全文获取类型
收费全文 | 324篇 |
免费 | 9篇 |
国内免费 | 11篇 |
出版年
2024年 | 2篇 |
2023年 | 1篇 |
2022年 | 11篇 |
2021年 | 8篇 |
2020年 | 6篇 |
2019年 | 9篇 |
2018年 | 16篇 |
2017年 | 4篇 |
2016年 | 28篇 |
2015年 | 65篇 |
2014年 | 51篇 |
2013年 | 34篇 |
2012年 | 20篇 |
2011年 | 10篇 |
2010年 | 8篇 |
2009年 | 5篇 |
2008年 | 11篇 |
2007年 | 11篇 |
2006年 | 8篇 |
2005年 | 10篇 |
2004年 | 7篇 |
2003年 | 2篇 |
2002年 | 4篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1986年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有344条查询结果,搜索用时 15 毫秒
51.
O. A. Radchenko I. A. Chereshnev M. V. Nazarkin A. V. Petrovskaya E. A. Chegodaeva 《Russian Journal of Marine Biology》2008,34(2):126-130
Nucleotide sequences of the mtDNA COI and cytochrome b genes were determined in Magadanichthys skopetsi, a member of the new monotypic genus Magadanichthys, endemic to the northern coast of the Sea of Okhotsk. Comparison of this species with other representatives of the subfamily Gymnelinae (family Zoarcidae) revealed high genetic similarity of M. skopetsi to Hadropareia middendorffii and considerable differences between these species and Gymnelopsis ochotensis. 相似文献
52.
53.
Ectomycorrhizal fungi are shared between seedlings and adults in a monodominant Gilbertiodendron dewevrei rain forest in Cameroon
下载免费PDF全文
![点击此处可从《Biotropica》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Adrien Taudière Nogaye Niang Cheikh Ndiaye Mathieu Sauve Nérée Onguene Awana Mieke Verbeken André De Kesel Seynabou Séne Abdala G. Diédhiou Violette Sarda Omar Sadio Maïmouna Cissoko Ibrahima Ndoye Amadou M. Bâ 《Biotropica》2017,49(2):256-267
Ectomycorrhizal networks may facilitate the establishment and survival of seedlings regenerating under the canopies of tropical forests and are often invoked as a potential contributor to monodominance. We identified ectomycorrhizal fungi in a monodominant Gilbertiodendron dewevrei (Fabaceae) rain forest in Cameroon, using sporocarps and ectomycorrhizae of three age categories (seedlings, intermediate trees, and large trees) and tentatively revealed nutrient transfer through ectomycorrhizal networks by measuring spontaneous isotopic (13C and 15N) abundances in seedlings. Sporocarp surveys revealed fewer ectomycorrhizal fungal taxa (59 species from 1030 sporocarps) than molecular barcoding of ectomycorrhizal roots (75 operational taxonomic units from 828 ectomycorrhizae). Our observations suggest that ectomycorrhizal fungal diversity is similar to that in other mixed tropical forests and provide the first report of the Tuber‐Helvella lineage in a tropical forest. Despite some differences, all age categories of G. dewevrei had overlapping ectomycorrhizal fungal communities, with families belonging to Thelephoraceae, Russulaceae, Sebacinaceae, Boletaceae, and Clavulinaceae. Of the 49 operational taxonomic units shared by the three age categories (65.3% of the ectomycorrhizal fungal community), 19 were the most abundant on root tips of all categories (38.7% of the shared taxa), supporting the likelihood of ectomycorrhizal networks. However, we obtained no evidence for nutrient transfer from trees to seedlings. We discuss the composition of the ectomycorrhizal fungal community among the G. dewevrei age categories and the possible role of common ectomycorrhizal networks in this rain forest. 相似文献
54.
55.
Jing H Na T Zhang W Wu G Liu C Peng JB 《Biochemical and biophysical research communications》2011,(4):979-984
With-no-lysine (K) kinase 4 (WNK4) is a protein serine/threonine kinase associated with a Mendelian form of hypertension. WNK4 is an integrative regulator of renal transport of Na+, K+, and Cl− as shown in Xenopus oocyte system. In addition, WNK4 enhances the surface expression of epithelial Ca2+ channel TRPV5, which plays a key role in the fine tuning of renal Ca2+ reabsorption. Variations in the magnitude of WNK4-mediated regulation on TRPV5 in Xenopus oocytes suggest additional cellular components with limited expression are required for the regulation. In this study, we identified the Na+/H+ exchanger regulating factor 2 (NHERF2) as a critical component for the positive regulation of TRPV5 by WNK4. NHERF2 augmented the positive effect of WNK4 on TRPV5, whereas its homolog NHERF1 had no effect when tested in the Xenopus oocyte system. The C-terminal PDZ binding motif of TRPV5 was required for the regulation by NHERF2. While NHERF2 interacted with TRPV5, no association between NHERF2 and WNK4 was detected using a GST pull-down assay. WNK4 increased the forward trafficking of TRPV5; however, it also caused an accelerated decline of the functional TRPV5 channels at later stage of co-expression. NHERF2 stabilized TRPV5 at the plasma membrane without interrupting the forward trafficking of TRPV5, thus prevented the decline of functional TRPV5 channel caused by WNK4 at later stage. The complementary and orderly regulations of WNK4 and NHERF2 allow TRPV5 functions at higher level for a longer period to maximize Ca2+ influx. 相似文献
56.
57.
58.
Yue Qiu Zuo-Yang Zhang Wei-Dong Du Lei Ye Song Xu Xian-Bo Zuo Fu-Sheng Zhou Gang Chen Xue-Ling Ma Marion E. Schneider Hong-Zhen Xia Yuan Zhou Ji-Feng Wu Xu Yuan-Hong Xue-Jun Zhang 《Gene》2014
The purpose of this study was to investigate whether risk of gastric cancer (GC) was associated with single nucleotide polymorphisms (SNPs) in a gene cluster on the chromosome 17q12-q21 (ERBB2 amplicon) in the Chinese Han population. We detected twenty-six SNPs in this gene cluster containing steroidogenic acute regulatory-related lipid transfer domain containing 3 (STARD3), protein phosphatase 1 regulatory subunit 1B (PPP1R1B/DARPP32), titin-cap (TCAP), per1-like domain containing 1(PERLD1/CAB2), human epidermal growth factor receptor-2 (ERBB2/HER2), zinc-finger protein subfamily 1A 3 (ZNFN1A3/IKZF3) and DNA topoisomerase 2-alpha (TOP2A) genes in 311 patients with GC and in 425 controls by Sequenom. We found no associations between genetic variations and GC risk. However, haplotype analysis implied that the haplotype CCCT of STARD3 (rs9972882, rs881844, rs11869286 and rs1877031) conferred a protective effect on the susceptibility to GC (P = 0.043, odds ratio [OR] = 0.805, 95% confidence intervals [95% CI] = 0.643–0.992). The STARD3 rs1877031 TC genotype endued histogenesis of gastric mucinous adenocarcinoma and signet-ring cell carcinoma (P = 0.021, OR = 2.882, 95% CI = 1.173–7.084). We examined the expression of STARD3 in 243 tumor tissues out of the 311 GC patients and 20 adjacent normal gastric tissues using immumohistochemical (IHC) analysis and tissue microarrays (TMA). The expression of STARD3 was observed in the gastric parietal cells and in gastric tumor tissues and significantly correlated with gender (P = 0.004), alcohol drinking (P < 0.001), tumor location (P = 0.007), histological type (P = 0.005) and differentiation (P = 0.023) in GC. We concluded that the combined effect of haplotype CCCT of STARD3 might affect GC susceptibility. STARD3 expression might be related to the tumorigenesis of GC in the Chinese population. 相似文献
59.
Leonardo G. Pileggi Natália Rossi Ingo S. Wehrtmann Fernando L. Mantelatto 《ZooKeys》2014,(457):109-131
The closure of the Isthmus of Panama (about 3.1 million years ago) separated previously continuous populations and created two groups of extant species, which live now in the Pacific and Atlantic drainage systems. This relatively recent event was a trigger to diversification of various species in the Neotropics, nonetheless there are exemplars that do not show sufficient morphologic variability to separate them by traditional morphological tools. About 60 years ago, some freshwater decapod species with high morphological similarity were separate by previous researchers, based on geographical distribution, in Pacific and Atlantic and considered as “sister species”. However, the complete isolation of these prawns by this geographical barrier is questionable, and it has generated doubts about the status of the following transisthmian pairs of sibling species: Macrobrachium
occidentale × Macrobrachium
heterochirus, Macrobrachium
americanum × Macrobrachium
carcinus, Macrobrachium
digueti × Macrobrachium
olfersii, Macrobrachium
hancocki × Macrobrachium
crenulatum, Macrobrachium
tenellum × Macrobrachium
acanthurus and Macrobrachium
panamense × Macrobrachium
amazonicum. Here we evaluated the relation among these pairs of sibling species in a molecular phylogenetic context. We generated 95 new sequences: 26 sequences of 16S rDNA, 25 of COI mtDNA and 44 of 18S nDNA. In total, 181 sequences were analyzed by maximum likelihood phylogenetic method, including 12 Macrobrachium transisthmian species, as well as seven other American Macrobrachium species, and two other palaemonids. Our analysis corroborated the morphological proximity of the sibling species. Despite the high degree of morphological similarities and considerable genetic diversification encountered among the transisthmian sister species, our data support the conclusion that all species included in sibling groups studied herein are valid taxonomic entities, but not all pairs of siblings form natural groups. 相似文献
60.
Three species of the genus Xenocerogria Merkl, 2007 have been recorded in China, Xenocerogria
feai (Borchmann, 1911), Xenocerogria
ignota (Borchmann, 1941) and Xenocerogria
ruficollis (Borchmann, 1912). Xenocera
xanthisma Chen, 2002 is proposed as a junior synonym of Xenocerogria
ruficollis. Lectotype of Xenocerogria
ignota is designated, and the species is transferred to the genus Lagria Fabricius, 1775. New Chinese province records of Xenocerogria
ruficollis are provided. 相似文献