A periodontal tissue regeneration strategy via biphasic release of zeolitic imidazolate framework-8 and FK506 using a uniaxial electrospun Janus nanofiber

Guided tissue regeneration (GTR) strategy is an effective approach to repair periodontal defect by using GTR membranes. However, the commercial GTR membranes still have limitations in periodontal tissue regeneration owing...

Bottom-up Urban Regeneration and Vacant Buildings: A Framework to understand how Empty Properties can be Strategically Embedded in Bottom-up Projects

The bottom-up projects, in the years after the Great Crisis, have been considered as a popular measure to solve urban issues, overcoming the conditions of austerity faced by public actors. However, these initiatives not only seem confined to solve very specific issues but are often linked to a more comprehensive urban regeneration strategy, thus capable of addressing the economic, social and physical aspects of a wider part of the city. This article presents the first findings of wider research, which analyses the link between bottom-up practices and the concept of urban regeneration. In particular, this article focuses on an element that appears to be fundamental for the development of these bottom-up urban regeneration practices: the presence of vacant buildings available for the reuse. This article suggests the possibility to analyse how vacant buildings are embedded in these practices through three steps, called steps for the regeneration through the reuse of vacant buildings (SteRVs), namely Recognition, Appropriation and Design. The validity of the three phases is demonstrated through a multiple case study analysis, that considers two renowned bottom-up urban regeneration cases developed in Europe mainly after 2000: Farm Cultural Park, in Favara (Italy) and NDSM wharf, in Amsterdam.

Mathematical Tool Based on Breakthrough Curves to Evaluate the Economic Advantages of Chemical Regeneration of Activated Carbon in Power Plants: A Comparative Study

A mathematical tool has been developed to evaluate the economic advantages of in-situ chemical regeneration of fixed-bed industrial adsorbers of granular activated carbon for cooling water treatment systems in Cuban power plants. Two scenarios of activated carbon (AC) management in a power plant were compared by applying the proposed model. The economic profit by implementing the regeneration strategy as a function of the number of regeneration cycles was determined and optimized. Breakthrough curves were obtained to assess the adsorption performance of the AC after progressive saturation–chemical regeneration cycles using synthetic water and hydrochloric acid, respectively. For the first saturation cycle, the breakthrough time was 272 min and after 10 cycles, it was reduced to 58 min, indicating a decrease of the adsorption capacity of 21%. The AC adsorption performance in terms of saturation time as a function of the number of regeneration cycles was considered one of the tool parameters. The proposed tool allows to determine the optimal number of regeneration cycles for a maximum economic profit in the regeneration strategy. It was demonstrated, using the proposed tool, that after an optimum of seven regeneration cycles, the power plant expends only 26% of the total investment. The simplicity of the tool permits a rapid way to find the most profitable number of regeneration cycles by combining economic, technical and adsorption efficiency parameters in one function, thus improving the AC management strategy at an industrial scale with corresponding environmental and economic advantages, including sustainability.

Special Issue “Urban and Buildings Regeneration Strategy to Climatic Change Mitigation, Energy, and Social Poverty after a World Health and Economic Global Crisis”

Throughout the 21st century, urban reports demand solutions to the obsolescence and aging process suffered by the existing buildings, due to the growth and expansion of cities that took place in the second half of the 20th century [...]

Efficient one-step biocatalytic multienzyme cascade strategy for direct conversion of phytosterol to C17-hydroxylated steroids

Steroidal 17-carbonyl reduction is crucial to the production of natural bioactive steroid medicines, boldenone (BD) is one of the important C17-hydroxylated steroids. Although efforts have been made to produce BD through biotransformation, the challenge of complex transformation process, high substrates cost, and low catalytic efficiencies have yet to be mastered. Phytosterol (PS) is the most widely accepted substrate for the production of steroid medicines due to its similar foundational structure and ubiquitous sources. 17β-Hydroxysteroid dehydrogenase (17βHSD) and its native electron donor play significant roles in the 17β-carbonyl reduction reaction of steroids. In this study, we bridged 17βHSD with a cofactor regeneration strategy in Mycobacterium neoaurum to establish a one-step biocatalytic carbonyl reduction strategy for efficient biosynthesis of BD from PS for the first time. After investigating different intracellular electron transfer strategies, we rationally designed the engineered strain with co-expression of 17βhsd and glucose-6-phosphate dehydrogenase (G6PDH) gene in M. neoaurum . With establishment of an intracellular cofactor regeneration strategy, the ratio of [NADPH]/[NADP + ] was maintained at a relatively high level, the yield of BD increased from 17% (in MNR M3M- ayr1 S.c ) to 78% (in MNR M3M- ayr1 & g6p with glucose supplementation), and the productivity was increased by 6.5 times. Furthermore, under the optimal glucose supplementation condition, the yield of BD reached 82%, which is the highest yield reported by transformation from PS with one-step. This study demonstrated an excellent strategy for production of many other valuable carbonyl reduction steroidal products from natural cheap raw materials. Importance Steroid C17-carbonyl reduction is one of the important transformations for the production of valuable steroidal medicines or intermediates for further synthesis of steroidal medicines, but it remains a challenge through either chemical or biological synthesis. Phytosterol can be obtained from low-cost residue of waste natural materials, and it is preferred as the economical and applicable substrate for steroid medicines production by Mycobacterium . This study explored a green and efficient one-step biocatalytic carbonyl reduction strategy for direct conversion of phytosterol to C17-hydroxylated steroids by bridging 17β-Hydroxysteroid dehydrogenase with a cofactor regeneration strategy in Mycobacterium neoaurum . This work has practical value for the production of many valuable hydroxylated steroids from natural cheap raw materials.