全文获取类型
收费全文 | 32639篇 |
免费 | 2050篇 |
国内免费 | 158篇 |
专业分类
耳鼻咽喉 | 270篇 |
儿科学 | 490篇 |
妇产科学 | 341篇 |
基础医学 | 4820篇 |
口腔科学 | 957篇 |
临床医学 | 3117篇 |
内科学 | 7818篇 |
皮肤病学 | 470篇 |
神经病学 | 3741篇 |
特种医学 | 1887篇 |
外科学 | 4443篇 |
综合类 | 204篇 |
一般理论 | 11篇 |
预防医学 | 1523篇 |
眼科学 | 603篇 |
药学 | 1814篇 |
中国医学 | 52篇 |
肿瘤学 | 2286篇 |
出版年
2023年 | 269篇 |
2022年 | 449篇 |
2021年 | 839篇 |
2020年 | 514篇 |
2019年 | 718篇 |
2018年 | 813篇 |
2017年 | 643篇 |
2016年 | 893篇 |
2015年 | 1018篇 |
2014年 | 1273篇 |
2013年 | 1582篇 |
2012年 | 2554篇 |
2011年 | 2586篇 |
2010年 | 1541篇 |
2009年 | 1390篇 |
2008年 | 2277篇 |
2007年 | 2288篇 |
2006年 | 2212篇 |
2005年 | 2099篇 |
2004年 | 1822篇 |
2003年 | 1715篇 |
2002年 | 1605篇 |
2001年 | 336篇 |
2000年 | 244篇 |
1999年 | 336篇 |
1998年 | 323篇 |
1997年 | 243篇 |
1996年 | 184篇 |
1995年 | 169篇 |
1994年 | 134篇 |
1993年 | 95篇 |
1992年 | 106篇 |
1991年 | 112篇 |
1990年 | 80篇 |
1989年 | 86篇 |
1988年 | 74篇 |
1987年 | 61篇 |
1986年 | 65篇 |
1985年 | 75篇 |
1984年 | 69篇 |
1983年 | 74篇 |
1982年 | 58篇 |
1981年 | 49篇 |
1980年 | 43篇 |
1979年 | 38篇 |
1978年 | 39篇 |
1976年 | 37篇 |
1975年 | 36篇 |
1974年 | 46篇 |
1935年 | 35篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Intracranial Angioplasty and Stenting in the Awake Patient 总被引:1,自引:0,他引:1
Alex Abou-Chebl MD Derk W. Krieger MD Christopher T. Bajzer MD Jay S. Yadav MD FACC 《Journal of neuroimaging》2006,16(3):216-223
BACKGROUND AND PURPOSE: Endovascular treatment for intracranial atherosclerosis is evolving, but complications remain an issue. Most interventions are performed under general anesthesia, preventing intraprocedural clinical evaluations. We describe our approach to intracranial angioplasty and stenting, using local rather than general anesthesia, and intraprocedural neurological assessment. METHODS: We prospectively collected procedural and outcome information on all patients undergoing intracranial angioplasty and stenting. Patients underwent interventions under local anesthesia with mild intravenous sedation or analgesia only if needed. Intraoperative neurological evaluations were performed, and symptomatology was used to guide the interventional technique. RESULTS: Forty-eight arteries in 40 patients with a mean age of 65.2 years were treated. Thirty-two anterior and 16 posterior circulation segments were treated. Technical success was achieved in 100% of patients with reduction of the mean pretreatment stenosis from 85 +/- 8.6% to 7 +/- 10.1%. Stents were deployed in 40 segments; five patients were treated with drug-eluting stents. The cobalt-chromium coronary stents were the easiest to deliver. Thirty-seven patients were treated under local anesthesia and, of those, 61.4% experienced intraprocedural symptoms that led to some alteration of the interventional technique. Headache was the most common symptom, and, when persistent, it heralded the occurrence of subarachnoid hemorrhage. There were seven total neurological complications, but only five (10.5%) led to permanent morbidity (4 strokes) or mortality (1 death). CONCLUSIONS: Intracranial angioplasty and stenting can be successfully performed using coronary techniques and equipment including drug-eluting stents. Local anesthesia permits neurological evaluations and often leads to the adjustment of the interventional technique, potentially making the procedure safer. 相似文献
52.
Mapping scores onto stages: mini-mental state examination and clinical dementia rating. 总被引:6,自引:0,他引:6
Robert Perneczky Stefan Wagenpfeil Katja Komossa Timo Grimmer Janine Diehl Alexander Kurz 《The American journal of geriatric psychiatry》2006,14(2):139-144
OBJECTIVE: Although the clinical course of Alzheimer disease (AD) is gradual, it is useful for a number of reasons to distinguish between different levels of severity. The Clinical Dementia Rating (CDR) has demonstrated high validity and reliability for this purpose, but it requires a considerable amount of data to be collected both from the patient and from an informant. In the present study, the authors mapped Mini-Mental State Examination (MMSE) scores onto CDR categories to determine how well the MMSE performs as a surrogate of the CDR as a timesaving method of staging dementia. METHOD: Eight hundred sixty-three probands, including 524 patients with probable AD, 92 patients with questionable dementia, and 247 with memory complaints but no objective cognitive impairment, were included. Cutoff scores were identified on one-half of the sample using a receiver operating characteristic analysis. The cutoff values were then applied to the other half of the sample, and the agreement between MMSE score ranges and CDR stages was determined by calculating Cohen's kappa. RESULTS: The MMSE discriminated well between CDR stages 0.5, 1, 2, and 3 but performed poorly in the separation between CDR stages zero and 0.5. The MMSE ranges were 30 for no, 26-29 for questionable, 21-25 for mild, 11-20 for moderate, and 0-10 for severe dementia. Substantial agreement between the two instruments was obtained for the categories mild (kappa=0.62, p<0.001, N=115), moderate (kappa=0.69, p<0.001, N=114), and severe dementia (kappa=0.76, p<0.001, N=39), whereas the agreement was moderate for no (kappa=0.44, p<0.001, N=120) and only fair for questionable dementia (kappa=0.28, p<0.001, N=42). CONCLUSION: The MMSE can be used as a surrogate measure for the CDR for the staging of dementia in AD. 相似文献
53.
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
54.
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
55.
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
56.
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
57.
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
58.
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
59.
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
60.
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