全文获取类型
收费全文 | 1443篇 |
免费 | 86篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 18篇 |
儿科学 | 35篇 |
妇产科学 | 39篇 |
基础医学 | 133篇 |
口腔科学 | 20篇 |
临床医学 | 167篇 |
内科学 | 368篇 |
皮肤病学 | 12篇 |
神经病学 | 92篇 |
特种医学 | 73篇 |
外科学 | 370篇 |
综合类 | 5篇 |
预防医学 | 65篇 |
眼科学 | 4篇 |
药学 | 68篇 |
中国医学 | 2篇 |
肿瘤学 | 69篇 |
出版年
2023年 | 10篇 |
2022年 | 21篇 |
2021年 | 40篇 |
2020年 | 27篇 |
2019年 | 35篇 |
2018年 | 50篇 |
2017年 | 29篇 |
2016年 | 38篇 |
2015年 | 40篇 |
2014年 | 68篇 |
2013年 | 72篇 |
2012年 | 129篇 |
2011年 | 144篇 |
2010年 | 71篇 |
2009年 | 77篇 |
2008年 | 123篇 |
2007年 | 116篇 |
2006年 | 104篇 |
2005年 | 84篇 |
2004年 | 79篇 |
2003年 | 61篇 |
2002年 | 51篇 |
2001年 | 7篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1998年 | 5篇 |
1997年 | 6篇 |
1996年 | 5篇 |
1995年 | 1篇 |
1994年 | 4篇 |
1993年 | 5篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1975年 | 3篇 |
1974年 | 1篇 |
1973年 | 4篇 |
1971年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有1540条查询结果,搜索用时 15 毫秒
31.
Konstantinos N. Fountoulakis Christos Savopoulos Melina Siamouli Eleni Zaggelidou Stamatia Mageiria Apostolos Iacovides Apostolos I. Hatzitolios 《European archives of psychiatry and clinical neuroscience》2013,263(5):441-444
For the decade 2000–2010, suicidal rates appear to be both low and stable in Greece and unrelated to the socioeconomic environment. It is highly possible that the recent crisis caused a significant increase in dysphoria, stress, depression and maybe suicidal ideation in the general population, but completed suicides do not seem to have increased so far. Measures are needed to make sure there will be no increase in completed suicides in the near future, since historically, periods of socioeconomic instability might be related to increased suicidality. Community interventions reduce stigma and enhance help-seeking. However, only those including the creation of social support networks are essential in the fight against suicidality. 相似文献
32.
Panayiota Papasozomenou Apostolos P. Athanasiadis Menelaos Zafrakas Eleftherios Panteris Themistokles Mikos Angelos Daniilidis 《The journal of maternal-fetal & neonatal medicine》2016,29(20):3368-3373
Objective: To evaluate different methods of defining fetal nasal bone hypoplasia in the second trimester for the detection of trisomy 21.Methods: Prospective study in Greek women undergoing anomaly scan between 18?+?0 and 23?+?6 weeks. The following methods of defining nasal bone hypoplasia were evaluated, either as a single marker or in combination with others: (1) BPD to nasal bone length (NBL) ratio; (2) multiples of the median (MoM) of NBL, according to normal curves from a Greek population; (3–4) NBL?<?2.5 percentile according to normal curves (3) commonly used internationally curves and (4) curves from a Greek population.Results: In total, 1301 singleton fetuses were evaluated???10 with trisomy 21. The best detection rate of trisomy 21 was achieved when the applied method was nasal bone percentiles adjusted to maternal ethnicity, in combination with other markers (<2.5 percentile according to normal curves from a Greek population; p?<?0.001; sensitivity 50%; specificity 94.8%; false-positive rate 5.2%; positive likelihood ratio 9.6).Conclusion: Screening performance of fetal nasal bone hypoplasia in detecting trisomy 21 varies according to the method applied. The best screening performance is achieved by using percentiles adjusted to maternal ethnicity in combination with other markers of aneuploidy. 相似文献
33.
34.
Recent advances in social science surveys include collection of biological samples. Although biomarkers offer a large potential for social science and economic research, they impose a number of statistical challenges, often being distributed asymmetrically with heavy tails. Using data from the UK Household Panel Survey, we illustrate the comparative performance of a set of flexible parametric distributions, which allow for a wide range of skewness and kurtosis: the four‐parameter generalized beta of the second kind (GB2), the three‐parameter generalized gamma, and their three‐, two‐, or one‐parameter nested and limiting cases. Commonly used blood‐based biomarkers for inflammation, diabetes, cholesterol, and stress‐related hormones are modelled. Although some of the three‐parameter distributions nested within the GB2 outperform the latter for most of the biomarkers considered, the GB2 can be used as a guide for choosing among competing parametric distributions for biomarkers. Going “beyond the mean” to estimate tail probabilities, we find that GB2 performs fairly well with some disparities at the very high levels of glycated hemoglobin and fibrinogen. Commonly used linear models are shown to perform worse than almost all the flexible distributions. 相似文献
35.
Koroneos A Politis P Malachias S Manolis AS Vassilakopoulos T 《Intensive care medicine》2007,33(8):1458-1462
Objective Mechanically ventilated patients in the intensive care unit cannot cooperate to perform the Valsalva maneuver during echocardiography
for detection of patent foramen ovale. We evaluated the effectiveness of the end-inspiratory occlusion maneuver to enhance
detection of patent foramen ovale in this patient population.
Design Prospective interventional study.
Setting The 40-bed intensive care unit of a university hospital.
Patients and participants Twenty five sedated and mechanically ventilated intensive care unit patients referred by their attending physician for bedside
transesophageal echocardiography and agitated saline contrast study for detection of patent foramen ovale.
Intervention Agitated saline contrast study with end-inspiratory occlusion maneuver.
Measurements and results All patients underwent a complete transesophageal echocardiographic study without any complications. Reduction in right atrial
cross-sectional area (from 15.80 ± 6.08 cm2 to 12.40 ± 4.63 cm2; p < 0.001) and interatrial septum deviation during the maneuver were recorded in all patients. Microbubbles imaged in the left
atrium within three cardiac cycles after injection of agitated saline diagnosed patent foramen ovale in three patients. When
end-inspiratory occlusion maneuver was added, patent foramen ovale was diagnosed in seven patients (McNemar χ2 = 9.33, p = 0.0023).
Conclusions The end-inspiratory occlusion maneuver enhances the sensitivity of transesophageal echocardiography with agitated saline contrast
study for diagnosing intermittent patent foramen ovale in critically ill mechanically ventilated patients.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
36.
The role of adipocytokines in insulin resistance in normal pregnancy: visfatin concentrations in early pregnancy predict insulin sensitivity 总被引:1,自引:0,他引:1
Mastorakos G Valsamakis G Papatheodorou DC Barlas I Margeli A Boutsiadis A Kouskouni E Vitoratos N Papadimitriou A Papassotiriou I Creatsas G 《Clinical chemistry》2007,53(8):1477-1483
BACKGROUND: Throughout pregnancy maternal adipose tissue is metabolically active, producing adipocytokines involved in the process of insulin resistance. We explored the role of serum adipocytokines, including the newly identified adipocytokine visfatin, in the process of insulin resistance in normal pregnancy. METHODS: We examined 80 pregnant nonobese, nondiabetic white women during the 3 trimesters of pregnancy. All study participants underwent anthropometric measurements, adipocytokine evaluation, and a 75-g oral glucose tolerance test. Homeostasis mathematical model assessment (HOMA-R), insulin sensitivity index (ISI), and indices of beta-cell secretion were calculated. RESULTS: Maternal weight, percentage total body fat, hip circumference, and indices of beta-cell secretion increased significantly during the 3 trimesters, and HOMA-R and ISI increased and decreased, respectively, in the 3rd trimester. During early pregnancy, insulin resistance, beta-cell secretion, and weight correlated positively with leptin. During the 1st trimester, visfatin correlated negatively with percentage body fat and was the best positive predictor of 2nd trimester ISI. In the 2nd trimester, serum visfatin was the best negative predictor of percentage body fat. CONCLUSIONS: During normal pregnancy of nonobese, nondiabetic women, adipose tissue increases, accompanied by a significant progressive increase of insulin resistance. Visfatin concentrations in the 1st trimester positively predict insulin sensitivity during the 2nd trimester. Body fat mass during 1st trimester of pregnancy is negatively associated with insulin sensitivity during the 2nd trimester and perhaps should be kept under control. 相似文献
37.
38.
Asimina Valsamaki Maria Xanthoudaki Katerina G Oikonomou Panagiotis J Vlachostergios Antonios Papadogoulas Periklis Katsiafylloudis Ioanna Voulgaridi Apostolia-Lemonia Skoura Apostolos Komnos Panagiotis Papamichalis 《World Journal of Clinical Cases》2023,11(3):514-527
Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2, broke out in December 2019 in Wuhan city of China and spread rapidly worldwide. Therefore, by March 2020, the World Health Organization declared the disease a global pandemic. Apart from the respiratory system, various other organs of the human body are also seriously affected by the virus. Liver injury in patients with a severe form of COVID-19 is estimated to be 14.8%-53.0%. Elevated levels of total bilirubin, aspartate aminotransferase and alanine aminotransferase and low levels of serum albumin and prealbumin are the main laboratory findings. Patients with pre-existing chronic liver disease and cirrhosis are much more prone to develop severe liver injury. This literature review presented the recent scientific findings regarding the pathophysiological mechanisms responsible for liver injury in critically ill patients with COVID-19, the various interactions between drugs used to treat the disease and the function of the liver and the specific tests providing the possibility of early diagnosis of severe liver injury in these patients. Moreover, it highlighted the burden that COVID-19 put on health systems worldwide and its effect on transplant programs and the care provided to critically ill patients in general and particularly to those with chronic liver disease. 相似文献
39.
Farmakis Dimitrios Chrysohoou Christina Giamouzis Gregory Giannakoulas George Hamilos Michalis Naka Katerina Tzeis Stylianos Xydonas Sotirios Karavidas Apostolos Parissis John 《Heart failure reviews》2021,26(6):1345-1358
Heart Failure Reviews - Heart failure (HF) and atrial fibrillation (AF) often coexist, being closely interrelated as the one increases the prevalence and incidence and worsens the prognosis of the... 相似文献
40.
Wei-Jia Li Paraschos Archontakis-Barakakis Leonidas Palaiodimos Dimitrios Kalaitzoglou Lazaros Tzelves Apostolos Manolopoulos Yu-Chiang Wang Stefanos Giannopoulos Robert Faillace Damianos G Kokkinidis 《World journal of cardiology》2021,13(4):82-94
BACKGROUNDMost of the randomized clinical trials that led to the wide use of non-vitamin K antagonist oral anticoagulants for stroke prevention in patients with atrial fibrillation (AF) originated from western countries. AIMTo systematically review and quantitatively synthesize the real-world data regarding the efficacy and safety of dabigatran, rivaroxaban, and apixaban compared to warfarin for stroke prevention in Asian patients with non-valvular AF.METHODSMedline, Cochrane, and ClinicalTrial.gov databases were reviewed. A random-effect model meta-analysis was used and I-square was utilized to assess the heterogeneity. The primary outcome was ischemic stroke. The secondary outcomes were all-cause mortality, major bleeding, intracranial hemorrhage, and gastrointestinal bleeding.RESULTSTwelve studies from East Asia or Southeast Asia and 441450 patients were included. Dabigatran, rivaroxaban, and apixaban were associated with a significant reduction in the incidence of ischemic stroke [hazard ratio (HR) = 0.78, 95% confidence interval (CI): 0.65-0.94; HR = 0.79, 95%CI: 0.74-0.85, HR = 0.70, 95%CI: 0.62-0.78; respectively], all-cause mortality (HR = 0.68, 95%CI: 0.56-0.83; HR = 0.66, 95%CI: 0.52-0.84; HR = 0.66, 95%CI: 0.49-0.90; respectively), and major bleeding (HR = 0.61, 95%CI: 0.54-0.69; HR = 0.70, 95%CI: 0.54-0.90; HR = 0.58, 95%CI: 0.43-0.78; respectively) compared to warfarin.CONCLUSIONDabigatran, rivaroxaban, and apixaban appear to be superior to warfarin in both efficacy and safety in Asians with non-valvular AF. 相似文献