Nutrient limitation mediates soil microbial community structure and stability in forest restoration.

Soil microorganisms are often limited by nutrients, representing an important control of heterotrophic metabolic processes. However, how nutrient limitations relate to microbial community structure and stability remains unclear, which creates a knowledge gap to understanding microbial biogeography and community changes during forest restoration. Here, we combined an eco-enzymatic stoichiometry model and high-throughput DNA sequencing to assess the potential roles of nutrient limitation on microbial community structure, assembly, and stability along a forest restoration sequence in the Qinling Mountains, China. Results showed that nutrient limitations tended to decrease during the oak forest restoration. Carbon and phosphorus limitations enhanced community dissimilarity and significantly increased bacterial alpha diversity, but not fungal diversity. Stochastic assembly processes primarily structured both bacterial (average contribution of 74.73 % and 74.17 % in bulk and rhizosheath soils, respectively) and fungal (average contribution of 77.23 % and 72.04 % in bulk and rhizosheath soils, respectively) communities during forest restoration, with nutrient limitation also contributing to the importance of stochastic processes in the bacterial communities. The migration rate (m) for bacteria was 0.19 and 0.23, respectively in both bulk soil and rhizosheath soil, and was greater than that for the fungi (m was 1.19 and 1.41, respectively), indicating a stronger dispersal limitation for fungal communities. Finally, nutrient limitations significantly affected bacterial and fungal co-occurrence with more interconnections occurring among weakly nutrient-limited microbial taxa and nutrient limitations reducing community stability when nutrient availability changed during forest restoration. Our findings highlight the fundamental effects of nutrient limitations on microbial communities and their self-regulation under changing environmental resources.

Carbene Footprinting Directs Design of Genetically Encoded Proximity-Reactive Protein Binders.

Genetically encoding proximal-reactive unnatural amino acids (PrUaas), such as fluorosulfate-l-tyrosine (FSY), into natural proteins of interest (POI) confer the POI with the ability to covalently bind to its interacting proteins (IPs). The PrUaa-incorporated POIs hold promise for blocking undesirable POI-IP interactions. Selecting appropriate PrUaa anchor sites is crucial, but it remains challenging with the current methodology, which heavily relies on crystallography to identify the proximal residues between the POIs and the IPs for the PrUaa anchorage. To address the challenge, here, we propose a footprinting-directed genetically encoded covalent binder (footprinting-GECB) approach. This approach employs carbene footprinting, a structural mass spectrometry (MS) technique that quantifies the extent of labeling of the POI following the addition of its IP, and thus identifies the responsive residues. By genetically encoding PrUaa into these responsive sites, POI variants with covalent bonding ability to its IP can be produced without the need for crystallography. Using the POI-IP model, KRAS/RAF1, we showed that engineering FSY at the footprint-assigned KRAS residue resulted in a KRAS variant that can bind irreversibly to RAF1. Additionally, we inserted FSY at the responsive residue in RAF1 upon footprinting the oncogenic KRASG12D/RAF1, which lacks crystal structure, and generated a covalent binder to KRASG12D. Together, we demonstrated that by adopting carbene footprinting to direct PrUaa anchorage, we can greatly expand the opportunities for designing covalent protein binders for PPIs without relying on crystallography. This holds promise for creating effective PPI inhibitors and supports both fundamental research and biotherapeutics development.

[Plant Diversity Changes and Its Driving Factors of Abandoned Land at Different Restoration Stages in the Middle of the Qinling Mountains].

The process of vegetation restoration is often accompanied by significant changes in aboveground plant diversity. To explore the driving mechanism of litter nutrient-soil nutrient-enzyme activity stoichiometry on aboveground vegetation change is of great importance for maintaining regional biodiversity conservation and ecological stability. Taking typical abandoned farmland of different restoration years （1， 8， 16， 31， and 50 a） in the Qinling Mountains as the research object， the variation characteristics of plant community diversity during vegetation restoration were analyzed through field investigation. Litter nutrients， soil nutrients， and the activities of five extracellular enzymes， including ß-1，4-glucosidase （BG）， cellobiohydrolase （CBH）， ß-1，4-N-acetylglucosaminidase （NAG）， leucine aminopeptidase （LAP）， and acid phosphatase （AP）， were determined. The characteristics of litter nutrients， soil nutrients， and enzyme stoichiometric ratios during vegetation restoration and the driving mechanism of plant diversity changes were discussed. The results showed that the plant community diversity index firstly decreased and then increased with the increase in vegetation restoration years， and the minimum was reached at 16 years after restoration. The results of principal component analysis showed that there were significant differences between total plant community diversity index and litter-soil-enzyme stoichiometric characteristics in different years of vegetation restoration. The plant community diversity index had a strong positive correlation with litter C∶P ratio and litter N∶P ratio but had a negative correlation with soil enzyme C∶P ratio （EEA C∶P）. The results of redundancy analysis showed that soil EEA C∶P had the highest explanation rate of plant diversity changes during vegetation restoration （25.93%）， followed by soil TP （5.94%）， which was the key factor regulating plant diversity changes. In conclusion， plant species and quantity increased significantly in abandoned farmland in the middle part of the Qinling Mountains at the late stage of vegetation restoration. Changes in the soil environment affected microbial metabolic activities and thus changed enzyme activities. Litter-soil-soil extracellular enzymes affected the community environment and plant diversity through feedback and regulation. EEA C∶P and TP were the main driving factors of aboveground plant diversity change during vegetation restoration.

Electrochemical determination of ethylvanillin based on LaV@GAC nanocomposite.

Ethyl vanillin (EVA) is widely used as a flavor additive in foods, and sensitive monitoring of EVA is of great significance for food safety. In this paper, the biomass of gum arabic derived carbon (GAC) coated with lanthanum vanadate (LaV) was constructed for the EVA sensor based on the synergistic effects of the electrochemical catalytic ability of LaV, the enhanced electrical conductivity with the GAC coating and the oxygen-containing functional groups in LaV@GAC. The as-developed LaV@GAC sensor showed a remarkable linear range from 0.06 µM to 100 µM and a low detection limit (LOD) of 6.28 nM. The electrochemical oxidation of EVA is limited by a diffusion-controlled process involving 2 electrons and 2 protons. Moreover, the LaV@GAC sensor has good recoveries (94.5-103.05%) for the detection of EVA in real milk powder samples. The proposed LaV@GAC sensor has good repeatability, high stability, and great potential for sensitive detection of flavor additives in food.

Pulmonary Function Test and Obstructive Sleep Apnea Hypopnea Syndrome in Obese Adults: A Retrospective Study.

Objective: We explore risk factors related to severe obstructive sleep apnea (OSA) in obese patients, including pulmonary ventilation function, diffusion function, and impulse oscillometry (IOS) data. Methods: The medical records of 207 obese patients who were prepared to undergo bariatric surgery in a hospital from May 2020 to September 2021 were retrospectively reviewed. Polysomnography (PSG), pulmonary ventilation function, diffusion function, and IOS parameters were collected according to the ethical standards of the institutional research committee (registration number: KYLL-202008-144). Logistic regression analysis was used to analyze the related independent risk factors. Results: There were significantly statistical difference in a number of pulmonary ventilation and diffusion function parameters among the non-OSAHS group, the mild-to-moderate OSA group, and the severe OSA group. However, only airway resistance parameters R5%, R10%, R15%, R20%, R25%, and R35% increased with increasing OSA severity and were positively correlated with apnea hypopnea index (AHI). Age (P = 0.012, 1.104 (1.022, 1.192)), body mass index (P< 0.0001, 1.12 (1.057, 1.187)), gender (P = 0.003, 4.129 (1.625, 10.49)), and R25% (P = 0.007, 1.018 (1.005, 1.031)) were independent risk factors for severe OSA. In patients aged 35 to 60, RV/TLC (P = 0.029, 1.272 (1.025, 1.577)) is an independent risk factor for severe OSA. Conclusion: R25% was an independent risk factor for severe OSA in obese individuals, while RV/TLC was also an independent risk factor in those aged 35 to 60. Pulmonary function tests (PFTs), particularly IOS levels, are recommended to assess severe OSA in obese patients.

Oxidation-Induced Protein Cross-Linking in Mammalian Cells.

A proximity-enabled protein cross-linking strategy with additional spatiotemporal control is highly desirable. Here, we report an oxidation-induced protein cross-linking strategy involving the incorporation of a vinyl thioether group into proteins in both Escherichia coli and mammalian cells via genetic code expansion. We demonstrated that vinyl thioether can be selectively induced by exogenously added oxidant or by reactive oxygen species from the cellular environment, as well as by photocatalysts, and converted into a Michael acceptor, enabling fluorescence labeling and protein cross-linking.

Dexmedetomidine administration during brain tumour resection for prevention of postoperative delirium: a randomised trial.

BACKGROUND: Delirium is common, especially after neurosurgery. Dexmedetomidine might reduce delirium by improving postoperative analgesia and sleep quality. We tested the primary hypothesis that dexmedetomidine administration during intracerebral tumour resection reduces the incidence of postoperative delirium. METHODS: This randomised, double-blind, placebo-controlled trial was conducted in two tertiary-care hospitals in Beijing. We randomised 260 qualifying patients to either dexmedetomidine (n=130) or placebo (n=130). Subjects assigned to dexmedetomidine were given a loading dose of 0.6 µg kg-1 followed by continuous infusion at 0.4 µg kg-1 h-1 until dural closure; subjects in the placebo group were given comparable volumes of normal saline. The primary outcome was the incidence of delirium, which was assessed with the Confusion Assessment Method twice daily during the initial 5 postoperative days. RESULTS: The average (standard deviation) age of participating patients was 45 (12) yr, duration of surgery was 4.2 (1.5) h, and patients assigned to dexmedetomidine were given an average of 126 (45) µg of dexmedetomidine. There was less delirium during the initial 5 postoperative days in patients assigned to dexmedetomidine (22%, 28 of 130 patients) than in those given placebo (46%, 60 of 130 patients) with a risk ratio of 0.51 (95% confidence interval: 0.36-0.74, P<0.001). Postoperative pain scores with movement, and recovery and sleep quality were improved by dexmedetomidine (P<0.001). The incidence of safety outcomes was similar in each group. CONCLUSIONS: Prophylactic intraoperative dexmedetomidine infusion reduced by half the incidence of delirium during the initial 5 postoperative days in patients recovering from elective brain tumour resection. CLINICAL TRIAL REGISTRATION: NCT04674241.

Anwuligan inhibits the progression of non-small cell lung cancer via let-7c-3p/PI3K/AKT/mTOR axis.

BACKGROUND: Anwuligan (ANW) isolated from nutmeg, also known as myristyl lignan, has attracted attention due to its therapeutic potential in diseases. However, its effect on lung cancer is still unclear. METHODS: In this study, the cytotoxicity of ANW on non-small cell lung cancer (NSCLC) cells was detected using a Cell Counting Kit-8 (CCK-8) assay. In vitro, clone formation, wound healing, and Transwell assays were used to investigate the migratory and invasive abilities of NSCLC cells after ANW treatment. The expression levels of the associated proteins were detected using Western blotting. A luciferase assay was used to validate the binding of let-7c-3p to the 3'-untranslated region (UTR) of PIK3CA. In vivo, an A549 cell xenograft mouse model was used to verify the effect of ANW on tumor growth. RESULTS: The results showed that ANW treatment (20 or 50 µM) had obvious cytotoxicity against A549 and H460 cells, suppressing cell proliferation and migration in vitro. In vivo, the growth of the implanted tumor was inhibited by ANW in a nude mouse model. The growth of NSCLC cells was also inhibited by let-7c-3p overexpression in vitro and in vivo. The inhibitory effect of ANW on the proliferation and metastasis of NSCLC cells was weakened by the downregulation of let-7c-3p, whereas it was enhanced by the overexpression of let-7c-3p; PIK3CA was the main target of let-7c-3p. CONCLUSIONS: In summary, ANW inhibits the growth and metastasis of NSCLC cells in vivo and in vitro by upregulating the expression of let-7c-3p, which can regulate the PI3K/AKT/mTOR signaling pathway. PIK3CA is the main target of let-7c-3p.

Living Cell-Target Responsive Accessibility Profiling Reveals Silibinin Targeting ACSL4 for Combating Ferroptosis.

We report a living cell-target responsive accessibility profiling (LC-TRAP) approach to identify the targetome of silibinin (SIL), a well-established hepatoprotective natural product (NP), in HepG2 cells. Proteins showing accessibility changes, probed by covalent lysine labeling reagents and leveraged by multiplexed quantitative proteomics, following the administration of SIL to the living cells were assigned as potential targets. Among the assigned targetome, ACSL4, an enzyme essential for ferroptosis induction, might be involved in the hepatoprotective effects of SIL and hence was intensively validated. We first demonstrated that SIL protected HepG2 cells from ferroptosis dependent on ACSL4. Then, we used biophysical assays and a SIL-derivatized chemical probe to corroborate that SIL can bind to ACSL4. The ensuing enzymatic assays showed that SIL inhibited ACSL4 enzymatic activity, thereby mitigating the ACSL4-mediated ferroptosis. As such, we revealed that ACSL4 inhibition, using SIL as a model compound, represents a promising hepatoprotective strategy. Further, since TRAP probes the accessibility changes of reactive proteinaceous lysines, it can pinpoint the proximal regions where the ligand engagement may occur. Thus, the LC-TRAP analysis of SIL, the newly discovered ligand of ACSL4, and arachidonic acid (AA), the substrate, intriguingly showed that SIL and AA both affected the conformation of the K536-proximal region of ACSL4, albeit through distinct binding patterns. Collectively, we describe a straightforward LC-TRAP workflow that does not involve ligand-derived probe synthesis and is widely applicable to target discovery of NPs.

Effect of anesthesia on the outcome of high-grade glioma patients undergoing supratentorial resection: study protocol for a pragmatic randomized controlled trial.

BACKGROUND: High-grade glioma (HGG) is the most malignant brain tumor with poor outcomes. Whether anesthetic methods have an impact on the outcome of these patients is still unknown. Retrospective study has found no difference between intravenous and inhalation anesthesia on the overall survival (OS) of the HGG patients, however, intravenous anesthesia with propofol might be beneficial in a subgroup of patients with a Karnofsky Performance Status (KPS) Scale less than 80. Further prospective studies are needed to evaluate the results. METHODS: This is a single-centered, randomized controlled, parallel-group trial. Three hundred forty-four patients with primary HGG for tumor resection will be randomly assigned to receive either intravenous anesthesia with propofol or inhalation anesthesia with sevoflurane. The primary outcome is the OS of the patients within 18 months. Secondary outcomes include progression-free survival (PFS), the numerical rating scale (NRS) of pain intensity and sleep quality, the postoperative encephaloedema volume, complications, and the length of hospital stay of the patients. DISCUSSION: This is a randomized controlled trial to compare the effect of intravenous and inhalation anesthesia maintenance on the outcome of supratentorial HGG patients. The results will contribute to optimizing the anesthesia methods in these patients. TRIAL REGISTRATION: ClinicalTrials.gov NCT02756312. Registered on 29 April 2016 and last updated on 9 Sep 2020.

Older Age and Abnormal Pulmonary Ventilation Function Do Not Increase the Risk of Pulmonary Hemorrhage Caused by CT-Guided Percutaneous Core Needle Biopsy.

Purpose: The aim of this study was to analyze the differences in risk factors for pulmonary hemorrhage in elderly and young patients with percutaneous computed tomography-guided needle biopsies (PCNBs). The correlations between the incidence of pulmonary hemorrhage and pulmonary function indicators before CT-guided PCNB were also discussed. Methods: Between January 2018 and December 2019, 1,100 consecutive patients underwent CT-guided PCNBs at Qilu Hospital. Both univariate and multivariate logistic regression analyses identified risk factors for hemorrhage. Results: The occurrence of pulmonary hemorrhage was 22.1% in elderly patients and was 22.6% in young patients. In elderly patients, pulmonary hemorrhage was significantly influenced by needle depth to the lesion and dwell time, while in young patients, pulmonary hemorrhage was independently associated with lesion size, needle depth to the lesion, and dwell time. However, pulmonary function parameters, including FVC (% pred), FEV1 (% pred), FEV1/FVC ratio (%), small airway function parameters (FEF50%, FEF75%, and FEF25-75%), and large airway function parameters (MVV, PEF, and FEF25%), were not risk factors for hemorrhage. Furthermore, the incidence of pulmonary hemorrhage was not associated with different types of pulmonary dysfunctions. The risk of pulmonary hemorrhage did not increase with the severity of pulmonary dysfunctions. Conclusions: In this study, age is no longer a risk factor in evaluating pulmonary hemorrhage. Longer needle depth to the lesion and longer dwell time were significantly high risk factors of hemorrhage in both elderly patients and young patients. Patients with severe pulmonary dysfunctions did not show increased risks of pulmonary hemorrhage here.

Consistent Plant and Microbe Nutrient Limitation Patterns During Natural Vegetation Restoration.

Vegetation restoration is assumed to enhance carbon (C) sequestration in terrestrial ecosystems, where plant producers and microbial decomposers play key roles in soil C cycling. However, it is not clear how the nutrient limitation patterns of plants and soil microbes might change during vegetation restoration. We investigated the nutrient limitations of the plant and microbial communities along a natural vegetation restoration chronosequence (1, 8, 16, 31, and 50 years) following farmland abandonment in Qinling Mountains, China, and assessed their relationships with soil factors. The result showed that following natural vegetation restoration, the nitrogen (N) limitation of plant and microbial communities was alleviated significantly, and thereafter, it began to shift to phosphorus (P) limitation at a later stage. Plants showed P limitation 50 years after restoration, while microbial P limitation appeared 31 years later. The changes in plant nutrient limitation were consistent with those in microbial nutrient limitation, but soil microbes were limited by P earlier than plants. Random forest model and partial least squares path modeling revealed that soil nutrient stoichiometry, especially soil C:N ratio, explained more variations in plant and microbial nutrient limitation. Our study demonstrates that the imbalanced soil C:N ratio may determine the soil microbial metabolic limitation and further mediate the variation in plant nutrient limitation during natural vegetation restoration, which provides important insights into the link between metabolic limitation for microbes and nutrient limitation for plants during vegetation restoration to improve our understanding of soil C turnover in temperate forest ecosystems.

Elevated ß-catenin and C-myc promote malignancy, relapse, and indicate poor prognosis in patients with relapsed glioma.

Context: Extensive studies have shown that ß-catenin and C-myc have been linked to a number of human cancers. However, the role of ß-catenin and C-myc in relapse glioma remains unclear. Aims: The aims of this study were to investigate the role of ß-catenin and C-myc in relapsed glioma patients and to explore the possible impact of malignancy, relapse, and prognosis. Materials and Methods: We collected surgical samples of 100 patients with primary and relapsed glioma treated at our institution. Immunohistochemistry (IHC) staining was used to evaluate the expressions of ß-catenin and C-myc. The impact of the differences on disease-free interval (DFI), initial overall survival (iOS), and overall survival from the time of glioma relapse (rOS) of the patients was analyzed. Kaplan-Meier survival functions were used to plot survival time, and a log-rank test was used for analyzing statistical significance. Cox multivariate regression analysis was used to determine independent prognostic parameters. Results: Compared to primary tumors, relapsed gliomas had higher expressions of ß-catenin and C-myc (P < 0.05). Furthermore, the expressions of ß-catenin and C-myc were significantly correlated with glioma grade (P < 0.05). These changes in expression at the time of relapse were independent of radiotherapy use. In multivariate Cox analysis, we found that ß-catenin and C-myc were independent prognostic factors for rOS (P < 0.05). Conclusions: Elevated ß-catenin and C-myc promote malignancy, relapse, and indicate poor prognosis in patients with relapsed glioma. The elevated levels of ß-catenin and c-myc in relapsed glioma were not affected by radiation therapy. The results of this study may provide a new therapeutic target for patients with relapsed glioma.

Ultrasound-guided superficial cervical plexus block reduces opioid consumption in patients undergoing craniotomy via suboccipital retrosigmoid approach: a randomized controlled trial.

INTRODUCTION: The effectiveness of superficial cervical plexus block (SCPB) at decreasing opioid use and improving hemodynamic stability during suboccipital retrosigmoid craniotomy has not been established. The aim of this study is to evaluate the analgesic effect of preoperative ultrasound-guided SCPB for craniotomy via a suboccipital retrosigmoid approach. METHODS: This was a prospective, single-center, randomized, double-blind, parallel-group controlled trial. One hundred and six adult patients undergoing suboccipital retrosigmoid craniotomy were randomly allocated into either the SCPB group (n=53) to receive 10 mL of 0.5% ropivacaine or the control group (n=53) to receive 0.9% normal saline injected into the superficial layer of prevertebral fascia guided by ultrasound. The primary outcome was the cumulative consumption of sufentanil with patient-controlled intravenous analgesia (PCIA) within 24 hours. Secondary outcomes included the overall perioperative consumption of opioids, the area under the curve of the pain score from 1 hour to 48 hours (AUC1-48), intraoperative hemodynamic parameters, and anesthesia depth. RESULTS: The mean PCIA pump cumulative consumption of sufentanil in the first 24 hour postoperative period was significantly lowered by SCPB (5.0 µg vs 9.8 µg, 95% CI: -8.0 to -2.4; p=0.001). The total perioperative consumption of sufentanil (45.0 µg vs 54.5 µg, 95% CI: -14.8 to -4.1; p=0.001) was also significantly decreased by SCPB. The incidence of severe pain within 24 hours was decreased by SCPB (7.5% vs 26.4%, p=0.01). SCPB significantly decreased the AUC1-48 of the pain score. Intraoperative hemodynamic parameters and anesthesia depth were similar between groups (p>0.05). DISCUSSION: SCPB provides effective analgesia in patients undergoing craniotomy and tumor resection via suboccipital retrosigmoid approach. SCPB demonstrates an opioid-sparing effect and allows for the maintenance hemodynamic stability at an appropriate depth of anesthesia. TRIAL REGISTRATION NUMBER: NCT04036812.

Cyclic immonium ion of lactyllysine reveals widespread lactylation in the human proteome.

Lactylation was initially discovered on human histones. Given its nascence, its occurrence on nonhistone proteins and downstream functional consequences remain elusive. Here we report a cyclic immonium ion of lactyllysine formed during tandem mass spectrometry that enables confident protein lactylation assignment. We validated the sensitivity and specificity of this ion for lactylation through affinity-enriched lactylproteome analysis and large-scale informatic assessment of nonlactylated spectral libraries. With this diagnostic ion-based strategy, we confidently determined new lactylation, unveiling a wide landscape beyond histones from not only the enriched lactylproteome but also existing unenriched human proteome resources. Specifically, by mining the public human Meltome Atlas, we found that lactylation is common on glycolytic enzymes and conserved on ALDOA. We also discovered prevalent lactylation on DHRS7 in the draft of the human tissue proteome. We partially demonstrated the functional importance of lactylation: site-specific engineering of lactylation into ALDOA caused enzyme inhibition, suggesting a lactylation-dependent feedback loop in glycolysis.

Contrasting dynamics and factor controls in leaf compared with different-diameter fine root litter decomposition in secondary forests in the Qinling Mountains after 5 years of whole-tree harvesting.

Plant litter decomposition is a crucial pathway for carbon (C) and nutrient cycling, and controls the net primary productivity in ecosystems worldwide. However, little is known about how multi-type litter (leaf and different diameter fine roots) decomposition rates and nutrient release change at the community level following whole-tree harvesting (WTH). In the present study, we followed decomposition of leaf and different diameter fine root (∅ < 0.5 mm, 0.5-1 mm, 1-2 mm) litters at plot level over 2 years in a secondary forest in the Qinling Mountains after 5 years of five different thinning treatments (0%, 15%, 30%, 45%, and 60%). Our results demonstrated that WTH had no effects on leaf and different diameter fine root litter decomposition at the plot level. Leaves had significantly higher decomposition rate than different diameter fine roots. There were significant positive correlations between decomposition rate of different diameter fine roots, but not related to leaf litter decomposition rate. WTH did not affect the nutrient release of leaf and different diameter fine root litters at the plot level. The nitrogen (N), phosphorous (P) and potassium (K) mass remaining in leaf litters were significantly higher than different diameter fine roots after 2 years decomposition, while different diameter fine roots had higher C mass remaining. Leaf and fine root litter decomposition rates were mainly influenced by stand and litter quality attributes. Nutrient release of leaf and fine root N, P and K were mainly predicted by litter quality characteristics, while there were no consistent driving factors for C release. Our results suggested that WTH had no effects on multi-type litter decomposition and nutrient release at plot level after 5 years of recovery. Moreover, leaf litters had excellent N, P and K nutrient preservation mechanisms, and C conservation in fine root litters.

Responses of Fine Roots at Different Soil Depths to Different Thinning Intensities in a Secondary Forest in the Qinling Mountains, China.

Fine roots make critical contributions to carbon stocks and terrestrial productivity, and fine roots with different diameters exhibit functional heterogeneity. However, the changed characteristics of fine roots with different diameters at different soil depths following thinning disturbances are poorly understood. We investigated the biomass, production, mortality and turnover rate of <0.5 mm, 0.5−1 mm, and 1−2 mm fine roots at 0−20 cm, 20−40 cm, and 40−60 cm soil depths under five thinning intensities (0%, 15%, 30%, 45%, and 60%) in a secondary forest in the Qinling Mountains. The biomass, production and turnover rate of <0.5 mm fine roots fluctuated with increasing thinning intensities, while the 0.5−1 mm and 1−2 mm fine-root biomass significantly decreased. The thinning intensities had no effects on the fine-root necromass or mortality. The change in the fine-root characteristics in deeper soils was more sensitive to the thinning intensities. The principal component analysis results showed that increased <0.5 mm fine-root biomass and production resulted from increased shrub and herb diversity and biomass and decreased soil nutrient availability, stand volume, and litter biomass, whereas the 0.5−1 mm and 1−2 mm fine-root biomass showed the opposite trends and changes. Our results suggest that different thinning intensities exhibit varied influential mechanisms on the changed characteristics of fine roots with different diameters.

Zingerone Inhibits the Neutrophil Extracellular Trap Formation and Protects against Sepsis via Nrf2-Mediated ROS Inhibition.

Neutrophils release chromatin and antimicrobial proteins to trap and kill microbes, which is termed as neutrophil extracellular trap (NET) formation. NETs play a pivotal role in host defense against infection. However, emerging evidence indicated that NETs also contribute to an exaggerated inflammatory response and organic injuries in sepsis. Zingerone, a natural compound extracted from Zingiber officinale, exerts antioxidant, anti-inflammatory, and antioncogenic properties. In this study, we found that treatment with zingerone reduced organ injury and improved the outcome in a cecal ligation puncture- (CLP-) induced polymicrobial sepsis model. Administration of zingerone also alleviates reactive oxygen species (ROS) accumulation and systematic inflammation in septic mice and inhibits neutrophil extracellular traps (NETs) formation in vivo and in vitro. Furthermore, inhibition of nuclear factor erythroid 2-related factor 2 (Nrf2) with its specific antagonist significantly counteracted the suppressive effects of zingerone on ROS and NETs and retarded the protective role of zingerone against sepsis-associated organ injury. In addition, exposure to zingerone does not affect phagocytic activity of neutrophils in vitro and bacterial dissemination in vivo. Above all, our results indicate that zingerone treatment obviously attenuates NET formation and inflammatory response via Nrf2-mediated ROS inhibition, thus providing a novel therapeutic strategy against sepsis-induced injury.

[Extracellular Enzyme Stoichiometry and Microbial Metabolism Limitation During Vegetation Restoration Process in the Middle of the Qinling Mountains, China].

Clarifying the characteristics of soil microbial nutrient limitation and its driving mechanisms during vegetation restoration after farmland abandonment has important implications for revealing soil nutrient cycling and maintaining ecosystem stability. To determine the limitation of soil microbial nutrients and its relationship with soil properties along a chronosequence of abandoned farmland in the middle of the Qinling Mountains, the soil physicochemical properties and five enzyme activities (ß-1,4-glucosidase (BG), cellobiohydrolase (CBH), ß-1,4-N-acetylglucosaminidase (NAG), leucine aminopeptidase (LAP), and acid phosphatase (AP)) were measured, and models of extracellular enzymatic activity were applied. The results showed that the activities of BG, CBH, NAG, LAP, and AP were significantly increased following farmland abandonment. With the increasing years of abandonment, the ratios of (BG+CBH)/(NAG+LAP) and (BG+CBH)/AP significantly decreased, whereas the ratio of (NAG+LAP)/AP increased. Correlation analysis showed that most soil physicochemical properties were significantly correlated with extracellular enzyme activities and extracellular enzymatic stoichiometry. The vector length of extracellular enzymatic stoichiometry decreased with the increase in abandonment years, indicating that the limitation of soil microorganisms on carbon (C) was reduced. Moreover, the vector angles (>45°) showed a decreasing trend, indicating that microbial metabolisms were limited by phosphorus (P) and gradually decreased. Regression analysis showed that the C and P limitations were significantly related to total nutrients, available nutrients, nutrient ratio, and soil physical properties. Partial least squares path modeling (PLS-PM) revealed that the C and P limitations were directly regulated by nutrient ratio. PLS-PM further showed that soil total nutrients indirectly affected soil microbial C and P limitations by affecting nutrient ratio, and nutrient ratio affected the soil metabolism limitation via available nutrients and pH. Our study suggests that the characteristics of microbial metabolism during the vegetation restoration process reflect the mechanism of microorganism-mediated soil nutrient cycling, which provides a theoretical basis for revealing the community dynamics and stability during the vegetation restoration process and maintaining the regional ecological environment security in the Qinling Mountains.

Risk of pneumothorax caused by computerized tomography-guided percutaneous core needle biopsy of the lung in elderly and young patients.

CONTEXT: The incidences and risk factors caused by computed tomography (CT)-guided percutaneous computed tomography-guided needle biopsies (PCNBs) in elderly and young patients were not very clear. AIMS: This study explored the different incidences of pneumothorax caused by PCNBs and related risk factors in elderly and young patients. SETTINGS AND DESIGN: The medical records of 1100 patients who underwent CT-guided PCNBs in a hospital from January 2018 to December 2019 were retrospectively reviewed. SUBJECTS AND METHODS: Data relating to the patients, lesions, techniques, and diagnoses were collected according to the ethical standards of the institutional research committee (registration number: KYLL-202008-145). STATISTICAL ANALYSIS USED: The variables were significant by univariate analysis and further analyzed by multivariate logistic regression analysis. RESULTS: In the 1100 patients with PCNBs, the incidence of pneumothorax in groups ≥65 years old and <65 years old was 15.2% and 12.9%, respectively. There was no significant difference in the incidence of pneumothorax between the young and elderly patients. In elderly and young patients, emphysema along the needle path and dwell time was independent predictors. However, in young patients, lesion-abutting pleura was an independent risk factor for pneumothorax, but not in elderly patients. CONCLUSIONS: The risk of pneumothorax caused by CT-guided percutaneous core needle biopsy of the lung does not increase in elderly patients. Emphysema along the needle path and dwell time is independent predictors of pneumothorax in elderly and young patients.