全文获取类型
收费全文 | 6658篇 |
免费 | 408篇 |
国内免费 | 34篇 |
专业分类
耳鼻咽喉 | 76篇 |
儿科学 | 228篇 |
妇产科学 | 202篇 |
基础医学 | 824篇 |
口腔科学 | 165篇 |
临床医学 | 506篇 |
内科学 | 1755篇 |
皮肤病学 | 117篇 |
神经病学 | 580篇 |
特种医学 | 157篇 |
外科学 | 1072篇 |
综合类 | 34篇 |
一般理论 | 1篇 |
预防医学 | 395篇 |
眼科学 | 90篇 |
药学 | 279篇 |
中国医学 | 18篇 |
肿瘤学 | 601篇 |
出版年
2023年 | 56篇 |
2022年 | 90篇 |
2021年 | 319篇 |
2020年 | 142篇 |
2019年 | 246篇 |
2018年 | 269篇 |
2017年 | 190篇 |
2016年 | 169篇 |
2015年 | 172篇 |
2014年 | 261篇 |
2013年 | 340篇 |
2012年 | 536篇 |
2011年 | 593篇 |
2010年 | 307篇 |
2009年 | 273篇 |
2008年 | 411篇 |
2007年 | 429篇 |
2006年 | 414篇 |
2005年 | 389篇 |
2004年 | 304篇 |
2003年 | 274篇 |
2002年 | 241篇 |
2001年 | 75篇 |
2000年 | 59篇 |
1999年 | 72篇 |
1998年 | 48篇 |
1997年 | 36篇 |
1996年 | 22篇 |
1995年 | 24篇 |
1994年 | 21篇 |
1993年 | 21篇 |
1992年 | 32篇 |
1991年 | 24篇 |
1990年 | 20篇 |
1989年 | 16篇 |
1988年 | 17篇 |
1987年 | 19篇 |
1986年 | 20篇 |
1985年 | 5篇 |
1984年 | 11篇 |
1983年 | 13篇 |
1981年 | 13篇 |
1980年 | 7篇 |
1979年 | 13篇 |
1978年 | 7篇 |
1977年 | 12篇 |
1976年 | 20篇 |
1975年 | 6篇 |
1974年 | 7篇 |
1969年 | 4篇 |
排序方式: 共有7100条查询结果,搜索用时 15 毫秒
1.
2.
3.
Tormo Nuria Giménez Estela Martínez-Navarro María Albert Eliseo Navalpotro David Torres Ignacio Gimeno Concepción Navarro David 《European journal of clinical microbiology & infectious diseases》2022,41(4):657-662
European Journal of Clinical Microbiology & Infectious Diseases - We compared the performance of an in-house-developed flow cytometry assay for intracellular cytokine staining (FC-ICS) and a... 相似文献
4.
Ana M. Gómez Angelica Imitola Diana Henao Maira García-Jaramillo Marga Giménez Clara Viñals Bruno Grassi Mariana Torres Isabella Zuluaga Oscar Mauricio Muñoz Martin Rondón Fabián León-Vargas Ignacio Conget 《Diabetes & Metabolic Syndrome: Clinical Research & Reviews》2021,15(1):267-272
Background and aimsDespite using sensor-augmented pump therapy (SAPT) with predictive low-glucose management (PLGM), hypoglycemia is still an issue in patients with type 1 Diabetes (T1D). Our aim was to determine factors associated with clinically significant hypoglycemia (<54 mg/dl) in persons with T1D treated with PLGM-SAPT.Methodology: This is a multicentric prospective real-life study performed in Colombia, Chile and Spain. Patients with T1D treated with PLGM-SAPT, using sensor ≥70% of time, were included. Data regarding pump and sensor use patterns and carbohydrate intake from 28 consecutive days were collected. A bivariate and multivariate Poisson regression analysis was carried out, to evaluate the association between the number of events of <54 mg/dl with the clinical variables and patterns of sensor and pump use.Results188 subjects were included (41 ± 13.8 years-old, 23 ± 12 years disease duration, A1c 7.2% ± 0.9). The median of events <54 mg/dl was four events/patient/month (IQR 1–10), 77% of these events occurred during day time. Multivariate analysis showed that the number of events of hypoglycemia were higher in patients with previous severe hypoglycemia (IRR1.38; 95% CI 1.19–1.61; p < 0.001), high glycemic variability defined as Coefficient of Variation (CV%) > 36% (IRR 2.09; 95%CI 1.79–2.45; p < 0.001) and hypoglycemia unawareness. A protector effect was identified for adequate sensor calibration (IRR 0.77; 95%CI 0.66–0.90; p:0.001), and the use of bolus wizard >60% (IRR 0.74; 95%CI 0.58–0.95; p:0.017).ConclusionIn spite of using advanced SAPT, clinically significant hypoglycemia is still a non-negligible risk. Only the identification and intervention of modifiable factors could help to prevent and reduce hypoglycemia in clinical practice. 相似文献
5.
6.
The role of adenosine in the vascular adaptation of neonatal cerebral blood flow during hypotension 总被引:1,自引:0,他引:1
N Laudignon K Beharry E Farri J V Aranda 《Journal of cerebral blood flow and metabolism》1991,11(3):424-431
This study investigated the potential role of adenosine in cerebral blood flow (CBF) regulation in the neonate during moderate and severe hypotension. Experiments were done in anesthetized, 1- to 3-day-old piglets. Regional CBF (determined by radiolabeled microsphere technique) and cerebral metabolic rate for O2 (CMRO2) were measured (a) during normotension and (b) during a 3-min period of moderate (58 +/- 9 mm Hg) or severe (36 +/- 7 mm Hg) hypotension produced by the inflation of a balloon catheter placed in the aortic root. Measurements of CBF and CMRO2 were performed successively after intracerebroventricular (i.c.v.) injections of vehicle (n = 17), the adenosine receptor blocker 8-phenyltheophylline (8-PT, 10 micrograms, n = 14), and the A2-receptor agonist 5'-N-(ethylcarboxamide)adenosine (NECA, 2 ng, n = 8). After i.c.v. administration of vehicle, none of the parameters studied was significantly altered by moderate hypotension, but severe hypotension decreased the total CBF (mean +/- SD) from 86 +/- 24 to 40 +/- 15 ml min-1 100 g-1 and CMRO2 from 3.2 +/- 0.8 to 1.8 +/- 1.0 ml min-1 100 g-1 (p less than 0.05). Administration of 8-PT did not alter these parameters during normotension, but significantly decreased CBF during moderate hypotension compared to postvehicle values (53 +/- 11 versus 81 +/- 12 ml min-1 100 g-1, p less than 0.05). This loss of autoregulation was completely reversed by NECA. During severe hypotension, 8-PT altered the CBF redistribution towards the brainstem.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
7.
Ignacio Lopez Escolastico Aguilera-Tejero Arnold J Felsenfeld Jose Carlos Estepa Mariano Rodriguez 《Journal of bone and mineral research》2002,17(9):1691-1700
Because both metabolic (Met Acid) and respiratory acidosis (Resp Acid) have diverse effects on mineral metabolism, it has been difficult to establish whether acidosis directly affects parathyroid hormone (PTH) secretion. Our goal was to determine whether acute Met Acid and Resp Acid directly affected PTH secretion. Three groups of dogs were studied: control, acute Met Acid induced by HCl infusion, and acute Resp Acid induced by hypoventilation. EDTA was infused to prevent acidosis-induced increases in ionized calcium, but more EDTA was needed in Met Acid than in Resp Acid. The PTH response to EDTA-induced hypocalcemia was evaluated also. Magnesium needed to be infused in groups receiving EDTA to prevent hypomagnesemia. The half-life of intact PTH (iPTH) was determined during hypocalcemia when PTH was measured after parathyroidectomy. During normocalcemia, PTH values were greater (p < 0.05) in Met Acid (92 +/- 19 pg/ml) and Resp Acid (77 +/- 22 pg/ml) than in controls (27 +/- 5 pg/ml); the respective pH values were 7.23 +/- 0.01, 7.24 +/- 0.01, and 7.39 +/- 0.02. The maximal PTH response to hypocalcemia was greater (p < 0.05) in Met Acid (443 +/- 54 pg/ml) than in Resp Acid (267 +/- 37 pg/ml) and controls (262 +/- 48 pg/ml). The half-life of PTH was greater (p < 0.05) in Met Acid than in controls, but the PTH secretion rate also was greater (p < 0.05) in Met Acid than in the other two groups. In conclusion, (1) both acute Met Acid and Resp Acid increase PTH secretion when the ionized calcium concentration is normal; (2) acute Met Acid may increase the bone efflux of calcium more than Resp Acid; (3) acute Met Acid acts as a secretogogue for PTH secretion because it enhances the maximal PTH response to hypocalcemia. 相似文献
8.
D Mezzano G E del Pino M Montesinos M E García E Aranda A Foradori 《Thrombosis and haemostasis》1991,66(2):254-258
Thrombocytopenia was induced in mongrel dogs by two mechanisms: immunologically, by intravenous injection of heterologous antiplatelet antibody, and non-immunologically, by circulating the blood through glass beads in anesthetized animals. The platelet content of 5-HT was monitored before and during the recovery of the blood platelet counts. This period is associated with the normalization of the mean platelet survival time and with a progressive increase in the mean age of the circulating platelet population. A continuous increment in platelet 5-HT closely followed the increase in platelet counts in both models of thrombocytopenia, and a strong correlation was found between the platelet age and 5-HT content. These findings support the concept that platelets accumulate 5-HT during their physiological aging process, contradicting the notion that a negative balance in 5-HT content results at the end of their physiological lifespan in circulation. These results are not in conflict with the concept that circulating platelets release and re-uptake 5-HT. 相似文献
9.
10.