全文获取类型
收费全文 | 1545篇 |
免费 | 71篇 |
国内免费 | 33篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 62篇 |
妇产科学 | 27篇 |
基础医学 | 127篇 |
口腔科学 | 46篇 |
临床医学 | 150篇 |
内科学 | 379篇 |
皮肤病学 | 111篇 |
神经病学 | 46篇 |
特种医学 | 269篇 |
外科学 | 135篇 |
综合类 | 29篇 |
预防医学 | 82篇 |
眼科学 | 9篇 |
药学 | 62篇 |
中国医学 | 4篇 |
肿瘤学 | 85篇 |
出版年
2021年 | 11篇 |
2019年 | 10篇 |
2018年 | 8篇 |
2017年 | 13篇 |
2016年 | 18篇 |
2015年 | 25篇 |
2014年 | 41篇 |
2013年 | 79篇 |
2012年 | 33篇 |
2011年 | 35篇 |
2010年 | 59篇 |
2009年 | 67篇 |
2008年 | 34篇 |
2007年 | 39篇 |
2006年 | 36篇 |
2005年 | 43篇 |
2004年 | 22篇 |
2003年 | 30篇 |
2002年 | 29篇 |
2001年 | 33篇 |
2000年 | 21篇 |
1999年 | 24篇 |
1998年 | 87篇 |
1997年 | 73篇 |
1996年 | 79篇 |
1995年 | 50篇 |
1994年 | 63篇 |
1993年 | 54篇 |
1992年 | 20篇 |
1991年 | 21篇 |
1990年 | 27篇 |
1989年 | 45篇 |
1988年 | 46篇 |
1987年 | 37篇 |
1986年 | 27篇 |
1985年 | 26篇 |
1984年 | 23篇 |
1983年 | 12篇 |
1982年 | 22篇 |
1981年 | 18篇 |
1980年 | 13篇 |
1979年 | 17篇 |
1978年 | 14篇 |
1977年 | 16篇 |
1976年 | 16篇 |
1975年 | 12篇 |
1973年 | 14篇 |
1972年 | 9篇 |
1971年 | 7篇 |
1957年 | 7篇 |
排序方式: 共有1649条查询结果,搜索用时 31 毫秒
91.
Colostrum protects the newborn from intestinal infection by its content of secretory immunoglobulin A and other immediately acting factors. It may also induce maturation of the child's gastrointestinal immune defences, thus contributing to the protection against diarrhoeal disease later in infancy. To test this hypothesis, a case–control study on breast feeding and diarrhoea was carried out in a periurban community in Guinea–Bissau. The child's age at the start of breast feeding was ascertained soon after birth ( n = 279). Subsequent cases of acute diarrhoea ( n = 66) were identified at 3–monthly examinations, and four concurrent controls were randomly selected among attendants. Three separate estimates of association showed that the cases tended to have started breast feeding later after birth than the diarrhoea–free controls, but no single test was statistically significant. Early breast feeding might have consequences for diarrhoeal morbidity after the neonatal period. 相似文献
92.
Rizzi A Rizzi D Marzola G Regoli D Larsen BD Petersen JS Calo' G 《British journal of pharmacology》2002,137(3):369-374
1 This study reports on the pharmacological characterization of ZP120, a novel ligand of the nociceptin/orphanin FQ (N/OFQ) peptide receptor, NOP. ZP120 is a structure inducing probes modified NOP ligand: Zealand Pharma proprietary SIP technology was used to increase the enzymatic stability and half-life of peptide. 2 In vitro, ZP120 mimicked the inhibitory effects of N/OFQ in the electrically stimulated mouse vas deferens, showing however higher potency (pEC(50) 8.88 vs 7.74), lower maximal effects (E(max) 69+/-5% vs 91+/-2%), and slower onset of action. Like N/OFQ, the effects of ZP120 were not modified by 1 micro M naloxone, but they were antagonized by the NOP receptor selective antagonist J-113397 (pA(2) 7.80 vs ZP120, 7.81 vs N/OFQ). 3 In vivo, ZP120 mimicked the effects of N/OFQ, producing pronociceptive effects in the tail withdrawal assay and decreased locomotor activity after i.c.v., but not after i.v. administration in mice. ZP120 elicited similar maximal effects as N/OFQ, but it was about 10 fold more potent and its effects lasted longer. 4 In conclusion, the novel NOP receptor ligand ZP120 is a highly potent and selective partial agonist of the NOP receptor with prolonged effects in vivo. 相似文献
93.
Effect of low level laser therapy on the repair of bone defects grafted with inorganic bovine bone 总被引:5,自引:0,他引:5
Pinheiro AL Limeira Júnior Fde A Gerbi ME Ramalho LM Marzola C Ponzi EA 《Brazilian dental journal》2003,14(3):177-181
The aim of this study was to assess histologically the effect of LLLT (lambda 830 nm) on the repair of standardized bone defects on the femur of Wistar albinus rats which were grafted with inorganic bovine bone Gen-ox(R). Three randomized groups were studied: group I (control, n=6); group II (Gen-ox, n=9) and group III (Gen-ox + LLLT, n=9). The animals were irradiated every 48 h during 15 days; the first irradiation was performed immediately after the procedure. The animals were irradiated transcutaneuosly at four points around the defect. At each point a dose of 4 J/cm(2) was given (? approximately 0.6 mm, 40 mW) and the total dose per session was 16 J/cm(2). The animals were killed by an overdose of general anesthetic 15, 21 and 30 days after surgery. The specimens were routinely processed by embedding in paraffin, serially cut and stained with H&E and Picrosirius and analyzed under light microscopy. The results showed evidence of a more advanced repair in the irradiated group when compared to the non-irradiated groups. The repair of the irradiated group was characterized by both increased bone formation and amount of collagen fibers around the graft within the cavity from the 15th day after surgery, also considering the osteoconductive capacity of the Gen-ox. We conclude that LLLT had a positive effect on the repair of bone defects implanted with inorganic bovine bone. 相似文献
94.
95.
96.
97.
RM Subramaniam J Sherriff K Holmes MC Chan B Shadbolt 《Journal of Medical Imaging and Radiation Oncology》2006,50(5):442-446
This study was conducted to establish clinicians’ perspectives of a set of radiology curriculum topics for medical student teaching, which were held to be important by radiologists. A questionnaire was sent to clinicians in all specialties. Forty‐six clinicians (51.1%) out of 90 returned the questionnaires. All curriculum topics were scored above an average of 4 (agree). The five highest ranking curriculum topics in order of importance were: developing a system for viewing chest radiographs (5.59), developing a system for viewing abdominal radiographs (5.56), developing a system for viewing bone and joint radiographs (5.33), distinguishing normal structures from abnormal in chest and abdominal radiographs (5.33) and identifying gross bone or joint abnormalities in skeletal radiographs (5.22). Correlative analysis between speciality groups showed surgical and medical specialities were significantly different in their responses of two learning outcomes: basic knowledge about the contrast media benefits and risks (P= 0.01) and ability to select the most appropriate and the most cost‐effective methods of radiological investigations for clinical situations (P= 0.03). Acute specialities were not significantly different from the other two groups for these two learning outcomes. There was no statistically significant difference for other learning outcomes between the three speciality groups. 相似文献
98.
99.
Aberrant Notch signalling has been observed in several human cancers, including acute T-cell lymphoblastic leukaemia and cervical cancer, and is strongly implicated in tumourigenesis. Unregulated Notch signalling in the mouse mammary gland leads to tumour formation. These results raise the possibility that Notch signalling might play a role in human breast cancer. There are currently few reports that address this question directly and this appears to be an area worthy of further investigation. 相似文献
100.
Pansini GC Lanzara S Feo CV Zamboni P Liboni A Ambrosio MR Marzola A Feggi L 《Annali italiani di chirurgia》2001,72(4):413-21; discussion 422
The aim of this study was to review our experience with endocrine tumours of the gastrointestinal tract and pancreas (ETGIP). Between February 1991 and March 2000, sixteen patients with ETGIP were operated on at our institution. Of these patients we reviewed preoperative symptoms, diagnostic techniques (ultrasound, CT, MRI, radiolabelled octreotide scintigraphy, angiography, immunohistochemical study), treatment (surgical operation, neoadjuvant and adjuvant chemotherapy, and radiometabolic therapy) and survival. Nine patients (56%) had a carcinoid tumour, three (19%) an unspecified endocrine tumour, and four (25%) an endocrine tumour associated with a non-endocrine neoplasm. Only five patients (31%) had a preoperative diagnosis of endocrine tumour. Eight patients (50%) had metastatic disease at the time of the operation. All patients without preoperative metastasis (eight patients, 50%) are still alive without recurrent disease, with a mean postoperative survival of 36 months (12-60 months). Of eight patients with metastatic disease, six (75%) died after a mean of 20.5 months (3-60 months) and two (25%) are still alive with the disease after 3 and 6 months, respectively. These data show that presence of metastasis strongly influence survival. Furthermore, survival of patients with metastatic disease seems to be longer as compared to other gastrointestinal tract malignancies. ETGIP are more common and aggressive than previously believed and, therefore, early diagnosis is crucial for cure. Nowadays, however, new diagnostic tools such as radiolabelled octreotide scintigraphy are available for diagnosis and postoperative follow-up. The optimal treatment for ETGIP is a multimodal approach with surgical operation, chemoradiation, radiometabolic, and genetic therapies. 相似文献