全文获取类型
收费全文 | 125923篇 |
免费 | 9875篇 |
国内免费 | 3532篇 |
专业分类
耳鼻咽喉 | 203篇 |
儿科学 | 4127篇 |
妇产科学 | 882篇 |
基础医学 | 5906篇 |
口腔科学 | 680篇 |
临床医学 | 20856篇 |
内科学 | 41315篇 |
皮肤病学 | 463篇 |
神经病学 | 2550篇 |
特种医学 | 2988篇 |
外国民族医学 | 6篇 |
外科学 | 12650篇 |
综合类 | 21008篇 |
现状与发展 | 16篇 |
一般理论 | 2篇 |
预防医学 | 5142篇 |
眼科学 | 619篇 |
药学 | 10877篇 |
126篇 | |
中国医学 | 5792篇 |
肿瘤学 | 3122篇 |
出版年
2024年 | 337篇 |
2023年 | 2385篇 |
2022年 | 3987篇 |
2021年 | 6050篇 |
2020年 | 5490篇 |
2019年 | 4737篇 |
2018年 | 4409篇 |
2017年 | 4039篇 |
2016年 | 4195篇 |
2015年 | 4398篇 |
2014年 | 8402篇 |
2013年 | 8691篇 |
2012年 | 6771篇 |
2011年 | 7729篇 |
2010年 | 6165篇 |
2009年 | 5942篇 |
2008年 | 5971篇 |
2007年 | 6190篇 |
2006年 | 5548篇 |
2005年 | 5254篇 |
2004年 | 4366篇 |
2003年 | 3955篇 |
2002年 | 2877篇 |
2001年 | 2714篇 |
2000年 | 2212篇 |
1999年 | 1929篇 |
1998年 | 1675篇 |
1997年 | 1604篇 |
1996年 | 1421篇 |
1995年 | 1236篇 |
1994年 | 1157篇 |
1993年 | 882篇 |
1992年 | 826篇 |
1991年 | 748篇 |
1990年 | 616篇 |
1989年 | 570篇 |
1988年 | 548篇 |
1987年 | 444篇 |
1986年 | 401篇 |
1985年 | 485篇 |
1984年 | 394篇 |
1983年 | 269篇 |
1982年 | 290篇 |
1981年 | 235篇 |
1980年 | 191篇 |
1979年 | 169篇 |
1978年 | 128篇 |
1977年 | 84篇 |
1976年 | 83篇 |
1975年 | 40篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
Shinhiro Takeda Kazuhiro Nakanishi Teruo Takano Gen Ishikawa Ryo Ogawa 《Journal of anesthesia》1997,11(2):83-87
Effective gas exchange can be maintained in animals without endotracheal intubation using external high-frequency oscillation
(EHFO). The aim of this study was to evaluate the effect of EHFO in patients with respiratory failure due to severe cardiogenic
pulmonary edema. Seven patients were ventilated with EHFO for 2h at 60 oscillations·min−1, with a cuiras pressure of 36 cmH2O (−26 to +10) and an inspiratory to expiratory ratio of 1:1, with EHFO. Blood gas values and hemodynamic parameters were
measured. Significant increases were noted in cardiac index (2.3±0.5 to 2.5±0.5 l·m−2;P<0.05), stroke volume index (24±7 to 28±8 ml·m−2;P<0.05), and arterial O2 pressure (Pao2) (70±4 to 95±23 mmHg;P<0.01) without a change in pulmonary artery wedge pressure at 1 h after EHFO. The respiratory rate decreased from 28±3 to
22 ±3 breaths·min−1 at 5 min after the termination of EHFO (P <0.01). Arterial CO2 pressure (Paco2) did not, however, decrease. Increased stroke volume without a change in pulmonary artery wedge pressure (preload) suggests
either improved inotropic function of the left ventricle or reduced left ventricular afterload with EHFO. The use of EHFO
may be effective not only for gas exchange but also for left ventricular function in patients with severe cardiogenic pulmonary
edema. 相似文献
62.
选用标化成年雄性Wistar大鼠、以放射免疫测定法(RIA),研究了大鼠由平原引入高海拔环境后,在24小时急性司服期,垂体及各脑区内β-内啡肪样免疫活性物质(β-EPLI)的含量变化。结果表明,大鼠引入高海拔环境后脑内β-EP含量发生明显的动态变化。高海拔实验组与平原对照组相比,垂体内β-EP含量降低非常显著(P<0.01)。纹状体、下丘脑、丘脑、桥延、海马、皮层内β-EP含量增加非常显著(P<0.01)。中脑内β-EP含量虽然也增加,统计学处理无显著性意义(P>0.05)。据此推测:大鼠急进高海拔低氧环境后垂体β-EP的分泌与释放受到影响。提示,脑内β-EP参与低氧的应激反应过程,可能作为神经递质和调质,通过神经──内分泌环路在应激反应中起介导作用,β-EP可能为中枢神经系统内调节应激反应的主要应激激素之一。 相似文献
63.
The influence of anaesthetic techniques and type of delivery on peripartum serum interleukin-6 concentrations 总被引:2,自引:0,他引:2
R. F. DE JONGH E. P. BOSMANS M. J. PUYLAERT W. U. OMBELET H. J. VANDEPUT R. A. BERGHMANS M. MAES R. J. HEYLEN 《Acta anaesthesiologica Scandinavica》1997,41(7):853-860
Background: Interleukin-6 is a pleiotropic cytokine with a wide range of physiological activities. It plays an important role in the immuno-neuro-humoral axis during stress and surgery.
Methods: Serum interleukin-6 in parturients was measured on hospital admission, immediately after birth and 12 and 24 hours later. All parturients had uncomplicated pregnancies, and delivered vaginally without (n=31) or with (n=20) epidural analgesia, or underwent Caesarean section under epidural (n=20) or general (n=10) anaesthesia.
Results: Serum interleukin-6 assayed immediately following Caesarean section was low, but peaked 12 hours later, irrespective of the anaesthetic technique or other foetomaternal characteristics. Patients who delivered vaginally showed the highest interleukin-6 levels immediately after delivery. These were positively correlated with serum interleukin-6 on admission and duration of labour. Serum interleukin-6 was significantly higher in parturients who had epidural analgesia, and was significantly lower in those receiving intravaginal prostaglandins compared to those without prostaglandins.
Conclusion: The interleukin-6 response after Caesarean section can be explained by a generalized acute phase response to surgery, with no anaesthetic, maternal or neonatal interference. The rapid increase in peripartum serum interleukin-6 levels after vaginal delivery reflects, in part, cervical ripening or labour, their physiological triggers and psychological or physical stress. Regional anaesthesia, duration of labour and exogenous prostaglandin administration can modulate the peripartum interleukin-6 response and subsequently the physiological effects of this cytokine. 相似文献
Methods: Serum interleukin-6 in parturients was measured on hospital admission, immediately after birth and 12 and 24 hours later. All parturients had uncomplicated pregnancies, and delivered vaginally without (n=31) or with (n=20) epidural analgesia, or underwent Caesarean section under epidural (n=20) or general (n=10) anaesthesia.
Results: Serum interleukin-6 assayed immediately following Caesarean section was low, but peaked 12 hours later, irrespective of the anaesthetic technique or other foetomaternal characteristics. Patients who delivered vaginally showed the highest interleukin-6 levels immediately after delivery. These were positively correlated with serum interleukin-6 on admission and duration of labour. Serum interleukin-6 was significantly higher in parturients who had epidural analgesia, and was significantly lower in those receiving intravaginal prostaglandins compared to those without prostaglandins.
Conclusion: The interleukin-6 response after Caesarean section can be explained by a generalized acute phase response to surgery, with no anaesthetic, maternal or neonatal interference. The rapid increase in peripartum serum interleukin-6 levels after vaginal delivery reflects, in part, cervical ripening or labour, their physiological triggers and psychological or physical stress. Regional anaesthesia, duration of labour and exogenous prostaglandin administration can modulate the peripartum interleukin-6 response and subsequently the physiological effects of this cytokine. 相似文献
64.
65.
66.
肌钙蛋白T在诊断急性心肌梗死中的应用 总被引:2,自引:0,他引:2
采用肌钙蛋白T半定量试纸条检测急性心肌梗死16例,心绞痛13例,以20例健康体检者为对照组。结果显示,AMI组阳性反应15例,心绞组仅1例阳性,对照组均为阴性,结果提示,TnT半定量试纸条检测法在AMI诊断中,敏感性和特异性较高,方法简便方便,尤其适用于急诊室,内科监护病房及基层医院使用。 相似文献
67.
Myocardial cooling and right ventricular function in patients with right coronary artery disease: antegrade vs. retrograde cardioplegia 总被引:1,自引:0,他引:1
E. L. HONKONEN L. KAUKINEN E. J. PEHKONEN S. KAUKINEN 《Acta anaesthesiologica Scandinavica》1997,41(2):287-296
Background: Protection of the right ventricular (RV) myocardium during ischaemia in cardiac surgery is difficult, especially in patients with severe right coronary artery (RCA) disease. Retrograde coronary sinus cardioplegia is thought to distribute uniformly, but doubts still remain as to its adequacy in RV preservation. This study evaluated distribution of antegrade vs. exclusively retrograde coronary sinus cold blood cardioplegia by assessing myocardial cooling and compared the effects on RV function. Methods: Fifty-eight patients scheduled for elective coronary artery surgery - 29 patients with significant RCA disease and another 29 with no significant RCA stenosis (controls) - were randomised to receive either antegrade or retrograde cold blood cardioplegia through either aortic root or conventional self-inflating coronary sinus catheter (RCA-ante, RCA-retro, C-ante and C-retro groups). RV function was assessed by fast-response thermodilution. Myocardial temperatures were measured in the anterior and posterior wall of the right and left ventricle. Results: Cooling of the posterior wall of the RV was effective only in the control patients given antegrade cardioplegia (14.7°C), whereas in the other groups the lowest myocardial temperatures there remained above 20°C (RO.001). In patients with obstructed RCA both antegrade and retrograde cold cardioplegia led to uneven cooling of the myocardium. After cardiopulmonary bypass the RV ejection fraction (RVEF), RV stroke work index (RVSWI) and cardiac index (CI) were significantly reduced in the RCA-retro group, and RVSWI and CI in the C-retro group, too. Regression analysis showed an inverse relationship between the temperatures of the posterior walls of the ventricles and changes in the RVEF and CI. Conclusions: Retrograde and antegrade cardioplegia alone were not effective in reducing the temperature of the posterior wall of the RV in the patients with obstructed RCA, in whom with retrograde cardioplegia RV haemodynamics were impaired for 1 hour following bypass. Neither retrograde nor antegrade cardioplegia alone can be relied on to protect the posterior wall of the RV in the patients with obstructed RCA. 相似文献
68.
1986~1992年我院共收治急性发作期慢性肺心病196例,其中因严重肺部感染发生多器官衰竭(MOF)者70例(35.7%),平均受损脏器2.5个,死亡26例,总病死率为37.1%。其中2和3个脏器受损者的病死率分别为20.1%和44.4%,而4和5个脏器受损者则均死亡。血气分析显示pH和PaO2值与受损脏器数目呈负相关,而PaCO2值与受损脏器数目呈正相关。本文讨论了肺心病因肺部感染并发MOF的发病机理,并提出防治的措施。 相似文献
69.
Glutamine and Other Amino Acid Losses During Continuous Venovenous Hemodiafiltration 总被引:2,自引:0,他引:2
I. Novák V. rámek H. Pittrová Z. Ruavý P. Têinský S. Lacigová M. Eiselt L. Kohoutková E. Veselá K. Opatrný Jr. 《Artificial organs》1997,21(5):359-363
Abstract: Serum amino grams and daily losses of glutamine (Gin) and other amino acids (AAs) into diafiltrate were measured during the first 5 days of continuous venovenous hemodiafiltration (CVVHDF) in 6 ICU patients with acute renal failure (ARF). Four patients had ARF as a part of multiple organ failure (MOF) of septic origin, and 2 patients had isolated ARF because of primary renal disease. During the study, all the patients received defined total parenteral nutrition (TPN). The mean daily AA losses into dialysate were relatively low (0.61 ± 0.1 g N ) and reached 4.5% of the daily AA substitution. Gln represented 32.7 ± 5.9% of the total AA losses (0.19 ± 0.04 g N ). Serum levels of Gin (p = 0.002) and of most other AAs were significantly lower in the patients than in the control subjects (AA analysis in 16 healthy volunteers). Phenylalanine (Phe) was the only AA that was increased significantly (p < 0.01) in the patients. The mean patient serum concentrations of Phe and tyrosine were significantly higher (p < 0.03) than the correspondent concentrations in dialysate, but the lysine concentration was higher in dialysate (p < 0.03). The serum and dialysate concentrations of other AAs did not differ. Gin in serum decreased significantly (p < 0.03) on the second day of CVVHDF but returned to the baseline levels subsequently. Serum concentrations of Phe increased on the second day of CVVHDF (p < 0.05). Serum concentrations of other AAs remained stable during the whole study. We conclude that Gin losses into dialysate during CVVHDF are relatively low, but CVVHDF itself may induce changes in Gin metabolism and distribution that are reflected by a decrease of serum Gin levels at the institution of this treatment. Therefore, the need for Gin supplementation in ICU patients is even greater in the first days of CVVHDF. 相似文献
70.
Distinguishment of A 42 Capsomere Structure of Icosohedral Virion from A 32 One by Electron Microsco
DistinguishmentofA42CapsomereStructureofIcosohedralVirionfromA32OnebyElectronMicroscopeCnenBingying(陈丙莺);ZhouTong(周)(Departme... 相似文献