Constitutive Modeling of Oriented and Non-oriented Magnetostrictive Particulate Composites.

This study presents a mathematical framework for two-phase magnetostrictive composites composed of oriented and non-oriented magnetostrictive Terfenol-D particles embedded in passive polymer matrices. The phase constitutive behavior of the monolithic Terfenol-D with arbitrary crystal orientations is represented by a recently developed discrete energy averaged model. This unique Terfenol-D constitutive model results in close-form and linear algebraic equations accurately describing the nonlinear magnetostriction and magnetization in magnetostrictive composites subjected to a given loading or magnetic field increment. The effectiveness of this new mathematical framework in capturing magnetostrictive particle size orientation, phase volume fractions, mechanical loading conditions, and magnetic field excitations are validated using a series of experimental data available in literature. Compared to existing models that prevalently addressed particle orientation in composite constitutive level, the model framework in this study directly handles particle orientation in the phase constitutive level, and therefore achieves enhanced efficiency while maintaining comparable accuracy.

Porous Membranes of Polysulfone and Graphene Oxide Nanohybrids for Vanadium Redox Flow Battery.

Porous nanohybrid membranes of polysulfone (PSF) with graphene oxide (GO) nanosheets (PSF/GO membrane) were developed to serve as proton exchange membranes in a vanadium redox flow battery (VRFB). Various ratios of PSF/GO and thickness were investigated to evaluate the optimal voltage efficiency (VE), coulombic efficiency (CE), and energy efficiency (EE) of the VRFB. The pore size, distribution, and hydrophilicity of PSF/GO membranes were studied using scanning electron microscopy (SEM) images and contact angles. Functional groups of GO were evaluated using Raman spectroscopy. The mechanical properties and thermal stability of PSF/GO membranes were analyzed using a tensile tester and thermogravimetric analysis (TGA), respectively. The results show that the mechanical properties of the PSF porous membrane with GO nanosheets were significantly improved, indicating that the addition of graphene oxide nanosheets consolidated the internal structure of the PSF membrane. Cyclic voltammetry revealed an obviously different curve after the addition of GO nanosheets. The CE of the VRFB in the PSF/GO membrane was significantly higher than that in the pristine PSF membrane, increasing from 80% to 95% at 0.6 wt.% GO addition. Moreover, PSF/GO membranes displayed great chemical stability during long-term operation; thus, they can evolve as potential porous membranes for application in VRFBs for green energy storage.

Effective nonlinear responses of three-phase magnetoelectric composites.

A computational method, dubbed simplified unit-cell micromechanics model, is generalized and applied to establish the effective nonlinear responses of three-phase magnetoelectric composites that are composed of two distinct magnetostrictive and piezoelectric phases embedded in elastic polymer matrices. The nature of nonlinear constitutive behavior of each constituent is expected to significantly influence the overall responses of the composites. To obtain the effective nonlinear responses, a mathematical linearization is first introduced to perform the constitutive linearization for the nonlinear materials, and the resulting constitutive equations are then unified and nested into the micromechanics model followed by iterations in order to minimize errors from the linearization process. For the purpose of comparison, we also reformulate the well-established Mori-Tanaka micromechanics model insofar as its mathematical structure is aligned with that of the simplified unit-cell model. Numerical results are first validated against limited experimental measurements available in literature. Parametric studies are then conducted in order to reveal the effect of phase constitutive laws, volume fractions, and geometries on the overall nonlinear responses of there-phase magnetoelectric composites. The contributions of this work complement those of earlier studies that prevalently devoted to two-phase magnetoelectric composites and linear magneto-electro-elastic coupled responses only.

Bi-Functional Radiotheranostics of 188Re-Liposome-Fcy-hEGF for Radio- and Chemo-Therapy of EGFR-Overexpressing Cancer Cells.

Epidermal growth factor receptor (EGFR) specific therapeutics is of great importance in cancer treatment. Fcy-hEGF fusion protein, composed of yeast cytosine deaminase (Fcy) and human EGF (hEGF), is capable of binding to EGFR and enzymatically convert 5-fluorocytosine (5-FC) to 1000-fold toxic 5-fluorocuracil (5-FU), thereby inhibiting the growth of EGFR-expressing tumor cells. To develop EGFR-specific therapy, 188Re-liposome-Fcy-hEGF was constructed by insertion of Fcy-hEGF fusion protein onto the surface of liposomes encapsulating of 188Re. Western blotting, MALDI-TOF, column size exclusion and flow cytometry were used to confirm the conjugation and bio-activity of 188Re-liposome-Fcy-hEGF. Cell lines with EGFR expression were subjected to treat with 188Re-liposome-Fcy-hEGF/5-FC in the presence of 5-FC. The 188Re-liposome-Fcy-hEGF/5-FC revealed a better cytotoxic effect for cancer cells than the treatment of liposome-Fcy-hEGF/5-FC or 188Re-liposome-Fcy-hEGF alone. The therapeutics has radio- and chemo-toxicity simultaneously and specifically target to EGFR-expression tumor cells, thereby achieving synergistic anticancer activity.

A Novel Approach to Increase the Oxygen Permeability of Soft Contact Lenses by Incorporating Silica Sol.

This study presents a novel approach to increase the oxygen permeability of hydrogel by the addition of silica sol. Herein, 2-hydroxyethyl methacrylate (HEMA) was copolymerized with N-vinyl-2-pyrrolidone (NVP) after mixing with silica sol. The resultant hydrogel was subject to characterizations including Fourier-transform infrared (FTIR), equilibrium water content (EWC), contact angle, optical transmittance, oxygen permeability (Dk), tensile test, anti-deposition of proteins, and cytotoxicity. The results showed that with the increase of silica content, the Dk values and Young's moduli increased, the optical transmittance decreased slightly, whereas the EWC and contact angle, and protein deposition were not much affected. Moreover, the cytotoxicity of the resultant poly(HEMA-co-NVP)-SNPs indicated that the presence of silica sol was non-toxic and caused no effect to the growth of L929 cells. Thus, this approach increased the Dk of soft contact lenses without affecting their hydrophilicity.

Performance Enhancement of Vanadium Redox Flow Battery by Treated Carbon Felt Electrodes of Polyacrylonitrile using Atmospheric Pressure Plasma.

A high-performance carbon felt electrode for all-vanadium redox flow battery (VRFB) systems is prepared via low-temperature atmospheric pressure plasma treatment in air to improve the hydrophilicity and surface area of bare carbon felt of polyacrylonitrile and increase the contact potential between vanadium ions, so as to reduce the overpotential generated by the electrochemical reaction gap. Brunauer-Emmett-Teller (BET) surface area of the modified carbon felt is, significantly, five times higher than that of the pristine felt. The modified carbon felt exhibits higher energy efficiency (EE) and voltage efficiency (VE) in a single cell VRFB test at the constant current density of 160 mAcm-2, and also maintains good performance at low temperatures. Moreover, the cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analysis results show that the resistance between electrolyte and carbon felt electrode decreased. As a result, owing to the increased reactivity of the vanadium ion on the treated carbon felt, the efficiency of the VRFB with the plasma-modified carbon felt is much higher and demonstrates better capacity under a 100-cycle constant current charge-discharge test.

Msx2 Supports Epidermal Competency during Wound-Induced Hair Follicle Neogenesis.

Cutaneous wounds in adult mammals typically heal by scarring. However, large full-thickness wounds undergo wound-induced hair follicle neogenesis (WIHN), a form of regeneration. Here, we show that WIHN requires transient expression of epidermal Msx2 in two phases: the wound margin early and the wound center late. Msx2 expression is present in the migrating epithelium during early wound healing and then presents in the epithelium and mesenchyme later in the wound center. WIHN is abrogated in germline and epithelial-specific Msx2 mutant mice. Unlike the full-length Msx2 promoter, a minimal Msx2 promoter fails activation in the wound center, suggesting complex regulation of Msx2 expression. The Msx2 promoter binding sites include Tcf/Lef, Jun/Creb, Pax3, and three SMAD sites. However, basal epithelial-induced BMP suppression by noggin overexpression did not affect WIHN. We propose that Msx2 signaling is required for the epidermis to acquire spatiotemporal competence during WIHN. Topologically, hair regeneration dominates in the wound center, coinciding with late Msx2 expression. Together, these results suggest that intrinsic Msx2 expression supports epithelial competency during hair follicle neogenesis. This work provides insight into endogenous mechanisms modulating competency of adult epidermal progenitors for mammalian ectodermal appendage neogenesis, and offers the target Msx2 for future regeneration-promoting therapies.

Improvement of the surface wettability of silicone hydrogel contact lenses via layer-by-layer self-assembly technique.

The surface wettability and anti-protein adsorption of a silicone-based hydrogel that was synthesized by a block copolymer of polydimethylsiloxane (PDMS) and poly (ethylene glycol) methacrylate (PEGMA) was improved via polyelectrolyte multilayer (PEM) immobilization. Polysaccharide PEMs of chitosan (CS, as a positive-charged agent) and hyaluronic acid (HA, as a negative-charged and anti-adhesive agent) were successfully assembled on the PDMS-PU-PEGMA silicone hydrogel in a layer-by-layer (LBL) self-assembly manner. Atomic force microscopy (AFM) and dyeing data verified the progressive buildup of the PEM silicone hydrogel. The results showed that the contact angle of the silicone hydrogel decreased with an increase in the number of PEM grafting layers. Furthermore, after immobilizing five layers of CS/HA, the protein adsorption decreased from 78 ± 11 to 26 ± 4 µg/cm(2) for HSA and from 55 ± 10 to 20 ± 4 µg/cm(2) for lysozymes. This indicates that CS/HA PEM-immobilized silicone hydrogels can resist protein adsorption. Furthermore, these hydrogels were non-cytotoxic according to an in vitro L929 fibroblast assay. Overall, the results demonstrated that the modified silicone hydrogels exhibited hydrophilicity and anti-protein adsorption, as well as relatively high oxygen permeability and optical transparency. Therefore, they would be applicable as a contact lens material.

The teratogenicity and the action mechanism of gallic acid relating with brain and cervical muscles.

Gallic acid (3,4,5-trihydroxybenzoic acid) (GA) and other flavanoids are extensively used in nutraceuticals because of their antioxidant and antiinflammatory properties. While examining whether GA is effective in alleviating valproic-acid-induced teratogenesis in a chicken embryo model (CEM), we observed embryo hemorrhage and liposis in the musculi longissimus cervicis. We conducted this study to determine whether GA is inherently teratogenic and the extent to which the risk can be transferred to fetuses. A CEM was used to administer GA at 2, 6, 10, and 14 µM. GA at 2 µM did not exhibit cytotoxicity. At 6, 10, and 14 µM, GA caused severe decreases in body and liver weights, causing -5.6%, -21.3%, and -27.5% body weights and 4.0, 3.8, and 3.2-g, liver weights, respectively, in day-1 chicks. The optimal alive birth rate (or damaging rate) reached 33.3%, 39.4%, and 29.2% at 6, 10, and 14 µM GA, respectively. The damaged tissue was primarily cervical muscle (musculi longissimus cervicis), as evidenced by liposis, Zenker's necrosis, and hemolysis. The erythrocyte, hemoglobin, eosinophil, lymphocyte, and monocyte counts were severely reduced and PPAR-α was downregulated, whereas the Ras/Raf/JAK/STAT pathway was upregulated. The GA dose required to induce teratogenesis was ≥ 6 µM (1.02 mg/kg), which can be easily consumed by pregnant women in typical teas such as Chinese Pu-'Er and Chinese black teas, indicating a potential risk to human fetuses. GA at doses ≥ 1.02 mg/kg of body weight potentially causes characteristic cerebral hemolysis and liposis in the musculi longissimus cervicis. The mechanism of action of GA is multidisciplinary: The liposis can be ascribed to downregulation of PPAR-α; the erythrocyte hemolysis can be attributed to its unique autooxidative and prooxidant behavior and the inhibition of carbonic anhydrase; and the proliferation and differentiation deficits can be attributed to the upregulation of the Ras/Raf/JAK/STAT pathway.

Preparation and imaging of rhenium-188 labeled human serum albumin microsphere in orthotopic hepatoma rats.

OBJECTIVE: The present study relates to a method for preparing 188Re-labeled human serum albumin microspheres (HSAM) by 188Re(I)-tricarbonyl ion(188Re(OH2)3(CO)3)+). This radioactive particle can be subjected to radioembolization for liver tumor. METHODS: The particle sizes and conformations of HSA microspheres were analyzed by Particle sizes-Malvern mastersizer and Scanning Electron Microscope (SEM). For preparing 188Re(I)-tricarbonyl ion, the 188ReO4- was eluted from a 188W/188Re generator with saline. The radio labeling efficiency was analyzed with high-performance liquid chromatography (HPLC). Amino borane-reduced 188ReO4-was interacted with carbon oxide to form (188Re(OH2)3(CO)3]+). For preparing 188Re-HSA microspheres, the 188Re(I)-tricarbonyl ion was added into a vial with HSA microspheres. The in vitro stability was investigated. The rat was injected with 188Re-HSA microspheres via hepatic artery route. Nano-SPECT/CT Imaging was acquired after injection of 188Re-HSA microspheres. RESULTS: The shape of HSA microsphere was rough surfaced sphere or oval-shaped. The particle size was distributed between 20 and 35µm. In the RP-HPLC-UV chromatography, the yield of 188Re(I)-tricarbonyl ion was 75-80%. The labeling efficiency of 188Re-HSA microspheres in this method was more than 85%. After incubation, the 188Re(I)-tricarbonyl ion labeled HSA microspheres were found to be stable in vitro in normal saline and rat plasma. The result of Nano-SPECT/CT Imaging quantification analysis indicated that the percentage of injection dose %ID was maintained at 95% ID-88% ID from 2 to 72h after injection with 188Re- HSA microspheres. CONCLUSIONS: The method of 188Re(I)-tricarbonyl ion labeled HSA microspheres can proceed with high labeling yield. Furthermore, this method provided a convenient method for radio-labeling of HSA microspheres with 188Re as well as a kit for manufacturing.

Gallic acid exhibits risks of inducing muscular hemorrhagic liposis and cerebral hemorrhage--its action mechanism and preventive strategy.

Gallic acid (3,4,5-trihydroxybenzoic acid) (GA) occurs in many plants. The adverse effects of GA are seldom cited. GA (6-14 µM) provoked the hemorrhagic liposis of the cervical muscles and intracranial hemorrhage. The cause of these pathological events and the method for prevention are still lacking. Using the chicken embryo model and some selected nutraceutics such as folate, glutathione (GSH), N-acetylcysteine, and vitamin E (Vit E), we carried out this study. Results revealed that the action mechanism of GA involved (i) inducing hypoxia with upregulated gene hif-1α and downregulated ratio vegf-r2/vegf-a, leading to dys-vascularization and myopathy; (ii) impairing cytochrome c oxidase; (iii) stimulating creatine kinase and lactate dehydrogenase release; (iv) eliciting carnitine accumulation and liposis via downregulating gene CPT1; (v) suppressing superoxide dismutase and stimulating NO, H2O2, and malondialdehyde; and (vi) depleting erythrocytic and tissue GSH, resulting in hemorrhage. When both Vit E and GSH were applied to the day 1 chicks, a better alleviation effect was revealed. Conclusively, GA potentially exhibits adverse effect by eliciting hemorrhagic liposis of cervical muscles and cerebral hemorrhage. Supplementation with GSH, Vit E, and N-acetylcysteine is able to ameliorate these adverse effects, warranting the importance of restricting the clinical phytotherapeutic doses of GA and related compounds.

Novel silicone hydrogel based on PDMS and PEGMA for contact lens application.

A silicone-based hydrogel was synthesized from poly(dimethylsiloxane) dialkanol (PDMS), isophorone diisocyanate (IPDI), 2-hydroxyethyl methacrylate (HEMA) and poly(ethylene glycol) methacrylate (PEGMA). The hydrophilicity of the resulting block copolymer was adjustable by manipulating the ratio of PDMS and PEGMA. The results showed that higher PEGMA content led to a lower water contact angle, higher water content, lower elastic modulus and higher glucose permeability. At a PEGMA content of 20%, the protein adsorption decreased to 23% and 18% for lysozyme and human serum albumin (HSA), respectively, of those of the control (PDMS-PU). This indicated that the PDMS-PU-PEGMA hydrogels exhibited an ability to resist protein adsorption. The oxygen permeability (Dk) was 92 barrers for the hydrogel with 20% PEGMA. Furthermore, these hydrogels were non-cytotoxic according to an in vitro L929 fibroblast assay. Overall, the results demonstrated that the PDMS-PU-PEGMA hydrogels exhibited not only relatively high oxygen permeability and relative optical transparency, but also hydrophilicity and anti-protein adsorption; therefore, they would be applicable as a contact lens material. Furthermore, this study demonstrated a new approach to controlling the performance of silicone hydrogels.

Mechanical reinforcement of epoxy with self-assembled synthetic clay in smectic order.

Epoxy films containing self-assembled 2D colloidal α-zirconium phosphate nanoplatelets (ZrP) in smectic order were prepared using a simple, energy-efficient fabrication process suitable to industrial processing. The ZrP nanoplatelets form a chiral smectic mesophase with simultaneous lamellar order and helical arrangements in epoxy. The epoxy nanocomposite films are transparent and flexible and exhibit exceptionally high tensile modulus and strength. The findings have broad implications for development of multifunctional materials for engineering applications.

In vitro polyphenolics erythrocyte model and in vivo chicken embryo model revealed gallic acid to be a potential hemorrhage inducer: physicochemical action mechanisms.

The in vivo chicken embryo model (CEM) demonstrated that gallic acid (GA) induced dysvascularization and hypoxia. Inflammatory edema, Zenker's necrosis, hemolysis, and liposis of cervical muscles were the common symptoms. Levels of the gene hif-1α, HIF-1α, TNF-α, IL-6, and NFκB in cervical muscles were all significantly upregulated, while the vascular endothelial growth factor (VEGF) was downregulated in a dose-responsive manner. Consequently, the cervical muscle inflammation and hemolysis could have been stimulated en route to the tissue TNF-α-canonical and the atypical pathways. We hypothesized that GA could deplete the dissolved oxygen (DO) at the expense of semiquinone and quinone formation, favoring the reactive oxygen species (ROS) production to induce RBC disruption and Fe(2+) ion release. To explore this, the in vitro polyphenolics-erythrocyte model (PEM) was established. PEM revealed that the DO was rapidly depleted, leading to the release of a huge amount of Fe (II) ions and hydrogen peroxide (HPO) in a two-phase kinetic pattern. The kinetic coefficients for Fe (II) ion release ranged from 0.347 h(-1) to 0.774 h(-1); and those for Fe (III) ion production were from 6.66 × 10(-3) h(-1) to 8.93 × 10(-3) h(-1). For phase I HPO production, they ranged from 0.236 h(-1) to 0.774 h(-1) and for phase II HPO production from 0.764 h(-1) to 2.560 h(-1) at GA within 6 µM to 14 µM. Thus, evidence obtained from PEM could strongly support the phenomena of CEM. To conclude, GA tends to elicit hypoxia-related inflammation and hemolysis in chicken cervical muscles through its extremely high prooxidant activity.

Verifying expressed transcript variants by detecting and assembling stretches of consecutive exons.

We herein describe an integrated system for the high-throughput analysis of splicing events and the identification of transcript variants. The system resolves individual splicing events and elucidates transcript variants via a pipeline that combines aspects such as bioinformatic analysis, high-throughput transcript variant amplification, and high-resolution capillary electrophoresis. For the 14 369 human genes known to have transcript variants, minimal primer sets were designed to amplify all transcript variants and examine all splicing events; these have been archived in the ASprimerDB database, which is newly described herein. A high-throughput thermocycler, dubbed GenTank, was developed to simultaneously perform thousands of PCR amplifications. Following the resolution of the various amplicons by capillary gel electrophoresis, two new computer programs, AmpliconViewer and VariantAssembler, may be used to analyze the splicing events, assemble the consecutive exons embodied by the PCR amplicons, and distinguish expressed versus putative transcript variants. This novel system not only facilitates the validation of putative transcript variants and the detection of novel transcript variants, it also semi-quantitatively measures the transcript variant expression levels of each gene. To demonstrate the system's capability, we used it to resolve transcript variants yielded by single and multiple splicing events, and to decipher the exon connectivity of long transcripts.

Fabrication and characterization of ophthalmically compatible hydrogels composed of poly(dimethyl siloxane-urethane)/Pluronic F127.

The novel poly(dimethyl siloxane-urethane)/Pluronic hydrogel was fabricated to develop a new ophthalmically compatible material. In this study, the soft segment consists of poly(dimethylsiloxane) dialkanol having hydroxyethyl propoxy end groups and hard segment consists of isophorone diisocyanate (IPDI). The poly(ethylene glycol) methacrylate (PEGMA) was added as the chain-extender to form UV-curable silicone marcomer. Finally, the semi-interpenetrating network (semi-IPN) hydrogel was achieved by reacting with silicone marcomer and Pluronic F127 triblock copolymer under UV-photopolymerization (mSi-PU/F127). It was found that the increase in Pluronic F127 content led to decreased water contact angle and increased the water content of silicone hydrogels. Elastic modulus also decreased with Pluronic F127 content, while surface roughness did not significantly differ from silicone controls. The Pluronic F127 content reached 4%, the apparent protein adsorption amount decreased about 60% in comparison with that of mSi-PU control. It indicated that the mSi-PU/F127 hydrogel membrane had an excellent ability to resist protein adsorption. Additionally, the oxygen permeability (Dk) would decrease 24%, as compared with mSi-PU control. Furthermore, these hydrogel membranes were regarded as non-cytotoxic through in vitro L929 fibroblasts proliferation assay. Overall results demonstrated that the mSi-PU/F127 semi-IPN hydrogel provided silicone hydrogel materials not only having relatively high oxygen permeability and a relatively low modulus, but also enhancing hydrophilicity and anti-protein adsorption.

Hemocompatibility and cytocompatibility of styrenesulfonate-grafted PDMS-polyurethane-HEMA hydrogel.

Copolymerization of polydimethylsiloxane, polyurethane, and hydroxyethyl methacrylate (PDMS-PU-HEMA) hydrogel was performed. After treating with oxygen plasma, the sodium salt of 4-styrenesulfonic acid (NASS) was grafted onto the hydrogel in a one-step process. The surface density of peroxide active groups was determined by the iodide method. The hydrophilicity of the hydrogels surface was evaluated by measuring the water contact angle and water retention. The result demonstrated that oxygen plasma treatment and NASS grafting can improve the hydrophilicity. In addition, in order to evaluate cell compatibility, L929 fibroblasts cells were cultured on the surface of these hydrogels and the cell number was determined by the MTT testing. The results show that plasma treatment and NASS grafting can cause higher cell adhesion and cell growth rates than untreated PDMS-PU-HEMA. Furthermore, NASS grafting can also reduce the platelet adhesion and protein adsorption, hence effectively extending the blood coagulation times. Consequently hydrophilicity, cytocompatibility and hemocompatibility were greatly enhanced by the NASS grafting of PDMS-PU-HEMA.

Construction of antithrombogenic polyelectrolyte multilayer on thermoplastic polyurethane via layer-by-layer self-assembly technique.

The improvement of hydrophilicity and hemocompatibility of thermoplastic polyurethane (TPU) film was developed using surface modification of polyelectrolyte multilayers (PEMs) deposition. The polysaccharide PEMs included chitosan (CS, as a positive-charged agent) and dextran sulfate (DS, as a negative-charged and an antiadhesive agent) that were successfully prepared on the aminolyzed TPU film in a layer-by-layer (LBL) self-assembly manner. X-ray photoelectron spectroscopy (XPS), field-emission scanning electronic microscopy (FE-SEM), and atomic force microscopy (AFM) data will verify the progressive buildup of the PEMs film. The obtained results showed that the contact angle and Zeta-potential reached the steady value after four bilayers of coating, hence proving that the full coverage of coating with PEM layers was achieved. It could be found that the PEMs-deposited TPU films with DS as the outmost layer could resist the platelet adhesion and human plasma fibrinogen (HPF) adsorption, thereby prolonging effectively the blood coagulation times. Besides, the results of growth inhibition index (GI) of L929 fibroblast proliferation suggested that the as-fabricated TPU films were noncytotoxic. Overall results demonstrated that such an easy, valid, shape-independent, and noncytotoxic processing should be potential for the ion of TPU substrate in the application of hemodialysis or cardiovascular devices.

Cytocompatibility and antibacterial activity of a PHBV membrane with surface-immobilized water-soluble chitosan and chondroitin-6-sulfate.

A water-soluble chitosan (WSC)/chondroitin-6-sulfate (ChS) polyelectrolyte complex (PEC) is covalently immobilized onto the surface of poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) (PHBV) membranes via ozone-induced oxidation and poly(acrylic acid) (PAA) graft polymerization. To characterize the modified membranes, X-ray photoelectron spectroscopy (XPS) and water contact angle measurements are performed. It is shown that by coupling WSC as a spacer, the amount of ChS immobilized can be significantly increased. The water contact angle decreases with the amount of PAA, WSC, and ChS immobilized, which indicates the improving hydrophilicity. After WSC- and PEC-immobilization modification, the PHBV membranes possess antibacterial activity against S. aureus, E. coli, P. aeruginosa, and Methicilin resistant Staphylococus aureus (MRSA). According to the L929 fibroblast cell growth inhibition index, the as-prepared PHBV membranes are non-cytotoxic. In addition, the in-vitro evaluation of L929 fibroblast attachment, proliferation, and viability of PEC-immobilized PHBV membranes are ascertained to be superior to those of immobilized WSC or ChS alone. The overall results demonstrate that WSC/ChS PEC immobilization can not only improve the hydrophilicity and cytocompatibility of the PHBV membrane, but also endows antibacterial activity. [GRAPH: SEE TEXT] The bacterial survival ratio of as-prepared PHBV membranes (n=3).

Enhancement of the angular selectivity in encrypted holographic memory.

Enhancement of the angular selectivity in a double random-phase encoded holographic memory by use of reference plane waves is presented. In the storage algorithm, the angular selectivity is improved with the effect of random-phase masks. We show that the angular selectivity achieved by this scheme is more sensitive than that for Bragg angle detuning in a 90 degrees geometry. Both theoretical and experimental results are presented and analyzed.