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排序方式: 共有622条查询结果,搜索用时 15 毫秒
1.
Enzo Ottaviani Antonella Franchini Paolo Fontanili 《Cellular and molecular neurobiology》1992,12(5):455-462
1. Using an immunocytochemical procedure a wide range of immunoreactive vertebrate bioactive peptides (BAPs) has been found in hemocytes of Viviparus ater: bombesin, calcitonin, CCK-8, CCK-39, GH, glucagon, insulin, oxytocin, neurotensin, secretin, serotonin, somatostatin, substance P, vasopressin, and VIP. 2. No immunostaining was observed for antigastrin and antithyroglobulin antibodies. 3. The presence of BAP-like molecules in hemocytes suggests a correlation between hemocyte and APUD cells and is evidence of a relationship between the neuroendocrine and the immune systems. 相似文献
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From ligulate flowers of Matricaria chamomilla was isolated a mixture of apigenin 7-O-β-glucoside diacetates, which was shown to be based on (2″, 3″)- and (3″, 4″)-diacetates. 相似文献
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Fragile X related protein 1 isoforms differentially modulate the affinity of fragile X mental retardation protein for G-quartet RNA structure 总被引:2,自引:2,他引:2
Bechara E Davidovic L Melko M Bensaid M Tremblay S Grosgeorge J Khandjian EW Lalli E Bardoni B 《Nucleic acids research》2007,35(1):299-306
Fragile X syndrome, the most frequent form of inherited mental retardation, is due to the absence of expression of the Fragile X Mental Retardation Protein (FMRP), an RNA binding protein with high specificity for G-quartet RNA structure. FMRP is involved in several steps of mRNA metabolism: nucleocytoplasmic trafficking, translational control and transport along dendrites in neurons. Fragile X Related Protein 1 (FXR1P), a homologue and interactor of FMRP, has been postulated to have a function similar to FMRP, leading to the hypothesis that it can compensate for the absence of FMRP in Fragile X patients. Here we analyze the ability of three isoforms of FXR1P, expressed in different tissues, to bind G-quartet RNA structure specifically. Only the longest FXR1P isoform was found to be able to bind specifically the G-quartet RNA, albeit with a lower affinity as compared to FMRP, whereas the other two isoforms negatively regulate the affinity of FMRP for G-quartet RNA. This result is important to decipher the molecular basis of fragile X syndrome, through the understanding of FMRP action in the context of its multimolecular complex in different tissues. In addition, we show that the action of FXR1P is synergistic rather than compensatory for FMRP function. 相似文献
5.
Pierangela Giustetto Miriam Filippi Mauro Castano Enzo Terreno 《Journal of visualized experiments : JoVE》2015,(97)
Photoacoustics and high frequency ultrasound stands out as powerful tools for neurobiological applications enabling high-resolution imaging on the central nervous system of small animals. However, transdermal and transcranial neuroimaging is frequently affected by low sensitivity, image aberrations and loss of space resolution, requiring scalp or even skull removal before imaging. To overcome this challenge, a new protocol is presented to gain significant insights in brain hemodynamics by photoacoustic and high-frequency ultrasounds imaging with the animal skin and skull intact. The procedure relies on the passage of ultrasound (US) waves and laser directly through the fissures that are naturally present on the animal cranium. By juxtaposing the imaging transducer device exactly in correspondence to these selected areas where the skull has a reduced thickness or is totally absent, one can acquire high quality deep images and explore internal brain regions that are usually difficult to anatomically or functionally describe without an invasive approach. By applying this experimental procedure, significant data can be collected in both sonic and optoacoustic modalities, enabling to image the parenchymal and the vascular anatomy far below the head surface. Deep brain features such as parenchymal convolutions and fissures separating the lobes were clearly visible. Moreover, the configuration of large and small blood vessels was imaged at several millimeters of depth, and precise information were collected about blood fluxes, vascular stream velocities and the hemoglobin chemical state. This repertoire of data could be crucial in several research contests, ranging from brain vascular disease studies to experimental techniques involving the systemic administration of exogenous chemicals or other objects endowed with imaging contrast enhancement properties. In conclusion, thanks to the presented protocol, the US and PA techniques become an attractive noninvasive performance-competitive means for cortical and internal brain imaging, retaining a significant potential in many neurologic fields. 相似文献
6.
Angelo F. Benedetto Philip J. Squattrito Fabrizio Adani Enzo Montoneri 《Inorganica chimica acta》1997,260(2):1145-216
A study of the salts of 4-fluoro-3-sulfobenzylphosphonic acid has resulted in the synthesis of two new compounds with unusual layered structures. The crystal structures of these salts and the parent acid have been determined by single crystal X-ray methods. Crystal data: 4-F-3-SO3H-C6H3CH2PO3H2·H2O: triclinic, space group
for 1519 observations (l>3σ(l)) and 182 variables; [Ni(NH3)2(H2O)4]3(4-F-3-SO3-C6H3-CH2PO3)2·4H2O: triclinic, space group
for 2689 observations (l>3σ(I)) and 511 variables: Na3(4-F-3-SO3-C6H3CH2PO3)- 8.5H2O: monoclinic, C2/c, Z = 8, A = 25.636(4), B = 6.218(4), C = 24.136(2) Å, β = 98.33(1)°, V = 3807(3) Å3, R(F) = 0.047 for 2262 observations (I>2;3σ(I)) and 254 variables. The parent acid monohydrate crystallizes in layers with the acidic groups directed to the faces of the layer. The water molecules are in between the layers hydrogen-bonded to the sulfonate oxygen atoms. The nickel salt contains three independent cations, each of which is hexacoordinated to a mixture of water and ammonia molecules. Thus, there is no direct coordination of the nickel by either the sulfonate or phosphonate oxygen atoms. The structure has alternating layers, the first formed by the anions and one of the nickel complexes, and the second by the other two complexes and the free water molecules. The sodium salt also has the anions arranged in layers but with an interpenetrating three-dimensional network of ionic and hydrogen bonds involving the cations and water molecules. The sodium ions are coordinated to a mixture of sulfonate oxygen atoms and bridging water molecules in irregular six-fold environments. These structures are discussed in terms of the coordination behavior of the difunctional anions in the context of known monofunctional phosphonate and sulfonate compounds. 相似文献
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Concetta Compagno Aldo Tura Bianca Maria Ranzi Enzo Martegani 《Applied microbiology and biotechnology》1992,36(4):535-537
Summary One of the methods commonly used for manufacturing fructose 1,6-diphosphate is based on the enzymatic phosphorylation of glucose with inorganic phosphate using permeabilized brewer's yeast cells. Our results demonstrate that a substantial improvement in the yield of bioconversion can be achieved using fed-batch-grown Saccharomyces cerevisiae cells. Under an appropriate glucose and phosphate to cell ratio the efficiency of bioconversion reaches 70% of the theoretical value.
Offprint requests to: C. Compagno 相似文献
10.
Syatkin Sergey P. Neborak Ekaterina V. Khlebnikov Andrei I. Komarova Marina V. Shevkun Natalia A. Kravtsov Eduard G. Blagonravov Mikhail L. Agostinelli Enzo 《Amino acids》2020,52(2):199-211
Amino Acids - The polyamine (PA) metabolism is involved in cell proliferation and differentiation. Increased cellular PA levels are observed in different types of cancers. Products of PA oxidation... 相似文献