WorldWideScience

Sample records for gelatin fiber mats

  1. Interaction of gelatin with polyenes modulates antifungal activity and biocompatibility of electrospun fiber mats

    Directory of Open Access Journals (Sweden)

    Lakshminarayanan R

    2014-05-01

    Full Text Available Rajamani Lakshminarayanan,1,2 Radhakrishnan Sridhar,3,4 Xian Jun Loh,5 Muruganantham Nandhakumar,1 Veluchamy Amutha Barathi,1,6 Madhaiyan Kalaipriya,3,4 Jia Lin Kwan,1 Shou Ping Liu,1,2 Roger Wilmer Beuerman,1,2 Seeram Ramakrishna3,4,7 1Singapore Eye Research Institute, 2Signature Research Program in Neuroscience and Behavioral Disorders, Duke-NUS Graduate Medical School, 3Department of Mechanical Engineering, National University of Singapore, 4Center for Nanofibers and Nanotechnology, National University of Singapore, 5Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research, 3 Research Link, Singapore, 6Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, 7NUS Nanoscience and Nanotechnology Initiative, Singapore Abstract: Topical application of antifungals does not have predictable or well-controlled release characteristics and requires reapplication to achieve therapeutic local concentration in a reasonable time period. In this article, the efficacy of five different US Food and Drug Administration-approved antifungal-loaded (amphotericin B, natamycin, terbinafine, fluconazole, and itraconazole electrospun gelatin fiber mats were compared. Morphological studies show that incorporation of polyenes resulted in a two-fold increase in fiber diameter and the mats inhibit the growth of yeasts and filamentous fungal pathogens. Terbinafine-loaded mats were effective against three filamentous fungal species. Among the two azole antifungals compared, the itraconazole-loaded mat was potent against Aspergillus strains. However, activity loss was observed for fluconazole-loaded mats against all of the test organisms. The polyene-loaded mats displayed rapid candidacidal activities as well. Biophysical and rheological measurements indicate strong interactions between polyene antifungals and gelatin matrix. As a result, the polyenes stabilized the triple helical

  2. Electrospun gelatin fiber mats containing a herbal—Centella asiatica—extract and release characteristic of asiaticoside

    Science.gov (United States)

    Sikareepaisan, Panprung; Suksamrarn, Apichart; Supaphol, Pitt

    2008-01-01

    Ultra-fine gelatin (type A, porcine skin, ~180 Bloom) fiber mats containing a methanolic crude extract of Centella asiatica (L.) Urban, a medicinal plant widely known for its traditional medical applications including its wound healing ability, were fabricated, for the first time, from the neat gelatin solution (22% w/v in 70 vol% acetic acid) containing the crude extract (mCA) in various amounts (i.e. 5-30 wt% based on the weight of gelatin powder) by electrospinning. Incorporation of mCA in the neat gelatin solution did not affect both the morphology and the size of the mCA-loaded gelatin fibers, as both of the neat and the mCA-loaded gelatin fibers were smooth and the average diameters of these fibers ranged between 226 and 232 nm. The cross-linked mCA-loaded e-spun gelatin fiber mat from the neat gelatin solution containing 30 wt% of mCA was further investigated for the release characteristic of asiaticoside, identified as the most active compound associated with the healing of wounds, in two different types of releasing medium, i.e. acetate buffer and the buffer containing 10 vol% of methanol, based on the thin-layer chromatography (TLC)-densitometry technique. Based on the unit weight of the actual amount of asiaticoside present in the specimens, the total amount of asiaticoside released from the fiber mat specimens was lower than that from the film counterparts while, based on the unit weight of the specimens, an opposite trend was observed.

  3. Electrospun gelatin fiber mats containing a herbal-Centella asiatica-extract and release characteristic of asiaticoside

    International Nuclear Information System (INIS)

    Sikareepaisan, Panprung; Suksamrarn, Apichart; Supaphol, Pitt

    2008-01-01

    Ultra-fine gelatin (type A, porcine skin, ∼180 Bloom) fiber mats containing a methanolic crude extract of Centella asiatica (L.) Urban, a medicinal plant widely known for its traditional medical applications including its wound healing ability, were fabricated, for the first time, from the neat gelatin solution (22% w/v in 70 vol% acetic acid) containing the crude extract (mCA) in various amounts (i.e. 5-30 wt% based on the weight of gelatin powder) by electrospinning. Incorporation of mCA in the neat gelatin solution did not affect both the morphology and the size of the mCA-loaded gelatin fibers, as both of the neat and the mCA-loaded gelatin fibers were smooth and the average diameters of these fibers ranged between 226 and 232 nm. The cross-linked mCA-loaded e-spun gelatin fiber mat from the neat gelatin solution containing 30 wt% of mCA was further investigated for the release characteristic of asiaticoside, identified as the most active compound associated with the healing of wounds, in two different types of releasing medium, i.e. acetate buffer and the buffer containing 10 vol% of methanol, based on the thin-layer chromatography (TLC)-densitometry technique. Based on the unit weight of the actual amount of asiaticoside present in the specimens, the total amount of asiaticoside released from the fiber mat specimens was lower than that from the film counterparts while, based on the unit weight of the specimens, an opposite trend was observed

  4. Fabrication and Characterization of Electrospun Polycaprolactone Blended with Chitosan-Gelatin Complex Nanofibrous Mats

    Directory of Open Access Journals (Sweden)

    Yongfang Qian

    2014-01-01

    Full Text Available Design and fabrication of nanofibrous scaffolds should mimic the native extracellular matrix. This study is aimed at investigating electrospinning of polycaprolactone (PCL blended with chitosan-gelatin complex. The morphologies were observed from scanning electron microscope. As-spun blended mats had thinner fibers than pure PCL. X-ray diffraction was used to analyze the degree of crystallinity. The intensity at two peaks at 2θ of 21° and 23.5° gradually decreased with the percentage of chitosan-gelatin complex increasing. Moreover, incorporation of the complex could obviously improve the hydrophilicity of as-spun blended mats. Mechanical properties of as-spun nanofibrous mats were also tested. The elongation at break of fibrous mats increased with the PCL content increasing and the ultimate tensile strength varied with different weight ratios. The as-spun mats had higher tensile strength when the weight ratio of PCL to CS-Gel was 75/25 compared to pure PCL. Both as-spun PCL scaffolds and PCL/CS-Gel scaffolds supported the proliferation of porcine iliac endothelial cells, and PCL/CS-Gel had better cell viability than pure PCL. Therefore, electrospun PCL/Chitosan-gelatin nanofibrous mats with weight ratio of 75/25 have better hydrophilicity mechanical properties, and cell proliferation and thus would be a promising candidate for tissue engineering scaffolds.

  5. Beaded Fiber Mats of PVA Containing Unsaturated Heteropoly Salt

    Institute of Scientific and Technical Information of China (English)

    Guo Cheng YANG; Yan PAN; Jian GONG; Chang Lu SHAO; Shang Bin WEN; Chen SHAO; Lun Yu QU

    2004-01-01

    Poly(vinyl alcohol) (PVA) fiber mats containing unsaturated heteropoly salt was prepared for the first time. IR, X-ray diffraction and SEM photographs characterized the beaded fiber mats.The viscoelasticity and the conductivity of the solution were the key factors that influence the formation of the beaded fiber mats.

  6. Fabrication of gelatin-siloxane fibrous mats via sol-gel and electrospinning procedure and its application for bone tissue engineering

    International Nuclear Information System (INIS)

    Ren Lei; Wang Jun; Yang Fangyu; Wang Lin; Wang Dong; Wang Tianxiao; Tian Miaomiao

    2010-01-01

    Our strategy is to design and fabricate biomimetic and bioactive scaffolds that resemble the native extracellular matrix as closely as possible so as to create conducive living milieu that will induce cell to function naturally. In the present study, gelatin/siloxane (GS) hybrids were prepared by a sol-gel processing, and electrospinning technique was used to fabricate GS fibrous mats to support the growth of bone marrow-derived mesenchymal stem cells (BMSCs) for tissue engineering of bone. The results indicate that the porous structure and fiber size of the GS fibrous mats can be fine tuned by varying the viscosity of GS precursor solution. Additionally, the Ca 2+ -containing GS fibrous mats biomimetically deposited apatite in a simulated body fluid (SBF), as well as stimulating its BMSCs proliferation and differentiation in vitro, thereby dignifying its in vitro bioactivity.

  7. Matted-fiber divertor tagets for sputter resistance

    International Nuclear Information System (INIS)

    Gierszewski, P.J.; Todreas, N.E.; Mikic, B.; Yang, T.F.

    1981-06-01

    Reductions in net sputtering yields can be obtained by altering the surface topography to maximize redeposition of sputtered atoms. A simple analysis is used to indicate a potential reduction by a factor of 2 to 5 for matted fiber divertor targets, relatively independent of incident, reflected and sputtered atom distributions. The fiber temperature is also shown to be acceptable, even up to 10 MW/m 2 , for reasonably combinations of materials, fiber diameter and fiber spacing

  8. Thermomechanical analyses of phenolic foam reinforced with glass fiber mat

    International Nuclear Information System (INIS)

    Zhou, Jintang; Yao, Zhengjun; Chen, Yongxin; Wei, Dongbo; Wu, Yibing

    2013-01-01

    Highlights: • Over 10% glass fiber was used to reinforce phenolic foam in the shape of glass fiber mat. • Nucleating agents were used together with glass fiber mat and improved tensile strength of phenolic foam by 215.6%. • Nucleating agents lead to a smaller bubble size of phenolic foam. • The glass transition temperature of phenolic foam remained unchanged during the reinforcement. - Abstract: In this paper, thermomechanical analysis (TMA) and dynamic mechanical analysis were employed to study the properties of phenolic foam reinforced with glass fiber mat. Unreinforced phenolic foam was taken as the control sample. Mechanical tests and scanning electron microscopy were performed to confirm the results of TMA. The results show that glass fiber mat reinforcement improves the mechanical performance of phenolic foam, and nucleating agents improve it further. Phenolic foam reinforced with glass fiber mat has a smaller thermal expansion coefficient compared with unreinforced foam. The storage modulus of the reinforced phenolic foam is also higher than that in unreinforced foam, whereas the loss modulus of the former is lower than that of the latter. The glass transition temperature of the phenolic foam matrix remains unchanged during the reinforcement

  9. Fabrication of nanocomposite mat through incorporating bioactive glass particles into gelatin/poly(ε-caprolactone) nanofibers by using Box–Behnken design

    Energy Technology Data Exchange (ETDEWEB)

    Gönen, Seza Özge, E-mail: gonens@itu.edu.tr; Erol Taygun, Melek; Aktürk, Ayşen; Küçükbayrak, Sadriye

    2016-10-01

    The current research was conducted to propose a nanocomposite material, which could be suitable to be used as a scaffold for bone tissue engineering applications. For this purpose, nanocomposite fibers of gelatin, poly(ε-caprolactone) (PCL), and bioactive glass were successfully fabricated via electrospinning process. In this context, response surface methodology based on a three-level, four-variable Box-Behnken design was adopted as an optimization tool to choose the most appropriate parameter settings to obtain the desired fiber diameter. The investigation, based on a second order polynomial model, focused on the analysis of the effect of both solution and processing parameters on the fiber diameter and its standard deviation. In optimum conditions (bioactive glass content of 7.5% (w/v), applied voltage of 25 kV, tip-to-collector distance of 12.5 cm, and flow rate of 1 mL/h), the fiber diameter was found to be 584 ± 337 nm which was in good agreement with the predicted value by the developed models (523 ± 290 nm). Analytical tools such as scanning electron microscopy, X-ray diffraction analysis, Fourier transform infrared spectroscopy, and differential thermal analyzer were used for further evaluation of the optimized nanocomposite mat. The overall results showed that nanocomposite scaffolds could be promising candidates for tissue engineering applications. - Highlights: • Nanocomposite fibers of gelatin, PCL, and bioactive glass were successfully fabricated. • Three-level, four-variable Box-Behnken design was adopted as an optimization tool. • The individual and interactive effects of the electrospinning parameters were determined. • Quadratic models were used to adjust the fiber diameter and its standard deviation.

  10. Fabrication of nanocomposite mat through incorporating bioactive glass particles into gelatin/poly(ε-caprolactone) nanofibers by using Box–Behnken design

    International Nuclear Information System (INIS)

    Gönen, Seza Özge; Erol Taygun, Melek; Aktürk, Ayşen; Küçükbayrak, Sadriye

    2016-01-01

    The current research was conducted to propose a nanocomposite material, which could be suitable to be used as a scaffold for bone tissue engineering applications. For this purpose, nanocomposite fibers of gelatin, poly(ε-caprolactone) (PCL), and bioactive glass were successfully fabricated via electrospinning process. In this context, response surface methodology based on a three-level, four-variable Box-Behnken design was adopted as an optimization tool to choose the most appropriate parameter settings to obtain the desired fiber diameter. The investigation, based on a second order polynomial model, focused on the analysis of the effect of both solution and processing parameters on the fiber diameter and its standard deviation. In optimum conditions (bioactive glass content of 7.5% (w/v), applied voltage of 25 kV, tip-to-collector distance of 12.5 cm, and flow rate of 1 mL/h), the fiber diameter was found to be 584 ± 337 nm which was in good agreement with the predicted value by the developed models (523 ± 290 nm). Analytical tools such as scanning electron microscopy, X-ray diffraction analysis, Fourier transform infrared spectroscopy, and differential thermal analyzer were used for further evaluation of the optimized nanocomposite mat. The overall results showed that nanocomposite scaffolds could be promising candidates for tissue engineering applications. - Highlights: • Nanocomposite fibers of gelatin, PCL, and bioactive glass were successfully fabricated. • Three-level, four-variable Box-Behnken design was adopted as an optimization tool. • The individual and interactive effects of the electrospinning parameters were determined. • Quadratic models were used to adjust the fiber diameter and its standard deviation.

  11. Fabrication of nanocomposite mat through incorporating bioactive glass particles into gelatin/poly(ε-caprolactone) nanofibers by using Box-Behnken design.

    Science.gov (United States)

    Gönen, Seza Özge; Erol Taygun, Melek; Aktürk, Ayşen; Küçükbayrak, Sadriye

    2016-10-01

    The current research was conducted to propose a nanocomposite material, which could be suitable to be used as a scaffold for bone tissue engineering applications. For this purpose, nanocomposite fibers of gelatin, poly(ε-caprolactone) (PCL), and bioactive glass were successfully fabricated via electrospinning process. In this context, response surface methodology based on a three-level, four-variable Box-Behnken design was adopted as an optimization tool to choose the most appropriate parameter settings to obtain the desired fiber diameter. The investigation, based on a second order polynomial model, focused on the analysis of the effect of both solution and processing parameters on the fiber diameter and its standard deviation. In optimum conditions (bioactive glass content of 7.5% (w/v), applied voltage of 25kV, tip-to-collector distance of 12.5cm, and flow rate of 1mL/h), the fiber diameter was found to be 584±337nm which was in good agreement with the predicted value by the developed models (523±290nm). Analytical tools such as scanning electron microscopy, X-ray diffraction analysis, Fourier transform infrared spectroscopy, and differential thermal analyzer were used for further evaluation of the optimized nanocomposite mat. The overall results showed that nanocomposite scaffolds could be promising candidates for tissue engineering applications. Copyright © 2016. Published by Elsevier B.V.

  12. Enhancement of the in-plane shear properties of carbon fiber composites containing carbon nanotube mats

    Science.gov (United States)

    Kim, Hansang

    2015-01-01

    The in-plane shear property of carbon fiber laminates is one of the most important structural features of aerospace and marine structures. Fiber-matrix debonding caused by in-plane shear loading is the major failure mode of carbon fiber composites because of the stress concentration at the interfaces. In this study, carbon nanotube mats (CNT mat) were incorporated in two different types of carbon fiber composites. For the case of woven fabric composites, mechanical interlocking between the CNTs and the carbon fibers increased resistance to shear failure. However, not much improvement was observed for the prepreg composites as a result of incorporation of the CNT mats. The reinforcement mechanism of the CNT mat layer was investigated by a fractographic study using scanning electron microscopy. In addition, the CNT mat was functionalized by three different methods and the effectiveness of the functionalization methods was determined and the most appropriate functionalization method for the CNT mat was air oxidation.

  13. Increasing Mechanical Properties of 2-D-Structured Electrospun Nylon 6 Non-Woven Fiber Mats

    Directory of Open Access Journals (Sweden)

    Chunhui Xiang

    2016-04-01

    Full Text Available Tensile strength, Young’s modulus, and toughness of electrospun nylon 6 non-woven fiber mats were improved by increasing individual nanofiber strength and fiber–fiber load sharing. Single-walled carbon nanotubes (CNTs were used as reinforcement to increase the strength of the electrospun nylon 6 nanofibers. Young’s modulus, tensile strength, and toughness of the nylon 6 non-woven fiber mats electrospun from 20 wt % solutions increased 51%, 87%, and 136%, respectively, after incorporating 1 wt % CNTs into the nylon 6 nanofibers. Three methods were investigated to enhance fiber–fiber load sharing: increasing friction between fibers, thermal bonding, and solvent bonding. The addition of beaded nylon 6 nanofibers into the non-woven fiber mats to increase fiber-fiber friction resulted in a statistically significantly increase in Young’s modulus over comparable smooth non-woven fiber mats. After annealing, tensile strength, elongation, and toughness of the nylon 6 non-woven fiber mats electrospun from 20 wt % + 10 wt % solutions increased 26%, 28%, and 68% compared to those from 20 wt % solutions. Solvent bonding with formic acid vapor at room temperature for 30 min caused increases of 56%, 67%, and 39% in the Young’s modulus, tensile strength, and toughness of non-woven fiber mats, respectively. The increases attributed to increased individual nanofiber strength and solvent bonding synergistically resulted in the improvement of Young’s modulus of the electrospun nylon 6 non-woven fiber mats.

  14. Polymer solution, fiber mat, and nanofiber membrane-electrode-assembly therewith, and method of fabricating same

    DEFF Research Database (Denmark)

    2016-01-01

    of fibers. The fibers may further include particles of a catalyst. The fiber mat may be used to form an electrode or a membrane. In a further aspect, a fuel cell membrane-electrode-assembly has an anode electrode, a cathode electrode, and a membrane disposed between the anode electrode and the cathode...... electrode. Each of the anode electrode, the cathode electrode and the membrane may be formed with a fiber mat....

  15. Development and characterization of cefazolin loaded zinc oxide nanoparticles composite gelatin nanofiber mats for postoperative surgical wounds

    International Nuclear Information System (INIS)

    Rath, Goutam; Hussain, Taqadus; Chauhan, Gaurav; Garg, Tarun; Goyal, Amit Kumar

    2016-01-01

    . Hence the fabricated composite nanofiber mats have the potential to be used as a postoperative antimicrobial wound dressings. - Highlights: • Gelatin nanofibers hybrid were successfully fabricated by electrospinning. • Hybrid nanofiber mats provided an accelerated wound healing. • ZnONPs showed fastened epithelial regeneration and a better cell attachment.

  16. Mechanical Properties of Natural Jute Fabric/Jute Mat Fiber Reinforced Polymer Matrix Hybrid Composites

    Directory of Open Access Journals (Sweden)

    Elsayed A. Elbadry

    2012-01-01

    Full Text Available Recycled needle punched jute fiber mats as a first natural fiber reinforcement system and these jute mats used as a core needle punched with recycled jute fabric cloths as skin layers as a second natural fiber reinforcement system were used for unsaturated polyester matrix composites via modifying the hand lay-up technique with resin preimpregnation into the jute fiber in vacuum. The effect of skin jute fabric on the tensile and bending properties of jute mat composites was investigated for different fiber weight contents. Moreover, the notch sensitivity of these composites was also compared by using the characteristic distance do calculated by Finite Element Method (FEM. The results showed that the tensile and flexural properties of jute mat composites increased by increasing the fiber weight content and by adding the jute fabric as skin layers. On the other hand, by adding the skins, the characteristic distance decreased and, therefore, the notch sensitivity of the composites increased. The fracture behavior investigated by SEM showed that extensive fiber pull-out mechanism was revealed at the tension side of jute mat composites under the bending load and by adding the jute cloth, the failure mode of jute mat was changed to fiber bridge mechanism.

  17. Hydrogel-Electrospun Fiber Mat Composite Coatings for Neural Prostheses

    Directory of Open Access Journals (Sweden)

    Ning eHan

    2011-03-01

    Full Text Available Achieving stable, long-term performance of implanted neural prosthetic devices has been challenging because of implantation related neuron loss and a foreign body response that results in encapsulating glial scar formation. To improve neuron-prosthesis integration and form chronic, stable interfaces, we investigated the potential of neurotrophin-eluting hydrogel-electrospun fiber mat (EFM composite coatings. In particular, poly(ethylene glycol-poly(ε-caprolactone (PEGPCL hydrogel- poly(ε-caprolactone (PCL EFM composites were applied as coatings for multielectrode arrays (MEAs. Coatings were stable and persisted on electrode surfaces for over 1 month under an agarose gel tissue phantom and over 9 months in a PBS immersion bath. To demonstrate drug release, a neurotrophin, nerve growth factor (NGF, was loaded in the PEGPCL hydrogel layer, and coating cytotoxicity and sustained NGF release were evaluated using a PC12 cell culture model. Quantitative MTT assays showed that these coatings had no significant toxicity toward PC12 cells, and neurite extension at day 7 and 14 confirmed sustained release of NGF at biologically significant concentrations for at least 2 weeks. Our results demonstrate that hydrogel-EFM composite materials can be applied to neural prostheses as a means to improve neuron-electrode proximity and enhance long-term device performance and function.

  18. Influence of fiber type, fiber mat orientation, and process time on the properties of a wood fiber/polymer composite

    DEFF Research Database (Denmark)

    Plackett, David; Torgilsson, R.; Løgstrup Andersen, T.

    2002-01-01

    involved pre-compression, contact heating to the process temperature under vacuum and then rapid transfer to the press for consolidation and cooling. Composites were tested to determine response to water or water vapor, porosity, fiber volume fraction and tensile properties. The composites absorbed water......A rapid press consolidation technique was used to produce composites from two types of air-laid wood fiber mat, incorporating either mechanically refined or bleached chemi-thermomechanically refined Norway Spruce [Picea abies (L.) Karst] and a bicomponent polymer fiber. The manufacturing technique...... rapidly and showed changes in thickness with fluctuations in relative humidity. Porosity was higher in composites containing mechanically refined (MDF) fibers than in composites containing bleached chemi-thermomechanically refined (CTMP) fibers. Tensile test results suggessted that fiber wetting...

  19. Effect of electron beam irradiation on mechanical properties of gelatin/Brazil nut shell fiber composites

    International Nuclear Information System (INIS)

    Inamura, Patricia Y.; Shimazaki, Kleber; Moura, Esperidiana Augusta Barretos de; Mastro, Nelida L. del; Colombo, Maria Aparecida; Rosa, Ricardo de

    2010-01-01

    The use of natural fiber as polymeric matrix reinforcement has attracted interest, as fibers are renewable, of low cost, biodegradable and possesses non-toxic properties. In the present paper, Brazil nuts (Bertholletia excelsa) shell fiber (10% w/w) were mixed with gelatin (25% w/w), glycerin as plasticizer and acrylamide as copolymer to investigate the resultant mechanical properties effects upon ionizing radiation. The samples were irradiated at 40 kGy using a Dynamitron electron beam accelerator, at room temperature in the presence of air. The results showed that samples of gelatin with 10% of Brazil nuts shell fiber and irradiated at 40 kGy presented promising results for mechanical performance. (author)

  20. Coating electrospun poly(epsilon-caprolactone) fibers with gelatin and calcium phosphate and their use as biomimetic scaffolds for bone tissue engineering.

    Science.gov (United States)

    Li, Xiaoran; Xie, Jingwei; Yuan, Xiaoyan; Xia, Younan

    2008-12-16

    Electrospinning was employed to fabricate fibrous scaffolds of poly(epsilon-caprolactone) in the form of nonwoven mats. The surfaces of the fibers were then coated with gelatin through layer-by-layer self-assembly, followed by functionalization with a uniform coating of bonelike calcium phosphate by mineralization in the 10 times concentrated simulated body fluid for 2 h. Transmission electron microscopy, water contact angle, and scanning electron microscopy measurements confirmed the presence of gelatin and calcium phosphate coating layers, and X-ray diffraction results suggested that the deposited mineral phase was a mixture of dicalcium phosphate dehydrate (a precursor to apatite) and apatite. It was also demonstrated that the incorporation of gelatin promoted nucleation and growth of calcium phosphate. The porous scaffolds could mimic the structure, composition, and biological function of bone extracellular matrix. It was found that the preosteoblastic MC3T3-E1 cells attached, spread, and proliferated well with a flat morphology on the mineralized scaffolds. The proliferation rate of the cells on the mineralized scaffolds was significantly higher (by 1.9-fold) than that on the pristine fibrous scaffolds after culture for 7 days. These results indicated that the hybrid system containing poly(epsilon-caprolactone), gelatin, and calcium phosphate could serve as a new class of biomimetic scaffolds for bone tissue engineering.

  1. Mechanical characterization of glass fiber (woven roving/chopped strand mat E-glass fiber) reinforced polyester composites

    Science.gov (United States)

    Bhaskar, V. Vijaya; Srinivas, Kolla

    2017-07-01

    Polymer reinforced composites have been replacing most of the engineering material and their applications become more and more day by day. Polymer composites have been analyzing from past thirty five years for their betterment for adapting more applications. This paper aims at the mechanical properties of polyester reinforced with glass fiber composites. The glass fiber is reinforced with polyester in two forms viz Woven Rovings (WRG) and Chopped Strand Mat (CSMG) E-glass fibers. The composites are fabricated by hand lay-up technique and the composites are cut as per ASTM Standard sizes for corresponding tests like flexural, compression and impact tests, so that flexural strength, compression strength, impact strength and inter laminar shear stress(ILSS) of polymer matrix composites are analyzed. From the tests and further calculations, the polyester composites reinforced with Chopped Strand Mat glass fiber have shown better performance against flexural load, compression load and impact load than that of Woven Roving glass fiber.

  2. Relevance of fiber integrated gelatin-nanohydroxyapatite composite scaffold for bone tissue regeneration

    Science.gov (United States)

    Halima Shamaz, Bibi; Anitha, A.; Vijayamohan, Manju; Kuttappan, Shruthy; Nair, Shantikumar; Nair, Manitha B.

    2015-10-01

    Porous nanohydroxyapatite (nanoHA) is a promising bone substitute, but it is brittle, which limits its utility for load bearing applications. To address this issue, herein, biodegradable electrospun microfibrous sheets of poly(L-lactic acid)-(PLLA)-polyvinyl alcohol (PVA) were incorporated into a gelatin-nanoHA matrix which was investigated for its mechanical properties, the physical integration of the fibers with the matrix, cell infiltration, osteogenic differentiation and bone regeneration. The inclusion of sacrificial fibers like PVA along with PLLA and leaching resulted in improved cellular infiltration towards the center of the scaffold. Furthermore, the treatment of PLLA fibers with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide enhanced their hydrophilicity, ensuring firm anchorage between the fibers and the gelatin-HA matrix. The incorporation of PLLA microfibers within the gelatin-nanoHA matrix reduced the brittleness of the scaffolds, the effect being proportional to the number of layers of fibrous sheets in the matrix. The proliferation and osteogenic differentiation of human adipose-derived mesenchymal stem cells was augmented on the fibrous scaffolds in comparison to those scaffolds devoid of fibers. Finally, the scaffold could promote cell infiltration, together with bone regeneration, upon implantation in a rabbit femoral cortical defect within 4 weeks. The bone regeneration potential was significantly higher when compared to commercially available HA (Surgiwear™). Thus, this biomimetic, porous, 3D composite scaffold could be offered as a promising candidate for bone regeneration in orthopedics.

  3. Characterization and Modification of Electrospun Fiber Mats for Use in Composite Proton Exchange Membranes

    Science.gov (United States)

    Mannarino, Matthew Marchand

    Electrostatic fiber formation, or electrospinning, offers a particularly simple and robust method to create polymeric nanofibers of various sizes and morphologies. In electrospinning, a viscoelastic fluid is charged so that a liquid jet is ejected from the surface of the fluid (typically in the form of a drop supplied by a needle or spinneret) and collected on a grounded plate, creating a nonwoven fiber mat. Modification of the diameter of the fibers as well as the porosity, specific surface area, and mechanical properties of the mat allows one to tailor electrospun mats for specific applications. Despite the widespread and rapidly growing use of electrospinning in the fabrication of novel nanomaterials, there are no simple, universal methods of predicting, a priori, the properties of electrospun fibers from knowledge of the polymer solution properties and electrospinning operating conditions alone. Changing a single fluid or processing parameter can affect the jet and fiber formation through several mechanisms. For example, using a different solvent can change several properties of the electrospinning fluid, such as the dielectric constant, conductivity, surface tension, and solute-solvent interaction. The work in this thesis seeks to develop a simple relation for predicting terminal jet diameter during electrospinning, which accounts for solution viscoelasticity as well as solution conductivity and operating parameters that can be easily measured and controlled. The mechanical and tribological properties of electrospun fiber mats are of paramount importance to their utility as components in a variety of applications. Although some mechanical properties of these mats have been investigated previously, reports of their tribological properties are essentially nonexistent. In this thesis, electrospun nanofiber mats of poly(trimethyl hexamethylene terephthalamide) (PA 6(3)T) and poly(hexamethylene adipamide) (PA 6,6) are characterized mechanically and tribologically

  4. Surface modification and micromechanical properties of jute fiber mat reinforced polypropylene composites

    Directory of Open Access Journals (Sweden)

    2007-05-01

    Full Text Available A new treating method using sodium hydroxide (NaOH and Maleic anhydride-grafted polypropylene (MPP emulsion was introduced to treat jute fiber mat in order to enhance the performance of jute/polypropylene (PP composite prepared by film stacking method. The surface modifications of jute fiber mat have been found to be very effective in improving the fiber-matrix adhesion. It was shown that treatments changed not only the surface topography but also the distribution of diameter and strength for the jute fibers, which was analyzed by using a two-parameter Weibull distribution model. Consequently, the interfacial shear strength, flexural and tensile strength of the composites all increased, but the impact strength decreased slightly. These results have demonstrated a new approach to use natural materials to enhance the mechanical performances of composites.

  5. Extraction and electrospinning of gelatin from fish skin.

    Science.gov (United States)

    Songchotikunpan, Panida; Tattiyakul, Jirarat; Supaphol, Pitt

    2008-04-01

    Ultra-fine gelatin fibers were successfully fabricated by electrospinning from the solutions of Nile tilapia (Oreochromis niloticus) skin-extracted gelatin in either acetic acid or formic acid aqueous solutions. The extracted gelatin contained 7.3% moisture, 89.4% protein, 0.3% lipid, and 0.4% ash contents (on the basis of wet weight), while the bloom gel strength, the shear viscosity, and the pH values were 328 g, 17.8 mPa s, and 5.0, respectively. Both the acid concentration and the concentration of the gelatin solutions strongly influenced the properties of the as-prepared solutions and the obtained gelatin fibers. At low acid concentrations (i.e., 15% (w/v) extracted gelatin solutions in 10 and 20% (v/v) acetic acid solvents or 10-60% (v/v) formic acid solvents), a combination between smooth and beaded fibers was observed. At low concentrations of the gelatin solutions in either 40% (v/v) acetic acid solvent or 80% (v/v) formic acid solvent (i.e., 5-11%, w/v), either discrete beads or beaded fibers were obtained, while, at higher concentrations (i.e., 14-29%, w/v), only smooth or a combination of smooth and beaded fibers were obtained. The average diameters of the obtained fibers, regardless of the types of the acid solvents used, ranged between 109 and 761 nm. Lastly, cross-linking of the obtained gelatin fiber mats with glutaraldehyde vapor caused slight shrinkage from their original dimension, and the cross-linked gelatin fiber mats became stiffer.

  6. Carbon nanotube fiber mats for microbial fuel cell electrodes.

    Science.gov (United States)

    Delord, Brigitte; Neri, Wilfrid; Bertaux, Karen; Derre, Alain; Ly, Isabelle; Mano, Nicolas; Poulin, Philippe

    2017-11-01

    Novel carbon nanotube based electrodes of microbial fuel cells (MFC) have been developed. MFC is a promising technology for the wastewater treatment and the production of electrical energy from redox reactions of natural substrates. Performances of such bio-electrochemical systems depend critically on the structure and properties of the electrodes. The presently developed materials are made by weaving fibers solely comprised of carbon nanotubes. They exhibit a large scale porosity controlled by the weaving process. This porosity allows an easy colonization by electroactive bacteria. In addition, the fibers display a nanostructuration that promotes excellent growth and adhesion of the bacteria at the surface of the electrodes. This unique combination of large scale porosity and nanostructuration allows the present electrodes to perform better than carbon reference. When used as anode in a bioelectrochemical reactor in presence of Geobacter sulfurreducens bacteria, the present electrodes show a maximal current density of about 7.5mA/cm 2 . Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Electrospinning of doxorubicin loaded silica/poly(ɛ-caprolactone) hybrid fiber mats for sustained drug release

    Science.gov (United States)

    El Gohary, Mohammed I.; El Hady, Bothaina M. Abd; Saeed, Aziza A. Al; Tolba, Emad; El Rashedi, Ahlam M. I.; Saleh, Safaa

    2018-06-01

    Loading of anticancer drugs into electrospun fiber matrices is a portentous approach for clinical treatment of diseased tissues or organs. In this study, doxorubicin hydrochloride (DOX) is added to silica nanoparticles () during the formation of via the sol-gel approach. The obtained nanoparticles are then added to poly(-caprolactone) (PCL) and poly(ethylene oxide) (PEO) blend before electrospinning process via different methods. The effects of DOX addition as a free form or as nanoparticles on physical and chemical properties of obtained PCL-PEO fibers, as well as release profiles are evaluated to give a continual DOX release for several days. The morphology observed with scanning electron microscope (FESEM) revealed significant changes in the average diameter of obtained fibers ranging from 2164 nm to 659 nm and distribution of drug-loaded nanoparticles in the final mats according to the mode of additions. With the same manner, the releasing performances of obtained mats are quite different. Therefore, fabrication of drug loaded mats would offer a powerful approach to minimize serious side effects for clinical patients and allows us to control the drug concentration in the bloodstream.

  8. Improved cellular infiltration into nanofibrous electrospun cross-linked gelatin scaffolds templated with micrometer-sized polyethylene glycol fibers

    International Nuclear Information System (INIS)

    Skotak, Maciej; Ragusa, Jorge; Gonzalez, Daniela; Subramanian, Anuradha

    2011-01-01

    Gelatin-based nanofibrous scaffolds with a mean fiber diameter of 300 nm were prepared with and without micrometer-sized polyethylene glycol (PEG) fibers that served as sacrificial templates. Upon fabrication of the scaffolds via electrospinning, the gelatin fibers were crosslinked with glutaraldehyde, and the PEG templates were removed using tert-butanol to yield nanofibrous scaffolds with pore diameters ranging from 10 to 100 μm, as estimated with mercury intrusion porosimetry. Non-templated gelatin-based nanofibrous matrices had an average pore size of 1 μm. Fibroblasts were seeded onto both types of the gelatin-based nanofibrous surfaces and cultured for 14 days. For comparative purposes, chitosan-based and polyurethane-based macroporous scaffolds with pore sizes of 100 and 170 μm, respectively, were also included. The number of cells as a function of the depth into the scaffold was judged and quantitatively assessed using nuclei staining. Cell penetration up to a depth of 250 and 90 μm was noted in gelatin scaffolds prepared with sacrificial templates and gelatin-only nanofibrous scaffolds. Noticeably, scaffold preparation protocol presented here allowed the structural integrity to be maintained even with high template content (95%) and can easily be extended toward other classes of electrospun polymer matrices for tissue engineering.

  9. Hierarchical Chitin Fibers with Aligned Nanofibrillar Architectures: A Nonwoven-Mat Separator for Lithium Metal Batteries.

    Science.gov (United States)

    Kim, Joong-Kwon; Kim, Do Hyeong; Joo, Se Hun; Choi, Byeongwook; Cha, Aming; Kim, Kwang Min; Kwon, Tae-Hyuk; Kwak, Sang Kyu; Kang, Seok Ju; Jin, Jungho

    2017-06-27

    Here, we introduce regenerated fibers of chitin (Chiber), the second most abundant biopolymer after cellulose, and propose its utility as a nonwoven fiber separator for lithium metal batteries (LMBs) that exhibits an excellent electrolyte-uptaking capability and Li-dendrite-mitigating performance. Chiber is produced by a centrifugal jet-spinning technique, which allows a simple and fast production of Chibers consisting of hierarchically aligned self-assembled chitin nanofibers. Following the scrutinization on the Chiber-Li-ion interaction via computational methods, we demonstrate the potential of Chiber as a nonwoven mat-type separator by monitoring it in Li-O 2 and Na-O 2 cells.

  10. Mechanical and thermal properties of biocomposites from nonwoven industrial Fique fiber mats with Epoxy Resin and Linear Low Density Polyethylene

    Directory of Open Access Journals (Sweden)

    Miguel A. Hidalgo-Salazar

    2018-03-01

    Full Text Available In this work Linear Low Density Polyethylene-nonwoven industrial Fique fiber mat (LLDPE-Fique and Epoxy Resin-nonwoven industrial Fique fiber mat (EP-Fique biocomposites were prepared using thermocompression and resin film infusion processes. Neat polymeric matrices and its biocomposites were tested following ASTM standards in order to evaluate tensile and flexural mechanical properties. Also, thermal behavior of these materials has been studied by differential scanning calorimetry (DSC and thermogravimetric analysis (TGA. Tensile and flexural test revealed that nonwoven Fique reinforced composites exhibited higher modulus and strength but lower deformation capability as compared with LLDPE and EP neat matrices. TG thermograms showed that nonwoven Fique fibers incorporation has an effect on the thermal stability of the composites. On the other hand, Fique fibers did not change the crystallization and melting processes of the LLDPE matrix but restricts the motion of EP macromolecules chains thus increases the Tg of the EP-Fique composite. Finally, this work opens the possibility of considering non-woven Fique fibers as a reinforcement material with a high potential for the manufacture of biocomposites for automotive applications. In addition to the processing test specimens, it was also possible to manufacture a part of LLDPE-Fique, and one part of EP-Fique. Keywords: Biocomposites, Natural materials, Nonwoven Fique fiber mat, LLDPE, Epoxy Resin

  11. Preparation of a biomimetic composite scaffold from gelatin/collagen and bioactive glass fibers for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Sharifi, Esmaeel; Azami, Mahmoud [Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Kajbafzadeh, Abdol-Mohammad [Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Pediatric Urology Research Center, Section of Tissue Engineering and Stem Cells Therapy, Department of Pediatric Urology, Children' s Hospital Medical Center, Tehran, Iran (IRI) (Iran, Islamic Republic of); Moztarzadeh, Fatollah [Department of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran (Iran, Islamic Republic of); Faridi-Majidi, Reza [Department of Medical Nanotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Shamousi, Atefeh; Karimi, Roya [Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Ai, Jafar, E-mail: jafar_ai@tums.ac.ir [Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Brain and Spinal Injury Research Center (BASIR), Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2016-02-01

    Bone tissue is a composite material made of organic and inorganic components. Bone tissue engineering requires scaffolds that mimic bone nature in chemical and mechanical properties. This study proposes a novel method for preparing composite scaffolds that uses sub-micron bioglass fibers as the organic phase and gelatin/collagen as the inorganic phase. The scaffolds were constructed by using freeze drying and electro spinning methods and their mechanical properties were enhanced by using genipin crosslinking agent. Electron microscopy micrographs showed that the structure of composite scaffolds were porous with pore diameters of approximately 70–200 μm, this was again confirmed by mercury porosimetery. These pores are suitable for osteoblast growth. The diameters of the fibers were approximately 150–450 nm. Structural analysis confirmed the formation of desirable phases of sub-micron bioglass fibers. Cellular biocompatibility tests illustrated that scaffolds containing copper ion in the bioglass structure had more cell growth and osteoblast attachment in comparison to copper-free scaffolds. - Highlights: • Fabrication of 45S5 sub-micron bioglass fiber using electrospinning method. • Production of copper doped submicron bioglass fibers on 45S5 bioglass base by electrospinning sol gel route method. • Incorporation of bioglass/Cu-bioglass sub-micron fibers into gelatin/collagen matrix to form biomimetic composite scaffold which were non-cytotoxic according to MTT assay. • Discovering that copper can decrease the glass transition temperatures and enhance osteoblast cell adhesion and viability.

  12. Preparation of a biomimetic composite scaffold from gelatin/collagen and bioactive glass fibers for bone tissue engineering

    International Nuclear Information System (INIS)

    Sharifi, Esmaeel; Azami, Mahmoud; Kajbafzadeh, Abdol-Mohammad; Moztarzadeh, Fatollah; Faridi-Majidi, Reza; Shamousi, Atefeh; Karimi, Roya; Ai, Jafar

    2016-01-01

    Bone tissue is a composite material made of organic and inorganic components. Bone tissue engineering requires scaffolds that mimic bone nature in chemical and mechanical properties. This study proposes a novel method for preparing composite scaffolds that uses sub-micron bioglass fibers as the organic phase and gelatin/collagen as the inorganic phase. The scaffolds were constructed by using freeze drying and electro spinning methods and their mechanical properties were enhanced by using genipin crosslinking agent. Electron microscopy micrographs showed that the structure of composite scaffolds were porous with pore diameters of approximately 70–200 μm, this was again confirmed by mercury porosimetery. These pores are suitable for osteoblast growth. The diameters of the fibers were approximately 150–450 nm. Structural analysis confirmed the formation of desirable phases of sub-micron bioglass fibers. Cellular biocompatibility tests illustrated that scaffolds containing copper ion in the bioglass structure had more cell growth and osteoblast attachment in comparison to copper-free scaffolds. - Highlights: • Fabrication of 45S5 sub-micron bioglass fiber using electrospinning method. • Production of copper doped submicron bioglass fibers on 45S5 bioglass base by electrospinning sol gel route method. • Incorporation of bioglass/Cu-bioglass sub-micron fibers into gelatin/collagen matrix to form biomimetic composite scaffold which were non-cytotoxic according to MTT assay. • Discovering that copper can decrease the glass transition temperatures and enhance osteoblast cell adhesion and viability.

  13. On the interplay of morphology and electronic conductivity of rotationally spun carbon fiber mats

    Science.gov (United States)

    Opitz, Martin; Go, Dennis; Lott, Philipp; Müller, Sandra; Stollenwerk, Jochen; Kuehne, Alexander J. C.; Roling, Bernhard

    2017-09-01

    Carbon-based materials are used as electrode materials in a wide range of electrochemical applications, e.g., in batteries, supercapacitors, and fuel cells. For these applications, the electronic conductivity of the materials plays an important role. Currently, porous carbon materials with complex morphologies and hierarchical pore structures are in the focus of research. The complex morphologies influence the electronic transport and may lead to an anisotropic electronic conductivity. In this paper, we unravel the influence of the morphology of rotationally spun carbon fiber mats on their electronic conductivity. By combining experiments with finite-element simulations, we compare and evaluate different electrode setups for conductivity measurements. While the "bar-type method" with two parallel electrodes on the same face of the sample yields information about the intrinsic conductivity of the carbon fibers, the "parallel-plate method" with two electrodes on opposite faces gives information about the electronic transport orthogonal to the faces. Results obtained for the van-der-Pauw method suggest that this method is not well suited for understanding morphology-transport relations in these materials.

  14. Glycolysis of carbon fiber-epoxy unidirectional mat catalysed by sodium hydroxide

    Science.gov (United States)

    Zaini, Mariana Binti Mohd; Badri, Khairiah Haji

    2014-09-01

    This study was conducted to recycle carbon fibre-epoxy (CFRP) composite in woven sheet/ mat form. The CFRP was recycled through glycolysis with polyethlyene glycol (PEG 200) as the solvent. The CFRP was loaded into the solvent at a ratio of 4:1 (w/w). PEG200 was diluted with water to a ratio of 80:20 (v/v). This reaction was catalysed by sodium hydroxide (NaOH) solution with varying concentrations at 1.5, 1.7 and 1.9% (w/v). The glycolysis was conducted at 180-190 °C. The recovered CF (rCF) was analysed using Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray (EDX) while the degraded solution was analysed using FTIR and the epoxy content was determined. The FTIR spectrum of the rCF exhibited the disappearance of the COC peak belonged to epoxy and supported by the SEM micrographs that showed clear rCF. On the other hand, the analysed filtrate detected the disappearance of oxygen peak element in the EDX spectrum for all rCF samples. This gave an indication that the epoxy resin has been removed from the surface of the carbon fiber.

  15. Glycolysis of carbon fiber-epoxy unidirectional mat catalysed by sodium hydroxide

    Energy Technology Data Exchange (ETDEWEB)

    Zaini, Mariana Binti Mohd [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Badri, Khairiah Haji [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia and Polymer Research Center, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43 (Malaysia)

    2014-09-03

    This study was conducted to recycle carbon fibre-epoxy (CFRP) composite in woven sheet/ mat form. The CFRP was recycled through glycolysis with polyethlyene glycol (PEG 200) as the solvent. The CFRP was loaded into the solvent at a ratio of 4:1 (w/w). PEG200 was diluted with water to a ratio of 80:20 (v/v). This reaction was catalysed by sodium hydroxide (NaOH) solution with varying concentrations at 1.5, 1.7 and 1.9% (w/v). The glycolysis was conducted at 180-190 °C. The recovered CF (rCF) was analysed using Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray (EDX) while the degraded solution was analysed using FTIR and the epoxy content was determined. The FTIR spectrum of the rCF exhibited the disappearance of the COC peak belonged to epoxy and supported by the SEM micrographs that showed clear rCF. On the other hand, the analysed filtrate detected the disappearance of oxygen peak element in the EDX spectrum for all rCF samples. This gave an indication that the epoxy resin has been removed from the surface of the carbon fiber.

  16. Gelatinous fibers and variant secondary growth related to stem undulation and contraction in a monkey ladder vine, Bauhinia glabra (Fabaceae).

    Science.gov (United States)

    Fisher, Jack B; Blanco, Mario A

    2014-04-01

    Some of the most striking stem shapes occur in species of Bauhinia (Fabaceae) known as monkey ladder vines. Their mature stems are flattened and develop regular undulations. Although stems have variant (anomalous) secondary growth, the mechanism causing the undulations is unknown. We measured stem segments over time (20 mo), described stem development using light microscopy, and correlated the changes in stem shape with anatomy. Growing stems are initially straight and bear tendrils on short axillary branches. The inner secondary xylem has narrow vessels and lignified fibers. As stems age, they become flattened and increasingly undulated with the production of two lobes of outer secondary xylem (OX) with wide vessels and only gelatinous fibers (G-fibers). Similar G-fibers are present in the secondary phloem and the cortical sclerified layer. In transverse sections, the concave side of each undulation has a greater area and quantity of G-fibers than the opposite convex side. Some older stems are not undulated and have less lobing of OX. Undulation causes a shortening of the stem segments: up to 28% of the original length. Uneven distribution of G-fibers produces tensions that are involved in the protracted development of undulations. While young extending shoots attach by lateral branch tendrils, older stems may maintain their position in the canopy using undulations and persistent branch bases as gripping devices. Flattened and undulated stems with G-fibers produce flexible woody stems.

  17. Mechanical and thermal properties of biocomposites from nonwoven industrial Fique fiber mats with Epoxy Resin and Linear Low Density Polyethylene

    Science.gov (United States)

    Hidalgo-Salazar, Miguel A.; Correa, Juan P.

    2018-03-01

    In this work Linear Low Density Polyethylene-nonwoven industrial Fique fiber mat (LLDPE-Fique) and Epoxy Resin-nonwoven industrial Fique fiber mat (EP-Fique) biocomposites were prepared using thermocompression and resin film infusion processes. Neat polymeric matrices and its biocomposites were tested following ASTM standards in order to evaluate tensile and flexural mechanical properties. Also, thermal behavior of these materials has been studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Tensile and flexural test revealed that nonwoven Fique reinforced composites exhibited higher modulus and strength but lower deformation capability as compared with LLDPE and EP neat matrices. TG thermograms showed that nonwoven Fique fibers incorporation has an effect on the thermal stability of the composites. On the other hand, Fique fibers did not change the crystallization and melting processes of the LLDPE matrix but restricts the motion of EP macromolecules chains thus increases the Tg of the EP-Fique composite. Finally, this work opens the possibility of considering non-woven Fique fibers as a reinforcement material with a high potential for the manufacture of biocomposites for automotive applications. In addition to the processing test specimens, it was also possible to manufacture a part of LLDPE-Fique, and one part of EP-Fique.

  18. Forensic identification of trunk mat by trace element analysis of single fiber with laser ablation ICP-MS

    International Nuclear Information System (INIS)

    Hiroma, Yuki; Nakai, Izumi; Hokura, Akiko

    2010-01-01

    The application of LA-ICP-MS (laser ablation inductively coupled plasma mass spectrometry) to the chemical characterization of single trunk mat fibers made of PET was investigated in order to establish a forensic analytical method for the discrimination of samples of different origins. The analytical conditions of LA-ICP-MS equipped with a 213 nm Nd : YAG laser were optimized to analyze trace elements, such as Cu, Sb, and Ba at ppm levels. A total of 31 samples produced by 7 car manufactures in Japan were used for analysis. The concentrations of Li, Mg, Al, P, Ca, Ti, Co, Cu, Ge, Nb, Sb, Ta, and Pb were successfully measured from a single fiber sample with a diameter of ca. 20 μm. It was possible to discriminate all 31 samples based on the analytical results of a single fiber by LA-ICP-MS combined with those of FT-IR and SEM-EDS. LA-ICP-MS has good analytical sensitivity, and requires a much shorter preparation time and a smaller sample size than any other conventional element analysis methods. This paper demonstrates for the first time that this method is practically useful as a powerful tool for the forensic identification of a single trunk mat fiber. (author)

  19. Gelatin-GAG electrospun nanofibrous scaffold for skin tissue engineering: fabrication and modeling of process parameters.

    Science.gov (United States)

    Pezeshki-Modaress, Mohamad; Mirzadeh, Hamid; Zandi, Mojgan

    2015-03-01

    Electrospinning is a very useful technique for producing polymeric nanofibers by applying electrostatic forces. In this study, fabrication of novel gelatin/GAG nanofibrous mats and also the optimization of electrospinning process using response surface methodology were reported. At optimization section, gelatin/GAG blend ratio, applied voltage and feeding rate, their individual and interaction effects on the mean fiber diameter (MFD) and standard deviation of fiber diameter (SDF) were investigated. The obtained model for MFD has a quadratic relationship with gelatin/GAG blend ratio, applied voltage and feeding rate. The interactions of blend ratio and applied voltage and also applied voltage and flow rate were found significant but the interactions of blend ratio and flow rate were ignored. The optimum condition for gelatin/GAG electrospinning was also introduced using the model obtained in this study. The potential use of optimized electrospun mat in skin tissue engineering was evaluated using culturing of human dermal fibroblast cells (HDF). The SEM micrographs of HDF cells on the nanofibrous structure show that fibroblast cells can highly attach, grow and populate on the fabricated scaffold surface. The electrospun gelatin/GAG nanofibrous mats have a potential for using as scaffold for skin, cartilage and cornea tissue engineering. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Improving cytoactive of endothelial cell by introducing fibronectin to the surface of poly L-Lactic acid fiber mats via dopamine

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Wufeng; Zhang, Xiazhi; Wu, Keke; Liu, Xiaoyan; Jiao, Yanpeng, E-mail: tjiaoyp@jnu.edu.cn; Zhou, Changren

    2016-12-01

    A simple but straightforward approach was reported to prepare fiber mats modified with fibronectin (Fn) protein for endothelial cells activity study. Based on the self-polymerization and strong adhesion feature of dopamine, poly L-Lactic acid (PLLA) fibers mat was modified via simply immersing them into dopamine solution for 16 h. Subsequently, Fn was immobilized onto the fiber mats surface by the coupling reactive polydopamine (PDA) layer and Fn. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) were used to determine the chemical compositions of fiber mats surface, which confirmed the successful immobilization of PDA and Fn molecules on the fiber surface. Scanning electronic microscopy (SEM) was used to observe the surface morphology changes after modification with PDA and Fn. The data of water contact angle showed that the hydrophilicity of the fiber mats was improved after surface modification. The data of in vitro cell culture proved that the PDA and Fn modified surface significantly enhanced the adhesion, proliferation and cell activity of endothelial cells on the fiber mats. And the release of tumor necrosis factor-α (TNF-α) by endothelial cells on the modified surface was suppressed compared to that on culture plate and PLLA film at 2 and 4 days, while the secretion of interleukin-1β (IL-1β) was increased compared to that on culture plate and PLLA film at 2 days. - Highlights: • Fibronectin (Fn) was grafted on PLLA fiber surface mediated by polydopamine coating. • Fn modified PLLA fiber enhanced the adhesion, proliferation of endothelial cells. • Fn and polydopamine modified PLLA fiber could adjust the release of inflammatory factor.

  1. 3D carbon fiber mats/nano-Fe3O4 hybrid material with high electromagnetic shielding performance

    Science.gov (United States)

    Zhan, Yingqing; Long, Zhihang; Wan, Xinyi; Zhang, Jiemin; He, Shuangjiang; He, Yi

    2018-06-01

    To obtain high-performance electromagnetic shielding materials, structure and morphology are two key factors. We here developed an efficient and facial method to prepare high-performance 3D carbon nanofiber mats (CFM)/Fe3O4 hybrid electromagnetic shielding materials. For this purpose, the CFM were chemically modified by mussel-inspired poly-dopamine coating, which were further used as templates for decoration of Fe3O4 nanoparticles via solvothermal route. It was found that the Fe3O4 nano-spheres with diameters of 200-250 nm were uniformly coated on the surface of 3D carbon nanofibers. More importantly, the morphology and structure of resulting 3D carbon nanofiber mats/Fe3O4 hybrids could be easily controlled by altering the experiment parameters, which were examined by FT-IR, XPS, TGA, XRD, SEM, and TEM. The measured magnetic properties showed that saturation magnetism and coercivity increased from 13.4 to 39.7 emu/g and 85.3 to 104.6 Oe, respectively. The lowest reflectivity of resulting hybrid was calculated to be -47 dB at 10.0 GHz (2.5 mm). In addition, the reflectivity of 3D carbon nanofiber mats/Fe3O4 hybrid was less than -25 dB in the range of 7-13 GHz. Moreover, the resulting 3D carbon nanofiber mats/Fe3O4 hybrid exhibited an EMI shielding performance of -62.6 dB in the frequency range of 8.2-12.4 GHz. Therefore, 3D carbon fiber mats/Fe3O4 hybrids can be ideal EMI materials with strong absorption, low density, and wide absorption range.

  2. Osteogenesis of human adipose-derived stem cells on poly(dopamine)-coated electrospun poly(lactic acid) fiber mats

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chi-Chang, E-mail: chichang31@thu.edu.tw; Fu, Shu-Juan

    2016-01-01

    Electrospinning is a versatile technique to generate large quantities of micro- or nano-fibers from a wide variety of shapes and sizes of polymer. The aim of this study is to develop functionalized electrospun nano-fibers and use a mussel-inspired surface coating to regulate adhesion, proliferation and differentiation of human adipose-derived stem cells (hADSCs). We prepared poly(lactic acid) (PLA) fibers coated with polydopamine (PDA). The morphology, chemical composition, and surface properties of PDA/PLA were characterized by SEM and XPS. PDA/PLA modulated hADSCs' responses in several ways. Firstly, adhesion and proliferation of hADSCs cultured on PDA/PLA were significantly enhanced relative to those on PLA. Increased focal adhesion kinase (FAK) and collagen I levels and enhanced cell attachment and cell cycle progression were observed upon an increase in PDA content. In addition, the ALP activity and osteocalcin of hADSCs cultured on PDA/PLA were significantly higher than seen in those cultured on a pure PLA mat. Moreover, hADSCs cultured on PDA/PLA showed up-regulation of the ang-1 and vWF proteins associated with angiogenesis differentiation. Our results demonstrate that the bio-inspired coating synthetic degradable PLA polymer can be used as a simple technique to render the surfaces of synthetic biodegradable fibers, thus enabling them to direct the specific responses of hADSCs. - Highlights: • A simple method of preparing electrospun poly(lactic acid) nanofibers coated with polydopamine • Enhanced adhesion and proliferation of hADSCs on a PDA/PLA mat • Increased focal adhesion kinase (FAK), collagen I levels, cell attachment and cell cycle progression with a high PDA content • Up-regulation of the Ang-1 and vWF proteins associated with angiogenesis differentiation of hADSCs is observed. • A promising method for bio-inspired surface modification on organic fiber substrates using PDA.

  3. Osteogenesis of human adipose-derived stem cells on poly(dopamine)-coated electrospun poly(lactic acid) fiber mats

    International Nuclear Information System (INIS)

    Lin, Chi-Chang; Fu, Shu-Juan

    2016-01-01

    Electrospinning is a versatile technique to generate large quantities of micro- or nano-fibers from a wide variety of shapes and sizes of polymer. The aim of this study is to develop functionalized electrospun nano-fibers and use a mussel-inspired surface coating to regulate adhesion, proliferation and differentiation of human adipose-derived stem cells (hADSCs). We prepared poly(lactic acid) (PLA) fibers coated with polydopamine (PDA). The morphology, chemical composition, and surface properties of PDA/PLA were characterized by SEM and XPS. PDA/PLA modulated hADSCs' responses in several ways. Firstly, adhesion and proliferation of hADSCs cultured on PDA/PLA were significantly enhanced relative to those on PLA. Increased focal adhesion kinase (FAK) and collagen I levels and enhanced cell attachment and cell cycle progression were observed upon an increase in PDA content. In addition, the ALP activity and osteocalcin of hADSCs cultured on PDA/PLA were significantly higher than seen in those cultured on a pure PLA mat. Moreover, hADSCs cultured on PDA/PLA showed up-regulation of the ang-1 and vWF proteins associated with angiogenesis differentiation. Our results demonstrate that the bio-inspired coating synthetic degradable PLA polymer can be used as a simple technique to render the surfaces of synthetic biodegradable fibers, thus enabling them to direct the specific responses of hADSCs. - Highlights: • A simple method of preparing electrospun poly(lactic acid) nanofibers coated with polydopamine • Enhanced adhesion and proliferation of hADSCs on a PDA/PLA mat • Increased focal adhesion kinase (FAK), collagen I levels, cell attachment and cell cycle progression with a high PDA content • Up-regulation of the Ang-1 and vWF proteins associated with angiogenesis differentiation of hADSCs is observed. • A promising method for bio-inspired surface modification on organic fiber substrates using PDA

  4. Novel poly(ε-caprolactone)/gelatin wound dressings prepared by emulsion electrospinning with controlled release capacity of Ketoprofen anti-inflammatory drug.

    Science.gov (United States)

    Basar, A O; Castro, S; Torres-Giner, S; Lagaron, J M; Turkoglu Sasmazel, H

    2017-12-01

    In the present study, a single and binary Ketoprofen-loaded mats of ultrathin fibers were developed by electrospinning and their physical properties and drug release capacity was analyzed. The single mat was prepared by solution electrospinning of poly(ε-caprolactone) (PCL) with Ketoprofen at a weight ratio of 5wt%. This Ketoprofen-containing PCL solution was also used as the oil phase in a 7:3 (wt/wt) emulsion with gelatin dissolved in acidified water. The resultant stable oil-in-water (O/W) emulsion of PCL-in-gelatin, also containing Ketoprofen at 5wt%, was electrospun to produce the binary mat. Cross-linking process was performed by means of glutaraldehyde vapor on the electrospun binary mat to prevent dissolution of the hydrophilic gelatin phase. The performed characterization indicated that Ketoprofen was successfully embedded in the single and binary electrospun mats, i.e. PCL and PCL/gelatin, and both mats showed high hydrophobicity but poor thermal resistance. In vitro release studies interestingly revealed that, in comparison to the single PCL electrospun mat, the binary PCL/gelatin mat significantly hindered Ketoprofen burst release and exhibited a sustained release capacity of the drug for up to 4days. In addition, the electrospun Ketoprofen-loaded mats showed enhanced attachment and proliferation of L929 mouse fibroblast cells, presenting the binary mat the highest cell growth yield due to its improved porosity. The here-developed electrospun materials clearly show a great deal of potential as novel wound dressings with an outstanding controlled capacity to release drugs. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Antioxidative study of Cerium Oxide nanoparticle functionalised PCL-Gelatin electrospun fibers for wound healing application

    Directory of Open Access Journals (Sweden)

    Hilal Ahmad Rather

    2018-06-01

    Full Text Available Skin wound healing involves a coordinated cellular response to achieve complete reepithelialisation. Elevated levels of reactive oxygen species (ROS in the wound environment often pose a hindrance in wound healing resulting in impaired wound healing process. Cerium oxide nanoparticles (CeNPs have the ability to protect the cells from oxidative damage by actively scavenging the ROS. Furthermore, matrices like nanofibers have also been explored for enhancing wound healing. In the current study CeNP functionalised polycaprolactone (PCL-gelatin nanofiber (PGNPNF mesh was fabricated by electrospinning and evaluated for its antioxidative potential. Wide angle XRD analysis of randomly oriented nanofibers revealed ∼2.6 times reduced crystallinity than pristine PCL which aided in rapid degradation of nanofibers and release of CeNP. However, bioactive composite made between nanoparticles and PCL-gelatin maintained the fibrous morphology of PGNPNF upto 14 days. The PGNPNF mesh exhibited a superoxide dismutase (SOD mimetic activity due to the incorporated CeNPs. The PGNPNF mesh enhanced proliferation of 3T3-L1 cells by ∼48% as confirmed by alamar blue assay and SEM micrographs of cells grown on the nanofibrous mesh. Furthermore, the PGNPNF mesh scavenged ROS, which was measured by relative DCF intensity and fluorescence microscopy; and subsequently increased the viability and proliferation of cells by three folds as it alleviated the oxidative stress. Overall, the results of this study suggest the potential of CeNP functionalised PCL-gelatin nanofibrous mesh for wound healing applications.

  6. Intrant ELISA: A Novel Approach to Fabrication of Electrospun Fiber Mat-Assisted Biosensor Platforms and Their Integration within Standard Analytical Well Plates

    Directory of Open Access Journals (Sweden)

    Samira Hosseini

    2016-11-01

    Full Text Available A combination of far-field electrospinning (FFES and free-radical polymerization has been used to fabricate coated electrospun polymer fiber mats as a new type of biosensor platform. Poly (3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV electrospun fibers were dip-coated with different compositions of poly methyl methacrylate-co-methacrylic acid (poly(MMA-co-MAA. This synergistic approach utilizes large specific surface area of PHBV fibers and co-polymer coatings that feature an optimum concentration of surface carboxyl (–COOH groups. The platform surface morphology, porosity and tunable hydrophobicity enhance biomolecular interactions via plurality of molecular forces. These customized fiber mats have been integrated into a newly designed 96-well plate called an “intrant enzyme-linked immunosorbent assay” or i-ELISA. I-ELISA allows colorimetric sandwich assay to be carried out without any modifications or additional steps in ELISA methodology. By introducing the fiber mats in fabrication of i-ELISA via extensions on the lid, we address some of the limitations of the previous designs while demonstrating an enhanced signal intensity up to 12 times higher than that of conventional assays. With improved sensitivity, specificity and accuracy in the detection of dengue virus, i-ELISA has proven to be a reliable platform for biomolecular recognition. The proposed fiber mat-assisted well plate in this study holds great potential as a universal approach for integration of different types of fiber mats with pre-designed specific properties in order to enhance the detection sensitivity of the assay.

  7. Preparation of Non-Woven Fiber Mats by Mixture of PVC and Epoxidized Natural Rubber

    International Nuclear Information System (INIS)

    Muhammad Hariz Othman; Mahathir Mohamed; Dahlan Mohd

    2014-01-01

    Eletrospun non-woven fibre mats prepared from ENR modified PVC were successfully fabricated at ambient temperature by electro spinning method. Liquid epoxidized natural rubber (LENR) was used because it is easier to handle compared to dried ENR. PVC was mixed with LENR based on 3 different ratios (9:1, 8:2 and 7:3). The effect of ENR on electrospinnibality of PVC was investigated.The morphologies and thermal properties of the electro span fibre mats were characterized and assessed using scanning calorimetry (DSC). The polymer solution concentration 16 aut % formed a diameter of the fibres were mainly affected by the addition of natural rubber and weight ratio of the solution. The diameter of the fibres also decreased with increasing amount of LENR in the solution. Thermal degradation involved two-step degradation with the first degradation representing the dehydro chlorination of PVC to form polyene and followed by the decomposition of LENR and the polyene.Addition of LENR into the sample caused the T g of electro spun fibre mats of PVC/LENR to shift toward lower temperature. (author)

  8. Fiber webs

    Science.gov (United States)

    Roger M. Rowell; James S. Han; Von L. Byrd

    2005-01-01

    Wood fibers can be used to produce a wide variety of low-density three-dimensional webs, mats, and fiber-molded products. Short wood fibers blended with long fibers can be formed into flexible fiber mats, which can be made by physical entanglement, nonwoven needling, or thermoplastic fiber melt matrix technologies. The most common types of flexible mats are carded, air...

  9. Constitutive modelling of creep in a long fiber random glass mat thermoplastic composite

    Science.gov (United States)

    Dasappa, Prasad

    The primary objective of this proposed research is to characterize and model the creep behaviour of Glass Mat Thermoplastic (GMT) composites under thermo-mechanical loads. In addition, tensile testing has been performed to study the variability in mechanical properties. The thermo-physical properties of the polypropylene matrix including crystallinity level, transitions and the variation of the stiffness with temperature have also been determined. In this work, the creep of a long fibre GMT composite has been investigated for a relatively wide range of stresses from 5 to 80 MPa and temperatures from 25 to 90°C. The higher limit for stress is approximately 90% of the nominal tensile strength of the material. A Design of Experiments (ANOVA) statistical method was applied to determine the effects of stress and temperature in the random mat material which is known for wild experimental scatter. Two sets of creep tests were conducted. First, preliminary short-term creep tests consisting of 30 minutes creep followed by recovery were carried out over a wide range of stresses and temperatures. These tests were carried out to determine the linear viscoelastic region of the material. From these tests, the material was found to be linear viscoelastic up-to 20 MPa at room temperature and considerable non-linearities were observed with both stress and temperature. Using Time-Temperature superposition (TTS) a long term master curve for creep compliance for up-to 185 years at room temperature has been obtained. Further, viscoplastic strains were developed in these tests indicating the need for a non-linear viscoelastic viscoplastic constitutive model. The second set of creep tests was performed to develop a general non-linear viscoelastic viscoplastic constitutive model. Long term creep-recovery tests consisting of 1 day creep followed by recovery has been conducted over the stress range between 20 and 70 MPa at four temperatures: 25°C, 40°C, 60°C and 80°C. Findley's model

  10. Fish gelatin.

    Science.gov (United States)

    Boran, Gokhan; Regenstein, Joe M

    2010-01-01

    Gelatin is a multifunctional ingredient used in foods, pharmaceuticals, cosmetics, and photographic films as a gelling agent, stabilizer, thickener, emulsifier, and film former. As a thermoreversible hydrocolloid with a narrower gap between its melting and gelling temperatures, both of which are below human body temperature, gelatin provides unique advantages over carbohydrate-based gelling agents. Gelatin is mostly produced from pig skin, and cattle hides and bones. Some alternative raw materials have recently gained attention from both researchers and the industry not just because they overcome religious concerns shared by Jews and Muslims but also because they provide, in some cases, technological advantages over mammalian gelatins. Fish skins from a number of fish species are among the other sources that have been comprehensively studied as sources for gelatin production. Fish skins have a significant potential for the production of high-quality gelatin with different melting and gelling temperatures over a much wider range than mammalian gelatins, yet still have a sufficiently high gel strength and viscosity. Gelatin quality is industrially determined by gel strength, viscosity, melting or gelling temperatures, the water content, and microbiological safety. For gelatin manufacturers, yield from a particular raw material is also important. Recent experimental studies have shown that these quality parameters vary greatly depending on the biochemical characteristics of the raw materials, the manufacturing processes applied, and the experimental settings used for quality control tests. In this review, the gelatin quality achieved from different fish species is reviewed along with the experimental procedures used to determine gelatin quality. In addition, the chemical structure of collagen and gelatin, the collagen-gelatin conversion, the gelation process, and the gelatin market are discussed. Copyright © 2010 Elsevier Inc. All rights reserved.

  11. Role of solvent-mediated carbodiimide cross-linking in fabrication of electrospun gelatin nanofibrous membranes as ophthalmic biomaterials

    International Nuclear Information System (INIS)

    Chou, Shih-Feng; Luo, Li-Jyuan; Lai, Jui-Yang; Ma, David Hui-Kang

    2017-01-01

    Due to their ability to mimic the structure of extracellular matrix, electrospun gelatin nanofibers are promising cell scaffolding materials for tissue engineering applications. However, the hydrophilic gelatin molecules usually need stabilization before use in aqueous physiological environment. Considering that biomaterials cross-linked via film immersion technique may have a more homogeneous cross-linked structure than vapor phase cross-linking, this work aims to investigate the chemical modification of electrospun gelatin nanofibrous membranes by liquid phase carbodiimide in the presence of ethanol/water co-solvents with varying ethanol concentrations ranging from 80 to 99.5 vol%. The results of characterization showed that increasing water content in the binary reaction solvent system increases the extent of cross-linking of gelatin nanofibers, but simultaneously promotes the effect of biopolymer swelling and distortion in fiber mat structure. As compared to non-cross-linked counterparts, carbodiimide treated gelatin nanofibrous mats exhibited better thermal and biological stability where the shrinkage temperature and resistance to enzymatic degradation varied in response to ethanol/water solvent composition-mediated generation of cross-links. Irrespective of their cross-linking density, all studied membrane samples did not induce any responses in ocular epithelial cell cultures derived from cornea, lens, and retina. Unlike many other cross-linking agents and/or methods (e.g., excessive vapor phase cross-linking) that may pose a risk of toxicity, our study demonstrated that these nanofibrous materials are well tolerated by anterior segment tissues. These findings also indicate the safety of using ethanol/water co-solvents for chemical cross-linking of gelatin to engineer nanofibrous materials with negligible biological effects. In summary, the present results suggest the importance of solvent-mediated carbodiimide cross-linking in modulating structure

  12. Role of solvent-mediated carbodiimide cross-linking in fabrication of electrospun gelatin nanofibrous membranes as ophthalmic biomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Shih-Feng [Department of Mechanical Engineering, University of Texas at Tyler, Tyler, TX 75799 (United States); Luo, Li-Jyuan [Department of Chemical and Materials Engineering, Chang Gung University, Taoyuan 33302, Taiwan, ROC (China); Lai, Jui-Yang, E-mail: jylai@mail.cgu.edu.tw [Institute of Biochemical and Biomedical Engineering, Chang Gung University, Taoyuan 33302, Taiwan, ROC (China); Biomedical Engineering Research Center, Chang Gung University, Taoyuan 33302, Taiwan, ROC (China); Center for Tissue Engineering, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan, ROC (China); Department of Ophthalmology, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan, ROC (China); Department of Materials Engineering, Ming Chi University of Technology, New Taipei City 24301, Taiwan, ROC (China); Ma, David Hui-Kang [Center for Tissue Engineering, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan, ROC (China); Department of Ophthalmology, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan, ROC (China); Department of Chinese Medicine, Chang Gung University, Taoyuan 33302, Taiwan, ROC (China)

    2017-02-01

    Due to their ability to mimic the structure of extracellular matrix, electrospun gelatin nanofibers are promising cell scaffolding materials for tissue engineering applications. However, the hydrophilic gelatin molecules usually need stabilization before use in aqueous physiological environment. Considering that biomaterials cross-linked via film immersion technique may have a more homogeneous cross-linked structure than vapor phase cross-linking, this work aims to investigate the chemical modification of electrospun gelatin nanofibrous membranes by liquid phase carbodiimide in the presence of ethanol/water co-solvents with varying ethanol concentrations ranging from 80 to 99.5 vol%. The results of characterization showed that increasing water content in the binary reaction solvent system increases the extent of cross-linking of gelatin nanofibers, but simultaneously promotes the effect of biopolymer swelling and distortion in fiber mat structure. As compared to non-cross-linked counterparts, carbodiimide treated gelatin nanofibrous mats exhibited better thermal and biological stability where the shrinkage temperature and resistance to enzymatic degradation varied in response to ethanol/water solvent composition-mediated generation of cross-links. Irrespective of their cross-linking density, all studied membrane samples did not induce any responses in ocular epithelial cell cultures derived from cornea, lens, and retina. Unlike many other cross-linking agents and/or methods (e.g., excessive vapor phase cross-linking) that may pose a risk of toxicity, our study demonstrated that these nanofibrous materials are well tolerated by anterior segment tissues. These findings also indicate the safety of using ethanol/water co-solvents for chemical cross-linking of gelatin to engineer nanofibrous materials with negligible biological effects. In summary, the present results suggest the importance of solvent-mediated carbodiimide cross-linking in modulating structure

  13. Effect of natural fiber types and sodium silicate coated on natural fiber mat/PLA composites: Tensile properties and rate of fire propagation

    Science.gov (United States)

    Thongpin, C.; Srimuk, J.; hipkam, N.; Wachirapong, P.

    2015-07-01

    In this study, 3 types of natural fibres, i.e. jute, sisal and abaca, were plain weaved to fibre mat. Before weaving, the fibres were treated with 5% NaOH to remove hemi cellulose and lignin. The weaving was performed by hand using square wooden block fit with nails for weaving using one and two types of natural fibres as weft and warp fibre to produce natural fibre mat. The fibre mat was also impregnated in sodium silicate solution extracted from rich husk ash. The pH of the solution was adjusted to pH 7 using H2SO4 before impregnation. After predetermined time, sodium silicate was gelled and deposited on the mat. The fabric mat and sodium silicate coated mat were then impregnated with PLA solution to produce prepreg. Dried pepreg was laminated with PLA sheet using compressing moulding machine to obtain natural fibre mat/PLA composite. The composite containing abaca aligned in longitudinal direction with respect to tension force enhanced Young's modulus more than 300%. Fibre mat composites with abaca aligned in longitudinal direction also showed tensile strength enhancement nearly 400% higher than neat PLA. After coating with sodium silicate, the tensile modulus of the composites was found slightly increased. The silicate coating was disadvantage on tensile strength of the composite due to the effect of sodium hydroxide solution that was used as solvent for silicate extraction from rice husk ash. However, sodium silicate could retard rate of fire propagation about 50%compare to neat PLA and about 10% reduction compared to fibre mat composites without sodium silicate coated fibre mat.

  14. Effect of natural fiber types and sodium silicate coated on natural fiber mat/PLA composites: Tensile properties and rate of fire propagation

    International Nuclear Information System (INIS)

    Thongpin, C; Srimuk, J; Hipkam, N; Wachirapong, P

    2015-01-01

    In this study, 3 types of natural fibres, i.e. jute, sisal and abaca, were plain weaved to fibre mat. Before weaving, the fibres were treated with 5% NaOH to remove hemi cellulose and lignin. The weaving was performed by hand using square wooden block fit with nails for weaving using one and two types of natural fibres as weft and warp fibre to produce natural fibre mat. The fibre mat was also impregnated in sodium silicate solution extracted from rich husk ash. The pH of the solution was adjusted to pH 7 using H 2 SO 4 before impregnation. After predetermined time, sodium silicate was gelled and deposited on the mat. The fabric mat and sodium silicate coated mat were then impregnated with PLA solution to produce prepreg. Dried pepreg was laminated with PLA sheet using compressing moulding machine to obtain natural fibre mat/PLA composite. The composite containing abaca aligned in longitudinal direction with respect to tension force enhanced Young's modulus more than 300%. Fibre mat composites with abaca aligned in longitudinal direction also showed tensile strength enhancement nearly 400% higher than neat PLA. After coating with sodium silicate, the tensile modulus of the composites was found slightly increased. The silicate coating was disadvantage on tensile strength of the composite due to the effect of sodium hydroxide solution that was used as solvent for silicate extraction from rice husk ash. However, sodium silicate could retard rate of fire propagation about 50%compare to neat PLA and about 10% reduction compared to fibre mat composites without sodium silicate coated fibre mat. (paper)

  15. Method for production of carbon nanofiber mat or carbon paper

    Science.gov (United States)

    Naskar, Amit K.

    2015-08-04

    Method for the preparation of a non-woven mat or paper made of carbon fibers, the method comprising carbonizing a non-woven mat or paper preform (precursor) comprised of a plurality of bonded sulfonated polyolefin fibers to produce said non-woven mat or paper made of carbon fibers. The preforms and resulting non-woven mat or paper made of carbon fiber, as well as articles and devices containing them, and methods for their use, are also described.

  16. Antibacterial and Barrier Properties of Gelatin Coated by Electrospun Polycaprolactone Ultrathin Fibers Containing Black Pepper Oleoresin of Interest in Active Food Biopackaging Applications

    Directory of Open Access Journals (Sweden)

    Kelly Johana Figueroa-Lopez

    2018-03-01

    Full Text Available The present study evaluated the effect of using electrospun polycaprolactone (PCL as a barrier coating and black pepper oleoresin (OR as a natural extract on the morphology, thermal, mechanical, antimicrobial, oxygen, and water vapor barrier properties of solvent cast gelatin (GEL. The antimicrobial activity of the developed multilayer system obtained by the so-called electrospinning coating technique was also evaluated against Staphylococcus aureus strains for 10 days. The results showed that the multilayer system containing PCL and OR increased the thermal resistance, elongated the GEL film, and significantly diminished its permeance to water vapor. Active multilayer systems stored in hermetically closed bottles increased their antimicrobial activity after 10 days by inhibiting the growth of Staphylococcus aureus. This study demonstrates that addition of electrospun PCL ultrathin fibers and OR improved the properties of GEL films, which promoted its potential use in active food packaging applications.

  17. Conductivity and touch-sensor application for atomic layer deposition ZnO and Al:ZnO on nylon nonwoven fiber mats

    International Nuclear Information System (INIS)

    Sweet, William J.; Oldham, Christopher J.; Parsons, Gregory N.

    2015-01-01

    Flexible electronics and wearable technology represent a novel and growing market for next generation devices. In this work, the authors deposit conductive zinc oxide films by atomic layer deposition onto nylon-6 nonwoven fiber mats and spun-cast films, and quantify the impact that deposition temperature, coating thickness, and aluminum doping have on the conductivity of the coated substrates. The authors produce aluminum doped zinc oxide (AZO) coated fibers with conductivity of 230 S/cm, which is ∼6× more conductive than ZnO coated fibers. Furthermore, the authors demonstrate AZO coated fibers maintain 62% of their conductivity after being bent around a 3 mm radius cylinder. As an example application, the authors fabricate an “all-fiber” pressure sensor using AZO coated nylon-6 electrodes. The sensor signal scales exponentially under small applied force (<50 g/cm 2 ), yielding a ∼10 6 × current change under 200 g/cm 2 . This lightweight, flexible, and breathable touch/force sensor could function, for example, as an electronically active nonwoven for personal or engineered system analysis and diagnostics

  18. Talking Mats

    DEFF Research Database (Denmark)

    2012-01-01

    Talking Mats are visualizations in the handy size of a set of cards used to support interviews with people with mental disabilities.......Talking Mats are visualizations in the handy size of a set of cards used to support interviews with people with mental disabilities....

  19. Chitinase-like (CTL) and cellulose synthase (CESA) gene expression in gelatinous-type cellulosic walls of flax (Linum usitatissimum L.) bast fibers.

    Science.gov (United States)

    Mokshina, Natalia; Gorshkova, Tatyana; Deyholos, Michael K

    2014-01-01

    Plant chitinases (EC 3.2.1.14) and chitinase-like (CTL) proteins have diverse functions including cell wall biosynthesis and disease resistance. We analyzed the expression of 34 chitinase and chitinase-like genes of flax (collectively referred to as LusCTLs), belonging to glycoside hydrolase family 19 (GH19). Analysis of the transcript expression patterns of LusCTLs in the stem and other tissues identified three transcripts (LusCTL19, LusCTL20, LusCTL21) that were highly enriched in developing bast fibers, which form cellulose-rich gelatinous-type cell walls. The same three genes had low relative expression in tissues with primary cell walls and in xylem, which forms a xylan type of secondary cell wall. Phylogenetic analysis of the LusCTLs identified a flax-specific sub-group that was not represented in any of other genomes queried. To provide further context for the gene expression analysis, we also conducted phylogenetic and expression analysis of the cellulose synthase (CESA) family genes of flax, and found that expression of secondary wall-type LusCESAs (LusCESA4, LusCESA7 and LusCESA8) was correlated with the expression of two LusCTLs (LusCTL1, LusCTL2) that were the most highly enriched in xylem. The expression of LusCTL19, LusCTL20, and LusCTL21 was not correlated with that of any CESA subgroup. These results defined a distinct type of CTLs that may have novel functions specific to the development of the gelatinous (G-type) cellulosic walls.

  20. Microbial communities and exopolysaccharides from Polynesian mats.

    Science.gov (United States)

    Rougeaux, H; Guezennec, M; Che, L M; Payri, C; Deslandes, E; Guezennec, J

    2001-03-01

    Microbial mats present in two shallow atolls of French Polynesia were characterized by high amounts of exopolysaccharides associated with cyanobacteria as the predominating species. Cyanobacteria were found in the first centimeters of the gelatinous mats, whereas deeper layers showing the occurrence of the sulfate reducers Desulfovibrio and Desulfobacter species as determined by the presence of specific biomarkers. Exopolysaccharides were extracted from these mats and partially characterized. All fractions contained both neutral sugars and uronic acids with a predominance of the former. The large diversity in monosaccharides can be interpreted as the result of exopolymer biosynthesis by either different or unidentified cyanobacterial species.

  1. PERMEABILITY REDUCTION PHENOMENA IN PACKED BEDS, FIBER MATS, AND WET WEBS OF PAPER EXPOSED TO FLOW OF LIQUIDS AND SUSPENSIONS: A REVIEW

    Directory of Open Access Journals (Sweden)

    Martin A. Hubbe

    2009-02-01

    Full Text Available Filter media, including those prepared from cellulosic materials, often suffer from permeability loss during continued use. To help understand such issues, one can take advantage of an extensive body of related research in such fields as industrial filtration, water purification, enhanced oil recovery, chromatography, paper manufacture, and the leaching of pollutants from impoundments. Though the mechanisms that appear to govern permeability-loss phenomena depend a lot on the details of various applications, the published research has revealed a number of common features. In particular, flow through a porous bed or fiber mat can be markedly reduced by deposition of particles or colloidal matter in positions that either block or partially restrict fluid flow. Progress has been achieved in the development of mechanistic models, as well as the use of such models in numerical simulations to explain various experimental findings. Further research of this type needs to be applied to cellulosic materials, which tend to be much more elongated in comparison to the bed materials and suspended matter considered most often by most researchers active in research related to permeability loss.

  2. Differences in cytocompatibility between collagen, gelatin and keratin

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yanfang; Zhang, Weiwei; Yuan, Jiang, E-mail: jyuan@njnu.edu.cn; Shen, Jian, E-mail: jshen@njnu.edu.cn

    2016-02-01

    Keratins are cysteine-rich intermediate filament proteins found in the cytoskeleton of the epithelial cells and in the matrix of hair, feathers, wool, nails and horns. The natural abundance of cell adhesion sequences, RGD (Arg-Gly-Asp) and LDV (Leu-Asp-Val), makes them suitable for tissue engineering applications. The purpose of our study is to evaluate their cytocompatibility as compared to well-known collagen and gelatin proteins. Herein, collagen, gelatin and keratin were blended with poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and electrospun to afford nanofibrous mats, respectively. These PHBV/protein composite mats were characterized by field emission scanning electron microscopy (FE-SEM), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), and dynamic mechanical analysis (DMA). The cytocompatibility was evaluated with cell adhesion, cell viability and cell proliferation. The data from MTT and BrDU revealed that collagen had significantly superior cytocompatibility as compared to gelatin and keratin. Gelatin showed a better cytocompatibility than keratin without statistical significance difference. Finally, we gave the reasons to account for the above conclusions. - Highlights: • Collagen, gelatin and keratin were coelectrospun with PHBV to afford nanofibrous mats. • Cytocompatibility was evaluated with cell adhesion, cell viability and cell proliferation. • Collagen had significantly superior cytocompatibility as compared to gelatin and keratin.

  3. Gelatin/piassava composites treated by Electron Beam Radiation

    International Nuclear Information System (INIS)

    Takinami, Patricia Yoko Inamura; Shimazaki, Kleber; Moura, Esperidiana Augusta Barretos de; Mastro, Nelida Lucia del; Colombo, Maria Aparecida

    2010-01-01

    Piassava (Attalea funifera Mart) fiber has been investigated as reinforcement for polymer composites with potential for practical applications. The purpose of the present work was to assess the behavior of specimens of piassava fiber and gelatin irradiated with electron beam at different doses and percentage. The piassava/gelatin specimens were made with 5 and 10% (w/w) piassava fiber, gelatin 25% (w/w), glycerin as plasticizer and acrylamide as copolymer. The samples were irradiated up to 40 kGy using an electron beam accelerator, at room temperature in presence of air. Preliminary results showed mechanical properties enhancement with the increase in radiation dose. (author)

  4. Formulating gelatin free products

    NARCIS (Netherlands)

    Buwalda, P.L.

    2014-01-01

    Gels are applied in many systems in particular in foods. Gelatin is the most common of all gelling agents. In the food industry there is a long quest for replacing gelatin. This chapter focuses on a more application by application approach where a dominant property of gelatin is matched with a

  5. Graphene oxide decorated electrospun gelatin nanofibers: Fabrication, properties and applications

    Energy Technology Data Exchange (ETDEWEB)

    Jalaja, K. [Department of Chemistry, Indian Institute of Space Science and Technology, Valiamala, Thiruvananthapuram, Kerala 695 547 (India); Sreehari, V.S. [Indian Institute of Science Education and Research Bhopal, Bhauri, Madhya Pradesh 462066 (India); Kumar, P.R. Anil [Tissue culture laboratory, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Poojappura, Thiruvananthapuram, Kerala 695 012 (India); Nirmala, R. James, E-mail: nirmala@iist.ac.in [Department of Chemistry, Indian Institute of Space Science and Technology, Valiamala, Thiruvananthapuram, Kerala 695 547 (India)

    2016-07-01

    Gelatin nanofiber fabricated by electrospinning process is found to mimic the complex structural and functional properties of natural extracellular matrix for tissue regeneration. In order to improve the physico-chemical and biological properties of the nanofibers, graphene oxide is incorporated in the gelatin to form graphene oxide decorated gelatin nanofibers. The current research effort is focussed on the fabrication and evaluation of physico-chemical and biological properties of graphene oxide-gelatin composite nanofibers. The presence of graphene oxide in the nanofibers was established by transmission electron microscopy (TEM). We report the effect of incorporation of graphene oxide on the mechanical, thermal and biological performance of the gelatin nanofibers. The tensile strength of gelatin nanofibers was increased from 8.29 ± 0.53 MPa to 21 ± 2.03 MPa after the incorporation of GO. In order to improve the water resistance of nanofibers, natural based cross-linking agent, namely, dextran aldehyde was employed. The cross-linked composite nanofibers showed further increase in the tensile strength up to 56.4 ± 2.03 MPa. Graphene oxide incorporated gelatin nanofibers are evaluated for bacterial activity against gram positive (Staphylococcus aureus) and gram negative (Escherichia coli) bacteria and cyto compatibility using mouse fibroblast cells (L-929 cells). The results indicate that the graphene oxide incorporated gelatin nanofibers do not prevent bacterial growth, nevertheless support the L-929 cell adhesion and proliferation. - Highlights: • Graphene oxide nano reinforced gelatin nanofibers are fabricated by electrospinning. • Graphene oxide (0.5%) loading resulted in increased tensile strength. • GO/gelatin nanofibers are cross-linked with dextran aldehyde. • Composite nanofibers favoured adhesion of L-929 cells. • GO/gelatin mats do not prevent bacterial growth.

  6. In situ dry matter and fiber fraction degradability of the Mineirão stylos=Degradabilidade in situ da matéria seca e fração fibrosa do estilosantes Mineirão

    Directory of Open Access Journals (Sweden)

    Domingas Cruvinel Batista de Siqueira

    2012-04-01

    Full Text Available This research evaluated, using the in situ technique, the dry matter and fiber fraction degradability of the Mineirão stylo (Stylozanthes guianensis. The nylon bag method was used for the degradability assay, with two incubations in rumen-cannulated adult female cows. In each incubation, 25 samples of 7.0 g each were used. The samples were collected at 0, 6, 9, 12, 24, 36, 48, 72 and 96 hours. The experiment was conducted according to a randomized blocks design and data were submitted to analysis of variance. The maximum effective degradability was obtained in the 2% passage rate. For the 5% passage rate the Mineirão stylo showed effective degradation of 75.70% for dry matter, 59.01% for neutral detergent fiber and 76.81% for acid detergent fiber. The digestibility achieved by the dry matter and fibrous fraction from Mineirão was considered high. These results, coupled with the low lag time found reveal the forage potential of the cultivar.Neste trabalho avaliou-se, por meio da técnica in situ, a degradabilidade da matéria seca e da fração fibrosa da leguminosa estilosantes Mineirão (Stylozanthes guianensis, leguminosa nativa do Cerrado brasileiro. Para o ensaio da degradabilidade, usou-se o método dos sacos de náilon, com duas incubações em fêmea bovina adulta canulada no rúmen. Em cada incubação, foram utilizadas 25 amostras de 7,0 g cada. As amostras foram retiradas nos tempos 0, 6, 9, 12, 24, 36, 48, 72 e 96h. O experimento foi conduzido segundo o delineamento de blocos ao acaso e os dados submetidos à analise de variância. As máximas degradabilidades efetivas foram atingidas na taxa de passagem 2%. Para a taxa de passagem de 5%, o estilosantes Mineirão apresentou degradabilidade efetiva de 75,70% para a matéria seca, 59,01% para a fibra em detergente neutro e 76,81% para a fibra em detergente ácido. A digestibilidade alcançada tanto pela matéria seca quanto pela fração fibrosa estilosantes Mineirão foi considerada

  7. Development of kenaf mat for slope stabilization

    Science.gov (United States)

    Ahmad, M. M.; Manaf, M. B. H. Ab; Zainol, N. Z.

    2017-09-01

    This study focusing on the ability of kenaf mat to act as reinforcement to laterite compared to the conventional geosynthetic in term of stabilizing the slope. Kenaf mat specimens studied in this paper are made up from natural kenaf fiber with 3mm thickness, 150mm length and 20mm width. With the same size of specimens, geosynthetic that obtain from the industry are being tested for both direct shear and tensile tests. Plasticity index of the soil sample used is equal to 13 which indicate that the soil is slightly plastic. Result shows that the friction angle of kenaf mat is higher compared to friction between soil particles itself. In term of resistance to tensile load, the tensile strength of kenaf mat is 0.033N/mm2 which is lower than the tensile strength of geosynthetic.

  8. OPTIMIZATION OF MARSHMALLOW GELATIN FUNCTIONAL PURPOSE

    Directory of Open Access Journals (Sweden)

    G. O. Magomedov

    2015-01-01

    Full Text Available Marshmallow on gelatin or marshmallow items finely porous foam structure. This product is a popular and widely demanded confectionery products to the public, especially children and students. Urgent by the NE-a method for producing a mini-marshmallow functionality in terms of domestic production with natural-functional ingredient – gum-arabic «Instantgum», which is the source of natural-fiber, improving gastrointestinal function, lowering blood glucose levels that especially important in the use of products of diabetics. The inclusion of gum-arabic in the diet leads to a prebiotic effect, stimulating human immune system and improves the functioning intestines. Technology mini marshmallow gelatin with gum-arabic comprises the following manufacturing steps of: preparing a gelatin solution, an aqueous solution of gum-arabic, sugar syrup, invert syrup, whipped gelatinous mass density of 400-600 kg / m3, molding or pressing off mass fractionation followed by cooling and cutting, exposure and dusting starch and sugar mixture housings mini marshmallows. The optimization formulation mini marshmallows on gelatin with functional ingredients «Instantgum» based on gum-arabic method of multicriteria optimization of op-using desirability function Harrington. The greatest value generalized desirability function had a sample with 10% in-functional ingredient, since it belongs to the best set of parameters optimization. The developed product has high organoleptic, physical and chemical parameters, satisfactory form-retaining ability elastic chewing consistency and a functional purpose by NIJ-containing dietary fiber. Proposed can be recommended for the production on-time with continuous mechanized lines to develop Pastila products.

  9. Irradiation of gelatin. Important applications for the development of new materials

    Energy Technology Data Exchange (ETDEWEB)

    Del Mastro, N. L., E-mail: nlmastro@ipen.br [Instituto de Pesquisas Energeticas e Nucleares IPEN-CNEN/SP, Av. Prof. Lineu Prestes 2242, 05008-900 Sao Paulo (Brazil)

    2011-11-15

    Gelatin is obtained from a naturally occurring protein, collagen, by chemical and thermal hydrolysis. As a protein, gelatin is biodegradable. Among biomaterials, gelatin is an interesting material because the dehydrated gelatin is a partially crystalline polymer and has a relatively low melting point. Gelatin melts to a liquid when heated and solidifies when cooled again. Together with water, it forms a semi-solid colloid gel. If gelatin is placed in contact with cold water, some of the material dissolves, their solubility being determined by their manufacturing method. Ionizing radiation acting on aqueous biological systems produces labile intermediates. Macromolecular free radicals may be diffusion ally mobile in homogenous solutions but relatively immobile in gelled systems. In this paper, different works, some of them performed in our laboratory, are firstly described showing gelatin irradiation in diverse systems. We have already studied the mechanical properties of gelatin composites prepared with a natural fiber, plasticizer and treated by electron beam irradiation. Departing from that, the range of novel applications for gelatin composites like gelatin nanoparticles as biodegradable s and low cell toxic alternative carrier delivery systems are outlined. The potential and the possibilities of using gelatin irradiation for important applications for the development of new materials for medical and food industry are presented. (Author)

  10. Transplantation of artificial gelatin-co-bletillastriata gelatin/ Salvia ...

    African Journals Online (AJOL)

    Purpose: To evaluate the growth of the composite corium (constructed with fibroblast cells and gelatinco- Bletillastriata gelatin/Salvia miltiorrhiza materials) on rats. Methods: The composite artificial corium was constructed by culturing fibroblast cells in gelatin-co- Bletillastriata gelatin/Salvia miltiorrhiza materials.

  11. Electrospun chitosan-based nanocomposite mats reinforced with chitin nanocrystals for wound dressing

    CSIR Research Space (South Africa)

    Naseria, N

    2014-08-01

    Full Text Available The aim of this study was to develop electrospun chitosan/polyethylene oxide-based randomly oriented fiber mats reinforced with chitin nanocrystals (ChNC) for wound dressing. Microscopy studies showedporous mats of smooth and beadless fibers...

  12. Comparison of cell behavior on pva/pva-gelatin electrospun nanofibers with random and aligned configuration

    Science.gov (United States)

    Huang, Chen-Yu; Hu, Keng-Hsiang; Wei, Zung-Hang

    2016-12-01

    Electrospinning technique is able to create nanofibers with specific orientation. Poly(vinyl alcohol) (PVA) have good mechanical stability but poor cell adhesion property due to the low affinity of protein. In this paper, extracellular matrix, gelatin is incorporated into PVA solution to form electrospun PVA-gelatin nanofibers membrane. Both randomly oriented and aligned nanofibers are used to investigate the topography-induced behavior of fibroblasts. Surface morphology of the fibers is studied by optical microscopy and scanning electron microscopy (SEM) coupled with image analysis. Functional group composition in PVA or PVA-gelatin is investigated by Fourier Transform Infrared (FTIR). The morphological changes, surface coverage, viability and proliferation of fibroblasts influenced by PVA and PVA-gelatin nanofibers with randomly orientated or aligned configuration are systematically compared. Fibroblasts growing on PVA-gelatin fibers show significantly larger projected areas as compared with those cultivated on PVA fibers which p-value is smaller than 0.005. Cells on PVA-gelatin aligned fibers stretch out extensively and their intracellular stress fiber pull nucleus to deform. Results suggest that instead of the anisotropic topology within the scaffold trigger the preferential orientation of cells, the adhesion of cell membrane to gelatin have substantial influence on cellular behavior.

  13. Extraction and characterization of gelatin biopolymer from black tilapia (Oreochromis mossambicus) scales

    Science.gov (United States)

    Sockalingam, K.; Abdullah, H. Z.

    2015-07-01

    Black tilapia (Oreochromis mossambicus) fish wastes (scales) were evaluated for its suitability as sources of gelatin. Scales were subjected to acid treatment for demineralization before it undergoes thermal extraction process. The raw scales were characterized via Scanning Electron Microscopy (SEM), which demarcated the cycloid pattern of the scales. SEM images also reveal the presence of collagen fiber in the fish scale. The black tilapia fish scales yields 11.88 % of gelatin, indicating the possibility of this fish species as sources of gelatin. Further characterizations were done on both raw scale and extracted gelatin through Fourier Transform Infrared Spectroscopy (FTIR) and proximate analysis. The scale gelatin shows high protein content (86.9 %) with low moisture (8.2 %) and ash (1.4 %). This further proves the effectiveness of the demineralization and extraction method used. The black tilapia fish scale is found to be a prospective source of gelatin with good chemical and functional properties.

  14. Extraction and characterization of gelatin biopolymer from black tilapia (Oreochromis mossambicus) scales

    Energy Technology Data Exchange (ETDEWEB)

    Sockalingam, K., E-mail: gd130106@siswa.uthm.edu.my; Abdullah, H. Z., E-mail: hasan@uthm.edu.my [Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor (Malaysia)

    2015-07-22

    Black tilapia (Oreochromis mossambicus) fish wastes (scales) were evaluated for its suitability as sources of gelatin. Scales were subjected to acid treatment for demineralization before it undergoes thermal extraction process. The raw scales were characterized via Scanning Electron Microscopy (SEM), which demarcated the cycloid pattern of the scales. SEM images also reveal the presence of collagen fiber in the fish scale. The black tilapia fish scales yields 11.88 % of gelatin, indicating the possibility of this fish species as sources of gelatin. Further characterizations were done on both raw scale and extracted gelatin through Fourier Transform Infrared Spectroscopy (FTIR) and proximate analysis. The scale gelatin shows high protein content (86.9 %) with low moisture (8.2 %) and ash (1.4 %). This further proves the effectiveness of the demineralization and extraction method used. The black tilapia fish scale is found to be a prospective source of gelatin with good chemical and functional properties.

  15. Extraction and characterization of gelatin biopolymer from black tilapia (Oreochromis mossambicus) scales

    International Nuclear Information System (INIS)

    Sockalingam, K.; Abdullah, H. Z.

    2015-01-01

    Black tilapia (Oreochromis mossambicus) fish wastes (scales) were evaluated for its suitability as sources of gelatin. Scales were subjected to acid treatment for demineralization before it undergoes thermal extraction process. The raw scales were characterized via Scanning Electron Microscopy (SEM), which demarcated the cycloid pattern of the scales. SEM images also reveal the presence of collagen fiber in the fish scale. The black tilapia fish scales yields 11.88 % of gelatin, indicating the possibility of this fish species as sources of gelatin. Further characterizations were done on both raw scale and extracted gelatin through Fourier Transform Infrared Spectroscopy (FTIR) and proximate analysis. The scale gelatin shows high protein content (86.9 %) with low moisture (8.2 %) and ash (1.4 %). This further proves the effectiveness of the demineralization and extraction method used. The black tilapia fish scale is found to be a prospective source of gelatin with good chemical and functional properties

  16. MAT FOR LEPTOSPIROSIS DIAGNOSIS

    Directory of Open Access Journals (Sweden)

    Esti Rahardianingtyas.

    2014-06-01

    Full Text Available Leptospirosis is a disease caused by bacterial infection leptospira interrogans.Leptospira bacteria is a spiral bacterium with solid strands with two flagella periplasmik.Septicaemic phase patient samples taken from the blood and cerebrospinal fluid, whereassamples taken at phase immune extracted from urine. The diagnosis of leptospirosis occurdirectly or indirectly. Diagnosis is done by directly isolate and identify the causative agents ofthe agent. Diagnosis is done indirectly by detecting specific antibodies from the patient's body.Gold Standard of the diagnosis of leptospirosis is MAT. Mat made by reacting antibodies toleptospira antigen. Positive results seen with clump formed.Key words: Leptospirosis, Leptospirosis Diagnostic, MAT (Microscopic Agglutination Test Leptospirosis merupakan penyakit yang disebabkan karena infeksi bakteri leptospirainterrogans. Bakteri leptospira merupakan bakteri spiral dengan untaian yang padat dengan duaflagella periplasmik. Sampel pasien pada fase septicaemic diambil dari darah dan cairanserebrospinal, sedangkan sampel yang diambil pada fase immune diambil dari urine. Diagnosisleptospirosis dilakukan secara langsung maupun tidak langsung. Diagnosis secara langsungdilakukan dengan cara mengisolasi agen penyebab dan mengidentifikasi agen tersebut. Diagnosissecara tidak langsung dilakukan dengan cara mendeteksi antibodi spesiflk dari dalam tubuhpasien. Gold Standart dari diagnosis leptospirosis adalah MAT. Mat dilakukan dengan caramereaksikan antibodi dengan antigen leptospira. Hasil positif dilihat dengan terbentuk gumpalanagglutinasiKata kunci: Leptospirosis, Leptospira, Leptospirosis Diagnosis.

  17. Hierarchically Structured Electrospun Fibers

    Science.gov (United States)

    2013-01-07

    in the natural lotus and silver ragwort leaves. Figure 4. Examples of electrospun bio-mimics of natural hierarchical structures. (A) Lotus leaf...B) pillared poly(methyl methacrylate) (PMMA) electrospun fiber mimic; (C) silver ragwort leaf; (D) electrospun fiber mimic made from nylon 6 and...domains containing the protein in the surrounding EVA fibers [115]. A wide variety of core-shell fibers have been generated, including PCL/ gelatin

  18. Diazotrophic microbial mats

    NARCIS (Netherlands)

    Severin, I.; Stal, L.J.; Seckbach, J.; Oren, A.

    2010-01-01

    Microbial mats have been the focus of scientific research for a few decades. These small-scale ecosystems are examples of versatile benthic communities of microorganisms, usually dominated by phototrophic bacteria (e.g., Krumbein et al., 1977; Jørgensen et al., 1983). They develop as vertically

  19. Investigation of VEGGIE Root Mat

    Science.gov (United States)

    Subbiah, Arun M.

    2013-01-01

    VEGGIE is a plant growth facility that utilizes the phenomenon of capillary action as its primary watering system. A cloth made of Meta Aramid fiber, known as Nomex is used to wick water up from a reservoir to the bottom of the plants roots. This root mat system is intended to be low maintenance with no moving parts and requires minimal crew interface time. Unfortunately, the water wicking rates are inconsistent throughout the plant life cycle, thus causing plants to die. Over-wicking of water occurs toward the beginning of the cycle, while under-wicking occurs toward the middle. This inconsistency of wicking has become a major issue, drastically inhibiting plant growth. The primary objective is to determine the root cause of the inconsistent wicking through experimental testing. Suspect causes for the capillary water column to break include: a vacuum effect due to a negative pressure gradient in the water reservoir, contamination of material due to minerals in water and back wash from plant fertilizer, induced air bubbles while using syringe refill method, and material limitations of Nomex's ability to absorb and retain water. Experimental testing will be conducted to systematically determine the cause of under and over-wicking. Pressure gages will be used to determine pressure drop during the course of the plant life cycle and during the water refill process. A debubbler device will be connected to a root mat in order to equalize pressure inside the reservoir. Moisture and evaporation tests will simultaneously be implemented to observe moisture content and wicking rates over the course of a plant cycle. Water retention tests will be performed using strips of Nomex to determine materials wicking rates, porosity, and absorptivity. Through these experimental tests, we will have a better understanding of material properties of Nomex, as well as determine the root cause of water column breakage. With consistent test results, a forward plan can be achieved to resolve

  20. Fiber

    Science.gov (United States)

    ... meals instead of white rice. Add beans (kidney, black, navy, and pinto) to rice dishes for even more fiber. Spice up salads with berries and almonds, chickpeas, cooked artichokes, and beans (kidney, black, navy, or pinto). Use whole-grain (corn or ...

  1. Fabrication of nanofiber mats from electrospinning of functionalized polymers

    Science.gov (United States)

    Oktay, Burcu; Kayaman-Apohan, Nilhan; Erdem-Kuruca, Serap

    2014-08-01

    Electrospinning technique enabled us to prepare nanofibers from synthetic and natural polymers. In this study, it was aimed to fabricate electrospun poly(vinyl alcohol) (PVA) based nanofibers by reactive electrospinning process. To improve endurance of fiber toward to many solvents, PVA was functionalized with photo-crosslinkable groups before spinning. Afterward PVA was crosslinked by UV radiation during electrospinning process. The nanofiber mats were characterized by scanning electron microscopy (SEM). The results showed that homogenous, uniform and crosslinked PVA nanofibers in diameters of about 200 nm were obtained. Thermal stability of the nanofiber mat was investigated with thermal gravimetric analysis (TGA). Also the potential use of this nanofiber mats for tissue engineering was examined. Osteosarcoma (Saos) cells were cultured on the nanofiber mats.

  2. Fabrication of nanofiber mats from electrospinning of functionalized polymers

    International Nuclear Information System (INIS)

    Oktay, Burcu; Kayaman-Apohan, Nilhan; Erdem-Kuruca, Serap

    2014-01-01

    Electrospinning technique enabled us to prepare nanofibers from synthetic and natural polymers. In this study, it was aimed to fabricate electrospun poly(vinyl alcohol) (PVA) based nanofibers by reactive electrospinning process. To improve endurance of fiber toward to many solvents, PVA was functionalized with photo-crosslinkable groups before spinning. Afterward PVA was crosslinked by UV radiation during electrospinning process. The nanofiber mats were characterized by scanning electron microscopy (SEM). The results showed that homogenous, uniform and crosslinked PVA nanofibers in diameters of about 200 nm were obtained. Thermal stability of the nanofiber mat was investigated with thermal gravimetric analysis (TGA). Also the potential use of this nanofiber mats for tissue engineering was examined. Osteosarcoma (Saos) cells were cultured on the nanofiber mats

  3. In vitro evaluation of crosslinked electrospun fish gelatin scaffolds

    International Nuclear Information System (INIS)

    Gomes, S.R.; Rodrigues, G.; Martins, G.G.; Henriques, C.M.R.; Silva, J.C.

    2013-01-01

    Gelatin from cold water fish skin was electrospun, crosslinked and investigated as a substrate for the adhesion and proliferation of cells. Gelatin was first dissolved in either water or concentrated acetic acid and both solutions were successfully electrospun. Cross-linking was achieved via three different routes: glutaraldehyde vapor, genipin and dehydrothermal treatment. Solution's properties (surface tension, electrical conductivity and viscosity) and scaffold's properties (chemical bonds, weight loss and fiber diameters) were measured. Cellular viability was analyzed culturing 3T3 fibroblasts plated on the scaffolds and grown up to 7 days. The cells were fixed and observed with SEM or stained for DNA and F-actin and observed with confocal microscopy. In all scaffolds, the cells attached and spread with varying degrees. The evaluation of cell viability showed proliferation of cells until confluence in scaffolds crosslinked by glutaraldehyde and genipin; however the rate of growth in genipin crosslinked scaffolds was slow, recovering only by day five. The results using the dehydrothermal treatment were the less satisfactory. Our results show that glutaraldehyde treated fish gelatin is the most suitable substrate, of the three studied, for fibroblast adhesion and proliferation. - Highlights: ► Electrospinning of fish gelatin dissolved in both water or concentrated acetic acid ► Glutaraldehyde, genipin and dehydrothermal treatment effectively crosslink the fish gelatin fibers ► Fibroblasts effectively adhere to and propagate on all scaffolds ► Cell population is highest for glutaraldehyde crosslinked scaffolds ► Cells exhibit more filopodia and stress fibers on glutaraldehyde crosslinked scaffolds

  4. In vitro evaluation of crosslinked electrospun fish gelatin scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, S.R. [Centro de Física e Investigação Tecnológica / Departamento de Física, Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Rodrigues, G.; Martins, G.G. [Centro de Biologia Ambiental / Departamento de Biologia Animal, Faculdade de Ciências da Universidade de Lisboa, FCUL, 1749-016 Campo Grande, Lisboa (Portugal); Henriques, C.M.R. [Centro de Física e Investigação Tecnológica / Departamento de Física, Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Silva, J.C., E-mail: jcs@fct.unl.pt [Centro de Física e Investigação Tecnológica / Departamento de Física, Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal)

    2013-04-01

    Gelatin from cold water fish skin was electrospun, crosslinked and investigated as a substrate for the adhesion and proliferation of cells. Gelatin was first dissolved in either water or concentrated acetic acid and both solutions were successfully electrospun. Cross-linking was achieved via three different routes: glutaraldehyde vapor, genipin and dehydrothermal treatment. Solution's properties (surface tension, electrical conductivity and viscosity) and scaffold's properties (chemical bonds, weight loss and fiber diameters) were measured. Cellular viability was analyzed culturing 3T3 fibroblasts plated on the scaffolds and grown up to 7 days. The cells were fixed and observed with SEM or stained for DNA and F-actin and observed with confocal microscopy. In all scaffolds, the cells attached and spread with varying degrees. The evaluation of cell viability showed proliferation of cells until confluence in scaffolds crosslinked by glutaraldehyde and genipin; however the rate of growth in genipin crosslinked scaffolds was slow, recovering only by day five. The results using the dehydrothermal treatment were the less satisfactory. Our results show that glutaraldehyde treated fish gelatin is the most suitable substrate, of the three studied, for fibroblast adhesion and proliferation. - Highlights: ► Electrospinning of fish gelatin dissolved in both water or concentrated acetic acid ► Glutaraldehyde, genipin and dehydrothermal treatment effectively crosslink the fish gelatin fibers ► Fibroblasts effectively adhere to and propagate on all scaffolds ► Cell population is highest for glutaraldehyde crosslinked scaffolds ► Cells exhibit more filopodia and stress fibers on glutaraldehyde crosslinked scaffolds.

  5. Anisotropic silk fibroin/gelatin scaffolds from unidirectional freezing

    Energy Technology Data Exchange (ETDEWEB)

    Asuncion, Maria Christine Tankeh, E-mail: christine.asuncion@u.nus.edu [National University of Singapore, Department of Biomedical Engineering (Singapore); Goh, James Cho-Hong [National University of Singapore, Department of Biomedical Engineering (Singapore); National University of Singapore, Department of Orthopedic Surgery (Singapore); Toh, Siew-Lok [National University of Singapore, Department of Biomedical Engineering (Singapore); National University of Singapore, Department of Mechanical Engineering (Singapore)

    2016-10-01

    Recent studies have underlined the importance of matching scaffold properties to the biological milieu. Tissue, and thus scaffold, anisotropy is one such property that is important yet sometimes overlooked. Methods that have been used to achieve anisotropic scaffolds present challenges such as complicated fabrication steps, harsh processing conditions and toxic chemicals involved. In this study, unidirectional freezing was employed to fabricate anisotropic silk fibroin/gelatin scaffolds in a simple and mild manner. Morphological, mechanical, chemical and cellular compatibility properties were investigated, as well as the effect of the addition of gelatin to certain properties of the scaffold. It was shown that scaffold properties were suitable for cell proliferation and that mesenchymal stem cells were able to align themselves along the directed fibers. The fabricated scaffolds present a platform that can be used for anisotropic tissue engineering applications such as cardiac patches. - Highlights: • Silk/gelatin scaffolds with unidirectional alignment were fabricated using a simple and scalable process • Presence of gelatin in silk resulted to lesser shrinkage, better water retention and improved cell proliferation. • Mesenchymal stem cells were shown to align themselves according to the fiber alignment.

  6. Degradabilidade da matéria seca e da fração fibrosa da cana de açúcar tratada com óxido de cálcio Dry matter and fiber fraction degradability of sugar cane treated with calcium oxide

    Directory of Open Access Journals (Sweden)

    Claithiane Oliveira Soares

    2011-06-01

    Full Text Available Objetivou-se avaliar os parâmetros de degradação ruminal da matéria seca, da fibra em detergente neutro e fibra em detergente ácido da cana de açúcar tratada com óxido de cálcio nas doses zero, 1; 2 e 3% (com base na matéria natural. Foram incubados no rúmen de três novilhos por períodos de zero; seis; 12; 24; 48; 72; 96; 120 e 144 horas, sacos de náilon contendo amostras de 2,5g da cana de açúcar tratada com óxido de cálcio. Verificou-se degradabilidade potencial de 80,7% na matéria seca para cana de açúcar tratada com 3% de óxido de cálcio. Os resultados da fração degradável para fibra em detergente neutro e para fibra em detergente ácido no tratamento com 3% de óxido de cálcio foram de 59,7 e 59,9%, respectivamente, enquanto, a cana sem aditivo, apresentou valores de degradação de 44,5% para fibra em detergente neutro e de 39,5% para fibra em detergente ácido. Houve incremento nos parâmetros da degradabilidade da matéria seca da fração “a” de 37,5 vs 46,8% da cana sem aditivo para a cana de açúcar com a dose de 3% de óxido de cálcio. Para a degradabilidade da fibra em detergente ácido foi observado efeito semelhante ao da degradabilidade da fibra em detergente neutro, com valores da fração potencialmente degradável “b” que corresponderam a 64,2 e 68,7%, respectivamente, na dose de 3% de óxido de cálcio.The objective of this work was to evaluate the parameters of ruminal degradation of dry matter, neutral detergent fiber and acid detergent fiber of the sugar cane treated with calcium oxide in the doses of 0; 1; 2 and 3 % (with basis of the natural matter. The samples were incubated in the rumen of three steers for 0; 6; 12; 24; 48; 72; 96; 120 and 144 hours, on nylon bags containing 2.5g of sugar cane treated with calcium oxide. There was 80.7% of potential degradability in dry matter for sugar cane treated with 3% calcium oxide. The results for degradable fraction for neutral detergent

  7. Electrospun polyvinylpyrrolidone (PVP)/green tea extract composite nanofiber mats and their antioxidant activities

    Science.gov (United States)

    Pusporini, Pusporini; Edikresnha, Dhewa; Sriyanti, Ida; Suciati, Tri; Miftahul Munir, Muhammad; Khairurrijal, Khairurrijal

    2018-05-01

    Electrospinning was employed to make PVP (polyvinylpyrrolidone)/GTE (green tea extract) composite nanofiber mats. The electrospun PVP nanofiber mat as well as the PVP/GTE nanofiber mats were uniform. The average fiber diameter of PVP/GTE composite nanofiber mat decreased with increasing the GTE weight fraction (or decreasing the PVP weight fraction) in the PVP/GTE solution because the PVP/GTE solution concentration decreased. Then, the broad FTIR peak representing the stretching vibrations of O–H in hydroxyl groups of phenols and the stretching of N–H in amine groups of the GTE paste shifted to higher wavenumbers in the PVP/GTE composite nanofiber mats. These peak shifts implied that PVP and catechins of GTE in the PVP/GTE composite nanofiber mats had intermolecular interactions via hydrogen bonds between carbonyl groups of PVP and hydroxyl groups of catechins in GTE. Lastly, the antioxidant activity of the PVP/GTE composite nanofiber mat increased with reducing the average fiber diameter because the amount of catechins in the composite nanofiber mat increased with the increase of surface area due to the reduction of the average fiber diameter.

  8. Molecular ecology of microbial mats

    NARCIS (Netherlands)

    Bolhuis, H.; Cretoiu, M.S.; Stal, L.J.

    2014-01-01

    Phototrophic microbial mats are ideal model systems for ecological and evolutionary analysis of highly diverse microbial communities. Microbial mats are small-scale, nearly closed, and self-sustaining benthic ecosystems that comprise the major element cycles, trophic levels, and food webs. The steep

  9. Gelatin/chitosan biofilm: preparation and characterization

    International Nuclear Information System (INIS)

    Trindade, Luciane da C.; Nunes, Raquel A.; Diniz, Nadie K.S.; Braga, Carla R.C.; Silva, Suedina M. de Lima

    2011-01-01

    In this study, gelatin, chitosan and gelatin/chitosan bio films using the ratio of gelatin/chitosan (50/50) were prepared by casting method. The bio films prepared were characterized by X-ray diffraction, scanning electron microscopy and dissolution ratio. According to the results, the incorporation of chitosan into gelatin indicate the decrease of crystallinity of chitosan, a compact structure without large pores and that the dissolution of gelatin/chitosan film is little influenced by hot water than gelatin films. (author)

  10. Soft gelatin capsules (softgels).

    Science.gov (United States)

    Gullapalli, Rampurna Prasad

    2010-10-01

    It is estimated that more than 40% of new chemical entities (NCEs) coming out of the current drug discovery process have poor biopharmaceutical properties, such as low aqueous solubility and/or permeability. These suboptimal properties pose significant challenges for the oral absorption of the compounds and for the development of orally bioavailable dosage forms. Development of soft gelatin capsule (softgel) dosage form is of growing interest for the oral delivery of poorly water soluble compounds (BCS class II or class IV). The softgel dosage form offers several advantages over other oral dosage forms, such as delivering a liquid matrix designed to solubilize and improve the oral bioavailability of a poorly soluble compound as a unit dose solid dosage form, delivering low and ultra-low doses of a compound, delivering a low melting compound, and minimizing potential generation of dust during manufacturing and thereby improving the safety of production personnel. However, due to the very dynamic nature of the softgel dosage form, its development and stability during its shelf-life are fraught with several challenges. The goal of the current review is to provide an in-depth discussion on the softgel dosage form to formulation scientists who are considering developing softgels for therapeutic compounds.

  11. Development and characterization of coaxially electrospun gelatin coated poly (3-hydroxybutyric acid) thin films as potential scaffolds for skin regeneration

    International Nuclear Information System (INIS)

    Nagiah, Naveen; Madhavi, Lakshmi; Anitha, R.; Anandan, C.; Srinivasan, Natarajan Tirupattur; Sivagnanam, Uma Tirichurapalli

    2013-01-01

    The morphology of fibers synthesized through electrospinning has been found to mimic extracellular matrix. Coaxially electrospun fibers of gelatin (sheath) coated poly (3-hydroxybutyric acid) (PHB) (core) was developed using 2,2,2 trifluoroethanol(TFE) and 1,1,1,3,3,3 hexafluoro-2-propanol(HFIP) as solvents respectively. The coaxial structure and coating of gelatin with PHB fibers was confirmed through transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Thermal stability of the coaxially electrospun fibers was analyzed using thermogravimetric analysis(TGA), differential scanning calorimetry(DSC) and differential thermogravimetric analysis(DTA). Complete evaporation of solvent and gelatin grafting over PHB fibers was confirmed through attenuated total reflection-Fourier transformed infrared spectroscopy (ATR-FTIR). The coaxially electrospun fibers exhibited competent tensile properties for skin regeneration with high surface area and porosity. In vitro degradation studies proved the stability of fibers and its potential applications in tissue engineering. The fibers supported the growth of human dermal fibroblasts and keratinocytes with normal morphology indicating its potential as a scaffold for skin regeneration. - Highlights: • Coaxial electrospinning was employed to develop core-shell fibers of PHB and gelatin. • The scaffold has competent physicochemical properties. • Developed scaffold will have high impact as a dermal substitute in skin regeneration

  12. Development and characterization of coaxially electrospun gelatin coated poly (3-hydroxybutyric acid) thin films as potential scaffolds for skin regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Nagiah, Naveen [Bioproducts Lab, Central Leather Research Institute, Adyar, Chennai (India); Madhavi, Lakshmi; Anitha, R. [CavinKare Research Centre, Ekkattuthangal, Chennai (India); Anandan, C. [National Aerospace Laboratory, Banglore (India); Srinivasan, Natarajan Tirupattur, E-mail: naveen.nagiah@gmail.com [Conducting Polymers Lab, Department of Physics, Indian Institute of Technology Madras, Chennai (India); Sivagnanam, Uma Tirichurapalli, E-mail: suma67@gmail.com [Bioproducts Lab, Central Leather Research Institute, Adyar, Chennai (India)

    2013-10-01

    The morphology of fibers synthesized through electrospinning has been found to mimic extracellular matrix. Coaxially electrospun fibers of gelatin (sheath) coated poly (3-hydroxybutyric acid) (PHB) (core) was developed using 2,2,2 trifluoroethanol(TFE) and 1,1,1,3,3,3 hexafluoro-2-propanol(HFIP) as solvents respectively. The coaxial structure and coating of gelatin with PHB fibers was confirmed through transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Thermal stability of the coaxially electrospun fibers was analyzed using thermogravimetric analysis(TGA), differential scanning calorimetry(DSC) and differential thermogravimetric analysis(DTA). Complete evaporation of solvent and gelatin grafting over PHB fibers was confirmed through attenuated total reflection-Fourier transformed infrared spectroscopy (ATR-FTIR). The coaxially electrospun fibers exhibited competent tensile properties for skin regeneration with high surface area and porosity. In vitro degradation studies proved the stability of fibers and its potential applications in tissue engineering. The fibers supported the growth of human dermal fibroblasts and keratinocytes with normal morphology indicating its potential as a scaffold for skin regeneration. - Highlights: • Coaxial electrospinning was employed to develop core-shell fibers of PHB and gelatin. • The scaffold has competent physicochemical properties. • Developed scaffold will have high impact as a dermal substitute in skin regeneration.

  13. Surface modification of nanofibrous polycaprolactone/gelatin composite scaffold by collagen type I grafting for skin tissue engineering

    International Nuclear Information System (INIS)

    Gautam, Sneh; Chou, Chia-Fu; Dinda, Amit K.; Potdar, Pravin D.; Mishra, Narayan C.

    2014-01-01

    In the present study, a tri-polymer polycaprolactone (PCL)/gelatin/collagen type I composite nanofibrous scaffold has been fabricated by electrospinning for skin tissue engineering and wound healing applications. Firstly, PCL/gelatin nanofibrous scaffold was fabricated by electrospinning using a low cost solvent mixture [chloroform/methanol for PCL and acetic acid (80% v/v) for gelatin], and then the nanofibrous PCL/gelatin scaffold was modified by collagen type I (0.2–1.5 wt.%) grafting. Morphology of the collagen type I-modified PCL/gelatin composite scaffold that was analyzed by field emission scanning electron microscopy (FE-SEM), showed that the fiber diameter was increased and pore size was decreased by increasing the concentration of collagen type I. Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric (TG) analysis indicated the surface modification of PCL/gelatin scaffold by collagen type I immobilization on the surface of the scaffold. MTT assay demonstrated the viability and high proliferation rate of L929 mouse fibroblast cells on the collagen type I-modified composite scaffold. FE-SEM analysis of cell-scaffold construct illustrated the cell adhesion of L929 mouse fibroblasts on the surface of scaffold. Characteristic cell morphology of L929 was also observed on the nanofiber mesh of the collagen type I-modified scaffold. Above results suggest that the collagen type I-modified PCL/gelatin scaffold was successful in maintaining characteristic shape of fibroblasts, besides good cell proliferation. Therefore, the fibroblast seeded PCL/gelatin/collagen type I composite nanofibrous scaffold might be a potential candidate for wound healing and skin tissue engineering applications. - Highlights: • PCL/gelatin/collagen type I scaffold was fabricated for skin tissue engineering. • PCL/gelatin/collagen type I scaffold showed higher fibroblast growth than PCL/gelatin one. • PCL/gelatin/collagen type I might be one of the ideal scaffold for

  14. Electrospun gelatin/sodium bicarbonate and poly(lactide-co-ε-caprolactone)/sodium bicarbonate nanofibers as drug delivery systems.

    Science.gov (United States)

    Sang, Qingqing; Williams, Gareth R; Wu, Huanling; Liu, Kailin; Li, Heyu; Zhu, Li-Min

    2017-12-01

    In this work, we report electrospun nanofibers made of model hydrophobic (poly(lactide-co-ε-caprolactone); PLCL) and hydrophilic (gelatin) polymers. We explored the effect on drug release of the incorporation of sodium bicarbonate (SB) into these fibers, using the potent antibacterial agent ciprofloxacin as a model drug. The fibers prepared are smooth and have relatively uniform diameters lying between ca. 600 and 850nm. The presence of ciprofloxacin in the fibers was confirmed using IR spectroscopy. X-ray diffraction showed the drug to be incorporated into the fibers in the amorphous form. In vitro drug release studies revealed that, as expected, more rapid drug release was seen with gelatin fibers than those made of PLCL, and a greater final release percentage was obtained. The inclusion of SB in the gelatin fibers imparts them with pH sensitivity: gelatin/SB fibers showed faster release at pH5 than pH7.4, while fibers without SB gave the same release profiles at both pHs. The PLCL fibers have no pH sensitivity, even when SB was included, as a result of their hydrophobic structure precluding the ingress of solvent. In vitro cell culture studies showed that all the fibers are able to promote cell proliferation. The ciprofloxacin loaded fibers are effective in inhibiting Escherichia coli and Staphylococcus aureus growth in antibacterial tests. Thus, the gelatin-based fibers can be used as pH-responsive drug delivery systems, with potential applications for instance in the treatment of tumor resection sites. Should these become infected, the pH would drop, resulting in ciprofloxacin being released and the infection halted. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  15. Transplantation of artificial gelatin-co-bletillastriata gelatin/Salvia ...

    African Journals Online (AJOL)

    Tropical Journal of Pharmaceutical Research April 2016; 15 (4): 735-741 ... Methods: The composite artificial corium was constructed by culturing fibroblast cells in gelatin-co- ... Conclusion: The composite artificial corium has some clinical prospects for use in the treatment of ... burns, and treatment of large areas of skin.

  16. MICROBIAL MATS - A JOINT VENTURE

    NARCIS (Netherlands)

    VANGEMERDEN, H

    Microbial mats characteristically are dominated by a few functional groups of microbes: cyanobacteria, colorless sulfur bacteria, purple sulfur bacteria, and sulfate-reducing bacteria. Their combined metabolic activities result in steep environmental microgradients, particularly of oxygen and

  17. Evaluation of polyacrylonitrile electrospun nano-fibrous mats as leukocyte removal filter media.

    Science.gov (United States)

    Pourbaghi, Raha; Zarrebini, Mohammad; Semnani, Dariush; Pourazar, Abbasali; Akbari, Nahid; Shamsfar, Reihaneh

    2017-09-13

    Removal of leukocytes from blood products is the most effective means for elimination of undesirable side effects and prevention of possible reactions in recipients. Micro-fibrous mats are currently used for removal of leukocytes from blood. In this study, samples of electrospun nano-fibrous mats were produced. The performance of the produced electrospun nano-fibrous mats as means of leukocytes removal from fresh whole blood was both evaluated and compared with that of commercially available micro-fibrous mats. In order to produce the samples, polyacrylonitrile (PAN) nano-fibrous mats were made under different electrospinning conditions. Mean fiber diameter, pore characterization and surface roughness of the PAN nano-fibrous mats were determined using image processing technique. In order to evaluate the surface tension of the fabricated mats, water contact angle was measured. The leukocyte removal performance, erythrocytes recovery percent and hemolysis rate of the nano-fibrous mats were compared. The effectiveness of nano-fibrous mats in removing leukocyte was established using both scanning electron microscope and optical microscope. Results showed that for given weight, the fabricated nano-fibrous mats were not only more efficient but also more cost-effective than their commercial counterparts. Results confirmed that changes in mean fiber diameter, the number of layer and weight of each layer in the absence of any chemical reaction or physical surface modification, the fabricated nano-fibrous mats were able to remove 5-log of leukocytes. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2017. © 2017 Wiley Periodicals, Inc.

  18. Protein and Bacterial Antifouling Behavior of Melt-Coextruded Nanofiber Mats.

    Science.gov (United States)

    Kim, Si-Eun; Zhang, Cong; Advincula, Abigail A; Baer, Eric; Pokorski, Jonathan K

    2016-04-13

    Antifouling surfaces are important for biomedical devices to prevent secondary infections and mitigate the effects of the foreign body response. Herein, we describe melt-coextruded poly(ε-caprolactone) (PCL) nanofiber mats grafted with antifouling polymers. Nonwoven PCL fiber mats are produced using a multilayered melt coextrusion process followed by high-pressure hydroentanglement to yield porous patches. The resulting fiber mats show submicrometer cross-sectional fiber dimensions and yield pore sizes that were nearly uniform, with a mean pore size of 1.6 ± 0.9 μm. Several antifouling polymers, including hydrophilic, zwitterionic, and amphipathic molecules, are grafted to the surface of the mats using a two-step procedure that includes photochemistry followed by the copper-catalyzed azide-alkyne cycloaddition reaction. Fiber mats are evaluated using separate adsorption tests for serum proteins and E. coli. The results indicate that poly(oligo(ethylene glycol) methyl ether methacrylate)-co-(trifluoroethyl methacrylate) (poly(OEGMEMA-co-TFEMA)) grafted mats exhibit approximately 85% less protein adhesion and 97% less E. coli adsorption when compared to unmodified PCL fibermats. In dynamic antifouling testing, the amphiphilic fluorous polymer surface shows the highest flux and highest rejection value of foulants. The work presented within has implications on the high-throughput production of antifouling microporous patches for medical applications.

  19. Projectile penetration into ballistic gelatin.

    Science.gov (United States)

    Swain, M V; Kieser, D C; Shah, S; Kieser, J A

    2014-01-01

    Ballistic gelatin is frequently used as a model for soft biological tissues that experience projectile impact. In this paper we investigate the response of a number of gelatin materials to the penetration of spherical steel projectiles (7 to 11mm diameter) with a range of lower impacting velocities (projectile velocity are found to be linear for all systems above a certain threshold velocity required for initiating penetration. The data for a specific material impacted with different diameter spheres were able to be condensed to a single curve when the penetration depth was normalised by the projectile diameter. When the results are compared with a number of predictive relationships available in the literature, it is found that over the range of projectiles and compositions used, the results fit a simple relationship that takes into account the projectile diameter, the threshold velocity for penetration into the gelatin and a value of the shear modulus of the gelatin estimated from the threshold velocity for penetration. The normalised depth is found to fit the elastic Froude number when this is modified to allow for a threshold impact velocity. The normalised penetration data are found to best fit this modified elastic Froude number with a slope of 1/2 instead of 1/3 as suggested by Akers and Belmonte (2006). Possible explanations for this difference are discussed. © 2013 Published by Elsevier Ltd.

  20. Fabrication and characterization of PCL/gelatin composite nanofibrous scaffold for tissue engineering applications by electrospinning method

    International Nuclear Information System (INIS)

    Gautam, Sneh; Dinda, Amit Kumar; Mishra, Narayan Chandra

    2013-01-01

    In the present study, composite nanofibrous tissue engineering-scaffold consisting of polycaprolactone and gelatin, was fabricated by electrospinning method, using a new cost-effective solvent mixture: chloroform/methanol for polycaprolactone (PCL) and acetic acid for gelatin. The morphology of the nanofibrous scaffold was investigated by using field emission scanning electron microscopy (FE-SEM) which clearly indicates that the morphology of nanofibers was influenced by the weight ratio of PCL to gelatin in the solution. Uniform fibers were produced only when the weight ratio of PCL/gelatin is sufficiently high (10:1). The scaffold was further characterized by Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric (TG) analysis, and X-ray diffraction (XRD). FT-IR and TG analysis indicated some interactions between PCL and gelatin molecules within the scaffold, while XRD results demonstrated crystalline nature of PCL/gelatin composite scaffold. Cytotoxicity effect of scaffold on L929 mouse fibroblast cells was evaluated by MTT assay and cell proliferation on the scaffold was confirmed by DNA quantification. Positive results of MTT assay and DNA quantification L929 mouse fibroblast cells indicated that the scaffold made from the combination of natural polymer (gelatin) and synthetic polymer (PCL) may serve as a good candidate for tissue engineering applications. - Highlights: ► PCL/Gelatin scaffold was successfully fabricated by electrospinning method. ► PCL in CHCl 3 /CH 3 OH and gelatin in acetic acid: a novel polymer-solvent system. ► The morphology of nanofibers was influenced by the weight ratio of PCL/gelatin. ► Chemical interactions between PCL and gelatin molecules enhanced cell growth. ► Cell culture studies indicate the suitability of scaffold for tissue regeneration

  1. Enhanced Critical Size Defect Repair in Rabbit Mandible by Electrospun Gelatin/β-TCP Composite Nanofibrous Membranes

    Directory of Open Access Journals (Sweden)

    Mingming Xu

    2015-01-01

    Full Text Available The design and fabrication of biodegradable barrier membranes with satisfactory structure and composition remain a considerable challenge for periodontal tissue regeneration. We have developed a biomimetic nanofibrous membrane made from a composite of gelatin and β-tricalcium phosphate (β-TCP. We previously confirmed the in vitro biological performance of the membrane material, but the efficacy of the membranes in promoting bone repair in situ has not yet been examined. Gelatin/β-TCP composite nanofibers were fabricated by incorporation of 20 wt.% β-TCP nanoparticles into electrospun gelatin nanofibers. Electron microscopy showed that the composite membranes presented a nonwoven structure with an interconnected porous network and had a rough surface due to the β-TCP nanoparticles, which were distributed widely and uniformly throughout the gelatin-fiber matrix. The repair efficacy of rabbit mandible defects implanted with bone substitute (Bio-Oss and covered with the gelatin/β-TCP composite nanofibrous membrane was evaluated in comparison with pure gelatin nanofibrous membrane. Gross observation, histological examination, and immunohistochemical analysis showed that new bone formation and defect closure were significantly enhanced by the composite membranes compared to the pure gelatin ones. From these results, we conclude that nanofibrous gelatin/β-TCP composite membranes could serve as effective barrier membranes for guided tissue regeneration.

  2. Biofabrication of implants for articular joint repair : Cartilage regeneration in reinforced gelatin-based hydrogels

    NARCIS (Netherlands)

    Visser, J.

    2015-01-01

    Implants were biofabricated for the repair of chondral and osteochondral articular joint defects. The implants were based on gelatin methacrylamide (GelMA) hydrogels combined with printed fibers from polycaprolactone (PCL) for mechanical reinforcement. In Part I of the thesis, biological

  3. Biomimetic fiber assembled gradient hydrogel to engineer glycosaminoglycan enriched and mineralized cartilage: An in vitro study.

    Science.gov (United States)

    Mohan, Neethu; Wilson, Jijo; Joseph, Dexy; Vaikkath, Dhanesh; Nair, Prabha D

    2015-12-01

    The study investigated the potential of electrospun fiber assembled hydrogel, with physical gradients of chondroitin sulfate (CS) and sol-gel-derived bioactive glass (BG), to engineer hyaline and mineralized cartilage in a single 3D system. Electrospun poly(caprolactone) (PCL) fibers incorporated with 0.1% w/w of CS (CSL) and 0.5% w/w of CS (CSH), 2.4% w/w of BG (BGL) and 12.5% w/w of BG (BGH) were fabricated. The CS showed a sustained release up to 3 days from CSL and 14 days from CSH fibers. Chondrocytes secreted hyaline like matrix with higher sulfated glycosaminoglycans (sGAG), collagen type II and aggrecan on CSL and CSH fibers. Mineralization was observed on BGL and BGH fibers when incubated in simulated body fluid for 14 days. Chondrocytes cultured on these fibers secreted a mineralized matrix that consisted of sGAG, hypertrophic proteins, collagen type X, and osteocalcin. The CS and BG incorporated PCL fiber mats were assembled in an agarose-gelatin hydrogel to generate a 3D hybrid scaffold. The signals in the fibers diffused and generated continuous opposing gradients of CS (chondrogenic signal) and BG (mineralization) in the hydrogel. The chondrocytes were encapsulated in hybrid scaffolds; live dead assay at 48 h showed viable cells. Cells maintained their phenotype and secreted specific extracellular matrix (ECM) in response to signals within the hydrogel. Continuous opposing gradients of sGAG enriched and mineralized ECM were observed surrounding each cell clusters on gradient hydrogel after 14 days of culture in response to the physical gradients of raw materials CS and BG. A construct with gradient mineralization might accelerate integration to subchondral bone during in vivo regeneration. © 2015 Wiley Periodicals, Inc.

  4. Evaluation of proanthocyanidin-crosslinked electrospun gelatin nanofibers for drug delivering system

    International Nuclear Information System (INIS)

    Huang, Chiung-Hua; Chi, Chin-Ying; Chen, Yueh-Sheng; Chen, Kuo-Yu; Chen, Pei-Lain; Yao, Chun-Hsu

    2012-01-01

    Electrospun nanofibers are excellent candidates for various biomedical applications. We successfully fabricated proanthocyanidin‐crosslinked gelatin electrospun nanofibers. Proanthocyanidin, a low cytotoxic collagen crosslinking reagent, increased the gelatin crosslinking percentage in the nanofibers from 53% to 64%. The addition of proanthocyanidin kept the nanofibers from swelling, and, thus, made the fibers more stable in the aqueous state. The compatibility and the release behavior of the drug in the nanofibers were examined using magnesium ascorbyl phosphate as the model drug. Proanthocyanidin also promoted drug loading and kept the drug release rate constant. These properties make the proanthocyanidin‐crosslinked gelatin nanofibers an excellent material for drug delivery. In the cell culture study, L929 fibroblast cells had a significantly higher proliferation rate when cultured with the gelatin/proanthocyanidin blended nanofibers. This characteristic showed that proanthocyanidin‐crosslinked gelatin electrospun nanofibers could potentially be employed as a wound healing material by increasing cell spreading and proliferation. - Highlights: ► Proanthocyanidin‐crosslinked gelatin nanofibers (GEL/PA) is synthesized. ► Proanthocyanidin promoted drug loading and kept the drug release rate constant. ► The GEL/PA nanofibers accelerate fibroblast cell proliferation. ► The GEL/PA nanofibers increase the drug loading efficiency.

  5. Extraction of high value added gelatin biopolymer from black tilapia (Oreochromis mossambicus) head bones

    Science.gov (United States)

    Sockalingam, K.; Abdullah, H. Z.

    2015-07-01

    Black tilapia (Oreochromis mossambicus) fish head bones were evaluated for its possibilities in extracting gelatin. Head bones were subjected to pre-treatment with 3% of hydrochloric acid (HCl) for demineralization before undergoes thermal extraction process. The raw head bones were characterized via Scanning Electron Microscopy (SEM) in order to investigate the external and internal surface morphology. SEM images also reveal the presence of collagen fiber with 1 µm diameter in the head bone. The black tilapia fish head bones yields 5.75 % of gelatin in wet weight basis, indicating the possibility of this fish species as sources of gelatin. Further characterizations were done on both raw head bones and extracted gelatin through Fourier Transform Infrared Spectroscopy (FTIR) and proximate analysis. The head bones gelatin shows high protein (10.55%) and ash (3.11 %) content with low moisture. This further proves the effectiveness of demineralization and extraction method used. The black tilapia fish head bones are found to be a prospective source of gelatin with good chemical and functional properties.

  6. Extraction of high value added gelatin biopolymer from black tilapia (Oreochromis mossambicus) head bones

    International Nuclear Information System (INIS)

    Sockalingam, K.; Abdullah, H. Z.

    2015-01-01

    Black tilapia (Oreochromis mossambicus) fish head bones were evaluated for its possibilities in extracting gelatin. Head bones were subjected to pre-treatment with 3% of hydrochloric acid (HCl) for demineralization before undergoes thermal extraction process. The raw head bones were characterized via Scanning Electron Microscopy (SEM) in order to investigate the external and internal surface morphology. SEM images also reveal the presence of collagen fiber with 1 µm diameter in the head bone. The black tilapia fish head bones yields 5.75 % of gelatin in wet weight basis, indicating the possibility of this fish species as sources of gelatin. Further characterizations were done on both raw head bones and extracted gelatin through Fourier Transform Infrared Spectroscopy (FTIR) and proximate analysis. The head bones gelatin shows high protein (10.55%) and ash (3.11 %) content with low moisture. This further proves the effectiveness of demineralization and extraction method used. The black tilapia fish head bones are found to be a prospective source of gelatin with good chemical and functional properties

  7. Extraction of high value added gelatin biopolymer from black tilapia (Oreochromis mossambicus) head bones

    Energy Technology Data Exchange (ETDEWEB)

    Sockalingam, K., E-mail: gd130106@siswa.uthm.edu.my; Abdullah, H. Z., E-mail: hasan@uthm.edu.my [Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Parit Raja, Batu Pahat, Johor (Malaysia)

    2015-07-22

    Black tilapia (Oreochromis mossambicus) fish head bones were evaluated for its possibilities in extracting gelatin. Head bones were subjected to pre-treatment with 3% of hydrochloric acid (HCl) for demineralization before undergoes thermal extraction process. The raw head bones were characterized via Scanning Electron Microscopy (SEM) in order to investigate the external and internal surface morphology. SEM images also reveal the presence of collagen fiber with 1 µm diameter in the head bone. The black tilapia fish head bones yields 5.75 % of gelatin in wet weight basis, indicating the possibility of this fish species as sources of gelatin. Further characterizations were done on both raw head bones and extracted gelatin through Fourier Transform Infrared Spectroscopy (FTIR) and proximate analysis. The head bones gelatin shows high protein (10.55%) and ash (3.11 %) content with low moisture. This further proves the effectiveness of demineralization and extraction method used. The black tilapia fish head bones are found to be a prospective source of gelatin with good chemical and functional properties.

  8. Enhancing the mechanical properties of electrospun polyester mats by heat treatment

    Directory of Open Access Journals (Sweden)

    M. Kancheva

    2015-01-01

    Full Text Available Microfibrous materials with a targeted design based on poly(L-lactic acid (PLA and poly(ε-caprolactone (PCL were prepared by electrospinning and by combining electrospinning and electrospraying. Several approaches were used: (i electrospinning of a common solution of the two polymers, (ii simultaneous electrospinning of two separate solutions of PLA and PCL, (iii electrospinning of PLA solution in conjunction with electrospraying of PCL solution, and (iv alternating layer-by-layer deposition by electrospinning of separate PLA and PCL solutions. The mats were heated at the melting temperature of PCL (60°", thus achieving melting of PCL fibers/particles and thermal sealing of the fibers. The mats subjected to thermal treatment were characterized by greater mean fiber diameters and reduced values of the water contact angle compared to the pristine mats. Heat treatment of the mats affected their thermal stability and led to an increase in the crystallinity degree of PLA incorporated in the mats, whereas that of PCL was reduced. All mats were characterized by enhanced mechanical properties after thermal treatment as compared to the non-treated fibrous materials.

  9. In vitro evaluation of crosslinked electrospun fish gelatin scaffolds.

    Science.gov (United States)

    Gomes, S R; Rodrigues, G; Martins, G G; Henriques, C M R; Silva, J C

    2013-04-01

    Gelatin from cold water fish skin was electrospun, crosslinked and investigated as a substrate for the adhesion and proliferation of cells. Gelatin was first dissolved in either water or concentrated acetic acid and both solutions were successfully electrospun. Cross-linking was achieved via three different routes: glutaraldehyde vapor, genipin and dehydrothermal treatment. Solution's properties (surface tension, electrical conductivity and viscosity) and scaffold's properties (chemical bonds, weight loss and fiber diameters) were measured. Cellular viability was analyzed culturing 3T3 fibroblasts plated on the scaffolds and grown up to 7 days. The cells were fixed and observed with SEM or stained for DNA and F-actin and observed with confocal microscopy. In all scaffolds, the cells attached and spread with varying degrees. The evaluation of cell viability showed proliferation of cells until confluence in scaffolds crosslinked by glutaraldehyde and genipin; however the rate of growth in genipin crosslinked scaffolds was slow, recovering only by day five. The results using the dehydrothermal treatment were the less satisfactory. Our results show that glutaraldehyde treated fish gelatin is the most suitable substrate, of the three studied, for fibroblast adhesion and proliferation. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Polyelectrolyte-Functionalized Nanofiber Mats Control the Collection and Inactivation of Escherichia coli

    Directory of Open Access Journals (Sweden)

    Katrina A. Rieger

    2016-04-01

    Full Text Available Quantifying the effect that nanofiber mat chemistry and hydrophilicity have on microorganism collection and inactivation is critical in biomedical applications. In this study, the collection and inactivation of Escherichia coli K12 was examined using cellulose nanofiber mats that were surface-functionalized using three polyelectrolytes: poly (acrylic acid (PAA, chitosan (CS, and polydiallyldimethylammonium chloride (pDADMAC. The polyelectrolyte functionalized nanofiber mats retained the cylindrical morphology and average fiber diameter (~0.84 µm of the underlying cellulose nanofibers. X-ray photoelectron spectroscopy (XPS and contact angle measurements confirmed the presence of polycations or polyanions on the surface of the nanofiber mats. Both the control cellulose and pDADMAC-functionalized nanofiber mats exhibited a high collection of E. coli K12, which suggests that mat hydrophilicity may play a larger role than surface charge on cell collection. While the minimum concentration of polycations needed to inhibit E. coli K12 was 800 µg/mL for both CS and pDADMAC, once immobilized, pDADMAC-functionalized nanofiber mats exhibited a higher inactivation of E. coli K12, (~97%. Here, we demonstrate that the collection and inactivation of microorganisms by electrospun cellulose nanofiber mats can be tailored through a facile polyelectrolyte functionalization process.

  11. Polyelectrolyte-Functionalized Nanofiber Mats Control the Collection and Inactivation of Escherichia coli

    Science.gov (United States)

    Rieger, Katrina A.; Porter, Michael; Schiffman, Jessica D.

    2016-01-01

    Quantifying the effect that nanofiber mat chemistry and hydrophilicity have on microorganism collection and inactivation is critical in biomedical applications. In this study, the collection and inactivation of Escherichia coli K12 was examined using cellulose nanofiber mats that were surface-functionalized using three polyelectrolytes: poly (acrylic acid) (PAA), chitosan (CS), and polydiallyldimethylammonium chloride (pDADMAC). The polyelectrolyte functionalized nanofiber mats retained the cylindrical morphology and average fiber diameter (~0.84 µm) of the underlying cellulose nanofibers. X-ray photoelectron spectroscopy (XPS) and contact angle measurements confirmed the presence of polycations or polyanions on the surface of the nanofiber mats. Both the control cellulose and pDADMAC-functionalized nanofiber mats exhibited a high collection of E. coli K12, which suggests that mat hydrophilicity may play a larger role than surface charge on cell collection. While the minimum concentration of polycations needed to inhibit E. coli K12 was 800 µg/mL for both CS and pDADMAC, once immobilized, pDADMAC-functionalized nanofiber mats exhibited a higher inactivation of E. coli K12, (~97%). Here, we demonstrate that the collection and inactivation of microorganisms by electrospun cellulose nanofiber mats can be tailored through a facile polyelectrolyte functionalization process. PMID:28773422

  12. Preservation and storage of prepared ballistic gelatine.

    Science.gov (United States)

    Mattijssen, E J A T; Alberink, I; Jacobs, B; van den Boogaard, Y

    2016-02-01

    The use of ballistic gelatine, generally accepted as a human muscle tissue simulant in wound ballistic studies, might be improved by adding a preservative (Methyl 4-hydroxybenzoate) which inhibits microbial growth. This study shows that replacing a part of the gelatine powder by the preservative does not significantly alter the penetration depth of projectiles. Storing prepared blocks of ballistic gelatine over time decreased the penetration depth of projectiles. Storage of prepared gelatine for 4 week already showed a significant effect on the penetration depth of projectiles. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  13. 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)

  14. Fatigue Characteristic of Chopped Strand Mat/Polyester Composite

    Directory of Open Access Journals (Sweden)

    I Made Astika

    2012-11-01

    Full Text Available The application of composite as an alternatif material to substitute of metal has better properties than metal such as light, high elasticity, corrosion and fatigue resistance. Some components in its application are subjected to millions of varying stress cycles that initiated to fatigue failure such as crack, delamination and fracture. The strength of composite is influenced by construction, fiber type, orientation and fiber fraction. The objective of this experiment is to investigate the fatigue characteristic on SCM composite. Material composite to be used is glass fiber with chopped strand mat (CSM as fiber and Yukalac 157 BQTN-EX with 1% hardener (Mexpox as matrix. The mold process was built with hand lay-up. Fiber volume fractions in composite are 40, 32 and 24 %. The tests to be done on composite are fatigue and tensile test. The research show that the increasing of fiber fraction in composite affects increasing of fatigue life, endurance limit and tensile strength. Fatigue failure modes of composite are debonding, matrix cracking, delamination and fiber fracture.

  15. Matérn thinned Cox processes

    DEFF Research Database (Denmark)

    Andersen, Ina Trolle; Hahn, Ute

    2016-01-01

    and hard core behaviour can be achieved by applying a dependent Matérn thinning to a Cox process. An exact formula for the intensity of a Matérn thinned shot noise Cox process is derived from the Palm distribution. For the more general class of Matérn thinned Cox processes, formulae for the intensity...

  16. Matérn thinned Cox processes

    DEFF Research Database (Denmark)

    Andersen, Ina Trolle; Hahn, Ute

    of clustering and hard core behaviour can be achieved by applying a dependent Matérn thinning to a Cox process. An exact formula for the intensity of a Matérn thinned shot noise Cox process is derived from the Palm distribution. For the more general class of Matérn thinned Cox processes, formulae...

  17. Ectomycorrhizal mats alter forest soil biogeochemistry

    Science.gov (United States)

    Laurel A. Kluber; Kathryn M. Tinnesand; Bruce A. Caldwell; Susie M. Dunham; Rockie R. Yarwood; Peter J. Bottomley; David D. Myrold

    2010-01-01

    Dense hyphal mats formed by ectomycorrhizal (EcM) fungi are prominent features in Douglas-fir forest ecosystems, and have been estimated to cover up to 40% of the soil surface in some forest stands. Two morphotypes of EcM mats have been previously described: rhizomorphic mats, which have thick hyphal rhizomorphs and are found primarily in the organic horizon, and...

  18. Radiation as a processing aid for upgrading gelatin and gelatin capsules

    International Nuclear Information System (INIS)

    Patel, K.M.; Tantry, M.; Sharma, G.; Gopal, N.G.S.

    1979-01-01

    Gelatin for pharmaceutical use should not contain more than 1000 microorganisms per gram and must not contain pathogenic microorganisms like Salmonella species and E.Coli. For some biological studies spore free gelatin is essential. Locally available gelatin and gelatin capsules have been found to contain a good number of microorganisms. Gelatin and its capsules containing different colours were exposed to graded doses of radiation and stored at different temperatures. They were then examined for microbial content, disintegration characteristics, pH, viscosity and colour change. The study shows that radiation treatment is useful to upgrade microbiologically both gelatin and its capsules. This technique provides apparently a useful and economic method for producing spore free gelatin which in commerce is relatively expensive. (auth.)

  19. Radiation as a processing aid for upgrading gelatin and gelatin capsules

    Energy Technology Data Exchange (ETDEWEB)

    Patel, K M; Tantry, M; Sharma, G; Gopal, N G.S. [Bhabha Atomic Research Centre, Bombay (India). ISOMED

    1979-01-01

    Gelatin for pharmaceutical use should not contain more than 1000 microorganisms per gram and must not contain pathogenic microorganisms like Salmonella species and E.Coli. For some biological studies spore free gelatin is essential. Locally available gelatin and gelatin capsules have been found to contain a good number of microorganisms. Gelatin and its capsules containing different colours were exposed to graded doses of radiation and stored at different temperatures. They were then examined for microbial content, disintegration characteristics, pH, viscosity and colour change. The study shows that radiation treatment is useful to upgrade microbiologically both gelatin and its capsules. This technique provides apparently a useful and economic method for producing spore free gelatin which in commerce is relatively expensive.

  20. Gold nanoparticles–gelatinhybrid fibers with bright photoluminescence

    DEFF Research Database (Denmark)

    Liu, Shuiping; Tan, Lianjiang; Li, Xiaoqiang

    2014-01-01

    acid and gave rise to in situ synthesis of GNPs in the spinning solutions. The GNPs–gelatin fibers were fabricated by electrospinning the spinning solutions. The GNPs were encapsulated in the fibers, which endowed the fibers photoluminescence (PL) characteristics. A variety of experiments were...

  1. Mechanical and physical properties of wood fiber-reinforced, sulfur-based wood composites

    Science.gov (United States)

    Chung-Yun Hse; Ben S. Bryant

    1993-01-01

    Sulfur-based composite was made from sulfur impregnated, oven dried, wet-formed fiber mats. The fiber mats consisted of a 50/50 mixture of recycled newsprint pulp and mechanical hardwood pulp from several species made from chips in a laboratory refiner. The thickness of the composites was 0.125 inch and the specific gravity of the unimpregnated fiber mat was 0.2. The...

  2. Enzymatic degradation of polycaprolactone–gelatin blend

    International Nuclear Information System (INIS)

    Banerjee, Aditi; Chatterjee, Kaushik; Madras, Giridhar

    2015-01-01

    Blends of polycaprolactone (PCL), a synthetic polymer and gelatin, natural polymer offer a optimal combination of strength, water wettability and cytocompatibility for use as a resorbable biomaterial. The enzymatic degradation of PCL, gelatin and PCL–gelatin blended films was studied in the presence of lipase (Novozym 435, immobilized) and lysozyme. Novozym 435 degraded the PCL films whereas lysozyme degraded the gelatin. Though Novozym 435 and lysozyme individually could degrade PCL–gelatin blended films, the combination of these enzymes showed the highest degradation of these blended films. Moreover, the enzymatic degradation was much faster when fresh enzymes were added at regular intervals. The changes in physico-chemical properties of polymer films due to degradation were studied by scanning electron microscopy, Fourier transform infrared spectroscopy and differential scanning calorimetry. These results have important implications for designing resorbable biomedical implants. (paper)

  3. Projet ViscoMatData

    OpenAIRE

    ENGUENG,; ABIB,

    2009-01-01

    ViscoMatData est un logiciel extranet d'une gestion d'une base de données multilingue sur les propriétés des matériaux viscoélastiques des chaussées. Ce rapport constitue l'un des livrables de la deuxième partie de ce projet. Pour présenter le travail réalisé durant cette deuxième partie, nous commencerons par faire un rappel sur le contexte du projet et le projet et le projet lui-même. Puis, nous nous intéresserons à l'architecture mise en place pour le développement, la réalisation et nous ...

  4. Preface - BraMat 2017

    Science.gov (United States)

    Munteanu, Daniel

    2018-04-01

    The main goal of the BraMat 2017 Conference was, as for the previous editions, to stimulate an international exchange of information in the field of materials science and engineering and to establish future research directions. The main topics of this edition included: ​Metallic materials (Section I), Biomaterials (Section II), Ceramics, polymers and composite materials (Section III), Surface engineering (Section IV), Nanomaterials (Section V), Welding engineering (Section VI), Safety engineering (Section VII), and Magnesium science and engineering (Section VIII).

  5. Safety Protocols at MAT Lab

    International Nuclear Information System (INIS)

    Wadawale, A.; Chopade, S.; Chaudhury, K.; Pal, M.K.; Kushwah, N.; Shah, A.Y.; Kedarnath, G.; Priyadarsini, K.I.; Jain, V.K.

    2017-01-01

    MAT Lab of Chemistry Division, BARC (A Class 10000 Clean room laboratory) has been in operation since 2004 for process development of ultra-purification of several strategically important materials (Ga, As, Sb, In, CsI and Ge) and synthesis of their organometallic compounds. Of these, work related to purification of As, Sb, and In, has been discontinued. Due to high toxicity and pyrophoric nature of some of the compounds, stringent safety regulations were formulated and subsequently implemented by the division

  6. Determine Age-structure of Gelatinous Zooplankton Using Optical Coherence Tomography

    Science.gov (United States)

    Bi, H.; Shahrestani, S.; He, Y.

    2016-02-01

    Gelatinous are delicate and transparent by nature, but are conspicuous in many ecosystems when in bloom. Their proliferations are a bothersome and costly nuisance and influencing important food webs and species interactions. More importantly, gelatinous zooplankton respond to climate change rapidly and understanding their upsurge needs information on their recruitment and population dynamics which in turn require their age-structure. However, ageing gelatinous zooplankton is often restricted by the fact that they shrink under unfavorable conditions. In the present study, we examine the potential of using optical coherence tomography (OCT) to age gelatinous zooplankton. OCT is a non-invasive imaging technique that uses light waves to examine 2D or 3D structure of target objects at a resolution of 3-5 µm. We were able to successfully capture both 3D and 2D images of sea nettle muscle fibers. Preliminary results on ctenophores will be discussed. Overall, this non-destructive sampling allows us to scan and capture images of mesoglea from jellyfish cultured in the lab, using the same individual repeatedly through time, documenting its growth which will provide precise measurements to construct an age key that will be applied to gelatinous zooplankton captured in the field. Coupled with information on abundance, we can start to quantify their recruitment timing and success rate.

  7. Foam-mat drying technology: A review.

    Science.gov (United States)

    Hardy, Z; Jideani, V A

    2017-08-13

    This article reviews various aspects of foam-mat drying such as foam-mat drying processing technique, main additives used for foam-mat drying, foam-mat drying of liquid and solid foods, quality characteristics of foam-mat dried foods, and economic and technical benefits for employing foam-mat drying. Foam-mat drying process is an alternative method that allows the removal of water from liquid materials and pureed materials. In this drying process, a liquid material is converted into foam that is stable by being whipped after adding an edible foaming agent. The stable foam is then spread out in sheet or mat and dried by using hot air (40-90°C) at atmospheric pressure. Methyl cellulose (0.25-2%), egg white (3-20%), maltodextrin (0.5-05%), and gum Arabic (2-9%) are the commonly utilized additives for the foam-mat drying process at the given range, either combined together for their effectiveness or individual effect. The foam-mat drying process is suitable for heat sensitive, viscous, and sticky products that cannot be dried using other forms of drying methods such as spray drying because of the state of product. More interest has developed for foam-mat drying because of the simplicity, cost effectiveness, high speed drying, and improved product quality it provides.

  8. Woven Hybrid Composites - Tensile and Flexural Properties of Jute Mat Fibres with Epoxy Composites

    Science.gov (United States)

    Gopal, P.; Bupesh Raja, V. K.; Chandrasekaran, M.; Dhanasekaran, C.

    2017-03-01

    The jute mat fibers are fabricated with several layers of fiber with opposite orientation in addition with coconut shell powder and resins. In current trends, metallic components are replaced by natural fibers because of the inherent properties such as light in weight, easy to fabricate, less cost and easy availability. This material has high strength and withstands the load. In this investigation the plates are made without stitching the fiber. The result of tensile strength and flexural strength are compared with nano material (coconut shell powder).

  9. Antibacterial electrospun chitosan-polyethylene oxide nanocomposite mats containing ZIF-8 nanoparticles.

    Science.gov (United States)

    Kohsari, Iraj; Shariatinia, Zahra; Pourmortazavi, Seied Mahdi

    2016-10-01

    Antimicrobial chitosan-polyethylene oxide (CS-PEO) nanofiber mats loaded with 3, 5 and 10% (w/w) of zeolitic imidazolate framework-8 nanoparticles (ZIF-8 NPs, ∼60nm diameter) were developed by electrospinning technique. The CS-PEO-GA-3% ZIF-8 NPs crosslinked with glutaraldehyde (GA) vapor was also prepared. The electrospun mats were characterized by various analysis including FE-SEM, EDAX, elemental mapping, FT-IR, contact angle, TGA/DSC as well as tensile strength analysis. The nanofibers had average diameters within the range ∼70-120nm. Antimicrobial activities of the CS-PEO and CS-PEO-3% ZIF-8 mats were evaluated by the viable cell-counting method for determining their effectiveness in reducing or halting the growth of Staphylococcus aureus and Escherichia coli bacteria so that the CS-PEO mat containing 3% ZIF-8 revealed 100% bactericidal activity against both kinds of bacteria. The crosslinked CS-PEO-GA-3% ZIF-8 NPs sample was less thermally stable but more hydrophilic than its related non-crosslinked mat reflecting there was no need to crosslink the fibers using a chemical crosslinker having adverse effects. The highest hydrophobicity and appropriate thermal and tensile properties of CS-PEO-3% ZIF-8 NPs among those of the mats including 5 and 10% ZIF-8 NPs suggested that the mentioned mat is the most suitable sample for food coating applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Modification of PLGA Nanofibrous Mats by Electron Beam Irradiation for Soft Tissue Regeneration

    Directory of Open Access Journals (Sweden)

    Jae Baek Lee

    2015-01-01

    Full Text Available Biodegradable poly(lactide-co-glycolide (PLGA has found widespread use in modern medical practice. However, the degradation rate of PLGA should be adjusted for specific biomedical applications such as tissue engineering, drug delivery, and surgical implantation. This study focused on the effect of electron beam radiation on nanofibrous PLGA mats in terms of physical properties and degradation behavior with cell proliferation. PLGA nanofiber mats were prepared by electrospinning, and electron beam was irradiated at doses of 50, 100, 150, 200, 250, and 300 kGy. PLGA mats showed dimensional integrity after electron beam irradiation without change of fiber diameter. The degradation behavior of a control PLGA nanofiber (0 kGy and electron beam-irradiated PLGA nanofibers was analyzed by measuring the molecular weight, weight loss, change of chemical structure, and fibrous morphology. The molecular weight of the PLGA nanofibers decreased with increasing electron beam radiation dose. The mechanical properties of the PLGA nanofibrous mats were decreased with increasing electron beam irradiation dose. Cell proliferation behavior on all electron beam irradiated PLGA mats was similar to the control PLGA mats. Electron beam irradiation of PLGA nanofibrous mats is a potentially useful approach for modulating the biodegradation rate of tissue-specific nonwoven nanofibrous scaffolds, specifically for soft tissue engineering applications.

  11. Extraction and physicochemical characterization of broiler (Gallus gallus domesticus) skin gelatin compared to commercial bovine gelatin.

    Science.gov (United States)

    Aykin-Dinçer, E; Koç, A; Erbas, M

    2017-09-01

    Gelatin was extracted from broiler (Gallus gallus domesticus) skins and analyzed to compare its physicochemical properties with those of commercial bovine gelatin. The average yield of broiler skin gelatin was 6.5% on a wet weight basis. Broiler skin gelatin had more α1-and α2-chains than β-chain and contained high molecular weight (γ-chain) polymers. Glycine was the dominant amino acid in broiler skin gelatin (20.26%), followed by proline (Pro) (15.12%) then hydroxyproline (Hyp) (11.36%). Compared to commercial bovine gelatin, broiler skin gelatin had less total imino acids (Pro and Hyp) but a higher (33.65 vs. 31.38°C) melting temperature (P commercial bovine gelatins appeared to be associated with differences in their amino acid composition and molecular weight distribution. The sensory evaluation results revealed that broiler skin gelatin could be a potential alternative to commercial bovine gelatin, useful in various food products. © 2017 Poultry Science Association Inc.

  12. Properties of foam and composite materials made o starch and cellulose fiber

    Science.gov (United States)

    Composite materials were made of starch and cellulose fibers. Pre-gelatinized starch was effective in dispersing pulp fiber in a starch matrix to form a viscous starch/fiber dough. The starch/fiber dough was a useful feedstock for various composite foam and plastic materials. Viscous blends of star...

  13. Electrospun Zein/Gelatin Scaffold-Enhanced Cell Attachment and Growth of Human Periodontal Ligament Stem Cells

    Directory of Open Access Journals (Sweden)

    Fanqiao Yang

    2017-10-01

    Full Text Available Periodontitis is a widespread dental disease affecting 10 to 15% of worldwide adult population, yet the current treatments are far from satisfactory. The human periodontal ligament stem cell is a promising potential seed cell population type in cell-based therapy and tissue regeneration, which require appropriate scaffold to provide a mimic extracellular matrix. Zein, a native protein derived from corn, has an excellent biodegradability, and therefore becomes a hotspot on research and application in the field of biomaterials. However, the high hydrophobicity of zein is unfavorable for cell adhesion and thus greatly limits its use. In this study, we fabricate co-electrospun zein/gelatin fiber scaffolds in order to take full advantages of the two natural materials and electrospun fiber structure. Zein and gelatin in four groups of different mass ratios (100:00, 100:20, 100:34, 100:50, and dissolved the mixtures in 1,1,1,3,3,3-hexafluoro-2-propanol, then produced membranes by electrospinning. The results showed that the scaffolds were smooth and homogeneous, as shown in scanning electron micrographs. The diameter of hybrid fibers was increased from 69 ± 22 nm to 950 ± 356 nm, with the proportion of gelatin increase. The cell affinity of zein/gelatin nanofibers was evaluated by using human periodontal ligament stem cells. The data showed that hydrophilicity and cytocompatibility of zein nanofibers were improved by blended gelatin. Taken together, our results indicated that the zein/gelatin co-electrospun fibers had sufficient mechanical properties, satisfied cytocompatibility, and can be utilized as biological scaffolds in the field of tissue regeneration.

  14. Solution-blown nanofiber mats from fish sarcoplasmic protein

    DEFF Research Database (Denmark)

    Sett, S.; Boutrup Stephansen, Karen; Yarin, A.L.

    2016-01-01

    In the present work, solution-blowing was adopted to form nanofibers from fish sarcoplasmic proteins (FSPs). Nanofiber mats containing different weight ratios (up to 90/10) of FSP in the FSP/nylon 6 blended nanofibers were formed from formic acid solutions, and compared to electrospun fibers made...... that the production rate of solution-blowing was increased 30-fold in relation to electrospinning. Overall, this study reveals FSP as an interesting biopolymeric alternative to synthetic polymers, and the introduction of FSP to nylon 6 provides a composite with controlled properties....

  15. Performance of high amylose starch-composited gelatin films influenced by gelatinization and concentration.

    Science.gov (United States)

    Wang, Wenhang; Wang, Kun; Xiao, Jingdong; Liu, Yaowei; Zhao, Yana; Liu, Anjun

    2017-01-01

    In order to study the impact of starch in film performance, high amylose corn starch was composited in gelatin films under different gelatinization conditions and, in high and low concentrations (10 and 50wt.%). It was found that hot water gelatinized starch (Gel-Shw) increased film mechanical strength and was dependent upon the starch concentration. The addition of an alkali component to the starch significantly enhanced the swelling of the starch granules and expedited the gelatinization process. Incorporation of starch, especially the alkalized starch (Sha), into the gelatin films decreased film solubility which improved its water resistance and water vapor permeability (WVP). Multiple techniques (DSC, TGA, FT-IR, and XRD) were used to characterize the process and results, including the crosslinking of the dissolved starch molecules and the particles formed from gelatinized starch during retrogradation process, which played an important role in improving the thermal stability of the composited gelatin films. Overall, the starch-gelatin composition provides a potential approach to improve gelatin film performance and benefit its applications in the food industry. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. MatLab Script and Functional Programming

    Science.gov (United States)

    Shaykhian, Gholam Ali

    2007-01-01

    MatLab Script and Functional Programming: MatLab is one of the most widely used very high level programming languages for scientific and engineering computations. It is very user-friendly and needs practically no formal programming knowledge. Presented here are MatLab programming aspects and not just the MatLab commands for scientists and engineers who do not have formal programming training and also have no significant time to spare for learning programming to solve their real world problems. Specifically provided are programs for visualization. The MatLab seminar covers the functional and script programming aspect of MatLab language. Specific expectations are: a) Recognize MatLab commands, script and function. b) Create, and run a MatLab function. c) Read, recognize, and describe MatLab syntax. d) Recognize decisions, loops and matrix operators. e) Evaluate scope among multiple files, and multiple functions within a file. f) Declare, define and use scalar variables, vectors and matrices.

  17. Surface modification of nanofibrous polycaprolactone/gelatin composite scaffold by collagen type I grafting for skin tissue engineering.

    Science.gov (United States)

    Gautam, Sneh; Chou, Chia-Fu; Dinda, Amit K; Potdar, Pravin D; Mishra, Narayan C

    2014-01-01

    In the present study, a tri-polymer polycaprolactone (PCL)/gelatin/collagen type I composite nanofibrous scaffold has been fabricated by electrospinning for skin tissue engineering and wound healing applications. Firstly, PCL/gelatin nanofibrous scaffold was fabricated by electrospinning using a low cost solvent mixture [chloroform/methanol for PCL and acetic acid (80% v/v) for gelatin], and then the nanofibrous PCL/gelatin scaffold was modified by collagen type I (0.2-1.5wt.%) grafting. Morphology of the collagen type I-modified PCL/gelatin composite scaffold that was analyzed by field emission scanning electron microscopy (FE-SEM), showed that the fiber diameter was increased and pore size was decreased by increasing the concentration of collagen type I. Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric (TG) analysis indicated the surface modification of PCL/gelatin scaffold by collagen type I immobilization on the surface of the scaffold. MTT assay demonstrated the viability and high proliferation rate of L929 mouse fibroblast cells on the collagen type I-modified composite scaffold. FE-SEM analysis of cell-scaffold construct illustrated the cell adhesion of L929 mouse fibroblasts on the surface of scaffold. Characteristic cell morphology of L929 was also observed on the nanofiber mesh of the collagen type I-modified scaffold. Above results suggest that the collagen type I-modified PCL/gelatin scaffold was successful in maintaining characteristic shape of fibroblasts, besides good cell proliferation. Therefore, the fibroblast seeded PCL/gelatin/collagen type I composite nanofibrous scaffold might be a potential candidate for wound healing and skin tissue engineering applications. © 2013.

  18. Characterization of Fish Skin Gelatin Yellowfin Tuna

    Directory of Open Access Journals (Sweden)

    Mala Nurilmala

    2017-08-01

    Full Text Available Gelatin is one of the products which become a necessity for various industries, i.e. food and non-food industries. The application of gelatin has been increasing year by year in Indonesia. However, there is nogelatin industry in Indonesia so far. Thus, it is necessary to find an alternative source of gelatin, especially from fishery by products.Thus, the purpose of this research was to extract fish skin gelatin of yellowfin tuna with temperature treatments (55, 65 and 75oC. In addition, the properties of resulted gelatin were determined including yield, pH, gel strength, viscosity, functional groups, molecular weight profiles, and amino acid composition. The extraction at 75oC was chosen as the best result. The yield was 17%; pH 5.3; gel strength 1789.55 gf, viscosity 104.2 Cp, respectively. There was functional group amide A, I, II, dan III. SDS-PAGE showed β, α1 dan α2 bands for tuna skin gelatin. In addition, the main amino acids were glycine and proline.

  19. Anaphylaxis to gelatin-containing rectal suppositories.

    Science.gov (United States)

    Sakaguchi, M; Inouye, S

    2001-12-01

    Some children--though the number is few-have been sensitized with gelatin. To investigate the relationship between the presence of antigelatin IgE and anaphylaxis to gelatin-containing rectal suppository, we measured antigelatin IgE in the sera of the children with anaphylaxis. Ten children showed systemic allergic reactions, including anaphylaxis, to a chloral hydrate rectal suppository containing gelatin (231 mg/dose) that had been used as a sedative. These children's clinical histories and serum samples were submitted from physicians to the National Institute of Infectious Diseases during a 2-year period from 1996 to 1997. Of the 10 children, 5 showed apparent anaphylaxis, including hypotension and/or cyanosis, along with urticaria or wheezing; 2 showed both urticaria and wheezing without hypotension or cyanosis; the other 3 showed only urticaria. All of the children had antigelatin IgE (mean value +/- SD, 7.9 +/- 8.4 Ua/mL). As a control, samples from 250 randomly selected children had no antigelatin IgE. These findings suggest that the 10 children's systemic allergic reactions to this suppository were caused by the gelatin component. Gelatin-containing suppositories must be used with the same caution as gelatin-containing vaccines and other medications.

  20. Enzyme-Gelatin Electrochemical Biosensors: Scaling Down

    Directory of Open Access Journals (Sweden)

    Hendrik A. Heering

    2012-03-01

    Full Text Available In this article we investigate the possibility of scaling down enzyme-gelatin modified electrodes by spin coating the enzyme-gelatin layer. Special attention is given to the electrochemical behavior of the selected enzymes inside the gelatin matrix. A glassy carbon electrode was used as a substrate to immobilize, in the first instance, horse heart cytochrome c (HHC in a gelatin matrix. Both a drop dried and a spin coated layer was prepared. On scaling down, a transition from diffusion controlled reactions towards adsorption controlled reactions is observed. Compared to a drop dried electrode, a spin coated electrode showed a more stable electrochemical behavior. Next to HHC, we also incorporated catalase in a spin coated gelatin matrix immobilized on a glassy carbon electrode. By spincoating, highly uniform sub micrometer layers of biocompatible matrices can be constructed. A full electrochemical study and characterization of the modified surfaces has been carried out. It was clear that in the case of catalase, gluteraldehyde addition was needed to prevent leaking of the catalase from the gelatin matrix.

  1. Electrospun polycaprolactone/gelatin composites with enhanced cell–matrix interactions as blood vessel endothelial layer scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Yong-Chao [National Center for International Research of Micro-Nano Molding Technology, Zhengzhou University, Zhengzhou (China); School of Mechanics and Engineering Science, Zhengzhou University, Zhengzhou (China); Department of Mechanical Engineering, University of Wisconsin-Madison, WI (United States); Wisconsin Institute for Discovery, University of Wisconsin-Madison, WI (United States); Jiang, Lin [National Center for International Research of Micro-Nano Molding Technology, Zhengzhou University, Zhengzhou (China); Department of Mechanical Engineering, University of Wisconsin-Madison, WI (United States); Wisconsin Institute for Discovery, University of Wisconsin-Madison, WI (United States); Huang, An [South China University of Technology, Guangzhou (China); Department of Mechanical Engineering, University of Wisconsin-Madison, WI (United States); Wisconsin Institute for Discovery, University of Wisconsin-Madison, WI (United States); Wang, Xiao-Feng [National Center for International Research of Micro-Nano Molding Technology, Zhengzhou University, Zhengzhou (China); School of Mechanics and Engineering Science, Zhengzhou University, Zhengzhou (China); Li, Qian [National Center for International Research of Micro-Nano Molding Technology, Zhengzhou University, Zhengzhou (China); Turng, Lih-Sheng, E-mail: turng@engr.wisc.edu [Department of Mechanical Engineering, University of Wisconsin-Madison, WI (United States); Wisconsin Institute for Discovery, University of Wisconsin-Madison, WI (United States)

    2017-02-01

    During the fabrication of tissue engineering scaffolds and subsequent tissue regeneration, surface bioactivity is vital for cell adhesion, spreading, and proliferation, especially for endothelium dysfunction repair. In this paper, synthetic polymer polycaprolactone (PCL) was blended with natural polymer gelatin at four different weight ratios followed by crosslinking (i.e., 100:0, 70:30, 50:50, 30:70, labeled as PCL-C, P7G3-C, P5G5-C, and P3G7-C) to impart enhanced bioactivity and tunable mechanical properties. The PCL/gelatin blends were first dissolved in 2,2,2-trifluroethanol (TFE) and supplementary acetic acid (1% relative to TFE) solvent, electrospun, and then cross-linked to produce PBS-proof fibrous scaffolds. Scanning electron micrographs (SEM) indicated that fibers of each sample were smooth and homogeneous, with the fiber diameters increasing from 1.01 ± 0.51 μm to 1.61 ± 0.46 μm as the content of gelatin increased. While thermal resistance and crystallization of the blends were affected by the presence of gelatin, as reflected by differential scanning calorimetry (DSC) results, water contact angle (WCA) tests confirmed that the scaffold surfaces became more hydrophilic. Tensile tests showed that PCL-C and P7G3-C scaffolds had mechanical properties comparable to those of human coronary arteries. As for cytocompatibility, skeleton staining images showed that human mesenchymal stem cells (hMSCs) had more favorable binding sites on PCL/gelatin scaffolds than those on PCL scaffolds. Cell proliferation assays revealed that P7G3-C scaffolds could support the most number of hMSCs. The results of this study demonstrated the enhanced cell-matrix interactions and potential use of electrospun PCL/gelatin scaffolds in the tissue engineering field, especially in wound dressings and endothelium regeneration. - Highlights: • Aqueous solution-resistant PCL/gelatin scaffolds were made via electrospinning. • PCL/gelatin composite scaffolds have tunable biophysical

  2. Electrospun polycaprolactone/gelatin composites with enhanced cell–matrix interactions as blood vessel endothelial layer scaffolds

    International Nuclear Information System (INIS)

    Jiang, Yong-Chao; Jiang, Lin; Huang, An; Wang, Xiao-Feng; Li, Qian; Turng, Lih-Sheng

    2017-01-01

    During the fabrication of tissue engineering scaffolds and subsequent tissue regeneration, surface bioactivity is vital for cell adhesion, spreading, and proliferation, especially for endothelium dysfunction repair. In this paper, synthetic polymer polycaprolactone (PCL) was blended with natural polymer gelatin at four different weight ratios followed by crosslinking (i.e., 100:0, 70:30, 50:50, 30:70, labeled as PCL-C, P7G3-C, P5G5-C, and P3G7-C) to impart enhanced bioactivity and tunable mechanical properties. The PCL/gelatin blends were first dissolved in 2,2,2-trifluroethanol (TFE) and supplementary acetic acid (1% relative to TFE) solvent, electrospun, and then cross-linked to produce PBS-proof fibrous scaffolds. Scanning electron micrographs (SEM) indicated that fibers of each sample were smooth and homogeneous, with the fiber diameters increasing from 1.01 ± 0.51 μm to 1.61 ± 0.46 μm as the content of gelatin increased. While thermal resistance and crystallization of the blends were affected by the presence of gelatin, as reflected by differential scanning calorimetry (DSC) results, water contact angle (WCA) tests confirmed that the scaffold surfaces became more hydrophilic. Tensile tests showed that PCL-C and P7G3-C scaffolds had mechanical properties comparable to those of human coronary arteries. As for cytocompatibility, skeleton staining images showed that human mesenchymal stem cells (hMSCs) had more favorable binding sites on PCL/gelatin scaffolds than those on PCL scaffolds. Cell proliferation assays revealed that P7G3-C scaffolds could support the most number of hMSCs. The results of this study demonstrated the enhanced cell-matrix interactions and potential use of electrospun PCL/gelatin scaffolds in the tissue engineering field, especially in wound dressings and endothelium regeneration. - Highlights: • Aqueous solution-resistant PCL/gelatin scaffolds were made via electrospinning. • PCL/gelatin composite scaffolds have tunable biophysical

  3. Halal authenticity of gelatin using species-specific PCR.

    Science.gov (United States)

    Shabani, Hessam; Mehdizadeh, Mehrangiz; Mousavi, Seyed Mohammad; Dezfouli, Ehsan Ansari; Solgi, Tara; Khodaverdi, Mahdi; Rabiei, Maryam; Rastegar, Hossein; Alebouyeh, Mahmoud

    2015-10-01

    Consumption of food products derived from porcine sources is strictly prohibited in Islam. Gelatin, mostly derived from bovine and porcine sources, has many applications in the food and pharmaceutical industries. To ensure that food products comply with halal regulations, development of valid and reliable analytical methods is very much required. In this study, a species-specific polymerase chain reaction (PCR) assay using conserved regions of mitochondrial DNA (cytochrome b gene) was performed to evaluate the halal authenticity of gelatin. After isolation of DNA from gelatin powders with known origin, conventional PCR using species-specific primers was carried out on the extracted DNA. The amplified expected PCR products of 212 and 271 bp were observed for porcine and bovine gelatin, respectively. The sensitivity of the method was tested on binary gelatin mixtures containing 0.1%, 1%, 10%, and 100% (w/w) of porcine gelatin within bovine gelatin and vice versa. Although most of the DNA is degraded due to the severe processing steps of gelatin production, the minimum level of 0.1% w/w of both porcine and bovine gelatin was detected. Moreover, eight food products labeled as containing bovine gelatin and eight capsule shells were subjected to PCR examination. The results showed that all samples contained bovine gelatin, and the absence of porcine gelatin was verified. This method of species authenticity is very useful to verify whether gelatin and gelatin-containing food products are derived from halal ingredients. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Sedimentology, Mineralogy, Morphology, and Characterization of Purple Non-Sulfur Bacteria Communities from Modern Hypersaline Microbial Mats in Puerto Rico and the Virgin Islands

    Science.gov (United States)

    Rodriguez Colon, B. J.; Rivera-Lopez, E. O.; Ramirez-Martinez, W. R.; Rios-Velazquez, C.; Perez-Valentin, K. A.

    2017-12-01

    Microbial mats are organosedimentary structures which house complex guilds of microbial communities, held together by a gelatinous exopolymeric substance (EPS). This biofilm contributes to the formation of laminations by binding and trapping sediments, as well as in-situ organomineralization. Microbial mats commonly thrive in extreme habitats, such as the hypersaline environments, which have been studied throughout several coastal regions in the Caribbean. This project aims to study the morphology, sedimentology, and mineralogy of five different modern hypersaline microbial mats from Puerto Rico and Anegada that have not yet been studied, to assess their differences/similarities. At the same time, we intent to isolate and characterize purple non-sulfur bacteria (PNSB), which is an anoxyphototrophic microorganism that contributes to the pink pigmentation observed in the second layer of a typical microbial mat. Different layers within each mat were separated, dissected and dissolved to remove all organic material. The resulting sediment was then analyzed mineralogically using X-ray diffraction, and used to make petrographic thin sections. To isolate PNSB candidates, serial dilutions followed by filtration were performed to extracted sections from the pink layer of each mat. The samples were planted in Petri dishes with marine media and placed in Anaerobic Jars. Colonies Descriptions, Gram stain and molecular analysis using 16S rDNA gene was performed. Preliminary results show a diversity of mat morphologies throughout the ponds, similar to what has been observed in other hypersaline ponds and marshes in the Caribbean. Sedimentary analysis shows that the mats from Puerto Rico have similar allochthonous material (e.g. Halimeda sp. fragments). Microcodium fabrics, conoform structures, and hemispheroidal morphologies were observed as well. In Anegada, lithified microbialites were observed in the Red Pond location. Mineralogically, all samples were similar except for the

  5. Thermal characterisation of gelatin extracted from yellowfin tuna skin and commercial mammalian gelatin.

    Science.gov (United States)

    Rahman, Mohammad Shafiur; Al-Saidi, Ghalib Said; Guizani, Nejib

    2008-05-15

    Glass transition and other thermal characteristics of gelatin from different sources were studied by differential scanning calorimetry (DSC) and modulated DSC (MDSC). The initial glass transition temperatures of equilibrated gelatin samples at 11.3% relative humidity, determined from reversible heat flow thermogram of MDSC, were 23, 75 and 59°C, respectively, for tuna skin, bovine and porcine gelatin. When gelatin samples were equilibrated at higher relative humidity of 52.9%, glass transition temperature of fish skin and bovine gelatin decreased to -3 and 57°C, respectively. Further increase of equilibration relative humidity to 75.3% showed increased value in the case of tuna skin, whereas bovine and porcine did not show any significant change. DSC and MDSC results indicated that tuna gelatin showed lower glass transition compared to mammalian source gelatin equilibrated at the same constant relative humidity. In general glass transition measured by DSC was found lower than the values measured by MDSC. The results in this study showed that the degree of plasticization varied with the source of gelatin as well as their extraction methods. Copyright © 2007 Elsevier Ltd. All rights reserved.

  6. Bagging system, soil stabilization mat, and tent frame for a lunar base

    Science.gov (United States)

    1990-01-01

    Georgia Tech's School of Textile and Fiber Engineering and School of Mechanical Engineering participated in four cooperative design efforts this year. Each of two interdisciplinary teams designed a system consisting of a lunar regolith bag and an apparatus for filling this bag. The third group designed a mat for stabilization of lunar soil during takeoff and landing, and a method for packaging and deploying this mat. Finally, the fourth group designed a sunlight diffusing tent to be used as a lunar worksite. Summaries of these projects are given.

  7. Hierarchically Structured Electrospun Fibers

    Directory of Open Access Journals (Sweden)

    Nicole E. Zander

    2013-01-01

    Full Text Available Traditional electrospun nanofibers have a myriad of applications ranging from scaffolds for tissue engineering to components of biosensors and energy harvesting devices. The generally smooth one-dimensional structure of the fibers has stood as a limitation to several interesting novel applications. Control of fiber diameter, porosity and collector geometry will be briefly discussed, as will more traditional methods for controlling fiber morphology and fiber mat architecture. The remainder of the review will focus on new techniques to prepare hierarchically structured fibers. Fibers with hierarchical primary structures—including helical, buckled, and beads-on-a-string fibers, as well as fibers with secondary structures, such as nanopores, nanopillars, nanorods, and internally structured fibers and their applications—will be discussed. These new materials with helical/buckled morphology are expected to possess unique optical and mechanical properties with possible applications for negative refractive index materials, highly stretchable/high-tensile-strength materials, and components in microelectromechanical devices. Core-shell type fibers enable a much wider variety of materials to be electrospun and are expected to be widely applied in the sensing, drug delivery/controlled release fields, and in the encapsulation of live cells for biological applications. Materials with a hierarchical secondary structure are expected to provide new superhydrophobic and self-cleaning materials.

  8. Electron beam effects on gelatin polymer

    Energy Technology Data Exchange (ETDEWEB)

    Inamura, Patricia Y.; Shimazaki, Kleber; Souza, Clecia de M.; Moura, Esperidiana A.B.; Mastro, Nelida L. del, E-mail: patyoko@yahoo.co [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Colombo, Maria A., E-mail: mascolombo@yahoo.com.b [Faculdade de Tecnologia da Zona Leste, Sao Paulo, SP (Brazil)

    2009-07-01

    The main field of electron-beam radiation processing applications is the modification of polymeric material. Polymer development includes new pathways to produce natural polymers with better mechanical and barrier properties and thermal stability. The aim of this paper was to investigate the behavior of a gelatin/acrylamide polymer treated by electron-beam radiation. Gelatin is a heterogeneous mixture of water-soluble proteins of high average molecular mass derived by hydrolytic action from animal collagen, a fibrous insoluble protein, which is widely found in nature as the major constituent of skin, bones and connective tissue. Hydrolyzed collagen is composed of a unique sequence of amino acids, characterized particularly by the high content of glycine, proline and hydroxyproline. Among biomaterials, gelatin is an interesting material because is a partially crystalline polymer and has a relatively low melting point. Samples of gelatin together with glycerin as plasticizer and acrylamide as copolymer were irradiated with doses of 10 kGy and 40 kGy, using an electron beam accelerator, dose rate 22.41kGy/s, at room temperature in presence of air. After irradiation, some preliminary analyses were done like viscometry, texture analyses and colorimetry. The results of the diverse tests showed changes that can be ascribed to radiation-induced crosslinking. The electron-beam processed acrylamide-gelatin polymer using glycerin as plasticizer must be first extensively characterized before to be used for general applications. (author)

  9. Electron beam effects on gelatin polymer

    International Nuclear Information System (INIS)

    Inamura, Patricia Y.; Shimazaki, Kleber; Souza, Clecia de M.; Moura, Esperidiana A.B.; Mastro, Nelida L. del; Colombo, Maria A.

    2009-01-01

    The main field of electron-beam radiation processing applications is the modification of polymeric material. Polymer development includes new pathways to produce natural polymers with better mechanical and barrier properties and thermal stability. The aim of this paper was to investigate the behavior of a gelatin/acrylamide polymer treated by electron-beam radiation. Gelatin is a heterogeneous mixture of water-soluble proteins of high average molecular mass derived by hydrolytic action from animal collagen, a fibrous insoluble protein, which is widely found in nature as the major constituent of skin, bones and connective tissue. Hydrolyzed collagen is composed of a unique sequence of amino acids, characterized particularly by the high content of glycine, proline and hydroxyproline. Among biomaterials, gelatin is an interesting material because is a partially crystalline polymer and has a relatively low melting point. Samples of gelatin together with glycerin as plasticizer and acrylamide as copolymer were irradiated with doses of 10 kGy and 40 kGy, using an electron beam accelerator, dose rate 22.41kGy/s, at room temperature in presence of air. After irradiation, some preliminary analyses were done like viscometry, texture analyses and colorimetry. The results of the diverse tests showed changes that can be ascribed to radiation-induced crosslinking. The electron-beam processed acrylamide-gelatin polymer using glycerin as plasticizer must be first extensively characterized before to be used for general applications. (author)

  10. Dextran and gelatin based photocrosslinkable tissue adhesive.

    Science.gov (United States)

    Wang, Tao; Nie, Jun; Yang, Dongzhi

    2012-11-06

    A two-component tissue adhesive based on biocompatible and bio-degradable polymers (oxidized urethane dextran (Dex-U-AD) and gelatin) was prepared and photocrosslinked under the ultraviolet (UV) irradiation. The adhesive could adhere to surface of gelatin, which simulated the human tissue steadily. The structures of above Dex-U-AD were characterized by FTIR, (1)H NMR spectroscopy and XRD. The adhesion property of result products was evaluated by lap-shear test. The maximum adhesion strength could reach to 4.16±0.72 MPa which was significantly higher than that of fibrin glue. The photopolymerization process of Dex-U-AD/gelatin was monitored by real time infrared spectroscopy (RTIR). It took less than 5 min to complete the curing process. The cytotoxicity of Dex-U-AD/gelatin also was evaluated which indicated that Dex-U-AD/gelatin gels were nontoxic to L929 cell. The relationship between all the above-mentioned properties and degree of oxidization of Dex-U-AD was assessed. The obtained products have the potential to serve as tissue adhesive in the future. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Investigations on the Broadband Shielding Effectiveness of Metallized Glass Fiber

    National Research Council Canada - National Science Library

    Coburn, William

    1998-01-01

    ...) is an E-glass fiber metallized with Al and processed into a nonwoven mat. When formed into a mat, the MGFs lead to an effective sample conductivity, sigma eff, which is the parameter of interest for electromagnetic shielding in the RF region...

  12. Renewable Resources and a Recycled Polymer as Raw Materials: Mats from Electrospinning of Lignocellulosic Biomass and PET Solutions

    Directory of Open Access Journals (Sweden)

    Rachel Passos de Oliveira Santos

    2018-05-01

    Full Text Available Interest in the use of renewable raw materials in the preparation of materials has been growing uninterruptedly in recent decades. The aim of this strategy is to offer alternatives to the use of fossil fuel-based raw materials and to meet the demand for materials that are less detrimental to the environment after disposal. In this context, several studies have been carried out on the use of lignocellulosic biomass and its main components (cellulose, hemicelluloses, and lignin as raw materials for polymeric materials. Lignocellulosic fibers have a high content of cellulose, but there has been a notable lack of investigations on application of the electrospinning technique for solutions prepared from raw lignocellulosic biomass, even though the presence of cellulose favors the alignment of the fiber chains during electrospinning. In this investigation, ultrathin (submicrometric and nanoscale aligned fibers were successfully prepared via electrospinning (room temperature of solutions prepared with different contents of lignocellulosic sisal fibers combined with recycled poly(ethylene terephthalate (PET using trifluoroacetic acid (TFA as solvent. The “macro” fibers were deconstructed by the action of TFA, resulting in solutions containing their constituents, i.e., cellulose, hemicelluloses, and lignin, in addition to PET. The “macro” sisal fibers were reconstructed at the nanometer and submicrometric scale from these solutions. The SEM micrographs of the mats containing the components of sisal showed distinct fiber networks, likely due to differences in the solubility of these components in TFA and in their dielectric constants. The mechanical properties of the mats (dynamic mechanical analysis, DMA, and tensile properties were evaluated with the samples positioned both in the direction (dir of and in opposition (op to the alignment of the nano and ultrathin fibers, which can be considered a novelty in the analysis of this type of material

  13. Using Hydroxyapatite-Gelatin Scaffold Seeded with Bone Marrow Stromal Cells as a Bone Graft in Animal Model

    Directory of Open Access Journals (Sweden)

    Mahsoumeh Behruzi

    2016-11-01

    Full Text Available Background: Nowadays, composite scaffolds with some desired characteristics have a numerous applications in hard tissue engineering. In present study, the role of composite hydroxyapatite - gelatin was examined in both alone and coated by Bone Marrow Stromal Stem Cells (BMSCs conditions in the process of healing bone defects, reduction of time repair and the immune response of body by laboratory studies (in vitro and in vivo on the skull of adult rats as well. Materials and Methods: In present study, nano-hydroxyapatite powder and gelatin were used to provide nano-hydroxyapatite-gelatin scaffold, BMSCs were isolated by Flushing method. Fifteen adult male Wistar rats weighing 250-200 g were used. Studing groups included bone defect with hydroxyapatite-gelatin scaffold, bone defect with hydroxyapatite-gelatin with BMSCs and bone defects without scaffolding as a controlwhich were examined after a week and a month after surgery. MTT assay was used in order to evaluation of biocompatibility of scaffolds. To confirm the healing progress trend and the presence of inflammatory cells we used hematoxylin-eosin and we used Masson's trichrome staining in order to study of synthesis of collagen fibers. Results: The results of MTT showed that the scaffold has no toxic effects on stromal cells. The first signs of ossification in hydroxyapatite-gelatin with BMSCs cells group, appeared in the first week. However, in the fourth week, ossification was completed and the scaffold remaining was found as embedded islands in the spongy bone tissue. The greatest number of lymphocytes was observed in the experimental group after one week of planting scaffold. Conclusion: it seems that Hydroxyapatite-gelatin scaffold coated with BMSCs cells has a potential role in the healing process of bone and it can be suitable as a therapeutic strategy to repair extensive bone lesions.

  14. Influence of gelatinous fibers on the shrinkage of silver maple

    Science.gov (United States)

    Donals G. Arganbright; Dwight W. Bensend; Floyd G. Manwiller

    1970-01-01

    The degree of lean was found to have a significant influence on the logitudinal and transverse shrinkage of three soft maple trees. This may be accounted for by differences in the cell wall layer thickness and fibril angle.

  15. Ceramic fiber reinforced glass-ceramic matrix composite

    Science.gov (United States)

    Bansal, Narottam P. (Inventor)

    1993-01-01

    A slurry of BSAS glass powders is cast into tapes which are cut to predetermined sizes. Mats of continuous chemical vapor deposition (CVD)-SiC fibers are alternately stacked with these matrix tapes. This tape-mat stack is warm-pressed to produce a 'green' composite which is heated to burn out organic constituents. The remaining interim material is then hot-pressed to form a BSAS glass-ceramic fiber-reinforced composite.

  16. Recombinant gelatin and collagen from methylotrophic yeasts

    NARCIS (Netherlands)

    Bruin, de E.C.

    2002-01-01

    Based on its structural role and compatibility within the human body, collagen is a commonly used biomaterial in medical applications, such as cosmetic surgery, wound treatment and tissue engineering. Gelatin is in essence denatured and partly degraded collagen and is,

  17. Characterization of proteic content of gelatins

    Directory of Open Access Journals (Sweden)

    Eliane Bayle

    1995-03-01

    Otherwise, results obtained in Kjeldahl and Biuret methods are proportional. In fact, the authors suggest a limit proteic concentration expressed in mg BSA/g solid gelatin : 750 mg BSA /g corresponding to the standard decided by the Codex, 14 % nitrogen minimum.

  18. Electrospun bioactive mats enriched with Ca-polyphosphate/retinol nanospheres as potential wound dressing

    OpenAIRE

    Müller, Werner E.G.; Tolba, Emad; Dorweiler, Bernhard; Schröder, Heinz C.; Diehl-Seifert, Bärbel; Wang, Xiaohong

    2015-01-01

    Background While electrospun materials have been frequently used in tissue engineering no wound dressings exist that significantly improved wound healing effectively. Methods We succeeded to fabricate three-dimensional (3D) electrospun poly(D,l-lactide) (PLA) fiber mats into which nanospheres, formed from amorphous calcium polyphosphate (polyP) nanoparticles (NP) and encapsulated retinol (“retinol/aCa-polyP-NS” nanospheres [NS]), had been incorporated. Results Experiments with MC3T3-E1 cells ...

  19. Solubilization of bovine gelatin using power ultrasound: gelation without heating.

    Science.gov (United States)

    Farahnaky, Asgar; Zendeboodi, Fatemeh; Azizi, Rezvan; Mesbahi, Gholamreza; Majzoobi, Mahsa

    2017-04-01

    The aim of this study was to investigate the efficacy of power ultrasound without using any heating stage in solubilizeing gelatin dispersions, and to characterize the mechanical and microstructural properties of the resulting gels using texture analysis and scanning electron microscopy, respectively. Usually to prepare a gel from gelatin, a primary heating stage of at about 40C or above is required to solubilize gelatin macromolecules. In this study solubilizing gelatin dispersions using power ultrasound without any heating was successfully performed. For solubilising gelatin, an ultrasound equipment with a frequency of 20 kHz, amplitude of 100% and power range of 50-150 W was used. Aqueous gelatin dispersions (4% w/v) were subjected to ultrasound for different times (40-240 s) at a constant temperature of 13C. Applying ultrasound to gelatin dispersions caused increases in water absorption and water solubility of the hydrocolloid. The textural parameters of the resulting gelatin gels, increased with increasing time and power of ultrasound. Moreover, a generalized Maxwell model with three elements was used for calculating relaxation times of the gels. The microstructural observations by SEM showed that the structural cohesiveness of the gels increased by increasing ultrasonication time. Ultrasound-assisted solubilization of gelatin can have emerging implications for industrial uses in pharmaceuticals, food and non-food systems. Usually to prepare a gel from gelatin, a primary heating stage of at about 40C or above is required to solubilize gelatin macromolecules. Therefore, the use of gelatin as a hydrocolloid in food processings or pharmaceutical formulations which lack a heating step has been a technological and practical challenge. In this study solubilizing gelatin dispersions using power ultrasound without any heating was successfully performed. Ultrasound-assisted solubilisation of gelatin can have emerging implications for industrial uses in pharmaceuticals

  20. An investigation of electrospun Henna leaves extract-loaded chitosan based nanofibrous mats for skin tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Yousefi, Iman, E-mail: iman_yousefi@ut.ac.ir [School of Chemical Engineering, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Medical Biomaterials Research Center (MBRC), Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Pakravan, Mehdi [Department of Chemical Engineering, Ecole Polytechnique de Montreal, Montreal, Quebec (Canada); Rahimi, Hoda [Department of Pharmacognosy, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran (Iran, Islamic Republic of); Bahador, Abbas; Farshadzadeh, Zahra [Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Haririan, Ismael, E-mail: haririan@tums.ac.ir [Medical Biomaterials Research Center (MBRC), Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Department of Pharmaceutical Biomaterial, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Department of Pharmaceutics, School of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2017-06-01

    Wound healing characteristics of some plant extracts have been well known for many years, and they have been utilized for such applications in traditional way. Recently electrospun nanofibrous mats showed promising properties for tissue engineering and especially for skin repair. It is expected that incorporation of plant extracts into such structures could provide higher performance and synergistic effect for biomedical and wound healing applications. The final purpose of this study is to fabricate chitosan based nanofiber mats loaded with a traditional plant extract of Lawsonia inermis (Henna) leaves to enhance the antibacterial efficacy and wound healing of the precursor nanofibers. The morphology, structure, mechanical properties and swelling and weight loss degree of the electrospun nanofibers have been investigated in this study. Antibacterial activity, cell biocompatibility evaluations and in vivo wound healing activity of the abovementioned mats were also studied. The FESEM images of Henna leaves extract-loaded nanofibers proved that homogeneous, smooth and defect free nanofibers of 64–87 nm in diameter have been prepared. Presence of Henna extract in the electrospun fibers was approved by Fourier Transform Infrared spectroscopy. Incorporation of Henna extract into the nanofiber mats exhibited significant synergistic antibacterial activity against bacterial cells. It was well supported by the results of cell viability and proliferation of human foreskin fibroblast cells on the prepared scaffolds. Therefore, the results of this work showed that Henna leaves extract incorporated chitosan nonwoven mats have a great potential to be used as the biodegradable, biobased and antibacterial wound healing dressings. - Highlights: • Henna leaves extract were successfully loaded into chitosan based nanofiber mats. • These mats demonstrated significant synergistic antibacterial activity. • Combined properties of chitosan nanofibers and Henna promoted cell

  1. An investigation of electrospun Henna leaves extract-loaded chitosan based nanofibrous mats for skin tissue engineering

    International Nuclear Information System (INIS)

    Yousefi, Iman; Pakravan, Mehdi; Rahimi, Hoda; Bahador, Abbas; Farshadzadeh, Zahra; Haririan, Ismael

    2017-01-01

    Wound healing characteristics of some plant extracts have been well known for many years, and they have been utilized for such applications in traditional way. Recently electrospun nanofibrous mats showed promising properties for tissue engineering and especially for skin repair. It is expected that incorporation of plant extracts into such structures could provide higher performance and synergistic effect for biomedical and wound healing applications. The final purpose of this study is to fabricate chitosan based nanofiber mats loaded with a traditional plant extract of Lawsonia inermis (Henna) leaves to enhance the antibacterial efficacy and wound healing of the precursor nanofibers. The morphology, structure, mechanical properties and swelling and weight loss degree of the electrospun nanofibers have been investigated in this study. Antibacterial activity, cell biocompatibility evaluations and in vivo wound healing activity of the abovementioned mats were also studied. The FESEM images of Henna leaves extract-loaded nanofibers proved that homogeneous, smooth and defect free nanofibers of 64–87 nm in diameter have been prepared. Presence of Henna extract in the electrospun fibers was approved by Fourier Transform Infrared spectroscopy. Incorporation of Henna extract into the nanofiber mats exhibited significant synergistic antibacterial activity against bacterial cells. It was well supported by the results of cell viability and proliferation of human foreskin fibroblast cells on the prepared scaffolds. Therefore, the results of this work showed that Henna leaves extract incorporated chitosan nonwoven mats have a great potential to be used as the biodegradable, biobased and antibacterial wound healing dressings. - Highlights: • Henna leaves extract were successfully loaded into chitosan based nanofiber mats. • These mats demonstrated significant synergistic antibacterial activity. • Combined properties of chitosan nanofibers and Henna promoted cell

  2. Electrospun gelatin biopapers as substrate for in vitro bilayer models of blood-brain barrier tissue.

    Science.gov (United States)

    Bischel, Lauren L; Coneski, Peter N; Lundin, Jeffrey G; Wu, Peter K; Giller, Carl B; Wynne, James; Ringeisen, Brad R; Pirlo, Russell K

    2016-04-01

    Gaining a greater understanding of the blood-brain barrier (BBB) is critical for improvement in drug delivery, understanding pathologies that compromise the BBB, and developing therapies to protect the BBB. In vitro human tissue models are valuable tools for studying these issues. The standard in vitro BBB models use commercially available cell culture inserts to generate bilayer co-cultures of astrocytes and endothelial cells (EC). Electrospinning can be used to produce customized cell culture substrates with optimized material composition and mechanical properties with advantages over off-the-shelf materials. Electrospun gelatin is an ideal cell culture substrate because it is a natural polymer that can aid cell attachment and be modified and degraded by cells. Here, we have developed a method to produce cell culture inserts with electrospun gelatin "biopaper" membranes. The electrospun fiber diameter and cross-linking method were optimized for the growth of primary human endothelial cell and primary human astrocyte bilayer co-cultures to model human BBB tissue. BBB co-cultures on biopaper were characterized via cell morphology, trans-endothelial electrical resistance (TEER), and permeability to FITC-labeled dextran and compared to BBB co-cultures on standard cell culture inserts. Over longer culture periods (up to 21 days), cultures on the optimized electrospun gelatin biopapers were found to have improved TEER, decreased permeability, and permitted a smaller separation between co-cultured cells when compared to standard PET inserts. © 2016 Wiley Periodicals, Inc.

  3. Investigation of needleless electrospun PAN nanofiber mats

    Science.gov (United States)

    Sabantina, Lilia; Mirasol, José Rodríguez; Cordero, Tomás; Finsterbusch, Karin; Ehrmann, Andrea

    2018-04-01

    Polyacrylonitrile (PAN) can be spun from a nontoxic solvent (DMSO, dimethyl sulfoxide) and is nevertheless waterproof, opposite to the biopolymers which are spinnable from aqueous solutions. This makes PAN an interesting material for electrospinning nanofiber mats which can be used for diverse biotechnological or medical applications, such as filters, cell growth, wound healing or tissue engineering. On the other hand, PAN is a typical base material for producing carbon nanofibers. Nevertheless, electrospinning PAN necessitates convenient spinning parameters to create nanofibers without too many membranes or agglomerations. Thus we have studied the influence of spinning parameters on the needleless electrospinning process of PAN dissolved in DMSO and the resulting nanofiber mats.

  4. Biosynthesis and Characterization of Nanocellulose-Gelatin Films

    Directory of Open Access Journals (Sweden)

    Muenduen Phisalaphong

    2013-02-01

    Full Text Available A nanocellulose-gelatin (bacterial cellulose gelatin (BCG film was developed by a supplement of gelatin, at a concentration of 1%–10% w/v, in a coconut-water medium under the static cultivation of Acetobacter xylinum. The two polymers exhibited a certain degree of miscibility. The BCG film displayed dense and uniform homogeneous structures. The Fourier transform infrared spectroscopy (FTIR results demonstrated interactions between the cellulose and gelatin. Incorporation of gelatin into a cellulose nanofiber network resulted in significantly improved optical transparency and water absorption capacity of the films. A significant drop in the mechanical strengths and a decrease in the porosity of the film were observed when the supplement of gelatin was more than 3% (w/v. The BCG films showed no cytotoxicity against Vero cells.

  5. The decontamination effects of gamma irradiation on the edible gelatin

    International Nuclear Information System (INIS)

    Fu, Junjie; Shen, Weiqiao; Bao, Jinsong; Chen, Qinglong

    2000-01-01

    The decontamination effects of gamma irradiation on the edible gelatin were studied. The results indicated that the bacterium and mold in the gelatin decreased significantly with the dose of 5 kGy treatment. However, the content of crude protein, microelement, amino acid in the gelatin remained unchanged under the irradiation of 4 and 8 kGy. The viscosity of the gelatin decreased with the increase of the irradiation dose, but the gelatin with a dose of 5 kGy treatment still accorded with the standard of the second-order class. These results suggested that the optimum irradiation dose for edible gelatin for the purpose of decontamination was in the range 3-5 kGy. (author)

  6. Creating 3D gelatin phantoms for experimental evaluation in biomedicine

    Directory of Open Access Journals (Sweden)

    Stein Nils

    2015-09-01

    Full Text Available We describe and evaluate a setup to create gelatin phantoms by robotic 3D printing. Key aspects are the large workspace, reproducibility and resolution of the created phantoms. Given its soft tissue nature, the gelatin is kept fluid during inside the system and we present parameters for additive printing of homogeneous, solid objects. The results indicate that 3D printing of gelatin can be an alternative for quickly creating larger soft tissue phantoms without the need for casting a mold.

  7. Gelatin behaviour in dilute aqueous solution : designing a nanoparticulate formulation

    OpenAIRE

    Farrugia, Claude; Groves, Michael J.

    1999-01-01

    Although it has been claimed that nanoparticles can be produced from gelatin, a naturally occurring polypeptide, the commercial conversion of animal collagen to gelatin results in a heterogeneous product with a wide molecular-weight range. This is probably responsible for the widely observed variation in the experimental conditions required for nanoparticle formation. In this study, 0.2% w/v aqueous B225 gelatin solutions were incubated under various conditions of time, temperature, pH an...

  8. Extraction and characterisation of gelatin from the skin of striped ...

    African Journals Online (AJOL)

    Functional properties of gelatin from skin of striped catfish with and without bleaching for 48 h by 5% H2O2 (w/v)) were studied. Gelatin from skin bleached with 5% H2O2 for 48 h showed the highest yield (16.18 g). Bleaching not only improved the colour of gelatin gel by increasing the L* (lightness)-value and decreasing ...

  9. Electrospun Gelatin/poly(Glycerol Sebacate Membrane with Controlled Release of Antibiotics for Wound Dressing

    Directory of Open Access Journals (Sweden)

    Parisa Shirazaki

    2017-01-01

    Full Text Available Background: The most important risk that threatens the skin wounds is infections. Therefore, fabrication of a membrane as a wound dressing with the ability of antibiotic delivery in a proper delivery rate is especially important. Materials and Methods: Poly(glycerol sebacate (PGS was prepared from sebacic acid and glycerol with 1:1 ratio; then, it was added to gelatin in the 1:3 ratio and was dissolved in 80% (v/v acetic acid, and finally, ciprofloxacin was added in 10% (w/v of polymer solution. The gelatin/PGS membrane was fabricated using an electrospinning method. The membrane was cross-linked using ethyl-3-(3-dimethylaminopropyl carbodiimide ethyl-3-(3-dimethylaminopropylcarbodiim (EDC and N-hydroxysuccinimide (NHS in different time periods to achieve a proper drug release rate. Fourier-transform infrared (FTIR spectroscopy was being used to manifest the peaks of polymers and drug in the membrane. Scanning electron microscopy (SEM was used to evaluate the morphology, fibers diameter, pore size, and porosity before and after crosslinking process. Ultraviolet (UV-visible spectrophotometry was used to show the ciprofloxacin release from the cross-linked membrane. Results: FTIR analysis showed the characteristic peaks of gelatin, PGS, and ciprofloxacin without any added peaks after the crosslinking process. SEM images revealed that nanofibers' size increased during the crosslinking process and porosity was higher than 80% before and after crosslinking process. UV-visible spectrophotometry showed the proper rate of ciprofloxacin release occurred from cross-linked membrane that remaining in EDC/NHS ethanol solution for 120 min. Conclusion: The obtained results suggest that this recently developed gelatin/PGS membrane with controlled release of ciprofloxacin could be a promising biodegradable membrane for wound dressing.

  10. Cavitation nucleation in gelatin: Experiment and mechanism.

    Science.gov (United States)

    Kang, Wonmo; Adnan, Ashfaq; O'Shaughnessy, Thomas; Bagchi, Amit

    2018-02-01

    Dynamic cavitation in soft materials is becoming increasingly relevant due to emerging medical implications such as the potential of cavitation-induced brain injury or cavitation created by therapeutic medical devices. However, the current understanding of dynamic cavitation in soft materials is still very limited, mainly due to lack of robust experimental techniques. To experimentally characterize cavitation nucleation under dynamic loading, we utilize a recently developed experimental instrument, the integrated drop tower system. This technique allows quantitative measurements of the critical acceleration (a cr ) that corresponds to cavitation nucleation while concurrently visualizing time evolution of cavitation. Our experimental results reveal that a cr increases with increasing concentration of gelatin in pure water. Interestingly, we have observed the distinctive transition from a sharp increase (pure water to 1% gelatin) to a much slower rate of increase (∼10× slower) between 1% and 7.5% gelatin. Theoretical cavitation criterion predicts the general trend of increasing a cr , but fails to explain the transition rates. As a likely mechanism, we consider concentration-dependent material properties and non-spherical cavitation nucleation sites, represented by pre-existing bubbles in gels, due to possible interplay between gelatin molecules and nucleation sites. This analysis shows that cavitation nucleation is very sensitive to the initial configuration of a bubble, i.e., a non-spherical bubble can significantly increase a cr . This conclusion matches well with the experimentally observed liquid-to-gel transition in the critical acceleration for cavitation nucleation. From a medical standpoint, understanding dynamic cavitation within soft materials, i.e., tissues, is important as there are both potential injury implications (blast-induced cavitation within the brain) as well as treatments utilizing the phenomena (lithotripsy). In this regard, the main

  11. Comparison of ballistic impact effects between biological tissue and gelatin.

    Science.gov (United States)

    Jin, Yongxi; Mai, Ruimin; Wu, Cheng; Han, Ruiguo; Li, Bingcang

    2018-02-01

    Gelatin is commonly used in ballistic testing as substitute for biological tissue. Comparison of ballistic impact effects produced in the gelatin and living tissue is lacking. The work in this paper was aimed to compare the typical ballistic impact effects (penetration trajectory, energy transfer, temporary cavity) caused by 4.8mm steel ball penetrating the 60kg porcine hind limbs and 10wt% gelatin. The impact event in the biological tissue was recorded by high speed flash X-ray machine at different delay time, while the event in the gelatin continuously recorded by high speed video was compared to that in the biological tissue. The collected results clearly displayed that the ballistic impact effects in the muscle and gelatin were similar for the steel ball test; as for instance, the projectile trajectory in the two targets was basically similar, the process of energy transfer was highly coincident, and the expansion of temporary cavity followed the same pattern. This study fully demonstrated that choosing gelatin as muscle simulant was reasonable. However, the maximum temporary cavity diameter in the gelatin was a little larger than that in the muscle, and the expansion period of temporary cavity was longer in the gelatin. Additionally, the temporary cavity collapse process in the two targets followed different patterns, and the collapse period in the gelatin was two times as long as that in the muscle. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Effect of dose rate on radical and property of gelatin

    International Nuclear Information System (INIS)

    Geng Shengrong; Chen Yuxia; Zu Xiaoyan; Li Xin; Jiang Hongyou

    2015-01-01

    The gelatin was irradiated respectively in the range of 0-32 kGy by dose rates of 60 Gy/min 60 Co, 480 Gy/min 60 Co and 12000 Gy/min accelerator, and the relationships of the radical character and gelatin property with dose rate were investigated through electron spin resonance (ESR) and gelatin permeation chromatogram. The results show that there is weak ESR signal from unirradiated gelatin, but irradiated one presents typical double peak. The order of ESR signal intensity of gelatin with the same absorbed dosage from high to low is 60 Gy/min 60 Co, 480 Gy/min 60 Co and 12000 Gy/min accelerator. The linear relationship between ESR signal intensity from 60 Co irradiated gelatin and absorbed dose is y= 26.983x 2 +1 641.8x-205.69. The intrinsic viscosity, average relative molecular weight, gelatin strength and breaking elongation of irradiated gelatin from high to low are 480 Gy/min 60 Co, 12000 Gy/min accelerator and 60 Gy/min 60 Co. The protection mechanism of high dose rate radiation on gelatin degradation is that the production of effective long life free radicals reduces. (authors)

  13. Instrumental texture profile analysis of gelatin gel extracted from grouper skin and commercial (bovine and porcine) gelatin gels.

    Science.gov (United States)

    Rahman, Mohammad Shafiur; Al-Mahrouqi, Abdullah Issa

    2009-01-01

    Mechanical compression was used to study the gelling characteristics of gelatin gels. Texture profile analysis (TPA) showed that the hardness of fish and mammalian gelatin increased significantly as the concentrations of gels increased. TPA attributes of 10% fish skin gel showed significant differences from those obtained from 20% and 30% gels. In bovine and porcine cases, such generic trends were not observed. Mechanical characteristics of 10% gels of gelatin from fish skin, determined from one cycle compression, were significantly lower than other sources of gelatin gels, while bovine and porcine gels did not show any significant differences. In the case of TPA, hardness of bovine gelatin gel was highest at 41 N for 10% gel, followed by porcine (30 N) then fish skin (5 N) gelatin gels. The gels prepared from different sources did not show any generic trends when all other mechanical attributes were considered.

  14. HiRadMat: materials under scrutiny

    CERN Multimedia

    Anaïs Schaeffer

    2011-01-01

    CERN's new facility, HiRadMat (High Radiation to Materials), which is designed to test materials for the world's future particle accelerators, should be operational and welcoming its first experiments by the end of the year.   The HiRadMat facility, located in the TNC tunnel. The materials used in the LHC and its experiments are exposed to very high-energy particles. The LHC machine experts obviously didn't wait for the first collisions in the world's most powerful accelerator to put the materials through their paces - the equipment was validated following a series of stringent tests. And these tests will get even tougher now, with the arrival of HiRadMat. The tunnel that formerly housed the West Area Neutrino Facility (WANF) has been completely revamped to make way for CERN's latest facility, HiRadMat. Supported by the Radioprotection service, a team from the Engineering (EN) Department handled the dismantling operations from October 2009 to December 2010. "We could only work on disman...

  15. Bilayer porous scaffold based on poly-(ε-caprolactone) nanofibrous membrane and gelatin sponge for favoring cell proliferation

    International Nuclear Information System (INIS)

    Zhou Zhihua; Zhou Yang; Chen Yiwang; Nie Huarong; Wang Yang; Li Fan; Zheng Yan

    2011-01-01

    Electrospun poly-(ε-caprolactone) (PCL) nanofibers has been widely used in the medical prosthesis. However, poor hydrophilicity and the lack of natural recognition sites for covalent cell-recognition signal molecules to promote cell attachment have limited its utility as tissue scaffolds. In this study, Bilayer porous scaffolds based on PCL electrospun membranes and gelatin (GE) sponges were fabricated through soft hydrolysis of PCL electrospun followed by grafting gelatin onto the fiber surface, through crosslinking and freeze drying treatment of additional gelatin coat and grafted gelatin surface. GE sponges were stably anchored on PCL membrane surface with the aid of grafted GE molecules. The morphologies of bilayer porous scaffolds were observed through SEM. The contact angle of the scaffolds was 0°, the mechanical properties of scaffolds were measured by tensile test, Young's moduli of PCL scaffolds before and after hydrolysis are 66-77.3 MPa and 62.3-75.4 MPa, respectively. Thus, the bilayer porous scaffolds showed excellent hydrophilic surface and desirable mechanical strength due to the soft hydrolysis and GE coat. The cell culture results showed that the adipose derived mesenchymal stem cells did more favor to adhere and grow on the bilayer porous scaffolds than on PCL electrospun membranes. The better cell affinity of the final bilayer scaffolds not only attributed to the surface chemistry but also the introduction of bilayer porous structure.

  16. Bilayer porous scaffold based on poly-({epsilon}-caprolactone) nanofibrous membrane and gelatin sponge for favoring cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Zhihua; Zhou Yang [Department of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China); Chen Yiwang, E-mail: ywchen@ncu.edu.cn [Department of Chemistry, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China); Institute of Polymers, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China); Nie Huarong, E-mail: niehr@iccas.ac.cn [Institute of Polymers, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China); Wang Yang [First Affiliated Hospital, Nanchang University, 17 Yongwaizheng Road, Nanchang 330006 (China); Li Fan; Zheng Yan [Institute of Polymers, Nanchang University, 999 Xuefu Avenue, Nanchang 330031 (China)

    2011-12-15

    Electrospun poly-({epsilon}-caprolactone) (PCL) nanofibers has been widely used in the medical prosthesis. However, poor hydrophilicity and the lack of natural recognition sites for covalent cell-recognition signal molecules to promote cell attachment have limited its utility as tissue scaffolds. In this study, Bilayer porous scaffolds based on PCL electrospun membranes and gelatin (GE) sponges were fabricated through soft hydrolysis of PCL electrospun followed by grafting gelatin onto the fiber surface, through crosslinking and freeze drying treatment of additional gelatin coat and grafted gelatin surface. GE sponges were stably anchored on PCL membrane surface with the aid of grafted GE molecules. The morphologies of bilayer porous scaffolds were observed through SEM. The contact angle of the scaffolds was 0 Degree-Sign , the mechanical properties of scaffolds were measured by tensile test, Young's moduli of PCL scaffolds before and after hydrolysis are 66-77.3 MPa and 62.3-75.4 MPa, respectively. Thus, the bilayer porous scaffolds showed excellent hydrophilic surface and desirable mechanical strength due to the soft hydrolysis and GE coat. The cell culture results showed that the adipose derived mesenchymal stem cells did more favor to adhere and grow on the bilayer porous scaffolds than on PCL electrospun membranes. The better cell affinity of the final bilayer scaffolds not only attributed to the surface chemistry but also the introduction of bilayer porous structure.

  17. Poly-m-aramid nanofiber mats: Production for application as structural modifiers in CFRP laminates

    Science.gov (United States)

    Mazzocchetti, Laura; D'Angelo, Emanuele; Benelli, Tiziana; Belcari, Juri; Brugo, Tommaso Maria; Zucchelli, Andrea; Giorgini, Loris

    2016-05-01

    Poly(m-phenylene isophtalamide) electrospun nanofibrous membranes were produced to be used as structural reinforcements for carbon fiber reinforced composites production. In order for the polymer to be electrospun, it needs however to be fully solubilized, so the addition of some salts is required to help disrupt the tight macromolecular packing based on intra- and inter-molecular hydrogen bonding. Such salts may also contribute to the electrospinnability of the overall solution, since the provide it with a higher conductivity, whatever the solvent might be. The salt haobwever stays in the final nanofibrous mat. The membranes containing the salt are also observed to be highly hygroscopic, with a water content up to 26%, in the presence of 20%wt LiCl in the nanofibrous mat. When those membranes were interleaved among prepregs to produce a laminates, the obtained composite displayed thermal properties comparable to those of a reference nanofiber-free composite, though the former showed also easier delamination. Hence the removal of the hygroscopic salt was performed, that lead to thinner membranes, whose water content matched that of the pristine polymer. The washing step induced a thinning of the layers and of the fibers diameters, though no fiber shrinking nor membrane macroscopic damages were observed. These preliminary encouraging results thus pave the way to a deeper study of the optimized condition for producing convenient poly(m-phenylene isophtalamide) electrospun nanofibrous membranes to be used for carbon fiber reinforced composites structural modification.

  18. Molecular beacon-based real-time PCR method for detection of porcine DNA in gelatin and gelatin capsules.

    Science.gov (United States)

    Mohamad, Nurhidayatul Asma; Mustafa, Shuhaimi; Khairil Mokhtar, Nur Fadhilah; El Sheikha, Aly Farag

    2018-03-05

    The pharmaceutical industry has boosted gelatin consumption worldwide. This is supported by the availability of cost-effective gelatin production from porcine by-products. However, cross-contamination of gelatin materials, where porcine gelatin was unintentionally included in the other animal sources of gelatin, has caused significant concerns about halal authenticity. The real-time polymerase chain reaction (PCR) has enabled a highly specific and sensitive animal species detection method in various food products. Hence, such a technique was employed in the present study to detect and quantify porcine DNA in gelatin using a molecular beacon probe, with differences in performance between mitochondrial (cytochrome b gene) and chromosomal DNA-(MPRE42 repetitive element) based porcine-specific PCR assays being compared. A higher sensitivity was observed in chromosomal DNA (MPRE-PCR assay), where this assay allows the detection of gelatin DNA at amounts as as low as 1 pg, whereas mitochondrial DNA (CBH-PCR assay) can only detect at levels down to 10 pg of gelatin DNA. When an analysis with commercial gelatin and gelatin capsule samples was conducted, the same result was observed, with a significantly more sensitive detection being provided by the repetitive element of chromosomal DNA. The present study has established highly sensitive DNA-based porcine detection systems derived from chromosomal DNA that are feasible for highly processed products such as gelatin and gelatin capsules containing a minute amount of DNA. This sensitive detection method can also be implemented to assist the halal authentication process of various food products available on the market. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

  19. Thermodynamics and phase transformations the selected works of Mats Hillert

    CERN Document Server

    Lilensten, Jean

    2006-01-01

    This book is a compendium of Mat Hillert's publications. Mat Hillert is a world specialist in metal alloy at the origin of a universal computing code used to calculate the diagrams of phase. This work is in English.

  20. Biocidal Activity of Plasma Modified Electrospun Polysulfone Mats Functionalized with Polyethyleneimine-Capped Silver Nanoparticles

    KAUST Repository

    Schiffman, Jessica D.

    2011-11-01

    The incorporation of silver nanoparticles (AgNPs) into polymeric nanofibers has attracted a great deal of attention due to the strong antimicrobial activity that the resulting fibers exhibit. However, bactericidal efficacy of AgNP-coated electrospun fibrous mats has not yet been demonstrated. In this study, polysulfone (PSf) fibers were electrospun and surface-modified using an oxygen plasma treatment, which allowed for facile irreversible deposition of cationically charged polyethyleneimine (PEI)-AgNPs via electrostatic interactions. The PSf-AgNP mats were characterized for relative silver concentration as a function of plasma treatment time using ICP-MS and changes in contact angle. Plasma treatment of 60 s was the shortest time required for maximum loss of bacteria (Escherichia coli) viability. Time-dependent bacterial cytotoxicity studies indicate that the optimized PSf-AgNP mats exhibit a high level of inactivation against both Gram negative bacteria, Escherichia coli, and Gram positive bacteria, Bacillus anthracis and Staphylococcus aureus. © 2011 American Chemical Society.

  1. Contributions of Ectomycorrhizal Fungal Mats to Forest Soil Carbon Cycles

    Science.gov (United States)

    Kluber, L. A.; Phillips, C. L.; Myrold, D. D.; Bond, B. J.

    2008-12-01

    Ectomycorrhizal (EM) fungi are a prominent and ubiquitous feature of forest soils, forming symbioses with most tree species, yet little is known about the magnitude of their impact on forest carbon cycles. A subset of EM fungi form dense, perennial aggregations of hyphae, which have elevated respiration rates compared with neighboring non-mat soils. These mats are a foci of EM activity and thereby a natural laboratory for examining how EM fungi impact forest soils. In order to constrain the contributions of EM fungi to forest soil respiration, we quantified the proportion of respiration derived from EM mat soils in an old-growth Douglas-fir stand in western Oregon. One dominant genus of mat-forming fungi, Piloderma, covered 56% of the soil surface area. Piloderma mats were monitored for respiration rates over 15 months and found to have on average 10% higher respiration than non-mat soil. At the stand level, this amounts to roughly 6% of soil respiration due to the presence of Piloderma mats. We calculate that these mats may constitute 27% of autotrophic respiration, based on respiration rates from trenched plots in a neighboring forest stand. Furthermore, enzyme activity and microbial community profiles in mat and non-mat soil provide evidence that specialized communities utilizing chitin contribute to this increased efflux. With 60% higher chitinase activity in mats, the breakdown of chitin is likely an important carbon flux while providing carbon and nitrogen to the microbial communities associated with mats. Quantitative PCR showed similar populations of fungi and bacteria in mat and non-mat soils; however, community analysis revealed distinct fungal and bacterial communities in the two soil types. The higher respiration associated with EM mats does not appear to be due only to a proliferation of EM fungi, but to a shift in overall community composition to organisms that efficiently utilize the unique resources available within the mat, including plant and

  2. Siwonhan-mat: The third taste of Korean foods

    Directory of Open Access Journals (Sweden)

    Soon Ah Kang

    2016-03-01

    Conclusion: Siwonhan-mat is a unique sensation found in Korean food. Understanding siwonhan-mat is a key to learning about Korean food and its food culture. Therefore, this paper serves an important role in understanding Korean food. Siwonhan-mat is often mistranslated using words to describe temperature, such as cool. This misinterpretation has resulted in confusion over the original meaning of siwonhan-mat and contributed to the incorrect usage of the word.

  3. Electrospun gelatin/poly(ε-caprolactone) fibrous scaffold modified with calcium phosphate for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Rajzer, Izabella, E-mail: irajzer@ath.bielsko.pl [University of Bielsko-Biala (ATH), Department of Mechanical Engineering Fundamentals, Division of Materials Engineering, Willowa 2 Street, 43-309 Bielsko-Biała (Poland); Menaszek, Elżbieta [Jagiellonian University (UJ), Collegium Medicum, Department of Cytobiology, Medyczna 9 Street, 30-068 Cracow (Poland); Kwiatkowski, Ryszard [University of Bielsko-Biala (ATH), Faculty of Materials and Environmental Sciences, Institute of Textile Engineering and Polymer Materials, Willowa 2 Street, 43-309 Bielsko-Biała (Poland); Planell, Josep A.; Castano, Oscar [Institute for Bioengineering of Catalonia (IBEC), Biomaterials for Regenerative Therapies, Baldiri Reixac 15-21, 08028 Barcelona (Spain); Polytechnic University of Catalonia (UPC), Diagonal 647, 08028 Barcelona (Spain); CIBER-BBN The Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine, Barcelona (Spain)

    2014-11-01

    In this study gelatin (Gel) modified with calcium phosphate nanoparticles (SG5) and polycaprolactone (PCL) were used to prepare a 3D bi-layer scaffold by collecting electrospun PCL and gelatin/SG5 fibers separately in the same collector. The objective of this study was to combine the desired properties of PCL and Gel/SG5 in the same scaffold in order to enhance mineralization, thus improving the ability of the scaffold to bond to the bone tissue. The scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and the wide angle X-ray diffraction (WAXD) measurements confirmed that SG5 nanoparticles were successfully incorporated into the fibrous gelatin matrix. The composite Gel/SG5/PCL scaffold exhibited more enhanced mechanical properties than individual Gel and Gel/SG5 scaffolds. The presence of SG5 nanoparticles accelerated the nucleation and growth of apatite crystals on the surface of the composite Gel/SG5/PCL scaffold in simulated body fluid (SBF). The osteoblast response in vitro to developed electrospun scaffolds (PCL and Gel/SG5/PCL) was investigated by using normal human primary NHOst cell lines. NHOst cell culture studies showed that higher alkaline phosphatase (ALP) activity and better mineralization were obtained in the case of composite materials than in pure PCL scaffolds. The mechanically strong PCL scaffold served as a skeleton, while the Gel/SG5 fibers facilitated cell spreading and mineralization of the scaffold. - Highlights: • Bi-layer scaffolds were produced by electrospinning method. • The addition of nanoparticles enhanced the bioactivity of scaffold. • Bi-layer scaffold enhanced ALP activity and NHOst cell mineralization.

  4. Does siwonhan-mat represent delicious in Korean foods?

    Directory of Open Access Journals (Sweden)

    Dai Ja Jang

    2016-06-01

    Conclusion: Balancing kan is a determining factor of siwonhan-mat in Korean cuisine. Particularly, a strong association between siwonhan-mat and deliciousness was found in kuk and tang, suggesting the importance of siwonhan-mat in experiencing the best flavor in Korean food.

  5. Developing DNA barcoding (matK) primers for marama bean ...

    African Journals Online (AJOL)

    The homology found with Tylosema fassoglensis (trnK gene) and Pisum sativum (matK gene) suggests that an identical region was amplified for Tylosema esculentum. A phylogenetic tree was constructed based on the matK sequences and the results suggest that the matK region can also be used in determining levels of ...

  6. Disruption of photoautotrophic intertidal mats by filamentous fungi

    DEFF Research Database (Denmark)

    Carreira, Cátia; Staal, Marc Jaap; Falkoski, Daniel

    2015-01-01

    Summary: Ring-like structures, 2.0-4.8cm in diameter, observed in photosynthetic microbial mats on the Wadden Sea island Schiermonnikoog (the Netherlands) showed to be the result of the fungus Emericellopsis sp. degrading the photoautotrophic top layer of the mat. The mats were predominantly comp...

  7. Incorporation of mesoporous silica nanoparticles into random electrospun PLGA and PLGA/gelatin nanofibrous scaffolds enhances mechanical and cell proliferation properties

    DEFF Research Database (Denmark)

    Mehrasa, Mohammad; Asadollahi, Mohammad Ali; Nasri-Nasrabadi, Bijan

    2016-01-01

    Poly(lactic-co-glycolic.acid) (PLGA) and PLGA/gelatin random nanofibrous scaffolds embedded with different amounts of mesoporous silica nanoparticles (MSNPs) were fabricated using electrospinning method. To evaluate the effects of nanoparticles on the scaffolds, physical, chemical, and mechanical...... the porosity of scaffolds. Nanoparticles also improved the tensile mechanical properties of scaffolds. Using in vitro degradation analysis, it was shown that the addition of nanoparticles to the nano fibers matrix increases the weight loss percentage of PLGA-based samples, whereas it decreases the weight loss...... properties as well as in vitro degradation behavior of scaffolds were investigated. The mean diameters of nanofibers were 974 ± 68 nm for the pure PLGA scaffolds vs 832 ± 70, 764 ± 80, and 486 ± 64 for the PLGA/gelatin, PLGA/10 wt% MSNPs, and the PLGA/gelatin/10 wt% MSNPs scaffolds, respectively. The results...

  8. Assessment of Matrix Metalloproteinases by Gelatin Zymography.

    Science.gov (United States)

    Cathcart, Jillian

    2016-01-01

    Matrix metalloproteinases are endopeptidases responsible for remodeling of the extracellular matrix and have been identified as critical contributors to breast cancer progression. Gelatin zymography is a valuable tool which allows the analysis of MMP expression. In this approach, enzymes are resolved electrophoretically on a sodium dodecyl sulfate-polyacrylamide gel copolymerized with the substrate for the MMP of interest. Post electrophoresis, the enzymes are refolded in order for proteolysis of the incorporated substrate to occur. This assay yields valuable information about MMP isoforms or changes in activation and can be used to analyze the role of MMPs in normal versus pathological conditions.

  9. Electrospun Fibers for Composites Applications

    Science.gov (United States)

    2014-02-01

    in traditional woven mat composites. Nanofibrous interlayers were used to increase the impact and shear performance of a prepregged carbon fiber...Nylon 66 Nanofibrilmat Interleaved Carbon/Epoxy Laminates . Polymer Composites 2011, 32, 1781–1789. 21 13. Chen, Q.; Zhang, L.; Rahman, A.; Zhou...Resistance in Laminated Composites With Electrospun Nano-Interlayers. Comp. Sci. Tech. 2008, 68, 673– 683. 15. Zhang, J.; Lin, T.; Wang, X. Electrospun

  10. Dehydration of pollock skin prior to gelatin production

    Science.gov (United States)

    Alaska pollock (Theragra chalcogramma) is the U.S.A.'s largest commercial fishery, with an annual catch of over 1 million tons. During pollock processing, the skins are discarded or made into fish meal, despite their value for gelatin production. The absence of gelatin-processing facilities in Alask...

  11. Extraction and characterisation of gelatin from the skin of striped ...

    African Journals Online (AJOL)

    Prabjeet Singh

    2017-01-04

    Jan 4, 2017 ... squid skin in 1% H2O2 in 0.01 M NaOH for 48 h could improve the ... of fish skin gelatin. Gelatin was extracted from washed giant catfish skin as described ..... bleached, because the flesh could be stained by ink, viscera and ...

  12. Gelatin Nanoparticles with Enhanced Affinity for Calcium Phosphate

    NARCIS (Netherlands)

    Farbod, K.; Diba, M.; Zinkevich, T.; Schmidt, S.; Harrington, M.J.; Kentgens, A.P.; Leeuwenburgh, S.C.

    2016-01-01

    Gelatin nanoparticles can be tuned with respect to their drug loading efficiency, degradation rate, and release kinetics, which renders these drug carriers highly suitable for a wide variety of biomedical applications. The ease of functionalization has rendered gelatin an interesting candidate

  13. Modification of gelatin functionality for culinary applications by using transglutaminase

    DEFF Research Database (Denmark)

    Calvarro, Julia; Pérez-Palacios, Trinidad; Ruiz Carrascal, Jorge

    2016-01-01

    TGase turned rapidly into liquid in less than 10 min at 80 °C. Hardness and chewiness of the gels were strongly enhanced by gelatin content, but very especially by TGase concentration. Gels tended to be less springy with increasing amounts of TGase. Modification of gelatin-based foams and gels...

  14. Bioprinted chitosan-gelatin thermosensitive hydrogels using an inexpensive 3D printer.

    Science.gov (United States)

    Roehm, Kevin D; Madihally, Sundararajan V

    2017-11-30

    The primary bottleneck in bioprinting cell-laden structures with carefully controlled spatial relation is a lack of biocompatible inks and printing conditions. In this regard, we explored using thermogelling chitosan-gelatin (CG) hydrogel as a novel bioprinting ink; CG hydrogels are unique in that it undergoes a spontaneous phase change at physiological temperature, and does not need post-processing. In addition, we used a low cost (printer, and modified with a new extruder to print using disposable syringes and hypodermic needles. We investigated (i) the effect of concentration of CG on gelation characteristics, (ii) solution preparation steps (centrifugation, mixing, and degassing) on printability and fiber formation, (iii) the print bed temperature profiles via IR imaging and grid-based assessment using thermocouples, (iv) the effect of feed rate (10-480 cm min -1 ), flow rate (15-60 μl min -1 ) and needle height (70-280 μm) on fiber size and characteristics, and (v) the distribution of neuroblastoma cells in printed fibers, and the viability after five days in culture. We used agarose gel to create uniform print surfaces to maintain a constant gap with the needle tip. These results showed that degassing the solution, and precooling the solution was necessary for obtaining continuous fibers. Fiber size decreased from 760, to 243 μm as the feed rate increased from 10 to 100 cm min -1 . Bed temperature played the greatest role in fiber size, followed by feed rate. Increased needle height initially decreased fiber size but then increased showing an optimum. Cells were well distributed within the fibers and exhibited excellent viability and no contamination after 5 d. Overall we printed 3D, sterile, cell-laden structures with an inexpensive bioprinter and a novel ink, without post-processing. The bioprinter described here and the novel CG hydrogels have significant potential as an ink for bioprinitng various cell-laden structures.

  15. Gelatin Functionalization of Biomaterial Surfaces: Strategies for Immobilization and Visualization

    Directory of Open Access Journals (Sweden)

    Peter Dubruel

    2011-01-01

    Full Text Available In the present work, the immobilization of gelatin as biopolymer on two types of implantable biomaterials, polyimide and titanium, was compared. Both materials are known for their biocompatibility while lacking cell-interactive behavior. For both materials, a pre-functionalization step was required to enable gelatin immobilization. For the polyimide foils, a reactive succinimidyl ester was introduced first on the surface, followed by covalent grafting of gelatin. For the titanium material, methacrylate groups were first introduced on the Ti surface through a silanization reaction. The applied functionalities enabled the subsequent immobilization of methacrylamide modified gelatin. Both surface modified materials were characterized in depth using atomic force microscopy, static contact angle measurements, confocal fluorescence microscopy, attenuated total reflection infrared spectroscopy and X-ray photo-electron spectroscopy. The results indicated that the strategies elaborated for both material classes are suitable to apply stable gelatin coatings. Interestingly, depending on the material class studied, not all surface analysis techniques are applicable.

  16. Mekh-mat entrance examinations problems

    CERN Document Server

    Vardi, I

    2000-01-01

    This paper provides a complete solution set to 25 ``killer problems'' given to Jewish candidates to the Mekh--mat at Moscow State University during the 1970's and 1980's. Typically, the problems are at the mathematical olympiad level and some feature interesting theorems. However, a number of the problems are flawed, or even completely wrong. The paper therefore includes an evaluation of the problems in the style of a referee report.

  17. Chemical engineering and thermodynamics using Mat lab

    International Nuclear Information System (INIS)

    Kim Heon; Kim, Moon Gap; Lee, Hak Yeong; Yeo, Yeong Gu; Ham, Seong Won

    2002-02-01

    This book consists of twelve chapters and four appendixes about chemical engineering and thermodynamics using Mat lab, which deals with introduction, energy budget, entropy, thermodynamics process, generalization on any fluid, engineering equation of state for PVT properties, deviation of the function, phase equilibrium of pure fluid, basic of multicomponent, phase equilibrium of compound by state equation, activity model and reaction system. The appendixes is about summary of computer program, related mathematical formula and material property of pure component.

  18. Effects of feeding ratio of beet pulp to alfalfa hay or grass hay on ruminal mat characteristics and chewing activity in Holstein dry cows.

    Science.gov (United States)

    Izumi, Kenichi; Unno, Chigusa

    2010-04-01

    The influence of the feeding ratio of a non-forage fiber source and hay on ruminal mat characteristics and chewing activity was evaluated in dairy dry cows. Cows were fed four different diets: the ratios of alfalfa hay (AH) to beet pulp (BP) were 8:2 (dry matter basis, A8B2) and 2:8 (A2B8), and those of grass hay (GH) to BP were 8:2 (G8B2) and 2:8 (G2B8). Total eating time was decreased with increasing BP content (P rumination time for AH was shorter than that for GH (P content (P ruminal mat was detected by using a penetration resistance test of the rumen digesta. Penetration resistance value (PRV) of ruminal mat was highest with the G8B2 diet and PRV decreased with increasing BP content (P ruminal mat was greater for increasing BP content (P ruminal mat PRV on total rumination time resulted in a high positive correlation (r = 0.744; P ruminal mat stimulated rumination activity and a ruminal mat could be formed, although it was soft even when cows were offered a large quantity of BP.

  19. Co-electrospun gelatin-poly(L-lactic acid) scaffolds: Modulation of mechanical properties and chondrocyte response as a function of composition

    Energy Technology Data Exchange (ETDEWEB)

    Torricelli, Paola [Preclinical and Surgical Studies Laboratory, Codivilla Putti Research Institute, Rizzoli Orthopaedic Institute, via di Barbiano, 1/10, 40136 Bologna (Italy); Laboratory of Biocompatibility, Innovative Technologies and Advanced Therapies—Department Rizzoli Research, Innovation, Technology, via di Barbiano, 1/10, 40136 Bologna (Italy); Gioffrè, Michela; Fiorani, Andrea; Panzavolta, Silvia [Department of Chemistry “G. Ciamician” and National Consortium of Materials Science and Technology (INSTM, Bologna RU), University of Bologna (Italy); Gualandi, Chiara [Department of Chemistry “G. Ciamician” and National Consortium of Materials Science and Technology (INSTM, Bologna RU), University of Bologna (Italy); Advanced Mechanics and Materials—Interdepartmental Center for Industrial Research (AMM ICIR), University of Bologna (Italy); Fini, Milena [Preclinical and Surgical Studies Laboratory, Codivilla Putti Research Institute, Rizzoli Orthopaedic Institute, via di Barbiano, 1/10, 40136 Bologna (Italy); Laboratory of Biocompatibility, Innovative Technologies and Advanced Therapies—Department Rizzoli Research, Innovation, Technology, via di Barbiano, 1/10, 40136 Bologna (Italy); Focarete, Maria Letizia, E-mail: marialetizia.focarete@unibo.it [Department of Chemistry “G. Ciamician” and National Consortium of Materials Science and Technology (INSTM, Bologna RU), University of Bologna (Italy); Health Sciences and Technologies—Interdepartmental Center for Industrial Research (HST-ICIR) (Italy); Bigi, Adriana [Department of Chemistry “G. Ciamician” and National Consortium of Materials Science and Technology (INSTM, Bologna RU), University of Bologna (Italy)

    2014-03-01

    Bio-synthetic scaffolds of interspersed poly(L-lactic acid) (PLLA) and gelatin (GEL) fibers are fabricated by co-electrospinning. Tailored PLLA/GEL compositions are obtained and GEL crosslinking with genipin provides for the maintenance of good fiber morphology. Scaffold tensile mechanical properties are intermediate between those of pure PLLA and GEL and vary as a function of PLLA content. Primary human chondrocytes grown on the scaffolds exhibit good proliferation and increased values of the differentiation parameters, especially for intermediate PLLA/GEL compositions. Mineralization tests enable the deposition of a uniform layer of poorly crystalline apatite onto the scaffolds, suggesting potential applications involving cartilage as well as cartilage–bone interface tissue engineering. - Highlights: • Bio-synthetic scaffolds of PLLA and gelatin are produced by co-electrospinning. • Scaffolds with tailored PLLA–gelatin composition are fabricated. • PLLA/gelatin ratio controls scaffold mechanical properties and mineralization. • Chondrocyte proliferation and differentiation are modulated. • Scaffolds are suitable for cartilage–bone interface tissue engineering.

  20. Effect of Saponification Condition on the Morphology and Diameter of the Electrospun Poly(vinyl acetate) Nanofibers for the Fabrication of Poly(vinyl alcohol) Nanofiber Mats

    OpenAIRE

    Seong Baek Yang; Jong Won Kim; Jeong Hyun Yeum

    2016-01-01

    Novel poly(vinyl alcohol) (PVA) nanofiber mats were prepared for the first time through heterogeneous saponification of electrospun poly(vinyl acetate) (PVAc) nanofibers. The effect of varying the saponification conditions, including temperature, time, and concentration of the alkaline solution, on the morphology of the saponified PVA fibers were evaluated by field-emission scanning electron microscopy. At 25 °C, the saponified PVA fibers exhibited a broad diameter distribution. The average f...

  1. Synthesis and Property of Ag(NP)/catechin/Gelatin Nanofiber

    Science.gov (United States)

    Nasir, Muhamad; Apriani, Dita

    2017-12-01

    Nanomaterial play important role future industry such as for the medical, food, pharmaceutical and cosmetic industry. Ag (NP) and catechin exhibit antibacterial property. Ag(NP) with diameter around 15 nm was synthesis by microwaved method. We have successfully produce Ag(NP)/catechin/gelatin nanofiber composite by electrospinning process. Ag(NP)/catechin/gelatin nanofiber was synthesized by using gelatin from tuna fish, polyethylene oxide (PEO), acetic acid as solvent and silver nanoparticle(NP)/catechin as bioactive component, respectively. Morphology and structure of bioactive catechin-gelatin nanofiber were characterized by scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FTIR), respectively. SEM analysis showed that morphology of nanofiber composite was smooth and had average diameter 398.97 nm. FTIR analysis results were used to confirm structure of catechin-gelatin nanofiber. It was confirmed by FTIR that specific vibration band peak amide A (N-H) at 3286,209 cm-1, amide B (N-H) 3069,396 cm-1, amide I (C=O) at 1643,813 cm-1, amide II (N-H and CN) at 1538,949 cm-1, amide III (C-N) at 1276,789 cm-1, C-O-C from polyethylene oxide at 1146,418 cm-1, respectively. When examined to S. Aureus bacteria, Ag/catechin/gelatin nanofiber show inhabitation performance around 40.44%. Ag(NP)/catechin/gelatin nanofiber has potential application antibacterial medical application.

  2. Wet method for measuring starch gelatinization temperature using electrical conductivity.

    Science.gov (United States)

    Morales-Sanchez, E; Figueroa, J D C; Gaytan-Martínez, M

    2009-09-01

    The objective of the present study was to develop a method for obtaining the gelatinization temperature of starches by using electrical conductivity. Native starches from corn, rice, potato, and wheat were prepared with different proportions of water and heated from room temperature to 90 degrees C, in a device especially designed for monitoring the electrical conductivity as a function of temperature. The results showed a linear trend of the electrical conductivity with the temperature until it reaches the onset gelatinization temperature. After that point, the electrical conductivity presented an increment or decrement depending on the water content in the sample and it was related to starch swelling and gelatinization phenomena. At the end gelatinization temperature, the conductivity becomes stable and linear, indicating that there are no more changes of phase. The starch gelatinization parameter, which was evaluated in the 4 types of starches using the electrical conductivity, was compared with those obtained by using differential scanning calorimeter (DSC). The onset temperature at which the electrical conductivity increased or decreased was found to be similar to that obtained by DSC. Also, the final temperature at which the electrical conductivity returned to linearity matched the end gelatinization temperature of the DSC. Further, a wet method for measuring the onset, peak, and end gelatinization temperatures as a function of temperature using the electrical conductivity curves is presented for a starch-water suspension.

  3. Tunable engineered skin mechanics via coaxial electrospun fiber core diameter.

    Science.gov (United States)

    Blackstone, Britani Nicole; Drexler, Jason William; Powell, Heather Megan

    2014-10-01

    Autologous engineered skin (ES) offers promise as a treatment for massive full thickness burns. Unfortunately, ES is orders of magnitude weaker than normal human skin causing it to be difficult to apply surgically and subject to damage by mechanical shear in the early phases of engraftment. In addition, no manufacturing strategy has been developed to tune ES biomechanics to approximate the native biomechanics at different anatomic locations. To enhance and tune ES biomechanics, a coaxial (CoA) electrospun scaffold platform was developed from polycaprolactone (PCL, core) and gelatin (shell). The ability of the coaxial fiber core diameter to control both scaffold and tissue mechanics was investigated along with the ability of the gelatin shell to facilitate cell adhesion and skin development compared to pure gelatin, pure PCL, and a gelatin-PCL blended fiber scaffold. CoA ES exhibited increased cellular adhesion and metabolism versus PCL alone or gelatin-PCL blend and promoted the development of well stratified skin with a dense dermal layer and a differentiated epidermal layer. Biomechanics of the scaffold and ES scaled linearly with core diameter suggesting that this scaffold platform could be utilized to tailor ES mechanics for their intended grafting site and reduce graft damage in vitro and in vivo.

  4. Tunable Engineered Skin Mechanics via Coaxial Electrospun Fiber Core Diameter

    Science.gov (United States)

    Blackstone, Britani Nicole; Drexler, Jason William

    2014-01-01

    Autologous engineered skin (ES) offers promise as a treatment for massive full thickness burns. Unfortunately, ES is orders of magnitude weaker than normal human skin causing it to be difficult to apply surgically and subject to damage by mechanical shear in the early phases of engraftment. In addition, no manufacturing strategy has been developed to tune ES biomechanics to approximate the native biomechanics at different anatomic locations. To enhance and tune ES biomechanics, a coaxial (CoA) electrospun scaffold platform was developed from polycaprolactone (PCL, core) and gelatin (shell). The ability of the coaxial fiber core diameter to control both scaffold and tissue mechanics was investigated along with the ability of the gelatin shell to facilitate cell adhesion and skin development compared to pure gelatin, pure PCL, and a gelatin-PCL blended fiber scaffold. CoA ES exhibited increased cellular adhesion and metabolism versus PCL alone or gelatin-PCL blend and promoted the development of well stratified skin with a dense dermal layer and a differentiated epidermal layer. Biomechanics of the scaffold and ES scaled linearly with core diameter suggesting that this scaffold platform could be utilized to tailor ES mechanics for their intended grafting site and reduce graft damage in vitro and in vivo. PMID:24712409

  5. Laser cleaning of 19th century Congo rattan mats

    International Nuclear Information System (INIS)

    Carmona, N.; Oujja, M.; Roemich, H.; Castillejo, M.

    2011-01-01

    There is a growing interest by art conservators for laser cleaning of organic materials, such as wooden artworks, paper and textiles, since traditional cleaning with solvents can be a source of further decay and mechanical cleaning may be too abrasive for sensitive fibers. In this work we present a successful laser cleaning approach for 19th century rattan mats from the Brooklyn Museum collection of African Art, now part of the study collection at the Conservation Center in New York. Tests were carried out using the fundamental (1064 nm) and second harmonic (532 nm) wavelength of a Q-switched Nd:YAG laser to measure threshold values both for surface damage and color changes for different types of rattan samples. The irradiated substrates were investigated by optical microscopy, scanning electron microscopy and by UV-vis spectroscopy in order to determine the efficiency of laser cleaning and to assess possible deterioration effects that may have occurred as a result of laser irradiation. The study showed that by using the laser emission at 532 nm, a wavelength for which photon energy is below the bond dissociation level of the main cellulosic compounds and the water absorption is negligible, it is possible to select a range of laser fluences to remove the black dust layer without damaging the rattan material.

  6. Influence of lyophilization factors and gelatin concentration on pore structures of atelocollagen/gelatin sponge biomaterial.

    Science.gov (United States)

    Yang, Longqiang; Tanabe, Koji; Miura, Tadashi; Yoshinari, Masao; Takemoto, Shinji; Shintani, Seikou; Kasahara, Masataka

    2017-07-26

    This study aimed to investigate influences of lyophilization factors and gelatin concentration on pore structures of ACG sponge. ACG sponges of different freezing temperatures (-30, -80 and -196 o C), freezing times (1, 2 and 24 h), gelatin concentrations (0.6%AC+0.15%G, 0.6%AC+0.6%G and 0.6%AC+2.4%G), and with 500 μM fluvastatin were fabricated. Pore structures including porosity and pore size were analyzed by scanning electron microscopy and ImageJ. The cytotoxic effects of ACG sponges were evaluated in vitro. Freezing temperature did not affect porosity while high freezing temperature (-30 o C) increased pore size. The high gelatin concentration group (0.6%AC+2.4%G) had decreased porosity and pore size. Freezing time and 500 μM fluvastatin did not affect pore structures. The cytotoxicity and cell proliferation assays revealed that ACG sponges had no cytotoxic effects on human mesenchymal stromal cell growth and proliferation. These results indicate that ACG sponge may be a good biomaterial scaffold for bone regeneration.

  7. The characterisation of a genipin-gelatin gel dosimeter

    International Nuclear Information System (INIS)

    Davies, J B; Bosi, S; Baldock, C

    2010-01-01

    Genipin cross links gelatin to slowly form a blue colour that bleaches upon irradiation. Spectrophotometric measurements of the absorbance change following irradiation to doses up to 100 Gy gives a linear dose response for certain concentrations of the gel ingredients; genipin, gelatin and sulphuric acid. Dose sensitivity increases with increasing concentrations of sulphuric acid and genipin and is also strongly dependent on the time allowed for the genipin-gelatin cross linking reaction (referred to here as blending) to take place. The optimum formulation of this gel was found for genipin concentration between 0.3 - 0.5 mM and blending time of at least 4 h.

  8. Production of 131I gelatin capsules

    International Nuclear Information System (INIS)

    Freud, A.; Hirshfeld, N.; Canfi, A.; Melamud, Y.

    1997-01-01

    Radioiodine ( 131 I) hard-gelatin capsules are widely used for the diagnosis and treatment of various thyroid disorders. Until 1980 radioiodine was supplied by us as a liquid dosage. This proved to be a rather inconvenient form since it resulted in inaccurate dosing by the physicians and caused frequent contamination of the patients and the hospital personnel. In an attempt to overcome these problems we have designed and constructed a production facility for capsules in which 1311 is packaged. Because of the extreme precautions necessary in handling radioactive compounds, encapsulation of radioactive materials requires specifically designed production techniques, special instrumentation and unique quality control procedures that are not encountered in the standard capsule production processes in the pharmaceutical industry

  9. Gelation on heating of supercooled gelatin solutions.

    Science.gov (United States)

    Guigo, Nathanaël; Sbirrazzuoli, Nicolas; Vyazovkin, Sergey

    2012-04-23

    Diluted (1.0-1.5 wt%) aqueous gelatin solutions have been cooled to -10 °C at a cooling rate 20 °C min(-1) without freezing and detectable gelation. When heated at a constant heating rate (0.5 -2 °C min(-1)), the obtained supercooled solutions demonstrate an atypical process of gelation that has been characterized by regular and stochastically modulated differential scanning calorimetry (DSC) as well as by isoconversional kinetic analysis. The process is detectable as an exothermic peak in the total heat flow of regular DSC and in the nonreversing heat flow of stochastically modulated DSC. Isoconversional kinetic analysis applied to DSC data reveals that the effective activation energy of the process increases from approximately 75 to 200 kJ mol(-1) as a supercooled solution transforms to gel on continuous heating. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Protein gradient films of fibroin and gelatine.

    Science.gov (United States)

    Claussen, Kai U; Lintz, Eileen S; Giesa, Reiner; Schmidt, Hans-Werner; Scheibel, Thomas

    2013-10-01

    Gradients are a natural design principle in biological systems that are used to diminish stress concentration where materials of differing mechanical properties connect. An interesting example of a natural gradient material is byssus, which anchors mussels to rocks and other hard substrata. Building upon previous work with synthetic polymers and inspired by byssal threads, protein gradient films are cast using glycerine-plasticized gelatine and fibroin exhibiting a highly reproducible and smooth mechanical gradient, which encompasses a large range of modulus from 160 to 550 MPa. The reproducible production of biocompatible gradient films represents a first step towards medical applications. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Charpy V, an application in Mat lab

    International Nuclear Information System (INIS)

    Castillo M, J.A.; Torres V, M.

    2003-01-01

    The obtained results with the system Charpy V V 1 designed in Mat lab for the estimate of parameters of three mathematical models are shown. The adjustment of data is used to determine the fracture energy, the lateral expansion and the percentage of ductility of steels coming from the reactor vessels of Laguna Verde, Veracruz. The data come from test tubes type Charpy V of irradiated material and not irradiated. To verify our results they were compared with those obtained by General Electric of data coming from the Laguna Verde nuclear power plant. (Author)

  12. How compressible is recombinant battery separator mat?

    Energy Technology Data Exchange (ETDEWEB)

    Pendry, C. [Hollingsworth and Vose, Postlip Mills Winchcombe (United Kingdom)

    1999-03-01

    In the past few years, the recombinant battery separator mat (RBSM) for valve-regulated lead/acid (VRLA) batteries has become the focus of much attention. Compression, and the ability of microglass separators to maintain a level of `springiness` have helped reduce premature capacity loss. As higher compressions are reached, we need to determine what, if any, damage can be caused during the assembly process. This paper reviews the findings when RBSM materials, with different surface areas, are compressed under forces up to 500 kPa in the dry state. (orig.)

  13. Contributions of ectomycorrhizal fungal mats to forest soil respiration

    Science.gov (United States)

    C. Phillips; L.A. Kluber; J.P. Martin; B.A. Caldwell; B.J. Bond

    2012-01-01

    Distinct aggregations of fungal hyphae and rhizomorphs, or “mats”, formed by some genera of ectomycorrhizal (EcM) fungi are common features of soils in coniferous forests of the Pacific Northwest. We measured in situ respiration rates of Piloderma mats and neighboring non-mat soils in an old-growth Douglas-fir forest in western Oregon to investigate whether there was...

  14. In vitro and in vivo evaluation of electrospun nanofibers of PCL, chitosan and gelatin: A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, S.R., E-mail: srrg@campus.fct.unl.pt [Centro de Física e Investigação Tecnológica/Departamento de Física Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Rodrigues, G. [Centro de Biologia Ambiental/Departamento de Biologia Animal Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa (Portugal); Martins, G.G. [Centro de Biologia Ambiental/Departamento de Biologia Animal Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa (Portugal); Instituto Gulbenkian de Ciência, R. da Quinta Grande, 6, 2780-156 Oeiras (Portugal); Roberto, M.A. [Departamento de Cirurgia Plástica e Reconstrutiva e Unidade de Queimados, Hospital de São José, Rua José António Serrano, 1150-199 Lisboa (Portugal); Mafra, M. [Serviço de Anatomia Patológica, Hospital de São José, Rua José António Serrano, 1150-199 Lisboa (Portugal); Henriques, C.M.R. [Centro de Física e Investigação Tecnológica/Departamento de Física Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); and others

    2015-01-01

    Many polymers have been investigated with respect to their use in skin tissue engineering. However, directly comparable data on the role played by different polymers in assisting skin wound healing requires their in vitro and in vivo evaluation under the same conditions. Therefore, we performed a study in order to compare the performance of electrospun nanofiber mats from three different polymers concerning cell–scaffold interaction and wound healing promotion. A polyester (polycaprolactone, PCL), a protein (gelatin from cold water fish skin, GEL) and a polysaccharide (chitosan, CS) were the polymers chosen. Gelatin nanofibers were crosslinked with glutaraldehyde vapor. The scaffolds were characterized physico-chemically, in vitro by seeding with human fetal fibroblasts, HFFF2, and used in vivo as skin substitutes in a rat wound model with total skin removal. In vitro tests revealed that cells adhered and proliferated in all scaffolds. However, cells deep into the scaffold were only observed in the PCL and CS scaffolds. In in vivo tests CS scaffolds had the highest impact on the healing process by decreasing the extent of wound contraction and enhancing the production of a neodermis and re-epithelialization of the wound. - Highlights: • We produced and compared the properties of electrospun PCL, CS and fish GEL. • In vitro, cells adhered and proliferated better on GEL scaffolds. • Deep cell migration was observed in the PCL and CS matrices. • In vivo, both CS and GEL matrices integrated well within the wounds. • Only CS effectively blocked, although only partially, the contraction phenomenon.

  15. In vitro and in vivo evaluation of electrospun nanofibers of PCL, chitosan and gelatin: A comparative study

    International Nuclear Information System (INIS)

    Gomes, S.R.; Rodrigues, G.; Martins, G.G.; Roberto, M.A.; Mafra, M.; Henriques, C.M.R.

    2015-01-01

    Many polymers have been investigated with respect to their use in skin tissue engineering. However, directly comparable data on the role played by different polymers in assisting skin wound healing requires their in vitro and in vivo evaluation under the same conditions. Therefore, we performed a study in order to compare the performance of electrospun nanofiber mats from three different polymers concerning cell–scaffold interaction and wound healing promotion. A polyester (polycaprolactone, PCL), a protein (gelatin from cold water fish skin, GEL) and a polysaccharide (chitosan, CS) were the polymers chosen. Gelatin nanofibers were crosslinked with glutaraldehyde vapor. The scaffolds were characterized physico-chemically, in vitro by seeding with human fetal fibroblasts, HFFF2, and used in vivo as skin substitutes in a rat wound model with total skin removal. In vitro tests revealed that cells adhered and proliferated in all scaffolds. However, cells deep into the scaffold were only observed in the PCL and CS scaffolds. In in vivo tests CS scaffolds had the highest impact on the healing process by decreasing the extent of wound contraction and enhancing the production of a neodermis and re-epithelialization of the wound. - Highlights: • We produced and compared the properties of electrospun PCL, CS and fish GEL. • In vitro, cells adhered and proliferated better on GEL scaffolds. • Deep cell migration was observed in the PCL and CS matrices. • In vivo, both CS and GEL matrices integrated well within the wounds. • Only CS effectively blocked, although only partially, the contraction phenomenon

  16. Institute for Non-Lethal Defense Technologies Report: Ballistic Gelatin

    National Research Council Canada - National Science Library

    Nicholas, N. C; Welsch, J. R

    2004-01-01

    Ballistic gelatin is designed to simulate living soft tissue. It is the standard for evaluating the effectiveness of firearms against humans because of its convenience and acceptability over animal or cadaver testing...

  17. Starvation marrow – gelatinous transformation of bone marrow

    Directory of Open Access Journals (Sweden)

    Eric Osgood

    2014-09-01

    Full Text Available Gelatinous bone marrow transformation (GMT, also known as starvation marrow, represents a rare pathological entity of unclear etiology, in which bone marrow histopathology demonstrates hypoplasia, fat atrophy, and gelatinous infiltration. The finding of gelatinous marrow transformation lacks disease specificity; rather, it is an indicator of severe illness and a marker of poor nutritional status, found in patients with eating disorders, acute febrile illnesses, acquired immunodeficiency syndrome, alcoholism, malignancies, and congestive heart failure. We present a middle-aged woman with a history of alcoholism, depression, and anorexia nervosa who presented with failure to thrive and macrocytic anemia, with bone marrow examination demonstrative of gelatinous transformation, all of which resolved with appropriate treatment. To our knowledge, there are very few cases of GMT which have been successfully treated; thus, our case highlights the importance of proper supportive management.

  18. Physical and Mechanical Properties of Jute Mat Reinforced Epoxy Composites

    Directory of Open Access Journals (Sweden)

    S.M Sadaf

    2011-11-01

    Full Text Available Cellulose jute fibre offers a number of benefits as reinforcement for synthetic polymers since it has a high specific strength and stiffness, low hardness, relatively low density and biodegradability. To reduce moisture uptake and hence to improve the mechanical properties of the composites, bleached jute mats were incorporated as reinforcing elements in the epoxy matrix. Composites at varying volume fractions and different orientations of jute mat were fabricated by hot compression machine under specific pressures and temperatures. Tensile, flexure, impact and water absorption tests of composites were conducted. Jute mat oriented at (0 ± 45–90° composites showed reduced strength compared to (0–90° fibre mat composites. Impact strength and water uptake of high volume fraction jute mat reinforced composites was higher compared to that of lower volume fraction composites. Fracture surfaces of jute mat composites were analyzed under SEM. Fracture surface of (0–90° jute mat oriented composites showed twisted fibres, while (0 ± 45–90° jute mat oriented composites had fibre pull-out without any twisting. Overall, composites containing 52% jute mat at orientations of (0–90° showed better properties compared to other fabricated composites.

  19. Hydrophilic PCU scaffolds prepared by grafting PEGMA and immobilizing gelatin to enhance cell adhesion and proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Changcan; Yuan, Wenjie; Khan, Musammir; Li, Qian [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Feng, Yakai, E-mail: yakaifeng@tju.edu.cn [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Key Laboratory of Systems Bioengineering of Ministry of Education, Tianjin University, Tianjin 300072 (China); Tianjin University-Helmholtz-Zentrum Geesthacht, Joint Laboratory for Biomaterials and Regenerative Medicine, Tianjin 300072 (China); Collaborative Innovation Center of Chemical Science and Chemical Engineering (Tianjin) Tianjin 300072 (China); Yao, Fanglian [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Key Laboratory of Systems Bioengineering of Ministry of Education, Tianjin University, Tianjin 300072 (China); Tianjin University-Helmholtz-Zentrum Geesthacht, Joint Laboratory for Biomaterials and Regenerative Medicine, Tianjin 300072 (China); Zhang, Wencheng, E-mail: wenchengzhang@yahoo.com [Department of Physiology and Pathophysiology, Logistics University of Chinese People' s Armed Police Force, Tianjin 300162 (China)

    2015-05-01

    Gelatin contains many functional motifs which can modulate cell specific adhesion, so we modified polycarbonate urethane (PCU) scaffold surface by immobilization of gelatin. PCU-g-gelatin scaffolds were prepared by direct immobilizing gelatins onto the surface of aminated PCU scaffolds. To increase the immobilization amount of gelatin, poly(ethylene glycol) methacrylate (PEGMA) was grafted onto PCU scaffolds by surface initiated atom transfer radical polymerization. Then, following amination and immobilization, PCU-g-PEGMA-g-gelatin scaffolds were obtained. Both modified scaffolds were characterized by chemical and biological methods. After immobilization of gelatin, the microfiber surface became rough, but the original morphology of scaffolds was maintained successfully. PCU-g-PEGMA-g-gelatin scaffolds were more hydrophilic than PCU-g-gelatin scaffolds. Because hydrophilic PEGMA and gelatin were grafted and immobilized onto the surface, the PCU-g-PEGMA-g-gelatin scaffolds showed low platelet adhesion, perfect anti-hemolytic activity and excellent cell growth and proliferation capacity. It could be envisioned that PCU-g-PEGMA-g-gelatin scaffolds might have potential applications in tissue engineering artificial scaffolds. - Graphical abstract: PCU-g-gelatin scaffolds were prepared by direct immobilizing gelatin onto the surface of aminated PCU scaffolds (method a). To increase the immobilization amount of gelatin, PEGMAs were grafted onto the scaffold surface by SI-ATRP. PCU-g-PEGMA-g-gelatin scaffolds were prepared by method b. The gelatin modified scaffolds exhibited high hydrophilicity, low platelet adhesion, perfect anti-hemolytic activity, and excellent cell adhesion and proliferation capacity. They might have potential applications as tissue engineering scaffolds for artificial blood vessels. - Highlights: • Hydrophilic scaffolds were prepared by grafting PEGMA and immobilization of gelatins. • Grafting PEGMA enhanced the immobilization amount of gelatin

  20. The edible gelatin irradiation sterilization technology and quality control

    International Nuclear Information System (INIS)

    Fu Junjie; Shi Jianjun; Shen Weiqiao

    2000-01-01

    60 Co γ-ray irradiation sterilization technology was used in treating edible gelatin and the irradiation effects on viscosity, protein and amino acid were studied. The results demonstrated that the irradiation dose had negative correlation with viscosity, and there were no damage effects on the gelatin with 360 days storage under room temperature. According to D 10 Value, the suitable irradiation dose should be 3-5 kGy

  1. Investigations on the Chemical Degradation of Silver Gelatine Prints

    OpenAIRE

    Maha Ahmed ALI; Mona Fouad ALI; Mohammed Osama SAKER; Abdel Azez El Bayoumi ABDEL ALEEM; Khaled Ibrahim EL NAGAR

    2012-01-01

    Photographs are considered composite objects with complex chemical and physical structures. Therefore they are more prone to damage as compared to other objects. Chemical degradation is by far the most common decay form found among photographic collections. This study investigates the chemical degradation of silver gelatin prints (DOP) and the reaction of the image, silver, gelatin, and paper to accelerated aging, to the action of light, and oxidizing gases, in terms of their physical and che...

  2. Micropatterned coculture of vascular endothelial and smooth muscle cells on layered electrospun fibrous mats toward blood vessel engineering.

    Science.gov (United States)

    Li, Huinan; Liu, Yaowen; Lu, Jinfu; Wei, Jiaojun; Li, Xiaohong

    2015-06-01

    A major challenge in vascular engineering is the establishment of proper microenvironment to guide the spatial organization, growth, and extracellular matrix (ECM) productions of cells found in blood vessels. In the current study, micropatterned fibrous mats with distinct ridges and grooves of different width were created to load smooth muscle cells (SMCs), which were assembled by stacking on vascular endothelial cell (EC)-loaded flat fibrous mats to mimic the in vivo-like organized structure of blood vessels. SMCs were mainly distributed in the ridges, and aligned fibers in the patterned regions led to the formation of elongated cell bodies, intense actin filaments, and expressions of collagen I and α-smooth muscle actin in a parallel direction with fibers. ECs spread over the flat fibrous mats and expressed collagen IV and laminin with a cobblestone-like feature. A z-stack scanning of fluorescently stained fibrous mats indicated that SMCs effectively infiltrated into fibrous scaffolds at the depth of around 200 μm. Compared with SMCs cultured alone, the coculture with ECs enhanced the proliferation, infiltration, and cytoskeleton elongation of SMCs on patterned fibrous mats. Although the coculture of SMCs made no significant difference in the EC growth, the coculture system on patterned fibrous scaffolds promoted ECM productions of both ECs and SMCs. Thus, this patterned fibrous configuration not only offers a promising technology in the design of tissue engineering scaffolds to construct blood vessels with durable mechanical properties, but also provides a platform for patterned coculture to investigate cell-matrix and cell-cell interactions in highly organized tissues. © 2014 Wiley Periodicals, Inc.

  3. Ultrafine polybenzimidazole (PBI) fibers. [separators for alkaline batteries and dfuel cells

    Science.gov (United States)

    Chenevey, E. C.

    1979-01-01

    Mats were made from ultrafine polybenzimidazole (PBI) fibers to provide an alternate to the use of asbestos as separators in fuel cells and alkaline batteries. To minimize distortion during mat drying, a process to provide a dry fibrid was developed. Two fibrid types were developed: one coarse, making mats for battery separators; the other fine, making low permeability matrices for fuel cells. Eventually, it was demonstrated that suitable mat fabrication techniques yielded fuel cell separators from the coarser alkaline battery fibrids. The stability of PBI mats to 45% KOH at 123 C can be increased by heat treatment at high temperatures. Weight loss data to 1000 hours exposure show the alkali resistance of the mats to be superior to that of asbestos.

  4. Viscoelastic shock wave in ballistic gelatin behind soft body armor.

    Science.gov (United States)

    Liu, Li; Fan, Yurun; Li, Wei

    2014-06-01

    Ballistic gelatins are widely used as a surrogate of biological tissue in blunt trauma tests. Non-penetration impact tests of handgun bullets on the 10wt% ballistic gelatin block behind soft armor were carried out in which a high-speed camera recorded the crater׳s movement and pressure sensors imbedded in the gelatin block recorded the pressure waves at different locations. The observed shock wave attenuation indicates the necessity of considering the gelatin׳s viscoelasticity. A three-element viscoelastic constitutive model was adopted, in which the relevant parameters were obtained via fitting the damping free oscillations at the beginning of the creep-mode of rheological measurement, and by examining the data of published split Hopkinson pressure bar (SHPB) experiments. The viscoelastic model is determined by a retardation time of 5.5×10(-5)s for high oscillation frequencies and a stress relaxation time of 2.0-4.5×10(-7)s for shock wave attenuation. Using the characteristic-line method and the spherical wave assumption, the propagation of impact pressure wave front and the subsequent unloading profile can be simulated using the experimental velocity boundary condition. The established viscoelastic model considerably improves the prediction of shock wave attenuation in the ballistic gelatin. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Gelatin-Based Hydrogels for Organ 3D Bioprinting

    Directory of Open Access Journals (Sweden)

    Xiaohong Wang

    2017-08-01

    Full Text Available Three-dimensional (3D bioprinting is a family of enabling technologies that can be used to manufacture human organs with predefined hierarchical structures, material constituents and physiological functions. The main objective of these technologies is to produce high-throughput and/or customized organ substitutes (or bioartificial organs with heterogeneous cell types or stem cells along with other biomaterials that are able to repair, replace or restore the defect/failure counterparts. Gelatin-based hydrogels, such as gelatin/fibrinogen, gelatin/hyaluronan and gelatin/alginate/fibrinogen, have unique features in organ 3D bioprinting technologies. This article is an overview of the intrinsic/extrinsic properties of the gelatin-based hydrogels in organ 3D bioprinting areas with advanced technologies, theories and principles. The state of the art of the physical/chemical crosslinking methods of the gelatin-based hydrogels being used to overcome the weak mechanical properties is highlighted. A multicellular model made from adipose-derived stem cell proliferation and differentiation in the predefined 3D constructs is emphasized. Multi-nozzle extrusion-based organ 3D bioprinting technologies have the distinguished potential to eventually manufacture implantable bioartificial organs for purposes such as customized organ restoration, high-throughput drug screening and metabolic syndrome model establishment.

  6. Preparation and Characterization of Gelatin Nanofibers Containing Silver Nanoparticles

    Science.gov (United States)

    Jeong, Lim; Park, Won Ho

    2014-01-01

    Ag nanoparticles (NPs) were synthesized in formic acid aqueous solutions through chemical reduction. Formic acid was used for a reducing agent of Ag precursor and solvent of gelatin. Silver acetate, silver tetrafluoroborate, silver nitrate, and silver phosphate were used as Ag precursors. Ag+ ions were reduced into Ag NPs by formic acid. The formation of Ag NPs was characterized by a UV-Vis spectrophotometer. Ag NPs were quickly generated within a few minutes in silver nitrate (AgNO3)/formic acid solution. As the water content of formic acid aqueous solution increased, more Ag NPs were generated, at a higher rate and with greater size. When gelatin was added to the AgNO3/formic acid solution, the Ag NPs were stabilized, resulting in smaller particles. Moreover, gelatin limits further aggregation of Ag NPs, which were effectively dispersed in solution. The amount of Ag NPs formed increased with increasing concentration of AgNO3 and aging time. Gelatin nanofibers containing Ag NPs were fabricated by electrospinning. The average diameters of gelatin nanofibers were 166.52 ± 32.72 nm, but these decreased with the addition of AgNO3. The average diameters of the Ag NPs in gelatin nanofibers ranged between 13 and 25 nm, which was confirmed by transmission electron microscopy (TEM). PMID:24758929

  7. Molecular interactions in gelatin/chitosan composite films.

    Science.gov (United States)

    Qiao, Congde; Ma, Xianguang; Zhang, Jianlong; Yao, Jinshui

    2017-11-15

    Gelatin and chitosan were mixed at different mass ratios in solution forms, and the rheological properties of these film-forming solutions, upon cooling, were studied. The results indicate that the significant interactions between gelatin and chitosan promote the formation of multiple complexes, reflected by an increase in the storage modulus of gelatin solution. Furthermore, these molecular interactions hinder the formation of gelatin networks, consequently decreasing the storage modulus of polymer gels. Both hydrogen bonds and electrostatic interactions are formed between gelatin and chitosan, as evidenced by the shift of the amide-II bands of polymers. X-ray patterns of composite films indicate that the contents of triple helices decrease with increasing chitosan content. Only one glass transition temperature (T g ) was observed in composite films with different composition ratios, and it decreases gradually with an increase in chitosan proportion, indicating that gelatin and chitosan have good miscibility and form a wide range of blends. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. The role of three-dimensional pure bovine gelatin scaffolds in tendon healing, modeling, and remodeling: an in vivo investigation with potential clinical value.

    Science.gov (United States)

    Oryan, Ahmad; Sharifi, Pardis; Moshiri, Ali; Silver, Ian A

    2017-09-01

    Large tendon defects involving extensive tissue loss present complex clinical problems. Surgical reconstruction of such injuries is normally performed by transplanting autogenous and allogenous soft tissues that are expected to remodel to mimic a normal tendon. However, the use of grafts has always been associated with significant limitations. Tissue engineering employing artificial scaffolds may provide acceptable alternatives. Gelatin is a hydrolyzed form of collagen that is bioactive, biodegradable, and biocompatible. The present study has investigated the suitability of gelatin scaffold for promoting healing of a large tendon-defect model in rabbits. An experimental model of a large tendon defect was produced by partial excision of the Achilles tendon of the left hind leg in adult rabbits. To standardize and stabilize the length of the tendon defect a modified Kessler core suture was anchored in the sectioned tendon ends. The defects were either left untreated or filled with three-dimensional gelatin scaffold. Before euthanasia 60 days after injury, the progress of healing was evaluated clinically. Samples of healing tendon were harvested at autopsy and evaluated by gross, histopathologic, scanning, and transmission electron microscopy, and by biomechanical testing. The treated animals showed superior weight-bearing and physical activity compared with those untreated, while frequency of peritendinous adhesions around the healing site was reduced. The gelatin scaffold itself was totally degraded and replaced by neo-tendon that morphologically had significantly greater numbers, diameters, density, and maturation of collagen fibrils, fibers, and fiber bundles than untreated tendon scar tissue. It also had mechanically higher ultimate load, yield load, stiffness, maximum stress and elastic modulus, when compared to the untreated tendons. Gelatin scaffold may be a valuable option in surgical reconstruction of large tendon defects.

  9. Effect of vibration duration of high ultrasound applied to bio-composite while gelatinized on its properties.

    Science.gov (United States)

    Abral, Hairul; Putra, Genda J; Asrofi, Mohammad; Park, Ji-Won; Kim, Hyun-Joong

    2018-01-01

    This article reports effect of vibration duration of high ultrasound applied to bio-composite while gelatinized on its properties. The bio-composite consists of mixing of both the tapioca starch based bioplastic and oil palm empty fruit bunch (OPEFB) fibers with high volume fraction. Gelatinization of the bio-composite sample was poured into a rectangular glass mold placed then in an ultrasonic bath with 40kHz, and 250watt in different duration for 0, 15, 30, 60min respectively. The results show that vibration during gelatinization has changed the characterisation of the bio-composite. SEM photograph displayed different fracture surface of tensile sample. For vibration duration of 60min, tensile strength (TM), and tensile modulus (TM) was improved to 64.4, 277.4%, respectively, meanwhile strain was decreased to 35.1% in comparison without vibration. Fourier Transform Infrared Spectroscopy (FTIR), and XRD diffraction of the bio-composite has changed due to various vibration duration. Moisture absorption of the vibrated bio-composite was lower than that of the untreated one. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Effect of egg albumen protein addition on physicochemical properties and nanostructure of gelatin from fish skin.

    Science.gov (United States)

    Cai, Luyun; Feng, Jianhui; Peng, Xichun; Regenstein, Joe M; Li, Xiuxia; Li, Jianrong; Zhao, Wei

    2016-12-01

    The physicochemical properties and nanostructure of mixtures of egg albumen protein (EAP) and gelatin from under-utilised grass carp ( Ctenopharyngodon idella ) skins were studied. The gelatin with 1% EAP had an acceptable gel strength. The addition of 5% EAP significantly increased the melting and gelling temperatures of gelatin gels. Additionally, the colour turned white and the crystallinity was higher in gelatin gels with gradient concentrations of EAP (1, 3, and 5%). Gelatin with 5% EAP had the highest G' values while gelatin with 1% EAP had the lowest G' values. Atomic force microscopy showed the heterogeneous nanostructure of fish gelatin, and a simple coacervate with a homogeneous distribution was only observed with the addition of 1% EAP, indicating interaction between gelatin and EAP. These results showed that EAP effect fish gelatin's physicochemical and nanostructure properties and has potential applications in foods and pharmaceuticals.

  11. Comparison of water gel desserts from fish skin and pork gelatins using instrumental measurements.

    Science.gov (United States)

    Zhou, Peng; Regenstein, Joe M

    2007-05-01

    The objective of this study was to compare water gel desserts from various gelatins using instrumental measurements. The puncture test and texture profile analysis (TPA) with compression were determined at 25% and 75% deformation; the melting properties were determined rheologically by monitoring the change of storage modulus (G') with increasing temperature. The measurements with 25% deformation were always nondestructive, while measurements with 75% deformation were mostly destructive. Desserts made from Alaska pollock gelatin (AG) or gelatin mixtures containing AG were more resistant to the destruction caused by the large deformation than tilapia gelatin and pork gelatins. In addition, the gel dessert made from AG melted at a lower temperature than those from tilapia skin gelatin and pork gelatins, while desserts made from gelatin mixtures reflected the melting properties of the separate gelatins.

  12. The physico-chemical properties of pangas catfish (Pangasius pangasius) skin gelatin

    Science.gov (United States)

    Pradarameswari, K. A.; Zaelani, K.; Waluyo, E.; Nurdiani, R.

    2018-04-01

    Gelatin can be used as emulsifier and stabilizer in food products. Until now, the most widely used raw materials for the production of gelatin industry are cow bone, cow skin and pig skin. Fish gelatin has been highlighted as a better alternative to replace mammals gelatin based on ethical and religious perspective. Fish gelatin was extracted from Pangas catfish skin to determine its physico-chemical properties. Different temperatures (45 °C, 50 °C, 55 °C) were employed during gelatin extraction. Higher temperature increased the yield and fat contents of Pangas catfish skin gelatin. In contrary, higher water, protein, ash contents were observed during lower temperature. Temperature significantly (p fish skin gelatin. Based on the FTIR spectrum catfish skin gelatin functional groups can be identified as N-H, O-H, C = H, C-O and C-H.

  13. Photocurable surgical tissue adhesive glues composed of photoreactive gelatin and poly(ethylene glycol) diacrylate.

    Science.gov (United States)

    Nakayama, Y; Matsuda, T

    1999-01-01

    This article presents a novel photochemically driven surgical tissue adhesive technology using photoreactive gelatins and a water-soluble difunctional macromer (poly(ethylene glycol) diacrylate: PEGDA).The gelatins were partially derivatized with photoreactive groups, such as ultraviolet light (UV)-reactive benzophenone and visible light-reactive xanthene dye (e.g., fluorescein sodium salt, eosin Y, and rose bengal). A series of the prepared photocurable tissue adhesive glues, consisting of the photoreactive gelatin, PEGDA, and a saline solution with or without ascorbic acid as a reducing agent, were viscous solutions under warming, and their effectiveness was evaluated as hemostasis- and anastomosis-aid in cardiovascular surgery. Regardless of the type of photoreactive groups, the irradiation of the photocurable tissue adhesive glues by UV or visible light within 1 min produced water-swollen gels, which had a high adhesive strength to wet collagen film. These were due to the synergistic action of photoreactive group-initiated photo-cross-linking and photograft polymerization. An increase in the irradiation time resulted in increased gel yield and reduced water swellability. A decrease in the molecular weight of PEGDA and an increase in concentration of both gelatin and PEGDA resulted in reduced water swellability and increased tensile and burst strengths of the resultant gels. In rats whose livers were injured with a trephine in laparotomy, the bleeding spots were coated with the photocurable adhesive glue and irradiated through an optical fiber. The coated solution was immediately converted to a swollen gel. The gel was tightly adhered to the liver tissue presumably by interpenetration, and concomitantly hemostasis was completed. The anastomosis treatment with the photocurable glue in the canine abdominal or thoracic aortas incised with a knife resulted in little bleeding under pulsatile flow after declamping. Histological examination showed that the glues

  14. Ion-exchange fibers for uranium recovery. Final report, September 8, 1980-November 6, 1981

    International Nuclear Information System (INIS)

    Babcock, W.C.

    1981-01-01

    Development was initiated of ion-exchange fibers that could be used to extract uranium ions from solutions containing 10 ppM uranium or less, such as acid mine waters, leach solutions, various natural groundwaters, and perhaps even seawater. These fibers would ultimately be used to make large, loosely woven mats that could be placed in dilute solutions or uranium. Periodically, the mats would be removed and stripped of uranium with an appropriate solution. Two major approaches to making these fibers were investigated. One involved incorporating conventional amine solvent-extraction reagents into the pores of microporous, polysulfone fibers. This approach was unsuccessful due to a rapid loss of the reagents from the fibers. The second approach was to incorporate water-swollen gels of polymeric amines into the pores of the fibers. These fibers effectively extracted uranium from solutions containing 10 ppM uranium. An economic analysis based on the projected costs of mats made from these fibers and on the value of the uranium recovered by the fibers shows that the mats could be used to economically recover uranium from dilute solutions and that they offer a substantial cost advantage over conventional ion exchange

  15. Photorefractive Fibers

    National Research Council Canada - National Science Library

    Kuzyk, Mark G

    2003-01-01

    ... scope of the project. In addition to our work in optical limiting fibers, spillover results included making fiber-based light-sources, writing holograms in fibers, and developing the theory of the limits of the nonlinear...

  16. Controlled Fabrication of Gelatin Nanoparticles as Drug Carriers

    Science.gov (United States)

    Jahanshahi, M.; Sanati, M. H.; Minuchehr, Z.; Hajizadeh, S.; Babaei, Z.

    2007-08-01

    In recent years, significant effort has been devoted to develop nanotechnology for drug delivery since it offers a suitable means of delivering small molecular weight drugs, as well as macromolecules such as proteins, peptides or genes by either localized or targeted delivery to the tissue of interest. Nanotechnology focuses on formulating therapeutic agents in biocompatible nanocomposites such as nanoparticles, nanocapsules, micellar systems, and conjugates. Protein nanoparticles (BSA, HAS and gelatin) generally vary in size from 50-300 nm and they hold certain advantages such as greater stability during storage, stability in vivo, non-toxicity, non-antigen and ease to scale up during manufacture over the other drug delivery systems. The primary structure of gelatin offers many possibilities for chemical modification and covalent drug attachment. Here nanoparticles of gelatin type A were prepared by a two-step desolvation method as a colloidal drug delivery system and the essential parameters in fabrication were considered. Gelatin was dissolved in 25 mL distilled water under room temperature range. Then acetone was added to the gelatin solution as a desolvating agent to precipitate the high molecular weight (HMW) gelatin. The supernatant was discarded and the HMW gelatin re-dissolved by adding 25 mL distilled water and stirring at 600 rpm. Acetone were added drop-wise to form nanoparticles. At the end of the process, glutaraldehyde solution was used for preparing nanoparticles as a cross-linking agent, and stirred for 12h at 600 rpm. For purification stage we use centrifuge with 600rpm for 3 times. The objective of the present study is consideration of some factors such as temperature, gelatin concentration, agitation speed and the amount of acetone and their effects on size and distribution of nanoparticles. Among the all conditions, 60° C, 50 mg/ml gelatin concentration, 75 ml acetone had the best result and the nanoparticle size was under 170 nm. The effect

  17. Electrospinning and stabilization of chitosan nanofiber mats

    Science.gov (United States)

    Grimmelsmann, N.; Grothe, T.; Homburg, S. V.; Ehrmann, A.

    2017-10-01

    Chitosan is of special interest for biotechnological and medical applications due to its antibacterial, antifungal and other intrinsic physical and chemical properties. The biopolymer can, e.g., be used for biotechnological purposes, as a filter medium, in medical products, etc. In all these applications, the inner surface should be maximized to increase the contact area with the filtered medium etc. and thus the chitosan’s efficacy. Chitosan dissolves in acidic solutions, opposite to neutral water. Electrospinning is possible, e.g., by co-spinning with PEO (poly(ethylene oxide)). Tests with different chitosan:PEO ratios revealed that higher PEO fractions resulted in better spinnability and more regular fibre mats, but make stabilization of the fibre structure more challenging.

  18. Flygande mat - kabinpersonals måltidssituation

    OpenAIRE

    Johansson, Johanna; Hugosson, Ellen

    2015-01-01

    Inledning Yrket som kabinanställd inom flyget präglas av serviceanda och ansvar för passagerares säkerhet. Arbetsmiljön innebär fysiska påfrestningar vad gäller till exempel kabintryck och låg syrenivå. Mat och måltider intas under olika tider på dygnet och infaller sällan på normala måltidstider. Kabinpersonalens måltider regleras av regler, avtal och policyer rörande arbetstidens längd. Syfte Syftet var att undersöka kabinpersonalens måltider under arbetstid, med fokus på riktlinjer och pol...

  19. MAT@USC Candidates and Latino English Language Learners

    Science.gov (United States)

    Lomeli, Cynthia Leticia

    2012-01-01

    The purpose of this study was to further understand the perceptions of MAT@USC teacher candidates and how their perceptions and previous experiences affect the educational experiences of Latino English language learners. Three questions were developed to guide this study: (1) What are the perceptions of MAT@USC candidates in selected courses…

  20. Matting Of Hair Due To ′Sunsilk′ Shampoo

    Directory of Open Access Journals (Sweden)

    Nadeem Mohd

    1995-01-01

    Full Text Available Matting of hair been reported from time to time due to treatment of hair with detergent, shampoos, waving lotions, setting lotions and bleaches. A case of matting of hairs in a young girl due to a change in the brand of shampoo is reported.

  1. Effects of preprocessing method on TVOC emission of car mat

    Science.gov (United States)

    Wang, Min; Jia, Li

    2013-02-01

    The effects of the mat preprocessing method on total volatile organic compounds (TVOC) emission of car mat are studied in this paper. An appropriate TVOC emission period for car mat is suggested. The emission factors for total volatile organic compounds from three kinds of new car mats are discussed. The car mats are preprocessed by washing, baking and ventilation. When car mats are preprocessed by washing, the TVOC emission for all samples tested are lower than that preprocessed in other methods. The TVOC emission is in stable situation for a minimum of 4 days. The TVOC emitted from some samples may exceed 2500μg/kg. But the TVOC emitted from washed Polyamide (PA) and wool mat is less than 2500μg/kg. The emission factors of total volatile organic compounds (TVOC) are experimentally investigated in the case of different preprocessing methods. The air temperature in environment chamber and the water temperature for washing are important factors influencing on emission of car mats.

  2. Characterisation of electrospun gelatine nanofibres encapsulated with Moringa oleifera bioactive extract.

    Science.gov (United States)

    Hani, Norziah M; Torkamani, Amir E; Azarian, Mohammad H; Mahmood, Kamil Wa; Ngalim, Siti Hawa

    2017-08-01

    Drumstick (Moringa oleifera) leaves have been used as a folk herbal medicine across many cultures since ancient times. This is most probably due to presence of phytochemicals possessing antioxidant properties, which could retard oxidative stress, and their degenerative effect. The current study deals with nanoencapsulation of Moringa oleifera (MO) leaf ethanolic extract within fish sourced gelatine matrix using electrospinning technique. The total phenolic and flavonoid content, radical scavenging (IC 50 ) and metal reducing properties were 67.0 ± 2.5 mg GAE g -1 sample 32.0 ± 0.5 mg QE g -1 extract, 0.08 ± 0.01 mg mL -1 and 510 ± 10 µmol eq Fe(II) g -1 extract, respectively. Morphological and spectroscopic analysis of the fibre mats confirmed successful nanoencapsulation of MO extract within defect free nanofibres via electrospinning process. The percentage encapsulation efficiency (EE) was between 80% and 85%. Furthermore, thermal stability of encapsulated fibres, especially at 3% and 5% of core loading content, was significantly improved. Toxicological analysis revealed that the extract in its original and encapsulated form was safe for oral consumption. Overall, the present study showed the potential of ambient temperature electrospinning process as a safe nanoencapsulation method, where MO extract retained its antioxidative capacities. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  3. In Situ Production of Graphene-Fiber Hybrid Structures

    DEFF Research Database (Denmark)

    Akia, Mandana; Cremar, Lee; Chipara, Mircea

    2017-01-01

    We report a scalable method to obtain a new material where large graphene sheets form webs linking carbon fibers. Film-fiber hybrid nonwoven mats are formed during fiber processing and converted to carbon structures after a simple thermal treatment. This contrasts with multistep methods...... that attempt to mix previously prepared graphene and fibers, or require complicated and costly processes for deposition of graphene over carbon fibers. The developed graphene-fiber hybrid structures have seamless connections between graphene and fibers, and in fact the graphene "veils" extend directly from one...... a capillarity effect that promoted the formation of thin veils, which become graphene sheets upon dehydration by sulfuric acid vapor followed by carbonization (at relatively low temperatures, below 800 °C). These veils extend over several micrometers within the pores of the fiber network, and consist...

  4. Microbial mat ecosystems: Structure types, functional diversity, and biotechnological application

    Directory of Open Access Journals (Sweden)

    Cristina M. Prieto-Barajas

    2018-01-01

    Full Text Available Microbial mats are horizontally stratified microbial communities, exhibiting a structure defined by physiochemical gradients, which models microbial diversity, physiological activities, and their dynamics as a whole system. These ecosystems are commonly associated with aquatic habitats, including hot springs, hypersaline ponds, and intertidal coastal zones and oligotrophic environments, all of them harbour phototrophic mats and other environments such as acidic hot springs or acid mine drainage harbour non-photosynthetic mats. This review analyses the complex structure, diversity, and interactions between the microorganisms that form the framework of different types of microbial mats located around the globe. Furthermore, the many tools that allow studying microbial mats in depth and their potential biotechnological applications are discussed.

  5. Enhanced Piezoelectricity in a Robust and Harmonious Multilayer Assembly of Electrospun Nanofiber Mats and Microbead-Based Electrodes.

    Science.gov (United States)

    Kim, Young Won; Lee, Han Bit; Yeon, Si Mo; Park, Jeanho; Lee, Hye Jin; Yoon, Jonghun; Park, Suk Hee

    2018-02-14

    Here, we present a simple yet highly efficient method to enhance the output performance of a piezoelectric device containing electrospun nanofiber mats. Multiple nanofiber mats were assembled together to harness larger piezoelectric sources in the as-spun fibers, thereby providing enhanced voltage and current outputs compared to those of a single-mat device. In addition to the multilayer assembly, microbead-based electrodes were integrated with the nanofiber mats to deliver a complexed compression and tension force excitation to the piezoelectric layers. A vacuum-packing process was performed to attain a tight and well-organized assembly of the device components even though the total thickness was several millimeters. The integrated piezoelectric device exhibited a maximum voltage and current of 10.4 V and 2.3 μA, respectively. Furthermore, the robust integrity of the device components could provide high-precision sensitivity to perceive small pressures down to approximately 100 Pa while retaining a linear input-output relationship.

  6. Characterization and cytological effects of a novel glycated gelatine substrate

    International Nuclear Information System (INIS)

    Boonkaew, Benjawan; Supaphol, Pitt; Tompkins, Kevin; Manokawinchoke, Jeeranan; Pavasant, Prasit

    2014-01-01

    Hyperglycemia in diabetes results in the glycation of long-lived proteins. Protein glycation leads to the formation of advanced glycation end products (AGEs), which are implicated in delayed wound healing and other diabetes-associated pathologies, one of which is periodontal disease. Research into the mechanisms by which glycated long-lived proteins such as collagen exert their effects can allow for the understanding of diabetic pathologies and the development of appropriate treatments. However, the high cost of purified protein can be a limitation for many laboratories around the world. The objective of this study was to develop a low-cost in vitro model of glycated gelatine as an alternative to the glycated collagen model. We investigated the glycation of gelatine type A, a denatured form of collagen, which is low-cost and abundantly available. In this study, gelatine was incubated for 7 days with ribose or methylglyoxal (MG). Cross-linking, autofluorescence and UV–Vis spectrophotometry assays were performed and indicated a dose-dependent linear increase in cross-linking and autofluorescence of gelatine by ribose and MG. MG produced more cross-linking compared to ribose at the same concentrations. The UV–Vis spectra of the glycated gelatines confirmed the presence of AGE fluorophores. Because diabetes is a risk factor for periodontal disease, the effect of the glycated substrates on the basic behaviour of human periodontal ligament (HPDL) cells was evaluated. Glycation dose dependently reduced HPDL attachment and cell spreading, indicating that the novel glycated gelatine substrate affects cell behaviour. These results show that gelatine glycated with ribose or MG can be used as low-cost in vitro models to study the effects of protein glycation on cell behaviour in diabetes and ageing. (paper)

  7. Spatial patterns of cyanobacterial mat growth on sand ripples

    Science.gov (United States)

    Mariotti, G.; Klepac-Ceraj, V.; Perron, J. T.; Bosak, T.

    2016-02-01

    Photosynthetic microbial mats produce organic matter, cycle nutrients, bind pollutants and stabilize sediment in sandy marine environments. Here, we investigate the influence of bedforms and wave motion on the growth rate, composition and spatial variability of microbial mats by growing cyanobacterial mats on a rippled bed of carbonate sand in a wave tank. The tank was forced with an oscillatory flow with velocities below the threshold for sediment motion yet able to induce a porewater flow within the sediment. Different spatial patterns developed in mats depending on the initial biochemistry of the water medium. When growing in a medium rich in nitrogen, phosphorous and micronutrients, mats grew faster on ripple troughs than on ripple crests. After two months, mats covered the bed surface uniformly, and the microbial communities on the crests and in the troughs had similar compositions. Differences in bed shear stress and nutrient availability between crests and troughs were not able to explain the faster growth in the troughs. We hypothesize that this growth pattern is due to a "strainer" effect, i.e. the suspended bacteria from the inoculum were preferentially delivered to troughs by the wave-induced porewater flow. In the experiments initiated in a medium previously used up by a microbial mat and thus depleted in nutrients, mats grew preferentially on the ripple crests. This spatial pattern persisted for nearly two years, and the microbial composition on troughs and crests was different. We attribute this pattern to the upwelling of porewater in the crests, which increased the delivery of nutrients from sediment to the cyanobacteria on the bed surface. Thus, the macroscopic patterns formed by photosynthetic microbial mats on sand ripples may be used to infer whether mats are nutrient-limited and whether they are recently colonized or older than a month.

  8. Diversity and stratification of archaea in a hypersaline microbial mat.

    Science.gov (United States)

    Robertson, Charles E; Spear, John R; Harris, J Kirk; Pace, Norman R

    2009-04-01

    The Guerrero Negro (GN) hypersaline microbial mats have become one focus for biogeochemical studies of stratified ecosystems. The GN mats are found beneath several of a series of ponds of increasing salinity that make up a solar saltern fed from Pacific Ocean water pumped from the Laguna Ojo de Liebre near GN, Baja California Sur, Mexico. Molecular surveys of the laminated photosynthetic microbial mat below the fourth pond in the series identified an enormous diversity of bacteria in the mat, but archaea have received little attention. To determine the bulk contribution of archaeal phylotypes to the pond 4 study site, we determined the phylogenetic distribution of archaeal rRNA gene sequences in PCR libraries based on nominally universal primers. The ratios of bacterial/archaeal/eukaryotic rRNA genes, 90%/9%/1%, suggest that the archaeal contribution to the metabolic activities of the mat may be significant. To explore the distribution of archaea in the mat, sequences derived using archaeon-specific PCR primers were surveyed in 10 strata of the 6-cm-thick mat. The diversity of archaea overall was substantial albeit less than the diversity observed previously for bacteria. Archaeal diversity, mainly euryarchaeotes, was highest in the uppermost 2 to 3 mm of the mat and decreased rapidly with depth, where crenarchaeotes dominated. Only 3% of the sequences were specifically related to known organisms including methanogens. While some mat archaeal clades corresponded with known chemical gradients, others did not, which is likely explained by heretofore-unrecognized gradients. Some clades did not segregate by depth in the mat, indicating broad metabolic repertoires, undersampling, or both.

  9. Investigating Linear and Nonlinear Viscoelastic behaviour and microstructures of Gelatine-Multiwalled carbon nanotubes composites

    KAUST Repository

    Yang, Zhi

    2015-12-01

    We have investigated the linear and nonlinear rheology of various gelatine-multiwalled carbon nanotube (gel-MWNT) composites, namely physically-crosslinked-gelatine gel-MWNT composites, chemically-crosslinked-gelatine gel-MWNT composites, and chemically-physically-crosslinked-gelatine gel-MWNT composites. Further, the internal structures of these gel-MWNT composites were characterized by ultra-small angle neutron scattering and scanning electron microscopy. The adsorption of gelatine onto the surface of MWNT is also investigated to understand gelatine-assisted dispersion of MWNT during ultrasonication. For all gelatine gels, addition of MWNT increases their complex modulus. The dependence of storage modulus with frequency for gelatine-MWNT composites is similar to that of the corresponding neat gelatine matrix. However, by incorporating MWNT, the dependence of the loss modulus on frequency is reduced. The linear viscoelastic region is decreased approximately linearly with the increase of MWNT concentration. The pre-stress results demonstrate that the addition of MWNT does not change the strain-hardening behaviour of physically-crosslinked gelatine gel. However, the addition of MWNT can increase the strain-hardening behaviour of chemically-crosslinked gelatine gel, and chemically-physically crosslinked gelatine gel. Results from light microscopy, cryo-SEM, and USANS demonstrate the hierarchical structures of MWNT, including that tens-of-micron scale MWNT agglomerates are present. Furthermore, the adsorption curve of gelatine onto the surface of MWNT follows two-stage pseudo-saturation behaviour.

  10. Massive consumption of gelatinous plankton by Mediterranean apex predators.

    Directory of Open Access Journals (Sweden)

    Luis Cardona

    Full Text Available Stable isotopes of carbon and nitrogen were used to test the hypothesis that stomach content analysis has systematically overlooked the consumption of gelatinous zooplankton by pelagic mesopredators and apex predators. The results strongly supported a major role of gelatinous plankton in the diet of bluefin tuna (Thunnus thynnus, little tunny (Euthynnus alletteratus, spearfish (Tetrapturus belone and swordfish (Xiphias gladius. Loggerhead sea turtles (Caretta caretta in the oceanic stage and ocean sunfish (Mola mola also primarily relied on gelatinous zooplankton. In contrast, stable isotope ratios ruled out any relevant consumption of gelatinous plankton by bluefish (Pomatomus saltatrix, blue shark (Prionace glauca, leerfish (Lichia amia, bonito (Sarda sarda, striped dolphin (Stenella caerueloalba and loggerhead sea turtles (Caretta caretta in the neritic stage, all of which primarily relied on fish and squid. Fin whales (Balaenoptera physalus were confirmed as crustacean consumers. The ratios of stable isotopes in albacore (Thunnus alalunga, amberjack (Seriola dumerili, blue butterfish (Stromaeus fiatola, bullet tuna (Auxis rochei, dolphinfish (Coryphaena hyppurus, horse mackerel (Trachurus trachurus, mackerel (Scomber scombrus and pompano (Trachinotus ovatus were consistent with mixed diets revealed by stomach content analysis, including nekton and crustaceans, but the consumption of gelatinous plankton could not be ruled out completely. In conclusion, the jellyvorous guild in the Mediterranean integrates two specialists (ocean sunfish and loggerhead sea turtles in the oceanic stage and several opportunists (bluefin tuna, little tunny, spearfish, swordfish and, perhaps, blue butterfish, most of them with shrinking populations due to overfishing.

  11. Characterization of pre-gelatinized rice and bean flour

    Directory of Open Access Journals (Sweden)

    Ana Vânia Carvalho

    2013-06-01

    Full Text Available The objective of this study was to develop a pre-gelatinized flour using a mixture of broken rice and split beans by thermoplastic extrusion, and to evaluate the physicochemical, nutritional, and technological quality of the final product. The extrusion parameters were maintained using three heating zones with temperatures of 30 ºC, 40 ºC, and 70 ºC; screw speed of 177 rpm; feed rate of 257 g/m, and circular matrix of 3.85 mm. The following characterization analyses were performed: physicochemical, nutritional, water absorption index (WAI, water solubility index (WSI, and paste viscosity. The pre-gelatinized rice and bean flour had an intermediate value of WAI, 7.51 g/g, and high WSI value, 24.61%. Regarding proteins, it was verified an average content of 12.9% in the final product. The amino acid contents found in the pre-gelatinized flour indicate that the mixture has the essential amino acids. It was also found that the pre-gelatinized flour supplies more than 60% of the essential amino acids recommended for children aged one to three years old. The gelatinized flour composed of broken rice and split beans is an alternative to the use of these by-products of the manufacture process of rice and beans to obtain a product with viable technological characteristics and high nutritional value.

  12. Investigations on the Chemical Degradation of Silver Gelatine Prints

    Directory of Open Access Journals (Sweden)

    Maha Ahmed ALI

    2012-06-01

    Full Text Available Photographs are considered composite objects with complex chemical and physical structures. Therefore they are more prone to damage as compared to other objects. Chemical degradation is by far the most common decay form found among photographic collections. This study investigates the chemical degradation of silver gelatin prints (DOP and the reaction of the image, silver, gelatin, and paper to accelerated aging, to the action of light, and oxidizing gases, in terms of their physical and chemical nature. The test materials used are properly washed and poorly washed grayscale, black-and-white processed images on photographic paper (Black & White Photographic Paper BH 0 Bromofort 6P0661 Tropical from Forte Photochemical Company Vác, Hungary. After exposure, the results were studied by means of visual inspection, amino acid analyzer, Fourier transform infrared and transmission electron microscope. The results were compared with those of the control samples. Our study revealed that the image, silver, gelatin and photographic paper are greatly affected by oxidizing agents and that the effect increased if the photographic prints were inadequately washed at the time of their processing. Furthermore, our results indicated that an increased amount of ammonia and amino acid in the silver gelatin print is a reliable indicator of the degradation of its gelatine emulsion.

  13. Fiber dielectrophoresis

    International Nuclear Information System (INIS)

    Lipowicz, P.J.; Yeh, H.C.

    1988-01-01

    Dielectrophoresis is the motion of uncharged particles in nonuniform electric fields. We find that the theoretical dielectrophoretic velocity of a conducting fiber in an insulating medium is proportional to the square of the fiber length, and is virtually independent of fiber diameter. This prediction has been verified experimentally. The results point to the development of a fiber length classifier based on dielectrophoresis. (author)

  14. Investigating Linear and Nonlinear Viscoelastic behaviour and microstructures of Gelatine-Multiwalled carbon nanotubes composites

    KAUST Repository

    Yang, Zhi; Chaieb, Saharoui; Hemar, Yacine; deCampo, Liliana; Rehm, Christine; McGillivray, Duncan James

    2015-01-01

    , and chemically-physically-crosslinked-gelatine gel-MWNT composites. Further, the internal structures of these gel-MWNT composites were characterized by ultra-small angle neutron scattering and scanning electron microscopy. The adsorption of gelatine onto

  15. Antioxidative activity and emulsifying properties of cuttlefish skin gelatin modified by oxidised phenolic compounds

    NARCIS (Netherlands)

    Aewsiri, T.; Benjakul, S.; Visessanguan, W.; Eun, J.B.; Wierenga, P.A.; Gruppen, H.

    2009-01-01

    Antioxidative activity and emulsifying properties of cuttlefish skin gelatin modified by different oxidised phenolic compounds including caffeic acid, ferulic acid and tannic acid at different concentrations were investigated. Oxidised phenolic compounds were covalently attached to gelatin as

  16. Investigating Effects of Gelatin-Chitosan Film on Culture of Bone Marrow Stromal Cells in Rat

    Directory of Open Access Journals (Sweden)

    A Karami joyani

    2015-02-01

    Conclusion: Results of proliferation,differentiation and apoptosis cultured BMSCs on a gelatin-chitosan film showed that gelatin-chitosan film can be used as a good model of a biodegradable scaffold in tissue engineering and cell therapy.

  17. Fiber Amplifiers

    DEFF Research Database (Denmark)

    Rottwitt, Karsten

    2017-01-01

    The chapter provides a discussion of optical fiber amplifiers and through three sections provides a detailed treatment of three types of optical fiber amplifiers, erbium doped fiber amplifiers (EDFA), Raman amplifiers, and parametric amplifiers. Each section comprises the fundamentals including...... the basic physics and relevant in-depth theoretical modeling, amplifiers characteristics and performance data as a function of specific operation parameters. Typical applications in fiber optic communication systems and the improvement achievable through the use of fiber amplifiers are illustrated....

  18. Detection of porcine DNA in gelatine and gelatine-containing processed food products-Halal/Kosher authentication.

    Science.gov (United States)

    Demirhan, Yasemin; Ulca, Pelin; Senyuva, Hamide Z

    2012-03-01

    A commercially available real-time PCR, based on a multi-copy target cytochrome b (cyt b) using porcine specific primers, has been validated for the Halal/Kosher authentication of gelatine. Extraction and purification of DNA from gelatine were successfully achieved using the SureFood® PREP Animal system, and real-time PCR was carried out using SureFood® Animal ID Pork Sens kit. The minimum level of adulteration that could be detected was 1.0% w/w for marshmallows and gum drops. A small survey was undertaken of processed food products such as gum drops, marshmallows and Turkish delight, believed to contain gelatine. Of fourteen food products from Germany, two samples were found to contain porcine gelatine, whereas of twenty-nine samples from Turkey twenty-eight were negative. However, one product from Turkey contained porcine DNA and thus was not Halal, and neither was the use of porcine gelatine indicated on the product label. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Evaluation of tilapia skin gelatin as a mammalian gelatin replacer in acid milk gels and low-fat stirred yogurt.

    Science.gov (United States)

    Pang, Zhihua; Deeth, Hilton; Yang, Hongshun; Prakash, Sangeeta; Bansal, Nidhi

    2017-05-01

    Tilapia skin gelatin (TSG) was studied in a 3-stage process (cooling, annealing, and heating) for pure gelatin gels and in a 4-stage process (acidification, cooling, annealing, and heating) for acid milk gels and cultured yogurt. The aim was to evaluate the use of TSG as a replacement for mammalian gelatin in yogurt. In pure TSG gels, stronger gels with higher melting temperatures were formed with increasing TSG concentrations. Compared with bovine gelatin (BG), which gelled at a concentration of 2.5%, TSG gels had lower gelling (14.1°C) and melting (24°C) temperatures but comparable storage moduli during annealing. In acid milk gels, addition of TSG increased the firmness of the gels with increasing concentration. Gelling and melting points of TSG in milk gels were observed at sufficient concentrations during cooling and heating. Strands and sheets were observed in the electron micrographs of milk gels with 1% TSG and a very dense structure was observed with 2.5% TSG. Yogurt with 0.4% TSG had similar viscosity, consistency, pseudoplasticity, and thixotropy as yogurt containing 0.4% BG; no difference was perceived by sensory panelists according to a triangle test. Addition of 0.4% TSG completely prevented whey separation from the acid milk gel and yogurt. The results suggest that TSG could be a suitable replacement for mammalian gelatin in low-fat stirred yogurt. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  20. Novel formulations of ballistic gelatin. 1. Rheological properties.

    Science.gov (United States)

    Zecheru, Teodora; Său, Ciprian; Lăzăroaie, Claudiu; Zaharia, Cătălin; Rotariu, Traian; Stănescu, Paul-Octavian

    2016-06-01

    Ballistic gelatin is the simulant of the human body during field tests in forensics and other related fields, due to its physical and mechanical similarities to human trunk and organs. Since the ballistic gelatin used in present has important issues to overcome, an alternative approach is the use of gelatin-polymer composites, where a key factor is the insertion of biocompatible materials, which replicate accurately the human tissues. In order to be able to obtain an improved material in terms of mechanical performances by an easy industrial-scale technology, before the verification of the ballistic parameters by shooting in agreement with military standards, one of the best and cheapest solutions is to perform a thorough check of their rheological properties, in standard conditions. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  1. Drug delivery with microsecond laser pulses into gelatin

    Science.gov (United States)

    Shangguan, Hanqun; Casperson, Lee W.; Shearin, Alan; Gregory, Kenton W.; Prahl, Scott A.

    1996-07-01

    Photoacoustic drug delivery is a technique for localized drug delivery by laser-induced hydrodynamic pressure following cavitation bubble expansion and collapse. Photoacoustic drug delivery was investigated on gelatin-based thrombus models with planar and cylindrical geometries by use of one microsecond laser pulses. Solutions of a hydrophobic dye in mineral oil permitted monitoring of delivered colored oil into clear gelatin-based thrombus models. Cavitation bubble development and photoacoustic drug delivery were visualized with flash photography. This study demonstrated that cavitation is the governing mechanism for photoacoustic drug delivery, and the deepest penetration of colored oil in gels followed the bubble collapse. Spatial distribution measurements revealed that colored oil could be driven a few millimeters into the gels in both axial and radial directions, and the penetration was less than 500 mu m when the gelatin structure was not fractured. localized drug delivery, cavitation bubble, laser thrombolysis.

  2. Gelatin-Based Films and Coatings for Food Packaging Applications

    Directory of Open Access Journals (Sweden)

    Marina Ramos

    2016-09-01

    Full Text Available This review discusses the latest advances in the composition of gelatin-based edible films and coatings, including nanoparticle addition, and their properties are reviewed along their potential for application in the food packaging industry. Gelatin is an important biopolymer derived from collagen and is extensively used by various industries because of its technological and functional properties. Nowadays, a very wide range of components are available to be included as additives to improve its properties, as well as its applications and future potential. Antimicrobials, antioxidants and other agents are detailed due to the fact that an increasing awareness among consumers regarding healthy lifestyle has promoted research into novel techniques and additives to prolong the shelf life of food products. Thanks to its ability to improve global food quality, gelatin has been particularly considered in food preservation of meat and fish products, among others.

  3. Evaluating conditions for the formation of chitosan/gelatin microparticles

    Directory of Open Access Journals (Sweden)

    Marcia C. Silva

    2009-06-01

    Full Text Available Chitosan/gelatin microparticles were prepared by complex coacervation. Three chitosan (CH samples, with different acetylation degrees and intrinsic viscosities, were used together with commercial gelatin (G samples. Microparticles formation was investigated at various CH/G ratios, within the pH range of 3.5 to 6.0. Reactions were carried out at 40 and 60 ºC, for 2, 4, and 6 hours. Turbidity measurements performed at 633 nm were used to monitor the process. The resulting curves revealed maximum values, which were correlated to the glucosamine content of CH samples. After isolation, yields were determined, and the microparticles were characterized by infrared spectroscopy (FTIR and thermogravimetry (TGA. Both techniques evidenced the formation of coacervate microparticles. The highest yields in microparticles were determined for the system comprising the CH sample with the lowest degree of acetylation and intrinsic viscosity, and the gelatin sample with the lowest bloom strength.

  4. Nonvolatile Resistive Switching Memory Utilizing Cobalt Embedded in Gelatin

    Directory of Open Access Journals (Sweden)

    Cheng-Jung Lee

    2017-12-01

    Full Text Available This study investigates the preparation and electrical properties of Al/cobalt-embedded gelatin (CoG/ indium tin oxide (ITO resistive switching memories. Co. elements can be uniformly distributed in gelatin without a conventional dispersion procedure, as confirmed through energy dispersive X-ray analyzer and X-ray photoelectron spectroscopy observations. With an appropriate Co. concentration, Co. ions can assist the formation of an interfacial AlOx layer and improve the memory properties. High ON/OFF ratio, good retention capability, and good endurance switching cycles are demonstrated with 1 M Co. concentration, in contrast to 0.5 M and 2 M memory devices. This result can be attributed to the suitable thickness of the interfacial AlOx layer, which acts as an oxygen reservoir and stores and releases oxygen during switching. The Co. element in a solution-processed gelatin matrix has high potential for bio-electronic applications.

  5. Enhancement of recovery of Neisseria meningitidis by gelatin in blood culture media.

    OpenAIRE

    Pai, C H; Sorger, S

    1981-01-01

    The efficacy of gelatin for the recovery of Neisseria meningitidis from blood cultures was evaluated in a clinical setting. The organism was isolated from seven patients with meningococcal infections in blood culture media containing 1% gelatin. In contrast, only two blood cultures from these patients were positive in media without gelatin (P less than 0.05). Gelatin did not influence the recovery of other organisms isolated during this study. Conventional blood culture media may be supplemen...

  6. Preparation of Rhodamine B Fluorescent Poly(methacrylic acid) Coated Gelatin Nanoparticles

    OpenAIRE

    Gan, Zhenhai; Ju, Jianhui; Zhang, Ting; Wu, Daocheng

    2011-01-01

    Poly(methacrylic acid) (PMAA)-coated gelatin nanoparticles encapsulated with fluorescent dye rhodamine B were prepared by the coacervation method with the aim to retard the release of rhodamine B from the gelatin matrix. With sodium sulfate as coacervation reagent for gelatin, a kind of biopolymer with excellent biocompatibility, the formed gelatin nanoparticles were cross-linked by formaldehyde followed by the polymerization of methacrylic acid coating. The fluorescent poly(methacrylic acid)...

  7. Water flow and solute transport in floating fen root mats

    Science.gov (United States)

    Stofberg, Sija F.; EATM van der Zee, Sjoerd

    2015-04-01

    Floating fens are valuable wetlands, found in North-Western Europe, that are formed by floating root mats when old turf ponds are colonized by plants. These terrestrialization ecosystems are known for their biodiversity and the presence of rare plant species, and the root mats reveal different vegetation zones at a small scale. The vegetation zones are a result of strong gradients in abiotic conditions, including groundwater dynamics, nutrients and pH. To prevent irreversible drought effects such as land subsidence and mineralization of peat, water management involves import of water from elsewhere to maintain constant surface water levels. Imported water may have elevated levels of salinity during dry summers, and salt exposure may threaten the vegetation. To assess the risk of exposure of the rare plant species to salinity, the hydrology of such root mats must be understood. Physical properties of root mats have scarcely been investigated. We have measured soil characteristics, hydraulic conductivity, vertical root mat movement and groundwater dynamics in a floating root mat in the nature reserve Nieuwkoopse Plassen, in the Netherlands. The root mat mostly consists of roots and organic material, in which the soil has a high saturated water content, and strongly varies in its stage of decomposition. We have found a distinct negative correlation between degree of decomposition and hydraulic conductivity, similar to observations for bogs in the literature. Our results show that the relatively young, thin edge of the root mat that colonizes the surface water has a high hydraulic conductivity and floats in the surface water, resulting in very small groundwater fluctuations within the root mat. The older part of the root mat, that is connected to the deeper peat layers is hydrologically more isolated and the material has a lower conductivity. Here, the groundwater fluctuates strongly with atmospheric forcing. The zones of hydraulic properties and vegetation, appear to

  8. A modified gelatin zymography technique incorporating total protein normalization.

    Science.gov (United States)

    Raykin, Julia; Snider, Eric; Bheri, Sruti; Mulvihill, John; Ethier, C Ross

    2017-03-15

    Gelatinase zymography is a commonly used laboratory procedure; however, variability in sample loading and concentration reduce the accuracy of quantitative results obtained from this technique. To facilitate normalization of gelatinase activity by loaded protein amount, we developed a protocol using the trihalocompound 2,2,2-trichloroethanol to allow for gelatin zymography and total protein labeling within the same gel. We showed that detected protein levels increased linearly with loading, and describe a loading concentration range over which normalized gelatinase activity was constant. We conclude that in-gel total protein detection is feasible in gelatin zymography and greatly improves comparison of gelatinase activity between samples. Published by Elsevier Inc.

  9. UV, visible and IR laser interaction with gelatine

    International Nuclear Information System (INIS)

    Oujja, M; Rebollar, E; Abrusci, C; Amo, A Del; Catalina, F; Castillejo, M

    2007-01-01

    In this work we investigate the effects on gelatine films of nanosecond pulsed laser irradiation at different laser wavelengths from the UV to the IR at 248, 266, 355, 532 and 1064 nm. We compared gelatines differing in gel strength values (Bloom 75 and 225) and in crosslinking degree. Formation of bubbles at the wavelengths in the UV (248 and 266 nm), melting and resolidification at 355 nm, and formation of craters by ablation in the VIS and IR (532 and 1064 nm) are the observed morphological changes. On the other hand, changes of the fluorescence behaviour of the films upon UV irradiation reveal chemical modifications of photolabile chromophores

  10. Effects of ionizing radiation on gelatine films added with antioxidant

    International Nuclear Information System (INIS)

    Kraide, Felipe H.; Inamura, Patricia Y.; Mastro, Nelida L. del

    2011-01-01

    This work evaluates the effect of ionizing radiation on the gelatin films in presence of antioxidant. Gelatin solutions of glycerine and poly vinil alcohol, with and without the addition were prepared until the complete homogenization. The films were irradiated with 20 and 40 kGy in a electron accelerator, in the presence of air and at the room temperature. The use of ionizing radiation and the addition of antioxidant changed the properties of the film. The result of water absorption test revealed that with increasing of radiation dose occurred a reduction in the absorption, suggesting that happen a reticulation

  11. Microencapsulation of sulforaphane from broccoli seed extracts by gelatin/gum arabic and gelatin/pectin complexes.

    Science.gov (United States)

    García-Saldaña, Jesús S; Campas-Baypoli, Olga N; López-Cervantes, Jaime; Sánchez-Machado, Dalia I; Cantú-Soto, Ernesto U; Rodríguez-Ramírez, Roberto

    2016-06-15

    Sulforaphane is a phytochemical that has received attention in recent years due to its chemopreventive properties. However, the uses and applications of this compound are very limited, because is an unstable molecule that is degraded mainly by changes in temperature and pH. In this research, the use of food grade polymers for microencapsulation of sulforaphane was studied by a complex coacervation method using the interaction of oppositely charged polymers as gelatin/gum arabic and gelatin/pectin. The polymers used were previously characterized in moisture content, ash and nitrogen. The encapsulation yield was over 80%. The gelatin/pectin complex had highest encapsulation efficiency with 17.91%. The presence of sulforaphane in the complexes was confirmed by FTIR and UV/visible spectroscopy. The materials used in this work could be a new and attractive option for the protection of sulforaphane. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Composição químico-bromatológica e degradabilidade In Situ da matéria seca, proteína bruta e fibra em detergente neutro da casca do fruto de três variedades de maracujá (Passiflora spp Chemical composition and In situ degradability of dry matter, crude protein and neutral detergent fiber of three varieties passion fruit (Passiflora spp shelves

    Directory of Open Access Journals (Sweden)

    Cláudio Villela Vieira

    1999-01-01

    Full Text Available O objetivo deste trabalho foi avaliar a composição químico-bromatológica e as degradabilidades potenciais e efetivas da matéria seca (MS, proteína bruta (PB e fibra em detergente neutro (FDN do resíduo (casca das variedades de maracujá amarela (Passiflora edulis f. Flavicarpa Degener, roxa (Passiflora edulis Sims e doce (Passiflora alata e da mistura das variedades amarela e roxa. Calcularam-se, também, o consumo de MS e as concentrações de amônia, ácidos graxos voláteis e pH no líquido ruminal e a taxa de passagem das fases líquida e sólida da digesta no rúmen de bovinos. Os resíduos (casca in natura apresentaram grande quantidade de água, enquanto a variedade roxa apresentou o maior teor de matéria seca (17,01% e o amarelo, o menor (10,78%. O teor de proteína bruta variou de 9,82% na MS, para a variedade amarela, a 7,53%, para a doce. O teor de fósforo foi 0,13% na MS para a variedade doce, chegando a 0,09, para a roxo, e 0,08%, para a amarelo. Os teores de cálcio, FDN e FDA não diferiram entre as variedades. Às 48 horas de incubação no rúmen, a degradabilidade atingiu ponto máximo para o teor de MS, PB e FDN. Houve interação de tempo e variedade na degradabilidade de MS, PB e FDN. As degradabilidades de PB e FDN foram influenciadas pelas variedades. A DE da FDN foi maior para a mistura (45,85% e menor para a doce (34,61%. O consumo médio de MS foi de 16,90 kg/animal, equivalente a 3,27% do peso vivo ou 156,11 g/kg0,75, quando se utilizou farelo de casca (resíduo com 90% de MS. As concentrações de ácidos graxos voláteis mantiveram-se na faixa de 7,76 a 10,87 mmoles/100 mL. O pH do líquido ruminal variou de 6,03 a 6,75 e o N-amoniacal, de 4,93 a 9,86 mg/100 mL.Chemical composition and the potential and effective degradabilities of dry matter (DM, crude protein (CP and neutral detergent fiber (NDF of passion fruit residue (shelves were studied in the varieties yellow (Passiflora edulis f. Flavicarpa Degener

  13. Vulnerability of R-MAT networks with communities

    Directory of Open Access Journals (Sweden)

    Nikolay Alexandrovich Kinash

    2016-06-01

    Full Text Available A generator R-MAT for modeling networks with different laws of link constructions within and between communities has been developed. Network attack simulations have been performed and pertinent robustness of diverse network combinations has been concluded.

  14. Thermal Protection System Materials (TPSM): 3D MAT

    Data.gov (United States)

    National Aeronautics and Space Administration — The 3D MAT Project seeks to design and develop a game changing Woven Thermal Protection System (TPS) technology tailored to meet the needs of the Orion Multi-Purpose...

  15. Counting viruses and bacteria in photosynthetic microbial mats

    NARCIS (Netherlands)

    Carreira, C; Staal, M.; Middelboe, M.; Brussaard, C.P.D.

    2015-01-01

    Viral abundances in benthic environments are the highest found in aquatic systems. Photosynthetic microbial mats represent benthic environments with high microbial activity and possibly high viral densities, yet viral abundances have not been examined in such systems. Existing extraction procedures

  16. Biodiversity of the microbial mat of the Garga hot spring.

    Science.gov (United States)

    Rozanov, Alexey Sergeevich; Bryanskaya, Alla Victorovna; Ivanisenko, Timofey Vladimirovich; Malup, Tatyana Konstantinovna; Peltek, Sergey Evgenievich

    2017-12-28

    Microbial mats are a good model system for ecological and evolutionary analysis of microbial communities. There are more than 20 alkaline hot springs on the banks of the Barguzin river inflows. Water temperature reaches 75 °C and pH is usually 8.0-9.0. The formation of microbial mats is observed in all hot springs. Microbial communities of hot springs of the Baikal rift zone are poorly studied. Garga is the biggest hot spring in this area. In this study, we investigated bacterial and archaeal diversity of the Garga hot spring (Baikal rift zone, Russia) using 16S rRNA metagenomic sequencing. We studied two types of microbial communities: (i) small white biofilms on rocks in the points with the highest temperature (75 °C) and (ii) continuous thick phototrophic microbial mats observed at temperatures below 70 °C. Archaea (mainly Crenarchaeota; 19.8% of the total sequences) were detected only in the small biofilms. The high abundance of Archaea in the sample from hot springs of the Baikal rift zone supplemented our knowledge of the distribution of Archaea. Most archaeal sequences had low similarity to known Archaea. In the microbial mats, primary products were formed by cyanobacteria of the genus Leptolyngbya. Heterotrophic microorganisms were mostly represented by Actinobacteria and Proteobacteria in all studied samples of the microbial mats. Planctomycetes, Chloroflexi, and Chlorobi were abundant in the middle layer of the microbial mats, while heterotrophic microorganisms represented mostly by Firmicutes (Clostridia, strict anaerobes) dominated in the bottom part. Besides prokaryotes, we detect some species of Algae with help of detection their chloroplasts 16 s rRNA. High abundance of Archaea in samples from hot springs of the Baikal rift zone supplemented our knowledge of the distribution of Archaea. Most archaeal sequences had low similarity to known Archaea. Metagenomic analysis of microbial communities of the microbial mat of Garga hot spring showed that

  17. Carbon cycling and calcification in hypersaline microbial mats

    OpenAIRE

    Ludwig, Rebecca

    2004-01-01

    Phototrophic microbial mats are laminated aggregations of microorganisms that thrive in extreme and oligotrophic environments. Primary production rates by oxygenic phototrophs are extremely high. Primary producers supply heterotrophic mat members with organic carbon, which in turn regenerate CO2 needed for autotrophic carbon fixation. Another potential source of CO2 is calcification, which is known to shift the carbonate equilibrium towards CO2. This thesis investigated the carbon cycle of mi...

  18. Effect of Cell Sheet Manipulation Techniques on the Expression of Collagen Type II and Stress Fiber Formation in Human Chondrocyte Sheets.

    Science.gov (United States)

    Wongin, Sopita; Waikakul, Saranatra; Chotiyarnwong, Pojchong; Siriwatwechakul, Wanwipa; Viravaidya-Pasuwat, Kwanchanok

    2018-03-01

    Cell sheet technology is applied to human articular chondrocytes to construct a tissue-like structure as an alternative treatment for cartilage defect. The effect of a gelatin manipulator, as a cell sheet transfer system, on the quality of the chondrocyte sheets was investigated. The changes of important chondrogenic markers and stress fibers, resulting from the cell sheet manipulation, were also studied. The chondrocyte cell sheets were constructed with patient-derived chondrocytes using a temperature-responsive polymer and a gelatin manipulator as a transfer carrier. The properties of the cell sheets, including sizes, expression levels of collagen type II and I, and the localization of the stress fibers, were assessed and compared with those of the cell sheets harvested without the gelatin manipulator. Using the gelatin manipulator, the original size of the chondrocyte cell sheets was retained with abundant stress fibers, but with a decrease in the expression of collagen type II. Without the gelatin manipulator, although the cell shrinkage occurred, the cell sheet with suppressed stress fiber formation showed significantly higher levels of collagen type II. These results support our observations that stress fiber formation in chondrocyte cell sheets affected the production of chondrogenic markers. These densely packed tissue-like structures possessed a good chondrogenic activity, indicating their potential for use in autologous chondrocyte implantation to treat cartilage defects.

  19. Le matérialisme scientifique

    Science.gov (United States)

    Meunier, Jean-François

    2004-03-01

    De nos jours, il arrive quotidiennement aux grands hommes d'avoir à fréquenter d'ignorants mortels épris d'une conviction maladive que la science est la grande responsable de tous les maux du monde. Évidemment sans physique atomique, il n'y aurait pas eu d'Hiroshima et sans révolution industrielle, pas de pollution et etc. Cependant, ces accusations envers le progrès technique sont tout à fait injustes, irréfléchies et, j'irai même jusqu'à dire, irresponsables, puisque le calcul, i.e. la planification, même la plus élémentaire, est ce qui caractérise le mieux, pragmatiquement, la société humaine. À mon avis, les problèmes sociaux tireraient plutôt leur origine de sciences sociales irréalistes, qui, concrètment, inspireraient ou serviraient d'alibis à ceux qui détiennent véritablement le pouvoir. Dans cet article, je tenterai donc de démontrer la meilleure véracité et efficacité du matérialisme scientifique. Cette doctrine, dont Mario Bunge est le plus illustre représentant, s'appuy sur les résultats théoriques et expérimentaux des sciences factuelles ainsi que sur l'exactitude logique des mathématiques, utilisées ici comme langage universel de l'expression des idées. Cette conception philosophique qui s'inspire principalement du modèle des théories physiques, stipule que les réalités sociales sont, comme tout autre réalité, matérielles, mathématisables et représentables comme des systèmes en interaction. En fait, le modèle des physiciens ayant historiquement fait ses preuves en matière de testabilité et de cohérence interne est proposé d'être appliquer aux sciences sociales, aujourd'hui scindées des sciences dites pures sous l'inspiration des pseudo penseurs néo-kantiens, phénoménologiques et post-moderne. Cette nouvelle approche permettrait ainsi d'évoluer plus exactement vers une compréhension des bases sociales et biologiques du comportement humain afin de développer une éthique sans cesse plus r

  20. Functional electrospun fibers for the treatment of human skin wounds.

    Science.gov (United States)

    Wang, Jing; Windbergs, Maike

    2017-10-01

    Wounds are trauma induced defects of the human skin involving a multitude of endogenous biochemical events and cellular reactions of the immune system. The healing process is extremely complex and affected by the patient's physiological conditions, potential implications like infectious pathogens and inflammation as well as external factors. Due to increasing incidence of chronic wounds and proceeding resistance of infection pathogens, there is a strong need for effective therapeutic wound care. In this context, electrospun fibers with diameters in the nano- to micrometer range gain increasing interest. While resembling the structure of the native human extracellular matrix, such fiber mats provide physical and mechanical protection (including protection against bacterial invasion). At the same time, the fibers allow for gas exchange and prevent occlusion of the wound bed, thus facilitating wound healing. In addition, drugs can be incorporated within such fiber mats and their release can be adjusted by the material and dimensions of the individual fibers. The review gives a comprehensive overview about the current state of electrospun fibers for therapeutic application on skin wounds. Different materials as well as fabrication techniques are introduced including approaches for incorporation of drugs into or drug attachment onto the fiber surface. Against the background of wound pathophysiology and established therapy approaches, the therapeutic potential of electrospun fiber systems is discussed. A specific focus is set on interactions of fibers with skin cells/tissues as well as wound pathogens and strategies to modify and control them as key aspects for developing effective wound therapeutics. Further, advantages and limitations of controlled drug delivery from fiber mats to skin wounds are discussed and a future perspective is provided. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Regulation of electron transfer processes affects phototrophic mat structure and activity

    Science.gov (United States)

    Ha, Phuc T.; Renslow, Ryan S.; Atci, Erhan; Reardon, Patrick N.; Lindemann, Stephen R.; Fredrickson, James K.; Call, Douglas R.; Beyenal, Haluk

    2015-01-01

    Phototrophic microbial mats are among the most diverse ecosystems in nature. These systems undergo daily cycles in redox potential caused by variations in light energy input and metabolic interactions among the microbial species. In this work, solid electrodes with controlled potentials were placed under mats to study the electron transfer processes between the electrode and the microbial mat. The phototrophic microbial mat was harvested from Hot Lake, a hypersaline, epsomitic lake located near Oroville (Washington, USA). We operated two reactors: graphite electrodes were polarized at potentials of -700 mVAg/AgCl [cathodic (CAT) mat system] and +300 mVAg/AgCl [anodic (AN) mat system] and the electron transfer rates between the electrode and mat were monitored. We observed a diel cycle of electron transfer rates for both AN and CAT mat systems. Interestingly, the CAT mats generated the highest reducing current at the same time points that the AN mats showed the highest oxidizing current. To characterize the physicochemical factors influencing electron transfer processes, we measured depth profiles of dissolved oxygen (DO) and sulfide in the mats using microelectrodes. We further demonstrated that the mat-to-electrode and electrode-to-mat electron transfer rates were light- and temperature-dependent. Using nuclear magnetic resonance (NMR) imaging, we determined that the electrode potential regulated the diffusivity and porosity of the microbial mats. Both porosity and diffusivity were higher in the CAT mats than in the AN mats. We also used NMR spectroscopy for high-resolution quantitative metabolite analysis and found that the CAT mats had significantly higher concentrations of osmoprotectants such as betaine and trehalose. Subsequently, we performed amplicon sequencing across the V4 region of the 16S rRNA gene of incubated mats to understand the impact of electrode potential on microbial community structure. These data suggested that variation in the

  2. Regulation of electron transfer processes affects phototrophic mat structure and activity

    Directory of Open Access Journals (Sweden)

    Haluk eBeyenal

    2015-09-01

    Full Text Available Phototrophic microbial mats are among the most diverse ecosystems in nature. These systems undergo daily cycles in redox potential caused by variations in light energy input and metabolic interactions among the microbial species. In this work, solid electrodes with controlled potentials were placed under mats to study the electron transfer processes between the electrode and the microbial mat. The phototrophic microbial mat was harvested from Hot Lake, a hypersaline, epsomitic lake located near Oroville (Washington, USA. We operated two reactors: graphite electrodes were polarized at potentials of -700 mVAg/AgCl (cathodic mat system and +300 mVAg/AgCl (anodic mat system and the electron transfer rates between the electrode and mat were monitored. We observed a diel cycle of electron transfer rates for both anodic and cathodic mat systems. Interestingly, the cathodic mats generated the highest reducing current at the same time points that the anodic mats showed the highest oxidizing current. To characterize the physicochemical factors influencing electron transfer processes, we measured depth profiles of dissolved oxygen and sulfide in the mats using microelectrodes. We further demonstrated that the mat-to-electrode and electrode-to-mat electron transfer rates were light- and temperature-dependent. Using nuclear magnetic resonance (NMR imaging, we determined that the electrode potential regulated the diffusivity and porosity of the microbial mats. Both porosity and diffusivity were higher in the cathodic mats than in the anodic mats. We also used NMR spectroscopy for high-resolution quantitative metabolite analysis and found that the cathodic mats had significantly higher concentrations of osmoprotectants such as betaine and trehalose. Subsequently, we performed amplicon sequencing across the V4 region of the 16S rRNA gene of incubated mats to understand the impact of electrode potential on microbial community structure. These data suggested that

  3. Regulation of electron transfer processes affects phototrophic mat structure and activity.

    Science.gov (United States)

    Ha, Phuc T; Renslow, Ryan S; Atci, Erhan; Reardon, Patrick N; Lindemann, Stephen R; Fredrickson, James K; Call, Douglas R; Beyenal, Haluk

    2015-01-01

    Phototrophic microbial mats are among the most diverse ecosystems in nature. These systems undergo daily cycles in redox potential caused by variations in light energy input and metabolic interactions among the microbial species. In this work, solid electrodes with controlled potentials were placed under mats to study the electron transfer processes between the electrode and the microbial mat. The phototrophic microbial mat was harvested from Hot Lake, a hypersaline, epsomitic lake located near Oroville (Washington, USA). We operated two reactors: graphite electrodes were polarized at potentials of -700 mVAg/AgCl [cathodic (CAT) mat system] and +300 mVAg/AgCl [anodic (AN) mat system] and the electron transfer rates between the electrode and mat were monitored. We observed a diel cycle of electron transfer rates for both AN and CAT mat systems. Interestingly, the CAT mats generated the highest reducing current at the same time points that the AN mats showed the highest oxidizing current. To characterize the physicochemical factors influencing electron transfer processes, we measured depth profiles of dissolved oxygen (DO) and sulfide in the mats using microelectrodes. We further demonstrated that the mat-to-electrode and electrode-to-mat electron transfer rates were light- and temperature-dependent. Using nuclear magnetic resonance (NMR) imaging, we determined that the electrode potential regulated the diffusivity and porosity of the microbial mats. Both porosity and diffusivity were higher in the CAT mats than in the AN mats. We also used NMR spectroscopy for high-resolution quantitative metabolite analysis and found that the CAT mats had significantly higher concentrations of osmoprotectants such as betaine and trehalose. Subsequently, we performed amplicon sequencing across the V4 region of the 16S rRNA gene of incubated mats to understand the impact of electrode potential on microbial community structure. These data suggested that variation in the

  4. Recombinant Gelatin Microspheres : Novel Formulations for Tissue Repair?

    NARCIS (Netherlands)

    Tuin, Annemarie; Kluijtmans, Sebastiaan G.; Bouwstra, Jan B.; Harmsen, Martin C.; Van Luyn, Marja J. A.

    Microspheres (MSs) can function as multifunctional scaffolds in different approaches of tissue repair (TR), as a filler, a slow-release depot for growth factors, or a delivery vehicle for cells. Natural cell adhesion-supporting extracellular matrix components like gelatin are good materials for

  5. Periodontal tissue regeneration with PRP incorporated gelatin hydrogel sponges.

    Science.gov (United States)

    Nakajima, Dai; Tabata, Yasuhiko; Sato, Soh

    2015-10-20

    Gelatin hydrogels have been designed and prepared for the controlled release of the transforming growth factor (TGF-b1) and the platelet-derived growth factor (PDGF-BB). PRP (Platelet rich plasma) contains many growth factors including the PDGF and TGF-b1. The objective of this study was to evaluate the regeneration of periodontal tissue following the controlled release of growth factors in PRP. For the periodontal ligament cells and osteoblast, PRP of different concentrations was added. The assessment of DNA, mitochondrial activity and ALP activity were measured. To evaluate the TGF-β1 release from PRP incorporated gelatin sponge, amounts of TGF-β1 in each supernatant sample were determined by the ELISA. Transplantation experiments to prepare a bone defect in a rat alveolar bone were an implanted gelatin sponge incorporated with different concentration PRP. In DNA assay and MTT assay, after the addition of PRP to the periodontal ligament cells and osteoblast, the cell count and mitochondrial activity had increased the most in the group with the addition of 5  ×  PRP. In the ALP assay, after the addition of PRP to the periodontal ligament cells, the cell activity had increased the most in the group with the addition of 3  ×  PRP. In the transplantation, the size of the bone regenerated in the defect with 3  ×  PRP incorporated gelatin sponge was larger than that of the other group.

  6. Rheological evaluation of the irradiated pectin/gelatin mixed systems

    International Nuclear Information System (INIS)

    Inamura, Patricia Y.; Mastro, Nelida L. del

    2011-01-01

    The main biopolymers used in the edible films production are polysaccharides and proteins. Pectin is a heterosaccharidic polymer derived from the vegetal cell wall. Gelatin is a heterogeneous mixture of water-soluble proteins of high average molecular mass derived by hydrolytic action from animal collagen. The aim of this research was to evaluate the effect of ionizing radiation on either the biopolymers alone or on the mixed systems prepared with high-and low-methoxyl pectin and gelatin in solution and mixed gel. The results showed that gelatin viscosity remained almost unaffected by the irradiation with doses from 1 to 15 kGy, with a slight increase at 3 kGy. On the other hand, there was a sharp decrease of viscosity values of all pectin solutions upon irradiation, being this behavior predominant when both polysaccharides and proteins were present in a mixed system. The gel hardness and gel brittleness of the gelatin were affected by the increase of radiation dose. (author)

  7. Irradiated gelatin-potato starch blends: evaluation of physicochemical properties

    International Nuclear Information System (INIS)

    Inamura, Patricia Y.; Regis, Wellington; Mastro, Nelida L.

    2015-01-01

    Macromolecular polysaccharides of large chains as starch can interlace with gelatin modifying their mechanical resistance. In this work, biodegradable bovine gelatin-potato starch blends films were developed using glycerol as plasticizer. Three formulations of gelatin/starch proportions (w/w) were used (1:0; 3:1; 1:1) and casting was the chosen method. The dried samples were then submitted to ionizing radiation coming from an electron beam (EB) accelerator with doses of 20 and 40 kGy, at room temperature, in the presence of air. Mechanical properties such as puncture strength and elongation at break were measured. Color measurements, water absorption, moisture, and film solubility were assessed. The results showed that starch addition to films based on gelatin as well as irradiation affected physical and structural properties of the films. Although the increase of starch content in the mixture led to decrease of the puncture force even in samples irradiated with the higher dose, there was a decrease of water absorption of films with the increase of the dose, and also by the higher starch content. Samples irradiated at 20 kGy presented higher moisture and film solubility. The methodology developed in this paper can be applied to other composite systems to establish the best protein:starch ratio, and the contribution of the radiation crosslinking in each specific case. (author)

  8. Periodontal tissue regeneration with PRP incorporated gelatin hydrogel sponges

    International Nuclear Information System (INIS)

    Nakajima, Dai; Tabata, Yasuhiko; Sato, Soh

    2015-01-01

    Gelatin hydrogels have been designed and prepared for the controlled release of the transforming growth factor (TGF-b1) and the platelet-derived growth factor (PDGF-BB). PRP (Platelet rich plasma) contains many growth factors including the PDGF and TGF-b1. The objective of this study was to evaluate the regeneration of periodontal tissue following the controlled release of growth factors in PRP. For the periodontal ligament cells and osteoblast, PRP of different concentrations was added. The assessment of DNA, mitochondrial activity and ALP activity were measured. To evaluate the TGF-β1 release from PRP incorporated gelatin sponge, amounts of TGF-β1 in each supernatant sample were determined by the ELISA. Transplantation experiments to prepare a bone defect in a rat alveolar bone were an implanted gelatin sponge incorporated with different concentration PRP. In DNA assay and MTT assay, after the addition of PRP to the periodontal ligament cells and osteoblast, the cell count and mitochondrial activity had increased the most in the group with the addition of 5  ×  PRP. In the ALP assay, after the addition of PRP to the periodontal ligament cells, the cell activity had increased the most in the group with the addition of 3  ×  PRP. In the transplantation, the size of the bone regenerated in the defect with 3  ×  PRP incorporated gelatin sponge was larger than that of the other group. (paper)

  9. Preparation of Astaxanthin Nanodispersions Using Gelatin-Based Stabilizer Systems

    Directory of Open Access Journals (Sweden)

    Navideh Anarjan

    2014-09-01

    Full Text Available The incorporation of lipophilic nutrients, such as astaxanthin (a fat soluble carotenoid in nanodispersion systems can either increase the water solubility, stability and bioavailability or widen their applications in aqueous food and pharmaceutical formulations. In this research, gelatin and its combinations with sucrose oleate as a small molecular emulsifier, sodium caseinate (SC as a protein and gum Arabic as a polysaccharide were used as stabilizer systems in the formation of astaxanthin nanodispersions via an emulsification-evaporation process. The results indicated that the addition of SC to gelatin in the stabilizer system could increase the chemical stability of astaxanthin nanodispersions significantly, while using a mixture of gelatin and sucrose oleate as a stabilizer led to production of nanodispersions with the smallest particle size (121.4 ± 8.6 nm. It was also shown that a combination of gelatin and gum Arabic could produce optimal astaxanthin nanodispersions in terms of physical stability (minimum polydispersity index (PDI and maximum zeta-potential. This study demonstrated that the mixture of surface active compounds showed higher emulsifying and stabilizing functionality compared to using them individually in the preparation of astaxanthin nanodispersions.

  10. The use of gelatine in wound ballistics research.

    Science.gov (United States)

    Carr, D J; Stevenson, T; Mahoney, P F

    2018-04-25

    Blocks of gelatine are used in both lethality and survivability studies for broadly the same reason, i.e. comparison of ammunition effects using a material that it is assumed represents (some part of) the human body. The gelatine is used to visualise the temporary and permanent wound profiles; elements of which are recognised as providing a reasonable approximation to wounding in humans. One set of researchers aim to improve the lethality of the projectile, and the other to understand the effects of the projectile on the body to improve survivability. Research areas that use gelatine blocks are diverse and include ammunition designers, the medical and forensics communities and designers of ballistic protective equipment (including body armour). This paper aims to provide an overarching review of the use of gelatine for wound ballistics studies; it is not intended to provide an extensive review of wound ballistics as that already exists, e.g. Legal Med 23:21-29, 2016. Key messages are that test variables, projectile type (bullet, fragmentation), impact site on the body and intermediate layers (e.g. clothing, personal protective equipment (PPE)) can affect the resulting wound profiles.

  11. Cashew gum and gelatin blend for food packaging application

    Science.gov (United States)

    Cashew gum (CG) and gelatin (G) films were developed using the casting method and response surface methodology. The objective was produce packaging films from CG/G blends that exhibit effective barrier properties. A study of zeta potential versus pH was first carried out to determine the isoelectric...

  12. Lecithin, gelatin and hydrolyzed collagen orally disintegrating films: functional properties.

    Science.gov (United States)

    Borges, J G; Silva, A G; Cervi-Bitencourt, C M; Vanin, F M; Carvalho, R A

    2016-05-01

    Orally disintegrating films (ODFs) can transport natural active compounds such as ethanol extract of propolis (EEP). This paper aimed to investigate the effect of lecithin on different gelatin and hydrolyzed collagen (HC) polymeric matrices with addition of EEP. ODFs were prepared by casting technique and were characterized (color parameters, water content, mechanical properties, microstructure, disintegration time (DT), infrared spectroscopy (FTIR), contact angle (CA), swelling degree and total phenolic content). The mechanical properties were influenced by HC. The microstructure demonstrated increased porosity and roughness in films with EEP, and the addition of lecithin resulted in an increase in the number of pores. Lecithin-gelatin and lecithin-EEP-gelatin interactions were observed by FTIR. The addition of HC and EEP reduced the DT and CA, and HC and lecithin reduced the swelling capacity. However, the swelling capacity was not affected by presence of EEP. The addition of lecithin to gelatin and HC ODFs may improve the incorporation and the oral transport of active compounds such as EEP. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Gelatin as a carrier system for delivery of polyphenols compounds

    Directory of Open Access Journals (Sweden)

    Jovanović Aleksandra

    2017-01-01

    Full Text Available In the present study, the influence of different encapsulation techniques (lyophilization and spray drying on gelatin, as a carrier system for delivery of polyphenols compounds, on wild thyme extracts and on encapsulated extracts was investigated. FTIR analyses has shown the presence of carbohydrates, polysaccharides, polyphenols, flavonoids, monoterpenes and carboxylates in the dried extracts, while FTIR spectrum of the encapsulated extracts has shown almost exclusively gelatin-based stripes, indicating the efficient encapsulation of the active ingredients of the extracts and therefore their protection. Scanning electron microscopy has shown that the lyophilization process produced irregularly shaped particles, while spray drying formed spherical and pseudo-spherical particles with rough surface. Using the method of diffraction of laser light, it has been found that spray dried encapsulate possessed significantly lower particle size and significantly better uniformity in comparison to the lyophilized sample. According to the results obtained in differential scanning calorimetry, endothermic peak of lyophilized gelatin encapsulate appeared at higher temperature, thus it can be concluded that lyophilized sample was more thermostable than spray dried parallel. Additionally, the values of enthalpy of gelatin encapsulates were significantly higher compared to pure extracts, which confirmed the presence of stabilizing interactions between the encapsulated components and a carrier.

  14. Irradiated gelatin-potato starch blends: evaluation of physicochemical properties

    Energy Technology Data Exchange (ETDEWEB)

    Inamura, Patricia Y.; Regis, Wellington; Mastro, Nelida L., E-mail: nlmastro@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Macromolecular polysaccharides of large chains as starch can interlace with gelatin modifying their mechanical resistance. In this work, biodegradable bovine gelatin-potato starch blends films were developed using glycerol as plasticizer. Three formulations of gelatin/starch proportions (w/w) were used (1:0; 3:1; 1:1) and casting was the chosen method. The dried samples were then submitted to ionizing radiation coming from an electron beam (EB) accelerator with doses of 20 and 40 kGy, at room temperature, in the presence of air. Mechanical properties such as puncture strength and elongation at break were measured. Color measurements, water absorption, moisture, and film solubility were assessed. The results showed that starch addition to films based on gelatin as well as irradiation affected physical and structural properties of the films. Although the increase of starch content in the mixture led to decrease of the puncture force even in samples irradiated with the higher dose, there was a decrease of water absorption of films with the increase of the dose, and also by the higher starch content. Samples irradiated at 20 kGy presented higher moisture and film solubility. The methodology developed in this paper can be applied to other composite systems to establish the best protein:starch ratio, and the contribution of the radiation crosslinking in each specific case. (author)

  15. Gelatine-assisted synthesis of magnetite nanoparticles for magnetic hyperthermia

    Energy Technology Data Exchange (ETDEWEB)

    Alves, André F.; Mendo, Sofia G. [Universidade de Lisboa, Centro de Química e Bioquímica, Faculdade de Ciências (Portugal); Ferreira, Liliana P. [Universidade de Lisboa, Biosystems and Integrative Sciences Institute, Faculdade de Ciências (Portugal); Mendonça, Maria Helena [Universidade de Lisboa, Centro de Química e Bioquímica, Faculdade de Ciências (Portugal); Ferreira, Paula [University of Aveiro, Department of Materials and Ceramic Engineering, CICECO - Aveiro Institute of Materials (Portugal); Godinho, Margarida; Cruz, Maria Margarida [Universidade de Lisboa, Biosystems and Integrative Sciences Institute, Faculdade de Ciências (Portugal); Carvalho, Maria Deus, E-mail: mdcarvalho@ciencias.ulisboa.pt [Universidade de Lisboa, Centro de Química e Bioquímica, Faculdade de Ciências (Portugal)

    2016-01-15

    Magnetite nanoparticles were synthesized by the co-precipitation method exploring the use of gelatine and agar as additives. For comparison, magnetite nanoparticles were also prepared by standard co-precipitation, by co-precipitation with the addition of a surfactant (sodium dodecyl sulphate) and by the thermal decomposition method. The structure and morphology of the synthesized nanoparticles were investigated by powder X-ray diffraction and transmission electron microscopy. Their magnetic properties were studied by SQUID magnetometry and {sup 57}Fe Mössbauer spectroscopy. The nanoparticles potential for applications in magnetic hyperthermia was evaluated through heating efficiency under alternating magnetic field. The results show that all synthesis methods produce Fe{sub 3−x}O{sub 4} nanoparticles with similar sizes. The nanoparticles synthesized in the gelatine medium display the narrowest particle size distribution, the lowest oxidation degree, one of the highest saturation magnetization values and the best hyperthermia efficiency, proving that this gelatine-assisted synthesis is an efficient, environmental friendly, and low-cost method to produce magnetite nanoparticles. Graphical Abstract: A new gelatine-assisted method is an efficient and low-cost way to synthesize magnetite nanoparticles with enhanced magnetic hyperthermia.

  16. Formulation and Evaluation of Microspheres Based on Gelatin ...

    African Journals Online (AJOL)

    Formulation and Evaluation of Microspheres Based on Gelatin-Mucin Admixtures for the Rectal Delivery of Cefuroxime Sodium. K C Ofokansi, M U Adikwu. Abstract. Purpose: Swellable microspheres based on polymers or their admixtures are frequently employed as drug delivery systems to achieve a controlled release ...

  17. Dichromated gelatin and its importance for optical hologram recording

    Czech Academy of Sciences Publication Activity Database

    Šmíd, Petr; Hiklová, H.; Keprt, Jiří

    2004-01-01

    Roč. 54, č. 12 (2004), s. 1461-1472 ISSN 0011-4626 R&D Projects: GA MŠk(CZ) LN00A015 Keywords : dichromated gelatin * holography * volume program Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.292, year: 2004

  18. Durability-Based Design Criteria for a Chopped-Glass-Fiber Automotive Structural Composite; TOPICAL

    International Nuclear Information System (INIS)

    Battiste, R.L.; Corum, J.M.; Ren, W.; Ruggles, M.B.

    1999-01-01

    This report provides recommended durability-based design criteria for a chopped-glass-fiber reinforced polymeric composite for automotive structural applications. The criteria closely follow the framework of an earlier criteria document for a continuous-strand-mat (CSM) glass-fiber reference composite. Together these design criteria demonstrate a framework that can be adapted for future random-glass-fiber composites for automotive structural applications

  19. Gold nanorod-incorporated gelatin-based conductive hydrogels for engineering cardiac tissue constructs.

    Science.gov (United States)

    Navaei, Ali; Saini, Harpinder; Christenson, Wayne; Sullivan, Ryan Tanner; Ros, Robert; Nikkhah, Mehdi

    2016-09-01

    The development of advanced biomaterials is a crucial step to enhance the efficacy of tissue engineering strategies for treatment of myocardial infarction. Specific characteristics of biomaterials including electrical conductivity, mechanical robustness and structural integrity need to be further enhanced to promote the functionalities of cardiac cells. In this work, we fabricated UV-crosslinkable gold nanorod (GNR)-incorporated gelatin methacrylate (GelMA) hybrid hydrogels with enhanced material and biological properties for cardiac tissue engineering. Embedded GNRs promoted electrical conductivity and mechanical stiffness of the hydrogel matrix. Cardiomyocytes seeded on GelMA-GNR hybrid hydrogels exhibited excellent cell retention, viability, and metabolic activity. The increased cell adhesion resulted in abundance of locally organized F-actin fibers, leading to the formation of an integrated tissue layer on the GNR-embedded hydrogels. Immunostained images of integrin β-1 confirmed improved cell-matrix interaction on the hybrid hydrogels. Notably, homogeneous distribution of cardiac specific markers (sarcomeric α-actinin and connexin 43), were observed on GelMA-GNR hydrogels as a function of GNRs concentration. Furthermore, the GelMA-GNR hybrids supported synchronous tissue-level beating of cardiomyocytes. Similar observations were also noted by, calcium transient assay that demonstrated the rhythmic contraction of the cardiomyocytes on GelMA-GNR hydrogels as compared to pure GelMA. Thus, the findings of this study clearly demonstrated that functional cardiac patches with superior electrical and mechanical properties can be developed using nanoengineered GelMA-GNR hybrid hydrogels. In this work, we developed gold nanorod (GNR) incorporated gelatin-based hydrogels with suitable electrical conductivity and mechanical stiffness for engineering functional cardiac tissue constructs (e.g. cardiac patches). The synthesized conductive hybrid hydrogels properly

  20. Effects of Pressure-shift Freezing on the Structural and Physical Properties of Gelatin Hydrogel Matrices

    Science.gov (United States)

    Kim, Byeongsoo; Gil, Hyung Bae; Min, Sang-Gi; Lee, Si-Kyung; Choi, Mi-Jung

    2014-01-01

    This study investigates the effects of the gelatin concentration (10-40%, w/v), freezing temperatures (from -20℃ to -50℃) and freezing methods on the structural and physical properties of gelatin matrices. To freeze gelatin, the pressure-shift freezing (PSF) is being applied at 0.1 (under atmospheric control), 50 and 100 MPa, respectively. The freezing point of gelatin solutions decrease with increasing gelatin concentrations, from -0.2℃ (10% gelatin) to -6.7℃ (40% gelatin), while the extent of supercooling did not show any specific trends. The rheological properties of the gelatin indicate that both the storage (G') and loss (G") moduli were steady in the strain amplitude range of 0.1-10%. To characterize gelatin matrices formed by the various freezing methods, the ice crystal sizes which were being determined by the scanning electron microscopy (SEM) are affected by the gelatin concentrations. The ice crystal sizes are affected by gelatin concentrations and freezing temperature, while the size distributions of ice crystals depend on the freezing methods. Smaller ice crystals are being formed with PSF rather than under the atmospheric control where the freezing temperature is above -40℃. Thus, the results of this study indicate that the PSF processing at a very low freezing temperature (-50℃) offers a potential advantage over commercial atmospheric freezing points for the formation of small ice crystals. PMID:26760743

  1. Gelatin controversies in food, pharmaceuticals, and personal care products: Authentication methods, current status, and future challenges.

    Science.gov (United States)

    Ali, Eaqub; Sultana, Sharmin; Hamid, Sharifah Bee Abd; Hossain, Motalib; Yehya, Wageeh A; Kader, Abdul; Bhargava, Suresh K

    2018-06-13

    Gelatin is a highly purified animal protein of pig, cow, and fish origins and is extensively used in food, pharmaceuticals, and personal care products. However, the acceptability of gelatin products greatly depends on the animal sources of the gelatin. Porcine and bovine gelatins have attractive features but limited acceptance because of religious prohibitions and potential zoonotic threats, whereas fish gelatin is welcomed in all religions and cultures. Thus, source authentication is a must for gelatin products but it is greatly challenging due to the breakdown of both protein and DNA biomarkers in processed gelatins. Therefore, several methods have been proposed for gelatin identification, but a comprehensive and systematic document that includes all of the techniques does not exist. This up-to-date review addresses this research gap and presents, in an accessible format, the major gelatin source authentication techniques, which are primarily nucleic acid and protein based. Instead of presenting these methods in paragraph form which needs much attention in reading, the major methods are schematically depicted, and their comparative features are tabulated. Future technologies are forecasted, and challenges are outlined. Overall, this review paper has the merit to serve as a reference guide for the production and application of gelatin in academia and industry and will act as a platform for the development of improved methods for gelatin authentication.

  2. Fabrication and Physical Evaluation of Gelatin-Coated Carbonate Apatite Foam

    Directory of Open Access Journals (Sweden)

    Kanae Hara

    2016-08-01

    Full Text Available Carbonate apatite (CO3Ap foam has gained much attention in recent years because of its ability to rapidly replace bone. However, its mechanical strength is extremely low for clinical use. In this study, to understand the potential of gelatin-reinforced CO3Ap foam for bone replacement, CO3Ap foam was reinforced with gelatin and the resulting physical characteristics were evaluated. The mechanical strength increased significantly with the gelatin reinforcement. The compressive strength of gelatin-free CO3Ap foam was 74 kPa whereas that of the gelatin-reinforced CO3Ap foam, fabricated using 30 mass % gelatin solution, was approximately 3 MPa. Heat treatment for crosslinking gelatin had little effect on the mechanical strength of the foam. The gelatin-reinforced foam did not maintain its shape when immersed in a saline solution as this promoted swelling of the gelatin; however, in the same conditions, the heat-treated gelatin-reinforced foam proved to be stable. It is concluded, therefore, that heat treatment is the key to the fabrication of stable gelatin-reinforced CO3Ap foam.

  3. Characterization and application of zeolitic imidazolate framework-8@polyvinyl alcohol nanofibers mats prepared by electrospinning

    Science.gov (United States)

    Fan, Xiaoxiao; Yu, Linling; Li, Lianghao; Yang, Cao; Wen, Junjie; Ye, Xiaokun; Cheng, Jianhua; Hu, Yongyou

    2017-02-01

    In this study, Zeolitic imidazolate framework-8@polyvinyl alcohol (ZIF-8@PVA) nanofibers were creatively fabricated by electrospinning technique, and the nanofibers membranes were characterized by SEM, TEM, XRD, FTIR, TG, DSC, DTA, BET. Its thermal stability, mechanical property, water stability and adsorption nature were also performed. The optimized fabrication parameter of the ZIF-8@PVA was 10 wt% and the uniform diameters of the nanofibers has been obtained. In addition, the ZIF-8@PVA nanofibers displayed unique properties such as a water stable and flexible structure. The adsorption test for Congo red treatment revealed that the nanofibers had a great adsorption performance. The results indicated that the nonwoven fiber mats had a great potential as a new type of membrane adsorbents in wastewater purification. The possible mechanism of CR adsorption onto ZIF-8@PVA was researched.

  4. Effect of ageing on the calibration of ballistic gelatin.

    Science.gov (United States)

    Guey, Jason; Rodrigues, S; Pullen, A; Shaw, B; Kieser, D C

    2018-02-27

    Ballistic gelatin is commonly used as a validated surrogate for soft tissue during terminal ballistic testing. However, the effect of a delay between production and testing of a gelatin mould remains unknown. The aim of this study was to determine any potential effects of ageing on ballistic gelatin. Depth of penetration (DoP) of 4.5 mm spherical fragment simulating projectiles was ascertained using mixtures of 10%, 11.25% and 20% Type A 250 Bloom ballistic gelatin. Testing was performed daily for 5 days using velocities between 75 and 210 m/s. DoP at day 5 was statistically compared with day 1, and net mass change was recorded daily. No significant difference was found for DoP observed with time in any of the samples (P>0.05). Spearman correlation was excellent in all moulds. The moulds with known standard calibrations remained in calibration throughout the study period. Mass loss of less than 1% was noted in all samples. Mass loss was the only quantifiable measure of changes in the blocks with time, but did not correlate with any changes in DoP. This may provide reassurance when undertaking such testing that an inadvertent delay will not significantly alter the penetration properties of the mould. Future research is recommended to determine any potential effect on the mechanical properties of gelatin at higher velocity impacts and whether the calibration corresponds to an adequate simulation under such conditions. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  5. Effectiveness of a new gelatin sealant system for dural closure.

    Science.gov (United States)

    Kawai, Hisashi; Nakagawa, Ichiro; Nishimura, Fumihiko; Motoyama, Yasushi; Park, Young-Su; Nakamura, Mitsutoshi; Nakase, Hiroyuki; Suzuki, Shuko; Ikada, Yoshito

    2014-10-01

    Watertight dural closure is imperative after neurosurgical procedures because inadequately treated leakage of cerebrospinal fluid (CSF) can have serious consequences. In this study, the authors test the use of a new gelatin glue as a dural sealant in in vitro and in vivo canine models of transdural CSF leakage. The in vitro model was sutured semicircles of canine dura mater and artificial dural substitute. The sutures were sealed with gelatin glue (n  =  20), fibrin glue (n  =  20), or a polyethylene glycol (PEG)-based hydrogel sealant (n  =  20). Each sample was set in a device to measure water pressure, and pressure was increased until leakage occurred. Bonding strength was subjectively evaluated. The in vivo model was dogs who underwent dural excision and received either no sealant (control group; n  =  5) or gelatin glue sealant (n  =  5) before dural closure. Twenty-eight days post-surgery, the maximum intracranial pressure was measured at the cisterna magna using Valsalva maneuver and tissue adhesion was evaluated. The water pressure at which leakage occurred in the in vitro model was higher with gelatin glue (76·5 ± 39·8 mmHg) than with fibrin glue (38·3 ± 27·4 mmHg, P control group (13·8 ± 4·0 mmHg, P control group (P  =  0·005). The new gelatin glue provides an effective watertight closure when used as an adjunct to sutured dural repair.

  6. Gelatin functionalised porous titanium alloy implants for orthopaedic applications

    Energy Technology Data Exchange (ETDEWEB)

    Vanderleyden, E. [Polymer Chemistry and Biomaterials Research Group, Department of Organic Chemistry, University of Ghent, Krijgslaan 281 S4, 9000 Ghent (Belgium); Van Bael, S. [Prometheus, Division of Skeletal Tissue Engineering, Katholieke Universiteit Leuven, O and N 1, Herestraat 49, Box 813, 3000 Leuven (Belgium); Department of Mechanical Engineering, Division of Production Engineering, Machine Design and Automation, Katholieke Universiteit Leuven, Celestijnenlaan 300b, 3001 Leuven (Belgium); Department of Mechanical Engineering, Division of Biomechanics and Engineering Design, Katholieke Universiteit Leuven, Celestijnenlaan 300c, Box 2419, 3001 Heverlee (Belgium); Chai, Y.C. [Prometheus, Division of Skeletal Tissue Engineering, Katholieke Universiteit Leuven, O and N 1, Herestraat 49, Box 813, 3000 Leuven (Belgium); Tissue Engineering Laboratory, Skeletal Biology and Engineering Research Center, Katholieke Universiteit Leuven, O and N 1, Herestraat 49, Box 813, 3000 Leuven (Belgium); Kruth, J.-P. [Department of Mechanical Engineering, Division of Production Engineering, Machine Design and Automation, Katholieke Universiteit Leuven, Celestijnenlaan 300b, 3001 Leuven (Belgium); Schrooten, J. [Prometheus, Division of Skeletal Tissue Engineering, Katholieke Universiteit Leuven, O and N 1, Herestraat 49, Box 813, 3000 Leuven (Belgium); Department of Metallurgy and Materials Engineering, Katholieke Universiteit Leuven, Kasteelpark Arenberg 44, Bus 2450, 3001 Leuven (Belgium); Dubruel, P., E-mail: pbmugent@gmail.com [Polymer Chemistry and Biomaterials Research Group, Department of Organic Chemistry, University of Ghent, Krijgslaan 281 S4, 9000 Ghent (Belgium)

    2014-09-01

    In the present work, we studied the immobilisation of the biopolymer gelatin onto the surface of three dimensional (3D) regular Ti6Al4V porous implants to improve their surface bio-activity. The successful immobilisation of the gelatin coating was made possible by a polydopamine interlayer, a polymer coating inspired by the adhesive nature of mussels. The presence of both coatings was first optimised on two dimensional titanium (2D Ti) substrates and confirmed by different techniques including X-ray photelectron spectroscopy, contact angle measurements, atomic force microscopy and fluorescence microscopy. Results showed homogeneous coatings that are stable for at least 24 h in phosphate buffer at 37 °C. In a next step, the coating procedure was successfully transferred to 3D Ti6Al4V porous implants, which indicates the versatility of the applied coating procedure with regard to complex surface morphologies. Furthermore, the bio-activity of these stable gelatin coatings was enhanced by applying a third and final coating using the cell-attractive protein fibronectin. The reproducible immobilisation process allowed for a controlled biomolecule presentation to the surrounding tissue. This newly developed coating procedure outperformed the previously reported silanisation procedure for immobilising gelatin. In vitro cell adhesion and culture studies with human periosteum-derived cells showed that the investigated coatings did not compromise the biocompatible nature of Ti6Al4V porous implants, but no distinct biological differences between the coatings were found. - Highlights: • Ti6Al4V porous implants were produced by selective laser melting. • A procedure to obtain a stable gelatin coating was developed. • Successful transfer of the coating procedure from 2D to 3D Ti6Al4V porous implants. • In vitro cell studies showed that the developed coatings supported cell growth.

  7. Utilização de fibras (epicarpo de babaçu como matéria-prima alternativa na produção de chapas de madeira aglomerada Use of babaçu staple fiber as alternative raw material for panel production

    Directory of Open Access Journals (Sweden)

    Ademi Moraes Lima

    2006-08-01

    Full Text Available O objetivo deste trabalho foi avaliar a utilização de fibras (epicarpo de babaçu (Orbignya spp em combinação com partículas de Pinus elliottii em diferentes proporções na confecção de chapas de madeira aglomerada, bem como avaliar o efeito de dois teores de adesivo à base de uréia-formaldeído. As chapas foram prensadas a 160 ºC, utilizando-se dois níveis de resinas (6 e 8%, base peso seco de partículas e tempo de prensagem de 10 min, obtendo-se oito tratamentos. Para cada tratamento foram feitas três repetições, totalizando 24 chapas, com densidade nominal de 0,70 g/cm³. As propriedades avaliadas foram: flexão estática - módulo de ruptura (MOR e módulo de elasticidade (MOE; tração perpendicular-ligação interna (LI; estabilidade dimensional - inchamento em espessura (IE 2 e 24 horas e absorção de água (AA 2 e 24 horas, de acordo com a norma ASTM D 1037-91. O aumento do teor de fibras de babaçu associado ao aumento no teor de adesivo contribuiu para a redução nos valores de inchamento em espessura e absorção de água. O aumento do teor de adesivo de 6 para 8% foi fundamental para a melhoria das propriedades inchamento em espessura, absorção em água, módulo de ruptura e módulo de elasticidade. Utilizando até 30% de fibras de babaçu na composição das chapas, os valores de MOR foram superiores aos estabelecidos pela CS 236-66.The objective of this work was to evaluate the use of babaçu (Orbignya spp fiber (epicarp in combination with particles of Pinus elliottii at different ratios in particleboard manufacturing, as well as evaluating the effect of different adhesive contents. The boards were pressed at 160 ºC, using two resin levels - 6% and 8% (particle dry weight basis and 10 min pressing time, totaling eight treatments, tree repetitions per treatment, totaling twenty four boards, with 0.70 g/cm³ nominal density. The evaluated properties were as follows: Static bending - modulus of rupture (MOR and

  8. Photosynthetic Microbial Mats are Exemplary Sources of Diverse Biosignatures (Invited)

    Science.gov (United States)

    Des Marais, D. J.; Jahnke, L. L.

    2013-12-01

    Marine cyanobacterial microbial mats are widespread, compact, self-contained ecosystems that create diverse biosignatures and have an ancient fossil record. Within the mats, oxygenic photosynthesis provides organic substrates and O2 to the community. Both the absorption and scattering of light change the intensity and spectral composition of incident radiation as it penetrates a mat. Some phototrophs utilize infrared light near the base of the photic zone. A mat's upper layers can become highly reduced and sulfidic at night. Counteracting gradients of O2 and sulfide shape the chemical environment and provide daily-contrasting microenvironments separated on a scale of a few mm. Radiation hazards (UV, etc.), O2 and sulfide toxicity elicit motility and other physiological responses. This combination of benefits and hazards of light, O2 and sulfide promotes the allocation of various essential mat processes between light and dark periods and to various depths in the mat. Associated nonphotosynthetic communities, including anaerobes, strongly influence many of the ecosystem's overall characteristics, and their processes affect any biosignatures that enter the fossil record. A biosignature is an object, substance and/or pattern whose origin specifically requires a biological agent. The value of a biosignature depends not only on the probability of life creating it, but also on the improbability of nonbiological processes producing it. Microbial mats create biosignatures that identify particular groups of organisms and also reveal attributes of the mat ecosystem. For example, branched hydrocarbons and pigments can be diagnostic of cyanobacteria and other phototrophic bacteria, and isoprenoids can indicate particular groups of archea. Assemblages of lipid biosignatures change with depth due to changes in microbial populations and diagenetic transformations of organic matter. The 13C/12C values of organic matter and carbonates reflect isotopic discrimination by particular

  9. Preparation and characterization of hydroxyapatite/gelatin composite membranes for immunoisolation

    Science.gov (United States)

    Chen, Jyh-Ping; Chang, Feng-Nian

    2012-12-01

    Composite membranes are fabricated from hydroxyapatite (HAP) and gelatin for immunoisolation of cells. The films were fabricated by crosslinking 5 wt%, 10 wt%, and 20 wt% gelatin with 1 wt% glutaraldehyde (GA) in the presence of HAP. Fourier transform infrared spectroscopy analysis confirms imide bond formation between GA and gelatin, while the crystal structure of HAP powder remains unchanged from X-ray diffraction analysis. The degree of crosslinking depends on crosslinking time and gelatin concentration. For 5% and 10% gelatin, the degree of crosslinking levels off at 90% within 48 h. From scanning electron microscopy micrographs, the microstructure of the composite membrane depends on the amount of gelatin used in the crosslinking reaction. The mechanical strength of the composite membrane could be enhanced by increasing the gelatin concentration. BET analysis indicates that pore size of the micropores on the surface HAP/gelatin agglomerates decreases with increasing gelatin concentration. However, the macropore, through which diffusion of molecules occurs, is larger at higher gelatin concentrations. The permeability coefficients of different molecules through a HAP/gelatin composite membrane increase with increasing gelatin concentration and is inversely correlated with the molecular weight of the molecule. For immunoisolation of cells, the diffusion of large molecules stimulated by the immune system can be rejected by a chamber constructed from the HAP/gelatin membrane. Insulinoma cells were encapsulated in alginate-poly-L-lysine-alginate microcapsules and enclosed in a HAP/gelatin chamber. The chamber did not impair the viability and function of insulinoma cells and cells can secrete insulin in response to glucose concentration change. The chamber is therefore useful for the physiologically controlled secretion of insulin in response to the blood glucose level. Intraperitoneal transplantation of the chamber into streptozotocin-induced diabetic SD rats could

  10. Two-step activation of meiosis by the mat1 locus in Schizosaccharomyces pombe

    DEFF Research Database (Denmark)

    Willer, M; Hoffmann, Ulla-Lisbeth; Styrkársdóttir, U

    1995-01-01

    in which the mat1 locus plays two roles in controlling meiosis. In the first instance, the mat1-Pc and mat1-Mc functions are required to produce the mating pheromones and receptors that allow the generation of a pheromone signal. This signal is required to induce the expression of mat1-Pm and mat1-Mm......The mat1 locus is a key regulator of both conjugation and meiosis in the fission yeast Schizosaccharomyces pombe. Two alternative DNA segments of this locus, mat1-P and mat1-M, specify the haploid cell types (Plus and Minus). Each segment includes two genes: mat1-P includes mat1-Pc and mat1-Pm....... This appears to be the major pheromone-dependent step in controlling meiosis since ectopic expression of these genes allows meiosis in the absence of mat1-Pc and mat1-Mc. The mat1-Pm and mat1-Mm products complete the initiation of meiosis by activating transcription of the mei3 gene....

  11. Mating-Type Genes and MAT Switching in Saccharomyces cerevisiae

    Science.gov (United States)

    Haber, James E.

    2012-01-01

    Mating type in Saccharomyces cerevisiae is determined by two nonhomologous alleles, MATa and MATα. These sequences encode regulators of the two different haploid mating types and of the diploids formed by their conjugation. Analysis of the MATa1, MATα1, and MATα2 alleles provided one of the earliest models of cell-type specification by transcriptional activators and repressors. Remarkably, homothallic yeast cells can switch their mating type as often as every generation by a highly choreographed, site-specific homologous recombination event that replaces one MAT allele with different DNA sequences encoding the opposite MAT allele. This replacement process involves the participation of two intact but unexpressed copies of mating-type information at the heterochromatic loci, HMLα and HMRa, which are located at opposite ends of the same chromosome-encoding MAT. The study of MAT switching has yielded important insights into the control of cell lineage, the silencing of gene expression, the formation of heterochromatin, and the regulation of accessibility of the donor sequences. Real-time analysis of MAT switching has provided the most detailed description of the molecular events that occur during the homologous recombinational repair of a programmed double-strand chromosome break. PMID:22555442

  12. Titanium diboride ceramic fiber composites for Hall-Heroult cells

    Science.gov (United States)

    Besmann, T.M.; Lowden, R.A.

    1990-05-29

    An improved cathode structure is described for Hall-Heroult cells for the electrolytic production of aluminum metal. This cathode structure is a preform fiber base material that is infiltrated with electrically conductive titanium diboride using chemical vapor infiltration techniques. The structure exhibits good fracture toughness, and is sufficiently resistant to attack by molten aluminum. Typically, the base can be made from a mat of high purity silicon carbide fibers. Other ceramic or carbon fibers that do not degrade at temperatures below about 1000 C can be used.

  13. Compression-recovery model of absorptive glass mat (AGM) separator guided by X-ray micro-computed tomography analysis

    Science.gov (United States)

    Kameswara Rao, P. V.; Rawal, Amit; Kumar, Vijay; Rajput, Krishn Gopal

    2017-10-01

    Absorptive glass mat (AGM) separators play a key role in enhancing the cycle life of the valve regulated lead acid (VRLA) batteries by maintaining the elastic characteristics under a defined level of compression force with the plates of the electrodes. Inevitably, there are inherent challenges to maintain the required level of compression characteristics of AGM separators during the charge and discharge of the battery. Herein, we report a three-dimensional (3D) analytical model for predicting the compression-recovery behavior of AGM separators by formulating a direct relationship with the constituent fiber and structural parameters. The analytical model of compression-recovery behavior of AGM separators has successfully included the fiber slippage criterion and internal friction losses. The presented work uses, for the first time, 3D data of fiber orientation from X-ray micro-computed tomography, for predicting the compression-recovery behavior of AGM separators. A comparison has been made between the theoretical and experimental results of compression-recovery behavior of AGM samples with defined fiber orientation characteristics. In general, the theory agreed reasonably well with the experimental results of AGM samples in both dry and wet states. Through theoretical modeling, fiber volume fraction was established as one of the key structural parameters that modulates the compression hysteresis of an AGM separator.

  14. Characteristics and Gel Properties of Gelatin from Goat Skin as Influenced by Alkaline-pretreatment Conditions

    Directory of Open Access Journals (Sweden)

    Sulaiman Mad-Ali

    2016-06-01

    Full Text Available Characteristics and properties of gelatin from goat skin pretreated with NaOH solutions (0.50 and 0.75 M for various times (1 to 4 days were investigated. All gelatins contained α-chains as the predominant component, followed by β-chain. Gelling and melting temperatures of those gelatins were 23.02°C to 24.16°C and 33.07°C to 34.51°C, respectively. Gel strength of gelatins increased as NaOH concentration and pretreatment time increased (p<0.05. Pretreatment for a longer time yielded gelatin with a decrease in L*-value but an increase in b*-value. Pretreatment of goat skin using 0.75 M NaOH for 2 days rendered the highest yield (15.95%, wet weight basis as well as high gel strength (222.42 g, which was higher than bovine gelatin (199.15 g. Gelatin obtained had the imino acid content of 226 residues/1,000 residues and the gelatin gel had a fine and ordered structure. Therefore, goat skin gelatin could be used as a potential replacer of commercial gelatin.

  15. Detection of growth factor binding to gelatin and heparin using a photonic crystal optical biosensor

    International Nuclear Information System (INIS)

    Morgan, Abby W.; Chan, Leo L.; Sendemir-Urkmez, Aylin; Cunningham, Brian T.; Jamison, Russell D.

    2010-01-01

    Drug-carrier interactions are important to protein controlled release systems to protect the protein from denaturation and ensure properly timed release. A novel photonic crystal biosensor was used to investigate a gelatin-protein controlled release system to determine the amount of protein bound to the carrier at physiological conditions. The Biomolecular Interaction Detection (BIND) system reflects a narrow band of wavelengths when white light is shone incident to the grating. As mass is deposited onto the surface, the peak wavelength value is shifted due to changes in the optical density of the biosensor. The BIND system was used to detect the binding of growth factors onto acidic gelatin, basic gelatin, and heparin on the sensor surface. Through a series of experiments, including functionalizing the sensor, adjusting the ionic strength of the solution, adjusting the substrate concentration, and minimizing non-specific signal, the adsorption of the gelatins and heparin on the sensor was enhanced. The binding interaction of recombinant human transforming growth factor (rhTGF)-β1 and bone morphogenetic protein (rhBMP)-2 with the two types of gelatin and heparin were investigated. The strength of the interaction between rhTGF-β1 and the substrates is in the following order: heparin > acidic gelatin > basic gelatin. RhBMP-2 bound to the substrates but with less intensity than TGF-β1: heparin > basic gelatin > acidic gelatin. This work provides support for the controlled release mechanism through degradation of the gelatin carrier.

  16. Align and random electrospun mat of PEDOT:PSS and PEDOT:PSS/RGO

    Science.gov (United States)

    Sarabi, Ghazale Asghari; Latifi, Masoud; Bagherzadeh, Roohollah

    2018-01-01

    In this research work we fabricated two ultrafine conductive nanofibrous layers to investigate the materilas composition and their properties for the preparation of supercapacitor materials application. In first layer, a polymer and a conductive polymer were used and second layer was a composition of polymer, conductive polymer and carbon-base material. In both cases align and randomized mat of conductive nanofibers were fabricated using electrospinning set up. Conductive poly (3,4-ethylenedioxythiophene)/ polystyrene sulfonate (PEDOT:PSS) nanofibers were electrospun by dissolving fiber-forming polymer and polyvinyl alcohol (PVA) in an aqueous dispersion of PEDOT:PSS. The effect of addition of reduced graphene oxide (RGO) was considered for nanocomposite layer. The ultrafine conductive polymer fibers and conductive nanocomposite fibrous materials were also fabricated using an electrospinning process. A fixed collector and a rotating drum were used for random and align nanofibers production, respectively. The resulted fibers were characterized and analyzed by SEM, FTIR and two-point probe conductivity test. The average diameter of nanofibers measured by ImageJ software indicated that the average fiber diameter for first layer was 100 nm and for nanocomposite layer was about 85 nm. The presence of PEDOT:PSS and RGO in the nanofibers was confirmed by FT-IR spectroscopy. The conductivity of align and random layers was characterized. The conductivity of PEDOT:PSS nanofibers showed higher enhancement by addition of RGO in aqueous dispersion. The obtained results showed that alignment of fibrous materials can be considered as an engineering tool for tuning the conductivity of fibrous materials for many different applications such as supercapacitors, conductive and transparent materials.

  17. Carbon storage potential in natural fiber composites

    Energy Technology Data Exchange (ETDEWEB)

    Pervaiz, Muhammad; Sain, Mohini M. [Faculty of Forestry, Advanced Wood Composite Group, Earth Science Center, University of Toronto, 33 Willcocks Street, Toronto, Ont. (Canada) M5S 3B3

    2003-11-01

    The environmental performance of hemp based natural fiber mat thermoplastic (NMT) has been evaluated in this study by quantifying carbon storage potential and CO{sub 2} emissions and comparing the results with commercially available glass fiber composites. Non-woven mats of hemp fiber and polypropylene matrix were used to make NMT samples by film-stacking method without using any binder aid. The results showed that hemp based NMT have compatible or even better strength properties as compared to conventional flax based thermoplastics. A value of 63 MPa for flexural strength is achieved at 64% fiber content by weight. Similarly, impact energy values (84-154 J/m) are also promising. The carbon sequestration and storage by hemp crop through photosynthesis is estimated by quantifying dry biomass of fibers based on one metric ton of NMT. A value of 325 kg carbon per metric ton of hemp based composite is estimated which can be stored by the product during its useful life. An extra 22% carbon storage can be achieved by increasing the compression ratio by 13% while maintaining same flexural strength. Further, net carbon sequestration by industrial hemp crop is estimated as 0.67 ton/h/year, which is compatible to all USA urban trees and very close to naturally, regenerated forests. A comparative life cycle analysis focused on non-renewable energy consumption of natural and glass fiber composites shows that a net saving of 50 000 MJ (3 ton CO{sub 2} emissions) per ton of thermoplastic can be achieved by replacing 30% glass fiber reinforcement with 65% hemp fiber. It is further estimated that 3.07 million ton CO{sub 2} emissions (4.3% of total USA industrial emissions) and 1.19 million m{sup 3} crude oil (1.0% of total Canadian oil consumption) can be saved by substituting 50% fiber glass plastics with natural fiber composites in North American auto applications. However, to compete with glass fiber effectively, further research is needed to improve natural fiber processing

  18. Critique de la dématérialisation

    OpenAIRE

    Robert , Pascal

    2004-01-01

    International audience; La notion de " dématérialisation " constitue actuellement l'une des pièces maîtresses de l'idéologie de la communication. Or, après enquête, nous constatons que la dématérialisation ne se rencontre ni dans les TIC ni dans les réseaux où se dévoilent en revanche un nouveau mode de matérialisation ainsi qu'un processus de virtualisation par changement d'échelle. Nous nous interrogeons donc sur la fonction sociale et politique que cette notion joue dans les discours qui l...

  19. Investigations of the mechanical properties of bi-layer and trilayer fiber reinforced composites

    Science.gov (United States)

    Jayakrishna, K.; Balasubramani, K.; Sultan, M. T. H.; Karthikeyan, S.

    2016-10-01

    Natural fibers are renewable raw materials with an environmental-friendly properties and they are recyclable. The mechanical properties of bi-layer and tri-layer thermoset polymer composites have been analyzed. The bi-layer composite consists of basalt and jute mats, while the tri-layer composite consists of basalt fiber, jute fiber and glass fiber mats. In both cases, the epoxy resin was used as the matrix and PTFE as a filler in the composites. The developed trilayer natural fiber composite can be used in various industrial applications such as automobile parts, construction and manufacturing. Furthermore, it also can be adopted in aircraft interior decoration and designed body parts. Flexural, impact, tensile, compression, shear and hardness tests, together with density measurement, were conducted to study the mechanical properties of both bi-layer and tri-layer composites. From the comparison, the tri-layer composite was found to perform in a better way in all tests.

  20. PENGARUH JENIS LARUTAN PERENDAM SERTA METODE PENGERINGAN TERHADAP SIFAT FISIK, KIMIA, DAN FUNGSIONAL GELATIN DARI KULIT CUCUT [The Influence of Solvent Variety and Drying Method on Physical, Chemical and Functional Characteristic of Shark Skin Gelatin

    Directory of Open Access Journals (Sweden)

    Made Astawan 1

    2003-04-01

    Full Text Available Gelatin is a denaturation product of collagen and has been widely utilized for foods, photography uses, medical materials, and culture materials for microorganisms. Recently, gelatin’s uses has expanded to new applications such as health foods. Gelatin of land animal origin such as bovine and porcine has been mainly used. However, gelatin with new properties is desired to develop expanded applications. In this research gelatin was made from shark skin. The shark skin collagen was distended by acetic acid solution (acid process and sodium hydroxide solution (alkali process, and gelatin was then extracted at 80oC of water. The extracted gelatin was dried by vacuum drying and freeze drying to obtain powder product. Shark gelatin produced by the combination of alkali and vacuum drying process (OVB gelatin had better qualities on yield, water content, gel strength, melting point, and emulsion stability as compared to the others. Sensory evaluation indicated that shark gelatin had lower values in color, odor, and performance as compared to the commercial gelatin of fish, pig and bovine (SKW Biosystem. However, as compared to the commercial gelatins, OVB gelatin had a similar values on gel strength (202 bloom and emulsion stability (100%, but higher values on viscosity (8 cP and pH (9.3. Those values indicated that ray skin gelatin can be used to substitute the commercial gelatin in some food industries

  1. Storage of yerba maté in controlled atmosphere

    Directory of Open Access Journals (Sweden)

    Sarah Lemos Cogo Prestes

    2014-04-01

    Full Text Available The aim of this study was to evaluate the effect of controlled atmosphere in the change of color, chlorophyll degradation and phenolic compounds concentration in yerba maté thickly ground (“cancheada” and thinly milled (“socada”. Yerba maté samples from the towns of Arvorezinha (RS - Brazil and São Mateus do Sul (PR - Brazil were stored in four levels of oxygen (1, 3, 6 and 20.9kPa of O2 and four levels of carbon dioxide (0, 3, 6 and 18kPa of CO2 and then were analyzed, after nine months of storage. According to the results, the O2 partial pressure reduction decreased the loss of green coloration, kept a higher content of chlorophylls and of total phenolic compounds. In relation to the different levels of CO2, a response as remarkable as O2 was not observed. The yerba maté that was thickly ground (“cancheada” presented a better storage potential than the one thinly milled (“socada” in the storage with O2 and with CO2. The 1kPa of O2 condition kept the yerba maté greener and with a higher content of chlorophylls and of total phenolic compounds after nine months of storage. The CO2 partial pressure kept the yerba maté coloration greener and with a higher content of chlorophylls and of total phenolic compounds, regardless of the level used, in the maté from both cultivation areas.

  2. Phylogenetic stratigraphy in the Guerrero Negro hypersaline microbial mat.

    Science.gov (United States)

    Harris, J Kirk; Caporaso, J Gregory; Walker, Jeffrey J; Spear, John R; Gold, Nicholas J; Robertson, Charles E; Hugenholtz, Philip; Goodrich, Julia; McDonald, Daniel; Knights, Dan; Marshall, Paul; Tufo, Henry; Knight, Rob; Pace, Norman R

    2013-01-01

    The microbial mats of Guerrero Negro (GN), Baja California Sur, Mexico historically were considered a simple environment, dominated by cyanobacteria and sulfate-reducing bacteria. Culture-independent rRNA community profiling instead revealed these microbial mats as among the most phylogenetically diverse environments known. A preliminary molecular survey of the GN mat based on only ∼1500 small subunit rRNA gene sequences discovered several new phylum-level groups in the bacterial phylogenetic domain and many previously undetected lower-level taxa. We determined an additional ∼119,000 nearly full-length sequences and 28,000 >200 nucleotide 454 reads from a 10-layer depth profile of the GN mat. With this unprecedented coverage of long sequences from one environment, we confirm the mat is phylogenetically stratified, presumably corresponding to light and geochemical gradients throughout the depth of the mat. Previous shotgun metagenomic data from the same depth profile show the same stratified pattern and suggest that metagenome properties may be predictable from rRNA gene sequences. We verify previously identified novel lineages and identify new phylogenetic diversity at lower taxonomic levels, for example, thousands of operational taxonomic units at the family-genus levels differ considerably from known sequences. The new sequences populate parts of the bacterial phylogenetic tree that previously were poorly described, but indicate that any comprehensive survey of GN diversity has only begun. Finally, we show that taxonomic conclusions are generally congruent between Sanger and 454 sequencing technologies, with the taxonomic resolution achieved dependent on the abundance of reference sequences in the relevant region of the rRNA tree of life.

  3. Transglutaminase reactivity with gelatine: perspective applications in tissue engineering.

    Science.gov (United States)

    Bertoni, F; Barbani, N; Giusti, P; Ciardelli, G

    2006-05-01

    Gelatine was crosslinked by means of an enzymatic treatment using tissue transglutaminase (tTGase) (Sigma) and microbial transglutaminase (mTGase) (Ajinomoto) which catalyses the formation of isopeptide bonds between the gamma-carbonyl group of a glutamine residue and the epsilon-amino group of a lysine residue. The reaction is an interesting alternative to the traditional glutaraldehyde crosslinking, which has several drawbacks (e.g., in medical application) due to the toxicity of the chemical reagent. To further investigate the possibility to utilize the modified protein for tissue engineering application, TGase crosslinked gelatine was incorporated in a gellan matrix, a polysaccharide, to enhance the stability in aqueous media. Films obtained by casting were characterized by thermal analysis, chemical imaging, swelling behaviour and cell adhesion.

  4. Evaluation of hard gelatin capsules and hydroxypropyl methylcellulose containing ampicillin

    Directory of Open Access Journals (Sweden)

    Graziella Gonçalves Weigert

    2012-01-01

    Full Text Available This study aims to develop and evaluate formulations containing ampicillin in capsules of gelatin and hydroxypropyl methylcellulose (HPMC. Two formulations (A and B were developed. The final product quality was evaluated by testing for quality control and the results were in agreement with the Brazilian Pharmacopoeia. The formulations with HPMC capsules showed lower percentages of drug dissolved (99.67%, HPMC-A and 87.70%, HPMC-B than the gelatin (100.18%, GEL-A and 101.16% GEL-B. Because of the delay of the ampicillin release observed in the dissolution profiles, it becomes necessary to evaluate the drugs that can be conditioned in the HPMC capsules.

  5. On-Demand Microwave-Assisted Fabrication of Gelatin Foams

    Directory of Open Access Journals (Sweden)

    Shane D. Frazier

    2018-05-01

    Full Text Available Ultraporous gelatin foams (porosity >94%, ρ ≈ 0.039–0.056 g/cm3 have been fabricated via microwave radiation. The resulting foam structures are unique with regard to pore morphology (i.e., closed-cell and exhibit 100% macroporosity (pore size 332 to 1700 μm, presence of an external skin, and densities similar to aerogels. Results indicate that the primary foaming mechanism is governed by the vaporization of water that is tightly bound in secondary structures (i.e., helices, β-turns, β-sheets that are present in dehydrated gelatin films but not present in the foams after microwave radiation (700 Watts.

  6. Gelatin films plasticized with a simulated biodiesel coproduct stream

    Directory of Open Access Journals (Sweden)

    2009-04-01

    Full Text Available In order to explore the possibility of substituting an unrefined biodiesel coproduct stream (BCS for refined glycerol as a polymer plasticizer we have prepared cast gelatin films plasticized with a simulated BCS, i.e., mixtures of glycerol and some of the typical components found in BCS (methyl linoleate, methyl oleate, linoleic acid, and oleic acid. We measured the tensile properties as a function of plasticizer composition, and analyzed the specific effect of each individual component on tensile properties. We found that it is the unrecovered alkyl esters that largely determine the tensile properties, and that BCS can be successfully used to plasticize cast gelatin films as long as the BCS contains 11 parts by weight, or less, of unrecovered alkyl esters per 100 parts glycerol.

  7. Doubly slanted layer structures in holographic gelatin emulsions: solar concentrators

    International Nuclear Information System (INIS)

    Hung, Jenny; Tam, Wing Yim; Chan, Po Shan; Sun, Caiming; Ho, Choi Wing

    2010-01-01

    We have fabricated doubly slanted layer structures in holographic gelatin emulsions using a double-exposure two-beam interference from two light sources with different wavelengths. The doubly slanted layers, with different spacings and overlapping with each other, are fabricated such that they are slanted in opposite directions making a 30° angle with the holographic plate. The doubly slanted layer structures exhibit photonic stop bands corresponding to the two layered structures. More importantly, diffracted light beams from the slanted layers travel in different directions and emerge, through internal reflections, at the opposite edges of the gelatin plate. The doubly slanted layer structures could be used as solar concentrators such that sunlight is separated into different components and steered directly to photovoltaics with the corresponding wavelength sensitivities to enhance energy conversion efficiency

  8. Flow of light energy in benthic photosynthetic microbial mats

    Energy Technology Data Exchange (ETDEWEB)

    Al-Najjar, Mohammad Ahmad A.

    2010-12-15

    The work in this thesis demonstrates the assessment of the energy budget inside microbial mat ecosystems, and the factors affecting light utilization efficiency. It presents the first balanced light energy budget for benthic microbial mat ecosystems, and shows how the budget and the spatial distribution of the local photosynthetic efficiencies within the euphotic zone depend on the absorbed irradiance (Jabs). The energy budget was dominated by heat dissipation on the expense of photosynthesis. The maximum efficiency of photosynthesis was at light limiting conditions When comparing three different marine benthic photosynthetic ecosystems (originated from Abu-Dhabi, Arctic, and Exmouth Gulf in Western Australia), differences in the efficiencies were calculated. The results demonstrated that the maximum efficiency depended on mat characteristics affecting light absorption and scattering; such as, photopigments ratio and distribution, and the structural organization of the photosynthetic organisms relative to other absorbing components of the ecosystem (i.e., EPS, mineral particles, detritus, etc.). The maximum efficiency decreased with increasing light penetration depth, and increased with increasing the accessory pigments (phycocyanin and fucoxanthin)/chlorophyll ratio. Spatial heterogeneity in photosynthetic efficiency, pigment distribution, as well as light acclimation in microbial mats originating from different geographical locations was investigated. We used a combined pigment imaging approach (variable chlorophyll fluorescence and hyperspectral imaging), and fingerprinting approach. For each mat, the photosynthetic activity was proportional to the local pigment concentration in the photic zone, but not for the deeper layers and between different mats. In each mat, yield of PSII and E1/2 (light acclimation) generally decreased in parallel with depth, but the gradients in both parameters varied greatly between samples. This mismatch between pigments concentration

  9. Antibacterial performance of bovine lactoferrin-fish gelatine electrospun nanocomposites

    OpenAIRE

    Padrão, Jorge; Machado, Raul; Casal, Margarida; Rodrigues, L. R.; Dourado, Fernando; Lanceros-Méndez, S.; Sencadas, V.

    2014-01-01

    Antibacterial performance of bovine lactoferrin-fish gelatine electrospun nanocomposites The alarming increase of antibiotic resistant microorganisms urged the development and synthesis of novel antimicrobial biomaterials, to be employed in a broad range of applications, ranging from food casings to medical devices [1 – 3]. This work describes the processing and characterization of an innovative fully biobased eletrctrospun nanocomposite material displaying antibacterial properties. Its c...

  10. Preparation and characterization of gelatin/cerium(Ⅲ) film

    Institute of Scientific and Technical Information of China (English)

    黄崇军; 黄雅钦; 田娜; 童元建; 殷瑞贤

    2010-01-01

    A novel gelatin film with antibacterial activity was prepared by electrostatic crosslinking using cerium (Ⅲ) nitrate hexahydrate as the crosslinking agent. The structure and properties of the films were investigated by Fourier transform infrared spectra, tensile tests, thermogravimetric analysis, static drop contact angle and disc diffusion method. The results showed that cross-linking could not only improve the thermal and mechanical properties and lower the hydrophilic property of the films, but also make...

  11. Gelatin as a new humidity sensing material: Characterization and limitations

    Energy Technology Data Exchange (ETDEWEB)

    Shapardanis, Steven [School of Engineering and Technology, Central Michigan University, Mt. Pleasant, Michigan, 48859 (United States); Hudpeth, Mathew [Department of Physics, Central Michigan University, Mt. Pleasant, Michigan, 48859 (United States); Kaya, Tolga, E-mail: kaya2t@cmich.edu [School of Engineering and Technology, Central Michigan University, Mt. Pleasant, Michigan, 48859 (United States); Science of Advanced Materials Program, Central Michigan University, Mt. Pleasant, Michigan, 48859 (United States)

    2014-12-15

    The goal of this work is to assert the utility of collagen and its denatured counterpart gelatin as cost-effective alternatives to existing sensing layers comprised of polymers. Rather than producing a material that will need to be discarded or recycled, collagen, as a by-product of the meat and leather industry, could be repurposed. This work examines the feasibility of using collagen as a sensing layer. Planar electrodes were patterned with lift-off process to work with the natural characteristics of gelatin by utilizing metal vapor deposition, spin coating, and photolithography. Characterization methods have also been optimized through the creation of specialized humidity chambers that isolate specific characteristics such as response time, accuracy, and hysteresis. Collagen-based sensors are found to have a sensitivity to moisture in the range of 0.065 pF/%RH. Diffusion characteristics were also analyzed with the diffusion coefficient found to be 2.5 × 10{sup −5} cm{sup 2}/s. Absorption and desorption times were found to be 20 seconds and 8 seconds, respectively. Hysteresis present in the data is attributed to temperature cross-sensitivity. Ultimately, the utility of collagen as a dielectric sensing material is, in part, due to its fibrous macrostructures as well its hydrophilic sites along the peptide chains. Gelatin was patterned between and below interdigitated copper electrodes and tested as a relative humidity sensor. This work shows that gelatin, which is inexpensive, widely available, and easy to process, can be an effective dielectric sensing polymer for capacitive-type relative humidity sensors.

  12. Gelatin as a new humidity sensing material: Characterization and limitations

    Directory of Open Access Journals (Sweden)

    Steven Shapardanis

    2014-12-01

    Full Text Available The goal of this work is to assert the utility of collagen and its denatured counterpart gelatin as cost-effective alternatives to existing sensing layers comprised of polymers. Rather than producing a material that will need to be discarded or recycled, collagen, as a by-product of the meat and leather industry, could be repurposed. This work examines the feasibility of using collagen as a sensing layer. Planar electrodes were patterned with lift-off process to work with the natural characteristics of gelatin by utilizing metal vapor deposition, spin coating, and photolithography. Characterization methods have also been optimized through the creation of specialized humidity chambers that isolate specific characteristics such as response time, accuracy, and hysteresis. Collagen-based sensors are found to have a sensitivity to moisture in the range of 0.065 pF/%RH. Diffusion characteristics were also analyzed with the diffusion coefficient found to be 2.5 × 10−5 cm2/s. Absorption and desorption times were found to be 20 seconds and 8 seconds, respectively. Hysteresis present in the data is attributed to temperature cross-sensitivity. Ultimately, the utility of collagen as a dielectric sensing material is, in part, due to its fibrous macrostructures as well its hydrophilic sites along the peptide chains. Gelatin was patterned between and below interdigitated copper electrodes and tested as a relative humidity sensor. This work shows that gelatin, which is inexpensive, widely available, and easy to process, can be an effective dielectric sensing polymer for capacitive-type relative humidity sensors.

  13. The heterothallic sugarbeet pathogen Cercospora beticola contains exon fragments of both MAT genes that are homogenized by concerted evolution

    NARCIS (Netherlands)

    Bolton, M.D.; Jonge, de R.; Inderbitzin, P.; Liu, Z.; Birla, K.; Peer, Van de Y.; Subbarao, K.; Thomma, B.P.H.J.; Secor, G.

    2014-01-01

    Dothideomycetes is one of the most ecologically diverse and economically important classes of fungi. Sexual reproduction in this group is governed by mating type (MAT) genes at the MAT1 locus. Self-sterile (heterothallic) species contain one of two genes at MAT1 (MAT1-1-1 or MAT1-2-1) and only

  14. Electrospun Poly(lactic acid)-Based Fibrous Nanocomposite Reinforced by Cellulose Nanocrystals: Impact of Fiber Uniaxial Alignment on Microstructure and Mechanical Properties.

    Science.gov (United States)

    Huan, Siqi; Liu, Guoxiang; Cheng, Wanli; Han, Guangping; Bai, Long

    2018-03-12

    Uniform poly(lactic acid)/cellulose nanocrystal (PLA/CNC) fibrous mats composed of either random or aligned fibers reinforced with up to 20 wt % CNCs were successfully produced by two different electrospinning processes. Various concentrations of CNCs could be stably dispersed in PLA solution prior to fiber manufacture. The microstructure of produced fibrous mats, regardless of random or aligned orientation, was transformed from smooth to nanoporous surface by changing CNC loading levels. Aligning process through secondary stretching during high-speed collection can also affect the porous structure of fibers. With the same CNC loading, fibrous mats produced with aligned fibers had higher degree of crystallinity than that of fibers with random structure. The thermal properties and mechanical performances of PLA/CNC fibrous mats can be enhanced, showing better enhancement effect of aligned fibrous structure. This results from a synergistic effect of the increased crystallinity of fibers, the efficient stress transfer from PLA to CNCs, and the ordered arrangement of electrospun fibers in the mats. This research paves a way for developing an electrospinning system that can manufacture high-performance CNC-enhanced PLA fibrous nanocomposites.

  15. Gelatin model for training ultrasound-guided puncture

    Directory of Open Access Journals (Sweden)

    Alexandre Campos Moraes Amato

    2015-09-01

    Full Text Available BACKGROUND: It is indispensable that members of the medical profession receive the technical training needed to enable them to rapidly obtain effective vascular access. Training procedures should be used judiciously to familiarize students with the technique. However, existing models are expensive or ineffective, and models need to be developed that are similar to what will be encountered in real patients.OBJECTIVES: To demonstrate creation and application of a gelatin model for training ultrasound-guided puncture.METHOS: The model was made using a mixture of colorless gelatin and water in a transparent plastic receptacle with two pairs of orifices of different diameters, through which two plastic tubes were inserted, to simulate blood vessels.RESULTS: The model was a close approximation to the real medical procedure in several aspects, since gelatin has a similar consistency to human tissues, providing a more faithful reproduction of the tactile sensation at the moment when the needle reaches the interior of a vessel and its contents are aspirated.CONCLUSIONS: The method proposed here can be used to easily construct a low-cost model using everyday materials that is suitable for large-scale training of ultrasound-guided puncture.

  16. Effect of extraction temperature on characteristics of chicken legskin gelatin

    Science.gov (United States)

    Sompie, M.; Triasih, A.

    2018-01-01

    Gelatin is a denaturalized protein that is derived from collagen by acidic or alkaline hydrolysis and is an important functional biopolymer that has a very broad application in many industrial fields. Its functional properties depend on processing conditions as well as the raw material. The objective of the research was to study effect of extraction temperature on characteristics of native chicken legskin gelatin. This study used Completely Randomized Design (CRD) with four treatments (T1 = 500C, T2 = 550C, T3 = 600C, T4 = 650C) and five replications. Statistical analysis were carried out by one Anova and the mean difference was tested using Duncan’s Multiple Range Test. The result of research indicated that, extraction temperature had significant effect (Pchicken legskin gelatin, but it had no significant effect (P>0.05) on water content. It was concluded that the use of extraction temperature 600C was (yields 13.75, gel strength 78.75 g bloom, viscosity 6.52 cP, protein content 84.23% and water content 6.20%).

  17. The study of consistent properties of gelatinous shampoo with minoxidil

    Directory of Open Access Journals (Sweden)

    I. V. Gnitko

    2016-04-01

    Full Text Available The aim of the work is the study of consistent properties of gelatinous shampoo with minoxidil 1% for the complex therapy and prevention of alopecia. This shampoo with minoxidil was selected according to the complex physical-chemical, biopharmaceutical and microbiological investigations. Methods and results. It has been established that consistent properties of the gelatinous minoxidil 1% shampoo and the «mechanical stability» (1.70 describe the formulation as exceptionally thixotropic composition with possibility of restoration after mechanical loads. Also this fact allows to predict stability of the consistent properties during long storage. Conclusion. Factors of dynamic flowing for the foam detergent gel with minoxidil (Кd1=38.9%; Kd2=78.06% quantitatively confirm sufficient degree of distribution at the time of spreading composition on the skin surface of the hairy part of head or during technological operations of manufacturing. Insignificant difference of «mechanical stability» for the gelatinous minoxidil 1% shampoo and its base indicates the absence of interactions between active substance and the base.

  18. Study and characterization of porous ceramic obtained via gelatinization

    International Nuclear Information System (INIS)

    Storion, A.G.; Campos, M.G.N.; Mariano, N.A.; Maestrelli, S.C.; Mariano, W.A.

    2016-01-01

    Conventional processes for manufacturing porous ceramic sometimes provide bodies with low mechanical strength, showing cracks and macro defects, in addition to the high complexity or cost. This work proposes a new porous ceramic processing route called cold gelatinization, using as raw material a clay with low plasticity, water and gelatin. At first, the characterization of the clay was carried out and then specimens of various compositions were produced by varying clay content (40, 50, 55 and 60% of solids) and keeping the water and gelatin content constant in the formulation. After cold forming the samples were and fired under various conditions: initial temperature of 300 or 600 °C; maximum firing temperature of 800, 900, 1000, 1100 or 1350 °C. After firing, it was obtained water absorption, apparent density, apparent porosity, linear shrinkage and mechanical resistance via 3 points bending test. The best results were for samples fired in temperatures lower than 1100 °C and 50% and 55 % of solid content. (author)

  19. KARAKTERISTIK EDIBLE FILM YANG DIPRODUKSI DARI KOMBINASI GELATIN KULIT KAKI AYAM DAN SOY PROTEIN ISOLATE

    Directory of Open Access Journals (Sweden)

    Muhamad Hasdar

    2012-09-01

    SDS-PAGE dan menunjukkan sebagai molekul kolagen. Hasil analisis kandungan asam amino edible film menggunakan HPLC dihasilkan komposisi residu asam amino terbesar adalah glysin yaitu 29,42%, 37,88%, 38,32%, 39,28% dan 39,17% pada masing-masing perlakuan. Hal itu menggambarkan bahwa profil protein edible film dapat dipastikan sebagian besar berasal dari kolagen gelatin. Pengamatan dengan scaning electron microscope menunjukkan telah terbentuk cross linking antara molekul protein gelatin dan molekul soy protein isolate dan yang ditunjukan semakin berkurangnya retakan seiring dengan meningkatnya konsentrasi gelatin. Perbedaan kombinasi gelatin kulit kaki ayam dan soy protein isolate untuk membentuk edible film tidak memberikan pengaruh nyata pada kekuatan tarik (tensile strenght, dan kemuluran (elongation, namun berpengaruh nyata pada laju transmisi uap air (Water Vapour Transmision Rate. Kombinasi 95:5 protein gelatin kulit kaki ayam dan soy protein isolate menghasilkan edible film yang terbaik. (Kata kunci: Edible film, Gelatin kaki ayam, Soy protein isolate

  20. Antimicrobial and Barrier Properties of Bovine Gelatin Films Reinforced by Nano TiO2

    Directory of Open Access Journals (Sweden)

    R. Nassiri

    2013-11-01

    Full Text Available The effects of nano titanium dioxide incorporation were investigated on the water vaporpermeability, oxygen permeability, and antimicrobial properties of bovine gelatin films. The nano TiO2 (TiO2-N was homogenized by sonication and incorporated into bovine gelatin solutions at different concentrations(e.g. 1, 2, 3, and 5% w/w of dried gelatin. The permeability of the films to water vapor and oxygen wassignificantly decreased by incorporating of low concentration TiO2-N to gelatin solutions. TiO2-N gelatin filmsshowed an excellent antimicrobial activity against Staphylococcus aureus and Escherichia coli. Theseproperties suggest that TiO2-N has the potential as filler in gelatin-based films for using as an active packagingmaterials in pharmaceutical and food packaging industries.

  1. Damage assessment and progression in a polyisocyanurate-based continuous swirl mat composite

    Science.gov (United States)

    Worley, Darwell Carlton, II

    This research conducted in conjunction with Oak Ridge National Laboratories and the Automotive Composite Consortium, ACC, was motivated by the desire to reduce vehicle weight for increased efficiency. At present, there are no databases of failure mechanisms, experimental procedures to study failure, mathematical expressions for empirical or theoretical prediction of properties of a continuous swirl mat composite, CSMC. Therefore, to contribute to the increased utilization of this class of materials the following research was performed. This research enabled the failure mechanism to be formulated, development of a method to quantify failure based on ultrasonic attenuation maps, and the prediction of the fracture toughness parameter KIC. The use of scanning electron microscopy, light microscopy, and real-time tensile loading showed that the CSMC failed in a brittle mode. These techniques also provided imaging information as to how a dominant crack propagates in the presence of a continuously swirled E-glass mat reinforcement and voids. This evaluation enabled a reconstruction of failure in order to demonstrate a possible failure mechanism. The aforementioned techniques revealed that the dominant crack follows the fiber/matrix interface, but may be influenced by the presence of voids. Voids have the tendency of luring the growing crack away from the interface. A growing crack would, however, return to a fiber/matrix interface until complete failure occurred. Another aspect of this work was the quantification of progressive damage using ultrasound. Comparisons were made between ultrasonic attenuation maps for unloaded and sequentially loaded specimens. The sequential loads were applied at different percentages of the ultimate tensile strength, UTS. This technique provided attenuation maps for a series of specimens with a controlled degree of damage, which showed an increase in attenuation with an increase in percent UTS. Fracture toughness experiments yielded an

  2. Differentiation of neuronal stem cells into motor neurons using electrospun poly-L-lactic acid/gelatin scaffold.

    Science.gov (United States)

    Binan, Loïc; Tendey, Charlène; De Crescenzo, Gregory; El Ayoubi, Rouwayda; Ajji, Abdellah; Jolicoeur, Mario

    2014-01-01

    Neural stem cells (NSCs) provide promising therapeutic potential for cell replacement therapy in spinal cord injury (SCI). However, high increases of cell viability and poor control of cell differentiation remain major obstacles. In this study, we have developed a non-woven material made of co-electrospun fibers of poly L-lactic acid and gelatin with a degradation rate and mechanical properties similar to peripheral nerve tissue and investigated their effect on cell survival and differentiation into motor neuronal lineages through the controlled release of retinoic acid (RA) and purmorphamine. Engineered Neural Stem-Like Cells (NSLCs) seeded on these fibers, with and without the instructive cues, differentiated into β-III-tubulin, HB-9, Islet-1, and choactase-positive motor neurons by immunostaining, in response to the release of the biomolecules. In addition, the bioactive material not only enhanced the differentiation into motor neuronal lineages but also promoted neurite outgrowth. This study elucidated that a combination of electrospun fiber scaffolds, neural stem cells, and controlled delivery of instructive cues could lead to the development of a better strategy for peripheral nerve injury repair. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Targeting S-adenosylmethionine biosynthesis with a novel allosteric inhibitor of Mat2A

    Energy Technology Data Exchange (ETDEWEB)

    Quinlan, Casey L.; Kaiser, Stephen E.; Bolaños, Ben; Nowlin, Dawn; Grantner, Rita; Karlicek-Bryant, Shannon; Feng, Jun Li; Jenkinson, Stephen; Freeman-Cook, Kevin; Dann, Stephen G.; Wang, Xiaoli; Wells, Peter A.; Fantin, Valeria R.; Stewart, Al E.; Grant, Stephan K. (Pfizer)

    2017-05-29

    S-Adenosyl-L-methionine (SAM) is an enzyme cofactor used in methyl transfer reactions and polyamine biosynthesis. The biosynthesis of SAM from ATP and L-methionine is performed by the methionine adenosyltransferase enzyme family (Mat; EC 2.5.1.6). Human methionine adenosyltransferase 2A (Mat2A), the extrahepatic isoform, is often deregulated in cancer. We identified a Mat2A inhibitor, PF-9366, that binds an allosteric site on Mat2A that overlaps with the binding site for the Mat2A regulator, Mat2B. Studies exploiting PF-9366 suggested a general mode of Mat2A allosteric regulation. Allosteric binding of PF-9366 or Mat2B altered the Mat2A active site, resulting in increased substrate affinity and decreased enzyme turnover. These data support a model whereby Mat2B functions as an inhibitor of Mat2A activity when methionine or SAM levels are high, yet functions as an activator of Mat2A when methionine or SAM levels are low. The ramification of Mat2A activity modulation in cancer cells is also described.

  4. Aditivos químicos ou biológicos na ensilagem de cana-de-açúcar: 2. parâmetros ruminais e degradabilidade da matéria seca e das frações fibrosas Chemical and biological additives in sugar cane silages: 2. ruminal parameters and DM and fiber degradabilities

    Directory of Open Access Journals (Sweden)

    Patrick Schmidt

    2007-10-01

    on ruminal fermentation parameters in bovines fed with diets containing these silages. Five rumen-cannulated Nelore steers were allotted to a 5 x 5 latin square design. The steers were placed in metabolic cages and fed diets with 65% forage (%DM. Five silages were evaluated (wet basis: Control sugar cane, no additives; Urea sugar cane + 0.5% of urea; Benzoate sugar cane + 0.1% of sodium benzoate; LP - sugar cane inoculated with Lactobacillus plantarum (1 x 10(6 cfu/g forage; LB sugar cane inoculated with L. buchneri (3.6 x 10(5 cfu/g forage. During 90 days, before the animal feeding, the forage was stocked in vertical silos.Ruminal parameters were slightly affected by the silages and a strong effect of sampling time. Averages of molar concentration of acetic, propionic and butyric acids were 60.9, 19.3, and 10.2 mM, respectively. Ruminal environment proportionate by the formulated diets with sugar cane sugar silages was satisfactory and similar to traditionally observed in diets containing sugar cane. The additive used in the ensiling influenced, in a no-significant form, the ruminal degradability of DM an OM, but it did not alter the ruminal degradability of the fiber fraction. The additives applied to the sugar cane resulted in slightly alterations? for most evaluated variable. Although the ruminal degradability of silages was little affected by the additive use, the observed values were similar to the observed for the sugar cane in natura.

  5. Extraction optimization and characterization of gelatine from fish dry skin of Spanish mackerel (Scomberromorus commersoni)

    Science.gov (United States)

    Kusumaningrum, I.; Pranoto, Y.; Hadiwiyoto, S.

    2018-04-01

    This work was to optimized gelatin extraction from dry skin of Spanish mackerel (Scomberromorus commersoni) using Response Surface Methodology (RSM). The aim of this study was to determine the optimal condition of temperature and time for extraction process and properties of the gelatin extracted from dry mackerel skin. The optimal condition for extraction was 59.71°C for 4.25 hours. Results showed that predicted yield by RSM was 13.69% and predicted gel strength was 291.93 Bloom, whereas the actual experiment for yield and gel strength were 13.03% and 291.33 Bloom, respectively. The gelatin extracted from dried skin were analyzed for their proximate composition, yield, gel strength, viscosity, color, and amino acid composition. The results of dried skin gelatin properties compared to the commercial gelatin. Gelatin extracted from the dried skin gave content lower moisture, ash and protein content but higher fat compared to commercial gelatin. This study also shows that the gelatin extracted from the dried skin gave higher gel strength and pH but the lower amino acid composition compared to commercial gelatin.

  6. Gelatin Nano-coating for Inhibiting Surface Crystallization of Amorphous Drugs.

    Science.gov (United States)

    Teerakapibal, Rattavut; Gui, Yue; Yu, Lian

    2018-01-05

    Inhibit the fast surface crystallization of amorphous drugs with gelatin nano-coatings. The free surface of amorphous films of indomethacin or nifedipine was coated by a gelatin solution (type A or B) and dried. The coating's effect on surface crystallization was evaluated. Coating thickness was estimated from mass change after coating. For indomethacin (weak acid, pK a  = 4.5), a gelatin coating of either type deposited at pH 5 and 10 inhibited its fast surface crystal growth. The coating thickness was 20 ± 10 nm. A gelatin coating deposited at pH 3, however, provided no protective effect. These results suggest that an effective gelatin coating does not require that the drug and the polymer have opposite charges. The ineffective pH 3 coating might reflect the poor wetting of indomethacin's neutral, hydrophobic surface by the coating solution. For nifedipine (weak base, pK a  = 2.6), a gelatin coating of either type deposited at pH 5 inhibited its fast surface crystal growth. Gelatin nano-coatings can be conveniently applied to amorphous drugs from solution to inhibit fast surface crystallization. Unlike strong polyelectrolyte coatings, a protective gelatin coating does not require strict pairing of opposite charges. This could make gelatin coating a versatile, pharmaceutically acceptable coating for stabilizing amorphous drugs.

  7. Variation of Hydroxyapatite Content in Soft Gelatin Affects Mesenchymal Stem Cell Differentiation

    Directory of Open Access Journals (Sweden)

    Fahsai Kantawong

    2016-01-01

    Full Text Available Gelatin is a common material used in tissue engineering and hydroxyapatite (HA has a composition and structure similar to natural bone mineral. HA is also used to increase the adhesion ability of scaffolds. The physical and mechanical properties of gelatin, together with the chemical properties of HA, can affect cell differentiation. The main purpose of this study is to investigate the gene expression of human mesenchymal stem cells (HMSCs upon culturing on gelatin composite with HA. Low amounts of HA were introduced into the gelatin in order to modulate properties of gelatin. Three types of hydrogel were fabricated by glutaraldehyde crosslinking before lyophilization to produce the porous 3D structure: (1 pure gelatin, (2 0.5 mg/ml HA in gelatin, and (3 1 mg/ml HA in gelatin. The fabricated hydrogels were used as scaffolds to cultivate HMSCs for two periods - 24 hours and 3 weeks. The results showed that all types of fabricated hydrogels could be used to cultivate HMSCs. Changes of gene expressions indicated that the HMSCs cultured on the 1 mg/ml HA in gelatin showed neuronal lineage-specific differentiation.

  8. Study and characterization of powder mackerel (Scomberomorus commerson) bone gelatin through hydrolysis of hydrochloric acid

    Science.gov (United States)

    Mardawati, E.; Sugandi, H.; Kayaputri, I. L.; Cahyana, Y.; Wira, D. W.; Pujianto, T.; Kastaman, R.

    2018-02-01

    Gelatin is one of the most common food additives in the food and beverage industry. Gelatin is generally made of leather or pig bones, causing concerns about the halal and safety of its product. Mackerel fish bone (Scomberomorus commerson) is a waste fish that has not been utilized well and it contains 18.6% of collagen so that it can be made into gelatin. The purpose of this research is to know the relation between HCl concentration with physical and chemical characteristics of gelatin and to know the best HCl concentration for gelatin production. Based on the physical and chemical analysis of gelatin, it is known that the concentration of hydrochloric acid influences the yield, viscosity, gel strength and pH produced. The higher HCl concentration there will be decrease in the pH value, gel strength, viscosity and protein. The yield will rise to the optimum point then decrease with respect to the high HCl concentration. Gelatin with 2% HCl concentration was the best treatment, with pH value 3.83, viscosity 3.65cP, gel strength 190.50 blooms which fulfilled British Standard, yield 10.16%, protein content 43.34%. It has functional group such as amino acids glycine, proline and hydroxyproline and 15 other amino acids, the gelatin group uptake in the region of amide wave numbers A, amides I, II and III, with a gelatin molecular weight of 290.35 g/mol.

  9. Preparation of spherical silver particles for solar cell electronic paste with gelatin protection

    International Nuclear Information System (INIS)

    Ao Yiwei; Yang Yunxia; Yuan Shuanglong; Ding Lihua; Chen Guorong

    2007-01-01

    Spherical silver particles used in electronic paste for solar cell were prepared using the chemical reduction method with ammonia as a complex agent, hydrazine hydrate as a reducing agent, and gelatin as a protective agent. The gelatin protective mechanism in the preparing process of spherical silver particles was studied. Observations of SEM and results of laser particle size analysis and ultraviolet absorption spectra demonstrate the formation of the coordinative complex of silver ions with gelatin in aqueous solution which accelerated the reduction of silver ions. Moreover, gelatin can promote the nucleation of the metallic silver particles, thus beneficiating availability of the monodisperse spherical silver particles

  10. Microbial mat-induced sedimentary structures in siliciclastic sediments

    Indian Academy of Sciences (India)

    This paper addresses macroscopic signatures of microbial mat-related structures within the. 1.6Ga-old Chorhat Sandstone ... Sandstone differentiated in facies superposed one over the other and their respective structural assemblages (b). may be ..... within the classification of primary sedimentary struc- tures; J. Sed. Res.

  11. The Varian MAT-250 mass spectrometer. Steady isotopes laboratory

    International Nuclear Information System (INIS)

    Hernandez M, V.; Tavera D, M.L.

    1997-01-01

    This work treats over the performance and applications of the Varian Mat-250 mass spectrometer which is in the environmental isotope laboratory. It can be applied over topics such as: ions formation, acceleration and collimation, ions separation, ions detection, data transformation, sampling, δ notation. (Author)

  12. The Ububele Baby Mat Service – A primary preventative mental ...

    African Journals Online (AJOL)

    The Ububele Baby Mat Service is a community-based, parent–infant mental health intervention offered at five primary health care clinics in Alexandra Township, in Johannesburg. The aim of the intervention is to promote healthy caregiver-infant attachments. There has been a steady increase in the number of mother-baby ...

  13. Evaluation of the WavTrac Expeditionary Mobility Matting System

    Science.gov (United States)

    2017-04-01

    Dr. Timothy W. Rushing was Chief, APB; Dr. Gordon W. McMahon was Chief, ESMD; and Nicholas Boone was the Technical Director for Force Projection...were tan in color and had a nonskid material applied to the wearing surface. Typical mat dimensions were 12 ft, 2 in. wide by 48 ft, 6 in. long

  14. Social yoga mats: reinforcing synergy between physical and social activity

    DEFF Research Database (Denmark)

    Nagargoje, Arun; Sokoler, Tomas; Maybach, Karl

    2011-01-01

    This paper discusses our early research into the design space for digital technologies that extend the existing synergistic relationship between physical and social activity from fitness centers to the home. We focus on yoga activity for senior citizens and explore the concept of social yoga mats...

  15. Matting of Hair Due to Halo-egg Shampoo

    Directory of Open Access Journals (Sweden)

    Z M Mani

    1983-01-01

    Full Text Available A case of hair matting in an 18 year old female is reported. The hair got densely entangled immediately after washing the hair with ′Halo Egg′ shampoo. The hair was disentangled completely after prolonged dipping of the hair in arachis oil frr 5 days.

  16. Diversity of nitrogen-fixing bacteria in cyanobacterial mats

    NARCIS (Netherlands)

    Severin, I.; Acinas, S.G.; Stal, L.J.

    2010-01-01

    The structure of the microbial community and the diversity of the functional gene for dinitrogenase reductase and its transcripts were investigated by analyzing >1400 16S rRNA gene and nifH sequences from two microbial mats situated in the intertidal zone of the Dutch barrier island Schiermonnikoog.

  17. Response of cyanobacterial mats to nutrient and salinity changes

    Czech Academy of Sciences Publication Activity Database

    Rejmánková, E.; Komárková, Jaroslava

    2005-01-01

    Roč. 83, č. 2 (2005), s. 87-107 ISSN 0304-3770. [INTECOL International Wetlands Conference /7./. Utrecht, 25.07.2004-30.7.2004] Grant - others:NSF(US) 0089211 Institutional research plan: CEZ:AV0Z60170517 Keywords : cyanobacterial mats * Belize * P-N impact Subject RIV: EH - Ecology, Behaviour Impact factor: 1.344, year: 2005

  18. Advanced HVAC modeling with FemLab/Simulink/MatLab

    NARCIS (Netherlands)

    Schijndel, van A.W.M.

    2003-01-01

    The combined MatLab toolboxes FemLab and Simulink are evaluated as solvers for HVAC problems based on partial differential equations (PDEs). The FemLab software is designed to simulate systems of coupled PDEs, 1-D, 2-D or 3-D, nonlinear and time dependent. In order to show how the program works, a

  19. Coastal Microbial Mat Diversity along a Natural Salinity Gradient

    NARCIS (Netherlands)

    Bolhuis, H.; Fillinger, L.; Stal, L.J.

    2013-01-01

    The North Sea coast of the Dutch barrier island of Schiermonnikoog is covered by microbial mats that initiate a succession of plant communities that eventually results in the development of a densely vegetated salt marsh. The North Sea beach has a natural elevation running from the low water mark to

  20. Preparation of Fish Skin Gelatin-Based Nanofibers Incorporating Cinnamaldehyde by Solution Blow Spinning

    Science.gov (United States)

    Liu, Fei; Avena-Bustillos, Roberto J.; Bridges, David F.; Takeoka, Gary R.; Wu, Vivian C. H.; Chiou, Bor-Sen; McHugh, Tara H.; Zhong, Fang

    2018-01-01

    Cinnamaldehyde, a natural preservative that can non-specifically deactivate foodborne pathogens, was successfully incorporated into fish skin gelatin (FSG) solutions and blow spun into uniform nanofibers. The effects of cinnamaldehyde ratios (5–30%, w/w FSG) on physicochemical properties of fiber-forming emulsions (FFEs) and their nanofibers were investigated. Higher ratios resulted in higher values in particle size and viscosity of FFEs, as well as higher values in diameter of nanofibers. Loss of cinnamaldehyde was observed during solution blow spinning (SBS) process and cinnamaldehyde was mainly located on the surface of resultant nanofibers. Nanofibers all showed antibacterial activity by direct diffusion and vapor release against Escherichia coli O157:H7, Salmonella typhimurium, and Listeria monocytogenes. Inhibition zones increased as cinnamaldehyde ratio increased. Nanofibers showed larger inhibition effects than films prepared by casting method when S. typhimurium was exposed to the released cinnamaldehyde vapor, although films had higher remaining cinnamaldehyde than nanofibers after preparation. Lower temperature was favorable for cinnamaldehyde retention, and nanofibers added with 10% cinnamaldehyde ratio showed the highest retention over eight-weeks of storage. Results suggest that FSG nanofibers can be prepared by SBS as carriers for antimicrobials. PMID:29470390

  1. Preparation of Fish Skin Gelatin-Based Nanofibers Incorporating Cinnamaldehyde by Solution Blow Spinning.

    Science.gov (United States)

    Liu, Fei; Türker Saricaoglu, Furkan; Avena-Bustillos, Roberto J; Bridges, David F; Takeoka, Gary R; Wu, Vivian C H; Chiou, Bor-Sen; Wood, Delilah F; McHugh, Tara H; Zhong, Fang

    2018-02-22

    Cinnamaldehyde, a natural preservative that can non-specifically deactivate foodborne pathogens, was successfully incorporated into fish skin gelatin (FSG) solutions and blow spun into uniform nanofibers. The effects of cinnamaldehyde ratios (5-30%, w / w FSG) on physicochemical properties of fiber-forming emulsions (FFEs) and their nanofibers were investigated. Higher ratios resulted in higher values in particle size and viscosity of FFEs, as well as higher values in diameter of nanofibers. Loss of cinnamaldehyde was observed during solution blow spinning (SBS) process and cinnamaldehyde was mainly located on the surface of resultant nanofibers. Nanofibers all showed antibacterial activity by direct diffusion and vapor release against Escherichia coli O157:H7 , Salmonella typhimurium , and Listeria monocytogenes . Inhibition zones increased as cinnamaldehyde ratio increased. Nanofibers showed larger inhibition effects than films prepared by casting method when S . typhimurium was exposed to the released cinnamaldehyde vapor, although films had higher remaining cinnamaldehyde than nanofibers after preparation. Lower temperature was favorable for cinnamaldehyde retention, and nanofibers added with 10% cinnamaldehyde ratio showed the highest retention over eight-weeks of storage. Results suggest that FSG nanofibers can be prepared by SBS as carriers for antimicrobials.

  2. Matérn-based nonstationary cross-covariance models for global processes

    KAUST Repository

    Jun, Mikyoung

    2014-01-01

    -covariance models, based on the Matérn covariance model class, that are suitable for describing prominent nonstationary characteristics of the global processes. In particular, we seek nonstationary versions of Matérn covariance models whose smoothness parameters

  3. Two-step activation of meiosis by the mat1 locus in Schizosaccharomyces pombe

    DEFF Research Database (Denmark)

    Willer, M; Hoffmann, Ulla-Lisbeth; Styrkársdóttir, U

    1995-01-01

    of meiosis is based largely on indirect observations, and a more precise investigation of these events was required to define the interaction between the mat1 genes. Here we resolve this issue using synthetic pheromones and P/M strains with mutations in either mat1-Pc or mat1-Mc. Our results suggest a model...... in which the mat1 locus plays two roles in controlling meiosis. In the first instance, the mat1-Pc and mat1-Mc functions are required to produce the mating pheromones and receptors that allow the generation of a pheromone signal. This signal is required to induce the expression of mat1-Pm and mat1-Mm...

  4. 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)

  5. Piezoelectric Microstructured Fibers via Drawing of Multimaterial Preforms.

    Science.gov (United States)

    Lu, Xin; Qu, Hang; Skorobogatiy, Maksim

    2017-06-06

    We demonstrate planar laminated piezoelectric generators and piezoelectric microstructured fibers based on BaTiO 3 -polyvinylidene and carbon-loaded-polyethylene materials combinations. The laminated piezoelectric generators were assembled by sandwiching the electrospun BaTiO 3 -polyvinylidene mat between two carbon-loaded-polyethylene films. The piezoelectric microstructured fiber was fabricated via drawing of the multilayer fiber preform, and features a swissroll geometry that have ~10 alternating piezoelectric and conductive layers. Both piezoelectric generators have excellent mechanical durability, and could retain their piezoelectric performance after 3 day's cyclic bend-release tests. Compared to the laminated generators, the piezoelectric fibers are advantageous as they could be directly woven into large-area commercial fabrics. Potential applications of the proposed piezoelectric fibers include micro-power-generation and remote sensing in wearable, automotive and aerospace industries.

  6. Amino Acid Profile, Group of Functional and Molecular Weight Distribution of Goat Skin Gelatin That Produced Through Acid Process

    Directory of Open Access Journals (Sweden)

    Muhammad Irfan Said

    2012-02-01

    Full Text Available Gelatin is a product of hydrolysis of collagen protein from animals that are partially processed.  Gelatin used in food and non food industries.  Gelatin is produced when many import of raw skins and bones of pigs and cows.  Goat skins potential as a raw material substitution that still doubt its halal. Process production of gelatin determine the properties of gelatin. The objectives of this research were to determine amino acid profile, group of functional and molecular weight distribution of gelatin made from goat skins which was produced through a process of acid. The skin of male Bligon goat, 1.5 to 2.5 year old was used as raw materials. Process production of gelatin was using acid type acetic acid (CH3COOH 0.5 M (v/v as curing material. The experimental design applied in this study and commercial gelatin was used as control. The results showed that gelatin produced from goat skin through the process of acid had properties identical with commercial gelatin. It can be concluded that the gelatin has the potential substitute product of commercial gelatin. Keywords: collagen, gelatin, goat skin, curing, acid process

  7. The Varian MAT-250 mass spectrometer. Steady isotopes laboratory; Espectrometro de masas Varian MAT-250. Laboratorio de isotopos estables

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez M, V.; Tavera D, M.L. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    This work treats over the performance and applications of the Varian Mat-250 mass spectrometer which is in the environmental isotope laboratory. It can be applied over topics such as: ions formation, acceleration and collimation, ions separation, ions detection, data transformation, sampling, {delta} notation. (Author)

  8. Comment on "Performance of a spin based insulated gate field effect transistor" [cond-mat/0603260] [cond-mat/0603260

    OpenAIRE

    Bandyopadhyay, S.; Cahay, M.

    2006-01-01

    In a recent e-print [cond-mat/0603260] Hall and Flatte claim that a particular spin based field effect transistor (SPINFET), which they have analyzed, will have a lower threshold voltage, lower switching energy and lower leakage current than a comparable metal oxide semiconductor field effect transistor (MOSFET). Here, we show that all three claims of HF are invalid.

  9. Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS) Users' Workshop Presentations

    Science.gov (United States)

    Litt, Jonathan S. (Compiler)

    2018-01-01

    NASA Glenn Research Center hosted a Users' Workshop on the Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS) on August 21, 2017. The objective of this workshop was to update the user community on the latest features of T-MATS, and to provide a forum to present work performed using T-MATS. Presentations highlighted creative applications and the development of new features and libraries, and emphasized the flexibility and simulation power of T-MATS.

  10. Regulation of electron transfer processes affects phototrophic mat structure and activity

    OpenAIRE

    Ha, Phuc T.; Renslow, Ryan S.; Atci, Erhan; Reardon, Patrick N.; Lindemann, Stephen R.; Fredrickson, James K.; Call, Douglas R.; Beyenal, Haluk

    2015-01-01

    Phototrophic microbial mats are among the most diverse ecosystems in nature. These systems undergo daily cycles in redox potential caused by variations in light energy input and metabolic interactions among the microbial species. In this work, solid electrodes with controlled potentials were placed under mats to study the electron transfer processes between the electrode and the microbial mat. The phototrophic microbial mat was harvested from Hot Lake, a hypersaline, epsomitic lake located ne...

  11. Two Fiber Optical Fiber Thermometry

    Science.gov (United States)

    Jones, Mathew R.; Farmer, Jeffery T.; Breeding, Shawn P.

    2000-01-01

    An optical fiber thermometer consists of an optical fiber whose sensing tip is given a metallic coating. The sensing tip of the fiber is essentially an isothermal cavity, so the emission from this cavity will be approximately equal to the emission from a blackbody. Temperature readings are obtained by measuring the spectral radiative heat flux at the end of the fiber at two wavelengths. The ratio of these measurements and Planck's Law are used to infer the temperature at the sensing tip. Optical fiber thermometers have high accuracy, excellent long-term stability and are immune to electromagnetic interference. In addition, they can be operated for extended periods without requiring re-calibration. For these reasons. it is desirable to use optical fiber thermometers in environments such as the International Space Station. However, it has recently been shown that temperature readings are corrupted by emission from the fiber when extended portions of the probe are exposed to elevated temperatures. This paper will describe several ways in which the reading from a second fiber can be used to correct the corrupted temperature measurements. The accuracy and sensitivity to measurement uncertainty will be presented for each method.

  12. Preparation and characterization of hydroxyapatite/gelatin composite membranes for immunoisolation

    International Nuclear Information System (INIS)

    Chen, Jyh-Ping; Chang, Feng-Nian

    2012-01-01

    Highlights: ► Cross-linking gelatin in the presence of hydroxyapatite forms composite membranes. ► The membrane was used for immunoisolation and encapsulation of cells. ► Encapsulated islet cells secrete insulin in response to glucose concentrations. ► The membrane is a good candidate for bioartificial pancreas development. - Abstract: Composite membranes are fabricated from hydroxyapatite (HAP) and gelatin for immunoisolation of cells. The films were fabricated by crosslinking 5 wt%, 10 wt%, and 20 wt% gelatin with 1 wt% glutaraldehyde (GA) in the presence of HAP. Fourier transform infrared spectroscopy analysis confirms imide bond formation between GA and gelatin, while the crystal structure of HAP powder remains unchanged from X-ray diffraction analysis. The degree of crosslinking depends on crosslinking time and gelatin concentration. For 5% and 10% gelatin, the degree of crosslinking levels off at 90% within 48 h. From scanning electron microscopy micrographs, the microstructure of the composite membrane depends on the amount of gelatin used in the crosslinking reaction. The mechanical strength of the composite membrane could be enhanced by increasing the gelatin concentration. BET analysis indicates that pore size of the micropores on the surface HAP/gelatin agglomerates decreases with increasing gelatin concentration. However, the macropore, through which diffusion of molecules occurs, is larger at higher gelatin concentrations. The permeability coefficients of different molecules through a HAP/gelatin composite membrane increase with increasing gelatin concentration and is inversely correlated with the molecular weight of the molecule. For immunoisolation of cells, the diffusion of large molecules stimulated by the immune system can be rejected by a chamber constructed from the HAP/gelatin membrane. Insulinoma cells were encapsulated in alginate-poly-L-lysine-alginate microcapsules and enclosed in a HAP/gelatin chamber. The chamber did not impair

  13. Preparation and characterization of hydroxyapatite/gelatin composite membranes for immunoisolation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jyh-Ping, E-mail: jpchen@mail.cgu.edu.tw [Department of Chemical and Materials Engineering, Chang Gung University, 259 Wen Hwa 1st Rd., Kwei-San, Taoyuan 333, Taiwan (China); Chang, Feng-Nian [Department of Chemical and Materials Engineering, Chang Gung University, 259 Wen Hwa 1st Rd., Kwei-San, Taoyuan 333, Taiwan (China)

    2012-12-01

    Highlights: Black-Right-Pointing-Pointer Cross-linking gelatin in the presence of hydroxyapatite forms composite membranes. Black-Right-Pointing-Pointer The membrane was used for immunoisolation and encapsulation of cells. Black-Right-Pointing-Pointer Encapsulated islet cells secrete insulin in response to glucose concentrations. Black-Right-Pointing-Pointer The membrane is a good candidate for bioartificial pancreas development. - Abstract: Composite membranes are fabricated from hydroxyapatite (HAP) and gelatin for immunoisolation of cells. The films were fabricated by crosslinking 5 wt%, 10 wt%, and 20 wt% gelatin with 1 wt% glutaraldehyde (GA) in the presence of HAP. Fourier transform infrared spectroscopy analysis confirms imide bond formation between GA and gelatin, while the crystal structure of HAP powder remains unchanged from X-ray diffraction analysis. The degree of crosslinking depends on crosslinking time and gelatin concentration. For 5% and 10% gelatin, the degree of crosslinking levels off at 90% within 48 h. From scanning electron microscopy micrographs, the microstructure of the composite membrane depends on the amount of gelatin used in the crosslinking reaction. The mechanical strength of the composite membrane could be enhanced by increasing the gelatin concentration. BET analysis indicates that pore size of the micropores on the surface HAP/gelatin agglomerates decreases with increasing gelatin concentration. However, the macropore, through which diffusion of molecules occurs, is larger at higher gelatin concentrations. The permeability coefficients of different molecules through a HAP/gelatin composite membrane increase with increasing gelatin concentration and is inversely correlated with the molecular weight of the molecule. For immunoisolation of cells, the diffusion of large molecules stimulated by the immune system can be rejected by a chamber constructed from the HAP/gelatin membrane. Insulinoma cells were encapsulated in alginate

  14. Flakeboard thickness swelling. Part I, Stress relaxation in a flakeboard mat

    Science.gov (United States)

    R. L. Geimer; J. H. Kwon; J. Bolton

    1998-01-01

    The steam injection schedule best suited for dimensionally stabilizing a flake mat is one in which steam treatment is initiated before the press is closed and is continued at least until the mat attains target thickness. Experiments showed that resinless mats treated with 20 sec of steam at 600 kPa had maximum thickness swelling of 205% compared to 350% for resinless...

  15. Electrospun Nanofiber Scaffolds with Gradations in Fiber Organization

    Science.gov (United States)

    Khandalavala, Karl; Jiang, Jiang; Shuler, Franklin D.; Xie, Jingwei

    2015-01-01

    The goal of this protocol is to report a simple method for generating nanofiber scaffolds with gradations in fiber organization and test their possible applications in controlling cell morphology/orientation. Nanofiber organization is controlled with a new fabrication apparatus that enables the gradual decrease of fiber organization in a scaffold. Changing the alignment of fibers is achieved through decreasing deposition time of random electrospun fibers on a uniaxially aligned fiber mat. By covering the collector with a moving barrier/mask, along the same axis as fiber deposition, the organizational structure is easily controlled. For tissue engineering purposes, adipose-derived stem cells can be seeded to these scaffolds. Stem cells undergo morphological changes as a result of their position on the varied organizational structure, and can potentially differentiate into different cell types depending on their locations. Additionally, the graded organization of fibers enhances the biomimicry of nanofiber scaffolds so they more closely resemble the natural orientations of collagen nanofibers at tendon-to-bone insertion site compared to traditional scaffolds. Through nanoencapsulation, the gradated fibers also afford the possibility to construct chemical gradients in fiber scaffolds, and thereby further strengthen their potential applications in fast screening of cell-materials interaction and interfacial tissue regeneration. This technique enables the production of continuous gradient scaffolds, but it also can potentially produce fibers in discrete steps by controlling the movement of the moving barrier/mask in a discrete fashion. PMID:25938562

  16. Electrospun fibers for high performance anodes in microbial fuel cells. Optimizing materials and architecture

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Shuiliang

    2010-04-15

    A novel porous conducting nanofiber mat (PCNM) with nanostructured polyaniline (nanoPANi) on the fiber surface was successfully prepared by simple oxidative polymerization. The composite PCNM displayed a core/shell structure with highly rough surface. The thickness and the morphology of PANi layer on the electrospun polyamide (PA) fiber surface could be controlled by varying aniline concentration and temperature. The combination of the advantages of electrospinning technique and nanostructured PANi, let the PA/PANi composite PCNM possess more than five good properties, i.e. high conductivity of 6.759 S.m{sup -1}, high specific surface area of 160 m2.g{sup -1}, good strength of 82.88 MPa for mat and 161.75 MPa for highly aligned belts, good thermal properties with 5% weight loss temperature up to 415 C and excellent biocompatibility. In the PA/PANi composite PCNM, PANi is the only conducting component, its conductivity of 6.759 S.m{sup -1} which is measured in dry-state, is not enough for electrode. Moreover, the conductivity decreases in neutral pH environment due to the de-doping of proton. However, the method of spontaneous growth of nanostructured PANi on electrospun fiber mats provides an effective method to produce porous electrically conducting electrospun fiber mats. The combination advantages of nanostructured PANi with the electrospun fiber mats, extends the applications of PANi and electrospun nanofibers, such as chemical- and bio-sensors, actuators, catalysis, electromagnetic shielding, corrosion protection, separation membranes, electro-optic devices, electrochromic devices, tissue engineering and many others. The electrical conductivity of electrospun PCNM with PANi as the only conducting component is too low for application of as anode in microbial fuel cells (MFCs). So, we turn to electrospun carbon fiber due to its high electrical conductivity and environmental stability. The current density is greatly dependent on the microorganism density of anode

  17. Modification of Jute Fibers with Polystyrene via Atom Transfer Radical Polymerization

    DEFF Research Database (Denmark)

    Plackett, David; Jankova, Katja Atanassova; Egsgaard, Helge

    2005-01-01

    Atom transfer radical polymerization (ATRP) was investigated as a method of covalently bonding polystyrene to jute (Corchorus capsularis) and as a possible approach to fiber composites with enhanced properties. Jute fibers were modified with a brominated initiator and subsequently ATRP modified...... to attach polystyrene and then examined using SEM, DSC, TGA, FTIR, XPS, elemental analysis, and Py-GC-MS. These techniques confirmed that polystyrene had been covalently bound to the fibers and consequently ATRP-modified jute fiber mats were used to prepare hot-pressed polystyrene composites. Composite...

  18. MAGNOLOL ENTRAPPED ULTRA-FINE FIBROUS MATS ELECTROSPUN FROM POLY(ETHYLENE GLYCOL)-b-POLY(L-LACTIDE) AND IN VITRO RELEASE

    Institute of Scientific and Technical Information of China (English)

    Hao Wang; Hong-rui Song; Yong Cui; Ying-jie Deng; Xue-si Chen

    2011-01-01

    Ultra-fine fibrous mats with magnolol entrapped have been prepared by electrospinning biodegradable copolymer poly(ethylene glycol) blocked poly(L-lactide). Drug entrapment was perfect which was confirmed by scanning electron microscopy and differential scanning calorimetry. According to in vitro drug release investigation by high performance liquid chromatography, it was found that fibers with 10%, 20% and 30% drug entrapped respect to polymer (mass ratio) presented dramatically different drug release behavior and degradation behavior under the effect of proteinase K. The reason may be that fibers with 10% drug entrapped was more easily affected by enzyme while, to some degree, magnolol in fibers with 20% and 30% entrapped prevented polymer from being degraded by enzyme.

  19. Aspects of the ecology of mat-forming lichens

    Directory of Open Access Journals (Sweden)

    P. D. Crittenden

    2000-03-01

    Full Text Available Lichen species in the genera Cladonia (subgenus Cladina, Cetraria, Stereocaulon and Alectoria are important vegetation components on well-drained terrain and on elevated micro-sites in peatlands in boreal-Arctic regions. These lichens often form closed mats, the component thalli in which grow vertically upwards at the apices and die off in the older basal regions; they are therefore only loosely attached to the underlying soil. This growth habit is relatively unusual in lichens being found in <0.5% of known species. It might facilitate internal nutrienr recycling and higher growth rates and, together with the production of allelochemicals, it might underlie the considerable ecological success of mat-forming lichens; experiments to critically assess the importance of these processes are required. Mat-forming lichens can constitute in excess of 60% of the winter food intake of caribou and reindeer. Accordingly there is a pressing need for data on lichen growth rates, measured as mass increment, in order to help determine the carrying capacity of winter ranges for rhese herbivores and to better predict recovery rates following grazing. Trampling during the snow-free season fragments lichen thalli; mat-forming lichens regenerate very successfully from thallus fragments provided trampling does nor re-occur. Frequent recurrence of trampling creates disturbed habitats from which lichens will rapidly become eliminated consistent with J.P. Grime's CSR strategy theory. Such damage to lichen ground cover has occurred where reindeer or caribou are unable to migrate away from their winter range such as on small islands or where political boundaries have been fenced; it can also occur on summer range that contains a significant lichen component and on winter range where numbers of migrarory animals become excessive. Species of Stereocaulon, and other genera that contain cyanobacteria (most notably Peltigera and Nephroma, are among the principal agents of

  20. Rejoining of cut wounds by engineered gelatin-keratin glue.

    Science.gov (United States)

    Thirupathi Kumara Raja, S; Thiruselvi, T; Sailakshmi, G; Ganesh, S; Gnanamani, A

    2013-08-01

    Rejoining of cut tissue ends of a critical site challenges clinicians. The toxicity, antigenicity, low adhesive strength, flexibility, swelling and cost of the currently employed glue demands an alternative. Engineered gelatin-keratin glue (EGK-glue) described in the present study was found to be suitable for wet tissue approximation. EGK-glue was prepared by engineering gelatin with caffeic acid using EDC and conjugating with keratin by periodate oxidation. UV-visible, (1)H NMR and circular dichroism analyses followed by experiments on gelation time, rheology, gel adhesive strength (in vitro), wet tissue approximation (in vivo), H&E staining of tissue sections at scheduled time intervals and tensile strength of the healed skin were carried out to assess the effectiveness of the EGK-glue in comparison with fibrin glue and cyanoacrylate. Results of UV-visible, NMR and CD analyses confirmed the functionalization and secondary structural changes. Increasing concentration of keratin reduces the gelation time (glue for clinical applications. Tissue approximation property assessed using the incision wound model (Wistar strain) in comparison with cyanoacrylate and fibrin glue suggested, that EGK-glue explicitly accelerates the rejoining of tissue with a 1.86 fold increase in skin tensile strength after healing. Imparting quinone moiety to gelatin-keratin conjugates through caffeic acid and a weaker oxidizing agent provides an adhesive glue with appreciable strength, and hemocompatible, cytocompatible and biodegradable properties, which, rejoin the cut tissue ends effectively. EGK-glue obtained in the present study finds wide biomedical/clinical applications. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. The heterothallic sugarbeet pathogen Cercospora beticola contains exon fragments of both MAT genes that are homogenized by concerted evolution.

    Science.gov (United States)

    Bolton, Melvin D; de Jonge, Ronnie; Inderbitzin, Patrik; Liu, Zhaohui; Birla, Keshav; Van de Peer, Yves; Subbarao, Krishna V; Thomma, Bart P H J; Secor, Gary A

    2014-01-01

    Dothideomycetes is one of the most ecologically diverse and economically important classes of fungi. Sexual reproduction in this group is governed by mating type (MAT) genes at the MAT1 locus. Self-sterile (heterothallic) species contain one of two genes at MAT1 (MAT1-1-1 or MAT1-2-1) and only isolates of opposite mating type are sexually compatible. In contrast, self-fertile (homothallic) species contain both MAT genes at MAT1. Knowledge of the reproductive capacities of plant pathogens are of particular interest because recombining populations tend to be more difficult to manage in agricultural settings. In this study, we sequenced MAT1 in the heterothallic Dothideomycete fungus Cercospora beticola to gain insight into the reproductive capabilities of this important plant pathogen. In addition to the expected MAT gene at MAT1, each isolate contained fragments of both MAT1-1-1 and MAT1-2-1 at ostensibly random loci across the genome. When MAT fragments from each locus were manually assembled, they reconstituted MAT1-1-1 and MAT1-2-1 exons with high identity, suggesting a retroposition event occurred in a homothallic ancestor in which both MAT genes were fused. The genome sequences of related taxa revealed that MAT gene fragment pattern of Cercospora zeae-maydis was analogous to C. beticola. In contrast, the genome of more distantly related Mycosphaerella graminicola did not contain MAT fragments. Although fragments occurred in syntenic regions of the C. beticola and C. zeae-maydis genomes, each MAT fragment was more closely related to the intact MAT gene of the same species. Taken together, these data suggest MAT genes fragmented after divergence of M. graminicola from the remaining taxa, and concerted evolution functioned to homogenize MAT fragments and MAT genes in each species. Published by Elsevier Inc.

  2. Ocular biocompatibility of gelatin microcarriers functionalized with oxidized hyaluronic acid

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Jui-Yang, E-mail: jylai@mail.cgu.edu.tw [Institute of Biochemical and Biomedical Engineering, Chang Gung University, Taoyuan 33302, Taiwan (China); Biomedical Engineering Research Center, Chang Gung University, Taoyuan 33302, Taiwan (China); Center for Tissue Engineering, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan (China); Department of Ophthalmology, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan (China); Department of Materials Engineering, Ming Chi University of Technology, New Taipei City 24301, Taiwan (China); Ma, David Hui-Kang [Center for Tissue Engineering, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan (China); Department of Ophthalmology, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan (China); Department of Chinese Medicine, Chang Gung University, Taoyuan 33302, Taiwan (China)

    2017-03-01

    Given that the presence of aldehyde groups on the oxidized sugar residues may pose toxicity concerns, it is necessary to examine the safety of gelatin microcarriers (GMC) functionalized with oxidized hyaluronic acid (oHA) for potential ophthalmic applications. In this study, the ocular biocompatibility of biopolymer microcarriers was investigated in vitro using primary rabbit corneal cell cultures and in vivo using the anterior chamber of the rabbit eye model. Our results showed that different types of corneal cells including epithelial, stromal, and endothelial cells remain viable and actively proliferate following 2 and 4 days of exposure to test materials. In addition, similar interleukin-6 gene expression levels and comet tail lengths were seen in the presence and absence of biopolymer microcarriers, suggesting no cellular inflammation and genotoxicity. After 7 and 14 days of intracameral injection in the rabbit eyes, both the GMC samples and their counterparts functionalized with oHA were well tolerated in the ocular anterior chamber as demonstrated by slit-lamp biomicroscopy. Clinical observations including specular microscopic examinations, corneal topography, and corneal thickness measurements also showed that the rabbits bearing biopolymer microcarriers exhibit no signs of corneal edema and astigmatism as well as endothelial damage, indicating the absence of tissue response. It is concluded that the GMC materials functionalized with oHA (oxidation level: 10.4 ± 0.9%) are compatible toward corneal cells and ocular anterior segment tissues at a concentration of 10 mg/ml. The information about the effect of coupling of aldehyde-functionalized HA to gelatin on in vitro and in vivo biocompatibility of biopolymer composites can be used as further development of corneal stromal cell microcarriers for tissue engineering applications. - Highlights: • We examine in vitro and in vivo ocular biocompatibility of biopolymer microcarrier. • Gelatin-oxidized HA

  3. Ocular biocompatibility of gelatin microcarriers functionalized with oxidized hyaluronic acid

    International Nuclear Information System (INIS)

    Lai, Jui-Yang; Ma, David Hui-Kang

    2017-01-01

    Given that the presence of aldehyde groups on the oxidized sugar residues may pose toxicity concerns, it is necessary to examine the safety of gelatin microcarriers (GMC) functionalized with oxidized hyaluronic acid (oHA) for potential ophthalmic applications. In this study, the ocular biocompatibility of biopolymer microcarriers was investigated in vitro using primary rabbit corneal cell cultures and in vivo using the anterior chamber of the rabbit eye model. Our results showed that different types of corneal cells including epithelial, stromal, and endothelial cells remain viable and actively proliferate following 2 and 4 days of exposure to test materials. In addition, similar interleukin-6 gene expression levels and comet tail lengths were seen in the presence and absence of biopolymer microcarriers, suggesting no cellular inflammation and genotoxicity. After 7 and 14 days of intracameral injection in the rabbit eyes, both the GMC samples and their counterparts functionalized with oHA were well tolerated in the ocular anterior chamber as demonstrated by slit-lamp biomicroscopy. Clinical observations including specular microscopic examinations, corneal topography, and corneal thickness measurements also showed that the rabbits bearing biopolymer microcarriers exhibit no signs of corneal edema and astigmatism as well as endothelial damage, indicating the absence of tissue response. It is concluded that the GMC materials functionalized with oHA (oxidation level: 10.4 ± 0.9%) are compatible toward corneal cells and ocular anterior segment tissues at a concentration of 10 mg/ml. The information about the effect of coupling of aldehyde-functionalized HA to gelatin on in vitro and in vivo biocompatibility of biopolymer composites can be used as further development of corneal stromal cell microcarriers for tissue engineering applications. - Highlights: • We examine in vitro and in vivo ocular biocompatibility of biopolymer microcarrier. • Gelatin-oxidized HA

  4. The effects of gelatin supplementation prior to cooling on ram semen quality and fertility.

    Science.gov (United States)

    The physical and chemical characteristics of gelatin have been used to justify its inclusion in extenders to preserve the sperm quality and improve results of cervical artificial insemination with cooled semen. The objective of this study was to evaluate the effect of gelatin supplementation in cool...

  5. Effect of dry-heating with pectin on gelatinization properties of sweet ...

    African Journals Online (AJOL)

    Purpose: To evaluate the effect of dry-heating with pectin at different dry heating temperatures, heating times and pH on the gelatinization properties of sweet potato starch. Methods: The gelatinization properties of sweet potato starch - pectin blend were analyzed using a rapid viscosity analyzer (RVA), differential scanning ...

  6. The Role of Bloom Index of Gelatin on the Interaction with Retinal Pigment Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Jui Yang Lai

    2009-08-01

    Full Text Available Biocompatible materials are of considerable interest in the development of cell/drug delivery carriers for therapeutic applications. This paper investigates the effects of the Bloom index of gelatin on its interaction with retinal pigment epithelial (RPE cells. Following two days of culture of ARPE-19 cells with gelatin samples G75-100, G175, and G300, the in vitro biocompatibility was determined by cell proliferation and viability assays, and glutamate uptake measurements, as well as cytokine expression analyses. The mitochondrial dehydrogenase activity in the G300 groups was significantly lower than that of G75-100 and G175 groups. The Live/Dead assays also showed that the gelatin samples G300 induced mild cytotoxicity. In comparison with the treatment of gelatins with low Bloom index, the exposure to high Bloom strength gelatins markedly reduced the glutamate uptake capacity of ARPE-19 cells. One possible explanation for these observations is that the presence of gelatin samples G300 with high viscosity in the medium may affect the nutrient availability to cultured cells. The analyses of pro-inflammatory cytokine IL-6 expression at both mRNA and protein levels showed that the gelatins with low Bloom index caused less cellular inflammatory reaction and had more acceptable biocompatibility than their high Bloom strength counterparts. These findings suggest that the Bloom index gives influence on cellular responses to gelatin materials.

  7. Gelatin Scaffolds with Controlled Pore Structure and Mechanical Property for Cartilage Tissue Engineering.

    Science.gov (United States)

    Chen, Shangwu; Zhang, Qin; Nakamoto, Tomoko; Kawazoe, Naoki; Chen, Guoping

    2016-03-01

    Engineering of cartilage tissue in vitro using porous scaffolds and chondrocytes provides a promising approach for cartilage repair. However, nonuniform cell distribution and heterogeneous tissue formation together with weak mechanical property of in vitro engineered cartilage limit their clinical application. In this study, gelatin porous scaffolds with homogeneous and open pores were prepared using ice particulates and freeze-drying. The scaffolds were used to culture bovine articular chondrocytes to engineer cartilage tissue in vitro. The pore structure and mechanical property of gelatin scaffolds could be well controlled by using different ratios of ice particulates to gelatin solution and different concentrations of gelatin. Gelatin scaffolds prepared from ≥70% ice particulates enabled homogeneous seeding of bovine articular chondrocytes throughout the scaffolds and formation of homogeneous cartilage extracellular matrix. While soft scaffolds underwent cellular contraction, stiff scaffolds resisted cellular contraction and had significantly higher cell proliferation and synthesis of sulfated glycosaminoglycan. Compared with the gelatin scaffolds prepared without ice particulates, the gelatin scaffolds prepared with ice particulates facilitated formation of homogeneous cartilage tissue with significantly higher compressive modulus. The gelatin scaffolds with highly open pore structure and good mechanical property can be used to improve in vitro tissue-engineered cartilage.

  8. Pemisahan krom pada limbah cair industri penyamakan kulit menggunakan gelatin dan flokulan anorganik

    Directory of Open Access Journals (Sweden)

    Sugihartono

    2016-06-01

    Full Text Available ABSTRACT The aim of the study was to determine the ability of gelatin, ferrous sulfate, aluminium sulfate, and combination of gelatin with ferrous sulfate or aluminium sulfate for total chromium content (trivalent chromium and hexavalent chromium separation from tannery wastewater. Reduction of total chromium content in the wastewater was conducted using combination of gelatin and ferrous sulfate or gelatin and aluminium sulfate with a ratio of 4:0; 3:1; 2:2; 1:3; and 0:4 (w/w. The results showed that gelatin, ferrous sulfate, and aluminium sulfate, were able to reduce total chromium content in the wastewater. Combination of gelatin/ferrous sulfate or gelatin/aluminium sulfate as flocculants provide synergistic work in reducing the total chromium content. A 94.75% removal of total chromium content was achieved by combining gelatine and aluminium sulfate with a ratio of 3:1, clearer wastewater, and followed by reduction of degree of turbidity up to 74.47%. The total chromium content after treatment was 0.61 ppm, which met the requirements of wastewater for business and or daily activities especially for tanning industry.

  9. Synthesis of fish scales gelatin-chitosan crosslinked films by gamma irradiation techniques

    International Nuclear Information System (INIS)

    Erizal; Perkasa, D.P.; Abbas, B.; Sulistioso, G.S.

    2013-01-01

    Gelatin is an important component of fish scales. Nowadays, attention has increased concerning the application of gelatin.The aim of this research was to improve the mechanical properties of gelatin produced from fish scales, which concurrently could increase the usefulness of fish scales. Gelatin (G) is prone to degrade or dissolve in water at room temperature, therefore to enhance its lifetime, it has to be modified with other compound such as chitosan. Chitosan (Cs) is a biodegradable polymer, which has biocompatibility and antibacterial properties. In this study, gelatin solution was mixed with chitosan solution in various ratios (G/Cs: 100/0, 75/25, 50/50, 25/75, 0/100), casted at room temperature to make composite films, then tested for the effectiveness of various gamma irradiation doses (10-40 kGy) for crosslinking of the two polymers. Chemical changes of the films were measured by FT-IR, gel fractions were determined by gravimetry, and mechanical properties were determined by tensile strength and elongation at break using universal testing machine. At optimum conditions ( 30 kGy and 75% Cs), the gel fraction, tensile strength, and elongation at break were higher leading to a stronger composite films as compared to the gelatin film. FTIR spectral analysis showed that gelatin and chitosan formed a crosslinked network. It was concluded that G-Cs films prepared by gamma irradiation have improved their mechanical properties than the gelatin itself. (author)

  10. SIFAT FISIKO-KIMIA GELATIN KULIT IKAN BELUT DAN LELE PADA KEADAAN SEGAR DAN KERING

    Directory of Open Access Journals (Sweden)

    Hafni Rahmawati

    2016-06-01

    The first stage of the research was raw material preparation (fresh and dry fish skin soaked in aquadest for 4 hours. Fish skin extracted using 0,05 M acetic acid for 10 hours, washed in water and then extracted using aquadest at 80OC for 2 hours to get gelatin liquid, the liquid was filtrated. Filtrat was dried in cabinet dryer at 55OC for  48 hours to get gelatin layers, and then blended to get gelatin granule. The results were showing viscosity of gelatin from dry fish skin as same as from fresh fish skin, gel strength and melting point of gelatin from dry fish skin was higher than from fresh fish skin. Influence of fish skin drying was increase turbidity and color of gelatin. The best gelatin was ekstracted from dry skin swamp ell with viscosity 6,65 cps, gel strength 206,30 Bloom, melting point 22,33OC. Gelatin from fresh skin swamp ell was the best turbidity 1,65 ntu and color (L = 41,87, a = 8,90, b = 27,27.

  11. Biomimetic Synthesis of Gelatin Polypeptide-Assisted Noble-Metal Nanoparticles and Their Interaction Study

    Science.gov (United States)

    Liu, Ying; Liu, Xiaoheng; Wang, Xin

    2011-12-01

    Herein, the generation of gold, silver, and silver-gold (Ag-Au) bimetallic nanoparticles was carried out in collagen (gelatin) solution. It first showed that the major ingredient in gelatin polypeptide, glutamic acid, acted as reducing agent to biomimetically synthesize noble metal nanoparticles at 80°C. The size of nanoparticles can be controlled not only by the mass ratio of gelatin to gold ion but also by pH of gelatin solution. Interaction between noble-metal nanoparticles and polypeptide has been investigated by TEM, UV-visible, fluorescence spectroscopy, and HNMR. This study testified that the degradation of gelatin protein could not alter the morphology of nanoparticles, but it made nanoparticles aggregated clusters array (opposing three-dimensional α-helix folding structure) into isolated nanoparticles stabilized by gelatin residues. This is a promising merit of gelatin to apply in the synthesis of nanoparticles. Therefore, gelatin protein is an excellent template for biomimetic synthesis of noble metal/bimetallic nanoparticle growth to form nanometer-sized device.

  12. Structure evolution of gelatin particles induced by pH and ionic strength.

    Science.gov (United States)

    Xu, Jing; Li, Tianduo; Tao, Furong; Cui, Yuezhi; Xia, Yongmei

    2013-03-01

    Microstructure of gelatin particles played a key role in determining the physicochemical properties of gelatin. Ionic strength and pH as systematic manners were considered to affect gelatin particles structure on the micrometer scale. Scanning electron microscopy was used for depicting the morphologies of gelatin particles. Increasing pH to 10.0 or decreasing pH to 4.0, spherical, spindle, and irregular aggregates of gelatin particles at 2, 6, 10, and 14% solution (w/w) were all transformed to spindle aggregates. When NaCl was added to the system, the molecular chains of gelatin possibly rearranged themselves in a stretched state, and the ribbon aggregates was observed. The structural transitions of gelatin aggregates were strongly depended on the electrostatic repulsion. In the gelatin-sodium dodecyl sulfate (SDS) case, the micrometer scale of aggregates was larger and the different degrees of cross-links were induced through hydrophobic interaction and electrostatic repulsion. Copyright © 2012 Wiley Periodicals, Inc.

  13. Combined gelatin-chondroitin sulfate hydrogels for controlled release of cationic antibacterial proteins

    NARCIS (Netherlands)

    Kuijpers, A. J.; Engbers, G. H. M.; Meyvis, T. K. L.; de Smedt, S. S. C.; Demeester, J.; Krijgsveld, J.; Zaat, S. A. J.; Dankert, J.; Feijen, J.

    2000-01-01

    Chemically cross-linked gelatin-chondroitin sulfate (ChS) hydrogels were prepared for the controlled release of small cationic proteins. The amount of chondroitin sulfate in the gelatin gels varied between 0 and 20 wt %. The chemical cross-link density, the degree of swelling, and the rheological

  14. The microstructure and rheology of homogeneous and phase separated gelatine gels

    NARCIS (Netherlands)

    Ersch, Carsten; Linden, van der Erik; Venema, Paul; Martin, Anneke

    2016-01-01

    The gelation of gelatine in mixtures of gelatine (type A or type B) and globular proteins (Whey Protein Isolate (WPI), Whey Protein Aggregates (WPA) and Soy Protein Isolate (SPI)) was studied with a focus on their phase separation during gelation. Confocal laser scanning microscopy, visual

  15. The microstructure and rheology of homogeneous and phase separated gelatine gels

    NARCIS (Netherlands)

    Ersch, C.; Linden, E. van der; Venema, P.; Martin, A.

    2016-01-01

    The gelation of gelatine in mixtures of gelatine (type A or type B) and globular proteins (Whey Protein Isolate (WPI), Whey Protein Aggregates (WPA) and Soy Protein Isolate (SPI)) was studied with a focus on their phase separation during gelation. Confocal laser scanning microscopy, visual

  16. Engineering blood vessels through micropatterned co-culture of vascular endothelial and smooth muscle cells on bilayered electrospun fibrous mats with pDNA inoculation.

    Science.gov (United States)

    Liu, Yaowen; Lu, Jinfu; Li, Huinan; Wei, Jiaojun; Li, Xiaohong

    2015-01-01

    Although engineered blood vessels have seen important advances during recent years, proper mechanical strength and vasoactivity remain unsolved problems. In the current study, micropatterned fibrous mats were created to load smooth muscle cells (SMC), and a co-culture with endothelial cells (EC) was established through overlaying on an EC-loaded flat fibrous mat to mimic the layered structure of a blood vessel. A preferential distribution of SMC was determined in the patterned regions throughout the fibrous scaffolds, and aligned fibers in the patterned regions provided topological cues to guide the orientation of SMC with intense actin filaments and extracellular matrix (ECM) production in a circumferential direction. Plasmid DNA encoding basic fibroblast growth factors and vascular endothelial growth factor were integrated into electrospun fibers as biological cues to promote SMC infiltration into fibrous mats, and the viability and ECM production of both EC and SMC. The layered fibrous mats with loaded EC and SMC were wrapped into a cylinder, and engineered vessels were obtained with compact EC and SMC layers after co-culture for 3 months. Randomly oriented ECM productions of EC formed a continuous endothelium covering the entire lumenal surface, and a high alignment of ECM was shown in the circumferential direction of SMC layers. The tensile strength, strain at failure and suture retention strength were higher than those of the human femoral artery, and the burst pressure and radial compliance were in the same range as the human saphenous vein, indicating potential as blood vessel substitutes for transplantation in vivo. Thus, the establishment of topographical cues and biochemical signals in fibrous scaffolds demonstrates advantages in modulating cellular behavior and organization found in complex multicellular tissues. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  17. Preparation of gelatin-assisted polypyrrole-poly(3,4-ethylenedioxythiophene) composites

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Eun Jin; Male, Umashankar; Huh, Do Sung [Dept.of Chemistry and Nanosystem Engineering, Center for Nano Manufacturing, Inje University, Kimhae (Korea, Republic of)

    2016-11-15

    Conductive polymer composite was synthesized by the polymerization of pyrrole with 3,4-ethylenedioxythiophene using ammonium persulfate as an oxidant with different concentrations of gelatin dispersed in aqueous medium along with the polymerization. Differently from pure polypyrrole–poly(3,4-ethylenedioxythiophene) (PPy–PEDOT) copolymer, the gelatin-assisted composites showed good solubility in aqueous media. The prepared PPy–PEDOT/gelatin composites were identified with Fourier-transform infrared, UV–visible spectroscopy, and X-ray diffraction. Morphological analysis and temperature-dependent direct current conductivity of PPy–PEDOT/gelatin composites were carried out. Obtained results revealed that added gelatin greatly increased conductivity due to the improved mobility of charge carriers.

  18. Investigation of Gelatin Polypeptides of Jellyfish (Rhopilema esculentum for Their Antioxidant Activity in vitro

    Directory of Open Access Journals (Sweden)

    Yong-Liang Zhuang

    2010-01-01

    Full Text Available Jellyfish gelatin was hydrolyzed by different proteases to obtain antioxidative polypeptides. The gelatin hydrolysate obtained by progressive hydrolysis using trypsin and Properase E exhibited the highest hydrolysis degree and antioxidant activity. Three series of gelatin polypeptides (SCP1, SCP2 and SCP3 were obtained by ultrafiltrating the gelatin hydrolysate through molecular mass cut-off membranes of 10, 6 and 2 kDa, respectively. Amino acid composition analysis showed that SCP3 had the highest total hydrophobic amino acid content. The in vitro antioxidant tests demonstrated that SCP2 had the strongest hydroxyl radical and hydrogen peroxide scavenging activities and metal chelating ability, while SCP3 showed the highest reducing power, antioxidant activity in linoleic acid emulsion system and superoxide anion radical scavenging activity. The results support the feasibility of jellyfish gelatin as a natural antioxidant polypeptide provider, and enzymatic hydrolysis and ultrafiltration could be potent future processing technologies to utilize the abundant jellyfish resource.

  19. Thermodynamics and phase transformations: the selected works of Mats Hillert

    International Nuclear Information System (INIS)

    Agren, J.; Brechet, Y.; Hutchinson, Ch.; Purdy, G.

    2006-01-01

    For over half a century, Mats Hillert has contributed greatly to the science of materials. He is widely known and respected as an innovator and an educator, a scientist with an enormous breadth of interest and depth of insight. In acknowledgment of his many contributions, a conference was held in Stockholm in December 2004 to mark his eightieth birthday. This volume was conceived prior to, and publicly announced during the conference. The difficult choice of twenty-four papers from a publication list of more than three hundred was carried out in consultation with Mats. He also suggested or approved the scientists who would be invited to write a brief introduction to each paper. A brief reading of the topics of the selected papers and their introductions reveals something of their range and depth. Several early selections (for example, those on 'The Role of Interfacial Energy during Solid State Phase Transformations', and 'A Solid-Solution Model for Inhomogeneous Systems') contained seminal material that established Mats as a leading figure in the study of phase transformations in solids. Others established his presence in the areas of solidification and computational thermodynamics. A review of his full publication list shows that he has consistently built upon those early foundational papers, and maintained a dominant position in those fields. Although many of his contributions have been of a theoretical nature, he has always maintained a close contact with experiment, and indeed, he has designed numerous critical experiments. This volume represents a judicious sampling of Mats Hillert's extensive body of work; it is necessarily incomplete, but it is hoped and expected that it will prove useful to students of materials science and engineering at all levels, and that it will inspire the further study and appreciation of his many contributions. (authors)

  20. Accuracy of Jump-Mat Systems for Measuring Jump Height.

    Science.gov (United States)

    Pueo, Basilio; Lipinska, Patrycja; Jiménez-Olmedo, José M; Zmijewski, Piotr; Hopkins, Will G

    2017-08-01

    Vertical-jump tests are commonly used to evaluate lower-limb power of athletes and nonathletes. Several types of equipment are available for this purpose. To compare the error of measurement of 2 jump-mat systems (Chronojump-Boscosystem and Globus Ergo Tester) with that of a motion-capture system as a criterion and to determine the modifying effect of foot length on jump height. Thirty-one young adult men alternated 4 countermovement jumps with 4 squat jumps. Mean jump height and standard deviations representing technical error of measurement arising from each device and variability arising from the subjects themselves were estimated with a novel mixed model and evaluated via standardization and magnitude-based inference. The jump-mat systems produced nearly identical measures of jump height (differences in means and in technical errors of measurement ≤1 mm). Countermovement and squat-jump height were both 13.6 cm higher with motion capture (90% confidence limits ±0.3 cm), but this very large difference was reduced to small unclear differences when adjusted to a foot length of zero. Variability in countermovement and squat-jump height arising from the subjects was small (1.1 and 1.5 cm, respectively, 90% confidence limits ±0.3 cm); technical error of motion capture was similar in magnitude (1.7 and 1.6 cm, ±0.3 and ±0.4 cm), and that of the jump mats was similar or smaller (1.2 and 0.3 cm, ±0.5 and ±0.9 cm). The jump-mat systems provide trustworthy measurements for monitoring changes in jump height. Foot length can explain the substantially higher jump height observed with motion capture.

  1. Alpha Matting with KL-Divergence Based Sparse Sampling.

    Science.gov (United States)

    Karacan, Levent; Erdem, Aykut; Erdem, Erkut

    2017-06-22

    In this paper, we present a new sampling-based alpha matting approach for the accurate estimation of foreground and background layers of an image. Previous sampling-based methods typically rely on certain heuristics in collecting representative samples from known regions, and thus their performance deteriorates if the underlying assumptions are not satisfied. To alleviate this, we take an entirely new approach and formulate sampling as a sparse subset selection problem where we propose to pick a small set of candidate samples that best explains the unknown pixels. Moreover, we describe a new dissimilarity measure for comparing two samples which is based on KLdivergence between the distributions of features extracted in the vicinity of the samples. The proposed framework is general and could be easily extended to video matting by additionally taking temporal information into account in the sampling process. Evaluation on standard benchmark datasets for image and video matting demonstrates that our approach provides more accurate results compared to the state-of-the-art methods.

  2. Phenotypic variation and characterization of mutant matting in shiitake

    International Nuclear Information System (INIS)

    Ibrahim Mahmood; Azhar Mohamad

    2016-01-01

    Shiitake (Lentinula edodes) is an edible mushroom that has many uses such as: pharmaceutical, nutraceutical and cosmeceutical industries. In this study, we will induce Shiitake to create the genetic variation via exposing the spores of shiitake to gamma (γ) ray at different doses (0-700 Gy) then make the matting between two different monokaryon mycelium (MM). potato dextrose agar (PDA), this media will be used for spore germination and monokaryon mycelium subculturing during this study. The compatibility of the matting will be observed macroscopically (observing on the plates of PDA) and microscopically (by observing the clamps test under the microscope (Olympus brand)). The finding of this study, there is no significant changing in the growth performance of irradiated monokaryon mycelium in comparing with non-irradiated mycelium. From 108 matting only 15 were compatibles. This study, the physical mutagen will be used followed by mating as a normal stage of life cycle for creating potential strain of shiitake with alteration in phenotypic characterization of dikaryon mycelium (DM) as a compatible mating for two MM. (author)

  3. Simulated Carbon Cycling in a Model Microbial Mat.

    Science.gov (United States)

    Decker, K. L.; Potter, C. S.

    2006-12-01

    We present here the novel addition of detailed organic carbon cycling to our model of a hypersaline microbial mat ecosystem. This ecosystem model, MBGC (Microbial BioGeoChemistry), simulates carbon fixation through oxygenic and anoxygenic photosynthesis, and the release of C and electrons for microbial heterotrophs via cyanobacterial exudates and also via a pool of dead cells. Previously in MBGC, the organic portion of the carbon cycle was simplified into a black-box rate of accumulation of simple and complex organic compounds based on photosynthesis and mortality rates. We will discuss the novel inclusion of fermentation as a source of carbon and electrons for use in methanogenesis and sulfate reduction, and the influence of photorespiration on labile carbon exudation rates in cyanobacteria. We will also discuss the modeling of decomposition of dead cells and the ultimate release of inorganic carbon. The detailed modeling of organic carbon cycling is important to the accurate representation of inorganic carbon flux through the mat, as well as to accurate representation of growth models of the heterotrophs under different environmental conditions. Because the model ecosystem is an analog of ancient microbial mats that had huge impacts on the atmosphere of early earth, this MBGC can be useful as a biological component to either early earth models or models of other planets that potentially harbor life.

  4. Hydroponic root mats for wastewater treatment-a review.

    Science.gov (United States)

    Chen, Zhongbing; Cuervo, Diego Paredes; Müller, Jochen A; Wiessner, Arndt; Köser, Heinz; Vymazal, Jan; Kästner, Matthias; Kuschk, Peter

    2016-08-01

    Hydroponic root mats (HRMs) are ecotechnological wastewater treatment systems where aquatic vegetation forms buoyant filters by their dense interwoven roots and rhizomes, sometimes supported by rafts or other floating materials. A preferential hydraulic flow is created in the water zone between the plant root mat and the bottom of the treatment system. When the mat touches the bottom of the water body, such systems can also function as HRM filter; i.e. the hydraulic flow passes directly through the root zone. HRMs have been used for the treatment of various types of polluted water, including domestic wastewater; agricultural effluents; and polluted river, lake, stormwater and groundwater and even acid mine drainage. This article provides an overview on the concept of applying floating HRM and non-floating HRM filters for wastewater treatment. Exemplary performance data are presented, and the advantages and disadvantages of this technology are discussed in comparison to those of ponds, free-floating plant and soil-based constructed wetlands. Finally, suggestions are provided on the preferred scope of application of HRMs.

  5. Effects of chicken by-product gelatin on the physicochemical properties and texture of chocolate spread.

    Science.gov (United States)

    Almeida, Poliana Fernandes; Lannes, Suzana Caetano da Silva

    2017-10-01

    Chocolate spread has a fat-based formulation and the application of gelatin as a fat replacement is related to the demand for healthier foods. The aim of this study was to evaluate the influence of gelatin as a by-product from the poultry industry in the fat replacement of chocolate spread. Vegetable fat was replaced (15, 25, 50, 75, and 100%) with gelatin (0.3, 0.5, 0.8, 1.0, and 1.2%) using a central composite rotatable design and the effects were evaluated by a response surface methodology. Formulations with a greater proportion of fat were lighter, of higher volume and lower density. As expected, water activity was intensified in low-fat formulations. The consistency was controlled mainly by the properties of the gelatin phase. The formulations with 50 and 75% fat replacement and 0.5-1.0% gelatin had satisfactory spreadability at 10C. All formulations were spreadable at 20C. Low-fat samples with low gelatin concentrations, at 30C, had very low consistency. Statistically, the properties were significantly influenced by the factors analyzed according to the mathematical models. Although several studies have been conducted on obtaining alternative gelatin sources for mammals, the extracted gelatin from poultry by-product is still little explored and the knowledge on the application in food products, particularly in complex systems such as emulsions, has not been well established. The development of a low-fat food should take into account the complexity of the system involved, such as the emulsion spreads. The incorporation of gelatin in aqueous solution is a challenging task because the physical properties and the rheological behavior can be strongly influenced. Given the nutritional and functional properties of the gelatin and chocolate and its wide acceptability among the consumers, the incorporation of these two ingredients in the development of a new product sets up a promising study. © 2016 Wiley Periodicals, Inc.

  6. Evaluation of cross-linked gelatin membranes as delivery carriers for retinal sheets

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Jui-Yang, E-mail: jylai@mail.cgu.edu.tw [Institute of Biochemical and Biomedical Engineering, Chang Gung University, Taoyuan, 33302 Taiwan (China); Biomedical Engineering Research Center, Chang Gung University, Taoyuan, 33302 Taiwan (China); Molecular Medicine Research Center, Chang Gung University, Taoyuan, 33302 Taiwan (China); Li, Ya-Ting [Institute of Biochemical and Biomedical Engineering, Chang Gung University, Taoyuan, 33302 Taiwan (China)

    2010-06-15

    The delivery of intact sheet transplants to the subretinal space can prevent cell loss that is generally associated with the injection of cell suspensions or cell aggregates. The aim of this study was to develop chemically modified gelatin matrices that enhance the delivery efficiency and analyze whether the gelatin membranes cross-linked with 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) can be considered as potential carriers for retinal sheets. The characteristics of EDC cross-linked gelatin membranes were determined by mechanical and in vitro degradation tests, melting point measurements, cell proliferation assays, cytokine expression analyses, and tissue delivery studies. Gelatin membranes without cross-linking and glutaraldehyde cross-linked gelatin samples were used for comparison. Results of this study indicated that introduction of cross-links is capable of rendering the gelatin network more stable against mechanical stresses and deformations as well as rapid hydrolysis during intraocular delivery of delicate tissue sheets. In comparison with the glutaraldehyde treated samples, the EDC cross-linked gelatin membranes showed a better degradation profile and a relatively higher cytocompatibility. In addition, after EDC cross-linking, the gelatin matrices having an acceptable melting point could be used for the fabrication of a sandwich-like carrier with a high transfer and encapsulation efficiency. These findings suggest that the cross-linking agent type gives an influence on delivery functionality of gelatin membranes. In summary, the EDC cross-linked gelatin is an ideal candidate for use as a carrier material in retinal sheet delivery applications.

  7. Application of Bio-digestion for Capsule Gelatin-- From the Pharmaceutical Wastes to the Manure

    Science.gov (United States)

    Pan, C.; Huang, S.; Chang, Y.; Wen, J.

    2013-12-01

    The purpose of this study was to bio-digest the capsule gelatin from the waste of pharmaceutical processes such as cutting and stamping for capsule shells producing. We screened soil bacterial flora for capsule gelatin biolysis, and found the most competent one named Yuntech-7. A 15% (w/w) of capsule gelatin could fully digested by Yuntech-7 for 3 days growth with an N-limited medium in a 37°C incubator. In order to recycle and reuse the gelatin waste, the different percentages of capsule gelatin were co-composted with the vegetable residues to produce manure in an anaerobic fermentation by an extra Yuntech-7 inoculation. After 14 days incubation, we collected the filtrate to examine the contents of N, P, and K. The data shows that the P and K keep the same value by roughly between the blank and the control sets, but the total N values were approximately a 5-fold increase in 20% and a 10-fold increase in 40% of capsule gelatin integrated. We suggested that the capsule gelatin was majorly decomposed by Yuntech-7, because the total N value was no observable change in the capsule gelatin and vegetable residues co-compost with a Yuntech-7-free condition. We also performed some field tests using the capsule gelatin generated liquid manure, and the preliminary test shows the plants got great benefits on culture size and in environmental resistance. In conclusion, the process in bio-digestion of waste capsule gelatin by soil bacteria, Yuntech-7, was produced a valuable manure not only aliment the plants but also complement the soil bacterial populations.

  8. Evaporation-based method for preparing gelatin foams with aligned tubular pore structures

    International Nuclear Information System (INIS)

    Frazier, Shane D.; Srubar, Wil V.

    2016-01-01

    Gelatin-based foams with aligned tubular pore structures were prepared via liquid-to-gas vaporization of tightly bound water in dehydrated gelatin hydrogels. This study elucidates the mechanism of the foaming process by investigating the secondary (i.e., helical) structure, molecular interactions, and water content of gelatin films before and after foaming using X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry and thermogravimetric analysis (TGA), respectively. Experimental data from gelatin samples prepared at various gelatin-to-water concentrations (5–30 wt.%) substantiate that resulting foam structures are similar in pore diameter (approximately 350 μm), shape, and density (0.05–0.22 g/cm"3) to those fabricated using conventional methods (e.g., freeze-drying). Helical structures were identified in the films but were not evident in the foamed samples after vaporization (~ 150 °C), suggesting that the primary foaming mechanism is governed by the vaporization of water that is tightly bound in secondary structures (i.e., helices, β-turns, β-sheets) that are present in dehydrated gelatin films. FTIR and TGA data show that the foaming process leads to more disorder and reduced hydrogen bonding to hydroxyl groups in gelatin and that no thermal degradation of gelatin occurs before or after foaming. - Highlights: • A new method is presented for fabricating gelatin foams with aligned, tubular pores. • Gelatin hydrogels were dehydrated then heated to 150 °C to induce foaming. • Vaporization of tightly (vs. loosely) bound water is the primary foaming mechanism • Foaming induced no thermal degradation but caused disorder in secondary structures • Foam microstructures are similar to those prepared using conventional methods.

  9. Evaporation-based method for preparing gelatin foams with aligned tubular pore structures

    Energy Technology Data Exchange (ETDEWEB)

    Frazier, Shane D.; Srubar, Wil V., E-mail: wsrubar@colorado.edu

    2016-05-01

    Gelatin-based foams with aligned tubular pore structures were prepared via liquid-to-gas vaporization of tightly bound water in dehydrated gelatin hydrogels. This study elucidates the mechanism of the foaming process by investigating the secondary (i.e., helical) structure, molecular interactions, and water content of gelatin films before and after foaming using X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry and thermogravimetric analysis (TGA), respectively. Experimental data from gelatin samples prepared at various gelatin-to-water concentrations (5–30 wt.%) substantiate that resulting foam structures are similar in pore diameter (approximately 350 μm), shape, and density (0.05–0.22 g/cm{sup 3}) to those fabricated using conventional methods (e.g., freeze-drying). Helical structures were identified in the films but were not evident in the foamed samples after vaporization (~ 150 °C), suggesting that the primary foaming mechanism is governed by the vaporization of water that is tightly bound in secondary structures (i.e., helices, β-turns, β-sheets) that are present in dehydrated gelatin films. FTIR and TGA data show that the foaming process leads to more disorder and reduced hydrogen bonding to hydroxyl groups in gelatin and that no thermal degradation of gelatin occurs before or after foaming. - Highlights: • A new method is presented for fabricating gelatin foams with aligned, tubular pores. • Gelatin hydrogels were dehydrated then heated to 150 °C to induce foaming. • Vaporization of tightly (vs. loosely) bound water is the primary foaming mechanism • Foaming induced no thermal degradation but caused disorder in secondary structures • Foam microstructures are similar to those prepared using conventional methods.

  10. Determination of 210Po in tea, mat and their infusions and its annual intake by Syrians

    International Nuclear Information System (INIS)

    Al-Masri, M.S.; Nashawati, A.; Amin, Y.; Al-Akel, B.

    2004-01-01

    Polonium-210 was determined in 34 kinds of imported tea and 9 kinds of mat collected from the Syrian local market. The 210 Po concentration was found to vary from 5.5 to 39 Bq x kg -1 and 47 to 82 Bq x kg -1 in tea and mat samples, respectively. In addition 210 Po was also determined in tea and mat infusions where different infusion conditions have been examined: amount, temperature and infusion time. The results have shown that the amount of 210 Po transferred from tea and mat leaves to the aqueous extract ranged from 9 to 21% and 3 to 15%, respectively. The annual intake of 210 Po by Syrians due to tea consumption and mat infusions was calculated and found to be 9 Bq and 151 Bq for tea and mat respectively: washing of mat with warm water is recommended before preparation the infusions to decrease the annual intake of 210 Po. (author)

  11. Mucoadhesive electrospun chitosan-based nanofibre mats for dental caries prevention.

    Science.gov (United States)

    Samprasit, Wipada; Kaomongkolgit, Ruchadaporn; Sukma, Monrudee; Rojanarata, Theerasak; Ngawhirunpat, Tanasait; Opanasopit, Praneet

    2015-03-06

    The mucoadhesive electrospun nanofibre mats were developed using chitosan (CS) and thiolated chitosan (CS-SH) as mucoadhesive polymers. Garcinia mangostana (GM) extract was incorporated into nanofibre mats. The antibacterial activity in the single and combined agents was evaluated against dental caries pathogens. The morphology of mats was observed using SEM. The mats were evaluated for GM extract amount, mucoadhesion, in vitro release, antibacterial activity and cytotoxicity. The mucoadhesion and antibacterial activity were determined in healthy human volunteers. The prepared mats were in nanoscale with good physical and mucoadhesive properties. The CS-SH caused the higher mucoadhesion. All mats rapidly released active substances, which had the synergistic antibacterial activity. In addition, the reduction of bacteria and good mucoadhesion in the oral cavity occurred without cytotoxicity. The results suggest that mats have the potential to be mucoadhesive dosage forms to maintain oral hygiene by reducing the bacterial growth that causes the dental caries. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Fabrication of chemically cross-linked porous gelatin matrices.

    Science.gov (United States)

    Bozzini, Sabrina; Petrini, Paola; Altomare, Lina; Tanzi, Maria Cristina

    2009-01-01

    The aim of this study was to chemically cross-link gelatin, by reacting its free amino groups with an aliphatic diisocyanate. To produce hydrogels with controllable properties, the number of reacting amino groups was carefully determined. Porosity was introduced into the gelatin-based hydrogels through the lyophilization process. Porous and non-porous matrices were characterized with respect to their chemical structure, morphology, water uptake and mechanical properties. The physical, chemical and mechanical properties of the porous matrices are related to the extent of their cross-linking, showing that they can be controlled by varying the reaction parameters. Water uptake values (24 hours) vary between 160% and 200% as the degree of cross-linking increases. The flexibility of the samples also decreases by changing the extent of cross-linking. Young's modulus shows values between 0.188 KPa, for the highest degree, and 0.142 KPa for the lowest degree. The matrices are potential candidates for use as tissue-engineering scaffolds by modulating their physical chemical properties according to the specific application.

  13. Studying Microbial Mat Functioning Amidst "Unexpected Diversity": Methodological Approaches and Initial Results from Metatranscriptomes of Mats Over Diel cycles, iTags from Long Term Manipulations, and Biogeochemical Cycling in Simplified Microbial Mats Constructed from Cultures

    Science.gov (United States)

    Bebout, B.; Bebout, L. E.; Detweiler, A. M.; Everroad, R. C.; Lee, J.; Pett-Ridge, J.; Weber, P. K.

    2014-12-01

    Microbial mats are famously amongst the most diverse microbial ecosystems on Earth, inhabiting some of the most inclement environments known, including hypersaline, dry, hot, cold, nutrient poor, and high UV environments. The high microbial diversity of microbial mats makes studies of microbial ecology notably difficult. To address this challenge, we have been using a combination of metagenomics, metatranscriptomics, iTags and culture-based simplified microbial mats to study biogeochemical cycling (H2 production, N2 fixation, and fermentation) in microbial mats collected from Elkhorn Slough, Monterey Bay, California. Metatranscriptomes of microbial mats incubated over a diel cycle have revealed that a number of gene systems activate only during the day in Cyanobacteria, while the remaining appear to be constitutive. The dominant cyanobacterium in the mat (Microcoleus chthonoplastes) expresses several pathways for nitrogen scavenging undocumented in cultured strains, as well as the expression of two starch storage and utilization cycles. Community composition shifts in response to long term manipulations of mats were assessed using iTags. Changes in community diversity were observed as hydrogen fluxes increased in response to a lowering of sulfate concentrations. To produce simplified microbial mats, we have isolated members of 13 of the 15 top taxa from our iTag libraries into culture. Simplified microbial mats and simple co-cultures and consortia constructed from these isolates reproduce many of the natural patterns of biogeochemical cycling in the parent natural microbial mats, but against a background of far lower overall diversity, simplifying studies of changes in gene expression (over the short term), interactions between community members, and community composition changes (over the longer term), in response to environmental forcing.

  14. Effect of carbon nanotubes upon emissions from cutting and sanding carbon fiber-epoxy composites

    Energy Technology Data Exchange (ETDEWEB)

    Heitbrink, William A. [LMK OSH Consulting LLC (United States); Lo, Li-Ming, E-mail: LLo@cdc.gov [Centers for Disease Control and Prevention (CDC), Division of Applied Research and Technology, National Institute for Occupational Safety and Health (NIOSH) (United States)

    2015-08-15

    Carbon nanotubes (CNTs) are being incorporated into structural composites to enhance material strength. During fabrication or repair activities, machining nanocomposites may release CNTs into the workplace air. An experimental study was conducted to evaluate the emissions generated by cutting and sanding on three types of epoxy-composite panels: Panel A containing graphite fibers, Panel B containing graphite fibers and carbon-based mat, and Panel C containing graphite fibers, carbon-based mat, and multi-walled CNTs. Aerosol sampling was conducted with direct-reading instruments, and filter samples were collected for measuring elemental carbon (EC) and fiber concentrations. Our study results showed that cutting Panel C with a band saw did not generate detectable emissions of fibers inspected by transmission electron microscopy but did increase the particle mass, number, and EC emission concentrations by 20–80 % compared to Panels A and B. Sanding operation performed on two Panel C resulted in fiber emission rates of 1.9 × 10{sup 8} and 2.8 × 10{sup 6} fibers per second (f/s), while no free aerosol fibers were detected from sanding Panels A and B containing no CNTs. These free CNT fibers may be a health concern. However, the analysis of particle and EC concentrations from these same samples cannot clearly indicate the presence of CNTs, because extraneous aerosol generation from machining the composite epoxy material increased the mass concentrations of the EC.

  15. Effect of carbon nanotubes upon emissions from cutting and sanding carbon fiber-epoxy composites

    International Nuclear Information System (INIS)

    Heitbrink, William A.; Lo, Li-Ming

    2015-01-01

    Carbon nanotubes (CNTs) are being incorporated into structural composites to enhance material strength. During fabrication or repair activities, machining nanocomposites may release CNTs into the workplace air. An experimental study was conducted to evaluate the emissions generated by cutting and sanding on three types of epoxy-composite panels: Panel A containing graphite fibers, Panel B containing graphite fibers and carbon-based mat, and Panel C containing graphite fibers, carbon-based mat, and multi-walled CNTs. Aerosol sampling was conducted with direct-reading instruments, and filter samples were collected for measuring elemental carbon (EC) and fiber concentrations. Our study results showed that cutting Panel C with a band saw did not generate detectable emissions of fibers inspected by transmission electron microscopy but did increase the particle mass, number, and EC emission concentrations by 20–80 % compared to Panels A and B. Sanding operation performed on two Panel C resulted in fiber emission rates of 1.9 × 10 8 and 2.8 × 10 6 fibers per second (f/s), while no free aerosol fibers were detected from sanding Panels A and B containing no CNTs. These free CNT fibers may be a health concern. However, the analysis of particle and EC concentrations from these same samples cannot clearly indicate the presence of CNTs, because extraneous aerosol generation from machining the composite epoxy material increased the mass concentrations of the EC

  16. Electrospun Zein Fibers Incorporating Poly(glycerol sebacate for Soft Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Lena Vogt

    2018-03-01

    Full Text Available For biomedical applications such as soft tissue engineering, plant proteins are becoming increasingly attractive. Zein, a class of prolamine proteins found in corn, offers excellent properties for application in the human body, but has inferior mechanical properties and lacks aqueous stability. In this study, electrospun scaffolds from neat zein and zein blended with prepolymer and mildly cross-linked poly(glycerol sebacate (PGS were fabricated. Less toxic solvents like acetic acid and ethanol were used. The morphological, physiochemical and degradation properties of the as-spun fiber mats were determined. Neat zein and zein-PGS fiber mats with high zein concentration (24 wt % and 27 wt % showed defect-free microstructures. The average fiber diameter decreased with increasing PGS amount from 0.7 ± 0.2 µm to 0.09 ± 0.03 µm. The addition of PGS to zein resulted in a seven-fold increase in ultimate tensile strength and a four-fold increase in failure strain, whereas the Young’s Modulus did not change significantly. Degradation tests in phosphate buffered saline revealed the morphological instability of zein containing fiber mats in contact with aqueous media. Therefore, the fibers were in situ cross-linked with N-(3-Dimethylaminopropyl-N′-ethylcarbodiimide (EDC/N-Hydroxysuccinimide (NHS, which led to improved morphological stability in aqueous environment. The novel fibers have suitable properties for application in soft tissue engineering.

  17. The relationship between red meat allergy and sensitization to gelatin and galactose-alpha-1,3-galactose

    Science.gov (United States)

    Mullins, Raymond James; James, Hayley; Platts-Mills, Thomas A.E.; Commins, Scott

    2012-01-01

    Background We have observed patients clinically allergic to red meat and meat-derived gelatin. Objective We describe a prospective evaluation of the clinical significance of gelatin sensitization, the predictive value of a positive test and an examination of the relationship between allergic reactions to red meat and sensitization to gelatin and alpha-Gal. Methods Adult patients evaluated 1997-2011 for suspected allergy/anaphylaxis to medication, insect venom or food were skin tested with gelatin colloid. In vitro (ImmunoCap) testing was undertaken where possible. Results Positive gelatin tests were observed in 40/1335 individuals; 30/40 patients with red meat allergy (12 also clinically allergic to gelatin); 2/2 with gelatin colloid anaphylaxis; 4/172 with idiopathic anaphylaxis (all responded to intravenous gelatin challenge of 0.02 to 0.4g); 4/368 with drug allergy. Testing was negative in all patients with venom allergy (n=241), non-meat food allergy (n=222), and miscellaneous disorders (n=290). ImmunoCap was positive to alpha-Gal in 20/24 meat allergics and in 20/22 with positive gelatin skin tests. The results of gelatin skin testing and anti-alpha-Gal IgE were strongly correlated (r=0.46; Pmeat were sensitized to gelatin and a subset was clinically allergic to both. The detection of alpha-Gal in gelatin and correlation between the results of alpha-Gal and gelatin testing raises the possibility that alpha-Gal IgE may be the target of reactivity to gelatin. The pathogenic relationship between tick bites and sensitization to red meat, alpha-Gal and gelatin (with or without clinical reactivity) remains uncertain. PMID:22480538

  18. Relationship between red meat allergy and sensitization to gelatin and galactose-α-1,3-galactose.

    Science.gov (United States)

    Mullins, Raymond James; James, Hayley; Platts-Mills, Thomas A E; Commins, Scott

    2012-05-01

    We have observed patients clinically allergic to red meat and meat-derived gelatin. We describe a prospective evaluation of the clinical significance of gelatin sensitization, the predictive value of a positive test result, and an examination of the relationship between allergic reactions to red meat and sensitization to gelatin and galactose-α-1,3-galactose (α-Gal). Adult patients evaluated in the 1997-2011 period for suspected allergy/anaphylaxis to medication, insect venom, or food were skin tested with gelatin colloid. In vitro (ImmunoCAP) testing was undertaken where possible. Positive gelatin test results were observed in 40 of 1335 subjects: 30 of 40 patients with red meat allergy (12 also clinically allergic to gelatin), 2 of 2 patients with gelatin colloid-induced anaphylaxis, 4 of 172 patients with idiopathic anaphylaxis (all responded to intravenous gelatin challenge of 0.02-0.4 g), and 4 of 368 patients with drug allergy. Test results were negative in all patients with venom allergy (n = 241), nonmeat food allergy (n = 222), and miscellaneous disorders (n = 290). ImmunoCAP results were positive to α-Gal in 20 of 24 patients with meat allergy and in 20 of 22 patients with positive gelatin skin test results. The results of gelatin skin testing and anti-α-Gal IgE measurements were strongly correlated (r = 0.46, P meat were sensitized to gelatin, and a subset was clinically allergic to both. The detection of α-Gal in gelatin and correlation between the results of α-Gal and gelatin testing raise the possibility that α-Gal IgE might be the target of reactivity to gelatin. The pathogenic relationship between tick bites and sensitization to red meat, α-Gal, and gelatin (with or without clinical reactivity) remains uncertain. Copyright © 2012 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  19. Preparation of Low Molecular Weight Gelatin Using Microwave Discharge Electrodeless Lamp/TiO2 Photocatalyst Hybrid System.

    Science.gov (United States)

    Lee, Do-Jin; Kim, Hangun; Park, Young-Kwon; Kim, Byung Hoon; Lee, Heon; Jungf, Sana-Chul

    2016-02-01

    In this study, an MDEL/TiO2 photocatalyst hybrid system was applied to the production of low molecular weight gelatin. The molecular weight of produed gelatin decreased with increasing microwave intensity and increasing treatment time. The abscission of the chemical bonds between the con- stituents of gelatin by photocatalytic reaction did not alter the characteristics of gelatin. Formation of any by-products due to side reaction was not observed. It is suggested that gelatin was depolymerized by hydroxyl radicals produced during the MDEL/TiO2 photochemical reaction.

  20. Tagging target genes of the mat1-2-1 transcription factor in Fusarium verticillioides (Gibberella fujikuroi MP-A)

    NARCIS (Netherlands)

    Keszthelyi, A.; Jeney, A.; Kerenyi, Z.; Mendes, O.; Waalwijk, C.; Hornok, L.

    2007-01-01

    Mating type in filamentous ascomycetes is controlled by idiomorphic alleles, named MAT1-1 and MAT1-2, which contain 1-3 genes. Of these genes MAT1-1-1 and MAT1-2-1 encode putative transcription factors and are thus considered to be the major regulators of sexual communication and mating. Fungi with

  1. Characterization of film-forming solutions and films incorporating free and nanoencapsulated tea polyphenol prepared by gelatins with different Bloom values

    Science.gov (United States)

    Gelatin film-forming solutions and their films incorporating tea polyphenol (TP) and chitosan nanoparticles (CSNs) were prepared from gelatins with different Bloom values (100, 150 and 225). Blank gelatin film-forming solutions and films were prepared as controls. Gelatins with higher Bloom values h...

  2. Extraction and characterization of gelatin from two edible Sudanese insects and its applications in ice cream making.

    Science.gov (United States)

    Mariod, Abdalbasit Adam; Fadul, Hadia

    2015-07-01

    Three methods were used for extraction of gelatin from two insects, melon bug (Coridius viduatus) and sorghum bug (Agonoscelis versicoloratus versicoloratus). Extraction of insect gelatin using hot water gave higher yield reached up to 3.0%, followed by mild acid extraction which gave 1.5% and distilled water extraction which gave only 1.0%, respectively. The obtained gelatins were characterized by FTIR and the spectra of insect's gelatin seem to be similar when compared with commercial gelatin. Amide II bands of gelatins from melon and sorghum bug appeared around at 1542-1537 cm(-1). Slight differences in the amino acid composition of gelatin extracted from the two insects were observed. Ice cream was made by using 0.5% insect's gelatin and compared with that made using 0.5% commercial gelatin as stabilizing agent. The properties of the obtained ice cream produced using insects gelatin were significantly different when compared with that made using commercial gelatin. © The Author(s) 2014.

  3. Low-fiber diet

    Science.gov (United States)

    ... residue; Low-fiber diet; Fiber restricted diet; Crohn disease - low fiber diet; Ulcerative colitis - low fiber diet; ... them if they do not contain seeds or pulp: Yellow squash (without seeds) Spinach Pumpkin Eggplant Potatoes, ...

  4. Effect of sodium lauryl sulfate in dissolution media on dissolution of hard gelatin capsule shells.

    Science.gov (United States)

    Zhao, Fang; Malayev, Vyacheslav; Rao, Venkatramana; Hussain, Munir

    2004-01-01

    Sodium lauryl sulfate (SLS) is a commonly used surfactant in dissolution media for poorly water soluble drugs. However, it has occasionally been observed that SLS negatively impacts the dissolution of drug products formulated in gelatin capsules. This study investigated the effect of SLS on the dissolution of hard gelatin capsule shells. The USP paddle method was used with online UV monitoring at 214 nm (peptide bond). Empty size #0 capsule shells were held to the bottom of the dissolution vessel by magnetic three-prong sinkers. SLS significantly slowed down the dissolution of gelatin shells at pH < 5. Visually, the gelatin shells transformed into some less-soluble precipitate under these conditions. This precipitate was found to contain a higher sulfur content than the gelatin control sample by elemental analysis, indicating that SLS is part of the precipitate. Additionally, the slowdown of capsule shell dissolution was shown to be dependent on the SLS concentration and the ionic strength of the media. SLS interacts with gelatin to form a less-soluble precipitate at pH < 5. The use of SLS in dissolution media at acidic pH should be carefully evaluated for gelatin capsule products.

  5. Evaluation of hemocompatibility and endothelialization of hybrid poly(vinyl alcohol) (PVA)/gelatin polymer films.

    Science.gov (United States)

    Ino, Julia M; Sju, Ervi; Ollivier, Véronique; Yim, Evelyn K F; Letourneur, Didier; Le Visage, Catherine

    2013-11-01

    Engineered grafts are still needed for small diameter blood vessels reconstruction. Ideal materials would prevent thrombosis and intimal hyperplasia by displaying hemocompatibility and mechanical properties close to those of native vessels. In this study, poly(vinyl alcohol) (PVA)/gelatin blends were investigated as a potential vascular support scaffold. We modified a chemically crosslinked PVA hydrogel by incorporation of gelatin to improve endothelial cell attachment with a single-step method. A series of crosslinked PVA/gelatin films with specific ratios set at 100:0, 99:1, 95:5, and 90:10 (w/w) were prepared and their mechanical properties were examined by uniaxial tensile testing. Tubes, obtained from sutured films, were found highly compliant (3.1-4.6%) and exhibited sufficient mechanical strength to sustain hemodynamic strains. PVA-based hydrogels maintained low level of platelet adhesion and low thrombogenic potential. Endothelial cell adhesion and proliferation were drastically improved on PVA/gelatin films with a feed gelatin content as low as 1% (w/w), leading to the formation of a confluent endothelium. Hydrogels with higher gelatin content did not sustain complete endothelialization because of modifications of the film surface, including phase segregation and formation of microdomains. Thus, PVA/gelatin (99:1, w/w) hydrogels appear as promising materials for the design of endothelialized vascular materials with long-term patency. Copyright © 2013 Wiley Periodicals, Inc.

  6. 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.

  7. Physicochemical Properties of Gelatin Extracted from Buffalo Hide Pretreated with Different Acids.

    Science.gov (United States)

    Mulyani, Sri; Setyabudi, Francis M C Sigit; Pranoto, Yudi; Santoso, Umar

    2017-01-01

    The acid pretreatment of collagen molecules disrupts their crosslinks and assists in the release of acid-soluble proteins, fats, and other components. Generally, to achieve optimum extraction efficiency, strong acids may be used at a lower acid concentration compared to weak acids. This study aimed to determine the yield and physicochemical properties of gelatins extracted from buffalo hides pretreated with different acids. Hides were extracted with hydrochloric, citric, and acetic acids at concentrations of 0.3, 0.6, 0.9, 1.2, and 1.5 M. A completely randomized design and the least significant difference test were used in the experimental design, and all measurements were performed in triplicate. The highest yield (29.17%) was obtained from pretreatment with 0.9 M HCl. The gel strength did not differ significantly ( p >0.05) according to acid type (280.26-259.62 g Bloom), and the highest viscosity was obtained from the 0.6 M citric acid pretreatment. All the gelatins contained α- and β-chain components and several degraded peptides (24-66 kDa). The color and Fourier-transform infrared spectrum of the gelatin extracted using 0.9 M HCl were similar to those of commercial bovine skin gelatin. In general, the physicochemical properties of the gelatin complied with the industry standard set by the Gelatin Manufacturers Institute of America, revealing that buffalo hide could serve as a potential alternative source of gelatin.

  8. Inhibition of ice crystal growth in ice cream mix by gelatin hydrolysate.

    Science.gov (United States)

    Damodaran, Srinivasan

    2007-12-26

    The inhibition of ice crystal growth in ice cream mix by gelatin hydrolysate produced by papain action was studied. The ice crystal growth was monitored by thermal cycling between -14 and -12 degrees C at a rate of one cycle per 3 min. It is shown that the hydrolysate fraction containing peptides in the molecular weight range of about 2000-5000 Da exhibited the highest inhibitory activity on ice crystal growth in ice cream mix, whereas fractions containing peptides greater than 7000 Da did not inhibit ice crystal growth. The size distribution of gelatin peptides formed in the hydrolysate was influenced by the pH of hydrolysis. The optimum hydrolysis conditions for producing peptides with maximum ice crystal growth inhibitory activity was pH 7 at 37 degrees C for 10 min at a papain to gelatin ratio of 1:100. However, this may depend on the type and source of gelatin. The possible mechanism of ice crystal growth inhibition by peptides from gelatin is discussed. Molecular modeling of model gelatin peptides revealed that they form an oxygen triad plane at the C-terminus with oxygen-oxygen distances similar to those found in ice nuclei. Binding of this oxygen triad plane to the prism face of ice nuclei via hydrogen bonding appears to be the mechanism by which gelatin hydrolysate might be inhibiting ice crystal growth in ice cream mix.

  9. Physicochemical and antifungal properties of bio-nanocomposite film based on gelatin-chitin nanoparticles.

    Science.gov (United States)

    Sahraee, Samar; Milani, Jafar M; Ghanbarzadeh, Babak; Hamishehkar, Hamed

    2017-04-01

    The gelatin-based nanocomposite films containing chitin nanoparticles (N-chitin) with concentrations of 0, 3, 5 and 10% were prepared and their physical, thermal and anti-microbial properties were investigated. Scanning electron microscopy (SEM) micrographs showed that N-chitin size distribution was around 60-70nm which dispersed appropriately at low concentration in gelatin matrix. The results showed that incorporation of N-chitin significantly influenced apparent color and transparency of the gelatin films. The reduced water vapor permeability (WVP) and solubility and higher surface hydrophobicity of the nanocomposite films were obtained by enhancing N-chitin concentration in film formulation. The use of N-chitin up to 5% concentration in the gelatin based nanocomposite film led to improved mechanical properties. Also, the results of differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) confirmed improved stability of nanocomposite films against melting and degradation at high temperatures in comparison to neat gelatin film. The well compatibility of chitin nanoparticles with gelatin polymer was concluded from Fourier transform infrared (FTIR) spectra and X-ray diffraction (XRD) plots. Finally, the gelatin based nanocomposite films had anti-fungal properties against Aspergillus niger in the contact surface zone. Increasing the concentration of N-chitin up to 5% enlarged inhibition zone diameter, but the nanocomposite film containing 10% N-chitin showed smaller inhibition zone. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Photovoltaic fibers

    Science.gov (United States)

    Gaudiana, Russell; Eckert, Robert; Cardone, John; Ryan, James; Montello, Alan

    2006-08-01

    It was realized early in the history of Konarka that the ability to produce fibers that generate power from solar energy could be applied to a wide variety of applications where fabrics are utilized currently. These applications include personal items such as jackets, shirts and hats, to architectural uses such as awnings, tents, large covers for cars, trucks and even doomed stadiums, to indoor furnishings such as window blinds, shades and drapes. They may also be used as small fabric patches or fiber bundles for powering or recharging batteries in small sensors. Power generating fabrics for clothing is of particular interest to the military where they would be used in uniforms and body armor where portable power is vital to field operations. In strong sunlight these power generating fabrics could be used as a primary source of energy, or they can be used in either direct sunlight or low light conditions to recharge batteries. Early in 2002, Konarka performed a series of proof-of-concept experiments to demonstrate the feasibility of building a photovoltaic cell using dye-sensitized titania and electrolyte on a metal wire core. The approach taken was based on the sequential coating processes used in making fiber optics, namely, a fiber core, e.g., a metal wire serving as the primary electrode, is passed through a series of vertically aligned coating cups. Each of the cups contains a coating fluid that has a specific function in the photocell. A second wire, used as the counter electrode, is brought into the process prior to entering the final coating cup. The latter contains a photopolymerizable, transparent cladding which hardens when passed through a UV chamber. Upon exiting the UV chamber, the finished PV fiber is spooled. Two hundred of foot lengths of PV fiber have been made using this process. When the fiber is exposed to visible radiation, it generates electrical power. The best efficiency exhibited by these fibers is 6% with an average value in the 4

  11. VAPOR MIXER FOR GELATINIZATION OF STARCH IN LIQUEFYING STATION

    Directory of Open Access Journals (Sweden)

    V. V. Ananskikh

    2015-01-01

    Full Text Available Starch hydrolysis is main technological process in production of starch sweeteners. Acid hydrolysis of starch using hydrochloric acid is carried out very fast but it does not allow to carry out full hydrolysis and to produce products with given carbohydrate composition. Bioconversion of starch allows to eliminate these limitations. At production of starch sweeteners from starch using enzymes starch hydrolysis is carried out in two stages At first starch – starch liquefaction the rapid increase of viscosity takes place which requires intensive mixing. Liquefying station consists of jet-cooker, holder, pressure regulator and evaporator. Jet-cooker of starch is its main part, starch is quickly turns into soluble (gelatinized state and it is partially liquefied by injection of starch suspension by flow of water vapor under pressure not less than 0,8 MPa. Heat and hydraulic calculation were carried out in order to determine constructive sizes of mixer for cooking of starch. The main hydraulic definable parameters are pressure drop in mixer, vapor pressure at mixer inlet, daily capacity of station by glucose syrup M, product consumption (starch suspension, diameter of inlet section of vapor nozzle. The goal of calculation was to determine vapor consumption M1, diameter d2 of outlet section of confuser injector, length l2 of gelatinization section. For heat calculation there was used Shukhov’s formula along with heat balance equation for gelatinization process. The numerical solution obtained with adopted assumptions given in applied mathematical package MATHCAD, for M = 50 t/day gives required daily vapor consumption M1 = 14,446 т. At hydraulic calculation of pressure drop in mixer there was used Bernoulli’s theorem. Solving obtained equations using MATHCAD found diameter of outlet section of consufer d2 = 0,023 м, vapor pressure inside of mixer p2 = 3,966·105 Па, l2 = 0,128 м. Developed method of calculation is used to determine

  12. Comparative study on nutritional quality and application value in three mutants of indigofera pseudotinctoria mats

    International Nuclear Information System (INIS)

    Mei Shufang; Mei Zhong; Zhao Hua; Huang Xin; Ye Hongxia; Shu Xiaoli; Wu Dianxing

    2013-01-01

    Major nutritional quality and values in purple-leaf, yellow-leaf and high flavone mutants of Indigofera pseudotinctoria Mats were investigated compared with the wild type. The content of protein in leaves of high flavone mutant was 26.45%, 24.31% higher than that of the wild type. The content of fiber in high flavone mutant was 18.92% lower than that of the wild type. The contents of Fe, Cu, Mn, Zn in high flavone mutant were increased by 72.34% , 7.02%, 21.01% and 38.75%, respectively. Contents of TAA and EAA in high flavone mutant were increase by 27.85% and 27.68%, respectively. The contents of protein in purple- and yellow-leaf mutants were lower than that of the wild types, and the contents of Ca in purple- and yellow-leaf mutants were increased by 15.22% and 25.46%. The results above indicated that high flavone mutant had high application values used as feed crop, while purple- and yellow-leaf mutants also had feeding values to some extent. (authors)

  13. Photosynthetic and Behavioral Versatility of the Cyanobacterium Oscillatoria-Boryana in a Sulfide-Rich Microbial Mat

    DEFF Research Database (Denmark)

    CASTENHOLZ, RW; JØRGENSEN, BB; DAMELIO, E.

    1991-01-01

    resulted in a downward retreat. The result was a lowered irradiance level for the Oscillatoria but, nevertheless, a high rate of oxygenic photosynthesis. O. boryana is a versatile cyanobacterium that appears to avoid photoinhibitory conditions and to optimize its light intensity for photosynthesis...... with dense O. boryana populations were used to make vertical profiles at intervals of 0.1-0.2 mm and also to estimate rates of oxygenic and anoxygenic photosynthesis during rapid light-dark transitions. In addition, attenuation of irradiance was measured in mats with O. boryana by a spectroradiometer...... with mini-fiber optic probe. Light-dependent incorporation of [C-14]-bicarbonate and [C-14]-acetate was measured in collected field populations of O. boryana. The combined results led to the conclusion that populations of O. boryana typically employed sulfide-dependent anoxygenic photosynthesis in early...

  14. Shooting with sound: optimizing an affordable ballistic gelatin recipe in a graded ultrasound phantom education program.

    Science.gov (United States)

    Tanious, Shariff F; Cline, Jamie; Cavin, Jennifer; Davidson, Nathan; Coleman, J Keegan; Goodmurphy, Craig W

    2015-06-01

    The goal of this study was to investigate the durability and longevity of gelatin formulas for the production of staged ultrasound phantoms for education. Gelatin phantoms were prepared from Knox gelatin (Kraft Foods, Northfield, IL) and a standard 10%-by-mass ordinance gelatin solution. Phantoms were durability tested by compressing to a 2-cm depth until cracking was visible. Additionally, 16 containers with varying combinations of phenol, container type, and storage location were tested for longevity against desiccation and molding. Once formulation was determined, 4 stages of phantoms from novice to clinically relevant were poured, and clinicians with ultrasound training ranked them on a 7-point Likert scale based on task difficulty, phantom suitability, and fidelity. On durability testing, the ballistic gelatin outperformed the Knox gelatin by more than 200 compressions. On longevity testing, gelatin with a 0.5% phenol concentration stored with a lid and refrigeration lasted longest, whereas containers without a lid had desiccation within 1 month, and those without phenol became moldy within 6 weeks. Ballistic gelatin was more expensive when buying in small quantities but was 7.4% less expensive when buying in bulk. The staged phantoms were deemed suitable for training, but clinicians did not consistently rank the phantoms in the intended order of 1 to 4 (44%). Refrigerated and sealed ballistic gelatin with phenol was a cost-effective method for creating in-house staged ultrasound phantoms suitable for large-scale ultrasound educational training needs. Clinician ranking of phantoms may be influenced by current training methods that favor biological tissue scanning as easier. © 2015 by the American Institute of Ultrasound in Medicine.

  15. Development of a gelatin-based polyurethane vascular graft by spray, phase-inversion technology

    International Nuclear Information System (INIS)

    Losi, Paola; Al Kayal, Tamer; Briganti, Enrica; Volpi, Silvia; Soldani, Giorgio; Mancuso, Luisa; Cao, Giacomo; Celi, Simona; Gualerzi, Alice

    2015-01-01

    The capacity of a composite vascular graft constituting polyurethane (PU) and gelatin to support cell growth was investigated using human mesenchymal stem cells (hMSCs). Gelatin-based polyurethane grafts were fabricated by co-spraying polyurethane and gelatin using a spray, phase-inversion technique. Graft microstructure was investigated by light and scanning electron microscopy. Uniaxial tensile tests were performed to assess the grafts’ mechanical properties in longitudinal and circumferential directions. hMSCs obtained from bone marrow aspirate were seeded onto flat graft samples. After 24, 48, and 72 h of incubation, cell morphology was evaluated by Giemsa staining and cell viability was calculated by XTT assay. SEM analysis evidenced that PU samples display a microporous structure, whereas the gelatin-based PU samples show a fibrillar appearance. The presence of cross-linked gelatin produced a significant increase of ultimate tensile strength and ultimate elongation in circumferential directions compared to PU material. Qualitative analysis of hMSC adhesion onto the grafts revealed remarkable differences between gelatin-based PU and control graft. hMSCs grown onto gelatin-based PU graft form a monolayer that reached confluence at 72 h, whereas cells seeded onto the control graft were not able to undergo appropriate spreading. hMSCs grown onto gelatin-based PU graft showed significantly higher viability than cells seeded onto bare PU at all time points. In conclusion, a composite vascular graft was successfully manufactured by simultaneous co-spraying of a synthetic polymer and a protein to obtain a scaffold that combines the mechanical characteristics of polyurethanes with the favorable cell interaction features of gelatin. (paper)

  16. Experimental Investigation and Analysis of Mercerized and Citric Acid Surface Treated Bamboo Fiber Reinforced Composite

    Science.gov (United States)

    De, Jyotiraman; Baxi, R. N., Dr.

    2017-08-01

    Mercerization or NaOH fiber surface treatment is one of the most popular surface treatment processes to make the natural fibers such as bamboo fibers compatible for use as reinforcing material in composites. But NaOH being a chemical is hazardous and polluting to the nature. This paper explores the possibility of use of naturally derived citric acid for bamboo fiber surface treatment and its comparison with NaOH treated Bamboo Fiber Composites. Untreated, 2.5 wt% NaOH treated and 5 wt% citric acid treated Bamboo Fiber Composites with 5 wt% fiber content were developed by Hand Lay process. Bamboo mats made of bamboo slivers were used as reinforcing material. Mechanical and physical characterization was done to compare the effects of NaOH and citric acid bamboo fiber surface treatment on mechanical and physical properties of Bamboo Fiber Composite. The experiment data reveals that the tensile and flexural strength was found to be highest for citric acid and NaOH treated Bamboo Fiber Composite respectively. Water absorption tendency was found more than the NaOH treated Bamboo Fiber Composites. SEM micrographs used to analyze the morphology of fracture surface of tensile test specimens confirm improvement in fiber-matrix interface bonding due to surface treatment of bamboo fibers.

  17. Curcumin-Loaded Chitosan/Gelatin Composite Sponge for Wound Healing Application

    Directory of Open Access Journals (Sweden)

    Van Cuong Nguyen

    2013-01-01

    Full Text Available Three composite sponges were made with 10% of curcumin and by using polymers, namely, chitosan and gelatin with various ratios. The chemical structure and morphology were evaluated by FTIR and SEM. These sponges were evaluated for water absorption capacity, antibacterial activity, in vitro drug release, and in vivo wound healing studies by excision wound model using rabbits. The in vivo study presented a greater wound closure in wounds treated with curcumin-composite sponge than those with composite sponge without curcumin and untreated group. These obtained results showed that combination of curcumin, chitosan and gelatin could improve the wound healing activity in comparison to chitosan, and gelatin without curcumin.

  18. Preparation of biodegradable gelatin/PVA porous scaffolds for skin regeneration.

    Science.gov (United States)

    Mahnama, Hossein; Dadbin, Susan; Frounchi, Masoud; Rajabi, Sareh

    2017-08-01

    Porous scaffolds composed of gelatin/poly (vinyl alcohol), (Gel/PVA), were prepared using combination of freeze gelation and freeze drying methods. The effect of polymer concentration, gelatin/PVA ratio, and glutaraldehyde/gelatin ratio (GA/Gel) was investigated on morphology of pores, swelling ratio, biodegradation, and skin cell culture. At optimum preparation conditions the scaffolds had uniform pore size distributions showing high swelling ratio of 23.6. The scaffolds were of biodegradable nature and almost degraded in 28 days. Human dermal fibroblast cells (HDF) were cultured on the scaffolds and MTS assay was conducted to evaluate the influence of PVA on growth and proliferation of the cells.

  19. Association of saponins in water and water-gelatine mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Sarnthein-Graf, Carlo; La Mesa, Camillo

    2004-08-15

    The solution properties of a commercial saponin obtained from Quillaja Bark (QBS), have been investigated in a wide range of experimental conditions in water and in the presence of moderate amounts of porcine skin gelatine, GEL. Saponins are surface active and form micelles at very low concentration. Significant changes in the solution dielectric properties are concomitant to micelle formation. The combination of thermodynamic, spectroscopic, transport and dielectric methods characterises the micelle formation, giving information on interactions between the components. NMR relaxation times, NMR self-diffusion and dielectric measurements were used. Micelle aggregation numbers, inferred from light scattering, indicate the formation of relatively large aggregates. No evidence for interactions between protein and surfactant was obtained. This is presumably due to the limited ionisation of acidic groups on the surfactant, which does not allow significant electrostatic binding with the protein.

  20. Association of saponins in water and water-gelatine mixtures

    International Nuclear Information System (INIS)

    Sarnthein-Graf, Carlo; La Mesa, Camillo

    2004-01-01

    The solution properties of a commercial saponin obtained from Quillaja Bark (QBS), have been investigated in a wide range of experimental conditions in water and in the presence of moderate amounts of porcine skin gelatine, GEL. Saponins are surface active and form micelles at very low concentration. Significant changes in the solution dielectric properties are concomitant to micelle formation. The combination of thermodynamic, spectroscopic, transport and dielectric methods characterises the micelle formation, giving information on interactions between the components. NMR relaxation times, NMR self-diffusion and dielectric measurements were used. Micelle aggregation numbers, inferred from light scattering, indicate the formation of relatively large aggregates. No evidence for interactions between protein and surfactant was obtained. This is presumably due to the limited ionisation of acidic groups on the surfactant, which does not allow significant electrostatic binding with the protein

  1. 3D printing process of oxidized nanocellulose and gelatin scaffold.

    Science.gov (United States)

    Xu, Xiaodong; Zhou, Jiping; Jiang, Yani; Zhang, Qi; Shi, Hongcan; Liu, Dongfang

    2018-08-01

    For tissue engineering applications tissue scaffolds need to have a porous structure to meet the needs of cell proliferation/differentiation, vascularisation and sufficient mechanical strength for the specific tissue. Here we report the results of a study of the 3D printing process for composite materials based on oxidized nanocellulose and gelatin, that was optimised through measuring rheological properties of different batches of materials after different crosslinking times, simulation of the pneumatic extrusion process and 3D scaffolds fabrication with Solidworks Flow Simulation, observation of its porous structure by SEM, measurement of pressure-pull performance, and experiments aimed at finding out the vitro cytotoxicity and cell morphology. The materials printed are highly porous scaffolds with good mechanical properties.

  2. Selective flotation of PVC using gelatin and lignin alkali.

    Science.gov (United States)

    Yenial, Unzile; Kangal, Olgaç; Güney, Ali

    2013-06-01

    Recycling has become one of the most important issues as a result of increasing waste mass in present day. This is especially important for polymer wastes as they are hard to degenerate in nature. Today, most of the practical methods used for the recycling of waste mass, such as hand sorting, gravity separation, etc., cannot be performed successfully owing to close densities of polymers. Froth flotation can be used successfully and economically for this purpose. The main objective of this study was to investigate the effect of plasticizer reagents and the success of froth flotation at plastic recycling. In this study, lignin alkali and gelatin were used as plasticizer reagents. The effect of these reagents was searched with the parameters of pH, concentration, conditioning and flotation time. In the case of post-consumed polyethylene terephthalate and polyvinyl chloride (PVC), 98.9% purity of PVC was obtained at optimum conditions.

  3. Electrical Characterization and Modeling of a Gelatin/Graphene System

    Directory of Open Access Journals (Sweden)

    Giovanni Landi

    2015-01-01

    Full Text Available A gelatin/graphene composite has been analyzed by means of current density-voltage and the electrical impedance measurements. The DC electrical behavior has been interpreted in terms of an equivalent Thévenin model taking into account the open circuit voltage and the series resistance. A model based on the effect of the electrical double layer and on the diffusion of the charge carriers is used for the analysis of the experimental data, obtained in the frequency domain. The model reveals for any applied voltages a marked diffusion process at low frequencies. In particular, where the charge transfer mechanism is dominant, the time distribution of the reaction rates reveals that several multiple step reactions occur in the materials, especially at high values of the applied forward bias voltages.

  4. Rigid Polyurethane Foam Thermal Insulation Protected with Mineral Intumescent Mat

    Directory of Open Access Journals (Sweden)

    Kirpluks Mikelis

    2014-12-01

    Full Text Available One of the biggest disadvantages of rigid polyurethane (PU foams is its low thermal resistance, high flammability and high smoke production. Greatest advantage of this thermal insulation material is its low thermal conductivity (λ, which at 18-28 mW/(m•K is superior to other materials. To lower the flammability of PU foams, different flame retardants (FR are used. Usually, industrially viable are halogenated liquid FRs but recent trends in EU regulations show that they are not desirable any more. Main concern is toxicity of smoke and health hazard form volatiles in PU foam materials. Development of intumescent passive fire protection for foam materials would answer problems with flammability without using halogenated FRs. It is possible to add expandable graphite (EG into PU foam structure but this increases the thermal conductivity greatly. Thus, the main advantage of PU foam is lost. To decrease the flammability of PU foams, three different contents 3%; 9% and 15% of EG were added to PU foam formulation. Sample with 15% of EG increased λ of PU foam from 24.0 to 30.0 mW/(m•K. This paper describes the study where PU foam developed from renewable resources is protected with thermally expandable intumescent mat from Technical Fibre Products Ltd. (TFP as an alternative to EG added into PU material. TFP produces range of mineral fibre mats with EG that produce passive fire barrier. Two type mats were used to develop sandwich-type PU foams. Also, synergy effect of non-halogenated FR, dimethyl propyl phosphate and EG was studied. Flammability of developed materials was assessed using Cone Calorimeter equipment. Density, thermal conductivity, compression strength and modulus of elasticity were tested for developed PU foams. PU foam morphology was assessed from scanning electron microscopy images.

  5. Gelatin methacrylamide as coating material in cell culture.

    Science.gov (United States)

    Egger, Michael; Tovar, Günter E M; Hoch, Eva; Southan, Alexander

    2016-06-13

    Unmodified gelatin (uG) is widely used as a coating material in cell culture for improving surface properties. In this study, the authors investigated if gelatin methacrylamide (GM) with a medium degree of methacrylamide modification (GM1.5) and a high degree of methacrylamide modification (GM4) are equally suitable for this purpose. Therefore, gold surfaces were coated with uG, GM1.5, and GM4 by adsorption of the polymers on the surfaces. Coating success was confirmed by spectroscopic ellipsometry, contact angle measurements, surface plasmon resonance spectroscopy (SPRS), and atomic force microscopy (AFM). The authors found that upon adsorption of uG, GM1.5, a nd GM4 on gold, thin films with thicknesses of 2.95 nm, 2.50 nm, and 2.26 nm were formed. The coated surfaces showed advancing contact angles of 46° (uG and GM1.5) and 52° (GM4) without alteration of the surface roughness determined by AFM. Protein adsorption taking place on the coated surfaces was measured during contact of the surfaces with fetal calf serum by SPRS. Protein adsorption on the coated surfaces was reduced by the factor of 6.4 (uG), 5.4 (GM1.5), and 4.6 (GM4) compared to gold surfaces. Human fibroblasts cultured on the surfaces showed excellent viability shown by water soluble tetrazolium salt assay as well as live/dead staining with propidium iodide and fluorescein diacetate. No cytotoxic effects of the GM coated surfaces were observed, giving rise to the conclusion that GMs are suitable materials as coatings in cell culture.

  6. Cellularized Bilayer Pullulan-Gelatin Hydrogel for Skin Regeneration.

    Science.gov (United States)

    Nicholas, Mathew N; Jeschke, Marc G; Amini-Nik, Saeid

    2016-05-01

    Skin substitutes significantly reduce the morbidity and mortality of patients with burn injuries and chronic wounds. However, current skin substitutes have disadvantages related to high costs and inadequate skin regeneration due to highly inflammatory wounds. Thus, new skin substitutes are needed. By combining two polymers, pullulan, an inexpensive polysaccharide with antioxidant properties, and gelatin, a derivative of collagen with high water absorbency, we created a novel inexpensive hydrogel-named PG-1 for "pullulan-gelatin first generation hydrogel"-suitable for skin substitutes. After incorporating human fibroblasts and keratinocytes onto PG-1 using centrifugation over 5 days, we created a cellularized bilayer skin substitute. Cellularized PG-1 was compared to acellular PG-1 and no hydrogel (control) in vivo in a mouse excisional skin biopsy model using newly developed dome inserts to house the skin substitutes and prevent mouse skin contraction during wound healing. PG-1 had an average pore size of 61.69 μm with an ideal elastic modulus, swelling behavior, and biodegradability for use as a hydrogel for skin substitutes. Excellent skin cell viability, proliferation, differentiation, and morphology were visualized through live/dead assays, 5-bromo-2'-deoxyuridine proliferation assays, and confocal microscopy. Trichrome and immunohistochemical staining of excisional wounds treated with the cellularized skin substitute revealed thicker newly formed skin with a higher proportion of actively proliferating cells and incorporation of human cells compared to acellular PG-1 or control. Excisional wounds treated with acellular or cellularized hydrogels showed significantly less macrophage infiltration and increased angiogenesis 14 days post skin biopsy compared to control. These results show that PG-1 has ideal mechanical characteristics and allows ideal cellular characteristics. In vivo evidence suggests that cellularized PG-1 promotes skin regeneration and may

  7. Siwonhan-mat: The third taste of Korean foods

    OpenAIRE

    Soon Ah Kang; Hyun Ji Oh; Dai Ja Jang; Min Jung Kim; Dae Young Kwon

    2016-01-01

    Background: Smell and taste are frequently referenced senses when describing flavors of food. In addition to these two senses, Koreans have regarded that there is another sense of taste experienced through the body. This third sense, siwonhan-mat (시원한 맛), describes the sensation of the body including the tongue, stomach, and intestines when eating. While smell and taste play an important role in the enjoyment of food, it is also crucial to evaluate what your body can experience from eating. I...

  8. Determination of triiodothyronine using RIA-Mat T3 kit

    International Nuclear Information System (INIS)

    Hara, Masao

    1975-01-01

    A RIA-Mat T 3 kit was used for an in vitro measurement of triiodothyronine in serum. A resin strip was utilized to absorb free triiodothyronine after the serum was incubated with antibody against triiodothyronine. This test was easy to manipulate and the reproducibility test with same sera, dilution test, and recovery test were also satisfactory. The normal range of triiodothyronine determined with this test kit was 119 +- 40 ng/dl using 50 test sera. Ninety sera with various thyroid diseases were also determined. (auth.)

  9. Effect of Fungal Deterioration on Physical and Mechanical Properties of Hemp and Flax Natural Fiber Composites

    Directory of Open Access Journals (Sweden)

    Bryn Crawford

    2017-10-01

    Full Text Available The development and application of bio-sourced composites have been gaining wide attention, yet their deterioration due to the growth of ubiquitous microorganisms during storage/manufacturing/in-service phases is still not fully understood for optimum material selection and design purposes. In this study, samples of non-woven flax fibers, hemp fibers, and mats made of co-mingled randomly-oriented flax or hemp fiber (50% and polypropylene fiber (50% were subjected to 28 days of exposure to (i no water-no fungi, (ii water only and (iii water along with the Chaetomium globosum fungus. Biocomposite samples were measured for weight loss over time, to observe the rate of fungal growth and the respiration of cellulose components in the fibers. Tensile testing was conducted to measure mechanical properties of the composite samples under different configurations. Scanning electron microscopy was employed to visualize fungal hyphal growth on the natural fibers, as well as to observe the fracture planes and failure modes of the biocomposite samples. Results showed that fungal growth significantly affects the dry mass as well as the tensile elastic modulus of the tested natural fiber mats and composites, and the effect depends on both the type and the length scale of fibers, as well as the exposure condition and time.

  10. Electrospun magnetic nanofibre mats – A new bondable biomaterial using remotely activated magnetic heating

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Yi [Department of Materials Engineering, University of British Columbia, Vancouver (Canada); Key Laboratory of Science & Technology of Eco-Textile, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai (China); Leung, Victor; Yuqin Wan, Lynn [Department of Materials Engineering, University of British Columbia, Vancouver (Canada); Dutz, Silvio [Institut für Biomedizinische Technik und Informatik, Technische Universität Ilmenau (Germany); Department of Nano Biophotonics, Leibniz Institute of Photonic Technology, Jena (Germany); Ko, Frank K., E-mail: frank.ko@ubc.ca [Department of Materials Engineering, University of British Columbia, Vancouver (Canada); Häfeli, Urs O., E-mail: urs.hafeli@ubc.ca [Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver (Canada)

    2015-04-15

    A solvothermal process was adopted to produce hydrophilic magnetite (Fe{sub 3}O{sub 4}) nanoparticles which were subsequently emulsified with a chloroform/methanol (70/30 v/v) solution of poly(caprolactone) (PCL) and then electrospun into a 0.2 mm thick PCL mat. The magnetic heating of the mats at a field amplitude of 25 kA/m and frequency of 400 kHz exhibited promising efficiency for magnetic hyperthermia, with a specific absorption rate of about 40 W/g for the magnetic mat. The produced heat was used to melt the magnetic mat onto the surrounding non-magnetic polymer mat from within, without destroying the nanostructure of the non-magnetic polymer more than 0.5 mm away. Magnetic nanofibre mats might thus be useful for internal heat sealing applications, and potentially also for thermotherapy.

  11. Nanofiber mats composed of a chitosan-poly(d,l-lactic-co-glycolic acid)-poly(ethylene oxide) blend as a postoperative anti-adhesion agent.

    Science.gov (United States)

    Ko, Jae Eok; Ko, Young-Gwang; Kim, Won Il; Kwon, Oh Kyoung; Kwon, Oh Hyeong

    2017-10-01

    Postoperative tissue adhesion causes serious complications and suffering in 90% of patients after peritoneum surgery, while commercial anti-adhesion agents cannot completely prevent postoperative peritoneal adhesions. This study demonstrates electrospining of a blended solution of chitosan, poly(d,l-lactic-co-glycolic acid) (PLGA), and poly(ethylene oxide) (PEO) to fabricate a chitosan-based nanofibrous mat as a postoperative anti-adhesion agent. Rheological studies combined with scanning electron microscopy reveal that the spinnability of the chitosan-PLGA solution could be controlled by adjusting the blend ratio and concentration with average fiber diameter from 634 to 913 nm. Biodegradation of the nanofiber specimens showed accelerated hydrolysis by chitosan. Proliferation of fibroblasts and antimicrobial activity of nanofibers containing chitosan was analyzed. Abdominal defects with cecum adhesion in rats demonstrated that the blend nanofiber mats were effective in preventing tissue adhesion as a barrier (4 weeks after abdominal surgery) by coverage of exfoliated peritoneum and insufficient wound sites at the beginning of the wound healing process. Chitosan-PLGA-PEO blend nanofiber mats will provide a promising key as a postoperative anti-adhesion agent. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1906-1915, 2017. © 2016 Wiley Periodicals, Inc.

  12. Facile synthesis of Ca{sub 0.68}Si{sub 9}Al{sub 3}(ON){sub 16}:Eu{sup 2+} microbelts mat with the enhanced fluorescence and mechanical performance

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Hailei; Cui, Bo [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620 (China); Wang, Hongzhi, E-mail: wanghz@dhu.edu.cn [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620 (China); Zhang, Qinghong [Engineering Research Center of Advanced Glasses Manufacturing Technology, MOE, College of Materials Science and Engineering, Donghua University, Shanghai 201620 (China); Li, Yaogang, E-mail: yaogang_li@dhu.edu.cn [Engineering Research Center of Advanced Glasses Manufacturing Technology, MOE, College of Materials Science and Engineering, Donghua University, Shanghai 201620 (China)

    2016-01-15

    Yellow-emitting phosphor mat consisting of Ca{sub 0.68}Si{sub 9}Al{sub 3}(ON){sub 16}:Eu{sup 2+} microbelts was prepared by electrospinning and subsequent nitridation. The as-prepared fiber precursor is smooth and uniform with diameter of 800 to 900 nm. After removing organic templates and nitridation, the morphology of the fiber is well retained and thus a smooth microbelts phosphor mat was obtained. X-ray diffraction and the photoluminescence (PL) spectra reveals that a relatively pure Ca{sub 0.68}Si{sub 9}Al{sub 3}(ON){sub 16} phase and the highest spectral intensity could be obtained at a relatively low temperature of 1500 °C and Eu{sup 2+} doping molar concentration of 0.1. The excitation spectra exhibits a broad band, ranging from 300 to 550 nm, which could be excited by blue LED chip at room temperature. The emission spectra of all exhibits a single broad band in the 400 to 700 nm region, with the maximum intensity always being at 580 nm. The Ca{sub 0.68}Si{sub 9}Al{sub 3}(ON){sub 16}:Eu{sup 2+} microbelts phosphor mat has the bending strength about 4.5 MPa with a photoluminescence quantum yield as high as 65%. By employing it as yellow phosphor, a high-performance warm white LED could be fabricated with low correlated color temperature (2985 K), high-color-rendering index (Ra=86) and luminous efficacy of 129.5 lm W{sup −1}. Different color temperatures also could be tuned by employing microbelts phosphor mats with different thicknesses. - Graphical abstract: Yellow-emitting phosphor mat consisting of Ca{sub 0.68}Si{sub 9}Al{sub 3}(ON){sub 16}:Eu{sup 2+} microbelts fibers were prepared by electrospinning the fiber precursor and subsequent nitridation. Because the good mechanical strength it could be utilized to realize LEDs remote packaging. By employing it as yellow phosphor, a high-performance warm white LED could be fabricated. Different color temperatures also could be tuned by employing microbelts phosphor mats with different thicknesses

  13. The contribution of microbial mats to the arsenic geochemistry of an ancient gold mine

    International Nuclear Information System (INIS)

    Drewniak, Lukasz; Maryan, Natalia; Lewandowski, Wiktor; Kaczanowski, Szymon; Sklodowska, Aleksandra

    2012-01-01

    The ancient Zloty Stok (SW Poland) gold mine is such an environment, where different microbial communities, able to utilize inorganic arsenic species As(III) and As(V), are found. The purpose of the present study was to (i) estimate prokaryotic diversity in the microbial mats in bottom sediments of this gold mine, (ii) identify microorganisms that can metabolize arsenic, and (iii) estimate their potential role in the arsenic geochemistry of the mine and in the environment. The oxidation/reduction experiments showed that the microbial mat community may significantly contribute to arsenic contamination in groundwater. The presence of both arsenite oxidizing and dissimilatory arsenate reducing bacteria in the mat was confirmed by the detection of arsenite oxidase and dissimilatory arsenate reductase genes, respectively. This work also demonstrated that microorganisms utilizing other compounds that naturally co-occur with arsenic are present within the microbial mat community and may contribute to the arsenic geochemistry in the environment. - Highlights: ► The microbial mats from this ancient gold mine are highly diverse community. ► As(III) oxidizing and As(V) reducing bacteria are present in the mats. ► As redox transformations are linked to the metabolism of microbial mats bacteria. ► Microbial mats play a crucial role in the As biogeochemical cycle within the mine. - The microbial mats from this ancient gold mine can mediate oxidation/reduction reaction of arsenic and in this way may significantly contribute to arsenic contamination in groundwater.

  14. Perfect simulation and moment properties for the Matérn type III process

    DEFF Research Database (Denmark)

    Møller, Jesper; Huber, Mark L.; Wolpert, Robert L.

    2010-01-01

    In a seminal work, Bertil Matérn introduced several types of processes for modeling repulsive point processes. In this paper an algorithm is presented for the perfect simulation of the Matérn III process within a bounded window in , fully accounting for edge effects. A simple upper bound on the m......In a seminal work, Bertil Matérn introduced several types of processes for modeling repulsive point processes. In this paper an algorithm is presented for the perfect simulation of the Matérn III process within a bounded window in , fully accounting for edge effects. A simple upper bound...

  15. Reconstruction of hyperspectral image using matting model for classification

    Science.gov (United States)

    Xie, Weiying; Li, Yunsong; Ge, Chiru

    2016-05-01

    Although hyperspectral images (HSIs) captured by satellites provide much information in spectral regions, some bands are redundant or have large amounts of noise, which are not suitable for image analysis. To address this problem, we introduce a method for reconstructing the HSI with noise reduction and contrast enhancement using a matting model for the first time. The matting model refers to each spectral band of an HSI that can be decomposed into three components, i.e., alpha channel, spectral foreground, and spectral background. First, one spectral band of an HSI with more refined information than most other bands is selected, and is referred to as an alpha channel of the HSI to estimate the hyperspectral foreground and hyperspectral background. Finally, a combination operation is applied to reconstruct the HSI. In addition, the support vector machine (SVM) classifier and three sparsity-based classifiers, i.e., orthogonal matching pursuit (OMP), simultaneous OMP, and OMP based on first-order neighborhood system weighted classifiers, are utilized on the reconstructed HSI and the original HSI to verify the effectiveness of the proposed method. Specifically, using the reconstructed HSI, the average accuracy of the SVM classifier can be improved by as much as 19%.

  16. Mechanisms of Mindfulness Training: Monitor and Acceptance Theory (MAT)1

    Science.gov (United States)

    Lindsay, Emily K.; Creswell, J. David

    2016-01-01

    Despite evidence linking trait mindfulness and mindfulness training with a broad range of effects, still little is known about its underlying active mechanisms. Mindfulness is commonly defined as (1) the ongoing monitoring of present-moment experience (2) with an orientation of acceptance. Building on conceptual, clinical, and empirical work, we describe a testable theoretical account to help explain mindfulness effects on cognition, affect, stress, and health outcomes. Specifically, Monitor and Acceptance Theory (MAT) posits that (1), by enhancing awareness of one’s experiences, the skill of attention monitoring explains how mindfulness improves cognitive functioning outcomes, yet this same skill can increase affective reactivity. Second (2), by modifying one’s relation to monitored experience, acceptance is necessary for reducing affective reactivity, such that attention monitoring and acceptance skills together explain how mindfulness improves negative affectivity, stress, and stress-related health outcomes. We discuss how MAT contributes to mindfulness science, suggest plausible alternatives to the account, and offer specific predictions for future research. PMID:27835764

  17. Coastal microbial mat diversity along a natural salinity gradient.

    Directory of Open Access Journals (Sweden)

    Henk Bolhuis

    Full Text Available The North Sea coast of the Dutch barrier island of Schiermonnikoog is covered by microbial mats that initiate a succession of plant communities that eventually results in the development of a densely vegetated salt marsh. The North Sea beach has a natural elevation running from the low water mark to the dunes resulting in gradients of environmental factors perpendicular to the beach. These gradients are due to the input of seawater at the low water mark and of freshwater from upwelling groundwater at the dunes and rainfall. The result is a natural and dynamic salinity gradient depending on the tide, rainfall and wind. We studied the microbial community composition in thirty three samples taken every ten meters along this natural salinity gradient by using denaturing gradient gel electrophoresis (DGGE of rRNA gene fragments. We looked at representatives from each Domain of life (Bacteria, Archaea and Eukarya and with a particular emphasis on Cyanobacteria. Analysis of the DGGE fingerprints together with pigment composition revealed three distinct microbial mat communities, a marine community dominated by diatoms as primary producers, an intermediate brackish community dominated by Cyanobacteria as primary producers and a freshwater community with Cyanobacteria and freshwater green algae.

  18. Lipid Biomarkers for a Hypersaline Microbial Mat Community

    Science.gov (United States)

    Jahnke, Linda L.; Embaye, Tsege; Turk, Kendra A.

    2003-01-01

    The use of lipid biomarkers and their carbon isotopic compositions are valuable tools for establishing links to ancient microbial ecosystems. As witnessed by the stromatolite record, benthic microbial mats grew in shallow water lagoonal environments where microorganisms had virtually no competition apart from the harsh conditions of hypersalinity, desiccation and intense light. Today, the modern counterparts of these microbial ecosystems find appropriate niches in only a few places where extremes eliminate eukaryotic grazers. Answers to many outstanding questions about the evolution of microorganisms and their environments on early Earth are best answered through study of these extant analogs. Lipids associated with various groups of bacteria can be valuable biomarkers for identification of specific groups of microorganisms both in ancient organic-rich sedimentary rocks (geolipids) and contemporary microbial communities (membrane lipids). Use of compound specific isotope analysis adds additional refinement to the identification of biomarker source, so that it is possible to take advantage of the 3C-depletions associated with various functional groups of organisms (i.e. autotrophs, heterotrophs, methanotrophs, methanogens) responsible for the cycling of carbon within a microbial community. Our recent work has focused on a set of hypersaline evaporation ponds at Guerrero Negro, Baja California Sur, Mexico which support the abundant growth of Microcoleus-dominated microbial mats. Specific biomarkers for diatoms, cyanobacteria, archaea, green nonsulfur (GNS), sulfate reducing, and methanotrophic bacteria have been identified. Analyses of the ester-bound fatty acids indicate a highly diverse microbial community, dominated by photosynthetic organisms at the surface.

  19. Zirconium Hydroxide-coated Nanofiber Mats for Nerve Agent Decontamination.

    Science.gov (United States)

    Kim, Sohee; Ying, Wu Bin; Jung, Hyunsook; Ryu, Sam Gon; Lee, Bumjae; Lee, Kyung Jin

    2017-03-16

    Diverse innovative fabrics with specific functionalities have been developed for requirements such as self-decontamination of chemical/biological pollutants and toxic nerve agents. In this work, Zr(OH) 4 -coated nylon-6,6 nanofiber mats were fabricated for the decontamination of nerve agents. Nylon-6,6 fabric was prepared via the electrospinning process, followed by coating with Zr(OH) 4 , which was obtained by the hydrolysis of Zr(OBu) 4 by a sol-gel reaction on nanofiber surfaces. The reaction conditions were optimized by varying the amounts of Zr(OBu) 4 ,the reaction time, and the temperature of the sol-gel reaction. The composite nanofibers show high decontamination efficiency against diisopropylfluorophosphate, which is a nerve agent analogue, due to its high nucleophilicity that aids in the catalysis of the hydrolysis of the phosphonate ester bonds. Composite nanofiber mats have a large potential and can be applied in specific fields such as military and medical markets. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Dynamic Load Measurement of Ballistic Gelatin Impact Using an Instrumented Tube

    Science.gov (United States)

    Seidt, J. D.; Periira, J. M.; Hammer, J. T.; Gilat, A.; Ruggeri, C. R.

    2012-01-01

    Bird strikes are a common problem for the aerospace industry and can cause serious damage to an aircraft. Ballistic gelatin is frequently used as a surrogate for actual bird carcasses in bird strike tests. Numerical simulations of these tests are used to supplement experimental data, therefore it is necessary to use numerical modeling techniques that can accurately capture the dynamic response of ballistic gelatin. An experimental technique is introduced to validate these modeling techniques. A ballistic gelatin projectile is fired into a strike plate attached to a 36 in. long sensor tube. Dynamic load is measured at two locations relative to the strike plate using strain gages configured in a full Wheatstone bridge. Data from these experiments are used to validate a gelatin constitutive model. Simulations of the apparatus are analyzed to investigate its performance.

  1. A gelatin composite scaffold strengthened by drug-loaded halloysite nanotubes.

    Science.gov (United States)

    Ji, Lijun; Qiao, Wei; Zhang, Yuheng; Wu, Huayu; Miao, Shiyong; Cheng, Zhilin; Gong, Qianming; Liang, Ji; Zhu, Aiping

    2017-09-01

    Mechanical properties and anti-infection are two of the most concerned issues for artificial bone grafting materials. Bone regeneration porous scaffolds with sustained drug release were developed by freeze-drying the mixture of nanosized drug-loaded halloysite nanotubes (HNTs) and gelatin. The scaffolds showed porous structure and excellent biocompatibility. The mechanical properties of the obtained composite scaffolds were enhanced significantly by HNTs to >300%, comparing to those of gelatin scaffold, and match to those of natural cancellous bones. The ibuprofen-loaded HNTs incorporated in the scaffolds allowed extended drug release over 100h, comparing to 8h when directly mixed the drug into the gelatin scaffold. The biological properties of the composite scaffolds were investigated by culturing MG63 cells on them. The HNTs/gelatin scaffolds with excellent mechanical properties and sustained drug release could be a promising artificial bone grating material. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Sodium alginate/gelatin with silica nanoparticles a novel hydrogel for 3D printing

    Science.gov (United States)

    Soni, Raghav; Roopavath, Uday Kiran; Mahanta, Urbashi; Deshpande, A. S.; Rath, S. N.

    2018-05-01

    Sodium alginate/gelatin hydrogels are promising materials for 3D bio-printing due to its good biocompatibility and biodegradability. Gelatin is used for thermal crosslinking and its cell adhesion properties. Hence patient specific sodium alginate/gelatin hydrogel scaffolds can be bio-fabricated in a temperature range of 4-14 oC. In this study we made an attempt to introduce silica (SiO2) nanoparticles in the polymer network of sodium alginate (2.5%)/gelatin (8%) hydrogel at different concentrations (w/v) as 0%, 1.25%, 2.5%, 5%, and 7.5%. The effect of silica nanoparticles on viscosity, swelling behavior, and degradation rate are analyzed. Hydrogels with 5% silica nanoparticles show significantly less swelling and degradation when compared to other concentrations. The viscosity of the hydrogels gradually increases up to 5% addition of silica nanoparticles enhancing the stability of 3D printed structures.

  3. Enzyme immunoassay for the detection of porcine gelatine in edible bird's nests.

    Science.gov (United States)

    Tukiran, Nur Azira; Ismail, Amin; Mustafa, Shuhaimi; Hamid, Muhajir

    2015-01-01

    Porcine gelatine is a common adulterant found in edible bird's nests (EBNs) used to increase the net weight prior to sale. This study aimed to develop indirect enzyme-linked immunosorbent assays (ELISAs) for porcine gelatine adulteration using anti-peptide polyclonal antibodies. Three indirect ELISAs were developed (PAB1, 2 and 3), which had limits of detection (LODs) of 0.12, 0.10 and 0.11 µg g(-1), respectively. When applied to standard solutions of porcine gelatine, the inter- and intra-assays showed coefficients of variation (CVs) less than 20% and were able to detect at least 0.5 ng µg(-1) (0.05%) porcine gelatine in spiked samples. The proposed ELISA offers attractions for quality control in the EBN industry.

  4. Algorithms Development in Detection of the Gelatinization Process during Enzymatic ‘Dodol’ Processing

    Directory of Open Access Journals (Sweden)

    Azman Hamzah

    2013-09-01

    Full Text Available Computer vision systems have found wide application in foods processing industry to perform quality evaluation. The systems enable to replace human inspectors for the evaluation of a variety of quality attributes. This paper describes the implementation of the Fast Fourier Transform and Kalman filtering algorithms to detect the glutinous rice flour slurry (GRFS gelatinization in an enzymatic „dodol. processing. The onset of the GRFS gelatinization is critical in determining the quality of an enzymatic „dodol.. Combinations of these two algorithms were able to detect the gelatinization of the GRFS. The result shows that the gelatinization of the GRFS was at the time range of 11.75 minutes to 14.75 minutes for 24 batches of processing. This paper will highlight the capability of computer vision using our proposed algorithms in monitoring and controlling of an enzymatic „dodol. processing via image processing technology.

  5. New polymeric formulation for control of biomphalaria Alexandria based on pharmaceutical waste gelatin

    International Nuclear Information System (INIS)

    Kenawy, E.; El-Maghraby, A.

    2005-01-01

    In the recent years, important new areas of application for plastics have emerged in medicine such as devices for the controlled release of drugs. The increases in the use of plastic materials in all sectors of industry have led to a continuous increase in the generation of plastic wastes. Recycling allow the waste to be reintroduced into the consumption cycle. Pharmaceutical companies which manufacture soft gels with different shapes, sizes and colors based mainly on gelatin formulations produce huge amount of gelatin waste. Schistosomiasis is one of the most important public health problems in our country. We now report the utilization of gelatin scrap by incorporating them in biodegradable films containing the molluscicide niclosamide for control of Biomphalaria Alexandrina snails. The preparation of the gelatin films will be described. The release of niclosamide from the prepared blends was investigated. The prepared formulations proved to be useful compared with free niclosamide

  6. [Use of "gelatamp" colloidal silver gelatin sponge to prevent dry socket after extracting mandibular impacted teeth].

    Science.gov (United States)

    Wang, Yao-zhong; Guan, Qun-li; Li, Ya-xin; Guo, Ji-lai; Jiang, Ling; Jia, Mu-yun; Deng, Yue

    2013-02-01

    To study the clinical effect of "gelatamp" colloidal silver gelatin sponge on preventing dry socket after extracting the mandibular impacted teeth. 1350 teeth extracted from 976 patients who needed to extract the mandibular impacted teeth were divided into group A, group B and group C randomly. "Gelatamp" colloidal silver gelatin sponge was implanted into alveolar socket after teeth extraction in group A, with absorbable gelatin sponge was implanted into alveolar socket in group B and nothing was implanted into alveolar socket in group C. The incidence of dry socket was observed, the data was analyzed using SPSS10.0 software package. The incidence of dry socket was 0.44% in group A, 2% in group B and 4.44% in group C. There was significant difference in the incidence of dry socket between group A and group C(Pcolloidal silver gelatin sponge can prevent the occurrence of dry socket after teeth extraction, which is of wide clinical use.

  7. Determination of the gelatinization temperature of starch presented in maize flours

    Energy Technology Data Exchange (ETDEWEB)

    Coral, D F; Pineda-Gomez, P; Rosales-Rivera, A [Laboratorio de Magnetismo y Materiales Avanzados, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Manizales, Caldas (Colombia); Rodriguez-Garcia, M E, E-mail: dfcoralc@unal.edu.c [Departamento de Nanotecnologia, Centro de Fisica Aplicada y Tecnologia Avanzada, UNAM, Queretaro, Qro. (Mexico)

    2009-05-01

    A study of the influence of the moisture and the grain size on the gelatinization temperature (Tp1) of starch from four industrial maize flours as well as an unprocessed maize sample is presented. The gelatinization is a phase transition that can be observed using Differential Scanning Calorimetry (DSC), and it is manifest as an endothermic peak in the DSC thermogram. Results show that for 60, 65, 70 and 75% of moisture, the endothermic peak temperature increases from 70 to 75 deg. C when the moisture increases, and decrease when the grain size increases from 250 to 420mum. A study of the gelatinization enthalpy (DELTAHp) is also presented, this is related with the gelatinized starch present in the sample. The enthalpy decrease when the moisture increases and it decrease when grain size is increased.

  8. Algorithms Development in Detection of the Gelatinization Process during Enzymatic ‘Dodol’ Processing

    Directory of Open Access Journals (Sweden)

    Azman Hamzah

    2007-11-01

    Full Text Available Computer vision systems have found wide application in foods processing industry to perform the quality evaluation. The systems enable to replace human inspectors for the evaluation of a variety of quality attributes. This paper describes the implementation of the Fast Fourier Transform and Kalman filtering algorithms to detect the glutinous rice flour slurry (GRFS gelatinization in an enzymatic ‘dodol’ processing. The onset of the GRFS gelatinization is critical in determining the quality of an enzymatic ‘dodol’. Combinations of these two algorithms were able to detect the gelatinization of the GRFS. The result shows that the gelatinization of the GRFS was at the time range of 11.75 minutes to 15.33 minutes for 20 batches of processing. This paper will highlight the capability of computer vision using our proposed algorithms in monitoring and controlling of an enzymatic ‘dodol’ processing via image processing technology.

  9. Laser Fabrication of 3D Gelatin Scaffolds for the Generation of Bioartificial Tissues

    Directory of Open Access Journals (Sweden)

    Mathias Wilhelmi

    2011-01-01

    Full Text Available In the present work, the two-photon polymerization (2PP technique was applied to develop precisely defined biodegradable 3D tissue engineering scaffolds. The scaffolds were fabricated via photopolymerization of gelatin modified with methacrylamide moieties. The results indicate that the gelatin derivative (GelMod preserves its enzymatic degradation capability after photopolymerization. In addition, the developed scaffolds using 2PP support primary adipose-derived stem cell (ASC adhesion, proliferation and differentiation into the anticipated lineage.

  10. A Non-destructive and Continuous Measurement of Gelatinization of Rice in Rice Cooking Process

    OpenAIRE

    Hagura, Yoshio; Suzuki, Kanichi

    2002-01-01

    A non-destructive and continuous method to measure gelatinization of rice samples in a rice-water system during rice cooking process was examined. An aluminum pot and a lid of a rice cooker were used as two electrode plates, and changes in dielectric properties (capacitance : C, and dielectric dissipation factor : tan δ) of the samples in the rice cooking process were measured by a capacitance meter. Differential scanning calorimetry (DSC) was used to measure gelatinization enthalpy and to de...

  11. Influence of palm oil and glycerol on properties of fish skin gelatin-based films.

    Science.gov (United States)

    Nilsuwan, Krisana; Benjakul, Soottawat; Prodpran, Thummanoon

    2016-06-01

    Properties of fish skin gelatin film incorporated with palm oil at 50 and 75 % (w/w) as affected by glycerol at 0-30 % (w/w) were investigated. Increases in water vapour permeability and elongation at break along with decrease in tensile strength were noticed when levels of glycerol were increased (p fish skin gelatin films without drastic alteration of mechanical properties.

  12. EKSTRAKSI GELATIN DARI KAKI AYAM BROILER MELALUI BERBAGAI LARUTAN ASAM DAN BASA DENGAN VARIASI LAMA PERENDAMAN

    Directory of Open Access Journals (Sweden)

    Muhammad Rasyid Indrawan

    2016-12-01

    Full Text Available Gelatin is a biopolymer that can be obtained from partially hydrolysis of collagen present in skin, bone, and connective tissues of animals This study used chicken Broiler feet as a source of collagen. This study was conducted to determine the effect of soaking treatment with solution of acid and base, and with variety of soaking time. The solution used is HCl, CH3COOH, and NaOH with different concentration. The process of soaking followed by extraction, filtration, and drying to obtain a sheet of gelatin. Gelatin was analyzed qualitatively with chemical reaction. The best results of yield can be obtained from various methods of soaking given by HCl 2% for 2 days, CH3COOH 2% for 3 days, and NaOH 2% for 1 day. Keywords : Gelatin, Chicken feet Broiler’s, Acid-treated, Alkali-treated ABSTRAK Gelatin merupakan biopolimer yang biasanya diperoleh dari hidrolisis parsial kolagen jaringan kulit, tulang, dan jaringan ikat hewan. Penelitian ini menggunakan kaki ayam broiler sebagai sumber kolagen. Penelitian dilakukan untuk melihat pengaruh perlakuan perendaman kaki ayam broiler melalui berbagai larutan asam dan basa dengan variasi lama perendaman. Larutan yang digunakan yaitu HCl, CH3COOH, dan NaOH dengan berbagai konsentrasi. Proses perendaman dilanjutkan dengan ekstraksi, filtrasi, dan pengeringan untuk mendapatkan lembaran gelatin. Gelatin yang diperoleh dianalisis secara kualitatif melalui reaksi kimia. Hasil rendemen terbaik dapat diperoleh dari berbagai metode perendaman yaitu HCl 2% selama 2 hari, CH3COOH 2% selama 3 hari, dan NaOH 2% selama 1 hari. Kata Kunci : Gelatin, Kaki ayam Broiler, Metode asam, Metode basa

  13. Low density, microcellular, dopable, agar/gelatin foams for pulsed power experiments

    Energy Technology Data Exchange (ETDEWEB)

    McNamara, W.F. [Orion International Technologies, Inc., Albuquerque, NM (United States); Aubert, J.H. [Sandia National Lab., Albuquerque, NM (United States)

    1997-04-01

    Low-density, microcellular foams prepared from the natural polymers agar and gelatin have been developed for pulsed-power physics experiments. Numerous experiments were supported with foams having densities at or below 10 mg/cm{sup 3}. For some of the experiments, the agar/gelatin foam was uniformly doped with metallic elements using soluble salts. Depending on the method of preparation, cell sizes were typically below 10 microns and for one process were below 1.0 micron.

  14. Photonic band gap effect and structural color from silver nanoparticle gelatin emulsion

    Science.gov (United States)

    Kok, Mang Hin; Ma, Rui; Lee, Jeffrey Chi Wai; Tam, Wing Yim; Chan, C. T.; Sheng, Ping; Cheah, Kok Wai

    2005-10-01

    We have fabricated planar structures of silver nanoparticles in monochromatic gelatin emulsion with a continuous spacing ranging from 0.15-0.40 micron using a two-beam interference of a single laser source. Our planar holograms display a colorful “rainbow” pattern and photonic bandgaps covering the visible and IR ranges. We model the planar silver nanoparticle-gelatin composite system using an effective medium approach and good agreement is obtained between theory and experiment.

  15. Gelatin- and starch-based hydrogels. Part A: Hydrogel development, characterization and coating.

    Science.gov (United States)

    Van Nieuwenhove, Ine; Salamon, Achim; Peters, Kirsten; Graulus, Geert-Jan; Martins, José C; Frankel, Daniel; Kersemans, Ken; De Vos, Filip; Van Vlierberghe, Sandra; Dubruel, Peter

    2016-11-05

    The present work aims at constructing the ideal scaffold matrix of which the physico-chemical properties can be altered according to the targeted tissue regeneration application. Ideally, this scaffold should resemble the natural extracellular matrix (ECM) as close as possible both in terms of chemical composition and mechanical properties. Therefore, hydrogel films were developed consisting of methacrylamide-modified gelatin and starch-pentenoate building blocks because the ECM can be considered as a crosslinked hydrogel network consisting of both polysaccharides and structural, signaling and cell-adhesive proteins. For the gelatin hydrogels, three different substitution degrees were evaluated including 31%, 72% and 95%. A substitution degree of 32% was applied for the starch-pentenoate building block. Pure gelatin hydrogels films as well as interpenetrating networks with gelatin and starch were developed. Subsequently, these films were characterized using gel fraction and swelling experiments, high resolution-magic angle spinning (1)H NMR spectroscopy, rheology, infrared mapping and atomic force microscopy. The results indicate that both the mechanical properties and the swelling extent of the developed hydrogel films can be controlled by varying the chemical composition and the degree of substitution of the methacrylamide-modified gelatin applied. The storage moduli of the developed materials ranged between 14 and 63kPa. Phase separation was observed for the IPNs for which separated starch domains could be distinguished located in the surrounding gelatin matrix. Furthermore, we evaluated the affinity of aggrecan for gelatin by atomic force microscopy and radiolabeling experiments. We found that aggrecan can be applied as a bioactive coating for gelatin hydrogels by a straightforward physisorption procedure. Thus, we achieved distinct fine-tuning of the physico-chemical properties of these hydrogels which render them promising candidates for tissue engineering

  16. Application Specific Optical Fibers

    OpenAIRE

    Pal, Bishnu P.

    2010-01-01

    In this chapter we have attempted to provide a unified summary description of the most important propagation characteristics of an optical fiber followed by discussion on several variety of special fibers for realizing fiber amplifiers, dispersion compensating fibers, microstructured optical fibers, and so on. Even though huge progress has been made on development of optical fibers for telecom application, a need for developing special fibers, not necessarily for telecom alone, has arisen. Th...

  17. Smart pillow for heart-rate monitoring using a fiber optic sensor

    Science.gov (United States)

    Chen, Zhihao; Teo, Ju Teng; Ng, Soon Huat; Yim, Huiqing

    2011-03-01

    In this paper, we propose and demonstrate a new method to monitor heart rate using fiber optic microbending based sensor for in-bed non-intrusive monitoring. The sensing system consists of transmitter, receiver, sensor mat, National Instrument (NI) data acquisition (DAQ) card and a computer for signal processing. The sensor mat is embedded inside a commercial pillow. The heart rate measurement system shows an accuracy of +/-2 beats, which has been successfully demonstrated in a field trial. The key technological advantage of our system is its ability to measure heart rate with no preparation and minimal compliance by the patient.

  18. Polycaprolactone-Polydiacetylene Electrospun Fibers for Colorimetric Detection of Fake Gasoline

    Directory of Open Access Journals (Sweden)

    Shamshad Ali

    2016-04-01

    Full Text Available PCDA (Pentacosadiynoic Acid monomers were successfully embedded in PCL (Poly ?-Caprolactone polymer matrix by electrospinning process for the first time. The resultant EFM (Electrospun Fibers Mat was photo-polymerized under 254 nm UV light that enables colorimetric detection of fake gasoline. Results revealed that the fake gasoline develops a red color mat within 5 sec. FE-SEM images showed that the fake gasoline treatment dissolved the PCL EFM that give access to interact with PDA polymer. The proposed litmus-type sensor based on PCL-PDA EFM is highly sensitive to fake gasoline and can be fabricated easily

  19. Designing the fiber volume ratio in SiC fiber-reinforced SiC ceramic composites under Hertzian stress

    International Nuclear Information System (INIS)

    Lee, Kee Sung; Jang, Kyung Soon; Park, Jae Hong; Kim, Tae Woo; Han, In Sub; Woo, Sang Kuk

    2011-01-01

    Highlights: → Optimum fiber volume ratios in the SiC/SiC composite layers were designed under Hertzian stress. → FEM analysis and spherical indentation experiments were undertaken. → Boron nitride-pyrocarbon double coatings on the SiC fiber were effective. → Fiber volume ratio should be designed against flexural stress. -- Abstract: Finite element method (FEM) analysis and experimental studies are undertaken on the design of the fiber volume ratio in silicon carbide (SiC) fiber-reinforced SiC composites under indentation contact stresses. Boron nitride (BN)/Pyrocarbon (PyC) are selected as the coating materials for the SiC fiber. Various SiC matrix/coating/fiber/coating/matrix structures are modeled by introducing a woven fiber layer in the SiC matrix. Especially, this study attempts to find the optimum fiber volume ratio in SiC fiber-reinforced SiC ceramics under Hertzian stress. The analysis is performed by changing the fiber type, fiber volume ratio, coating material, number of coating layers, and stacking sequence of the coating layers. The variation in the stress for composites in relation to the fiber volume ratio in the contact axial or radial direction is also analyzed. The same structures are fabricated experimentally by a hot process, and the mechanical behaviors regarding the load-displacement are evaluated using the Hertzian indentation method. Various SiC matrix/coating/fiber/coating/matrix structures are fabricated, and mechanical characterization is performed by changing the coating layer, according to the introduction (or omission) of the coating layer, and the number of woven fiber mats. The results show that the damage mode changes from Hertzian stress to flexural stress as the fiber volume ratio increases in composites because of the decreased matrix volume fraction, which intensifies the radial crack damage. The result significantly indicates that the optimum fiber volume ratio in SiC fiber-reinforced SiC ceramics should be designed for

  20. Preparation and physicochemistry properties of smart edible films based on gelatin-starch nanoparticles.

    Science.gov (United States)

    Tao, Furong; Shi, Chengmei; Cui, Yuezhi

    2018-04-24

    Among the natural polymers able to form edible films, starch and gelatin (Gel) are potential sources. Corn starch is a polysaccharide widely produced around the world, and gelatin differs from other hydrocolloids as a fully digestible protein, containing nearly all the essential amino acids, except tryptophan. Based on this, with advantages such as abundance, relatively low cost, biodegradability, and edibility, studies considering alternative systems for food protection that utilize biopolymers have increased significantly in the recent years. A novel macromolecular crosslinker Starch-BTCAD-NHS (starch - butanetetracarboxylic acid dianhydride - N-hydroxysuccinimide, SBN) was successfully prepared to modify gelatin film. Compared with the blank gelatin films, the resulting SBN-Gel films exhibited the improved surface hydrophobicity, the higher tense strength and elongation-at-break, the lower Young's modulus values, the greater opacity, the poorer water vapor uptake properties and better anti-degradation capacity. The modified gelatin film material with advanced properties obtained in this work was safe, stable eco-friendly and biorefractory, and was an ideal choice to form a packaging in food industry. Also, the crosslinking SBN-gelatin coating was effective in reducing the corruption and extending the shelf life for the peeled apple substantially. This article is protected by copyright. All rights reserved.

  1. Gelatin-based laser direct-write technique for the precise spatial patterning of cells.

    Science.gov (United States)

    Schiele, Nathan R; Chrisey, Douglas B; Corr, David T

    2011-03-01

    Laser direct-writing provides a method to pattern living cells in vitro, to study various cell-cell interactions, and to build cellular constructs. However, the materials typically used may limit its long-term application. By utilizing gelatin coatings on the print ribbon and growth surface, we developed a new approach for laser cell printing that overcomes the limitations of Matrigel™. Gelatin is free of growth factors and extraneous matrix components that may interfere with cellular processes under investigation. Gelatin-based laser direct-write was able to successfully pattern human dermal fibroblasts with high post-transfer viability (91% ± 3%) and no observed double-strand DNA damage. As seen with atomic force microscopy, gelatin offers a unique benefit in that it is present temporarily to allow cell transfer, but melts and is removed with incubation to reveal the desired application-specific growth surface. This provides unobstructed cellular growth after printing. Monitoring cell location after transfer, we show that melting and removal of gelatin does not affect cellular placement; cells maintained registry within 5.6 ± 2.5 μm to the initial pattern. This study demonstrates the effectiveness of gelatin in laser direct-writing to create spatially precise cell patterns with the potential for applications in tissue engineering, stem cell, and cancer research.

  2. Physicochemical properties, antimicrobial activity and oil release of fish gelatin films incorporated with cinnamon essential oil

    Directory of Open Access Journals (Sweden)

    Jiulin Wu

    2017-07-01

    Full Text Available Fish skin gelatin films incorporated with various concentrations of cinnamon essential oil (CEO were prepared and characterized. The results showed that tensile strength (TS, elongation at break (EAB, and water content (WC of the gelatin based film decreased with the increasing concentrations of CEO, but water vapor permeability (WVP increased. Addition of CEO improved light barrier property of the film. The Scanning electron microscope (SEM showed that the heterogeneous surface and porous formation appeared in gelatin-CEO films. Fourier transform infrared spectroscopy analyses (FTIR-ATR spectra indicated the interactions existed between gelatin and CEO. The gelatin-CEO films exhibited good inhibitory effects against the tested microorganisms (Escherichia coli, Staphylococcus aureus, Aspergillus niger, Rhizopus oryzae, and Paecilomyces varioti and their antifungal activity seemed to be more effective than the resistance to bacterial growth. In vitro release studies showed an initial burst effect of CEO release and that subsequently slowed down at 40 °C, but the initial burst release was not obvious at 4 °C. The obtained results suggested that incorporation of CEO as a natural antimicrobial agent into gelatin film has potential for developing as active food packaging.

  3. Preparation of Gelatin coated hydroxyapatite nanorods and the stability of its aqueous colloidal

    International Nuclear Information System (INIS)

    Chen Minfang; Tan Junjun; Lian Yuying; Liu Debao

    2008-01-01

    This paper describes a novel process for preparing Gelatin coated hydroxyapatite (HAp) nanorods to improve the stability of its aqueous colloid. As Gelatin is a typical protein with abundant hydroxyls, carboxys and imines, it is a very effective functional group to attach onto the surfaces of the HAp particles. Our data show that the Gelatin layer firmly coated on the hydroxyapatite nanorods, and their structure and interfacial chemical bonding have been studied using various techniques, such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), high-resolution transmission electron microscopy (HRTEM), differential thermal analysis (DTA) and thermal gravimetric analysis (TGA). The reaction temperature, pH, amount of Gelatin, and Ca/P molar ratio in the material determine the quality of Gelatin coating and the stability of the HAp in aqueous solution. Moreover, an interesting phenomenon was found that the Gelatin coated HAp sediment separated by centrifugal was easily dispersed in water and forms HAp aqueous suspension. The suspension was stable for more than 24 h

  4. Isolation of fish skin and bone gelatin from tilapia (Oreochromis niloticus): Response surface approach

    Science.gov (United States)

    Arpi, N.; Fahrizal; Novita, M.

    2018-03-01

    In this study, gelatin from fish collagen, as one of halal sources, was extracted from tilapia (Oreochromis niloticus) skin and bone, by using Response Surface Methodology to optimize gelatin extraction conditions. Concentrations of alkaline NaOH and acid HCl, in the pretreatment process, and temperatures in extraction process were chosen as independent variables, while dependent variables were yield, gel strength, and emulsion activity index (EAI). The result of investigation showed that lower NaOH pretreatment concentrations provided proper pH extraction conditions which combine with higher extraction temperatures resulted in high gelatin yield. However, gelatin emulsion activity index increased proportionally to the decreased in NaOH concentrations and extraction temperatures. No significant effect of the three independent variables on the gelatin gel strength. RSM optimization process resulted in optimum gelatin extraction process conditions using alkaline NaOH concentration of 0.77 N, acid HCl of 0.59 N, and extraction temperature of 66.80 °C. The optimal solution formula had optimization targets of 94.38%.

  5. Synthesis of biocompatible hydrophobic silica-gelatin nano-hybrid by sol-gel process.

    Science.gov (United States)

    Smitha, S; Shajesh, P; Mukundan, P; Nair, T D R; Warrier, K G K

    2007-03-15

    Silica-biopolymer hybrid has been synthesised using colloidal silica as the precursor for silica and gelatin as the biopolymer counterpart. The surface modification of the hybrid material has been done with methyltrimethoxysilane leading to the formation of biocompatible hydrophobic silica-gelatin hybrid. Here we are reporting hydrophobic silica-gelatin hybrid and coating precursor for the first time. The hybrid gel has been evaluated for chemical modification, thermal degradation, hydrophobicity, particle size, transparency under the UV-visible region and morphology. FTIR spectroscopy has been used to verify the presence of CH(3) groups which introduce hydrophobicity to the SiO2-MTMS-gelatin hybrids. The hydrophobic property has also been tailored by varying the concentration of methyltrimethoxysilane. Contact angle by Wilhelmy plate method of transparent hydrophobic silica-gelatin coatings has been found to be as high as approximately 95 degrees . Oxidation of the organic group which induces the hydrophobic character occurs at 530 degrees C which indicates that the surface hydrophobicity is retained up to that temperature. Optical transmittance of SiO2-MTMS-gelatin hybrid coatings on glass substrates has been found to be close to 100% which will enable the hybrid for possible optical applications and also for preparation of transparent biocompatible hydrophobic coatings on biological substrates such as leather.

  6. Use and application of gelatin as potential biodegradable packaging materials for food products.

    Science.gov (United States)

    Nur Hanani, Z A; Roos, Y H; Kerry, J P

    2014-11-01

    The manufacture and potential application of biodegradable films for food application has gained increased interest as alternatives to conventional food packaging polymers due to the sustainable nature associated with their availability, broad and abundant source range, compostability, environmentally-friendly image, compatibility with foodstuffs and food application, etc. Gelatin is one such material and is a unique and popularly used hydrocolloid by the food industry today due to its inherent characteristics, thereby potentially offering a wide range of further and unique industrial applications. Gelatin from different sources have different physical and chemical properties as they contain different amino acid contents which are responsible for the varying characteristics observed upon utilization in food systems and when being utilized more specifically, in the manufacture of films. Packaging films can be successfully produced from all gelatin sources and the behaviour and characteristics of gelatin-based films can be altered through the incorporation of other food ingredients to produce composite films possessing enhanced physical and mechanical properties. This review will present the current situation with respect to gelatin usage as a packaging source material and the challenges that remain in order to move the manufacture of gelatin-based films nearer to commercial reality. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Radiation synthesis and characterization of nanosilver/gelatin/carboxymethyl chitosan hydrogel

    International Nuclear Information System (INIS)

    Zhou Ying; Zhao Yinghui; Wang Lu; Xu Ling; Zhai Maolin; Wei Shicheng

    2012-01-01

    A series of antibacterial hydrogels were fabricated from an aqueous solution of AgNO 3 , gelatin and carboxymethyl chitosan (CM-chitosan) by radiation-induced reduction and crosslinking at ambient temperature. The nanosilver particles were in situ synthesized accompanying with the formation of gelatin/CM-chitosan hydrogel. Transmission Electron Microscope and UV–vis analysis have verified the formation and homogeneous distribution of nanosilver particles in the hydrogel matrix. The nanosilver/gelatin/CM-chitosan hydrogels possessed interconnected porous structure, had a compressive modulus of 44 to 56 kPa, and could absorb 62 to 108 times of deionized water to its dry weight. Furthermore, the hydrogels were found to have sound antibacterial effect on Escherichia coli (E. coli), and their antibacterial ability could be significantly enhanced by the increasing of AgNO 3 content. The comprehensive results of this study suggest that nanosilver/gelatin/CM-chitosan hydrogels have potential as an antibacterial wound dressing. - Highlights: ► Nanosilver/gelatin/CM-chitosan hydrogel was synthesized by radiation crosslinking. ► Nanosilver particles distributed homogeneously in the hydrogel. ► The size of nanosilver increased with the increase of AgNO 3 concentration. ► The nanosilver/gelatin/CM-chitosan hydrogel has antibacterial ability.

  8. Gelatin for purification and proliferation of primary keratinocyte culture for use in chronic wounds and burns.

    Science.gov (United States)

    Rahsaz, Marjan; Geramizadeh, Bita; Kaviani, Maryam; Marzban, Saeed

    2015-04-01

    Human epidermal keratinocytes are currently established as a treatment for burns and wounds and have laboratory applications. Keratinocyte culture contamination by unwanted cells and inhibition of cell proliferation are barriers in primary keratinocyte culture. According to the recent literature, these cells are hard to culture. The present study was conducted to evaluate the efficacy of gelatin-coated surfaces in keratinocyte cultures. After enzymatic isolation of keratinocytes from normal epidermis by trypsin, the cells were cultured on gelatin-coated flasks in serum-free medium. Another group of cells were cultured as a control group without gelatin coating. We showed positive effects of surface coating with gelatin on the primary culture of keratinocytes. Culture of these cells on a gelatincoated surface showed better proliferation with suitable morphology. By using gelatin, adhesion of these cells to the surface was more efficient and without contamination by small round cells. Successful primary culture of keratinocytes on a gelatin-coated surface may provide better yield and optimal number of cells for research and clinical applications.

  9. Preparation of reduced graphene oxide/gelatin composite films with reinforced mechanical strength

    International Nuclear Information System (INIS)

    Wang, Wenchao; Wang, Zhipeng; Liu, Yu; Li, Nan; Wang, Wei; Gao, Jianping

    2012-01-01

    Highlights: ► We used and compared different proportion of gelatin and chitosan as reducing agents. ► The mechanical properties of the films are investigated, especially the wet films. ► The cell toxicity of the composite films as biomaterial is carried out. ► The water absorption capabilities of the composite films also studied. -- Abstract: Graphene oxide (GO) was reduced by chitosan/gelatin solution and added to gelatin (Gel) to fabricate reduced graphene oxide/gelatin (RGO/Gel) films by a solvent-casting method using genipin as cross-linking agent. The structure and properties of the films were characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), thermogravimetric analysis (TGA) and UV–vis spectroscopy. The addition of RGO increased the tensile strength of the RGO/Gel films in both dry and wet states, but decreased their elongation at break. The incorperation of RGO also decreased the swelling ability of the films in water. Cell cultures were carried out in order to test the cytotoxicity of the films. The cells grew and reproduced well on the RGO/Gel films, indicating that the addition of RGO has no negative effect on the compatibility of the gelatin. Therefore, the reduced graphene oxide/gelatin composite is a promising biomaterial with excellent mechanical properties and good cell compatibility.

  10. Properties of gelatin-based films incorporated with chitosan-coated microparticles charged with rutin.

    Science.gov (United States)

    Dammak, Ilyes; Bittante, Ana Mônica Quinta Barbosa; Lourenço, Rodrigo Vinicius; do Amaral Sobral, Paulo José

    2017-08-01

    The aim of this study was development an active film based on gelatin incorporated with antioxidant, rutin carried into microparticles. The complexation between oppositely charged lecithin and chitosan was applied to prepare the chitosan-coated microparticles. The generated microparticles had an average size of 520±4nm and a span of 0.3 were formulated by a rotor-stator homogenize at the homogenization speed 10,000rpm. Composite films were prepared by incorporating chitosan-coated microparticles, at various concentrations (0.05, 0.1, 0.5, or 1% (based on the weight of the gelatin powder)) in the gelatin-based films. For the prepared films, the results showed that obtained physicochemical, water vapor barrier, and mechanical were compared with native gelatin film with a slight decrease for chitosan concentration higher than 0.5%. The microstructure studies done by scanning electron microscopes, revealed different micropores embedded with oil resulting from the incorporation of the microparticles into the gelatin matrix. Moreover, the calorimetric results were comparable to those of gelatin control film with T g value 45°C and increased crystallinity percentage with increasing incorporation of microparticles. This original concept of composite biodegradable films may thus be a good alternative to incorporate liposoluble active compounds to design an active packaging with good properties. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Preparation of Rhodamine B Fluorescent Poly(methacrylic acid Coated Gelatin Nanoparticles

    Directory of Open Access Journals (Sweden)

    Zhenhai Gan

    2011-01-01

    Full Text Available Poly(methacrylic acid (PMAA-coated gelatin nanoparticles encapsulated with fluorescent dye rhodamine B were prepared by the coacervation method with the aim to retard the release of rhodamine B from the gelatin matrix. With sodium sulfate as coacervation reagent for gelatin, a kind of biopolymer with excellent biocompatibility, the formed gelatin nanoparticles were cross-linked by formaldehyde followed by the polymerization of methacrylic acid coating. The fluorescent poly(methacrylic acid coated gelatin (FPMAAG nanoparticles had a uniform spherical shape and a size distribution of 60±5 nm. Infrared spectral analysis confirmed the formation of PMAA coating on the gelatin nanoparticles. Based on UV-Vis spectra, the loading efficiency of rhodamine B for the FPMAAG nanoparticles was 0.26 μg per mg nanoparticles. The encapsulated rhodamine B could sustain for two weeks. Favorable fluorescence property and fluorescence imaging of cells confirmed that the FPMAAG nanoparticles have promising biochemical, bioanalytical, and biomedical applications.

  12. Traceability System Model for Quality Gelatin Raw Material of Cattle Hides

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    S Nur

    2010-09-01

    Full Text Available Several criteria must be accomplished within the provision of quality products in terms of the types of materials, the processing methods and effort to get it. Traceability system involves various parties that have different needs and goals in the process of supplying raw materials. Hence, there is a need for institutional systems engineering that can organize and manage the tracking process, the procurement of raw materials that guarantee the origin of gelatin raw materials, and facilitate the industry and customer to create a standardized quality of product. The purpose of the study formulates the institutional tracking models of gelatin raw material from cattle hide based on various criteria and assessment of the expert opinion. The methods used in this study were Interpretative structural modeling to formulate a representation of institutional tracking efficiently and analytical hierarchy process to determine the tracking strategy of industrial gelatin raw materials from cowhide. The results obtained from the study were some key elements of institutional tracking model for industrial gelatin raw materials from cowhide and the traceability strategies for industrial raw materials from cattle hide gelatin Indonesia. (Animal Production 12(3: 190-198 (2010 Key Words: traceability, institutional model, cattle hide, gelatin

  13. Cytocompatible and water stable ultrafine protein fibers for tissue engineering

    Science.gov (United States)

    Jiang, Qiuran

    This dissertation proposal focuses on the development of cytocompatible and water stable protein ultrafine fibers for tissue engineering. The protein-based ultrafine fibers have the potential to be used for biomedicine, due to their biocompatibility, biodegradability, similarity to natural extracellular matrix (ECM) in physical structure and chemical composition, and superior adsorption properties due to their high surface to volume ratio. However, the current technologies to produce the protein-based ultrafine fibers for biomedical applications still have several problems. For instance, the current electrospinning and phase separation technologies generate scaffolds composed of densely compacted ultrafine fibers, and cells can spread just on the surface of the fiber bulk, and hardly penetrate into the inner sections of scaffolds. Thus, these scaffolds can merely emulate the ECM as a two dimensional basement membrane, but are difficult to mimic the three dimensional ECM stroma. Moreover, the protein-based ultrafine fibers do not possess sufficient water stability and strength for biomedical applications, and need modifications such as crosslinking. However, current crosslinking methods are either high in toxicity or low in crosslinking efficiency. To solve the problems mentioned above, zein, collagen, and gelatin were selected as the raw materials to represent plant proteins, animal proteins, and denatured proteins in this dissertation. A benign solvent system was developed specifically for the fabrication of collagen ultrafine fibers. In addition, the gelatin scaffolds with a loose fibrous structure, high cell-accessibility and cell viability were produced by a novel ultralow concentration phase separation method aiming to simulate the structure of three dimensional (3D) ECM stroma. Non-toxic crosslinking methods using citric acid as the crosslinker were also developed for electrospun or phase separated scaffolds from these three proteins, and proved to be

  14. Theoretical and experimental study of the effect of fiber heads on the mechanical properties of non-continuous basalt fiber reinforced composites

    Directory of Open Access Journals (Sweden)

    2007-02-01

    Full Text Available The effect of basalt fibers, produced by the Junkers technology and used as reinforcement in polymer composites, was modeled on the properties of composites, adapting the statistical fiber mat model of Poisson type. The random distribution was approximated by so-called effective spheres that act as defect sites in composites, reducing their strength. The role of fiber heads in strength reduction and the corresponding failure modes were analyzed theoretically using a model and by experiments performed on specimens containing a single fiber head located at different distances from the crack initiation. The applicability of the model was proven both experimentally and by finite element analysis. Based on all these investigations, the effective cross section reduction, and hence the strength reduction (predicted by the model caused by the presence of fiber heads was proven.

  15. Implantable biodegradable sponges: effect of interpolymer complex formation of chitosan with gelatin on the release behavior of tramadol hydrochloride.

    Science.gov (United States)

    Foda, Nagwa H; El-laithy, Hanan M; Tadros, Mina I

    2007-01-01

    The effect of interpolymer complex formation between positively charged chitosan and negatively charged gelatin (Type B) on the release behavior of tramadol hydrochloride from biodegradable chitosan-gelatin sponges was studied. Mixed sponges were prepared by freeze-drying the cross-linked homogenous stable foams produced from chitosan and gelatin solutions where gelatin acts as a foam builder. Generation of stable foams was optimized where concentration, pH of gelatin solution, temperature, speed and duration of whipping process, and, chitosan-gelatin ratio drastically affect the properties and the stability of the produced foams. The prepared sponges were evaluated for their morphology, drug content, and microstructure using scanning electron microscopy, mechanical properties, uptake capacity, drug release profile, and their pharmacodynamic activity in terms of the analgesic effect after implantation in Wistar rats. It was revealed that whipping 7% (w/w) gelatin solution, of pH 5.5, for 15 min at 25 degrees C with a stirring speed of 1000 rpm was the optimum conditions for stable gelatin foam generation. Moreover, homogenous, uniform chitosan-gelatin foam with small air bubbles were produced by mixing 2.5% w/w chitosan solution with 7% w/w gelatin solution in 1:5 ratio. Indeed, polyionic complexation between chitosan and gelatin overcame the drawbacks of chitosan sponge mechanical properties where, pliable, soft, and compressible sponge with high fluid uptake capacity was produced at 25 degrees C and 65% relative humidity without any added plasticizer. Drug release studies showed a successful retardation of the incorporated drug where the t50% values of the dissolution profiles were 0.55, 3.03, and 4.73 hr for cross-linked gelatin, un-cross-linked chitosan-gelatin, and cross-linked chitosan-gelatin sponges, respectively. All the release experiments followed Higuchi's diffusion mechanism over 12 hr. The achieved drug prolongation was a result of a combined effect

  16. Microbial mat structures in profile: The Neoproterozoic Sonia Sandstone, Rajasthan, India

    Science.gov (United States)

    Samanta, Pradip; Mukhopadhyay, Soumik; Mondal, Anudeb; Sarkar, Subir

    2011-01-01

    Ubiquitous microorganisms, especially cyanobacteria preferably grow on the sediment surface thereby producing microbial mats. In the absence of grazers and bioturbators, microbial mat is a unique feature of the Proterozoic. Most of the papers so far published described a wide variety of bed surface microbial mat structures with rare illustrations from sections perpendicular to bedding. Nonetheless, bed surface exposures are relatively rare in rock records. This limitation of bed surface exposures in rock records suggest that a study of microbial mats in bed-across sections is needed. The 60 m thick coastal marine interval of the Sonia Sandstone Formation is bounded between two terrestrial intervals, a transgressive lag at the base and an unconformity at the top, and has been chosen for exploration of microbial mat structures in bed-across sections. A wide variety of microbial mat-induced structures in bed-across sections are preserved within the coastal interval of the Sonia Sandstone. Though many of these structures are similar in some aspects with bed surface structures, some of those presented here are new. The palaeogeographic range of these microbial structures extends from supralittoral to neritic. Diagenetic alterations of microbial mats produce pyrite and those zones are suitable for the preservation of microbial remains. SEM and EDAX analyses show fossil preservation of filamentous microbial remains that confirm the presence of microbial mats within the coastal interval of the Sonia Sandstone. Effects of proliferation of microbial mats in the siliciclastic depositional setting are numerous. The mat-cover on sediment surfaces hinders reworking and/or erosion of the sediments thereby increases the net sedimentation rate. Successive deposition and preservation of thick microbial mat layer under reducing environments should have a great potential for hydrocarbon production and preservation and therefore these Proterozoic formations could be a target for

  17. Micro- and macrostructural characterization of polyvinylpirrolidone rotary-spun fibers.

    Science.gov (United States)

    Sebe, István; Kállai-Szabó, Barnabás; Kovács, Krisztián Norbert; Szabadi, Enikő; Zelkó, Romána

    2015-01-01

    The application of high-speed rotary spinning can offer a useful mean for either preparation of fibrous intermediate for conventional dosage forms or drug delivery systems. Polyvinylpyrrolidone (PVP) and poly(vinylpyrrolidone-vinylacetate) (PVP VA) micro- and nanofibers of different polymer concentrations and solvent ratios were prepared with a high-speed rotary spinning technique. In order to study the influence of parameters that enable successful fiber production from polymeric viscous solutions, a complex micro- and macrostructural screening method was implemented. The obtained fiber mats were subjected to detailed morphological analysis using scanning electron microscope (SEM), and rheological measurements while the microstructural changes of fiber samples, based on the free volume changes, was analyzed by positron annihilation lifetime spectroscopy (PALS) and compared with their mechanical characteristics. The plasticizing effect of water tracked by ortho-positronium lifetime changes in relation to the mechanical properties of fibers. A concentration range of polyvinylpyrrolidone solutions was defined for the preparation of fibers of optimum fiber morphology and mechanical properties. The method enabled fiber formulation of advantageous functionality-related properties for further formulation of solid dosage forms.

  18. Optimization of Polymer-ECM Composite Scaffolds for Tissue Engineering: Effect of Cells and Culture Conditions on Polymeric Nanofiber Mats