全文获取类型
收费全文 | 1641篇 |
免费 | 191篇 |
国内免费 | 28篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 214篇 |
妇产科学 | 28篇 |
基础医学 | 212篇 |
口腔科学 | 90篇 |
临床医学 | 167篇 |
内科学 | 310篇 |
皮肤病学 | 49篇 |
神经病学 | 30篇 |
特种医学 | 173篇 |
外科学 | 235篇 |
综合类 | 53篇 |
预防医学 | 100篇 |
眼科学 | 40篇 |
药学 | 57篇 |
中国医学 | 2篇 |
肿瘤学 | 93篇 |
出版年
2023年 | 14篇 |
2022年 | 14篇 |
2021年 | 14篇 |
2020年 | 16篇 |
2019年 | 8篇 |
2018年 | 48篇 |
2017年 | 47篇 |
2016年 | 46篇 |
2015年 | 62篇 |
2014年 | 78篇 |
2013年 | 110篇 |
2012年 | 61篇 |
2011年 | 46篇 |
2010年 | 87篇 |
2009年 | 92篇 |
2008年 | 37篇 |
2007年 | 50篇 |
2006年 | 51篇 |
2005年 | 29篇 |
2004年 | 35篇 |
2003年 | 18篇 |
2002年 | 26篇 |
2001年 | 18篇 |
2000年 | 12篇 |
1999年 | 28篇 |
1998年 | 102篇 |
1997年 | 89篇 |
1996年 | 98篇 |
1995年 | 64篇 |
1994年 | 76篇 |
1993年 | 40篇 |
1992年 | 17篇 |
1991年 | 23篇 |
1990年 | 14篇 |
1989年 | 31篇 |
1988年 | 29篇 |
1987年 | 29篇 |
1986年 | 26篇 |
1985年 | 30篇 |
1984年 | 17篇 |
1983年 | 14篇 |
1982年 | 22篇 |
1981年 | 18篇 |
1980年 | 16篇 |
1979年 | 7篇 |
1978年 | 9篇 |
1977年 | 10篇 |
1976年 | 15篇 |
1975年 | 9篇 |
1966年 | 2篇 |
排序方式: 共有1860条查询结果,搜索用时 15 毫秒
991.
AM Kazi A Murtaza S Khoja AK Zaidi SA Ali 《Bulletin of the World Health Organization》2014,92(3):220-225
Problem
Polio remains endemic in many areas of Pakistan, including large urban centres such as Karachi.Approach
During each of seven supplementary immunization activities against polio in Karachi, mobile phone numbers of the caregivers of a random sample of eligible children were obtained. A computer-based system was developed to send two questions – as short message service (SMS) texts – automatically to each number after the immunization activity: “Did the vaccinator visit your house?” and “Did the enrolled child in your household receive oral polio vaccine?” Persistent non-responders were phoned directly by an investigator.Local setting
A cluster sampling technique was used to select representative samples of the caregivers of young children in Karachi in general and of such caregivers in three of the six “high-risk” districts of the city where polio cases were detected in 2011.Relevant changes
In most of the supplementary immunization activities investigated, vaccine coverages estimated using the SMS system were very similar to those estimated by interviewing by phone those caregivers who never responded to the SMS messages. In the high-risk districts investigated, coverages estimated using the SMS system were also similar to those recorded – using lot quality assurance sampling – by the World Health Organization.Lessons learnt
For the monitoring of coverage in supplementary immunization activities, automated SMS-based systems appear to be an attractive and relatively inexpensive option. Further research is needed to determine if coverage data collected by SMS-based systems provide estimates that are sufficiently accurate. Such systems may be useful in other large-scale immunization campaigns. 相似文献992.
Stefańska AM Péault B Mullins JJ 《Pflügers Archiv : European journal of physiology》2013,465(6):767-773
Pericytes have become a hot topic in renal biology. They play a critical physiological role in vessel development, maintenance and remodelling through active communication with their vascular partners—endothelial cells—and modulation of extracellular matrix proteins. Multiple functions for renal pericytes have been described; specialised perivascular populations participate in glomerular filtration, regulate medullary blood flow and contribute to kidney fibrosis by differentiation into collagen-generating myofibroblasts. Interestingly, the origin of renin-producing cells of the juxtaglomerular region is attributed to the perivascular cell lineage; we have observed the coincidence of renin and pericyte marker expression during human kidney development. Finally, pericytes have been shown to share features with mesenchymal stem cells, which places them as potential renal progenitor cell candidates. Since renal diseases are often associated with microvascular complications, renal pericytes may emerge as new targets for the treatment of kidney disease. 相似文献
993.
Peter AM Everts Christine Brown Mahoney Johannes JML Hoffmann Jacques PAM Schönberger Henk AM Box André van Zundert 《Growth factors (Chur, Switzerland)》2013,31(3):165-171
Background: In this study, three commercial systems for the preparation of platelet-rich plasma (PRP) were compared and platelet growth factors release was measured.Methods: Ten healthy volunteers donated whole blood that was fractionated by a blood cell separator, and a table-top centrifuge to prepare PRP. Furthermore, an autologous growth factor filter was used to concentrate PRP fractionated by the blood cell separator. PRP was subsequently activated with autologously produced thrombin to degranulate the platelets to measure platelet-derived growth factor-AB (PDGF-AB), transforming growth factor-beta (TGF-β), insulin-like growth factor-1 (IGF-1), and vascular endothelial growth factor (VEGF).Results: PRP contained significantly higher platelet counts compared with baseline values (p < 0.001). PDGF-AB concentrations were increased more than 18-fold in the platelet gel supernatant when the cell-separator and GPS were used, whereas only a 3-fold increase was seen with the AGF.Conclusion: The three PRP devices enable the preparation of PRP for the release of high concentrations of platelet growth factor, but showed different harvesting capacities for the collection of concentrated platelets. The administration of thrombin for PRP activation resulted in the release of high concentrations of PDGF-AB and TGF-β but only when PRP had not been activated during the preparation process in vitro. 相似文献
994.
AM Harris R Lucey S Deshpande C Muench B Weber KS Wynne 《Annals of the Royal College of Surgeons of England》2006,88(3):269
The case is described of a patient presenting with signs and symptoms of a large bowel obstruction with perforation, who at laparotomy was found to have caecal volvulus but no obvious cause for the air under the diaphragm. On dissection of the lesser sac, he was found to have an oesophageal perforation secondary to vomiting caused by the volvulus. This was repaired over a t-tube and despite delayed presentation, he made a full recovery. This cause of Boerhaave's syndrome has not previously been described, and underlines the need for careful search for the cause of air under the diaphragm when the laparotomy findings do not reveal an obvious perforation. 相似文献
995.
996.
997.
998.
999.
1000.