Hubert Szczerba, Karolina Dudziak, Zdzisław Targoński Department of Biotechnology, Microbiology and Human Nutrition; University of Life Sciences in Lublin 8 Skromna Street, 20-704 Lublin, Poland hubert.szczerba@up.lublin.pl; karolina.dudziak@umlub.pl Chair and Department of Biochemistry and Molecular Biology, Medical University of Lublin 1 Chodźki Street, 20-093 Lublin, Poland zdzislaw.targonski@up.lublin.pl
{"title":"Genome Analysis of Enterobacter sp. LU1, a Highly Efficient Succinic Acid Producer","authors":"H. Szczerba, Karolina Camargo, Z. Targoński","doi":"10.11159/ICBB19.128","DOIUrl":"https://doi.org/10.11159/ICBB19.128","url":null,"abstract":"Hubert Szczerba, Karolina Dudziak, Zdzisław Targoński Department of Biotechnology, Microbiology and Human Nutrition; University of Life Sciences in Lublin 8 Skromna Street, 20-704 Lublin, Poland hubert.szczerba@up.lublin.pl; karolina.dudziak@umlub.pl Chair and Department of Biochemistry and Molecular Biology, Medical University of Lublin 1 Chodźki Street, 20-093 Lublin, Poland zdzislaw.targonski@up.lublin.pl","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123485749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Extended Abstract Bacteria often use the so-called two-component system to transduce signal. A typical bacterial two-component system is comparatively simple and comprises two components, a sensor with histidine kinase activity and its cognate phosphorylatable response regulator [1, 2]. Most bacteria encode dozens of two-component signaling pathway [2]. Although both the histidine kinase sensor and response regulator in each two-component system are part of large, paralogous protein families that are highly similar at both sequence and structural levels, relatively little interaction between histidine kinase sensor and non-cognate response regulator was found, indicating that individual two-component signal transduction systems are highly specific, well insulated and rare cross-talk [3]. The high specificity of interaction between sensor and its cognate response regulator is accordant with the requirement for maintaining the faithful flow of signal through two-component system. Agrobacterium uses chemotaxis system to sense a large number of chemicals released by wounded host and VirA/VirG two-component system to induce the virulence gene expression [4, 5]. Chemotaxis signal transduction system is a special case of two-component system. Its histidine kinase CheA lacks transmembrane sensor domain and has three cognate response regulators, CheY1, CheY2 and CheB. Although the atypical two-component system, chemotaxis system is very different from the typical VirA/VirG two-component system, both of them are showed to be involved in Agrobacterium tumorigenesis [6]. Our previous study suggested that chemotaxis signaling and virulence induction signaling may have crosstalk in Agrobacterium [3]. Here, three lines of experimental evidences demonstrate the signaling cross-talk between these two two-component systems. 1) Chemotaxis signal-driving run pattern of Agrobacterium cheA-deletion mutant could be adjusted by the complementation of VirA. 2) Bacterial two hybrid assay showed that VirA interacts with CheY2 and CheA interacts with VirG. 3) In vitro pull-down experiment showed that VirA can pull-down CheY2.
{"title":"Signal Crosstalk between Two Different Agrobacterium Two-Component Systems","authors":"Minliang Guo, Yujuan Xu, Dawei Gao, Nan Xu","doi":"10.11159/ICBB19.110","DOIUrl":"https://doi.org/10.11159/ICBB19.110","url":null,"abstract":"Extended Abstract Bacteria often use the so-called two-component system to transduce signal. A typical bacterial two-component system is comparatively simple and comprises two components, a sensor with histidine kinase activity and its cognate phosphorylatable response regulator [1, 2]. Most bacteria encode dozens of two-component signaling pathway [2]. Although both the histidine kinase sensor and response regulator in each two-component system are part of large, paralogous protein families that are highly similar at both sequence and structural levels, relatively little interaction between histidine kinase sensor and non-cognate response regulator was found, indicating that individual two-component signal transduction systems are highly specific, well insulated and rare cross-talk [3]. The high specificity of interaction between sensor and its cognate response regulator is accordant with the requirement for maintaining the faithful flow of signal through two-component system. Agrobacterium uses chemotaxis system to sense a large number of chemicals released by wounded host and VirA/VirG two-component system to induce the virulence gene expression [4, 5]. Chemotaxis signal transduction system is a special case of two-component system. Its histidine kinase CheA lacks transmembrane sensor domain and has three cognate response regulators, CheY1, CheY2 and CheB. Although the atypical two-component system, chemotaxis system is very different from the typical VirA/VirG two-component system, both of them are showed to be involved in Agrobacterium tumorigenesis [6]. Our previous study suggested that chemotaxis signaling and virulence induction signaling may have crosstalk in Agrobacterium [3]. Here, three lines of experimental evidences demonstrate the signaling cross-talk between these two two-component systems. 1) Chemotaxis signal-driving run pattern of Agrobacterium cheA-deletion mutant could be adjusted by the complementation of VirA. 2) Bacterial two hybrid assay showed that VirA interacts with CheY2 and CheA interacts with VirG. 3) In vitro pull-down experiment showed that VirA can pull-down CheY2.","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130368634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Diatoms are one of the most important groups of photosynthetic microorganisms ubiquitous in all aquatic ecosystems. These inconspicuous organisms have achieved spectacular ecological success and furthermore, are used as model organisms in scientific research in the field of biochemistry and genetics. Their ecological success is provided by their ability to tolerance and fast acclimation to rapid changing environmental conditions. Ecological significance and the ease of culture facilitate investigation and attempts of explanation the mechanisms of processes occurring in these organisms on the physiological, biochemical and genetic level. This review describes a number of our investigation strategies and techniques to understand the phenomenon of these organisms. We focused on five important aspects of diatoms biology, presented here as the five different faces of these algae. Acclimation mechanisms to environmental factors (temperature, light, heavy metals, age of the culture), on physiological and biochemical level at short and long time exposition of diatoms, are presented as the first diatoms face. The second face presents diatoms as organisms useful for phytoremediation. The results of the molecular analyses of the selected enzymes involved in photoprotective mechanisms of diatoms is the third face of these algae. The significance of diatoms as a treasury of bioactive compounds (xanthophylls and long chain polyunsaturated fatty acids) important in human diet, is displayed as the fourth face. Finally, as the only one which has not been investigated in our laboratory, we describe the fifth face of diatoms – the rich source of biofuels. In our research we used two model diatoms species: Phaeodactylum tricornutum and Thalassiosira pseudonana.
{"title":"The Five Different Faces of the Diatoms","authors":"M. Bojko, D. Latowski","doi":"10.11159/ICEPR19.140","DOIUrl":"https://doi.org/10.11159/ICEPR19.140","url":null,"abstract":"Diatoms are one of the most important groups of photosynthetic microorganisms ubiquitous in all aquatic ecosystems. These inconspicuous organisms have achieved spectacular ecological success and furthermore, are used as model organisms in scientific research in the field of biochemistry and genetics. Their ecological success is provided by their ability to tolerance and fast acclimation to rapid changing environmental conditions. Ecological significance and the ease of culture facilitate investigation and attempts of explanation the mechanisms of processes occurring in these organisms on the physiological, biochemical and genetic level. This review describes a number of our investigation strategies and techniques to understand the phenomenon of these organisms. We focused on five important aspects of diatoms biology, presented here as the five different faces of these algae. Acclimation mechanisms to environmental factors (temperature, light, heavy metals, age of the culture), on physiological and biochemical level at short and long time exposition of diatoms, are presented as the first diatoms face. The second face presents diatoms as organisms useful for phytoremediation. The results of the molecular analyses of the selected enzymes involved in photoprotective mechanisms of diatoms is the third face of these algae. The significance of diatoms as a treasury of bioactive compounds (xanthophylls and long chain polyunsaturated fatty acids) important in human diet, is displayed as the fourth face. Finally, as the only one which has not been investigated in our laboratory, we describe the fifth face of diatoms – the rich source of biofuels. In our research we used two model diatoms species: Phaeodactylum tricornutum and Thalassiosira pseudonana.","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"84 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124691077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xuejiao Zhang, Chenzhong Jin, Yihong Hu, Yunyun Zhou, Wang Shuanghui
Extended Abstract Extraction optimization, purification and partial characteristics of polysaccharides from the traditional Chinese herb Rosae Laevigatae Michx were investigated. R. Leavigata belongs to the Rosa genus and Rosaceae family, and its fruits are widely used as health food in China, Japan and the other Asian countries [1]. In this study, the response surface methodology was used to optimize the extraction conditions of water-soluble polysaccharides from R. Laevigatae fruits. The central composite design was used to optimize the extraction processing parameters. The optimum extraction conditions were extraction temperature 95C, extraction time 2.5 h, water to raw material ratio 22:1, and extraction frequency 3. Under the optimum conditions, the experimental yield was 9.55±0.1%, which is in good agreement with the predicted yield. Six major fractions (RLP-I-1, RLP-I-2, RLP-I-3, RLP-II-1, RLP-II-2 and RLP-II-3) were successfully obtained by purifying the crude polysaccharides extracted from the fruits by using diethylaminoethanol-Sepharose column chromatography and Sepharose CL-4B column chromatography respectively. The molecular weights of major fractions were determined by the high performance gel permeation chromatography with a differential refractive index detector (Waters2410, USA) and a G5000 PWxl column (7.8 mm×300 mm, TOSOH, Japan) connected in series with a G3000 PWxl column (7.8 mm×300 mm, TOSOH, Japan). The average molecular weight of the RLP-I-1, RLP-I-2, RLP-I-3, RLP-II-1, RLP-II-2, RLP-II-3 were estimated to be 8930 Da, 9498 Da , 9662 Da, 7673 Da, 8558 Da and 8323 Da, respectively. The fourier transform infrared spectra of the six polysaccharides were identical, and the broad stretching intense characteristic peak was shown at 3400 cm 1 for the -OH group, whereas a weak C-H stretching band was observed from 2935-2939 cm. The peaks at 1616 cm were from the bending vibration absorption of -OH group. Absorption peaks ranged from 1460-1200 cm were the variable angle vibrations of C-H. The peaks from 1285 cm to 1020 cm corresponded to C-O stretching vibrations. The absorption band round 880 cm was due to the α-type glycosidic bond. Peaks ranged from 3600-3200 cm and 1655-1615 cm revealed that these compounds were carbohydrates. Moreover, no peaks were detected near 1715 cm suggesting that the fructan had no uronic acid [2]. In the present study, the anti-oxidative activities of the six polysaccharides toward super-oxide anion, hydroxyl, and 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radicals in vitro were evaluated in terms of scavenging rate. The assays suggested that RLP-II-1, RLP-II-2 and RLP-II-3 presented higher scavenging activity toward superoxide anions, hydroxyl and DPPH radicals. The results indicated that the response surface methodology was an effective method for the extraction of polysaccharides from the R. Laevigatae fruits, and the polysaccharides could be explored as a potential antioxidant agent for use in functiona
{"title":"Purification and Partial Characteristics of Polysaccharides from Rosa Laevigata Michx Fruits","authors":"Xuejiao Zhang, Chenzhong Jin, Yihong Hu, Yunyun Zhou, Wang Shuanghui","doi":"10.11159/ICBB19.122","DOIUrl":"https://doi.org/10.11159/ICBB19.122","url":null,"abstract":"Extended Abstract Extraction optimization, purification and partial characteristics of polysaccharides from the traditional Chinese herb Rosae Laevigatae Michx were investigated. R. Leavigata belongs to the Rosa genus and Rosaceae family, and its fruits are widely used as health food in China, Japan and the other Asian countries [1]. In this study, the response surface methodology was used to optimize the extraction conditions of water-soluble polysaccharides from R. Laevigatae fruits. The central composite design was used to optimize the extraction processing parameters. The optimum extraction conditions were extraction temperature 95C, extraction time 2.5 h, water to raw material ratio 22:1, and extraction frequency 3. Under the optimum conditions, the experimental yield was 9.55±0.1%, which is in good agreement with the predicted yield. Six major fractions (RLP-I-1, RLP-I-2, RLP-I-3, RLP-II-1, RLP-II-2 and RLP-II-3) were successfully obtained by purifying the crude polysaccharides extracted from the fruits by using diethylaminoethanol-Sepharose column chromatography and Sepharose CL-4B column chromatography respectively. The molecular weights of major fractions were determined by the high performance gel permeation chromatography with a differential refractive index detector (Waters2410, USA) and a G5000 PWxl column (7.8 mm×300 mm, TOSOH, Japan) connected in series with a G3000 PWxl column (7.8 mm×300 mm, TOSOH, Japan). The average molecular weight of the RLP-I-1, RLP-I-2, RLP-I-3, RLP-II-1, RLP-II-2, RLP-II-3 were estimated to be 8930 Da, 9498 Da , 9662 Da, 7673 Da, 8558 Da and 8323 Da, respectively. The fourier transform infrared spectra of the six polysaccharides were identical, and the broad stretching intense characteristic peak was shown at 3400 cm 1 for the -OH group, whereas a weak C-H stretching band was observed from 2935-2939 cm. The peaks at 1616 cm were from the bending vibration absorption of -OH group. Absorption peaks ranged from 1460-1200 cm were the variable angle vibrations of C-H. The peaks from 1285 cm to 1020 cm corresponded to C-O stretching vibrations. The absorption band round 880 cm was due to the α-type glycosidic bond. Peaks ranged from 3600-3200 cm and 1655-1615 cm revealed that these compounds were carbohydrates. Moreover, no peaks were detected near 1715 cm suggesting that the fructan had no uronic acid [2]. In the present study, the anti-oxidative activities of the six polysaccharides toward super-oxide anion, hydroxyl, and 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radicals in vitro were evaluated in terms of scavenging rate. The assays suggested that RLP-II-1, RLP-II-2 and RLP-II-3 presented higher scavenging activity toward superoxide anions, hydroxyl and DPPH radicals. The results indicated that the response surface methodology was an effective method for the extraction of polysaccharides from the R. Laevigatae fruits, and the polysaccharides could be explored as a potential antioxidant agent for use in functiona","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"40 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120875200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Soil Washing of Cyanide Contaminated Soil with Phosphate Solution","authors":"J. Kim","doi":"10.11159/ICEPR19.112","DOIUrl":"https://doi.org/10.11159/ICEPR19.112","url":null,"abstract":"","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130776862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Extended Abstract Despite the numerous potential applications of nanoparticles and the growing trends in scientific publications and patents, applications on vegetables and fruits shelf life extension are not yet available on the market. The growing demand for fresh vegetables and fruits leads to the constant challenge to develop innovative solutions for vegetables and fruits preservation. Nanoparticles such as gold, silver or copper nanoparticles have increasingly attracted the researcher’s interest for antimicrobial products due to their biological properties. Most harvested fruits and vegetables cannot be stored in natural conditions for a satisfactory shelf life duration due to their perishable nature. Conventional preservation methods have the limitations of high production cost and/or unsatisfactory shelf-life and/or undesirable residue. Due to unique properties, nanotechnology-related shelf life extension strategies have the potential to compensate the shortcomings of traditional preservation methods. At present, the methods for keeping fresh berries mainly include low-temperature refrigeration and fresh-keeping technology, modified atmosphere packaging storage technology UV shortwave ultraviolet radiation technology, chemical preservation etc. However, most of these treatments are expensive, time consuming, and may even damage the appearance of the berries. The objective of our research was to study the silver nanoparticles by the synthesis mediated with plant extracts and to evaluate their preservation effect on fresh berries. The vegetal material used for plant extracts was Vaccinium vitis idaea fruits and Petroselinum crispum leaves. The silver nanoparticles were formed by reducing silver nitrate solution with the plant extracts. Various concentrations of silver nanoparticles plant extracts solutions were investigated for their effect on prolongation of fruits shelf life. The fruit species used were Vaccinium myrtillus (blueberries) and Rubus fruticosus (blackberry). The influence of the mixtures on fruits preservation was evaluated by monitoring the sensorial and microbiological quality during the storage period. The synthesis of nanoparticles was characterized by the color change of mixture. The silver nanoparticles produced by green synthesis with both extracts showed the good results on prolongation of tested fruits shelf life. Our study demonstrated both the potential of green silver nanoparticles and the synergistic effect of plant extract and nanoparticles in preservation of fresh fruits.
{"title":"Application of Silver Nanoparticles on Fresh Fruits Preservation","authors":"M. Buțu, S. Rodino, A. Buțu","doi":"10.11159/ICNFA19.156","DOIUrl":"https://doi.org/10.11159/ICNFA19.156","url":null,"abstract":"Extended Abstract Despite the numerous potential applications of nanoparticles and the growing trends in scientific publications and patents, applications on vegetables and fruits shelf life extension are not yet available on the market. The growing demand for fresh vegetables and fruits leads to the constant challenge to develop innovative solutions for vegetables and fruits preservation. Nanoparticles such as gold, silver or copper nanoparticles have increasingly attracted the researcher’s interest for antimicrobial products due to their biological properties. Most harvested fruits and vegetables cannot be stored in natural conditions for a satisfactory shelf life duration due to their perishable nature. Conventional preservation methods have the limitations of high production cost and/or unsatisfactory shelf-life and/or undesirable residue. Due to unique properties, nanotechnology-related shelf life extension strategies have the potential to compensate the shortcomings of traditional preservation methods. At present, the methods for keeping fresh berries mainly include low-temperature refrigeration and fresh-keeping technology, modified atmosphere packaging storage technology UV shortwave ultraviolet radiation technology, chemical preservation etc. However, most of these treatments are expensive, time consuming, and may even damage the appearance of the berries. The objective of our research was to study the silver nanoparticles by the synthesis mediated with plant extracts and to evaluate their preservation effect on fresh berries. The vegetal material used for plant extracts was Vaccinium vitis idaea fruits and Petroselinum crispum leaves. The silver nanoparticles were formed by reducing silver nitrate solution with the plant extracts. Various concentrations of silver nanoparticles plant extracts solutions were investigated for their effect on prolongation of fruits shelf life. The fruit species used were Vaccinium myrtillus (blueberries) and Rubus fruticosus (blackberry). The influence of the mixtures on fruits preservation was evaluated by monitoring the sensorial and microbiological quality during the storage period. The synthesis of nanoparticles was characterized by the color change of mixture. The silver nanoparticles produced by green synthesis with both extracts showed the good results on prolongation of tested fruits shelf life. Our study demonstrated both the potential of green silver nanoparticles and the synergistic effect of plant extract and nanoparticles in preservation of fresh fruits.","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130976310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Baumli, L. Somlyai-Sipos, M. Czagány, D. Janovszky
The melting point is one of the most important thermodynamic properties of metallic materials. The melting point, that characterizes the bulk material is independent of the size in the microscopic range but will be size-dependent in the nano-range. The reason of this phenomenon is the high surface to volume ratio, thus the atoms situated on the surface play a greater role. One of the objectives of our research was to synthetize nickel nanoparticles (Ni NPs) using aqueous medium technology. The analysis of the produced particles was performed by X-ray diffraction (XRD) and Scanning electron microscopy (SEM). Furthermore, the main objective of our work was to determine the size dependence of the melting point of the produced nickel nanoparticles by differential scanning
{"title":"Synthesis and Investigation of Nickel Nanoparticles","authors":"P. Baumli, L. Somlyai-Sipos, M. Czagány, D. Janovszky","doi":"10.11159/ICNFA19.118","DOIUrl":"https://doi.org/10.11159/ICNFA19.118","url":null,"abstract":"The melting point is one of the most important thermodynamic properties of metallic materials. The melting point, that characterizes the bulk material is independent of the size in the microscopic range but will be size-dependent in the nano-range. The reason of this phenomenon is the high surface to volume ratio, thus the atoms situated on the surface play a greater role. One of the objectives of our research was to synthetize nickel nanoparticles (Ni NPs) using aqueous medium technology. The analysis of the produced particles was performed by X-ray diffraction (XRD) and Scanning electron microscopy (SEM). Furthermore, the main objective of our work was to determine the size dependence of the melting point of the produced nickel nanoparticles by differential scanning","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134123942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Extended Abstract Recently, oxide heterostructure-based two-dimensional electron gas (2DEG) has received intensive attentions owing to their interesting properties. The model system is epitaxial LaAlO3 (LAO) grown on single crystalline SrTiO3 (STO) substrate.[1] Electrons with a density of 10~10/cm were observed which moves freely along in-plane direction while they are confined within ~2 nm (out-of-plane direction). Unfortunately, the adjustment of electron density was not available for the epitaxial LAO/STO heterostructure. In addition, the growth of epitaxial LAO film requires a high-temperature process (700 ~ 800°C) using pulsed laser deposition technique. Here, we demonstrated a creation and control of 2DEG at the interface of non-epitaxial Al2O3/TiO2 thin film heterostructure using atomic layer deposition (ALD). The electron density can be tailored from ~ 10/cm to ~ 10/cm by the control of ALD process temperature because the electrons are coming from oxygen vacancies at the interface of Al2O3/TiO2 heterostructure of which oxygen vacancy density is governed by kinetics during the ALD process. Electron density up to ~10/cm was achieved at the interface of the Al2O3/TiO2 heterostructure which is 100 times higher than that of the conventional semiconductor heterojunction such as AlGaAs/GaAs. The 2DEG at Al2O3/TiO2 heterostructure can be applied for the development hydrogen (H2) gas sensor. A highperformance, transparent, and extremely thin (<15 nm) hydrogen gas sensor was fabricated using 2DEG at the interface of Al2O3/TiO2 heterostructure grown by ALD. [2] Palladium nanoparticles (≈2 nm in thickness) are used on the surface of the Al2O3/TiO2 thin film heterostructure to detect H2. Both oxides with a wide bandgap (>3.2 eV) have transmittance of 83% in the visible spectrum, which allows for a transparent sensor. The Pd/Al2O3/TiO2 gas senor detects H2 gas quickly with a short response time of <30 s even at room temperature which outperforms conventional H2 gas sensors. This sensor responds to a wide range of H2 concentration, especially from ~5 ppm to 1%, implying a promising candidate for a general H2 sensor. Interestingly, the Pd/Al2O3/TiO2 gas senor showed an optimal electron density for H2 detection owing to the tailoring ability of 2DEG at the Al2O3/TiO2 heterostructure. Particularly, a sensitivity was as low as 3% for a 2DEG density of 5.6 × 10 cm while the sensitivity was improved from 6% to 43% as the electron density decreased from 5.6 × 10 cm to 4.1 × 10 cm. Besides the sensor application, other application of 2DEG will be introduced in the presentation.
{"title":"Tailoring of Two-dimensional Electron Gas Density in Thin Film Oxide Heterostructure via Atomic Layer Deposition","authors":"S. H. Kim, Hye Ju Kim, Sang Woon Lee","doi":"10.11159/ICNFA19.135","DOIUrl":"https://doi.org/10.11159/ICNFA19.135","url":null,"abstract":"Extended Abstract Recently, oxide heterostructure-based two-dimensional electron gas (2DEG) has received intensive attentions owing to their interesting properties. The model system is epitaxial LaAlO3 (LAO) grown on single crystalline SrTiO3 (STO) substrate.[1] Electrons with a density of 10~10/cm were observed which moves freely along in-plane direction while they are confined within ~2 nm (out-of-plane direction). Unfortunately, the adjustment of electron density was not available for the epitaxial LAO/STO heterostructure. In addition, the growth of epitaxial LAO film requires a high-temperature process (700 ~ 800°C) using pulsed laser deposition technique. Here, we demonstrated a creation and control of 2DEG at the interface of non-epitaxial Al2O3/TiO2 thin film heterostructure using atomic layer deposition (ALD). The electron density can be tailored from ~ 10/cm to ~ 10/cm by the control of ALD process temperature because the electrons are coming from oxygen vacancies at the interface of Al2O3/TiO2 heterostructure of which oxygen vacancy density is governed by kinetics during the ALD process. Electron density up to ~10/cm was achieved at the interface of the Al2O3/TiO2 heterostructure which is 100 times higher than that of the conventional semiconductor heterojunction such as AlGaAs/GaAs. The 2DEG at Al2O3/TiO2 heterostructure can be applied for the development hydrogen (H2) gas sensor. A highperformance, transparent, and extremely thin (<15 nm) hydrogen gas sensor was fabricated using 2DEG at the interface of Al2O3/TiO2 heterostructure grown by ALD. [2] Palladium nanoparticles (≈2 nm in thickness) are used on the surface of the Al2O3/TiO2 thin film heterostructure to detect H2. Both oxides with a wide bandgap (>3.2 eV) have transmittance of 83% in the visible spectrum, which allows for a transparent sensor. The Pd/Al2O3/TiO2 gas senor detects H2 gas quickly with a short response time of <30 s even at room temperature which outperforms conventional H2 gas sensors. This sensor responds to a wide range of H2 concentration, especially from ~5 ppm to 1%, implying a promising candidate for a general H2 sensor. Interestingly, the Pd/Al2O3/TiO2 gas senor showed an optimal electron density for H2 detection owing to the tailoring ability of 2DEG at the Al2O3/TiO2 heterostructure. Particularly, a sensitivity was as low as 3% for a 2DEG density of 5.6 × 10 cm while the sensitivity was improved from 6% to 43% as the electron density decreased from 5.6 × 10 cm to 4.1 × 10 cm. Besides the sensor application, other application of 2DEG will be introduced in the presentation.","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130157251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Genomic and Molecular Mechanisms for Efficient Biodegradation of Aromatic Dye in Presence of Lignin","authors":"Su Sun, Hongbo Yu, Xiaoyu Zhang, Shangxian Xie","doi":"10.11159/ICBB19.120","DOIUrl":"https://doi.org/10.11159/ICBB19.120","url":null,"abstract":"","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115048762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jessica Sierra-Agudelo, L. Figueras, M. Mir, Roberto Paoli, R. Rodriguez-Trujillo, J. Samitier
{"title":"Microfluidic Techniques for Circulating Tumour Cells Separation","authors":"Jessica Sierra-Agudelo, L. Figueras, M. Mir, Roberto Paoli, R. Rodriguez-Trujillo, J. Samitier","doi":"10.11159/ICBB19.108","DOIUrl":"https://doi.org/10.11159/ICBB19.108","url":null,"abstract":"","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"360 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134228429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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