全文获取类型
收费全文 | 19735篇 |
免费 | 1347篇 |
国内免费 | 82篇 |
专业分类
耳鼻咽喉 | 161篇 |
儿科学 | 372篇 |
妇产科学 | 550篇 |
基础医学 | 2346篇 |
口腔科学 | 564篇 |
临床医学 | 1747篇 |
内科学 | 5714篇 |
皮肤病学 | 511篇 |
神经病学 | 1902篇 |
特种医学 | 520篇 |
外科学 | 2763篇 |
综合类 | 163篇 |
一般理论 | 6篇 |
预防医学 | 1433篇 |
眼科学 | 255篇 |
药学 | 1075篇 |
中国医学 | 71篇 |
肿瘤学 | 1011篇 |
出版年
2023年 | 161篇 |
2022年 | 386篇 |
2021年 | 678篇 |
2020年 | 358篇 |
2019年 | 588篇 |
2018年 | 757篇 |
2017年 | 454篇 |
2016年 | 476篇 |
2015年 | 546篇 |
2014年 | 809篇 |
2013年 | 950篇 |
2012年 | 1510篇 |
2011年 | 1513篇 |
2010年 | 787篇 |
2009年 | 715篇 |
2008年 | 1218篇 |
2007年 | 1184篇 |
2006年 | 1147篇 |
2005年 | 1122篇 |
2004年 | 951篇 |
2003年 | 809篇 |
2002年 | 797篇 |
2001年 | 255篇 |
2000年 | 253篇 |
1999年 | 220篇 |
1998年 | 136篇 |
1997年 | 115篇 |
1996年 | 134篇 |
1995年 | 93篇 |
1994年 | 95篇 |
1993年 | 65篇 |
1992年 | 136篇 |
1991年 | 137篇 |
1990年 | 137篇 |
1989年 | 99篇 |
1988年 | 95篇 |
1987年 | 109篇 |
1986年 | 93篇 |
1985年 | 102篇 |
1984年 | 77篇 |
1983年 | 63篇 |
1982年 | 66篇 |
1981年 | 49篇 |
1980年 | 49篇 |
1979年 | 49篇 |
1974年 | 52篇 |
1973年 | 49篇 |
1972年 | 48篇 |
1971年 | 46篇 |
1969年 | 45篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Nuckols JD Baron PW Stenzel TT Olatidoye BA Tuttle-Newhall JE Clavien PA Howell DN 《The American journal of surgical pathology》2000,24(5):733-741
Post-transplantation lymphoproliferative disease (PTLD) is a complication of solid organ transplantation that is typically of B-cell origin and associated with Epstein-Barr virus (EBV). In patients receiving orthotopic liver transplantation (OLT) and treated with cyclosporin A. PTLD typically presents between 6 and 17 months post-transplantation as a systemic illness with involvement of the hepatic graft in a minority of cases. A small number of cases of biopsy-proven PTLD arising in the hepatic graft and limited to the liver and periportal structures have been previously reported. This report describes three additional cases of liver-localized PTLD and reviews similar cases in the literature. The donor/host origin of PTLD may have prognostic significance because the two cases in this report that are of donor origin had different clinical and pathologic features compared with the case of host origin. A rapid PCR-based technique for determining the origin of PTLD is described. 相似文献
92.
93.
Pedro Cabral 《European journal of paediatric neurology》2006,10(2):66-77
Attention deficit disorder (AAD) and attention deficit/hyperactivity disorder (ADHD) are very frequent and protean developmental disorders without a definite biologic marker. This review proposes a framework to understand the enlarged spectrum of its manifestations based on current knowledge of the mechanisms underlying arousal and attention variations during sleep/wake cycle. The neuro-modulation's pivotal role in this process as well as in the fine tuning of synaptic architecture during development must be taken into account when trying to understand the marked fuzziness of the symptoms and the very high prevalence of reported co-morbidities. The series of related interactions includes a cyclic deactivation of the dorso-lateral portion of the prefrontal cortex (DLPFC) during sleep, suspending executive functions, co-occurring with rhythmic periods of decreased noradrenergic tonus. A protracted unbalance in modulation, with catecholaminergic relative deficiency, could explain less-than-optimum waking DLPFC activation and the most important manifestations of ADD. Beside the well documented dopaminergic effects of stimulant medication used in ADD and ADHD, a more important role must be assigned to noradrenaline (NA). At this light hyperactivity and impulsivity are less important dimensions. Rather, an attention deficit spectrum disorder should probably be regarded as a complication of a core defect in prefrontal cortex dependent inhibitory control, underlying inattention. 相似文献
94.
Treatment of childhood-onset schizophrenia with olanzapine 总被引:4,自引:0,他引:4
This paper reports on a clinical observation of 15 hospitalized youths ages 6-13 years diagnosed with childhood-onset schizophrenia and acutely treated with olanzapine. Initial sedation was the most common side effect observed. Youngsters who had not had a previous trial on any psychotropic did better than those that had failed a previous medication trial. Age was inversely correlated with positive response to olanzapine. Patients who experienced initial sedation did best once the initial sedation wore off. The majority of patients in the study improved on olanzapine. 相似文献
95.
Lamy ML Daily EK Brichant JF Larbuisson RP Demeyere RH Vandermeersch EA Lehot JJ Parsloe MR Berridge JC Sinclair CJ Baron JF Przybelski RJ 《Anesthesiology》2000,92(3):646-656
BACKGROUND: Risks associated with transfusion of allogeneic blood have prompted development of methods to avoid or reduce blood transfusions. New oxygen-carrying compounds such as diaspirin cross-linked hemoglobin (DCLHb) could enable more patients to avoid allogeneic blood transfusion. METHODS: The efficacy, safety, hemodynamic effects, and plasma persistence of DCLHb were investigated in a randomized, active-control, single-blind, multicenter study in post-cardiac bypass surgery patients. Of 1,956 screened patients, 209 were determined to require a blood transfusion and met the inclusion criteria during the 24-h post-cardiac bypass period. These patients were randomized to receive up to three 250-ml infusions of DCLHb (n = 104) or three units of packed erythrocytes (pRBCs; n = 105). Further transfusions of pRBCs or whole blood were permitted, if indicated. Primary efficacy end points were the avoidance of blood transfusion through hospital discharge or 7 days postsurgery, whichever came first, and a reduction in the number of units of pRBCs transfused during this same time period. Various laboratory, physiologic, and hemodynamic parameters were monitored to define the safety and pharmacologic effect of DCLHb in this patient population. RESULTS: During the period from the end of cardiopulmonary bypass surgery through postoperative day 7 or hospital discharge, 20 of 104 (19%) DCLHb recipients did not receive a transfusion of pRBCs compared with 100% of control patients (P < 0.05). The overall number of pRBCs administered during the 7-day postoperative period was not significantly different. Mortality was similar between the DCLHb (6 of 104 patients) and the control (8 of 105 patients) groups. Hypertension, jaundice/hyperbilirubinemia, increased serum glutamic oxalo-acetic transaminase, abnormal urine, and hematuria were reported more frequently in the DCLHb group, and there was one case of renal failure in each group. The hemodynamic effects of DCLHb included a consistent and slightly greater increase in systemic and pulmonary vascular resistance with associated increases in systemic and pulmonary arterial pressures compared with pRBC. Cardiac output values decreased more in the DCLHb group patients after the first administration than the control group patients. At 24 h postinfusion, the plasma hemoglobin level was less than one half the maximal level for any amount of DCLHb infused. CONCLUSIONS: Administration of DCLHb allowed a significant number (19%) of cardiac surgery patients to avoid exposure to erythrocytes postoperatively. 相似文献
96.
Tyvin Rich Pasquale F Innominato Julie Boerner M Christine Mormont Stefano Iacobelli Benoit Baron Claude Jasmin Francis Lévi 《Clinical cancer research》2005,11(5):1757-1764
PURPOSE: Incapacitating symptom burden in cancer patients contributes to poor quality of life (QOL) and can influence treatment outcomes because of poor tolerance to therapy. In this study, the role of circulating cytokines in the production symptoms in cancer patients is evaluated. EXPERIMENTAL DESIGN: Eighty patients with metastatic colorectal cancer with either normal (group I, n = 40) or dampened (group II, n = 40) 24-hour rest/activity patterns measured by actigraphy were identified. Actigraphy patterns were correlated with QOL indices, serum cortisol obtained at 8:00 a.m. and 4:00 p.m. and with serum levels of transforming growth factor-alpha, tumor necrosis factor-alpha, and interleukin 6 (IL-6) obtained at 8:00 a.m. and analyzed in duplicate by ELISA. Cytokine levels and survival were also correlated. RESULTS: Group II patients had significantly higher pre treatment levels of all three cytokines, displayed significantly poorer emotional and social functioning, had higher fatigue, more appetite loss, and poorer performance status compared with group I patients. Transforming growth factor-alpha (TGF-alpha) and IL-6 were significantly increased in the patients with WHO performance status >1 and in those with appetite loss. Fatigue was significantly associated with elevated TGF-alpha only. IL-6 was increased in those patients with extensive liver involvement and multiple organ replacement, and it was significantly correlated with dampened cortisol rhythm. In a multivariate analysis, IL-6 was correlated with poor treatment outcome. CONCLUSIONS: Significant correlations were found between serum levels of TGF-alpha and IL-6, circadian patterns in wrist activity and serum cortisol and tumor-related symptoms in patients with metastatic colorectal cancer. These data support the hypothesis that some cancer patient's symptoms of fatigue, poor QOL, and treatment outcome are related to tumor or host generated cytokines and could reflect cytokine effects on the circadian timing system. This interplay between cytokine signaling pathways, the hypothalamic-pituitary-adrenal axis, the autonomic nervous system, and efferent pathways of the suprachiasmatic nucleus that control circadian physiology, opens the way to new rational interventions for symptom management in cancer patients. 相似文献
97.
Reported use of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors was not associated with reduced recurrence of colorectal adenomas. 总被引:2,自引:0,他引:2
Jeffrey T Wei Leila A Mott John A Baron Robert S Sandler 《Cancer epidemiology, biomarkers & prevention》2005,14(4):1026-1027
We did a secondary analysis of data from three large colorectal adenoma chemoprevention trials to assess the association between 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor use and reduced risk of recurrent colorectal adenomas. Reported use of HMG-CoA reductase inhibitors was not associated with a reduced recurrence of colorectal adenomas, multiple adenomas, or advanced adenomas. Lack of statistical power from limited exposure to HMG-CoA reductase inhibitors might be responsible for the lack of association. 相似文献
98.
Isabel Monteiro-Grillo Pedro Marques-Vidal Marília Jorge 《Clinical & translational oncology》2005,7(11):499-503
Purpose To compare the quality-of-life (QoL) and psycho-social changes in a group of patients with early breast cancer who underwent
conservative surgery (BCS) or modified radical mastectomy (MRM).
Methods Self-administered questionnaire assessing body image perception, social habits, sexual attraction and self-consciousness with
relatives/friends, was randomly assigned to 125 patients (61 BCS, 64 MRM; aged 53±8 and 50±9 years, respectively, p=NS).
Results MRM patients reported a significantly higher frequency of changes in body image perception and other related social behaviour
such as avoiding going to the beach or using low-cut clothes, and reticence with friends. Conversely, no differences were
found regarding sexuality, denial of the disease by the husband/partner, or concealing the disease from family members. Also,
no significant differences were found between patients above and below the age of 50 years, for all variables studied after
adjustment for surgical procedure.
Conclusions Modified radical mastectomy has a negative effect on body image perception and in social behaviour patterns of patients and
with a concomitant decrease in QoL. The sexuality of the patient is not significantly affected. 相似文献
99.
Filipa Alves da Costa Jos Pedro Guerreiro Magda Nunes de Melo Ana da Costa Miranda Ana Paula Martins Jos Garo Brenda Madureira 《The International journal of pharmacy practice》2005,13(3):205-211
Objective Poor compliance to antihypertensive medications has been identified as a primary cause of uncontrolled blood pressure (BP), with consequent increases in hypertension‐related morbidity and mortality. Therefore, any measure known to improve compliance should be encouraged. This study assessed the impact of reminder cards on compliance to antihypertensive therapy. Method A field trial was undertaken in pharmacies located in the districts of Lisbon and Porto. Eligible participants comprised those aged 30–74 years, prescribed an angiotensin‐converting enzyme inhibitor (ACEI) in monotherapy, and taken on a once‐daily regimen. Patients were allocated to control group (CG) or intervention group (IG), the latter being provided with a reminder card, an alarm‐type device due to remind the patient of the time to take his medication. Patients were monitored monthly during 3 months for compliance and blood pressure control. Key findings Seventy‐one patients participated in the study (intervention: 35; control group: 36). Compliance was similar between the groups in the first 2 months of follow‐up (97.1% IG vs 94.9% CG at first follow‐up and 97.5% IG vs 94.2% CG at second follow‐up) and higher in the intervention group at the end of the study (97.3% IG vs 87.3% CG; P = 0.011). There were no mean blood pressure differences between compliant and non‐compliant subjects at the end of the study (P value for differences in systolic BP (Psyst) = 0.580; and P value for differences in diastolic BP (Pdlast) = 0.175). Conclusion This small‐scale study indicates a possible positive impact on patients' compliance resulting from the use of reminder cards. However, this needs confirming in larger scale studies with longer monitoring periods. 相似文献
100.
Interaction between insulin sensitivity and muscle perfusion on glucose uptake in human skeletal muscle: evidence for capillary recruitment 总被引:8,自引:0,他引:8
Baron AD Tarshoby M Hook G Lazaridis EN Cronin J Johnson A Steinberg HO 《Diabetes》2000,49(5):768-774
Insulin and glucose delivery (muscle perfusion) can modulate insulin-mediated glucose uptake. This study was undertaken to determine 1) to what extent insulin sensitivity modulates the effect of perfusion on glucose uptake and 2) whether this effect is achieved via capillary recruitment. We measured glucose disposal rates (GDRs) and leg muscle glucose uptake (LGU) in subjects exhibiting a wide range of insulin sensitivity, after 4 h of steady-state (SS) euglycemic hyperinsulinemia (>6,000 pmol/l) and subsequently after raising the rate of leg blood flow (LBF) 2-fold with a superimposed intrafemoral artery infusion of methacholine chloride (Mch), an endothelium-dependent vasodilator. LBF was determined by thermodilution: LGU = arteriovenous glucose difference (AVGdelta) x LBF. As a result of the 114+/-12% increase in LBF induced by Mch, the AVGdelta decreased 32+/-4%, and overall rates of LGU increased 40+/-5% (P < 0.05). We found a positive relationship between the Mch-modulated increase in LGU and insulin sensitivity (GDR) (r = 0.60, P < 0.02), suggesting that the most insulin-sensitive subjects had the greatest enhancement of LGU in response to augmentation of muscle perfusion. In separate groups of subjects, we also examined the relationship between muscle perfusion rate and glucose extraction (AVGdelta). Perfusion was either pharmacologically enhanced with Mch or reduced by intra-arterial infusion of the nitric oxide inhibitor N(G)-monomethyl-L-arginine during SS euglycemic hyperinsulinemia. Over the range of LBF, changes in AVGdelta were smaller than expected based on the noncapillary recruitment model of Renkin. Together, the data indicate that 1) muscle perfusion becomes more rate limiting to glucose uptake as insulin sensitivity increases and 2) insulin-mediated increments in muscle perfusion are accompanied by capillary recruitment. Thus, insulin-stimulated glucose uptake displays both permeability- and perfusion-limited glucose exchange properties. 相似文献