全文获取类型
收费全文 | 41216篇 |
免费 | 2389篇 |
国内免费 | 206篇 |
专业分类
耳鼻咽喉 | 386篇 |
儿科学 | 760篇 |
妇产科学 | 683篇 |
基础医学 | 5680篇 |
口腔科学 | 1074篇 |
临床医学 | 4012篇 |
内科学 | 8594篇 |
皮肤病学 | 942篇 |
神经病学 | 4445篇 |
特种医学 | 2367篇 |
外国民族医学 | 1篇 |
外科学 | 6567篇 |
综合类 | 226篇 |
一般理论 | 10篇 |
预防医学 | 1869篇 |
眼科学 | 846篇 |
药学 | 2522篇 |
中国医学 | 75篇 |
肿瘤学 | 2752篇 |
出版年
2023年 | 290篇 |
2022年 | 540篇 |
2021年 | 939篇 |
2020年 | 694篇 |
2019年 | 872篇 |
2018年 | 1091篇 |
2017年 | 910篇 |
2016年 | 1066篇 |
2015年 | 1317篇 |
2014年 | 1559篇 |
2013年 | 1859篇 |
2012年 | 3038篇 |
2011年 | 3203篇 |
2010年 | 1911篇 |
2009年 | 1653篇 |
2008年 | 2698篇 |
2007年 | 2687篇 |
2006年 | 2591篇 |
2005年 | 2491篇 |
2004年 | 2279篇 |
2003年 | 2059篇 |
2002年 | 1991篇 |
2001年 | 551篇 |
2000年 | 503篇 |
1999年 | 548篇 |
1998年 | 391篇 |
1997年 | 299篇 |
1996年 | 235篇 |
1995年 | 200篇 |
1994年 | 168篇 |
1993年 | 156篇 |
1992年 | 190篇 |
1991年 | 170篇 |
1990年 | 161篇 |
1989年 | 150篇 |
1988年 | 129篇 |
1987年 | 116篇 |
1986年 | 127篇 |
1985年 | 109篇 |
1984年 | 93篇 |
1983年 | 77篇 |
1982年 | 77篇 |
1979年 | 82篇 |
1975年 | 71篇 |
1974年 | 83篇 |
1973年 | 72篇 |
1972年 | 76篇 |
1971年 | 71篇 |
1969年 | 76篇 |
1967年 | 69篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
43.
44.
Andreas C Eriksson Per A Whiss Ulrika K Nilsson 《Blood coagulation & fibrinolysis》2006,17(5):359-368
Lysophosphatidic acid (LPA) and adrenaline are weak platelet activators considered important for thrombus formation, and were previously shown to synergistically increase platelet aggregation. Here we investigate synergistic activation by LPA and adrenaline when measuring platelet adhesion. Platelet-rich plasma from healthy blood donors together with adrenaline and/or LPA were added to protein-coated microplates. Platelets were allowed to adhere and the amount of adhesion detected enzymatically. The LPA and adrenaline combination induced a synergistic increase of platelet adhesion to a normally non-adhesive albumin surface. The degree of synergy varied markedly between individuals; these variations could not be explained by age, gender, blood type or different amounts of platelets, oxidized low-density lipoprotein, insulin or glucose in plasma. There was a trend indicating increased synergistic effect for platelets sensitive to adrenaline stimulation. The synergistic effect was blocked by the alpha2-adrenoceptor antagonist yohimbine and inhibited by the ADP scavenger system creatine phosphate/creatine phosphokinase and antibodies against alphaIIbbeta3. Furthermore, platelets adhering to albumin after adrenaline and LPA treatment expressed P-selectin. In conclusion, LPA and adrenaline act synergistically to increase alphaIIbbeta3-mediated platelet adhesion to albumin, dependent on alpha2-adrenoceptor signalling and platelet secretion. We also confirm that synergistic platelet activation achieved with LPA and adrenaline is highly donor dependent. 相似文献
45.
The authors draw attention to possible extraocular changes in children with congenital aniridia. Of 31 investigated patients they were found in 5 children. Among these changes, because of its serious character, Wilms tumour holds the first place; it was found by the authors in two children. To ensure its early detection, the authors emphasize the necessity to dispensarize all children with congenital aniridia. Collaboration with an experienced X-ray specialist and child oncologist is essential. In addition to Wilms' tumour congenital aniridia can be associated with serious somatic developmental changes. The authors observed in one child and AGR triad and in two patients deformities of the skeleton of the head and lower extremities. 相似文献
46.
Sex, socioeconomic status, intelligence, a clinical symptom score, and an index of abnormal psychosocial situations as proposed by a recent WHO draft were studied as correlates of the Global Assessment of Functioning Scale (GAFS), which comprises Axis V of theDSM-III-R. Whereas all parameters correlated significantly with the GAFS score, only total symptom domain score displayed a meaningful association. It was concluded that the GAFS contributes significantly to clinical information as an independent source.
Zusammenfassung Es wurden ein klinischer Symptomwert, ein Index für abnorme psychosoziale Situationen gemäß einem unlängst erschienenen WHO-Dokument, Geschlecht, sozioökonomischer Status und Intelligenz als Korrelate der Global Assessment of Functioning Scale (GAFS) untersucht, welche die Achse V des DSM-III-R bildet. Während alle Parameter
Résumé Le sexe, le statut socio-économique, l'intelligence, le score des symptômes cliniques, et un index de situations psychosociales anormales proposés par un récent projet del'OMS furent étudiés en corrélation avec l'évaluation globale de l'échelle de fonctionnement (Global Assessment of Functioning Scale G.A.F.S.) qui correspond à l'axe V du DSM III R. Tandis que tous les paramètres sont corrélés significativement avec un score GAFS, seul le score symptomatique total n'offre pas d'association significative. Les auteurs ont conclu que le GAFS contribue significativement à l'information clinique en tant que source indépendante.相似文献
47.
Dieter Schilling Peter Messerer M. Gerald Ott Peter Schauwecker Andreas Zober Jürgen F. Riemann 《Medizinische Klinik》2002,12(2):6-11
Zusammenfassung Hintergrund: Die Assoziation zwischen Helicobacter-pylori-(H.-pylori-)Infektion und Dyspepsie wird kontrovers diskutiert. Im Rahmen der BASF-H.-pylori-Vorsorgeaktion wurde u. a. die Prävalenz von Dyspepsie bei arbeitsfähigen Personen ermittelt sowie der Zusammenhang mit der H.-pylori-Infektion und der Erfolg einer Eradikationstherapie untersucht. Probanden und Methodik: 6 132 Beschäftigte der BASF wurden untersucht und im Rahmen einer standardisierten Anamnese u. a. zu dyspeptischen Beschwerden befragt. Diese wurden entsprechend der führenden Symptomatik den Dyspepsiesubtypen vom Ulkustyp, Dysmotilitätstyp, Refluxtyp und unspezifischen Typ zugeordnet. Bei allen Beschäftigten wurde die Seroprävalenz (IgG-ELISA) der H.-pylori-Infektion bestimmt. Allen H.-pylori-positiven Personen mit Dyspepsie wurde weitere Diagnostik in Form einer Ösophagogastroduodenoskopie und einer Sonographie des Abdomens bei Fachärzten empfohlen und eine H.-pylori-Eradikationstherapie (Italian-Triple-Therapie) angeboten. In einer Untergruppe endoskopisch untersuchter Beschäftigter mit peptischer Ulkuskrankheit (PUD, n = 37) bzw. Non-Ulcer-Dyspepsie (NUD; n = 39) wurde der prognostische Wert der im Western Blot ermittelten Antikörper gegen CagA und VacA untersucht. Ergebnisse: 1 255 der 6 143 Beschäftigten (20,4%) berichteten über Dyspepsie. 492 Personen mit Dyspepsie (39,2%) waren gleichzeitig H.-pylori-positiv. Bei Personen ohne dyspeptische Symptome betrug die H.-pylori-Prävalenz 35,8%. Personen mit unterschiedlichen Dyspepsiesubtypen unterschieden sich nicht hinsichtlich der H.-pylori-Prävalenz. Personen, die häufige und intensive dyspeptische Beschwerden angaben, waren allerdings signifikant häufiger H.-pylori-positiv (OR 2,09, CI 1,43-3,05). Die Seroprävalenz von CagA und VacA bei Personen mit PUD unterschied sich nicht signifikant von derjenigen bei Personen mit NUD. 458 H.-pylori-positiven Personen wurde die Eradikation empfohlen. 330 Personen (72,1%) folgten der Empfehlung. 128 (27,9%) ließen sich nicht behandeln. An der Nachkontrolle nach 12 Monaten nahmen 402 Personen (87,8%) teil, davon waren 300 behandelt, 102 nicht. Der serologisch analysierte Eradikationserfolg lag bei 81,5%. 42,8% der erfolgreich behandelten Personen berichteten über Besserung ihrer Beschwerden, 33,2% über Beschwerdefreiheit. Bei den nicht behandelten Personen war dies nur in 16,7% bzw. in 37,3% der Fall. Vermehrte Refluxbeschwerden traten nach erfolgreicher Eradikation nicht auf. Schlussfolgerung: Wir konnten keinen generellen Zusammenhang zwischen Dyspepsie und H.-pylori-Infektion in einem großen Kollektiv arbeitsfähiger Personen erkennen. Häufige und intensive dyspeptische Symptome scheinen allerdings ein prädikativer Faktor für die H.-pylori-Seropositivität zu sein. Die serologisch bestimmbaren Virulenzfaktoren tragen nicht zur Unterscheidung PUD oder NUD bei. Die Eradikationstherapie führte nach 1 Jahr zwar häufiger zur Besserung, aber nicht häufiger zu Beschwerdefreiheit bei Beschäftigten mit dyspeptischen Beschwerden im Vergleich zu unbehandelten Personen. Abstract Background: The role of Helicobacter pylori (H. pylori) infection in dyspepsia is controversial. In the course of a health initiative within a large industrial corporation, we investigated the prevalence of both dyspepsia and positive H. pylori serology and the outcome of eradication therapy in symptomatic H. pylori positive employees. Test Persons and Methods: H. pylori serology (IgG ELISA) was determined in 6,143 employees of BASF AG Ludwigshafen/Germany who were also asked to complete a standardized health history administered by a physician. Peptic ulcer disease (PUD) and dyspepsia subgroups were defined based on past medical history and symptom profiles using the criteria of Heading. Upper GI endoscopy, abdominal ultrasound and eradication therapy (Italian Triple Therapy) was recommended for symptomatic H. pylori positive individuals. The prognostic value of antibodies against CagA and VacA was evaluated in 37 and 39 employees with PUD and non-ulcer dyspepsia (NUD) confirmed by endoscopy, respectively. Results: Of 6,143 employees, 1,255 (20.4%) were classified as dyspeptic, 492 (39.2%) of whom were H. pylori positive. The seroprevalence of H. pylori in asymptomatic employees was 35.8%. There were no significant differences in H. pylori seroprevalence among dyspepsia subgroups (reflux only, dysmotility only, reflux/dysmotility, ulcer-like and non-specific). However, individuals reporting severe dyspeptic symptoms were significantly more likely to be H. pylori positive (OR 2.09, CI 1.43-3.05). The seroprevalence of CagA and VacA was not significantly different among employees with NUD compared to referents or among employees with NUD compared to those with PUD. 330 (72%) of 458 employees with dyspepsia received eradication therapy, 128 persons refused therapy. Based on a 12-month follow-up of 402 individuals (300 of whom had received therapy), eradication success was 81.5% as judged by serology. Of the successfully treated employees, 33.2% reported a total absence and 42.8% reported a decrease in symptoms. Among the employees who refused therapy, the corresponding percentages were 37.3% and 16.7%, respectively. An increase in reflux complaints was not observed among treated employees. Conclusion: In a large active employee population, at most a very weak association was observed between the prevalence of H. pylori seropositivity and dyspepsia. Frequent and severe dyspeptic symptoms were associated with an increased rate of H. pylori seropositivity. The analysis of the virulence factors is not particularly helpful in discriminating PUD or NUD. Eradication of H. pylori infection leads to a decrease in dyspeptic symptoms after 12 months, but not more often to their complete absence compared to untreated individuals. 相似文献
48.
In a twelve-year investigation the authors compare the results of three types of weakening operations of the inferior oblique muscle in 298 eyes. The evaluation lead to their views regarding indications of different surgical techniques. In their opinion the best operation is triple partial myotomy of the inferior oblique muscle as it does not influence the horizontal position and preserves the original insertion of the muscle. They modify the techniques of Romer-Apis and Martinez-Oropeza. Fixation of the inferior and external rectus on hooks reveals the surgical field, and the concurrent stretching of the inferior oblique muscle beneath the conjunctiva facilitates its dissection. The authors include triple partial myotomy except for hypertropias in the comprehensive surgical procedure together with plication of the ipsilateral superior oblique muscle in paresis of the trochlear nerve. They indicate retroposition of the inferior oblique muscle only in divergence associated with hyperfunction of the inferior oblique muscle. The operation has a favourable effect on convergent synkinesis and enhances convergence by +2 to +5 degrees. The authors consider free myectomy of the inferior oblique muscle the least physiological operation and use it no longer. 相似文献
49.
Stefanie Klaffke Andrea A Kuhn Michail Plotkin Holger Amthauer Daniel Harnack Roland Felix Andreas Kupsch 《Movement disorders》2006,21(10):1724-1727
Alterations in presynaptic and postsynaptic dopaminergic system and cerebral glucose metabolism in corticobasal degeneration (CBD) were assessed to evaluate the potential usefulness of different imaging methods for CBD. (123)I-FP-CIT/(123)I-beta-CIT SPECT and (123)I-IBZM SPECT as well as (18)F-FDG PET were performed in eight CBD patients. Decreased presynaptic dopamine transporter binding was found in all CBD patients while D2 receptor binding was reduced in only one patient. (18)F-FDG PET displayed a contralateral hypometabolism in cortical and subcortical areas in seven out of eight patients. Our results demonstrate that glucose metabolism and DAT are reduced, while D2 receptors may be frequently preserved in CBD. 相似文献