全文获取类型
收费全文 | 9368篇 |
免费 | 529篇 |
国内免费 | 47篇 |
专业分类
耳鼻咽喉 | 87篇 |
儿科学 | 279篇 |
妇产科学 | 211篇 |
基础医学 | 1240篇 |
口腔科学 | 196篇 |
临床医学 | 668篇 |
内科学 | 2406篇 |
皮肤病学 | 166篇 |
神经病学 | 1132篇 |
特种医学 | 390篇 |
外科学 | 1020篇 |
综合类 | 13篇 |
一般理论 | 1篇 |
预防医学 | 607篇 |
眼科学 | 116篇 |
药学 | 607篇 |
中国医学 | 12篇 |
肿瘤学 | 793篇 |
出版年
2023年 | 77篇 |
2022年 | 77篇 |
2021年 | 242篇 |
2020年 | 152篇 |
2019年 | 176篇 |
2018年 | 406篇 |
2017年 | 288篇 |
2016年 | 285篇 |
2015年 | 324篇 |
2014年 | 359篇 |
2013年 | 533篇 |
2012年 | 605篇 |
2011年 | 497篇 |
2010年 | 389篇 |
2009年 | 348篇 |
2008年 | 488篇 |
2007年 | 471篇 |
2006年 | 457篇 |
2005年 | 437篇 |
2004年 | 439篇 |
2003年 | 340篇 |
2002年 | 337篇 |
2001年 | 182篇 |
2000年 | 137篇 |
1999年 | 245篇 |
1998年 | 64篇 |
1997年 | 56篇 |
1996年 | 36篇 |
1995年 | 35篇 |
1994年 | 33篇 |
1993年 | 35篇 |
1992年 | 126篇 |
1991年 | 133篇 |
1990年 | 108篇 |
1989年 | 111篇 |
1988年 | 104篇 |
1987年 | 103篇 |
1986年 | 73篇 |
1985年 | 71篇 |
1984年 | 60篇 |
1983年 | 47篇 |
1982年 | 25篇 |
1979年 | 47篇 |
1978年 | 23篇 |
1976年 | 41篇 |
1974年 | 21篇 |
1973年 | 35篇 |
1972年 | 25篇 |
1971年 | 26篇 |
1968年 | 20篇 |
排序方式: 共有9944条查询结果,搜索用时 15 毫秒
971.
F Schaefer D Borzych-Duzalka M Azocar RL Munarriz L Sever N Aksu LS Barbosa YS Galan H Xu PA Coccia A Szabo W Wong R Salim E Vidal S Pottoore BA Warady;the IPPN investigators 《Peritoneal dialysis international》2012,32(4):399-409
Background, Objectives, and METHODS: The number of patients on chronic peritoneal dialysis (CPD) is increasing rapidly on a global scale. We analyzed the International Pediatric Peritoneal Dialysis Network (IPPN) registry, a global database active in 33 countries spanning a wide range in gross national income (GNI), to identify the impact of economic conditions on CPD practices and outcomes in children and adolescents. ? RESULTS: We observed close associations of GNI with the fraction of very young patients on dialysis, the presence and number of comorbidities, the prevalence of patients with unexplained causes of end-stage kidney disease, and the rate of culture-negative peritonitis. The prevalence of automated PD increased with GNI, but was 46% even in the lowest GNI stratum. The GNI stratum also affected the use of biocompatible peritoneal dialysis fluids, enteral tube feeding, calcium-free phosphate binders, active vitamin D analogs, and erythropoiesis-stimulating agents (ESAs). Patient mortality was strongly affected by GNI (hazard ratio per $10 000: 3.3; 95% confidence interval: 2.0 to 5.5) independently of young patient age and the number of comorbidities present. Patients from low-income countries tended to die more often from infections unrelated to CPD (5 of 9 vs 15 of 61, p = 0.1). The GNI was also a strong independent predictor of standardized height (p < 0.0001), adding to the impact of congenital renal disease, anuria, age at PD start, and dialysis vintage. Patients from the lower economic strata (GNI < $18 000) had higher serum parathyroid hormone (PTH) and lower serum calcium, and achieved lower hemoglobin concentrations. No impact of GNI was observed with regard to CPD technique survival or peritonitis incidence. ? CONCLUSIONS: We conclude that CPD is practiced successfully, albeit with major regional variation related to economic differences, in children around the globe. The variations encompass the acceptance of very young patients and those with associated comorbidities to chronic dialysis programs, the use of automated PD and expensive drugs, and the diagnostic management of peritonitis. These variations in practice related to economic difference do not appear to affect PD technique survival; however, economic conditions seem to affect mortality on dialysis and standardized height, a marker of global child morbidity. 相似文献
972.
973.
Joaquín Tomás-Sábado Montserrat Maynegre-Santaulària Meritxell Pérez-Bartolomé Marta Alsina-Rodríguez Roser Quinta-Barbero Sergi Granell-Navas 《Enfermería clínica》2010,20(3):173-178
ObjectiveTo observe the prevalence of the burnout syndrome and the relationship with suicide risk, self-esteem, anxiety and depression, in a sample of primary care nurses.MethodObservational, cross-sectional and correlational study. The sample consisted of 146 nursing professionals, 131 women and 15 men, with an average age of 44.02 years (SD=10.89). Participants responded to a questionnaire which included the Spanish forms of the Maslach burnout inventory (MBI), the Plutchik Suicide Risk Scale (SR), the Kuwait University Anxiety Scale (KUAS), the Self-Rating Depression Scale (SDS) and the Rosenberg Self-esteem Scale (RSES). In the inferential statistical analysis, Pearson's r coefficients and multiple linear regression were calculated.ResultsSignificant correlations between suicidal risk and anxiety, depression, self-esteem, emotional exhaustion and personal performance, were obtained. In the multiple regression analysis, depression was the main predictor of suicidal risk, followed by anxiety and emotional exhaustion.ConclusionsThe scores obtained in burnout and suicidal risk were, in general, lower than those observed in other studies, emphasising the high level observed in personal performance, which reflects reasonable professional satisfaction. The results show the important role of working atmosphere and early recognition of mental disorders in burnout and suicidal risk prevention. 相似文献
974.
975.
Antonello D'Andrea M.D. F.E.S.C. Sergio Severino M.D. F.E.S.C. † Claudia Mita M.D. Lucia Riegler M.D. Rosangela Cocchia M.D. Rita Gravino M.D. Francesca Castaldo M.D. Raffaella Scarafile M.D. Gemma Salerno M.D. Sergio Pirone M.D. Paolo Calabrò M.D. F.E.S.C. Maurizio Cappelli Bigazzi M.D. Rodolfo Citro M.D. ‡ Sergio Cuomo M.D. F.E.S.C. Pio Caso M.D. F.E.S.C. † Raffaele Calabrò M.D. 《Echocardiography (Mount Kisco, N.Y.)》2009,26(4):431-440
Background: Several reports suggest that noninvasive measurements of coronary flow reserve (CFR) by use of echocardiography may support decision making in intermediate stenosis of the left anterior descending coronary artery (LAD). The aim of the present study was therefore to analyze the clinical outcome in patients with intermediate stenosis of LAD after deferral of coronary revascularization on the basis of noninvasive CFR measurement. Methods: the study population included 280 patients with intermediate LAD stenosis (50–70% by angiography) (62.2 ± 9.6 years). All the patients underwent transthoracic CFR assessment of LAD (after dipyridamole infusion) within 2 weeks from coronary angiography. If CFR of LAD was ≤ 2, PTCA was recommended; if CFR was > 2, medical treatment was chosen. Primary end points were cardiac death, myocardial infarction, coronary revascularization procedure, and unstable angina. Results: mean follow-up was 43 ± 11 months (range 12–52 months). In 150 patients (53.6%) (CFR ≤ 2), coronary artery revascularization was performed (PTCA group); the remaining 130 patients (46.4%) (CFR > 2) were medically treated (medical group). Survival from cardiac death was 94% in the PTCA group and 92.4% in the medical group (P = 0.56). As for all cardiac events, the Kaplan–Meier percentage survival from cardiac events was 88.3% in the PTCA group and 86.4% in the medical group (P = 0.36). Conclusions: even if CFR as a "stand-alone" diagnostic criterion suffers from several structural limitations, a combined strategy including also other clinical and instrumental measurements before undergoing interventional procedures could improve the cost–benefit practice, in particular, for the management of patients with intermediate LAD stenosis. 相似文献
976.
Magali J. Rochat Fausto Caruana Ahmad Jezzini Ludovic Escola Irakli Intskirveli Franck Grammont Vittorio Gallese Giacomo Rizzolatti Maria Alessandra Umiltà 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2010,204(4):605-616
Mirror neurons are a distinct class of neurons that discharge both during the execution of a motor act and during observation
of the same or similar motor act performed by another individual. However, the extent to which mirror neurons coding a motor
act with a specific goal (e.g., grasping) might also respond to the observation of a motor act having the same goal, but achieved
with artificial effectors, is not yet established. In the present study, we addressed this issue by recording mirror neurons
from the ventral premotor cortex (area F5) of two monkeys trained to grasp objects with pliers. Neuron activity was recorded
during the observation and execution of grasping performed with the hand, with pliers and during observation of an experimenter
spearing food with a stick. The results showed that virtually all neurons responding to the observation of hand grasping also responded
to the observation of grasping with pliers and, many of them to the observation of spearing with a stick. However, the intensity
and pattern of the response differed among conditions. Hand grasping observation determined the earliest and the strongest
discharge, while pliers grasping and spearing observation triggered weaker responses at longer latencies. We conclude that
F5 grasping mirror neurons respond to the observation of a family of stimuli leading to the same goal. However, the response pattern depends upon the similarity between the observed motor
act and the one executed by the hand, the natural motor template. 相似文献
977.
The authors present a simple technique for restoration of the umbilicus in abdominal dermolipectomy. This procedure is represented
by a double-Y cutaneous incision on the abdominal skin and by a double-M cutaneous incision on the umbilical skin. This technique
restores a neoumbilicus with multiple small skin flaps and conceals the periumbilical scar at the bottom of the umbilicus.
Different designs and figures are proposed to explain the procedure. 相似文献
978.
Detecting myocardial salvage after primary PTCA: early myocardial contrast echocardiography versus delayed sestamibi perfusion imaging. 总被引:5,自引:0,他引:5
R Sciagrà L Bolognese D Rovai S Sestini G M Santoro G Cerisano C Marini P Buonamici D Antoniucci P F Fazzini 《Journal of nuclear medicine》1999,40(3):363-370
The extent of myocardial salvage after primary percutaneous transluminal coronary angioplasty (PTCA) in acute myocardial infarction (AMI) is variable and cannot be predicted on the basis of either vessel patency or early regional wall motion assessment. The aim of this study was to evaluate the reliability of microvascular integrity, as shown by myocardial contrast echocardiography (MCE), as an indicator of tissue salvage and a predictor of late functional recovery, and to compare MCE with the quantification of tracer activity in sestamibi perfusion imaging. METHODS: Twenty-six patients with AMI who received successful treatment with primary PTCA were examined with MCE during cardiac catheterization immediately before and after vessel recanalization. Myocardial contrast effect was scored as 0 (absent), 0.5 (partial) or 1 (normal). Wall motion was assessed by two-dimensional echocardiography on admission and 1 mo later with a 16-segment model and 4-point score. Resting sestamibi SPECT was collected within 1 wk after AMI. The risk area was defined by MCE as the sum of the segments with no perfusion (score 0) before PTCA. Myocardial viability was defined by MCE as an increase in contrast score in the same segments after PTCA and by sestamibi SPECT as a preserved tracer activity (>60% of peak activity). The functional recovery after 1 mo detected by two-dimensional echocardiography was the reference standard for viability. RESULTS: A total of 50 segments showed perfusion defects before PTCA (risk area). Immediately after PTCA, the MCE score increased in 44 of 50 segments, whereas sestamibi SPECT showed preserved activity in 22 of 50 segments. After 1 mo, the wall motion score decreased in 22 of 50 segments (viable segments) and was unchanged in the remaining 28 segments. Thus, MCE showed a sensitivity of 91% and a specificity of 14% in detecting viable myocardium, whereas sestamibi SPECT showed a lower sensitivity (68%) but a significantly higher specificity (75%; P < 0.00001). The positive predictive values were 45% and 68% for MCE and SPECT (P < 0.005), respectively, and the negative predictive values were 67% and 71%, respectively. On a patient basis, SPECT was more specific (79% versus 21%; P < 0.01) and showed a higher overall predictive accuracy (88% versus 50%; P < 0.01) than MCE. CONCLUSION: The demonstration of microvascular integrity by MCE performed immediately after primary PTCA has a limited diagnostic value in predicting salvaged myocardium. Conversely, tracer activity quantification in resting sestamibi SPECT performed in a later stage is confirmed to be a reliable approach for recognizing myocardial stunning and predicting functional recovery. 相似文献
979.
980.
Delia Reina Dacia Cerdà Daniel Roig Ramon Fíguls M. Luz Villegas Hèctor Corominas 《Reumatología clinica》2013,9(4):246-247
Sweet's syndrome or acute neutrophilic febrile dermatosis is a systemic disease of unknown etiology characterized by the appearance of skin lesions produced by a neutrophilic dermal infiltrate, fever and peripheral leukocytosis. It may be associated with hematologic diseases, including leukemia, with immune diseases as rheumatoid arthritis, or can occur in isolation. The myelodysplasias are hematological disorders characterized by one or more cytopenias secondary to bone marrow dysfunction. We present the case of a patient with Sweet's syndrome associated with myelodysplastic syndrome and treated with glucocorticoids who did not present a good clinical outcome. We discuss the different treatment of these diseases because in most cases glucocorticoids, which are the treatment of choice in Sweet's syndrome, may be insufficient. 相似文献