全文获取类型
收费全文 | 115篇 |
免费 | 19篇 |
出版年
2021年 | 1篇 |
2019年 | 4篇 |
2018年 | 5篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2015年 | 11篇 |
2014年 | 6篇 |
2013年 | 6篇 |
2012年 | 13篇 |
2011年 | 5篇 |
2010年 | 7篇 |
2009年 | 10篇 |
2008年 | 7篇 |
2007年 | 4篇 |
2006年 | 1篇 |
2005年 | 5篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 1篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1999年 | 6篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1988年 | 2篇 |
1986年 | 1篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1977年 | 2篇 |
排序方式: 共有134条查询结果,搜索用时 31 毫秒
11.
Spores potentially dispersed to longer distances are more tolerant to ultraviolet radiation: A case study in the moss genus Orthotrichum
下载免费PDF全文
![点击此处可从《American journal of botany》网站下载免费的PDF全文](/ch/ext_images/free.gif)
12.
De Palma AM Heggermont W Leyssen P Pürstinger G Wimmer E De Clercq E Rao A Monforte AM Chimirri A Neyts J 《Biochemical and biophysical research communications》2007,353(3):628-632
Despite the fact that enteroviruses are implicated in a variety of human diseases, there is no approved therapy for the treatment of enteroviral infections. Here, a series of 2,6-dihalophenyl-substituted 1H,3H-thiazolo[3,4-a]benzimidazoles with anti-enterovirus activity is reported. The compounds elicit potent activity against coxsackievirus A9, echovirus 9 and 11 and all six strains of coxsackievirus B. A structure-activity relationship analysis revealed that the presence of substituents at position 6 of the tricyclic system positively influences the antiviral activity, whereas substitutions at position 7 are less favorable. In particular a 6-trifluoromethyl substitution leads to a substantial improvement of the antiviral activity as compared to the unsubstituted structure. Furthermore, an additional introduction of a 2-Cl, 6-F substitution on the phenyl at C-1 results in a further increase of the antiviral activity. Hence, 1-(2-chloro-6-fluorophenyl)-6-trifluoromethyl-1H,3H-thiazolo[3,4-a]benzimidazole results in a dose-dependent inhibition of viral replication with a 50% effective concentration (EC50) of 0.41 microg/ml without any detectable cytotoxicity at the highest concentration (100 microg/ml) tested. 相似文献
13.
14.
In previous work we observed that the decoction of Salvadora persica L. possessed significant protective action against ethanol and stress-induced ulcers. This study was designed to confirm the antiulcer activity of Salvadora persica decoction using optical microscopy. The elements of gastric mucosa tended to be reestablished normally in treated rats. 相似文献
15.
Renato M Salgado Luciane P Capelo Rodolfo R Favaro Jocelyn D Glazier John D Aplin Telma MT Zorn 《Reproductive biology and endocrinology : RB&E》2009,7(1):60
Background
Remodeling of the extracellular matrix is one of the most striking features observed in the uterus during the estrous cycle and after hormone replacement. Versican (VER) is a hyaluronan-binding proteoglycan that undergoes RNA alternative splicing, generating four distinct isoforms. This study analyzed the synthesis and distribution of VER in mouse uterine tissues during the estrous cycle, in ovariectomized (OVX) animals and after 17beta-estradiol (E2) and medroxyprogesterone (MPA) treatments, either alone or in combination. 相似文献16.
17.
Bottari B Maccari R Monforte F Ottanà R Vigorita MG Bruno G Nicolò F Rotondo A Rotondo E 《Bioorganic & medicinal chemistry》2001,9(8):2203-2211
The reaction of 2,6-diacetylpyridine (dap) and isonicotinoyl- or benzoylhydrazide leads to bishydrazones H(2)dapin (1a) and H(2)dapb (1b), respectively. The condensation can either take place as a bimolecular kinetic process between the two reactants or as a monomolecular metal-templated synthesis in the presence of nickel(II) ions. In the latter case the reaction products are charged 2,6-diacetylpyridine bis(hydrazone) nickel(II) complexes, which can be easily deprotonated to neutral hydrazonates. Diffractometric analysis of one of these [Ni(dapb)](2) (8b) has shown a binuclear structure with two octahedral nickel(II) ions bridged by two helicoidal dap (bishydrazonates) in a spheroidal structure of C(2V) symmetry. The synthesized complexes 8 are promising as antimycobacterial agents against M. tuberculosis H37Rv. In particular, 8b displays significant activity (MIC=0.025 microg/mL) 10-fold higher than rifampin and equal to isoniazid, while its ligand is ineffective. Compound 8b is also capable of reducing HIV-induced cytopathogenic effect in human T(4 )lymphocytes. 相似文献
18.
A. J. Monforte S. D. Tanksley 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(3-4):471-479
The near-isogenic Line TA523, containing a 40-cM introgression at the bottom of chromosome 1 from Lycopersicon hirsutum acc. LA1777, affects several agronomically important traits. A set of recombinant lines (subNILs) derived from the original
NIL TA523 were developed in order to fine-map, by substitution mapping, the genetic factors included within the original introgression.
In the current experiment, TA523 showed redder, rounded, less pigmented shoulder, lower-weighted fruits and higher brix, whereas
higher yield and brix*yield was observed only in the hybrid TA253×TA209 suggesting heterosis for these traits. By substitution
mapping we mapped independent genetic loci affecting brix, yield and fruit shape, whereas fruit weight, shoulder pigmentation
and external color mapped to a position coincident with the brix locus. Analysis of the subNILs revealed that the gene action
of most of the QTLs was additive or nearly additive. The exception was for the yield QTL which was dominant (d/a=0.7), eliminating
the possibility that yield increase is due to true overdominance at a single gene locus. However, no negative yield effects
were detected in other regions of the introgressed segment, as would be predicted by a dominance complementation model. Therefore,
epistatic interactions among genetic factors along the introgressed segment are suggested as the cause of yield heterosis.
Results from this study, combined with previous experiments involving different tomato wild species, demonstrate that the
base of chromosome 1 of tomato contains multiple QTLs affecting various agronomic and fruit traits and that these effects
can not be attributed to the pleiotropic effects of a single locus.
Received: 21 April 1999 / Accepted: 17 June 1999 相似文献
19.
20.
A. J. Monforte M. J. Asíns E. A. Carbonell 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,95(4):706-713
A study of genotype-by-salinity interaction was carried out to compare the behavior of quantitative trait loci (QTLs) in
two F2 populations derived from crosses between the cherry tomato, Lycopersicon esculentum Mill. var. cerasiforme, and two wild relatives Lycopersicon pimpinellifolium (Jusl.) Mill. and Lycopersicon chesmannii f. minor (Hook. f.) Mull., grown at two environmental conditions (optimum and high salinity). QTLs for earliness and fruit yield could
be classified into four groups: “response-sensitive”, those detected only under control conditions or whose contribution significantly
decreased in salinity; “response-tolerant”, detected only in salinity or in which the direction of their additive effects
changed; “constitutive”, detected in both growing conditions; and “altered” QTLs, those where the degree of dominance changed
according to the presence or absence of salt. Epistatic interactions were also influenced by the salt treatment. This differential
allele effect at some (non-constitutive) QTLs induced by salt stress will make selection under an “optimum environment” unfruitful
for the “response-tolerant” QTLs. Similarly, selection under salinity will ignore “response-sensitive” QTLs. Given that salinity
is highly variable in the field, marker-assisted selection should take into account not only the “response-tolerant” but also
the “response-sensitive” QTLs although there might be cases where selection in some QTLs for both conditions is not feasible.
Comparing both populations, very few QTLs showed the same behavior.
Received: 5 August 1996 / Accepted: 25 October 1996 相似文献