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   1582篇
  免费   120篇
  国内免费   4篇
耳鼻咽喉   12篇
儿科学   66篇
妇产科学   19篇
基础医学   213篇
口腔科学   37篇
临床医学   190篇
内科学   352篇
皮肤病学   94篇
神经病学   97篇
特种医学   110篇
外科学   217篇
综合类   12篇
预防医学   67篇
眼科学   25篇
药学   122篇
肿瘤学   73篇
  2021年   24篇
  2020年   12篇
  2019年   20篇
  2018年   28篇
  2017年   32篇
  2016年   32篇
  2015年   32篇
  2014年   40篇
  2013年   63篇
  2012年   97篇
  2011年   89篇
  2010年   52篇
  2009年   44篇
  2008年   76篇
  2007年   97篇
  2006年   59篇
  2005年   57篇
  2004年   53篇
  2003年   63篇
  2002年   74篇
  2001年   51篇
  2000年   70篇
  1999年   45篇
  1998年   23篇
  1997年   22篇
  1996年   13篇
  1995年   14篇
  1994年   9篇
  1993年   10篇
  1992年   19篇
  1991年   27篇
  1990年   17篇
  1989年   17篇
  1988年   17篇
  1987年   13篇
  1986年   17篇
  1985年   14篇
  1984年   10篇
  1979年   11篇
  1978年   16篇
  1974年   12篇
  1973年   11篇
  1972年   14篇
  1971年   15篇
  1970年   13篇
  1969年   12篇
  1968年   8篇
  1967年   10篇
  1966年   9篇
  1965年   9篇
排序方式: 共有1706条查询结果,搜索用时 46 毫秒
1.
Trauma und Berufskrankheit - Zusammenfassung Der Processus coronoideus ist der wichtigste knöcherne Stabilisator des Ellbogengelenks, der vordere Anteil des Lig. collaterale ulnae, welcher am...  相似文献   
2.
ABSTRACT The paper explores two literary texts - Dostoevsky's novel Crime and Punishment and Euripides'play Bacchae - from the point of view of immature masculinity and the catastrophe that can follow if the boy fails to achieve a genuine separation from the maternal object. The author examines the masculine anxieties and defences that arise when the boy fails to work through the Oedipus complex and instead retreats to a dyadic relation with mother which excludes the father. This retreat involves a denial of reality and the creation of a paranoid world in which his own wishes to take possession of mother can be experienced by him as an intrusion by the mother into his own masculine identity and ultimately as castration by the mother. Attempts to resolve this threat to masculinity include the use of anal defences and tyrannical states of mind in the creation of a pseudo-masculinity.
The movement into the male Oedipus complex necessarily involves a psychological state in which the externality of the oedipal-object mother is continually in danger of being blurred by the shadow cast by the pre-oedipal mother. (Thomas Ogden 1992)  相似文献   
3.
We report a case of recurrent inguinal lymphocele formation after inguinal lymphadenectomy treated by lymphographic mapping and selective ligation of the lymphatic vessels. Lymphographic mapping was performed by puncturing a lymphatic vessel at the dorsum of the foot. After isolating the vessels that drained into the lymphocele, they were clipped and divided through a small skin incision. The described technique showed an instant and complete suspension of the lymph secretion with subsequent complete healing. Lymphatic mapping and selective ligation of afferent lymphatic vessels proved to be an effective treatment of a recurrent inguinal lymphocele.  相似文献   
4.
Trauma und Berufskrankheit - Zusammenfassung Diese Arbeit beschäftigt sich mit der Häufigkeit, dem Entstehungsmechanismus und der Behandlung von Bizepssehnenrupturen. Veränderte...  相似文献   
5.
Complex injuries of the foot are often overlooked, especially in the multiple injured patient, and they then lead to major loss of function. When the mechanism of injury suggests involvement of the foot, a clinical examination of the lower extremities should be included in the primary diagnostic procedures implemented in the multiply injured patient, followed by radiological examination once the patient's condition is stable. The condition of the soft tissues is of decisive importance in the prognosis of complex foot injuries, regardless of whether the damage to the foot is one component of a polytrauma or an isolated injury, which can also be life threatening. The diagnostic examinations selected should be adapted to the severity of the injuries in the particular multiply injured patient. Successful therapy involves stable internal fixation of injuries to bones and joints, though the external fixation options should be considered in the first instance, and carefully selected methods of temporary and definitive soft tissue reconstruction. The aim of treatment is the best possible reconstruction of the foot as a functional weight-bearing unit with intact soft tissue cover and a natural form. Good results can be achieved when there is close interdisciplinary cooperation between trauma (orthopedic) and plastic surgeons. Patient with severe injuries of this kind should be transferred to a trauma center as the first step toward this end.  相似文献   
6.
Cerebral muscarinic cholinergic receptors were imaged and regionally quantified in vivo in humans with the use of [11C]scopolamine and positron emission tomography. Previous studies in experimental animals have suggested the utility of radiolabeled scopolamine for in vivo measurements, on the bases of its maintained pharmacologic specificity following systemic administration and the exclusion of labeled metabolites from the brain. The present studies describe the cerebral distribution kinetics of [11C]scopolamine in normal subjects following intravenous injection. Scopolamine is initially delivered to brain in a perfusion-directed pattern. After 30 to 60 min, activity is lost preferentially from cerebral structures with low muscarinic receptor density including the cerebellum and thalamus. Activity continues to accumulate throughout a 2 h postinjection period in receptor-rich areas including cerebral cortex and the basal ganglia. The late regional concentration of [11C]scopolamine does not, however, accurately parallel known differences in muscarinic receptor numbers in these receptor-rich areas. Tracer kinetic analysis of the data, performed on the basis of a three-compartment model, provides receptor binding estimates in good agreement with prior in vitro measurements. Kinetic analysis confirms significant contributions of ligand delivery and extraction to the late distribution of [11C]scopolamine, reconciling the discrepancy between receptor levels and tracer concentration. Finally, a novel dual-isotope method for rapid chromatographic processing of arterial blood samples in radiotracer studies is presented. The combination of rapid chromatography and compartmental analysis of tracer distribution should have broad utility in future in vivo studies with short-lived radioligands.  相似文献   
7.
Myonecrosis induced in vivo by cardiotoxin, melittin, and Asp49 and Lys49 phospholipase A2 (PLA2) myotoxins involves rapid lysis of the sarcolemma, myofibril clumping, and hypercontraction of sarcomeres. In contrast, skeletal muscle necrosis induced by crotamine and myotoxin a is much slower, consisting of mitochondrial and sarcoplasmic reticulum swelling, myofibril degeneration, and lack of sarcolemma or transverse tubule damage. The mechanisms contributing to the myonecrosis induced by these peptides were evaluated. Two cardiotoxins and two Lys49 PLA2 myotoxins lysed primary cultures of human skeletal muscle within 24 hr at a concentration of 0.25 μM, while melittin, crotamine, and myotoxin a, and an Asp49 PLA2 myotoxin were non-cytolytic at concentrations up to 5.0 μM, suggesting that cytolysis is not a good measure of myotoxicity. Crotamine and the Lys49 PLA2 myotoxin altered Ca2+ ion flux in human heavy sarcoplasmic reticulum by opening the ryanodine receptor. Whole-cell patch-clamp studies demonstrated that administrating crotamine intracellularly increased Na+ currents. Free fatty acids, liberated by activation of tissue phospholipase C or by the PLA2 activity of the myotoxins, were monitored for crotamine, myotoxin a and a Lys49 PLA2 myotoxin in cell cultures in which the lipids had been radiolabeled. Only the Lys49 myotoxin produced significant amounts of fatty acid in cell cultures, supporting a potential role for fatty acid production only in the mechanism of sarcolemma-destroying myotoxins. These findings, coupled with those in the literature, support a hypothesis in which the myotoxins and/or products of lipase activity (e.g. fatty acids) are acting at a site existing on both the Na+ channel and a protein involved in Ca2+ release and probably serving a modulatory function for ion regulation. Based on the similarities in mechanisms between the toxins and fatty acids, the most likely site would be a fatty acid binding site on the protein (either similar to that on fatty acid binding proteins, or an acylated cysteine residue) or in the membrane.  相似文献   
8.
We have used the techniques of DNA fingerprinting and polymerase chain reaction (PCR) with probes specific for hypervariable repetitive DNA sequences (mini- and microsatellite DNAs) to analyze 36 yeast strains belonging to 10 species and 2 genera. Using (GTG)5, (GACA)4, phage M13 DNA and the M13 sequence GAGGGTGGCGGTTCT as probes and primers, respectively, we obtained DNA polymorphisms which allowed us to discriminate 23 biotechnologically important strains of the yeast Saccaromyces cerevisiae and to distinguish them from strains of S. pastorianus, S. bayanus and S. willianus. Our results demonstrate that both DNA and PCR fingerprinting are suitable tools for an easy, fast and reliable molecular typing of yeasts. The DNA fingerprinting method seems to be more sensitive than PCR fingerprinting with respect to the individualization of strains. Nevertheless, using the PCR fingerprinting technique we were able to unambigously dicriminate between yeast genotypes of different species. Therefore, PCR fingerprinting might become a useful tool in the classification of yeasts on the basis of phylogenetic relatedness.  相似文献   
9.
The objective of this study was to study the responses of osteoblast-like cells to rough Titanium (Ti)-coated epoxy surfaces of differing topographic complexity. Four topographies were studied: polished (PO), coarse-blasted (CB), acid-etched (AE) and coarse-blasted+acid-etched (SLA). Rat osteoblasts were cultured on these surfaces and their morphology, thickness as well as the number and size of bone-like nodules measured. To determine cell shape and cell thickness, fluorescein-5-thiosemicarbazide was used to stain the cell components including the cell membrane, the stained cells were optically sectioned using epifluorescent microscopy and the optical sections were computationally reconstructed to obtain three-dimensional images in which cell volume and cell thickness could be determined. Similarly optical sections of bone-like nodules labeled with tetracycline were also reconstructed to determine their size. The different surface topographies were found to alter the thickness and morphology of osteoblasts cultured on these surfaces. Osteoblasts produced significantly more and larger nodules on SLA compared to other surfaces. Nevertheless and perhaps surprisingly, given the evidence in various cell populations that cell shape can affect cell differentiation, cell thickness was not directly correlated with an increase in bone-like nodule formation. Data were analyzed by factorial analysis of variance. In this way the primary effect of each surface treatment ( i.e. blasting and acid etching) could be assessed as well as their interaction. Both the acid etching and blasting processes significantly affected the number and size of bone-like nodules cultured on Ti surfaces. Moreover there were significant interaction effects indicating that surface topographic features can act synergistically to enhance bone formation. This result suggests that a useful approach to the optimization of surfaces for bone production could involve systematic investigation of combinations of processes each of which produces distinct surface topographical features.  相似文献   
10.
Laudationes     
Ohne ZusammenfassungHerr Professor Dr.James E. Rothman wurde 1950 in Haverhill/Mass. geboren, studierte am Yale-College und am Department of Biological Chemistry, Harvard Medical School sowie am Department of Biology, Massachusetts Inst. of Technology von 1967–1978. Daraufhin wurde er Assistant Professor, 3 Jahre später Associate Professor und nach weiteren 3 Jahren Professor am Department of Biochemistry, Stanford University. Seit 1988 ist er Squibb Professor of Molecular Biology am Department of Biology an der Princeton University.Herr Prof. Dr.K.W.A. Wirtz wurde 1942 in Utrecht geboren, erhielt seine Ausbildung in Biochemie und Physiologie an den Universitäten von Utrecht und Cornell Univ. Ithaka und promovierte mit einer Arbeit unter Prof. L.L.M. van Deenen (Heinrich-Wieland-Preis 1971). Unterbrochen durch längere Aufenthalte im Ausland, wurde er 1973 Assistant Professor und 1980 Professor für Biochemie an seiner heutigen Wirkungsstätte.  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