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1.
Talanta ; 235: 122818, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517674

RESUMO

As a type of environmental endocrine disrupting chemicals, bisphenols (BPs) have a certain embryonic toxicity and teratogenicity, which can significantly increase the risks of breast cancer, prostate cancer, leukemia and other cancers. In this work, stable multivariate metal-organic frameworks (UiO-66-NH2/TCPPx) were synthesized via in situ one-pot method and used as miniaturized dispersive solid-phase extraction (dµSPE) sorbents for extraction of trace BPs from environmental samples. The phase purity, crystal morphology and physical properties of UiO-66-NH2/TCPPx samples were varied by adjusting the mass ratio of TCPP. The extraction performance of UiO-66-NH2/TCPPx samples were investigated and UiO-66-NH2/TCPP1.0 exhibited the highest adsorption efficiency. Besides, UiO-66-NH2/TCPP1.0 possessed excellent recycling stability for the adsorption and desorption of BPs more than 20 cycles. The experimental parameters including amount of adsorbent, adsorption time, sample solution pH, temperature, desorption time and desorption solvents which affecting the efficiency of dµSPE were studied, respectively. Good linearity (R2 > 0.9992) in range of 0.1-200 ng mL-1 was obtained. The detection limits (S/N = 3) and quantification limits (S/N = 10) were achieved at 0.03-0.08 ng mL-1 and 0.1-0.5 ng mL-1, respectively. The relative standard deviations (RSDs) of intra-day and inter-day ranged from 2.5 to 5.5% and 1.1-6.8%. Enrichment factors were calculated in the range of 303-338. The obtained recoveries of bisphenol F (BPF), bisphenol A (BPA), bisphenol B (BPB) and bisphenol AF (BPAF) were 81.26-91.03% (RSDs = 0.96-6.47%), 82.2-97.27% (RSDs = 0.45-6.15%), 87.56-97.26% (RSDs = 1.1-6.22%) and 82.2-100.8% (RSDs = 0.46-4.07%). The UiO-66-NH2/TCPP1.0 can be employed as potential dµSPE sorbents for the enrichment of trace BPs in the environmental samples.


Assuntos
Estruturas Metalorgânicas , Adsorção , Compostos Benzidrílicos , Humanos , Masculino , Fenóis , Extração em Fase Sólida , Solventes
2.
Mikrochim Acta ; 188(10): 340, 2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34523015

RESUMO

Using MIL-101(Fe) as the source of carbon and Fe, a magnetic porous carbon (MPC) material with Fe3C nanoparticles encapsulated in porous carbon was prepared through one-pot pyrolysis under N2 atmosphere. With MPC as adsorption material, a stir bar sorptive-dispersive microextraction (SBSDME) method was proposed to extract and preconcentrate sulfonamides (SAs) prior to HPLC-DAD determination. To investigate their extraction ability, different MPC materials were prepared under different carbonization temperatures (600, 700, 800, 900, and 1000 °C). The material prepared under 900 °C (MPC-900) exhibited the highest extraction ability for SAs. The as-prepared MPC materials were also characterized by Raman spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, zeta potential, and other techniques. The main parameters that affect extraction were systematically studied. Under optimal conditions, favorable linearity (R2 ≥ 0.9938) and detection limits (0.02-0.04 ng mL-1) of sulfonamides were obtained. The average recoveries for spiked milk and lake water samples ranged from 76.9 to 109% and from 75.4 to 118% with RSDs of 3.10-9.63% and 1.71-11.3%, respectively. Sulfameter and sulfisoxazole were detected in milk sample. Sulfisoxazole was detected in the lake water sample. The MPC-900 material demonstrated excellent reusability. It can be reused 24 times with peak areas having no obvious decline. The method can be applied to extract ultra-trace compounds in complex sample matrices. Schematic presentation of a stir bar sorptive-dispersive microextraction (SBSDME) by using magnetic porous carbon (MPC) composites as sorbent combined with high-performance liquid chromatography for sensitive analysis of sulfonamides in milk and lake water samples.

3.
Lung ; 199(5): 467-473, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34462814

RESUMO

PURPOSE: Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive fibrotic lung disease of unknown cause with a variable course. Acute exacerbations of IPF (AE-IPF) is sudden accelerations of the disease or a superimposed idiopathic acute injury significantly reducing lung function. To examine the serum concentrations of Progranulin (PGRN) and activin A in patients with AE-IPF in a pilot study. METHODS: Twenty-one patients with AE-IPF were compared with 23 patients with stable IPF as a control group. Serum PGRN and activin A levels, arterial blood gas measurements, and lung function were determined in these two groups. RESULTS: Peripheral blood PGRN and activin A levels in patients with AE-IPF were 83.7 + 10.0 and 14.2 ± 1.7 ng/ml (mean + SD), respectively; higher than those in the control group 61.0 + 5.8 and 5.8 + 1.0 (p < 0.001). PGRN and activin A levels were significantly negatively correlated with carbon monoxide diffusion capacity r = - 0.857 (p < 0.001) and r = - 0.757 (p < 0.001). CONCLUSION: Progranulin (PGRN) and activin A may be involved in the pathogenesis of AE-IPF. They may be possible markers of disease activity in AE-IPF.

4.
Chem Commun (Camb) ; 57(70): 8810-8813, 2021 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-34382969

RESUMO

Herein, a new gas-cycle-assisted (GCA) headspace solid-phase microextraction (HS-SPME) device was designed to rapidly extract organic pollutants with high Kow and boiling points, which have difficulty in volatilization from matrix to headspace. Organic pollutants, including three polycyclic aromatic hydrocarbons (PAHs), four polychlorinated biphenyls (PCBs), and five phthalate esters (PAEs), were selected to evaluate the performance of GCA HS-SPME. Compared with conventional HS-SPME, the equilibrium times of GCA HS-SPME for extraction of PAHs, PCBs, and PAEs were greatly shortened from 70-90 to 5-11 min. Moreover, the limits of detection for analysis of PAHs were achieved at pg mL-1 level by GCA HS-SPME coupled with gas chromatography-flame ionization detection.

5.
Sci Rep ; 11(1): 16614, 2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34400709

RESUMO

We analyze regional factors and spatial distribution of children's vision impairment in Shandong province, to explore the spatial changes brought by time and their influencing factors, so as to provide scientific basis for prevention of childhood vision impairment. This study covers five complete cross-sectional surveys from 2013 to 2017, involving about 29.24 million students. Spatial autocorrelation and hotspot analysis methods were used to analyze spatial features. The associated factors were analyzed by multinomial logistic regression. The vision impairment prevalence showed a trend of decreasing first and then increasing from 2013 to 2017, with slight changes. In terms of regional spatial differences, Weihai and Yantai have the highest VI rates in all years, and there was a large-scale spatial aggregation phenomenon. The southern low-value clusters, however, showed a trend of weakening from year to year. Further exploration revealed that economic factors and number of full-time teachers were verified as risk factors for regional vision impairment levels. The slight rebound of the prevalence of vision impairment and the high rate in the eastern and northern regions of Shandong province need more attention. It is suggested that relevant departments should focus on the influence of regional economic and educational factors when formulating relevant strategies.

6.
Artigo em Inglês | MEDLINE | ID: mdl-34114147

RESUMO

The novel coronavirus disease (COVID-19) broke out worldwide in 2020. The purpose of this paper was to find out the impact of migrant population on the epidemic, aiming to provide data support and suggestions for control measures in various epidemic areas. Generalized additive model was utilized to model the relationship between migrant population and the cumulative number of confirmed cases of COVID-19. The difference of spatial distribution was analyzed through spatial autocorrelation and hot spot analysis. Generalized additive model demonstrated that the cumulative number of confirmed cases was positively correlated with migration index and population density. The predictive results showed that, if no travel restrictions are imposed on the migrant population as usual, this number of COVID-19 would have reached 27,483 (95% CI 16,074, 48,097; the actual number was 23,177). The increase in one city (Jian) would be 577.23% (95% CI 322.73%, 972.73%) compared with the real confirmed cases of COVID-19. The average increase in 73 cities was 85.53% (95% CI 19.53%, 189.81%). Among the migration destinations, the number of cases in cities of Hubei province, Chongqing, and Beijing was relatively high, and there were large-scale high-prevalence clusters in eastern Hubei province. Without restrictions on migration, the high prevalence areas in Hubei province and its surrounding areas will be further expanded. The reduced population mobility and population density can greatly slow down the spread of the epidemic. All epidemic areas should suspend the transportation between cities, strictly control the population travel, and decrease the population density, so as to reduce the spread of COVID-19.

7.
World J Microbiol Biotechnol ; 37(7): 109, 2021 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-34057641

RESUMO

Phosphate solubilizing microorganisms widely exist in plant rhizosphere soil, but report about the P solubilization and multiple growth-promoting properties of rare actinomycetes are scarce. In this paper, a phosphate solubilizing Tsukamurella tyrosinosolvens P9 strain was isolated from the rhizosphere soil of tea plants. Phosphorus-dissolving abilities of this strain were different under different carbon and nitrogen sources, the soluble phosphorus content was 442.41 mg/L with glucose and potassium nitrate as nutrient sources. The secretion of various organic acids, such as lactic acid, maleic acid, oxalic acid, etc., was the main mechanism for P solubilization and pH value in culture was very significant negative correlation with soluble P content. In addition, this strain had multiple growth-promoting characteristics with 37.26 µg/mL of IAA and 72.01% of siderophore relative content. Under pot experiments, P9 strain improved obviously the growth of peanut seedlings. The bacterial communities of peanut rhizoshpere soil were assessed after inoculated with P9 strain. It showed that there was no significant difference in alpha-diversity indices between the inoculation and control groups, but the P9 treatment group changed the composition of bacterial communities, which increased the relative abundance of beneficial and functional microbes, which relative abundances of Chitinophagaceae at the family level, and of Flavihumibacter, Ramlibacter and Microvirga at the genus level, were all siginificant increased. Specially, Tsukamurella tyrosinosolvens were only detected in the rhizosphere of the inoculated group. This study not only founded growth-promoting properties of T. tyrosinosolvens P9 strain and its possible phosphate solublizing mechanism, but also expected to afford an excellent strain resource in biological fertilizers.

8.
Arch Microbiol ; 203(5): 2279-2290, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33644819

RESUMO

Plant growth-promoting rhizobacteria that produce 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase can promote plant growth and enhance abiotic stress tolerance. In this study, Burkholderia pyrrocinia strain P10, with an ACC deaminase activity of 33.01-µmol/h/mg protein, was isolated from the tea rhizosphere and identified based on morphological, biochemical, and molecular characteristics. In addition to its ACC deaminase activity at pH 5.0-9.0 and in response to 5% NaCl and 20% polyethylene glycol, strain P10 can also solubilize phosphorus compounds, produce indole-3-acetic acid, and secrete siderophores. Pot experiments revealed that strain P10 can significantly enhance peanut seedling growth under saline conditions (100- and 170-mmol/L NaCl). Specifically, it increased the fresh weight and root length of plants by 90.12% and 79.22%, respectively, compared with high-salt stress. These results provide new insights into the biological characteristics of Burkholderia pyrrocinia, which may be useful as a bio-fertilizer.


Assuntos
Burkholderia/enzimologia , Burkholderia/metabolismo , Carbono-Carbono Liases/metabolismo , Raízes de Plantas/microbiologia , Chá/microbiologia , Aminoácidos Cíclicos/metabolismo , Burkholderia/isolamento & purificação , Ácidos Indolacéticos/metabolismo , Desenvolvimento Vegetal , Rizosfera , Plantas Tolerantes a Sal/metabolismo , Plântula/microbiologia , Sideróforos/metabolismo
9.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 28(6): 2039-2045, 2020 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-33283739

RESUMO

OBJECTIVE: To compare the effect of Sheng-Xue-Xiao-Ban Capsule (SXXBC) and indirubin to the peripheral platelets of the Idiopathic thrombocytopenic purpura (ITP) model mouse. METHODS: The ITP mouse model was established by the method of passive immunization. SXXBC and indirubin were used for intervention treatment. Then the hemorrhagic phenomena of ITP mice were observed and the numbers of peripheral platelets, hemoglobin and white blood cells, bone marrow megakaryocytes and their classification and coagulation function were detected and compared. RESULTS: The improvement rate of hemorrhage in SXXBC group was 40% for small dose, 60% for medium dose and 80% for high dose, while the improvement rate of hemorrhage in indirubin group was 30% for small dose, 50% for medium dose and 60% for high dose. There was no statistically significant difference in the improvement rate of hemorrhage between the two groups (P>0.05). Compared with the model control group, PLT and Hb increased in different doses of SXXBC and indirubin group 4th-8th day after drug intervention (P<0.05, 0.01). However, there was no significant difference between the different doses of SXXBC group and indirubin group (P>0.05). Compared with the model control group, the WBC in each group was significantly lower (P<0.05, 0.01) on the 4th-8th day after drug intervention; However, there was no statistical significance between the two groups of SXXBC and indirubin (P>0.05). Compared with the model control group, the total number of megakaryocytes in each treatment group were decreased (P<0.05, P<0.01), in which the number of primary megakaryocytes in the large and medium dose groups of SXXBC and indirubin were decreased (P<0.05, 0.01), and the number of juvenile megakaryocytes in the large dose group of SXXBC and indirubin were also decreased (P<0.05). The number of granular megakaryocytes were decreased in each intervention groups (P<0.05, 0.01), and the number of thromocytogenic megakaryocyte was increased in the high and medium dose groups of SXXBC and indirubin (P<0.01). The time of prothrombin was shortened in the high and medium dose groups of SXXBC and indirubin (P<0.05), and the fibrinogen (FIB) content in the high and medium dose groups of SXXBC was close to that of the normal control group. CONCLUSION: Both of the SXXBC and the indirubin standard all show good hemostatic effects. Indirubin shows a positive effect on increasing the peripheral platelet and hemoglobin in ITP model mice, regulating the immune response, reducing the total number of bone marrow megakaryocytes, increasing the thromocytogenic megakaryocyte, and increasing coagulation function.


Assuntos
Púrpura Trombocitopênica Idiopática , Animais , Plaquetas , Cápsulas , Indóis , Megacariócitos , Camundongos , Púrpura Trombocitopênica Idiopática/tratamento farmacológico
10.
J Chromatogr A ; 1626: 461354, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797834

RESUMO

The Al-doped mesoporous crystalline material-41 (Al-MCM-41) composite was prepared and applied as fiber coating material of headspace solid-phase microextraction (HS-SPME) for extraction of polycyclic aromatic hydrocarbons (PAHs) from human urine. Five PAHs including acenaphthene, fluorene, phenanthrene, anthracene, and pyrene are chosen as target analytes to evaluate the performance of the material by GC-FID analysis. The mesoporous Al-MCM-41 composite was characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption/desorption measurement, and thermogravimetric analysis. The parameters affecting the extraction efficiency of HS-SPME were investigated. Under the optimal conditions, the method exhibits ideal linearity for target analytes in the range of 0.3-600 ng⋅mL-1 with the coefficients (R2) equal or higher than 0.9906. The enrichment factors are calculated from 540 to 1760. The limits of detection (LODs) and limits of quantitation (LOQs) are between the ranges of 0.06-0.18 and 0.3-0.9 ng⋅mL-1, respectively. The relative standard deviations (RSDs) (n = 5) of intra-day and inter-day are in the ranges of 1.08-7.49% and 2.84-18.3% respectively. The fiber-to-fiber reproducibility (n = 3) is in the range of 6.47-13.9%. The method was successfully applied for the analysis of PAHs in human urine with reasonable recoveries which is ranging from 73.29 to 116.1%.


Assuntos
Alumínio/química , Hidrocarbonetos Policíclicos Aromáticos/urina , Dióxido de Silício/química , Microextração em Fase Sólida/métodos , Adsorção , Cristalização , Humanos , Limite de Detecção , Masculino , Concentração Osmolar , Porosidade , Padrões de Referência , Reprodutibilidade dos Testes , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Fatores de Tempo , Difração de Raios X
11.
Mikrochim Acta ; 187(6): 367, 2020 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-32494885

RESUMO

The monodispersed mesoporous SiO2@metal-organic framework (MSN@MIL-101(Fe)) composites were prepared by grafting MSN-NH2 onto MIL-101(Fe) particles with a solvothermal method. The adsorption ability of the composites was greatly improved compared to that of pristine MSNs or MIL-101(Fe) for phytohormones (Phys). The MSN@MIL-101(Fe) composites were characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, energy dispersive spectrometer, and mapping analysis. Using MSN@MIL-101(Fe) composites as sorbent, a dispersive solid-phase extraction procedure (dSPE) was developed to extract three endogenous Phys (abscisic acid (ABA), indole-3-aceticacid (IAA), and indole-3-butyric acid (IBA)) and two exogenous Phys (1-naphthylacetic acid (1-NAA) and 2-naphthylacetic acid (2-NAA)) prior to HPLC-DAD analysis. The experimental parameters including sample volume, sorbent amount, adsorption time, adsorption pH, desorption time, and desorption solvent on extraction efficiency were optimized and evaluated. Under optimized conditions, the working range of 0.08 to 0.45 ng mL-1 with enrichment factors from 144 to 207 were achieved. The linear range is 0.75-200 ng mL-1 for IAA, 0.20-200 ng mL-1 for ABA, and 1.0-200 ng mL-1 for IBA, 1-NAA, and 2-NAA. With MSN@MIL-101(Fe) as sorbent for extraction of Phys and determination by HPLC-DAD, two endogenous Phys (IAA and ABA) were detected from mung bean sprouts which were made in a laboratory, and the results were further confirmed by high-resolution mass spectrometry. The composites can be applied to extract other small molecules, which have similar chemical structures with Phys in biological, environmental, and food samples. Graphical abstract Schematic presentation of a dispersive solid-phase extraction using monodispersed mesoporous SiO2@metal-organic framework composites (MSNs@MIL-101(Fe)) as the sorbent for extraction, clean-up, and preconcentration of phytohormones in mung bean sprouts prior to HPLC-DAD analysis.

12.
Prep Biochem Biotechnol ; 50(5): 486-493, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31900038

RESUMO

Catechol 1,2-dioxygenases catalyze catechol ring-opening, a critical step in the degradation of aromatic compounds. Cupriavidus campinensis BJ71, an efficient 2,4-dichlorophenoxyacetic acid (2,4-D)-degrading bacterial strain, was previously isolated from an environment contaminated with 2,4-D. In this study, catA encoding a catechol 1,2-dioxygenase was cloned from the BJ71 strain. The gene was 939 bp long and encoded a polypeptide of 312 amino acids with a molecular weight of 34 kDa. To investigate its enzymatic characteristics, CatA was heterologously expressed in Escherichia coli. Optimal reaction conditions for the pure enzyme were 35 °C and pH 8.0. The enzyme remained stable within a range of 25 °C-45 °C and pH 6.0-9.0, thus indicating that CatA has wide temperature and pH adaptability. After incubation at 45 °C, the enzyme activity of CatA decreased to 37.12%, but its activity was not affected by incubation at pH 9.0. The pure enzyme was able to use catechol, 4-methyl-catechol and 4-chlorocatechol as substrates. Enzyme kinetic parameters Km and Vmax were 39.97 µM and 10.68 U/mg, respectively. This is the first report of the cloning of a gene encoding a catechol 1,2-dioxygenase from a 2,4-D-degrading bacterial strain.


Assuntos
Proteínas de Bactérias/química , Catecol 1,2-Dioxigenase/química , Cupriavidus/enzimologia , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Proteínas de Bactérias/isolamento & purificação , Catecol 1,2-Dioxigenase/genética , Catecol 1,2-Dioxigenase/isolamento & purificação , Clonagem Molecular , Ensaios Enzimáticos , Escherichia coli/genética , Concentração de Íons de Hidrogênio , Filogenia , Alinhamento de Sequência , Temperatura
13.
J Surg Res ; 202(2): 398-402, 2016 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-27229115

RESUMO

BACKGROUND: The aim of the study was to evaluate the clinical utility of the colon leakage score (CLS) in predicting the risk of anastomotic leakage (AL) after left-sided colorectal surgery. MATERIALS AND METHODS: This investigation was designed as a retrospective study of 304 patients who underwent left-sided colorectal surgery. The patients were classified into two groups as those who developed AL and those who did not develop AL, and the CLSs of the two groups were compared. The predictive value and the cutoff value of the CLS were assessed by receiver operating characteristic and logistic regression analysis. RESULTS: A significant difference was noted in the mean CLSs of the groups with and without AL (P < 0.001). The values of the area under the receiver operating characteristic curve (0.965; confidence interval, 0.913-1.00) and the odds ratio (2.9; confidence interval, 1.59-4.83; P < 0.001) indicated that CLS was a good predictor of AL. A CLS of 11 was found to be the best cutoff value, with a sensitivity and specificity of 84.6% and 87.2%, respectively. CONCLUSIONS: Our findings indicate that CLS can effectively predict the risk of AL after left-sided colorectal surgery and that a CLS of 11 can be used as a cutoff value for the risk level.


Assuntos
Fístula Anastomótica/diagnóstico , Colectomia , Colo/cirurgia , Técnicas de Apoio para a Decisão , Reto/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Fístula Anastomótica/etiologia , Fístula Anastomótica/prevenção & controle , Estudos de Casos e Controles , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Curva ROC , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Sensibilidade e Especificidade
14.
Braz J Microbiol ; 46(2): 433-41, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26273258

RESUMO

An indigenous bacterial strain capable of utilizing 2,4-dichlorophenoxyacetic acid as the sole carbon and energy source was isolated from a soil used for grown wheat with a long-term history of herbicide use in Beijing, China. The strain BJ71 was identified as Cupriavidus campinensis based on its 16S rRNA sequence analysis and morphological, physiological, and biochemical characteristics. The degradation characteristics of strain BJ71 were evaluated. The optimal conditions for 2,4-D degradation were as follows: pH 7.0, 30 °C, 3% (v/v) inoculum size, and an initial 2,4-D concentration of 350 mg L(-1). Up to 99.57% of the 2,4-D was degraded under optimal conditions after 6 days of incubation. Strain BJ71 was also able to degrade quizalofop and fluroxypyr. This is the first report of a 2,4-D-degrader containing tfdA gene that can utilize these two herbicides. In a biodegradation experiment, 87.13% and 42.53% of 2,4-D (initial concentration, 350 mg kg(-1)) was degraded in non-sterile and sterilized soil inoculated with BJ71, respectively, after 14 days. The 2,4-D degradation was more rapid in a soil microcosm including BJ71 than in a soil microcosm without BJ71. These results indicate that strain BJ71 is a potential candidate for the bioremediation of soil contaminated with the herbicide 2,4-D.


Assuntos
Ácido 2,4-Diclorofenoxiacético/metabolismo , Cupriavidus/isolamento & purificação , Cupriavidus/metabolismo , Herbicidas/metabolismo , Acetatos/metabolismo , Técnicas Bacteriológicas , Biotransformação , China , Análise por Conglomerados , Cupriavidus/genética , Cupriavidus/fisiologia , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Varredura , Dados de Sequência Molecular , Filogenia , Propionatos/metabolismo , Piridinas/metabolismo , Quinoxalinas/metabolismo , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Temperatura , Fatores de Tempo , Triticum
15.
Braz. j. microbiol ; 46(2): 433-441, Apr-Jun/2015. graf
Artigo em Inglês | LILACS | ID: lil-749723

RESUMO

An indigenous bacterial strain capable of utilizing 2,4-dichlorophenoxyacetic acid as the sole carbon and energy source was isolated from a soil used for grown wheat with a long-term history of herbicide use in Beijing, China. The strain BJ71 was identified as Cupriavidus campinensis based on its 16S rRNA sequence analysis and morphological, physiological, and biochemical characteristics. The degradation characteristics of strain BJ71 were evaluated. The optimal conditions for 2,4-D degradation were as follows: pH 7.0, 30 °C, 3% (v/v) inoculum size, and an initial 2,4-D concentration of 350 mg L−1. Up to 99.57% of the 2,4-D was degraded under optimal conditions after 6 days of incubation. Strain BJ71 was also able to degrade quizalofop and fluroxypyr. This is the first report of a 2,4-D-degrader containing tfdA gene that can utilize these two herbicides. In a biodegradation experiment, 87.13% and 42.53% of 2,4-D (initial concentration, 350 mg kg−1) was degraded in non-sterile and sterilized soil inoculated with BJ71, respectively, after 14 days. The 2,4-D degradation was more rapid in a soil microcosm including BJ71 than in a soil microcosm without BJ71. These results indicate that strain BJ71 is a potential candidate for the bioremediation of soil contaminated with the herbicide 2,4-D.


Assuntos
Cupriavidus/isolamento & purificação , Cupriavidus/metabolismo , Herbicidas/metabolismo , /metabolismo , Acetatos/metabolismo , Técnicas Bacteriológicas , Biotransformação , China , Análise por Conglomerados , Cupriavidus/genética , Cupriavidus/fisiologia , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Varredura , Dados de Sequência Molecular , Filogenia , Propionatos/metabolismo , Piridinas/metabolismo , Quinoxalinas/metabolismo , /genética , Análise de Sequência de DNA , Temperatura , Fatores de Tempo , Triticum
16.
World J Microbiol Biotechnol ; 31(7): 1021-30, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25850533

RESUMO

2,4-Dichlorophenoxyacetic acid (2,4-D)/α-ketoglutarate (α-KG) dioxygenase (TfdA) is an Fe(II)-dependent enzyme that catalyzes the first step in degradation of the herbicide 2,4-D. Previous studies focused on the tfdA gene in Ralstonia eutropha JMP134 isolated in Australia. In this study, a new tfdA gene was cloned from Cupriavidus campinensis BJ71, an effective degrading bacteria from China, based on the iCOnsensus-DEgenerate Hybrid Oligonucleotide Primers (iCODEHOPs) protocol, combined with high-efficiency Thermal Asymmetric Interlaced PCR (hiTAIL-PCR). The open reading frame of 861 bp encoded a putative 287 amino acid protein with a theoretical molecular mass of 32.32 kDa. The gene was overexpressed in Escherichia coli BL21 (DE3) and the purified TfdA showed optimal activity at pH 6.75 and 30 °C. This enzyme was more thermostable and it could use 3-hydrocinnamic acid as substrate, with a similar enzyme activity compared with 2,4-D. TfdA and its variants were created as maltose-binding protein (MBP) tagged fusion proteins to examine the roles of putative substrate-binding residues. The MBP-N110A, MBP-V198A and MBP-R207K proteins showed decreased k cat and increased Km, and MBP-R278A was inactive, suggesting these residues may affect 2,4-D binding or catalysis.


Assuntos
Clonagem Molecular/métodos , Cupriavidus/enzimologia , Oxigenases de Função Mista/química , Oxigenases de Função Mista/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Sítios de Ligação , Cupriavidus/genética , Estabilidade Enzimática , Oxigenases de Função Mista/metabolismo , Mutagênese Sítio-Dirigida , Fases de Leitura Aberta , Fenilpropionatos/metabolismo , Temperatura
17.
Genomics Proteomics Bioinformatics ; 12(5): 210-20, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25462153

RESUMO

Genetic studies are traditionally based on single-gene analysis. The use of these analyses can pose tremendous challenges for elucidating complicated genetic interplays involved in complex human diseases. Modern pathway-based analysis provides a technique, which allows a comprehensive understanding of the molecular mechanisms underlying complex diseases. Extensive studies utilizing the methods and applications for pathway-based analysis have significantly advanced our capacity to explore large-scale omics data, which has rapidly accumulated in biomedical fields. This article is a comprehensive review of the pathway-based analysis methods-the powerful methods with the potential to uncover the biological depths of the complex diseases. The general concepts and procedures for the pathway-based analysis methods are introduced and then, a comprehensive review of the major approaches for this analysis is presented. In addition, a list of available pathway-based analysis software and databases is provided. Finally, future directions and challenges for the methodological development and applications of pathway-based analysis techniques are discussed. This review will provide a useful guide to dissect complex diseases.


Assuntos
Bases de Dados Factuais , Doença/genética , Redes Reguladoras de Genes , Transdução de Sinais , Humanos , Software
18.
World J Microbiol Biotechnol ; 30(10): 2567-76, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24898178

RESUMO

Twenty-two 2,4-dichlorophenoxyacetic acid (2,4-D)-degrading bacterial isolates were collected from agricultural soils at three sites in China. Sequence analysis of the 16S rRNA genes indicated that the isolates were phylogenetically grouped into four categories: Ochrobactrum anthropi, in the Alpha- class of the phylum Proteobacteria (3 out of 22 isolates), Cupriavidus sp., of the Betaproteobacteria (3 out of 22), Pseudomonas sp. and Stenotrophomonas sp., which are Gammaproteobacteria (7 out of 22), and Bacillus sp., of the phylum Firmicutes (9 out of 22). Primers were designed to amplify the conserved domain of tfdA, which is known to be involved in the degradation of 2,4-D. Results showed that the tfdA genes of all 22 strains were most similar to that of Cupriavidus necator JMP134, which belongs to the 2,4-D/α-ketoglutarate dioxygenase TfdA protein family, indicating that the JMP134-type tfdA gene is likely to be almost universal among the 2,4-D-degrading bacteria isolated from China. Degradation abilities of these 22 strains were investigated in assays using 2,4-D as the sole source of carbon and energy. Thirteen strains degraded >60 % of the available 2,4-D (500 mg l(-1)) over a 1-week incubation period, while a further nine Bacillus sp. strains degraded 50-81 % of the available 2,4-D. None of these nine strains degraded other selected herbicides, such as mecoprop, 2-methyl-4-chlorophenoxyacetic acid, quizalofop, and fluroxypyr. This is the first report of 2,4-D-degradation by Bacilli.


Assuntos
Ácido 2,4-Diclorofenoxiacético/metabolismo , Bactérias/isolamento & purificação , Proteínas de Bactérias/genética , RNA Ribossômico 16S/análise , Bactérias/classificação , Bactérias/genética , China , Evolução Molecular , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNA
19.
Acta Biochim Biophys Sin (Shanghai) ; 40(8): 711-20, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18685787

RESUMO

A combination of extrinsic hematopoietic growth regulators, such as stem cell factor (SCF), interleukin (IL)-3 and IL-6, can induce division of quiescent hematopoietic stem cells (HSCs), but it usually impairs HSCs' self-renewal ability. However, intrinsic negative cell cycle regulators, such as p18INK4C (p18), p27Kip1 (p27) and MAD1, can regulate the self-renewal of HSCs. It is unknown whether the removal of some extrinsic regulators and the knockdown of intrinsic negative cell cycle regulators via RNA interference (RNAi) induce ex vivo expansion of the HSCs. To address this question, a lentiviral vector-based RNAi tool was developed to produce two copies of small RNA that target multiple genes to knockdown the intrinsic negative cell cycle regulators p18, p27 and MAD1. Colony-forming cells, long-term culture-initiating cells (LTC-IC) and engraftment assays were used to evaluate the effects of extrinsic and intrinsic regulators. Results showed that the medium with only SCF, but without IL-3 and IL-6, could maintain the sca-1+c-kit+ bone marrow cells with high LTC-IC frequency and low cell division. However, when the sca-1+c-kit+ bone marrow cells were cultured in a medium with only SCF and simultaneously knocked down the expression of p18, p27 and MAD1 via the lentiviral vector-based RNAi, the cells exhibited both high LTC-IC frequency and high cell division, though engraftment failed. Thus, the simultaneous knockdown of p18, p27 and MAD1 with a medium of only SCF can induce LTC-IC expansion despite the loss of engraftment ability.


Assuntos
Células da Medula Óssea/citologia , Células da Medula Óssea/metabolismo , Proteínas de Ciclo Celular/antagonistas & inibidores , Inibidor de Quinase Dependente de Ciclina p18/antagonistas & inibidores , Inibidor de Quinase Dependente de Ciclina p27/antagonistas & inibidores , Proteínas Nucleares/antagonistas & inibidores , Animais , Sequência de Bases , Células da Medula Óssea/efeitos dos fármacos , Transplante de Medula Óssea , Ciclo Celular/genética , Proteínas de Ciclo Celular/genética , Células Cultivadas , Ensaio de Unidades Formadoras de Colônias , Inibidor de Quinase Dependente de Ciclina p18/deficiência , Inibidor de Quinase Dependente de Ciclina p18/genética , Inibidor de Quinase Dependente de Ciclina p27/deficiência , Inibidor de Quinase Dependente de Ciclina p27/genética , DNA Complementar/genética , Feminino , Vetores Genéticos , Hematopoese/genética , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Células-Tronco Hematopoéticas/metabolismo , Lentivirus/genética , Camundongos , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Proteínas Nucleares/deficiência , Proteínas Nucleares/genética , Interferência de RNA , RNA Interferente Pequeno/genética , Fator de Células-Tronco/farmacologia
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