Biopolymer based nanocomposites reinforced with graphene nanoplatelets

Energy Technology Data Exchange (ETDEWEB)

Botta, L.; Scaffaro, R.; Mistretta, M. C.; La Mantia, F. P. [Dipartimento di Ingegneria Civile, Ambientale, Aerospaziale, dei Materiali, Università di Palermo, UdR INSTM di Palermo, Viale delle Scienze, 90128 Palermo (Italy)

2016-05-18

In this work, biopolymer based nanocomposites filled with graphene nanoplatelets (GnP) were prepared by melt compounding in a batch mixer. The polymer used as matrix was a commercial biodegradable polymer-blend of PLA and a copolyester (BioFlex®). The prepared materials were characterized by scanning electron microscopy (SEM), rheological and mechanical measurements. Moreover, the effect of the GnP amount on the investigated properties was evaluated. The results indicated that the incorporation of GnP increased the stiffness of the biopolymeric matrix.

Investigation on wear characteristic of biopolymer gear

Science.gov (United States)

Ghazali, Wafiuddin Bin Md; Daing Idris, Daing Mohamad Nafiz Bin; Sofian, Azizul Helmi Bin; Basrawi, Mohamad Firdaus bin; Khalil Ibrahim, Thamir

2017-10-01

Polymer is widely used in many mechanical components such as gear. With the world going to a more green and sustainable environment, polymers which are bio based are being recognized as a replacement for conventional polymers based on fossil fuel. The use of biopolymer in mechanical components especially gear have not been fully explored yet. This research focuses on biopolymer for spur gear and whether the conventional method to investigate wear characteristic is applicable. The spur gears are produced by injection moulding and tested on several speeds using a custom test equipment. The wear formation such as tooth fracture, tooth deformation, debris and weight loss was observed on the biopolymer spur gear. It was noted that the biopolymer gear wear mechanism was similar with other type of polymer spur gears. It also undergoes stages of wear which are; running in, linear and rapid. It can be said that the wear mechanism of biopolymer spur gear is comparable to fossil fuel based polymer spur gear, thus it can be considered to replace polymer gears in suitable applications.

Applications of Biopolymers Modified by Radiation Processing. Chapter 12

Energy Technology Data Exchange (ETDEWEB)

Tamada, M. [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, Takasaki (Japan)

2014-07-15

Radiation processing using quantum beam such as electron beam and gamma rays is a clean process. Using this process, biopolymers with low environmental burden were modified for agricultural and environmental applications. High performance materials such as soil conditioner for arid area, spray coating Washi (Japanese paper), biodegradable dummy lens, chemically-induced biodegradable plastic, biodiesel catalyst, and plant growth promoter were developed by radiationinduced crosslinking, graft polymerization, and degradation. (author)

Electronic Resource Management and Design

Science.gov (United States)

Abrams, Kimberly R.

2015-01-01

We have now reached a tipping point at which electronic resources comprise more than half of academic library budgets. Because of the increasing work associated with the ever-increasing number of e-resources, there is a trend to distribute work throughout the library even in the presence of an electronic resources department. In 2013, the author…

Autonomous valve for detection of biopolymer degradation

DEFF Research Database (Denmark)

Keller, Stephan Urs; Noeth, Nadine-Nicole; Fetz, Stefanie

2009-01-01

We present a polymer microvalve that allows the detection of biopolymer degradation without the need of external energy. The valve is based on a polymer container filled with a colored marker solution and closed by a thin lid. This structure is covered by a film of poly(L-lactide) and degradation...... of the biopolymer triggers the release of the color which is detected visually. The autonomous valve has potential for the fast testing of biopolymer degradation under various environmental conditions or by specific enzymes....

Biopolymer chitin: extraction and characterization; Biopolimero quitina: extracao e caracterizacao

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-07-01

The biopolymers are materials made from renewable sources such as soybean, corn, cane sugar, cellulose and chitin. Chitin is the most abundant biopolymer found in nature, after cellulose. The chemical structure of chitin is distinguished by the hydroxyl group, of structure from cellulose, located at position C-2, which in the chitin is replaced by acetamine group. The objective of this study was to develop the chitin from exoskeletons of Litopenaeus vannamei shrimp, which are discarded as waste, causing pollutions, environmental problems and thus obtain better utilization of these raw materials. It also, show the extraction process and deacetylation of chitosan. The extraction of chitin followed steps of demineralization, desproteinization and deodorization. Chitin and chitosan were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and the thermals properties were analyzed by thermogravimetry (TG/DTG). (author)

The physicochemical properties of a spray dried glutinous rice starch biopolymer.

Science.gov (United States)

Laovachirasuwan, Pornpun; Peerapattana, Jomjai; Srijesdaruk, Voranuch; Chitropas, Padungkwan; Otsuka, Makoto

2010-06-15

Glutinous rice starch (GRS) is a biopolymer used widely in the food industry but not at all in the pharmaceutical industry. There are several ways to modify this biopolymer. Physical modification is simple and cheap because it requires no chemicals or biological agents. The aim of this study was to characterize the physicochemical properties of a spray dried glutinous rice starch (SGRS) produced from pregelatinized GRS. The surface morphology changed from an irregular to concave spherical shape as revealed by Scanning Electron Microscopy (SEM). SGRS was almost amorphous as determined by X-ray Diffraction (XRD) spectroscopy. The water molecules became linked through hydrogen bonds to the exposed hydroxyl group of amorphous SGRS as determined by Near Infrared (NIR) spectroscopy. Then, SGRS formed a colloid gel matrix with water and developed a highly viscous gelatinous form as determined using Differential Scanning Calorimetry (DSC) and a stress control type rheometer. In addition, SGRS can swell and produce a gelatinous surface barrier like a hydrophilic matrix biopolymer which controls drug release. Therefore, a novel application of SGRS is as a sustained release modifier for direct compression tablets in the pharmaceutical industry. Copyright 2010 Elsevier B.V. All rights reserved.

Proton conduction in biopolymer exopolysaccharide succinoglycan

Energy Technology Data Exchange (ETDEWEB)

Kweon, Jin Jung [Department of Physics, Korea University, Seoul 136-713 (Korea, Republic of); National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310 (United States); Lee, Kyu Won; Kim, Hyojung; Lee, Cheol Eui, E-mail: rscel@korea.ac.kr [Department of Physics, Korea University, Seoul 136-713 (Korea, Republic of); Jung, Seunho [Department of Bioscience and Biotechnology and UBITA, Konkuk University, Seoul 143-701 (Korea, Republic of); Kwon, Chanho [Naraebio Research Laboratories, 177 Dangha-ri, Bongdam-eup, Hawseong-si 445-892 (Korea, Republic of)

2014-07-07

Protonic currents play a vital role in electrical signalling in living systems. It has been suggested that succinoglycan plays a specific role in alfalfa root nodule development, presumably acting as the signaling molecules. In this regard, charge transport and proton dynamics in the biopolymer exopolysaccharide succinoglycan have been studied by means of electrical measurements and nuclear magnetic resonance (NMR) spectroscopy. In particular, a dielectric dispersion in the system has revealed that the electrical conduction is protonic rather electronic. Besides, our laboratory- and rotating-frame {sup 1}H NMR measurements have elucidated the nature of the protonic conduction, activation of the protonic motion being associated with a glass transition.

Hybrid waste filler filled bio-polymer foam composites for sound absorbent materials

Science.gov (United States)

Rus, Anika Zafiah M.; Azahari, M. Shafiq M.; Kormin, Shaharuddin; Soon, Leong Bong; Zaliran, M. Taufiq; Ahraz Sadrina M. F., L.

2017-09-01

Sound absorption materials are one of the major requirements in many industries with regards to the sound insulation developed should be efficient to reduce sound. This is also important to contribute in economically ways of producing sound absorbing materials which is cheaper and user friendly. Thus, in this research, the sound absorbent properties of bio-polymer foam filled with hybrid fillers of wood dust and waste tire rubber has been investigated. Waste cooking oil from crisp industries was converted into bio-monomer, filled with different proportion ratio of fillers and fabricated into bio-polymer foam composite. Two fabrication methods is applied which is the Close Mold Method (CMM) and Open Mold Method (OMM). A total of four bio-polymer foam composite samples were produce for each method used. The percentage of hybrid fillers; mixture of wood dust and waste tire rubber of 2.5 %, 5.0%, 7.5% and 10% weight to weight ration with bio-monomer. The sound absorption of the bio-polymer foam composites samples were tested by using the impedance tube test according to the ASTM E-1050 and Scanning Electron Microscope to determine the morphology and porosity of the samples. The sound absorption coefficient (α) at different frequency range revealed that the polymer foam of 10.0 % hybrid fillers shows highest α of 0.963. The highest hybrid filler loading contributing to smallest pore sizes but highest interconnected pores. This also revealed that when highly porous material is exposed to incident sound waves, the air molecules at the surface of the material and within the pores of the material are forced to vibrate and loses some of their original energy. This is concluded that the suitability of bio-polymer foam filled with hybrid fillers to be used in acoustic application of automotive components such as dashboards, door panels, cushion and etc.

Incorporation of zinc oxide to dispersions of biopolymers and release of the metallic ion in vitro

International Nuclear Information System (INIS)

Barreto, Marina S.R.; Ferreira, Willian H.; Andrade, Cristina T.

2015-01-01

Zinc oxide (ZnO) nanoparticles, obtained from a commercial product, were dispersed in different biopolymers, to be added to piglet feeds. The resulting products, prepared with sodium alginate (SA), chitosan (CH) and low methoxyl pectin (LMP) were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The release of Zn"2"+ was investigated under simulated conditions of the gastrointestinal tract of piglets, and analyzed by atomic absorption spectroscopy (AA). The results showed that the structural factors, which have influence on the biopolymer/ZnO interactions, govern the behavior of Zn"2"+ release. (author)

Phase distribution of products of radiation and post-radiation distillation of biopolymers: Cellulose, lignin and chitin

International Nuclear Information System (INIS)

Ponomarev, A.V.; Kholodkova, E.M.; Metreveli, A.K.; Metreveli, P.K.; Erasov, V.S.; Bludenko, A.V.; Chulkov, V.N.

2011-01-01

Influence of both the absorbed dose and the dose rate of 8 MeV electron-beam radiation on destruction of microcrystalline cellulose, pine lignin and krill chitin was investigated. Two conversion modes were compared: (1) post-radiation distillation PRD and (2) electron-beam distillation EBD. Cellulose, chitin and lignin demonstrate different responses to irradiation and distillation in PRD and EBD modes. Treatment in EBD mode transforms biopolymers to organic liquid more productively than conventional dry distillation and treatment in PRD mode. Both radiation heating and an irradiation without heating intensify chitin and cellulose decomposition and distillation. At the same time lignin decaying rather efficiently in EBD mode appears to be insensitive to a preliminary irradiation in PRD mode up to a dose of 2.4 MGy. - Highlights: → Direct conversion of cellulose, chitin and lignin to organic liquid is intensified by electron-beam irradiation. → Alternative approach to bio-oil production. → Both electron-beam distillation mode and post-radiation distillation mode are effective for cellulose and chitin conversion. → Electron-beam distillation mode is preferable for lignin conversion. → Preliminary deep dehydration of biopolymers is realizable at low dose rates.

Lignin biopolymer based triboelectric nanogenerators

Science.gov (United States)

Bao, Yukai; Wang, Ruoxing; Lu, Yunmei; Wu, Wenzhuo

2017-07-01

Ongoing research in triboelectric nanogenerators (TENGs) focuses on increasing power generation, but obstacles concerning economical and eco-friendly utilization of TENGs continue to prevail. Being the second most abundant biopolymer on earth, lignin offers a valuable opportunity for low-cost TENG applications in biomedical devices, benefitting from its biodegradability and biocompatibility. Here, we develop for the first time a lignin biopolymer based TENGs for harvesting mechanical energy in the environment, which shows great potential for self-powered biomedical devices among other applications and opens doors to new technologies that utilize otherwise wasted materials for economically feasible and ecologically friendly production of energy devices.

Biopolymers coated superparamagnetic Nickel Ferrites: Enhanced biocompatibility and MR imaging probe for breast cancer

Energy Technology Data Exchange (ETDEWEB)

Bano, Shazia, E-mail: shaziaphy@gmail.com [Department of Physics, The Islamia University of Bahawalpur (Pakistan); Zafar, Tayyaba [Department of Physics, The Islamia University of Bahawalpur (Pakistan); Akhtar, Shahnaz [Department of Pharmacy, The Islamia University of Bahawalpur (Pakistan); Buzdar, Saeed Ahmed [Department of Physics, The Islamia University of Bahawalpur (Pakistan); Waraich, Mustansar Mahmood, E-mail: mustansarwaraich@gmail.com [Quaid-e-Azam Medical College B.V. Hospital, Bahawalpur (Pakistan); Afzal, Muhammad [Department of Physics, The Islamia University of Bahawalpur (Pakistan)

2016-11-01

We report evidence for the promising application of bovine serum albumin (BSA), chitosan (CS) or carboxymethyl cellulose (CMC) coated NiFe{sub 2}O{sub 4} cores for improved biocompatibility and enhanced T2 relaxivity, through a single combinatorial approach. Pure nickel-ferrite nano cores (NFs) successfully synthesized by thermolysis, were immobilize with BSA, CS or CMC layer employing a simple cross linking procedure to avoid any significant influence of these biopolymers on the morphology and crystal structure of the cores. Phase, morphology, magnetic hysteresis and surface chemistry were characterized by X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), vibrating sample magnetometer (VSM) and Fourier transform infrared (FTIR) spectroscopy. The preliminary haemolysis and cell viability experiments show that biopolymers conjugation mitigates the haemolytic effect of the NFs on erythrocytes as the haemolytic index is less than 2% and cell viability is up to 100%, when normalized with the nontreated cells. The relaxivity value of coated NFs is 351±2.6 when compared to 84±0.22 of NFs without biopolymer conjugation. The results demonstrate that BSA, CS or CMC covering on NFs provide a single combinatorial approach to improve the biocompatibility and enhance the relaxivity value. Thus addressing the current challenge of the same with very good contrast for targeting MCF-7 without any further vectorization. - Highlights: • A single combinatorial system for the promising application of biopolymers coated NiFe{sub 2}O{sub 4} cores. • Immobilization of a thin layer of three different biopolymers via a simple approach. • Excellent MR contrast enhancement and targeting of MCF-7 without any further vectorization.

Fabrication of Porous Materials from Natural/Synthetic Biopolymers and Their Composites

Directory of Open Access Journals (Sweden)

Udeni Gunathilake T.M. Sampath

2016-12-01

Full Text Available Biopolymers and their applications have been widely studied in recent years. Replacing the oil based polymer materials with biopolymers in a sustainable manner might give not only a competitive advantage but, in addition, they possess unique properties which cannot be emulated by conventional polymers. This review covers the fabrication of porous materials from natural biopolymers (cellulose, chitosan, collagen, synthetic biopolymers (poly(lactic acid, poly(lactic-co-glycolic acid and their composite materials. Properties of biopolymers strongly depend on the polymer structure and are of great importance when fabricating the polymer into intended applications. Biopolymers find a large spectrum of application in the medical field. Other fields such as packaging, technical, environmental, agricultural and food are also gaining importance. The introduction of porosity into a biomaterial broadens the scope of applications. There are many techniques used to fabricate porous polymers. Fabrication methods, including the basic and conventional techniques to the more recent ones, are reviewed. Advantages and limitations of each method are discussed in detail. Special emphasis is placed on the pore characteristics of biomaterials used for various applications. This review can aid in furthering our understanding of the fabrication methods and about controlling the porosity and microarchitecture of porous biopolymer materials.

Fabrication of Porous Materials from Natural/Synthetic Biopolymers and Their Composites.

Science.gov (United States)

Sampath, Udeni Gunathilake T M; Ching, Yern Chee; Chuah, Cheng Hock; Sabariah, Johari J; Lin, Pai-Chen

2016-12-07

Biopolymers and their applications have been widely studied in recent years. Replacing the oil based polymer materials with biopolymers in a sustainable manner might give not only a competitive advantage but, in addition, they possess unique properties which cannot be emulated by conventional polymers. This review covers the fabrication of porous materials from natural biopolymers (cellulose, chitosan, collagen), synthetic biopolymers (poly(lactic acid), poly(lactic- co -glycolic acid)) and their composite materials. Properties of biopolymers strongly depend on the polymer structure and are of great importance when fabricating the polymer into intended applications. Biopolymers find a large spectrum of application in the medical field. Other fields such as packaging, technical, environmental, agricultural and food are also gaining importance. The introduction of porosity into a biomaterial broadens the scope of applications. There are many techniques used to fabricate porous polymers. Fabrication methods, including the basic and conventional techniques to the more recent ones, are reviewed. Advantages and limitations of each method are discussed in detail. Special emphasis is placed on the pore characteristics of biomaterials used for various applications. This review can aid in furthering our understanding of the fabrication methods and about controlling the porosity and microarchitecture of porous biopolymer materials.

Electronic Resource Management Systems

Directory of Open Access Journals (Sweden)

Mark Ellingsen

2004-10-01

Full Text Available Computer applications which deal with electronic resource management (ERM are quite a recent development. They have grown out of the need to manage the burgeoning number of electronic resources particularly electronic journals. Typically, in the early years of e-journal acquisition, library staff provided an easy means of accessing these journals by providing an alphabetical list on a web page. Some went as far as categorising the e-journals by subject and then grouping the journals either on a single web page or by using multiple pages. It didn't take long before it was recognised that it would be more efficient to dynamically generate the pages from a database rather than to continually edit the pages manually. Of course, once the descriptive metadata for an electronic journal was held within a database the next logical step was to provide administrative forms whereby that metadata could be manipulated. This in turn led to demands for incorporating more information and more functionality into the developing application.

Electronic Resources Management Project Presentation 2012

KAUST Repository

Ramli, Rindra M.

2012-11-05

This presentation describes the electronic resources management project undertaken by the KAUST library. The objectives of this project is to migrate information from MS Sharepoint to Millennium ERM module. One of the advantages of this migration is to consolidate all electronic resources into a single and centralized location. This would allow for better information sharing among library staff.

ENCAPSULATION OF ANTITUBERCULAR DRUGS BY BIOPOLYMERS AND POLYELECTROLYTE MULTILAYERS

Directory of Open Access Journals (Sweden)

B. H. Mussabayeva

2017-01-01

Full Text Available The problem of drug-resistant tuberculosis treatment is complex and urgent: the standardof treatment includes the oral administration of six names of antibiotics, i.e. up totwenty tablets a day by the patient. This causes severe side effects, including those appeareddue to the formation of toxic products of drug interactions in the body. Therefore, itis important that some drugs dissolve in a stomach, and others – in the intestine, which willlead to increased bioavailability, reduced dosage and toxicity. The development of targeteddelivery systems for drugs with controlled release, targeted delivery and minimization ofside effects are of interest. One of the promising methods is polyelectrolytic multilayersand the technology of creating such layers by a step-by-step adsorption of heterogeneouslycharged polyelectrolytes.The aim of this article is the microencapsulation of anti-tuberculousdrugs into biopolymers coated with polyelectrolytic multilayers, and the solubilitystudy of microcapsules at pH values simulating various parts of the gastrointestinal tract.Materials and methods. Drugs as isoniazide, pyrazinamide, moxifloxacin, and biopolymers:gellan, pectin and sodium alginate, chitosan and dextran sulfate, as well as EudragitS are used to prepare microcapsules. The obtained microcapsules are studied by a methodof scanning electron microscopy. Quantitative determination of the effectiveness of the inclusionof drugs in microcapsules was carried out using pharmacopoeial methods.Results and discussion. The inclusion efficiency rises with an increase of biopolymer concentration. The inclusion efficiency increases in the row isoniazide

Production and certain properties of biopolymers used in drilling

Energy Technology Data Exchange (ETDEWEB)

Dedusenko, G Y; Gvozdyak, R I; Kolodkova, N M; Matyshevskaya, M S; Mayko, I I

1977-01-01

Biopolymers, belonging to modified polysaccharides, obtained by the action of Xanthomonas campestris bacteria on glucose and containing its substances, are used as the main component in clayless polymer muds. As a result of research performed at the laboratory of phytopathogenic bacteria in the IMV AN USSR, the producent strain of polysaccharide has been revealed and the nutritive medium chosen. Results are given of an analysis of the best Soviet samples of biopolymers created in the IMV AN USSR, produced using various strains of Xanthomonas bacteria. Rheological properties of aqueous dispersions of the biopolymer Keltsan are studied. The flow curves are recorded on the Fann rotation viscosimeter. The research performed enables determination that for fermentation can be used the bacteria Xanthomonas campestris, X. begonia, and X. molvacearum; and bacteria belonging to X. Campestris used to produce a sample batch of biopolymer, yielding the greatest amount of polysaccharide. The work results in development of a nutritive medium based on available Soviet materials, promoting formation of polysaccharide.

PRINCIPLES OF CONTENT FORMATION EDUCATIONAL ELECTRONIC RESOURCE

Directory of Open Access Journals (Sweden)

О Ю Заславская

2017-12-01

Full Text Available The article considers modern possibilities of information and communication technologies for the design of electronic educational resources. The conceptual basis of the open educational multimedia system is based on the modular architecture of the electronic educational resource. The content of the electronic training module can be implemented in several versions of the modules: obtaining information, practical exercises, control. The regularities in the teaching process in modern pedagogical theory are considered: general and specific, and the principles for the formation of the content of instruction at different levels are defined, based on the formulated regularities. On the basis of the analysis, the principles of the formation of the electronic educational resource are determined, taking into account the general and didactic patterns of teaching.As principles of the formation of educational material for obtaining information for the electronic educational resource, the article considers: the principle of methodological orientation, the principle of general scientific orientation, the principle of systemic nature, the principle of fundamentalization, the principle of accounting intersubject communications, the principle of minimization. The principles of the formation of the electronic training module of practical studies in the article include: the principle of systematic and dose based consistency, the principle of rational use of study time, the principle of accessibility. The principles of the formation of the module for monitoring the electronic educational resource can be: the principle of the operationalization of goals, the principle of unified identification diagnosis.

Dispersability of Carbon Nanotubes in Biopolymer-Based Fluids

Directory of Open Access Journals (Sweden)

Franco Tardani

2015-01-01

Full Text Available In this review the dispersability of carbon nanotubes in aqueous solutions containing proteins, or nucleic acids, is discussed. Data reported previously are complemented by unpublished ones. In the mentioned nanotube-based systems several different phases are observed, depending on the type and concentration of biopolymer, as well as the amount of dispersed nanotubes. The phase behavior depends on how much biopolymers are adsorbing, and, naturally, on the molecular details of the adsorbents. Proper modulation of nanotube/biopolymer interactions helps switching between repulsive and attractive regimes. Dispersion or phase separation take place, respectively, and the formation of liquid crystalline phases or gels may prevail with respect to dispersions. We report on systems containing ss-DNA- and lysozyme-stabilized nanotubes, representative of different organization modes. In the former case, ss-DNA rolls around CNTs and ensures complete coverage. Conversely, proteins randomly and non-cooperatively adsorb onto nanotubes. The two functionalization mechanisms are significantly different. A fine-tuning of temperature, added polymer, pH, and/or ionic strength conditions induces the formation of a given supra-molecular organization mode. The biopolymer physico-chemical properties are relevant to induce the formation of different phases made of carbon nanotubes.

Implementing CORAL: An Electronic Resource Management System

Science.gov (United States)

Whitfield, Sharon

2011-01-01

A 2010 electronic resource management survey conducted by Maria Collins of North Carolina State University and Jill E. Grogg of University of Alabama Libraries found that the top six electronic resources management priorities included workflow management, communications management, license management, statistics management, administrative…

Introduction of soft X-ray spectromicroscopy as an advanced technique for plant biopolymers research.

Directory of Open Access Journals (Sweden)

Chithra Karunakaran

Full Text Available Soft X-ray absorption spectroscopy coupled with nano-scale microscopy has been widely used in material science, environmental science, and physical sciences. In this work, the advantages of soft X-ray absorption spectromicroscopy for plant biopolymer research were demonstrated by determining the chemical sensitivity of the technique to identify common plant biopolymers and to map the distributions of biopolymers in plant samples. The chemical sensitivity of soft X-ray spectroscopy to study biopolymers was determined by recording the spectra of common plant biopolymers using soft X-ray and Fourier Transform mid Infrared (FT-IR spectroscopy techniques. The soft X-ray spectra of lignin, cellulose, and polygalacturonic acid have distinct spectral features. However, there were no distinct differences between cellulose and hemicellulose spectra. Mid infrared spectra of all biopolymers were unique and there were differences between the spectra of water soluble and insoluble xylans. The advantage of nano-scale spatial resolution exploited using soft X-ray spectromicroscopy for plant biopolymer research was demonstrated by mapping plant cell wall biopolymers in a lentil stem section and compared with the FT-IR spectromicroscopy data from the same sample. The soft X-ray spectromicroscopy enables mapping of biopolymers at the sub-cellular (~30 nm resolution whereas, the limited spatial resolution in the micron scale range in the FT-IR spectromicroscopy made it difficult to identify the localized distribution of biopolymers. The advantages and limitations of soft X-ray and FT-IR spectromicroscopy techniques for biopolymer research are also discussed.

Moisture sorption in mixtures of biopolymer, disaccharides and water

NARCIS (Netherlands)

Sman, van der R.G.M.

2013-01-01

The moisture sorption of ternary mixtures of biopolymer, sugar and water is investigated by means of the Free-Volume-Flory-Huggins (FVFH) theory. The earlier FVFH theory developed for binary mixtures of biopolymer/water and sugar/water has to be modified to account for two effects: 1) the change in

Managing electronic resources a LITA guide

CERN Document Server

Weir, Ryan O

2012-01-01

Informative, useful, current, Managing Electronic Resources: A LITA Guide shows how to successfully manage time, resources, and relationships with vendors and staff to ensure personal, professional, and institutional success.

Biopolymers to improve physical properties and leaching characteristics of mortar and concrete: A review

Science.gov (United States)

Olivia, M.; Jingga, H.; Toni, N.; Wibisono, G.

2018-04-01

The invention of environmentally friendly, high performance, and green material such as biopolymers marked an emerging trend for sustainable construction over the past decades. Biopolymer comprises of natural monomers and synthesized by plants or other organisms. The sustainable, biodegradable, and renewable biopolymers were used in concrete mixes to improve their physical and mechanical properties and durability. The aim of this paper is to provide a brief an overview of the impact of biopolymer addition into concrete and mortar mixes. Many studies on the influence of biopolymer on the properties of concrete and mortar by adding biopolymers at a certain proportion (usually less than one wt.%) to the concrete or mortar mixes, and the heavy metal leaching, rheological, and mechanical properties of the mixes were conducted. Biopolymers included in this review are chitosan (CH), xanthan gum (XG), guar gum (GG), lignosulphonate (LS), and cellulose ethers (CE). Data from previous studies showed that the addition of certain types of biopolymer into concrete and mortar mixes improve workability, water retention, and compressive strength by up to 30 percent. Chitosan strengthens heavy metal encapsulation in the mortar and neutralizes the negative impact of heavy metal on the mortar properties and environment. To sum up, the use of biopolymers improve physical properties and leaching characteristics of mortar and concrete.

Improvements in or relating to systems for measuring radioactivity of labelled biopolymers

International Nuclear Information System (INIS)

Gross, V.N.

1980-01-01

A system for measuring radioactivity of labelled biopolymers, comprises a set of containers for containing aqueous solutions of biological samples containing biopolymers; an electric drive for setting the set of containers in stepwise motion: means for acid precipitation of biopolymers arranged to provide feeding of preset volumes of a coprecipitator and a suspension of diatomite in an acid solution to the containers: means for removal of suspensions, filtering, suspending the precipitate, dissolving the biopolymers and consecutively feeding the mixture and a scintillator to a detection chamber, and a measuring cell arranged in the detection chamber. The sequence of operations is controlled automatically. (author)

Fabrication of biopolymer cantilevers using nanoimprint lithography

DEFF Research Database (Denmark)

Keller, Stephan Sylvest; Feidenhans'l, Nikolaj Agentoft; Fisker-Bødker, Nis

2011-01-01

The biodegradable polymer poly(l-lactide) (PLLA) was introduced for the fabrication of micromechanical devices. For this purpose, thin biopolymer films with thickness around 10 μm were spin-coated on silicon substrates. Patterning of microcantilevers is achieved by nanoimprint lithography. A major...... challenge was the high adhesion between PLLA and silicon stamp. Optimized stamp fabrication and the deposition of a 125 nm thick fluorocarbon anti-stiction coating on the PLLA allowed the fabrication of biopolymer cantilevers. Resonance frequency measurements were used to estimate the Young’s modulus...

Hydrogels from Biopolymer Hybrid for Biomedical, Food, and Functional Food Applications

Directory of Open Access Journals (Sweden)

Robert C. Spiro

2012-04-01

Full Text Available Hybrid hydrogels from biopolymers have been applied for various indications across a wide range of biomedical, pharmaceutical, and functional food industries. In particular, hybrid hydrogels synthesized from two biopolymers have attracted increasing attention. The inclusion of a second biopolymer strengthens the stability of resultant hydrogels and enriches its functionalities by bringing in new functional groups or optimizing the micro-environmental conditions for certain biological and biochemical processes. This article presents approaches that have been used by our groups to synthesize biopolymer hybrid hydrogels for effective uses for immunotherapy, tissue regeneration, food and functional food applications. The research has achieved some challenging results, such as stabilizing physical structure, increasing mucoadhesiveness, and the creation of an artificial extracellular matrix to aid in guiding tissue differentiation.

Designing biopolymer microgels to encapsulate, protect and deliver bioactive components: Physicochemical aspects.

Science.gov (United States)

McClements, David Julian

2017-02-01

Biopolymer microgels have considerable potential for their ability to encapsulate, protect, and release bioactive components. Biopolymer microgels are small particles (typically 100nm to 1000μm) whose interior consists of a three-dimensional network of cross-linked biopolymer molecules that traps a considerable amount of solvent. This type of particle is also sometimes referred to as a nanogel, hydrogel bead, biopolymer particles, or microsphere. Biopolymer microgels are typically prepared using a two-step process involving particle formation and particle gelation. This article reviews the major constituents and fabrication methods that can be used to prepare microgels, highlighting their advantages and disadvantages. It then provides an overview of the most important characteristics of microgel particles (such as size, shape, structure, composition, and electrical properties), and describes how these parameters can be manipulated to control the physicochemical properties and functional attributes of microgel suspensions (such as appearance, stability, rheology, and release profiles). Finally, recent examples of the utilization of biopolymer microgels to encapsulate, protect, or release bioactive agents, such as pharmaceuticals, nutraceuticals, enzymes, flavors, and probiotics is given. Copyright © 2016 Elsevier B.V. All rights reserved.

Optically controlled multiple switching operations of DNA biopolymer devices

International Nuclear Information System (INIS)

Hung, Chao-You; Tu, Waan-Ting; Lin, Yi-Tzu; Fruk, Ljiljana; Hung, Yu-Chueh

2015-01-01

We present optically tunable operations of deoxyribonucleic acid (DNA) biopolymer devices, where a single high-resistance state, write-once read-many-times memory state, write-read-erase memory state, and single low-resistance state can be achieved by controlling UV irradiation time. The device is a simple sandwich structure with a spin-coated DNA biopolymer layer sandwiched by two electrodes. Upon irradiation, the electrical properties of the device are adjusted owing to a phototriggered synthesis of silver nanoparticles in DNA biopolymer, giving rise to multiple switching scenarios. This technique, distinct from the strategy of doping of pre-formed nanoparticles, enables a post-film fabrication process for achieving optically controlled memory device operations, which provides a more versatile platform to fabricate organic memory and optoelectronic devices

Optically controlled multiple switching operations of DNA biopolymer devices

Energy Technology Data Exchange (ETDEWEB)

Hung, Chao-You; Tu, Waan-Ting; Lin, Yi-Tzu [Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Fruk, Ljiljana [Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA (United Kingdom); Hung, Yu-Chueh, E-mail: ychung@ee.nthu.edu.tw [Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

2015-12-21

We present optically tunable operations of deoxyribonucleic acid (DNA) biopolymer devices, where a single high-resistance state, write-once read-many-times memory state, write-read-erase memory state, and single low-resistance state can be achieved by controlling UV irradiation time. The device is a simple sandwich structure with a spin-coated DNA biopolymer layer sandwiched by two electrodes. Upon irradiation, the electrical properties of the device are adjusted owing to a phototriggered synthesis of silver nanoparticles in DNA biopolymer, giving rise to multiple switching scenarios. This technique, distinct from the strategy of doping of pre-formed nanoparticles, enables a post-film fabrication process for achieving optically controlled memory device operations, which provides a more versatile platform to fabricate organic memory and optoelectronic devices.

Thermal Degradation and Damping Characteristic of UV Irradiated Biopolymer

Directory of Open Access Journals (Sweden)

Anika Zafiah M. Rus

2015-01-01

Full Text Available Biopolymer made from renewable material is one of the most important groups of polymer because of its versatility in application. In this study, biopolymers based on waste vegetable oil were synthesized and cross-link with commercial polymethane polyphenyl isocyanate (known as BF. The BF was compressed by using hot compression moulding technique at 90°C based on the evaporation of volatile matter, known as compress biopolymer (CB. Treatment with titanium dioxide (TiO2 was found to affect the physical property of compressed biopolymer composite (CBC. The characterization of thermal degradation, activation energy, morphology structure, density, vibration, and damping of CB were determined after UV irradiation exposure. This is to evaluate the photo- and thermal stability of the treated CB or CBC. The vibration and damping characteristic of CBC samples is significantly increased with the increasing of UV irradiation time, lowest thickness, and percentages of TiO2 loading at the frequency range of 15–25 Hz due to the potential of the sample to dissipate energy during the oscillation harmonic system. The damping property of CBC was improved markedly upon prolonged exposure to UV irradiation.

Biocompatibility of plasma nanostructured biopolymers

Czech Academy of Sciences Publication Activity Database

Kasálková-Slepičková, N.; Slepička, P.; Bačáková, Lucie; Sajdl, P.; Švorčík, V.

2013-01-01

Roč. 307, Jul 15 (2013), s. 642-646 ISSN 0168-583X R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:67985823 Keywords : biopolymer * plasma treatment * biocompatibility Subject RIV: JJ - Other Materials Impact factor: 1.186, year: 2013

Micromechanical sensors for the measurement of biopolymer degradation

DEFF Research Database (Denmark)

Keller, Stephan Sylvest; Gammelgaard, Lene; Jensen, M P

2011-01-01

We present microcantilever-based sensors for the characterization of biopolymer degradation by enzymes. Thin films of Poly(L-lactide) (PLLA) were spray-coated onto SU-8 cantilevers with well-known material properties and dimensions. The micromechanical sensors were immersed in solutions of protei......We present microcantilever-based sensors for the characterization of biopolymer degradation by enzymes. Thin films of Poly(L-lactide) (PLLA) were spray-coated onto SU-8 cantilevers with well-known material properties and dimensions. The micromechanical sensors were immersed in solutions...

All Green Composites from Fully Renewable Biopolymers: Chitosan-Starch Reinforced with Keratin from Feathers

Directory of Open Access Journals (Sweden)

Cynthia G. Flores-Hernández

2014-03-01

Full Text Available The performance as reinforcement of a fibrillar protein such as feather keratin fiber over a biopolymeric matrix composed of polysaccharides was evaluated in this paper. Three different kinds of keratin reinforcement were used: short and long biofibers and rachis particles. These were added separately at 5, 10, 15 and 20 wt% to the chitosan-starch matrix and the composites were processed by a casting/solvent evaporation method. The morphological characteristics, mechanical and thermal properties of the matrix and composites were studied by scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry and dynamic mechanical analysis. The thermal results indicated that the addition of keratin enhanced the thermal stability of the composites compared to pure matrix. This was corroborated with dynamic mechanical analysis as the results revealed that the storage modulus of the composites increased with respect to the pure matrix. The morphology, evaluated by scanning electron microscopy, indicated a uniform dispersion of keratin in the chitosan-starch matrix as a result of good compatibility between these biopolymers, also corroborated by FTIR. These results demonstrate that chicken feathers can be useful to obtain novel keratin reinforcements and develop new green composites providing better properties, than the original biopolymer matrix.

Biopolymer Electrolyte Based on Derivatives of Cellulose from Kenaf Bast Fiber

Directory of Open Access Journals (Sweden)

Mohd Saiful Asmal Rani

2014-09-01

Full Text Available A cellulose derivative, carboxymethyl cellulose (CMC, was synthesized by the reaction of cellulose from kenaf bast fiber with monochloroacetic acid. A series of biopolymer electrolytes comprised of the synthesized CMC and ammonium acetate (CH3COONH4 were prepared by the solution-casting technique. The biopolymer-based electrolyte films were characterized by Fourier Transform Infrared spectroscopy to investigate the formation of the CMC–CH3COONH4 complexes. Electrochemical impedance spectroscopy was conducted to obtain their ionic conductivities. The highest conductivity at ambient temperature of 5.77 × 10−4 S cm−1 was obtained for the electrolyte film containing 20 wt% of CH3COONH4. The biopolymer electrolyte film also exhibited electrochemical stability up to 2.5 V. These results indicated that the biopolymer electrolyte has great potential for applications to electrochemical devices, such as proton batteries and solar cells.

Valorization of industrial waste and by-product streams via fermentation for the production of chemicals and biopolymers.

Science.gov (United States)

Koutinas, Apostolis A; Vlysidis, Anestis; Pleissner, Daniel; Kopsahelis, Nikolaos; Lopez Garcia, Isabel; Kookos, Ioannis K; Papanikolaou, Seraphim; Kwan, Tsz Him; Lin, Carol Sze Ki

2014-04-21

The transition from a fossil fuel-based economy to a bio-based economy necessitates the exploitation of synergies, scientific innovations and breakthroughs, and step changes in the infrastructure of chemical industry. Sustainable production of chemicals and biopolymers should be dependent entirely on renewable carbon. White biotechnology could provide the necessary tools for the evolution of microbial bioconversion into a key unit operation in future biorefineries. Waste and by-product streams from existing industrial sectors (e.g., food industry, pulp and paper industry, biodiesel and bioethanol production) could be used as renewable resources for both biorefinery development and production of nutrient-complete fermentation feedstocks. This review focuses on the potential of utilizing waste and by-product streams from current industrial activities for the production of chemicals and biopolymers via microbial bioconversion. The first part of this review presents the current status and prospects on fermentative production of important platform chemicals (i.e., selected C2-C6 metabolic products and single cell oil) and biopolymers (i.e., polyhydroxyalkanoates and bacterial cellulose). In the second part, the qualitative and quantitative characteristics of waste and by-product streams from existing industrial sectors are presented. In the third part, the techno-economic aspects of bioconversion processes are critically reviewed. Four case studies showing the potential of case-specific waste and by-product streams for the production of succinic acid and polyhydroxyalkanoates are presented. It is evident that fermentative production of chemicals and biopolymers via refining of waste and by-product streams is a highly important research area with significant prospects for industrial applications.

Gender Analysis Of Electronic Information Resource Use: The Case ...

African Journals Online (AJOL)

Based on the findings the study concluded that access and use of electronic information resources creates a “social digital divide” along gender lines. The study ... Finally, the library needs to change its marketing strategies on the availability of electronic information resources to increase awareness of these resources.

Nanostructure features of microalgae biopolymer

Czech Academy of Sciences Publication Activity Database

Cybulska, J.; Halaj, M.; Cepák, Vladislav; Lukavský, Jaromír; Capek, P.

2016-01-01

Roč. 68, 7-8 (2016), s. 629-636 ISSN 0038-9056 R&D Projects: GA TA ČR TE01020080; GA TA ČR TA03011027 Institutional support: RVO:67985939 Keywords : Dictyosphaerium * biopolymers * alga Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.837, year: 2016

Is there a field-theoretic explanation for precursor biopolymers?

Science.gov (United States)

Rosen, Gerald

2002-08-01

A Hu-Barkana-Gruzinov cold dark matter scalar field phi may enter a weak isospin invariant derivative interaction that causes the flow of right-handed electrons to align parallel to (inverted delta phi). Hence, in the outer regions of galaxies where (inverted delta phi) is large, as in galactic halos, the derivative interaction may induce a chirality-imbued quantum chemistry. Such a chirality-imbued chemistry would in turn be conducive to the formation of abundant precursor biopolymers on interstellar dust grains, comets and meteors in galactic halo regions, with subsequent delivery to planets in the inner galactic regions where phi and (inverted delta phi) are concomitantly near zero and left-right symmetric terrestrial quantum chemistry prevails.

Users satisfaction with electronic information resources and services ...

African Journals Online (AJOL)

This study investigated users satisfaction on the use of electronic information resources and services in MTN Net libraries in ABU & UNIBEN. Two objectives and one null hypotheses were formulated and tested with respect to the users' satisfaction on electronic information resources and services in MTN Net libraries in ...

Lithium ion conducting biopolymer electrolyte based on pectin doped with Lithium nitrate

Science.gov (United States)

Manjuladevi, R.; Selvin, P. Christopher; Selvasekarapandian, S.; Shilpa, R.; Moniha, V.

2018-04-01

The Biopolymer electrolyte based on pectin doped with lithium nitrate of different concentrations have been prepared by solution casting technique. The decrease in crystalline nature of the biopolymer has been identified by XRD analyses. The complex formation between the polymer and the salt has been revealed using FTIR analysis. The ionic conductivity has been explored using A.C. impedance spectroscopy which reveals that the biopolymer containing 30 wt% Pectin: 70wt%LiNO3 has highest ionic conductivity of 3.97 × 10-3 Scm-1.

Characterization of functional biopolymers under various external stimuli

Energy Technology Data Exchange (ETDEWEB)

Maleki, Atoosa

2008-07-01

Polymers are large molecules composed of repeating structural units connected by covalent chemical bonds. Biopolymers are a class of polymers produced by living organisms, which exhibit both biocompatible and biodegradable properties. The behavior of a biopolymer in solution is strongly dependent on the chemical and physical structure of the polymer chain, as well as external environmental conditions. To improve biopolymers in the direction of higher performance and better functionality, understanding of their physicochemical behavior and their response to external stimuli are of great importance. Rheology, rheo-small angle light scattering, dynamic light scattering, small angle neutron scattering, and asymmetric flow field-flow fractionation were utilized in this thesis to investigate the properties of hydroxyethyl cellulose and its hydrophobically modified analogue, as well as dextran, hyaluronan, and mucin under different conditions such as temperature, solvent, mechanical stress and strain, and radiation. Different novel hydrogels were prepared by using various chemical cross-linking agents. Specific features of these macromolecules provide them to be used as 'functional' materials, e.g., sensors, actuators, personal care products, enhanced oil recovery, and controlled drug delivery systems (author)

Biopolymer-Based Nanoparticles for Drug/Gene Delivery and Tissue Engineering

Science.gov (United States)

Nitta, Sachiko Kaihara; Numata, Keiji

2013-01-01

There has been a great interest in application of nanoparticles as biomaterials for delivery of therapeutic molecules such as drugs and genes, and for tissue engineering. In particular, biopolymers are suitable materials as nanoparticles for clinical application due to their versatile traits, including biocompatibility, biodegradability and low immunogenicity. Biopolymers are polymers that are produced from living organisms, which are classified in three groups: polysaccharides, proteins and nucleic acids. It is important to control particle size, charge, morphology of surface and release rate of loaded molecules to use biopolymer-based nanoparticles as drug/gene delivery carriers. To obtain a nano-carrier for therapeutic purposes, a variety of materials and preparation process has been attempted. This review focuses on fabrication of biocompatible nanoparticles consisting of biopolymers such as protein (silk, collagen, gelatin, β-casein, zein and albumin), protein-mimicked polypeptides and polysaccharides (chitosan, alginate, pullulan, starch and heparin). The effects of the nature of the materials and the fabrication process on the characteristics of the nanoparticles are described. In addition, their application as delivery carriers of therapeutic drugs and genes and biomaterials for tissue engineering are also reviewed. PMID:23344060

Biopolymer-Based Nanoparticles for Drug/Gene Delivery and Tissue Engineering

Directory of Open Access Journals (Sweden)

Keiji Numata

2013-01-01

Full Text Available There has been a great interest in application of nanoparticles as biomaterials for delivery of therapeutic molecules such as drugs and genes, and for tissue engineering. In particular, biopolymers are suitable materials as nanoparticles for clinical application due to their versatile traits, including biocompatibility, biodegradability and low immunogenicity. Biopolymers are polymers that are produced from living organisms, which are classified in three groups: polysaccharides, proteins and nucleic acids. It is important to control particle size, charge, morphology of surface and release rate of loaded molecules to use biopolymer-based nanoparticles as drug/gene delivery carriers. To obtain a nano-carrier for therapeutic purposes, a variety of materials and preparation process has been attempted. This review focuses on fabrication of biocompatible nanoparticles consisting of biopolymers such as protein (silk, collagen, gelatin, β-casein, zein and albumin, protein-mimicked polypeptides and polysaccharides (chitosan, alginate, pullulan, starch and heparin. The effects of the nature of the materials and the fabrication process on the characteristics of the nanoparticles are described. In addition, their application as delivery carriers of therapeutic drugs and genes and biomaterials for tissue engineering are also reviewed.

In vitro assessment of biopolymer-modified porous silicon microparticles for wound healing applications.

Science.gov (United States)

Mori, Michela; Almeida, Patrick V; Cola, Michela; Anselmi, Giulia; Mäkilä, Ermei; Correia, Alexandra; Salonen, Jarno; Hirvonen, Jouni; Caramella, Carla; Santos, Hélder A

2014-11-01

The wound healing stands as very complex and dynamic process, aiming the re-establishment of the damaged tissue's integrity and functionality. Thus, there is an emerging need for developing biopolymer-based composites capable of actively promoting cellular proliferation and reconstituting the extracellular matrix. The aims of the present work were to prepare and characterize biopolymer-functionalized porous silicon (PSi) microparticles, resulting in the development of drug delivery microsystems for future applications in wound healing. Thermally hydrocarbonized PSi (THCPSi) microparticles were coated with both chitosan and a mixture of chondroitin sulfate/hyaluronic acid, and subsequently loaded with two antibacterial model drugs, vancomycin and resveratrol. The biopolymer coating, drug loading degree and drug release behavior of the modified PSi microparticles were evaluated in vitro. The results showed that both the biopolymer coating and drug loading of the THCPSi microparticles were successfully achieved. In addition, a sustained release was observed for both the drugs tested. The viability and proliferation profiles of a fibroblast cell line exposed to the modified THCPSi microparticles and the subsequent reactive oxygen species (ROS) production were also evaluated. The cytotoxicity and proliferation results demonstrated less toxicity for the biopolymer-coated THCPSi microparticles at different concentrations and time points comparatively to the uncoated counterparts. The ROS production by the fibroblasts exposed to both uncoated and biopolymer-coated PSi microparticles showed that the modified PSi microparticles did not induce significant ROS production at the concentrations tested. Overall, the biopolymer-based PSi microparticles developed in this study are promising platforms for wound healing applications. Copyright © 2014 Elsevier B.V. All rights reserved.

Models of the solvent-accessible surface of biopolymers

Energy Technology Data Exchange (ETDEWEB)

Smith, R.E.

1996-09-01

Many biopolymers such as proteins, DNA, and RNA have been studied because they have important biomedical roles and may be good targets for therapeutic action in treating diseases. This report describes how plastic models of the solvent-accessible surface of biopolymers were made. Computer files containing sets of triangles were calculated, then used on a stereolithography machine to make the models. Small (2 in.) models were made to test whether the computer calculations were done correctly. Also, files of the type (.stl) required by any ISO 9001 rapid prototyping machine were written onto a CD-ROM for distribution to American companies.

Influence of Temperature on Mechanical Properties of Jute/Biopolymer Composites

DEFF Research Database (Denmark)

Løvdal, Alexandra Liv Vest; Laursen, Louise Løcke; Løgstrup Andersen, Tom

2013-01-01

Biopolymers and natural fibers are receiving wide attention for the potential to have good performance composites with low environmental impact. A current limitation of most biopolymers is however their change in mechanical properties at elevated temperatures. This study investigates the mechanical...... of the fibers. Altogether, the results demonstrate that the thermal sensitivity parameters typically provided for polymers, e.g., the glass transition temperature and the heat deflection temperature, cannot be used as sole parameters for determining the gradual change in mechanical properties of polymers...... properties of two biomass-based polymers, polylactic acid (PLA) and cellulose acetate (CA), as a function of ambient temperature in the range from 5 to 80C. Tests were done for neat polymers and for jute fiber/biopolymer composites. Micromechanical models were applied to back-calculate the reinforcement...

Biopolymer foams - Relationship between material characteristics and foaming behavior of cellulose based foams

International Nuclear Information System (INIS)

Rapp, F.; Schneider, A.; Elsner, P.

2014-01-01

Biopolymers are becoming increasingly important to both industry and consumers. With regard to waste management, CO 2 balance and the conservation of petrochemical resources, increasing efforts are being made to replace standard plastics with bio-based polymers. Nowadays biopolymers can be built for example of cellulose, lactic acid, starch, lignin or bio mass. The paper will present material properties of selected cellulose based polymers (cellulose propionate [CP], cellulose acetate butyrate [CAB]) and corresponding processing conditions for particle foams as well as characterization of produced parts. Special focus is given to the raw material properties by analyzing thermal behavior (differential scanning calorimetry), melt strength (Rheotens test) and molecular weight distribution (gel-permeation chromatography). These results will be correlated with the foaming behavior in a continuous extrusion process with physical blowing agents and underwater pelletizer. Process set-up regarding particle foam technology, including extrusion foaming and pre-foaming, will be shown. The characteristics of the resulting foam beads will be analyzed regarding part density, cell morphology and geometry. The molded parts will be tested on thermal conductivity as well as compression behavior (E-modulus, compression strength)

Biopolymer foams - Relationship between material characteristics and foaming behavior of cellulose based foams

Science.gov (United States)

Rapp, F.; Schneider, A.; Elsner, P.

2014-05-01

Biopolymers are becoming increasingly important to both industry and consumers. With regard to waste management, CO2 balance and the conservation of petrochemical resources, increasing efforts are being made to replace standard plastics with bio-based polymers. Nowadays biopolymers can be built for example of cellulose, lactic acid, starch, lignin or bio mass. The paper will present material properties of selected cellulose based polymers (cellulose propionate [CP], cellulose acetate butyrate [CAB]) and corresponding processing conditions for particle foams as well as characterization of produced parts. Special focus is given to the raw material properties by analyzing thermal behavior (differential scanning calorimetry), melt strength (Rheotens test) and molecular weight distribution (gel-permeation chromatography). These results will be correlated with the foaming behavior in a continuous extrusion process with physical blowing agents and underwater pelletizer. Process set-up regarding particle foam technology, including extrusion foaming and pre-foaming, will be shown. The characteristics of the resulting foam beads will be analyzed regarding part density, cell morphology and geometry. The molded parts will be tested on thermal conductivity as well as compression behavior (E-modulus, compression strength).

Organizational matters of competition in electronic educational resources

Directory of Open Access Journals (Sweden)

Ирина Карловна Войтович

2015-12-01

Full Text Available The article examines the experience of the Udmurt State University in conducting competitions of educational publications and electronic resources. The purpose of such competitions is to provide methodological support to educational process. The main focus is on competition of electronic educational resources. The technology of such contests is discussed through detailed analysis of the main stages of the contest. It is noted that the main task of the preparatory stage of the competition is related to the development of regulations on competition and the definition of criteria for selection of the submitted works. The paper also proposes a system of evaluation criteria of electronic educational resources developed by members of the contest organizing committee and jury members. The article emphasizes the importance of not only the preparatory stages of the competition, but also measures for its completion, aimed at training teachers create quality e-learning resources.

In planta production of ELPylated spidroin-based proteins results in non-cytotoxic biopolymers.

Science.gov (United States)

Hauptmann, Valeska; Menzel, Matthias; Weichert, Nicola; Reimers, Kerstin; Spohn, Uwe; Conrad, Udo

2015-02-19

Spider silk is a tear-resistant and elastic biopolymer that has outstanding mechanical properties. Additionally, exiguous immunogenicity is anticipated for spider silks. Therefore, spider silk represents a potential ideal biomaterial for medical applications. All known spider silk proteins, so-called spidroins, reveal a composite nature of silk-specific units, allowing the recombinant production of individual and combined segments. In this report, a miniaturized spidroin gene, named VSO1 that contains repetitive motifs of MaSp1 has been synthesized and combined to form multimers of distinct lengths, which were heterologously expressed as elastin-like peptide (ELP) fusion proteins in tobacco. The elastic penetration moduli of layered proteins were analyzed for different spidroin-based biopolymers. Moreover, we present the first immunological analysis of synthetic spidroin-based biopolymers. Characterization of the binding behavior of the sera after immunization by competitive ELISA suggested that the humoral immune response is mainly directed against the fusion partner ELP. In addition, cytocompatibility studies with murine embryonic fibroblasts indicated that recombinant spidroin-based biopolymers, in solution or as coated proteins, are well tolerated. The results show that spidroin-based biopolymers can induce humoral immune responses that are dependent on the fusion partner and the overall protein structure. Furthermore, cytocompatibility assays gave no indication of spidroin-derived cytotoxicity, suggesting that recombinant produced biopolymers composed of spider silk-like repetitive elements are suitable for biomedical applications.

Introduction of Microbial Biopolymers in Soil Treatment for Future Environmentally-Friendly and Sustainable Geotechnical Engineering

Directory of Open Access Journals (Sweden)

Ilhan Chang

2016-03-01

Full Text Available Soil treatment and improvement is commonly performed in the field of geotechnical engineering. Methods and materials to achieve this such as soil stabilization and mixing with cementitious binders have been utilized in engineered soil applications since the beginning of human civilization. Demand for environment-friendly and sustainable alternatives is currently rising. Since cement, the most commonly applied and effective soil treatment material, is responsible for heavy greenhouse gas emissions, alternatives such as geosynthetics, chemical polymers, geopolymers, microbial induction, and biopolymers are being actively studied. This study provides an overall review of the recent applications of biopolymers in geotechnical engineering. Biopolymers are microbially induced polymers that are high-tensile, innocuous, and eco-friendly. Soil–biopolymer interactions and related soil strengthening mechanisms are discussed in the context of recent experimental and microscopic studies. In addition, the economic feasibility of biopolymer implementation in the field is analyzed in comparison to ordinary cement, from environmental perspectives. Findings from this study demonstrate that biopolymers have strong potential to replace cement as a soil treatment material within the context of environment-friendly construction and development. Moreover, continuing research is suggested to ensure performance in terms of practical implementation, reliability, and durability of in situ biopolymer applications for geotechnical engineering purposes.

CHALLENGES OF ELECTRONIC INFORMATION RESOURCES IN ...

African Journals Online (AJOL)

This paper discusses the role of policy for proper and efficient library services in the electronic era. It points out some of the possible dangers of embarking in electronic resources without a proper focus at hand. Thus, it calls for today's librarians and policy makers to brainstorm and come up with working policies suitable to ...

Valorisation of CO2-rich off-gases to biopolymers through biotechnological process.

Science.gov (United States)

Garcia-Gonzalez, Linsey; De Wever, Heleen

2017-11-01

As one of the key enabling technologies, industrial biotechnology has a high potential to tackle harmful CO2 emissions and to turn CO2 into a valuable commodity. So far, experimental work mainly focused on the bioconversion of pure CO2 to chemicals and plastics and little is known about the tolerance of the bioprocesses to the presence of impurities. This work is the first to investigate the impact of real CO2-rich off-gases on autotrophic production of polyhydroxybutyrate. To this end, two-phase heterotrophic-autotrophic fermentation experiments were set up, consisting of heterothrophic cell mass growth using glucose as substrate followed by autotrophic biopolymer production using either pure synthetic CO2 or industrial off-gases sampled at two point sources. The use of real off-gases did not affect the bacterial performance. High biopolymer content (up to 73%) and productivities (up to 0.227 g/lh) were obtained. Characterisation of the polymers showed that all biopolymers had similar properties, independent of the CO2 source. Moreover, the CO2-derived biopolymers' properties were comparable to commercial ones and biopolymers reported in literature, which are all produced from organic carbon sources. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Green synthesis of silver nanoparticles and biopolymer ...

Indian Academy of Sciences (India)

2018-03-29

Mar 29, 2018 ... Keywords. Biogenic silver nanoparticles; biopolymer nanocomposites; nanoparticles stability; ... Production of nanomaterials by using living organisms of plant-based ... 2.1b Microorganisms and cell culture: The evaluation of.

Do single-use medical devices containing biopolymers reduce the environmental impacts of surgical procedures compared with their plastic equivalents?

Science.gov (United States)

Unger, Scott R; Hottle, Troy A; Hobbs, Shakira R; Thiel, Cassandra L; Campion, Nicole; Bilec, Melissa M; Landis, Amy E

2017-01-01

Background While petroleum-based plastics are extensively used in health care, recent developments in biopolymer manufacturing have created new opportunities for increased integration of biopolymers into medical products, devices and services. This study compared the environmental impacts of single-use disposable devices with increased biopolymer content versus typically manufactured devices in hysterectomy. Methods A comparative life cycle assessment of single-use disposable medical products containing plastic(s) versus the same single-use medical devices with biopolymers substituted for plastic(s) at Magee-Women's Hospital (Magee) in Pittsburgh, PA and the products used in four types of hysterectomies that contained plastics potentially suitable for biopolymer substitution. Magee is a 360-bed teaching hospital, which performs approximately 1400 hysterectomies annually. Results There are life cycle environmental impact tradeoffs when substituting biopolymers for petroplastics in procedures such as hysterectomies. The substitution of biopolymers for petroleum-based plastics increased smog-related impacts by approximately 900% for laparoscopic and robotic hysterectomies, and increased ozone depletion-related impacts by approximately 125% for laparoscopic and robotic hysterectomies. Conversely, biopolymers reduced life cycle human health impacts, acidification and cumulative energy demand for the four hysterectomy procedures. The integration of biopolymers into medical products is correlated with reductions in carcinogenic impacts, non-carcinogenic impacts and respiratory effects. However, the significant agricultural inputs associated with manufacturing biopolymers exacerbate environmental impacts of products and devices made using biopolymers. Conclusions The integration of biopolymers into medical products is correlated with reductions in carcinogenic impacts, non-carcinogenic impacts and respiratory effects; however, the significant agricultural inputs associated

Film forming microbial biopolymers for commercial applications--a review.

Science.gov (United States)

Vijayendra, S V N; Shamala, T R

2014-12-01

Microorganisms synthesize intracellular, structural and extracellular polymers also referred to as biopolymers for their function and survival. These biopolymers play specific roles as energy reserve materials, protective agents, aid in cell functioning, the establishment of symbiosis, osmotic adaptation and support the microbial genera to function, adapt, multiply and survive efficiently under changing environmental conditions. Viscosifying, gelling and film forming properties of these have been exploited for specific significant applications in food and allied industries. Intensive research activities and recent achievements in relevant and important research fields of global interest regarding film forming microbial biopolymers is the subject of this review. Microbial polymers such as pullulan, kefiran, bacterial cellulose (BC), gellan and levan are placed under the category of exopolysaccharides (EPS) and have several other functional properties including film formation, which can be used for various applications in food and allied industries. In addition to EPS, innumerable bacterial genera are found to synthesis carbon energy reserves in their cells known as polyhydroxyalkanoates (PHAs), microbial polyesters, which can be extruded into films with excellent moisture and oxygen barrier properties. Blow moldable biopolymers like PHA along with polylactic acid (PLA) synthesized chemically in vitro using lactic acid (LA), which is produced by LA bacteria through fermentation, are projected as biodegradable polymers of the future for packaging applications. Designing and creating of new property based on requirements through controlled synthesis can lead to improvement in properties of existing polysaccharides and create novel biopolymers of great commercial interest and value for wider applications. Incorporation of antimicrobials such as bacteriocins or silver and copper nanoparticles can enhance the functionality of polymer films especially in food packaging

Use of Electronic Resources in a Private University in Nigeria ...

African Journals Online (AJOL)

The study examined awareness and constraints in the use of electronic resources by lecturers and students of Ajayi Crowther University, Oyo, Nigeria. It aimed at justifying the resources expended in the provision of electronic resources in terms of awareness, patronage and factors that may be affecting awareness and use ...

Electronic Resources Management System: Recommendation Report 2017

KAUST Repository

Ramli, Rindra M.

2017-05-01

This recommendation report provides an overview of the selection process for the new Electronic Resources Management System. The library has decided to move away from Innovative Interfaces Millennium ERM module. The library reviewed 3 system as potential replacements namely: Proquest 360 Resource Manager, Ex Libris Alma and Open Source CORAL ERMS. After comparing and trialling the systems, it was decided to go for Proquest 360 Resource Manager.

Comparison of KrF and ArF excimer laser treatment of biopolymer surface

Energy Technology Data Exchange (ETDEWEB)

Michaljaničová, I. [Department of Solid State Engineering, University of Chemistry and Technology, 166 28 Prague (Czech Republic); Slepička, P., E-mail: petr.slepicka@vscht.cz [Department of Solid State Engineering, University of Chemistry and Technology, 166 28 Prague (Czech Republic); Heitz, J.; Barb, R.A. [Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria); Sajdl, P. [Department of Power Engineering, University of Chemistry and Technology, 166 28 Prague (Czech Republic); Švorčík, V. [Department of Solid State Engineering, University of Chemistry and Technology, 166 28 Prague (Czech Republic)

2015-06-01

Highlights: • The influence of ArF and KrF laser on biopolymer surface was determined. • ArF laser acts predominantly on biopolymer surface. • PHB roughness is increased similarly for both applied wavelengths. • Roughness of nanostructures can be precisely controlled. • ArF laser introduces nitrogen on PHB surface. - Abstract: The goal of this work was the investigation of the impact of two different excimer lasers on two biocompatible and biodegradable polymers (poly-L-lactide and poly hydroxybutyrate). Both polymers find usage in medical and pharmaceutical fields. The polymers were modified by KrF and ArF excimer lasers. Subsequently the impact on surface morphology, surface chemistry changes, and thermal properties was studied by means of confocal and AFM microscopy, FTIR and XPS spectroscopy and DSC calorimetry. Under the same conditions of laser treatment it was observed that ArF laser causes more significant changes on surface chemistry, surface morphology and pattern formation on the polymers under investigation. The data obtained in this work can be used for a wide range of possible applications, in tissue engineering or in combination with metallization in electronics, e.g. for biosensors.

Novel biopolymer-coated hydroxyapatite foams for removing heavy-metals from polluted water

International Nuclear Information System (INIS)

Vila, M.; Sanchez-Salcedo, S.; Cicuendez, M.; Izquierdo-Barba, I.; Vallet-Regi, Maria

2011-01-01

Highlights: → 3D-macroporous biopolymer-coated hydroxyapatite (HA) foams as potential devices for the treatment of heavy metal ions. → HA stable foams coated with biopolymers. → Feasible advance in development of new, easy to handle and low cost water purifying methods. - Abstract: 3D-macroporous biopolymer-coated hydroxyapatite (HA) foams have been developed as potential devices for the treatment of lead, cadmium and copper contamination of consumable waters. These foams have exhibited a fast and effective ion metal immobilization into the HA structure after an in vitro treatment mimicking a serious water contamination case. To improve HA foam stability at contaminated aqueous solutions pH, as well as its handling and shape integrity the 3D-macroporous foams have been coated with biopolymers polycaprolactone (PCL) and gelatine cross-linked with glutaraldehyde (G/Glu). Metal ion immobilization tests have shown higher and fast heavy metals captured as function of hydrophilicity rate of biopolymer used. After an in vitro treatment, foam morphology integrity is guaranteed and the uptake of heavy metal ions rises up to 405 μmol/g in the case of Pb 2+ , 378 μmol/g of Cu 2+ and 316 μmol/g of Cd 2+ . These novel materials promise a feasible advance in development of new, easy to handle and low cost water purifying methods.

use of electronic resources by graduate students of the department

African Journals Online (AJOL)

respondent's access electronic resources from the internet via Cybercafé .There is a high ... KEY WORDS: Use, Electronic Resources, Graduate Students, Cybercafé. INTRODUCTION ... Faculty of Education, University of Uyo, Uyo. Olu Olat ...

Extraction of cellulose microcrystalline from galam wood for biopolymer

Science.gov (United States)

Ismail, Ika; Sa'adiyah, Devy; Rahajeng, Putri; Suprayitno, Abdi; Andiana, Rocky

2018-04-01

Consumption of plastic raw materials tends to increase, but until now the meet of the consumption of plastic raw are still low, even some are still imported. Nowadays, Indonesia's plastic needs are supported by petrochemicals where raw materials are still dependent abroad and petropolymer raw materials are derived from petroleum which will soon be depleted due to rising petroleum needs. Therefore, various studies have been conducted to develop natural fiber-based polymers that are biodegradable and abundant in nature. It is because the natural polymer production process is very efficient and very environmentally friendly. There have been many studies of biopolymers especially natural fiber-based polymers from plants, due to plants containing cellulose, hemicellulose and lignin. However, cellulose is the only one who has crystalline structures. Cellulose has a high crystality compared to amorphous lignin and hemicellulose. In this study, extracted cellulose as biopolymer and amplifier on composite. The cellulose is extracted from galam wood from East Kalimantan. Cellulose extraction will be obtained in nano / micro form through chemical and mechanical treatment processes. The chemical treatment of cellulose extraction is alkalinization process using NaOH solution, bleaching using NaClO2 and acid hydrolysis using sulfuric acid. After chemical treatment, ultrasonic mechanical treatment is made to make cellulose fibers into micro or nano size. Besides, cellulose results will be characterized. Characterization was performed to analyze molecules of cellulose compounds extracted from plants using Fourier Transformation Infra Red (FTIR) testing. XRD testing to analyze cellulose crystallinity. Scanning Electron Microscope (SEM) test to analyze morphology and fiber size.

Packaging related properties of commercially available biopolymers – An overview of the status quo

Directory of Open Access Journals (Sweden)

V. Jost

2018-05-01

Full Text Available Several commercially available thermoplastic biopolymers were processed in a continuous extrusion line. The molecular weight, crystallinity, and mechanical and permeation properties of the cast films were determined in order to evaluate the status quo of biopolymers currently commercially available. The biopolymers that were evaluated were polylactic acid (PLA, several polyhydroxyalkanoates (PHAs (Poly(3-hydroxybutyrate (PHB, poly(3-hydroxybutyrate-co-4-hydroxybutyrate (PHBHB, poly(3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV, thermoplastic starch (TPS, polybutylene adipate terephthalate (PBAT, polybutylene succinate (PBS, polycaprolactone (PCL and biobased polyethylene (BioPE. Due to its potential for biobased production, thermoplastic polyurethane elastomer (TPU was also analysed. Mechanical analysis showed the PLA and PHA films had high strength and extremely low elongation at break. These were also the materials with the highest molecular weights. Films made of TPU, PCL, TPS, PBAT and BioPE had a significantly lower Young’s modulus and significantly higher elongation at break; these films had comparatively low molecular weights. Permeation measurements showed that PHA films, and particularly PHBV, had the lowest oxygen and water vapour permeability of the biopolymers that were analysed. The biopolymers BioPE, TPS, PCL, TPU and PBAT were highly permeable to oxygen, and had comparatively low molecular weight. The biopolymers TPU, PBS, PBAT, PCL and TPS were highly permeable to water vapour.

The surface properties of biopolymer-coated fruit: A review

Directory of Open Access Journals (Sweden)

Diana Cristina Moncayo Martinez

2013-09-01

Full Text Available Environmental conservation concerns have led to research and development regarding biodegradable materials from biopolymers, leading to new formulations for edible films and coatings for preserving the quality of fresh fruit and vegetables. Determining fruit skin surface properties for a given coating solution has led to predicting coating efficiency. Wetting was studied by considering spreading, adhesion and cohesion and measuring the contact angle, thus optimising the coating formulation in terms of biopolymer, plasticiser, surfactant, antimicrobial and antioxidant concentration. This work reviews the equations for determining fruit surface properties by using polar and dispersive interaction calculations and by determining the contact angle.

Electronic resource management practical perspectives in a new technical services model

CERN Document Server

Elguindi, Anne

2012-01-01

A significant shift is taking place in libraries, with the purchase of e-resources accounting for the bulk of materials spending. Electronic Resource Management makes the case that technical services workflows need to make a corresponding shift toward e-centric models and highlights the increasing variety of e-formats that are forcing new developments in the field.Six chapters cover key topics, including: technical services models, both past and emerging; staffing and workflow in electronic resource management; implementation and transformation of electronic resource management systems; the ro

Chemical modeling of acid-base properties of soluble biopolymers derived from municipal waste treatment materials.

Science.gov (United States)

Tabasso, Silvia; Berto, Silvia; Rosato, Roberta; Marinos, Janeth Alicia Tafur; Ginepro, Marco; Zelano, Vincenzo; Daniele, Pier Giuseppe; Montoneri, Enzo

2015-02-04

This work reports a study of the proton-binding capacity of biopolymers obtained from different materials supplied by a municipal biowaste treatment plant located in Northern Italy. One material was the anaerobic fermentation digestate of the urban wastes organic humid fraction. The others were the compost of home and public gardening residues and the compost of the mix of the above residues, digestate and sewage sludge. These materials were hydrolyzed under alkaline conditions to yield the biopolymers by saponification. The biopolymers were characterized by 13C NMR spectroscopy, elemental analysis and potentiometric titration. The titration data were elaborated to attain chemical models for interpretation of the proton-binding capacity of the biopolymers obtaining the acidic sites concentrations and their protonation constants. The results obtained with the models and by NMR spectroscopy were elaborated together in order to better characterize the nature of the macromolecules. The chemical nature of the biopolymers was found dependent upon the nature of the sourcing materials.

Chemical Modeling of Acid-Base Properties of Soluble Biopolymers Derived from Municipal Waste Treatment Materials

Directory of Open Access Journals (Sweden)

Silvia Tabasso

2015-02-01

Full Text Available This work reports a study of the proton-binding capacity of biopolymers obtained from different materials supplied by a municipal biowaste treatment plant located in Northern Italy. One material was the anaerobic fermentation digestate of the urban wastes organic humid fraction. The others were the compost of home and public gardening residues and the compost of the mix of the above residues, digestate and sewage sludge. These materials were hydrolyzed under alkaline conditions to yield the biopolymers by saponification. The biopolymers were characterized by 13C NMR spectroscopy, elemental analysis and potentiometric titration. The titration data were elaborated to attain chemical models for interpretation of the proton-binding capacity of the biopolymers obtaining the acidic sites concentrations and their protonation constants. The results obtained with the models and by NMR spectroscopy were elaborated together in order to better characterize the nature of the macromolecules. The chemical nature of the biopolymers was found dependent upon the nature of the sourcing materials.

Utilization of electronic information resources by academic staff at ...

African Journals Online (AJOL)

The study investigated the utilization of Electronic Information resources by the academic staff of Makerere University in Uganda. It examined the academic staff awareness of the resources available, the types of resources provided by the Makerere University Library, the factors affecting resource utilization. The study was ...

An optically transparent, flexible, patterned and conductive silk biopolymer film (Conference Presentation)

Science.gov (United States)

Umar, Muhammad; Min, Kyungtaek; Kim, Sunghwan

2017-02-01

Transparent, flexible, and conducting films are of great interest for wearable electronics. For better biotic/abiotic interface, the films to integrate the electronics components requires the patterned surface conductors with optical transparency, smoothness, good electrical conductivity, along with the biofriendly traits of films. We focus on silk fibroin, a natural biopolymer extracted from the Bombyx mori cocoons, for this bioelectronics applications. Here we report an optically transparent, flexible, and patterned surface conductor on a silk film by burying a silver nanowires (AgNW) network below the surface of the silk film. The conducting silk film reveals high optical transparency of 80% and the excellent electronic conductivity of 15 Ω/sq, along with smooth surface. The integration of light emitting diode (LED) chip on the patterned electrodes confirms that the current can flow through the transparent and patterned electrodes on the silk film, and this result shows an application for integration of functional electronic/opto-electronic devices. Additionally, we fabricate a transparent and flexible radio frequency (RF) antenna and resistor on a silk film and apply these as a food sensor by monitoring the increasing resistance by the flow of gases from the spoiled food.

Blu-Ray-based micromechanical characterization platform for biopolymer degradation assessment

DEFF Research Database (Denmark)

Casci Ceccacci, Andrea; Chen, Ching-Hsiu; Hwu, En-Te

2017-01-01

Degradable biopolymers are used as carrier materials in drug delivery devices. A complete understanding of their degradation behaviour is thus crucial in the design of new delivery systems. Here we combine a reliable method, based on spray coated micromechanical resonators and a disposable...... microfluidic chip, to characterize biopolymer degradation under the action of enzymes in controlled flow condition. The sensing platform is based on the mechanics and optics from a Blu-Ray player, which automatically localize individual sensors within the array, and sequentially measure and record...

Enzymatic functionalization of cork surface with antimicrobial hybrid biopolymer/silver nanoparticles.

Science.gov (United States)

Francesko, Antonio; Blandón, Lucas; Vázquez, Mario; Petkova, Petya; Morató, Jordi; Pfeifer, Annett; Heinze, Thomas; Mendoza, Ernest; Tzanov, Tzanko

2015-05-13

Laccase-assisted assembling of hybrid biopolymer-silver nanoparticles and cork matrices into an antimicrobial material with potential for water remediation is herein described. Amino-functional biopolymers were first used as doping agents to stabilize concentrated colloidal dispersions of silver nanoparticles (AgNP), additionally providing the particles with functionalities for covalent immobilization onto cork to impart a durable antibacterial effect. The solvent-free AgNP synthesis by chemical reduction was carried out in the presence of chitosan (CS) or 6-deoxy-6-(ω-aminoethyl) aminocellulose (AC), leading to simultaneous AgNP biofunctionalization. This approach resulted in concentrated hybrid NP dispersion stable to aggregation and with hydrodynamic radius of particles of about 250 nm. Moreover, laccase enabled coupling between the phenolic groups in cork and amino moieties in the biopolymer-doped AgNP for permanent modification of the material. The antibacterial efficiency of the functionalized cork matrices, aimed as adsorbents for wastewater treatment, was evaluated against Escherichia coli and Staphylococcus aureus during 5 days in conditions mimicking those in constructed wetlands. Both intrinsically antimicrobial CS and AC contributed to the bactericidal effect of the enzymatically grafted on cork AgNP. In contrast, unmodified AgNP were easily washed off from the material, confirming that the biopolymers potentiated a durable antibacterial functionalization of the cork matrices.

Electronic Resources Management Project Presentation 2012

KAUST Repository

Ramli, Rindra M.

2012-01-01

This presentation describes the electronic resources management project undertaken by the KAUST library. The objectives of this project is to migrate information from MS Sharepoint to Millennium ERM module. One of the advantages of this migration

Economic assessment of flash co-pyrolysis of short rotation coppice and biopolymer waste streams.

Science.gov (United States)

Kuppens, T; Cornelissen, T; Carleer, R; Yperman, J; Schreurs, S; Jans, M; Thewys, T

2010-12-01

The disposal problem associated with phytoextraction of farmland polluted with heavy metals by means of willow requires a biomass conversion technique which meets both ecological and economical needs. Combustion and gasification of willow require special and costly flue gas treatment to avoid re-emission of the metals in the atmosphere, whereas flash pyrolysis mainly results in the production of (almost) metal free bio-oil with a relatively high water content. Flash co-pyrolysis of biomass and waste of biopolymers synergistically improves the characteristics of the pyrolysis process: e.g. reduction of the water content of the bio-oil, more bio-oil and less char production and an increase of the HHV of the oil. This research paper investigates the economic consequences of the synergistic effects of flash co-pyrolysis of 1:1 w/w ratio blends of willow and different biopolymer waste streams via cost-benefit analysis and Monte Carlo simulations taking into account uncertainties. In all cases economic opportunities of flash co-pyrolysis of biomass with biopolymer waste are improved compared to flash pyrolysis of pure willow. Of all the biopolymers under investigation, polyhydroxybutyrate (PHB) is the most promising, followed by Eastar, Biopearls, potato starch, polylactic acid (PLA), corn starch and Solanyl in order of decreasing profits. Taking into account uncertainties, flash co-pyrolysis is expected to be cheaper than composting biopolymer waste streams, except for corn starch. If uncertainty increases, composting also becomes more interesting than flash co-pyrolysis for waste of Solanyl. If the investment expenditure is 15% higher in practice than estimated, the preference for flash co-pyrolysis compared to composting biopolymer waste becomes less clear. Only when the system of green current certificates is dismissed, composting clearly is a much cheaper processing technique for disposing of biopolymer waste. Copyright © 2010 Elsevier Ltd. All rights reserved.

Biosorption of strontium ions from aqueous solution using Ca-alginate biopolymer beads

International Nuclear Information System (INIS)

Goek, C.; Aytas, S.; Gerstmann, U.

2009-01-01

Biosorption of strontium ions from aqueous solution onto calcium alginate biopolymer beads was investigated in a batch system. Ca-alginate biopolymer beads were prepared from Na-alginate via cross-linking with divalent calcium ions according to the egg box model. Optimum biosorption conditions were determined as a function of initial solution pH, initial Sr concentration, contact time, biomass dosage and temperature. Langmuir, Freundlich and Dubinin-Radushkevich (D-R) models were applied to describe the biosorption isotherm of Sr ions by Ca-alginate biopolymer beads. The thermodynamic parameters (ΔH, ΔS, ΔG) for Sr sorption onto biosorbent were also determined from the temperature dependence. The results indicate that this biosorbent has a good potential for removal of Sr ions from dilute aqueous solution.

Practical guide to electronic resources in the humanities

CERN Document Server

Dubnjakovic, Ana

2010-01-01

From full-text article databases to digitized collections of primary source materials, newly emerging electronic resources have radically impacted how research in the humanities is conducted and discovered. This book, covering high-quality, up-to-date electronic resources for the humanities, is an easy-to-use annotated guide for the librarian, student, and scholar alike. It covers online databases, indexes, archives, and many other critical tools in key humanities disciplines including philosophy, religion, languages and literature, and performing and visual arts. Succinct overviews of key eme

Utilisation of Electronic Information Resources By Lecturers in ...

African Journals Online (AJOL)

This study assesses the use of information resources, specifically, electronic databases by lecturers/teachers in Universities and Colleges of Education in South Western Nigeria. Information resources are central to teachers' education. It provides lecturers/teachers access to information that enhances research and ...

Discipline, availability of electronic resources and the use of Finnish National Electronic Library - FinELib

Directory of Open Access Journals (Sweden)

Sanna Torma

2004-01-01

Full Text Available This study elaborated relations between digital library use by university faculty, users' discipline and the availability of key resources in the Finnish National Electronic Library (FinELib, Finnish national digital library, by using nationwide representative survey data. The results show that the perceived availability of key electronic resources by researchers in FinELib was a stronger predictor of the frequency and purpose of use of its services than users' discipline. Regardless of discipline a good perceived provision of central resources led to a more frequent use of FinELib. The satisfaction with the services did not vary with the discipline, but with the perceived availability of resources.

The Role of the Acquisitions Librarian in Electronic Resources Management

Science.gov (United States)

Pomerantz, Sarah B.

2010-01-01

With the ongoing shift to electronic formats for library resources, acquisitions librarians, like the rest of the profession, must adapt to the rapidly changing landscape of electronic resources by keeping up with trends and mastering new skills related to digital publishing, technology, and licensing. The author sought to know what roles…

Analysis of Pedagogic Potential of Electronic Educational Resources with Elements of Autodidactics

Directory of Open Access Journals (Sweden)

Igor A.

2018-03-01

Full Text Available Introduction: in recent years didactic properties of electronic educational resources undergo considerable changes, nevertheless, the question of studying of such complete phenomenon as “an electronic educational resource with autodidactics elements” remains open, despite sufficient scientific base of researches of the terms making this concept. Article purpose – determination of essence of electronic educational resources with autodidactics elements. Materials and Methods: the main method of research was the theoretical analysis of the pedagogical and psychological literature on the problem under study. We used the theoretical (analysis, synthesis, comparison and generalization methods, the method of interpretation, pedagogical modeling, and empirical methods (observation, testing, conversation, interview, analysis of students’ performance, pedagogical experiment, peer review. Results: we detected the advantages of electronic educational resources in comparison with traditional ones. The concept of autodidactics as applied to the subject of research is considered. Properties of electronic educational resources with a linear and nonlinear principle of construction are studied.The influence of the principle of construction on the development of the learners’ qualities is shown. We formulated an integral definition of electronic educational resources with elements of autodidactics, namely, the variability, adaptivity and cyclicity of training. A model of the teaching-learning process with electronic educational resources is developed. Discussion and Conclusions: further development of a problem will allow to define whether electronic educational resources with autodidactics elements pedagogical potential for realization of educational and self-educational activity of teachers have, to modify technological procedures taking into account age features of students, their specialties and features of the organization of process of training of

Preservation and conservation of electronic information resources of ...

African Journals Online (AJOL)

The major holdings of the broadcast libraries of the Nigerian Television Authority (NTA) are electronic information resources; therefore, providing safe places for general management of these resources have aroused interest in the industry in Nigeria for sometimes. The need to study the preservation and conservation of ...

Characterization of cross-linked porous gelatin carriers and their interaction with corneal endothelium: biopolymer concentration effect.

Directory of Open Access Journals (Sweden)

Jui-Yang Lai

Full Text Available Cell sheet-mediated tissue regeneration is a promising approach for corneal reconstruction. However, the fragility of bioengineered corneal endothelial cell (CEC monolayers allows us to take advantage of cross-linked porous gelatin hydrogels as cell sheet carriers for intraocular delivery. The aim of this study was to further investigate the effects of biopolymer concentrations (5-15 wt% on the characteristic and safety of hydrogel discs fabricated by a simple stirring process combined with freeze-drying method. Results of scanning electron microscopy, porosity measurements, and ninhydrin assays showed that, with increasing solid content, the pore size, porosity, and cross-linking index of carbodiimide treated samples significantly decreased from 508±30 to 292±42 µm, 59.8±1.1 to 33.2±1.9%, and 56.2±1.6 to 34.3±1.8%, respectively. The variation in biopolymer concentrations and degrees of cross-linking greatly affects the Young's modulus and swelling ratio of the gelatin carriers. Differential scanning calorimetry measurements and glucose permeation studies indicated that for the samples with a highest solid content, the highest pore wall thickness and the lowest fraction of mobile water may inhibit solute transport. When the biopolymer concentration is in the range of 5-10 wt%, the hydrogels have high freezable water content (0.89-0.93 and concentration of permeated glucose (591.3-615.5 µg/ml. These features are beneficial to the in vitro cultivation of CECs without limiting proliferation and changing expression of ion channel and pump genes such as ATP1A1, VDAC2, and AQP1. In vivo studies by analyzing the rabbit CEC morphology and count also demonstrate that the implanted gelatin discs with the highest solid content may cause unfavorable tissue-material interactions. It is concluded that the characteristics of cross-linked porous gelatin hydrogel carriers and their triggered biological responses are in relation to biopolymer

Building an electronic resource collection a practical guide

CERN Document Server

Lee, Stuart D

2004-01-01

This practical book guides information professionals step-by-step through building and managing an electronic resource collection. It outlines the range of electronic products currently available in abstracting and indexing, bibliographic, and other services and then describes how to effectively select, evaluate and purchase them.

Biopolymer-based material used in optical image correlation

Czech Academy of Sciences Publication Activity Database

Mysliwiec, J.; Kochalska, Anna; Miniewicz, A.

2008-01-01

Roč. 47, č. 11 (2008), s. 1902-1906 ISSN 0003-6935 Institutional research plan: CEZ:AV0Z40500505 Keywords : biopolymer * DNA * optical correlation Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.763, year: 2008

Liquid crystalline biopolymers: A new arena for liquid crystal research

International Nuclear Information System (INIS)

Rizvi, Tasneem Zahra

2001-07-01

This paper gives a brief introduction to liquid crystals on the basis of biopolymers and reviews literature on liquid crystalline behaviour of biopolymers both in vitro and in vivo in relation to their implications in the fields of biology, medicine and material science. Knowledge in the field of biological liquid crystals is crucial for understanding complex phenomena at supramolecular level which will give information about processes involved in biological organization and function. The understanding of the interaction of theses crystals with electric, magnetic, optical and thermal fields will uncover mechanisms of near quantum-energy detection capabilities of biosystems

Analysis of Human Resources Management Strategy in China Electronic Commerce Enterprises

Science.gov (United States)

Shao, Fang

The paper discussed electronic-commerce's influence on enterprise human resources management, proposed and proved the human resources management strategy which electronic commerce enterprise should adopt from recruitment strategy to training strategy, keeping talent strategy and other ways.

Using XML Technologies to Organize Electronic Reference Resources

OpenAIRE

Huser, Vojtech; Del Fiol, Guilherme; Rocha, Roberto A.

2005-01-01

Provision of access to reference electronic resources to clinicians is becoming increasingly important. We have created a framework for librarians to manage access to these resources at an enterprise level, rather than at the individual hospital libraries. We describe initial project requirements, implementation details, and some preliminary results.

Significance of collective motions in biopolymers and neutron scattering

Energy Technology Data Exchange (ETDEWEB)

Go, Nobuhiro [Kyoto Univ. (Japan)

1996-05-01

Importance of collective variable description of conformational dynamics of biopolymers and the vital role that neutron inelastic scattering phenomena would play in its experimental determination are discussed. (author)

Electronic Resources and Mission Creep: Reorganizing the Library for the Twenty-First Century

Science.gov (United States)

Stachokas, George

2009-01-01

The position of electronic resources librarian was created to serve as a specialist in the negotiation of license agreements for electronic resources, but mission creep has added more functions to the routine work of electronic resources such as cataloging, gathering information for collection development, and technical support. As electronic…

The Effect of Sodium Hydroxide on Drag Reduction using a Biopolymer.

Directory of Open Access Journals (Sweden)

Singh Harvin Kaur A/P Gurchran

2014-07-01

Full Text Available Drag reduction is observed as reduced frictional pressure losses under turbulent flow conditions and hence, substantially increases the flowrate of the fluid. Practical application includes water flooding system, pipeline transport and drainage system. Drag reduction agent, such as polymers, can be introduced to increase the flowrate of water flowing, reducing the water accumulation in the system and subsequently lesser possibility of heavy flooding. Currently used polymer as drag reduction agents is carboxymethylcellulose, to name one. This is a synthetic polymer which will seep into the ground and further harm our environment in excessive use of accumulation. A more environmentally-friendly drag reduction agent, such as the polymer derived from natural sources or biopolymer, is then required for such purpose. As opposed to the synthetic polymers, the potential of biopolymers as drag reduction agents, especially those derived from a local plant source, are not extensively explored. The drag reduction of a polymer produced from a local plant source within the turbulent regime will be explored and assessed in this study using a rheometer where a reduced a torque produced can be perceived as a reduction of drag. The cellulose powder was converted to carboxymethylcellulose (CMC by etherification process using sodium monochloroacetate and sodium hydroxide. The carboxymethylation reaction then was optimized against concentration of NaOH. The research is structured to focus on producing the biopolymer and also assess the drag reduction ability of the biopolymer produced against concentration of sodium hydroxide.

Electronic Resources Management System: Recommendation Report 2017

KAUST Repository

Ramli, Rindra M.

2017-01-01

This recommendation report provides an overview of the selection process for the new Electronic Resources Management System. The library has decided to move away from Innovative Interfaces Millennium ERM module. The library reviewed 3 system

Effect on tomato plant and fruit of the application of biopolymer-oregano essential oil coatings.

Science.gov (United States)

Perdones, Ángela; Tur, Núria; Chiralt, Amparo; Vargas, Maria

2016-10-01

Oregano essential oil (EO) was incorporated into film-forming dispersions (FFDs) based on biopolymers (chitosan and/or methylcellulose) at two different concentrations. The effect of the application of the FFDs was evaluated on tomato plants (cultivar Micro-Tom) at three different stages of development, and on pre-harvest and postharvest applications on tomato fruit. The application of the FFDs at '3 Leaves' stage caused phytotoxic problems, which were lethal when the EO was applied without biopolymers. Even though plant growth and development were delayed, the total biomass and the crop yield were not affected by biopolymer-EO treatments. When the FFDs were applied in the 'Fruit' stage the pre-harvest application of FFDs had no negative effects. All FFDs containing EO significantly reduced the respiration rate of tomato fruit and diminished weight loss during storage. Moreover, biopolymer-EO FFDs led to a decrease in the fungal decay of tomato fruit inoculated with Rhizopus stolonifer spores, as compared with non-treated tomato fruit and those coated with FFDs without EO. The application of biopolymer-oregano essential oil coatings has been proven to be an effective treatment to control R. stolonifer in tomato fruit. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Polyhydroxybutyrate (PHB) Synthesis by Spirulina sp. LEB 18 Using Biopolymer Extraction Waste.

Science.gov (United States)

da Silva, Cleber Klasener; Costa, Jorge Alberto Vieira; de Morais, Michele Greque

2018-01-20

The reuse of waste as well as the production of biodegradable compounds has for years been the object of studies and of global interest as a way to reduce the environmental impact generated by unsustainable exploratory processes. The conversion of linear processes into cyclical processes has environmental and economic advantages, reducing waste deposition and reducing costs. The objective of this work was to use biopolymer extraction waste in the cultivation of Spirulina sp. LEB 18, for the cyclic process of polyhydroxybutyrate (PHB) synthesis. Concentrations of 10, 15, 20, 25, and 30% (v/v) of biopolymer extraction waste were tested. For comparison, two assays were used without addition of waste, Zarrouk (SZ) and modified Zarrouk (ZM), with reduction of nitrogen. The assays were carried out in triplicate and evaluated for the production of microalgal biomass and PHB. The tests with addition of waste presented a biomass production statistically equal to ZM (0.79 g L -1 ) (p PHB in the assay containing 25% of waste was higher when compared to the other cultivations, obtaining 10.6% (w/w) of biopolymer. From the results obtained, it is affirmed that the use of PHB extraction waste in the microalgal cultivation, aiming at the synthesis of biopolymers, can occur in a cyclic process, reducing process costs and the deposition of waste, thus favoring the preservation of the environment.

Using computer simulations to probe the structure and dynamics of biopolymers

International Nuclear Information System (INIS)

Levy, R.M.; Hirata, F.; Kim, K.; Zhang, P.

1987-01-01

The use of computer simulations to study internal motions and thermodynamic properties is receiving increased attention. One important use of the method is to provide a more fundamental understanding of the molecular information contained in various kinds of experiments on these complex systems. In the first part of this paper the authors review recent work in their laboratory concerned with the use of computer simulations for the interpretation of experimental probes of molecular structure and dynamics of proteins and nucleic acids. The interplay between computer simulations and three experimental techniques is emphasized: (1) nuclear magnetic resonance relaxation spectroscopy, (2) refinement of macro-molecular x-ray structures, and (3) vibrational spectroscopy. The treatment of solvent effects in biopolymer simulations is a difficult problem. It is not possible to study systematically the effect of solvent conditions, e.g. added salt concentration, on biopolymer properties by means of simulations alone. In the last part of the paper the authors review a more analytical approach they developed to study polyelectrolyte properties of solvated biopolymers. The results are compared with computer simulations

The Internet School of Medicine: use of electronic resources by medical trainees and the reliability of those resources.

Science.gov (United States)

Egle, Jonathan P; Smeenge, David M; Kassem, Kamal M; Mittal, Vijay K

2015-01-01

Electronic sources of medical information are plentiful, and numerous studies have demonstrated the use of the Internet by patients and the variable reliability of these sources. Studies have investigated neither the use of web-based resources by residents, nor the reliability of the information available on these websites. A web-based survey was distributed to surgical residents in Michigan and third- and fourth-year medical students at an American allopathic and osteopathic medical school and a Caribbean allopathic school regarding their preferred sources of medical information in various situations. A set of 254 queries simulating those faced by medical trainees on rounds, on a written examination, or during patient care was developed. The top 5 electronic resources cited by the trainees were evaluated for their ability to answer these questions accurately, using standard textbooks as the point of reference. The respondents reported a wide variety of overall preferred resources. Most of the 73 responding medical trainees favored textbooks or board review books for prolonged studying, but electronic resources are frequently used for quick studying, clinical decision-making questions, and medication queries. The most commonly used electronic resources were UpToDate, Google, Medscape, Wikipedia, and Epocrates. UpToDate and Epocrates had the highest percentage of correct answers (47%) and Wikipedia had the lowest (26%). Epocrates also had the highest percentage of wrong answers (30%), whereas Google had the lowest percentage (18%). All resources had a significant number of questions that they were unable to answer. Though hardcopy books have not been completely replaced by electronic resources, more than half of medical students and nearly half of residents prefer web-based sources of information. For quick questions and studying, both groups prefer Internet sources. However, the most commonly used electronic resources fail to answer clinical queries more than half

Effect of Cross-Linking on the Performances of Starch-Based Biopolymer as Gel Electrolyte for Dye-Sensitized Solar Cell Applications

Directory of Open Access Journals (Sweden)

Pavithra Nagaraj

2017-12-01

Full Text Available Dye-sensitized solar cells (DSSCs have become a validated and economically credible competitor to the traditional solid-state junction photovoltaic devices. DSSCs based on biopolymer gel electrolyte systems offer the perspective of competitive conversion efficiencies with a very low-cost fabrication. In this paper, a new starch-based biopolymer gel electrolyte system is prepared by mixing lithium iodide and iodine with bare and citric acid cross-linked potato starches with glycerol as the plasticizing agent. The effect of the preparation methods on the starch cross-linking degree as well as the photoconversion efficiency of the resulting DSSC cells is carefully analyzed. Fourier transform spectroscopy, X-ray diffraction, and scanning electron microscopy were used to characterize the morphology and conformational changes of starch in the electrolytes. The conductivity of the biopolymer electrolytes was determined by electrochemical impedance spectroscopy. DSSC based on the starch-gel polymer electrolytes were characterized by photovoltaic measurements and electrochemical impedance spectroscopy. Results clearly show that the cross-linking increases the recombination resistance and open circuit voltage (VOC of the DSSC, and thereby the photoconversion efficiency of the cell. In particular, electrolytes containing 1.4 g bare and cross-linked starches showed ionic conductivities of σ = 1.61, 0.59, 0.38, and 0.35 S cm−1, and the corresponding DSSCs showed efficiencies of 1.2, 1.4, 0.93, and 1.11%, respectively.

Corrosion Inhibition of High Speed Steel by Biopolymer HPMC Derivatives

Directory of Open Access Journals (Sweden)

Shih-Chen Shi

2016-07-01

Full Text Available The corrosion inhibition characteristics of the derivatives of biopolymer hydroxypropyl methylcellulose (HPMC, hydroxypropyl methylcellulose phthalate (HPMCP, and hydroxypropyl methylcellulose acetate succinate (HPMCAS film are investigated. Based on electrochemical impedance spectroscopic measurements and potentiodynamic polarization, the corrosion inhibition performance of high speed steel coated with HPMC derivatives is evaluated. The Nyquist plot and Tafel polarization demonstrate promising anti-corrosion performance of HPMC and HPMCP. With increasing film thickness, both materials reveal improvement in corrosion inhibition. Moreover, because of a hydrophobic surface and lower moisture content, HPMCP shows better anti-corrosion performance than HPMCAS. The study is of certain importance for designing green corrosion inhibitors of high speed steel surfaces by the use of biopolymer derivatives.

ANALYTICAL REVIEW OF ELECTRONIC RESOURCES FOR THE STUDY OF LATIN

Directory of Open Access Journals (Sweden)

Olena Yu. Balalaieva

2014-04-01

Full Text Available The article investigates the current state of development of e-learning content in the Latin language. It is noted that the introduction of ICT in the educational space has expanded the possibility of studying Latin, opened access to digital libraries resources, made it possible to use scientific and educational potential and teaching Latin best practices of world's leading universities. A review of foreign and Ukrainian information resources and electronic editions for the study of Latin is given. Much attention was paid to the didactic potential of local and online multimedia courses of Latin, electronic textbooks, workbooks of interactive tests and exercises, various dictionaries and software translators, databases and digital libraries. Based on analysis of the world market of educational services and products the main trends in the development of information resources and electronic books are examined. It was found that multimedia courses with interactive exercises or workbooks with interactive tests, online dictionaries and translators are the most widely represented and demanded. The noticeable lagging of Ukrainian education and computer linguistics in quantitative and qualitative measures in this industry is established. The obvious drawback of existing Ukrainian resources and electronic editions for the study of Latin is their noninteractive nature. The prospects of e-learning content in Latin in Ukraine are outlined.

Effective Energy Methods for Global Optimization for Biopolymer Structure Prediction

National Research Council Canada - National Science Library

Shalloway, David

1998-01-01

.... Its main strength is that it uncovers and exploits the intrinsic "hidden structures" of biopolymer energy landscapes to efficiently perform global minimization using a hierarchical search procedure...

Elektronik Bilgi Kaynaklarının Seçimi / Selection of Electronic Information Resources

Directory of Open Access Journals (Sweden)

Pınar Al

2003-04-01

Full Text Available For many years, library users have used only from the printed media in order to get the information that they have needed. Today with the widespread use of the Web and the addition of electronic information resources to library collections, the use of information in the electronic environment as well as in printed media is started to be used. In time, such types of information resources as, electronic journals, electronic books, electronic encyclopedias, electronic dictionaries and electronic theses have been added to library collections. In this study, selection criteria that can be used for electronic information resources are discussed and suggestions are provided for libraries that try to select electronic information resources for their collections.

Electrospun Chitosan-Gelatin Biopolymer Composite Nanofibers for Horseradish Peroxidase Immobilization in a Hydrogen Peroxide Biosensor

Directory of Open Access Journals (Sweden)

Siriwan Teepoo

2017-10-01

Full Text Available A biosensor based on chitosan-gelatin composite biopolymers nanofibers is found to be effective for the immobilization of horseradish peroxidase to detect hydrogen peroxide. The biopolymer nanofibers were fabricated by an electrospining technique. Upon optimization of synthesis parameters, biopolymers nanofibers, an average of 80 nm in diameter, were obtained and were then modified on the working electrode surface. The effects of the concentration of enzyme, pH, and concentration of the buffer and the working potential on the current response of the nanofibers-modified electrode toward hydrogen peroxide were optimized to obtain the maximal current response. The results found that horseradish peroxidase immobilization on chitosan-gelatin composite biopolymer nanofibers had advantages of fast response, excellent reproducibility, high stability, and showed a linear response to hydrogen peroxide in the concentration range from 0.1 to 1.7 mM with a detection limit of 0.05 mM and exhibited high sensitivity of 44 µA∙mM−1∙cm−2. The developed system was evaluated for analysis of disinfectant samples and showed good agreement between the results obtained by the titration method without significant differences at the 0.05 significance level. The proposed strategy based on chitosan-gelatin composite biopolymer nanofibers for the immobilization of enzymes can be extended for the development of other enzyme-based biosensors.

Integrated bioconversion of syngas into bioethanol and biopolymers.

Science.gov (United States)

Lagoa-Costa, Borja; Abubackar, Haris Nalakath; Fernández-Romasanta, María; Kennes, Christian; Veiga, María C

2017-09-01

Syngas bioconversion is a promising method for bioethanol production, but some VFA remains at the end of fermentation. A two-stage process was set-up, including syngas fermentation as first stage under strict anaerobic conditions using C. autoethanogenum as inoculum, with syngas (CO/CO 2 /H 2 /N 2 , 30/10/20/40) as gaseous substrate. The second stage consisted in various fed-batch assays using a highly enriched PHA accumulating biomass as inoculum, where the potential for biopolymer production from the remaining acetic acid at the end of the syngas fermentation was evaluated. All of the acetic acid was consumed and accumulated as biopolymer, while ethanol and 2,3-butanediol remained basically unused. It can be concluded that a high C/N ratio in the effluent from the syngas fermentation stage was responsible for non-consumption of alcohols. A maximum PHA content of 24% was reached at the end of the assay. Copyright © 2017 Elsevier Ltd. All rights reserved.

Access to electronic resources by visually impaired people

Directory of Open Access Journals (Sweden)

Jenny Craven

2003-01-01

Full Text Available Research into access to electronic resources by visually impaired people undertaken by the Centre for Research in Library and Information Management has not only explored the accessibility of websites and levels of awareness in providing websites that adhere to design for all principles, but has sought to enhance understanding of information seeking behaviour of blind and visually impaired people when using digital resources.

Segregative phase separation in aqueous mixtures of polydisperse biopolymers

NARCIS (Netherlands)

Edelman, M.W.

2003-01-01

Keywords: biopolymer, gelatine, dextran, PEO, phase separation, polydispersity, molar mass distribution, SEC-MALLS, CSLM The temperature-composition phase diagram of aqueous solutions of gelatine and dextran, which show liquid/liquid phase segregation, were explored at temperatures above the

Wetting of biopolymer coatings: contact angle kinetics and image analysis investigation.

Science.gov (United States)

Farris, Stefano; Introzzi, Laura; Biagioni, Paolo; Holz, Torsten; Schiraldi, Alberto; Piergiovanni, Luciano

2011-06-21

The surface wetting of five biopolymers, used as coating materials for a plastic film, was monitored over a span of 8 min by means of the optical contact angle technique. Because most of the total variation was observed to occur during the first 60 s, we decided to focus on this curtailed temporal window. Initial contact angle values (θ(0)) ranged from ∼91° for chitosan to ∼30° for pullulan. However, the water drop profile began to change immediately following drop deposition for all biocoatings, confirming that the concept of water contact angle equilibrium is not applicable to most biopolymers. First, a three-parameter decay equation [θ(t) = θ(0) exp(kt(n))] was fit to the experimental contact angle data to describe the kinetics of the contact angle change for each biocoating. Interestingly, the k constant correlated well with the contact angle evolution rate and the n exponent seemed to be somehow linked to the physicochemical phenomena underlying the overall kinetics process. Second, to achieve a reliable description of droplet evolution, the contact angle (CA) analysis was coupled with image analysis (IA) through a combined geometric/trigonometric approach. Absorption and spreading were the key factors governing the overall mechanism of surface wetting during the 60 s analysis, although the individual quantification of both phenomena demonstrated that spreading provided the largest contribution for all biopolymers, with the only exception of gelatin, which showed two quasi-equivalent and counterbalancing effects. The possible correlation between these two phenomena and the topography of the biopolymer surfaces are then discussed on the basis of atomic force microscopy analyses. © 2011 American Chemical Society

Library training to promote electronic resource usage

DEFF Research Database (Denmark)

Frandsen, Tove Faber; Tibyampansha, Dativa; Ibrahim, Glory

2017-01-01

Purpose: Increasing the usage of electronic resources is an issue of concern for many libraries all over the world. Several studies stress the importance of information literacy and instruction in order to increase the usage. Design/methodology/approach: The present article presents the results...

Why and How to Measure the Use of Electronic Resources

Directory of Open Access Journals (Sweden)

Jean Bernon

2008-11-01

Full Text Available A complete overview of library activity implies a complete and reliable measurement of the use of both electronic resources and printed materials. This measurement is based on three sets of definitions: document types, use types and user types. There is a common model of definitions for printed materials, but a lot of questions and technical issues remain for electronic resources. In 2006 a French national working group studied these questions. It relied on the COUNTER standard, but found it insufficient and pointed out the need for local tools such as web markers and deep analysis of proxy logs. Within the French national consortium COUPERIN, a new working group is testing ERMS, SUSHI standards, Shibboleth authentication, along with COUNTER standards, to improve the counting of the electronic resources use. At this stage this counting is insufficient and its improvement will be a European challenge for the future.

Incorporation of zinc oxide to dispersions of biopolymers and release of the metallic ion in vitro; Incorporacao de oxido de zinco a dispersoes de biopolimeros e liberacao do ion metalico in vitro

Energy Technology Data Exchange (ETDEWEB)

Barreto, Marina S.R.; Ferreira, Willian H.; Andrade, Cristina T., E-mail: marinarodriguesbarreto@gmail.com [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil)

2015-07-01

Zinc oxide (ZnO) nanoparticles, obtained from a commercial product, were dispersed in different biopolymers, to be added to piglet feeds. The resulting products, prepared with sodium alginate (SA), chitosan (CH) and low methoxyl pectin (LMP) were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The release of Zn{sup 2+} was investigated under simulated conditions of the gastrointestinal tract of piglets, and analyzed by atomic absorption spectroscopy (AA). The results showed that the structural factors, which have influence on the biopolymer/ZnO interactions, govern the behavior of Zn{sup 2+} release. (author)

Parallelized system for biopolymer degradation studies through automated microresonator measurement in liquid flow

DEFF Research Database (Denmark)

Casci Ceccacci, Andrea; Morelli, Lidia; Bosco, Filippo

2015-01-01

setup unit, the system allows high-throughput measurements of resonance frequency over microresonator arrays under controlled flow conditions. We here demonstrate the acquisition of statistical data on biopolymer films degradation under enzymatic reaction over a large sample of micromechanical......In this work we present a novel automated system which allows the study of enzymatic degradation of biopolymer films coated on micromechanical resonators. The system combines an optical readout based on Blu-Ray technology with a software-controlled scanning mechanism. Integrated with a microfluidic...

The Influence of Biopolym FTZ on the Content of Nitrogen Compounds in Rumen

OpenAIRE

Eva Petrášková; Jana Hnisová; Bohuslav Čermák; Šoch Miloslav; Bohuslav Vostoupal

2010-01-01

The aim of this study was to verify the effect of Biopolym FZT on the crude protein in the ruminal content. The experiment was conducted in laboratory conditions. Rumen content was removed from the Holstein breed cow fitted with ruminal fistula. The hydrolyzed brown seaweed was added to the samples of the ruminal content. After incubation of the samples the crude protein content was determined. In experiments with solid ruminal contents positive effects of Biopolym on the crude protein conten...

Achieving biopolymer synergy in systems chemistry.

Science.gov (United States)

Bai, Yushi; Chotera, Agata; Taran, Olga; Liang, Chen; Ashkenasy, Gonen; Lynn, David G

2018-05-31

Synthetic and materials chemistry initiatives have enabled the translation of the macromolecular functions of biology into synthetic frameworks. These explorations into alternative chemistries of life attempt to capture the versatile functionality and adaptability of biopolymers in new orthogonal scaffolds. Information storage and transfer, however, so beautifully represented in the central dogma of biology, require multiple components functioning synergistically. Over a single decade, the emerging field of systems chemistry has begun to catalyze the construction of mutualistic biopolymer networks, and this review begins with the foundational small-molecule-based dynamic chemical networks and peptide amyloid-based dynamic physical networks on which this effort builds. The approach both contextualizes the versatile approaches that have been developed to enrich chemical information in synthetic networks and highlights the properties of amyloids as potential alternative genetic elements. The successful integration of both chemical and physical networks through β-sheet assisted replication processes further informs the synergistic potential of these networks. Inspired by the cooperative synergies of nucleic acids and proteins in biology, synthetic nucleic-acid-peptide chimeras are now being explored to extend their informational content. With our growing range of synthetic capabilities, structural analyses, and simulation technologies, this foundation is radically extending the structural space that might cross the Darwinian threshold for the origins of life as well as creating an array of alternative systems capable of achieving the progressive growth of novel informational materials.

Euler European Libraries and Electronic Resources in Mathematical Sciences

CERN Document Server

The Euler Project. Karlsruhe

The European Libraries and Electronic Resources (EULER) Project in Mathematical Sciences provides the EulerService site for searching out "mathematical resources such as books, pre-prints, web-pages, abstracts, proceedings, serials, technical reports preprints) and NetLab (for Internet resources), this outstanding engine is capable of simple, full, and refined searches. It also offers a browse option, which responds to entries in the author, keyword, and title fields. Further information about the Project is provided at the EULER homepage.

The cross-linking influence of electromagnetic radiation on water-soluble polyacrylan compositions with biopolymers

Directory of Open Access Journals (Sweden)

B. Grabowska

2009-01-01

Full Text Available The results of examinations of the cross-linking influence of electromagnetic radiation - in a microwave range – on polyacrylancompositions with biopolymers, are presented in the hereby paper. The cross-linking process of the tested compositions was determined on the basis of the FT-IR spectroscopic methods. It was shown that microwave operations can lead to the formation of new cross-linkedstructures with strong covalent bonds. The adsorption process and formation of active centres in polymer molecules as well as in highsilica sand were found due to microwave radiations. In this process hydroxyl groups (-OH - present in a polymer - and silane groups (Si- O-H - present in a matrix - are mainly taking part. Spectroscopic and strength tests performed for the system: biopolymer binding agent – matrix indicate that the microwave radiation can be applied for hardening moulding sands with biopolymer binders.

Rheology of Biopolymer Solutions and Gels

Directory of Open Access Journals (Sweden)

David R. Picout

2003-01-01

Full Text Available Rheological techniques and methods have been employed for many decades in the characterization of polymers. Originally developed and used on synthetic polymers, rheology has then found much interest in the field of natural (bio polymers. This review concentrates on introducing the fundamentals of rheology and on discussing the rheological aspects and properties of the two major classes of biopolymers: polysaccharides and proteins. An overview of both their solution properties (dilute to semi-dilute and gel properties is described.

Effect of Different Purification Techniques on the Characteristics of Heteropolysaccharide-Protein Biopolymer from Durian (Durio zibethinus Seed

Directory of Open Access Journals (Sweden)

Hamed Mirhosseini

2012-09-01

Full Text Available Natural biopolymers from plant sources contain many impurities (e.g., fat, protein, fiber, natural pigment and endogenous enzymes, therefore, an efficient purification process is recommended to minimize these impurities and consequently improve the functional properties of the biopolymer. The main objective of the present study was to investigate the effect of different purification techniques on the yield, protein content, solubility, water- and oil-holding capacity of a heteropolysaccharide-protein biopolymer obtained from durian seed. Four different purification methods using different chemicals and solvents (i.e., A (isopropanol and ethanol, B (isopropanol and acetone, C (saturated barium hydroxide, and D (Fehling solution] to liberate the purified biopolymer from its crude form were compared. In most cases, the purification process significantly (p < 0.05 improved the physicochemical properties of heteropolysaccharide-protein biopolymer from durian fruit seed. The present work showed that the precipitation using isopropanol and acetone (Method B resulted in the highest purification yield among all the tested purification techniques. The precipitation using saturated barium hydroxide (Method C led to induce the highest solubility and relatively high capacity of water absorption. The current study reveals that the precipitation using Fehling solution (Method D most efficiently eliminates the protein fraction, thus providing more pure biopolymer suitable for biological applications.

Effects of Electronic Information Resources Skills Training for Lecturers on Pedagogical Practices and Research Productivity

Science.gov (United States)

Bhukuvhani, Crispen; Chiparausha, Blessing; Zuvalinyenga, Dorcas

2012-01-01

Lecturers use various electronic resources at different frequencies. The university library's information literacy skills workshops and seminars are the main sources of knowledge of accessing electronic resources. The use of electronic resources can be said to have positively affected lecturers' pedagogical practices and their work in general. The…

Silk fibroin/gold nanocrystals: a new example of biopolymer-based nanocomposites

Science.gov (United States)

Noinville, S.; Garnier, A.; Courty, A.

2017-05-01

The dispersion of nanoparticles in ordered polymer nanostructures can provide control over particle location and orientation, and pave the way for tailored nanomaterials that have enhanced mechanical, electrical, or optical properties. Here we used silk fibroin, a natural biopolymer, to embed gold nanocrystals (NCs), so as to obtain well-ordered structures such as nanowires and self-assembled triangular nanocomposites. Monodisperse gold NCs synthesized in organic media are mixed to silk fibroin and the obtained nanocomposites are characterized by UV-visible spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (FE-SEM), atomic force microscopy (AFM) and Infrared spectroscopy. The optical properties study of gold NCs and silk-gold nanocomposites shows that the Surface Plasmon band is blue shifted compared to gold NCs. The size and shape of NCs gold superlattices can be well controlled by the presence of silk fibroin giving nanowires and also self-assembled triangular nanocomposites as characterized by TEM, FE-SEM and AFM. The strong interaction between gold NCs and silk fibroin is also revealed by the conformation change of silk protein in presence of gold NCs, as shown by FTIR analysis. The formation of such ordered nanocomposites (gold NCs/silk fibroin) will provide new nanoplasmonic devices.

Mechanics of biopolymer materials: Single chains to bulk properties

NARCIS (Netherlands)

Amuasi, H.E.; Storm, C.

2010-01-01

We outline the first stages in the multiscale modeling of biopolymer materials, starting with the statistical mechanics of single stiff chains. In the first coarse graining step, we demonstrate how to integrate out the single polymer degrees of freedom in supramolecular assemblies of such

Smart swelling biopolymer microparticles by a microfluidic approach: synthesis, in situ encapsulation and controlled release.

Science.gov (United States)

Fang, Aiping; Cathala, Bernard

2011-01-01

This paper reports a microfluidic synthesis of biopolymer microparticles aiming at smart swelling. Monodisperse aqueous emulsion droplets comprising biopolymer and its cross-linking agent were formed in mineral oil and solidified in the winding microfluidic channels by in situ chaotic mixing, which resulted in internal chemical gelation for hydrogels. The achievement of pectin microparticles from in situ mixing pectin with its cross-linking agent, calcium ions, successfully demonstrates the reliability of this microfluidic synthesis approach. In order to achieve hydrogels with smart swelling, the following parameters and their impacts on the swelling behaviour, stability and morphology of microparticles were investigated: (1) the type of biopolymers (alginate or mixture of alginate and carboxymethylcellulose, A-CMC); (2) rapid mixing; (3) concentration and type of cross-linking agent. Superabsorbent microparticles were obtained from A-CMC mixture by using ferric chloride as an additional external cross-linking agent. The in situ encapsulation of a model protein, bovine serum albumin (BSA), was also carried out. As a potential protein drug-delivery system, the BSA release behaviours of the biopolymer particles were studied in simulated gastric and intestinal fluids. Compared with alginate and A-CMC microparticles cross-linked with calcium ions, A-CMC microparticles cross-linked with both calcium and ferric ions demonstrate a significantly delayed release. The controllable release profile, the facile encapsulation as well as their biocompatibility, biodegradability, mucoadhesiveness render this microfluidic approach promising in achieving biopolymer microparticles as protein drug carrier for site-specific release. Copyright © 2010 Elsevier B.V. All rights reserved.

BIOREFINE-2G — Result In Brief: Novel biopolymers from biorefinery waste-streams

DEFF Research Database (Denmark)

Stovicek, Vratislav; Chen, Xiao; Borodina, Irina

Second generation biorefineries are all about creating value from waste, so it seems only right that the ideal plant should leave nothing behind. With this in mind, the BIOREFINE-2G project has developed novel processes to convert pentose-rich side-streams into biopolymers.......Second generation biorefineries are all about creating value from waste, so it seems only right that the ideal plant should leave nothing behind. With this in mind, the BIOREFINE-2G project has developed novel processes to convert pentose-rich side-streams into biopolymers....

Boletus edulis biologically active biopolymers induce cell cycle arrest in human colon adenocarcinoma cells.

Science.gov (United States)

Lemieszek, Marta Kinga; Cardoso, Claudia; Ferreira Milheiro Nunes, Fernando Hermínio; Ramos Novo Amorim de Barros, Ana Isabel; Marques, Guilhermina; Pożarowski, Piotr; Rzeski, Wojciech

2013-04-25

The use of biologically active compounds isolated from edible mushrooms against cancer raises global interest. Anticancer properties are mainly attributed to biopolymers including mainly polysaccharides, polysaccharopeptides, polysaccharide proteins, glycoproteins and proteins. In spite of the fact that Boletus edulis is one of the widely occurring and most consumed edible mushrooms, antitumor biopolymers isolated from it have not been exactly defined and studied so far. The present study is an attempt to extend this knowledge on molecular mechanisms of their anticancer action. The mushroom biopolymers (polysaccharides and glycoproteins) were extracted with hot water and purified by anion-exchange chromatography. The antiproliferative activity in human colon adenocarcinoma cells (LS180) was screened by means of MTT and BrdU assays. At the same time fractions' cytotoxicity was examined on the human colon epithelial cells (CCD 841 CoTr) by means of the LDH assay. Flow cytometry and Western blotting were applied to cell cycle analysis and protein expression involved in anticancer activity of the selected biopolymer fraction. In vitro studies have shown that fractions isolated from Boletus edulis were not toxic against normal colon epithelial cells and in the same concentration range elicited a very prominent antiproliferative effect in colon cancer cells. The best results were obtained in the case of the fraction designated as BE3. The tested compound inhibited cancer cell proliferation which was accompanied by cell cycle arrest in the G0/G1-phase. Growth inhibition was associated with modulation of the p16/cyclin D1/CDK4-6/pRb pathway, an aberration of which is a critical step in the development of many human cancers including colon cancer. Our results indicate that a biopolymer BE3 from Boletus edulis possesses anticancer potential and may provide a new therapeutic/preventive option in colon cancer chemoprevention.

Hydration water dynamics in biopolymers from NMR relaxation in the rotating frame.

Science.gov (United States)

Blicharska, Barbara; Peemoeller, Hartwig; Witek, Magdalena

2010-12-01

Assuming dipole-dipole interaction as the dominant relaxation mechanism of protons of water molecules adsorbed onto macromolecule (biopolymer) surfaces we have been able to model the dependences of relaxation rates on temperature and frequency. For adsorbed water molecules the correlation times are of the order of 10(-5)s, for which the dispersion region of spin-lattice relaxation rates in the rotating frame R(1)(ρ)=1/T(1)(ρ) appears over a range of easily accessible B(1) values. Measurements of T(1)(ρ) at constant temperature and different B(1) values then give the "dispersion profiles" for biopolymers. Fitting a theoretical relaxation model to these profiles allows for the estimation of correlation times. This way of obtaining the correlation time is easier and faster than approaches involving measurements of the temperature dependence of R(1)=1/T(1). The T(1)(ρ) dispersion approach, as a tool for molecular dynamics study, has been demonstrated for several hydrated biopolymer systems including crystalline cellulose, starch of different origins (potato, corn, oat, wheat), paper (modern, old) and lyophilized proteins (albumin, lysozyme). Copyright © 2010 Elsevier Inc. All rights reserved.

Electronic Commerce Resource Centers. An Industry--University Partnership.

Science.gov (United States)

Gulledge, Thomas R.; Sommer, Rainer; Tarimcilar, M. Murat

1999-01-01

Electronic Commerce Resource Centers focus on transferring emerging technologies to small businesses through university/industry partnerships. Successful implementation hinges on a strategic operating plan, creation of measurable value for customers, investment in customer-targeted training, and measurement of performance outputs. (SK)

Overview of biopolymers as carriers of antiphlogistic agents for treatment of diverse ocular inflammations.

Science.gov (United States)

Sharma, Anil Kumar; Arya, Amit; Sahoo, Pravat Kumar; Majumdar, Dipak Kanti

2016-10-01

Inflammation of the eye is a usual clinical condition that can implicate any part of the eye. The nomenclature of variety of such inflammations is based on the ocular part involved. These diseases may jeopardize normal functioning of the eye on progression. In general, corticosteroids, antihistamines, mast cell stabilizers and non-steroidal anti-inflammatory drugs (NSAIDs) are used to treat inflammatory diseases/disorders of the eye. There have been several attempts via different approaches of drug delivery to overcome the low ocular bioavailability resulting from shorter ocular residence time. The features like safety, ease of elimination and ability to sustain drug release have led to application of biopolymers in ocular therapeutics. Numerous polymers of natural origin such as gelatin, collagen, chitosan, albumin, hyaluronic acid, alginates etc. have been successfully employed for preparation of different ocular dosage forms. Chitosan is the most explored biopolymer amongst natural biopolymers because of its inherent characteristics. The emergence of synthetic biopolymers (like PVP, PACA, PCL, POE, polyanhydrides, PLA, PGA and PLGA) has also added new dimensions to the drug delivery strategies meant for treatment of ophthalmic inflammations. The current review is an endeavor to describe the utility of a variety of biomaterials/polymers based drug delivery systems as carrier for anti-inflammatory drugs in ophthalmic therapeutics. Copyright © 2016 Elsevier B.V. All rights reserved.

Enzyme and metabolic engineering for the production of novel biopolymers: crossover of biological and chemical processes.

Science.gov (United States)

Matsumoto, Ken'ichiro; Taguchi, Seiichi

2013-12-01

The development of synthetic biology has transformed microbes into useful factories for producing valuable polymers and/or their precursors from renewable biomass. Recent progress at the interface of chemistry and biology has enabled the production of a variety of new biopolymers with properties that substantially differ from their petroleum-derived counterparts. This review touches on recent trials and achievements in the field of biopolymer synthesis, including chemo-enzymatically synthesized aliphatic polyesters, wholly biosynthesized lactate-based polyesters, polyhydroxyalkanoates and other unusual bacterially synthesized polyesters. The expanding diversities in structure and the material properties of biopolymers are key for exploring practical applications. The enzyme and metabolic engineering approaches toward this goal are discussed by shedding light on the successful case studies. Copyright © 2013 Elsevier Ltd. All rights reserved.

A review of combined experimental and computational procedures for assessing biopolymer structure-process-property relationships.

Science.gov (United States)

Gronau, Greta; Krishnaji, Sreevidhya T; Kinahan, Michelle E; Giesa, Tristan; Wong, Joyce Y; Kaplan, David L; Buehler, Markus J

2012-11-01

Tailored biomaterials with tunable functional properties are desirable for many applications ranging from drug delivery to regenerative medicine. To improve the predictability of biopolymer materials functionality, multiple design parameters need to be considered, along with appropriate models. In this article we review the state of the art of synthesis and processing related to the design of biopolymers, with an emphasis on the integration of bottom-up computational modeling in the design process. We consider three prominent examples of well-studied biopolymer materials - elastin, silk, and collagen - and assess their hierarchical structure, intriguing functional properties and categorize existing approaches to study these materials. We find that an integrated design approach in which both experiments and computational modeling are used has rarely been applied for these materials due to difficulties in relating insights gained on different length- and time-scales. In this context, multiscale engineering offers a powerful means to accelerate the biomaterials design process for the development of tailored materials that suit the needs posed by the various applications. The combined use of experimental and computational tools has a very broad applicability not only in the field of biopolymers, but can be exploited to tailor the properties of other polymers and composite materials in general. Copyright © 2012 Elsevier Ltd. All rights reserved.

A review of combined experimental and computational procedures for assessing biopolymer structure–process–property relationships

Science.gov (United States)

Gronau, Greta; Krishnaji, Sreevidhya T.; Kinahan, Michelle E.; Giesa, Tristan; Wong, Joyce Y.; Kaplan, David L.; Buehler, Markus J.

2013-01-01

Tailored biomaterials with tunable functional properties are desirable for many applications ranging from drug delivery to regenerative medicine. To improve the predictability of biopolymer materials functionality, multiple design parameters need to be considered, along with appropriate models. In this article we review the state of the art of synthesis and processing related to the design of biopolymers, with an emphasis on the integration of bottom-up computational modeling in the design process. We consider three prominent examples of well-studied biopolymer materials – elastin, silk, and collagen – and assess their hierarchical structure, intriguing functional properties and categorize existing approaches to study these materials. We find that an integrated design approach in which both experiments and computational modeling are used has rarely been applied for these materials due to difficulties in relating insights gained on different length- and time-scales. In this context, multiscale engineering offers a powerful means to accelerate the biomaterials design process for the development of tailored materials that suit the needs posed by the various applications. The combined use of experimental and computational tools has a very broad applicability not only in the field of biopolymers, but can be exploited to tailor the properties of other polymers and composite materials in general. PMID:22938765

Self-(Un)rolling Biopolymer Microstructures: Rings, Tubules, and Helical Tubules from the Same Material.

Science.gov (United States)

Ye, Chunhong; Nikolov, Svetoslav V; Calabrese, Rossella; Dindar, Amir; Alexeev, Alexander; Kippelen, Bernard; Kaplan, David L; Tsukruk, Vladimir V

2015-07-13

We have demonstrated the facile formation of reversible and fast self-rolling biopolymer microstructures from sandwiched active-passive, silk-on-silk materials. Both experimental and modeling results confirmed that the shape of individual sheets effectively controls biaxial stresses within these sheets, which can self-roll into distinct 3D structures including microscopic rings, tubules, and helical tubules. This is a unique example of tailoring self-rolled 3D geometries through shape design without changing the inner morphology of active bimorph biomaterials. In contrast to traditional organic-soluble synthetic materials, we utilized a biocompatible and biodegradable biopolymer that underwent a facile aqueous layer-by-layer (LbL) assembly process for the fabrication of 2D films. The resulting films can undergo reversible pH-triggered rolling/unrolling, with a variety of 3D structures forming from biopolymer structures that have identical morphology and composition. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of Graphene Nanoplatelets on the Physical and Antimicrobial Properties of Biopolymer-Based Nanocomposites

Directory of Open Access Journals (Sweden)

Roberto Scaffaro

2016-05-01

Full Text Available In this work, biopolymer-based nanocomposites with antimicrobial properties were prepared via melt-compounding. In particular, graphene nanoplatelets (GnPs as fillers and an antibiotic, i.e., ciprofloxacin (CFX, as biocide were incorporated in a commercial biodegradable polymer blend of poly(lactic acid (PLA and a copolyester (BioFlex®. The prepared materials were characterized by scanning electron microscopy (SEM, and rheological and mechanical measurements. Moreover, the effect of GnPs on the antimicrobial properties and release kinetics of CFX was evaluated. The results indicated that the incorporation of GnPs increased the stiffness of the biopolymeric matrix and allowed for the tuning of the release of CFX without hindering the antimicrobial activity of the obtained materials.

The estimation of harmfulness for environment of moulding sand with biopolymer binder based on polylactide

Directory of Open Access Journals (Sweden)

K. Major-Gabryś

2011-01-01

Full Text Available The article takes into consideration technological and ecological aspects of IV generation moulding sands. Investigations concerning anapplication of biopolymer materials as binders for moulding sands are presented in the paper. These investigations are the continuation ofexaminations related to applications of various biopolymers as binding agents and to the properties of the moulding sands with biopolymerbinders. In the paper there are the researches concerning analyzing gases emitted from moulding sands during heating.

The Influence of Biopolym FTZ on the Content of Nitrogen Compounds in Rumen

Directory of Open Access Journals (Sweden)

Eva Petrášková

2010-05-01

Full Text Available The aim of this study was to verify the effect of Biopolym FZT on the crude protein in the ruminal content. The experiment was conducted in laboratory conditions. Rumen content was removed from the Holstein breed cow fitted with ruminal fistula. The hydrolyzed brown seaweed was added to the samples of the ruminal content. After incubation of the samples the crude protein content was determined. In experiments with solid ruminal contents positive effects of Biopolym on the crude protein content was shown. The best results were achieved at the dilution of 1:2000.

Biosurfactant-biopolymer driven microbial enhanced oil recovery (MEOR) and its optimization by an ANN-GA hybrid technique.

Science.gov (United States)

Dhanarajan, Gunaseelan; Rangarajan, Vivek; Bandi, Chandrakanth; Dixit, Abhivyakti; Das, Susmita; Ale, Kranthikiran; Sen, Ramkrishna

2017-08-20

A lipopeptide biosurfactant produced by marine Bacillus megaterium and a biopolymer produced by thermophilic Bacillus licheniformis were tested for their application potential in the enhanced oil recovery. The crude biosurfactant obtained after acid precipitation effectively reduced the surface tension of deionized water from 70.5 to 28.25mN/m and the interfacial tension between lube oil and water from 18.6 to 1.5mN/m at a concentration of 250mgL -1 . The biosurfactant exhibited a maximum emulsification activity (E 24 ) of 81.66% against lube oil. The lipopeptide micelles were stabilized by addition of Ca 2+ ions to the biosurfactant solution. The oil recovery efficiency of Ca 2+ conditioned lipopeptide solution from a sand-packed column was optimized by using artificial neural network (ANN) modelling coupled with genetic algorithm (GA) optimization. Three important parameters namely lipopeptide concentration, Ca 2+ concentration and solution pH were considered for optimization studies. In order to further improve the recovery efficiency, a water soluble biopolymer produced by Bacillus licheniformis was used as a flooding agent after biosurfactant incubation. Upon ANN-GA optimization, 45% tertiary oil recovery was achieved, when biopolymer at a concentration of 3gL -1 was used as a flooding agent. Oil recovery was only 29% at optimal conditions predicted by ANN-GA, when only water was used as flooding solution. The important characteristics of biopolymers such as its viscosity, pore plugging capabilities and bio-cementing ability have also been tested. Thus, as a result of biosurfactant incubation and biopolymer flooding under the optimal process conditions, a maximum oil recovery of 45% was achieved. Therefore, this study is novel, timely and interesting for it showed the combined influence of biosurfactant and biopolymer on solubilisation and mobilization of oil from the soil. Copyright © 2017 Elsevier B.V. All rights reserved.

A Vegetal Biopolymer-Based Biostimulant Promoted Root Growth in Melon While Triggering Brassinosteroids and Stress-Related Compounds

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Luigi Lucini

2018-04-01

Full Text Available Plant biostimulants are receiving great interest for boosting root growth during the first phenological stages of vegetable crops. The present study aimed at elucidating the morphological, physiological, and metabolomic changes occurring in greenhouse melon treated with the biopolymer-based biostimulant Quik-link, containing lateral root promoting peptides, and lignosulphonates. The vegetal-based biopolymer was applied at five rates (0, 0.06, 0.12, 0.24, or 0.48 mL plant-1 as substrate drench. The application of biopolymer-based biostimulant at 0.12 and 0.24 mL plant-1 enhanced dry weight of melon leaves and total biomass by 30.5 and 27.7%, respectively, compared to biopolymer applications at 0.06 mL plant-1 and untreated plants. The root dry biomass, total root length, and surface in biostimulant-treated plants were significantly higher at 0.24 mL plant-1 and to a lesser extent at 0.12 and 0.48 mL plant-1, in comparison to 0.06 mL plant-1 and untreated melon plants. A convoluted biochemical response to the biostimulant treatment was highlighted through UHPLC/QTOF-MS metabolomics, in which brassinosteroids and their interaction with other hormones appeared to play a pivotal role. Root metabolic profile was more markedly altered than leaves, following application of the biopolymer-based biostimulant. Brassinosteroids triggered in roots could have been involved in changes of root development observed after biostimulant application. These hormones, once transported to shoots, could have caused an hormonal imbalance. Indeed, the involvement of abscisic acid, cytokinins, and gibberellin related compounds was observed in leaves following root application of the biopolymer-based biostimulant. Nonetheless, the treatment triggered an accumulation of several metabolites involved in defense mechanisms against biotic and abiotic stresses, such as flavonoids, carotenoids, and glucosinolates, thus potentially improving resistance toward plant stresses.

The Effect of Multidentate Biopolymer Based on Polyacrylamide Grafted onto Kappa-Carrageenan on the Spectrofluorometric Properties of Water-Soluble CdS Quantum Dots

Directory of Open Access Journals (Sweden)

Ghasem Rezanejade Bardajee

2011-01-01

Full Text Available A new fluorescent composite based on CdS quantum dots immobilized on the multidentate biopolymer matrix is prepared through the graft copolymerization of the acrylamide onto kappa-Carrageenan. A variety of techniques like thermogravimetric analysis (TGA, transmission electron microscopy (TEM, and Fourier transform infrared spectroscopy (FT-IR was used to confirm the structure of the obtained samples. To investigate the spectrofluorometric properties, fluorescence spectroscopy of the obtained quantum dots was studied.

Biopolymers and its aplication on environment

Directory of Open Access Journals (Sweden)

Sonia Ospina

2015-07-01

Full Text Available The use of disposable packaging has made the world million tons of non-biodegradable waste generated . For many years we used non-biodegradable , petroleum plastic packaging . Belatedly we have realized that to continue this rate of contamination, soon ocasionaremos irreparable damage to the environment . It is therefore all efforts on seeking alternatives to the use of non-biodegradable packaging, are of great importance , in order to restore the damaged environment so far, and prevent deterioration onwards. In this regard , research in different areas of biotechnology has allowed the production of biodegradable packaging produced from microbial biopolymers.

Bioactivity of noble metal nanoparticles decorated with biopolymers and their application in drug delivery.

Science.gov (United States)

Rai, Mahendra; Ingle, Avinash P; Gupta, Indarchand; Brandelli, Adriano

2015-12-30

The unique properties of nanomaterials can be applied to solve different problems including new ways of drug delivery. Noble metal nanoparticles are most promising because they have been used for medicinal purposes since ancient time. It is evident from the past studies that the metallic nanoparticles are much more effective against various microorganisms when compared to their conventional counterparts. However, decoration of such nanoparticles with biomaterials add more advantages to their antimicrobial activity. Decoration of metal nanoparticles with biopolymers is a quite new area of research. Studies performed hitherto shown that nanoparticles of noble metals like silver, gold and platinum demonstrated better antibacterial, antifungal and antiviral activities when conjugated with biopolymers. The development of such technology has potential to develop materials that are more effective in the field of health science. Considering the importance and uniqueness of this concept, the present review aims to discuss the use of biopolymer-decorated metal nanoparticles for combating various diseases caused by microbial pathogens. Moreover, the nanotoxicity aspect has also been discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

Biological Effects of Spirulina (Arthrospira Biopolymers and Biomass in the Development of Nanostructured Scaffolds

Directory of Open Access Journals (Sweden)

Michele Greque de Morais

2014-01-01

Full Text Available Spirulina is produced from pure cultures of the photosynthetic prokaryotic cyanobacteria Arthrospira. For many years research centers throughout the world have studied its application in various scientific fields, especially in foods and medicine. The biomass produced from Spirulina cultivation contains a variety of biocompounds, including biopeptides, biopolymers, carbohydrates, essential fatty acids, minerals, oligoelements, and sterols. Some of these compounds are bioactive and have anti-inflammatory, antibacterial, antioxidant, and antifungal properties. These compounds can be used in tissue engineering, the interdisciplinary field that combines techniques from cell science, engineering, and materials science and which has grown in importance over the past few decades. Spirulina biomass can be used to produce polyhydroxyalkanoates (PHAs, biopolymers that can substitute synthetic polymers in the construction of engineered extracellular matrices (scaffolds for use in tissue cultures or bioactive molecule construction. This review describes the development of nanostructured scaffolds based on biopolymers extracted from microalgae and biomass from Spirulina production. These scaffolds have the potential to encourage cell growth while reducing the risk of organ or tissue rejection.

USE OF ELECTRONIC EDUCATIONAL RESOURCES WHEN TRAINING IN WORK WITH SPREADSHEETS

Directory of Open Access Journals (Sweden)

Х А Гербеков

2017-12-01

Full Text Available Today the tools for maintaining training courses based on opportunities of information and communication technologies are developed. Practically in all directions of preparation and on all subject matters electronic textbook and self-instruction manuals are created. Nevertheless the industry of computer educational and methodical materials actively develops and gets more and more areas of development and introduction. In this regard more and more urgent is a problem of development of the electronic educational resources adequate to modern educational requirements. Creation and the organization of training courses with use of electronic educational resources in particular on the basis of Internet technologies remains a difficult methodical task.In article the questions connected with development of electronic educational resources for use when studying the substantial line “Information technologies” of a school course of informatics in particular for studying of spreadsheets are considered. Also the analysis of maintenance of a school course and the unified state examination from the point of view of representation of task in him corresponding to the substantial line of studying “Information technologies” on mastering technology of information processing in spreadsheets and the methods of visualization given by means of charts and schedules is carried out.

Spatially resolved microrheology of heterogeneous biopolymer hydrogels using covalently bound microspheres

NARCIS (Netherlands)

Wong, L.H.; Kurniawan, Nicholas A.; Too, H.-P.; Rajagopalan, R.

2014-01-01

Characterization of the rheological properties of heterogeneous biopolymers is important not only to understand the effect of substrate elasticity on cell behaviors, but also to provide insights into mechanical changes during cellular remodeling of the environment. Conventional particle-tracking

Biopolymers production with carbon source from the wastes of a beer brewery industry

Science.gov (United States)

Wong, Phoeby Ai Ling

The main purpose of this study was to assess the potential and feasibility of malt wastes, and other food wastes, such as soy wastes, ice-cream wastes, confectionery wastes, vinegar wastes, milk waste and sesame oil, in the induction of biosynthesis of PHA, in the cellular assembly of novel PHA with improved physical and chemical properties, and in the reduction of the cost of PHA production. In the first part of the experiments, a specific culture of Alcaligenes latus DSM 1124 was selected to ferment several types of food wastes as carbon sources into biopolymers. In addition, the biopolymer production, by way of using malt waste, of microorganisms from municipal activated sludge was also investigated. In the second part, the experiments focused on the synthesis of biopolymer with a higher molecular mass via the bacterial strain, which was selected and isolated from sesame oil, identified as Staphylococcus epidermidis . Molecular weight and molecular weight distribution of PHB were studied by GPC. Molecular weight of PHB produced from various types of food wastes by Alcaligenes latus was higher than using synthetic sucrose medium as nutrient, however, it resulted in the reverse by Staphylococcus epidermidis. Thermal properties of biopolymers were studied by DSC and TG. Using malt wastes as nutrients by Alcaligenes latus gave a higher melting temperature. Using sucrose, confectionery and sesame oil as nutrients by Staphylococcus epidermidis gave higher melting temperature. Optimization was carried out for the recovery of microbial PHB from Alcaligenes latus. Results showed that molecular weight can be controlled by changing the hypochlorite concentration, the ratio of chloroform to hypochlorite solution and the extraction time. In addition, the determination of PHB content by thermogravimetric analysis method with wet cell was the first report in our study. (Abstract shortened by UMI.)

Biopolymer electrolytes based on blend of kappa-carrageenan and cellulose derivatives for potential application in dye sensitized solar cell

International Nuclear Information System (INIS)

Rudhziah, S.; Ahmad, A.; Ahmad, I.; Mohamed, N.S.

2015-01-01

In this work, carboxymethyl kappa-carrageenan was used as the principle host for developing new biopolymer electrolytes based on the blend of carboxymethyl kappa-carrageenan/carboxymethyl cellulose. The blending of carboxymethyl cellulose into carboxymethyl kappa-carragenan was found to be a promising strategy to improve the material properties such as conductive properties. The electrolyte samples were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, dynamic mechanical analysis, electrochemical impedance spectroscopy, ionic transference number measurement and linear sweep voltammetry in order to investigate their structural, thermal and electrochemical properties. Impedance study showed that the ionic conductivity increased with the increment of ammonium iodide concentration. The highest room temperature ionic conductivity achieved was 2.41 × 10 −3 S cm −1 at 30 wt% of the salt. The increment of conductivity was due to the increase of formation of transient cross-linking between the carboxymethyl kappa-carrageenan/carboxymethyl cellulose chains and the doping salt as indicated the T g trend. The conductivity was also attributed by the increase in the number of charge carriers in the biopolymer electrolytes system. The interactions between polymers and salt were confirmed by FTIR study. The transference number measurements showed that the conductivity was predominantly ionic. Temperature dependent conductivity study showed that conductivity increased with the reciprocal of temperature. The conductivity-temperature plots suggested that the conductivity obeyed the Vogel–Tammann–Fulcher relation and the activation energy for the best conducting sample was 0.010 eV. This system was used for the fabrication of dye sensitized solar cells, FTO/TiO 2 -dye/CMKC/CMCE-NH 4 I + I 2 /Pt. The fabricated cell showed response under light intensity of 100 mW cm −2 with efficiency of 0.13% indicating that the blend biopolymer

Inhibition of calcification of bovine pericardium after treatment with biopolymers, E-beam irradiation and in vitro endothelization

International Nuclear Information System (INIS)

Polak, Roberta; Rodas, Andrea C.D.; Chicoma, Dennis L.; Giudici, Reinaldo; Beppu, Marisa M.; Higa, Olga Z.; Pitombo, Ronaldo N.M.

2013-01-01

This work has investigated the in vitro calcification of bovine pericardium (BP) treated with chitosan (C), silk fibroin (SF) and electron beam irradiation after its endothelization in vitro. For this purpose, freeze-dried BP membranes treated with mixtures of C and SF (1:3, 1:1 and 3:1) and then irradiated by electron beam irradiation were seeded with human umbilical vein endothelial cells (HUVEC) in vitro. After 3 weeks of cultivation these membranes were submitted to in vitro calcification tests using simulated body fluid as the calcifying agent. Control membranes were also studied (without endothelial cells exposure). The results have shown that the membrane compatibility with HUVECs in vitro prevent such biomaterial from calcifying, showing a potential application in biomaterial area, such as cardiac valves and repair patches. - Highlights: ► Bovine pericardium tissue treated with biopolymers followed by electron beam irradiation could be endothelized in vitro ► Calcification was inhibited after endothelization, demonstrating a new anti calcifying treatment for BP membranes ► This membranes could be used as cardiac valves and repair patches.

Inhibition of calcification of bovine pericardium after treatment with biopolymers, E-beam irradiation and in vitro endothelization

Energy Technology Data Exchange (ETDEWEB)

Polak, Roberta [Department of Biochemical and Pharmaceutical Technology, School of Pharmaceutical Sciences, University of Sao Paulo, USP, Sao Paulo, SP (Brazil); Rodas, Andrea C.D. [Biotechnology Center, Energy and Nuclear Research Institute, IPEN-CNEN/SP, Sao Paulo, SP (Brazil); Chicoma, Dennis L.; Giudici, Reinaldo [Department of Chemical Engineering of Polytechnic School, University of Sao Paulo, SP (Brazil); Beppu, Marisa M. [School of Chemical Engineering, University of Campinas, UNICAMP, Campinas, SP (Brazil); Higa, Olga Z. [Biotechnology Center, Energy and Nuclear Research Institute, IPEN-CNEN/SP, Sao Paulo, SP (Brazil); Pitombo, Ronaldo N.M., E-mail: pitombo@usp.br [Department of Biochemical and Pharmaceutical Technology, School of Pharmaceutical Sciences, University of Sao Paulo, USP, Sao Paulo, SP (Brazil)

2013-01-01

This work has investigated the in vitro calcification of bovine pericardium (BP) treated with chitosan (C), silk fibroin (SF) and electron beam irradiation after its endothelization in vitro. For this purpose, freeze-dried BP membranes treated with mixtures of C and SF (1:3, 1:1 and 3:1) and then irradiated by electron beam irradiation were seeded with human umbilical vein endothelial cells (HUVEC) in vitro. After 3 weeks of cultivation these membranes were submitted to in vitro calcification tests using simulated body fluid as the calcifying agent. Control membranes were also studied (without endothelial cells exposure). The results have shown that the membrane compatibility with HUVECs in vitro prevent such biomaterial from calcifying, showing a potential application in biomaterial area, such as cardiac valves and repair patches. - Highlights: Black-Right-Pointing-Pointer Bovine pericardium tissue treated with biopolymers followed by electron beam irradiation could be endothelized in vitro Black-Right-Pointing-Pointer Calcification was inhibited after endothelization, demonstrating a new anti calcifying treatment for BP membranes Black-Right-Pointing-Pointer This membranes could be used as cardiac valves and repair patches.

Analytical Study of Usage of Electronic Information Resources at Pharmacopoeial Libraries in India

Directory of Open Access Journals (Sweden)

Sunil Tyagi

2014-02-01

Full Text Available The objective of this study is to know the rate and purpose of the use of e-resource by the scientists at pharmacopoeial libraries in India. Among other things, this study examined the preferences of the scientists toward printed books and journals, electronic information resources, and pattern of using e-resources. Non-probability sampling specially accidental and purposive technique was applied in the collection of primary data through administration of user questionnaire. The sample respondents chosen for the study consists of principle scientific officer, senior scientific officer, scientific officer, and scientific assistant of different division of the laboratories, namely, research and development, pharmaceutical chemistry, pharmacovigilance, pharmacology, pharmacogonosy, and microbiology. The findings of the study reveal the personal experiences and perceptions they have had on practice and research activity using e-resource. The major findings indicate that of the total anticipated participants, 78% indicated that they perceived the ability to use computer for electronic information resources. The data analysis shows that all the scientists belonging to the pharmacopoeial libraries used electronic information resources to address issues relating to drug indexes and compendia, monographs, drugs obtained through online databases, e-journals, and the Internet sources—especially polices by regulatory agencies, contacts, drug promotional literature, and standards.

BIOLOGICAL NANOPORES FOR BIOPOLYMER SENSING AND SEQUENCING BASED ON FRAC ACTINOPORIN

NARCIS (Netherlands)

Maglia, Giovanni; Wloka, Carsten; Mutter, Natalie Lisa; Soskine, Misha; Huang, Gang

2018-01-01

The invention relates generally to the field of nanopores and the use thereof in various applications, such as analysis of biopolymer s and macromolecules, typically by making electrical measurements during translocation through a nanopores. Provided is a system comprising a funnel- shaped

Electrical study on Carboxymethyl Cellulose-Polyvinyl alcohol based bio-polymer blend electrolytes

Science.gov (United States)

Saadiah, M. A.; Samsudin, A. S.

2018-04-01

The present work deals with the formulation of bio-materials namely carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVA) for bio-polymer blend electrolytes (BBEs) system which was successfully carried out with different ratio of polymer blend. The biopolymer blend was prepared via economical & classical technique that is solution casting technique and was characterized by using impedance spectroscopy (EIS). The ionic conductivity was achieved to optimum value 9.12 x 10-6 S/cm at room temperature for sample containing ratio 80:20 of CMC:PVA. The highest conducting sample was found to obey the Arrhenius behaviour with a function of temperature. The electrical properties were analyzed using complex permittivity ε* and complex electrical modulus M* for BBEs system and it shows the non-Debye characteristics where no single relaxation time has observed.

Page 170 Use of Electronic Resources by Undergraduates in Two ...

African Journals Online (AJOL)

undergraduate students use electronic resources such as NUC virtual library, HINARI, ... web pages articles from magazines, encyclopedias, pamphlets and other .... of Nigerian university libraries have Internet connectivity, some of the system.

Facile route of biopolymer mediated ferrocene (FO) nanoparticles in aqueous dispersion

Energy Technology Data Exchange (ETDEWEB)

Kaus, Noor Haida Mohd., E-mail: noorhaida@usm.my [School of Chemical Sciences, Universiti Sains Malaysia, 11800, Penang, Malaysia and Centre for Organized Matter Chemistry, School of Chemistry, Cantock' s Close, BS8 1TS, Bristol (United Kingdom); Collins, A. M.; Mann, S. [Centre for Organized Matter Chemistry, School of Chemistry, Cantock' s Close, BS8 1TS, Bristol (United Kingdom)

2014-10-24

In this paper, we present a facile method for production stable aqueous dispersion of ferrocene (FO) nanoparticles. Ferrocene compounds were employed to achieve stable nanodispersions, stabilized with three different biopolymers namely, alginate, CM-dextran and chitosan. The nanoparticles produce are spherical, less than 10 nm in mean diameter and highly stable without any sedimentation. Fourier infrared transform (FTIR) and X-ray diffraction (XRD) studies confirmed the purity of ferrocene nanoparticles there is no modifications occur during the preparation route. FTIR spectra results were consistent with the presence of absorption band of cyclopentadienyl ring (C{sub 5}H{sub 5}{sup −} ion) which assigned to ν(C-C) vibrations (1409 cm-1), δ(C-H) stretching at 1001 cm{sup −1} and π(C-H) vibrations at 812 cm{sup −1}. Furthermore, all functional group for biopolymers such as CO from carboxyl group of CM-dextran and sodium alginate appears at 1712 cm{sup −1} and 1709 cm{sup −1} respectively, indicating there are steric repulsion interactions for particles stabilization. Powder X-ray diffraction patterns of sedimented samples of the biopolymers-stabilized ferrocene (FO) showed all reflections which were indexed respectively to the (−110), (001), (−201), (−111), (200), (−211), (210), (120) and (111) according to the monoclinic phase ferrocene. This confirmed that the products obtained were of high purity of Fe and EDAX analysis also suggests that the presence of the Fe element in the colloidal dispersion.

Overview of biopolymers as carriers of antiphlogistic agents for treatment of diverse ocular inflammations

International Nuclear Information System (INIS)

Sharma, Anil Kumar; Arya, Amit; Sahoo, Pravat Kumar; Majumdar, Dipak Kanti

2016-01-01

Inflammation of the eye is a usual clinical condition that can implicate any part of the eye. The nomenclature of variety of such inflammations is based on the ocular part involved. These diseases may jeopardize normal functioning of the eye on progression. In general, corticosteroids, antihistamines, mast cell stabilizers and non-steroidal anti-inflammatory drugs (NSAIDs) are used to treat inflammatory diseases/disorders of the eye. There have been several attempts via different approaches of drug delivery to overcome the low ocular bioavailability resulting from shorter ocular residence time. The features like safety, ease of elimination and ability to sustain drug release have led to application of biopolymers in ocular therapeutics. Numerous polymers of natural origin such as gelatin, collagen, chitosan, albumin, hyaluronic acid, alginates etc. have been successfully employed for preparation of different ocular dosage forms. Chitosan is the most explored biopolymer amongst natural biopolymers because of its inherent characteristics. The emergence of synthetic biopolymers (like PVP, PACA, PCL, POE, polyanhydrides, PLA, PGA and PLGA) has also added new dimensions to the drug delivery strategies meant for treatment of ophthalmic inflammations. The current review is an endeavor to describe the utility of a variety of biomaterials/polymers based drug delivery systems as carrier for anti-inflammatory drugs in ophthalmic therapeutics. - Highlights: • Numerous eye inflammations pose troubles in vision functions. • Low bioavailability by conventional drug delivery systems due to eye constraints • Drug carriers ensuring improved bioavailability to the eye are need of the hour. • Chitosan - most explored amongst all biomaterials for ocular delivery. • Emergence of novel synthetic carriers in ophthalmology

Overview of biopolymers as carriers of antiphlogistic agents for treatment of diverse ocular inflammations

Energy Technology Data Exchange (ETDEWEB)

Sharma, Anil Kumar, E-mail: sharmarahul2004@gmail.com [Delhi Institute of Pharmaceutical Sciences and Research, Formerly College of Pharmacy, University of Delhi, Pushp Vihar, Sector III, New Delhi 110017,India (India); Arya, Amit; Sahoo, Pravat Kumar [Delhi Institute of Pharmaceutical Sciences and Research, Formerly College of Pharmacy, University of Delhi, Pushp Vihar, Sector III, New Delhi 110017,India (India); Majumdar, Dipak Kanti [School of Pharmaceutical Sciences, Apeejay Stya University, Sohna-Palwal Road, Gurgaon 122103 (India)

2016-10-01

Inflammation of the eye is a usual clinical condition that can implicate any part of the eye. The nomenclature of variety of such inflammations is based on the ocular part involved. These diseases may jeopardize normal functioning of the eye on progression. In general, corticosteroids, antihistamines, mast cell stabilizers and non-steroidal anti-inflammatory drugs (NSAIDs) are used to treat inflammatory diseases/disorders of the eye. There have been several attempts via different approaches of drug delivery to overcome the low ocular bioavailability resulting from shorter ocular residence time. The features like safety, ease of elimination and ability to sustain drug release have led to application of biopolymers in ocular therapeutics. Numerous polymers of natural origin such as gelatin, collagen, chitosan, albumin, hyaluronic acid, alginates etc. have been successfully employed for preparation of different ocular dosage forms. Chitosan is the most explored biopolymer amongst natural biopolymers because of its inherent characteristics. The emergence of synthetic biopolymers (like PVP, PACA, PCL, POE, polyanhydrides, PLA, PGA and PLGA) has also added new dimensions to the drug delivery strategies meant for treatment of ophthalmic inflammations. The current review is an endeavor to describe the utility of a variety of biomaterials/polymers based drug delivery systems as carrier for anti-inflammatory drugs in ophthalmic therapeutics. - Highlights: • Numerous eye inflammations pose troubles in vision functions. • Low bioavailability by conventional drug delivery systems due to eye constraints • Drug carriers ensuring improved bioavailability to the eye are need of the hour. • Chitosan - most explored amongst all biomaterials for ocular delivery. • Emergence of novel synthetic carriers in ophthalmology.

Model of e-learning with electronic educational resources of new generation

Directory of Open Access Journals (Sweden)

A. V. Loban

2017-01-01

Full Text Available Purpose of the article: improving of scientific and methodical base of the theory of the е-learning of variability. Methods used: conceptual and logical modeling of the е-learning of variability process with electronic educational resource of new generation and system analysis of the interconnection of the studied subject area, methods, didactics approaches and information and communication technologies means. Results: the formalization complex model of the е-learning of variability with electronic educational resource of new generation is developed, conditionally decomposed into three basic components: the formalization model of the course in the form of the thesaurusclassifier (“Author of e-resource”, the model of learning as management (“Coordination. Consultation. Control”, the learning model with the thesaurus-classifier (“Student”. Model “Author of e-resource” allows the student to achieve completeness, high degree of didactic elaboration and structuring of the studied material in triples of variants: modules of education information, practical task and control tasks; the result of the student’s (author’s of e-resource activity is the thesaurus-classifier. Model of learning as management is based on the principle of personal orientation of learning in computer environment and determines the logic of interaction between the lecturer and the student when determining the triple of variants individually for each student; organization of a dialogue between the lecturer and the student for consulting purposes; personal control of the student’s success (report generation and iterative search for the concept of the class assignment in the thesaurus-classifier before acquiring the required level of training. Model “Student” makes it possible to concretize the learning tasks in relation to the personality of the student and to the training level achieved; the assumption of the lecturer about the level of training of a

Geophysical and Geotechnical Characterization of Beta-1,3/1,6-glucan Biopolymer treated Soil

Science.gov (United States)

Chang, I.; Cho, G.

2012-12-01

Bacteria or microbes in soil excrete hydrocarbon (e.g. polysaccharide) by-products which are called biopolymers. These biopolymers (or sometime biofilms) recently begun to make a mark on soil erosion control, aggregate stabilization, and drilling enhancement. However, the biological effect on soil behavior (e.g. bio-clogging or bio-cementation) has been poorly understood. In this study, the bio-cementation and bio-clogging effect induced by the existence of β-1,3/1,6-glucan biopolymers in soil were evaluated through a series of geophysical and geotechnical characterization tests in laboratory. According to the experimental test results, as the β-1,3/1,6-glucan content in soil increases, the compressive strength and shear wave velocity increase (i.e., bio-cementation) while the hydraulic conductivity decreases (i.e., bio-clogging) but the electrical conductivity increases due to the high electrical conductivity characteristic of β-1,3/1,6-glucan fibers. Coefficient of consolidation variation with the increases of β-1,3/1,6-glucan content in soil. SEM image of β-1,3/1,6-glucan treated soil. Fibers are form matices with soil particles.

Models for stiffening in cross-linked biopolymer networks : A comparative study

NARCIS (Netherlands)

van Dillen, T.; Onck, P. R.; Van der Giessen, E.

In a recent publication, we studied the mechanical stiffening behavior in two-dimensional (2D) cross-linked networks of semiflexible biopolymer filaments under simple shear [Onck, P.R., Koeman, T., Van Dillen, T., Van der Giessen, E., 2005. Alternative explanation of stiffening in cross-linked

A survey of the use of electronic scientific information resources among medical and dental students

Directory of Open Access Journals (Sweden)

Aarnio Matti

2006-05-01

Full Text Available Abstract Background To evaluate medical and dental students' utilization of electronic information resources. Methods A web survey sent to 837 students (49.9% responded. Results Twenty-four per cent of medical students and ninteen per cent of dental students searched MEDLINE 2+ times/month for study purposes, and thiry-two per cent and twenty-four per cent respectively for research. Full-text articles were used 2+ times/month by thirty-three per cent of medical and ten per cent of dental students. Twelve per cent of respondents never utilized either MEDLINE or full-text articles. In multivariate models, the information-searching skills among students were significantly associated with use of MEDLINE and full-text articles. Conclusion Use of electronic resources differs among students. Forty percent were non-users of full-text articles. Information-searching skills are correlated with the use of electronic resources, but the level of basic PC skills plays not a major role in using these resources. The student data shows that adequate training in information-searching skills will increase the use of electronic information resources.

Access to electronic information resources by students of federal ...

African Journals Online (AJOL)

The paper discusses access to electronic information resources by students of Federal Colleges of Education in Eha-Amufu and Umunze. Descriptive survey design was used to investigate sample of 526 students. Sampling technique used was a Multi sampling technique. Data for the study were generated using ...

Adoption and use of electronic information resources by medical ...

African Journals Online (AJOL)

This study investigated the adoption and use of electronic information resources by medical science students of the University of Benin. The descriptive survey research design was adopted for the study and 390 students provided the data. Data collected were analysed with descriptive Statistics(Simple percentage and ...

Biopolymer protected silver nanoparticles on the support of carbon nanotube as interface for electrocatalytic applications

Energy Technology Data Exchange (ETDEWEB)

Satyanarayana, M.; Kumar, V. Sunil; Gobi, K. Vengatajalabathy, E-mail: drkvgobi@gmail.com, E-mail: satyam.nitw@gmail.com [Department of Chemistry, National Institute of Technology, Warangal - 506004, Telangana (India)

2016-04-13

In this research, silver nanoparticles (SNPs) are prepared on the surface of carbon nanotubes via chitosan, a biopolymer linkage. Here chitosan act as stabilizing agent for nanoparticles and forms a network on the surface of carbon nanotubes. Synthesized silver nanoparticles-MWCNT hybrid composite is characterized by UV-Visible spectroscopy, XRD analysis, and FESEM with EDS to evaluate the structural and chemical properties of the nanocomposite. The electrocatalytic activity of the fabricated SNP-MWCNT hybrid modified glassy carbon electrode has been evaluated by cyclic voltammetry and electrochemical impedance analysis. The silver nanoparticles are of size ∼35 nm and are well distributed on the surface of carbon nanotubes with chitosan linkage. The prepared nanocomposite shows efficient electrocatalytic properties with high active surface area and excellent electron transfer behaviour.

Small Strain Topological Effects of Biopolymer Networks with Rigid Cross-Links

NARCIS (Netherlands)

Zagar, G.; Onck, P. R.; Van der Giessen, E.; Garikipati, K; Arruda, EM

2010-01-01

Networks of cross-linked filamentous biopolymers form topological structures characterized by L, T and X cross-link types of connectivity 2, 3 and 4, respectively. The distribution of cross-links over these three types proofs to be very important for the initial elastic shear stiffness of isotropic

Rheological and mechanical properties of recycled polyethylene films contaminated by biopolymer.

Science.gov (United States)

Gere, D; Czigany, T

2018-06-01

Nowadays, with the increasing amount of biopolymers used, it can be expected that biodegradable polymers (e.g. PLA, PBAT) may appear in the petrol-based polymer waste stream. However, their impact on the recycling processes is not known yet; moreover, the properties of the products made from contaminated polymer blends are not easily predictable. Therefore, our goal was to investigate the rheological and mechanical properties of synthetic and biopolymer compounds. We made different compounds from regranulates of mixed polyethylene film waste and original polylactic acid (PLA) by extruison, and injection molded specimens from the compounds. We investigated the rheological properties of the regranulates, and the mechanical properties of the samples. When PLA was added, the viscosity and specific volume of all the blends decreased, and mechanical properties (tensile strength, modulus, and impact strength) changed significantly. Young's modulus increased, while elongation at break and impact strength decreased with the increase of the weight fraction of PLA. Copyright © 2018 Elsevier Ltd. All rights reserved.

Where Do Electronic Books Fit in the College Research Arsenal of Resources?

Science.gov (United States)

Barbier, Patricia

2007-01-01

Student use of electronic books has become an accepted supplement to traditional resources. Student use and satisfaction was monitored through an online course discussion board. Increased use of electronic books indicate this service is an accepted supplement to the print book collection.

Bioprocess Engineering Aspects of Biopolymer Production by the Cyanobacterium Spirulina Strain LEB 18

Directory of Open Access Journals (Sweden)

Roberta Guimarães Martins

2014-01-01

Full Text Available Microbial biopolymers can replace environmentally damaging plastics derived from petrochemicals. We investigated biopolymer synthesis by the cyanobacterium Spirulina strain LEB 18. Autotrophic culture used unmodified Zarrouk medium or modified Zarrouk medium in which the NaNO3 content was reduced to 0.25 g L−1 and the NaHCO3 content reduced to 8.4 g L−1 or increased to 25.2 g L−1. Heterotrophic culture used modified Zarrouk medium containing 0.25 g L−1 NaNO3 with the NaHCO3 replaced by 0.2 g L−1, 0.4 g L−1, or 0.6 g L−1 of glucose (C6H12O6 or sodium acetate (CH3COONa. Mixotrophic culture used modified Zarrouk medium containing 0.25 g L−1 NaNO3 plus 16.8 g L−1 NaHCO3 with the addition of 0.2 g L−1, 0.4 g L−1, or 0.6 g L−1 of glucose or sodium acetate. The highest biopolymer yield was 44% when LEB 18 was growing autotrophically in media containing 0.25 g L−1 NaNO3 and 8.4 g L−1 NaHCO3.

Single Molecule Science for Personalized Nanomedicine: Atomic Force Microscopy of Biopolymer-Protein Interactions

Science.gov (United States)

Hsueh, Carlin

Nanotechnology has a unique and relatively untapped utility in the fields of medicine and dentistry at the level of single-biopolymer and -molecule diagnostics. In recent years atomic force microscopy (AFM) has garnered much interest due to its ability to obtain atomic-resolution of molecular structures and probe biophysical behaviors of biopolymers and proteins in a variety of biologically significant environments. The work presented in this thesis focuses on the nanoscale manipulation and observation of biopolymers to develop an innovative technology for personalized medicine while understanding complex biological systems. These studies described here primarily use AFM to observe biopolymer interactions with proteins and its surroundings with unprecedented resolution, providing a better understanding of these systems and interactions at the nanoscale. Transcriptional profiling, the measure of messenger RNA (mRNA) abundance in a single cell, is a powerful technique that detects "behavior" or "symptoms" at the tissue and cellular level. We have sought to develop an alternative approach, using our expertise in AFM and single molecule nanotechnology, to achieve a cost-effective high throughput method for sensitive detection and profiling of subtle changes in transcript abundance. The technique does not require amplification of the mRNA sample because the AFM provides three-dimensional views of molecules with unprecedented resolution, requires minimal sample preparation, and utilizes a simple tagging chemistry on cDNA molecules. AFM images showed collagen polymers in teeth and of Drebrin-A remodeling of filamentous actin structure and mechanics. AFM was used to image collagen on exposed dentine tubules and confirmed tubule occlusion with a desensitizing prophylaxis paste by Colgate-Palmolive. The AFM also superseded other microscopy tools in resolving F-actin helix remodeling and possible cooperative binding by a neuronal actin binding protein---Drebrin-A, an

Strategic Planning for Electronic Resources Management: A Case Study at Gustavus Adolphus College

Science.gov (United States)

Hulseberg, Anna; Monson, Sarah

2009-01-01

Electronic resources, the tools we use to manage them, and the needs and expectations of our users are constantly evolving; at the same time, the roles, responsibilities, and workflow of the library staff who manage e-resources are also in flux. Recognizing a need to be more intentional and proactive about how we manage e-resources, the…

REVIEW OF MOODLE PLUGINS FOR DESIGNING MULTIMEDIA ELECTRONIC EDUCATIONAL RESOURCES FROM LANGUAGE DISCIPLINES

Directory of Open Access Journals (Sweden)

Anton M. Avramchuk

2015-09-01

Full Text Available Today the problem of designing multimedia electronic educational resources from language disciplines in Moodle is very important. This system has a lot of different, powerful resources, plugins to facilitate the learning of students with language disciplines. This article presents an overview and comparative analysis of the five Moodle plugins for designing multimedia electronic educational resources from language disciplines. There have been considered their key features and functionality in order to choose the best for studying language disciplines in the Moodle. Plugins are compared by a group of experts according to the criteria: efficiency, functionality and easy use. For a comparative analysis of the plugins it is used the analytic hierarchy process.

Biopolymer nanostructures induced by plasma irradiation and metal sputtering

Czech Academy of Sciences Publication Activity Database

Slepička, P.; Juřík, P.; Malinský, Petr; Macková, Anna; Kasálková-Slepičková, N.; Švorčík, V.

2014-01-01

Roč. 332, 7-10 (2014), s. 7-10 ISSN 0168-583X. [21st International Conference on Ion Beam Analysis (IBA). Seattle, 23.06.2013-28.06.2013] R&D Projects: GA ČR ga13-06609S; GA ČR(CZ) GAP108/10/1106 Institutional support: RVO:61389005 Keywords : Biopolymer * plasma * surface morphology * RBS * Ripple pattern Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.124, year: 2014

Fabrication of porous biopolymer substrates for cell growth by UV laser: The role of pulse duration

International Nuclear Information System (INIS)

Castillejo, Marta; Rebollar, Esther; Oujja, Mohamed; Sanz, Mikel; Selimis, Alexandros; Sigletou, Maria; Psycharakis, Stelios; Ranella, Anthi; Fotakis, Costas

2012-01-01

Highlights: ► UV laser-induced superficial foaming in biopolymer films with fs, ps and ns pulses. ► Reduction of photochemical and structural modifications by ultrashort fs irradiation. ► Successful cell culture on laser-induced foam structure generated in chitosan. - Abstract: Ultraviolet laser irradiation using pulses with duration from the nanosecond to the femtosecond range was investigated aiming at the generation of a foam layer on films of the biopolymers chitosan, starch and their blend. We report on the morphological characteristics of the foams obtained upon irradiation and on the accompanying laser induced photochemistry, assessed by on line monitoring of the laser induced fluorescence. We identify the laser conditions (pulse duration) at which foaming is produced and discuss the obtained results in reference to the material properties, particularly extinction coefficient and thermal parameters. This article also reports on successful cell culture on the laser induced foam structure generated in chitosan, as an illustrative example of the possibility of broader use of laser induced biopolymer foaming structures in biology.

Modern ICT Tools: Online Electronic Resources Sharing Using Web ...

African Journals Online (AJOL)

Modern ICT Tools: Online Electronic Resources Sharing Using Web 2.0 and Its Implications For Library And Information Practice In Nigeria. ... The PDF file you selected should load here if your Web browser has a PDF reader plug-in installed (for example, a recent version of Adobe Acrobat Reader). If you would like more ...

Obtention of gelatin biopolymers by ionizing radiation

International Nuclear Information System (INIS)

Takinami, Patricia Yoko Inamura

2014-01-01

The gelatin (Gel) is a biocompatible and biodegradable biopolymer, which naturally forms semi-solid colloids or hydrogels in aqueous solutions. As a hydrophilic polymer, the Gel has structural and physico-mechanical properties that distinguish it from synthetic hydrophilic polymers. The study of these properties led to the development of the present work. Thus, Gel-based films and hydrogels were developed using ionizing radiation technology by different techniques: irradiation with 60 Co, electron beam (EB) and/or pulsed EB. The Gel based-films enriched with different additives, such as glycerol (GLY), polyvinyl alcohol (PVA), butylated hydroxytoluene (BHT), acrylamide and/or vegetal fiber, were irradiated with doses from 10 to 60 kGy, depending on the additive; some parameters like mechanical properties, color, and water absorption were analyzed. In the radio-induced synthesis of GEL nanohydrogels, polyethylene glycol (PEG) and the mixture (MIX) of additives, PEG and GEL, the size, molar mass and surface morphology of the nanohydrogels were analyzed. There was a significant increase of gel fraction with increase of the radiation dose for the GEL/fiber samples. The GEL based-films with 10% PVA irradiated at 20 kGy showed the highest puncture strength. The addition of antioxidant BHT affected on some GEL based-films properties on applied conditions. Regarding the nanohydrogels, there was a decrease of hydrodynamic radius of MIX irradiated with 60 Co from 68 ± 25 nm (2 kGy) to 35 ± 4 nm (5 kGy). The radiation proved to be a convenient tool in the modification of polymeric materials for both, GEL films and hydrogels. (author)

THE MODEL OF LINGUISTIC TEACHERS’ COMPETENCY DEVELOPMENT ON DESIGNING MULTIMEDIA ELECTRONIC EDUCATIONAL RESOURCES IN THE MOODLE SYSTEM

Directory of Open Access Journals (Sweden)

Anton M. Avramchuk

2017-10-01

Full Text Available The article is devoted to the problem of developing the competency of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system. The concept of "the competence of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system" is justified and defined. Identified and characterized the components by which the levels of the competency development of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system should be assessed. Developed a model for the development of the competency of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system, which is based on the main scientific approaches, used in adult education, and consists of five blocks: target, informative, technological, diagnostic and effective.

Biopolymer strategy for the treatment of Wilson´s disease

Czech Academy of Sciences Publication Activity Database

Vetrík, Miroslav; Mattová, J.; Macková, Hana; Kučka, Jan; Poučková, P.; Kukačková, Olivia; Brus, Jiří; Eigner-Henke, S.; Sedláček, Ondřej; Šefc, L.; Štěpánek, Petr; Hrubý, Martin

2018-01-01

Roč. 273, 10 March (2018), s. 131-138 ISSN 0168-3659 R&D Projects: GA ČR(CZ) GA16-02870S; GA MZd(CZ) NV15-25781A; GA MŠk(CZ) LM2015064; GA MŠk(CZ) LO1507 Institutional support: RVO:61389013 Keywords : Wilson's disease * copper chelators * biopolymers Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 7.786, year: 2016

Developing Humanities Collections in the Digital Age: Exploring Humanities Faculty Engagement with Electronic and Print Resources

Science.gov (United States)

Kachaluba, Sarah Buck; Brady, Jessica Evans; Critten, Jessica

2014-01-01

This article is based on quantitative and qualitative research examining humanities scholars' understandings of the advantages and disadvantages of print versus electronic information resources. It explores how humanities' faculty members at Florida State University (FSU) use print and electronic resources, as well as how they perceive these…

Study of basic biopolymer as proton membrane for fuel cell systems

International Nuclear Information System (INIS)

Ramirez-Salgado, Joel

2007-01-01

Up to now, many research groups work to improve the electrical and mechanical properties of membranes with a low cost of production. The biopolymers could be an answer to produce proton membranes at low cost. This work demonstrates that the intrinsic membrane polymer and clays properties can help to develop a novel proton exchange membranes. Biopolymer composites (chitosan-oxide compounds) present conductivity between 10 -3 and 10 -2 S cm -1 . The measurements were calculated by EIS (1 MHz-0.05 Hz) using the two-electrode configuration. Different oxides were used: MgO, CaO, SiO 2 , Al 2 O 3 . The ionic conductivities were compared with Nafion (registered)'s in the same conditions of P and T. The catalyst layer/membrane ensemble was made during the design with the subsequent demonstration as membrane electrode assemblies and finally the fuel cell was built. Our focus was to increase the compatibility between the proton basic polymer exchange membrane and basic clays as CaO and test a new kind of fuel cell

Biopolymer production using fungus Mucor racemosus Fresenius and glycerol as substrate

Directory of Open Access Journals (Sweden)

Thaíssa Rodrigues Araújo

Full Text Available Abstract This study evaluated extracellular production of biopolymer using fungus Mucor racemosus Fresenius and glycerol as a carbon source. Initially employing conical flasks of 500 mL containing 100 mL of cultive medium with 0.18 ± 0.03 g.L–1 of microorganisms, the results showed that the best conditions of the variables studied were: initial concentration of glycerol 50 g.L–1, fermentation time of 96 h, inoculum cultivation time of 120 h, and aeration in two stages–the first 24 hours without aeration and 72 hours fermentation with aeration of 2 vvm and 2 g.L–1 of yeast extract. The experiments conducted in a Biostat B fermenter with a 2.0 L capacity that contained 1.0 L of medium showed production of 16.35 g.L–1 gum formed and 75% glycerol consumption. These conditions produced a biopolymer with the molecular weight and total sugar content of 4.607×106 g.mol–1 (Da and 89.5%, respectively.

Equilibrium & Nonequilibrium Fluctuation Effects in Biopolymer Networks

Science.gov (United States)

Kachan, Devin Michael

Fluctuation-induced interactions are an important organizing principle in a variety of soft matter systems. In this dissertation, I explore the role of both thermal and active fluctuations within cross-linked polymer networks. The systems I study are in large part inspired by the amazing physics found within the cytoskeleton of eukaryotic cells. I first predict and verify the existence of a thermal Casimir force between cross-linkers bound to a semi-flexible polymer. The calculation is complicated by the appearance of second order derivatives in the bending Hamiltonian for such polymers, which requires a careful evaluation of the the path integral formulation of the partition function in order to arrive at the physically correct continuum limit and properly address ultraviolet divergences. I find that cross linkers interact along a filament with an attractive logarithmic potential proportional to thermal energy. The proportionality constant depends on whether and how the cross linkers constrain the relative angle between the two filaments to which they are bound. The interaction has important implications for the synthesis of biopolymer bundles within cells. I model the cross-linkers as existing in two phases: bound to the bundle and free in solution. When the cross-linkers are bound, they behave as a one-dimensional gas of particles interacting with the Casimir force, while the free phase is a simple ideal gas. Demanding equilibrium between the two phases, I find a discontinuous transition between a sparsely and a densely bound bundle. This discontinuous condensation transition induced by the long-ranged nature of the Casimir interaction allows for a similarly abrupt structural transition in semiflexible filament networks between a low cross linker density isotropic phase and a higher cross link density bundle network. This work is supported by the results of finite element Brownian dynamics simulations of semiflexible filaments and transient cross-linkers. I

Single walled carbon nanotubes functionally adsorbed to biopolymers for use as chemical sensors

Science.gov (United States)

Johnson, Jr., Alan T.; Gelperin, Alan [Princeton, NJ; Staii, Cristian [Madison, WI

2011-07-12

Chemical field effect sensors comprising nanotube field effect devices having biopolymers such as single stranded DNA functionally adsorbed to the nanotubes are provided. Also included are arrays comprising the sensors and methods of using the devices to detect volatile compounds.

Electronic resource management systems a workflow approach

CERN Document Server

Anderson, Elsa K

2014-01-01

To get to the bottom of a successful approach to Electronic Resource Management (ERM), Anderson interviewed staff at 11 institutions about their ERM implementations. Among her conclusions, presented in this issue of Library Technology Reports, is that grasping the intricacies of your workflow-analyzing each step to reveal the gaps and problems-at the beginning is crucial to selecting and implementing an ERM. Whether the system will be used to fill a gap, aggregate critical data, or replace a tedious manual process, the best solution for your library depends on factors such as your current soft

Electronic Resource Management System. Vernetzung von Lizenzinformationen

Directory of Open Access Journals (Sweden)

Michaela Selbach

2014-12-01

Full Text Available In den letzten zehn Jahren spielen elektronische Ressourcen im Bereich der Erwerbung eine zunehmend wichtige Rolle: Eindeutig lässt sich hier ein Wandel in den Bibliotheken (fort vom reinen Printbestand zu immer größeren E-Only-Beständen feststellen. Die stetig wachsende Menge an E-Ressourcen und deren Heterogenität stellt Bibliotheken vor die Herausforderung, die E-Ressourcen effizient zu verwalten. Nicht nur Bibliotheken, sondern auch verhandlungsführende Institutionen von Konsortial- und Allianzlizenzen benötigen ein geeignetes Instrument zur Verwaltung von Lizenzinformationen, welches den komplexen Anforderungen moderner E-Ressourcen gerecht wird. Die Deutsche Forschungsgemeinschaft (DFG unterstützt ein Projekt des Hochschulbibliothekszentrums des Landes Nordrhein-Westfalen (hbz, der Universitätsbibliothek Freiburg, der Verbundzentrale des Gemeinsamen Bibliotheksverbundes (GBV und der Universitätsbibliothek Frankfurt, in dem ein bundesweit verfügbares Electronic Ressource Managementsystem (ERMS aufgebaut werden soll. Ein solches ERMS soll auf Basis einer zentralen Knowledge Base eine einheitliche Nutzung von Daten zur Lizenzverwaltung elektronischer Ressourcen auf lokaler, regionaler und nationaler Ebene ermöglichen. Statistische Auswertungen, Rechteverwaltung für alle angeschlossenen Bibliotheken, kooperative Datenpflege sowie ein über standardisierte Schnittstellen geführter Datenaustausch stehen bei der Erarbeitung der Anforderungen ebenso im Fokus wie die Entwicklung eines Daten- und Funktionsmodells. In the last few years the importance of electronic resources in library acquisitions has increased significantly. There has been a shift from mere print holdings to both e- and print combinations and even e-only subscriptions. This shift poses a double challenge for libraries: On the one hand they have to provide their e-resource collections to library users in an appealing way, on the other hand they have to manage these

A novel method of providing a library of n-mers or biopolymers

DEFF Research Database (Denmark)

2012-01-01

The present invention relates to a method of providing a library of n-mer sequences, wherein the library is composed of an n-mer sequence. Also the invention concerns a method of providing a library of biopolymer sequences having one or more n-mers in common. Further provided are specific primers...

Single walled carbon nanotubes with functionally adsorbed biopolymers for use as chemical sensors

Science.gov (United States)

Johnson, Jr., Alan T

2013-12-17

Chemical field effect sensors comprising nanotube field effect devices having biopolymers such as single stranded DNA or RNA functionally adsorbed to the nanotubes are provided. Also included are arrays comprising the sensors and methods of using the devices to detect volatile compounds.

Load sharing in the growth of bundled biopolymers.

Science.gov (United States)

Wang, Ruizhe; Carlsson, A E

2014-11-01

To elucidate the nature of load sharing in the growth of multiple biopolymers, we perform stochastic simulations of the growth of biopolymer bundles against obstacles under a broad range of conditions and varying assumptions. The obstacle motion due to thermal fluctuations is treated explicitly. We assume the "Perfect Brownian Ratchet" (PBR) model, in which the polymerization rate equals the free-filament rate as soon as the filament-obstacle distance exceeds the monomer size. Accurate closed-form formulas are obtained for the case of a rapidly moving obstacle. We find the following: (1) load sharing is usually sub-perfect in the sense that polymerization is slower than for a single filament carrying the same average force; (2) the sub-perfect behavior becomes significant at a total force proportional to the logarithm or the square root of the number of filaments, depending on the alignment of the filaments; (3) for the special case of slow barrier diffusion and low opposing force, an enhanced obstacle velocity for an increasing number of filaments is possible; (4) the obstacle velocity is very sensitive to the alignment of the filaments in the bundle, with a staggered alignment being an order of magnitude faster than an unstaggered one at forces of only 0.5 pN per filament for 20 filaments; (5) for large numbers of filaments, the power is maximized at a force well below 1 pN per filament; (6) for intermediate values of the obstacle diffusion coefficient, the shape of the force velocity relation is very similar to that for rapid obstacle diffusion.

The Electron Microscopy Outreach Program: A Web-based resource for research and education.

Science.gov (United States)

Sosinsky, G E; Baker, T S; Hand, G; Ellisman, M H

1999-01-01

We have developed a centralized World Wide Web (WWW)-based environment that serves as a resource of software tools and expertise for biological electron microscopy. A major focus is molecular electron microscopy, but the site also includes information and links on structural biology at all levels of resolution. This site serves to help integrate or link structural biology techniques in accordance with user needs. The WWW site, called the Electron Microscopy (EM) Outreach Program (URL: http://emoutreach.sdsc.edu), provides scientists with computational and educational tools for their research and edification. In particular, we have set up a centralized resource containing course notes, references, and links to image analysis and three-dimensional reconstruction software for investigators wanting to learn about EM techniques either within or outside of their fields of expertise. Copyright 1999 Academic Press.

Technical Communicator: A New Model for the Electronic Resources Librarian?

Science.gov (United States)

Hulseberg, Anna

2016-01-01

This article explores whether technical communicator is a useful model for electronic resources (ER) librarians. The fields of ER librarianship and technical communication (TC) originated and continue to develop in relation to evolving technologies. A review of the literature reveals four common themes for ER librarianship and TC. While the…

Adsorption of aluminum and lead from wastewater by chitosan-tannic acid modified biopolymers: Isotherms, kinetics, thermodynamics and process mechanism.

Science.gov (United States)

Badawi, M A; Negm, N A; Abou Kana, M T H; Hefni, H H; Abdel Moneem, M M

2017-06-01

Chitosan was reacted by tannic acid to obtain three modified chitosan biopolymer. Their chemical structures were characterized by FTIR and elemental analysis. The prepared biopolymers were used to adsorb Al(III) and Pb(II) metal ions from industrial wastewater. The factors affecting the adsorption process were biosorbent amount, initial concentration of metal ion and pH of the medium. The adsorption efficiency increased considerably with the increase of the biosorbent amount and pH of the medium. The adsorption process of biosorbent on different metal ions was fitted by Freundlich adsorption model. The adsorption kinetics was followed Pseudo-second-order kinetic model. The adsorption process occurred according to diffusion mechanism which was confirmed by the interparticle diffusion model. The modified biopolymers were efficient biosorbents for removal of Pb(II) and Al(III) metal ions from the medium. Copyright © 2017 Elsevier B.V. All rights reserved.

Development of Seaweed-based Biopolymers for Edible Films and Lectins

Science.gov (United States)

Praseptiangga, D.

2017-04-01

Marine macroalgae (seaweeds) as one of important groups of biopolymers play an important role in human life. Biopolymers have been studied regarding their film-forming properties to produce edible films intended as food packaging and active ingredient carriers. Edible film, a thin layer or which is an integral part of food and can be eaten together with, have been used to avoid food quality deterioration due to physico-chemical changes, texture changes, or chemical reactions. Film-forming materials can be utilized individually or as mixed composite blends. Proteins and polysaccharides used for their mechanical and structural properties, and hydrophobic substances (lipids, essential oils, and emulsifiers) to provide good moisture barrier properties. In addition, bioactive substances from marine natural products, including seaweeds, have been explored for being used in the fields of medicine, food science, pharmaceutical science, biochemistry, and glycobiology. Among them, lectins or carbohydrate-binding proteins from seaweeds have recently been remarked. Lectins (hemagglutinins) are widely distributed in nature and also good candidates in such prospecting of seaweeds. They are useful as convenient tools to discriminate differences in carbohydrate structures and reveal various biological activities through binding and interacting to carbohydrates, suggesting that they are promising candidates for medicinal and clinical application.

Engineering bacterial biopolymers for the biosorption of heavy metals; new products and novel formulations

International Nuclear Information System (INIS)

Gutnick, D.L.; Bach, H.

2000-01-01

Bioremediation of heavy metal pollution remains a major challenge in environmental biotechnology. One of the approaches considered for application involves biosorption either to biomass or to isolated biopolymers. Many bacterial polysaccharides have been shown to bind heavy metals with varying degrees of specificity and affinity. While various approaches have been adopted to generate polysaccharide variants altered in both structure and activity, metal biosorption has not been examined. Polymer engineering has included structural modification through the introduction of heterologous genes of the biosynthetic pathway into specific mutants, leading either to alterations in polysaccharide backbone or side chains, or to sugar modification. In addition, novel formulations can be designed which enlarge the family of available bacterial biopolymers for metal-binding and subsequent recovery. An example discussed here is the use of amphipathic bioemulsifiers such as emulsan, produced by the oil-degrading Acinetobacter lwoffii RAG-1, that forms stable, concentrated (70%), oil-in-water emulsions (emulsanosols). In this system metal ions bind primarily at the oil/water interface, enabling their recovery and concentration from relatively dilute solutions. In addition to the genetic modifications described above, a new approach to the generation of amphipathic bioemulsifying formulations is based on the interaction of native or recombinant esterase and its derivatives with emulsan and other water-soluble biopolymers. Cation-binding emulsions are generated from a variety of hydrophobic substrates. The features of these and other systems will be discussed, together with a brief consideratiton of possible applications. (orig.)

In-situ modification, regeneration, and application of keratin biopolymer for arsenic removal

Energy Technology Data Exchange (ETDEWEB)

Khosa, Muhammad A.; Ullah, Aman, E-mail: amanullah@ualberta.ca

2014-08-15

Graphical abstract: - Highlights: • In-situ chemical modification of keratin based material was carried out. • Characterization techniques such as SEM, FTIR, XRD, and DSC were employed. • TGA data was elaborated for its complete thermal and kinetic study. • Sorption of As(III) using modified material was experimentally studied. • Thermodynamics and Isotherm study was made for elucidation of adsorption data. - Abstract: Chemical modification of chicken feathers (CF) and their subsequent role in arsenic removal from water is presented in this paper. The ground CF were chemically treated with four selective dopants such as poly (ethylene glycol) (PEG) diglycidyl ether, poly (N-isopropylacrylamide) (PNIPAM), allyl alcohol (AA) and TrisilanolCyclohexyl POSS. After modification, the solubilized keratin was regenerated by precipitation at acidic pH. The structural changes and properties of modified biopolymer were compared with untreated CF and confirmed by different characterization techniques such as SEM, FTIR, XRD, and DSC. The TGA data was used to discuss thermal decomposition and kinetic behavior of modified biopolymer exhaustively. The modified biopolymers were further investigated as biosorbents for their application in As(III) removal from water. The AA and POSS supported biosorbents executed high removal capacity for As(III) up to 11.5 × 10{sup −2}and 11.0 × 10{sup −2} mg/g from 100 ml arsenic polluted water solution respectively. Thermodynamic parameters such as ΔG{sup 0}, ΔH{sup 0}, ΔS{sup 0} were also evaluated with the finding that overall sorption process was endothermic and spontaneous in nature. Based on linear and non-linear regression analysis, Freundlich Isotherm model showed good fit for obtained sorption data apart from high linear regression values supporting Langmuir isotherm model in sorption of As(III)

Tailored topography control of biopolymer surfaces by ultrafast lasers for cell–substrate studies

International Nuclear Information System (INIS)

Rusen, L.; Cazan, M.; Mustaciosu, C.; Filipescu, M.; Sandel, S.; Zamfirescu, M.; Dinca, V.; Dinescu, M.

2014-01-01

Nowadays, the culture surfaces used for in vitro testing must be capable of possessing an improved interface for cell interactions and adhesion. For this reason, the materials used need to have an appropriate chemistry and architecture of its surface, resembling to the extracellular matrix. Within this context, in this work we combined the advantages of natural biopolymer characteristics (chitosan) with the flexibility in surface texturing by ultrafast laser for creating functional microstructured surfaces for cell–substrate in vitro studies. A Ti:Sapphire femtosecond laser irradiation (λ = 775 nm and 387 nm) was used for tailoring surface morphological characteristics of chitosan based films (i.e. polymer “bubbles”, “fingertips” and “sponge-like” structures). These structures were investigated by scanning electron microscopy and atomic force microscopy. The morphology of the structures obtained was correlated with the response of oligodendrocytes cells line. In vitro tests on the patterned surface showed that early cell growth was conditioned by the microtopography and indicate possible uses of the structures in biomedical applications.

MODEL OF AN ELECTRONIC EDUCATIONAL RESOURCE OF NEW GENERATION

Directory of Open Access Journals (Sweden)

Anatoliy V. Loban

2016-01-01

Full Text Available The mathematical structure of the modular architecture of an electronic educational resource (EER of new generation, which allows to decompose the process of studying the subjects of the course at a hierarchically ordered set of data (knowledge and procedures for manipulating them, to determine the roles of participants of process of training of and technology the development and use of EOR in the study procrate.

In situ enzyme aided adsorption of soluble xylan biopolymers onto cellulosic material.

Science.gov (United States)

Chimphango, Annie F A; Görgens, J F; van Zyl, W H

2016-06-05

The functional properties of cellulose fibers can be modified by adsorption of xylan biopolymers. The adsorption is improved when the degree of biopolymers substitution with arabinose and 4-O-methyl-glucuronic acid (MeGlcA) side groups, is reduced. α-l-Arabinofuranosidase (AbfB) and α-d-glucuronidase (AguA) enzymes were applied for side group removal, to increase adsorption of xylan from sugarcane (Saccharum officinarum L) bagasse (BH), bamboo (Bambusa balcooa) (BM), Pinus patula (PP) and Eucalyptus grandis (EH) onto cotton lint. The AguA treatment increased the adsorption of all xylans by up to 334%, whereas, the AbfB increased the adsorption of the BM and PP by 31% and 44%, respectively. A combination of AguA and AbfB treatment increased the adsorption, but to a lesser extent than achieved with AguA treatment. This indicated that the removal of the glucuronic acid side groups provided the most significant increase in xylan adsorption to cellulose, in particular through enzymatic treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Bacillus and biopolymer: Prospects and challenges

Directory of Open Access Journals (Sweden)

Swati Mohapatra

2017-12-01

Full Text Available The microbially derived polyhydroxyalkanoates biopolymers could impact the global climate scenario by replacing the conventional non-degradable, petrochemical-based polymer. The biogenesis, characterization and properties of PHAs by Bacillus species using renewable substrates have been elaborated by many for their wide applications. On the other hand Bacillus species are advantageous over other bacteria due to their abundance even in extreme ecological conditions, higher growth rates even on cheap substrates, higher PHAs production ability, and the ease of extracting the PHAs. Bacillus species possess hydrolytic enzymes that can be exploited for economical PHAs production. This review summarizes the recent trends in both non-growth and growth associated PHAs production by Bacillus species which may provide direction leading to future research towards this growing quest for biodegradable plastics, one more critical step ahead towards sustainable development.

Beyond Textbook Illustrations: Hand-Held Models of Ordered DNA and Protein Structures as 3D Supplements to Enhance Student Learning of Helical Biopolymers

Science.gov (United States)

Jittivadhna, Karnyupha; Ruenwongsa, Pintip; Panijpan, Bhinyo

2010-01-01

Textbook illustrations of 3D biopolymers on printed paper, regardless of how detailed and colorful, suffer from its two-dimensionality. For beginners, computer screen display of skeletal models of biopolymers and their animation usually does not provide the at-a-glance 3D perception and details, which can be done by good hand-held models. Here, we…

Associative Interactions in Crowded Solutions of Biopolymers Counteract Depletion Effects.

Science.gov (United States)

Groen, Joost; Foschepoth, David; te Brinke, Esra; Boersma, Arnold J; Imamura, Hiromi; Rivas, Germán; Heus, Hans A; Huck, Wilhelm T S

2015-10-14

The cytosol of Escherichia coli is an extremely crowded environment, containing high concentrations of biopolymers which occupy 20-30% of the available volume. Such conditions are expected to yield depletion forces, which strongly promote macromolecular complexation. However, crowded macromolecule solutions, like the cytosol, are very prone to nonspecific associative interactions that can potentially counteract depletion. It remains unclear how the cytosol balances these opposing interactions. We used a FRET-based probe to systematically study depletion in vitro in different crowded environments, including a cytosolic mimic, E. coli lysate. We also studied bundle formation of FtsZ protofilaments under identical crowded conditions as a probe for depletion interactions at much larger overlap volumes of the probe molecule. The FRET probe showed a more compact conformation in synthetic crowding agents, suggesting strong depletion interactions. However, depletion was completely negated in cell lysate and other protein crowding agents, where the FRET probe even occupied slightly more volume. In contrast, bundle formation of FtsZ protofilaments proceeded as readily in E. coli lysate and other protein solutions as in synthetic crowding agents. Our experimental results and model suggest that, in crowded biopolymer solutions, associative interactions counterbalance depletion forces for small macromolecules. Furthermore, the net effects of macromolecular crowding will be dependent on both the size of the macromolecule and its associative interactions with the crowded background.

The correlation between gelatin macroscale differences and nanoparticle properties: providing insight into biopolymer variability.

Science.gov (United States)

Stevenson, André T; Jankus, Danny J; Tarshis, Max A; Whittington, Abby R

2018-05-21

From therapeutic delivery to sustainable packaging, manipulation of biopolymers into nanostructures imparts biocompatibility to numerous materials with minimal environmental pollution during processing. While biopolymers are appealing natural based materials, the lack of nanoparticle (NP) physicochemical consistency has decreased their nanoscale translation into actual products. Insights regarding the macroscale and nanoscale property variation of gelatin, one of the most common biopolymers already utilized in its bulk form, are presented. Novel correlations between macroscale and nanoscale properties were made by characterizing similar gelatin rigidities obtained from different manufacturers. Samples with significant differences in clarity, indicating sample purity, obtained the largest deviations in NP diameter. Furthermore, a statistically significant positive correlation between macroscale molecular weight dispersity and NP diameter was determined. New theoretical calculations proposing the limited number of gelatin chains that can aggregate and subsequently get crosslinked for NP formation were presented as one possible reason to substantiate the correlation analysis. NP charge and crosslinking extent were also related to diameter. Lower gelatin sample molecular weight dispersities produced statistically smaller average diameters (<75 nm), and higher average electrostatic charges (∼30 mV) and crosslinking extents (∼95%), which were independent of gelatin rigidity, conclusions not shown in the literature. This study demonstrates that the molecular weight composition of the starting material is one significant factor affecting gelatin nanoscale properties and must be characterized prior to NP preparation. Identifying gelatin macroscale and nanoscale correlations offers a route toward greater physicochemical property control and reproducibility of new NP formulations for translation to industry.

Flexible design of band gaps in the biopolymer photonic crystals

International Nuclear Information System (INIS)

Savić-Šević, S

2012-01-01

One-dimensional photonic crystals (PC) are fabricated in dichromate-sensitized biopolymer as volume holograms. The flexibility of the PC band gap (BG) parameters was investigated. The spectral position of a BG can be varied by changing the exposure for two concentrations of sensitizer during the fabrication process. The spectral measurements show that the BG centre shifts towards longer wavelengths with decreasing exposure and concentration of the sensitizer. A tuning of the position of the BG for about 120 nm was obtained.

Biopolymer films to control fusarium dry rot and their application to preserve potato tubers

Science.gov (United States)

Films were cast using sodium alginate (NaAlg), high molecular weight (HMW) chitosan, and low molecular weight (LMW) chitosan as film forming biopolymers. Fludioxonil (Fl) at 1% concentration was used as fungicide. Thermal stability, mechanical, and water sorption properties of the films were examine...

GUIDELINES FOR EVALUATION OF PSYCHOLOGICAL AND PEDAGOGICAL QUALITY CHARACTERISTICS OF ELECTRONIC EDUCATIONAL RESOURCES

Directory of Open Access Journals (Sweden)

Galina P. Lavrentieva

2014-05-01

Full Text Available The article highlights the causes of insufficient effective use of electronic learning resources and sets out the guidelines on ways to solve the aforementioned problems. The set of didactic, methodical, psychological, pedagogical, design and ergonomic quality requirements is considered for evaluation, selection and application of information and communication technologies in the educational process. The most appropriate mechanisms for the ICT introduction into the learning process are disclosed as it should meet the specific learning needs of the student and the objectives of the educational process. The guidance for psycho-educational assessment of quality of electronic educational resources is provided. It is argued that the effectiveness of the ICT use is to be improved by means of quality evaluation mechanisms involved into the educational process.

Properties and characterization of bionanocomposite films prepared with various biopolymers and ZnO nanoparticles.

Science.gov (United States)

Kanmani, Paulraj; Rhim, Jong-Whan

2014-06-15

This study was aimed to develop biopolymer based antimicrobial films for active food packaging and to reduce environmental pollution caused by accumulation of synthetic packaging. The ZnO NPs were incorporated as antimicrobials into different biopolymers such as agar, carrageenan and CMC. Solvent casting method was performed to prepare active nanocomposite films. Methods such as FE-SEM, FT-IR and XRD were used to characterize resulting films. Physical, mechanical, thermal and antimicrobial properties were also examined. Remarkable surface morphological differences were observed between control and nanocomposite films. The crystallinity of ZnO was confirmed by XRD analysis. The addition of ZnO NPs increased color, UV barrier, moisture content, hydrophobicity, elongation and thermal stability of the films, while decreased WVP, tensile strength and elastic modulus. ZnO NPs impregnated films inhibited growth of L. monocytogenes and E. coli. So these newly prepared nanocomposite films can be used as active packaging film to extend shelf-life of food. Copyright © 2014 Elsevier Ltd. All rights reserved.

Polymethacrylate-based monoliths as stationary phases for separation of biopolymers and immobilization of enzymes.

Science.gov (United States)

Martinović, Tamara; Josić, Djuro

2017-11-01

The experiences in the production and application of polymethacrylate-based monolithic supports, since their development almost thirty years ago, are presented. The main driving force for the development of new chromatographic supports was the necessity for the isolation and separation of physiologically active biopolymers and their use for therapeutic purposes. For this sake, a development of a method for fast separation, preventing denaturation and preserving their biological activity was necessary. Development of polysaccharide-based supports, followed by the introduction of polymer-based chromatographic media, is shortly described. This development was followed by the advances in monolithic media that are now used for both large- and small-scale separation of biopolymers and nanoparticles. Finally, a short overview is given about the applications of monoliths for sample displacement chromatography, resulting in isolation of physiologically active biomolecules, such as proteins, protein complexes, and nucleic acid, as well as high-throughput sample preparation for proteomic investigations. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Availability, Use and Constraints to Use of Electronic Information Resources by Postgraduates Students at the University of Ibadan

Directory of Open Access Journals (Sweden)

Dare Samuel Adeleke

2017-12-01

Full Text Available Availability, awareness and use of electronic resources provide access to authoritative, reliable, accurate and timely access to information. The use of electronic information resources (EIRs can enable innovation in teaching and increase timeliness in research of postgraduate students which will eventual result into encouragement of the expected research-led enquiry in this digital age. The study adopted a descriptive survey design. Samples of 300 of postgraduate students within seven out 13 Faculties were randomly selected. Data were collected using questionnaire designed to elicit response from respondents and data were analyzed using descriptive statistics methods percentages, mean, and standard deviation. Results indicated that internet was ranked most available and used in the university. Low level of usage of electronic resources, in particular, full texts data bases is linked to a number of constraints: Interrupted power supply was ranked highest among other factors as speed and capacity of computers, retrieval of records with high recall and low precision, retrieving records relevant to information need, lack of knowledge of search techniques to retrieve information effectively, non possession of requisite IT skills and problems accessing the internet. The study recommended that usage of electronic resources be made compulsory, intensifying awareness campaigns concerning the availability, training on use of electronic resources and the problem of power outage be addressed.

A Study on Developing Evaluation Criteria for Electronic Resources in Evaluation Indicators of Libraries

Science.gov (United States)

Noh, Younghee

2010-01-01

This study aimed to improve the current state of electronic resource evaluation in libraries. While the use of Web DB, e-book, e-journal, and other e-resources such as CD-ROM, DVD, and micro materials is increasing in libraries, their use is not comprehensively factored into the general evaluation of libraries and may diminish the reliability of…

Oxidation of alginate and pectate biopolymers by cerium(IV) in perchloric and sulfuric acid solutions: A comparative kinetic and mechanistic study.

Science.gov (United States)

Fawzy, Ahmed

2016-03-15

The kinetics of oxidation of alginate (Alg) and pectate (Pec) carbohydrate biopolymers was studied by spectrophotometry in aqueous perchloric and sulfuric acid solutions at fixed ionic strengths and temperature. In both acids, the reactions showed a first order dependence on [Ce(IV)], whereas the orders with respect to biopolymer concentrations are less than unity. In perchloric acid, the reactions exhibited less than unit orders with respect to [H(+)] whereas those proceeded in sulfuric acid showed negative fractional-first order dependences on [H(+)]. The effect of ionic strength and dielectric constant was studied. Probable mechanistic schemes for oxidation reactions were proposed. In both acids, the final oxidation products were characterized as mono-keto derivatives of both biopolymers. The activation parameters with respect to the slow step of the mechanisms were computed and discussed. The rate laws were derived and the reaction constants involved in the different steps of the mechanisms were calculated. Copyright © 2015 Elsevier Ltd. All rights reserved.

A differential vapor-pressure equipment for investigations of biopolymer interactions

DEFF Research Database (Denmark)

Andersen, Kim B; Koga, Y.; Westh, Peter

2002-01-01

the use of high-accuracy capacitance manometers and a leak-tight system of stainless steel pipes, below-scaled valves and metal-gasket fittings, DeltaP can be measured with a resolution of about 0.5 mubar (0.05 Pa) in some applications. This sensitivity level, along with other features of the equipment......, particularly a "gas-phase titration" routine for changing the cell composition, makes it effective for the investigations of several types of biopolymer interactions. These include isothermal studies of net affinities such as the adsorption of water to proteins or membranes, the preferential interaction...

THE MODEL OF LINGUISTIC TEACHERS’ COMPETENCY DEVELOPMENT ON DESIGNING MULTIMEDIA ELECTRONIC EDUCATIONAL RESOURCES IN THE MOODLE SYSTEM

OpenAIRE

Anton M. Avramchuk

2017-01-01

The article is devoted to the problem of developing the competency of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system. The concept of "the competence of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system" is justified and defined. Identified and characterized the components by which the levels of the competency development of teachers of language disciplines on designing ...

Integrated systems for biopolymers and bioenergy production from organic waste and by-products: a review of microbial processes.

Science.gov (United States)

Pagliano, Giorgia; Ventorino, Valeria; Panico, Antonio; Pepe, Olimpia

2017-01-01

Recently, issues concerning the sustainable and harmless disposal of organic solid waste have generated interest in microbial biotechnologies aimed at converting waste materials into bioenergy and biomaterials, thus contributing to a reduction in economic dependence on fossil fuels. To valorize biomass, waste materials derived from agriculture, food processing factories, and municipal organic waste can be used to produce biopolymers, such as biohydrogen and biogas, through different microbial processes. In fact, different bacterial strains can synthesize biopolymers to convert waste materials into valuable intracellular (e.g., polyhydroxyalkanoates) and extracellular (e.g., exopolysaccharides) bioproducts, which are useful for biochemical production. In particular, large numbers of bacteria, including Alcaligenes eutrophus , Alcaligenes latus , Azotobacter vinelandii , Azotobacter chroococcum , Azotobacter beijerincki , methylotrophs, Pseudomonas spp., Bacillus spp., Rhizobium spp., Nocardia spp., and recombinant Escherichia coli , have been successfully used to produce polyhydroxyalkanoates on an industrial scale from different types of organic by-products. Therefore, the development of high-performance microbial strains and the use of by-products and waste as substrates could reasonably make the production costs of biodegradable polymers comparable to those required by petrochemical-derived plastics and promote their use. Many studies have reported use of the same organic substrates as alternative energy sources to produce biogas and biohydrogen through anaerobic digestion as well as dark and photofermentation processes under anaerobic conditions. Therefore, concurrently obtaining bioenergy and biopolymers at a reasonable cost through an integrated system is becoming feasible using by-products and waste as organic carbon sources. An overview of the suitable substrates and microbial strains used in low-cost polyhydroxyalkanoates for biohydrogen and biogas

Determining the level of awareness of the physicians in using the variety of electronic information resources and the effecting factors.

Science.gov (United States)

Papi, Ahmad; Ghazavi, Roghayeh; Moradi, Salimeh

2015-01-01

Understanding of the medical society's from the types of information resources for quick and easy access to information is an imperative task in medical researches and management of the treatment. The present study was aimed to determine the level of awareness of the physicians in using various electronic information resources and the factors affecting it. This study was a descriptive survey. The data collection tool was a researcher-made questionnaire. The study population included all the physicians and specialty physicians of the teaching hospitals affiliated to Isfahan University of Medical Sciences and numbered 350. The sample size based on Morgan's formula was set at 180. The content validity of the tool was confirmed by the library and information professionals and the reliability was 95%. Descriptive statistics were used including the SPSS software version 19. On reviewing the need of the physicians to obtain the information on several occasions, the need for information in conducting the researches was reported by the maximum number of physicians (91.9%) and the usage of information resources, especially the electronic resources, formed 65.4% as the highest rate with regard to meeting the information needs of the physicians. Among the electronic information databases, the maximum awareness was related to Medline with 86.5%. Among the various electronic information resources, the highest awareness (43.3%) was related to the E-journals. The highest usage (36%) was also from the same source. The studied physicians considered the most effective deterrent in the use of electronic information resources as being too busy and lack of time. Despite the importance of electronic information resources for the physician's community, there was no comprehensive knowledge of these resources. This can lead to less usage of these resources. Therefore, careful planning is necessary in the hospital libraries in order to introduce the facilities and full capabilities of the

Managing Selection for Electronic Resources: Kent State University Develops a New System to Automate Selection

Science.gov (United States)

Downey, Kay

2012-01-01

Kent State University has developed a centralized system that manages the communication and work related to the review and selection of commercially available electronic resources. It is an automated system that tracks the review process, provides selectors with price and trial information, and compiles reviewers' feedback about the resource. It…

Ionic Liquid Microemullsions, Templates for Directing Morphology of Cellulose Biopolymer Nanoparticles (Briefing Charts)

Science.gov (United States)

2015-08-19

Charts 3. DATES COVERED (From - To) July 2015-August 2015 4. TITLE AND SUBTITLE Ionic Liquid Microemullsions, Templates for Directing Morphology of...unlimited AFRL Public Affairs Clearance No. TBD Ionic Liquid Microemullsions, Templates for Directing Morphology of Cellulose Biopolymer...AFRL Public Affairs Clearance No. 15438 Outline • Background on Cellulose and Ionic Liquids • Materials and Methods • Results: Designing an IL

A novel method for biopolymer surface nanostructuring by platinum deposition and subsequent thermal annealing

Czech Academy of Sciences Publication Activity Database

Slepička, P.; Juřík, P.; Kolská, Z.; Malinský, Petr; Macková, Anna; Michaljaničová, I.; Švorčík, V.

2012-01-01

Roč. 7, č. 671 (2012), s. 1-6 ISSN 1931-7573 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:61389005 Keywords : nanopattering * surface morphology * biopolymer * platinum sputtering * thermal annealing Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 2.524, year: 2012

End-of-life resource recovery from emerging electronic products

DEFF Research Database (Denmark)

Parajuly, Keshav; Habib, Komal; Cimpan, Ciprian

2016-01-01

Integrating product design with appropriate end-of-life (EoL) processing is widely recognized to have huge potentials in improving resource recovery from electronic products. In this study, we investigate both the product characteristics and EoL processing of robotic vacuum cleaner (RVC), as a case...... of emerging electronic product, in order to understand the recovery fate of different materials and its linkage to product design. Ten different brands of RVC were dismantled and their material composition and design profiles were studied. Another 125 RVCs (349 kg) were used for an experimental trial...... at a conventional ‘shred-and-separate’ type preprocessing plant in Denmark. A detailed material flow analysis was performed throughout the recycling chain. The results show a mismatch between product design and EoL processing, and the lack of practical implementation of ‘Design for EoL’ thinking. In the best...

Synchrotron-Based Microspectroscopic Analysis of Molecular and Biopolymer Structures Using Multivariate Techniques and Advanced Multi-Components Modeling

International Nuclear Information System (INIS)

Yu, P.

2008-01-01

More recently, advanced synchrotron radiation-based bioanalytical technique (SRFTIRM) has been applied as a novel non-invasive analysis tool to study molecular, functional group and biopolymer chemistry, nutrient make-up and structural conformation in biomaterials. This novel synchrotron technique, taking advantage of bright synchrotron light (which is million times brighter than sunlight), is capable of exploring the biomaterials at molecular and cellular levels. However, with the synchrotron RFTIRM technique, a large number of molecular spectral data are usually collected. The objective of this article was to illustrate how to use two multivariate statistical techniques: (1) agglomerative hierarchical cluster analysis (AHCA) and (2) principal component analysis (PCA) and two advanced multicomponent modeling methods: (1) Gaussian and (2) Lorentzian multi-component peak modeling for molecular spectrum analysis of bio-tissues. The studies indicated that the two multivariate analyses (AHCA, PCA) are able to create molecular spectral corrections by including not just one intensity or frequency point of a molecular spectrum, but by utilizing the entire spectral information. Gaussian and Lorentzian modeling techniques are able to quantify spectral omponent peaks of molecular structure, functional group and biopolymer. By application of these four statistical methods of the multivariate techniques and Gaussian and Lorentzian modeling, inherent molecular structures, functional group and biopolymer onformation between and among biological samples can be quantified, discriminated and classified with great efficiency.

The Effects of Biopolymer Encapsulation on Total Lipids and Cholesterol in Egg Yolk during in Vitro Human Digestion

Directory of Open Access Journals (Sweden)

Si-Kyung Lee

2013-08-01

Full Text Available The purpose of this study was to examine the effect of biopolymer encapsulation on the digestion of total lipids and cholesterol in egg yolk using an in vitro human digestion model. Egg yolks were encapsulated with 1% cellulose, pectin, or chitosan. The samples were then passed through an in vitro human digestion model that simulated the composition of mouth saliva, stomach acid, and the intestinal juice of the small intestine by using a dialysis tubing system. The change in digestion of total lipids was monitored by confocal fluorescence microscopy. The digestion rate of total lipids and cholesterol in all egg yolk samples dramatically increased after in vitro human digestion. The digestion rate of total lipids and cholesterol in egg yolks encapsulated with chitosan or pectin was reduced compared to the digestion rate of total lipids and cholesterol in other egg yolk samples. Egg yolks encapsulated with pectin or chitosan had lower free fatty acid content, and lipid oxidation values than samples without biopolymer encapsulation. Moreover, the lipase activity decreased, after in vitro digestion, in egg yolks encapsulated with biopolymers. These results improve our understanding of the effects of digestion on total lipids and cholesterol in egg yolk within the gastrointestinal tract.

The Effects of Biopolymer Encapsulation on Total Lipids and Cholesterol in Egg Yolk during in Vitro Human Digestion

Science.gov (United States)

Hur, Sun-Jin; Kim, Young-Chan; Choi, Inwook; Lee, Si-Kyung

2013-01-01

The purpose of this study was to examine the effect of biopolymer encapsulation on the digestion of total lipids and cholesterol in egg yolk using an in vitro human digestion model. Egg yolks were encapsulated with 1% cellulose, pectin, or chitosan. The samples were then passed through an in vitro human digestion model that simulated the composition of mouth saliva, stomach acid, and the intestinal juice of the small intestine by using a dialysis tubing system. The change in digestion of total lipids was monitored by confocal fluorescence microscopy. The digestion rate of total lipids and cholesterol in all egg yolk samples dramatically increased after in vitro human digestion. The digestion rate of total lipids and cholesterol in egg yolks encapsulated with chitosan or pectin was reduced compared to the digestion rate of total lipids and cholesterol in other egg yolk samples. Egg yolks encapsulated with pectin or chitosan had lower free fatty acid content, and lipid oxidation values than samples without biopolymer encapsulation. Moreover, the lipase activity decreased, after in vitro digestion, in egg yolks encapsulated with biopolymers. These results improve our understanding of the effects of digestion on total lipids and cholesterol in egg yolk within the gastrointestinal tract. PMID:23965957

Use of electronic sales data to tailor nutrition education resources for an ethnically diverse population.

Science.gov (United States)

Eyles, H; Rodgers, A; Ni Mhurchu, C

2010-02-01

Nutrition education may be most effective when personally tailored. Individualised electronic supermarket sales data offer opportunities to tailor nutrition education using shopper's usual food purchases. The present study aimed to use individualised electronic supermarket sales data to tailor nutrition resources for an ethnically diverse population in a large supermarket intervention trial in New Zealand. Culturally appropriate nutrition education resources (i.e. messages and shopping lists) were developed with the target population (through two sets of focus groups) and ethnic researchers. A nutrient database of supermarket products was developed using retrospective sales data and linked to participant sales to allow tailoring by usual food purchases. Modified Heart Foundation Tick criteria were used to identify 'healthier' products in the database suitable for promotion in the resources. Rules were developed to create a monthly report listing the tailored and culturally targeted messages to be sent to each participant, and to produce automated, tailored shopping lists. Culturally targeted nutrition messages (n = 864) and shopping lists (n = 3 formats) were developed. The food and nutrient database (n = 3000 top-selling products) was created using 12 months of retrospective sales data, and comprised 60%'healthier' products. Three months of baseline sales data were used to determine usual food purchases. Tailored resources were successfully mailed to 123 Māori, 52 Pacific and 346 non-Māori non-Pacific participants over the 6-month trial intervention period. Electronic supermarket sales data can be used to tailor nutrition education resources for a large number of ethnically diverse supermarket shoppers.

Synthesis of nanohydrogels based on tragacanth gum biopolymer and investigation of swelling and drug delivery.

Science.gov (United States)

Sadat Hosseini, Masoomeh; Hemmati, Khadijeh; Ghaemy, Mousa

2016-01-01

The present article deals with preparation of pH responsive nanohydrogels based on tragacanth gum (TG) biopolymer for drug delivery. The nanohydrogels were prepared using different chemical reagents such as 3-aminopropyltriethoxysilane (APTES) modifier and glyceroldiglycidylether (GDE), polyvinyl alcohol (PVA), and glutaraldehyde (GA) as cross-linkers. The obtained nanohydrogels were characterized using different techniques such as scanning electron microscope (SEM), elemental analysis, FT-IR, zeta sizer and thermogravimetric analysis (TGA). The gel content increased with increasing the cross-linkers contents and reached to a maximum of 90%. The swelling behavior of nanohydrogels was investigated in terms of the effect of pH (2.2, 7.4 and 9), temperature (27, 37 and 60°C), and reaction time (2-24h). Loading of Indomethacin (IND) as a model drug showed dependence on the network structure of nanohydrogels. The total in vitro IND release showed dependence on the network structure of nanohydrogels and was in the range of 50-80% at pH 9 after 24h. Copyright © 2015 Elsevier B.V. All rights reserved.

Biopolymers codelivering engineered T cells and STING agonists can eliminate heterogeneous tumors.

Science.gov (United States)

Smith, Tyrel T; Moffett, Howell F; Stephan, Sirkka B; Opel, Cary F; Dumigan, Amy G; Jiang, Xiuyun; Pillarisetty, Venu G; Pillai, Smitha P S; Wittrup, K Dane; Stephan, Matthias T

2017-06-01

Therapies using T cells that are programmed to express chimeric antigen receptors (CAR T cells) consistently produce positive results in patients with hematologic malignancies. However, CAR T cell treatments are less effective in solid tumors for several reasons. First, lymphocytes do not efficiently target CAR T cells; second, solid tumors create an immunosuppressive microenvironment that inactivates T cell responses; and third, solid cancers are typified by phenotypic diversity and thus include cells that do not express proteins targeted by the engineered receptors, enabling the formation of escape variants that elude CAR T cell targeting. Here, we have tested implantable biopolymer devices that deliver CAR T cells directly to the surfaces of solid tumors, thereby exposing them to high concentrations of immune cells for a substantial time period. In immunocompetent orthotopic mouse models of pancreatic cancer and melanoma, we found that CAR T cells can migrate from biopolymer scaffolds and eradicate tumors more effectively than does systemic delivery of the same cells. We have also demonstrated that codelivery of stimulator of IFN genes (STING) agonists stimulates immune responses to eliminate tumor cells that are not recognized by the adoptively transferred lymphocytes. Thus, these devices may improve the effectiveness of CAR T cell therapy in solid tumors and help protect against the emergence of escape variants.

Surface changes of biopolymers PHB and PLLA induced by Ar+ plasma treatment and wet etching

Science.gov (United States)

Slepičková Kasálková, N.; Slepička, P.; Sajdl, P.; Švorčík, V.

2014-08-01

Polymers, especially group of biopolymers find potential application in a wide range of disciplines due to their biodegradability. In biomedical applications these materials can be used as a scaffold or matrix. In this work, the influence of the Ar+ plasma treatment and subsequent wet etching (acetone/water) on the surface properties of polymers were studied. Two biopolymers - polyhydroxybutyrate with 8% polyhydroxyvalerate (PHB) and poly-L-lactic acid (PLLA) were used in these experiments. Modified surface layers were analyzed by different methods. Surface wettability was characterized by determination of water contact angle. Changes in elemental composition of modified surfaces were performed by X-ray Photoelectron Spectroscopy (XPS). Surface morphology and roughness was examined using Atomic Force Microscopy (AFM). Gravimetry method was used to study the mass loss. It was found that the modification from both with plasma and wet etching leads to dramatic changes of surface properties (surface chemistry, morphology and roughness). Rate of changes of these features strongly depends on the modification parameters.

Extraction of alginate biopolymer present in marine alga sargassum filipendula and bioadsorption of metallic ions

Directory of Open Access Journals (Sweden)

Sirlei Jaiana Kleinübing

2013-04-01

Full Text Available This paper studies the bioadsorption of Pb2+, Cu2+, Cd2+ and Zn2+ ions by marine alga Sargassum filipendula and by the alginate biopolymer extracted from this alga. The objective is to evaluate the importance of this biopolymer in removing different metallic ions by the marine alga S. filipendula. In the equilibrium study, the same affinity order was observed for both bioadsorbents: Pb2+ > Cu2+ > Zn2+ > Cd2+. For Pb2+ and Cu2+ ions when the alginate is isolated and acting as bioadsorbents, adsorption capacities greater than those found for the alga were observed, indicating that it is the main component responsible for the removal of metallic ions. For Zn2+ and Cd2+ ions, greater bioadsorption capacities were observed for the alga, indicating that other functional groups of the alga, such as sulfates and amino, are also important in the bioadsorption of these ions.

Availability, Level of Use and Constraints to Use of Electronic Resources by Law Lecturers in Public Universities in Nigeria

Science.gov (United States)

Amusa, Oyintola Isiaka; Atinmo, Morayo

2016-01-01

(Purpose) This study surveyed the level of availability, use and constraints to use of electronic resources among law lecturers in Nigeria. (Methodology) Five hundred and fifty-two law lecturers were surveyed and four hundred and forty-two responded. (Results) Data analysis revealed that the level of availability of electronic resources for the…

Preparation of the polyelectrolyte complex hydrogel of biopolymers via a semi-dissolution acidification sol-gel transition method and its application in solid-state supercapacitors

Science.gov (United States)

Zhao, Jian; Chen, Yu; Yao, Ying; Tong, Zong-Rui; Li, Pu-Wang; Yang, Zi-Ming; Jin, Shao-Hua

2018-02-01

Hydrogels have drawn many attentions as the solid-state electrolytes in flexible solid-state supercapacitors (SCs) recently. Among them, the polyelectrolyte complex hydrogel (PECH) electrolytes of natural polymers are more competitive because of their environmentally friendly property and low cost. However, while mixing two biopolymer solutions with opposite charges, the strong electrostatic interactions between the cationic and anionic biopolymers may result in precipitates instead of hydrogels. Here we report a novel method, semi-dissolution acidification sol-gel transition (SD-A-SGT), for the preparation of the PECH of chitosan (CTS) and sodium alginate (SA), with the controllable sol-gel transition and uniform composition and successfully apply it as the hydrogel electrolyte of solid-state supercapacitors (SCs). The CTS-SA PECH exhibits an extremely high ionic conductivity of 0.051 S·cm-1 and reasonable mechanical properties with a tensile strength of 0.29 MPa and elongation at break of 109.5%. The solid-state SC fabricated with the CTS-SA PECH and conventional polyaniline (PANI) nanowire electrodes provided a high specific capacitance of 234.6 F·g-1 at 5 mV·s-1 and exhibited excellent cycling stability with 95.3% capacitance retention after 1000 cycles. Our work may pave a novel avenue to the preparation of biodegradable PECHs of full natural polymers, and promote the development of environmentally friendly electronic devices.

A systematic review of portable electronic technology for health education in resource-limited settings.

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McHenry, Megan S; Fischer, Lydia J; Chun, Yeona; Vreeman, Rachel C

2017-08-01

The objective of this study is to conduct a systematic review of the literature of how portable electronic technologies with offline functionality are perceived and used to provide health education in resource-limited settings. Three reviewers evaluated articles and performed a bibliography search to identify studies describing health education delivered by portable electronic device with offline functionality in low- or middle-income countries. Data extracted included: study population; study design and type of analysis; type of technology used; method of use; setting of technology use; impact on caregivers, patients, or overall health outcomes; and reported limitations. Searches yielded 5514 unique titles. Out of 75 critically reviewed full-text articles, 10 met inclusion criteria. Study locations included Botswana, Peru, Kenya, Thailand, Nigeria, India, Ghana, and Tanzania. Topics addressed included: development of healthcare worker training modules, clinical decision support tools, patient education tools, perceptions and usability of portable electronic technology, and comparisons of technologies and/or mobile applications. Studies primarily looked at the assessment of developed educational modules on trainee health knowledge, perceptions and usability of technology, and comparisons of technologies. Overall, studies reported positive results for portable electronic device-based health education, frequently reporting increased provider/patient knowledge, improved patient outcomes in both quality of care and management, increased provider comfort level with technology, and an environment characterized by increased levels of technology-based, informal learning situations. Negative assessments included high investment costs, lack of technical support, and fear of device theft. While the research is limited, portable electronic educational resources present promising avenues to increase access to effective health education in resource-limited settings, contingent

Enhancement of Lignin Biopolymer Isolation from Hybrid Poplar by Organosolv Pretreatments

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Miao Wu

2014-01-01

Full Text Available Lignocellulosic biomass is an abundant renewable resource that has the potential to displace petroleum in the production of biomaterials and biofuels. In the present study, the fractionation of different lignin biopolymers from hybrid poplar based on organosolv pretreatments using 80% aqueous methanol, ethanol, 1-propanol, and 1-butanol at 220°C for 30 min was investigated. The isolated lignin fractions were characterized by Fourier transform infrared spectroscopy (FT-IR, high-performance anion exchange chromatography (HPAEC, 2D nuclear magnetic resonance (2D NMR, and thermogravimetric analysis (TGA. The results showed that the lignin fraction obtained with aqueous ethanol (EOL possessed the highest yield and the strongest thermal stability compared with other lignin fractions. In addition, other lignin fractions were almost absent of neutral sugars (1.16–1.46% though lignin preparation extracted with 1-butanol (BOL was incongruent (7.53%. 2D HSQC spectra analysis revealed that the four lignin fractions mainly consisted of β-O-4′ linkages combined with small amounts of β-β′ and β-5′ linkages. Furthermore, substitution of Cα in β-O-4′ substructures had occurred due to the effects of dissolvent during the autocatalyzed alcohol organosolv pretreatments. Therefore, aqueous ethanol was found to be the most promising alcoholic organic solvent compared with other alcohols to be used in noncatalyzed processes for the pretreatment of lignocellulosic biomass in biorefinery.

SAGES: a suite of freely-available software tools for electronic disease surveillance in resource-limited settings.

Directory of Open Access Journals (Sweden)

Sheri L Lewis

Full Text Available Public health surveillance is undergoing a revolution driven by advances in the field of information technology. Many countries have experienced vast improvements in the collection, ingestion, analysis, visualization, and dissemination of public health data. Resource-limited countries have lagged behind due to challenges in information technology infrastructure, public health resources, and the costs of proprietary software. The Suite for Automated Global Electronic bioSurveillance (SAGES is a collection of modular, flexible, freely-available software tools for electronic disease surveillance in resource-limited settings. One or more SAGES tools may be used in concert with existing surveillance applications or the SAGES tools may be used en masse for an end-to-end biosurveillance capability. This flexibility allows for the development of an inexpensive, customized, and sustainable disease surveillance system. The ability to rapidly assess anomalous disease activity may lead to more efficient use of limited resources and better compliance with World Health Organization International Health Regulations.

Use and Cost of Electronic Resources in Central Library of Ferdowsi University Based on E-metrics

Directory of Open Access Journals (Sweden)

Mohammad Reza Davarpanah

2012-07-01

Full Text Available The purpose of this study was to investigate the usage of electronic journals in Ferdowsi University, Iran based on e-metrics. The paper also aimed to emphasize the analysis of cost-benefit and the correlation between the journal impact factors and the usage data. In this study experiences of Ferdowsi University library on licensing and usage of electronic resources was evaluated by providing a cost-benefit analysis based on the cost and usage statistics of electronic resources. Vendor-provided data were also compared with local usage data. The usage data were collected by tracking web-based access locally, and by collecting vender-provided usage data. The data sources were one-year of vendor-supplied e-resource usage data such as Ebsco, Elsevier, Proquest, Emerald, Oxford and Springer and local usage data collected from the Ferdowsi university web server. The study found that actual usage values differ for vendor-provided data and local usage data. Elsevier has got the highest usage degree in searches, sessions and downloads. Statistics also showed that a small number of journals satisfy significant amount of use while the majority of journals were used less frequent and some were never used at all. The users preferred the PDF rather than HTML format. The data in subject profile suggested that the provided e-resources were best suited to certain subjects. There was no correlation between IF and electronic journal use. Monitoring the usage of e-resources gained increasing importance for acquisition policy and budget decisions. The article provided information about local metrics for the six surveyed vendors/publishers, e.g. usage trends, requests per package, cost per use as related to the scientific specialty of the university.

Proton Conductivity Studies on Biopolymer Electrolytes

International Nuclear Information System (INIS)

Harun, N. I.; Sabri, N. S.; Rosli, N. H. A.; Taib, M. F. M.; Saaid, S. I. Y.; Kudin, T. I. T.; Ali, A. M. M.; Yahya, M. Z. A.

2010-01-01

Proton conducting solid biopolymer electrolyte membranes consisting of methyl cellulose (MC) and different wt.% of ammonium nitrate (NH 4 NO 3 ) were prepared by solution cast technique. Impedance spectroscopy was carried out to study electrical characteristics of bulk materials. The ionic conductivity of the prepared samples was calculated using the bulk resistance (R b ) obtained from impedance spectroscopy plot. The highest ionic conductivity obtained was 1.17x10 -4 Scm -1 for the sample with composition ratio of MC(50): NH 4 NO 3 (50). To enhance the ionic conductivity, propylene carbonate (PC) and ethylene carbonate (EC) plasticizers were introduced. It was found that the ionic conductivity of polymer electrolyte membranes increased with the increase in plasticizers concentration. The ionic conductivities of solid polymer electrolytes based on MC-NH 4 NO 3 -PC was enhanced up to 4.91x10 -3 Scm -1 while for the MC-NH 4 NO 3 -EC system, the highest conductivity was 1.74x10 -2 Scm -1 . The addition of more plasticizer however decreases in mechanical stability of the membranes.

Customizable Biopolymers for Heavy Metal Remediation

International Nuclear Information System (INIS)

Kostal, Jan; Prabhukumar, Giridhar; Lao, U. Loi; Chen Alin; Matsumoto, Mark; Mulchandani, Ashok; Chen, Wilfred

2005-01-01

Nanoscale materials have been gaining increasing interest in the area of environmental remediation because of their unique physical, chemical and biological properties. One emerging area of research has been the development of novel materials with increased affinity, capacity, and selectivity for heavy metals because conventional technologies are often inadequate to reduce concentrations in wastewater to acceptable regulatory standards. Genetic and protein engineering have emerged as the latest tools for the construction of nanoscale materials that can be controlled precisely at the molecular level. With the advent of recombinant DNA techniques, it is now possible to create 'artificial' protein polymers with fundamentally new molecular organization. The most significant feature of these nanoscale biopolymers is that they are specifically pre-programmed within a synthetic gene template and can be controlled precisely in terms of sizes, compositions and functions at the molecular level. In this review, the use of specifically designed protein-based nano-biomaterials with both metal-binding and tunable properties for heavy metal removal is summarized. Several different strategies for the selective removal of heavy metals such as cadmium and mercury are highlighted

Quercetin as natural stabilizing agent for bio-polymer

Energy Technology Data Exchange (ETDEWEB)

Morici, Elisabetta [Dipartimento di Ingegneria Chimica, Gestionale, Informatica, Meccanica, Università di Palermo, 90128 Palermo (Italy); Arrigo, Rossella; Dintcheva, Nadka Tzankova [Dipartimento di Ingegneria Civile, Ambientale, Aerospaziale, dei Materiali, Università di Palermo, 90128 Palermo (Italy)

2014-05-15

The introduction of antioxidants in polymers is the main way to prevent or delay the degradation process. In particular natural antioxidants receive attention in the food industry also because of their presumed safety. In this work bio-polymers, i.e. a commercial starch-based polymer (Mater-Bi®) and a bio-polyester (PLA), and a bio-polyether (PEO) were additivated with quercetin, a natural flavonoid antioxidants, in order to formulate bio-based films for ecosustainable packaging and outdoor applications. The photo-oxidation behavior of unstabilized and quercetin stabilized films was analyzed and compared with the behavior of films additivated with a commercial synthetic light stabilizer. The quercetin is able to slow down the photo-degradation rate of all bio-polymeric films investigated in similar way to the synthetic stabilizer.

Quercetin as natural stabilizing agent for bio-polymer

Science.gov (United States)

Morici, Elisabetta; Arrigo, Rossella; Dintcheva, Nadka Tzankova

2014-05-01

The introduction of antioxidants in polymers is the main way to prevent or delay the degradation process. In particular natural antioxidants receive attention in the food industry also because of their presumed safety. In this work bio-polymers, i.e. a commercial starch-based polymer (Mater-Bi®) and a bio-polyester (PLA), and a bio-polyether (PEO) were additivated with quercetin, a natural flavonoid antioxidants, in order to formulate bio-based films for ecosustainable packaging and outdoor applications. The photo-oxidation behavior of unstabilized and quercetin stabilized films was analyzed and compared with the behavior of films additivated with a commercial synthetic light stabilizer. The quercetin is able to slow down the photo-degradation rate of all bio-polymeric films investigated in similar way to the synthetic stabilizer.

Quercetin as natural stabilizing agent for bio-polymer

International Nuclear Information System (INIS)

Morici, Elisabetta; Arrigo, Rossella; Dintcheva, Nadka Tzankova

2014-01-01

The introduction of antioxidants in polymers is the main way to prevent or delay the degradation process. In particular natural antioxidants receive attention in the food industry also because of their presumed safety. In this work bio-polymers, i.e. a commercial starch-based polymer (Mater-Bi®) and a bio-polyester (PLA), and a bio-polyether (PEO) were additivated with quercetin, a natural flavonoid antioxidants, in order to formulate bio-based films for ecosustainable packaging and outdoor applications. The photo-oxidation behavior of unstabilized and quercetin stabilized films was analyzed and compared with the behavior of films additivated with a commercial synthetic light stabilizer. The quercetin is able to slow down the photo-degradation rate of all bio-polymeric films investigated in similar way to the synthetic stabilizer

Building and Managing Electronic Resources in Digital Era in India with Special Reference to IUCAA and NIV, Pune: A Comparative Case Study

Science.gov (United States)

Sahu, H. K.; Singh, S. N.

2015-04-01

This paper discusses and presents a comparative case study of two libraries in Pune, India, Inter-University Centre for Astronomy and Astrophysics and Information Centre and Library of National Institute of Virology (Indian Council of Medical Research). It compares how both libraries have managed their e-resource collections, including acquisitions, subscriptions, and consortia arrangements, while also developing a collection of their own resources, including pre-prints and publications, video lectures, and other materials in an institutional repository. This study illustrates how difficult it is to manage electronic resources in a developing country like India, even though electronic resources are used more than print resources. Electronic resource management can be daunting, but with a systematic approach, various problems can be solved, and use of the materials will be enhanced.

Metrologically Traceable Determination of the Water Content in Biopolymers: INRiM Activity

Science.gov (United States)

Rolle, F.; Beltramino, G.; Fernicola, V.; Sega, M.; Verdoja, A.

2017-03-01

Water content in materials is a key factor affecting many chemical and physical properties. In polymers of biological origin, it influences their stability and mechanical properties as well as their biodegradability. The present work describes the activity carried out at INRiM on the determination of water content in samples of a commercial starch-derived biopolymer widely used in shopping bags (Mater-Bi^{circledR }). Its water content, together with temperature, is the most influencing parameter affecting its biodegradability, because of the considerable impact on the microbial activity which is responsible for the biopolymer degradation in the environment. The main scope of the work was the establishment of a metrologically traceable procedure for the determination of water content by using two electrochemical methods, namely coulometric Karl Fischer (cKF) titration and evolved water vapour (EWV) analysis. The obtained results are presented. The most significant operational parameters were considered, and a particular attention was devoted to the establishment of metrological traceability of the measurement results by using appropriate calibration procedures, calibrated standards and suitable certified reference materials. Sample homogeneity and oven-drying temperature were found to be the most important influence quantities in the whole water content measurement process. The results of the two methods were in agreement within the stated uncertainties. Further development is foreseen for the application of cKF and EWV to other polymers.

Terpene and dextran renewable resources for the synthesis of amphiphilic biopolymers.

Science.gov (United States)

Alvès, Marie-Hélène; Sfeir, Huda; Tranchant, Jean-François; Gombart, Emilie; Sagorin, Gilles; Caillol, Sylvain; Billon, Laurent; Save, Maud

2014-01-13

The present work shows the synthesis of amphiphilic polymers based on the hydrophilic dextran and the hydrophobic terpenes as renewable resources. The first step concerns the synthesis of functional terpene molecules by thiol-ene addition chemistry involving amino or carboxylic acid thiols and dihydromyrcenol terpene. The terpene-modified polysaccharides were subsequently synthesized by coupling the functional terpenes with dextran. A reductive amination step produced terpene end-modified dextran with 94% of functionalization, while the esterification step produced three terpene-grafted dextrans with a number of terpene units per dextran of 1, 5, and 10. The amphiphilic renewable grafted polymers were tested as emulsifiers for the stabilization of liquid miniemulsion of terpene droplets dispersed in an aqueous phase. The average hydrodynamic diameter of the stable droplets was observed at about 330 nm.

Viscoplastic fracture transition of a biopolymer gel.

Science.gov (United States)

Frieberg, Bradley R; Garatsa, Ray-Shimry; Jones, Ronald L; Bachert, John O; Crawshaw, Benjamin; Liu, X Michael; Chan, Edwin P

2018-06-13

Physical gels are swollen polymer networks consisting of transient crosslink junctions associated with hydrogen or ionic bonds. Unlike covalently crosslinked gels, these physical crosslinks are reversible thus enabling these materials to display highly tunable and dynamic mechanical properties. In this work, we study the polymer composition effects on the fracture behavior of a gelatin gel, which is a thermoreversible biopolymer gel consisting of denatured collagen chains bridging physical network junctions formed from triple helices. Below the critical volume fraction for chain entanglement, which we confirm via neutron scattering measurements, we find that the fracture behavior is consistent with a viscoplastic type process characterized by hydrodynamic friction of individual polymer chains through the polymer mesh to show that the enhancement in fracture scales inversely with the squared of the mesh size of the gelatin gel network. Above this critical volume fraction, the fracture process can be described by the Lake-Thomas theory that considers fracture as a chain scission process due to chain entanglements.

Column adsorption of perchlorate by amine-crosslinked biopolymer based resin and its biological, chemical regeneration properties.

Science.gov (United States)

Song, Wen; Xu, Xing; Tan, Xin; Wang, Yan; Ling, Jianya; Gao, Baoyu; Yue, Qinyan

2015-01-22

Column adsorption of perchlorate by amine-crosslinked biopolymer based resin was investigated by considering the bed depth, stream flow rate and influent pH. The empty bed contact time (EBCT) increased with the growth of bed depths, meanwhile rising flow rate at constant bed depth (3.4 cm) decreased the breakthrough time. It was observed that perchlorate adsorption capacity was optimum at neutral condition (pH: 6.0, 170.4 mg/g), and decreased at acidic (pH: 3.0, 96.4 mg/g) or alkalic (pH: 12.0, 72.8 mg/g) influents. The predominant strains of the acclimated sludge for resin biological regeneration were the β-subclass of Proteobacteria. Biological regeneration of the saturated amine-crosslinked biopolymer based resin with mixed bacteria have shown its merit with regeneration and biological perchlorate destruction simultaneously, although its regeneration efficiency was only 61.2-84.1% by contrast to chemical regeneration with efficiency more than 95%. Copyright © 2014 Elsevier Ltd. All rights reserved.

Surface changes of biopolymers PHB and PLLA induced by Ar{sup +} plasma treatment and wet etching

Energy Technology Data Exchange (ETDEWEB)

Slepičková Kasálková, N. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Slepička, P., E-mail: petr.slepicka@vscht.cz [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Sajdl, P. [Department of Power Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Švorčík, V. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic)

2014-08-01

Polymers, especially group of biopolymers find potential application in a wide range of disciplines due to their biodegradability. In biomedical applications these materials can be used as a scaffold or matrix. In this work, the influence of the Ar{sup +} plasma treatment and subsequent wet etching (acetone/water) on the surface properties of polymers were studied. Two biopolymers – polyhydroxybutyrate with 8% polyhydroxyvalerate (PHB) and poly-L-lactic acid (PLLA) were used in these experiments. Modified surface layers were analyzed by different methods. Surface wettability was characterized by determination of water contact angle. Changes in elemental composition of modified surfaces were performed by X-ray Photoelectron Spectroscopy (XPS). Surface morphology and roughness was examined using Atomic Force Microscopy (AFM). Gravimetry method was used to study the mass loss. It was found that the modification from both with plasma and wet etching leads to dramatic changes of surface properties (surface chemistry, morphology and roughness). Rate of changes of these features strongly depends on the modification parameters.

Layer-by-layer assembled biopolymer microcapsule with separate layer cavities generated by gas-liquid microfluidic approach.

Science.gov (United States)

Wang, Yifeng; Zhou, Jing; Guo, Xuecheng; Hu, Qian; Qin, Chaoran; Liu, Hui; Dong, Meng; Chen, Yanjun

2017-12-01

In this work, a layer-by-layer (LbL) assembled biopolymer microcapsule with separate layer cavities is generated by a novel and convenient gas-liquid microfluidic approach. This approach exhibits combined advantages of microfluidic approach and LbL assembly method, and it can straightforwardly build LbL-assembled capsules in mild aqueous environments at room temperature. In particular, using this approach we can build the polyelectrolyte multilayer capsule with favorable cavities in each layer, and without the need for organic solvent, emulsifying agent, or sacrificial template. Various components (e.g., drugs, proteins, fluorescent dyes, and nanoparticles) can be respectively encapsulated in the separate layer cavities of the LbL-assembled capsules. Moreover, the encapsulated capsules present the ability as colorimetric sensors, and they also exhibit the interesting release behavior. Therefore, the LbL-assembled biopolymer capsule is a promising candidate for biomedical applications in targeted delivery, controlled release, and bio-detection. Copyright © 2017 Elsevier B.V. All rights reserved.

Importance of coccolithophore-associated organic biopolymers for fractionating particle-reactive radionuclides (234Th, 233Pa, 210Pb, 210Po, and 7Be) in the ocean

Science.gov (United States)

Lin, Peng; Xu, Chen; Zhang, Saijin; Sun, Luni; Schwehr, Kathleen A.; Bretherton, Laura; Quigg, Antonietta; Santschi, Peter H.

2017-08-01

Laboratory incubation experiments using the coccolithophore Emiliania huxleyi were conducted in the presence of 234Th, 233Pa, 210Pb, 210Po, and 7Be to differentiate radionuclide uptake to the CaCO3 coccosphere from coccolithophore-associated biopolymers. The coccosphere (biogenic calcite exterior and its associated biopolymers), extracellular (nonattached and attached exopolymeric substances), and intracellular (sodium-dodecyl-sulfate extractable and Fe-Mn-associated metabolites) fractions were obtained by sequentially extraction after E. huxleyi reached its stationary growth phase. Radionuclide partitioning and the composition of different organic compound classes, including proteins, total carbohydrates (TCHO), and uronic acids (URA), were assessed. 210Po was closely associated with the more hydrophobic biopolymers (high protein/TCHO ratio, e.g., in attached exopolymeric substances), while 234Th and 233Pa showed similar partitioning behavior with most activity being distributed in URA-enriched, nonattached exopolymeric substances and intracellular biopolymers. 234Th and 233Pa were nearly undetectable in the coccosphere, with a minor abundance of organic components in the associated biopolymers. These findings provide solid evidence that biogenic calcite is not the actual main carrier phase for Th and Pa isotopes in the ocean. In contrast, both 210Pb and 7Be were found to be mostly concentrated in the CaCO3 coccosphere, likely substituting for Ca2+ during coccolith formation. Our results demonstrate that even small cells (E. huxleyi) can play an important role in the scavenging and fractionation of radionuclides. Furthermore, the distinct partitioning behavior of radionuclides in diatoms (previous studies) and coccolithophores (present study) explains the difference in the scavenging of radionuclides between diatom- and coccolithophore-dominated marine environments.

Novel synthesis and characterization of a collagen-based biopolymer initiated by hydroxyapatite nanoparticles.

Science.gov (United States)

Bhuiyan, D; Jablonsky, M J; Kolesov, I; Middleton, J; Wick, T M; Tannenbaum, R

2015-03-01

In this study, we developed a novel synthesis method to create a complex collagen-based biopolymer that promises to possess the necessary material properties for a bone graft substitute. The synthesis was carried out in several steps. In the first step, a ring-opening polymerization reaction initiated by hydroxyapatite nanoparticles was used to polymerize d,l-lactide and glycolide monomers to form poly(lactide-co-glycolide) co-polymer. In the second step, the polymerization product was coupled with succinic anhydride, and subsequently was reacted with N-hydroxysuccinimide in the presence of dicyclohexylcarbodiimide as the cross-linking agent, in order to activate the co-polymer for collagen attachment. In the third and final step, the activated co-polymer was attached to calf skin collagen type I, in hydrochloric acid/phosphate buffer solution and the precipitated co-polymer with attached collagen was isolated. The synthesis was monitored by proton nuclear magnetic resonance, infrared and Raman spectroscopies, and the products after each step were characterized by thermal and mechanical analysis. Calculations of the relative amounts of the various components, coupled with initial dynamic mechanical analysis testing of the resulting biopolymer, afforded a preliminary assessment of the structure of the complex biomaterial formed by this novel polymerization process. Copyright © 2015. Published by Elsevier Ltd.

[Use of internet and electronic resources among Spanish intensivist physicians. First national survey].

Science.gov (United States)

Gómez-Tello, V; Latour-Pérez, J; Añón Elizalde, J M; Palencia-Herrejón, E; Díaz-Alersi, R; De Lucas-García, N

2006-01-01

Estimate knowledge and use habits of different electronic resources in a sample of Spanish intensivists: Internet, E-mail, distribution lists, and use of portable electronic devices. Self-applied questionnaire. A 50-question questionnaire was distributed among Spanish intensivists through the hospital marketing delegates of a pharmaceutical company and of electronic forums. A total of 682 questionnaires were analyzed (participation: 74%). Ninety six percent of those surveyed used Internet individually: 67% admitted training gap. Internet was the second source of clinical consultations most used (61%), slightly behind consultation to colleagues (65%). The pages consulted most were bibliographic databases (65%) and electronic professional journals (63%), with limited use of Evidence Based Medicine pages (19%). Ninety percent of those surveyed used e-mail regularly in the practice of their profession, although 25% admitted that were not aware of its possibilities. The use of E-mail decreased significantly with increase in age. A total of 62% of the intensivists used distribution lists. Of the rest, 42% were not aware of its existence and 32% admitted they had insufficient training to handle them. Twenty percent of those surveyed had portable electronic devices and 64% considered it useful, basically due to its rapid consultation at bedside. Female gender was a negative predictive factor of its use (OR 0.35; 95% CI 0.2-0.63; p=0.0002). A large majority of the Spanish intensivists use Internet and E-mail. E-mail lists and use of portable devices are still underused resources. There are important gaps in training and infrequent use of essential pages. There are specific groups that require directed educational policies.

Electrospun fibers of layered double hydroxide/biopolymer nanocomposites as effective drug delivery systems

Energy Technology Data Exchange (ETDEWEB)

Miao, Yue-E.; Zhu Hong; Chen Dan; Wang Ruiyu [State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai 200433 (China); Tjiu, Weng Weei [Institute of Materials Research and Engineering, A-STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602 (Singapore); Liu Tianxi, E-mail: txliu@fudan.edu.cn [State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai 200433 (China)

2012-06-15

Ibuprofen intercalated layered double hydroxide (LDH-IBU)/polycaprolactone (PCL) and LDH-IBU/polylactide (PLA) nanocomposite fibers are electrospun based on a combination of LDH-IBU with two kinds of biopolymers (i.e. PCL and PLA), to act as effective drug delivery systems. Ibuprofen (IBU) is chosen as a model drug, which is intercalated in MgAl-LDH by coprecipitation. Poly(oxyethylene-b-oxypropylene-b-oxyethylene) (Pluronic) is also added into PLA-based fibers as hydrophilicity enhancer and release modulator. LDH-IBU nanoparticles are uniformly dispersed throughout the nanocomposite fibers, as evidenced by transmission electron microscopy (TEM) observations. In vitro drug release studies show that initial IBU liberation from LDH-IBU/PCL composite fibers is remarkably slower than that from IBU/PCL fibers due to the sustained release property of LDH-IBU and heterogeneous nucleation effect of LDH-IBU on PCL chain segments. Surprisingly, the initial IBU release from LDH-IBU/PLA and LDH-IBU/PLA/Pluronic composite fibers is faster than that from the corresponding IBU/PLA and IBU/PLA/Pluronic fibers. This effect can be attributed to the strong interaction between alkyl groups in IBU molecules and methyl substituent groups of PLA as well as the hydrophilicity of LDH-IBU, which lead to an easier diffusion of water with a faster release of IBU from LDH-IBU/PLA and LDH-IBU/PLA/Pluronic composite fibers. - Graphical abstract: Ibuprofen intercalated layered double hydroxide (LDH-IBU)/polycaprolactone (PCL) and LDH-IBU/polylactide (PLA) nanocomposite fibers are electrospun based on the combination of LDHs with two kinds of biopolymers (i.e. PCL and PLA). LDH-IBU nanoparticles are uniformly dispersed throughout all the electrospun nanocomposite fibers even at a high loading level of 5 wt%. By combining the tunable drug release property of LDHs and electrospinning technique, the new drug delivery system is anticipated for effective loading and sustained release of drugs

Electrospun fibers of layered double hydroxide/biopolymer nanocomposites as effective drug delivery systems

International Nuclear Information System (INIS)

Miao, Yue-E.; Zhu Hong; Chen Dan; Wang Ruiyu; Tjiu, Weng Weei; Liu Tianxi

2012-01-01

Ibuprofen intercalated layered double hydroxide (LDH-IBU)/polycaprolactone (PCL) and LDH-IBU/polylactide (PLA) nanocomposite fibers are electrospun based on a combination of LDH-IBU with two kinds of biopolymers (i.e. PCL and PLA), to act as effective drug delivery systems. Ibuprofen (IBU) is chosen as a model drug, which is intercalated in MgAl-LDH by coprecipitation. Poly(oxyethylene-b-oxypropylene-b-oxyethylene) (Pluronic) is also added into PLA-based fibers as hydrophilicity enhancer and release modulator. LDH-IBU nanoparticles are uniformly dispersed throughout the nanocomposite fibers, as evidenced by transmission electron microscopy (TEM) observations. In vitro drug release studies show that initial IBU liberation from LDH-IBU/PCL composite fibers is remarkably slower than that from IBU/PCL fibers due to the sustained release property of LDH-IBU and heterogeneous nucleation effect of LDH-IBU on PCL chain segments. Surprisingly, the initial IBU release from LDH-IBU/PLA and LDH-IBU/PLA/Pluronic composite fibers is faster than that from the corresponding IBU/PLA and IBU/PLA/Pluronic fibers. This effect can be attributed to the strong interaction between alkyl groups in IBU molecules and methyl substituent groups of PLA as well as the hydrophilicity of LDH-IBU, which lead to an easier diffusion of water with a faster release of IBU from LDH-IBU/PLA and LDH-IBU/PLA/Pluronic composite fibers. - Graphical abstract: Ibuprofen intercalated layered double hydroxide (LDH-IBU)/polycaprolactone (PCL) and LDH-IBU/polylactide (PLA) nanocomposite fibers are electrospun based on the combination of LDHs with two kinds of biopolymers (i.e. PCL and PLA). LDH-IBU nanoparticles are uniformly dispersed throughout all the electrospun nanocomposite fibers even at a high loading level of 5 wt%. By combining the tunable drug release property of LDHs and electrospinning technique, the new drug delivery system is anticipated for effective loading and sustained release of drugs

Model of e-learning with electronic educational resources of new generation

OpenAIRE

A. V. Loban; D. A. Lovtsov

2017-01-01

Purpose of the article: improving of scientific and methodical base of the theory of the е-learning of variability. Methods used: conceptual and logical modeling of the е-learning of variability process with electronic educational resource of new generation and system analysis of the interconnection of the studied subject area, methods, didactics approaches and information and communication technologies means. Results: the formalization complex model of the е-learning of variability with elec...

Highly Stable, Functional Hairy Nanoparticles and Biopolymers from Wood Fibers: Towards Sustainable Nanotechnology.

Science.gov (United States)

Sheikhi, Amir; Yang, Han; Alam, Md Nur; van de Ven, Theo G M

2016-07-20

Nanoparticles, as one of the key materials in nanotechnology and nanomedicine, have gained significant importance during the past decade. While metal-based nanoparticles are associated with synthetic and environmental hassles, cellulose introduces a green, sustainable alternative for nanoparticle synthesis. Here, we present the chemical synthesis and separation procedures to produce new classes of hairy nanoparticles (bearing both amorphous and crystalline regions) and biopolymers based on wood fibers. Through periodate oxidation of soft wood pulp, the glucose ring of cellulose is opened at the C2-C3 bond to form 2,3-dialdehyde groups. Further heating of the partially oxidized fibers (e.g., T = 80 °C) results in three products, namely fibrous oxidized cellulose, sterically stabilized nanocrystalline cellulose (SNCC), and dissolved dialdehyde modified cellulose (DAMC), which are well separated by intermittent centrifugation and co-solvent addition. The partially oxidized fibers (without heating) were used as a highly reactive intermediate to react with chlorite for converting almost all aldehyde to carboxyl groups. Co-solvent precipitation and centrifugation resulted in electrosterically stabilized nanocrystalline cellulose (ENCC) and dicarboxylated cellulose (DCC). The aldehyde content of SNCC and consequently surface charge of ENCC (carboxyl content) were precisely controlled by controlling the periodate oxidation reaction time, resulting in highly stable nanoparticles bearing more than 7 mmol functional groups per gram of nanoparticles (e.g., as compared to conventional NCC bearing AFM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) attested to the rod-like morphology. Conductometric titration, Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), dynamic light scattering (DLS), electrokinetic-sonic-amplitude (ESA) and acoustic attenuation spectroscopy shed light on the superior properties of these

Impact of Knowledge Resources Linked to an Electronic Health Record on Frequency of Unnecessary Tests and Treatments

Science.gov (United States)

Goodman, Kenneth; Grad, Roland; Pluye, Pierre; Nowacki, Amy; Hickner, John

2012-01-01

Introduction: Electronic knowledge resources have the potential to rapidly provide answers to clinicians' questions. We sought to determine clinicians' reasons for searching these resources, the rate of finding relevant information, and the perceived clinical impact of the information they retrieved. Methods: We asked general internists, family…

Electronic Document Management: A Human Resource Management Case Study

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Thomas Groenewald

2004-11-01

Full Text Available This case study serve as exemplar regarding what can go wrong with the implementation of an electronic document management system. Knowledge agility and knowledge as capital, is outlined against the backdrop of the information society and knowledge economy. The importance of electronic document management and control is sketched thereafter. The literature review is concluded with the impact of human resource management on knowledge agility, which includes references to the learning organisation and complexity theory. The intervention methodology, comprising three phases, follows next. The results of the three phases are presented thereafter. Partial success has been achieved with improving the human efficacy of electronic document management, however the client opted to discontinue the system in use. Opsomming Die gevalle studie dien as voorbeeld van wat kan verkeerd loop met die implementering van ’n elektroniese dokumentbestuur sisteem. Teen die agtergrond van die inligtingsgemeenskap en kennishuishouding word kennissoepelheid en kennis as kapitaal bespreek. Die literatuurstudie word afgesluit met die inpak van menslikehulpbronbestuur op kennissoepelheid, wat ook die verwysings na die leerorganisasie en kompleksietydsteorie insluit. Die metodologie van die intervensie, wat uit drie fases bestaan, volg daarna. Die resultate van die drie fases word vervolgens aangebied. Slegs gedeelte welslae is behaal met die verbetering van die menslike doeltreffendheid ten opsigte van elektroniese dokumentbestuur. Die klient besluit egter om nie voort te gaan om die huidige sisteem te gebruik nie.

Challenges in the implementation of an electronic surveillance system in a resource-limited setting: Alerta, in Peru

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Soto Giselle

2008-11-01

Full Text Available Abstract Background Infectious disease surveillance is a primary public health function in resource-limited settings. In 2003, an electronic disease surveillance system (Alerta was established in the Peruvian Navy with support from the U.S. Naval Medical Research Center Detachment (NMRCD. Many challenges arose during the implementation process, and a variety of solutions were applied. The purpose of this paper is to identify and discuss these issues. Methods This is a retrospective description of the Alerta implementation. After a thoughtful evaluation according to the Centers for Disease Control and Prevention (CDC guidelines, the main challenges to implementation were identified and solutions were devised in the context of a resource-limited setting, Peru. Results After four years of operation, we have identified a number of challenges in implementing and operating this electronic disease surveillance system. These can be divided into the following categories: (1 issues with personnel and stakeholders; (2 issues with resources in a developing setting; (3 issues with processes involved in the collection of data and operation of the system; and (4 issues with organization at the central hub. Some of the challenges are unique to resource-limited settings, but many are applicable for any surveillance system. For each of these challenges, we developed feasible solutions that are discussed. Conclusion There are many challenges to overcome when implementing an electronic disease surveillance system, not only related to technology issues. A comprehensive approach is required for success, including: technical support, personnel management, effective training, and cultural sensitivity in order to assure the effective deployment of an electronic disease surveillance system.

Constitutive modelling of composite biopolymer networks.

Science.gov (United States)

Fallqvist, B; Kroon, M

2016-04-21

The mechanical behaviour of biopolymer networks is to a large extent determined at a microstructural level where the characteristics of individual filaments and the interactions between them determine the response at a macroscopic level. Phenomena such as viscoelasticity and strain-hardening followed by strain-softening are observed experimentally in these networks, often due to microstructural changes (such as filament sliding, rupture and cross-link debonding). Further, composite structures can also be formed with vastly different mechanical properties as compared to the individual networks. In this present paper, we present a constitutive model presented in a continuum framework aimed at capturing these effects. Special care is taken to formulate thermodynamically consistent evolution laws for dissipative effects. This model, incorporating possible anisotropic network properties, is based on a strain energy function, split into an isochoric and a volumetric part. Generalisation to three dimensions is performed by numerical integration over the unit sphere. Model predictions indicate that the constitutive model is well able to predict the elastic and viscoelastic response of biological networks, and to an extent also composite structures. Copyright © 2016 Elsevier Ltd. All rights reserved.

Invited review nonmulberry silk biopolymers.

Science.gov (United States)

Kundu, S C; Kundu, Banani; Talukdar, Sarmistha; Bano, Subia; Nayak, Sunita; Kundu, Joydip; Mandal, Biman B; Bhardwaj, Nandana; Botlagunta, Mahendran; Dash, Biraja C; Acharya, Chitrangada; Ghosh, Ananta K

2012-06-01

The silk produced by silkworms are biopolymers and can be classified into two types--mulberry and nonmulberry. Mulberry silk of silkworm Bombyx mori has been extensively explored and used for century old textiles and sutures. But for the last few decades it is being extensively exploited for biomedical applications. However, the transformation of nonmulberry silk from being a textile commodity to biomaterials is relatively new. Within a very short period of time, the combination of load bearing capability and tensile strength of nonmulberry silk has been equally envisioned for bone, cartilage, adipose, and other tissue regeneration. Adding to its advantage is its diverse morphology, including macro to nano architectures with controllable degradation and biocompatibility yields novel natural material systems in vitro. Its follow on applications involve sustained release of model compounds and anticancer drugs. Its 3D cancer models provide compatible microenvironment systems for better understanding of the cancer progression mechanism and screening of anticancer compounds. Diversely designed nonmulberry matrices thus provide an array of new cutting age technologies, which is unattainable with the current synthetic materials that lack biodegradability and biocompatibility. Scientific exploration of nonmulberry silk in tissue engineering, regenerative medicine, and biotechnological applications promises advancement of sericulture industries in India and China, largest nonmulberry silk producers of the world. This review discusses the prospective biomedical applications of nonmulberry silk proteins as natural biomaterials. Copyright © 2012 Wiley Periodicals, Inc.

Dissolvable Films of Silk Fibroin for Ultrathin Conformal Bio-Integrated Electronics

Science.gov (United States)

2010-06-01

implantation. *A full list of authors and their affiliations appears at the end of the paper. Silk is an appealing biopolymer as a temporary, soluble...18 APR 2010 2. REPORT TYPE 3. DATES COVERED 00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE Dissolvable films of silk fibroin for ultrathin...10.1038/NMAT2745 Dissolvable films of silk fibroin for ultrathin conformal bio-integrated electronics Dae-Hyeong Kim and Jonathan Viventi et al

Fabrication, functionalization, and application of electrospun biopolymer nanofibers.

Science.gov (United States)

Kriegel, Christina; Arecchi, Alessandra; Arrechi, Alessandra; Kit, Kevin; McClements, D J; Weiss, Jochen

2008-09-01

-fiber manufacturing with a particular emphasis on the use of biopolymers. We will review typical fabrication set-ups, discuss the influence of process conditions on nanofiber properties, and then review previous studies that describe the production of biopolymer-based nanofibers. Finally we briefly discuss emerging methods to further functionalize fibers and discuss potential applications in the area of food science and technology.

Sodium Mercaptoethane Sulfonate Reduces Collagenolytic Degradation and Synergistically Enhances Antimicrobial Durability in an Antibiotic-Loaded Biopolymer Film for Prevention of Surgical-Site Infections

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Joel Rosenblatt

2017-01-01

Full Text Available Implant-associated surgical-site infections can have significant clinical consequences. Previously we reported a method for prophylactically disinfecting implant surfaces in surgical pockets, where an antibiotic solution containing minocycline (M and rifampin (R was applied as a solid film in a crosslinked biopolymer matrix that partially liquefied in situ to provide extended prophylaxis. Here we studied the effect of adding sodium 2-mercaptoethane sulfonate (MeSNA on durability of prophylaxis in an in vitro model of implant-associated surgical-site infection. Adding MeSNA to the M/R biopolymer, antimicrobial film extended the duration for which biofilm formation by multidrug-resistant Pseudomonas aeruginosa (MDR-PA was prevented on silicone surfaces in the model. M/R films with and without MeSNA were effective in preventing colonization by methicillin-resistant Staphylococcus aureus. Independent experiments revealed that MeSNA directly inhibited proteolytic digestion of the biopolymer film and synergistically enhanced antimicrobial potency of M/R against MDR-PA. Incubation of the MeSNA containing films with L929 fibroblasts revealed no impairment of cellular metabolic activity or viability.

Biopolymer Doped with Titanium Dioxide Superhydrophobic Photocatalysis as Self-Clean Coating for Lightweight Composite

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Anika Zafiah M. Rus

2013-01-01

Full Text Available The development of a lightweight composite (LC based on Portland cement concrete with waste lightweight aggregate (WLA additive was carried out to improve the sustainability and environmental impact and to offer potential cost savings without sacrificing strength. Treatment of the surface of the LC exposed to environmental attack by coating with biopolymer based on waste cooking oil doped with titanium dioxide photocatalysis (TOP with superhydrophilic property was found to affect the mechanical properties of the LC in a systematic way. The results of compressive strength showed that the composite achieved the minimum required strength for lightweight construction materials of 17.2 MPa. Scratch resistance measurements showed that the highest percentages loading of superhydrophilic particles (up to 2.5% of biomonomer weight for LC's surface coating gave the highest scratch resistance while the uncoated sample showed the least resistances. Scanning electron microscope (SEM pictures revealed the difference between the surface roughness for LC with and without TOP coating. TOP is also formulated to provide self-cleaning LC surfaces based on two principal ways: (1 the development by coating the LC with a photocatalytic superhydrophilic, (2 if such a superhydrophilic is illuminated by light, the grease, dirt, and organic contaminants will be decomposed and can easily be swept away by rain.

Considering Point-of-Care Electronic Medical Resources in Lieu of Traditional Textbooks for Medical Education.

Science.gov (United States)

Hale, LaDonna S; Wallace, Michelle M; Adams, Courtney R; Kaufman, Michelle L; Snyder, Courtney L

2015-09-01

Selecting resources to support didactic courses is a critical decision, and the advantages and disadvantages must be carefully considered. During clinical rotations, students not only need to possess strong background knowledge but also are expected to be proficient with the same evidence-based POC resources used by clinicians. Students place high value on “real world” learning and therefore may place more value on POC resources that they know practicing clinicians use as compared with medical textbooks. The condensed nature of PA education requires students to develop background knowledge and information literacy skills over a short period. One way to build that knowledge and those skills simultaneously is to use POC resources in lieu of traditional medical textbooks during didactic training. Electronic POC resources offer several advantages over traditional textbooks and should be considered as viable options in PA education.

The stability and degradation kinetics of Sulforaphene in microcapsules based on several biopolymers via spray drying.

Science.gov (United States)

Tian, Guifang; Li, Yuan; Yuan, Qipeng; Cheng, Li; Kuang, Pengqun; Tang, Pingwah

2015-05-20

Sulforaphene (SFE) was extracted from the radish seeds and the purity of SFE extracted by our laboratory was 95%. It is well known that SFE can prevent cancers. It is also known that SFE is unstable to heat. To overcome the problem, SFE microcapsules using natural biopolymers were prepared by spray drying. The results indicated that SFE microcapsules using hydroxypropyl-β-cyclodextrin (HP-β-CD), maltodextrin (MD) and isolated soybean protein (SPI) as wall materials could effectively improve its stability against heat, especially SFE-loaded HP-β-CD and MD microcapsules. The amount of SFE in the microcapsules was found 20% higher than that of the non-encapsulated SFE under 90 °C in 168 h. Our finding suggested that the rate of degradation of the non-encapsulated and encapsulated SFE with HP-β-CD, MD and SPI followed the first-order kinetics. The speed of the degradation of the encapsulated SFE in biopolymers increased from SFE with HP-β-CD, to SFE with MD, and to SFE-SPI. The non-encapsulated SFE degrades fastest. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of γ-irradiation on the physical and mechanical properties of kefiran biopolymer film.

Science.gov (United States)

Shahabi-Ghahfarrokhi, Iman; Khodaiyan, Faramarz; Mousavi, Mohammad; Yousefi, Hossein

2015-03-01

In this study, the effect of different γ-ray dosages (3, 6, and 9 kGy) on the functional properties of kefiran biopolymer was investigated. The obtained results showed that increasing γ-ray dosage brought about an increase in the tensile strength of film specimens up to three-times. However, elongation at break, and tensile energy to break of γ-irradiated kefiran films decreased in the wake of increasing γ-ray dosage. γ-Irradiation could improve surface hydrophobicity, sensitivity of kefiran film specimens to water, and water vapor permeability, but yellowness of films increased, simultaneously. XRD spectrum confirmed increased crystallinity of γ-irradiated films. Melting point of films was constant but glass transition temperature decreased drastically at high γ-ray dosage (9 kGy). ATR-FTIR analysis confirmed that γ-ray engendered no changes in chemical functional groups. According to the result, a mechanism was proposed to percept the effects of γ-irradiation on kefiran biopolymer and its role on the functional properties of kefiran film. Hence, the functional properties of kefiran films were depend on the ratio of cross-linkages between polymer chains and produced mono and disaccharide by γ-irradiation. Copyright © 2014 Elsevier B.V. All rights reserved.

Resource conservation approached with an appropriate collection and upgrade-remanufacturing for used electronic products.

Science.gov (United States)

Zlamparet, Gabriel I; Tan, Quanyin; Stevels, A B; Li, Jinhui

2018-03-01

This comparative research represents an example for a better conservation of resources by reducing the amount of waste (kg) and providing it more value under the umbrella of remanufacturing. The three discussed cases will expose three issues already addressed separately in the literature. The generation of waste electrical and electronic equipment (WEEE) interacts with the environmental depletion. In this article, we gave the examples of addressed issues under the concept of remanufacturing. Online collection opportunity eliminating classical collection, a business to business (B2B) implementation for remanufactured servers and medical devices. The material reuse (recycling), component sustainability, reuse (part harvesting), product reuse (after repair/remanufacturing) indicates the recovery potential using remanufacturing tool for a better conservation of resources adding more value to the products. Our findings can provide an overview of new system organization for the general collection, market potential and the technological advantages using remanufacturing instead of recycling of WEEE or used electrical and electronic equipment. Copyright © 2017. Published by Elsevier Ltd.

Chemical composition and molecular structure of polysaccharide-protein biopolymer from Durio zibethinus seed: extraction and purification process

Directory of Open Access Journals (Sweden)

Amid Bahareh

2012-10-01

Full Text Available Abstract Background The biological functions of natural biopolymers from plant sources depend on their chemical composition and molecular structure. In addition, the extraction and further processing conditions significantly influence the chemical and molecular structure of the plant biopolymer. The main objective of the present study was to characterize the chemical and molecular structure of a natural biopolymer from Durio zibethinus seed. A size-exclusion chromatography coupled to multi angle laser light-scattering (SEC-MALS was applied to analyze the molecular weight (Mw, number average molecular weight (Mn, and polydispersity index (Mw/Mn. Results The most abundant monosaccharide in the carbohydrate composition of durian seed gum were galactose (48.6-59.9%, glucose (37.1-45.1%, arabinose (0.58-3.41%, and xylose (0.3-3.21%. The predominant fatty acid of the lipid fraction from the durian seed gum were palmitic acid (C16:0, palmitoleic acid (C16:1, stearic acid (C18:0, oleic acid (C18:1, linoleic acid (C18:2, and linolenic acid (C18:2. The most abundant amino acids of durian seed gum were: leucine (30.9-37.3%, lysine (6.04-8.36%, aspartic acid (6.10-7.19%, glycine (6.07-7.42%, alanine (5.24-6.14%, glutamic acid (5.57-7.09%, valine (4.5-5.50%, proline (3.87-4.81%, serine (4.39-5.18%, threonine (3.44-6.50%, isoleucine (3.30-4.07%, and phenylalanine (3.11-9.04%. Conclusion The presence of essential amino acids in the chemical structure of durian seed gum reinforces its nutritional value.

Effects of the Use of Electronic Human Resource Management (EHRM Within Human Resource Management (HRM Functions at Universities

Directory of Open Access Journals (Sweden)

Chux Gervase Iwu

2016-09-01

Full Text Available This study set out to examine the effect of e-hrm systems in assisting human resource practitioners to execute their duties and responsibilities. In comparison to developed economies of the world, information technology adoption in sub-Saharan Africa has not been without certain glitches. Some of the factors that are responsible for these include poor need identification, sustainable funding, and insufficient skills. Besides these factors, there is also the issue of change management and users sticking to what they already know. Although, the above factors seem negative, there is strong evidence that information systems such as electronic human resource management present benefits to an organization. To achieve this, a dual research approach was utilized. Literature assisted immensely in both the development of the conceptual framework upon which the study hinged as well as in the development of the questionnaire items. The study also made use of an interview checklist to guide the participants. The findings reveal a mix of responses that indicate that while there are gains in adopting e-hrm systems, it is wiser to consider supporting resources as well as articulate the needs of the university better before any investment is made.

Electronic human resource management: Enhancing or entrancing?

Directory of Open Access Journals (Sweden)

Paul Poisat

2017-07-01

Full Text Available Orientation: This article provides an investigation into the current level of development of the body of knowledge related to electronic human resource management (e-HRM by means of a qualitative content analysis. Several aspects of e-HRM, namely definitions of e-HRM, the theoretical perspectives around e-HRM, the role of e-HRM, the various types of e-HRM and the requirements for successful e-HRM, are examined. Research purpose: The purpose of the article was to determine the status of e-HRM and examine the studies that report on the link between e-HRM and organisational productivity. Motivation for the study: e-HRM has the capacity to improve organisational efficiency and leverage the role of human resources (HR as a strategic business partner. Main findings: The notion that the implementation of e-HRM will lead to improved organisational productivity is commonly assumed; however, empirical evidence in this regard was found to be limited. Practical/managerial implications: From the results of this investigation it is evident that more research is required to gain a greater understanding of the influence of e-HRM on organisational productivity, as well as to develop measures for assessing this influence. Contribution: This article proposes additional areas to research and measure when investigating the effectiveness of e-HRM. It provides a different lens from which to view e-HRM assessment whilst keeping it within recognised HR measurement parameters (the HR value chain. In addition, it not only provides areas for measuring e-HRM’s influence but also provides important clues as to how the measurements may be approached.

Application of guar gum biopolymer in the prescription of tablets with sodium ibuprofen--quality tests and pharmaceutical availability in vitro.

Science.gov (United States)

Berner-Strzelczyk, Aneta; Kołodziejska, Justyna; Zgoda, Marian Mikołaj

2006-01-01

The increasing interest of the technology of drug form in natural biopolymers has become the reason for undertaking investigations on the possibility of guar gum application in the prescription of oral solid form of a drug. Alternative compositions and technology of the production of tablets of regulated in time sodium ibuprofen release were worked out for children. Two series of tablets were prepared with guar gum (5 and 10% content) and a series without the biopolymer. The tablet mass in each case contained keryostatic sorbitol and bioadhesive polyvinylpyrrolidone. All tablets were tested as regards the quality of production, compliance with the requirements of Polish Pharmacopoeia VI and potential therapeutic usefulness, manifestation of which is pharmaceutical availability of the therapeutic agent (sodium ibuprofen). The tests demonstrated that the produced tablets with sodium ibuprofen have proper physicochemical properties, in compliance with Polish Pharmacopoeia VI requirements. Application of biopolymer of guar gum type as adjuvant substance contributes to the improvement of the tablet hardness parameters and prevents technological problems (lining mixture of powders to tableting machine punch). The designed tablets demonstrate proper pharmaceutical availability of over 80%. Introduction of guar gum into their prescription prolonged their disintegration time and the rate of sodium ibuprofen release, which predisposes the produced form of a drug to have the function of a tablet with slowed-down release.

Exploring the energy landscape of biopolymers using single molecule force spectroscopy and molecular simulations

OpenAIRE

Hyeon, Changbong

2010-01-01

In recent years, single molecule force techniques have opened a new avenue to decipher the folding landscapes of biopolymers by allowing us to watch and manipulate the dynamics of individual proteins and nucleic acids. In single molecule force experiments, quantitative analyses of measurements employing sound theoretical models and molecular simulations play central role more than any other field. With a brief description of basic theories for force mechanics and molecular simulation techniqu...

Preformed amide-containing biopolymer for improving the environmental performance of synthesized urea–formaldehyde in agro-fiber composites

Science.gov (United States)

Altaf H. Basta; Houssni El-Saied; Jerrold E. Winandy; Ronald Sabo

2011-01-01

Investigations have continued for production high performance agro-based composites using environmentally acceptable approaches. This study examines the role of adding amide-containing biopolymers during synthesis of urea–formaldehyde (UF) on properties of adhesive produced, especially its adhesion potential. The environmental performance of UF-resin synthesized in the...

Eco-Friendly Extraction of Biopolymer Chitin and Carotenoids from Shrimp Waste

Science.gov (United States)

Prameela, K.; Venkatesh, K.; Divya vani, K.; Sudesh Kumar, E.; Mohan, CH Murali

2017-08-01

Astaxanthin a nutraceutical and chitin a natural biopolymer present in shrimp waste. In current chemical extraction methods HCl and NaOH are used for extraction and these chemicals are introduced into aquatic ecosystems are spoiling aquatic flora and fauna, pollute the environment and destroy astaxanthin. Lactobacillus species were isolated from gut of Solenocera melantho and characterized phenotypically and genotypically. Initial screening experiments have shown to be an effective and identified as Lactobacillus plantaram based on morphological, biochemical characteristics and molecular analysis. Efficiency of fermentation has shown with good yield of astaxanthin and recovery of chitin. Hence this alternative microbial process is having advantage than existing hazardous, non-economical chemical process.

[Distribution and spatial ordering of biopolymer molecules in resting bacterial spores].

Science.gov (United States)

Duda, V I; Korolev, Iu N; El'-Registan, G I; Duzha, M V; Telegin, N L

1978-01-01

The presence, distribution and spatial arrangement of biopolymers in situ were studied in both a total intact spore and in a certain cellular layer using a spectroscopic technique of attenuated total refraction (ATR-IR) in the IR region. In contrast to vegetative cells, intact spores were characterized by isotropic distribution of protein components. This feature can be regarded as an index of the cryptobiotic state of spores. However, the distribution of protein components among individual layers of a spore was anisotropic. Bonds characterized by amide I and amide II bands were most often ordered in a layer which comprised cellular structures from the exosporium to the inner spore membrane.

Identifying and evaluating electronic learning resources for use in adult-gerontology nurse practitioner education.

Science.gov (United States)

Thompson, Hilaire J; Belza, Basia; Baker, Margaret; Christianson, Phyllis; Doorenbos, Ardith; Nguyen, Huong

2014-01-01

Enhancing existing curricula to meet newly published adult-gerontology advanced practice registered nurse (APRN) competencies in an efficient manner presents a challenge to nurse educators. Incorporating shared, published electronic learning resources (ELRs) in existing or new courses may be appropriate in order to assist students in achieving competencies. The purposes of this project were to (a) identify relevant available ELR for use in enhancing geriatric APRN education and (b) to evaluate the educational utility of identified ELRs based on established criteria. A multilevel search strategy was used. Two independent team members reviewed identified ELR against established criteria to ensure utility. Only resources meeting all criteria were retained. Resources were found for each of the competency areas and included formats such as podcasts, Web casts, case studies, and teaching videos. In many cases, resources were identified using supplemental strategies and not through traditional search or search of existing geriatric repositories. Resources identified have been useful to advanced practice educators in improving lecture and seminar content in a particular topic area and providing students and preceptors with additional self-learning resources. Addressing sustainability within geriatric APRN education is critical for sharing of best practices among educators and for sustainability of teaching and related resources. © 2014.

Systematic review of electronic surveillance of infectious diseases with emphasis on antimicrobial resistance surveillance in resource-limited settings.

Science.gov (United States)

Rattanaumpawan, Pinyo; Boonyasiri, Adhiratha; Vong, Sirenda; Thamlikitkul, Visanu

2018-02-01

Electronic surveillance of infectious diseases involves rapidly collecting, collating, and analyzing vast amounts of data from interrelated multiple databases. Although many developed countries have invested in electronic surveillance for infectious diseases, the system still presents a challenge for resource-limited health care settings. We conducted a systematic review by performing a comprehensive literature search on MEDLINE (January 2000-December 2015) to identify studies relevant to electronic surveillance of infectious diseases. Study characteristics and results were extracted and systematically reviewed by 3 infectious disease physicians. A total of 110 studies were included. Most surveillance systems were developed and implemented in high-income countries; less than one-quarter were conducted in low-or middle-income countries. Information technologies can be used to facilitate the process of obtaining laboratory, clinical, and pharmacologic data for the surveillance of infectious diseases, including antimicrobial resistance (AMR) infections. These novel systems require greater resources; however, we found that using electronic surveillance systems could result in shorter times to detect targeted infectious diseases and improvement of data collection. This study highlights a lack of resources in areas where an effective, rapid surveillance system is most needed. The availability of information technology for the electronic surveillance of infectious diseases, including AMR infections, will facilitate the prevention and containment of such emerging infectious diseases. Copyright © 2018 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

From Millennium ERM to Proquest 360 Resource Manager: Implementing a new Electronic Resources Management System ERMS in an International Graduate Research University in Saudi Arabia

KAUST Repository

Ramli, Rindra M.

2017-01-01

An overview of the Recommendation Study and the subsequent Implementation of a new Electronic Resources Management system ERMS in an international graduate research university in the Kingdom of Saudi Arabia. It covers the timeline, deliverables

Structural characterisation of aliphatic, non-hydrolyzable biopolymers in freshwater algae and a leaf cuticle by ruthenium tetroxide degradation

NARCIS (Netherlands)

Sinninghe Damsté, J.S.; Schouten, S.; Moerkerken, P.; Gelin, F.; Baas, M.; Leeuw, J.W. de

1998-01-01

Aliphatic, non-hydrolyzable biopolymers were subjected to RuO4-oxidation in order to examine the potential of this method in revealing details on their structures. The method was tested on model compounds first and found to cleave alkyl chains of aromatic moieties, double bonds and ether bonds.

Open-Source Electronic Health Record Systems for Low-Resource Settings: Systematic Review.

Science.gov (United States)

Syzdykova, Assel; Malta, André; Zolfo, Maria; Diro, Ermias; Oliveira, José Luis

2017-11-13

Despite the great impact of information and communication technologies on clinical practice and on the quality of health services, this trend has been almost exclusive to developed countries, whereas countries with poor resources suffer from many economic and social issues that have hindered the real benefits of electronic health (eHealth) tools. As a component of eHealth systems, electronic health records (EHRs) play a fundamental role in patient management and effective medical care services. Thus, the adoption of EHRs in regions with a lack of infrastructure, untrained staff, and ill-equipped health care providers is an important task. However, the main barrier to adopting EHR software in low- and middle-income countries is the cost of its purchase and maintenance, which highlights the open-source approach as a good solution for these underserved areas. The aim of this study was to conduct a systematic review of open-source EHR systems based on the requirements and limitations of low-resource settings. First, we reviewed existing literature on the comparison of available open-source solutions. In close collaboration with the University of Gondar Hospital, Ethiopia, we identified common limitations in poor resource environments and also the main requirements that EHRs should support. Then, we extensively evaluated the current open-source EHR solutions, discussing their strengths and weaknesses, and their appropriateness to fulfill a predefined set of features relevant for low-resource settings. The evaluation methodology allowed assessment of several key aspects of available solutions that are as follows: (1) integrated applications, (2) configurable reports, (3) custom reports, (4) custom forms, (5) interoperability, (6) coding systems, (7) authentication methods, (8) patient portal, (9) access control model, (10) cryptographic features, (11) flexible data model, (12) offline support, (13) native client, (14) Web client,(15) other clients, (16) code

Hemostatic, antibacterial biopolymers from Acacia arabica (Lam.) Willd. and Moringa oleifera (Lam.) as potential wound dressing materials.

Science.gov (United States)

Bhatnagar, Monica; Parwani, Laxmi; Sharma, Vinay; Ganguli, Jhuma; Bhatnagar, Ashish

2013-10-01

Acacia arabica and Moringa oleifera are credited with a number of medicinal properties. Traditionally gum of Acacia plant is used in the treatment of skin disorders to soothe skin rashes, soreness, inflammation and burns while Moringa seed extracts are known to have antibacterial activity. In the present study the potential of the polymeric component of aqueous extracts of gum acacia (GA) and the seeds of M. oleifera (MSP) in wound management was evaluated. The results revealed that both biopolymers were hemostatic and hasten blood coagulation. They showed shortening of activated partial thromboplastin time and prothrombin time and were non-cytotoxic in nature. Both showed antibacterial activity against organisms known to be involved in wound infections with MIC ranging from 500-600 microg mL(-1) for GA and 300-700 microg mL(-1) for MSP. They were biodegradable and exhibited water absorption capacity in the range of 415 to 935%. The hemostatic character coupled to these properties envisions their potential in preparation of dressings for bleeding and profusely exuding wounds. The biopolymers have been further analysed for their composition by Gas chromatography.

Biopolymer-based strategies in the design of smart medical devices and artificial organs.

Science.gov (United States)

Altomare, Lina; Bonetti, Lorenzo; Campiglio, Chiara E; De Nardo, Luigi; Draghi, Lorenza; Tana, Francesca; Farè, Silvia

2018-06-01

Advances in regenerative medicine and in modern biomedical therapies are fast evolving and set goals causing an upheaval in the field of materials science. This review discusses recent developments involving the use of biopolymers as smart materials, in terms of material properties and stimulus-responsive behavior, in the presence of environmental physico-chemical changes. An overview on the transformations that can be triggered in natural-based polymeric systems (sol-gel transition, polymer relaxation, cross-linking, and swelling) is presented, with specific focus on the benefits these materials can provide in biomedical applications.

Structural, mechanical and electrical properties biopolymer blend nanocomposites derived from poly (vinyl alcohol)/cashew gum/magnetite

Science.gov (United States)

Ramesan, M. T.; Jayakrishnan, P.; Manojkumar, T. K.; Mathew, G.

2018-01-01

Blending of poly vinyl alcohol (PVA) and natural biopolymers such as cashew gum (CG) with magnetite (Fe3O4) nanoparticles has been a promising way for preparing bio-degradable polymeric blend nanocomposites. PVA/CG/Fe3O4 blend nanocomposites have been prepared by a simple solution casting technique using water as the green solvent. The characterization of blend nanocomposites has been carried out by using Fourier transform infrared, UV, x-ray diffraction (XRD), high resolution transmission electron microscopy, scanning electron microscopy (SEM), differential scanning calorimetry, thermogravimetric analysis, mechanical properties and electrical conductivity. The interaction between nanoparticles and the blend segments was confirmed from the shift in characteristic absorption peaks of nanocomposites compared to PVA/CG blend. XRD analysis has shown the presence of crystalline peaks of nanoparticles in the blend matrix. The uniform distribution of Fe3O4 nanoparticles in the blend was revealed by TEM and SEM. The strong interaction of nanoparticles with the blend has been confirmed by the increase in glass transition temperature resulting from the reduced flexibility of the blend nanocomposite compared to that of the blend system. An increase in thermal stability and tensile strength and reduction in elongation at break of nanocomposites have been noticed with the increasing loading of nanoparticles. The AC electrical conductivity, dielectric constant and dielectric loss of the nanocomposites have been found to be higher than that of the blend. Generally, it can be stated that the magnetite nanoparticles acts as a potential filler in the PVA/CG blend at 7 wt% loading, giving the best balance of properties.

The development of a new process for gentle drying, micronisation and formulation of a high viscous biopoymer

OpenAIRE

Reibe, Christian

2011-01-01

Biopolymers are characterised by their biodegradable behaviour in certain environments. Especially the development of natural biopolymers from renewable resources is gathering increasing interest in the scientific as well as in the industrial sectors . Since Biopolymers may be tailored to specific requirements, the encapsulation of pharmaceutical compounds or flavours in biopolymers would open wide avenues for the production of controlled- release systems. Most common mechanical pulverisation...

Time domain NMR and conductivity study of apple pectin biopolymers

International Nuclear Information System (INIS)

Mattos, Ritamara I.; Souto, Sergio; Tambelli, Caio E.

2015-01-01

This communication presents results of "1H nuclear magnetic resonance of continuous distributions of spin-spin relaxation time (T_2) and A.C. conductivity of apple pectin biopolymers plasticized with glycerol and containing acetic acid. The continuous distributions reveals up to three components of spin-spin relaxation times (T_2). The two short T_2 components were associated with protons of pectin polymer chain and the longer T_2 can be attributed with the protons of the glycerol. The conductivity values increase with glycerol concentration with maximum at 7.9 x 10"-"4 S cm"-"1 for sample with 3.0 g of glycerol at 83 deg C. The behavior of activation energy and T_2 continuous distribution indicate an increase of proton mobility due the structural changes caused by glycerol addition. (author)

Evaluation of three electronic report processing systems for preparing hydrologic reports of the U.S Geological Survey, Water Resources Division

Science.gov (United States)

Stiltner, G.J.

1990-01-01

In 1987, the Water Resources Division of the U.S. Geological Survey undertook three pilot projects to evaluate electronic report processing systems as a means to improve the quality and timeliness of reports pertaining to water resources investigations. The three projects selected for study included the use of the following configuration of software and hardware: Ventura Publisher software on an IBM model AT personal computer, PageMaker software on a Macintosh computer, and FrameMaker software on a Sun Microsystems workstation. The following assessment criteria were to be addressed in the pilot studies: The combined use of text, tables, and graphics; analysis of time; ease of learning; compatibility with the existing minicomputer system; and technical limitations. It was considered essential that the camera-ready copy produced be in a format suitable for publication. Visual improvement alone was not a consideration. This report consolidates and summarizes the findings of the electronic report processing pilot projects. Text and table files originating on the existing minicomputer system were successfully transformed to the electronic report processing systems in American Standard Code for Information Interchange (ASCII) format. Graphics prepared using a proprietary graphics software package were transferred to all the electronic report processing software through the use of Computer Graphic Metafiles. Graphics from other sources were entered into the systems by scanning paper images. Comparative analysis of time needed to process text and tables by the electronic report processing systems and by conventional methods indicated that, although more time is invested in creating the original page composition for an electronically processed report , substantial time is saved in producing subsequent reports because the format can be stored and re-used by electronic means as a template. Because of the more compact page layouts, costs of printing the reports were 15% to 25

Solid-State (13)C NMR Delineates the Architectural Design of Biopolymers in Native and Genetically Altered Tomato Fruit Cuticles.

Science.gov (United States)

Chatterjee, Subhasish; Matas, Antonio J; Isaacson, Tal; Kehlet, Cindie; Rose, Jocelyn K C; Stark, Ruth E

2016-01-11

Plant cuticles on outer fruit and leaf surfaces are natural macromolecular composites of waxes and polyesters that ensure mechanical integrity and mitigate environmental challenges. They also provide renewable raw materials for cosmetics, packaging, and coatings. To delineate the structural framework and flexibility underlying the versatile functions of cutin biopolymers associated with polysaccharide-rich cell-wall matrices, solid-state NMR spectra and spin relaxation times were measured in a tomato fruit model system, including different developmental stages and surface phenotypes. The hydrophilic-hydrophobic balance of the cutin ensures compatibility with the underlying polysaccharide cell walls; the hydroxy fatty acid structures of outer epidermal cutin also support deposition of hydrophobic waxes and aromatic moieties while promoting the formation of cell-wall cross-links that rigidify and strengthen the cuticle composite during fruit development. Fruit cutin-deficient tomato mutants with compromised microbial resistance exhibit less efficient local and collective biopolymer motions, stiffening their cuticular surfaces and increasing their susceptibility to fracture.

Use and User Perception of Electronic Information Resources: A Case Study of Siva Institute of Frontier Technology, India

Directory of Open Access Journals (Sweden)

Velmurugan Chandran

2013-12-01

Full Text Available The present study aims to explore the use and user perception of electronic resources in Siva Institute of Frontier Technology, India. A total number of 123 users were taken into account for the study through a questionnaire-based survey method. A well-structured questionnaire was designed and distributed to the selected 200 students and staff members. 123 copies of the questionnaires were returned dully filled in and the overall response rate was 61.50 percent. The questionnaire contained both open- and close-ended questions. The collected data were classified, analyzed, and tabulated by using simple statistical methods. This study covers the impact of electronic resources on students and faculty in their academic pursuit.

Thermal Behavior of Tacca leontopetaloides Starch-Based Biopolymer

Directory of Open Access Journals (Sweden)

Nurul Shuhada Mohd Makhtar

2013-01-01

Full Text Available Starch is used whenever there is a need for natural elastic properties combined with low cost of production. However, the hydrophilic properties in structural starch will decrease the thermal performance of formulated starch polymer. Therefore, the effect of glycerol, palm olein, and crude palm oil (CPO, as plasticizers, on the thermal behavior of Tacca leontopetaloides starch incorporated with natural rubber in biopolymer production was investigated in this paper. Four different formulations were performed and represented by TPE1, TPE2, TPE3, and TPE4. The compositions were produced by using two-roll mill compounding. The sheets obtained were cut into small sizes prior to thermal testing. The addition of glycerol shows higher enthalpy of diffusion in which made the material easily can be degraded, leaving to an amount of 6.6% of residue. Blending of CPO with starch (TPE3 had a higher thermal resistance towards high temperature up to 310°C and the thermal behavior of TPE2 only gave a moderate performance compared with other TPEs.

A preliminary categorization of end-of-life electrical and electronic equipment as secondary metal resources

International Nuclear Information System (INIS)

Oguchi, Masahiro; Murakami, Shinsuke; Sakanakura, Hirofumi; Kida, Akiko; Kameya, Takashi

2011-01-01

Highlights: → End-of-life electrical and electronic equipment (EEE) as secondary metal resources. → The content and the total amount of metals in specific equipment are both important. → We categorized 21 EEE types from contents and total amounts of various metals. → Important equipment types as secondary resources were listed for each metal kind. → Collectability and possible collection systems of various EEE types were discussed. - Abstract: End-of-life electrical and electronic equipment (EEE) has recently received attention as a secondary source of metals. This study examined characteristics of end-of-life EEE as secondary metal resources to consider efficient collection and metal recovery systems according to the specific metals and types of EEE. We constructed an analogy between natural resource development and metal recovery from end-of-life EEE and found that metal content and total annual amount of metal contained in each type of end-of-life EEE should be considered in secondary resource development, as well as the collectability of the end-of-life products. We then categorized 21 EEE types into five groups and discussed their potential as secondary metal resources. Refrigerators, washing machines, air conditioners, and CRT TVs were evaluated as the most important sources of common metals, and personal computers, mobile phones, and video games were evaluated as the most important sources of precious metals. Several types of small digital equipment were also identified as important sources of precious metals; however, mid-size information and communication technology (ICT) equipment (e.g., printers and fax machines) and audio/video equipment were shown to be more important as a source of a variety of less common metals. The physical collectability of each type of EEE was roughly characterized by unit size and number of end-of-life products generated annually. Current collection systems in Japan were examined and potentially appropriate collection

Mechanical strength of ceramic scaffolds reinforced with biopolymers is comparable to that of human bone

DEFF Research Database (Denmark)

Henriksen, S S; Ding, M; Vinther Juhl, M

2011-01-01

Eight groups of calcium-phosphate scaffolds for bone implantation were prepared of which seven were reinforced with biopolymers, poly lactic acid (PLA) or hyaluronic acid in different concentrations in order to increase the mechanical strength, without significantly impairing the microarchitecture....... Controls were un-reinforced calcium-phosphate scaffolds. Microarchitectural properties were quantified using micro-CT scanning. Mechanical properties were evaluated by destructive compression testing. Results showed that adding 10 or 15% PLA to the scaffold significantly increased the mechanical strength...

Principles of formation of the content of an educational electronic resource on the basis of general and didactic patterns of learning

Directory of Open Access Journals (Sweden)

Ольга Юрьевна Заславская

2018-12-01

Full Text Available The article considers the influence of the development of technical means of teaching on the effectiveness of educational and methodical resources. Modern opportunities of information and communication technologies allow creating electronic educational resources that represent educational information that automates the learning process, provide information assistance, if necessary, collect and process statistical information on the degree of development of the content of the school material by schoolchildren, set an individual trajectory of learning, and so on. The main principle of data organization is the division of the training course into separate sections on the thematic elements and components of the learning process. General regularities include laws that encompass the entire didactic system, and in specific (particular cases, those whose actions extend to a separate component (aspect of the system. From the standpoint of the existence of three types of electronic training modules in the aggregate content of the electronic learning resource - information, control and module of practical classes - the principles of the formation of the electronic learning resource, in our opinion, should regulate all these components. Each of the certain principles is considered in the groups: scientific orientation, methodological orientation, systemic nature, accounting of interdisciplinary connections, fundamentalization, systematic and dosage sequence, rational use of study time, accessibility, minimization, operationalization of goals, unified identification diagnosis.

Rapid nano impact printing of silk biopolymer thin films

Science.gov (United States)

White, Robert D.; Gray, Caprice; Mandelup, Ethan; Amsden, Jason J.; Kaplan, David L.; Omenetto, Fiorenzo G.

2011-11-01

In this paper, nano impact printing of silk biopolymer films is described. An indenter is rapidly accelerated and transfers the nanopattern from a silicon master into the silk film during an impact event that occurs in less than 1 ms. Contact stresses of greater than 100 MPa can be achieved during the short impact period with low power and inexpensive hardware. Ring shaped features with a diameter of 2 µm and a ring width of 100-200 nm were successfully transferred into untreated silk films using this method at room temperature. Mechanical modeling was carried out to determine the contact stress distribution, and demonstrates that imprinting can occur for contact stresses of less than 2 MPa. Thermal characterization at the impact location shows that raising the temperature to 70 °C has only a limited effect on pattern transfer. Contact stresses of greater than approximately 100 MPa result in excessive deformation of the film and poor pattern transfer.

Rapid nano impact printing of silk biopolymer thin films

International Nuclear Information System (INIS)

White, Robert D; Gray, Caprice; Mandelup, Ethan; Amsden, Jason J; Kaplan, David L; Omenetto, Fiorenzo G

2011-01-01

In this paper, nano impact printing of silk biopolymer films is described. An indenter is rapidly accelerated and transfers the nanopattern from a silicon master into the silk film during an impact event that occurs in less than 1 ms. Contact stresses of greater than 100 MPa can be achieved during the short impact period with low power and inexpensive hardware. Ring shaped features with a diameter of 2 µm and a ring width of 100–200 nm were successfully transferred into untreated silk films using this method at room temperature. Mechanical modeling was carried out to determine the contact stress distribution, and demonstrates that imprinting can occur for contact stresses of less than 2 MPa. Thermal characterization at the impact location shows that raising the temperature to 70 °C has only a limited effect on pattern transfer. Contact stresses of greater than approximately 100 MPa result in excessive deformation of the film and poor pattern transfer.

Biopolymer nanostructures induced by plasma irradiation and metal sputtering

Energy Technology Data Exchange (ETDEWEB)

Slepička, P., E-mail: petr.slepicka@vscht.cz [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Juřík, P. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Malinský, P.; Macková, A. [Nuclear Physics Institute, Academy of Sciences of the Czech Republic, Rez, Prague 25068 (Czech Republic); Faculty of Science, J.E. Purkyně University, Ústí nad Labem (Czech Republic); Kasálková, N. Slepičková; Švorčík, V. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic)

2014-08-01

Modification based on polymer surface exposure to plasma treatment exhibits an easy and cheap technique for polymer surface nanostructuring. The influence of argon plasma treatment on biopolymer poly(L-lactide acid (PLLA) will be presented in this paper. The combination of Ar{sup +} ion irradiation, consequent sputter metallization (platinum) and thermal annealing of polymer surface will be summarized. The surface morphology was studied using atomic force microscopy. The Rutherford Backscattering Spectroscopy and X-ray Photoelectron Spectroscopy were used as analytical methods. The combination of plasma treatment with consequent thermal annealing and/or metal sputtering led to the change of surface morphology and its elemental ratio. The surface roughness and composition has been strongly influenced by the modification parameters and metal layer thickness. By plasma treatment of polymer surface combined with consequent annealing or metal deposition can be prepared materials applicable both in tissue engineering as cell carriers, but also in integrated circuit manufacturing.

From Millennium ERM to Proquest 360 Resource Manager: Implementing a new Electronic Resources Management System ERMS in an International Graduate Research University in Saudi Arabia

KAUST Repository

Ramli, Rindra M.

2017-05-17

An overview of the Recommendation Study and the subsequent Implementation of a new Electronic Resources Management system ERMS in an international graduate research university in the Kingdom of Saudi Arabia. It covers the timeline, deliverables and challenges as well as lessons learnt by the Project Team.

Conjugates of a Photoactivated Rhodamine with Biopolymers for Cell Staining

Science.gov (United States)

Zaitsev, Sergei Yu.; Shaposhnikov, Mikhail N.; Solovyeva, Daria O.; Solovyeva, Valeria V.; Rizvanov, Albert A.

2014-01-01

Conjugates of the photoactivated rhodamine dyes with biopolymers (proteins, polysaccharides, and nucleic acids) are important tools for microscopic investigation of biological tissue. In this study, a precursor of the photoactivated fluorescent dye (PFD) has been successfully used for staining of numerous mammalian cells lines and for conjugate formation with chitosan (“Chitosan-PFD”) and histone H1 (“Histone H1.3-PFD”). The intensive fluorescence has been observed after photoactivation of these conjugates inside cells (A431, HaCaT, HEK239, HBL-100, and MDCK). Developed procedures and obtained data are important for further application of novel precursors of fluorescent dyes (“caged” dyes) for microscopic probing of biological objects. Thus, the synthesized “Chitosan-PFD” and “Histone H1-PFD” have been successfully applied in this study for intracellular transport visualization by fluorescent microscopy. PMID:25383365

Biopolymer-based thermoplastic mixture for producing solid biodegradable shaped bodies and its photo degradation stability

Science.gov (United States)

Sulong, Nurulsaidatulsyida; Rus, Anika Zafiah M.

2013-12-01

In recent years, biopolymers with controllable lifetimes have become increasingly important for many applications in the areas of agriculture, biomedical implants and drug release, forestry, wild life conservation and waste management. Natural oils are considered to be the most important class of renewable sources. They can be obtained from naturally occurring plants, such as sunflower, cotton, linseed and palm oil. In Malaysia, palm oil is an inexpensive and commodity material. Biopolymer produced from palm oil (Bio-VOP) is a naturally occurring biodegradable polymer and readily available from agriculture. For packaging use however, Bio-VOP is not thermoplastic and its granular form is unsuitable for most uses in the plastics industry, mainly due to processing difficulties during extrusion or injection moulding. Thus, research workers have developed several methods to blend Bio-VOP appropriately for industrial uses. In particular, injections moulding processes, graft copolymerisation, and preparation of blends with thermoplastic polymers have been studied to produce solid biodegradable shaped bodies. HDPE was chosen as commercial thermoplastic materials and was added with 10% Bio-VOP for the preparation of solid biodegradable shaped bodies named as HD-VOP. The UV light exposure of HD-VOP at 12 minutes upon gives the highest strength of this material that is 17.6 MPa. The morphological structure of HD-VOP shows dwi structure surface fracture which is brittle and ductile properties.

The Synthesis of the Hierarchical Structure of Information Resources for Management of Electronic Commerce Entities

Directory of Open Access Journals (Sweden)

Krutova Anzhelika S.

2017-06-01

Full Text Available The aim of the article is to develop the theoretical bases for the classification and coding of economic information and the scientific justification of the content of information resources of an electronic commerce enterprise. The essence of information resources for management of electronic business entities is investigated. It is proved that the organization of accounting in e-commerce systems is advisable to be built on the basis of two circuits: accounting for financial flows and accounting associated with transformation of business factors in products and services as a result of production activities. There presented a sequence of accounting organization that allows to combine the both circuits in a single information system, which provides a possibility for the integrated replenishment and distributed simultaneous use of the e-commerce system by all groups of users. It is proved that the guarantee of efficient activity of the information management system of electronic commerce entities is a proper systematization of the aggregate of information resources on economic facts and operations of an enterprise in accordance with the management tasks by building the hierarchy of accounting nomenclatures. It is suggested to understand nomenclature as an objective, primary information aggregate concerning a certain fact of the economic activity of an enterprise, which is characterized by minimum requisites, is entered into the database of the information system and is to be reflected in the accounting system. It is proposed to build a database of e-commerce systems as a part of directories (constants, personnel, goods / products, suppliers, buyers and the hierarchy of accounting nomenclatures. The package of documents regulating the organization of accounting at an enterprise should include: the provision on the accounting services, the order on the accounting policy, the job descriptions, the schedules of information exchange, the report card and

Neutron scattering studies of the dynamics of biopolymer-water systems using pulsed-source spectrometers

Energy Technology Data Exchange (ETDEWEB)

Middendorf, H.D. [Univ. of Oxford (United Kingdom); Miller, A. [Stirling Univ., Stirling (United Kingdom)

1994-12-31

Energy-resolving neutron scattering techniques provide spatiotemporal data suitable for testing and refining analytical models or computer simulations of a variety of dynamical processes in biomolecular systems. This paper reviews experimental work on hydrated biopolymers at ISIS, the UK Pulsed Neutron Facility. Following an outline of basic concepts and a summary of the new instrumental capabilities, the progress made is illustrated by results from recent experiments in two areas: quasi- elastic scattering from highly hydrated polysaccharide gels (agarose and hyaluronate), and inelastic scattering from vibrational modes of slightly hydrated collagen fibers.

Neutron scattering studies of the dynamics of biopolymer-water systems using pulsed-source spectrometers

International Nuclear Information System (INIS)

Middendorf, H.D.; Miller, A.

1994-01-01

Energy-resolving neutron scattering techniques provide spatiotemporal data suitable for testing and refining analytical models or computer simulations of a variety of dynamical processes in biomolecular systems. This paper reviews experimental work on hydrated biopolymers at ISIS, the UK Pulsed Neutron Facility. Following an outline of basic concepts and a summary of the new instrumental capabilities, the progress made is illustrated by results from recent experiments in two areas: quasi- elastic scattering from highly hydrated polysaccharide gels (agarose and hyaluronate), and inelastic scattering from vibrational modes of slightly hydrated collagen fibers

Chemical characterization of Xanthan biopolymers synthesized by Xanthomonas campestris pv pruni strains

International Nuclear Information System (INIS)

Moreira, Angelita da S.; Vendruscolo, Claire T.; Furlan, Ligia; Galland, Griselda

2001-01-01

In this work we describe the characterisation of Xanthan biopolymers synthesized by two Xanthomonas campestris pv pruni strains, in aerobic fermentation. By chromatography on TLC we could notice the presence of Mannose monomer in higher proportion in the 82 strain with relation to the another ones. The viscosity results showed the temperature dependence. The 06 and 82 strains had their viscosity increased whereas for the 87 strain we could observe a reduction with temperature increasing. The 13 C NMR spectrum of 87 strain showed the characteristic signals at approximately 92.8, 70.4 and 61.4 ppm, attributed to C1, C4 and C6 from glucose monomer, with higher intensity. (author)

Controlling user access to electronic resources without password

Science.gov (United States)

Smith, Fred Hewitt

2015-06-16

Described herein are devices and techniques for remotely controlling user access to a restricted computer resource. The process includes pre-determining an association of the restricted computer resource and computer-resource-proximal environmental information. Indicia of user-proximal environmental information are received from a user requesting access to the restricted computer resource. Received indicia of user-proximal environmental information are compared to associated computer-resource-proximal environmental information. User access to the restricted computer resource is selectively granted responsive to a favorable comparison in which the user-proximal environmental information is sufficiently similar to the computer-resource proximal environmental information. In at least some embodiments, the process further includes comparing user-supplied biometric measure and comparing it with a predetermined association of at least one biometric measure of an authorized user. Access to the restricted computer resource is granted in response to a favorable comparison.

Electronic theses and dissertations: a review of this valuable resource for nurse scholars worldwide.

Science.gov (United States)

Goodfellow, L M

2009-06-01

A worldwide repository of electronic theses and dissertations (ETDs) could provide worldwide access to the most up-to-date research generated by masters and doctoral students. Until that international repository is established, it is possible to access some of these valuable knowledge resources. ETDs provide a technologically advanced medium with endless multimedia capabilities that far exceed the print and bound copies of theses and dissertations housed traditionally in individual university libraries. CURRENT USE: A growing trend exists for universities worldwide to require graduate students to submit theses or dissertations as electronic documents. However, nurse scholars underutilize ETDs, as evidenced by perusing bibliographic citation lists in many of the research journals. ETDs can be searched for and retrieved through several digital resources such as the Networked Digital Library of Theses and Dissertations (http://www.ndltd.org), ProQuest Dissertations and Theses (http://www.umi.com), the Australasian Digital Theses Program (http://adt.caul.edu.au/) and through individual university web sites and online catalogues. An international repository of ETDs benefits the community of nurse scholars in many ways. The ability to access recent graduate students' research electronically from anywhere in the world is advantageous. For scholars residing in developing countries, access to these ETDs may prove to be even more valuable. In some cases, ETDs are not available for worldwide access and can only be accessed through the university library from which the student graduated. Public access to university library ETD collections is not always permitted. Nurse scholars from both developing and developed countries could benefit from ETDs.

Library resources on the Internet

Science.gov (United States)

Buchanan, Nancy L.

1995-07-01

Library resources are prevalent on the Internet. Library catalogs, electronic books, electronic periodicals, periodical indexes, reference sources, and U.S. Government documents are available by telnet, Gopher, World Wide Web, and FTP. Comparatively few copyrighted library resources are available freely on the Internet. Internet implementations of library resources can add useful features, such as full-text searching. There are discussion lists, Gophers, and World Wide Web pages to help users keep up with new resources and changes to existing ones. The future will bring more library resources, more types of library resources, and more integrated implementations of such resources to the Internet.

ELECTRONIC EDUCATIONAL RESOURCES FOR ONLINE SUPPORT OF MODERN CHEMISTRY CLASSES IN SPECIALIZED SCHOOL

Directory of Open Access Journals (Sweden)

Maria D. Tukalo

2013-09-01

Full Text Available This article contains material of some modern electronic educational resources that can be used via the Internet to support the modern chemistry classes in specialized school. It was drawn attention to the educational chemical experiments as means of knowledge; simulated key motivational characteristics to enhance students interest for learning subjects, their cognitive and practical activity in the formation of self-reliance and self-creative; commented forecasts for creating of conditions to enhance the creative potential of students in a modern learning environment.

Selection and Evaluation of Electronic Resources

Directory of Open Access Journals (Sweden)

Doğan Atılgan

2013-11-01

Full Text Available Publication boom and issues related to controlling and accession of printed sources have created some problems after World War II. Consequently, publishing industry has encountered the problem of finding possible solution for emerged situation. Industry of electronic publishing has started to improve with the rapid increase of the price of printed sources as well as the problem of publication boom. The first effects of electronic publishing were appeared on the academic and scholarly publications then electronic publishing became a crucial part of all types of publications. As a result of these developments, collection developments and service policies of information centers were also significantly changed. In this article, after a general introduction about selection and evaluation processes of electronic publications, the subscribed databases by a state and a privately owned university in Turkey and their usage were examined.

An Exploratory study on the use of LibAnswers to Resolve, Track and Monitor Electronic Resources Issues: The KAUST Library experience

KAUST Repository

Ramli, Rindra M.

2017-01-01

An Exploratory study on KAUST library use of LibAnswers in resolving electronic resources questions received in LibAnswers. It describes the findings of the questions received in LibAnswers. The author made suggestions based on the findings to improve the reference services in responding to e-resources questions.

An Exploratory study on the use of LibAnswers to Resolve, Track and Monitor Electronic Resources Issues: The KAUST Library experience

KAUST Repository

Ramli, Rindra M.

2017-05-03

An Exploratory study on KAUST library use of LibAnswers in resolving electronic resources questions received in LibAnswers. It describes the findings of the questions received in LibAnswers. The author made suggestions based on the findings to improve the reference services in responding to e-resources questions.

The level of the usage of the human resource information system and electronic recruitment in Croatian companies

Directory of Open Access Journals (Sweden)

Snježana Pivac

2014-12-01

Full Text Available Performing business according to contemporary requirements influences companies for continuous usage of modern managerial tools, such as a human resource information system (HRIS and electronic recruitment (ER. Human resources have been recognised as curtail resources and the main source of a competitive advantage in creation of successful business performance. In order to attract and select the top employees, companies use quality information software for attracting internal ones, and electronic recruitment for attracting the best possible external candidates. The main aim of this paper is to research the level of the usage of HRIS and ER within medium-size and large Croatian companies. Moreover, the additional aim of this paper is to evaluate the relationship among the usage of these modern managerial tools and the overall success of human resource management within these companies. For the purpose of this paper, primary and secondary research has been conducted in order to reveal the level of the usage of HRIS and ER as well as the overall success of human resource management in Croatian companies. The companies’ classification (HRIS and ER is done by using the non-hierarchical k-means cluster method as well as the nonparametric Kruskal Wallis test. Further, the companies are ranked by the multicriteria PROMETHEE method. Relevant nonparametric tests are used for testing the overall companies’ HRM. Finally, binary logistic regression is estimated, relating binary variable HRM and HRIS development. After detailed research, it can be concluded that large Croatian companies apply HRIS in majority (with a positive relation to HRM performance, but still require certain degrees of its development.

The electronic encapsulation of knowledge in hydraulics, hydrology and water resources

Science.gov (United States)

Abbott, Michael B.

The rapidly developing practice of encapsulating knowledge in electronic media is shown to lead necessarily to the restructuring of the knowledge itself. The consequences of this for hydraulics, hydrology and more general water-resources management are investigated in particular relation to current process-simulation, real-time control and advice-serving systems. The generic properties of the electronic knowledge encapsulator are described, and attention is drawn to the manner in which knowledge 'goes into hiding' through encapsulation. This property is traced in the simple situations of pure mathesis and in the more complex situations of taxinomia using one example each from hydraulics and hydrology. The consequences for systems architectures are explained, pointing to the need for multi-agent architectures for ecological modelling and for more general hydroinformatics systems also. The relevance of these developments is indicated by reference to ongoing projects in which they are currently being realised. In conclusion, some more general epistemological aspects are considered within the same context. As this contribution is so much concerned with the processes of signification and communication, it has been partly shaped by the theory of semiotics, as popularised by Eco ( A Theory of Semiotics, Indiana University, Bloomington, 1977).

RESEARCH OF INFLUENCE OF QUALITY OF ELECTRONIC EDUCATIONAL RESOURCES ON QUALITY OF TRAINING WITH USE OF DISTANCE TECHNOLOGIES

Directory of Open Access Journals (Sweden)

H. M. Kravtsov

2013-03-01

Full Text Available Communication improving of educational processes requires today new approaches to the management arrangements and forming of educational policy in the field of distance learning, which is based on the use of modern information and communication technologies. An important step in this process is the continuous monitoring of the development and implementation of information technology and, in particular, the distance learning systems in higher educational establishments. The main objective of the monitoring is the impact assessment on the development of distance learning following the state educational standards, curricula, methodical and technical equipment and other factors; factors revelation that influence the implementation and outcomes of distance learning; results comparison of educational institution functioning and distance education systems in order to determine the most efficient ways of its development. The paper presents the analysis results of the dependence of the quality of educational services on the electronic educational resources. Trends in educational services development was studied by comparing the quality influence of electronic educational resources on the quality of educational services of higher pedagogical educational institutions of Ukraine as of 2009-2010 and 2012-2013. Generally, the analysis of the survey results allows evaluating quality of the modern education services as satisfactory and it can be said that almost 70% of the success of their future development depends on the quality of the used electronic educational resources and distance learning systems in particular.

Environment-friendly cathodes using biopolymer chitosan with enhanced electrochemical behavior for use in lithium ion batteries.

Science.gov (United States)

Prasanna, K; Subburaj, T; Jo, Yong Nam; Lee, Won Jong; Lee, Chang Woo

2015-04-22

The biopolymer chitosan has been investigated as a potential binder for the fabrication of LiFePO4 cathode electrodes in lithium ion batteries. Chitosan is compared to the conventional binder, polyvinylidene fluoride (PVDF). Dispersion of the active material, LiFePO4, and conductive agent, Super P carbon black, is tested using a viscosity analysis. The enhanced structural and morphological properties of chitosan are compared to the PVDF binder using X-ray diffraction analysis (XRD) and field emission scanning electron microscopy (FE-SEM). Using an electrochemical impedance spectroscopy (EIS) analysis, the LiFePO4 electrode with the chitosan binder is observed to have a high ionic conductivity and a smaller increase in charge transfer resistance based on time compared to the LiFePO4 electrode with the PVDF binder. The electrode with the chitosan binder also attains a higher discharge capacity of 159.4 mAh g(-1) with an excellent capacity retention ratio of 98.38% compared to the electrode with the PVDF binder, which had a discharge capacity of 127.9 mAh g(-1) and a capacity retention ratio of 85.13%. Further, the cycling behavior of the chitosan-based electrode is supported by scrutinizing its charge-discharge behavior at specified intervals and by a plot of dQ/dV.

Complex electrical monitoring of biopolymer and iron mineral precipitation for microbial enhanced hydrocarbon recovery

Science.gov (United States)

Wu, Y.; Hubbard, C. G.; Dong, W.; Hubbard, S. S.

2011-12-01

Microbially enhanced hydrocarbon recovery (MEHR) mechanisms are expected to be impacted by processes and properties that occur over a wide range of scales, ranging from surface interactions and microbial metabolism at the submicron scale to changes in wettability and pore geometry at the pore scale to geological heterogeneities at the petroleum reservoir scale. To eventually ensure successful, production-scale implementation of laboratory-developed MEHR procedures under field conditions, it is necessary to develop approaches that can remotely monitor and accurately predict the complex microbially-facilitated transformations that are expected to occur during MEHR treatments in reservoirs (such as the evolution of redox profiles, oil viscosity or matrix porosity/permeability modifications). Our initial studies are focused on laboratory experiments to assess the geophysical signatures of MEHR-induced biogeochemical transformations, with an ultimate goal of using these approaches to monitor field treatments. Here, we explore the electrical signatures of two MEHR processes that are designed to produce end-products that will plug high permeability zones in reservoirs and thus enhance sweep efficiency. The MEHR experiments to induce biopolymers (in this case dextran) and iron mineral precipitates were conducted using flow-through columns. Leuconostoc mesenteroides, a facultative anaerobe, known to produce dextran from sucrose was used in the biopolymer experiments. Paused injection of sucrose, following inoculation and initial microbial attachment, was carried out on daily basis, allowing enough time for dextran production to occur based on batch experiment observations. Electrical data were collected on daily basis and fluid samples were extracted from the column for characterization. Changes in electrical signal were not observed during initial microbial inoculation. Increase of electrical resistivity and decrease of electrical phase response were observed during the

Tracking the Flow of Resources in Electronic Waste - The Case of End-of-Life Computer Hard Disk Drives.

Science.gov (United States)

Habib, Komal; Parajuly, Keshav; Wenzel, Henrik

2015-10-20

Recovery of resources, in particular, metals, from waste flows is widely seen as a prioritized option to reduce their potential supply constraints in the future. The current waste electrical and electronic equipment (WEEE) treatment system is more focused on bulk metals, where the recycling rate of specialty metals, such as rare earths, is negligible compared to their increasing use in modern products, such as electronics. This study investigates the challenges in recovering these resources in the existing WEEE treatment system. It is illustrated by following the material flows of resources in a conventional WEEE treatment plant in Denmark. Computer hard disk drives (HDDs) containing neodymium-iron-boron (NdFeB) magnets were selected as the case product for this experiment. The resulting output fractions were tracked until their final treatment in order to estimate the recovery potential of rare earth elements (REEs) and other resources contained in HDDs. The results further show that out of the 244 kg of HDDs treated, 212 kg comprising mainly of aluminum and steel can be finally recovered from the metallurgic process. The results further demonstrate the complete loss of REEs in the existing shredding-based WEEE treatment processes. Dismantling and separate processing of NdFeB magnets from their end-use products can be a more preferred option over shredding. However, it remains a technological and logistic challenge for the existing system.

Ant-cave structured MnCO3/Mn3O4 microcubes by biopolymer-assisted facile synthesis for high-performance pseudocapacitors

Science.gov (United States)

Chandra Sekhar, S.; Nagaraju, Goli; Yu, Jae Su

2018-03-01

Porous and ant-cave structured MnCO3/Mn3O4 microcubes (MCs) were facilely synthesized via a biopolymer-assisted hydrothermal approach. Herein, chitosan was used as a natural biopolymer, which greatly controls the surface morphology and size of the prepared composite. The amino and hydroxyl group-functionalized chitosan engraves the outer surface of MCs during the hydrothermal process, which designs the interesting morphology of nanopath ways on the surface of MCs. When used as an electrode material for pseudocapacitors, the ant-cave structured MnCO3/Mn3O4 MCs showed superior energy storage values compared to the material prepared without chitosan in aqueous electrolyte solution. Precisely, the prepared ant-cave structured MnCO3/Mn3O4 MCs exhibited a maximum specific capacitance of 116.2 F/g at a current density of 0.7 A/g with an excellent cycling stability of 73.86% after 2000 cycles. Such facile and low-cost synthesis of pseudocapacitive materials with porous nanopaths is favorable for the fabrication of high-performance energy storage devices.

The role of printing parameters and scaffold biopolymer properties in the efficacy of a new hybrid nano-bioprinting system

Energy Technology Data Exchange (ETDEWEB)

Buyukhatipoglu, Kivilcim; Jo, Wonjin; Sun Wei; Clyne, Alisa Morss, E-mail: asm67@drexel.ed [Mechanical Engineering and Mechanics, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States)

2009-09-15

We created a hybrid nano-bioprinting system, which combines the initial patterning capabilities of direct cell writing with the active patterning capabilities of superparamagnetic nanoparticles. Biofabrication conditions, including printing parameters and scaffold biopolymer properties, may affect cell viability, nanoparticle manipulation and patterning capabilities. Nanoparticles were printed under varied conditions either in the biopolymer or loaded inside cells. Cell viability, alginate viscosity, nanoparticle movement and printing resolution were measured. We now show that while nanoparticles decreased cell viability, nozzle size had no significant effect. High printing pressure decreased cell viability, but viability loss was not accentuated by nanoparticles. High nanoparticle concentrations increased alginate viscosity at higher alginate concentrations. Nanoparticle velocity in response to a magnetic field was a function of nanoparticle diameter and scaffold viscosity, which agreed with a mathematical model of nanoparticle movement. Finally, the nano-bioprinting system resolution and patterning precision were not affected by nanoparticles in the prepolymer solution. These data suggest that nanoparticle incorporation in solid freeform fabrication does not change biofabrication parameters unless high nanoparticle concentrations are used. Future work includes developing vascularized tissue engineering constructs using the nano-bioprinting system.

The role of printing parameters and scaffold biopolymer properties in the efficacy of a new hybrid nano-bioprinting system

International Nuclear Information System (INIS)

Buyukhatipoglu, Kivilcim; Jo, Wonjin; Sun Wei; Clyne, Alisa Morss

2009-01-01

We created a hybrid nano-bioprinting system, which combines the initial patterning capabilities of direct cell writing with the active patterning capabilities of superparamagnetic nanoparticles. Biofabrication conditions, including printing parameters and scaffold biopolymer properties, may affect cell viability, nanoparticle manipulation and patterning capabilities. Nanoparticles were printed under varied conditions either in the biopolymer or loaded inside cells. Cell viability, alginate viscosity, nanoparticle movement and printing resolution were measured. We now show that while nanoparticles decreased cell viability, nozzle size had no significant effect. High printing pressure decreased cell viability, but viability loss was not accentuated by nanoparticles. High nanoparticle concentrations increased alginate viscosity at higher alginate concentrations. Nanoparticle velocity in response to a magnetic field was a function of nanoparticle diameter and scaffold viscosity, which agreed with a mathematical model of nanoparticle movement. Finally, the nano-bioprinting system resolution and patterning precision were not affected by nanoparticles in the prepolymer solution. These data suggest that nanoparticle incorporation in solid freeform fabrication does not change biofabrication parameters unless high nanoparticle concentrations are used. Future work includes developing vascularized tissue engineering constructs using the nano-bioprinting system.

Resource Recovery from Wastewater by Biological Technologies: Opportunities, Challenges, and Prospects

Science.gov (United States)

Puyol, Daniel; Batstone, Damien J.; Hülsen, Tim; Astals, Sergi; Peces, Miriam; Krömer, Jens O.

2017-01-01

Limits in resource availability are driving a change in current societal production systems, changing the focus from residues treatment, such as wastewater treatment, toward resource recovery. Biotechnological processes offer an economic and versatile way to concentrate and transform resources from waste/wastewater into valuable products, which is a prerequisite for the technological development of a cradle-to-cradle bio-based economy. This review identifies emerging technologies that enable resource recovery across the wastewater treatment cycle. As such, bioenergy in the form of biohydrogen (by photo and dark fermentation processes) and biogas (during anaerobic digestion processes) have been classic targets, whereby, direct transformation of lipidic biomass into biodiesel also gained attention. This concept is similar to previous biofuel concepts, but more sustainable, as third generation biofuels and other resources can be produced from waste biomass. The production of high value biopolymers (e.g., for bioplastics manufacturing) from organic acids, hydrogen, and methane is another option for carbon recovery. The recovery of carbon and nutrients can be achieved by organic fertilizer production, or single cell protein generation (depending on the source) which may be utilized as feed, feed additives, next generation fertilizers, or even as probiotics. Additionlly, chemical oxidation-reduction and bioelectrochemical systems can recover inorganics or synthesize organic products beyond the natural microbial metabolism. Anticipating the next generation of wastewater treatment plants driven by biological recovery technologies, this review is focused on the generation and re-synthesis of energetic resources and key resources to be recycled as raw materials in a cradle-to-cradle economy concept. PMID:28111567

Ranitidine Loaded Biopolymer Floats: Designing, Characterization, and Evaluation

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Abdul Karim

2017-01-01

Full Text Available The float formulation is a strategy to improve the bioavailability of drugs by gastroretentive drug delivery system (GRDDS. A drug delivery model based on swellable and reswellable low density biopolymers has been designed to evaluate its drug release profile using ranitidine (RNT as a model drug and formulations have been prepared utilizing 32 factorial designs. The drug release (DR data has been subjected to various kinetic models to investigate the DR mechanism. A reduction in rate has been observed by expanding the amounts of PSG and LSG parts, while an expansion has been noted by increasing the concentration of tragacanth (TG and citric acid (CA with an increment in floating time. The stearic acid (SA has been used to decrease the lag time because a decrease in density of system was observed. The kinetic analysis showed that the optimized formulation (S4F3 followed zero-order kinetics and power law was found to be best fitted due to its minimum lag time and maximum floating ability. The resemblance of observed and predicted values indicated the validity of derived equations for evaluating the effect of independent variables while kinetic study demonstrated that the applied models are feasible for evaluating and developing float for RNT.

Study of the ionic conduction mechanism based on carboxymethyl cellulose biopolymer electrolytes

Energy Technology Data Exchange (ETDEWEB)

Samsudin, A. S.; Isa, M. I. N. [Universiti Malaysia Terengganu, Terengganu (Mali)

2014-11-15

Biodegradable carboxymethyl cellulose (CMC) doped with various compositions of NH{sub 4}Br biopolymer electrolytes (BE) were successfully prepared via a solution-cast technique. The ionic conductivity for the CMC-NH{sub 4}Br BE system was measured by using impedance spectroscopy, and the highest ambient temperature conductivity was observed to be 1.12 x 10{sup -4} S cm{sup -1} for the sample containing 25-wt.% NH{sub 4}Br. The temperature dependence of the ionic conductivity revealed that the BE system followed an Arrhenius behavior. Jonscher's universal power law was applied to analyze the AC conductivity of the highest conducting sample in the BE system, and the results indicate that the conduction is due to small polaron hopping (SPH) caused by a non-adiabatic mechanism.

Modulating structural hierarchies of manganese oxide in morphology and porosity by marine biopolymer for improved supercapacitors

International Nuclear Information System (INIS)

Zong, Lu; Wu, Xiaochen; You, Jun; Li, Mingjie; Li, Chaoxu

2016-01-01

Nanostructured MnO 2 is one of the most promising electrode materials for supercapacitors (SCs) on account of its exceptional properties including high theoretical capacitance, natural abundance, environmental safety and low cost. However its merits cannot be fully embodied by its current synthesis approaches, since most of them were normally tedious, costly, low yield or environment unfriendly, and poor in controlling multiple parameters of MnO 2 . Inspired by biopolymer-assisted synthesis of hierarchical inorganic materials in living systems, a marine biopolymer was used for structure-controllable synthesis of MnO 2 in this study. Functioning as the reductant, surfactant and directing agent, alginate could tune the hierarchical architecture of MnO 2 in multiple parameters including the dimension, nanometric size, crystallographic form and porosity, where δ-MnO 2 nanocrystals with the size of 5 ∼ 10 nm first assembled into nanosheets, and then flower-like structure with particle size tunable within 40 ∼ 200 nm as well as micro- and mesopores. Due to these unique hierarchies in both the morphology and porosity, as-prepared MnO 2 exhibited excellent performance as SC electrode, e.g. high power density (32.5 kW kg −1 ), high energy density (75.1 Wh kg −1 ) and great cycling stability. Given the green, low-temperature and scalable one-step process, this synthesis may pave a highly promising way to massive production of MnO 2 electrode materials for SCs.

Effect of Some Biopolymers on the Rheological Behavior of Surimi Gel

Directory of Open Access Journals (Sweden)

Takahiro Noda

2012-05-01

Full Text Available The objective of this study was to investigate the effect of selected biopolymers on the rheological properties of surimi. In our paper, we highlight the functional properties and rheological aspects of some starch mixtures used in surimi. However, the influence of some other ingredients, such as cryoprotectants, mannans, and hydroxylpropylmethylcellulose (HPMC, on the rheological properties of surimi is also described. The outcome reveals that storage modulus increased with the addition of higher levels of starch. Moreover, the increasing starch level increased the breaking force, deformation, and gel strength of surimi as a result of the absorption of water by starch granules in the mixture to make the surimi more rigid. On the other hand, the addition of cryoprotectants, mannans, and HPMC improved the rheological properties of surimi. The data obtained in this paper could be beneficial particularly to the scientists who deal with food processing field.

Hindrances to precise recovery of cellular forces in fibrous biopolymer networks

Science.gov (United States)

Zhang, Yunsong; Feng, Jingchen; Heizler, Shay I.; Levine, Herbert

2018-03-01

How cells move through the three-dimensional extracellular matrix (ECM) is of increasing interest in attempts to understand important biological processes such as cancer metastasis. Just as in motion on flat surfaces, it is expected that experimental measurements of cell-generated forces will provide valuable information for uncovering the mechanisms of cell migration. However, the recovery of forces in fibrous biopolymer networks may suffer from large errors. Here, within the framework of lattice-based models, we explore possible issues in force recovery by solving the inverse problem: how can one determine the forces cells exert to their surroundings from the deformation of the ECM? Our results indicate that irregular cell traction patterns, the uncertainty of local fiber stiffness, the non-affine nature of ECM deformations and inadequate knowledge of network topology will all prevent the precise force determination. At the end, we discuss possible ways of overcoming these difficulties.

Understanding release kinetics of biopolymer drug delivery microcapsules for biomedical applications

International Nuclear Information System (INIS)

Desai, Salil; Perkins, Jessica; Harrison, Benjamin S.; Sankar, Jag

2010-01-01

Drug delivery and dosage concentrations are considered as major focal points in conventional as well as battlefield emergency medicine. The concept of localizing drug delivery via microcapsules is an evolving field to confine the adverse side effects of high concentration drug doses. This paper focuses on understanding release kinetics through biopolymer microcapsules for time-dependent drug release. Calcium alginate microcapsules were manufactured using a direct-write inkjet technique. Rhodamine 6G was used as the release agent to observe the release kinetics from calcium alginate beads in distilled water. A design of experiments was constructed to compare the effect of the microcapsule diameter and different concentrations of calcium chloride (M) and sodium alginate (%, w/v) solutions on the release kinetics profiles of the microcapsules. This research gives insight to identify favorable sizes of microcapsules and concentrations of sodium alginate and calcium chloride solutions for controlled release behavior of drug delivery microcapsules.

New Guar Biopolymer Silver Nanocomposites for Wound Healing Applications

Directory of Open Access Journals (Sweden)

Runa Ghosh Auddy

2013-01-01

Full Text Available Wound healing is an innate physiological response that helps restore cellular and anatomic continuity of a tissue. Selective biodegradable and biocompatible polymer materials have provided useful scaffolds for wound healing and assisted cellular messaging. In the present study, guar gum, a polymeric galactomannan, was intrinsically modified to a new cationic biopolymer guar gum alkylamine (GGAA for wound healing applications. Biologically synthesized silver nanoparticles (Agnp were further impregnated in GGAA for extended evaluations in punch wound models in rodents. SEM studies showed silver nanoparticles well dispersed in the new guar matrix with a particle size of ~18 nm. In wound healing experiments, faster healing and improved cosmetic appearance were observed in the new nanobiomaterial treated group compared to commercially available silver alginate cream. The total protein, DNA, and hydroxyproline contents of the wound tissues were also significantly higher in the treated group as compared with the silver alginate cream (P<0.05. Silver nanoparticles exerted positive effects because of their antimicrobial properties. The nanobiomaterial was observed to promote wound closure by inducing proliferation and migration of the keratinocytes at the wound site. The derivatized guar gum matrix additionally provided a hydrated surface necessary for cell proliferation.

Using mobile electronic devices to deliver educational resources in developing countries.

Science.gov (United States)

Mazal, Jonathan Robert; Ludwig, Rebecca

2015-01-01

Developing countries have far fewer trained radiography professionals than developed countries, which exacerbates the limited access to imaging services. The lack of trained radiographers reflects, in part, limited availability of radiographer-specific educational resources. Historically, organizations that provided such resources in the developing world faced challenges related to the limited stock of current materials as well as expenses associated with shipping and delivery. Four mobile electronic devices (MEDs) were loaded with educational content (e-books, PDFs, and digital applications) spanning major radiography topics. The MEDs were distributed to 4 imaging departments in Ghana, India, Nepal, and Nigeria based on evidence of need for radiography-specific resources, as revealed by survey responses. A cost comparison of postal delivery vs digital delivery of educational content was performed. The effectiveness of delivering additional content via Wi-Fi transmission also was evaluated. Feedback was solicited on users' experience with the MEDs as a delivery tool for educational content. An initial average per e-book expense of $30.05, which included the cost of the device, was calculated for the MED delivery method compared with $15.56 for postal delivery of printed materials. The cost of the MED delivery method was reduced to an average of $10.05 for subsequent e-book deliveries. Additional content was successfully delivered via Wi-Fi transmission to all recipients during the 3-month follow-up period. Overall user feedback on the experience was positive, and ideas for enhancing the MED-based method were identified. Using MEDs to deliver radiography-specific educational content appears to be more cost effective than postal delivery of printed materials on a long-term basis. MEDs are more efficient for providing updates to educational materials. Customization of content to department needs, and using projector devices could enhance the usefulness of MEDs for

Success criteria for electronic medical record implementations in low-resource settings: a systematic review.

Science.gov (United States)

Fritz, Fleur; Tilahun, Binyam; Dugas, Martin

2015-03-01

Electronic medical record (EMR) systems have the potential of supporting clinical work by providing the right information at the right time to the right people and thus make efficient use of resources. This is especially important in low-resource settings where reliable data are also needed to support public health and local supporting organizations. In this systematic literature review, our objectives are to identify and collect literature about success criteria of EMR implementations in low-resource settings and to summarize them into recommendations. Our search strategy relied on PubMed queries and manual bibliography reviews. Studies were included if EMR implementations in low-resource settings were described. The extracted success criteria and measurements were summarized into 7 categories: ethical, financial, functionality, organizational, political, technical, and training. We collected 381 success criteria with 229 measurements from 47 articles out of 223 articles. Most papers were evaluations or lessons learned from African countries, published from 1999 to 2013. Almost half of the EMR systems served a specific disease area like human immunodeficiency virus (HIV). The majority of criteria that were reported dealt with the functionality, followed by organizational issues, and technical infrastructures. Sufficient training and skilled personnel were mentioned in roughly 10%. Political, ethical, and financial considerations did not play a predominant role. More evaluations based on reliable frameworks are needed. Highly reliable data handling methods, human resources and effective project management, as well as technical architecture and infrastructure are all key factors for successful EMR implementation. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Relevant insight of surface characterization techniques to study covalent grafting of a biopolymer to titanium implant and its acidic resistance

Science.gov (United States)

D'Almeida, Mélanie; Amalric, Julien; Brunon, Céline; Grosgogeat, Brigitte; Toury, Bérangère

2015-02-01

Peri-implant bacterial infections are the main cause of complications in dentistry. Our group has previously proposed the attachment of chitosan on titanium implants via a covalent bond to improve its antibacterial properties while maintaining its biocompatibility. A better knowledge of the coating preparation process allows a better understanding of the bioactive coating in biological conditions. In this work, several relevant characterization techniques were used to assess an implant device during its production phase and its resistance in natural media at different pH. The titanium surface was functionalized with 3-aminopropyltriethoxysilane (APTES) followed by grafting of an organic coupling agent; succinic anhydride, able to form two covalent links, with the substrate through a Ti-O-Si bond and the biopolymer through a peptide bond. Each step of the coating synthesis as well as the presence confirmation of the biopolymer on titanium after saliva immersion was followed by FTIR-ATR, SEM, EDS, 3D profilometry, XPS and ToF-SIMS analyses. Results allowed to highlight the efficiency of each step of the process, and to propose a mechanism occurring during the chitosan coating degradation in saliva media at pH 5 and at pH 3.

FY 2000 report on the results of the regional consortium R and D project - Regional consortium energy. First year report. Development of a next generation biopolymer information measuring system based on the nano channel electrophoresis; 2000 nendo chiiki consortium kenkyu kaihatsu jigyo - chiiki consortium energy. Nano channel denki eido ni motozuku jisedai seitai kobunshi joho keisoku system no kaihatsu (dai 1 nendo) seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

On the basis of the nano channel electrophoresis technology, the construction was proceeded with of a system which integrates the basic process such as reaction, separation and detection needed for measuring biopolymer information and analyzes a number of samples simultaneously and with high accuracy/high sensitivity. Studies were made in the following three fields: 1) development of the basement technology on extraction/amplification/separation/detection of biopolymer; 2) development of micro-processing technology and system design and study on the development of device; 3) comprehensive investigational study. In 1), developmental technology is divided into the following: technology to effectively fraction/refine biopolymer from biological samples, technology for recognition control and manipulation of biopolymer, technology of amplification use micro-reaction of biopolymer, multiple selection technology of biopolymer using the specific molecular recognition, and technology for ultra-high speed separation of biopolymer. As to the multiple selection technology, DNA terminal recognizing hemin is altered by thiol group and connected to the surface of electrode to make an electrode type hemin recognition device. (NEDO)

Effective recovery of poly-β-hydroxybutyrate (PHB) biopolymer from Cupriavidus necator using a novel and environmentally friendly solvent system.

Science.gov (United States)

Fei, Tao; Cazeneuve, Stacy; Wen, Zhiyou; Wu, Lei; Wang, Tong

2016-05-01

This work demonstrates a significant advance in bioprocessing for a high-melting lipid polymer. A novel and environmental friendly solvent mixture, acetone/ethanol/propylene carbonate (A/E/P, 1:1:1 v/v/v) was identified for extracting poly-hydroxybutyrate (PHB), a high-value biopolymer, from Cupriavidus necator. A set of solubility curves of PHB in various solvents was established. PHB recovery of 85% and purity of 92% were obtained from defatted dry biomass (DDB) using A/E/P. This solvent mixture is compatible with water, and from non-defatted wet biomass, PHB recovery of 83% and purity of 90% were achieved. Water and hexane were evaluated as anti-solvents to assist PHB precipitation, and hexane improved recovery of PHB from biomass to 92% and the purity to 93%. A scale-up extraction and separation reactor was designed, built and successfully tested. Properties of PHB recovered were not significantly affected by the extraction solvent and conditions, as shown by average molecular weight (1.4 × 10(6) ) and melting point (175.2°C) not being different from PHB extracted using chloroform. Therefore, this biorenewable solvent system was effective and versatile for extracting PHB biopolymers. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:678-685, 2016. © 2016 American Institute of Chemical Engineers.

Physical-biopolymer characterization of polyhydroxybutyrate-co-hydroxyvalerate (PHBV) blended with natural rubber latex

Energy Technology Data Exchange (ETDEWEB)

Kuntanoo, K., E-mail: thip-kk@hotmail.com [Graduate School of Khon Kaen University, Khon Kaen, 40002 Thailand (Thailand); Promkotra, S., E-mail: sarunya@kku.ac.th [Department of Geotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002 Thailand (Thailand); Kaewkannetra, P., E-mail: paknar@kku.ac.th [Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002 Thailand (Thailand)

2015-03-30

A biopolymer of polyhydroxybutyrate-co-hydroxyvalerate (PHBV) is blended with bio-based materials, natural rubber latex, to improve their microstructures. The various ratios between PHBV and natural rubber latex are examined to develop their mechanical properties. In general, physical properties of PHBV are hard, brittle and low flexible while natural rubber (NR) is presented itself as high elastic materials. Concentrations of the PHBV solution are constituted at 1%, 2% and 3% (w/v). The mixtures of their PHBV solutions to natural rubber latex are produced the blended films in three different ratios of 4:6, 5:5 and 6:4, respectively. They are characterized by appearance analyses which are the scanning electron microscope (SEM), universal testing machine (UTM) and differential scanning calorimetry (DSC). The SEM photomicrographs of the blended films and the controlled PHBV can provide the void distribution in the range of 12-14% and 19-21%, respectively. For mechanical properties of the blended films, the various elastic moduli of 1%, 2% and 3% (w/v) PHBV are the average of 773, 956 and 1,007 kPa, respectively. The tensile strengths of the blends increase with the increased concentrations of PHBV, similarly trend to the elastic modulus. The crystallization and melting behavior of unmixed PHBV and the blends are determined by DSC. Melting transition temperatures (T{sub m}) of the unmixed PHBV are stated two melting peak at 154°C and 173°C. Besides, the melting peaks of the blends alter in the range of 152-156°C and 168-171°C, respectively. According to morphology of the blends, the void distribution decreases twice compared to the unmixed PHBV. The results of mechanical properties and thermal analysis indicate that the blended PHBV can be developed their properties by more resilient and wide range of temperature than usual.

Nonlinear optical probe of biopolymer adsorption on colloidal particle surface: poly-L-lysine on polystyrene sulfate microspheres.

Science.gov (United States)

Eckenrode, Heather M; Dai, Hai-Lung

2004-10-12

A nonlinear optical technique--second harmonic generation (SHG)--has been applied to characterize the adsorption of poly-L-lysine on micrometer size polystyrene particles, whose surface is covered with negatively charged sulfonate groups, in aqueous solutions. Adsorption behavior of the biopolymer with two chain lengths (14 and 75 amino acid units; PL14 and PL75) has been examined. Centrifugation experiments were also performed to support the adsorption measurements made using SHG. The adsorption free energies of the two polymers PL75 and PL14 are determined as -16.57 and -14.40 kcal/mol, respectively. The small difference in the adsorption free energies of the two chain lengths, however, leads to dramatic difference in the concentration needed for saturated surface coverage: nearly 50 times higher concentration is needed for the smaller polymer. Under acidic colloidal conditions, polylysine is found to adsorb in a relatively flat conformation on the surface. The surface area that each polylysine molecule occupies is nearly 1 order of magnitude larger than the size of the molecule in its extended form. The low adsorption density is likely a result from Coulombic repulsion between the positive charges on the amino acid units of PL. The measurements demonstrate the utility of SHG as an efficient and sensitive experimental approach for measuring adsorption characteristics of bio/macromolecules on colloidal particles and define surface and colloidal conditions for achieving maximum surface coverage of a widely used biopolymer. Copyright 2004 American Chemical Society

Biopolymers for sample collection, protection, and preservation.

Science.gov (United States)

Sorokulova, Iryna; Olsen, Eric; Vodyanoy, Vitaly

2015-07-01

One of the principal challenges in the collection of biological samples from air, water, and soil matrices is that the target agents are not stable enough to be transferred from the collection point to the laboratory of choice without experiencing significant degradation and loss of viability. At present, there is no method to transport biological samples over considerable distances safely, efficiently, and cost-effectively without the use of ice or refrigeration. Current techniques of protection and preservation of biological materials have serious drawbacks. Many known techniques of preservation cause structural damages, so that biological materials lose their structural integrity and viability. We review applications of a novel bacterial preservation process, which is nontoxic and water soluble and allows for the storage of samples without refrigeration. The method is capable of protecting the biological sample from the effects of environment for extended periods of time and then allows for the easy release of these collected biological materials from the protective medium without structural or DNA damage. Strategies for sample collection, preservation, and shipment of bacterial, viral samples are described. The water-soluble polymer is used to immobilize the biological material by replacing the water molecules within the sample with molecules of the biopolymer. The cured polymer results in a solid protective film that is stable to many organic solvents, but quickly removed by the application of the water-based solution. The process of immobilization does not require the use of any additives, accelerators, or plastifiers and does not involve high temperature or radiation to promote polymerization.

Inorganic nanoparticles for the spatial and temporal control of organic reactions: Applications to radical degradation of biopolymer networks

Science.gov (United States)

Walker, Joan Marie

Nanoparticles of gold and iron oxide not only possess remarkable optical and magnetic properties, respectively, but are also capable of influencing their local environment with an astounding degree of precision. Using nanoparticles to direct the reactivity of organic molecules near their surface provides a unique method of spatial and temporal control. Enediynes represent an exceptional class of compounds that are thermally reactive to produce a diradical intermediate via Bergman cycloaromatization. While natural product enediynes are famously cytotoxic, a rich chemistry of synthetic enediynes has developed utilizing creative means to control this reactivity through structure, electronics, metal chelation, and external triggering mechanisms. In a heretofore unexplored arena for Bergman cyclization, we have investigated the reactivity of enediynes in connection with inorganic nanoparticles in which the physical properties of the nanomaterial are directly excited to thermally promote aromatization. As the first example of this methodology, gold nanoparticles conjugated with (Z)-octa-4-en-2,6-diyne-1,8-dithiol were excited with 514 nm laser irradiation. The formation of aromatic and polymeric products was confirmed through Raman spectroscopy and electron microscopy. Water soluble analogues Au-PEG-EDDA and Fe3O4-PEG-EDDA (EDDA = (Z)-octa-4-en-2,6-diyne-1,8-diamine) show similar reactivity under laser irradiation or alternating magnetic field excitation, respectively. Furthermore, we have used these functionalized nanoparticles to attack proteinaceous substrates including fibrin and extracellular matrix proteins, capitalizing on the ability of diradicals to disrupt peptidic bonds. By delivering a locally high payload of reactive molecules and thermal energy to the large biopolymer, network restructuring and collapse is achieved. As a synthetic extension towards multifunctional nanoparticles, noble metal seed-decorated iron oxides have also been prepared and assessed for

Production of novel biopolymers in plants: recent technological advances and future prospects.

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Snell, Kristi D; Singh, Vijay; Brumbley, Stevens M

2015-04-01

The production of novel biopolymers in plants has the potential to provide renewable sources of industrial materials through agriculture. In this review we will highlight recent progress with plant-based production of polyhydroxyalkanoates (PHAs), silk, elastin, collagen, and cyanophycin with an emphasis on the synthesis of poly[(R)-3-hydroxybutyrate] (PHB), a renewable biodegradable PHA polymer with potential commercial applications in plastics, chemicals, and feed markets. Improved production of PHB has required manipulation of promoters driving expression of transgenes, reduction in activity of endogenous enzymes in competing metabolic pathways, insertion of genes to increase carbon flow to polymer, and basic plant biochemistry to understand metabolic limitations. These experiments have increased our understanding of carbon availability and partitioning in different plant organelles, cell types, and organs, information that is useful for the production of other novel molecules in plants. Copyright © 2014 Elsevier Ltd. All rights reserved.

Electronic Human Resources Management (e-HRM Adoption Studies: Past and Future Research

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Winarto Winarto

2018-05-01

Full Text Available Electronic human resource management (e-HRM systems become more widely used by profit and non-profit organization. However, the field currently lacks sound theoretical frameworks that can be useful in addressing a key issue concerning the implementation of e-HRM systems, in particular to obtain a better understanding of the factors influencing the adoption of e-HRM systems. The objective of this paper is to provide a foundation towards the development of a theoretical framework for the implementation of e-HRM systems and develop a conceptual model that would reflect the nature of e-HRM systems’ adoption through systematic literature review. Adopting Crossan and Apaydin’s procedure of systematic review, this paper investigated 21 empirical papers of electronics human resources management, then categorized them into 4 characteristics which influence the adoption; System and technology characteristics; Organizational characteristics; User/individual characteristics, and Environmental and contextual characteristics. Finally, the e-HRM adoption research framework is drawn and based on the framework; avenues for future research are discussed.   Bahasa Indonesia Abstrak: Manajemen sumber daya manusia elektronik (selanjutnya disebut dengan e-HRM semakin banyak digunakan oleh organisasi profit dan nonprofit. Namun, bidang dan topik ini belum memiliki kerangka teori yang mapan, yang dapat digunakan untuk menganalisis isu-isu terkait penerapan e-HRM, terutama mengenai faktor-faktor yang mempengaruhi adopsi sistem e-HRM. Tujuan penelitian ini adalah untuk memberikan landasan bagi pengembangan kerangka teoritis untuk implementasi sistem e-HRM dan mengembangkan model konseptual yang akan menggambarkan adopsi sistem e-HRM melalui tinjauan literatur sistematis. Mengadopsi prosedur dan metode Crossan dan Apaydin untuk melakukan telaah literatur secara sistematis, paper ini menyelidiki 21 publikasi empiris manajemen sumber daya manusia elektronik dari 2

Tunable deformation modes shape contractility in active biopolymer networks

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Stam, Samantha; Banerjee, Shiladitya; Weirich, Kim; Freedman, Simon; Dinner, Aaron; Gardel, Margaret

Biological polymer-based materials remodel under active, molecular motor-driven forces to perform diverse physiological roles, such as force transmission and spatial self-organization. Critical to understanding these biomaterials is elucidating the role of microscopic polymer deformations, such as stretching, bending, buckling, and relative sliding, on material remodeling. Here, we report that the shape of motor-driven deformations can be used to identify microscopic deformation modes and determine how they propagate to longer length scales. In cross-linked actin networks with sufficiently low densities of the motor protein myosin II, microscopic network deformations are predominantly uniaxial, or dominated by sliding. However, longer-wavelength modes are mostly biaxial, or dominated by bending and buckling, indicating that deformations with uniaxial shapes do not propagate across length scales significantly larger than that of individual polymers. As the density of myosin II is increased, biaxial modes dominate on all length scales we examine due to buildup of sufficient stress to produce smaller-wavelength buckling. In contrast, when we construct networks from unipolar, rigid actin bundles, we observe uniaxial, sliding-based contractions on 1 to 100 μm length scales. Our results demonstrate the biopolymer mechanics can be used to tune deformation modes which, in turn, control shape changes in active materials.

Electron beam technology for modifying the functional properties of maize starch

International Nuclear Information System (INIS)

Nemtanu, M.R.; Minea, R.; Kahraman, K.; Koksel, H.; Ng, P.K.W.; Popescu, M.I.; Mitru, E.

2007-01-01

Maize starch is a versatile biopolymer with a wide field of applications (e.g. foods, pharmaceutical products, adhesives, etc.). Nowadays there is a continuous and intensive search for new methods and techniques to modify its functional properties due to the fact that native form of starch may exhibit some disadvantages in certain applications. Radiation technology is frequently used to change the properties of different polymeric materials. Thus, the goal of the work is to discuss the application of accelerated electron beams on maize starch in the view of changing some of its functional properties. Maize starch has been irradiated with doses up to 52.15 kGy by using electron beam technology and the modifications of differential scanning calorimetry (DSC) and pasting characteristics, paste clarity, freezing and thawing stability as well as colorimetric characteristics have been investigated. The results of the study revealed that the measured properties can be modified by electron beam treatment and, therefore, this method can be an efficient and ecological alternative to obtain modified maize starch

Improving Electronic Resources through Holistic Budgeting

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Kusik, James P.; Vargas, Mark A.

2009-01-01

To establish a more direct link between its collections and the educational goals of Saint Xavier University, the Byrne Memorial Library has adopted a "holistic" approach to collection development. This article examines how traditional budget practices influenced the library's selection of resources and describes how holistic collection…

Interactive association between biopolymers and biofunctions in carinata seeds as energy feedstock and their coproducts (carinata meal) from biofuel and bio-oil processing before and after biodegradation: current advanced molecular spectroscopic investigations.

Science.gov (United States)

Yu, Peiqiang; Xin, Hangshu; Ban, Yajing; Zhang, Xuewei

2014-05-07

Recent advances in biofuel and bio-oil processing technology require huge supplies of energy feedstocks for processing. Very recently, new carinata seeds have been developed as energy feedstocks for biofuel and bio-oil production. The processing results in a large amount of coproducts, which are carinata meal. To date, there is no systematic study on interactive association between biopolymers and biofunctions in carinata seed as energy feedstocks for biofuel and bioethanol processing and their processing coproducts (carinata meal). Molecular spectroscopy with synchrotron and globar sources is a rapid and noninvasive analytical technique and is able to investigate molecular structure conformation in relation to biopolymer functions and bioavailability. However, to date, these techniques are seldom used in biofuel and bioethanol processing in other research laboratories. This paper aims to provide research progress and updates with molecular spectroscopy on the energy feedstock (carinata seed) and coproducts (carinata meal) from biofuel and bioethanol processing and show how to use these molecular techniques to study the interactive association between biopolymers and biofunctions in the energy feedstocks and their coproducts (carinata meal) from biofuel and bio-oil processing before and after biodegradation.

Clinician‐selected Electronic Information Resources do not Guarantee Accuracy in Answering Primary Care Physicians’ Information Needs. A review of: McKibbon, K. Ann, and Douglas B. Fridsma. “Effectiveness of Clinician‐selected Electronic Information Resources for Answering Primary Care Physicians’ Information Needs.” Journal of the American Medical Informatics Association 13.6 (2006: 653‐9.

Directory of Open Access Journals (Sweden)

Martha Ingrid Preddie

2008-03-01

Full Text Available Objective – To determine if electronic information resources selected by primary care physicians improve their ability to answer simulated clinical questions.Design – An observational study utilizing hour‐long interviews and think‐aloud protocols.Setting – The offices and clinics of primary care physicians in Canada and the United States.Subjects – Twenty‐five primary care physicians of whom 4 were women, 17 were from Canada, 22 were family physicians,and 24 were board certified.Methods – Participants provided responses to 23 multiple‐choice questions. Each physician then chose two questions and looked for the answers utilizing information resources of their own choice. The search processes, chosen resources and search times were noted. These were analyzed along with data on the accuracy of the answers and certainties related to the answer to each clinical question prior to the search.Main results – Twenty‐three physicians sought answers to 46 simulated clinical questions. Utilizing only electronic information resources, physicians spent a mean of 13.0 (SD 5.5 minutes searching for answers to the questions, an average of 7.3(SD 4.0 minutes for the first question and 5.8 (SD 2.2 minutes to answer the second question. On average, 1.8 resources were utilized per question. Resources that summarized information, such as the Cochrane Database of Systematic Reviews, UpToDate and Clinical Evidence, were favored 39.2% of the time, MEDLINE (Ovid and PubMed 35.7%, and Internet resources including Google 22.6%. Almost 50% of the search and retrieval strategies were keyword‐based, while MeSH, subheadings and limiting were used less frequently. On average, before searching physicians answered 10 of 23 (43.5% questions accurately. For questions that were searched using clinician‐selected electronic resources, 18 (39.1% of the 46 answers were accurate before searching, while 19 (42.1% were accurate after searching. The difference of

Properties of films obtained from biopolymers of different origins for skin lesions therapy

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Márcia Zilioli Bellini

2015-04-01

Full Text Available In this study, the effects of the origin of xanthan used, in combination with chitosan, to prepare films for the treatment of skin lesions were evaluated. The characteristics of the films obtained with xanthan commercially available for the food industry sector and xanthan originated from a fermentation process conducted in a pilot plant were compared. Results showed that the source did not strongly interfere in many of the properties of the films, such as the mechanical properties, cytotoxicity to L929 cells, absorption of simulated body fluid and culture medium, stability in water and saline solution. Hence, even though the properties of biopolymers of different sources might vary, the films prepared with two distinct types of xanthan gum could be considered as potentially safe and similar in terms of relevant characteristics considering the aimed application.

Review of material recovery from used electric and electronic equipment-alternative options for resource conservation.

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Friege, Henning

2012-09-01

For waste from electric and electronic equipment, the WEEE Directive stipulates the separate collection of electric and electronic waste. As to new electric and electronic devices, the Restriction of Hazardous Substances (RoHS) Directive bans the use of certain chemicals dangerous for man and environment. From the implementation of the WEEE directive, many unsolved problems have been documented: poor collection success, emission of dangerous substances during collection and recycling, irretrievable loss of valuable metals among others. As to RoHS, data from the literature show a satisfying success. The problems identified in the process can be reduced to some basic dilemmas at the borders between waste management, product policy and chemical safety. The objectives of the WEEE Directive and the specific targets for use and recycling of appliances are not consistent. There is no focus on scarce resources. Extended producer responsibility is not sufficient to guarantee sustainable waste management. Waste management reaches its limits due to problems of implementation but also due to physical laws. A holistic approach is necessary looking at all branch points and sinks in the stream of used products and waste from electric and electronic equipment. This may be done with respect to the general rules for sustainable management of material streams covering the three dimensions of sustainable policy. The relationships between the players in the field of electric and electronic devices have to be taken into account. Most of the problems identified in the implementation process will not be solved by the current amendment of the WEEE Directive.

Charting a Course through CORAL: Texas A&M University Libraries' Experience Implementing an Open-Source Electronic Resources Management System

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Hartnett, Eric; Beh, Eugenia; Resnick, Taryn; Ugaz, Ana; Tabacaru, Simona

2013-01-01

In 2010, after two previous unsuccessful attempts at electronic resources management system (ERMS) implementation, Texas A&M University (TAMU) Libraries set out once again to find an ERMS that would fit its needs. After surveying the field, TAMU Libraries selected the University of Notre Dame Hesburgh Libraries-developed, open-source ERMS,…

Obtention of gelatin biopolymers by ionizing radiation; Obtencao de biopolimeros de gelatina por radiacao ionizante

Energy Technology Data Exchange (ETDEWEB)

Takinami, Patricia Yoko Inamura

2014-07-01

The gelatin (Gel) is a biocompatible and biodegradable biopolymer, which naturally forms semi-solid colloids or hydrogels in aqueous solutions. As a hydrophilic polymer, the Gel has structural and physico-mechanical properties that distinguish it from synthetic hydrophilic polymers. The study of these properties led to the development of the present work. Thus, Gel-based films and hydrogels were developed using ionizing radiation technology by different techniques: irradiation with {sup 60}Co, electron beam (EB) and/or pulsed EB. The Gel based-films enriched with different additives, such as glycerol (GLY), polyvinyl alcohol (PVA), butylated hydroxytoluene (BHT), acrylamide and/or vegetal fiber, were irradiated with doses from 10 to 60 kGy, depending on the additive; some parameters like mechanical properties, color, and water absorption were analyzed. In the radio-induced synthesis of GEL nanohydrogels, polyethylene glycol (PEG) and the mixture (MIX) of additives, PEG and GEL, the size, molar mass and surface morphology of the nanohydrogels were analyzed. There was a significant increase of gel fraction with increase of the radiation dose for the GEL/fiber samples. The GEL based-films with 10% PVA irradiated at 20 kGy showed the highest puncture strength. The addition of antioxidant BHT affected on some GEL based-films properties on applied conditions. Regarding the nanohydrogels, there was a decrease of hydrodynamic radius of MIX irradiated with {sup 60}Co from 68 ± 25 nm (2 kGy) to 35 ± 4 nm (5 kGy). The radiation proved to be a convenient tool in the modification of polymeric materials for both, GEL films and hydrogels. (author)

Fractional Generalizations of Maxwell and Kelvin-Voigt Models for Biopolymer Characterization.

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Bertrand Jóźwiak

Full Text Available The paper proposes a fractional generalization of the Maxwell and Kelvin-Voigt rheological models for a description of dynamic behavior of biopolymer materials. It was found that the rheological models of Maxwell-type do not work in the case of modeling of viscoelastic solids, and the model which significantly better describes the nature of changes in rheological properties of such media is the modified fractional Kelvin-Voigt model with two built-in springpots (MFKVM2. The proposed model was used to describe the experimental data from the oscillatory and creep tests of 3% (w/v kuzu starch pastes, and to determine the values of their rheological parameters as a function of pasting time. These parameters provide a lot of additional information about structure and viscoelastic properties of the medium in comparison to the classical analysis of dynamic curves G' and G" and shear creep compliance J(t. It allowed for a comprehensive description of a wide range of properties of kuzu starch pastes, depending on the conditions of pasting process.

Strategies for Automated Control of the Bioproduction of Mcl-PHA Biopolymers

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P. Hrnčiřík

2017-10-01

Full Text Available Medium-chain-length polyhydroxyalkanoates (mcl-PHAs are polyesters synthesized by numerous bacteria as storage material. Despite being promising candidates for biodegradable materials of industrial interest and environmental value, their usage is still rather limited because of high production costs. One of the areas with considerable potential for further improvements is control of the production process. This paper deals with the experimental work related to the design of control strategies for mcl-PHA biopolymer production process (Pseudomonas putida KT2442 fed-batch cultivations. For this bioprocess, a set of five control strategies (two main and three auxiliary strategies have been proposed, together with the proper sequence of their switching during the fed-batch part of the production process. The application of these strategies with octanoic acid as a sole carbon source resulted in intracellular PHA content (max. mass fraction 65 % of mcl-PHA in cell dry mass (g g–1 and PHA productivity (max. 0.89 g L–1 h–1 comparable to the best results reported in the literature for this type of strain and carbon substrate.

Rapid communication: Computational simulation and analysis of a candidate for the design of a novel silk-based biopolymer.

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Golas, Ewa I; Czaplewski, Cezary

2014-09-01

This work theoretically investigates the mechanical properties of a novel silk-derived biopolymer as polymerized in silico from sericin and elastin-like monomers. Molecular Dynamics simulations and Steered Molecular Dynamics were the principal computational methods used, the latter of which applies an external force onto the system and thereby enables an observation of its response to stress. The models explored herein are single-molecule approximations, and primarily serve as tools in a rational design process for the preliminary assessment of properties in a new material candidate. © 2014 Wiley Periodicals, Inc.

Bio-orthogonal Fluorescent Labelling of Biopolymers through Inverse-Electron-Demand Diels-Alder Reactions.

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Kozma, Eszter; Demeter, Orsolya; Kele, Péter

2017-03-16

Bio-orthogonal labelling schemes based on inverse-electron-demand Diels-Alder (IEDDA) cycloaddition have attracted much attention in chemical biology recently. The appealing features of this reaction, such as the fast reaction kinetics, fully bio-orthogonal nature and high selectivity, have helped chemical biologists gain deeper understanding of biochemical processes at the molecular level. Listing the components and discussing the possibilities and limitations of these reagents, we provide a recent snapshot of the field of IEDDA-based biomolecular manipulation with special focus on fluorescent modulation approaches through the use of bio-orthogonalized building blocks. At the end, we discuss challenges that need to be addressed for further developments in order to overcome recent limitations and to enable researchers to answer biomolecular questions in more detail. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Designing a model of electronic human resource management’s implementation at the Ministry of Communications and Information Technology

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Mirali Seyednaghavi

2017-06-01

Full Text Available : In the first phase of this study a model for electronic human resource management in government agencies based on new public services was explored by using software MAXQDA, then in the second phase, relationship between the elements of the theory were tested using software Smart PLS2. So the aim of this study is to design a model of electronic human resource management’s implementation at the Ministry of Communications and Information Technology. In this regard, according to Strauss and Corbin’s structured plan, five hypotheses were tested. Quantitative data analysis indicates that the pressures of the policies and global perspectives cause to move toward e-HRM. Among the contextual conditions macro structural mechanisms, considerations of actors, governance considerations have a significant impact on the strategy of new public services and therefore lead to the consequences of its implementation in public organizations. The findings suggest that e-HRM does not have a positive and meaningful impact on new public services, and in our country, although the recent political developments have somehow removed the gap between public policy makers, administrators, and the public, but there is still a long way to go.

Preparation and characterization of biopolymers comprising chitosan-grafted-ENR via acid-induced reaction of ENR50 with chitosan

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M. R. H. Mas Haris

2014-02-01

Full Text Available This paper describes the first detailed tailored-approach for the preparation of biopolymers comprising chitosan (CTS grafted onto the backbone of epoxidized natural rubber (CTS-g-ENR. In a typical experiment, appropriate amount of CTS and AlCl3•6H2O was added to a specified amount of ENR50 (ENR with about 50% epoxy content dissolved in a dual-solvent consisting of 1,4-dioxane and water (97.5:2.5% v/v and the resulting mixture refluxed with continuous stirring for 6 hours. Nuclear magnetic resonance (NMR spectral analysis of a biocomposite, CTS-g-ENR-P1, revealed that its epoxy content is 22.36% which is considerably lower than 44.93% as determined for ENR50-control (ENR50 derivative obtained under similar experimental condition but in the absence of CTS. This means that the grafting of CTS onto the backbone of ENR had occurred. The revelation is affirmed by the presence of the characteristic absorption bands of CTS and ENR, and the appearance of new bands at 1219, 902 and 733 cm–1 in the Fourier transform infrared (FTIR spectrum of CTS-g-ENR-P1. Further evidence that CTS had been successfully grafted onto the backbone of ENR can be deduced and described in this paper from the data obtained by means of Differential Scanning Calorimetric analysis, Thermogravimetric analysis and Variable Pressure Scanning Electron Microscopy.

The module of methodical support in system of electronic educational resources as the innovative element of the modern maintenance of formation

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Ольга Николаевна Крылова

2009-06-01

Full Text Available The article introduces some results of research, which were devoted to evaluation of tearches' mobility to introduce innovations in the contents of education. The author considers innovative potential of modules of the methodical support for system of electronic educational resources.

Impact of Electronic Resources and Usage in Academic Libraries in Ghana: Evidence from Koforidua Polytechnic & All Nations University College, Ghana

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Akussah, Maxwell; Asante, Edward; Adu-Sarkodee, Rosemary

2015-01-01

The study investigates the relationship between impact of electronic resources and its usage in academic libraries in Ghana: evidence from Koforidua Polytechnic & All Nations University College, Ghana. The study was a quantitative approach using questionnaire to gather data and information. A valid response rate of 58.5% was assumed. SPSS…

Development of pH-responsive biopolymer-silica composites loaded with Larrea divaricata Cav. extract with antioxidant activity.

Science.gov (United States)

Alvarez Echazú, María Inés; Olivetti, Christian Ezequiel; Peralta, Ignacio; Alonso, Maria Rosario; Anesini, Claudia; Perez, Claudio Javier; Alvarez, Gisela Solange; Desimone, Martin Federico

2018-05-07

A detailed study of biomaterials is mandatory to comprehend their feasible biomedical applications in terms of drug delivery and tissue regeneration. Particularly, mucoadhesive biopolymers such as chitosan (chi) and carboxymethylcellulose (CMC) have become interesting biomaterials regards to their biocompatibility and non-toxicity for oral mucosal drug delivery. In this work, pH-responsive biopolymer-silica composites (Chi-SiO 2 , Chi-CMC-SiO 2 ) were developed. These two types of composites presented a different swelling behavior due to the environmental pH. Moreover, the nanocomposites were loaded with aqueous Larrea divaricata Cav. extract (Ld), a South American plant which presents antioxidant properties suitable for the treatment of gingivoperiodontal diseases. Chi-CMC-SiO 2 composites showed the highest incorporation and reached the 100% of extract release in almost 4 days while they preserved their antioxidant properties. In this study, thermal and swelling behavior were pointed out to show the distinct water-composite interaction and therefore to evaluate their mucoadhesivity. Furthermore, a cytotoxicity test with 3T3 fibroblasts was assessed, showing that in both composites the addition of Larrea divaricata Cav. extract increased fibroblast proliferation. Lastly, preliminary in vitro studies were performed with simulated body fluids. Indeed, SEM-EDS analysis indicated that only chi-SiO 2 composite may provide an environment for possible biomineralization while the addition of CMC to the composites discouraged calcium accumulation. In conclusion, the development of bioactive composites could promote the regeneration of periodontal tissue damaged throughout periodontal disease and the presence of silica nanoparticles could provide an environment for biomineralization. Copyright © 2018 Elsevier B.V. All rights reserved.

Study of Thermal Properties, Turbidity, Effective Factors on Particle Size and Oscillatory Rheology of Pectin-Caseinate Biopolymer Nanocomplexes

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Sajedeh Bahrani

2013-02-01

Full Text Available The biopolymer-based nanocomplexes are a group of nanocapsules that are used for encapsulation and control delivery of nutraceuticals. They are formed by binding of proteins and polysaccharides. In this study, complex formation between pectin and sodium caseinate was taken place by addition of pectin solutions(0.2, 0.45 and 0.7 % w/v into the caseinate solutions (0.5, 1 and 1.5 % w/v and adjusted their pH below isoelecteric point of sodium caseinate. The effect of various factors such as biopolymer concentration, salt concentration, temperature and time of ultrasound on the properties of pectin-casein nanocomplexes was investigated. Differential scanning calorimetry (DSC and particle size analyzer were used for study of complex formation and particle size determination, respectively. The results of DSC and turbidimetry showed complex formation between the pectin and casein at pH below 5 and the results of particle size showed formation of stable dispersion with a minimum size of 86 nm at pH 4.1, caseinate of 1 % w/v and pectin 0.45 % w/v concentration. The ultrasound for more than 1 min reduced particle size and addition of salt at high and low concentrations had different effects on the stability of the colloidal system. The lowering of temperature from 21 to 4°C resulted in smaller particle size of nanocomplexes. The oscillatory rheological results showed that with increasing pectin concentration, viscoelastic moduli were increased and loss moduli were higher than storage modulus.

Characterization of the mechanical properties of tough biopolymer fibres from the mussel byssus of Aulacomya ater.

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Troncoso, O P; Torres, F G; Grande, C J

2008-07-01

Byssus fibres are tough biopolymer fibres produced by mussels to attach themselves to rocks. In this communication, we present the mechanical properties of the byssus from the South American mussel Aulacomya ater which have not been previously reported in the literature. The mechanical properties of the whole threads were assessed by uniaxial tensile tests of dry and hydrated specimens. Elastoplastic and elastomeric stress-strain curves were found for byssal threads from A. ater in the dry and hydrated state, respectively. The results obtained from mechanical tests were modelled using linear, power-law-type and Mooney-Rivlin relationships. These methods for dealing with tensile measurements of mussel byssus have the potential to be used with other stretchy biomaterials.

Utilization of Electronic Information Resources by Undergraduate Students of University of Ibadan: A Case Study of Social Sciences and Education

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Owolabi, Sola; Idowu, Oluwafemi A.; Okocha, Foluke; Ogundare, Atinuke Omotayo

2016-01-01

The study evaluated utilization of electronic information resources by undergraduates in the Faculties of Education and the Social Sciences in University of Ibadan. The study adopted a descriptive survey design with a study population of 1872 undergraduates in the Faculties of Education and the Social Sciences in University of Ibadan, from which a…

Shaping the Electronic Library--The UW-Madison Approach.

Science.gov (United States)

Dean, Charles W., Ed.; Frazier, Ken; Pope, Nolan F.; Gorman, Peter C.; Dentinger, Sue; Boston, Jeanne; Phillips, Hugh; Daggett, Steven C.; Lundquist, Mitch; McClung, Mark; Riley, Curran; Allan, Craig; Waugh, David

1998-01-01

This special theme section describes the University of Wisconsin-Madison's experience building its Electronic Library. Highlights include integrating resources and services; the administrative framework; the public electronic library, including electronic publishing capability and access to World Wide Web-based and other electronic resources;…

Biopolymer-based hydrogels as injectable materials for tissue repair scaffolds

International Nuclear Information System (INIS)

Fiejdasz, Sylwia; Szczubiałka, Krzysztof; Lewandowska-Łańcucka, Joanna; Nowakowska, Maria; Osyczka, Anna M

2013-01-01

The progress in tissue regeneration is strongly dependent on the development of biocompatible materials with properties resembling those of a native tissue. Also, the application of noninvasive methods of delivering the scaffold into the tissue defect is of great importance. In this study we present a group of biopolymer-based materials as potential injectable scaffolds. In contrast to other studies involving collagen neutralization or additional incubation of gel in genipin solution, we propose collagen and collagen–chitosan gels crosslinked in situ with genipin. Since some parameters of the cells should be considered in the microscale, the steady-state fluorescence anisotropy was applied to study the microenvironment of the gels. To our knowledge we are the first to report on microrheological properties, such as gel time and microviscosity, for this group of hydrogels. Rapid gelation at physiological temperatures found makes these materials of special interest in applications requiring gel injectability. Physico-chemical investigation showed the influence of the crosslinking agent concentration and chitosan addition on the crosslinking degree, swelling ratio, gel microviscosity, and the degradation rate. Strong correlation was revealed between the surface wettability and the viability of cultured mesenchymal stem cells. Cytotoxicity studies indicated that the collagen–chitosan hydrogels showed the best biocompatibility. (paper)

Controlling user access to electronic resources without password

Science.gov (United States)

Smith, Fred Hewitt

2017-08-22

Described herein are devices and techniques for remotely controlling user access to a restricted computer resource. The process includes obtaining an image from a communication device of a user. An individual and a landmark are identified within the image. Determinations are made that the individual is the user and that the landmark is a predetermined landmark. Access to a restricted computing resource is granted based on the determining that the individual is the user and that the landmark is the predetermined landmark. Other embodiments are disclosed.

The use of quality benchmarking in assessing web resources for the dermatology virtual branch library of the National electronic Library for Health (NeLH).

Science.gov (United States)

Kamel Boulos, M N; Roudsari, A V; Gordon, C; Muir Gray, J A

2001-01-01

In 1998, the U.K. National Health Service Information for Health Strategy proposed the implementation of a National electronic Library for Health to provide clinicians, healthcare managers and planners, patients and the public with easy, round the clock access to high quality, up-to-date electronic information on health and healthcare. The Virtual Branch Libraries are among the most important components of the National electronic Library for Health. They aim at creating online knowledge based communities, each concerned with some specific clinical and other health-related topics. This study is about the envisaged Dermatology Virtual Branch Libraries of the National electronic Library for Health. It aims at selecting suitable dermatology Web resources for inclusion in the forthcoming Virtual Branch Libraries after establishing preliminary quality benchmarking rules for this task. Psoriasis, being a common dermatological condition, has been chosen as a starting point. Because quality is a principal concern of the National electronic Library for Health, the study includes a review of the major quality benchmarking systems available today for assessing health-related Web sites. The methodology of developing a quality benchmarking system has been also reviewed. Aided by metasearch Web tools, candidate resources were hand-selected in light of the reviewed benchmarking systems and specific criteria set by the authors. Over 90 professional and patient-oriented Web resources on psoriasis and dermatology in general are suggested for inclusion in the forthcoming Dermatology Virtual Branch Libraries. The idea of an all-in knowledge-hallmarking instrument for the National electronic Library for Health is also proposed based on the reviewed quality benchmarking systems. Skilled, methodical, organized human reviewing, selection and filtering based on well-defined quality appraisal criteria seems likely to be the key ingredient in the envisaged National electronic Library for

There is a Relationship between Resource Expenditures and Reference Transactions in Academic Libraries. A Review of: Dubnjakovic, A. (2012. Electronic resource expenditure and the decline in reference transaction statistics in academic libraries. Journal of Academic Librarianship, 38(2, 94-100. doi:10.1016/j.acalib.2012.01.001

Directory of Open Access Journals (Sweden)

Annie M. Hughes

2013-03-01

Full Text Available Objective – To provide an analysis of the impact of expenditures on electronic resourcesand gate counts on the increase or decrease in reference transactions.Design – Analysis of results of existing survey data from the National Center for Educational Statistics (NCES 2006 Academic Library Survey(ALS.Setting – Academic libraries in the United States.Subjects – 3925 academic library respondents.Methods – The author chose to use survey data collected from the 2006 ALS conducted bythe NCES. The survey included data on various topics related to academic libraries, but in the case of this study, the author chose to analyze three of the 193 variables included. The three variables: electronic books expenditure, computer hardware and software, and expenditures on bibliographic utilities, were combined into one variable called electronic resource expenditure. Gate counts were also considered as a variable. Electronic resource expenditure was also split as a variable into three groups: low, medium, and high. Multiple regression analysis and general linear modeling, along with tests of reliability, were employed. Main Results – The author determined that low, medium, and high spenders with regard to electronic resources exhibited differences in gate counts, and gate counts have an effect on reference transactions in any given week. Gate counts tend to not have much of an effect on reference transactions for the higher spenders, and higher spenders tend to have a higher number of reference transactions overall. Low spenders have lower gate counts and also a lower amount of reference transactions.Conclusion – The findings from this study show that academic libraries spending more on electronic resources also tend to have an increase with regard to reference transactions. The author also concludes that library spaces are no longer the determining factor with regard to number of reference transactions. Spending more on electronic resources is

Electronic resources access and usage among the postgraduates of ...

African Journals Online (AJOL)

... and usage among the postgraduates of a Nigerian University of Technology. ... faced by postgraduates in using e-resources include takes too much time to find, ... Resources, Access, Use, Postgraduat, Students, University, Technology, Nigeria ... By Country · List All Titles · Free To Read Titles This Journal is Open Access.

Green synthesis of biopolymer-silver nanoparticle nanocomposite: an optical sensor for ammonia detection.

Science.gov (United States)

Pandey, Sadanand; Goswami, Gopal K; Nanda, Karuna K

2012-11-01

Biopolymer used for the production of nanoparticles (NPs) has attracted increasing attention. In the presence article we use aqueous solution of polysaccharide Cyamopsis tetragonaloba commonly known as guar gum (GG), from plants. GG acts as reductive preparation of silver nanoparticles which are found to be powder X-ray diffraction technique. Aqueous ammonia sensing study of polymer/silver nanoparticles nanocomposite (GG/AgNPs NC) was performed by optical method based on surface plasmon resonance (SPR). The performances of optical sensor were investigated which provide the excellent result. The response time of 2-3 s and the detection limit of ammonia solution, 1 ppm were found at room temperature. Thus, in future this room temperature optical ammonia sensor can be used for clinical and medical diagnosis for detecting low ammonia level in biological fluids, such as plasma, sweat, saliva, cerebrospinal liquid or biological samples in general for various biomedical applications in human. Copyright © 2012 Elsevier B.V. All rights reserved.

Effect of Nanopore Length on the Translocation Process of a Biopolymer: Numerical Study

Directory of Open Access Journals (Sweden)

Yong Kweon Suh

2013-09-01

Full Text Available In this study, we simulate the electrophoretic motion of a bio-polymer through a synthetic nanopore in the presence of an external bias voltage by considering the hydrodynamic interactions between the polymer and the fluid explicitly. The motion of the polymer is simulated by 3D Langevin dynamics technique by modeling the polymer as a worm-like-chain, while the hydrodynamic interactions are incorporated by the lattice Boltzmann equation. We report the simulation results for three different lengths of the nanopore. The translocation time increases with the pore length even though the electrophoretic force on the polymer is the same irrespective of the pore length. This is attributed to the fact that the translocation velocity of each bead inside the nanopore decreases with the pore length due to the increased fluid resistance force caused by the increase in the straightened portion of the polymer. We confirmed this using a theoretical formula.

Electronic Safety Resource Tools -- Supporting Hydrogen and Fuel Cell Commercialization

Energy Technology Data Exchange (ETDEWEB)

Barilo, Nick F.

2014-09-29

The Pacific Northwest National Laboratory (PNNL) Hydrogen Safety Program conducted a planning session in Los Angeles, CA on April 1, 2014 to consider what electronic safety tools would benefit the next phase of hydrogen and fuel cell commercialization. A diverse, 20-person team led by an experienced facilitator considered the question as it applied to the eight most relevant user groups. The results and subsequent evaluation activities revealed several possible resource tools that could greatly benefit users. The tool identified as having the greatest potential for impact is a hydrogen safety portal, which can be the central location for integrating and disseminating safety information (including most of the tools identified in this report). Such a tool can provide credible and reliable information from a trustworthy source. Other impactful tools identified include a codes and standards wizard to guide users through a series of questions relating to application and specific features of the requirements; a scenario-based virtual reality training for first responders; peer networking tools to bring users from focused groups together to discuss and collaborate on hydrogen safety issues; and a focused tool for training inspectors. Table ES.1 provides results of the planning session, including proposed new tools and changes to existing tools.

Novel Poly[(R-3-Hydroxybutyrate]-Producing Bacterium Isolated from a Bolivian Hypersaline Lake

Directory of Open Access Journals (Sweden)

María Soledad Marqués-Calvo

2013-01-01

Full Text Available Poly[(R-3-hydroxybutyrate] (PHB constitutes a biopolymer synthesized from renewable resources by various microorganisms. This work focuses on finding a new PHB-producing bacterium capable of growing in conventional media used for industrial biopolymer production, its taxonomical identification, and characterization of its biopolymer. Thus, a bacterial isolation process was carried out from environmental samples of water and mud. Among the isolates, strain S29 was selected and used in a fed-batch fermentation to generate a biopolymer. This biopolymer was recovered and identified as PHB homopolymer. Surprisingly, it featured several fractions of different molecular masses, and thermal properties unusual for PHB. Hence, the microorganism S29, genetically identified as a new strain of Bacillus megaterium, proved to be interesting not only due to its growth and PHB accumulation kinetics under the investigated cultivation conditions, but also due to the thermal properties of the produced PHB.

pH-induced contrast in viscoelasticity imaging of biopolymers

International Nuclear Information System (INIS)

Yapp, R D; Insana, M F

2009-01-01

Understanding contrast mechanisms and identifying discriminating features is at the heart of diagnostic imaging development. This paper focuses on how pH influences the viscoelastic properties of biopolymers to better understand the effects of extracellular pH on breast tumour elasticity imaging. Extracellular pH is known to decrease as much as 1 pH unit in breast tumours, thus creating a dangerous environment that increases cellular mutatation rates and therapeutic resistance. We used a gelatin hydrogel phantom to isolate the effects of pH on a polymer network with similarities to the extracellular matrix in breast stroma. Using compressive unconfined creep and stress relaxation measurements, we systematically measured the viscoelastic features sensitive to pH by way of time-domain models and complex modulus analysis. These results are used to determine the sensitivity of quasi-static ultrasonic elasticity imaging to pH. We found a strong elastic response of the polymer network to pH, such that the matrix stiffness decreases as pH was reduced; however, the viscous response of the medium to pH was negligible. While physiological features of breast stroma such as proteoglycans and vascular networks are not included in our hydrogel model, observations in this study provide insight into viscoelastic features specific to pH changes in the collagenous stromal network. These observations suggest that the large contrast common in breast tumours with desmoplasia may be reduced under acidic conditions, and that viscoelastic features are unlikely to improve discriminability.

EFFECTIVE ELECTRONIC TUTORIAL

Directory of Open Access Journals (Sweden)

Andrei A. Fedoseev

2014-01-01

Full Text Available The article analyzes effective electronic tutorials creation and application based on the theory of pedagogy. Herewith the issues of necessary electronic tutorial functional, ways of the educational process organization with the use of information and communication technologies and the logistics of electronic educational resources are touched upon. 

Gold and palladium adsorption from leached electronic scrap using ordered mesoporous carbon nanoscaffolds

Energy Technology Data Exchange (ETDEWEB)

McDowell, Rocklan; Dutech, Guy

2014-09-01

Ordered mesoporous carbon (OMC) nanoscaffolds are engineered agglomerates of carbon nanotubes held together by small carbon nanofibers with uniform pore sizes, high pore volume, and high channel permeability. These materials exhibit very high affinity for the adsorption of gold from aqueous acidic mixtures. The efficiency of gold recovery is comparable to those typically accomplished using biopolymer-based adsorbents. The adsorption efficiency for other precious metals such as palladium and platinum is lower. Studies on the precious metal (Au, Pd) adsorption on OMC materials from actual liquors of leached electronics will be presented. Adsorption properties will be compared for several different sorbents used for the recovery of precious metals. The leach liquor compositions for three different types of electronic scrap materials (personal computer board, cell phone and tv input/output board) will be presented. The sorption efficiencies for Au, Pd, together with a spectrum of competing and non-competing metals, from such leach mixtures will be compared.

Gold and palladium adsorption from leached electronic scrap using ordered mesoporous carbon nanoscaffolds

International Nuclear Information System (INIS)

McDowell, Rocklan; Dutech, Guy

2014-01-01

Ordered mesoporous carbon (OMC) nanoscaffolds are engineered agglomerates of carbon nanotubes held together by small carbon nanofibers with uniform pore sizes, high pore volume, and high channel permeability. These materials exhibit very high affinity for the adsorption of gold from aqueous acidic mixtures. The efficiency of gold recovery is comparable to those typically accomplished using biopolymer-based adsorbents. The adsorption efficiency for other precious metals such as palladium and platinum is lower. Studies on the precious metal (Au, Pd) adsorption on OMC materials from actual liquors of leached electronics will be presented. Adsorption properties will be compared for several different sorbents used for the recovery of precious metals. The leach liquor compositions for three different types of electronic scrap materials (personal computer board, cell phone and tv input/output board) will be presented. The sorption efficiencies for Au, Pd, together with a spectrum of competing and non-competing metals, from such leach mixtures will be compared.

Use of gamma-irradiation technology in the manufacture of biopolymer-based packaging films for shelf-stable foods

International Nuclear Information System (INIS)

Parra, Duclerc F.; Rodrigues, Juliana A.F.R.; Lugao, Ademar B.

2005-01-01

Gamma irradiation is an alternative method for the manufacture of sterilized packaging with increased storage stability and microbiological safety. Biopolymer-based packaging films are a potential solution to many environmental problems that have emerged from the production and accumulation of significant amounts of synthetic polymeric waste. This work was undertaken to verify the effectiveness of low-dose gamma-irradiation in obtaining biopolymer-based packaging films for shelf-stable foods. PHB polyester poly(3-hydroxybutyrate) is an interesting biodegradable polymer that has been intensely investigated as cast and sheet films, with applications in the food industry and medicine. The films obtained are, however, typically brittle, and many scientists have attempted to reduce this brittleness by blending PHB with other polymers. In the present work, PHB was blended with PEG (polyethyleneglycol) to obtain films by the casting method that were then irradiated at a dose rate of 5.72 kGy/h with a 60 Co source. Samples were melted at 200 deg. C and quenched to 0 deg. C in order to evaluate film crystallinity levels by differential scanning calorimetry (DSC). DSC analyses were performed with the samples (10 mg) under N 2 atmosphere, heating from -50 to 200 deg. C (10 deg. C min -1 ), cooling from 200 to -50 deg. C (10 deg. C min -1 ); and heating from -50 to 200 deg. C (10 deg. C min -1 ). The thermal and mechanical resistances of the films after irradiation at low doses (5, 10, 20 kGy) are discussed. Water vapour transmission decreased with increasing irradiation dose, indicating that the films' performance as water vapour barrier had improved. Critical loss of the mechanical properties was observed at 40 kGy

Preparation of Nano-Scale Biopolymer Extracted from Coconut Residue and Its Performance as Drag Reducing Agent (DRA

Directory of Open Access Journals (Sweden)

Hasan Muhammad Luqman Bin

2017-01-01

Full Text Available Drag or frictional force is defined as force that acts opposite to the object’s relative motion through a fluid which then will cause frictional pressure loss in the pipeline. Drag Reducing Agent (DRA is used to solve this issue and most of the DRAs are synthetic polymers but has some environmental issues. Therefore for this study, biopolymer known as Coconut Residue (CR is selected as the candidate to replace synthetic polymers DRA. The objective of this study is to evaluate the effectiveness of Nano-scale biopolymer DRA on the application of water injection system. Carboxymethyl cellulose (CMC is extracted by synthesizing the cellulose extracted from CR under the alkali-catalyzed reaction using monochloroacetic acid. The synthesize process is held in controlled condition whereby the concentration of NaOH is kept at 60%wt, 60 °C temperature and the reaction time is 4 hours. For every 25 g of dried CR used, the mass of synthesized CMC yield is at an average of 23.8 g. The synthesized CMC is then grinded in controlled parameters using the ball milling machine to get the Nano-scale size. The particle size obtained from this is 43.32 Nm which is in range of Nano size. This study proved that Nano-size CMC has higher percentage of drag reduction (%DR and flow increase (%FI if compared to normal-size CMC when tested in high and low flow rate; 44% to 48% increase in %DR and %FI when tested in low flow rate, and 16% to 18% increase in %DR and %FI when tested in high flow rate. The success of this research shows that Nano-scale DRA can be considered to be used to have better performance in reducing drag.

Use of gamma-irradiation technology in the manufacture of biopolymer-based packaging films for shelf-stable foods

Science.gov (United States)

Parra, Duclerc F.; Rodrigues, Juliana A. F. R.; Lugão, Ademar B.

2005-07-01

Gamma irradiation is an alternative method for the manufacture of sterilized packaging with increased storage stability and microbiological safety. Biopolymer-based packaging films are a potential solution to many environmental problems that have emerged from the production and accumulation of significant amounts of synthetic polymeric waste. This work was undertaken to verify the effectiveness of low-dose gamma-irradiation in obtaining biopolymer-based packaging films for shelf-stable foods. PHB polyester poly(3-hydroxybutyrate) is an interesting biodegradable polymer that has been intensely investigated as cast and sheet films, with applications in the food industry and medicine. The films obtained are, however, typically brittle, and many scientists have attempted to reduce this brittleness by blending PHB with other polymers. In the present work, PHB was blended with PEG (polyethyleneglycol) to obtain films by the casting method that were then irradiated at a dose rate of 5.72 kGy/h with a 60Co source. Samples were melted at 200 °C and quenched to 0 °C in order to evaluate film crystallinity levels by differential scanning calorimetry (DSC). DSC analyses were performed with the samples (10 mg) under N2 atmosphere, heating from -50 to 200 °C (10 °C min-1), cooling from 200 to -50 °C (10 °C min-1); and heating from -50 to 200 °C (10 °C min-1). The thermal and mechanical resistances of the films after irradiation at low doses (5, 10, 20 kGy) are discussed. Water vapour transmission decreased with increasing irradiation dose, indicating that the films' performance as water vapour barrier had improved. Critical loss of the mechanical properties was observed at 40 kGy.

Investigation on the biomimetic influence of biopolymers on calcium phosphate precipitation-Part 1: Alginate

International Nuclear Information System (INIS)

Oliveira de Lima, Daniel; Gomes Aimoli, Cassiano; Beppu, Marisa Masumi

2009-01-01

The understanding of how macromocules act in precipitation of inorganic phases is the key knowledge that is needed to establish the foundation to mimic nature and produce materials with high mechanical modulus besides outstanding optical and thermal properties. This study investigated how addition of small amounts of alginate (7-70 ppm), that presents many carboxylic groups, affects phase distribution and morphology of calcium phosphates, obtained through precipitation and further submitted to calcination and sintering. The results lead to the conclusion that alginate action is dynamic, where alginate molecules act as templates to nucleation, and most of the biopolymer remains in solution even when all calcium phosphate has precipitated. However, despite the effect on phase composition being mainly related to the system's kinetics, alginate does present thermodynamic interaction with the precipitates. It is probable that it acts by reducing the free energy of nucleation, as in heterogeneous nucleation processes.

Renewable energy resources

DEFF Research Database (Denmark)

Ellabban, Omar S.; Abu-Rub, Haitham A.; Blaabjerg, Frede

2014-01-01

Electric energy security is essential, yet the high cost and limited sources of fossil fuels, in addition to the need to reduce greenhouse gasses emission, have made renewable resources attractive in world energy-based economies. The potential for renewable energy resources is enormous because...... they can, in principle, exponentially exceed the world's energy demand; therefore, these types of resources will have a significant share in the future global energy portfolio, much of which is now concentrating on advancing their pool of renewable energy resources. Accordingly, this paper presents how...... renewable energy resources are currently being used, scientific developments to improve their use, their future prospects, and their deployment. Additionally, the paper represents the impact of power electronics and smart grid technologies that can enable the proportionate share of renewable energy...

Preference and Use of Electronic Information and Resources by Blind/Visually Impaired in NCR Libraries in India

Directory of Open Access Journals (Sweden)

Shailendra Kumar

2013-06-01

Full Text Available This paper aims to determine the preference and use of electronic information and resources by blind/visually impaired users in the leading National Capital Region (NCR libraries of India. Survey methodology has been used as the basic research tool for data collection with the help of questionnaires. The 125 in total users surveyed in all the five libraries were selected randomly on the basis of willingness of the users with experience of working in digital environments to participate in the survey. The survey results were tabulated and analyzed with descriptive statistics methods using Excel software and 'Stata version 11'. The findings reveal that ICT have a positive impact in the lives of people with disabilities as it helps them to work independently and increases the level of confidence among them. The Internet is the most preferred medium of access to information among the majority of blind/visually impaired users. The 'Complexity of content available on the net' is found as the major challenge faced during Internet use by blind users of NCR libraries. 'Audio books on CDs/DVDs and DAISY books' are the most preferred electronic resources among the majority of blind/visually impaired users. This study will help the library professionals and organizations/institutions serving people with disabilities to develop effective library services for blind/visually impaired users in the digital environment on the basis of findings on information usage behavior in the study.

Carboxymethyl Carrageenan Based Biopolymer Electrolytes

International Nuclear Information System (INIS)

Mobarak, N.N.; Jumaah, F.N.; Ghani, M.A.; Abdullah, M.P.; Ahmad, A.

2015-01-01

data, which demonstrated that the ionic conductivity of the 20 wt.% LiNO 3 iota-based electrolytes was highly similar with the 30 wt.% LiNO 3 kappa-based electrolytes, with values of 5.85 × 10 −3 S cm −1 and 5.51 × 10 −3 S cm −1 , respectively. The lithium transference number for the carboxymethyl kappa carrageenan was higher than for the carboxymethyl iota carrageenan. Additionally, the carboxymethyl iota carrageenan and carboxymethyl kappa carrageenan films were electrochemically stable up to ∼3.0 and 3.1 V, respectively, which indicates that these solid biopolymer electrolytes are promising candidates for utilization in electrochemical devices

Library usage patterns in the electronic information environment. Electronic journals, Use studies, Libraries, Medical libraries

Directory of Open Access Journals (Sweden)

B. Franklin

2004-01-01

Full Text Available This paper examines the methodology and results from Web-based surveys of more than 15,000 networked electronic services users in the United States between July 1998 and June 2003 at four academic health sciences libraries and two large main campus libraries serving a variety of disciplines. A statistically valid methodology for administering simultaneous Web-based and print-based surveys using the random moments sampling technique is discussed and implemented. Results from the Web-based surveys showed that at the four academic health sciences libraries, there were approximately four remote networked electronic services users for each in-house user. This ratio was even higher for faculty, staff, and research fellows at the academic health sciences libraries, where more than five remote users for each in-house user were recorded. At the two main libraries, there were approximately 1.3 remote users for each in-house user of electronic information. Sponsored research (grant funded research accounted for approximately 32% of the networked electronic services activity at the health sciences libraries and 16% at the main campus libraries. Sponsored researchers at the health sciences libraries appeared to use networked electronic services most intensively from on-campus, but not from in the library. The purpose of use for networked electronic resources by patrons within the library is different from the purpose of use of those resources by patrons using the resources remotely. The implications of these results on how librarians reach decisions about networked electronic resources and services are discussed.

Electronic resources of the rare books and valuable editions department of the Central Scientific Library of the V.N. Karazin Kharkiv National University: open access for research

Directory of Open Access Journals (Sweden)

І. К. Журавльова

2014-12-01

Full Text Available The article describes tasks that electronic collections of rare books fulfill: broad access for readers to rare and valuable editions providing, preservation of ensuring of the original. On the example of the electronic collection of the Central Scientific Library of the V.N. Karazin Kharkiv National University – «eScriptorium: electronic archive of rare books and manuscripts for research and education» the possibility of the full-text resources of the valuable editions using is shown. The principles of creation, structure, chronological frameworks, directions of adding the documents to the archive are represented. The perspectives of the project development are outlined as well as examples of the digital libraries of the European countries and Ukraine are provided, the actual task of preserving the originals of the rare books of the country is raised, the innovative approaches to serving users with electronic resources are considered. The evidences of cooperation of the Central Scientific Library of the V.N. Karazin Kharkiv National University with the largest world digital libraries: World Digital Library and Europeana are provided.

Dynamic light scattering of nano-gels of xanthan gum biopolymer in colloidal dispersion

Directory of Open Access Journals (Sweden)

Abbas Rahdar

2016-09-01

Full Text Available The dynamical properties of nanogels of xanthan gum (XG with hydrodynamic radius controlled in a size range from 5 nm to 35 nm, were studied at the different XG concentrations in water/sodium bis-2-ethylhexyl-sulfosuccinate (AOT/decane reverse micelles (RMs vs. mass fraction of nano-droplet (MFD at W = 40, using dynamic light scattering (DLS. The diffusion study of nanometer-sized droplets by DLS technique indicated that enhancing concentration of the XG polysaccharide resulted in exchanging the attractive interaction between nano-gels to repulsive interaction, as the mass fraction of nano-droplets increased. The reorientation time (τr of water nanodroplets decreased with MFD for water-in-oil AOT micro-emulsion comprising high concentration (0.0000625 of XG. On the other hand, decreasing concentration of biopolymer led to increasing the rotational correlation time of water nanodroplets with MFD. In conclusion, a single relaxation curve was observed for AOT inverse microemulsions containing different XG concentrations. Furthermore, the interaction between nanogels was changed from attractive to repulsive versus concentration of XG in the AOT RMs.

Electronic tracking of human resource skills and knowledge, just in time training, manageable due diligence

Energy Technology Data Exchange (ETDEWEB)

Kolodziej, M.A. [Quick Test International Inc., (Canada). Canadian Technology Human Resource Board; Baker, O. [KeySpan Energy Canada, Calgary, AB (Canada)

2001-06-01

KeySpan Energy Canada is in the process of obtaining recognition of various occupational profiles including pipeline operators, inspectors, and field and plant operators from various certifying organizations. The process of allowing individuals to obtain certification is recognized by Canadian Technology Human Resources Board as a step towards national standards for technologists and technicians. Proven competency is a must for workers in todays oil industry in response to increasingly stringent government safety regulations, environmental concerns and high public scrutiny. Quick Test international Inc. has developed a management tool in collaboration with end users at KeySpan Energy Canada. It is an electronic, Internet based competency tool for tracking personal competencies and maintaining continued competency. Response to the tool has been favourable. 2 refs., 4 figs.

FS laser processing of bio-polymer thin films for studying cell-to-substrate specific response

Energy Technology Data Exchange (ETDEWEB)

Daskalova, A., E-mail: a_daskalova@code.bg [Institute of Electronics, Bulgarian Academy of Sciences, 72, Tsarigradsko Chaussee Blvd., 1784 Sofia (Bulgaria); Nathala, Chandra S.R. [Institute of General Physics, Vienna University of Technology, Wiedner Hauptstr. 8-10/134, A-1040 Wien (Austria); Spectra-Physics Vienna, Fernkorngasse 10, 1100 Wien (Austria); Kavatzikidou, P.; Ranella, A. [Institute for Electronic Structure and Lasers-FORTH, P.O. Box 1385, Vassilika Vouton, 711 10 Heraklion, Crete (Greece); Szoszkiewicz, R. [Faculty of Materials Science and Engineering, Warsaw University of Technology, 141 Woloska Str., 02-507 Warsaw, Poland (Poland); Husinsky, W. [Institute of General Physics, Vienna University of Technology, Wiedner Hauptstr. 8-10/134, A-1040 Wien (Austria); Fotakis, C. [Institute for Electronic Structure and Lasers-FORTH, P.O. Box 1385, Vassilika Vouton, 711 10 Heraklion, Crete (Greece)

2016-09-30

Highlights: • Systematic research in the field of fs laser interaction with biopolymers for application in tissue engineering. • Utilizing a new biopolymer blend of collagen/elastin material for studying the interaction process in the fs domain. • Obtaining of improved, circularly shaped, interconnected nanopores, with high reproducibility from collagen/elastin layer. • Observation of randomly arranged pattern outside modification zone due to formation of an impact wave over biofilm surface. • NIH/3T3 cell-interface interaction reveal a preferable cell migration on fs laser-modified surface array. - Abstract: The use of ultra-short pulses for nanoengineering of biomaterials opens up possibilities for biological, medical and tissue engineering applications. Structuring the surface of a biomaterial into arrays with micro- and nanoscale features and architectures, defines new roadmaps to innovative engineering of materials. Thin films of novel collagen/elastin composite and gelatin were irradiated by Ti:sapphire fs laser in air at central wavelength 800 nm, with pulse durations in the range of 30 fs. The size and shape as well as morphological forms occurring in the resulted areas of interaction were analyzed as a function of irradiation fluence and number of pulses by atomic force microscopy (AFM). The fs interaction regime allows generation of well defined micro porous surface arrays. In this study we examined a novel composite consisting of collagen and elastin in order to create a biodegradable matrix to serve as a biomimetic surface for cell attachment. Confocal microscopy images of modified zones reveal formation of surface fringe patterns with orientation direction alongside the area of interaction. Outside the crater rim a wave-like topography pattern is observed. Structured, on a nanometer scale, surface array is employed for cell-culture experiments for testing cell’s responses to substrate morphology. Mice fibroblasts migration was monitored

FS laser processing of bio-polymer thin films for studying cell-to-substrate specific response

International Nuclear Information System (INIS)

Daskalova, A.; Nathala, Chandra S.R.; Kavatzikidou, P.; Ranella, A.; Szoszkiewicz, R.; Husinsky, W.; Fotakis, C.

2016-01-01

Highlights: • Systematic research in the field of fs laser interaction with biopolymers for application in tissue engineering. • Utilizing a new biopolymer blend of collagen/elastin material for studying the interaction process in the fs domain. • Obtaining of improved, circularly shaped, interconnected nanopores, with high reproducibility from collagen/elastin layer. • Observation of randomly arranged pattern outside modification zone due to formation of an impact wave over biofilm surface. • NIH/3T3 cell-interface interaction reveal a preferable cell migration on fs laser-modified surface array. - Abstract: The use of ultra-short pulses for nanoengineering of biomaterials opens up possibilities for biological, medical and tissue engineering applications. Structuring the surface of a biomaterial into arrays with micro- and nanoscale features and architectures, defines new roadmaps to innovative engineering of materials. Thin films of novel collagen/elastin composite and gelatin were irradiated by Ti:sapphire fs laser in air at central wavelength 800 nm, with pulse durations in the range of 30 fs. The size and shape as well as morphological forms occurring in the resulted areas of interaction were analyzed as a function of irradiation fluence and number of pulses by atomic force microscopy (AFM). The fs interaction regime allows generation of well defined micro porous surface arrays. In this study we examined a novel composite consisting of collagen and elastin in order to create a biodegradable matrix to serve as a biomimetic surface for cell attachment. Confocal microscopy images of modified zones reveal formation of surface fringe patterns with orientation direction alongside the area of interaction. Outside the crater rim a wave-like topography pattern is observed. Structured, on a nanometer scale, surface array is employed for cell-culture experiments for testing cell’s responses to substrate morphology. Mice fibroblasts migration was monitored

Design of polymer-biopolymer-hydroxyapatite biomaterials for bone tissue engineering: Through molecular control of interfaces

Science.gov (United States)

Verma, Devendra

In this dissertation, novel biomaterials are designed for bone biomaterials and bone tissue engineering applications. Novel biomaterials of hydroxyapatite with synthetic and natural polymers have been fabricated using a combination of processing routes. Initially, we investigated hydroxyapatite-polycaprolactone-polyacrylic acid composites and observed that minimal interfacial interactions between polymer and mineral led to inadequate improvement in the mechanical properties. Bioactivity experiments on these composites showed that the presence of functional groups, such as carboxylate groups, influence bioactivity of the composites. We have developed and investigated composites of hydroxyapatite with chitosan and polygalacturonic acid (PgA). Chitosan and PgA are biocompatible, biodegradable, and also electrostatically complementary to each other. This strategy led to significant improvement in mechanical properties of new composites. The nanostructure analysis using atomic force microscopy revealed a multilevel organization in these composites. Enhancement in mechanical response was attributed to stronger interfaces due to strong electrostatic interaction between oppositely charged chitosan and PgA. Further analysis using the Rietveld method showed that biopolymers have marked impact on hydroxyapatite crystal growth and also on its crystal structure. Significant changes were observed in the lattice parameters of hydroxyapatite synthesized by following biomineralization method (organics mediated mineralization). For scaffold preparation, chitosan and PgA were mixed first, and then, nano-hydroxyapatite was added. Oppositely charged polyelectrolytes, such as chitosan and PgA, spontaneously form complex upon mixing. The poly-electrolyte complex exists as nano-sized particles. Chitosan/PgA scaffolds with and without hydroxyapatite were prepared by the freeze drying method. By controlling the rate of cooling and concentration, we have produced both fibrous and sheet

The Biomedical Resource Ontology (BRO) to enable resource discovery in clinical and translational research.

Science.gov (United States)

Tenenbaum, Jessica D; Whetzel, Patricia L; Anderson, Kent; Borromeo, Charles D; Dinov, Ivo D; Gabriel, Davera; Kirschner, Beth; Mirel, Barbara; Morris, Tim; Noy, Natasha; Nyulas, Csongor; Rubenson, David; Saxman, Paul R; Singh, Harpreet; Whelan, Nancy; Wright, Zach; Athey, Brian D; Becich, Michael J; Ginsburg, Geoffrey S; Musen, Mark A; Smith, Kevin A; Tarantal, Alice F; Rubin, Daniel L; Lyster, Peter

2011-02-01

The biomedical research community relies on a diverse set of resources, both within their own institutions and at other research centers. In addition, an increasing number of shared electronic resources have been developed. Without effective means to locate and query these resources, it is challenging, if not impossible, for investigators to be aware of the myriad resources available, or to effectively perform resource discovery when the need arises. In this paper, we describe the development and use of the Biomedical Resource Ontology (BRO) to enable semantic annotation and discovery of biomedical resources. We also describe the Resource Discovery System (RDS) which is a federated, inter-institutional pilot project that uses the BRO to facilitate resource discovery on the Internet. Through the RDS framework and its associated Biositemaps infrastructure, the BRO facilitates semantic search and discovery of biomedical resources, breaking down barriers and streamlining scientific research that will improve human health. Copyright © 2010 Elsevier Inc. All rights reserved.

Electronic Recruitment at CERN

CERN Multimedia

2004-01-01

The Human Resources Department switches to electronic recruitment. From now on whenever you are involved in a recruitment action you will receive an e-mail giving you access to a Web folder. Inside you will find a shortlist of applications drawn up by the Human Resources Department. This will allow you to consult the folder, at the same time as everyone else involved in the recruitment process, for the vacancy you are interested in. This new electronic recruitment system, known as e-RT, will be introduced in a presentation given at 10 a.m. on 11 February in the Main Auditorium. Implemented by AIS (Administrative Information Services) and the Human Resources Department, e-RT will cover vacancies open in all of CERN's recruitment programmes. The electronic application system was initially made available to technical students in July 2003. By December it was extended to summer students, fellows, associates and Local Staff. Geraldine Ballet from the Recruitment Service prefers e-RT to mountains of paper! The Hu...

Plastics disassembly versus bulk recycling: engineering design for end-of-life electronics resource recovery.

Science.gov (United States)

Rios, Pedro; Stuart, Julie Ann; Grant, Ed

2003-12-01

Annual plastic flows through the business and consumer electronics manufacturing supply chain include nearly 3 billion lb of high-value engineering plastics derived from petroleum. The recovery of resource value from this stream presents critical challenges in areas of materials identification and recycling process design that demand new green engineering technologies applied together with life cycle assessment and ecological supply chain analysis to create viable plastics-to-plastics supply cycles. The sustainable recovery of potentially high-value engineering plastics streams requires that recyclers either avoid mixing plastic parts or purify later by separating smaller plastic pieces created in volume reduction (shredding) steps. Identification and separation constitute significant barriers in the plastics-to-plastics recycling value proposition. In the present work, we develop a model that accepts randomly arriving electronic products to study scenarios by which a recycler might identify and separate high-value engineering plastics as well as metals. Using discrete eventsimulation,we compare current mixed plastics recovery with spectrochemical plastic resin identification and subsequent sorting. Our results show that limited disassembly with whole-part identification can produce substantial yields in separated streams of recovered engineering thermoplastics. We find that disassembly with identification does not constitute a bottleneck, but rather, with relatively few workers, can be configured to pull the process and thus decrease maximum staging space requirements.

An intelligent biopolymer gel with pendant L-proline methyl ester

International Nuclear Information System (INIS)

Yoshida, Masaru; Safranj, A.; Omichi, Hideki; Katakai, Ryoichi.

1995-01-01

Linear poly(acryloyl-L-proline methyl ester, A-ProOMe), obtained by radiation-induced polymerization of its monomer in ethanol, exhibits a lower critical solution temperature (LCST) at 14degC. A-ProOMe was copolymerized with a minor amount of 2-hydroxypropyl methacrylate (HPMA) or 2-hydroxyethyl methacrylate (HEMA), to obtain intelligent biopolymer gels for application in drug delivery systems. The poly(A-ProOMe/HPMA) gel was characterized by an initial rapid shrinkage at the surface in the swollen state, as resulting in formation of a rigid membrane barrier devoid of micropores. This gel is called a surface regulated matrix. In the case of poly(A-ProOMe/HEMA), no such a barrier formed, instead, the whole matrix shrunk without the disappearance of micropores. This gel is called a matrix pumping gel. Testosterone (T) was incorporated into the poly(A-ProOMe/HPMA) gel, and it was found that the daily dose of T released in vivo from this formulation remained constant at approximately 30 μg/day throughout an experimental period of 54 weeks. On the other hand, 9-β-D-arabinofuranosyladenine (Ara-A) was incorporated into the poly(A-ProOMe/HEMA) gel to evaluate the pulsatile drug release when cycled at 10 and 37degC. The in vitro release rate of Ara-A was found to be 11 ng/h at 10degC and 33 ng/h at 37degC. (author)

Modelling of proton and metal exchange in the alginate biopolymer.

Science.gov (United States)

De Stefano, Concetta; Gianguzza, Antonio; Piazzese, Daniela; Sammartano, Silvio

2005-10-01

Acid-base behaviour of a commercial sodium alginate extracted from brown seaweed (Macrocystis pyrifera) has been investigated at different ionic strengths (0.1titration calorimetric data were expressed as a function of the dissociation degree (alpha) using different models (Henderson-Hasselbalch modified, Högfeldt three parameters and linear equations). The dependence on ionic strength of the protonation constants was taken into account by a modified specific interaction theory model. Differences among different media were explained in terms of the interaction between polyanion and metal cations of the supporting electrolytes. Quantitative information on the proton-binding capacity, together with the stabilities of different species formed, is reported. Protonation thermodynamic parameters, at alpha=0.5, are log K H=3.686+/-0.005, DeltaG 0=-21.04+/-0.03 kJ mol(-1), DeltaH 0=4.8+/-0.2 kJ mol(-1) and TDeltaS 0=35.7+/-0.3 kJ mol(-1), at infinite dilution. Protonation enthalpies indicate that the main contribution to proton binding arises from the entropy term. A strict correlation between DeltaG and TDeltaS was found, TDeltaS=-9.5-1.73 DeltaG. Results are reported in light of building up a chemical complexation model of general validity to explain the binding ability of naturally occurring polycarboxylate polymers and biopolymers. Speciation profiles of alginate in the presence of sodium and magnesium ions, naturally occurring cations in natural waters, are also reported.

Merge of terminological resources

DEFF Research Database (Denmark)

Henriksen, Lina; Braasch, Anna

2012-01-01

In our globalized world, the amount of cross-national communication increases rapidly, which also calls for easy access to multi-lingual high quality terminological resources. Sharing of terminology resources is currently becoming common practice, and efficient strategies for integration...... – or merging – of terminology resources are strongly needed. This paper discusses prerequisites for successful merging with the focus on identification of candidate duplicates of a subject domain found in the resources to be merged, and it describes automatic merging strategies to be applied to such duplicates...... in electronic terminology resources. Further, some perspectives of manual, supplementary assessment methods supporting the automatic procedures are sketched. Our considerations are primarily based on experience gained in the IATE and EuroTermBank projects, as merging was a much discussed issue in both projects....

Complete electronics self-teaching guide with projects

CERN Document Server

Boysen, Earl

2012-01-01

An all-in-one resource on everything electronics-related! For almost 30 years, this book has been a classic text for electronics enthusiasts. Now completely updated for today's technology, this latest version combines concepts, self-tests, and hands-on projects to offer you a completely repackaged and revised resource. This unique self-teaching guide features easy-to-understand explanations that are presented in a user-friendly format to help you learn the essentials you need to work with electronic circuits. All you need is a general understanding of electronics concepts such as Oh

Natural additives and agricultural wastes in biopolymer formulations for food packaging

Science.gov (United States)

Valdés, Arantzazu; Mellinas, Ana Cristina; Ramos, Marina; Garrigós, María Carmen; Jiménez, Alfonso

2014-02-01

The main directions in food packaging research are targeted towards improvements in food quality and food safety. For this purpose, food packaging providing longer product shelf-life, as well as the monitoring of safety and quality based upon international standards, is desirable. New active packaging strategies represent a key area of development in new multifunctional materials where the use of natural additives and/or agricultural wastes is getting increasing interest. The development of new materials, and particularly innovative biopolymer formulations, can help to address these requirements and also with other packaging functions such as: food protection and preservation, marketing and smart communication to consumers. The use of biocomposites for active food packaging is one of the most studied approaches in the last years on materials in contact with food. Applications of these innovative biocomposites could help to provide new food packaging materials with improved mechanical, barrier, antioxidant and antimicrobial properties. From the food industry standpoint, concerns such as the safety and risk associated with these new additives, migration properties and possible human ingestion and regulations need to be considered. The latest innovations in the use of these innovative formulations to obtain biocomposites are reported in this review. Legislative issues related to the use of natural additives and agricultural wastes in food packaging systems are also discussed.

Natural additives and agricultural wastes in biopolymer formulations for food packaging.

Science.gov (United States)

Valdés, Arantzazu; Mellinas, Ana Cristina; Ramos, Marina; Garrigós, María Carmen; Jiménez, Alfonso

2014-01-01

The main directions in food packaging research are targeted toward improvements in food quality and food safety. For this purpose, food packaging providing longer product shelf-life, as well as the monitoring of safety and quality based upon international standards, is desirable. New active packaging strategies represent a key area of development in new multifunctional materials where the use of natural additives and/or agricultural wastes is getting increasing interest. The development of new materials, and particularly innovative biopolymer formulations, can help to address these requirements and also with other packaging functions such as: food protection and preservation, marketing and smart communication to consumers. The use of biocomposites for active food packaging is one of the most studied approaches in the last years on materials in contact with food. Applications of these innovative biocomposites could help to provide new food packaging materials with improved mechanical, barrier, antioxidant, and antimicrobial properties. From the food industry standpoint, concerns such as the safety and risk associated with these new additives, migration properties and possible human ingestion and regulations need to be considered. The latest innovations in the use of these innovative formulations to obtain biocomposites are reported in this review. Legislative issues related to the use of natural additives and agricultural wastes in food packaging systems are also discussed.

Natural additives and agricultural wastes in biopolymer formulations for food packaging

Directory of Open Access Journals (Sweden)

Arantzazu eValdés

2014-02-01

Full Text Available The main directions in food packaging research are targeted towards improvements in food quality and food safety. For this purpose, food packaging providing longer product shelf-life, as well as the monitoring of safety and quality based upon international standards, is desirable. New active packaging strategies represent a key area of development in new multifunctional materials where the use of natural additives and/or agricultural wastes is getting increasing interest. The development of new materials, and particularly innovative biopolymer formulations, can help to address these requirements and also with other packaging functions such as: food protection and preservation, marketing and smart communication to consumers. The use of biocomposites for active food packaging is one of the most studied approaches in the last years on materials in contact with food. Applications of these innovative biocomposites could help to provide new food packaging materials with improved mechanical, barrier, antioxidant and antimicrobial properties. From the food industry standpoint, concerns such as the safety and risk associated with these new additives, migration properties and possible human ingestion and regulations need to be considered. The latest innovations in the use of these innovative formulations to obtain biocomposites are reported in this review. Legislative issues related to the use of natural additives and agricultural wastes in food packaging systems are also discussed.

Oscillator clustering in a resource distribution chain

DEFF Research Database (Denmark)

Postnov, D.; Sosnovtseva, Olga; Mosekilde, Erik

2005-01-01

separate the inherent dynamics of the individual oscillator from the properties of the coupling network. Illustrated by examples from microbiological population dynamics, renal physiology, and electronic oscillator theory, we show how competition for primary resources in a resource distribution chain leads...

Nano-cellulose biopolymer based nano-biofilm biomaterial using plant biomass: An innovative plant biomaterial dataset

Directory of Open Access Journals (Sweden)

A.B.M. Sharif hossain

2018-04-01

Full Text Available The nano-cellulose derived nano-biofilm keeps a magnificent role in medical, biomedical, bioengineering and pharmaceutical industries. Plant biomaterial is naturally organic and biodegradable. This study has been highlighted as one of the strategy introducing biomass based nano-bioplastic (nanobiofilm to solve dependency on petroleum and environment pollution because of non-degradable plastic. The data study was carried out to investigate the nano-biopolymer (nanocellulose based nano-biofilm data from corn leaf biomass coming after bioprocess technology without chemicals. Corn leaf biomass was used to produce biodegradable nano-bioplastic for medical and biomedical and other industrial uses. Data on water absorption, odor, pH, cellulose content, shape and firmness, color coating and tensile strength test have been exhibited under standardization of ASTM (American standard for testing and materials. Moreover, the chemical elements of nanobiofilm like K+, CO3−−, Cl−, Na+ showed standard data using the EN (166. Keywords: Nanocellulose, Nanobiofilm, Nanobioplastic, Biodegradable, Corn leaf

Development of Biopolymer Composite Films Using a Microfluidization Technique for Carboxymethylcellulose and Apple Skin Particles

Directory of Open Access Journals (Sweden)

Inyoung Choi

2017-06-01

Full Text Available Biopolymer films based on apple skin powder (ASP and carboxymethylcellulose (CMC were developed with the addition of apple skin extract (ASE and tartaric acid (TA. ASP/CMC composite films were prepared by mixing CMC with ASP solution using a microfluidization technique to reduce particle size. Then, various concentrations of ASE and TA were incorporated into the film solution as an antioxidant and an antimicrobial agent, respectively. Fourier transform infrared (FTIR, optical, mechanical, water barrier, and solubility properties of the developed films were then evaluated to determine the effects of ASE and TA on physicochemical properties. The films were also analyzed for antioxidant effect on 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and antimicrobial activities against Listeria monocytogenes, Staphylococcus aureus, Salmonella enterica, and Shigella flexneri. From the results, the ASP/CMC film containing ASE and TA was revealed to enhance the mechanical, water barrier, and solubility properties. Moreover, it showed the additional antioxidant and antimicrobial properties for application as an active packaging film.

Power Electronics

DEFF Research Database (Denmark)

Iov, Florin; Ciobotaru, Mihai; Blaabjerg, Frede

2008-01-01

is to change the electrical power production sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. The other is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss the most...... emerging renewable energy sources, wind energy, which by means of power electronics are changing from being a minor energy source to be acting as an important power source in the energy system. Power electronics is the enabling technology and the presentation will cover the development in wind turbine...... technology from kW to MW, discuss which power electronic solutions are most feasible and used today....

Novel Proton Conducting Solid Bio-polymer Electrolytes Based on Carboxymethyl Cellulose Doped with Oleic Acid and Plasticized with Glycerol

Science.gov (United States)

Chai, M. N.; Isa, M. I. N.

2016-06-01

The plasticized solid bio-polymer electrolytes (SBEs) system has been formed by introducing glycerol (Gly) as the plasticizer into the carboxymethyl cellulose (CMC) doped with oleic acid (OA) via solution casting techniques. The ionic conductivity of the plasticized SBEs has been studied using Electrical Impedance Spectroscopy. The highest conductivity achieved is 1.64 × 10-4 S cm-1 for system containing 40 wt. % of glycerol. FTIR deconvolution technique had shown that the conductivity of CMC-OA-Gly SBEs is primarily influenced by the number density of mobile ions. Transference number measurement has shown that the cation diffusion coefficient and ionic mobility is higher than anion which proved the plasticized polymer system is a proton conductor.

The versatile biopolymer chitosan: potential sources, evaluation of extraction methods and applications.

Science.gov (United States)

Kaur, Surinder; Dhillon, Gurpreet Singh

2014-05-01

Among the biopolymers, chitin and its derivative chitosan (CTS) have been receiving increasing attention. Both are composed of randomly distributed β-(1-4)-linked d-glucosamine and N-acetyl glucosamine units. On commercial scale, CTS is mainly obtained from the crustacean shells. The chemical methods employed for extraction of CTS from crustacean shells are laden with many disadvantages. Waste fungal biomass represents a potential biological source of CTS, in fact with superior physico-chemical properties, such as high degree of deacetylation, low molecular weight, devoid of protein contamination and high bioactivity. Researchers around the globe are attempting to commercialize CTS production and extraction from fungal sources. Fungi are promising and environmentally benign source of CTS and they have the potential to completely replace crustacean-derived CTS. Waste fungal biomass resulting from various pharmaceutical and biotechnological industries is grown on inexpensive agro-industrial wastes and its by-products are a rich and inexpensive source of CTS. CTS is emerging as an important natural polymer having broad range of applications in different fields. In this context, the present review discusses the potential sources of CTS and their advantages and disadvantages. This review also deals with potential applications of CTS in different fields. Finally, the various attributes of CTS sought in different applications are discussed.

Current Status and New Perspectives on Chitin and Chitosan as Functional Biopolymers.

Science.gov (United States)

Philibert, Tuyishime; Lee, Byong H; Fabien, Nsanzabera

2017-04-01

The natural biopolymer chitin and its deacetylated product chitosan are found abundantly in nature as structural building blocks and are used in all sectors of human activities like materials science, nutrition, health care, and energy. Far from being fully recognized, these polymers are able to open opportunities for completely novel applications due to their exceptional properties which an economic value is intrinsically entrapped. On a commercial scale, chitosan is mainly obtained from crustacean shells rather than from the fungal and insect sources. Significant efforts have been devoted to commercialize chitosan extracted from fungal and insect sources to completely replace crustacean-derived chitosan. However, the traditional chitin extraction processes are laden with many disadvantages. The present review discusses the potential bioextraction of chitosan from fungal, insect, and crustacean as well as its superior physico-chemical properties. The different aspects of fungal, insects, and crustacean chitosan extraction methods and various parameters having an effect on the yield of chitin and chitosan are discussed in detail. In addition, this review also deals with essential attributes of chitosan for high value-added applications in different fields and highlighted new perspectives on the production of chitin and deacetylated chitosan from different sources with the concomitant reduction of the environmental impact.

Conductivity and transport studies of plasticized chitosan-based proton conducting biopolymer electrolytes

Science.gov (United States)

Shukur, M. F.; Yusof, Y. M.; Zawawi, S. M. M.; Illias, H. A.; Kadir, M. F. Z.

2013-11-01

This paper focuses on the conductivity and transport properties of chitosan-based solid biopolymer electrolytes containing ammonium thiocyanate (NH4SCN). The sample containing 40 wt% NH4SCN exhibited the highest conductivity value of (1.81 ± 0.50) × 10-4 S cm-1 at room temperature. Conductivity has increased to (1.51 ± 0.12) × 10-3 S cm-1 with the addition of 25 wt% glycerol. The temperature dependence of conductivity for both salted and plasticized systems obeyed the Arrhenius rule. The activation energy (Ea) was calculated for both systems and it is found that the sample with 40 wt% NH4SCN in the salted system obtained an Ea value of 0.148 eV and that for the sample containing 25 wt% glycerol in the plasticized system is 0.139 eV. From the Fourier transform infrared studies, carboxamide and amine bands shifted to lower wavenumbers, indicating that chitosan has interacted with NH4SCN salt. Changes in the C-O stretching vibration band intensity are observed at 1067 cm-1 with the addition of glycerol. The Rice and Roth model was used to explain the transport properties of the salted and plasticized systems.

Biomimetic Nanofibrillation in Two-Component Biopolymer Blends with Structural Analogs to Spider Silk

Science.gov (United States)

Xie, Lan; Xu, Huan; Li, Liang-Bin; Hsiao, Benjamin S.; Zhong, Gan-Ji; Li, Zhong-Ming

2016-10-01

Despite the enormous potential in bioinspired fabrication of high-strength structure by mimicking the spinning process of spider silk, currently accessible routes (e.g., microfluidic and electrospinning approaches) still have substantial function gaps in providing precision control over the nanofibrillar superstructure, crystalline morphology or molecular orientation. Here the concept of biomimetic nanofibrillation, by copying the spiders’ spinning principles, was conceived to build silk-mimicking hierarchies in two-phase biodegradable blends, strategically involving the stepwise integration of elongational shear and high-pressure shear. Phase separation confined on nanoscale, together with deformation of discrete phases and pre-alignment of polymer chains, was triggered in the elongational shear, conferring the readiness for direct nanofibrillation in the latter shearing stage. The orderly aligned nanofibrils, featuring an ultralow diameter of around 100 nm and the “rigid-soft” system crosslinked by nanocrystal domains like silk protein dopes, were secreted by fine nanochannels. The incorporation of multiscale silk-mimicking structures afforded exceptional combination of strength, ductility and toughness for the nanofibrillar polymer composites. The proposed spider spinning-mimicking strategy, offering the biomimetic function integration unattainable with current approaches, may prompt materials scientists to pursue biopolymer mimics of silk with high performance yet light weight.

Recovery of oil from oil-in-water emulsion using biopolymers by adsorptive method.

Science.gov (United States)

Elanchezhiyan, S Sd; Sivasurian, N; Meenakshi, Sankaran

2014-09-01

In the present study, it is aimed to identify, a low cost sorbent for the recovery of oil from oil-in-water emulsion using biopolymers such as chitin and chitosan. Chitin has the greater adsorption capacity than chitosan due to its hydrophobic nature. The characterizations of chitin and chitosan were done using FTIR, SEM, EDAX, XRD, TGA and DSC techniques. Under batch equilibrium mode, a systematic study was performed to optimize the various equilibrium parameters viz., contact time, pH, dosage, initial concentration of oil, and temperature. The adsorption process reached equilibrium at 40 min of contact time and the percentage removal of oil was found to be higher (90%) in the acidic medium. The Freundlich and Langmuir models were applied to describe the equilibrium isotherms and the isotherm constants were calculated. Thermodynamic parameters such as ΔG°, ΔH° and ΔS° were calculated to find out the nature of the sorption mechanism. The kinetic studies were investigated with reaction-based and diffusion-based models. The suitable mechanism for the removal of oil has been established. Copyright © 2014 Elsevier B.V. All rights reserved.

Electrons in water radiolysis

International Nuclear Information System (INIS)

Laverne, J.A.; Pimblott, S.M.

2006-01-01

The hydrated electron is the main reducing species produced in the radiolysis of water. Many studies have examined its reactivity using pulsed radiolysis techniques and competition kinetics. Data bases list hundreds of rate coefficients for reaction of the hydrated electron with substances ranging from inorganic ions like nitrate to biopolymers like DNA. Although the chemistry of the hydrated electron is often examined, its mechanism of formation and variation in yield are considerable less known, especially under extreme conditions such as in high temperature water or with heavy ion radiolysis. This work will examine various aspects of the radiation chemistry of the hydrated electron beginning with the generation of secondary electrons in primary energy loss events during the passage of ionizing radiation to the radiolytic yields of the hydrated electron produced by different types of radiation. Ion radiation is a 'white light source.' Energy losses range from the minimum excitation energy of the medium up to the kinematic maximum determined by the collision parameters. However, certain energy loss events are more probable than others. The dipole oscillator strength distributions of media essentially give the probability of energy loss events in collisions with no momentum transfer. Dipole oscillator distributions have been constructed from experimental data for a wide variety of materials including all the phases of water. Calculations using cross sections based on dipole oscillator distributions show that the most probable energy loss event in water is only about 20 eV with an average value closer to 60 eV. The preponderance of energy loss events of less than 100 eV means that many low energy electrons are formed by the passage of a single ion. Low energy electrons have short mean free paths and they remain in the vicinity of the primary energy loss events. The spatial distribution of these low energy electrons defines the radial track structure of the incident

Variability of electron spin resonance (ESR) signal of γ -irradiated starches

International Nuclear Information System (INIS)

Silva, Gilberto D.; Rodrigues Junior, Orlando; Mastro, Nelida L. del

2017-01-01

Food preservation is one of the practical applications of radiation processing of materials. Starch is an abundant and cheap nutritious biopolymer and also is the material for appropriate food systems and for technical industries. Starch granules are partially crystalline structures composed mainly of two types of starch: amylose, an essentially linear polymer, and amylopectin, with 3-44% of branch points. Electron spin resonance (ESR) spectroscopy is a very powerful and sensitive method for the characterization of the electronic structures of materials with unpaired electrons. The aim of the present work was to monitor the disappearance of the short life and long-life free radicals formed during γ-irradiation of 3 different starches. Corn, potato and fermented cassava starches were irradiated in a "6"0Co source Gammacell 220 with 20 kGy, dose rate around 1 kGy h"-"1. EPR spectra were obtained at room temperature using a Bruker EMX plus model, X band equipment. The main type of ESR signal from irradiated starch is a singlet with a g-value of about 2.0. The fading of ESR signals was followed for 350 hours, and presents differences among the different starch type reflecting differences in molecular arrangements of starch crystalline and amorphous fractions, although ESR spectra seemed to be common for all starches. (author)

Variability of electron spin resonance (ESR) signal of γ -irradiated starches

Energy Technology Data Exchange (ETDEWEB)

Silva, Gilberto D.; Rodrigues Junior, Orlando; Mastro, Nelida L. del, E-mail: nlmastro@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2017-11-01

Food preservation is one of the practical applications of radiation processing of materials. Starch is an abundant and cheap nutritious biopolymer and also is the material for appropriate food systems and for technical industries. Starch granules are partially crystalline structures composed mainly of two types of starch: amylose, an essentially linear polymer, and amylopectin, with 3-44% of branch points. Electron spin resonance (ESR) spectroscopy is a very powerful and sensitive method for the characterization of the electronic structures of materials with unpaired electrons. The aim of the present work was to monitor the disappearance of the short life and long-life free radicals formed during γ-irradiation of 3 different starches. Corn, potato and fermented cassava starches were irradiated in a {sup 60}Co source Gammacell 220 with 20 kGy, dose rate around 1 kGy h{sup -1}. EPR spectra were obtained at room temperature using a Bruker EMX plus model, X band equipment. The main type of ESR signal from irradiated starch is a singlet with a g-value of about 2.0. The fading of ESR signals was followed for 350 hours, and presents differences among the different starch type reflecting differences in molecular arrangements of starch crystalline and amorphous fractions, although ESR spectra seemed to be common for all starches. (author)

Electronic conferencing for continuing medical education: a resource survey.

Science.gov (United States)

Sternberg, R J

1986-10-01

The use of electronic technologies to link participants for education conferences is an option for providers of Continuing Medical Education. In order to profile the kinds of electronic networks currently offering audio- or videoteleconferences for physician audiences, a survey was done during late 1985. The information collected included range of services, fees, and geographic areas served. The results show a broad diversity of providers providing both interactive and didactic programming to both physicians and other health care professionals.

Advanced Coatings from Natural-Based Polymers for Metals

National Research Council Canada - National Science Library

Sugama, Toshifumi

2000-01-01

... natural polysaccharide biopolymers originating from pectin, starch, and chitosan as renewable agricultural and marine resources, and on assessing their potential as the corrosion-preventing water-based...

Radioprotective influence on mice DNA of biopolymer complexes from tinder Fomes Fomentarius under ionizing radiation in small doses

International Nuclear Information System (INIS)

Senyuk, O.F.; Koval'ov, O.V.; Palamar, L.A.; Krul', M.Yi.; Gorovij, L.F.

2014-01-01

The effects of similar doses of the values of common external irradiation (0,19 Gy/4 hours and 0,24 Gy/6 months) at single-strand DNA breaks and the level of the hydrogen bonds in this molecule in different cell types (lymphocytes, hepatocytes and splenocytes) linear mice CC57W/mv are discussed. Mice were exposed to γ-fields produced by h ot - particles of emergency 4-th Chernobyl Unit containing the same radionuclides in the proportions. The possibility of leveling the radiation effects using complex biopolymers from Fomes Fomentarius was shown. The ability of melanin-glucan complex to directly counteract the fragmentation of DNA in a model system with lambda phage this macromolecule oxidation products of benzidine and neutralize mutagenic effect in Salmonella typhimurium strains in the classical Ames test was studied

Utilization of bio-resources by low energy electron beam

International Nuclear Information System (INIS)

Kume, Tamikazu

2003-01-01

Utilization of bio-resources by radiation has been investigated for recycling the natural resources and reducing the environmental pollution. Polysaccharides such as chitosan and sodium alginate were easily degraded by irradiation and induced various kinds of biological activities, i.g. anti-microbial activity, promotion of plant growth, suppression of heavy metal stress, phytoalexins induction. Radiation degraded chitosan was effective to enhance the growth of plants in tissue culture. It was demonstrated that the liquid sample irradiation system using low energy EB was effective for the preparation of degraded polysaccharides. Methylcellulose (MC) can be crosslinked under certain radiation condition as same as carboxymethylcellulose (CMC) and produced the biodegradable hydrogel for medical and agricultural use. Treatment of soybean seeds by low energy EB enhanced the growth and the number of rhizobia on the root. (author)

Adaptation of mathematical educational content in e-learning resources

Directory of Open Access Journals (Sweden)

Yuliya V. Vainshtein

2017-01-01

Full Text Available Modern trends in the world electronic educational system development determine the necessity of adaptive learning intellectual environments and resources’ development and implementation. An upcoming trend in improvement the quality of studying mathematical disciplines is the development and application of adaptive electronic educational resources. However, the development and application experience of adaptive technologies in higher education is currently extremely limited and does not imply the usage flexibility. Adaptive educational resources in the electronic environment are electronic educational resources that provide the student with a personal educational space, filled with educational content that “adapts” to the individual characteristics of the students and provides them with the necessary information.This article focuses on the mathematical educational content adaptation algorithms development and their implementation in the e-learning system. The peculiarity of the proposed algorithms is the possibility of their application and distribution for adaptive e-learning resources construction. The novelty of the proposed approach is the three-step content organization of the adaptive algorithms for the educational content: “introductory adaptation of content”, “the current adaptation of content”, “estimative and a corrective adaptation”. For each stage of the proposed system, mathematical algorithms for educational content adaptation in adaptive e-learning resources are presented.Due to the high level of abstraction and complexity perception of mathematical disciplines, educational content is represented in the various editions of presentation that correspond to the levels of assimilation of the course material. Adaptation consists in the selection of the optimal edition of the material that best matches the individual characteristics of the student. The introduction of a three-step content organization of the adaptive

Conductivity and transport studies of plasticized chitosan-based proton conducting biopolymer electrolytes

International Nuclear Information System (INIS)

Shukur, M F; Yusof, Y M; Zawawi, S M M; Illias, H A; Kadir, M F Z

2013-01-01

This paper focuses on the conductivity and transport properties of chitosan-based solid biopolymer electrolytes containing ammonium thiocyanate (NH 4 SCN). The sample containing 40 wt% NH 4 SCN exhibited the highest conductivity value of (1.81 ± 0.50) × 10 −4  S cm −1 at room temperature. Conductivity has increased to (1.51 ± 0.12) × 10 −3  S cm −1 with the addition of 25 wt% glycerol. The temperature dependence of conductivity for both salted and plasticized systems obeyed the Arrhenius rule. The activation energy (E a ) was calculated for both systems and it is found that the sample with 40 wt% NH 4 SCN in the salted system obtained an E a value of 0.148 eV and that for the sample containing 25 wt% glycerol in the plasticized system is 0.139 eV. From the Fourier transform infrared studies, carboxamide and amine bands shifted to lower wavenumbers, indicating that chitosan has interacted with NH 4 SCN salt. Changes in the C–O stretching vibration band intensity are observed at 1067 cm −1 with the addition of glycerol. The Rice and Roth model was used to explain the transport properties of the salted and plasticized systems. (paper)

Internet and Electronic Information Management

Science.gov (United States)

2004-12-01

centers to form consortia and share electronic information sources. Although traditional resource sharing arrangements encouraged competition rather...outside world, through public relations and through marketing information products or services, to its own competitive advantage (Davenport 1997: 193-217... electronic information sources are a challenge for electronic information managers. Libraries and information centers are no longer “the only game in town

Effect of high-pressure food processing on the physical properties of synthetic and biopolymer films.

Science.gov (United States)

Galotto, M J; Ulloa, P A; Guarda, A; Gavara, R; Miltz, J

2009-08-01

The effect of high-pressure processing on 2 plastic food packaging films, a biopolymer (PLASiOx/PLA) and a synthetic polymer (PET-AlOx), was studied. Samples in direct contact with olive oil, as a fatty food simulant, and distilled water, as an aqueous simulant, were subjected to a pressure of 500MPa for 15 min at 50 degrees C. The mechanical, thermal, and gas barrier properties of both films were evaluated after the high-pressure processing (HPP) and compared to control samples that have not undergone this treatment. Significant changes in all properties were observed in both films after the HPP treatment and in contact with the food simulants. In both films an induced crystallization was noticed. In the PLASiOx/PLA film the changes were larger when in contact with water that probably acted as a plasticizer. In the PET-AlOx film the changes in properties were attributed to the formation of pinholes and cracks during the HPP treatment. In this film, most of the properties changed more in the presence of oil as the food simulant.

Single molecule force measurements delineate salt, pH and surface effects on biopolymer adhesion

International Nuclear Information System (INIS)

Pirzer, T; Geisler, M; Hugel, T; Scheibel, T

2009-01-01

In this paper we probe the influence of surface properties, pH and salt on the adhesion of recombinant spider silk proteins onto solid substrates with single molecule force spectroscopy. A single engineered spider silk protein (monomeric C 16 or dimeric (QAQ) 8 NR3) is covalently bound with one end to an AFM tip, which assures long-time measurements for hours with one and the same protein. The tip with the protein is brought into contact with various substrates at various buffer conditions and then retracted to desorb the protein. We observe a linear dependence of the adhesion force on the concentration of three selected salts (NaCl, NaH 2 PO 4 and NaI) and a Hofmeister series both for anions and cations. As expected, the more hydrophobic C 16 shows a higher adhesion force than (QAQ) 8 NR3, and the adhesion force rises with the hydrophobicity of the substrate. Unexpected is the magnitude of the dependences—we never observe a change of more than 30%, suggesting a surprisingly well-regulated balance between dispersive forces, water-structure-induced forces as well as co-solute-induced forces in biopolymer adhesion

Single molecule force measurements delineate salt, pH and surface effects on biopolymer adhesion

Science.gov (United States)

Pirzer, T.; Geisler, M.; Scheibel, T.; Hugel, T.

2009-06-01

In this paper we probe the influence of surface properties, pH and salt on the adhesion of recombinant spider silk proteins onto solid substrates with single molecule force spectroscopy. A single engineered spider silk protein (monomeric C16 or dimeric (QAQ)8NR3) is covalently bound with one end to an AFM tip, which assures long-time measurements for hours with one and the same protein. The tip with the protein is brought into contact with various substrates at various buffer conditions and then retracted to desorb the protein. We observe a linear dependence of the adhesion force on the concentration of three selected salts (NaCl, NaH2PO4 and NaI) and a Hofmeister series both for anions and cations. As expected, the more hydrophobic C16 shows a higher adhesion force than (QAQ)8NR3, and the adhesion force rises with the hydrophobicity of the substrate. Unexpected is the magnitude of the dependences—we never observe a change of more than 30%, suggesting a surprisingly well-regulated balance between dispersive forces, water-structure-induced forces as well as co-solute-induced forces in biopolymer adhesion.

Electronic Information Access and Utilization by Makerere University Students in Uganda

Directory of Open Access Journals (Sweden)

Elisam Magara

2008-09-01

Full Text Available Objectives – The objectives of this study were to establish the level of computer utilization skills of Makerere University (Uganda Library and Information Science (LIS students; to determine the use of electronic information resources by LIS students; to determine the attitudes of LIS students towards electronic information resources; and to establish the problems faced by LIS students in accessing electronic information resources.Methods – A questionnaire survey was used for data collection.Results – The majority of Library and Information Science students at Makerere University depend on university computers for their work, and very few of them access the library’s e-resources. The few who access e-resources are self-taught. The majority of students surveyed were unaware of Emerald and EBSCO databases relevant to Library and Information Science students, and they found accessing eresources time-consuming. Conclusion – The study concluded that a concerted effort is needed by both LIS lecturers and university librarians in promoting use of the library’s electronic resources.

Dynamic models for distributed generation resources

Energy Technology Data Exchange (ETDEWEB)

Morched, A.S. [BPR Energie, Sherbrooke, PQ (Canada)

2010-07-01

Distributed resources can impact the performance of host power systems during both normal and abnormal system conditions. This PowerPoint presentation discussed the use of dynamic models for identifying potential interaction problems between interconnected systems. The models were designed to simulate steady state behaviour as well as transient responses to system disturbances. The distributed generators included directly coupled and electronically coupled generators. The directly coupled generator was driven by wind turbines. Simplified models of grid-side inverters, electronically coupled wind generators and doubly-fed induction generators (DFIGs) were presented. The responses of DFIGs to wind variations were evaluated. Synchronous machine and electronically coupled generator responses were compared. The system model components included load models, generators, protection systems, and system equivalents. Frequency responses to islanding events were reviewed. The study demonstrated that accurate simulations are needed to predict the impact of distributed generation resources on the performance of host systems. Advances in distributed generation technology have outpaced the development of models needed for integration studies. tabs., figs.

Radioprotective influence on mice DNA of biopolymer complexes from tinder Fomes Fomentarius under ionizing radiation in small doses

Directory of Open Access Journals (Sweden)

O. F. Seniuk

2014-03-01

Full Text Available The effects of similar doses of the values of common external irradiation (0,19 Gy/4hours and 0,24 Gy/6 months at single-strand DNA breaks and the level of the hydrogen bonds in this molecule in different cell types (lymphocytes, hepatocytes and splenocytes linear mice CC57W/mv are discussed. Mice were exposed to γ-fields produced by “hot” particles of emergency 4-th Chernobyl Unit containing the same radionuclides in the proportions. The possibility of leveling the radiation effects using complex biopolymers from Fomes fomentarius was shown. The ability of melanin-glucan complex to directly counteract the fragmentation of DNA in a model system with lambda phage this macromolecule oxidation products of benzidine and neutralize mutagenic effect in Salmonella typhimurium strains in the classical Ames test was studied.

Availability of Electronic Resources for Service Provision in ...

African Journals Online (AJOL)

The study also revealed that majority of the University libraries have adequate basic infrastructure for effective electronic information services. ... acquired by the library are put into maximal use by the library clientele, thereby ensuring the achievement of the library's objective which is satisfying the users, information needs.

Emotional Intelligence Research within Human Resource Development Scholarship

Science.gov (United States)

Farnia, Forouzan; Nafukho, Fredrick Muyia

2016-01-01

Purpose: The purpose of this study is to review and synthesize pertinent emotional intelligence (EI) research within the human resource development (HRD) scholarship. Design/methodology/approach: An integrative review of literature was conducted and multiple electronic databases were searched to find the relevant resources. Using the content…

To get or not to get: the KAUST library e-resources acquisition experience

KAUST Repository

Ramli, Rindra M.

2014-06-01

In the challenging times of budget cuts and reviews, libraries are faced with issues, among others, such as justifying acquisition, negotiating deals and reviewing current subscriptions (pertaining to electronic resources). With the rapid increase in growth of electronic resources, libraries have to continuously assess their acquisition models and policies to constantly ensure that they are balancing their budget and users’ needs as well. This paper highlights the role played by Technical and IT department of King Abdullah University of Science and Technology (KAUST) library (Saudi Arabia) in acquiring the electronic resources (electronic books, electronic journals, databases, image and reference) for the community. It will describe the processes during the early days when KAUST library was inaugurated; how electronic resources were acquired and what went through during those days. The paper will elaborate further how the acquisition model has evolved and the various important roles played by the library staff in ensuring that acquisitions/subscriptions are justified, within the budget and provides ROI for the library. King Abdullah University is a graduate research university which opened in September 2009 with its first cohort of 800 graduate students (25% female) taught by 100 faculties. The focus of study and research in the university are: Mathematics and Computer Science, Physical Sciences and Life Sciences. The university library started with 10 staff. The library has a “state-of-the-art learning and information resource center supporting graduate education and advanced scientific research” (KAUST, 2010).

Utilisation of Online Resources among Undergraduates in Nigerian ...

African Journals Online (AJOL)

Electronic book (e-book) was mostly utilized as against Ejournals and E-thesis, while mobile phones and cybercafés remain the channels used in accessing online resources. it was discovered that incessant power supply, slow Internet connectivity and lack of time to access the information resources are constraints to ...

Automotive electronics design fundamentals

CERN Document Server

Zaman, Najamuz

2015-01-01

This book explains the topology behind automotive electronics architectures and examines how they can be profoundly augmented with embedded controllers. These controllers serve as the core building blocks of today’s vehicle electronics. Rather than simply teaching electrical basics, this unique resource focuses on the fundamental concepts of vehicle electronics architecture, and details the wide variety of Electronic Control Modules (ECMs) that enable the increasingly sophisticated "bells & whistles" of modern designs.  A must-have for automotive design engineers, technicians working in automotive electronics repair centers and students taking automotive electronics courses, this guide bridges the gap between academic instruction and industry practice with clear, concise advice on how to design and optimize automotive electronics with embedded controllers.

Gaseous Electronics Tables, Atoms, and Molecules

CERN Document Server

Raju, Gorur Govinda

2011-01-01

With the constant emergence of new research and application possibilities, gaseous electronics is more important than ever in disciplines including engineering (electrical, power, mechanical, electronics, and environmental), physics, and electronics. The first resource of its kind, Gaseous Electronics: Tables, Atoms, and Molecules fulfills the author's vision of a stand-alone reference to condense 100 years of research on electron-neutral collision data into one easily searchable volume. It presents most--if not all--of the properly classified experimental results that scientists, researchers,

The Frustrated Nerds Project--Resources for Systems Administrators in Higher Education: A Resource Webliography

Science.gov (United States)

Henninger, Jessamyn; Aber, Susan Ward

2010-01-01

Systems Architects and Information Technology administrators working in higher education help faculty, staff, and student computer users. Yet, who helps them? What resources do these professionals value? A case study was conducted using purposeful sampling and data collection through electronic interview to gather the preferred information-seeking…

Long-Range Electron Effects upon Irradiation of Molecular Solids and Polymers

International Nuclear Information System (INIS)

Feldman, V.I.

2006-01-01

Long-range electron effects are responsible for specific localization and selectivity of the radiation-induced chemical transformations occurring in molecular solids and polymers, when the classic diffusion mobility is essentially restricted. In particullar, understanding of the effects of this kind may be of key significance for establishing new ways to control the radiation sensitivity of macromolecules and organized polymeric systems, nanomaterials and biopolymers. This talk will present an overview of model studies of the long-range electron effects with the characteristic scale from several angstroms to ten nanometers. The following aspects of the problem will be analyzed: (1) Positive hole delocalization in ionized molecules. This phenomenon has been demonstrated experimentally and confirmed by quantum chemical calculations for a number of various-type molecules (alkanes, conjugated polyenes, bifunctional compounds). The effective delocalization length was found to be up to 2 nm (or even larger). The role of this effect in site-selective radiation chemistry will be discussed in the frame of concepts of distributed reactivity and 'switching' between delocalized and localized states. (2) Trap-to-trap positive hole and electron migration between isolated molecules or functional groups. The characteristic distance for this process was estimated to be 2 to 4 nm. Special impact will be made on the possible role of this process in selection of specific isomers or conformers upon irradiation of complex systems and macromolecules. (3) The effects of long-range scavenging of low-energy secondary electrons in polymers and organized polymeric systems. As revealed by model experiments, the radius of electron capture in solid polymers may be in the range of 1 to 10 nm. Possible implications of scavenging effects for controlling the radiation chemistry of polymers and organized polymeric systems will be considered

Human Resource Development in Hybrid Libraries

OpenAIRE

Prakasan, E. R.; Swarna, T.; Vijai Kumar, *

2000-01-01

This paper explores the human resources and development implications in hybrid libraries. Due to technological changes in libraries, which is a result of the proliferation of electronic resources, there has been a shift in workloads and workflow, requiring staff with different skills and educational backgrounds. Training of staff at all levels in information technology is the key to manage change, alleviate anxiety in the workplace and assure quality service in the libraries. Staff developmen...

Effective adsorption of oil droplets from oil-in-water emulsion using metal ions encapsulated biopolymers: Role of metal ions and their mechanism in oil removal.

Science.gov (United States)

Elanchezhiyan, S Sd; Prabhu, Subbaiah Muthu; Meenakshi, Sankaran

2018-06-01

Herein, synthesized and compared the three different kinds of hybrid bio-polymeric composites viz., lanthanum embedded chitosan/gelatin (La@CS-GEL), zirconium embedded chitosan/gelatin (Zr@CS-GEL) and cerium embedded chitosan/gelatin (Ce@CS-GEL) in terms of their oil uptake efficiency. The adsorption efficiency was studied under various optimized parameters like contact time, pH, dose, initial oil concentration and temperature. The oil adsorption capacity was found to be 91, 82 and 45% for La@CS-GEL, Zr@CS-GEL and Ce@CS-GEL composites respectively. The metals were used as a bridging material to connect both CS and GEL using the hydrophilic groups to enhance the oil recovery by hydrophobic interaction. Also, the introduction of metal ions on the surface of biopolymers would modify the oil/water properties which in turn, decrease the interfacial tension between oil and water phases. The mechanism of oil uptake was explained using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscope (SEM), energy dispersive X-ray (EDAX) and heat of combustion. The experimental data confirmed Langmuir isotherm as the best fit for oil adsorption process. Thermodynamic parameters such as standard free energy (ΔG°), standard enthalpy (ΔH°) and standard entropy (ΔS°) indicated that the oil adsorption was spontaneous and endothermic. The oil adsorption mechanism was established based on isotherm and thermodynamic models. Copyright © 2018 Elsevier B.V. All rights reserved.

Influence of biopolymers on the solubility of branched-chain amino acids and stability of their solutions.

Science.gov (United States)

Hong, Chi Rac; Lee, Gyu Whan; Paik, Hyun-Dong; Chang, Pahn-Shick; Choi, Seung Jun

2018-01-15

This study confirmed the possibility of biopolymer-type stabilizers to increase the saturation concentration of branched-chain amino acids by preventing their crystallization/precipitation. Although microfluidization increased the initial solubility, it failed to increase the saturation concentration of the branched-chain amino acids. The saturation concentration of the branched-chain amino acids increased from 3.81% to 4.42% and 4.85% after the incorporation of food hydrocolloids and proteins, respectively. However, the branched-chain amino acids:stabilizer ratio did not affect the solubility. In the case of food hydrocolloid-based solutions, crystal formation and growth of branched-chain amino acids occurred during storage, resulting in the precipitation of branched-chain amino acid crystals. However, food proteins effectively increased the stability of the solubilized branched-chain amino acids. The improved solubility and stability of the solubilized branched-chain amino acids could be attributed to interactions between the functional groups (carboxyl, amine, sulfate, aliphatic, aromatic, etc.) of the stabilizer and the branched-chain amino acid molecules. Copyright © 2017 Elsevier Ltd. All rights reserved.

Preservation of and Permanent Access to Electronic Information Resources

National Research Council Canada - National Science Library

Hodge, Gail

2004-01-01

The rapid growth in the creation and dissemination of electronic information has emphasized the digital environment's speed and ease of dissemination with little regard for its long-term preservation and access...

Implementating Information Technology in E-Human Resource Management

Directory of Open Access Journals (Sweden)

Cristina-Dana Popescu (Mitu

2016-01-01

More and more organizations have been replacing face-to-face human resource managementactivities with electronic human resource management, which is considered as one of the keyfactors that every organization needs to focus. Considering that human resource management isone of the necessary needs of today’s business, the goal of this article is to establish the importanceof human resource management (HRM, to examine recent research in e-HRM in order to evaluatethe cumulated evidence on the relationship between HRM and e-HRM and to outline the impact ofe-HRM on human resource. Many specialists underlined the fact that human resource requiresmore attention and careful management than any other resource of an organization. This paperalso deals with the influence of Internet and information technology on work and human resourcemanagement.

Bio-Based Coatings for Paper Applications

Directory of Open Access Journals (Sweden)

Vibhore Kumar Rastogi

2015-11-01

Full Text Available The barrier resistance and wettability of papers are commonly controlled by the application of petroleum-based derivatives such as polyethylene, waxes and/or fluor- derivatives as coating. While surface hydrophobicity is improved by employing these polymers, they have become disfavored due to limitations in fossil-oil resources, poor recyclability, and environmental concerns on generated waste with lack of biodegradation. Alternatively, biopolymers including polysaccharides, proteins, lipids and polyesters can be used to formulate new pathways for fully bio-based paper coatings. However, difficulties in processing of most biopolymers may arise due to hydrophilicity, crystallization behavior, brittleness or melt instabilities that hinder a full exploitation at industrial scale. Therefore, blending with other biopolymers, plasticizers and compatibilizers is advantageous to improve the coating performance. In this paper, an overview of barrier properties and processing of bio-based polymers and their composites as paper coating will be discussed. In particular, recent technical advances in nanotechnological routes for bio-based nano- composite coatings will be summarized, including the use of biopolymer nanoparticles, or nanofillers such as nanoclay and nanocellulose. The combination of biopolymers along with surface modification of nanofillers can be used to create hierarchical structures that enhance hydrophobicity, complete barrier protection and functionalities of coated papers.

Chemical characterization of Xanthan biopolymers synthesized by Xanthomonas campestris pv pruni strains; Caracterizacao quimica de biopolimeros sintetizados por Xanthomonas campestris pv pruni

Energy Technology Data Exchange (ETDEWEB)

Moreira, Angelita da S.; Vendruscolo, Claire T.; Furlan, Ligia [Universidade Federal de Pelotas, RS (Brazil). Centro de Biotecnologia]. E-mail: angelita@ufpel.tche.br; claire@ufpel.tche.br; ligia@ufpel.tche.br; Galland, Griselda [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Qumica

2001-07-01

In this work we describe the characterisation of Xanthan biopolymers synthesized by two Xanthomonas campestris pv pruni strains, in aerobic fermentation. By chromatography on TLC we could notice the presence of Mannose monomer in higher proportion in the 82 strain with relation to the another ones. The viscosity results showed the temperature dependence. The 06 and 82 strains had their viscosity increased whereas for the 87 strain we could observe a reduction with temperature increasing. The {sup 13}C NMR spectrum of 87 strain showed the characteristic signals at approximately 92.8, 70.4 and 61.4 ppm, attributed to C1, C4 and C6 from glucose monomer, with higher intensity. (author)

Low energy electron diffraction (LEED) and sum frequency generation (SFG) vibrational spectroscopy studies of solid-vacuum, solid-air and solid-liquid interfaces

Energy Technology Data Exchange (ETDEWEB)

Hoffer, Saskia [Univ. of California, Berkeley, CA (United States)

2002-01-01

Electron based surface probing techniques can provide detailed information about surface structure or chemical composition in vacuum environments. The development of new surface techniques has made possible in situ molecular level studies of solid-gas interfaces and more recently, solid-liquid interfaces. The aim of this dissertation is two-fold. First, by using novel sample preparation, Low Energy Electron Diffraction (LEED) and other traditional ultra high vacuum (UHV) techniques are shown to provide new information on the insulator/vacuum interface. The surface structure of the classic insulator NaCl has been determined using these methods. Second, using sum frequency generation (SFG) surface specific vibrational spectroscopy studies were performed on both the biopolymer/air and electrode/electrolyte interfaces. The surface structure and composition of polyetherurethane-silicone copolymers were determined in air using SFG, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). SFG studies of the electrode (platinum, gold and copper)/electrolyte interface were performed as a function of applied potential in an electrochemical cell.

Looking for Guidelines for the Production of Electronic Textbooks.

Science.gov (United States)

Landoni, M.; Wilson, R.; Gibb, F.

2001-01-01

Reports the results of two studies of electronic book production, including production on the World Wide Web, and explains EBONI (Electronic Books On-screen Interface) that focuses on the evaluation of electronic resources and compiling guidelines for publishing electronic materials on the Internet for the United Kingdom higher education…

impact of the use of electronic resources on research output

African Journals Online (AJOL)

manda

... Julita Nawe. University of Dar Es Salaam Library, P.O. Box 35092, Dar Es Salaam, Tanzania .... significantly, while 28.3% observed that quality of service to the community had improved .... resources and evaluate them is an important area.

Social Studies Online Resources. Media Corner.

Science.gov (United States)

Wilson, Jeri, Ed.

1995-01-01

Maintains that three types of social studies activities are found on the information highway: (1) electronic mail; (2) information; and (3) conferencing. Describes examples of each. Discusses commercial services and resource materials and provides references to online services. (CFR)

Green Supply Chain Collaboration for Fashionable Consumer Electronics Products under Third-Party Power Intervention—A Resource Dependence Perspective

Directory of Open Access Journals (Sweden)

Jiuh-Biing Sheu

2014-05-01

Full Text Available Under third-party power intervention (TPPI, which increases uncertainty in task environments, complex channel power interplays and restructuring are indispensable among green supply chain members as they move toward sustainable collaborative relationships for increased viability and competitive advantage. From the resource dependence perspective, this work presents a novel conceptual model to investigate the influence of political and social power on channel power restructuring and induced green supply chain collaboration in brander-retailer bidirectional green supply chains of fashionable consumer electronics products (FCEPs. An FCEP refers to the consumer electronics product (e.g., personal computers, mobile phones, computer notebooks, and game consoles with the features of a well-known brand associated, a short product lifecycle, timely and fashionable design fit for market trends, and quick responsiveness to the variations of market demands. The proposed model is tested empirically using questionnaire data obtained from retailers in the FCEP brander-retailer distribution channels. Analytical results reveal that as an extension of political and social power, TPPI positively affects the reciprocal interdependence of dyadic members and reduces power asymmetry, thereby enhancing the collaborative relationship of dyadic members and leading to improved green supply chain performance. Therein, reciprocal interdependence underlying collaborative relationship is the key to reducing the external environmental uncertainties in the TPPI context.

Electron beam pasteurised oil palm waste: a potential feed resource

International Nuclear Information System (INIS)

Mat Rasol Awang; Hassan Hamdani Mutaat; Tamikazu Kume; Tachibana, H.

2002-01-01

Pasteurization of oil palm empty fruit bunch (EFB) was performed using electron beam single sided irradiation. The dose profiles of oil palm EFB samples for different thickness in both directions X and Y were established. The results showed the usual characteristics dose uniformity as sample thickness decreased. The mean average absorbed dose on both sides at the surface and bottom of the samples for different thickness samples lead to establishing depth dose curve. Based on depth dose curve and operation conditions of electron beam machine, the process throughput for pasteurized oil palm EFB were estimated. (Author)

The cellulose resource matrix.

Science.gov (United States)

Keijsers, Edwin R P; Yılmaz, Gülden; van Dam, Jan E G

2013-03-01

The emerging biobased economy is causing shifts from mineral fossil oil based resources towards renewable resources. Because of market mechanisms, current and new industries utilising renewable commodities, will attempt to secure their supply of resources. Cellulose is among these commodities, where large scale competition can be expected and already is observed for the traditional industries such as the paper industry. Cellulose and lignocellulosic raw materials (like wood and non-wood fibre crops) are being utilised in many industrial sectors. Due to the initiated transition towards biobased economy, these raw materials are intensively investigated also for new applications such as 2nd generation biofuels and 'green' chemicals and materials production (Clark, 2007; Lange, 2007; Petrus & Noordermeer, 2006; Ragauskas et al., 2006; Regalbuto, 2009). As lignocellulosic raw materials are available in variable quantities and qualities, unnecessary competition can be avoided via the choice of suitable raw materials for a target application. For example, utilisation of cellulose as carbohydrate source for ethanol production (Kabir Kazi et al., 2010) avoids the discussed competition with easier digestible carbohydrates (sugars, starch) deprived from the food supply chain. Also for cellulose use as a biopolymer several different competing markets can be distinguished. It is clear that these applications and markets will be influenced by large volume shifts. The world will have to reckon with the increase of competition and feedstock shortage (land use/biodiversity) (van Dam, de Klerk-Engels, Struik, & Rabbinge, 2005). It is of interest - in the context of sustainable development of the bioeconomy - to categorize the already available and emerging lignocellulosic resources in a matrix structure. When composing such "cellulose resource matrix" attention should be given to the quality aspects as well as to the available quantities and practical possibilities of processing the

The Use of Electronic Resources by Academic Staff at the University of Ilorin, Nigeria

Science.gov (United States)

Tella, Adeyinka; Orim, Faith; Ibrahim, Dauda Morenikeji; Memudu, Suleiman Ajala

2018-01-01

The use of e-resources is now commonplace among academics in tertiary educational institutions the world over. Many academics including those in the universities are exploring the opportunities of e-resources to facilitate teaching and research. As the use of e-resources is increasing particularly among academics at the University of Ilorin,…

Building the electronic industry's roadmaps

Science.gov (United States)

Boulton, William R.

1995-02-01

JTEC panelists found a strong consistency among the electronics firms they visited: all the firms had clear visions or roadmaps for their research and development activities and had committed resources to ensure that they achieve targeted results. The overarching vision driving Japan's electronics industry is that of achieving market success through developing appealing, high-quality, low-cost consumer goods - ahead of the competition. Specifics of the vision include improving performance, quality, and portability of consumer electronics products. Such visions help Japanese companies define in detail the roadmaps they will follow to develop new and improved electronic packaging technologies.

The genome sequence of the commercially cultivated mushroom Agrocybe aegerita reveals a conserved repertoire of fruiting-related genes and a versatile suite of biopolymer-degrading enzymes.

Science.gov (United States)

Gupta, Deepak K; Rühl, Martin; Mishra, Bagdevi; Kleofas, Vanessa; Hofrichter, Martin; Herzog, Robert; Pecyna, Marek J; Sharma, Rahul; Kellner, Harald; Hennicke, Florian; Thines, Marco

2018-01-15

Agrocybe aegerita is an agaricomycete fungus with typical mushroom features, which is commercially cultivated for its culinary use. In nature, it is a saprotrophic or facultative pathogenic fungus causing a white-rot of hardwood in forests of warm and mild climate. The ease of cultivation and fructification on solidified media as well as its archetypal mushroom fruit body morphology render A. aegerita a well-suited model for investigating mushroom developmental biology. Here, the genome of the species is reported and analysed with respect to carbohydrate active genes and genes known to play a role during fruit body formation. In terms of fruit body development, our analyses revealed a conserved repertoire of fruiting-related genes, which corresponds well to the archetypal fruit body morphology of this mushroom. For some genes involved in fruit body formation, paralogisation was observed, but not all fruit body maturation-associated genes known from other agaricomycetes seem to be conserved in the genome sequence of A. aegerita. In terms of lytic enzymes, our analyses suggest a versatile arsenal of biopolymer-degrading enzymes that likely account for the flexible life style of this species. Regarding the amount of genes encoding CAZymes relevant for lignin degradation, A. aegerita shows more similarity to white-rot fungi than to litter decomposers, including 18 genes coding for unspecific peroxygenases and three dye-decolourising peroxidase genes expanding its lignocellulolytic machinery. The genome resource will be useful for developing strategies towards genetic manipulation of A. aegerita, which will subsequently allow functional genetics approaches to elucidate fundamentals of fruiting and vegetative growth including lignocellulolysis.

Removal of glyphosate herbicide from water using biopolymer membranes.

Science.gov (United States)

Carneiro, Rafael T A; Taketa, Thiago B; Gomes Neto, Reginaldo J; Oliveira, Jhones L; Campos, Estefânia V R; de Moraes, Mariana A; da Silva, Camila M G; Beppu, Marisa M; Fraceto, Leonardo F

2015-03-15

treat a water sample contaminated with glyphosate. Biopolymer membranes therefore potentially offer a versatile method to eliminate agricultural chemicals from water supplies. Copyright © 2015 Elsevier Ltd. All rights reserved.

Resources to Manage a Private Practice.

Science.gov (United States)

Aigner, John; Cheek, Fredricka; Donati, Georgia; Zuravicky, Dori

1997-01-01

Includes four theme articles: "The Digital Toolkit: Electronic Necessities for Private Practice" (John Aigner); "Organizing a Private Practice: Forms, Fees, and Physical Set-up (Fredricka Cheek); "Career Development Resources: Guidelines for Setting Up a Private Practice Library" (Georgia Donati); and "Books to…

Spinodal decomposition in a food colloid-biopolymer mixture: evidence for a linear regime

Energy Technology Data Exchange (ETDEWEB)

Bhat, Suresh [Department of Physics and Fribourg Center for Nanomaterials, University of Fribourg, 1700 Fribourg (Switzerland); Tuinier, Remco [Forschungszentrum Juelich, Institut fuer Festkoerperforschung, 52425 Juelich (Germany); Schurtenberger, Peter [Department of Physics and Fribourg Center for Nanomaterials, University of Fribourg, 1700 Fribourg (Switzerland)

2006-07-05

We investigate phase separation and structural evolution in a complex food colloid (casein micelles) and biopolymer (xanthan) mixture using small-angle light scattering. We demonstrate that phase separation is induced by a depletion mechanism, and that the resulting coexistence curve can be described by osmotic equilibrium theory for mixtures of colloids and polymer chains in a background solvent, taking into account interactions between the polymer chains in the excluded volume limit. We show that the light scattering pattern of an unstable mixture exhibits the typical behaviour of spinodal decomposition, and we are able to confirm the validity of dynamic similarity scaling. We find three distinct regimes (initial or linear, intermediate and transition stage) for the decomposition kinetics that differ in the time dependence of the peak position of the structure factor. In particular we find clear evidence for the existence of an initial linear regime, where the peak position remains constant and the amplitude grows. The existence of spinodal-like decomposition and the validity of universal scaling in the intermediate and transition stages have been found in previous studies of phase separation in attractive colloidal suspensions. However, to our knowledge the initial linear regime has never been observed in colloidal suspensions, and we attribute this at least partly to the effect of hydrodynamic interactions which are efficiently screened in our system due to the fact that the measurements were performed at high polymer concentrations, i.e. in the semi-dilute regime. (letter to the editor)

Structure and interactions in biomaterials based on membrane-biopolymer self-assembly

Science.gov (United States)

Koltover, Ilya

Physical and chemical properties of artificial pure lipid membranes have been extensively studied during the last two decades and are relatively well understood. However, most real membrane systems of biological and biotechnological importance incorporate macromolecules either embedded into the membranes or absorbed onto their surfaces. We have investigated three classes of self-assembled membrane-biopolymer biomaterials: (i) Structure, interactions and stability of the two-dimensional crystals of the integral membrane protein bacteriorhodopsin (bR). We have conducted a synchrotron x-ray diffraction study of oriented bR multilayers. The important findings were as follows: (1) the protein 2D lattice exhibited diffraction patterns characteristic of a 2D solid with power-law decay of in-plane positional correlations, which allowed to measure the elastic constants of protein crystal; (2) The crystal melting temperature was a function of the multilayer hydration, reflecting the effect of inter-membrane repulsion on the stability of protein lattice; (3) Preparation of nearly perfect (mosaicity gene therapy applications. We have established that DNA complexes with cationic lipid (DOTAP) and a neutral lipid (DOPC) have a compact multilayer liquid crystalline structure ( L ca ) with DNA intercalated between the lipid bilayers in a periodic 2D smectic phase. Furthermore, a different 2D columnar phase of complexes was found in mixtures with a transfectionen-hancing lipid DOPE. This structure ( HcII ) derived from synchrotron x-ray diffraction consists of DNA coated by cationic lipid monolayers and arranged on a two-dimensional hexagonal lattice. Optical microscopy revealed that the L ca complexes bind stably to anionic vesicles (models of cellular membranes), whereas the more transfectant HcII complexes are unstable, rapidly fusing and releasing DNA upon adhering to anionic vesicles.

Application of an amine functionalized biopolymer in the colonic delivery of glycyrrhizin: a design and in vivo efficacy study.

Science.gov (United States)

Kumar De, Amit; Datta, Sriparna; Mukherjee, Arup

2013-01-01

In our current study, a newer amine functionalized guar gum derivative was studied for its efficacy in colonic drug delivery. Glycyrrhizic acid mono-ammonium salt was used as the model drug. Drug-loaded microparticles were formulated by ionic crosslinking using sodium tripolyphosphate. The Scanning Electron Microscopic study revealed spherical particles of sizes from 4.9 ± 3.8 μm to 6.9 ± 3.9 μm. The FT-IR studies presented a possible interaction between the drug and the polymer. The drug was encapsulated in amorphous form as observed from the powder X-Ray Diffraction studies. A cumulative drug release study was carried out in simulated gastric, intestinal, and colonic fluids. The cumulative drug release studies presented a burst release followed by a sustained release of the drug in simulated colonic fluid containing rat cecal contents. The drug-polymer ratio was optimised using a 3(2) factorial design by taking the amounts of glycyrrhizic acid (X1) and guar gum alkyl amine (X2) as the independant variables. The percent cumulative drug release at 240 mins (Q240), 720 mins (Q720), and at 1,440 mins (Q1440) were considered as the dependant variables. The efficacy of the optimized formulation was studied in a 2,4,6-trinitrobenzene sulfonic acid-induced rat colitis model. The tissue's nitric oxide, malondialdehyde, and myeloperoxidase activities were found to be much lower in the microparticle-treated group compared to free drug-treated group. The histology of the colonic tissue from the treated group of animals revealed almost no infiltration of inflammatory cells in the tissue for the microparticle-treated group of animals. The synthesized amine derivative of guar gum was found to be better in vitro with a better in vivo efficacy in the colonic delivery of glycyrrhizic acid monoammonium salt and can be considered as a newer modified biopolymer for colonic drug delivery.

Synthesis, physiochemical and optical properties of chitosan based dye containing naphthalimide group.

Science.gov (United States)

Kumar, Santosh; Koh, Joonseok

2013-04-15

A new biopolymer dye containing naphthalimide moiety was synthesized by reaction of N-naphthaloyl chitosan with 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-piperazino-3-quinolinecarboxylic acid. N-naphthaloyl chitosan was synthesized by reaction of chitosan with 4-bromo-1,8-naphthalic anhydride in aqueous media by greener approach. The degree of substitution of chitosan biopolymer dye is 0.55 with a yield of 70%. The synthesized materials were characterized by using UV-vis, (1)H NMR, FTIR, and FT-Raman spectroscopy. Some physical properties and surface morphology were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Optical properties of chitosan biopolymer dye were evaluated by photoluminescence (PL) spectroscopy that showed red shift (λ(em)) peak at 442 nm and 551 nm at excitation wavelength 325 nm in comparison to chitosan. The solubility of chitosan biopolymer dye increased in most of the organic solvents. These results may provide new perspectives in biomedical applications as an optical and sensitive biosensor material. Copyright © 2013 Elsevier Ltd. All rights reserved.

Current status of electron beam treatment of flue gas in China

International Nuclear Information System (INIS)

Wang Zhiguang

2006-01-01

Fossil resource especially coal will remain the main energy resource in China over the next 3 ∼4 decades. Pollution of flue gas from fossil power station is one problem being desiderated to solve since 1990's. Electron beam treatment of flue gas as an advanced technique has been developed and used by some institutes and industries in China. The current status of flue gas treatment using electron beam and the development of electron accelerator in China are reviewed. (author)

Change in the fouling propensity of sludge in membrane bioreactors (MBR) in relation to the accumulation of biopolymer clusters.

Science.gov (United States)

Sun, Fei-yun; Wang, Xiao-mao; Li, Xiao-yan

2011-04-01

A membrane bioreactor (MBR) and an activated sludge process (ASP) were operated side by side to evaluate the change of sludge supernatant characteristics and the evolution of the sludge fouling propensity. The MBR sludge had a higher organic concentration and more biopolymer clusters (BPC) in the supernatant compared with ASP. BPC increased in both concentration and size in the MBR. The results show that the change in the liquid-phase property had a profound effect on the sludge fouling propensity. MBR operation transformed typical activated sludge to MBR sludge with a higher fouling propensity. Distinct from the ASP, membrane filtration retained soluble microbial products (SMP) within the MBR, and the vast membrane surface provided a unique environment for the transformation of SMP to large size BPC, leading to further sludge deposition on the membrane surface. Thus, membrane filtration is the crucial cause of the inevitable fouling problem in submerged MBRs. Copyright © 2011 Elsevier Ltd. All rights reserved.

Kaxiras’s Porphyrin: DFT Modeling of Redox-Tuned Optical and Electronic Properties in a Theoretically Designed Catechol-Based Bioinspired Platform

Directory of Open Access Journals (Sweden)

Orlando Crescenzi

2017-11-01

Full Text Available A detailed computational investigation of the 5,6-dihydroxyindole (DHI-based porphyrin-type tetramer first described by Kaxiras as a theoretical structural model for eumelanin biopolymers is reported herein, with a view to predicting the technological potential of this unique bioinspired tetracatechol system. All possible tautomers/conformers, as well as alternative protonation states, were explored for the species at various degrees of oxidation and all structures were geometry optimized at the density functional theory (DFT level. Comparison of energy levels for each oxidized species indicated a marked instability of most oxidation states except the six-electron level, and an unexpected resilience to disproportionation of the one-electron oxidation free radical species. Changes in the highest energy occupied molecular orbital (HOMO–lowest energy unoccupied molecular orbital (LUMO gaps with oxidation state and tautomerism were determined along with the main electronic transitions: more or less intense absorption in the visible region is predicted for most oxidized species. Data indicated that the peculiar symmetry of the oxygenation pattern pertaining to the four catechol/quinone/quinone methide moieties, in concert with the NH centers, fine-tunes the optical and electronic properties of the porphyrin system. For several oxidation levels, conjugated systems extending over two or more indole units play a major role in determining the preferred tautomeric state: thus, the highest stability of the six-electron oxidation state reflects porphyrin-type aromaticity. These results provide new clues for the design of innovative bioinspired optoelectronic materials.

Where Doctors Read Health Information Resources and Their ...

African Journals Online (AJOL)

Resources Media Preferences. Obianuju E. ... The survey research design was adopted for the study. ... media of assessing health information are the internet, electronic databases, textbooks, journals and .... for Social Sciences (SPSS).

eLearning resources to supplement postgraduate neurosurgery training.

OpenAIRE

Stienen, MN; Schaller, K; Cock, H; Lisnic, V; Regli, L; Thomson, S

2017-01-01

BACKGROUND: In an increasingly complex and competitive professional environment, improving methods to educate neurosurgical residents is key to ensure high-quality patient care. Electronic (e)Learning resources promise interactive knowledge acquisition. We set out to give a comprehensive overview on available eLearning resources that aim to improve postgraduate neurosurgical training and review the available literature. MATERIAL AND METHODS: A MEDLINE query was performed, using the search ter...

Electronic Commerce: Government Services in the New Millennium.

Science.gov (United States)

Maxwell, Terrence A., Ed.

1998-01-01

This newsletter features innovations in resource management and information technology to support New York State government. The newsletter contains the following six sections: (1) "Electronic Commerce: Government Services in the New Millennium" -- examining the need for government involvement in electronic commerce policy and…

Effects of hydrostatic pressure and supercritical carbon dioxide on the viability of Botryococcus braunii algae cells

NARCIS (Netherlands)

Yildiz-Ozturk, Ece; Ilhan-Ayisigi, Esra; Togtema, Arnoud; Gouveia, Joao; Yesil-Celiktas, Ozlem

2018-01-01

In bio-based industries, Botryococcus braunii is identified as a potential resource for production of hydrocarbons having a wide range of applications in chemical and biopolymer industries. For a sustainable production platform, the algae cultivation should be integrated with downstream processes.

Electronic Publishing Approaches to Curriculum: Videotex, Teletext and Databases.

Science.gov (United States)

Aumente, Jerome

1986-01-01

Describes the Journalism Resources Institute (JRI) of Rutgers University in terms of its administrative organization, computer resources, computer facilities use, involvement in electronic publishing, use of the Dow Jones News/Retrieval Database, curricular options, and professional continuing education. (AYC)

Structural and ionic conductivity studies on proton conducting solid biopolymer electrolyte based on 2hydroxyethyl cellulose incorporated DTAB

Science.gov (United States)

Ahmad, N. H.; Bakar, N. Y.; Isa, M. I. N.

2017-09-01

Solid biopolymer electrolytes (SBEs) based on 2hydroxyethyl cellulose (2HEC) complexes with dodecyltrimethyl ammonium bromide (DTAB) salt in various composition (wt. %) were successfully prepared by using solution casting technique. The ion - polymer interaction and structural studies have been reported by Fourier transform infrared spectroscopy (FTIR) supported with X - ray diffraction (XRD) and Electrical impedance spectroscopy (EIS). FTIR spectral shows interaction of 2HEC with DTAB happen at peak 2914cm-1, 2848cm-1, 2353cm-1, 2328cm-1, 1720cm-1, 1437cm-1, 1344cm-1, 1198cm-1 1095cm-1 1051cm-1, 912cm-1 and 872cm-1. The interaction of complexes leads to an increase in number of ion jump into neighboring vacant sites until it reaches the highest conductivity at room temperature which is 2.80 x 10-5 Scm-1 for sample containing 9wt. % of DTAB. The temperature dependence of the SBEs system exhibits Arrhenius behavior and the XRD spectral analysis shows the higher salt loading the crystallinity of the SBEs which also increased.

PERii electronic journals: Assessing access and use by ...

African Journals Online (AJOL)

Peter G. Underwood

institutional subscription to electronic journals through the Programme for Enhancement of .... These strategies include the promotion and marketing of these .... assist students and other library users to access PERii electronic journals resources. ..... Smith, H. Bukirwa, H. Mukasa, O. Snell, P. Adeh-Nsoh, S. Mbuyita, ...

Electronic Information – Threat or Challenge to Librarians and ...

African Journals Online (AJOL)

Electronic Information – Threat or Challenge to Librarians and Library Buildings. ... electronic resources because as new things and methods emerge, they exist ... that world trends in the paper industry and Internet use do not justify the fears ...

Success factors for implementing and sustaining a mature electronic medical record in a low-resource setting: a case study of iSanté in Haiti.

Science.gov (United States)

deRiel, E; Puttkammer, N; Hyppolite, N; Diallo, J; Wagner, S; Honoré, J G; Balan, J G; Celestin, N; Vallès, J S; Duval, N; Thimothé, G; Boncy, J; Coq, N R L; Barnhart, S

2018-03-01

Electronic health information systems, including electronic medical records (EMRs), have the potential to improve access to information and quality of care, among other things. Success factors and challenges for novel EMR implementations in low-resource settings have increasingly been studied, although less is known about maturing systems and sustainability. One systematic review identified seven categories of implementation success factors: ethical, financial, functionality, organizational, political, technical and training. This case study applies this framework to iSanté, Haiti's national EMR in use in more than 100 sites and housing records for more than 750 000 patients. The author group, consisting of representatives of different agencies within the Haitian Ministry of Health (MSPP), funding partner the Centers for Disease Control and Prevention (CDC) Haiti, and implementing partner the International Training and Education Center for Health (I-TECH), identify successes and lessons learned according to the seven identified categories, and propose an additional cross-cutting category, sustainability. Factors important for long-term implementation success of complex information systems are balancing investments in hardware and software infrastructure upkeep, user capacity and data quality control; designing and building a system within the context of the greater eHealth ecosystem with a plan for interoperability and data exchange; establishing system governance and strong leadership to support local system ownership and planning for system financing to ensure sustainability. Lessons learned from 10 years of implementation of the iSanté EMR system are relevant to sustainability of a full range of increasingly interrelated information systems (e.g. for laboratory, supply chain, pharmacy and human resources) in the health sector in low-resource settings. © The Author 2017. Published by Oxford University Press in association with The London School of Hygiene

A study on the utilization of serial resources in selected tertiary ...

African Journals Online (AJOL)

A study on the utilization of serial resources in selected tertiary institutions in Ogun State. ... Lagos Journal of Library and Information Science ... Serial resources are publications either in printed form or electronic format issued in successive parts usually having numerical or chronological designations and intended to be ...

Modeling antecedents of electronic medical record system implementation success in low-resource setting hospitals.

Science.gov (United States)

Tilahun, Binyam; Fritz, Fleur

2015-08-01

With the increasing implementation of Electronic Medical Record Systems (EMR) in developing countries, there is a growing need to identify antecedents of EMR success to measure and predict the level of adoption before costly implementation. However, less evidence is available about EMR success in the context of low-resource setting implementations. Therefore, this study aims to fill this gap by examining the constructs and relationships of the widely used DeLone and MacLean (D&M) information system success model to determine whether it can be applied to measure EMR success in those settings. A quantitative cross sectional study design using self-administered questionnaires was used to collect data from 384 health professionals working in five governmental hospitals in Ethiopia. The hospitals use a comprehensive EMR system since three years. Descriptive and structural equation modeling methods were applied to describe and validate the extent of relationship of constructs and mediating effects. The findings of the structural equation modeling shows that system quality has significant influence on EMR use (β = 0.32, P quality has significant influence on EMR use (β = 0.44, P service quality has strong significant influence on EMR use (β = 0.36, P effect of EMR use on user satisfaction was not significant. Both EMR use and user satisfaction have significant influence on perceived net-benefit (β = 0.31, P mediating factor in the relationship between service quality and EMR use (P effect on perceived net-benefit of health professionals. EMR implementers and managers in developing countries are in urgent need of implementation models to design proper implementation strategies. In this study, the constructs and relationships depicted in the updated D&M model were found to be applicable to assess the success of EMR in low resource settings. Additionally, computer literacy was found to be a mediating factor in EMR use and user satisfaction of

Tumour eradication using synchronous thermal ablation and Hsp90 chemotherapy with protein engineered triblock biopolymer-geldanamycin conjugates.

Science.gov (United States)

Chen, Yizhe; Youn, Pilju; Pysher, Theodore J; Scaife, Courtney L; Furgeson, Darin Y

2014-12-01

Hepatocellular carcinoma (HCC) suffers high tumour recurrence rate after thermal ablation. Heat shock protein 90 (Hsp90) induced post-ablation is critical for tumour survival and progression. A combination therapy of thermal ablation and polymer conjugated Hsp90 chemotherapy was designed and evaluated for complete tumour eradication of HCC. A thermo-responsive, elastin-like polypeptide (ELP)-based tri-block biopolymer was developed and conjugated with a potent Hsp90 inhibitor, geldanamycin (GA). The anti-cancer efficacy of conjugates was evaluated in HCC cell cultures with and without hyperthermia (43 °C). The conjugates were also administered twice weekly in a murine HCC model as a single treatment or in combination with single electrocautery as the ablation method. ELP-GA conjugates displayed enhanced cytotoxicity in vitro and effective heat shock inhibition under hyperthermia. The conjugates alone significantly slowed the tumour growth without systemic toxicity. Four doses of thermo-responsive ELP-GA conjugates with concomitant simple electrocautery accomplished significant Hsp90 inhibition and sustained tumour suppression. Hsp90 inhibition plays a key role in preventing the recurrence of HCC, and the combination of ablation with targeted therapy holds great potential to improve prognosis and survival of HCC patients.

Two kinds of ketoprofen enteric gel beads (CA and CS-SA using biopolymer alginate

Directory of Open Access Journals (Sweden)

Bingchao Cheng

2018-03-01

Full Text Available To obtain expected rapid-release and sustained-release of ketoprofen gel beads, this paper adopted biopolymer alginate to prepare alginate beads and chitosan-alginate gel beads. Formulation factors were investigated and optimized by the single factor test. The release of ketoprofen from calcium alginate gel beads in pH 1.0 hydrochloric acid solution was less than 10% during 2 h, then in pH6.8 was about 95% during 45 min, which met the requirements of rapid-release preparations. However, the drug release of chitosan-alginate gel beads in pH1.0 was less than 5% during 2 h, then in pH6.8 was about 50% during 6 h and reached more than 95% during 12 h, which had a good sustained-release behavior. In addition, the release kinetics of keteprofen from the calcium alginate gel beads fitted well with the Korsmeyer–Peppas model and followed a case-II transport mechanism. However, the release of keteprofen from the chitosan-alginate gel beads exhibited a non-Fickian mechanism and based on the mixed mechanisms of diffusion and polymer relaxation from chitosan-alginate beads. In a word, alginate gel beads of ketoprofen were instant analgesic, while chitosan-alginate gel beads could control the release of ketoprofen during gastro-intestinal tract and prolong the drug's action time. Keywords: Gel beads, Enteric rapid-release, Enteric sustained-release, Ketoprofen

Application of ICT-based Learning Resources for University Inorganic Chemistry Course Training

Directory of Open Access Journals (Sweden)

Tatyana M. Derkach

2013-01-01

Full Text Available The article studies expediency and efficiency of various ICT-based learning resources use in university inorganic chemistry course training, detects difference of attitudes toward electronic resources between students and faculty members, which create the background for their efficiency loss

Innovation and development of exhibition electronic-commerce based on the properties of electronic-commerce

Science.gov (United States)

Zhang, Jiankang

2017-06-01

There are two roadmaps of accomplishing exhibition electronic-commerce innovation and development. The first roadmap is that the exhibition organizers should seek mutual benefit cooperation with professional electronic-commerce platform of correspondent area with exhibition projects, thus help exhibitors realize their market object. The second roadmap is to promote innovation and development of electronic-commerce (Business-to-Customer) between both exhibitors and purchasers. Exhibition electronic-commerce must focus on innovative development in the following functions: market research and information service; advertising and business negotiation; online trading and online payment. With the aid of electronic-commerce, exhibition enterprise could have distinctive strengths such as transactions with virtualization, transparency, high efficiency and low cost, enhancing market link during enterprise research and development, promoting the efficiency of internal team collaboration and the individuation of external service, and optimizing resource allocation.

大學圖書館電子資源之需求分析與行銷策略之研究 A Study of Demands Analysis and Marketing Strategy of Electronic Resources in University Library

Directory of Open Access Journals (Sweden)

Huang-Yu Liu

2008-03-01

Full Text Available 電子資源的出現，使得知識載體有了新的突破，提高了使用者的便利性與即時性。對於圖書館而言，如何使電子資源的使用效益達到最高，必須思考一套有效的行銷策略。電子資源行銷概念應以讀者為導向，尊重讀者的資訊需求，並利用各種宣傳技巧，行銷電子資源，使圖書館能提供更完善的服務。本研究之目的旨在探討讀者的使用需求及電子資源的推廣策略，以獲致最有效益的行銷方式。研究對象以開南大學日間部四學院（商學院、運輸觀光學院、資訊學院、人文社會學院）學生為樣本，佐以缺口分析模型為分析架構，藉以找出個案中讀者/學生對於電子資源使用的真實需求，並進而歸納出提供服務的大學圖書館在其推廣或行銷服務上可有的因應策略。The emergence of electronic resources has made new breakthrough in knowledge carriers because of their ease of use, instant availability, and the characteristic of no time and space constraints. For public libraries to achieve maximum efficiency in its electronic resources, it is necessary to seek the most effective marketing strategies. Therefore, the marketing concept of the electronic resources should be reader oriented, such as respecting and understanding library user’s information needs. Libraries also need to utilize various media and techniques to market the electronic resources, so that more comprehensive services and experiences can be provided to readers. The purpose of this study is to investigate library user’s needs and promotion strategies of electronic resources in order to identify the most effective ways of marketing. This study focuses on the students of the four colleges (College of Business, College of Tourism, College of Information, and College of Humanities and Social Science in Kainan University as subjects in the survey questionnaire. It uses the Gap Analysis

Purification and partial elucidation of the structure of an antioxidant carbohydrate biopolymer from the probiotic bacterium Bacillus coagulans RK-02.

Science.gov (United States)

Kodali, Vidya P; Perali, Ramu S; Sen, R

2011-08-26

An exopolysaccharide (EPS) was isolated from Bacillus coagulans RK-02 and purified by size exclusion chromatography. The purified, homogeneous EPS had an average molecular weight of ∼3 × 10⁴ Da by comparison with FITC-labeled dextran standards. In vivo evaluations showed that, like other reported polysaccharides, this EPS displayed significant antioxidant activity. FTIR spectroscopy analysis showed the presence of hydroxy, carboxy, and α-glycosidic linkages and a mannose residue. GC analysis indicated that the EPS was a heteropolymer composed of glucose, mannose, galactose, glucosamine, and fucose as monomeric constituent units. Partial elucidation of the structure of the carbohydrate biopolymer based on GC-MS and NMR analysis showed the presence of two unique sets of tetrasaccharide repeating units that have 1→3 and 1→6 glycosidic linkages. This is also the first report of a Gram-positive bacterial polysaccharide with both fucose as a sugar monomer and 1→3 and 1→6 glycosidic linkages in the molecular backbone.

GENDER ANALYSIS OF ELECTRONIC INFORMATION

African Journals Online (AJOL)

use of internet Search engines such as google, yahoo and other free internet resources was found ... empirical studies are undertaken to examine the influence of gender ... H3: Perceived ease of use is positively related to the use of electronic.

Electronics all-in-one for dummies

CERN Document Server

Lowe, Doug

2011-01-01

Take your electronics skills to the next level! If you're looking for a solitary resource that covers everything you need to know about electronics, then look no further. This friendly-and-straightforward guide introduces the basics of electronics and enhances your learning experience by debunking and explaining concepts such as circuits, analog and digital, schematics, voltage, safety concerns, and more. Packed with nearly 900 pages of detailed information, this book shows you how to develop your own breadboard, design your own circuit, and get savvy with schematics. Cover

Electronic U.S. Government Information: Policy Issues and Directions.

Science.gov (United States)

Hernon, Peter; McClure, Charles R.

1993-01-01

Provides an overview of U.S. federal information policy and its treatment of electronic information resources. Highlights include government publications; electronic government information; main providers of government information, including the Government Printing Office; the Freedom of Information Act; public access and use; information…

Connecting Print and Electronic Titles: An Integrated Approach at the University of Nebraska-Lincoln

Science.gov (United States)

Wolfe, Judith; Konecky, Joan Latta; Boden, Dana W. R.

2011-01-01

Libraries make heavy investments in electronic resources, with many of these resources reflecting title changes, bundled subsets, or content changes of formerly print material. These changes can distance the electronic format from its print origins, creating discovery and access issues. A task force was formed to explore the enhancement of catalog…

The electronic Rothamsted Archive (e-RA), an online resource for data from the Rothamsted long-term experiments.

Science.gov (United States)

Perryman, Sarah A M; Castells-Brooke, Nathalie I D; Glendining, Margaret J; Goulding, Keith W T; Hawkesford, Malcolm J; Macdonald, Andy J; Ostler, Richard J; Poulton, Paul R; Rawlings, Christopher J; Scott, Tony; Verrier, Paul J

2018-05-15

The electronic Rothamsted Archive, e-RA (www.era.rothamsted.ac.uk) provides a permanent managed database to both securely store and disseminate data from Rothamsted Research's long-term field experiments (since 1843) and meteorological stations (since 1853). Both historical and contemporary data are made available via this online database which provides the scientific community with access to a unique continuous record of agricultural experiments and weather measured since the mid-19 th century. Qualitative information, such as treatment and management practices, plans and soil information, accompanies the data and are made available on the e-RA website. e-RA was released externally to the wider scientific community in 2013 and this paper describes its development, content, curation and the access process for data users. Case studies illustrate the diverse applications of the data, including its original intended purposes and recent unforeseen applications. Usage monitoring demonstrates the data are of increasing interest. Future developments, including adopting FAIR data principles, are proposed as the resource is increasingly recognised as a unique archive of data relevant to sustainable agriculture, agroecology and the environment.

Internet resources and web pages for pediatric surgeons.

Science.gov (United States)

Lugo-Vicente, H

2000-02-01

The Internet, the largest network of connected computers, provides immediate, dynamic, and downloadable information. By re-architecturing the work place and becoming familiar with Internet resources, pediatric surgeons have anticipated the informatics capabilities of this computer-based technology creating a new vision of work and organization in such areas as patient care, teaching, and research. This review aims to highlight how Internet navigational technology can be a useful educational resource in pediatric surgery, examines web pages of interest, and defines ideas of network communication. Basic Internet resources are electronic mail, discussion groups, file transfer, and the Worldwide Web (WWW). Electronic mailing is the most useful resource extending the avenue of learning to an international audience through news or list-servers groups. Pediatric Surgery List Server, the most popular discussion group, is a constant forum for exchange of ideas, difficult cases, consensus on management, and development of our specialty. The WWW provides an all-in-one medium of text, image, sound, and video. Associations, departments, educational sites, organizations, peer-reviewed scientific journals and Medline database web pages of prime interest to pediatric surgeons have been developing at an amazing pace. Future developments of technological advance nurturing our specialty will consist of online journals, telemedicine, international chatting, computer-based training for surgical education, and centralization of cyberspace information into database search sites.

Biopolymer-based degradable nanofibres from renewable resources produced by freeze-drying

Czech Academy of Sciences Publication Activity Database

Vetrík, Miroslav; Přádný, Martin; Kobera, Libor; Šlouf, Miroslav; Rabyk, Mariia; Pospíšilová, Aneta; Štěpánek, Petr; Hrubý, Martin

2013-01-01

Roč. 3, č. 35 (2013), s. 15282-15289 ISSN 2046-2069 R&D Projects: GA ČR GAP108/10/1560; GA ČR GA202/09/2078 Grant - others:AV ČR(CZ) M200501201 Program:M Institutional support: RVO:61389013 Keywords : glycogen * nanofibres * poly(ethyl cyanoacrylate) Subject RIV: BO - Biophysics Impact factor: 3.708, year: 2013

Gauging User Interest in Non-Traditional Library Resources

Energy Technology Data Exchange (ETDEWEB)

Sandberg, Tami; Abbott, Jennifer

2015-06-23

The National Renewable Energy Laboratory (NREL) is a government funded research laboratory based in Golden, Colorado. In addition to collecting traditional library resources such as journals, conference proceedings, and print and electronic books, the library also spends a significant portion of its collection development funds on resources not often found in many libraries: technical industry standards (e.g., ISO, IEC, ASTM, IEEE) and energy-related market reports. Assessing user needs for these resources is difficult for a number of reasons, particularly because standardized usage statistics are lacking or non-existent. Standards and market reports are generally costly and include fairly restrictive license agreements, which increase the importance of making informed collection development decisions. This presentation will discuss the NREL Library's current collection assessment and development practices as they relate to these unique resources.

Sodium alginate: A promising biopolymer for corrosion protection of API X60 high strength carbon steel in saline medium.

Science.gov (United States)

Obot, I B; Onyeachu, Ikenna B; Kumar, A Madhan

2017-12-15

Sodium alginate (SA), a polysaccharide biopolymer, has been studied as an effective inhibitor against the corrosion of API X60 steel in neutral 3.5% NaCl using gravimetric and electrochemical techniques (OCP, EIS and EFM). The inhibition efficiency of the SA increased with concentration but was lower at higher temperature (70°C). Electrochemical measurements showed that the SA shifted the steel corrosion potential to more positive value and reduced the kinetics of corrosion by forming an adsorbed layer which mitigated the steel surface wetting, based on contact angle measurement. SEM-EDAX was used to confirm the inhibition of SA on API X60 steel surfaces. The SA adsorbs on the steel surface through a physisorption mechanism using its carboxylate oxygen according to UV-vis and ATR-IR measurements, respectively. This phenomena result in decreased localized pitting corrosion of the API X60 steel in 3.5% NaCl solution. Theoretical results using quantum chemical calculations and Monte Carlo simulations provide further atomic level insights into the interaction of SA with steel surface. Copyright © 2017 Elsevier Ltd. All rights reserved.

MendelWeb: An Electronic Science/Math/History Resource for the WWW.

Science.gov (United States)

Blumberg, Roger B.

This paper describes a hypermedia resource, called MendelWeb that integrates elementary biology, discrete mathematics, and the history of science. MendelWeb is constructed from Gregor Menders 1865 paper, "Experiments in Plant Hybridization". An English translation of Mendel's paper, which is considered to mark the birth of classical and…

FORMULATION AND TECHNOLOGY DEVELOPMENT OF HERBAL PHENOLIC BIOPOLYMER-CONTAINING FILMS FOR BURN TREATMENT.

Science.gov (United States)

Gokadze, S; Barbakadze, V; Mulkijanyan, K; Bakuridze, A; Bakuridze, L

2017-06-01

Application of phytofilms based on biosolublepolymers is considered as a prospectivemethod for burn treatment . Herbal remedies contain biologically active substances, that are relatively less toxic, do not cause skin irritation or allergic reactions and, importantly, affectstrains of the microorganisms and viruses resistant to antibiotics and synthetic drugs. Nowadays, the advantages are given to such burn healing drugs, which along with high specific efficacy, have analgesic, anti-inflammatory and antimicrobial effects, and don't irritate the tissues. The mentioned peculiarities are characteristic for a new herbal phenolic biopolymer poly[3-(3,4-dihydroxyphenyl) glyceric acid](PDGA), isolated from the roots and stems of different comfrey species . The aim of the study was the development of the formulation and technology of biosoluble films for burn treatment on the basis of PDGA. The optimal content of phytofilm for burn healing was selected on the basis of the biopharmaceutical study results. The impact of the film-former on the quality, adhesion and moisture absorption of the phytofilmhas been studied. The optimal degree of the phytofilm moisture, determining its high adhesive properties,was established. The film prepared on the basis of sodium alginate, with 30.4% humidity, demonstrated the greatest adhesion strength. After investigation of the PDGA release it was found, that the hydrophilic bases such as: sodium carboxymethyl-cellulose (69.2%) andsodium alginate (78,65%) appeared to be optimal among the others. At the same time, taking into consideration the disadvantages of sodium carboxymethyl-cellulose (tautening effect on burnt surface, relatively low stability), a film based on sodium alginate has been chosen. The manufacturing technology for obtaining PDGA-containing phytofilm by casting is proposed. Theshelf-lifeofproposedPDGA-containingphytofilmis 2 years.

Can an Excess Electron Localise on a Purine Moiety in the Adenine-thymine Watson-Crick Base Pair? A Computational Study

International Nuclear Information System (INIS)

Mazurkiewicz, Kamil; Haranczyk, Maciej; Gutowski, Maciej S.; Rak, Janusz

2007-01-01

The electron affinity and the propensity to electron-induced proton transfer (PT) of hydrogen-bonded complexes between the Watson-Crick adenine-thymine pair (AT) and simple organic acid (HX), attached to adenine in the Hoogsteen-type configuration, were studied at the B3LYP/6-31+G** level. Although the carboxyl group is deprotonated at physiological pH, its neutral form, COOH, resembles the peptide bond or the amide fragment in the side chain of asparagine (Asn) or glutamine (Gln). Thus, these complexes mimic the interaction between the DNA environment (e.g., proteins) and nucleobase pairs incorporated in the biopolymer. Electron attachment is thermodynamically feasible and adiabatic electron affinities range from 0.41 to 1.28 eV, while the vertical detachment energies of the resulting anions span the range of 0.39-2.88 eV. Low-energy activation barriers separate the anionic minima: aHX(AT) from the more stable single-PT anionic geometry, aHX(AT)-SPT, and aHX(AT)-SPT from the double-PT anionic geometry, aHX(AT)-DPT. Interaction between the adenine of the Watson-Crick AT base pair with an acidic proton donor probably counterbalances the larger EA of isolated thymine, as SOMO is almost evenly delocalized over both types of nucleic bases in the aHX(AT) anions. Moreover, as a result of PT the excess electron localizes entirely on adenine. Thus, in DNA interacting with its physiological environment, damage induced by low-energy electrons could begin, contrary to the current view, with the formation of purine anions, which are not formed in isolated DNA because of the greater stability of anionic pyrimidines.

Helping Patrons Find Locally Held Electronic Resources: An Interlibrary Loan Perspective

Science.gov (United States)

Johnston, Pamela

2016-01-01

The University of North Texas Libraries provide extensive online access to academic journals through major vendor databases. As illustrated by interlibrary loan borrowing requests for items held in our databases, patrons often have difficulty navigating the available resources. In this study, the Interlibrary Loan staff used data gathered from the…

Usability Testing for e-Resource Discovery: How Students Find and Choose e-Resources Using Library Web Sites

Science.gov (United States)

Fry, Amy; Rich, Linda

2011-01-01

In early 2010, library staff at Bowling Green State University (BGSU) in Ohio designed and conducted a usability study of key parts of the library web site, focusing on the web pages generated by the library's electronic resources management system (ERM) that list and describe the library's databases. The goal was to discover how users find and…

EDUCATIONAL NETWORK RESOURCES IN JOURNALISM AND PUBLISHING: FEATURES OF THE SITES' CONTENT AND DESIGN

Directory of Open Access Journals (Sweden)

Hanna A. Zenzina

2012-12-01

Full Text Available The article deals with the concept of electronic educational resource, its importance for the orientation of students in cyberspace, the basic requirements for the design and content of educational resources eligibility criteria standards. Filed benefits of having their own educational resource for high school. Singled out the importance of the interaction of educational resources with social networks. Detected differences and similarities of design and content of educational resources of Kyiv Universities in journalism and publishing.

Reliability criteria selection for integrated resource planning

International Nuclear Information System (INIS)

Ruiu, D.; Ye, C.; Billinton, R.; Lakhanpal, D.

1993-01-01

A study was conducted on the selection of a generating system reliability criterion that ensures a reasonable continuity of supply while minimizing the total costs to utility customers. The study was conducted using the Institute for Electronic and Electrical Engineers (IEEE) reliability test system as the study system. The study inputs and results for conditions and load forecast data, new supply resources data, demand-side management resource data, resource planning criterion, criterion value selection, supply side development, integrated resource development, and best criterion values, are tabulated and discussed. Preliminary conclusions are drawn as follows. In the case of integrated resource planning, the selection of the best value for a given type of reliability criterion can be done using methods similar to those used for supply side planning. The reliability criteria values previously used for supply side planning may not be economically justified when integrated resource planning is used. Utilities may have to revise and adopt new, and perhaps lower supply reliability criteria for integrated resource planning. More complex reliability criteria, such as energy related indices, which take into account the magnitude, frequency and duration of the expected interruptions are better adapted than the simpler capacity-based reliability criteria such as loss of load expectation. 7 refs., 5 figs., 10 tabs

Structure and interactions of calcite spherulites with α-chitin in the brown shrimp (Penaeus aztecus) shell

International Nuclear Information System (INIS)

Heredia, A.; Aguilar-Franco, M.; Magana, C.; Flores, C.; Pina, C.; Velazquez, R.; Schaeffer, T.E.; Bucio, L.; Basiuk, V.A.

2007-01-01

White spots form in the brown shrimp (Penaeus aztecus, Decapoda) shell during frozen storage. The mineral formed consists of calcite incorporated into an amorphous α-chitin matrix. We studied mechanisms of interaction of amorphous α-chitin macromolecules with hkl crystal planes to form highly ordered structures, as well as the role of specific sites in the biopolymer, which can be related to nucleation and spheroidal crystal growth. We used low vacuum scanning electron microscopy (LVSEM), X-ray powder diffraction (XRD), atomic force microscopy (AFM), Fourier-transform infrared spectroscopy (FT-IR), and molecular mechanics modeling (MM+ method). AFM images showed fingerprint distances in the biopolymer and a highly layered structure in the crystalline material. The presence of α-chitin, with a specific spatial distribution of radicals, is thought to be responsible for nucleation and to thermodynamically stabilize ions to form the spherulite crystalline phase, which are usually oval to spherical (0.10 to 200 μm in diameter). Our models of crystal-biopolymer interaction found high affinity of CO 3 2- anions in the (104) crystalline plane (the main plane in calcite monocrystals) to NH- groups of the biopolymer, as well as of the C=O in the biopolymer to Ca 2+ cations in the crystalline structure. These interactions explain the spherical growth and inhibition in some planes. The specific physicochemical interactions (docking of groups depending on their geometrical distribution) suggest that the biomineral structure is controlled by the biopolymer on a local scale. This information is useful for further design and improvement of (hybrid) materials for versatile application, from nanotechnology to biomedicine and engineering