Artiles
Perspective
07 March 2023Pulsed Ultraviolet C as a Potential Treatment for COVID-19
Currently, low dose radiotherapy (LDRT) is being tested for treating life-threatening pneumonia in COVID-19 patients. Despite the debates over the clinical use of LDRT, some clinical trials have been completed, and most are still ongoing. Ultraviolet C (UVC) irradiation has been proven to be highly efficient in inactivating the coronaviruses, yet is considerably safer than LDRT. This makes UVC an excellent candidate for treating COVID-19 infection, especially in case of severe pneumonia as well as the post COVID-19 pulmonary fibrosis. However, the major challenge in using UVC is its delivery to the lungs, the target organ of COVID-19, due to its low penetrability through biological tissues. We propose to overcome this challenge (i) by using pulsed UVC technologies which dramatically increase the penetrability of UVC through matter, and (ii) by integrating the pulsed UVC technologies into a laser bronchoscope, thus allowing UVC irradiation to reach deeper into the lungs. Although the exact characteristics of such a treatment should yet to be experimentally defined, this approach might be much safer and not less efficient than LDRT.
Article
03 March 2023Spatial Characteristics and Influencing Factors of Migration in Kanagawa, Japan
In the context of “Tokyo centralization”, population migration has become an important factor affecting Kanagawa's economic growth, living standards, and employment status. On the other hand, with the development of the declining birth rate and aging society, migration for any purpose has an impact on social development. The government has released many policies to attract people from other cities to Kanagawa. This study analyzes the factors influencing the spatial pattern of population migration in Kanagawa based on the current spatial characteristics of population migration in Kanagawa from 2016~2020 and previous population migra-tion research theories. the influencing factors are analyzed empirically by selecting a total of 9 economic, social, and environmental indicators that may affect the spatial pattern of population migration in Kanagawa. The result showed that, when only the economic factor was considered, gross prefectural product, job opportunities, and consumer price index significantly influenced migration; When only environmental factors are considered, the number of pollution complaints successfully handled had a significant positive effect on population migration; When only the social environment is considered, the level of education becomes the main consid-eration for people. Furthermore, when the economic factors, environmental factors, and social factors are analyzed together, the gross prefectural domestic product, job opportunities, consumer price index, and the number of pollution complaints successfully handled all have an impact on migration in Kanagawa and the gross prefectural product is the common influencing factor.
Article
03 March 2023SnS2 Quantum Dots Decorated MoS2 Nanosheets Enabling Efficient Photocatalytic H2 Evolution in CO2 Saturated Water
SnS2/MoS2 heterojunction nanocomposite was prepared by a one-step hydrothermal synthesis method. The nanocomposite exhibited much improved photocatalytic hydrogen evolution performance in CO2 saturated solution compared with pure MoS2 and SnS2 samples. The improved photocatalytic activity was attributed to the S-scheme heterojunction structure between SnS2 quantum dots and MoS2 nanosheets which facilitate electron-hole separation both in MoS2 and SnS2. In the S-scheme structure, the strong reduction ability of SnS2 quantum dots was well maintained for the improved H2 evolution. In situ DRIFT studies allowed us to suggest reaction pathways from CO2 and H2O to photocatalytic H2, CO, and CH4 generation.
Communication
03 March 2023Evaluating Different UAS Flight Methods for 3D Model Generation and Printing of a Tornado Destroyed Cultural Heritage: Caddo House in Texas
In recent years, the use of Unmanned Aerial Systems (UAS) to obtain imagery for photogrammetry has become commonplace. Using these data to develop 3D products has also grown significantly in both research and commercial applications. This study aims to find a relatively simple and low cost UAS flight method as a means to obtain data to produce a 3D model suitable for 3D printing. The study subject chosen to assess different flight methods was the Caddo House at Caddo Mounds State Historical Site located near Alto, Cherokee County, Texas, USA. To collect images for analysis, a DJI Phantom 4 Pro UAS was used. Pix4DCapture was used to fly the drone. Two main missions were carried out, one being a pre-defined double-grid flight, and the other being an orbital free-flight method. The findings of this study indicate that if the goal is to create a true-to-life 3D model of an object using UAS, the best method would be a curated orbital free-flight method. If there is time constraint and the subject is sufficiently large and not considerably irregular, a double-grid method with sufficient forward overlap and side overlap can produce desirable results, but with a slight loss of fine details. The 3D model developed from the curated orbital flight method was successfully printed with a customer grade FDM 3D printer.
Review
16 February 2023Increasing Nutritional Value of Cyanobacteria by Engineering Valine, Phenylalanine, and Fatty Acid Production
In 2020, the United Nations estimated that 2.37 billion people globally were without food or unable to eat a healthy balanced diet. The number of people with insufficient nutrition has increased in the short term due to COVID-19 pandemic and longer-term climate change is leading to shifts in arable land and water availability leading to a continued need to develop scalable sources of nutrition. One of the options that can yield high food mass per square foot of land use is the high-density culture of microalgae or other photosynthetic microorganisms. While photosynthetic microorganisms may provide high amounts of biomass with a small land footprint, the nutritional value of unmodified microorganisms may be limited. This mini-review presents the base nutritional value in terms of macro- and micronutrients of several cyanobacteria (Nostoc, Anabaena, Spirulina) in relation to established human nutritional requirements as a starting point for better utilization of cyanobacteria as nutritional supplements. It also discusses synthetic biology approaches that have been implemented in different organisms to increase the production of L-valine, L-phenylalanine, and fatty acids demonstrating some common genetic engineering design approaches and some approaches that are organism-specific.
Article
07 February 2023Production of Highly Modified C30-carotenoids with Singlet Oxygen-quenching Activities, 5-glucosyl-5,6-dihydro-4,4’-diapolycopen-4’-oic Acid, and Its Three Intermediates Using Genes from Planococcus maritimus Strain iso-3
Planococcus maritimus strain iso-3 was previously isolated from intertidal sediment in the North Sea and was found to produce a highly modified C30-carotenoid, methyl-5-glucosyl-5,6-dihydro-4,4’-diapolycopenoate, as the final product. In this study, we analyzed the function of the carotenoid terminal oxidase crtP (renamed cruO) and aldehyde dehydrogenase aldH genes in P. maritimus strain iso-3 and elucidated the carotenoid biosynthetic pathway for this strain at the gene level. We produced four novel C30-carotenoids with potent singlet oxygen-quenching activities, 5-glucosyl-5,6-dihydro-4,4’-diapolycopen-4’-oic acid and its three intermediates, which were obtained using E. coli cells carrying the cruO (and aldH) gene(s) in addition to the known P. maritimus carotenogenic genes.
Article
07 February 2023Plasmon Enhanced Nickel(II) Catalyst for Photocatalytic Lignin Model Cleavage
Photocatalytic-induced cleaving of the ether C–O bond in model lignin compounds was studied with a closely-coupled compo-site material consisting of Ni(OH)2 and gold nanoparticles (NPs) on a zirconia support (Au/ZrO2–Ni(OH)2). The three important ether bond types consisting of α-O-4, β-O-4, and 4-O-5 linkages can all be cleaved using this catalyst at reaction temperatures 40, 85 and 95 °C when under low-flux visible light irradiation. The Au NPs action as a light-harvesting antenna provided light-generated hot electrons that reduced Ni2+ to Ni0. The Ni0 was the active catalytic site where reductive cleavage of ether C–O bonds occurred while it was oxidized to Ni2+ to complete the catalysis cycle. The plasmonic antenna system with supported Ni(OH)2 exhibited better ability for the catalytic reductive ether cleavages under visible light irradiation compared to photocata-lysts of Au NPs and Ni2+ ions immobilized on alumina fibers.
Article
30 January 2023Metal-Free Lewis Pair Catalysts for a One-Pot Terpolymerization of Propylene Oxide, ʟ-Lactide and CO2
Multiblock and di-/tri-block copolymers are successfully synthesized for the first time via the metal-free terpolymerization of propylene oxide (PO), ʟ-lactide (LA) and CO2 in one-pot/one-step and one-pot/two-step protocols respectively. Firstly, triethyl borane (TEB) and bis(triphenylphosphine)iminium chloride (PPNCl) Lewis pair is employed in the ring-opening polymerization of LA, wherein the catalytic efficiency is significantly correlated to the TEB/PPNCl feed ratio. Next, a series of TEB/base pairs are selected to synthesize the PO/LA/CO2 terpolymer (PPCLA) in one-pot/one-step strategy. In PPCLA synthesis, LA exhibits the fastest reaction rate but the severe transesterification is almost unavoidable, resulting in low molecular weight products. In order to prepare high-molecular-weight terpolymers, a one-pot/two-step methodology has to be applied. By this method, the copolymerization of PO/CO2 proceeds first to form poly(propylene carbonate) (PPC) macroinitiators, which triggers the polymerization of LA to polylactide (PLA), leading to PLA-PPC or PLA-PPC-PLA block copolymers. The synthesized PLA-PPC-PLA block copolymers display an improved thermal stability compared with PPC.
Perspective
29 January 2023Carbon Neutrality and Life Cycle Thinking
Climate change is one of the most critical sustainability challenges facing the humanity. International communities have joined forces to mitigate climate change impact and aim to achieve carbon neutrality in the coming decades. To achieve this ambitious goal, life cycle thinking can play critical roles. Specifically, life cycle thinking helps evaluate the true climate impacts to avoid shifting emissions across processes in a product life cycle. It can also help inform consumers with carbon footprint information to make climate-conscious choices. Finally, it can help identify key processes dominating the carbon footprint of a product so that future improvement can set priorities. High quality data is required for accurate and timely carbon footprint accounting and critical challenges exist to obtain and share such data.
Article
28 January 2023Current Challenges to the Sustainable Development of Rural Communities in Russia's Central Chernozem Region
The rural community system in the Central Chernozem Economic Region in Russia is undergoing a radical transformation under the interrelated influence of fundamental factors that have rendered the development of many communities unsustainable. This paper analyses the role of urbanisation processes in population changes and transformation of rural community systems in the region; determines the level of horizontal mobility among the rural population, as well as its impact on settlement evolution; assesses the share of small and extremely small communities in settlement composition; and outlines these communities’ future development prospects. The authors believe that the socio-demographic “desertification” of peripheral municipalities can pose challenges to rural development: a shortage of labour resources, changes in population quality, and problems of innovation diffusion. The study recommends improving the comfort of the living environment and accelerating the technical re-equipment and automation of agricultural production.
