Anaemia is a frequent problem after renal transplantation, whichmay appear as hypo-regenerative anaemia (due to myelotoxic drugsor infectious agents and/or poor graft function) or hyper-regenerativeanaemia (haemolysis or bleeding). It, therefore, seems reasonableto distinguish between different underlying causes of anaemiaaccording to reticulocyte counts. One of the presumably rather rare infectious agents causingtransient hypo-regenerative anaemia is the human parvovirusB19 (HPV B19) that was discovered in human blood 25 years ago[1] and was found to be the cause of ‘fifth disease’in children in the 1980s  相似文献   
27.
Molecular identification of a small supernumerary marker chromosome by in situ hybridization: diagnosis of an isochromosome 18p with probe L1.84   总被引:1,自引:0,他引:1  
Elisabeth Blennow  Karen Bröndum Nielsen 《Clinical genetics》1991,39(6):429-433
A dysmorphic child was found by cytogenetic analysis to have an extra small marker chromosome. The marker chromosome was shown to possess a chromosome 18 centromere by in situ hybridization, and probably represents an isochromosome 18p. Centromere specific probes should be of value in identifying extra small marker chromosomes, and thereby provide better understanding of the clinical significance of these.  相似文献   
28.
Prevalence of extraesophageal reflux in patients with symptoms of gastroesophageal reflux.     
Riitta Ylitalo  Stig Ramel  Birgitta Hammarlund  Elisabeth Lindgren 《Otolaryngology--head and neck surgery》2004,131(1):29-33
OBJECTIVES: To compare the prevalence of extraesophageal reflux (EER) in patients with heartburn, posterior laryngitis (PL), and in healthy controls.Study design and setting A retrospective and prospective study including a total of 101 subjects who underwent 24-hour dual-probe pH monitoring. RESULTS: 52% of the subjects with heartburn had EER. No significant differences were found between the PL and heartburn groups for any pharyngeal reflux parameters. However, supine pharyngeal reflux was significantly more prevalent in heartburn patients with GERD than in PL patients and healthy controls (P < 0.05). Significant positive correlation (P < 0.01) was found between the percentage of time pH <4 in the pharynx and in the distal esophagus. CONCLUSION: EER occurs in the majority of heartburn patients who are lacking laryngeal symptoms. Abnormal distal esophageal acid exposure makes the occurrence of EER more likely. SIGNIFICANCE: EER appears to be a continuum without clear-cut differences between the groups.  相似文献   
29.
Changing patterns of intellectual strengths and weaknesses in males with fragile X syndrome     
Robert M. Hodapp  Elisabeth M. Dykens  Sharon I. Ort  Davida G. Zelinsky  James F. Leckman 《Journal of autism and developmental disorders》1991,21(4):503-516
Examined the changing profiles of intelligence in males with fragile X syndrome as these individuals increased in chronological age. Using a psychometric instrument designed to measure styles of information processing, 21 males aged 4 to 27 years were examined cross-sectionally in sequential processing, simultaneous processing, and achievement. The age of the subject was associated with age-equivalent levels of both simultaneous processing and achievement, but fragile X males did not show higher levels of sequential processing with increasing chronological age. Compared to younger fragile X males, the older subjects were more delayed in sequential processing skills relative to their abilities in other areas. A smaller longitudinal study confirmed the presence of a plateau in sequential processing among those subjects tested two times after the age of 10 years. Implications are discussed for diagnosis, intervention, and the matching of subject groups in mental retardation research.This research was supported in part by the John Merck Fund, the Joseph P. Kennedy, Jr. Foundation, NIH grants RR00125 and HD03008, and NIMH grants MH18268 and MH30929. We thank Wendy Marans and Joel Bregman for their comments on an earlier draft of this paper.  相似文献   
30.
Cerebrospinal Fluid Density Influences Extent of Plain Bupivacaine Spinal Anesthesia     
Schiffer  Eduardo M.D.; Van Gessel  Elisabeth M.D.&#x;; Fournier  Roxane M.D.; Weber  Anne M.D.; Gamulin  Zdravko M.D.&#x; 《Anesthesiology》2002,96(6):1325-1330
Background: The attempts to explain the unpredictability of extent of spinal block provided by plain local anesthetic solutions have resulted in many clinical reports; however, causes of this uncertainty are as yet unknown. Recently, normal values of the human cerebrospinal fluid densities have been studied showing important interindividual variations, especially between females and males. The current study was designed to evaluate as primary endpoint the influence of cerebrospinal fluid density values on the extent of spinal block with plain bupivacaine. The ancillary endpoints were search of factors explaining the interindividual differences in cerebrospinal fluid density values reported and determination of the relation between upper extent and regression of spinal anesthesia.

Methods: Sixty-four consecutive patients undergoing peripheral orthopedic surgery with spinal block were enrolled. Spinal anesthesia was performed in the lateral decubitus position with the operated side upward. Two milliliters of cerebrospinal fluid was sampled before injection of 3 ml plain bupivacaine 0.5%. The patient was immediately turned supine and remained in the horizontal position until the end of the study. Maximal sensory block level and time to sensory regression to L4 were determined for each patient enrolled. Cerebrospinal fluid and bupivacaine densities as well as cerebrospinal proteins, glucose, sodium, and chloride concentrations were measured.

Results: A highly significant correlation between cerebrospinal fluid density and maximal sensory block level was found (P = 0.0004). However, this correlation was poorly predictive (R2 = 0.37). Cerebrospinal fluid density, proteins, and glucose concentrations were significantly higher in men than in women: 1.000567 +/- 0.000091 versus 1.000501 +/- 0.000109 g/ml (P = 0.014), 0.46 +/- 0.18 versus 0.32 +/- 0.13 g/l (P = 0.001), and 3.27 +/- 0.7 versus 2.93 +/- 0.5 mm (P = 0.023), respectively. A highly significant (P = 0.0004) and predictive (R2 = 0.73) inverse correlation was found between maximal upper sensory extent and sensory regression to L4.  相似文献   

[首页] « 上一页 [1] [2] 3 [4] [5] [6] [7] [8] [9] [10] [11] 下一页 » 末  页»
  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   13994篇
  免费   968篇
  国内免费   38篇
耳鼻咽喉   148篇
儿科学   519篇
妇产科学   364篇
基础医学   2070篇
口腔科学   207篇
临床医学   1699篇
内科学   2600篇
皮肤病学   368篇
神经病学   1661篇
特种医学   341篇
外科学   1362篇
综合类   72篇
一般理论   13篇
预防医学   1123篇
眼科学   236篇
药学   958篇
中国医学   17篇
肿瘤学   1242篇
  2023年   99篇
  2022年   143篇
  2021年   304篇
  2020年   250篇
  2019年   331篇
  2018年   368篇
  2017年   313篇
  2016年   379篇
  2015年   419篇
  2014年   521篇
  2013年   723篇
  2012年   1097篇
  2011年   1054篇
  2010年   647篇
  2009年   578篇
  2008年   892篇
  2007年   918篇
  2006年   895篇
  2005年   852篇
  2004年   785篇
  2003年   733篇
  2002年   690篇
  2001年   103篇
  2000年   59篇
  1999年   119篇
  1998年   170篇
  1997年   135篇
  1996年   105篇
  1995年   116篇
  1994年   73篇
  1993年   85篇
  1992年   66篇
  1991年   68篇
  1990年   70篇
  1989年   52篇
  1988年   52篇
  1987年   35篇
  1986年   34篇
  1985年   41篇
  1984年   35篇
  1983年   43篇
  1982年   52篇
  1981年   24篇
  1980年   35篇
  1979年   33篇
  1978年   23篇
  1977年   24篇
  1976年   30篇
  1975年   17篇
  1974年   23篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Zusammenfassung. Ziel: Die psychische Belastung bei Patienten mit akutem Herzinfarkt innerhalb der ersten 48 h auf der Intensivstation des Städtischen Krankenhauses Kiel wird mit Hilfe der Symptom-Checkliste (SCL-90-R) gemessen. Patienten und Methodik: 134 hauptsächlich wegen eines akuten Herzinfarkts aufgenommene Patienten wurden zwischen August 1996 und Juli 1999 randomisiert ausgewählt. Sie füllten einen der Intensivstation angepassten Fragebogen aus, der u. a. neben Fragen zu sozioökonomischen Daten die standardisierten SCL-90-R enthält. Ergebnisse: Erhöhte Mittelwerte zeigten sich vor allem für die Skalen Somatisierung, Ängstlichkeit, Depressivität und GSI (Global Severity Index) bei solchen Patienten, die wenig soziale Unterstützung bekamen und über ein niedriges Einkommen verfügten. Schlussfolgerung: Da für Patienten mit schlechtem sozialen Netzwerk, niedrigem sozialen Status, erhöhter Angst und Depressivität eine schlechtere Prognose hinsichtlich der Mortalität und Wiedereingliederung in den Beruf beschrieben wurde, ist es im prospektiven Verlauf dieser Studie notwendig, gerade diese Patienten hinsichtlich der Entwicklung ihrer Angst zu erfassen und zu behandeln. Abstract. Objective: 134 patients with acute myocardial infarction, who were treated in an intensive care unit (ICU) of a German hospital in Kiel between 1996 and 1999 were selected for the study to examine their psychologic symptoms. Patients and Methods: The patients were asked to fill in the self-report inventory, the Symptom Checklist-90-Revised (SCL-90-R) within the first 48 h after their arrival in the ICU. Results: Patients with a low social status were found to have elevated mean values of the following scales: somatization (0.93), depression (0.66), and anxiety (0.59). The Global Severity Index (GSI) as a global measure of psychologic distress was elevated as well (0.46). Conclusion: Since patients with a limited social network and low social status, increased anxiety and depressive scores have a poor prognosis as to their mortality and their professional reintegration, it it considered necessary for the prospective setting of this study to register particularly those patients in order to treat their anxiety.  相似文献   
22.
Fifty–five children 6–16 years old with allergic rhinoconjunctivitis due to both birch and grass pollinosis were randomized into 2 parallel groups, treated in double–blind fashion with either levocabastinc (LEV) eye–drops twice daily plus placebo eyedrops twice daily or sodium cromoglycate (SCG) eyedrops 4 times daily for 3 months. Spersallerg® (antazolini chloride + tetryzolini chloride) eyedrops were allowed as rescue medicine. All children received basic treatment with an antihistamine (terfenadine) during the complete trial period, and a local nasal corticosteroid if needed. Eye symptoms were recorded daily by the patients and at 4 visits by the investigator, at start and after 4, 10 and 13 weeks. Pollen counts were performed and a blood sample was collected at start and end of the treatment. The global evaluation of treatment was similar for the 2 groups, and there was no significant difference in any effect parameter except for the symptom, itchy eyes, which had lower score in the SCG group as evaluated by the investigator after 4 weeks. On days with low pollen counts the patients in the SCG group had fewer days with moderate or severe eye symptoms. It is concluded that even though LEV and SCG eyedrops were given in addition to systemic treatment with an antihistamine, no consistently significant differences in clinical effect were found between the 2 treatment groups, but the SCG group experienced slightly less eye symptoms throughout the trial. LEV eye–drops appear safe in long–term treatment in children, and no signs of tachyphylaxis were recorded.  相似文献   
23.
In the primate striatum, the tonically discharging neurons respond to conditioned stimuli associated with reward. We investigated whether these neurons respond to the reward itself and how changes in the behavioral context in which the reward is delivered might influence their responsiveness. A total of 286 neurons in the caudate nucleus and putamen were studied in two awake macaque monkeys while liquid reward was delivered in three behavioral situations: (1) an instrumental task, in which reward was delivered upon execution of a visually triggered arm movement; (2) a classically conditioned task, in which reward was delivered 1 s after a visual signal; (3) a free reward situation, in which reward was delivered at irregular time intervals outside of any conditioning task. The monkeys′ uncertainty about the time at which reward will be delivered was assessed by monitoring their mouth movements. A larger proportion of neurons responsive to reward was observed in the free reward situation (86%) than in the classically conditioned (57%) and instrumental tasks (37%). Among the neurons tested in all situations (n = 78), 24% responded to reward regardless of the situation and 65% in only one or two situations. Responses selective for one particular situation occurred exclusively in the free reward situation. When the reward was delivered immediately after the visual signal in the classically conditioned task, most of the neurons reduced or completely lost their responses to reward, and other neurons remained responsive. Conversely, neuronal responses invariably persisted when reward was delivered later than 1 s after the visual signal. This is the first report that tonic striatal neurons might display responses directly to primary rewards. The neuronal responses were strongly influenced by the behavioral context in which the animals received the reward. An important factor appears to be the timing of reward. These neurons might therefore contribute to a general aspect of behavioral reactivity of the subject to relevant stimuli. Received: 16 September 1996 / Accepted: 1 April 1997  相似文献   
24.
25.
Cutaneous manifestations of Lyme borreliosis   总被引:1,自引:0,他引:1  
Summary The dermatological symptoms of Lyme borreliosis present with a typical clinical pattern and characteristic time of appearance. In contrast to other manifestations of Lyme borreliosis they are easily recognizable in most of the cases. In the first stage, erythema migrans arises at the tick bite site. With this symptom the diagnosis of Lyme borreliosis can be established. During all manifestations of Lyme borreliosis the history of erythema migrans is an important parameter to verify the diagnosis. In the early stage of disease a lymphocytic proliferation can appear at the tick bite site, at the ear lobe, or at the mamilla. Borrelia lymphocytoma can be diagnosed when antibodies againstBorrelia burgdorferi are positive. Years after infection, acrodermatitis chronica atrophicans arises at distal body sites causing livid swelling and gradually skin atrophy. Skin lesions can be accompanied by neuropathies, mostly of the lower legs, which in contrast to the skin lesions, do not respond well to antibiotic therapy. There is evidence that some cases of Shulman syndrome, morphea and lichen sclerosus et atrophicus might be related to a borrelia infection as indicated by cultivation ofB. burgdorferi from skin biopsies of morphea and response to antibiotic treatment in some cases. The classical dermatological symptoms of Lyme borreliosis, erythema migrans, borrelia lymphocytoma and acrodermatitis chronica atrophicans respond to oral antibiotic treatment. In acrodermatitis chronica atrophicans parenteral antibiotic therapy is sometimes necessary.
Hautmanifestationen der Lyme-Borreliose
Zusammenfassung Dermatologische Manifestationen der Lyme-Borreliose zeichnen sich durch ihr charakteristisches Erscheinungsbild und durch den typischen Zeitpunkt ihres Auftretens aus und sind im Gegensatz zu anderen Symptomen meist gut zu diagnostizieren. Die Diagnose des Erythema chronicum migrans, das an der Zeckenstichstelle entsteht, erlaubt einerseits die exakte Diagnose einer Lyme-Borreliose und stellt in Spätstadien oft einen wichtigen anamnestischen Parameter zur Verifizierung einer durchgemachten Borrelieninfektion dar. Lymphozytäre Proliferationen können einerseits an der Zeckenstichstelle, andererseits auch an abstehenden Körperpartien beobachtet werden. Ein Borrelienlymphozytom kann dann diagnostiziert werden, wenn Antikörper gegenBorrelia burgdorferi nachweisbar sind. Die Acrodermatitis chronica atrophicans entsteht nach jahrelanger Latenz an abstehenden Körperpartien und führt zur Hautatrophie. Gelegentlich sind Begleitneuropathien möglich, welche im Gegensatz zu den Hautveränderungen auf die antibiotische Therapie nicht so gut ansprechen. Es gibt Berichte, wonach einige Fälle von Shulman Syndrom, Morphea und Lichen sclerosus et atrophicus auch durch eine Infektion mitB. burgdorferi verursacht werden. Die Isolierung vonB. burgdorferi aus Morphealäsionen dürfte dazu einen direkten Hinweis geben. Die klassischen dermatologischen Symptome Erythema chronicum migrans, Borrelienlymphozytom und Acrodermatitis chronica atrophicans sprechen auf orale antibiotische Therapie an. Bei letzterer Erkrankung muß manchmal auf eine parenterale antibiotische Therapie zurückgegriffen werden.
  相似文献   
26.
   Introduction
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