Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Langmuir ; 40(11): 5878-5889, 2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-38452050

RESUMEN

Shotcrete is widely used in tunnels, bridges, culverts, and other large-scale projects. The accelerator is an additive employed to expedite the setting time of shotcrete. Previous research primarily concentrated on enhancing the early strength of accelerators, whereas their long-term stability has been inadequately investigated. In this study, pseudoboehmite (PB) and amorphous aluminum hydroxide (AAH) were incorporated into the accelerator to enhance its stability over a period of 90 days without any signs of crystallization or delamination. Furthermore, the accelerator exhibited an initial setting time of 170 s, a final setting time of 550 s, and a compressive strength of 11.58 MPa after 1 day. The mechanism of effects was studied by isothermal calorimetry, FTIR, XRD, TG-DTG, and SEM analysis. The enhancement in stability is attributed to the distinctive adsorption and thixotropic properties of PB, which facilitate the formation of an electrical double-layer structure in acidic solutions. The expedited setting and hardening are primarily due to the equilibrium between Al3+, SO42-, and Ca2+ ions, which accelerates the hydration process of cement. This research offers a methodology for developing a high-performance, alkali-free liquid accelerator.

2.
Genes Nutr ; 11: 14, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27551315

RESUMEN

BACKGROUND: Environmental factors are well-known causes of diseases. However, aside from a handful of risk indicators, genes' encoding susceptibility to chronic illnesses and their associated environmental triggers are largely unknown. In this era of increasingly rich diets, such genetic predispositions would be immensely helpful from a public health perspective. The novel transgenic mouse model with liver-specific NG37 overexpression characterized in this article identifies the diet-dependent function of NG37 in the pathogenesis of fatty liver disease and cardiac arrhythmia. RESULTS: The liver-specific NG37 overexpression transgenic mouse model described here was generated using the Alb-SV40 polyA expression plasmid backbone. NG37 cDNA under control of the albumin promoter for liver-specific expression was fused with a 5' terminal M2 FLAG sequence and a SV40 early region transcription terminator/polyadenylation site attached at the 3'-UTR. These NG37 transgenic mice developed normally and were physiologically normal on a standard diet. However, in comparison to non-transgenic (nTG) litter mates, these mice develop dramatic phenotypes within 12-18 days of starting a high-fat diet: (i) increased body weight (28.5 ± 12.3 g), (ii) increased liver weight (87.4 ± 35.7 mg), (iii) increased heart weight (140 ± 38.4 mg), and (iv) cardiac arrhythmia. The enlarged livers of high-fat diet NG37 transgenic mice was histologically similar to human fatty liver disease and contained Maltese cross birefringent active depositions in hepatocytes that are indicative of fatty liver disease. We also confirmed via X-ray diffraction the steatotic vesicles in the diseased hepatocytes of our high-fat diet NG37 mice was composed of cholesteryl derivatives also found in human fatty liver disease. In addition to cardiac enlargement, NG37 transgenic mice on high-fat diet also exhibited highly irregular bradycardia not present in either high-fat diet nTG littermates or normal-diet transgenic litter mates. CONCLUSIONS: The dramatic high-fat diet-dependent symptoms (increased body weight, cardiac enlargement, fatty liver, and cardiac arrhythmias) characterized in our liver-specific NG37 overexpression mouse model identifies NG37 as a gene encoding latent lipid metabolism pathology induced only in the presence of an environmental factor relevant to human health: high-fat diet.

3.
Cell Biosci ; 3(1): 27, 2013 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-23803222

RESUMEN

Hemicentin has come a long way from when it was first identified in C. elegans as him-4 (High incidence of males). The protein is now a recognized player in maintaining the architectural integrity of vertebrate tissues and organs. Highly conserved hemicentin sequences across species indicate this gene's ancient evolutionary roots and functional importance. In mouse, hemicentin is liberally distributed on the cell surface of many cell types, including epithelial cells, endothelial cells of the eye, lung, and uterus, and trophectodermal cells of blastocyst. Recent discoveries have uncovered yet another vital purpose of hemicentin 1. The protein also serves a unique function in mitotic cytokinesis, during which this extracellular matrix protein plays a key role in cleavage furrow maturation. Though understanding of hemicentin function has improved through new discoveries, much about this protein remains mysterious.

4.
PLoS One ; 8(3): e58428, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23526983

RESUMEN

Escape from immune recognition has been hypothesized to be a factor in carcinogenesis. It may be mediated for many cancers through down-regulation in the MHC class 1 antigen processing and presentation pathway. TAP-1, TAP-2, tightly linked to LMP-2 and LMP-7 are multiple components of the endogenous, antigen presentation pathway machinery. We addressed the question of alterations in this pathway in human Glioblastoma (HGB) and of its relationship to modulation in expression of IGF-1 that is highly expressed in this cancer. Deficiencies in expression of TAP-1 were demonstrated by RT-PCR and/or by immuno-flow cytometry in the HGB cell line T98G obtained from ATCC, and in 3 of 4 human cell lines established from patients with Glioblastoma Multiforme. Deficiencies in expression of TAP-2 were observed in 3 of 4, deficiencies in expression of LMP-2 in 4 of 4 and deficiencies in LMP-7 in 3 of 4 HGB cell lines examined by RT-PCR and Western blot. Following down-regulation of IGF-1 by transfection with the pAnti IGF-1 vector that expresses IGF-1 RNA in antisense orientation, or by the exogenous addition of IGF-1 receptor monoclonal antibody to cell culture media, the deficiencies in components of the MHC-1 antigen presentation pathway were up-regulated and/or rescued in all HGB cell lines tested. Moreover, this up-regulation in expression was aborted by addition of 100 ng/ml of IGF-1 to the culture media. Unlike in the case of IFN-γ, the restoration of TAP-1 and LMP-2 by down-regulation of IGF-1 in Glioblastoma cells was not correlated to the tyrosine phosphorylation of STAT 1. In summary, the simultaneous reversion in expression of the multiple constituents of MHC-1 antigen processing path and up-regulation in expression of MHC-1 occurring with down-regulation in IGF-1 may have a role in reinforcement of immunity against tumor antigen(s) in some animal cancers and in humans with Glioblastoma Multiforme.


Asunto(s)
Presentación de Antígeno/genética , Glioblastoma/genética , Glioblastoma/inmunología , Antígenos de Histocompatibilidad Clase I/metabolismo , Factor I del Crecimiento Similar a la Insulina/genética , Transportador de Casetes de Unión a ATP, Subfamilia B, Miembro 2 , Miembro 3 de la Subfamilia B de Transportadores de Casetes de Unión a ATP , Transportadoras de Casetes de Unión a ATP/genética , Transportadoras de Casetes de Unión a ATP/metabolismo , Antígenos de Neoplasias/metabolismo , Antígeno B7-1/metabolismo , Línea Celular Tumoral , Cisteína Endopeptidasas/genética , Cisteína Endopeptidasas/metabolismo , Regulación hacia Abajo , Glioblastoma/metabolismo , Humanos , Factor I del Crecimiento Similar a la Insulina/antagonistas & inhibidores , Complejo de la Endopetidasa Proteasomal/genética , Complejo de la Endopetidasa Proteasomal/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , ARN Neoplásico/genética , ARN Neoplásico/metabolismo
5.
Chemother Res Pract ; 2012: 721873, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22400112

RESUMEN

The aim of this study was to establish the criteria for methodology of cellular "anti-IGF-I" therapy of malignant tumours and particularly for glioblastoma multiforme. The treatment of primary glioblastoma patients using surgery, radiotherapy, and chemotherapy was followed by subcutaneous injection of autologous cancer cells transfected by IGF-I antisense/triple helix expression vectors. The prepared cell "vaccines" should it be in the case of glioblastomas or other tumours, have shown a change of phenotype, the absence of IGF-I protein, and expression of MHC-I and B7. The peripheral blood lymphocytes, PBL cells, removed after each of two successive vaccinations, have demonstrated for all the types of tumour tested an increasing level of CD8(+) and CD8(+)28(+) molecules and a switch from CD8(+)11b(+) to CD8(+)11. All cancer patients were supervised for up to 19 months, the period corresponding to minimum survival of glioblastoma patients. The obtained results have permitted to specify the common criteria for "anti-IGF-I" strategy: characteristics sine qua non of injected "vaccines" (cloned cells IGF-I(-) and MHC-I(+)) and of PBL cells (CD8(+) increased level).

6.
J Ethnopharmacol ; 141(2): 647-52, 2012 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-21619922

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: As a Chinese traditional herbal medicine, leaves of Platycladus orientalis (Linnaeus) Franco (LPO) are used to treat coughs, excessive mucus secretion, chronic bronchitis, bronchiectasis, and asthma, etc. The experiments were carried out to investigate their anti-inflammatory properties and mechanisms, which could support the Chinese traditional uses of treating inflammatory airway diseases. MATERIALS AND METHODS: The anti-inflammatory activities of the chloroform fraction (CHL) and pure compounds of LPO were evaluated for their abilities to inhibit pro-inflammatory enzymes in vitro, and production of tumor necrosis factor-α (TNF-α) and nitric oxide in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Furthermore, the arachidonic acid metabolites, stimulated by calcium ionophore A23187, were also determined by HPLC. RESULTS: For the first time, the assays of eicosanoids in intact cells showed that the CHL, hinokiol, and acacetin had significant inhibitory effects on 5-hydroxy-eicosa-tetra-enoic acid (5-HETE) and leukotriene B(4) (LTB4) formations. And cell-free enzyme assays (5-lipoxygenase, leukotriene A(4)-hydrolase, cyclooxgenase-2) demonstrated the potent inhibitory effects of the CHL, hinokiol and acacetin on 5-lipoxygenase (5-LOX). Then, the inhibitions of the CHL, hinokiol on NO biosynthesis and the inhibitions of the CHL, 8(14),15-pimaradien-3ß,18-diol, and hinokiol on TNF-α release were also confirmed in the RAW264.7 murine macrophages. CONCLUSION: The data indicate that the inhibitory effects of the CHL and its components (hinokiol and acacetin) on 5-LOX contribute to the anti-inflammatory activity of LPO. Moreover, the CHL and its components also show beneficial effects on NO and TNF-α production. Consequently, these results provide a rationale for LPO's traditional applications in the treatment of inflammatory airway diseases.


Asunto(s)
Antiinflamatorios/farmacología , Cupressaceae , Medicamentos Herbarios Chinos/farmacología , Macrófagos/efectos de los fármacos , Animales , Antiinflamatorios/química , Antiinflamatorios/aislamiento & purificación , Araquidonato 5-Lipooxigenasa/metabolismo , Ácido Araquidónico/metabolismo , Calcimicina/farmacología , Ionóforos de Calcio/farmacología , Línea Celular , Cloroformo/química , Cromatografía Líquida de Alta Presión , Cupressaceae/química , Ciclooxigenasa 2/metabolismo , Relación Dosis-Respuesta a Droga , Medicamentos Herbarios Chinos/química , Medicamentos Herbarios Chinos/aislamiento & purificación , Epóxido Hidrolasas/metabolismo , Ácidos Grasos Insaturados/metabolismo , Flavonas/aislamiento & purificación , Flavonas/farmacología , Ácidos Hidroxieicosatetraenoicos/metabolismo , Mediadores de Inflamación/metabolismo , Leucotrieno B4/metabolismo , Inhibidores de la Lipooxigenasa/aislamiento & purificación , Inhibidores de la Lipooxigenasa/farmacología , Macrófagos/inmunología , Medicina Tradicional China , Ratones , Óxido Nítrico/metabolismo , Hojas de la Planta , Plantas Medicinales , Ratas , Ratas Sprague-Dawley , Solventes/química , Factor de Necrosis Tumoral alfa/metabolismo
7.
Planta Med ; 77(14): 1623-30, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21412696

RESUMEN

Four new compounds: an abietane (1), two isopimarane (2 and 3) diterpenes, and a dihydrobenzofuran neolignan (5), together with a sesquiterpene glycoside (6) firstly isolated from a natural source, and a known phenol glycoside (4) were isolated from leaves of Platycladus orientalis. The structures and relative configurations of these compounds were assigned on the basis of MS, IR, 1D and 2D NMR data. The absolute configuration of compound 1 was determined via density functional theory calculations of its electronic circular dichroism. In addition, the results of bioassays indicated that compounds 4 and 6 showed a potent inhibitory effect on NO production with IC50 values of 24.4 and 11.9 µM, respectively. Meanwhile, compounds 1, 2, and 3 moderately inhibited TNF- α release.


Asunto(s)
Cupressaceae/química , Diterpenos/farmacología , Medicamentos Herbarios Chinos/química , Lignanos/farmacología , Óxido Nítrico/biosíntesis , Factor de Necrosis Tumoral alfa/metabolismo , Animales , Línea Celular Tumoral , Diterpenos/química , Diterpenos/aislamiento & purificación , Glicósidos/química , Glicósidos/aislamiento & purificación , Glicósidos/farmacología , Lignanos/química , Lignanos/aislamiento & purificación , Lipopolisacáridos/efectos adversos , Medicina Tradicional China , Ratones , Conformación Molecular , Óxido Nítrico/antagonistas & inhibidores , Hojas de la Planta/química , Plantas Medicinales/química , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...