全文获取类型
收费全文 | 329篇 |
免费 | 15篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 28篇 |
妇产科学 | 4篇 |
基础医学 | 34篇 |
口腔科学 | 4篇 |
临床医学 | 38篇 |
内科学 | 91篇 |
皮肤病学 | 11篇 |
神经病学 | 6篇 |
特种医学 | 58篇 |
外科学 | 27篇 |
综合类 | 20篇 |
预防医学 | 12篇 |
眼科学 | 4篇 |
药学 | 10篇 |
肿瘤学 | 15篇 |
出版年
2023年 | 4篇 |
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 4篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2015年 | 7篇 |
2014年 | 7篇 |
2013年 | 12篇 |
2012年 | 6篇 |
2011年 | 8篇 |
2010年 | 13篇 |
2009年 | 18篇 |
2008年 | 11篇 |
2007年 | 27篇 |
2006年 | 8篇 |
2005年 | 8篇 |
2004年 | 4篇 |
2003年 | 4篇 |
2002年 | 4篇 |
2001年 | 11篇 |
2000年 | 5篇 |
1999年 | 6篇 |
1998年 | 11篇 |
1997年 | 13篇 |
1996年 | 19篇 |
1995年 | 8篇 |
1994年 | 18篇 |
1993年 | 12篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 13篇 |
1988年 | 5篇 |
1987年 | 10篇 |
1986年 | 14篇 |
1985年 | 10篇 |
1984年 | 7篇 |
1983年 | 6篇 |
1982年 | 7篇 |
1981年 | 9篇 |
1980年 | 7篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 6篇 |
1975年 | 3篇 |
1973年 | 1篇 |
排序方式: 共有363条查询结果,搜索用时 15 毫秒
101.
102.
HENRIK VERDER KIRSTEN STHR JOHANSEN KRSTEN ENGBK 《Acta paediatrica (Oslo, Norway : 1992)》1973,62(1):59-65
Manometrical measurements of reflex responses in the internal anal sphincter were made in 93 patients. In normal controls, a relaxation was obtained within the internal sphincter after distension of the rectum. Patients suffering from Hirschsprung's disease showed either a contraction in the muscle or an absence of sphincteric response. In 17 cases, where the diagnosis of Hirschsprung's disease was established by conventional means, the diagnosis was confirmed by anal tonometry in 13 cases and disproved by this method in 4 cases. The subsequent clinical course and histological findings have verified the diagnosis obtained by tonometry. In one patient it was not possible to make the diagnosis by means of the usual methods, anal tonometry showed Hirschsprung's disease and this was subsequently confirmed by biopsy. 相似文献
103.
AJ Blethyn K Verrier Jones R Newcombe GM Roberts HR Jenkins 《Archives of disease in childhood》1995,73(6):532-533
A scoring system for faecal loading was constructed by two experienced observers using the abdominal radiographs of 20 children. Four other observers independently graded the radiographs using this system and there was a high degree of agreement between all six observers (p < 0.001), suggesting that radiological assessment of constipation can be standardised. 相似文献
104.
The necdin gene is deleted in Prader-Willi syndrome and is imprinted in human and mouse 总被引:9,自引:5,他引:9
Human chromosome 15q11-q13 contains genes that are imprinted and expressed
from only one parental allele. Prader-Willi syndrome (PWS) is due to the
loss of expression of one or more paternally expressed genes on proximal
human chromosome 15q, most often by deletion or maternal uniparental
disomy. Several candidate genes and a putative imprinting centre have been
identified in the deletion region. We report that the human necdin-encoding
gene (NDN) is within the centromeric portion of the PWS deletion region,
between the two imprinted genes ZNF127 and SNRPN. Murine necdin is a
nuclear protein expressed exclusively in differentiated neurons in the
brain. Necdin is postulated to govern the permanent arrest of cell growth
of post-mitotic neurons during murine nervous system development. We have
localized the mouse locus Ndn encoding necdin to chromosome 7 in a region
of conserved synteny with human chromosome 15q11-q13, by genetic mapping in
an interspecific backcross panel. Furthermore, we demonstrate that
expression of Ndn is limited to the paternal allele in RNA from newborn
mouse brain. Expression of NDN is detected in many human tissues, with
highest levels of expression in brain and placenta. NDN is expressed
exclusively from the paternally inherited allele in human fibroblasts. Loss
of necdin gene expression may contribute to the disorder of brain
development in individuals with PWS.
相似文献
105.
Supratentorial ependymoma: CT appearance 总被引:5,自引:0,他引:5
Armington WG; Osborn AG; Cubberley DA; Harnsberger HR; Boyer R; Naidich TP; Sherry RG 《Radiology》1985,157(2):367-372
The computed tomographic appearances of 22 biopsy-proved supratentorial ependymomas were analyzed. Supratentorial ependymomas were usually intraparenchymal, larger than 4 cm, and cystic. Contrast enhancement was moderate to intense, with homogeneous or ring-enhancement patterns commonly seen. Intratumoral calcification was present in one-third of the cases, while hydrocephalus and peritumoral edema were seen in 50%. Intratumoral hemorrhage was not a characteristic of the lesion. In contrast to cellular ependymomas, malignant ependymomas and ependymoblastomas demonstrate higher attenuation prior to administration of contrast material, more intense enhancement, lower frequency of calcification within the tumor, and less distinct margination. 相似文献
106.
ST Kempley S Bennett BG Loftus D Cooper HR Gamsu 《Acta paediatrica (Oslo, Norway : 1992)》1993,82(2):173-176
In order to determine if umbilical arterial Catheter position affects the incidence of necrotizing enterocolitis, clinical outcome was analysed in 308 infants whose umbilical arterial catheter had been randomly allocated to a high ( n =162) or a low ( n =146) position. Necrotizing enterocolitis was classified as suspected or confirmed; all renal, lower limb and local catheter complications were also recorded. High umbilical arterial catheters were in place for longer than low catheters, provided more samples and were removed as an emergency less often. Lower limb blanching and cyanosis were more common with low catheters. Eleven cases of confirmed necrotizing enterocolitis occurred in the "high" group and nine in the "low" group. One case of fatal aortic thrombosis was encountered in the high group. Positioning umbilical arterial catheters in a high position allowed longer functional use and did not increase the incidence of necrotizing cnterocolitis. 相似文献
107.
F Rasmussen HR Lie JH Hagelsteen J Lagergren M-C Börjeson B Lagerkvist L Köhler 《Acta paediatrica (Oslo, Norway : 1992)》1993,82(3):276-280
The differences between parents' assessments of their child's handicap and professionals' assessment of disabilities were studied in 486 Nordic children with myelomeningocele aged 4–18 years. Although disability and handicap are conceptually different, agreement between the parents' assessments of the handicap and the degree of disability according to Lorber's classification was found in 51% of cases. The parents' assessments showed close agreement with overall disability according to Lagergren's method in 45% of cases. The factors most strongly associated with parental assessment of the handicap were the child's motor disability, intellectual functioning, faecal and urinary incontinence and the parents' inclination to feel inadequate with respect to the child's needs. Data from professional assessment of disabilities alone are of limited value in understanding the impact of disabilities on the daily life of a child. 相似文献
108.
Ravi Babu Kalahasthi HR Rajmohan BK Rajan Karuna Kumar M 《Journal of occupational medicine and toxicology (London, England)》2007,2(1):5-7
Objective
The present study was carried out to determine the effect of cadmium exposure on Urinary N-acetyl-beta -D-glucosaminidase and its isoenzymes A and B in workers exposed at cadmium plating. 相似文献109.
TGF-β2对树突状细胞表型和功能的影响 总被引:3,自引:1,他引:2
目的: 研究转化生长因子-β2 (TGF-β2)对树突状细胞(dendritic cells, DC)表型和功能的影响. 方法: 体外培养骨髓来源的DC(BMDC)及TGF-β2诱导的DC(TGFβ2-DC). 采用双色免疫荧光化学染色或流式细胞仪(FCM)分析DC的细胞表型. 分离纯化脾脏来源的同种异体T细胞和CD4+ T细胞. 用BMDC及TGFβ2-DC刺激T细胞增殖,并用混合淋巴细胞反应(MLR)测定其能力. 在CD4+ T细胞与BMDC或TGFβ2-DC共培养5 d后,用FCM检测CD4+ T细胞表型的变化. 结果: BMDC表现为CD11c, CD86, MHC class II+和CD8а-的髓系DC. TGF-β2的诱导抑制了DC表面协同刺激分子、MHC classII的表达(P<0.01),并抑制其刺激同种异体T细胞增殖的能力. 与BMDC诱导的CD4+ T细胞相比,TGFβ2-DC诱导的CD4+ T细胞CD152(细胞毒T淋巴细胞相关分子4, CTLA-4)表达上升(P<0.01). 结论: TGF-β2的诱导促使DC表面协同刺激因子表达下降,T细胞合成CTLA-4增加,T细胞的活化和增殖受到明显抑制. 相似文献
110.
HR Naderi M Tagliamonte ML Tornesello M Ciccozzi G Rezza R Farid FM Buonaguro L Buonaguro 《Infectious agents and cancer》2006,1(1):4-5
Genetic and phylogenetic information on the HIV-1 epidemic in Middle-East Countries, and in particular in Iran, are extremely
limited. By March 2004, the Iranian Ministry of Health officially reported a cumulative number of 6'532 HIV positive individuals
and 214 AIDS cases in the Iranian HIV-1 epidemic. The intra-venous drug users (IDUs) represent the group at highest risk for
HIV-1 infection in Iran, accounting for almost 63% of all HIV-infected population. In this regards, a molecular phylogenetic
study has been performed on a sentinel cohort of HIV-1 seropositive IDUs enrolled at the end of 2005 at the University of
Mashhad, the largest city North East of Tehran. The study has been performed on both gag and env subgenomic regions amplified by Polymerase Chain Reaction (PCR) from peripheral blood mononuclear cells (PBMCs) and characterized
by direct DNA sequence analysis. The results reported here show that the HIV-1 subtype A is circulating in this IDUs sentinel
cohort. Moreover, the single phylogenetic cluster as well as the intra-group low nucleotide divergence is indicative of a recent outbreak. Unexpectedly, the Iranian samples appear to be phylogenetically
derived from African Sub-Saharan subtype A viruses, raising stirring speculations on HIV-1 introduction into the IDUs epidemic
in Mashhad. This sentinel study could represent the starting point for a wider molecular survey of the HIV-1 epidemics in
Iran to evaluate in detail the distribution of genetic subtypes and possible natural drug-resistant variants, which are extremely
helpful information to design diagnostic and therapeutic strategies. 相似文献