全文获取类型
收费全文 | 473篇 |
免费 | 41篇 |
国内免费 | 46篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 18篇 |
妇产科学 | 1篇 |
基础医学 | 73篇 |
口腔科学 | 13篇 |
临床医学 | 72篇 |
内科学 | 95篇 |
皮肤病学 | 14篇 |
神经病学 | 9篇 |
特种医学 | 149篇 |
外科学 | 17篇 |
综合类 | 11篇 |
预防医学 | 23篇 |
药学 | 47篇 |
肿瘤学 | 17篇 |
出版年
2021年 | 6篇 |
2020年 | 1篇 |
2019年 | 3篇 |
2018年 | 3篇 |
2016年 | 7篇 |
2015年 | 11篇 |
2014年 | 5篇 |
2013年 | 12篇 |
2012年 | 10篇 |
2011年 | 10篇 |
2010年 | 7篇 |
2009年 | 10篇 |
2008年 | 12篇 |
2007年 | 39篇 |
2006年 | 5篇 |
2005年 | 8篇 |
2004年 | 2篇 |
2003年 | 5篇 |
2002年 | 7篇 |
2001年 | 5篇 |
2000年 | 12篇 |
1999年 | 18篇 |
1998年 | 29篇 |
1997年 | 34篇 |
1996年 | 28篇 |
1995年 | 26篇 |
1994年 | 24篇 |
1993年 | 24篇 |
1992年 | 19篇 |
1991年 | 10篇 |
1990年 | 12篇 |
1989年 | 19篇 |
1988年 | 19篇 |
1987年 | 11篇 |
1986年 | 14篇 |
1985年 | 16篇 |
1984年 | 4篇 |
1983年 | 9篇 |
1982年 | 8篇 |
1981年 | 9篇 |
1980年 | 7篇 |
1979年 | 5篇 |
1978年 | 7篇 |
1977年 | 14篇 |
1976年 | 9篇 |
1975年 | 4篇 |
1973年 | 1篇 |
排序方式: 共有560条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Perforated colorectal neoplasms: correlation of clinical, contrast enema, and CT examinations 总被引:2,自引:0,他引:2
Hulnick DH; Megibow AJ; Balthazar EJ; Gordon RB; Surapenini R; Bosniak MA 《Radiology》1987,164(3):611-615
Results of clinical, contrast enema (CE), and computed tomographic (CT) examinations in 39 patients with perforated colorectal neoplasms were retrospectively reviewed. Twenty patients were toxemic at initial presentation, but in only four patients was the diagnosis of perforated colorectal neoplasm initially suspected clinically. CE study was performed in 22 patients and enabled the diagnosis of perforated neoplasm in 11 cases, neoplasm alone in eight, and neither neoplasm nor perforation in three. CT was performed in 38 patients and enabled the diagnosis of perforated neoplasm in 36; pericolic phlegmon but no mass lesion was evident in two. In 16 patients, CT also demonstrated metastatic disease. Because of its reliability in establishing the diagnosis and staging the extent of the inflammatory and neoplastic disease, CT is indicated in cases of suspected or proved perforated colorectal neoplasm and in cases in which CE study findings are indeterminate or suggestive of perforated neoplasm. 相似文献
5.
6.
Surgical glove powders bind latex antigens. 总被引:4,自引:0,他引:4
Latex surgical gloves have recently been identified as a potential source of allergens. Much of the current information suggests that the soluble proteins in latex may cause significant reactions in sensitive individuals. The starch powders used as a lubricant on some latex gloves have also been identified as potential allergens in some patients. In this study, we determined these powders to act as potential carriers of latex allergens. We have produced a polyclonal antiserum to be used as a reagent to study latex proteins. By Western blot analysis, we identified a significant interaction between latex proteins and starch powders. The binding of latex proteins to starch particles results in a glove particle that may have an increased potential to act as an allergen. The latex protein-starch particles represent a potential mechanism for exposure and sensitization of health care workers to latex allergens. Elimination of these particles from the operating room should reduce the route of sensitization and the potential for adverse reactions to latex. 相似文献
7.
Coralline hydroxyapatite bone graft substitutes: preliminary report of radiographic evaluation 总被引:1,自引:0,他引:1
A new bone graft substitute made by conversion of the calcium carbonate exoskeleton of reef-building sea coral into hydroxyapatite has recently become clinically available. The normal radiographic appearance of two forms of this material is described. In the immediate postoperative period, the exoskeletal architecture of these implants is readily appreciated. With graft incorporation over the ensuing months, their intrinsic structure is gradually lost in association with poor marginal definition. Evolving radiographic findings reflect the biocompatible nature of these implants, which provides the potential for ingrowth of native bone with preservation of the coralline scaffold, resulting in enhanced biomechanical properties. 相似文献
8.
A 48-kilodalton Mycoplasma fermentans membrane protein induces cytokine secretion by human monocytes.
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Mycoplasma fermentans is one of several Mycoplasma species that have been reported to stimulate tumor necrosis factor (TNF) secretion from monocytes. This activity has been associated primarily with the mycoplasma membrane fraction. In this article, we have characterized a membrane protein that stimulates TNF and interleukin 1 beta secretion. The TNF-releasing activity partitioned into the Triton X-114 detergent phase, suggesting that the molecules is hydrophobic. The secretion of TNF is elevated in the presence of serum, which suggests that a serum component may play a role in the interaction between this mycoplasma protein and monocytes. Treatment of monocytes with monoclonal anti-CD14 antibody had no effect on the levels of TNF-releasing activity. By using the monocyte Western blot (immunoblot) technique, we have determined the molecular mass of the active molecule to be 48 kDa. This molecule appears to be distinct from the recently described family of variable lipoproteins of M. fermentans. Mycoplasma particulate material treated with proteinase K lost all inducing activity, whereas lipoprotein lipase-treated samples retained some level of activity. 相似文献
9.
Beezhold DH Hickey VL Sutherland MF O'Hehir RE 《International archives of allergy and immunology》2004,134(4):334-340
BACKGROUND: Hev b 5 is a potent latex allergen. In this study, we characterize the linear B-cell epitopes for three monoclonal antibodies (mAbs) to Hev b 5. METHODS: The mAbs included 2 IgG1 (6A10, 3G3) and 1 IgG2b (6F6) isotypes. We used SPOTscan analysis with overlapping octapeptides to identify the binding regions for the antibodies and then methionine substitution analysis to further define the critical amino acids (aa) in each epitope. Site-directed mutagenesis was used to selectively eliminate the IgG binding for each epitope and single and multiple mutations were expressed as recombinant GST fusion proteins. Antibody recognition of the mutant proteins was determined by inhibition ELISA. RESULTS: All three mAbs recognized the same aa sequence by SPOTs analysis with slight variations, and this epitope was repeated 3 times in the Hev b 5 sequence; APETEK (63-68), PAEGEK (120-125), and PAEEEK (126-131). Sequential methionine substitution by SPOTsalogue identified K68, E122, and K131 as critical aa in each epitope to change by site-directed mutagenesis. Inhibition ELISA with the mutant proteins indicated that epitope 126-131 was the dominant epitope, but mutation of epitope 120-125 was also required to eliminate mAb reactivity to Hev b 5. The antibodies did not appear to recognize the epitope 63-68 in the recombinant fusion protein. CONCLUSIONS: We identified an immunodominant B-cell epitope in Hev b 5 that is repeated 3 times within the sequence, making Hev b 5 multivalent. Well-characterized monoclonals recognizing repeated epitopes would be a good choice for immunodetection of Hev b 5 in glove extracts where individual epitopes could get altered by the manufacturing process. 相似文献
10.
Neurofibromatosis 2 (NF2) is an inherited cancer syndrome resulting from
mutations in the NF2 tumor suppressor gene. Analysis of NF2 mutations has
revealed some general genotype-phenotype correlations. Severe disease has
been associated with mutations that produce a premature termination while
more mild disease has been associated with missense mutations. Here, we
provide experimental proof for these genotype-phenotype correlations by
demonstrating that nonsense mutations fail to produce stable merlin protein
while missense mutations result in the generation of merlin proteins
defective in negative growth regulation. This inability to suppress cell
growth may result from defects in the function of merlin at several levels,
including failure to form an intramolecular complex. Based on these
findings, we propose a model for merlin growth suppression that provides a
framework for analyzing NF2 patient mutations and merlin function.
相似文献