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The mi-iuy croaker Miichthys miiuy has immense commercial value in the Republic of Korea. The red drum Sciaenops ocellatus is widely produced by aquaculture, although its price is approximately 25% that of M. miiuy. S. ocellatus has black spots on its tail, enabling it to be distinguished from M. miiuy based on appearance. However, identifying S. ocellatus after simple processing steps, such as skin removal and dicing, is difficult. Certain traders misrepresent and sell S. ocellatus as M. miiuy or cultured M. miiuy for illegal economical gain. Therefore, an accurate and rapid identification method is required to distinguish between M. miiuy and S. ocellatus in the field. Here, a method for rapid field identification was developed based on species-specific primers using a portable ultra-fast PCR instrument. The ultra-fast real-time PCR method can complete the entire analytical procedure, including DNA isolation, amplification, and detection, within 30 min, thus maintaining the accuracy of identifying M. miiuy and S. ocellatus products on site. Forty-nine commercial products were tested, and all samples were successfully identified. Thus, the developed method is rapid, efficient tool for ensuring consumer protection.

Radio-over-fiber (RoF)-based front haul architecture has attracted considerable attention for fifth-generation (5G) cellular systems because of its cost effectiveness, however, it is susceptible to harmonic frequency distortion and intermodulation products (IMs) arising from the nonlinearity of the laser diode. To overcome this limitation, an asymmetric electrical predistortion method, using a single Schottky diode with nonlinear characteristics similar to those of a laser diode, was previously proposed. However, its asymmetric structure causes a phase mismatch, which limits the system bandwidth. In this study, we propose an enhanced electrical predistortion technique using dual-parallel Schottky diode blocks. The proposed technique was validated by experiments involving an IM3 drop of approximately 27 dB, and by using identical dual Schottky diode blocks, the phase mismatch in the previously proposed method is completely eliminated. Thus, the applicable bandwidth is extended to 1.8 GHz. This technique can be used to improve the linearity and increase the bandwidth of RoF systems. Additionally, the simple structure is attractive for low-power applications.

In this study, we developed a saccharin (SAC)‐based radiopharmaceutical (68Ga‐NOTA‐SAC) and evaluated the possibility of its application as a PET tracer in the diagnosis of carbonic anhydrase IX (CA IX)‐overexpressed tumors. We did a water‐soluble tetrazolium assay and flow cytometry analysis to identify the cell viability decrease by SAC. The radiochemical purity and stability of 68Ga‐ NOTA‐SAC in human and mouse serum was greater than 98%. The small animal PET image‐based radioactivity distribution of all organs decreased over time.68Ga‐NOTA‐SAC presented the highest tumor‐to‐muscle ratio at 90 min post injection (p.i). The growth rates of tumor‐to‐muscle ratios of 68Ga‐NOTA‐SAC were 88% at 60 min and 220% at 90 min, compared to 30 min p.i. The potential of 68Ga‐NOTA‐SAC as a PET tracer is expected to contribute to the diagnostic research on CA IX‐overexpressed tumors with the advantages of a relatively simple synthesis method., We developed a new 68Ga‐NOTA‐SAC as a saccharin‐based PET tracer for diagnosis of CA IX‐overexpressed tumors and quantitatively assessed the targeting ability of 68Ga‐NOTA‐SAC using micro‐PET imaging with in vitro experiments. These 68Ga‐NOTA‐SACs demonstrated a high uptake ratio of the tumor region as well as rapid excretion, allowing a high‐contrast PET image of the targeted tumor region.

In this work, we developed an analytical method for determining 11 illicit compounds in dietary supplements using high-performance liquid chromatography and liquid chromatography-tandem mass spectrometry. Eleven target compounds, including those meant for weight loss (7-keto-dihydroepiandrosterone, buformin, metformin, phenformin, salbutamol, and tolbutamide), sexual enhancement (dihydroepiandrosterone), and relaxation (asarone, kavain, magnoflorine, and picamilon) were screened and confirmed in dietary supplements. Method validation was performed by evaluating the selectivity, linearity, limit of quantification (LOQ), accuracy, and precision according to the Association of Official Analytical Chemists guidelines. The linearity was > 0.993 for all analytes. The LOQs were ranged in 2.1-9.9 μg/mL (HPLC-DAD) and 0.002-0.008 μg/mL (LC-MS/MS). The accuracies (expressed as recovery) were 90.0-106% (HPLC-DAD) and 83.0-114% (LC-MS/MS). The precision (expressed as the relative standard deviation) was below 10% using HPLC and LC-MS/MS. The proposed method can be used for the surveillance of illicit compounds in dietary supplements.

This paper shows the possibility of using steam pretreatment to improve the efficiency of membrane recovery chemical cleaning. Before applying chemicals to clean a fouled membrane, steam pretreatment was employed to loosen the structure of the foulant layer and weaken the attachment of those foulants on the membrane. Although longer steam contact times would lead to even better cleaning efficiency, the steam pretreatment duration was limited to less than 2 min to maintain membrane integrity. When cleaning fouled membranes with 1 mol/L HCl, the cleaning efficiency without steam pretreatment went from 83.3 to 90.2% as cleaning time increased from 30 to 180 min. As for 90-s steam pretreatment, the cleaning efficiency showed high values of more than 93% regardless of cleaning time. When the concentration of HCl was decreased to 0.2 mol/L, the cleaning efficiencies with a 90-s steam pretreatment was 78.6% and 92.6% for relatively short cleaning times of 30 and 60 min, respectively; this is much higher than the 62.2% and 76.7% achieved when cleaning without steam pretreatment. In addition, when using alkaline solution as the cleaning chemical, similar results were obtained. This implies that the application of steam before chemical cleaning is effective in improving cleaning efficiency, and so, this technique has the potential to reduce the amount of cleaning chemical required for membrane recovery cleaning.

This is a revised version of my paper presented in a special session on reduplication at the Fall Conference of Language Research Institute, Hankuk University of Foreign Studies (Nov. 1, 2019).

Mineral oil hydrocarbons (MOH) are widely used in the food industry for applications such as printing inks, additives, adhesives, and processing aids for food additives. Recently, the migration of MOH from food contact paper and board into foods has raised public health concerns. In this study, a total of 110 food contact paper and board samples, including baking and cooking paper (23), baking cups (28), food packaging bags (22), lunch boxes (8), party plates (26), and straws (3) were evaluated to quantify the content and short-term migration levels of MOH. The MOH were separated into mineral oil saturated hydrocarbons (MOSH)/polyolefin oligomeric saturated hydrocarbons (POSH) and mineral oil aromatic hydrocarbons (MOAH) via a validated on-line liquid chromatography-gas chromatography-flame ionisation detection (LC-GC-FID) technique. The coating materials of the sample products comprised polyethylene, polypropylene, polyethylene terephthalate, and silicone. The effects of the coating materials on the content and migration of MOH/POSH were evaluated. Quantitative analysis of the MOH in the samples showed that the MOSH/POSH and MOAH content varied widely, ranging from 16 to 5626 mg kg

Quaternary ammonium compounds (QACs) are widely used in consumer products because of their unique antibacterial properties, and dishwashing detergents are a major source of exposure through oral, inhalation, and dermal routes. The three classes of QACs, including benzalkonium chloride (BAC), n-alkyldimethylethylbenzylammonium chloride (ADEBAC), and di-n-alkyldimethylammonium chloride (DDAC), in spray and non-spray types of dishwashing detergents were quantified by high-performance liquid chromatography-mass spectrometry. A tiered risk assessment approach was also considered. In the Tier 1 assessment, the mean and worst-case exposure were estimated to screen for rough exposure and risk levels. In the Tier 2 assessment, mean and upper-tail exposure levels were calculated based on the exposure parameters of Korean consumers using Monte Carlo simulation. QACs had a low frequency of detection of up to 20% in dishwashing detergents, and the contents of detected QACs varied depending on the individual samples. Based on the results of the Tier 1 assessment, BACs and DDACs posed potential health risks via inhalation and dermal routes. Tier 2 assessment suggested that the current level of oral and dermal exposure of Korean consumers to QACs in dishwashing detergents is unlikely to pose a health risk, even for upper-tail exposure groups. However, the present results suggest that spray-type DDACs may pose a health risk in the upper-tail inhalation exposure group, and further investigation is required to clarify this risk.

Condensed phosphates are deliberately added to the fishery and processed marine food products on purpose to increase the weight of products. However, excessive intake overwhelming bodily homoeostasis can result in phosphate toxicity such as mineral and bone disorders, associated with chronic kidney diseases, and cardiovascular events. Rapid analysis for condensed phosphates is required to detect the illegal adulteration of processed marine products. We optimised an analytical method using ion chromatography for the rapid and selective detection of condensed phosphates in various kinds of fishery and processed marine products. We compared the performance of three columns (IonPac AS11, AS11-HC, and AS16) for the detection of condensed phosphates with respect to time of analysis and sensitivity. The IonPac AS11 column exhibited the shortest retention time for the major condensed phosphates (pyro-, tri-, and trimetaphosphate), the highest sensitivity for trimetaphosphate, and good repeatability and precision. Microwave and boiling processing were examined as methods to prevent hydrolysis of condensed phosphates into orthophosphate, which is critical in distinguishing intentionally added condensed phosphates from naturally occurring orthophosphate. Microwave treatment was determined to be the more effective method to suppress hydrolysis of condensed phosphates to orthophosphate. Furthermore, microwave processing could be used for thawing the frozen samples, saving extra effort and time. We confirmed that the method exhibits good recovery (80% or more) and precision (%RSD < 10%) for samples with various matrices. With the method, 14 kinds of fishery and processed marine food products were successfully analysed for condensed phosphates. Especially, we identified that phosphate levels in the processed shrimp and dried shredded squid samples exceeded the maximum allowable levels specified in the CODEX standard. We believe that our method would be useful for the rapid analysis of condensed phosphates in various types of fishery and processed marine food products.

We developed and presented highly sensitive solvent-free silver nanoparticle strain sensors fabricated using the aerodynamically focused nanoparticle (AFN) printer. The nanoparticles were printed in various conductive patterns. We explored how printer scan velocity affected pattern geometry and sensor sensitivity. The strain sensors were highly sensitive; the scan velocity afforded tunable sensitivity; and an analytical model predicted the behavior well under low-strain (

Flavoring agents are added to cigarettes to improve taste. There are mostly permitted food additives, but some of them are restricted for use in food, cosmetics, and toys, since they can cause allergic reactions. Previous studies have investigated the levels of flavoring agents in tobacco but none has focused on their content in filter tips and capsules. Moreover, no studies have assessed the risk of adding allergenic flavoring agents in cigarettes. Here, we developed and validated a simultaneous analysis method for 25 allergenic flavoring agents and menthol with gas chromatography–tandem mass spectrometry to determine levels of flavoring agents in the tobacco, filter tips, and capsules of 54 commercial cigarettes in Korea. All cigarettes contained at least one allergenic flavoring agent regardless of the inclusion of flavoring capsules. Importantly, the filter tips and the capsules contained higher levels of flavoring agents than tobacco, highlighting the importance of the quantification of flavoring agents in these parts of cigarettes. Nevertheless, the risk assessment based on their levels in cigarettes suggested that their exposure was maintained at a safe level. However, the risk assessed from maximum menthol, linalool, and cinnamaldehyde exceeded one-tenth of derived no-effect levels, suggesting the need for further studies on their risk to human health.

Condensed phosphates are used as food additives, especially in marine products and meat, to improve food quality. The import and consumption of fishery and processed marine food products in Republic of Korea have reportedly increased by ~5 per cent annually. However, processed marine food products are often intentionally adulterated with excessive amounts of condensed phosphates to increase their weight. Excessive intake of condensed phosphates via consuming processed marine food products can lead to various adverse effects on human health due to anionic imbalance. Herein, we conducted a safety assessment of condensed phosphates in 14 types of fishery and processed marine food products in Korea for the first time. Subgroup analysis of various factors including gender, age, and region was also performed, and the risk level of exposure for each group was estimated. Safety assessments by age and gender indicated that infants were at the highest risk. In the regional safety assessment, Chungnam, the most inland region, showed the lowest risk. For both the general and the high-intake groups (95th percentile) in all classifications, the risk was lower (

The mi-iuy croaker Miichthys miiuy has immense commercial value in the Republic of Korea. The red drum Sciaenops ocellatus is widely produced by aquaculture, although its price is approximately 25% that of M. miiuy. S. ocellatus has black spots on its tail, enabling it to be distinguished from M. miiuy based on appearance. However, identifying S. ocellatus after simple processing steps, such as skin removal and dicing, is difficult. Certain traders misrepresent and sell S. ocellatus as M. miiuy or cultured M. miiuy for illegal economical gain. Therefore, an accurate and rapid identification method is required to distinguish between M. miiuy and S. ocellatus in the field. Here, a method for rapid field identification was developed based on species-specific primers using a portable ultra-fast PCR instrument. The ultra-fast real-time PCR method can complete the entire analytical procedure, including DNA isolation, amplification, and detection, within 30 min, thus maintaining the accuracy of identifying M. miiuy and S. ocellatus products on site. Forty-nine commercial products were tested, and all samples were successfully identified. Thus, the developed method is rapid, efficient tool for ensuring consumer protection. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10068-021-00954-4.

In this work, liquid chromatography&ndash, tandem mass spectrometry (LC-MS/MS) method was developed and validated for screening and confirmation of 64 illicit compounds in dietary supplements. The target compounds were illegally used pharmaceutical drugs, prohibited compounds, and not authorized ingredients for different therapeutics (sexual enhancement, weight loss, muscular strengthening, and relaxing products). The validation procedure was performed to evaluate selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, and precision according to the Association of Official Analytical Chemists guidelines. The linearity was &gt, 0.98 in the range of 0.5&ndash, 200 &micro, g L&minus, 1. The LOQs were in the range 1&ndash, 10 &micro, g kg&minus, 1 for all target compounds. The accuracy (expressed as recovery) was 78.5&ndash, 114%. The precision (expressed as the relative standard deviation) was below 9.15%. The developed method was applied for the determination of illicit compounds in dietary supplements collected from websites. As a result, the total detection rate was 13.5% (27 samples detected in 200 samples). The concentrations of detected samples ranged from 0.51 to 226 mg g&minus, 1. The proposed methodology is suitable for monitoring the adulteration of illicit compounds in dietary supplements.

Proteolysis-targeting chimera (PROTAC)-mediated protein degradation is a rapidly emerging therapeutic intervention that induces the degradation of targeted proteins. Herein, we report the design and biological evaluation of a series of androgen receptor (AR) PROTAC degraders for the treatment of metastatic castration-resistant prostate cancer. Predominantly, instead of thalidomide, we utilized the TD-106 scaffold, a novel cereblon (CRBN) binder that was identified in our previous study. Our results suggest that the linker position in the TD-106 CRBN binder is critical for the efficiency of AR degradation. The compounds attached to the 6-position of TD-106 promoted better degradation of AR than those at the 5- and 7-positions. Among the synthesized AR PROTACs, the representative degrader 33c (TD-802) effectively induced AR protein degradation, with a degradation concentration 50% of 12.5 nM and a maximum degradation of 93% in LNCaP prostate cancer cells. Additionally, most AR PROTAC degraders, including TD-802, displayed good liver microsomal stability and in vivo pharmacokinetic properties. Finally, we showed that TD-802 effectively inhibited tumor growth in an in vivo xenograft study.

In wastewater treatment, filtration membranes that are used for extended periods of time must inevitably be cleaned with chemical agents that can influence the membrane properties. In addition, the use of secondary effluents in reclamation readily contaminates membranes with irreversible fouling. In this study, to investigate the phenomenon of fouling control by ex-situ CIP, different types of aeration (coarse bubble, microbubble) and various concentrations (100–3000 mg/L) of NaOCl were employed to fouled membranes by secondary effluents from wastewater treatment. The cleaning efficiencies of each cleaned membrane were evaluated after ex-situ CIP, and the selected membranes, including the fouled membrane before ex-situ CIP, were examined through comparative changes in the physicochemical properties. Microbubbles were more effective in retaining the membrane permeability in ex-situ CIP with a low concentration (100 and 500 mg/L) of NaOCl. Additionally, the ex-situ CIP with microbubbles showed the greatest cleaning efficiency at a cleaning time of more than 2 h.

Currently, capsule cigarettes have been introduced by tobacco industries and their sales have increased exponentially. However, the capsule flavoring ingredients and their safety are still unknown. Although the contents of menthol and other ingredients directly added to cigarettes have been determined extensively, no analogous study exists for menthol-containing cigarette capsules. Basic physical properties of capsules in all 31 different capsule cigarettes commercially available in Korea were investigated, and their menthol contents were determined in this study. Other ingredients in these capsules were also qualitatively analyzed; methyl octanoate, menthone and isopulegol as well as menthol were detected in all the capsules. There is considerable variability in basic physical properties and menthol contents of cigarette capsules depending on their brand styles. The menthol contents of capsules and whole cigarettes are similar or higher than those previously reported for conventional menthol cigarettes. This is the first report on the physical properties of capsules and the fact that a wide range of menthol contents in capsule cigarettes, regardless of flavor types, allows smokers to select menthol content to their liking.

Convenience foods are currently popular among busy, modern consumers. However, the migration of plastics additives and non-intentionally added substances (NIAS) from packaging materials has raised concern about the potential health risks. The migration of nine compounds, including additives (butylated hydroxytoluene and 2,2,4-trimethyl-1,3-pentanediol diisobutyrate), and NIAS that originated from additives degradation products (phenol, 2-ethyl-1-hexanol, acetophenone, 4-propylbenzaldehyde, 2,6-di-tert-butylbenzoquinone, 2,4-di-tert-butylphenol, and methyl-3-(3,5-ditertbutyl-4-hydroxyphenyl)) from convenience food packaging was evaluated in migration tests employing food simulants under real-life consumption and worst-case scenario conditions. Their migration level in the food simulants was quantified by gas chromatography-mass spectrometry. Most of the compounds had a low frequency of detection and the detected compounds varied depending on the individual samples, regardless of the packaging materials. The worst-case migration tests showed that repetitive microwave heating considerably accelerated the migration and degradation of the additives due to polymer swelling, although a single microwave heating had little effect on the migration. Risk assessment confirmed that the current level of exposure of Korean consumers to the substances from convenience food packaging is unlikely to pose a health risk, even in the worst-case scenario.

Nitrosamines can be produced during the manufacture of rubber-type products such as pacifiers or the nipples of baby bottles. Humans can be exposed to the nitrosamines in these products when they are eluted into saliva. In this study, we compared the efficiency of electron impact ionization (EI), atmospheric pressure chemical ionization (APCI), and electrospray ionization (ESI) methods for the analysis of nine nitrosamines eluted into artificial saliva. In addition, nine nitrosamines eluted from 54 rubber-type products (rubber, thermoplastic elastomer, thermoplastic polyurethane, and polyurethane) marketed in Korea were monitored. Finally, non-carcinogenic and carcinogenic risk assessments of oral exposure to nine nitrosamines were performed based on the monitoring results. EI-GC-MS/MS performed the best for the simultaneous analysis of these nine nitrosamines with respect to overall linearity, trace analysis limit of detection (less than 1 μg), recovery (average 108.66 ± 9.32%), and precision (less than 6%), compared with liquid chromatography-tandem mass spectrometry (LC-MS/MS) (APCI and ESI) methods. Using the EI-GC-MS/MS method, these nine nitrosamines eluted into artificial saliva from 54 rubber-type products were monitored. Based on the monitoring data, risk assessment was performed by calculating the margin of exposure (MOE) for the respective nitrosamines detected. As a result, these nitrosamines were confirmed to be safe with regard to both non-carcinogenic and carcinogenic risks.

Preservatives are essential additives in dishwashing detergents and wet wipes. Ensuring the safe use of preservatives in products is important for public health, as some preservatives are associated with health issues. In this study, the content of 12 preservatives in 105 dishwashing detergents and 105 wet wipes was determined, where these compounds are commonly found, among consumer products. A realistic exposure estimation was considered by using Korean consumer-specific exposure parameters for adults and babies. A probabilistic risk assessment was conducted by applying the Monte Carlo simulation method. Benzoic acid (41%) and cetylpyridinium chloride (30%) were the most commonly used preservatives in dishwashing detergents and wet wipes, respectively, although their content in different products (benzoic acid: 0.28-19.4 mg/g in dishwashing detergents; cetylpyridinium chloride: 0.003-0.64 mg/g in wet wipes) varied widely. The calculated median and upper-limit margin of safety (MOS) values related to systemic health effects and skin sensitization from exposure to preservatives largely exceeded the target MOS, which confirmed the safety of the products. Exposure to preservatives from wet wipes was several times higher in babies than in adults. Sensitivity analysis revealed that the amount of the product used, frequency of use, and weight fraction of the preservative were the major contributors to the exposure to preservatives from dishwashing detergents and wet wipes.

Ultraviolet (UV) sterilization of kitchenware is considered environmentally friendly and economical. However, there are many cases of extended UV irradiation, which raises concerns about the release of hazardous substances. Here, we investigated the migration of monomers, plastic additives, and non-intentionally added substances (NIAS) from food utensils made of melamine–formaldehyde resin into food simulants after UV irradiation for up to 7 d. The migration of monomers (melamine and formaldehyde) was analyzed using a high-performance liquid chromatograph with a diode array detector. When irradiated with a UV lamp for 7 d, the release of melamine from food utensils made of melamine–formaldehyde resins increased by up to 85-fold compared with that from the unexposed samples. Formaldehyde release increased up to 4-fold after UV exposure. UV exposure led to a sustained increase in melamine migration in a time-dependent manner. Formaldehyde release also increased on the first day, but plateaued after seven days of exposure. Safety assessment demonstrated that there is a low risk of melamine and formaldehyde exposure of up to 11.78% and 7.95%, respectively, compared with the tolerable daily intake. Non-target screening analysis of plastic additives and NIAS from melamine–formaldehyde resin and other synthetic resins was performed using high-performance liquid chromatography quadrupole time-of-flight mass spectrometry. Exposure of melamine–formaldehyde resin to UV for 7 d drastically increased the release of plastic additives and NIAS. In contrast, for other synthetic resins (polypropylene, polyamide, polyethylene, polyethylene terephthalate, and silicone), the peaks of these compounds disappeared or decreased after UV exposure, indicating that the melamine–formaldehyde resin is less resistant to UV degradation than other synthetic resins.

The problem of new psychoactive substances (NPS) is emerging globally. However, the immunotoxicity of synthetic cannabinoids is not evaluated extensively yet. The purpose of the present study was to investigate whether synthetic cannabinoids (JWH-210 and JWH-030) induce adverse effects on lymphoid organs, viability of splenocytes and thymocytes, and immune cell activator and cytokines in mice. JWH-210 (10 mg/kg, 3 days, i.p.) is more likely to have cytotoxicity and reduce lymphoid organ weight than JWH-030 of ICR mice in vivo. We also demonstrated that JWH-210 administration resulted in the decrease of expression levels of T-cell activator including Cd3e, Cd3g, Cd74p31, and Cd74p41, while JWH-030 increased Cd3g levels. In addition, JWH-210 reduced expression levels of cytokines, such as interleukin-3, interleukin-5, and interleukin-6. Furthermore, we demonstrated that a CB2 receptor antagonist, AM630 inhibited JWH-210-induced cytotoxicity, whereas a CB1 receptor antagonist, rimonabant did not in primary cultured splenocytes. These results suggest that JWH-210 has a cytotoxicity via CB2 receptor action and results in decrement of lymphoid organ weights, T-cell activator, and cytokine mRNA expression levels.