全文获取类型
收费全文 | 8859篇 |
免费 | 699篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 86篇 |
儿科学 | 246篇 |
妇产科学 | 169篇 |
基础医学 | 1362篇 |
口腔科学 | 171篇 |
临床医学 | 771篇 |
内科学 | 1907篇 |
皮肤病学 | 297篇 |
神经病学 | 856篇 |
特种医学 | 228篇 |
外国民族医学 | 3篇 |
外科学 | 1295篇 |
综合类 | 55篇 |
一般理论 | 7篇 |
预防医学 | 821篇 |
眼科学 | 169篇 |
药学 | 548篇 |
中国医学 | 25篇 |
肿瘤学 | 571篇 |
出版年
2023年 | 91篇 |
2022年 | 159篇 |
2021年 | 294篇 |
2020年 | 202篇 |
2019年 | 279篇 |
2018年 | 301篇 |
2017年 | 221篇 |
2016年 | 248篇 |
2015年 | 267篇 |
2014年 | 340篇 |
2013年 | 437篇 |
2012年 | 606篇 |
2011年 | 640篇 |
2010年 | 355篇 |
2009年 | 319篇 |
2008年 | 474篇 |
2007年 | 444篇 |
2006年 | 491篇 |
2005年 | 450篇 |
2004年 | 375篇 |
2003年 | 347篇 |
2002年 | 303篇 |
2001年 | 178篇 |
2000年 | 150篇 |
1999年 | 140篇 |
1998年 | 66篇 |
1997年 | 61篇 |
1996年 | 64篇 |
1995年 | 56篇 |
1994年 | 62篇 |
1993年 | 52篇 |
1992年 | 145篇 |
1991年 | 121篇 |
1990年 | 81篇 |
1989年 | 70篇 |
1988年 | 68篇 |
1987年 | 60篇 |
1986年 | 74篇 |
1985年 | 68篇 |
1984年 | 47篇 |
1983年 | 35篇 |
1982年 | 34篇 |
1981年 | 24篇 |
1979年 | 18篇 |
1978年 | 31篇 |
1976年 | 22篇 |
1974年 | 20篇 |
1972年 | 17篇 |
1971年 | 17篇 |
1969年 | 22篇 |
排序方式: 共有9587条查询结果,搜索用时 8 毫秒
11.
12.
Fusion of genes encoding Escherichia coli heat-stable enterotoxin and outer membrane protein OmpC. 总被引:2,自引:0,他引:2 下载免费PDF全文
The OmpC outer membrane protein of Escherichia coli was used as a carrier molecule for the nonimmunogenic heat-stable enterotoxin STa. Two fragments of different lengths of the gene encoding STa were fused in vitro to the 3' terminus of the truncated ompC gene. The resulting OmpC-STa hybrid proteins could be detected by L-[35S]cysteine labeling, and they were processed and thus exported. All synthesized hybrid protein remained cell bound and was found by fractionation mainly in the periplasm. Immunoblot analysis showed that the hybrid proteins reacted in vitro both with anti-OmpC and anti-STa antibodies, and immunization of rabbits evoked an antibody response to either of these proteins. 相似文献
13.
Neuropsychologic symptoms in the migraine syndrome 总被引:1,自引:0,他引:1
Twenty patients with complex neuropsychologic symptoms associated with classic migraine were selected from a group of 200 patients with vascular headache. Twenty types of symptoms were found and grouped into six categories (language, visual symptoms, cognitive-dysmnesic symptoms, olfactory-gustatory hallucinations, automatisms, and somatosensory symptoms). Some of the symptoms found have apparently not been reported previously. The importance of the analysis of this complex neuropsychologic set of symptoms and of the possible consequences of complicated, frequent vascular headache is emphasized. 相似文献
14.
J B Fortune J Sanchez L Graca J Haselbarth D H Kuehler J R Wallace W Edge P J Feustel 《The Journal of trauma》1992,33(1):130-7; discussion 137-9
Approximately 25% of all injury victims are in the pediatric age group, and one in four injured children will require a pediatric trauma center. According to the American College of Surgeons as well as many state guidelines, a level I pediatric trauma team should be directed by a pediatric surgeon. In 1986, the pediatric surgeon left our pediatric trauma center, but the center remained open under a cooperative effort by the adult trauma surgeons and pediatric intensivists. We have retrospectively reviewed the charts of all pediatric trauma patients (age less than or equal to 15 years) for the subsequent 4 years to determine the outcome of treatment without a pediatric surgeon. During this period, we treated 303 pediatric patients with multiple or serious single-system injuries. The mean age was 6.9 +/- 0.3 (SEM) years and 66% were boys. Falls were the cause of injury in 31% of the patients, with pedestrian/bicycle, motor vehicle crashes, and penetrating injuries resulting in 26%, 19%, and 3% of the injuries, respectively. The mean ISS was 15.6 +/- 0.8, and 73% of the patients had at least one AIS greater than or equal to 3. Surgical procedures were required in 48% of the patients. There were 27 deaths in this group, most commonly related to head injury (89%). The mean Pediatric Trauma Score of the patients who died was 1.6 +/- 0.8 and no patient with a Pediatric Trauma Score greater than 7 died.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
15.
16.
I Pascual-Castroviejo M C Roche V Martinez Fernndez M Perez-Romero R M Escudero J J Garcia-Peas M Sanchez 《AJNR. American journal of neuroradiology》1994,15(8):1521
PURPOSETo describe the MR findings in eight girls and women with incontinentia pigmenti, from two families. Four had skin lesions and neurologic disease, and four had only skin lesions.METHODSEight patients had physical examination, family history, electroencephalogram and MR examination of the brain. MR was repeated in the two cases with more severe changes several years after the first study.RESULTSMR revealed brain changes only in the four patients who had neurologic disease associated with the cutaneous lesions of incontinentia pigmenti. Abnormalities were located in the cerebral hemisphere contralateral to the most affected side of the body. In two cases, the MR changes were subjacent to the scalp areas where the most severe cutaneous lesions were located in the neonatal period. Hypoplasia of the corpus callosum, probably secondary to atrophy of one or both cerebral hemispheres, and abnormal signal and atrophy of the lateral regions of one of the cerebellar hemispheres also were found in all four cases. Although the changes were seen in both the T1- and T2-weighted images, they were most evident in the latter. The four patients in the fourth stage who had only cutaneous lesions without neurologic problems did not reveal any MR abnormalities.CONCLUSIONSThis study demonstrates MR signal changes and focal atrophy of the cerebrum, cerebellum, and corpus callosum in patients with incontinentia pigmenti and neurologic disorders. The MR images appear normal in patients with incontinentia pigmenti who have no neurologic abnormalities. 相似文献
17.
Lucia Carvalho Monica Lipay Francisco Belfort Ivan Santos Joyce Andrade Alessandra Haddad Flavia Brunstein Lydia Ferreira 《Journal of plastic, reconstructive & aesthetic surgery》2006,59(9):961-968
BACKGROUND: Telomerase activity (TA) is believed to play a role in the regulation of senescence and to limit the number of cell divisions. The deregulation of telomerase appears to contribute to oncogenesis and the formation of immortal cell lines. As a result, it is believed that it could be used as a prognostic marker in melanoma. METHODS: TA was assayed by the polymerase chain reaction PCR-ELISA-based telomeric repeat amplification protocol (TRAP assay). One hundred and eight samples were distributed in four histological groups: 30 samples from primary cutaneous melanomas, 24 from peritumoural skin sites, 28 from benign melanocytic lesions, and 26 from normal skin sites as a control. RESULTS: TA was different among the four tested groups (Kruskall-Wallis test p<0.001), and increasing values of TA were observed progressing from normal skin to benign and then to malignant lesions. Among melanoma samples, there was a significant association between TA and ulceration (p=0.025), TA and vascular invasion (p=0.018) and TA and mitotic rate (p=0.029) (Mann-Whitney test). A linear regression analysis showed significant associations between the increase of TA with Breslow thickness (p=0.004) and the presence of satellites (p=0.002). CONCLUSIONS: We observed that TA had increased from control skin to peritumoural skin, and then to benign melanocytic lesions and finally to melanoma, suggesting tumour progression. TA showed higher values in the presence of some important histopathologic parameters related to poor prognosis in cutaneous melanoma such as ulceration, vascular invasion, satellites, high rates of mitosis, and in thicker tumours. 相似文献
18.
19.
J. Sanchez Burson J. Graña Gil M. Rosales Rodriguez A. Atanes Sandoval C. Alonso Blanco F. Galdo Fernandez 《Clinical rheumatology》1992,11(2):261-264
Summary We have studied the characteristics of arthritis present in 32 patients with Behçet's disease (BD), and how this arthritis is related to the HLA markers class I. 84% of the patients presented arthritis, the most common being monoarthritis as the initial presentation, and oligoarthritis in subsequent episodes. In 63% of the cases, the development was in episodes of acute/subacute arthritis. We found statistically significant association between antigens B-5 and B-51, and the group with BD, with a relative risk of 3.89 and 4.71 respectively. The attempt to relate markers B-5, B-51 and B-27 to the presence of arthritis as well as to its manifestation and further development was not conclusive. 相似文献
20.
Fernandez-Aviles Francisco; Sanchez Pedro L.; On behalf of the GRACIA Group 《European heart journal》2007,28(19):2418
We thank Dr Villata et al. for their thought-provoking comments.Their concern about the suitableness to choose combined endpointsin clinical trials deserves some comment. 相似文献