789 research outputs found

    The Chain Flexibility Effects on the Self-assembly of Diblock Copolymer in Thin Film

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    We investigate the effects of chain flexibility on the self-assembly behavior of symmetric diblock copolymers (BCPs) when they are confined as a thin film between two surfaces. Employing worm-like chain (WLC) self-consistent field theory, we study the relative stability of parallel (L_{\parallel}) and perpendicular (L_{\perp}) orientations of BCP lamellar phases, ranging in chain flexibility from flexible Gaussian chains to semi-flexible and rigid chains. For flat and neutral bounding surfaces (no surface preference for one of the two BCP components), the stability of the L_{\perp} lamellae increases with chain rigidity. When the top surface is flat and the bottom substrate is corrugated, increasing the surface roughness enhances the stability of the L_{\perp} lamellae for flexible Gaussian chains. However, an opposite behavior is observed for rigid chains, where the L_{\perp} stability decreases as the substrate roughness increases. We further show that as the substrate roughness increases, the critical value of the substrate preference, uu^{*}, corresponding to an L_{\perp}-to-L_{\parallel} transition, decreases for rigid chains, while it increases for flexible Gaussian chains. Our results highlight the physical mechanism of tailoring the orientation of lamellar phases in thin-film setups. This is of importance, in particular, for short (semi-flexible or rigid) chains that are in high demand in emerging nanolithography and other industrial applications

    Theoretical study of the open-flavor tetraquark Tcsˉ(2900)T_{c\bar{s}}(2900) in the process ΛbK0D0Λ\Lambda_b\to K^0D^0\Lambda

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    Recently, the LHCb Collaboration has measured the processes B0Dˉ0Ds+πB^0\to\bar{D}^0D_s^+\pi^- and B+Dˉ0Ds+π+B^+\to\bar{D}^0D_s^+\pi^+, where the Ds+πD_s^+\pi^- and Ds+π+D_s^+\pi^+ invariant mass distributions show the significant signals of two new open-flavor tetraquark states Tcsˉ(2900)0T_{c\bar{s}}(2900)^0 and Tcsˉ(2900)++T_{c\bar{s}}(2900)^{++}, as the two of the isospin triplet. In this work, we have investigated the process ΛbK0D0Λ\Lambda_b\to K^0D^0\Lambda by taking into account the intermediate nucleon resonance N(1535)N^*(1535) and the tetraquark state Tcsˉ(2900)0T_{c\bar{s}}(2900)^0, which could be dynamically generated by the interactions of the DK/DsρD^*K^*/D^*_s\rho and the pseoduscalar mesons-octet baryons, respectively. Our results show that a clear peak of the open-flavor tetraquark Tcsˉ(2900)T_{c\bar{s}}(2900) may appear in the K0D0K^0D^0 invariant mass distribution of the process ΛbK0D0Λ\Lambda_b\to K^0D^0\Lambda, which could be tested by future experiments.Comment: 9 pages, 11 figures, 1 tabl

    Oxytocin is implicated in social memory deficits induced by early sensory deprivation in mice

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    Acknowledgements We thank Miss Jia-Yin and Miss Yu-Ling Sun for their help in breading the mice. Funding This work was supported by grants from the National Natural Science Foundation of China (81200933 to N.-N. Song; 81200692 to L. Chen; 81101026 to Y. Huang; 31528011 to B. Lang; 81221001, 91232724 and 81571332 to Y-Q. Ding), Zhejiang Province Natural Science Foundation of China (LQ13C090004 to C. Zhang), China Postdoctoral Science Foundation (2016 M591714 to C.-C. Qi), and the Fundamental Research Funds for the Central Universities (2013KJ049).Peer reviewedPublisher PD

    Fascia tissue engineering with human adipose-derived stem cells in a murine model: Implications for pelvic floor reconstruction

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    Background/PurposeMesh-augmented vaginal surgery for treatment of pelvic organ prolapse (POP) does not meet patients' needs. This study aims to test the hypothesis that fascia tissue engineering using adipose-derived stem cells (ADSCs) might be a potential therapeutic strategy for reconstructing the pelvic floor.MethodsHuman ADSCs were isolated, differentiated, and characterized in vitro. Both ADSCs and fibroblastic-differentiated ADSCs were used to fabricate tissue-engineered fascia equivalents, which were then transplanted under the back skin of experimental nude mice.ResultsADSCs prepared in our laboratory were characterized as a group of mesenchymal stem cells. In vitro fibroblastic differentiation of ADSCs showed significantly increased gene expression of cellular collagen type I and elastin (p < 0.05) concomitantly with morphological changes. By contrast, ADSCs cultured in control medium did not demonstrate these changes. Both of the engrafted fascia equivalents could be traced up to 12 weeks after transplantation in the subsequent animal study. Furthermore, the histological outcomes differed with a thin (111.0 ± 19.8 μm) lamellar connective tissue or a thick (414.3 ± 114.9 μm) adhesive fibrous tissue formation between the transplantation of ADSCs and fibroblastic-differentiated ADSCs, respectively. Nonetheless, the implantation of a scaffold without cell seeding (the control group) resulted in a thin (102.0 ± 17.1 μm) fibrotic band and tissue contracture.ConclusionOur results suggest the ADSC-seeded implant is better than the implant alone in enhancing tissue regeneration after transplantation. ADSCs with or without fibroblastic differentiation might have a potential but different role in fascia tissue engineering to repair POP in the future

    Inhibition of Anchorage-Independent Proliferation and G0/G1 Cell-Cycle Regulation in Human Colorectal Carcinoma Cells by 4,7-Dimethoxy-5-Methyl-l,3-Benzodioxole Isolated from the Fruiting Body of Antrodia camphorate

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    In this study, 4,7-dimethoxy-5-methyl-l,3-benzodioxole (SY-1) was isolated from three different sources of dried fruiting bodies of Antrodia camphorate (AC). AC is a medicinal mushroom that grows on the inner heartwood wall of Cinnamomum kanehirai Hay (Lauraceae), an endemic species that is used in Chinese medicine for its anti-tumor and immunomodulatory properties. In this study, we demonstrated that SY-1 profoundly decreased the proliferation of human colon cancer cells (COLO 205) through G0/G1 cell-cycle arrest (50–150 μM) and induction of apoptosis (>150 μM). Cell-cycle arrest induced by SY-1 was associated with a significant increase in levels of p53, p21/Cip1 and p27/Kip1, and a decrease in cyclins D1, D3 and A. In contrast, SY-1 treatment did not induce significant changes in G0/G1 phase cell-cycle regulatory proteins in normal human colonic epithelial cells (FHC). The cells were cultured in soft agar to evaluate anchorage-independent colony formation, and we found that the number of transformed colonies was significantly reduced in the SY-1-treated COLO 205 cells. These findings demonstrate for the first time that SY-1 inhibits human colon cancer cell proliferation through inhibition of cell growth and anchorage-independent colony formation in soft agar. However, the detailed mechanisms of these processes remain unclear and will require further investigation

    Negotiating The Maze: Confronting Dysphagia Together With My Stroke-Afflicted Family Member

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    Aim: To generate a descriptive theory grounded in the responses of family caregivers caring for their family stroke survivors with dysphagia during hospitalization. Design and Method: A qualitative study employing the grounded theory method was used. Fifteen family caregivers participated in comprehensive interviews. The interview data were analyzed using the constant comparative method. Findings: ‘Negotiating the maze: Confronting dysphagia with my stroke-afflicted family member’ was the core category guiding the care process for dysphagia family members among caregivers. After surviving stroke, the caregivers felt ‘more confusion less rejoicing’ as the antecedent condition. The following three interaction categories were identified: (1) ‘being overwhelmed by nasogastric (NG) tube issues’; (2) ‘searching for the right helper and information’; and (3) ‘food culture conflicts with the formula diet administered through the NG tube’. Additionally, ‘Maintaining positivity’ described the consequence of this process. Conclusions: This study highlights the critical perspective of family members who care for dysphagia stroke survivors in the hospital. Participants were under tremendous pressure during the disease treatment process. However, all attempted to maintain a positive attitude and treasured the chance to accompany their family members. Clinical Relevance: These findings can assist health professionals in charting the effects of dysphagia and in understanding the problems and needs according to the subjective perspectives of family caregivers. They can also provide a necessary foundation for comprehensive care interventions for family caregivers of stroke survivors with dysphagia

    The Influences of Hedonic and Experiential Marketing on Consumer Perceptions of Quality and Value: An Evaluation of Internet Website Appeals

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    [[abstract]]隨著網際網路的興起,消費者的認知與決策模式已成為網路行銷中重要課題。本研究採用線性結構模式來衡量研究變數之關係,並發展一整體模式,探討享樂性與實用性的網路特徵、消費者體驗知覺與認知知覺、體驗價值與體驗品質、與購買意圖等構念之間的關係。本研究挑選了20個化妝品網頁與20個旅館網頁。隨機指派受訪者連結與閱讀其中一個網頁,並直接在網路上填寫問卷。根據結構方程模式之結果,在享樂知覺方面,網站特徵顯著且正向地影響體驗知覺與體驗價值,再者,體驗知覺亦顯著地影響體驗價值。另一方面,在實用知覺方面,網站特徵會顯著地影響消費者對於網站或產品的認知知覺,而認知知覺則會影響消費者對於網站或產品的品質認知。此外,體驗價值與體驗品質之間存在顯著的關連性;兩者亦同時會影響購買意圖。根據變異數分析之結果,知覺到網站具有高實用性與高享樂性之特徵的消費者,相較於知覺到網站具有低實用性與低享用性之特徵的消費者,在體驗知覺、認知知覺、體驗價值與體驗品質等各方面均有較高的得分。其次,知覺到網站具有高實用性與低享樂性特徵之消費者,則僅在認知知覺與體驗品質上有較高的得分。 Both thinking and feeling decision making modes that are conceived as independent systems are involved in this article and are examined for website consumption. Specifically, this article attempted to develop a comprehensive model to identify the interrelationship among hedonic and utilitarian website characteristics, consumer's experiential and cognitive perceptions, perceived experiential value and quality, and purchasing intention. This article picks up 40 websites which include 20 cosmetics and 20 hotel websites. Participants were randomly assigned to link and read one of the 40 websites, and then were asked to fill in a questionnaire on Internet. Finally, 422 usable questionnaires were collected, 224 from cosmetics and 198 from hotel Websites. In order to assess the hypothesized relationships, the structural equation model (SEM) was employed using AMOS 4.0 to investigate the relationship among research variables. Additionally, cluster analysis by K-means method was adopted to divide the participants into four groups based on two levels of utilitarian website environment and two levels of hedonic website environment. ANOVA was used to evaluate the differences on each research variables among these four groups. According to the results of SEM, it is suggested that the level of hedonic characteristics of website significantly and positively impacts experiential perception and experiential value, and the level of experiential perception also significantly influences on experiential value. On the other hand, website with utilitarian characteristics will impact a customer's cognitive perception toward websites/products, which in turn influences the perception of website/product quality. In addition, perceived quality was also significantly related to experiential value. Purchasing intention was influenced by experiential value and perceived quality. According to the results of ANOVA, respondents perceiving high utilitarian/high hedonic websites tend to perceive significant higher scores on experiential perceptions, cognitive perception, experiential value, and perceived quality, than respondents perceiving low utilitarian/low hedonic websites. Respondents perceiving high utilitarian/low hedonic website environment tend to perceive significantly higher scores only on cognitive perception and perceived quality

    Omega-3 Fatty Acid Intervention Suppresses Lipopolysaccharide-Induced Inflammation and Weight Loss in Mice

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    Bacterial endotoxin lipopolysaccharide (LPS)-induced sepsis is a critical medical condition, characterized by a severe systemic inflammation and rapid loss of muscle mass. Preventive and therapeutic strategies for this complex disease are still lacking. Here, we evaluated the effect of omega-3 (n-3) polyunsaturated fatty acid (PUFA) intervention on LPS-challenged mice with respect to inflammation, body weight and the expression of Toll-like receptor 4 (TLR4) pathway components. LPS administration induced a dramatic loss of body weight within two days. Treatment with n-3 PUFA not only stopped loss of body weight but also gradually reversed it back to baseline levels within one week. Accordingly, the animals treated with n-3 PUFA exhibited markedly lower levels of inflammatory cytokines or markers in plasma and tissues, as well as down-regulation of TLR4 pathway components compared to animals without n-3 PUFA treatment or those treated with omega-6 PUFA. Our data demonstrate that n-3 PUFA intervention can suppress LPS-induced inflammation and weight loss via, at least in part, down-regulation of pro-inflammatory targets of the TLR4 signaling pathway, and highlight the therapeutic potential of n-3 PUFA in the management of sepsis
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