全文获取类型
收费全文 | 7444篇 |
免费 | 606篇 |
国内免费 | 65篇 |
专业分类
耳鼻咽喉 | 86篇 |
儿科学 | 117篇 |
妇产科学 | 137篇 |
基础医学 | 1101篇 |
口腔科学 | 105篇 |
临床医学 | 734篇 |
内科学 | 1812篇 |
皮肤病学 | 146篇 |
神经病学 | 603篇 |
特种医学 | 240篇 |
外科学 | 1028篇 |
综合类 | 153篇 |
一般理论 | 5篇 |
预防医学 | 536篇 |
眼科学 | 267篇 |
药学 | 396篇 |
中国医学 | 33篇 |
肿瘤学 | 616篇 |
出版年
2023年 | 77篇 |
2022年 | 159篇 |
2021年 | 294篇 |
2020年 | 192篇 |
2019年 | 250篇 |
2018年 | 315篇 |
2017年 | 201篇 |
2016年 | 239篇 |
2015年 | 254篇 |
2014年 | 317篇 |
2013年 | 409篇 |
2012年 | 567篇 |
2011年 | 547篇 |
2010年 | 335篇 |
2009年 | 296篇 |
2008年 | 433篇 |
2007年 | 434篇 |
2006年 | 365篇 |
2005年 | 325篇 |
2004年 | 287篇 |
2003年 | 249篇 |
2002年 | 178篇 |
2001年 | 131篇 |
2000年 | 101篇 |
1999年 | 85篇 |
1998年 | 43篇 |
1997年 | 35篇 |
1996年 | 47篇 |
1995年 | 32篇 |
1994年 | 33篇 |
1992年 | 59篇 |
1991年 | 58篇 |
1990年 | 59篇 |
1989年 | 52篇 |
1988年 | 37篇 |
1987年 | 41篇 |
1986年 | 35篇 |
1985年 | 45篇 |
1984年 | 33篇 |
1983年 | 38篇 |
1982年 | 32篇 |
1981年 | 33篇 |
1980年 | 25篇 |
1979年 | 35篇 |
1978年 | 20篇 |
1977年 | 18篇 |
1976年 | 18篇 |
1972年 | 17篇 |
1937年 | 41篇 |
1936年 | 38篇 |
排序方式: 共有8115条查询结果,搜索用时 15 毫秒
991.
Mehdi Trifa Sonia Ben Khalifa Ali Jendoubi Najeh Zribi Tarek Regaya Thomas Engelhardt 《Paediatric anaesthesia》2012,22(5):425-429
Background: The addition of clonidine to peripheral nerve blocks is controversial in children. Objective: The aim of our study was to evaluate the effect of clonidine added to ropivacaine in pediatric axillary brachial plexus block (ABPB). Methods: Children aged 1–6 years, scheduled to undergo forearm or hand surgery, were recruited into this prospective, double‐blind controlled trial. Patients were randomly allocated to receive an ABPB either with ropivacaine 0.2% 0.4 ml·kg?1 plus saline in 1 ml (RS) or ropivacaine 0.2% 0.4 ml·kg?1 plus clonidine 1 μg·kg?1 in 1 ml (RC). Primary endpoints were quality of postoperative analgesia as assessed by pain scores and total 24‐h postoperative analgesia requirements. Secondary outcomes were time to first analgesia request and duration of motor blockade. Results: Sixty patients were recruited (n = 30 per group) into the study. Pain scores were comparable throughout the first 24 h between the two groups. Ten children in the (RS) and six in (RC) groups required supplementary analgesia during the first 24 h (P = 0.24). Children who required further analgesia did so after 288 ± 94 min in the (RS) and 437 ± 204 min in the (RC) group (P = 0.06). There was no difference in the duration of motor block [186 ± 71 and 154 ± 56 min, P = 0.12 for (RS) and (RC), respectively]. Conclusion: Ropivacaine (0.2% 0.4 ml·kg?1) for ABPB provides sufficient postoperative analgesia in children scheduled for forearm or hand surgery. The addition of clonidine to ABPB does not improve overall postoperative analgesia but may increase the time to first analgesia request. 相似文献
992.
993.
994.
995.
Purpose
To investigate whether the universally accepted range of normal patellar height ratios derived from radiography for the Insall–Salvati (IS) and Blackburne–Peel (BP) methods could be similarly applied to both CT and MRI.Materials and methods
Institutional review board approval was obtained with waiver of informed consent for this HIPPA-compliant study. A total of 45 knees in 42 patients (15 men, 27 women; age range 11 to 75?years, mean age 39?±?20?years) who underwent tri-modality (radiograph, CT, and MRI) examinations were selected. All patients had knee imaging obtained for a variety of reasons and measurements were performed by two independent readers who were blinded to each other’s measurements or the respective measurements derived from each of the methods. Paired t test was used to compare the mean values among the modalities. Inter-observer and inter-method agreements were assessed using intra-class correlation coefficients.Results
Statistically significant, but small quantitative differences are noted between tri-modality patellar height ratios. For comparable results, the small addition of 0.13 and 0.10 are needed for the Insall–Salvati measurements on MRI and CT respectively, compared with radiographs. For the Blackburne–Peel ratio, an additional adjustment of 0.09 is needed between radiographs and MRI, but not between radiographs and CT. These adjustments are independent of gender. The interobserver reproducibility was excellent (ICC?≥?0.94) for both the Insall–Salvati and Blackburne–Peel methods for all modalities.Conclusion
The results indicate that cut-off values for patella alta and baja derived from radiographs should not be directly transposed to CT and MRI; however, the adjustments are relatively minor. These measurements show excellent reproducibility for all modalities currently used for patellar height measurements. 相似文献996.
TH Koh DY Cao KS Chan L Wijaya SB Low MS Lam EE Ooi LY Hsu 《Emerging infectious diseases》2012,18(9):1524-1525
TO THE EDITOR: Nordmann et al. (1) raised concern over the global spread of carbapenemase-producing Enterobacteriaceae. In their article, they called attention to the oxacillinase-48 (OXA-48) type carbapenemases because bacteria that produce these enzymes do not have a distinctive antimicrobial drug susceptibility profile, and there is less awareness of this mechanism of carbapenem resistance. We report the recent isolation of bla(OXA-181)-positive Klebsiella pneumoniae from 2 patients from Bangladesh who were admitted to separate hospitals in Singapore within a short period of each other. 相似文献
997.
Alimehmeti R Seferi A Rroji A Alimehmeti M 《Journal of infection in developing countries》2012,6(6):531-535
An unusual case of saphenous neuropathy secondary to compression by a large hydatid cyst within the adductor longus muscle is reported. Solitary hydatid cyst(s) localized in the skeletal muscles occur rarely and often mimic soft tissue tumours. Presentation with signs of peripheral nerve compression by a hydatid cyst in an extremity is exceedingly rare. Diagnosis can be established by ultrasound, computerized tomography or magnetic resonance if clinically suspected. Clinical suspicion of hydatid origin of a solitary muscle cyst should be high especially in patients hailing from areas endemic for echinococcosis. Laboratory tests are usually unhelpful in such cases and needle biopsy carries the risk of anaphylactic shock and should therefore be avoided. Surgical removal of the unruptured cyst is the treatment of choice in cases of intramuscular hydatid cyst. In the present case, excision of the hydatid cyst was followed by complete clinical recovery. In the absence of systemic involvement, treatment with albendazole may be avoided. 相似文献
998.
Conjunctival nodule is very rarely seen in patients with rheumatoid arthritis. Previously reported cases were associated with
the use of methotrexate. Here, we report a conjunctival rheumatoid nodule without such prior treatment. A 49-year-old woman
with seropositive rheumatoid arthritis, who was being treated only with oral steroids and hydroxychloroquine, developed diffuse
anterior scleritis in the right eye. In addition, examination showed a focal raised yellow/tan conjunctival nodule. The nodule
was within the bulbar conjunctiva with no attachments to the underlying tissue, which is different from nodular scleritis.
The nodule was not tender on palpation. The patient underwent excisional biopsy of the nodule. Intraoperatively, the lesion
was noted to be a firm nodule within substantia propria of the conjunctiva. Hematoxylin-eosin staining of the specimen revealed
a central area of necrosis surrounded by palisades of histiocytes. Increased dosage of oral steroid after the biopsy resulted
in resolution of the ocular symptoms and signs. In conclusion, rheumatoid nodules may be seen in the conjunctiva even without
prior treatment with methotrexate. These nodules may show the severity of the underlying disease and the need for more aggressive
treatment. 相似文献
999.
1000.
Elahi M Esmaili-Sari A Bahramifar N 《Bulletin of environmental contamination and toxicology》2012,88(1):60-64
Much of the variation in trace metal tissue concentrations in marine invertebrates has been attributed to the variety in individual
organism size, age and sex. This study assessed the relationship between total mercury (Hg) concentrations in edible tissue,
exoskeleton and viscera with length, weight and gender for 69 samples of crustaceans, Penaeus
semisulcatus (n = 30), Thenus
orientalis (n = 21) and Portunus
pelagicus (n = 18) from the northern part of the Persian Gulf. Significant increase in the Hg level in muscle and viscera (r > 0.65,
p < 0.01) with an increase in length and weight for all three species. No relationship was found between the Hg level in exoskeleton
and length or weight. Significantly higher Hg levels (p < 0.01) were found in female P.
semisulcatus than in males (muscle and viscera), but no gender differences were found for the other two species. 相似文献