全文获取类型
收费全文 | 719篇 |
免费 | 52篇 |
出版年
2023年 | 3篇 |
2022年 | 15篇 |
2021年 | 20篇 |
2020年 | 8篇 |
2019年 | 12篇 |
2018年 | 20篇 |
2017年 | 23篇 |
2016年 | 15篇 |
2015年 | 36篇 |
2014年 | 34篇 |
2013年 | 53篇 |
2012年 | 55篇 |
2011年 | 47篇 |
2010年 | 28篇 |
2009年 | 24篇 |
2008年 | 28篇 |
2007年 | 36篇 |
2006年 | 29篇 |
2005年 | 29篇 |
2004年 | 31篇 |
2003年 | 24篇 |
2002年 | 14篇 |
2001年 | 20篇 |
2000年 | 19篇 |
1999年 | 15篇 |
1998年 | 9篇 |
1996年 | 6篇 |
1993年 | 3篇 |
1992年 | 10篇 |
1991年 | 8篇 |
1990年 | 8篇 |
1989年 | 9篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1986年 | 7篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 3篇 |
1980年 | 5篇 |
1979年 | 2篇 |
1978年 | 5篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1974年 | 6篇 |
1972年 | 2篇 |
1971年 | 3篇 |
1969年 | 2篇 |
1963年 | 2篇 |
排序方式: 共有771条查询结果,搜索用时 296 毫秒
761.
762.
Senescence of Detached Fern Leaves 总被引:1,自引:0,他引:1
Biswal Basanti; N. K. Choudhury; Sahu Prativa; U. C. Biswal 《Plant & cell physiology》1983,24(7):1203-1208
Detached fern leaves show a loss in the content of pigments,protein and a decline in 2,6-dichlorophenol indophenol Hillreaction of isolated chloroplasts during aging. Light treatmentof leaves could considerably retard aging induced loss in 2,6-dichlorophenolindophenol photoreduction but it exhibits less effect on pigmentand protein loss. (Received February 7, 1983; Accepted July 14, 1983) 相似文献
763.
Microbiology - Microbiota of the fish gut contains many beneficial bacteria that can be used as probiotics in aquaculture. In this study, several in vitro assays along with an in vivo safety... 相似文献
764.
Isolation and properties of an esterase isoenzyme of rat serum 总被引:1,自引:0,他引:1
S R Choudhury 《The Histochemical journal》1974,6(4):369-372
765.
Atish Barua Pritha Choudhury Joy Krishna Maity Sukhendu Bikash Mandal Suvra Mandal 《Free radical research》2019,53(1):57-67
Therapeutic efficacy of nucleoside analogues (NAs) like Gemcitabine, 5-fluorouracil in cancer treatment is already well established. Most of the known NAs are highly toxic to normal cells due to its non-specific action; thus searching for non-toxic NAs are still going on. For that purpose we have synthesised nine different NAs by alteration of their structural and functional groups. The aim of present study is to investigate the therapeutic potential of NAs against mice bearing breast adenocarcinoma cells at IC50 dose for 10 days treatment schedule. Results of the present study showed that, among the seven nucleoside analogues, NA-7 and NA-9 showed maximum therapeutic efficacy in controlling cancer cells by inhibiting cell proliferation and inducing apoptosis without any adverse effects to normal host cells. Additionally, NAs significantly decreased the tumour burden and enhanced survivability of host through generation of reactive oxygen species in tumour cells. These ultimately led to DNA damage, depolarisation of mitochondrial membrane potential and apoptosis in tumour cells. To find out the molecular mechanisms, we showed that administration of NA-7 and NA-9, down- regulating the expression of Bcl-2, cyclin D1, C-myc, P-21 and up-regulating the expression of P-53, Cyt-c, Bax, caspase-3 and caspase-9. The results suggest that NA-7 and NA-9 exhibits significant antitumor activity than 5-fluorouracil by modulating the cell cycle checkpoints and inducing apoptosis in Ehrlich ascites carcinoma (EAC)-bearing mice. Additionally, NA-7 and NA-9 did not show any clastogenic effect on bone marrow cells at sub-lethal dose. Thus, the present study clearly suggested therapeutic benefit of NAs by augmenting anticancer efficacy and diminishing toxicity to the host. 相似文献
766.
767.
A Choudhury 《Folia primatologica; international journal of primatology》1989,52(1-2):88-92
768.
K. M. Pruss A. Marcobal A. M. Southwick D. Dahan S. A. Smits J. A. Ferreyra S. K. Higginbottom E. D. Sonnenburg P. C. Kashyap B. Choudhury L. Bode J. L. Sonnenburg 《The ISME journal》2021,15(2):577
Microbiota-accessible carbohydrates (MACs) are powerful modulators of microbiota composition and function. These substrates are often derived from diet, such as complex polysaccharides from plants or human milk oligosaccharides (HMOs) during breastfeeding. Host-derived mucus glycans on gut-secreted mucin proteins serve as a continuous endogenous source of MACs for resident microbes; here we investigate the potential role of purified, orally administered mucus glycans in maintaining a healthy microbial community. In this study, we liberated and purified O-linked glycans from porcine gastric mucin and assessed their efficacy in shaping the recovery of a perturbed microbiota in a mouse model. We found that porcine mucin glycans (PMGs) and HMOs enrich for taxonomically similar resident microbes. We demonstrate that PMGs aid recovery of the microbiota after antibiotic treatment, suppress Clostridium difficile abundance, delay the onset of diet-induced obesity, and increase the relative abundance of resident Akkermansia muciniphila. In silico analysis revealed that genes associated with mucus utilization are abundant and diverse in prevalent gut commensals and rare in enteric pathogens, consistent with these glycan-degrading capabilities being selected for during host development and throughout the evolution of the host–microbe relationship. Importantly, we identify mucus glycans as a novel class of prebiotic compounds that can be used to mitigate perturbations to the microbiota and provide benefits to host physiology.Subject terms: Microbial ecology, Diseases 相似文献
769.
B. Choudhury 《International Journal of Anthropology》1994,9(4):303-308
Variation in colour-blindness in some of the populations of North-East India has been examined. The people of North-East India
are found to be extremely variable with regard to this trait, the frequency ranging from 0 to 8.05%. An attempt has also been
made to examine the present findings in light of the hypothesis put forward by Post (1962a,b) and others about selection relaxation. 相似文献
770.
The stem bark of Xylopia aethiopica has yielded four diterpenes, two of them novel. Three of the diterpenes were identified as (?)-kaur-16-en-19-oic acid and its 7-oxo and 7β-hydroxy derivatives. The fourth was the novel kolavane derivative 2-oxo-kolav-3,13-dien-15-oic acid, a type of compound not previously recorded in the Annonaceae. 相似文献