• Journal of Radiation Protection and Research
• /
• v.48 no.1
• /
• pp.1-8
• /
• 2023

Background: The purpose of this study is to evaluate the immunosuppressive and antioxidant effects of a novel radioprotective agent using the vitamin E derivative 2-(alpha-D-glucopyranosyl)methyl-2,5,7,8-tetramethylchroman-6-ol (TMG) and its effect on tumors, and to study its usefulness. Materials and Methods: In this study, C57BL/6NCrSlc mice were divided into four groups (control, TMG, radiation therapy [RT], and RT+TMG), using 10 mice in each group. In the TMG and 2 Gy+TMG groups, 500 mg/kg TMG was administered. Two groups (2 Gy and 2 Gy+TMG) among RT and RT+TMG groups were irradiated with 2 Gy in a single fraction, while the other two groups (6 Gy and 6 Gy+TMG) were irradiated locally with 6 Gy in three fractions. Results and Discussion: TMG positively affected CD4+ and CD8+ T lymphocytes. Tumor volumes and growth inhibition rates were compared. In order to evaluate how TMG administration affected tumor growth, Ehrlich cancer cells were injected into the thigh of mice, and the tumor volume and growth suppression rate were compared. Not only RT but also TMG alone inhibited tumor growth. If RT conducted to the mice with TMG, TMG could increase the number of leukocytes, primarily that of lymphocytes. TMG also inhibited tumor growth in addition to RT. Tumor growth was significantly inhibited in the 6 Gy+TMG group. Conclusion: In conclusion, TMG exerted an immunopotentiating effect mainly by increasing the white blood cell numbers including that of lymphocytes. In addition to RT, TMG also inhibited tumor growth. Therefore, TMG is considered to be a useful radioprotective agent in radiotherapy without tumor growth induction.

• Korean Chemical Engineering Research
• /
• v.54 no.5
• /
• pp.648-652
• /
• 2016

The study of $CO_2$ absorption in a packed column by 1,1,3,3-tetramethylguanidine (TMG) dissolved in ethylene glycol is presented. Absorption column of inner diameter 1 in and 0.6 m length was filled with Protruded-packing $0.16in{\times}0.16in$. We investigated the effect of operating conditions on overall mass transfer coefficients as well as on $CO_2$ removal efficiency. The loading values reached at about $1.0mol_{CO2}/mol_{TMG}$. In case of absorbent with lean $CO_2$ loading, the overall mass transfer coefficient was proportional to the concentration of TMG. However, in the range of more than ${\alpha}=0.5molCO_2/molTMG$, the overall mass transfer coefficients decreased with the concentration of TMG. It is due to the increasing of mass transfer resistance in liquid phase as increasing of viscosity at higher loading values.

• Applied Chemistry for Engineering
• /
• v.8 no.2
• /
• pp.308-314
• /
• 1997

The effects of catalyst and blocking reagents(BR) on the blocking reactions of TDI and MDI in the preparation of polyurethane varnishes have been studied. It was found that certain types of catalysts, such as 1,4-diazabicyclo[2.2.2]octane(DABCO) and tetramethyl guanidine(TMG), were necessary to complete the NCO blocking reactions. Blocking rate of TMG was shown much faster than that of DABCO. Reactivity increased with the increase of TMG concentration, at least to the concentration of 1%. In case of DABCO, the 0.25% concentration of catalyst showed the highest reactivity. In order to study the steric effects of BR on the blocking reactions, phenol, p-cresol, m-cresol, o-cresol, 2,4-xylenol were used as blocking reagents. As expected, BR which has less steric hindrance showed higher reactivity. The increase in BR concentration and reaction temperature increased the productivity of polyurethanes in this reaction system.

• Journal of Digital Convergence
• /
• v.18 no.10
• /
• pp.547-555
• /
• 2020

To investigate the effects of self-management programs for chronic low back pain (LBP), 63 subjects were assigned to three groups; self-exercise group (SEG), hot pack and low-frequency electrical stimulation group (HEG), and thermo-massage group (TMG). Parameters were the pain numeric rating scale (PNRS), Oswestry Disability Index (ODI), Roland Morris Disability Questionnaire (RMDQ) and Relapse frequency (RF). PNRS, ODI and RMDQ of SEG and TMG sustained effectiveness, however, PNRS, which improved after treatment in HEG, worsened in 6 month. Between the groups, all parameters were better in SEG and TMG compare to HEG. Exercise and thermo-massage can be considered as useful self-management performed at home to prevent the relapse of chronic LBP.

• Food Science and Biotechnology
• /
• v.17 no.2
• /
• pp.302-307
• /
• 2008

Novel amylase inhibitors were synthesized via transglycosylation by Thermotoga maritima glucosidase (TMG). TMG hydrolyzes acarbose, acarviosine-glucose, and maltooligosaccharide by releasing $^{14}C$-labeled glucose from the reducing end of each molecule. When TMG was incubated with acarviosine-glucose (the donor) and glucose (the acceptor), two major transfer products, compounds 1 and 2, were formed via transglycosylation. The structures of the transfer products were determined using thin-layer chromatography (TLC), high-performance ion chromatography (HPIC), and $^{13}C$ nuclear magnetic resonance (NMR) spectroscopy. The results indicate that acarviosine was transferred to glucose at either C-6, to give a $\alpha-(1{\rightarrow}6$) glycosidic linkage, or at C-3, to produce an $\alpha-(1{\rightarrow}3$) glycosidic linkage. The transfer products showed a mixed-type inhibition against porcine pancreatic $\alpha$-amylase; therefore, they may be useful not only as inhibitors but also as acarbose transition-state analogs to study the mechanism of amylase inhibition.

• Archives of Plastic Surgery
• /
• v.49 no.4
• /
• pp.494-500
• /
• 2022

Background Seroma formation is the most common donor site complication following autologous breast reconstruction, along with hematoma. Seroma may lead to patient discomfort and may prolong hospital stay or delay adjuvant treatment. The aim of this study was to compare seroma rates between the deep inferior epigastric perforator (DIEP), transverse musculocutaneous gracilis (TMG), and superior gluteal artery perforator (SGAP) donor sites. Methods The authors conducted a retrospective single-center cohort study consisting of chart review of all patients who underwent microsurgical breast reconstruction from April 2018 to June 2020. The primary outcome studied was frequency of seroma formation at the different donor sites. The secondary outcome evaluated potential prognostic properties associated with seroma formation. Third, the number of donor site seroma evacuations was compared between the three donor sites. Results Overall, 242 breast reconstructions were performed in 189 patients. Demographic data were found statistically comparable between the three flap cohorts, except for body mass index (BMI). Frequency of seroma formation was highest at the SGAP donor site (75.0%), followed by the TMG (65.0%), and DIEP (28.6%) donor sites. No association was found between seroma formation and BMI, age at surgery, smoking status, diabetes mellitus, neoadjuvant chemotherapy, or DIEP laterality. The mean number of seroma evacuations was significantly higher in the SGAP and the TMG group compared with the DIEP group. Conclusion This study provides a single center's experience regarding seroma formation at the donor site after microsurgical breast reconstruction. The observed rate of donor site seroma formation was comparably high, especially in the TMG and SGAP group, necessitating an adaption of the surgical protocol.

• ETRI Journal
• /
• v.16 no.3
• /
• pp.1-10
• /
• 1994

Undoped GaAs has been successfully grown by chemical beam epitaxy (CBE) via surface decomposition process using arsine $(AsH_3)$ and trimethylgallium (TMG). Three distinct regions of temperature-dependent growth rates were identified in the range of temperatures from 570 to $690^{\circ}C$. The growth rates were found strongly dependent on the V/III ratio between 5 and 30. The growth rate at low V/III ratio seems to be determined by arsenic produced on the surface, whereas at high V/III ratio it shows dependence on the adsorption of TMG. Hall measurement and photoluminescence (PL) analysis show that the films are all p-type and that carbon impurities are primarily responsible for the background doping. Carbon concentrations have been found to be reduced by two orders of magnitude as compared to those of epilayers grown by CBE which employs TMG and arsenic obtained from precracked $AsH_3$ in a high temperature cell. It was also found that hydrogen atoms dissociated from unprecracked $AsH_3$ play an important role in removing hydrocarbon-containing species resulting in a significant reduction of car-bon impurities.

• Korean Journal of Environmental Agriculture
• /
• v.33 no.4
• /
• pp.290-297
• /
• 2014

BACKGROUND: The current study purposed to analyse the dissipation levels of a neonicotinoid insecticide and clothianidin in paddy and upland soils and clarify the effects of soil moisture on degradation and persistence of the insecticide. METHODS AND RESULTS: In order to achieve the research purposes, clothianidin 8% SG was applied to the paddy and upland fields at the rate of 0.024 kg a.i./10a, while the analytical standard was treated at 0.25 mg/kg soil under laboratory conditions. Based on the multiple first-order kinetics, total clothianidin in soils was dissipated with $DT_{50}$ of 6.7-16.1 and 6.9-8.2 days in the paddy and upland fields, respectively, whereas the figures under the laboratory condition became larger showing 56.3 and 19.6 days. CONCLUSION: As affected by soil moisture, some differences in degradative pathways were observed. Flooding of soil caused evidently demethylation and delayed cyclization of a major metabolite, thiazolylmethylguanidine (TMG) and methylaminoimidazole(MAI), compared to the aerobic upland condition. More than 80% and 50% of the parent compound was dissipated by the 24th day after the final application in both soils and, transformation products had constituted most of soil residues after that.

• Korean Journal of Pharmacognosy
• /
• v.44 no.2
• /
• pp.168-175
• /
• 2013

Aldose reductase (AR) plays a central role in the development of the diabetic complications. Eighty one Korean herbal medicines have been investigated for inhibitory activities on AR. Among them, fourteen herbal medicines exhibited a significant inhibitory activity compared with 3,3-tetramethyleneglutaric acid (TMG) as positive control. Particularly, Xanthium strumarium (fruit, whole plant), Ilex cornuta (stem and leaf), Vitex rotundifolia(stem), Sophora flavescens (whole plant), Platycarya stobilacea (flower) showed two times more potent inhibitory activity than 3,3-tetramethyleneglutaric acid (TMG).

• Bulletin of the Korean Chemical Society
• /
• v.30 no.8
• /
• pp.1805-1810
• /
• 2009

The adsorptions of trimethygallium (TMG) and arsine (As$H_3$) on H/Si(100)-2x1 surface were theoretically investigated. In the case of TMG adsorption, methane loss reaction, surface methylation, hydrogen loss reaction and ring closing reaction channels were found. The mechanism of As$H_3$ adsorption on the surface was also identified. Among these, the methane loss reaction depositing –Ga(C$H_3)_2$ was found to be the major channel due to its low barrier height and the large exothermicity. The surface methylation reaction is the second most favorable channel. In contrast, arsine turned out to be less reactive on the surface, implying that Arsine surface reaction would be the rate limiting step in the overall ALD process.