Bulunan: 10 Adet 0.001 sn
Koleksiyon [19]
Tam Metin [2]
Yayın Türü [1]
Yazar [20]
Konu Başlıkları [20]
Yayıncı [10]
Yayın Dili [1]
Dergi Adı [10]
Solid phase microextraction method using a novel polystyrene oleic acid imidazole polymer in micropipette tip of syringe system for speciation and determination of antimony in environmental and food samples

Panhwar, Abdul Haleem | Tüzen, Mustafa | Hazer, Baki | Kazi, Tasneem Gul

Article | 2018 | Talanta184 , pp.115 - 121

A simple, rapid and sensitive solid phase microextraction method was used for the speciation of inorganic antimony (Sb) by using a novel synthesized polymeric material in micropipette tip of syringe system. In present methodology, the specie of Sb (III) made hydrophobic complex with diethyl dithiocarbamate (DDTC) at pH 5.5 and subsequently adsorbed on polystyrene oleic acid imidazole polymer (POIP), whereas Sb(V) did not made complex and adsorbed on the polymer, remained in aqueous solutions. The strategy of multivariate was carried out to screen out the different variables and assessed the optimum values of their experimental value . . .s for the extraction efficiency of analyte. Then the analyte was sorbed on the polymer in micropipette tip of syringe system was quantitatively eluted by different types of acids at different levels for 2–6 aspirating/dispensing cycles. The extracted Sb(III) ions with modifiers were directed into the graphite furnace atomic absorption spectrometry for analysis. The limit of detection (LOD), limit of quantification (LOQ) and preconcentration factor (PF) for Sb(III) was found to be 6 ng L-1, 20 ng L-1 and 100. The RSD value was found to be 4.2%. The standard addition method and certified reference materials were checked for accuracy and validity of method. The developed method was effectively applied for the determination of total and inorganic species of Sb(III) and Sb(V) in different types of water samples, whereas only total Sb was determined in acid digested soil, Tuna fish, rice, spinach, black tea, mixed fruit juice and ice tea samples. © 2018 Elsevier B.V Daha fazlası Daha az

Emirati women's experience of job satisfaction: Comparative effects of intrinsic and extrinsic

Seydahmet, Ercan

Article | 2018 | SOUTH AFRICAN JOURNAL OF BUSINESS MANAGEMENT49 ( 1 ) , pp.115 - 121

Living and working in a patriarchal culture that encourages modesty, female Emirati employees might face unique challenges such as a male-dominated work environment, higher emotional labour and lack of role models to follow. These challenges potentially shape Emirati women's job-related attitudes and values in a way distinct from that of Western women. Thus, rather than relying on the results of studies conducted in Western countries, researchers should collect data from Emirati women to gain a more accurate understanding of their job attitudes. Consequently, this study examines the effects of some intrinsic and extrinsic factors on . . . Emirati women's job satisfaction. The factors include pay, promotion opportunities, job security, job difficulty, job content quality and interpersonal relations. The results of a hierarchical regression analysis based on data obtained from 364 female Emirati employees indicate that pay and promotion opportunities do not have significant effects, whereas job security, job content quality and interpersonal relations have significant positive effects, and job difficulty has a significant negative effect on Emirati women's job satisfaction. The results further indicate that intrinsic factors explained 10% of variance in job satisfaction above and beyond the extrinsic factors and promotion opportunities. The article discussed the possible meaning of these findings in the context of working in a male-dominated work environment and living in a culture that encourages and values modesty Daha fazlası Daha az

Dobrava hantavirus variants found in Apodemus flavicollis mice in Kırklareli Province, Turkey

Polat, Ceylan | Sironen, Tarja | Plyusnina, Angelina | Karataş, Ahmet | Sözen, Mustafa | Matur, Ferhat | Vapalahti, Olli | Plyusnin, Alexander | Öktem, Mehmet Ali

Article | 2018 | Journal of Medical Virology90 ( 5 ) , pp.810 - 818

Hantaviruses infect humans via inhalation of viral particles within secretions of infected rodents or rarely through direct contact with infected rodents. Determining the prevalence of hantavirus infections among rodent populations is of vital importance to obtain information on hantavirus-related cases and to predict possible outbreaks. We hypothesized that DOBV strains circulating in the Thrace Region in Turkey would be related to other Balkan DOBV strains. In this study, hantavirus infections in the rodent population of the Kırklareli-İğneada Region (north-western Turkey, near the Bulgarian border) were investigated. This region . . .is of particular importance, as it is located in the south-eastern margin of the European continent and was used as an entrance point of Asian faunal elements into Europe. DOBV infection was detected in eight of 73 rodents; all were of the Apodemus flavicollis species. Partial sequences of the viral S-, M-, and L-genome segments were recovered and compared with previously reported DOBV sequences. The newly characterized Turkish strains were similar to other DOBV variants. Silent nucleotide mutations were dominant. The hantavirus prevalence in the İğneada region was similar to what has been reported in Greece and Bulgaria. For the first time, the M-segment sequences of DOBV from Turkey were recovered and genetic data of hantaviruses from Thrace region of Turkey were obtained. © 2018 Wiley Periodicals, Inc Daha fazlası Daha az

Callus production and analysis of some secondary metabolites in globularia trichosantha subsp trichosantha

Çölgeçen, Hatice | Atar, Havva | Toker, Gülnur | Akgül, Gencay

Article | 2018 | TURKISH JOURNAL OF BOTANY42 ( 5 ) , pp.810 - 818

This study describes the production of calli from Globularia trichosantha subsp. trichosantha and the quantitative determination of catalpol, aucubin, and verbascoside in the calli and the plant by HPLC. The seeds of the plant were sterilized and germinated in Murashige and Skoog (MS) medium without in vitro plant growth regulator. Hypocotyl, cotyledon, first leaf, epicotyl, apical meristem, and root explants were taken from the 30-day-old aseptic seedlings germinated in vitro. Explants were then transferred to MS media for callus production together with varying concentrations of plant growth regulators. The best callus production . . .occurred in the media containing 6 mg L-1 IAA and 0.2 mg L-1 2,4-D + 0.1 mg L-1 BAP. The highest catalpol, aucubin, and verbascoside contents were determined in the roots (1.277 mg kg(-1)), stem (0.775 mg kg(-1)), and roots (0.290 mg kg(-1)), respectively. The study is important in the sense that, 1) it is the first tissue culture study on G. trichosantha subsp. trichosantha that provides basic information for callus production; 2) that catalpol, aucubin, and verbascoside were quantitatively determined in calli and plant for the first time; and 3) all the secondary metabolites studied here were produced in the callus culture in a quantity that is approximately 7 times higher than the amount that naturally occurs in the plant Daha fazlası Daha az

Synthesis and characterization of poly(Ɛ-caprolactone-co-ethylene glycol) star-type amphiphilic copolymers by “click” chemistry and ring-opening polymerization.

Öztürk, Temel | Kılıçlıoğlu, Ali | Savaş, Bedrettin | Hazer, Baki

Article | 2018 | Journal of Macromolecular Science, Part A: Pure and Applied Chemistry55 ( 8 ) , pp.588 - 594

The synthesis of poly(?-caprolactone-co-ethylene glycol) AAB star-type amphiphilic copolymers were carried out by use of a “click” chemistry reaction to block propargyl polyethylene glycol (propargyl-PEG) to terminally azide poly(?-caprolactone) (PCL-N3). For this purpose, propargyl-PEG was synthesized by the reaction of PEGs (3000 Da, 2000 Da, 1500 Da, and 1000 Da) and propargyl chloride. Terminally chloride poly(?-caprolactone) (PCL-Cl) was carried out by means of ring-opening polymerization (ROP) of ?-caprolactone (CL) and 3-chloro-1,2-propanediol. Synthesis of PCL-N3 was obtained by the chemical interaction of PCL-Cl and sodium . . .azide. By reacting propargyl-PEG and PCL-N3, the star-type amphiphilic copolymers were obtained. The characterization of products was accomplished by using multiple instruments including 1H-NMR, FT-IR, GPC, TGA, contact angles, and elemental analysis techniques. © 2018, © 2018 Taylor & Francis Group, LLC Daha fazlası Daha az

Solid-Phase Microextraction and Determination of Tin Species in Beverages and Food Samples by Using Poly (epsilon-Caprolactone-b-4-Vinyl Benzyl-g-Dimethyl Amino Ethyl Methacrylate) Polymer in Syringe System: a Multivariate Study

Zounr, Rizwan Ali | Tüzen, Mustafa | Hazer, Baki | Khuhawar, Muhammad Yar

Article | 2018 | FOOD ANALYTICAL METHODS11 ( 9 ) , pp.2538 - 2546

A new solid-phase microextraction (SP mu E) procedure has been developed for separation and preconcentration of Sn ions by using graphite furnace atomic absorption spectrometry (GFAAS). This technique is based on the complexation of Sn(IV) ions with 1-(2-pyridylazo)-2-naphthol (PAN). The poly (epsilon-caprolactone-b-4-vinyl benzyl-g-dimethyl amino ethyl methacrylate) polymer (PCL vacr) was used as an adsorbent, and it was loaded in micropipette tip of syringe system. Sn(IV) ions were adsorbed on polymer at pH 6. Different experimental conditions were optimized such as pH, amount of complexing agent, and amount of adsorbent. The dete . . .ction limit (LOD), limit of quantification, preconcentration factor (PF), and relative standard deviation (RSD) were found as 4.5 ng L-1, 13.5 ng L-1, 100, and 3.3%, respectively. Certified reference materials were used to confirm the accuracy of the investigated procedure, and the procedure was successfully practiced for determination of entire concentration of tin within beverages and different food samples Daha fazlası Daha az

Fungal inhibition and chemical characterization of wood treated with novel polystyrene-soybean oil copolymer containing silver nanoparticles

Can, Ahmet | Sivrikaya, Hüseyin | Hazer, Baki

Article | 2018 | International Biodeterioration and Biodegradation133 , pp.210 - 215

In this study, Scots pine (Pinus sylvestris L.) samples were impregnated with autoxidized soybean oil polymer containing Ag nanoparticles (Agsbox) and polystyrene-soybean oil copolymer (AgPSsb) in order to inhibit white-rot fungus (Trametes versicolor). Chemical changes of the impregnated specimens were characterized by FTIR techniques. The higher concentration of nano preservative resulted in higher weight percent gain (WPG) in the impregnated samples. The samples impregnated with 1.5% of Agsbox, had the highest WPG (2.98%). The silver nanocomposite-impregnated wood specimens improved the anti-fungal properties. In addition, treatm . . .ent with 0.4% AgPSsb resulted in the lowest moisture content (23.4%) after decay tests. In the samples, the lowest weight loss (0.87%) due to fungal decay was observed with the use of 0.4 wt% of AgPSsb. Mass losses of Agsbox impregnated specimens at 1.5% and 0.04% were 2.86% and 4.61% respectively. The FTIR spectra of the specimens impregnated with the nanocomposites showed the impregnated components at the peaks of 2910 cm-1 and 1714 cm-1 in particular. © 2018 Elsevier Lt Daha fazlası Daha az

Enhanced antitumor activity of epigallocatechin gallate-conjugated dual-drug-loaded polystyrene-polysoyaoil-diethanol amine nanoparticles for breast cancer therapy

Karahaliloğlu, Zeynep | Kılıçay, Ebru | Alpaslan, Pınar | Hazer, Baki | Denkbaş, Emir Baki

Article | 2018 | JOURNAL OF BIOACTIVE AND COMPATIBLE POLYMERS33 ( 1 ) , pp.38 - 62

The development of novel combination anticancer drug delivery systems is an important step to improve the effectiveness of anticancer treatment in metastatic breast cancer and to overcome increased toxicity of the currently used combination treatments. The aim of this study was to assess efficient targeting, therapeutic efficacy, and bioavailability of a combination of drugs (curcumin and -tocopheryl succinate) loaded polystyrene-polysoyaoil-diethanol amine nanoparticles. Polystyrene-polysoyaoil-diethanol amine nanoparticles encapsulating two drugs, individually or in combination, were prepared by double-emulsion solvent evaporation . . . method, resulting in particle size smaller than 250nm with a surface negative charge between -30 and -40mV. Entrapment efficiency of curcumin and -tocopheryl succinate in the epigallocatechin gallate-conjugated dual-drug-loaded nanoparticles was found to be 68% and 80%, respectively. The release kinetics of curcumin and -tocopheryl succinate from the nanoparticles exhibited a gradual and continuous profile followed by an initial burst behavior with a release over 20days in vitro. Next, we have investigated the anticancer activity of nanoparticles encapsulating both the drugs and individually drug in human breast cancer cells (MDA-MB-231) using double-staining-based cell death analysis, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assessment of cytotoxicity and flow cytometer. In vitro cytotoxicity studies revealed that epigallocatechin gallate--tocopheryl succinate/curcumin-polystyrene-polysoyaoil-diethanol amine nanoparticles are more potent than the corresponding -tocopheryl succinate/curcumin-polystyrene-polysoyaoil-diethanol amine nanoparticles and their single-drug-loaded forms and show a synergistic and breast tumor targeting function. Thus, here, we propose epigallocatechin gallate-conjugated curcumin and -tocopheryl succinate-loaded polystyrene-polysoyaoil-diethanol amine nanoparticles which effectively inhibit tumor growth and reduce toxicity compared to single-drug chemotherapy Daha fazlası Daha az

Soybean oil based polylactic acid membranes: Synthesis and degradation characteristics

Aydın Tığlı, R. Seda | Akyol, Elvan | Hazer, Baki

Article | 2018 | Journal of Polymers and the Environment26 ( 3 ) , pp.1262 - 1271

Controlling the degradation parameters is one of the main challenges of preparing appropriate biomaterials for biomedical applications. In this study, the effect of soybean oil inclusion on hydrolytic degradation of polylactic acid (PLA) was investigated both in vitro and in vivo. PLA/oil membranes were prepared by using polymeric soybean oil (PSO), epoxidized soybean oil and soybean oil (SOYA) with their varied concentrations. Degradation of membranes was performed in vitro for 8 weeks period and in vivo for 4 weeks period. Weight loss, changes in molecular weight, thermal properties and morphological changes were studied during de . . .gradation. SOYA blended PLA membranes show the lowest degradation rates by bulk degradation after 4 weeks in vitro, followed by surface erosion for the first week. Approximately twofold high percentage weight losses of all membranes were obtained after 4 weeks of degradation in vivo in comparison with in vitro data. The significant weight loss, molecular weight loss and thermal property change for PSO blended membranes were determined during in vivo degradation which highlights the increase of degradation rate by bulk degradation. Drastic morphological changes were observed on surface of degraded membranes in vivo with large pores, cracks, fissures and large cavities. © 2017, Springer Science+Business Media New York Daha fazlası Daha az

Soviet Russia’s Foreign Affairs with Turkey in 1923 Reports of Ambassador Surits

Somel, Gözde

Article | 2018 | Journal of Balkan and Near Eastern Studies , pp.1262 - 1271

The history of Turkey–Soviet Russia relations is one of the most controversial topics in Turkish historiography. The controversy was largely a product of the Cold War interpretations when the USSR and Turkey were in hostile camps. This article shows the Bolsheviks’ reappraisal and readjustment of their policy towards Turkey during the transition of Turkey from a war of independence to the foundation of a New Turkey in conditions of peace. In doing so, the paper focuses specifically on Ambassador Surits’ detailed reports on Turkey in 1923, including his policy recommendations. In this way the article attempts to contribute to our con . . .ception of the essence of Soviet–Turkey relations by taking into account Ambassador Surits’ reports as the primary sources. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group Daha fazlası Daha az

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