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1.
Huan Jing Ke Xue ; 40(8): 3753-3763, 2019 Aug 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854785

RESUMO

A total of 351 surface soil samples (0-20 cm) were collected from the Luanhe River Basin in Chengde City (a typical area of concentrated mineral resources) and analyzed for 12 heavy metals (Cu, Ni, Cd, Cr, Pb, Zn, Hg, V, Ti, Mn, As, and Co). The geochemical baseline values of the heavy metals were determined using the reference element method and the cumulative frequency curve method. Furthermore, the spatial structure and distribution characteristics of the heavy metals were assessed based on PCA and geostatistical analysis. The accumulation of heavy metal pollution in different types of soil and in association with different land use patterns was also evaluated using a geological accumulative index. The results showed that the geochemical baseline values of V, Ti, Cd, Pb, Mn, and Co in the surface soils of the Luanhe River Basin were higher than their background values for Hebei Province. In contrast, the geochemical baseline values of As, Zn, Cr, Cu, Ni, and Hg were lower than their background values. The average accumulation index of the surface soils followed the order of Cd > Pb > Cu > Ti > Mn > Zn > Cr > Ni > Co > V > Hg > As. More than 80% of the soil samples were categorized as having no accumulation or moderate accumulation of Pb, Ti, V, As, and Co, while over 70% of the soil samples were categorized as having no accumulation or moderate accumulation of Hg, Mn, Ni, Cu, As, Cd, and Cr. With respect to different soil types, the average accumulation index of heavy metals followed the order of fluvo-aquic soil>cinnamon soil>brown soil. With respect to land use types, the accumulation index of heavy metals followed the order of industrial and mining land > shrub forest land > agricultural land > woodland and grassland. The accumulation of Pb and Cd in the surface soils of agricultural land was relatively high in comparison to the other elements, with 27.69% and 25.38% of the samples being above the moderate accumulation level, respectively. The iron group elements Ti, V, Co, Ni, and Cr are likely to derive from naturally high geological background sources, while the spatial patterns of Cd, Pb, Zn, Mn, Cu, and As were associated with the combination of parent material and anthropogenic inputs. The accumulation of Hg was mainly influenced by human activities.

2.
J Org Chem ; 84(17): 10615-10628, 2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31379168

RESUMO

Copper(I)-catalyzed stereodivergent nucleophilic propargylation at the anomeric carbon of unprotected N-acetyl mannosamine was developed using 3-substituted allenylboronates as a nucleophile. The homopropargylic alcohol products contained two contiguous stereocenters, and two stereoisomers out of the four possible isomers were selectively obtained in a catalyst-controlled manner by applying either basic conditions: a MesCu/(R,R,R)-Ph-SKP catalyst with a B(OiPr)3 additive or acidic conditions: a CuBF4/(S,S,S)-Ph-SKP catalyst with an MeB(OiPr)2 additive. Mechanistic studies suggested the presence of distinct active nucleophilic species depending on the conditions: an allenylcopper species under the basic conditions or an allenylboronate activated by the Lewis acidic copper catalyst under the acidic conditions. The propargylation products were concisely transformed into C3-substituted sialic acids in two steps without the use of protecting groups.

3.
Brain ; 142(8): 2215-2229, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31199454

RESUMO

Charcot-Marie-Tooth disease is a hereditary motor and sensory neuropathy exhibiting great clinical and genetic heterogeneity. Here, the identification of two heterozygous missense mutations in the C1orf194 gene at 1p21.2-p13.2 with Charcot-Marie-Tooth disease are reported. Specifically, the p.I122N mutation was the cause of an intermediate form of Charcot-Marie-Tooth disease, and the p.K28I missense mutation predominately led to the demyelinating form. Functional studies demonstrated that the p.K28I variant significantly reduced expression of the protein, but the p.I122N variant increased. In addition, the p.I122N mutant protein exhibited the aggregation in neuroblastoma cell lines and the patient's peroneal nerve. Either gain-of-function or partial loss-of-function mutations to C1ORF194 can specify different causal mechanisms responsible for Charcot-Marie-Tooth disease with a wide range of clinical severity. Moreover, a knock-in mouse model confirmed that the C1orf194 missense mutation p.I121N led to impairments in motor and neuromuscular functions, and aberrant myelination and axonal phenotypes. The loss of normal C1ORF194 protein altered intracellular Ca2+ homeostasis and upregulated Ca2+ handling regulatory proteins. These findings describe a novel protein with vital functions in peripheral nervous systems and broaden the causes of Charcot-Marie-Tooth disease, which open new avenues for the diagnosis and treatment of related neuropathies.

4.
J Am Chem Soc ; 139(13): 4647-4650, 2017 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-28318257

RESUMO

A copper(I)-catalyzed enantioselective addition of enynes to ketones was developed. The method allows facile construction of enantiomerically enriched tertiary alcohols using skipped enynes as stable hydrocarbon pronucleophiles. The combination of a soft copper(I)-conjugated Brønsted base catalyst with a chiral diphosphine ligand, (S,S)-Ph-BPE, enabled chemoselective deprotonation of the skipped enynes in the presence of ketones bearing intrinsically more acidic α-protons. The catalytically generated chiral allylcopper species enantio-, diastereo-, regio-, and chemoselectively reacted with ketones, thereby demonstrating excellent substrate generality with functional group tolerance. The skipped enyne moieties of the pronucleophiles were exclusively converted to cis-conjugated enynes, which will eventually allow for further versatile transformations.

5.
ACS Cent Sci ; 2(1): 21-6, 2016 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-27163022

RESUMO

We developed a copper(I)-catalyzed stereodivergent anomeric propargylation of unprotected aldoses as a facile synthetic pathway to a broad variety of sialic acid derivatives. The soft allenylcopper(I) species, catalytically generated from stable allenylboronic acid pinacolate (2), is unusually inert to protonolysis by the multiple hydroxy groups of the substrates and thereby functions as a carbon nucleophile. The key additive B(OMe)3 facilitated ring-opening of the nonelectrophilic cyclic hemiacetal forms of aldoses to the reactive aldehyde forms. The chirality of the catalyst, and not the internal stereogenic centers of substrates, predominantly controlled the stereochemistry of the propargylation step; i.e., the diastereoselectivity was switched simply by changing the catalyst chirality. This is the first nonenzyme catalyst-controlled stereodivergent C-C bond elongation at the anomeric center of unprotected aldoses, which contain multiple protic functional groups and stereogenic centers. The propargylation products can be expeditiously transformed into naturally occurring and synthetic sialic acid derivatives in a simple three-step sequence. This synthetic method, which requires no protecting groups, can be performed on a gram-scale and thus offers general and practical access to various sialic acid derivatives from unprotected aldoses.

6.
Guang Pu Xue Yu Guang Pu Fen Xi ; 36(9): 3062-7, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30085614

RESUMO

La-Co-O mixed oxides (LCO) were prepared by co-precipitation method with the presence of polyethylene glycol (PEG) as dispersant. The influence of adding different molecular weight of PEG (0, 2 000, 6 000, 20 000 g·mol-1) on the physicochemical and catalytic properties of La-Co-O mixed oxides for total oxidation of benzene was investigated. The samples were characterized by means of N2 physical adsorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), temperature-programmed reduction by H2 (H2-TPR), temperature-programmed desorption of O2 (O2-TPD), and X-ray photoelectron spectroscopy (XPS). The order of catalytic activity was found to be LCO-PEG6000>LCO>LCO-PG20000>LCO-PG2000. Particularly, LCO-PEG6000 exhibited benzene conversion of 99% at temperature as low as 383 ℃, which was 126 ℃ lower than that of LCO. The characterization result reveals that all samples had a BET surface area of about 9~10 m2·g-1. The XRD result shows that on all samples LaCoO3 perovskite was mainly formed together with a small amount of La2O3 and Co3O4. The addition of PEG was favorable for the formation of LaCoO3 perovskite. Particularly, the addition of PEG-6000 effectively suppressed the agglomeration of LaCoO3 perovskite, giving rise to small and uniform particles as observed by SEM. Moreover, the results of H2-TPR and O2-TPD indicate that the obtained La-Co-O mixed oxides showed higher reducibility and lattice oxygen mobility, and the Co 2p XPS analysis suggests that more surface Co3+ active species were presented by the addition of PEG-6000. These properties are thought to contribute to the high activity in benzene total oxidation.

7.
Blood Cells Mol Dis ; 53(4): 241-5, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24958328

RESUMO

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked incompletely dominant enzyme deficiency that results from G6PD gene mutations. Women heterozygous for G6PD mutations exhibit variation in the loss of enzyme activity but the cause of this phenotypic variation is unclear. We determined DNA methylation and X-inactivation patterns in 71 G6PD-deficient female heterozygotes and 68 G6PD non-deficient controls with the same missense mutations (G6PD Canton c.1376G>T or Kaiping c.1388G>A) to correlate determinants with variable phenotypes. Specific CpG methylations within the G6PD promoter were significantly higher in G6PD-deficient heterozygotes than in controls. Preferential X-inactivation of the G6PD wild-type allele was determined in heterozygotes. The incidence of preferential X-inactivation was 86.2% in the deficient heterozygote group and 31.7% in the non-deficient heterozygote group. A significant negative correlation was observed between X-inactivation ratios of the wild-type allele and G6PD/6-phosphogluconate dehydrogenase (6PGD) ratios in heterozygous G6PD Canton (r=-0.657, p<0.001) or Kaiping (r=-0.668, p<0.001). Multivariate logistic regression indicated that heterozygotes with hypermethylation of specific CpG sites in the G6PD promoter and preferential X-inactivation of the wild-type allele were at risk of enzyme deficiency.


Assuntos
Metilação de DNA , Variação Genética , Deficiência de Glucosefosfato Desidrogenase/genética , Glucosefosfato Desidrogenase/genética , Mutação de Sentido Incorreto , Inativação do Cromossomo X , Adulto , Sequência de Bases , Ilhas de CpG , Feminino , Genótipo , Deficiência de Glucosefosfato Desidrogenase/patologia , Heterozigoto , Humanos , Modelos Logísticos , Anotação de Sequência Molecular , Fenótipo , Fosfogluconato Desidrogenase/genética , Regiões Promotoras Genéticas , Fatores de Risco
8.
Blood Cells Mol Dis ; 51(1): 31-4, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23481460

RESUMO

Genetic recombination has been implicated as a mechanism that drives mutagenesis in the human globin gene clusters, either as a result of unequal crossover or gene conversion. In this paper, a novel fusion gene was identified in a Chinese girl with hemoglobin H disease. The proband's father was a compound heterozygote for the common -α(4.2) deletion and this fusion gene, and her mother was heterozygous for the common --(SEA) deletion (--(SEA)/αα). Both her parents had a hypochromic and microcytic red cell phenotype and a normal hemoglobin level. Molecular studies revealed a compound heterozygote for the --(SEA) deletion and this novel fusion gene and the patient had the clinical features of classic hemoglobin H disease. Sequence analysis revealed that the mutant gene was the result of a fusion between the α2 and ψα1 genes. The recombination began at exon 3 of α2 gene, crossing with exon 3 of the ψα1 gene. With this recombination, the conservative 3'UTR of the α2 gene was changed, and an extensive transcript with a new signal 1048bp 3' to the terminating codon was found. The abnormal transcripts of the fusion gene read through the intergenic sequence.


Assuntos
Deleção de Genes , Fusão Gênica , Hemoglobina H/genética , alfa-Globinas/genética , Talassemia alfa/genética , Sequência de Bases , Pré-Escolar , Feminino , Heterozigoto , Humanos , Linhagem , Transcrição Genética , Talassemia alfa/diagnóstico
9.
J Am Chem Soc ; 134(41): 17019-22, 2012 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-23039221

RESUMO

A general catalytic enantioselective method that can produce five-, six-, and seven-membered N-heterocycles possessing various ketone moieties starting from stable and easily available cyclic hemiaminals and ketones was developed. The method involves three successive steps in one pot (aldol addition, dehydration, and enantioselective intramolecular aza-Michael reaction), all of which are promoted by a chiral copper(I)-conjugated Brønsted base catalyst. This method is useful for rapid access to versatile chiral building blocks for the synthesis of drug-lead alkaloids.


Assuntos
Alcaloides/síntese química , Cobre/química , Compostos Heterocíclicos/química , Cetonas/química , Nitrogênio/química , Compostos Organometálicos/química , Alcaloides/química , Catálise , Estrutura Molecular , Estereoisomerismo
10.
Zhonghua Xue Ye Xue Za Zhi ; 33(10): 856-60, 2012 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-23384911

RESUMO

OBJECTIVE: To investigate the hematological characteristics of co-inheritance of α-thalassemia (α-thal) and ß-thalassemia (ß-thal) and to survey the incidence of co-inheritance of α-thal and ß-thal in Guangxi. METHODS: DNA samples from 370 primary and middle school students who were ß-thal carriers in Guangxi were further processed for the α-goblin gene mutation screening, and were grouped based on the genotype of ß- and α-goblin gene. The hematological indexes to the different groups were compared by One-way ANOVA. RESULTS: Of the total 370 ß-thal carriers, 79 were found to carry α-thal, which gave a frequency of 21.35% for ß-thal carriers and 1.36% for coincidence of these two common disorders in the local population. As expected, the 79 patients presented very variable α-globin alterations in combination with ß-globin mutations, showing 31 genotype combined with the coincidence of both Hb disorders. Except the genotypes of 3 ß-thal heterozygotes combined with ααα(anti3.7) triplication and 2 ß-thal carriers with IVS-II-654(C→T)/N combined-α(3.7)/αα presented the phenotype of thalassemia intermedia, and other 74 carriers with co-inheritance of α-thal and ß-thal all presented the phenotype of ß-thal trait. There were significant differences between ß-thal heterozygotes and the carriers with a co-inheritance of both ß+α(0) thal in MCH, MCV and Hb. In addition, there existed significant difference between the carriers with a co-inheritance of both ß+α(+) thal and a co-inheritance of both ß+α(0) thal in MCV, MCH and Hb. CONCLUSION: Compared to that of ß-thal heterozygotes, the carriers with a co-inheritance of α-thal and ß-thal had slighter phenotype with hematological characteristics. It's difficult to distinguish the double heterozygotes with the co-inheritance of α-thal and ß-thal from ß-thal heterozygotes by hematological indexes, the molecular diagnosis should be performed.


Assuntos
Talassemia alfa/genética , Talassemia beta/genética , Criança , China/epidemiologia , Feminino , Frequência do Gene , Genótipo , Humanos , Incidência , Masculino , Talassemia alfa/sangue , Talassemia alfa/epidemiologia , Talassemia beta/sangue , Talassemia beta/epidemiologia
11.
Ann Hematol ; 90(1): 17-22, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20645100

RESUMO

Over 80% of the α-thalassemia cases in southern China are caused by large deletions involving the α-globin gene cluster on chromosome 16p13.3. Here, we characterized a novel 27.6-kb deletion on the α-globin gene cluster in a Chinese family. Its breakpoints were detected to lie between coordinates 9079 and 36718 of the α-globin gene cluster (NG_000006.1), with a total of 27,640 nucleotides deleted. It was designated as -α (27.6) deletion. The proband is a compound heterozygote of --(SEA) and -α (27.6) and he displayed very mild hemoglobin H disease phenotype with Hb 7.9-9.3 g/dl. Phenotypic analysis on heterozygote of this deletion revealed it as α(+) mutation. It leads to a very mild phenotype as adult heterozygotes have normal hematological parameters with the values at the lower border of the normal range. RT-PCR analysis showed that the α-globin mRNA level of the heterozygotes was decreased when compared with that of normal people.


Assuntos
Grupo com Ancestrais do Continente Asiático/genética , Deleção Cromossômica , Cromossomos Humanos Par 16 , Talassemia alfa/genética , Adulto , Pré-Escolar , Análise Mutacional de DNA , Família , Feminino , Humanos , Masculino , Linhagem , Talassemia alfa/etnologia
12.
Hemoglobin ; 34(4): 343-53, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20642332

RESUMO

The 1.357 kb beta-globin gene deletion was identified in a Chinese family by multiplex ligation-dependent probe amplification (MLPA) followed by gap-polymerase chain reaction (gap-PCR) and sequencing. Interestingly, this form of the deletion was linked to a -(G)gamma-(AG)gamma-(A)gamma triplication. The proband, a compound heterozygote for this linked mutant gene and a beta-globin gene [-28 (A>G)] mutation, had a phenotype of beta-thalassemia intermedia (beta-TI). She was not transfusion dependent and had the following parameters: a Hb level of 5.3 g/dL, 72.8% Hb F and 55.1% (G)gamma chain in Hb F. Four members of the family, who were carriers of this linked mutant gene, had a hematological phenotype of beta(0)-thalassemia (beta(0)-thal) with high Hb F and low (G)gamma chain values. RNA analyses showed decreased levels of beta-globin mRNA and increased levels of gamma-globin mRNA in heterozygotes. Haplotype analyses indicated that the unusual form of the beta-globin gene deletion and gamma-globin gene triplication in cis were linked to halotype [+ - - - - - -].


Assuntos
Deleção de Genes , Duplicação Gênica , Globinas beta/genética , gama-Globinas/genética , Sequência de Bases , Criança , China , Análise Mutacional de DNA , Saúde da Família , Feminino , Ligação Genética , Humanos , Masculino , Dados de Sequência Molecular , Linhagem , Homologia de Sequência do Ácido Nucleico , Talassemia beta/genética
13.
Free Radic Res ; 44(5): 577-84, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20370556

RESUMO

Increasing research has concentrated on the anti-tumour efficacy of silibinin, a flavonolignan that is clinically used as an hepatoprotectant. However, previous work has found that silibinin-induced apoptosis is accompanied by protective superoxide (O(2)*-) generation in MCF-7 cells. This study further reports the formation of reactive nitrogen species (RNS) in the same system. It finds that silibinin induces nitric oxide (*NO) generation in a time- and concentration-dependent manner. Moreover, the results support that there exists an inter-regulation pattern between RNS and reactive oxygen species (ROS) generation. In addition, silibinin is also found to induce RNS and ROS generation in the isolated populations of mouse peripheral blood mononuclear cells (PBMCs) and a simple in vivo model of Caenorhabditis elegans.


Assuntos
Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Neoplasias da Mama/metabolismo , Óxido Nítrico/biossíntese , Silimarina/farmacologia , Animais , Apoptose/efeitos dos fármacos , Neoplasias da Mama/patologia , Caenorhabditis elegans/efeitos dos fármacos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Camundongos , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Nitrogênio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Silibina , Fatores de Tempo , Células Tumorais Cultivadas
14.
Free Radic Res ; 44(1): 90-100, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19968587

RESUMO

The pharmacological activity of polyphenolic silibinin from milk thistle (Silybum marianum) is primarily due to its antioxidant property. However, this study found that silibinin promoted sustained superoxide (O(2)(.-)) production that was specifically scavenged by exogenous superoxide dismutase (SOD) in MCF-7 cells, while the activity of endogenous SOD was not changed by silibinin. Previous work proved that silibinin induced MCF-7 cell apoptosis through mitochondrial pathway and this study further proved that O(2)(.-) generation induced by silibinin was also related to mitochondria. It was found that respiratory chain complexes I, II and III were all involved in silibinin-induced O(2)(.-) generation. Moreover, it was found that silibinin-induced O(2)(.-) had protective effect, as exogenous SOD markedly enhanced silibinin-induced apoptosis.


Assuntos
Neoplasias da Mama/metabolismo , Superóxidos/metabolismo , Antioxidantes/farmacologia , Neoplasias da Mama/patologia , Morte Celular , Linhagem Celular Tumoral , Citoproteção/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Retroalimentação Fisiológica/efeitos dos fármacos , Retroalimentação Fisiológica/fisiologia , Feminino , Homeostase/efeitos dos fármacos , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Modelos Biológicos , Proteínas Tirosina Quinases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Silibina , Silimarina/farmacologia , Superóxidos/farmacologia , Regulação para Cima/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
15.
Guang Pu Xue Yu Guang Pu Fen Xi ; 29(12): 3409-11, 2009 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-20210182

RESUMO

Palladium in automotive exhaust catalyst was determined by flame atomic absorption spectrometry (FAAS). The analytical conditions and the coexisting elements interference were studied. The catalyst was dissolved by the mixture of H2O2 and HCl. Pd in the solution was directly determined by FAAS method. The linearity of working curve ranges from 0.1 to 15 microg x mL(-1); the detection limit is 0.029 microg x mL(-1); the relative standard deviation (RSD) range is from 0.8% to 2.5%; and the recovery rate range is from 99.6% to 101.2%. It is a simple and convenient method for accurate analysis of Pd in the exhaust catalysts.

16.
Appl Opt ; 44(4): 527-33, 2005 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-15726949

RESUMO

Several superhydrophobic antireflective silica films have been prepared by a solgel method that uses hexamethyl-disilizane (HMDS) as a modifier. In a high-power laser, laser-induced damage thresholds (LIDTs) of 23-30 J/cm2 were obtained at 1064-nm wavelength with 1-ns pulse duration. By atomic-force microscopy and optical microscopy, the fractal surfaces of films were studied, and multifractal spectra (MFSs) were calculated both before and after laser damage. The two-sided effect of HMDS on particle growth determined the surface fractal of a particle and the multifractal structure of a film's surface. The bigger deltaalpha was, both before and after laser damage, the lower the LIDT was. The effect of methyl groups should be included in the determination of the MFS of the LIDT.

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