Development of near-infrared region luminescent N-acetyl-L-cysteine-coated Ag2S quantum dots with differential therapeutic effect

Aim: N-acetyl-L-cysteine (NAC) is a free radical scavenger. We developed NAC-coated Ag2S (NAC-Ag2S) quantum dot (QD) as an optical imaging and therapeutic agent. Materials & methods: QDs were synthesized in water. Their optical imaging potential and toxicity were studied in vitro. Results: NAC-Ag2S QDs have strong emission, that is tunable between 748 and 840 nm, and are stable in biologically relevant media. QDs showed significant differences both in cell internalization and toxicity in vitro. QDs were quite toxic to breast and cervical cancer cells but not to lung derived cells despite the higher uptake. NAC-Ag2S reduces reactive oxygen species (ROS) but causes cell death via DNA damage and apoptosis. Conclusion: NAC-Ag2S QDs are stable and strong signal-generating theranostic agents offering selective therapeutic effects

Bioethanol production by syngas fermentation from pyrolysis gas using mixed culture: Heat-pretreatment effect

Duman, Gozde/0000-0002-9427-8235; Gundogdu, Tugba Keskin/0000-0001-9354-7774WOS:000597063900016In recent years, the production of bioethanol from synthesis gas offers a common solution to the increasing levels of air pollution and the need for renewable energy sources. Synthesis gas is the combination of gases such as CO, CO2, N-2, H-2, NOx, which can form air pollution and can be used in the production of bioethanol by metabolizing these gases by Clostiridium species. Bioethanol is one of the most important biofuels because of the advantage of direct use by blending with gasoline. Pyrolysis and biochar production is an important alternative to expensive pretreatment methods used in waste and lignocellulosic raw materials in bioethanol production. in this study the wastes were converted into biochar by pyrolysis and the waste gas is collected to produce bioethanol which is an integrated and energy intensive approach. The use of mixed culture in the production of ethanol from pyrolysis gas instead of pure Clostiridium species is also important in terms of reducing costs. in this study, by using the the waste gas released during biochar production from fruit and vegetable wastes ethanol produced by syngas fermentation using heat pretreated mixed culture. While the positive effect of heat pretreatment was observed in the mixed culture, the amount of pyrolysis gas to be fed to the reactors was optimized and the highest ethanol production was observed in 5 and 10 mL pyrolysis gas feedings as 5 g/L.TUBITAK-CAYDAGTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [118Y305]The authors wish to thank to TUBITAK-CAYDAG for financial support Under grant number 118Y305, for technical support to Prof. Dr. Nuri Azbar and Prof. Dr. Jale Yanik and for advisory support to Dr. Haris Nalakath Abubackar

Two-step steam pyrolysis of biomass for hydrogen production

WOS: 000406725500009In this study, different char based catalysts were evaluated in order to increase hydrogen production from the steam pyrolysis of olive pomace in two stage fixed bed reactor system. Biomass char, nickel loaded biomass char, coal char and nickel or iron loaded coal chars were used as catalyst. Acid washed biomass char was also tested to investigate the effect of inorganics in char on catalytic activity for hydrogen production. Catalysts were characterized by using Brunauer Emmet Teller (BET) method, X-ray diffraction (XRD) analyzer, X-ray fluorescence (XRF) and thermogravimetric analyzer (TGA). The results showed that the steam in absence of catalyst had no influence on hydrogen production. Increase in catalytic bed temperature (from 500 degrees C to 700 degrees C) enhanced hydrogen production in presence of Ni-impregnated and non -impregnated biomass char. Inherent inorganic content of char had great effect on hydrogen production. Ni based biomass char exhibited the highest catalytic activity in terms of hydrogen production. Besides, Ni and Fe based coal char had catalytic activity on H-2 production. On the other hand, the results showed that biomass char was not thermally stable under steam pyrolysis conditions. Weight loss of catalyst during steam pyrolysis could be attributed to steam gasification of biomass char itself. In contrast, properties of coal char based catalysts after steam pyrolysis process remained nearly unchanged, leading to better thermal stability than biomass char. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.Ege UniversityEge University [2012-FEN-041]The financial support from Ege University under contract 2012-FEN-041 is highly appreciated. The authors wish to thank Chiara Lorenzetti for GC/MS analysis of bio-oil and Prof. Dr. Daniele Fabbri for interpretation of GC/MS results

Hydrogen production from algal biomass via steam gasification

WOS: 000338711100004PubMed ID: 24880809Algal biomasses were tested as feedstock for steam gasification in a dual-bed microreactor in a two-stage process. Gasification experiments were carried out in absence and presence of catalyst. The catalysts used were 10% Fe2O3-90% CeO2 and red mud (activated and natural forms). Effects of catalysts on tar formation and gasification efficiencies were comparatively investigated. It was observed that the characteristic of algae gasification was dependent on its components and the catalysts used. The main role of the catalyst was reforming of the tar derived from algae pyrolysis, besides enhancing water gas shift reaction. The tar reduction levels were in the range of 80-100% for seaweeds and of 53-70% for microalgae. Fe2O3-CeO2 was found to be the most effective catalyst. The maximum hydrogen yields obtained were 1036 cc/g algae for Fucus serratus, 937 cc/g algae for Laminaria digitata and 413 cc/g algae for Nannochloropsis oculata. (C) 2014 Elsevier Ltd. All rights reserved.FP7 Marie-Curie IAPP-Project [230598]We would like to acknowledge FP7 Marie-Curie IAPP-Project No: 230598 for providing algae which are investigated in that project and financially supporting Prof. Dr. Jale Yanik. We also thank to Prof. Dr. Yoshiei Kato for his collaboration and invitation to Environmental Analytical Chemistry Laboratory, Okayama University

The effect of char properties on gasification reactivity

WOS: 000329384200011In this study, CO2 gasification of raw and acid-washed chars obtained from various types of lignocellulosic biomasses (woody and agricultural waste biomasses) was studied under isothermal conditions (850 degrees C) using thermal gravimetric analysis. The effect of surface area and alkali/earth alkali metals on the reactivity of the chars was investigated. The different kinetic models were used to fit with the reactivity data by using least square. method. The gasification of chars with higher surface area was found to be faster than that of chars having lower surface area. The acid treatment decreased the overall gasification rate for each raw chars. However, although the AI (alkali index) values of chars obtained from agricultural biomasses had equal or higher than that of woody biomass chars, their initial rates were considerably lower. It was concluded that indigenous alkali metals of chars have a remarkable influence of gasification reactivity but an adequate surface area should be provided to react with CO2. (C) 2013 Elsevier B.V. All rights reserved.European CommissionEuropean Commission Joint Research Centre [IRSES 247550]The research is funded by the European Commission in the framework of 7th Programme, Project No: IRSES 247550. We also thank to Prof. Dr. Yoshiei Kato for his collaboration and invitation to Environmental Analytical Chemistry Laboratory, Okayama University

Influences of feedstock type and process variables on hydrochar properties

WOS: 000430740000042PubMed ID: 29182991In this study, the effect of process variables, such as temperature, biomass: water ratio and reaction time, in hydrothermal carbonization (HTC) has been studied for different type biomasses. Response surface methodology was used to study the influence of each factors as well as their combined interactive effect on the mass yield and energy density of hydrochars. The results showed that the temperature and time were significant factors effecting the mass yield and energy densification ratio in HTC of the sunflower stalk and algae, whereas temperature was only significant factor in HTC of poultry litter. The biomass: water ratio was found insignificant for all tested biomasses. In addition, the fuel properties of hydrochars were compared with the properties of biochar derived from torrefaction at 300 degrees C. The results showed that for all tested biomass, the biochars had lower volatile matter and fixed carbon than hydrochars.TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [114 M001, 2014/FEN/055]The financial supports from TUBITAK under contract 114 M001 and 2014/FEN/055 are gratefully acknowledged. The authors would like to acknowledge the contribution of the COST Action TD1107 (Biochar as option for sustainable resource management)

Two-step pyrolysis of safflower oil cake

19th International Symposium on Analytical and Applied Pyrolysis (PYROLYSIS) -- MAY 21-25, 2012 -- Johannes Kepler Univ, Linz, AUSTRIAWOS: 000323852400046The thermal and catalytic pyrolysis of safflower oil cake was studied in a dual reactor system over catalyst; the first reactor containing no catalyst whereas the second reactor containing catalyst to upgrade the thermally cracked products. For comparison, pyrolysis experiments were also carried out in a single reactor system. The aim was to study the effect of catalyst and temperature on the product yields and composition of the bio-oil. The used catalysts are fluid catalytic cracking catalyst, red mud and activated red mud. The pyrolysis experiments were carried out at varying temperatures between 300 and 600 degrees C in thermal reactor and 300-500 degrees C in catalytic reactor. Although, the catalysts had no considerable effect on the yield of the pyrolysis product, they affected the bio-oil composition. It was very important observation that the amount of pyrolytic lignin compounds (11.8-27.5 wt%) was significantly lower and extractives (50.0-65.1 wt%) were higher in case of catalytic experiments. The H/C-eff ratio of bio-oils indicated that used catalysts had effective on deoxygenation. The gas chromatography-mass spectrometry analysis showed that the phenols were the dominant species in all bio-oils and their relative amounts, ranging from 26 to 35 wt%, did not significantly changed with the pyrolysis conditions. The spent fluid catalytic cracking catalyst was successfully regenerated to achieve their original activity. (c) 2012 Elsevier B.V. All rights reserved.Bruker, CDS Analyt, Frontier Lab, Gerstel, JKU Chem Serv, Linz Tourism, Syreta, Shimadzu, Thermo Sc