1,459 research outputs found
Recombinant mussel proximal thread matrix protein promotes osteoblast cell adhesion and proliferation
BACKGROUND: von Willebrand factor (VWF) is a key load bearing domain for mamalian cell adhesion by binding various macromolecular ligands in extracellular matrix such as, collagens, elastin, and glycosaminoglycans. Interestingly, vWF like domains are also commonly found in load bearing systems of marine organisms such as in underwater adhesive of mussel and sea star, and nacre of marine abalone, and play a critical load bearing function. Recently, Proximal Thread Matrix Protein1 (PTMP1) in mussel composed of two vWF type A like domains has characterized and it is known to bind both mussel collagens and mammalian collagens. RESULTS: Here, we cloned and mass produced a recombinant PTMP1 from E. coli system after switching all the minor codons to the major codons of E. coli. Recombinant PTMP1 has an ability to enhance mouse osteoblast cell adhesion, spreading, and cell proliferation. In addition, PTMP1 showed vWF-like properties as promoting collagen expression as well as binding to collagen type I, subsequently enhanced cell viability. Consequently, we found that recombinant PTMP1 acts as a vWF domain by mediating cell adhesion, spreading, proliferation, and formation of actin cytoskeleton. CONCLUSIONS: This study suggests that both mammalian cell adhesion and marine underwater adhesion exploits a strong vWF-collagen interaction for successful wet adhesion. In addition, vWF like domains containing proteins including PTMP1 have a great potential for tissue engineering and the development of biomedical adhesives as a component for extra-cellular matrix
Andro-Simnet: Android Malware Family Classification Using Social Network Analysis
While the rapid adaptation of mobile devices changes our daily life more
conveniently, the threat derived from malware is also increased. There are lots
of research to detect malware to protect mobile devices, but most of them adopt
only signature-based malware detection method that can be easily bypassed by
polymorphic and metamorphic malware. To detect malware and its variants, it is
essential to adopt behavior-based detection for efficient malware
classification. This paper presents a system that classifies malware by using
common behavioral characteristics along with malware families. We measure the
similarity between malware families with carefully chosen features commonly
appeared in the same family. With the proposed similarity measure, we can
classify malware by malware's attack behavior pattern and tactical
characteristics. Also, we apply a community detection algorithm to increase the
modularity within each malware family network aggregation. To maintain high
classification accuracy, we propose a process to derive the optimal weights of
the selected features in the proposed similarity measure. During this process,
we find out which features are significant for representing the similarity
between malware samples. Finally, we provide an intuitive graph visualization
of malware samples which is helpful to understand the distribution and likeness
of the malware networks. In the experiment, the proposed system achieved 97%
accuracy for malware classification and 95% accuracy for prediction by K-fold
cross-validation using the real malware dataset.Comment: 13 pages, 11 figures, dataset link:
http://ocslab.hksecurity.net/Datasets/andro-simnet , demo video:
https://youtu.be/JmfS-ZtCbg4 , In Proceedings of the 16th Annual Conference
on Privacy, Security and Trust (PST), 201
Experimental investigations on the characteristics of snow accretion using the EMU-320 model train
This paper presents a snow accretion test conducted in a climate wind tunnel
to investigate the icing process on a model train. The model used within this
experiment was the cleaned-up and 2/3-scaled version of EMU-320, which is a
high-speed train in Korea. The model was designed without an electronic power
source or heat source so that the wheels did not rotate and snow accretion on
the model did not occur due to heat sources. To investigate snow accretion,
four cases with different ambient temperatures were considered in the climate
wind tunnel on Rail Tec Arsenal. Before analyzing the snow accretion on the
train, the snow flux and liquid water content of snow were measured so that
they could be used as the input conditions for the simulation and to ensure the
analysis of the icing process was based on the characteristics of the snow.
Both qualitative and quantitative data were obtained, whereby photographs was
used for qualitative analysis, and the density of the snow sample and the
thickness of snow accreted on the model were used for quantitative analysis.
Based on the visual observations, it was deduced that as the ambient
temperature increased, the range of the snow accreted was broader. The
thickness of snow accreted on the model nose was the largest on the upper and
lower part at -3 oC, and on the middle part at -5 oC. Additionally, the cross
section of snow accreted was observed to be trench-like. Similar icing
processes were observed to occur on the slope of nose. Snow accreted on all
components of the bogie, and for all cases, the thickness of snow at wheel was
the largest at an arc angle of 40 to 70 o. These detailed data of experimental
conditions can be applied as an input to simulations to improve simulations of
ice conditions. Thus, they can facilitate the development of appropriate
anti-icing designs for trainsComment: 31 pages, 23 Figures, 8 Table
Vitamin D3 Supplementation Reduces the Symptoms of Upper Respiratory Tract Infection during Winter Training in Vitamin D-Insufficient Taekwondo Athletes: A Randomized Controlled Trial
Vitamin D insufficiency may be associated with increased risk of upper respiratory tract infection (URTI) in athletes. This study examined the effects of vitamin D3 supplementation on salivary immune functions and symptoms of URTI in vitamin D-insufficient taekwondo athletes. Twenty-five male taekwondo athletes, aged 19–22 years with vitamin D insufficiency [serum 25-hydroxyvitamin-D concentrations (25(OH)D, 31.3 ± 1.39 nmol/L)], participated in this study. They were randomized to receive 5000 IU/day of vitamin D3 (n = 13) or placebo capsule (n = 12) during 4 weeks of winter training. Blood samples were collected two times (pre- and post-tests) for analyzing serum 25(OH)D concentration while salivary samples were obtained three times (pre-, mid-, and post-tests) for secretory immunoglobulin A (SIgA) and lactoferrin analyses. The symptoms of URTI were reported daily during the intervention. Serum 25(OH)D concentration significantly increased by 255.6% in the vitamin D group, whereas in the placebo group it did not change (p \u3c 0.001). While the significant increase in SIgA was observed in both groups (p \u3c 0.001), elevated salivary lactoferrin level in response to winter training was found only in the placebo group (p = 0.011). The change in serum 25(OH)D concentration was negatively associated with total URTI symptoms (r = −0.435, p = 0.015). Vitamin D3 supplementation may be effective in reducing the symptoms of URTI during winter training in vitamin D-insufficient taekwondo athletes
Identification of the optimal hiit protocol for fatigue resistance in adolescent athletes: a randomized controlled trial
The combat sports athletes developed great gains in both muscular function and fatigue resistance by utilizing high-intensity interval training (HIIT). However, it has not been investigated fully whether different work-to-rest ratios of HIIT show the effectiveness on muscle function in adolescent athletes. The purpose of the study was to compare different work-to-rest ratios by applying different rest times in response to the identical work time during HIIT on muscle function in adolescent taekwondo athletes. Forty-seven adolescent male taekwondo athletes (mean age: 16.7±0.8 years) were randomly assigned to the control group (n=11) vs. three HIIT groups by work-to-rest ratios; (1) 1:2 [30s:60s] (n=12), (2) 1:4 [30s:120s] (n=12), and (3) 1:8 [30s:240s] (n=12). All groups completed 10 experimental sessions over four weeks, while the control group maintained their regular taekwondo training. Muscular functions were measured by assessing isokinetic muscle strength and endurance of the knee extensor and flexor. The participants performed three sets of twenty maximal extension and flexion contractions at 120°s-1 with a 1-min interval between the sets for fatigue resistance. Blood samples were collected to measure free-testosterone, cortisol, creatine kinase, and urea as stress-to-recovery indicators. A positive effect on improving muscle fatigue resistance was observed at the first set of assessments in the HIIT with 1:4 (Δ10.2%, p<.05) and 1:8 groups (Δ8.6%, p<.05). Additionally, the 1:4 group exhibited fatigue resistance improvement in the second set (Δ7.7%, p<.01) without any changes of stress-to-recovery indicators, while the other groups did not show any improvement. The 30s all-out work with 120s rest time, lasting over a brief 4-week period, improved participants’ fatigue resistance. A certain amount of rest time between high-intense movements is required to optimize muscle development in adolescent athletes compared with insufficient rest time
Association of factor XIII Val34Leu polymorphism and coronary artery disease: A meta-analysis
Background: Factor XIII plays an important role in the stabilization of the linkage between fibrins and in the pathophysiology of coronary artery disease (CAD). The association between factor XIII Val34Leu polymorphism and CAD risk remains controversial.
Methods: We conducted a meta-analysis of 36 studies involving 26,940 cases and 34,694 controls. Subgroup analyses were performed with division of data into disease (myocardial infarction [MI], CAD without MI), age, and sex.
Results: Factor XIII Val34Leu polymorphism was significantly associated with ove all CAD risk (odds ratio [OR] = 1.09, 95% confidence interval [CI] = 1.03–1.06, p = 0.004) and MI risk (OR = 1.15, 95% CI 1.07–1.25, p = 0.0003), but not with CAD without MI risk (OR = 1.00, 95% CI 0.87–1.15, p = 0.96). In the subgroup analysis by age and sex, there was no association between Val34Leu polymorphism and CAD.
Conclusions: This meta-analysis found that factor XIII Val34Leu polymorphism was associated with CAD risk, especially MI, but not with CAD without MI. In addition, age and sex did not affect the relationship between factor XIII Val34Leu polymorphism and CAD risk.
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