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1.
Phys Chem Chem Phys ; 26(15): 11570-11581, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38533820

RESUMO

The capture and separation of CF4 from CF4/N2 mixture gas is a crucial issue in the electronics industry, as CF4 is a commonly used etching gas and the ratio of CF4 to N2 directly affects process efficiency. Utilizing high-throughput computational screening techniques and grand canonical Monte Carlo (GCMC) simulations, we comprehensively screened and assessed 247 types of pure silicon zeolite materials to determine their adsorption and separation performance for CF4/N2 mixtures. Based on screening, the relationships between the structural parameters and adsorption and separation properties were meticulously investigated. Four indicators including adsorption selectivity, working capacity, adsorbent performance score (APS), and regenerability (R%) were used to evaluate the performance of adsorbents. Based on the evaluation, we selected the top three best-performing zeolite structures for vacuum swing adsorption (LEV, AWW and ESV) and pressure swing adsorption (AVL, ZON, and ERI) processes respectively. Also, we studied the preferable adsorption sites of CF4 and N2 in the selected zeolite structures through centroid density distributions at the molecule level. We expect the study may provide some valuable guidance for subsequent experimental investigations on adsorption and separation of CF4/N2.

2.
J Exp Biol ; 223(Pt 17)2020 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-32665446

RESUMO

High temperatures and heatwaves are rapidly emerging as an important threat to many aspects of physiology and behavior in females during lactation. The body's capacity to dissipate heat is reduced by high ambient temperatures, increasing the risk of hyperthermia. Exposure to wind, a pervasive environmental factor for most terrestrial animals, is known to increase heat loss, but its effects on the reproductive performance of small mammals remains unclear. In the present study, the effects of wind on the energy budgets, resting metabolic rate and milk energy output (MEO) were measured in lactating Swiss mice at 21 and 32.5°C. Females kept at 32.5°C had a significantly lower resting metabolic rate, food intake and MEO, and lighter offspring, than those kept at 21°C. However, exposure to wind increased the asymptotic food intake of females kept at 32.5°C by 22.5% (P<0.01), their MEO by 20.7% (P<0.05) and their litter mass by 17.6% (P<0.05). The body temperature of females kept at 32.5°C was significantly higher during lactation than that of females kept at 21°C, but this difference was reduced by exposure to wind. These findings suggest that exposure to wind considerably improves reproductive performance, increasing the fitness of small mammals while undergoing hot temperatures during heatwaves.


Assuntos
Temperatura Alta , Lactação , Animais , Ingestão de Energia , Metabolismo Energético , Feminino , Tamanho da Ninhada de Vivíparos , Camundongos , Gravidez , Vento
3.
Artigo em Inglês | MEDLINE | ID: mdl-32673739

RESUMO

Adaptive adjustments of energy intake and body fat play an important role in allowing animals' to meet the energy demands of thermoregulation during cold conditions and reproduction. Body fat is usually metabolized during lactation, which is one of the most energetically demanding activities of female mammals, however the effect of this on the energy budget and body fat regulation after lactation remains unclear. We compared the energy intake and body fat of female striped hamsters (Cricetulus barabensis) fed either a high-fat or low-fat diet for 21 days after the end of lactation (post-lactation, PL) to those of virgin controls. Serum leptin levels and the expression of hypothalamic orexigenic and anorexigenic neuropeptide genes were also measured and compared. Although lactating females consumed significantly more food, they had significantly lower body fat than virgin controls. The energy intake and body fat levels of the PL females were, however, significantly higher than those of virgin females. This was particularly true for the PL females that were fed high-fat diet. These females had significantly higher serum leptin concentrations, but lower hypothalamic leptin receptor gene expression, than virgin females. Neither orexigenic nor anorexigenic neuropeptide levels in the hypothalamus differed significantly between the PL and virgin females. This suggests that a negative energy balance during lactation drives fat accumulation after lactation. Furthermore, leptin resistance may occur after the end of lactation, causing females to consume more food, and accumulate more fat, than virgin females.


Assuntos
Cricetulus/fisiologia , Ingestão de Energia/fisiologia , Metabolismo Energético/fisiologia , Lactação , Leptina/biossíntese , Receptores para Leptina/biossíntese , Tecido Adiposo/metabolismo , Ração Animal , Animais , Sangue , Composição Corporal , Peso Corporal/fisiologia , Cricetinae , Ingestão de Alimentos/fisiologia , Feminino , Hipotálamo/metabolismo , Neuropeptídeos/metabolismo
4.
Interdiscip Sci ; 10(2): 311-319, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29282626

RESUMO

Aflatoxins are sequential of derivatives of coumarin and dihydrofuran with similar chemical structures and well-known carcinogenic agent. Many studies performed to detoxify aflatoxins, but the result is not ideal. Therefore, we studied structural, infrared spectrum, mechanical, and optical properties of these compounds in the aim of perspective physics. Mulliken charge distributions and infrared spectral analysis performed to understand the structural difference between the basic types of aflatoxins. In addition, the effect of pressure, different polarized, and incident directions on their structural changes was determined. It is found that AFB1 is most stable structure among four basic types aflatoxins (AFB1, AFB2, AFG1, and AFG2), and IR spectra are analyzed to exhibit the difference on structures of them. The mechanical properties of AFB1 indicate that the structure of this toxin can be easily changed by pressure. The real [Formula: see text] and imaginary [Formula: see text] parts of the dielectric function, and the absorption coefficient [Formula: see text] and energy loss spectrum [Formula: see text] were also obtained under different polarized and incident directions. Furthermore, biological experiments needed to support the toxic level of AFB1 using optical technologies.


Assuntos
Aflatoxinas/química , Aflatoxinas/metabolismo , Fenômenos Mecânicos , Fenômenos Ópticos , Pressão , Elasticidade , Inativação Metabólica , Modelos Moleculares , Espectrofotometria Infravermelho , Temperatura
5.
Zhongguo Zhong Yao Za Zhi ; 41(8): 1516-1522, 2016 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-28884549

RESUMO

The aim of this paper was to investigate and compare the penetration-enhancing characteristics of menthol and essential oil from Mentha haplocalyx(M.haplocalyx oil) on the transdermal absorption of the complex traditional Chinese medicine(TCM) components. A series of TCM components were selected as model drugs based on their lipophilicity (logP value), namely osthole(OT, logP=3.85), tetramethylpyrazine(TMP, logP=2.34), ferulic acid(FA, logP=1.26), puerarin(PR, logP=-0.35) and geniposide(GP, logP=-1.01), in order to simply and characterize the TCM complex components system. Transdermal experiment in vitro was employed to investigate and compare the penetration-enhancing characteristics of menthol and M.haplocalyx oil on the transdermal absorption of these model drugs. Meanwhile, Fourier transform infrared spectroscopy(FTIR) was used to further compare the effect of menthol and M. haplocalyx oil on the molecular structure of stratum corneum(SC). The results showed that both of menthol and M.haplocalyx oil at proper concentration could promote the transdermal absorption of the selected model drugs. After application of menthol, the drug logP values gradually tended to have negative linear relationship with the logarithm of penetration enhancement ratio(ER); while after application of M.haplocalyx oil, the logP values tended to have parabolic relationship with the logarithm of ER. However, both menthol and M.haplocalyx oil exhibited higher efficiency for the drugs with relative low lgP value(ie hydrophilic drugs), with similar penetration-enhancing characteristics between these two. Infrared spectroscopy results showed that menthol and M.haplocalyx oil could affect the skin barrier functions mainly via stratum corneum lipids, with similar effect intensity, and this was consistent with the results of transdermal experiment in vitro. Thus, Menthol had similar penetration-enhancing characteristics with M.haplocalyx oil, and had same effect on the SC molecular structure. Therefore, as transdermal penetration enhancer, the menthol with single composition could be considered to replace M.haplocalyx oil with complex compositions.


Assuntos
Mentha/química , Mentol/farmacologia , Óleos Voláteis/farmacologia , Absorção Cutânea , Administração Cutânea , Pele
6.
Zhongguo Zhong Yao Za Zhi ; 41(6): 1046-1053, 2016 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-28875668

RESUMO

To optimize the matrix formulation of Chaizhi cataplasma (CC) and investigate its release and transdermal absorption properties in vitro. The optimized matrix formulation of cataplasma containing liquid herbal extract is determined by using D-optimal mixture design, with initial bonding strength, endurance bonding strength and gel strength as the evaluating indicators. Modified Franz diffusion cells were used to study the in vitro release and transdermal absorption of geniposide in CC. The optimized matrix formulation of CC contained NP700, aluminum glycinate, tartaric acid, glycerin, PVPK90 and water (9∶0.7∶0.8∶30∶5∶30.5). Cumulative release rate of geniposide in CC was (77.02±3.73)% in 24 h. The percutaneous penetration rate of geniposide was 7.25 µg•cm⁻²â€¢h⁻¹ and the 24 h permeated amount was (156.22±4.90) µg•cm⁻². The optimized CC prepared by the D-optimal mixture design showed a good adhesion and formability. The in vitro release of the geniposide in CC was in accordance with the first order equation, while its in vitro transdermal absorption was close to the zero order equation.


Assuntos
Química Farmacêutica/métodos , Medicamentos de Ervas Chinesas/química , Administração Cutânea , Animais , Medicamentos de Ervas Chinesas/administração & dosagem , Medicamentos de Ervas Chinesas/farmacocinética , Iridoides/administração & dosagem , Iridoides/química , Iridoides/farmacocinética , Camundongos , Camundongos Endogâmicos ICR , Pele/efeitos dos fármacos , Pele/metabolismo , Absorção Cutânea
7.
Zhongguo Zhong Yao Za Zhi ; 40(4): 643-8, 2015 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-26137684

RESUMO

The aim of this paper was to investigate the effect of terpene penetration enhancers on membrane fluidity and membrane potential using HaCaT keratinocytes, and study the potential mechanisms of these terpene compounds using as natural transdermal penetration enhancer. Six terpene compounds, namely menthol, limonene, 1,8-cineole, menthone, terpinen-4-ol and pulegone, were chosen in this study on account of their good penetration-enhancement activities. The cytotoxicity of these terpene compounds was measured using an MTT assay. The fluorescence recovery after photobleaching (FRAP) technique was employed to measure the change of membrane fluidity of HaCaT cells. The flow cytometer was used to study the alteration of membrane fluidity of HaCaT cells, and investigate the effect of terpene compounds on intracellular Ca2+. It was found that 6 terpene compounds possessed low cytotoxicity in comparison to the well-established and standard penetration enhancer azone. Those terpene compounds could significantly enhance HaCaT cells membrane fluidity and decrease HaCaT cells membrane potentials. Meanwhile, after treated with various terpene compounds, the Ca2(+)-ATPase activity and intracellular Ca2+ of HaCaT cells was decreased significantly. Terpene penetration enhancers perhaps changed the membrane fluidity and potentials of HaCaT cells by altering the Ca2+ balance of the cell inside and outside, resulting in the low skin permeability to increase the drug transdermal absorption.


Assuntos
Medicamentos de Ervas Chinesas/farmacocinética , Queratinócitos/metabolismo , Terpenos/farmacocinética , Linhagem Celular , Humanos , Queratinócitos/efeitos dos fármacos , Fluidez de Membrana/efeitos dos fármacos , Absorção Cutânea/efeitos dos fármacos
8.
Guang Pu Xue Yu Guang Pu Fen Xi ; 34(6): 1649-55, 2014 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-25358181

RESUMO

Basin soil type, moisture content and vegetation cover index are important factors affecting the basin water of Yongding River, using traditional sampling method to investigate soil moisture and the watershed soil type not only consuming a lot of manpower and material resources but also causing experimental error because of the instrument and other objective factors. This article selecting the Yongding River Basin-Beijing section as the study area, using total station instruments to survey field sampling and determination 34 plots, combined with 6 TM image data from 1978 to 2009 to extract soil information and the relationship between region's soil type, soil moisture and remote sensing factors. Using genetic algorithms normalization to select key factors which influenced NDWI, which is based on the green band and near-infrared bands normalized ratio index, usually used to extract water information in the image. In order to accurate screening and factors related to soil moisture, using genetic algorithms preferred characteristics, accelerate the convergence by controlling the number of iterations to filter key factor. Using multiple regression method to establish NDWI inversion model, which analysis the accuracy of model is 0.987, also use the species outside edges tree to meet accuracy test, which arrived that soil available nitrogen, phosphorus and potassium content and longitude correlation is not obvious, but a positive correlation with latitude and soil, inner precision researched 87.6% when the number of iterations to achieve optimal model calculation Maxgen. Models between NDWI and vegetation cover, topography, climate ect, through remote sensing and field survey methods could calculate the NDWI values compared with the traditional values, arrived the average relative error E is -0.021%, suits accord P reached 87.54%. The establishment of this model will be provide better practical and theoretical basis to the research and analysis of the watershed soil moisture and organic of Yongding River.


Assuntos
Tecnologia de Sensoriamento Remoto , Solo , Água , Algoritmos , Clima , Modelos Teóricos , Nitrogênio , Fósforo , Potássio , Rios
9.
Zhonghua Zhong Liu Za Zhi ; 26(7): 430-2, 2004 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-15355650

RESUMO

OBJECTIVE: To evaluate the efficacy and adverse reactions of Herceptin as a single agent in patients with HER2 overexpressing metastatic breast cancer. METHODS: There were two kinds of therapy protocol. One was loading-dose of 4 mg/kg intravenously, followed by a 2 mg/kg maintenance dose of weekly intervals. The other was loading-dose of 8 mg/kg, followed by 6 mg/kg of every three weeks intervals. RESULTS: Among 20 patients with evaluated efficacy, there was no complete response, 5 patients (25.0%) showed partial response (PR), 5 (25.0%) stable disease (SD) and 10 (50.0%) progressive disease (PD). Of 22 patients, the overall response rate was 22.7%. The median time of disease progression and treatment failure was 6 weeks and 6.5 weeks, respectively. The most common adverse reactions were fever and chill. Cardiac symptoms could be seen in some patients. CONCLUSION: Herceptin is an active agent for the patients with HER2 overexpressing metastatic breast cancer and the adverse events are well tolerated.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Antineoplásicos/administração & dosagem , Neoplasias da Mama/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Receptor ErbB-2/metabolismo , Adulto , Idoso , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais Humanizados , Antineoplásicos/efeitos adversos , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/secundário , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Progressão da Doença , Intervalo Livre de Doença , Esquema de Medicação , Feminino , Febre/induzido quimicamente , Cardiopatias/induzido quimicamente , Humanos , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/metabolismo , Neoplasias de Tecidos Moles/tratamento farmacológico , Neoplasias de Tecidos Moles/secundário , Trastuzumab
10.
Zhonghua Zhong Liu Za Zhi ; 26(6): 379-81, 2004 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-15312353

RESUMO

OBJECTIVE: To evaluate the efficacy and adverse reactions of Xeloda in the treatment of recurrent and metastatic breast cancer. METHODS: This clinical study was designed to treat 69 patients with recurrent and metastatic breast cancer with Xeloda, 2500 mg/m(2)/d, twice daily for 2 weeks followed by a 1-week rest period, repeated every 3 weeks. RESULTS: Sixty-nine patients received Xeloda for more than 1 cycle. The overall response rate (CR + PR) was 16.0%, clinical benefit rate (CR + PR + SD > or = 24 months) was 27.5%, disease control rate (CR + PR + SD) was 75.4%. The median time to failure (TTF) was 3 months (range: 0.7 - 11 months). The median time to progression (TTP) was 2 months (range: 0.7 - 11 months). The median duration of response (CR + PR) was 6 months (range: 4 - 11 months). The most common treatment-related adverse events were hand-foot syndrome (HFS) that occurred in 60.8% (42/69) patients mostly as grade I-II. Fifty-five percent (22/40) of patients who had received high dose preventive Vit B6 developed HFS without grade III; while 69% (20/29) of patients who had not received such treatment did develop HFS including 2 patients with grade III. However, there was not significant difference between the two groups. CONCLUSION: Xeloda is an effective and well tolerated treatment in patients with recurrent and metastatic breast cancer. The symptoms of HFS may be relieved by high dose Vit B6 as prevention.


Assuntos
Antimetabólitos Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Desoxicitidina/análogos & derivados , Desoxicitidina/uso terapêutico , Recidiva Local de Neoplasia/tratamento farmacológico , Adulto , Idoso , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/secundário , Neoplasias da Mama/patologia , Capecitabina , Esquema de Medicação , Feminino , Fluoruracila/análogos & derivados , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/secundário , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/secundário , Metástase Linfática , Pessoa de Meia-Idade
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