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We report infrared (IR) pulse laser-activated highly efficient parallel intracellular delivery by using an array of titanium microdish (TMD) device. Upon IR laser pulse irradiation, a two-dimensional array of TMD device generated photothermal cavitation bubbles to disrupt the cell membrane surface and create transient membrane pores to deliver biomolecules into cells by a simple diffusion process. We successfully delivered the dyes and different sizes of dextran in different cell types with variations of laser pulses. Our platform has the ability to transfect more than a million cells in a parallel fashion within a minute. The best results were achieved for SiHa cells with a delivery efficiency of 96% and a cell viability of around 98% for propidium iodide dye using 600 pulses, whereas a delivery efficiency of 98% and a cell viability of 100% were obtained for dextran 3000 MW delivery using 700 pulses. For dextran 10,000 MW, the delivery efficiency was 92% and the cell viability was 98%, respectively. The device is compact, easy-to-use, and potentially applicable for cellular therapy and diagnostic purposes.

Electrodynamic systems for bioanalytical applications constantly suffer from biofouling due to electrical field-induced nonspecific bioadsorption on electrode surfaces. To minimize this issue, surface modification using anti-biofouling and conductive materials is necessary to not only protect the electrode surface from nonspecific bioadsorption but also maintain desired electrodynamic properties for electrode operation. In this study, we designed and prepared a conductive, zwitterionic, and self-doped sulfonated polyaniline (SPANI) coating on Au electrode surfaces for anti-biofouling applications. The zwitterionic coating was fabricated by electrochemical polymerization of aniline on the Au electrode surface functionalized with cysteamine (HS-CH2CH2-NH2) and then a post-polymerization treatment with fuming sulfuric acid. We found that the SPANI-coated electrodes exhibited an excellent anti-biofouling ability in dielectrophoresis (DEP) capturing-and-releasing processes, with a very low average residual mass rate of 1.44% for the SPANI-5s electrode, whereas electrodes modified with poly(ethylene glycol) (PEG) gave an average residual mass rate of 14.30%. Even under continuous operation for more than 1 h, the SPANI-5s electrode still showed stable anti-biofouling ability for an 11-cycle E. coli capturing-and-releasing DEP process, with the residual mass rate for all 11 cycles being kept at or below 2.18% to give an average residual mass rate of 1.62% with a standard deviation of 0.40%. This study demonstrates that electrodynamic systems with zwitterionic SPANI coated on open electrode surfaces can excellently function with decent conductance and anti-biofouling performance.

The ability to deliver foreign cargos into single living cells is of great interest in cell biology and therapeutic research. Here, we have reported a single or multiple position based nano-localized single-cell nano-electroporation platform. The device consists of an array of triangular shape ITO nano-electrodes with a 70 nm gap between two nano-electrodes, each having a 40 nm tip diameter. The voltage is applied between nano-electrodes to generate an intense electric field, which electroporates multiple nano-localized regions of the targeted single-cell membrane, and biomolecules are gently delivered into cells by pressurizing pump flow, without affecting cell viability. The platform successfully delivers dyes, QDs, and plasmids into different cell types with the variation of field strength, pulse duration, and the number of pulses. This new approach allows us to analyze delivery of different biomolecules into single living cells with high transfection efficiency (>96%, for CL1-0 cells) and high cell viability (∼98%), which are potentially beneficial for cellular therapy and diagnostic purposes.

The interaction of molten materials with coolant is of significant fundamental interest and is of paramount importance for nuclear safety and material processing as well. This study explores the quenching of melts of copper spheres and a eutectic mixture of bismuth trioxide and tungsten trioxide (BTOP) in de-ionized water and natural seawater through visualization using a high-speed video camera. The results show no fragmentation in the case of molten copper owing to its high surface tension, while the quench of BTOP in de-ionized water and seawater results in extensive fragmentation. The fragmentation in seawater is characterized by a greater fraction of larger debris than that in the de-ionized water. Moreover, the examination of the debris quenched in seawater using scanning electron microscopy reveals a rougher surface, which demonstrates intensive interactions between the BTOP melts and the seawater owing to the complex ions there.

A microfluidic chip, which can separate and enrich leukocytes from whole blood, is proposed. The chip has 10 switchback curve channels, which are connected by straight channels. The straight channels are designed to permit the inertial migration effect and to concentrate the blood cells, while the curve channels allow the Dean flow to further classify the blood cells based on the cell sizes. Hydrodynamic suction is also utilized to remove smaller blood cells (e.g., red blood cell (RBC)) in the curve channels for higher separation purity. By employing the inertial migration, Dean flow force, and hydrodynamic suction in a continuous flow system, our chip successfully separates large white blood cells (WBCs) from the whole blood with the processing rates as high as 1 &times, 108 cells/sec at a high recovery rate at 93.2% and very few RBCs (~0.1%).

Efficient polymer solar cells were fabricated with regioregular poly 3-hexylthiophene (P3HT):(6,6)-phenyl C61 butyric acid methyl ester (PCBM)) as active layer and molybdenum trioxide (MoO3) and (N,N′-diphenyl)-N,N′-bis(1-naphthyl)-1,1′-biphenyl-4,4′-diamine (NPB) as buffer layers. The results of transient photocurrent and electrochemical impedance spectrometry of device indicate that the insertion of NPB layer between the active layer and MoO3 layer is critical to the enhanced performance. It can effectively prevent charge recombination at the interface of MoO3 hole extraction layer, reduce interfacial resistance due to the formation of Ohmic contact and enhance the exciton dissociation because of the newly formed NPB/PCBM dissociation interface. The optimized thickness of NPB layer is 5 nm, resulting in maximized power conversion efficiency (PCE) of 3.94% under AM1.5G 100 mW cm−2 illumination.

This study reports on morphology dependent antibacterial activities of CuxO/ZnO nanocomposites towards Escherichia coli. The CuxO/ZnO nanocomposites were formed by aqueous photoreduction of CuxO nanostructures on solution grown ZnO nanorods on Si substrates. By controlling the photoreduction time and temperature, various CuxO nanostructures including nanocubes, nanoclusters, nanospikes, and nanowebs were created as verified by scanning electron microscopy. X-ray diffraction analysis reveals the good crystallinity of the ZnO nanorods. X-ray photoelectron spectroscopy confirms the successful deposition of CuO and Cu2O nanostructures on the nanorods. Antibacterial tests were performed in dark and under low-intensity blue-light irradiation. The nanoweb sample has an antibacterial efficiency of 95.8% for 10 min in dark and the nanospike sample has an efficiency of 99.5% for 10 min under light. For the nanospike sample, remarkable bacterial survival ratios of 3 × 10–4 and 10–5 in dark and under light both for a 60 min reaction time, respectively, have been achieved. The excellent antibacterial performance is attributed to combined effects of mechanical piercing of ZnO nanorods, release of Zn2+, Cu2+, and Cu+ ions, and effective generation of reactive oxygen species due to charge separation.

To simultaneously improve both ionic/electronic conduction in many electrochemical devices have received great attention. For example, (Ba,Sr)(Co,Fe)O3 perovskite exhibiting unique hole/oxygen ion mixed conduction behavior becomes important membrane materials for oxygen separation application. In additions, composite electrolytes consisting of multiple ionic conductors have received great attention for high temperature fuel cell application. For instance, enhanced conduction was observed when the oxygen ion conductor, doped ceria, was directly mixed with Li/K carbonates. The electrical conduction of composite electrolyte was contributed by the migration of oxygen ions in solid state and carbonate ions in liquid state. It is believed that ions tend to be highly mobile at the interface between doped ceria and carbonates. As a result, higher conductivity of the composite electrolyte was observed. In other words, the super-ionic conduction path/domain might exist at the interface between doped ceria and carbonates. However, to optimize the mixed conduction, the materials/microstructure designs play an important role. Thus, the objective of this study is to conduct (1) fabrication/design of composite electrolytes (2) microstructure development, (3) characterization of conduction/interfacial kinetics for composite electrolytes in high-temperature fuel cells. High-resolution SEM, XRD, and electrochemical Impedance Spectroscopy are employed to conduct microstructural, structural and impedance analyses. The electrical conduction behavior of composite electrolytes will be rationalized based on the pore size, pore distribution and interfacial area.

In many electrochemical devices, mixed ionic/electronic conduction have received great attention. For instance, oxygen transport membrane (OTM) based on (Ba,Sr)(Co,Fe)O3 perovskite exhibit unique hole/oxygen ion mixed conduction behavior for oxygen separation application. Accordingly, electrodes/electrolytes exhibiting both electronic and/or multiple ionic conducting properties have been used for high temperature fuel cell application. For example, mixed conducting electrodes based on composite electrode (e.g. LSM/SDC, LSM/YSZ) show improved SOFC performance in comparison to conventional electrode. Such unique conduction behavior may be rationalized based on defect chemistry consideration. Thus, the materials processing and microstructure design may become key issues to optimize their mixed conduction properties. For instance, better hole and oxygen conducing perovskite may be obtained when desired aliovalent dopant and oxidizing atmosphere are used. Thus, the objective of this work is to conduct (1) fabrication/design of MIEC through defect-favored processing, (2) microstructure development for better gas transport, (3) characterization of conduction/interfacial kinetics for better electrodes/electrolytes performance. Desired analytical equipment such as SEM, XRD, electrochemical impedance spectroscopy (EIS) and cell testing are performed to conduct microstructural, structural and impedance analyses. The electrical conduction behavior of composite electrode/electrolytes will be discussed based on defect chemistry consideration and individual microstructure and morphology including pore size, pore distribution and interface area.

We simulate and analyze the influence of nonlocal effects on the optical properties of thin metal hollow nanowires by finite element method. Nonlocal effects in hollow nanowires with both nm-sized overall volume and a tiny metal shell are considerable for extinction cross section but more for field enhancement, resulting in nonlocal plasmonic modes excited. Then, we show the dependence of extinction effects of a hollow super-nanowire on its parameters, including the metal shell thickness, the average radius and the optical constant of the hollow core. We find that nonlocal quadrupolar mode is very sensitive to the thickness of metal layer but with great stability as increasing the hollow nanowire dimension or changing the hollow core. Furthermore, the eccentricity of the hollow nanowire brings out new physical phenomena, such as nanofocusing and multimodes. The proposed structure promises a great of applications in nanoscale, such as designing nanoplasmonic antenna, sensing and nonlinear optics, etc.

In this study, smart glass with the property of auto-adjust transparency was constructed to economize the consumption of energy by screening sunlight irradiation entering a building. Graphene oxide (GO), a photothermal conversion material, when intercalated within a thermotropic hydrogel can effectively convert the photoenergy of sunlight into thermal energy and cause the smart glass to reach an opaque state owing to the increased temperature of the hydrogel heated by solar light, as a result, reducing the incident intensity of solar energy and room temperature. In addition, GO embedded within the thermotropic hydrogel absorbs the colored organic solvent, which provides the smart glass with arbitrary color.

An eco-friendly, facile, and efficient method was developed to modify carbon fiber cloth (CFC) having superhydrophobic or hydrophilic properties. The method used polydopamine (PD) as a mediating layer, followed by grafting titanium oxide and poly(N-isopropylacrylamide) (PNIPAM) through mussel adhesion protein-inspired surface chemistry. Carbon fiber cloth with periodic superhydrophobic–hydrophilic patterns was fabricated and its ability for water collection from moisture generated by a humidifier was determined. The patterned CFC exhibited excellent performance in water collection with an efficiency of 206 mg cm−2 h−1, far higher than those of uniform hydrophilic and superhydrophobic surfaces. The carbon fiber cloth grafted with PNIPAM also possesses thermo-responsive properties and swelled dramatically during its volume-phase transition. This study demonstrated that the water permeability of PNIPAM-grafted CFC could be controlled remotely by near infrared laser irradiation. Together, we believe that the modified CFC shows high potential to be used for smart clothes and collecting water from air, and serves as a smart valve in controlling fluid flow for applications in bioreactors and microfluidic systems.

Agglutination is an antigen–antibody reaction with visible expression of aggregation of the antigens and their corresponding antibodies. Applications extend to the identification of acute bacterial infection, hemagglutination, such as blood grouping, and diagnostic immunology. Our finger-powered agglutination lab chip with external CMOS image sensing was developed to support a platform for inexpensive, rapid point-of-care (POC) testing applications related to agglutination effects. In this paper, blood grouping (ABO and Rh grouping) was utilized to demonstrate the function of our finger-powered agglutination lab chip with CMOS image sensing. Blood antibodies were preloaded into the antibody reaction chamber in the lab chip. The blood sample was pushed through the antibody reaction chamber using finger-powered pressure actuation to initiate a hemagglutination reaction to identify the blood type at the on-chip detection area using our homemade CMOS image sensing mini-system. Finger-powered actuation without the need for external electrical pumping is excellent for low-cost POC applications, but the pumping liquid volume per finger push is hard to control. In our finger-powered agglutination lab chip with CMOS image sensing, we minimized the effects of different finger push depths and achieved robust performance for the test results with different push depths. The driving sample volume per finger push is about 0.79 mm3. For different chips and different pushes, the driven sample volume per finger push was observed to vary in the range of 0.64 to 1.18 mm3. The red blood cells were separated from the plasma on-chip after the whole blood sample was finger pumped and before the red blood cells reached the antibody chamber via an embedded plasma-separation membrane. Our homemade CMOS image mini-system robustly read and identified the agglutination results on our agglutination lab chip.

Mixed ionic/electronic conduction in many electrochemical devices have received great attention. For instance, oxygen transport membrane (OTM) based on (Ba,Sr)(Co,Fe)O3 perovskite exhibit unique hole/oxygen ion mixed conduction behavior for oxygen separation application. Moreover, composite electrodes/electrolytes consisting of electronic and/or multiple ionic conductors have received great attention for high temperature fuel cell application. For example, enhanced conduction was observed when the oxygen ion conductor, doped ceria was directly mixed with Li/K carbonates. The electrical conduction of composite electrolyte was contributed by the migration of oxygen ions in solid state and carbonate ions in liquid state. It was observed that the two-phase electrolytes exhibit coionic (O=/H+) conductors during fuel cell operation under the H2/ air atmosphere. It is believed that highly mobile ions at the interface between doped ceria and carbonates may contribute to the high conductivity of the composite electrolyte. In other words, the super-ionic phase might exist at the interface between doped ceria and carbonates, where the defect concentrations are high. Similarly, mixed conducting electrodes based on composite electrode (e.g. LSM/SDC, LSM/YSZ) also show improved SOFC performance in comparison to conventional electrode. However, to optimize the mixed conduction, the materials/microstructure designs play an important role. Thus, the objective of this work is to conduct (1) fabrication/design of MIEC and composites (2) microstructure development, (3) characterization of conduction/interfacial kinetics for electrodes/electrolytes in high-temperature fuel cells. High-resolution SEM, XRD, and Electrochemical Impedance Spectroscopy are employed to conduct microstructural, structural and impedance analyses. The electrical conduction behavior of composite electrode/electrolytes will be rationalized based on the pore size, pore distribution and interface area.

Single-cell electroporation is a powerful technique to understand cellular behavior with heterogeneity, which might be impossible based on bulk measurements of millions of cells together. In this study, a dielectric passivation layer was deposited on top of an indium-tin oxide micro-electrode-based transparent chip surface using a plasma enhanced chemical vapour deposition technique. We theoretically and experimentally investigated the key effects of the dielectric passivation layer on localized single-cell electroporation for different cancer cells, which were randomly distributed with a high density throughout the chip surface as a monolayer. The passivation layer not only prevented the conventional or bulk electroporation with bubble and ion generation, but also provide an intense electric field in-between electrode gap for localized single-cell electroporation with high cell viability. Thus, devices with dielectric passivation layers are potentially applicable for single-cell studies.

Mixed ionic/electronic conduction in many electrochemical devices have received great attention. For instance, oxygen transport membrane (OTM) based on (Ba,Sr)(Co,Fe)O3 perovskite exhibit unique hole/oxygen ion mixed conduction behavior for oxygen separation application. Moreover, composite electrodes/electrolytes consisting of electronic and/or multiple ionic conductors have received great attention for high temperature fuel cell application. For example, enhanced conduction was observed when the oxygen ion conductor, doped ceria was directly mixed with Li/K carbonates. The electrical conduction of composite electrolyte was contributed by the migration of oxygen ions in solid state and carbonate ions in liquid state. It was observed that the two-phase electrolytes exhibit coionic (O=/H+) conductors during fuel cell operation under the H2/ air atmosphere. It is believed that highly mobile ions at the interface between doped ceria and carbonates may contribute to the high conductivity of the composite electrolyte. In other words, the super-ionic phase might exist at the interface between doped ceria and carbonates, where the defect concentrations are high. Similarly, mixed conducting electrodes based on composite electrode (e.g. LSM/SDC, LSM/YSZ) also show improved SOFC performance in comparison to conventional electrode. However, to optimize the mixed conduction, the materials/microstructure designs play an important role. Thus, the objective of this work is to conduct (1) fabrication/design of MIEC and composites (2) microstructure development, (3) characterization of conduction/interfacial kinetics for electrodes/electrolytes in high-temperature fuel cells. High-resolution SEM, XRD, and Electrochemical Impedance Spectroscopy are employed to conduct microstructural, structural and impedance analyses. The electrical conduction behavior of composite electrode/electrolytes will be rationalized based on the pore size, pore distribution and interface area.

Understanding the mechanical properties of bio-adsorbates at the pathological state is important in mechanobiology and medical diagnosis. With the development of biodetection technology, the mechanical properties of bio-adsorbates can be detected at microscale. The paper presents an integro-partial-differential theoretical model to elucidate the effect of adsorbate viscoelasticity on vibrational properties of elastic–viscoelastic microcantilever. A differential method in the temporal domain and a variable separation method or a differential quadrature method (DQM) in the spatial domain are combined to obtain the relevant analytical solutions for free vibration with a complete adsorption and numerical solutions for forced vibration with a local adsorption. The present results agree well with the previous studies in the case of complete elastic adsorption. The study shows that the amplitude of a weakly damped free vibration of the microcantilever is positively correlated with the reciprocal of relaxation time of adsorbate film; the dissipative mechanical property of adsorption film with a standard linear solid constitutive relation endows the forced vibration of the microcantilever subjected to a transverse harmonic load with a double-peak resonance; and the sensitivity of microcantilever-based dynamic detection can be improved remarkably if the excitation frequency, film-to-substrate thickness/modulus ratio, adsorption position/area are carefully controlled.

In this paper, nitrogen incorporated ultrananocrystalline diamond (NUNCD) films were fabricated for use as electrodes to detect dopamine. The NUNCD electrodes achieved high sensitivity, great selectivity, and excellent detection limits for dopamine sensing. The NUNCD electrode, fabricated as a potential sensitive biosensor for dopamine without any catalyst or mediators, demonstrated good activity for the direct detection of dopamine by simply putting the bare NUNCD electrode into a dopamine solution. Furthermore, the marked selectivity of the NUNCD electrode is very favorable for the determination of dopamine (DA) concentration (0.32 μM) in the presence of ascorbic acid (AA) and uric acid (UA). Considering dopamine detection in real biological fluid samples, the NUNCD electrode performed excellently with a detection limit of 0.39 μM and a high recovery ranging from 90-120%, revealing that NUNCD electrodes have promising use in the sensing of dopamine.

Two coating architectures with various deposition times (Dts) for each layer and N2 gas flow rate ratio η (N2/(N2 + Ar)) of Al–N/Cr–N multilayer coatings were prepared using unbalanced magnetron reactive sputtering. Using the same coating process, two coating architectures were deposited on the high speed tool steel and Si wafer, one starting with an Al–N layer designed as the Al–N/Cr–N/…/Cr–N/Al–N (architecture A) and the other starting with a Cr–N layer designed as the Cr–N/Al–N/…/Al–N/Cr–N (architecture C). During the coating process, the N2 gas flow rate ratio η was set at 15%, 20% and 25% to control the Cr–N and Al–N layer phases. This study investigates the effects of architectures, Dt and η on the wear and hydrophobic properties of the coatings. The X-ray diffraction results show that Cr(N), Cr(N) + Cr2N and Cr2N + CrN phases respectively form in the Cr–N layer given η = 15%, 20% and 25%, and only the hcp-AlN phase forms in the Al–N layer. The layer thickness ratio (λ) of the Cr–N layer to the Al–N layer increases from 2.7 to 6.4 as η increases from 15 to 25%. The wear resistance of the coatings is strongly related to the coating architecture. The architecture A coatings exhibit better wear resistance than the architecture C coatings. The number of layers and layer thickness ratios λ also affects the wear behavior. In terms of the hydrophobic property, the coating architecture C with the Cr2N + CrN phase (η = 25%) on the top layer shows higher water contact angle measurements of 95°–97°.

We introduce a localized single-cell membrane nano-electroporation with controllable sequential molecular delivery by millisecond to nanosecond electrical pulses. An intense electrical field was generated by a pair of transparent indium tin oxide (ITO)-based nano-electrodes, which was confined to a narrow region of the single-cell membrane surface near the nano-electrode edges (approximately 2 μm × 50 nm area), whereas the remaining area of the membrane was unaffected. Moreover, a 250 nm SiO2 passivation layer on top of the nano-electrode reduced not only the thermal effect on the cell membrane surface, but it also avoided the generation of ions during the experiment, resulting in the reduction of cell toxicity and a significant enhancement of cell viability. Our approach precisely delivers dyes, Quantum Dots (QDs) and plasmids, through a localized region of single HeLa cells by considerably enhanced electrophoresis and diffusion effects with different duration of the pulsing process. The smaller molecules took less time to deliver into a single cell with a single pulse, whereas larger biomolecules took longer time even for multiple numbers of long lasting pulses. The system not only generates sequential well-controlled nano-pores allowing for the rapid recovery of cell membranes, but it also provides spatial, temporal and qualitative dosage control to deliver biomolecules into localized single-cell levels, which can be potentially beneficial for single cell studies and therapeutic applications.

Melamine sponges coated with reduced graphene oxide/carbon nanotube (rGO-CNT sponges) through a dip-coating method were fabricated that provide a large electrical conductive surface for Escherichiacoli growth and electron transfer in microbial fuel cell. Four rGO-CNT sponges with different thicknesses and arrangements were tested as an anode in this study. The thinnest one (with a thickness of 1.5mm) exhibited the best performance, providing a maximum current density of 335 A m(-3) and a remarkably durable life time of 20 days at 37 °C. Analyses of bacterial colonisation on the rGO-CNT sponges using FE-SEM and the bacterial metabolic activity using the β-galactosidase assay indicates that the rGO-CNT sponges provide excellent biocompatibility for E. coli proliferation and could help to maintain high bacterial metabolic activity, presumably due to the high mass transfer rate of the porous scaffold. In this regard, the rGO-CNT sponges showed higher durability and performed better electrochemical properties than traditional carbon-based and metal-based anodes.

In order to analysis of the mechanical properties of geogrid-reinforced granular soil, a simulation model of unconfined compression tests is proposed based on the laboratory tests conducted before by the author. This numerical method, after modified by the laboratory test data, is adopted to carry out a simulation of unconfined compression tests using large specimens of geogrid-reinforced granular soil. Each large specimen, with the diameter of 175cm and the height of 300cm, varies in reinforcement spacing of 30 cm, 37.5cm, 50 cm or 75 cm. For comparison, the same simulation test is also demonstrated for the granular soil without geogrid. A series of simulated compression stress-strain relationship curves are presented, on which a detail analysis is carried out. The following conclusions are obtained: (1) The geogrid-reinforced granular soil is a strain-hardening mass if the reinforcement spacing is less than about 50 cm. (2) While the reinforcement spacing is smaller enough, there is no sliding at the geogrid-soil interface and, therefore, the geogrid-reinforced granular soil may be taken as a composite material.

A tunable dual-band stop-band THz spectrum can be realized in a hybrid structure, which consists of metal nanoribbon arrays clad by graphene nanoribbons. Dual-band spectra can be controlled separately by the nanoribbon width w and graphene chemical potential μc. We explain that two local plasmonic modes excited at graphene ribbons belong to different gratings, which uncouple with each other by electro-magnetic shielding of the metal ribbons. Furthermore, plasmonic induced transparent (PIT) effects can also be realized by making the two transmission notches close to each other, with better performance than the PIT system based on plasmonic coupling, such as with a larger extinction radio and a tunable transparency window.

In order to study the mechanical properties of Crushed Stone-Loess (CSL), a mixture of loess and crushed stone, and Geogrid-reinforced CSL (GCSL), a series of unconfined compression tests were conducted using samples prepared respectively with CSL, GCSL, Pure Loess (PL) or Geogrid-reinforced PL (GPL). Samples varied either in the number of geogrid-reinforcement layers or in the relative compaction / in the content of crushed stone. Based on the analysis of the test results, the following conclusions are given: (1) The pattern of compressive stress-strain curves of GCSL changes gradually from obvious strain softening to strain hardening with the increase of the geogrid-reinforcement layers and the relative compaction. (2) While the compressive strain is greater than a certain value, the compressive strength of GCSL increases significantly with the increase of crushed stone content. (3) Under a larger compressive strain, the crushed stone inclusions improve apparently the compressive property of GCSL with closely spaced geogrid-reinforcement layers due to the interlocking between the crushed stone and the geogrid.

This paper reports a fabrication technology which integrates organic opto-electrowetting (OEW) with PEGDA-based microfluidics between stacked ITO glass chips for droplets generation and manipulation. Organic OEW can be realized by using titanium oxide phthalocyanine (TiOPc) as a photoconductive layer. Optical images can be projected on an organic OEW area to induce the local virtual electrodes which reduce the surface energy for actuating droplets. Low-molecular-weight (LMW) PEGDA (poly(ethylene) glycol diacrylate) material is used to form stable and biocompatible microchannels between the stacked ITO glass chips by UV photopolymerization process. PEGDA-based microfluidics provides a simpler way to enhance droplets applications in organic OEW. We demonstrate (1) the droplet formation in PEGDA microstructure, (2) the motion of droplet-in-air and droplet-in-oil operated by TiOPc OEW in this platform. This technology requires only spin-coating and UV exposure and is more cost-effective than previous methods.

Techniques to separate cells are widely applied in immunology. The technique to separate a specific antigen on a microfluidic platform involves the use of a shear horizontal surface-acoustic-wave (SH-SAW) sensor. With specific antibodies conjugated onto the surface of the SH-SAW sensors, this technique can serve to identify specific cells in bodily fluids. Jurkat cells, used as a target in this work, provide a model of cells in small abundance (1:1000) for isolation and purification with the ultimate goal of targeting even more dilute cells. T cells were separated from a mixed-cell medium on a chip (Jurkat cells/K562 cells, 1/1000). A novel microchamber was developed to capture cells during the purification, which required a large biosample. Cell detection was demonstrated through the performance of genetic identification on the chip.

The transcription factor FliA, also called sigma 28, is a major regulator of bacterial flagellar biosynthesis genes. Growing evidence suggest that in addition to motility, FliA is involved in controlling numerous bacterial behaviors, even though the underlying regulatory mechanism remains unclear. By using a transcriptional fusion to gfp that responds to cyclic (c)-di-GMP, this study revealed a higher c-di-GMP concentration in the fliA deletion mutant of Pseudomonas aeruginosa than in its wild-type strain PAO1. A comparative analysis of transcriptome profiles of P. aeruginosa PAO1 and its fliA deletion mutant revealed an altered expression of several c-di-GMP-modulating enzyme-encoding genes in the fliA deletion mutant. Moreover, the downregulation of PA4367 (bifA), a Glu-Ala-Leu motif-containing phosphodiesterase, in the fliA deletion mutant was confirmed using the β-glucuronidase reporter gene assay. FliA also altered pyocyanin and pyorubin production by modulating the c-di-GMP concentration. Complementing the fliA mutant strain with bifA restored the motility defect and pigment overproduction of the fliA mutant. Our results indicate that in addition to regulating flagellar gene transcription, FliA can modulate the c-di-GMP concentration to regulate the swarming motility and phenazine pigment production in P. aeruginosa.

A whole head finite element model for simulation of bone conducted (BC) sound transmission was developed. The geometry and structures were identified from cryosectional images of a female human head and eight different components were included in the model: cerebrospinal fluid, brain, three layers of bone, soft tissue, eye, and cartilage. The skull bone was modeled as a sandwich structure with an inner and outer layer of cortical bone and soft spongy bone (diploe) in between. The behavior of the finite element model was validated against experimental data of mechanical point impedance, vibration of the cochlear promontories, and transcranial BC sound transmission. The experimental data were obtained in both cadaver heads and live humans. The simulations showed multiple low-frequency resonances where the first was caused by rotation of the head and the second was close in frequency to average resonances obtained in cadaver heads. At higher frequencies, the simulation results of the impedance were within one standard deviation of the average experimental data. The acceleration response at the cochlear promontory was overall lower for the simulations compared with experiments but the overall tendencies were similar. Even if the current model cannot predict results in a specific individual, it can be used for understanding the characteristic of BC sound transmission in general. (C) 2016 Acoustical Society of America. Funding Agencies|European Union [600933]; Incheon Nation University (International Cooperative) Research Grant

The influences of carbon nanomaterials on bacteria were investigated using three types of dispersed and functionalized carbon nanomaterials (F-CNMs), viz. functionalized carbon nanopowder (F-CNP), functionalized single-walled carbon nanotubes (F-SWCNTs), and functionalized multi-walled carbon nanotubes (F-MWCNTs). F-CNMs with different aspect ratios were used to study the influence of material configuration on the viability of Escherichia coli ( E. coli ). Although these materials were functionalized to improve their dispersibility, the original morphologies and chemical properties of the materials were maintained. Traditional bacteria quantitative plating analysis was conducted, and the results of which revealed that the F-CNP and the F-SWCNTs showed a less significant effect on the viability of E. coli , while the F-MWCNTs obviously inhibited cell viability. A Fourier transform infrared spectroscopy and a scanning electron microscopy were used to verify the functionalization of the F-CNMs and to examine the interaction of F-CNMs with E. coli , respectively; in addition, we adopted chemiluminescence assays to measure the concentration of adenosine triphosphate (ATP) released from the damaged cells. The results showed that the ATP of the F-MWCNTs sample is two-fold higher than that of the control, indicating direct piercing of E. coli by F-MWCNTs leads to bacteria death. Furthermore, F-SWCNTs were concluded to have less influence on the viability of E. coli because ultra-long F-SWCNTs used in this study performed less rigidity to pierce the cells.

In this study, a CdSe/ZnS quantum dot (QD)-based immunosensor using a simple optical system for human serum albumin (HSA) detection is developed. Monoclonal anti-HSA (AHSA) immobilized on 3-aminopropyltriethoxysilane (APTES)-modified glass was used to capture HSA specifically. Bovine serum albumin (BSA) was used to block non-specific sites. The solution, containing AHSA–QD complex prepared by mixing biotinylated polyclonal anti-HSA and streptavidin coated QD, was used to conjugate with the HSA molecules captured on AHSA/BSA/APTES-modified glass for the modification of HSA with QD. A simple optical system, comprising a diode laser (405 nm), an optical lens, a 515-nm-long pass filter, and an Si-photodiode, was used to detect fluorescence and convert it to photocurrent. The current intensity was determined by the amount of QD specifically conjugated with HSA, and was therefore HSA-concentration-dependent and could be used to quantify HSA concentration. The detection limit of the pure QD solution was ∼3.5 × 10 −12 M, and the detection limit for the CdSe/ZnS QD-based immunosensor developed in this study was approximately 3.2 × 10 −5 mg/ml. This small optical biosensing system shows considerable potential for future applications of on-chip liver-function detection.

Many organic compounds will spontaneously disperse on the surface of a solid support to form monolayers, in a manner similar to that of inorganic salts and oxides, and numerous materials with useful properties can be designed and prepared based on this phenomenon. The dispersion behavior and orientation of organic compounds in monolayers depend not only on the molecular structure of organic compounds but also on the surface features and pore structure of the support. This short review summarizes the applications of monolayer-dispersed organic compounds in the preparation and texture control of related materials, including carbon/oxide composites, various other oxides, and mesoporous carbon with thin pore walls. Pyrolysis of organic monolayers can be used to prepare carbon/oxide composites with a uniformly thin carbon layer for use as photocatalysts, catalyst supports, and adsorbents for dyes. During the sol-gel preparation of porous oxides, organic monolayers can also prevent the aggregation of sol particles, thus producing oxides with high specific surface areas and adjustable pore volumes; γ-Al2O3 with a specific surface area as high as 506 m 2

Mesoporous carbon materials with a range of pore sizes were synthesized by a delicately controlled procedure using disordered γ-alumina as template and sucrose as carbon source. Under optimized conditions, the carbon materials had narrow pore size distribution, large surface area (>1000 m2·g-1), large pore volume (up to 3.82 cm3·g-1), high mesopore ratio (>99%), and thin pore walls with thickness of 1-2 graphene layers. In the present work, we employed three types of alumina, and investigated the correlation of their texture with that of the resultant carbon materials. A mechanism for the formation of the carbon materials was proposed and tested against experimental data. A carbon sample prepared by this method can approximately duplicate the pore structure of the template, if the carbon layer in the precursor carbon-covered alumina is complete and sufficiently robust. The mesopores of the carbons had two sources, one from the removal of the template particles and the other from the original pores of the template. Calculated pore volumes strongly support the proposed mechanism.

Negative dielectrophoretic (n-DEP) cell manipulation is an efficient way to pattern human liver cells on micro-electrode arrays. Maintaining cell viability is an important objective for this approach. This study investigates the effect of low conductivity medium and the optimally designed microchip on cell viability and cell adhesion. To explore the influence of conductivity on cell viability and cell adhesion, we have used earlier reported dielectrophoresis (DEP) buffer with a conductivity of 10.2 mS/m and three formulated media with conductivity of 9.02 (M1), 8.14 (M2), 9.55 (M3) mS/m. The earlier reported isotonic sucrose/dextrose buffer (DEP buffer) used for DEP manipulation has the drawback of poor cell adhesion and cell viability. A microchip prototype with well-defined positioning of titanium electrode arrays was designed and fabricated on a glass substrate. The gap between the radial electrodes was accurately determined to achieve good cell patterning performance. Parameters such as dimension of positioning electrode, amplitude, and frequency of voltage signal were investigated to optimize the performance of the microchip.

Industrial microdevices are mostly manufactured by micromachining technology. Materials can be micromachined by various means, including mechanical, optical and chemical. The concerns of environmental impact and production costs are the inspirations behind one alternative method of micromachining, the use of bioleaching. The evaluation of a potential microorganism for the bioleaching machining technology is conducted in the current study. The dissolution of metals by the chemolithotrophic bacteria Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans is based on the physical contact between the bacteria and their extracellular secreted metabolites and metals. Cell growth quality during the machining process is also an important issue. The specific metal removal rate is a key criterion to characterize any industrial machining process, defined here by the mass removed in milligrams from 1 cm 2 of machined area in 1 h by a solution with a cellular concentration of 1 × 108 cells/ml. The authors find that the specific metal removal rates for copper, aluminum and nickel are 0.5 mg/h, 0.06 mg/h and 0.93 mg/h, respectively.

Nanometer MgO samples with high surface area, small crystal size and mesoporous texture were synthesized by thermal decomposition of MgC2O4 · 2H2O prepared from solid-state chemical reaction between H2C2O4 · 2H2O and Mg (CH3COO)2 · 4H2O. Steam produced during the decomposition process accelerated the sintering of MgO, and MgO with surface area as high as 412 m2 · g−1 was obtained through calcining its precursor in flowing dry nitrogen at 520°C for 4 h. The samples were characterized by X-ray diffraction, N2 adsorption, transmission electron microscopy, thermogravimetry, and differential thermal analysis. The as-prepared MgO was composed of nanocrystals with a size of about 4–5 nm and formed a wormhole-like porous structure. The MgO also had good thermal stability, and its surface areas remained at 357 and 153 m2·g−1 after calcination at 600 and 800°C for 2 h, respectively. Compared with the MgO sample prepared by the precipitation method, MgO prepared by solid-state chemical reaction has uniform pore size distribution, surface area, and crystal size. The solid-state chemical method has the advantages of low cost, low pollution, and high yield, therefore it appears to be a promising method in the industrial manufacture of nanometer MgO.

Self-assembled 3-azidopropyltriethoxysilane monolayer (SAM) is used as a dielectric layer to modify the interface between the silicon dioxide wafer and the pentacene semiconductor layer in an organic thin film transistor (OTFT), Au/pentacene/3-azidopropyltriethoxysilane/SiO2/Si. Compared to the commonly used alkyl siliane C18 dielectric, 3-azidopropyltriethoxysilane which possesses stable formal charges is far more effective in increasing the ON/OFF ratio of OTFT device with an improvement of nearly three orders of magnitude. Analysis and measurements reported in this paper have illustrated for the first time the improvement of OTFT performance by a SAM compound with stable formal charges.

An ultrasensitive electrochemiluminescence (ECL) immunosensor was constructed to detect 3,3′,5–triiodothyronine (T3). The system employed T3-conjugated, silver nanoparticle-decorated carboxylic graphene oxide (Ag@fGO-T3) as a carrier and anti-T3 antibody-tris(2,2′-bipyridyl) ruthenium(II) (Ru(bpy) 3 2+ ) as a probe. The Ag@fGO-T3 and Ru(bpy) 3 2+ complex could be mobilized rapidly to the anode in the reaction chamber through electrophoresis. The fGO is reduced electrochemically at the electrode, and the electrons could transfer from an anode to the Ru(bpy) 3 2+ . The complex is excited at the electrode and an ECL signal is produced upon reacting with tripropylamine (TPrA). Because of its large surface area and excellent conductivity, Ag@fGO could enhance ECL signal significantly in the system. Quantitative measurement of T3 could be achieved in the range from 0.1 pg/mL to 0.8 ng/mLwith a detection limit of 0.05 pg/mL. In addition, the novel immunosensor showed good specificity in the presence of serum, indicating its high potential in clinical use.

Engineering functional tissues and organs in vitro is considered integral to regenerative medicine. Many recent cell patterning technique developments position cells at a pre-designated pattern to improve tissue engineering efficiency and quality and to facilitate 3-D cell-cell interaction exploration. Among these techniques, dielectrophoresis (DEP)-based cell patterning advantageously offers speed, ease of operation, low degree of cell damage, and precision. This article reviews recent advances in DEP-based patterning techniques, including electrode design, suitable buffer and hydrogel, effects of the electric current to cells, combination potential with other techniques, as well as efforts to generate 3-D tissues.

采用简单的热扩散法, MoO3可在模板纳米孔道内有序生长, 经还原后获得MoO2和金属Mo纳米管／线阵列. 运用XRD、SEM、TEM、HRTEM等技术对产物进行了表征. 结果表明: 在70 nm孔径的阳极氧化铝模板上, H2/N2气氛下600 ℃时的还原产物为单晶MoO2; 而在50 nm的模板上, 同样条件的还原产物为MoO2微晶聚合体. 乙醇的加入能够大大改善产物的形貌. H2气氛, 650 ℃以上温度下进一步还原得到了金属Mo纳米管阵列.