.org/10.11888/Hydro.tpdc.271571, Tao et al., 2021)

A microtubule stabilizer ameliorates protein pathogenesis and neurodegeneration in mouse models of repetitive traumatic brain injury.

Tau pathogenesis is a hallmark of many neurodegenerative diseases, including Alzheimers disease (AD). Although the events leading to initial tau misfolding and subsequent tau spreading in patient brains are largely unknown, traumatic brain injury (TBI) may be a risk factor for tau-mediated neurodegeneration. Using a repetitive TBI (rTBI) paradigm, we report that rTBI induced somatic accumulation of phosphorylated and misfolded tau, as well as neurodegeneration across multiple brain areas in 7-month-old tau transgenic PS19 mice but not wild-type (WT) mice. rTBI accelerated somatic tau pathology in younger PS19 mice and WT mice only after inoculation with tau preformed fibrils and AD brain-derived pathological tau (AD-tau), respectively, suggesting that tau seeds are needed for rTBI-induced somatic tau pathology. rTBI further disrupted axonal microtubules and induced punctate tau and TAR DNA binding protein 43 (TDP-43) pathology in the optic tracts of WT mice. These changes in the optic tract were associated with a decline of visual function. Treatment with a brain-penetrant microtubule-stabilizing molecule reduced rTBI-induced tau, TDP-43 pathogenesis, and neurodegeneration in the optic tract as well as visual dysfunction. Treatment with the microtubule stabilizer also alleviated rTBI-induced tau pathology in the cortices of AD-tau-inoculated WT mice. These results indicate that rTBI facilitates abnormal microtubule organization, pathological tau formation, and neurodegeneration and suggest microtubule stabilization as a potential therapeutic avenue for TBI-induced neurodegeneration

Additional file 1 of S100A9+CD14+ monocytes contribute to anti-PD-1 immunotherapy resistance in advanced hepatocellular carcinoma by attenuating T cell-mediated antitumor function

Additional file 1:Supplementary Fig. S1. Clinical efficacy of pembrolizumab in patients with advanced HCC. a Kaplan–Meier survival curves showing progression-free survival stratified by pembrolizumab group (red) and placebo group (blue). Significance calculated by the log-rank test. b Spider plot showing tumor responses over a long duration