Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
1.
J Colloid Interface Sci ; 673: 275-283, 2024 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-38875793

RESUMO

It has been widely accepted that the generation of reactive oxygen species such as superoxide radical, hydroxyl radical, and hydrogen peroxide during photocatalysis is responsible for the degradation of azo dyes. However, it is unclear which reactive oxygen species primarily contributes to the degradation efficiency of azo dyes. Here, we demonstrate that the directional regulation of reactive oxygen species in titanium dioxide (TiO2) to form superoxide radicals by ethylenediaminetetraacetic acid disodium salt (EDTA-2Na) can significantly improve the degradation performance of methyl orange. The optimized addition of EDTA-2Na can completely degrade azo dyes such as methyl orange, acid orange and alkaline orange at a concentration of 10 mg/L in about 20 min, which is not only higher than that achieved by pristine TiO2 under Xe lamp light but also far superior to the reported degradation efficiency of modified TiO2. Even under natural sunlight, this strategy can also effectively decompose azo dyes, demonstrating the great potential for practical water treatment using low-cost TiO2 photocatalysts.

2.
J Affect Disord ; 360: 71-78, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38788854

RESUMO

BACKGROUND: Observational studies have shown that neuroticism is associated with frailty, but the causal relationship between them remains unclear. METHODS: A two-sample Mendelian randomization (MR) study was conducted to explore the bidirectional causal relationship between neuroticism (n = 380,506 for the primary analysis, n = 79,004 for the validation) and frailty (n = 175,226) using publicly available genome-wide association study data. The inverse variance weighted (IVW), weighted median, and MR-Egger were used to obtain the causal estimates. Findings were verified through extensive sensitivity analyses and validated using another dataset. Multivariable MR (MVMR) analysis was performed to estimate the direct causal effects with adjustment of potential confounders. Two-step MR technique was then conducted to explore the mediators in the causal effects of neuroticism on frailty. RESULTS: Genetically-predicted higher neuroticism score was significantly correlated with higher frailty index (IVW beta: 0.53, 95%CI: 0.48 to 0.59, P = 9.3E-83), and genetically-determined higher frailty index was significantly associated with higher neuroticism score (IVW beta: 0.28, 95%CI: 0.21 to 0.35, P = 1.3E-16). These results remained robust across sensitivity analyses and were reproducible using another dataset. The MVMR analysis indicated that the causal relationships remained significant after adjusting for the potential confounding factors. Mediation analysis revealed that depression, years of schooling, and smoking were significantly mediated the causal effects of neuroticism on frailty. CONCLUSIONS: A bidirectional causal relationship existed between neuroticism and frailty. Our findings suggested that early intervention and behavioral changes might be helpful to reduce the neuroticism levels and prevent the development of frailty.


Assuntos
Fragilidade , Estudo de Associação Genômica Ampla , Análise da Randomização Mendeliana , Neuroticismo , Humanos , Fragilidade/genética , Causalidade , Masculino , Feminino , Idoso , Polimorfismo de Nucleotídeo Único
3.
Nat Commun ; 15(1): 2600, 2024 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-38521830

RESUMO

Amorphous semiconductors without perfect crystalline lattice structures are usually considered to be unfavorable for photocatalysis due to the presence of enriched trap states and defects. Here we demonstrate that breaking long-range atomic order in an amorphous ZnCdS photocatalyst can induce dipole moments and generate strong electric fields within the particles which facilitates charge separation and transfer. Loading 1 wt.% of low-cost Co-MoSx cocatalysts to the ZnCdS material increases the H2 evolution rate to 70.13 mmol g-1 h-1, which is over 5 times higher than its crystalline counterpart and is stable over the long-term up to 160 h. A flexible 20 cm × 20 cm Co-MoSx/ZnCdS film is prepared by a facile blade-coating technique and can generate numerous observable H2 bubbles under natural sunlight, exhibiting potential for scale-up solar H2 production.

4.
Angew Chem Int Ed Engl ; 62(10): e202217346, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36642699

RESUMO

Sluggish oxygen evolution kinetics are one of the key limitations of bismuth vanadate (BiVO4 ) photoanodes for efficient photoelectrochemical (PEC) water splitting. To address this issue, we report a vanadium oxide (VOx ) with enriched oxygen vacancies conformally grown on BiVO4 photoanodes by a simple photo-assisted electrodeposition process. The optimized BiVO4 /VOx photoanode exhibits a photocurrent density of 6.29 mA cm-2 at 1.23 V versus the reversible hydrogen electrode under AM 1.5 G illumination, which is ca. 385 % as high as that of its pristine counterpart. A high charge-transfer efficiency of 96 % is achieved and stable PEC water splitting is realized, with a photocurrent retention rate of 88.3 % upon 40 h of testing. The excellent PEC performance is attributed to the presence of oxygen vacancies in VOx that forms undercoordinated sites, which strengthen the adsorption of water molecules onto the active sites and promote charge transfer during the oxygen evolution reaction. This work demonstrates the potential of vanadium-based catalysts for PEC water oxidation.

5.
Front Oncol ; 12: 1070001, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36605440

RESUMO

Purpose: To compare the pharmacokinetic (PK) bioequivalence (BE) and safety of a generic pegylated liposomal doxorubicin (PLD) formulation with the reference product Caelyx®. Methods: A multicenter, single-dose, open-label, randomized, two-way crossover study was conducted in patients with breast cancer. For each period, the patients were administered with the test or the reference PLD intravenously at a dose of 50 mg/m2. Cmax, AUC0-t and AUC0-∞ for free, and encapsulated doxorubicin (doxorubicin) and partial AUC (AUC0-48h, AUC48h-t) for encapsulated doxorubicin were evaluated in 17 blood samples taken predose, and increasing time intervals over the following 14 days in each period. A washout period of 28-35 days was observed before crossing over. Results: 48 patients were enrolled and randomised, of which 44 were included and analysed in bioequivalence set (BES). The 90% confidence intervals (CIs) of the geometric mean ratio (GMR) of Cmax, AUC0-t and AUC0-∞ for free doxorubicin and encapsulated doxorubicin all fall within the bioequivalent range of 80% to 125%. The 90% CIs of GMR of partial AUC (AUC0-48h, AUC48h-t) for encapsulated doxorubicin also fall within the bioequivalent range. 48 patients were all included in the safety set (SS). The incidence of treatment-emergent adverse events (TEAEs) related to T and R was 95.8% (46/48) and 97.8% (45/46) respectively. The highest incidence of TEAEs was various laboratory abnormalities. 2 patients withdrew due to T-drug-related AEs. Only one patient experienced serious adverse events and no death occurred in this study. There were no significant differences between the safety profiles of the generic formulation and Caelyx®. Conclusions: Bioequivalence between the test and the reference products was established for free and encapsulated doxorubicin. Clinical trial registration: http://www.chinadrugtrials.org.cn, identifier [CTR20210375].

6.
Cell Signal ; 73: 109674, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32446903

RESUMO

Diarrhea-predominant irritable bowel syndrome (IBS-D) is a prevalent gastrointestinal disorder with a high incidence in children. The role of long non-coding RNAs (lncRNAs) in gastrointestinal diseases has been previously highlighted. Nevertheless, the underlying regulatory mechanism of lncRNA X inactivate-specific transcript (XIST) in IBS-D requires further studies. Thus, the present study was conducted with the main objective of elucidating the underlying mechanism of lncRNA XIST in visceral hypersensitivity in IBS-D. An in vivo mouse model of IBS-D was constructed via rectal perfusion of acetic acid. Next, in order to evaluate the effect of lncRNA XIST on the development of visceral hypersensitivity in IBS-D, different vector plasmids were injected into mice along with rectal mucosal epithelial cells, followed by the measurement of abdominal withdrawal reflex (AWR) score, counts of peristaltic wave, abdominal wall contraction and defecation particles. Furthermore, luciferase reporter assay, FISH, RIP and ChIP assays were conducted to determine the interactions between lncRNA XIST and SERT. Subsequently, MS-PCR was adopted to test the methylation level of SERT promoter. 5-hydroxytrytophan (HT) content in rectal tissues was detected using immunohistochemistry. The IBS-D mouse models presented with a high expression of lncRNA XIST along with low expression of SERT. LncRNA XIST was observed to recruit methylase DNMT1, DNMT3A and DNMT3B to promote SERT promoter methylation, reducing its expression. Restoration of lncRNA XIST resulted in increased AWR score, counts of peristaltic wave, abdominal wall contraction and defecation particles along with stimulated 5-HT expression and SERT methylation level, while downregulation of lncRNA XIST reversed these effects. In conclusion, the key findings from our study indicated that lncRNA XIST acts as a regulator in 5-HT-induced visceral hypersensitivity in mice with IBS-D, providing a new insight into the regulatory effect of lncRNA XIST and its epigenetic diagnostic and therapeutic properties in IBS-D.


Assuntos
Mucosa Intestinal/metabolismo , Síndrome do Intestino Irritável/metabolismo , RNA Longo não Codificante/fisiologia , Proteínas da Membrana Plasmática de Transporte de Serotonina/metabolismo , Animais , Células Cultivadas , Epigênese Genética , Feminino , Mucosa Intestinal/patologia , Masculino , Camundongos
7.
ACS Appl Mater Interfaces ; 11(7): 7250-7260, 2019 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-30672688

RESUMO

The exact mechanism responsible for the phenomenon known as photoignition with an enhanced photothermal effect in high-surface-area carbon with the addition of a metal catalyst is an open issue. Here, we report the first successful flash ignition of a pure carbon material in ambient air microporous carbon aerogels (CAs) with ultralow density and high surface area. Under flash exposure, the CAs show a strong local heat confinement effect near microporous structures (0.6-2 nm), and the graphite crystallite structures existing in single carbon nanoparticles (∼15 nm) are damaged. The local heat confinement effects are mainly derived from the low gaseous thermal conductivity in micropores and low solid thermal conductivity in low-density CAs. In addition, the limiting effects of the microporous structure on the vibration amplitude of free-state electrons in low-density CAs result in a dramatic increase in optical absorption. Numerical simulations of unsteady temperature fields of CAs with different densities and thicknesses are also performed, and the calculated maximum temperature of a 17 µm-thick 20 mg/cm3 CA bed is 1782 °C. CAs with higher density can also give rise to enhanced photothermal response and ignition with the addition of metal Fe nanoparticles. The metal catalyst increases both the light absorption capacity in the visible-light range and the heat accumulation capacity. These results are important for understanding the mechanism of flash ignition, especially the local high temperature and effects of metal catalyst in carbon materials during the photothermal process.

8.
J Phys Condens Matter ; 30(9): 095301, 2018 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-29417933

RESUMO

Two-dimensional (2D) materials with strictly planar hyper-coordinated motifs are of great importance in fundamental science and potential applications but extremely rare. Here we theoretically design a novel 2D IIB-VIA inorganic system, namely Zn3O2 monolayer, by comprehensive first-principles computations. This Zn3O2 monolayer is composed from highly symmetrical tri-coordinated oxygen and tetra-coordinated zinc, featuring planar and peculiar triangle and pentangle combined bonded network. The newly predicted Zn3O2 monolayer possesses excellent dynamic and thermal stabilities and is also the lowest-energy structure of its 2D space indicated by particle swarm search, supporting its experimentally synthetic viability. A relatively wide band gap of 4.46 eV means it has potential applications in electronics and optoelectronics. The present findings provide a new field of hyper-coordinated 2D nanomaterials for study.

9.
Inorg Chem ; 57(4): 1958-1963, 2018 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-29419290

RESUMO

Designing new materials with reduced dimensionality and distinguished properties has continuously attracted intense interest for materials innovation. Here we report a novel two-dimensional (2D) Zn2C monolayer nanomaterial with exceptional structure and properties by means of first-principles calculations. This new Zn2C monolayer is composed of quasi-tetrahedral tetracoordinate carbon and quasi-linear bicoordinate zinc, featuring a peculiar zigzag-shaped buckling configuration. The unique coordinate topology endows this natural 2D semiconducting monolayer with strongly strain tunable band gap and unusual negative Poisson ratios. The monolayer has good dynamic and thermal stabilities and is also the lowest-energy structure of 2D space indicated by the particle-swarm optimization (PSO) method, implying its synthetic feasibility. With these intriguing properties the material may find applications in nanoelectronics and micromechanics.

10.
Phys Chem Chem Phys ; 19(47): 32086-32090, 2017 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-29182171

RESUMO

Designing new two-dimensional (2D) materials with novel band topologies has continuously attracted intense interest in fundamental science and potential applications. Here, we report a unique 2D Mg2C monolayer featuring quasi-planar hexa-coordinate magnesium and hexa-coordinate carbon, which can be tuned from a metal to a semiconductor. The system has been studied using density functional theory, including electronic structure calculations and molecular dynamics simulations. In the freestanding state, the Mg2C monolayer behaves as a weak metal; however, by increasing the biaxial tensile strains, it can gradually be modulated to a gapless semimetal and then to a semiconductor. The Mg2C monolayer exhibits excellent dynamic and thermal stabilities and is also the global minimum of the 2D Mg2C system, implying the feasibility of its experimental synthesis. With unique band structures, the material may find applications in optoelectronics and electromechanics.

11.
Nephrology (Carlton) ; 19(2): 94-100, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24171710

RESUMO

AIM: Henoch-Schoenlein nephritis (HSPN) is a severe disease in adults and may cause renal insufficiency in a large portion of patients. But its rarity has led to lack of data. There are few controlled studies on therapy with immunosuppressants in HSPN adults. This study aims to evaluate the effect of leflunomide on HSPN adults with nephrotic proteinuria. METHODS: We retrospectively studied 65 adult patients who had biopsy-proven HSPN with nephrotic proteinuria. Twenty-seven patients (Group P) only received steroids, and 38 (Group P + L) were treated with leflunomide in addition to steroids. The clinical features, laboratory data and pathological findings of both groups were analyzed. RESULTS: The two groups were well-matched at baseline. After 24 months of treatment, urinary protein excretion of both groups decreased significantly from the baseline, and the estimated glomerular filtration rate (eGFR) was higher in Group P + L. Four patients in Group P and three in Group P + L developed to end-stage renal disease at the most recent follow-up. Group P + L showed better renal outcome than Group P. The treatment group and the degree of mesangial hypercellularity were significantly related to renal prognosis. CONCLUSION: Leflunomide combined with steroids is effective for treating adult HSPN with nephrotic proteinuria.


Assuntos
Corticosteroides/administração & dosagem , Vasculite por IgA/tratamento farmacológico , Isoxazóis/administração & dosagem , Rim/fisiopatologia , Nefrose/tratamento farmacológico , Proteinúria/tratamento farmacológico , Adulto , Idoso , Feminino , Humanos , Vasculite por IgA/fisiopatologia , Isoxazóis/efeitos adversos , Leflunomida , Masculino , Pessoa de Meia-Idade , Nefrose/fisiopatologia , Proteinúria/fisiopatologia , Estudos Retrospectivos
12.
Acta Pharmacol Sin ; 32(12): 1513-21, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21986574

RESUMO

AIM: Vascular endothelial growth factor (VEGF) has been shown to be a survival factor for renal tubular epithelial cells. In the present study, we investigated whether administration of VEGF ameliorates tubulointerstitial fibrosis in a mouse model of unilateral ureteral obstruction (UUO). METHODS: Thirty-six male CD-1 mice were randomly divided into three groups: sham-operation, UUO and UUO+VEGF group. VEGF (50 µg/kg) was subcutaneously injected twice daily from d 1 to d 14. Mice in each group were killed at d 3, 7, or 14 after the operation, and the tubulointerstitial fibrosis was histopathologically evaluated. Human proximal tubular epithelial cells (HK-2) were used for in vitro study. The expression levels of α-SMA, E-cadherin, TGF-ß1, CTGF, and BMP-7 in the kidney were determined using Western blot and RT-PCR. RESULTS: In the UUO mice, the degree of interstitial fibrosis was dramatically increased in a time-dependent manner. At d 3, 7, and 14, both the mRNA and protein expression levels for α-SMA, TGF-ß1, and CTGF were significantly upregulated, whereas those for E-cadherin and BMP-7 were significantly downregulated. At d 3 and 7, VEGF treatment significantly reduced interstitial fibrosis and the expression levels for α-SMA, TGF-ß1, and CTGF, while significantly increased the expression of E-cadherin and BMP-7, as compared with the UUO mice. At d 14 after operation, no significant differences were observed in the expression of the examined markers between VEGF-treated mice and UUO mice, with the exception of CTGF. In HK-2 cells, VEGF blocked TGF-ß1-induced α-SMA and vimentin expression and restored E-cadherin expression in a dose-dependent manner. CONCLUSION: VEGF may ameliorate renal tubulointerstitial fibrosis at the early stage in UUO mice. This effect may be related to inhibition of VEGF on renal tubular epithelial-mesenchymal transition (EMT).


Assuntos
Transição Epitelial-Mesenquimal , Fibrose/prevenção & controle , Obstrução Ureteral/patologia , Fator A de Crescimento do Endotélio Vascular/fisiologia , Animais , Humanos , Masculino , Camundongos
13.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 28(6): 672-4, 2010 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-21365851

RESUMO

OBJECTIVE: To compare the therapeutic efficacy both apexification and revascularization in the immature anterior teeth of animal model with apical periodontitis, and observe the histological situation of revascularization in the root canal. METHODS: Six immature anterior teeth of one animal model (dog) aged approximately 4.5 months was selected. Afterwards, periapical periodontitis pattern were established, the samples were randomly divided into the experimental group (revascularization, 3 teeth) and the control group (apexification, 3 teeth). To compare the development of root and the healing of periapical inflammation, the involved teeth were respectively radiographed 1, 4, 8 weeks after surgery. The animals were sacrificed after 8 weeks, and the closure of apical foramen and the content of root canal were observed by hematine-eosine (HE) staining. RESULTS: The postoperative radiography after 1 week and 4 weeks, the apical foramen size and the periapical radiolucency of the samples was shown no perceptual change. After 8 weeks, the experimental group periapical radiolucency area was obviously more narrowing, and had a apical closure tendency whereas the thickness of the root canal walls had imperceptible changed. While the control group periapical radiolucency change varied. The granulation tissue could be seen within the lumen of the experimental group, which contained a large number of irregular calcification, the calcification was obvious in the apical and adjacent the root canal wall. A small quantity of hard tissue was deposited in the apical of the control group. CONCLUSION: Revascularization may increase the recovery of immature anterior teeth with chronic periapical inflammation, the vital regenerative tissue within root canal is the granulation tissue contained calcification.


Assuntos
Periodontite Periapical , Ápice Dentário , Animais , Polpa Dentária , Cães , Humanos , Tratamento do Canal Radicular , Raiz Dentária
14.
Ying Yong Sheng Tai Xue Bao ; 19(12): 2572-6, 2008 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-19288705

RESUMO

Reaumuria trigyna is a relic species in the desert shrubbery vegetation in arid regions of northwestern China, and plays an important role in the maintenance of the stability of desert vegetation. In this paper, the seed traits and germination strategy of R. trigyna under different environmental conditions, e.g., light, temperature, soil moisture, and sand bury, were investigated. The results showed that R. trigyna seed had high vigor and high germination rate, and endured reserve. The seed could germinate either in light or in darkness, and the optimal temperature for germination was 20 degrees C - 25 degrees C or 15 degrees C/25 degrees C, with the germination rate being 93%. The seed could start to germinate when soil moisture content was 2%, and the germination rate was the highest (89%) when the moisture content was 12%. The optimal sand burial depth of R. trigyna seed was 1 cm, and no seed would germinate when the sand burial depth was >5 cm. Sand burial depth had significant effects on the seedling's emergence percentage and growth height, but lesser effects on seedling' s mass. Soil moisture and sand burial depth were the main environmental factors limiting the seed germination and seedling emergence of R. trigyna. The high seed germination rate of R. trigyna enhanced the survival risk of its seedlings, which was unfavorable to its handling with the extreme changes of desert environment. Such a character of R. trigyna seed was one of the factors causing the species endangered.


Assuntos
Germinação/fisiologia , Sementes/fisiologia , Tamaricaceae/crescimento & desenvolvimento , China , Clima Desértico , Especificidade da Espécie , Tamaricaceae/fisiologia
15.
Zhonghua Zhong Liu Za Zhi ; 25(3): 282-4, 2003 May.
Artigo em Chinês | MEDLINE | ID: mdl-12839696

RESUMO

OBJECTIVE: To evaluate the efficacy and safety of the oral combination chemotherapy of furtulon (FTL) and cyclophosphamide (CTX) for advanced breast cancer (ABC). METHODS: From Jun 2000 to Jun 2002, eighty-three patients with ABC were treated with the two oral drugs as combined chemotherapy. The mean number of cycles was 5, median number of cycles was 6 (range 2-6). RESULTS: The overall response rate was 45.8%, The median time to progression was 6 months. The treatment was well tolerated, with related Grade 3 clinical adverse effect being only nausea and vomiting in 2 patients (2.4%) and mild hematologic toxicities. CONCLUSION: Oral combined chemotherapy of FTL and CTX, being convenient and safe, is effective for patients with advanced breast cancer.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Administração Oral , Adulto , Idoso , Ciclofosfamida/administração & dosagem , Ciclofosfamida/efeitos adversos , Feminino , Floxuridina/administração & dosagem , Floxuridina/efeitos adversos , Humanos , Pessoa de Meia-Idade
16.
Huan Jing Ke Xue ; 23(6): 31-5, 2002 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-12619274

RESUMO

By using the observational data obtained over the Bohai sea in Aug.-Sep., 2000, the variation characteristics of NOx, O3, SO2 and CO concentrations were firstly shown. The effects of solar radiation and weather conditions on the trace concentrations were analyzed. SO2 concentration was very stable, its' average value was about 0.006 mg.m-3. O3 concentration was mainly controlled by solar radiation. The concentration of CO and NOx was around 2.5-3.5 mg.m-3 and 0.1 mg.m-3, respectively, in weak weathers. Typhoon weather may made their concentrations increasing abruptly in a short time. The distinct differences of the pollutant concentrations between land and sea were also revealed, and the air quality over the Bohai sea in summer season was assessed based on the measurements.


Assuntos
Monóxido de Carbono/análise , Óxidos de Nitrogênio/análise , Ozônio/análise , Água do Mar/análise , Dióxido de Enxofre/análise , Poluentes Químicos da Água/análise , Tempo (Meteorologia)
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA