全文获取类型
收费全文 | 86435篇 |
免费 | 8487篇 |
国内免费 | 361篇 |
专业分类
耳鼻咽喉 | 1233篇 |
儿科学 | 2571篇 |
妇产科学 | 1890篇 |
基础医学 | 12111篇 |
口腔科学 | 2043篇 |
临床医学 | 10528篇 |
内科学 | 15009篇 |
皮肤病学 | 1346篇 |
神经病学 | 6830篇 |
特种医学 | 2959篇 |
外国民族医学 | 10篇 |
外科学 | 11747篇 |
综合类 | 2421篇 |
一般理论 | 67篇 |
预防医学 | 9793篇 |
眼科学 | 1895篇 |
药学 | 7179篇 |
9篇 | |
中国医学 | 498篇 |
肿瘤学 | 5144篇 |
出版年
2021年 | 1243篇 |
2020年 | 850篇 |
2019年 | 1175篇 |
2018年 | 1480篇 |
2017年 | 1081篇 |
2016年 | 1166篇 |
2015年 | 1388篇 |
2014年 | 1803篇 |
2013年 | 2766篇 |
2012年 | 3765篇 |
2011年 | 4049篇 |
2010年 | 2217篇 |
2009年 | 2147篇 |
2008年 | 3445篇 |
2007年 | 3784篇 |
2006年 | 3613篇 |
2005年 | 3603篇 |
2004年 | 3340篇 |
2003年 | 3112篇 |
2002年 | 3040篇 |
2001年 | 2777篇 |
2000年 | 2854篇 |
1999年 | 2513篇 |
1998年 | 1094篇 |
1997年 | 903篇 |
1996年 | 887篇 |
1995年 | 811篇 |
1994年 | 823篇 |
1993年 | 763篇 |
1992年 | 2098篇 |
1991年 | 2030篇 |
1990年 | 1900篇 |
1989年 | 1868篇 |
1988年 | 1773篇 |
1987年 | 1783篇 |
1986年 | 1689篇 |
1985年 | 1671篇 |
1984年 | 1393篇 |
1983年 | 1263篇 |
1982年 | 843篇 |
1981年 | 719篇 |
1979年 | 1215篇 |
1978年 | 873篇 |
1977年 | 764篇 |
1976年 | 717篇 |
1975年 | 716篇 |
1974年 | 861篇 |
1973年 | 754篇 |
1972年 | 734篇 |
1971年 | 640篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
The effects of running and meditation on beta-endorphin, corticotropin-releasing hormone and cortisol in plasma, and on mood 总被引:2,自引:0,他引:2
The relations between three hormones of the hypothalamic-pituitary-adrenocortical (HPA) axis, beta-endorphin (β-EP), corticotropin-releasing hormone (CRH) and cortisol, and mood change were examined in 11 elite runners and 12 highly trained meditators matched in age, sex, and personality. Despite metabolic differences between running and meditation, we predicted that mood change after these activities would be similar when associated with similar hormonal change. Compared to pre-test and control values, mood was elevated after both activities but not significantly different between the two groups at post-test. There were significant elevations of β-EP and CRH after running and of CRH after meditation, but no significant differences in CRH increases between groups. CRH was correlated with positive mood changes after running and meditation. Cortisol levels were generally high but erratic in both groups. We conclude that positive affect is associated with plasma CRH immunoreactivity which itself is significantly associated with circulating β-EP supporting a role for CRH in the release of β-EP. Increased CRH immunoreactivity following meditation indicates, however, that physical exercise is not an essential requirement for CRH release. 相似文献
72.
73.
We report the case of a 26-year-old man affected by a symmetrical keratoderma localized to the interdigital spaces of the fingers. No occupational, traumatic, or irritant factors were discovered. Clinical and histological features were consistent with the diagnosis of symmetrical interdigital hyperkeratosis, a sporadic disorder described by Frei in 1926. We believe this condition to be less rare than the few cases reported in the literature would suggest. 相似文献
74.
H. J. Scott G. M. McMullin P. D. Coleridge Smith J. H. Scurr 《Annals of the Royal College of Surgeons of England》1990,72(3):188-192
This review looks at some clinical and experimental methods and treatments used in venous disease, and attempts to dispel some myths which have been associated with it. Over the last century numerous techniques have been introduced to aid the understanding of the physiology of normal legs and the pathophysiology of those with venous disease. Tourniquet testing along with clinical examination remains the only method of venous assessment in most hospitals. Venous ulceration in the past has been associated with deep vein incompetence, but the newer, non-invasive techniques of Doppler ultrasound and duplex examination are now identifying patients with leg ulceration who have superficial venous insufficiency and therefore a surgically correctable condition. Perforating veins and their possible role in the aetiology of venous ulceration along with invasive and non-invasive methods for their detection is reviewed. Some of the conservative compression treatments and dressings available for the treatment of venous ulceration are discussed. It is concluded that adherence to sound surgical principles remains the mainstay of the successful management of patients with venous disease. 相似文献
75.
Z. Janczewski L. Bablok A. Smith M. Czaplicki S. Fr⇂cki 《International urology and nephrology》1990,22(2):161-165
Changes in semen parameters are presented for 4708 patients treated for infertility. The largest group comprised patients
with oligoasthenozoospermia of various grades (57.7%). Improvement in the seminal state was noted in 70.3%. The percentage
of achieved normospermia increased proportionally to the initial semen state. Pregnancy rate also increased proportionally
to the initial seminal state.
Among the patients' wives 20.4% conceived: 28.2% of these pregnancies had occurred after having achieved normospermia, while
in 71.8% the seminal states were still below the accepted normal values. 相似文献
76.
Aspirin (1 mM), a selective cyclooxygenase inhibitor, decreased endplate potential (e.p.p.) amplitude but did not affect either the biphasic changes in m.e.p.p. frequency or triphasic changes in e.p.p. amplitude induced by crotoxin. Nordihydroguaiaretic acid (30 microM), a dual inhibitor of cyclooxygenase and lipoxygenase pathways, increased e.p.p. amplitude but did not affect the characteristic changes in m.e.p.p. frequency and e.p.p. amplitude in response to crotoxin. The incidence of giant m.e.p.p.s was reduced by aspirin and increased by NDGA. Arachidonate metabolism is not a major factor in the induction of neurotoxicity by crotoxin at the frog neuromuscular junction. 相似文献
77.
Ten patients with rheumatoid arthritis (RA) were evaluated in a placebo-controlled, double-blind study examining the clinical efficacy of a novel nonsteroidal anti-inflammatory agent: Tenidap (CP-66,248). RA patients receiving active drug therapy (n = 6) demonstrated clinically significant improvements in observer assessment of pain (p less than 0.025), painful joint count (p less than 0.010), and overall clinical assessment as based on a modified rheumatoid activity index, MRAI (p less than 0.025). In parallel laboratory assays, Tenidap was found to exhibit a significant in vitro dose-dependent inhibition of ionophore-stimulated neutrophil production of the 5-lipoxygenase product: [3H]leukotriene B4 (LTB4). Although more importantly, Tenidap was also found to exhibit an in vitro dose-dependent inhibition (IC50 20 microM) of the ionophore-stimulated release (deacylation) of the precursor [3H]arachidonic acid (AA) from membrane phospholipids. In further studies, Tenidap did not have any effect on fMLP-induced neutrophil chemotactic response. These results suggest that one of the possible mechanisms for the clinical effectiveness of this agent, may be through its effect at inhibiting the release of free AA from membrane phospholipids and therefore limiting its further metabolism into certain biologically-active inflammatory lipids. 相似文献
78.
The talar beak is a well-described secondary sign of talocalcaneal coalition but is not pathognomonic of the condition and may be seen in other causes of restricted or abnormal subtalar motion. We present an unusual complication of talar beaks in two patients who sustained fractures through their beaks. One of the patients described did not have a talocalcaneal coalition but had developed a beak following a compound fracture dislocation of the ankle joint complicated by infection, a previously undescribed predisposing cause. 相似文献
79.
Preventive care for patients following myocardial infarction. The Wessex Research Network (WReN) 总被引:2,自引:1,他引:1
OBJECTIVE: We aimed to assess general practice care for patients following
a myocardial infarction (MI). METHOD: A structured review was carried out
of general practice records of patients identified from hospital
administration data. A total of 266 survivors following MI were identified
from the discharge data of 13 hospitals in Southern England and registered
with 71 GPs belonging to the Wessex Research Network. Median time since
hospital discharge was 2.1 years. The main outcome measures were the
provision of appropriate preventive care, including cardiac rehabilitation,
drug therapy, and lifestyle advice for modifiable risk factors. RESULTS:
Basic care was provided to nearly all patients; 253 (95.1%, 95% Cl
91.8-97.4) had blood pressure documented after their MI, 216 of 234
patients eligible for aspirin (92.3%; 88.1-95.4) had been recommended
treatment, and the provision of advice on smoking cessation was documented
for 27 of 33 continuing smokers (81.8%; 64.5-93.0). However, only 73 of 236
patients eligible to attend a structured rehabilitation programme (30.9%;
25.0-36.8) were documented as having received rehabilitation. Of 89
patients with heart failure following MI, 33 (37.1%; 27.1-48.0) had no
record of having been offered treatment with an ACE inhibitor. Total
cholesterol measurement was documented for only 144 patients (54.1%;
48.1-60.1). We estimate that there is still the potential to prevent
between 4 and 9 deaths in this group of 266 surviving patients in the next
2 years by further improving the quality of follow-up care. CONCLUSIONS:
Preventive care in patients with proven ischaemic heart disease in general
practice remains haphazard, even among doctors enthusiastic to participate
in research and to audit their quality of care. As general practitioners we
should ensure that we are providing high quality preventive care to
patients with clinical disease before we focus on the even more demanding
task of primary prevention.
相似文献
80.
Symptomatic and Clinical Improvement in Morbidly Obese Patients with Gastroesophageal Reflux Disease Following Roux-en-Y Gastric Bypass 总被引:3,自引:0,他引:3
Background: Patients who suffer with gastroesophageal reflux Disease (GERD) endure a worsening of symptoms as their weight
increases. When medical treatment of this condition in the morbidly obese patients fails, surgical intervention may be indicated.
Choosing a procedure which not only helps achieve weight control but which also relieves symptoms and complications of GERD
is the goal. We present a review of patients who have undergone Roux-en-Y Gastric Bypass (RYGBP) and related procedures for
this disease. Methods: One hundred eighty-eight patients undergoing surgery for morbid obesity and for GERD in 1992-1996 were
contacted by mail or phone. All of these patients had undergone preoperative esophagogastroduodenoscopy to grade the severity
of their disease. Their preoperative symptoms were compared to those experienced postoperatively. Results: One hundred thirty
patients underwent a RYGBP with modified Hill fundopexy, 22 patients underwent a distal gastrectomy with modified Hill fundopexy,
8 patients underwent distal gastrectomy alone and 28 patients underwent RYGBP alone. There have been no deaths. There were
nine surgical complications, eight early and one at 2.5 years postoperation. Follow-up is 4-48 months. The average BMI dropped
from 43 to 30.2 kg/m2. Whereas all patients were on some form of medical therapy before surgery, only 14 reported the need for medication postoperatively.
Conclusions: Surgical intervention for weight control and treatment of GERD has been highly successful in our experience both
with respect to weight control and to the reduction of reflux symptoms. Depending upon endoscopic and operative findings a
RYGBP with or without an antireflux procedure can provide dramatic improvement. Gastrectomy with antireflux modifications
is appropriate in selected cases. 相似文献