• Smart Structures and Systems
• /
• v.30 no.6
• /
• pp.639-648
• /
• 2022

This study aims at numerically and experimentally investigating torsional guided wave mixing with weak material nonlinearity under acoustoelastic effect in tubular structures. The acoustoelastic effect on single central frequency guided wave propagation in structures has been well-established. However, the acoustoelastic on guided wave mixing has not been fully explored. This study employs a three-dimensional (3D) finite element (FE) model to simulate the effect of stress on guided wave mixing in tubular structures. The nonlinear strain energy function and theory of incremental deformation are implemented in the 3D FE model to simulate the guided wave mixing with weak material nonlinearity under acoustoelastic effect. Experiments are carried out to measure the nonlinear features, such as combinational harmonics and second harmonics in related to different levels of applied stresses. The experimental results are compared with the 3D FE simulation. The results show that the generation combinational harmonic at sum frequency provides valuable stress information for tubular structures, and also useful for damage diagnosis. The findings of this study provide physical insights into the effect of applied stresses on the combinational harmonic generation due to wave mixing. The results are important for applying the guided wave mixing for in-situ monitoring of structures, which are subjected to different levels of loadings under operational condition.

• Toxicological Research
• /
• v.16 no.3
• /
• pp.195-200
• /
• 2000

Antidotal efficacy of physostigmine plus procyclidine, the combinational prophylactics for organophosphate poisoning, was evaluated in rats and guinea pigs. To assess the dose-response relation-ship in rats, various doses (0.3-6.0mg/kg) of procyclidine in combination with a fixed dose (0.1mg/kg) of physostigmine were pretreated subcutaneously 30 min prior to subcutaneous exposure to nerve-agents. Physostigmine alone exerted protection ratios of 2.44, 1.20, 1.50, 1.50 and 2.20 folds for tabun, sarin, soman, cyclosarin and V-agent, respectively. Interestingly, coadmnistration of procyclidine with physostigmine exhibited remarkable synergistic effects in a dose-dependent manner, leading to 4.00~8.00 folds for tabun, 2.15-8.50 folds for sarin, 1.92~507 folds for so man, 2.15~2.90 folds for cyclosarin, and 2.71~10.50 folds for V-agent. On the contrary, a low effect (l.65 fold) was achieved with the traditional antidotes atropine (17.4 mg/kg) plus 2-pralidoxime (30 mg/kg) treated immediately after soman poisoning. Noteworthy, the combinational prophylactics markedly potentiated the effect of atropine plus 2-pralidoxime to 6.13 and 12.27 folds with 1.0 and 3.0 mg/kg of procyclidine, respectively, against soman poisoning. In guinea pigs, the physostigmine plus procyclidine prophylactics exerted protective effects of 3.00~4.70 folds against soman intoxcation, which were much higher at low doses (0.3~1.0 mg/kg) of procyclidine than those in rats. Taken together, it is proposed that the combinational prophylactics composed oj physostigmine and procyclidine could be a promising antidote regimen for the poisoning with organophosphates possessing diverse properties.

• Journal of Sensor Science and Technology
• /
• v.28 no.1
• /
• pp.17-22
• /
• 2019

As CMOS technology scales down, reliability is becoming an important concern for VLSI designers. This paper analyzes gate-oxide breakdowns (i.e., the time-dependent dielectric-breakdown (TDDB) aging effect) as a reliability issue for combinational circuits with 45-nm technology. This paper shows simulation results for the noise margin, delay, and power using a single inverter-chain circuit, as well as the International Symposium on Circuits and Systems (ISCAS)'85 benchmark circuits. The delay and power variations in the presence of TDDB are also discussed in the paper. Finally, we propose a novel method to compensate for the logic failure due to dielectric breakdowns: We used a higher supply voltage and a negative ground voltage for the circuit. The proposed method was verified using the ISCAS'85 benchmark circuits.

• Journal of Haehwa Medicine
• /
• v.17 no.2
• /
• pp.51-68
• /
• 2008

The effect of combinational treatment of oral HTGMB and topical CSGMB ("H&C" hereinafter) on the changes of dermal inflammation index and immune system were studied using NC/Nga atopic dermatitis animal model. 1. Through naked eye examination, H&C ameliorated atopic dermatitis compared to the control group. Significant reduction of dermal inflammation index was observed after 12 weeks of treatment. 2. The H&C treated group showed 51% increase in the number of immune cells in DLN, and 59% increase in the number of immune cells is dorsal skin. 3. The H&C treated group showed decrease of 26%, 8%, 59% in CD19+, CD3+/CD69+, B220+/IgE+ cells in DLN respectively. On the other hand, CD3+, CD8+, CD4+ cells were increased by 8%, 31%, 12%, respectively. 4. The H&C treated group showed significant decrease of 38% and 47% in B220+/IgE+, CD11b+/Gr-1+ cells within dorsal skin respectively. Also, a decrease in CCR3+ cells by 21% was observed. 5. Significant decrease of the production of IL-4, IL-5, GM-CSF by 39%, 65%, 60% respectively, in spleen cells activated with CD3 and CD28 were observed in the H&C treated group. The results above strongly suggest significance of anti-atopic dermatitis effect of combinational treatment of oral HTGMB and topical CSGMB through immune modulation. Further applications in clinical use of the treatment are anticipated.

• Journal of fish pathology
• /
• v.37 no.1
• /
• pp.133-138
• /
• 2024

This study is a report on combinational effects between four sesquiterpene lactones (SLs) from bay laurel (Laurus nobilis) leaves, and oxytetracycline (OTC) or amoxicillin (AMX) against four fish pathogenic bacteria such as Vibrio anguillarum, V. harveyi, Edwardsiella tarda, and Streptococcus iniae. Individually, four SLs exerted little antibacterial activity against fish pathogenic bacteria. However, when combined with OTC or AMX, they showed synergistic interaction against pathogenic bacteria. Especailly, zaluzanin C (1) reduced the MIC of OTC (or AMX) eight-fold. Our results showed that combinations of SLs with antibiotics (ABTs) are more effective than ABTs alone to control pathogenic bacteria. The highest synergistic effect was observed when zaluzanin C (1) was combined with OTC or AMX against V. harvey or S. iniae, displaying significant reductions of MICs up to 8-fold (0.125 to 0.015 ㎍/mL and 0.0078 to 0.0009 ㎍/mL). In addition, zaluzanin C (1) improved the antibiotic potency of OTC against OTC resistant V. harveyi (250 ㎍/mL to 62.5 ㎍/mL). Synergism between ABTs and phytochemical such as SLs could be a therapeutically helpful concept to improve the efficacy of ABTs and prevent antibiotic resistance. These results suggest that SLs can be used as an alternative to reduce antibiotic resistance in aquaculture.

• Journal of the Korean Chemical Society
• /
• v.58 no.6
• /
• pp.667-680
• /
• 2014

The purpose of this study was to develop teaching stratege focused on Conservational reasoning, Proportional reasoning, Variable-controlling reasoning, Probabilitic reasoning, Correlational reasoning, Combinational reasoning and investigate its effects on enhancing students' logical thinking skills through the science teaching on common education. And the teaching materials was implemented to 110 students in middle school over about six months. The results indicated that the experimental group presented statistically meaningful improvement in logical thinking skills (p<05). Especially, this teaching stratege was effective on Conservational reasoning, Variable-controlling reasoning, Combinational reasoning but was not effective on Proportional reasoning, Probabilitic reasoning, Correlational reasoning (p<.05). Logical thinking according to the teaching strategy skill was not affected by gender, cognitive level, academic achievement (p<.05).

• Journal of Welding and Joining
• /
• v.33 no.2
• /
• pp.14-17
• /
• 2015

Cleaning effect is well known mechanism of oxide layer removal in DCEP polarity. It is also known that DCEN has higher heat input efficiency than DCEP in GTAW process. Based on these two renowned arc theories, conventional variable polarity arc for aluminum welding was set up to have minimum DCEP and maximum DCEN duty ratio to achieve the highest heat input efficiency and weldability increase. However, recent several variable polarity GTA research papers reported unexpected result of proportional relationship between DCEP duty ratio and heat input. The authors also observed the same result then suggested combination of tunneling effect and random walk of cathode spot to fill up the gap between experiment and conventional arc theory. In this research, suggested combinational work of tunneling effect and rapid cathode spot changing is applied to another unexpected phenomena of variable polarity aluminum arc welding. From previous research, it is reported that wider oxide removal range, narrower bead width and shallower penetration depth are observed in thin oxide layered aluminum compared to the case of thick oxide. This result was reported for the first time and it was hard to explain the reason at that time therefore the inference by the authors was hardly acceptable. However, the suggested combinational theory successfully explains the result of the previous report in logical way.

• Journal of the Korean Applied Science and Technology
• /
• v.36 no.4
• /
• pp.1172-1180
• /
• 2019

It was studied whether fenofibrate alone or combinational treatments of fenofibrate and 17β-estradiol regulates serum lipid levels, and whether the effects of fenofibrate on serum lipid metabolism are affected by co-administration of 17β-estradiol in low-fat diet-fed ovariectomized female mice. Compared with low-fat diet-fed controls, mice treated with fenofibrate alone and mice treated with fenofibrate and 17β-estradiol didn't decrease body weight at 8 weeks. Fenofibrate alone or combinational treatments of fenofibrate and 17β-estradiol did not regulate serum levels of total cholesterol and HDL-cholesterol. Fenofibrate decreased plasma levels of LDL-cholesterol and triglycerides compared with controls. The combinational treatments of fenofibrate and 17β-estradiol showed more beneficial effects on triglycerides than fenofibrate alone. Therefore, the present study found that serum triglycerides reduced by fenofibtae treatment alone could be more improved by combinational treatments of fenofibrate and 17β-estradiol in low-fat diet-fed ovariectomized female mice.

• The Korea Journal of Herbology
• /
• v.32 no.1
• /
• pp.1-13
• /
• 2017

Objective : Soybeans of Canavalia gladiata(CG) and root of Arctium lappa(AL) have been reported to have anti-inflammatory, antioxidant effect. However, the immunoregulatory mechanisms of its combinational prescription remain a matter of considerable debate. In the current study, we investigated whether CG and AL and its combinational prescription(CG+AL) regulate immune system using chronic immobilization-stress mouse model. Methods : C57BL/6J mice fixed for 2 hours into immobilization tube after CG, AL, CG+AL oral administration after 2 hours daily for 21 days. After every experiment has ended the C57BL/6J mice were sacrificed on 22 days. The production of Serotonin and Cortisol, lgA were observed by ELISA method, The proportion of immune cells such as T/B cell and macrophage, NK cell were measured by FACS. Then, Real-time PCR was performed to measure the mRNA expression of Inflammatory cytokines(IL-1beta, IL-6, TNF-a) and T cell activation cytokines(IL-2, IL-10, IFN-gamma, IL-12p35 / p40). Result : When chronic immobilization-stress mouse model were treated with CG+AL(1:4), the expression of mRNA were significantly decreased at the Inflammatory cytokines(IL-1beta, IL-6, TNF-a). While, the levels of mRNA were significantly increased at immune T cell activation cytokines. Additionally, CG+AL(1:4) combinational prescription group enhanced immune cells such as T/B cell and macrophage, NK cell. Furthermore, the Immuno-fluorescence result of brain tissue can confirm that CG+AL(1:4) group significantly increased the BDNF expression. Conclusion : These result suggest that CG+AL(1:4) combinational prescription has Immune System enhancement via stress-mediated immunocyte.

• Toxicological Research
• /
• v.16 no.3
• /
• pp.187-193
• /
• 2000

The antidotal, anticonvulsant and neuroprotective effects of physostigmine and procyclidine. the combinational prophylactics for organophosphate poisoning, were evaluated in rats. In comparison with a low protective effect (1.6 fold) of atropine (15 mg/kg) and 2-pralidoxime (30 mg/kg), the traditional antidotes regimen, a marked protection ratio of 7.3 fold was achieved by combinational pretreatment with physostigmine (0.05 mg/kg) and procyclidine (10 mg/kg), which was superior to that (3.5 fold) with pyri-dostigmine (0.1 mg/kg) and atropine (15 mg/kg). Rats exposed to a high dose (10 mg/kg. 2 X $LD_{50}$) of diisopropylfluorophosphate showed severe epileptiform seizures on electroencephalography, resulting in necrotic and apoptotic brain injuries in discrete brain regions under histopathological and TUNEL immuno-histochemical examinations in 24 hr. Such seizures and excitotoxic brain injuries were fully prevented by pretreatment with physostigmine (0.05 mg/kg) and procyclidine (10 mg/kg). in contrast to a negligible effect of pyridostigmine (0.1 mg/kg) and atropine (15 mg/kg). Taken together, it is proposed that the prophylactics composed of physostigmine and procyclidine could be a promising regimen for the prevention of lethality, seizures and brain injuries induced by organophosphate poisoning.