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This study investigates surface oxidized layers of Cu-Fe-Zn-P (C194) and Cu-Ni-Si-Mg (C7025) lead frames under different oxidation conditions and their influence on the adhesion of epoxy molding compounds with lead frames. Micro-etching and electroplating are adopted to roughen the surface. Isothermal heat treatments which simulate molding and curing processes, as well as high temperature aging, are carried out to oxidize lead frame surface. According to the absorption peaks of FTIR (Fourier transform infrared spectroscopy) spectra, the topmost surface of the oxide layer can be easily identified. In combination with the reduction potential and time obtained from the coulometric reduction test, the variation of oxide phases along the through-thickness direction can also be revealed. Experimental results show that in addition to surface roughness, surface oxides and their thickness play more important roles in the interfacial strength between lead frames and epoxy molding compounds. In the case of the surface with one single Cu 2 O layer, an increase in oxide layer results in a decrease in bonding strength. Once the topmost surface forms CuO, the bonding strength could be enhanced due to a greater surface energy. Compared with electroplated C194, the thinner surface oxide layer and thus better performance in adhesion strength for electroplated C7025 can be ascribed to the immersion Ag surface treatment. • Surface oxidation layer of commercial lead frames was studied. • FTIR and electrochemical mean explored oxide on lead frame surface and underneath. • CuO formation leads to a greater EMC adhesion because of high surface energy. [ABSTRACT FROM AUTHOR]

An antisolvent (iodobenzene, IB) was used to assist the formation of closely packed CH 3 NH 3 PbI 3 (MAPbI 3 ) thin films during the one-step spin-coating process using different volumes of IB. The morphological, structural, optical and excitonic properties of MAPbI 3 thin films were analyzed using a contact-mode atomic-force microscope, X-ray diffractometer, broadband absorbance spectrometer and optical microscope-based time-resolved photoluminescence spectrometer. The properties of the resultant MAPbI 3 thin films can be manipulated by using different IB volumes, which dominates the device performance of MAPbI 3 based photovoltaic cells. The experimental results show that the grain size (or particle size) of MAPbI 3 thin films influences the collection of photoexcited carriers and the contact at the 6,6-Phenyl C 61 butyric acid methyl ester (PCBM)/MAPbI 3 interface, thereby resulting in a trade-off between the fill factor (FF) and short-circuit current density (J SC ). In addition, it is predicted that the power conversion efficiency (PCE) can be further improved by increasing the crystallinity of the MAPbI 3 thin film while keeping the small grain size. [ABSTRACT FROM AUTHOR]

The redox performances of 1–10 wt% Na-modified Fe 2 O 3 /Al 2 O 3 oxygen carrier from seawater were investigated using syngas/air as reactive gases in the thermogravimetric analyzer (TGA) and lab-scaled semi-fluidized bed reactor (semi-FzBR). NaNO 3(aq) as the source of sodium dopants to prepare Na-contained solution was implemented by an air atmospheric pressure plasma jet (Air-APPJ) process, which can increase the feasibility of seawater. For the prepared samples, the materials properties, including crystalline phases, surface morphologies, surface areas, and attrition loss performances were well correlated with the Na contents. The results indicated that the poor reduction kinetics and attrition resistance were obtained with the Na adjunction over 5 wt%, attributing to the sintering issue on excessive phases of Na 2 (Al, Fe) 12 O 19 and Na(Al, Fe)O 2 solid solution in the samples. Therefore, the slight incorporation of Na content in the Fe 2 O 3 /Al 2 O 3 samples which improved the reduction rate was proved as the candidate oxygen carriers. Particularly, the Na content with 1 wt% in Fe 2 O 3 /Al 2 O 3 sample (Na1FA32) can significantly promote the reduction behavior, thermal stability, and attrition resistance as compared to the raw Fe 2 O 3 /Al 2 O 3 oxygen carrier. It is environmentally beneficial to use the Na1FA32 as oxygen carrier in a practical chemical looping combustion process. [ABSTRACT FROM AUTHOR]

The relative abundance and low cost of electric arc furnace dust (EAFD) make it a viable oxygen carrier for chemical looping combustion (CLC) system. Under a reducing agent, zinc ferrite (ZnFe 2 O 4 ) phase in EAFD releases zinc vapor in a complex gas-solid reaction. In an effort to suppress the emission of zinc vapor, the reaction mechanism of ZnFe 2 O 4 prepared as an oxygen carrier in a redox cycling test is primarily discussed, as well as the issue of coupling with an inert Al 2 O 3 support. The study focused the investigation on redox cycling behavior and CO2 conversion in ZnFe 2 O 4 /Al 2 O 3 and EAFD/Al 2 O 3 systems using a thermogravimetric analyzer (TGA) and fixed-bed reactor (FxBR). In a lab-scaled semi-fluidized bed reactor (semi-FzBR) of EAFD/Al 2 O 3 as an oxygen carrier system, a high CO gas yield approximately 0.98 after fifty redox cycles is also experimentally obtained. It can be anticipated that the use of EAFD/Al 2 O 3 system as an oxygen carrier in a reversible CLC process could be economical and environmentally beneficial. [ABSTRACT FROM AUTHOR]

The use of seawater as catalytic agents for hematite (Fe 2 O 3 ) as oxygen carrier in chemical looping combustion process is attractive, because of its abundance and low cost. Unfortunately, seawater itself with major NaCl compound under reactive species accompanying the volatilization of chlorine-containing gases probably lead to the corrosion on reactors during the combustion process. In this study, the feasibility evaluation of sodium dopants extracted from seawater as an effective catalytic agent via an air atmospheric pressure plasma jet (Air-APPJ) is performed, and as such it is combined with Fe 2 O 3 /Al 2 O 3 to assess any possible enhancement on the reduction kinetics. The sodium-contained solutions, NaNO 3(aq) and NaCl (aq) , as precursors are used to prepare the sodium dopants due to the evaporation-decomposition of water and dissolved salts via plasma discharge reaction. The sodium-modified Fe 2 O 3 /Al 2 O 3 oxygen carrier can significantly promote the efficiency of the carbon capture efficiency and CO 2 yield. Especially for the NaCl (aq) as precursor in an Air-APPJ system, the high carbon capture efficiency, CO 2 molar fraction and CO 2 yield around 0.96, 0.95 and 0.91 after fifty redox cycle for the sodium-modified Fe 2 O 3 /Al 2 O 3 oxygen carrier are achieved. It can be anticipated that the sodium-modified Fe 2 O 3 /Al 2 O 3 from seawater by an Air-APPJ system as an oxygen carrier candidate in a reversible CLC process would be notably attractive. [ABSTRACT FROM AUTHOR]

Chronic brain stimulation has become a promising physical therapy with increased efficacy and efficiency in the treatment of neurodegenerative diseases. The application of deep brain electrical stimulation (DBS) combined with manganese-enhanced magnetic resonance imaging (MEMRI) provides an unbiased representation of the functional anatomy, which shows the communication between areas of the brain responding to the therapy. However, it is challenging for the current system to provide a real-time high-resolution image because the incorporated MnCl 2 solution through microinjection usually results in image blurring or toxicity due to the uncontrollable diffusion of Mn 2+ . In this study, we developed a new type of conductive nanogel-based neural interface composed of amphiphilic chitosan-modified poly(3,4 -ethylenedioxythiophene) (PMSDT) that can exhibit biomimic structural/mechanical properties and ionic/electrical conductivity comparable to that of Au. More importantly, the PMSDT enables metal-ligand bonding with Mn 2+ ions, so that the system can release Mn 2+ ions rather than MnCl 2 solution directly and precisely controlled by electrical stimulation (ES) to achieve real-time high-resolution MEMRI. With the integration of PMSDT nanogel-based coating in polyimide-based microelectrode arrays, the post-implantation DBS enables frequency-dependent MR imaging in vivo , as well as small focal imaging in response to channel site-specific stimulation on the implant. The MR imaging of the implanted brain treated with 5-min electrical stimulation showed a thalamocortical neuronal pathway after 36 h, confirming the effective activation of a downstream neuronal circuit following DBS. By eliminating the susceptibility to artifact and toxicity, this system, in combination with a MR-compatible implant and a bio-compliant neural interface, provides a harmless and synchronic functional anatomy for DBS. The study demonstrates a model of MEMRI-functionalized DBS based on functional neural interface engineering and controllable delivery technology, which can be utilized in more detailed exploration of the functional anatomy in the treatment of neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

Abstract: Chitosan is among the most abundant biopolymers on earth and has been either used or exhibited potential in a wide variety of industrial and biomedical applications. With the advancement of materials technologies, chitosan has been chemically modified to self-assemble into nanoarchitectures that are usable in advanced biomedical applications, such as drug nanocarriers, macroscopic injectables, tissue-engineering scaffolds, and nanoimaging agents. Colloidal amphiphilically modified chitosan (AMC) is a relatively recent material receiving increased attention with numerous publications addressing the medical advantages of specific systems. To date, many reviews have focused on the synthesis and biomedical properties of chitosan-based biomaterials, but a comprehensive study focusing on the colloidal properties of AMC in relation to biomedical performance appears to be lacking. This review provides a survey of the field, critically reviewing the colloidal properties and biomedical performance of AMC systems, such as nanoparticle drug delivery systems and macroscopic medical devices. Finally, the future development, market potential, and clinical implications of these promising colloidal-structured biomaterials are summarised. [Copyright &y& Elsevier]

Abstract: A flexible drug delivery device was designed and fabricated using electrophoretic deposition of drug-carrying magnetic core-shell Fe3O4 at SiO2 nanoparticles onto an electrically conductive flexible PET substrate. The PET substrate was first patterned to a desired layout and subjected to deposition. In doing so, a uniform and nanoporous membrane could be produced. After lamination of the patterned membranes, a final chip-like device of thickness less than 0.5mm is formed that is used for controlled delivery of an anti-epileptic drug, i.e., ethosuximide (ESM). The release of useful drugs can be controlled by directly modulating the magnetic field, and the chip is capable of demonstrating a variety of release profiles (i.e., slow release, sustained release, step-wise release and burst release profiles). These profiles can follow a wide spectrum of patterns ranging from zero to pulsatile release kinetics depending on the mode of magnetic operation. When the magnetic field was removed, the release behavior was instantly ceased, and vice versa. A preliminary in-vivo study using Long–Evans rat model has demonstrated a significant reduction in spike-wave discharge after the ESM was burst released from the chip under the same magnetic induction as in-vitro, indicating the potential application of the drug delivery chip. The flexible and membrane-like drug delivery chip utilizes drug-carrying magnetic nanoparticles as the building blocks that ensure a rapid and precise response to magnetic stimulus. Moreover, the flexible chip may offer advantages over conventional drug delivery devices by improvement of dosing precision, ease of operation, wider versatility of elution pattern, and better compliance. [Copyright &y& Elsevier]

Electrochemical impedance spectroscopy (EIS) applied for aptasensing is being extensively studied for a variety of targets. Substitution of a symmetric electrode configuration for a conventional three-electrode setup on EIS aptasensing is becoming a trend due to its simple and favorable characteristics for biochip fabrication. However, a single Randles circuit is often used for impedance element parameter fitting in symmetric electrode aptasensing without rationalized basis of validity to date. In this work, an AC impedance model is derived for proving the validity of simplifying a symmetric Randles circuits in series into a single one and is examined with aptasensing applications. With the model, circuit parameter relationships can be quantified and correlated between symmetric and three-electrode configurations. The relationships are verified by comparing the fitted parameters obtained from standard gold electrodes (SGEs), microfabricated symmetric Au electrodes, and interdigitated array (IDA) Au electrode chips with different surface and detection conditions. The model is then found valid for different redox species composition (either Fe(CN) 6 3− or Fe(CN) 6 3−/4- is used) and for both blank and aptamer modified surfaces. From aptasensing of thrombin and tumor marker mucin 1 (MUC1), it is proved that the measured dissociation constants (K D : 129.4 nM for thrombin and 16.3 nM for MUC1) remain the same between a symmetric and three-electrode configuration, but the maximum change of charge transfer resistance (B max) is doubled in the symmetric one. This means that the symmetric configuration not only yields the same K D , but also results in a doubled binding signal for EIS aptasensing. In addition to the model derivation and experimental validation, specific EIS aptasensing of MUC1 using a symmetric electrode configuration is successfully demonstrated in this work. • EIS parameter relationship between a single and symmetric Randles circuit for aptasensing is derived. • The model holds for both symmetric and IDA chips, for different ratios of redox species, and for DNA modified surfaces. • EIS aptasensors for specific detection of thrombin and mucin-1 are fabricated using symmetric Au electrodes. • The aptasensors are fabrication favorable and simple to setup with only two electrodes being involved. • The model can be implemented for affinitive analysis of aptamer-protein binding, where K D and B max can be calculated. [ABSTRACT FROM AUTHOR]

The possibility of using electric arc furnace dust (EAFD) as regenerable sorbents to adsorptive hydrogen sulfide was studied. To avoid the releasing of zinc vapor and leaching of heavy metal matter, the addition of Al 2 O 3 was used as inert stabilizer to suppress the volatilization of zinc vapor and generate a more stable chemical forms in EAFD. The results of redox behavior and toxicity characteristic leaching procedure show that Al 2 O 3 are excellent stabilizers for EAFD of industrial waste. Multi-cycle tests of sulfidation/regeneration showed that the prepared EAFD/Al 2 O 3 sorbents can be regenerated and thus reused after the regeneration process. After ten sulfidation/regeneration cycles, the sulfur capacity of the tenth cycle remained approximately on a level of 79% of the sulfur capacity in the first cycle. The results based on the material characterization and sulfidation/regeneration performance evaluation showed that EAFD/Al 2 O 3 sorbent has desirable physical and chemical properties for the desulfurization of simulated syngas at high-Temperature range. Therefore, EAFD with addition of Al 2 O 3 has a potential utilization for the removal of hydrogen sulfide. [ABSTRACT FROM AUTHOR]

We developed a surfactant-free method utilizing amifostine to stably link a targeting ligand (Herceptin) to amphiphilic gelatin (AG)-iron oxide@calcium phosphate (CaP) nanoparticles with hydrophobic curcumin (CUR) and hydrophilic doxorubicin (DOX) encapsulated in the AG core and CaP shell (AGIO@CaP-CD), respectively. This multi-functional nanoparticle system has a pH-sensitive CaP shell and degradable amphiphilic gelatin (AG) core, which enables controllable sequential release of the two drugs. The dual-targeting system of AGIO@CaP-CD (HER-AGIO@CaP-CD) with a bioligand and magnetic targeting resulted in significantly elevated cellular uptake in HER2-overexpressing SKBr3 cells and more efficacious therapy than delivery of targeting ligand alone due to the synergistic cell multi-drug resistance/apoptosis-inducing effect of the CUR and DOX combination. This nanoparticle combined with Herceptin and iron oxide nanoparticles not only provided a dual-targeting functionality, but also encapsulated CUR and DOX as a dual-drug delivery system for the combination therapy. This study further demonstrated that the therapeutic efficacy of this dual-targeting co-delivery system can be improved by modifying the application duration of magnetic targeting, which makes this combination therapy system a powerful new tool for in vitro/in vivo cancer therapy, especially for HER2-positive cancers. [ABSTRACT FROM AUTHOR]

Abstract: This study fabricated hydrogenated diamond-like carbon/silver bioceramic films on glass substrates using radio frequency magnetron sputtering with a single silver target in an atmosphere of Ar/CH4 mixture. The effects of applied power on the composition and microstructure of bioceramic film were evaluated. A phase transformation, amorphous diamond-like carbon → nano-silver precipitation → nano-silver growth in the amorphous diamond-like carbon matrix was observed during sputtering. The film growth rate, surface roughness, silver content and size of silver nanoclusters in the films all increased with the silver target power due to the higher flux of sputtered silver species toward the substrate. [Copyright &y& Elsevier]

Abstract In this study, a facile co-electrodeposition method has been developed to co-deposit iridium oxide and human plasma proteins. We use a cyclic voltammetry (CV) approach for co-electrodeposition on indium tin oxide-coated glass substrates. We adjust the percentages of plasma proteins as 1%, 3%, 5% and 7% to obtain different film thicknesses. We also optimize the number of cycles to achieve the ideal thickness. Cyclic voltammetry, field emission scanning electron microscopy, and Fourier-transform infrared spectroscopy were used for characterizing the deposited film. The results show that the plasma proteins can be successfully co-deposited with iridium oxide. The incorporation of plasma proteins results in an increase in the roughness of the film. The thickness of the electrodeposited layer is dependent on the concentration of plasma proteins. [ABSTRACT FROM AUTHOR]

Comprehensive studies were carried out to explore the roles of phenyl-C 61 -butyric acid methyl ester (PCBM) thin films in inverted-type CH 3 NH 3 PbI 3 (MAPbI 3 ) based photovoltaics, including the surface morphologies, transmittance spectra, photoluminescence spectra, X-ray diffraction (XRD) patterns, Raman scattering spectra and thin-film residual stress analysis. The reduction in the photoluminescence line width indicates that the crystallinity of the MAPbI 3 thin film can be increased by covering it with the PCBM thin film. The XRD patterns and Raman scattering spectra show a reduction in the compressive stress of MAPbI 3 thin film when covered by the PCBM thin film. In addition, it is noted that the residual stress at the contact interface between the hydrophilic MAPbI 3 and the hydrophobic PCBM can be ignored as confirmed by the results obtained with a home-made Twyman-Green interferometer. Consequently, the superior optoelectronic properties of the perovskite materials, as well as the use of a multifunctional fullerene-based thin film as the capping layer allow for the high-efficiency perovskite photovoltaics. [ABSTRACT FROM AUTHOR]

A series of nonpolar antisolvents (chlorobenzene, bromobenzene, iodobenzene and toluene) were used to assist in the formation of smooth and crystalline CH 3 NH 3 PbI 3 thin films by a one-step spin-coating method. The structural, optical and excitonic characteristics of the resultant CH 3 NH 3 PI 3 thin films were analyzed using an atomic-force microscope, X-ray diffractometer, absorbance spectrum, photoluminescence (PL) spectrum, time-resolved PL and temperature-dependent PL. The properties of the CH 3 NH 3 PbI 3 thin films are dependent on the relative polarity and boiling point of the nonpolar antisolvents used in the washing treatment process. The interplay between nucleation (relative polarity) and crystal growth (boiling point) during the formation of CH 3 NH 3 PbI 3 thin films influences the short-circuit current density (J SC ) and power conversion efficiency (PCE) of the corresponding solar cells. The experimental results demonstrate that iodobenzene can be substituted for toluene as a more efficient antisolvent in the washing treatment process during the fabrication of CH 3 NH 3 PbI 3 thin films. In addition, it is predicted that the J SC and PCE can be further improved by increasing the crystallinity of the CH 3 NH 3 PbI 3 thin film. [ABSTRACT FROM AUTHOR]

Although traditional 3D scaffolds or biomimetic hydrogels have been used for tissue engineering and regenerative medicine, soft tissue microenvironment usually has a highly anisotropic structure and a dynamically controllable deformation with various biomolecule distribution. In this study, we developed a hierarchical hybrid gelatin methacrylate-microcapsule hydrogel (HGMH) with Neurotrophin-3(NT-3)-loaded PLGA microcapsules to fabricate anisotropic structure with patterned NT-3 distribution (demonstrated as striped and triangular patterns) by dielectrophoresis (DEP). The HGMH provides a dynamic biomimetic sinuate-microwrinkles change with NT-3 spatial gradient and 2-stage time-dependent distribution, which was further simulated using a 3D finite element model. As demonstrated, in comparison with striped-patterned hydrogel, the triangular-patterned HGMH with highly anisotropic array of microcapsules exhibits remarkably spatial NT-3 gradient distributions that can not only guide neural stem cells (NSCs) migration but also facilitate spinal cord injury regeneration. This approach to construct hierarchical 4D hydrogel system via an electromicrofluidic platform demonstrates the potential for building various biomimetic soft scaffolds in vitro tailed to real soft tissues. [Display omitted] [ABSTRACT FROM AUTHOR]

A technique was proposed to concentrate the distribution of set voltages. After a plasma treatment, the stability of the high-resistive state (HRS) increased, and the distribution of set voltages was more concentrated at 0.8 V, with a sufficient HRS/LRS resistive ratio (∼100x). In addition, the surface of the TiN electrode became rougher, causing oxygen to enter the TiN electrode and form a TiON layer, which acts as an oxygen reservoir. The reservoir is confirmed and the conduction model is supported by both electrical and material analyses. We propose that the observed improvement is due to the difference in the TiN electrode surface. Image 1 • Applied the plasma treatment on electrode to stabilize set voltage. • Construct the physical model to explain abnormal current conduction. • Complete electrical and material analysis were performed in this work. [ABSTRACT FROM AUTHOR]