Grazing exclusion is more effective for vegetation restoration and nutrient transfer in the heavily degraded desert steppe.

BACKGROUND: Grazing exclusion is an efficient practice to restore degraded grassland ecosystems by eliminating external disturbances and improving ecosystems' self-healing capacities, which affects the ecological processes of soil-plant systems. Grassland degradation levels play a critical role in regulating these ecological processes. However, the effects of vegetation and soil states at different degradation stages on grassland ecosystem restoration are not fully understood. To better understand this, desert steppe at three levels of degradation (light, moderate, and heavy degradation) was fenced for 6 years in Inner Mongolia, China. Community characteristics were investigated, and nutrient concentrations of the soil (0-10 cm depth) and dominant plants were measured. RESULTS: We found that grazing exclusion increased shoots' carbon (C) concentrations, C/N, and C/P, but significantly decreased shoots' nitrogen (N) and phosphorus (P) concentrations for Stipa breviflora and Cleistogenes songorica. Interestingly, there were no significant differences in nutrient concentrations of these two species among the three degraded desert steppes after grazing exclusion. After grazing exclusion, annual accumulation rates of aboveground C, N, and P pools in the heavily degraded area were the highest, but the aboveground nutrient pools were the lowest among the three degraded grasslands. Similarly, the annual recovery rates of community height, cover, and aboveground biomass in the heavily degraded desert steppe were the highest among the three degraded steppes after grazing exclusion. These results indicate that grazing exclusion is more effective for vegetation restoration in the heavily degraded desert steppe. The soil total carbon, total nitrogen, total phosphorus, available nitrogen, and available phosphorus concentrations in the moderately and heavily degraded desert steppes were significantly decreased after six years of grazing exclusion, whereas these were no changes in the lightly degraded desert steppe. Structural equation model analysis showed that the grassland degradation level mainly altered the community aboveground biomass and aboveground nutrient pool, driving the decrease in soil nutrient concentrations and accelerating nutrient transfer from soil to plant community, especially in the heavily degraded grassland. CONCLUSIONS: Our study emphasizes the importance of grassland degradation level in ecosystem restoration and provides theoretical guidance for scientific formulation of containment policies.

Simulation and an experimental study on the optical performance of a Wolter-I focusing mirror based on a 3D ray tracing algorithm.

The nested Wolter-I type focusing mirror is widely used in the field of X-ray astronomy. The thin-shell mirrors produced by the electroforming replication method will introduce various shape errors during the fabricating and assembling process. This study introduces a non-analytical 3D geometrical ray tracing algorithm capable of predicting optical performance for large mirror deformations. The algorithm's implementation involves error reconstruction, light source and ray simulation, and optical performance calculation. Experimental and simulation validation underscores the algorithm's precision and effectiveness. The results also indicate that edge deformation can seriously affect imaging contrast which is generally considered to be determined only by surface scattering. Applying the 3D ray tracing algorithm, a range of low-frequency fabrication and assembly errors are simulated, such as absolute radius, taper, roundness, edge effects, mirror posture, and hoisting deformation errors, and their effects on imaging quality are analyzed and discussed.

Effect of open versus minimally invasive surgery on postoperative wound site complications in patients with recurrent shoulder instability: A meta-analysis.

The Latarjet procedure is the accepted method of operation for patients with anterior shoulder instability. However, as arthroscopy becomes more and more popular, more and more patients are being treated with minimally invasive techniques for the treatment of anteriorly unstable shoulder. This research aims to compare the curative effects of arthroscopic Latarjet (AL) and open Latarjet (OL) on postoperative anterior shoulder instability. Our hypothesis is that arthroscopy will produce better results than open surgery. During the study, a review was conducted on four main databases, including EMBASE and Cochrane Library. Six cohort studies comparing AL with OL in the treatment of anterior shoulder instability were included. Patients who were operated by open technique up to 2023 were referred to as OL and those who underwent arthroscopic surgery were referred to as AL. Comparison was made between the two methods of operation. The statistical analysis was done with RevMan 5.3. The analysis included Visual Analogue Scale (VAS) scores and postoperative wound infections. A total of six studies were included for analysis under inclusion and exclusion criteria. There were 798 patients, 476 was AL group and 322 was OL group. No statistical significance was found on the incidence of postoperative wound infection in the patients who underwent the Latarjet procedure (odds ratio [OR], 1.43; 95% confidence interval [CI], 0.28-7.31; p = 0.67) and the VAS score after surgery (mean difference [MD], 0.70; 95% CI, -0.67 to 2.06; p = 0.32) for patients. However, it has now been demonstrated that arthroscopy is a safe and viable alternative. The only drawback of arthroscopic Latarjet surgery is probably that it has a long learning curve and requires a lot of practice from the surgeon.

Nutrient reallocation between stem and leaf drives grazed grassland degradation in inner Mongolia, China.

BACKGROUND: Decline in height and aboveground biomass of the plant community are critical indicators of grassland ecosystem degradation. Nutrient reallocation induced by grazing occurs among different organs, which balances the trade-off between growth and defense. However, it is not yet clear how nutrient reallocation strategies affect plant community structure and functions in grazed grasslands. A grazing experiment was conducted in a typical steppe in Inner Mongolia, China. We investigated plant community characteristics and measured plant functional traits of dominant species (Leymus chinensis and Cleistogenes squarrosa) at individual and population levels. Carbon (C), nitrogen (N), phosphorus (P), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn) concentrations of stem and leaf in the two species were also determined. RESULTS: N, P, Cu, Fe, Mn, and Zn concentrations in leaves and stems of L. chinensis and C. squarrosa significantly increased with grazing intensity, and microelements (Cu, Fe, Mn, and Zn) were more sensitive to grazing. The nutrient slopes of macro- and microelements in leaves were significantly higher than those in stems under grazing, indicating that nutrient resources were preferentially allocated to leaves and enhanced the compensatory growth of leaves in the grazed grassland. With increasing grazing intensity, the aboveground biomass of stems and leaves in the two species significantly decreased, but leaf to stem ratio increased at the individual level, indicating that plants preferentially allocated biomass to leaves under grazing. The increase in leaf to stem ratio due to nutrient reallocation between the two organs significantly reduced height and aboveground biomass at population and community levels, driving grassland ecosystem degradation. CONCLUSION: Our study revealed the driving forces of community structure and function degradation in grazed grasslands from the perspective of nutrient resource allocation, and provided insights into plant adaptation strategies to grazing.

Hsa_circ_0007482 Promotes Proliferation and Differentiation of Chondrocytes in Knee Osteoarthritis.

OBJECTIVE: Knee osteoarthritis (KOA) is a complex degenerative joint disease and a major cause of joint dysfunction. This study aimed to explore the function of hsa_circ_0007482 on inflammation, proliferation, differentiation, and apoptosis in KOA. DESIGN: Real-time quantitative polymerase chain reaction (PCR) was performed to detect the expression of circ_0007482, inflammatory factors, and differentiation-related molecules in KOA chondrocytes and interleukin (IL)-1ß-stimulated chondrocytes. The correlation between the circ_0007482 expression and inflammatory factors was analyzed by the Pearson method. KOA cell model was established using IL-1ß for 24 hours. The proliferation activity of chondrocytes was evaluated by CCK-8 assay, and cell apoptosis rate was assessed by flow cytometry. The downstream miRNA of circ_0007482 was validated using dual-luciferase reporter assay. RESULTS: The circ_0007482 expression was elevated in both KOA cartilage tissues and IL-1ß-treated chondrocytes and positively correlated with inflammatory factors expression. In comparison to the control group, IL-1ß treatment diminished chondrocyte proliferation abilities and increased cell apoptosis and inflammatory factors IL-6, IL-8, and tumor necrosis factor (TNF)-α mRNA expression. Inhibition of circ_0007482 partially improved IL-1ß-induced inflammatory reaction. Circ_0007482 could negatively regulate the expression of miR-558. CONCLUSIONS: Interfering of circ_0007482 might partially promote cell proliferation and differentiation, while inhibit cell apoptosis to improve joint injury by regulating miR-558 in IL-1ß-treated chondrocyte cell model.

Assessment on malvidin-3-glucoside interaction with TLR4 via multi-spectroscopic analysis and molecular docking.

As one innate immune pattern recognition receptor, Toll-like receptor 4 (TLR4) recently has been considered as a critical player in glucolipid metabolism. Blueberries contain high level of anthocyanins, especially malvidin-3-glucoside (Mv-3-glc), which contribute the anti-inflammatory, hypoglycemic, and hypolipidemic effects. It is speculated that Mv-3-glc is able to possess these functions by binding to TLR4. Here, the noncovalent interactions of Mv-3-glc and TLR4 was explored through multi-techniques including fluorescence and ultraviolet-visible (UV-Vis) absorption spectroscopy, as well as molecular docking. The results demonstrated that Mv-3-glc was able to quench TLR4 intrinsic fluorescence effectively. A stable complex was formed spontaneously and the reaction was exothermic. The degree of binding of Mv-3-glc to TLR4 showed a strong dependence on the chemical concentration, temperature, and pH values. The negative signs for enthalpy (ΔH = -69.1 ± 10.8 kJ/mol) and entropy (ΔS = -105.0 ± 12.3 J/mol/K) from the interaction of the Mv-3-glc and TLR4 shows that the major driving forces are the hydrogen bonding and van der Waals' force, which is consistent with the molecular docking results. In addition, molecular docking predicted that the active center with specific amino acid residues, Phe126, Ser127, Leu54, Ile153, and Tyr131 was responsible for the site of Mv-3-glc binding to TLR4/myeloid differentiation protein-2 (MD-2). These findings confirmed that Mv-3-glc could bind to TLR4, which would be beneficial to understand the target therapeutic effects of blueberry anthocyanins on TLR4 in regulating glucolipid metabolism.

Comprehensive analysis of cell death genes in hepatocellular carcinoma based on multi-omics data.

BACKGROUND: Hepatocellular carcinoma (HCC) is a common tumor of the digestive system. Cell death is an essential process in normal tissue that consists of 3 classical pathways: apoptosis, necrosis and autophagy. OBJECTIVES: To perform a comprehensive analysis of the impact of cell death on liver cancer. MATERIAL AND METHODS: The Kyoto Encyclopedia of Genes and Genomes (KEGG) database and the Cancer Genome Atlas (TCGA) datasets were used to analyze the relationships between mutations in cell death-related genes and clinical variables of HCC. Then, we applied the DESeq2 package to identify aberrantly expressed genes in HCC and their related biological functions through a Pearson correlation analysis. Finally, a cell death-related signature of HCC was constructed using the single-factor Cox regression. RESULTS: We identified the genes involved in apoptosis, necrosis and autophagy, of which TP53 and SPTA1 had the highest frequency of mutations. The results revealed that cell death-related tumor mutational burden (TMB) was significant for the pathologic stage and had a strong relationship with the prognosis. Moreover, 53 cell death-related genes that are differentially expressed in HCC were screened, and 3 of them were correlated with HCC prognosis. Harvey rat sarcoma viral oncogene homolog (HRAS) affected the infiltration of immune cells and was closely correlated with ferroptosis. Peptidylprolyl isomerase A (PPIA) played a significant role in mitochondrial pathways. At last, we constructed a cell death-related signature of HCC using 10 prognosis-related genes and a nomogram based on 3 variables (expression, group and stage). CONCLUSIONS: This study provided a comprehensive analysis of cell death-related genes in HCC based on multi-omics data, identified the contribution of each variable to clinical outcome and predicted the survival probability of HCC patients more directly.

Comparison of plant diversity-carbon storage relationships along altitudinal gradients in temperate forests and shrublands.

Understanding the mechanisms underlying the relationship between biodiversity and ecosystem function (BEF) is critical for the implementation of productive and resilient ecosystem management. However, the differences in BEF relationships along altitudinal gradients between forests and shrublands are poorly understood, impeding the ability to manage terrestrial ecosystems and promote their carbon sinks. Using data from 37962 trees of 115 temperate forest and 134 shrubland plots of Taihang Mountains Priority Reserve, we analyzed the effects of species diversity, structural diversity, climate factors and soil moisture on carbon storage along altitudinal gradients in temperate forests and shrublands. We found that: (1) Structural diversity, rather than species diversity, mainly promoted carbon storage in forests. While species diversity had greater positive effect on carbon storage in shrublands. (2) Mean annual temperature (MAT) had a direct negative effect on forest carbon storage, and indirectly affected forest carbon storage by inhibiting structural diversity. In contrast, MAT promoted shrubland carbon storage directly and indirectly through the positive mediating effect of species diversity. (3) Increasing altitudinal gradients enhanced the structural diversity-carbon relationship in forests, but weakened the species diversity-carbon relationship in shrublands. Niche and architectural complementarity and different life strategies of forests and shrubs mainly explain these findings. These differential characteristics are critical for our comprehensive understanding of the BEF relationship and could help guide the differentiated management of forests and shrublands in reaction to environmental changes.

LncRNA XIST Prevents Tendon Adhesion and Promotes Tendon Repair Through the miR-26a-5p/COX2 Pathway.

Tendon adhesion is the biggest obstacle to repair of tendon injury. Long-chain non-coding RNA X-inactive specific transcript (lncRNA XIST) is highly expressed in populations at high risk of tendon injury. However, whether XIST participates in tendon injury and the specific mechanism remain unknown. Here, we aimed to explore the effects and underlying mechanism of XIST in tendon injury. A mouse model of tendon injury was constructed by the transection method in vivo. XIST and COX2 were highly expressed in tendon tissues of mice with tendon injury, while miR-26a-5p was lowly expressed. Fibroblasts were isolated from tendon injury mice. Overexpression of XIST promoted fibroblast proliferation and upregulated α-SMA and Collagen I protein expression, while silencing XIST indicated the opposite effects. Further dual-luciferase reporter gene assay and RIP assay verified a targeting relationship between XIST and miR-26a-5p, as well as miR-26a-5p and COX2, and XIST targeted miR-26a-5p to act on COX2 expression. miR-26a-5p inhibition and COX2 overexpression reversed the decrease in fibroblast proliferation and the downregulation of α-SMA and Collagen I expression caused by XIST silencing, while interference with si-COX2 eliminated the effects of miR-26a-5p inhibitor. This study revealed that XIST promoted fibroblast proliferation and the formation of tendon adhesion through miR-26a-5p/COX2 pathway, suggesting that XIST/miR-26a-5p/COX2 may be a potential target for the treatment of tendon injury.

Research on a tunable monochromatic X-rays source in (5∼40) keV.

The monochromatic X-rays produced by Bragg diffraction has the advantage of continuously adjustable energy, which is the preferred scheme to realize the monochromatic X-rays. In order to establish a (5-40) keV monochromatic X-rays facility, the Bragg diffraction of crystal monochromator is studied. The position of the emitted X-rays beam is required to remain unchanged when the Bragg angle is adjusted to accurately calibrate the detection efficiency. The monochromatic X-rays calibration facility is mainly composed of an X-rays tube, diffraction crystal and synchronous rotating device, which could cover the energy range of (5-40) keV. A new mechanical structure was invented to realize the linkage between crystal and X-rays tube. When the Bragg angle of crystal is adjusted at θ, the X-ray source will rotate at 2θ angle, and the position of the monochromatic X-rays beam will remain unchanged. Based on the Monte Carlo simulation program, the geometric structure model of silicon drift detector is established. The structure of the detector is optimized according to the experimental conditions and the material size of the shell, window and crystal of the detector. The accurate and reliable detector model is obtained. The response of the detector to different energy under the parallel X-rays source is calculated, and the detection efficiency curve is obtained. The detection efficiency is calibrated by using standard radiation source to ensure the accuracy of photon flux measurement. The energy range, flux, monochromaticity and spot distribution of the monochromatic X-rays radiation device are measured.

Asymmetric effects of grazing intensity on macroelements and microelements in grassland soil and plants in Inner Mongolia Grazing alters nutrient dynamics of grasslands.

Grazing is a traditional grassland management technique and greatly alters ecosystem nutrient cycling. The effects of grazing intensity on the nutrient dynamics of soil and plants in grassland ecosystems remain uncertain, especially among microelements. A 2-year field grazing experiment was conducted in a typical grassland with four grazing intensities (ungrazed control, light, moderate, and heavy grazing) in Inner Mongolia, China. Nutrient concentration was assessed in soil and three dominant plant species (Stipa krylovii, Leymus chinensis, and Cleistogenes squarrosa). Assessed quantities included four macroelements (carbon (C), nitrogen (N), phosphorus (P), and magnesium (Mg)) and four microelements (copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn)). Soil total C, total N, total P, available N, and available P concentrations significantly increased with grazing intensity but soil Mg, Cu, Fe, Mn, Zn concentrations had no significant response. Plant C concentration decreased but plant N, P, Mg, Cu, Fe, Mn, and Zn concentrations significantly increased with grazing intensity. In soil, macroelement dynamics (i.e., C, N, and P) exhibited higher sensitivity with grazing intensity, conversely in plants, microelements were more sensitive. This result indicates macroelements and microelements in soil and plants had asymmetric responses with grazing intensity. The slopes of nutrient linear regression in C. squarrosa were higher than that of S. krylovii and L. chinensis, indicating that C. squarrosa had higher nutrient acquisition capacity and responded more rapidly to heavy grazing. These findings indicate that short-term heavy grazing accelerates nutrient cycling of the soil-plant system in grassland ecosystems, elucidate the multiple nutrient dynamics of soil and plants with grazing intensity, and emphasize the important function of microelements in plant adaptation in grazing management.

Litter accumulation alters the abiotic environment and drives community successional changes in two fenced grasslands in Inner Mongolia.

Fencing is an effective and practical method for restoring degraded grasslands in northern China. However, little is known about the role of excess litter accumulation due to long-term fencing in regulating abiotic environment and driving changes in community structure and function. We conducted a three-year field experiment in two fenced grasslands in Inner Mongolia, and monitored light quantity, soil temperature, and soil moisture continuously, and determined community height, community aboveground net primary productivity (ANPP), and the relative dominance of different plant functional groups. Litter accumulation reduced light quantity and soil temperature but increased soil moisture. The regulating effects of litter accumulation on soil temperature and soil moisture fluctuated temporally and gradually weakened over the growing season. Litter accumulation also altered community vertical structure and function by increasing community height and ANPP. The increase in soil moisture increased the relative dominance of rhizome grasses but suppressed bunch grasses, thereby shifting bunch grass grasslands to rhizome grass grasslands. Our findings provide a potential mechanism for community succession in the context of litter accumulation in fenced grasslands and indicate that the vegetation and ecosystem services of degraded grasslands are improved after appropriate fencing.