Health and job-related factors associated with work ability in older working populations of Korea.

BACKGROUND: Knowledge about determinants of workability is crucial for designing interventions to increase the participation of older employees in the workforce and maintain or increase their productivity levels at work. AIMS: This study explored the impact of health conditions and job characteristics on poor work ability. METHODS: This study used data from the Korean Longitudinal Study of Aging (KLoSA) from 2014 to 2020, which is a nationally representative population-based panel study of Korean citizens aged ≥45 years. The KLoSA survey assessed subjective work ability using work ability score. The participants were asked if they had been diagnosed with any underlying diseases by a physician. The job characteristics were assessed in terms of working conditions and satisfaction. Generalized estimating equations were used to calculate the odds ratios (ORs) and 95% confidence intervals for workers' health-related variables and job characteristics associated with poor work ability. RESULTS: The results showed that workers' health-related factors were associated with poor work ability; poor vision (OR = 1.52) and bad hearing ability (OR = 2.37); low gripping strength (OR = 2.29); poor self-rated health (OR = 3.77) and various diseases such as hypertension, diabetes, cancer, chronic lung disease, liver disease, heart disease, cerebrovascular disease, mental illness, arthritis, prostate disease, gastrointestinal disease and disc disease. Additionally, high physical work demands (OR = 1.51) and low job satisfaction (OR = 4.23) were highly correlated with poor work ability. CONCLUSIONS: The findings addressing poor work abilities caused by individuals' health- and job-related factors can help prioritize worker health management and the development of more effective human capital investment strategies at the workplace.

Mechanical Control of Polaritonic States in Lead Halide Perovskite Phonons Strongly Coupled in THz Microcavity.

We demonstrate the generation and control of polaritonic states in perovskite phonon polaritons, which are strongly coupled in the middle of a flexible Fabry-Perot cavity. We fabricated flexible perovskite films on a microporous substrate coated with graphene oxide, which led to a virtually free-standing film incorporated into the microcavity. Rabi splitting was observed when the cavity resonance was in tune with that of the phonons. The Rabi splitting energy increased as the film thickness increased, reaching 1.9 meV, which is 2.4-fold higher than the criterion for the strong coupling regime. We obtained dispersion curves for various perovskite film thicknesses exhibiting two polariton branches; clear beats between the two polaritonic branches were observed in the time domain. Flexible cavity devices with perovskite phonons enable macroscopic control over the polaritonic energy states through bending processes, which add an additional degree of freedom in the manipulation of polaritonic devices.

Appropriateness of antibiotic use for patients with asymptomatic bacteriuria or urinary tract infection with positive urine culture: a retrospective observational multi-centre study in Korea.

BACKGROUND: Antibiotic resistance threatens public health worldwide, and inappropriate use of antibiotics is one of the main causes. AIM: To evaluate qualitative use of antibiotics in asymptomatic bacteriuria (ABU) and urinary tract infection (UTI). METHODS: Cases of positive urine culture (≥105 colony-forning units/mL) performed in inpatient, outpatient and emergency departments in April 2021 were screened in 26 hospitals in the Republic of Korea. The cases were classified as ABU, lower UTI and upper UTI. The appropriateness of antibiotic use was evaluated retrospectively by infectious disease specialists using quality indicators based on clinical guidelines for ABU and UTI. RESULTS: This study included a total of 2697 patients with ABU or UTI. The appropriateness of antibiotic use was assessed in 1157 patients with ABU, and in 677 and 863 patients with lower and upper UTI, respectively. Among the 1157 patients with ABU, 251 (22%) were prescribed antibiotics without appropriate indications. In 66 patients with ABU in which antibiotics were prescribed with appropriate indications, the duration was adequate in only 23 (34.8%) patients. The appropriateness of empirical and definite antibiotics was noted in 527 (77.8%) and 353 (68.0%) patients with lower UTI, and 745 (86.3%) and 583 (78.2%) patients with upper UTI, respectively. The duration of antibiotics was adequate in 321 (61.8%) patients with lower UTI and 576 (78.7%) patients with upper UTI. CONCLUSIONS: This nationwide qualitative assessment of antibiotic use in ABU and UTI revealed that antibiotics were often prescribed inappropriately, and the duration of antibiotics was unnecessarily prolonged.

Hormonal stimulation reduces numbers and impairs function of human uterine natural killer cells during implantation.

STUDY QUESTION: How does an altered maternal hormonal environment, such as that seen during superovulation with gonadotropins in ART, impact human uterine immune cell distribution and function during the window of implantation? SUMMARY ANSWER: Hormonal stimulation with gonadotropins alters abundance of maternal immune cells including uterine natural killer (uNK) cells and reduces uNK cell ability to promote extravillous trophoblast (EVT) invasion. WHAT IS KNOWN ALREADY: An altered maternal hormonal environment, seen following ART, can lead to increased risk for adverse perinatal outcomes associated with disordered placentation. Maternal immune cells play an essential role in invasion of EVTs, a process required for proper establishment of the placenta, and adverse perinatal outcomes have been associated with altered immune cell populations. How ART impacts maternal immune cells and whether this can in turn affect implantation and placentation in humans remain unknown. STUDY DESIGN, SIZE, DURATION: A prospective cohort study was carried out between 2018 and 2021 on 51 subjects: 20 from natural cycles 8 days after LH surge; and 31 from stimulated IVF cycles 7 days after egg retrieval. PARTICIPANTS/MATERIALS, SETTING, METHODS: Endometrial biopsies and peripheral blood samples were collected during the window of implantation in subjects with regular menstrual cycles or undergoing superovulation. Serum estradiol and progesterone levels were measured by chemiluminescent competitive immunoassay. Immune cell populations in blood and endometrium were analyzed using flow cytometry. uNK cells were purified using fluorescence-activated cell sorting and were subjected to RNA sequencing (RNA-seq). Functional changes in uNK cells due to hormonal stimulation were evaluated using the implantation-on-a-chip (IOC) device, a novel bioengineered platform using human primary cells that mimics early processes that occur during pregnancy in a physiologically relevant manner. Unpaired t-tests, one-way ANOVA, and pairwise multiple comparison tests were used to statistically evaluate differences. MAIN RESULTS AND THE ROLE OF CHANCE: Baseline characteristics were comparable for both groups. As expected, serum estradiol levels on the day of biopsy were significantly higher in stimulated (superovulated) patients (P = 0.0005). In the setting of superovulation, we found an endometrium-specific reduction in the density of bulk CD56+ uNK cells (P < 0.05), as well as in the uNK3 subpopulation (P = 0.025) specifically (CD103+ NK cells). In stimulated samples, we also found that the proportion of endometrial B cells was increased (P < 0.0001). Our findings were specific to the endometrium and not seen in peripheral blood. On the IOC device, uNK cells from naturally cycling secretory endometrium promote EVT invasion (P = 0.03). However, uNK cells from hormonally stimulated endometrium were unable to significantly promote EVT invasion, as measured by area of invasion, depth of invasion, and number of invaded EVTs by area. Bulk RNA-seq of sorted uNK cells from stimulated and unstimulated endometrium revealed changes in signaling pathways associated with immune cell trafficking/movement and inflammation. LIMITATIONS, REASONS FOR CAUTION: Patient numbers utilized for the study were low but were enough to identify significant overall population differences in select immune cell types. With additional power and deeper immune phenotyping, we may detect additional differences in immune cell composition of blood and endometrium in the setting of hormonal stimulation. Flow cytometry was performed on targeted immune cell populations that have shown involvement in early pregnancy. A more unbiased approach might identify changes in novel maternal immune cells not investigated in this study. We performed RNA-seq only on uNK cells, which demonstrated differences in gene expression. Ovarian stimulation may also impact gene expression and function of other subsets of immune cells, as well as other cell types within the endometrium. Finally, the IOC device, while a major improvement over existing in vitro methods to study early pregnancy, does not include all possible maternal cells present during early pregnancy, which could impact functional effects seen. Immune cells other than uNK cells may impact invasion of EVTs in vitro and in vivo, though these remain to be tested. WIDER IMPLICATIONS OF THE FINDINGS: These findings demonstrate that hormonal stimulation affects the distribution of uNK cells during the implantation window and reduces the proinvasive effects of uNK cells during early pregnancy. Our results provide a potential mechanism by which fresh IVF cycles may increase risk of disorders of placentation, previously linked to adverse perinatal outcomes. STUDY FUNDING/COMPETING INTEREST(S): Research reported in this publication was supported by the University of Pennsylvania University Research Funding (to M.M.), the Eunice Kennedy Shriver National Institute of Child Health and Human Development (P50HD068157 to M.M., S.S., and S.M.), National Center for Advancing Translational Sciences of the National Institutes of Health (TL1TR001880 to J.K.), the Institute for Translational Medicine and Therapeutics of the Perelman School of Medicine at the University of Pennsylvania, the Children's Hospital of Philadelphia Research Institute (to S.M.G.), and the National Institute of Allergy and Infectious Diseases (K08AI151265 to S.M.G.). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. All authors declare no conflict of interest. TRIAL REGISTRATION NUMBER: N/A.

Effect of pneumatic leg compression on post-induction hypotension in elderly patients undergoing robot-assisted laparoscopic prostatectomy: a double-blind randomised controlled trial.

Post-induction hypotension is common and associated with postoperative complications. We hypothesised that pneumatic leg compression reduces post-induction hypotension in elderly patients undergoing robot-assisted laparoscopic prostatectomy. In this double-blind randomised study, patients were allocated randomly to the pneumatic leg compression group (n = 50) or control (n = 50). In the intervention group, pneumatic leg compression was initiated before induction of anaesthesia. In the control group, pneumatic leg compression was initiated 20 min after anaesthesia induction. The primary outcome was the incidence of post-induction hypotension in these groups. Post-induction hypotension was defined as systolic blood pressure < 90 mmHg during the first 20 min after induction. Haemodynamic variables and area under the curve of post-induction systolic blood pressure over time were assessed. Complications associated with pneumatic leg compression were recorded, including: peripheral neuropathy; compartment syndrome; extensive bullae beneath the leg sleeves; and pulmonary thromboembolism. The incidence of post-induction hypotension decreased in the pneumatic leg compression group compared with that in the control group; 5 (10%) vs. 29 (58%), respectively, p < 0.001. In the pneumatic leg compression group, the lowest systolic, diastolic and mean blood pressures 20 min after induction of anaesthesia were significantly greater than the control group. Pneumatic leg compression resulted in an increased area under the curve of systolic blood pressure in the first 20 min after induction, p = 0.001. There were no pneumatic leg compression-related complications. Pneumatic leg compression reduced post-induction hypotension in elderly patients undergoing robot-assisted laparoscopic prostatectomy, suggesting that it is an effective and safe intervention to prevent post-induction hypotension among elderly patients undergoing general anaesthesia.

Comparative efficacy evaluation of disinfectants against severe acute respiratory syndrome coronavirus-2.

BACKGROUND: Disinfection is one of the most effective ways to block the rapid transmission of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Due to the prolonged coronavirus disease 2019 (COVID-19) pandemic, disinfectants have become crucial to prevent person-to-person transmission and decontaminate hands, clothes, facilities and equipment. However, there is a lack of accurate information on the virucidal activity of commercial disinfectants. AIM: To evaluate the virucidal efficacy of 72 commercially available disinfectants constituting 16 types of ingredients against SARS-CoV-2. METHODS: SARS-CoV-2 was tested with various concentrations of disinfectants at indicated exposure time points as recommended by the manufacturers. The 50% tissue culture infectious dose assay was used to calculate virus titre, and trypan blue staining and CCK-8 were used to assess cell viability after 3-5 days of SARS-CoV-2 infection. FINDINGS: This study found that disinfectants based on 83% ethanol, 60% propanol/ethanol, 0.00108-0.0011% sodium dichloroisocyanurate and 0.497% potassium peroxymonosulfate inactivated SARS-CoV-2 effectively and safely. Although disinfectants based on 0.05-0.4% benzalkonium chloride (BAC), 0.02-0.07% quaternary ammonium compound (QAC; 1:1), 0.4% BAC/didecyldimethylammonium chloride (DDAC), 0.28% benzethonium chloride concentrate/2-propanol, 0.0205-0.14% DDAC/polyhexamethylene biguanide hydrochloride (PHMB) and 0.5% hydrogen peroxide inactivated SARS-CoV-2 effectively, they exhibited cytotoxicity. Conversely, disinfectants based on 0.04-4% QAC (2:3), 0.00625% BAC/DDAC/PHMB, and 0.0205-0.14% and 0.0173% peracetic acid showed approximately 50% virucidal efficacy with no cytotoxicity. Citric acid (0.4%) did not inactivate SARS-CoV-2. CONCLUSION: These results indicate that most commercially available disinfectants exert a disinfectant effect against SARS-CoV-2. However, re-evaluation of the effective concentration and exposure time of certain disinfectants is needed, especially citric acid and peracetic acid.

National trends in the prevalence of hepatitis B and C in South Korea, before and during the COVID-19 pandemic (2007-2021) - a nationwide representative study.

OBJECTIVE: Due to the various changes caused by the COVID-19 pandemic, some infectious diseases showed different epidemiology and prevalence during the pandemic. However, there is a lack of comprehensive studies on trends in the prevalence of hepatitis B and C related to the pandemic. Thus, we compared the prevalence of hepatitis B and C before and during the COVID-19 pandemic in South Korea. SUBJECTS AND METHODS: We conducted a comprehensive trend analysis with a nationwide serial cross-sectional survey from 2007 to 2021 (n=86,931) using the Korea National Health and Nutrition Examination Survey (KNHANES). The changes in the prevalence of hepatitis B and C were evaluated using a weighted regression model to assess the impact of the COVID-19 pandemic. RESULTS: From 2007 to 2021, 86,931 Korean adults aged 19 or older were included in the KNHANES data. The prevalence of hepatitis B showed a declining trend until the onset of the pandemic (1.80% in 2007-2009; 1.08% in 2016-2019; and 1.01% in 2020), at which point this trend reversed (1.39% in 2021). The prevalence of hepatitis C remained stable (0.14% in 2007-2009 and 0.18% in 2016-2019), with no particular surge related to the COVID-19 pandemic (ßdiff, -0.002; 95% CI, -0.761 to 0.756). For hepatitis B, old age was identified as a pandemic-related vulnerable factor (ratio of odds ratio, 1.68; 95% CI, 1.05-2.70). CONCLUSIONS: In this study, unlike other infectious diseases, hepatitis B and C did not show a decreasing trend during the pandemic. In particular, hepatitis B showed a rebound trend during the pandemic, which was noticeable in those aged 60 or older. Further studies are needed to support these findings.

Differences in strategies for prevention of COVID-19 transmission in hospitals: nationwide survey results from the Republic of Korea.

BACKGROUND: Hospital infection control measures against coronavirus disease 2019 (COVID-19) are often based on expert discretion due to the lack of detailed guidelines. AIM: To survey the current strategies for preventing the transmission of COVID-19 in medical institutions. METHODS: Thirteen key issues related to the prevention of COVID-19 transmission within medical institutions were selected via discussion among infectious diseases specialists, and related critical questions were obtained following a review of national-level guidelines in government databases. Six hospitals had an open survey between 11th and 25th August 2020 to provide responses to these topics. An online questionnaire developed from these data was sent to infection control teams at 46 hospitals in South Korea between 31st January 2021 and 20th February 2021. FINDINGS: All 46 hospitals responded to the survey. All operated screening clinics, but 89.1% (41/46) allowed symptomatic patients without COVID-19-associated symptoms to visit general outpatient clinics. Most hospitals (87.2%, 34/39) conducted polymerase chain reaction (PCR) tests for all hospitalized patients. Of 35/46 (76.1%) hospitals with pre-emptive isolation policies for hospitalized patients, 31 (88.6%) released patients from isolation after a single negative PCR test, while most (76.9%, 20/26) allowed shared-room accommodation for patients meeting the national criteria for release from isolation despite positive PCR results with above cycle threshold values (34.6%, 9/26), or after a certain period that satisfied the national criteria (26.9%, 7/26). CONCLUSION: Individual hospitals in South Korea are currently relying on experience to frame relevant guidelines, and responded differently to some infection control issues on hospital settings during the COVID-19 pandemic.

Evaluation of zone disinfection by air-passable plasma filter in a novel chamber model.

BACKGROUND: Disinfection of shared spaces has become essential to minimize the spread of various diseases. An efficient disinfection device that can simultaneously inactivate airborne bacteria and surface-adhered bacteria in an enclosed space is required. AIM: An air-passable plasma filter (APF) was developed and applied to a chamber model to evaluate the efficacy of zone disinfection. METHODS: The 60 L chamber consisted of a nebulizer, circulation fans, temperature and humidity monitors, an air-sampling port with a sealed gate, airborne bacteria-trapping media, and a built-in fan for evaluation. After spraying each bacterial strain (Escherichia coli, Staphylococcus epidermidis, and Mycobacterium smegmatis) as a bioaerosol, airborne and surface-attached bacteria were quantified simultaneously to evaluate the zone-disinfection effect of APF. FINDINGS: The operation of APF in the 60 L chamber showed a complete zone-disinfection effect for E. coli (10 min), S. epidermidis (10 min), and M. smegmatis (60 min) present in the air and on the walls at various locations. The time required to completely disinfect each of the airborne bacteria and surface-attached bacteria within the same space was different. CONCLUSION: APF has the potential to exhibit significant germicidal effects on various micro-organisms and can be an effective alternative for disinfection of enclosed spaces.

What does family involvement in care provision look like across hospital settings in Bangladesh, Indonesia, and South Korea?

BACKGROUND: Family members provide care whilst staying in the patient's room across a range of cultural settings, irrespective of resource availability in many Asian countries. This has been reported as a contributing factor to the spread of several outbreaks, including COVID-19. Despite these reports, very little is known about the risk of healthcare-associated infection (HAI) transmission related to the involvement of family and private carers in the clinical setting. As a starting point to understanding this issue, this study aimed to provide insights regarding the patient care activities undertaken by family and private carers and the guidance provided to these carers around infection control measures in hospitals located in Bangladesh, Indonesia, and South Korea. METHOD: A qualitative study involving 57 semi-structured interviews was undertaken in five tertiary level hospitals across the selected countries. Two groups of individuals were interviewed: (1) patients and their family carers and private carers; and (2) healthcare workers, including doctors, nurses, hospital managers and staff members. Drawing upon the principles of grounded theory, an inductive approach to data analysis using thematic analysis was adopted. RESULTS: Five main themes were generated from the analysis of the data: (1) expectation of family carers staying with a patient; (2) residing in the patient's environment: (3) caring activities undertaken by family carers; (4) supporting and educating family carers and (5) communication around healthcare-associated infection and infection prevention and control. CONCLUSION: Based on the types of activities being undertaken, coupled with the length of time family and private carers are residing within the clinical setting, coupled with an apparent lack of guidance being given around IPC, more needs to be done to ensure that these carers are not being inadvertently exposed to HAI's or other occupational risks.

Scaffold printing using biodegradable poly(1,4-butylene carbonate) ink: printability, in vivo physicochemical properties, and biocompatibility.

This study is the first to assess the applicability of biodegradable poly(1,4-butylene carbonate) (PBC) as a printing ink for fused deposition modeling (FDM). Here, PBC was successfully prepared via the bulk polycondensation of 1,4-butanediol and dimethyl carbonate. PBC was melted above 150°C in the heating chamber of an FDM printer, after which it flowed from the printing nozzle upon applying pressure and solidified at room temperature to create a three-dimensional (3D) scaffold structure. A 3D scaffold exactly matching the program design was obtained by controlling the temperature and pressure of the FDM printer. The compressive moduli of the printed PBC scaffold decreased as a function of implantation time. The printed PBC scaffold exhibited good in vitro biocompatibility, as well as in vivo neotissue formation and little host tissue response, which was proportional to the gradual biodegradation. Collectively, our findings demonstrated the feasibility of PBC as a suitable printing ink candidate for the creation of scaffolds via FDM printing.

Impact of COVID-19 on TB epidemiology in South Korea.

SETTING: Five referral hospitals, South Korea.OBJECTIVE: To assess epidemiological changes in TB before and during the COVID-19 pandemic.DESIGN: This was a multicentre cohort study of 3,969 patients diagnosed with TB.RESULTS: We analysed 3,453 patients diagnosed with TB prior to the COVID-19 pandemic (January 2016-February 2020) and 516 during the pandemic (March-November 2020). During the pandemic, the number of patients visits declined by 15% from the previous 4-year average, and the number of patients diagnosed with TB decreased by 17%. Patients diagnosed during the pandemic were older than those diagnosed before the pandemic (mean age, 60.2 vs. 56.6 years, P < 0.001). The proportion of patients to have primary TB at a younger age (births after 1980) among those diagnosed with TB was significantly lower during the pandemic than before (17.8% in 2020 vs. 23.5% in 2016, 24.0% in 2017, 22.5% in 2018, 23.5% in 2019; P = 0.005).CONCLUSIONS: The COVID-19 pandemic resulted in a reduction in the number of visits to respiratory departments, leading to fewer patients being diagnosed with TB. However, our results suggest that universal personal preventive measures help to suppress TB transmission in regions with intermediate TB burden.

The potential cytotoxic effects of urban particle matter on olfaction.

BACKGROUND: Urban particulate matter (UPM) in ambient air is implicated in a variety of human health issues worldwide, however, few studies exist on the effect of UPM on the olfactory system. This study aimed to identify the factors affecting the destruction of the olfactory system in a mouse model following UPM exposure. METHODS: Mice were divided into: control and four UPM-exposed groups (200 µg UPM at 1 and 2 weeks, and 400 µg UPM at 1 and 2 weeks [standard reference material 1649b; average particle diameter 10.5 µm]). The olfactory neuroepithelium was harvested for histologic examination, gene ontology, quantitative real-time polymerase chain reaction, and western blotting. RESULTS: Compared to the control group, olfactory marker protein, Olfr1507, ADCY3, and GNAL mRNA levels were lower, and S-100, CNPase, NGFRAP1, BDNF, and TACR3 mRNA levels were higher in the olfactory neuroepithelium of the UPM groups. Moderately positive correlation was present between the 1- and 2-week groups. After analyzing the 200 and 400 UPM groups separately, the strength of the association between the 200 UPM 1- and 2-week groups was moderately positive. No differences was present in the neuroepithelial inflammatory marker levels between the UPM and control groups. CONCLUSIONS: UPM could have cytotoxic effects on the olfactory epithelium. The exposure time and particular concentration of UPM exposure could affect the degree of destruction of the olfactory neuroepithelium. The olfactory regeneration mechanism could be related to the neurotrophic factors, olfactory ensheathing cell stimulation, and trigeminal nerve support.

A therapeutic intervention for Alzheimer's disease using ginsenoside Rg3: its role in M2 microglial activation and non-amyloidogenesis.

Previously, we have reported that ginsenoside Rg3 has typical activities for neuroprotection and Aß42 clearance by modulating microglia. In this study, we determined the pivotal role of ginsenoside Rg3 in microglia and neuronal cells. In human microglia, Rg3 and its stereoisomers significantly restored inflammatory M1 to normal M0 state and promoted M2 activation by up-regulating acute cytokines such as interleukin-10 and Arginase 1. Moreover, scavenger receptor type A (SRA) was significantly elevated in the presence of ginsenoside Rg3 and 20(S)-Rg3. This indicated that ginsenoside Rg3 could play a crucial role in Aß uptake and clearance under activated M2 state. We also observed that soluble amyloid precursor protein-alpha (sAPPα) and ADAM10 levels were increased in APP swe-transfected Nuro-2a neuronal cells, whereas sAPPß was not processed, suggesting that ginsenoside Rg3 was involved in non-amyloidogenic processing. In immunocytochemistry, SRA and a disintegrin and metalloproteinase 10 (desintegrin and metalloproteinase-containing protein 10, ADAM10) were coincidently upregulated in the presence of ginsenoside Rg3 and its stereoisomers compared to those in normal control. Taken together, these results suggested that ginsenoside Rg3 could boost acute activation of microglia, promote Aß uptake, and elevate the sAPPα processing under activated M2 state. Although in vivo studies need to be performed, it is certain that ginsenoside Rg3 is highly involved in ameliorating the pathogenesis of neurodegeneration and can be a promising candidate for treating Alzheimer's disease as a new therapeutic intervention.

Cell-free culture supernatant of Lactobacillus curvatus Wikim38 inhibits RANKL-induced osteoclast differentiation and ameliorates bone loss in ovariectomized mice.

This study was conducted to investigate the inhibitory effects of the cell-free culture supernatant of Lactobacillus curvatus Wikim 38 (LC38-CS) on RANKL-induced osteoclast differentiation and bone loss in a mice model of ovariectomy-induced post-menopausal osteoporosis. LC38-CS inhibited the RANKL-induced differentiation of bone marrow-derived macrophages (BMDMs) into osteoclasts in a dose-dependent manner. F-actin ring formation and bone resorption were also reduced by LC38-CS treatment of RANKL-treated BMDMs. In addition, LC38-CS decreased the RANKL-induced activation of the TRAF6/NF-κB/MAPKs axis at the early stage and the expression of osteoclastogenesis-related genes in BMDMs treated with RANKL. PRMT1 and ADMA levels, new biomarkers for osteoclastogenesis, were decreased by LC38-CS treatment. The administration of LC38-CS increased bone volume and bone mineral density in ovariectomized mice in µ-CT analysis. These findings suggest that LC38-CS inhibited RANKL-induced osteoclast differentiation by the downregulation of molecular mechanisms and exerted anti-osteoporotic effects.

Suppressed Degradation and Enhanced Performance of CsPbI3 Perovskite Quantum Dot Solar Cells via Engineering of Electron Transport Layers.

CsPbI3 perovskite quantum dots (CsPbI3-PQDs) have recently come into focus as a light-harvesting material that can act as a platform through which to combine the material advantages of both perovskites and QDs. However, the low cubic-phase stability of CsPbI3-PQDs in ambient conditions has been recognized as a factor that inhibits device stability. TiO2 nanoparticles are the most regularly used materials as an electron transport layer (ETL) in CsPbI3-PQD photovoltaics; however, we found that TiO2 can facilitate the cubic-phase degradation of CsPbI3-PQDs due to its vigorous photocatalytic activity. To address these issues, we have developed chloride-passivated SnO2 QDs (Cl@SnO2 QDs), which have low photocatalytic activity and few surface traps, to suppress the cubic-phase degradation of CsPbI3-PQDs. Given these advantages, the CsPbI3-PQD solar cells based on Cl@SnO2 ETLs show significantly improved device operational stability (under conditions of 50% relative humidity and 1-sun illumination), compared to those based on TiO2 ETLs. In addition, the Cl@SnO2-based devices showed improved open circuit voltage and photocurrent density, resulting in enhanced power conversion efficiency (PCE) up to 14.5% compared to that of TiO2-based control devices (PCE of 13.8%).

Survival of oral mucosal melanoma according to treatment, tumour resection margin, and metastases.

Because of the poor prognosis and of oral mucosal melanoma, and patients' short survival, large, randomised, clinical studies are difficult. We have investigated its demographic characteristics and analysed the effect of treatment, resection margins, and metastases on survival. We recorded age, sex, site of primary tumour, and types of treatment, survival, and metastases in 74 patients treated at the Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital. Survival was analysed based on bony invasion, depth of invasion, and resection margins, and we found that it varied depending on the primary site (p=0.002), and declined with liver (p=0.001) or brain (p=0.033) metastases. The two-year survival according to the primary site was as follows: palate 85% (n=32), anterior maxillary gingiva 53% (n=13), mandible 58% (n=13), and posterior maxillary gingival 74% (n=10) and buccal mucosa 50% (n=4). The two-year survival was 34% (n=8) in patients with liver metastases and 23% (n=7) in patients with brain metastases. In cases of bony invasion (p=0.005), depth of invasion (p=0.042), unclear resection margin (p=0.023), or higher T stages (p=0.009), the survival declined considerably. Neck dissection did not affect survival (p=0.343). Survival of the patients given chemotherapy was significantly lower (p=0.013) and the two-year survival was 54.0%. The patients given radiotherapy showed no significant difference in survival compared with those not given radiotherapy (p=0.107). In conclusion, primary site, bony invasion, resection margins, depth of invasion and systemic metastases were critical to predict prognosis and selection of treatment of oral mucosal melanoma.

Identifying different types of microorganisms with terahertz spectroscopy.

Most microbial detection techniques require pretreatment, such as fluorescent labeling and cultivation processes. Here, we propose novel tools for classifying and identifying microorganisms such as molds, yeasts, and bacteria based on their intrinsic dielectric constants in the THz frequency range. We first measured the dielectric constant of films that consisted of a wide range of microbial species, and extracted the values for the individual microbes using the effective medium theory. The dielectric constant of the molds was 1.24-1.85, which was lower than that of bacteria ranging from 2.75-4.11. The yeasts exhibited particularly high dielectric constants reaching 5.63-5.97, which were even higher than that of water. These values were consistent with the results of low-density measurements in an aqueous environment using microfluidic metamaterials. In particular, a blue shift in the metamaterial resonance occurred for molds and bacteria, whereas the molds have higher contrast relative to bacteria in the aqueous environment. By contrast, the deposition of the yeasts induced a red shift because their dielectric constant was higher than that of water. Finally, we measured the dielectric constants of peptidoglycan and polysaccharides such as chitin, α-glucan, and ß-glucans (with short and long branches), and confirmed that cell wall composition was the main cause of the observed differences in dielectric constants for different types of microorganisms.

Effect of heat-killed Enterococcus faecalis EF-2001 on ethanol-induced acute gastric injury in mice: Protective effect of EF-2001 on acute gastric ulcer.

Enterococcus faecalis is a facultative anaerobic gram-positive commensal bacterium common in the gastrointestinal tract of animals and humans. This study aimed to investigate the protective effects of heat-killed E. faecalis EF-2001 (EF-2001) on acute gastric ulcer using a murine model of ethanol (EtOH)-induced acute gastric injury. EF-2001 (20, 40, and 80 mg/kg/day) was administered by oral gavage for 5 days before EtOH treatment (10 mL/kg body weight). EF-2001 effectively attenuated EtOH-induced gastric mucosal injury with reduced gastric mucosal ulcer and histological damage score. Pretreatment of EF-2001 markedly suppressed the phosphorylation of mitogen-activated protein kinases (MAPKs; ERK1/2, JNK, and p38MAPK). In addition, EF-2001 significantly inhibited phosphorylation of nuclear factor kappa B (NF-κB) and subsequently suppressed the upregulation of inducible nitric oxide synthase, cyclooxygenase-2, tumor necrosis factor alpha, interleukin 1 beta, and interleukin 6 in gastric tissues. Taken together, these results suggest that EF-2001 exerts a gastroprotective effect against acute gastric injury, and the underlying mechanism might be associated with the suppression of MAPKs and NF-κB signaling and consequent reduction of pro-inflammatory mediators or cytokines.

Akt1-Mediated Phosphorylation of RBP-Jk Controls Notch1 Signaling.

The Notch1 signaling pathway plays a crucial role in determining cell fate, including cell growth and differentiation. In this study, we demonstrated that the antagonistic action of RTK (receptor tyrosine kinase) signaling pathway on the Notch1 signaling pathway is mediated via Ras-PI3K-Akt1. The PI3K-Akt1 signaling pathway was shown to inhibit Notch1 signaling via phosphorylation of RBP-Jk. We observed not only reduced association between Notch1 and RBP-Jk, but also suppression of the Notch1 transcriptional activity. Our results demonstrated that Akt1 functions as a natural inhibitor of the Notch1 signaling pathway via phosphorylation of RBP-Jk.