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1.
Comput Math Methods Med ; 2022: 8604322, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35469224

RESUMO

Background: Septic shock (SS) is the most common severe syndrome in the Intensive Care Unit (ICU). Enhancing the monitoring of hemodynamic indexes in SS patients carries huge clinical implications for reducing patient mortality. Recently, pulse indicator continuous cardiac output (PICCO) has been widely used in clinical practice, but its advantages than central venous pressure (CVP) in guiding the treatment of SS patients remains to be refined. Therefore, this study is aimed at assessing the clinical effects of PICCO in the treatment of patients with SS. Methods: The authors systematically searched several databases (PubMed, EMBASE, Cochrane Library, and China National Knowledge) between January 2001 and February 2021. When searching for relevant articles, the authors combined the following phrases describing the monitoring group ("pulse indicator continuous cardiac output," "central venous pressure") with the disease of interest as well as management ("SS," "sepsis"). The outcomes were independently assessed by two reviewers who scored the articles for methodological quality using the Cochrane Collaboration's "risk of bias" tool. Forest plots, as well as sensitivity and bias analyses, were carried out for the included articles. The primary outcome measures were length of ICU stay, duration of mechanical ventilation, 28-day mortality, and fluid resuscitation volume. Results: Ten studies comprising 350 cases monitored with PICCO and 373 cases monitored with traditional CVP were eventually identified. PICCO-monitored patients were observed to be significantly associated with shorter ICU stay than CVP-monitored patients (MD: -3.04, 95% CI: -4.74 to -1.34, P = 0.0005), shorter time of mechanical ventilation (MD: -1.84, 95% CI: -2.80 to -0.87, P = 0.0002), and lower 28-day mortality (RR: 0.67, 95% CI: 0.48 to 0.94, P = 0.02). The two groups showed no significant difference in subgroup analysis for fluid resuscitation volumes (P > 0.05). Conclusion: PICCO monitoring technique can significantly improve the prognosis of SS patients, shorten the time of mechanical ventilation and ICU stay, and reduce the 28-day mortality, which has positive guiding significance for patients with SS. Given the limitations of the quantity and quality of included studies, further research is warranted to verify the conclusions.


Assuntos
Choque Séptico , Débito Cardíaco , Hidratação , Frequência Cardíaca , Humanos , Monitorização Fisiológica/métodos , Choque Séptico/terapia
2.
Biotechnol Adv ; 27(5): 599-605, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19393732

RESUMO

In this study, we simulated the single-step process of dimethyl ether (DME) synthesis via biomass gasification using ASPEN Plus. The whole process comprised four parts: gasification, water gas shift reaction, gas purification, and single-step DME synthesis. We analyzed the influence of the oxygen/biomass and steam/biomass ratios on biomass gasification and synthesis performance. The syngas H(2)/CO ratio after water gas shift process was modulated to 1, and the syngas was then purified to remove H(2)S and CO(2), using the Rectisol process. Syngas still contained trace amounts of H(2)S and about 3% CO(2) after purification, which satisfied the synthesis demands. However, the high level of cold energy consumption was a problem during the purification process. The DME yield in this study was 0.37, assuming that the DME selectivity was 0.91 and that CO was totally converted. We performed environmental and economic analyses, and propose the development of a poly-generation process based on economic considerations.


Assuntos
Biomassa , Biotecnologia/métodos , Fontes Geradoras de Energia , Gases , Éteres Metílicos/síntese química , Biotecnologia/instrumentação , Dióxido de Carbono , Monóxido de Carbono , Fontes Geradoras de Energia/economia , Desenho de Equipamento , Hidrogênio , Modelos Químicos , Vapor , Temperatura
3.
J Colloid Interface Sci ; 320(2): 501-7, 2008 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-18279880

RESUMO

Titanium hydrate sols were prepared using different acid hydrolysis catalysts, i.e., acetic acid and hydrochloric acid. The platinum-doped TiO(2) sol-gels were also synthesized by adding K(2)PtCl(6) into the titanium hydrate sols. The hydrophobic montmorillonite clay, treated with organic cationic surfactant, i.e., hexadecyltrimethylammonium bromide, was used as a template to prepare TiO(2) pillared photocatalyst with the above sols. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDX) were employed to characterize the resulting photocatalysts. The adsorption performance and photoactivity of prepared pillared clays were studied by using methyl orange as a model organic pollutant. The preliminary results indicated that the hydrophobic TiO(2) pillared clay prepared with acetic acid as the acid hydrolysis catalysts possessed higher photocatalytic activity than that with hydrochloric acid. Due to the excellent sedimentation property of the clay, the resulting pillared photocatalyst is easily recovered and reused in the postrun treatment. Also the doping of platinum into the hydrophobic photocatalyst can increase the photocatalytic activity significantly.


Assuntos
Ácido Acético/química , Silicatos de Alumínio/síntese química , Compostos Azo/química , Ácido Clorídrico/química , Titânio/química , Poluentes Químicos da Água/química , Silicatos de Alumínio/química , Catálise , Cetrimônio , Compostos de Cetrimônio/química , Argila , Microscopia Eletrônica de Varredura , Fotoquímica , Platina/química , Purificação da Água/métodos , Difração de Raios X
4.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 23(3): 660-4, 2006 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-16856411

RESUMO

The latency change detection of EPs is of special interest in many clinical applications such as diagnosis of the injury and pathological changes in the nervous system. This paper reviews the adaptive latency change detection approaches under stable noise conditions, based on the fractional lower order statistics. It also evaluates and compares the performances of the presented algorithms.


Assuntos
Algoritmos , Encéfalo/fisiologia , Potenciais Evocados/fisiologia , Tempo de Reação/fisiologia , Processamento de Sinais Assistido por Computador , Animais , Eletroencefalografia/métodos , Humanos
5.
Chemosphere ; 64(3): 423-31, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16412494

RESUMO

An adsorptive silica-supported titania photocatalyst TiO(2)/SiO(2) was prepared by using nanosized titania (anatase) immobilized on silica gel by the sol-gel technique with the titanium tetra isopropoxide as the main raw material and acetic acid as the acid catalyst. Meanwhile the structure and properties of the TiO(2)/SiO(2) photocatalyst were studied by means of many modern analysis techniques such as TEM, XRD, and BET. Gas-solid heterogeneous photocatalytic decomposition of four carbonyl compounds mixture at low concentration levels over ultraviolet irradiated TiO(2)/SiO(2) photocatalyst were carried out with high degradation efficiencies in a coaxial triple-cylinder-type fluidized bed photocatalytic reactor, which provided efficient continuous contact of ultraviolet photons, silica-supported titania photocatalyst, and gaseous reactants. Experimental results showed that the photocatalyst had a high adsorption performance and a good photocatalytic activity for four carbonyl compounds mixture. Some factors influencing the photocatalytic decomposition of the mixed carbonyl compounds, i.e. the gas flowrate, relative humidity, concentration of oxygen, and illumination time, were discussed in detail. It is found that the photocatalytic reaction rate of four carbonyl compounds decreased in this order: propionaldehyde, acetone, acetaldehyde and formaldehyde.


Assuntos
Poluentes Atmosféricos/análise , Aldeídos/análise , Dióxido de Silício/química , Titânio/química , Gerenciamento de Resíduos , Adsorção , Catálise , Gases/análise , Nanoestruturas/química , Fotoquímica , Sílica Gel , Gerenciamento de Resíduos/instrumentação , Gerenciamento de Resíduos/métodos
6.
Chemosphere ; 59(9): 1367-71, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15857649

RESUMO

The photocatalytic oxidation of the organic pollutants with TiO(2) as photocatalyst has been widely studied in the world, and many achievements have been made. The degradation of pollutants is highly related to the photocatalytic activity of TiO(2). It is demonstrated that doping ions to TiO(2) is one way to enhance the photocatalytic activity of TiO(2). In this paper, Zn(2+)-doped TiO(2) nanoparticles were prepared through sol-gel and solid phase reaction methods, characterized by means of X-ray diffraction (XRD) and transmission electron microscopy (TEM). The photocatalytic activity of the elaborated powders was studied following the degradation of Rhodamine B. The results showed that the photocatalytic activity of Zn(2+)-doped TiO(2) prepared by sol-gel method is close to that of pure TiO(2) particles, however, the photocatalytic activity of Zn(2+)-doped TiO(2) prepared by solid phase reaction method is much higher than that of pure TiO(2) particles. The most efficient degradation of Rhodamine B was found with TiO(2) particles doped with 0.5% Zn(2+) in mole and calcined at 500 degrees C. Also the reason for the enhancement of the photocatalytic activity of TiO(2) by Zn(2+) doping through solid phase reaction method was discussed.


Assuntos
Géis/química , Nanoestruturas/química , Titânio/química , Zinco/química , Catálise , Temperatura Alta , Microscopia Eletrônica de Transmissão , Tamanho da Partícula , Fotoquímica , Rodaminas/química , Rodaminas/efeitos da radiação , Purificação da Água/métodos , Difração de Raios X
7.
Chemosphere ; 55(9): 1287-91, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15081770

RESUMO

The photocatalytic oxidation of the organic pollutants with the TiO2 as photocatalyst has been widely studied in the world, and many achievements have been got. The degradation of pollutants is highly related with the photocatalytic activity of TiO2. It is demonstrated that doping ions or oxides to TiO2 is one way to enhance the photocatalytic activity of TiO2. In this paper, the ZnFe2O4-doped TiO2 nanoparticles were prepared from butyl titanate by a sol-gel method and characterized by means of X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results showed that when TiO2 was doped with ZnFe2O4, its particle size will decrease and its crystal structure will partly transform from anatase to rutile. The photocatalytic activity of the elaborated powders was studied following the degradation of Rhodamine B. The results showed that doping ZnFe2O4 to TiO2 will enhance the photocatalytic activity of TiO2 and that ZnFe2O4-doped TiO2 in the coexistence of anatase and rutile has higher efficiency for the degradation of Rhodamine B than that in the anatase phase alone. Also the different role of O2 in the direct photolysis and photocatalysis of Rhodamine B was discussed.


Assuntos
Compostos Ferrosos/química , Rodaminas/química , Titânio/química , Eliminação de Resíduos Líquidos/métodos , Compostos de Zinco/química , Catálise , Microscopia Eletrônica , Fotoquímica , Temperatura , Difração de Raios X
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