全文获取类型
收费全文 | 191篇 |
免费 | 13篇 |
专业分类
儿科学 | 14篇 |
妇产科学 | 2篇 |
基础医学 | 39篇 |
口腔科学 | 1篇 |
临床医学 | 34篇 |
内科学 | 34篇 |
皮肤病学 | 1篇 |
神经病学 | 3篇 |
特种医学 | 21篇 |
外科学 | 2篇 |
预防医学 | 43篇 |
药学 | 9篇 |
肿瘤学 | 1篇 |
出版年
2021年 | 3篇 |
2020年 | 4篇 |
2016年 | 14篇 |
2015年 | 13篇 |
2014年 | 8篇 |
2013年 | 6篇 |
2012年 | 5篇 |
2011年 | 7篇 |
2010年 | 5篇 |
2009年 | 4篇 |
2008年 | 6篇 |
2007年 | 4篇 |
2006年 | 9篇 |
2005年 | 13篇 |
2004年 | 6篇 |
2003年 | 3篇 |
2002年 | 11篇 |
2001年 | 6篇 |
2000年 | 8篇 |
1999年 | 6篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1969年 | 2篇 |
1968年 | 1篇 |
1967年 | 3篇 |
1966年 | 3篇 |
1961年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有204条查询结果,搜索用时 31 毫秒
1.
2.
Cyclic peptide disulfides of the general formula were synthesized from the corresponding peptide derivatives [Boc-Cys(Trt)(Gly)-n-Cys(Trt)-OBut] by oxidation with iodine in methanol and by subsequent removal of the terminal groups with trifluoroacetic acid. Acid ionization constants of the obtained peptides were determined by potentiometric titration in aqueous KCl (0.1 mol/L) medium. All compounds have two dissociable hydrogens, corresponding to carboxyl (pK1= 2.35–2.84) and to terminal amino group (pK2= 5.61–6.93); pK1, values show first an upward and then a downward trend with the increase in ring size; the opposite is true for pK2, values. These trends could be tentatively attributed to the intramolecular salt bridge (-COO——-NH+3-) formation. 相似文献
3.
4.
John L. Butler VI MS 《Journal of family psychotherapy》2013,24(1):87-88
No abstract available for this article. 相似文献
5.
6.
7.
Impact of amino acid sequence variation of a determinant(s) on the antigenic properties of hepatitis B virus HBsAg 总被引:1,自引:0,他引:1
Ulanova TI Yokosawa J Puzyrev VF Obriadina AP Burkov AN Khudyakov Y Fields H 《Voprosy virusologii》2007,52(3):13-15
Impact of amino acid sequence variation on the antigenic properties of the surface hepatitis B virus antigen HBsAg was studied. Eleven recombinant HBsAg variants of wild (adr, ayw2, adw2, adw4, aywl, adw2) and vaccine escape (adw2 T126S, adw2 Q129L, adw2 Q129R, adw2 T143K, adw2 Q145R, aywl Q145A) were obtained. All the recombinant antigens were tested on a panel of 43 monoclonal antibodies (MAb) specific to different HBsAg determinants. Amino acid sequence variation of the a-determinant of HBsAg was shown to significantly affect its immunological responsiveness and antigenic properties. Amino acid substitution in different positions or in the same position, but for various amino acids may differently affect these properties. 相似文献
8.
Distinguishing acute from chronic and resolved hepatitis C virus (HCV) infections by measurement of anti-HCV immunoglobulin G avidity index 下载免费PDF全文
Klimashevskaya S Obriadina A Ulanova T Bochkova G Burkov A Araujo A Stramer SL Tobler LH Busch MP Fields HA 《Journal of clinical microbiology》2007,45(10):3400-3403
An assay to measure avidity index (AI) was developed to diagnose incident hepatitis C virus (HCV) infections. The assay demonstrated an AI value statistically significantly lower in primary HCV infections than in chronic infections. When the assay was applied to past resolved infections, the difference in AI values was not as significant as the difference between incident and chronic infections. Lower AI values obtained in past resolved infections may be directly related to lower levels of immunoglobulin G anti-HCV in past resolved infections than in either new infections or chronic infections. 相似文献
9.
A GCH1 haplotype confers sex‐specific susceptibility to pain crises and altered endothelial function in adults with sickle cell anemia 下载免费PDF全文
Zhengyuan Wang Lena Diaw Lita Freeman Krupa Desai Michael Dizon Darlene Allen Colin Cunnington Keith M. Channon Jacqueline Milton Stephen W. Hartley Vikki Nolan Gregory J. Kato Martin H. Steinberg David Goldman James G. Taylor VI 《American journal of hematology》2014,89(2):187-193
GTP cyclohydrolase (GCH1) is rate limiting for tetrahydrobiopterin (BH4) synthesis, where BH4 is a cofactor for nitric oxide (NO) synthases and aromatic hydroxylases. GCH1 polymorphisms are implicated in the pathophysiology of pain, but have not been investigated in African populations. We examined GCH1 and pain in sickle cell anemia where GCH1 rs8007267 was a risk factor for pain crises in discovery (n = 228; odds ratio [OR] 2.26; P = 0.009) and replication (n = 513; OR 2.23; P = 0.004) cohorts. In vitro, cells from sickle cell anemia subjects homozygous for the risk allele produced higher BH4. In vivo physiological studies of traits likely to be modulated by GCH1 showed rs8007267 is associated with altered endothelial dependent blood flow in females with SCA (8.42% of variation; P = 0.002). The GCH1 pain association is attributable to an African haplotype with where its sickle cell anemia pain association is limited to females (OR 2.69; 95% CI 1.21–5.94; P = 0.01) and has the opposite directional association described in Europeans independent of global admixture. The presence of a GCH1 haplotype with high BH4 in populations of African ancestry could explain the association of rs8007267 with sickle cell anemia pain crises. The vascular effects of GCH1 and BH4 may also have broader implications for cardiovascular disease in populations of African ancestry. Am. J. Hematol. 89:187–193, 2014. © 2013 Wiley Periodicals, Inc. 相似文献