全文获取类型
收费全文 | 1700篇 |
免费 | 59篇 |
国内免费 | 80篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 49篇 |
妇产科学 | 11篇 |
基础医学 | 233篇 |
口腔科学 | 21篇 |
临床医学 | 223篇 |
内科学 | 471篇 |
皮肤病学 | 29篇 |
神经病学 | 140篇 |
特种医学 | 333篇 |
外科学 | 59篇 |
综合类 | 21篇 |
预防医学 | 39篇 |
眼科学 | 34篇 |
药学 | 103篇 |
肿瘤学 | 47篇 |
出版年
2023年 | 9篇 |
2021年 | 4篇 |
2020年 | 12篇 |
2019年 | 13篇 |
2018年 | 16篇 |
2017年 | 10篇 |
2016年 | 21篇 |
2015年 | 18篇 |
2014年 | 28篇 |
2013年 | 36篇 |
2012年 | 45篇 |
2011年 | 36篇 |
2010年 | 46篇 |
2009年 | 55篇 |
2008年 | 51篇 |
2007年 | 95篇 |
2006年 | 44篇 |
2005年 | 72篇 |
2004年 | 57篇 |
2003年 | 72篇 |
2002年 | 66篇 |
2001年 | 76篇 |
2000年 | 51篇 |
1999年 | 63篇 |
1998年 | 74篇 |
1997年 | 79篇 |
1996年 | 52篇 |
1995年 | 70篇 |
1994年 | 41篇 |
1993年 | 43篇 |
1992年 | 30篇 |
1991年 | 34篇 |
1990年 | 29篇 |
1989年 | 43篇 |
1988年 | 43篇 |
1987年 | 34篇 |
1986年 | 31篇 |
1985年 | 48篇 |
1984年 | 25篇 |
1983年 | 21篇 |
1982年 | 28篇 |
1981年 | 16篇 |
1980年 | 26篇 |
1979年 | 5篇 |
1978年 | 7篇 |
1977年 | 16篇 |
1976年 | 16篇 |
1975年 | 13篇 |
1974年 | 4篇 |
1973年 | 3篇 |
排序方式: 共有1839条查询结果,搜索用时 31 毫秒
11.
Chronic exposure of humans to benzene (BZ), a myelotoxin, causes aplastic anemia and acute leukemia. The stromal macrophage that produces interleukin-1 (IL-1), a cytokine essential for hematopoiesis, is a target of BZ's toxicity. Monocyte dysfunction and decreased IL-1 production have been shown to be involved in aplastic anemia in humans. Hydroquinone (HQ), a toxic bone marrow (BM) metabolite of BZ, causes time- and concentration-dependent inhibition of processing of the 34-Kd pre-interleukin-1 alpha (IL-1 alpha) to the 17-Kd mature cytokine in murine P388D1 macrophages and BM stromal macrophages, as measured by Western immunoblots of cell lysate proteins using a polyclonal rabbit antimurine IL-1 alpha antibody. HQ over a 10-fold concentration range had no effect on the lipopolysaccharide (LPS)-induced production of pre- IL-1 alpha precursor or on cell viability or DNA and protein synthesis. Stromal macrophages obtained from the femoral BM of C57Bl/6 mice exposed to BZ (600 or 800 mg/kg body weight) for 2 days were incapable of processing the 34-Kd pre-IL-1 alpha to the mature 17-Kd cytokine when stimulated in culture with LPS. Stromal macrophages from mice coadministered BZ and indomethacin, a prostaglandin H synthase (PHS) inhibitor that has been shown to prevent BZ-induced myelotoxic and genotoxic effects in mice when coadministered with benzene were able to convert the pre-IL-1 alpha to mature cytokine. Administration of recombinant murine IL-1 alpha (rMuIL-1 alpha) to mice before a dose of BZ that causes severe depression of BM cellularity completely prevents BM depression, most probably by bypassing the inability of the stromal macrophage in BZ-treated animals to process pre-IL-1 alpha to the mature cytokine. 相似文献
12.
A shortened latency of rapid eye movement (REM) sleep is one of the most stable biological abnormalities described in depressive patients. According to the reciprocal interaction model of non-REM and REM sleep regulation, REM sleep disinhibition at the beginning of the night in depression is a consequence of heightened central nervous system cholinergic transmitter activity in relation to aminergic transmitter activity. A recent study has indicated that muscarinic supersensitivity, rather than quantitatively enhanced cholinergic activity, may be the primary cause of REM sleep abnormalities in depression. The present study tested this hypothesis by treating healthy volunteers for 3 days with a cholinergic antagonist (scopolamine) in the morning, in an effort to induce muscarinic receptor supersensitivity. On the last day of scopolamine administration, RS 86, an orally active cholinergic agonist, was administered before bedtime to test whether this procedure would induce sleep onset REM periods. Whereas scopolamine treatment tended to advance REM sleep and to heighten REM density in healthy controls in comparison to NaCl administration, the additional cholinergic stimulation did not provoke further REM sleep disinhibition. This result underlines the need to take a hypofunction of aminergic transmitter systems into account in attempts to explain the pronounced advance of REM sleep typically seen in depressives. 相似文献
13.
Pernes JM; Vitoux JF; Brenoit P; Raynaud A; Parola JL; Roth JP; Angel CY; Fiessinger JN; Roncato M; Gaux JC 《Radiology》1986,158(2):481-485
Thirty-five patients hospitalized for recent angiographically documented arterial occlusion in the legs (27 femoropopliteal arteries and eight grafts) benefited from local fibrinolytic therapy delivered at the site of the occlusion with a 4- or 5-F catheter. This therapy combined a continuous urokinase (UK) infusion of 1,000 U/kg/hour and a lysyl plasminogen (LYS-PLG) infusion of 15 microkatals every 30 minutes. Angiographically confirmed lysis was obtained in 85% of the cases. Only 3% of the patients had major and 6% had minor groin hematomas. Only two patients had concentrations of fibrinogen as low as 100 mg/dl. Intravascular infusion of UK-LYS-PLG is as effective as streptokinase. Its excellent tolerance makes it a good alternative in the treatment of acute ischemia in the lower limbs. 相似文献
14.
Raoul JL; Bourguet P; Bretagne JF; Duvauferrier R; Coornaert S; Darnault P; Ramee A; Herry JY; Gastard J 《Radiology》1988,168(2):541-545
Biodistribution of iodine-131-labeled Lipiodol Ultra-Fluide (I-131 LUF) injected into the hepatic artery was studied scintigraphically in 47 patients with hepatocellular carcinoma (n = 23), hepatic metastases (n = 14), or normal livers (n = 10). The investigation was extremely well tolerated. I-131 LUF concentrated mainly in the liver (L) and the lungs (l), with L/L + l activity ratios greater than 75% for all three groups of patients. I-131 LUF distribution was homogeneous in normal livers and heterogeneous in cirrhotic livers. I-131 LUF concentrated in the tumor with a tumorous (T) to nontumorous (NT) activity ratio (T/NT) of 4.3 +/- 3.6 for hepatocellular carcinoma and 2.4 +/- 0.7 for hepatic metastases. The effective half-life of I-131 LUF is more than 4.5 days for the three groups. It was eliminated mainly through the urine. Clearance from tumor is slower than from normal liver, as shown by the increase in T/NT at day 18. Biodistribution did not change in patients who had a second injection, which indicates that there is no saturation phenomenon. The results of this study suggest that LUF may be considered as a potential carrier vehicle for therapeutic agents. 相似文献
15.
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
16.
Ohne Zusammenfassung 相似文献
17.
18.
Magdolna Hornyak Hans-Peter Hundemer Deborah Quail Dieter Riemann Ulrich Voderholzer Claudia Trenkwalder 《Clinical neurophysiology》2007,118(7):1532-1537
OBJECTIVE: To evaluate the relationship of the severity of restless legs syndrome (RLS) as assessed by a subjective, patient-rated scale (International RLS Study Group Rating Scale, IRLS), and of periodic leg movements in sleep (PLMS) as an objective parameter, in two different patient populations. METHODS: Data of 200 unmedicated patients with idiopathic RLS were evaluated. Group 1 (n=100) consisted of selected patients participating in the Pergolide European Australian RLS (PEARLS) study. Group 2 (n=100) represented an outpatient RLS population investigated in a Sleep Disorders Center. Additionally, Group 1 was also evaluated after a 6 week double-blind treatment period, where 47 patients received pergolide and 53 patients placebo. RESULTS: In unmedicated patients, IRLS scores correlated with the PLMS-arousal index (r=0.22, p=0.033) but not with the PLMS index in Group 1 while no correlation was found in Group 2. The change of the IRLS score under treatment in Group 1 correlated significantly both with the change of the PLMS index (r=0.42, p<0.001) and the change of the PLMS-arousal index (r=0.38, p<0.001). CONCLUSIONS: The IRLS adequately reflects treatment changes of PLMS indices. In unmedicated patients, the IRLS correlates with PLMS indices probably only in selected RLS populations with predefined PSG criteria and high PLM activity. SIGNIFICANCE: The IRLS is an appropriate subjective rating scale for measuring treatment effects in RLS. 相似文献
19.
Intestinal obstruction proximal to a transition zone without an interposed physical barrier usually indicates Hirschsprung disease. The authors report one case of focal small bowel muscular thinning just distal to a transition zone that produced clinical and radiographic findings that simulated long-segment Hirschsprung disease in a 2-day-old infant. 相似文献
20.