Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
1.
Ecotoxicology ; 24(10): 2049-53, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26419245

RESUMEN

The aim of this study was to evaluate the biological toxicity of cellulose nanocrystals (CNCs) using the constitutively bioluminescent luxCDABE-based bioreporter Escherichia coli 652T7. The effects of CNCs on E. c oli 652T7 biotoxicity were investigated at different CNC concentrations, reaction times, and IC50 values. CNC toxicity was also compared with and without ultrasonic dispersion to establish dispersibility effects. The results demonstrated that CNCs were not significantly toxic at concentrations at or below 250 mg/L. At concentrations higher than 300 mg/L, toxicity increased linearly as CNC concentrations increased up to 2000 mg/L. IC50 calculations demonstrated an increase in cytotoxicity as CNC exposure times increased, and elevated dispersibility of the CNCs were shown to increase cytotoxicity effects. These results suggest that CNCs can impact microbial populations if elevated concentration thresholds are met.


Asunto(s)
Celulosa/toxicidad , Escherichia coli/efectos de los fármacos , Nanopartículas/toxicidad , Escherichia coli/genética , Proteínas Luminiscentes/análisis , Pruebas de Toxicidad
2.
Guang Pu Xue Yu Guang Pu Fen Xi ; 32(6): 1519-25, 2012 Jun.
Artículo en Zh | MEDLINE | ID: mdl-22870631

RESUMEN

The degradability characteristics of film with 4 kinds of starch acetate coated and inhibitors amended urea were analyzed by FTIR, which was purposed to supply theoretical basis for applying starch acetate coated urea fertilizers in farming. The result showed that the chemical component, molecule structure and material form of the membrane were not changed because of adding different inhibitors to urea. The main peaks of the film degradation process were brought by the H--O, --OH, CO2, C==O, --CH2, --CH3, C--O, C--O--H and C--O--C vibrancy in asymmetry and symmetry. In brown soil, the trend of absorbing value of the most high peak was 0>15>30>60>90>120>150>310 d. The infrared spectra of 4 kinds of fertilizers were not different remarkably, and the film was comparatively slowly degraded before 15 d. But a majority of the film had been already degraded after 150 days. The main components of film materials were degraded fastest in 310 days. The speed of film degradation wasn't more impacted by different inhibitors. The characteristic of starch acetate film degradation may be monitored entirely and degradation speed difference of the film could be represented through infrared spectrum.

3.
Guang Pu Xue Yu Guang Pu Fen Xi ; 32(3): 635-41, 2012 Mar.
Artículo en Zh | MEDLINE | ID: mdl-22582622

RESUMEN

The degradability characteristics of film with 4 kinds of methyl methacrylate coated urea amended with inhibitors were analyzed by FITR, which was purposed to supply theoretical basis for applying the FITR analysis method to film decomposition and methyl methacrylate coated urea fertilizers on farming. The result showed that the chemical component, molecule structure and material form of the membrane were not changed because of adding different inhibitors to urea. the main peaks of expressing film degradation process were brought by the -C-H of CH3 & CH2, -OH, C-O, C-C, C-O-C, C=O, C=C flexing vibrancy in asymmetry and symmetry in 3 479-3 195, 2 993--2 873, 1 741-1 564, 1 461-925 and 850-650 cm(-1). The peak value changed from smooth to tip, and from width to narrow caused by chemical structural transform of film The infrared spectrum of 4 kinds of fertilizers was not different remarkably before 60 days, and the film was slowly degraded. But degradation of the film was expedited after 60 days, it was most quickened at 120 day, and the decomposition rate of film was decreased at 310 day. The substantiality change of film in main molecule structure of 4 kinds of fertilizers didn't happen in 310 days. The main component of film materials was degraded most slowly in brown soil. The speed of film degradation wasn't heavily impacted by different inhibitors. The characteristic of film degradation may be monitored entirely by infrared spectrum. The degradation dynamic, chemical structure change, degradation speed difference of the film could be represented through infrared spectrum.

4.
Biomaterials ; 266: 120432, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33069116

RESUMEN

Gastrointestinal (GI) cancers are among the most lethal malignancies. The treatment of advanced-stage GI cancer involves standard chemotherapeutic drugs, such as docetaxel, as well as targeted therapeutics and immunomodulatory agents, all of which are only moderately effective. We here show that Π electron-stabilized polymeric micelles based on PEG-b-p(HPMAm-Bz) can be loaded highly efficiently with docetaxel (loading capacity up to 23 wt%) and potentiate chemotherapy responses in multiple advanced-stage GI cancer mouse models. Complete cures and full tumor regression were achieved upon intravenously administering micellar docetaxel in subcutaneous gastric cancer cell line-derived xenografts (CDX), as well as in CDX models with intraperitoneal and lung metastases. Nanoformulated docetaxel also outperformed conventional docetaxel in a patient-derived xenograft (PDX) model, doubling the extent of tumor growth inhibition. Furthermore, micellar docetaxel modulated the tumor immune microenvironment in CDX and PDX tumors, increasing the ratio between M1-and M2-like macrophages, and toxicologically, it was found to be very well-tolerated. These findings demonstrate that Π electron-stabilized polymeric micelles loaded with docetaxel hold significant potential for the treatment of advanced-stage GI cancers.


Asunto(s)
Antineoplásicos , Neoplasias Gastrointestinales , Animales , Antineoplásicos/uso terapéutico , Línea Celular Tumoral , Docetaxel , Portadores de Fármacos , Electrones , Neoplasias Gastrointestinales/tratamiento farmacológico , Ratones , Micelas , Polietilenglicoles , Microambiente Tumoral
5.
Bioresour Technol ; 280: 502-504, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30777701

RESUMEN

For bio-H2 fermentation, the progress and H2 yield were significantly affected by culture pH. Our previous research found peanut shell powder (PSP, as supplementary substrate) having a buffer effect on the fermentative time prolongation and H2 yield enhancement. The acid buffer action (ABA), cation exchange capacity (CEC), scanning electron microscope (SEM) and X-ray powder diffraction (XRD) were employed to explore the mechanism and structure changes of PSP. The superior ABA (57.44 ±â€¯0.65 mmol/pH-kg) and CEC (112 ±â€¯2.0 cmol/kg) of PSP, which provided high specific surface area and amorphous content, prolonged the fermentative time. The acidification of volatile fatty acids on PSP was effective to release reducing sugar and enhance hydrogen yield through breaking hemicellulose and amorphous components of cellulose, and enlarging specific surface area. The results indicated that buffer effect and acidification on PSP made positive effects on prolonging fermentation time and enhancing hydrogen yield.


Asunto(s)
Arachis/metabolismo , Fermentación , Hidrógeno/metabolismo , Ácidos , Arachis/anatomía & histología , Tampones (Química) , Celulosa/metabolismo , Ácidos Grasos Volátiles/química , Ácidos Grasos Volátiles/metabolismo , Concentración de Iones de Hidrógeno , Especificidad por Sustrato
6.
Artif Cells Nanomed Biotechnol ; 47(1): 4211-4221, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31713444

RESUMEN

At present, cancer is the first cause of death for humans, but early detection and treatment can help improve prognoses and reduce mortality. However, further development of carrier-assistant drug delivery systems (DDSs) is retarded by the aspects such as the low drug-carrying capacity, carrier-induced toxicity and immunogenicity, complex synthesis manipulation. The development of nanoscale drug delivery systems (NDDS) have been rapidly developed to address these issues. In this article, we used PLGA-PEG with good biocompatibility to encapsulate Fe3O4 nanoparticles (a magnetic resonance imaging contrast agent) and DOX (an antitumour drug) via the emulsion-solvent evaporation method, aimed at achieving a dual function of the early detection and the treatment of mammary cancer. The results showed that the Fe3O4/DOX/PLGA-PEG nanoparticles had a relatively uniform size, a high carrier rate of Fe3O4 and high encapsulation efficiency of DOX, and a relatively high activity of released DOX within 120 h. In addition, in vitro studies showed that the Fe3O4/DOX/PLGA-PEG nanoparticles were cytocompatibility in NIH 3T3 fibroblast cells culture study while had a special effect on destroying human breast cancer MCF-7 cells compared with pure DOX solution. In vitro studies revealed that the Fe3O4/DOX/PLGA-PEG enabled enhanced T2 contrast magnetic resonance. Overall, our multifunctional Fe3O4/DOX/PLGA-PEG nanoparticles, composed of biocompatible substances and therapeutic/imaging materials, have great potential for the early detection of cancer and accurate drug delivery via the dynamic monitoring using MRI.


Asunto(s)
Materiales Biocompatibles/química , Doxorrubicina/química , Doxorrubicina/uso terapéutico , Portadores de Fármacos/química , Detección Precoz del Cáncer , Nanopartículas de Magnetita/química , Poliésteres/química , Polietilenglicoles/química , Células 3T3 , Animales , Materiales Biocompatibles/metabolismo , Transporte Biológico , Cápsulas , Portadores de Fármacos/metabolismo , Liberación de Fármacos , Imagen por Resonancia Magnética , Ratones , Tamaño de la Partícula , Solventes/química
7.
Anat Rec (Hoboken) ; 301(6): 1061-1067, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29316384

RESUMEN

Breast cancer is the most common malignant tumor among women, and the incidence and mortality of breast cancer has rapidly increased in recent years. Studies have indicated that high mobility group A1 (HMGA1), an important member of the HMGA family, plays a role in the pathogenesis and progression of malignant tumors, including breast cancer. This study aims to evaluate the effect of HMGA1 in breast cancer. Interestingly, we found that HMGA1 expression was significantly higher in breast cancer tissues than in adenoma tissues and closely correlated with the clinical stage and histological grade in breast cancer patients. Further study showed that HMGA1 knockdown inhibited the proliferation and migration of breast cancer cells. Thus, the results demonstrated that HMGA1 could act as an independent prognostic indicator in breast cancer. HMGA1 expression was closely correlated with the clinical stage, histological grade, and tumor size in breast cancer patients and breast cancer progression in transgenic MMTV-PyMT mice. Anat Rec, 301:1061-1067, 2018. © 2018 Wiley Periodicals, Inc.


Asunto(s)
Neoplasias de la Mama/metabolismo , Proteína HMGA1a/metabolismo , Invasividad Neoplásica/patología , Animales , Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/patología , Línea Celular Tumoral , Proliferación Celular/fisiología , Supervivencia Celular/fisiología , Progresión de la Enfermedad , Femenino , Humanos , Ratones , Pronóstico
8.
J Hazard Mater ; 329: 222-229, 2017 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-28178637

RESUMEN

Thermal activated serpentine with high adsorption capacity for heavy metals was prepared. The batch experiment studies were conducted to evaluate the adsorption performance of Cd2+ in aqueous solution using thermal activated serpentine as adsorbent. These samples before and after adsorption were characterized by XRD, FT-IR, SEM, XPS, and N2 adsorption-desorption at low temperature. It was found that serpentine with layered structure transformed to forsterite with amorphous structure after thermal treatment at over 700°C, while the surface area of the samples was increased with activated temperature and the serpentine activated at 700°C (S-700) presented the largest surface area. The pH of solution after adsorption was increased in different degrees due to hydrolysis of MgO in serpentine, resulting in enhancing adsorption of Cd2+. The S-700 exhibited the maximum equilibrium adsorption capacity (15.21mg/g), which was 2 times more than pristine serpentine. Langmuir isotherm was proved to describe the equilibrium adsorption data better than Freundlich isotherm and pseudo second order kinetics model could fit the adsorption kinetics processes well. Based on the results of characterization with XPS and XRD, the adsorption mechanisms could be explained as primarily formation of CdCO3 and Cd(OH)2 precipitation on the surface of serpentine.

9.
Chin Med J (Engl) ; 130(17): 2069-2075, 2017 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-28836550

RESUMEN

BACKGROUND: It remains controversial whether patients with Stage II colorectal cancer would benefit from adjuvant chemotherapy after radical resection. The aim of this study was to establish two mathematical models to identify the suitable patients for adjuvant chemotherapy. METHODS: The current study comprised of two steps. In the first step, 353 patients with Stage II colorectal cancer who underwent surgical procedures at the Third Affiliated Hospital of Sun Yat-sen University between June 2006 and December 2015 were entered and followed up for 6-120 months. Their clinical data were collected and enrolled into the database. We established two mathematical models by univariate and multivariate Cox regression analysis to identify the target patients; in the second step, 230 patients under the same standard between January 2012 and December 2016 were entered and followed up for 3-62 months to verify the two models' validation. RESULTS: In the first step, totally 340 surgical patients with Stage II colorectal cancer were finally enrolled in this study. Statistical analysis showed that tumor differentiation (TD) (P < 0.001), lymphovascular invasion (LVI) (P < 0.001), uncertain or positive margins (UPM) (P < 0.001), and fewer lymph nodes (LNs) (<12) retrieved (P < 0.001) were correlated with the overall survival (OS) and disease free survival (DFS). We obtained two models: (1) OS risk score = 1.116 × TD + 2.202 × LVI + 3.676 × UPM + 1.438 × LN - 0.493; (2) DFS risk score = 0.789 × TD + 2.074 × LVI + 3.183 × UPM + 1.329 × LN - 0.432. According to the models and cutoff points [(0.07, 1.33) and (-0.04, 1.30), respectively], patients can be divided into three groups: low-risk, moderate-risk, and high-risk. Moreover, the high-risk group patients could benefit from adjuvant chemotherapy. In the second step, totally 221 patients were finally used to verify the models' validation. The results proved that the models were accurate and feasible (P< 0.05). CONCLUSIONS: According to the predictive models, patients with Stage II colorectal cancer in the high-risk group are strongly recommended for adjuvant chemotherapy, thus facilitating the individualized and precise treatment.


Asunto(s)
Quimioterapia Adyuvante/métodos , Neoplasias Colorrectales/tratamiento farmacológico , Modelos Teóricos , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Factores de Riesgo
10.
Int J Biol Sci ; 13(11): 1450-1457, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29209148

RESUMEN

Some solid tumors are characterized by extracellular matrix (ECM) remodeling and stiffening, which is related to solid tumor progression and aggression. However, the relationship between ECM stiffness and colorectal cancer (CRC) remains unclear. In this study, we investigated the relevance of ECM stiffness to clinicopathologic features using human CRC tissue microarrays. The results demonstrate that the expression of ECM components in CRC tissues is closely correlated with CRC progression and poor prognosis, which indicates that ECM stiffness may be associated with CRC development. We further studied lysyl oxidase (LOX) expression in CRC tissue and demonstrated that LOX expression is closely correlated with CRC progression. Previous studies showed that P-selectin-mediated platelet accumulation in CRC tissue may up-regulate LOX expression. Our findings indicate that P-selectin-mediated platelet aggregation may up-regulate LOX expression and enhance the remodeling and stiffening of the tumor ECM, which may promote the progression of colorectal cancer. Therefore, LOX may be a potential effective therapeutic target to treat colorectal cancer.


Asunto(s)
Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Matriz Extracelular/metabolismo , Proteína-Lisina 6-Oxidasa/metabolismo , Western Blotting , Colágeno Tipo I/genética , Colágeno Tipo I/metabolismo , Progresión de la Enfermedad , Matriz Extracelular/patología , Humanos , Inmunohistoquímica , Selectina-P/genética , Selectina-P/metabolismo , Proteína-Lisina 6-Oxidasa/genética , Análisis de Matrices Tisulares
11.
Huan Jing Ke Xue ; 36(4): 1437-44, 2015 Apr.
Artículo en Zh | MEDLINE | ID: mdl-26164924

RESUMEN

The test simulated exogenous Cd contaminated soil indoors, and studied separate application of potassium dihydrogen phosphate, diammonium hydrogen phosphate and zeolite, and combined application of zeolite and dipotassium hydrogen phosphate, zeolite and diammonium hydrogen phosphate, as well as the effect on the morphological changes of Cd contaminated soil. The results showed that soil exchangeable Cd contents were reduced in different degrees after the application of different modifiers, and the carbonate bound and Fe-Mn oxide bound, organic bound and residual Cd contents increased. By comparison, the separate application of potassium dihydrogen phosphate, diammonium hydrogen phosphate and zeolite, and the combined application of zeolite and dipotassium hydrogen phosphate, zeolite and diammonium hydrogen phosphate respectively reduced the soil available Cd contents at 25.2% -51.7%, 21.6% - 46.8%, 6.4% - 23.2%, 38.6% - 61.4%, and 34.1% - 56.4%. All treatments could increase the soil available phosphorus contents, making the soil available phosphorus contents negatively correlated with the available Cd contents significantly, with the correlation coefficient r = - 0.902 6, and the soil pH values had a negative correlation with the available Cd content during the treatments. Therefore, it could be known that the changes of soil available phosphorus contents were the major factor in reducing the availability of soil cadmium under the conditions of the application of phosphate and natural zeolite.


Asunto(s)
Cadmio/química , Fósforo/química , Suelo/química , Zeolitas/química , Óxidos , Fosfatos , Compuestos de Potasio , Contaminantes del Suelo
12.
Ying Yong Sheng Tai Xue Bao ; 17(5): 831-4, 2006 May.
Artículo en Zh | MEDLINE | ID: mdl-16883810

RESUMEN

The study showed that on a sheltered vegetable field, a long-term application of organic plus chemical fertilizers induced a higher content of loosely combined soil humus than applying chemical fertilizers alone, while there was no significant difference in firmly combined humus content among different fertilization treatments. More tightly combined humus was observed in organic fertilizer treatments than in chemical fertilizer treatments, and the highest content (11.53 g x kg(-1)) was in the treatment of organic fertilizer plus chemical NPK. The ratio of loosely/tightly combined humus tended to decrease after a long-term application of organic fertilizer, being the lowest (1.10) in the treatment of organic fertilizer plus chemical NPK.


Asunto(s)
Fertilizantes , Sustancias Húmicas/análisis , Suelo/análisis , Verduras/crecimiento & desarrollo
13.
Ying Yong Sheng Tai Xue Bao ; 17(6): 1055-9, 2006 Jun.
Artículo en Zh | MEDLINE | ID: mdl-16964940

RESUMEN

With pot experiment and simulating field ecological environment, this paper studied the effects of different slow/ controlled release N fertilizers on the soil nitrate - reductase and urease activities and microbial biomass C and N at maize seedling stage. The results showed that granular urea amended with dicyandiamide (DCD) and N-(n-bultyl) thiophosphoric triamide (NBPT) induced the highest soil nitrate-reductase activity, granular urea brought about the highest soil urease activity and microbial biomass C and N, while starch acetate (SA)-coated granular urea, SA-coated granular urea amended with DCD, methyl methacrylate (MMA) -coated granular urea amended with DCD, and no N fertilization gave a higher soil urease activity. Soil microbial C and N had a similar variation trend after applying various kinds of test slow/controlled release N fertilizers, and were the lowest after applying SA-coated granular urea amended with DCD and NBPT. Coated granular urea amended with inhibitors had a stronger effect on soil biological activities than coated granular urea, and MMA-coating had a better effect than SA-coating.


Asunto(s)
Fertilizantes , Plantones/crecimiento & desarrollo , Suelo/análisis , Urea/análisis , Zea mays/crecimiento & desarrollo , Nitratos/análisis , Nitrógeno/análisis , Oxidorreductasas/metabolismo , Ureasa/metabolismo
14.
Ying Yong Sheng Tai Xue Bao ; 15(8): 1334-8, 2004 Aug.
Artículo en Zh | MEDLINE | ID: mdl-15573983

RESUMEN

The effect of long-term fertilization on the dynamics of microbial biomass C in a typical black soil of Northeastern China was studied in a field trail treated by different fertilizations. The results showed that the amount of soil microbial biomass C under different fertilizations varied significantly with growth stages. It was the highest in farmyard manure (M2 and M4) treatments, with a less seasonal fluctuation, second in NPK treatment, the peak at sowing period, and the lowest in CK, the peak at wax maturity stage. No significant correlation was found between the dynamic changes of soil microbial biomass C and soil biological, physical and chemical properties in all treatments, but the correlation of soil microbial biomass C with the contents of N, P and K in plants and that of crude protein in grain was significantly positive.


Asunto(s)
Carbono/análisis , Productos Agrícolas/crecimiento & desarrollo , Microbiología del Suelo , Suelo/análisis , Recuento de Colonia Microbiana , Fertilizantes/efectos adversos
15.
Ying Yong Sheng Tai Xue Bao ; 15(10): 1891-6, 2004 Oct.
Artículo en Zh | MEDLINE | ID: mdl-15624830

RESUMEN

This paper studied the dynamics of microbial biomass N in a black soil long-term fertilized with farmyard manure (M2 and M4) and chemical fertilizer (NPK) during crop growth season. The results showed that the soil microbial biomass N was 25.52-239.12 mg x kg(-1) in M4, 10.40-94.31 mg x kg(-1) in M2, 6.27-87.04 mg x kg(-1) in NPK, and 9.15-69.81 mg x kg(-1) in CK. In same treatment, the highest value was 7-14 times higher than the lowest value. Treatments NPK and M2 had the highest value of microbial biomass N at reproductive growth stage, while M4 and CK had it at vegetative growth stage. The significant difference of soil microbial biomass N caused by different treatments was not changed with plant growth stages. The dynamics of soil microbial biomass N had a significant correlation some soil biological, physical and chemical properties. A significant positive correlation was found between soil microbial biomass N and soil biological, physical and chemical properties, plant N, P and K contents, soil moisture, and grain crude protein.


Asunto(s)
Fertilizantes , Nitrógeno/análisis , Nitrógeno/metabolismo , Microbiología del Suelo , Suelo/análisis , China , Productos Agrícolas/crecimiento & desarrollo , Ecosistema , Factores de Tiempo
16.
Ying Yong Sheng Tai Xue Bao ; 15(10): 1897-902, 2004 Oct.
Artículo en Zh | MEDLINE | ID: mdl-15624831

RESUMEN

This paper studied the microbial biomass P in a long-term fertilized black soil. The soil was fertilized by farmyard manure (M2, M4) and chemical fertilizer (NPK), and the dynamics of soil microbial biomass P was monitored during crop growth season. The results showed that the microbial biomass P in different treatments was 8.75-47.68 mg x kg(-1) (M4), 3.02-37.16 mg x kg(-1) (M2), 1.59-10.62 mg x kg(-1) (NPK), and 0.76-6.74 mg x kg(-1) (CK). The microbial biomass P in M4 and M2 was the highest at reproductive growth stage, and that in NPK and CK was the highest at early growth stage. The significant difference of soil microbial biomass P induced by different amounts and types of fertilizer application was not varied with the period and stage of plant growth. In all treatments, no significant correlation was found between the dynamics of soil microbial biomass P and the soil biological, physical and chemical properties in plant growth period. Soil microbial biomass P had a very significant positive correlation with soil biological, physical and chemical properties (expect K), and a significant positive correlation with the N, P and K contents of plants and soil water content.


Asunto(s)
Fertilizantes , Fósforo/análisis , Fósforo/metabolismo , Microbiología del Suelo , Suelo/análisis , China , Productos Agrícolas/crecimiento & desarrollo , Ecosistema , Factores de Tiempo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA