全文获取类型
收费全文 | 2350篇 |
免费 | 114篇 |
国内免费 | 4篇 |
出版年
2023年 | 21篇 |
2022年 | 27篇 |
2021年 | 76篇 |
2020年 | 46篇 |
2019年 | 51篇 |
2018年 | 86篇 |
2017年 | 58篇 |
2016年 | 70篇 |
2015年 | 102篇 |
2014年 | 127篇 |
2013年 | 178篇 |
2012年 | 179篇 |
2011年 | 159篇 |
2010年 | 105篇 |
2009年 | 105篇 |
2008年 | 100篇 |
2007年 | 90篇 |
2006年 | 87篇 |
2005年 | 74篇 |
2004年 | 62篇 |
2003年 | 60篇 |
2002年 | 62篇 |
2001年 | 49篇 |
2000年 | 46篇 |
1999年 | 38篇 |
1998年 | 17篇 |
1997年 | 7篇 |
1996年 | 19篇 |
1995年 | 9篇 |
1994年 | 14篇 |
1993年 | 6篇 |
1992年 | 21篇 |
1991年 | 22篇 |
1990年 | 16篇 |
1989年 | 27篇 |
1988年 | 24篇 |
1987年 | 23篇 |
1986年 | 17篇 |
1985年 | 18篇 |
1984年 | 21篇 |
1983年 | 8篇 |
1982年 | 15篇 |
1981年 | 9篇 |
1980年 | 12篇 |
1979年 | 20篇 |
1978年 | 13篇 |
1977年 | 14篇 |
1976年 | 9篇 |
1975年 | 8篇 |
1970年 | 5篇 |
排序方式: 共有2468条查询结果,搜索用时 15 毫秒
41.
P Srivastava S K Puri G P Dutta V C Pandey 《International journal for parasitology》1992,22(2):243-245
Plasmodium knowlesi (a simian malarial parasite) infection resulted in elevation of hepatic oxidative stress in monkeys. Further, the antioxidant defence system of the host was also noticeably affected. The infected monkeys showed a marked increase in the levels of superoxide (O2-), lipid peroxidation (LPO), glutathione (GSH) and xanthine oxidase (XO), and decreased levels of superoxide dismutase (SOD) and catalase. Oral administration of chloroquine (20 mg kg body wt-1 for 3 days) to infected monkeys caused recovery trends in oxidative stress and antioxidant defences to almost normal a week after cessation of drug treatment. 相似文献
42.
The effect of population size, redox potential, exogenous ATP and complexing agents on Cu uptake by free and immobilized cyanobacteriumNostoc calcicola
Bréb. has been studied. Cu uptake was regulated by the population size. In such comparisons, the immobilized cells had a greater
longevity. Low pH conditions enhanced Cu uptake. Exogenous ATP (10 μmol/L) supplied to dark-grown free and immobilized cells
did not support Cu uptake to the extent of light-grown cells. Experiments involving natural as well as synthetic complexing
agents clearly established the superiority of soil extract and spent medium over EDTA (10 μmol/L), in sequestering Cu in free
as well as immobilized cells. 相似文献
43.
F M Salzano F L Black S M Callegari-Jacques S E Santos T A Weimer M A Mestriner R R Kubo J P Pandey M H Hutz 《American journal of physical anthropology》1991,85(1):51-60
Data on 31 genetic systems were obtained for 421 individuals belonging to the Arara, Araweté, Mundurucu, and Jamamadi tribes of northern Brazil. The Jamamadi depart farthest, and the Mundurucu least, from South American Indian averages. These data are analyzed together with those of 24 other Amazonian groups. Genetic distances and corresponding dendrograms indicate a cluster of 14 related tribes living north of the Amazon river. These genetic results show only a modest correlation with linguistic and geographic relationships among these groups. 相似文献
44.
The pattern of arterial supply to the various parts (clavicular, sternocostal and aponeurotic) of the pectoralis major muscle was studied in 7 cadaver dissections and 10 angiograms by injecting a radio-opaque substance. Three main arteries supplied the muscle, i.e. the pectoral branch of the thoracoacromial trunk (TAT-PB), the lateral thoracic artery and the perorating branch of the internal thoracic artery, supported by other branches of the TAT and the superior thoracic artery. It is observed that the TAT-PB, a chief vascular pedicle, anastomoses freely with other arteries and supplies most parts of the muscle. The present study is mainly focussed on the exclusion of the chief vascular pedicle of muscle to eliminate the confusion of previous studies and prevent the unnecessary hindrance and complications of the muscle flap. 相似文献
45.
Using agar gel électrophoresis, the number and relative mobility of seric protein fractions has been determined for twelve species of fishes belonging to the Elasmobranchii, Dipnoi and Actinopterygii.The study of relative mobilities has shown both similitudes and divergences between some of the proteinograms. Immunoelectrophoretic cross tests using the twelve sera and five antisera have shown that these similitudes did not result from protein homology and thus agar gel electrophoresis could not be used to determine phylogenetic relationships between the species considered.
Laboratoire d'Hydrobiologie et de Pisci culture, Université de Kinshasa (Zaïre) 相似文献
46.
A new alkaloid, 3-methoxy-4,6-dihydroxymorphinandien-7-one, and norsinoacutine have been isolated from extracts of Croton bonplandianum. 相似文献
47.
48.
49.
A strain of Fusarium solani (Mart.) Sacc. (IMI-216517), isolated from a patient of mycotic keratitis, produced experimental keratomycosis in albino rabbit cornea and survived in internal tissues of albino mice for varying periods. Alantolactone, isolated from the plant — Inula racemosa Hook. f. exhibited marked in vitro fungistatic activity against this strain of F. solani at 100–200 g/ml concentrations. The strain was less sensitive to amphotericin B and showed more acid than alkaline proteinase and phosphatase activities.Communication No. 2526. 相似文献
50.