Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Front Neurol ; 15: 1373306, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38952470

RESUMO

Background: Cerebral small vessel disease (CSVD) is a common neurodegenerative condition in the elderly, closely associated with cognitive impairment. Early identification of individuals with CSVD who are at a higher risk of developing cognitive impairment is crucial for timely intervention and improving patient outcomes. Objective: The aim of this study is to construct a predictive model utilizing LASSO regression and binary logistic regression, with the objective of precisely forecasting the risk of cognitive impairment in patients with CSVD. Methods: The study utilized LASSO regression for feature selection and logistic regression for model construction in a cohort of CSVD patients. The model's validity was assessed through calibration curves and decision curve analysis (DCA). Results: A nomogram was developed to predict cognitive impairment, incorporating hypertension, CSVD burden, apolipoprotein A1 (ApoA1) levels, and age. The model exhibited high accuracy with AUC values of 0.866 and 0.852 for the training and validation sets, respectively. Calibration curves confirmed the model's reliability, and DCA highlighted its clinical utility. The model's sensitivity and specificity were 75.3 and 79.7% for the training set, and 76.9 and 74.0% for the validation set. Conclusion: This study successfully demonstrates the application of machine learning in developing a reliable predictive model for cognitive impairment in CSVD. The model's high accuracy and robust predictive capability provide a crucial tool for the early detection and intervention of cognitive impairment in patients with CSVD, potentially improving outcomes for this specific condition.

2.
Opt Express ; 32(1): 313-324, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38175058

RESUMO

Magnetic-free nonreciprocal optical devices have attracted great attention in recent years. Here, we investigated the magnetic-free polarization rotation of light in an atom vapor cell. Two mechanisms of magnetic-free nonreciprocity have been realized in ensembles of hot atoms, including electromagnetically induced transparency and optically-induced magnetization. For a linearly polarized input probe light, a rotation angle up to 86.4° has been realized with external control and pump laser powers of 10 mW and is mainly attributed to the optically-induced magnetization effect. Our demonstration offers a new approach to realize nonreciprocal devices, which can be applied to solid-state atom ensembles and may be useful in photonic integrated circuits.

3.
Enzyme Microb Technol ; 173: 110368, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38043249

RESUMO

Most of the dsDNA cyanophages employ holin-endolysin lysis systems to damage the host cells. This study aimed to elucidate the lytic activity of ORF91 and ORF117 in the cyanophage MaMV-DH01, which lacked a conventional cholinesterase system. These two proteins contained Lyz-like superfamily domains and were annotated as a member of GH family 19 (named DHGH19) and peptidase (named DHpeptidase), respectively. Overexpression of DHGH19 in E. coli over a 5 h course demonstrated potent bactericidal activity, evident from significant growth inhibition, membrane damage, and leakage of intracellular enzymes of E. coli cells. However, the lytic activity of DHpeptidase was relatively weaker, exhibiting a bacteriostatic effect. It was important to highlight that the specific mutation of enzyme-catalyzed residues in DHGH19 (E122 and E131) showed that these were the essential amino acids for DHGH19 to exert its bactericidal activity. Furthermore, the lytic function of DHGH19 and DHpeptidase on cyanobacteria cells was confirmed by their overexpression in the cyanobacterium Synechocystis sp. PCC6803. Overall, this study provides novel insights into the lytic mechanism of Myoviridae cyanophage, offering potential alternatives for the development of GH19 and peptidase as new antibacterial agents in the future.


Assuntos
Bacteriófagos , Cianobactérias , Peptídeo Hidrolases , Myoviridae/metabolismo , Muramidase , Escherichia coli/genética , Escherichia coli/metabolismo , Endopeptidases/genética , Endopeptidases/metabolismo , Cianobactérias/metabolismo , Bacteriófagos/genética
4.
Zhongguo Zhong Yao Za Zhi ; 46(13): 3330-3336, 2021 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-34396752

RESUMO

The present study aimed to explore the correlation between agronomic traits and quality indexes of Dendrobium nobile and its application value in agricultural breeding. The cultivated strains of D. nobile in Hejiang-Chishui producing areas were extensively collected,and the main agronomic traits and quality indexes were measured. The agronomic traits with significant correlation with quality indexes were screened out by the correlation analysis,and then the parental lines and self-bred F_1 generation plants were furtherverified. Among 96 lines of D. nobile,the content of soluble polysaccharides showed a significant negative correlation with dendrobine( P < 0. 01),and no significant correlation with agronomic traits in stems and leaves. The content of dendrobine exhibited a significant positive correlation with the stem width-thickness ratio( at the largest cross section; P < 0. 01),and no significant correlation with other agronomic traits. Regression analysis further verified the positive correlation between dendrobine content and stem width-thickness ratio( R2> 0. 9). Two lines,JC-10 and JC-35,with significant differences in stem width-thickness ratio were screened out( P <0. 05). The corresponding F1 generation plants by self-pollination both showed that the dendrobine content was higher with greater stem width-thickness ratio( P < 0. 01). The experimental results suggested that within a certain range,the dendrobine content was higher in D. nobile with flatter stem. Therefore,in the breeding of D. nobile,this specific trait could be used for screening plants with high content of quality indexes such as dendrobine.


Assuntos
Dendrobium , Agricultura , Dendrobium/genética , Melhoramento Vegetal , Folhas de Planta/genética , Polissacarídeos
5.
Zhongguo Zhong Yao Za Zhi ; 44(4): 765-773, 2019 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-30989890

RESUMO

Dendrobium denneanum have been used for a long time as rare medicinal herbs in traditional Chinese medicine. Our previous works found that ether extract of D. denneanum had higher anticancer activities than alcohol or water extract,thus with better development prospects. Quantitative proteomics based on SILAC technique was used to investigate the anticancer mechanism of D. denneanum on lung tumor cell line A549,and 4 855 proteins were detected in A549 cells. Quantitative proteomics experiments found that 193 proteins of A549 cells were up-regulated,and 44 proteins were down-regulated by ether extract of D. denneanum. Those proteins are associated with synthesis,transport and metabolism of biological macromolecules,chaperone,DNA repair,oxidoreductase,cell adhesion,cell cycle,apoptosis and autophagy. Through the function analysis of differentially expressed proteins,it was inferred that ether extract of D. denneanum caused cell protein metabolism disorder,endoplasmic reticulum stress response,abnormal self-repair mechanism of cells,damage of cell adhesion and proliferation; besides,it caused a dramatic increase in ROS level in A549 cells,and upset the balance of intracellular oxidation reduction system. Affected by the above factors,lung cancer cells initiated apoptosis and autophagy,which accelerated cell death. This research explains the anticancer mechanism of D. denneanum from the perspective of quantitative proteomics,and lays a foundation for future research and development of new anticancer drugs based on ether extract of D. denneanum.


Assuntos
Dendrobium , Neoplasias Pulmonares , Células A549 , Animais , Apoptose , Éter , Humanos , Proteômica
6.
J Sep Sci ; 42(6): 1289-1298, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30653844

RESUMO

In this work, monoamine oxidase B was immobilised onto magnetic nanoparticles to prepare a new type of affinity solid-phase extraction adsorbent, which was used to extract the possible anti-neurodegenerative components from the Lonicera japonica flower extracts. Coupled with high-performance liquid chromatography with mass spectrometry, two monoamine oxidase B ligands were fished-out and identified as isochlorogenic acid A and isochlorogenic acid C, which were found to be inhibitors of the enzyme for the first time, with similar half maximal inhibitory concentration values of 29.05 ± 0.49 and 29.77 ± 1.03 µM, respectively. Furthermore, equilibrium-dialysis dissociation assay of enzyme-inhibitor complex showed that both compounds have reversible binding patterns to monoamine oxidase B, and kinetic analysis demonstrated that they were mixed-type inhibitors for monoamine oxidase B, with Ki and Kis values of 9.55 and 37.24 µM for isochlorogenic acid A, 9.53 and 35.50 µM for isochlorogenic acid C, respectively. The results indicated that isochlorogenic acid A and isochlorogenic acid C were the major active components responsible for the anti-degenerative activity of the flowers of L. japonica, while magnetic nanoparticles immobilised monoamine oxidase B could serve as an efficient solid-phase extraction adsorbent to specifically extract monoamine oxidase B inhibitors from complex herbal extracts.


Assuntos
Lonicera/química , Nanopartículas de Magnetita/química , Monoaminoxidase/química , Fármacos Neuroprotetores/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Flores/química , Ligantes , Lonicera/metabolismo , Monoaminoxidase/metabolismo , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/metabolismo , Extratos Vegetais/química , Extratos Vegetais/metabolismo , Extração em Fase Sólida
7.
Planta ; 248(4): 769-784, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30066218

RESUMO

MAIN CONCLUSION: This review summarizes current knowledge of chromosome characterization, genetic mapping, genomic sequencing, quality formation, floral transition, propagation, and identification in Dendrobium. The widely distributed Dendrobium has been studied for a long history, due to its important economic values in both medicine and ornamental. In recent years, some species of Dendrobium and other orchids had been reported on genomic sequences, using the next-generation sequencing technology. And the chloroplast genomes of many Dendrobium species were also revealed. The chromosomes of most Dendrobium species belong to mini-chromosomes, and showed 2n = 38. Only a few of genetic studies were reported in Dendrobium. After revealing of genomic sequences, the techniques of transcriptomics, proteomics and metabolomics could be employed on Dendrobium easily. Some other molecular biological techniques, such as gene cloning, gene editing, genetic transformation and molecular marker developing, had also been applied on the basic research of Dendrobium, successively. As medicinal plants, insights into the biosynthesis of some medicinal components were the most important. As ornamental plants, regulation of flower related characteristics was the most important. More, knowledge of growth and development, environmental interaction, evolutionary analysis, breeding of new cultivars, propagation, and identification of species and herbs were also required for commercial usage. All of these studies were improved using genomic sequences and related technologies. To answer some key scientific issues in Dendrobium, quality formation, flowering, self-incompatibility and seed germination would be the focus of future research. And genome related technologies and studies would be helpful.


Assuntos
Dendrobium/genética , Genoma de Planta/genética , Genômica , Mapeamento Cromossômico , Cromossomos de Plantas/genética , Dendrobium/classificação , Dendrobium/fisiologia , Genoma de Cloroplastos/genética , Sequenciamento de Nucleotídeos em Larga Escala , Plantas Medicinais , Reprodução , Análise de Sequência de DNA
8.
J Sep Sci ; 41(19): 3772-3781, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30152917

RESUMO

A microchip capillary electrophoresis coupled with laser induced fluorescence detection method for the fast determination of aloin was developed and comprehensively applied for the quantification of aloin A and B present in seven aloe plant species, 42 aloin-containing crude drugs, ten aloe pharmaceutical preparations, and four aloe gel-containing functional foods. The excitation and emission wavelengths for detection of both aloins were set at 473 and 520 nm, respectively. Sample analysis on a 35 mm length of glass microchip channel was completed within 40 s. An interference study indicated that the other main anthraquinones present in the samples did not interrupt with the target aloins detection, demonstrating the good selectivity of this method. It is demonstrated that this method is fast, facile, and specific for determination of aloin A and B from matrix samples which can be applied to the quality control of a wide varieties of aloe species and aloe-derived products.


Assuntos
Aloe/química , Bebidas/análise , Eletroforese em Microchip , Emodina/análogos & derivados , Fluorescência , Lasers , Emodina/análise , Conformação Molecular , Extratos Vegetais/química , Espectrometria de Fluorescência
9.
Huan Jing Ke Xue ; 38(4): 1327-1339, 2017 Apr 08.
Artigo em Chinês | MEDLINE | ID: mdl-29965133

RESUMO

Fine particles(PM2.5) collected by two middle volume air samplers in the suburbs of Baoding and the urban area of Beijing during Jan 10th to 17th, 2015, were used to compare the community characteristics of cultivable bacteria in the two sites. In this study, we observed the particle morphology of PM2.5 using a field emission scanning electron microscope (FESEM), analyzed the air mass transportation source of the two sampling sites by the NOAA/ARL HYSPLIT-4 backward trajectory model, and measured the concentrations of the major water-soluble ions and heavy metal elements in the PM2.5 samples using ion chromatography, continuous flow analyzer and ICP-MS. The results indicated that, the cultivable bacteria of PM2.5 contained three phyla, which were Firmicutes, Actinobacteria and α-Proteobacteria. Nine genera and 17 species of cultivable airborne bacteria were isolated and identified. The most abundant phylum was Firmicutes. The Gram-positive bacteria accounted for more than 90%. The spore-forming Bacillus which was the dominant species contributed 68.15% and 75% to the total bacteria in urban Beijing and the suburbs of Baoding, respectively. The difference in the community structure of PM2.5's cultivable bacteria in the two sampling areas may be affected by PM2.5's physical and chemical properties and air mass transportation.


Assuntos
Microbiologia do Ar , Poluentes Atmosféricos/análise , Bactérias , Monitoramento Ambiental , Pequim , Tamanho da Partícula , Material Particulado
10.
Zhonghua Nei Ke Za Zhi ; 46(4): 280-3, 2007 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-17637263

RESUMO

OBJECTIVE: In order to take an insight into the profile of HIV/AIDS and tuberculosis (TB) co-infection, we made a statistic survey in 9 hospitals in mainland China. With the purpose of guiding the prevention and treatment, 241 cases with such co-infection were enrolled and the data with respect to clinical manifestations, laboratory tests, therapy and prognosis were analysed. METHODS: All indices were collected with unified questionary. RESULTS: Young men (75.9%) took constituted the majority. HIV was transmitted mainly by intravenous drug use (IDU) in Xinjiang and Yunnan provinces, by blood transfusion or blood products in Shanghai, Henan and Wenxi county of Shanxi, and by sexual transmission in Fuzhou, Shanghai, Shenzhen and Dehong prefecture of Yunnan province. In this survey, pulmonary TB accounted for 59.3%, extra-pulmonary TB for 21.2%, and both for 19.5% of the patients. As for laboratory tests, only 9.5% was positive in sputum for acid-fast bacillus (AFB) and 2.9% in culture, 10.8% of the patients had AFB in pleural fluid or cerebrospinal fluid. Besides, PPD was negative or weakly positive in most of the cases. Overall, 76.8% of the 241 cases had a CD(4) cell count < 200/microl, and 58.5% < 100/microl. 80.5% of the patients was treated with anti-tuberculous medications and 69.7% with highly active antiretroviral therapy (HAART). 203 (84.2%) were still alive and 38 (15.8%) died. CONCLUSIONS: (1) The clinical manifestations of the 241 cases were varied because of prevailing pulmonary TB. (2) The immune function was depressed with reducing CD(4) counts in most of the patients. (3) Positivity rate of examination relevant to TB was too low to help the diagnosis. (4) The mortality (15.8%) was high even with HAART and/or chemotherapy.


Assuntos
Síndrome da Imunodeficiência Adquirida/epidemiologia , Infecções por HIV/epidemiologia , Tuberculose/epidemiologia , Adulto , Antituberculosos/uso terapêutico , Contagem de Linfócito CD4 , China/epidemiologia , Comorbidade , Estudos Transversais , Feminino , Humanos , Masculino , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/isolamento & purificação , Prognóstico , Tuberculose/tratamento farmacológico
11.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 23(4): 466-9, 2006 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-16883544

RESUMO

OBJECTIVE: To understand the genetic polymorphism of DC-SIGN's and DC-SIGNR's neck regions in normal Chinese Han population, and to obtain the genetic data of the two loci in Chinese Han population. METHODS: The genotypes and alleles of repeat sequences of DC-SIGN and DC-SIGNR neck region were typed by PCR, agarose gel electrophoresis and sequencing. Polymorphism information content (PIC) of DC-SIGNR was calculated. RESULTS: DC-SIGN genetic polymorphism was rare. Allele 7 was most and its frequency was 0.9808. 4-, 5-, 6- and 8- alleles were also found, although their frequencies were very low. Caucasians had only 6- and 8- allele mutants; DC-SIGNR genetic polymorphism was high, its PIC was 0.5312, 4-,5-,6-,7-,8-,9- alleles and 16 genotypes were found in normal Chinese Han population. The differences of 6/5,7/4,7/5,7/6,7/7,9/5,9/7,9/9 genotypes distribution and 5-,6-,7-,9- alleles frequency between normal Chinese Han population and Caucasian population were all extremely distinct (P<0.01). The inserted mutation seemed more in Chinese Hans than Caucasian population. CONCLUSION: DC-SIGN and DC-SIGNR genotypes and alleles distribution in Chinese Han population are significantly different from Caucasian population and with Chinese own population genetic characteristics, compared with Caucasians.


Assuntos
Moléculas de Adesão Celular/genética , Lectinas Tipo C/genética , Polimorfismo Genético/genética , Receptores de Superfície Celular/genética , Adolescente , Adulto , Alelos , Povo Asiático/genética , China , Feminino , Frequência do Gene , Genótipo , Humanos , Masculino , Reação em Cadeia da Polimerase , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...