Cytocompatibility of preadipocytes in diacrylated polyethylene glycol crosslinked with various UV light photoinitiating systems

2003 ◽  
Author(s):  
P.N. Patel ◽  
C.W.Jr. Patrick
Keyword(s):  
Polyethylene Glycol ◽  
Uv Light

Fabrication of PEG Hydrogel and PDMS Microstructures by a Simple UV Curing Process for Nanobio-Chip Applications

2014 ◽  
Vol 941-944 ◽  
pp. 404-410 ◽  
Author(s):  
Young Ho Kim ◽  
Jeong Woo Sohn ◽  
Youngjae Woo ◽  
Joo Hyun Hong ◽  
Juyoung Park
Keyword(s):  
Polyethylene Glycol ◽  
Uv Irradiation ◽  
Large Scale ◽  
Uv Light ◽  
Single Step ◽  
Polydimethyl Siloxane ◽  
Polyethylene Glycol Diacrylate ◽  
Glycol Diacrylate ◽  
Metal Mask ◽  
Glass Chip

Polyethylene glycol (PEG) hydrogel microstructures with various shapes and sizes on a glass chip were prepared by a simple and rapid ultraviolet (UV) irradiation method using a metal mask. Photocurable PEG solution prepared by mixing 95 wt.% polyethylene glycol diacrylate and 5 wt.% 2-hydroxy-2-methylpropiophenone as a photo-initiator was injected to the gap between bottom and upper glasses in a simply assembled glass chip. After a metal mask with line-and-space or complex patterns was placed on the glass chip, UV light from a spot UV irradiation device was exposed to the glass chip through the metal mask for 7 seconds at UV intensity of 26 mW/cm2. Then the PEG hydrogel micropatterns on the glass chip were obtained after removing unreacted PEG solution by air blowing. To prepare more rigid microstructure, the prepared PEG micropatterned chip was exposed under UV light for 20 seconds. Then the PEG hydrogel micropattern chip was fabricated by a simple and rapid procedure. Micropattern transferring was performed from the PEG hydrogel chip to polydimethyl siloxane (PDMS) replica by a solution casting. The prepared micropatterned PDMS replicas showed similar shape and size of microstructures compared to that of the corresponded PEG hydrogel chip. Thus the PEG hydrogel microstructures on a glass chip could be used as a mold to fabricate micropattern PDMS chips for nanobio-chip applications. Furthermore, the present method provides large scale chip fabrication, more than 4 cm-length and 4 cm-width in a single step, not only PEG hydrogel chips but also PDMS chips.

The Photoelectrochemical Characteration of Porous Titania Dioxide Thin Films Prepared by PEG-Assisted Sol-Gel Method

2009 ◽  
Vol 79-82 ◽  
pp. 943-946
Author(s):  
Ai Ping Wang ◽  
Yan Sheng Yin ◽  
Hong Feng Wang ◽  
Zhi Bin Zhu ◽  
Ming Hui He
Keyword(s):  
Thin Films ◽  
Cyclic Voltammetry ◽  
Polyethylene Glycol ◽  
Uv Light ◽  
Sol Gel ◽  
Tio2 Thin Films ◽  
Photoelectrochemical Activity ◽  
Gel Method ◽  
Sol Gel Method ◽  
Porous Titania

Nanocrystalline titania porous films were prepared on ITO and glass substrates by polyethylene glycol（PEG）-assisted sol-gel method using Ti(C4H9COO)4 as precursor, ethanol as solvent and NH(C2H2OH)2 as chelating agent and PEG 2000as a template. When the amount of polyethylene glycol is within the range of 0～2. 0g/L ,. The characteristics and microstructure of films as well as the chemical and physical changes taken place during so-gel and heat treatments were analyzed by XRD, SEM and Emission spectra. The Cyclic voltammetry which measurements the films by illumination with a high pressure mercury lamp are employed to analyze photoelectrochemical property the porous titania thin films. The effects of precursor concentration and PEG 2000 contention the characteristic of films were discussed. The Cyclic voltammetry experiment under UV light irradiation indicated that the pores in the TiO2 thin films enhanced its photoelectrochemical activity; the size of the pores thin films obviously affected the photo-current exchanged rate of titania films.

scholarly journals Acoustic focusing of beads and cells in hydrogel droplets

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anna Fornell ◽  
Hannah Pohlit ◽  
Qian Shi ◽  
Maria Tenje
Keyword(s):  
Polyethylene Glycol ◽  
Uv Light ◽  
Precursor Solution ◽  
Microfluidic System ◽  
Nodal Line ◽  
Droplet Microfluidics ◽  
Acoustic Standing Wave ◽  
Centre Line ◽  
Half Wavelength ◽  
Acoustic Focusing

AbstractThe generation of hydrogel droplets using droplet microfluidics has emerged as a powerful tool with many applications in biology and medicine. Here, a microfluidic system to control the position of particles (beads or astrocyte cells) in hydrogel droplets using bulk acoustic standing waves is presented. The chip consisted of a droplet generator and a 380 µm wide acoustic focusing channel. Droplets comprising hydrogel precursor solution (polyethylene glycol tetraacrylate or a combination of polyethylene glycol tetraacrylate and gelatine methacrylate), photoinitiator and particles were generated. The droplets passed along the acoustic focusing channel where a half wavelength acoustic standing wave field was generated, and the particles were focused to the centre line of the droplets (i.e. the pressure nodal line) by the acoustic force. The droplets were cross-linked by exposure to UV-light, freezing the particles in their positions. With the acoustics applied, 89 ± 19% of the particles (polystyrene beads, 10 µm diameter) were positioned in an area ± 10% from the centre line. As proof-of-principle for biological particles, astrocytes were focused in hydrogel droplets using the same principle. The viability of the astrocytes after 7 days in culture was 72 ± 22% when exposed to the acoustic focusing compared with 70 ± 19% for samples not exposed to the acoustic focusing. This technology provides a platform to control the spatial position of bioparticles in hydrogel droplets, and opens up for the generation of more complex biological hydrogel structures.

scholarly journals THE EFFECT OF SOL-GEL TEMPERATURE AND SOLVENT POLYETHYLENE GLYCOL (PEG) IN ZnO- TiO2 PHOTOCATALYST ACT AS DEGRADER OF TEXTILE DYEING LIQUID WASTE

2016 ◽  
Vol 10 (2) ◽  
pp. 149
Author(s):  
Tanti Haryati ◽  
Novita Andarini ◽  
Siti Mardhiyah
Keyword(s):  
Crystal Structure ◽  
Photocatalytic Activity ◽  
Polyethylene Glycol ◽  
Uv Light ◽  
Sol Gel ◽  
Liquid Waste ◽  
Synthesis Temperature ◽  
Tio2 Photocatalyst ◽  
Textile Dyeing ◽  
Gel Temperature

<p>The use of TiO<sub>2</sub>  powder  as photocatalyst still provides some disadvantages such as the difficulties in regenerate ion, the low adsorption and turbulence . These problems can be overcomed by providing the photocatalyst as a composite of ZnO-TiO2. This research aims to  investigate  the  effect  of  composition  of  solvent  and  temperatureof  synthesis  on  the quality  and  photocatalytic  activity  of  ZnO-TiO2  which  was  prepared  by  sol-gel  method. The  photocatalytic  activity  was  determined  by  applying  the  composite  in  degradation  of Procion  Red  MX-8B  under  irradition  of  UV  light  for  24  hours.  The  procion  red concentration after degradation was determined by UV-Vis spectrophotometer. Meanwhile the effect of synt hesis temperature on crystal structure  of composite  was studied by XRD. The results show that the composite which was prepared by PEG 1500 at 1:4 of moles ratio and at 70  °C of  synthesis temperature has  highest degradation  percentage,  i.e. 55.375 % and photocataltic activity of 3.561 x 10<sup>-7</sup>mg/cm<sup>2</sup>s.</p>

scholarly journals THE EFFECT OF SOL-GEL TEMPERATURE AND SOLVENT POLYETHYLENE GLYCOL (PEG) IN ZnO- TiO2 PHOTOCATALYST ACT AS DEGRADER OF TEXTILE DYEING LIQUID WASTE

2016 ◽  
Vol 10 (2) ◽  
pp. 149
Author(s):  
Tanti Haryati ◽  
Novita Andarini ◽  
Siti Mardhiyah
Keyword(s):  
Crystal Structure ◽  
Photocatalytic Activity ◽  
Polyethylene Glycol ◽  
Uv Light ◽  
Sol Gel ◽  
Liquid Waste ◽  
Synthesis Temperature ◽  
Tio2 Photocatalyst ◽  
Textile Dyeing ◽  
Gel Temperature

<p>The use of TiO<sub>2</sub>  powder  as photocatalyst still provides some disadvantages such as the difficulties in regenerate ion, the low adsorption and turbulence . These problems can be overcomed by providing the photocatalyst as a composite of ZnO-TiO2. This research aims to  investigate  the  effect  of  composition  of  solvent  and  temperatureof  synthesis  on  the quality  and  photocatalytic  activity  of  ZnO-TiO2  which  was  prepared  by  sol-gel  method. The  photocatalytic  activity  was  determined  by  applying  the  composite  in  degradation  of Procion  Red  MX-8B  under  irradition  of  UV  light  for  24  hours.  The  procion  red concentration after degradation was determined by UV-Vis spectrophotometer. Meanwhile the effect of synt hesis temperature on crystal structure  of composite  was studied by XRD. The results show that the composite which was prepared by PEG 1500 at 1:4 of moles ratio and at 70  °C of  synthesis temperature has  highest degradation  percentage,  i.e. 55.375 % and photocataltic activity of 3.561 x 10<sup>-7</sup>mg/cm<sup>2</sup>s.</p>

scholarly journals Removal of Nonylphenol Polyethylene Glycol (NPEG) with Au-TiO2 Catalysts: Kinetic and Initial Transformation Path

Catalysts ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1205
Author(s):  
Claudia Aguilar ◽  
Mayra Garcia ◽  
Carlos Montalvo ◽  
Francisco Anguebes ◽  
Edgar Moctezuma ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Polyethylene Glycol ◽  
Diffuse Reflectance ◽  
Uv Light ◽  
Gold Particles ◽  
Visible Light Range ◽  
Marquardt Algorithm ◽  
Gold Precursor ◽  
Initial Transformation ◽  
Scanning Electron

The purpose of this study was to evaluate the efficiency of the Au-TiO2 catalyst in the degradation of nonylphenol polyethylene glycol (NPEG). In the first part of the study, the catalyst was synthesized and characterized. Initially, the catalyst (TiO2 Degussa P-25) was doped with gold precursor salts (HAuCl4) at different concentrations (5, 10, and 15%) and the photodeposition method with UV light. It was determined by diffuse reflectance (DF) and scanning electron microscopy (SEM) that the photodeposition method was effective for the inclusion of gold particles on the surface. The catalyst band gap showed a reduction to 2.9 e.v (compared to TiO2 Degussa P-25), and it was observed that the gold-doped catalyst showed absorption in the visible light range 500 to 600 nm. The percentage of deposited gold was determined by energy dispersive spectroscopy (EDS). In the second part of the study, various NPEG degradation experiments were performed; with the catalyst that showed the best conversion percentages of NPEG, the experimental data were analyzed using UV-Vis spectrophotometry and TOC (total organic carbon). With these results, a carbon-based mass balance and reaction kinetics were generated using the Langmuir–Hinshelwood (L–H) heterogeneous catalysis model. For the estimation of the kinetic constants, the non-linear regression of the Levenger–Marquardt algorithm was used. With these results, kinetic models of the degradation of the molecule and the generation and consumption of organic intermediate products (OIPs) were generated.

Electron microscopy of keratinocytes cultured on a collagen substrate used as an allograft for the treatment of chronic wounds

1992 ◽  
Vol 50 (2) ◽  
pp. 1104-1105
Author(s):  
Debby A. Jennings ◽  
Michael J. Morykwas ◽  
Louis C. Argenta
Keyword(s):  
Electron Microscopy ◽  
Cell Suspension ◽  
Single Cell ◽  
Chronic Wounds ◽  
Mechanical Stability ◽  
Uv Light ◽  
Type I ◽  
Single Cell Suspension ◽  
Collagen Substrate ◽  
Dermal Collagen

Grafts of cultured allogenic or autogenic keratlnocytes have proven to be an effective treatment of chronic wounds and burns. This study utilized a collagen substrate for keratinocyte and fibroblast attachment. The substrate provided mechanical stability and augmented graft manipulation onto the wound bed. Graft integrity was confirmed by light and transmission electron microscopy.Bovine Type I dermal collagen sheets (100 μm thick) were crosslinked with 254 nm UV light (13.5 Joules/cm2) to improve mechanical properties and reduce degradation. A single cell suspension of third passage neonatal foreskin fibroblasts were plated onto the collagen. Five days later, a single cell suspension of first passage neonatal foreskin keratinocytes were plated on the opposite side of the collagen. The grafts were cultured for one month.The grafts were fixed in phosphate buffered 4% formaldehyde/1% glutaraldehyde for 24 hours. Graft pieces were then washed in 0.13 M phosphate buffer, post-fixed in 1% osmium tetroxide, dehydrated, and embedded in Polybed 812.

Immunocytochemical detection of hepatic carbohydrate metabolic enzymes: Improved resolution with polyethylene glycol embedding and visio-bond semithin sections

1992 ◽  
Vol 50 (1) ◽  
pp. 792-793
Author(s):  
Kuixiong Gao ◽  
Randal E. Morris ◽  
Bruce F. Giffin ◽  
Robert R. Cardell
Keyword(s):  
Polyethylene Glycol ◽  
Glycogen Phosphorylase ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Glycogen Synthase ◽  
Metabolic Enzymes ◽  
Silver Stain ◽  
Accurate Localization ◽  
Immunocytochemical Detection ◽  
Semithin Sections ◽  
Parenchymal Cells

Several enzymes are involved in the regulation of anabolic and catabolic pathways of carbohydrate metabolism in liver parenchymal cells. The lobular distribution of glycogen synthase (GS), phosphoenolpyruvate carboxykinase (PEPCK) and glycogen phosphorylase (GP) was studied by immunocytochemistry using cryosections of normal fed and fasted rat liver. Since sections of tissue embedded in polyethylene glycol (PEG) show good morphological preservation and increased detectability for immunocytochemical localization of antigenic sites, and semithin sections of Visio-Bond (VB) embedded tissue provide higher resolution of cellular structure, we applied these techniques and immunogold-silver stain (IGSS) for a more accurate localization of hepatic carbohydrate metabolic enzymes.

Directional observation on lipid of male nectary of Lindera megaphylla hemsl. by the rapid embedding method with polyethylene glycol (PEG)

1990 ◽  
Vol 48 (3) ◽  
pp. 718-719
Author(s):  
Dai Dalin ◽  
Guo Jianmin
Keyword(s):  
Electron Microscope ◽  
Polyethylene Glycol ◽  
Chemical Reaction ◽  
Traditional Method ◽  
Osmium Tetroxide ◽  
Unsaturated Lipid ◽  
Embedding Method ◽  
Long Period ◽  
New Methods

Lipid cytochemistry has not yet advanced far at the EM level. A major problem has been the loss of lipid during dehydration and embedding. Although the adoption of glutaraldehyde and osmium tetroxide accelerate the chemical reaction of lipid and osmium tetroxide can react on the double bouds of unsaturated lipid to from the osmium black, osmium tetroxide can be reduced in saturated lipid and subsequently some of unsaturated lipid are lost during dehydration. In order to reduce the loss of lipid by traditional method, some researchers adopted a few new methods, such as the change of embedding procedure and the adoption of new embedding media, to solve the problem. In a sense, these new methods are effective. They, however, usually require a long period of preparation. In this paper, we do research on the fiora nectary strucure of lauraceae by the rapid-embedding method wwith PEG under electron microscope and attempt to find a better method to solve the problem mentioned above.

A photoelectron microscope study of surfaces

1989 ◽  
Vol 47 ◽  
pp. 10-11
Author(s):  
W. Engel ◽  
M. Kordesch ◽  
A. M. Bradshaw ◽  
E. Zeitler
Keyword(s):  
Electron Microscopy ◽  
High Pressure ◽  
Field Strength ◽  
Uv Light ◽  
Physical Property ◽  
Photon Flux ◽  
Mercury Lamp ◽  
Object Surface ◽  
The Sixties ◽  
Physical Features

Photoelectron microscopy is as old as electron microscopy itself. Electrons liberated from the object surface by photons are utilized to form an image that is a map of the object's emissivity. This physical property is a function of many parameters, some depending on the physical features of the objects and others on the conditions of the instrument rendering the image.The electron-optical situation is tricky, since the lateral resolution increases with the electric field strength at the object's surface. This, in turn, leads to small distances between the electrodes, restricting the photon flux that should be high for the sake of resolution.The electron-optical development came to fruition in the sixties. Figure 1a shows a typical photoelectron image of a polycrystalline tantalum sample irradiated by the UV light of a high-pressure mercury lamp.

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