36 research outputs found

    Ghrelin attenuates avascular necrosis of the femoral head induced by steroids in rabbits

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    Purpose: Ghrelin is an endogenous ligand for growth hormone secretagogue receptor. The current study was aimed at examining the effect of ghrelin on avascular necrosis of the femoral head (ANFH) induced by steroids in a rabbit model and also exploring the underlying mechanism. Methods: Experimental rabbits were separated into three groups: Control, Vehicle and Ghrelin. We established a steroid-induced ANFH model in rabbits. Then, MRI scanning and hematoxylin-eosin staining (HE) were conducted to see ANFH. The mRNA levels of Vascular Endothelial Growth Factor (VEGF) and Bone Morphogenetic Protein 2 (BMP-2) were evaluated using real-time qRT-PCR. Results: Rabbits in the Vehicle group showed increased empty bone lacunae, reduced bone trabecula in femoral head; the number of hematopoietic cells in the bone marrow was reduced, whereas number of adipocytes increased with evident fusion phenomenon in comparison with the Control group. All of the changes induced in Vehicle group were attenuated in Ghrelin group. MRI scanning showed obvious necrosis of femoral head in the Vehicle group and less in the Ghrelin group. The mRNA levels of VEGF and BMP-2 were raised in Vehicle group and further enhanced in Ghrelin group. Conclusion: Ghrelin attenuates steroid-induced avascular necrosis in femoral head in rabbit model. A possible mechanism may be through VEGF/BMP-2 axis. Keywords: ANFH, BMP-2, Ghrelin, VEG

    BmILF and I-motif Structure Are Involved in Transcriptional Regulation of \u3cem\u3eBmPOUM2\u3c/em\u3e in \u3cem\u3eBombyx mori\u3c/em\u3e

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    Guanine-rich and cytosine-rich DNA can form four-stranded DNA secondary structures called G-quadruplex (G4) and i-motif, respectively. These structures widely exist in genomes and play important roles in transcription, replication, translation and protection of telomeres. In this study, G4 and i-motif structures were identified in the promoter of the transcription factor gene BmPOUM2, which regulates the expression of the wing disc cuticle protein gene (BmWCP4) during metamorphosis. Disruption of the i-motif structure by base mutation, anti-sense oligonucleotides (ASOs) or inhibitory ligands resulted in significant decrease in the activity of the BmPOUM2 promoter. A novel i-motif binding protein (BmILF) was identified by pull-down experiment. BmILF specifically bound to the i-motif and activated the transcription of BmPOUM2. The promoter activity of BmPOUM2 was enhanced when BmILF was over-expressed and decreased when BmILF was knocked-down by RNA interference. This study for the first time demonstrated that BmILF and the i-motif structure participated in the regulation of gene transcription in insect metamorphosis and provides new insights into the molecular mechanism of the secondary structures in epigenetic regulation of gene transcription

    The relationship between fear of COVID-19 and online aggressive behavior: A moderated mediation model

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    In the midst of COVID-19, fear has run rampant across the globe. In an effort to curb the spread of the virus, the social ecology as we had known it had drastically transitioned to a virtual setting. However, such a transition, while warranted and well-intended, may come with unforeseen consequences. Namely, one’s fear of COVID-19 may more readily manifest in subsequent behaviors in an otherwise incognito virtual social ecology. In the current research, a moderated mediation model examined the mechanisms underlying the relation between fear of COVID-19 and aggressive online behavior among Chinese college students. Utilizing a large sample of Chinese college students (N = 2,799), results indicated that fear of COVID-19 was directly positively related to engagement in online aggressive behavior. Moral disengagement partially mediated the link between fear of COVID-19 and college students’ online aggressive behavior. The degree of family cohesion reported by participants served to buffer against the relation between moral disengagement and online aggressive behavior. The findings, theoretical contributions, and practical implications of the present paper are also discussed

    A General Synthetic Approach for Integrated Nanocatalysts of Metal-Silica@ZIFs

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    Integration of different nanocomponents into a greater assemblage or object for applications poses a significant challenge to materials chemists. At present, it still remains extremely difficult to achieve high monodispersivity for such assembled products. To gain better synthetic controllability, ideally, an integration of this type should be done in a stepwise manner. Herein, we report a versatile stepwise approach for preparation of integrated nanocatalysts of metal-<i>m</i>SiO<sub>2</sub>@ZIFs (metal = Pt, Pd, Ru, Ag, and Pt<sub>53</sub>Ru<sub>47</sub>; <i>m</i>SiO<sub>2</sub> = mesoporous silica; and ZIFs = ZIF-8 and ZIF-67). Starting with uniform solid Stöber silica spheres in submicrometer scale, mesoporous channels with desired length and diameter can be created for silica which serves as a support. With measurements of amino-modification of mesopores and selection of metal precursors applied, subsequently, ultrafine metal nanoparticles (2–5 nm) can be deposited evenly onto the inner walls of silica channels. Resultant metal-<i>m</i>SiO<sub>2</sub> spheres are then modified by a layer of anionic polymer which imparts negative charges around and facilitates coating of ZIF-8 shell and thus formation of metal-<i>m</i>SiO<sub>2</sub>@ZIF-8. Through coordination interaction between polyvinylpyrrolidone (PVP; as surfactant molecules) and unsaturated Zn<sup>2+</sup> ions exposed on the ZIF-8 shell, uniform metal-<i>m</i>SiO<sub>2</sub>@ZIF-8 spheres with desired shape and size can be obtained and simultaneously well-dispersed. Fundamental study and optimization are also carried out, aiming at a greater generality of this synthetic approach. The workability of these catalysts is demonstrated with hydrogenation of different alkenes using as-produced Pd-<i>m</i>SiO<sub>2</sub>@ZIF-8 catalyst. Indeed, reactant-selective hydrogenation is achieved based on different interactions of the alkene molecules with the shell structure of ZIF-8, possibly influencing the flexible gate opening of ZIF-8

    Altered cerebellar functional connectivity with intrinsic connectivity networks in adults with major depressive disorder.

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    BACKGROUND: Numerous studies have demonstrated the higher-order functions of the cerebellum, including emotion regulation and cognitive processing, and have indicated that the cerebellum should therefore be included in the pathophysiological models of major depressive disorder. The aim of this study was to compare the resting-state functional connectivity of the cerebellum in adults with major depression and healthy controls. METHODS: Twenty adults with major depression and 20 gender-, age-, and education-matched controls were investigated using seed-based resting-state functional connectivity magnetic resonance imaging. RESULTS: Compared with the controls, depressed patients showed significantly increased functional connectivity between the cerebellum and the temporal poles. However, significantly reduced cerebellar functional connectivity was observed in the patient group in relation to both the default-mode network, mainly including the ventromedial prefrontal cortex and the posterior cingulate cortex/precuneus, and the executive control network, mainly including the superior frontal cortex and orbitofrontal cortex. Moreover, the Hamilton Depression Rating Scale score was negatively correlated with the functional connectivity between the bilateral Lobule VIIb and the right superior frontal gyrus in depressed patients. CONCLUSIONS: This study demonstrated increased cerebellar coupling with the temporal poles and reduced coupling with the regions in the default-mode and executive control networks in adults with major depression. These differences between patients and controls could be associated with the emotional disturbances and cognitive control function deficits that accompany major depression. Aberrant cerebellar connectivity during major depression may also imply a substantial role for the cerebellum in the pathophysiological models of depression

    Increased cortical-limbic anatomical network connectivity in major depression revealed by diffusion tensor imaging.

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    Magnetic resonance imaging studies have reported significant functional and structural differences between depressed patients and controls. Little attention has been given, however, to the abnormalities in anatomical connectivity in depressed patients. In the present study, we aim to investigate the alterations in connectivity of whole-brain anatomical networks in those suffering from major depression by using machine learning approaches. Brain anatomical networks were extracted from diffusion magnetic resonance images obtained from both 22 first-episode, treatment-naive adults with major depressive disorder and 26 matched healthy controls. Using machine learning approaches, we differentiated depressed patients from healthy controls based on their whole-brain anatomical connectivity patterns and identified the most discriminating features that represent between-group differences. Classification results showed that 91.7% (patients=86.4%, controls=96.2%; permutation test, p<0.0001) of subjects were correctly classified via leave-one-out cross-validation. Moreover, the strengths of all the most discriminating connections were increased in depressed patients relative to the controls, and these connections were primarily located within the cortical-limbic network, especially the frontal-limbic network. These results not only provide initial steps toward the development of neurobiological diagnostic markers for major depressive disorder, but also suggest that abnormal cortical-limbic anatomical networks may contribute to the anatomical basis of emotional dysregulation and cognitive impairments associated with this disease

    The impulsive online shopper: effects of COVID-19 burnout, uncertainty, self-control, and online shopping trust

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    Abstract Consumerism during the COVID-19 pandemic has been characterized by impulsive buying. Using the theoretical lens of uncertainty avoidance and ego-depletion to identify the mediating mechanisms and moderating factors for online impulse buying, we surveyed young consumers across two relevant periods for high consumerism—the week preceding the 2021 Chinese Spring Festival (Study 1; February 4–9, 2021, n = 1495) and the weeks during and after the festival (Study 2; February 12 to March 2, 2021, n = 923). Perception of COVID-19 variant uncertainty was both directly and indirectly (via online shopping trust) positively associated with online impulse buying. COVID-19 burnout was consistently indirectly associated with online impulse buying via self-regulation and self-appraised impulsivity but inconsistently directly associated. Self-regulation was surprisingly positively associated with online impulse buying, possibly reflecting evidence of already depleted resources from prolonged regulatory exertion among high self-regulators. Self-appraised impulsivity negatively interacted with perception of COVID-19 variant uncertainty, suggesting that as trait impulsivity increases, individuals are less incentivized by peripheral drivers of online impulse buying

    Analyzing brain-activation responses to auditory stimuli improves the diagnosis of a disorder of consciousness by non-linear dynamic analysis of the EEG

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    Abstract Although auditory stimuli benefit patients with disorders of consciousness (DOC), the optimal stimulus remains unclear. We explored the most effective electroencephalography (EEG)-tracking method for eliciting brain responses to auditory stimuli and assessed its potential as a neural marker to improve DOC diagnosis. We collected 58 EEG recordings from patients with DOC to evaluate the classification model’s performance and optimal auditory stimulus. Using non-linear dynamic analysis (approximate entropy [ApEn]), we assessed EEG responses to various auditory stimuli (resting state, preferred music, subject’s own name [SON], and familiar music) in 40 patients. The diagnostic performance of the optimal stimulus-induced EEG classification for vegetative state (VS)/unresponsive wakefulness syndrome (UWS) and minimally conscious state (MCS) was compared with the Coma Recovery Scale-Revision in 18 patients using the machine learning cascade forward backpropagation neural network model. Regardless of patient status, preferred music significantly activated the cerebral cortex. Patients in MCS showed increased activity in the prefrontal pole and central, occipital, and temporal cortices, whereas those in VS/UWS showed activity in the prefrontal and anterior temporal lobes. Patients in VS/UWS exhibited the lowest preferred music-induced ApEn differences in the central, middle, and posterior temporal lobes compared with those in MCS. The resting state ApEn value of the prefrontal pole (0.77) distinguished VS/UWS from MCS with 61.11% accuracy. The cascade forward backpropagation neural network tested for ApEn values in the resting state and preferred music-induced ApEn differences achieved an average of 83.33% accuracy in distinguishing VS/UWS from MCS (based on K-fold cross-validation). EEG non-linear analysis quantifies cortical responses in patients with DOC, with preferred music inducing more intense EEG responses than SON and familiar music. Machine learning algorithms combined with auditory stimuli showed strong potential for improving DOC diagnosis. Future studies should explore the optimal multimodal sensory stimuli tailored for individual patients. Trial registration: The study is registered in the Chinese Registry of Clinical Trials (Approval no: KYLL-2023-414, Registration code: ChiCTR2300079310)

    Nanopatterned and self-cleaning glass substrates for solar cell packaging

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    10.1109/ICCIAutom.2011.6356637Proceedings - 2011 2nd International Conference on Control, Instrumentation and Automation, ICCIA 201196-10
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