全文获取类型
收费全文 | 1390785篇 |
免费 | 116410篇 |
国内免费 | 6486篇 |
专业分类
耳鼻咽喉 | 17341篇 |
儿科学 | 44380篇 |
妇产科学 | 37555篇 |
基础医学 | 190549篇 |
口腔科学 | 37252篇 |
临床医学 | 125956篇 |
内科学 | 288766篇 |
皮肤病学 | 32527篇 |
神经病学 | 115515篇 |
特种医学 | 57212篇 |
外国民族医学 | 278篇 |
外科学 | 218748篇 |
综合类 | 32408篇 |
现状与发展 | 3篇 |
一般理论 | 483篇 |
预防医学 | 111565篇 |
眼科学 | 29175篇 |
药学 | 97013篇 |
5篇 | |
中国医学 | 2299篇 |
肿瘤学 | 74651篇 |
出版年
2018年 | 14406篇 |
2017年 | 11375篇 |
2016年 | 13621篇 |
2015年 | 15238篇 |
2014年 | 21437篇 |
2013年 | 31989篇 |
2012年 | 39395篇 |
2011年 | 42343篇 |
2010年 | 26344篇 |
2009年 | 25716篇 |
2008年 | 39565篇 |
2007年 | 42117篇 |
2006年 | 43157篇 |
2005年 | 41845篇 |
2004年 | 40061篇 |
2003年 | 38859篇 |
2002年 | 36784篇 |
2001年 | 66544篇 |
2000年 | 68316篇 |
1999年 | 57130篇 |
1998年 | 17382篇 |
1997年 | 15550篇 |
1996年 | 16514篇 |
1995年 | 16677篇 |
1994年 | 15510篇 |
1993年 | 14538篇 |
1992年 | 47426篇 |
1991年 | 46083篇 |
1990年 | 44256篇 |
1989年 | 42116篇 |
1988年 | 39037篇 |
1987年 | 38378篇 |
1986年 | 36097篇 |
1985年 | 34917篇 |
1984年 | 26776篇 |
1983年 | 22454篇 |
1982年 | 14307篇 |
1981年 | 12889篇 |
1980年 | 12129篇 |
1979年 | 23784篇 |
1978年 | 17351篇 |
1977年 | 14643篇 |
1976年 | 13382篇 |
1975年 | 13931篇 |
1974年 | 16331篇 |
1973年 | 15575篇 |
1972年 | 14333篇 |
1971年 | 13187篇 |
1970年 | 12003篇 |
1969年 | 11210篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
M Campbell-Brown I R McFadyen D V Seal M L Stephenson 《British medical journal (Clinical research ed.)》1987,294(6587):1579-1582
A total of 4470 pregnant women were screened for bacteriuria by the dipslide method and significant growth found in 226 (5.1%). In 198 cases the urine was re-examined, in 119 by using suprapubic aspiration or catheterisation (62 (52%) samples contained bacteria) and in 79 by using midstream urine samples (26 (33%) samples contained greater than 10(8) colony forming units/1), showing the maximum prevalence of confirmed bacteriuria to be 2.6%. Overt urinary tract infection developed later in four of 80 patients with proved bacteriuria who had been given antibiotics, in one of eight untreated patients with bacteriuria, in one of 110 patients with unconfirmed bacteriuria, and in one of 226 non-bacteriuric controls. A history of urinary tract infection was given by 18% of controls and 42% of women with confirmed bacteriuria. Screening for bacteriuria and treatment with antibiotics to prevent later overt infection is expensive. Whether it is worth while and cost effective depends largely on the prevalence of bacteriuria in the local population and the proportion who develop overt infection. The screening and treatment programme reported here appeared to prevent only six cases of overt infection. 相似文献
992.
The urinary cyclic AMP response to bovine parathyroid hormone and urinary concentrating ability (max Uosm) after des-amino-D -arginine vasopressin were studies in nine volunteers and seven patients receiving long-term neuroleptic treatment. Max Uosm was lower in the patient group (770 ± 70 mosmol/kg) compared with the controls (948 ± 152 mosmol/kg) but the trend to a lower cAMP response to bovine PTH was not statistically significant. These results suggest that, although adenylate cyclase inhibition may contribute, other mechanisms are also important in the genesis of reduced uring concentrating ability in patients treated with psychotropic drugs. 相似文献
993.
A procedure is reported by which high levels of the tricyclic molecule desipramine was modified and conjugated at high density to the carrier molecules keyhole limpet hemocyanin and bovine serum albumin so that these could be used as immunogens in Balb/c mice. Such conjugates generated immune responses with high levels of antibody with specificity for the tricyclic. B cell hybridomas generated by fusion of immune Balb/c splenocytes to NS-1 cells which secreted monoclonal antibodies with specificity for the tricyclic were selected in a standard ELISA. In this report, we show that the binding constants of these monoclonal antibodies with various haptens can be assessed accurately by measuring fluorescence polarization, that a high degree of cross-reactivity between the monoclonals and various tricyclics exists, and that this procedure can be used to generate monoclonal antibodies of high binding constants. 相似文献
994.
M Beppu J F Codington R D Lasky R W Jeanloz 《Journal of the National Cancer Institute》1987,78(6):1169-1175
Fetal tissues from time-pregnant female A/J mice of 16- and 19-day pregnancies and from neonates 1 day after birth, as well as from fetal cells in culture, absorbed significant amounts of anti-epiglycanin antibody. Detergent-solubilized glycoproteins, with epiglycanin activity, from fetal tissues and cells were separated by polyacrylamide gel electrophoresis, and the protein bands electroblotted onto a nitrocellulose gel. After the antigens were labeled with rabbit anti-epiglycanin antiserum and [125I]epiglycanin, autoradiography revealed two major bands containing the antigenic determinant at Mr 90,000 and 82,000. Bands of similar molecular weights, but with no demonstrated immunologic cross-reactivity, were observed by fluorography, if intact cells prior to solubilization were labeled by galactose oxidase followed by sodium borotritiide. Immunoreactive epiglycanin activity could be destroyed by Pronase, endo-N-acetyl-alpha-D-galactosaminidase (Diplococcus pneumoniae), or periodate oxidation. Activity was enhanced with neuraminidase. The spleen, liver, or erythrocytes from adult A/J mice did not possess the antigen, but incubation of adult spleen or liver with neuraminidase (Vibrio cholerae) exposed the epitope. 相似文献
995.
In contrast to the systolic blood pressure at the posterior tibial artery, the evaluation of pressure at the digital artery of the foot before and after exercise in patients with peripheral arterial disease is not well known. Twenty three patients with peripheral vascular disease were examined. The systolic pressure was measured by means of an ultrasound velocity detector at the brachial and posterior tibial artery. Digital artery pressure was determined with photoplethysmography. Pressures were measured before and within 5 and 10 minutes after a treadmill test. Ankle and toe index was calculated. At rest the toe index is lower than the ankle index and after a treadmill test the decrease in toe index occurs in parallel to the ankle index. 相似文献
996.
Functional renal insufficiency during long-term therapy with captopril and enalapril in severe chronic heart failure 总被引:4,自引:0,他引:4
Renal function was evaluated in 104 patients with severe chronic heart failure whom we treated with captopril or enalapril. Seventy patients showed no change or an improvement in renal function (group A), and 34 patients developed functional renal insufficiency (group B). Before converting-enzyme inhibition, group B patients received higher doses of furosemide (p less than 0.02) and had lower central venous pressures (p less than 0.05) than group A patients. After 1 to 3 months of converting-enzyme inhibition, an excessive reduction in left ventricular filling pressure (to less than 15 mm Hg) or mean arterial pressure (to less than 60 mm Hg) was noted in 28 of 34 (82%) patients in group B but in only 22 of 70 patients in group A (31%) (p less than 0.001). At the end of the study, drug-induced azotemia resolved after a reduction in the dosage of diuretics, despite unaltered treatment with captopril and enalapril. Hence, the deterioration of renal function after converting-enzyme inhibition in heart failure is not a toxic or immunologic reaction to therapy but results from specific hemodynamic events that can be ameliorated by sodium repletion. 相似文献
997.
998.
M L Cibull M E Thompson L Smith C D Jennings M A Doukas E J Pavlik D E Powell 《American journal of hematology》1987,24(3):293-299
The emergence of a near-haploid clone of cells in blast phase chronic myelogenous leukemia is an unusual event. We report such a case and review eight other cases described in the English literature. The significance of the substantial loss of genetic material is discussed as is the phenotypic and genotypic heterogeneity observed in this group of patients. 相似文献
999.
Psychotropic prescribing patterns of nonpsychiatric residents in a general hospital in 1973 and 1982
The findings of a study of the frequency and type of psychotropic drugs that nonpsychiatric residents prescribed for nonpsychiatric patients in a teaching hospital in 1982 were compared with the findings of a similar study in the same hospital nine years earlier. The overall percentage of patients receiving psychotropic drugs remained almost the same, at less than 10 percent. However, in 1982 residents prescribed antidepressants almost four times as often as in 1973, and the use of antianxiety agents decreased. Deficiencies in chart documentation of psychotropic prescribing and the tendency to use conservative dosages remained unchanged from the earlier study. 相似文献
1000.