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1.
Molecules ; 26(13)2021 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-34206683

RESUMEN

Crystalline materials containing hybrid inorganic-organic metal borates (complexes with oxidoborate ligands) display a variety of novel framework building blocks. The structural aspects of these hybrid metallaoxidoborates containing Cd(II), Co(II), Cu(II), Ga(III), In(III), Mn(II), Ni(II) or Zn(II) metal centers are discussed in this review. The review describes synthetic approaches to these hybrid materials, their physical properties, their spectroscopic properties and their potential applications.

2.
Cytotherapy ; 21(2): 125-147, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30554868

RESUMEN

BACKGROUND AIMS: Cytokine-induced killer (CIK) cells are the most commonly used cellular immunotherapy for multiple tumors. To further confirm whether chemotherapy with CIK cells improves clinical effectiveness and to reveal its optimal use in non-small cell lung cancer (NSCLC), we systematically reevaluated all relevant studies. METHODS: We collected all studies about chemotherapy with CIK cells for NSCLC from the Medline, Embase, Web of Science, China National Knowledge Infrastructure Database (CNKI), Chinese Scientific Journals Full-Text Database (VIP), Wanfang Data, China Biological Medicine Database (CBM), Cochrane Central Register of Controlled Trials (CENTRAL), Chinese clinical trial registry (Chi-CTR), World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) and U.S. clinical trials. We evaluated their quality according to the Cochrane evaluation handbook of randomized controlled trials (RCTs) (version 5.1.0), extracted the data using a standard data extraction form, synthesized the data using meta-analysis and finally rated the evidence quality using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. RESULTS: Thirty-two RCTs with 2250 patients were included, and most trials had unclear risk of bias. The merged risk ratios values and their 95% confidence intervals of meta-analysis for objective response rate, disease control rate, 1- and 2-year overall survival rates, 1- and 2-year progression-free survival rates were as following: 1.45 (1.31-1.61), 1.26 (1.16-.37), 1.42 (1.23-1.63), 2.06 (1.36-3.12), 1.93 (1.38-2.69) and 3.30 (1.13-9.67). Compared with chemotherapy alone, all differences were statistically significant. CIK cells could increase the CD3+ T cells, CD3+ CD4+ T cells, NK cells and the ratio of CD4+/CD8+ T cells. The chemotherapy with CIK cells had a lower risk of hematotoxicity, gastrointestinal toxicity, liver injury and a higher fever than that of chemotherapy alone. The evidence quality was "moderate" to "very low." CONCLUSIONS: The available moderate evidences indicate that chemotherapy with CIK cells, especially autologous CIK cells, can significantly improve the tumor responses, 1- and 2-year overall and progression-free survival rates in patients with advanced NSCLC. This treatment does have a high risk of fever. The optimal use may be treatment with one or two cycles and in combination with vinorelbine and cisplatin, paclitaxel and cisplatin, or docetaxel and cisplatin.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/terapia , Células Asesinas Inducidas por Citocinas/inmunología , Inmunoterapia/efectos adversos , Neoplasias Pulmonares/terapia , Ensayos Clínicos Controlados Aleatorios como Asunto , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma de Pulmón de Células no Pequeñas/inmunología , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , China , Femenino , Estudios de Seguimiento , Humanos , Inmunidad Celular , Neoplasias Pulmonares/inmunología , Neoplasias Pulmonares/mortalidad , Masculino , Persona de Mediana Edad , Supervivencia sin Progresión , Tasa de Supervivencia , Linfocitos T/inmunología , Adulto Joven
3.
Zhongguo Zhong Yao Za Zhi ; 42(1): 146-151, 2017 Jan.
Artículo en Zh | MEDLINE | ID: mdl-28945040

RESUMEN

To study the effect of ginseng saponin Rh2 in inducing apoptosis of human leukemia K562 cells, and explore its mechanism from the aspect of autophagy pathway. CCK-8 assay was used to examine the growth inhibition of human leukemia cell lines K562 treated with ginsenoside Rh2; flow cytometry (FCM) was used to detect cell apoptosis; Hoechst staining was used to observe the changes of cell morphological apoptosis; Acridine and MDC staining were used to detect the effects of the Rh2 on autophagy; Western blot and RT-PCR were used to detect the expression levels of the proteins closely associated with autophagy and apoptosis. In order to study the effect of autophagy in proliferation and apoptosis, we used the autophagy inhibitor (3-MA).CCK-8 indicated that Rh2 at low concentration could effectively inhibit the proliferation of leukemia cellsin dose- and time-dependent manners in K562 cells; FCM indicated that Rh2 induced apoptosis; Hoechest staining showed that K562 cells had typical apoptotic morphological changes by treated Rh2; Acridine and MDC staining showed that Rh2 enhanced the green fluorescence and a large number of acidic autophagy vesicles were present; Western blot and RT-PCR results showed that Rh2 increased the expression levels of Beclin-1, LC3A, LC3B, activated Caspase-3 and p-p38 in K562 cells; application of autophagy inhibitors(3-MA) could weaken the inhibition effect of Rh2 on proliferation and induction effect on apoptosis in K562 cells. Ginsenoside Rh2 inhibited the proliferation and induced apoptosis probably through activating p-p38, and inducing cell autophagy signaling pathway in K562 cells.


Asunto(s)
Apoptosis , Autofagia , Ginsenósidos/farmacología , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Proliferación Celular , Humanos , Células K562
4.
Huan Jing Ke Xue ; 45(7): 4206-4217, 2024 Jul 08.
Artículo en Zh | MEDLINE | ID: mdl-39022967

RESUMEN

In order to remedy the lack of research on the effect of "Grain for Green" on soil carbon (C) and nitrogen (N) distribution on slope soil in purple hilly areas of Sichuan Basin, China, a study was conducted on a long-term observation site established in the Wanan small watershed of Yanting Agro-ecological Experimental Station of Purple Soil, Chinese Academy of Sciences. The morphology, content, and storage of C and N in soil at different slope positions of farmland and the artificial forests in rehabilitated land with a history of approximately 30 years were compared. Our results showed that "Grain for Green" significantly increased soil organic carbon (SOC) content and SOC stock in all soil layers. The SOC stock of the surface layer (0-20 cm) increased by 25.86 t·hm-2, and the annual SOC stocks ratio was 0.89 t·hm-2. Soil total nitrogen (TN) content increased slightly but only in the 0-20 cm soil layer. Compared with those in sloping farmland, the differences in available C and N nutrients such as soil nitrate N (NO3--N), ammonia N (NH4+-N), and dissolved organic C (DOC) in the whole soil profile (0-70 cm) were basically not significant (P > 0.05). In addition, our research also found that slope position had significant effects on the contents of TN, SOC, NO3--N, NH4+-N, and DOC in farmland soil (P< 0.05). The variation trend of soil NO3--N, NH4+-N, and DOC contents along the slope was as follows: upper slope < middle slope < lower slope, whereas the soil TN and SOC contents were highest in the lower slope, followed by the upper slope and middle slope. The position of the slope had a significant impact only on DOC content in forest soil, which increased along the slope. This research indicated that when evaluating the impact of land use changes on soil C and N stocks in the purple soil hilly region, the influence of topographic factors cannot be ignored.

5.
Huan Jing Ke Xue ; 45(1): 343-353, 2024 Jan 08.
Artículo en Zh | MEDLINE | ID: mdl-38216484

RESUMEN

Since the 1990s, a large area of sloping farmland in a purple soil hilly region of southwest China was converted into an orchard to prevent soil erosion, increase soil fertility, and elevate economic benefits for farmers. In order to explore the spatial distribution of soil carbon (C) and nitrogen (N) fractions on the slope of returning arable lands to citrus orchards in purple soil hilly areas, a soil sampling event was carried out in a citrus orchard at the Yanting Agro-ecological Experimental Station of Purple Soil, Chinese Academy of Sciences, to examine the differences in soil C and N fractions and their influencing factors. The results showed that the slope position had significant effects on the contents of soil total nitrogen (TN), nitrate nitrogen (NO3--N), and dissolved organic carbon (DOC) (P < 0.05), but the effects were not obvious regarding the total organic carbon (SOC) and ammonia nitrogen (NH4+-N) of the soil (P > 0.05). For topsoil (0-30 cm), the variation trend of soil NO3--N content along the slope was upper slope < middle slope < lower slope, whereas the TN and DOC contents along the slope exhibited the trend of upper slope > middle slope > lower slope. The contents of soil C and N in each slope position generally showed a downward trend with increasing soil depth (0-30 cm). The contents of soil TN, SOC, NO3--N, and DOC were significantly affected by soil depth (P < 0.05). The TN storage (0-30 cm) significantly decreased from the top to the bottom within the soil slope, with a value of 2.37, 1.89, and 1.62 t·hm-2 (reported as N) for the upper slope, middle slope, and lower slope, respectively. There was no significant difference in SOC reserves along the slope, with a range from 56.12 to 58.48 t·hm-2 (reported as C). Our results provide scientific basis for understanding the spatial distribution of soil nutrients of the restored farmland in purple soil hilly areas. Our research suggests that the spatial distribution of soil carbon and nitrogen storage should not be ignored when predicting the response of soil nutrients to land use change.

6.
Front Med (Lausanne) ; 11: 1301312, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38405190

RESUMEN

Objectives: Coronavirus disease-19 (COVID-19)/influenza poses unprecedented challenges to the global economy and healthcare services. Numerous studies have described alterations in the microbiome of COVID-19/influenza patients, but further investigation is needed to understand the relationship between the microbiome and these diseases. Herein, through systematic comparison between COVID-19 patients, long COVID-19 patients, influenza patients, no COVID-19/influenza controls and no COVID-19/influenza patients, we conducted a comprehensive review to describe the microbial change of respiratory tract/digestive tract in COVID-19/influenza patients. Methods: We systematically reviewed relevant literature by searching the PubMed, Embase, and Cochrane Library databases from inception to August 12, 2023. We conducted a comprehensive review to explore microbial alterations in patients with COVID-19/influenza. In addition, the data on α-diversity were summarized and analyzed by meta-analysis. Results: A total of 134 studies comparing COVID-19 patients with controls and 18 studies comparing influenza patients with controls were included. The Shannon indices of the gut and respiratory tract microbiome were slightly decreased in COVID-19/influenza patients compared to no COVID-19/influenza controls. Meanwhile, COVID-19 patients with more severe symptoms also exhibited a lower Shannon index versus COVID-19 patients with milder symptoms. The intestinal microbiome of COVID-19 patients was characterized by elevated opportunistic pathogens along with reduced short-chain fatty acid (SCFAs)-producing microbiota. Moreover, Enterobacteriaceae (including Escherichia and Enterococcus) and Lactococcus, were enriched in the gut and respiratory tract of COVID-19 patients. Conversely, Haemophilus and Neisseria showed reduced abundance in the respiratory tract of both COVID-19 and influenza patients. Conclusion: In this systematic review, we identified the microbiome in COVID-19/influenza patients in comparison with controls. The microbial changes in influenza and COVID-19 are partly similar.

7.
Huan Jing Ke Xue ; 44(7): 3933-3944, 2023 Jul 08.
Artículo en Zh | MEDLINE | ID: mdl-37438292

RESUMEN

The Tuojiang River and Fujiang River, two important tributaries of the upper reaches of the Yangtze River, have serious water pollution problems, among which nitrogen (N) and phosphorus (P) are the most important pollutants. Therefore, the aim of this study was to identify the influencing factors of water quality in different spaces and provide a scientific basis for the prevention and control of surface water pollution in the upper reaches of the Yangtze River and its tributaries. Water samples of trunk and tributaries in the Tuojiang River and Fujiang River were collected, and the spatial distribution characteristics of water N and P were analyzed. The results showed that the Tuojiang River and Fujiang River showed serious pollution of total nitrogen (TN), with a water quality worse Ⅴ-section proportion as high as 94% and 50%, respectively. Both rivers showed that TN and TP concentrations in the tributaries were higher than those in the main stream. For both rivers, total phosphorus (TP), with moderate pollution, was mainly concentrated in Ⅱ, Ⅲ, and Ⅳ class water quality, whereas the P pollution was more serious for the Fujiang River compared to that of the Fujiang River. For the Tuojiang River, nitrate nitrogen (NN) concentration from upstream to downstream showed a trend of decreasing after the first increase, with the maximum concentration of ammonium nitrogen (AN) exhibiting at the upstream site. In particular, TP concentration increased significantly after rivers flowed through a city. For the Fujiang River trunk stream, TN and NN concentration exhibited a gradually increasing trend from the middle to lower reaches. Generally, our study revealed that TN, TP, and NN in the rivers were affected by water pH and water temperature (T). Therefore, the control of N and P pollution in rivers should pay attention to the influence of water environmental factors.


Asunto(s)
Contaminantes Ambientales , Nitratos , Nitrógeno , Nutrientes , Fósforo , Contaminación del Agua
8.
Huan Jing Ke Xue ; 41(10): 4539-4546, 2020 Oct 08.
Artículo en Zh | MEDLINE | ID: mdl-33124385

RESUMEN

Shallow groundwater is the main drinking water supply for the mountainous area in the upper reaches of the Yangtze River, while its quality is often degraded by nitrate (NO3--N) pollution due to intensive agricultural production activities. In the present study, we selected a mountainous agricultural watershed in the upper reaches of the Yangtze River to investigate the land use, management, and hydrogeological conditions, aiming to clarify the spatial-temporal variations in NO3--N concentration of shallow groundwater, thereby exploring the key regulators. The results showed that the NO3--N concentrations of the groundwater ranged from 0.40 to 12.51 mg ·L-1in the study area, and the exceeding ratio was nearly 30%. On an average, NO3--N concentrations for the wet season were higher than that for the dry season, indicating great variations in NO3--N concentration across different seasons. In addition, the spatial variations of NO3--N concentration in groundwater were also significant among different sub-catchment, which was mainly due to variations in the groundwater table depth and land uses. Furthermore, the significant correlations between the NO3--N concentrations and concentrations of Cl-, NH4+-N, DOC, and SO42- in the shallow groundwater were also explored in this study, suggesting that the NO3--N concentrations were likely to depend on the chemical factors of the shallow groundwater in the study area. Overall, our current study highlights that the characterization of spatial-temporal variations of NO3--N status in shallow groundwater and illustration of key regulators are essential to mitigate NO3--N pollution and prevent quality degradation of shallow groundwater in mountainous rural areas of the upper Yangtze River watershed.


Asunto(s)
Agua Subterránea , Contaminantes Químicos del Agua , Monitoreo del Ambiente , Nitratos/análisis , Ríos , Contaminantes Químicos del Agua/análisis
9.
J Immunol Res ; 2018: 9081938, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30648123

RESUMEN

OBJECTIVE: DC-CIK therapy included DC-CIK cells and Ag-DC-CIK cells. To further confirm whether DC-CIK reconstructs the antitumor immunity and improves the tumor responses and reveals its optimal usage and combination with chemotherapy, we systematically reevaluated all the related studies. MATERIALS AND METHODS: All studies about DC-CIK plus chemotherapy for NSCLC were collected from the published and ongoing database as CBM, CNKI, VIP, Wanfang, ISI, Embase, MEDLINE, CENTRAL, WHO-ICTRP, Chi-CTR, and US clinical trials (established on June 2017). We evaluated their methodological bias risk according to the Cochrane evaluation handbook of RCTs (5.1.0), extracted data following the predesigned data extraction form, and synthesized the data using meta-analysis. RESULTS: We included 28 RCTs (phase IV) with 2242 patients, but most trials had unclear bias risk. The SMD and 95% CI of meta-analysis for CD3+ T cells, CD3+ CD4+ T cells, CD3+ CD8+ T cells, CD4+/CD8+ T cell ratio, CIK cells, NK cells, and Treg cells were as follows: 1.85 (1.39 to 2.31), 0.87 (0.65 to 1.10), 1.04 (0.58 to 1.50), 0.75 (0.27 to 1.22), 3.87 (2.48 to 5.25), 1.51 (0.99 to 2.03), and -2.31(-3.84 to -0.79). The RR and 95% CI of meta-analysis for ORR and DCR were as follows: 1.38 (1.24 to 1.54) and 1.27 (1.20 to 1.34). All differences were statistically significant between DC-CIK plus chemotherapy and chemotherapy alone. Subgroup analysis showed that only DC-CIK cells could increase the CD3+T cells, CD3+ CD4+T cells, CD3+ CD8+T cells, and CD4+/CD8+ T cell ratio. In treatment with one cycle or two cycles and combination with NP or GP, DC-CIK could increase the CD4+/CD8+ T cell ratio. All results had good stability. CONCLUSIONS: DC-CIK therapy can simultaneously improve the antitumor immunity and tumor responses. DC-CIK therapy, especially DC-CIK cells, can improve antitumor immunity through increasing the T lymphocyte subsets, CIK cell, and NK cells in peripheral blood. The one cycle to two cycles may be optimal cycle, and the NP or GP may be optimal combination.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/terapia , Células Asesinas Inducidas por Citocinas/inmunología , Células Dendríticas/inmunología , Neoplasias Pulmonares/terapia , Linfocitos T/inmunología , Antígenos de Neoplasias/inmunología , Carcinoma de Pulmón de Células no Pequeñas/inmunología , China , Terapia Combinada , Células Asesinas Inducidas por Citocinas/trasplante , Células Dendríticas/trasplante , Humanos , Inmunidad , Neoplasias Pulmonares/inmunología , Activación de Linfocitos , Ensayos Clínicos Controlados Aleatorios como Asunto
10.
Int Immunopharmacol ; 61: 363-375, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29945024

RESUMEN

OBJECTIVE: Cytokine-induced killer cells (CIK) therapy is the most commonly used cellular immunotherapy. The CIK plus radiotherapy was clinically used in a wide range of treatment, but the efficacy of their combination against lung cancer is not clear yet. Therefore, we systematically evaluated all the related studies to reveal the combination's clinical efficacy and safety in lung cancer. MATERIALS AND METHODS: We collected all the studies about CIK plus radiotherapy for lung cancer in Medline, Embase, Web of Science (ISI), China National Knowledge Infrastructure Database (CNKI), Chinese Scientific Journals Full-Text Database (VIP), Wanfang Database, China Biological Medicine Database (CBM) and Cochrane Central Register of Controlled Trials (CENTRAL), Chinese clinical trial registry (Chi-CTR), WHO International Clinical Trials Registry Platform (WHO-ICTRP) and US-clinical trials (March 2017). We evaluated their bias risk according to the Cochrane evaluation handbook of randomized controlled trials (RCTs), extracted all the data, and synthesized the data using meta analysis. RESULTS: We included 16 RCTs involving 1197 patients with lung cancer, and most trials had unclear risk of bias. Meta-analysis showed that CIK therapy could increase the objective response rate (ORR) (1.32, 1.21 to 1.44), the disease control rate (DCR) (1.13, 1.04 to 1.23), the 1-year overall survival (OS) rate (1.38, 1.16 to 1.63) and the 2-year OS rate (1.23, 1.11 to 1.35). DCs-CIK cells increased the 3-year OS rate (1.66, 1.20 to 2.29). DCs-CIK therapy could increase the CD3+T cells (2.27, 1.47 to 3.06), CD4+T cells (1.28, 0.74 to 1.81), NK cells (2.04, 0.74 to 3.33) and CD4+/CD8+ T cells ratio (1.20, 0.64 to 1.76) and decrease the CD8+T cells (-0.84, -1.60 to -0.08). CIK plus radiotherapy had lower risk of leukopenia (0.85, 0.76 to 0.95) and higher risk of fever (5.50, 2.71 to 11.17) than that of radiotherapy alone. Subgroup analysis showed that CIK plus radiotherapy, mainly three dimensional conformal radiotherapy (3D-CRT) could increase the ORR, DCR, 1- and 2- year OS rate in non-small cell lung cancer (NSCLC), and only DCR in small cell lung cancer (SCLC). Compared with CIK plus pure radiotherapy, except for the ORR, DCR, 1-year OS rate, CIK plus chemoradiotherapy could still increase the 2-year OS rate. DCs-CIK could increase the ORR, DCR, 1- and 2-year OS rate, CIK cells could only increase the ORR and the 1-year OS rate. CONCLUSIONS: CIK plus radiotherapy can improve the clinical response, OS and PFS in lung cancer. It may have low risk of leukopenia and high risk of fever. CIK plus chemoradiotherapy, mainly 3D-CRT can improve the clinical response, OS and PFS in NSCLC. DCs-CIK cells can improve the 1-, 2- and 3-year OS rate, and the 1- and 2-year PFS rate, and CIK cells only improve the 1-year OS rate. DCs-CIK cells can repair the antitumor immunity.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/terapia , Células Asesinas Inducidas por Citocinas/inmunología , Neoplasias Pulmonares/terapia , Radioinmunoterapia/métodos , Sesgo , Carcinoma de Pulmón de Células no Pequeñas/inmunología , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Terapia Combinada , Células Asesinas Inducidas por Citocinas/trasplante , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Fiebre/etiología , Humanos , Leucopenia/etiología , Neoplasias Pulmonares/inmunología , Neoplasias Pulmonares/mortalidad , Ensayos Clínicos Controlados Aleatorios como Asunto , Riesgo , Análisis de Supervivencia , Resultado del Tratamiento
11.
J Hazard Mater ; 141(3): 475-82, 2007 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-16987594

RESUMEN

TiO(2) photocatalyst (P-25) (50mgL(-1)) was tentatively introduced into pulsed high-voltage discharge process for non-thermal plasma-induced photocatalytic degradation of the representative mode organic pollutant parachlorophenol (4-CP), including other compounds phenol and methyl red in water. The experimental results showed that rate constant of 4-CP degradation, energy efficiency for 4-CP removal and TOC removal with TiO(2) were obviously increased. Pulsed high-voltage discharge process with TiO(2) had a promoted effect for the degradation of these pollutants under a broad range of liquid conductivity. Furthermore, the apparent formation rates of chemically active species (e.g., ozone and hydrogen peroxide) were increased, the hydrogen peroxide formation rate from 1.10x10(-6) to 1.50x10(-6)Ms(-1), the ozone formation rate from 1.99x10(-8) to 2.35x10(-8)Ms(-1), respectively. In addition, this process had no influence on the photocatalytic properties of TiO(2). The introduction of TiO(2) photocatalyst into pulsed discharge plasma process in the utilizing of ultraviolet radiation and electric field in pulsed discharge plasma process enhanced the yields of chemically active species, which were available for highly efficient removal and mineralization of organic pollutants.


Asunto(s)
Clorofenoles/química , Clorofenoles/efectos de la radiación , Titanio/química , Rayos Ultravioleta , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/efectos de la radiación , Compuestos Azo/química , Compuestos Azo/efectos de la radiación , Catálisis , Colorantes/química , Colorantes/efectos de la radiación , Electroquímica , Peróxido de Hidrógeno/análisis , Peróxido de Hidrógeno/química , Ozono/análisis , Ozono/química , Fenol/química , Fenol/efectos de la radiación , Fotoquímica , Purificación del Agua/métodos
12.
J Zhejiang Univ Sci B ; 7(4): 310-3, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16532534

RESUMEN

During the routine impurity profile of lisinopril bulk drug by HPLC (high-performance liquid chromatography), a potential impurity was detected. Using multidimensional NMR (nuclear magnetic resonance) technique, the trace-level impurity was unambiguously identified to be 2-(-2-oxo-azocan-3-ylamino)-4-phenyl-butyric acid after isolation from lisinopril bulk drug by semi-preparative HPLC. Formation of the impurity was also discussed. To our knowledge, this is a novel impurity and not reported elsewhere.


Asunto(s)
Butiratos/análisis , Contaminación de Medicamentos , Lisinopril/análisis , Butiratos/aislamiento & purificación , Espectroscopía de Resonancia Magnética , Modelos Moleculares
13.
J Zhejiang Univ Sci ; 5(12): 1548-53, 2004 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-15547963

RESUMEN

The metallo-organic chemical vapor deposition (MOCVD) technique has been applied to the preparation of the photocatalyst titanium dioxide supported on activated carbon. The effects of various condition parameters such as carrier gas flow rate, source temperature and deposition temperature on the deposition rate were investigated. The maximum deposition rate of 8.2 mg/(g x h) was obtained under conditions of carrier gas flow rate of 400 ml/min, source temperature of 423 K and deposition temperature of 913 K. The deposition rate followed Arrhenius behavior at temperature of 753 K to 913 K, corresponding to activation energy E(a) of 51.09 kJ/mol. TiO(2) existed only in anatase phase when the deposition temperature was 773 K to 973 K. With increase of deposition temperature from 1073 K to 1273 K, the rutile content sharply increased from 7% to 70%. It was found that a deposition temperature of 773 K and a higher source temperature of 448 K resulted in finely dispersed TiO(2) particles, which were mainly in the range of 10-20 nm.


Asunto(s)
Carbón Orgánico/química , Cristalización/métodos , Nanotubos/química , Nanotubos/ultraestructura , Titanio/química , Adsorción , Catálisis , Técnicas Químicas Combinatorias , Gases/química , Conformación Molecular , Tamaño de la Partícula , Polvos , Temperatura , Titanio/aislamiento & purificación
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