全文获取类型
收费全文 | 20394篇 |
免费 | 1532篇 |
国内免费 | 54篇 |
专业分类
耳鼻咽喉 | 238篇 |
儿科学 | 686篇 |
妇产科学 | 390篇 |
基础医学 | 3121篇 |
口腔科学 | 325篇 |
临床医学 | 2073篇 |
内科学 | 4525篇 |
皮肤病学 | 283篇 |
神经病学 | 2292篇 |
特种医学 | 728篇 |
外国民族医学 | 3篇 |
外科学 | 2652篇 |
综合类 | 207篇 |
一般理论 | 7篇 |
预防医学 | 1233篇 |
眼科学 | 693篇 |
药学 | 996篇 |
中国医学 | 14篇 |
肿瘤学 | 1514篇 |
出版年
2021年 | 254篇 |
2020年 | 173篇 |
2019年 | 284篇 |
2018年 | 349篇 |
2017年 | 271篇 |
2016年 | 354篇 |
2015年 | 352篇 |
2014年 | 439篇 |
2013年 | 637篇 |
2012年 | 991篇 |
2011年 | 1059篇 |
2010年 | 623篇 |
2009年 | 561篇 |
2008年 | 870篇 |
2007年 | 1026篇 |
2006年 | 969篇 |
2005年 | 923篇 |
2004年 | 928篇 |
2003年 | 812篇 |
2002年 | 822篇 |
2001年 | 635篇 |
2000年 | 615篇 |
1999年 | 499篇 |
1998年 | 210篇 |
1997年 | 190篇 |
1996年 | 153篇 |
1995年 | 174篇 |
1994年 | 146篇 |
1993年 | 148篇 |
1992年 | 438篇 |
1991年 | 411篇 |
1990年 | 406篇 |
1989年 | 363篇 |
1988年 | 350篇 |
1987年 | 339篇 |
1986年 | 352篇 |
1985年 | 312篇 |
1984年 | 267篇 |
1983年 | 229篇 |
1982年 | 164篇 |
1981年 | 162篇 |
1980年 | 136篇 |
1979年 | 222篇 |
1978年 | 201篇 |
1977年 | 139篇 |
1976年 | 142篇 |
1975年 | 140篇 |
1974年 | 171篇 |
1973年 | 163篇 |
1972年 | 133篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
E D Barnett J O Klein S I Pelton L M Luginbuhl 《The Pediatric infectious disease journal》1992,11(5):360-364
Acute otitis media (AOM) is thought to occur frequently in children infected with human immunodeficiency virus (HIV). We compared experience with AOM of 28 HIV-infected children with that of 33 children who seroreverted to HIV antibody negative status by age 18 months. The mean number of episodes/year of AOM for children who seroreverted decreased from 1.33 in the first year of life to 0.13 in the third year, whereas the mean number of episodes/year in HIV-infected children increased from 1.89 to 2.40. By age 3 years, all HIV-infected children had experienced 1 or more episodes of AOM, and 80% had experienced 6 or more, whereas 75% of children who seroreverted had experienced 1 or more episodes, and none had had 6 or more. HIV-infected children with normal T4 lymphocyte counts had a mean of 1.18 episodes of AOM in the first year of life compared with 2.35 episodes in HIV-infected children with decreased counts (P = 0.023). HIV-infected children with low counts had a nearly 3-fold increased risk of recurrent AOM (47% vs. 18%). 相似文献
52.
We treated 6 grade III acromioclavicular injuries with a new fixation method using a bone-ligament transfer of the coracoacromial ligament into a clavicular tunnel. After an average of 16 months, function and cosmesis were excellent in all patients. 相似文献
53.
The effect of cyclophosphamide pulses on fertility in patients with lupus nephritis. 总被引:2,自引:0,他引:2
P Langevitz L Klein M Pras A Many 《American journal of reproductive immunology (New York, N.Y. : 1989)》1992,28(3-4):157-158
The effect of cyclophosphamide pulse therapy given in relatively small doses (10 mg/kg per pulse) in 17 females with lupus nephritis has been studied. Four females developed menopause; in one transient amenorrhea occurred. No changes in menstrual cycle were noted in the other 11 females, four of whom subsequently delivered five normal babies. These data suggest the relative safety of small doses of cyclophosphamide pulse therapy on gonadal function in females under age 40 years. 相似文献
54.
55.
56.
Antibodies against neutrophils have been detected in sera from patients with primary sclerosing cholangitis and inflammatory bowel diseases either by immunofluorescence or by enzyme-linked immunosorbent assay. To assess primary sclerosing cholangitis-specific antibodies, we examined sera from 30 patients with clinically and morphologically well-established primary sclerosing cholangitis by Western blotting against neutrophils and compared these results with those obtained by testing sera from patients with inflammatory bowel diseases. By Western blot using sonified neutrophils, 24 (80%) of 30 primary sclerosing cholangitis sera were positive. Five antigenic determinants at 95, 60, 55, 40 and 30 kD were visualized. Twenty-eight of the primary sclerosing cholangitis sera also showed the characteristic perinuclear fluorescence pattern by immunofluorescence on neutrophils. Thus a serological diagnosis of primary sclerosing cholangitis could be made in 80% of patients based on these two methods. In contrast, only 9% of 23 patients with ulcerative colitis and 10% of 60 patients with Crohn's disease were positive by Western blot, and these patients also showed positive perinuclear fluorescence pattern by immunofluorescence, suggesting an overlap between inflammatory bowel diseases and primary sclerosing cholangitis. Although some patients with classical primary biliary cirrhosis and autoimmune chronic active hepatitis had antibodies against primary sclerosing cholangitis epitopes, none of the patients with obstructive bile duct disorders, collagen diseases, Wegener's granulomatosis or other hepatic and nonhepatic disorders were positive by Western blot, indicating the specificity of these five primary sclerosing cholangitis-related neutrophilic epitopes. 相似文献
57.
R A Coates V T Farewell J Raboud S E Read M Klein D K MacFadden L M Calzavara J K Johnson M M Fanning F A Shepherd 《Journal of clinical epidemiology》1992,45(3):245-253
The Toronto Sexual Contact Study comprises a cohort of 249 male sexual contacts of men with HIV disease which has been followed every 3 months for almost 5 years. On enrollment 143 were seropositive and 16 seroconverted during the follow-up period. By 31 December 1989, 41 of the 159 seropositive cohort members had developed AIDS. Using Cox relative risk regression models, we investigated the association of a number of laboratory and clinical variables and progression to AIDS. Fixed covariate models examined laboratory variables from the enrollment visit of cohort members, with time calculated from this date. In models assessing time dependent covariates, time was calculated from the estimated date of HIV infection. In the univariate models of either fixed or time dependent covariates, many variables were significantly associated with risk of progression to AIDS (T4 cell count, T4/T8 ratio, blastogenic responses to phytohemagglutinin, concanavalin A, and pokeweed mitogen, serum IgA, appearance of p24 antigen, and the development of oral hairy leukoplakia, thrush, or herpes zoster). Appearance of persistent generalized lymphadenopathy was not associated with increased risk of progression. In the multivariate model which evaluated fixed laboratory covariates, T4/T8 ratio, IgA level, and PHA response at enrollment were significantly associated with elevated risk.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
58.
59.
Rainer O. Seidl Ingo Todt Arne Ernst 《European archives of oto-rhino-laryngology》2007,264(3):291-293
We report on a case of esophageal atresia following cervical spine surgery. A swallowing examination was performed using fibre-optic
endoscopy and videofluoroscopy. There was scar tissue fixation of the larynx and esophagus to the cervical spine. Operative
mobilization of the larynx and esophagus and formation of a sliding layer using a platysma-fascia flap was done. The PEG and
tracheal cannula were removed; oral nutrition was initiated after 3 months. Swallowing disorders following operations on the
upper cervical spine should be investigated. Careful preparation that preserves the layers should be carried out. Fixation
of tissues as a result of scarring should be treated with a sliding layer. 相似文献
60.
We review our experience with brain abscesses presenting as primary brain tumor over a 5-year period (1983 to 1988). Four of 66 (6%) patients admitted with the diagnosis of primary brain tumor by computed tomographic scans were found at craniotomy to have brain abscesses. Periapical abscesses found after surgery were determined to be the cause of brain abscess in two of four patients. Our experience suggests that periapical abscess may be a more frequent cause of brain abscess than previously thought, and should be considered before surgery in patients with a suspected brain tumor. 相似文献