355 research outputs found

    Voxel-based density registration of trabecular bone: a longitudinal HR-pQCT study of postmenopausal women

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    Bone mineral density (BMD) is one of the important parameters used to characterise bone quality. Clinically, the only recommended method - dual X-ray absorptiometry - can only evaluate a two-dimensional areal BMD. Currently, three-dimensional localised BMD information is absent. HR-pQCT enables the assessments of 3D microstructure down to trabecular bone. Therefore, in this study, a voxel-based density registration (VDR) method is proposed to analyse the longitudinal changes of trabecular-bone density distribution. The VDR techniques were evaluated based on a six-month longitudinal study of five postmenopausal women. The time effect on localised changes of trabecular-bone mineral density was visualized and variations between different anatomical regions were quantified for the first time. Different distributions between anatomical regions were found in bone mineral density of trabecular bone (vBMDtrab), with a change of vBMDtrab at medial region (-0.56%) significantly higher than anterior (-1.58%) (p = 0.032). This study indicates that localised density changes might be used as a prior indicator for the effect of aging or other interventions.</p

    Thermo-migration behavior of SAC305 lead-free solder reinforced with fullerene nanoparticles

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    In this work, SAC305 lead-free solder reinforced with 0.1 wt. % fullerene nanoparticles was prepared using a powder metallurgy method. A lab-made setup and a corresponding Cu/solder/Cu sample for thermo-migration (TM) test were designed and implemented. The feasibility of this setup for TM stressing was further verified with experimental and simulation methods; a temperature gradient in a solder seam was calculated as 1070 K/cm. Microstructural evolution and mechanical properties of both plain and composite solder alloys were then studied under the condition of TM stressing. It was shown that compared to unreinforced SAC305 solder, the process of diffusion of Cu atoms in the composite solder seam was remarkably suppressed. After the TM test for 600 h, Cu/solder interfaces in the composite solder seam were more stable and the inner structure remained more intact. Moreover, the addition of fullerene reinforcement can considerably affect a distribution of Cu6Sn5 formed as a result of dissolution of Cu atoms during the TM test. Hardness data across the solder seam were also found notably different because of the elemental redistribution caused by TM

    Phosphomolybdic acid-responsive Pickering emulsions stabilized by ionic liquid functionalized Janus nanosheets

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    <p><b>A</b> Representative photomicrographs of Caspase-3 immunofluorescence staining (400×). <b>B</b> Quantification of Caspase-3 fluorescence intensity in different groups. <b>C</b> Representative Western blot band of Caspase-3 activation in the ischemic cortex at 24 h after reperfusion. <b>D</b> Effect of LBP (40 mg/kg) on the Caspase-3 activation in MCAO mice cortex at 24 h after reperfusion. Data are expressed as mean±SEM (n = 6). <sup>##</sup>P<0.01 vs. sham-operated group; **P<0.01 vs. vehicle group.</p

    Regulatory transparency and citizen support for government decisions: evidence from nuclear power acceptance in China

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    This study examines the effect of transparency as a governance mechanism on citizen support for controversial governmental decisions to public facilities. Building on the government transparency literature, this article argues that regulatory transparency has a double-sided meaning of regulatory enforcement and rule violations. Due to the ambiguity inherent in regulatory performance information, citizens may interpret disclosed information as a reflection of prevalent rule violations and thereby reduce support for relevant public facilities. Furthermore, the negative association between regulatory transparency and citizen support is contingent on citizens’ use of social media. We test these arguments in the nuclear energy regulatory domain using original, nationally representative survey data and an independent environmental regulation transparency index in China. Findings reveal that regulatory transparency reduces citizen support for proposed nuclear power programs. We also find that regulatory transparency is particularly influential for respondents with relatively higher levels of social media usage. These findings highlight the dilemma that governments face when they seek to enhance policy support through transparency in the digital age.</p

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    self-reported data of sex preferenc

    Remodelling of trabecular bone in human distal tibia: A model based on an in-vivo HR-pQCT study

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    An abnormal remodelling process of bones can lead to various bone disorders, such as osteoporosis, making them prone to fracture. Simulations of load-induced remodelling of trabecular bone were used to investigate its response to mechanical signal. However, the role of mechanostat in trabecular-bone remodelling has not yet been investigated in simulations underpinned by a longitudinal in-vivo study in humans. In this work, a finite-element model based on a 6-month longitudinal in-vivo HR-pQCT study was developed and validated to investigate the effect of mechanical stimuli on bone remodelling. The simulated changes in microstructural parameters and density of trabecular bone were compared with respective experimental results. A maximum principal strain (MPS) and a maximum principal strain gradient (∇MPS) were used as mechanical signals to drive a five-stage mechanostat remodelling model, including additional over-strain and damage stages. It was found that the density distribution varied with the studied mechanical signals, along with decreasing with time levels of bone volume fraction BV/TV, trabecular thickness Tb.Th and bone surface area Tb.BS as well as increased trabecular separation Tb.Sp. Among these parameters, BV/TV and Tb.Th together with the bone remodelling parameters from the MPS model demonstrated a significant correlation with the experimental data. The developed model provides a good foundation for further development and investigation of the relationships between mechanical loading and human bone microarchitecture

    Image_1_The Binding Mechanism Between Inositol Phosphate (InsP) and the Jasmonate Receptor Complex: A Computational Study.TIF

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    <p>Jasmonates are critical plant hormones, mediating stress response in plants and regulating plant growth and development. The jasmonate receptor is a multi-component complex, composed of Arabidopsis SKP-LIKE PROTEIN1 (ASK1), CORONATINE INSENSITIVE 1 (COI1), inositol phosphate (InsP), and jasmonate ZIM-domain protein (JAZ). COI1 acts as multi-component signaling hub that binds with each component. InsP is suggested to play important roles in the hormone perception. How InsP binds with COI1 and the structural changes in COI1 upon binding with InsP, JA-Ile, and JAZ are not well understood. In this study, we integrated multiple computational methods, such as molecular docking, molecular dynamics simulations, residue interaction network analysis and binding free energy calculation, to explore the effect of InsP on the dynamic behavior of COI1 and the recognition mechanism of each component of the jasmonate receptor complex. We found that upon binding with InsP, JA-Ile, and JAZ1, the structure of COI1 becomes more compact. The binding of InsP with COI1 stabilizes the conformation of COI1 and promotes the binding between JA-Ile or JAZ1 and COI1. Analysis of the network parameters led to the identification of some hub nodes in this network, including Met88, His118, Arg120, Arg121, Arg346, Tyr382, Arg409, Trp467, and Lys492. The structural and dynamic details will be helpful for understanding the recognition mechanism of each component and the discovery and design of novel jasmonate signaling pathway modulators.</p

    Computational study of the binding mechanism between farnesoid X receptor α and antagonist N-benzyl-N-(3-(tertbutyl)-4-hydroxyphenyl)-2,6-dichloro-4-(dimethylamino) benzamide

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    <p>Farnesoid X receptor α (FXRα) is a bile acid-activated transcription factor, which plays important roles in the regulation of multiple metabolic processes. Development of FXR antagonist has revealed great potential for the treatment of metabolic disorders. The compound N-Benzyl-N-(3-(tertbutyl)-4-hydroxyphenyl)-2,6-dichloro-4-(dimethylamino). Benzamide (NDB) was recently determined as a selective antagonist of FXRα, while the detailed interaction mechanism is not well understood. In this study, the combined computational methods including molecular dynamics simulations, binding free energy calculation, and principal component analysis were utilized to investigate the effect of NDB on the dynamics behaviors and dimerization of FXRα The binding free energy calculation indicated that the protein dimerization increases NDB affinity and the binding of NDB also stabilizes the interaction between two subunits of FXRα. Further decomposition of the overall binding free energies into individual residues identifies several residues significant for NDB binding, including Leu291, Met294, Ala295, His298, Met332, Ser336, Ala452, and Leu455. It also suggests that the interactions of L289(A)–W458(B), W458(A)–L289(B), R459(A)–N461(B), and N461(A)–R459(B) are important for the dimer stabilization. This study provides a molecular basis for the understanding of binding mechanism between antagonist NDB and FXRα and valuable information for the novel FXR modulators design for the treatment of metabolic syndrome.</p

    Identification of Putative Olfactory Genes from the Oriental Fruit Moth <i>Grapholita molesta</i> via an Antennal Transcriptome Analysis

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    <div><p>Background</p><p>The oriental fruit moth, <i>Grapholita molesta</i>, is an extremely important oligophagous pest species of stone and pome fruits throughout the world. As a host-switching species, adult moths, especially females, depend on olfactory cues to a large extent in locating host plants, finding mates, and selecting oviposition sites. The identification of olfactory genes can facilitate investigation on mechanisms for chemical communications.</p><p>Methodology/Principal Finding</p><p>We generated transcriptome of female antennae of <i>G</i>.<i>molesta</i> using the next-generation sequencing technique, and assembled transcripts from RNA-seq reads using Trinity, SOAPdenovo-trans and Abyss-trans assemblers. We identified 124 putative olfactory genes. Among the identified olfactory genes, 118 were novel to this species, including 28 transcripts encoding for odorant binding proteins, 17 chemosensory proteins, 48 odorant receptors, four gustatory receptors, 24 ionotropic receptors, two sensory neuron membrane proteins, and one odor degrading enzyme. The identified genes were further confirmed through semi-quantitative reverse transcription PCR for transcripts coding for 26 OBPs and 17 CSPs. OBP transcripts showed an obvious antenna bias, whereas CSP transcripts were detected in different tissues.</p><p>Conclusion</p><p>Antennal transcriptome data derived from the oriental fruit moth constituted an abundant molecular resource for the identification of genes potentially involved in the olfaction process of the species. This study provides a foundation for future research on the molecules involved in olfactory recognition of this insect pest, and in particular, the feasibility of using semiochemicals to control this pest.</p></div

    Sequences alignment of candidate GmolOBPs.

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    <p>The six conserved cysteine residues were marked with “☆”. As GmolOBP17, 18, 19, 20, 21, 22 and 23 are not intact sequences, those sequences are not included in the multisequence alignment.</p
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