全文获取类型
收费全文 | 21578篇 |
免费 | 6031篇 |
国内免费 | 126篇 |
专业分类
耳鼻咽喉 | 631篇 |
儿科学 | 635篇 |
妇产科学 | 704篇 |
基础医学 | 418篇 |
口腔科学 | 2650篇 |
临床医学 | 4244篇 |
内科学 | 5158篇 |
皮肤病学 | 455篇 |
神经病学 | 1874篇 |
特种医学 | 1036篇 |
外科学 | 3886篇 |
综合类 | 64篇 |
现状与发展 | 12篇 |
一般理论 | 10篇 |
预防医学 | 2736篇 |
眼科学 | 367篇 |
药学 | 235篇 |
中国医学 | 7篇 |
肿瘤学 | 2613篇 |
出版年
2024年 | 137篇 |
2023年 | 1091篇 |
2022年 | 356篇 |
2021年 | 641篇 |
2020年 | 1223篇 |
2019年 | 485篇 |
2018年 | 1339篇 |
2017年 | 1288篇 |
2016年 | 1519篇 |
2015年 | 1566篇 |
2014年 | 1969篇 |
2013年 | 2378篇 |
2012年 | 785篇 |
2011年 | 757篇 |
2010年 | 1365篇 |
2009年 | 1952篇 |
2008年 | 742篇 |
2007年 | 509篇 |
2006年 | 668篇 |
2005年 | 471篇 |
2004年 | 334篇 |
2003年 | 319篇 |
2002年 | 286篇 |
2001年 | 400篇 |
2000年 | 305篇 |
1999年 | 405篇 |
1998年 | 511篇 |
1997年 | 497篇 |
1996年 | 548篇 |
1995年 | 396篇 |
1994年 | 313篇 |
1993年 | 265篇 |
1992年 | 207篇 |
1991年 | 175篇 |
1990年 | 161篇 |
1989年 | 158篇 |
1988年 | 140篇 |
1987年 | 135篇 |
1986年 | 119篇 |
1985年 | 113篇 |
1984年 | 90篇 |
1983年 | 104篇 |
1982年 | 89篇 |
1981年 | 73篇 |
1980年 | 45篇 |
1979年 | 39篇 |
1978年 | 36篇 |
1977年 | 49篇 |
1976年 | 37篇 |
1975年 | 33篇 |
排序方式: 共有10000条查询结果,搜索用时 406 毫秒
991.
Jeffrey M. Farma MD Jonathan S. Zager MD Victor Barnica-elvir MD Christopher A. Puleo PAC Suroosh S. Marzban MS Dana E. Rollison PhD Jane L. Messina MD Vernon K. Sondak MD 《Annals of surgical oncology》2013,20(4):1360-1364
Background
In the United States in 2012, there were 16,060 new cases of chronic lymphocytic leukemia (CLL). Often CLL is clinically occult and first detected during pathologic evaluation of the sentinel lymph node biopsy (SLNB). We reviewed our experience of patients with the coexisting diagnosis of melanoma and CLL.Methods
An institutional review board-approved review was performed on patients with CLL and melanoma treated from 1995 to 2009 at Moffitt Cancer Center and compared with the incidence of melanoma and CLL in our tumor registry patients with breast, prostate, lung, and colon cancer.Results
Fifty-two patients (44 males; median age, 71 years [range, 46–88]) were identified with concurrent diagnoses of melanoma and CLL. Twenty-two patients (42 %) had CLL on SLNB for their melanoma. Thirty-two patients (62 %) were diagnosed with melanoma before CLL. Concomitant or prior cancer diagnoses included nonmelanoma skin cancers (N = 29), prostate (N = 6), colorectal (N = 2), and Merkel cell carcinoma (N = 2). Five of 20 patients (25 %) had metastatic melanoma found at the time of SLNB. Patients with melanoma had a tenfold increase of CLL diagnosis compared with colorectal cancer patients, an eightfold increase compared to prostate cancer patients, and a fourfold increase compared with breast cancer patients.Conclusions
We have confirmed an increased association of CLL and melanoma. This may be related to an underlying immunologic defect; however, there has been scant investigation into this phenomenon. Surgeons and pathologists should understand this occurrence and recognize that not all grossly enlarged or abnormal sentinel lymph nodes in melanoma patients represent melanoma. 相似文献992.
Daniel X. Choi MD Anne A. Eaton MS Cristina Olcese BS Sujata Patil MPH PhD Monica Morrow MD FACS Kimberly J. Van Zee MS MD FACS 《Annals of surgical oncology》2013,20(4):1302-1310
Background
The histology of epithelial “borderline lesions” of the breast, which have features in between atypical ductal hyperplasia (ADH) and ductal carcinoma in situ (DCIS), is well described, but the clinical behavior is not. This study reports subsequent ipsilateral breast events (IBE) in patients with borderline lesions compared with those with DCIS.Methods
Patients undergoing breast-conserving surgery for borderline lesions or DCIS from 1997 to 2010 were identified from a prospective database. IBE was defined as the diagnosis of subsequent ipsilateral DCIS or invasive ductal carcinoma.Results
A total of 143 borderline-lesion patients and 2,328 DCIS patients were identified. Median follow-up was 2.9 and 4.4 years, respectively. 7 borderline-lesion and 172 DCIS patients experienced an IBE. 5 year IBE rates were 7.7 % for borderline lesions and 7.2 % for DCIS (p = .80). 5 year invasive IBE rates were 6.5 and 2.8 %, respectively (p = .25). Similarly, when analyses were restricted to patients who did not receive radiotherapy, or endocrine therapy, or both, borderline-lesion and DCIS patients did not demonstrate statistically significant differences in rates of IBE or invasive IBE.Conclusions
When compared with DCIS, borderline lesions do not demonstrate lower rates of IBE or invasive IBE. Despite “borderline” histology, a 5 year IBE rate of 7.7 % and an invasive IBE rate of 6.5 % suggest that the risk of future carcinoma is significant and similar to that of DCIS. 相似文献993.
Shawn T. Steen MD Alice P. Chung MD Soo-Hwa Han MD Arnold L. Vinstein MD Jeong L. Yoon MS Armando E. Giuliano MD 《Annals of surgical oncology》2013,20(2):633-639
Background
Preoperative assessment of the nipple–areolar complex (NAC) is invaluable when considering nipple-sparing mastectomy. Our hypothesis is that breast magnetic resonance imaging (MRI) may predict involvement of the NAC with tumor.Methods
Clinical, histopathologic, and imaging data were compiled for patients who underwent preoperative breast MRI followed by mastectomy or nipple-sparing mastectomy for malignancy between 2006 and 2009. Blinded rereview of all MRI studies was performed by a breast MRI imager and compared to initial MRI findings. Multivariate analysis identified variables predicting NAC involvement with tumor.Results
Of 77 breasts, 18 (23 %) had tumor involving or within 1 cm of the NAC. The sensitivity of detecting histopathologically confirmed NAC involvement was 61 % with history and/or physical examination, and 56 % with MRI. Univariate analysis identified the following variables as significant for NAC involvement: large tumors near the nipple on preoperative MRI, node-positive disease, invasive lobular carcinoma, advanced histopathologic T stage, and neoadjuvant chemotherapy. On multivariate analysis, only tumor size >2 cm and distance from tumor edge to the NAC <2 cm on MRI maintained significance. Pearson correlation coefficient for MRI size compared to histopathologic size was 0.53 (P < 0.0001).Conclusions
MRI is not superior to thorough clinical evaluation for predicting tumor in or near the NAC. However, MRI-measured tumor size and distance from the NAC are correlated with increased risk of NAC involvement. The combination of preoperative history and physical examination, tumor characteristics, and breast MRI can aid the surgeon in predicting a tumor-involved nipple more than any single modality alone. 相似文献994.
Andrea M. Abbott MD MS Helen M. Parsons PhD MPH Todd M. Tuttle MD MS Eric H. Jensen MD 《Annals of surgical oncology》2013,20(1):139-147
Introduction
The timing of surgical resection for stage IV colon cancer with liver metastasis and the safety of simultaneous colon and liver resection remains controversial. The purpose of our study was to evaluate short-term outcomes after combined colon and liver resection (CCLR) versus colon resection (CR) or liver resection alone (LR) using a population database.Methods
The National Inpatient Sample was used to select patients who had surgery for colon cancer from 2002 to 2006. We evaluated for in-hospital morbidity, mortality, and prolonged length of stay (PLOS). Our analysis was done using design-weighted unadjusted analysis and logistic regression.Results
We identified 361,096 patients during our study period (CCLR 3,625; CR 322,286; LR 35,185). CCLR was not associated with an increased risk of complications (odds ratio (OR) 1.12; 95 % confidence interval (CI) 0.94–1.33; P = 0.21) or PLOS (OR 1.19; 95 % CI 0.99–1.4; P = 0.06) compared with CR. In-hospital mortality occurred in 3.5 % of patients who underwent CCLR and was not significantly associated with mortality compared with CR alone (OR 1.17; 95 % CI 0.79–1.74; P = 0.43). Liver lobectomy with CR was associated with a PLOS and a trend toward increased morbidity and mortality. Significant predictors of complications, mortality, and PLOS included: age >70 years, male gender, nonprivate health insurance, and Elixhauser score >1.Conclusions
CCLR with limited liver resection can be performed with similar morbidity and mortality to colectomy alone. For patients who require hepatic lobectomy, however, strong consideration should be given to a staged approach. 相似文献995.
Ryan T. Groeschl MD T. Clark Gamblin MD MS Kiran K. Turaga MD MPH 《Annals of surgical oncology》2013,20(11):3591-3595
Background
Although many previous studies on local ablation outcomes for hepatocellular carcinoma (HCC) have dichotomized tumor size with a 3-cm cutoff to determine prognostic significance, a growing number of reports describe excellent outcomes for larger tumors. To address the logic of this 3-cm cutoff beyond small single-center experiences, we stratified patients by 1-cm tumor size intervals and hypothesized that disease-specific survival (DSS) would not vary significantly between adjacent groups.Methods
Patients treated with local ablation for T1 HCC (≤8 cm) were identified from the surveillance, epidemiology, and end results database (2004–2008). Log-rank tests and multivariable Cox proportional hazards models were used to compare DSS curves of adjacent study groups.Results
There were 1,083 patients included in the study (26 % female, median age: 62 years). The 3-year DSS was significantly lower in patients with 3- to 4-cm tumors compared to 2- to 3-cm tumors (58 vs. 72 %, p = 0.002). In adjusted models, DSS did not vary significantly between any size intervals up to 3 cm. Patients with 3- to 4-cm tumors, however, had a poorer prognosis compared with patients with 2- to 3-cm tumors (hazard ratio: 1.6, 95 % confidence interval: 1.18–2.18, p = 0.002). DSS also fell when tumor size increased from 5–6 to 6–7 cm (53 vs. 21 %, 0.006).Conclusions
This study emphasizes the 3-cm size, and possibly the 6-cm size, as informative predictive thresholds when ablating HCC, because variability of DSS occurred specifically at these tumor sizes. Future research in this field should either adopt a 3-cm breakpoint or provide evidence for alternative thresholds. 相似文献996.
Margaret L. Crivello MD Karen Ruth MS Elin R. Sigurdson MD PhD Brian L. Egleston PhD Kathryn Evers MD Yu-Ning Wong MD Marcia Boraas MD Richard J. Bleicher MD 《Annals of surgical oncology》2013,20(1):102-110
Background
Guidelines for breast cancer staging exist, but adherence remains unknown. This study evaluates patterns of imaging in early stage breast cancer usually reserved for advanced disease.Methods
Surveillance Epidemiology, and End Results data linked to Medicare claims from 1992–2005 were reviewed for stage I/II breast cancer patients. Claims were searched for preoperative performance of computed tomography (CT), positron emission tomography (PET), bone scans, and brain magnetic resonance imaging (MRI) (“advanced imaging”).Results
There were 67,874 stage I/II breast cancer patients; 18.8 % (n = 12,740) had preoperative advanced imaging. The proportion of patients having CT scans, PET scans, and brain MRI increased from 5.7 % to 12.4 % (P < 0.0001), 0.8 % to 3.4 % (P < 0.0001) and 0.2 % to 1.1 % (P = 0.008), respectively, from 1992 to 2005. Bone scans declined from 20.1 % to 10.7 % (P < 0.0001). “Breast cancer” (174.x) was the only diagnosis code associated with 62.1 % of PET scans, 37.7 % of bone scans, 24.2 % of CT, and 5.1 % of brain MRI. One or more symptoms or metastatic site was suggested for 19.6 % of bone scans, 13.0 % of CT, 13.0 % of PET, and 6.2 % of brain MRI. Factors associated (P < 0.05) with use of all modalities were urban setting, breast MRI and ultrasound. Breast MRI was the strongest predictor (P < 0.0001) of bone scan (odds ratio [OR] 1.63, 95 % confidence interval [CI] 1.44–1.86), Brain MRI (OR 1.74, 95 % CI 1.15–2.63), CT (OR 2.42, 95 % CI 2.12–2.76), and PET (OR 5.71, 95 % CI 4.52–7.22).Conclusions
Aside from bone scans, performance of advanced imaging is increasing in early stage Medicare breast cancer patients, with limited rationale provided by coded diagnoses. In light of existing guidelines and increasing scrutiny about health care costs, greater reinforcement of current indications is warranted. 相似文献997.
998.
Arun Jayaraman MS PT Prithvi Shah PT Christopher Gregory PhD PT Mark Bowden MS PT Jennifer Stevens PhD PT; Mark Bishop PhD PT; 《The journal of spinal cord medicine》2013,36(2):185-193
AbstractBackground/Objective: To determine whether 9 weeks of locomotor training (LT) results in changes in muscle strength and alterations in muscle size and activation after chronic incomplete spinal cord injury (SCI). Study Design: Longitudinal prospective case series.Methods: Five individuals with chronic incomplete SCI completed 9 weeks of LT. Peak isometric torque, torque developed within the initial 200 milliseconds of contraction (Torque200), average rate of torque development (ARTD), and voluntary activation deficits were determined using isokinetic dynamometry for the knee-extensor (KE) and plantar-flexor (PF) muscle groups before and after LT. Maximum muscle crosssectional area (CSA) was measured prior to and after LT.Results: Locomotor training resulted in improved peak torque production in all participants, with the largest increases in the more-involved PF (43.9% ± 20.0%), followed by the more-involved KE (21.1% ± 12.3%). Even larger improvements were realized in Torque200 and ARTD (indices of explosive torque), after LT. In particular, the largest improvements were realized in the Torque200 measures of the PF muscle group. Improvements in torque production were associated with enhanced voluntary activation in both the KE and ankle PF muscles and an increase in the maximal CSA of the ankle PF muscles.Conclusion: Nine weeks of LT resulted in positive alterations in the KE and PF muscle groups that included an increase in muscle size, improved voluntary activation, and an improved ability to generate both peak and explosive torque about the knee and ankle joints. 相似文献
999.
1000.