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   9246篇
  免费   565篇
  国内免费   105篇
耳鼻咽喉   101篇
儿科学   159篇
妇产科学   197篇
基础医学   1033篇
口腔科学   281篇
临床医学   798篇
内科学   2850篇
皮肤病学   193篇
神经病学   726篇
特种医学   363篇
外科学   1435篇
综合类   23篇
一般理论   1篇
预防医学   370篇
眼科学   114篇
药学   497篇
中国医学   7篇
肿瘤学   768篇
  2023年   138篇
  2022年   278篇
  2021年   508篇
  2020年   294篇
  2019年   334篇
  2018年   391篇
  2017年   273篇
  2016年   324篇
  2015年   328篇
  2014年   436篇
  2013年   496篇
  2012年   722篇
  2011年   652篇
  2010年   372篇
  2009年   355篇
  2008年   501篇
  2007年   484篇
  2006年   446篇
  2005年   361篇
  2004年   306篇
  2003年   278篇
  2002年   234篇
  2001年   148篇
  2000年   136篇
  1999年   111篇
  1998年   63篇
  1997年   31篇
  1996年   49篇
  1995年   38篇
  1994年   37篇
  1993年   22篇
  1992年   84篇
  1991年   71篇
  1990年   57篇
  1989年   69篇
  1988年   67篇
  1987年   62篇
  1986年   46篇
  1985年   50篇
  1984年   22篇
  1983年   15篇
  1981年   17篇
  1980年   13篇
  1979年   25篇
  1978年   18篇
  1977年   13篇
  1976年   15篇
  1974年   22篇
  1973年   14篇
  1966年   12篇
排序方式: 共有9916条查询结果,搜索用时 234 毫秒
81.
82.
The Authors describe the interposition vein cuff technique as an adjuvant method to infrainguinal prosthetic bypass grafts. The haemodynamic, mechanical and humoral factors thought to be involved in the beneficial effects of the vein cuff are herein discussed. The results of the main series suggest the use of this method particularly in patients without any available autologous vein conduit requiring a below-knee popliteal or crural reconstruction.  相似文献   
83.
The Authors, on the basis of their experience with neoplastic colorectal pathology and after a review of the Literature, report a reappraisal of the problems related to colorectal multiple carcinomas. They emphasize the importance of routine preoperative pancolonoscopy for the identification of possible synchronous tumors (both benign and malignant) and periodic endoscopic follow-up (ideally a life-long one) for the detection and removal of all adenomatous polyps as well as early stage metachronous carcinomas, especially for patients with HNPCC. Besides, they stress the importance of sensibilization of the population about the heritability of colorectal carcinomas.  相似文献   
84.
Ajoene (CAS 92284-99-6), an organic trisulphur originally isolated from garlic, has an antimycotic activity which has been widely demonstrated both in vitro and in vivo. The objective of this work was to compare the safety and effectiveness of ajoene (0.6%, gel) with terbinafine (CAS 91161-71-6) (1%, cream) for the treatment of tinea corporis and tinea cruris. The patients selected were 60 soldiers with clinical and mycological diagnosis of either dermatophytosis. They were distributed at random in two treatment groups, one treated with ajoene at 0.6% and the other with terbinafine at 1%. All patients were evaluated clinically and mycologically 30 and 60 days after completion of the treatment, which was considered effective when clinical signs and symptoms had disappeared and the mycological cultures were negative. Thirty days after treatment, the percent healing rate was 77 and 75 for the groups treated with ajoene and terbinafine, respectively. Sixty days after treatment, the healing rate 73% and 71% for the groups treated with ajoene and terbinafine, respectively. These results and those obtained in previous studies confirm that ajoene is a new agent for the topic treatment of superficial mycoses, and for the first time show the therapeutic usefulness of an inhibitor of phospholipids biosynthesis in eukaryotes.  相似文献   
85.
86.
A new highly specific, potent non-peptide agonist for the cholecystokinin subtype 1 receptor (CCK(1)), SR 146131 (2-[4-(4-chloro-2, 5-dimethoxyphenyl)-5-(2-cyclohexyl-ethyl)-thiazol-2-ylcarbamoyl ]-5, 7-dimethyl-indol-1-yl-1-acetic acid) was recently described [Bignon, E., Bachy, A., Boigegrain, R., Brodin, R., Cottineau, M., Gully, D., Herbert, J.-M., Keane, P., Labie, C., Molimard, J.-C., Olliero, D., Oury-Donat, F., Petereau, C., Prabonneaud, V., Rockstroh, M.-P., Schaeffer, P., Servant, O.Thurneyssen, O., Soubrié, P., Pascal, M., Maffrand, J.-P., Le Fur, G., 1999. SR 146131: a new, potent, orally active and selective non-peptide cholecystokinin subtype I receptor agonist: I. In vitro studies. J. Pharmacol. Exp. Ther. 289, 742-751]. From binding and activity assays with chimeric constructs of human CCK(1) and the cholecystokinin subtype 2 receptor (CCK(2)) and receptors carrying point mutations, we show that Leu(356), situated in transmembrane domain seven in the CCK(1) receptor, is a putative contact point for SR 146131. In contrast, Leu(356) is probably not in contact with the CCK(1) receptor specific antagonist SR 27897 (1-[2-(4-(2-chlorophenyl)thiazol-2-yl)aminocarbonyl indoyl]acetic acid), a compound structurally related to SR 146131, since its replacement by alanine, histidine or asparagine gave receptors having wild-type CCK(1) receptor SR 27897 binding affinity. Previous mutational analysis of His(381), the cognate position in the rat CCK(2) receptor, had implicated it as being involved in subtype specificity for SR 27897, results which we confirm with corresponding mutations in the human CCK(2) receptor. Moreover, binding and activity assays with the natural CCK receptor agonist, CCK-8S, show that CCK-8S is more susceptible to the mutations in that position in the CCK(1) receptor than in the CCK(2) receptor. The results suggest different binding modes for SR 27897, SR 146131 and CCK-8S in each CCK receptor subtype.  相似文献   
87.
PURPOSE: Loss of a certain amount of cutaneous tissue of the perineal region may be remedied by first intention with creation of cutaneous flaps, thus preventing second intention healing. METHODS: We present three emblematic cases in which the posterior perineal region was reconstructed by means of vertical subcutaneous pedicle flaps, subsequent to cutaneous tissue loss after surgery for extensive condilomas or neoplastic pathologies. RESULTS: Tissue loss was repaired by means of a V-Y type vertical subcutaneous pedicle flap, constructed laterally of the extirpation zone and advanced in a median direction. In all cases, no ischemia or infection of flaps occurred; sphincteral continence and long-term aesthetic results have proved to be satisfactory. CONCLUSIONS: Vertical pedicle subcutaneous flaps are well vascularized, extremely mobile, and easy to perform and have no serious postoperative complications.  相似文献   
88.
Summary Instances of human bites are generally rare, although it does sometimes occur that people use their teeth as a means of attack of defence. When looking into cases of the ill-treatment of children we often find bite-marks in addition to other signs of abusement.Eleven cases from the Institute of Forensic Medicine at Düsseldorf University are presented out of a total of 48 cases of ill-treatment of children followed by death in which human bite-marks as well as other haematomas on the victims could be proved. In all cases the cause of death was a subdural haematoma. All but three of the offenders were female, and all were young and subject to excess stress so that the act could eventually be regarded as the result of a disintegration of emotional status.The combination of bite-marks with haematomas and other signs of ill-treatment support with sufficient certainty the conclusion that a criminal action of a third person is involved.
Bißverletzungen bei mißhandelten Kindern
Zusammenfassung Obwohl es immer wieder vorkommt, daß Menschen zum Angriff oder Verteidigung ihre Zähne als Waffe gebrauchen, werden Menschenbißspuren bei der Obduktion relativ selten beobachtet. Sie führen in der Regel nicht zum Tode, sondern stellen nur einen Begleitbefund dar, der Hinweise auf den Tatablauf und den Täter zu geben geeignet ist. Manchmal werden Bißverletzungen im Verlaufe von Handlungen Geisteskranker oder zur Befriedigung des Geschlechtstriebes erzeugt. In der Regel sind Menschenbißspuren — gerade bei Mißhandlung von Kleinkindern — kombiniert mit anderen Zeichen der Gewalteinwirkung. Der Mensch beißt in die unbekleideten Körperstellen. Besonders gefährdet sind Nase, Ohrläppchen, Finger. Beim Kind sind häufig die Extremitäten, besonders die Oberschenkel, betroffen.In den letzten Jahren haben wir im Institut für gerichtliche Medizin der Universität Düsseldorf mehrere einschlägige Fälle obduziert. Es handelt sich um 11 von insgesamt 48 Mißhandlungen mit Todesfolge, in denen Menschenbißspuren neben anderen Hämatomen bei den Opfern haben nachgewiesen werden können. Sie werden kurz dargestellt.Die Todesursache war in 8 Fällen ein subdurales Hämatom. Einmal verblutete das drei Monate alte Kind (Fall 9) aus dem eingerissenen Mesenterium in den Bauchraum. Ein Kind erlitt eine Ruptur der rechten Herzkammer und starb infolge einer Herzbeuteltamponade (Fall 11). In einem Fall war die Todesursache nicht eindeutig zu klären (Fall 8).Bei den Tätern überwiegt, wie bei der Kindesmißhandlung überhaupt, die leibliche Mutter. Es handelte sich um 8 weibliche und 3 männliche Täter. Die Täterinnen waren meistens jung und überfordert, so daß die Tat letzten Endes als Lösung eines Affektstaues angesehen werden kann. Die Aggression galt eigentlich dem Erzeuger des Kindes und den mißlichen Umständen. Bei einem männlichen Täter handelte es sich um den Freund der Kindesmutter, der, selbst arbeitslos, das Kind während der Erwerbstätigkeit der Mutter beaufsichtigte. Er will das Kind beim Balgen und Spielen gebissen haben. Ein Vater — ein Italiener — gab auf Vorhalt an, sein vor der Ehe gezeugtes Kind aus Liebe gebissen zu haben. Sexuelle Motive mögen ebenso wie bei den Täterinnen mitgespielt haben. Ein anderer Vater will das Kind, als es drohte zu sterben, gebissen haben, um es wiederzubeleben.Die Kombination von Bißspuren mit Hämatomen und Frakturen und anderen Zeichen der Gewalteinwirkung läßt mit der erforderlichen Sicherheit auf die strafwürdige Mitwirkung Dritter schließen.
  相似文献   
89.
The metabolism of isoflurane and the investigational volatile anaesthetic desflurane to fluoride ion was examined in 25 surgical patients. The patients were randomly assigned to four groups, to receive isoflurane or desflurane at either 0.65 MAC or 1.25 MAC. Anaesthesia was induced in all patients with thiopentone and midazolam and included nitrous oxide 60% in addition to the volatile agent. Blood was drawn before induction and at the end of the operation for determination of serum fluoride ion concentration. Plasma fluoride ion concentrations increased (+ 1.36 +/- 0.93 microM, P less than 0.01) in patients receiving isoflurane but were unchanged (-0.13 +/- 0.50 microM) in patients receiving desflurane. Metabolic release of fluoride ion is less with desflurane than with isoflurane during administration of the anaesthetics to surgical patients, and is unlikely to be of clinical significance.  相似文献   
90.
Summary Homovanillic acid (HVA) and 5-hydroxyindolacetic acid (5-HIAA) in ventricular CSF were determined in 19 patients (12 female 7 male) with brain tumours. No relationship was found between ventricular fluid pressure (VFP) and levels of HVA and 5-HIAA. A relationship was observed between ventricular CSF, HVA concentrations and tumour induced alterations in CSF dynamics. HVA concentrations were very high in patients whose tumours involved the third ventricle, the aqueduct, or the fourth ventricle, producing marked alterations in CSF flow. HVA concentrations significantly lower than in controls were observed in cases where tumours involved the lateral ventricles. Concentrations of acid metabolites in patients with little or no alteration in CSF dynamics corresponded with those in patients with other neurosurgical disorders.  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