全文获取类型
收费全文 | 846篇 |
免费 | 42篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 9篇 |
妇产科学 | 4篇 |
基础医学 | 73篇 |
口腔科学 | 5篇 |
临床医学 | 49篇 |
内科学 | 168篇 |
皮肤病学 | 16篇 |
神经病学 | 201篇 |
特种医学 | 64篇 |
外科学 | 237篇 |
综合类 | 4篇 |
预防医学 | 14篇 |
眼科学 | 4篇 |
药学 | 39篇 |
肿瘤学 | 9篇 |
出版年
2020年 | 7篇 |
2017年 | 9篇 |
2016年 | 7篇 |
2015年 | 9篇 |
2014年 | 15篇 |
2013年 | 12篇 |
2012年 | 22篇 |
2011年 | 12篇 |
2010年 | 8篇 |
2009年 | 17篇 |
2008年 | 15篇 |
2007年 | 22篇 |
2006年 | 14篇 |
2005年 | 22篇 |
2004年 | 19篇 |
2003年 | 25篇 |
2002年 | 27篇 |
2001年 | 33篇 |
2000年 | 37篇 |
1999年 | 42篇 |
1998年 | 26篇 |
1997年 | 23篇 |
1996年 | 25篇 |
1995年 | 19篇 |
1994年 | 28篇 |
1993年 | 15篇 |
1992年 | 26篇 |
1991年 | 18篇 |
1990年 | 27篇 |
1989年 | 20篇 |
1988年 | 20篇 |
1987年 | 18篇 |
1986年 | 24篇 |
1985年 | 17篇 |
1984年 | 8篇 |
1982年 | 8篇 |
1981年 | 8篇 |
1980年 | 13篇 |
1979年 | 10篇 |
1978年 | 8篇 |
1977年 | 8篇 |
1976年 | 8篇 |
1975年 | 8篇 |
1974年 | 15篇 |
1973年 | 7篇 |
1972年 | 7篇 |
1971年 | 13篇 |
1970年 | 13篇 |
1969年 | 9篇 |
1968年 | 11篇 |
排序方式: 共有902条查询结果,搜索用时 0 毫秒
51.
52.
Eine faktorielle Studie von 6 Interventionen zur Vermeidung von Übelkeit und Erbrechen nach Narkosen
Apfel CC Bacher A Biedler A Danner K Danzeisen O Eberhart LH Forst H Fritz G Hergert M Frings G Goebel A Hopf HB Kerger H Kranke P Lange M Mertzlufft F Motsch J Paura A Roewer N Schneider E Stoecklein K Wermelt J Zernak C 《Der Anaesthesist》2005,54(3):201-209
BACKGROUND: Untreated, one third of patients who undergo surgery will have postoperative nausea and vomiting. Although many trials have been conducted, the relative benefits of prophylactic antiemetic interventions given alone or in combination remain unknown.METHODS: In a randomized, controlled trial of factorial design, 5,199 patients at high risk for postoperative nausea and vomiting were randomly assigned to 1 of 64 possible combinations of 6 prophylactic interventions: 1) 4 mg of ondansetron or no ondansetron; 2) 4 mg of dexamethasone or no dexamethasone; 3) 1.25 mg of droperidol or no droperidol; 4) propofol or a volatile anesthetic; 5) nitrogen or nitrous oxide; 6) remifentanil or fentanyl. The primary aim parameter was nausea and vomiting within 24 h after surgery, which was evaluated blindly.RESULTS: Ondansetron, dexamethasone, and droperidol each reduced the risk of postoperative nausea and vomiting by about 26%, propofol reduced the risk by 19%, and nitrogen by 12%. The risk reduction with both of these agents (i.e., total intravenous anesthesia) was thus similar to that observed with each of the antiemetics alone. All the interventions acted independently of each other and independently of the patients' baseline risk. Consequently, the relative risks associated with the combined interventions could be estimated by multiplying the relative risks associated with each intervention. However, absolute risk reduction was a critical function of patients' baseline risk.CONCLUSIONS: Because antiemetic interventions are similarly effective and act independently, the safest or least expensive should be used first. Prophylaxis is rarely warranted in low-risk patients, moderate-risk patients may benefit from a single intervention, and multiple interventions should be reserved for high-risk patients. 相似文献
53.
A. Hopf 《Archives of orthopaedic and trauma surgery》1955,47(2):227-241
Zusammenfassung Anwendungsweise und Anzeigestellung für den Gebrauch der Kopfklammer nach Crutchfield bei Halswirbelverletzungen werden an Hand von Beispielen beschrieben. Gegenüber dem Dauerzug mittels der Glissonschlinge hat die Crutchfield-Klammer den Vorteil einer weit besseren Verträglichkeit und Ruhigstellung, sowie Essenserleichterung. Ja nach der Höhe der vorliegenden Verletzung werden verschieden große Zuggewichte benötigt. Die Sicherung des erzielten Korrekturergebnisses erfolgt in der Regel durch nachfolgenden Schanzschen Watteverband, wobei ältere Personen zur späteren Wiederkehr der Wirbelverschiebung infolge schlechterer Regenerationsbedingungen neigen. Weitere Anwendungsbereiche der Crutchfield-Klammer sind zerstörende Prozesse im Bereiche der Halswirbelsäule, die eine Dauerzugbehandlung über Monate erfordern und schwere Skoliosen mit Lähmungserscheinungen zur Dauerzugsvorbereitung für die Laminektomie.Wegen der einfachen Technik der Anwendung und der Zuverlässigkeit ist die Crutchfield-Klammer der weit weniger leistungsfähigen Glissonschlingenextension vorzuziehen.Mit 16 Textabbildungen (32 Einzelbilder). 相似文献
54.
55.
Summary This report deals with two patients, brother and sister, suffering from spastic paraplegia. Onset of the disease was at 46 and 51 years of age, respectively. The outstanding clinical features were a slowly progressive course of the disease and an overall slight to moderate impairment of motility in spite of the long duration of the disease of more than 8 to 10 years. The family history failed to reveal any other affected members and we therefore concluded that the disease was inherited by recessive mode. Our cases belong to the adult form of spastic paraplegia of Strümpell and Haldane. We agree on Becker's suggestion stating that this adult form represents a genetically independent type. 相似文献
56.
Martinez-Trujillo JC Tsotsos JK Simine E Pomplun M Wildes R Treue S Heinze HJ Hopf JM 《Neuroreport》2005,16(5):435-438
Cortical area MT/V5 in the human occipito-temporal cortex is activated by visual motion. In this study, we use functional imaging to demonstrate that a subregion of MT/V5 is more strongly activated by unidirectional motion with speed gradients than by other motion patterns. Our results suggest that like the monkey homolog middle temporal area (MT), human MT/V5 contains neurons selective for the processing of speed gradients. Such neurons may constitute an intermediate stage of processing between neurons selective for the average speed of unidirectional motion and neurons selective for different combinations of speed gradient and different motion directions such as expanding optical flow patterns. 相似文献
57.
Siegel AM Bertalanffy H Dichgans JJ Elger CE Hopf H Hopf N Keidel M Kleider A Nowak G Pfeiffer RA Schramm J Spuck S Stefan H Sure U Baumann CR Rouleau GA Verlaan DJ Andermann E Andermann F 《Der Nervenarzt》2005,76(2):175-180
In 1928, Hugo Friedrich Kufs reported on a family with cerebral, retinal, and cutaneous cavernous malformations. Since then, more than 300 families with inherited cavernous malformations have been reported. Genetic studies showed three loci, on chromosomes 7q21-q22 (with the gene CCM1), 7p15-p13 (CCM2), and 3q25.2-q27 (CCM3). The gene product of CCM1 is Krit 1 (Krev interaction trapped 1), a protein interacting with angiogenesis by various mechanisms. Recently, CCM2 has also been identified; its product is a protein which might have a function similar to that of Krit 1. However, the CCM3 gene has still not been found. In this study, we present clinical and genetic findings on 15 German families. 相似文献
58.
Efficiency of low-intensity pulsed ultrasound on distraction osteogenesis in case of delayed callotasis -- clinical results 总被引:1,自引:0,他引:1
Esenwein SA Dudda M Pommer A Hopf KF Kutscha-Lissberg F Muhr G 《Zentralblatt für Chirurgie》2004,129(5):413-420
AIM: Low-intensity pulsed ultrasound has been proven to accelerate fracture healing both clinically and experimentally. In this study the influence of low-intensity pulsed ultrasound during distraction-osteogenesis in case of delayed callotasis was investigated. METHOD: 20 patients could be included in this study. 16 patients initially were treated because of fractures of the lower leg, 2 because of fractures of the femur with resulting shortening of the afflicted limb. One patient suffered from chronic osteitis at the thigh and one from chronic osteitis at the upper arm without previous trauma. Because of delayed callotasis an adjunctive ultrasound treatment device was transcutaneously applied (frequency 1.5 MHz, signal burst width 200 microseconds, signal repetition frequency 1.0 kHz, intensity 30 mW/cm (2)) with the transducer placed at the distraction zone for 20 minutes daily. In all cases in-home treatment was performed. Evaluation was done by radiographic and sonographic controls of the distraction zone during examination of all patients at the outpatients' department every 3-4 weeks. RESULTS: Progress of callotasis was achieved in 15 out of 20 patients. Patients who were smokers during ultrasound therapy showed lower healing rates than those who never smoked. 2 patients suffering from osteitis of the tibia and missing callotasis had to be amputated. 3 other patients needed additional operative treatment including cancellous bone grafts because of missing new bone formation. Negative effects of low-intensity pulsed ultrasound during therapy could not be detected. CONCLUSION: We conclude that ultrasound treatment can accelerate bone maturation and formation in distraction osteogenesis, sometimes even in states of poor callotasis. It may provide a method of great promise in cases where delayed bone formation during distraction osteogenesis occurs. 相似文献
59.
AIM: Judgment of factors concerning the indication for the implantation of an artificial disc endoprosthesis, the rating of this operation and biomechanical considerations. METHOD: Presentation of the indication and the value of a new operative concept in comparison to a so-called dynamic stabilization procedure (Dynesys' method). Indications for the operation are: unsuccessful, orthopedic conservative treatment for > 6 months, segmental pain, age < 45 years, evidence of an MRI demonstrable mono- or bisegmental disc degeneration with or without disc prolabation, exclusion of psychogenic disease and positive preoperative, diagnostic measures such as facet joint infiltration and discography. RESULTS: In an earlier investigation the efficacy of the Link method was demonstrated as shown by the reduction of the analgesic use, the angle of the lumbar lordosis (L1-S1) increased from 35.6 degrees to 42.6 degrees (20.2 %), the segmental angle from 19 degrees to 30 degrees (57.5 %). The new investigation using the Aesculap endoprosthesis resulted in a change of the angle of lumbar lordosis from 35.4 degrees to 45.4 degrees (25.4 %) and a change of the segmental angle from 17.3 degrees to 29.1 degrees (57.6 %). This method is a real endoprosthetic instrumentation in the field of spinal surgery. CONCLUSION: In younger patients with mono- or bisegmental disc degeneration there is an indication for the implantation of a disc endoprosthesis. A facet joint arthrosis and an age over 45 years are contraindications for the operation. The indication in patients with a classic failed back surgery syndrome is still unclear, the improvement of the instrumentation and a further adaptation of the systems to the known biomechanics of the lumbar spine are mandatory as is an intensive discussion of the operative procedure in the case of revision operations. The Dynesys method, with the inherent danger of segmental kyphozitation, a published, significant revision quota combined with a reduction of motility, does not fulfill this criterion. 相似文献
60.
The (dis-)advantages of preoperative chemoradiation in patients with esophageal cancer (EC) are still controversial as data are lacking showing a clear cut benefit. Therefore, data of neoadjuvant therapy of our hospital have been analyzed.Since 1994 102 patients with an EC (33 % adenocarcinoma, 67 % squamous cell cancer, scc) were operated after receiving preoperative chemoradiation (36 Gy radiation, 1.8 Gy/day for 4 weeks, 500 mg/m (2) 5-FU for 4 weeks and 20 mg/m (2) Cisplatin, day 1-5, week 1 and 4). Operation was performed usually 8-10 weeks after treatment start.In 11.7 % of patients with an adenocarcinoma a complete pathological response (CR, pT0N0M0) was observed and a pT0 stage in 20.6 %. 38.2 % of these patients were staged as pN0. Postoperative morbidity was observed in 66 % (anastomotic leakage in 20 %, recurrent nerve palsy in 23 %). In-hospital mortality was 5.9 %. 5-year survival was calculated as 30.5 %, in patients wit a CR 66 %.26.5 % of patients with a scc revealed a CR. However no effect at all was observed in 32 % of these patients. 56 % were staged as pN0. Postoperative morbidity was observed in 87 % (anastomotic leakage in 16 %, recurrent nerve palsy in 32 %). In-hospital mortality was 11.8 %. 5-year survival was calculated as 19.2 %, in patients with a CR 45 %. The impact of pN stage was significant (p = 0.0052).These results underline the benefit of neoadjuvant therapy in patients with a CR. Further on, a pN0 stage is an important prognostic indicator. However, it remains open, whether neoadjuvant therapy leads to a downstaging of lymph node involvement, as histological confirmation in clinically positive lymph node is seldom performed prospectively. 相似文献