首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   221篇
  免费   12篇
耳鼻咽喉   1篇
儿科学   9篇
妇产科学   13篇
基础医学   30篇
口腔科学   3篇
临床医学   14篇
内科学   49篇
皮肤病学   2篇
神经病学   11篇
特种医学   10篇
外科学   18篇
综合类   3篇
一般理论   1篇
预防医学   10篇
眼科学   1篇
药学   4篇
肿瘤学   54篇
  2022年   2篇
  2020年   2篇
  2016年   3篇
  2015年   5篇
  2014年   3篇
  2013年   4篇
  2012年   11篇
  2011年   11篇
  2010年   4篇
  2009年   5篇
  2008年   19篇
  2007年   13篇
  2006年   22篇
  2005年   16篇
  2004年   12篇
  2003年   11篇
  2002年   13篇
  2001年   5篇
  2000年   3篇
  1999年   4篇
  1998年   2篇
  1997年   2篇
  1995年   1篇
  1994年   4篇
  1993年   2篇
  1992年   3篇
  1990年   2篇
  1989年   1篇
  1988年   2篇
  1987年   10篇
  1986年   4篇
  1985年   3篇
  1984年   8篇
  1983年   1篇
  1982年   1篇
  1981年   1篇
  1979年   1篇
  1977年   1篇
  1976年   4篇
  1974年   3篇
  1973年   1篇
  1972年   2篇
  1970年   3篇
  1968年   1篇
  1967年   2篇
排序方式: 共有233条查询结果,搜索用时 0 毫秒
51.
A case of mucinous cystadenocarcinoma of the appendix is presented. The clinical feature is a painful syndrome of the right iliac fossa. In our observation, the diagnosis was not allowed by preoperative imaging. Appendectomy was initially performed and completed by right hemicolectomy and lymphadenectomy after histological diagnosis of the appendicular malignant tumour was forwarded. The prognosis of this tumour is generally excellent providing early diagnosis and wide enough surgery.  相似文献   
52.
The ion pair concept was applied for the assessment of lipophilicity of cefepime and cefpirome. Octanol-water distribution coefficients were determined in presence of different concentrations [X-] of sodium octanesulphonate. The log Dx values within the linear part of the log Dx/[X-] relationships were extrapolated to log Do values corresponding to the partitioning in absence of the counter ion. Measurements were feasible at pH values close to the isoelectric points of the acidic and basic functions. In that pH range the conduction of the experiments in presence of the hydrophobic counter anion facilitated the partitioning of the two cephalosporins to octanol, circumventing the problems arising from their high hydrophilicity. This procedure could not be applied at lower pH, possibly due to a further drastic decrease in the 'intrinsic' lipophilicity or to reduced ion pairing potential of octanesulphonate, and at higher pH due to the disruption of the zwitterionic structure. Extrapolated log Do values were compared to actual log D measurements performed for a reference quinolinium compound and for cefpirome. Extrapolated retention factors log kw close to the isoelectric point were also determined by reversed phase HPLC and compared to the log Do values.  相似文献   
53.
We examined how ionizing radiation (IR) delivered under either severe hypoxia (< 0.1% O2) or normoxia affects the expression of hypoxia inducible factor 1alpha (HIF-1alpha) and the angiogenic factors vascular endothelial growth factor (VEGF) and angiopoietins 1, 2 and 4 in U87 human glioblastoma cells. IR was delivered as single doses of 0, 2, 5, 10 and 20 Gy after 6-hr hypoxic incubation and in normoxic controls. Irradiation at any dose did not affect the cellular protein levels of any of the angiopoietins, whereas hypoxia led to increasing levels of both angiopoietin-4 and angiopoietin-2. Levels of angiopoietin-1 protein were unaltered throughout the observation period. A dose-dependent increase in levels of secreted VEGF in the medium occurred after IR at doses from 5-20 Gy. In hypoxic cells, 20 Gy IR induced an additional significant increase in VEGF relative to nonirradiated hypoxic control cells with elevated baseline VEGF levels induced by hypoxia. HIF-1alpha and glucose transporter-1 (Glut-1) were not correspondingly upregulated by IR. Blocking HIF-1alpha by antisense treatment induced a reduced baseline VEGF at normoxia, while the relative upregulation of VEGF by IR was unaffected. These data provide evidence that VEGF is upregulated by IR by mechanisms independent of HIF-1 transactivation.  相似文献   
54.
The neuropeptide galanin is present at high levels within the dorsal root ganglia (DRG) and spinal cord during development and after peripheral nerve damage in the adult. This pattern of expression suggests that it may play a role in the adaptive response of the peripheral nervous system (PNS) to injury. Several experimental paradigms have demonstrated that galanin modulates pain transmission, particularly after nerve injury. In our laboratory we have used a transgenic approach to further elucidate the functions of galanin within the somatosensory system. We have generated mice which over-express galanin (either inducibly after nerve injury, or constitutively), and knock-out (KO) mice, in which galanin is absent in all cells, throughout development and in the adult. Analysis of the nociceptive behaviour of the galanin over-expressing animals, before and after nerve injury, supports the view that galanin is an inhibitory neuromodulator of spinal cord transmission. In apparent contradiction to these findings, galanin KO animals fail to develop allodynia and hyperalgesia after nerve injury. However, further studies have shown that galanin is critical for the developmental survival of a subset of small diameter, unmyelinated sensory neurons that are likely to be nociceptors. This finding may well explain the lack of neuropathic pain-like behaviour after injury in the KO animals. Furthermore, the developmental survival role played by galanin is recapitulated in the adult where the peptide is required for optimal neuronal regeneration after injury, and in the hippocampus where it plays a neuroprotective role after excitotoxic injury.  相似文献   
55.
56.
57.
58.
Plasma YKL-40, as a prognostic tumor marker in recurrent ovarian cancer   总被引:7,自引:0,他引:7  
BACKGROUND: YKL-40, a member of family 18 glycosyl hydrolases, is secreted by cancer cells. The function of YKL-40 in cancer diseases is unknown, but it is a growth factor of connective tissue cells and probably has a role in inflammation and remodeling of the extracellular matrix, a process also involved in metastatic malignant diseases. High serum YKL-40 has been associated with poor prognosis for patients with colorectal and recurrent breast cancer. AIM OF THE STUDY: The purpose of the present study was to examine the prognostic value of plasma YKL-40 in patients presenting with recurring ovarian cancer. METHODS: YKL-40 was determined by ELISA in plasma samples from 73 patients with relapse of ovarian cancer shortly before start of second-line chemotherapy. The endpoint used was death because of ovarian cancer. RESULTS: Plasma YKL-40 was increased in ovarian cancer patients (median 94 micro g/L, range 20-1970 micro g/L) compared with age-matched controls (33 micro g/L, range 20-130 micro g/L) (p < 0.001). Fifty-five per cent of the patients had a plasma YKL-40 level above the upper normal 95th percentile of controls. Patients with high plasma YKL-40 (i.e. > 130 micro g/L or > 160 micro g/L) at the time of relapse had significantly shorter survival than patients with normal levels (respectively p = 0.007 and p = 0.004). Plasma YKL-40 proved to be an independent prognostic factor in a multivariate Cox analysis (YKL-40 > 160 micro g/L; HR = 2.27) (p = 0.006), including serum CA-125 and clinical/histological parameters. CONCLUSION: High plasma YKL-40 is related to short survival in patients with recurrent ovarian cancer.  相似文献   
59.
Hwang SH  Oh HB  Hur SS  Lee MN  Hong SA  Kwon OJ 《Tissue antigens》2005,66(2):145-147
In this report, we describe the identification of an HLA-A*31 nucleotide sequence variant, a new HLA-A*3111, in three members of a Korean family by using sequence-based typing (SBT). The new allele was detected during routine HLA typing by high-resolution SBT. Allele A*3111 showed one nucleotide difference with A*310102 at codon 165 (GTG-->CTG) resulting in an amino acid change from valine to leucine (V165L). Serologic reactivity was shorter than normally expected.  相似文献   
60.
We present a 34-year-old man with an unbalanced translocation between the long arms of chromosome 4 and chromosome 11. He had manifestations of monosomy 11(q23)—minor facial anomalies, abnormal head shape, cryptorchidism; trisomy 4(q32)—hirsutism, renal disease; and manifestations attributable to both imbalances—heart disease, musculoskeletal anomalies, and mental retardation. FISH studies showed that the chromosome 11q23.3 translocation breakpoint was distal to the rare folate sensitive fragile site (FRA11B). The patient is the oldest reported with both imbalance of 4q+ and 11q-. Am. J. Med. Genet. 70:357–360, 1997. © 1997 Wiley-Liss, Inc.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号