全文获取类型
收费全文 | 6661篇 |
免费 | 429篇 |
国内免费 | 76篇 |
专业分类
耳鼻咽喉 | 111篇 |
儿科学 | 194篇 |
妇产科学 | 91篇 |
基础医学 | 861篇 |
口腔科学 | 264篇 |
临床医学 | 522篇 |
内科学 | 1494篇 |
皮肤病学 | 227篇 |
神经病学 | 348篇 |
特种医学 | 460篇 |
外科学 | 949篇 |
综合类 | 60篇 |
预防医学 | 367篇 |
眼科学 | 162篇 |
药学 | 420篇 |
中国医学 | 64篇 |
肿瘤学 | 572篇 |
出版年
2024年 | 8篇 |
2023年 | 64篇 |
2022年 | 137篇 |
2021年 | 269篇 |
2020年 | 156篇 |
2019年 | 196篇 |
2018年 | 239篇 |
2017年 | 203篇 |
2016年 | 284篇 |
2015年 | 323篇 |
2014年 | 353篇 |
2013年 | 386篇 |
2012年 | 574篇 |
2011年 | 520篇 |
2010年 | 335篇 |
2009年 | 216篇 |
2008年 | 378篇 |
2007年 | 355篇 |
2006年 | 324篇 |
2005年 | 318篇 |
2004年 | 279篇 |
2003年 | 222篇 |
2002年 | 191篇 |
2001年 | 116篇 |
2000年 | 109篇 |
1999年 | 98篇 |
1998年 | 46篇 |
1997年 | 41篇 |
1996年 | 29篇 |
1995年 | 22篇 |
1994年 | 23篇 |
1993年 | 22篇 |
1992年 | 27篇 |
1991年 | 40篇 |
1990年 | 20篇 |
1989年 | 30篇 |
1988年 | 24篇 |
1987年 | 20篇 |
1986年 | 17篇 |
1985年 | 31篇 |
1984年 | 11篇 |
1983年 | 6篇 |
1982年 | 12篇 |
1981年 | 13篇 |
1980年 | 11篇 |
1979年 | 14篇 |
1978年 | 7篇 |
1977年 | 5篇 |
1973年 | 5篇 |
1966年 | 6篇 |
排序方式: 共有7166条查询结果,搜索用时 15 毫秒
91.
Perceptual variation in grading hand, hip and knee radiographs: observations based on an Australian twin registry study of osteoarthritis 下载免费PDF全文
Bellamy N Tesar P Walker D Klestov A Muirden K Kuhnert P Do KA O'Gorman L Martin N 《Annals of the rheumatic diseases》1999,58(12):766-769
OBJECTIVE: The radiographic diagnosis of osteoarthritis (OA) in the peripheral skeleton is dependent on the skilled examination of several morphological characteristics of the condition as visualised on plain radiographs. However, the process is perceptual and generally enhanced by comparison against photographic standards. This study assessed the intra-rater and inter-rater reliability of radiologists experienced in reporting hand, hip and knee films derived from a community-based sample when using the photographic atlas recently developed by Burnett et al. METHODS: This study was part of a multifaceted diagnostics protocol, evaluating methodological issues, in the conduct of genetic research in osteoarthritis. From a cohort of 118 twin pairs, registered with the Australian Twins Registry (ATR), standard clinical examinations were performed on 74 complete and 11 incomplete pairs of twins over age 50 years, followed by standard AP hand, AP pelvis and AP standing radiographs of the knees. The pairs were selected both to represent twin pairs who had previously self reported a diagnosis of OA, as well as those who had not. Radiologists read the films blind to the original self reported diagnosis and without reference to their pairing. The films were read by comparison against photographic standards and were scored according to specific features. All films were read independently by two consultant radiologists blind to one another's assessments, and selected films were thereafter assigned for rereading. Inter-rater and intra-rater agreement were different for different features, different anatomic areas, and, for the former, were different for the two radiologists. RESULTS: Inter-rater agreement was different for different anatomic areas, different radiographic features, and the two radiologists. Intra-rater agreement for the presence or absence of OA was as follows: actual observed agreement = 0.79 to 0.97 and 0.83 to 0.98; adjusted kappa statistic = 0.58 to 0.94 and 0.67 to 0.96; inter-rater agreement was as follows: actual observed agreement = 0. 77 to 0.97; adjusted kappa statistic = 0.54 to 0.94. Agreement was generally high in most of the principal target joints for OA: DIP, PIP, 1st CMC, hip and knee. CONCLUSIONS: Although assessor agreement was not perfect, it is concluded that for genetic epidemiology purposes, while duplicate assessments may be advantageous, it is possible for radiographs to be examined accurately by a single experienced assessor. However, for less experienced assessors independent examinations should be made by at least two assessors and either a consensus reached on disparate examinations or an algorithm developed to adjudicate any discrepancies. 相似文献
92.
[Purpose] Little is known about the outcome differences between men and women after
anterior cruciate ligament (ACL) reconstruction. Therefore, the present study aimed to
compare knee muscle strength between men and women 1 year after ACL reconstruction.
[Subjects and Methods] Retrospective and outcome study. Between 2012 and 2015, 35 males
(mean age, 29.7 ± 010.7 years) and 35 females (mean age, 28.2 ± 11.3 years) who had
undergone primary ACL reconstruction were recruited from Samsung medical centers. We
assessed the strength deficit in the quadriceps (extensor) and hamstrings (flexor) at
60°/sec and 180°/sec with isokinetic testing equipment. Statistical analysis was conducted
with a t-test to determine if sex differences existed in knee strength
deficit. [Results] Significant differences were noted between men and women with respect
to extensor muscle strength deficit. Women reported less extensor muscle strength than men
did, at the angular velocities 60°/sec and 180°/sec. However, no significant sex
differences were found at either velocity with respect to the strength deficit of the knee
flexor muscles. [Conclusion] Compared to male patients, female patients reported
significantly less extensor muscle strength and less improvement 1 year after
reconstruction.Key words: Anterior cruciate ligament, Sex, Female 相似文献
93.
94.
Chang Wan Kim Do Hyung Kim Bong Soo Son Jeong Su Cho Yeong Dae Kim Hoseok I Hyo Yeong Ahn 《Annals of thoracic and cardiovascular surgery》2015,21(6):517-522
Introduction: Extracorporeal membrane oxygenation (ECMO) is widely used to treat respiratory distress during cardiac or respiratory arrest; moreover, its use is being extended to a wide variety of clinical fields. In this study we assess the utility of ECMO in the management of airway obstruction.Patients and Methods: 15 patients underwent ECMO for airway obstruction. We retrospectively analyzed and evaluated the feasibility of ECMO in the treatment of airway problems.Results: Seven patients received ECMO to facilitate respiration and promote stability during trachea surgery. In six cases ECMO ceased immediately following the operation; in the remaining case ECMO cessation was delayed due to post-operative ARDS. In three cases emergency ECMO was used in response to respiratory arrest; two patients died. In five cases ECMO was emergently inserted to prevent death, following airway blockade by massive hemoptysis. One patient was not discharged from the intensive care unit. Another patient was transferred to a general ward but died from other causes.Conclusion: ECMO is useful during anesthesia in patients at high risk of airway blockade, for example due to endobronchial bleeding, and during complex thoracic surgery. ECMO confers a safer environment during airway surgery, and its complication rate is acceptable. 相似文献
95.
Xanthoma disseminatum (XD) is a rare normolipemic mucocutaneous xanthomatosis due to the proliferation of non-x histiocytes. Occasional involvement of the upper respiratory system has been reported, but lower respiratory tract involvement is very rare. Here, we present a child with severe involvement of the upper and lower respiratory tract by XD and bronchiectasis in the lower lobes of both lungs. The patient was an 8-year-old boy who was admitted to our hospital because of red-brown papules which developed on the skin and progressive dyspnea. He was diagnosed as having XD by skin biopsy. Physical examination revealed disseminated, numerous yellow-reddish brown papular xanthomas on the forehead and eyelids, around the neck and axillary area, and in the oral cavity and pharynx. He had respiratory distress and clubbing of the fingers. Chest x-rays showed hyperaeration and segmental atelectasis. High-resolution CT of the thorax revealed diffuse thickening of the whole tracheal and bronchial wall, and bronchiectasis in the lower lobes. Flexible fiberoptic bronchoscopy revealed numerous xanthomatous lesions in the nasal cavity, nasopharynx, oropharynx, subglottic area, trachea, bifurcation, both main bronchi, and smaller bronchi. To the best of our knowledge, this is the first report of a child with typical lesions of XD with severe involvement of the lower respiratory tract and bronchiectasis. 相似文献
96.
97.
98.
Park YJ Lee YJ Kim SH Joung DS Kim BJ So I Park do J Cho BY 《Molecular and cellular endocrinology》2008,285(1-2):19-25
Ghrelin regulates cell proliferation through the growth hormone secretagogue receptor (GHS-R). We confirmed the expression of GHS-R in FRTL-5 thyroid cells and investigated the effects of ghrelin in thyrocytes using FRTL-5 cells. Ghrelin increased intracellular calcium levels but not intracellular cyclic AMP levels. Ghrelin activated Erk within 2min, then activated Akt and STAT3. Erk phosphorylation was inhibited by the calcium inhibitor cyclopiazonic acid (CPA). Ghrelin alone did not stimulate FRTL-5 cell proliferation but enhanced the effects of thyroid stimulating hormone (TSH). Pretreatment with TSH potentiates the growth effects of ghrelin in thyroid cells, and p66Shc, a growth factor receptor adaptor protein, might mediate these synergistic effects. Ghrelin phosphorylated TSH-induced p66Shc, which was inhibited by CPA. Ghrelin did not affect the proliferation of ARO cells, which showed no increased expression of p66Shc after TSH treatment. Thus, ghrelin-induced intracellular calcium signaling enhanced the TSH-induced proliferation of thyrocytes, possibly mediated by the p66Shc pathway. 相似文献
99.
Esra Akyüz ?zkan Ceren Canbey G?ret Zeynep Tu?ba ?zdemir Serdar Yan?k Meryem Do?an Aylin G?nülta? Ay?e Neslin Akkoca 《International journal of clinical and experimental pathology》2015,8(9):11543-11548
Background: Although primary bone tumors are relatively uncommon, they constitute the most important tumors in patients less than 20 years. We aimed to determine the frequencies of primary bone tumors and tumor-like lesions of bone and the anatomical sites of their occurrence. Methods: A retrospective review of histopathology reports of all bone specimens received in a private pathology laboratory in Istanbul between 2009 and 2015. Results: A total of 57 patients (aged 5 to 18 years) with a mean of 13.12 years were studied. Thirty five patients (61.4%) were males and 22 (38.6%) were females. Fifty five (94.4%) of the tumors were benign. Osteochondroma was the commonest tumor accounting for 31 cases (54.3%) followed by osteoid osteoma, 9 cases (15.7%). Chondrosarcoma observed in two patients and Ewing sarcoma in one patient as malignant tumors. Of the 57 bone tumors 13 (22.8%) occurred in the upper extremities, while 44 (77.2%) were in the lower extremities. Proximal humerus was the most commonly involved site in upper extremity tumors, with osteochondromas representing the most frequent type of tumor (4 patients; 7%). In the lower extremities again osteochondromas were the most common type of tumor (8 cases, 14%), with the femur being the most common site of involvement (18 patients, 31.5%). Of the patients with tumor-like lesions; four patients had fibrous dysplasia, 4 patients had non-ossified fibromas, 4 patients had simple bone cysts and 3 had aneurismal bone cyst. Conclusion: This study showed that primary bone tumors were mainly benign, settled predominantly in the lower extremities mostly in the femur with a male preponderance. Osteochondroma was the most common benign bone tumor. We didn’t observed osteosarcoma, which is the most frequent malignant bone tumor. 相似文献