[Attempt to Calculate the Efficiency of Methylation Using 1H-NMR for Analyzing Brominated Vegetable Oil].

We studied the efficiency of methylation for analyzing brominated vegetable oil (BVO). In this report, we investigated whether 1H-NMR is an applicable method for assessing the efficiency of methylation to analyze BVO. 1H-NMR sufficiently calculated the efficiency of methylation using each integral and the numbers of protons derived from the methyl group, which is characteristic in products, and the methine group, which is characteristic in unreacted substances. Additionally, the efficiency of methylation calculated via 1H-NMR was in good agreement with changes in the peak area of BVO fatty acid methyl esters (BVOFAMEs) after various heating times obtained from GC-FID analysis. Therefore, 1H-NMR is applicable for calculating the efficiency of methylation to analyze BVO.

Epidemiology of Syphilis in Tokyo from 2019 to 2022: a Descriptive Epidemiological Study.

In recent years, the incidence of syphilis in Tokyo has increased. This descriptive epidemiological study aimed to elucidate the status of syphilis within the city. Data regarding age, sex, disease stage, and presumed sexual partners of patients with syphilis reported in Tokyo were compiled and analyzed. A total of 9,419 patients with syphilis were diagnosed between 2019 and 2022. A sharp rise was observed in the number of reported cases from 2021 to 2022. Between 2020 and 2022, the number of women in their 20s who developed syphilis rapidly increased by more than 3-fold. Furthermore, the number of pregnant women with syphilis increased the end of 2022. Despite a rapid increase in the number of young women with syphilis, the incidence of congenital syphilis has remained stable. This stability may be attributed to the early detection of syphilis during pregnancy, facilitated by the high rate of antenatal checkups in Tokyo. However, the growing incidence of syphilis among young women could potentially lead to a rise congenital syphilis cases in the future. Therefore, public health strategies should include educational initiatives targeting high-risk populations and adolescents, along with early and appropriate testing and treatment to prevent the progression of syphilis.

Transmission of COVID-19 in Nightlife, Household, and Health Care Settings in Tokyo, Japan, in 2020.

Importance: There have been few studies on the heterogeneous interconnection of COVID-19 outbreaks occurring in different social settings using robust, surveillance epidemiological data. Objectives: To describe the characteristics of COVID-19 transmission within different social settings and to evaluate settings associated with onward transmission to other settings. Design, Setting, and Participants: This is a case series study of laboratory-confirmed COVID-19 cases in Tokyo between January 23 and December 5, 2020, when vaccination was not yet implemented. Using epidemiological investigation data collected by public health centers, epidemiological links were identified and classified into 7 transmission settings: imported, nightlife, dining, workplace, household, health care, and other. Main Outcomes and Measures: The number of cases per setting and the likelihood of generating onward transmissions were compared between different transmission settings. Results: Of the 44 054 confirmed COVID-19 cases in this study, 25 241 (57.3%) were among male patients, and the median (IQR) age of patients was 36 (26-52) years. Transmission settings were identified in 13 122 cases, including 6768 household, 2733 health care, and 1174 nightlife cases. More than 6600 transmission settings were detected, and nightlife (72 of 380 [18.9%]; P < .001) and health care (119 [36.2%]; P < .001) settings were more likely to involve 5 or more cases than dining, workplace, household, and other settings. Nightlife cases appeared in the earlier phase of the epidemic, while household and health care cases appeared later. After adjustment for transmission setting, sex, age group, presence of symptoms, and wave, household and health care cases were less likely to generate onward transmission compared with nightlife cases (household: adjusted odds ratio, 0.03; 95% CI, 0.02-0.05; health care: adjusted odds ratio, 0.57; 95% CI, 0.41-0.79). Household settings were associated with intergenerational transmission, while nonhousehold settings mainly comprised transmission between the same age group. Among 30 932 cases without identified transmission settings, cases with a history of visiting nightlife establishments were more likely to generate onward transmission to nonhousehold settings (adjusted odds ratio, 5.30 [95% CI, 4.64-6.05]; P < .001) than those without such history. Conclusions and Relevance: In this case series study, COVID-19 cases identified in nightlife settings were associated with a higher likelihood of spreading COVID-19 than household and health care cases. Surveillance and interventions targeting nightlife settings should be prioritized to disrupt COVID-19 transmission, especially in the early stage of an epidemic.

Analyses of the brominated vegetable oil in soft drinks using gas chromatography-flame ionization detector and atmospheric pressure gas chromatography-quadrupole/time-of-flight mass spectrometry.

Herein, a new method for quantifying the brominated vegetable oil content in commercial soft drinks was developed, which accelerated the sample preparation process and improved analytical efficiency. First, simple and accurate chromatographic separation techniques were performed using a VF-5ht column for both GC-FID (quantitative) and APGC-QTOF (qualitative) analyses. The samples were subjected to chromatography on a reversed-phase solid-phase extraction cartridge. (PoraPak™RxnRP). Transesterification using a boron trifluoride methanol complex in methanol solution was performed. When validating this method, the analyte recovery percentages were between 82.2% and 99.9%, and the recovery and standard deviation of repeatability values were between 1.2% and 3.5%. Using an isotope library, the bromostearic acid methyl esters (9,10-dibromostearic acid methyl ester, 9,10,12,13-tetrabromostearic acid methyl ester, and hexabromostearic acid methyl ester) in the sample mixtures were qualitatively confirmed via APGC-QTOF. A novel aqueous ammonium adduct, which has not been previously reported, was also confirmed. These results indicated that this new method was simple, accurate, and also allowed for precise qualitative and quantitative confirmation as well as high reproducibility.

Structures of Two Yellow Dyes Found in Cucumbers Pickled in Soy Sauce Colored with Tartrazine (Y4).

Two yellow dyes, together with tartrazine (Y4), were found in cucumbers pickled in soy sauce, for which the use of tartrazine is permitted, by TLC, LC-DAD, and LC-MS. The retention times on LC chromatograms and the maximum absorbance wavelengths measured by LC-DAD of the two dyes were different from those of tartrazine. Mass spectra of the dyes indicated that these dyes lacked one sulfonyl group of tartrazine. The presence of two less sulfonated dyes in tartrazine has been reported. Hence, the two less sulfonated dyes were synthesized. The two dyes found in cucumbers were compared with the synthesized dyes by LC-DAD and LC-MS. Since the retention times of the dyes in cucumbers on the LC chromatograms, as well as their LC-DAD spectra and mass spectra, were found to be identical with those of the synthesized dyes, we concluded these dyes are the less sulfonated subsidiary dyes of tartrazine.