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1.
Mol Genet Genomic Med ; 12(1): e2364, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38284450

RESUMO

BACKGROUND: Cystic fibrosis (CF) is an autosomal recessive disorder rarely found in Asian populations. Most males with CF are infertile because of obstructive azoospermia (OA) caused by congenital bilateral absence of the vas deferens (CBAVD). Compound heterozygous mutations of cystic fibrosis transmembrane conductance regulator (CFTR) are among the most common pathogenic factors in CBAVD. However, few genealogical analyses have been performed. METHODS: In this study, whole-exome sequencing and cosegregation analysis were performed in a Chinese pedigree involving two siblings with CBAVD. Moreover, in vitro gene expressions were used to analyze the pathogenicity of a novel CFTR mutation. RESULTS: We identified compound heterozygous mutations of CFTR comprising the known disease-causing variant c.1210-11T>G (also known as IVS9-5 T) and c.2144delA;p.q715fs in two siblings with CBAVD. To verify the effects in vitro, we transfected vectors expressing wild-type and mutated CFTR into 293T cells. The results showed that the CFTR protein containing the frameshift mutation (c.2144delA) was 60 kD smaller. With testicular sperm aspiration/intracytoplasmic sperm injection-embryo transfer (TESA/ICSI-ET), both CBAVD patients fathered healthy offspring. CONCLUSION: Our study revealed that compound heterozygous mutations of CFTR are involved in CBAVD, expanding the known CFTR gene mutation spectrum of CBAVD patients and providing more evidence that compound heterozygous mutations can cause familial CBAVD.


Assuntos
Fibrose Cística , Infertilidade Masculina , Doenças Urogenitais Masculinas , Humanos , Masculino , Infertilidade Masculina/genética , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Linhagem , Sêmen , Mutação , Ducto Deferente/anormalidades , Fibrose Cística/genética , Fibrose Cística/patologia , China
2.
J Cell Mol Med ; 27(20): 3107-3116, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37537752

RESUMO

Primary ciliary dyskinesia (PCD) is a rare autosomal-recessive disease manifested with recurrent infections of respiratory tract and infertility. DNAAF3 is identified as a novel gene associated with PCD and different mutations in DNAAF3 results in different clinical features of PCD patients, such as situs inversus, sinusitis and bronchiectasis. However, the sperm phenotypic characteristics of PCD males are generally poorly investigated. Our reproductive medicine centre received a case of PCD patient with infertility, who presented with sinusitis, recurrent infections of the lower airway and severe asthenozoospermia; However, no situs inversus was found in the patient. A novel homozygous mutation in DNAAF3(c.551T>A; p.V184E) was identified in the PCD patient by whole-exome sequencing. Subsequent Sanger sequencing further confirmed that the DNAAF3 had a homozygous missense variant in the fifth exon. Transmission electron microscopy and immunostaining analysis of the sperms from the patient showed a complete absence of outer dynein arms and partial absence of inner dynein arms, which resulted in the reduction in sperm motility. However, this infertility was overcome by intracytoplasmic sperm injections, as his wife achieved successful pregnancy. These findings showed that the PCD-associated pathogenic mutation within DNAAF3 also causes severe asthenozoospermia and male infertility ultimately due to sperm flagella axoneme defect in humans. Our study not only contributes to understand the sperm phenotypic characteristics of patients with DNAAF3 mutations but also expands the spectrum of DNAAF3 mutations and may contribute to the genetic diagnosis and therapy for infertile patient with PCD.

3.
Materials (Basel) ; 16(8)2023 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-37109945

RESUMO

High-altitude environments are characterized by low air pressures and temperature variations. Low-heat Portland cement (PLH) is a more energy-efficient alternative to ordinary Portland cement (OPC); however, the hydration properties of PLH at high altitudes have not been previously investigated. Therefore, in this study, the mechanical strengths and levels of the drying shrinkage of PLH mortars under standard, low-air-pressure (LP), and low-air-pressure and variable-temperature (LPT) conditions were evaluated and compared. In addition, the hydration characteristics, pore size distributions, and C-S-H Ca/Si ratio of the PLH pastes under different curing conditions were explored using X-ray diffraction (XRD), thermogravimetric analysis (TG), scanning electron microscopy (SEM), and mercury intrusion porosimetry (MIP). Compared with that of the PLH mortar cured under the standard conditions, the compressive strength of the PLH mortar cured under the LPT conditions was higher at an early curing stage but lower at a later curing stage. In addition, drying shrinkage under the LPT conditions developed rapidly at an early stage but slowly at a later stage. Moreover, the characteristic peaks of ettringite (AFt) were not observed in the XRD pattern after curing for 28 d, and AFt transformed into AFm under the LPT conditions. The pore size distribution characteristics of the specimens cured under the LPT conditions deteriorated, which was related to water evaporation and micro-crack formation at low air pressures. The low pressure hindered the reaction between belite and water, which contributed to a significant change in the C-S-H Ca/Si ratio in the early curing stage in the LPT environment.

4.
Sci Rep ; 13(1): 64, 2023 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-36604502

RESUMO

Biallelic variants in Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) are the main pathogenic factor of congenital absence of the vas deferens (CAVD), including congenital bilateral absence of the vas deferens (CBAVD) and congenital unilateral absence of the vas deferens (CUAVD). However, there are few reports about the correlation between CFTR variant and outcomes of assisted reproductive technology (ART) in CAVD patients of China. In this study, 104 patients with CAVD were recruited in Central China, and provided gene detection by the whole-exome sequencing, among them 69% (72/104) carried at least one variant in CFTR and one carried adhesion G protein-coupled receptor G2 (ADGRG2) variant. A total of 81 CAVD patients were treated with ART, of which 21 and 60 carried none or at least one variant in CFTR, respectively. The fertilization rate, cleavage rate, effective embryo rate, implantation rate, clinical pregnancy rate and live birth rate per fresh embryo transfer were compared between patients with and without CFTR variants. It was found that the ART outcomes had no significant difference whether the patients carried the CFTR variant or not. In addition, all of the offspring were healthy after follow-up. In conclusion, rare CFTR variants may play a major role in patients with CAVD in Central China, which were greatly different from other descent. There was no significant difference in ART outcomes in CAVD patients with or without CFTR variants. The limitations of this study were that there was no statistical analysis of the sperm quality through TESA and conclusions were relatively limited due to the small sample size of the study.


Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística , Sêmen , Gravidez , Feminino , Humanos , Masculino , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Mutação , Ducto Deferente/anormalidades , Técnicas de Reprodução Assistida
5.
ACS Omega ; 7(24): 21102-21108, 2022 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-35755345

RESUMO

Most oil source correlation indicators are invalid because of the high maturity of the deep marine strata. Thus, a suitable indicator with high thermal stability requires to be established. In this study, to understand the effect of thermal maturation on the carbon isotopic composition of unsubstituted aromatics, we performed a number of anhydrous thermal simulation experiments involving two typical Chinese shales (lacustrine and marine shales), their corresponding expelled oils, three crude oils, and their associated oil fractions, that is, saturates, aromatics, resins, and asphaltenes (SARA). The generated unsubstituted aromatics were examined in terms of molecular distributions and carbon isotopic composition. The results show that unsubstituted aromatics in different types of samples demonstrated similar variation characteristics. Phenanthrene can be formed continuously in 0.45%/0.55-2.30% R o (equivalent vitrinite reflectance), especially in the high-over maturity stage. However, their carbon isotope composition shows minor variations. The unsubstituted aromatic carbon isotopic information in source rocks can be preserved during the whole pyrolysis process. Their carbon isotopic values in source rocks and their corresponding expelled oils are extremely similar. Furthermore, no evident difference exists in the carbon isotopes of unsubstituted aromatics formed by crude oil and associated oil fractions. These results indicate that these types of parameters are suitable for oil-oil/source correlation in deep marine strata with high-over maturity.

6.
ACS Omega ; 7(1): 480-495, 2022 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-35036717

RESUMO

Cretaceous continental sediments in Sichuan Basin, China, have different colors, and the reasons for their formation are not determined. Based on mineralogical and geochemical characteristics, red beds and nonred beds in the Upper and Lower Cretaceous sedimentary strata in the western Sichuan Basin are described and tested in this study. The test and analysis of the mineral composition, element content, and iron speciation of mudstone samples with gray-green, gray, and red colors in Cangxi, Bailong, and Guankou formations found that the change in hematite content directly causes the color difference of samples. For red mudstone, the average chemical index of alteration, chemical index of weathering, weather eluviation index (Ba), Ca/(Mg*Al), and Al2O3/SiO2 index are 67.75, 79.94, 2.07, 0.26, and 0.26, respectively, indicating that chemical weathering is the most intense. The geochemical indexes corresponding to gray samples are 64.41, 74.91, 2.08, 0.19, and 0.24, respectively. Those corresponding to the gray-green samples are 62.30, 70.68, 2.17, 0.21, and 0.24, with the weakest chemical weathering. The ratio of Cu/Zn and the enrichment factor of V show that red and nonred bed samples are formed in weak oxidation and weak reduction environments, respectively. The red sample contains the highest content of hematite iron. The gray-green sample mainly represents paramagnetic ferrous in clay minerals. The geochemical contents of the gray sample's three iron elements are slightly different, mainly trivalent iron. The change in iron speciation content in different color samples shows that the Fe element forming hematite in red bed samples may come from the weathering of source rock and clay minerals subjected to secondary weathering. At present, it is confirmed that different colors of samples are related to different weathering degrees of source rocks, which can be related to hot, dry/humid climates. It is necessary to distinguish the climate type in combination with other indicators.

7.
Reprod Sci ; 29(2): 475-479, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34231177

RESUMO

Kallmann syndrome (KS) is a rare genetic disorder that is characterized by idiopathic hypogonadotropic hypogonadism associated with anosmia. Genetic variants in ANOS1 gene are the most common mutations associated with X-linked recessive form of KS. Canonical ± 1 or 2 splice site variants in ANOS1 have been described to be responsible for KS. Here, we identified a novel noncanonical splice site variant (c.1062+4T>C) in ANOS1 gene in two siblings with KS by whole-exome sequencing (WES). Sanger sequencing showed this mutation was inherited from their mother, whose brother was a KS patient as well. Through the functional assay in vitro, we found that this mutation resulted in a 50-bp deletion of exon 7, which caused frameshift mutation leading to a premature termination of translation and a truncated anosmin-1 protein. Our results revealed that this noncanonical splice site variant is involved in KS. Thus, it is suggested that we should pay attention to the noncanonical splice site variants when using molecular genetic diagnostics of KS.


Assuntos
Proteínas da Matriz Extracelular/genética , Genes/genética , Síndrome de Kallmann/genética , Proteínas do Tecido Nervoso/genética , Isoformas de Proteínas/genética , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Irmãos , Sequenciamento do Exoma , Adulto Jovem
8.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 38(9): 849-852, 2021 Sep 10.
Artigo em Chinês | MEDLINE | ID: mdl-34487528

RESUMO

OBJECTIVE: To explore the clinical feature and gene variant for two cases of primary male infertility caused by severe asthenospermia and to analyze the etiology of the disease. METHODS: Genomic DNA of peripheral blood samples of patients and their parents was extracted and gene variant analysis of the patients was conducted by using whole exome sequencing. Suspected pathogenic variant was verified by Sanger sequencing and pathogenic analysis. RESULTS: Whole exome sequencing showed that the DNAH1 gene of patient 1 had two heterozygous variants of c.2016T>G(p.Y672X) and c.6017T>G (p.V2006G). The DNAH1 gene of patient 2 had a homozygous variant of c.2610G>A(p.W870X), which were inherited from his father and mother, respectively. According to American College of Medical Genetics and Genomics standards and guidelines, the c.2016T>G (p.Y672X) and c.2610G>A (p.W870X) varaints of DNAH1 gene were predicted to be pathogenic (PVS1+PM2+PM3+PP3). CONCLUSION: The two patients of multiple morphological abnormalities of the sperm flagella may be caused by DNAH1 gene variant, which has resulted in primary male infertility.


Assuntos
Dineínas , Infertilidade Masculina , Cauda do Espermatozoide , Dineínas/genética , Genômica , Humanos , Infertilidade Masculina/genética , Masculino , Mutação , Cauda do Espermatozoide/patologia , Sequenciamento do Exoma
9.
Zhonghua Nan Ke Xue ; 26(9): 803-806, 2020 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-33377703

RESUMO

OBJECTIVE: To explore the application value of sperm-hyaluronan binding (SHB) assay in in vitro fertilization and embryo transfer (IVF-ET). METHODS: This retrospective study included 163 cases of IVF-ET performed in our hospital from January to August 2019 due to female fallopian tube abnormality-induced infertility. The men were found with normal seminal parameters at semen analysis. According to the SHB rate, we divided the patients into a normal group (n = 126) and an abnormal group (n = 37) and analyzed the general conditions and the rates of normal fertilization, cleavage, available embryos, embryo implantation and clinical pregnancy. RESULTS: Statistically significant differences were observed between the normal and abnormal groups in the rates of SHB, normal fertilization and available embryos (P < 0.01 or P < 0.05), but not in the general conditions or the rates of cleavage, embryo implantation and clinical pregnancy. CONCLUSIONS: The SHB rate is not correlated with sperm concentration or the percentages of progressively motile sperm and morphologically normal sperm. Sperm-hyaluronan binding assay helps predict the outcomes of IVF-ET and embryo quality. An SHB rate of <58.5% indicates low rates of normal fertilization and available embryos, but has no significant correlation with the rates of embryo implantation and clinical pregnancy.


Assuntos
Transferência Embrionária , Fertilização In Vitro , Ácido Hialurônico/metabolismo , Espermatozoides/metabolismo , Feminino , Fertilização , Humanos , Masculino , Gravidez , Estudos Retrospectivos
10.
Int J Nanomedicine ; 15: 3235-3250, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32440121

RESUMO

BACKGROUND: Metal-organic frameworks (MOFs) have attracted intensive research interest in the biomedical field because of their unique properties. However, in order to realize the high loading capacity and therapeutic efficacy, it is still urgent to develop a multifunctional MOFs-based nanoplatform. MATERIALS AND METHODS: Herein, a pH/near-infrared (NIR) dual-responsive drug delivery system based on zeolitic imidazolate framework-8 (ZIF-8) is constructed for synergistic chemo-photothermal therapy and dual-modal magnetic resonance (MR)/photoacoustic (PA) imaging. The doxorubicin hydrochloride (DOX) is embedded into ZIF-8 through one-pot method, and the resultant ZIF-8/DOX is then successively modified with polydopamine, Mn ions and poly(ethylene glycol). The obtained ZIF-8/DMPP is systematically characterized, and both its in vitro and in vivo biological effects are evaluated in detail. RESULTS: The ZIF-8/DMPP possesses a high drug-loading content of 18.9% and displays appropriate size and morphology. The pH-dependent degradation and drug release behavior of prepared ZIF-8/DMPP are confirmed. Importantly, the results demonstrate that the photothermal effect of ZIF-8/DMPP under NIR laser irradiation can significantly accelerate its drug releasing rate, further improving the intracellular drug concentrations. Thereafter, the augmented chemotherapeutic efficiency by photothermal effect against cancer cells is verified both in vitro and in vivo. Besides, the favorable MR and PA imaging capacity of ZIF-8/DMPP is also evidenced on the tumor model. CONCLUSION: Taken together, the surface engineering of ZIF-8-based nanocarrier in this work offers a promising strategy for the multifunctional MOFs-based drug delivery system.


Assuntos
Portadores de Fármacos/química , Hipertermia Induzida , Imageamento Tridimensional , Raios Infravermelhos , Estruturas Metalorgânicas/química , Nanopartículas/química , Nanotecnologia/métodos , Fototerapia , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Doxorrubicina/farmacologia , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Concentração de Íons de Hidrogênio , Indóis/química , Camundongos Endogâmicos BALB C , Nanopartículas/ultraestrutura , Polímeros/química , Temperatura
11.
Data Brief ; 29: 105101, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31993463

RESUMO

This work presents a dataset which provides information on the influence of aromatic nuclei on the carbon isotope of gases. Gases analyzed herein were obtained by pyrolysis of model compounds and kerogens. The carbon isotope of gases from paraffin cracking with and without the addition of aromatic nuclei is summarized. We also obtained carbon isotope data for the gases from different type of kerogens, which indicate the role of aromatic nuclei in the formation of natural gases from kerogen cracking. Further interpretation and discussion of these data can be found in the related research article entitled "The methylation of aromatic nuclei - I: Implications for the geochemical evolution of gas" [1].

12.
Eur J Mass Spectrom (Chichester) ; 26(3): 175-186, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31874577

RESUMO

Fragmentation mechanisms of the singly protonated glutathione (γ-ECG) and its synthetic analogue peptides (ECG and PPECG) have been investigated by liquid chromatography tandem-mass spectrometry and theoretical calculations. In the mass spectra, similar fragmentation patterns were observed for γ-ECG and ECG, but a completely different one was found in the case of PPECG. The E-C amide bond cleavage is the predominant pathway for the fragmentation of γ-ECG and ECG, whereas the additional N-terminal prolyl residues in PPECG significantly suppress the E-C amide bond cleavage. Theoretical calculations reveal that the fragmentation efficiencies of the E-C bonds in the protonated γ-ECG and ECG are much higher than that in the protonated PPECG, being attributed to their lower barriers of the potential energy; clearly the introduction of two prolyl residues can increase substantially the potential energy barrier. In the proposed mechanism, the protonated E-C amide bonds in the three peptides are first weakened followed by a nucleophilic addition by the glutamyl carboxyl oxygen atom in side chain, leading to the breaking of the E-C amide bonds. However, the processes of E-C bond fragmentation for three protonated analogs were not collaborative. Protonated amide bonds first fragment, then the nucleophilic addition by the side chain of glutamyl carboxyl oxygen atom takes places. On the other hand, the prolyl residues in PPECG can largely diminish the nucleophilic addition, resulting in a much lower efficiency of its E-C amide bond breaking. Distance analysis indicates that breaking the E-C amide bonds in the protonated γ-ECG, ECG, and PPECG ions could not occur without the assistance from the nucleophilic attack, highlighting an asynchronous collaborative process in the bond breakings.


Assuntos
Ácido Glutâmico/química , Glutationa/química , Peptídeos/química , Íons/química , Espectrometria de Massas , Estrutura Molecular
13.
Biomed Pharmacother ; 101: 691-697, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29522949

RESUMO

BACKGROUND: Preeclampsia (PE), characterized by hypertension and proteinuria, is a leading cause of perinatal and maternal mortality. Considering that mutation of H19 gene is closely associated with PE, we aimed to explore the functional role of long non-coding RNA H19 (lncRNA-H19) in trophoblast cells. METHODS: Expression of lncRNA-H19 in placenta tissues from patients with PE and healthy pregnant women after delivery was determined by quantitative reverse transcription PCR. Then, lncRNA-H19 was abnormally expressed in JEG-3 and HTR-8 cells by stable cell transfection. Cell viability and invasion were assessed by using CCK-8 and Matrigel-coated Millicell system, respectively. Expression of key proteins associated with invasion and autophagy as well as key kinases in the phosphatidylinositol-3-kinase (PI3K)/AKT/mechanistic target of rapamycin (mTOR) pathways were measured by Western blot analysis. Number of GFP-labeled autophagosomes was counted under a confocal microscope. RESULTS: Level of lncRNA-H19 in the placenta tissues from PE patients was higher than that from healthy controls. LncRNA-H19 overexpression reduced cell viability but increased invasion of JEG-3 and HTR-8 cells. LncRNA-H19 silence showed the opposite effects. In addition, lncRNA-H19 overexpression promoted autophagy in trophoblast cells. Furthermore, phosphorylated levels of key kinases in the PI3K/AKT/mTOR pathways were enhanced by lncRNA-H19 overexpression while were reduced by lncRNA-H19 silence. CONCLUSION: LncRNA-H19, which was up-regulated in PE, reduced cell viability but promoted invasion and autophagy in trophoblast cells, along with activation of the PI3K/AKT/mTOR pathways. Our study provides a theoretical basis for pathogenesis of PE, aiding to identification of novel therapeutic strategies for PE.


Assuntos
Fosfatidilinositol 3-Quinase/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Longo não Codificante/biossíntese , Serina-Treonina Quinases TOR/metabolismo , Trofoblastos/metabolismo , Autofagia/fisiologia , Linhagem Celular , Sobrevivência Celular/fisiologia , Feminino , Expressão Gênica , Humanos , Pré-Eclâmpsia/metabolismo , Pré-Eclâmpsia/patologia , Gravidez , RNA Longo não Codificante/genética , Transdução de Sinais/fisiologia , Trofoblastos/patologia
14.
Artigo em Inglês | MEDLINE | ID: mdl-27925506

RESUMO

Surface soils from the tourist areas of the northwest Qinling Mountains were analyzed to determine the concentrations, probable sources and potential risks of hydrocarbons. Concentrations of aliphatic and aromatic hydrocarbons ranged from 4.18 to 3240 ng g-1 and 0.0462 to 101 ng g-1 dry weight, respectively. The extent of soil contamination by hydrocarbons was generally typified by unpolluted to slightly polluted levels. The incremental lifetime cancer risks (ILCRs) for exposure to soil-borne PAHs indicated complete safety for tourists. Early diagenesis of natural products, bacteria activities and petroleum were the three main sources of aliphatic hydrocarbons, while the transport of air pollutants from pyrolytic processes was the main origin of PAHs. Because the photochemical reaction of PAHs in the atmosphere would produce lower ratios for Ant/(Ant + Phe), BaA/(BaA + Chr) and IcdP/(IcdP + BghiP), but a higher ratio for Fla/(Fla + Pyr), the source classification highly depended on the diagnostic ratios chosen. The plot of ΣCOM/Σ13PAH vs. ΣLMW/ΣHMWPAH provide additional information to distinguish the origins of PAHs, and it showed a cluster of pyrogenic sources except for sample JFS-8. Four sources were resolved by principal component analysis: (1) a low temperature pyrogenic process related to the use of fossil fuel and biomass, such as charcoal, straw and wood, which contributes 63.1% of the measured PAHs; (2) the potential contribution of diagenetic processes, contributing 18.4%; (3) traffic emissions, contributing 9.27%; and (4) bioconversion/bacterial action, contributing 5.82%. Additionally, there was a good exponential relationship (r2 = 0.969) between the natural n-alkanes ratio (NAR) and carbon preference index for C23-C35 (CPI23-35) for all samples, which is of great use for the determination of the origins of aliphatic hydrocarbon.


Assuntos
Monitoramento Ambiental , Ácidos Graxos/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes do Solo/análise , Solo/química , China , Poluição Ambiental/análise , Medição de Risco
15.
J Chromatogr A ; 1372C: 228-235, 2014 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-25465020

RESUMO

Compound specific isotope analysis (CSIA) of normal-level hydrocarbons (C1-C4) in natural gas is often successfully used in natural gas origin identification and classification, but little progress so far has been made for trace level hydrocarbons (C5-C14) in natural gas. In this study, we developed a method for rapid analysis of carbon isotopic ratios for trace hydrocarbons in natural gas samples. This method can be described as a combined approach characterized by solid phase micro-extraction (SPME) technique coupled to gas chromatography isotope ratio mass spectrometry (GC/IRMS). In this study, the CAR-PDMS fiber was chosen as the SPME adsorptive material after comparative experiments with other four fibers, and the parameters, including equilibration time, extraction temperature and desorption time, for efficient extraction of trace hydrocarbons were systematically optimized. The results showed the carbon isotopic fractionation was not observed as a function of equilibration time and extraction temperature. And the δ13C signatures determined by SPME-GC/IRMS were in good agreement with the known δ13C values of C5-C14 measured by GC-IRMS, and the accuracy is generally within ±0.5‰. Five natural gas samples were analyzed using this method, and the δ13C values for C5-C14 components were obtained with satisfied repeatability. The SPME-GC/IRMS approach fitted with CAR-PDMS fiber is well suited for the preconcentration of trace hydrocarbons and provides so far the most reliable carbon isotopic analysis for trace compounds in natural gas.

16.
Chemistry ; 18(23): 7189-95, 2012 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-22517611

RESUMO

Although considerable effort has been devoted to the design of various nanoprobes for the fluorescent detection of multiple biomarkers in a single assay, they often suffer from emission-overlapping, owing to small Stokes shifts and wide emission spectra, which results in cross-talk and inaccurate quantification. Herein, we report the design and synthesis of a new nanoprobe for multienzyme detection with completely resolved emission peaks under single-wavelength excitation. The probe was assembled by attaching a cleavable peptide spacer, which was comprised from a matrix metalloproteinase-2 (MMP-2) substrate and a MMP-7 substrate, onto the surface of gold nanoparticles (AuNPs) through cysteine residues. A lanthanide complex, BCTOT-Eu(III) (BCTOT=1,10-bis(5'-chlorosulfo-thiophene-2'-yl)-4,4,5,5,6,6,7,7-octafluorodecane-1,3,8,10-tetraone), and 7-amino-4-methylcoumarin (AMC) were attached to the N terminus and the C terminus of the peptide, respectively. In the presence of one or both targeting enzymes, the substrate was cleaved and fluorescence resonance energy transfer (FRET) between the dyes and AuNPs was prohibited, thereby resulting in the dramatic fluorescence emission of dyes. Importantly, there was no emission cross-talk between the two dyes, thereby ensuring accurate detection of each enzyme. Based on this, the simultaneous fluorescence image of MMP-2 and MMP-7 was accomplished in living cells under single wavelength excitation. The apparent differences in the fluorescence imaging indicated distinct differences between the expression levels of MMPs between the human normal liver cells and the human hepatoma cells.


Assuntos
Corantes Fluorescentes , Ouro/química , Metaloproteinase 2 da Matriz/efeitos dos fármacos , Metaloproteinase 7 da Matriz/efeitos dos fármacos , Nanopartículas Metálicas/química , Fluorescência , Corantes Fluorescentes/síntese química , Células Hep G2 , Humanos , Fígado/citologia , Metaloproteinase 2 da Matriz/análise , Metaloproteinase 7 da Matriz/análise
17.
Huan Jing Ke Xue ; 30(12): 3658-62, 2009 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-20187403

RESUMO

The solubilization thermodynamics and kinetics characteristics of hydrophobic pollutants anthracene in the humic acid micellar solutions have been investigated by using batch equilibrium test. The results showed that the solubilization rate of anthracene was significantly enhanced with increasing temperature. The solubilization process of anthracene was spontaneous, endothermic and entropy increasing with deltaG(theta) = -1.682 kJ/mol, deltaH(theta) = 11.96 kJ/mol, deltaS(theta) = 45.78 J/(K x mol) in 25 degrees C, as well as deltaG(theta) = -2.140 kJ/mol and -2.598 kJ/mol in 35 degrees and 45 degrees C, respectively. The solubilization data of anthracene well fitted Elovich kinetics model.


Assuntos
Antracenos/química , Substâncias Húmicas , Poluentes do Solo/química , Termodinâmica , Biodegradação Ambiental , Cinética , Solubilidade
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