全文获取类型
收费全文 | 742篇 |
免费 | 23篇 |
国内免费 | 75篇 |
专业分类
儿科学 | 7篇 |
妇产科学 | 5篇 |
基础医学 | 175篇 |
口腔科学 | 12篇 |
临床医学 | 59篇 |
内科学 | 92篇 |
皮肤病学 | 38篇 |
神经病学 | 145篇 |
特种医学 | 89篇 |
外科学 | 41篇 |
综合类 | 79篇 |
预防医学 | 9篇 |
药学 | 69篇 |
中国医学 | 1篇 |
肿瘤学 | 19篇 |
出版年
2021年 | 3篇 |
2018年 | 8篇 |
2017年 | 6篇 |
2016年 | 9篇 |
2015年 | 2篇 |
2014年 | 4篇 |
2013年 | 17篇 |
2012年 | 15篇 |
2011年 | 18篇 |
2010年 | 25篇 |
2009年 | 23篇 |
2008年 | 31篇 |
2007年 | 73篇 |
2006年 | 57篇 |
2005年 | 59篇 |
2004年 | 29篇 |
2003年 | 34篇 |
2002年 | 20篇 |
2001年 | 30篇 |
2000年 | 27篇 |
1999年 | 22篇 |
1998年 | 34篇 |
1997年 | 24篇 |
1996年 | 28篇 |
1995年 | 20篇 |
1994年 | 12篇 |
1993年 | 22篇 |
1992年 | 10篇 |
1991年 | 9篇 |
1990年 | 4篇 |
1989年 | 19篇 |
1988年 | 7篇 |
1987年 | 13篇 |
1986年 | 16篇 |
1985年 | 19篇 |
1984年 | 7篇 |
1983年 | 14篇 |
1982年 | 9篇 |
1981年 | 13篇 |
1980年 | 6篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1977年 | 6篇 |
1976年 | 5篇 |
1975年 | 6篇 |
1964年 | 3篇 |
1963年 | 2篇 |
1962年 | 2篇 |
1958年 | 2篇 |
1957年 | 3篇 |
排序方式: 共有840条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Background: The fabrication of dental prosthesis requires the transfer of interocclusal records from patient's mouth to semiadjustable articulators using different kinds of recording media. Any inaccuracy in these interocclusal records leads to occlusal errors in the final prosthesis. This study was conducted to evaluate the dimensional changes occurring in the interocclusal recording material over a given period of time and the material's resistance to compression during the cast mounting on the articulator. 相似文献
5.
Gabriele Masi Giulio Perugi Cristina Toni Stefania Millepiedi Maria Mucci Nicoletta Bertini Hagop S Akiskal 《Neuropsychopharmacology》2006,59(7):603-610
BACKGROUND: Recent research has addressed the issue of subtyping juvenile bipolar disorder (JBD). Accordingly, we set out to find out, in a naturalistic sample of bipolar children and adolescents with mania and mixed mania, whether the most useful subtyping should be based on clinical features (elated vs. irritable) or course (episodic vs. chronic). METHODS: We studied 136 patients, 81 male patients (59.6%) and 55 female patients (40.4%), mean age 13.5 +/- 2.9 years, meeting the DSM-IV diagnosis of bipolar disorder, assessed by a structured clinical interview (Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version [K-SADS-PL]). RESULTS: Regarding course, 77 patients (56.6%) had an episodic course and 59 patients (43.4%) had a chronic course. Patients with chronic course were significantly younger, had an earlier onset of JBD, and presented a more frequent comorbidity with disruptive behavior disorders. According to the prevalent mood disturbance, 75 patients (55.1%) showed an elated and 61 patients (44.9%) showed an irritable mood. Elated mood was more frequent in patients with episodic course, whereas irritable mood was more frequent in the patients with chronic course. CONCLUSIONS: These findings suggest that chronic versus episodic course may be a putative differential feature. Further validation of such a distinction would require prospective studies, temperament evaluation, gender and neurobiologic approaches, and differential psychopharmacologic assignment and response. 相似文献
6.
7.
D Marazziti F Ambrogi R Vanacore V Mignani M Savino L Palego G B Cassano H S Akiskal 《Neuropsychobiology》1992,26(1-2):23-26
We investigated subsets of peripheral immunologic cells in 12 drug-free patients affected by major depression according to DSM-III-R criteria, and who had recent evidence of somatic diseases. They were compared with 10 drug-free depressives, with 10 patients with panic disorder, and with 12 healthy volunteers, all without somatic disease. The immune subsets were measured by flow cytometry. The results showed that both groups of depressives had the same abnormalities in immune cells compared with the healthy volunteers or the panic disorder patients; in particular they presented a lower number of CD3+, CD8+ and HLA-DR+. The patients with panic attacks did not differ from healthy controls, except for CD4+ cells which were significantly lowered, even in comparison with the depressive groups. These data, although preliminary and in a small sample, suggest that some immune parameters may be influenced by the presence of a major psychiatric disorder. 相似文献
8.
9.
7β-(6-取代-2-喹诺酮-3-乙酰氨基)头孢菌素的合成 总被引:1,自引:0,他引:1
以6-取代-2-喹诺酮-3-乙酸为侧链,用CDI法和潘化酯法与7-ADCA,7-ACA,7-ACT,和7-ACD缩合,合成了16个新的7β-(6-取代-2-喹诺酮-3-乙酰氨基)头孢菌素类化合物,通过溶媒转提,葡聚糖凝胶(Sephadex LH-20)柱层析及离心薄层层析分离精制,得到纯品。初步体外抑菌试验表明:新化合物对革兰氏阳性及某些阴性菌具有高度敏感性。大多数化合物对所试试验菌的抗菌活性与头孢唑啉和青霉素G钠相当,有些比它们还强。 相似文献
10.