全文获取类型
收费全文 | 1861篇 |
免费 | 83篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 49篇 |
妇产科学 | 6篇 |
基础医学 | 219篇 |
口腔科学 | 59篇 |
临床医学 | 92篇 |
内科学 | 476篇 |
皮肤病学 | 39篇 |
神经病学 | 87篇 |
特种医学 | 49篇 |
外科学 | 373篇 |
综合类 | 4篇 |
预防医学 | 36篇 |
眼科学 | 27篇 |
药学 | 130篇 |
中国医学 | 7篇 |
肿瘤学 | 297篇 |
出版年
2023年 | 7篇 |
2022年 | 19篇 |
2021年 | 23篇 |
2020年 | 19篇 |
2019年 | 14篇 |
2018年 | 24篇 |
2017年 | 26篇 |
2016年 | 26篇 |
2015年 | 29篇 |
2014年 | 30篇 |
2013年 | 63篇 |
2012年 | 84篇 |
2011年 | 92篇 |
2010年 | 50篇 |
2009年 | 48篇 |
2008年 | 80篇 |
2007年 | 100篇 |
2006年 | 79篇 |
2005年 | 85篇 |
2004年 | 61篇 |
2003年 | 78篇 |
2002年 | 68篇 |
2001年 | 70篇 |
2000年 | 61篇 |
1999年 | 69篇 |
1998年 | 34篇 |
1997年 | 18篇 |
1996年 | 27篇 |
1995年 | 15篇 |
1994年 | 18篇 |
1993年 | 13篇 |
1992年 | 52篇 |
1991年 | 55篇 |
1990年 | 41篇 |
1989年 | 53篇 |
1988年 | 47篇 |
1987年 | 37篇 |
1986年 | 38篇 |
1985年 | 38篇 |
1984年 | 21篇 |
1983年 | 14篇 |
1982年 | 8篇 |
1979年 | 12篇 |
1978年 | 7篇 |
1977年 | 7篇 |
1976年 | 11篇 |
1972年 | 8篇 |
1971年 | 8篇 |
1969年 | 7篇 |
1966年 | 9篇 |
排序方式: 共有1953条查询结果,搜索用时 15 毫秒
1.
Masao Amari Katsuji Taguchi Minoru Iwahara K Shibuya Shiro Naoe 《Medical Electron Microscopy》2002,35(4):225-233
To elucidate the effect of fibroblast growth factor on the phenotypical conversion of fibroblasts to mesothelial cells, both immunohistochemical and ultrastructural examinations were carried out on cultured spheroids that were composed of fibroblasts obtained from the parietal pleura of rats with and without addition of antifibroblast growth factor receptor antibody. In the present study, antifibroblast growth factor receptor antibody was employed to block the effect of the autocrine component of fibroblast growth factor in the culture medium. Phenotypical conversion from fibroblast to mesothelial cells was clearly blocked in the experimental group, to which culture medium had been added with antifibroblast growth factor receptor antibody, whereas the control group, cultured without addition of antifibroblast growth factor receptor antibody, showed phenotypical conversion of fibroblasts that was confirmed by the development of macula adherens, microvilli, and positive expression of cytokeratin. These results indicate the possibility that fibroblast growth factor plays a key role in the process of phenotypic conversion of fibroblasts to regenerated mesothelial cells. 相似文献
2.
The anti-allergic activity of bryonolic acid (1) isolated from the cultured cells of Luffa cylindrica L. (Cucurbitaceae) was compared with that of glycyrrhetinic acid (2), the aglycone of glycyrrhizin from licorice. Compound 1, when administered to rats intraperitoneally at a dose of 600 mg/kg, inhibited homologous passive cutaneous anaphylaxis more strongly than 2 at the same dose. Compound 1 also significantly inhibited delayed hypersensitivity in mice which could not be inhibited by 2. In contrast to 2, 1 showed not only little toxicity but no visible side effects on mice, without impairing the activity of the hepatic enzyme (4,5 beta-dihydrocortisone:NADP+ delta 4-oxidoreductase) involved in steroid catabolism. 相似文献
3.
Fungal infections in cancer patients: An international autopsy survey 总被引:33,自引:0,他引:33
G. Bodey B. Bueltmann W. Duguid D. Gibbs H. Hanak M. Hotchi G. Mall P. Martino F. Meunier S. Milliken S. Naoe M. Okudaira D. Scevola J. van't Wout 《European journal of clinical microbiology & infectious diseases》1992,11(2):99-109
In an attempt to estimate the frequency of fungal infections among cancer patients, a survey of autopsy examinations was conducted in multiple institutions in Europe, Japan and Canada. Fungal infections were identified most often in leukemic patients and transplant recipients (25 % each). Fifty-eight percent of fungal infections were caused byCandida spp. and 30 % byAspergillus spp. There was considerable variability in the frequency of fungal infections in different countries. Nevertheless, this study clearly demonstrates that fungal infections represent a common complication in cancer patients, especially in patients with leukemia. 相似文献
4.
Susumu Akimoto Yuzo Furuya Koichiro Akakura Jun Shimazaki Haruo Ito 《International journal of urology》1997,4(6):580-582
Background :
The aim of this study was to investigate the influence of osteoarthritis of lumbar vertebrae on serum bone formation and resorption marker levels of patients with benign prostatic hypertrophy (BPH).
Methods :
Serum levels of carboxyterminal propeptide of type I procollagen (PICP), alkaline phosphatase (ALP), carboxyterminaltelopeptide of type I collagen (ICTP), and prostate-specific antigen (PSA) were examined in 40 patients with BPH, and the presence of osteoarthritis at the lumbar vertebrae of the patients was evaluated by plain x-ray-p.
Results :
Findings of osteoarthritis were observed in 23 of the 40 patients (58%), and 10 of the patients had severe osteoarthritis (involving at least 2 lumbar vertebral bodies). The serum levels of PICP, ALP, ICTP, and PSA of the patients without osteoarthritis findings were not different from those of the patients with osteoarthritis or severe osteoarthritis.
Conclusion :
The influence of osteoarthritis on serum bone formation and resorption marker levels of patients with BPH appears to be rather slight, if there is any influence at all. 相似文献
The aim of this study was to investigate the influence of osteoarthritis of lumbar vertebrae on serum bone formation and resorption marker levels of patients with benign prostatic hypertrophy (BPH).
Methods :
Serum levels of carboxyterminal propeptide of type I procollagen (PICP), alkaline phosphatase (ALP), carboxyterminaltelopeptide of type I collagen (ICTP), and prostate-specific antigen (PSA) were examined in 40 patients with BPH, and the presence of osteoarthritis at the lumbar vertebrae of the patients was evaluated by plain x-ray-p.
Results :
Findings of osteoarthritis were observed in 23 of the 40 patients (58%), and 10 of the patients had severe osteoarthritis (involving at least 2 lumbar vertebral bodies). The serum levels of PICP, ALP, ICTP, and PSA of the patients without osteoarthritis findings were not different from those of the patients with osteoarthritis or severe osteoarthritis.
Conclusion :
The influence of osteoarthritis on serum bone formation and resorption marker levels of patients with BPH appears to be rather slight, if there is any influence at all. 相似文献
5.
Susumu Akimoto Koichiro Akakura Takemasa Ohki Jun Shimazaki 《International journal of urology》1994,1(3):263-267
To compare levels of y-seminoprotein (gM-Sm) assayed by original and revised assay systems, blood was obtained every 4 h over a 32-h period from 8 untreated prostate cancer patients. Serum levels of prostate specific antigen (PSA) were also examined. In 6 patients, the coefficient of variation (CV) of the serum levels assayed by the revised assay was significantly different from that of the intra-assay samples. In contrast, the CV of the gM-Sm serum levels assayed by the original assay differed significantly from that of the intra-assay samples in only 2 patients. The fluctuations in gM-Sm assayed by the revised assay were, at least in part, similar to those of the PSA serum levels in all patients. The mean CV of the gM-Sm serum levels assayed by the revised assay was significantly larger than that for levels measured by the original assay. After treatment, the rate of decrease in gM-Sm serum levels determined by the original assay differed from that in the serum levels of PSA and prostatic acid phosphatase. These results indicate that the original assay for gM-Sm do not detect diurnal differences in serum gM-Sm levels, even at levels below 20 ng/ml. These observations indicate that the analysis of data obtained using the original gM-Sm kit should be interpreted with caution. 相似文献
6.
7.
Aonuma M Saeki Y Akimoto T Nakayama Y Hattori C Yoshitake Y Nishikawa K Shibuya M Tanaka NG 《International journal of experimental pathology》1999,80(5):271-281
To elucidate the role of vascular endothelial growth factor (VEGF), an endothelial cell-specific mitogen, in tumour angiogenesis and malignant progression, an expression vector harboring human VEGF cDNA was stably transfected into three human cancer cell lines with poor VEGF productivity. Though their in vitro growth rate and intrinsic productivity of another angiogenic factor, basic fibroblast growth factor (bFGF), were not changed by transfection, those clones with higher VEGF production were endowed with tumorigenic and angiogenic potentials as follows: firstly, nontumorigenic, lung carcinoma QG90 cells having lower bFGF productivity acquired tumorigenicity as well as significant in vivo angiogenesis-inducing ability, secondly, tumorigenic colorectal carcinoma RPMI4788 cells having higher potency for bFGF production could form more vascularized solid tumour with faster growth rate and thirdly, oestrogen-dependent breast carcinoma MCF-7 cells, which did not produce detectable bFGF, acquired tumorigenicity even in the absence of oestrogen and the solid tumour growth rate was remarkably enhanced, accompanied with increased vascularization, in the presence of oestrogen. These results suggest that tumour progression closely depends on angiogenesis, and VEGF significantly contributes to malignant progression of a variety of tumour cells through its potent angiogenic activity, independent on the bFGF productivity of tumour cells. 相似文献
8.
Hydatidiform moles associated with multiple gestations after assisted reproduction: diagnosis by analysis of DNA fingerprint 总被引:1,自引:0,他引:1
In spite of the widespread use of assisted reproductive technology, there
have been, to our knowledge, only two reported cases of molar pregnancies
after gamete intra-Fallopian transfer and five reported cases after
in-vitro fertilization and embryo transfer. We report here a case of a
complete hydatidiform mole in a twin pregnancy after gamete intra-Fallopian
transfer, as well as a case of a complete hydatidiform mole in a triplet
pregnancy after in-vitro fertilization and embryo transfer. The genetic
constitution of each conceptus was determined by examination of the
restriction fragment length polymorphism of the DNA with four different
single-locus probes. This analysis revealed that both hydatidiform moles
were of androgenetic origin and probably of monospermic origin. Moreover,
the analysis confirmed that the pregnancies were dizygotic and trizygotic
pregnancies respectively. The diagnostic utility of the analysis of DNA
polymorphism is discussed in cases of a molar pregnancy with coexisting
fetuses.
相似文献
9.
10.
Small pieces of tissue isolated from abdominal sympathetic ganglia in aged male patients were cultured in a chemically defined, serum-free medium. The growth of neurites from pieces of ganglia in cultures with and without 50 ng/ml mouse 2.5S nerve growth factor (NGF) was compared. The NGF stimulated significantly greater regeneration of neurites, causing the growth of long fibers from the ganglion pieces. Many short neurites grew, even in the absence of the NGF, but these were generally short, except for long neurites generated in several nerve cells. A method was devised for the evaluation of NGF-dependent growth of neurites in the culture. The rate of the NGF-dependent growth of neurites, which was calculated by the difference in the total lengths of the NGF-dependent neurites between 2- and 4-day-old cultures, was approximately 160 micron/day. The results indicate that although the growth of neurites from some sympathetic nerve cells of the aged human become independent of the NGF, most of the nerve cells remain dependent on the NGF, even in the stage of senescence. 相似文献