DERMATOLOGIC SURGERY, Issue 12p2 2004
Snehal P. Amin
Background. Polyacrylamide gels, containing a hydrogel composed of polyacrylamide and water, are used for soft tissue augmentation and contour correction. There are no reports of significant complications after injection of this material into the face. Objective. We report an inflammatory reaction after injection of polyacrylamide gels for zygomatic facial augmentation. Methods. A retrospective chart review of single case is presented. Results. An inflammatory reaction at the sites of polyacrylamide gels injection was noted at 1 month after initial injection. Despite two ensuing courses of broad-spectrum antibiotics, the patient presented to us with persistent draining nodules. Intralesional steroid injections resulted in prompt resolution and no recurrence. Conclusion. Inflammatory reactions have been noted in patients receiving polyacrylamide gels for breast augmentation. Facial polyacrylamide gels injections may also be associated with an inflammatory reaction that responds to intralesional steroids. With increasing availability of a variety of soft tissue fillers, dermatologists should be aware of this delayed complication from polyacrylamide gels. [source]

Biomorphic Silicon Carbide Coated with an Electrodeposition of Nanostructured Hydroxyapatite/Collagen as Biomimetic Bone Filler and Scaffold,

ADVANCED ENGINEERING MATERIALS, Issue 8 2010
M. Lelli
Abstract The paper describes the method of preparation and chemical/physical characterization of a new biomaterial to be used as a bone substitute and bone-tissue engineering scaffold, which synergistically joins a porous bio-inspired morphology and the mechanical properties of biomorphic silicon carbide (BioSiC) with the surface bioactivity of a nanostructured hydroxyapatite/collagen biomimetic coating. FT-IR spectroscopy and XRD techniques are utilized to determine the chemical coating's composition. The morphology and size of the inorganic and protein components are investigated by TEM. The characteristic morphology of BioSiC channels and pores, which differ as a function of the transversal or longitudinal cross-section and with etching time, are investigated by SEM. Natural wood transformed into BioSiC acts as a cathode in an electrochemically assisted process that produces on its surface a biomimetic coating of hydroxyapatite nanocrystals and reconstituted type I collagen fibrils, producing an innovative apatite/collagen biomimetic porous bone filler and scaffold for tissue engineering. [source]

Tailoring Cell Behavior on Polymers by the Incorporation of Titanium Doped Phosphate Glass Filler,

ADVANCED ENGINEERING MATERIALS, Issue 7 2010
Wojciech Chrzanowski
Abstract Understanding tissue response to materials, to enable modulation and guided tissue regeneration is one of the main challenges in biomaterials science. Nowadays polymers, glasses, and metals dominate as biomaterials. Often native properties of those materials are not sufficient and there is a need to combine them, so as to modify and adjust their properties to the application. The primary aim of this study was to improve cell response to polymer (PLDL) using phosphate glass as filler (titanium doped phosphate glass). As a control ,-tricalcium phosphate (TCP) filler was used. Various concentrations of the filler were used (10,40 vol%). Wetting behavior, , -potentials, mechanical and thermal properties, and human cells response to the materials were evaluated. Results showed that with increase in glass filler loading wettability improved, , -potentials dropped, and increase in stiffness of materials was observed. Importantly cell culture experiments showed more developed and well spread cells on the samples with glass content up to 20 vol%. Cells responded much more positively to the glass filled samples than to TCP filled. However, expression of osteocalcin and osteopontin, proteins that indicate formation of the mineralized structures was positive for all the samples including pure PLDL. It was concluded that due to improved wetting behavior, lower , -potentials, and specific chemistry of the glass filler it was possible to alter cells response, improve bioactivity of the polymer, and vary mechanical properties. [source]

High Breakdown Field Dielectric Elastomer Actuators Using Encapsulated Polyaniline as High Dielectric Constant Filler

ADVANCED FUNCTIONAL MATERIALS, Issue 19 2010
Martin Molberg
Abstract A novel method allowing rapid production of reliable composites with increased dielectric constant and high dielectric strength for dielectric elastomer actuators (DEA) is reported. The promising approach using composites of conductive particles and insulating polymers generally suffers from low breakdown fields when applied to DEA devices. The present publication shows how to overcome this deficiency by using conductive polyaniline (PANI) particles encapsulated into an insulating polymer shell prior to dispersion. PANI particles are encapsulated using miniemulsion polymerization (MP) of divinylbenzene (DVB). The encapsulation process is scaled up to approximately 20 g particles per batch. The resulting particles are used as high dielectric constant (,,) fillers. Composites in a polydimethylsiloxane (PDMS) matrix are prepared and the resulting films characterized by dielectric spectroscopy and tensile tests, and evaluated in electromechanical actuators. The composite films show a more than threefold increase in ,,, breakdown field strengths above 50 V ,m,1, and increased strain at break. These novel materials allow tuning the actuation strain or stress output and have potential as materials for energy harvesting. [source]

Polybenzimidazole-Based Membranes as a Real Alternative to Nafion for Fuel Cells Operating at Low Temperature,

ADVANCED MATERIALS, Issue 7 2008
Piercarlo Mustarelli
Filler up! Composite proton-conducting membranes, based on polybenzimidazole (PBI) and imidazole-derivatized silica are presented. The addition of even small amounts (,10 wt %) of filler causes an outstanding improvement in the permanent proton conductivity by a factor <103. The preparation of PBI composite membranes with basic functionalities is a promising way to make possible their use in PEMFCs operating around 120,°C, that is, the temperature required for automotive applications. [source]

Acrylic Bone Cements Modified With Bioactive Filler

MACROMOLECULAR SYMPOSIA, Issue 1 2009
Carlos Federico Jasso-Gastinel
Abstract Bioactive cuttlebone Sepia officinalis particles that contain collagen were used to fill poly (methyl methacrylate- co -styrene) bone cements, varying size and concentration of filler particles. Cuttlebone was characterized by X-ray diffraction and plasma atomic emission spectrophotometer. Maximum reaction temperature and cement setting time were determined for composites and reference (copolymer without filler), along with NMR determination of residual monomer concentration. Mechanical properties characterization included stress-strain, bending, compression, fracture toughness and storage modulus tests. Mechanical results for composites filled with 10 and 30% weight of cuttlebone, complied with norm requirements which opens the possibility for using cuttlebone particles as bioactive filler. [source]

ChemInform Abstract: SnxPt4SnySb12-y: A Skutterudite with Covalently Bonded Filler.

CHEMINFORM, Issue 2 2009
Y. Liang
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Effect of NaCl filler on ferroelectric phase and polaron configurations of PVDF films

CRYSTAL RESEARCH AND TECHNOLOGY, Issue 4 2007
I. S. ElashmawiArticle first published online: 8 MAR 200
Abstract Polyvinyldene fluoride (PVDF) films filled with NaCl of mass fraction range 1 , W , 6 % were prepared by casting technique. Their crystalline structure, thermal, optical properties and Electron spin resonance (ESR) were examined. X-ray diffraction (XRD) and differential thermal analysis (DTA) measurements indicated a maximum ferroelectric ,-phase increment at 4%. DTA was used to identify the phase transition temperatures, the order of reaction and the activation energy of melting. The UV-Visible optical absorption implied a minimum value of the estimated optical energy gap at W = 4%. ESR spectra contained a Lorentizian signal exhibiting a minimum value of the symmetry factor at W = 4%. The energy levels of the optical gap boundaries were though to contribute to ESR transitions. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

In Vitro Resistance to Degradation of Hyaluronic Acid Dermal Fillers by Ovine Testicular Hyaluronidase

DERMATOLOGIC SURGERY, Issue 2010
DEREK JONES MD
BACKGROUND Although adverse events are uncommon with hyaluronic acid (HA) fillers, the use of hyaluronidase permits the reversal of treatment complications or overcorrection. OBJECTIVE This study sought to determine an in vitro dose-response relationship between ovine testicular hyaluronidase (OTH) and three HA dermal fillers (24-mg/mL smooth gel, 20-mg/mL particulate gel, and 5.5-mg/mL particulate gel with 0.3% lidocaine). METHODS AND MATERIALS The dose response of each was measured after incubation for 30 minutes in concentrations ranging between 5 and 40 U of OTH. Timed responses for the 24-mg/mL and 20-mg/mL HA fillers were obtained after incubation with 20 U of OTH for 15 to 120 minutes. RESULTS After all dose responses and timed-interval tests, the 24-mg/mL HA smooth gel filler exhibited more resistance against in vitro enzymatic degradation to OTH than the 20- and 5.5-mg/mL HA particulate gels. CONCLUSION This resistance to degradation in vitro may be attributed to the higher HA content of the 24-mg/mL HA smooth gel, the degree of crosslinking, and the cohesive property of the gel filler. This study was funded by a grant from Allergan, Inc., Santa Barbara, CA. Derek Jones, MD, is a consultant, investigator, advisory board member, and speaker for Allergan, Inc. He received no compensation for this study. Drs. Tezel and Borrell are employed by Allergan, Inc., Santa Barbara, CA. Editorial assistance was provided by Health Learning Systems, a part of CommonHealth, Parsippany, NJ. [source]

Viability of Preadipocytes In Vitro: The Influence of Local Anesthetics and pH

DERMATOLOGIC SURGERY, Issue 8 2009
MAIKE KECK MD
BACKGROUND Autogenous fat transfer with lipoinjection for soft tissue augmentation is a commonly used surgical technique. Abundant donor tissue availability and relative ease of harvesting have made autologous fat an attractive soft tissue filler. The overall reliability of this technique is often disputed, and different authors describe different results after autologous fat transplantation despite using similar techniques. In this study, we examined the influence of different local anesthetics commonly used in fat harvest and the pH of the anesthetic solution on the viability of harvested preadipocytes. METHODS AND MATERIALS Preadipocytes were incubated with 1% lidocaine, 1% articaine plus epinephrine 1:200,000, 0.75% ropivacaine, and 1% prilocaine or our standardized tumescent solution (1 L of 0.9% sodium chloride solution plus 25 mL of 1% articaine plus epinephrine 1:200,000 plus 25 mL of bicarbonate) for 30 minutes. Additionally, we incubated cells with the local anesthetics as described above but diluted 1:2 with phosphate buffered saline (pH 7.4). Viability was measured using trypan blue dying as well as propidium iodine staining and fluorescence-activated cell sorting analysis. RESULTS There are significant differences in the viability of preadipocytes under the influence of various local anesthetics. DISCUSSION Our data could partially explain the varying results after autogenous fat transfer. [source]

Tissue Integration of Polyacrylamide Hydrogel: An Experimental Study of Periurethral, Perivesical, and Mammary Gland Tissue in the Pig

DERMATOLOGIC SURGERY, Issue 2008
DMSC, LISE H. CHRISTENSEN MD
BACKGROUND Polyacrylamide hydrogel (PAAG) is a nondegradable water-based polymer with high viscoelasticity. The gel is used as a tissue filler, the only risk being prolonged infection with anaerobic, contaminating microorganisms if not treated early with broad-spectrum antibiotics. OBJECTIVE With silicone gel as reference, PAAG tissue integration and migration was studied in a longitudinal study of the pig. MATERIALS AND METHODS Forty-one pigs were used. PAAG and silicone gel were injected into mammary tissue, and PAAG was injected into urethral or bladder wall or the anal canal. Tissues and regional lymph nodes were examined at 1, 1 1/2, 3, 3 1/2, 6, 12, and 14 months, and other lymph nodes and organs were examined at 1, 6, 12, and 14 months. RESULTS PAAG was invaded by macrophages and giant cells that were gradually replaced by a network of fibrous tissue. Silicone gel was seen inside these cells or as large vacuoles, surrounded by a fibrous capsule. Regional lymph nodes contained PAAG only at 1 1/2 months and silicone gel at 12 months. CONCLUSION PAAG is a stable, viscoelastic bulking agent, which unlike silicone gel is slowly integrated within its host tissue via a thin fibrous network. Long-term risk of fibrosis and migration is minimal. [source]

Radiographic and Computed Tomographic Studies of Calcium Hydroxylapatite for Treatment of HIV,Associated Facial Lipoatrophy and Correction of Nasolabial Folds

DERMATOLOGIC SURGERY, Issue 2008
ALASTAIR CARRUTHERS MD
OBJECTIVES This study sought to assess the radiographic appearance produced by calcium hydroxylapatite soft tissue filler (CaHA; Radiesse, BioForm Medical Inc.) following augmentation to correct the nasolabial folds or facial wasting associated with human immunodeficiency virus lipoatrophy. METHODS A total of 58 patients, with either lipoatrophy or pronounced nasolabial folds, were treated with CaHA. Radiographic (X-ray) and computed tomographic (CT) imaging studies were conducted pre- and posttreatment in most patients; the images were sent to an independent laboratory to be analyzed by two evaluators who were board-certified radiologists and blinded to study purpose, product, and patient condition. RESULTS While results for X-ray evaluation showed inconsistencies in visualization of CaHA, CT scans showed consistent visualization in nearly all cases in patients who were imaged immediately after treatment. In addition, the results indicated no obscuration of underlying structures by CaHA and no evidence of CaHA migration. CONCLUSIONS Earlier clinical trials established CaHA as a safe and effective soft tissue filler. This CaHA study shows no overt radiographic safety concerns. CaHA is unlikely to be confused with conventional abnormal and adverse radiographic findings. The product is not always visible on X-ray. Although usually visible on CT scans, its appearance is distinct from surrounding bony structures and does not interfere with normal analysis. In addition, the product does not obscure underlying structures on CT scans. [source]

A Randomized, Bilateral, Prospective Comparison of Calcium Hydroxylapatite Microspheres versus Human-Based Collagen for the Correction of Nasolabial Folds

DERMATOLOGIC SURGERY, Issue 2007
STACY SMITH MD
BACKGROUND Current soft tissue fillers are a compromise between ease of use, duration of correction, reactivity, and cost. A product utilizing calcium hydroxylapatite (CaHA) is currently being used as a soft tissue filler. OBJECTIVE The objective was to compare the efficacy and safety of CaHA microspheres versus human-based collagen for the correction of nasolabial folds. MATERIALS AND METHODS Four centers enrolled 117 subjects with moderate to deep nasolabial folds. Subjects received CaHA on one side of the face and human collagen on the other. Up to two touch-ups were allowed. A blinded panel of experts evaluated subject photographs from initial and follow-up visits. RESULTS Seventy-nine percent of subjects had superior improvement on the CaHA side through 6 months (p<.0001). For optimal correction, significantly less volume and fewer injections were needed for CaHA than for collagen (p<.0001). Adverse event rates were comparable, with some increase in bruising and edema for CaHA-treated sides. Adverse event duration was similar for both groups and generally resolved within 14 to 21 days. CONCLUSION This CaHA-based product gives significantly longer-lasting correction of nasolabial folds compared to human collagen. Less total material and fewer injections are required. The adverse event profile of the product is similar to the collagen-based product. [source]

A Randomized Trial to Determine the Influence of Laser Therapy, Monopolar Radiofrequency Treatment, and Intense Pulsed Light Therapy Administered Immediately after Hyaluronic Acid Gel Implantation

DERMATOLOGIC SURGERY, Issue 5 2007
MITCHEL P. GOLDMAN MD
BACKGROUND Hyaluronic acid-based dermal fillers, such as hyaluronic acid gel (Restylane, Q-Medical AB, Uppsala, Sweden), are widely used for tissue augmentation of the nasolabial folds. Additional dermatologic treatments using infrared light, radiofrequency (RF), and intense pulsed light (IPL) are also important tools for facial rejuvenation. This study was designed to evaluate whether these therapies could be safely administered immediately after hyaluronic acid gel treatment without compromising the effect of the dermal filler. OBJECTIVE The objective of this study was to confirm or refute any possible subtractive effects of augmentation of the nasolabial folds when followed by 1,320-nm Nd:YAG laser, 1,450-nm diode laser, monopolar RF, and/or IPL treatments. METHODS Thirty-six patients with prominent nasolabial folds were treated with hyaluronic acid gel implantation on one side of the face and hyaluronic acid gel followed by one of the nonablative laser/RF/IPL therapies on the contralateral side of the face. RESULTS There were no statistically significant differences between wrinkle severity or global aesthetic scores for hyaluronic acid gel implantation alone and hyaluronic acid gel with laser/RF/IPL treatment at any time point. In a small sample, histologic changes were not apparent after laser/RF/IPL treatment. CONCLUSIONS Based on this small pilot study, laser, RF, and IPL treatments can safely be administered immediately after hyaluronic acid gel implantation without reduction in overall clinical effect. [source]

Injecting 1000 Centistoke Liquid Silicone With Ease and Precision

DERMATOLOGIC SURGERY, Issue 3 2003
Anthony V. Benedetto DO, FACP
BACKGROUND Since the Food and Drug Administration approved the use of the 1000 centistoke liquid silicone, Silikon 1000, for intraocular injection, the off-label use of this injectable silicone oil as a permanent soft-tissue filler for facial rejuvenation has increased in the United States. Injecting liquid silicone by the microdroplet technique is the most important preventive measure that one can use to avoid the adverse sequelae of silicone migration and granuloma formation, especially when injecting silicone to improve small facial defects resulting from acne scars, surgical procedures, or photoaging. OBJECTIVE To introduce an easy method for injecting a viscous silicone oil by the microdroplet technique, using an inexpensive syringe and needle that currently is available from distributors of medical supplies in the United States. METHOD We suggest the use of a Becton Dickinson 3/10 cc insulin U-100 syringe to inject Silikon 1000. This syringe contains up to 0.3 mL of fluid, and its barrel is clearly marked with an easy-to-read scale of large cross-hatches. Each cross-hatch marking represents either a unit value of 0.01 mL or a half-unit value of 0.005 mL of fluid, which is the approximate volume preferred when injecting liquid silicone into facial defects. Because not enough negative pressure can be generated in this needle and syringe to draw up the viscous silicone oil, we describe a convenient and easy method for filling this 3/10 cc diabetic syringe with Silikon 1000. RESULTS We have found that by using the Becton Dickinson 3/10 cc insulin U-100 syringe, our technique of injecting minute amounts of Silikon 1000 is facilitated because each widely spaced cross-hatch on the side of the syringe barrel is easy to read and measures exact amounts of the silicone oil. These lines of the scale on the syringe barrel are so large and clearly marked that it is virtually impossible to overinject the most minute amount of silicone. CONCLUSION Sequential microdroplets of 0.01 cc or less of Silikon 1000 can be measured and injected with the greatest ease and precision so that inadvertent overdosing and complications can be avoided. [source]

Biomorphic Silicon Carbide Coated with an Electrodeposition of Nanostructured Hydroxyapatite/Collagen as Biomimetic Bone Filler and Scaffold,

Tailoring Cell Behavior on Polymers by the Incorporation of Titanium Doped Phosphate Glass Filler,

Influence of Ti on the Mechanical Properties of AgCuInTi Active Brazing Fillers,

ADVANCED ENGINEERING MATERIALS, Issue 1-2 2009
Matteo Galli
Active brazing fillers were produced by adding Ti to a AgCuIn alloy and used to fabricate ceramic-metal joints. The alloy was investigated by hardness measurements and microscopy analyses and the joints tested in bending. The results show that Ti has a hardening effect. However, for the considered values of Ti addition (0.5,1.5 wt %), the extent of the hardening is insignificantly influenced by the Ti introduced in the filler. [source]

High-Nanofiller-Content Graphene Oxide,Polymer Nanocomposites via Vacuum-Assisted Self-Assembly

ADVANCED FUNCTIONAL MATERIALS, Issue 19 2010
Karl W. Putz
Abstract Highly ordered, homogeneous polymer nanocomposites of layered graphene oxide are prepared using a vacuum-assisted self-assembly (VASA) technique. In VASA, all components (nanofiller and polymer) are pre-mixed prior to assembly under a flow, making it compatible with either hydrophilic poly(vinyl alcohol) (PVA) or hydrophobic poly(methyl methacrylate) (PMMA) for the preparation of composites with over 50 wt% filler. This process is complimentary to layer-by-layer assembly, where the assembling components are required to interact strongly (e.g., via Coulombic attraction). The nanosheets within the VASA-assembled composites exhibit a high degree of order with tunable intersheet spacing, depending on the polymer content. Graphene oxide,PVA nanocomposites, prepared from water, exhibit greatly improved modulus values in comparison to films of either pure PVA or pure graphene oxide. Modulus values for graphene oxide,PMMA nanocomposites, prepared from dimethylformamide, are intermediate to those of the pure components. The differences in structure, modulus, and strength can be attributed to the gallery composition, specifically the hydrogen bonding ability of the intercalating species [source]

Processing of urea-formaldehyde-based particleboard from hazelnut shell and improvement of its fire and water resistance

FIRE AND MATERIALS, Issue 8 2009
M. Gürü
Abstract The purpose of this study was to manufacture urea-formaldehyde-based particleboard from hazelnut shell and eliminate its disadvantages such as flammability, water absorption, swelling thickness by using fly ash and phenol-formaldehyde. Synthesized urea-formaldehyde and grained hazelnut shells were blended at different ratios ranging from 0.8 to 3.2 hazelnut shell/urea-formaldehyde and dried at 70°C in an oven until constant weight was reached. In addition, other parameters affecting polymer composite particleboard from hazelnut shell and urea-formaldehyde were investigated to be the amount of fly ash, amount of phenol formaldehyde and the effects of these parameters on bending stress, limit oxygen index, water absorption capacity and swelling in the thickness. The optimization results showed that the maximum bending strength was 4.1N/mm2, at urea-formaldehyde ratio of 1.0, reaction temperature of 70°C, reaction time of 25,min, hazelnut shell/urea-formaldehyde resin of 2.4 and mean particle size of 0.1,mm. Although the limited oxygen index and smoke density of composite particleboard without fly ash has 22.3 and 1.62, with fly ash of 16% (w/w) according to the filler has 38.2 and 1.47, respectively. Water absorption and increase in the swelling thickness exponentially decreased with increasing phenol formaldehyde. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Carbon Nanotube Composites: Hierarchical Composites of Single/Double-Walled Carbon Nanotubes Interlinked Flakes from Direct Carbon Deposition on Layered Double Hydroxides (Adv. Funct.

ADVANCED FUNCTIONAL MATERIALS, Issue 4 2010
Mater.
On page 677, M. Q. Zhao et al. report the fabrication of a hierarchical composite combining one-dimensional single/double walled carbon nanotubes (CNTs) and two-dimensional flakes through direct carbon deposition on layered double hydroxides. The composites can be easily transformed into continuously interlinked CNT layers alternating with calcined lamellar flakes structure. They are found to have the potential for applications in a number or areas, including as an excellent filler for strong polyimide film. [source]

Hierarchical Composites of Single/Double-Walled Carbon Nanotubes Interlinked Flakes from Direct Carbon Deposition on Layered Double Hydroxides

ADVANCED FUNCTIONAL MATERIALS, Issue 4 2010
Meng-Qiang Zhao
Three-dimensional hierarchical nanocomposites consisting of one-dimensional carbon nanotubes (CNTs) and two-dimensional lamellar flakes (such as clay, layered double hydroxides) show unexpected properties for unique applications. To achieve a well-designed structure with a specific function, the uniform distribution of CNTs into the used matrix is a key issue. Here, it is shown that a hierarchical composite of single/double-walled CNTs interlinked with two-dimensional flakes can be constructed via in-situ CNT growth onto layered double hydroxide (LDH) flakes. Both the wall number and diameter of the CNTs and the composition of the flakes can be easily tuned by changing the proportion of the transition metal in the LDH flakes. Furthermore, a structure with continuously interlinked CNT layers alternating with lamellar flakes is obtained after compression. The hierarchical composite is demonstrated to be an excellent filler for strong polyimide films. This study indicates that LDH is an extraordinary catalyst for the fabrication of hierarchical composites with high-quality single/double-walled CNTs. The as-obtained CNTs/calcined LDHs nanocomposite is a novel structural platform for the design of mechanically robust materials, catalysts, ion-transportation, energy-conversion, and other applications. [source]

Transparent Nanocomposites of Radiopaque, Flame-Made Ta2O5/SiO2 Particles in an Acrylic Matrix,

ADVANCED FUNCTIONAL MATERIALS, Issue 5 2005
H. Schulz
Abstract Mixed Ta2O5 -containing SiO2 particles, 6,14,nm in diameter, with closely controlled refractive index, transparency, and crystallinity are prepared via flame spray pyrolysis (FSP) at production rates of 6.7,100,g,h,1. The effect of precursor solution composition on product filler (particle) size, crystallinity, Ta dispersity, and transparency is studied using nitrogen adsorption, X-ray diffraction, optical microscopy, high-resolution transmission electron microscopy (HRTEM), and diffuse-reflectance infrared Fourier-transform spectroscopy (DRIFTS). Emphasis is placed on the transparency of the composite that is made with Ta2O5/SiO2 filler and dimethylacrylate. Increasing Ta2O5 crystallinity and decreasing Ta dispersity on SiO2 decreases both filler and composite transparencies. Powders with identical specific surface area (SSA), refractive index (RI), and Ta2O5 content (24,wt.-%) show a wide range of composite transparencies, 33,78,%, depending on filler crystallinity and Ta dispersity. Amorphous fillers with a high Ta dispersity and an RI matching that of the polymer matrix lead to the highest composite transparency, 86,%. The composite containing 16.5,wt.-% filler that itself contains 35,wt.-% Ta2O5 has the optimal radiopacity for dental fillings. [source]

Large particle hyaluronic acid for the treatment of facial lipoatrophy in HIV-positive patients: 3-year follow-up study

HIV MEDICINE, Issue 3 2010
L Skeie
Objectives Facial lipoatrophy can be a stigmatizing side effect of antiretroviral (AVR) treatment for HIV-infected patients. We sought to evaluate the long-term efficacy and safety of a new formulation of hyaluronic acid that can be injected in larger amounts and into deeper skin layers during 3 years of follow-up. Methods Twenty patients received injections of Restylane SubQÔ. Refill treatment was offered at 12 and 24 months. Treatment effects were evaluated using ultrasound, the Global Aesthetic Improvement Scale, visual analogue scale (VAS) and the Rosenberg self-esteem scale. Results Seventeen patients remained at 36 months. Mean (± standard deviation) total cutaneous thickness increased from 6 ± 1 mm at baseline to 12 ± 1 mm (P<0.001) at 36 months. Response rate (total cutaneous thickness >10 mm) was 70%. Fifteen patients classified their facial appearance as very much or moderately improved. VAS increased from 39 ± 25 to 70 ± 20 (P<0.05) and higher self-esteem scores were reported. Local swelling and tenderness after treatment was common. Persistent papules found in several patients after treatment were removed effectively with hyaluronidase injections. Three patients, treated only at baseline, still had higher total cutaneous thickness scores at 36 months. Conclusions Our results indicate that a large particle hyaluronic acid formulation is a durable and well-tolerated dermal filler for treating HIV-positive patients with facial lipoatrophy. [source]

Hyaluronic acid treatment of facial fat atrophy in HIV-positive patients

HIV MEDICINE, Issue 8 2007
H Bugge
Objectives Facial lipoatrophy can be devastating for HIV-infected patients, with negative effects on self-esteem. In this study, we treated facial fat atrophy in the nasogenian area with hyaluronic acid (Restylane SubQ; Q-Med AB, Uppsala, Sweden). Methods Twenty patients were included in the study. Treatment effects were evaluated at baseline, and at weeks 6, 24 and 52 using ultrasound, the Global Aesthetic Improvement Scale, the Visual Analogue Scale and the Rosenberg Self-Esteem Scale. Results Mean (±standard deviation) total cutaneous thickness increased from 6±1 mm at baseline to 15±3 mm at week 6 (P<0.001), and declined to 10±2 mm at week 52 (P<0.001 vs baseline). The response rate (total cutaneous thickness >10 mm) was 100% at week 6, 85% at week 24 and 60% at week 52. At week 6, all of the patients classified their facial appearance as very much improved or moderately improved. They also reported increased satisfaction with their facial appearance and had higher self-esteem scores. At week 52, 15 of 19 patients still classified their facial appearance as very much improved or moderately improved, although the mean total cutaneous thickness had gradually declined. Conclusions Our results indicate that Restylane SubQ is a useful and well-tolerated dermal filler for treating HIV-positive patients with facial lipoatrophy. [source]

Advanced Calcium Copper Titanate/Polyimide Functional Hybrid Films with High Dielectric Permittivity

ADVANCED MATERIALS, Issue 20 2009
Zhi-Min Dang
A functional hybrid film with high dielectric permittivity and good thermal stability is obtained using calcium copper titanate as filler in a polyimide polymer matrix. The giant dielectric permittivity of the filler and its semiconducting characteristics impart good dielectric properties to the hybrid films. A dielectric permittivity high as 49 is achieved at a 40,vol% filler concentration at 102,Hz. [source]

Biocompatibility of various root canal filling materials ex vivo

INTERNATIONAL ENDODONTIC JOURNAL, Issue 8 2008
R. Scotti
Abstract Aim, To evaluate the biocompatibility of a resin-based endodontic filler (RealSeal) using the indirect cytotoxicity test. Methodology, Human gingival fibroblasts were cultured ex vivo. Pellets of the materials to be tested were incubated for 24, 48, and 72 h at 37 °C under sterile conditions to obtain their eluates. The fibroblasts were exposed to either diluted (50%) or undiluted eluates for 24 h. A culture medium with foetal calf serum was added to the control wells. Cell viability was estimated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide method. The data concerning cell viability were statistically analyzed using one-way anova test and Bonferroni multiple comparisons test. Results, Eluates obtained after 24 h of incubation with the resin filler did not reduce cellular viability. An increase in cellular viability, as compared with control cells, was observed in the gutta-percha group. The undiluted eluate from the polyether material was cytotoxic, causing an 82 ± 4% decrease in cellular viability. Eluates obtained after 48 h of incubation with the resin filler increased cellular viability, whereas the polyether significantly reduced viability. Gutta-percha did not cause any detectable change. After 72 h of incubation the eluate of the resin filler caused an increase in cellular viability, as did gutta-percha, whereas polyether caused a significant decrease. Conclusions, RealSeal resin filler was nontoxic in this laboratory model. Further investigations are necessary to verify its usefulness in clinical applications. [source]

Robust, Conducting, and Transparent Polymer Composites Using Surface-Modified and Individualized Double-Walled Carbon Nanotubes,

ADVANCED MATERIALS, Issue 23 2008
Yong Chae Jung
Double-walled carbon nanotubes (DWNTs), consisting of two concentric coaxial tubes, are proposed as the preferable reinforcing filler in polymers. Chemical moieties, which are selectively introduced on the outer tubes, impart the ability to individualize and provide effective anchoring sites for strong bonding with polymers, while the optical properties of the inner tubes of the DWNTs remain unchanged. [source]

BaTiO3,Epoxy Composites for Electronic Applications

INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 4 2010
Leandro Ramajo
A brief review related with dielectric properties of BaTiO3/epoxy composites is presented. The composites were obtained using the dipping technique. To facilitate the mixing and modify the filler surface, a solvent and a surface coupling agent were used. Intermediate and low concentrations of solvent and silane improved microstructure and dielectric properties of the composite material, whereas higher concentrations led to composites of poor quality. Finally, a model using finite elements was used, in order to predict the composite permittivity in relation to the percentage of filler. Model results were compared with the effective medium theory and experimental results. [source]