全文获取类型
收费全文 | 222627篇 |
免费 | 29651篇 |
国内免费 | 7283篇 |
专业分类
耳鼻咽喉 | 1710篇 |
儿科学 | 2120篇 |
妇产科学 | 5310篇 |
基础医学 | 16727篇 |
口腔科学 | 2179篇 |
临床医学 | 19490篇 |
内科学 | 22446篇 |
皮肤病学 | 1450篇 |
神经病学 | 839篇 |
特种医学 | 7079篇 |
外国民族医学 | 272篇 |
外科学 | 31335篇 |
综合类 | 29222篇 |
现状与发展 | 39篇 |
一般理论 | 3篇 |
预防医学 | 10438篇 |
眼科学 | 131篇 |
药学 | 15159篇 |
146篇 | |
中国医学 | 5116篇 |
肿瘤学 | 88350篇 |
出版年
2024年 | 508篇 |
2023年 | 4473篇 |
2022年 | 7496篇 |
2021年 | 11998篇 |
2020年 | 11156篇 |
2019年 | 10163篇 |
2018年 | 9741篇 |
2017年 | 10055篇 |
2016年 | 10816篇 |
2015年 | 12461篇 |
2014年 | 18287篇 |
2013年 | 17873篇 |
2012年 | 14471篇 |
2011年 | 14784篇 |
2010年 | 10816篇 |
2009年 | 10995篇 |
2008年 | 11312篇 |
2007年 | 10704篇 |
2006年 | 9518篇 |
2005年 | 7863篇 |
2004年 | 6478篇 |
2003年 | 5451篇 |
2002年 | 4578篇 |
2001年 | 4223篇 |
2000年 | 3474篇 |
1999年 | 2960篇 |
1998年 | 2475篇 |
1997年 | 2206篇 |
1996年 | 1821篇 |
1995年 | 1660篇 |
1994年 | 1341篇 |
1993年 | 1053篇 |
1992年 | 910篇 |
1991年 | 837篇 |
1990年 | 628篇 |
1989年 | 562篇 |
1988年 | 489篇 |
1987年 | 454篇 |
1986年 | 347篇 |
1985年 | 418篇 |
1984年 | 349篇 |
1983年 | 238篇 |
1982年 | 248篇 |
1981年 | 232篇 |
1980年 | 181篇 |
1979年 | 140篇 |
1978年 | 96篇 |
1977年 | 73篇 |
1976年 | 65篇 |
1975年 | 40篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
《Journal of Cardiovascular Computed Tomography》2020,14(4):363-369
BackgroundData on left ventricular (LV) deformation imaging using CT angiography (CTA) are scarce and the feasibility of atrial deformation analysis by CT has not been addressed. We aimed to compare 2D echocardiographic and CT derived LV and left atrial (LA) global longitudinal strain (GLS) obtained by using a novel feature tracking algorithm in patients following transcatheter aortic valve implantation.MethodsTwenty-eight patients were included who underwent retrospectively-gated 256-slice CTA and speckle-tracking echocardiography (STE) on the same day. CT datasets in 10% increments were reconstructed throughout the cardiac cycle. LV GLS and LA global peak reservoir strain (LA GS) was measured.ResultsMedian absolute values for LV GLS were 19.9 [14.8–22.4] vs. 19.9 [16.8–24.7], as measured by CT vs STE, respectively (p = 0.017). We found good inter-modality correlation for LV GLS (ρ = 0.78, p < 0.05) with a mean bias of −1.6. Regarding atrial measurements, the median LA GS was 19.0 [13.5–27.3] for CT vs. 28.0 [17.5–32.6] for STE (p < 0.001) with a mean bias of −5.6 between CT and STE and a correlation coefficient of ρ = 0.87, p < 0.001. CT measurements were highly reproducible: intra-observer intra-class correlation coefficient was 0.96 for LV GLS and 0.95 for LA GS.ConclusionWe detected good correlation between CTA and echocardiography-based LV and LA longitudinal strain parameters. CTA provides accurate strain measurements with high reproducibility. Feature tracking-based deformation analysis could provide a clinically important addition to CT examinations by complementing anatomical information with functional data. 相似文献
103.
104.
Mark Verrill 《Surgery (Oxford)》2019,37(3):181-185
Multimodality primary therapies for breast cancer combined with earlier detection have led to a sharp decline in the death rate from breast cancer in the UK over the last 40 years in the face of a rising incidence. The latest UK statistics from Cancer Research UK report 55,122 new cases of breast cancer in 2015 with 11,563 deaths from breast cancer recorded in 2016. Crudely, this equates to a cure rate of around 80% for all comers and demonstrates a clear improvement in outcome with 50,285 new cases in 2011 and 11,716 deaths in 2012. Despite this good news, there are still significant numbers of women (and men) who suffer from either a local recurrence or metastatic disease following apparently successful treatment for early breast cancer (Stage I to III). Only a minority of individuals, 6.6% with the stage recorded at diagnosis, present with stage IV disease. This review considers the treatment options available to individuals with locally recurrent and advanced breast cancer (ABC). 相似文献
105.
Sathiyavelavan Gopalan Jagadesh Chandra Bose S. Periasamy 《The Indian journal of surgery》2015,77(3):232-236
The aim of this study is to review the literature to find out the exact etiology of anastomotic cancers of colon post resection and differentiate them between a recurrence, second primary, and metastatic disease (local manifestation of systemic disease). Web-based literature search was done, and datas collected. We searched PubMed for papers using the keywords colon cancer recurrence, anastomotic recurrence, and recurrent colon carcinoma. We also searched for systematic review in the same topic. In addition, we used our personal referrence archive. Anastomotic recurrences of colon are postulated to arise due to inadequate margins, tumor implantation by exfoliated cells, altered biological properties of bowel anastomosis, and missed synchronous lesions. Some tumors are unique with repeated recurrence after repeated resection. Duration after primary surgery plays a major role in differentiating recurrent and second primary lesions. Repeated recurrences after repeated resections have to be considered a manifestation of systemic disease or metastatic disease due to the virulence of the disease. A detailed analysis and study of patients with colonic anastomotic lesion are required to differentiate it between a recurrent, a second primary lesion, and a metastatic disease (local manifestation of a systemic disease). The nomenclature is significant to study the survival of these patients, as a second primary lesion will have different survival compared to that of recurrent lesions. 相似文献
106.
HER2-positive (HER2+) breast cancer (BC) is a heterogenous and multifaceted disease, with interesting therapeutic implications. First, all intrinsic molecular subtypes can be identified in HER2+ tumors, with the HER2-enriched being the most frequent. Such subtypes do not differ much from their counterparts in HER2-negative disease, apart for the high expression of genes in/near the HER2 amplicon on chromosome 17. Intrinsic subtyping, along with the quantification of ERBB2 mRNA levels, is associated with higher rates of pathologic complete response across neoadjuvant trials of dual HER2 blockade and might help select patients for de-escalation and escalation treatment strategies. Secondly, HER2+ tumors have a broad range of DNA alterations. ERBB2 mutations and alterations in the PI3K/Akt/mTOR pathway are among the most frequent and might predict benefit from potent pan-HER, PI3K and mTOR inhibitors. Moreover, HER2+ tumors are usually infiltrated by lymphocytes. These tumor infiltrating-lymphocytes (TILs) predict response to neoadjuvant anti-HER2-based treatment and exert a prognostic role. PD-L1, detected in ∼42 % of HER2+ BC, might also be useful to define patients responding to novel anti-PD1/PD-L1 immunotherapies. New multiparametric clinicopathologic and genomic tools accounting for this complexity, such as HER2DX, are under development to define more tailored treatment approaches. Finally, HER2-targeted antibody-drug conjugates (ADC) such as trastuzumab deruxtecan might be active in tumors with low expression of HER2. Overall, there is a need to molecularly characterize and develop novel targeted therapies for HER2+ disease. 相似文献
107.
108.
ObjectiveThis study used a prospective cohort study to observe the effect of triple-negative breast cancer on the 2-year disease-free survival rate with or without “TCM formula”.MethodsFrom November 1 st, 2016, the first patient was enrolled in the cohort study. A total of 356 patients were enrolled on January 30, 2019. Among them, 154 cases were followed up for 2 years. During the follow-up, there were 6 cases of shedding, so 6 cases were affected. A total of 148 cases were included in the analysis, including 73 in the exposed group and 75 in the non-exposed group. The exposed group was given “TCM formula” on the basis of standardized treatment, and the non-exposed group was treated with simple triple-negative breast cancer. The two groups visited each of the three months. The interview included safety examination (hematology and imaging). The endpoint was the difference in 2-year invasive disease-free survival between the exposed and non-exposed groups and the safety of the “TCM formula”.ResultsThere were 6 cases of shedding during the experiment and the shedding rate was 3.9 %. The 2-year rate of invasive disease-free survival in the exposed team was 88.7 % and the non-exposed group was 82.5 %. Logistic multivariate regression analysis predicted that “TCM formula” could reduce the disease-related recurrence and metastasis rate by 11 % (OR = 0.89, 95 % CI 0.37−0.956, P<0.05). Through K–M survival analysis, TNBC patients with age ≤35 years and regional lymph node stage N1 may be the benefit group of “TCM formula”(P<0.05). During the study, the incidence of total adverse events was 8.2 % in the exposed group, mainly manifested as stomach discomfort, diarrhea, and hepatocyte damage.Conclusion1. In the exposed group, the two-year rate of invasive disease-free survival increased by 6.2 % compared with the non-exposed group(P>0.05). 2. According to K–M survival analysis, TNBC patients with age ≤35 years and regional lymph node metastasis to N1 may be potential beneficiaries of “TCM formula”. 3. “TCM Formula” is safe and tolerable to most patients. 相似文献
109.
110.
Sweeka Alexander Gurjeet Dulku Sharbell Hashoul Donna B Taylor 《Journal of Medical Imaging and Radiation Oncology》2019,63(4):473-478
Contrast‐enhanced spectral mammography (CESM) has a number of uses including the work‐up of inconclusive findings on mammography, assessment of breast symptoms, cancer staging, evaluation of response to neoadjuvant chemotherapy and recently as an alternative to magnetic resonance imaging (MRI) in high‐risk screening. CESM can be swiftly incorporated into the workflow of busy breast clinics. We share our experiences with CESM at a large breast assessment centre in Western Australia. 相似文献