全文获取类型
收费全文 | 259篇 |
免费 | 15篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 9篇 |
2020年 | 1篇 |
2019年 | 4篇 |
2018年 | 5篇 |
2017年 | 1篇 |
2016年 | 4篇 |
2015年 | 8篇 |
2014年 | 11篇 |
2013年 | 8篇 |
2012年 | 20篇 |
2011年 | 38篇 |
2010年 | 15篇 |
2009年 | 4篇 |
2008年 | 24篇 |
2007年 | 18篇 |
2006年 | 7篇 |
2005年 | 16篇 |
2004年 | 9篇 |
2003年 | 12篇 |
2002年 | 10篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1998年 | 4篇 |
1997年 | 2篇 |
1993年 | 1篇 |
1990年 | 4篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有274条查询结果,搜索用时 31 毫秒
1.
B. Benko 《Biologia Plantarum》1969,11(5):334-337
In the years 1963–1965 the content of proline, asparagine, glutamic and γ-aminobutyric acids in young apple (Malus cultivars) shoots was studied. Two groups of apple varieties differing in frost resistance were included into experiments: the Yellow Transparent and Oberländer Himbeerapfel varieties as frost-resistant ones and-the Ontario and Reinette du Canada varieties as sensitive to frost. In the course of experiment γ-aminobutyric acid showed a relatively balanced level but glutamic acid, asparagine and especially proline were found in greater amount in the frost-resistant varieties. According to the results of this experiment the amount of proline—along with many other factors—can be considered as one of the indicators of the length of winter dormancy and also of the frost resistance of apple-trees at the beginning of the winter period. 相似文献
2.
Cloning and functional analysis of multiply spliced mRNA species of human immunodeficiency virus type 1 总被引:93,自引:58,他引:35
下载免费PDF全文
![点击此处可从《Journal of virology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
We have used the polymerase chain reaction technique to clone the small multiply spliced mRNA species produced after infection of human cells by a molecular clone of human immunodeficiency virus type 1 (HIV-1). We identified six Rev-expressing mRNAs, which were generated by the use of two splice acceptors located immediately upstream of the rev AUG. The class of small mRNAs included 12 mRNAs expressing Tat, Rev, and Nef. In addition, HIV-1 produced other multiply spliced mRNAs that used alternative splice sites identified by cloning and sequencing. All of these mRNAs were found in the cytoplasm and should be able to produce additional proteins. The coding capacity of the tat, rev, and nef mRNAs was analyzed by transfection of the cloned cDNAs into human cells. The tat mRNAs produced high levels of Tat, but very low levels of Rev and Nef. All the rev mRNAs expressed high levels of both Rev and Nef and were essential for the production of sufficient amounts of Rev. Therefore, HIV-1 uses both alternatively spliced and bicistronic mRNAs for the production of Tat, Rev, and Nef proteins. 相似文献
3.
Myrtus communis L. (myrtle), a typical Mediterranean plant species belonging to the family Myrtaceae, was shown to form arbuscular mycorrhizal
symbioses in nature. Many different spore types were isolated from its rhizosphere and grown in pot cultures; six of them
were identified as Glomus species. In the laboratory, the myrtle root system was colonized by indigenous endophytes as well as by an Italian isolate
of Glomus intraradices. In greenhouse experiments, mycorrhizal inoculation reduced transplant stress in 60-day-old myrtle seedlings; their growth
was renewed immediately after transplanting, whereas non-mycorrhizal plants stopped development. Significantly larger growth
responses were obtained using indigenous fungi than the Italian isolate of Glomus intraradices.
Accepted: 16 January 1997 相似文献
4.
Sujay K. Singh Edward K. Wakeland Ivica Vučak Zoltan A. Nagy Jan Klein 《Immunogenetics》1981,14(3-4):273-281
The B10.STA62 strain carries the H-2
w27 haplotype derived from a wild mouse captured in the vicinity of Ann Arbor, Michigan. Products of two class II loci composing this haplotype, A
and A
, are serologically, biochemically (by tryptic peptide mapping), and functionally indistinguishable from products controlled by the A
b
and A
/b
genes of the B10.A(5R) strain. In contrast, the polypeptide chain controlled by the third class II locus, E
, is different from that controlled by the E
/b
gene. This E
/w27
chain lacks an antigenic determinant present on the Eb molecule and carries determinants lacking on the Eb molecule, the E
/b
and E
/w27
peptide maps differ in at least six peptides, and cytotoxic T cells specific for the E
b
chains do not react with B10.STA62 target cells. This great difference between the E
/b
and E
/w27
chains suggests that the corresponding genes have not been derived from one another by a direct mutational conversion; instead, H-2
w27 appears to be a recombinant haplotype derived by crossing-over between the A
A
duplex and the E
locus. This is the first recombinant discovered separating these class II loci. 相似文献
5.
Cell-mediated lymphocytotoxicity was generated in four strain combinations differing only by the cell-surface expression of the class II E molecule controlled by the H-2 complex. The four combinations were: B10.D2(R107) anti-B10.A(3R), B10.A(4R) anti-B10.A(2R), B10.GD anti-B10.D2(R101), and B10.S(7R) anti-B10.S(9R). In all four of these combinations, the stimulator expresses E molecules on the cell surface, while the responder does not. The cytolytic T lymphocytes generated in the B10.D2(R107) anti-B10.A(3R) and B10.A(4R) anti-B10.A(2R) combinations reacted not only with the stimulator but also with strains that do not express cell-surface E molecules, in particular, strains carrying the H-2
f
and H-2
q
haplotypes. The cross-reactivity with E-negative strains could be blocked by monoclonal antibodies specific for the Af or Aq molecules but not by antibodies recognizing determinants on E or class I (K) molecules. The anti-H-2f cross-reactivity could be inhibited by H-2
q
cold targets and, reciprocally, the anti-H-2q reactivity could be blocked by H-2
f
cold targets. These findings are interpreted as indicating that the cytolytic T lymphocytes stimulated by E molecules can recognize and lyse cells lacking E molecules but expressing A molecules. The observed E-A cross-reactivity supports the notion of structural and functional relatedness between the A and E molecules and suggests a common evolutionary origin of the A- and E-encoding loci. 相似文献
6.
Lucia Vernerova Frantisek Spoutil Miroslav Vlcek Katarina Krskova Adela Penesova Milada Meskova Andrea Marko Katarina Raslova Branislav Vohnout Jozef Rovensky Zdenko Killinger Ivana Jochmanova Ivica Lazurova Guenter Steiner Josef Smolen Richard Imrich 《PloS one》2016,11(4)
IntroductionThe aim of the study was to analyse genetic architecture of RA by utilizing multiparametric statistical methods such as linear discriminant analysis (LDA) and redundancy analysis (RDA).MethodsA total of 1393 volunteers, 499 patients with RA and 894 healthy controls were included in the study. The presence of shared epitope (SE) in HLA-DRB1 and 11 SNPs (PTPN22 C/T (rs2476601), STAT4 G/T (rs7574865), CTLA4 A/G (rs3087243), TRAF1/C5 A/G (rs3761847), IRF5 T/C (rs10488631), TNFAIP3 C/T (rs5029937), AFF3 A/T (rs11676922), PADI4 C/T (rs2240340), CD28 T/C (rs1980422), CSK G/A (rs34933034) and FCGR3A A/C (rs396991), rheumatoid factor (RF), anti–citrullinated protein antibodies (ACPA) and clinical status was analysed using the LDA and RDA.ResultsHLA-DRB1, PTPN22, STAT4, IRF5 and PADI4 significantly discriminated between RA patients and healthy controls in LDA. The correlation between RA diagnosis and the explanatory variables in the model was 0.328 (Trace = 0.107; F = 13.715; P = 0.0002). The risk variants of IRF5 and CD28 genes were found to be common determinants for seropositivity in RDA, while positivity of RF alone was associated with the CTLA4 risk variant in heterozygous form. The correlation between serologic status and genetic determinants on the 1st ordinal axis was 0.468, and 0.145 on the 2nd one (Trace = 0.179; F = 6.135; P = 0.001). The risk alleles in AFF3 gene together with the presence of ACPA were associated with higher clinical severity of RA.ConclusionsThe association among multiple risk variants related to T cell receptor signalling with seropositivity may play an important role in distinct clinical phenotypes of RA. Our study demonstrates that multiparametric analyses represent a powerful tool for investigation of mutual relationships of potential risk factors in complex diseases such as RA. 相似文献
7.
Supriya Khedkar Georgy Smyshlyaev Ivica Letunic Oleksandr
M Maistrenko Luis
Pedro Coelho Askarbek Orakov Sofia K Forslund Falk Hildebrand Mechthild Luetge Thomas S B Schmidt Orsolya Barabas Peer Bork 《Nucleic acids research》2022,50(6):3155
Prokaryotic Mobile Genetic Elements (MGEs) such as transposons, integrons, phages and plasmids, play important roles in prokaryotic evolution and in the dispersal of cargo functions like antibiotic resistance. However, each of these MGE types is usually annotated and analysed individually, hampering a global understanding of phylogenetic and environmental patterns of MGE dispersal. We thus developed a computational framework that captures diverse MGE types, their cargos and MGE-mediated horizontal transfer events, using recombinases as ubiquitous MGE marker genes and pangenome information for MGE boundary estimation. Applied to ∼84k genomes with habitat annotation, we mapped 2.8 million MGE-specific recombinases to six operational MGE types, which together contain on average 13% of all the genes in a genome. Transposable elements (TEs) dominated across all taxa (∼1.7 million occurrences), outnumbering phages and phage-like elements (<0.4 million). We recorded numerous MGE-mediated horizontal transfer events across diverse phyla and habitats involving all MGE types, disentangled and quantified the extent of hitchhiking of TEs (17%) and integrons (63%) with other MGE categories, and established TEs as dominant carriers of antibiotic resistance genes. We integrated all these findings into a resource (proMGE.embl.de), which should facilitate future studies on the large mobile part of genomes and its horizontal dispersal. 相似文献
8.
Mihanović M Restek-Petrović B Babić G Sain I Telarović S Zilić-Dzeba J 《Collegium antropologicum》2004,28(1):385-391
Schizophrenia and other psychotic disorders as well as the delirium caused by abstinence from alcohol and accute state of drunkenness appear at the very top of the list of factors, which are positively correlated with involuntary hospitalization of patients. This is at the same time a confirmation of the data found in literature considering psychosis an essential factor of involuntary hospitalization; the same referring to the male sex was not, however, confirmed by the results obtained in the first and second research period. Regarding the positive correlation between schizophrenia and other psychotic disturbances, dementia, delirium and other cognitive impairments including the delirium caused by abstinence from alcohol and an accute state of drunkenness on the one side and the high rate of involuntary hospitalization on the other, there is no statistically significant difference between the period preceding and the period following the alterations and amendments to the Law on the protection of patients with mental disorders. 相似文献
9.
10.
Christoph?ScheichEmail author Dietmar?Leitner Volker?Sievert Martina?Leidert Brigitte?Schlegel Bernd?Simon Ivica?Letunic Konrad?Büssow Anne?Diehl 《BMC structural biology》2004,4(1):4