全文获取类型
收费全文 | 3776篇 |
免费 | 193篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 53篇 |
儿科学 | 37篇 |
妇产科学 | 65篇 |
基础医学 | 372篇 |
口腔科学 | 152篇 |
临床医学 | 308篇 |
内科学 | 881篇 |
皮肤病学 | 51篇 |
神经病学 | 403篇 |
特种医学 | 164篇 |
外科学 | 494篇 |
综合类 | 10篇 |
一般理论 | 2篇 |
预防医学 | 183篇 |
眼科学 | 59篇 |
药学 | 287篇 |
中国医学 | 4篇 |
肿瘤学 | 471篇 |
出版年
2023年 | 29篇 |
2022年 | 52篇 |
2021年 | 104篇 |
2020年 | 74篇 |
2019年 | 80篇 |
2018年 | 73篇 |
2017年 | 71篇 |
2016年 | 92篇 |
2015年 | 107篇 |
2014年 | 112篇 |
2013年 | 177篇 |
2012年 | 250篇 |
2011年 | 246篇 |
2010年 | 136篇 |
2009年 | 129篇 |
2008年 | 224篇 |
2007年 | 243篇 |
2006年 | 238篇 |
2005年 | 254篇 |
2004年 | 252篇 |
2003年 | 226篇 |
2002年 | 192篇 |
2001年 | 49篇 |
2000年 | 35篇 |
1999年 | 34篇 |
1998年 | 27篇 |
1997年 | 22篇 |
1996年 | 26篇 |
1995年 | 26篇 |
1994年 | 34篇 |
1993年 | 18篇 |
1992年 | 30篇 |
1991年 | 25篇 |
1990年 | 19篇 |
1989年 | 30篇 |
1988年 | 26篇 |
1987年 | 28篇 |
1986年 | 28篇 |
1985年 | 24篇 |
1984年 | 26篇 |
1983年 | 9篇 |
1982年 | 16篇 |
1981年 | 13篇 |
1980年 | 14篇 |
1979年 | 4篇 |
1978年 | 9篇 |
1976年 | 6篇 |
1975年 | 4篇 |
1974年 | 4篇 |
1971年 | 4篇 |
排序方式: 共有3996条查询结果,搜索用时 15 毫秒
101.
Léonie Egli Virgile Lecoultre Fanny Theytaz Vanessa Campos Leanne Hodson Philippe Schneiter Bettina Mittendorfer Bruce W. Patterson Barbara A. Fielding Philipp A. Gerber Vittorio Giusti Kaspar Berneis Luc Tappy 《Diabetes》2013,62(7):2259-2265
Excess fructose intake causes hypertriglyceridemia and hepatic insulin resistance in sedentary humans. Since exercise improves insulin sensitivity in insulin-resistant patients, we hypothesized that it would also prevent fructose-induced hypertriglyceridemia. This study was therefore designed to evaluate the effects of exercise on circulating lipids in healthy subjects fed a weight-maintenance, high-fructose diet. Eight healthy males were studied on three occasions after 4 days of 1) a diet low in fructose and no exercise (C), 2) a diet with 30% fructose and no exercise (HFr), or 3) a diet with 30% fructose and moderate aerobic exercise (HFrEx). On all three occasions, a 9-h oral [13C]-labeled fructose loading test was performed on the fifth day to measure [13C]palmitate in triglyceride-rich lipoprotein (TRL)-triglycerides (TG). Compared with C, HFr significantly increased fasting glucose, total TG, TRL-TG concentrations, and apolipoprotein (apo)B48 concentrations as well as postfructose glucose, total TG, TRL-TG, and [13C]palmitate in TRL-TG. HFrEx completely normalized fasting and postfructose TG, TRL-TG, and [13C]palmitate concentration in TRL-TG and apoB48 concentrations. In addition, it increased lipid oxidation and plasma nonesterified fatty acid concentrations compared with HFr. These data indicate that exercise prevents the dyslipidemia induced by high fructose intake independently of energy balance.It is currently suspected that overconsumption of fructose, in the form of either sugar or high-fructose corn syrup, may promote obesity and favor the development of metabolic diseases such as type 2 diabetes and dyslipidemia (1,2). This is supported by a large number of studies in rodents, which demonstrate that a high-sucrose diet causes obesity, diabetes, dyslipidemia, and hepatic steatosis (3) and that this effect is mainly due to the fructose component of sucrose (4,5). Consistent with this hypothesis, epidemiological studies have shown that high intakes of sugar, fructose, or sweetened beverages are associated with the development of obesity (6,7), diabetes (8), hypertriglyceridemia (9), an increase in small dense atherogenic LDL particles (10), high blood pressure (11), albuminuria (12), and nonalcoholic fatty liver diseases (13). Several short-term studies have further documented that hypercaloric, high-fructose diets can cause increases in a number of cardiometabolic risk factors in humans, such as fasting and postprandial hypertriglyceridemia (14–18), ectopic lipid deposition in liver cells (19,20), impaired postprandial glucose homeostasis (18), and hepatic insulin resistance (21,22). Some of these effects may be related, at least in part, to the fact that fructose can be converted into fatty acids, which has been demonstrated after both acute (23) and chronic (18) fructose feeding. Exercise is very efficient at reducing the metabolic dysfunctions associated with obesity (24,25), and although many of these effects appear to be related to enhanced energy expenditure and improved energy balance (26,27), there is growing evidence that such improvements are independent of the changes in energy balance or body composition (28,29). Exercise has also been shown to prevent the accumulation of triglyceride-rich lipoprotein (TRL)-triglycerides (TG) and improve the plasma atherogenic lipid profile in healthy subjects fed a high-carbohydrate diet (30). The purpose of this study was to investigate whether exercise would similarly prevent fructose-induced metabolic effects. 相似文献
102.
Gutierrez M Luccioli F Salaffi F Bartoloni E Bertolazzi C Bini V Filipucci E Grassi W Gerli R 《Clinical rheumatology》2012,31(3):463-468
This study was conducted to determine the prevalence of subclinical entheseal involvement at the greater trochanter level
by ultrasound in patients with spondyloarthritis. Forty-six patients with spondyloarthritis and 46 healthy age- and sex-matched
controls were studied. All patients with no clinical evidence of enthesopathy at the greater trochanter underwent an ultrasound
examination. The following three entheses were scanned bilaterally: anterior insertion of gluteus minimus, anterior insertion
of gluteus medius, and posterior insertion of gluteus medius. Ultrasound findings of enthesopathy were thickening, calcifications,
bone erosions, enthesophytes, bursitis, and power Doppler signal. A total of 276 entheses were evaluated in spondyloarthritis
patients. In 112 out of 276 (40.5%), grayscale ultrasound found enthesopathy. The enthesis with the highest number of signs
of enthesopathy was the anterior insertion of gluteus medius (46/276) (16%), followed by posterior insertion of gluteus medius
(37/276) (13.4%) and anterior insertion of gluteus minimus (29/276) (10.5%). In the healthy population, ultrasound found entesopathy
in 80 out of 276 (29%) entheseal sites (p < 0.0001). Posterior insertion of gluteus medius enthesis was the more frequently involved (34/276) (12.3%), followed by
anterior insertion of gluteus medius (24/276) (8.6%) and anterior insertion of gluteus minimus (22/276) (7.9%). Power Doppler
was found more frequently in patients with spondyloarthritis compared with healthy controls (1% vs 0%). Our results show a
higher prevalence of subclinical enthesopathy at the greater trochanter level in patients with spondyloarthritis than in age-
and sex-matched healthy controls. 相似文献
103.
Visalli G Bertuccio MP Currò M Pellicanò G Sturniolo G Carnevali A Spataro P Ientile R Picerno I Cavallari V Piedimonte G 《AIDS research and human retroviruses》2012,28(9):1110-1118
Regressive morphological lesions, found in peripheral lymphocytes from HIV(+) patients, clearly conflict with normal cycle progression and with the execution of basic housekeeping and immune functions. With these lesions, circulating lymphocytes are destined to spontaneous and energy-independent cell lysis. By means of confocal microscopy and morphometry, we have quantified the rate of circulating T cells that are probably destined to emocatheresis in vivo. This rate includes lymphocytes in which nucleolin fragments have been scattered out of the nuclear region as a result of prelethal alterations in the nuclear membrane permeability. In terms of bioenergetics, these cells show evident anomalies in the energy production machinery that make them unable to carry out ATP-requiring functions. The extent of damaged cell fraction in peripheral blood reflects the frequency with which T lymphocytes leave lymphoid tissue to be cleared in hemocatheretic processes. 相似文献
104.
Nkenfou CN Lobé EE Ouwe-Missi-Oukem-Boyer O Sosso MS Dambaya B Gwom LC Moyo ST Tangimpundu C Ambada G Fainguem N Domkam I Nnomzo'o E Ekoa D Milenge P Colizzi V Fouda PJ Cappelli G Torimiro JN Bissek AC 《AIDS research and human retroviruses》2012,28(2):176-181
The testing of dried blood spots (DBSs) for human immunodeficiency type 1 (HIV-1) proviral DNA by PCR is a technology that has proven to be particularly valuable in diagnosing exposed infants. We implemented this technology for HIV-1 early infant diagnosis (EID) and HIV-1 RNA viral load determination in infants born of HIV-1-seropositive mothers from remote areas in Cameroon. The samples were collected between December 2007 and September 2010. Fourteen thousand seven hundred and sixty-three (14,763) DBS samples from infants born of HIV-positive mothers in 108 sites nationwide were tested for HIV. Of these, 1452 were positive on first PCR analyses (PCR1), giving an overall infection rate of 12.30%. We received only 475 DBS specimen for a second PCR testing (PCR2); out of these, 145 were positive. The median HIV-1 RNA viral load for 169 infant DBS samples tested was 6.85 log copies/ml, with values ranging from 3.37 to 8 log copies/ml. The determination of the viral load on the same DBS as that used for PCR1 allowed us to bypass the PCR2. The viral load values were high and tend to decrease with age but with a weak slope. The high values of viral load among these infants call for early and effective administration of antiretroviral therapy (ART). The findings from this study indicate that the use of DBS provides a powerful tool for perinatal screening programs, improvement on the testing algorithm, and follow-up during treatment, and thus should be scaled up to the entire nation. 相似文献
105.
Greve AM Olsen MH Bella JN Lønnebakken MT Gerdts E Okin PM Palmieri V Boman K Nieminen MS Omvik P Dahlöf B Devereux RB Wachtell K 《American journal of hypertension》2012,25(9):1017-1023
BackgroundPharmaceutical differences in central hemodynamics might influence cardiac response to antihypertensive treatment despite similar lowering of brachial blood pressure (BP).MethodsData from all patients with at least two echocardiographic examinations in the Losartan Intervention For Endpoint Reduction in Hypertension (LIFE) echocardiographic substudy (n = 801); high-risk patients on losartan- vs. atenolol-based antihypertensive therapy. Echocardiography was performed annually for 4 years to measure stroke index (SI), heart rate, cardiac index (CI), conduit artery stiffness assessed as pulse pressure/stroke index (PP/SI) and total peripheral resistance index (TPRI).ResultsAtenolol- and losartan-based therapy reduced BP similarly (cumulative difference in mean brachial blood pressure 0.3 mm Hg, P = 0.65). After 4 years the cumulative means of SI and heart rate were 1.8 ml/m(2) higher and 5.7 beats/min lower on atenolol-based treatment, respectively (both P < 0.001). This kept CI below baseline in atenolol-treated patients, whereas in the losartan group CI was unchanged from baseline throughout the study. TPRI was decreased more and remained lower in the losartan group (cumulative difference in mean TPRI 287 dynes/sec(-5)/cm/m(2), P < 0.001). These findings partly explained univariate differences in systolic- and diastolic function indices between the two treatments; fully adjusted losartan was only associated with a smaller left atrial diameter (cumulative mean difference 0.07 cm; 95% confidence intervals, -0.13 to -0.01, P = 0.03).ConclusionsContrasting hemodynamics impacted cardiac response to similar reductions in brachial BP on losartan- vs. atenolol-based therapy. The similar reduction of PP/SI suggests that the antihypertensive regimens used in the LIFE study had comparable effects on arterial stiffness (LIFE study; NCT00338260)American Journal of Hypertension, (2012); doi:10.1038/ajh.2012.81. 相似文献
106.
Lanier GM Vaishnava P Kosmas CE Wagman G Hiensch R Vittorio TJ 《Cardiology in review》2012,20(5):230-236
Diastolic dysfunction refers to abnormal diastolic filling properties of the left ventricle regardless of whether systolic function is normal or the patient has symptoms. Diastolic heart failure (HF), or more accurately, HF with preserved systolic function, is a distinct clinical entity characterized by the presence of the triad of impaired diastolic function, normal systolic function (left ventricular ejection fraction > 50%), and symptoms of HF. Patients with HF with preserved systolic function are frequently symptomatic from both acute and chronic elevations in left ventricular end-diastolic pressure and/or left atrial pressure. 相似文献
107.
Kelesidis I Mazurek J Khullar P Saeed W Vittorio T Zolty R 《Congestive heart failure (Greenwich, Conn.)》2012,18(3):158-164
The role of nesiritide in patients with decompensated heart failure with preserved ejection fraction (dHFpEF) has not been previously studied. In this investigation, the authors retrospectively analyzed the effect of nesiritide on renal function and clinical outcomes in patients admitted with dHFpEF. Of the 658 patients included, 328 were treated with nesiritide while 330 patients were treated with standard diuretic therapy. In both the nesiritide and no nesiritide groups, there was a significant change in mean glomerular filtration rate (GFR) and creatinine at 72 hours as well as at day of discharge (P<.001). This trend did not progress at 1 month in the nesiritide group, although it did in the no nesiritide group. At 1 month after therapy, however, there was a significant difference between the two groups in the mean change of GFR and creatinine (P<.001). There was no significant difference in >25% decrease of GFR anytime through day 30 (25% vs 29.69%, P=.236) between the two groups. On multivariate analysis, nesiritide was an important predictor of renal function at 1 month (P<.05). Thus, nesiritide can be administered safely without negatively impacting long-term renal function in patients admitted with dHFpEF. 相似文献
108.
Giorgio Minoli Paolo Borsato Enrico Colombo Aurora Bortoli Tino Casetti Giovanni de Pretis Luca Ferraris Ivano Lorenzini Alberto Meggio Rudy Meroni Lucia Piazzi Vittorio Terruzzi 《Digestive and liver disease》2012,44(11):914-918
Background
Not much is known about errors and near misses in digestive endoscopy.Aims
To verify whether an incident report, with certain facilitating features, gives useful information about unintended events, only excluding errors in medical diagnosis.Method
Nine endoscopy units took part in this cross sectional, prospective, multicentre study which lasted for two weeks. Members of the staff were required to report any unintended, potentially dangerous event observed during the daily work. A form was provided with a list of “reminders” and facilitators were appointed to help.The main outcome measurements were type of event, causes, corrective interventions, stage of occurrence in the workflow and qualification of the reporters.Results
A total of 232 errors were reported (two were not related to endoscopy). The remaining 230 amount to 10.3% of 2239 procedures; 66 (29%) were considered errors with consequences, 164 (71%) “near misses”. There were 150 pre-operative errors (65%), 22 operative (10%) and 58 post-operative (25%). Corrective interventions were provided for 60 cases of errors and 119 near misses. Most of the events were reported by the nurses (106 out of 232, 46%).Conclusions
Short-term incident reporting focusing on near misses, using forms with lists of “reminders”, and the help of a facilitator, can give useful information on errors and near misses in digestive endoscopy. 相似文献109.
Luigi Mearini Alessandro Zucchi Elisabetta Nunzi Tommaso Villirillo Vittorio Bini Massimo Porena 《World journal of urology》2013,31(2):247-252
Purpose
Although hormones play fundamental roles in prostate growth, their clinical significance is not completely clear. Aims of present study were to assess whether testosterone and serum sex hormone levels are predictors of benign prostatic hyperplasia (BPH) or prostate cancer (PC) and to verify whether prostate cancer is associated with low testosterone levels, and to test association between testosterone levels and known prognostic factors in prostate cancer.Methods
In 206 consecutive patients with benign prostatic hyperplasia or prostate cancer testosterone, follicle-stimulating hormone, luteinizing hormone and prolactin levels were tested and correlated with disease. In patients with prostate cancer, hormone levels were also correlated with known prognostic factors. Predictive value was assessed for age, prostate-specific antigen (PSA), PSA ratio, PSA density, prostate volume and serum sex hormone levels using multiple logistic regression analysis and receiver operating characteristic curves.Results
Considering sex hormones, only testosterone levels were significantly lower in patients with prostate cancer than those with BPH; testosterone levels appear to be independent predictor of prostate cancer, enhancing predictive accuracy for BPH and PC. Testosterone levels do not seem to be associated with known clinical prognostic factors.Conclusions
This study supports experimental findings that testosterone levels are predictor of prostate cancer and that prostate cancer is frequently associated with low testosterone levels. In the diagnostic work-up for prostate cancer, adding testosterone determination to PSA test may improve predictive accuracy. 相似文献110.
Massimo Lazzeri Alexander Haese Alexandre de la Taille Joan Palou Redorta Thomas McNicholas Giovanni Lughezzani Vincenzo Scattoni Vittorio Bini Massimo Freschi Amy Sussman Bijan Ghaleh Philippe Le Corvoisier Josep Alberola Bou Salvador Esquena Fernández Markus Graefen Giorgio Guazzoni 《European urology》2013