全文获取类型
收费全文 | 5522篇 |
免费 | 523篇 |
国内免费 | 30篇 |
专业分类
耳鼻咽喉 | 23篇 |
儿科学 | 213篇 |
妇产科学 | 101篇 |
基础医学 | 646篇 |
口腔科学 | 74篇 |
临床医学 | 602篇 |
内科学 | 1076篇 |
皮肤病学 | 71篇 |
神经病学 | 502篇 |
特种医学 | 217篇 |
外科学 | 723篇 |
综合类 | 144篇 |
一般理论 | 4篇 |
预防医学 | 619篇 |
眼科学 | 150篇 |
药学 | 359篇 |
中国医学 | 10篇 |
肿瘤学 | 541篇 |
出版年
2023年 | 45篇 |
2022年 | 83篇 |
2021年 | 222篇 |
2020年 | 105篇 |
2019年 | 224篇 |
2018年 | 181篇 |
2017年 | 127篇 |
2016年 | 148篇 |
2015年 | 159篇 |
2014年 | 192篇 |
2013年 | 286篇 |
2012年 | 333篇 |
2011年 | 309篇 |
2010年 | 184篇 |
2009年 | 150篇 |
2008年 | 268篇 |
2007年 | 267篇 |
2006年 | 275篇 |
2005年 | 253篇 |
2004年 | 254篇 |
2003年 | 240篇 |
2002年 | 174篇 |
2001年 | 182篇 |
2000年 | 144篇 |
1999年 | 113篇 |
1998年 | 53篇 |
1997年 | 36篇 |
1996年 | 40篇 |
1995年 | 34篇 |
1994年 | 31篇 |
1993年 | 35篇 |
1992年 | 63篇 |
1991年 | 65篇 |
1990年 | 49篇 |
1989年 | 51篇 |
1988年 | 43篇 |
1987年 | 58篇 |
1986年 | 33篇 |
1985年 | 42篇 |
1984年 | 29篇 |
1983年 | 31篇 |
1982年 | 23篇 |
1979年 | 22篇 |
1978年 | 27篇 |
1977年 | 34篇 |
1976年 | 24篇 |
1975年 | 27篇 |
1974年 | 28篇 |
1972年 | 32篇 |
1970年 | 24篇 |
排序方式: 共有6075条查询结果,搜索用时 62 毫秒
61.
Tse GM Tsang AK Putti TC Scolyer RA Lui PC Law BK Karim RZ Lee CS 《Journal of clinical pathology》2005,58(2):185-189
BACKGROUND/AIMS: CD10 (CALLA) has recently been reported to be expressed in spindle cell neoplasia, and has been used to differentiate endometrial stromal sarcoma from leiomyoma and leiomyosarcoma. In the breast, myoepithelial cells express CD10, but there are few studies of the expression of CD10 in mammary fibroepithelial lesions. METHODS: Stromal CD10 expression was studied in 181 mammary phyllodes tumours (102 benign, 51 borderline malignant, and 28 frankly malignant) and 33 fibroadenomas using immunohistochemistry, to evaluate whether differences in expression correlated with the degree of malignancy. RESULTS: There was a progressive increase in the patients' age and tumour size, from fibroadenoma to phyllodes tumours with an increasing degree of malignancy (p < 0.001). Stromal CD10 expression was positive in one of 33 fibroadenomas, six of 102 benign phyllodes tumours, 16 of 51 borderline malignant phyllodes tumours, and 14 of 28 frankly malignant phyllodes tumours. The difference was significant (p < 0.001) and an increasing trend was established. Strong staining was seen in subepithelial areas with higher stromal cellularity and activity. Stromal CD10 expression had a high specificity (95%) for differentiating between benign lesions (fibroadenomas and benign phyllodes tumours) and malignant (borderline and frankly malignant) phyllodes tumours. CONCLUSIONS: CD10 may be a useful adjunct in assessing malignancy in mammary fibroepithelial lesions. 相似文献
62.
Winnie K. W. So Judy Y. W. Chan Bernard M. H. Law Kai Chow Choi Jessica Y. L. Ching Kam Leung Chan Raymond S. Y. Tang Carmen W. H. Chan Justin C. Y. Wu Stephen K. W. Tsui 《Nutrients》2021,13(2)
Rice bran exhibits chemopreventive properties that may help to prevent colorectal cancer (CRC), and a short-term rice bran dietary intervention may promote intestinal health via modification of the intestinal microbiota. We conducted a pilot, double-blind, randomised placebo-controlled trial to assess the feasibility of implementing a long-term (24-week) rice bran dietary intervention in Chinese subjects with a high risk of CRC, and to examine its effects on the composition of their intestinal microbiota. Forty subjects were randomised into the intervention group (n = 19) or the control group (n = 20). The intervention participants consumed 30 g of rice bran over 24-h intervals for 24 weeks, whilst the control participants consumed 30 g of rice powder on the same schedule. High rates of retention (97.5%) and compliance (≥91.3%) were observed. No adverse effects were reported. The intervention significantly enhanced the intestinal abundance of Firmicutes and Lactobacillus, and tended to increase the Firmicutes/Bacteroidetes ratio and the intestinal abundance of Prevotella_9 and the health-promoting Lactobacillales and Bifidobacteria, but had no effect on bacterial diversity. Overall, a 24-week rice bran dietary intervention was feasible, and may increase intestinal health by inducing health-promoting modification of the intestinal microbiota. Further larger-scale studies involving a longer intervention duration and multiple follow-up outcome assessments are recommended. 相似文献
63.
64.
Wing-Hoi Cheung Vivian Wing-Yin Hung Ka-Yee Cheuk Wai-Wang Chau Kelvin Kam-Fai Tsoi Ronald Man-Yeung Wong Simon Kwoon-Ho Chow Tsz-Ping Lam Patrick Shu-Hang Yung Sheung-Wai Law Ling Qin 《Journal of bone and mineral research》2021,36(12):2381-2398
Osteoporosis is a systemic skeletal disease characterized by low bone mass and bone structural deterioration that may result in fragility fractures. Use of bone imaging modalities to accurately predict fragility fractures is always an important issue, yet the current gold standard of dual-energy X-ray absorptiometry (DXA) for diagnosis of osteoporosis cannot fully satisfy this purpose. The latest high-resolution peripheral quantitative computed tomography (HR-pQCT) is a three-dimensional (3D) imaging device to measure not only volumetric bone density, but also the bone microarchitecture in a noninvasive manner that may provide a better fracture prediction power. This systematic review and meta-analysis was designed to investigate which HR-pQCT parameters at the distal radius and/or distal tibia could best predict fragility fractures. A systematic literature search was conducted in Embase, PubMed, and Web of Science with relevant keywords by two independent reviewers. Original clinical studies using HR-pQCT to predict fragility fractures with available full text in English were included. Information was extracted from the included studies for further review. In total, 25 articles were included for the systematic review, and 16 articles for meta-analysis. HR-pQCT was shown to significantly predict incident fractures and/or major osteoporotic fractures (MOFs). Of all the HR-pQCT parameters, our meta-analysis revealed that cortical volumetric bone mineral density (Ct.vBMD), trabecular thickness (Tb.Th), and stiffness were better predictors. Meanwhile, HR-pQCT parameters indicated better performance in predicting MOFs than incident fractures. Between the two standard measurement sites of HR-pQCT, the non-weight-bearing distal radius was a more preferable site than distal tibia for fracture prediction. Furthermore, most of the included studies were white-based, whereas very few studies were from Asia or South America. These regions should build up their densitometric databases and conduct related prediction studies. It is expected that HR-pQCT can be used widely for the diagnosis of osteoporosis and prediction of future fragility fractures. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR). 相似文献
65.
Steven Bruch Taylor Paige Karly Saez Chelsea Hall Marjorie Jolly Shannon Russell Monita Karmakar Megan O'Neill 《Journal of pediatric surgery》2021,56(4):717-720
Background/purposeOwing to the frequency of gastrostomy tube placement in children and the numerous regimens used to start feeds after placement we attempted to see if it matters if the initial feeds after a gastrostomy tube placement are provided in a bolus or continuous manner.MethodsUsing a prospective randomized trial, children were randomized to initial bolus or continuous chimney feeding after gastrostomy tube placement. Feeding tolerance and complications related to the gastrostomy tube were collected for 4 weeks after placement.ResultsDemographics were similar in the two groups. Times to goal feeds were similar in both groups, but in the first two weeks more feeding modifications were required in the bolus group. Other than the rate of leakage during the second week after placement which occurred more in the bolus group, all other clinical outcomes were similar in the two groups.ConclusionsOther than minor, clinically insignificant differences noted above, the method of initial feeding after a gastrostomy tube placement does not affect feeding tolerance or gastrostomy tube complication in the first month after placement.Level of evidenceTherapeutic, level II. 相似文献
66.
Baskin Alison S. Dossett Lesly A. Harris Chelsea A. 《Annals of surgical oncology》2021,28(8):4088-4092
Annals of Surgical Oncology - Recognizing the need to raise awareness of core diversity, equity, and inclusion (DEI) issues in the healthcare system, our previously developed Cultural Complications... 相似文献
67.
68.
JS Tsang Chi Chung Foo Jeremy Yip Hok Kwok Choi Wai Lun Law Oswens Siu Hung Lo 《The surgeon》2021,19(3):150-155
IntroductionThe difference in outcome between right (RCD) and left colonic diverticulitis (LCD) is not well established. The aim of this study was to analyse the presentation and surgical outcome of RCD versus left-sided disease following emergency surgery.MethodWe conducted a retrospective review of patients presenting with acute diverticulitis over a 10-year period from 2004 to 2014 to a tertiary unit. Patient demographics, Hinchey classification, need for emergency surgery, perioperative outcome and recurrence were evaluated.ResultsIn total 360 patients presented with acute diverticulitis, 218 (61%) were right-sided and 142 (39%) were left-sided. The mean age (57 yrs vs 68 yrs) and median length of stay (4 days vs 5 days) were significantly less in RCD (p < 0.001). The need for emergency surgery was similar between RCD and LCD (30.7% vs 23.2%, p = 0.12). Sixty-seven (31%) patients with RCD required emergency surgery, 42 (62.7%) of these were based on a presumptive diagnosis of appendicitis and underwent laparoscopic appendicectomy only. Operative morbidity (10.4% vs 51.5%, p < 0.001) and mortality were significantly higher in LCD (1.5% v 15.2%, p = 0.007). Subgroup analysis of non-appendicectomy, RCD patients, showed LCD were more likely to require surgery (11.5% vs 23.2%, p = 0.003). There was no difference in recurrence (p = 0.6).ConclusionRight colonic diverticulitis patients are younger and disease course is more benign compared to LCD. Presentation can be confused with appendicitis without proper imaging. In the rare cases where emergency surgery is required, RCD is associated with a lower operative morbidity and mortality compared to left-sided disease. 相似文献
69.
Chelsea Cox 《Health policy (Amsterdam, Netherlands)》2021,125(1):12-16
The regulatory framework for access to medical cannabis has been established in Canada since 2001, with the number of patients seeking access growing substantially over the years. With the novel enactment of the Cannabis Act in October 2018, Canada now maintains two distinct mechanisms for accessing cannabis - one for medical cannabis and the other for non-medical cannabis. With two regulatory access mechanisms in place, questions have arisen in the country as to the necessity of maintaining regulatory separation and the integrity of the medical access framework. A single framework would remove the gate-keeping function that the medical profession currently holds, streamlining processes and simplifying the current regulatory landscape. This approach has been advocated for by the Canadian Medical Association, despite objections from multiple stakeholders. Critical questions arise should the medical access framework be dissolved into a single, non medical-based regulatory framework. Insurance coverage, control mechanisms, market incentives, and patient obligations represent some examples of these issues. This paper will expand upon these considerations and highlight why maintaining two separate access mechanismss best serves the Canadian public. As medicinal cannabis continues to be liberated in international jurisdictions, this paper can help to illuminate the current status of medical cannabis in Canada, and provide insights to those from other countries on our current approach and domestic challenges. 相似文献
70.
The nucleotide sequence of Impatiens necrotic spot virus (INSV) M RNA was determined from cDNA clones. The INSV M RNA was 4972 nucleotides in length with two open reading frames (ORFs) in an ambisense genomic organization. The larger ORF near the 3' end of the viral RNA, coding for a protein with a predicted molecular weight of 124.9 kDa, was in the viral complementary sense and produced the G2 and G1 proteins. A smaller ORF in the viral sense was capable of coding for a 34.1-kDa polypeptide, designated the NSm protein. Two subgenomic RNA species were detected in INSV-infected tissue that corresponded to the predicted sizes (3.3 and 1.0 kb) of the G2-G1 and NSm mRNAs. The ORFs were separated by a 478 nucleotide A-U-rich intergenic region similar to the regions found in other viral RNAs with ambisense ORFs. The intergenic region was predicted to form a stable stem-loop structure (-81.2 kcal/mole). The ambisense genomic organization is characteristic of the S RNA for members of the Phlebovirus, Uukuvirus, and Tospovirus genera in the Bunyaviridae family. This is the first report of an ambisense Bunyaviridae M RNA. 相似文献