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1.
Theor Appl Genet ; 137(7): 162, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38884792

RESUMO

KEY MESSAGE: OsCOL5, an ortholog of Arabidopsis COL5, is involved in photoperiodic flowering and enhances rice yield through modulation of Ghd7 and Ehd2 and interactions with OsELF3-1 and OsELF3-2. Heading date, also known as flowering time, plays a crucial role in determining the adaptability and yield potential of rice (Oryza sativa L.). CONSTANS (CO)-like is one of the most critical flowering-associated gene families, members of which are evolutionarily conserved. Here, we report the molecular functional characterization of OsCOL5, an ortholog of Arabidopsis COL5, which is involved in photoperiodic flowering and influences rice yield. Structural analysis revealed that OsCOL5 is a typical member of CO-like family, containing two B-box domains and one CCT domain. Rice plants overexpressing OsCOL5 showed delayed heading and increases in plant height, main spike number, total grain number per plant, and yield per plant under both long-day (LD) and short-day (SD) conditions. Gene expression analysis indicated that OsCOL5 was primarily expressed in the leaves and stems with a diurnal rhythm expression pattern. RT-qPCR analysis of heading date genes showed that OsCOL5 suppressed flowering by up-regulating Ghd7 and down-regulating Ehd2, consequently reducing the expression of Ehd1, Hd3a, RFT1, OsMADS14, and OsMADS15. Yeast two-hybrid experiments showed direct interactions of OsCOL5 with OsELF3-1 and OsELF3-2. Further verification showed specific interactions between the zinc finger/B-box domain of OsCOL5 and the middle region of OsELF3-1 and OsELF3-2. Yeast one-hybrid assays revealed that OsCOL5 may bind to the CCACA motif. The results suggest that OsCOL5 functions as a floral repressor, playing a vital role in rice's photoperiodic flowering regulation. This gene shows potential in breeding programs aimed at improving rice yield by influencing the timing of flowering, which directly impacts crop productivity.


Assuntos
Flores , Regulação da Expressão Gênica de Plantas , Oryza , Fotoperíodo , Proteínas de Plantas , Oryza/genética , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Flores/crescimento & desenvolvimento , Flores/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento
2.
BMC Nephrol ; 25(1): 111, 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38515022

RESUMO

BACKGROUND: It is unclear whether short-term blood pressure variability (BPV) is associated with target organ damage in patients with non-dialysis chronic kidney disease (CKD). METHODS: A cross-sectional, single-center study was conducted among 3442 non-dialysis CKD patients hospitalized in the department of Nephrology of the Fifth Affiliated Hospital of Sun Yat-sen University from November 2017 to July 2022 and collected the demographic, laboratory, clinic blood pressure, ambulatory blood pressure data, and short-term BPV assessed by the weighted standard deviation (wSD) derived from ambulatory blood pressure monitoring (ABPM). Multivariate logistic analyses were used to evaluate the independent effects between short-term BPV and subclinical target organ damage, including left ventricular hypertrophy (LVH), abnormal carotid intima-media thickness (CIMT), low estimated glomerular filtration rate (eGFR), and albuminuria. RESULTS: The average age of the participants was 47.53 ± 14.06 years and 56% of participants were male. The baseline eGFR was 69 mL/min/1.73 m2. Based on the tertile distribution of wSD according to equal numbers, patients were divided into three categories with T1(< 9.66 mmHg), T2(9.66-12.23 mmHg), and T3(> 12.23 mmHg) of SBPV; T1(< 8.17 mmHg), T2(8.17-9.93 mmHg), and T3(> 9.93 mmHg) of DBPV. The participants with the higher wSD group had a higher prevalence of target organ damage than their counterparts (P-trend < 0.05). An increasing trend in short-term variability was present with advancing CKD stages (P-trend < 0.001). Multivariate logistic analyses results showed that the odds ratio (OR) of SBP wSD was (1.07 [1.03,1.11], P < 0.001) for LVH, (1.04 [1.01,1.07, P = 0.029) for abnormal CIMT, (1.05 [1.02,1.08], P = 0.002) for low eGFR, and (1.06 [1.02,1.09], P = 0.002) for albuminuria; The OR of DBP wSD was (1.07 [1.02,1.12], P = 0.005) for LVH, (1.05 [1.01,1.09], P = 0.028) for abnormal CIMT, (1.05 [1.01,1.09], P = 0.022) for low eGFR, and (1.05 [1.01,1.10], P = 0.025) for albuminuria when adjusted for confounding factors and mean BP. CONCLUSIONS: In conclusion, short-term BPV is associated with target organ damage, and irresponsible of average blood pressure levels, in Chinese non-dialysis CKD participants.


Assuntos
Hipertensão , Insuficiência Renal Crônica , Humanos , Masculino , Adulto , Pessoa de Meia-Idade , Feminino , Pressão Sanguínea , Hipertensão/complicações , Monitorização Ambulatorial da Pressão Arterial , Albuminúria/epidemiologia , Albuminúria/complicações , Estudos Transversais , Espessura Intima-Media Carotídea , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Hipertrofia Ventricular Esquerda/epidemiologia , Hipertrofia Ventricular Esquerda/complicações
3.
Theor Appl Genet ; 136(7): 160, 2023 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-37347301

RESUMO

KEY MESSAGE: TAC1 is involved in photoperiodic and gravitropic responses to modulate rice dynamic plant architecture likely by affecting endogenous auxin distribution, which could explain TAC1 widespread distribution in indica rice. Plants experience a changing environment throughout their growth, which requires dynamic adjustments of plant architecture in response to these environmental cues. Our previous study demonstrated that Tiller Angle Control 1 (TAC1) modulates dynamic changes in plant architecture in rice; however, the underlying regulatory mechanisms remain largely unknown. In this study, we show that TAC1 regulates plant architecture in an expression dose-dependent manner, is highly expressed in stems, and exhibits dynamic expression in tiller bases during the growth period. Photoperiodic treatments revealed that TAC1 expression shows circadian rhythm and is more abundant during the dark period than during the light period and under short-day conditions than under long-day conditions. Therefore, it contributes to dynamic plant architecture under long-day conditions and loose plant architecture under short-day conditions. Gravity treatments showed that TAC1 is induced by gravistimulation and negatively regulates shoot gravitropism, likely by affecting auxin distribution. Notably, the tested indica rice containing TAC1 displayed dynamic plant architecture under natural long-day conditions, likely explaining the widespread distribution of TAC1 in indica rice. Our results provide new insights into TAC1-mediated regulatory mechanisms for dynamic changes in rice plant architecture.


Assuntos
Oryza , Proteínas de Plantas , Proteínas de Plantas/genética , Fotoperíodo , Gravitação , Ácidos Indolacéticos/metabolismo , Regulação da Expressão Gênica de Plantas
4.
AIDS ; 35(6): 851-860, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33587447

RESUMO

OBJECTIVE: Despite successful antiviral therapy, the recovery of CD4+ T cells may not be complete in certain HIV-1-infected individuals. In our previous work with humanized mice infected with CXCR4-tropic HIV-1LAI (LAI), viral protein Nef was found the major factor determining rapid loss of both CD4+ T cells and CD4+CD8+ thymocytes but its effect on early T-cell development is unknown. The objective of this study is to investigate the influence of LAI Nef on the development of hematopoietic stem/progenitor cells (HSPCs) into T lymphoid cells. DESIGN: HSPC-OP9-DL1 cell co-culture and humanized mouse model was used to investigate the objective of our study in vitro and in vivo. RNA-seq was exploited to study the change of gene expression signature after nef expression in HSPCs. RESULTS: Nef expression in HSPCs was found to block their development into T lymphoid cells both in vitro and in the mice reconstituted with nef-expressing HSPCs derived from human cord blood. More surprisingly, in humanized mice nef expression preferentially suppressed the production of CD4+ T cells. This developmental defect was not the result of CD34+ cell loss. RNA-seq analysis revealed that Nef affected the expression of 176 genes in HSPCs, including those involved in tumor necrosis factor, Toll-like receptor, and nucleotide-binding oligomerization domain-like receptor signaling pathways that are important for hematopoietic cell development. CONCLUSION: Our results demonstrate that Nef compromises the development of HSPCs into T lymphoid cells, especially CD4+ T cells. This observation suggests that therapeutics targeting Nef may correct HIV-1-associated hematopoietic abnormalities, especially defects in T-cell development.


Assuntos
Infecções por HIV , HIV-1 , Transplante de Células-Tronco Hematopoéticas , Animais , Linfócitos T CD4-Positivos , Camundongos , Produtos do Gene nef do Vírus da Imunodeficiência Humana
5.
Sci Adv ; 5(2): eaau6852, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30746487

RESUMO

Carbon fibers have high surface areas and rich functionalities for interacting with ions, molecules, and particles. However, the control over their porosity remains challenging. Conventional syntheses rely on blending polyacrylonitrile with sacrificial additives, which macrophase-separate and result in poorly controlled pores after pyrolysis. Here, we use block copolymer microphase separation, a fundamentally disparate approach to synthesizing porous carbon fibers (PCFs) with well-controlled mesopores (~10 nm) and micropores (~0.5 nm). Without infiltrating any carbon precursors or dopants, poly(acrylonitrile-block-methyl methacrylate) is directly converted to nitrogen and oxygen dual-doped PCFs. Owing to the interconnected network and the highly optimal bimodal pores, PCFs exhibit substantially reduced ion transport resistance and an ultrahigh capacitance of 66 µF cm-2 (6.6 times that of activated carbon). The approach of using block copolymer precursors revolutionizes the synthesis of PCFs. The advanced electrochemical properties signify that PCFs represent a new platform material for electrochemical energy storage.

6.
Nat Commun ; 10(1): 675, 2019 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-30737399

RESUMO

High mass loading and fast charge transport are two crucial but often mutually exclusive characteristics of pseudocapacitors. On conventional carbon supports, high mass loadings inevitably lead to sluggish electron conduction and ion diffusion due to thick pseudocapacitive layers and clogged pores. Here we present a design principle of carbon supports, utilizing self-assembly and microphase-separation of block copolymers. We synthesize porous carbon fibers (PCFs) with uniform mesopores of 11.7 nm, which are partially filled with MnO2 of <2 nm in thickness. The uniform mesopores and ultrathin MnO2 enable fast electron/ion transport comparable to electrical-double-layer-capacitive carbons. At mass loadings approaching 7 mg cm-2, the gravimetric and areal capacitances of MnO2 (~50% of total mass) reach 1148 F g-1 and 3141 mF cm-2, respectively. Our MnO2-coated PCFs outperform other MnO2-based electrodes at similar loadings, highlighting the great promise of block copolymers for designing PCF supports for electrochemical applications.

7.
Small ; 13(43)2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28902982

RESUMO

Herein, a poly(vinylpyrrolidone) (PVP)-free method is described for synthesizing Ag nanoplates that have localized surface plasmon resonance in the near-infrared (NIR) range. Citrate-capped Ag spherical nanoparticles are first grown into small Ag nanoplates that resonate in the range of 500-800 nm. The small Ag nanoplates are used as seeds to further grow into large Ag nanoplates with a lateral dimension of 100-600 nm and a plasmon resonance wavelength of 800-1660 nm and above. The number of growth steps can be increased as desired. Without introducing additional citrate into the solutions of small Ag nanoplate seeds, large Ag nanoplates can be synthesized within minutes. The entire synthesis is completely PVP free, which promotes the nanoparticle growth along the lateral direction to form large Ag nanoplates. The multistep growth and the minimum usage of citrate are essential for the fast growth of high-aspect-ratio Ag nanoplates resonating in the NIR range.

8.
Sci Rep ; 7(1): 1440, 2017 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-28469142

RESUMO

A hierarchical mesoporous carbon foam (ECF) with an interconnected micro-/mesoporous architecture was prepared and used as a binder-free, low-cost, high-performance anode for lithium ion batteries. Due to its high specific surface area (980.6 m2/g), high porosity (99.6%), light weight (5 mg/cm3) and narrow pore size distribution (~2 to 5 nm), the ECF anode exhibited a high reversible specific capacity of 455 mAh/g. Experimental results also demonstrated that the anode thickness significantly influence the specific capacity of the battery. Meanwhile, the ECF anode retained a high rate performance and an excellent cycling performance approaching 100% of its initial capacity over 300 cycles at 0.1 A/g. In addition, no binders, carbon additives or current collectors are added to the ECF based cells that will increase the total weight of devices. The high electrochemical performance was mainly attributed to the combined favorable hierarchical structures which can facilitate the Li+ accessibility and also enable the fast diffusion of electron into the electrode during the charge and discharge process. The synthesis process used to make this elastic carbon foam is readily scalable to industrial applications in energy storage devices such as li-ion battery and supercapacitor.

9.
Small ; 13(15)2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28151575

RESUMO

Herein an approach to controlling the pore size of mesoporous carbon thin films from metal-free polyacrylonitrile-containing block copolymers is described. A high-molecular-weight poly(acrylonitrile-block-methyl methacrylate) (PAN-b-PMMA) is synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. The authors systematically investigate the self-assembly behavior of PAN-b-PMMA thin films during thermal and solvent annealing, as well as the pore size of mesoporous carbon thin films after pyrolysis. The as-spin-coated PAN-b-PMMA is microphase-separated into uniformly spaced globular nanostructures, and these globular nanostructures evolve into various morphologies after thermal or solvent annealing. Surprisingly, through thermal annealing and subsequent pyrolysis of PAN-b-PMMA into mesoporous carbon thin films, the pore size and center-to-center spacing increase significantly with thermal annealing temperature, different from most block copolymers. In addition, the choice of solvent in solvent annealing strongly influences the block copolymer nanostructure and the pore size of mesoporous carbon thin films. The discoveries herein provide a simple strategy to control the pore size of mesoporous carbon thin films by tuning thermal or solvent annealing conditions, instead of synthesizing a series of block copolymers of various molecular weights and compositions.

10.
Toxicol Lett ; 262: 153-160, 2016 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-27720909

RESUMO

Mercury sulfides (α-HgS, ß-HgS) are frequently included in traditional medicines. Mercury is known for nephrotoxicity, their safety is of concern. To address this question, mice were orally administrated with Zuotai (54% ß-HgS, 30mg/kg), α-HgS (HgS, 30mg/kg), HgCl2 (33.6mg/kg), or MeHgCl (3.1mg/kg) for 7days, and nephrotoxicity was examined. Animal body weights were decreased by HgCl2 and to a lesser extent by MeHg, but unaltered after Zuotai and HgS. HgCl2 and MeHg produced renal tubular vacuolation, interstitial inflammation and cell degeneration with protein cysts in the tubular lumen, while these pathological lesions were mild in Zuotai and HgS-treated mice. Electron microscopy showed that HgCl2 and MeHg produced spotted swelling endothelium reticulum, while these lesions were mild or absent in Zuotai and HgS-treated mice. Renal Hg contents reached 250-300ng/mg kidney in HgCl2 and MeHg groups as compared to 2-3ng/mg in Zuotai and HgS groups. The expression of kidney injury biomarkers, kidney injury molecule-1 (Kim-1) and neutrophil gelatinase-associated lipocalin (Ngal), were increased after HgCl2 and MeHg, but unaltered after Zuotai and HgS. The expression of renal influx transporters Oat3 and Oatp4c1 was decreased, while the expression of renal efflux transporter such as Mrp2, Mrp4, and Mate2 was increased following HgCl2 and MeHg. These gene expressions were unchanged after Zuotai and HgS. In summary, both α-HgS and ß-HgS are less nephrotoxic than HgCl2 and MeHg, indicating that chemical forms of mercury are a major determinant of mercury disposition and toxicity.


Assuntos
Nefropatias/induzido quimicamente , Cloreto de Mercúrio/toxicidade , Compostos de Mercúrio/toxicidade , Compostos de Metilmercúrio/toxicidade , Injúria Renal Aguda/patologia , Animais , Biomarcadores , Peso Corporal/efeitos dos fármacos , Proteínas de Transporte/metabolismo , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/patologia , Receptor Celular 1 do Vírus da Hepatite A/metabolismo , Rim/metabolismo , Nefropatias/patologia , Túbulos Renais/patologia , Lipocalina-2/metabolismo , Mercúrio/metabolismo , Camundongos , Tamanho do Órgão/efeitos dos fármacos
11.
Regul Toxicol Pharmacol ; 78: 1-7, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27032305

RESUMO

Zuotai is composed mainly of ß-HgS, while cinnabar mainly contains α-HgS. Both forms of HgS are used in traditional medicines and their safety is of concern. This study aimed to compare the hepatotoxicity potential of Zuotai and α-HgS with mercury chloride (HgCl2) and methylmercury (MeHg) in mice. Mice were orally administrated with Zuotai (30 mg/kg), α-HgS (HgS, 30 mg/kg), HgCl2 (33.6 mg/kg), or CH3HgCl (3.1 mg/kg) for 7 days, and liver injury and gene expressions related to toxicity, inflammation and Nrf2 were examined. Animal body weights were decreased by HgCl2 and to a less extent by MeHg. HgCl2 and MeHg produced spotted hepatocyte swelling and inflammation, while such lesions are mild in Zuotai and HgS-treated mice. Liver Hg contents reached 45-70 ng/mg in HgCl2 and MeHg groups; but only 1-2 ng/mg in Zuotai and HgS groups. HgCl2 and MeHg increased the expression of liver injury biomarker genes metallothionein-1 (MT-1) and heme oxygenase-1 (HO-1); the inflammation biomarkers early growth response gene (Egr1), glutathione S-transferase (Gst-mu), chemokine (mKC) and microphage inflammatory protein (MIP-2), while these changes were insignificant in Zuotai and HgS groups. However, all mercury compounds were able to increase the Nrf2 pathway genes NAD(P)H: quinone oxidoreductase 1 (Nqo1) and Glutamate-cysteine ligase, catalytic subunit (Gclc). In conclusion, the Tibetan medicine Zuotai and HgS are less hepatotoxic than HgCl2 and MeHg, and differ from HgCl2 and MeHg in hepatic Hg accumulation and toxicological responses.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/etiologia , Hepatócitos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Medicina Tradicional Tibetana , Cloreto de Mercúrio/toxicidade , Compostos de Mercúrio/toxicidade , Compostos de Metilmercúrio/toxicidade , Animais , Biomarcadores/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/genética , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Regulação da Expressão Gênica/efeitos dos fármacos , Hepatócitos/metabolismo , Hepatócitos/ultraestrutura , Mediadores da Inflamação/metabolismo , Fígado/metabolismo , Fígado/ultraestrutura , Masculino , Cloreto de Mercúrio/metabolismo , Compostos de Mercúrio/metabolismo , Compostos de Metilmercúrio/metabolismo , Camundongos , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fatores de Tempo , Redução de Peso/efeitos dos fármacos
12.
Artigo em Chinês | MEDLINE | ID: mdl-26767252

RESUMO

OBJECTIVE: To evaluate the effects of a novel molluscicide, the salt quinoid-2', 5-dichloro-4'-nitrosalicylanilide from niclosamide (LDS), with 10% wettable powder, in main schistosomiasis epidemic areas of China, including Hunan, Jiangxi, Hubei, Anhui, Jiangsu, Sichuan, Yunnan and Zhejiang Province. METHODS: In the immersion test, 6 effective concentrations of 10% LDS were tested respectively: 0.1, 0.2, 0.4, 0.6, 0.8, 1.0 g/m3 in the field; at the same time, 50% wettable powder of niclosamide ethanolamine salt (WPN) with effective concentrations of 1.0 g/m was used as the molluscicide control, and the fresh water as the blank control, then the mortality rates of 0. hupensis snails were recorded at 24 h, 48 h and 72 h after the immersion. In the spraying test and powder-spraying test, 5 effective dosages of 10% LDS were tested respectively: 0.2, 0.4, 0.6, 0.8, 1.0 g/m2, while 50% WPN 1.0 g/m2 was used as the molluscicide control, and the fresh water as the blank control in the field for 1 d, 3 d and 7 d, then the mortality rates of O. hupensis snails were recorded at 1 d, 3 d and 7 d after the spraying and powder-spraying. RESULTS: The snail mortality rates of LDS using the immersion test for 72 h were more than 95% in the field of eight provinces (0.1 g/m in Sichuan, Jiangxi, Jiangsu and Zhejiang provinces, 0.2 g/m3 in Yunnan, Hunan and Hubei provinces, and 0.4 g/min Anhui Province); the snail mortality rates of LDS using the spraying test for 7 d were more than 85% (0.2 g/m2 in Hunan, Hubei, Jiangxi and Zhejiang provinces, 0.4 g/m2 in Sichuan and Anhui provinces, 0.6 g/m2 in Yunnan and Jiangsu provinces). The snail mortality rates of LDS the powder-spraying test for 7 d were more than 85% (0.6 g/m2 in Yunnan, Sichuan, Hubei, Jiangxi, Anhui, Jiangsu and Zhejiang provinces). According to the standards of "Efficacy test methods and evaluation of molluscicide for pesticide registration (NY/T 1617-2008)", LDS is a qualified molluscicide. CONCLUSIONS: LDS has good molluscicidal effects through the immersion, spraying and powder-spraying test in the fields. It is suitable for a variety of environments to control O. hupensis snails of schistosomiasis endemic areas in China. The recommended dosages of LDS are 0.1-0.2 g/m3 by the immersion method, 0.2-0.4 g/m2 by the spraying method, and 0.4-0.6 g/m2 by the powder-spraying method in the fields.


Assuntos
Moluscocidas/farmacologia , Esquistossomose/prevenção & controle , Caramujos , Animais , China/epidemiologia , Esquistossomose/epidemiologia , Esquistossomose/transmissão
13.
Int J Environ Res Public Health ; 11(10): 10406-18, 2014 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-25310539

RESUMO

Oncomelania hupensis is the sole intermediate host snail of Schistosoma japonicum in China. Snail control by molluscicide remains one of the most effective measures of schistosomiasis japonica control. A 50% wettable powder of niclosamide ethanolamine salt (WPN) is widely used for snail control in China. However, WPN is costly and toxic to fish. A novel molluscicide named LDS, the salt of quinoid-2', 5-dichloro-4'-nitrosalicylanilide from niclosamide, has been developed. To evaluate the effects of large-scale field application of LDS on field snail control, tests were conducted in 15 counties of Hubei Province, China. Active adult snails, were immersed in 0.2, 0.4, and 0.6 g/m3 of 10% LDS, 1.0 g/m3 of 50% WPN was used as the molluscicide control, and then the mortality rates of snails were investigated after 1, 2, and 3 days. In addition, four active concentrations of 10% LDS (0.4, 0.6, 0.8 and 1.0 g/m2) were applied by spraying and powdering in the field. 1.0 g/m2 of 50% WPN was used as the molluscicide control, and then the mortality rates of snails were observed after 1, 3, and 7 days. The results indicated that 0.4 g/m3 LDS applied by the immersion or 0.6 g/m2 LDS applied by spraying and powdering achieved the same molluscicidal effect as that of WPN, regardless of exposure time. By using different methods, the snail mortality rates in the molluscicide groups were related to exposure time and concentration, respectively. LDS costs less than WPN; thus, LDS is suitable and applicable for use as a molluscicide in schistosomiasis japonica epidemic areas.


Assuntos
Moluscocidas/farmacologia , Niclosamida/farmacologia , Controle de Pragas , Caramujos/efeitos dos fármacos , Animais , China , Relação Dose-Resposta a Droga , Esquistossomose Japônica/prevenção & controle
14.
Nanoscale ; 4(18): 5659-64, 2012 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-22868278

RESUMO

A nickel incorporated carbon nanotube/nanofiber composite (Ni-CNT-CNF) was used as a low cost alternative to Pt as counter electrode (CE) for dye-sensitized solar cells (DSCs). Measurements based on energy dispersive X-rays spectroscopy (EDX) showed that the majority of the composite CE was carbon at 88.49 wt%, while the amount of Ni nanoparticles was about 11.51 wt%. Measurements based on electrochemical impedance spectroscopy (EIS) showed that the charge transfer resistance (R(ct)) of the Ni-CNT-CNF composite electrode was 0.71 Ω cm(2), much lower than that of the Pt electrode (1.81 Ω cm(2)). Such a low value of R(ct) indicated that the Ni-CNT-CNF composite carried a higher catalytic activity than the traditional Pt CE. By mixing with CNTs and Ni nanoparticles, series resistance (R(s)) of the Ni-CNT-CNF electrode was measured as 5.96 Ω cm(2), which was close to the R(s) of 5.77 Ω cm(2) of the Pt electrode, despite the significant difference in their thicknesses: ∼22 µm for Ni-CNT-CNF composite, while ∼40 nm for Pt film. This indicated that use of a thick layer (tens of microns) of Ni-CNT-CNF counter electrode does not add a significant amount of resistance to the total series resistance (R(s-tot)) in DSCs. The DSCs based on the Ni-CNT-CNF composite CEs yielded an efficiency of 7.96% with a short circuit current density (J(sc)) of 15.83 mA cm(-2), open circuit voltage (V(oc)) of 0.80 V, and fill factor (FF) of 0.63, which was comparable to the device based on Pt, that exhibited an efficiency of 8.32% with J(sc) of 15.01 mA cm(-2), V(oc) of 0.83, and FF of 0.67.


Assuntos
Corantes/química , Nanofibras/química , Nanotubos de Carbono/química , Níquel/química , Energia Solar , Espectroscopia Dielétrica , Eletrodos , Nanofibras/ultraestrutura , Nanotubos de Carbono/ultraestrutura
15.
ACS Appl Mater Interfaces ; 4(8): 4331-7, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22839659

RESUMO

Soy protein isolate (SPI) and polyethylene oxide (PEO) were dissolved in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) and nonwoven nanofiber membranes were prepared from the solution by electrospinning. PEO functioned as a cospinning polymer in the process to improve the spinnability of SPI. The ratio of SPI to PEO was varied and the rest spinning conditions remained unchanged. The morphology of the nanofiber membranes, SPI and PEO distribution and phase structure in the fiber, crystallization and interaction between SPI and PEO, thermal properties and wettability of the membranes were studied. The results showed that the diameter of most of the nanofibers was in the range of 200-300 nm. SPI and PEO showed high compatibility in the fiber and SPI was homogeneously dispersed at nanoscale. Crystallization of SPI and PEO in the fiber was significantly different from that of their pure forms. All the nanofiber membranes showed superhydrophilicity. These nanofiber membranes can find importance in filtration and biomedical applications.


Assuntos
Materiais Biocompatíveis/química , Nanofibras/química , Nanotecnologia/métodos , Polietilenoglicóis/química , Polímeros/química , Proteínas de Soja/química , Varredura Diferencial de Calorimetria/métodos , Cristalização , Fibroblastos/metabolismo , Temperatura Alta , Propanóis/química , Solventes/química , Propriedades de Superfície , Termogravimetria/métodos , Molhabilidade , Difração de Raios X
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