全文获取类型
收费全文 | 307篇 |
免费 | 25篇 |
出版年
2022年 | 3篇 |
2021年 | 6篇 |
2019年 | 2篇 |
2018年 | 7篇 |
2017年 | 6篇 |
2016年 | 12篇 |
2015年 | 15篇 |
2014年 | 16篇 |
2013年 | 28篇 |
2012年 | 23篇 |
2011年 | 18篇 |
2010年 | 8篇 |
2009年 | 8篇 |
2008年 | 16篇 |
2007年 | 14篇 |
2006年 | 19篇 |
2005年 | 11篇 |
2004年 | 14篇 |
2003年 | 12篇 |
2002年 | 8篇 |
2001年 | 7篇 |
2000年 | 5篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 6篇 |
1985年 | 7篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1974年 | 2篇 |
1973年 | 5篇 |
1972年 | 1篇 |
1971年 | 3篇 |
1969年 | 1篇 |
1968年 | 2篇 |
1965年 | 1篇 |
排序方式: 共有332条查询结果,搜索用时 15 毫秒
291.
Satyanarayana Rentala Ramakrishna Chintala Manohar Guda Madhuri Chintala Aruna Lakshmi Komarraju Lakshmi Narasu Mangamoori 《Biochemical and biophysical research communications》2013
Prostate cancer has become a global health concern and is one of the leading causes of cancer death of men after lung and gastric cancers. It has been suggested that the 3-hydroxy-3-methyl-glutarylcoenzyme-CoA (HMG-CoA) reductase inhibitor atorvastatin shows anticancer activity in prostate cancer cell lines. To this end, we analyzed the influence of atorvastatin on the cell adhesion and differentiation of CD133+CD44+ cells derived from prostate cancer biopsies and peripheral blood. CD133+CD44+ cells were treated with atorvastatin (16–64 μM) for different time periods. Cell adhesion to endothelial cell monolayers and differentiation into prostate cancer cells were evaluated. α1, β1 and α2β1 integrins adhesion receptors and the downstream target of atorvastatin Rho-dependent kinase (ROCK) and focal adhesion kinase (FAK) were analyzed by Western blot. Further blocking studies with the ROCK inhibitor H1152, anti-FAK antibody and anti-integrin α1 and β1 antibodies were carried out. Atorvastatin treatment inhibited dose-dependently cell attachment to endothelium and differentiation. The inhibitory effect of atorvastatin on cell adhesion was associated with decreased expression of integrins α1 and β1 and phosphorylated MYPT1 and FAK. Furthermore, atorvastatin strongly reduced ROCK1 and FAK mediated differentiation of CD133+CD44+ cells, which was confirmed by antibody treatment. Atorvastatin modified the expression of cell adhesion molecules and differentiation markers. These beneficial effects of atorvastatin may be mediated by ROCK and FAK signaling pathway. The data presented may point to novel treatment options for prostate cancer. 相似文献
292.
293.
Veerabrahmam Alugolu Satyanarayana Rentala Aruna Lakshmi Komarraju Uma Devi Parimi 《Bioinformation》2013,9(7):334-338
Piperine, a major constituent of Piper nigrum (Black pepper), is one of the well known components in many Ayurvedic
formulations. Piperine is most studied bioenhancer because it inhibits drug metabolizing enzymes in rodents and increases plasma
concentrations of several drugs, including P-glycoprotein substrates. However, there areno evidences on piperine-iron conjugate to
inhibit human CYP450 3A4. We therefore investigated the influence of piperine-Fe conjugate to study the metabolism of iron with
CYP450 3A4. Our in silico results showed that Piperine when conjugated with iron, inhibited activity of CYP450 3A4. This
improved the binding of piperine-Fe conjugate with CYP450 3A4 and increased bioavailability. 相似文献
294.
Shanta Achanta Jyoti Jaju Ajay M. V. Kumar Sharath Burugina Nagaraja Srinivas Rao Motta Shamrao Sasidhar Kumar Bandi Ashok Kumar Srinath Satyanarayana Anthony David Harries Sreenivas Achutan Nair Puneet K. Dewan 《PloS one》2013,8(8)
Setting
Private medical practitioners in Visakhapatnam district, Andhra Pradesh, India.Objectives
To evaluate self-reported TB diagnostic and treatment practices amongst private medical practitioners against benchmark practices articulated in the International Standards of Tuberculosis Care (ISTC), and factors associated with compliance with ISTC.Design
Cross- sectional survey using semi-structured interviews.Results
Of 296 randomly selected private practitioners, 201 (68%) were assessed for compliance to ISTC diagnostic and treatment standards in TB management. Only 11 (6%) followed a combination of 6 diagnostic standards together and only 1 followed a combination of all seven treatment standards together. There were 28 (14%) private practitioners who complied with a combination of three core ISTC (cough for tuberculosis suspects, sputum smear examination and use of standardized treatment). Higher ISTC compliance was associated with caring for more than 20 TB patients annually, prior sensitization to TB control guidelines, and practice of alternate systems of medicine.Conclusion
Few private practitioners in Visakhapatnam, India reported TB diagnostic and treatment practices that met ISTC. Better engagement of the private sector is urgently required to improve TB management practices and to prevent diagnostic delay and drug resistance. 相似文献295.
Sokhan Khann Eang Tan Mao Yadav Prasad Rajendra Srinath Satyanarayana Sharath Burugina Nagaraja Ajay M. V. Kumar 《PloS one》2013,8(4)
Setting
National Tuberculosis Programme, Cambodia.Objective
In a cohort of TB patients, to ascertain the proportion of patients who fulfil the criteria for presumptive MDR-TB, assess whether they underwent investigation for MDR-TB, and the results of the culture and drug susceptibility testing (DST).Methods
A cross sectional record review of TB patients registered for treatment between July-December 2011.Results
Of 19,236 TB patients registered, 409 (2%) fulfilled the criteria of presumptive MDR-TB; of these, 187 (46%) were examined for culture. This proportion was higher among relapse, failure, return after default (RAD) and non-converters at 3 months of new smear positive TB patients (>60%) as compared to non-converters at 2 months of new TB cases (<20%). Nearly two thirds (n = 113) of the samples were culture positive; of these, three-fourth (n = 85) grew Mycobacterium tuberculosis complex (MTBc) and one-fourth (n = 28) grew non-tuberculous Mycobacteria. DST results were available for 96% of the MTBc isolates. Overall, 21 patients were diagnosed as MDR-TB (all diagnosed among retreatment TB cases and none from non-converters) and all of them were initiated on MDR-TB treatment.Conclusion
There is a need to strengthen mechanisms for linking patients with presumptive MDR-TB to culture centers. The policy of testing non-converters for culture and DST needs to be reviewed. 相似文献296.
Yeast phytases: present scenario and future perspectives 总被引:1,自引:0,他引:1
Phytases hydrolyze phytates to liberate soluble and thus readily utilizable inorganic phosphate. Although phytases are produced by various groups of microbes, yeasts being simple eukaryotes and mostly non-pathogenic with proven probiotic benefits can serve as ideal candidates for phytase research. The full potential of yeast phytases has not, however, been exploited. This review focuses attention on the present status of knowledge on the production, characterization, molecular characteristics, and cloning and over-expression of yeast phytases. Several potential applications of the yeast phytases in feeds and foods, and in the synthesis of lower myo-inositol phosphates are also discussed. 相似文献
297.
Henrik Salje Jason R. Andrews Sarang Deo Srinath Satyanarayana Amanda Y. Sun Madhukar Pai David W. Dowdy 《PLoS medicine》2014,11(7)
Background
India has announced a goal of universal access to quality tuberculosis (TB) diagnosis and treatment. A number of novel diagnostics could help meet this important goal. The rollout of one such diagnostic, Xpert MTB/RIF (Xpert) is being considered, but if Xpert is used mainly for people with HIV or high risk of multidrug-resistant TB (MDR-TB) in the public sector, population-level impact may be limited.Methods and Findings
We developed a model of TB transmission, care-seeking behavior, and diagnostic/treatment practices in India and explored the impact of six different rollout strategies. Providing Xpert to 40% of public-sector patients with HIV or prior TB treatment (similar to current national strategy) reduced TB incidence by 0.2% (95% uncertainty range [UR]: −1.4%, 1.7%) and MDR-TB incidence by 2.4% (95% UR: −5.2%, 9.1%) relative to existing practice but required 2,500 additional MDR-TB treatments and 60 four-module GeneXpert systems at maximum capacity. Further including 20% of unselected symptomatic individuals in the public sector required 700 systems and reduced incidence by 2.1% (95% UR: 0.5%, 3.9%); a similar approach involving qualified private providers (providers who have received at least some training in allopathic or non-allopathic medicine) reduced incidence by 6.0% (95% UR: 3.9%, 7.9%) with similar resource outlay, but only if high treatment success was assured. Engaging 20% of all private-sector providers (qualified and informal [providers with no formal medical training]) had the greatest impact (14.1% reduction, 95% UR: 10.6%, 16.9%), but required >2,200 systems and reliable treatment referral. Improving referrals from informal providers for smear-based diagnosis in the public sector (without Xpert rollout) had substantially greater impact (6.3% reduction) than Xpert scale-up within the public sector. These findings are subject to substantial uncertainty regarding private-sector treatment patterns, patient care-seeking behavior, symptoms, and infectiousness over time; these uncertainties should be addressed by future research.Conclusions
The impact of new diagnostics for TB control in India depends on implementation within the complex, fragmented health-care system. Transformative strategies will require private/informal-sector engagement, adequate referral systems, improved treatment quality, and substantial resources. Please see later in the article for the Editors'' Summary 相似文献298.
A high titre of thermo-alkali-stable xylanase was attained in cane molasses medium. When the culture variables for endoxylanase production were optimized [cane molasses 7 %, soluble alkaline extract of wheat bran (SAE-WB) 37 % and ammonium chloride 0.30 %], a 4.5-fold enhancement in xylanase production (69 U ml?1) was achieved as compared to that in the unoptimized medium (15 U ml?1). The enzyme titre attained in shake flasks could be sustained in a 7-l laboratory bioreactor. An activity band corresponding to 40 kDa was visualized on SDS-PAGE zymogram analysis. The enzyme has broad range of pH and temperature for activity with optima at 9.0 and 80 °C, and stable between pH 4.0 and 11.0 with 85 % retention of activity. It has T 1/2 of 40 and 15 min at 70 and 80 °C. The enzyme is halotolerant since it displays activity in the presence of salt up to 15 %, and remains 100 % active in the absence of salt. The supplementation of whole wheat dough with xylanase improves antistaling property, reducing sugar content, bread volume with prebiotic xylooligosaccharides in bread. This is the first report on xylanase production in cane molasses medium with SAE-WB as the inducer and its applicability in whole wheat bread making that improves human health. 相似文献
299.
300.
The gene (1,542 bp) encoding thermostable Ca2+-independent and raw starch hydrolyzing α-amylase of the extremely thermophilic bacterium Geobacillus thermoleovorans encodes for a protein of 50 kDa (Gt-amyII) with 488 amino acids. The enzyme is optimally active at pH 7.0 and 60 °C with a t 1/2 of 19.4 h at 60 and 4 h at 70 °C. Gt-amyII hydrolyses corn and tapioca raw starches efficiently and therefore finds application in starch saccharification at industrial sub-gelatinisation temperatures. The starch hydrolysis is facilitated following adsorption of the enzyme to starch at the C-terminal domain, as confirmed by the truncation analysis. The adsorption rate constant of Gt-amyII to raw corn starch is 37.6-fold greater than that for the C-terminus truncated enzyme (Gt-amyII-T). Langmuir–Hinshelwood kinetic analysis in terms of equilibrium parameter (K R) suggested that the adsorption of Gt-amyII to corn starch is more favourable than that of Gt-amyII-T. Thermodynamics of temperature inactivation indicated a decrease in thermostabilisation of Gt-amyII upon truncation of its C-terminus. The addition of raw corn starch increased t 1/2 of Gt-amyII, but it has no such effect on Gt-amyII-T. It can, therefore, be stated that Gt-amyII binds to raw corn starch via C-terminal region that contributes to its thermostability. Phylogenetic analysis confirmed that starch binding region of Gt-amyII is, in fact, the non-catalytic domain C, and not the typical SBD of CBM families. The role of domain C in raw starch binding throws light on the evolutionary path of the known SBDs. 相似文献