全文获取类型
收费全文 | 31551篇 |
免费 | 1923篇 |
国内免费 | 158篇 |
专业分类
耳鼻咽喉 | 270篇 |
儿科学 | 458篇 |
妇产科学 | 325篇 |
基础医学 | 4623篇 |
口腔科学 | 934篇 |
临床医学 | 3012篇 |
内科学 | 7511篇 |
皮肤病学 | 456篇 |
神经病学 | 3485篇 |
特种医学 | 1878篇 |
外科学 | 4375篇 |
综合类 | 187篇 |
一般理论 | 11篇 |
预防医学 | 1271篇 |
眼科学 | 596篇 |
药学 | 1728篇 |
中国医学 | 52篇 |
肿瘤学 | 2460篇 |
出版年
2024年 | 28篇 |
2023年 | 265篇 |
2022年 | 441篇 |
2021年 | 820篇 |
2020年 | 509篇 |
2019年 | 710篇 |
2018年 | 798篇 |
2017年 | 616篇 |
2016年 | 876篇 |
2015年 | 997篇 |
2014年 | 1249篇 |
2013年 | 1536篇 |
2012年 | 2507篇 |
2011年 | 2523篇 |
2010年 | 1511篇 |
2009年 | 1355篇 |
2008年 | 2230篇 |
2007年 | 2245篇 |
2006年 | 2153篇 |
2005年 | 2035篇 |
2004年 | 1765篇 |
2003年 | 1677篇 |
2002年 | 1566篇 |
2001年 | 276篇 |
2000年 | 217篇 |
1999年 | 293篇 |
1998年 | 310篇 |
1997年 | 226篇 |
1996年 | 169篇 |
1995年 | 157篇 |
1994年 | 130篇 |
1993年 | 97篇 |
1992年 | 87篇 |
1991年 | 80篇 |
1990年 | 62篇 |
1989年 | 79篇 |
1988年 | 60篇 |
1987年 | 53篇 |
1986年 | 71篇 |
1985年 | 57篇 |
1984年 | 45篇 |
1983年 | 42篇 |
1982年 | 46篇 |
1981年 | 32篇 |
1980年 | 39篇 |
1978年 | 36篇 |
1977年 | 36篇 |
1976年 | 29篇 |
1937年 | 30篇 |
1935年 | 35篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
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
42.
R Dagan D M Fliss M Einhorn M Kraus A Leiberman 《The Pediatric infectious disease journal》1992,11(7):542-546
Prolonged antipseudomonal parenteral antibiotic therapy combined with daily aural toilet has been effective in resolving long standing ear discharge in children with chronic suppurative otitis media. However, such treatment suffered from the disadvantages of prolonged hospitalization. We conducted a prospective study to investigate the feasibility and efficacy of exclusive outpatient treatment of children with chronic suppurative otitis media without cholesteatoma who had failed ototopical/oral antimicrobial therapy. The treatment consisted of daily aural toilet (suction and debridement) and twice daily parenteral ceftazidime (50 mg/kg/dose). Thirty-seven children were included. The duration of discharge from the ear before treatment was 6 to 121 months (median, 30 months). Aerobic cultures yielded Pseudomonas aeruginosa in 97%, often with other organisms. The management and follow-up were performed jointly by otolaryngology and infectious diseases physicians using the hospital ambulatory services. The route of ceftazidime administration (intravenous or intramuscular) was chosen according to the parents' and patients' convenience. Discharge stopped within 3 to 20 days (median, 8 days) in all children but one. Seventy-six percent of the 29 children available for follow-up 12 months after treatment were still free of discharge. Our results demonstrate that a regiment combining daily aural toilet and twice daily parenteral ceftazidime is highly efficacious in resolving ear discharge in children with chronic suppurative otitis media without cholesteatoma and that such a regimen does not require hospitalization. 相似文献
43.
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
44.
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
45.
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
46.
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
47.
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
48.
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
49.
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
50.
Martin Haupt Alexander Kurz Stefan Pollmann Barbara Romero 《Journal of neurology》1992,239(5):248-250
Summary Ninety outpatients with Alzheimer's disease according to ICD-10 diagnostic draft criteria were studied to test the hypothesis that cases with a familial aggregation are different from cases without such an aggregation with respect to cognitive impairment. In all cases the diagnosis of Alzheimer's disease was confirmed by prospective observation within 12 months of initial evaluation. Patients were divided into two groups: one consisting of 23 patients with a familial aggregation, the other consisting of 67 patients without secondary cases among first-degree relatives. By means oft-tests differences in impairment of cognitive functions between the groups were calculated. The results did not yield statistically significant differences between the groups for any of the neuropsychologically investigated cognitive deficits. Thus the hypothesis that the presence of a familial aggregation may lead to a distinct phenotype in Alzheimer's disease was not confirmed. 相似文献