A NOTE ON INEXTENSIBLE FLOWS OF CURVES WITH FERMI-WALKER DERIVATIVE IN GALILEAN SPACE G₃

( Hülya Güun Bozok ),( Îpek Nîzamettîn Sertkol ) 호남수학회 2020 호남수학학술지 Vol.42 No.4

In this paper, Fermi-Walker derivative for inextensible flows of curves are researched in 3-dimensional Galilean space G₃. Firstly using Frenet and Darboux frame with the help of Fermi- Walker derivative a new approach for these ows are expressed, then some results are obtained for these flows to be Fermi-Walker transported in G₃.

Different MAP Conditions to Improve the Shelf Life of Sea Bass

Hülya Turan,Demet Kocatepe 한국식품과학회 2013 Food Science and Biotechnology Vol.22 No.6

Shelf life of cultured sea bass packaged in air,vacuum, and gas mixture packages stored for 40 days at2.90±0.02oC was compared. The gas mixtures used containedCO2, O2, and N2 at difference percentages (M1: 75% CO2/25% N2; M2: 60% CO2/40% N2; M3: 30% O2/30% CO2/40% N2). Sensory and physical parameters, chemicalchanges, and microbiological counts were monitoredduring storage. Storage with a gas mix including 75 and60% CO2 was more effective than vacuum processing andpackaging with a gas mix that included oxygen. Vacuumwas the most effective method for preventing lipidoxidation. The optimum method for sea bass in view of allanalysis results was modified atmosphere packaging(MAP) and the most suitable gas mix ratio was 75% CO2/25% N2. The best days for consumption of sea basspackaged with air, MAP (M1, M2, and M3), and vacuumwere 4th, 28th, 28th, 16th, and 20th days, respectively.

Differential Effects of Pentoxifylline on Learning and Memory Impairment Induced by Hypoxic-ischemic Brain Injury in Rats

Hülya Halis,Soner Bitiktaş,Osman Baştuğ,Burak Tan,Şehrazat Kavraal,Tamer Güneş,Cem Süer 대한정신약물학회 2019 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.17 No.3

Objective: Hypoxic-ischemic (HI) brain injury in the human perinatal period often leads to significant long-term neurobehavioral dysfunction in the cognitive and sensory-motor domains. Using a neonatal HI injury model (unilateral carotid ligation followed by hypoxia) in postnatal day seven rats, the present study investigated the long-term effects of HI and potential behavioral protective effect of pentoxifylline. Methods: Seven-day-old rats underwent right carotid ligation, followed by hypoxia (FiO2 = 0.08). Rats received pentoxifylline immediately after and again 2 hours after hypoxia (two doses, 60‒100 mg/kg/dose), or serum physiologic. Another set of seven-day-old rats was included to sham group exposed to surgical stress but not ligated. These rats were tested for spatial learning and memory on the simple place task in the Morris water maze from postnatal days 77 to 85. Results: HI rats displayed significant tissue loss in the right hippocampus, as well as severe spatial memory deficits. Low-dose treatment with pentoxifylline resulted in significant protection against both HI-induced hippocampus tissue losses and spatial memory impairments. Beneficial effects are, however, negated if pentoxifylline is administered at high dose. Conclusion: These findings indicate that unilateral HI brain injury in a neonatal rodent model is associated with cognitive deficits, and that low dose pentoxifylline treatment is protective against spatial memory impairment

Evaluation of Antioxidant and Antimicrobial Potential of Strawberry Tree (Arbutus Unedo L.) Leaf

Hakime Hülya Orak,Hülya Yagar,Sebnem Selen Isbilir,Ahmet Şükrü Demirci,Tuncay Gümüş,Neslihan Ekinci 한국식품과학회 2011 Food Science and Biotechnology Vol.20 No.5

In present study, antioxidant and antimicrobial activities of strawberry tree (Arbutus unedo L.) leaves were investigated. Antioxidant activity was determined by methods of DPPH scavenging, β-carotene bleaching,reducing power, metal chelating, superoxide anion scavenging, and hydrogen peroxide scavenging activity. Total phenolic content were determined to be 197.16±1.43mg GAE/g extract in aqueous extract. The EC_50 value of methanolic extracts was found to be 0.423 mg/mL. The extracts of leaves showed nearly 1/4 metal chelating capacity of standard EDTA, high reducing power,superoxide anion scavenging, and hydrogen peroxide scavenging activities. While the strawberry tree leaves exhibited antibacterial activity against Staphylococcus aureus, there was no inhibitory effect against Escherichia coli and Salmonella enteritidis. The strawberry tree leaves exhibited antifungal effect against 2 aflatoxigenic molds namely Aspergillus parasiticus NRRL 2999 and NRRL 465. These results suggest that the strawberry tree leaves may be used as an antioxidant source for pharmaceutical application, nutraceutical and functional food industries.

Tribological properties and studies in SBF of Ta2O5/TiN/TiO2 monolayer and bilayer coatings on biomedical Ti6Al4V alloy

Melis Yurddaskal,Hülya Durmuş 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.5

In this study, Ta 2 O 5 , TiN, and TiO 2 are coated with magnetron sputtering method as monolayer and bilayer on Ti6Al4V alloy used in biomedical applications. The deposited coatings are characterized, and their mechanical properties are determined by nanoindentation tests. As a result of the pin-on disc wear test performed in dry environment and room temperature, in vitro corrosion test was applied to the samples with high wear resistance, and the information about the tribological properties was obtained. Experimental results show that the existence of the intermediate layer has also significant effect on the corrosion resistance of the coatings. The biocompatibility of the Ta 2 O 5 /TiO 2 coating was examined by keeping it in simulated body fluid (SBF) due to its noticeable wear and corrosion resistance properties, the growth of apatite, which is described as an indicator of biocompatibility, occurred on the sample surface after 7 day.

Transportation Mode Choice and International Fragmentation of Production: Evidence from a Developing Country

Türkcan Kemal,Saygılı Hülya 한국국제경제학회 2021 International Economic Journal Vol.35 No.1

The objective of this study is to analyze the effects of fragmentation of production measured by the parts and components trade on the choice of transportation mode including air, sea and road. The paper attempts to account for the advantages and disadvantages of alternative transportation modes in short-, medium- and long-distance trade. Using a detailed data set (Harmonized System12-digit product level statistics for the period 2006–2014 and 143 countries) of Turkey’s machinery exports, we show that fragmentation of production plays a significant role in the selection of the transportation mode. In particular, road transportation with good infrastructure is a significant trade facilitating mode of transportation for nearby trade partners when trade involves P&C and bulky products.

Effects of pretreatments on seed dormancy and germination in endemic Uludağ flax (Linum olympicum Boiss.) (Linaceae)

Serap Kırmızı,Gürcan Güleryüz,Hülya Arslan 한국원예학회 2018 Horticulture, Environment, and Biotechnology Vol.59 No.5

Linum olympicum Boiss. (Linaceae) is an endemic species to Turkey, and has both medicinal and ornamental properties. In this study, we investigated the effects of GA3 and cold stratification (1 or 4 months) on the germination and mean germination time in relation to breaking dormancy in this species under darkness (20 °C) and light (20/10 °C, 12/12 h) conditions. Seeds were collected from specimens that spread on limestone or granite screes, ledges of rocky or turfy slopes, and hilltops of the alpine belt from Uludağ Mt. (Bursa, Turkey, 2200–2300 m). We show that a combination of hormone and cold stratification treatments promoted seed germination under darkness and light conditions. Non-stratified seeds germinated to 73% following 1000 mg L−1 GA3 treatment and also it was 83% after 1 month cold stratification. After 4 months of cold stratification treatment, 10% and 53.3% of seeds successfully germinated after incubation in light and dark conditions, respectively. Hormone and cold stratification treatments also reduced mean germination time. Our results revealed that seeds of L. olympicum have physiological dormancy and require prolonged time for cold stratification and darkness for germination, rather than responding to the photoperiod. Germination requirements of L. olympicum have not been studied previously, and the data obtained could be used for the ex situ protection of this alpine species.

Radioprotective role of amifostine on osteointegration of titanium implants in the tibia of rats

Nevra Aydemir Celep,Hülya Kara,Elif Erbaş,Elif Doğan 대한수의학회 2023 Journal of Veterinary Science Vol.24 No.3

Background: Titanium is the most widely used metal for bone integration, especially for cancer patients receiving ionizing radiation. This study aimed to investigate the amifostine administration that would reduce the effects of radiation on bone healing and osseointegration in rat models. Objectives: It is aimed that the application of amifostine in rats receiving radiotherapy treatment will reduce the negative effects of ionizing radiation on the bone. Methods: Thirty-five adult male Wistar rats were randomly divided into one healthy and four experimental groups. In three consecutive days, two experimental groups of rats (AMFRT-IMP and RT-IMP) were exposed to radiation (15 Gy/3 fractions of 5 Gy each). Then the titanium implants were inserted into the left tibia. Before the radiotherapy process, a 200 mg/kg dose of amifostine (AMF) was administered to the rats in the AMF-IMP and AMF-RTIMP groups. Twenty-eight days after the screw implant, all rats were sacrificed, and their blood samples and tibia bones were collected for analysis. Results: The results indicated an accelerated bone formation and a more rapid healing process in the screw implants in the AMF-IMP, AMF-RT-IMP, and AMF-RT groups than in the RT-IMP group. Also, bone-implant contact area measurement and inflammation decreased with amifostine treatment in the implants subjected to irradiation (p < 0.05). Conclusions: The results obtained in the present study suggested that amifostine prevents the losses of bone minerals, bone integrity, and implant position from ionizing-radiation when given before exposure.

An Investigation into Breastfeeding Characteristics of Mothers Attending Childbirth Education Classes

Samiye Mete,Kerziban Yenal,Hülya Okumus 한국간호과학회 2010 Asian Nursing Research Vol.4 No.4

Purpose This paper is a report of a study of the effects of breastfeeding education on the breastfeeding success and breastfeeding characteristics of mothers in a Turkish context. Methods The research was designed as quasi-experimental. The sample consisted of 93 mothers who participated in (n = 46) and did not participate in childbirth education classes (n = 47). The date was collected between 2005 and 2007. The childbirth education class comprised 16 hours in total. Two hours of this class involved breastfeeding education. The course was carried out with the principles of adult education principles. Data on mothers’ breastfeeding were collected in the sixth week postpartum. Results The majority of the mothers (63.4%) were university graduates. No difference was found between breastfeeding frequency in the control and experimental groups and starting supplemental food. It was found that 80.4% of the women in the experimental group breastfed in line with the techniques. This rate was found to be 48.9% in the control group. It was documented that the first breastfeeding times were earlier in the experimental group, their babies slept longer after being fed, their perceived spouse support was higher, and had even higher perceived breastfeeding success. Conclusions On the basis of the study results it could be argued that attending childbirth preparation class with the husband has a positive effect over breastfeeding. Childbirth education classes will greatly contribute to the health of the society by affecting breastfeeding positively. [Asian Nursing Research 2010;4(4):216–226]

The renoprotective effects of mannitol and udenafil in renal ischemia-reperfusion injury model

Yusuf Özlülerden,Cihan Toktaş,Hülya Aybek,Vural Küçükatay,Nilay Şen Türk,Ali Ersin Zumrutbas 대한비뇨의학회 2017 Investigative and Clinical Urology Vol.58 No.4

Purpose: The aim of this study was to investigate and compare the effects of udenafil and mannitol in an experimental renal ischemia-reperfusion (I/R) injury model. Materials and Methods: A total of 64 female Wister Albino rats were used. Right nephrectomy was performed in all groups. In the control group; I/R injury was not performed. In the I/R group; left renal pedicle was clamped for 45 minutes and then underwent 60 minutes and 24 hours of reperfusion. In the mannitol group; 1 mL 20% mannitol was given intravenously 15 minutes before clamping. In the udenafil group; 10-mg/kg udenafil was given orally 1 hour before clamping. Creatinine (Cr), blood urea nitrogen (BUN), Cr clearance, malondialdehyde, neutrophil gelatinase associated lipocalin (NGAL), histological examination and DNA damage (Comet Assay method) levels were compared in tissue, serum and urine samples. Results: Udenafil had a better protective effect than mannitol according to biochemical parameters (Cr, BUN, Cr clearance, and NGAL levels) and histopathological findings when compared with the I/R group. In the Comet sampling analysis no significant difference was detected. Conclusions: Udenafil has a better renoprotective effect than mannitol against I/R injury and this effect supports more functional improvements. Further clinical trials are needed to demonstrate those effects and clinical utility of udenafil for that purpose in humans.