Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 9.441
Filtrar
1.
Front Cell Infect Microbiol ; 11: 693981, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34504806

RESUMO

Objective: Macrophages function as key orchestrators in the pathogenesis of acute lung injury (ALI). The current study sets out to investigate the molecular mechanism of transforming growth factor-ß (TGFß1) in the regulation of M1 alveolar macrophage polarization in ALI by modulating DNA methyltransferase 1 (DNMT1), along with the microRNA (miR)-124/Pellino 1 (PELI1)/interferon regulatory factor 5 (IRF5) axis. Methods: First, ALI mouse models were established, and the proportion of M1 and M2 macrophages in mouse lung tissues was detected using flow cytometry. The targeting relationship between miR-124 and PELI1 was verified with the help of a dual luciferase gene reporter assay. Following TGFß1 knockdown, RT-qPCR and Western blot assay were performed to analyze the expression patterns of TGFß1, DNMT1, miR-124, and PELI1 and M1/M2 polarization markers in the lung tissues of ALI mice. Immunofluorescence was further employed to detect nuclear translocation of IRF5 in macrophages. Results: The polarization of M1 macrophages was found to be positively correlated with the severity of lung injury. TGFß1, DNMT1, PELI1 were highly expressed, while miR-124 was down-regulated in ALI mice, and IRF5 was primarily distributed in the nucleus. TGFß1 promoted the polarization of M1 alveolar macrophages by up-regulating DNMT1. Furthermore, DNMT1 down-regulated the expression of miR-124, which led to enhancement of M1 alveolar macrophage polarization. Meanwhile, over-expression of miR-124 inhibited the nuclear translocation of IRF5 and suppressed M1 alveolar macrophage polarization. On the other hand, over-expression of PELI1 reversed the above trends. Conclusion: Collectively, our findings indicated that TGFß1 can promote the expression of DNMT1, which down-regulates miR-124 to activate PELI1 and nuclear translocation of IRF5, thereby aggravating ALI in mice.

2.
Exp Eye Res ; 211: 108750, 2021 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-34481822

RESUMO

Pseudomonas aeruginosa (P. aeruginosa) keratitis, a worldwide leading cause of corneal perforation and blindness, which is associated with contact lens usage. Increasing evidence has indicated that pyroptosis, a novel proinflammatory programmed cell death, is linked with ocular diseases, little is known about the role of noncanonical pyroptosis in microbial keratitis. Here, we first indicated the involvement of noncanonical pyroptosis in P. aeruginosa keratitis and investigated whether wedelolactone (WDL), a major active component of Eclipta prostrate known to target caspase-11, could alleviate P. aeruginosa keratitis development. We found the expression of caspase-4/5/11 and cleaved GSDMD in corneas of P. aeruginosa keratitis patients, animal models and lipopolysaccharide (LPS)-induced primary cultured human corneal keratocytes (piHCKs) were increased. Combining ciprofloxacin with WDL significantly ameliorated the severity of P. aeruginosa keratitis, as manifested by decreased inflammatory responses and reduced corneal epithelial defects. Consistent with these findings, WDL also dose-dependently alleviated LPS-induced noncanonical pyroptosis by reversing the increased expression of caspase-4/5 and GSDMD in piHCKs. In summary, our results demonstrated that by targeting the activation of caspase-4/5/11, wedelolactone inhibited the development of P. aeruginosa keratitis and suppressed the release of proinflammatory cytokines. Wedelolactone may be a promising anti-inflammatory candidate to combat P. aeruginosa keratitis.

3.
Oral Dis ; 2021 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-34514700

RESUMO

OBJECTIVES: The objective of this study was to explore the role and mechanism of an abnormally expressed circRNA (hsa_circ_0009128) in the progression of oral squamous cell carcinoma. MATERIALS AND METHODS: We conducted quantitative real-time PCR (qRT-PCR) to assess the expression of hsa_circ_0009128 in 51 paired OSCC tissues and analyzed the correlation between clinical features and aberrant expression of hsa_circ_0009128 in OSCC. CCK8 assays, colony formation assays, transwell assays, and wound healing assays were used to analyze the effect of hsa_circ_0009128 on cell proliferation and migration. Furthermore, epithelial-mesenchymal transition (EMT)-related proteins were evaluated by Western Blotting. RESULTS: Hsa_circ_0009128 was upregulated in both OSCC tissues and cell lines, and high hsa_circ_0009128 correlated with advanced TNM stage (P=0.046) and lymph node metastasis (P=0.018) in OSCC patients. Knockdown of hsa_circ_0009128 inhibited cell proliferation and migration. Mechanistically, hsa_circ_0009128 downregulation decreased EMT in OSCC cells as shown by increased levels of E-cadherin and decreased N-cadherin, Vimentin, and MMP9. CONCLUSIONS: The circRNA hsa_circ_0009128 correlates with malignant progression of OSCC. Hsa_circ_0009128 stimulates proliferation and migration in OSCC cells by targeting MMP9 to activate EMT.

4.
Mol Cell Proteomics ; : 100148, 2021 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-34530157

RESUMO

Lysine acylations are reversible and ubiquitous post-translational modifications that play critical roles in regulating multiple cellular processes. In the current study, highly abundant and dynamic acetylation, besides succinylation, was uncovered in a soil bacterium, Streptomyces coelicolor. By affinity enrichment using anti-acetyllysine antibody and the following LC-MS/MS analysis, a total of 1,298 acetylation sites among 601 proteins were identified. Bioinformatics analyses suggested that these acetylated proteins have diverse subcellular localization and were enriched in a wide range of biological functions. Specifically, a majority of the acetylated proteins were also succinylated in the TCA cycle and protein translation pathways, and the bi-modification occurred at the same sites in some proteins. The acetylation and succinylation sites were quantified by knocking out either the deacetylase ScCobB1 or the desuccinylase ScCobB2, demonstrating a possible competitive relationship between the two acylations. Moreover, in-vitro experiments using synthetically modified peptides confirmed the regulatory crosstalk between the two sirtuins, which may be involved in the collaborative regulation of cell physiology. Collectively, these results provided global insights into the S. coelicolor acylomes and laid a foundation for characterizing the regulatory roles of the crosstalk between lysine acetylation and succinylation in the future.

5.
Brain Imaging Behav ; 2021 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-34535879

RESUMO

The aim of this study was to investigate the abnormities in functional connectivity (FC) within each modular network and between modular networks in patients with systemic lupus erythematosus (SLE). Twelve meaningful modular networks were identified via independent component analysis from 41 patients and 40 volunteers. Parametric tests were used to compare the intra- and intermodular FC between the groups. Partial correlation analysis was used to seek the relationships between abnormal FCs and the clinical data. Compared to the controls, SLE patients showed decreased intramodular FC in the anterior default mode network (aDMN), posterior default mode network (pDMN), ventral attention network (VAN), and sensorimotor network (SMN) and increased intramodular FC in the medial visual network (mVN) and left frontoparietal network. In addition, SLE patients showed decreased intermodular FC between the SMN and the lateral visual network (lVN), between the SMN and the VAN, and between the pDMN and the lVN and exhibited increased intermodular FC between the SMN and the salience network (SAN), between the pDMN and the SAN, and between the aDMN and the VAN. Moreover, we found several correlations among the abnormal FCs and the Mini-Mental State Examination in SLE patients. Mild cognitive impairment is compensated by the hyperconnectivity between the aDMN and the VAN, while severe cognitive impairment tends to be compensated by the hyperconnectivity between the SMN and the SAN. The FC value between the SMN and the SAN and between the aDMN and the VAN may serve as neuroimaging markers for monitoring cognitive progression in SLE patients.

6.
J Plant Physiol ; 266: 153510, 2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34521019

RESUMO

Source sink balance is one of the major determinants of carbon partitioning in plants. However, its effects on photosynthesis in fruit trees are largely unknown. In this work, the effects of low sink demand on net photosynthetic rate (Pn) and chlorophyll fluorescence after fruit removal (-fruit) in peach (Prunus persica (L.) Batsch cv. 'Zaojiubao') trees were investigated. The stepwise energy flow through photosystem II (PSII) at the reaction center (RC) was analyzed with quantitative analyses of fluorescence transient, also called JIP-test. We found that Pn was significantly lower and closely correlated to the leaf stomatal conductance (Gs) of -fruit trees than that of fruit retained (+fruit) trees. Leaf temperature (Tleaf) of -fruit trees was remarkably higher than that of +fruit trees. Day-time-period assays of chlorophyll (Chl) fluorescence revealed that, in the leaves of -fruit trees, the fluorescence parameters, such as NPQ (non-photochemical quenching coefficient) and ΦD0 (maximum quantum yield of non-photochemical de-excitation), decreased in the morning and recovered to the normal level in the afternoon, whereas other parameters, such as ΦE0 (quantum yield for electron transport at t = 0), Ψ0 (probability that a trapped exciton moves an electron to QA pool), F0 (minimum fluorescence, when all PSII RCs are open) and Wk (relative variable fluorescence at 300 µs of the chlorophyll fluorescence transient), did not. These results suggest that OEC complex and QA pool were irreversibly affected by low sink demand, whereas light harvest antenna and PSII potential efficiency retained a strong ability to recover.

7.
Stat Methods Med Res ; : 9622802211037076, 2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34520293

RESUMO

Non-proportional hazards data are routinely encountered in randomized clinical trials. In such cases, classic Cox proportional hazards model can suffer from severe power loss, with difficulty in interpretation of the estimated hazard ratio since the treatment effect varies over time. We propose CauchyCP, an omnibus test of change-point Cox regression models, to overcome both challenges while detecting signals of non-proportional hazards patterns. Extensive simulation studies demonstrate that, compared to existing treatment comparison tests under non-proportional hazards, the proposed CauchyCP test (a) controls the type I error better at small α levels (<0.01); (b) increases the power of detecting time-varying effects; and (c) is more computationally efficient than popular methods like MaxCombo for large-scale data analysis. The superior performance of CauchyCP is further illustrated using retrospective analyses of two randomized clinical trial datasets and a pharmacogenetic biomarker study dataset. The R package CauchyCP is publicly available on CRAN.

8.
Nat Commun ; 12(1): 5444, 2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34521850

RESUMO

Kawasaki disease (KD) is the most common cause of acquired heart disease in children in developed countries. Although functional and phenotypic changes of immune cells have been reported, a global understanding of immune responses underlying acute KD is unclear. Here, using single-cell RNA sequencing, we profile peripheral blood mononuclear cells from seven patients with acute KD before and after intravenous immunoglobulin therapy and from three age-matched healthy controls. The most differentially expressed genes are identified in monocytes, with high expression of pro-inflammatory mediators, immunoglobulin receptors and low expression of MHC class II genes in acute KD. Single-cell RNA sequencing and flow cytometry analyses, of cells from an additional 16 KD patients, show that although the percentage of total B cells is substantially decreased after therapy, the percentage of plasma cells among the B cells is significantly increased. The percentage of CD8+ T cells is decreased in acute KD, notably effector memory CD8+ T cells compared with healthy controls. Oligoclonal expansions of both B cell receptors and T cell receptors are observed after therapy. We identify biological processes potentially underlying the changes of each cell type. The single-cell landscape of both innate and adaptive immune responses provides insights into pathogenesis and therapy of KD.

9.
Cell Biol Int ; 2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34519129

RESUMO

Pancreatic carcinoma (PC) is one of the most common and deadly human malignancies worldwide. LncRNAs play significant roles in the occurrence and development of various cancers. LncRNA SNHG11 (SNHG11) has been found to display high expression in serum of PC patients, which implies that dysregulated SNHG11 may be related to development of PC. However, there is still a knowledge gap concerning the specific function and molecular mechanism of SNHG11 in PC. After conducting experiments with constructed models in vitro or in vivo, we found that exosomal SNHG11 promoted cell proliferation, migration and angiogenesis but impeded cell apoptosis in PC in vitro, and additionally, it facilitated tumor growth in vivo. Exosome-mediated SNHG11 regulated expression of VEGFA through sponging miR-324-3p. Rescue assays validated that the inhibitory effect of SNHG11 depletion on cell proliferation, migration and angiogenesis could be reversed by miR-324-3p down-regulation or VEGFA up-regulation, and the promoting effect of SNHG11 silence on cell apoptosis could be rescued by transfection of miR-324-3p inhibitor or pcDNA3.1-VEGFA. To conclude, exosomal-mediated SNHG11 could regulate PC progression via miR-324-3p/VEGFA axis. Our findings may provide a novel insight for understanding PC, which might contribute to development of potential PC biomarker. This article is protected by copyright. All rights reserved.

10.
J Am Chem Soc ; 2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34519488

RESUMO

We report a new form of catalyst based on ferromagnetic hexagonal-close-packed (hcp) Co nanosheets (NSs) for selective CO2RR to ethanal, CH3CHO. In all reduction potentials tested from -0.2 to -1.0 V (vs RHE) in 0.5 M KHCO3 solution, the reduction yields ethanal as a major product and ethanol/methanol as minor products. At -0.4 V, the Faradaic efficiency (FE) for ethanal reaches 60% with current densities of 5.1 mA cm-2 and mass activity of 3.4 A g-1 (total FE for ethanal/ethanol/methanol is 82%). Density functional theory (DFT) calculations suggest that this high CO2RR selectivity to ethanal on the hcp Co surface is attributed to the unique intralayer electron transfer, which not only promotes [OC-CO]* coupling but also suppresses the complete hydrogenation of the coupling intermediates to ethylene, leading to highly selective formation of CH3CHO.

11.
Cancer Biol Med ; 2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34491007

RESUMO

OBJECTIVE: Large volume radiological text data have been accumulated since the incorporation of electronic health record (EHR) systems in clinical practice. We aimed to determine whether deep natural language processing algorithms could aid radiologists in improving thyroid cancer diagnosis. METHODS: Sonographic EHR data were obtained from the EHR database. Pathological reports were used as the gold standard for diagnosing thyroid cancer. We developed thyroid cancer diagnosis based on natural language processing (THCaDxNLP) to interpret unstructured sonographic text reports for thyroid cancer diagnosis. We used the area under the receiver operating characteristic curve (AUROC) as the primary metric to measure the performance of the THCaDxNLP. We compared the performance of thyroid ultrasound radiologists aided with THCaDxNLP vs. those without THCaDxNLP using 5 independent test sets. RESULTS: We obtained a total number of 788,129 sonographic radiological reports. The number of thyroid sonographic data points was 132,277, 18,400 of which were thyroid cancer patients. Among the 5 test sets, the numbers of patients per set were 439, 186, 82, 343, and 171. THCaDxNLP achieved high performance in identifying thyroid cancer patients (the AUROC ranged from 0.857-0.932). Thyroid ultrasound radiologists aided with THCaDxNLP achieved significantly higher performances than those without THCaDxNLP in terms of accuracy (93.8% vs. 87.2%; one-sided t-test, adjusted P = 0.003), precision (92.5% vs. 86.0%; P = 0.018), and F1 metric (94.2% vs. 86.4%; P = 0.007). CONCLUSIONS: THCaDxNLP achieved a high AUROC for the identification of thyroid cancer, and improved the accuracy, sensitivity, and precision of thyroid ultrasound radiologists. This warrants further investigation of THCaDxNLP in prospective clinical trials.

12.
Acta Pharmacol Sin ; 2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34480113

RESUMO

Spinal cord injury (SCI) is one kind of severe trauma for central nervous system. Myelin debris clearance and axon regeneration are essential for nerve regeneration after SCI. Metformin, a glucose-lowering drug, has been demonstrated to promote the locomotor functional recovery after SCI. In this study, we investigated the role and molecular mechanism of metformin on myelin preservation in a rat SCI model. SCI was induced in rats by compression at T9 level using a vascular clip. We showed that administration of metformin (50 mg·kg-1·d-1, ip) for 28 days significantly improved locomotor function in SCI rats. Metformin also ameliorated SCI-induced neuronal apoptosis and promoted axon regeneration in the spinal cord. Using co-immunofluorescence of IBa-1 and MBP, and luxol fasting blue (LFB) staining, we demonstrated that metformin promoted the transformation of M1 to M2 phenotype polarization of microglial cells, then greatly facilitated myelin debris clearance and protected the myelin in SCI rats. Furthermore, metformin ameliorated SCI-induced blockade of autophagic flux in the spinal cord, and enhanced the fusion of autophagosome and lysosome by inhibiting the AMPK-mTOR signaling pathway. Moreover, metformin significantly attenuated inflammatory responses in the spinal cord. In LPS-treated BV2 cells, pretreatment with metformin (2 mM) significantly enhanced autophagy level, suppressed inflammation and cell apoptosis. The protective effects were blocked in the presence of an autophagy inhibitor 3-methyladenine (3-MA, 5 mM), suggesting that the effect of metformin on autophagy in microglial cells is essential for the myelin preservation during nerve recovery. This study reveals a novel therapeutic effect of metformin in SCI recovery by regulating the activation of microglial cells and enhancing its autophagy level.

13.
JCI Insight ; 2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34491915

RESUMO

Obesity, a major healthcare issue, is characterized by metabolic abnormalities in multiple tissues, including the skeletal muscle. Although dysregulation of skeletal muscle metabolism can strongly influence the homeostasis of systemic energy, the underlying mechanism remains unclear. We found promoter hypermethylation and decreased gene expression of fibroblast growth factor 6 (FGF6) in the skeletal muscle of individuals with obesity using high-throughput sequencing. Reduced binding of the cyclic AMP responsive element binding protein-1 (CREB1) to the hypermethylated cyclic AMP (cAMP) response element, which is a regulatory element upstream of the transcription initiation site, partially contributed to the downregulation of FGF6 in patients with obesity. Overexpression of Fgf6 in mice skeletal muscle stimulated protein synthesis, activating the mammalian target of rapamycin (mTOR) pathway, and prevented the increase in weight and the development of insulin resistance in high-fat diet-fed mice. Thus, our findings highlight the role played by Fgf6 in regulating skeletal muscle hypertrophy and whole-body metabolism, indicating its potential in strategies aimed at preventing and treating metabolic diseases.

14.
Zhongguo Zhen Jiu ; 41(9): 1023-8, 2021 Sep 12.
Artigo em Chinês | MEDLINE | ID: mdl-34491653

RESUMO

OBJECTIVE: To observe the effect of electroacupuncture (EA) on expression of interleukin (IL) -23/IL-17 axis and Toll-like receptor 4 (TLR4) in the infarcted tissue in rats with myocardial infarction (MI), and to explore the mechanism of EA on alleviating MI injury. METHODS: Forty male SD rats were randomly divided into a sham-operation group, a sham-operation plus EA group, a model group and an EA group, 10 rats in each group. The MI models were established by ligation of left anterior descending coronary artery in the model group and EA group, while only threading was performed in the sham-operation group and sham-operation plus EA group. The rats in the sham-operation plus EA group and EA group were treated with EA at "Neiguan" (PC 6), disperse-dense wave, 2 Hz/100 Hz, 2 mA, once a day, 20 min each time, for 3 days. After the intervention, the ejection fraction (EF) was measured by echocardiography to evaluate the cardiac function; the infarct area was measured by TTC staining; the HE staining was used to observe the morphological changes of myocardial tissue; the levels of IL-23 and IL-17 in infarcted tissue were detected by ELISA; the protein expression of TLR4 in infarcted tissue was detected by Western blot. RESULTS: Compared with the sham-operation group, the EF was decreased (P<0.01), the infarct area was increased (P<0.01), the myocardial fiber injury was obvious, accompanied by inflammatory cell infiltration, and the contents of IL-23, IL-17 and the expression of TLR4 in infarcted tissue were increased in the model group (P<0.01). Compared with the model group, the EF was increased (P<0.05), the infarct area was reduced (P<0.05), the myocardial fiber injury was significantly improved, the inflammatory cell infiltration was reduced, and the contents of IL-23, IL-17 and TLR4 expression in infarcted tissue were decreased in the EA group (P<0.05). CONCLUSION: EA may alleviate the excessive inflammatory response after MI by inhibiting the expression of IL-23/IL-17 axis in MI rats, and TLR4 may be involved during the process.


Assuntos
Eletroacupuntura , Infarto do Miocárdio , Animais , Interleucina-17/genética , Interleucina-23/genética , Masculino , Infarto do Miocárdio/genética , Infarto do Miocárdio/terapia , Ratos , Ratos Sprague-Dawley , Receptor 4 Toll-Like/genética
15.
Nucleic Acids Res ; 2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-34500470

RESUMO

Aminoacyl-tRNA synthetases (aaRSs) are essential enzymes that provide the ribosome with aminoacyl-tRNA substrates for protein synthesis. Mutations in aaRSs lead to various neurological disorders in humans. Many aaRSs utilize editing to prevent error propagation during translation. Editing defects in alanyl-tRNA synthetase (AlaRS) cause neurodegeneration and cardioproteinopathy in mice and are associated with microcephaly in human patients. The cellular impact of AlaRS editing deficiency in eukaryotes remains unclear. Here we use yeast as a model organism to systematically investigate the physiological role of AlaRS editing. Our RNA sequencing and quantitative proteomics results reveal that AlaRS editing defects surprisingly activate the general amino acid control pathway and attenuate the heatshock response. We have confirmed these results with reporter and growth assays. In addition, AlaRS editing defects downregulate carbon metabolism and attenuate protein synthesis. Supplying yeast cells with extra carbon source partially rescues the heat sensitivity caused by AlaRS editing deficiency. These findings are in stark contrast with the cellular effects caused by editing deficiency in other aaRSs. Our study therefore highlights the idiosyncratic role of AlaRS editing compared with other aaRSs and provides a model for the physiological impact caused by the lack of AlaRS editing.

16.
Ann Palliat Med ; 2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34498479

RESUMO

BACKGROUND: Impairment of motor function and activities of daily living is very common in post-stroke patients. Acupuncture has been used in stroke for a long time. Although growing evidence supports the beneficial effects of acupuncture, there is still no clear conclusion on the optimal intervention time-point for acupuncture in stroke. Thus, we tried to assess the efficacy and safety of dissimilar acupuncture intervention time-points by network meta-analysis (NMA). METHODS: A retrieval was performed in several databases from beginning to October 2020. We only enrolled randomized controlled trials (RCTs) testing acupuncture for stroke, and the outcome indicators measured were Fugl-Meyer assessment (FMA) score, Barthel Index (BI), and adverse events. RESULTS: Thirty-eight trials involving 3,836 participants were included in this NMA, the vast majority of which had a low or unclear risk of selection bias, detection bias, reporting bias, attrition bias, but had a high risk of performance bias. The results showed as following: (I) acupuncture treatment (Acu) is significantly more effective than non-acupuncture treatment (Non-Acu) with a good safety. (II) In terms of FMA, acupuncture within 48 h post-stroke (Acu I) was superior to acupuncture within 2-15 d post-stroke (Acu II) [standard mean difference (SMD): 7.17; 95% confidence interval (CI), 1.11 to 13.22], acupuncture within 16-30 d post-stroke (Acu III) (SMD: 20.73; 95% CI, 13.68 to 27.78), acupuncture within 1 month to half a year post-stroke (Acu IV) (SMD: 26.95; 95% CI, 14.88 to 39.02). As for BI, Acu I was the optimal timepoint, comparing with Acu III (SMD: 15.18; 95% CI, 8.97 to 21.39) and Acu IV (SMD: 22.88; 95% CI, 11.07 to 34.69). (III) Results of ranking indicated that Acu was better than Non-Acu at a similar stage in improving FMA and BI, while Acu I was the optimal intervention time-point, followed by Acu II. CONCLUSIONS: Although the credibility of our conclusions is low, our NMA indicates that acupuncture can be beneficial for stroke survivors with good safety. In terms of improvement in FMA score and BI, the soon use of acupuncture the better the efficacy. The optimal acupuncture intervention time-point for stroke is within 48 h post-stroke, and the significant validity period lasts until 15 days after onset.

17.
Nat Prod Res ; : 1-9, 2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-34498960

RESUMO

A new icetexane diterpenoid, 11, 12, 20α-trihydroxyl-7ß-methoxyicetexa-8, 11, 13-triene-19, 10-lactone [Phyllane A (1)], and a new abietane diterpenoid, 7ß, 20-epoxy-3ß, 17-acetoxy-abieta-8, 11, 13-teriene-11, 12-diol [phyllane B (2)], along with two known compounds (3 and 4) were isolated from the methanol (MeOH) extract of twigs and leaves of the folk medicinal Isodon phyllopodus. Their structures were determined by spectroscopic analyses including 2 D NMR spectral data, and further confirmed by X-ray single crystal diffraction. Moreover, the compounds were evaluated for their cytotoxicity and anti-HIV activities, and phyllane A showed anti-HIV activity with an IC50 value of 15.7 µM, but phyllane B was found to be cytotoxic to the A549 host cells with a CC50 value of 108.5 µM.

18.
Artigo em Inglês | MEDLINE | ID: mdl-34472178

RESUMO

The Diels-Alder reactions of tropolone and its conjugate base with N-methylmaleimide have been explored computationally and experimentally. Previous studies of the [4+2] cycloaddition under basic conditions show that both endo- and exo-products are obtained in similar, but variable amounts. Density functional theory ( w B97X-D) explorations of potential energy surfaces, and molecular dynamics trajectories show that the reaction involves an ambimodal transition state for the reaction of the ammonium tropolonate with N-methylmaleimide, and that similar amounts of endo- and exo-products are obtained. The thermal reaction, studied experimentally in detail here for the first time, is predicted to form the endo-adduct through an ambimodal transition state. The exo-adduct can be formed from the same transition state, but requires a hydrogen shift, that hinders this reaction dynamically. Longer reaction times give a small excess of the exo-product, which is thermodynamically more stable.

19.
PLoS One ; 16(9): e0257236, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34529689

RESUMO

The present study was performed to evaluate the effects of seed priming. This was done by soaking the seeds of two rapeseed cultivars, namely, ZY15 (tolerant to low temperature and drought) and HY49 (sensitive to low temperature and drought), for 12 h in varying solutions: distilled water, 138 mg/L salicylic acid (SA), 300 mg/L gibberellic acid (GA), 89.4 mg/L sodium nitroprusside (SNP), 3000 mg/L calcium chloride (CaCl2), and 30 mg/L abscisic acid (ABA). Primed and non-primed seeds were left to germinate at 15°C and -0.15 MPa (T15W15) and at 25°C and 0 MPa (T25W0), respectively. The results showed that SA, GA, SNP, CaCl2, and ABA significantly improved the germination potential (GP), germination rate (GR), germination index (GI), stem fresh weight (SFW), stem dry weight (SDW), root length (RL), stem length (SL), and seed vigor index (SVI) under T15W15. For ZY15 seeds under T25W0, GA, SNP, CaCl2, and ABA priming reduced the average germination time (96% after 5 days) compared to that of the control (88% after 5 days). For ZY15 seeds under T15W15, SA, SNP, CaCl2, and ABA priming, with respect to the control and water-treated groups, shortened the average germination time (92% after 5 days) compared to that of the control (80% after 5 days). For HY49 seeds under T25W0, GA, SNP, CaCl2, and ABA priming reduced the average germination time (92% after 5 days) compared to that of the control (85% after 5 days). Similarly, for HY49 seeds under T15W15, GA priming shortened the average germination time (89% after 5 days) compared to that of the control (83% after 5 days). These priming agents increased the net photosynthesis, stomatal conductivity, and transpiration rate of rape seedlings under conditions of low temperature and drought stress, while also decreasing intercellular carbon dioxide (CO2) concentrations. Additionally, SA, GA, SNP, CaCl2, and ABA increased superoxide dismutase concentrations (SOD) and ascorbic peroxidase (APX) activities of rape seedlings under stress conditions, while decreasing catalase (CAT) and peroxidase (POD) activities in ZY15 seedlings. In HY49, which is sensitive to low temperature and drought, all priming solutions, except for SNP, led to an increase in SOD activity levels and a decrease in CAT activity levels. Overall, SA, GA, SNP, and CaCl2 increased the concentrations of indoleacetic acid (IAA), GA, ABA, and cytokinin (CTK) in seedlings under stress conditions. Moreover, compared to SA, CaCl2, and ABA, GA (300 mg/L) and SNP (300 mol/L) showed improved priming effects for ZY15 and HY49 under stress conditions.

20.
PLoS One ; 16(9): e0257362, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34534257

RESUMO

By combining the discrete element method (DEM) with computational fluid dynamics (CFD), this study proposes a three-dimensional CFD-DEM fluid-solid coupling microscopic computational model for analyzing the micromechanisms of instability and failure in a coal-bearing soil slope during rainfall. The CFD-DEM fluid-solid coupling model indicated that the main failure mode of the coal-bearing soil slopes was rainwater washing, and the slope sliding surface was predicted as an approximately linear segment. The adaptability of this numerical method was verified by comparing its results with those of rain-washed slopes in an outdoor model test. Rainfall changed the microscopic parameters such as the force chain, coordination number, and porosity of the slope soil particles. The porosity of the slope's top particles increased from 0.35 in the initial state to 0.80 in the unstable state. This change was directly related to the macroscopic mechanics of the slope soil. By analyzing the changes in the microscopic parameters of the particles, the failure evolution law of the coal-bearing soil slopes during rainfall was explored from a microscopic perspective. This study not only provides a theoretical basis for the protection design and construction of coal-bearing soil slopes in the region but can also analyze macroscopic mechanical laws of discrete media from a micro-macro perspective in geotechnical engineering.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...