全文获取类型
收费全文 | 677篇 |
免费 | 42篇 |
专业分类
719篇 |
出版年
2024年 | 2篇 |
2023年 | 3篇 |
2022年 | 7篇 |
2021年 | 26篇 |
2020年 | 15篇 |
2019年 | 14篇 |
2018年 | 20篇 |
2017年 | 20篇 |
2016年 | 23篇 |
2015年 | 38篇 |
2014年 | 40篇 |
2013年 | 49篇 |
2012年 | 64篇 |
2011年 | 62篇 |
2010年 | 34篇 |
2009年 | 26篇 |
2008年 | 41篇 |
2007年 | 47篇 |
2006年 | 22篇 |
2005年 | 24篇 |
2004年 | 30篇 |
2003年 | 20篇 |
2002年 | 14篇 |
2001年 | 2篇 |
2000年 | 7篇 |
1999年 | 5篇 |
1998年 | 2篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 6篇 |
1991年 | 6篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1985年 | 3篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1969年 | 1篇 |
1961年 | 2篇 |
1959年 | 2篇 |
1958年 | 2篇 |
1957年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有719条查询结果,搜索用时 21 毫秒
1.
2.
Prevalence of different species of Penicillium and their concentrations per cubic meter of air were evaluated with the use of Hi-Air sampler system Mark II (Hi-Media Laboratories Ltd., India) in the air of homes (bed-rooms) at four different sites in Nagpur. At each of these sites, air sampling was done fortnightly in triplicate for 2 years duration from June 2000 to May 2002. The sampling was also done in triplicate for the outdoor air in the vicinity of each home on the same day immediately after the indoor sampling was over. The mean concentration of Penicillium colony forming units at four different sites in the indoor air was 32, 46.9, 35 and 35.4 CFU/m3, respectively, whereas in the outdoor air at these same four sites, the mean concentration was 24, 28, 25 and 25.8 CFU/m3 respectively. The Penicillium concentration in the indoor air was found to be higher in winter than in other seasons (ANOVA, p < 0.05). Concentration of Penicillium spp. in intramural environment was always higher than that in extramural environment. Statistically significant difference existed between intramural and extramural environments at all the sites, with maximum difference at a site, which is old crowded area of the city. During the 2-years investigations, 11 species of Penicillium were isolated from the indoor air while nine species were isolated from the air outside the homes. The dominant species of Penicillium in indoor as well as outdoor air were P. citrinum (33.78 and 32.81), P. oxalicum (19.70 and 22.60), and P. chrysogenum (17.64 and 14.50). The percentage of the Penicillium in the indoor air was 10.70 while it was 8.36 in outdoor air. Indoor air showed the presence of P. glaber and P. sclerotiorum, which were absent in the outdoor air. 相似文献
3.
M. Anil Kumar S. S. Sravanthi Pammi M. S. Sukanya Archana Giri 《In vitro cellular & developmental biology. Plant》2018,54(1):94-103
These studies report the development of an efficient technique for large-scale cultivation of fast-growing hairy root culture systems for production of bioactive isoflavones. Trifolium pratense L. is an important source of pharmaceutically important isoflavones with immense health care applications. Trifolium pratense was transformed using different strains of Agrobacterium rhizogenes for hairy root induction and establishment of hairy root rhizoclones. Selected fast-growing rhizoclones of T. pratense were evaluated for their growth and isoflavone production. This study is the first report of stable production of isoflavones through successive culture passages from transformed hairy-root rhizoclones of T. pratense. One of the fast-growing hairy-root rhizoclones 2364A displayed significantly higher accumulation of all four pharmaceutically important isoflavones, 8.56 mg (gdw)?1 of daidzein, 2.45 mg (gdw)?1 of genistein, 15.23 mg (gdw)?1 of formononetin, and 1.10 mg (gdw)?1 of biochanin A, compared to other rhizoclones. 相似文献
4.
Evaluation of Postharvest-Processed Oysters by Using PCR-Based Most-Probable-Number Enumeration of Vibrio vulnificus Bacteria 下载免费PDF全文
Anita C. Wright Victor Garrido Georgia Debuex Melissa Farrell-Evans Archana A. Mudbidri W. Steven Otwell 《Applied microbiology》2007,73(22):7477-7481
Postharvest processing (PHP) is used to reduce levels of Vibrio vulnificus in oysters, but process validation is labor-intensive and expensive. Therefore, quantitative PCR was evaluated as a rapid confirmation method for most-probable-number enumeration (QPCR-MPN) of V. vulnificus bacteria in PHP oysters. QPCR-MPN showed excellent correlation (R2 = 0.97) with standard MPN and increased assay sensitivity and efficiency. 相似文献
5.
Christine M. Gross Ruslan Rafikov Sanjiv Kumar Saurabh Aggarwal P. Benson Ham III Mary Louise Meadows Mary Cherian-Shaw Archana Kangath Supriya Sridhar Rudolf Lucas Stephen M. Black 《PloS one》2015,10(3)
Lipopolysaccharide (LPS) derived from the outer membrane of gram-negative bacteria induces acute lung injury (ALI) in mice. This injury is associated with lung edema, inflammation, diffuse alveolar damage, and severe respiratory insufficiency. We have previously reported that LPS-mediated nitric oxide synthase (NOS) uncoupling, through increases in asymmetric dimethylarginine (ADMA), plays an important role in the development of ALI through the generation of reactive oxygen and nitrogen species. Therefore, the focus of this study was to determine whether mice deficient in endothelial NOS (eNOS-/-) are protected against ALI. In both wild-type and eNOS-/- mice, ALI was induced by the intratracheal instillation of LPS (2 mg/kg). After 24 hours, we found that eNOS-/-mice were protected against the LPS mediated increase in inflammatory cell infiltration, inflammatory cytokine production, and lung injury. In addition, LPS exposed eNOS-/- mice had increased oxygen saturation and improved lung mechanics. The protection in eNOS-/- mice was associated with an attenuated production of NO, NOS derived superoxide, and peroxynitrite. Furthermore, we found that eNOS-/- mice had less RhoA activation that correlated with a reduction in RhoA nitration at Tyr34. Finally, we found that the reduction in NOS uncoupling in eNOS-/- mice was due to a preservation of dimethylarginine dimethylaminohydrolase (DDAH) activity that prevented the LPS-mediated increase in ADMA. Together our data suggest that eNOS derived reactive species play an important role in the development of LPS-mediated lung injury. 相似文献
6.
Archana Sachdev Monica Sharma R. P. Johari S. L. Mehta 《Journal of plant biochemistry and biotechnology.》1995,4(1):33-36
The strain BYT-1, capable of utilizing ODAP/DAP as a sole source of nitrogen and carbon was identified as Psuedomonas stutzeri by various microbial and biochemical tests. Transformation experiments showed that the ODAP utilizing property Is encoded by the plasmid. Restriction of plasmid DNA with Pstl, followed by cloning of fragments and screening of ODAP containing medium, led to the isolation of a clone with insert size of ?3.3 kb, which encoded ODAP metabolizing property. The growth and ODAP/DAP utilization by this clone (TB) was almost similar to that of the wild type strain. 相似文献
7.
Archana Aggarwal Man Mohan Misro Ankur Maheshwari Neeta Sehgal Deoki Nandan 《Molecular reproduction and development》2010,77(10):900-909
We have earlier reported that following persistent stimulation with hCG, oxidative stress‐induced apoptosis in rat Leydig cells was mainly achieved through the extrinsic pathway. In the present study, the role of N‐acetylcysteine (NAC) in counteracting the oxidative stress and the mechanisms of inhibition of apoptosis under such conditions were investigated. NAC (1 mM) intervention with repeated hCG stimulation (50 ng/ml, four times, each with 30 min challenge) prevented the decline in Leydig cell viability and the rise in lipid peroxidation and reactive oxygen species. Simultaneously, the activities of the enzymes glutathione‐S‐transferase, catalase, superoxide dismutase and the intracellular glutathione and antioxidant capacity of the treated cells improved significantly. Apoptotic markers Fas, FasL, and caspase‐8, up‐regulated following repeated hCG exposure, were significantly down‐regulated following NAC co‐incubation. While Bcl‐2 expression was fully restored, Bax and caspase‐9 remained unchanged. NAC treatment induced down‐regulation of upstream JNK/pJNK and down‐stream caspase‐3 in the target cells. Taken together, the above findings indicate that NAC counteracted the oxidative stress in Leydig cells induced as a result of repeated hCG stimulation, and inhibited apoptosis by mainly regulating the extrinsic and JNK pathways of metazoan apoptosis. Mol. Reprod. Dev. 77:900–909, 2010. © 2010 Wiley‐Liss, Inc. 相似文献
8.
Haque I Banerjee S Mehta S De A Majumder M Mayo MS Kambhampati S Campbell DR Banerjee SK 《The Journal of biological chemistry》2011,286(50):43475-43485
9.
Prasad Archana Patel Preeti Pandey Shatrujeet Niranjan Abhishek Misra Pratibha 《Protoplasma》2020,257(2):561-572
Protoplasma - Growth and production kinetics of three important glycoalkaloids viz. α-solanine, solanidine, and solasodine in two contrasting prickly and prickleless plants of Solanum viarum... 相似文献
10.
Yasmin J. Cardoza Archana Vasanthakumar Alonso Suazo & Kenneth F. Raffa 《Entomologia Experimentalis et Applicata》2009,131(2):138-147
In a recent study, we reported a previously undescribed behavior in which a bark beetle exuded oral secretions containing bacteria that have antifungal properties, and hence defend their galleries against pervasive antagonistic Hyphomycete fungi. Actinobacteria, a group known for their antibiotic properties, were the most effective against fungi that invade the spruce beetle galleries. In the present study, we describe the isolation and identification of microorganisms from oral secretions of three bark beetles (Coleoptera: Curculionidae: Scolytinae): the spruce beetle, Dendroctonus rufipennis Kirby, the mountain pine beetle, Dendroctonus ponderosae Hopkins, and the pine engraver, Ips pini Say. Bacteria isolated from these three species span the major bacterial classes α-, β-, and γ-Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria, except for D. ponderosae , which yielded no α-proteobacteria or Bacteroidetes isolates. Spruce beetles and pine engraver beetles had similar numbers of α-proteobacteria isolates, but pine engravers yielded twice as many Bacteroidetes isolates as spruce beetles. In contrast, mountain pine beetles yielded more isolates in the β- and γ-proteobacteria than spruce beetles and pine engravers. The highest percentage of Actinobacteria was obtained from spruce beetles, followed by pine engravers and mountain pine beetles. All of the fungal isolates obtained from the three beetle species were Ascomycetes. The greatest fungal diversity was obtained in spruce beetles, which had nine species, followed by pine engravers with five, and mountain pine beetles with one. 相似文献