927 research outputs found
Crash simulation and development of automotive bumper impact beam design for weight reduction
Increasing fuel economy has been a principal issue in the development of new cars. Decrease in weight of vehicle components is one of the important approaches to solving the problem. In order to obtain the goal, researches sought for ways to design lighter and stronger bumper impact beams relinquishing neither impact absorbing capacity of bumpers nor the safety of vehicles. In this paper, a possible weight reduction of impact beam is examined by substituting conventional type of steel with high-strength steel (boron steel having tensile strength 1.5 GPa) with regard to variables such as frontal, offset and corner impact crash capability of a bumper impact beam. In addition, the effects of variation in structural differences in bumper impact beams (open section, closed section, open section with 5 stays) were carefully considered. Arguably, this analysis presents a good guide for an optimum design and development of bumper impact beams
Crash simulation and development of automotive bumper impact beam design for weight reduction
Increasing fuel economy has been a principal issue in the development of new cars. Decrease in weight of vehicle components is one of the important approaches to solving the problem. In order to obtain the goal, researches sought for ways to design lighter and stronger bumper impact beams relinquishing neither impact absorbing capacity of bumpers nor the safety of vehicles. In this paper, a possible weight reduction of impact beam is examined by substituting conventional type of steel with high-strength steel (boron steel having tensile strength 1.5 GPa) with regard to variables such as frontal, offset and corner impact crash capability of a bumper impact beam. In addition, the effects of variation in structural differences in bumper impact beams (open section, closed section, open section with 5 stays) were carefully considered. Arguably, this analysis presents a good guide for an optimum design and development of bumper impact beams
Association Study of FOS-Like Antigen-2 Promoter Polymorphisms With Papillary Thyroid Cancer in Korean Population
ObjectivesFOS-like antigen-2 (FOSL-2), a member of the FOS gene family, encode leucine zipper proteins that can heterodimerize with proteins of Jun family. Thus, activating protein (AP)-1 transcription factor is formed, has a crucial role in proliferation, differentiation and apoptosis of normal tissue as well as oncogenic transformation and progression. We performed an association study of single nucleotide polymorphisms (SNPs) in the FOSL-2 with papillary thyroid cancer (PTC). We also estimated the relationships between the SNPs and the clinicopathologic characteristics of PTC.MethodsOne promoter SNPs (rs925255) of FOSL-2 gene were genotyped with direct sequencing method in 94 PTC and 213 controls. PTC patients were dichotomized and compared with respect to clinical parameters of PTC. Genetic data were analyzed using Helixtree, SNPAnalyzer, SNPStats. Multivariate logistic regression analysis was fulfilled to evaluate the genetic effect with adjustment for age and sex.ResultsSNP (rs925255) in FOSL-2 showed a significant association (codominant 1 model [G/G vs. A/G]: odds ratio [OR], 0.531, 95% confidence interval [CI], 0.293 to 0.96, P=0.036; dominant model: OR, 0.50, 95% CI, 0.28 to 0.89, P=0.015) with PTC. The frequency of allele G in rs925255 was also significantly associated with PTC (OR, 0.59; 95% CI, 0.34 to 0.91; P=0.02). But we fail to prove significant association between this polymorphism (rs925255) and clinico-pathological parameters.ConclusionOur findings suggest that the rs925255 SNP and its allele G show significant association with the PTC in Korean population
Relationship Between Functional Level and Muscle Thickness in Young Children With Cerebral Palsy
ObjectiveTo investigate the relationship between functional level and muscle thickness (MT) of the rectus femoris (RF) and the gastrocnemius (GCM) in young children with cerebral palsy (CP).MethodsThe study participants were comprised of 26 children (50 legs) with spastic CP, aged 3–6 years, and 25 age-matched children with typical development (TD, 50 legs). The MT of the RF, medial GCM, and lateral GCM was measured with ultrasound imaging. The functional level was evaluated using the Gross Motor Function Measurement-88 (GMFM-88), Gross Motor Function Classification System (GMFCS), and based on the mobility area of the Korean version of the Modified Barthel Index (K-MBI). The measurement of spasticity was evaluated with the Modified Ashworth Scale (MAS).ResultsWe note that the height, weight, body mass index, and MT of the RF, and the medial and lateral GCM were significantly higher in the TD group (p<0.05). There was a direct relationship between MT of the RF and medial GCM and the GMFM-88, GMFCS, and mobility scores of the K-MBI in individuals with early CP. In addition, we have noted that there was a direct relationship between MT of the lateral GCM and the GMFM-88 and GMFCS. Although there was a tendency toward lower MT with increasing MAS ratings in the knee and ankle, the correlation was not statistically significant.ConclusionIn young children with CP, MT of the RF and GCM was lower than in age-matched children with TD. Furthermore, it is noted with confidence that a significant positive correlation existed between MT and functional level as evaluated using the GMFM-88, GMFCS, and mobility area of K-MBI
The combination effect of sodium butyrate and 5-Aza-2'-deoxycytidine on radiosensitivity in RKO colorectal cancer and MCF-7 breast cancer cell lines
<p>Abstract</p> <p>Background</p> <p>The overall level of chromatin compaction is an important mechanism of radiosensitivity, and modification of DNA methylation and histone deacetylation may increase radiosensitivity by altering chromatin compaction. In this study, we investigated the effect of a demethylating agent, a histone deacetylase(HDAC) inhibitor, and the two agents combined on radiosensitivity in human colon and breast cancer cell lines.</p> <p>Methods</p> <p>In this study, we used RKO colorectal cancer cell line and MCF-7 breast cancer cell lines and normal colon cell lines. On each of the cell lines, we used three different agents: the HDAC inhibitor sodium butyrate(SB), the demethylating agent 5-Aza-2'-deoxycytidine(5-aza-DC), and radiation. We then estimated the percentage of the cell survival using the XTT method and experimented to determine if there was an augmentation in the therapeutic effect by using different combinations of the two or three of the treatment methods.</p> <p>Results</p> <p>After treatment of each cell lines with 5-aza-DC, SB and 6 grays of radiation, we observed that the survival fraction was lower after the treatment with 5-aza-DC or SB than with radiation alone in RKO and MCF-7 cell lines(p < 0.001). The survival fraction was lowest when the two agents, 5-aza-DC and SB were combined with radiation in both RKO and MCF-cell lines.</p> <p>Conclusion</p> <p>In conclusion, 5-aza-DC and SB can enhance radiosensitivity in both MCF-7 and RKO cell lines. The combination effect of a demethylating agent and an HDAC inhibitor is more effective than that of single agent treatment in both breast and colon cancer cell lines.</p
A study on fire design accidental loads for aluminum safety helidecks
AbstractThe helideck structure must satisfy the safety requirements associated with various environmental and accidental loads. Especially, there have been a number of fire accidents offshore due to helicopter collision (take-off and/or landing) in recent decades. To prevent further accidents, a substantial amount of effort has been directed toward the management of fire in the safety design of offshore helidecks. The aims of this study are to introduce and apply a procedure for quantitative risk assessment and management of fires by defining the fire loads with an applied example. The frequency of helicopter accidents are considered, and design accidental levels are applied. The proposed procedures for determining design fire loads can be efficiently applied in offshore helideck development projects
Multiple Sclerosis and Peripheral Multifocal Demyelinating Neuropathies Occurring in a Same Patient
The co-occurrence of multiple sclerosis and peripheral demyelinating neuropathy is rare. It has been disputed whether these are pathologically related or coincidental findings. We report a 36-year-old woman who presented with diplopia, right facial palsy and left-sided weakness. Brain magnetic resonance imaging showed a lesion indicative of central demyelinating disease. Nerve conduction studies revealed peripheral multifocal demyelinating neuropathies. We suggest that the central and the peripheral lesions may be continua of a demyelinating process
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