Decomposition of the Simulant 2-Chloroethyl Ethyl Sulfide Blister Agent under Ambient Conditions Using Metal-Organic Frameworks.

Metal organic frameworks (MOFs) have been suggested as promising materials for application in the degradation of chemical warfare agents, with the majority of studies to date focusing on nerve agents. One of the most prominent MOFs used in the detoxification of nerve agents is UiO-66, which is of interest as a future nerve agent decontaminant. However, blister agents, which constitute one of the most toxic and highly reactive categories of chemical agents, are yet to be examined as gas-phase decontamination targets using MOF structures. In this study, a novel type of UiO-66 with a smaller particle size, namely, UiO-66S, was used as a decontaminant for the blister agent simulant, 2-chloroethyl ethyl sulfide (2-CEES). The gas-phase chemical adsorption and decomposition of 2-CEES were demonstrated for the first time, with an estimated t1/2 of 1.34 h. This value is the highest reported value for an MOF in gas-phase reaction conditions. The obtained nontoxic degradation products were identified, and the reaction mechanism was studied using density functional theory calculations. Furthermore, the synthesized UiO-66S catalyst also exhibits superior catalytic ability toward nerve agent simulants (diisopropyl fluorophosphate).The results of the study provide a firm basis for the use of UiO-66S as a future decontaminant for both nerve and blister agents.

Assessment of the Surveillance Interval at 1 Year after Curative Treatment in Hepatocellular Carcinoma: Risk Stratification.

Background/Aims: Guidelines recommend surveillance for hepatocellular carcinoma (HCC) recurrence at 3-month intervals during the first year after curative treatment and 6-month intervals thereafter in all patients. This strategy does not reflect individual risk of recurrence. We aimed to stratify risk of recurrence to optimize surveillance intervals 1 year after treatment. Methods: We retrospectively analyzed 1,316 HCC patients treated with resection/radiofrequency ablation at Barcelona Clinic Liver Cancer stage 0/A. In patients without 1-year recurrence under 3-monthly surveillance, a new model for recurrence was developed using backward elimination methods: training (n=582)/validation cohorts (n=291). Overall survival (OS) according to risk stratified by the new model was compared according to surveillance intervals: 3-monthly versus 6-monthly (n=401) after lead time bias correction and propensity-score matching analyses. Results: Among patients without 1-year recurrence, age and international normalized ratio values were significant factors for recurrence (hazard ratio [HR], 1.03; 95% confidence interval [CI], 1.00 to 1.03; p=0.009 and HR, 5.63; 95% CI, 2.24 to 14.18; p<0.001; respectively). High-risk patients stratified by the new model showed significantly higher recurrence rates than low-risk patients in the validation cohort (HR, 1.73; 95% CI, 1.18 to 2.53; p=0.005). After propensity-score matching between the 3-monthly and 6-monthly surveillance groups, OS in high-risk patients under 3-monthly surveillance was significantly higher than that under 6-monthly surveillance (p=0.04); however, OS in low-risk patients under 3-monthly surveillance was not significantly different from that under 6-monthly surveillance (p=0.17). Conclusions: In high-risk patients, 3-monthly surveillance can prolong survival compared to 6-monthly surveillance. However, in low-risk patients, 3-monthly surveillance might not be beneficial for survival compared to 6-monthly surveillance.

Comparison of physical function according to the lumbar movement method of stabilizing a patient with chronic low back pain.

[Purpose] The purpose of this study was to examine the changes caused by lumbar stabilization exercises in chronic low back pain patients. [Subjects and Methods] Swiss ball exercise regimen group and sling exercise regimen group exercised for 30 minutes a day, 5 days a week, for 12 weeks. The control group was to continue performing their usual daily living activities. [Results] We obtained significant results in both the Swiss ball and sling exercise groups, but not in the control group. The best effect was obtained in the sling exercise group. [Conclusion] The Oswestry Low Back Pain Disability Index and visual pain scale scores of the patients with low back pain decreased in both the Swiss ball exercise group and the sling exercise group, and these patients experienced an increase in waist isometric muscular strength after 12 weeks of exercise compared with those doing no exercise (the control group).

An Optimized Adsorbent Sampling Combined to Thermal Desorption GC-MS Method for Trimethylsilanol in Industrial Environments.

Trimethylsilanol (TMSOH) can cause damage to surfaces of scanner lenses in the semiconductor industry, and there is a critical need to measure and control airborne TMSOH concentrations. This study develops a thermal desorption (TD)-gas chromatography (GC)-mass spectrometry (MS) method for measuring trace-level TMSOH in occupational indoor air. Laboratory method optimization obtained best performance when using dual-bed tube configuration (100 mg of Tenax TA followed by 100 mg of Carboxen 569), n-decane as a solvent, and a TD temperature of 300°C. The optimized method demonstrated high recovery (87%), satisfactory precision (<15% for spiked amounts exceeding 1 ng), good linearity (R(2) = 0.9999), a wide dynamic mass range (up to 500 ng), low method detection limit (2.8 ng m(-3) for a 20-L sample), and negligible losses for 3-4-day storage. The field study showed performance comparable to that in laboratory and yielded first measurements of TMSOH, ranging from 1.02 to 27.30 µg/m(3), in the semiconductor industry. We suggested future development of real-time monitoring techniques for TMSOH and other siloxanes for better maintenance and control of scanner lens in semiconductor wafer manufacturing.