全文获取类型
收费全文 | 21294篇 |
免费 | 958篇 |
国内免费 | 112篇 |
专业分类
耳鼻咽喉 | 152篇 |
儿科学 | 309篇 |
妇产科学 | 204篇 |
基础医学 | 2581篇 |
口腔科学 | 524篇 |
临床医学 | 1310篇 |
内科学 | 4916篇 |
皮肤病学 | 1233篇 |
神经病学 | 2017篇 |
特种医学 | 801篇 |
外科学 | 3584篇 |
综合类 | 141篇 |
预防医学 | 482篇 |
眼科学 | 336篇 |
药学 | 1856篇 |
中国医学 | 62篇 |
肿瘤学 | 1856篇 |
出版年
2023年 | 93篇 |
2022年 | 187篇 |
2021年 | 366篇 |
2020年 | 187篇 |
2019年 | 245篇 |
2018年 | 368篇 |
2017年 | 280篇 |
2016年 | 389篇 |
2015年 | 419篇 |
2014年 | 505篇 |
2013年 | 599篇 |
2012年 | 967篇 |
2011年 | 1051篇 |
2010年 | 625篇 |
2009年 | 516篇 |
2008年 | 951篇 |
2007年 | 1026篇 |
2006年 | 1001篇 |
2005年 | 1037篇 |
2004年 | 1043篇 |
2003年 | 1029篇 |
2002年 | 1015篇 |
2001年 | 647篇 |
2000年 | 711篇 |
1999年 | 689篇 |
1998年 | 337篇 |
1997年 | 247篇 |
1996年 | 240篇 |
1995年 | 197篇 |
1994年 | 182篇 |
1993年 | 165篇 |
1992年 | 481篇 |
1991年 | 431篇 |
1990年 | 421篇 |
1989年 | 442篇 |
1988年 | 413篇 |
1987年 | 389篇 |
1986年 | 331篇 |
1985年 | 299篇 |
1984年 | 190篇 |
1983年 | 162篇 |
1982年 | 96篇 |
1979年 | 173篇 |
1978年 | 99篇 |
1977年 | 94篇 |
1976年 | 78篇 |
1975年 | 79篇 |
1974年 | 80篇 |
1973年 | 85篇 |
1972年 | 88篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Hirofusa Shirai Yoshiaki Inaki Kiichi Takemoto 《Macromolecular chemistry and physics.》1974,175(7):2047-2053
A series of the copper(II) complexes of the type CuL4X2 (L: ligand, X: anion) was prepared with the following substituted imidazoles as ligands 2-ethyl- ( 1a ), 2-ethyl-4-methyl- ( 1b ), 2-phenyl- ( 1c ), 2-undecyl- ( 1d ), and 2-heptadecylimidazole ( 1e ). The structures of these complexes were confirmed by elemental analysis, reflection spectra of the crystals as well as IR-spectroscopy. Polymerization of acrylonitrile was tested in the presence of each imidazole-copper(II) complex in dimethyl sulfoxide solution. 相似文献
82.
83.
A computer program for analysis of chromosome abnormalities 总被引:1,自引:0,他引:1
A computer program was made for the statistical analysis of a large number of abnormal karyotypes and for studies on the relationship between chromosomal abnormalities and clinical features of diseases. The program is based on the disintegration of abnormal karyotypes and the identification of types of abnormalities, chromosome numbers, and breakpoints on chromosomes. The frequencies of abnormalities could be tabulated in a given population according to type, chromosome number, and breakpoints. 相似文献
84.
Murata K Inami M Hasegawa A Kubo S Kimura M Yamashita M Hosokawa H Nagao T Suzuki K Hashimoto K Shinkai H Koseki H Taniguchi M Ziegler SF Nakayama T 《International immunology》2003,15(8):987-992
CD69, known as an early activation marker antigen on T and B cells, is also expressed on platelets and activated neutrophils, suggesting certain roles in inflammatory diseases. In order to address the role of CD69 in the pathogenesis of arthritis, we established CD69-null mice. CD69-null mice displayed a markedly attenuated arthritic inflammatory response when injected with anti-type II collagen antibodies. Cell transfer experiments with neutrophils, but not T cells or spleen cells, from wild-type mice into CD69-null mice restored the induction of arthritis. These results indicate a critical role for CD69 in neutrophil function in arthritis induction during the effector phase. Thus, CD69 would be a possible therapeutic target for arthritis in human patients. 相似文献
85.
BACKGROUND: Chymase is a chymotrypsin-like serine protease primarily stored in mast cells. Infection with helminth parasites is known to increase the level of mast cell chymase in the jejunum and serum in mice. The aim of the present study is to elucidate the role of chymase in helminth infection. METHODS: Chymase inhibitor SUN-C8257 was administered to mice infected with the nematode Nippostrongylus brasiliensis, and the number of eosinophils in the blood, serum IgE levels and fecal egg counts were determined. RESULTS: Administration of SUN-C8257 significantly inhibited blood eosinophilia in BALB/c mice infected with N. brasiliensis. The effect of SUN-C8257 was specific for eosinophils, in that it affected neither the number of total leukocytes nor serum IgE levels. SUN-C8257 did not alter the fecal egg counts in this model, showing that SUN-C8257 has no effect on infectivity and expulsion of the nematode. N. brasiliensis infection induced eosinophilia in mast cell-deficient mice (W/W(v)) as well as their littermates (+/+), and SUN-C8257 inhibited the eosinophilia in +/+ mice but not in W/W(v) mice. These results suggest that the eosinophil number may be regulated by different mechanisms in W/W(v) and +/+ mice, and that the effect of SUN-C8257 on nematode-induced eosinophilia is probably due to chymase inhibition. CONCLUSIONS: Chymase released by activated mast cells may play a role in helminth-induced eosinophilia. 相似文献
86.
87.
Immunohistochemical analysis of MCT1, MCT2 and MCT4 expression in rat plantaris muscle 总被引:3,自引:1,他引:3
Takeshi Hashimoto Shinya Masuda Sadayoshi Taguchi George A. Brooks 《The Journal of physiology》2005,567(1):121-129
All three forms of recombinant low voltage-activated T-type Ca2 + channels (Cav 3.1, Cav 3.2 and Cav 3.3) exhibit a small, though clearly evident, window T-type Ca2 + current ( I Twindow ) which is also present in native channels from different neuronal types. In thalamocortical (TC) and nucleus reticularis thalami (NRT) neurones, and possibly in neocortical cells, an I Twindow -mediated bistability is the key cellular mechanism underlying the expression of the slow (< 1 Hz) sleep oscillation, one of the fundamental EEG rhythms of non-REM sleep. As the I Twindow -mediated bistability may also represent one of the cellular mechanisms underlying the expression of high frequency burst firing in awake conditions, I Twindow is of critical importance in neuronal population dynamics associated with different behavioural states. 相似文献
88.
Okamoto T Hashimoto M Samejima H Mori A Wakabayashi M Takeda A Nakamura H Naruse H Bouike Y Araki N 《Immunopharmacology and immunotoxicology》2004,26(4):645-652
Immediate hemolytic transfusion reactions (IHTR) occurred in the course of delayed hemolytic transfusion reactions (DHTR). An 84-year-old man had received a blood transfusion 20 years ago. Progressive anemia developed, because of continuous bleeding from a bladder tumor. He was transfused with concentrated red blood cells (CRC) which were Rh-E antigen negative, because he had anti-E antibodies (day 0). He received CRC on day 3, and underwent resection of bladder tumor on day 6. Although crossmatch-compatible CRCs were prepared for the operation, those were not required and were kept in a refrigerator in the ward. On day 9, when a CRC kept in the ward was transfused, he suddenly had a IHTR. In order to analyze a mechanism of IHTR, the anti-Jk(b) and anti-Di(b) antibodies, anti-HLA antibodies and the concentrations of inflammatory cytokines were measured in serum samples. The anti-Jk(b) and anti-Di(b) antibodies increased prior to IHTR experienced on day 9. The concentrations of IL-6 and IL-1beta increased from day 2, while the concentration of IL-8 increased from day 7. The anti-HLA class I antibody could be detected 2 days before IHTR. Thus, the anti-Jk(b) and anti-Di(b) antibodies induced the production of inflammatory cytokines and symptoms of DHTR and IHTR. The anti-HLA class I antibody could be produced in spite of using the filer for removing leukocytes, and may take part in the induction of IHTR. Further, blood products should be transfused soon after completing a crossmatch test in patients with anti-RBC alloantibodies. 相似文献
89.
Kawashita M Shineha R Kim HM Kokubo T Inoue Y Araki N Nagata Y Hiraoka M Sawada Y 《Biomaterials》2003,24(17):2955-2963
Radiotherapy is one of the most effective treatments for cancers. However, external irradiation provides only small doses to deep-seated cancers, and often causes damage to healthy tissues. It has been reported that 20-30 microm diameter 17Y(2)O(3)-19Al(2)O(3)-64SiO(2) (mol%) glass microspheres are useful for the in situ irradiation of cancers. Yttrium-89 (89Y) in this glass can be neutron bombarded to form the beta-emitter 90Y (half-life=64.1h). When injected in the vicinity of the cancer, such activated glass microspheres can provide a large localized dose of beta-radiation. The Y(2)O(3) content of the glass in the microspheres is limited to only 17 mol%. Chemically durable microspheres with a higher Y(2)O(3) content need to be developed. Phosphorus-31 (31P) with 100% natural abundance can also be activated by neutron bombardment to form the beta-emitter 32P (half-life=14.3d). Chemically durable microspheres containing a high phosphorus content are expected to be more effective for cancer treatment. We prepared pure Y(2)O(3) and YPO(4) microspheres using a high-frequency induction thermal plasma melting technique, and investigated the resulting structure and chemical durability. We successfully prepared smooth, highly spherical polycrystalline Y(2)O(3) and YPO(4) microspheres with diameters in the range 20-30 microm. Both the Y(2)O(3) and YPO(4) microspheres showed high chemical durability in saline solutions buffered at pH=6 and 7. These microspheres are expected to be more effective than the conventional glass microspheres for the in situ radiotherapy of cancer. 相似文献
90.
Y. Hamamoto K. Kinoshita K. Hashimoto T. Matsushita K. Kogishi K. Yasuhira 《International journal of experimental pathology》1983,64(2):177-184
Pulmonary granulomas induced in rabbits by the endobronchial instillation of mycobacterial chemical fractions were re-examined for eosinophilic infiltration. Delayed type hypersensitivity reactions either of tuberculin type or of wax D type did not induce but rather suppressed eosinophilic infiltration in the inflamed area, although some peptidoglycans which are antigenic for the induction of immediate hypersensitivity and fatty acid fractions were weak stimulators of eosinophilic infiltration. Bacterial endotoxin, LPS, was a potent stimulator. It was found that some long chain fatty acids can cause severe eosinophilic infiltration in the induced granulomas. Arachidonic acid was the most active of those examined, so the activity of its metabolites was tested and PGE2 was found to be most active. As the eosinophilic infiltration was markedly suppressed in animals treated with a cyclooxygenase inhibitor (aspirin), the stimulators of eosinophilic infiltration were not fatty acids themselves but their metabolites, PGE2 and some others. The site of permeation of eosinophils from the circulation was found to be arteriolar in the inflamed lung. The granulomatous lesion with eosinophilic infiltration in rabbits is discussed to shed light on the aetiology of eosinophilic granuloma in the human lung. 相似文献