64 research outputs found

    Based on e-Business technology to construct logistics information service platform of renewable resources ——Taking Nanning city as an example

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    With the rapid development of economy and the increase of population, we are facing the stern challenge of lack of resources and environment pollution. Through the recycling of resources we can reduce the exploitation of native resources and save energy. At present, the level of recycling resources in Nanning city is quite low, as do the utilization rate of recovery. The recyclable resource logistics information service platform is built to collect recyclable resources, also have other function like product display, online trading, information management and customer service, the platform can give recyclable resources information service to citizens of Nanning, which have a great significance on recyclable resources industry in Nanning

    Development of a micro-indentation device for measuring the mechanical properties of soft materials

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    AbstractIndentation is a simple and nondestructive method to measure the mechanical properties of soft materials, such as hydrogels, elastomers and soft tissues. In this work, we have developed a micro-indentation system with high-precision to measure the mechanical properties of soft materials, where the shear modulus and Poisson's ratio of the materials can be obtained by analyzing the load–relaxation curve. We have validated the accuracy and stability of the system by comparing the measured mechanical properties of a polyethylene glycol sample with that obtained from a commercial instrument. The mechanical properties of another typical polydimethylsiloxane sample submerged in heptane are measured by using conical and spherical indenters, respectively. The measured values of shear modulus and Poisson's ratio are within a reasonable range

    Bioprinting-Based High-Throughput Fabrication of Three-Dimensional MCF-7 Human Breast Cancer Cellular Spheroids

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    ABSTRACTCellular spheroids serving as three-dimensional (3D) in vitro tissue models have attracted increasing interest for pathological study and drug-screening applications. Various methods, including microwells in particular, have been developed for engineering cellular spheroids. However, these methods usually suffer from either destructive molding operations or cell loss and non-uniform cell distribution among the wells due to two-step molding and cell seeding. We have developed a facile method that utilizes cell-embedded hydrogel arrays as templates for concave well fabrication and in situ MCF-7 cellular spheroid formation on a chip. A custom-built bioprinting system was applied for the fabrication of sacrificial gelatin arrays and sequentially concave wells in a high-throughput, flexible, and controlled manner. The ability to achieve in situ cell seeding for cellular spheroid construction was demonstrated with the advantage of uniform cell seeding and the potential for programmed fabrication of tissue models on chips. The developed method holds great potential for applications in tissue engineering, regenerative medicine, and drug screening

    An approach to quantifying 3D responses of cells to extreme strain

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    The tissues of hollow organs can routinely stretch up to 2.5 times their length. Although significant pathology can arise if relatively large stretches are sustained, the responses of cells are not known at these levels of sustained strain. A key challenge is presenting cells with a realistic and well-defined three-dimensional (3D) culture environment that can sustain such strains. Here, we describe an in vitro system called microscale, magnetically-actuated synthetic tissues (micro-MASTs) to quantify these responses for cells within a 3D hydrogel matrix. Cellular strain-threshold and saturation behaviors were observed in hydrogel matrix, including strain-dependent proliferation, spreading, polarization, and differentiation, and matrix adhesion retained at strains sufficient for apoptosis. More broadly, the system shows promise for defining and controlling the effects of mechanical environment upon a broad range of cells

    Risk Prediction of Second Primary Malignancies in Primary Early-Stage Ovarian Cancer Survivors: A SEER-Based National Population-Based Cohort Study

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    Purpose: This study aimed to characterize the clinical features of early-stage ovarian cancer (OC) survivors with second primary malignancies (SPMs) and provided a prediction tool for individualized risk of developing SPMs. Methods: Data were obtained from the Surveillance, Epidemiology and End Results (SEER) database during 1998–2013. Considering non-SPM death as a competing event, the Fine and Gray model and the corresponding nomogram were used to identify the risk factors for SPMs and predict the SPM probabilities after the initial OC diagnosis. The decision curve analysis (DCA) was performed to evaluate the clinical utility of our proposed model. Results: A total of 14,314 qualified patients were enrolled. The diagnosis rate and the cumulative incidence of SPMs were 7.9% and 13.6% [95% confidence interval (CI) = 13.5% to 13.6%], respectively, during the median follow-up of 8.6 years. The multivariable competing risk analysis suggested that older age at initial cancer diagnosis, white race, epithelial histologic subtypes of OC (serous, endometrioid, mucinous, and Brenner tumor), number of lymph nodes examined (<12), and radiotherapy were significantly associated with an elevated SPM risk. The DCA revealed that the net benefit obtained by our proposed model was higher than the all-screening or no-screening scenarios within a wide range of risk thresholds (1% to 23%). Conclusion: The competing risk nomogram can be potentially helpful for assisting physicians in identifying patients with different risks of SPMs and scheduling risk-adapted clinical management. More comprehensive data on treatment regimens and patient characteristics may help improve the predictability of the risk model for SPMs

    Nanoscale integrin cluster dynamics controls cellular mechanosensing via FAKY397 phosphorylation

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    Transduction of extracellular matrix mechanics affects cell migration, proliferation, and differentiation. While this mechanotransduction is known to depend on the regulation of focal adhesion kinase phosphorylation on Y397 (FAKpY397), the mechanism remains elusive. To address this, we developed a mathematical model to test the hypothesis that FAKpY397-based mechanosensing arises from the dynamics of nanoscale integrin clustering, stiffness-dependent disassembly of integrin clusters, and FAKY397 phosphorylation within integrin clusters. Modeling results predicted that integrin clustering dynamics governs how cells convert substrate stiffness to FAKpY397, and hence governs how different cell types transduce mechanical signals. Existing experiments on MDCK cells and HT1080 cells, as well as our new experiments on 3T3 fibroblasts, confirmed our predictions and supported our model. Our results suggest a new pathway by which integrin clusters enable cells to calibrate responses to their mechanical microenvironment

    The moderating effect of environmental dynamism on green product innovation and performance

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    Environmental management has been researching extensively in the last two decades. Pressure from environmental regulations or policies plays an important role to boost environmental management practices. Nevertheless, the relationship between such pressure and the ultimate firm performance is not very obvious. Although green product innovation has been recognized as a predictor to improve environment performance, there is a lack of discussion in the literature to examine the mediating effect of green product innovation between the aforementioned pressure and firm performance. Additionally, most previous studies adopted a static view which ignores the implications on external dynamic factors in many empirical studies. In this connection, this study contributes to the field of knowledge by filling these two gaps. More specifically, this study: (i) examines the effect of green product innovation on the relationship between pressure of environmental regulations (or policies) and firm performance; and (ii) evaluates the moderating effect of environmental dynamism on the relationship between green production innovation and firm performance. A questionnaire survey is conducted in an emerging country, China, to verify the hypotheses.Institute of Textiles and Clothin

    The role of Guanxi in green supply chain management in Asia's emerging economies: A conceptual framework

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    In recent decades, rapid industrial modernization and economic growth have brought substantial environmental problems such as air pollution, hazardous waste, and water pollution for the Asian Emerging Economies (AEE), in particular China, Taiwan, India, Malaysia, Indonesia, Thailand, and South Korea. These countries have started to adopt green supply chain management (GSCM) as a strategy to reduce the environmental impact. There are anecdotal evidences that the adoption of GSCM in this region is partly influenced by Guanxi – a cultural norm, which plays a significant role in relationship governance within supply chain activities among the AEE. Based on a systematic literature review, we develop a conceptual framework that characterizes the drivers and barriers for the adoption of GSCM practices, incorporating Guanxi as a moderator in the manufacturing sector of the AEE. The conceptual framework addresses the roles of two types of Guanxi in the adoption of GSCM: the relational Guanxi at individual level based on social exchange theory and the aggregated Guanxi at firm level derived from social capital theory. This recognition of Guanxi at two separate decision levels help companies better manage their relationships while they green their supply chains. Directions for future research and managerial implications are discussed accordingly
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