全文获取类型
收费全文 | 61383篇 |
免费 | 3967篇 |
国内免费 | 119篇 |
专业分类
耳鼻咽喉 | 558篇 |
儿科学 | 2576篇 |
妇产科学 | 1681篇 |
基础医学 | 7705篇 |
口腔科学 | 658篇 |
临床医学 | 8949篇 |
内科学 | 10705篇 |
皮肤病学 | 904篇 |
神经病学 | 6331篇 |
特种医学 | 1289篇 |
外国民族医学 | 2篇 |
外科学 | 5092篇 |
综合类 | 727篇 |
一般理论 | 109篇 |
预防医学 | 8433篇 |
眼科学 | 806篇 |
药学 | 3945篇 |
中国医学 | 61篇 |
肿瘤学 | 4938篇 |
出版年
2023年 | 326篇 |
2022年 | 452篇 |
2021年 | 1082篇 |
2020年 | 752篇 |
2019年 | 1119篇 |
2018年 | 1282篇 |
2017年 | 1037篇 |
2016年 | 1126篇 |
2015年 | 1327篇 |
2014年 | 1817篇 |
2013年 | 2890篇 |
2012年 | 4212篇 |
2011年 | 4496篇 |
2010年 | 2509篇 |
2009年 | 2246篇 |
2008年 | 4082篇 |
2007年 | 4350篇 |
2006年 | 4163篇 |
2005年 | 4299篇 |
2004年 | 4100篇 |
2003年 | 3857篇 |
2002年 | 3558篇 |
2001年 | 648篇 |
2000年 | 507篇 |
1999年 | 617篇 |
1998年 | 747篇 |
1997年 | 659篇 |
1996年 | 524篇 |
1995年 | 530篇 |
1994年 | 458篇 |
1993年 | 394篇 |
1992年 | 403篇 |
1991年 | 346篇 |
1990年 | 317篇 |
1989年 | 340篇 |
1988年 | 330篇 |
1987年 | 299篇 |
1986年 | 277篇 |
1985年 | 272篇 |
1984年 | 289篇 |
1983年 | 249篇 |
1982年 | 269篇 |
1981年 | 258篇 |
1980年 | 204篇 |
1979年 | 182篇 |
1978年 | 156篇 |
1977年 | 120篇 |
1976年 | 100篇 |
1974年 | 132篇 |
1973年 | 106篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
E M Boyczuk W Synan J Berger B D Gold 《Oral surgery, oral medicine, and oral pathology》1987,64(5):539-540
A case of dislodgement of a submandibular sialolith into the oropharynx during nasal intubation is presented. The deleterious effect of the patient aspirating the stone into the lungs was averted by the taking of a lateral skull radiograph and localization and removal of the sialolith. 相似文献
82.
J A Cocores M D Patel M S Gold A C Pottash 《The Journal of nervous and mental disease》1987,175(7):431-432
Cocaine is a potent dopamine agonist that frequently stimulates the central nervous system and is often manifested by increased psychomotor activity, impulsivity, euphoria, and rapid thoughts. Attention deficit disorder (ADD) and bipolar disorder also present with physical restlessness, racing thoughts, distractibility, and mood instability. Although these three disorders rarely appear in the same individual, they are important differential diagnoses when considering any one illness with the above symptom complexes. We report two cases of cocaine abuse with ADD residual type in patients who were previously diagnosed as having atypical bipolar disorder. The adverse effects were reversed by the dopamine agonist bromocriptine. 相似文献
83.
Deacon E. Harle Keri Davies Rakhee Shah Syma Hussain Susan Cowling Tejinder K. Panesar Jonathan Bourton Bruce J. W. Evans 《Ophthalmic & physiological optics》2007,27(1):100-105
Despite the current popularity of binocular indirect ophthalmoscopy, direct ophthalmoscopes are still commonly used by clinicians for fundus examination. They are considered to be expensive, however, and it has been suggested that this cost can prevent their use by healthcare professionals in developing countries. The Optyse Lens Free Ophthalmoscope is a novel direct ophthalmoscope, without a lens focus system, that allows for comparatively inexpensive manufacture and supply. We compared the clarity of view with the Optyse to that with standard direct ophthalmoscopes, over a sequential cohort of patients with a variety of refractive errors and ocular conditions. The grade of clarity of view with the Optyse Lens Free Ophthalmoscope was less than conventional ophthalmoscopes (Wilcoxon signed rank test, p < 0.0001). This grade of clarity of view was not associated with the ametropia of the ophthalmoscopic observation (Spearman r < or = 0.03, p > or = 0.28) but was with the presence of cataracts (chi2 test, p < 0.0001) with both the Optyse and the conventional ophthalmoscopes. Despite its limitations, the retinal view with Optyse was often within acceptable clinical limits suggesting that this relatively inexpensive ophthalmoscope may have a place when cost prohibits any other type of ophthalmoscope use. 相似文献
84.
85.
86.
Hodgkin's disease (HD) was diagnosed in 24 patients who were either seropositive for human immunodeficiency virus (HIV) (21) or members of a high-risk group (three), but had not developed acquired immune deficiency syndrome (AIDS). Clinical presentation of the disease was characterized by constitutional symptoms in all, especially fever (23/24) and disseminated disease (22/24) at diagnosis. Mediastinal adenopathy was rare. Bone marrow involvement was particularly frequent (12/24), and a positive bone marrow biopsy preceded lymph node biopsy in 5 of the 12. Histopathologic features of these tumors included an increased number of nonlymphoid stromal cells, i.e., histiocytic and/or fibroblastoid. In some tumors these fibrohistiocytoid stromal cells were arranged in bundles, but distinct nodule with birefringent collagen band formation was not observed. Twenty-two patients were treated, most with combination chemotherapy; one was untreated; one, unknown. Sixteen, including the one untreated, died with disease at 3 to 25 months; one died of an unrelated cause; four were alive at 3 to 24 months; three were lost to follow-up. Frequent bone marrow involvement at presentation suggests the usefulness of the bone marrow biopsy for diagnosis in subjects at risk, especially when they present with spiking fever of unknown origin. Contrary to most previous series, virtually all of our cases were of mixed cellularity type, characterized by increased fibrohistiocytoid stromal cells in place of depleting lymphocytes. The classic nodular sclerosing feature with birefringent collagen band formation was not observed. In conclusion, HIV-associated HD was characterized by advanced stage with fever at presentation, preponderance of mixed cellularity histologic type with increased fibrohistiocytoid stromal cells, and poor outcome. Hodgkin's disease in AIDS patients presents an intriguing biological model to study the role of stromal histiocytes in immunodeficient patients. 相似文献
87.
Intakes and major dietary sources of cholesterol and phytosterols in the British diet 总被引:2,自引:0,他引:2
Gillian M. Morton Susan M. Lee David H. Buss Paul Lawrance 《Journal of human nutrition and dietetics》1995,8(6):429-440
Cholesterol intakes in Britain have been re-estimated by analysing Total Diet samples taken in 1991 and from 1993 National Food Survey records. The Total Diet samples contained only 284 mg/day compared with 319 mg/day in 1987 and 337 mg/day in 1981, while the National Food Survey showed intakes had fallen to 238 mg/day from 259 mg/day in 1990 and 405 mg/day in 1970-75. More details of the intakes by adults in 1986/87 are given, and compared with the results from the other methods. Daily intakes of eight phytosterols were also estimated, the main ones being β-sitosterol, campesterol, stigmasterol and 57-stigmastenol whose intakes were 104, 49, 10 and 4 mg/day, respectively, in 1991. These intakes had increased since 1981, reflecting the rising consumption of vegetable oils. 相似文献
88.
89.
90.
Susan A. Murphy Gillian R. Bentley Mary Ann O'Hanesian 《Statistics in medicine》1995,14(17):1843-1857
This paper concerns the analysis of menstrual data; in particular, methodology to identify variables that contribute to the variability of menstrual cycles both within and between women. The basis for the proposed methodology is a parameterization of the mean length of a menstrual cycle conditional upon the past cycles and covariates. This approach accommodates the length-bias and censoring commonly found in menstrual data. Data from a longitudinal study of menstrual patterns and other variables among Lese women of the Ituri Forest, Zaire, illustrate the methodology. A small simulation illustrates the bias caused by incorrectly deleting the censored cycles. 相似文献