全文获取类型
收费全文 | 4926篇 |
免费 | 398篇 |
国内免费 | 150篇 |
专业分类
耳鼻咽喉 | 170篇 |
儿科学 | 194篇 |
妇产科学 | 103篇 |
基础医学 | 571篇 |
口腔科学 | 87篇 |
临床医学 | 598篇 |
内科学 | 942篇 |
皮肤病学 | 50篇 |
神经病学 | 308篇 |
特种医学 | 535篇 |
外科学 | 610篇 |
综合类 | 135篇 |
一般理论 | 5篇 |
预防医学 | 429篇 |
眼科学 | 56篇 |
药学 | 392篇 |
1篇 | |
中国医学 | 3篇 |
肿瘤学 | 285篇 |
出版年
2021年 | 48篇 |
2020年 | 45篇 |
2019年 | 61篇 |
2018年 | 74篇 |
2017年 | 53篇 |
2016年 | 63篇 |
2015年 | 57篇 |
2014年 | 77篇 |
2013年 | 140篇 |
2012年 | 196篇 |
2011年 | 207篇 |
2010年 | 120篇 |
2009年 | 131篇 |
2008年 | 168篇 |
2007年 | 246篇 |
2006年 | 166篇 |
2005年 | 183篇 |
2004年 | 125篇 |
2003年 | 146篇 |
2002年 | 110篇 |
2001年 | 128篇 |
2000年 | 128篇 |
1999年 | 128篇 |
1998年 | 127篇 |
1997年 | 123篇 |
1996年 | 105篇 |
1995年 | 101篇 |
1994年 | 77篇 |
1993年 | 79篇 |
1992年 | 99篇 |
1991年 | 115篇 |
1990年 | 115篇 |
1989年 | 147篇 |
1988年 | 129篇 |
1987年 | 125篇 |
1986年 | 127篇 |
1985年 | 100篇 |
1984年 | 91篇 |
1983年 | 65篇 |
1982年 | 66篇 |
1981年 | 59篇 |
1980年 | 47篇 |
1979年 | 83篇 |
1978年 | 62篇 |
1977年 | 68篇 |
1976年 | 67篇 |
1975年 | 43篇 |
1974年 | 50篇 |
1973年 | 41篇 |
1968年 | 39篇 |
排序方式: 共有5474条查询结果,搜索用时 15 毫秒
1.
Trends in analgesic self-poisoning in West-Fife, 1971-1985 总被引:1,自引:0,他引:1
J J McMurray D B Northridge V A Abernethy A A Lawson 《The Quarterly journal of medicine》1987,65(246):835-843
All admissions for analgesic self-poisoning to a district poisons unit over a 15-year period have been reviewed. During this time overdose with analgesic drugs increased to represent almost half of all admissions for self-poisoning. The types of analgesics taken in overdose also changed significantly during the period of this review. Aspirin and Distalgesic poisoning declined in incidence and more cases of self-poisoning by paracetamol and non-steroidal anti-inflammatory agents were seen. The impact of these changes on the medical management and outcome of deliberate self-poisoning is analysed. The reasons behind the trends described in this paper are assessed and their implications for future prevention and treatment are discussed. 相似文献
2.
Peter J. Morgan Lynda M. Williams Gary Davidson Wilfred Lawson Edward Howell 《Journal of neuroendocrinology》1989,1(1):1-4
The functional significance of the pars tuberalis (PT) of the mammalian adenohypophysis has remained an enigma (1, 2). One view of its function is that it acts as an auxiliary gland to support the endocrine role of the pars distalis (PD) (2), as it has been shown to contain immunocytochemically identifiable thyrotrophs and gonadotrophs (1). Many of the cells of the PT are, however, ultrastructurally unique suggesting an independent function for this tissue. Our recent demonstration that the PT of the rat is a major binding site for the ligand iodomelatonin lends further support to this idea (3). We have utilized the highly specific ligand [125 l]melatonin, and have demonstrated that it binds exclusively, with very high affinity, to the PT but not the PD of the adult sheep adenohypophysis. These findings support the conclusion that the PT has a distinct role in relation to melatonin action and seasonal reproduction. 相似文献
3.
4.
5.
6.
P J Bernard P M Som M L Urken W Lawson H F Biller 《Otolaryngology--head and neck surgery》1988,99(5):489-493
Although acute thyroiditis often has a distinctive clinical presentation, this relatively uncommon entity can occasionally be confused with other inflammatory processes. In general, the earlier the diagnosis of acute thyroiditis is established, the lower is the frequency and severity of its attendant complications. Computed tomography (CT) is an extremely useful modality in establishing the diagnosis early because it can evaluate iodine content of the thyroid gland and provides more accurate mapping than ultrasound and nuclear medicine techniques. Three patients with acute thyroiditis--two with suppuration--are presented and the CT findings and clinical aspects of this disease are reviewed. 相似文献
7.
8.
Cholecystokinin (CCK) inhibits pancreatic cancer but not hepatic tumor induction by N-nitrosobis (2-oxopropyl) amine (BOP) in hamsters when administered with or shortly before BOP. In this study, we evaluated the capability of sulfated CCK-8 to inhibit DNA alkylation in the hamster pancreas. We examined the pattern of O6-methylguanine (G6-Me) and N7-methylguanine (G7-Me) in pancreatic ductal, acinar and liver tissues from Syrian hamsters treated with a single dose of BOP (20 mg/kg s.c.) and with five s.c. injections of CCK-8 (200 pM/kg, 30 min apart). The first CCK injection was given either 90 min before, or together, or 3 h after POP administration. The amount of G6-Me in liver DNA did not differ significantly. We observed a decrease of G7-Me in the liver of the group treated with CCK together with POP as compared to POP alone (P less than 0.005). Lower amounts of G6-Me were found in ductal preparations (P less than 0.01) of the animals treated with CCK before POP as compared to POP alone. CCK also modified the pattern of alkylation in the acinar tissue, but without a clear relationship with the timing of administration. The results suggest that the inhibitory effect of CCK-8 on pancreatic carcinogenicity of BOP could be related to its capability to modify DNA alkylation by yet unknown mechanisms. 相似文献
9.
S. Gururangan R. A. M. Lawson P. Morris Jones R. F. Stevens R. H. A. Campbell 《Pediatric hematology and oncology》1992,9(2):107-113
The role of open lung biopsy (OLB) in the diagnosis of the etiology of lung infiltrates in children was analyzed for a 10-year period 1979-1989 in a tertiary referral center. A total of 18 children had 19 lung biopsies to ascertain the cause of lung infiltrates. Thirteen of these children (72 %) were immunocompromised due to treatment of hematological/solid malignancies and bone marrow transplantation. The clinical diagnosis was bilateral lung infiltrates of unknown etiology in 17 of 18 children. Eight of these children were ventilated for respiratory failure. The biopsy was useful in achieving a histological diagnosis in 18 of 19 samples (diagnostic yield 95%) and an etiological diagnosis in 14 of 19 samples (etiological yield 74 %). Therapeutic strategy was altered in 14 of 18 patients based on the biopsy results. Five of 14 patients responded favorably to a change in specific treatment. The lime interval from onset of respiratory illness to biopsy was 2-60 days (mean 16 days). Despite the critical state of these children there were few complications associated with the biopsy and no mortality directly related to the procedure. We recommend that OLE be undertaken sooner rather than later in immunocompromised children with bilateral pulmonary infiltrates of unknown etiology. 相似文献
10.
Jerrold S Petrofsky Ernie Schwab Takkin Lo Maria Cuneo Daryl Lawson 《Medical science monitor》2007,13(11):CR498-CR504
BACKGROUND: Wounds, especially in the elderly, can be life threatening. One modality which allegedly increases blood flow (BF) as an aid to heal chronic wounds is electrical stimulation. This technique applies electrical current (ES) across wounds. However, while many studies show positive findings, others do not. The purpose of this investigation was to investigate some of this inconsistency in results by determining the effect of environmental temperature on the circulation of the skin which may negate the effects of electrical stimulation in a clinical setting. MATERIAL/METHODS: Ten people with no wounds, controls (C), and 12 people with wounds (W) were examined in a thermally neutral or cool room (20 degrees C) and a warm room (34 degrees C) to observe the effect of reducing sympathetic vasoconstrictor activity on the response to 5 and 15 mA sine wave biphasic ES delivered by 2x2 cm surface electrodes. RESULTS: C and W subjects showed a greater BF in the skin in a warm room. In group C, after 30 minutes of stimulation at a current of 15 milliamps, BF increased significantly (p<0.05) but by an average of only 4 flux in the cool room. In the warm environment, BF increased significantly (p<0.01) by 19.3+/-7 flux and increased further during the 60 minute recovery phase. In the W group, BF during ES increased much more during stimulation in a warm room compared to a cool room. CONCLUSIONS: The results show that local vasoconstriction due to exposure to a warm global temperature greatly increases the response of the skin the ES. 相似文献