Browsing by Subject "Mammals"

Now showing 1 - 7 of 7

Open Access
Biocatalytic protein membranes fabricated by electrospinning
(Elsevier B.V., 2016) Kabay, G.; Kaleli, G.; Sultanova, Z.; Ölmez, T. T.; Şeker, U. Ö. Ş.; Mutlu, M.
In this study, a protein-based catalytic membrane was produced by electrospinning. Membrane activity was characterised in terms of response current for various glucose concentrations. We focused on the preparation of a scaffold by converting a globular protein to other structural forms using catastrophic solvents. A scaffolding protein, bovine serum albumin, and an enzyme, glucose oxidase (GOD), were selected as a model natural carrier matrix and a biologically active agent, respectively. Beta-mercaptoethanol (β-ME) was used to convert the globular protein to an amyloid-like form. A structural stabilising agent, 2,2,2-triflouroethanol (TFE), was used to maintain the final α-helical structure of the amyloid-like protein. The TFE:PBS (phosphate-buffered saline) ratio and various electrospinning parameters were analysed to minimise activity loss. Using this approach, we applied electrospinning to an active enzyme to obtain biocatalytic nanofibrous membranes. After optimising the protein electrospinning process, the activities of the protein nanofibrous membranes were monitored. GOD remained active in the new membrane structure. The highest enzyme activity was observed for the membranes prepared with a 1.5:1 (v:v) TFE:PBS solvent ratio. In that particular case, the immobilized enzyme created a current of 0.7 μA and the apparent activity was 2547 ± 132 U/m2.
Open Access
Computer vision based unistroke keyboard system and mouse for the handicapped
(IEEE, 2003-07) Erdem, M .Erkut; Erdem, İ. Aykut; Atalay, Volkan; Çetin, A. Enis
In this paper, a unistroke keyboard based on computer vision is described for the handicapped. The keyboard can be made of paper or fabric containing an image of a keyboard, which has an upside down U-shape. It can even be displayed on a computer screen. Each character is represented by a non-overlapping rectangular region on the keyboard image and the user enters a character by illuminating a character region with a laser pointer. The keyboard image is monitored by a camera and illuminated key locations are recognized. During the text entry process the user neither have to turn the laser light off nor raise the laser light from the keyboard. A disabled person who has difficulty using his/her hands may attach the laser pointer to an eyeglass and easily enter text by moving his/her head to point the laser beam on a character location. In addition, a mouse-like device can be developed based on the same principle. The user can move the cursor by moving the laser light on the computer screen which is monitored by a camera. © 2003 IEEE.
Open Access
Diabetic wound regeneration using heparin-mimetic peptide amphiphile gel in db/db mice
(Royal Society of Chemistry, 2017) Senturk, Berna; Demircan, Burak M.; Ozkan, Alper D.; Tohumeken, Sehmus; Delibasi, T.; Güler, Mustafa O.; Tekinay, Ayse B.
There is an urgent need for more efficient treatment of chronic wounds in diabetic patients especially with a high risk of leg amputation. Biomaterials capable of presenting extracellular matrix-mimetic signals may assist in the recovery of diabetic wounds by creating a more conducive environment for blood vessel formation and modulating the immune system. In a previous study, we showed that glycosaminoglycan-mimetic peptide nanofibers are able to increase the rate of closure in STZ-induced diabetic rats by induction of angiogenesis. The present study investigates the effect of a heparin-mimetic peptide amphiphile (PA) nanofiber gel on full-thickness excisional wounds in a db/db diabetic mouse model, with emphasis on the ability of the PA nanofiber network to regulate angiogenesis and the expression of pro-inflammatory cytokines. Here, we showed that the heparin-mimetic PA gel can support tissue neovascularization, enhance the deposition of collagen and expression of alpha-smooth muscle actin (α-SMA), and eliminate the sustained presence of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in the diabetic wound site. As the absence of neovascularization and overexpression of pro-inflammatory markers are a hallmark of diabetes and interfere with wound recovery by preventing the healing process, the heparin-mimetic PA treatment is a promising candidate for acceleration of diabetic wound healing by modulating angiogenesis and local immune response. © 2017 The Royal Society of Chemistry.
Open Access
Inter-varietal structural variation in grapevine genomes
(Wiley-Blackwell Publishing Ltd., 2016) Cardone, M. F.; D'Addabbo, P.; Alkan C.; Bergamini, C.; Catacchio, C. R.; Anaclerio, F.; Chiatante, G.; Marra, A.; Giannuzzi, G.; Perniola, R.; Ventura M.; Antonacci, D.
Grapevine (Vitis vinifera L.) is one of the world's most important crop plants, which is of large economic value for fruit and wine production. There is much interest in identifying genomic variations and their functional effects on inter-varietal, phenotypic differences. Using an approach developed for the analysis of human and mammalian genomes, which combines high-throughput sequencing, array comparative genomic hybridization, fluorescent inï¿½situ hybridization and quantitative PCR, we created an inter-varietal atlas of structural variations and single nucleotide variants (SNVs) for the grapevine genome analyzing four economically and genetically relevant table grapevine varieties. We found 4.8 million SNVs and detected 8% of the grapevine genome to be affected by genomic variations. We identified more than 700 copy number variation (CNV) regions and more than 2000 genes subjected to CNV as potential candidates for phenotypic differences between varieties
Open Access
Mammalian telomeric DNA suppresses endotoxin-induced uveitis
(American Society for Biochemistry and Molecular Biology Inc., 2010) Yagci, F. C.; Aslan, O.; Gursel, M.; Tincer, G.; Özdamar, Y.; Karatepe, K.; Akcali, K. C.; Gursel, I.
Telomeric regions of mammalian chromosomes contain suppressive TTAGGG motifs that inhibit several proinflammatory and Th1-biased immune responses. Synthetic oligodeoxynucleotides (ODN) expressing suppressive motifs can reproduce the down-regulatory activity of mammalian telomeric repeats and have proven effective in the prevention and treatment of several autoimmune and autoinflammatory diseases. Endotoxin-induced uveitis (EIU) is an established animal model of acute ocular inflammation induced by LPS administration. Augmented expression of proinflammatory cytokines/chemokines such as TNFα, IL-6, and MCP1 and bactericidal nitric oxide production mediated by LPS contribute to the development of EIU. Suppressing these mediators using agents that are devoid of undesirable systemic side effects may help prevent the development of EIU. This study demonstrates the selective down-regulatory role of suppressive ODN after (i) local or (ii) systemic treatment in EIU-induced rabbits and mice. Our results indicate that suppressive ODN down-regulate at both the transcript and protein levels of several proinflammatory cytokines and chemokines as well as nitric oxide and co-stimulatory surface marker molecules when administrated prior to, simultaneously with, or even after LPS challenge, thereby significantly reducing ocular inflammation in both rabbit and mouse eyes. These findings strongly suggest that suppressive ODN is a potent candidate for the prevention of uveitis and could be applied as a novel DNA-based immunoregulatory agent to control other autoimmune or autoinflammatory diseases. © 2010 by The American Society for Biochemistry and Molecular Biology, Inc.
Open Access
A new signaling scheme for Underwater Acoustic communications
(IEEE, 2013) Elmoslimany, A.; Zhou, M.; Duman, Tolga M.; Papandreou-Suppappola, A.
Underwater Acoustic (UWA) communications has attracted a lot of interest in recent years motivated by a wide range of applications. Different signaling solutions have been developed to date including non-coherent communications, phase coherent systems, multi-input multi-output (MIMO) solutions and multi-carrier based approaches. In this paper, we develop a novel UWA communications paradigm using biomimetic signals. In our scheme, digital information is mapped to the parameters of a class of biomimetic signal set and at the receiver an estimator to obtain the parameter values is utilized. To facilitate this, we develop analytical signal models with nonlinear instantaneous frequencies matching mammalian sound signatures in the time-frequency plane. We provide suitable receiver structures, and present decoding results using data recorded during the Kauai Acomms MURI 2011 (KAM11) UWA communications experiment. © 2013 MTS.
Open Access
A smartphone based surface plasmon resonance imaging (SPRi) platform for on-site biodetection
(Elsevier, 2017) Guner, H.; Ozgur, E.; Kokturk, G.; Celik, M.; Esen, E.; Topal, A. E.; Ayas, S.; Uludag, Y.; Elbuken, C.; Dana, A.
We demonstrate a surface plasmon resonance imaging platform integrated with a smartphone to be used in the field with high-throughput biodetection. Inexpensive and disposable SPR substrates are produced by metal coating of commercial Blu-ray discs. A compact imaging apparatus is fabricated using a 3D printer which allows taking SPR measurements from more than 20.000 individual pixels. Real-time bulk refractive index change measurements yield noise equivalent refractive index changes as low as 4.12 × 10−5 RIU which is comparable with the detection performance of commercial instruments. As a demonstration of a biological assay, we have shown capture of mouse IgG antibodies by immobilized layer of rabbit anti-mouse (RAM) IgG antibody with nanomolar level limit of detection. Our approach in miniaturization of SPR biosensing in a cost-effective manner could enable realization of portable SPR measurement systems and kits for point-of-care applications.