全文获取类型
收费全文 | 8529篇 |
免费 | 456篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 92篇 |
儿科学 | 288篇 |
妇产科学 | 104篇 |
基础医学 | 1358篇 |
口腔科学 | 123篇 |
临床医学 | 620篇 |
内科学 | 1907篇 |
皮肤病学 | 197篇 |
神经病学 | 887篇 |
特种医学 | 465篇 |
外科学 | 915篇 |
综合类 | 58篇 |
预防医学 | 413篇 |
眼科学 | 172篇 |
药学 | 629篇 |
中国医学 | 14篇 |
肿瘤学 | 783篇 |
出版年
2023年 | 79篇 |
2022年 | 133篇 |
2021年 | 180篇 |
2020年 | 108篇 |
2019年 | 167篇 |
2018年 | 204篇 |
2017年 | 165篇 |
2016年 | 175篇 |
2015年 | 151篇 |
2014年 | 253篇 |
2013年 | 348篇 |
2012年 | 534篇 |
2011年 | 547篇 |
2010年 | 303篇 |
2009年 | 338篇 |
2008年 | 514篇 |
2007年 | 610篇 |
2006年 | 530篇 |
2005年 | 554篇 |
2004年 | 568篇 |
2003年 | 530篇 |
2002年 | 532篇 |
2001年 | 102篇 |
2000年 | 99篇 |
1999年 | 111篇 |
1998年 | 111篇 |
1997年 | 103篇 |
1996年 | 78篇 |
1995年 | 75篇 |
1994年 | 54篇 |
1993年 | 69篇 |
1992年 | 83篇 |
1991年 | 84篇 |
1990年 | 78篇 |
1989年 | 60篇 |
1988年 | 55篇 |
1987年 | 43篇 |
1986年 | 40篇 |
1985年 | 43篇 |
1984年 | 32篇 |
1983年 | 26篇 |
1982年 | 18篇 |
1981年 | 14篇 |
1980年 | 17篇 |
1979年 | 25篇 |
1978年 | 8篇 |
1977年 | 9篇 |
1973年 | 10篇 |
1968年 | 7篇 |
1966年 | 9篇 |
排序方式: 共有9025条查询结果,搜索用时 15 毫秒
21.
A case of a traumatic fistula between the internal carotid artery and the internal jugular vein is reported. The fistula was treated by detachable balloon occlusion and clipping of the internal carotid artery. 相似文献
22.
23.
Keigo Kohara Tomio Ono Keiko Tominaga-Yoshino Tomokazu Shimonaga Seiichi Kawashima Akihiko Ogura 《Brain research》1998,809(2):285
Neurons survive when their activity is maintained. An influential hypothesis on the cellular mechanism underlying this phenomenon is that there is an appropriate range of intracellular Ca2+ concentration ([Ca2+]i) for survival. The rat cerebellar granule neuron in culture serves as the most often used model system for the analysis of activity-dependent survival, since it does not survive unless an excitant (KCl or glutamate) is added to the culture medium. Against the above-mentioned hypothesis, we found in our previous examination no difference between steady-state [Ca2+]i in granule neurons cultured under high KCl (i.e., survival) and low KCl (i.e., death) conditions. In this report, we present the quantitative background of unchanged [Ca2+]i between the two culture conditions. Influx of Ca2+ due predominantly to L-type voltage-dependent calcium channels was higher in high KCl cultures than in low KCl cultures. At the same time, efflux of Ca2+ due to the activity of Ca2+/Na+ antiport was also higher in high KCl cultures. Additionally, we found that the endocytotic activity was greater in high KCl cultures than in low KCl cultures, as monitored by the rate of uptake of horseradish peroxidase added to medium. Since the uptake was blocked by an internal Ca2+ chelator, the increased endocytotic activity in high KCl cultures might be a consequence of the enhanced Ca2+ turnover. 相似文献
24.
Tomoko Yoshinari Yoshikazu Iwasawa Keiko Miura Ikuko S. Takahashi Takahiro Fukuroda Kunio Suzuki Akira Okura 《Cancer chemotherapy and pharmacology》1989,24(6):367-370
Summary BS compounds, a series of new dihydropyridines, successfully overcame multidrug resistance in P388/ADR cells in vitro. These agents synergistically potentiated the cytotoxicity of Adriamycin to P388/ADR cells at a concentration of 1–2 M, whereas they showed hardly any synergistic effect in the parental cell line (P388/S) at the same concentration. They inhibited the active drug efflux in P388/ADR cells as well as the binding of [G-3H]-vinblastine to membrane vesicles from P388/ADR, which was increased in resistant P388 cells as compared with parental cells. Besides, unlike the activity of clinically used calcium antagonists, the calcium antagonistic activity associated with BS compounds was very weak: their arterial relaxation activity was <21% of that of verapamil. These data suggest that BS compounds specifically overcome multidrug resistance without the serious hypotensive side effects that accompany the use of verapamil orother calcium antagonists. 相似文献
25.
Nishioka K Okano M Ichihara Y Ichihara N Nishizaki K 《International archives of allergy and immunology》2005,136(2):142-147
BACKGROUND: Exposure to acute stressors modulates both innate and acquired immune function. However, little is known about whether stress has the potential to modulate the pathogenesis of allergic rhinitis. OBJECTIVES: To determine the effects of acute restraint stress on the initiation of allergic rhinitis in a murine model. METHODS: CBA/J mice were repeatedly intranasally sensitized with phospholipase A2 (PLA2) from honeybee venom without adjuvant. Restraint stress was applied using uniform cylinders once a week for a continuous 8-hour period, on five occasions in total. Production of PLA2-specific antibodies and degree of nasal and blood eosinophilia were compared between stressed and control mice. RESULTS: Repeated intranasal sensitization with PLA2 induced PLA2-specific IgE and marked eosinophilia in both the nose and blood in CBA/J mice. Exposure to restraint stress significantly inhibited production of PLA2-specific IgE, IgG1 and IgG2a. Conversely, the stress exerted no significant effect on eosinophilia. CONCLUSIONS: Exposure to acute restraint stress inhibits antigen-specific antibody production, but not local or systemic eosinophilia. The results of this study suggest that acute stress has the potential to modulate the initiation of allergic rhinitis. 相似文献
26.
Yoshimitsu Fukushima Keiko Wakui Toshiro Nishida Yasuo Ueoka 《American journal of medical genetics. Part A》1991,40(4):485-487
We report on a boy with the blepharophimosis sequence and de novo, apparently balanced reciprocal translocation between 3q23 and 4p15.2 [46, XY,t(3;4)(q23;p15.2)de novo]. Possible assignment of this autosomal dominant disorder is discussed. A 3q23 band is a more preferable gene locus of the blepharophi mosis sequence, based on the comparison of clinical manifestations between 4p- and 3q-syndromes. 相似文献
27.
Toshio Nishimura Keizo Tsuruhara Keiko Naito Junko Hirohara Sotokichi Morii 《Pathology international》1989,39(5):281-288
To examine the effect of colchicine on ethionine induced fatty liver, adult female rats were starved overnight and then injected i.p. with 1 g kg ethionine at 11th hour of fasting; then a half of the rats were also injected i.p. with 2.5 mg kg colchicine twice at 3 and 6 h after the single administration of ethionine. Similarly, fasted control rats were injected i.p. with vehicle alone at the above times. All of the rats were sacrificed after a 20 h fast, and the hepatocytes in periportal areas were observed ultra-structurally. In addition, total lipids in the liver tissue were extracted and determined biochemically. Although similar significant increases of triglyceride were observed in the liver tissue of all ethionine-injected rats, the hapatocytes in the group treated with both chemicals had fewer cytoplasmic fat globules (CFG) than those in the group treated with ethionine only. On the other hand, the diameters of markedly increased membrane-bound lipid particles (MLP) in the double treated group were distributed mainly in the range 0.2–0.4 μm, compared with those (0.1-0.2 μm) in the other groups. These findings indicate that colchicine inhibits the development of CFG in ethionine injured hapatocytes. Acta Pathol Jpn 39: 281∼288, 1989. 相似文献
28.
Glomerular expression of cell-cycle-regulatory proteins in human crescentic glomerulonephritis 总被引:4,自引:0,他引:4
Kosaku Nitta Shigeru Horita Kazuho Honda Keiko Uchida Teruo Watanabe Hiroshi Nihei M. Nagata 《Virchows Archiv : an international journal of pathology》1999,435(4):422-427
To elucidate the mechanism underlying crescentic formation, we assessed the phenotypic characterization and cell-cycle protein expression in human crescentic glomerulonephritis (CRGN). Kidney tissue specimens taken from CRGN patients (10 patients with pauci-immune type rapidly progressive glomerulonephritis (RPGN), 2 patients with Henoch-Schönlein purpura nephritis, and 1 patient with IgA nephropathy) were examined immunohistochemically. Most of the cellular components of the crescents expressed cytokeratin, whereas few cells expressed PHM-5. CD68-positive cells were minor components of cellular crescents, indicating that the major principal cellular component of the crescents is made up of cells with the parietal glomerular epithelial cell (PEC) phenotype. Additionally, serial section analysis revealed that Ki-67-positive cells in the crescents were frequently cyclin-A positive and Bcl-2 positive, but seldom cyclin-B1 positive. Moreover, the expression of cyclin-dependent kinase inhibitor p27Kip1 was low in the cellular crescents, despite being exclusively positive in podocytes within the same section. We concluded that the major component of the cellular crescents is made up of PECs and that apparent expression of cyclins and Bcl-2 and restrained expression of p27Kip1 may be synergistically associated with the development of cellular crescents in human CRGN. 相似文献
29.
Intending to clarify the true Incidence of Invasive lobular carcinoma of the breast In Japanese women as well as the frequency of unilateral multlcentriclty, 362 cases of clinically defined monocentrlc breast cancer without pre-operative biopsy (previously fine needle aspiration or needle biopsy were routinely carried out for every case) were examined by whole mammary gland serial sectioning. On the basis of pathology and the World Health Organization classification of breast tumors, each case was assigned to one of two main histologlc types: Invasive lobular carcinoma (ILC) or Invasive ductal carcinoma (IDC). Invasive lobular carcinoma was further separated into classic and variant types by employing previously published criteria. Twenty-one cases of ILC (5.8%) were diagnosed, which Is more than In most previous Japanese studies. Unilateral multicentric breast carcinoma was detected In 9.5% of ILC and 16.1% of IDC (the difference was found not significant). Microscopically, ILC tumors were found to be, on average, larger than IDC. Patients with classic type ILC tended to be younger than those with variant type or IDC. Estrogen receptor expression was found more frequently In variant type ILC than in classic type. These results suggest that the incidence of invasive lobular carcinoma of the breast In Japanese women is low and that unilateral multicentricity Is not significantly higher in ILC than in IDC. 相似文献
30.
Matsuyama A Yonemitsu N Hayashida S Watanabe K Sugihara H Inokuchi A 《Pathology international》2003,53(1):46-50
Osteosarcoma is one of the neoplasms that may occur following exposure to radiation. A case of osteosarcoma arising in the craniofacial bone with a short latency period of 3 years after radiotherapy for maxillary squamous cell carcinoma is described. A 64-year-old-man underwent right partial maxillectomy and chemoradiotherapy due to squamous cell carcinoma of his right maxillary sinus. Histologically, the tumor was composed of moderately differentiated squamous cell carcinoma with a component of spindle cell carcinoma. Three years later, osteosarcoma developed in the craniofacial bone within the irradiation field of the first tumor. Detailed histological examination demonstrated that there was no component of osteosarcoma in the first tumor or squamous cell carcinoma in the second tumor. Radiation-induced osteosarcoma usually occurs after a long latency period of more than 10 years after the radiotherapy. In this case, osteosarcoma was possibly a radiation-induced osteosarcoma with a short latency period of 3 years. 相似文献