全文获取类型
收费全文 | 437篇 |
免费 | 16篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 37篇 |
妇产科学 | 9篇 |
基础医学 | 89篇 |
口腔科学 | 16篇 |
临床医学 | 63篇 |
内科学 | 49篇 |
皮肤病学 | 13篇 |
神经病学 | 14篇 |
特种医学 | 40篇 |
外科学 | 41篇 |
综合类 | 9篇 |
预防医学 | 29篇 |
眼科学 | 2篇 |
药学 | 31篇 |
肿瘤学 | 16篇 |
出版年
2021年 | 3篇 |
2020年 | 7篇 |
2018年 | 7篇 |
2017年 | 4篇 |
2016年 | 4篇 |
2015年 | 14篇 |
2014年 | 8篇 |
2013年 | 11篇 |
2012年 | 13篇 |
2011年 | 13篇 |
2010年 | 20篇 |
2009年 | 18篇 |
2008年 | 8篇 |
2007年 | 19篇 |
2006年 | 36篇 |
2005年 | 5篇 |
2004年 | 10篇 |
2003年 | 6篇 |
2002年 | 10篇 |
2001年 | 7篇 |
2000年 | 5篇 |
1999年 | 9篇 |
1998年 | 18篇 |
1997年 | 16篇 |
1996年 | 12篇 |
1995年 | 7篇 |
1994年 | 14篇 |
1993年 | 10篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 10篇 |
1989年 | 7篇 |
1988年 | 11篇 |
1987年 | 8篇 |
1986年 | 9篇 |
1985年 | 11篇 |
1984年 | 6篇 |
1982年 | 6篇 |
1981年 | 9篇 |
1980年 | 3篇 |
1979年 | 4篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1975年 | 5篇 |
1974年 | 3篇 |
1973年 | 4篇 |
1970年 | 3篇 |
1968年 | 5篇 |
1966年 | 2篇 |
1957年 | 2篇 |
排序方式: 共有460条查询结果,搜索用时 531 毫秒
111.
Fedotova IuO Platonova NA Sapronov NS 《Eksperimental'naia i klinicheskaia farmakologiia》2006,69(3):53-57
The influence of chronic (14 days) administration of 5-HTIA receptors agonist--8-OH-DPAT (0.05 mg/kg, s.c.) and 5-HT(1A) receptors antagonist NAN-190 (0.1 mg/kg, i.p.) alone or in a combination with 17beta-estradiol (0.5 mg on each animal, i.m.) for on depressive behavior and expression of 5-HT(1A)-, 5-HT(2A)-, 17beta- estradiol receptors mRNAs was estimated in hippocampus in adult ovariectomized (OVX) female rats. The model of depression in rats was carried out in Porsolt test. The measurement of expression of 5-HT(1A)-, 5-HT(2A)-, 17beta-estradiol receptors mRNAs in the hippocampus was performed by semiquantitative RT-PCR. In Porsolt test 17beta-estradiol in OVX rats reduced time immobility to some extent. 8-OH-DPAT alone significantly decreased time immobility in OVX rats. Chronic 8-OH-DPAT administration in a combination with 17beta-estradiol in OVX females resulted in potentiated antidepressive effect. Simultaneously, 8-OH-DPAT induced significant increase of 5-HT(1A)-, 5-HT(2A)-receptors mRNAs expression and decrease of 17beta-estradiol receptor mRNA expression in hippocampus in OVX rats as compared to the control. The data obtained indicate a close interaction of the ovary hormonal and serotonergic systems of the brain in mechanisms of depression. 相似文献
112.
Computer simulation in conjunction with medical thermography as an adjunct tool for early detection of breast cancer 总被引:1,自引:0,他引:1
Background
Mathematical modelling and analysis is now accepted in the engineering design on par with experimental approaches. Computer simulations enable one to perform several 'what-if' analyses cost effectively. High speed computers and low cost of memory has helped in simulating large-scale models in a relatively shorter time frame. The possibility of extending numerical modelling in the area of breast cancer detection in conjunction with medical thermography is considered in this work.Methods
Thermography enables one to see the temperature pattern and look for abnormality. In a thermogram there is no radiation risk as it only captures the infrared radiation from the skin and is totally painless. But, a thermogram is only a test of physiology, whereas a mammogram is a test of anatomy. It is hoped that a thermogram along with numerical modelling will serve as an adjunct tool. Presently mammogram is the 'gold-standard' in breast cancer detection. But the interpretation of a mammogram is largely dependent on the radiologist. Therefore, a thermogram that looks into the physiological changes in combination with numerical simulation performing 'what-if' analysis could act as an adjunct tool to mammography.Results
The proposed framework suggested that it could reduce the occurrence of false-negative/positive cases.Conclusion
A numerical bioheat model of a female breast is developed and simulated. The results are compared with experimental results. The possibility of this method as an early detection tool is discussed.113.
K. M. Kilbride F. L. Paveglio A. L. AltstattRID=""ID="" <E>Present address:</E> Chiswell Lane Silver Spring MD USA W. G. Henry C. A. JanikRID=""ID="" <E>Present address:</E> Palo Verde Albuquerque NM USA 《Archives of environmental contamination and toxicology》1998,35(2):236-248
Throughout the western United States, studies have identified various detrimental effects of contaminants to aquatic biota
from the use of agricultural drainage water for management of arid wetlands. However, little is known about the relative contributions
of contaminant loading from pollutants dissolved in water compared with those carried by drifting material (e.g., detritus) associated with drainage water. Consequently, we determined loading rates for contaminants dissolved in water and
those incorporated by drifting material for drainage (Diagonal Drain) as well as fresh (S-Line Canal) water used for wetland
management at Stillwater National Wildlife Refuge (SNWR), Nevada during the early, middle, and late periods of the irrigation
season (June through mid-November) in 1993. We found loading rates for trace elements throughout the irrigation season were
almost entirely (> 98%) associated with contaminants dissolved in the water rather than incorporated by drift. Although drift
contributed little to the total loading for trace elements to SNWR wetlands, contaminant concentrations were much greater
in drift compared with those dissolved in water. Loading rates for dissolved As, B, Hg, and total dissolved solids (TDS) differed
among periods for the Diagonal Drain. Along the Diagonal Drain, loading rates for dissolved As, B, Hg, Mo, unionized ammonia
(NH3-N), TDS, and Zn differed among its three sampling sites. B was the only trace element with differences in loading rates for
drift among periods from the Diagonal Drain. In contrast, loading rates for As, B, Cr, Cu, Hg, Se, and Zn in drift differed
among periods for the S-Line Canal. Along Diagonal Drain, loading rates in drift for B (middle and late periods), Cr, Cu,
and Zn differed among sites. Hg (xˉ ≥ 12.0 ng/L) and NH3-N (xˉ ≥ 0.985 mg/L) dissolved in water as well as B (xˉ ≥ 97.4 μg/g DW) and Hg (xˉ ≥ 0.461 μg/g DW) in drift from the Diagonal
Drain and S-Line Canal exceeded screening levels (SLs) for protection of aquatic biota throughout the irrigation season. Dissolved
As (xˉ ≥ 0.0426 mg/L) in water from the Diagonal Drain during all periods exceeded the SL for protection of aquatic biota.
Dissolved B (xˉ = 1.03 mg/L) in water from the Diagonal Drain during the early period exceeded the SL for protection of aquatic
biota.
Received: 18 September 1997/Accepted: 5 February 1998 相似文献
114.
Morizono H; Listrom CD; Rajagopal BS; Aoyagi M; McCann MT; Allewell NM; Tuchman M 《Human molecular genetics》1997,6(6):963-968
Although many mutations in the ornithine transcarbamylase gene have been
correlated with 'late onset' of hyperammonemia in patients, the effects of
these mutations on enzyme function are largely unknown. Three recurrent
mutations (R40H, R277W and R277Q) found in patients with 'late onset'
disease were incorporated into 'mature' human ornithine transcarbamylase
cDNA and overexpressed in Escherichia coli. The three recombinant mutant
enzymes were purified to homogeneity on an affinity column and their
biochemical characteristics were compared to the wild type enzyme. The
R277W and R277Q mutants display markedly reduced affinity for L-ornithine,
loss of substrate inhibition, alkaline shift of pH optimum, and reduced
thermal stability compared to the wild type enzyme. These differences,
particularly the reduced affinity for L-ornithine, are sufficient to
account for their biochemical effects. In contrast, the 'mature' R40H
mutant was biochemically indistinguishable from the wild type enzyme in
vitro.
相似文献
115.
Hiroaki Watanabe Yasuko Minagawa Ichiro Suzuki Kaori Kitamura Yumi Watanabe Keiko Kabasawa Kseniia Platonova Aya Hinata Kazutoshi Nakamura 《Fukushima journal of medical science》2021,67(3):128
Introduction: Secular changes in hip fracture incidence have been reported in the last few decades in Japan, but whether long-term bone mineral density (BMD) is also changing is unclear. This study aimed to determine whether BMD of Japanese women has changed over time. Methods: Subjects were 10,649 adult women who underwent BMD measurement in a health check-up population in Niigata, Japan, between 1995 and 2013. BMD of the distal, non-dominant forearm was measured by dual-energy X-ray absorptiometry. Demographic information and BMI were also obtained. Secular trends were determined by linear regression analysis. Results: BMD of subjects in their 40’s decreased significantly in the age-adjusted model (P for trend=0.0162), but not in the age- and BMI-adjusted model (P for trend=0.2171). BMD of subjects in their 50’s decreased marginally in the age-adjusted model (P for trend=0.0535), but not in the age- and BMI-adjusted model (P for trend=0.6601). BMDs of subjects in their 30’s and 60’s did not significantly change, while BMIs of subjects in their 40’s-60’s decreased significantly. Conclusions: A secular decrease in BMD, partly attributed to decreases in BMI, was observed in middle-aged Japanese women from 1995 to 2013. Measures to help maintain suitable BMI will be necessary to prevent a decrease in BMD among women. 相似文献
116.
L M Fregatova S A Shavva G G Platonova A A Golovacheva B V Afanas'ev 《Voprosy onkologii》1999,45(4):380-383
The potential of peripheral blood stem cell (PBSC) mobilization with granulocyte (G-CSF) and granulocyte-macrophage (GM-CSF) colony-stimulating factors of chemotherapy has been assessed in patients with tumor or hematological disease. The study was intended to aid PBSC transplantation. It was shown that G-CSF administration increased the number of leukocytes in leukemia patients dramatically while mononuclear cell and colony-forming unit levels in G-CSF-mobilised PBSC were significantly higher than those collected with GM-CSF or chemotherapy. 相似文献
117.
Background: The incidence of pseudoaneurysm has increased due to the large number of vascular procedures performed and the widespread use of anticoagulation therapy during procedures. Non-invasive methods for management of pseudoaneurysms comprise of ultrasound guided compression (USGC), thrombin therapy, arterial embolisation and endovascular stent graft insertion. We discuss our experience in the management of fourteen cases of pseudoaneurysms using non surgical techniques. 相似文献
118.
119.
The study of the antigenic composition of hemagglutinins of influenza H3N2 viruses isolated during epidemic outbreaks in 1979-1983, carried out by means of monospecific antibodies to individual antigenic determinants, showed heterogeneity of the antigenic structure of epidemically active variants. Some variants were antigenically identical to A/Bangkok/1/79 virus. Hemagglutinin structure of A/Shanghai/31/80, A/Philippines/2/82 and the like was found to contain a qualitatively new antigenic determinant heretofore undetectable in H1N1, H3N2 viruses. 相似文献
120.