全文获取类型
收费全文 | 16236篇 |
免费 | 854篇 |
国内免费 | 65篇 |
专业分类
耳鼻咽喉 | 164篇 |
儿科学 | 498篇 |
妇产科学 | 311篇 |
基础医学 | 2132篇 |
口腔科学 | 276篇 |
临床医学 | 1312篇 |
内科学 | 4064篇 |
皮肤病学 | 223篇 |
神经病学 | 1888篇 |
特种医学 | 774篇 |
外科学 | 1981篇 |
综合类 | 38篇 |
一般理论 | 3篇 |
预防医学 | 730篇 |
眼科学 | 146篇 |
药学 | 1104篇 |
中国医学 | 31篇 |
肿瘤学 | 1480篇 |
出版年
2023年 | 75篇 |
2022年 | 156篇 |
2021年 | 335篇 |
2020年 | 208篇 |
2019年 | 291篇 |
2018年 | 347篇 |
2017年 | 266篇 |
2016年 | 329篇 |
2015年 | 329篇 |
2014年 | 510篇 |
2013年 | 650篇 |
2012年 | 940篇 |
2011年 | 1005篇 |
2010年 | 564篇 |
2009年 | 513篇 |
2008年 | 873篇 |
2007年 | 902篇 |
2006年 | 821篇 |
2005年 | 803篇 |
2004年 | 746篇 |
2003年 | 689篇 |
2002年 | 672篇 |
2001年 | 423篇 |
2000年 | 429篇 |
1999年 | 448篇 |
1998年 | 198篇 |
1997年 | 133篇 |
1996年 | 124篇 |
1995年 | 117篇 |
1994年 | 104篇 |
1993年 | 96篇 |
1992年 | 288篇 |
1991年 | 267篇 |
1990年 | 281篇 |
1989年 | 261篇 |
1988年 | 195篇 |
1987年 | 173篇 |
1986年 | 191篇 |
1985年 | 218篇 |
1984年 | 132篇 |
1983年 | 104篇 |
1982年 | 82篇 |
1981年 | 52篇 |
1980年 | 50篇 |
1979年 | 112篇 |
1977年 | 58篇 |
1976年 | 56篇 |
1975年 | 53篇 |
1974年 | 55篇 |
1973年 | 60篇 |
排序方式: 共有10000条查询结果,搜索用时 178 毫秒
21.
M. L. Garrè V. Capra E. Di Battista L. Giampietri P. Nozza A. Raso A. Pezzolo A. Rossi C. Milanaccio M. Pavanello A. Naselli 《Child's nervous system》2007,23(2):219-223
Objects Genetic syndromes associated with ependymoma are uncommon, with the exception of NF2. We describe two cases of ependymoma
presenting with Klinefelter’s Syndrome (KS) as co-morbid condition.
Materials and methods The first patient was diagnosed for KS during pregnancy; he also presented a thyroid agenesis and a deficit of methyltetrahydrofolate
reductase (MTHFR); at 30 months of age he was operated on for a grade II ependymoma of IV ventricle; after a multiple-stage
surgery, he underwent oral chemotherapy and stereotactic radiotherapy, but after 15 months he presented a local recurrence
and died. The second patient was diagnosed for KS at the age of 16 months; at 10 years of age, due to back pain, he underwent
an MRI, which showed a cauda equine tumor. He underwent surgery and radiotherapy. Histology was of mixopapillary ependymoma.
Conclusion In a review of literature, various neoplasms have been described in association with KS. To our knowledge, these are the first
two cases reported of ependymoma associated to KS. A retrospective study of 44 monoinstitutional ependymoma cases demonstrated
association with genetic syndromes in 22%. 相似文献
22.
23.
Salvatore Serra Giuliana Brunetti Giovanni Vacca Carla Lobina Mauro A M Carai Gian Luigi Gessa Giancarlo Colombo 《Alcohol》2003,29(2):101-108
Results of a recent study have demonstrated that exposure to multiple ethanol concentrations and repeated ethanol deprivation periods in Indiana ethanol-preferring (P) rats resulted in the development of an alcohol deprivation effect (ADE; the temporary increase in voluntary ethanol intake after a period of deprivation from ethanol) characterized by consumption of intoxicating amounts of ethanol. The current study was designed to possibly extend these results to Sardinian alcohol-preferring (sP) rats, generated with the same selective program previously used for P rats. To this aim, ethanol-naive sP rats were exposed initially to the home cage four-bottle choice [10%, 20%, and 30% (vol./vol.) ethanol solutions and water] for eight consecutive weeks. Subsequently, rats were divided into two groups: The first group had continuous access to the four-bottle regimen (nondeprived rats), and the second group was exposed to five cycles of 14-day periods of deprivation from ethanol and 14-day periods of reexposure to the four-bottle regimen. An ADE developed after each deprivation period. However, the extra intake of ethanol was limited to the first hour of each reaccess period. Magnitude of ADE did not change with repeated periods of deprivation. However, a shift in preference toward the two highest concentrations of ethanol solutions was evident from the first reexposure to ethanol and was maintained throughout the study. These results provide further evidence on the heterogeneity of ethanol-drinking behavior among rat lines selectively bred for high ethanol preference and consumption. 相似文献
24.
Ripamonti C.; De Conno F.; Ventafridda V.; Rossi B.; Baines M. J. 《Annals of oncology》1993,4(1):15-21
Background: Bowel obstruction is a common and distressing outcomein patients with abdominal or pelvic cancer. Patients and methods: Patients may develop bowel obstructionat any time in their clinical history, with an incidence rangingfrom 5.5% to 42% in ovarian carcinoma and from 10% to 28.4%in colorectal cancer. The causes of the obstruction may be benignpostoperative adhesions, a focal malignant or benign deposit,relapse or diffuse carcinomatosis. The symptoms which are almostalways present are intestinal colic (reported in 72%76%of patients), abdominal pain due to distension, hepatomegalyor tumor masses (in 92% of patients) and vomiting (68%100%)of cases. Conclusion: While surgery must remain the primary treatmentfor malignant obstruction, it is now recognised that there isa group of patients with advanced disease or poor general conditionwho are unfit for surgery and require alternative managementto relieve distressing symptoms. A number of treatment optionsare now available for the patient with advanced cancer who developsintestinal obstruction. In this review of the literature, theindications for surgery will be examined, the use of nasogastrictube and percutaneous gastrostomy evaluated and the place ofdrugs for symptom control described. bowel obstruction, advanced and terminal cancer patients 相似文献
25.
P Ninfali L Rossi L Baronciani B Tirillini C Ropars M Magnani 《Alcohol and alcoholism (Oxford, Oxfordshire)》1992,27(1):19-23
Blood levels of acetaldehyde (ACh), ethanol and acetone were investigated in mice treated with ethanol for 6 months and receiving compatible erythrocytes (RBCs) overloaded with aldehyde dehydrogenase (AlDH). Following an acute dose of ethanol, ACh levels were significantly lower in these animals than in alcohol-treated mice receiving AlDH-unloaded RBCs, and were similar to the ACh levels of normal mice. The peak ethanol concentration was higher in normal mice than in both groups of alcohol-treated animals, while acetone concentrations were not significantly different in the three groups of animals. 相似文献
26.
Several types of chronic pain syndromes are effectively treated with sodium channel blockers such as lignocaine. Further investigation of this therapeutic modality would be facilitated by refinement of the parameters describing lignocaine distribution and elimination. This would allow precise lignocaine infusion by a computer-controlled infusion to attain and maintain stable target lignocaine concentrations. Arterial blood samples were obtained at frequent intervals during a computer-controlled infusion of lignocaine in 12 adult human volunteers. Plasma lignocaine concentrations of 1, 2, 3, 4 and 5 microg/ml were targeted for 15 min at each concentration. A three-compartment mammillary pharmacokinetic model best described the resulting concentration vs time profile. A population pharmacokinetic analysis was performed using three different techniques; the two-stage, pooled and mixed effects modelling. There was marked overshoot of the plasma concentration above the target prior to refinement of the pharmacokinetic parameters. The best parameters of a three-compartment mammillary model fit to the measured concentration using the pooled data approach were: V(1) = 7.44, V(2) =11.5 and V(3) = 97.71; Cl(1) = 0.585, Cl(2) = 2.23 and Cl(3) =1.64 l/min. Similarly calculated parameters using NONMEM were V(1) = 6.99, V(2) =12.2 and V(3) =1341; Cl(1) = 0.703, Cl(2) =1.24 and Cl(3) =1.49 l/min. The addition of age as a covariate of the pharmacokinetic parameters improved the model in both cases. Height, lean body mass and body surface area as covariates of the pharmacokinetic parameters did not improve the predicted value of the model. Prospective testing of the pharmacokinetic parameters will be required to define whether they function well. The refinement of pharmacokinetic parameters for the computer-controlled intravenous infusion of lignocaine will facilitate further research in pain therapy. Published lignocaine pharmacokinetic values have a relatively large central volume of distribution, and hence, when implemented as a computer-controlled infusion, result in dramatic overshoot shortly after targeting a higher plasma concentration. In light of the long-lasting pain relief provided by sodium channel blockade in neuropathic pain states, overshoot of plasma concentrations must be avoided if the concentration vs effect relationship is to be defined. 相似文献
27.
28.
29.
Reducing the Occupational Risk of Infections for the Surgeon: Multicentric National Survey on More Than 15,000 Surgical Procedures 总被引:2,自引:0,他引:2
Andrea Pietrabissa Stefano Merigliano Marco Montorsi Gilberto Poggioli Marco Stella Domenico Borzomati Enrico Ciferri Giuseppe Rossi Gianbattista Doglietto 《World journal of surgery》1997,21(6):573-578
The objective of this study was to find the incidence of accidental exposures to blood and body fluids among surgeons during operations and to describe their dynamics. A probabilistic model was also used to predict the cumulative 30-year risk to the surgeon of contracting hepatitis B and C viruses (HBV, HCV) or human immunodeficiency virus (HIV) infection and estimate the effect of preventive strategies in reducing this risk. A multicentric prospective survey, based on self-administered questionnaires, was conducted during a period of 6 months in 39 Italian hospitals. An accidental exposure to blood or body fluids occurred in 9.2% of 15,375 operations. In about 2% of procedures a parenteral-type injury, such as actual skin puncture or eye contamination, was suffered by the operating surgeon. A needle-stick injury was the commonest accident, and its occurrence was found to vary with the phase of the procedure and its length. The current lifetime risk of acquiring HBV, HCV, and HIV infection in our regions was estimated to be as high as 42.7%, 34.8%, and 0.54%, respectively. The adoption of preventive strategies is expected to reduce this risk to 21% for HBV, 16.6% for HCV, and 0.23% for HIV infection. Active immunization of surgeons against HBV is strongly recommended. The case is also made for the use of a face-shield combined with a permanent change in our surgical practice capable of reducing the current high rate of parenteral injuries. 相似文献
30.
Two unrelated children displayed attacks of paroxysmal jerky 'puppet-like' movements lasting 2-3 min. The attacks were not kinesigenic and occurred during wakefulness precipitated by physical exercise and during NREM sleep, spontaneous or upon arousal and awakenings. Paroxysmal dystonic choreoathetosis was excluded by the absent family history, and paroxysmal kinesigenic dystonia by the absence of triggering effects by sudden movements and efficacy of anticonvulsants. Pattern and duration of involuntary movements were not those typical of nocturnal paroxysmal dystonia. Our cases emphasize that overlap exists among the different clinical categories of paroxysmal dyskinesia. 相似文献