全文获取类型
收费全文 | 4703篇 |
免费 | 318篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 19篇 |
儿科学 | 148篇 |
妇产科学 | 109篇 |
基础医学 | 717篇 |
口腔科学 | 128篇 |
临床医学 | 366篇 |
内科学 | 1126篇 |
皮肤病学 | 216篇 |
神经病学 | 537篇 |
特种医学 | 44篇 |
外科学 | 322篇 |
综合类 | 21篇 |
预防医学 | 406篇 |
眼科学 | 145篇 |
药学 | 373篇 |
中国医学 | 34篇 |
肿瘤学 | 330篇 |
出版年
2024年 | 3篇 |
2023年 | 38篇 |
2022年 | 89篇 |
2021年 | 170篇 |
2020年 | 101篇 |
2019年 | 163篇 |
2018年 | 178篇 |
2017年 | 127篇 |
2016年 | 147篇 |
2015年 | 156篇 |
2014年 | 216篇 |
2013年 | 253篇 |
2012年 | 437篇 |
2011年 | 422篇 |
2010年 | 238篇 |
2009年 | 187篇 |
2008年 | 341篇 |
2007年 | 288篇 |
2006年 | 271篇 |
2005年 | 285篇 |
2004年 | 255篇 |
2003年 | 221篇 |
2002年 | 231篇 |
2001年 | 13篇 |
2000年 | 11篇 |
1999年 | 30篇 |
1998年 | 29篇 |
1997年 | 24篇 |
1996年 | 21篇 |
1995年 | 13篇 |
1994年 | 8篇 |
1993年 | 12篇 |
1992年 | 9篇 |
1991年 | 7篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 6篇 |
1986年 | 6篇 |
1983年 | 2篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 2篇 |
1978年 | 3篇 |
1976年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有5041条查询结果,搜索用时 15 毫秒
21.
Aurigena Antunes de Araújo Susana Barbosa Ribeiro Ana Cely Souza dos Santos Telma Maria Araújo Moura Lemos Caroline Addison Xavier Medeiros Gerlane Coelho Bernardo Guerra Raimundo Fernandes de Araújo Júnior Antoni Serrano-Blanco Maria Rubio-Valera 《The Psychiatric quarterly》2016,87(2):293-304
This cross-sectional study compared quality of life and side effects in 108 users of olanzapine or risperidone suffering schizophrenia and being attended at psychiatric ambulatory services in Rio Grande do Norte, Brazil. Economic, socio-demographic, anthropometric, biochemical, and hormonal variables were compared. The EuroQoL Five-Dimension Scale (EQ-5D) was used to evaluate quality of life, and side effects were assessed using the Udvalg for Kliniske Undersøgelser (UKU) Side Effect Rating Scale and the Simpson–Angus Scale. Data were analysed using the χ2 test and Student’s t test, with a significance level of 5 %.The household incomes of approximately 80 % of patients were <2.0 minimum wages ($678). Anthropometric variables (waist circumference, hip circumference, weight, waist-to-hip ratio) and systolic and diastolic blood pressure were noted among male olanzapine users (all p < 0.05). EQ-5D scores showed that olanzapine use significantly impacted self-help ability (p < 0.001). Risperidone users had a mean quality-adjusted life year value of 1. Mean total Simpson–Angus Scale scores was 0.38 for olanzapine users and 0.11 for risperidone users (p < 0.02). Significant differences in UKU were observed for the following items: asthenia/lassitude/fatigue (higher among olanzapine users, p = 0.02), dystonia (higher among olanzapine users, p = 0.01), tremors (higher among olanzapine users, p = 0.03), gynecomastia (higher among risperidone users, p < 0.02), and ejaculatory dysfunction (higher among risperidone users, p < 0.02). Olanzapine users had impaired quality of life, which can be explained in part by adverse motor, biochemical, and hormonal effects characteristic of metabolic syndrome. 相似文献
22.
Thakar CV Arrigain S Worley S Yared JP Paganini EP 《Journal of the American Society of Nephrology : JASN》2005,16(1):162-168
The risk of mortality associated with acute renal failure (ARF) after open-heart surgery continues to be distressingly high. Accurate prediction of ARF provides an opportunity to develop strategies for early diagnosis and treatment. The aim of this study was to develop a clinical score to predict postoperative ARF by incorporating the effect of all of its major risk factors. A total of 33,217 patients underwent open-heart surgery at the Cleveland Clinic Foundation (1993 to 2002). The primary outcome was ARF that required dialysis. The scoring model was developed in a randomly selected test set (n = 15,838) and was validated on the remaining patients. Its predictive accuracy was compared by area under the receiver operating characteristic curve. The score ranges between 0 and 17 points. The ARF frequency at each score level in the validation set fell within the 95% confidence intervals (CI) of the corresponding frequency in the test set. Four risk categories of increasing severity (scores 0 to 2, 3 to 5, 6 to 8, and 9 to 13) were formed arbitrarily. The frequency of ARF across these categories in the test set ranged between 0.5 and 22.1%. The score was also valid in predicting ARF across all risk categories. The area under the receiver operating characteristic curve for the score in the test set was 0.81 (95% CI 0.78 to 0.83) and was similar to that in the validation set (0.82; 95% CI 0.80 to 0.85; P = 0.39). In conclusion, a score is valid and accurate in predicting ARF after open-heart surgery; along with increasing its clinical utility, the score can help in planning future clinical trials of ARF. 相似文献
23.
24.
Nephropathy associated with heroin abuse in Caucasian patients. 总被引:1,自引:0,他引:1
Maria do Sameiro Faria Susana Sampaio Victor Faria Elísio Carvalho 《Nephrology, dialysis, transplantation》2003,18(11):2308-2313
BACKGROUND: Renal disease is a complication of heroin addiction. Using renal biopsies in Caucasian patients, we studied the types of nephropathy associated with heroin abuse. METHODS: Nineteen renal biopsies were performed on heroin addicts between January 1993 and December 2001. The indications for renal biopsy included proteinuria with or without renal insufficiency. RESULTS: All 19 patients had serological evidence of hepatitis C virus (HCV) infection, one had hepatitis B virus surface antigen and three were HIV positive. Thirteen patients (68.4%) were found to have membranoproliferative glomerulonephritis (MPGN), 12 with type I and one with type III. Of the remaining patients, two had chronic interstitial nephritis, two had acute proliferative glomerulonephritis, one had amyloidosis and one had granulomatous glomerulonephritis with interstitial nephritis. No apparent decline in the incidence of renal disease was observed. CONCLUSIONS: In this cohort of male Caucasian heroin addicts, HCV-associated MPGN was the most frequent pattern of nephropathy, showing that the nephropathy associated with heroin abuse in Caucasians is not of the focal and segmental glomerulosclerosis type, in contrast to previous reports on African-Americans. This aspect may have important implications for patient management and prognosis. 相似文献
25.
Background We describe a new method to study the sensibility of the nipple-areola complex of the breast with faradic electricity delivered
through an electromyographic device used to monitor peripheral nerve conduction.
Methods The objective results of faradic pulses (2–50 mA per pulse) delivered to the nipple-areola complex of the breast through a
Nihon-Kohden II machine (Evoked potential/Electromyographs, Nihon-Kohden Co., Japan) were evaluated in normal volunteers to
get a basal measure that was defined by the patient as “a soft electric discharge.” The measures were recorded and their output
discharges averaged (at least 5 to each complex).
Results Twenty-eight volunteers with normal breasts, 28 patients with breast hypertrophy before and after breast reduction, and 28
patients before and after breast augmentation were studied. The faradic pulses were perceived from 1.5 to 3.5 mA in the areola
and from 3 to 5.5 mA in the nipple in the control group and from 4.5 to 7.0 mA in the areola and from 6.5 to 9.5 mA in the
nipple in the breast hypertrophy group with no significant changes before and after surgery. In the breast augmentation group
the faradic pulses were very similar to the volunteers that had normal breasts, but 13 months after breast augmentation with
silicone gel prosthesis, a difference was found because all the patients had a higher threshold and three cases had lost sensibility
of the nipple-areola complex.
Conclusion In normal breasts the areola had a lower threshold for faradic pulses compared to the nipple. Hypertrophic breasts had a higher
threshold to the faradic stimulation than normal subjects in the pre- and postoperative period. Hypoplastic breasts before
breast augmentation had a perception threshold similar to that of the normal volunteers but after breast augmentation this
perception was much higher.
This study received the Scientific Exhibit Award at the ASAPS/ASERF Annual Meeting in Vancouver, British Columbia, Canada,
2005. 相似文献
26.
Labombarda F Gonzalez SL Gonzalez DM Guennoun R Schumacher M de Nicola AF 《Journal of neurotrauma》2002,19(3):343-355
Progesterone (PROG) exerts beneficial and neuroprotective effects in the injured central and peripheral nervous system. In the present work, we examine PROG effects on three measures of neuronal function under negative regulation (choline acetyltransferase [ChAT] and Na,K-ATPase) or stimulated (growth-associated protein [GAP-43]) after acute spinal cord transection injury in rats. As expected, spinal cord injury reduced ChAT immunostaining intensity of ventral horn neurons. A 3-day course of intensive PROG treatment of transected rats restored ChAT immunoreactivity, as assessed by frequency histograms that recorded shifts from predominantly light neuronal staining to medium, dark or intense staining typical of control rats. Transection also reduced the expression of the mRNA for the alpha3 catalytic and beta1 regulatory subunits of neuronal Na,K-ATPase, whereas PROG treatment restored both subunit mRNA to normal levels. Additionally, the upregulation observed for GAP-43 mRNA in ventral horn neurons in spinal cord-transected rats, was further enhanced by PROG administration. In no case did PROG modify ChAT immunoreactivity, Na,K-ATPase subunit mRNA or GAP-43 mRNA in control, sham-operated rats. Further, the PROG-mediated effects on these three markers were observed in large, presumably Lamina IX motoneurons, as well as in smaller neurons measuring approximately <500 micro2. Overall, the stimulatory effects of PROG on ChAT appears to replenish acetylcholine, with its stimulatory effects on Na,K-ATPase seems capable of restoring membrane potential, ion transport and nutrient uptake. PROG effects on GAP-43 also appear to accelerate reparative responses to injury. As the cellular basis for PROG neuroprotection becomes better understood it may prove of therapeutic benefit to spinal cord injury patients. 相似文献
27.
María de Oña Navarro Santiago Melón Susana Méndez Beatriz Iglesias Ana Palacio María J. Bernardo José L. Rodriguez-Lambert Ernesto Gómez 《Transplant international》2002,15(11):570-573
Ganciclovir (GCV) prophylaxis or pre-emptive therapy significantly reduce the rate of cytomegalovirus (CMV) disease and viremia, but increase the potential for emergence of ganciclovir-resistant CMV strains. The inhibitor concentration at 50% (IC(50)) of GCV from 156 CMV isolates from 59 renal or heart transplant recipients was calculated by means of a rapid phenotypic susceptibility assay. Twenty-seven strains were from 14 patients undergoing GCV therapy. The IC(50) was higher in patients under the prophylaxis regimen. One CMV strain, from a heart transplant recipient, became GCV-resistant after 1 month of therapy (IC(50)=13.7 micromol/l). These data, together with clinical and virological markers, suggested that a switch to foscarnet was necessary, and good evolution was observed. Thus, assay of CMV susceptibility to GCV could be helpful in clinical management. 相似文献
28.
Mechanism of vascular smooth muscle cells activation by hydrogen peroxide: role of phospholipase C gamma. 总被引:2,自引:0,他引:2
Francisco R González-Pacheco Carlos Caramelo Maria Angeles Castilla Juan J P Deudero Javier Arias Susana Yagüe Sonsoles Jiménez Rafael Bragado Maria Victoria Alvarez-Arroyo 《Nephrology, dialysis, transplantation》2002,17(3):392-398
BACKGROUND: Hydrogen peroxide (H2O2) formation is a critical factor in processes involving ischaemia/ reperfusion. However, the precise mechanism by which reactive oxygen species (ROS) induce vascular damage are insufficiently known. Specifically, activation of phospholipase C gamma (PLCgamma) is a probable candidate pathway involved in vascular smooth muscle cells (VSMC) activation by H2O2. METHODS: The activation of human venous VSMC was measured as cytosolic free calcium mobilization, shape change and protein phosphorylation, focusing on the role of tyrosine phosphorylation-activated PLCgamma. RESULTS: The exposure of VSMC to exogenous H2O2 caused a rapid increase in cytosolic free calcium concentration ([Ca2+]i), and induced a significant VSMC shape change. Both effects were dependent on a tyrosine kinase-mediated mechanism, as determined by the blockade of short-term treatment of VSMC with the protein tyrosine kinase inhibitor, genistein. Giving further support to the putative role of phospholipase C (PLC)-dependent pathways, the [Ca2+]i and VSMC shape change response were equally inhibited by the specific PLC blocker, 1-(6-((17-beta-methoxyestra-1,3,5(10)trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione (U73122). In addition, U73122 had a protective effect against the deleterious action (24 h) of H2O2 on non-confluent VSMC. As a further clarification of the specific pathway involved, the exposure to H2O2 significantly stimulated the tyrosine phosphorylation of PLCgamma with a concentration- and time-profile similar to that of [Ca(2+)](i) mobilization. CONCLUSIONS: The present study reveals that H(2)O(2) activates PLCgamma on VSMC through tyrosine phosphorylation and that this activation has a major role in rapid [Ca(2+)](i) mobilization, shape-changing actions and damage by H(2)O(2) in this type of cells. These findings have direct implications for understanding the mechanisms of the vascular actions of H(2)O(2) and may help to design pharmacologically protective strategies. 相似文献
29.
Plasma levels and vascular effects of vasopressin in patients undergoing coronary artery bypass grafting. 总被引:1,自引:0,他引:1
Susana Novella Ana Cristina Martínez Rosa María Pagán Medardo Hernández Albino García-Sacristán Angel González-Pinto José María González-Santos Sara Benedito 《European journal of cardio-thoracic surgery》2007,32(1):69-76
OBJECTIVE: Recent studies have suggested that endogenous vasopressin (AVP) acts as a spasmogen during coronary artery bypass grafting (CABG). Given that AVP could induce vasospasm in the grafted vessel, we assessed the release of this peptide during and after CABG, and explored ways of counteracting its contractile effect on the internal mammary artery (IMA). METHODS: Plasma levels of AVP were determined by radioimmunoassay in 16 patients before, during and after CABG. Using isometric force recording techniques, we also investigated the mechanisms involved in the contractile effect of AVP in ring preparations of IMA specimens taken from 95 patients. RESULTS: Plasma AVP levels peaked after the start of cardiopulmonary bypass (CPB) and correlated well with serum osmolality (Pearson's r=0.9490; P<0.0001; n=16). An inverse correlation was observed between plasma AVP levels recorded at this stage and the maximal contraction induced in vitro by AVP in vascular rings from the same patients (Pearson's r=-0.6968; P<0.01; n=16). No change in the AVP response was produced by endothelium removal, exposure to the NO precursor (3 x 10(-4)M L-arginine), inhibition of nitric oxide (NO) synthase (3 x 10(-5) M L-NAME) or soluble guanylate cyclase (3 x 10(-6) M 1H-[1,2,4]oxadiazol [4,3,-alpha]quinoxalin-1-one (ODQ)), removal of the superoxide anion (100 U/ml superoxide dismutase (SOD) plus 1200 U/ml catalase) or hydroxyl radical (10(-4) M deferoxamine), or specific alpha1 - (10(-6) M prazosin) or endothelin (10(-5) M bosentan) receptor antagonism. In contrast, adenylate cyclase activation (3 x 10(-8) M forskolin) reduced the contractile response to AVP, while prostanoid synthesis (3 x 10(-6) M indomethacin) inhibition and blockade of Ca2+ -activated potassium channels (KCa) (10(-3) M tetraethylammonium (TEA)) enhanced AVP contraction. Age, gender and smoking also modified the AVP response. CONCLUSION: Our findings suggest a role for AVP as a modulator of vascular tone in human IMA. The effect of AVP is dependent on prostanoids and Ca2+ -activated K+ channels, so its dysfunction in pathophysiological cardiovascular processes could mean that AVP, among other factors, produces vasospasm in IMA grafts. 相似文献
30.
Penna G Mondaini N Amuchastegui S Degli Innocenti S Carini M Giubilei G Fibbi B Colli E Maggi M Adorini L 《European urology》2007,51(2):524-33; discussion 533
OBJECTIVE: This prospective study quantified cytokine and chemokine levels in seminal plasma of patients with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) and benign prostatic hyperplasia (BPH), to evaluate inflammatory mediators as possible surrogate markers for diagnosis and treatment efficacy. METHODS: Seminal plasma levels of eight cytokines and nine chemokines were evaluated by multiplex arrays in 83 men: 20 healthy controls and 9 men with CP/CPPS IIIA, 31 with CP/CPPS IIIB, and 23 with BPH. Prostate samples obtained by transurethral resection of the prostate from 13 patients with BPH were analysed by immunohistochemistry to detect interleukin 8 (IL-8)-producing cells and characterise inflammatory infiltrates. RESULTS: Significantly increased levels of cytokines (IL-1alpha, IL-1beta, IL-6, IL-10, IL12p70) and chemokines (CCL1, CCL3, CCL4, CCL17, CCL22, CXCL8/IL-8) were observed in seminal plasmas from patients with CP/CPPS or BPH. However, only IL-8 was significantly elevated compared to controls (median [quartiles] 1984 [1164-2444] pg/ml), in patients with CP/CPPS IIIA (15,240 [10,630-19,501] pg/ml; p<0.0001), CP/CPPS IIIB (2983 [2033-5287] pg/ml; p=0.008), and BPH (5044 [3063-11,795] pg/ml, p<0.0001), discriminating CP/CPPS IIIA versus IIIB (accuracy=0.882+/-0.078; p=0.001). Inflammatory infiltrates were detected in prostate samples from 13 of 13 BPH patients, and IL-8-producing prostate cells in 11 of 13 samples. IL-8 concentration in seminal plasma was positively correlated with symptom score and prostate-specific antigen levels both in CP/CPPS and BPH patients. CONCLUSIONS: IL-8 is expressed in situ by epithelial and stromal prostate cells and is functional, as shown by recruitment of cells expressing cognate receptors in BPH prostate tissue, indicating its involvement in disease pathogenesis. Among all the cytokines and chemokines analysed, IL-8 appears to be the most reliable and predictive surrogate marker to diagnose prostate inflammatory conditions, such as CP/CPPS and BPH. 相似文献