全文获取类型
收费全文 | 10341篇 |
免费 | 989篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 90篇 |
儿科学 | 328篇 |
妇产科学 | 162篇 |
基础医学 | 1523篇 |
口腔科学 | 353篇 |
临床医学 | 1139篇 |
内科学 | 1891篇 |
皮肤病学 | 226篇 |
神经病学 | 754篇 |
特种医学 | 426篇 |
外科学 | 1366篇 |
综合类 | 247篇 |
一般理论 | 4篇 |
预防医学 | 982篇 |
眼科学 | 198篇 |
药学 | 645篇 |
中国医学 | 14篇 |
肿瘤学 | 1011篇 |
出版年
2021年 | 133篇 |
2020年 | 89篇 |
2019年 | 123篇 |
2018年 | 156篇 |
2017年 | 128篇 |
2016年 | 134篇 |
2015年 | 156篇 |
2014年 | 195篇 |
2013年 | 382篇 |
2012年 | 444篇 |
2011年 | 473篇 |
2010年 | 289篇 |
2009年 | 266篇 |
2008年 | 401篇 |
2007年 | 489篇 |
2006年 | 437篇 |
2005年 | 421篇 |
2004年 | 431篇 |
2003年 | 388篇 |
2002年 | 367篇 |
2001年 | 297篇 |
2000年 | 330篇 |
1999年 | 290篇 |
1998年 | 133篇 |
1997年 | 129篇 |
1996年 | 110篇 |
1995年 | 105篇 |
1994年 | 94篇 |
1993年 | 108篇 |
1992年 | 274篇 |
1991年 | 251篇 |
1990年 | 212篇 |
1989年 | 228篇 |
1988年 | 173篇 |
1987年 | 199篇 |
1986年 | 195篇 |
1985年 | 219篇 |
1984年 | 136篇 |
1983年 | 135篇 |
1982年 | 103篇 |
1981年 | 88篇 |
1980年 | 89篇 |
1979年 | 133篇 |
1978年 | 91篇 |
1977年 | 92篇 |
1976年 | 96篇 |
1974年 | 87篇 |
1973年 | 93篇 |
1972年 | 92篇 |
1971年 | 92篇 |
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
31.
Microdochectomy for single-duct discharge from the nipple 总被引:2,自引:0,他引:2
A P Locker M H Galea I O Ellis H W Holliday C W Elston R W Blamey 《The British journal of surgery》1988,75(7):700-701
Microdochectomy has been the accepted treatment for single-duct nipple discharge. Review of 97 consecutive patients undergoing microdochectomy between 1980 and 1987 revealed a total of eight patients with ductal carcinoma in situ. All of these had pre-operative mammography, results of which were highly suspicious of malignancy in six patients. Tiny foci of ductal carcinoma in situ were found in the two patients with normal mammograms. We suggest an expectant policy in cases where the mammogram is normal, omitting routine microdochectomy. 相似文献
32.
Cloning and expression analysis of the chick DAN gene, an antagonist of the BMP family of growth factors. 总被引:3,自引:0,他引:3
Lisa M Gerlach-Bank Amanda D Ellis Bridgette Noonen Kate F Barald 《Developmental dynamics》2002,224(1):109-115
Differential screening-selected gene aberrative in neuroblastoma (DAN) is a member of a cystine knot protein family that includes Cerberus and Gremlin. First isolated in a screen to identify genes down-regulated in transformed rat fibroblasts, DAN has subsequently been cloned in Xenopus, mouse, and human. Overexpression of DAN suppresses the transformed phenotype and retards the cell's entry into S phase. Biochemical analyses have demonstrated DAN's ability to bind bone morphogenetic proteins and antagonize their signaling activity. In this study, chick DAN was cloned and sequenced, revealing a conserved cystine knot region as well as an N-glycosylation site. A riboprobe was designed from the 3' chick DAN coding sequence and used for analysis of DAN in the developing chick embryo by in situ hybridization. Chick DAN was expressed beginning at stage 10 in the developing somites and the medial otic epithelium. Expression in the neural layer of the eye became apparent at stage 14. By stage 17, expression had expanded to the base of the hindbrain. Limb bud labeling began at stage 20, whereas expression in the branchial arches appeared at stage 25. Chick DAN expression generally corresponded to that of mouse DAN expression as shown by comparative in situ hybridization. However, chick DAN was found in the otic epithelium and notochord, whereas mouse DAN was restricted to the overlying otic ectomesenchyme and was absent from the notochord. This observation suggests that DAN may play different roles in chick and mouse otic and notochord development. 相似文献
33.
D R Cheetham L Burgess M Ellis A Williams R M Greenhalgh A H Davies 《European journal of vascular and endovascular surgery》2004,27(1):17-23
OBJECTIVE: Exercise advice is the main treatment for symptom relief in the UK for patients with mild to moderate Intermittent Claudication (IC). Would a weekly exercise and motivation class for 6 months offer adjuvant benefit over written and verbal exercise advice alone? PATIENTS AND METHODS: Fifty-nine patients attending a regional vascular centre for whom IC was the main factor affecting mobility were randomised to either exercise advice alone (n=30) or exercise advice with a once a week 45 min supervised exercise/motivation class (n=29). The mean age was 68 years. Baseline and 6-month assessment included a Quality of Life Questionnaire--the Short-Form-36, the Charing Cross Symptom Specific Claudication Questionnaire (CCCQ) and treadmill walking distance (3.5 km/h 12%). RESULTS: At 6-month follow-up the supervised exercise group had improved their treadmill walking by 129% compared to 69% in the advice alone group (p=0.001). This significant improvement was maintained at the subsequent 9 and 12-month follow-up assessments. By the 9-month stage the advice only group CCCQ score had improved 16% from baseline, while the supervised exercise group had a significantly better 43% improvement in base line score (p<0.05). Self reported frequency of walks was higher in the exercise class group being significant for improvement in CCCQ score. CONCLUSION: A weekly, supervised exercise and motivation class for a 6-month period provides a significant improvement in patients' symptoms, quality of life, and distance walked compared with advice alone and this improvement continues after attendance at class has ceased. 相似文献
34.
A case of pulmonary infection caused by Trichosporon beigelii is reported. The infection occurred in a neutropenic patient with acute lymphoblastic leukemia. His chest radiograph showed a 6-cm pulmonary infiltrate in the right midzone and an apical infiltrate on the left. Repeated cultures of bronchoalveolar lavage grew budding yeast that was identified as T beigelii on the basis of morphological, cultural, and biochemical characteristics. He responded to amphotericin-B therapy. Systemic infections caused by this yeast are rare and its causal relationship in localized lung disease has been reported only seven times previously. 相似文献
35.
36.
One of the most common errors in model surgery for orthognathic surgery is in the mounting of the models on the articulator. This study assessed the ability of one type of face-bow to transfer the maxillary model to the articulator. Twenty-five consecutive mountings were evaluated by calculating the angle made between the maxillary occlusal plane on the cephalogram and comparing it with the maxillary occlusal plane angle on the articulator. An accurate face-bow transfer should transfer this angle, making the two similar. It was found that a significant difference between the maxillary occlusal plane angle on the cephalogram and the articulator was found in the average case. The implications of such errors and a technique to avoid them are presented. 相似文献
37.
It was proposed that differences between paranoid and nonparanoid schizophrenics in the processing of affective information may reflect underlying differences in their schema for emotion-laden information. Performances of 14 paranoid schizophrenics, 13 nonparanoid schizophrenics, and 15 matched controls were compared on a facial affect judgment task, and a matched control task comprising geometric figures largely devoid of emotional information. Subjects were required to rate friendliness, select an emotion label, and subsequently to remember the stimuli. Nonparanoids were deficient in overall labeling of facial affect, suggesting a weak cognitive schema for emotional information. The paranoids were particularly more accurate than the nonparanoids at labeling the negative facial affects, suggesting well-developed negative emotional aspects in their cognitive schema. Unexpectedly, nonparanoids relative to paranoids displayed a greater memory deficit in the recognition of geometric figures than in the recognition of faces. The nonparanoid deficit suggests these subjects may have poorly organized schema for remembering less structured nonverbal information. The findings support the idea of fundamental cognitive processing differences between paranoid and nonparanoid schizophrenia. 相似文献
38.
39.
Ryan M McAdams Edward Mazuchowski Michael W Ellis Michael Rajnik 《Journal of perinatology》2005,25(10):677-679
Hospitalized neonates are commonly colonized soon after birth with Staphylococcus aureus. The majority of neonates do not develop infectious sequelae; however, premature neonates appear to be more susceptible to serious infections, such as pneumonia. We report a case of an extremely low birth weight infant who developed necrotizing pneumonia due to methicillin-resistant Staphylococcal aureus (MRSA). The MRSA isolate from this neonate is identical to the strains that have been causing primarily community-associated skin and soft tissue infections. The severe course of this patient may be attributed to the presence of the Panton-Valentine leukocidin gene, a well-known virulence factor leading to soft tissue and pulmonary infections. 相似文献
40.
One hundred methanolic plant extracts, 96 of which had documented medicinal uses by British Columbian native peoples, were screened for antibiotic activity against 11 bacterial strains. Eighty-five percent were found to have significant antibiotic activity against at least two of the bacteria tested. Ninety-five percent of the plants categorized as potential antibiotics based on their ethnobotanical usage were found to exhibit significant antibiotic activity. Seventy-five were found to be active against methicillin-resistant Staphylococcus aureus, 46 were active against an antibiotic supersusceptible strain of Pseudomonas aeruginosa and 18 of these were also active against a wild type strain. The extracts with the broadest spectra of activity were prepared from: Alnus rubra bark and catkins, Fragaria chiloensis leaves, Moneses uniflora aerial parts, and Rhus glabra branches. 相似文献