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https://www.readbyqxmd.com/read/28532131/investigation-into-the-anomalous-temperature-characteristics-of-ingan-double-quantum-well-blue-laser-diodes-using-numerical-simulation
#1
Han-Youl Ryu
GaN-based blue laser diodes (LDs) may exhibit anomalous temperature characteristics such as a very high characteristic temperature (T 0) or even negative T 0. In this work, temperature-dependent characteristics of GaN-based blue LDs with InGaN double quantum well (QW) structures were investigated using numerical simulations. The temperature-dependent threshold current is found to become increasingly anomalous as the thickness or doping concentration of the barrier layer between QWs increases. For a properly chosen barrier thickness and doping concentration, very high T 0 of >10,000 K can be obtained...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28532126/poly-%C3%AE-glutamic-acid-coated-lipoplexes-loaded-with-doxorubicin-for-enhancing-the-antitumor-activity-against-liver-tumors
#2
Na Qi, Bo Tang, Guang Liu, Xingsi Liang
The study was to develop poly-γ-glutamic acid (γ-PGA)-coated Doxorubicin (Dox) lipoplexes that enhance the antitumor activity against liver tumors. γ-PGA-coated lipoplexes were performed by electrostatistically attracting to the surface of cationic charge liposomes with anionic γ-PGA. With the increasing of γ-PGA concentration, the particle size of γ-PGA-coated Dox lipoplexes slightly increased, the zeta potential from positive shifted to negative, and the entrapment efficiency (EE) were no significant change...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28532117/optimization-for-extracellular-biosynthesis-of-silver-nanoparticles-by-penicillium-aculeatum-su1-and-their-antimicrobial-activity-and-cytotoxic-effect-compared-with-silver-ions
#3
Liang Ma, Wei Su, Jian-Xin Liu, Xiao-Xi Zeng, Zhi Huang, Wen Li, Zheng-Chun Liu, Jian-Xin Tang
The present study addresses an eco-friendly and energy-saving method for extracellular biosynthesis of silver nanoparticles (AgNPs) using a cell free filtrate of the fungus strain Penicillium aculeatum Su1 as a reducing agent. Parametric optimization of the biosynthesis process demonstrated different effects on the size, distribution, yield, and synthesis rate of biosynthesized AgNPs. The transmission electron microscopy (TEM) measurements demonstrated that AgNPs were spherical or approximately spherical, with a size between 4 and 55nm...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28532116/antibacterial-mechanical-and-surface-properties-of-ag-dlc-films-prepared-by-dual-pld-for-medical-applications
#4
P Písařík, M Jelínek, J Remsa, J Mikšovský, J Zemek, K Jurek, Š Kubinová, J Lukeš, J Šepitka
Silver doped diamond-like carbon layers were deposited by dual pulsed laser deposition using two KrF excimer lasers. The concentration of Ag, determined by XPS and WDS, moved from zero to ~10at%. We found that the sp(2)/sp(3) ratio, film roughness and the number of droplets (SEM and AFM) increased with increasing silver concentration. The sp(3) content measurement (XPS) was influenced by ion cluster surface sputtering and varied from 71.0% (undoped DLC) to 36.2% (for 9.3at% Ag). Transmission was measured on the scale from 200nm to 1100nm, and decreased with increasing silver content...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28532114/hypocrellin-b-and-nano-silver-loaded-polymeric-nanoparticles-enhanced-generation-of-singlet-oxygen-for-improved-photodynamic-therapy
#5
Subramanian Natesan, Venkateshwaran Krishnaswami, Chandrasekar Ponnusamy, Madi Madiyalakan, Thomas Woo, Rajaguru Palanisamy
A nanoparticulate photodynamic approach was employed with an objective to achieve enhanced production of singlet oxygen ((1)O2), for the management of posterior segment eye diseases like age related macular degeneration. The hypocrellin B (HB) loaded poly lactide-co-glycolide nanoparticle formulations were incorporated with nano silver (HBS-NPs). The optimized HBS-NPs contained 2.60±0.06mg/mL of HB and showed (i) 135.6 to 828.2nm size range, and (ii) negative zeta potential with a narrow polydispersity index...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28532112/preparations-and-doxorubicin-controlled-release-of-amino-acid-based-redox-ph-dual-responsive-nanomicelles
#6
Yuanyuan Ding, Liping Zhang, Gang Shi, Xinxin Sang, Caihua Ni
Terpolymers of poly (Lysine-co-N, N-Bis (acryloyl) cystamine-co-β-Phenethylamine) (PLBP) were synthesized in one-pot by Michael addition terpolymerization. The terpolymers self-assembled into nano-sized spherical micelles (84-123nm) with narrow distributions. The surface charge of the nanomicelles (NMs) was depended on solution's pH and showed negative values under physiological conditions (pH7.4), which was beneficial for long circulation without non-specific protein adsorption. Doxorubicin (DOX) was effectively loaded into the NMs for controlled release...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28532104/in-situ-synthesis-and-characterization-of-hydroxyapatite-natural-rubber-composites-for-biomedical-applications
#7
T A Dick, L A Dos Santos
In this work, a biomimetic synthesis reaction for the production of hydroxyapatite (HA)/natural rubber (NR) composites is presented. HA was synthesized in the presence of solubilized NR in tetrahydrofuran (THF), which permits that negatively charged domains in proteins and lipids in NR work as nucleation sites for hydroxyapatite. The mechanical and physicochemical properties of composites containing 10, 20 and 30wt% HA were studied. NR influenced HA crystallite morphology, shape and size and was able to disperse the HA particles in THF...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28532093/electrophoretic-deposition-of-organic-inorganic-composite-coatings-containing-zno-nanoparticles-exhibiting-antibacterial-properties
#8
Joanna Karbowniczek, Luis Cordero-Arias, Sannakaisa Virtanen, Superb K Misra, Eugenia Valsami-Jones, Lorena Tuchscherr, Bogdan Rutkowski, Kamil Górecki, Piotr Bała, Aleksandra Czyrska-Filemonowicz, Aldo R Boccaccini
To address one of the serious problems associated with permanent implants, namely bacterial infections, novel organic/inorganic coatings containing zinc oxide nanoparticles (nZnO) are proposed. Coatings were obtained by electrophoretic deposition (EPD) on stainless steel 316L. Different deposition conditions namely: deposition times in the range 60-300s and applied voltage in the range 5-30V as well as developing a layered coating approach were studied. Antibacterial tests against gram-positive Staphylococcus aureus and gram-negative Salmonella enteric bacteria confirmed the activity of nZnO to prevent bacterial growth...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28532092/cytocompatibility-studies-of-titania-doped-calcium-borosilicate-bioactive-glasses-in-vitro
#9
Rajkumar Samudrala, Abdul Azeem P, Vasudevarao Penugurti, Bramanandam Manavathi
The present study aims to elucidate the applications of Titania (TiO2) doped calcium borosilicate glass as a biocompatible material in regenerative orthopedic applications. In this context, we have examined the bioactivity of various concentrations of TiO2 doped glasses with the help of simulated body fluid (SBF). Cytocompatibility, cell proliferation, and protein expression studies revealed the potential candidature of TiO2 doped glasses on osteoblast cell lines (MG-63). We hypothesized that TiO2 doped calcium borosilicate glasses are most cytocompatible material for bone implants...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28532080/antibiotic-loaded-microspheres-as-antimicrobial-delivery-systems-for-medical-applications
#10
J Szczeblinska, K Fijalkowski, J Kohn, M El Fray
In this paper, we present the preparation and antibiotic loading of polymeric microspheres, composed of copolymers derived from fatty acid/amino acid components, as new polymeric platforms for antibiotic delivery systems. New polymeric materials were used to prepare microspheres with and without immobilized model antibiotics (streptomycin, chloramphenicol and amphotericin B) by a W/O/W double-emulsion/solvent evaporation method, in which chloroform and poly(vinyl alcohol) are used as the solvent and emulsifier, respectively...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28532079/nerve-growth-factor-loaded-heparinized-cationic-solid-lipid-nanoparticles-for-regulating-membrane-charge-of-induced-pluripotent-stem-cells-during-differentiation
#11
Yung-Chih Kuo, Rajendiran Rajesh
Nerve growth factor (NGF)-loaded heparinized cationic solid lipid nanoparticles (NGF-loaded HCSLNs) were developed using heparin-stearic acid conjugate, cacao butter, cholesterol, stearylamine (SA), and esterquat 1 (EQ 1). The effect of cationic lipids and lipid matrix composition on the particle size, particle structure, surface molecular composition, chemical structure, electrophoretic mobility, and zeta potential of HCSLNs was investigated. The effect of HCSLNs on the membrane charge of induced pluripotent stem cells (iPSCs) was also studied...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28532075/can-pei-microgels-become-biocompatible-upon-betainization
#12
Nurettin Sahiner, Sahin Demirci
Polyethylene imine (PEI) microgels prepared via micro emulsion polymerization technique were treated with 1,3-propane sultone to obtained betainized PEI (b-PEI) microgels. The betainization reaction generated zwitterions on PEI microgel that are positive charges from quarternized amine groups of PEI, and the newly formed negative charges from SO3(-) groups from the modifying agent, 1,3-propane sultone offered interesting properties. The smaller size of b-PEI microgels that are obtained by simple filtration were increased with betainization from 512±14 to 1114±86nm...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28532073/fabrication-of-vinyl-organosilicon-poly-n-n-4-5-dihydroxy-1-2-phenylene-bis-methylene-bisacrylamide-core-shell-antibacterial-agent
#13
Zhijia Zhang, Xiaole Zhao, Yingchun Su, Defeng Xing, Xiaojun Han
We demonstrate that antibacterial agent N, N'-[(4, 5-dihydroxy-1, 2-phenylene)bis(methylene)]bisacrylamide (OHABA) can be assembled on the surface of vinyl organosilicon nanospheres (VOSNs) by atom transfer radical polymerization (ATRP). Chemically cross-linked vinyl organosilicon cores were facilely fabricated by sol-gel method as support, which densely grafted poly-OHABA (POHABA) as shells. Antibacterial assessment test results revealed that POHABA-based core@shell structure displayed high antibacterial performance, long-term stability, and kept broad-spectrum antibacterial effect of against Gram-negative and Gram-positive bacteria...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28532035/honey-pva-hybrid-wound-dressings-with-controlled-release-of-antibiotics-structural-physico-mechanical-and-in-vitro-biomedical-studies
#14
Javad Tavakoli, Youhong Tang
Hydrogel/honey hybrids manifest an attractive design with an exclusive therapeutic property that promotes wound healing process. The greater the concentration of honey within the formulation, the better the biomedical properties that will be achieved. However, an increase in the percentage of honey can negatively affect the physico-chemical and mechanical properties of hybrid hydrogels. The need exists, therefore, to prepare wound dressings that contain high honey density with optimal biomedical, mechanical and physicochemical properties...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28532030/tetracycline-hydrochloride-loaded-electrospun-nanofibers-mats-based-on-pva-and-chitosan-for-wound-dressing
#15
Alex Carvalho Alavarse, Fernanda Waitman de Oliveira Silva, Jandir Telleria Colque, Viviam Moura da Silva, Tatiane Prieto, Everaldo Carlos Venancio, Jean-Jacques Bonvent
Fibrous mats built from biopolymer have been extensively explored for tissue engineering due mainly to their mimic structure to the extracellular matrix. The incorporation of drug in such scaffolds represents a growing interest for control drug delivery system in order to promote the tissue repair. In the present work, we present an experimental investigation of morphological, thermal, mechanical, drug release, antibacterial and cytotoxicity properties of electrospun PVA/Chitosan and PVA/Chitosan/Tetracycline hydrochloride (TCH) mats for wound dressing...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28531996/poly-epsilon-caprolactone-nanoparticles-enhance-ursolic-acid-in-vivo-efficacy-against-trypanosoma-cruzi-infection
#16
Juliana Palma Abriata, Josimar O Eloy, Thalita Bachelli Riul, Patricia Mazureki Campos, Marcelo Dias Baruffi, Juliana Maldonado Marchetti
Despite affecting millions of people worldwide, Chagas disease is still neglected by the academia and industry and the therapeutic option available, benznidazole, presents limited efficacy and side effects. Within this context, ursolic acid may serve as an option for treatment, however has low bioavailability, which can be enhanced through the encapsulation in polymeric nanoparticles. Therefore, herein we developed ursolic acid-loaded nanoparticles with poly-ε-caprolactone by the nanoprecipitation method and characterized them for particle size, zeta potential, polydispersity, encapsulation efficiency, morphology by scanning electron microscopy and thermal behavior by differential scanning calorimetry...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28531977/antibiofilm-effect-of-supramolecularly-templated-mesoporous-silica-coatings
#17
Magdalena Pezzoni, Paolo N Catalano, Ramón A Pizarro, Martín F Desimone, Galo J A A Soler-Illia, Martín G Bellino, Cristina S Costa
Bacteria attached to solid surfaces and encased in a self-synthesized matrix, so-called biofilms, are highly difficult to eradicate and present negative impact on industry and human health. The ability of supramolecularly templated mesoporous silica coatings to inhibit biofilm formation in Pseudomonas aeruginosa is shown here. Assays employing submerged and air-liquid interface biofilms demonstrated that mesoporous coatings with tuned pore size significantly reduce the number of attached bacteria and matrix production...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28531969/biogeographical-factors-affecting-the-distribution-of-stream-salamanders-on-the-cumberland-plateau-usa
#18
P R Gould, K K Cecala, S S Drukker, B A McKenzie, C Van de Ven
Geophysical and climate conditions play an important role in the distribution of organisms at both fine and broad scales. Headwater streams integrate changes at broad geographical scales and serve as important regions of nutrient processing and support high biodiversity. Stream salamanders are important members of headwater aquatic communities as both predators and prey. Combined with their biphasic life histories and physiological requirements, stream amphibians may serve as indicators for headwater stream conditions...
May 18, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28531965/does-arbuscular-mycorrhizal-fungus-affect-cadmium-uptake-and-chemical-forms-in-rice-at-different-growth-stages
#19
Na Luo, Xing Li, Ao Yu Chen, Li Jun Zhang, Hai Ming Zhao, Lei Xiang, Quan Ying Cai, Ce Hui Mo, Ming Hung Wong, Hui Li
Effects of the arbuscular mycorrhizal fungus (AMF) - Rhizophagus intraradices (a mix of root pieces, mycelium pieces and spores) on the temporal variation of Cd uptake and chemical forms in rice at four growth periods (tillering, jointing, flowering, and ripening stages) were investigated in soil added with 0, 2 and 10mgCdkg(-1). Results showed that the interactions amongst rice growth stages, soil Cd concentrations and mycorrhizal inoculation had significant effects (P˂0.001) on root biomass, straw and root Cd concentrations, and straw Cd chemical forms in rice...
May 18, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28531961/challenges-in-photocatalytic-reduction-of-nitrate-as-a-water-treatment-technology
#20
Heather O'Neal Tugaoen, Sergi Garcia-Segura, Kiril Hristovski, Paul Westerhoff
Management of ubiquitous nitrate contamination in drinking water sources is a major engineering challenge due to its negative impacts from eutrophication to immediate risk to human health. Several water treatment technologies exist to manage nitrate pollution in water sources. However, the most widely used technologies are phase separation treatments. In this context, nanoscale photocatalysis emerges as a highly promising transformative technology capable of reducing nitrate to innocuous nitrogen with noticeable selectivity...
May 17, 2017: Science of the Total Environment
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