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Editorial

25 August 2023

Article

21 August 2023

Role of Youth in Implementing SDGs Future City in Tosacho, Kochi, Japan

The “SDG Future Cities” established by the SDG (Sustainable Development Goals) Promotion Headquarters of Cabinet Office of Government of Japan, are being expanded to all municipalities in Japan through government support for the efforts of leading municipalities. Tosa town is a small town with less than 4000 people with high aging population and surrounded by mountains in Kochi Prefecture. The town was selected as one of the SDG Future City in 2020. In this paper, through a literature review, interviews with the Tosa Town Office, and a questionnaire survey and interview with residents of Tosa town, we considered what young people need to do to achieve SDG-11. Although Tosa Town has a variety of local government initiatives, the definition of a town where young people can continue to live, as revealed in the literature review, was found to be insufficient in terms of “economic resources,” “decision-making,” “data,” and “knowledge”. However, it was found that “community leaders,” “nature/topography,” and “community/people” are the most important factors for creating a town where people can continue to live. As for future issues, it is necessary to take measures for “decision-making,” “data,” and “knowledge,” as well as to solve issues specific to Tosa town.

Keywords: Sustainable Development Goal 11; SDG future cities; Tosa Town, Kochi Prefecture; Youth

Review

15 August 2023

Green Composites Using Naturally Occurring Fibers: A Comprehensive Review

Depletion of non-renewable resources and health hazards of petroleum-based polymers and plastics has enforced the development of eco-friendly materials. The use of conventional plastics has to be minimized and can be replaced with environmentally friendly and sustainable bio-based polymers or biopolymers due to extensive environmental impact. A major share of petroleum-based polymers is used for polymeric composites with research focus on green composites and biocomposites containing renewable/bioderived matrix polymer and fillers from naturally occurring fibers. Biocomposites hold great promise to replace petroleum-based polymer composites owing to their lower cost, non-toxicity, abundance of raw material, renewability, and high specific strength. All these merits of biocomposites have led to an increment in the development of new biocomposites with enhanced properties, wide applicability and ever demanding criteria. The recently published review studies detailed the raw materials used, fabrication techniques, characterization, and applications including biodegradation and rheological studies performed in recent years. This review covers all the important properties of biocomposites along with detailed description of synthesis, properties, characterizations and applicability of these green composites in several areas. The review also focuses on their raw materials, types, recent biocomposites, processing techniques, characterizations, applications, and current challenges with future aspects.

Keywords: Biopolymers; Natural fibers; Biocomposites; Biodegradation; Sustainability

Article

15 August 2023

Thermal and Economic Evaluations of a Drain Water Heat Recovery Device under Transient Conditions

This study explores the transient characteristics of a drain water heat recovery (DWHR) device employed for heat recovery from warm grey water in buildings. Experimental measurements were conducted to investigate the response time of the DWHR device under various flow conditions. The thermal performance of the system was assessed using both transient and steady-state effectiveness analyses. The findings reveal that the response time is influenced by the water volume within the system, with an increase observed, and by the water flow rate, which leads to a decrease in response time. Additionally, a decrease in effectiveness is noted when hot water is used in short and frequent intervals. Furthermore, an economic analysis demonstrates that considering the transient behavior of the device results in a significant overall decrease of 37% in annual savings. Specifically, the usage of sinks exhibits a reduction in annual savings by 56%, while showers show a decrease of 13% in annual savings.

Keywords: Drain water heat recovery; Heat exchanger; Experimental investigation; Transient

Article

08 August 2023

Where Do Chinese Doublets Come From?—The Doublets from Prehistory to the Era of the Book of Poetry

The earliest writing in China is the oracle bone inscriptions of the Shang Dynasty, which records early Chinese, also known as oracle bone Chinese, which are all monosyllabic-words (1300 BC). In the Bronze Inscriptions of the Western Zhou Dynasty and later handed down documents, doublets appear (beginning in 1046 BC). At present, the philological academy believes that the doublets recorded with two Chinese single-characters come from reduplication of two single-character symbols, but there is no complete argument and reliable evidence. This article, by using the opposite method of argument, reversely assumes that the single-characters (monosyllabic words) come from doublets and tries to demonstrate it. The article proves the truth of the origin of doublets based on the word distribution and semantic correspondence between doublets and single-characters in “the Book of Poetry”, that is, doublets are the source and single-characters are flows. Among them, 39.66% of the doublets have no corresponding single-characters, and they are the characters created to record doublets; 41.92% of the meanings of doublets have nothing to do with the meanings of single-characters, which proves that the doublets does not come from the combination of single-characters; 12.46% of the meanings of doublets are interpreted as the meanings of single-characters, which are the subjective errors of later generations of interpreters; the remaining 5.66% are only associated with proclitics and enclitics rather than single-characters. Finally, the article proposes that doublets originate from a unique mechanism of expressive morphology, which is a new type of etymological theory outside the morphological grammar system, and can create various polysyllabic ideophones, including the onomatopoeia or mimetic words. The article proves that a language begins with the creation of words. In the prehistoric period before the oracle bone inscriptions, Chinese ancestors had invented a large number of distinctive doublets (AA), couplets (AB) and other polysyllabic words (xA, or ABB, ABA’B), or ideophones. Due to the difficulty of writing, the doublets were hidden in spoken language for hundreds of years. It was not until the time of “Book of Poetry” and “Book of History” in the bronze inscriptions of the Western Zhou Dynasty that it entered the history and has continued to this day. Doublets are the earliest Chinese words and the beginning of Chinese civilization.

Keywords: Doublet; Single-character; Classification for character usage; Expressive morphology; Word creation; The Book of Poetry
Di Jiang*  

Editorial

28 July 2023

Review

28 July 2023

Challenging Post-translational Modifications in the Cell-free Protein Synthesis System

Post-translational modifications (PTMs) represent a cornerstone in the complexity of the proteome, significantly contributing to diversifying protein structure and function. PTMs can considerably influence protein function, stability, localization, and interactions with other molecules. Therefore, it is important when choosing a protein expression system to ensure the precise incorporation of PTMs during protein synthesis, which is paramount for producing biologically active proteins. The cell-free protein synthesis (CFPS) system has emerged as a powerful protein synthesis platform and research toolkit in synthetic biology. The open nature of the system allows the reaction environment to be tailored to any protein of interest to promote specific PTMs, thus allowing for the production of a protein with desired modifications. This review presents various PTMs achieved in the CFPS systems, providing insights into current challenges, successes, and future prospects.

Keywords: Cell-free protein synthesis; Post-translational modification; Biomanufacturing; Disulfide bonds; Glycosylation

Review

24 July 2023

Creating Shape Memory Polymers from Biobased Resources

Developing polymer materials from biomass is a promising pathway to address serious environmental and resource issues. To date, a series of biobased general polymer materials have been successfully industrialized. However, exploring highly valuable functional polymers and intelligent polymer materials from biomass, such as shape memory polymers (SMPs) and self-healing materials, is still a great challenge. The present review intends to bridge a sustainable pathway for the creation of SMPs from biobased resources. Thus, we first recall some backgrounds of the design principle of SMPs and highlight the biobased monomers or building blocks for SMPs, and then we focus on the main varieties of biobased SMPs to clarify their fabricating approaches, functionalizing strategies, new manufacturing methods and the application potential.

Keywords: Shape memory polymer; Biobased; Vitrimers; Polyesters; 4D printing

Article

20 July 2023

Fine-scale Genetic Structure of Geographically Distinct Patrilineal Lineages Delineates Southward Migration Routes for Han Chinese

The Han Chinese (HAN) represent the world’s largest ethnic group, and their genetic structure has been the focus of numerous studies. Yet previous studies failed to draw out finer population stratification of patrilineal HAN, due to limitations in sample size and genetic marker density. This essay employs a Y-haplogroup frequency dataset from virtually whole China aiming to draw out a detailed genetic structure of the patrilineal HAN. We provide an overview of the Y chromosome haplogroup distributions, and find that the patrilineal HAN can be divided into five geographic subgroups. Analysis of Molecular Variance (AMOVA) provided further support for the five-substructure model. By comparing patrilineal and matrilineal descent, we revealed stronger geographical aggregation for patrilineal HAN. Moreover, populations with patrilineal descent showed lower levels of haplogroup diversity (HD) compared to those with matrilineal descent, suggesting potential population bottleneck of patrilineal HAN. The larger HD among northern patrilines verified historical migration of HAN from north to south, which validated by neighbor joining tree (NJ-tree). Overall, we speculate the southward migration routes for Han Chinese, and the HAN south of the Nanling Mountains may have entered via the middle reaches of the Yangtze River, rather than via eastern coastal provinces.

Keywords: Y chromosome haplogroup; Han Chinese; Population genetics; Genetic structure; Sex bias

Article

19 July 2023

Hydroxybenzoic Acid Production Using Metabolically Engineered Corynebacterium glutamicum

Hydroxybenzoic acids (HBAs), including 4-HBA, 3-HBA, and 2-HBA, are valuable platform chemicals for production of commodity materials and fine chemicals. Herein, we employed metabolic engineering techniques to enhance the production of these HBAs in Corynebacterium glutamicum ATCC 13032. Our approach augmented the shikimate pathway and eliminated genes associated with HBA degradation, particularly phenol 2-monooxygenase encoded by cg2966. Increased titers of 3-HBA and 4-HBA were achieved via selection of suitable promoters for 3-hydroxybenzoate synthase and chorismate pyruvate lyase. A tac-M1 promoter was suitable for chorismate pyruvate lyase expression and 8.3 g/L of 4-HBA production was achieved. Efficient production of 2-HBA was enabled by maintaining a balanced expression of isochorismate synthase and isochorismate pyruvate lyase. Consequently, strains KSD5-tacM1-H and KSD5-J2-PE exhibited production levels of 19.2 g/L of 3-HBA and 12.9 g/L of 2-HBA, respectively, using 1 L jar fermenter containing 80 g/L of glucose. Therefore, this engineered strain platform holds significant potential for production of other valuable products derived from chorismate.

Keywords: Corynebacterium glutamicum; Hydroxybenzoic acid; 2-hydroxybenzoic acid; 3-hydroxybenzoic acid; Metabolic engineering; Chorismate derivatives
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