Complement C3-Deficiency-Induced Constipation in FVB/N-C3em1Hlee/Korl Knockout Mice Was Significantly Relieved by Uridine and Liriope platyphylla L. Extracts.

Complement component 3 (C3) deficiency has recently been known as a cause of constipation, without studies on the therapeutic efficacy. To evaluate the therapeutic agents against C3-deficiency-induced constipation, improvements in the constipation-related parameters and the associated molecular mechanisms were examined in FVB/N-C3em1Hlee/Korl knockout (C3 KO) mice treated with uridine (Urd) and the aqueous extract of Liriope platyphylla L. (AEtLP) with laxative activity. The stool parameters and gastrointestinal (GI) transit were increased in Urd- and AEtLP-treated C3 KO mice compared with the vehicle (Veh)-treated C3 KO mice. Urd and AEtLP treatment improved the histological structure, junctional complexes of the intestinal epithelial barrier (IEB), mucin secretion ability, and water retention capacity. Also, an improvement in the composition of neuronal cells, the regulation of excitatory function mediated via the 5-hydroxytryptamine (5-HT) receptors and muscarinic acetylcholine receptors (mAChRs), and the regulation of the inhibitory function mediated via the neuronal nitric oxide synthase (nNOS) and inducible NOS (iNOS) were detected in the enteric nervous system (ENS) of Urd- and AEtLP-treated C3 KO mice. Therefore, the results of the present study suggest that C3-deficiency-induced constipation can improve with treatment with Urd and AEtLP via the regulation of the mucin secretion ability, water retention capacity, and ENS function.

Confining the Sol-Gel Reaction at the Water/Oil Interface: Creating Compartmentalized Enzymatic Nano-Organelles for Artificial Cells.

Living organisms compartmentalize their catalytic reactions in membranes for increased efficiency and selectivity. To mimic the organelles of eukaryotic cells, we develop a mild approach for in situ encapsulating enzymes in aqueous-core silica nanocapsules. In order to confine the sol-gel reaction at the water/oil interface of miniemulsion, we introduce an aminosilane to the silica precursors, which serves as both catalyst and an amphiphilic anchor that electrostatically assembles with negatively charged hydrolyzed alkoxysilanes at the interface. The semi-permeable shell protects enzymes from proteolytic attack, and allows the transport of reactants and products. The enzyme-carrying nanocapsules, as synthetic nano-organelles, are able to perform cascade reactions when enveloped in a polymer vesicle, mimicking the hierarchically compartmentalized reactions in eukaryotic cells. This in situ encapsulation approach provides a versatile platform for the delivery of biomacromolecules.

Does repair of deltoid ligament contribute to restoring a mortise in SER type IV ankle fracture with syndesmotic diastasis?

PURPOSE: To analyze the radiographic and clinical outcomes of deltoid ligament repair, we studied 34 supination external rotation type IV ankle fracture patients with deltoid ruptures who required syndesmosis fixation. METHODS: We retrospectively evaluated 34 cases of ruptured deltoid ligaments with associated supination external rotation type IV ankle fractures with a widening of the syndesmosis between 2011 and 2017. All of the ankle fractures were treated with a similar surgical protocol (plate and screw fixation). Syndesmotic fixations were performed on all patients. The deltoid ligaments were surgically repaired in 19 patients and in 15 patients, they were not. The preoperative, immediate postoperative, and final follow-up radiographic outcomes (medial clear space, overlap space, and clear space) and clinical scores (Foot and Ankle Outcome Scores and the Foot Function Index) were compared. Patients were followed for an average of 13.6 months. RESULTS: There was no significant difference in radiographic and clinical outcomes between the deltoid repair group and the unrepair group (P > 0.05). In both groups, the mean immediate postoperative radiographic outcomes were satisfactory, showing reduced MCS, reduced CS, and increased OS to within-normal ranges that were maintained at the final follow-up. Clinical outcomes were similar between the two groups (P > 0.05). The rate of complications, such as intra-articular lesions, malunions, nonunions, and arthrosis was comparable between the two groups. CONCLUSION: In both groups, the postoperative and final follow-up radiographic measures were within normal ranges and the radiographic and clinical outcomes were not significantly different between the two groups. Syndesmotic reduction could be much more important than deltoid repair in regard to mortise restoration and medial stability.

Comparison of Helical Blade Systems for Osteoporotic Intertrochanteric Fractures Using Biomechanical Analysis and Clinical Assessments.

Background and Objectives: This study aimed to compare the biomechanical properties and outcomes of osteoporotic intertrochanteric fractures treated with two different helical blade systems, the trochanteric fixation nail-advanced (TFNA) and proximal femoral nail antirotation II (PFNA), to evaluate the efficacy and safety of the newly introduced TFNA system. Materials and Methods: A biomechanical comparison of the two helical blades was performed using uniaxial compression tests on polyurethane foam blocks of different densities. The peak resistance (PR) and accumulated resistance (AR) were measured during the 20 mm advancement through the test block. For clinical comparison, 63 osteoporotic intertrochanteric fractures treated with TFNA were identified and compared with the same number of fractures treated with PFNA using propensity score matching. Ambulatory status, medial migration, lateral sliding, fixation failure, and patient-reported outcomes were compared between the two groups over a minimum of 1 year's follow up. Results: The uniaxial compression test showed that a slightly, but significantly lower resistance was required to advance the TFNA through the test block compared with the PFNA (20 PCF, p = 0.017 and p = 0.026; 30 PCF, p = 0.007 and p = 0.001 for PR and AR, respectively). Clinically, the two groups showed no significant differences in post-operative ambulatory status and patient-reported outcomes. However, in TFNA groups, significantly more medial migration (TFNA, 0.75 mm; PFNA, 0.40 mm; p = 0.0028) and also, lateral sliding was noted (TFNA, 3.99 mm; PFNA, 1.80 mm; p = 0.004). Surgical failure occurred in four and two fractures treated with the TFNA and PFNA, respectively. Conclusions: The results of our study suggest that the newly introduced TFNA provides clinical outcomes comparable with those of the PFNA. However, inferior resistance to medial migration in the TFNA raises concerns regarding potential fixation failures.

Oncolytic Nanoreactors Producing Hydrogen Peroxide for Oxidative Cancer Therapy.

In situ generation of anticancer agents at the place of the disease is a new paradigm for cancer therapy. The production of highly potent drugs by nanoreactors through a facile synthesis pathway is demanded. We report an oncolytic nanoreactor platform loaded with the enzyme glucose oxidase (GOX) to produce hydrogen peroxide. For the first time, we realized a core-shell structure with encapsulated GOX under mild synthetic conditions, which ensured high remaining activity of GOX inside of the nanoreactor. Moreover, the nanoreactor protected the loaded GOX from proteolysis and contributed to increased thermal stability of the enzyme. The nanoreactors were effectively taken up into different cancer cells, in which they produced hydrogen peroxide by consuming intracellular glucose and oxygen, thereby leading to effective death of the cancer cells. In summary, our robust nanoreactors are a promising platform for effective anticancer therapy and sustained enzyme utilization.

Enzyme-Loaded Nanoreactors Enable the Continuous Regeneration of Nicotinamide Adenine Dinucleotide in Artificial Metabolisms.

Nicotinamide adenine dinucleotide (NAD) is an essential coenzyme for numerous biocatalytic pathways. While in nature, NAD+ is continuously regenerated from NADH by enzymes, all synthetic NAD+ regeneration strategies require a continuous supply of expensive reagents and generate byproducts, making these strategies unattractive. In contrast, we present an artificial enzyme combination that produces NAD+ from oxygen and water continuously; no additional organic substrates are required once a minimal amount pyruvate is supplied. Three enzymes, i.e., LDH, LOX, and CAT, are covalently encapsulated into a substrate-permeable silica nanoreactor by a mild fluoride-catalyzed sol-gel process. The enzymes retain their activity inside of the nanoreactors and are protected against proteolysis and heat. We successfully used NAD+ from the nanoreactors for the continuous production of NAD+ i) to sense glucose in artificial glucose metabolism, and ii) to reduce the non-oxygen binding methemoglobin to oxygen-binding hemoglobin. This latter conversion might be used for the treatment of Methemoglobinemia. We believe that this versatile tool will allow the design of artificial NAD+ -dependent metabolisms or NAD+ -mediated redox-reactions.

COVID-19 Outbreak and Its Association with Healthcare Workers' Emotional Stress: a Cross-Sectional Study.

BACKGROUND: The coronavirus disease 2019 (COVID-19) outbreak has exposed healthcare workers to extreme physical workloads and psychological challenges. Thus, we aimed to assess the immediate correlates of emotional stress and to identify which specific jobs, departments, and exposure types are risk factors for emotional stress in healthcare workers. METHODS: In this cross-sectional study conducted from April 2 to 10, 2020, university hospital workers were administered self-reported questionnaires that covered general characteristics and included the Patient Health Questionnaire, Generalized Anxiety Disorder scale, and a visual analog scale. At-risk groups for depression and anxiety were identified, and the odds ratios for depression and anxiety were analyzed after adjusting for age, gender, education, marital status, and duration of employment. RESULTS: The data of 1,003 participants were analyzed. Of these, 14.2% worked in wards for confirmed COVID-19 cases and 15.2% had had direct contact with these patients. Treating patients with COVID-19 was associated with depression and anxiety, while dealing with COVID-19 test samples was associated with depression. Exposure to random or unspecified patients was also associated with depression. Lastly, social rejection and other negative experiences were associated with depression and anxiety. CONCLUSION: The COVID-19 outbreak is correlated with healthcare workers' emotional stress, and specific types of jobs and duties involving close contact with these patients can be risk factors. Interestingly, even low-exposure groups reported significant depression and anxiety as a result of social stigma and uncertainty. Adequate and timely management measures for emotional stress are required for vulnerable and at-risk groups.

Polymer-Based Module for NAD+ Regeneration with Visible Light.

The regeneration of enzymatic cofactors by cell-free synthetic modules is a key step towards producing a purely synthetic cell. Herein, we demonstrate the regeneration of the enzyme cofactor NAD+ by photo-oxidation of NADH under visible-light irradiation by using metal-free conjugated polymer nanoparticles. Encapsulation of the light-active nanoparticles in the lumen of polymeric vesicles produced a fully organic module able to regenerate NAD+ in an enzyme-free system. The polymer compartment conferred physical and chemical autonomy to the module, allowing the regeneration of NAD+ to occur efficiently, even in harsh chemical environments. Moreover, we show that regeneration of NAD+ by the photocatalyst nanoparticles can oxidize a model substrate, in conjunction with the enzyme glycerol dehydrogenase. To ensure the longevity of the enzyme, we immobilized it within a protective silica matrix; this yielded enzymatic silica nanoparticles with enhanced long-term performance and compatibility with the NAD+ -regeneration system.

Efficient capture and simple quantification of circulating tumor cells using quantum dots and magnetic beads.

Circulating tumor cells (CTCs) are valuable biomarkers for monitoring the status of cancer patients and drug efficacy. However, the number of CTCs in the blood is extremely low, and the isolation and detection of CTCs with high efficiency and sensitivity remain a challenge. Here, we present an approach to the efficient capturing and simple quantification of CTCs using quantum dots and magnetic beads. Anti-EpCAM antibody-conjugated quantum dots are used for the targeting and quantification of CTCs, and quantum-dot-attached CTCs are isolated using anti-IgG-modified magnetic beads. Our approach is shown to result in a capture efficiency of about 70%-80%, enabling the simple quantification of captured CTCs based on the fluorescence intensity of the quantum dots. The present method can be used effectively in the capturing and simple quantification of CTCs with high efficiency for cancer diagnosis and monitoring.

Nanotentacle-structured magnetic particles for efficient capture of circulating tumor cells.

Circulating tumor cells (CTCs) have attracted considerable attention as promising markers for diagnosing and monitoring the cancer status. Despite many technological advances in isolating CTCs, the capture efficiency and purity still remain challenges that limit clinical practice. Here, the construction of "nanotentacle"-structured magnetic particles using M13-bacteriophage and their application for the efficient capturing of CTCs is demonstrated. The M13-bacteriophage to magnetic particles followed by modification with PEG is conjugated, and further tethered monoclonal antibodies against the epidermal receptor 2 (HER2). The use of nanotentacle-structured magnetic particles results in a high capture purity (>45%) and efficiency (>90%), even for a smaller number of cancer cells (≈25 cells) in whole blood. Furthermore, the cancer cells captured are shown to maintain a viability of greater than 84%. The approach can be effectively used for capturing CTCs with high efficiency and purity for the diagnosis and monitoring of cancer status.

Size-controlled construction of magnetic nanoparticle clusters using DNA-binding zinc finger protein.

Nanoparticle clusters (NPCs) have attracted significant interest owing to their unique characteristics arising from their collective individual properties. Nonetheless, the construction of NPCs in a structurally well-defined and size-controllable manner remains a challenge. Here we demonstrate a strategy to construct size-controlled NPCs using the DNA-binding zinc finger (ZnF) protein. Biotinylated ZnF was conjugated to DNA templates with different lengths, followed by incubation with neutravidin-conjugated nanoparticles. The sequence specificity of ZnF and programmable DNA templates enabled a size-controlled construction of NPCs, resulting in a homogeneous size distribution. We demonstrated the utility of magnetic NPCs by showing a three-fold increase in the spin-spin relaxivity in MRI compared with Feridex. Furthermore, folate-conjugated magnetic NPCs exhibited a specific targeting ability for HeLa cells. The present approach can be applicable to other nanoparticles, finding wide applications in many areas such as disease diagnosis, imaging, and delivery of drugs and genes.

Antiadhesive Hyaluronic Acid-Based Wound Dressings Promote Wound Healing by Preventing Re-Injury: An In Vivo Investigation.

Wound dressings are widely used to protect wounds and promote healing. The water absorption and antifriction properties of dressings are important for regulating the moisture balance and reducing secondary damages during dressing changes. Herein, we developed a hyaluronic acid (HA)-based foam dressing prepared via the lyophilization of photocrosslinked HA hydrogels with high water absorption and antiadhesion properties. To fabricate the HA-based foam dressing (HA foam), the hydroxyl groups of the HA were modified with methacrylate groups, enabling rapid photocuring. The resulting photocured HA solution was freeze-dried to form a porous structure, enhancing its exudate absorption capacity. Compared with conventional biopolymer-based foam dressings, this HA foam exhibited superior water absorption and antifriction properties. To assess the wound-healing potential of HA foam, animal experiments involving SD rats were conducted. Full-thickness defects measuring 2 × 2 cm2 were created on the skin of 36 rats, divided into four groups with 9 individuals each. The groups were treated with gauze, HA foam, CollaDerm®, and CollaHeal® Plus, respectively. The rats were closely monitored for a period of 24 days. In vivo testing demonstrated that the HA foam facilitated wound healing without causing inflammatory reactions and minimized secondary damages during dressing changes. This research presents a promising biocompatible foam wound dressing based on modified HA, which offers enhanced wound-healing capabilities and improved patient comfort and addresses the challenges associated with conventional dressings.

Incidence and pattern of concurrent capitellum fracture associated with radial head and neck fractures.

BACKGROUND: Radial head and neck fracture is a common fracture around the elbow. It is mostly caused by axial or valgus loading after a fall in elbow extension and forearm pronation. When a radial head and neck fracture occurs, the capitellum collides with the radial head and experiences a shear force, leading to capitellum fracture. The primary aim of this study was to evaluate the incidence of concurrent capitellum fracture and analyze its patterns among patients treated for radial head and neck fractures based on computed tomography. Secondary aim is to determine factors associated with concurrent capitellum fractures. HYPOTHESIS: Capitellum fractures are more common than expected in radial head and neck fractures and show a consistent pattern. With the higher the Mason type fracture, the higher the incidence of concurrent capitellum fracture will be shown. METHODS: A total of 101 patients treated surgically (27 patients) or non-surgically (74 patients) for radial head and neck fractures from January 2017 to December 2020 were retrospectively analyzed. Initial computed tomography was reviewed to identify concurrent capitellum fractures. A fracture was diagnosed when the bone continuity was lost in two consecutive images in any one of the three directions of computed tomography scan images. Seventeen patients with capitellum fractures were classified as group 1 and 84 patients without capitellum fractures as group 2. Each group of patients was assessed using Mason classification, whether fracture extended to the radial neck or not, fracture location, and treatment method. To determine the fracture location, radial head was trisected using three anatomical landmarks: safe zone, posteromedial zone, and anteromedial zone. And it was determined as the location where the fracture was most comminuted. RESULTS: The average age of the 101 patients was 44.6 years old. There were 54 (53.5%) males and 47 (46.5%) females. Capitellum fracture was accompanied in 17 cases. Its incidence was 16.8%. The rate of accompanying capitellum fracture was 9.5% (6/63) for Mason type 1, 25.0% (6/24) for Mason type 2, and 41.7% (5/12) for Mason type 3. The ratio of radial neck extension of fracture was significantly higher in group 2. There was no isolated radial neck fracture in group 1. However, there were 33 in group 2. After eliminating isolated radial neck fracture patients, significantly more fractures were located in the safety zone in group 1. Group 1 had a significantly higher rate of surgical treatment than group 2 (52.9% (9/17) vs. 21.4% (18/84) p=0.007). CONCLUSION: For radial head and neck fractures, the higher the Mason type fracture, the higher the incidence of concurrent capitellum fracture. When the fracture extended to the radial neck, the comorbidity of the capitellum fracture was decreased. Among radial head fractures, when the fracture was located in the safe zone, the comorbidity of capitellum fracture was increased. The rate of surgical treatment was higher in radial head and neck fracture patients with concurrent capitellum fractures. LEVEL OF EVIDENCE: IV; diagnostic study.

An outbreak of neurologic symptoms among patients exposed to an unknown stench in a high school near an industrial complex: an epidemiological investigation.

OBJECTIVES: Seven students at a high school in Korea visited the emergency room with non-specific neurological symptoms after a stench was noticed during a school entrance ceremony. In relation to this incident, 105 patients visited medical institutions over 5 days. A team of environmental and epidemiological experts was assembled to investigate the incident. METHODS: Our team of experts participated in the investigation 1 month post-incident. Previously, only air samples had been analyzed. We received results of air samples analyzed by other investigators, medical records of some students, and data from police interviews of patients. Additional investigation and interviews were conducted, and the events were reconstructed in spatial and temporal order. RESULTS: A cluster of patients was observed on the south side and parts of the north side of the upper floor. A stench like that reported during the incident had been noticed for about 2 years near the school. Students consistently described a similar stench occurring frequently in the vicinity of the school. According to student statements, the odor mainly resembled something burning. The carboxyhemoglobin levels of some students were observed to be >1.5%. CONCLUSIONS: In the investigation, 2 suspected sources were identified: a science room storing chemicals downstairs from the auditorium and various industrial facilities near the school. Combining the scattered evidence, we considered a toxic puff of gas, perhaps from brief incineration or leakage in a specific area, to be the likely cause of the incident. We describe our approach and the limitations encountered during the investigation.

Association between exposure to particulate matter and school absences in Korean asthmatic adolescents.

Background: Because particulate matter (PM) and asthma are closely related, the prevalence of school absence among adolescents with asthma can be affected by the concentration of PM. We aimed to investigate the relationship between school absences due to asthma and the total number of days that the PM concentration exceeded the standard. Methods: We used the data from the 16th Korea Youth Risk Behavior Survey and the PM levels of 17 metropolitan cities and provinces gathered from the AirKorea. Information on the characteristics of asthmatic adolescents and the prevalence of school absence was obtained using a questionnaire, while the PM levels based on the total number of days with poor and very poor PM grades were collected from the AirKorea website. Both χ2 test and logistic regression analysis were performed using the weights presented in the original dataset. Results: In the case of particulate matter of 10 microns in diameter or smaller (PM10), the odds ratio (OR) after adjusting for confounders (sex, school year, body mass index, smoking history, diagnosis of allergic rhinitis, diagnosis of atopic dermatitis and city size) was 1.07 (95% confidence interval [CI]: 1.01-1.13) for absents due to asthma when the total days of poor and very poor grades of PM10 (81 µg/m3 or higher) increased by 1 day. In the analysis of particulate matter of 2.5 microns in diameter or smaller (PM2.5), the OR after adjusting for confounders was 1.01 (95% CI: 1.00-1.03) for absents due to asthma when the total number of days with poor and very poor PM2.5 grades (36 µg/m3 or higher) increased by 1 day. Conclusions: A significant association was observed between the total number of days of poor and very poor PM10 and PM2.5 grades and school absence due to asthma; PM can cause asthma exacerbation and affect the academic life.

Analysis of Infection Transmission Routes through Exhaled Breath and Cough Particle Dispersion in a General Hospital.

Identifying infection transmission routes in hospitals may prevent the spread of respiratory viruses and mass infections. Most previous related research focused on the air movement of passive tracers, which typically represent breathing. In this study, particle evaporation and dispersions with various particle sizes were applied to evaluate particle movement because of breathing and coughing using computational fluid dynamics (CFD) simulations. Pyeongtaek St. Mary Hospital, where a Middle East respiratory syndrome (MERS) index patient infected several patients on the same floor, was used for a case study. We compared the dispersion characteristics of various particle sizes and validated results by comparing infection rates in different ward. Results indicated that droplets spread across the corridor and dispersed to wards that were more than 17 m apart from the index patient by natural ventilation. Droplets from exhaled breath under steady-state simulation showed a wider range of dispersion than cough droplets under transient simulation, but cough droplet dispersion was more consistent with the actual infection rate in each ward. Cough droplets sized under 75 µm evaporated to 26% of the initial size and started to disperse into the corridor within one minute; in nine minutes, droplets dispersed throughout every ward. This study may increase awareness on the dispersion characteristics of infectious particles.

Multimodal Enzyme-Carrying Suprastructures for Rapid and Sensitive Biocatalytic Cascade Reactions.

Colloidal assemblies of mesoporous suprastructures provide effective catalysis in an advantageous volume-confined environment. However, typical fabrication methods of colloidal suprastructures are carried out under toxic or harmful conditions for unstable biomolecules, such as, biocatalytic enzymes. For this reason, biocatalytic enzymes have rarely been used with suprastructures, even though biocatalytic cascade reactions in confined environments are more efficient than in open conditions. Here, multimodal enzyme- and photocatalyst-carrying superstructures with efficient cascade reactions for colorimetric glucose detection are demonstrated. The suprastructures consisting of various functional nanoparticles, including enzyme-carrying nanoparticles, are fabricated by surface-templated evaporation driven suprastructure synthesis on polydimethylsiloxane-grafted surfaces at ambient conditions. For the fabrication of suprastructures, no additional chemicals and reactions are required, which allows maintaining the enzyme activities. The multimodal enzymes (glucose oxidase and peroxidase)-carrying suprastructures exhibit rapid and highly sensitive glucose detection via two enzyme cascade reactions in confined geometry. Moreover, the combination of enzymatic and photocatalytic cascade reactions of glucose oxidase to titanium dioxide nanoparticles is successfully realized for the same assay. These results show promising abilities of multiple colloidal mixtures carrying suprastructures for effective enzymatic reactions and open a new door for advanced biological reactions and enzyme-related works.

Olfactory Stimulation with Volatile Aroma Compounds of Basil (Ocimum basilicum L.) Essential Oil and Linalool Ameliorates White Fat Accumulation and Dyslipidemia in Chronically Stressed Rats.

We explored the physiological effects of inhaling basil essential oil (BEO) and/or linalool and identified odor-active aroma compounds in BEO using gas chromatography/mass spectrometry (GC-MS) and GC-olfactometry (GC-O). Linalool was identified as the major volatile compound in BEO. Three groups of rats were administered BEO and linalool via inhalation, while rats in the control group were not. Inhalation of BEO for 20 min only reduced the total weight gain (190.67 ± 2.52 g) and increased the forced swimming time (47.33 ± 14.84 s) compared with the control group (219.67 ± 2.08 g, 8.33 ± 5.13 s). Inhalation of BEO for 5 min (392 ± 21 beats/min) only reduced the pulse compared with the control group (420 ± 19 beats/min). Inhalation of linalool only reduced the weight of white adipose tissue (5.75 ± 0.61 g). The levels of stress-related hormones were not significantly different among the groups. The total cholesterol and triglyceride levels decreased after inhalation of BEO for 20 min (by more than -10% and -15%, respectively). Low-density lipoprotein cholesterol levels were lowered (by more than -10%) by the inhalation of BEO and linalool, regardless of the inhalation time. In particular, BEO inhalation for 20 min was associated with the lowest level of low-density lipoprotein cholesterol (53.94 ± 2.72 mg/dL). High-density lipoprotein cholesterol levels increased after inhalation of BEO (by more than +15%). The atherogenic index and cardiac risk factors were suppressed by BEO inhalation. Animals exposed to BEO and linalool had no significant differences in hepatotoxicity. These data suggest that the inhalation of BEO and linalool may ameliorate cardiovascular and lipid dysfunctions. These effects should be explored further for clinical applications.

Performance estimation of lead-free dual-layered shielding in dismantling of steam generator: A Monte-Carlo simulation study.

The Kori-1 nuclear power plant has been permanently shut down since 2017, and its major structures, systems, and components are currently planned to be dismantled according to the final decommissioning plan. To protect dismantling workers from external radiation exposure dose during decommissioning, we propose a dose reduction method involving dual-layered Pb-free shielding. Based on the Monte Carlo method, the performance of the abovementioned method and various types of materials are optimized and estimated in terms of the equivalent dose rate and radiation shielding rate. The results showed that Pb-free shielding with dual layers exhibited better performance than the conventional shield. In addition, the Pb-free material of WC-Co showed a relatively high performance for the reduction of the external radiation exposure dose in the dismantling process of the steam generator (S/G). In the dismantling process of the S/G, the results of our simulation will offer the choice of materials and flexibility in the design of Pb-free shielding with dual layers.

Adverse Effects on Work and Daily Life Interference among Healthcare Workers after the First and Second ChAdOx1 and BNT162b2 COVID-19 Vaccine Doses.

In this study, we assessed the adverse effects and the work and daily life interference associated with each dose of the ChAdOx1 and BNT162b2 COVID-19 vaccines. Questionnaires were distributed to workers after they received both doses; only those who worked the day after receiving the vaccine were included in the analysis. Overall, 368 ChAdOx1-vaccinated and 27 BNT162b2-vaccinated participants were included. Among the ChAdOx1-vaccinated participants, the incidence of adverse effects was significantly lower after the second dose than after the first dose. Among the BNT162b2-vaccinated participants, however, no differences in adverse effects or work and daily life interference were found between the doses. After the first and second dose, the numeric scale score (0-10) for interference with work was 3.9 ± 2.9 and 1.6 ± 1.9 for the ChAdOx1 and 3.2 ± 2.5 and 3.6 ± 3.0 for the BNT162b2 vaccine, respectively. A similar trend was observed for interference with daily life. Factors associated with work and daily life interference in the multivariate model were age, vaccine dose (first or second), and the interaction term of vaccine type and dose. These results could be used to inform the general population of the adverse effects associated with these vaccinations.