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   1269篇
  免费   75篇
  国内免费   12篇
耳鼻咽喉   8篇
儿科学   24篇
妇产科学   18篇
基础医学   202篇
口腔科学   28篇
临床医学   94篇
内科学   204篇
皮肤病学   19篇
神经病学   288篇
特种医学   18篇
外科学   61篇
综合类   5篇
一般理论   1篇
预防医学   135篇
眼科学   50篇
药学   136篇
中国医学   10篇
肿瘤学   55篇
  2023年   9篇
  2022年   16篇
  2021年   23篇
  2020年   13篇
  2019年   23篇
  2018年   19篇
  2017年   23篇
  2016年   37篇
  2015年   39篇
  2014年   38篇
  2013年   40篇
  2012年   80篇
  2011年   92篇
  2010年   55篇
  2009年   48篇
  2008年   80篇
  2007年   85篇
  2006年   77篇
  2005年   66篇
  2004年   79篇
  2003年   68篇
  2002年   58篇
  2001年   14篇
  2000年   13篇
  1999年   16篇
  1998年   5篇
  1997年   9篇
  1996年   8篇
  1995年   8篇
  1993年   6篇
  1992年   7篇
  1991年   10篇
  1989年   5篇
  1988年   11篇
  1987年   12篇
  1986年   8篇
  1985年   11篇
  1984年   6篇
  1983年   10篇
  1981年   6篇
  1976年   8篇
  1973年   6篇
  1966年   6篇
  1942年   5篇
  1941年   5篇
  1940年   4篇
  1938年   5篇
  1928年   4篇
  1927年   4篇
  1923年   7篇
排序方式: 共有1356条查询结果,搜索用时 0 毫秒
1.
Zusammenfassung Die Autoren berichten über dem Formenkreis der zentralen Recklinghausenschen Krankheit zugehörige seltene Geschwulstarten und vergleichen dieselben untereinander. Fall 1 entspricht der als Seltenheit in der Weltliteratur bekannten Foerster-Gagelschen diffusen zentralen Schwannose — obzwar durch die Untersuchung, besonders bei Anwendung der spezifischen Versilberungsmethoden, die morphologischen Züge von der Tumorzelle nachgewiesen werden konnten und hiermit bewiesen wurde, daß es sich um eine diffuse, das ganze Zentralnervensystem überschwemmende Überproduktion von die verschiedenen Entwicklungsstufen der Makroglia verkörpernden Zellen handelt. Vom Gesichtspunkt einer genetischen Deutung ist der Vergleich des 1. Falles mit Fall 2, welcher einen typischen, jedoch stark betonten zentralen Recklinghausen darstellt. Aus alldem wird gefolgert, daß all diese Veränderungen die Ergebnisse einer Hyperfunktion der in der Nähe der Kammeroberfläche tätigen Matrix sein dürften.  相似文献   
2.
3.
4.
Stenosis of the hypopharyngo-oesophageal junction can be a rare complication of laryngectomy and/or partial pharyngectomy and makes the insertion of voice prosthesis extremely difficult. This study describes the authors’ experiences gained by endoscopic balloon-catheter dilatation of hypopharyngo-oesophageal stenoses prior to implantation of voice prostheses in four cases. In two patients a single balloon-catheter dilatation resulted in wide enough pharyngo-oesophageal lumen on the long run. The average prosthesis wearing-times were 6.8 months in case 1 and 4.6 months in case 2, corresponding to the published literature data. In case 3, repeated dilatation of the pharyngo-oesophageal transition had proved to be unsuccessful despite taking every effort with the endoscopic balloon-catheter method. Having excised the stenotic segment, reconstruction with pectoralis major myocutaneous flap (PMMF) was indicated. Eighteen months later, a repeated restenosis was observed and a free jejunal flap needed to be performed as a final solution. In case 4, the insertion was carried out into a previously dilated jejunal free flap, which became gradually ischemic and stenotic since the major head-and neck procedure was carried out that resulted in prosthesis rejection after just 1 week. The authors emphasize that correct indication of pedicled and free flaps in head and neck reconstruction is a prerequisite from the aspect of prevention of pharyngo-oesophageal strictures. Endoscopic balloon-catheter dilatation is a safe and established method for dilatating hypopharyngo-oesophageal stenoses of different origin. The procedure provides maximum patient benefit with minimal trauma and morbidity; moreover, facilitates insertion of voice prostheses. However, a single balloon-catheter dilatation cannot always result in wide enough oesophageal lumen on the long run (case 3). Insertion of a voice prosthesis into a previously dilated ischemic jejunal segment is challenging and avoidable due to risks of complications.  相似文献   
5.
The first pharmacon with proved efficacy for the treatment of patients with the relapsing-remitting or relapsing-progressive form of multiple sclerosis (MS) was interferon-beta1b (IFN-beta1b). In 1996, we started treating 34 relapsing-remitting (RRMS) and 2 relapsing-progressive MS (RPMS) patients with IFN-beta1b. Of these 36 patients, 28 received continuous medication for 6 years. The primary end point of the study was the effect of 6 years of continuous IFN-beta1b treatment on the annual relapse rate, the secondary end point was the change in the progression index during the 6 years, and the tertiary end point was the alteration in the expanded disability status scale (EDSS) score of the patients. Finally, we give the reasons for the dropouts. The relapse rate decreased by 80.62% (p < 0.001), the mean EDSS score increased significantly, by approximately 0.5 points, to 2.21 +/- 1.48 (p = 0.016), and the reduction in the mean progression index was 67.19% (p < 0.001). This increase of < 0.5 point in the EDSS score is appreciably different from the 3-point deterioration expected after 6 years for the natural course of the disease. The significant improvement in the progression index clearly demonstrates that 6 years of IFN-beta1b therapy slowed the progression of the disease, thereby improving the quality of life of these MS patients.  相似文献   
6.
Salivary thermolytic mechanism (weight of salivary glands, effect of desalivation on water intake and body temperature, grooming activity) as well as escape behaviour and reaction to heat pain were studied in capsaicin-desensitized and control rats exposed to various warm ambient temperatures. Body temperature of the desensitized rats increased more than the controls at all the ambient temperatures studied (32, 34 and 36°C); however, significant differences in the mechanism of salivary cooling were obtained only at 34 and 36°C. Central impairment of saliva spreading in desensitized rats seems evident. Complete surgical desalivation did not increase hyperthermia of control and desensitized animals in warm environments. Therefore other mechanisms, primarily vasodilatatory, must also be involved in the rat's thermolytic normal response. Although desensitized rats did not show a tendency to escape from the warm environment their response to heat pain was normal. In conclusion, it is suggested that heat perception in desensitized animals is impaired; however, the existence of some capsaicin-insensitive thermolytic mechanisms (prone extension of the body) cannot be excluded.Supported by the Scientific Research Council, Ministry of Health, Hungary /4-05-0303-04-2/0/ and MTA-OM-MÉM-EÜM 70.211/79  相似文献   
7.
Following up the results of a previous population association study (Lakatos et al. [2000: Mol Psychiatry 5:633-637; Lakatos et al. [2002: Mol Psychiatry 7:27-31]) by analyses based on parental genetic data confirmed the link between infant attachment and the dopamine D4 receptor (DRD4) gene. Extended transmission disequilibrium tests (ETDT) were performed to determine whether biased transmission of exon III 48 basepair repeat alleles occurred to infants displaying disorganized and secure attachment behavior with their mothers. The overall allele-wise TDTs were significant for both groups (P = 0.038 and 0.020, respectively): a trend for preferential transmission of the seven-repeat allele to disorganized infants was observed (TDT(chi)(2) = 3.27, df = 1, P = 0.071), and there was a significant non-transmission of the same allele to securely attached infants (TDT(chi)(2) = 6.00, df = 1, P = 0.014). Analysis of haplotypes of the exon III repeat and the -521 C/T promoter polymorphisms in family trios showed that the transmission bias in the larger secure group was due to the low-rate transmission of the T.7 haplotype containing both the seven-repeat and the -521 T alleles (TDT(chi)(2) = 4.46, df = 1, P = 0.035). This suggests that not carrying the T.7 haplotype of the DRD4 gene may act as a resilience factor in the optimal development of early attachment.  相似文献   
8.
Yersinia pestis, the etiologic agent of plague is a highly invasive organism being able to invade non-phagocytic epithelial cells. Its plasminogen activator (Pla), encoded by the pPCP1 plasmid plays a pivotal role in internalisation of bacteria by HeLa cells. The aim of this study was to analyse the intracellular signalling processes and cytoskeletal rearrangement events associated with invasion. Wortmannin caused a 50% decrease of invasiveness at 50nM concentration pointing to the involvement of phosphatidyl-inosinol-4 kinase (PtINs4). Pre-treatment with staurosporin, a potent inhibitor of protein kinases (PKs) and with genistein, a specific tyrosine kinase inhibitor decreased the number of internalised bacteria about seven-fold and two-fold, respectively, indicating the involvement of PKs including tyrosine kinases in Pla-mediated internalisation. Cytochalasin D, an actin polymerisation inhibitor, C3 exoenzyme of Clostridium botulinum, a specific inhibitor of small GTPase Rho, and NDGA, a 5-lipoxygenase inhibitor also involved in Rho activation strongly reduced the number of internalised bacteria revealing the role of cytoskeletal events in the invasion process. All the tested inhibitors changed the invasion but not the adhesion pattern of the Pla producing recombinant strain. Actin rearrangement could also be visualised also with rhodamin-phalloidin staining.  相似文献   
9.
This study investigated the relationship between theory of mind (ToM) deficits and visual perception in patients with schizophrenia (N=52; 17 remitted and unmedicated) compared with healthy controls (N=30). ToM was assessed with the Eyes Test, which asked participants to choose which of 4 words best described the mental state of a person whose eyes were depicted in a photograph. Visual perception was evaluated with form and motion coherence threshold measurements. Results revealed that patients with schizophrenia (both remitted and nonremitted) showed deficits on the Eyes Test and the motion coherence task. ToM dysfunctions were associated with higher motion coherence thresholds and more severe negative symptoms. This suggests that ToM deficits are related to motion perception dysfunctions, which indicates a possible role of motion-sensitive areas in the pathophysiology of schizophrenia.  相似文献   
10.
The effects of vitamin A were studied on the basal and maximal gastric secretory responses of 12 patients; and on healing in 60 patients with chronic gastric ulcer. The effect of vitamin A on ulcer healing was evaluated by a multiclinical, multicentre, randomized, prospective study in which the patients were divided into three groups. In group A the patients were treated with antacids only; in group B the patients were given antacids plus vitamin A (in doses of 3 X 50.000 U orally); and in group C the patients received antacids, vitamin A plus cyproheptadine (in doses of 3 X 4 mg orally). The treatment lasted four weeks. At the beginning and the end of treatment endoscopies were performed and ulcer sizes were measured planimetrically. Various other parameters such as ulcer index, antacid consumption and laboratory parameters were also evaluated during the four-week treatment. It was observed that: (i) vitamin A (given in doses of 100.000 U i.m.) decreased neither basal nor maximal gastric secretory responses; (ii) the number of patients with completely healed gastric ulcer was significantly higher (P less than 0.05) in groups B and C than in group A; (iii) the extent of ulcer reduction was significantly higher (P less than 0.01) in groups B and C than in group A; (iv) no significant changes were observed in ulcer index and antacid consumption during the four-week treatment in the different groups of patients; (v) the reduction of ulcer size was significantly greater (P less than 0.01) in the group treated with antacids plus vitamin A than in the group treated with antacids only, at two weeks of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)  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