全文获取类型
收费全文 | 166篇 |
免费 | 4篇 |
出版年
2023年 | 2篇 |
2022年 | 9篇 |
2021年 | 6篇 |
2020年 | 14篇 |
2019年 | 5篇 |
2018年 | 4篇 |
2017年 | 3篇 |
2016年 | 9篇 |
2015年 | 10篇 |
2014年 | 12篇 |
2013年 | 16篇 |
2012年 | 16篇 |
2011年 | 8篇 |
2010年 | 7篇 |
2009年 | 8篇 |
2008年 | 5篇 |
2007年 | 5篇 |
2006年 | 2篇 |
2005年 | 5篇 |
2004年 | 3篇 |
2003年 | 1篇 |
2002年 | 1篇 |
1998年 | 1篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1987年 | 3篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有170条查询结果,搜索用时 15 毫秒
71.
Khurshid A. Bhat Bhahwal A. Shah Kuldeep K. Gupta Anjali Pandey Sarang Bani Subhash C. Taneja 《Bioorganic & medicinal chemistry letters》2009,19(7):1939-1943
Semi-synthetic analogs of pinitol were subjected to screening by determining TNF-α expression in human neutrophils using flowcytometry. Among the tested compounds, three derivatives displayed more than 50% inhibition of TNF-α cytokine secretion in LPS induced stimulated neutrophils and can be considered as potent anti-inflammatory moieties. 相似文献
72.
Xanthan-g-poly(acrylamide) was synthesized employing microwave-assisted and ceric-induced graft copolymerization, and was characterized by FT-IR, DSC, XRD and SEM studies. Matrix tablets of diclofenac sodium were formulated using graft copolymer as the matrix by direct compression technique. Release behavior of the graft copolymer was evaluated using USP type-II dissolution apparatus in 900 ml of phosphate buffer (pH 6.8), maintained at 37 °C and at 50 rpm. Microwave-assisted grafting provided graft copolymer with higher % grafting in a shorter time in comparison to the ceric-induced grafting. The % grafting was found to increase with the increase in the power of microwave and/or time of exposure. The matrix tablets were found to release the drug by zero-order kinetics, and the faster release of drug was observed from the graft copolymer matrix as compared to the xanthan gum matrix. It was observed that grafting reduces the swelling, but increases the erosion of xanthan gum. 相似文献
73.
Anuradha Singh Pradeep K. Singh Rakesh Singh Awadhesh Pandit Ajay K. Mahato Deepak K. Gupta Kuldeep Tyagi Ashok K. Singh Nagendra K. Singh Tilak R. Sharma 《Molecular breeding : new strategies in plant improvement》2010,26(2):325-338
Betaine aldehyde dehydrogenase (BADH) is a key enzyme involved in the synthesis of glycinebetaine—a powerful osmoprotectant
against salt and drought stress in a large number of species. Rice is not known to accumulate glycinebetaine but it has two
functional genes coding for the BADH enzyme. A non-functional allele of the BADH2 gene located on chromosome 8 is a major factor associated with rice aroma. However, similar information is not available
regarding the BADH1 gene located on chromosome 4 despite the similar biochemical function of the two genes. Here we report on the discovery and
validation of SNPs in the BADH1 gene by re-sequencing of diverse rice varieties differing in aroma and salt tolerance. There were 17 SNPs in introns with
an average density of one per 171 bp, but only three SNPs in exons at a density of one per 505 bp. Each of the three exonic
SNPs led to changes in amino acids with functional significance. Multiplex SNP assays were used for genotyping of 127 diverse
rice varieties and landraces. In total 15 SNP haplotypes were identified but only four of these, corresponding to two protein
haplotypes, were common, representing more than 85% of the cultivars. Determination of population structure using 54 random
SNPs classified the varieties into two groups broadly corresponding to indica and japonica cultivar groups, aromatic varieties clustering with the japonica group. There was no association between salt tolerance and the common BADH1 haplotypes, but aromatic varieties showed specific
association with a BADH1 protein haplotype (PH2) having lysine144 to asparagine144 and lysine345 to glutamine345 substitutions. Protein modeling and ligand docking studies show that these two substitutions lead to reduction in the substrate
binding capacity of the BADH1 enzyme towards gamma-aminobutyraldehyde (GABald), which is a precursor of the major aroma compound
2-acetyl-1-pyrroline (2-AP). This association requires further validation in segregating populations for potential utilization
in the rice breeding programs. 相似文献
74.
Rotaviruses (RV) are a major cause of gastroenteritis in children. Widespread vitamin A deficiency is associated with reduced efficacy of vaccines and higher incidence of diarrheal infections in children in developing countries. We established a vitamin A deficient (VAD) gnotobiotic piglet model that mimics subclinical vitamin A deficiency in children to study its effects on an oral human rotavirus (HRV) vaccine and virulent HRV challenge. Piglets derived from VAD and vitamin A sufficient (VAS) sows were orally vaccinated with attenuated HRV or mock, with/without supplemental vitamin A and challenged with virulent HRV. Unvaccinated VAD control piglets had significantly lower hepatic vitamin A, higher severity and duration of diarrhea and HRV fecal shedding post-challenge as compared to VAS control pigs. Reduced protection coincided with significantly higher innate (IFNα) cytokine and CD8 T cell frequencies in the blood and intestinal tissues, higher pro-inflammatory (IL12) and 2-3 fold lower anti-inflammatory (IL10) cytokines, in VAD compared to VAS control pigs. Vaccinated VAD pigs had higher diarrhea severity scores compared to vaccinated VAS pigs, which coincided with lower serum IgA HRV antibody titers and significantly lower intestinal IgA antibody secreting cells post-challenge in the former groups suggesting lower anamnestic responses. A trend for higher serum HRV IgG antibodies was observed in VAD vs VAS vaccinated groups post-challenge. The vaccinated VAD (non-vitamin A supplemented) pigs had significantly higher serum IL12 (PID2) and IFNγ (PID6) compared to vaccinated VAS groups suggesting higher Th1 responses in VAD conditions. Furthermore, regulatory T-cell responses were compromised in VAD pigs. Supplemental vitamin A in VAD pigs did not fully restore the dysregulated immune responses to AttHRV vaccine or moderate virulent HRV diarrhea. Our findings suggest that that VAD in children in developing countries may partially contribute to more severe rotavirus infection and lower HRV vaccine efficacy. 相似文献
75.
76.
Neelam Verma Kuldeep Kumar Gurnoor Kaur Sneh Anand 《Critical reviews in biotechnology》2013,33(1):45-62
ABSTRACTThis article comprises detailed information about L-asparaginase, encompassing topics such as microbial and plant sources of L-asparaginase, treatment with L-asparaginase, mechanism of action of L-asparaginase, production, purification, properties, expression and characteristics of l-asparaginase along with information about studies on the structure of L-asparaginase. Although L-asparaginase has been reviewed by , our effort has been to include recent and updated information about the enzyme covering new aspects such as structural modification and immobilization of L-asparaginase, recombinant L-asparaginase, resistance to L-asparaginase, methods of assay of L-asparagine and L-asparaginase activity using the biosensor approach, L-asparaginase activity in soil and the factors affecting it. Also, side-effects of L-asparaginase treatment in acute lymphoblastic leukemia (ALL) have been discussed in the current review. L-asparaginase has been and is still one of the most widely studied therapeutic enzymes by researchers and scientists worldwide. 相似文献
77.
Alarming Levels of Drug-Resistant Tuberculosis in HIV-Infected Patients in Metropolitan Mumbai,India
Petros Isaakidis Mrinalini Das Ajay M V Kumar Christopher Peskett Minni Khetarpal Arun Bamne Balkrishna Adsul Mamta Manglani Kuldeep Singh Sachdeva Malik Parmar Avinash Kanchar B.B. Rewari Alaka Deshpande Camilla Rodrigues Anjali Shetty Lorraine Rebello Peter Saranchuk 《PloS one》2014,9(10)
Background
Drug-resistant tuberculosis (DR-TB) is a looming threat to tuberculosis control in India. However, no countrywide prevalence data are available. The burden of DR-TB in HIV-co-infected patients is likewise unknown. Undiagnosed and untreated DR-TB among HIV-infected patients is a major cause of mortality and morbidity. We aimed to assess the prevalence of DR-TB (defined as resistance to any anti-TB drug) in patients attending public antiretroviral treatment (ART) centers in greater metropolitan Mumbai, India.Methods
A cross-sectional survey was conducted among adults and children ART-center attendees. Smear microscopy, culture and drug-susceptibility-testing (DST) against all first and second-line TB-drugs using phenotypic liquid culture (MGIT) were conducted on all presumptive tuberculosis patients. Analyses were performed to determine DR-TB prevalence and resistance patterns separately for new and previously treated, culture-positive TB-cases.Results
Between March 2013 and January 2014, ART-center attendees were screened during 14135 visits, of whom 1724 had presumptive TB. Of 1724 attendees, 72 (4%) were smear-positive and 202 (12%) had a positive culture for Mycobacterium tuberculosis. Overall DR-TB was diagnosed in 68 (34%, 95% CI: 27%–40%) TB-patients. The proportions of DR-TB were 25% (29/114) and 44% (39/88) among new and previously treated cases respectively. The patterns of DR-TB were: 21% mono-resistant, 12% poly-resistant, 38% multidrug-resistant (MDR-TB), 21% pre-extensively-drug-resistant (MDR-TB plus resistance to either a fluoroquinolone or second-line injectable), 6% extensively drug-resistant (XDR-TB) and 2% extremely drug-resistant TB (XDR-TB plus resistance to any group-IV/V drug). Only previous history of TB was significantly associated with the diagnosis of DR-TB in multivariate models.Conclusion
The burden of DR-TB among HIV-infected patients attending public ART-centers in Mumbai was alarmingly high, likely representing ongoing transmission in the community and health facilities. These data highlight the need to promptly diagnose drug-resistance among all HIV-infected patients by systematically offering access to first and second-line DST to all patients with ‘presumptive TB’ rather than ‘presumptive DR-TB’ and tailor the treatment regimen based on the resistance patterns. 相似文献78.
Neeta Singla Srinath Satyanarayana Kuldeep Singh Sachdeva Rafael Van den Bergh Tony Reid Katherine Tayler-Smith V. P. Myneedu Engy Ali Donald A. Enarson Digamber Behera Rohit Sarin 《PloS one》2014,9(7)
Setting
National Institute of Tuberculosis and Respiratory Diseases (erstwhile Lala Ram Sarup Institute) in Delhi, India.Objectives
To evaluate before and after the introduction of the line Probe Assay (LPA) a) the overall time to MDR-TB diagnosis and treatment initiation; b) the step-by-step time lapse at each stage of patient management; and c) the lost to follow-up rates.Methods
A retrospective cohort analysis was done using data on MDR-TB patients diagnosed during 2009–2012 under Revised National Tuberculosis Control Programme at the institute.Results
Following the introduction of the LPA in 2011, the overall median time from identification of patients suspected for MDR-TB to the initiation of treatment was reduced from 157 days (IQR 127–200) to 38 days (IQR 30–79). This reduction was attributed mainly to a lower diagnosis time at the laboratory. Lost to follow-up rates were also significantly reduced after introduction of the LPA (12% versus 39% pre-PLA).Conclusion
Introduction of the LPA was associated with a major reduction in the delay between identification of patients suspected for MDR-TB and initiation of treatment, attributed mainly to a reduction in diagnostic time in the laboratory. 相似文献79.
Upadhyay SK Saurabh S Singh R Rai P Dubey NK Chandrashekar K Negi KS Tuli R Singh PK 《The protein journal》2011,30(6):374-383
A lectin was purified from the leaves of Allium altaicum and corresponding gene was cloned. The lectin namely Allium altaicum agglutinin (AAA) was ~24 kDa homodimeric protein and similar to a typical garlic leaf lectin. It was synthesized as 177 amino
acid residues pre-proprotein, which consisted of 28 and 43 amino acid long N and C-terminal signal peptides, respectively.
The plant expressed this protein more in scapes and flowers in comparison to the bulbs and leaves. Hemagglutination activity
(with rabbit erythrocytes) was 1,428 fold higher as compared to Allium sativum leaf agglutinin (ASAL) although, the insecticidal activity against cotton aphid (Aphis gossypii) was relatively low. Glycan array revealed that AAA had higher affinity towards GlcAb1-3Galb as compared to ASAL. Homology
analysis showed 57–94% similarity with other Allium lectins. The mature protein was expressed in E. coli as a fusion with SUMO peptide in soluble and biologically active form. Recombinant protein retained high hemagglutination activity. 相似文献
80.
Ashoktaru Barat S. P. Bravo Suresh Chandra A. S. Corrêa M. I. Giombini R. N. C. Guedes Ma Huailei Kuldeep K. Lal Lu Liang Rakesh Matura Vindhya Mohindra L. O. Oliveira Ruchi Patangia Liu Qiyong Rama Shankar Sah Akanksha Singh Birender Kumar Singh Rajeev K. Singh D. S. Tosto Ratnesh K. Tripathi C. C. Vinson 《Molecular ecology resources》2012,12(6):1196-1197
This article documents the addition of 96 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Clarias batrachus, Marmota himalayana, Schizothorax richardsonii, Sitophilus zeamais and Syagrus romanzoffiana. These loci were cross‐tested on the following species: Clarias dussumeri, Clarias gariepinus, Heteropneustus fossilis, Sitophilus granarius and Sitophilus oryzae. 相似文献