全文获取类型
收费全文 | 124篇 |
免费 | 22篇 |
出版年
2021年 | 2篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 4篇 |
2016年 | 2篇 |
2015年 | 6篇 |
2014年 | 4篇 |
2013年 | 2篇 |
2012年 | 3篇 |
2011年 | 3篇 |
2010年 | 4篇 |
2009年 | 8篇 |
2008年 | 3篇 |
2007年 | 2篇 |
2004年 | 1篇 |
2002年 | 1篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1999年 | 6篇 |
1998年 | 8篇 |
1997年 | 3篇 |
1996年 | 5篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 7篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 5篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有146条查询结果,搜索用时 468 毫秒
101.
Aquaporins (AQP) 1, 2, 3 and 4 belong to the aquaporin water channel family and play an important role in urine concentration by reabsorption of water from renal tubule fluid. Renal AQPs have not been reported in the yak (Bos grunniens), which resides in the Qinghai Tibetan Plateau. We investigated AQPs 1?4 expressions in the kidneys of Yak using immunohistochemical staining. AQP1 was expressed mainly in the basolateral and apical membranes of the proximal tubules and descending thin limb of the loop of Henle. AQP2 was detected in the apical plasma membranes of collecting ducts and distal convoluted tubules. AQP3 was located in the proximal tubule, distal tubule and collecting ducts. AQP4 was located in the collecting ducts, distal straight tubule, glomerular capillaries and peritubular capillaries. The expression pattern of AQPs 1?4 in kidney of yak was different from other species, which possibly is related to kidney function in a high altitude environment. 相似文献
102.
Previous investigations on the monkey kidney COS cell line demonstrated the
weak expression of fucosylated cell surface antigens and presence of
endogenous fucosyltransferase activities in cell extracts. RT-PCR analyses
have now revealed expression of five homologs of human fucosyltransferase
genes, FUT1, FUT4, FUT5, FUT7, and FUT8, in COS cell mRNA. The enzyme in
COS cell extracts acting on unsialylated Type 2 structures is closely
similar in its properties to the alpha1,3- fucosyltransferase encoded by
human FUT4 gene and does not resemble the product of the FUT5 gene.
Although FUT1 is expressed in the COS cell mRNA, it has not been possible
to demonstrate alpha1,2- fucosyltransferase activity in cell extracts but
the presence of Le(y) and blood-group A antigenic determinants on the cell
surface imply the formation of H-precursor structures at some stage. The
most strongly expressed fucosyltransferase in the COS cells is the
alpha1,6-enzyme transferring fucose to the innermost N -acetylglucosamine
unit in N - glycan chains; this enzyme is similar in its properties to the
product of the human FUT8 gene. The enzymes resembling the human FUT4 and
FUT8 gene products both had pH optima of 7.0 and were resistant to 10 mM
NEM. The incorporation of fucose into asialo-fetuin was optimal at 5.5 and
was inhibited by 10 mM NEM. This result initially suggested the presence of
a third fucosyltransferase expressed in the COS cells but we have now shown
that triantennary N- glycans with terminal nonreducing galactose units,
similar to those present in asialo-fetuin, are modified by a weak
endogenous beta-galactosidase in the COS cell extracts and thereby rendered
suitable substrates for the alpha1,6- fucosyltransferase.
相似文献
103.
M Kale R Ramsey-Goldman S Bernatsky MB Urowitz D Gladman PR Fortin M Petri E Yelin S Manzi S Edworthy O Nived S-C Bae D Isenberg A Rahman JG Hanly C Gordon S Jacobsen E Ginzler DJ Wallace GS Alarcón MA Dooley L Gottesman K Steinsson A Zoma J-L Senécal S Barr G Sturfelt L Dreyer L Criswell J Sibley JL Lee AE Clarke 《Arthritis research & therapy》2012,14(Z3):A15
104.
105.
106.
Selpi Christopher H Bryant Graham JL Kemp Janeli Sarv Erik Kristiansson Per Sunnerhagen 《BMC bioinformatics》2009,10(1):451
Background
Some upstream open reading frames (uORFs) regulate gene expression (i.e., they are functional) and can play key roles in keeping organisms healthy. However, how uORFs are involved in gene regulation is not yet fully understood. In order to get a complete view of how uORFs are involved in gene regulation, it is expected that a large number of experimentally verified functional uORFs are needed. Unfortunately, wet-experiments to verify that uORFs are functional are expensive. 相似文献107.
108.
In vivo expansion of functionally integrated GABAergic interneurons by targeted increase in neural progenitors 下载免费PDF全文
109.
Nested PCR for ultrasensitive detection of the potato ring rot bacterium, Clavibacter michiganensis subsp. sepedonicus. 总被引:1,自引:0,他引:1 下载免费PDF全文
Oligonucleotide primers derived from sequences of the 16S rRNA gene (CMR16F1, CMR16R1, CMR16F2, and CMR16R2) and insertion element IS1121 of Clavibacter michiganensis subsp. sepedonicus (CMSIF1, CMSIR1, CMSIF2, and CMISR2) were used in nested PCR to detect the potato ring rot bacterium C. michiganensis subsp. sepedonicus. Nested PCR with primer pair CMSIF1-CMSIR1 followed by primer pair CMSIF2-CMSIR2 specifically detected C. michiganensis subsp. sepedonicus, while nested PCR with CMR16F1-CMR16R1 followed by CMR16F2-CMR16R2 detected C. michiganensis subsp. sepedonicus and the other C. michiganensis subspecies. In the latter case, C. michiganensis subsp. sepedonicus can be differentiated from the other subspecies by restriction fragment length polymorphism (RFLP) analyses of the nested PCR products (16S rDNA sequences). The nested PCR assays developed in this work allow ultrasensitive detection of very low titers of C. michiganensis subsp. sepedonicus which may be present in symptomiess potato plants or tubers and which cannot be readily detected by direct PCR (single PCR amplification). RFLP analysis of PCR products provides for an unambiguous confirmation of the identify of C. michiganensis subsp. sepedonicus. 相似文献
110.
Combining protein evolution and secondary structure 总被引:19,自引:9,他引:10
An evolutionary model that combines protein secondary structure and amino
acid replacement is introduced. It allows likelihood analysis of aligned
protein sequences and does not require the underlying secondary (or
tertiary) structures of these sequences to be known. One component of the
model describes the organization of secondary structure along a protein
sequence and another specifies the evolutionary process for each category
of secondary structure. A database of proteins with known secondary
structures is used to estimate model parameters representing these two
components. Phylogeny, the third component of the model, can be estimated
from the data set of interest. As an example, we employ our model to
analyze a set of sucrose synthase sequences. For the evolution of sucrose
synthase, a parametric bootstrap approach indicates that our model is
statistically preferable to one that ignores secondary structure.
相似文献