全文获取类型
收费全文 | 13610篇 |
免费 | 114篇 |
国内免费 | 122篇 |
专业分类
教育 | 8973篇 |
科学研究 | 1679篇 |
各国文化 | 89篇 |
体育 | 1718篇 |
综合类 | 19篇 |
文化理论 | 170篇 |
信息传播 | 1198篇 |
出版年
2021年 | 79篇 |
2020年 | 155篇 |
2019年 | 205篇 |
2018年 | 949篇 |
2017年 | 944篇 |
2016年 | 720篇 |
2015年 | 232篇 |
2014年 | 246篇 |
2013年 | 1570篇 |
2012年 | 281篇 |
2011年 | 517篇 |
2010年 | 468篇 |
2009年 | 358篇 |
2008年 | 387篇 |
2007年 | 487篇 |
2006年 | 200篇 |
2005年 | 251篇 |
2004年 | 513篇 |
2003年 | 434篇 |
2002年 | 361篇 |
2001年 | 402篇 |
2000年 | 256篇 |
1999年 | 162篇 |
1998年 | 106篇 |
1997年 | 106篇 |
1996年 | 96篇 |
1995年 | 107篇 |
1994年 | 101篇 |
1993年 | 77篇 |
1992年 | 152篇 |
1991年 | 119篇 |
1990年 | 135篇 |
1989年 | 149篇 |
1988年 | 110篇 |
1987年 | 129篇 |
1986年 | 120篇 |
1985年 | 135篇 |
1984年 | 120篇 |
1983年 | 123篇 |
1982年 | 96篇 |
1981年 | 81篇 |
1980年 | 91篇 |
1979年 | 135篇 |
1978年 | 87篇 |
1977年 | 72篇 |
1976年 | 91篇 |
1975年 | 65篇 |
1974年 | 72篇 |
1973年 | 68篇 |
1971年 | 66篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
971.
Bhawana Nigam S. P. Joshi Seema Nagar Rajesh Chavan D. Pendharkar 《Indian journal of clinical biochemistry : IJCB》1996,11(2):124-128
The analysis of biochemical parameters in 162 patients with various neoplastic disorders along with 50 normal subjects showed significant rise in serum alkaline phosphatase and lactate dehydrogenase as compared to normal subjects. 21 patients with other monoclonal gammopathies which include infection and immunological diseases were also studied. Parameters such as serum calcium, uric acid, total protein, albumin and globulin were also analyzed in 42 (26%) cases of multiple myeloma, 27 (17%) cases of gastro-intestinal malignancies, 22 (14%) cases of urogenital malignancies, 11 (6%) cases of carcinoma breast, 4 (2%) cases of bone tumors, 21 (12%) cases of other monoclonal gammopathies, including 7 (4%) cases of infection and 14 (8%) cases of immunological diseases. The results indicate use of enzymes alkaline phosphatase and lactate dehydrogenase in neoplastic disorders. 相似文献
972.
S. Kaushik S. S. Trivedi A. Jain J. Bhattacharjee 《Indian journal of clinical biochemistry : IJCB》2002,17(2):68-73
Colostrum, the mammary secretion during first 2–4 days of lactation, provides all the essential components of nutrition and
passive immunity required by the newborn. Pregnancy induced hypertension (PIH), glucose intolerance and anaemia are common
medical complications observed during pregnancy in Indian women and their effects were studied on the composition of colostrum
collected within 24 hours of delivery from lactating women included in the study. PIH during pregnancy significantly decreased
colostrum IgA and total proteins, but showed a significant increase in K+ levels, where as women with glucose intolerance showed a significant decrease in total lipids and lactose and an increase
in Na+ levels in colostrum compared to normal controls. The group with anaemia also showed a significant decrease in colostrum IgA
and total protein levels when compared with the control group. Awareness about the changes that occur in the composition of
colostrum during complicated pregnancies can be an important and useful tool for preventive and protective paediatrics. 相似文献
973.
Artificial Life (ALife) has two goals. One attempts to describe fundamental qualities of living systems through agent based
computer models. And the second studies whether or not we can artificially create living things in computational mediums that
can be realized either, virtually in software, or through biotechnology. The study of ALife has recently branched into two
further subdivisions, one is “dry” ALife, which is the study of living systems “in silico” through the use of computer simulations,
and the other is “wet” ALife that uses biological material to realize what has only been simulated on computers, effectively
wet ALife uses biological material as a kind of computer. This is challenging to the field of computer ethics as it points
towards a future in which computer and bioethics might have shared concerns. The emerging studies into wet ALife are likely
to provide strong empirical evidence for ALife’s most challenging hypothesis: that life is a certain set of computable functions
that can be duplicated in any medium. I believe this will propel ALife into the midst of the mother of all cultural battles
that has been gathering around the emergence of biotechnology. Philosophers need to pay close attention to this debate and
can serve a vital role in clarifying and resolving the dispute. But even if ALife is merely a computer modeling technique
that sheds light on living systems, it still has a number of significant ethical implications such as its use in the modeling
of moral and ethical systems, as well as in the creation of artificial moral agents. 相似文献
974.
Dietary restriction (DR) also called dietary control or calorie restriction is reported to have many advantages with regard
to human health. It leads to suppression of obesity, mitigates free radicals and increases available antioxidants which are
accounted for extending the life span of individuals. DR is also reported to induce synthesis of heat shock proteins in animals
as a control mechanism against stress. Further, it is known to play a significant role in decreasing toxicity and lethality
due to a variety of toxic chemicals and drugs by stimulating tissue repair damaged by the toxicants leading to restoration
of intact organ and its functions. Moreover, extensive work done on animals indicate DR has an important role in suppressing
certain types of cancer. In this review an effort is made to highlight the various advantages of DR from the point of human
health perspective. 相似文献
975.
Ajay Kumar T. A. Venkita Subramanian Usha P. Sharma 《Indian journal of clinical biochemistry : IJCB》1992,7(2):165-168
Protein fraction termed P2 was obtained from sonicates of Mycobacterium smegmatis, subjected to ammonium sulphate precipitation. P2 fraction was further fractionated into 4 fractions (PeakI-IV) by DEAE cellulose ion-exchange chromatography. ELISA was performed
on the sera of 104 tuberculous cases and 62 controls, using P2 fractions Peak I as test antigens. Though the mean ELISA values in tuberculous cases were higher than the controls, no statistically
significant difference was found between the two. Antigens P2, Peak I and IV were tested on Western blots with pooled sera from tuberculous cases as well as controls. P2 fraction, Peak-I and IV were separated on PAGE-SDS, electroblotted onto nitrocellulose Sheets and the blots were subjected
to ELISA. Peak IV appeared as a single band (M.W. 55,000). P2 fraction exhibited some discriminatory bands on development of blots. 相似文献
976.
In this paper, an algorithm is developed to apply Hann, Hamming, Blackman and related windows directly in the transform domain for the discrete cosine transform and discrete sine transform. These algorithms are useful in applications where windowing is required in order to minimize edge effects caused by implicit symmetries in the transform domain that are not replicated in the real-world data. Examples of such applications include data communication, adaptive system identification and filtering, real-time analysis of financial market data, etc. Software implementations in C language are also given. 相似文献
977.
Praveen Sharma P. K. Sharma D.Sc. J. Pramod L. K. Kothari Rashmi Ranka Sushma Sharma 《Indian journal of clinical biochemistry : IJCB》1989,4(1):62-64
Sixteen weeks of chronic vitamin C deficiency, induced in guinea pigs by restricted vitamin C intake, resulted in a marked
increase in the serum total LDL- and VLDL- cholesterol, triglycerides and total lipids. HDL-cholesterol decreased resulting
in a highly significant increase in LDL/HDL ratio. The results reconfirm that vitamin C deficiency causes changes in blood
lipid profile which could promote atherogenesis. 相似文献
978.
979.
980.
M. V. R. Reddy R. Alli B. C. Harinath 《Indian journal of clinical biochemistry : IJCB》2000,15(1):127-135
Lymphatic filariasis caused mainly by infection fromWuchereria bancrofti andBrugia malayi remains as the major cause of clinical morbidity in tropical and subtropical countries. Development of vaccine against filarial infection can act as additional measure to the existing therapeutic and vector control methods in the control of this disease. The main hurdles in the development of anti-filarial vaccine are the strict primate specificity ofWuchereria bancrofti, the paucity of parasite material, the diversity of clinical manifestations and their associated complex immune responses, lack of clear understanding on host-parasite interactions and the mechanisms involved in protective immunity. However in the past few years, the information generated in immuno-epidemiological studies, correlated with observations in experimental animals suggests that a filarial vaccine is feasible. Initially live irradiated infective larvae have been successfully used to induce high level of protective immunity in several animal models. Applying diverse strategies, variety of purified or recombinant filarial antigens have been explored for their ability to induce protection in different host-parasite systems. Some of these targeted filarial antigens induced high level of resistance in experimental animals against challenge infections. More focussed studies on thorough characterization of parasitological and immunological changes associated with resistance induced by such candidate protective antigens and on delivery mechanisms and safety aspects will be crucial in their selection for possible use in humans. 相似文献