全文获取类型
收费全文 | 4253篇 |
免费 | 264篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 34篇 |
儿科学 | 149篇 |
妇产科学 | 99篇 |
基础医学 | 678篇 |
口腔科学 | 141篇 |
临床医学 | 328篇 |
内科学 | 1100篇 |
皮肤病学 | 35篇 |
神经病学 | 386篇 |
特种医学 | 102篇 |
外科学 | 664篇 |
综合类 | 24篇 |
预防医学 | 245篇 |
眼科学 | 44篇 |
药学 | 293篇 |
中国医学 | 13篇 |
肿瘤学 | 201篇 |
出版年
2023年 | 22篇 |
2022年 | 62篇 |
2021年 | 100篇 |
2020年 | 58篇 |
2019年 | 105篇 |
2018年 | 140篇 |
2017年 | 79篇 |
2016年 | 106篇 |
2015年 | 97篇 |
2014年 | 131篇 |
2013年 | 155篇 |
2012年 | 254篇 |
2011年 | 270篇 |
2010年 | 142篇 |
2009年 | 127篇 |
2008年 | 207篇 |
2007年 | 225篇 |
2006年 | 225篇 |
2005年 | 207篇 |
2004年 | 208篇 |
2003年 | 202篇 |
2002年 | 154篇 |
2001年 | 131篇 |
2000年 | 126篇 |
1999年 | 113篇 |
1998年 | 44篇 |
1997年 | 38篇 |
1996年 | 37篇 |
1995年 | 23篇 |
1994年 | 20篇 |
1993年 | 15篇 |
1992年 | 80篇 |
1991年 | 70篇 |
1990年 | 53篇 |
1989年 | 62篇 |
1988年 | 42篇 |
1987年 | 44篇 |
1986年 | 37篇 |
1985年 | 38篇 |
1984年 | 23篇 |
1983年 | 23篇 |
1982年 | 21篇 |
1980年 | 19篇 |
1979年 | 33篇 |
1978年 | 12篇 |
1977年 | 15篇 |
1974年 | 11篇 |
1973年 | 12篇 |
1967年 | 10篇 |
1966年 | 15篇 |
排序方式: 共有4536条查询结果,搜索用时 31 毫秒
101.
102.
R Chiavarelli G Macchiarelli G Familiari M Chiavarelli A Macchiarelli P Del Basso B Marino P M Motta 《The Thoracic and cardiovascular surgeon》1989,37(3):151-157
Coronary artery endothelial and myocardial ultrastructure was studied in guinea-pig heart-lung preparations (HLP) subjected to ischemic cardiac arrest induced by three hypothermic solutions. Two of the solutions used had high potassium chloride concentration ("Alabama" and "St. Thomas") while the third, instead, was a bicarbonate buffer (Kreb's solution). Five experimental groups were studied. In group 1 (control) the HLP were not subjected to cardiac arrest. Groups 2, 3, and 4 were subjected to a period of cardiac arrest of 30, 60, and 120 minutes respectively. In group 5, HLP were reperfused with blood for 30 minutes after 60 minutes of cardiac arrest. A thin ring of the left anterior descending coronary artery and myocardial fragments were obtained at the end of each experiment and were analyzed by means of transmission electron microscopy (TEM). Functional parameters were recorded in group 5. HLP perfused with Alabama solution showed a well-preserved endothelium and myocardium. HLP perfused with Krebs solution showed slight changes of the endothelial glycocalix only in group 4. Further, HLP perfused with Krebs solution showed extensive myocardial lesions (groups 3 and 4). These ischemic changes were not completely reversed after reperfusion (group 5). HLP perfused with St. Thomas solution showed only endothelial changes. These lesions were mainly characterized by: disappearance of the glycocalix and pynocytotic vesicles, endothelial cell bulging (group 2), and loss of the endothelial continuity (groups 3, 4, and 5). Hemodynamic parameters were significantly changed only in the Krebs-perfused HLP which showed a deterioration of the cardiac function related to the ischemic damage.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
103.
Clavio M Nobili F Balleari E Girtler N Ballerini F Vitali P Rosati P Venturino C Varaldo R Gobbi M Ghio R Rodriguez G 《European journal of haematology》2004,72(2):113-120
OBJECTIVE: In this prospective study we evaluate the effects of high-dose recombinant human erythropoietin (rHuEPO) on quality of life (QOL) and brain function in patients with low-risk myelodysplastic syndromes (MDS) (<10% marrow blasts). Preliminary data are reported. METHODS: Eleven consecutive patients were given rHuEPO (40,000 IU two times a week) for 12 wk. Responsive patients continued with 40,000 IU/wk for further 12 wk. Changes in QOL were assessed by the Functional Assessment of Cancer Therapy-Anemia (FACT-An) self-report. Neurophysiological evaluation at the start of the therapy (t0) included duplex scanning of neck vessels, transcranial Doppler sonography (TCD), a complex neuropsychological evaluation, and quantitative electroencephalography (qEEG). Eight patients completed the neurophysiological evaluation after 24 wk (t1). RESULTS: Six patients (55%) achieved an erythroid response after 12 wk, which was maintained after 24 wk of treatment. FACT-An score showed a relevant improvement between t0 and t1 in these patients. At baseline, TCD showed a mean cerebral blood flow (CBF) velocity in the upper normal range. Abnormalities in brain function were observed in five patients. In the eight patients who were re-evaluated at t1, improvement was observed in three responding patients, two of them with abnormal values at t0. A strict correlation between QOL and neurophysiological improvements was not observed. CONCLUSIONS: A high-dose induction phase with rHuEPO followed by maintenance therapy may be an effective therapeutic schedule for low-risk MDS patients. The erythroid response was associated with positive changes in the QOL. Neurophysiological improvements occurred only in a part (50%) of responding patients, mainly those who showed altered results at baseline. 相似文献
104.
Douglass A Morrison Gulshan Sethi Jerome Sacks William Henderson Frederick Grover Steven Sedlis Rick Esposito Kodagundi B Ramanathan Darryl Weiman J David Talley Jorge Saucedo Tamim Antakli Venki Paramesh Stuart Pett Sarah Vernon Vladimir Birjiniuk Frederick Welt Mitchell Krucoff Walter Wolfe John C Lucke Sundeep Mediratta David Booth Charles Barbiere Dan Lewis 《Journal of the American College of Cardiology》2002,39(2):266-273
OBJECTIVES: This study was designed to compare the three-year survival after percutaneous coronary intervention (PCI) or coronary artery bypass graft surgery (CABG) in physician-directed and patient-choice registries with the Angina With Extremely Serious Operative Mortality Evaluation (AWESOME) randomized trial results. BACKGROUND: The AWESOME multicenter randomized trial and registry compared the long-term survival after PCI and CABG for the treatment of patients with medically refractory myocardial ischemia and at least one additional risk factor for adverse outcome with CABG. The randomized trial demonstrated comparable three-year survival. METHODS: Over a five-year period (1995 to 2000), 2,431 patients with medically refractory myocardial ischemia and at least one of five risk factors (prior heart surgery, myocardial infarction within seven days, left ventricular ejection fraction <0.35, age >70 years, intra-aortic balloon required to stabilize) were identified. By physician consensus, 1,650 patients formed a physician-directed registry assigned to CABG (692), PCI (651) or further medical therapy (307), and 781 were angiographically eligible for random allocation; 454 of these patients constitute the randomized trial, and the remaining 327 constitute a patient choice registry. Survival for CABG and PCI was compared using Kaplan-Meier curves and log-rank tests. RESULTS: The CABG and PCI 36-month survival rates for randomized patients were 79% and 80%, respectively. The CABG and PCI 36-month survival rates were both 76% for the physician-directed subgroup; comparable survival rates for the patient-choice subgroup were 80% and 89%, respectively. None of the global log-rank tests for survival demonstrated significant differences. CONCLUSIONS: Both registries support the randomized trial conclusion: PCI is an alternative to CABG for some medically refractory high-risk patients. 相似文献
105.
106.
Ballestrero A Boy D Gonella R Miglino M Clavio M Barbero V Nencioni A Gobbi M Patrone F 《Annals of hematology》2008,87(1):49-55
To evaluate the safety and efficacy of pegfilgrastim administered as haematological support after autologous peripheral blood
stem cell transplantation, we compared 44 patients with solid tumours and lymphomas receiving a 6-mg single dose of pegfilgrastim
on day +5 after transplantation to a historical control group of 25 patients receiving filgrastim 5 μg kg−1 day−1 starting on day +5. There were no significant differences in haematological recovery nor in the incidence and duration of
neutropenic fever. Median duration of grade 4 neutropenia in the pegfilgrastim and filgrastim group was similar. The incidence
of grade III–IV mucositis was lower in pegfilgrastim than in filgrastim group due to the significant difference observed among
the patients with solid tumours (p = 0.00). The only adverse event considered to be cytokine related was mild to moderate bone pain occurring during haematological
recovery. According to the present study design and taking into account the current prices in our institution, the cost of
the two drugs was similar in both treatment groups. In conclusion, a single injection of pegfilgrastim administered at day
+5 post-transplantation shows comparable safety and efficacy profiles to daily injections of filgrastim and may be cost effective.
Alberto Ballestrero and Davide Boy contributed equally to this article. 相似文献
107.
108.
Devika Nair Kemberlee Bonnet Marcus G. Wild Ebele M. Umeukeje Rachel B. Fissell Marquetta L. Faulkner Nader S. Bahri Marino A. Bruce David G. Schlundt Kenneth A. Wallston Kerri L. Cavanaugh 《Journal of pain and symptom management》2021,61(1):32-41.e2
ContextPsychological distress is associated with adverse health outcomes in serious illness and magnified among patients of low socioeconomic status. Aspects of one's culture, such as religion and spirituality, can influence these patients' coping response to distress. Advanced chronic kidney disease (CKD) is a serious illness that disproportionately affects patients of low socioeconomic status, but a theory-based understanding of this group's lived experience of CKD is lacking.ObjectivesWe explored the cognitions, emotions, and coping behaviors of patients with CKD with emphasis on those of low socioeconomic status. We further inquired into any influences of religion or spirituality.MethodsWe interviewed 50 English-speaking or Spanish-speaking adults with advanced CKD from three medical centers in Nashville, Tennessee. Analyses occurred with isolation of themes; development of a coding system; and creation of a conceptual framework using an inductive-deductive approach.ResultsMedian age was 65 years; median annual income was $17,500 per year; and 48% of participants had not progressed beyond high school. Key beliefs (awareness of mortality and lack of control) influenced patients' emotions (existential distress in the form of death anxiety, prognostic uncertainty, and hopelessness) and coping behaviors (acceptance, avoidance, emotion regulation via spirituality, and seeking social support via a religious community).ConclusionIndividuals with advanced CKD and low socioeconomic status lack control over disease progression, experience death anxiety and existential distress, and emphasize spirituality to cope. Our study identifies novel components for a psychotherapeutic intervention for patients with advanced CKD at high risk for adverse health outcomes. 相似文献
109.
Maurizio Bellavia Giovanni Tomasello Marcello Romeo Provvidenza Damiani Attilio I. Lo Monte Luciano Lozio Claudia Campanella Antonella Marino Gammazza Francesca Rappa Giovanni Zummo Massimo Cocchi Everly Conway de Macario Alberto J. L. Macario Francesco Cappello 《Medical microbiology and immunology》2013,202(6):393-406
In this work, we propose that for further studies of the physiopathology and treatment for inflammatory bowel diseases, an integral view of the conditions, including the triad of microbiota–heat shock proteins (HSPs)–probiotics, ought to be considered. Microbiota is the complex microbial flora that resides in the gut, affecting not only gut functions but also the health status of the whole body. Alteration in the microbiota’s composition has been implicated in a variety of pathological conditions (e.g., ulcerative colitis, UC), involving both gut and extra-intestinal tissues and organs. Some of these pathologies are also associated with an altered expression of HSPs (chaperones) and this is the reason why they may be considered chaperonopathies. Probiotics, which are live microorganisms able to restore the correct, healthy equilibrium of microbiota composition, can ameliorate symptoms in patients suffering from UC and modulate expression levels of HSPs. However, currently probiotic therapy follows ex-adiuvantibus criteria, i.e., treatments with beneficial effects but whose mechanism of action is unknown, which should be changed so the probiotics needed in each case are predetermined on the basis of the patient’s microbiota. Consequently, efforts are necessary to develop diagnostic tools for elucidating levels and distribution of HSPs and the microbiota composition (microbiota fingerprint) of each subject and, thus, guide specific probiotic therapy, tailored to meet the needs of the patient. Microbiota fingerprinting ought to include molecular biology techniques for sequencing highly conserved DNA, e.g., genes encoding 16S RNA, for species identification and, in addition, quantification of each relevant microbe. 相似文献
110.
Alastair J. Flint Anthony J. Rothschild Ellen M. Whyte George S. Alexopoulos Benoit H. Mulsant Patricia Marino Samprit Banerjee Cristina D. Pollari Yiyuan Wu Aristotle N. Voineskos Barnett S. Meyers 《The American journal of geriatric psychiatry》2021,29(7):645-654
ObjectiveTo examine the effect of older versus younger age on change in anthropometric and metabolic measures during extended treatment of psychotic depression with sertraline plus olanzapine.MethodsTwo hundred and sixty-nine men and women aged 18–85 years with an episode of psychotic depression were treated with open-label sertraline plus olanzapine for up to 12 weeks. Participants who remained in remission following an 8-week stabilization phase were eligible to participate in a 36-week randomized controlled trial (RCT) that compared the efficacy and tolerability of sertraline plus olanzapine with sertraline plus placebo. Weight, waist circumference and plasma lipids, glucose, HbA1c, and insulin were measured at regular intervals during the acute, stabilization and randomized phases of the study. Linear mixed models were used to analyze the trajectories of anthropometric and metabolic measures.ResultsParticipants aged 60 years or older experienced less weight gain and less increase in cholesterol during the combined acute and stabilization phases of the study compared with those aged 18–59 years. At the acute-stabilization termination visit, mean weight in older participants was 6.5 lb. less than premorbid weight, whereas it was 17.9 lb. more than premorbid weight in younger participants. In the RCT, there was a significant interaction of treatment and age group for the trajectory of weight, but the post hoc tests that compared age groups within each treatment arm were not statistically significant. There were no clinically significant differences between younger and older participants in glycemic measures.ConclusionOlder patients with psychotic depression experienced less increase in weight and total cholesterol than their younger counterparts during acute and stabilization treatment with sertraline plus olanzapine. In the older group, weight gained during the acute and stabilization phases appeared to be partial restoration of weight lost during the index episode of depression, whereas weight gain in younger participants was not. 相似文献