Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.119
Filtrar
1.
Nat Prod Res ; : 1-18, 2020 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-33034219

RESUMO

Rhizome Chuanxiong (RCX), the dried rhizomes of Ligusticum striatum DC., is a geoauthentic TCM herb distributed in Sichuan province of China that possesses efficacy in promoting blood circulation, removing blood stasis and alleviating pain. Rhizome Chuanxiong total alkaloids (RCXTAs) are one of the major characteristic constituents of RCX with the effects of antimigraine, neuroprotective, cardioprotective and other cardiovascular and cerebrovascular diseases. Over the past years, rapid development of technology has advanced some aspects of RCXTAs. The aim of this review is to illustrate the recent advances in the chemical analysis and biological activities of RCXTAs, and to highlight new challenges.

2.
Am J Clin Nutr ; 2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-33022701

RESUMO

BACKGROUND: Hyperinsulinemia and higher insulin-like growth factors may increase breast cancer risk. We evaluated a diabetes risk reduction diet (DRRD) and breast cancer risk. OBJECTIVES: We prospectively evaluated the association between adherence to a DRRD and the incidence of breast cancer. METHODS: We followed 88,739 women from the Nurses' Health Study (NHS; 1980-2016) and 93,915 women from the NHSII (1991-2017). Incident breast cancer cases (n = 11,943) were confirmed with medical records, and subtypes were determined by tissue microarray data and pathology reports. Information on diet and breast cancer risk factors was repeatedly ascertained in follow-up questionnaires. A DRRD score was derived with 9 factors: lower glycemic index of diet; lower intakes of trans fat, sugar-sweetened beverages/fruit juices, and red/processed meat; higher intakes of cereal fiber, coffee, nuts, and whole fruits; and a higher ratio of polyunsaturated to saturated fat (score range: 9-45). Multivariable-adjusted hazard ratios (MVHRs) and 95% CIs were calculated with Cox proportional hazards models. RESULTS: Being in the highest compared with the lowest DRRD adherence quintile was associated with a modestly lower breast cancer risk (MVHRQ5vsQ1: 0.89; 95% CI: 0.84, 0.95; P-trend = 0.0002); this was attenuated after adjusting for weight change since age 18 y (MVHRQ5vsQ1: 0.92; 95% CI: 0.87, 0.98; P-trend = 0.01). The inverse association was strongest among women with current BMI < 25 kg/m2 (MVHRQ5vsQ1: 0.89; 95% CI: 0.81, 0.98; P-trend = 0.004; P-interaction = 0.04). Among tumor molecular subtypes, the strongest inverse association was observed with basal-type tumors (MVHRQ5vsQ1: 0.67; 95% CI: 0.45, 1.01; P-trend = 0.04). CONCLUSIONS: Greater DRRD-adherence was associated with lower breast cancer risk, likely mediated by less weight gain with a DRRD; however, independently of weight change, DRRD-adherence was modestly associated with lower breast cancer risk, particularly among lean women.

3.
Artigo em Inglês | MEDLINE | ID: mdl-33026170

RESUMO

The dinickel(II) dihydride complex ( 1 K ) of a pyrazolate-based compartmental ligand with b-diketiminato (nacnac) chelate arms (L - ), which provides two pincer-type {N 3 } binding pockets, has been reported to readily eliminate H 2 and to serve as a masked dinickel(I) species. Discrete dinickel(I) complexes ( 2 Na , 2 K ) of L - have now been synthesized via a direct reduction route and fully characterized. They feature two adjacent T-shaped metalloradicals that are antiferromagnetically coupled ( J = -83/-71 cm -1 ), giving an S = 0 ground state. The two singly occupied local d x2-y2  type magnetic orbitals are oriented into the bimetallic cleft, enabling metal-metal cooperative 2e - substrate reductions as evidenced by the rapid reaction with H 2 or O 2 . X-ray crystallography reveals distinctly different positions of the K + in 1 K and 2 K , suggesting a stabilizing interaction of K + with the dihydride unit in 1 K . H 2 release from 1 K can be triggered by peripheral g-C protonation at the nacnac subunits, which according to DFT calculations drastically lowers the barrier for reductive H 2 elimination from the bimetallic cleft. The resulting twice protonated dinickel(I) complex 3 reflects the non-innocence of nacnac ligands in terms of metal-ligand cooperativity, as it harbors not only 2e - on the two metals but also 2H + stored at the ligand periphery.

4.
Chem Commun (Camb) ; 56(78): 11681-11684, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33000795

RESUMO

Two soft salts (S1 and S2) based on platinum(ii) complexes with a near-infrared emission have been designed and synthesized. It has been demonstrated that S2 has a high photostability and a low cytotoxicity, and it has been successfully applied to in vivo imaging for the first time.

5.
Anal Bioanal Chem ; 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33001243

RESUMO

A simple but efficient colorimetric assay was developed for the detection and quantification of acid phosphatase (ACP) using a smartphone. This strategy is based on target-controlled iodine-mediated etching of gold nanorods (AuNRs). Due to effective hydrolysis of the substrate pyrophosphate (PPi) by ACP, chelated Cu2+ with PPi was released, which promoted the redox reaction with an iodide ion (I-), leading to the formation of I3-. As the etching agent of AuNRs, I3- caused a blueshift of the localized surface plasmon resonance peak and, more importantly, an observable color change. The vivid colors were recorded with a smartphone camera and directly analyzed using an image-processing app. On the basis of the direct correlation between ACP concentration and the etching degree of AuNRs as well as color change, this smartphone nanocolorimetry technique showed a good linear response toward ACP over the range of 0-15.0 U/L, with a detection limit of 0.97 U/L. Using the standard addition method, the practical applicability of the proposed smartphone-based assay was successfully demonstrated by determining ACP in human serum samples, with results consistent with those obtained by UV-Vis spectrophotometry.

6.
Artigo em Inglês | MEDLINE | ID: mdl-33000173

RESUMO

CONTEXT: PD-1, CTLA-4, TIM-3, LAG-3 and TIGIT are considered as major immune co-inhibitory receptors (CIRs) and most promising immunotherapeutic targets in cancer treatment, but they are largely unexplored in medullary thyroid carcinoma (MTC). OBJECTIVE: We aimed to provide first evidence regarding the expression profiles and clinical significance of CIRs in a large cohort of MTCs. DESIGN AND PATIENTS: In total, 200 MTCs who received initial surgery in our hospital were included. Immunohistochemistry was performed to evaluate CIR expressions in tissue microarrays (TMA). Combined with the results of our previous PD-L1 study, clinicopathologic and prognostic correlations of these proteins were retrospectively analyzed. RESULTS: TIM-3, PD-1, CTLA-4, LAG-3 and TIGIT positivity was detected in 96 (48.0%), 27 (13.5%), 25 (12.5%), 6 (3.0%) and 6 (3.0%) patients, respectively, in which TIM-3, PD-1 and CTLA-4 expressions were positively correlated. Both log-rank tests and multivariate Cox analyses indicated that TIM-3, CTLA-4 expression and PD-1/PD-L1 coexpression were associated with worse structural recurrence-free survival. In addition, among 20 patients who developed advanced disease during follow-up, 12 (60%) showed TIM-3 positivity, wherein 6 cases also had concurrent moderate to strong PD-1, PD-L1 or CTLA-4 expression. CONCLUSIONS: Using the currently largest TMA cohort of this rare cancer, we delineated the CIR expression profiles in MTC, and identified TIM-3, CTLA-4 expression and PD-1/PD-L1 coexpression as promising biomarkers for tumor recurrence. Furthermore, a subset of advanced MTCs are probably immunogenic, for whom single or combined immunotherapy including TIM-3, PD-1, PD-L1 or CTLA-4 blockade may be potential therapeutic approaches in the future.

7.
Theranostics ; 10(24): 11278-11301, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33042283

RESUMO

Intra- and interindividual variation in drug responses is one major reason for the failure of drug therapy, drug toxicity, and even the death of patients. Precision medicine, or personalized medicine, is a field of medicine that customizes an individual's medical diagnosis and treatment based on his/her genes, microbiomes, environments, etc. Over the past decade, a large number of studies have demonstrated that gut microbiota can modify the efficacy and toxicity of drugs, and the extent of the modification varies greatly from person to person because of the variability of the gut microbiota. Personalized manipulation of gut microbiota is an important approach to rectify the abnormal drug response. In this review, we aim to improve drug efficacy and reduce drug toxicity by combining precision medicine and gut microbiota. After describing the interactions between gut microbiota and xenobiotics, we discuss (1) the effects of gut microbiota on drug efficacy and toxicity and the corresponding mechanisms, (2) the variability of gut microbiota, which leads to variation in drug responses, (3) the biomarkers used for the patient stratification and treatment decisions before the use of drugs, and (4) the methods used for the personalized manipulation of gut microbiota to improve drug outcomes. Overall, we hope to improve the drug response by incorporating the knowledge of gut microbiota into clinical practice.

8.
Signal Transduct Target Ther ; 5(1): 213, 2020 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-32968059

RESUMO

Protein-protein interactions (PPIs) have pivotal roles in life processes. The studies showed that aberrant PPIs are associated with various diseases, including cancer, infectious diseases, and neurodegenerative diseases. Therefore, targeting PPIs is a direction in treating diseases and an essential strategy for the development of new drugs. In the past few decades, the modulation of PPIs has been recognized as one of the most challenging drug discovery tasks. In recent years, some PPIs modulators have entered clinical studies, some of which been approved for marketing, indicating that the modulators targeting PPIs have broad prospects. Here, we summarize the recent advances in PPIs modulators, including small molecules, peptides, and antibodies, hoping to provide some guidance to the design of novel drugs targeting PPIs in the future.

9.
J Agric Food Chem ; 68(39): 10586-10595, 2020 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-32866004

RESUMO

Selenium nanoparticles (SeNPs) have been applied in fields of nanobiosensors, environment, nanomedicine, etc. as a result of their excellent characteristics. Early studies had shown that SeNPs have certain inhibition ability against glycation, but the inhibition mechanism, especially for the influence of SeNPs on the reaction activity of glycation sites, remains unclear. The aim of the presented research was to reveal the effects of SeNPs on the ß-lactoglobulin (ß-Lg)/d-ribose glycation system at the molecular level and explore the possible inhibitory mechanism of SeNPs on the formation of advanced glycation end products (AGEs) by analyzing the glycation sites via high-performance liquid chromatography (HPLC)-Orbitrap-tandem mass spectrometry (MS/MS). Changes in contents of AGE formation and free amino acid contents had indicated that SeNPs could significantly slow the glycation process, thus attenuating the formation of AGEs. HPLC-Orbitrap-MS/MS analysis revealed that, at 6, 12, and 24 h, the number of glycation sites of glycated ß-Lg decreased from 7, 7, and 9 to 5, 5, and 6 after the intervention of SeNPs, respectively. The glycation extent of each glycation site was controlled, and the dual-glycation ability of K8, K14, K47, K91, and K101 was changed. All of these results confirmed that SeNPs could indeed slow the process of protein glycation at the molecular level. This may be the reason for SeNPs reducing the formation of AGEs during glycation. Therefore, this study shed light on the insight of how SeNPs reduce the formation of AGEs.

10.
BMJ Open ; 10(9): e038551, 2020 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-32928861

RESUMO

OBJECTIVE: We aimed to describe the association between in-hospital infection and prognosis among patients with non-ST elevation acute coronary syndrome (NSTE-ACS) who received percutaneous coronary intervention (PCI). DESIGN: This observational cohort originated from a database of patients with NSTE-ACS who underwent PCI from 1 January 2010 to 31 December 2014. SETTING: Five centres in South China. PARTICIPANTS: This multicentre observational cohort study consecutively included 8197 patients with NSTE-ACS who received PCI. Only patients with adequate information to diagnose or rule out infection were included. Patients were excluded if they were diagnosed with a malignant tumour, were pregnant or presented with cardiogenic shock at the index date. Patients were grouped by whether they had in-hospital infection or not. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was all-cause death and major bleeding during hospitalisation. The secondary outcomes included all-cause death and major bleeding during follow-up and in-hospital myocardial infarction. RESULTS: Of the 5215 patients, 206 (3.95%) acquired infection. Patients with infection had a higher rate of in-hospital all-cause death and major bleeding (4.4% vs 0.2% and 16.5% vs 1.2%, respectively; p<0.001). After adjusting for confounders, infection remained independently associated with in-hospital and long-term all-cause death (OR, 13.19, 95% CI 4.59 to 37.87; HR, 2.03, 95% CI 1.52 to 2.71; p<0.001) and major bleeding (OR, 10.24, 95% CI 6.17 to 16.98; HR, 5.31, 95% CI 3.49 to 8.08; p<0.001). A subgroup analysis confirmed these results. CONCLUSIONS: The incidence of infection is low during hospitalisation, but is associated with worse in-hospital and long-term outcomes.

11.
Emerg Microbes Infect ; 9(1): 2013-2019, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32867625

RESUMO

COVID-19 is a new respiratory illness caused by SARS-CoV-2, and has constituted a global public health emergency. Cat is susceptible to SARS-CoV-2. However, the prevalence of SARS-CoV-2 in cats remains largely unknown. Here, we investigated the infection of SARS-CoV-2 in cats during COVID-19 outbreak in Wuhan by serological detection methods. A cohort of serum samples were collected from cats in Wuhan, including 102 sampled after COVID-19 outbreak, and 39 prior to the outbreak. Fifteen sera collected after the outbreak were positive for the receptor binding domain (RBD) of SARS-CoV-2 by indirect enzyme linked immunosorbent assay (ELISA). Among them, 11 had SARS-CoV-2 neutralizing antibodies with a titer ranging from 1/20 to 1/1080. No serological cross-reactivity was detected between SARS-CoV-2 and type I or II feline infectious peritonitis virus (FIPV). In addition, we continuously monitored serum antibody dynamics of two positive cats every 10 days over 130 days. Their serum antibodies reached the peak at 10 days after first sampling, and declined to the limit of detection within 110 days. Our data demonstrated that SARS-CoV-2 has infected cats in Wuhan during the outbreak and described serum antibody dynamics in cats, providing an important reference for clinical treatment and prevention of COVID-19.


Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Betacoronavirus/imunologia , Infecções por Coronavirus/veterinária , Pandemias/veterinária , Pneumonia Viral/veterinária , Animais , Gatos , China , Infecções por Coronavirus/epidemiologia , Coronavirus Felino/imunologia , Reações Cruzadas/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Imunoglobulina G/sangue , Proteínas do Nucleocapsídeo/imunologia , Pneumonia Viral/epidemiologia , Glicoproteína da Espícula de Coronavírus/imunologia
12.
Virol Sin ; 2020 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-32960400

RESUMO

Severe fever with thrombocytopenia syndrome virus (SFTSV), the causative agent of a febrile human disease, was first identified from central and eastern provinces in China, and later in Japan and South Korea. Hubei Province is one of the major SFTS epidemic areas in the central part of China. This study reported the isolation of 11 new SFTSV strains from patients in Hubei Province collected in 2017. Extensive phylogenetic analyses were conducted based on the complete coding sequences of SFTSV segments including the new strains. It was suggested that five different SFTSV genotypes were circulating in Hubei, and 15 reassortment patterns and migration pathways correlated with each genotype were identified, which was more than previously recognized. Hubei Province was more involved in the evolutionary events of SFTSV than that previously thought in which the evolutionary events of SFTSV were reported to be independent from those in other epidemic regions. Further divergence of SFTSV strains was suggested by pairwise comparison of SFTSV sequences from each genotype and sequence identity normalized to representative strain in genotype C1. Subsequently, amino acid variations specific for genotype(s), strain(s), or cluster(s) were inspected, which may be related to differential biological activity of SFTSV strains/genotypes. In conclusion, we analyzed the current status of SFTSV phylogeny in Hubei Province and discussed the possible events correlated to SFTSV evolution. It provided an in-depth insight into SFTSV evolution, raising concerns for the use of proper SFTSV strains in future studies.

13.
World J Gastroenterol ; 26(31): 4607-4623, 2020 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-32884220

RESUMO

BACKGROUND: Early diagnosis of hepatocellular carcinoma may help to ensure that patients have a chance for long-term survival; however, currently available biomarkers lack sensitivity and specificity. AIM: To characterize the serum metabolome of hepatocellular carcinoma in order to develop a new metabolomics diagnostic model and identifying novel biomarkers for screening hepatocellular carcinoma based on the pattern recognition method. METHODS: Ultra-performance liquid chromatography-mass spectroscopy was used to characterize the serum metabolome of hepatocellular carcinoma (n = 30) and cirrhosis (n = 29) patients, followed by sequential feature selection combined with linear discriminant analysis to process the multivariate data. RESULTS: The concentrations of most metabolites, including proline, were lower in patients with hepatocellular carcinoma, whereas the hydroxypurine levels were higher in these patients. As ordinary analysis models failed to discriminate hepatocellular carcinoma from cirrhosis, pattern recognition analysis was used to establish a pattern recognition model that included hydroxypurine and proline. The leave-one-out cross-validation accuracy and area under the receiver operating characteristic curve analysis were 95.00% and 0.90 [95% Confidence Interval (CI): 0.81-0.99] for the training set, respectively, and 78.95% and 0.84 (95%CI: 0.67-1.00) for the validation set, respectively. In contrast, for α-fetoprotein, the accuracy and area under the receiver operating characteristic curve were 65.00% and 0.69 (95%CI: 0.52-0.86) for the training set, respectively, and 68.42% and 0.68 (95%CI: 0.41-0.94) for the validation set, respectively. The Z test revealed that the area under the curve of the linear discriminant analysis model was significantly higher than the area under the curve of α-fetoprotein (P < 0.05) in both the training and validation sets. CONCLUSION: Hydroxypurine and proline might be novel biomarkers for hepatocellular carcinoma, and this disease could be diagnosed by the metabolomics model based on pattern recognition.

14.
J Mol Model ; 26(10): 270, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32930882

RESUMO

Halogen bonding (XB) has been applied in many fields from crystal engineering to medicinal chemistry. Compared with the well-studied XB of simple halogenated aromatics, little research has been done on the XB of halogenated fused-ring heteroaromatics, a prevalent substructure in organic compounds. With 1H-pyrrolo[3,2-b]pyridines (PPs) as examples of novel fused-ring heteroaromatics with hydrogen bond donor and acceptor and XB donor, the XB formed by the halogenated heteroaromatics was explored in this study. With 4 different substituents, viz., -CH3, -NH2, -F, and -CONH2, at different positions, 339 derivatives of brominated PP (Br-PP) were designed for calculating their electrostatic potential of the σ-hole of the halogen atom (VS,max) and binding energy with ammonia as XB acceptor (Eint) at M06-2X/6-311++G(d,p) level by PCM model in dichloromethane. The calculated VS,max values ranging from -1.3 to 35.1 kcal/mol and the calculated Eint ranging from -0.82 to -2.37 kcal/mol demonstrated that the XB is complicated and highly tunable. Noticeably, the electron-withdrawing substituents, especially at ortho-position, do not always increase the values of VS,max, while the electron-donating substituents do not always decrease VS,max. Similar results were observed from the calculation on 339 iodinated PPs at M06-2X/6-311++G(d,p) level. The complexity of the XB formed by the halogenated fused ring heteroaromatics indicated a great potential of tuning its strength by different substituents at different positions and revealed a necessity of quantum chemistry calculation for predicting the XB.Graphical abstract.

15.
Mol Biol Evol ; 2020 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-32941615

RESUMO

How animals, particularly livestock, adapt to various climates and environments over short evolutionary time is of fundamental biological interest. Further, understanding the genetic mechanisms of adaptation in indigenous livestock populations is important for designing appropriate breeding programs to cope with the impacts of changing climate. Here we conducted a comprehensive genomic analysis of diversity, interspecies introgression and climate-mediated selective signatures in a global sample of sheep and their wild relatives. By examining 600k and 50k genome-wide SNP data from 3447 samples representing 111 domestic sheep populations and 403 samples from all their seven wild relatives (argali, Asiatic mouflon, European mouflon, urial, snow sheep, bighorn and thinhorn sheep), coupled with 88 whole-genome sequences, we detected clear signals of common introgression from wild relatives into sympatric domestic populations, thereby increasing their genomic diversities. The introgressions provided beneficial genetic variants in native populations, which were significantly associated with local climatic adaptation. We observed common introgression signals of alleles in olfactory-related genes (e.g., ADCY3 and TRPV1) and the PADI gene family including in particular PADI2, which is associated with antibacterial innate immunity. Further analyses of whole-genome sequences showed that the introgressed alleles in a specific region of PADI2 (chr2: 248302667-248306614) correlate with resistance to pneumonia. We conclude that wild introgression enhanced climatic adaptation and resistance to pneumonia in sheep. This has enabled them to adapt to varying climatic and environmental conditions after domestication.

16.
Acta Pharmacol Sin ; 2020 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-32939034

RESUMO

Acute liver failure (ALF) is a fatal clinical syndrome with no special drug. Recent evidence shows that modulation of macrophage to inhibit inflammation may be a promising strategy for ALF treatment. In this study we investigated the potential therapeutic effects of melittin, a major peptide component of bee venom both in mice model of ALF and in LPS-stimulated macrophages in vitro, and elucidated the underlying mechanisms. ALF was induced in mice by intraperitoneal injection of D-galactosamine/LPS. Then the mice were treated with melittin (2, 4, and 8 mg/kg, ip). We showed that melittin treatment markedly improved mortality, attenuated severe symptoms and signs, and alleviated hepatic inflammation in D-galactosamine/LPS-induced ALF mice with the optimal dose being 4 mg/kg. In addition, melittin within the effective doses did not cause significant in vivo toxicity. In LPS-stimulated RAW264.7 macrophages, melittin (0.7 µM) exerted anti-oxidation and anti-inflammation effects. We showed that LPS stimulation promoted aerobic glycolysis of macrophages through increasing glycolytic rate, upregulated the levels of Warburg effect-related enzymes and metabolites including lactate, LDHA, LDH, and GLUT-1, and activated Akt/mTOR/PKM2/HIF-1α signaling. Melittin treatment suppressed M2 isoform of pyruvate kinase (PKM2), thus disrupted the Warburg effect to alleviate inflammation. Molecular docking analysis confirmed that melittin targeted PKM2. In LPS-stimulated RAW264.7 macrophages, knockdown of PKM2 caused similar anti-inflammation effects as melittin did. In D-galactosamine/LPS-induced ALF mice, melittin treatment markedly decreased the expression levels of PKM2 and HIF-1α in liver. This work demonstrates that melittin inhibits macrophage activation-mediated inflammation via inhibition of aerobic glycolysis by targeting PKM2, which highlights a novel strategy of using melittin for ALF treatment.

17.
Sci Rep ; 10(1): 14363, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32873868

RESUMO

Limited to the Atlantic and its surrounding basins, the expression of the Coniacian-Santonian oceanic anoxic event (OAE3) was discovered in the non-marine Cretaceous Songliao Basin, Eastern Asia not long ago. In this study, based on spectral gamma ray logs data recorded in three basins, the self-similarity of the OAE3 was studied through the analysis of the scaling properties of thorium-potassium and thorium-uranium distributions both in marine and terrestrial environments using the multifractal detrending fluctuation analysis. The results indicate that, in both marine and terrestrial systems, the OAE3 intervals are characterized by their multifractal nature due to long-range correlation. However, the multifractal features of the studied OAE3 intervals are different in the three basins, although some common trends were observed. By comparing the degree of multifractality of the OAE3 deposits with the clay minerals and the redox conditions, it appears that the changes of the multifractal features are controlled by local changes such as clay mineralogy and redox conditions in both milieus under different sedimentation patterns. At all sites, the left side shortened spectrum of the thorium-potassium distribution suggests the presence of local fluctuations with minor amplitudes during the OAE3. Furthermore, the shortened singularity spectrum of the thorium-uranium distribution reflects the existence of small-scale fluctuations with large amplitudes at marine sites while in the non-marine Songliao Basin, the thorium-uranium distribution suggests the presence of local fluctuations with small amplitudes during the OAE3. Therefore, a more local behavior of the event is considered although the regional character is not neglected.

19.
Org Biomol Chem ; 18(36): 7086-7089, 2020 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-32910128

RESUMO

An iron-catalyzed radical cascade cyclization of dienes initiated by an alkoxycarbonyl radical has been developed in the presence of (NH4)2S2O8, leading to a series of fused nitrogen heterocyclic compounds under relatively mild reaction conditions. The reaction is triggered by the addition of an alkyoxycarbonyl radical derived from the cleavage of alkoxyformyl hydrazide. Afterward, the formed nucleophilic radical preferred addition to the electron-neutral vinyl rather than the electron-deficient vinyl, followed by cascade 6-endo cyclization and further radical cyclization.

20.
Biomed Pharmacother ; 131: 110724, 2020 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-32920518

RESUMO

Stachydrine is a main active component of Leonurus japonicus (Chinese motherwort), which has traditionally been used to promote postpartum recovery and alleviate myocardial and cerebral ischemic injuries due to its pro-angiogenic effect. Our prior study demonstrated that stachydrine increased angiogenesis in zebrafish embryos, but its pro-angiogenic effect and underlying mechanisms on human umbilical vein endothelial cells (HUVECs) remain largely unknown. In the present study, we further investigated the role of stachydrine in sunitinib-injured HUVECs and its potential molecular mechanisms. The results showed that stachydrine exhibited a protective effect on sunitinib-injured HUVECs and significantly promoted their proliferation, migration, and tube formation, all central events of angiogenesis. In addition, stachydrine inhibited apoptosis and ROS production in sunitinib-injured HUVECs. Furthermore, our findings illustrated for the first time that stachydrine's molecular mechanisms for promoting angiogenesis might correlate with activation of the VEGFR2/MEK/ERK and inhibition of the mitochondrial-mediated apoptosis signaling pathway.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA