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1.
J Microbiol Biotechnol ; 34(7): 1475-1483, 2024 May 23.
Article in English | MEDLINE | ID: mdl-38973386

ABSTRACT

Three Gram-stain-positive, aerobic, rod-shaped, and non-motile bacteria, labelled as W11T , SW19T , and YR1T , were isolated from soil, and performed their polyphasic taxonomic investigation. The phylogenetic and 16S rRNA gene sequence analysis showed that strains W11T, SW19T, and YR1T belonged to the genera Agromyces, Rathayibacter, and Nocardioides, respectively. Strain W11T was closely affiliated with Agromyces cavernae SYSU K20354T (98.1%), strain SW19T showed the closest affiliation with Rathayibacter rubneri ZW T2_19T (97.0%), and strain YR1T was most closely related to Nocardioides marmorisolisilvae KIS18-7T (98.0%). The genome sizes of strains W11T , SW19T , and YR1T were 4,181,720 bp, 4,740,677 bp, and 4,228,226 bp, respectively, with DNA G+C contents of 70.5%, 64.2%, and 69.7%, respectively. Average nucleotide identity and digital DNA-DNA hybridization values of W11T , SW19T , and YR1T with their respective reference species were <79.6% and <23.6%, respectively. The predominant cellular fatty acids detected in strain W11T were anteiso-C15:0, isoC16:0, and anteiso-C17:0. In strain SW19T , they were summed feature 9 (C16:0 10-methyl and/or isoC17:1ω 9c), anteiso-C17:0, and anteiso-C15:0. Strain YR1T exhibited C18:1ω 9c, C18:0 10-methyl, TBSA, and anteiso-C15:0 as its major cellular fatty acids. Overall, the polyphasic taxonomic comparisons indicated that strains W11T , SW19T , and YR1T represent novel species within the genera Agromyces, Rathayibacter, and Nocardioides, respectively. Accordingly, we propose the names Agromyces silvae sp. nov., with the type strain W11T (=KCTC 49818T =NBRC 115999T ), Rathayibacter soli sp. nov., with the type strain SW19T (=KCTC 49860T =NBRC 116108T ), and Nocardioides terrisoli sp. nov., with the type strain YR1T (=KCTC 49863T =NBRC 116165T ).

2.
Dalton Trans ; 2024 Jun 20.
Article in English | MEDLINE | ID: mdl-38898716

ABSTRACT

A thiophene-derived Schiff base ligand (E)-2-morpholino-N-(thiophen-2-ylmethylene)ethanamine was used for the synthesis of M(II) complexes, [TEM(M)X2] (M = Co, Cu, Zn; X = Cl; M = Cd, X = Br). Structural characterization of the synthesized complexes revealed distorted tetrahedral geometry around the M(II) center. In vitro investigation of the synthesized ligand and its M(II) complexes showed considerable anti-urease and leishmanicidal potential. The synthesized complexes also exhibited a significant inhibitory effect on urease, with IC50 values in the range of 3.50-8.05 µM. In addition, the docking results were consistent with the experimental results. A preliminary study of human colorectal cancer (HCT), hepatic cancer (HepG2), and breast cancer (MCF-7) cell lines showed marked anticancer activities of these complexes.

3.
Front Public Health ; 12: 1386495, 2024.
Article in English | MEDLINE | ID: mdl-38827618

ABSTRACT

Introduction: Mitigating the spread of infectious diseases is of paramount concern for societal safety, necessitating the development of effective intervention measures. Epidemic simulation is widely used to evaluate the efficacy of such measures, but realistic simulation environments are crucial for meaningful insights. Despite the common use of contact-tracing data to construct realistic networks, they have inherent limitations. This study explores reconstructing simulation networks using link prediction methods as an alternative approach. Methods: The primary objective of this study is to assess the effectiveness of intervention measures on the reconstructed network, focusing on the 2015 MERS-CoV outbreak in South Korea. Contact-tracing data were acquired, and simulation networks were reconstructed using the graph autoencoder (GAE)-based link prediction method. A scale-free (SF) network was employed for comparison purposes. Epidemic simulations were conducted to evaluate three intervention strategies: Mass Quarantine (MQ), Isolation, and Isolation combined with Acquaintance Quarantine (AQ + Isolation). Results: Simulation results showed that AQ + Isolation was the most effective intervention on the GAE network, resulting in consistent epidemic curves due to high clustering coefficients. Conversely, MQ and AQ + Isolation were highly effective on the SF network, attributed to its low clustering coefficient and intervention sensitivity. Isolation alone exhibited reduced effectiveness. These findings emphasize the significant impact of network structure on intervention outcomes and suggest a potential overestimation of effectiveness in SF networks. Additionally, they highlight the complementary use of link prediction methods. Discussion: This innovative methodology provides inspiration for enhancing simulation environments in future endeavors. It also offers valuable insights for informing public health decision-making processes, emphasizing the importance of realistic simulation environments and the potential of link prediction methods.


Subject(s)
Contact Tracing , Coronavirus Infections , Disease Outbreaks , Middle East Respiratory Syndrome Coronavirus , Humans , Republic of Korea/epidemiology , Coronavirus Infections/transmission , Coronavirus Infections/prevention & control , Coronavirus Infections/epidemiology , Contact Tracing/methods , Disease Outbreaks/prevention & control , Quarantine , Computer Simulation
4.
Article in English | MEDLINE | ID: mdl-38743058

ABSTRACT

Two strictly aerobic and rod-shaped bacteria, labelled as DB1703T and DB2414ST, were obtained from an automobile air conditioning system. Strain DB1703T was Gram-stain-negative, while strain DB2414ST was Gram-stain-positive. Both strains were catalase-positive and oxidase-negative. Strains DB1703T and DB2414ST were able to grow at 18-42 °C. Strain DB1703T grew within a NaCl range of 0-3 % and a pH range of 6.0-8.0; while strain DB2414ST grew at 0-1 % and pH 6.5-8.5. The phylogenetic and 16S rRNA gene sequence analysis indicated that strains DB1703T and DB2414ST belonged to the genera Enterovirga and Knoellia, respectively. Strain DB1703T showed the closest phylogenetic similarity to Enterovirga rhinocerotis YIM 100770T (94.8 %), whereas strain DB2414ST was most closely related to Knoellia remsis ATCC BAA-1496T (97.7 %). The genome sizes of strains DB1703T and DB2414ST were 4 652 148 and 4 282 418 bp, respectively, with DNA G+C contents of 68.8 and 70.5 mol%, respectively. Chemotaxonomic data showed Q-10 as the sole ubiquinone in DB1703T and ML-8 (H4) in DB2414ST. The predominant cellular fatty acid in DB1703T was summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c), whereas iso-C16 : 0, C17 : 1 ω8c, and iso-C15 : 0 were dominant in DB2414ST. Overall, the polyphasic taxonomic comparisons showed that strains DB1703T and DB2414ST were distinct from their closest taxa and represent novel species within the genera Enterovirga and Knoellia, respectively. Accordingly, we propose the names Enterovirga aerilata sp. nov., with the type strain DB1703T (=KCTC 72724T=NBRC 114759T), and Knoellia koreensis sp. nov., with the type strain DB2414ST (=KCTC 49355T=NBRC 114620T).


Subject(s)
Air Conditioning , Automobiles , Bacterial Typing Techniques , Base Composition , DNA, Bacterial , Fatty Acids , Phylogeny , RNA, Ribosomal, 16S , Sequence Analysis, DNA , Ubiquinone , Fatty Acids/analysis , RNA, Ribosomal, 16S/genetics , DNA, Bacterial/genetics , Republic of Korea
5.
Front Public Health ; 12: 1362909, 2024.
Article in English | MEDLINE | ID: mdl-38515590

ABSTRACT

Introduction: Quantifying the transmissibility over time, particularly by region and age, using parameters such as serial interval and time-varying reproduction number, helps in formulating targeted interventions. Moreover, considering the impact of geographical factors on transmission provides valuable insights into the effectiveness of control measures. Methods: Drawing on a comprehensive dataset of COVID-19 cases in South Korea, we analyzed transmission dynamics with a focus on age and regional variations. The dataset, compiled through the efforts of dedicated epidemiologists, includes information on symptom onset dates, enabling detailed investigations. The pandemic was divided into distinct phases, aligning with changes in policies, emergence of variants, and vaccination efforts. We analyzed various interventions such as social distancing, vaccination rates, school closures, and population density. Key parameters like serial interval, heatmaps, and time-varying reproduction numbers were used to quantify age and region-specific transmission trends. Results: Analysis of transmission pairs within age groups highlighted the significant impact of school closure policies on the spread among individuals aged 0-19. This analysis also shed light on transmission dynamics within familial and educational settings. Changes in confirmed cases over time revealed a decrease in spread among individuals aged 65 and older, attributed to higher vaccination rates. Conversely, densely populated metropolitan areas experienced an increase in confirmed cases. Examination of time-varying reproduction numbers by region uncovered heterogeneity in transmission patterns, with regions implementing strict social distancing measures showing both increased confirmed cases and delayed spread, indicating the effectiveness of these policies. Discussion: Our findings underscore the importance of evaluating and tailoring epidemic control policies based on key COVID-19 parameters. The analysis of social distancing measures, school closures, and vaccine impact provides valuable insights into controlling transmission. By quantifying the impact of these interventions on different age groups and regions, we contribute to the ongoing efforts to combat the COVID-19 pandemic effectively.


Subject(s)
COVID-19 , Humans , COVID-19/epidemiology , COVID-19/prevention & control , Pandemics/prevention & control , SARS-CoV-2 , Republic of Korea/epidemiology , Policy
6.
Arch Microbiol ; 206(3): 119, 2024 Feb 23.
Article in English | MEDLINE | ID: mdl-38396312

ABSTRACT

An aerobic bacterium, designated as PT-12T, was isolated from soil collected from agriculture field, and its taxonomic position was validated through a comprehensive polyphasic methodology. The strain was identified as Gram-stain-negative, non-motile, rod-shaped, and catalase- and oxidase-positive. The yellow-colored colonies showed growth ability at temperature range of 18-37 °C, NaCl content of 0-1.0% (w/v), and at a pH of 6.0-8.0. The 16S rRNA gene and phylogenetic analysis showed that strain PT-12T affiliated with the genus Sphingomonas in the family Sphingomonadaceae, and displayed the highest 16S rRNA nucleotide sequence similarity with Sphingomonas limnosediminicola 03SUJ6T (98.4%). The genome size of strain PT-12T was 2,656,862 bp and the DNA G + C content estimated from genome was 63.5%. The highest values of average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) were observed between strain PT-12T and Sphingomonas segetis YJ09T, accounting to 76.2% and 20.2%, respectively. In addition, both ANI and dDDH values between strain PT-12T and other phylogenetically related neighbors ranged between 69.6% and 76.2% and 18.4% and 20.2%, respectively. Chemotaxonomic features exhibited Q-10 as the only ubiquinone; homospermidine as the major polyamine; summed feature 8 (C18:1ω7c and/or C18:1ω6c), C16:0, and 10-methyl C18:0 as the notable fatty acids; and phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine, and sphingoglycolipid as dominating polar lipids. Overall, the comprehensive polyphasic data supported that strain PT-12T represents a novel bacterial species within the genus Sphingomonas. Accordingly, we propose the name Sphingomonas flavescens sp. nov. The type strain is PT-12T (= KCTC 92114T = NBRC 115717T).


Subject(s)
Phospholipids , Sphingomonas , Phospholipids/chemistry , Sphingomonas/genetics , Phylogeny , RNA, Ribosomal, 16S/genetics , Soil , Bacterial Typing Techniques , DNA, Bacterial/genetics , Spermidine , Soil Microbiology , Fatty Acids/chemistry , Sequence Analysis, DNA
7.
Arch Microbiol ; 206(1): 42, 2023 Dec 26.
Article in English | MEDLINE | ID: mdl-38147140

ABSTRACT

During the study of microbial ecology of forest soil, two circular, white-colored bacterial colonies were isolated and labeled as strains TW38T and TW40T. Both strains were catalase positive and oxidase negative. Strains TW38T and TW40T demonstrated growth within a temperature range of 10-37 °C and 18-37 °C, respectively, and thrived within a pH range of 5.5-9.0 and 6.0-8.0, respectively. Both strains grew at 0-2.0% (w/v) NaCl concentrations. The phylogenetic analysis indicated that strains TW38T and TW40T affiliated to the genus Paenibacillus, with the closest neighbors being Paenibacillus montanisoli RA17T (98.6%) and Paenibacillus arachidis E3T (95.4%), respectively. In both strains, the sole respiratory quinone was MK-7, the signature fatty acid was antiso-C15:0, and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and phosphatidylcholine. The digital DNA-DNA hybridization and the average nucleotide identity values between TW38T, TW40T, and closest reference strains were < 29.0% and < 85.0%, respectively. The DNA G+C content of TW38T and TW40T was 54.5% and 57.1%, respectively. In general, the phylogenetic, genomics, chemotaxonomic, and phenotypic data support the differentiation of TW38T and TW40T from other closest members of the genus Paenibacillus. Thus, we conclude both strains TW38T and TW40T represent novel species of the genus Paenibacillus, for which the name Paenibacillus silvisoli sp. nov. and Paenibacillus humicola sp. nov. are proposed, respectively. The type strain of Paenibacillus silvisoli is TW38T (= KCTC 43468T = NBRC 116015T) and type strain of Paenibacillus humicola is TW40T (= KCTC 43469T = NBRC 116016T).


Subject(s)
Cardiolipins , Paenibacillus , Phylogeny , Forests , Paenibacillus/genetics , DNA
8.
Int J Syst Evol Microbiol ; 73(11)2023 Nov.
Article in English | MEDLINE | ID: mdl-37982814

ABSTRACT

A milky-white-coloured, aerobic, Gram-stain-positive, rod-shaped and motile bacterial strain (GW78T) was isolated from forest soil. GW78T was catalase-positive and oxidase-negative. The strain was able to grow optimally at 37 °C and at pH 7.0 in Reasoner's 2A media. The phylogenetic and 16S rRNA gene sequence analysis of GW78T showed its affiliation with the genus Paenibacillus. The 16S rRNA gene sequence of GW78T revealed 98.3 % similarity to its nearest neighbour Paenibacillus mucilaginosus VKPM B-7519T. Its chemotaxonomic properties included MK-7 as the sole menaquinone, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylmonomethylethanolamine and phosphatidylethanolamine as major polar lipids, and anteiso-C15 : 0, C16 : 1 ω11c and anteiso-C17 : 0 as predominant fatty acids. Digital DNA-DNA hybridization and average nucleotide identity results with its closest relatives were <74.0 % and <14.0 %, respectively. Overall, 16S rRNA gene sequence comparisons, phylogenetic and genomic evidence, and phenotypic and chemotaxonomic data allow the differentiation of GW78T from other members of the genus Paenibacillus. Thus, we propose that strain GW78T represents a novel species of the genus Paenibacillus, with the name Paenibacillus caseinilyticus sp. nov. The type strain is GW78T (=KCTC 43430T=NBRC 116023T).


Subject(s)
Fatty Acids , Paenibacillus , Fatty Acids/chemistry , Phospholipids/chemistry , Phylogeny , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Base Composition , DNA, Bacterial/genetics , Bacterial Typing Techniques , Soil Microbiology , Forests
9.
J Phys Chem Lett ; 14(44): 9811-9818, 2023 Nov 09.
Article in English | MEDLINE | ID: mdl-37889127

ABSTRACT

The increasing use of plastics has led to the accumulation of plastic waste in the oceans, resulting in significant global environmental challenges associated with microplastic pollution. Micromotors, capable of capturing and removing microplastics from aquatic systems, have emerged as a promising solution to addressing this problem. This research aims to analyze the factors affecting the speed of micromotors, including size, morphology, and surface structure, while elucidating the underlying mechanisms governing micromotor propulsion to develop efficient and ecofriendly micromotors. In this study, we systematically manipulate various parameters by modifying the synthesis method of hematite-based micromotors, subsequently comparing their propulsion speeds and uncovering the precise role of these parameters in determining the micromotor performance. Furthermore, we shed light on the intricate interplay between drag force and propulsive force, demonstrating how these forces vary under different H2O2 conditions. These findings provide valuable insights into the design of efficient micromotors tailored for dynamic aquatic environments.

10.
RSC Adv ; 13(44): 31092-31100, 2023 Oct 18.
Article in English | MEDLINE | ID: mdl-37881755

ABSTRACT

Control of polymer topologies is essential to determine their unique physical properties and potential applications. The polymer topologies can have a critical effect on pigment dispersion owing to their unique architectures; however, studies using polymer topologies on pigment dispersion in aqueous systems are scarce. Thus, this study proposes various topologies of polyether-based waterborne synergists, such as linear, hyperbranched, and branched cyclic structures. Specifically, we applied branched types of polyglycidols (PGs) as a synergist to provide polymer topology-dependent dispersibility for the surface-modification of Red 170 particles through adsorption and steric hindrance. The topology-controlled PG synergists (PGSs) were successfully prepared by post-polymerization modification with phthalimide and benzoyl groups. Particularly, the branched types of PGSs, branched cyclic PGS (bc-PGS), and hyperbranched PGS (hb-PGS) exhibited improved dispersibility through adsorption on top of the pigment, interaction between dispersant (BYK 190) and pigment, and steric effect. Surprisingly, hb-PGS conferred the Red 170 pigment particles with superior storage stability than that of bc-PGS despite their similar structural features. This study suggests the widespread potential application of PGSs as waterborne synergists for various dispersion applications.

11.
Dalton Trans ; 52(45): 16802-16811, 2023 Nov 21.
Article in English | MEDLINE | ID: mdl-37902974

ABSTRACT

Here, we report a series of four novel Cu complexes, namely 2-(piperidin-1-ylmethyl)quinoline copper(II) nitrate, [LACu(NO3)2] (Cu1), 4-(quinolin-2-ylmethyl)morpholine copper(II) nitrate, [LBCu(NO3)2] (Cu2), 4-(quinolin-2-ylmethyl)morpholine copper(II) chloride, [LBCuCl2] (Cu3), and 2-(piperidin-1-ylmethyl)pyridine copper(II) chloride, [LCCu(µ-Cl)Cl]2 (Cu4). X-ray diffraction studies revealed that the geometry around the Cu(II) center could be best described as distorted octahedral in Cu1 and Cu2, whereas Cu3 and Cu4 showed distorted tetrahedral and square pyramidal geometries, respectively. DNA binding studies showed that Cu complexes Cu1-3 containing quinoline interacted via minor groove binding, whereas the Cu4 complex containing pyridine interacted via intercalation. All Cu complexes containing quinoline and pyridine caused destabilization of DNA at specific homogeneous G-C regions. The Cu1-3 complexes as groove binders destabilized the DNA structure much more than the Cu4 complex as an intercalator. Regarding groove binders, the Cu2 complex containing quinoline and morpholine caused the highest distortion and destabilization of the DNA structure, leading to high DNA cleavage efficiency.


Subject(s)
Copper , Quinolines , Copper/chemistry , DNA/chemistry , Deoxyribonucleases , Pyridines , Morpholines , Crystallography, X-Ray
12.
Arch Microbiol ; 205(6): 248, 2023 May 26.
Article in English | MEDLINE | ID: mdl-37233801

ABSTRACT

A white-coloured, rod-shaped, motile, aerobic, and Gram-stain-positive bacterial strain S3N08T was isolated from agricultural soil. The strain grew at temperature 10-40 °C, at 0-1.0% (w/v) NaCl concentration, and at pH 6.5-8.0. Catalase was negative and oxidase was positive. The phylogenetic analysis inferred that the strain S3N08T belonged to the genus Paenibacillus, with the closest relative being Paenibacillus periandrae PM10T (95.6% 16S rRNA gene sequence similarity). The only menaquinone was MK-7 and the major polar lipids were phosphatidylmonomethylethanolamine, phosphatidylglycerol, and phosphatidylethanolamine. The predominant fatty acids were antiso-C15:0, C16:0, and iso-C15:0. The DNA G + C content was 45.1%. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain S3N08T and with closest members were < 72.0% and < 19.0%, respectively. Altogether, the phylogenetic, genomics, phenotypic, and chemotaxonomic evidence illustrated in this study suggested that strain S3N08T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus agricola sp. nov. is proposed. The type strain is S3N08T (= KACC 19666 T = NBRC 113430 T).


Subject(s)
Paenibacillus , Phospholipids , Phospholipids/chemistry , Soil , Phylogeny , RNA, Ribosomal, 16S/genetics , DNA, Bacterial/genetics , Sequence Analysis, DNA , Soil Microbiology , Bacterial Typing Techniques , Diaminopimelic Acid/chemistry , Fatty Acids/chemistry
13.
ACS Omega ; 8(20): 17620-17633, 2023 May 23.
Article in English | MEDLINE | ID: mdl-37251197

ABSTRACT

Novel thiophene-derived Schiff base ligand DE, where DE is (E)-N1,N1-diethyl-N2-(thiophen-2-ylmethylene)ethane-1,2-diamine, and the corresponding M(II) complexes, [M(DE)X2] (M = Cu or Zn, X = Cl; M = Cd, X = Br), were prepared and structurally characterized. X-ray diffraction studies revealed that the geometry around the center of the M(II) complexes, [Zn(DE)Cl2] and [Cd(DE)Br2], could be best described as a distorted tetrahedral. In vitro antimicrobial screening of DE and its corresponding M(II) complexes, [M(DE)X2], was performed. The complexes were more potent and showed higher activities against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa, fungi Candida albicans, and protozoa Leishmania major compared to the ligand. Among the studied complexes, [Cd(DE)Br2] exhibited the most promising antimicrobial activity against all the tested microbes compared to its analogs. These results were further supported by molecular docking studies. We believe that these complexes may significantly contribute to the efficient designing of metal-derived agents to treat microbial infections.

14.
J Microbiol Biotechnol ; 33(7): 909-914, 2023 Jul 28.
Article in English | MEDLINE | ID: mdl-37100761

ABSTRACT

While searching for the bacteria which are responsible for degradation of pesticide in soybean field soil, a novel bacterial strain, designated 5-5T, was isolated. The cells of the strain were Gram-staining-positive, aerobic and non-motile rods. Growth occurred at 10-42oC (optimum, 30oC), pH 5.5-9.0 (optimum, pH 7.0-7.5), and 0-2% (w/v) NaCl (optimum, 1%). The predominant fatty acids were C15:0 anteiso, C17:0 anteiso, and summed feature 8 (C18:1 ω7c and/or C18:1 ω6c). The predominant menaquinone was MK-9 (H2). Diphosphatidylglycerol, glycolipids, phosphatidylinositol, and phosphatidylglycerol were the major polar lipids. Phylogenetic analysis of 16S rRNA gene sequences indicated that strain 5-5T is a member of the genus Sinomonas and its closest relative is Sinomonas humi MUSC 117T, sharing a genetic similarity of 98.4%. The draft genome of strain 5-5T was 4,727,205 bp long with an N50 contig of 4,464,284 bp. Genomic DNA G+C content of strain 5-5T was 68.0 mol%. The average nucleotide identity (ANI) values between strain 5-5T and its closest strains S. humi MUSC 117T and S. susongensis A31T were 87.0, and 84.3 % respectively. In silico DNA-DNA hybridization values between strain 5-5T and its closest strains S. humi MUSC 117T and S. susongensis A31T were 32.5% and 27.9% respectively. Based on the ANI and in silico DNA-DNA hybridization analyses, the 5-5T strain was considered as novel species belonging to the genus Sinomonas. On the basis of the results from phenotypic, genotypic and chemotaxonomic analyses, strain 5-5T represents a novel species of the genus Sinomonas, for which the name Sinomonas terrae sp. nov. is proposed. The type strain is 5-5T (=KCTC 49650T=NBRC 115790T).


Subject(s)
Soil Microbiology , Soil , Phylogeny , RNA, Ribosomal, 16S/genetics , DNA, Bacterial/genetics , DNA, Bacterial/chemistry , Fatty Acids/analysis , Sequence Analysis, DNA , Bacterial Typing Techniques , Phospholipids/chemistry
15.
ACS Omega ; 8(6): 6016-6029, 2023 Feb 14.
Article in English | MEDLINE | ID: mdl-36816644

ABSTRACT

Zn(II), Pd(II), and Cd(II) complexes, [L TH MCl 2 ] (M = Zn, Pd; X = Br, Cl) and [L TH Cd(µ-X)X] n (X = Cl, Br; n = n, 2), supported by the (E)-N 1,N 1-dimethyl-N 2-(thiophen-2-ylmethylene)ethane-1,2-diamine (L TH ) ligand are synthesized and structurally characterized. Density functional theory (DFT) electronic structure calculations and variable-temperature NMR support the presence of two conformers and a dynamic interconversion process of the minor conformer to the major one in solution. It is found that the existence of two relevant complex conformers and their respective ratios in solution depend on the central metal ions and counter ions, either Cl- or Br-. Among the two relevant conformers, a single conformer is crystallized and X-ray diffraction analysis revealed a distorted tetrahedral geometry for Zn(II) complexes, and a distorted square planar and square pyramidal geometry for Pd(II) and Cd(II) complexes, respectively. It is shown that [L TH MCl 2 ]/LiO i Pr (M = Zn, Pd) and [L TH Cd(µ-Cl)Cl] n /LiO i Pr can effectively catalyze the ring-opening polymerization (ROP) reaction of rac-lactide (rac-LA) with 94% conversion within 30 s with [L TH ZnCl 2 ]/LiO i Pr at 0 °C. Overall, hetero-enriched poly(lactic acid)s (PLAs) were provided by these catalytic systems with [L TH ZnCl 2 ]/LiO i Pr producing PLA with higher heterotactic bias (P r up to 0.74 at 0 °C).

16.
Medicine (Baltimore) ; 101(44): e31413, 2022 Nov 04.
Article in English | MEDLINE | ID: mdl-36343059

ABSTRACT

The prevalence of chronic obstructive pulmonary disease (COPD) is increasing worldwide, with the fourth highest mortality rate. This study aims to analyze pulmonary function, physical activity, and quality of life (QoL) between genders from the perspective of pulmonary rehabilitation in Korean patients with COPD. This study investigated raw data from the Korea National Health and Nutrition Examination Survey from 2015 to 2019 and included 151 COPD patients (men: 66.55 ±â€…10.07 years, women: 65.21 ±â€…11.73) out of 39,759 participants. Pulmonary function, such as forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1), and frequency of physical activities (e.g., physical activity for work and leisure, strengthening exercise, and sitting time a day) and QoL by using EQ-5D-3L, were compared between genders in patients with COPD. Smoking status differed in health-related characteristics between genders (P < .001). In pulmonary function, the FVC (men: 3.48 ±â€…0.98ℓ, women: 2.53 ±â€…0.56ℓ, P < .05), FEV1 (men: 2.13 ±â€…0.93 ℓ, women: 1.88 ±â€…0.53 ℓ, P < .001), FEV6 (men: 3.16 ±â€…1.00ℓ, women: 2.46 ±â€…1.56ℓ, P < .001) and peak expiratory flow (men: 5.61 ±â€…2.44ℓ/s, women: 4.68 ±â€…1.53ℓ/s, P < .05) was higher in men, however, predicted FEV1 (men: 66.03% ±â€…23.13%, women: 79.95% ±â€…18.45%, P < .05) and predicted FEV1/FVC ratio (men: 59.67% ±â€…15.02%, women: 74.10% ±â€…10.49%, P < .001) in women. The frequency of strengthening exercise was higher in men (P < .05). QoL of patients with COPD was not significantly different between genders. To provide correct interventions and pulmonary rehabilitation to patients with COPD, gender differences, including physiological and psychological differences, must be considered.


Subject(s)
Pulmonary Disease, Chronic Obstructive , Quality of Life , Humans , Female , Male , Quality of Life/psychology , Forced Expiratory Volume/physiology , Nutrition Surveys , Sex Factors , Vital Capacity/physiology , Republic of Korea/epidemiology , Exercise
17.
PLoS One ; 17(11): e0277813, 2022.
Article in English | MEDLINE | ID: mdl-36409713

ABSTRACT

The increasing traffic demand in urban areas frequently causes traffic congestion, which can be managed only through intelligent traffic signal controls. Although many recent studies have focused on reinforcement learning for traffic signal control (RL-TSC), most have focused on improving performance from an intersection perspective, targeting virtual simulation. The performance indexes from intersection perspectives are averaged by the weighted traffic flow; therefore, if the balance of each movement is not considered, the green time may be overly concentrated on the movements of heavy flow rates. Furthermore, as the ultimate purpose of traffic signal control research is to apply these controls to the real-world intersections, it is necessary to consider the real-world constraints. Hence, this study aims to design RL-TSC considering real-world applicability and confirm the appropriate design of the reward function. The limitations of the detector in the real world and the dual-ring traffic signal system are taken into account in the model design to facilitate real-world application. To design the reward for balancing traffic movements, we define the average delay weighted by traffic volume per lane and entropy of delay in the reward function. Model training is performed at the prototype intersection for ensuring scalability to multiple intersections. The model after prototype pre-training is evaluated by applying it to a network with two intersections without additional training. As a result, the reward function considering the equality of traffic movements shows the best performance. The proposed model reduces the average delay by more than 7.4% and 15.0% compared to the existing real-time adaptive signal control at two intersections, respectively.


Subject(s)
Reward , Computer Simulation
18.
J Phys Chem Lett ; 13(40): 9435-9448, 2022 Oct 13.
Article in English | MEDLINE | ID: mdl-36194546

ABSTRACT

Understanding the role of energy dissipation and charge transfer under exothermic chemical reactions on metal catalyst surfaces is important for elucidating the fundamental phenomena at solid-gas and solid-liquid interfaces. Recently, many surface chemistry studies have been conducted on the solid-liquid interface, so correlating electronic excitation in the liquid-phase with the reaction mechanism plays a crucial role in heterogeneous catalysis. In this review, we introduce the detection principle of electron transfer at the solid-liquid interface by developing cutting-edge technologies with metal-semiconductor Schottky nanodiodes. The kinetics of hot electron excitation are well correlated with the reaction rates, demonstrating that the operando method for understanding nonadiabatic interactions is helpful in studying the reaction mechanism of surface molecular processes. In addition to the detection of hot electrons excited by a catalytic reaction, we highlight recent results on how the transfer of the hot electrons influences surface chemical and photoelectrochemical reactions.

19.
RSC Adv ; 12(55): 35896-35904, 2022 Dec 12.
Article in English | MEDLINE | ID: mdl-36605356

ABSTRACT

A series of Co(ii) complexes supported by Schiff base ligands, LA-LC, where LA, LB, and LC are (E)-3-methoxy-N-(quinolin-2-ylmethylene)propan-1-amine, (E)-N 1,N 1-dimethyl-N 2-(pyridin-2-ylmethylene)ethane-1,2-diamine, and (E)-N 1,N 1-dimethyl-N 2-(thiophen-2-ylmethylene)ethane-1,2-diamine, respectively, were designed and synthesized. Structural studies revealed a distorted trigonal bipyramidal geometry for [LBCoCl2] and a distorted tetrahedral geometry for [LCCoCl2]. After activation with modified methyl aluminoxane (MMAO), all the Co(ii) complexes catalyzed the polymerization of norbornene (NB) to yield vinyl-type polynorbornenes (PNBs) with activities of up to 4.69 × 104 gPNB mol Co-1 h-1 at 25 °C. High-molecular-weight (M n of up to 1.71 × 105 g mol-1) soluble PNBs with moderate molecular-weight distributions (MWD) were obtained. The activity of the Co(ii)/MMAO catalytic system is influenced by the steric hindrance and electronic properties of the ligands.

20.
Medicine (Baltimore) ; 101(52): e31915, 2022 Dec 30.
Article in English | MEDLINE | ID: mdl-36595990

ABSTRACT

Appropriate trunk muscle activity is needed to perform functional activities in cerebral palsy, this study analyzed the activity of trunk muscles during horseback riding machine exercise in children with spastic cerebral palsy. 10 children with spastic cerebral palsy were participated, the activity of the trunk muscles, including both sides of the rectus abdominis, external oblique, latissimus dorsi, and erector spinae in sitting posture and during horseback riding machine exercise were evaluated using a surface electromyography. The activity of bilateral rectus abdominis, external oblique, latissimus dorsi, and erector spinae increased during horseback riding machine exercise than quiet sitting posture. Moreover, there were significant differences in activities of the trunk muscles between the sitting posture and horseback riding machine exercise, with the exception of the left external oblique and the left latissimus dorsi. Horseback riding machine exercise provides more opportunities to use the trunk muscles for children with spastic cerebral palsy than general sitting posture. In future, it will be of use to investigate the effect of horseback riding machine exercise in patients with cerebral palsy.


Subject(s)
Cerebral Palsy , Humans , Child , Muscle, Skeletal/physiology , Torso/physiology , Exercise , Electromyography , Rectus Abdominis
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