Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 69
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Anal Chem ; 93(41): 14014-14023, 2021 10 19.
Artículo en Inglés | MEDLINE | ID: mdl-34607426

RESUMEN

An atomic-level Au nanocluster, as an excellent photocatalyst, is generally not considered as an efficient electrocatalyst due to its poor stability. Herein, a method is proposed to stabilize abundant Au25 on Fe2O3 nanoplates (Au25/OV-Fe2O3) successfully with oxygen vacancies (OV) created. Au25/OV-Fe2O3 shows superhigh catalysis in the electrochemical reduction toward As(III). The record-breaking sensitivity (161.42 µA ppb-1) is two orders of magnitude higher than currently reported, where an ultratrace limit of detection (9 ppt) is obtained, suggesting promising applications in the analysis of organic and bioactive substances. The stability of Au25 is attributed to the Au-Fe bond formed after loading Au25 nanoclusters on Fe2O3 nanoplates through "electron compensation" and bond length (Au-S) shortening. Moreover, the ligand S atoms in Au25 nanoclusters significantly contribute to the reduction of As(III). The fantastic stability and superior catalytic ability of Au25/OV-Fe2O3 provide guidelines to stabilize Au nanoclusters on metal oxides, indicating their potential electroanalytical applications.


Asunto(s)
Oro , Oxígeno , Catálisis , Ligandos
2.
Anal Chem ; 92(24): 16089-16096, 2020 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-33166462

RESUMEN

Modulating the active sites of oxygen vacancies (OVs) to enhance the catalytic properties of nanomaterials has attracted much research interest in various fields, but its intrinsic catalytic mechanism is always neglected. Herein, we establish an efficient strategy to promote the electrochemical detection of Pb(II) by regulating the concentration of OVs in α-MoO3 nanorods via doping Ce3+/Ce4+ ions. α-MoO3 with the Ce-doped content of 9% (C9M) exhibited the highest detection sensitivity of 106.64 µM µA-1 for Pb(II), which is higher than that achieved by other metal oxides and most precious metal nanomaterials. It is found that C9M possessed the highest concentration of OVs, which trapped some electrons for strong affinity interaction with Pb(II) and provided numerous atomic level interfaces of high surface free energy for catalysis reactions. X-ray absorption fine structure spectra and density functional theory calculation indicate that Pb(II) was bonded with the surface-activated oxygen atoms (Os) around Ce ions and obtained some electrons from Os. Besides, the longer Pb-O bonds on C9M were easier to break, causing a low desorption energy barrier to effectively accelerate Pb(II) desorbing to the electrode surface. This study helps to understand the changes in electronic structure and catalytic performance with heteroatom doping and OVs in chemically inert oxides and provide a reference for designing high-active electrocatalytic interfaces to realize ultrasensitive analysis of environmental contaminants.

3.
J Integr Neurosci ; 19(3): 459-467, 2020 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-33070525

RESUMEN

Depression is closely linked to hypothalamus-pituitary-adrenal axis hyperactivity. Honokiol, a biphenolic lignan compound obtained from the traditional Chinese medicine Magnolia officinalis, can reduce the activity of the hypothalamus-pituitary-adrenal axis and improve depression-like behavior caused by hypothalamus-pituitary-adrenal axis hyperactivity. The current study investigated the specific mechanism of action of this effect. A depression model was established by repeated injections of corticosterone to study the antidepressant-like effect of honokiol and its potential mechanism. Honokiol prevented the elevated activity of the hypothalamus-pituitary-adrenal axis and the depression-like behavior induced by corticosterone. Treatment with honokiol resulted in greater glucocorticoid receptor mRNA expression, greater glucocorticoid receptor-positive expression, and a greater ratio of glucocorticoid receptor to the mineralocorticoid receptor in the hippocampus. Moreover, honokiol treatment led to lower levels of interleukin-1ß in serum and the positive expression of the interleukin-1ß receptor in the hippocampus. These results demonstrate that the antidepressant-like mechanism of honokiol, which has effects on inflammatory factors, may act through restoring the typical activity of the hypothalamus-pituitary-adrenal axis by regulating the glucocorticoid receptor-mediated negative feedback mechanism and the balance between glucocorticoid and mineralocorticoid receptors.


Asunto(s)
Antidepresivos/administración & dosificación , Compuestos de Bifenilo/administración & dosificación , Depresión/metabolismo , Depresión/prevención & control , Lignanos/administración & dosificación , Animales , Corticosterona/administración & dosificación , Depresión/inducido químicamente , Modelos Animales de Enfermedad , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Masculino , Mineralocorticoides/metabolismo , ARN Mensajero/metabolismo , Ratas Sprague-Dawley , Receptores de Mineralocorticoides/metabolismo
4.
Molecules ; 24(11)2019 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-31141940

RESUMEN

There is growing evidence that neuroinflammation is closely linked to depression. Honokiol, a biologically active substance extracted from Magnolia officinalis, which is widely used in traditional Chinese medicine, has been shown to exert significant anti-inflammatory effects and improve depression-like behavior caused by inflammation. However, the specific mechanism of action of this activity is still unclear. In this study, the lipopolysaccharide (LPS) mouse model was used to study the effect of honokiol on depression-like behavior induced by LPS in mice and its potential mechanism. A single administration of LPS (1 mg/kg, intraperitoneal injection) increased the immobility time in the forced swimming test (FST) and tail suspension test (TST), without affecting autonomous activity. Pretreatment with honokiol (10 mg/kg, oral administration) for 11 consecutive days significantly improved the immobility time of depressed mice in the FST and TST experiments. Moreover, honokiol ameliorated LPS-induced NF-κB activation in the hippocampus and significantly reduced the levels of the pro-inflammatory cytokines; tumor necrosis factor α (TNF-α), interleukin 1ß (IL-1ß), and interferon γ (IFN-γ). In addition, honokiol inhibited LPS-induced indoleamine 2,3-dioxygenase (IDO) activation and quinolinic acid (a toxic product) increase and reduced the level of free calcium in brain tissue, thereby inhibiting calcium overload. In summary, our results indicate that the anti-depressant-like effects of honokiol are mediated by its anti-inflammatory effects. Honokiol may inhibit the LPS-induced neuroinflammatory response through the NF-κB signaling pathway, reducing the levels of related pro-inflammatory cytokines, and furthermore, this may affect tryptophan metabolism and increase neuroprotective metabolites.


Asunto(s)
Antidepresivos/uso terapéutico , Compuestos de Bifenilo/uso terapéutico , Depresión/tratamiento farmacológico , Lignanos/uso terapéutico , Animales , Antidepresivos/farmacología , Sistema Nervioso Autónomo/efectos de los fármacos , Compuestos de Bifenilo/farmacología , Encéfalo/metabolismo , Calcio/metabolismo , Citocinas/sangre , Depresión/fisiopatología , Modelos Animales de Enfermedad , Suspensión Trasera , Inmovilización , Indolamina-Pirrol 2,3,-Dioxigenasa/genética , Indolamina-Pirrol 2,3,-Dioxigenasa/metabolismo , Mediadores de Inflamación/sangre , Quinurenina/metabolismo , Lignanos/farmacología , Lipopolisacáridos , Ratones Endogámicos ICR , FN-kappa B/genética , FN-kappa B/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Natación , Triptófano/metabolismo
5.
Angew Chem Int Ed Engl ; 58(38): 13390-13393, 2019 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-31321862

RESUMEN

In response to ever-increasing application requirements in lighting and displays, a tremendous emphasis is being placed on single-component white-light emission. Single-component inorganic borates doped with rare earth metal ions have shown prominent achievements in white-light emission. The first environmentally friendly defect-induced white-light emitting crystalline inorganic borate, Ba2 [Sn(OH)6 ][B(OH)4 ]2 , has been prepared. Additionally, it is the first borate-stannate without a Sn-O-B linkage. Notably, Ba2 [Sn(OH)6 ][B(OH)4 ]2 shows Commission Internationale de l'Eclairage (CIE) chromaticity coordinates of (0.42, 0.38), an ultrahigh color rendering index (CRI) of 94.1, and an appropriate correlated color temperature (CCT) of 3083 K. Such a promising material will provide a new approach in the development of white-light emitting applications.

6.
Protein Expr Purif ; 130: 63-72, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-27725246

RESUMEN

As the first step of ongoing efforts to investigate the genes responsible for the biosynthesis of steroidal saponins in the medicinal plant Ornithogalum caudatum, this investigation reported the cDNA isolation, prokaryotic expression and functional characterization of squalene synthase (SQS) gene from O. caudatum for the first time. Specifically, two unigenes showing high sequence identity to SQS were retrieved from RNA-Taq data, and then a full-length OcSQS1 corresponding to the two unigenes was isolated from O. caudatum genome by a nested PCR assay. The open reading frame of OcSQS1 was 1230 bp and encoded a polypeptide of 409 aa. OcSQS1 was predicted to be a membrane-bound protein with at least four conserved motifs associated with binding, regulatory and catalytic activities of OcSQS1 and two transmembrane domains. Next, many attempts to generate soluble OcSQS1 in heterologous Escherichia coli were made, including optimization of expression conditions, application of varied expression plasmids with different tags, secretory peptides and molecular chaperones, and truncated mutation of OcSQS1. Finally, the successful availability of a soluble, truncated OcSQS1 mutant was achieved by combinational use of the utensils from the vast genetic toolbook. Moreover, this truncated OcSQS1 mutant retained the folding capability as well as its catalytic activity, converting FPP to form squalene. Importantly, the present research tentatively verified the involvement of the second transmembrane domain in the proper folding of the recombinant OcSQS1 protein.


Asunto(s)
Clonación Molecular , ADN Complementario , Escherichia coli/metabolismo , Farnesil Difosfato Farnesil Transferasa , Ornithogalum/genética , Proteínas de Plantas , ADN Complementario/genética , ADN Complementario/aislamiento & purificación , Escherichia coli/genética , Farnesil Difosfato Farnesil Transferasa/biosíntesis , Farnesil Difosfato Farnesil Transferasa/química , Farnesil Difosfato Farnesil Transferasa/genética , Farnesil Difosfato Farnesil Transferasa/aislamiento & purificación , Ornithogalum/enzimología , Proteínas de Plantas/biosíntesis , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/aislamiento & purificación , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/aislamiento & purificación
7.
Sheng Li Xue Bao ; 69(5): 703-714, 2017 Oct 25.
Artículo en Zh | MEDLINE | ID: mdl-29063118

RESUMEN

DREAM (downstream regulatory element antagonist modulator), Calsenilin and KChIP3 (potassium channel interacting protein 3) belong to the neuronal calcium sensor (NCS) superfamily, which transduces the intracellular calcium signaling into a variety of activities. They are encoded by the same gene locus, but have distinct subcellular locations. DREAM was first found to interact with DRE (downstream regulatory element) site in the vicinity of the promoter of prodynorphin gene to suppress gene transcription. Calcium can disassemble this interaction by binding reversibly to DREAM protein on its four EF-hand motifs. Apart from having calcium dependent DRE site binding, DREAM can also interact with other transcription factors, such as cAMP responsive element binding protein (CREB), CREB-binding protein (CBP) and cAMP responsive element modulator (CREM), by this concerted actions, DREAM extends the gene pool under its control. DREAM is predominantly expressed in central nervous system with its highest level in cerebellum, and accumulating evidence demonstrated that DREAM might play important roles in pain sensitivity. Novel findings have shown that DREAM is also involved in learning and memory processes, Alzheimer's disease and stroke. This mini-review provides a brief introduction of its discovery history and protein structure properties, focusing on the mechanism of DREAM nuclear translocation and gene transcription regulation functions.


Asunto(s)
Regulación de la Expresión Génica , Proteínas de Interacción con los Canales Kv/fisiología , Proteínas Represoras/fisiología , Animales , Señalización del Calcio/fisiología , Humanos , Proteínas de Interacción con los Canales Kv/genética , Umbral del Dolor , Proteínas Represoras/genética
8.
Anal Chem ; 88(1): 906-14, 2016 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-26639029

RESUMEN

Iron oxide with different crystal phases (α- and γ-Fe2O3) has been applied to electrode coatings and been demonstrated to ultrasensitive and selective electrochemical sensing toward heavy metal ions (e.g., Pb(II)). A range of Pb(II) contents in micromoles (0.1 to 1.0 µM) at α-Fe2O3 nanoflowers with a sensitivity of 137.23 µA µM(-1) cm(-2) and nanomoles (from 0.1 to 1.0 nM) at γ-Fe2O3 nanoflowers with a sensitivity of 197.82 µA nM(-1) cm(-2) have been investigated. Furthermore, an extended X-ray absorption fine structure (EXAFS) technique was applied to characterize the difference of local structural environment of the adsorbed Pb(II) on the surface of α- and γ-Fe2O3. The results first showed that α- and γ-Fe2O3 had diverse interaction between Pb(II) and iron (hydro)oxides, which were consistent with the difference of electrochemical performance. Determining the responses of Cu(II) and Hg(II) as the most appropriate choice for comparison, the stripping voltammetric quantification of Pb(II) with high sensitivity and selectivity at γ-Fe2O3 nanoflower has been demonstrated. This work reveals that the stripping performances of a nanomodifier have to be directly connected with its intrinsic surface atom arrangement.


Asunto(s)
Técnicas Electroquímicas , Compuestos Férricos/química , Plomo/análisis , Cristalización , Espectroscopía de Fotoelectrones , Espectroscopía de Absorción de Rayos X
9.
Microb Cell Fact ; 15: 27, 2016 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-26846670

RESUMEN

BACKGROUND: (2S)-Pinocembrin is a chiral flavanone with versatile pharmacological and biological activities. Its health-promoting effects have spurred on research effects on the microbial production of (2S)-pinocembrin. However, an often-overlooked salient feature in the analysis of microbial (2S)-pinocembrin is its chirality. RESULTS: Here, we presented a full characterization of absolute configuration of microbial (2S)-pinocembrin from engineered Escherichia coli. Specifically, a transcriptome-wide search for genes related to (2S)-pinocembrin biosynthesis from Ornithogalum caudatum, a plant rich in flavonoids, was first performed in the present study. A total of 104,180 unigenes were finally generated with an average length of 520 bp. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway mapping assigned 26 unigenes, representing three enzyme families of 4-coumarate:coenzyme A ligase (4CL), chalcone synthase (CHS) and chalcone isomerase(CHI), onto (2S)-pinocembrin biosynthetic pathway. A total of seven, three and one full-length candidates encoding 4CL, CHS and CHI were then verified by reverse transcription polymerase chain reaction, respectively. These candidates were screened by functional expression in E. coli individual or coupled multienzyme reaction systems based on metabolic engineering processes. Oc4CL1, OcCHS2 and OcCHI were identified to be bona fide genes encoding respective pathway enzymes of (2S)-pinocembrin biosynthesis. Then Oc4CL1, OcCHS2 and MsCHI from Medicago sativa, assembled as artificial gene clusters in different organizations, were used for fermentation production of (2S)-pinocembrin in E. coli. The absolute configuration of the resulting microbial pinocembrin at C-2 was assigned to be 2S-configured by combination of retention time, UV spectrum, LC-MS, NMR, optical rotation and circular dichroism spectroscopy. Improvement of (2S)-pinocembrin titres was then achieved by optimization of gene organizations, using of codon-optimized pathway enzymes and addition of cerulenin for increasing intracellular malonyl CoA pools. Overall, the optimized strain can produce (2S)-pinocembrin of 36.92 ± 4.1 mg/L. CONCLUSIONS: High titre of (2S)-pinocembrin can be obtained from engineered E. coli by an efficient method. The fermentative production of microbial (2S)-pinocembrin in E. coli paved the way for yield improvement and further pharmacological testing.


Asunto(s)
Vías Biosintéticas/genética , Flavanonas/metabolismo , Ingeniería Metabólica/métodos , Ornithogalum/enzimología , Ornithogalum/genética , Transcriptoma/genética , Espectroscopía de Resonancia Magnética con Carbono-13 , Cromatografía Líquida de Alta Presión , Dicroismo Circular , ADN Complementario/genética , ADN Complementario/aislamiento & purificación , Fermentación , Flavanonas/química , Regulación de la Expresión Génica de las Plantas , Familia de Multigenes , Espectroscopía de Protones por Resonancia Magnética , Proteínas Recombinantes/metabolismo
10.
Molecules ; 21(11)2016 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-27834878

RESUMEN

d-Galacturonic acid (GalA) is an important component of GalA-containing polysaccharides in Ornithogalum caudatum. The incorporation of GalA into these polysaccharides from UDP-d-galacturonic acid (UDP-GalA) was reasonably known. However, the cDNAs involved in the biosynthesis of UDP-GalA were still unknown. In the present investigation, one candidate UDP-d-glucuronic acid 4-epimerase (UGlcAE) family with three members was isolated from O. caudatum based on RNA-Seq data. Bioinformatics analyses indicated all of the three isoforms, designated as OcUGlcAE1~3, were members of short-chain dehydrogenases/reductases (SDRs) and shared two conserved motifs. The three full-length cDNAs were then transformed to Pichia pastoris GS115 for heterologous expression. Data revealed both the supernatant and microsomal fractions from the recombinant P. pastoris expressing OcUGlcAE3 can interconvert UDP-GalA and UDP-d-glucuronic acid (UDP-GlcA), while the other two OcUGlcAEs had no activity on UDP-GlcA and UDP-GalA. Furthermore, expression analyses of the three epimerases in varied tissues of O. caudatum were performed by real-time quantitative PCR (RT-qPCR). Results indicated OcUGlcAE3, together with the other two OcUGlcAE-like genes, was root-specific, displaying highest expression in roots. OcUGlcAE3 was UDP-d-glucuronic acid 4-epimerase and thus deemed to be involved in the biosynthesis of root polysaccharides. Moreover, OcUGlcAE3 was proposed to be environmentally induced.


Asunto(s)
Carbohidrato Epimerasas , ADN Complementario , Ornithogalum , Proteínas de Plantas , Raíces de Plantas , Carbohidrato Epimerasas/biosíntesis , Carbohidrato Epimerasas/genética , Expresión Génica , Ornithogalum/enzimología , Ornithogalum/genética , Pichia , Proteínas de Plantas/biosíntesis , Proteínas de Plantas/genética , Raíces de Plantas/enzimología , Raíces de Plantas/genética , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/genética , Azúcares de Uridina Difosfato/genética , Azúcares de Uridina Difosfato/metabolismo
11.
Angew Chem Int Ed Engl ; 55(16): 4967-71, 2016 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-26971863

RESUMEN

A low-temperature topochemical reduction strategy is used herein to prepare unconventional phosphors with luminescence covering the biological and/or telecommunications optical windows. This approach is demonstrated by using Bi(III)-doped Y2O3 (Y(2-x)Bi(x)O3) as a model system. Experimental results suggest that topochemical treatment of Y(2-x)Bi(x)O3 using CaH2 creates randomly distributed oxygen vacancies in the matrix, resulting in the change of the oxidation states of Bi to lower oxidation states. The change of the Bi coordination environments from the [BiO6] octahedra in Y(2-x)Bi(x)O3 to the oxygen-deficient [BiO(6-z)] polyhedra in reduced phases leads to a shift of the emission maximum from the visible to the near-infrared region. The generality of this approach was further demonstrated with other phosphors. Our findings suggest that this strategy can be used to explore Bi-doped or other classes of luminescent systems, thus opening up new avenues to develop novel optical materials.

12.
Appl Environ Microbiol ; 81(19): 6548-57, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26162881

RESUMEN

Bacillus thuringiensis produces chitinases, which are involved in its antifungal activity and facilitate its insecticidal activity. In our recent work, we found that a 16-bp sequence, drechiB (AGACTTCGTGATGTCT), downstream of the minimal promoter region of the chitinase B gene (chiB) was a critical site for the inducible expression of chiB in B. thuringiensis Bti75. In this work, we show that a GntR family transcriptional regulator (named YvoABt), which is homologous to YvoA of Bacillus subtilis, can specifically bind to the drechiB oligonucleotide sequences in vitro by using electrophoretic mobility shift assays (EMSAs) and isothermal titration calorimetry (ITC) assays. The results of quantitative real-time reverse transcription-PCR (qRT-PCR) and Western blotting indicated that deletion of yvoA caused an ∼7.5-fold increase in the expression level of chiB. Furthermore, binding of purified YvoABt to its target DNA could be abolished by glucosamine-6-phosphate (GlcN-6-P). We also confirmed, in the presence of the phosphoprotein Hpr-Ser45-P, that purified CcpABt bound specifically to the promoter of chiB, which contains the "crechiB" sequence (ATAAAGCGTTTACA). According to the results of qRT-PCR and Western blotting, deletion of ccpA resulted in a 39-fold increase in the chiB expression level, and glucose no longer influenced the expression of chiB. We confirm that chiB is negatively controlled by both CcpABt and YvoABt in Bti75.


Asunto(s)
Bacillus thuringiensis/enzimología , Quitinasas/genética , Regulación hacia Abajo , Proteínas Represoras/metabolismo , Bacillus thuringiensis/genética , Bacillus thuringiensis/metabolismo , Proteínas Bacterianas/genética , Quitinasas/metabolismo , Regulación Bacteriana de la Expresión Génica , Regiones Promotoras Genéticas , Proteínas Represoras/genética
13.
Chin Med Sci J ; 29(4): 204-7, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25429743

RESUMEN

OBJECTIVE: To assess the agreement between gonioscopy and ultrasound biomicroscopy (UBM) in detecting angle closure in Chinese patients with shallow anterior chamber. METHODS: An observational comparative study of the two different examination methods was conducted. Patients with normal intraocular pressure and temporal peripheral anterior chamber depth less than a quarter of corneal thickness based on slit lamp examination were included in this study from December 2007 to May 2009 in the outpatient clinic of First Hospital of Tsinghua University. Gonioscopy was performed with a Goldman goniolens in dark room first and followed by full beam light and indentation. If the filtering trabecular meshwork was invisible or any peripheral anterior synechia was found, that quadrant of the angle was considered closed. UBM was first undertaken in a darkened room then repeated with normal room lighting. If iridotrabecular apposition was showed, that quadrant of the angle was considered closed. The status of angle closure of each quadrant with different methods was recorded. RESULTS: 85 eyes of 46 patients were included in this study. The agreement between gonioscopy and UBM was poor (Κ<0.4) with Kappa analysis in both dark and light conditions in each quadrant. The accordance of agreement between gonioscopy and UBM was hardly affected by age or sex, while in dark condition, eyes with deeper anterior chamber (P=0.005) or plateau iris configuration tended to produce different results (P=0.075) in the 2 methods. CONCLUSION: Gonioscopy and UBM are both indispensable methods for detecting angle closure, neither can completely replace the other.


Asunto(s)
Glaucoma de Ángulo Cerrado/diagnóstico , Gonioscopía/métodos , Humanos
14.
Zhong Yao Cai ; 37(10): 1789-92, 2014 Oct.
Artículo en Zh | MEDLINE | ID: mdl-25895384

RESUMEN

OBJECTIVE: To study the chemical constituents of Ligularia songarica. METHODS: Isolation and purification were carried out on repeated silica gel column chromatography. The compounds structures were identified by physico-chemical properties and spectral analyses. RESULTS: Ten compounds were isolated and identified as benzofuranoeremophil-2-ene (1), 6-angeloyloxy-1,10-epoxy-euryopsin (2), 2-hydroxyplatyphyllide (3), 1ß-hydroxy-6,9-dien-8-oxoeremophy-11-nor-11-ketone (4), 2-isopropenyl-6-acetyl-8-methoxy-13-benzodioxin-4-one (5), 1ß-hydroxy-6,9-dien-8-oxo-11-nor-11-hydroxyeremophilane (6), isopetasin (7), 6ß,10α-dihydroxy-1-oxoeremophila-7 (11), 8(9)-diene-8,12-olide (8), 10α-hydroxy-1-oxo-eremophila-7 (11), 8(9)-diene-8,12-olide (9) and 6ß-angeloyloxy-1ß,10ß-epoxy-9-oxo-furaneremophilane (10). CONCLUSION: Compounds 2-9 are obtained from this plant for the first time.


Asunto(s)
Asteraceae/química , Fitoquímicos/aislamiento & purificación , Sesquiterpenos/aislamiento & purificación
15.
Bioorg Med Chem Lett ; 23(19): 5339-50, 2013 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-23953188

RESUMEN

Aggrecanases-2 is a very important potential drug target for the treatment of osteoarthritis. In this study, a series of known aggrecanases-2 inhibitors was analyzed by the technologies of three-dimensional quantitative structure-activity relationships (3D-QSAR) and molecular docking. Two 3D-QSAR models, which based on comparative molecular field analysis (CoMFA) and comparative molecular similarity analysis (CoMSIA) methods, were established. Molecular docking was employed to explore the details of the interaction between inhibitors and aggrecanases-2 protein. According to the analyses for these models, several new potential inhibitors with higher activity predicted were designed, and were supported by the simulation of molecular docking. This work propose the fast and effective approach to design and prediction for new potential inhibitors, and the study of the interaction mechanism provide a better understanding for the inhibitors binding into the target protein, which will be useful for the structure-based drug design and modifications.


Asunto(s)
Proteínas ADAM/antagonistas & inhibidores , Simulación por Computador , Diseño de Fármacos , Inhibidores Enzimáticos/química , Proteína ADAMTS5 , Activación Enzimática/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Humanos , Modelos Moleculares , Unión Proteica/efectos de los fármacos , Relación Estructura-Actividad Cuantitativa
16.
Yao Xue Xue Bao ; 48(2): 228-35, 2013 Feb.
Artículo en Zh | MEDLINE | ID: mdl-23672019

RESUMEN

Synthetic biology of natural products is the design and construction of new biological systems by transferring a metabolic pathway of interest products into a chassis. Large-scale production of natural products is achieved by coordinate expression of multiple genes involved in genetic pathway of desired products. Promoters are cis-elements and play important roles in the balance of the metabolic pathways controlled by multiple genes by regulating gene expression. A detection plasmid of Saccharomyces cerevisiae was constructed based on DsRed-Monomer gene encoding for a red fluorescent protein. This plasmid was used for screening the efficient promoters applying for multiple gene-controlled pathways. First of all, eight pairs of primers specific to DsRed-Monomer gene were synthesized. The rapid cloning of DsRed-Monomer gene was performed based on step-by-step extension of a short region of the gene through a series of PCR reactions. All cloned sequences were confirmed by DNA sequencing. A vector named pEASYDs-M containing full-length DsRed-Monomer gene was constructed and was used as the template for the construction of S. cerevisiae expression vector named for pYeDP60-Ds-M. pYeDP60-Ds-M was then transformed into S. cerevisiae for heterologous expression of DsRed-Monomer gene. SDS-PAGE, Western blot and fluorescence microscopy results showed that the recombinant DsRed-Monomer protein was expressed successfully in S. cerevisiae. The well-characterized DsRed-Monomer gene was then cloned into a yeast expression vector pGBT9 to obtain a promoter detection plasmid pGBT9Red. For determination efficacy of pGBT9Red, six promoters (including four inducible promoters and two constitutive promoters) were cloned by PCR from the S. cerevisiae genome, and cloned into pGBT9Red by placing upstream of DsRed-Monomer gene, separately. The fluorescence microscopy results indicated that the six promoters (GAL1, GAL2, GAL7, GAL10, TEF2 and PGK1) can regulate the expression of DsRed-Monomer gene. The successful construction of pGBT9Red lays the foundation for further analysis of promoter activity and screening of promoter element libraries.


Asunto(s)
Proteínas Luminiscentes/genética , Plásmidos/genética , Regiones Promotoras Genéticas/genética , Saccharomyces cerevisiae/genética , Biología Sintética , Secuencia de Aminoácidos , Secuencia de Bases/genética , Clonación Molecular , Cartilla de ADN/biosíntesis , Regulación Fúngica de la Expresión Génica , Vectores Genéticos , Proteínas Luminiscentes/metabolismo , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/genética , Saccharomyces cerevisiae/metabolismo , Transformación Genética , Proteína Fluorescente Roja
17.
J Matern Fetal Neonatal Med ; 36(1): 2209818, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37286223

RESUMEN

BACKGROUND: Transcervical resection of adhesion (TCRA) and postoperative adjuvant estrogen and progestin are the main treatments for cavity adhesions, but the recurrence rate after surgery is still high. It was showed that aspirin could promote endometrial proliferation and repair after TCRA in patients with severe cavity adhesions, but the effect on reproduction was uncertain. OBJECTIVE: To assess the effect of aspirin on uterine arterial blood flow and endometrium in moderate and severe intrauterine adhesion after transcervical resection of adhesion. METHODS: The databases used included Cumulative Index to PubMed, EMBASE, Chinese National Knowledge Infrastructure (CNKI), and Wanfang database. Studies published before June 2022 were included. Each participant received an aspirin-based intervention aimed at improving uterine status, which was compared to a sham intervention. The primary outcome measure was a change in endometrium thickness. Secondary outcomes included uterine artery resistance index, blood flow index, and endometrial arterial resistance index. RESULT: A total of 19 studies (n = 1361 participants) that met the inclusion criteria were included in this study. The aspirin-based intervention was strongly associated with better clinical outcome at second-look endometrium thickness (MD 0.81, CI 0.46-1.16; p < .00001) and blood flow Index (FI) (MD 4.1, CI 2.3-5.9; p < .00001). Besides, the analysis of arterial pulsatility index (PI) showed a significantly reduced after transcervical resection of adhesion (MD -0.9, CI -1.2 to 0.6; p < .00001); whereas no significant difference was found in endometrial arterial resistance index (RI) (95% CI, -0.30 to 0.01; p = .07). CONCLUSION: Our study proved the effect of aspirin on uterine arterial blood flow and endometrium in moderate and severe intrauterine adhesion after transcervical resection of adhesion. However, the review requires evidence from additional randomized controlled trials and high-quality research. More strictly designed research studies are needed to assess the effectiveness of aspirin administration after transcervical resection of adhesion.


Asunto(s)
Aspirina , Enfermedades Uterinas , Femenino , Humanos , Aspirina/farmacología , Aspirina/uso terapéutico , Arteria Uterina/cirugía , Endometrio/cirugía , Útero/cirugía
18.
Artículo en Zh | MEDLINE | ID: mdl-23072159

RESUMEN

OBJECTIVE: To evaluate the efficacy of tribendimidine (TBD) against 3 geographical isolates of Trichinella spiralis in mice. METHODS: Isolates of T. spiralis from Henan (hereinafter referred to as HnT.s), Yunnan (referred to as YnT.s) and Heilongjiang (referred to as HIjT.s) were used in the study. 144 Kunming strain mice were divided into 2 groups: 72 mice in group A (adult stage, treatment at 5 d after infection), and 72 mice in group B (encapsulated larva stage, treatment at 53 d after infection). Group A was further divided equally into 12 sub-groups. Mice in every 3 sub-groups were each infected orally with 200 T. spiralis larvae of the 3 isolates respectively, and the remained 3 subgroups served as untreated control. Mice in the 3 sub-groups infected with one isolate were orally treated with TBD at a single dose of 10, 20, and 30 mg/kg, respectively. Group B was treated as group A but with a course of TBD once daily at a dose of 100, 200, and 300 mg/(kg x d) for 7 d, respectively. Mice in group A were sacrificed 2 d post-treatment and adult worms were recovered from the small intestine and counted. Those in group B were sacrificed 10 d after completion of 7 d treatment. The intact diaphragm was removed and digested for collecting larvae. Worm burden and worm reduction of each treated sub-group were calculated and statistically compared with the respective control. RESULTS: In group A, the mean worm burden in the treated sub-groups infected with HnT.s and YnT.s were all significantly lower than that of the controls (P < 0.01), with a mean worm reduction rate of 39.0%, 57.9%, and 86.0% in HnT.s sub-groups, and of 34.9%, 69.3%, and 92.2% in YnT.s sub-groups, respectively, showing an increase with the dosage, 2 mice in each of the 30mg/kg sub-groups were cured. The worm burden in the 10 mg/kg of HljT.s subgroup was similar to that of the control (P > 0.05), but was significantly lower in the other 2 sub-groups than that of the controls (P < 0.01). The worm reduction rate in the 3 sub-groups was 27.9%, 57.4%, and 60.7%, respectively. In all treated sub-groups of group B, the mean worm burden was significantly lower than that of the controls (P < 0.05), with a mean worm reduction rate of 57.8%, 75.4%, and 87.5% in HnT.s sub-groups, of 74.5%, 92.4%, and 99.1% in YnT.s sub-groups, and of 50.5%, 53.3%, and 61.6% in HljT.s sub-groups, respectively, with the 3 dosages. CONCLUSION: Tribendimidine shows adequate efficacy on Trichinella spiralis adults and on encapsulated larvae of the 3 geographical isolates in mice, with better effect on Yunnan isolate.


Asunto(s)
Fenilendiaminas/uso terapéutico , Trichinella spiralis/efectos de los fármacos , Triquinelosis/tratamiento farmacológico , Animales , Modelos Animales de Enfermedad , Ratones , Ratones Endogámicos , Trichinella spiralis/clasificación , Trichinella spiralis/aislamiento & purificación , Triquinelosis/parasitología
19.
Front Psychol ; 13: 822206, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35250761

RESUMEN

Significant research has been conducted on the influence of entrepreneurial intention on entrepreneurial education and entrepreneurship practice. Similarly, this study aims to explore how creativity plays a mediating role in the influence of personality traits on entrepreneurial intention. As many as 674 valid questionnaires were collected from college students in China, allowing the relationship between personality traits, creativity, and entrepreneurial intention to be analyzed in detail. The following results are found through a series of explorations. First, neuroticism in personality traits has a significant negative impact on entrepreneurial intention, while conscientiousness, openness, and extraversion have a significant positive impact. Second, neuroticism has a significant negative impact on creativity, while conscientiousness, openness, and extraversion have a significant positive impact. Third, creativity has a significant positive impact on entrepreneurial intention, it has a partial mediating role between neuroticism, conscientiousness, extraversion, and entrepreneurial intention along with a complete mediating role between openness and entrepreneurial intention. The research results further provide a reference value for the improvement and optimization of entrepreneurial practice.

20.
J Cardiothorac Surg ; 17(1): 8, 2022 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-35034651

RESUMEN

BACKGROUND: Aortic valve replacement (AVR) for chronic aortic regurgitation (AR) with a severe dilated left ventricle and dysfunction leads to left ventricle remodeling. But there are rarely reports on the left ventricle reverse remodeling (LVRR) after AVR. This study aimed to investigate the LVRR and outcomes in chronic AR patients with severe dilated left ventricle and dysfunction after AVR. METHODS: We retrospectively analyzed the clinical datum of chronic aortic regurgitation patients who underwent isolated AVR. The LVRR was defined as an increase in left ventricular ejection fraction (LVEF) at least 10 points or a follow-up LVEF ≥ 50%, and a decrease in the indexed left ventricular end-diastolic diameter of at least 10%, or an indexed left ventricular end-diastolic diameter ≤ 33 mm/m2. The changes in echocardiographic parameters after AVR, survival analysis, the predictors of major adverse cardiac events (MACE), the association between LVRR and MACE were analyzed. RESULTS: Sixty-nine patients with severe dilated left ventricle and dysfunction underwent isolated AVR. LV remodeling in 54 patients and no LV remodeling in 15 patients at 6-12 months follow-up. The preoperative left ventricular dimensions and volumes were larger, and the EF was lower in the LV no remodeling group than those in the LV remodeling group (all p < 0.05). The adverse LVRR was the predictor for MACE at follow-up. The mean follow-up period was 47.29 months (range 6 to 173 months). The rate of freedom from MACE was 94.44% at 5 years and 92.59% at 10 years in the remodeling group, 60% at 5 years, and 46.67% at 10 years in the no remodeling group. CONCLUSIONS: The left ventricle remodeling after AVR was the important predictor for MACE. LV no remodeling may not be associated with benefits from AVR for chronic aortic regurgitation patients with severe dilated LV and dysfunction.


Asunto(s)
Insuficiencia de la Válvula Aórtica , Implantación de Prótesis de Válvulas Cardíacas , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/cirugía , Insuficiencia de la Válvula Aórtica/complicaciones , Insuficiencia de la Válvula Aórtica/diagnóstico por imagen , Insuficiencia de la Válvula Aórtica/cirugía , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/cirugía , Humanos , Estudios Retrospectivos , Volumen Sistólico , Función Ventricular Izquierda , Remodelación Ventricular
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA