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To identify effective light spectra for increasing the productivity of Panax ginseng, we conducted experiments in a controlled environment using a hydroponic cultivation system in a plant factory. We investigated the effect of single LEDs (red, blue, and yellow) and mixed LEDs (red + blue and red + blue + white). The relationships between four light spectra (red, blue, yellow, and white) and physiological responses (net photosynthetic rate, stomata conductance, transpiration rate, and intercellular CO2 partial pressure), as well as growth responses (shoot and root biomass), were analyzed using multivariate statistical analysis. Among the four physiological response variables, shoot biomass was not increased by any pathway, and root biomass was increased only by the intercellular CO2 partial pressure. Red and yellow light increased shoot biomass, whereas white light promoted an increase in the net photosynthetic rate and enhanced root biomass. In contrast, blue light was less effective than the other light spectra in increasing both shoot and root biomass. Therefore, red and yellow light are the most effective light spectra for increasing shoot biomass and white light is effective for increasing root biomass in a plant factory that uses artificial LED lighting. Furthermore, the intercellular CO2 partial pressure is an important physiological variable for increasing the root biomass of P. ginseng.

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BACKGROUND: With the rapid spread of COVID-19, the makeup trend in the cosmetics market is changing as mask-wearing has become a common practice. This study was conducted to establish an objective and reliable method for analyzing the transfer of colored cosmetics onto face masks. METHODS: A total of 24 women participated in this test. The participants were requested to wear Korean Filter 94 masks after having applied colored cosmetics on their faces and lips. VISIA-CR was used to photograph the face, and a camera was used to photograph the mask, which had smeared the cosmetics. Each image was analyzed using the Image-pro® 10 image analysis software. RESULTS: Immediately after applying the cosmetics, the intensity of the face decreased and the redness of the lips increased when compared with the results 30 minutes after washing the face. After wearing a mask, the intensity increased and the redness decreased when compared with immediately after applying the cosmetics. The area before and after the colored cosmetics smeared onto the mask was increased. CONCLUSION: It is expected that this study could be used as a reference for further experiments on analysis of methods for preventing mask stains.

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BACKGROUND: The spread of COVID-19 has made mask wear essential. Expecting that long-term mask wear would change the characteristics of skin, this study investigated changes in skin wrinkles and pores caused by long-term mask wear and whether or not use of moisturizers has an effect on any changes. MATERIALS AND METHODS: The study participants were 20 women who were instructed to wear a mask for at least 6 hours a day for 4 weeks. Measurements of skin wrinkles and pores were obtained before and after the 4 weeks of mask wear. The effects of application of a moisturizer were assessed by applying moisturizer within the mask-wearing area. They completed a questionnaire about skin changes at the end of the study period. RESULTS: After wearing the mask for 4 weeks, there was a significant increase in the skin wrinkles and pores; both variables decreased significantly in skin areas where a moisturizer had been applied. The results of the questionnaire-based survey indicated the study participants considered that long-term wearing of a mask had affected their skin. CONCLUSION: Wearing a mask for extended periods increases skin wrinkles and pores and using a moisturizer when wearing the mask helps to reduce this problem.

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This study evaluated hair samples from 28 subjects who tested positive for ketamine at Seoul Institute National Forensic Service in Korea between 2016 and 2017. Ketamine in the hair was extracted using a solution of 1% hydrochloric acid in methanol for 16 h. Extracts were analyzed using gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-tandem mass spectrometry (LC-MS-MS). The LC-MS-MS method was validated by determining the limit of detection (LOD), limit of quantification (LOQ), linearity, intra- and inter-accuracy, precision and matrix effect. In 59 ketamine-positive hair or hair segments from 28 ketamine abusers, the ketamine concentration was found to be in the range of 0.011-335.8 ng/mg (mean, 13.6; median, 1.8), and the norketamine concentration was found to be in the range of 0.001-35.7 ng/mg (mean, 7.5; median, 0.44). The ratio of norketamine to ketamine concentrations in hair was in the range of 0.01-1.46 (mean, 0.34; median, 0.26). The distribution of ketamine concentration in hair samples was as follows: 0.01-0.1 ng/mg in 11 samples (18.6%), 0.1-5 ng/mg in 33 samples (55.9%), 5-10 ng/mg in 4 samples (6.8%), 10-15 ng/mg in 2 samples (3.4%), 15-20 ng/mg in 4 samples (6.8%), 40-45 ng/mg in 2 samples (3.4%), 45-50 ng/mg in 1 sample (1.7%) and >100 ng/mg in only 2 samples (3.4%). In the hair of ketamine abusers, 26 of 28 subjects were detected simultaneously ketamine with other drugs, including methylenedioxymethamphetamine (MDMA; n = 9), methamphetamine (MA; n = 3), MDMA/MA (n = 3), MDMA/para-methoxyamphetamine (PMA; n = 3), MDMA/PMA/MA (n = 2), cocaine (n = 1) and other drugs (n = 5, propofol, zolpidem or benzodiazepines). Along with ketamine, other controlled drugs were detected in most of the hair samples: MDMA (60.7%), MA (28.6%), PMA (17.9%), zolpidem (17.9%) and propofol (14.3%) in the frequency of abuse. In conclusion, most of the ketamine abusers (92.9%) were polydrug abusers, who were concomitantly abusing other controlled substances.

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Cyclopropylfentanyl has been encountered by law enforcement and public health officials beginning in mid-2017 and has been associated with numerous overdoses and fatalities. The detection and identification of cyclopropylfentanyl has become more challenging with the subsequent emergence of multiple structural isomeric fentanyl species, some of which have been detected in seized drug casework. These include crotonylfentanyl, methacrylfentanyl, para-methylacrylfentanyl, and ortho-methylacrylfentanyl; all of which have the same exact mass and similar fragmentation patterns. Since these compounds may be scheduled differently and pharmacologically act differently, it is important to be able to differentiate them analytically. Our method was developed and validated for the analysis and differentiation of cyclopropylfentanyl from its isomers by liquid chromatography tandem mass spectrometry (LC-MS/MS), in order to confirm the identify of cyclopropylfentanyl in biological specimens from death investigation casework; 36 postmortem blood samples were submitted for analysis. Cyclopropylfentanyl, crotonylfentanyl, methacrylfentanyl, and para-methylacrylfentanyl were successfully resolved using a 13-minute run time and a simple gradient elution. Ortho-methacrylfentanyl was resolved only in a 20-minute chromatographic run. The assay met validation performance characteristics, with an analytical range of 1-100 ng/mL and limits of detection of 0.1 ng/mL for all analytes. Analysis of commonly encountered substances showed no interferences. All samples previously reported positive for cyclopropylfentanyl were confirmed positive for cyclopropylfentanyl in the absence of its isomers. To our knowledge to date, no positive toxicological specimens have been encountered for any cyclopropylfentanyl isomers.

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A growing body of evidence points to the useful roles of computational approaches in the structural characterization of natural products. Rhododendron brachycarpum has been traditionally used for the control of diabetes, hepatitis, hypertension, and rheumatoid arthritis and classified as an endangered species in Korea. A grayanotox-9(11)-ene derivative along with five known diterpenoids, were isolated from the MeOH extract of R. brachycarpum. Extensive 1D and 2D NMR experiments were conducted to establish the 2D structure and relative configuration of the grayanotox-9(11)-ene derivative. Comparison of simulated and experimental ECD spectra resulted in an inconclusive outcome to assign its absolute configuration. Alternatively, gauge-including atomic orbitals (GIAO) NMR chemical shift calculations, with support by the advanced statistical method DP4 plus, and acid hydrolysis were employed to establish its absolute configuration. This work exemplifies how NMR analysis, combined with quantum mechanics calculations, is a viable approach to accomplish structural assignment of minor abundance molecules in lieu of X-ray crystallography or chiroptical approaches.

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Since driving under the influence of drugs (DUID) is as dangerous as drink-driving, many countries regulate DUID by law. However, laws against the use of drugs while driving are not yet established in Korea. In order to investigate the type and frequency of drugs used by drivers in Korea, we analyzed controlled and non-controlled drugs in alcohol-positive blood samples. Total 275 blood samples were taken from Korean drivers, which were positive in roadside alcohol testing. The following analyses were performed: blood alcohol concentrations by GC; screening for controlled drugs by immunoassay and confirmation for positive samples by GC-MS. For the detection of DUID related drugs in blood samples, a total of 49 drugs were selected and were examined by GC-MS. For a rapid detection of these drugs, an automated identification software called "DrugMan" was used. Concentrations of alcohol in 275 blood samples ranged from 0.011 to 0.249% (average 0.119%). Six specimens showed positive results by immunoassay: one methamphetamine and five benzodiazepines I. By GC-MS confirmation, only benzodiazepines in four cases were identified, while methamphetamine and benzodiazepine in two cases were not detected from the presumptive positive blood samples. Using DrugMan, four drugs were detected; chlorpheniramine (5)*, diazepam (4), dextromethorphan (1) and doxylamine (1). In addition, ibuprofen (1), lidocaine (1) and topiramate (1) were also detected as general drugs in blood samples ('*' indicates frequency). The frequency of drug abuse by Korean drivers was relatively low and a total 14 cases were positive in 275 blood samples with a ratio of 5%. However it is necessary to analyze more samples including alcohol negative blood, and to expand the range of drug lists to get the detailed information.

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A liquid chromatography/tandem mass spectrometry method with solid phase extraction for the detection and the quantitation of flufenoxuron in an aliquot of blood was developed and validated. Flufenoxuron belongs to a benzoylurea insecticide and is the active ingredient of Cascade™. The analyte in postmortem specimens was extracted by solid-phase extraction with Bond Elut Certify cartridge. After the elution layer was evaporated, the residue was reconstituted with 70% methanol for LC/MS/MS analysis. Separations were carried out on a Synergi(®) 2.5u Fusion-RP 100 A column with column temperature kept at 40 °C at a flow rate of 0.4 mL/min. The mobile phase was composed of 5mM ammonium formate in 10% methanol and 5 mM ammonium formate in 90% methanol using gradient elution. A triple quadruple mass spectrometer equipped with an electrospray ionization source operated in a positive ion mode with selective reaction monitoring mode. Atrazine-d5 was used as internal standard. The assay was linear over 0.02-1.0 mg/L (r(2)=0.999). Limit of detection (LOD) and limit of quantitation (LOQ) in blood were 0.009 mg/L (S/N=3) and 0.02 mg/L (S/N=10), respectively. The accuracy and the precision were <14.9% of bias% and <8.1% of CV%, which are acceptable criteria according to toxicology laboratory guidelines. Relative recoveries with 0.02, 0.1 and 1.0mg/L (in blood) were 112.3%, 101.2% and 111.0% (n=5), respectively. The developed method was applied in forensic toxicology to determine flufenoxuron in postmortem specimens in a fatal case of flufenoxuron intoxication in a 48-year-old-man who was found dead on bed in a small room after vomiting on the floor. The postmortem heart blood, peripheral blood and gastric contents were analyzed for flufenoxuron with the result of 6.3 mg/L in heart blood, 3.2 mg/L in peripheral blood and 30.6 mg/kg in gastric contents, respectively. The concentration ratio of the heart/peripheral blood of flufenoxuron was 2.0, and the ratio of gastric contents/peripheral blood was 9.4, suggesting possible postmortem redistribution and there may be a massive amount of flufenoxuron orally ingested. This case study is the first report of lethal concentrations of flufenoxuron in postmortem specimens.

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Methamphetamine (MA) is the most commonly abused drug in Korea, followed by cannabis. Traditionally, MA analysis is carried out on both urine and hair samples and cannabis analysis in urine samples only. Despite the fact that oral fluid has become increasingly popular as an alternative specimen in the field of driving under the influence of drugs (DUID) and work place drug testing, its application has not been expanded to drug analysis in Korea. Oral fluid is easy to collect and handle and can provide an indication of recent drug abuse. In this study, we present an analytical method using GC-MS to determine tetrahydrocannabinol (THC) and its main metabolite 11-nor-delta9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) in oral fluid. The validated method was applied to oral fluid samples collected from drug abuse suspects and the results were compared with those in urine. The stability of THC and THC-COOH in oral fluid stored in different containers was also investigated. Oral fluid specimens from 12 drug abuse suspects, submitted by the police, were collected by direct expectoration. The samples were screened with microplate ELISA. For confirmation they were extracted using automated SPE with mixed-mode cation exchange cartridge, derivatized and analyzed by GC-MS using selective ion monitoring (SIM). The concentrations ofTHC and THC-COOH in oral fluid showed a large variation and the results from oral fluid and urine samples from cannabis abusers did not show any correlation. Thus, detailed information about time interval between drug use and sample collection is needed to interpret the oral fluid results properly. In addition, further investigation about the detection time window ofTHC and THC-COOH in oral fluid is required to substitute oral fluid for urine in drug testing.

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Ketamine (KT) is widely abused for hallucination and also misused as a "date-rape" drug in recent years. An analytical method using positive ion chemical ionization-gas chromatography-mass spectrometry (PCI-GC-MS) with an automatic solid-phase extraction (SPE) apparatus was studied for the determination of KT and its major metabolite, norketamine (NK), in urine. Six ketamine suspected urine samples were provided by the police. For the research of KT metabolism, KT was administered to SD rats by i.p. at a single dose of 5, 10 and 20mg/kg, respectively, and urine samples were collected 24, 48 and 72 h after administration. For the detection of KT and NK, urine samples were extracted on an automatic SPE apparatus (RapidTrace, Zymark) with mixed mode type cartridge, Drug-Clean (200 mg, Alltech). The identification of KT and NK was by PCI-GC-MS. m/z238 (M+1), 220 for KT, m/z 224 (M+1), 207 for NK and m/z307 (M+1) for Cocaine-D(3) as internal standard were extracted from the full-scan mass spectrum and the underlined ions were used for quantitation. Extracted calibration curves were linear from 50 to 1000 ng/mL for KT and NK with correlation coefficients exceeding 0.99. The limit of detection (LOD) was 25 ng/mL for KT and NK. The limit of quantitation (LOQ) was 50 ng/mL for KT and NK. The recoveries of KT and NK at three different concentrations (86, 430 and 860 ng/mL) were 53.1 to 79.7% and 45.7 to 83.0%, respectively. The intra- and inter-day run precisions (CV) for KT and NK were less than 15.0%, and the accuracies (bias) for KT and NK were also less than 15% at the three different concentration levels (86, 430 and 860 ng/mL). The analytical method was also applied to real six KT suspected urine specimens and KT administered rat urines, and the concentrations of KT and NK were determined. Dehydronorketamine (DHNK) was also confirmed in these urine samples, however the concentration of DHNK was not calculated. SPE is simple, and needs less organic solvent than liquid-liquid extraction (LLE), and PCI-GC-MS can offer both qualitative and quantitative information for urinalysis of KT in forensic analysis.

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The object of this study was to validate the Immunalysis Methamphetamine Microplate ELISA for detecting methamphetamine in hair. Twenty-nine scalp hair samples were obtained as routine cases submitted to the National Institute of Scientific Investigation in Seoul by the police. The hair samples were washed with 0.1% sodium dodecyl sulfate, distilled water, and dichloromethane. The samples were screened using the Immunalysis Methamphetamine Microplate ELISA and confirmed using gas chromatography-mass spectrometry (GC-MS). Twenty-eight hair samples were screened and confirmed as positive for methamphetamine. For ELISA analysis, the samples were extracted by incubation in monobasic phosphate buffer for 1 h at 60 degrees C. For GC-MS, the samples were extracted for 20 h in methanol containing 1% hydrochloric acid. The methanol/acid solution was evaporated to dryness and the resulting residue was derivatized with trifluoroacetic anhydride. Methamphetamine and amphetamine were detected using selective ion monitoring (SIM) mode. The Immunalysis Methamphetamine Microplate ELISA demonstrated a sensitivity and specificity of 97% and 100%, respectively, using a cut-off concentration of 0.5 ng/mg d-methamphetamine. The ELISA kit showed 63% cross-reactivity with d,l-methamphetamine and did not cross-react to any significant extent with the licit l-methamphetamine isomer. The intra- and interassay precisions were 2.5% and 3.7%, respectively.

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Dextromethorphan (DMP), an antitussive, is one of the most popular drugs among the younger generation in Korea. It usually is taken for its hallucinogenic properties and overdoses have been responsible for the fatalities that have been reported frequently. To control the abuse of DMP, the authorities restricted its use through classifying it as a controlled drug on October 2003. The purpose of this study is to provide a standard method for the analysis of DMP and its main metabolite, dextrorphan (DTP) in biological specimens. At first we established a standard operating procedure (SOP) for DMP/DTP in urine, and a method validation was performed. We also quantified DMP from 16 drug abuser's urine samples all of which were positive in the screening test for DMP. For the detection of DMP/DTP, urine samples were adjusted with 6N NaOH (pH 11) and extracted with ethylacetate. Thin layer chromatography was used as the screening test, and the final identification for DMP/DTP was used by GC/MS. The ions (m/z 271 for DMP, m/z 257 for DTP and m/z 86 for lidocaine as internal standard) were extracted from the full scan mass spectrum and were used for quantification. The selectivity, linearity of calibration, accuracy, within- and between day precision, limit of detection and quantification, recovery and stability were examined as parts of the method validation. Extracted calibration curves were linear from 100 to 2000 ng/mL for DMP and DTP with correlation coefficients better than 0.999. Limit detection was 50 ng/mL for DMP and DTP. Within-run precision (%CV) for DMP and DTP at three different concentrations (100, 500 and 1000 ng/mL) was 6.10-18.85%, and between-run precision was 1.70-7.86% for DMP and DTP. Absolute recovery for DMP and DTP was 57-74%, and relative recovery (extraction efficiency) was 80-89%. For 16 drug abuser's urine samples, the concentrations of DMP and DTP were 0.16-52.63 and 0.41-23.75 microg/mL, respectively. Method validation is an important requirement in the practice of chemical analysis, and it will be particularly useful in verifying the reliability of analytical results in the field of forensic science.

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