首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   15166篇
  免费   590篇
  国内免费   31篇
耳鼻咽喉   175篇
儿科学   367篇
妇产科学   381篇
基础医学   2586篇
口腔科学   299篇
临床医学   1060篇
内科学   2560篇
皮肤病学   433篇
神经病学   1375篇
特种医学   607篇
外科学   2400篇
综合类   61篇
一般理论   11篇
预防医学   1218篇
眼科学   294篇
药学   948篇
中国医学   31篇
肿瘤学   981篇
  2022年   90篇
  2021年   183篇
  2020年   125篇
  2019年   180篇
  2018年   238篇
  2017年   215篇
  2016年   222篇
  2015年   279篇
  2014年   279篇
  2013年   511篇
  2012年   697篇
  2011年   702篇
  2010年   452篇
  2009年   393篇
  2008年   715篇
  2007年   734篇
  2006年   712篇
  2005年   758篇
  2004年   762篇
  2003年   679篇
  2002年   752篇
  2001年   282篇
  2000年   284篇
  1999年   248篇
  1998年   152篇
  1997年   152篇
  1996年   143篇
  1995年   135篇
  1994年   131篇
  1993年   140篇
  1992年   188篇
  1991年   135篇
  1990年   167篇
  1989年   206篇
  1988年   166篇
  1987年   175篇
  1986年   135篇
  1985年   175篇
  1984年   141篇
  1983年   144篇
  1982年   101篇
  1981年   144篇
  1980年   132篇
  1979年   130篇
  1978年   107篇
  1977年   122篇
  1976年   85篇
  1975年   87篇
  1974年   60篇
  1973年   65篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Zusammenfassung Probleml?sungsstrategien zu perioperativen Prophylaxema?nahmen umfassen mehr Studienarten als Tierexperimente und kontrollierte klinische Studien. Dabei verhelfen Methoden der kognitiven Psychologie und künstlichen Intelligenz zu neuen Verfahren, um kontroverse Standpunkte in der klinischen Versorgung zu formalisieren. Der Weg vom Tierexperiment zur klinischen Indikation, mag mühevoll und beschwerlich sein, aber die Strategie hat sich bei der perioperativen Antihistaminikaprophylaxe als eine neue Form der Prophylaxe schon bew?hrt. Gerade wurde im Refresher Course der ASA, der amerikanischen Gesellschaft für An?sthesie und Intensivmedizin, diese Prophylaxe für alle US-An?sthesisten empfohlen. Mit Unterstützung durch die Deutsche Forschungsgemeinschaft (Lo 199/16-2).  相似文献   
32.
A systematic review on the treatment of giardiasis   总被引:5,自引:0,他引:5  
To assess the efficacy of treatment of parasitological excretion of cysts and trophozoites and symptoms of patients with giardiasis, a systematic review of published randomized clinicial trials was conducted through extensive searches in Medline, Embase and Current Contents from 1966 till 1996 as well as manual reviews of 28 journals. The methodological quality of all trials was assessed by guidelines of the Cochrane Collaboration. Thirty‐one trials were included, only one of which had no serious methodological flaws. The mean score of parasitological examination was 4.8 out of a possible 15. There was a considerable effect in cure rate of treatment versus placebo (odds 9.3, 95%CI 4.69–18.4), but all 3 trials in this comparison had serious flaws. Metronidazole treatment over more than 3 days seems to achieve a better parasitological cure rate than other long treatment courses (pooled odds 2.6, 95% 1.7–3.8), but trials are clinically and statistically heterogeneous. Single‐dose therapy is as effective as longer treatment courses (pooled odds 0.67, 95% 0.31–1.44). Within the single‐dose regimens tinidazole (2 g) reaches a higher parasitological cure rate than other short therapies (pooled odds 55, 95% CI 3.7–8.3) with relatively few side‐effects. Placebo‐controlled trials with parasitological and clincial outcomes are needed.  相似文献   
33.
Neurodevelopmental treatment (NDT) is the most used rehabilitation approach in the treatment of patients with stroke in the Western world today, despite the lack of evidence for its efficacy. The aim of this study was to conduct an intervention check and measure the nurses' competence, in positioning stroke patients according to the NDT approach. The sample consisted of 144 nurses in six neurological wards who were observed while positioning stroke patients according to the NDT approach. The nurses' combined mean competence scores within the wards was 195 (70%) of 280 (100%) possible, and for each ward the mean score varied between 181 (65%) and 206 (74%). This study indicates that nurses working in hospitals where the NDT approach has been implemented have the knowledge and skills to provide NDT nursing.  相似文献   
34.
35.
Burst-suppression EEG (BS-EEG) after cardiopulmonary resuscitation implies a bad prognosis, but little is known of the temporal dynamics of postanoxic BS-EEG. The authors studied 24 consecutive patients who developed BS-EEG within 24 hours after cardiopulmonary resuscitation, and followed 20 of these patients with serial EEGs. Except for one patient, BS-EEG was followed by another EEG pattern within 1 day, mainly areactive alpha EEG (n = 6), isoelectric EEG (n = 5), generalized continuous epileptiform discharges (n = 4), or theta; EEG (n = 3). The coexistence of different EEG patterns in the same recording was seen in 10 patients. Serial recordings disclosed a variety of EEG sequences with (often subtle) transitions between the different EEG patterns, including reappearance of BS-EEG. Postanoxic BS-EEG is followed by a variety of EEG sequences composed of different EEG patterns, each of which is recognized as an unfavorable sign in and of itself. The coexistence of different unfavorable EEG patterns in the same recording, and transitions between these EEG patterns in subsequent recordings, are common in patients with postanoxic BS-EEG. It seems reasonable to speculate that BS-EEG and subsequently evolving EEG patterns in anoxic encephalopathy reflect different forms of neocortical dysfunction, which occur at different stages of a dynamic process, leading ultimately to severe neuronal loss.  相似文献   
36.
The role of the nurse in active euthanasia and physician-assisted suicide   总被引:1,自引:0,他引:1  
The researchers wanted to obtain insight into the cooperation between physicians and nurses with regard to active euthanasia and physician-assisted suicide (EAS). In study I a stratified random sample of 203 clinical specialists, 152 general practitioners (GPs) and 50 nursing home physicians (NHPs) participated. In study II a random sample of 521 GPs was drawn from the province of North Holland and a random sample of 521 GPs was drawn from the rest of the Netherlands. For study III all NHPs were approached. Data were collected by means of an interview in study I. In studies II and III an anonymous, postal questionnaire was used. Approximately half of the GPs did not consult with nurses about a patient's request for EAS, the intention to administer EAS, and the actual administration. In 5% of cases, the NHPs and the specialists did not consult with nurses concerning these aspects. The GPs and NHPs indicated in 4% and 3% of the cases, respectively, that nurses administered the lethal drug(s) to the patients; the corresponding figure for the specialists was 21%. Almost all GPs and NHPs and about three-quarters of the specialists thought that nurses should never be allowed to administer EAS.  相似文献   
37.
Zusammenfassung. Vom 1. 1. 1985 bis zum 31. 12. 1995 wurde bei 386 Patienten mit einem Rectumcarcinom im UICC-Stadium I–III nach konventionell chirurgischen Eingriffen und R0-Resektion des Tumors der Einflu? der Zahl der dissezierten Lymphknoten auf Tumorstaging und Lokalrezidivrate retrospektiv untersucht. In der univariaten Analyse fanden wir einen signifikanten Zusammenhang zwischen der Zahl der dissezierten und der Zahl der befallenen Lymphknoten, und damit einhergehend eine signifikante Zunahme des UICC-Stadiums III (p = 0,013) und der pTxpN2-Kategorie (p = 0,000). Eine signifikante Senkung der Lokalrezidivrate in Abh?ngigkeit von der Zahl der dissezierten Lymphknoten konnte nur für das UICC-Stadium I und II nachgewiesen werden. Im Gesamtkrankengut und in der multivariaten Analyse hatte die Zahl der dissezierten Lymphknoten keinen Einflu? auf die Lokalrezidivrate. Unsere Ergebnisse zeigen, da? die Senkung der Lokalrezidivrate im UICC-Stadium I und II nicht auf einen therapeutischen Effekt, sondern auf eine Stadienverschiebung im Rahmen eines exakteren Tumorstagings zurückzuführen ist. Dies weist auf den Einflu? anderer chirurgisch beeinflu?barer Faktoren, insbesondere die totale mesorectale Excision für die Entstehung eines locoregion?ren Rezidivs hin.   相似文献   
38.
The role of the basal ganglia in syntactic language processing was investigated with event-related brain potentials in fourteen neurologically impaired patients. Seven of these patients had basal ganglia lesions while 7 other patients primarily had lesions of the left temporo-parietal region excluding the basal ganglia. All patients listened to sentences that were either correct or included a verb argument structure violation. In previous experiments this type of violation elicited a biphasic pattern of an N400-P600 complex in young healthy participants. While the N400 may result from incorrect semantic-thematic role assignment, the P600 reflects the fact that verb information does not license the syntactic structure at present. Results of the patient experiment revealed a double dissociation: patients with left temporo-parietal lesions only show a P600, whereas patients with lesions of the basal ganglia showed no P600, but a negativity with extended duration that resembled an N400. The latter pattern not only confirms previous reports that the basal ganglia modulate the P600 but extends these results by showing that the N400 as a late semantic-thematic integration process appears partially modulated by the basal ganglia.  相似文献   
39.
Nonparasitic Cysts of the Liver: Results and Options of Surgical Treatment   总被引:5,自引:0,他引:5  
n = 9) should be regarded as a palliative measure. Within a short period, CT-guided aspiration led to recurrence of symptoms in seven of our patients. Standard treatment of NPHC is fenestration with widest possible excision of the cystic wall, which can be performed laparoscopically ( n = 10) or by the conventional surgical mode ( n = 54). One patient was initially operated by the laparoscopic technique but developed bleeding, which necessitated conversion to the open mode. Three patients underwent synchronous laparoscopic cholecystectomy. Recurrence rates were similar: 11% in the laparoscopically treated group and 13% in the group that underwent conventional open surgery. Conventional surgical treatment was always successful in cases of solitary cysts. However, in cases of multiple cysts measuring more than 5 cm, conventional surgery was followed by recurrence of symptoms in 26% of patients (7/27), who then had to undergo a second operation. Partial resection of the liver ( n = 9) was successfully performed in cases of polycystic disease ( n = 5) with concomitant enlargement of the organ as well as in cases of large solitary cysts of the left lobe of the liver ( n = 4). In patients in whom we found that the cysts communicated with the ductal system ( n = 3), we performed a cystojejunostomy to drain the bile. The complication rate was low. In addition to frequent postoperative ascites, which necessitated no further intervention, we observed infectious complications in four patients. Twenty patients (22%) expired during a mean follow-up period of 6.2 years. Interestingly, deaths were frequently associated with malignancy (11/20). After fenestration of multiple cysts measuring > 5 cm, the patients are at high risk for recurrence. Hence partial resection of the liver is an excellent therapeutic alternative in selected patients with polycystic disease and massive enlargement of the organ in whom the disease could not be controlled by simple fenestration. The results of this study show that laparoscopic fenestration should replace the conventional surgical technique as the gold standard in cases of NPHC because the laparoscopic technique is less stressful for the patient and is associated with a rate of success similar to that of the conventional technique.  相似文献   
40.
Introduction and background A 3-year-old Bosnian girl with a large symptomatic brainstem and multiple supratentorial cavernous angiomas, who underwent neurosurgical treatment, is presented. As multiple cavernomas are more common in familial cases, genetic analyses and neuroradiological imaging were performed in the patient and her parents to see whether there was any evidence for inheritance. This information is important for genetic counseling and provision of medical care for at-risk relatives. Currently, no recommendation is available on how to manage these cases.Results Genetic analyses demonstrated a novel CCM1 frameshift mutation (c.1683_1684insA; p.V562SfsX6) in the child and the asymptomatic 27-year-old mother. Sensitive gradient-echo magnetic resonance imaging of the mother revealed multiple supratentorial lesions, whereas analogous imaging of the father showed no pathological findings.Conclusion This case exemplifies that seemingly sporadic cases with multiple lesions might well be hereditary and that presymptomatic genetic testing of family members may identify relatives for whom clinical and neuroradiological monitoring is indicated.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号