Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 96
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
J Allergy Clin Immunol ; 153(2): 447-460.e9, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37922997

RESUMO

BACKGROUND: Whether IgE affects eosinophil migration in chronic rhinosinusitis with nasal polyps (CRSwNP) remains largely unclear. Moreover, our understanding of local IgE, eosinophils, and omalizumab efficacy in CRSwNP remains limited. OBJECTIVE: We investigated whether IgE acts directly on eosinophils and determined its role in omalizumab therapy. METHODS: Eosinophils and their surface receptors were detected by hematoxylin and eosin staining and flow cytometry. IgE and its receptors, eosinophil peroxidase (EPX), eosinophilic cationic protein, and CCR3 were detected by immunohistochemistry and immunofluorescence. Functional analyses were performed on blood eosinophils and polyp tissues. Logistic regression was performed to screen for risk factors. Receiver operating characteristic curve was generated to evaluate the accuracy. RESULTS: Both FcεRI and CD23 were expressed on eosinophils. The expression of FcεRI and CD23 on eosinophil in nasal polyp tissue was higher than in peripheral blood (both P < .001). IgE and EPX colocalized in CRSwNP. IgE directly promoted eosinophil migration by upregulating CCR3 in CRSwNP but not in healthy controls. Omalizumab and lumiliximab were found to be effective in restraining this migration, indicating CD23 was involved in IgE-induced eosinophil migration. Both IgE+ and EPX+ cells were significantly reduced after omalizumab treatment in those who experienced response (IgE+ cells, P = .001; EPX+ cells, P = .016) but not in those with no response (IgE+ cells, P = .060; EPX+ cells, P = .151). Baseline IgE+ cell levels were higher in those with response compared to those without response (P = .024). The baseline local IgE+ cell count predicted omalizumab efficacy with an accuracy of 0.811. CONCLUSIONS: IgE directly promotes eosinophil migration, and baseline local IgE+ cell counts are predictive of omalizumab efficacy in CRSwNP.


Assuntos
Pólipos Nasais , Rinite , Rinossinusite , Humanos , Eosinófilos , Omalizumab/farmacologia , Omalizumab/uso terapêutico , Pólipos Nasais/tratamento farmacológico , Pólipos Nasais/metabolismo , Imunoglobulina E , Doença Crônica , Rinite/tratamento farmacológico , Rinite/metabolismo , Receptores CCR3
2.
J Org Chem ; 88(9): 5752-5759, 2023 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-37083480

RESUMO

The asymmetric C-H bond functionalization reaction is one of the most efficient and straightforward methods for the synthesis of optically active molecules. Herein, our work discovered a Pd-catalyzed asymmetric oxidative C-H/C-H cross-coupling reaction of ferrocenes with azoles such as oxazoles and thiazoles. Mono-N-protected amino acid as chiral ligands with palladium(II) has been demonstrated as an effective catalytic system in a weakly azine-directed asymmetric C-H bond functionalization reaction. This method offers a powerful strategy for constructing various substituted planar chiral ferrocenes via a dual C-H bond activation pathway in medium yields (up to 70%) with good enantioselectivity (up to 95.3:4.7 er) under mild conditions.

3.
Org Biomol Chem ; 21(18): 3794-3799, 2023 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-37071390

RESUMO

By the deaminative coupling reaction of α-aminoesters and α-aminoacetonitriles with thiols, a new strategy for the synthesis of α-thioaryl esters and nitriles is described, representing an example of converting C(sp3)-N into C(sp3)-S bonds. The substrates form diazo compounds in situ in the presence of NaNO2, and then a transition-metal-free S-H bond insertion reaction occurs with thiophenol derivatives. The method is simple in operation and post-treatment and has good universality. The corresponding thioethers were obtained in moderate to good (up to 90%) yields under mild conditions.

4.
Ren Fail ; 45(1): 2188966, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37563795

RESUMO

BACKGROUND: Renal dysfunction and disruption of renal endothelial glycocalyx are two important events during septic acute kidney injury (AKI). Here, the role and mechanism of hyaluronidase 1 (HYAL1) in regulating renal injury and renal endothelial glycocalyx breakdown in septic AKI were explored for the first time. METHODS: BALB/c mice were injected with lipopolysaccharide (LPS, 10 mg/kg) to induce AKI. HYAL1 was blocked in vivo using lentivirus-mediated short hairpin RNA targeting HYAL1 (LV-sh-HYAL1). Biochemical assays were performed to measure the levels and concentrations of biochemical parameters associated with AKI as well as levels of inflammatory cytokines. Renal pathological lesions were determined by hematoxylin-eosin (HE) staining. Cell apoptosis in the kidney was detected using terminal-deoxynucleoitidyl transferase-mediated nick end labeling (TUNEL) assay. Immunofluorescence and immunohistochemical (IHC) staining assays were used to examine the levels of hyaluronic acid in the kidney. The protein levels of adenosine monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) signaling, endothelial glycocalyx, and autophagy-associated indicators were assessed by western blotting. RESULTS: The knockdown of HYAL1 in LPS-subjected mice by LV-sh-HYAL1 significantly reduced renal inflammation, oxidative stress, apoptosis and kidney dysfunction in AKI, as well as alleviated renal endothelial glycocalyx disruption by preventing the release of hyaluronic acid to the bloodstream. Additionally, autophagy-related protein analysis indicated that knockdown of HYAL1 significantly enhanced autophagy in LPS mice. Furthermore, the beneficial actions of HYAL1 blockade were closely associated with the AMPK/mTOR signaling. CONCLUSION: HYAL1 deficiency attenuates LPS-triggered renal injury and endothelial glycocalyx breakdown in septic AKI in mice.


Assuntos
Injúria Renal Aguda , Hialuronoglucosaminidase , Animais , Camundongos , Injúria Renal Aguda/patologia , Proteínas Quinases Ativadas por AMP , Apoptose , Glicocálix/metabolismo , Glicocálix/patologia , Ácido Hialurônico , Hialuronoglucosaminidase/genética , Rim/patologia , Lipopolissacarídeos , Serina-Treonina Quinases TOR , Camundongos Endogâmicos BALB C
5.
Angew Chem Int Ed Engl ; 62(44): e202310132, 2023 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-37713281

RESUMO

Coupled electron/ion transport is a decisive feature of Li plating/stripping, wherein the compatibility of electron/ion transport rates determines the morphology of deposited Li. Local Li+ hotspots form due to inhomogeneous interfacial charge transfer and lead to uncontrolled Li deposition, which decreases the Li utilization rate and safety of Li metal anodes. Herein, we report a method to obtain dendrite-free Li metal anodes by driving electron pumping and accumulating and boosting Li ion diffusion by tuning the work function of a carbon host using cobalt-containing catalysts. The results reveal that increasing the work function provides an electron deviation from C to Co, and electron-rich Co shows favorable binding to Li+ . The Co catalysts boost Li+ diffusion on the carbon fiber scaffolds without local aggregation by reducing the Li+ migration barrier. The as-obtained dendrite-free Li metal anode exhibits a Coulombic efficiency of 99.0 %, a cycle life of over 2000 h, a Li utilization rate of 50 %, and a capacity retention of 83.4 % after 130 cycles in pouch cells at a negative/positive capacity ratio of 2.5. These findings provide a novel strategy to stabilize Li metal by regulating the work function of materials using electrocatalysts.

6.
J Org Chem ; 87(1): 479-487, 2022 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-34913339

RESUMO

A palladium(II)-catalyzed enantioselective oxidative cross-coupling of ferrocenes with heteroarenes is described. Mono-N-protected amino acids can be used as sources of chirality. With azine as an efficient directing group, various substituted planar chiral ferrocenes were obtained via a dual C-H bond activation pathway in medium yields (up to 72%) with good enantioselectivity (up to 89.4:10.6 er) under mild conditions.


Assuntos
Estresse Oxidativo , Paládio , Catálise , Metalocenos , Estereoisomerismo
7.
J Am Chem Soc ; 143(9): 3280-3283, 2021 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-33645987

RESUMO

Biomass-derived carbon materials prepared via pyrolysis from natural wood structures show potential for a storage application. Natural wood is composed of multiple carbon sources, including lignin, hemicellulose, and cellulose, which influence the formation and microstructure of pyrolysis carbon. However, the mechanism is not fully understood. In this work, vast lignin is selectively consumed via biodegradation with fungi from basswood. The results demonstrate that the as-prepared carbon material has a short-range ordered graphitic structure after thermal treatment. The improved graphitization degree of carbon suggests that cellulose is beneficial to graphite formation during pyrolysis. The elevated graphitization degree helps to improve the charge transfer and the thermodynamic stability of the electrode reaction. As a proof of concept, the obtained carbon current collector as a sodium-metal anode can undergo cycling at an areal capacity of 10 mAh cm-2 for over 4500 h and yield an excellent Coulombic efficiency of >99.5%.

8.
Environ Toxicol ; 36(7): 1389-1401, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33764603

RESUMO

Silica nanoparticles (SiNPs) as one of the most productive nano-powder, has been extensively applied in various fields. There has been increasing concern about the adverse effects of SiNPs on the health of ecological organisms and human. The potential cardiovascular toxicity of SiNPs and involved mechanisms remain elusive. Hence, in this study, we investigated the cardiovascular toxicity of SiNPs (60 nm) and explored the underlying mechanisms using H9c2 cardiomyocytes. Results showed that SiNPs induced oxidative stress and activated the Nrf2/HO-1 antioxidant pathway. Autophagy was also activated by SiNPs. Interestingly, N-acetyl-L-cysteine (NAC)attenuated autophagy after inhibiting reactive oxygen species (ROS). Meanwhile, down-regulation of Nrf2 enhanced autophagy. In summary, these data indicated that SiNPs induce autophagy in H9c2 cardiomyocytes through oxidative stress, and the Nrf2/HO-1 pathway has a negative regulatory effect on autophagy. This study provides new evidence for the cardiovascular toxicity of SiNPs and provides a reference for the safe use of nanomaterials in the future.


Assuntos
Nanopartículas , Dióxido de Silício , Autofagia , Humanos , Fator 2 Relacionado a NF-E2/genética , Nanopartículas/toxicidade , Estresse Oxidativo , Espécies Reativas de Oxigênio , Transdução de Sinais , Dióxido de Silício/toxicidade
9.
Angew Chem Int Ed Engl ; 60(48): 25508-25513, 2021 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-34580988

RESUMO

The plating/stripping of Li dendrites can fracture the static solid electrolyte interphase (SEI) and cause significant dynamic volume variations in the Li anode, which give rise to poor cyclability and severe safety hazards. Herein, a tough polymer with a slide-ring structure was designed as a self-adaptive interfacial layer for Li anodes. The slide-ring polymer with a dynamically crosslinked network moves freely while maintaining its toughness and fracture resistance, which allows it can to dissipate the tension induced by Li dendrites on the interphase layer. Moreover, the slide-ring polymer is highly stretchable, elastic, and displays an ultrafast self-healing ability, which allows even pulverized Li to remain coalesced without disintegrating upon consecutive cycling. The Li anodes demonstrate greatly improved suppression of Li dendrite formation, as evidenced by the high critical current density (6 mA cm-2 ) and stable cycling for the full cells with high-areal capacity LiFePO4 , high-voltage NCM, and S cathodes.

10.
Anal Chem ; 92(6): 4535-4540, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32052626

RESUMO

The development of switches responding to specific pH changes was particularly useful in wide application fields. Owing to flexible switches simulated by pH, i-motif DNAs are widely used as a pH sensor. But its character of structure transition strongly dependent on acidic pH severely hampers the application of i-motif DNA in physiological media. Herein, we report the stable i-motif structure formed at a physiological pH triggered by spatial confinement of silica nanochannels. Three classic DNA chains containing 21-mer i-motif domain base-pairs and a single-stranded multiply (T)n spacer, 5'-COOH-(T)n-CCCTAACCCTAACCCTAACCC-3', were employed to evaluate the enhanced stability of i-motif structure. Compared to their free states in a dilute solution, the transition pH of all i-motif DNAs decorated in nanochannels remarkably shifts toward a neutral pH. Moreover, the transition midpoint can be tuned sensitively over the physiologically relevant pH range through slightly varying the length of T base spacer. Density functional theory (DFT) calculations validate that the increased proton density in a nanochannel triggers the formation of an i-motif structure under a neutral pH. Finally, this i-motif DNA based nanochannels electrode was successfully employed to monitor pH in brain microdialysates followed by cerebral ischemia. The present approach is not limited by fundamental investigation for DNA conformation but may extend toward the manipulation of i-motif based structures for artificial molecular machines and signaling systems.


Assuntos
Técnicas Biossensoriais , Encéfalo/patologia , DNA/química , Técnicas Eletroquímicas , Microdiálise , Nanotecnologia , Animais , Isquemia Encefálica/diagnóstico , Teoria da Densidade Funcional , Concentração de Íons de Hidrogênio , Motivos de Nucleotídeos , Tamanho da Partícula , Ratos , Propriedades de Superfície
11.
Small ; 16(48): e2005184, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33169925

RESUMO

The development of efficient and stable noble-metal-free electrocatalysts for hydrogen evolution reaction (HER) in alkaline media is still a challenge. Herein, a hybrid material formed by the interconnection of Ni17 W3 intermetallic compound with metallic W is demonstrated for HER. The Ni17 W3 -W hybrid is prepared by the atmosphere- and thermal-induced phase-separation strategy from a single-phase precursor (NiWO4 ), which gives Ni17 W3 -W hybrid abundant and tight interfaces. The theoretical calculation manifests that Ni17 W3 shows more optimized energetics for adsorbed H atom, while W has lower energy barrier for water dissociation, and the synergistic effect between them is believed to facilitate the HER kinetics. Moreover, Ni17 W3 presents a proper adsorption strength for both adsorbed OH and H, and thus Ni17 W3 may also act as a high HER catalyst by itself. As a result, the Ni17 W3 -W hybrid demonstrates high activity and durability for HER in liquid alkaline electrolyte; the electrolyzer assembled by Ni17 W3 -W hybrid and Ni-Fe-layered double hydroxide (LDH) as, respectively, the cathode and anode electrocatalysts presents superior performance to Pt/C-IrO2 benchmark. In addition, the Ni17 W3 -W hybrid also works well in the water electrolyzer based on solid hydroxide exchange membrane. The present work provides a promising pathway to the design of high-performance electrocatalysts.

12.
Med Sci Monit ; 26: e920421, 2020 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-32467558

RESUMO

BACKGROUND The aim of this study was to evaluate the efficacy and safety of use of a ureteral catheter during arteriovenous fistula in end-stage renal disease patients with poor vascular status. MATERIAL AND METHODS Fifty patients with standard arteriovenous fistulas at Sir Run Run Hospital of Nanjing Medical University from April 2018 to April 2019 were included. Based on the use of ureteral catheter exploration and tourniquet hydraulic dilatation, patients were divided into study and control groups. The operative success rate, inner diameter of cephalic vein 1 day post-operatively, blood flow in the internal fistula, patency rate and blood flow in the internal fistula 3 months post-operatively, and complications 6 months post-operatively were compared between the 2 groups. RESULTS There were 25 cases in each group, with no significant differences in sex or age between the 2 groups. The operative success rate in the study group was higher than in the control group (96% vs. 88%) (F=1.087, P=0.297). The patency rates at 3 and 6 months post-operatively in the study group were higher than in the control group. The inner diameter of the cephalic vein 1 day post-operatively, the blood flow in the internal fistula, and the complications 6 months post-operatively in the study group were significantly superior to those of the control group (P=0.002). CONCLUSIONS In standard arteriovenous fistula, especially vascular catheter exploration of unhealthy vessels, the application of a ureteral catheter can improve the operative success rate and promote internal fistula maturity, with low cost and ease of use.


Assuntos
Falência Renal Crônica/terapia , Cateterismo Urinário/métodos , Cateteres Urinários/tendências , Adulto , Idoso , Fístula Arteriovenosa/cirurgia , Derivação Arteriovenosa Cirúrgica/métodos , Circulação Sanguínea , China , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Diálise Renal/métodos , Estudos Retrospectivos , Resultado do Tratamento , Grau de Desobstrução Vascular
13.
Ecotoxicol Environ Saf ; 192: 110316, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32061981

RESUMO

Mercury (Hg) re-emission from sediment is an important process in the biogeochemistry cycles of Hg in the aquatic ecosystem. The contribution of Hg released from sediment to water remains unclear for some shallow lakes. Lake Nansi is a typical shallow lake in northern China that is divided into upper and lower lakes by a dam. The Hg species in the water profile and sediment were measured from two sampling sites in the lake. Nansi Lake was not markedly contaminated by Hg. The Hg profile in the sediment indicated that the demand for energy and the policy management in the catchment influenced the Hg accumulation in its sediment. On the basis of Fick's first law and the sedimentation rate, the diffusion flux of dissolved Hg from sediment to overlying water and the accumulation flux were estimated. According to one-year scale estimation, approximately 10%-13% the Hg in the sediments can be re-released into the overlying water. The Hg diffused from the sediment accounted for 7.9%-16% of the Hg in the overlying water. These results of this study improve the understanding of the sources of pollution in water and enable researchers to focus on the contribution of sediment to the pollution of water in shallow lakes.


Assuntos
Sedimentos Geológicos/química , Lagos/química , Mercúrio/análise , Poluentes Químicos da Água/análise , China , Monitoramento Ambiental
14.
Small ; 15(7): e1804706, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30637951

RESUMO

Preventing the aggregation of nanosized electrode materials is a key point to fully utilize the advantage of the high capacity. In this work, a facile and low-cost surface solvation treatment is developed to synthesize Fe2 VO4 hierarchical porous microparticles, which efficiently prevents the aggregation of the Fe2 VO4 primary nanoparticles. The reaction between alcohol molecules and surface hydroxy groups is confirmed by density functional theory calculations and Fourier transform infrared spectroscopy. The electrochemical mechanism of Fe2 VO4 as lithium-ion battery anode is characterized by in situ X-ray diffraction for the first time. This electrode material is capable of delivering a high reversible discharge capacity of 799 mA h g-1 at 0.5 A g-1 with a high initial coulombic efficiency of 79%, and the capacity retention is 78% after 500 cycles. Moreover, a remarkable reversible discharge capacity of 679 mA h g-1 is achieved at 5 A g-1 . Furthermore, when tested as sodium-ion battery anode, a high reversible capacity of 382 mA h g-1 can be delivered at the current density of 1 A g-1 , which still retains at 229 mA h g-1 after 1000 cycles. The superior electrochemical performance makes it a potential anode material for high-rate and long-life lithium/sodium-ion batteries.

15.
Allergy ; 74(4): 720-730, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30353934

RESUMO

BACKGROUND: Chronic rhinitis (CR) is currently regarded as a syndrome, which presents as several endotypes. The aim of this study was to identify the CR endotype clusters and investigate the inflammatory patterns associated with the different endotypes. METHODS: A total of 259 CR patients and 20 control subjects were enrolled in this prospective study. Twelve clinical variables were analyzed using cluster analysis and five inflammatory variables were measured to investigate the inflammatory patterns associated with the different clusters. RESULTS: Six endotype clusters of CR were defined in the Chinese CR patients. Patients in cluster 1 (38.6%) were diagnosed as allergic rhinitis (AR) without asthma, and in cluster 2 (13.5%) as AR with asthma, with all demonstrating positive results for local eosinophils and high levels of local and serum IgE. Similarly, patients in cluster 3 (18.6%) were diagnosed as nonallergic rhinitis with eosinophilia syndrome (NARES) without asthma and in cluster 5 (5.0%) as NARES with asthma, with all demonstrating positive results for local eosinophils, and negative results for both local and serum IgE. Patients in cluster 4 (4.6%) were diagnosed as local allergic rhinitis and showed positive results for local eosinophils and local IgE, but negative results for serum IgE, whereas patients in cluster 6 (19.7%) were diagnosed as idiopathic rhinitis because of high symptoms scores, but negative findings for local eosinophils, local IgE, and serum IgE. CONCLUSIONS: Chinese CR patients may be clustered into six endotypes with different inflammatory patterns, which may help in delivering individualized treatment.


Assuntos
Asma/complicações , Análise por Conglomerados , Eosinofilia/etiologia , Inflamação/etiologia , Rinite/patologia , Adulto , Povo Asiático , Estudos de Casos e Controles , Contagem de Células , Doença Crônica , Eosinófilos/patologia , Feminino , Humanos , Imunoglobulina E/análise , Masculino , Rinite/classificação , Rinite/complicações , Rinite/diagnóstico
16.
Angew Chem Int Ed Engl ; 58(4): 1094-1099, 2019 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-30447094

RESUMO

The uncontrolled growth of Li dendrites upon cycling might result in low coulombic efficiency and severe safety hazards. Herein, a lithiophilic binary lithium-aluminum alloy layer, which was generated through an in situ electrochemical process, was utilized to guide the uniform metallic Li nucleation and growth, free from the formation of dendrites. Moreover, the formed LiAl alloy layer can function as a Li reservoir to compensate the irreversible Li loss, enabling long-term stability. The protected Li electrode shows superior cycling over 1700 h in a Li|Li symmetric cell.

17.
Biochem Biophys Res Commun ; 501(3): 688-695, 2018 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-29758198

RESUMO

Vascular remodeling is a characteristic pathological feature of hypertension, it can cause of increasing vascular resistance and decrease of compliance. Vascular smooth muscle cell (VSMCs) dysfunction is the important foundation of vascular remodeling. Increasing evidences have revealed that lncRNA is an important regulatory factor of VSMC function. In this paper, we explored the function of lncRNA TUG1 in vascular remodeling of hypertension. Here, we found that lncRNA TUG1 was highly expressed in aorta of spontaneously hypertensive rats (SHR) rats and promoted the proliferation and migration of VSMCs (SHR-VSMCs). Bioinformatics analyze showed that lncRNA TUG1 sequence had miR-145-5p binding sites. Luciferase reporter test, RNA pulldown and qRT-PCR showed that lncRNA TUG1 could bind miR-145-5p. Similarly, bioinformatics analyze found that FGF10 3 'UTR contained miR-145-5p binding sites. Luciferase reporter test, qRT-PCR and Western blot were shown that miR-145-5p inhibited FGF10 expression by binding to its 3 'UTR. MTT showed that miR-145-5p inhibited and FGF10 promoted SHR-VMSCs proliferation and migration. Overexpression of miR-145-5p or knocking down of FGF10 after overexpresion of lncRNA TUG1 could rescue the proliferation and migration promoted by lncRNA TUG1. LncRNA TUG1 and FGF10 promoted and miR-145-5p suppressed the expression of ß-catenin, TCF and LEF in SHR-VSMCs. Therefore, lncRNA TUG1/miR-145-5p/FGF10 promotes the proliferation and migration of VSMCs in hypertensive state by activating the Wnt/ß-catenin pathway.


Assuntos
Aorta/patologia , Fator 10 de Crescimento de Fibroblastos/genética , Regulação da Expressão Gênica , Hipertensão/genética , MicroRNAs/genética , Miócitos de Músculo Liso/patologia , RNA Longo não Codificante/genética , Animais , Aorta/citologia , Aorta/metabolismo , Movimento Celular , Proliferação de Células , Células Cultivadas , Hipertensão/patologia , Masculino , Miócitos de Músculo Liso/citologia , Miócitos de Músculo Liso/metabolismo , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Remodelação Vascular
19.
Environ Geochem Health ; 40(1): 115-125, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28251476

RESUMO

Nansi Lake is composed of four sub-lakes from north to south: Nanyang Lake, Dushan Lake, Zhaoyang Lake and Weishan Lake. An environmental pollution investigation was carried out to determine the fractionation, and pollution assessments of mercury (Hg) in surficial sediments from Nansi Lake. Results showed that the mean concentration of Hg was 3.1 times higher than its background value (0.015 mg kg-1), and the high concentration of Hg which even reached up to five times than the background value in the part of Dushan Lake and Weishan Lake, which indicated that there are obvious spatial differences. The content of Hg was positively correlated with that of total organic carbon, and negatively correlated with that of pH and SiO2 in surface sediments. An improved Tessier sequential extraction procedure was used to study the fractions of Hg in sediments. The results indicated that Hg existed primarily in the fraction of residual, which accounts for 58.4% of total mercury (THg), and the percentage of extractable Hg was only 1.93% of total mercury. High concentrations of mercury of non-residual phase were found in part lake area from the Nanyang Lake and the Weishan Lake, which indicating a higher potential ecological risk relative to the other lake areas. Based on the values of enrichment factor and geo-accumulation index, most part of Dushan Lake and Nanyang Lake and Weishan Lake were in a moderate pollution. And based on the fractionation of mercury, risk assessment code of Hg exhibited low risks to the environment in Nansi Lake.


Assuntos
Sedimentos Geológicos/química , Lagos , Mercúrio/análise , Poluentes Químicos da Água/análise , Carbono/análise , China , Concentração de Íons de Hidrogênio , Compostos Orgânicos/análise , Controle de Qualidade , Medição de Risco , Dióxido de Silício/análise
20.
J Am Chem Soc ; 139(11): 4123-4129, 2017 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-28215081

RESUMO

Indium-oxide (In2O3) nanobelts coated by a 5-nm-thick carbon layer provide an enhanced photocatalytic reduction of CO2 to CO and CH4, yielding CO and CH4 evolution rates of 126.6 and 27.9 µmol h-1, respectively, with water as reductant and Pt as co-catalyst. The carbon coat promotes the absorption of visible light, improves the separation of photoinduced electron-hole pairs, increases the chemisorption of CO2, makes more protons from water splitting participate in CO2 reduction, and thereby facilitates the photocatalytic reduction of CO2 to CO and CH4.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA