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Alex Buchberger Harpinder Saini Kiarash Rahmani Eliato Azadeh Zare Ryan Merkley Yang Xu Julio Bernal Robert Ros Mehdi Nikkhah Dr. Nicholas Stephanopoulos 《Chembiochem : a European journal of chemical biology》2021,22(10):1755-1760
Biomaterials with dynamically tunable properties are critical for a range of applications in regenerative medicine and basic biology. In this work, we show the reversible control of gelatin methacrylate (GelMA) hydrogel stiffness through the use of DNA crosslinkers. We replaced some of the inter-GelMA crosslinks with double-stranded DNA, allowing for their removal through toehold-mediated strand displacement. The crosslinks could be restored by adding fresh dsDNA with complementary handles to those on the hydrogel. The elastic modulus (G’) of the hydrogels could be tuned between 500 and 1000 Pa, reversibly, over two cycles without degradation of performance. By functionalizing the gels with a second DNA strand, it was possible to control the crosslink density and a model ligand in an orthogonal fashion with two different displacement strands. Our results demonstrate the potential for DNA to reversibly control both stiffness and ligand presentation in a protein-based hydrogel, and will be useful for teasing apart the spatiotemporal behavior of encapsulated cells. 相似文献
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Nima Hematyar Tomas Policar Azadeh Mohagheghi Samarin Sabine Sampels Ievgeniia Gazo Jan Mraz 《International Journal of Food Science & Technology》2020,55(12):3622-3629
Microbial activity and then oxidation progress are the most important freshness indicators during post-mortem. In this study, we monitored proteomic and microbial changes, as well as biochemical degradation, in the tail and claw muscles of crayfish stored for 12 days at +4 °C. One specified protein band at 107 kDa in the claw muscle and two specified protein bands in the tail muscle at 140 and 36–40 kDa were identified. Western blotting indicated a higher amount of oxidised proteins in the tail compared to the claw muscle. Tail muscle showed higher oxidation progress and calpain activity than claw one. Both muscles were spoiled after 12 days with respect to total viable counts. In the first days, calpain activity is the main reason for protein degradation, while protein oxidation dominates for the rest of the time. Lipid–protein oxidation progress showed probably, protein oxidation started earlier than lipid oxidation in both muscles. 相似文献
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Deborah G. Martin Azadeh Hadizadeh Esfahani Olivia R. Williams Richard Kruger Joseph Pierce James DeFilippis 《Housing Studies》2020,35(3):395-414
AbstractDiscourses regarding homeownership in the United States emphasize housing as an economic investment. This focus fosters a number of problems, including inflated housing values, increased segregation, economic divisions, and the foreclosure crisis. Community land trusts (CLTs) put land in a non-profit trust to keep it affordable long-term. We examine CLTs as affordable housing organizations where individual residents own homes in the trust and lease the land underneath from the CLT. Interviews of CLT homeowners and staff in Minnesota, USA, show that the use value of CLT housing creates opportunities for different life choices. CLT homeowners cite stability and autonomy as the primary benefits of homeownership. They expressed newfound confidence and freedom to pursue personal goals and live less restricted lives after moving into CLT homes, a finding also emphasized by CLT staff. Limited equity housing such as CLTs can both reinforce dominant meanings of homeownership as providing security and autonomy, while also fostering access and affordability for low-income residents. 相似文献
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Empirical evaluation of river basin sustainability affected by inter‐basin water transfer using composite indicators 下载免费PDF全文
Maryam Kefayati Bahram Saghafian Azadeh Ahmadi Hossein Babazadeh 《Water and Environment Journal》2018,32(1):104-111
In this study, a practical approach to evaluate the sustainability of river basins subjected to an inter‐basin water transfer project is developed. Selection of appropriate evaluation indicators is pivotal to such approach. To make use of huge amount of data, composite indicators of sustainability (CIS) should be utilised. The proposed approach relies on 15 sustainability indicators (SI) that cover three major criteria namely (economic, social and environmental), and aggregates them into eight different types of sustainability indices for a more robust outcome. Two scenarios were considered within the source and recipient basins. Furthermore, multivariate principal component analysis (PCA) was applied to determine principal and non‐principal indicators for the two river basins. The ability of CIS and PCA methods were verified via correlation and simple regression methods respectively. The results demonstrated that inter‐basin water transfer may improve sustainability, provided that a proper water resource management is enforced. 相似文献
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Kamyar Karbasi Arani Mohammad S. Marefat Abolfazl Amrollahi‐Biucky Mohammad Khanmohammadi 《The Structural Design of Tall and Special Buildings》2013,22(3):267-290
Concrete buildings reinforced by plain (smooth) bars are one of the special types of old reinforced concrete buildings that were generally built before the 1970s. As columns are generally the most important structural members of a framed structure, understanding their realistic seismic behavior is very helpful in estimating structural deformations, forces and energy dissipation capacities. Furthermore, in most of old‐framed building structures, columns play a key role in the final behavior because of strong beam–weak column conditions. This article reports the results of experimental monotonic and cyclic tests on four concrete column specimens reinforced by plain bars and with various types of splices. Through the experimental results, it tried to obtain more clarification on the complicated behavior of such old reinforced members as well as the differences compared with relevant results of columns reinforced by deformed bars. It was realized that slip (fixed‐end rotation) contribution is the major source of deformation in all specimens independent from type of splices. Moreover, general mode of behavior was restrained‐rocking action independent of type of splice detailing. A simple theory for the explanation of hysteresis force–displacement response was proposed. The theory assumes a concrete block rocking element that is restrained with plain bars at both ends. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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Azadeh Ebrahimian Pirbazari Mohammad Ali Zanjanchi 《Korean Journal of Chemical Engineering》2014,31(2):218-223
The photocatalytic activity of cobalt tetrasulphophthalocyanine immobilized onto MCM-41 was investigated for photocatalytic degradation of 4-chlorophenol (4-CP) in aqueous solutions. Immobilization of cobalt tetrasulphophthalocyanine complex to the walls of MCM-41 was performed by pre-anchorage of 3-(aminopropyl)-triethoxysilane (APTES) onto MCM-41 via post-synthesis method. X-ray diffraction, nitrogen physisorption, diffuse reflectance spectroscopy, energy-dispersive X-ray and FT-IR methods were used to characterize the product. Photocatalytic efficiency of the prepared photocatalyst for degradation of 4-CP was tested under illumination of UV-A and visible light. The reaction intermediates were identified by gas chromatography-mass spectrometry (GC-MS) technique. 相似文献
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The present study proposes an algorithm for fault detection in terms of condition‐based maintenance with data mining techniques. The proposed algorithm is applied on an aircraft turbofan engine using flight data and consists of two main sections. In the first section, the relationship between engine exhaust gas temperature (EGT) as the main engine health monitoring criterion and other operational and environmental parameters of the engine was modelled using the data‐driven models. In the second section, a data set including EGT residuals, that is, the difference between the actual EGT of the system and the EGT estimated by the developed model in the health conditions of the engine, was created. Finally, faults occurring in each flight were detected based on the identification of abnormal events by a one‐class support vector machine trained by the health condition EGT residual data set. The results indicated that the proposed algorithm was an effective approach for inspecting aircraft engine conditions and detecting faults, with no need for technical knowledge on the interior characteristics of the aircraft engine. 相似文献