Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 124
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Plant Dis ; 2024 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-38616400

RESUMO

Amorphophallus muelleri is an Araceae plant with perennial tuber, widely used in food, pharmaceutical and chemical industry due to its richness in glucomannan. In April 2022, an outbreak of a target spot on A. muelleri plantlets was observed in a nursery in Ruili, Yunnan, China. The leafstalks of the diseased plantlets in the nursery turned brown and decayed (Fig.1 A-B), then gradually some water-soaked spots on the true leaves developed along the veins (Fig.1 A). Subquencely, the spots on the true leaves turned dark green to white-grayish in the center, which formed light to dark brown concentric rings with a target-like appearance surrounded by a yellow halo (Fig.1 C). When the temperature was 20-34℃ and the relatively humidity was 25-80%, dark-green to black sporodochia with white hypha appeared on the lower and upper leaf surfaces. Finally, 5-8% of the plants surveyed on 800 m2 of one-year-old plantlets in the nursery showed the symptoms and some plants with infected leafstalks would be death. Similar symptoms were also observed on about 10% of the transplanted plants surveyed on 12000 m2 (1.2 ha) of two-year-old plantlets in the field. Five diseased leaves from five distinct plantlets in the nursery were collected for pathogen isolation. Leaf pieces(5 x 5 mm) were cut from the edge of necrotic lesions, and surface-sterilized with 2.5% sodium hypochlorite for 1 min, 75% ethanol for 30 s, then rinsed 5 times by sterilized distilled water, finally put the leaf pieces on sterilized filter paper for 3-5 minutes to dry them and transferred onto potato dextrose agar (PDA) in petri dishes at 25℃ for three days. Five pure cultures identical to colony and conidial characteristics were isolated from five individual plants. The representative pure culture (M1) was grayish-white and circular colonies were 7.50 cm in diamter after 15 days at 25℃, with dark green concentric rings of sporodochia, the dorsal view of the colonies were yellowish. Conidia were aseptate, smooth, cylindrical, 5.00-6.25 (5.71) x 1.25-1.67 (1.63) µm (n = 20) rounded at both ends. A spore suspension (1 x 106 spores/ml) was prepared by harvesting spores from 15-day-old cultures grown in the dark at 25℃, then a thirty-ml of spore suspension was sprayed on the healthy leaves of 10 two-year-old plantlets. Thirty-ml of sterile water was sprayed on the healthy leaves of another 10 seedlings and used as the control. All seedlings were placed in a nursery at 20 to 34℃ and a relative humidity of 25 to 80%. Similar symptoms (Fig.1 D-F) to those observed in the nursery and field developed on all the 10 seedlings inoculated with M1 after two days, but not on the control leaves. The pathogenicity tests were repeated for three times. Fungal cultures reisolated from the infected leaves were identical to the original colonies and conidia, completing Koch's postulates. The internal transcribed spacer (ITS, primers ITS1 and ITS4) region of ribosomal DNA (OQ553785), calmodulin (cmdA, primers CAL-228F and CAL2Rd)(OQ559103), RNA polymerase II second largest subunit (rpb2, primers RPB2-5F2 and RPB2-7cR) (OQ559104) and ß-tubulin (tub2, primers Bt2a and Bt2b) (OQ559105) of M1 had 100%, 98.52%, 98.98% and 98.98% identity with the sequences of Paramyrothecium breviseta CBS544.75 (KU846289 for ITS, KU846262 for cmdA, KU846351 for rpb2, and KU846406 for tub2), respectively. In the phylogenic tree based on ITS, cmdA, rpb2 and tub2 gene sequences, the pure culture M1 clustered with P. breviseta CBS544.75, SDBR-CMU387, DRL4 and DRL3, which has been reported as the pathogen of leaf spot of Coffea arabica in China, C. canephora in China and Thailand (Wu et al. 2021; Withee et al. 2022). Molecular and morphological observations showed the pure culture M1 were P. breviseta (Withee et al. 2022), in addition the disease was named as target spot dueing to the typical target symptom on the leaves. To our knowledge, this is the first report of P. breviseta on A. muelleri from Yunnan, China, as well as worldwide. This disease can caused serious economic losses of A. muelleri dueing to that it can result 5-8% death of the plants in the nursery.

2.
Acta Odontol Scand ; 80(2): 117-124, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34280323

RESUMO

OBJECTIVE: Circular RNAs (circRNAs) involve in the development and progression of tumour. The mechanism of circRNAs in oral squamous cell carcinoma (OSCC) has remained unclear. This study aimed to investigate the role of circular Yes-associated protein (circYap) in OSCC. METHODS: Quantification reverse transcription-polymerase chain reaction (qRT-PCR) was applied to measure circYap expression in patients with OSCC tissues and cells. Flow cytometry was performed to evaluate cell cycle. circYap interaction with CDK4 was detected by RNA immunoprecipitation (RIP) and RNA pull-down. The interaction of Cyclin D1 and CDK4 was determined using co-immunoprecipitation (co-IP). RESULTS: We showed that circYap expression was downregulated in OSCC tissues. Using small interfering circular (Si-circYap) and overexpression plasmid, we found that circYap overexpression inhibited proliferation and arrested cell cycle in OSCC cells, while, circYap knockdown yielded the opposite result. Cyclin D1/CDK4 complexes and nuclear translocation is essential for cell cycle progression. We found that CDK4 interacted with circYap was increased when circYap overexpression, meanwhile, Cyclin D1/CDK4 complexes and of nuclear distribution were decreased. CONCLUSIONS: Our findings suggest that circYap impedes progression of OSCC. Overexpression of circYap suppresses proliferation and cell cycle through binding to CDK4 to block formation and nuclear translocation of Cyclin D1/CDK4 complexes. Thus, circYap may serves as a valuable therapeutic target for OSCC.


Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Neoplasias Bucais , Carcinoma de Células Escamosas/genética , Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Neoplasias Bucais/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço
3.
Saudi Pharm J ; 29(12): 1405-1415, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35002378

RESUMO

Icariin is commonly used for the clinical treatment of osteonecrosis of the femoral head (ONFH). miR-23a-3p plays a vital role in regulating the osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs). The present study aimed to investigate the roles of icariin and miR-23a-3p in the osteogenic differentiation of BMSCs and an ONFH model. BMSCs were isolated and cultured in vitro using icariin-containing serum at various concentrations, and BMSCs were also transfected with a miR-23a inhibitor. The alkaline phosphatase (ALP) activity and cell viability as well as BMP-2/Smad5/Runx2 and WNT/ß-catenin pathway-related mRNA and protein expression were measured in BMSCs. Additionally, a dual-luciferase reporter assay and pathway inhibitors were used to verify the relationship of icariin treatment/miR-23a and the above pathways. An ONFH rat model was established in vivo, and a 28-day gavage treatment and lentivirus transfection of miR-23a-3p inhibitor were performed. Then, bone biochemical markers (ELISA kits) in serum, femoral head (HE staining and Digital Radiography, DR) and the above pathway-related proteins were detected. Our results revealed that icariin treatment/miR-23a knockdown promoted BMSC viability and osteogenic differentiation as well as increased the mRNA and protein expression of BMP-2, BMP-4, Runx2, p-Smad5, Wnt1 and ß-catenin in BMSCs and ONFH model rats. In addition, icariin treatment/miR-23a knockdown increased bone biochemical markers (ACP-5, BAP, NTXI, CTXI and OC) and improved ONFH in ONFH model rats. In addition, a dual-luciferase reporter assay verified that Runx2 was a direct target of miR-23a-3p. These data indicated that icariin promotes BMSC viability and osteogenic differentiation as well as improves ONFH by decreasing miR-23a-3p levels and regulating the BMP-2/Smad5/Runx2 and WNT/ß-catenin pathways.

4.
Appl Opt ; 59(24): 7338-7342, 2020 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-32902500

RESUMO

We study the motion morphology, distance, and velocity of plasma and laser-induced shock waves induced by a millisecond-nanosecond (ms-ns) combined-pulse laser with different pulse delays on silicon. The laser shadowgraph method is used, and the phenomenon of double laser-induced shock waves has been found while the pulse delay is 1.2-1.8 ms. The controlling variable method is used to study this phenomenon, and it is found that it is mainly related to the ignition of the laser-supported absorption wave induced by the ms laser. Moreover, the plasma expansion velocity increases with the increase of pulse delay, the axial propagation distance of laser-induced shock waves increases monotonically with pulse delay, and the velocity of laser-induced shock waves decreases with the increase of pulse delay.

5.
Zhongguo Zhong Yao Za Zhi ; 45(1): 98-105, 2020 Jan.
Artigo em Zh | MEDLINE | ID: mdl-32237417

RESUMO

To improve the spray drying effect of extract of Wenjing Zhitong Prescription, this study takes the yield, hygroscopic property and the fluidity of dry powder as indexes to screen out auxiliary materials, and the proportion of the auxiliary materials was optimized based on the mixing design experiment; based on that, HPLC method was established for the determination of glycyrrhizin and 6-gingerol in spray powder, the yield of spray powder and the retention rate of the two index components were taken as indexes to further optimize the spray drying parameters. The finally selected auxiliary materials were light magnesium oxide, maltodextrin and silica, and regression equations of dry powder yield, moisture absorption rate, angle of rest with proportion of auxiliary materials were established, and the optimized proportion of auxiliary materials was dry paste-light magnesium oxide-maltodextrin-silica=0.5∶0.305∶0.145∶0.05; according to the optimized drying process parameters of Wenjing Zhitong Prescription, initial temperature was 60 ℃, air inlet temperature was 130 ℃, air flow rate was 35 m~3·h~(-1), atomizing pressure was 40 mm, and liquid inlet speed was 4.5 mL·min~(-1). Under these conditions, the dry powder yield was 90.28%, the retention rate of glycyrrhizin was 74.51%, and the retention rate of 6-gingerol was 72.10%. In this study, optimized auxiliary materials can improve the yield of spray drying and the property of spray powder, and the optimized processing conditions were good for retaining the unstable gingerol components, which can lay a foundation for the further preparation research of meridian warming and pain relieving prescriptions, and provide reference for extract of other traditional Chinese medicine extracts that are difficult to spray drying.


Assuntos
Química Farmacêutica/métodos , Dessecação/métodos , Medicamentos de Ervas Chinesas/química , Temperatura Alta , Medicina Tradicional Chinesa , Pós
6.
J Cell Biochem ; 120(1): 562-574, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30191596

RESUMO

As a potent and selective drug, brigatinib exhibits high efficacy against wild-type and mutant anaplastic lymphoma kinase (ALK) proteins to treat non-small cell lung cancer. In this work, the mechanisms of brigatinib binding to wild type and four mutant ALKs were investigated to gain insight into the dynamic energetic and structural information with respect to the design of novel inhibitors. Comparison between ALK-brigatinib and ALK-crizotinib suggests that the scaffold of brigatinib is well anchored to the residue Met1199 of hinge region by two hydrogen bonds, and the residue Lys1150 has the strong electrostatic interaction with the dimethylphosphine oxide moiety in brigatinib. These ALK mutations have significant influences on the flexibility of P-loop region and DFG sequences, but do not impair the hydrogen bonds between brigatinib and the residue Met1199 of hinge region. And mutations (L1196M, G1269A, F1174L, and R1275Q) induce diverse conformational changes of brigatinib and the obvious energy variation of residues Glu1167, Arg1209, Asp1270, and Asp1203. Together, the detailed explanation of mechanisms of those mutations with brigatinib further provide several guidelines for the development of more effective ALK inhibitors.


Assuntos
Quinase do Linfoma Anaplásico/química , Antineoplásicos/química , Crizotinibe/química , Resistencia a Medicamentos Antineoplásicos , Compostos Organofosforados/química , Inibidores de Proteínas Quinases/química , Pirimidinas/química , Quinase do Linfoma Anaplásico/genética , Antineoplásicos/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Crizotinibe/uso terapêutico , Bases de Dados de Proteínas , Descoberta de Drogas/métodos , Humanos , Ligação de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Neoplasias Pulmonares/tratamento farmacológico , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Mutação , Compostos Organofosforados/uso terapêutico , Ligação Proteica , Inibidores de Proteínas Quinases/uso terapêutico , Estrutura Secundária de Proteína , Pirimidinas/uso terapêutico , Eletricidade Estática
7.
Arch Toxicol ; 93(11): 3207-3218, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31552475

RESUMO

Prediction of pEC50 values of dioxins binding with the aryl hydrocarbon receptor (AhR) is of great significance for exploring how dioxins induce toxicity in human body and evaluating their environmental behaviors and risks. To reveal the factors that influence the toxicity of dioxins, provide more accurate mathematical models for predicting the pEC50 values of dioxins, and supplement the toxicity database of persistent organic pollutants, qualitative structure-activity relationship (SAR) and two-dimensional quantitative structure-activity relationship (2D-QSAR) were used in this study. The research objects in this study were 60 organic compounds with pEC50 values and 162 compounds without pEC50 values, which included polychlorinated dibenzofurans (PCDFs), polychlorinated dibenzo-p-dioxins (PCDDs), and polybrominated dibenzo-p-dioxins (PBDDs). The qualitative structure-activity relationship (SAR) was performed first and concluded that halogen substitutions at any of the 2, 3, 7, and 8 sites increased the pEC50 value of the compound. Moreover, two-dimensional quantitative structure-activity relationship (2D-QSAR) models were established by employing multiple linear regression (MLR) method and artificial neural network (ANN) algorithm to investigate the factors affecting the pEC50 values of dioxins molecules. MLR was used to establish the well-understood linear model and ANN was used to establish a more accurate non-linear model. Both models have good fitting, robustness, and predictive ability. Importantly, the ability of dioxins binding to AhR is mainly determined by molecular descriptors including E1m, SM09_AEA (dm), RDF065u, F05 [Cl-Cl], and Neoplastic-80. In addition, the pEC50 values of the 162 dioxins without toxicity data were predicted by MLR and ANN models, respectively.


Assuntos
Dioxinas , Poluentes Ambientais , Modelos Teóricos , Relação Quantitativa Estrutura-Atividade , Algoritmos , Dioxinas/química , Dioxinas/toxicidade , Poluentes Ambientais/química , Poluentes Ambientais/toxicidade , Modelos Lineares , Redes Neurais de Computação , Ligação Proteica , Receptores de Hidrocarboneto Arílico/química
8.
Int J Mol Sci ; 20(24)2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31842360

RESUMO

Drought stress is a major obstacle to agriculture. Although many studies have reported on plant drought tolerance achieved via genetic modification, application of plant growth-promoting rhizobacteria (PGPR) to achieve tolerance has rarely been studied. In this study, the ability of three isolates, including Bacillus amyloliquefaciens 54, from 30 potential PGPR to induce drought tolerance in tomato plants was examined via greenhouse screening. The results indicated that B. amyloliquefaciens 54 significantly enhanced drought tolerance by increasing survival rate, relative water content and root vigor. Coordinated changes were also observed in cellular defense responses, including decreased concentration of malondialdehyde and elevated concentration of antioxidant enzyme activities. Moreover, expression levels of stress-responsive genes, such as lea, tdi65, and ltpg2, increased in B. amyloliquefaciens 54-treated plants. In addition, B. amyloliquefaciens 54 induced stomatal closure through an abscisic acid-regulated pathway. Furthermore, we constructed biofilm formation mutants and determined the role of biofilm formation in B. amyloliquefaciens 54-induced drought tolerance. The results showed that biofilm-forming ability was positively correlated with plant root colonization. Moreover, plants inoculated with hyper-robust biofilm (ΔabrB and ΔywcC) mutants were better able to resist drought stress, while defective biofilm (ΔepsA-O and ΔtasA) mutants were more vulnerable to drought stress. Taken altogether, these results suggest that biofilm formation is crucial to B. amyloliquefaciens 54 root colonization and drought tolerance in tomato plants.


Assuntos
Adaptação Biológica , Bacillus amyloliquefaciens/fisiologia , Biofilmes , Secas , Solanum lycopersicum/microbiologia , Solanum lycopersicum/fisiologia , Estresse Fisiológico , Antioxidantes/metabolismo , Desenvolvimento Vegetal , Raízes de Plantas/microbiologia , Raízes de Plantas/fisiologia , Simbiose
9.
Pharmacol Res ; 129: 491-499, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29175550

RESUMO

The smoothened (SMO) receptor, an essential signal transducer in the Hedgehog pathway, was targeted with antagonists to suppress the tumor. It is interesting that SMO D473H mutation confers resistance on inhibitor LDE-225 rather than LEQ-506. In this paper, the binding modes of them against the wild type and mutant SMO receptors were identified to gain insights into the resistant and non-resistant factors, based on a comprehensive protocol involving molecular docking, molecular dynamic simulations, free energy calculation and decomposition. A comparison of resistant LDE-225 and non-resistant LEQ-506 indicates that the volume of the binding cavity decreases seriously in the mutant complex with resistant LDE-225. In addition, the D473H mutation disrupts the hydrogen bond network with residues R400 and Q477, which results in the TM6 conformation inward. Owing to the absence of the hydrogen bond, residues R400 and Q477 make weak contributions to LDE-225. However, the D473H mutation along with TM6 conformational change has no effect on non-resistant LEQ-506. Finally, the resistance ascribes to adverse interaction between the greater polarity of mutant residue H473 and the nonpolar phenmethyl of LDE-225. The elaborate insights into structural and energetic mechanism of drug resistance provide an effective strategy to design rationally non-resistant antagonists.


Assuntos
Compostos de Bifenilo/farmacologia , Modelos Moleculares , Piridinas/farmacologia , Receptor Smoothened/antagonistas & inibidores , Resistência a Medicamentos , Humanos , Ligantes , Mutação , Receptor Smoothened/genética , Receptor Smoothened/metabolismo
10.
Org Biomol Chem ; 16(10): 1641-1645, 2018 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-29461552

RESUMO

An efficient and practical methodology to obtain α-thio-ß-dicarbonyl compounds was presented under alkaline conditions via potassium iodide (KI) catalysis; various symmetrical/unsymmetrical 1,3-dicarbonyl compounds were obtained under an aerobic atmosphere in moderate to excellent yields, with good functional group tolerance. Notably, a widely used anti-inflammatory drug butazodine could be modified with our protocol, even on a gram scale.

11.
Dig Dis Sci ; 63(12): 3348-3358, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30155836

RESUMO

BACKGROUND: Aberrant expression of retinoic acid receptor α (RARα) was correlated with diverse carcinomas such as acute promyelocytic leukemia and colorectal carcinoma. Nevertheless, the function and mechanism of RARα in esophageal carcinoma (EC) remain unclear. AIM: To investigate the expression of RARα in EC and its effect in the tumorigenesis of EC. METHODS AND RESULTS: In immunohistochemistry study, RARα was overexpressed in human EC tissues, and its overexpression was closely related to the pathological differentiation, lymph node metastasis, and clinical stages in EC patients. Functionally, RARα knockdown suppressed the proliferation and metastasis of EC cells through downregulating the expression of PCNA, Ki67, MMP7, and MMP9, as well as enhanced drug susceptibility of EC cells to 5-fluorouracil and cisplatin. Mechanistically, RARα knockdown inhibited the activity of Wnt/ß-catenin pathway through reducing the phosphorylation level of GSK3ß at Ser-9 and inducing phosphorylation level at Tyr-216, which resulted in downregulation of its downstream targets such as MMP7, MMP9, and P-gP. CONCLUSIONS: Our results demonstrated that RARα knockdown suppressed the tumorigenicity of EC via Wnt/ß-catenin pathway. RARα might be a potential molecular target for EC clinical therapy.


Assuntos
Neoplasias Esofágicas , Regulação Neoplásica da Expressão Gênica , Receptor alfa de Ácido Retinoico/metabolismo , Via de Sinalização Wnt/fisiologia , Carcinogênese/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/patologia , Feminino , Técnicas de Inativação de Genes/métodos , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Ensaio Tumoral de Célula-Tronco/métodos
12.
World J Surg ; 42(6): 1841-1847, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29138913

RESUMO

OBJECTIVE: Albumin-bilirubin (ALBI) grade has been validated as a simple, evidence-based, and objective prognostic tool for patients with hepatocellular carcinoma (HCC). However, minimal information is available concerning postoperative ALBI grade changes in HCC. This study aimed to investigate the prognostic value of postoperative ALBI grade changes in patients with hepatitis B virus (HBV)-related HCC within the Milan criteria after liver resection. METHODS: Patients with HBV-related HCC within the Milan criteria who underwent liver resection between 2010 and 2016 at West China Hospital were reviewed (N = 258). A change in ALBI grade was defined as first postoperative month ALBI grade-preoperative ALBI grade. If the value was >0, postoperative worsening of ALBI grade was considered; otherwise, stable ALBI grade was considered. Cox proportional hazard regression analyses were used to determine the factors that influence recurrence and survival. RESULTS: During the follow-up, 130 patients experienced recurrence and 47 patients died. Multivariate analyses revealed that postoperative worsening of ALBI grade (HR 1.541, 95% CI 1.025-2.318, P = 0.038), microvascular invasion (MVI, HR 1.802, 95% CI 1.205-2.695, P = 0.004), and multiple tumors (HR 1.676, 95% CI 1.075-2.615, P = 0.023) were associated with postoperative recurrence, whereas MVI (HR 2.737, 95% CI 1.475-5.080, P = 0.001), postoperative worsening of ALBI grade (HR 2.268, 95% CI 1.227-4.189, P = 0.009), high alpha-fetoprotein level (HR 2.055, 95% CI 1.136-3.716, P = 0.017), and transfusion (HR 2.597, 95% CI 1.395-4.834, P = 0.003) negatively influenced long-term survival. Patients with postoperative worsening of ALBI grade exhibited increased incidence of recurrence and worse long-term survival. CONCLUSION: Postoperative worsening of ALBI grade was associated with increased recurrence and poorer overall survival for patients with HBV-related HCC within the Milan criteria. We should pay attention to liver function changes in HCC patients after liver resection.


Assuntos
Bilirrubina/sangue , Carcinoma Hepatocelular/mortalidade , Hepatite B/complicações , Neoplasias Hepáticas/mortalidade , Albumina Sérica/análise , Adulto , Idoso , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/etiologia , Feminino , Humanos , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/etiologia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/etiologia , Prognóstico , Modelos de Riscos Proporcionais , Estudos Retrospectivos
13.
Molecules ; 23(10)2018 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-30332835

RESUMO

Gx-50 is a bioactive compound for the treatment of Alzheimer's disease (AD) found in Sichuan pepper (Zanthoxylum bungeanum). In order to find a stronger anti-AD lead compound, 20 gx-50 (1⁻20) analogs have been designed and synthesized, and their molecular structures were determined based on nuclear magnetic resonance (NMR) and mass spectrometry (MS) analysis, as well as comparison with literature data. Compounds 1⁻20 were evaluated for their anti-AD potential by using DPPH radical scavenging assay for considering their anti-oxidant activity, thioflavin T (ThT) fluorescence assay for considering the inhibitory or disaggregate potency of Aß, and transgenic Drosophila model assay for evaluating their rescue effect on memory loss. Finally, compound 13 was determined as a promising anti-AD candidate.


Assuntos
Peptídeos beta-Amiloides/química , Antioxidantes/síntese química , Cinamatos/síntese química , Transtornos da Memória/tratamento farmacológico , Zanthoxylum/química , Peptídeos beta-Amiloides/efeitos dos fármacos , Animais , Animais Geneticamente Modificados , Antioxidantes/química , Antioxidantes/farmacologia , Cinamatos/química , Cinamatos/farmacologia , Modelos Animais de Doenças , Drosophila , Humanos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Transtornos da Memória/genética , Estrutura Molecular
14.
Angew Chem Int Ed Engl ; 57(47): 15510-15516, 2018 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-30255542

RESUMO

A simple and efficient synthesis of NBN-doped conjugated polycyclic aromatic hydrocarbons (such as diazaborinines) has been accomplished by a catalyst-free intermolecular dehydration reaction at room temperature between boronic acid and diamine moieties with yields up to 99 %. Polycyclic aromatic hydrocarbons with a six-membered NBN ring are a new class of aggregation-induced emissive luminogens. Extremely sensitive detection of ppb levels of TNT by phenyl naphthodiazaborinine is straightforward. Visual detection of TNT is illustrated by fabrication of TNT test strips, which can detect as little as 100 ng of TNT powder. This simple and sensitive detection of TNT has potential applications in the area of public safety and security against terrorist activities.

15.
Proteins ; 84(8): 1108-23, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27119584

RESUMO

DYRK1A is characterized by the early development and regulation of neuronal proliferation, and its over expression gives rise to neurological abnormalities. As the promising DYRK1A inhibitors, the binding mechanism between DYRK1A and pyrido[2,3-d]pyrimidines derivatives at molecular level are still veiled. In this article, it was achieved to get the structural insights into pyrido[2,3-d]pyrimidines derivatives as DYRK1A inhibitors by means of comprehensive computational approaches involving molecular docking, molecular dynamics simulation, free energy calculation, and energy decomposition analysis. The calculated energy values were highly consistent with the experimental activities. Based on the individual energy terms analysis, the van der Waals interaction was the major leading force in the DYRK1A-ligand interaction. Lys188 was the important residue that formed the hydrogen bond, which improved the inhibitory activity. Furthermore, four novel inhibitors with higher predicted activity were designed based on the obtained findings and confirmed by molecular simulations. Our study is expected to provide significant drug design strategy for the development of more promising DYRK1A inhibitors. Proteins 2016; 84:1108-1123. © 2016 Wiley Periodicals, Inc.


Assuntos
Simulação de Dinâmica Molecular , Inibidores de Proteínas Quinases/química , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/antagonistas & inibidores , Pirimidinas/química , Sítios de Ligação , Humanos , Ligação de Hidrogênio , Cinética , Ligantes , Simulação de Acoplamento Molecular , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Proteínas Serina-Treonina Quinases/química , Estrutura Secundária de Proteína , Proteínas Tirosina Quinases/química , Relação Estrutura-Atividade , Termodinâmica , Quinases Dyrk
16.
Macromol Rapid Commun ; 37(21): 1735-1741, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27647653

RESUMO

A one-pot method is introduced for the successful synthesis of narrow-distributed (D = 1.22) vinyl polymer with both ultrahigh molecular weight (UHMW) (M w = 1.31 × 106 g mol-1 ) and micro-/nanomorphology under mild conditions. The method involves the following four stages: homogeneous polymerization, polymerization-induced self-assembly (PISA), PISA and reorganization, and PISA and multiple reorganizations. The key points to the production of UHMW polystyrene are to minimize radical termination by segregating radicals in different nanoreactors and to ensure sufficient chain propagation by promoting further reorganizations of these reactors in situ. This method therefore endows polymeric materials with the outstanding properties of both UHMW and tunable micro-/nanoparticles under mild conditions in one pot.


Assuntos
Nanopartículas/química , Polimerização , Polímeros/química , Polímeros/síntese química , Radicais Livres/química , Peso Molecular , Tamanho da Partícula , Propriedades de Superfície
17.
Bioelectromagnetics ; 37(4): 244-55, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27061713

RESUMO

Magnetic field exposure is an accepted safe and effective modality for nerve injury. However, it is clinically used only as a supplement or salvage therapy at the later stage of treatment. Here, we used a planarian Girardia sinensis decapitated model to investigate beneficial effects of early rotary non-uniform magnetic fields (RMFs) exposure on central nervous regeneration. Our results clearly indicated that magnetic stimulation induced from early RMFs exposure significantly promoted neural regeneration of planarians. This stimulating effect is frequency and intensity dependent. Optimum effects were obtained when decapitated planarians were cultured at 20 °C, starved for 3 days before head-cutting, and treated with 6 Hz 0.02 T RMFs. At early regeneration stage, RMFs exposure eliminated edema around the wound and facilitated subsequent formation of blastema. It also accelerated cell proliferation and recovery of neuron functionality. Early RMFs exposure up-regulated expression of neural regeneration related proteins, EGR4 and Netrin 2, and mature nerve cell marker proteins, NSE and NPY. These results suggest that RMFs therapy produced early and significant benefit in central nervous regeneration, and should be clinically used at the early stage of neural regeneration, with appropriate optimal frequency and intensity.


Assuntos
Sistema Nervoso Central/fisiologia , Campos Magnéticos , Regeneração Nervosa , Planárias/fisiologia , Rotação , Animais , Biomarcadores/metabolismo , Regulação da Expressão Gênica , Temperatura , Fatores de Tempo
18.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(3): 686-90, 2016 Mar.
Artigo em Zh | MEDLINE | ID: mdl-27400506

RESUMO

Titanium and titanium alloys have been widely used as orthopedic, dental implants and cardiovascular stents owing to their superior physical properties. However, titanium surface is inherently bio-inert, thus could not form efficient osseointegration with surrounding bone tissue. Therefore, to improve the surface property of titanium implant is significantly important in clinical application. Manganese and fluorine co-doped hydroxyapatite (FMnHAP) coatings were prepared on titanium substrate by electrochemical deposition technique. The as-prepared coatings were examined by scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) tests. The results indicated that the FMnHAP coatings take the morphology of nanoscale-villous-like, the composite coating becomes more compact. The FTIR test indicated that the symmetry of bending vibration modes of hydroxyl changed, simulated body fluid immersion test proved that the FMnHAP coatings had induce carbonate-apatite formation, indicating that the composite coating possess excellent biocompatibility. In the electrochemical corrosion testing, the FMnHAP coatings showed stronger corrosion resistance than pure Ti.


Assuntos
Materiais Revestidos Biocompatíveis/química , Durapatita/química , Flúor/química , Manganês/química , Titânio , Apatitas/química , Líquidos Corporais , Corrosão , Técnicas Eletroquímicas , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Difração de Raios X
19.
J Sep Sci ; 38(24): 4187-95, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26456358

RESUMO

Shuanghuanlian oral liquid, a traditional Chinese medicine preparation, is a mixture of three herbs (Flos Lonicerae, Radix Scutellariae and Fructus Forsythiae). In this study, the quantitative analysis of three main active compounds, chlorogenic acid, forsythin and baicalin in samples from different manufacturers was performed rapidly by high-performance liquid chromatography coupled with photodiode array detection followed by Contour Projection coupled to stepwise regression treatment of the obtained three-dimensional spectra in which the partial overlap between adjacent target components existed. The method was validated for linearity (R>0.9940), precision (RSD<1.25%), recovery (92.20-102.50%), limit of detection (0.01-0.02 µg/mL) and limit of quantification (0.03-0.07 µg/mL). The results indicated that the combination of the three-dimensional spectra of traditional Chinese medicine and Contour Projection-stepwise regression offered an accurate, simple, low-cost and eco-friendly way for the rapid quantitative analysis of Shuanghuanlian oral liquid samples.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/análise , Técnicas de Química Analítica/métodos , Cromatografia Líquida de Alta Pressão , Medicamentos de Ervas Chinesas/química , Flavonoides/análise , Furanos/análise , Administração Oral , Compostos Bicíclicos Heterocíclicos com Pontes/química , Técnicas de Química Analítica/instrumentação , Ácido Clorogênico/química , Cromatografia Líquida de Alta Pressão/economia , Flavonoides/química , Furanos/química , Modelos Lineares , Reprodutibilidade dos Testes , Fatores de Tempo
20.
J Sep Sci ; 38(9): 1449-57, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25677722

RESUMO

The application of chemometric methods could decrease the requirements of separation and simplify time-consuming pretreatment and experimental optimization. In this report, the accumulated projection method was developed and utilized for the rapid simultaneous quantification of four active components (notoginsenoside R1, ginsenosides Rg1, ginsenosides Re, and ginsenosides Rb1) in Sanqi Panax Notoginseng Injection samples. The proposed method is based on the three-dimensional fingerprint spectra obtained from high-performance liquid chromatography coupled with photodiode array detection. Although the chromatograms consisted of overlapping peaks, retention time shifts, and unknown interference, all established models showed good linearity (R > 0.9869) within test ranges. The relative standard deviation for intra- and interday precision of the four compounds did not exceed 2.4 and 4.7%, respectively, and the overall recovery was 91.2-106.8%. Compared with N-way principal component analysis, our method provides more satisfactory results, which indicate that the proposed approach is simple, fast, and reliable for the determination of the four analytes in Sanqi Panax Notoginseng Injection samples.


Assuntos
Medicamentos de Ervas Chinesas/química , Ginsenosídeos/análise , Algoritmos , Cromatografia Líquida de Alta Pressão , Conformação Molecular , Estereoisomerismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA