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排序方式: 共有450条查询结果,搜索用时 31 毫秒
31.
Klaus Schümann Nadia Herbach Christina Kerling Markus Seifert Carine Fillebeen Isabella Prysch Jens Reich Günter Weiss Kostas Pantopoulos 《Journal of trace elements in medicine and biology》2010,24(1):58-66
Hemizygous TNFΔARE/+ mice are a murine model for chronic inflammation. We utilized these animals to study iron-kinetics and corresponding protein expression in an iron-deficient and iron-adequate setting. 59Fe-absorption was determined in ligated duodenal loops in vivo. Whole body distribution of i.v. injected 59Fe was analysed, and the organ specific expression of ferroportin, transferrin receptor-1, hepcidin and duodenal DMT-1 was quantified by real-time PCR and Western blotting.Duodenal 59Fe-lumen-to-body transport was not affected by the genotype. Duodenal 59Fe-retention was increased in TNFΔARE/+ mice, suggesting higher 59Fe-losses with defoliated enterocytes. Iron-deficiency increased duodenal 59Fe-lumen-to-body transport, and higher duodenal 59Fe-tissue retention went along with higher duodenal DMT-1, ferroportin, and liver hepcidin expression. TNFΔARE/+ mice significantly increase their 59Fe-content in inflamed joints and ilea, and correspondingly reduce splenic 59Fe-content. Leukocyte infiltrations in the joints suggest a substantial shift of iron-loaded RES cells to inflamed tissues as the underlying mechanism. This finding was paralleled by increased non-haem iron content in joints and reduced haemoglobin and haematocrit concentrations in TNFΔARE/+ mice.In conclusion, erythropoiesis in inflamed TNFΔARE/+ mice could be iron-limited due to losses with exfoliated iron-loaded enterocytes and/or to increased iron-retention in RES cells that shift from the spleen to inflamed tissues. 相似文献
32.
The authors present an annotated list of rare or otherwise interesting vascular plants collected in the mountains of northern Greece by themselves in 1979 and by Strid and Georgiadou in 1977. The following are apparently new to Greece: Thesium linophyllon L. ssp. montanum (Ehrh. ex. Hoffm.) Čelak., Moehringia pendulo (Waldst. & Kit.) Fenzl, Gypsophila glomerata Pallas ex. Bieb., Dianthus peiraeus Waldst. & Kit. ssp. noeanus (Boiss.) Tutin, Dianthus superbus L., Ranunculus fon–tanus C. Presl, Thlaspi arvense L., Potentilla apennina Ten. ssp. stoianovii Urum. & Jav., Trifolium badium Schreber, Rhamnus pumila Turra, Viola palustris L., Athamanta albanica Alston & Sandwith, Peucedanum oligophyllum ssp. aequiradium (Vandas) Tutin, Vaccinium gaultherioides Bigelow, Galeopsis speciosa Miller, G. bifida Boenn., Melampyrum sylvaticum L., Odontites lutea (L.) Clairv., Sambucus racemosa L., Symphyandra wanneri (Rochel) Heuffel, Galinsoga parviflora Cav., Achillea distans Waldst. & Kit. ex Willd., Centaurea grbavacensis (Rohlena) Stoj. & Acht., C. indurata Janka, Lactuca aurea (Schultz Bip. ex PanČić) Stebbins, Festuca gigantea (L.) Vill., F. pirinica Horvat ex Markgr.–Dannenb., Sparganium minimum (Hartm.) Fries, and Rhynchospora alba (L.) Vahl. 相似文献
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34.
Repanas K Zingler N Layer LE Schumann GG Perrakis A Weichenrieder O 《Nucleic acids research》2007,35(14):4914-4926
The human LINE-1 endonuclease (L1-EN) is the targeting endonuclease encoded by the human LINE-1 (L1) retrotransposon. L1-EN guides the genomic integration of new L1 and Alu elements that presently account for ~28% of the human genome. L1-EN bears considerable technological interest, because its target selectivity may ultimately be engineered to allow the site-specific integration of DNA into defined genomic locations. Based on the crystal structure, we generated L1-EN mutants to analyze and manipulate DNA target site recognition. Crystal structures and their dynamic and functional analysis show entire loop grafts to be feasible, resulting in altered specificity, while individual point mutations do not change the nicking pattern of L1-EN. Structural parameters of the DNA target seem more important for recognition than the nucleotide sequence, and nicking profiles on DNA oligonucleotides in vitro are less well defined than the respective integration site consensus in vivo. This suggests that additional factors other than the DNA nicking specificity of L1-EN contribute to the targeted integration of non-LTR retrotransposons. 相似文献
35.
Douroumis D Fatouros DG Bouropoulos N Papagelis K Tasis D 《International journal of nanomedicine》2007,2(4):761-766
Within the family of nanomaterials, carbon nanotubes (CNTs) have emerged as a new efficient scaffold for studying molecular interactions at interfaces. Poor dispersability of CNTs in any solvent presents a considerable drawback for the development of novel functional composite structures. Previous studies have demonstrated that the solubility of CNTs can be greatly enhanced by employing appropriate surfactants, some of them being biological molecules. In this work, we study the noncovalent wrapping of lipid chains onto the graphitic surface of single-walled material (SWCNTs) by electron microscopy and Raman spectroscopy. Stable and homogenous aqueous suspensions of SWCNTs in the presence of lipids have been prepared, whereas their electrophoretic mobility was confirmed by zeta-potential measurements. Raman measurements revealed that smaller diameter SWCNTs are preferentially dispersed by lipid molecules in the aqueous supernatant part of the prepared suspension. 相似文献
36.
The small Tims are chaperones that facilitate insertion of hydrophobic precursors into the inner mitochondrial membrane. We purified Tim12 and found it forms dimers that bind to Tim9. In this interaction, Tim12 undergoes structural changes that may be important for transport of its substrates in the mitochondrial carrier import pathway. 相似文献
37.
De Savi C Morley AD Ting A Nash I Karabelas K Wood CM James M Norris SJ Karoutchi G Rankine N Hamlin G Macfaul PA Ryan D Baker SV Hargreaves D Gerhardt S 《Bioorganic & medicinal chemistry letters》2011,21(14):4215-4219
Directed screening has identified a novel series of MMP13 inhibitors that possess good levels of activity whilst possessing excellent selectivity over related MMPs. The binding mode of the series has been solved by co-crystallisation and demonstrates an interesting mode of inhibition without interaction with the catalytic zinc atom. 相似文献
38.
From research to implementation: Nature conservation in the Eastern Rhodopes mountains (Greece and Bulgaria), European Green Belt 总被引:2,自引:0,他引:2
Stefan Schindler Nuno Curado Stoyan C. Nikolov Elzbieta Kret Beatriz Cárcamo Giorgos Catsadorakis Kostas Poirazidis Thomas Wrbka Vassiliki Kati 《Journal for Nature Conservation》2011,19(4):193-201
Nature conservation should ideally build on the scientific recommendations that are concluded from applied conservation research, as well as on monitoring schemes that evaluate the effectiveness of recommendations. We considered as a case study a system of six protected areas located in the Eastern Rhodopes mountains in the southern part of the European Green Belt (EGB). To investigate nature conservation effectiveness, we reviewed 196 articles from scientific journals and books, eight doctoral and master theses, and 39 scientific reports regarding the Greek (one protected area, 428 km2) and the Bulgarian (five protected areas, 904 km2) part of the study area. We extracted 743 conservation recommendations, and through questionnaires completed by 10 local experts, we found that 74% of the recommendations were familiar for the experts. In the Greek (GR) and the Bulgarian part (BG) only 52% and 16%, respectively, of the recommendations were implemented, and only 15% (GR) and 3.1% (BG) were implemented and evaluated regarding their effectiveness. According to the experts, the main reasons for non-implementation and non-evaluation were absence or incompetence of the responsible authorities. Some recommendations obtained a remarkable low rate of implementation, such as those regarding agriculture and livestock rearing practices (GR: 29%, BG: 16%) or mammal conservation (GR: 0%, BG: 16%). Some other recommendations obtained rather high rates at least for Greece, such as tourism and environmental education (GR: 57%, BG: 42%) and bird conservation (GR: 57%, BG: 11%). We found that researchers and conservation managers at both sides of the Greek-Bulgarian border face similar implementation problems, related often to the lack of political will for nature conservation and establishment of competent authorities. The role of the EGB is crucial in enhancing the established cross-border collaborations between stakeholders involved in nature conservation. 相似文献
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Interacting in the peripersonal space requires coordinated arm and eye movements to visual targets in depth. In primates, the medial posterior parietal cortex (PPC) represents a crucial node in the process of visual-to-motor signal transformations. The medial PPC area V6A is a key region engaged in the control of these processes because it jointly processes visual information, eye position and arm movement related signals. However, to date, there is no evidence in the medial PPC of spatial encoding in three dimensions. Here, using single neuron recordings in behaving macaques, we studied the neural signals related to binocular eye position in a task that required the monkeys to perform saccades and fixate targets at different locations in peripersonal and extrapersonal space. A significant proportion of neurons were modulated by both gaze direction and depth, i.e., by the location of the foveated target in 3D space. The population activity of these neurons displayed a strong preference for peripersonal space in a time interval around the saccade that preceded fixation and during fixation as well. This preference for targets within reaching distance during both target capturing and fixation suggests that binocular eye position signals are implemented functionally in V6A to support its role in reaching and grasping. 相似文献