Examining the Effectiveness of Interactive Webtoons for Premature Birth Prevention: Protocol for a Randomized Controlled Trial.

BACKGROUND: Premature birth poses significant health challenges globally, impacting infants, families, and society. Despite recognition of its contributing factors, efforts to reduce its incidence have seen limited success. A notable gap exists in the awareness among women of childbearing age (WCA) regarding both the risks of premature birth and the preventative measures they can take. Research suggests that enhancing health beliefs and self-management efficacy in WCA could foster preventive health behaviors. Interactive webtoons offer an innovative, cost-effective avenue for delivering engaging, accessible health education aimed at preventing premature birth. OBJECTIVE: This protocol describes a randomized controlled trial to assess the effectiveness and feasibility of a novel, self-guided, web-based intervention-Pregnancy Story I Didn't Know in Interactive Webtoon Series (PSIDK-iWebtoons)-designed to enhance self-management efficacy and promote behaviors preventing premature birth in WCA. METHODS: Using an explanatory sequential mixed methods design, this study first conducts a quantitative analysis followed by a qualitative inquiry to evaluate outcomes and feasibility. Participants are randomly assigned to 2 groups: one accessing the PSIDK-iWebtoons and the other receiving Pregnancy Story I Didn't Know in Text-Based Information (PSIDK-Texts) over 3 weeks. We measure primary efficacy through the self-management self-efficacy scale for premature birth prevention (PBP), alongside secondary outcomes including perceptions of susceptibility, severity, benefits, and barriers based on the health belief model for PBP and PBP intention. Additional participant-reported outcomes are assessed at baseline, the postintervention time point, and the 4-week follow-up. The feasibility of the intervention is assessed after the end of the 3-week intervention period. Outcome analysis uses repeated measures ANOVA for quantitative data, while qualitative data are explored through content analysis of interviews with 30 participants. RESULTS: The study received funding in June 2021 and institutional review board approval in October 2023. Both the PSIDK-iWebtoons and PSIDK-Texts interventions have been developed and pilot-tested from July to November 2023, with the main phase of quantitative data collection running from November 2023 to March 2024. Qualitative data collection commenced in February 2024 and will conclude in May 2024. Ongoing analyses include process evaluation and data interpretation. CONCLUSIONS: This trial will lay foundational insights into the nexus of interactive web-based interventions and the improvement of knowledge and practices related to PBP among WCA. By demonstrating the efficacy and feasibility of a web-based, interactive educational tool, this study will contribute essential evidence to the discourse on accessible and scientifically robust digital platforms. Positive findings will underscore the importance of such interventions in fostering preventive health behaviors, thereby supporting community-wide efforts to mitigate the risk of premature births through informed self-management practices. TRIAL REGISTRATION: Korea Disease Control and Prevention Agency (KDCA) KCT0008931; https://cris.nih.go.kr/cris/search/detailSearch.do?seq=25857. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/58326.

Identification, Characterization, and Electronic Structures of Interconvertible Cobalt-Oxygen TAML Intermediates.

The reaction of Li[(TAML)CoIII]·3H2O (TAML = tetraamido macrocyclic tetraanionic ligand) with iodosylbenzene at 253 K in acetone in the presence of redox-innocent metal ions (Sc(OTf)3 and Y(OTf)3) or triflic acid affords a blue species 1, which is converted reversibly to a green species 2 upon cooling to 193 K. The electronic structures of 1 and 2 have been determined by combining advanced spectroscopic techniques (X-band electron paramagnetic resonance (EPR), electron nuclear double resonance (ENDOR), X-ray absorption spectroscopy/extended X-ray absorption fine structure (XAS/EXAFS), and magnetic circular dichroism (MCD)) with ab initio theoretical studies. Complex 1 is best represented as an S = 1/2 [(Sol)(TAML•+)CoIII---OH(LA)]- species (LA = Lewis/Brønsted acid and Sol = solvent), where an S = 1 Co(III) center is antiferromagnetically coupled to S = 1/2 TAML•+, which represents a one-electron oxidized TAML ligand. In contrast, complex 2, also with an S = 1/2 ground state, is found to be multiconfigurational with contributions of both the resonance forms [(H-TAML)CoIV═O(LA)]- and [(H-TAML•+)CoIII═O(LA)]-; H-TAML and H-TAML•+ represent the protonated forms of TAML and TAML•+ ligands, respectively. Thus, the interconversion of 1 and 2 is associated with a LA-associated tautomerization event, whereby H+ shifts from the terminal -OH group to TAML•+ with the concomitant formation of a terminal cobalt-oxo species possessing both singlet (SCo = 0) Co(III) and doublet (SCo = 1/2) Co(IV) characters. The reactivities of 1 and 2 at different temperatures have been investigated in oxygen atom transfer (OAT) and hydrogen atom transfer (HAT) reactions to compare the activation enthalpies and entropies of 1 and 2.

Experimental Study on Dynamic Characteristics of Damaged Post-Tensioning Concrete Sleepers Using Impact Hammer.

Concrete sleepers in operation are commonly damaged by various internal and external factors, such as poor materials, manufacturing defects, poor construction, environmental factors, and repeated loads and driving characteristics of trains; these factors affect the vibration response, mode shape, and natural frequency of damaged concrete sleepers. However, current standards in South Korea require only a subjective visual inspection of concrete sleepers to determine the damage degree and necessity of repair or replacement. In this study, an impact hammer test was performed on concrete sleepers installed on the operating lines of urban railroads to assess the field applicability of the modal test method, with the results indicating that the natural frequency due to concrete sleeper damage was lower than that of the undamaged state. Furthermore, the discrepancy between the simulated and measured natural frequencies of the undamaged concrete sleeper was approximately 1.87%, validating the numerical analysis result. The natural frequency of the damaged concrete sleepers was lower than that of the undamaged concrete sleeper, and cracks in both the concrete sleeper core and the rail seat had the lowest natural frequency among all the damage categories. Therefore, the damage degrees of concrete sleepers can be quantitatively estimated using measured natural-frequency values.

Internet-Based Interventions for Preventing Premature Birth Among Pregnant Women: Systematic Review.

BACKGROUND: Premature birth rates have slightly increased globally, making its prevention critical for both short-term and long-term health outcomes. Various interventions have been developed in response to the multifaceted risk factors for premature birth, including internet-based programs. These programs offer accessibility and enhanced engagement; however, their overall efficacy in preventing premature births requires thorough evaluation. OBJECTIVE: This systematic review aims to identify the study designs and assess the effectiveness of internet-based interventions in preventing premature birth among pregnant women. METHODS: A comprehensive search of the MEDLINE, Embase, CINAHL, and Cochrane Library databases was conducted to identify randomized trials and quasi-experimental studies evaluating internet-based interventions for premature birth prevention in pregnant women. The search was inclusive, with no restrictions based on language or geographical location, allowing for a comprehensive global perspective. The time frame for the inclusion of studies extended until February 2023. The risk of bias (RoB) in each study was independently assessed by 3 authors forming pairs, using the revised Cochrane RoB tool (RoB 2) for randomized trials, as per the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Owing to heterogeneity in populations, measurements, and interventions, a meta-analysis was not conducted. RESULTS: This review included 26 articles, comprising 12 intention-to-treat and 14 per-protocol studies. The overall RoB was high in most intention-to-treat studies and of some concern in most per-protocol studies. The target populations varied, including nonspecific pregnant women, those with gestational diabetes mellitus (GDM) or those at risk of GDM, individuals with anxiety or depression, and those experiencing preterm labor. Psychosocial, physiological, and wellness health outcomes were evaluated. Internet-based interventions effectively reduced stress/distress in nonspecific pregnant women but not in those experiencing preterm labor. Their effectiveness in reducing anxiety and depression varied, with inconsistent results among different groups. In women with GDM or those at risk of GDM, interventions successfully controlled fasting plasma glucose and 2-hour postprandial plasma glucose levels but did not consistently manage glycated hemoglobin levels. These interventions did not reduce the incidence of premature births across the various populations studied. The effectiveness of these internet-based interventions in addressing substance or alcohol abuse and insomnia also varied. CONCLUSIONS: Internet-based interventions show promise in improving psychosocial health and managing blood sugar to prevent premature birth, highlighting variability in effectiveness across different risk factors. Further research, including clinical trials, is vital for developing, evaluating, and disseminating effective, safe internet-based interventions. Establishing standardized measurement tools and rigorous evaluation processes is crucial for enhancing these interventions' effectiveness and reliability in clinical practice, significantly contributing to preventing premature births and improving maternal health outcomes. TRIAL REGISTRATION: PROSPERO CRD42021278847; https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021278847.

Discovery of CRN04894: A Novel Potent Selective MC2R Antagonist.

A novel class of nonpeptide melanocortin type 2 receptor (MC2R) antagonists was discovered through modification of known nonpeptide MC4R ligands. Structure-activity relationship (SAR) studies led to the discovery of 17h (CRN04894), a highly potent and subtype-selective first-in-class MC2R antagonist, which demonstrated remarkable efficacy in a rat model of adrenocorticotrophic hormone (ACTH)-stimulated corticosterone secretion. Oral administration of 17h suppressed ACTH-stimulated corticosterone secretion in a dose-dependent manner at doses ≥3 mg/kg. With its satisfactory pharmaceutical properties, 17h was advanced to Phase 1 human clinical trials in healthy volunteers with the goal of moving into patient trials to evaluate CRN04894 for the treatment of ACTH-dependent diseases, including congenital adrenal hyperplasia (CAH) and Cushing's disease (CD).

Factors associated with clinical nurses' preconception health behavior in Korea: a cross-sectional survey.

PURPOSE: Nurses have been reported to be at an increased risk for miscarriage and preterm labor. However, there is limited knowledge regarding nurses' preconception health behaviors. Therefore, this study aimed to identify factors influencing these behaviors. METHODS: One hundred sixty nurses, who were planning their first pregnancy within the upcoming year, participated in an online survey from August 11 to October 31, 2021. Data on preconception health behavior, perceived health status, pregnancy anxiety, nursing practice environment, and social support were analyzed using the t-test, Pearson correlation coefficients, and multiple regression analysis. RESULTS: Age (р=.024), educational level (р=.010), marital status (р=.003), work experience (р=.003), satisfaction with the work department (р<.001), smoking status (р=. 039), and previous health problems related to pregnancy outcomes (р=.004) were significantly associated with nurses' preconception health behaviors. Furthermore, perceived health status (р<.001), pregnancy anxiety (р=.011), nursing practice environment (р=.003), and social support (р<.001) showed significant correlations with preconception health behaviors. Social support (ß=. 28, р=.001), satisfaction with the work department (ß=.23, р=.032), marital status (ß=.22, р=.002), and perceived health status (ß=.23, р=.002) were confirmed as factors associated with preconception health behaviors. These factors explained 40.9% of the variance in preconception health behaviors (F=6.64, р<.001). CONCLUSION: Clinical nurses' preconception health behaviors were influenced by social support, perceived health status, satisfaction with the work department, and marital status. Interventions to improve clinical nurses' preconception health behaviors should target social support and perceived health status. A preconception health behavior education program considering clinical nurses' marital status and satisfaction with the workplace can also be implemented.

Stress Control in Older People through Healing Garden Activities.

This study, conducted on a group older than 60-years-of-age, sought to verify if healing garden activities control stress in older people. The experimental group performed garden activities once a week for 12 weeks, for 2 h each day, and the control group continued their daily lives. Each group's cumulative stress at the beginning and end, along with total power (TP), the standard deviation of the normal-to-normal interval (SDNN), and the root mean square differences of successive R-R intervals (RMSSD), were measured using u-Bio MACPA, a stress index meter. The analysis showed that the experimental group had a statistically significant decrease in cumulative stress, compared to the control group; and also that TP significantly increased, compared to the control group. The SDNN and RMSSD of the experimental group increased, and decreased in the control group, but the changes were not statistically significant. The fact that cumulative stress decreased and stress evaluation indicators increased shows that daily stress can be controlled through healing garden activities. However, due to the small number of participants in the experiment, its ability to be generalized to all elderly people is subject to a number of limitations. Nevertheless, I think it is meaningful that the finding that garden activities are significant in mediating stress in the elderly was verified using a scientific measurement instrument. Future studies should explore the healing effectiveness of gardens in other age groups.

Characterization of Flexural Behavior of Hybrid Concrete-Filled Fiber-Reinforced Plastic Piles.

The reinforcing fibers in filament winding fiber-reinforced polymer (FFRP) are not arranged in the axial direction; thus, the members are vulnerable to bending and shear stresses. To address the limitations, this study evaluated FRP-concrete composite piles with reinforcing fiber arranged in circumferential directions. In particular, modular pultruded FRP (PFRP) members were fabricated with reinforcing fibers arranged in the axial and circumferential directions. The exterior of the fabricated PFRP members was reinforced with FFRP, and the flexural performance of these members was investigated through flexural strength tests. The results obtained from the flexural tests and flexural-stiffness prediction formula differed by approximately 0.72-1.36 times. A comparison between the results of the flexural test and flexural-strength prediction equation showed an error of approximately 1 to 10%.

Development and validation of a self-management self-efficacy scale for premature birth prevention (SMSE-PBP) for women of childbearing age.

BACKGROUND: This study aimed to develop and evaluate the validity and reliability of a self-management self-efficacy for premature birth prevention (SMSE-PBP) in women of childbearing age (WCA). METHODS: Instrument development and validation were undertaken in three phases: conceptualization, item generation and evaluation of content validity, and evaluation of construct and concurrent validity and reliability. Data were analyzed using exploratory and second-order confirmatory factor analyses, and concurrent validity was examined using Pearson's correlation coefficients. The reliability was analyzed using omega hierarchical and Cronbach's ⍺. RESULTS: Content validity was assessed by experts and cognitive interviews of WCA. The SMSE-PBP consists of a second-order 3-dimension and 10-factor scale with 60 items; therefore, the construct and concurrent validity of the SMSE-PBP were supported. The omega values were 0.93 for pre-pregnancy SMSE-PBP, 0.92 for pregnancy SMSE-PBP, and 0.94 for hospital SMSE-PBP. Cronbach's ⍺ was 0.88 for pre-pregnancy SMSE-PBP, 0.96 for pregnancy SMSE-PBP, and 0.96 for hospital SMSE-PBP. CONCLUSIONS: The SMSE-PBP scale is valid and reliable for WCA; it is helpful for WCA and health professionals to assess women's SMSE-PBP and pre-pregnancy, pregnancy, or hospital SMSE-PBP. The next steps should include assessing the relationship with pregnancy health behaviors.

Evaluation of PDL1 positive cancer cell-specific binding activity of recombinant anti-PDL1 scFv.

Programmed cell death-ligand 1 (PDL1) is a transmembrane protein that is characterized as an immune regulatory molecule. We recently developed a recombinant single-chain fragment of variable domain (scFv) against PDL1, which showed high binding efficiency to purified recombinant PDL1 protein. However, at that time, proof-of-concept data for the effect of scFv using PDL1-expressing cells was lacking. In this study, we conducted two kinds of cell-based immunoassays, western blotting and enzyme-linked immunosorbent assay, using anti-PDL1 scFv. The results indicate that scFv can selectively and sensitively detect PDL1 from PDL1 positive human cancer cell lines. Our findings suggest that scFv could be used as a potential PDL1 inhibitor agent and probe for cell-based immunoassays to detect PDL1.

Iridium-Cooperated, Symmetry-Broken Manganese Oxide Nanocatalyst for Water Oxidation.

The water oxidation reaction, the most important reaction for hydrogen production and other sustainable chemistry, is efficiently catalyzed by the Mn4CaO5 cluster in biological photosystem II. However, synthetic Mn-based heterogeneous electrocatalysts exhibit inferior catalytic activity at neutral pH under mild conditions. Symmetry-broken Mn atoms and their cooperative mechanism through efficient oxidative charge accumulation in biological clusters are important lessons but synthesis strategies for heterogeneous electrocatalysts have not been successfully developed. Here, we report a crystallographically distorted Mn-oxide nanocatalyst, in which Ir atoms break the space group symmetry from I41/amd to P1. Tetrahedral Mn(II) in spinel is partially replaced by Ir, surprisingly resulting in an unprecedented crystal structure. We analyzed the distorted crystal structure of manganese oxide using TEM and investigated how the charge accumulation of Mn atoms is facilitated by the presence of a small amount of Ir.

Genetic Characteristics of Patients with Young-Onset Myelodysplastic Neoplasms.

Myelodysplastic neoplasm (MDS) is a heterogeneous group of myeloid neoplasms affected by germline and somatic genetic alterations. The incidence of MDS increases with age but rarely occurs at a young age. We investigated the germline and somatic genetic alterations of Korean patients with young-onset MDS (<40 years). Among the thirty-one patients, five (16.1%) had causative germline variants predisposing them to myeloid neoplasms (three with GATA2 variants and one each with PGM3 and ETV variants). We found that PGM3 deficiency, a subtype of severe immunodeficiency, predisposes patients to MDS. Somatic mutations were identified in 14 patients (45.2%), with lower rates in patients aged < 20 years (11.1%). Nine (29%) patients had U2AF1 S34F/Y mutations, and patients with U2AF1 mutations showed significantly worse progression-free survival (p < 0.001) and overall survival (p = 0.006) than those without U2AF1 mutations. A UBA1 M41T mutation that causes VEXAS syndrome was identified in a male patient. In conclusion, a germline predisposition to myeloid neoplasms occurred in ~16% of young-onset MDS patients and was largely associated with primary immunodeficiencies, including GATA2 deficiency. Furthermore, the high frequency of somatic U2AF1 mutations in patients with young-onset MDS suggests the presence of a distinct MDS subtype.

[Development of a Reward Scale for Hospital Nurses].

PURPOSE: This study aimed to develop and test a reward scale for hospital nurses. METHODS: The initial items were identified through a literature review and focus group interviews with ten hospital nurses. The content validity of the items was evaluated by ten experts. Fifty-one items were derived from the pilot survey. Four hundred eighty-eight nurses participated in the study: 248 for exploratory factor analysis (EFA) and 240 confirmatory factor analysis (CFA). Data were analyzed using item analysis, EFA, CFA, convergent validity, known-group validity, and internal consistency using IBM SPSS Statistics 29.0 and IBM SPSS AMOS 29.0. RESULTS: The final scale consisted of 31 items and eight factors (decent wage, opportunity to grow and develop, support for special situations, various benefits, flexibility of work, job-related achievement, reflecting career and performance, and recognition), which explained 67.3% of the total variance. The eight-subscale model was validated by CFA. Convergent validity was evaluated by analyzing correlation with intention to leave (r = -.63, p < .001) and job satisfaction (r = .54, p < .001). The known-group validity was evaluated by comparing the reward scales according to age, clinical career, income level and hospital type. The scale was found to be reliable with a Cronbach's α of .89. CONCLUSION: Both the validity and reliability of the reward scale for hospital nurses are verified, which can enhance the understanding of the range of rewards and may assist nurse managers in establishing an effective reward system.

Re-Emergence of HMPV in Gwangju, South Korea, after the COVID-19 Pandemic.

The non-pharmaceutical interventions implemented to prevent the spread of COVID-19 have affected the epidemiology of other respiratory viruses. In South Korea, Human metapneumovirus (HMPV) typically occurs from winter to the following spring; however, it was not detected for two years during the COVID-19 pandemic and re-emerged in the fall of 2022, which is a non-epidemic season. To examine the molecular genetic characteristics of HMPV before and after the COVID-19 pandemic, we analyzed 427 HMPV-positive samples collected in the Gwangju area from 2018 to 2022. Among these, 24 samples were subjected to whole-genome sequencing. Compared to the period before the COVID-19 pandemic, the incidence rate of HMPV in 2022 increased by 2.5-fold. Especially in the age group of 6-10 years, the incidence rate increased by more than 4.5-fold. In the phylogenetic analysis results, before the COVID-19 pandemic, the A2.2.2 lineage was predominant, while in 2022, the A2.2.1 and B2 lineage were observed. The non-pharmaceutical interventions implemented after COVID-19, such as social distancing, have reduced opportunities for exposure to HMPV, subsequently leading to decreased acquisition of immunity. As a result, HMPV occurred during non-epidemic seasons, influencing the age distribution of its occurrences.

Evaluation of Flexural Toughness of Concrete Reinforced with High-Performance Steel Fiber.

In this study, a flexural test and residual stress evaluation using the aspect ratio (65 and 80) and steel fiber content (20, 30, and 40 kg/m3) as variables were conducted according to the EN 14651 standard to investigate the flexural toughness of concrete reinforced with high-performance arched steel fibers. The result of the flexural test show that the residual stress was 114.5% higher in the test specimen with high curvature and high content of arched steel fibers than that in the other conditions. In addition, the energy absorption capacity of arched steel fiber-reinforced concrete increased by 138.88% compared to concrete.

Inhibition of Microsomal Prostaglandin E2 Synthase Reduces Collagen Deposition in Melanoma Tumors and May Improve Immunotherapy Efficacy by Reducing T-cell Exhaustion.

The arachidonic acid pathway participates in immunosuppression in various types of cancer. Our previous observation detailed that microsomal prostaglandin E2 synthase 1 (mPGES-1), an enzyme downstream of cyclooxygenase 2 (COX-2), limited antitumor immunity in melanoma; in addition, genetic depletion of mPGES-1 specifically enhanced immune checkpoint blockade therapy. The current study set out to distinguish the roles of mPGES-1 from those of COX-2 in tumor immunity and determine the potential of mPGES-1 inhibitors for reinforcing immunotherapy in melanoma. Genetic deletion of mPGES-1 showed different profiles of prostaglandin metabolites from that of COX-2 deletion. In our syngeneic mouse model, mPGES-1-deficient cells exhibited similar tumorigenicity to that of COX-2-deficient cells, despite a lower ability to suppress PGE2 synthesis by mPGES-1 depletion, indicating the presence of factors other than PGE2 that are likely to regulate tumor immunity. RNA-sequencing analysis revealed that mPGES-1 depletion reduced the expressions of collagen-related genes, which have been found to be associated with immunosuppressive signatures. In our mouse model, collagen was reduced in mPGES-1-deficient tumors, and phenotypic analysis of tumor-infiltrating lymphocytes indicated that mPGES-1-deficient tumors had fewer TIM3+ exhausted CD8+ T cells compared with COX-2-deficient tumors. CAY10678, an mPGES-1 inhibitor, was equivalent to celecoxib, a selective COX-2 inhibitor, in reinforcing anti-PD-1 treatment. Our study indicates that mPGES-1 inhibitors represent a promising adjuvant for immunotherapies in melanoma by reducing collagen deposition and T-cell exhaustion. Significance: Collagen is a predominant component of the extracellular matrix that may influence the tumor immune microenvironment for cancer progression. We present here that mPGES-1 has specific roles in regulating tumor immunity, associated with several collagen-related genes and propose that pharmacologic inhibition of mPGES-1 may hold therapeutic promise for improving immune checkpoint-based therapies.

Structural Integrity Assessment of Concrete Sleepers by Modal Test Technique.

Concrete sleepers used in railway engineering are subject to damage, such as cracks and breakage. Damaged concrete sleepers undergo changes to their material and structural properties, including response, mode shape, and natural frequency. Therefore, we have proposed modal testing in this study to quantitatively evaluate the structural integrity of concrete sleepers. The results of modal testing were compared with those of numerical analysis and visual inspection. In addition, an impact hammer test was conducted to evaluate the structural performance of damaged concrete sleepers. The results show that natural-frequency analysis using the modal-testing technique can usefully complement visual inspection for structural performance evaluation in the field.

Actionability classification of variants of unknown significance correlates with functional effect.

Genomically-informed therapy requires consideration of the functional impact of genomic alterations on protein expression and/or function. However, a substantial number of variants are of unknown significance (VUS). The MD Anderson Precision Oncology Decision Support (PODS) team developed an actionability classification scheme that categorizes VUS as either "Unknown" or "Potentially" actionable based on their location within functional domains and/or proximity to known oncogenic variants. We then compared PODS VUS actionability classification with results from a functional genomics platform consisting of mutant generation and cell viability assays. 106 (24%) of 438 VUS in 20 actionable genes were classified as oncogenic in functional assays. Variants categorized by PODS as Potentially actionable (N = 204) were more likely to be oncogenic than those categorized as Unknown (N = 230) (37% vs 13%, p = 4.08e-09). Our results demonstrate that rule-based actionability classification of VUS can identify patients more likely to have actionable variants for consideration with genomically-matched therapy.

Unlocking Cu(I)-Mediated Catalytic Pathways for Efficient ROS Generation by Incorporating an Oxazole-Based Histidine Surrogate into Cu(II)-ATCUN Complexes.

The catalytic redox activity of Cu(II) bound to the amino-terminal copper and nickel (ATCUN) binding motif (Xxx-Zzz-His, XZH) is stimulating the development of catalytic metallodrugs based on reactive oxygen species (ROS)-mediated biomolecule oxidation. However, low Cu(I) availability resulting from the strong Cu(II) binding affinity of the ATCUN motif is regarded as a limitation to efficient ROS generation. To address this, we replaced the imidazole moiety (pKa 7.0) of Gly-Gly-His-NH2 (GGHa, a canonical ATCUN peptide) with thiazole (pKa 2.7) and oxazole (pKa 0.8), yielding GGThia and GGOxa, respectively. A newly synthesized amino acid, Fmoc-3-(4-oxazolyl)-l-alanine, served as a histidine surrogate featuring an azole ring with the lowest pKa among known analogues. Despite similar square-planar Cu(II)-N4 geometries being observed for the three Cu(II)-ATCUN complexes by electron paramagnetic resonance spectroscopy and X-ray crystallography, the azole modification enabled the Cu(II)-ATCUN complexes to exhibit significant rate enhancement for ROS-mediated DNA cleavage. Further analyses based on Cu(I)/Cu(II) binding affinities, electrochemical measurements, density functional theory calculations, and X-ray absorption spectroscopy indicated that the azole modification enhanced the accessibility of the Cu(I) oxidation state during ROS generation. Our oxazole/thiazole-containing ATCUN motifs provide a new design strategy for peptide ligands with modulated N donor ability, with potential applications in the development of ROS-mediated metallodrugs.

Determination of Mechanical Properties of Sand-Coated Carbon Fiber Reinforced Polymer (CFRP) Rebar.

This experimental study investigates the fundamental mechanical characteristics of the carbon fiber-reinforced polymer (CFRP) bars, including the tensile strength, compressive strength, shear strength, and modulus of elasticity of the CFRP bar. The properties need to be accurately determined to understand the behavior of the concrete structures reinforced with CFRP rebars. The CFRP rebar was coated with sand to enhance the adhesive strength of the concrete. Three diameters of CFRP rebar (D10, D12, and D16) were considered in accordance with ASTM provisions. A coefficient, i.e., the ratio of shear strength to tensile strength, was employed to predict the tensile strength of the CFRP rebar specimens. The test results confirm that the tensile strength of CFRP rebar is dependent on its diameter due to the shear lag effect. A coefficient in the range of 0.17 to 0.2 can be used to predict the tensile strength of CFRP rebar using shear strength.