全文获取类型
收费全文 | 2298158篇 |
免费 | 177425篇 |
国内免费 | 5861篇 |
专业分类
耳鼻咽喉 | 32128篇 |
儿科学 | 75275篇 |
妇产科学 | 64882篇 |
基础医学 | 324589篇 |
口腔科学 | 66573篇 |
临床医学 | 200975篇 |
内科学 | 448926篇 |
皮肤病学 | 48734篇 |
神经病学 | 184240篇 |
特种医学 | 91966篇 |
外国民族医学 | 773篇 |
外科学 | 350998篇 |
综合类 | 60833篇 |
现状与发展 | 10篇 |
一般理论 | 769篇 |
预防医学 | 175627篇 |
眼科学 | 53260篇 |
药学 | 171638篇 |
39篇 | |
中国医学 | 6336篇 |
肿瘤学 | 122873篇 |
出版年
2018年 | 22282篇 |
2016年 | 19371篇 |
2015年 | 22739篇 |
2014年 | 31543篇 |
2013年 | 47830篇 |
2012年 | 64546篇 |
2011年 | 68243篇 |
2010年 | 40994篇 |
2009年 | 39190篇 |
2008年 | 64879篇 |
2007年 | 68539篇 |
2006年 | 69160篇 |
2005年 | 67212篇 |
2004年 | 65333篇 |
2003年 | 62674篇 |
2002年 | 61381篇 |
2001年 | 104801篇 |
2000年 | 108228篇 |
1999年 | 91856篇 |
1998年 | 25409篇 |
1997年 | 23212篇 |
1996年 | 22975篇 |
1995年 | 22145篇 |
1994年 | 20841篇 |
1993年 | 19715篇 |
1992年 | 74875篇 |
1991年 | 72501篇 |
1990年 | 70866篇 |
1989年 | 68650篇 |
1988年 | 63779篇 |
1987年 | 62883篇 |
1986年 | 60073篇 |
1985年 | 57738篇 |
1984年 | 43348篇 |
1983年 | 37107篇 |
1982年 | 22001篇 |
1981年 | 19519篇 |
1980年 | 18451篇 |
1979年 | 40896篇 |
1978年 | 28534篇 |
1977年 | 24007篇 |
1976年 | 22676篇 |
1975年 | 24310篇 |
1974年 | 29544篇 |
1973年 | 28409篇 |
1972年 | 26281篇 |
1971年 | 24614篇 |
1970年 | 22958篇 |
1969年 | 21524篇 |
1968年 | 20002篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
C F A Peralta P Cavoretto B Csapo O Falcon K H Nicolaides 《Ultrasound in obstetrics & gynecology》2006,27(2):128-133
OBJECTIVE: To establish reference intervals for the fetal right, left and total lung volumes and heart volume between 12 and 32 weeks of gestation. METHODS: Fetal lung and heart volumes were measured using three-dimensional (3D) ultrasound in 650 normal singleton pregnancies at 12-32 weeks. The VOCAL (Virtual Organ Computer-aided AnaLysis) technique was used to obtain a sequence of six sections of each lung and the heart around a fixed axis, each after a 30 degrees rotation from the previous one. The rotation axis for the lungs extended from the apex to the upper limit of the diaphragm dome, and the rotation axis for the heart extended from its apex to its connection to the great vessels. The contour of each of these organs was drawn manually in the six different rotation planes to obtain the 3D volume measurement. In 60 cases the fetal lungs and heart volumes were measured by the same sonographer twice and also by a second sonographer once in order to compare the measurements and calculate intra- and interobserver agreement. RESULTS: The total lung volume and heart volume increased with gestation, from respective mean values of 1.6 and 0.6 mL at 12 weeks to 10.9 and 4.3 mL at 20 weeks and 49.3 and 26.6 mL at 32 weeks. The right to left lung volume ratio did not change significantly with gestation (median, 0.7), whereas the heart to total lung volume ratio increased with gestation from about 0.3 at 12 weeks to 0.5 at 32 weeks. In the Bland-Altman plot, the difference between paired measurements by two sonographers was, in 95% of the cases, less than 0.05, 0.5 and 1.9 mL for each lung at 12-13, 19-22 and 29-32 weeks, respectively, and the corresponding values for the heart volumes were 0.04, 0.4 and 2.3 mL. CONCLUSIONS: In normal fetuses the lung and heart volumes increase between 12 and 32 weeks of gestation. The extent to which in pathological pregnancies possible deviations in these measurements from normal prove to be useful in the prediction of outcome remains to be determined. 相似文献
82.
B Sedgmen C McMahon D Cairns R J Benzie R L Woodfield 《Ultrasound in obstetrics & gynecology》2006,27(3):245-251
OBJECTIVE: To explore the impact of timing and type of ultrasound, particularly three-dimensional (3D), exposure on maternal-fetal attachment and maternal health behavior during pregnancy. METHODS: Subjects were 68 women aged 18 years or older expecting their first child who presented for a routine ultrasound scan at around either 12 or 18 weeks' gestation in Nepean Hospital, Western Sydney. Women completed questionnaires assessing maternal-fetal attachment and health behavior, and were then allocated arbitrarily to either two-dimensional (2D) or 3D ultrasound examination. Repeat questionnaires were completed 1 week later. RESULTS: Maternal-fetal attachment increased after both 2D and 3D ultrasound exposure, and the effect was moderated by the timing of exposure, with women receiving their first ultrasound examination at around 12 weeks showing the greatest change. Alcohol consumption was the only behavior to show significant change following ultrasound exposure, with a reduction in the reported average number of drinks per week. There was no significant difference in the pattern of change for 2D compared with 3D ultrasound exposure, and no effect of ultrasound exposure on maternal perception of the fetus. CONCLUSIONS: Ultrasound has a positive impact on maternal-fetal attachment, particularly in the first trimester. 3D ultrasound did not offer enhanced benefits. Associations between ultrasound exposure and alcohol consumption warrant further investigation. Larger samples are needed to clarify the moderating effects of gestational age and type of ultrasound exposure. 相似文献
83.
A. Cagnin M. Kassiou S. R. Meikle R. B. Banati 《Acta neurologica Scandinavica》2006,114(S185):107-114
84.
目的研究渐进性活动训练对膀胱全切、尿流改道术后患者肠功能恢复的影响.方法2003年1月~2005年8月,将138例行膀胱全切、尿流改道术的患者随机分为2组,训练组在常规护理方法的基础上,同时实施渐进性活动训练,对照组采取常规护理方法.结果2组患者小肠梗阻的发生比较,差异有显著意义(P<0.01).结论渐进性活动训练可降低膀胱全切、尿流改道术后患者小肠梗阻的发生. 相似文献
85.
86.
Katharine R. Owen Mollie Donohoe Sian Ellard Andrew T. Hattersley 《Diabetic medicine》2003,20(10):823-827
Background Familial partial lipodystrophy (FPLD) is a monogenic form of diabetes characterised by a dominantly inherited disorder of adipose tissue associated with the loss of subcutaneous fat from the limbs and trunk, with excess fat deposited around the face and neck. The lipodystrophy causes severe insulin resistance, resulting in acanthosis nigricans, diabetes, dyslipidaemia, and increased risk of cardiovascular disease. Preliminary results from animals and man suggest that increasing subcutaneous fat by treatment with thiazolidinediones should improve insulin resistance and the associated features of this syndrome. Case report We report a 24-year-old patient with FPLD caused by a mutation in the LMNA gene (R482W) treated with 12 months of rosiglitazone. Subcutaneous fat increased following rosiglitazone treatment as demonstrated by a 29% generalised increase in skin-fold thickness. Leptin levels increased from 5.8 to 11.2 ng/ml. Compared with treatment on Metformin, there was an increase in insulin sensitivity (HOMA S% 17.2–31.6) but no change in glycaemic control. The lipid profile worsened during the follow-up period. Conclusion This initial case suggests that, for modification of cardiovascular risk factors, there are no clear advantages in treating patients with FPLD with rosiglitazone despite increases in subcutaneous adipose tissue. Larger series will be needed to identify moderate beneficial effects and treatment may be more effective in patients with generalised forms of lipodystrophy. 相似文献
87.
88.
Pancreatic Panniculitis Associated with Allograft Pancreatitis and Rejection in a Simultaneous Pancreas–Kidney Transplant Recipient 总被引:1,自引:0,他引:1
J. L. Pike J. C. Rice R. L. Sanchez E. B. Kelly B. C. Kelly 《American journal of transplantation》2006,6(10):2502-2505
Pancreatic panniculitis is an uncommon condition that can occur in association with pancreatic disease. We present a case of pancreatic panniculitis in a female pancreas-kidney transplant recipient 5 months post-transplant. The patient was on standard immunosuppressive medications and had acute rejection of her renal allograft. The diagnosis of allograft pancreatitis and rejection presenting with pancreatic panniculitis was supported clinically, histopathologically and by laboratory and imaging data. This is the fourth case of pancreatic panniculitis occurring in a transplant recipient and the first in a simultaneous pancreas-kidney transplant recipient. It is also the first case associated with allograft rejection. Clinicians should be aware that pancreatic panniculitis may be a manifestation of underlying allograft pancreatic disease. 相似文献
89.
K. Dahan V. Audard F. Roudot-Thoraval D. Desvaux M. Abtahi H. Mansour M. Kumal P. Lang P. Grimbert 《American journal of transplantation》2006,6(7):1725-1730
The clinical outcome and appropriate management for patients showing 'borderline changes' on allograft biopsy after renal transplantation is still controversial. In an attempt to identify predictive factors of clinical outcome of patients with such lesions, we reviewed the clinical course of 91 patients with borderline changes. Multivariate analysis revealed significant and independent effects of histological stage (i + t < or = or > 2) and time to borderline changes (< or = or > 3 months after transplant) on serum creatinine levels at 1 year from borderline changes episodes (respectively, p = 0.04 and p = 0.02) and only a significant effect of time to borderline changes on serum creatinine levels at 2 years (p = 0.005). Renal function at 1 year and 2 years as 5- and 8-year graft survival were not significantly different in the group of patients treated with antirejection therapy (T group, n = 49) compared with the untreated group (UT group, n = 42). This study strongly suggests that borderline changes with histological score (i + t) > 2 and late episodes of borderline changes should be considered to be of poor prognosis. 相似文献
90.
J. F. Trotter J. Campsen T. Bak M. Wachs L. Forman G. Everson I. Kam 《American journal of transplantation》2006,6(8):1882-1889
The purpose of this study is to determine the role of liver biopsy and outcome of patients undergoing donor evaluation for adult-to-adult right hepatic lobe living donor liver transplantation (LDLT). Records of patients presenting for a comprehensive donor evaluation between 1997 and February 2005 were reviewed. Liver biopsy was performed only in patients with risk factors for abnormal histology. Two hundred and sixty patients underwent a comprehensive donor evaluation and 116 of 260 (45%) were suitable for donation, 14 of 260 (5.4%) did not complete evaluation and 130 of 260 (50%) were rejected. Four patients underwent unsuccessful hepatectomy surgery due to discovery of intraoperative abnormalities. Between 1997 and 2001, the acceptance rate of donor candidates (63%) was higher than 2002-2005 (36%), p < 0.0001. Sixty-six of the 150 eligible patients (44%) fulfilled criteria for liver biopsy and 28 of 66 (42%) had an abnormal finding. Less than half of the patients undergoing donor evaluation were suitable donors and the donor acceptance rate has declined over time. A large proportion of the patients undergoing liver biopsy have abnormal findings. Our evaluation process failed to identify 4 of 103 who had aborted donor surgeries. 相似文献