全文获取类型
收费全文 | 26300篇 |
免费 | 1436篇 |
国内免费 | 72篇 |
专业分类
耳鼻咽喉 | 390篇 |
儿科学 | 545篇 |
妇产科学 | 678篇 |
基础医学 | 4622篇 |
口腔科学 | 556篇 |
临床医学 | 2460篇 |
内科学 | 4758篇 |
皮肤病学 | 512篇 |
神经病学 | 2575篇 |
特种医学 | 1360篇 |
外科学 | 3922篇 |
综合类 | 166篇 |
一般理论 | 3篇 |
预防医学 | 1306篇 |
眼科学 | 786篇 |
药学 | 1758篇 |
中国医学 | 67篇 |
肿瘤学 | 1344篇 |
出版年
2022年 | 164篇 |
2021年 | 372篇 |
2020年 | 225篇 |
2019年 | 369篇 |
2018年 | 443篇 |
2017年 | 384篇 |
2016年 | 444篇 |
2015年 | 482篇 |
2014年 | 684篇 |
2013年 | 1003篇 |
2012年 | 1333篇 |
2011年 | 1335篇 |
2010年 | 891篇 |
2009年 | 824篇 |
2008年 | 1310篇 |
2007年 | 1398篇 |
2006年 | 1431篇 |
2005年 | 1455篇 |
2004年 | 1230篇 |
2003年 | 1214篇 |
2002年 | 1202篇 |
2001年 | 339篇 |
2000年 | 309篇 |
1999年 | 318篇 |
1998年 | 303篇 |
1997年 | 228篇 |
1996年 | 214篇 |
1995年 | 221篇 |
1994年 | 183篇 |
1993年 | 168篇 |
1992年 | 195篇 |
1991年 | 187篇 |
1990年 | 165篇 |
1989年 | 128篇 |
1988年 | 125篇 |
1986年 | 122篇 |
1985年 | 124篇 |
1984年 | 137篇 |
1982年 | 144篇 |
1981年 | 126篇 |
1933年 | 165篇 |
1932年 | 155篇 |
1931年 | 138篇 |
1930年 | 157篇 |
1929年 | 129篇 |
1928年 | 138篇 |
1927年 | 125篇 |
1926年 | 129篇 |
1925年 | 130篇 |
1924年 | 136篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
Boerhaave’s syndrome: Primary repair vs. esophageal resection—Case reports and meta-analysis of the literature 总被引:3,自引:0,他引:3
Otto Kollmar M.D. Werner Lindemann M.D. Sven Richter M.D. Ingo Steffen M.D. Georg Pistorius M.D. Martin K. Schilling M.D. 《Journal of gastrointestinal surgery》2003,7(6):726-734
Boerhaave’s syndrome is a life-threatening disease with a high mortality. With regard to the heterogeneity of treatment strategies,
no comparative studies exist and recommendations remain controversial. Seventeen cases of Boerhaave’s syndrome operated on
between 1989 and 2000 at our hospital were reviewed retrospectively to compare the time period between perforation and diagnosis,
and the morbidity and mortality among the different treatment options. In addition, we conducted a meta-analysis of the literature
including all series containing five or more patients and compared the findings with our own data. Our patients with a perforation
history of less than 12 hours showed significantly fewer signs of sepsis compared to patients with a history of more than
12 hours. In a comparison of patients with primary repair vs. patients treated with esophageal resection or an exclusion operation,
no differences were found. In the literature, patients with a long period of perforation (more than 24 hours) were treated
more often with an esophageal resection than patients with primary repair. In cases of Boerhaave’s syndrome, primary suturing
of the esophageal perforation should be reserved only for those patients presenting within 12 hours after perforation. In
all other cases, depending on the extent of the tissue damage, a two-stage esophageal resection with cervical esophagostomy
and gastrostomy is recommended as the safest treatment. 相似文献
32.
Catarina Gonzalez da Silva Karl Magnus Petersson Luís Faísca Martin Ingvar Alexandra Reis 《Journal of clinical and experimental neuropsychology》2004,26(2):266-277
Semantic verbal fluency tasks are commonly used in neuropsychological assessment. Investigations of the influence of level of literacy have not yielded consistent results in the literature. This prompted us to investigate the ecological relevance of task specifics, in particular, the choice of semantic criteria used. Two groups of literate and illiterate subjects were compared on two verbal fluency tasks using different semantic criteria. The performance on a food criterion (supermarket fluency task), considered more ecologically relevant for the two literacy groups, and an animal criterion (animal fluency task) were compared. The data were analysed using both quantitative and qualitative measures. The quantitative analysis indicated that the two literacy groups performed equally well on the supermarket fluency task. In contrast, results differed significantly during the animal fluency task. The qualitative analyses indicated differences between groups related to the strategies used, especially with respect to the animal fluency task. The overall results suggest that there is not a substantial difference between literate and illiterate subjects related to the fundamental workings of semantic memory. However, there is indication that the content of semantic memory reflects differences in shared cultural background--in other words, formal education--, as indicated by the significant interaction between level of literacy and semantic criterion. 相似文献
33.
34.
Trauma und Berufskrankheit - Zusammenfassung Diese Arbeit beschäftigt sich mit der Häufigkeit, dem Entstehungsmechanismus und der Behandlung von Bizepssehnenrupturen. Veränderte... 相似文献
35.
Samuel B Adams Paul R Herz Debra L Stamper Mark J Roberts Stephane Bourquin Nirlep A Patel Karl Schneider Scott D Martin Sonya Shortkroff James G Fujimoto Mark E Brezinski 《Journal of orthopaedic research》2006,24(4):708-715
The objective of this study was to develop and verify a new technique for monitoring the progression of osteoarthritis (OA) by combining a rat model with the imaging modality optical coherence tomography (OCT). Time-sequential, in vivo, OCT imaging was performed on the left femoral condyles of 12 Wistar rats following sodium-iodoacetic acid-induced OA progression. The right femoral condyles (untreated) were also imaged and served as controls. Imaging was performed on days 0, 10, 20, 30, and 60 with an OCT system capable of acquiring images at four frames per second and an axial resolution of 5 microm. Progressive changes were analyzed using an OA scoring system. OCT successfully identified progressive cartilage degeneration as well as alteration of the cartilage/bone interface. Significant changes to both of these structures were observed in the sodium-iodoacetic acid-injected condyles. Structural changes detected with OCT were confirmed histologically. OCT in combination with a well-known model used in arthritis research represents a powerful tool for following degenerative joint disease progression in a given animal by detecting changes to the cartilage/bone interface and articular cartilage. 相似文献
36.
Karl Fournier MD ; Catherine Tavera PhD ; Paul Brazeau PhD ; Thierry Abribat DVM PhD 《Wound repair and regeneration》1996,4(2):252-258
Proteases that reduce insulin-like growth factor binding protein-3 affinity for insulin-like growth factor-I have been found in various biological fluids from human beings and rats. The aim of this study was to assess the local and systemic role of insulin-like growth factor binding protein-3 proteases in the course of wound healing. Six rats had polyvinyl alcohol sponges implanted subcutaneously. Wound fluid and serum were collected 3 days after wounding. Gel filtration experiments showed that insulin-like growth factor-I was present as a 150 kDa complex in both serum and wound fluid. However, insulin-like growth factor binding protein-3 measured by Western ligand blotting was virtually absent in wound fluid. Co-incubation of serum and wound fluid resulted in an ethylenediamine tetraacetic acid-inhibitable degradation of serum insulin-like growth factor binding protein-3, suggesting the presence of an insulin-like growth factor binding protein-3 degrading activity in wound fluid. Incubation of ((125)I)-labeled insulin-like growth factor binding protein-3 in wound fluid and serum showed a rapid and time-dependent proteolysis of insulin-like growth factor binding protein-3 in wound fluid with metabolites similar to those generated by human term pregnant serum. No sign of insulin-like growth factor binding protein-3 degrading activity was observed in rat-serum. In conclusion, there is an insulin-like growth factor binding protein-3 proteolytic activity in wound fluid, and it is hypothesized that this activity results in a localized increase in insulin-like growth factor-I bioactivity. 相似文献
37.
Several areas related to the use of telescopes in low vision are reviewed. These include: contrast sensitivity function; eccentric viewing through a telescope; field of view; telescope used in reverse; and IOL-spectacle lens telescopic systems. Experimental data are included to support selected clinical observations routinely made by low vision clinicians. 相似文献
38.
An extrachromosomal nucleic acid element was detected in high-molecular-weight DNA preparations formBabesia equi merozoites. This extrachromosomal element was shown to be DNA rather than RNA and had an apparent fragment size of about 9 kilobasepairs (kb). Hybridization experiments using purified 9-kb DNA as a probe revealed sequence homologies with extrachromosomal DNA from two otherBabesia species. 相似文献
39.
Otto Robertsson Kaj Knutson Stefan Lewold Stuart Goodman Lars Lidgren 《Acta orthopaedica》1997,68(6):545-553
The Swedish Knee Arthroplasty Register has data on 4, 381 primary operations performed 1985-1995 for rheumatoid arthritis. Of these, 192 were performed with unicompartmental prostheses and 4143 with tricompartmental. 77% were women and the mean age was 66 years. There were 126 first, 20 second, and 1 third revision in tricompartmental arthroplasties, mainly for loosening, infection and patellar problems. There were 38 first, 3 second, and 1 third revision in unicompartmental arthroplasties, mainly for progression of RA and loosening .
Cumulative revision rates (Kaplan-Meier) were calculated. Tricompartmental knees had a 10-year cumulative revision rate of 5% and uni-knees 25%. Patients treated before 1990, men and patients younger than 55 had higher revision rates than patients treated after 1990, women and older patients, respectively. Cemented tibial components resulted in lower revision rates than uncemented ones. There was no significant difference in revision rates between patellar replaced and unreplaced knees or between the 9 commonest implant types. 相似文献
Cumulative revision rates (Kaplan-Meier) were calculated. Tricompartmental knees had a 10-year cumulative revision rate of 5% and uni-knees 25%. Patients treated before 1990, men and patients younger than 55 had higher revision rates than patients treated after 1990, women and older patients, respectively. Cemented tibial components resulted in lower revision rates than uncemented ones. There was no significant difference in revision rates between patellar replaced and unreplaced knees or between the 9 commonest implant types. 相似文献
40.
In the conclusion of this series of reports, the application of 31P/2H NMR to investigate the pathophysiology of sepsis in rat hindlimb muscle is demonstrated. Sepsis decreased muscle [PCr] by 18%, 18 +/- 4 SD vs 22 +/- 4 SD mmol/kg tissue wet wt (P = 0.01) in control rats but [ATP] was unchanged, 6 mmol/kg tissue wet wt (P = 0.2). The derived free cytosolic [ADP] in the two groups was similar, [ADP]septic = 0.023 +/- 0.004 SD and [ADP]control = 0.021 +/- 0.003 SD mmol/kg tissue wet wt, and not statistically different (P = 0.14). Likewise [Pi] in the septic and control groups was not statistically different, [Pi]septic = 1.1 +/- 0.5 SD and [Pi]control = 1.2 +/- 0.4 SD mmol/kg tissue wet wt (P = 0.2). Septic rats presented the symptom of respiratory alkalosis evidenced by elevated blood pH. Sepsis decreased muscle blood flow by 33%, P = 0.003, but examination of individual subjects did not demonstrate a correlation with the reduction in [PCr]. Thus, a metabolic energy deficit caused by cellular ischemia/hypoxia is not a likely cause of cellular abnormality in rat hindlimb muscle during sepsis. 相似文献