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91.
In the past few years, gallium‐68 has demonstrated significant potential as a radioisotope for positron emission tomography (PET), and the optimization of chelators for gallium coordination is a major goal in the development of radiopharmaceuticals. Methylaminotriazacyclononane trimethylphosphinate (MA‐NOTMP), a new C‐functionalized triazacyclononane derivative with phosphinate pendant arms, presents excellent coordination properties for 68Ga (low ligand concentration, labelling at low pH even at room temperature). A “ready‐to‐be‐grafted” bifunctional chelating agent (p‐NCS‐Bz‐MA‐NOTMP) was prepared to allow 68Ga labelling of sensitive biological vectors. Conjugation to a bombesin(7–14) derivative was performed, and preliminary in vitro experiments demonstrated the potential of MA‐NOTMP in the development of radiopharmaceuticals. This new chelator is therefore of major interest for labelling sensitive biomolecules, and further in vivo experiments will soon be performed.  相似文献   
92.
93.
In this study, unidirectional poly(ether ether ketone)/carbon fiber (CF) composite sheets were elaborated with unsized, epoxy‐sized, and thermoplastic‐sized CFs by hot‐press molding. The thermoplastic sizings that we used were poly(ether imide) (PEI) and poly(ether ketone ketone) oligomer aqueous dispersions. Scanning electron microscopy observation of the composites freeze fractures showed that unlike unsized or epoxy‐sized CFs, the thermoplastic sizings improved the interaction between the fibers and the matrix. A comparative study of the mechanical relaxations by dynamic mechanical analysis was carried out on the different composites before and after immersion in kerosene. At low temperature, the PEI sizing had a significant influence on the β relaxation, particularly after kerosene immersion. The thermoplastic sizings did not modify the glass‐transition temperature but improved the kerosene resistance on the composites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42550.  相似文献   
94.
Fire hazard in nuclear power plants (NPPs) is particularly often investigated as potential cause of safety equipment failure and confinement loss. Many fire events recorded in NPPs involve electric cables, widely used throughout facilities. IRSN is developing the CALIF3S/ISIS computational fluid dynamics software devoted to fire simulation in large‐scale confined and mechanically ventilated compartments. This paper presents two aspects of the CALIF3S/ISIS code ability to simulate fires. The first one concerns vertical and horizontal spreading of a cable tray fire in open atmosphere using an approach based on the FLASH‐CAT cable fire spread model. Resorting to the suitable parameters of the FLASH‐CAT model based on video fire analyses of tests enables to properly compute the heat release rate of the fire. The second aspect concerns the ability to simulate the evolution and consequences of fires in confined and mechanically ventilated compartments. For these cases, the heat release rate measured during the corresponding experiment is used as input data for the calculations. The predicted evolutions of pressure or gas temperatures are in relatively good accordance with the experiments. The major discrepancy concerns gas concentrations in the fire room which is attributed to a lack of information about the properties of the fuel material.  相似文献   
95.
The structurally unique “fleximer” nucleosides were originally designed to investigate how flexibility in a nucleobase could potentially affect receptor–ligand recognition and function. Recently they have been shown to have low-to-sub-micromolar levels of activity against a number of viruses, including coronaviruses, filoviruses, and flaviviruses. However, the synthesis of distal fleximers in particular has thus far been quite tedious and low yielding. As a potential solution to this issue, a series of proximal fleximer bases (flex-bases) has been successfully coupled to both ribose and 2′-deoxyribose sugars by using the N-deoxyribosyltransferase II of Lactobacillus leichmannii (LlNDT) and Escherichia coli purine nucleoside phosphorylase (PNP). To explore the range of this facile approach, transglycosylation experiments on a thieno-expanded tricyclic heterocyclic base, as well as several distal and proximal flex-bases were performed to determine whether the corresponding fleximer nucleosides could be obtained in this fashion, thus potentially significantly shortening the route to these biologically significant compounds. The results of those studies are reported herein.  相似文献   
96.
Laminopathies are a clinically heterogeneous group of disorders caused by mutations in the LMNA gene, which encodes the nuclear envelope proteins lamins A and C. The most frequent diseases associated with LMNA mutations are characterized by skeletal and cardiac involvement, and include autosomal dominant Emery–Dreifuss muscular dystrophy (EDMD), limb-girdle muscular dystrophy type 1B, and LMNA-related congenital muscular dystrophy (LMNA-CMD). Although the exact pathophysiological mechanisms responsible for LMNA-CMD are not yet understood, severe contracture and muscle atrophy suggest that mutations may impair skeletal muscle growth. Using human muscle stem cells (MuSCs) carrying LMNA-CMD mutations, we observe impaired myogenic fusion with disorganized cadherin/β catenin adhesion complexes. We show that skeletal muscle from Lmna-CMD mice is unable to hypertrophy in response to functional overload, due to defective fusion of activated MuSCs, defective protein synthesis and defective remodeling of the neuromuscular junction. Moreover, stretched myotubes and overloaded muscle fibers with LMNA-CMD mutations display aberrant mechanical regulation of the yes-associated protein (YAP). We also observe defects in MuSC activation and YAP signaling in muscle biopsies from LMNA-CMD patients. These phenotypes are not recapitulated in closely related but less severe EDMD models. In conclusion, combining studies in vitro, in vivo, and patient samples, we find that LMNA-CMD mutations interfere with mechanosignaling pathways in skeletal muscle, implicating A-type lamins in the regulation of skeletal muscle growth.  相似文献   
97.
In recent years, a role for epigenetic modifications in the pathophysiology of disease has received significant attention. Many studies are now beginning to explore the gene–environment interactions, which may mediate early-life exposure to risk factors, such as nutritional deficiencies and later development of behavioral problems in children and adults. In this paper, we review the current literature on the role of epigenetics in the development of psychopathology, with a specific focus on the potential for epigenetic modifications to link nutrition and brain development. We propose a conceptual framework whereby epigenetic modifications (e.g., DNA methylation) mediate the link between micro- and macro-nutrient deficiency early in life and brain dysfunction (e.g., structural aberration, neurotransmitter perturbation), which has been linked to development of behavior problems later on in life.  相似文献   
98.
99.
Varying the formulation and processing conditions of polymer blends allows the design of materials with a large range of morphologies. Active materials embedding active compounds in a devoted phase are promising applications of such blends, offering possible various transport properties. In this study, 13 poly(butylene succinate‐co‐butylene adipate) (PBSA)/polyethylene oxide (PEO) blends were extruded in a slit die. Their morphologies were characterized by water extraction (selective PEO dissolution), FTIR spectroscopy, and differential scanning calorimetry. Transport properties were assessed by water vapor permeation and fluorescein release as model migrant. Indeed, the desorption in water of fluorescein (previously entrapped in PEO) was monitored to preliminary investigate the release properties of these materials: two morphologies were obtained (i) pseudo multilayer films made of PEO‐rich layer/PBSA‐rich layer/PEO‐rich layer and (ii) PEO nodules dispersed in the PBSA‐rich matrix for the highest PBSA contents. The first systems were erodible ones with an uncontrolled fast delivery by PEO dissolution whereas the second ones showed a controlled release by permeation through the PBSA matrix from PEO nodules. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42874.  相似文献   
100.
This study looks at the perceived quality of light‐emitting diode (LED)‐based lighting of various colors. The objective was to find out whether LEDs could provide better (i.e., more relevant and acceptable) lighting than that which is obtained with standard halogen or fluorescent sources. The perception of objects was assessed under different lighting schemes. Subjects were invited to add red, cyan and/or amber to white LED‐based light to match the halogen and fluorescence rendering on specific targets: a color chart and a painting. They were also asked to rate the difference between the two, and to express their preference. The results obtained for the perception of LED‐based lighting were quite positive. Color blendings of LED light were found to provide illuminated situations similar to halogens or fluorescent sources. These blendings were well accepted, and indeed often preferred, although the color rendering index (CRI) was always low. This indicates that the CRI as it stands is inadequate to characterize the color rendering of solid‐state light sources, and needs to be updated. LED‐based lighting systems seem to have considerable potential for use in shops and display units, where they may well outperform existing lighting systems. © 2009 Wiley Periodicals, Inc. Col Res Appl, 34, 310–320, 2009  相似文献   
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