全文获取类型
收费全文 | 11496篇 |
免费 | 802篇 |
国内免费 | 50篇 |
专业分类
耳鼻咽喉 | 116篇 |
儿科学 | 350篇 |
妇产科学 | 276篇 |
基础医学 | 1340篇 |
口腔科学 | 300篇 |
临床医学 | 1365篇 |
内科学 | 2256篇 |
皮肤病学 | 148篇 |
神经病学 | 678篇 |
特种医学 | 327篇 |
外科学 | 1506篇 |
综合类 | 210篇 |
一般理论 | 5篇 |
预防医学 | 981篇 |
眼科学 | 166篇 |
药学 | 895篇 |
中国医学 | 23篇 |
肿瘤学 | 1406篇 |
出版年
2023年 | 59篇 |
2022年 | 104篇 |
2021年 | 248篇 |
2020年 | 168篇 |
2019年 | 222篇 |
2018年 | 279篇 |
2017年 | 207篇 |
2016年 | 221篇 |
2015年 | 256篇 |
2014年 | 372篇 |
2013年 | 551篇 |
2012年 | 729篇 |
2011年 | 754篇 |
2010年 | 458篇 |
2009年 | 359篇 |
2008年 | 684篇 |
2007年 | 727篇 |
2006年 | 716篇 |
2005年 | 629篇 |
2004年 | 597篇 |
2003年 | 579篇 |
2002年 | 530篇 |
2001年 | 321篇 |
2000年 | 269篇 |
1999年 | 233篇 |
1998年 | 141篇 |
1997年 | 117篇 |
1996年 | 112篇 |
1995年 | 99篇 |
1994年 | 77篇 |
1993年 | 78篇 |
1992年 | 153篇 |
1991年 | 121篇 |
1990年 | 135篇 |
1989年 | 113篇 |
1988年 | 100篇 |
1987年 | 93篇 |
1986年 | 73篇 |
1985年 | 75篇 |
1984年 | 67篇 |
1983年 | 66篇 |
1982年 | 43篇 |
1981年 | 40篇 |
1980年 | 38篇 |
1979年 | 44篇 |
1978年 | 36篇 |
1977年 | 27篇 |
1975年 | 26篇 |
1974年 | 30篇 |
1971年 | 20篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
Ngai-Yin Chan Chi-Chung Choy Ho-Chuen Yuen Hoi-Fan Chow Ho-Fai Fong 《The Canadian journal of cardiology》2019,35(4):396-404
Background
Persistent iatrogenic atrial septal defect (iASD) is a common but poorly characterized complication after cryoballoon (CB) pulmonary vein isolation (PVI) procedures. We therefore investigate its prevalence, evolution, risk factors, and clinical outcomes in a prospective longitudinal study.Methods
A total of 108 patients (41 women, mean age 57 ± 11.3) underwent CB PVI for AF. Serial transesophageal echocardiography (TEE) was performed 9 months and then annually until 6 years after the procedure to study the characteristics of persistent iASD.Results
Persistent iASD occurred in 33 (30.6%) patients 9 months after CB PVI. Spontaneous closure of iASD was found in 6 (22.2%) and 3 (15.8%) patients 2 and 3 years after the procedures, respectively. No spontaneous closure was observed on 4, 5, and 6-year TEE follow-up. The projected long-term persistence rate of iASD after CB PVI was therefore 20% (30.6% × 0.778 × 0.842). Using multivariate logistic regression, a higher number of cryoapplications (≥ 2 minutes) was the only independent predictor of persistent iASD 9 months after CB PVI (odds ratio [OR] 1.207; 95% confidence interval [CI], 1.033-1.411, P = 0.018). Two (1.9%) patients with significantly larger iASD size than the others (long diameter 12.6 ± 0.8 vs 3.7 ± 1.5 mm, P < 0.001; short diameter 10.9 ± 0.2 vs 3 ± 1.1 mm, P < 0.001) required percutaneous closure because of exertional dyspnea and right ventricular enlargement. Over 129.7 patient-years follow-up, during which iASD persisted, there was no occurrence of neurologic events.Conclusions
Approximately one fifth of patients undergoing CB PVI will have permanently persistent iASD. Patients with defect sizes of greater than 10 mm may need percutaneous closure due to significant left-to-right shunting. 相似文献2.
3.
Transcapillary fluid balance consequences of missing initial lymphatics studied in a mouse model of primary lymphoedema 总被引:1,自引:0,他引:1
Tine V. Karlsen Marika J. Karkkainen Kari Alitalo Helge Wiig 《The Journal of physiology》2006,574(2):583-596
To investigate the phenotypic consequences of a deranged lymphangiogenesis in relation to tissue fluid accumulation and the possible role of inflammation in the pathogenesis of lymphoedema, we measured determinants of transcapillary fluid filtration and inflammatory mediators in the interstitial fluid in genetically engineered Chy mice, a model for primary congenital lymphoedema (Milroy's disease). Although initial lymphatics were not present in dermis in any of the areas studied (fore paw, hind paw, thigh and back skin) interstitial fluid pressure ( P if ), measured with micropipettes, and tissue fluid volumes were significantly increased only in the areas with visible swelling – the fore and hind paw, whereas interstitial colloid osmotic pressure (COPif ) was increased in all the skin areas examined. A volume load of 15% of body weight resulted in a more pronounced increase in P if as well as a four-fold increase in interstitial fluid volume in Chy relative to wild-type (wt) mice, showing the quantitative importance of lymphatics for fluid homeostasis during acute perturbations. A similar level of proinflammatory markers in interstitial fluid in early established lymphoedema (3–4 months) in Chy and wt suggests that inflammation does not have a major pathogenetic role for the development of lymphoedema, whereas a reduced level of the immunomodulatory cytokine interleukin (IL)-4 may result in a reduced immunological defence ability and thus lead to the increase in inflammatory cytokines IL-2 and IL-6 observed at a later stage (11–13 months). Our data suggest that primary lymphoedema results in a high interstitial fluid protein concentration that does not induce an interstitial inflammatory reaction per se , and furthermore shows the paramount importance of the initial lymphatics in tissue fluid homeostasis, especially during perturbations of transcapillary fluid balance. 相似文献
4.
Kari Hemminki Xinjun Li 《Journal of occupational and environmental medicine / American College of Occupational and Environmental Medicine》2003,45(4):456-461
Epidemiologic data on pleural mesothelioma are scarce on regional and occupational time trends, which would monitor the effects of changes in exposure to asbestos. We aim to characterize time trends, regional, socioeconomic, and occupational risk factors for pleural mesothelioma in Sweden in the years from 1961 to 1998. The Swedish Family-Cancer Database was used to identify patients with pleural mesothelioma. Age-standardized incidence rates and standardized incidence ratio (SIR) were calculated for the population in the Database. A total of 1298 male and 233 female pleural mesotheliomas were retrieved. Age-standardized incidence of the disease was highest, and the trend increased in residents of large industrial and shipbuilding cities. In the last follow-up period, the male rate exceeded the female rate about 10-fold. Among male socioeconomic groups, manual workers showed the highest and ever-increasing SIR. No female socioeconomic group was at risk. For men, plumbers and seamen had the highest risk of 4.56 and 2.83, respectively, but the risks appeared to be decreasing for plumbers, whereas no clear trend was noted for seamen, probably because of indirect expose in ships. Farmers showed an SIR of 0.28, indicating that the population at large was at four times higher risk than farmers. The SIRs of many academic/college-educated groups were two to six times higher than those of farmers, suggesting indirect exposure to asbestos in these groups. 相似文献
5.
The effect of zinc deficiency on intestinal absorption of cholesterol was investigated in adult male rats fed 3.6 ppm of dietary zinc (ZD) and compared with pair-fed (PF) and ad-libitum (CT) controls fed 30.6 ppm of zinc for 10 to 12 wk. The intestinal absorption of cholesterol was measured by collecting the mesenteric lymph at hourly intervals for 8 h after infusing a dose of [14C]cholesterol in a lipid emulsion through an indwelling duodenal catheter. Data on the hourly lymphatic output of [14C]cholesterol showed that the absorption of [14C]cholesterol plateaued at 4 h postdosing in all groups. The rate of the appearance of [14C]cholesterol in the mesenteric lymph significantly decreased in ZD rats at 5 h and thereafter. The cumulative absorption of [14C]cholesterol by ZD rats for the 8-h period was 4.4 +/- 1.0% of the dose, compared with 11.8 +/- 1.1% by PF and 10.7 +/- 1.4% by CT rats. There were no differences in percent distribution of esterified [14C]cholesterol among the three groups. Also, no significant change in mucosal cholesterol esterase activity was observed due to zinc deficiency. The present data and previous findings taken together suggest that the primary mechanism responsible for the impaired absorption of cholesterol may be associated with defective formation of chylomicrons in the intestinal mucosa. 相似文献
6.
7.
Eric Y. T. Chan Daniel K. Ng Chung-hong Chan Ka-li Kwok Pok-yu Chow Josephine M. Cheung Suk-yu Leung 《Sleep & breathing》2009,13(1):59-63
Background and objective The purpose of this study is to assess whether Chinese children with high apnea–hypopnea index (AHI) are sleepier by a modified Epworth Sleepiness Scale (ESS).
Materials and methods Records were retrospectively reviewed. We included children who were between 3 and 12 years old, admitted for overnight polysomnogram
because of suspected obstructive sleep apnea syndrome (OSAS). A modified ESS was used to assess excessive daytime sleepiness
(EDS) of the children.
Results One hundred ninety-two Chinese children were included. Children with high AHI, defined as AHI > 5.0, were sleepier than children with AHI less than or equal
to 5. After adjustment by age, gender, and obesity, children with high AHI remained significantly sleepier. Modified ESS was
significantly correlated with AHI (rho = 0.124, 95% CI = 0.004–0.281). Modified ESS score of >8 was the best cutoff point
with the sensitivity and specificity of 0.29 and 0.91, respectively. The odds ratio of children with modified ESS > 10 having
high AHI was 4.231 (95%CI = 1.248 to 14.338) and children with modified ESS > 8 had the highest odds ratio, 4.295(95%CI = 1.66
to 11.1), of having high AHI.
Conclusion
Chinese children with high AHI appear to be sleepier than children with low AHI. Children with suspected OSAS and high modified ESS,
i.e., ESS > 8, had significantly higher odds ratio of having high AHI. Increased sleepiness is a specific but not a sensitive
symptom in snoring children with high AHI. Screening for EDS in snoring children may help us identify those with high AHI
and prioritize the management of those children.
All authors worked and the study was carried out in Kwong Wah Hospital in Hong Kong. There was no conflict of interest and
no specific source of funding for the study. 相似文献
8.
9.
10.
Transabdominal sacrocolpopexy has been shown, in multiple long-term studies of its success and durability, to be the definitive
treatment option for post-hysterectomy vaginal vault prolapse. It is, however, associated with greater morbidity than vaginal
repair. We describe a minimally invasive technique for vaginal vault prolapse repair and present our experience with a minimum
of one-year follow-up. The surgical technique involves five laparoscopic ports—three for the da Vinci robot and two for the
assistant. After appropriate dissection a polypropylene mesh is attached to the sacral promontory and to the vaginal apex
by use of Gore-Tex sutures. The mesh material is then covered by the peritoneum. Patient analysis focused on complications,
urinary continence, patient satisfaction, and morbidity, with a minimum of 12 months follow-up. Forty-two patients with post-hysterectomy
vaginal vault prolapse underwent robot-assisted laparoscopic sacrocolpopexy at our institute and 35 have a minimum of 12 months
follow-up, with a mean follow-up of 36 months (range 12–48) in the group. Mean age was 67 (47–83) years and mean operating
time was 3.1 (2.15–4.75) h for the entire cohort. All but one patient were discharged home on postoperative day one; one patient
left on postoperative day two. One developed recurrent grade three rectocele, one had recurrent vault prolapse, and two suffered
from vaginal extrusion of mesh. All patients were satisfied with their outcome. The robot-assisted laparoscopic sacrocolpopexy
is a minimally invasive technique for vaginal vault prolapse repair, combining the advantages of open sacrocolpopexy with
the reduced morbidity of laparoscopy. We observed reduced hospital stay, low occurrence of complications, and high patient
satisfaction, with a minimum of 1-year follow-up. Most importantly, the long-term results of the robotic repair are similar
to those of open repair, but with significantly less morbidity. 相似文献