Image Restoration by Lifting-Based Wavelet Domain E-Median Filter

Sema Koç,Ergun Er?lebi 한국전자통신연구원 2006 ETRI Journal Vol.28 No.1

In this paper, we propose a method of applying a liftingbased wavelet domain e-median filter (LBWDEMF) for image restoration. LBWDEMF helps in reducing the number of computations. An e-median filter is a type of modified median filter that processes each pixel of the output of a standard median filter in a binary manner, keeping the output of the median filter unchanged or replacing it with the original pixel value. Binary decisionmaking is controlled by comparing the absolute difference of the median filter output and the original image to a preset threshold. In addition, the advantage of LBWDEMF is that probabilities of encountering root images are spread over sub-band images, and therefore the e-median filter is unlikely to encounter root images at an early stage of iterations and generates a better result as iteration increases. The proposed method transforms an image into the wavelet domain using lifting-based wavelet filters, then applies an e-median filter in the wavelet domain, transforms the result into the spatial domain, and finally goes through one spatial domain e-median filter to produce the final restored image. Moreover, in order to validate the effectiveness of the proposed method we compare the result obtained using the proposed method to those using a spatial domain median filter (SDMF), spatial domain e-median filter (SDEMF), and wavelet thresholding method. Experimental results show that the proposed method is superior to SDMF, SDEMF, and wavelet thresholding in terms of image restoration.

Automated Analysis Approach for the Detection of High Survivable Ransomware

( Yahye Abukar Ahmed ),( Barış Koçer ),( Bander Ali Saleh Al-rimy ) 한국인터넷정보학회 2020 KSII Transactions on Internet and Information Syst Vol.14 No.5

Ransomware is malicious software that encrypts the user-related files and data and holds them to ransom. Such attacks have become one of the serious threats to cyberspace. The avoidance techniques that ransomware employs such as obfuscation and/or packing makes it difficult to analyze such programs statically. Although many ransomware detection studies have been conducted, they are limited to a small portion of the attack's characteristics. To this end, this paper proposed a framework for the behavioral-based dynamic analysis of high survivable ransomware (HSR) with integrated valuable feature sets. Term Frequency-Inverse document frequency (TF-IDF) was employed to select the most useful features from the analyzed samples. Support Vector Machine (SVM) and Artificial Neural Network (ANN) were utilized to develop and implement a machine learning-based detection model able to recognize certain behavioral traits of high survivable ransomware attacks. Experimental evaluation indicates that the proposed framework achieved an area under the ROC curve of 0.987 and a few false positive rates 0.007. The experimental results indicate that the proposed framework can detect high survivable ransomware in the early stage accurately.

Thiol Disulfide Homeostasis in Schizophrenic Patients Using Atypical Antipsychotic Drugs

Halef Okan Dogan,Etem Erdal Ersan,Hüseyin Aydin,Serpil Erdoğan,Serpil Erşan,Murat Alişik,Sevtap Bakir,Özcan Erel,Derya Koç 대한정신약물학회 2018 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.16 No.1

Objective: Schizophrenia is a severe, debilitating mental disorder characterized by behavioral abnormalities. Although several studies have investigated the role of oxidative stress and the effects of antipsychotic drugs on oxidative markers in schizophrenia, adequate information is not available on these issues. The aim of this study is to determine the changes in oxidative status and thiol disulfide homeostasis in schizophrenic patients using atypical antipsychotic drugs. Methods: Thirteen schizophrenic patients using atypical antipsychotic drugs and 30 healthy controls were included this study. The concentrations of total oxidant status (TOS), total antioxidant status (TAS), native thiol, total thiol, and disulfide levels were determined in the study population. Results: The TAS (p=0.001), total thiol, and native thiol levels (p<0.001) were higher in the patients compared to the controls, whereas the TOS and disulfide levels were lower in the patients than in the controls (p<0.001). Conclusion: These results may suggest that atypical antipsychotic drugs have a useful therapeutic effect by reducing oxidative stress via the inhibition of the formation of disulfide bonds. The study population number was one of the limitations of this study. Therefore, further studies are needed to establish the association between thiol disulfide homeostasis in schizophrenic patients using atypical antipsychotic drugs

The Vasodilator Effect of a Cream Containing 10% Menthol and 15% Methyl Salicylate on Random- Pattern Skin Flaps in Rats

Utku Can Dölen,Nezih Sungur,Gökhan Koca,Onur Ertunç,Ayşe Tülay Bağcı Bosi,Uğur Koçer,Meliha Korkmaz 대한성형외과학회 2015 Archives of Plastic Surgery Vol.42 No.6

Background It is still difficult to prevent partial or full-thickness flap necrosis. In this study, the effects of a cream containing menthol and methyl salicylate on the viability of randompattern skin flaps were studied. Methods Forty female Sprague-Dawley rats were divided into two equal groups. Caudally based dorsal random-pattern skin flaps were elevated, including the panniculus carnosus. In the study group, 1.5 mL of a cream containing menthol and methyl salicylate was applied to the skin of the flap, and saline solution (0.9%) was used in the control group. Upon completion of the experiment, flap necrosis was analyzed with imaging software and radionuclide scintigraphy. Histopathological measurements were made of the percentage of viable flaps, the number of vessels, and the width of the panniculus carnosus muscle. Results According to the photographic analysis, the mean viable flap surface area in the study group was larger than that in the control group (P=0.004). According to the scintigrams, no change in radioactivity uptake was seen in the study group (P>0.05). However, a significant decrease was observed in the control group (P=0.006). No statistically significant differences were observed between the groups in terms of the percentage of viable flaps, the number of vessels, or the width of the panniculus carnosus muscle (P>0.05). Conclusions Based on these results, it is certain that the cream did not reduce the viability of the flaps. Due to its vasodilatory effect, it can be used as a component of the dressing in reconstructive operations where skin perfusion is compromised.

Barbed sutures versus conventional tenorrhaphy in flexor tendon repair: An ex vivo biomechanical analysis

Özlem Çolak Aslan,Yüksel Kankaya,Nezih Sungur,Kadri Özer,Koray Gürsoy,Kemal Şerbetçi,Uğur Koçer 대한성형외과학회 2019 Archives of Plastic Surgery Vol.46 No.3

Background The management of flexor tendon injuries has evolved in recent years through industrial improvements in suture materials, refinements of repair methods, and early rehabilitation protocols. However, there is no consensus on the ideal suture material and technique. This study was conducted to compare the tensile strength, repair time, and characteristics of 4-strand cruciate, modified Kessler, and 4-strand horizontal intrafiber barbed sutures for flexor tenorrhaphy with a 12-mm suture purchase length in an animal model. Methods The right third deep flexors of 60 adult Leghorn chicken feet were isolated and repaired with a 12-mm suture purchase length. The tendons were randomly assigned to three groups of equal number (n=20 each). Groups 1 and 2 received 4-strand cruciate and modified Kessler repair with conventional suture materials, respectively. A 4-strand horizontal intrafiber barbed suture technique was used in group 3. The repaired tendons were biomechanically tested for tensile strength, 2-mm gap resistance, and mode of failure. Repair times were also recorded. Results The maximum tensile strength until failure was 44.6±4.3 N in group 1, 35.7±5.2 N in group 2, and 56.7±17.3 N in group 3. The barbed sutures were superior to the other sutures in terms of the load needed for 2-mm gap formation (P<0.05). Furthermore, the barbed sutures showed the shortest repair time (P<0.05). Conclusions This study found that 4-strand horizontal intrafiber barbed suture repair with a 12-mm purchase length in a chicken flexor tendon injury model showed promising biomechanical properties and took less time to perform than other options.

Nozzle-based precision patterning with micro-/nano fluidics integrated cantilevers

Juhee Ko,Nada Ben Fredj,Rafita Erli Adhawiyah,이정철 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.2

As the requirements of micro-/nano printing technologies are continuously increasing, direct writing technologies on a submicron scale are drawing attention. One of the promising methods is a nozzle-based precision patterning with atomic force microscopy (AFM), which has the advantages of high position controllability including nozzle-to-substrate distance feedback under a nanometer scale. It uses a fluidic channel and a dispensing nozzle integrated with a cantilever structure for deflection monitoring. In this paper, we introduce micro/nanofluidics integrated cantilevers for nozzle-based precision patterning in several considerations: 1) numerous fabrication strategies for nozzle-integrated fluidic cantilevers; 2) methods for liquid transport; 3) methods for pattern formation; and 4) applications with various printing materials.

Efficient Liposomal Nanocarrier-mediated Oligodeoxynucleotide Delivery Involving Dual Use of a Cell-Penetrating Peptide as a Packaging and Intracellular Delivery Agent

Saw, Phei Er,Ko, Young Tag,Jon, Sangyong WILEY-VCH Verlag 2010 Macromolecular Rapid Communications Vol.31 No.13

<P>The effective use of oligonucleotide therapeutics, such as antisense oligodeoxynucleotides (ODNs) and small interfering RNAs (siRNAs), requires efficient delivery systems capable of intracellular penetration. Cell-penetrating peptides (CPPs), including arginine-rich peptides, have been extensively studied as tools for enhancing intracellular uptake efficiency of various bioactive molecules, including nanoparticles and liposomes. CPPs also have an ability to form tight complexes with nucleic acids, such as ODNs and siRNAs, making CPPs effective as packaging agents. Here, we constructed a CPP-modified liposome loaded with complexes of nona-arginine (9R) and NF-κB decoy ODNs, and evaluated intracellular uptake and anticancer activity in vitro. We found that 9R/ODN complexes were efficiently loaded into liposomes that were effectively internalized into U87MG glioblastoma cells and sensitized cells to the effects of paclitaxel. To the best of our knowledge, this is the first report describing the dual use of 9R CPP as a cell penetrating and a complexing agent within a single nanoparticle.</P><P> <img src='wiley_img_2010/10221336-2010-31-13-MARC200900861-gra001.gif' alt='wiley_img_2010/10221336-2010-31-13-MARC200900861-gra001'> </P> <B>Graphic Abstract</B> <P>A novel liposomal nanocarrier system composing oligoarginine (nonaarginine) as both complexation reagent and as cell penetrating peptide is presented. Nonaarginine, when complexed to oligonucleotide (ODN), greatly increase the encapsulation efficiency of ODN into the liposome (i.e., almost 100% encapsulation). When nonaargine is conjugated to the liposome, it functions as cell penetrating peptide that greatly enhances the uptake of our liposomal formulation in vitro. This 9R-LS holds great promise for a myriad of applications including higher loading of gene or drugs, enhanced cell transfection efficacy and can simultaneously used for tumor-specific targeted delivery in vivo. <img src='wiley_img_2010/10221336-2010-31-13-MARC200900861-content.gif' alt='wiley_img_2010/10221336-2010-31-13-MARC200900861-content'> </P>