PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collections

Permanent URI for this collectionhttps://hdl.handle.net/20.500.13091/5

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Now showing 1 - 20 of 245

Citation - WoS: 9
Citation - Scopus: 11
Adrenal Tumor Segmentation Method for Mr Images
(ELSEVIER IRELAND LTD, 2018) Barstuğan, Mücahid; Ceylan, Rahime; Asoğlu, Semih; Cebeci, Hakan; Koplay, Mustafa
Background and objective: Adrenal tumors, which occur on adrenal glands, are incidentally determined. The liver, spleen, spinal cord, and kidney surround the adrenal glands. Therefore, tumors on the adrenal glands can be adherent to other organs. This is a problem in adrenal tumor segmentation. In addition, low contrast, non-standardized shape and size, homogeneity, and heterogeneity of the tumors are considered as problems in segmentation. Methods: This study proposes a computer-aided diagnosis (CAD) system to segment adrenal tumors by eliminating the above problems. The proposed hybrid method incorporates many image processing methods, which include active contour, adaptive thresholding, contrast limited adaptive histogram equalization (CLAHE), image erosion, and region growing. Results: The performance of the proposed method was assessed on 113 Magnetic Resonance (MR) images using seven metrics: sensitivity, specificity, accuracy, precision, Dice Coefficient, Jaccard Rate, and structural similarity index (SSIM). The proposed method eliminates some of the discussed problems with success rates of 74.84%, 99.99%, 99.84%, 93.49%, 82.09%, 71.24%, 99.48% for the metrics, respectively. Conclusions: This study presents a new method for adrenal tumor segmentation, and avoids some of the problems preventing accurate segmentation, especially for cyst-based tumors. (C) 2018 Elsevier B.V. All rights reserved.
Citation - WoS: 36
Citation - Scopus: 42
Removal of Pahs From Leachate Using a Combination of Chemical Precipitation and Fenton and Ozone Oxidation
(IWA PUBLISHING, 2018) Ateş, Havva; Argun, Mehmet Emin
In this study, six emerging pollutants, belonging to the polycyclic aromatic hydrocarbons (PAHs) group, found in landfill leachate were investigated for their removal by sequential treatment processes including chemical precipitation (CP), Fenton oxidation (FO) and ozone oxidation (OO). Each treatment process was run under different conditions using an experimental design program. Optimization of both CP and FO processes was designed based on the measured values of the residual chemical oxygen demand (COD) of the samples analyzed. The analysis of variance test was applied to the obtained results for determination of statistical significance of the model. Removal efficiencies of micropollutants were determined in the optimal conditions both for CP and FO processes. Samples obtained after these processes were treated with different pH and ozonation times for observing the performances of ozonation on micropollutant removal under different operating conditions. In this study, the removal of acenaphthylene, acenaphthene, fluorene, phenanthrene, fluoranthene and pyrene micropollutants was investigated. The values obtained for PAHs in leachate were determined to be above 10 ppb. In the CP process, the removal efficiencies for PAHs were ranged between 6% and 40% except for pyrene. Removal efficiencies of all micropollutants with FO were over 70% except for fluorene (55%). The removal efficiencies of the investigated micropollutants were 80-100% as a result of consecutive treatment processes including CP, FO and OO respectively.
Citation - WoS: 44
Citation - Scopus: 45
Uv/Visible Light Active Cucro2 Nanoparticle-Sno2 Nanofiber P-N Heterostructured Photocatalysts for Photocatalytic Applications
(ROYAL SOC CHEMISTRY, 2018) Dursun, Sami; Kaya, İsmail Cihan; Kalem, Volkan; Akyıldız, Hasan
CuCrO2 nanoparticle decorated SnO2 nanofiber composites have been prepared as novel p-n heterostructured semiconductor photocatalysts for the degradation of organic pollutants in wastewater. The composite structure was achieved via drop casting of various amounts of hydrothermally derived CuCrO2 nanoparticles on electrospun SnO2 nanofibers. The microstructural and morphological features of each semiconductor and the formation of p-n heterojunctions between them were characterized. In addition, the photo-response and electrochemical properties of the samples were determined. The photocatalytic activity of the heterostructured photocatalysts was investigated systematically as a function of the amount of CuCrO2 nanoparticles in the samples. Experimental results showed that the optimal decoration amount was 0.6 wt% CuCrO2 on SnO2. This composite photocatalyst displayed a 41% higher rate constant value compared to pure SnO2 nanofibers in the degradation of methylene blue dye molecules and reached 83% degradation under UV/visible light irradiation after 1 h. The increase in the photocatalytic activity was ascribed to the incorporation of Cr3+ and Cu+ cations into the SnO2 host lattice and the more effective electron-hole pair separation in the heterostructured sample. The presented data here are highly convincing in comparison to those of UV active p-n heterostructured photocatalysts reported previously in the literature. Therefore, this work opens the way to develop visible light active p-n heterostructured semiconductor photocatalysts using p-type delafossites with n-type oxides.
Citation - WoS: 31
Citation - Scopus: 34
A New Method for Automatic Counting of Ovarian Follicles on Whole Slide Histological Images Based on Convolutional Neural Network
(PERGAMON-ELSEVIER SCIENCE LTD, 2019) İnik, Özkan; Ceyhan, Ayşe; Balcıoğlu, Esra; Ülker, Erkan
The ovary is a complex endocrine organ that shows significant structural and functional changes in the female reproductive system over recurrent cycles. There are different types of follicles in the ovarian tissue. The reproductive potential of each individual depends on the numbers of these follicles. However, genetic mutations, toxins, and some specific drugs have an effect on follicles. To determine these effects, it is of great importance to count the follicles. The number of follicles in the ovary is usually counted manually by experts, which is a tedious, time-consuming and intense process. In some cases, the experts count the follicles in a subjective way due to their knowledge. In this study, for the first time, a method has been proposed for automatically counting the follicles of ovarian tissue. Our method primarily involves filter-based segmentation applied to whole slide histological images, based on a convolutional neural network (CNN). A new method is also proposed to eliminate the noise that occurs after the segmentation process and to determine the boundaries of the follicles. Finally, the follicles whose boundaries are determined are classified. To evaluate its performance, the results of the proposed method were compared with those obtained by two different experts and the results of the Faster R-CNN model. The number of follicles obtained by the proposed method was very close to the number of follicles counted by the experts. It was also found that the proposed method was much more successful than the Faster R-CNN model.
Citation - WoS: 11
Citation - Scopus: 10
An Extensive Study for Binary Characterisation of Adrenal Tumours
(SPRINGER HEIDELBERG, 2019) Koyuncu, Hasan; Ceylan, Rahime; Asoğlu, Semih; Cebeci, Hakan; Koplay, Mustafa
On adrenal glands, benign tumours generally change the hormone equilibrium, and malign tumours usually tend to spread to the nearby tissues and to the organs of the immune system. These features can give a trace about the type of adrenal tumours; however, they cannot be observed all the time. Different tumour types can be confused in terms of having a similar shape, size and intensity features on scans. To support the evaluation process, biopsy process is applied that includes injury and complication risks. In this study, we handle the binary characterisation of adrenal tumours by using dynamic computed tomography images. Concerning this, the usage of one more imaging modalities and biopsy process is wanted to be excluded. The used dataset consists of 8 subtypes of adrenal tumours, and it seemed as the worst-case scenario in which all handicaps are available against tumour classification. Histogram, grey level co-occurrence matrix and wavelet-based features are investigated to reveal the most effective one on the identification of adrenal tumours. Binary classification is proposed utilising four-promising algorithms that have proven oneself on the task of binary-medical pattern classification. For this purpose, optimised neural networks are examined using six dataset inspired by the aforementioned features, and an efficient framework is offered before the use of a biopsy. Accuracy, sensitivity, specificity, and AUC are used to evaluate the performance of classifiers. Consequently, malign/benign characterisation is performed by proposed framework, with success rates of 80.7%, 75%, 82.22% and 78.61% for the metrics, respectively.
Citation - WoS: 28
Citation - Scopus: 31
Fast Decolorization of Cationic Dyes by Nano-Scale Zero Valent Iron Immobilized in Sycamore Tree Seed Pod Fibers: Kinetics and Modelling Study
(TAYLOR & FRANCIS INC, 2019) Parlayıcı, Şerife; Pehlivan, Erol
In the present work, Sycamore (Platanus occidentalis) tree seed pod fibers (STSPF) and nano-scale zero valent iron particles (nZVI) immobilized in Sycamore tree seed pod fibers (nZVIx298;STSPF) were produced. This biosorbent has been utilized as a viable effective biosorbent in the removing of methylene blue hydrate (MB), malachite green oxalate(MG), methyl violet 2B(MV) dyes from synthetic wastewater. The biosorbents were characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy. Various parameters such as contact time, solution concentration, pH and amount of biosorbent were investigated in order to evaluate the potential of the nanomaterials immobilized on natural wastes as sorbing biomaterials for the cationic dyes. Study on sorption kinetic and the sorption isotherm was carried out and best fitting models for the rate kinetics and isotherms were suggested. Langmuir isotherm was observed to be compatible with the isotherm models. The STSPF in the raw form showed the best dye sorption capacity of 43.67 mg/g for MG, 25.32 mg/g for MV, and 126.60 mg/g for MB. The magnetic nZVIx298;STSPF showed the best dye sorption capacity 92.59 mg/g for MG, 92.59 mg/g for MV, and 140.80 mg/g for MB. The iron nanoparticles immobilized biosorbent exhibited a higher removal capacity for all dyes compared to the raw biosorbent. [GRAPHICS] .
Citation - WoS: 10
Citation - Scopus: 16
Design and Validation of Multichannel Wireless Wearable Semg System for Real-Time Training Performance Monitoring
(HINDAWI LTD, 2019) Örücü, Serkan; Selek, Murat
Monitoring of training performance and physical activity has become indispensable these days for athletes. Wireless technologies have started to be widely used in the monitoring of muscle activation, in the sport performance of athletes, and in the examination of training efficiency. The monitorability of performance simultaneously in the process of training is especially a necessity for athletes at the beginner level to carry out healthy training in sports like weightlifting and bodybuilding. For this purpose, a new system consisting of 4 channel wireless wearable SEMG circuit and analysis software has been proposed to detect dynamic muscle contractions and to be used in real-time training performance monitoring and analysis. The analysis software, the Haar wavelet filter with threshold cutting, can provide performance analysis by using the methods of moving RMS and %MVC. The validity of the data obtained from the system was investigated and compared with a biomedical system. In this comparison, 90.95% +/- 3.35 for left biceps brachii (BB) and 90.75% +/- 3.75 for right BB were obtained. The output of the power and %MVC analysis of the system was tested during the training of the participants at the gym, and the training efficiency was measured as 96.87% +/- 2.74.
Citation - WoS: 22
Citation - Scopus: 24
Rapid and Real-Time Detection of Arginine Enantiomers by Qcm Sensor Having a Calix[4]arene Receptor Bearing Asymmetric Centers
(ELSEVIER, 2019) Temel, Farabi; Erdemir, Serkan; Özçelik, Egemen; Tabakcı, Begüm; Tabakcı, Mustafa
This paper describes the sensing studies of a chiral calix[4]arene receptor (5) having (R)-2-phenylglycinol moiety for arginine enantiomers (D-/L-arginine) by using Quartz Crystal Microbalance (QCM) technique. The initial experiments have revealed that the chiral calix[4]arene 5 coated QCM (CCC-QCM) sensor showed good sensing for arginine enantiomers, such that it has exhibited higher sensing towards D-arginine than that of L-arginine. It has been determined that the sensitivity, limit of detection values of CCC-QCM sensor for the D-/L-arginine solutions as 0.024/0.023 Hz/mu M and 0.38/1.29 mu M, respectively. On the other hand, the racemic mixture studies were optimized using the response surface methodology with central composite design. Consequently, it has been demonstrated that the QCM sensor modification with a calix[4]arene receptor bearing asymmetric centers provided rapid, real-time, sensitive and effective sensing of arginine enantiomers.
Citation - WoS: 29
Citation - Scopus: 28
Selective Chiral Recognition of Alanine Enantiomers by Chiral Calix[4]arene Coated Quartz Crystal Microbalance Sensors
(SPRINGER HEIDELBERG, 2019) Temel, Farabi; Erdemir, Serkan; Tabakcı, Begüm; Akpınar, Merve; Tabakcı, Mustafa
We describe the synthesis of new chiral calix[4]arene derivatives having (R)-1-phenylethylamine, (S)-1-phenylethylamine, (R)-2-phenylglycinol, and (S)-2-phenylglycinol moieties, and chiral recognition studies for enantiomers of some selected -amino acid derivatives such as alanine, phenylalanine, serine, and tryptophan using a quartz crystal microbalance (QCM). Initial experiments indicated that the highest selective chiral recognition factor was 1.42 for alanine enantiomers. The sensitivity, limit of detection, and time constant for l-alanine were calculated as 0.028 Hz/M, 60.9 M, and 36.2 s, respectively. The results indicated that real-time, sensitive, selective, and effective chiral recognition of alanine enantiomers was achieved with a QCM sensor coated with a chiral calix[4]arene derivative having (R)-2-phenylglycinol moieties.
Citation - WoS: 15
Citation - Scopus: 20
Modified Peach Stone Shell Powder for the Removal of Cr (vi) From Aqueous Solution: Synthesis, Kinetic, Thermodynamic, and Modeling Study
(TAYLOR & FRANCIS INC, 2019) Parlayıcı, Şerife
Citric acid treated peach (Prunus persica) stone shell as an effective adsorbent were synthesized for the adsorption of Cr (VI) from aqueous solutions. The aim of this study was to predict the optimal conditions for citric acid modification of peach kernel shell (CA-PSS) the modification process and the removal of Cr (VI) ions from aqueous solutions using a batch-type model. Research of its adsorption of Cr (VI) showed that CA-PSS in conditions at 120 degrees C for 4 h and in mass ratio of peach stone shell: citric acid =1:1 had greater adsorption capacity. Cr (VI) adsorption was investigated by changing several conditions. Adsorption studies have been carried out to determine the effect of time, pH, adsorbent dosage, temperature, and initial Cr (VI) ions concentration on the adsorption capacity of Cr (VI) ions by the esterified peach stone shell. The results indicate that the Langmuir model provides a better fit for the adsorption data. The equilibrium adsorption capacity of Cr (VI) was 25.71 mg/g for CA-PSS. The adsorption kinetic process followed the pseudo-second-order kinetics. Thermodynamic parameters such as the changes in Delta G degrees, Delta H degrees, and Delta S degrees have also been estimated, and the process was found to be spontaneous.
Citation - WoS: 25
Citation - Scopus: 22
A Phenyl Glycinol Appended Calix[4]arene Film for Chiral Detection of Ascorbic Acid on Gold Surface
(ACADEMIC PRESS INC ELSEVIER SCIENCE, 2019) Akpınar, Merve; Temel, Farabi; Tabakcı, Begüm; Özçelik, Egemen; Tabakcı, Mustafa
This paper describes the synthesis of new chiral calix [4]arene derivative having (R)-2-phenylglycinol moiety (compound 6), and its chiral recognition studies for ascorbic acid (AA) enantiomers by using Quartz Crystal Microbalance (QCM). Initial experiments indicated that the outstanding selective chiral recognition (alpha) was observed as 2.61 for L-enantiomer of AA. The sensitivity (S) and the limit of detection (LOD) values for L-AA were calculated as 0.0226 Hz/mu M and 0.63 mu M, respectively. Furthermore, the sorption behavior and mechanism of AA onto compound 6 film were evaluated and the sorption data exhibited a good correlation with the Freundlich isotherm models. The maximum uptake of L-AA by the sensor was found as 5895.76 mg/g. In conclusion, chiral recognition of AA enantiomers as real-time, sensitive, selective and effective was performed by a calixarene derivative coated QCM sensor.
Citation - WoS: 68
Citation - Scopus: 75
Synthesis and Characterization of Electrospun Pva/Zn2+ Metal Composite Nanofibers for Lipase Immobilization With Effective Thermal, Ph Stabilities and Reusability
(ELSEVIER SCIENCE BV, 2019) Işık, Ceyhun; Arabacı, Gökmen; Doğaç, Yasemin İspirli; Deveci, İlyas; Teke, Mustafa
Polyvinyl alcohol (PVA)/Zn2+ electrospun nanofibers that were a kind of polymer/ionic metal composite was successfully embedded in the hybrid fibers for the first time in the literature, due to chemical interactions between PVA and Zn2+. Also, the nanofibers were used as carriers for the first time in enzyme immobilization. The nanofibers were optimized and synthesized by electrospinning technique according to the operational parameters like as PVA concentration (%), Zn2+ concentration (%), voltage (kV), needle tip-collector distance (cm) and injection speed (ml/h). The morphology and structure of the nanofibers were characterized by SEM, XRD, ATR-FTIR and TGA. Lipase was immobilized on the nanofibers by adsorption and crosslinking methods. According to immobilization results, nanofiber enhanced enzyme stability properties like as thermal stability, pH stability and reusability. Lipase immobilized nanofiber protected 90% of its activity after 14 reuses.
Citation - WoS: 35
Citation - Scopus: 37
Performance of Sio2/Ag Core/Shell Particles in Sonocatalalytic Degradation of Rhodamine B
(ELSEVIER SCIENCE BV, 2019) Deveci, İlyas; Mercimek, Bedrettin
In this study, SiO2/Ag Core/Shell nanoparticles was prepared and sonocatalytic activity of prepared catalyst was investigated by using Rhodamine B as model contaminant, at 35 kHz using ultrasonic power of 160 W within 90 min. The change in efficiency in the sonocatalytic degradation of Rhodamine B catalyzed by SiO2/Ag Core/Shell nanoparticles with respect to the initial concentration of dye, catalyst amount and temperature were firstly investigated. Optimal conditions were found as follows: catalyst amount = 15 mg/L, Temperature = 25 degrees C and initial concentration of dye = 10 ppm. Influence factors such as pH of solution, O-2 saturation of solution and the concentration of H2O2 added to the solution, on degradation efficiency in presence of catalyst, were investigated. SiO2/Ag Core/Shell nanoparticles showed higher sonocatalytic activity at pH = 7 with respect to acidic and alkaline conditions. Degradation efficiency was reached up to 67% in experiments which air pumped (0.6 L/min) through the solution with in 90 min. It was observed that the dye removal increased via increase while H2O2 concentration lower than 10 mM. Higher concentration of H2O2 than the optimal concentration had adverse effect on degradation efficiency. Our results showed that the SiO2/Ag Core/Shell nanoparticles were active catalyst for sonocatalytic degradation of dyes. Reusability of the catalyst was investigated.
Citation - WoS: 2
Citation - Scopus: 2
Chitosan-Coated Black Sesame (sesamum Indicum L.) Seed Pulp as a Novel Candidate Adsorbent for Cr(vi) Elimination
(IWA PUBLISHING, 2019) Parlayıcı, Şerife; Tuna, Kübra; Özdemir, Elif; Pehlivan, Erol
This study evaluates the application of Cr(VI) adsorption from the prepared synthetic solution by black sesame (Sesamum indicum L.) seed pulp (BSSP) and chitosan (Cts)-coated black sesame seed pulp beads (Cts-BSSP). BSSP and Cts-BSSP were used as an adsorbent without any chemical or physical treatment to remove Cr(VI) from an aqueous medium. The results indicated that the Cr(VI) removal was pH-dependent and reached an optimum at pH 2.0. It has been observed that the percentage of adsorption increased from 62% to 95% when the amount of Cts-BSSP increased from 0.0125 g to 0.0250 g. The required adsorbent amount for the maximum removal was 0.05 g and 0.1 g for Cst-BSSP and BSSP, respectively. The contact time for the adsorption was 120 min and 90 min for BSSP and Cst-BSSP, respectively. Scanning electron microscopy and Fourier transform infrared spectroscopy were used to explore the possible adsorption mechanism for Cr(VI). The equilibrium data for the BSSP and Cts-BSSP were used with the Langmuir and Freundlich adsorption isotherm models to assess the adsorption capacity and relevant mechanism. The adsorption capacity of the Cts-BSSP for Cr(VI) is relatively high compared to BSSP. The monolayer maximum adsorption capacities for Cr(VI) ions were 31.44 and 18.32 mg/g for Cts-BSSP and BSSP, respectively.
Citation - WoS: 11
Citation - Scopus: 9
Capture and Release Recyclable Dimethylaminomethyl-Calixarene Functional Cloths for Point-Of Removal of Highly Toxic Chromium Water Pollutants
(AMER CHEMICAL SOC, 2020) Bieber, Vera S.; Özçelik, Egemen; Cox, Harrison J.; Ottley, Christopher J.; Ratan, Jatinder K.; Karaman, Mustafa; Badyal, Jas Pal S.
Chromium(VI) contamination of drinking water arises from industrial activity wherever there is a lack of environmental legislation enforcement regarding the removal of such pollutants. Although it is possible to remove such harmful metal ions from drinking water through large-scale facilities, there currently exists no safe and simple way to filter chromium(VI) oxoanions at the point of use (which is potentially safer and necessary in remote locations or humanitarian scenarios). High-surface-area cloth substrates have been functionalized with calixarene molecules for the selective capture of aqueous chromium(VI) oxoanions in the presence of structurally similar anions. This is accomplished by pulsed plasmachemical deposition of a linker layer and subsequent functionalization with dimethylaminomethyl-calixarene (5,11,17,23-tetrakis [(dimethylamino)methyl]-25,26,27,28-tetrahydroxycalix[4]arene. Chromium(VI) oxoanions are captured by simply passing polluted water through the functionalized cloth, while other ions not harmful/beneficial to human health remain in the water. These cloth filters are simple to use, highly selective, and easily recyclable-thus making them attractive for point-of-use application in geographic regions lacking appropriate wastewater treatment plants or flawed environmental monitoring systems. Chromium(VI) pollutants have been successfully removed from real-world contaminated industrial wastewater streams using the dimethylaminomethyl-calixarene functionalized cloths.
Citation - WoS: 33
Citation - Scopus: 31
One Novel Calix[4]arene Based Qcm Sensor for Sensitive, Selective and High Performance-Sensing of Formaldehyde at Room Temperature
(ELSEVIER, 2020) Temel, Farabi
This work designs the synthesis of a novel amino morpholine schiff base functionalized calix[4]arene cage (SCC), its deposition onto Quartz Crystal Microbalance (QCM) crystal surface, and usage for the selective detecting of formaldehyde (HCHO). The SCC modified QCM sensor has been characterized by contact angle measurements and microscopy images. Initial experiments revealed that the frequency response decreased significantly which means that there was a good interaction between the SCC molecules and HCHO. The proposed sensor exhibited a linear response towards HCHO in different concentrations ranging from 1.85 to 9.25 ppm, having the high sensitivity (S) and low limit of detection (LOD) being 18.324 Hz/ppm and 0.67 ppm, respectively. Furthermore, the adsorption behavior and mechanism of HCHO onto the QCM sensor were investigated for this sensing system and the adsorption data exhibited a good correlation with the Freundlich and Langmuir-Freundlich adsorption models in terms of the regression coefficient. The QCM sensor showed outstanding selective performance to HCHO among %97 RH and some a number of interfering volatile organic compounds (VOCs) such as chloroform, dichloromethane, acetone, n-hexane, methanol, xylene, and ammonia. Thus, real-time, sensitive, selective and effective recognition of HCHO by the sensor can be explained some adsorption mechanisms such as size-fit concept, three-dimensional structures of molecules and interaction between moieties of the sensible film layer and analyte molecules such as hydrogen bonding interactions.
Citation - Scopus: 36
Removal of Methylene Blue Dye From Aqueous Solutions by Adsorption on Levulinic Acid-Modified Natural Shells
(Taylor and Francis Inc., 2020) Kocaman, Süheyla
This study has developed an innovative and environmentally friendly approach for the removal of methylene blue (MB) dye by natural shells (NShs) chemically modified with levulinic acid (LA). Almond shell (ASh), walnut shell (WSh), and apricot kernel shell (AKSh) were used as waste fillers. The adsorption behavior of MB onto the biosorbents was investigated with respect to parameters such as sorbent dosage (0.4–6 g/L), pH (3–10), initial dye concentration (10–500 mg/L), and temperature (25–65 °C). The biosorbents were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) analysis. The isotherm and kinetic adsorption data can be said to fit the Freundlich isotherm model and the pseudosecond-order model, respectively. The maximum adsorption capacity (qmax) of LA-modified walnut shell (LA-WSh), almond shell (LA-ASh), and apricot kernel shell (LA-AKSh) calculated by the Langmuir equation at 25 °C was 294.1, 270.2, and 180.0 mg/g, respectively. The results of thermodynamic analysis showed that adsorption was feasible, endothermic, and spontaneous. © 2020, © 2020 Taylor & Francis Group, LLC.
Citation - WoS: 22
Citation - Scopus: 22
Rapid Surface Modification of Ultrafiltration Membranes for Enhanced Antifouling Properties
(MDPI, 2020) Said, Noresah; Khoo, Ying Siew; Lau, Woei Jye; Gürsoy, Mehmet; Karaman, Mustafa; Ting, Teo Ming; Ismail, Ahmad Fauzi
In this work, several ultrafiltration (UF) membranes with enhanced antifouling properties were fabricated using a rapid and green surface modification method that was based on the plasma-enhanced chemical vapor deposition (PECVD). Two types of hydrophilic monomers-acrylic acid (AA) and 2-hydroxyethyl methacrylate (HEMA) were, respectively, deposited on the surface of a commercial UF membrane and the effects of plasma deposition time (i.e., 15 s, 30 s, 60 s, and 90 s) on the surface properties of the membrane were investigated. The modified membranes were then subjected to filtration using 2000 mg/L pepsin and bovine serum albumin (BSA) solutions as feed. Microscopic and spectroscopic analyses confirmed the successful deposition of AA and HEMA on the membrane surface and the decrease in water contact angle with increasing plasma deposition time strongly indicated the increase in surface hydrophilicity due to the considerable enrichment of the hydrophilic segment of AA and HEMA on the membrane surface. However, a prolonged plasma deposition time (>15 s) should be avoided as it led to the formation of a thicker coating layer that significantly reduced the membrane pure water flux with no significant change in the solute rejection rate. Upon 15-s plasma deposition, the AA-modified membrane recorded the pepsin and BSA rejections of 83.9% and 97.5%, respectively, while the HEMA-modified membrane rejected at least 98.5% for both pepsin and BSA. Compared to the control membrane, the AA-modified and HEMA-modified membranes also showed a lower degree of flux decline and better flux recovery rate (>90%), suggesting that the membrane antifouling properties were improved and most of the fouling was reversible and could be removed via simple water cleaning process. We demonstrated in this work that the PECVD technique is a promising surface modification method that could be employed to rapidly improve membrane surface hydrophilicity (15 s) for the enhanced protein purification process without using any organic solvent during the plasma modification process.
Citation - WoS: 96
Citation - Scopus: 120
Skin Lesion Segmentation With Improved Convolutional Neural Network
(SPRINGER, 2020) Öztürk, Şaban; Özkaya, Umut
Recently, the incidence of skin cancer has increased considerably and is seriously threatening human health. Automatic detection of this disease, where early detection is critical to human life, is quite challenging. Factors such as undesirable residues (hair, ruler markers), indistinct boundaries, variable contrast, shape differences, and color differences in the skin lesion images make automatic analysis quite difficult. To overcome these challenges, a highly effective segmentation method based on a fully convolutional network (FCN) is presented in this paper. The proposed improved FCN (iFCN) architecture is used for the segmentation of full-resolution skin lesion images without any pre- or post-processing. It is to support the residual structure of the FCN architecture with spatial information. This situation, which creates a more advanced residual system, enables more precise detection of details on the edges of the lesion, and an analysis independent of skin color can be performed. It offers two contributions: determining the center of the lesion and clarifying the edge details despite the undesirable effects. Two publicly available datasets, the IEEE International Symposium on Biomedical Imaging (ISBI) 2017 Challenge and PH2 datasets, are used to evaluate the performance of the iFCN method. The mean Jaccard index is 78.34%, the mean Dice score is 88.64%, and the mean accuracy value is 95.30% for the proposed method for the ISBI 2017 test dataset. Furthermore, the mean Jaccard index is 87.1%, the mean Dice score is 93.02%, and the mean accuracy value is 96.92% for the proposed method for the PH2 test dataset.
Citation - WoS: 18
Citation - Scopus: 19
Antibacterial Activity of Linezolid Against Gram-Negative Bacteria: Utilization of Epsilon-Poly Capped Silica Xerogel as an Activating Carrier
(MDPI, 2020) Kaya Güzel, Gülcihan; Medaglia, Serena; Candela-Noguera, Vicente; Tormo-Mas, Maria Angeles; Marcos, Maria Dolores; Aznar, Elena; Martinez-Manez, Ramon
In recent times, many approaches have been developed against drug resistant Gram-negative bacteria. However, low-cost high effective materials which could broaden the spectrum of antibiotics are still needed. In this study, enhancement of linezolid spectrum, normally active against Gram-positive bacteria, was aimed for Gram-negative bacteria growth inhibition. For this purpose, a silica xerogel prepared from a low-cost precursor is used as a drug carrier owing to the advantages of its mesoporous structure, suitable pore and particle size and ultralow density. The silica xerogel is loaded with linezolid and capped with epsilon-poly-l-lysine. The developed nano-formulation shows a marked antibacterial activity against to Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. In comparison to free linezolid and epsilon-poly-l-lysine, the material demonstrates a synergistic effect on killing for the three tested bacteria. The results show that silica xerogels can be used as a potential drug carrier and activity enhancer. This strategy could provide the improvement of antibacterial activity spectrum of antibacterial agents like linezolid and could represent a powerful alternative to overcome antibiotic resistance in a near future.

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