142 research outputs found
Supplemental Material, sj-pdf-1-bsa-10.26599_BSA.2021.9050008 - Neuroprotective effects of adipose‐derived stem cells on ferrous sulfate‐induced neurotoxicity
No full textSupplemental Material, sj-pdf-1-bsa-10.26599_BSA.2021.9050008 for Neuroprotective effects of adipose‐derived stem cells on ferrous sulfate‐induced neurotoxicity by Qian Wu, Chao Pan, Yang Hu, Gaigai Li, Shiling Chen, Jie Jing, Jingfei Yang and Zhouping Tang in Brain Science Advances</p
Optimized Extraction of Polysaccharides from Bergenia emeiensis Rhizome, Their Antioxidant Ability and Protection of Cells from Acrylamide-induced Cell Death
No full textBergeniaemeiensis is a traditional herb in Chinese folk medicine. Most related studies are focused on the bioactivity of bergenin, neglecting other bioactive compounds. In our previous work, polysaccharides were identified in B. emeiensis rhizome. To evaluate the extraction process and the antioxidant ability of these polysaccharides, a response surface method and antioxidant assays were applied. The results showed that the yield of polysaccharides was highly affected by extraction time, followed by temperature and solvent-to-sample ratio. Under the optimal conditions (43 °C, 30 min and 21 mL/g), the yield was 158.34 ± 0.98 mg/g. After removing other impurities, the purity of the polysaccharides from B. emeiensis (PBE) was 95.97 ± 0.92%. The infrared spectrum showed that PBE had a typical polysaccharide structure. Further investigations exhibited the PBE could scavenge well DPPH and ABTS free radicals and chelate Fe2+, showing an excellent antioxidant capacity. In addition, PBE also enhanced the cell viability of HEK 239T and Hep G2 cells under acrylamide-exposure conditions, exhibiting great protection against the damage induced by acrylamide. Therefore, PBE can be considered a potential natural antioxidant candidate for use in the pharmaceutical industry as a health product
The Antioxidant Capacity In Vitro and In Vivo of Polysaccharides From Bergenia emeiensis
No full textPolysaccharides from Bergenia emeiensis (PBE) showed a robust antioxidant ability on scavenging free radicals in vitro. However, the further antioxidant potential in cell level and in vivo was still unknown. Therefore, in this present study, the protective effect of PBE on human cervical carcinoma cell (Hela) cells and Caenorhabditis elegans against oxidative stress was evaluated. The results showed PBE could reduce the reactive oxygen species (ROS) level in Hela cells and promote the mitochondrial membrane potential. Then, the cell apoptosis was reduced. Moreover, PBE could enhance the survival of C. elegans under thermal stress to 13.44%, and significantly reduce the ROS level, which was connected with the overexpression of sod-3 and the increased nuclear localization of daf-16 transcription factor. Therefore, PBE exhibited a strong antioxidant capacity in the cellular level and for a whole organism. Thus, polysaccharides from B. emeiensis have natural potential to be a safe antioxidant
Optimized seismic design and dynamic response analysis of mass timber rocking wall lateral system
No full textIncludes bibliographical references.2023 Spring.As societal expectations for urban development move towards a more resilient and sustainable focus, renewable construction materials are gaining more attention in the past decade and for the foreseeable future. One of the most well-known environmental challenges facing society today is greenhouse gas emissions, specifically carbon dioxide. The building and construction industry is one of the largest contributors to global carbon dioxide emission, which occurs during the construction and occupancy life cycle of buildings. Timber is considered as a sustainable and carbon-friendly solution for building systems due to its renewable nature and the potential ability to store carbon long term.
Mass timber is a family of engineered wood products that are produced from smaller timber components joined together using glue or mechanical connectors. Utilizing mass timber floor system with glulam gravity frame gives the possible solutions to create tall timber buildings with flexible floor plan applications. Mass timber gravity system can be combined with traditional steel and concrete lateral systems. But there are benefits to exploring a lateral system made also out of mass timber products. Firstly, this will enable a more streamlined construction process because the construction will only require a timber construction crew. Secondly, past studies revealed that a new type of lateral resisting system called mass timber rocking walls can potentially improve the resilience of the building during earthquakes. This system utilizes mass timber products as wall panels and unbonded post-tension bars to tie the rocking panel to the foundation. The rocking wall lateral system can achieve a ductile response and assure recentering capability. Energy dissipation devices such as U-shaped flexural plates (UFPs) are used as supplement dampers to dissipate energy and reduce accelerations. The use of replaceable dampers also allows localized damage to specific components that can be replaced after large seismic events.
In this thesis, a simplified numerical model for dynamic response prediction of mass timber building with PT rocking wall system was developed and validated with shake table test data. The concept of the simplified model is to concentrate the nonlinearity of that system into a few nonlinear rotational springs and represent rocking wall panel with elastic lumped mass spring series to reduce the computational cost. The simplified numerical model was first validated using the data from the NHERI TallWood 2-story tests conducted in 2017. Then the author expanded the simplified modeling concept using SAP2000 for the 10-story mass timber building which will be tested in spring 2023. Another 2D analytical model of the 10-story mass timber building is also developed to consider torsional responses.
An optimized performance-based seismic design (PBSD) frame is developed by expanding the existing PBSD framework through an automated procedure to obtain optimized design solutions utilizing Genetic Algorithms (GA). While simplified models are much more computationally efficient than traditional FEM models, a large amount of simulation needed for optimized PBSD using GA still needs hours of simulation to complete. To enable a more reasonable time frame for the proposed PBSD optimization, a generalized artificial neural network (ANN) model was trained using simplified mechanical models and replaced the nonlinear time history simulation process in the GA search for optimized PBSD. A web-based automatic design application as well as a MATLAB program was developed to enable the selection of rocking wall key design parameters based on the tools developed in this study.
The author also actively participated in the collaborative research and development effort that leads to the testing of the NHERI TallWood 10-story building. Relevant research and design work conducted by the author as part of the testing project is also presented here
Targeted Comprehensive Strategy for Lightning Protection and Its Application in the Anhui Power Grid
No full text
PP-007 Pathogen distribution and drug resistance analysis of inpatients' infection between 2007 and 2008 in infectious disease hospital
No full textDevelopment of a methodology for probabilistic alignment selection and design for drill-and-blast hard-rock tunnels
No full textIncludes bibliographical references.2022 Fall.Transportation tunnels are heavily studied and debated before they are eventually constructed. The lead time on tunnel projects is typically years and sometimes decades. During the early phases of tunnel planning, it is often necessary to evaluate a wide range of alignment, excavation method, and support system options to find those which are technically feasible and cost-effective. However, comparing a wide or infinite range of alignment, excavation method, and support system options can be time-consuming, tedious, and expensive. Tunnel alignments are frequently selected not based on any quantitative evaluation and comparison of feasibility but on professional judgment or political whim. There are many components to a tunnel's feasibility including highly uncertain ground conditions, many possible excavation methods, and variable support options. The goal of this research project is to bring some quantifiable metrics to the comparison of alternative tunnel options.
To accomplish this goal, the author has developed a 3D implicit geological model of the EJMT case study in Colorado which includes engineering geologic parameters of interest such as rock mass classification parameters Q and RMR. This model includes quantified uncertainty in each parameter. Using this probabilistic geologic model a new alignment optimization algorithm which seeks the best possible tunnel alignment through a given volume is developed. Further, a numerical finite difference model was calibrated to available EJMT case study data. This calibrated model validates the results of the alignment optimization algorithm. The result is a novel and useful tool and methodology which can effectively evaluate and compare many plausible alignments and select the best possible option for further design studies
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