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31.
Streptococcus mutans contributes significantly to dental caries, which arises from homoeostasic imbalance between host and microbiota. We hypothesized that Lactobacillus sp. inhibits growth, biofilm formation and gene expression of Streptococcus mutans. Antibacterial (agar diffusion method) and antibiofilm (crystal violet assay) characteristics of probiotic Lactobacillus sp. against Streptococcus mutans (ATCC 25175) were evaluated. We investigated whether Lactobacillus casei (ATCC 393), Lactobacillus reuteri (ATCC 23272), Lactobacillus plantarum (ATCC 14917) or Lactobacillus salivarius (ATCC 11741) inhibit expression of Streptococcus mutans genes involved in biofilm formation, quorum sensing or stress survival using quantitative real‐time polymerase chain reaction (qPCR). Growth changes (OD600) in the presence of pH‐neutralized, catalase‐treated or trypsin‐treated Lactobacillus sp. supernatants were assessed to identify roles of organic acids, peroxides and bacteriocin. Susceptibility testing indicated antibacterial (pH‐dependent) and antibiofilm activities of Lactobacillus sp. against Streptococcus mutans. Scanning electron microscopy revealed reduction in microcolony formation and exopolysaccharide structural changes. Of the oral normal flora, L. salivarius exhibited the highest antibiofilm and peroxide‐dependent antimicrobial activities. All biofilm‐forming cells treated with Lactobacillus sp. supernatants showed reduced expression of genes involved in exopolysaccharide production, acid tolerance and quorum sensing. Thus, Lactobacillus sp. can inhibit tooth decay by limiting growth and virulence properties of Streptococcus mutans.  相似文献   
32.
An active strain of Aspergillus spp. has been selected for the production of cellulolytic enzymes and proteins when grown on peracetic acid-treated wheat straw. This strain produced a considerable amount of cellulase [see 1,4-(1,3;1,4)-β-d-glucan 4-glucanohydrolase, EC 3.2.1.4] in the extracellular supernatant and exhibited good overall cellulolytic activity, as measured using filter paper and Avicel as substrates. Also, under the same conditions the strain showed high activities of β-d-glucosidase (β-d-glucoside glucohydrolase, EC 3.2.1.21) and β-d-xylosidase (1,4-β-d-xylan xylohydrolase, EC 3.2.1.37). The maximum enzyme yields (carboxymethylcellulose activity 26.4 units ml?1, filter paper activity 2.26 units ml?1 and Avicel activity 16.82 units ml?1; β-d-glucosidase 9.09 units ml?1 and β-d-xylosidase 1.92 units ml?1) were obtained after 96 h incubation at 45°C.  相似文献   
33.
Hypersensitivity pneumonitis (HP) is an interstitial lung disease that develops following repeated exposure to environmental antigens. The disease results in alveolitis, granuloma formation and may progress to a fibrotic chronic form, which is associated with significant morbidity and mortality. The severity of the disease correlates with a neutrophil rich influx and an IL-17 response. We used the Saccharopolyspora rectivirgula (SR) model of HP to determine whether Toll-like receptors (TLR) 2 and 9 cooperate in neutrophil recruitment and IL-17-associated cytokine production during the development of HP. Stimulation of bone marrow derived macrophages (BMDMs) from C57BL/6, MyD88-/- and TLR2/9-/- mice with SR demonstrate that SR is a strong inducer of neutrophil chemokines and growth factors. The cytokines induced by SR were MyD88-dependent and, of those, most were partially or completely dependent on TLRs 2 and 9. Following in vivo exposure to SR, CXCL2 production and neutrophil recruitment were reduced in TLR2-/- and TLR2/9-/- mice suggesting that the response was largely dependent on TLR2; however the reduction was greatest in the TLR2/9-/- double knockout mice indicating TLR9 may also contribute to the response. There was a reduction in the levels of pro-inflammatory cytokines TNFα and IL-6 as well as CCL3 and CCL4 in the BALF from TLR2/9-/- mice compared to WT and single knockout (SKO) mice exposed one time to SR. The decrease in neutrophil recruitment and TNFα production in the TLR2/9-/- mice was maintained throughout 3 weeks of SR exposures in comparison to WT and SKO mice. Both TLRs 2 and 9 contributed to the Th17 response; there was a decrease in Th17 cells and IL-17 mRNA in the TLR2/9-/- mice in comparison to the WT and SKO mice. Despite the effects on neutrophil recruitment and the IL-17 response, TLR2/9-/- mice developed granuloma formation similarly to WT and SKO mice suggesting that there are additional mediators and pattern recognition receptors involved in the disease.  相似文献   
34.
Six hundred and forty Nile tilapia (Oreochromis niloticus) weighing 80–100 g were randomly allocated into eight equal groups (80 each). The first group acts as control. Groups S, B and L were fed on a ration supplemented with Saccharomyces cerevisiae, β-glucans and laminaran, respectively for 21 days. Groups M, MS, MB and ML were subjected throughout the experiment to sublethal concentration of mercuric chloride (0.05 ppm). Gps. MS, MB and ML were fed on a ration containing S. cerevisiae, β-glucan and laminaran respectively for 21 days. Fish were challenged with Aeromonas hydrophila (0.4 × 107 cells mL?1) via intra-peritoneal injection and the mortality rate was recorded up to 10 day post-challenge. The non-specific defense mechanisms, cellular and humoral immunity, beside the total and differential leukocytic count were determined.Lymphocyte transformation index, phagocytic activity percent, phagocytic index, total lymphocyte count, serum bactericidal activity and nitric oxide as well as the survival rate were insignificantly changed after 21 day in gps. MS&ML, when compared with mercuric chloride immune depressed group M. These parameters as well as the neutrophil adhesion, serum nitric oxide and survival rate were significantly increased in gp. MB when compared with gp. M. Meanwhile the cellular and humoral immunity beside the survival rate were significantly increased in groups S, B, L when compared with control group.It could be concluded that the whole yeast S. cerevisiae, β-glucan and laminaran can be used as immunostimulants for the farmed Nile tilapia. The β-glucans could be used in farmed Nile tilapia, under immune depressive stressful condition to increase their resistance to diseases.  相似文献   
35.
Recent literature lacks studies on the effects of progesterone withdrawal on peripheral conversion of thyroxin (T4) into triiodothyronine (T3) by iodothyronine deiodinase 2 (D2) in different body tissues. The present study aimed to assess the possible relation of progesterone to T4, T3, and D2 in ovarectomized rats. Thirty female Wistar rats were included into a sham-operated control group and an ovarectomized group. Four months following the surgical procedures, measurements of estradiol, progesterone, free T4, free T3, and thyroid-stimulating hormone (TSH) were done. Also, estradiol/progesterone and T4/T3 ratios were calculated. Tissue homogenates from the kidney, liver, brain, thyroid, mandible, and femur were used to assess expression of D2 mRNA. The estradiol/progesterone ratio showed a significant increase in ovarectomized rats. T4 showed a significant increase in contrast to T3 which showed a highly significant decrease following ovariectomy. The T4/T3 ratio was significantly increased in ovarectomized rats. In addition, D2 expression was significantly attenuated in all tissue homogenates of the ovarectomized group. The present work showed a significant positive correlation between T4 and T3 in the sham-operated control rats, which was abolished in ovarectomized rats. A negative significant correlation between progesterone and T4 was revealed in ovarectomized rats. There was also a significant positive correlation between progesterone and D2 expression in the ovarectomized group. The results of the present study hypothesize that progesterone withdrawal may underlie the decrement in D2 expression, with consequent reduction in the peripheral conversion of T4 into T3 leading to a hypothyroid state.  相似文献   
36.
Malaria caused by genus Plasmodium, is a parasite which is the main health issue for humans and about half of the population were suffered. An every year, approximately 1.2–2.7 million people died due to malaria globally. Therefore to prevent the spreading of malaria from the glob novel active drugs with specific activities are necessary. The present study aimed to identify novel drug molecule together with the bioinformatic tools for the development of active malarial drugs. As the search for latest anti malarial compound was developed, this work determined six active blends from various drug databases which possess drug-like characteristics and presents a significant anti malarial actions in in-silico level. Compound ID 300238, 889, 76569, 87324, 45678, and Z185397112are a few of the ligands were got from the Toss lab, Maybridge, Cambridge, Life chem, Bitter, and Examine drug databases and docked against hexokinase 1 protein (PDB: 1CZA) with high throughput practical screening (HTVS) using Glide v6.6. Amid the 6 compounds, compound no: 300238 from Toss lab has the greatest docking score of −9.889 kcal/mol targeting 1CZA protein. The active sites of Hexokinase I of protein were determine by using superimposition of the destination and template structure showed similar structural folds and active sites which were decidedly conserved. The quality of hexokinase I protein was considered to be sterically stable where the protein was prepared by utilizing the software protein preparation execute in the Schrodinger suite. Prepared proteins were evaluated using SAVES and the studies of molecular dynamics of the hexokinase, and the GROMACS were performed for protein–ligand complex. The low HOMO-LUMO energy gaps of the compound verified the greater stability of the molecule. Here, the tested drug candidates have good absorption, distribution, metabolism, and excretion (ADME) properties which were established by using QikProp, version 3.4 of Schrodinger.  相似文献   
37.
Liver fibrosis occurs due to liver injuries and toxins. Silymarin (SMR) extracted by the milk thistle seeds, is widely used such as herbal drug for its hepatoprotective properties. The purpose of this study to assess the properties of an optimized dose of encapsulated crude SMR on antidiabetic activity and liver fibrosis induced by paracetamol in male albino rat. Hepatic fibrosis was assessed by measuring liver enzymes. Results revealed that the consumption of encapsulated SMR, can effectively affluence the target and avoid the degradation of bioactive compound. Body weight of animal also significantly increased in each group during all the period. According to our optimized study, the long-term induction of SMR (300 mg/kg) significantly amplified survival time of rats with paracetamol induced hepatic injuries. The changes of liver fibrosis and the significant increase of hepatic enzyme biomarkers were also observed. In conclusion, the results suggest that SMR acts as a hepatoprotective agent by inhibiting the fibrogenisis and apoptosis in liver, as well as insulin resistance.  相似文献   
38.
The burning of incense is an important source of indoor air pollution in Asia. We assessed the effect of long‐term exposure to incense smoke on the body weight and levels of circulating glucose, triglycerides, total cholesterol, HDL‐cholesterol, insulin, adiponectin and leptin in Wistar albino rats. Two groups of rats were used. First group (n = 12) was exposed daily to incense smoke for 4 months at the rate of 4 g day?1 in the exposure chamber. Another group of rats (n = 12), was used as non‐exposed control. Blood samples were collected from all animals after 4, 8, 12 and 16 weeks of exposure. Serum glucose, triglycerides, total cholesterol and HDL‐cholesterol, LDL‐cholesterol insulin, adiponectin and leptin were measured. Our results showed that incense smoke exposure was associated with decreased weight gain and the adverse metabolic changes of increased triglycerides and decreased HDL‐cholesterol concentrations. Exposure to incense was also associated with a transient increase of leptin levels. Taken together, these data suggest that incense smoke influences metabolism adversely in rats. The effect of incense smoke on human health and the underlying mechanisms need to be studied further. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   
39.
Low dose methotrexate is the cornerstone for the treatment of rheumatoid arthritis. One of its major drawbacks is hepatotoxicity, resulting in poor compliance of therapy. Dissatisfied arthritis patients are likely to seek the option of complementary and alternative medicine such as bee venom. The combination of natural products with modern medicine poses the possibility of potential interaction between the two groups and needs investigation. The present study was aimed to investigate the modulatory effect of bee venom acupuncture on efficacy, toxicity, and pharmacokinetics and tissue disposition of methotrexate. Complete Freund''s adjuvant induced arthritic rats were treated for 3 weeks with methotrexate and/or bee venom. Arthritic score, ankle diameter, paw volume and tissue expression of NF-κB and TNF-α were determined to assess anti-arthritic effects, while anti-nociceptive effects were assessed by gait score and thermal hyperalgesia. Methotrexate toxicity was assessed by measuring serum TNF-α, liver enzymes and expression of NF-κB in liver. Combination therapy of bee venom with methotrexate significantly improved arthritic parameters and analgesic effect as compared to methotrexate alone. Bee venom ameliorated serum TNF-α and liver enzymes elevations as well as over expression of NF-κB in liver induced by methotrexate. Histological examination supported the results. And for the first time bee venom acupuncture was approved to increase methotrexate bioavailability with a significant decrease in its elimination. Conclusion: bee venom potentiates the anti-arthritic effects of methotrexate, possibly by increasing its bioavailability. Also, it provides a potent anti-nociceptive effect. Furthermore, bee venom protects against methotrexate induced hepatotoxicity mostly due to its inhibitory effect on TNF-α and NF-κB.  相似文献   
40.
To explore the mechanisms underlying the suggested role of the vitamin D/vitamin D receptor (VDR) complex in the pathogenesis of obesity we performed genetic and immunologic analyses in obese and non-obese Saudi individuals without other concomitant chronic diseases. Genomic DNA was genotyped for gene single nucleotide polymorphisms (SNPs) of VDR by allelic discrimination in 402 obese (body mass index –BMI≥30 kg/m2) and 489 non-obese (BMI<30 kg/m2) Saudis. Q-PCR analyses were performed using an ABI Prism 7000 Sequence Detection System. The inflammosome pathway was analysed by PCR, cytokines and plasma lipopolysaccaride (LPS) concentrations with ELISA assays. Results showed that the VDR SNPs rs731236 (G) (TaqI) and rs1544410 (T) (Bsm-I) minor allele polymorphisms are significantly more frequent in obese individuals (p = 0.009, β = 0.086 and p = 0.028, β = 0.072, respectively). VDR haplotypes identified are positively (GTA) (p = 0.008, β = 1.560); or negatively (ACC) (p = 0.044, β = 0.766) associated with obesity and higher BMI scores. The GTA "risk" haplotype was characterized by an up-regulation of inflammosome components, a higher production of proinflammatory cytokines (p<0.05) and a lower VDR expression. Plasma LPS concentration was also increased in GTA obese individuals (p<0.05), suggesting an alteration of gut permeability leading to microbial translocation. Data herein indicate that polymorphisms affecting the vitamin D/VDR axis play a role in obesity that is associated with an ongoing degree of inflammation, possibly resulting from alterations of gut permeability and microbial translocation. These results could help the definition of VDR fingerprints that predict an increased risk of developing obesity and might contribute to the identification of novel therapeutic strategies for this metabolic condition.  相似文献   
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