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1.
J Physiol ; 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38953534

RESUMO

The central histaminergic system has a pivotal role in emotional regulation and psychiatric disorders, including anxiety, depression and schizophrenia. However, the effect of histamine on neuronal activity of the centrolateral amygdala (CeL), an essential node for fear and anxiety processing, remains unknown. Here, using immunostaining and whole-cell patch clamp recording combined with optogenetic manipulation of histaminergic terminals in CeL slices prepared from histidine decarboxylase (HDC)-Cre rats, we show that histamine selectively suppresses excitatory synaptic transmissions, including glutamatergic transmission from the basolateral amygdala, on both PKC-δ- and SOM-positive CeL neurons. The histamine-induced effect is mediated by H3 receptors expressed on VGLUT1-/VGLUT2-positive presynaptic terminals in CeL. Furthermore, optoactivation of histaminergic afferent terminals from the hypothalamic tuberomammillary nucleus (TMN) also significantly suppresses glutamatergic transmissions in CeL via H3 receptors. Histamine neither modulates inhibitory synaptic transmission by presynaptic H3 receptors nor directly excites CeL neurons by postsynaptic H1, H2 or H4 receptors. These results suggest that histaminergic afferent inputs and presynaptic H3 heteroreceptors may hold a critical position in balancing excitatory and inhibitory synaptic transmissions in CeL by selective modulation of glutamatergic drive, which may not only account for the pathophysiology of psychiatric disorders but also provide potential psychotherapeutic targets. KEY POINTS: Histamine selectively suppresses the excitatory, rather than inhibitory, synaptic transmissions on both PKC-δ- and SOM-positive neurons in the centrolateral amygdala (CeL). H3 receptors expressed on VGLUT1- or VGLUT2-positive afferent terminals mediate the suppression of histamine on glutamatergic synaptic transmission in CeL. Optogenetic activation of hypothalamic tuberomammillary nucleus (TMN)-CeL histaminergic projections inhibits glutamatergic transmission in CeL via H3 receptors.

2.
Hepatol Int ; 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38965190

RESUMO

BACKGROUND AND AIMS: The risk of hepatocellular carcinoma (HCC) occurrence following antiviral therapy in patients with chronic hepatitis C (CHC) remains unclear. The current study aims to compare: (1) the HCC occurrence rate following sustained virological response (SVR) versus non-response (NR); (2) the HCC occurrence rate following direct-acting antiviral (DAA) therapy versus interferon (IFN)-based therapy, and (3) the HCC occurrence rate in SVR patients with or without cirrhosis. METHODS: A search was performed for articles published between January 2017 and July 2022. Studies were included if they assessed HCC occurrence rate in CHC patients following anti-HCV therapy. Random effects meta-analysis was used to synthesize the results from individual studies. RESULTS: A total of 23 studies including 29,395 patients (IFN-based = 6, DAA = 17; prospective = 10, retrospective = 13) were included in the review. HCC occurrence was significantly lower in CHC with SVR (1.54 per 100 person-years (py, 95% CI 1.52, 1.57) than those in non-responders (7.80 py, 95% CI 7.61, 7.99). Stratified by HCV treatment regimens, HCC occurrence following SVR was 1.17 per 100 py (95% CI 1.11, 1.22) and 1.60 per 100 py (95% CI 1.58, 1.63) in IFN- and DAA treatment-based studies. HCC occurrence was 0.85 per 100 py (95% CI 0.85, 0.86) in the non-cirrhosis population and rose to 2.47 per 100 py (95% CI 2.42, 2.52) in the cirrhosis population. Further meta-regression analysis showed that treatment types were not associated with a higher HCC occurrence rate, while cirrhosis status was an important factor of HCC occurrence rate. CONCLUSION: HCC occurrence was significantly lower in the SVR population than in the NR population. HCC risk following SVR occurred three times more frequently in patients with cirrhosis than patients without cirrhosis. However, we found no significant difference in HCC occurrence risk following SVR between DAA and IFN therapies. CLINICAL TRIAL NUMBER: CRD42023473033.

3.
J Asian Nat Prod Res ; : 1-9, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38963070

RESUMO

Five new glycosides, namely methyl 3-methoxybenzoate-4,5-di-O-ß-D-glucopyranoside (1), (1aS,3aS,3R)-3-(4'-O-ß-D-glucopyranosyl-3'-methoxyphenyl)-5,6-dioxa-bicyclo[3.3.0]octane-1-one (2), quinolin-4(1H)-one-3-O-ß-D-glucopyranoside (3), 3-methoxy-propiophenone 4-O-(6'-ß-D-xylopyranosyl)-ß-D-glucopyranoside (4), methyl 3-methoxybenzoate 4-O-(6'-ß-D-xylopyranosyl)-ß-D-glucopyranoside (5), and one known compound, bambulignan B (6) were isolated from the culms of Phyllostachys nigra var. henonis. Their structures were determined using spectroscopic analysis. All compounds were evaluated for their DPPH radical scavenging activity. Compound 6 exhibited antioxidant activity with IC50 value of 59.5 µM (positive control, L-ascorbic acid, IC50 = 12.4 µM; 2,6-ditertbutyl-4-methyl phenol, IC50 = 11.8 µM).

4.
Sci Rep ; 14(1): 16749, 2024 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-39033195

RESUMO

The triglyceride-glucose (TyG) index is a novel marker of insulin resistance that has been strongly associated with many diseases related to metabolic disorders, such as diabetes, coronary heart disease, myocardial infarction, obesity, nonalcoholic fatty liver disease, and stroke. However, whether the TyG index is associated with the prevalence of gallstones has not been determined. Therefore, the purpose of this study was to evaluate the relationship between the TyG index and the prevalence of gallstones in American adults, as well as the age at which adults in America undergo their first gallstone surgery. We selected individuals from the National Health and Nutrition Examination Survey (NHANES) database from 2017 to March 2020. Based on the goal of our study, comprehensive inclusion and exclusion criteria were created. A logistic regression analysis, dose-response curve, and subgroup analysis were computed to assess the relationship between the TyG index and gallstone prevalence and age at first surgery for gallstone. A total of 3905 participants aged > 20 years were included in our study, of whom 421 had a self-reported history of gallstones. A total of 1884 (48.2%) males and 2021 (51.8%) females were included. After confounders adjustment, it was found single-unit increases in the TyG index were linked with a 25.0% increase in gallstone prevalence (odds ratio [OR] = 1.25, 95% confidence interval [95%CI]: 1.04, 1.51). After conversion of the TyG index values from continuous to categorical variables with tertiles, a marked 48% increase in gallstone incidence was found in tertile 3 relative to tertile 1 (OR = 1.48, 95% CI: 1.09, 1.99). The dose-response curve results indicated positive associations between gallstone prevalence and the TyG index, while the latter was negatively associated with age at first gallstone surgery. Based on subgroup analysis, the positive association between TyG index and high-incidence of gallstones was more significant in females (OR = 1.39, 95% CI: 1.09, 1.77), age < 40 years (OR = 2.02, 95% CI: 1.23, 3.29), and other race (OR = 1.46, 95% CI: 1.06, 2.02). A higher TyG index is associated with a higher incidence of gallstones and may lead to an earlier age of first gallstone surgery. However, a causal relationship between TyG and gallstones cannot be established.


Assuntos
Glicemia , Cálculos Biliares , Triglicerídeos , Humanos , Cálculos Biliares/cirurgia , Cálculos Biliares/epidemiologia , Cálculos Biliares/sangue , Feminino , Masculino , Adulto , Triglicerídeos/sangue , Pessoa de Meia-Idade , Prevalência , Estados Unidos/epidemiologia , Glicemia/análise , Glicemia/metabolismo , Inquéritos Nutricionais , Idoso , Fatores Etários , Adulto Jovem , Resistência à Insulina
5.
Am Surg ; : 31348241265147, 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39030672

RESUMO

OBJECTIVE: To evaluate the safety study of percutaneous gastroscopic gastrostomy in patients after ventriculoperitoneal shunt. METHODS: We conducted a retrospective analysis of neurosurgical patients who underwent VPS and PEG at our hospital between January 2012 and November 2023. Patients were divided into 2 groups: VPS group and VPS followed by PEG gruop. Patients received routine antibiotic prophylaxis before the procedure, continued for 48 hours. Follow-up included monitoring immediate complications, particularly wound infection, intracranial infection, neurologic status deterioration, and shunt dysfunction. Routine follow-up visits were conducted post-discharge. RESULTS: In the VPS group (n = 778), the incidence of intracranial infection was 3.08%. Among patients with PEG after VPS, the time interval between procedures ranged from 13 to 685 days. The mean follow-up period was 22 (1-77) months, with no deaths or further complications. CONCLUSION: Performing PEG more than 13 days after VPS does not significantly increase the risk of intracranial infections or PEG-associated infections, making it a relatively safe procedure.

6.
Mol Ecol ; 33(15): e17442, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38953280

RESUMO

Climate change is altering species distribution and modifying interactions in microbial communities. Understanding microbial community structure and their interactions is crucial to interpreting ecosystem responses to climate change. Here, we examined the assemblages of stream bacteria and fungi, and the associations between the two groups along elevational gradients in two regions with contrasting precipitation and temperature, that is the Galong and Qilian mountains of the Tibetan Plateau. In the wetter and warmer region, the species richness significantly increased and decreased with elevation for bacteria and fungi, respectively, while were nonsignificant in the drier and colder region. Their bipartite network structure was also different by showing significant increases in connectance and nestedness towards higher elevations only in the wetter and warmer region. In addition, these correlation network structure generally exhibited similar positive association with species richness in the wetter and warmer region and the drier and colder region. In the wetter and warmer region, climatic change along elevation was more important in determining connectance and nestedness, whereas microbial species richness exerted a stronger influence on network structure and robustness in the drier and colder region. These findings indicate substantial forthcoming changes in microbial diversity and network structure in warming climates, especially in wetter and warmer regions on Earth, advancing the understanding of microbial bipartite interactions' response to climate change.


Assuntos
Altitude , Bactérias , Mudança Climática , Fungos , Bactérias/classificação , Bactérias/genética , Fungos/genética , Fungos/classificação , Tibet , Microbiota , Ecossistema , Biodiversidade , Clima , Rios/microbiologia
7.
Int J Mol Sci ; 25(13)2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-39000188

RESUMO

Premature leaf senescence significantly reduces rice yields. Despite identifying numerous factors influencing these processes, the intricate genetic regulatory networks governing leaf senescence demand further exploration. We report the characterization of a stably inherited, ethyl methanesulfonate(EMS)-induced rice mutant with wilted leaf tips from seedling till harvesting, designated lts2. This mutant exhibits dwarfism and early senescence at the leaf tips and margins from the seedling stage when compared to the wild type. Furthermore, lts2 displays a substantial decline in both photosynthetic activity and chlorophyll content. Transmission electron microscopy revealed the presence of numerous osmiophilic granules in chloroplast cells near the senescent leaf tips, indicative of advanced cellular senescence. There was also a significant accumulation of H2O2, alongside the up-regulation of senescence-associated genes within the leaf tissues. Genetic mapping situated lts2 between SSR markers Q1 and L12, covering a physical distance of approximately 212 kb in chr.1. No similar genes controlling a premature senescence leaf phenotype have been identified in the region, and subsequent DNA and bulk segregant analysis (BSA) sequencing analyses only identified a single nucleotide substitution (C-T) in the exon of LOC_Os01g35860. These findings position the lts2 mutant as a valuable genetic model for elucidating chlorophyll metabolism and for further functional analysis of the gene in rice.


Assuntos
Clorofila , Mutação , Oryza , Folhas de Planta , Oryza/genética , Oryza/metabolismo , Oryza/crescimento & desenvolvimento , Folhas de Planta/genética , Folhas de Planta/metabolismo , Clorofila/metabolismo , Senescência Vegetal/genética , Mapeamento Cromossômico , Fenótipo , Regulação da Expressão Gênica de Plantas , Fotossíntese/genética , Genes de Plantas , Peróxido de Hidrogênio/metabolismo
8.
Physiol Plant ; 176(4): e14432, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38981735

RESUMO

WRKYs play important roles in plant stress resistance. However, the role of WRKYs in non-heading Chinese cabbage (Brassica campestris ssp. chinensis) against Botrytis cinerea (B. cinerea) remains poorly understood. Herein, the expression of BcWRKY1 was induced by B. cinerea. Further, the role of BcWRKY1 in B. cinerea infection was identified. Silencing of BcWRKY1 in non-heading Chinese cabbage enhanced plant resistance to B. cinerea. After B. cinerea inoculation, BcWRKY1-silencing plants exhibited lower reactive oxygen species (ROS) content, higher jasmonic acid (JA) content, and the expression level of JA biosynthesis genes, BcOPR3, BcLOX3-1 and BcLOX3-2 were upregulated. Overexpression of BcWRKY1 in Arabidopsis exhibited a complementary phenotype. By directly targeting W-boxes in the promoter of BcLOX3-2, BcWRKY1 inhibited the transcription of this gene. In addition, 13 candidate interacting proteins of BcWRKY1 were identified by yeast two-hybrid (Y2H) screening, and the interaction between BcWRKY1 and BcCaM6 weakened the inhibition of BcLOX3-2. In summary, our findings suggest that BcWRKY1 interacts with BcCaM6 to negatively regulate disease resistance.


Assuntos
Botrytis , Brassica , Ciclopentanos , Resistência à Doença , Regulação da Expressão Gênica de Plantas , Oxilipinas , Doenças das Plantas , Proteínas de Plantas , Botrytis/fisiologia , Botrytis/patogenicidade , Ciclopentanos/metabolismo , Doenças das Plantas/microbiologia , Doenças das Plantas/genética , Oxilipinas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Resistência à Doença/genética , Brassica/microbiologia , Brassica/genética , Brassica/metabolismo , Arabidopsis/microbiologia , Arabidopsis/genética , Arabidopsis/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Plantas Geneticamente Modificadas
9.
Biomed Pharmacother ; 177: 117100, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39013221

RESUMO

Gastric cancer (GC) is the fifth most prevalent type of cancer in the whole world. Cuproptosis is discovered as a programmed cell death pathway and connected to cells' growth and death, as well as tumorigenesis. The relationship between cuproptosis and GC is still elusive. Two aspects of this study will elaborate the relationship between cuproptosis and immunotherapy as well as biomarkers in GC. Notably, the herein review is intended to highlight what has been accomplished regarding the cuproptosis for the diagnosis, immunotherapy, and prognosis in GC. The aim of this study is to offer a potential directions and the strategies for future research regarding cuproptosis inside the GC.

10.
Front Endocrinol (Lausanne) ; 15: 1392466, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38911042

RESUMO

Background: The onset and progression of chronic kidney disease (CKD) has been linked to metabolic syndrome (MetS), with the results of recent observational studies supporting a potential link between renal failure and MetS. The causal nature of this relationship, however, remains uncertain. This study thus leveraged a Mendelian Randomization (MR) approach to probe the causal link of MetS with renal failure. Methods: A genetic database was initially used to identify SNPs associated with MetS and components thereof, after which causality was evaluated through the inverse variance weighted (IVW), MR-Egger regression, and weighted media techniques. Results were subsequently validated through sensitivity analyses. Results: IVW (OR = 1.48, 95% CI = 1.21-1.82, P =1.60E-04) and weighted median (OR = 1.58, 95% CI =1.15-2.17, P = 4.64E-03) analyses revealed that MetS was linked to an elevated risk of renal failure. When evaluating the specific components of MetS, waist circumference was found to be causally related to renal failure using the IVW (OR= 1.58, 95% CI = 1.39-1.81, P = 1.74e-11), MR-Egger (OR= 1.54, 95% CI = 1.03-2.29, P = 0.036), and weighted median (OR= 1.82, 95% CI = 1.48-2.24, P = 1.17e-8). The IVW method also revealed a causal association of hypertension with renal failure (OR= 1.95, 95% CI = 1.34-2.86, P = 5.42e-04), while renal failure was not causally related to fasting blood glucose, triglyceride levels, or HDL-C levels. Conclusion: These data offer further support for the existence of a causal association of MetS with kidney failure. It is thus vital that MetS be effectively managed in patients with CKD in clinical settings, particularly for patients with hypertension or a high waist circumference who are obese. Adequate interventions in these patient populations have the potential to prevent or delay the development of renal failure.


Assuntos
Análise da Randomização Mendeliana , Síndrome Metabólica , Polimorfismo de Nucleotídeo Único , Humanos , Síndrome Metabólica/genética , Síndrome Metabólica/complicações , Masculino , Feminino , Insuficiência Renal/genética , Pessoa de Meia-Idade , Circunferência da Cintura , Fatores de Risco
11.
Front Immunol ; 15: 1413947, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38881887

RESUMO

CD36 is a scavenger receptor that has been reported to function as a signaling receptor that responds to pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) and could integrate metabolic pathways and cell signaling through its dual functions. Thereby influencing activation to regulate the immune response and immune cell differentiation. Recent studies have revealed that CD36 plays critical roles in the process of lipid metabolism, inflammatory response and immune process caused by Mycobacterium tuberculosis infection. This review will comprehensively investigate CD36's functions in lipid uptake and processing, inflammatory response, immune response and therapeutic targets and biomarkers in the infection process of M. tuberculosis. The study also raised outstanding issues in this field to designate future directions.


Assuntos
Antígenos CD36 , Mycobacterium tuberculosis , Tuberculose , Humanos , Antígenos CD36/metabolismo , Mycobacterium tuberculosis/imunologia , Tuberculose/imunologia , Tuberculose/metabolismo , Tuberculose/microbiologia , Animais , Metabolismo dos Lipídeos , Transdução de Sinais , Biomarcadores , Interações Hospedeiro-Patógeno/imunologia
12.
Molecules ; 29(12)2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38930848

RESUMO

The photoelectrochemical (PEC) conversion of organic small molecules offers a dual benefit of synthesizing value-added chemicals and concurrently producing hydrogen (H2). Ethylene glycol, with its dual hydroxyl groups, stands out as a versatile organic substrate capable of yielding various C1 and C2 chemicals. In this study, we demonstrate that pH modulation markedly enhances the photocurrent of BiVO4 photoanodes, thus facilitating the efficient oxidation of ethylene glycol while simultaneously generating H2. Our findings reveal that in a pH = 1 ethylene glycol solution, the photocurrent density at 1.23 V vs. RHE can attain an impressive 7.1 mA cm-2, significantly surpassing the outputs in neutral and highly alkaline environments. The increase in photocurrent is attributed to the augmented adsorption of ethylene glycol on BiVO4 under acidic conditions, which in turn elevates the activity of the oxidation reaction, culminating in the maximal production of formic acid. This investigation sheds light on the pivotal role of electrolyte pH in the PEC oxidation process and underscores the potential of the PEC strategy for biomass valorization into value-added products alongside H2 fuel generation.

13.
BMC Pediatr ; 24(1): 414, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38926645

RESUMO

BACKGROUND: Guillain‒Barre syndrome (GBS) is an acute inflammatory peripheral neuropathy caused by autoimmunity. Gangliosides and sulfatides are important components of peripheral nerves. Anti-sulfatide antibody-mediated complement is associated with acute sensorimotor peripheral neuropathy in GBS, which is characterized by pain and paresthesias. CASE PRESENTATION: The child was a 7-year-old girl with headache and abdominal pain, followed by limb numbness and pain. Cranial imaging showed ventricular dilatation, peripheral nerve function conduction examination showed polyradiculopathy, and cerebrospinal fluid tests showed normal cell counts but elevated protein levels, all of which led to the diagnosis of GBS. After treatment with intravenous immunoglobulin (400 mg/kg × 5 days), the symptoms did not improve, and muscle strength progressively worsened, accompanied by paroxysmal complexion flushing, heart rate fluctuation, hyperhidrosis, and a progressive increase in cerebrospinal fluid protein (up to 3780.1 mg/L). On the basis of these findings combined with serum anti-sulfatide IgM positivity, anti-sulfatide antibody-related GBS was considered, and treatment with low-dose prednisolone (1 mg/kg/d) led to symptom improvement. CONCLUSIONS: Anti-sulfatide antibody-associated GBS is associated with small fiber peripheral neuropathy. The main manifestations are pain, paresthesias and autonomic dysfunction. In addition to the dysfunction of spinal nerve root absorption caused by increased cerebrospinal fluid protein, autonomic dysfunction may be involved in pain. When the therapeutic effect of immunoglobulin is not satisfactory, a low dose and short course of corticosteroids can be considered, and the prognosis is good.


Assuntos
Dor Abdominal , Síndrome de Guillain-Barré , Cefaleia , Sulfoglicoesfingolipídeos , Humanos , Feminino , Criança , Síndrome de Guillain-Barré/diagnóstico , Síndrome de Guillain-Barré/tratamento farmacológico , Dor Abdominal/etiologia , Cefaleia/etiologia , Cefaleia/tratamento farmacológico , Sulfoglicoesfingolipídeos/imunologia , Autoanticorpos/sangue , Prednisolona/uso terapêutico
14.
Biochim Biophys Acta Mol Cell Res ; 1871(7): 119785, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38885843

RESUMO

We previously reported that integrin alpha 7 (ITGA7) was downregulated in colorectal cancer (CRC) tissues and CRC cell lines and that the lower expression of ITGA7 in CRC tissues was correlated with distant metastasis, suggesting that ITGA7 may function as a suppressor in CRC. The present research was conducted to further investigate the role and mechanisms of ITGA7 in CRC progression. First, bisulfite modification and genomic sequencing (BSP) results showed that the methylation rate of ITGA7 promoter was higher in 10 CRC tissues than in the matched normal tissues. Additionally, 5-Aza-CdR treatment increased ITGA7 expression in CRC cells. Gain-of-function assays revealed the inhibitory role of ITGA7 in CRC cell proliferation and migration. Mechanistically, RNA sequencing, RT-qPCR, and cytoplasm and nuclear separation and rescue assays indicated that knockdown of ITGA7 activated the transcription of MMP9, SETD7, and ADAM15 by enhancing the nuclear translocation of NF-κB. Moreover, CoIP and Western blot suggested a mechanistic model in which ITGA7 binds to CKAP4 to block the interaction of CKAP4 and PI3K p85α and thereby suppress the PI3K/AKT/NF-κB pathway. Accordingly, the current study suggests that ITGA7 functions as a suppressor in CRC progression and that its expression is controlled by promoter methylation.

15.
Biomed Pharmacother ; 177: 117030, 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38917759

RESUMO

Ferroptosis is a lipid peroxidation-driven and iron-dependent form of programmed cell death, which is involved in a variety of physical processes and multiple diseases. Numerous reports have demonstrated that ferroptosis is closely related to the pathophysiological processes of Mycobacterium tuberculosis (M. tuberculosis) infection and is characterized by the accumulation of excess lipid peroxides on the cell membrane. In this study, the various functions of ferroptosis, and the therapeutic strategies and diagnostic biomarkers of tuberculosis, were summarized. Notably, this review provides insights into the molecular mechanisms and functions of M. tuberculosis-induced ferroptosis, suggesting potential future therapeutic and diagnostic markers for tuberculosis.

16.
Environ Res ; 255: 119206, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38782346

RESUMO

Climate warming is a pressing global issue with substantial impacts on soil health and function. However, the influence of environmental context on the responses of soil microorganisms to warming remains largely elusive, particularly in alpine ecosystems. This study examined the responses of the soil microbiome to in situ experimental warming across three elevations (3850 m, 4100 m, and 4250 m) in the meadow of Gongga Mountain, eastern Tibetan Plateau. Our findings demonstrate that soil microbial diversity is highly resilient to warming, with significant impacts observed only at specific elevations. Furthermore, the influence of warming on the composition of the soil microbial community is also elevation-dependent, underscoring the importance of local environmental context in shaping microbial evolution in alpine soils under climate warming. Notably, we identified soil moisture at 3850 m and carbon-to-nitrogen ratio at 4250 m as indirect predictors regulating the responses of microbial diversity to warming at specific elevations. These findings underscore the paramount importance of considering pre-existing environmental conditions in predicting the response of alpine soil microbiomes to climate warming. Our study provides novel insights into the intricate interactions between climate warming, soil microbiome, and environmental context in alpine ecosystems, illuminating the complex mechanisms governing soil microbial ecology in these fragile and sensitive environments.


Assuntos
Microbiota , Microbiologia do Solo , Tibet , Solo/química , Aquecimento Global , Ecossistema , Altitude , Mudança Climática
17.
J Agric Food Chem ; 72(22): 12489-12497, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38773677

RESUMO

The glutathione S-transferases (GSTs) are important detoxifying enzymes in insects. Our previous studies found that the susceptibility of Chilo suppressalis to abamectin was significantly increased when the CsGST activity was inhibited by glutathione (GSH) depletory. In this study, the potential detoxification mechanisms of CsGSTs to abamectin were explored. Six CsGSTs of C. suppressalis were expressed in vitro. Enzymatic kinetic parameters including Km and Vmax of recombinant CsGSTs were determined, and results showed that all of the six CsGSTs were catalytically active and displaying glutathione transferase activity. Insecticide inhibitions revealed that a low concentration of abamectin could effectively inhibit the activities of CsGSTs including CsGSTd1, CsGSTe4, CsGSTo2, CsGSTs3, and CsGSTu1. However, the in vitro metabolism assay found that the six CsGSTs could not metabolize abamectin directly. Additionally, the glutathione transferase activity of CsGSTs in C. suppressalis was significantly increased post-treatment with abamectin. Comprehensive analysis of the results in present and our previous studies demonstrated that CsGSTs play an important role in detoxification of abamectin by catalyzing the conjugation of GSH to abamectin in C. suppressalis, and the high binding affinities of CsGSTd1, CsGSTe4, CsGSTo2, CsGSTs3, and CsGSTu1 with abamectin might also suggest the involvement of CsGSTs in detoxification of abamectin via the noncatalytic passive binding and sequestration instead of direct metabolism. These studies are helpful to better understand the detoxification mechanisms of GSTs in insects.


Assuntos
Glutationa Transferase , Proteínas de Insetos , Inseticidas , Ivermectina , Mariposas , Glutationa Transferase/metabolismo , Glutationa Transferase/genética , Glutationa Transferase/química , Animais , Inseticidas/metabolismo , Inseticidas/farmacologia , Inseticidas/química , Mariposas/metabolismo , Mariposas/efeitos dos fármacos , Mariposas/enzimologia , Ivermectina/análogos & derivados , Ivermectina/metabolismo , Ivermectina/farmacologia , Ivermectina/química , Proteínas de Insetos/metabolismo , Proteínas de Insetos/genética , Proteínas de Insetos/química , Cinética , Oryza/metabolismo , Oryza/parasitologia , Oryza/química , Glutationa/metabolismo , Glutationa/química
20.
Micromachines (Basel) ; 15(5)2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38793187

RESUMO

Thin-walled bearings are widely used owing to the advantages of their light structure, high hardness, and strong load-carrying capacity. However, thin-walled bearings are often prone to deformation during the machining process, which can seriously affect the performance of the bearings. In addition, the machining deformation and quality of bearings are difficult to balance. To address the above issues, this paper investigates the effects of the machining parameters on the machining deformation, surface quality, and machining efficiency of a thin-walled bearing during the roughing stage. The dynamic balance between deformation inhibition and high quality in rough grinding was studied, and the optimal parameters for thin-walled bearing outer ring grinding were obtained. The deformation mechanism of thin-walled bearings caused by grinding was revealed through simulation and experimental analysis. The results show that the machining deformation and quality reach a balance when the workpiece speed is 55 r/min, the grinding wheel rotational speed is 2000 r/min, and the feed rate is 0.1 mm/min. Deformation increases with the increase in workpiece speed and grinding wheel speed. At the same time, the surface roughness increases with the increase in the workpiece speed, but the increase in the wheel speed will improve the surface roughness. As the workpiece speed increases, the surface topography shows a more pronounced stockpile of material, which is ameliorated by an increase in grinding wheel speed. As the rotational speed of the workpiece increases, the number of abrasive grains involved in the process per unit of time decreases, and the surface removal of the workpiece is less effective, while the increase in the rotational speed of the grinding wheel has the opposite effect. The grinding deformation of thin-walled bearings is mainly induced by machining heat and stress. As the rotational speed increases, the heat flux in the grinding zone increases. More heat flux flows into the surface of the workpiece, causing an increase in thermal stresses on the inner surface of the bearing collar, leading to greater deformation. The temperature in the grinding area can be reduced during machining, realizing a reduction in deformation. The research content contributes to the balance between high quality and low distortion in machining processes.

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