全文获取类型
收费全文 | 30690篇 |
免费 | 2011篇 |
国内免费 | 158篇 |
专业分类
耳鼻咽喉 | 264篇 |
儿科学 | 437篇 |
妇产科学 | 305篇 |
基础医学 | 4583篇 |
口腔科学 | 930篇 |
临床医学 | 2981篇 |
内科学 | 7381篇 |
皮肤病学 | 456篇 |
神经病学 | 3480篇 |
特种医学 | 1857篇 |
外科学 | 4161篇 |
综合类 | 177篇 |
一般理论 | 11篇 |
预防医学 | 1258篇 |
眼科学 | 599篇 |
药学 | 1713篇 |
中国医学 | 52篇 |
肿瘤学 | 2214篇 |
出版年
2024年 | 28篇 |
2023年 | 264篇 |
2022年 | 438篇 |
2021年 | 816篇 |
2020年 | 506篇 |
2019年 | 705篇 |
2018年 | 788篇 |
2017年 | 613篇 |
2016年 | 874篇 |
2015年 | 989篇 |
2014年 | 1241篇 |
2013年 | 1524篇 |
2012年 | 2494篇 |
2011年 | 2507篇 |
2010年 | 1501篇 |
2009年 | 1345篇 |
2008年 | 2205篇 |
2007年 | 2212篇 |
2006年 | 2139篇 |
2005年 | 2008篇 |
2004年 | 1742篇 |
2003年 | 1644篇 |
2002年 | 1535篇 |
2001年 | 257篇 |
2000年 | 190篇 |
1999年 | 273篇 |
1998年 | 304篇 |
1997年 | 224篇 |
1996年 | 164篇 |
1995年 | 150篇 |
1994年 | 122篇 |
1993年 | 87篇 |
1992年 | 60篇 |
1991年 | 60篇 |
1990年 | 39篇 |
1989年 | 57篇 |
1988年 | 36篇 |
1987年 | 31篇 |
1986年 | 33篇 |
1985年 | 31篇 |
1984年 | 28篇 |
1983年 | 34篇 |
1982年 | 34篇 |
1981年 | 28篇 |
1980年 | 26篇 |
1938年 | 24篇 |
1937年 | 30篇 |
1936年 | 25篇 |
1935年 | 35篇 |
1934年 | 22篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Combination of intermittent haemodialysis and high-volume continuous haemofiltration for the treatment of severe metformin-induced lactic acidosis. 总被引:15,自引:2,他引:13
Ulf Panzer Stefan Kluge Georg Kreymann Gunter Wolf 《Nephrology, dialysis, transplantation》2004,19(8):2157-2158
Sir, Metformin has been used for many decades as an effective glucose-loweringmedication in the treatment of type 2 diabetes mellitus. Recentstudies clearly demonstrated that metformin reduced secondarycomplications of diabetes mellitus type 2 without promotingweight gain, which is in contrast to treatment with insulinand/or sulphonylurea [1]. Lactic acidosis is a serious sideeffect observed with metformin treatment and 相似文献
62.
Woltmann Alexander Thannheimer Andreas Hauck Stefan Bhren Volker 《Trauma und Berufskrankheit》2003,5(2):s293-s295
Abdominal infection has the fifth highest incidence of all posttraumatic infections but has the second highest mortality rate with 25%,pneumonia,with 29%, being the only posttraumatic infection that is more frequently lethal.Posttraumatic abdominal sepsis, on the other hand, has a mortality rate of almost 50%.This rate cannot be reduced except by prompt identification of the correct diagnosis of the underlying injury or complication.This means that delayed laparotomy is strikingly detrimental in these patients, with 46% mortality as opposed to 11% in patients who undergo laparotomy promptly. In parallel with this, the mortality of fresh-onset and localized peritonitis is 14%,whereas that of diffuse purulent peritonitis is up to a devastating 42%. 相似文献
63.
Hochstein Paul Heppert Volkmar Grtzner Paul Alfred Matschke Stefan Wentzensen Andreas 《Trauma und Berufskrankheit》2003,5(1):s56-s61
Malunion and nonunion after fracture present many difficulties in trauma surgery. Selection of the best therapy and operative techique requires careful analysis of the complications. Hyperthrophic nonunion of the femur shaft is mostly best treated with locking reamed nails. Significant differences in torsions after nailing can be corrected by repositioning of the distal interlocking screws if recognized sufficiently early. After fracture healing an open rotation osteotomy is necessary; stabilization can be achieved by means of medullary nails or a condylar plate. How a malalignment of the bone axis is corrected depends on the position of a malunion, the functional deficit caused, and the biomechanical demands on the joint. Condylar plates can often solve the problems in this region. There are also guidelines for ¶the treatment of atrophic and infected nonunions (recommended procedures are ¶aggressive debridement, autologous cancellous bone graft, and biological osteosynthesis), but the treatment of individual cases requires a exhaustive knowledge of and experience in this special field. It is quite common for even well-established procedures to fail. When the bone is biologically reduced and this is the reason for malunion newly developed techniques of internal fixation can be applied. The less invasive stabilization system (LISS), combined with autologous cancellous bone grafting if necessary, can result in healing even in a worst-case scenario. 相似文献
64.
Paul J Drinka Peggy Krause Lori Nest Brian M Goodman Stefan Gravenstein 《Infection control and hospital epidemiology》2003,24(11):872-874
Influenza A was cultured in 62 double rooms. The roommate was infected in 12 (19.4%). During 3,294 resident-seasons, influenza was cultured in 208 single rooms (6.3%). Those who lived in double rooms with a culture-positive roommate had a 3.07 relative risk (CI95, 1.61-5.78) of acquiring influenza. 相似文献
65.
Potential advantages of paediatric day-surgery are cost saving, improved utilization of staff and hospital facilities, and reduction of stress for the paediatric patient and their family. A successful programme requires careful case selection, full operating and anaesthetic facilities and good follow-up. Current practice is reviewed with regard to initial assessment, preparation for surgery and overall management during the day admission. To provide information on how patients and their parents experience essential aspects of daycare paediatric surgery, a questionnaire-based study on parental satisfaction of paediatric day-surgery was performed. Most children were back to normal, within a few days. Recovery from paediatric day-surgery was rapid and the overall level of parent satisfaction was high. 相似文献
66.
Parvalbumin 3 is an Abundant Ca2+ Buffer in Hair Cells 总被引:3,自引:0,他引:3
Stefan Heller Andrea M. Bell Charlotte S. Denis Yong Choe A.J. Hudspeth 《Journal of the Association for Research in Otolaryngology》2002,3(4):488-498
Ca2+ signaling serves distinct purposes in different parts of a hair cell. The Ca2+ concentration in stereocilia regulates
adaptation and, through rapid transduction-channel reclosure, underlies amplification of mechanical signals. In presynaptic
active zones, Ca2+ mediates the exocytotic release of afferent neurotransmitter. At efferent synapses, Ca2+ activates the
K+ channels that dominate the inhibitory postsynaptic potential. A copious supply of diffusible protein buffer isolates the
three signals by restricting the spread of free Ca2+ and limiting the duration of its action. Using cDNA subtraction and a
gene expression assay based on in situ hybridization, we detected abundant expression of mRNAs encoding the Ca2+ buffer parvalbumin
3 in bullfrog saccular and chicken cochlear hair cells. We cloned cDNAs encoding this protein from the corresponding inner-ear
libraries and raised antisera against recombinant bullfrog parvalbumin 3. Immunohistochemical labeling indicated that parvalbumin
3 is a prominent Ca2+-binding protein in the compact, cylindrical hair cells of the bullfrog's sacculus, and occurs as well
in the narrow, peanut-shaped hair cells of that organ. Using quantitative Western blot analysis, we ascertained that the concentration
of parvalbumin 3 in saccular hair cells is approximately 3 mM. Parvalbumin 3 is therefore a significant mobile Ca2+ buffer,
and perhaps the dominant buffer, in many types of hair cell. Moreover, parvalbumin 3 provides an early marker for developing
hair cells in the frog, chicken, and zebrafish. 相似文献
67.
Monocyte adhesion molecule expression in interstitial inflammation in patients with renal failure. 总被引:2,自引:0,他引:2
Elham Dadfar Joachim Lundahl Stefan H Jacobson 《Nephrology, dialysis, transplantation》2004,19(3):614-622
BACKGROUND: Patients with renal failure have an increased susceptibility to infections. We therefore studied the recruitment of monocytes and their expression of adhesion molecules CD11b and CD62L at the site of interstitial inflammation in patients with renal failure. Furthermore, we studied if the capacity of monocytes to up-regulate CD11b in interstitial inflammation was determined by the interstitial concentration of chemotactic factors. METHODS: Three intensities of interstitial inflammation (0, intermediate and intense) were established in skin blister chambers. Leukocyte count, CD11b/CD62L expression, monocyte chemotactic protein-1 (MCP-1) and blister activity in terms of CD11b mobilization were determined. RESULTS: The CD62L expression on monocytes was lower in the peripheral circulation in patients with renal failure compared with healthy subjects (P<0.005 and P<0.001). At the site of interstitial inflammation patients had a higher expression of CD62L (intermediate, P<0.05; intense, P<0.005). Furthermore, monocytes from patients had an impaired capacity to mobilize CD11b both in the peripheral circulation (P<0.005) and at the intermediate and intense sites of interstitial inflammation (P<0.005 and P<0.001, respectively) compared with cells collected from healthy subjects. We incubated monocytes in blister exudates, in order to explore whether this phenomenon is caused by cellular factors and/or to the interstitial concentration of chemotactic mediators. The expression of CD11b on monocytes from healthy blood donors incubated in blister exudates from either patients or healthy subjects in vitro was similar. The interstitial concentration of MCP-1 at the site of intermediate inflammation was significantly lower in patients with renal failure compared with the corresponding blister exudate collected from healthy subjects (P<0.05), but no differences were observed at the site of intense inflammation. Furthermore, neutralizing the action of MCP-1 in blister exudates with monoclonal antibodies did not have any impact on monocyte CD11b expression following incubation in blister exudates. CONCLUSION: These studies indicate that the impaired capacity of monocytes to mobilize CD11b at the site of inflammation in patients with renal failure is more dependent on constitutive cellular factors than the concentration of CD11b mobilizing factors in the interstitium. 相似文献
68.
Stefan Christiansen Rüdiger Autschbach 《European journal of cardio-thoracic surgery》2006,30(4):611-616
Doxorubicin-induced heart failure is a rare but serious illness due to the well-known treatment difficulties. Prevention strategies have not demonstrated the expected success and unfortunately, this specific type of heart failure does not respond to the usual medical therapy as other kinds of heart failure. Therefore, surgical procedures may be necessary in some patients. Cardiac transplantation is performed in most cases but it requires the cure of the neoplastic disease. This usually requires a recurrence-free interval of several years which is associated with a high attrition rate in these patients due to their cardiac disease. Therefore, other conservative and surgical treatment concepts were developed during the last years. This review presents the most common procedures and discusses their efficacy as well as their clinical applicability. 相似文献
69.
T. Hammen F. Kerling M. Schwarz A. Stadlbauer O. Ganslandt B. Keck B. Tomandl A. Dörfler H. Stefan 《European journal of neurology》2006,13(5):482-490
Up to 30% of patients with temporal lobe epilepsy (TLE) remain without remarkable changes in MRI. In this study we investigated the role of (1)H-MR spectroscopy ((1)H-MRS) in lateralizing the affected hemisphere in the mentioned patient group. Twenty-two consecutive patients diagnosed with TLE were investigated by high resolution MRI and (1)H-MRS. We examined the incidence and diagnostic accuracy of temporal metabolite alterations determined by Linear Combination of Model Spectra (L C Model) via water reference. Metabolite values of each hemisphere of TLE patients were compared with healthy controls. Results of metabolite alterations were related to intensive video EEG focus localization. Reduction of N-acetylaspartate + N-acetylaspartyl-glutamate (tNAA) in the affected hemisphere revealed identification in six of nine patients (66%) with unilateral TLE. Group comparison revealed a significant reduction of tNAA (6.1+/-0.8*) in the involved temporal lobe compared with controls (6.67+/-0.4*, P=0.026). Choline levels were significantly increased in the affected hemisphere (1.42+/-0.17*) compared with healthy controls (1.22+/-0.17*, P=0.035). The results of our study show that (1)H-MRS is able to identify the affected hemisphere of MRI negative TLE patients and can be used as an additive tool in multimodal focus localization. 相似文献
70.
A general model is developed for segmenting magnetic resonance images using vector decomposition and probabilfty techniques. Each voxel is assigned fractional volumes of q tissues from p differently weighted images (q ≤ p + 1) in the presence of partial-volume mixing, random noise, and other tissues. Compared wtth the eigenimage method, fewer differently weighted images are needed for segmenting the q tissues, and the contrast-to-noise ratio in the calculated fractional volumes is improved. The model can produce com-posrte tissue-type images similar to that of the probability methods, by comparing the fractional volumes assigned to different tissues on each voxel. A three-tissue (p = 2, q = 3) model is illustrated for segmenting three tissues from dual-echo images. M provides statistical analysis to the algebraic method. A three-compartment phantom is segmented for validation. Two clinical examples are presented. 相似文献