全文获取类型
收费全文 | 28630篇 |
免费 | 8545篇 |
国内免费 | 173篇 |
专业分类
耳鼻咽喉 | 257篇 |
儿科学 | 809篇 |
妇产科学 | 514篇 |
基础医学 | 5451篇 |
口腔科学 | 1053篇 |
临床医学 | 4063篇 |
内科学 | 6967篇 |
皮肤病学 | 570篇 |
神经病学 | 2183篇 |
特种医学 | 1911篇 |
外科学 | 6327篇 |
综合类 | 355篇 |
一般理论 | 12篇 |
预防医学 | 3094篇 |
眼科学 | 814篇 |
药学 | 1551篇 |
4篇 | |
中国医学 | 26篇 |
肿瘤学 | 1387篇 |
出版年
2021年 | 483篇 |
2020年 | 340篇 |
2018年 | 435篇 |
2017年 | 435篇 |
2016年 | 621篇 |
2015年 | 960篇 |
2014年 | 1621篇 |
2013年 | 2257篇 |
2012年 | 934篇 |
2011年 | 815篇 |
2010年 | 1320篇 |
2009年 | 1397篇 |
2008年 | 731篇 |
2007年 | 553篇 |
2006年 | 659篇 |
2005年 | 564篇 |
2004年 | 515篇 |
2003年 | 396篇 |
2002年 | 417篇 |
2001年 | 543篇 |
2000年 | 448篇 |
1999年 | 638篇 |
1998年 | 822篇 |
1997年 | 783篇 |
1996年 | 821篇 |
1995年 | 790篇 |
1994年 | 668篇 |
1993年 | 620篇 |
1992年 | 628篇 |
1991年 | 604篇 |
1990年 | 548篇 |
1989年 | 643篇 |
1988年 | 648篇 |
1987年 | 638篇 |
1986年 | 597篇 |
1985年 | 625篇 |
1984年 | 557篇 |
1983年 | 543篇 |
1982年 | 599篇 |
1981年 | 570篇 |
1980年 | 541篇 |
1979年 | 539篇 |
1978年 | 511篇 |
1977年 | 519篇 |
1976年 | 449篇 |
1975年 | 408篇 |
1974年 | 366篇 |
1973年 | 346篇 |
1972年 | 348篇 |
1971年 | 311篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
Gildasio S. De Oliveira Jr. MD MSCI Ray Chang BS Seema A. Khan MD Nora M Hansen MD Jamil H. Khan BS Robert J. McCarthy PharmD Apkar V Apkarian PhD 《The breast journal》2014,20(1):9-14
Chronic pain has been shown to affect up to 60% of patients undergoing surgery for breast cancer. Besides younger age, other risk factors for the development of chronic pain have not been consistent in previous studies. The objective of the current investigation was to detect the prevalence and risk factors for the development of chronic pain after breast cancer surgery by examining a patient population from a tertiary cancer center in the United States. The study was a prospective observational cohort study. Subjects were evaluated at least 6 months after the surgical procedure. Subjects responded to the modified short form Brief pain inventory and the short form McGill pain questionnaire to identify and characterize pain. Demographic, surgery, cancer treatment, and perioperative characteristics were recorded. Propensity matching regression analysis were used to examine risk factors associated with the development of chronic pain. 300 patients were included in the study. 110 reported the presence of chronic pain. Subjects with chronic pain reported median (interquartile range [IQR]) rating of worst pain in the last 24 hours of 4 (2–5) and a median (IQR) rating on average pain in the last 24 hours of 3 (1–4) on a 0–10 numeric rating scale. Independent risk factors associated with the development of chronic pain were age, OR (95% CI) of 0.95 (0.93–0.98) and axillary lymph node dissection, 7.7 (4.3–13.9) but not radiation therapy, 1.05(0.56–1.95). After propensity matching for confounding covariates, radiation was still not associated with the development of chronic pain. Chronic pain after mastectomy continues to have a high prevalence in breast cancer patients. Younger age and axillary lymph node dissection but not radiation therapy are risk factors for the development of chronic pain. Preventive strategies to minimize the development of chronic pain are highly desirable. 相似文献
32.
33.
Melissa S. Camp MD MPH Suzanne B. Coopey MD Rong Tang MD Amy Colwell MD Michelle Specht MD Rachel A. Greenup MD MPH Michele A. Gadd MD Elena Brachtel MD William G. Austen Jr MD Barbara L. Smith MD PhD 《The breast journal》2014,20(4):402-407
We evaluated management of positive sub‐areolar/nipple duct margins in nipple‐sparing mastectomies (NSM) at our institution. Retrospective chart review of all NSM from January 2007 to April 2012 was performed and patient, tumor, and treatment information was collected. Sub‐areolar/nipple duct margins included ductal tissue from within the nipple. Of 438 NSM, 22 (5%) had positive sub‐areolar/nipple duct margins; 21 of 220 cancer‐bearing breasts (10%) and 1 of 218 prophylactic mastectomies (0.5%). Positive margins included four with invasive lobular carcinoma and 18 with ductal carcinoma in situ (DCIS). Management included removal of eight nipples and nine nipple areola complexes (NAC). Four of 17 nipple/NAC specimens had evidence of residual DCIS and none had residual invasive cancer. The majority of nipple/NAC specimens excised for a positive margin had no residual malignancy. Future studies are needed to determine the extent of NAC tissue removal required for positive margins. 相似文献
34.
35.
Willie A. S. Vieira Sami J. Michereff Marcos A. de Morais Jr Kevin D. Hyde Marcos P. S. Câmara 《Fungal Diversity》2014,67(1):181-202
Endophytic species of Colletotrichum associated with Mangifera indica (mango) are poorly understood. In this study, Colletotrichum species were isolated from mango in Pernambuco State, Brazil. There were significant differences in isolation frequencies of Colletotrichum species among sites and plant tissues. Mature leaf blades were colonized by most Colletotrichum isolates at the majority of sites. Partial sequences of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) of 97 Colletotrichum isolates were amplified as an initial measure of genetic diversity. Phylogenetic analysis with a subset of 22 isolates were performed based on a multi-locus dataset (ACT, TUB2, CAL, CHS-1, GAPDH, ITS) followed by Apn2/MAT IGS sequence-analysis for isolates within the C. gloeosporioides species complex. Molecular analysis associated with phenotypic characteristics revealed six previously described species [C. asianum, C. cliviae, C. dianesei (syn. C. melanocaulon), C. fructicola, C. karstii and C. tropicale] and one new species. This new species is introduced as C. endomangiferae. All species isolated were pathogenic on mango fruits but varied in their virulence. There was no distribution pattern of species among sites and plant tissues, although C. asianum was the most prevalent species at all sites and in all plant tissues studied. Five previously reported Colletotrichum species causing anthracnose in mango fruits in northeastern Brazil were also recovered as endophytes. 相似文献
36.
37.
Michael P. Sarras Jr. PhD Samantha Mason RN Geoffrey McAllister BS Robert V. Intine PhD 《Wound repair and regeneration》2014,22(5):666-670
We previously reported a zebrafish model of type I diabetes mellitus (DM) that can be used to study the hyperglycemic (HG) and metabolic memory (MM) states within the same fish. Clinically, MM is defined as the persistence of diabetic complications even after glycemic control is pharmacologically achieved. In our zebrafish model, MM occurs following β‐cell regeneration, which returns fish to euglycemia. During HG, fish acquire tissue deficits reflective of the complications seen in patients with DM and these deficits persist after fish return to euglycemia (MM). The unifying mechanism for the induction of diabetic complications involves a cascade of events that is initiated by the HG stimulation of poly‐ADP ribose polymerase enzyme (Parp) activity. Additionally, recent evidence shows that the HG induction of Parp activity stimulates changes in epigenetic mechanisms that correlate with the MM state and the persistence of complications. Here we report that wound‐induced angiogenesis is impaired in DM and remains impaired when fish return to a euglycemic state. Additionally, inhibition of Parp activity prevented the HG‐induced wound angiogenesis deficiency observed. This approach can identify molecular targets that will provide potential new avenues for therapeutic discovery as angiogenesis imbalances are associated with all HG‐damaged tissues. 相似文献
38.
Thomas J. Wilson Aditya S. Pandey William R. Stetler Jr. Matthew C. Davis David A. Giles Neeraj Chaudhary Joseph J. Gemmete B. Gregory Thompson 《Acta neurochirurgica》2014,156(5):855-859
Background
Thromboembolic events represent a clinically significant cause of neurological morbidity during the endovascular management of cerebral aneurysms. We have implemented an anti-thromboembolic regimen consisting of pre- and postoperative dual antiplatelet therapy, as well as postoperative anticoagulation using heparin and dextran. The aims of our study were to examine the effect of this regimen on thromboembolic rates during elective aneurysm coiling, and to elucidate risk factors associated with the development of thromboembolic events in this setting.Methods
We conducted a retrospective review of patients who underwent elective intracranial aneurysm coiling between January 2005 and February 2012. The primary outcome of interest was the occurrence of a clinically significant peri-procedural thromboembolic event. Secondary outcomes included the occurrence of a central nervous system (CNS) or systemic hemorrhage.Results
During the study period, 312 patients underwent elective aneurysm coiling and six (2 %) thromboembolic events occurred; three (1 %) occurred in the group that received the anti-thromboembolic regimen (261 patients) and three (6 %) occurred in the group that did not receive the regimen (51 patients), resulting in a statistically significant difference (P?=?0.024). Both the presence of a hypercoagulable state (P?=?0.014) and the lack of the anti-thromboembolic regimen (P?=?0.043) were significantly associated with the occurrence of a thromboembolic event.Conclusions
This study provides evidence that the regimen described here is safe and reduces thromboembolic complications during elective aneurysm coiling. Ours is likely the most aggressive regimen in the published literature and significantly reduced the rate of thromboembolism without any significant increase hemorrhagic complications. 相似文献39.
The in vitro activity of SK&F 104662, a new glycopeptide antibiotic, against gram-positive bacteria was evaluated. Activity was comparable to those of teicoplanin and vancomycin against most organisms. SK&F 104662 inhibited diphtheroids at concentrations of less than or equal to 0.5 microgram/ml. Addition of human serum to the test medium lowered the inhibitory activity of this glycopeptide against some organisms by as much as eightfold. 相似文献
40.