全文获取类型
收费全文 | 619篇 |
免费 | 34篇 |
国内免费 | 45篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 39篇 |
妇产科学 | 36篇 |
基础医学 | 49篇 |
口腔科学 | 13篇 |
临床医学 | 88篇 |
内科学 | 123篇 |
皮肤病学 | 8篇 |
神经病学 | 32篇 |
特种医学 | 141篇 |
外科学 | 37篇 |
综合类 | 16篇 |
预防医学 | 19篇 |
眼科学 | 7篇 |
药学 | 69篇 |
中国医学 | 1篇 |
肿瘤学 | 19篇 |
出版年
2021年 | 2篇 |
2019年 | 1篇 |
2018年 | 5篇 |
2017年 | 3篇 |
2016年 | 2篇 |
2015年 | 7篇 |
2014年 | 11篇 |
2013年 | 19篇 |
2012年 | 11篇 |
2011年 | 12篇 |
2010年 | 30篇 |
2009年 | 24篇 |
2008年 | 11篇 |
2007年 | 37篇 |
2006年 | 17篇 |
2005年 | 15篇 |
2004年 | 8篇 |
2003年 | 9篇 |
2002年 | 5篇 |
2001年 | 6篇 |
2000年 | 9篇 |
1999年 | 12篇 |
1998年 | 45篇 |
1997年 | 34篇 |
1996年 | 38篇 |
1995年 | 24篇 |
1994年 | 17篇 |
1993年 | 22篇 |
1992年 | 13篇 |
1991年 | 12篇 |
1990年 | 19篇 |
1989年 | 34篇 |
1988年 | 33篇 |
1987年 | 25篇 |
1986年 | 20篇 |
1985年 | 16篇 |
1984年 | 8篇 |
1983年 | 11篇 |
1982年 | 12篇 |
1981年 | 8篇 |
1980年 | 7篇 |
1979年 | 4篇 |
1978年 | 6篇 |
1977年 | 12篇 |
1976年 | 7篇 |
1975年 | 5篇 |
1971年 | 2篇 |
1969年 | 1篇 |
1967年 | 2篇 |
1966年 | 2篇 |
排序方式: 共有698条查询结果,搜索用时 15 毫秒
1.
2.
Emmanuelle Ponty Michel Carton Georges Soula Gillcs Favre Rachid Benaniba Andre Boneu Henriette Lucot 《International journal of cancer. Journal international du cancer》1993,54(3):411-417
Since there is strong evidence of a preferential LDL accumulation in tumor cells, LDL might be of interest for tumor imaging. We have tested the ability of 99mTc-LDL in tumor imaging with B16-melanoma-bearing mice as a model for further applications in human studies. The LDL fixation rate was higher with 99mTc-labeled LDL than with 125I labeled LDL. Since technetium-99m remains trapped in the cells, 99mTc-LDL is a well-adapted radioligand because of information given by this radiotracer on the receptor metabolism. We observed that, at early growth stages, the tumor took up the LDL at a maximal rate, suggesting differences in cholesterol metabolism as a function of tumor growth. Accumulation of label in the tumor area was perfectly observable in tumor-bearing mice on scintigraphic images. Computerized quantification of the regions of interest (as well as biodistribution studies including killing of the animals) showed a 1.81 -fold increase in uptake by the tumor as compared to the liver and a 28-fold increase as compared with corresponding normal tissue (muscle of the left leg) at day 8 of tumor growth. These data give strong support to the value of this non-invasive method in visualizing and quantifying the tissue LDL uptake in vivo, including the precise information provided by nuclear scintigraphy on the distribution of the radiolabeled LDL in the different tissues. 99mTc-LDL could be an efficient tool for further diagnostic or therapeutic exploration in cancer patients. 相似文献
3.
4.
5.
Sperm quality in Hodgkin's disease versus non-Hodgkin's lymphoma 总被引:3,自引:4,他引:3
Botchan A; Hauser R; Gamzu R; Yogev L; Lessing JB; Paz G; Yavetz H 《Human reproduction (Oxford, England)》1997,12(1):73-76
The study was conducted to determine the deleterious effect of lymphoma
disease on spermatogenesis and to evaluate the possibility that the disease
is mediated primarily by inherent mechanisms in Hodgkin's disease and
non-Hodgkin's lymphoma patients. A total of 89 patients with lymphoma
disease (Hodgkin's and non-Hodgkin's) were referred for sperm preservation
prior to adjuvant treatments. A comparison was made of pre- and post-thaw
sperm quality between lymphoma patients and healthy volunteers who applied
for sperm donation. This was followed by further assessment of the
differences between patients with Hodgkin's disease and non-Hodgkin's
lymphoma in terms of sperm variables, clinical parameters and blood hormone
concentrations. It was found that patients with lymphoma disease had
significantly impaired pre-freeze and post-thaw sperm quality compared with
that of healthy volunteers. Patients with non-Hodgkin's lymphoma had
spermatozoa of higher quality than patients with Hodgkin's disease. No
differences were found in the clinical or hormonal parameters between these
two groups. As expected, reduced testicular size and abnormal testicular
consistency were correlated with decreased sperm quality. The mere presence
of cancer disease has a direct negative effect on spermatogenesis, which is
probably not related to incidental side-effects. A variable degree of
impairment should be expected with different categories of cancer.
相似文献
6.
Preweaning guinea pigs were placed into a test cage either alone or with their mother for 10, 30, or 90 min, or were placed into the cage alone for 24 hr. At 30 and 90 min, pups exhibited higher plasma levels of ACTH if alone than if with the mother. This effect was not apparent at 10 min, and ACTH levels of pups tested alone were no longer greater than baseline levels at 24 hr. These results provide further evidence that brief maternal separation can serve as a potent stimulus for activation of the hypothalamo-pituitary-adrenal system in this species. Plasma epinephrine and norepinephrine concentrations of pups tested alone were not significantly greater than those of pups tested with their mothers. But, pups tested alone for 10 and 30 min did show an elevation of epinephrine and norepinephrine over baseline levels. That is, the combined influence of separation and other aspects of the manipulation (e.g., exposure to novelty) evoked sympathetic responses. In addition, the number of vocalizations emitted by pups during the first 30 min of isolation in the test cage was positively correlated with concentrations of ACTH, epinephrine, and norepinephrine following 24 hr of this procedure, but not following 90 min or at baseline. Thus, the initial behavioral response appears to be predictive of the levels of both hypothalamo-pituitary-adrenal and sympathetic activity 24 hr after separation is initiated. 相似文献
7.
8.
双波长薄层扫描法测定痛得安胶囊中新乌头碱的含量 总被引:3,自引:0,他引:3
目的:建立痛得安胶囊中新乌头碱的含量测定方法。方法:采用双波长薄层扫描法,以正己烷-乙酸乙酯-无水乙醇-氨水(12:8:2.5:0.5)为展开剂,碘化饿钾试液为显色剂,测定该制剂中新乌头碱的含量。结果:线性范围为1~6ug。平均回收率为94.80%,RSD为2.03%。结论:本法操作简便。结果可靠。实用,适合该制剂中新乌头碱的含量测定。 相似文献
9.
Delarue E Collinet P Sabban F Lucot JP Cosson M 《Gynécologie, obstétrique & fertilité》2008,36(10):1043-1049
Even if genital prolapse does particularly affect the elder woman, we often have to face a surgical demand with conservation of the uterus from a patient less than 50 years. Before making the decision of treating a non life-threatening symptom by a specific surgical technique, it is important to ask who should be operated and when. Then, the route of the surgery has to be chosen considering that the woman wants to preserve her fertility. In the past decade, some surgical acts, like the sacrohysteropexy, were known as having poorer results if the women got pregnant. Thus, if there was a persistent childbearing desire, more interventions allowing pregnancy (like the Manchester's or the Richardson's procedures) were preferred. Nowadays, the sacrohysteropexy is considered as the gold standard technique, but one question is coming out: could we substitute this traditional surgery by a vaginal repair with meshes? Despite the big diversity of the so-called "sacrohysteropexy", we think that it remains the first choice technique to cure a young woman. Vaginal meshes have too high a rate of morbidity (especially on sexual activity) to be considered as the best surgical treatment. But this question could probably find another answer in the future, when all the studies about the component of the meshes will be finished. 相似文献
10.
Emily A. Smith Abigail L. Schwartz James B. Lucot 《Journal of pharmacological and toxicological methods》2013,67(1):45-49
IntroductionAnalysis of catecholamines in small samples of urine is difficult and sensitive to stress. Current techniques require pooling of samples or expensive separation by double mass spectrometry. A method for extraction of unconjugated catecholamines in 20 μL urine samples has been developed using alumina extraction prior to separation by high performance liquid chromatography (HPLC) and electrochemical detection (ECD).MethodsThree murine experiments tested the application of the procedure. In the first, collection occurred in the morning and evening prior to handling, and in the morning after three days of handling. In the second, passively obtained urine was compared to stressfully obtained urine in the same mice. Finally, basal collections were compared to urinary catecholamine levels 15 and 30 min into novel cage stress. Urine was extracted alongside 2,3-dihydroxybenzoic acid (DHBA) internal standard via alumina and brought to pH 8.5 with tris buffer. The mixture underwent two wash steps for depuration and eluted with perchloric acid for analysis on HPLC with ECD.ResultsThis novel extraction method using low amounts of urine yielded 48% recovery in the samples and 60% recovery in the standard extraction on average. With a signal to noise ratio of 3:1, the limit of detection (LOD) of a standard is 1.2 pg/mL, which allows for the detection of 3.6 pg/mL in urine or 72 fg in a 20 μL sample. Thus resting catecholamine levels are 216 times higher than the LOD. Unconjugated norepinephrine and epinephrine levels were significantly increased 15 min after novel cage stress and epinephrine remained elevated after 30 min, but did not show significant differences when comparing collection time, handling exposure, or specific collection technique.DiscussionThe technique is an effective measure for sympathetic activity in micro samples, with a limit of detection in the attomole range for 20 μL samples. 相似文献