Analytical method development and dermal absorption of gallic acid, a hair dye ingredient.

Gallic acid (GA) is a phenolic compound known as 3,4,5-trihydroxybenzoic acid. GA is used as a hair dye ingredient. It is limited to be below 4.0% in Korea. Dermal absorption rate of GA has not been reported yet. In this study, an analytical method for GA was developed and validated using high-performance liquid chromatography (HPLC) in various matrices of swab, stratum corneum (SC), skin (dermis + epidermis), and receptor fluid (RF). HPLC analysis showed acceptable linearity (r2 = 0.999-0.9998), accuracy (90.3-112.8%), and precision (0.7-13.6%) in accordance with validation guidelines by Korea Ministry of Food and Drug Safety (MFDS). The dermal absorption rate of GA was determined using Franz diffuse cells. GA (4.0%) was applied to mini pig skin of 10 µl/cm2. After 30 min application, the GA was wiped out and receptor fluid sampling was continued until 24 h. After 24 h, skin was wiped off with swab and SC was collected using tape stripping. All samples were extracted with ethanol and analyzed using the validated method. The total dermal absorption rate of GA was determined to be 2.6 ± 1.3% (24 h).

Clinical presentation, viral shedding, and neutralizing antibody responses of mpox cases in South Korea: Single center experience.

BACKGROUND: A global mpox outbreak occurred in 2022, and a domestic outbreak started in South Korea in April 2023. This study aimed to evaluate the clinical characteristics, viral shedding, and immune response of mpox in South Korea. METHODS: Patients hospitalized with mpox in the National Medical Center between September 2022 and June 2023 were included in this study. Oropharyngeal (OP), anogenital lesion (AL), and skin lesion (SL) swabs and blood samples were collected, and monkeypox virus (MPXV) DNA using real-time polymerase chain reaction (RT-PCR) and culture assays were performed. Neutralizing antibodies (NAbs) against MPXV A.2.1, B.1.1, and B.1.3 were detected using plaque reduction neutralization tests. RESULTS: Eighteen patients were enrolled, of whom 17 (94.4 %) were male, with a median (IQR) age of 32.5 (24-51) years. While nine (50 %) were HIV-infected individuals, none of them revealed CD4+ counts less than 200 cells/µL. MPXV DNA was detected in 87.3 % and 82.7 % of patient's ALs and SLs, respectively, until 2 weeks after symptom onset. While MPXV was isolated for up to 15 days in all three sample types, the culture positivity decreased to 53.8 % and 42.9 % in ALs and SLs after 10 days, respectively, and 28.6 % and 22.2 %, respectively, after 2 weeks from symptom onset. The NAb titers against MPXV A.2.1 were significantly lower than those against B.1.1 and B.1.3. CONCLUSIONS: Infectious MPXV was isolated from various anatomical sites up to 15 days after symptom onset. The MPXV NAb response was varied among different lineages, and this implies limited cross-lineage protection.

Severe mpox requiring colostomy in a patient with advanced HIV disease: a case report and literature review.

This severe monkeypox case described a 23-year-old male with advanced HIV-1 disease presenting perirectal abscess, extensive anal ulcerative lesions requiring colostomy, and tecovirimat resistance. Radiologically non-liquefied perirectal abscess presented diagnostic challenges highlighting the complexity of aggressive monkeypox manifestations in immunocompromised individuals.

Analytical Method Development and Dermal Absorption of 4-Amino-3-Nitrophenol (4A3NP), a Hair Dye Ingredient under the Oxidative or Non-Oxidative Condition.

The chemical 4-amino-3-nitrophenol (4A3NP) is classified as an amino nitrophenol and is primarily utilized as an ingredient in hair dye colorants. In Korea and Europe, it is exclusively used in non-oxidative or oxidative hair dye formulations, with maximum allowable concentrations of 1% and 1.5%, respectively. Despite this widespread use, risk assessment of 4A3NP has not been completed due to the lack of proper dermal absorption data. Therefore, in this study, both the analytical method validation and in vitro dermal absorption study of 4A3NP were conducted following the guidelines provided by the Korea Ministry of Food and Drug Safety (MFDS). Before proceeding with the dermal absorption study, analytical methods were developed for the quantitation of 4A3NP through multiple reaction monitoring (MRM) via liquid chromatography-mass spectrometry (LC-MS) in various matrices, including swab wash (WASH), stratum corneum (SC), skin (SKIN, comprising the dermis and epidermis), and receptor fluid (RF). These developed methods demonstrated excellent linearity (R2 = 0.9962-0.9993), accuracy (93.5-111.73%), and precision (1.7-14.46%) in accordance with the validation guidelines.The dermal absorption of 4A3NP was determined using Franz diffusion cells with mini-pig skin as the barrier. Under both non-oxidative and oxidative (6% hydrogen peroxide (H2O2): water, 1:1) hair dye conditions, 1% and 1.5% concentrations of 4A3NP were applied to the skin at a rate of 10 µL/cm2, respectively. The total dermal absorption rates of 4A3NP under non-oxidative (1%) and oxidative (1.5%) conditions were determined to be 5.62 ± 2.19% (5.62 ± 2.19 µg/cm2) and 2.83 ± 1.48% (4.24 ± 2.21 µg/cm2), respectively.

Repeated-dose toxicity and toxicokinetic study of isobutylparaben in rats subcutaneously treated for 13 weeks.

Parabens have historically served as antimicrobial preservatives in a range of consumables such as food, beverages, medications, and personal care products due to their broad-spectrum antibacterial and antifungal properties. Traditionally, these compounds were believed to exhibit low toxicity, causing minimal irritation, and possessing limited sensitization potential. However, recent evidence suggests that parabens might function as endocrine-disrupting chemicals (EDCs). Consequently, extensive research is underway to elucidate potential human health implications arising from exposure to these substances. Among these parabens, particular concerns have been raised regarding the potential adverse effects of iso-butylparaben (IBP). Studies have specifically highlighted its potential for inducing hormonal disruption, significant ocular damage, and allergic skin reactions. This study aimed to evaluate the prolonged systemic toxicity, semen quality, and estrus cycle in relation to endocrine disruption endpoints, alongside assessing the toxicokinetic behavior of IBP in Sprague-Dawley rats following a 13-week repeated subcutaneous administration. The rats were administered either the vehicle (4% Tween 80) or IBP at dosage levels of 2, 10, and 50 mg/kg/day for 13 weeks. Blood collection for toxicokinetic study was conducted on three specified days: day 1 (1st), day 30 (2nd), and day 91 (3rd). Systemic toxicity assessment and potential endocrine effects were based on various parameters including mortality rates, clinical signs, body weights, food and water consumption, ophthalmological findings, urinalysis, hematological and clinical biochemistry tests, organ weights, necropsy and histopathological findings, estrus cycle regularity, semen quality, and toxicokinetic behavior. The findings revealed that IBP induced local irritation at the injection site in males at doses ≥ 10 mg/kg/day and in females at 50 mg/kg/day; however, systemic toxicity was not observed. Consequently, the no-observed-adverse-effect level (NOAEL) for IBP was determined to be 50 mg/kg/day in rats of both sexes, indicating no impact on the endocrine system. The toxicokinetics of IBP exhibited dose-dependent systemic exposure, reaching a maximum dose of 50 mg/kg/day, and repeated administration over 13 weeks showed no signs of accumulation.

A Motivational Technology Perspective on the Use of Smart Wrist-Worn Wearables for Postpartum Exercise and Weight Management.

Exercise and weight management is crucial in preventing postpartum depression and long-term obesity that carries the risk of chronic illness among postpartum women. Although communication devices, such as a smart wrist-worn wearable (SWW), can help users be more physically active, the extent to which postpartum women might benefit from this technology is unknown. We examined how SWWs promoted exercise and helped postpartum women return to pre-pregnancy weight. We tested a model based on the premise that a motivational device that prompts users to engage with it can establish healthy daily routines. An online survey of 309 postpartum women who were living in the United States and were current users of SWWs revealed that the device encouraged them to spend time completing workout goals. Technological affordances (i.e. customization, navigability, and interactivity) and subsequent user engagement with the device positively predicted total workout hours among postpartum women. We present practical implications for postpartum care programs and smart wearable developers.

A long-term storable gel-laden chip composite built in a multi-well plate enablingin situcell encapsulation for high-throughput liver model.

Hydrogels are widely used as scaffold materials for constructingin vitrothree-dimensional microphysiological systems. However, their high sensitivity to various external cues hinders the development of hydrogel-laden, microscale, and high-throughput chips. Here, we have developed a long-term storable gel-laden chip composite built in a multi-well plate, which enablesin situcell encapsulation and facilitates high-throughput analysis. Through optimized chemical crosslinking and freeze-drying method (C/FD), we have achieved a high-quality of gel-laden chip composite with excellent transparency, uniform porosity, and appropriate swelling and mechanical characteristics. Besides collagen, decellularized extracellular matrix with tissue-specific biochemical compound has been applied as chip composite. As a ready-to-use platform,in situcell encapsulation within the gel has been achieved through capillary force generated during gel reswelling. The liver-mimetic chip composite, comprising HepG2 cells or primary hepatocytes, has demonstrated favorable hepatic functionality and high sensitivity in drug testing. The developed fabrication process with improved stability of gels and storability allows chip composites to be stored at a wide range of temperatures for up to 28 d without any deformation, demonstrating off-the-shelf products. Consequently, this provides an exceptionally simple and long-term storable platform that can be utilized for an efficient tissue-specific modeling and various biomedical applications.

The forecasted prevalence of comorbidities and multimorbidity in people with HIV in the United States through the year 2030: A modeling study.

BACKGROUND: Estimating the medical complexity of people aging with HIV can inform clinical programs and policy to meet future healthcare needs. The objective of our study was to forecast the prevalence of comorbidities and multimorbidity among people with HIV (PWH) using antiretroviral therapy (ART) in the United States (US) through 2030. METHODS AND FINDINGS: Using the PEARL model-an agent-based simulation of PWH who have initiated ART in the US-the prevalence of anxiety, depression, stage ≥3 chronic kidney disease (CKD), dyslipidemia, diabetes, hypertension, cancer, end-stage liver disease (ESLD), myocardial infarction (MI), and multimorbidity (≥2 mental or physical comorbidities, other than HIV) were forecasted through 2030. Simulations were informed by the US CDC HIV surveillance data of new HIV diagnosis and the longitudinal North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD) data on risk of comorbidities from 2009 to 2017. The simulated population represented 15 subgroups of PWH including Hispanic, non-Hispanic White (White), and non-Hispanic Black/African American (Black/AA) men who have sex with men (MSM), men and women with history of injection drug use and heterosexual men and women. Simulations were replicated for 200 runs and forecasted outcomes are presented as median values (95% uncertainty ranges are presented in the Supporting information). In 2020, PEARL forecasted a median population of 670,000 individuals receiving ART in the US, of whom 9% men and 4% women with history of injection drug use, 60% MSM, 8% heterosexual men, and 19% heterosexual women. Additionally, 44% were Black/AA, 32% White, and 23% Hispanic. Along with a gradual rise in population size of PWH receiving ART-reaching 908,000 individuals by 2030-PEARL forecasted a surge in prevalence of most comorbidities to 2030. Depression and/or anxiety was high and increased from 60% in 2020 to 64% in 2030. Hypertension decreased while dyslipidemia, diabetes, CKD, and MI increased. There was little change in prevalence of cancer and ESLD. The forecasted multimorbidity among PWH receiving ART increased from 63% in 2020 to 70% in 2030. There was heterogeneity in trends across subgroups. Among Black women with history of injection drug use in 2030 (oldest demographic subgroup with median age of 66 year), dyslipidemia, CKD, hypertension, diabetes, anxiety, and depression were most prevalent, with 92% experiencing multimorbidity. Among Black MSM in 2030 (youngest demographic subgroup with median age of 42 year), depression and CKD were highly prevalent, with 57% experiencing multimorbidity. These results are limited by the assumption that trends in new HIV diagnoses, mortality, and comorbidity risk observed in 2009 to 2017 will persist through 2030; influences occurring outside this period are not accounted for in the forecasts. CONCLUSIONS: The PEARL forecasts suggest a continued rise in comorbidity and multimorbidity prevalence to 2030, marked by heterogeneities across race/ethnicity, gender, and HIV acquisition risk subgroups. HIV clinicians must stay current on the ever-changing comorbidities-specific guidelines to provide guideline-recommended care. HIV clinical directors should ensure linkages to subspecialty care within the clinic or by referral. HIV policy decision-makers must allocate resources and support extended clinical capacity to meet the healthcare needs of people aging with HIV.

A Simple Laser-Induced Breakdown Spectroscopy Method for Quantification and Classification of Edible Sea Salts Assisted by Surface-Hydrophilicity-Enhanced Silicon Wafer Substrates.

Salt, one of the most commonly consumed food additives worldwide, is produced in many countries. The chemical composition of edible salts is essential information for quality assessment and origin distinction. In this work, a simple laser-induced breakdown spectroscopy instrument was assembled with a diode-pumped solid-state laser and a miniature spectrometer. Its performances in analyzing Mg and Ca in six popular edible sea salts consumed in South Korea and classification of the products were investigated. Each salt was dissolved in water and a tiny amount of the solution was dropped and dried on the hydrophilicity-enhanced silicon wafer substrate, providing homogeneous distribution of salt crystals. Strong Mg II and Ca II emissions were chosen for both quantification and classification. Calibration curves could be constructed with limits-of-detection of 87 mg/kg for Mg and 45 mg/kg for Ca. Also, the Mg II and Ca II emission peak intensities were used in a k-nearest neighbors model providing 98.6% classification accuracy. In both quantification and classification, intensity normalization using a Na I emission line as a reference signal was effective. A concept of interclass distance was introduced, and the increase in the classification accuracy due to the intensity normalization was rationalized based on it. Our methodology will be useful for analyzing major mineral nutrients in various food materials in liquid phase or soluble in water, including salts.

Prediction of skin sensitization using machine learning.

As global awareness of animal welfare spreads, the development of alternative animal test models is increasingly necessary. The purpose of this study was to develop a practical machine-learning model for skin sensitization using three physicochemical properties of the chemicals: surface tension, melting point, and molecular weight. In this study, a total of 482 chemicals with local lymph node assay results were collected, and 297 datasets with 6 physico-chemical properties were used to develop Random Forest (RF) model for skin sensitization. The developed model was validated with 45 fragrance allergens announced by European Commission. The validation results showed that RF achieved better or similar classification performance with f1-scores of 54% for penal, 82% for ternary, and 96% for binary compared with Support Vector Machine (SVM) (penal, 41%; ternary, 81%; binary, 93%), QSARs (ChemTunes, 72% for ternary; OECD Toolbox, 89% for binary), and a linear model (Kim et al., 2020) (41% for penal), and we recommend the ternary classification based on Global Harmonized System providing more detailed and precise information. In the further study, the proposed model results were experimentally validated with the Direct Peptide Reactivity Assay (DPRA, OECD TG 442C approved model), and the results showed a similar tendency. We anticipate that this study will help to easily and quickly screen chemical sensitization hazards.

Effects of Particulate Matter Exposure on the Eustachian Tube and Middle Ear Mucosa of Rats.

OBJECTIVES: Particulate matter (PM) is a risk factor for various diseases. Recent studies have established an association between otitis media (OM) and PM exposure. To confirm this relationship, we developed a novel exposure model designed to control the concentration of PM, and we observed the effects of PM exposure on the Eustachian tube (ET) and middle ear mucosa of rats. METHODS: Forty healthy, 10-week-old, male Sprague-Dawley rats were divided into 3-day, 7-day, 14-day exposure, and control groups (each, n=10). The rats were exposed to incense smoke as the PM source for 3 hours per day. After exposure, bilateral ETs and mastoid bullae were harvested, and histopathological findings were compared using microscopy and transmission electron microscopy (TEM). The expression levels of interleukin (IL)-1ß, IL-6, tumor necrosis factor-α, and vascular endothelial growth factor (VEGF) in the middle ear mucosa of each group were compared using real-time reverse transcription polymerase chain reaction (RT-PCR). RESULTS: In the ET mucosa of the exposure group, the goblet cell count significantly increased after PM exposure (P=0.032). In the middle ear mucosa, subepithelial space thickening, increased angio-capillary tissue, and inflammatory cell infiltration were observed. Moreover, the thickness of the middle ear mucosa in the exposure groups increased compared to the control group (P<0.01). The TEM findings showed PM particles on the surface of the ET and middle ear mucosa, and RT-PCR revealed that messenger RNA (mRNA) expression of IL-1ß significantly increased in the 3-day and 7-day exposure groups compared to the control group (P=0.035). VEGF expression significantly increased in the 7-day exposure group compared to the control and 3-day exposure groups (P<0.01). CONCLUSION: The ET and middle ear mucosa of rats showed histopathologic changes after acute exposure to PM that directly reached the ET and middle ear mucosa. Therefore, acute exposure to PM may play a role in the development of OM.

Analytical method development and dermal absorption of 2-amino-5-nitrophenol (2A5NP), a hair dye ingredient under oxidative condition.

Although 2-amino-5-nitrophenol (2A5NP) is one of the ingredients of hair dye, there has been no information on the dermal absorption rate of 2A5NP. 2A5NP is managed at less than 1.5% in Korea and Japan. In this study, analytical methods were developed and validated using high-performance liquid chromatography (HPLC) in various matrices of wash, swab, stratum corneum (SC), skin (dermis + epidermis), and receptor fluid (RF). Validation results were acceptable based on Korea Ministry of Food and Drug Safety (MFDS) guideline. The HPLC analysis showed a good linearity (r2 = 0.9992-0.9999), a high accuracy (93.1-110.2%), and a good precision (1.1-8.1%) in accordance with the validation guideline. Franz diffusion cell was used to determine dermal absorption of 2A5NP using mini pig skin. 2A5NP (1.5%) was applied to skin at 10 µl/cm2. For certain cosmetic ingredients such as hair dye with short exposure time, an interim wash step (after 30 min) was added during the study. After application for 30 min and 24 h, skin was wiped off with swab and SC was collected using tape stripping. RF was sampled at 0, 1, 2, 4, 8, 12, and 24 h. Total dermal absorption rate of 2A5NP (1.5%) was determined to be 13.6 ± 2.9%.

A Case of Human Mpox with Isolated Perianal Ulcers Development in Convalescent Phase.

A 35-year-old man who returned from Germany developed fever, generalized pain, severe anal pain, and generalized skin rash, confirmed to be monkeypox (mpox). While he was previously confirmed to be human immunodeficiency virus infected, antiretroviral therapy ensured his immunocompetence. The mpox-related prodromal symptoms disappeared before isolation, and subsequent several vesicular skin lesions healed after admission. While moderate anal pain persisted for a few days, it improved during hospitalization. The mpox virus was no longer detected in samples taken from the upper respiratory tract and skin by polymerase chain reaction upon admission. However, isolated perianal ulcers developed after admission without any other mpox-related symptoms or signs, and a viable mpox virus was isolated from these ulcers. Considering the novel feature of asynchronous mucocutaneous lesion development in the current mpox epidemic, meticulous physical examination of newly developing lesions, especially in anogenital areas, should be performed during mpox management.

Inflammatory Markers and Brain Volume in Patients with Post-traumatic Stress Disorder.

Objective: Posttraumatic stress disorder (PTSD) is characterized by increased inflammatory processing and altered brain volume. In this study, we investigated the relationship between inflammatory markers and brain volume in patients with PTSD. Methods: Forty-five patients with PTSD, and 70 healthy controls (HC) completed clinical assessments and self-reported psychopathology scales. Factors associated with inflammatory responses including brain-derived neurotrophic factor and four inflammatory biomarkers (C-reactive protein, cortisol, Interleukin-6, and homocysteine) and T1-magnetic resonance imaging of the brain were measured. Results: In the PTSD group, cortisol level was significantly lower (t = 2.438, p = 0.046) than that of the HC. Cortisol level was significantly negatively correlated with the left thalamus proper (r = -0.369, p = 0.035), right thalamus proper (r = -0.394, p = 0.014), right frontal pole (r = -0.348, p = 0.039), left occipital pole (r = -0.338, p = 0.044), and right superior occipital gyrus (r = -0.397, p = 0.008) in patients with PTSD. However, these significant correlations were not observed in HC. Conclusion: Our results indicate that increased cortisol level, even though its average level was lower than that of HC, is associated with smaller volumes of the thalamus, right frontal pole, left occipital pole, and right superior occipital gyrus in patients with PTSD. Cortisol, a major stress hormone, might be a reliable biomarker to brain volumes and pathophysiological pathways in patients with PTSD.

Causing trouble and being transmissible: COVID-19 survivors' experiences of stigma and discrimination in South Korea.

Background: The stigma associated with coronavirus disease (COVID-19) is relatively neglected in policies for handling the disease. Stigmatization occurs only within specific social contexts in local societies. Objective: This study aims to examine COVID-19 survivors' experiences of social stigma and discrimination in South Korea in the first 2 years of the pandemic. Methods: Semi-structured interviews were conducted. Results: Of 52 participants, 45 reported that they had to cope with stigma and discrimination in their intimate social relationships, workplaces, and children's schools, ranging from subtle actions to job loss. Sexual minorities who were involved in mass disease transmission in the early part of the pandemic experienced a higher level of stigmatization. The stigmatization dealt with in this study was related to two themes: survivors' sense of causing trouble and possibility of transmission. Conclusion: By intertwining this stigma with the experiences of public health measures through the voices of survivors, this study reveals the local context of East Asia in terms of culture-specific aspects of COVID-19-related stigma.

Understanding the Dynamics of Online Social Support Among Postpartum Mothers in Online Communities.

INTRODUCTION: Despite previous attempts to identify types of social support among postpartum mothers, researchers have overlooked how and why postpartum mothers seek and offer social support as well as the dynamics of participation in online communities. OBJECTIVE AND METHODS: The objective of the current study was to explore possible answers through grounded theory approach of interviews with 24 mothers who have experienced postpartum depression and psychological distress. RESULTS: The primary motivation to join the community was a desire for connectedness and reassurance. Initially engaged to seek information, users began to share not only informational and tangible support, but also emotional and esteem support as they gained comfort with their membership in these groups. CONCLUSION: Findings suggest that affirming normalcy while coping with postpartum distress is an integral part of the social support shared among postpartum mothers. Moreover, the findings indicated that to maximize the sustainability as well as the effectiveness of online communities for postpartum mothers, motivating silent users to participate and reciprocate is crucial.

What is already known Many postpartum mothers have joined online communities to exchange information and social support with fellow moms in the group. Previous studies have found various motivations for postpartum moms joining online communities and what types of social support they share. However, what motivates postpartum mothers to get involved, stay in or leave online communities based on level of satisfaction with those communities remains unclear.What this study can add to the literature Two major motivations among postpartum mothers to join online social support groups were a need to communicate to end their sense of isolation and a desire to gather information from experienced people. After gaining a sense of group reliability, they began posting to seek and provide support. Through experiencing and observing the exchange of support within the community, postpartum mothers felt more attached to the group. They also developed the need to reciprocate support through empathy based on their development of in-group identity. In addition, the motivation to reciprocate stemmed from enhanced confidence in their own knowledge of postpartum symptoms.

Lidocaine inhibits osteogenic differentiation of human dental pulp stem cells in vitro.

OBJECTIVE: Lidocaine is an amide local anaesthetic commonly used for pain control, however, few studies have investigated the effect of lidocaine on the osteogenic differentiation of human dental pulp stem cells (HDPSCs). The present study aimed to determine the effect of lidocaine on HDPSC viability and osteogenic differentiation. METHODS: HDPSCs were incubated with 0, 0.05, 0.2, 0.5, and 1 mM lidocaine for 24, 48 and 72 h, after which, MTT assays were performed. HDPSCs cultured with the above lidocaine concentrations and osteogenic differentiation medium for 7 and 14 days were stained for alkaline phosphatase (ALP). Protein and mRNA levels of relevant osteogenic factors (bone morphogenetic protein-2 [BMP-2] and runt-related transcription factor 2 [RUNX2]) were examined using western blotting and real-time reverse-transcription polymerase chain reaction, respectively. RESULTS: Lidocaine did not affect the viability of HDPSCs, however, lidocaine reduced ALP activity in HDPSCs. Levels of ALP, BMP-2, and RUNX2 mRNA were reduced with lidocaine, and levels of BMP-2 and RUNX2 proteins were decreased, versus controls. CONCLUSIONS: Lidocaine inhibits osteogenic differentiation markers in HDPSCs in vitro, even at low concentrations, without cytotoxicity. This study suggests that lidocaine may inhibit osteogenic differentiation in HDPSC-mediated regenerative medicine, including pulp regeneration and repair.

Feasibility of a Low-Power, Low-Resolution Laser-Induced Breakdown Spectroscopy Instrument for Analysis of Nickel Alloys: Quantification of the Major Alloying Elements and Classification.

A simple cost-effective laser-induced breakdown spectroscopy (LIBS) instrument was used for quantification of major elements in several nickel alloys and also sorting them. A compact low-power diode-pumped solid-state laser and a miniature low-resolution spectrometer were assembled for the LIBS instrument. Material properties of the nickel alloys depend mainly on the composition of the major elements, Ni, Cr, and Fe, ranging from a few to ∼60 wt%. The emission peaks at 547.7 nm, 520.4 nm, and 438.1 nm for Ni, Cr, and Fe, respectively, were chosen for this analysis. The analytical performance was found to be enough for the quantification of Ni, Cr, and Fe in the nickel alloys. Limits of detection and accuracy were estimated to be a few weight percent (wt%) and measurement precisions were less than 10% in terms of relative standard deviation. The calibration performance of this intensity-based method was compared with that of the "ratio method" which is used in conventional optical emission spectroscopy analyses. The comparison indicates that the intensity-based method is more appropriate with the low-performance LIBS instrument that detects emission peaks of only a few major elements. Also, multivariate modeling of the six different nickel alloy samples based on the emission peak intensities of Ni, Cr, and Fe was performed using k-nearest neighbors (KNN) and linear discriminant analysis (LDA). The KNN and ordinary LDA models showed 95.0% and 98.3% classification correctness for the separate test data set, respectively. To improve classification performance further, the two-step LDA model was trained. In this approach, the two closest sample classes responsible for the decrease in the classification correctness were separately modeled in the second step to exploit their difference effectively. The two-step LDA model showed 100% correctness in classifying the test objects. Our results indicate that such a low-performance LIBS instrument can be effectively utilized for quantitative analysis of the major elements in the nickel alloys and their rapid identification or sorting in combination with an appropriate multivariate modeling algorithm.

Effects of Dietary Habits on General and Abdominal Obesity in Community-dwelling Patients with Schizophrenia.

Objective: To investigate the effects of dietary habits on general and abdominal obesity in community-dwelling patients with schizophrenia spectrum disorder according to sex. Methods: A total of 270 patients with schizophrenia spectrum disorder registered at mental health welfare centers and rehabilitation facilities were recruited. General obesity was defined as a body mass index ≥ 30 kg/m2, and abdominal obesity was defined as a waist circumstance ≥ 90 cm in men and ≥ 85 cm in women. Dietary habits were evaluated using dietary guidelines published by the Korean Ministry of Health and Welfare. Demographic and clinical characteristics along with dietary habits and information related to obesity were collected. Factors related to obesity were evaluated separately by sex. Results: Dietary habits differed according to sex, in that scores for healthy eating habits were lower in men than in women. In men, the prevalences of general and abdominal obesity were 17.0% and 37.3%, respectively. In women, the prevalences of general and abdominal obesity were 23.1% and 38.5%, respectively. Regression analysis showed that the scores of regular eating habits were negatively associated with general and abdominal obesity in men, and the scores of healthy eating habits were negatively associated with general and abdominal obesity in women. Conclusion: Among patients with schizophrenia, regular eating habits might reduce the risk of obesity in men, and healthy eating habits might reduce the risk of obesity in women. Nutrition education should be provided to community- dwelling patients with schizophrenia to prevent obesity in this population.

Cooperative combination of LIBS-based elemental analysis and near-infrared molecular fingerprinting for enhanced discrimination of geographical origin of soybean paste.

Laser-induced breakdown spectroscopy (LIBS) and near-infrared (NIR) spectroscopy were combined to enhance discrimination of soybean paste samples according to geographical origin. Since element and organic component compositions of soybean pastes depend on soybean cultivation areas and fermentation conditions, utilization of two complementary spectroscopic signatures would be synergetic for the discrimination. When the areas of C (AC) and Ca (ACa) peaks in the LIBS spectra were used as the inputs for linear discriminant analysis, the accuracy was 95.4%. The accuracy became 92.1%, when the principal component (PC) scores obtained by principal component analysis of the NIR spectra were employed. To enhance NIR discrimination, two-trace two-dimensional (2T2D) correlation analysis was adopted to recognize minute spectral differences. With using the 1st/2nd PC scores of 2T2D slice spectra, accuracy increased to 95.0%. When the ratios of ACa/AC and the 2nd PC scores of the samples were combined together, the accuracy improved to 99.6%.