The Dynamic Effects of Perceptions of Dread Risk and Unknown Risk on SNS Sharing Behavior During Emerging Infectious Disease Events: Do Crisis Stages Matter?

In response to the increasing prevalence of emerging infectious disease (EID) threats, individuals are turning to social media platforms to share relevant information in ever greater numbers. In this study, we examine whether risk perceptions related to user-generated content have dynamic impacts on social networking site (SNS) sharing behavior in different crisis stages. To answer this question, we applied psychometric analysis to evaluate how dread risk and unknown risk can characterize EID threats. Drawing broadly on the literature of risk perceptions, self-perception theory, and crisis stages, we relied on microblogs collected from Sina Weibo, utilizing the vector autoregression model to analyze dynamic relationships. We found that perceptions of dread risk have a dominant and immediate impact on SNS sharing behavior in the buildup, breakout, and termination stages of EID events. Perceptions of unknown risk have a dominant and persistent impact on sharing behavior in the abatement stage. The joint effect of these two types of risk perception reveal an antagonism impact on SNS sharing behavior, and perceptions of dread- and unknown risk have interaction effects from the buildup to termination stages of EID events. To check robustness, we analyzed keywords related to perceptions of dread- and unknown risk. The results of this study support the empirical application of Slovic’s risk perception framework for understanding the characteristics of EID threats and provide a picture of how perceptions of dread- and unknown risk exert differential time-varying effects on SNS sharing behavior during EID events. We also discuss theoretical and practical implications for the crisis management of EID threats. This study is among the first that uses user-generated content in social media to investigate dynamic risk perceptions and their relationship to SNS sharing behavior, which may help provide a basis for timely and efficient risk communication

Photoluminescent Cationic Carbon Dots as efficient Non-Viral Delivery of Plasmid SOX9 and Chondrogenesis of Fibroblasts

With the increasing demand for higher gene carrier performance, a multifunctional vector could immensely simplify gene delivery for disease treatment; nevertheless, the current non- viral vectors lack self-tracking ability. Here, a type of novel, dual-functional cationic carbon dots (CDs), produced through one-step, microwave-assisted pyrolysis of arginine and glucose, have been utilized as both a self-imaging agent and a non-viral gene vector for chondrogenesis from fibroblasts. The cationic CDs could condense the model gene plasmid SOX9 (pSOX9) to form ultra-small (10–30 nm) nanoparticles which possessed several favorable properties, including high solubility, tunable fluorescence, high yield, low cytotoxicity and outstanding biocompatibility. The MTT assay indicated that CDs/pSOX9 nanoparticles had little cytotoxicity against mouse embryonic fibroblasts (MEFs) compared to Lipofectamine2000 and PEI (25 kDa). Importantly, the CDs/pSOX9 nanoparticles with tunable fluorescence not only enabled the intracellular tracking of the nanoparticles, but also could successfully deliver the pSOX9 into MEFs with significantly high efficiency. Furthermore, the CDs/pSOX9 nanoparticles-mediated transfection of MEFs showed obvious chondrogenic differentiation. Altogether, these findings demonstrated that the CDs prepared in this study could serve as a paradigmatic example of the dual-functional reagent for both self-imaging and effective non-viral gene delivery

Exosomes Derived From Bone Mesenchymal Stem Cells Ameliorate Early Inflammatory Responses Following Traumatic Brain Injury

Traumatic brain injury (TBI) is a leading cause of mortality and disability worldwide. Although treatment guidelines have been developed, no best treatment option or medicine for this condition exists. Recently, mesenchymal stem cells (MSCs)-derived exosomes have shown lots of promise for the treatment of brain disorders, with some results highlighting the neuroprotective effects through neurogenesis and angiogenesis after TBI. However, studies focusing on the role of exosomes in the early stages of neuroinflammation post-TBI are not sufficient. In this study, we investigated the role of bone mesenchymal stem cells (BMSCs)-exosomes in attenuating neuroinflammation at an early stage post-TBI and explored the potential regulatory neuroprotective mechanism. We administered 30 μg protein of BMSCs-exosomes or an equal volume of phosphate-buffered saline (PBS) via the retro-orbital route into C57BL/6 male mice 15 min after controlled cortical impact (CCI)-induced TBI. The results showed that the administration of BMSCs-exosomes reduced the lesion size and improved the neurobehavioral performance assessed by modified Neurological Severity Score (mNSS) and rotarod test. In addition, BMSCs-exosomes inhibited the expression of proapoptosis protein Bcl-2-associated X protein (BAX) and proinflammation cytokines, tumor necrosis factor-α (TNF-α) and interleukin (IL)-1β, while enhancing the expression of the anti-apoptosis protein B-cell lymphoma 2 (BCL-2). Furthermore, BMSCs-exosomes modulated microglia/macrophage polarization by downregulating the expression of inducible nitric oxide synthase (INOS) and upregulating the expression of clusters of differentiation 206 (CD206) and arginase-1 (Arg1). In summary, our result shows that BMSCs-exosomes serve a neuroprotective function by inhibiting early neuroinflammation in TBI mice through modulating the polarization of microglia/macrophages. Further research into this may serve as a potential therapeutic strategy for the future treatment of TBI

Lymphangiogenesis Is Required for Pancreatic Islet Inflammation and Diabetes

Lymphangiogenesis is a common phenomenon observed during inflammation and engraftment of transplants, but its precise role in the immune response and underlying mechanisms of regulation remain poorly defined. Here we showed that in response to injury and autoimmunity, lymphangiogenesis occurred around islets and played a key role in the islet inflammation in mice. Vascular endothelial growth factors receptor 3 (VEGFR3) is specifically involved in lymphangiogenesis, and blockade of VEGFR3 potently inhibited lymphangiogenesis in both islets and the draining LN during multiple low-dose streptozotocin (MLDS) induced autoimmune insulitis, which resulted in less T cell infiltration, preservation of islets and prevention of the onset of diabetes. In addition to their well-known conduit function, lymphatic endothelial cells (LEC) also produced chemokines in response to inflammation. These LEC attracted two distinct CX3CR1hi and LYVE-1+ macrophage subsets to the inflamed islets and CX3CR1hi cells were influenced by LEC to differentiate into LYVE-1+ cells closely associated with lymphatic vessels. These observations indicate a linkage among lymphangiogenesis and myeloid cell inflammation during insulitis. Thus, inhibition of lymphangiogenesis holds potential for treating insulitis and autoimmune diabetes

W-Band Millimeter-Wave Vector Signal Generation Based on Precoding-Assisted Random Photonic Frequency Tripling Scheme Enabled by Phase Modulator

We propose W-band photonic millimeter-wave (mm-wave) vector signal generation employing a precoding-assisted random frequency tripling scheme enabled by a single phase modulator cascaded with a wavelength selective switch (WSS). The selected two optical subcarriers from the phase modulator output by the WSS can have several different kinds of combinations with asymmetrical orders, such as (−3, 0), (−2, 1), (−1, 2), and (0, 3). Employing our proposed precoding-assisted random frequency tripling scheme, we experimentally demonstrate 1/2-Gbd 81-GHz quadrature-phase-shift-keying (QPSK) mm-wave vector signal generation and its wireless delivery over 0.5-m air space distance. We also experimentally demonstrate that the generated mm-wave vector signal based on the minus second-order (−2nd) and first-order (1st) subcarriers, which is equivalent to that based on the minus first-order (−1st) and second-order (2nd) subcarriers, has a better bit-error-ratio (BER) performance than that based on the minus third-order (−3rd) and central (0th) subcarriers, which is equivalent to that based on the 0th and third-order (−3rd) subcarriers, when the phase modulator has a relatively small driving radio-frequency (RF) voltage, whereas an opposite result occurs when the phase modulator has a relatively large driving RF voltage, which is consistent with both our theoretical analysis and numerical simulation

OKC-enabled online knowledge integration: role of group heterogeneity and group interaction process

Purpose: Online knowledge integration has been an important concern of the online knowledge community as it can lead to various positive outcomes of online knowledge coproduction. This paper identifies online knowledge integration factors by considering group heterogeneity and group interaction process. Design/methodology/approach: Based on the categorization-elaboration model (CEM) and interactive team cognition (ITC) theory, a research model that reflects the antecedent's factors and mediating factors of online knowledge integration was developed and empirically examined based on data collected from 2,339,836 data extracted from Wikipedia. Findings: Group interaction process plays an essential mediator role in online knowledge integration. Group knowledge heterogeneity negatively influences online knowledge integration and group experience heterogeneity positively, and they both positively promote online knowledge integration through group interaction process with different paths. Research limitations: Our research concerns the OKC context in one setting (Wikipedia). We expect that the results will generalize to other OKC platforms. Practical implications: The findings of the study could assist the online knowledge community's organizers to understand the motivational mechanisms of online knowledge integration. Group interaction process could be regarded as the key role to promote group wisdom and maintain group independence. Social implications: We advance the understanding of the online knowledge integration and gain a richer understanding of the importance of group interaction independence for online knowledge integration based on the agreement of group wisdom. It suggested keeping group interaction independence is an important aspect for highly online knowledge integration among heterogeneity groups. Originality/value: This study extends CEM and ITC theory to the domain of knowledge integration context and finds the mechanism between group heterogeneity and online knowledge integration by introducing the group interaction process. © 2020, Emerald Publishing Limited

Structural characterization and hypolipidemic activities of purified stigma maydis polysaccharides

This study aimed to investigate structural features and antihyperlipidemic effects of the stigma maydis polysaccharide, termed SMP‐1. This polysaccharide was composed of D‐mannose, L‐rhamnose, D‐glucose, D‐galactose, L‐arabinose, D‐xylose, and D‐galacturonic acid, with a molar ratio of 1.00:0.21:1.41:1.44:0.70:0.44:0.56. The SMP‐1 was mainly bonded by (1 → 6) and (1 → 3) linkages, with various monosaccharides being evenly distributed in the main and side chains. Moreover, SMP‐1 had neither triple‐helical structure nor molecular aggregation. Importantly, the SMP‐1 could effectively bind the bile acids in vitro and significantly lower the total cholesterol, triglyceride, low‐density lipoprotein cholesterol levels, and moderately increase the high‐density lipoprotein cholesterol level in poloxamer 407‐induced hyperlipidemic mice. Moreover, pretreatment with SMP‐1 (≥300 mg/kg) could remarkably reduce fat accumulation and restore hepatocyte morphology in the liver of hyperlipidemic mice. Altogether, these findings indicated that SMP‐1 could be developed as a safe and effective food supplement for preventing and treating hyperlipidemic disorders

Remodeling of the ribosomal quality control and integrated stress response by viral ubiquitin deconjugases

The strategies adopted by viruses to reprogram the translation and protein quality control machinery and promote infection are poorly understood. Here, we report that the viral ubiquitin deconjugase (vDUB)—encoded in the large tegument protein of Epstein-Barr virus (EBV BPLF1)—regulates the ribosomal quality control (RQC) and integrated stress responses (ISR). The vDUB participates in protein complexes that include the RQC ubiquitin ligases ZNF598 and LTN1. Upon ribosomal stalling, the vDUB counteracts the ubiquitination of the 40 S particle and inhibits the degradation of translation-stalled polypeptides by the proteasome. Impairment of the RQC correlates with the readthrough of stall-inducing mRNAs and with activation of a GCN2-dependent ISR that redirects translation towards upstream open reading frames (uORFs)- and internal ribosome entry sites (IRES)-containing transcripts. Physiological levels of active BPLF1 promote the translation of the EBV Nuclear Antigen (EBNA)1 mRNA in productively infected cells and enhance the release of progeny virus, pointing to a pivotal role of the vDUB in the translation reprogramming that enables efficient virus production.</p