全文获取类型
收费全文 | 214598篇 |
免费 | 17645篇 |
国内免费 | 6853篇 |
专业分类
耳鼻咽喉 | 1250篇 |
儿科学 | 7591篇 |
妇产科学 | 1542篇 |
基础医学 | 18932篇 |
口腔科学 | 3599篇 |
临床医学 | 22746篇 |
内科学 | 54413篇 |
皮肤病学 | 2709篇 |
神经病学 | 25704篇 |
特种医学 | 6214篇 |
外国民族医学 | 4篇 |
外科学 | 16451篇 |
综合类 | 29838篇 |
现状与发展 | 31篇 |
一般理论 | 9篇 |
预防医学 | 17049篇 |
眼科学 | 2332篇 |
药学 | 14956篇 |
184篇 | |
中国医学 | 9906篇 |
肿瘤学 | 3636篇 |
出版年
2024年 | 222篇 |
2023年 | 4330篇 |
2022年 | 5821篇 |
2021年 | 10835篇 |
2020年 | 10926篇 |
2019年 | 8305篇 |
2018年 | 8225篇 |
2017年 | 8166篇 |
2016年 | 8492篇 |
2015年 | 8206篇 |
2014年 | 15561篇 |
2013年 | 17011篇 |
2012年 | 12726篇 |
2011年 | 13762篇 |
2010年 | 10829篇 |
2009年 | 10414篇 |
2008年 | 10427篇 |
2007年 | 10087篇 |
2006年 | 8985篇 |
2005年 | 7414篇 |
2004年 | 6304篇 |
2003年 | 5420篇 |
2002年 | 4561篇 |
2001年 | 3939篇 |
2000年 | 3264篇 |
1999年 | 2716篇 |
1998年 | 2436篇 |
1997年 | 2088篇 |
1996年 | 1858篇 |
1995年 | 1926篇 |
1994年 | 1773篇 |
1993年 | 1512篇 |
1992年 | 1452篇 |
1991年 | 1277篇 |
1990年 | 1011篇 |
1989年 | 858篇 |
1988年 | 804篇 |
1987年 | 732篇 |
1986年 | 633篇 |
1985年 | 736篇 |
1984年 | 617篇 |
1983年 | 379篇 |
1982年 | 446篇 |
1981年 | 374篇 |
1980年 | 282篇 |
1979年 | 247篇 |
1978年 | 184篇 |
1977年 | 164篇 |
1976年 | 135篇 |
1975年 | 49篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
31.
《Diagnostic Histopathology》2022,28(12):522-533
Neoplasms of bone with numerous non-neoplastic osteoclast type giant cells are relatively common and exhibit diverse phenotypes of the neoplastic cells. These tumors have a broad spectrum of biological potential which necessitates accurate recognition and diagnosis. Their clinicopathological features are overlapping, therefore, immunohistochemistry and molecular studies may be required for evaluation. Correlation with imaging studies provides additional information that should be incorporated into the pathological interpretation. 相似文献
32.
《介入医学杂志(英文)》2022,5(4):196-199
ObjectiveThis study aimed to analyze and evaluate the results of mid-term follow-up after fetal pulmonary valvuloplasty (FPV) in fetuses with pulmonary atresia with intact ventricular septum (PA/IVS).MethodsFrom August 31, 2018, to May 31, 2019, seven fetuses with PA/IVS and hypoplastic right heart were included in this study. All underwent echocardiography by the same specialist and were operated on by the same team. Intervention and echocardiography data were collected, and changes in the associated indices noted during follow-up were analyzed.ResultsAll seven fetuses successfully underwent FPV. The median gestational age at FPV was 27.54 weeks. The average FPV procedural time was 6 ?min. Persistent bradycardia requiring treatment occurred in 4/7 procedures. Finally, five pregnancies were successfully delivered, and the other two were aborted. Compared to data before fetal cardiac interventions (FCI), tricuspid valve annulus diameter/mitral valve annulus diameter (TV/MV) and right ventricle diameter/left ventricle diameter (RV/LV) of all fetuses had progressively improved. The maximum tricuspid regurgitation velocity decreased from 4.60 ?m/s to 3.64 ?m/s. The average follow-up time was 30.40 ?± ?2.05 months. During the follow-up period, the diameter of the tricuspid valve ring in five children continued to improve, and the development rate of the tricuspid valve was relatively obvious from 6 months to 1 year after birth. However, the development of the right ventricle after birth was relatively slow. It was discovered that there were individual variations in the development of the right ventricle during follow-up.ConclusionThe findings support the potential for the development of the right ventricle and tricuspid valve in fetuses with PA/IVS who underwent FCI. Development of the right ventricle and tricuspid valve does not occur synchronously during pregnancy. The right ventricle develops rapidly in utero, but the development of tricuspid valve is more apparent after birth than in utero. 相似文献
33.
34.
35.
《Nefrología : publicación oficial de la Sociedad Espa?ola Nefrologia》2022,42(3):301-310
Background and objectiveTo describe the clinical characteristics, the reasons for initiating therapy and the effects of treatment in the initial phase of evolocumab availability in the Nephrology Units of Spain.Material and methodsRetrospective, observational and multicentric study that included patients initiating treatment with evolocumab (from February 2016 to August 2018), in 15 Nephrology Units in Spain. The demographic and clinical characteristics of the patients, the lipid lowering treatment and the evolution of the lipid profiles between 24 weeks pre-initiation and 12 ± 4 weeks post-initiation of evolocumab were reviewed.ResultsSixty patients were enrolled: 53.3% women; mean (SD) age, 56.9 (12.8) years, 45.0% with familial hypercholesterolemia (FH) (5.0% homozygous and 40.0% heterozygous) and 65.0% with atherosclerotic cardiovascular (CV) disease. The mean (SD) eGFR was 62.6 (30.0) ml/min/1.73 m2 (51.7% of patients had eGFR < 60 ml/min/1.73 m2 [CKD stage > 2]), 50.0% had proteinuria (>300 mg/g) and 10.0% had nephrotic syndrome. Other CV risk factors were hypertension (75.0%), diabetes (25.0%), and smoking (21.7%). A 40.0% of patients were statin intolerant. At evolocumab initiation, 41.7% of patients were on a high-intensity statin, 18.3% on moderate intensity statin and 50.0% were receiving ezetimibe. Mean (SD) LDL-c at evolocumab initiation was 179.7 (62.9) mg/dL (53.4% of patients with LDL-c≥160 mg/dL and 29.3%≥190 mg/dL). After 12 weeks, evolocumab resulted in LDL-c reductions of 60.1%. At week 12, 90.0% of patients reached LDL-c levels <100 mg/dL, 70.0% <70 mg/dL, and 55.0% <55 mg/dL, while mean eGFR levels and statin use were remained stable.ConclusionIn Nephrology Units of Spain, evolocumab was predominantly prescribed in patients with FH, chronic renal disease (CRD>2) and secondary prevention, with LDL-c levels above those recommended by the guidelines. Evolocumab used in clinical practice significantly reduced the LDL-c levels in all patients included in the study. 相似文献
36.
37.
《Nutrition, metabolism, and cardiovascular diseases : NMCD》2022,32(4):908-917
Background and aimsReducing dietary cholesterol is generally acceptable for the prevention of cardiovascular disease (CVD). Eggs are nutrient-dense and common food items across the world, while rich in cholesterol. The potential effects of egg intake on cardiovascular health remain uncertainty and have been under debate in past decades.Methods and resultsA nationwide cohort of 20,688 participants aged 16–110 years without CVD at baseline were derived from the China Family Panel Studies. Egg consumption was assessed by a semi-quantitative food frequency questionnaire. We adopted stratified Cox proportional hazards model with random intercepts for provinces to evaluate associations of egg intake with CVD incidence. During a median follow-up of 6.0 years, we identified 2395 total CVD incidence and mean egg consumption was 3 times/week. Egg intakes were associated lower risks of CVD incidence in the multivariate-adjusted model. Compared with the non-consumers, the corresponding HRs (95% confidence interval) for total CVD events were 0.84 (0.74–0.94) for 1–2 times per week, 0.78 (0.69–0.88) for 3–6/week, and 0.83 (0.72–0.95) for ≥7/week. Similar relationships were found in hypertension. Approximately non-linear relationships were observed between egg consumption with total CVD and hypertension incidence, identifying the lowest risk in 3–6 times/week. Subgroup analyses estimated lower risks of total CVD and hypertension in females only, with significant effect modification by sex (P for interaction = 0.008 and 0.020).ConclusionEgg consumption may be associated with lower risks of CVD incidence among Chinese adults. Our findings could have implications in CVD prevention and might be considered in the development of dietary guidelines. 相似文献
38.
《Revista de gastroenterologia de Mexico》2022,87(2):159-169
Introduction and aimsCirrhosis is the common outcome of liver diseases. It can be decompensated and lead to the development of complications, such as encephalopathy. Hyperammonemia that develops due to liver dysfunction is etiopathologically related to hepatic encephalopathy. Caffeine increases the activity of the urea cycle in the liver, augmenting ammonia degradation. By antagonizing adenosine receptors, it also has a hepatoprotective effect, impeding the formation of fibrosis, as well as having a stimulating effect on the central nervous system. The present study analyzed the effects of caffeine on the progression of cholestatic liver fibrosis and hepatic encephalopathy.Materials and methodsAn experimental model of cholestatic liver fibrosis, through common bile duct ligature, and of hepatic encephalopathy, through the administration of a high-protein diet, was constructed. Male Wistar rats (n = 32) were equally divided into 4 groups. The experiment lasted 28 days, with the administration of 50 mg/kg/day of caffeine. Laboratory tests, histologic analyses of the liver and encephalon, open field tests (OFTs), and daily behavioral analyses were carried out.ResultsThe ligated animals treated with caffeine had lower mean transaminase levels and improved histologic aspects of the liver and encephalon. The untreated ligated animals were clearly lethargic and apathetic at the last week of the experiment, confirmed by reduced exploratory activity during the OFT.ConclusionCaffeine improved the microarchitecture of the liver and encephalon of the cirrhotic animals and prevented the decrease in exploratory behavior of the animals during the OFT. 相似文献
39.
姚峰 《中国工业医学杂志》2022,35(2):191-191