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1.
J Anim Physiol Anim Nutr (Berl) ; 106(4): 813-824, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34448260

RESUMO

This study investigated the effects of citrus extract on growth, carcass and meat quality of Duroc × Landrace × Large White pigs. One hundred and eight pigs (54 barrows, 54 females) were assigned to one of three dietary treatments for 138 days. The dietary treatments were (1) basic diet; (2) basic diet supplemented with 75 mg/kg chlortetracycline; and (3) basic diet supplemented with citrus extract (0.25 ml/kg during 56-112 days of age and 0.20 ml/kg during 113-194 days of age). No significant differences among treatments were found for growth performance, carcass characteristics, meat quality and free amino acids (p > 0.05). Feeding citrus extract tended to increase intramuscular fat (p = 0.052). Citrus extract and chlortetracycline increased C15:0 concentration (p = 0.016) and superoxide dismutase activity (p = 0.004). The pigs that received chlortetracycline exhibited the lowest (p = 0.033) muscle malondialdehyde concentration. Overall, citrus extract ameliorated some meat quality indicators without adverse effects on pig growth or carcass performance.


Assuntos
Clortetraciclina , Citrus , Ração Animal/análise , Animais , Composição Corporal , Clortetraciclina/farmacologia , Dieta/veterinária , Feminino , Carne/análise , Suínos
2.
Int Rev Immunol ; 41(1): 4-18, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34304685

RESUMO

Metabolite lactic acid has always been regarded as a metabolic by-product rather than a bioactive molecule. Recently, this view has changed since it was discovered that lactic acid can be used as a signal molecule and has novel signal transduction functions both intracellular and extracellular, which can regulate key functions in the immune system. In recent years, more and more evidence has shown that lactic acid is closely related to the metabolism and polarization of macrophages. During inflammation, lactic acid is a regulator of macrophage metabolism, and it can prevent excessive inflammatory responses; In malignant tumors, lactic acid produced by tumor tissues promotes the polarization of tumor-associated macrophages, which in turn promotes tumor progression. In this review, we examined the relationship between lactic acid and macrophage metabolism. We further discussed how lactic acid plays a role in maintaining the homeostasis of macrophages, as well as the biology of macrophage polarization and the M1/M2 imbalance in human diseases. Potential methods to target lactic acid in the treatment of inflammation and cancer will also be discussed so as to provide new strategies for the treatment of diseases.


Assuntos
Ácido Láctico , Neoplasias , Humanos , Inflamação , Ácido Láctico/metabolismo , Ativação de Macrófagos , Macrófagos , Neoplasias/metabolismo , Transdução de Sinais
3.
Front Bioeng Biotechnol ; 9: 811287, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34938726

RESUMO

The value-added utilization of tobacco stalk lignin is the key to the development of tobacco stalk resources. However, the serious heterogeneity is the bottleneck for making full use of tobacco stalk lignin. Based on this, lignin was separated from tobacco stalk through hydrothermal assisted dilute alkali pretreatment. Subsequently, the tobacco stalk alkaline lignin was fractionated into five uniform lignin components by sequential solvent fractionation. Advanced spectral technologies (FT-IR, NMR, and GPC) were used to reveal the effects of hydrothermal assisted dilute alkali pretreatment and solvent fractionation on the structural features of tobacco stalk lignin. The lignin fractions extracted with n-butanol and ethanol had low molecular weight and high phenolic hydroxyl content, thus exhibiting superior chemical reactivity and antioxidant capacity. By contrast, the lignin fraction extracted with dioxane had high molecular weight and low reactivity, nevertheless, the high residual carbon rate made it suitable as a precursor for preparing carbon materials. In general, hydrothermal assisted dilute alkali pretreatment was proved to be an efficient method to separate lignin from tobacco stalk, and the application of sequential solvent fractionation to prepare lignin fractions with homogeneous structural features has specific application prospect.

4.
J Food Biochem ; 45(10): e13889, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34426988

RESUMO

In the present study, the anti-inflammatory effect of Lycium barbarum polysaccharide (LBP) and the possible molecular mechanism thereof were examined, so as to perceive the pharmacological action of LBP. With acute peritonitis in mice as the inflammatory model, the protective effect of LBP on peritonitis mice was evaluated by recording the effect of behavioral scores, studying the pathological damage of intestine and liver, and detecting the levels of inflammatory cytokines. Additionally, by establishing an lipopolysaccharide (LPS)-induced RAW264.7 macrophage model, the effect of LBP on RAW264.7 cell phenotype and culture supernatant inflammatory markers was observed. Finally, the activation of inflammation-related target genes, such as iNOS, Toll-like receptor 4 (TLR4), nuclear factor-κB (NF-κB) p65, and IκBα, were further detected. The results reveal that pretreatment with LBP could decrease the behavioral score of inflammatory mice, inhibit the secretion of pro-inflammatory factors, and reduce liver and intestine injury. LBP can regulate the effect of lipopolysaccharide on the polarization of RAW264.7 cells, and reduce the production of NO and cytokines (TNF-α, IL-1ß, IL-6). Further, LBP pretreatment was found to be able to significantly reduce the expression of iNOS, TLR4, NF-κB p65, and IκBα in macrophages. The present research provides evidence that LBP exerts potential anti-inflammatory activity in LPS-induced RAW264.7 macrophages via inhibiting TLR4 and NF-κB inflammatory sites and improving the behavior score of peritonitis mice. PRACTICAL APPLICATIONS: In recent years, the number of deaths worldwide has continued to rise as a result of inflammation. Despite said rise in deaths, many synthetic drugs with anti-inflammatory properties are significantly expensive and also have a host of side effects. Thus, the development of new anti-inflammatory drugs derived from medicinal plants has broad application potential. As such, in the present study, lipopolysaccharide (LPS)-induced macrophages were used to establish inflammatory cell models to verify the anti-inflammatory effect of Lycium barbarum polysaccharides (LBP). Findings were made that LBP could reduce the expression levels of inflammatory cytokines and NO by regulating macrophage polarization and NF-κB translocation, and thus, could exert anti-inflammatory activity. In addition, by intraperitoneal injection of LPS to establish peritonitis mice models, LBP pretreatment was found to have significantly modified the behavioral score of mice, while decreasing the secretion of inflammatory factors and the damage to several organs. The present study provides a basis for further understanding the effects of LBP in acute inflammation.


Assuntos
Lycium , Peritonite , Animais , Medicamentos de Ervas Chinesas , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Lipopolissacarídeos/toxicidade , Camundongos , Peritonite/induzido quimicamente , Peritonite/tratamento farmacológico
5.
J Food Biochem ; 45(5): e13722, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33855723

RESUMO

This study aimed to examine the role of Zizyphus jujuba cv. Muzao polysaccharides (ZJPs) in protecting intestinal barrier function and the survival of septic mice. The sepsis mouse model was generated through cecal ligation and puncture (CLP) to observe the effect of ZJPs on the function of the intestinal barrier in the context of sepsis. We observed the clinical symptoms and survival time of the mice and evaluated serum inflammatory cytokines, intestinal pathological changes and intestinal permeability. Moreover, tight junction (TJ) proteins and apoptosis-associated proteins in intestinal tissue were examined. Finally, TLR4/NF-κB pathway-related proteins were measured in all groups. The results showed that pretreatment with ZJPs improved clinical and histological scores and reduced intestinal barrier permeability, and the levels of proinflammatory factors were decreased. Pretreatment with ZJPs also upregulated the levels of TJ proteins and downregulated the expression of proapoptotic proteins. Moreover, the activation of TLR4/NF-κB signaling was partly inhibited in septic mice by ZJPs pretreatment. The current study provides evidence that ZJPs have the potential to protect intestinal barrier function and improve the survival of septic mice via the attenuation of TLR4/NF-κB inflammatory signaling. PRACTICAL APPLICATIONS: This study reports the potential protective effect of ZJPs against cecal ligation and puncture (CLP)-induced sepsis. Our data reveal that CLP induced damage to the gut mucosal barrier, inflammation, and apoptosis in intestinal tissues. However, pretreatment with ZJPs improved clinical and histological scores, reduced intestinal barrier permeability, and decreased the levels of proinflammatory factors in mice. Pretreatment with ZJPs also upregulated the levels of TJ proteins and downregulated the expression of proapoptotic proteins. Moreover, the activation of TLR4/NF-κB signaling was partly inhibited in septic mice after ZJPs pretreatment. These findings provide evidence that pretreatment with ZJPs has the potential to attenuate CLP-induced gut damage in mice by restraining inflammation and apoptosis via the attenuation of NF-κB signaling. It provides a basis for further study of ZJPs in sepsis.


Assuntos
Sepse , Ziziphus , Animais , Mucosa Intestinal , Camundongos , NF-kappa B , Polissacarídeos/farmacologia , Polissacarídeos/uso terapêutico , Sepse/tratamento farmacológico
6.
Asian Pac J Cancer Prev ; 16(9): 3893-900, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25987056

RESUMO

It's known that having multiple sexual partners is one of the risk factors of human papillomavirus (HPV) infection which is a major cause of cervical cancer. However, it is not clear whether the number of sexual partners is an independent risk factor for cervical cancer. We identified relevant studies by searching the databases of MEDLINE, PubMed and ScienceDirect published in English from January 1980 to January 2014. We analyzed those studies by combining the study-specific odds ratios (ORs) using random-effects models. Forty-one studies were included in this meta-analysis. We observed that the number of sexual partners was associated with the occurrence of non-malignant cervical disease (OR=1.82, 95%CI 1.63-2.00) and invasive cervical carcinoma (OR=1.77, 95%CI 1.50-2.05). Subgroup analyses revealed that the association remained significant after controlling for HPV infection (OR=1.52, 95%CI 1.21-1.83 for non-malignant disease; OR=1.53, 95%CI 1.30- 1.76 for invasive cervical carcinoma). We found that there was a non-linear relation of the number of sexual partners with both non-malignant cervical disease and invasive cervical carcinoma. The risk of both malignant and non-malignant disease is relatively stable in women with more than 4-7 sexual partners. Furthermore, the frequency-risk of disease remained significant after controlling for HPV infection.The study suggested that having multiple sexual partners, with or without HPV infection, is a potential risk factor of cervical cancer.


Assuntos
Estudos Epidemiológicos , Comportamento Sexual , Parceiros Sexuais , Neoplasias do Colo do Útero/etiologia , Feminino , Humanos , Prognóstico , Fatores de Risco
7.
Langmuir ; 28(42): 14845-8, 2012 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-23046108

RESUMO

Metal nanocrystals with high-index facets (HIFs) have drawn significant attention for their superior catalysis activity compared to that of low-index faces. However, because of the high surface energy of HIFs, it is still challenging to preserve HIFs during the growth of nanocrystals. In this study, highly selective Pt concave nanocubes (CNCs) with high-index {hk0} facets have been successfully prepared in a simple aqueous solution. The vital role of glycine as the surface controller in the formation of CNCs was demonstrated. These Pt CNCs exhibited enhanced specific activities toward the electro-oxidation of methanol and formic acid in comparison to commercial Pt black and Pt/C catalysts.


Assuntos
Glicina/química , Nanopartículas Metálicas/química , Platina/química , Catálise , Técnicas Eletroquímicas , Tamanho da Partícula , Propriedades de Superfície
8.
Nanoscale ; 4(8): 2633-9, 2012 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-22402765

RESUMO

Pt-Pd bimetallic alloy nanostructures with highly selective morphologies such as cube, bar, flower, concave cube, and dendrite have been achieved through a facile one-pot solvothermal synthesis. The effects of shape-controllers (sodium dodecyl sulfate (SDS), ethylenediamine-tetraacetic acid disodium salt (EDTA-2Na), NaI) and solvents (water/DMF) on the morphologies were systematically investigated. The electrocatalytic activities of these Pt-Pd alloy nanostructures toward formic acid oxidation were tested. The results indicated that these alloy nanocrystals exhibited enhanced and shape-dependent electrocatalytic activity toward formic acid oxidation compared to commercial Pt black and Pt/C catalysts.

9.
Chemistry ; 18(9): 2639-45, 2012 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-22282407

RESUMO

Palladium is a key catalyst invaluable to many industrial processes and fine-chemical synthesis. Although recent progress has allowed the synthesis of Pd nanoparticles with various shapes by using different techniques, the facile synthesis of Pd nanocrystals and turning them into a highly active, selective, and stable catalyst systems still remain challenging. Herein, we report the highly selective one-pot synthesis of monodisperse Pd cluster nanowires in aqueous solution; these consist of interconnected nanoparticles and may serve as highly active catalysts because of the enrichment of high index facets on the surface, including {443}, {331}, and {221} steps. For the first time, carbon nanotube and γ-Al(2)O(3) immobilized Pd cluster nanowires showed highly enhanced catalytic performance in the liquid-phase selective hydrogenation of cinnamaldehyde and gas-phase hydrogenation of 1,3butadiene relative to immobilized Pd icosahedra and nanocubes, as well as commercial Pd catalysts.


Assuntos
Nanopartículas/química , Nanofios/química , Paládio/química , Catálise , Hidrogenação , Nanotecnologia , Propriedades de Superfície
10.
Chem Soc Rev ; 40(7): 3802-23, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21412560

RESUMO

This critical review provides a critical discussion of the current state of knowledge of the key factors influencing the solubility of gases in ionic liquids (ILs), including sample purity, experimental methodology, "molecular" characteristics of ILs, temperature and pressure. The review starts with a brief introduction to the current developments and the existing problems in the studies of the gas solubility in ILs. Then, the experimental, computational and theoretical developments in conformational equilibria of ions, in nanosegregated polar and nonpolar domains in ILs, and in the mechanisms for dissolution of gases in ILs are discussed and subsequently collaborated together with our freeze-fracture transmission electron microscopic and Raman measurements to propose the new microscopic mechanism for dissolving the gases in ILs. Next, a critical and quantitative analysis of the influences of the sample purity and the experimental methodology on the gas solubility is made so that the "real" relationships between structure and solubility property can be revealed. In addition, a systematic and deeper understanding of how the "molecular" features of the ILs, the temperature, and the pressure influence the gas solubility is provided at the molecular level. In the section of concluding remarks, the comments are made on the molecular criteria for the future design of the ILs to enhance the gas solubility by specifically optimizing the molecular characteristics of the ILs (265 references).

11.
Chem Asian J ; 5(6): 1425-38, 2010 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-20397254

RESUMO

Polynorbornenes appended with porphyrins containing a range of different linkers are synthesized. The use of bisamidic chiral alanine linkers between the pending porphyrins and the polymeric backbone has been shown to bring the adjacent porphyrin chromophores to more suitable orientation for exciton coupling owing to hydrogen bonding between the adjacent linkers. The hydrogen bonding between the adjacent pendants in these polymers may induce a cooperative effect and therefore render single-handed helical structures for these polymers. Such a cooperative effect is reflected in the enhancement of FRET efficiencies between zinc-porphyrin and free base porphyrin in random copolymers.


Assuntos
Plásticos/química , Plásticos/síntese química , Porfirinas/química , Porfirinas/síntese química , Alanina , Dicroísmo Circular , Transferência de Energia , Transferência Ressonante de Energia de Fluorescência , Ligação de Hidrogênio , Espectroscopia de Ressonância Magnética , Metaloporfirinas/química , Modelos Moleculares , Polímeros/síntese química
12.
Chemistry ; 15(23): 5719-28, 2009 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-19388027

RESUMO

Six different kinds of coherently aligned porphyrin-appended polynorbornenes derived from 5,6-endo-fused N-arylpyrrolidenonorbornenes have been synthesized. Pi-pi interactions between the pendant groups are essential for dictating the photophysical properties of the polymers and the mechanism for the stereoselective formation of polymers. Splitting of the Soret band of polymers 2a-c, which have alkyl-substituted porphyrin pendant groups, suggests strong exciton coupling between chromophores. No splitting of the Soret band is observed for polymers 2d-f, which have tetraaryl substituents on the porphyrin moiety. Significant fluorescence quenching is found in polymers 2a-e, whereas only slightly reduced quantum yield is observed for 2f. Time-resolved fluorescence measurements also indicate a similar trend. The AFM image of 2d on graphite shows aggregation to form a two-dimensional, ordered pattern.


Assuntos
Plásticos/síntese química , Porfirinas/síntese química , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Estrutura Molecular , Fotoquímica , Plásticos/química , Porfirinas/química , Relação Estrutura-Atividade
13.
Chem Asian J ; 2(6): 764-74, 2007 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-17458917

RESUMO

Two dimers and a series of polymers with 5,6-endo pendant aryl groups that contain different substituents at the para positions were synthesized. The conformation and stereochemistry of the dimers and polymers were determined by nonlinear optical analysis (EFISH) as well as UV/Vis and 13C NMR spectroscopy. The chemical shifts of C7 for the polymers appeared as two peaks in the 13C NMR spectra when the substituents are electron-withdrawing groups. The percentage decrease in the relative extinction coefficient of the polymers, epsilon(d), was linearly related to the Hammett constant sigma. Polynorbornenes with electron-withdrawing substituents may adopt isotactic stereochemistry with all pendant groups aligned in one direction. The nature of the interactions between neighboring chromophores may be one of the most important factors in directing the stereoregularity and conformation of these polymers. The corresponding polymers derived from the exo isomers appeared to be less stereoregular.


Assuntos
Hidrocarbonetos Aromáticos/química , Norbornanos/química , Dimerização , Espectroscopia de Ressonância Magnética , Polímeros , Análise Espectral , Estereoisomerismo
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