• Journal of Pharmaceutical Investigation
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• v.24 no.3
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• pp.115-129
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• 1994

In the present study, quantitative and qualitative histology was used to assess the effects of ibuprofen suppositories with various treatments on the rectal mucosa of rats. Two suppositories were prepared with Witepsol W35 and compared with two commercial ibuprofen suppositories Reference I (Showa Pharm.ind., Tokyo, Japan), Reference II (P.Pharm., Seoul, Korea). Single and multiple dose(dosing interval 4 hr, n=4) studies were conducted. All suppositories significantly increased epithelial cell loss, but the extent of rectal irritation was variable. These studies showed that the incorporation of ibuprofen into the suppository bases increases the morphological change in rectal tissue both for the single and multiple administrations of suppositories, but which was significantly recovered within 24 hr although the interanimal variability in scores was very substantial. Multiple administration of ibuprofen suppositories caused significant damage to rectal mucosa, but it must be considered that these were under the severe condition, that is, interval of administration (4 hr) was three times shorter than normal interval of administration and dose was fifteen times larger than usual human dose. Aluminum oxide $(Al_2O_3)$, a dispersing agent, slightly increased the irritation of rectal mucosa in rats at 5 hr and 24 hr after multiple administration, but it was possible to ignore the difference of irritation in the data at 5hr and 24hr after single administration. Finally, it was concluded that Witepsol W35 and ibuprofen had a slight rectal mucosa-irritating effect on the usual human dose, and ibuprofen suppositories prepared with Witepsol W35 or Witepsol W35, $Al_2O_3$ showed almost similar extent of rectal irritation with commercial ibuprofen products.

• Journal of the Earthquake Engineering Society of Korea
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• v.2 no.1
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• pp.95-111
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• 1998

In this study, the concepts and procedures of the seismic damage analysis methods are examined for both the element-level and the system-level. The seismic damage analysis at the element-level is performed for several example structures using existing method for structural elements or single-degree-of-freedom (SDOF) systems such as the Park and Ang method. In order to analyze seismic damage at the system-level, two types of procedures are used. In the first type of procedure, the system-level seismic responses can be estimated by using the system representative response method(SRRM), or the equivalent SDOF system response method (ESDOF-SRM). Then, the system-level seismic damage is analyzed from the system-level seismic responses using existing method for structural elements or SDOF systems. IN the second type of procedure, the system-level seismic damages are analyzed using the element damage combination method (EDCM) combing the element-level damage indices determined by existing method. To compare tendency of the seismic damage analysis using each methods, example analysis is accomplished for several cases of different structures and different earthquake excitation.

• Smart Structures and Systems
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• v.31 no.4
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• pp.335-349
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• 2023

Bridges constantly undergo deterioration and damage, the most common ones being concrete damage and exposed rebar. Periodic inspection of bridges to identify damages can aid in their quick remediation. Likewise, identifying components can provide context for damage assessment and help gauge a bridge's state of interaction with its surroundings. Current inspection techniques rely on manual site visits, which can be time-consuming and costly. More recently, robotic inspection assisted by autonomous data analytics based on Computer Vision (CV) and Artificial Intelligence (AI) has been viewed as a suitable alternative to manual inspection because of its efficiency and accuracy. To aid research in this avenue, this study performs a comparative assessment of different architectures, loss functions, and ensembling strategies for the autonomous segmentation of bridge components and damages. The experiments lead to several interesting discoveries. Nested Reg-UNet architecture is found to outperform five other state-of-the-art architectures in both damage and component segmentation tasks. The architecture is built by combining a Nested UNet style dense configuration with a pretrained RegNet encoder. In terms of the mean Intersection over Union (mIoU) metric, the Nested Reg-UNet architecture provides an improvement of 2.86% on the damage segmentation task and 1.66% on the component segmentation task compared to the state-of-the-art UNet architecture. Furthermore, it is demonstrated that incorporating the Lovasz-Softmax loss function to counter class imbalance can boost performance by 3.44% in the component segmentation task over the most employed alternative, weighted Cross Entropy (wCE). Finally, weighted softmax ensembling is found to be quite effective when used synchronously with the Nested Reg-UNet architecture by providing mIoU improvement of 0.74% in the component segmentation task and 1.14% in the damage segmentation task over a single-architecture baseline. Overall, the best mIoU of 92.50% for the component segmentation task and 84.19% for the damage segmentation task validate the feasibility of these techniques for autonomous bridge component and damage segmentation using RGB images.

• Earthquakes and Structures
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• v.25 no.2
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• pp.125-134
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• 2023

In the present work, a new global damage index is proposed for the seismic performance and failure analysis of concrete gravity dams. Unlike the existing indices of concrete structures, this index doesn't need scaling with an ultimate or an upper value. For this purpose, the Beni-Haroun dam in north-eastern Algeria, is considered as a case study, for which an average seismic capacity curve is first evaluated by performing several incremental dynamic analyses. The seismic performance point of the dam is then determined using the N2 method, considering multiple modes and taking into account the stiffness degradation. The seismic demand is obtained from the design spectrum of the Algerian seismic regulations. A series of recorded and artificial accelerograms are used as dynamic loads to evaluate the nonlinear responses of the dam. The nonlinear behaviour of the concrete mass is modelled by using continuum damage mechanics, where material damage is represented by a scalar field damage variable. This modelling, which is suitable for cyclic loading, uses only a single damage parameter to describe the stiffness degradation of the concrete. The hydrodynamic and the sediment pressures are included in the analyses. The obtained results show that the proposed damage index faithfully describes the successive brittle failures of the dam which increase with increasing applied ground accelerations. It is found that minor damage can occur for ground accelerations less than 0.3 g, and complete failure can be caused by accelerations greater than 0.45 g.

• Journal of Plant Biotechnology
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• v.31 no.3
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• pp.225-230
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• 2004

We employed single cell gel electrophoresis method (comet assay) to analyze the degree of nucleus-DNA damage in the leaves of red pepper (Capsicum annuum L.) seedlings exposed to $^{60}$ CO v-radiation stress. Nucleus-DNA damage was measured as the ratio of tail length (T) to head length (H) in individual comet image isolated from pepper leaf cell. The T/H ratio of control-cells and treated-cells at 50 or 100 Gy were 1.28 and 3.54 or 3.39, respectively, suggesting that nuclei of pepper cells were severely damaged in the integrity of DNA strand by the treatment of enhanced v-radiation. The percentage of head-DNA in control-cells was 76.8%, whereas those of 50 and 100 Gy treated-cells were 55.9% and 59.9%, respectively. Pretreatment of low dose (4 to 20 Gy) radiation to seeds decreased DNA-damage in the leaves of seedlings treated with high dose radiation at 50 or 100 Gy. In this experiment, we developed a sensitive, reliable and rapid method for evaluating genotoxic effect in the nuclei of plant cells by employing comet assay.

• Environmental Analysis Health and Toxicology
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• v.19 no.4
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• pp.335-344
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• 2004

Diesel exhaust particle (<2.5 ${\mu}{\textrm}{m}$, DEP$_{2.5}$) is known to be probarbly carcinogenic (IARC group 2A). DEP$_{2.5}$ contains organic compounds such as polycyclicaromatic hydrocarbon (PAH), heterocyclic compounds, phenols, and nitroarenes. Reactive oxygen species (ROS) are generated by DEP$_{2.5}$ without any biological activation system. Therefore, an alternative mechanism by which DEP$_{2.5}$ could be carcinogenic is known by the generation of oxidative DNA damage. The aim of this study was to investigate genotoxic effects of DEP$_{2.5}$ using single cell gel electrophoresis. In order to evaluate the mechanisms of DEP$_{2.5}$ genotoxicity, the rat micro-some mediated and DNA repair enzyme treated comet assays together with routine comet assay were performed. DEP$_{2.5}$ was collected from diesel engine bus and dichloromethane extract was obtained. The organic extract of DEP$_{2.5}$ revealed DNA damage itself in NIH/3T3 cells. And it showed both oxidative and microsome mediated DNA damages. Vitamin C as an model antioxidant reduced DNA damage in endonuclase III treated comet assay. One of flavonoid, galangin as a CYP1A1 inhibitor reduced DNA damage in the presence of S-9 mixture. Our results show that DEP$_{2.5}$ are genotoxic and a great source of oxidative stress, but antioxidants can significantly reduce oxidative DNA damages. And DEP$_{2.5}$ may contain indirect mutagens which can be inhibited by CYP inhibitors.d by CYP inhibitors.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.10a
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• pp.216-219
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• 2002

Conventional piezoelectric lead-zirconate-titanate (PZT) senor has high sensitivity, but it is very brittle. Recently polymer films such as polyvinylidene fluoride (PVDF) have been used use as a sensor. The advantages of PVDF are the flexibility and mechanical toughness. Simple process and possible several shapes are also additional advantages. PVDF sensor can be directly embedded and attached to a structure. In this study, PVDF sensor was embedded in single glass fiber/epoxy composites whereas PZT sensor with AE was attached to single fiber composites (SFC). Piezoelectric sensor responds to interfacial damage of SFC. The signals measured by PVDF sensor were compared to PZT sensor. PZT sensor detected the signals of fiber fracture, matrix crack, interfacial debonding and even sensor delamination, whereas PVDF sensor only detected fiber fracture signals so far, because PZT sensor is much more sensitive than current PVDF sensor. Wave voltage of fiber fracture measured by PVDF sensor was lower than that of PZT sensor, but the results of fast Fourier transform (FFT) analysis were same. Wave velocity using two PZT sensors was also studied to know the internal and surface damage effect of epoxy specimens.

• Journal of Biosystems Engineering
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• v.27 no.5
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• pp.391-398
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• 2002

During handling unitized products, they are subjected to a variety of environmental hazards. Shock and vibration hazards are generally considered the most damaging of the environmental hazards on a product and it may encounter while passing through the distribution environment. A major cause of shock damage to products is drops during manual handling. The increasing use of unitization of pallets has been resulted in a reduction of the shock hazards. This has caused an increasing interest in research focused on vibration caused dam age. Damage to the product by the vibration most often occurs when a product or a product component has a natural frequency that falls within the range of the forcing frequencies of the particular mode of transportation being used. Transportation vibration is also a major cause of fruit and vegetable quality loss due to mechanical damage. This study was conducted to determine the vibration characteristics of the corrugated fiberboard bones for packages of pears, and to investigate the degree of vibration injury of the pears in the boxes during the simulated transportation environment. The vibration tests were performed on an electrohydraulic vibration exciter. The input acceleration to exciter was fixed at 0.25 G for a single container resonance test and 0.5 G for the vertical stacked container over the frequency range from 3 to 100 Hz. Function generator (HP-33120A) was connected by wire to the vibration exciter for controlling the input acceleration at a continuous logarithmic sweep rate of 1.0 octave per min. The peak frequency and acceleration on the single box test were 22.02 Hz, 1.5425 G respectively, and these values on the vertical stacked boxes were observed from the bottom box 19.02, 18.14, 16.62 and 15.40 Hz and 2.2987, 3.7654. 5.6087, and 7.9582 G, respectively. The pear in the bottom box had a slightly higher damage level than the fruit packed in the other stacked boxes. It is desirable that the package and transportation system has to be so designed that 15∼20 Hz frequency will not occur during the transportation environment.

• Journal of Food Hygiene and Safety
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• v.17 no.2
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• pp.106-116
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• 2002

The 70% ethanol extract of Alpinia officinarum and its major flavonoid, galangin showed strong antioxidative effect on the lipid peroxidation of ethyl linolate with Fenton's reagent and free radical scavenging effect to DPPH radical generation. However, they did not reveal any pro-oxidant effect on bleomycin-Fe(III) dependent DNA degradation. They also showed the protective effect against $H_2O$$_2$, KO$_2$ or UV-induced cytotoxicity in mammalian cells. They also showed the suppressive effect of DNA damage induced by $H_2O$$_2$ or KO$_2$ with dose-dependent manner in single cell gel electrophoresis(SCGE) assay. On the other hand, they have an anticlastogenic effect against adriamycin-induced micronucleated reticulocyte in peripheral blood of mice. These results suggest that the mechanism of inhibition by 70% ethanol extract of Alpinia officinarum and galangin against reactive oxygen species (ROS)-induced genotoxicity or cytotoxicity is due, at least partly, to their antioxidative and free radical scavenging properties without pro-oxidant effect. All these results indicate that 70% ethanol extract of Alpinia officinarum and galangin may be useful for protection against ROS-induced cytotoxicity and DNA damage.

• Clinical and Experimental Reproductive Medicine
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• v.48 no.3
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• pp.211-220
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• 2021

Objective: The present study aimed to investigate the possibility that curcumin (CMN) protects against methotrexate (MTX)-induced testicular damage by affecting the phospho-p38 (p-p38) mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) signaling pathways. Methods: Eighteen male Wistar albino rats were randomly divided into three groups. The control group was given an intragastric administration of dimethyl sulfoxide (DMSO) daily for 14 days, the MTX group was given a single intraperitoneal dose of MTX (20 mg/kg) on the 11th day, and the MTX+CMN group was given intragastric CMN (100 mg/kg/day, dissolved in DMSO) for 14 days and a single intraperitoneal dose of MTX (20 mg/kg) on the 11th day. At the end of the experiment, all animals were sacrificed and the testicular tissues were removed for morphometry, histology, and immunohistochemistry. Body and testicular weights were measured. Results: Body weights, seminiferous tubule diameter, and germinal epithelium height significantly decreased in the MTX group compared to the control group. Whereas, the number of histologically damaged seminiferous tubules and interstitial space width significantly increased in the MTX group. In addition, the number of p-p38 MAPK immunopositive cells and the immunoreactivity of NF-κB also increased in the MTX group compared to the control group. CMN improved loss of body weight, morphometric values, and histological damage due to MTX. CMN also reduced the number of p-p38 MAPK immunopositive cells and the NF-κB immunoreactivity. Conclusion: CMN may reduce MTX-induced testicular damage by suppressing the p38 MAPK and NF-κB signaling pathways.