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1.
Small ; 20(24): e2311174, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38174619

RESUMEN

Modulating the coordination configuration of single Fe atom has been an efficient strategy to strengthen the redox dynamics for lithium-sulfur batteries (LSBs) but remains challenging. Herein, the single Fe atom is functioned with nitrogen and carbon atoms in the first shell, and simultaneously, oxidized sulfur (─SOx) in the second shell, which presents a lower antibonding state and well address the redox activity of sulfur cathodes. In the ternary-coordinated single Fe atom catalyst (FeN2C2-SOx-NC), the binary structure of FeN2C2 provides a lower Fe-S bonding strength and d-p orbital hybridization, which obviously optimizes the adsorption and desorption behavior of sulfur species during the reduction and oxidation reaction processes. Simultaneously, the ─SOx redistributes the electron density of the coordinating nitrogen atoms, which possesses high electron-withdrawing ability and develops electrocatalytic activity. As a result, the sulfur cathodes with FeN2C2-SOx-NC present an excellent high-rate cyclic performance, accompanied by a capacity decay rate of 0.08% per cycle for 500 cycles at 4.0 C. This study provides new insights for optimizing the redox dynamics of sulfur cathodes in LSBs at the atomic level.

2.
BMC Vet Res ; 20(1): 151, 2024 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-38643127

RESUMEN

BACKGROUND: Numerous previous reports have demonstrated the efficacy of Lactic acid bacteria (LAB) in promoting growth and preventing disease in animals. In this study, Enterococcus faecium ZJUIDS-R1 and Ligilactobaciiius animalis ZJUIDS-R2 were isolated from the feces of healthy rabbits, and both strains showed good probiotic properties in vitro. Two strains (108CFU/ml/kg/day) were fed to weaned rabbits for 21 days, after which specific bacterial infection was induced to investigate the effects of the strains on bacterial diarrhea in the rabbits. RESULTS: Our data showed that Enterococcus faecium ZJUIDS-R1 and Ligilactobaciiius animalis ZJUIDS-R2 interventions reduced the incidence of diarrhea and systemic inflammatory response, alleviated intestinal damage and increased antibody levels in animals. In addition, Enterococcus faecium ZJUIDS-R1 restored the flora abundance of Ruminococcaceae1. Ligilactobaciiius animalis ZJUIDS-R2 up-regulated the flora abundance of Adlercreutzia and Candidatus Saccharimonas. Both down-regulated the flora abundance of Shuttleworthia and Barnesiella to restore intestinal flora balance, thereby increasing intestinal short-chain fatty acid content. CONCLUSIONS: These findings suggest that Enterococcus faecium ZJUIDS-R1 and Ligilactobaciiius animalis ZJUIDS-R2 were able to improve intestinal immunity, produce organic acids and regulate the balance of intestinal flora to enhance disease resistance and alleviate diarrhea-related diseases in weanling rabbits.


Asunto(s)
Infecciones Bacterianas , Enterococcus faecium , Microbioma Gastrointestinal , Lactobacillales , Probióticos , Conejos , Animales , Enterococcus faecium/fisiología , Probióticos/uso terapéutico , Probióticos/farmacología , Diarrea/prevención & control , Diarrea/veterinaria , Infecciones Bacterianas/veterinaria , Inmunidad
3.
Nanotechnology ; 34(15)2023 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-36584388

RESUMEN

The battery performance of sulfur cathode has obviously depended on the redox reaction kinetics of polysulfides upon cycling. Herein, an effective strategy was proposed to achieve the conversion from 2H (semiconductor phase) to 1T (metal phase) in hollow nano-flowered molybdenum selenide sphere (HFSMS) through crystal phase engineering. The HFSMS with different phase ratio was realized by regulating the proportion of reducing agents. Specifically, the 1T phase content can reach up to 60.8%, and then subsequently decreased to 59.1% with the further increase of the reducing agent. The as-prepared HFSMS with the 1T phase content of 60.8% showed a smallest Tafel slopes (49.99 and 79.65 mV/dec in reduction and oxidation process, respectively), fastest response time and highest response current (520 s, 0.459 mA in Li2S deposition test), which further exhibited excellent catalytic activity and faster reaction kinetics. This result was verified by electrochemical performance, which manifested as stable cycle life with only 0.112% capacity decay per cycle. It was found that the hollow structure can ensures a rich sulfur storage space, and effectually buffer the volume changes of the active substance. More importantly, the improved performance is attributed to the introduction of the 1T phase, which significantly improves the catalytic activity of MoSe2with promoting the polysulfide conversion.

4.
Molecules ; 24(24)2019 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-31861201

RESUMEN

A facile strategy, engineered for low-cost mass production, to synthesize biomass-derived activated carbon/reduced graphene oxide composite electrodes (GBPCs) by one-pot carbonization of blotting papers containing graphene oxide (GO) and zinc chloride (ZnCl2) was proposed. Benefitting from the water absorption characteristic of blotting papers in which the voids between the celluloses can easily absorb the GO/ZnCl2 solution, the chemical activation and reduction of GO can synchronously achieve via one-step carbonization process. As a result, the GBPCs deliver a large specific surface area to accumulate charge. Simultaneously, it provides high conductivity for electron transfer. The symmetric supercapacitor assembled with the optimal GBPCs in 6 M KOH electrolyte exhibits an excellent specific capacitance of 204 F g-1 (0.2 A g-1), outstanding rate capability of 100 F g-1 (20 A g-1). Meanwhile, it still keeps 90% of the initial specific capacitance over 10,000 cycles. The readily available raw material, effective chemical activation, simple rGO additive, and resulting electrochemical properties hold out the promise of hope to achieve low-cost, green, and large-scale production of practical activated carbon composite materials for high-efficiency energy storage applications.


Asunto(s)
Carbón Orgánico/química , Capacidad Eléctrica , Electrodos , Grafito/química , Algoritmos , Biomasa , Electroquímica , Porosidad , Temperatura
5.
Nanomicro Lett ; 16(1): 209, 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38842597

RESUMEN

With the development of science and technology, the scale of industrial production continues to grow, and the types and quantities of gas raw materials used in industrial production and produced during the production process are also constantly increasing. These gases include flammable and explosive gases, and even contain toxic gases. Therefore, it is very important and necessary for gas sensors to detect and monitor these gases quickly and accurately. In recent years, a new two-dimensional material called MXene has attracted widespread attention in various applications. Their abundant surface functional groups and sites, excellent current conductivity, tunable surface chemistry, and outstanding stability make them promising for gas sensor applications. Since the birth of MXene materials, researchers have utilized the efficient and convenient solution etching preparation, high flexibility, and easily functionalize MXene with other materials to prepare composites for gas sensing. This has opened a new chapter in high-performance gas sensing materials and provided a new approach for advanced sensor research. However, previous reviews on MXene-based composite materials in gas sensing only focused on the performance of gas sensing, without systematically explaining the gas sensing mechanisms generated by different gases, as well as summarizing and predicting the advantages and disadvantages of MXene-based composite materials. This article reviews the latest progress in the application of MXene-based composite materials in gas sensing. Firstly, a brief summary was given of the commonly used methods for preparing gas sensing device structures, followed by an introduction to the key attributes of MXene related to gas sensing performance. This article focuses on the performance of MXene-based composite materials used for gas sensing, such as MXene/graphene, MXene/Metal oxide, MXene/Transition metal sulfides (TMDs), MXene/Metal-organic framework (MOF), MXene/Polymer. It summarizes the advantages and disadvantages of MXene composite materials with different composites and discusses the possible gas sensing mechanisms of MXene-based composite materials for different gases. Finally, future directions and inroads of MXenes-based composites in gas sensing are presented and discussed.

6.
J Colloid Interface Sci ; 669: 466-476, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38723535

RESUMEN

Heterostructure engineering is considered a crucial strategy to modulate the intrinsic charge transfer behavior of materials, enhance catalytic activity, and optimize sulfur electrochemical processes. However, parsing the role of heterogeneous interface-structure-property relationships in heterostructures is still a key scientific issue to realize the efficient catalytic conversion of polysulfides. Based on this, molybdenum carbide (Mo2C) was successfully partial reduced to molybdenum metal (Mo) via a thermal reduction at high-temperature and the typical Mo-Mo2C-based Mott-Schottky heterostructures were simultaneously constructed, which realized the modulation of the electronic structure of Mo2C and optimized the conversion process of lithium polysulfides (LPS). Compared with single molybdenum carbide, the modulated molybdenum carbide acts as an electron donor with stronger Mo-S bonding strength as well as higher polysulfide adsorption energy, faster Li2S conversion kinetics, and greatly facilitates the adsorption → catalysis process of LPS. As a result, yolk-shell Mo-Mo2C heterostructure (C@Mo-Mo2C) exhibits excellent cycling performance as a sulfur host, with a discharge specific capacity of 488.41 mAh g-1 for C@Mo-Mo2C/S at 4 C and present an excellent high-rate cyclic performance accompanied by capacity decay rate of 0.08 % per cycle after 400 cycles at 2 C. Heterostructure-acting Mo2C electron distribution modulation engineering may contributes to the understanding of the structure-interface-property interaction law in heterostructures and further enables the efficient modulation of the chemical behavior of sulfur.

7.
ACS Appl Mater Interfaces ; 15(35): 41504-41515, 2023 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-37611062

RESUMEN

As for the conversion-type iron fluoride (FeF3) cathode material with multielectron reactions for lithium-ion batteries (LIBs), sluggish reaction kinetics and low electrical conductivity pose certain limitations for the long-lasting reversible conversion processes. Herein, the three-dimensional porous nitrogen-doped carbon matrix in situ anchoring FeF3 nanocavities coated by graphitized carbon (FeF3/GC) are rationally prepared. Through the Kirkendall effect, the low-temperature fluorination of NF3 enables the resultant hollow FeF3 nanoparticles to possess a large number of lithium storage cavities and outer graphitized carbon structure, further effectively buffering the expansion of volume. The FeF3/GC cathode delivers a superior discharge capacity of 504.2 mAh g-1 after 1200 cycles at 1000 mA g-1, with a capacity decay rate of only 0.01% per cycle. Even at a rate of 5000 mA g-1, the composite cathode still delivers a discharge capacity of 309.6 mAh g-1. Impressively, the existence of graphitized carbon and the short Li+ diffusion length ensure fast electron/ion transfer, which significantly enhances the conversion reaction kinetics. This study aims to provide a promising strategy for the efficiency enhancement of multielectron cathode conversion reactions for LIBs.

8.
RSC Adv ; 12(16): 9917-9922, 2022 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-35424929

RESUMEN

As a typical transition metal dichalcogenide (TMD), molybdenum disulphide (MoS2) has become one of the most promising anode materials for lithium-ion batteries (LIBs) due to its desirable electrochemical properties. But the development of commercial MoS2 is limited by the problem of agglomeration. Thus, the production of MoS2 nanosheets with few (<10) layers is highly desired but remains a great challenge. In this work, a facile and scalable approach is developed to prepare large-flake, few-layer (4-8) MoS2 nanosheets with the assistance of ultrasonics. Simultaneously, the as-prepared MoS2 nanosheets and commercial bulk MoS2 were analysed under multiple spectroscopic techniques and a series of electrochemical tests to understand the dependence of electrochemical performance on structural properties. When used as anode materials for LIBs, the obtained MoS2 nanosheets provide a reversible capacity of 716 mA h g-1 at 100 mA g-1 after 285 cycles, and demonstrated an excellent capacity retention rate of up to 80%. Compared with that of commercial MoS2 (14.8%), the capacity retention rate of our MoS2 nanosheets has a significant improvement. This work explored the ability of few-layered MoS2 nanosheets in the field of LIBs while suggesting the commercialization of the MoS2 by an ultrasonicated ball milling exfoliation technique.

9.
Mar Pollut Bull ; 57(6-12): 357-64, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18423495

RESUMEN

Dietary intake is one of the important routes of human exposure to brominated flame retardants (BFRs) such as polybrominated diphenyl ethers (PBDEs). The use of PBDEs may also result in exposure to polybrominated dibenzo-p-dioxins and dibenzofurans (PBDDs/DFs), as these compounds are impurities in technical mixtures of BFRs and can also be formed unintentionally by the same processes that generate chlorinated dioxins. This study determined the concentrations of polybrominated compounds in common seafood in Guangzhou and Zhoushan, and assessed the health risks of these chemicals via consumption of contaminated seafood. Seafood samples (fish, bivalves, shrimp, crab, and cephalopods) purchased from local markets in 2003 and 2004 were analyzed for PBDEs and PBDDs/DFs. The highest concentration of total PBDEs (46.3 ng g(-1) lipid wt.) was detected in fish from Guangzhou, in which BDEs 47 and 209 were the two predominant congeners. The total daily intakes of PBDEs, PBDDs, and PBDFs were, 946, 6.39, and 6.54 pg kg(-1) body weight (bw) in Guangzhou, and 489, 4.99, and 7.65 pg kg(-1) bw in Zhoushan, respectively. The hazard ratios for PBDDs and PBDFs were both greater than unity, indicating that these compounds may pose some health risks to the local population.


Asunto(s)
Contaminación de Alimentos , Indicadores de Salud , Hidrocarburos Bromados/metabolismo , Éteres Fenílicos/metabolismo , Bifenilos Polibrominados/metabolismo , Alimentos Marinos/análisis , Contaminantes Químicos del Agua/metabolismo , Animales , China , Dioxinas/metabolismo , Ingestión de Alimentos , Contaminación de Alimentos/prevención & control , Furanos/metabolismo , Éteres Difenilos Halogenados , Humanos , Medición de Riesgo
10.
Environ Pollut ; 148(1): 31-9, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17254684

RESUMEN

This study determined the concentrations of organochlorine contaminants in common seafood in two Chinese coastal cities (Guangzhou and Zhoushan), and assessed the health risk due to the daily consumption of contaminated seafood. Twenty-six pooled samples, belonging to five food categories (fish, bivalves, shrimp, crab, and cephalopods), were purchased from local markets in Guangzhou and Zhoushan in 2003 and 2004. These samples were analyzed for total polychlorinated biphenyls (PCBs), non- and mono-ortho-PCBs (coplanar PCBs), polychlorinated naphthalenes (PCNs), and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/DFs). The concentrations of total PCBs and coplanar PCBs in fish samples were higher in Guangzhou than in Zhoushan, while the levels of PCNs and PCDDs/DFs were comparable between the two cities. The total daily intake values of dioxin-like compounds were 1.05 and 0.86pg WHO-TEQ/kg body weight in Guangzhou and Zhoushan, respectively. Hazard ratios of non-cancer risk in the two cities were all less than unity.


Asunto(s)
Contaminantes Ambientales/análisis , Contaminación de Alimentos/análisis , Hidrocarburos Aromáticos/toxicidad , Hidrocarburos Policíclicos Aromáticos/análisis , Alimentos Marinos , Benzofuranos/análisis , Benzofuranos/toxicidad , China , Contaminantes Ambientales/toxicidad , Humanos , Hidrocarburos Aromáticos/análisis , Naftalenos/análisis , Naftalenos/toxicidad , Bifenilos Policlorados/análisis , Bifenilos Policlorados/toxicidad , Dibenzodioxinas Policloradas/análogos & derivados , Dibenzodioxinas Policloradas/análisis , Dibenzodioxinas Policloradas/toxicidad , Hidrocarburos Policíclicos Aromáticos/toxicidad , Medición de Riesgo
11.
Chemosphere ; 67(9): 1877-86, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17207518

RESUMEN

Pine needles were selected as cost effective and easy collectable matrices suitable for long-term monitoring of the lower troposphere pollution with polychlorinated biphenyls and polychlorinated naphthalenes. The fingerprints of PCNs and PCBs in the top layers of agricultural soils were used for determination of point sources of pollution for terrestrial ecosystems. The new idea based on the use of nona- and decachlorinated isomers fingerprint as an additional tool suitable for the identification of potential point sources of pollution with PCBs, seemed to be a capable tool to identify contamination of soil and ambient air related to former manufacturing and the use of highly chlorinated technical PCB preparations.


Asunto(s)
Aire/análisis , Monitoreo del Ambiente , Contaminantes Ambientales/análisis , Naftalenos/análisis , Pinus/química , Bifenilos Policlorados/análisis , Suelo/análisis , Movimientos del Aire , Cromatografía de Gases y Espectrometría de Masas , Residuos Industriales , Hojas de la Planta/química , Polonia , Factores de Tiempo
12.
Environ Int ; 32(5): 676-81, 2006 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-16624408

RESUMEN

Sediments from two rivers in China, the Haihe and Dagu Rivers, were examined for estrogenic activity using an estrogen receptor (ER)-mediated in vitro bioassay system. ER-active compounds were isolated from sediments by Soxhlet extraction, and the crude extracts were fractionated using a florisil column into three fractions. The estrogenic activity of each extract was detected by measuring luciferase activity in the human breast cancer cell line MCF-7 transfected with a luciferase receptor gene. Significant estrogenic activity was observed in each total extract. The 17beta-estradiol equivalents (E2-EQs) ranged from 8.24 to 95.28 ng E2 g(-1) dw. As a result, the relative estrogenic potencies of three fractions in this study descended in the order of Fraction 3>Fraction 2>Fraction 1. The results of the bioassay analysis indicated the heavy pollution status of these sites with estrogenic contaminants. In this study, five selected chemicals, the natural estrogens 17beta-estradiol (E2) and estrone (E1), and the xeno-estrogens 4-octylphenol (OP), 4-nonylphenol (NP), and Bisphenol A (BPA) were also analyzed using the in vitro bioassay. The estrogenic activity of these chemicals were E2>E1>NP>OP>BPA.


Asunto(s)
Bioensayo , Monitoreo del Ambiente , Estrógenos/análisis , Sedimentos Geológicos/análisis , Ríos/química , Contaminantes Químicos del Agua/análisis , Bioensayo/métodos , Línea Celular Tumoral , China , Monitoreo del Ambiente/métodos , Estrógenos/química , Femenino , Sedimentos Geológicos/química , Humanos , Sensibilidad y Especificidad
13.
Chemosphere ; 63(7): 1222-30, 2006 May.
Artículo en Inglés | MEDLINE | ID: mdl-16325885

RESUMEN

Total concentrations of compounds that can cause activation of the aryl hydrocarbon receptor (AhR) in extracts of river sediments from various locations in the Haihe and Dagu Rivers, Tianjin, China were determined by use of the in vitro H4IIE-luc cell line. AhR-active compounds were isolated from sediments by Soxhlet extraction, and the crude extracts were fractionated using a Florisil column into three Fractions. The response of samples was compared to the TCDD standard and expressed as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) equivalents (TCDD-EQs). Significant dioxin-like activity was observed in each sample. The TCDD-EQs in crude extracts of sediments (SCEs), as determined with the bioassay were 2-4 times greater than the sum of the TCDD-EQs of the eluent from fractions separated with a Florisil column. The results also showed that Fractions 2 and 3 contained most of the AhR-mediated activity. The results obtained by using the bioassay were compared with those of previous measurements of the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) and the structurally-similar AhR-active polychlorinated biphenyls (PCBs). It was determined that sediments from the Dagu River contained greater concentrations of TCDD-EQ than did sediments from the Haihe River except at Jingangqiao (location R3), which is associated with industrial activities in the adjacent densely populated area. The concentrations of TCDD-EQs, based on the EC20 and the relative potency ranges, of SCEs ranged from 330 to 930 and 1200 to 13,900 pg TCDD-EQ g(-1) dry wt in Haihe and Dagu Rivers, respectively.


Asunto(s)
Monitoreo del Ambiente , Sedimentos Geológicos/química , Receptores de Hidrocarburo de Aril/metabolismo , Ríos/química , Transducción de Señal/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Animales , Bioensayo , Línea Celular , China , Relación Dosis-Respuesta a Droga , Luciferasas/genética , Receptores de Hidrocarburo de Aril/genética , Contaminantes Químicos del Agua/análisis
14.
Zhonghua Zhong Liu Za Zhi ; 28(6): 429-32, 2006 Jun.
Artículo en Zh | MEDLINE | ID: mdl-17152488

RESUMEN

OBJECTIVE: To investigate the interrelationship of genetic polymorphisms in folate metabolic enzymes (MTHFRC677T, MTHFRA1298C, MTRA2756G and MTRRA66G) and their combinative effects with colorectal cancer (CRC). METHODS: A nested case-control study was designed and carried out. 140 CRC patients and 343 control subjects were included in this study. Polymorphisms of folate metabolic enzyme genes were genotyped by PCR-restriction fragment length polymorphism method. Risk of CRC was estimated by unconditional logistic model, and P value for interaction was calculated by likelihood test. RESULTS: The allele of MTR2756G showed a positive association with CRC (OR = 2.04, 95% CI = 1.22 - 3.40). Those with MTHFR1298AA and MTR 2756AG/GG genotypes had an elevated risk with CRC (OR = 2.57, 95% CI, 1.42 -4.65), and their combinative effect showed a significant association with CRC (P = 0.04). CONCLUSION: MTR2756G allele may be a risk factor of CRC, and interaction may exsit between polymorphisms of MTHFRA1298C and MTRA2756G. Further studies with larger sample and in different ethnic groups are needed.


Asunto(s)
5-Metiltetrahidrofolato-Homocisteína S-Metiltransferasa/genética , Neoplasias Colorrectales/genética , Ferredoxina-NADP Reductasa/genética , Metilenotetrahidrofolato Reductasa (NADPH2)/genética , Polimorfismo Genético , Alelos , Estudios de Casos y Controles , Neoplasias Colorrectales/enzimología , Femenino , Frecuencia de los Genes , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción
15.
Zhonghua Yu Fang Yi Xue Za Zhi ; 40(1): 13-7, 2006 Jan.
Artículo en Zh | MEDLINE | ID: mdl-16620591

RESUMEN

OBJECTIVE: To investigate the association between CYP1A1, GSTM1, T1, UGT1A7 polymorphisms and colorectal cancer risk. METHODS: A case-control study of 140 patients with cancers and 343 health controls was conducted to investigate the role of CYP1A1, GSTM1, T1, UGT1A7 polymorphisms in colorectal cancer. Gene-gene interactions among CYP1A1, GSTM1, T1, UGT1A7 polymorphisms were detected by case-control study and case-only study. Genotypes of four genes polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and unconditional logistic regression was adopted to analyze the data. RESULTS: The CC, TC and CC genotypes of CYP1A1 T6235C significantly decreased the colorectal cancer risk as compared to TT genotype (OR = 0.493, 95% CI: 0.254-0.956, OR = 0.638, 95% CI: 0.427-0.952). GSTM1 and GSTT1 null genotype had no significant association with the increased risk of colorectal cancer while the mutant variants of UGT1A7 might increase the risk of colorectal cancer significantly (OR = 2.501, 95% CI: 1.456-4.296). The CORvalue for the gene-gene interactions between CYP1A1 variant and the null genotype of GSTT1, GSTM1-deleted and GSTT1-deleted genotype in the case-only design were 2.617 (95% CI: 1.015-6.752) and 3.935 (95% CI: 1.323-11.706), respectively. There was no significant interaction between CYP1A1 and GSTM1, CYP1A1 and UGT1A7. CONCLUSION: This study suggests that CYP1A1 and UGT1A7 variants might be associated with colorectal cancer. CYP1A1 and GSTM1 might interact on GSTT1 to influence the risk of colorectal cancer.


Asunto(s)
Neoplasias Colorrectales/genética , Predisposición Genética a la Enfermedad/genética , Polimorfismo de Nucleótido Simple , Estudios de Cohortes , Citocromo P-450 CYP1A1/genética , Estudios de Seguimiento , Frecuencia de los Genes , Genotipo , Glutatión Transferasa/genética , Humanos , Modelos Logísticos , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción
16.
World J Gastroenterol ; 11(3): 331-5, 2005 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-15637738

RESUMEN

AIM: To clarify the influence of genetic polymorphisms on colorectal cancer. METHODS: The results of 42 related studies from 1990 to 2001 were analyzed by meta-analysis. Mantel-Haenzel fixed-effect model or Dersimonian-Laird random-effect model and ReviewManager 4.1 statistical program were applied in processing the data. RESULTS: Meta analysis of these studies showed that GSTT1 deletion (pooled OR = 1.42), N-acetyltransferase 2 (NAT2)-rapid acetylator phenotype and genotye (pooled OR = 1.08) and NAT2-rapid acetylator phenotype (pooled OR = 1.15) had a significantly increased risk for colorectal cancer (P<0.05), other genotypes like GSTM1 deletion, GSTP1 1le105Val, NAT1*10, NAT2-rapid acetylator genotype CYP1A1 L1e462Val, CYP1A1 MspI*C, MTHFR C677T and MTR A2759G had no significant relationship with colorectal cancer (P>0.05). CONCLUSION: Risks for colorectal cancer are significantly associated with the genetic polymorphisms of GSTT1 deletion, NAT2-rapid acetylator phenotype and genotye and NAT2-rapid acetylator phenotype.


Asunto(s)
Arilamina N-Acetiltransferasa/genética , Neoplasias Colorrectales/genética , Eliminación de Gen , Predisposición Genética a la Enfermedad , Glutatión Transferasa/genética , Polimorfismo Genético , Genotipo , Humanos , Fenotipo
17.
Zhonghua Zhong Liu Za Zhi ; 26(11): 645-8, 2004 Nov.
Artículo en Zh | MEDLINE | ID: mdl-15777499

RESUMEN

OBJECTIVE: To evaluate the associations between genetic polymorphisms of glutathione S-transferase M1 and T1 (GSTM1 and GSTT1), smoking and susceptibility to colorectal cancer. METHODS: A case-control study of 126 patients and 343 healthy controls was conducted to investigate the role of GSTM1 and GSTT1 polymorphisms in colorectal cancer. Genotypes of GSTM1 and GSTT1 polymorphisms were analyzed by multiplex allele-specific polymerase chain reaction (PCR). RESULTS: The frequencies of GSTM1 null and GSTT1 null genotypes were 55.5% and 20.4%, respectively. After adjustment for age and sex, among those with GSTT1 null genotype, the GSTM1 null genotype had a significant increased risk of rectal cancers compared to GSTM1 non-null genotype (OR=9.74, 95% CI, 1.13 - 83.85). A 2.22-fold risk of colon cancers was associated with GSTM1 null genotype compared to GSTM1 non-null genotype among current smokers (P >0.05). Individuals with GSTT1 null genotype and currently smoking had a significant risk of colon cancers (OR = 4.55, 95% CI, 1.14 - 18.17), and rectal cancers (OR = 4.60, 95% CI, 1.11 - 19.11). CONCLUSION: This study suggests that certain null GSTM1 and GSTT1 genotypes may be associated with an elevated risk of colorectal cancer which may be modified by interaction of the two genetic polymorphisms and cigarette smoking.


Asunto(s)
Neoplasias del Colon/genética , Glutatión Transferasa/genética , Neoplasias del Recto/genética , Fumar/efectos adversos , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Neoplasias del Colon/enzimología , Femenino , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Polimorfismo Genético , Neoplasias del Recto/enzimología , Factores de Riesgo
18.
Zhonghua Yu Fang Yi Xue Za Zhi ; 38(3): 162-6, 2004 May.
Artículo en Zh | MEDLINE | ID: mdl-15182482

RESUMEN

OBJECTIVE: To investigate PstI allelic variants of cytochrome P450 2E1 (CYP2E1), the interaction effect on salted food and their role in risk for colorectal cancer. METHODS: The genotypes of CYP2E1 PstI restriction fragment length polymorphism were analyzed in 126 colorectal cancer cases and 343 normal controls. The unconditional logistic regression was applied to estimate the OR and its 95% CI. RESULTS: The CYP2E1 C1/C1, C1/C2 and C2/C2 genotypes were found respectively in 61.8%, 35.8% and 2.4% of normal control, similar to rectal cancer cases. The percentage of PstI variant genotype (54.9%: 52.9% C1/C2 and 2.0% C2/C2) in colon cancer cases was significantly higher than that in controls (adjusted OR1.979, 95% CI 1.090 approximately 3.595). Stratified analysis suggested an interaction between CYP2E1 C2 allele and salted food. The odds ratio (OR) for the CYP2E1 variant genotype, salted food eaten weekly or biweekly and eaten every day or every other day were 1.935, 2.122 and 2.315, respectively, while those of salted food combined with variant genotype eaten weekly or biweekly and eaten every day or every other day were 2.272 and 3.127. The role in risk for rectal cancer was different from that for colon cancer. Whatever the CYP2E1 genotype is, the risk for rectal cancer came to marked when salted food was consumed weekly or biweekly (OR = 2.646 and 2.297, respectively). However, none but the combined effect of variant genotype and salted food eaten every day or every other day had the notably risk for colon cancer and the odds ratio suddenly increased to 4.262 (95% CI 1.395 approximately 13.017), 1.69-fold higher than that of wild genotype (P = 0.072). CONCLUSION: The CYP2E1 C2 allele is a susceptibility factor for colorectal cancer, especially for colon cancer, and there is an apparent gene-environment interaction between the susceptible genotype and salted food.


Asunto(s)
Neoplasias Colorrectales/genética , Citocromo P-450 CYP2E1/genética , Conservación de Alimentos , Predisposición Genética a la Enfermedad , Alelos , Estudios de Casos y Controles , China/epidemiología , Neoplasias Colorrectales/epidemiología , Femenino , Genotipo , Humanos , Masculino , Epidemiología Molecular , Polimorfismo de Longitud del Fragmento de Restricción , Factores de Riesgo , Sales (Química)
19.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 33(5): 411-5, 2004 09.
Artículo en Zh | MEDLINE | ID: mdl-15476324

RESUMEN

OBJECTIVE: To understand the incidence of colorectal cancer in population drinking or not and to validate the relationship between drinking and colorectal cancer. METHODS: The data obtained from a questionnaire used in a population-based prospective screenings study in ten countries of Jiashan County was examined. A total of 64,102 men and women aged 30 y and older without history of cancer at baseline and a subcohort of 29,044 of them drinking past and current was conducted. Cox regression model was applied to estimate relative risk (RR). RESULTS: After 10 years follow-up,107 colon cancer and 135 rectal cancer cases were identified. Among drinkers and abstainers, the incidence density of colorectal cancer was 36.18 per 100 thousand and 37.26 per 100 thousand, respectively and there wasn't statistical significance(Z=0.52, P>0.05); The crude RR (95%CI) for drinker compared with never drinkers was 0.97(0.75 approximately 1.25), and the multivariable-adjusted RR (95%CI) was 1.13(0.87 approximately 1.48). The research power of this study was 96.99%. CONCLUSION: Alcohol drinking isn't one of the risk factors of colorectal cancer among Jiashan County population.


Asunto(s)
Consumo de Bebidas Alcohólicas/efectos adversos , Neoplasias Colorrectales/epidemiología , Neoplasias Colorrectales/etiología , Adulto , China/epidemiología , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Masculino , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Factores de Riesgo , Encuestas y Cuestionarios
20.
Environ Sci Technol ; 44(13): 5188-94, 2010 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-20455569

RESUMEN

Blood plasma samples (n = 43) collected retrospectively from New York State employees and National Guard personnel who had been assigned to work in the vicinity of the World Trade Center (WTC) during the week after the collapse of the buildings were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), and polychlorinated naphthalenes (PCNs). On the basis of algorithms developed to rank individual exposures to dust and debris and to smoke, we categorized the samples as: more smoke exposure (MSE), more dust exposure (MDE), less smoke exposure (LSE), and less dust exposure (LDE). Mean concentrations of PCDDs were 1070, 223, 3690, and 732 pg/g lipid wt, and mean concentrations of PCDFs were 910, 1520, 230, and 117 pg/g lipid wt, for the MSE, MDE, LSE, and LDE groups, respectively. The concentrations of PCDFs were higher in the two "more exposure" groups than in the two "less exposure" groups. Calculated TEQ concentrations of coplanar PCBs and PCDD/Fs in plasma samples were, on average, 1.12 and 41.2 pg WHO-TEQ/g lipid wt, respectively. TEQ concentrations of PCDFs were higher than those of PCDDs in both "more exposure" groups but lower than those of PCDDs in "less exposure" groups. This result is suggestive of exposure of the WTC responders to PCDFs after the WTC collapse. PCDFs contributed the majority of TEQs and are therefore the critical dioxin-like compounds in MSE/MDE groups, whereas PCDDs are the critical compounds in the LSE/LDE groups.


Asunto(s)
Benzofuranos/sangre , Naftalenos/sangre , Exposición Profesional , Bifenilos Policlorados/sangre , Dibenzodioxinas Policloradas/análogos & derivados , Dibenzofuranos Policlorados , Auxiliares de Urgencia , Exposición a Riesgos Ambientales/estadística & datos numéricos , Monitoreo del Ambiente/métodos , Humanos , Ciudad de Nueva York , Dibenzodioxinas Policloradas/sangre , Trabajo de Rescate , Ataques Terroristas del 11 de Septiembre
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