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Abstract Lymph node metastasis (LNM) is a typical marker in oral squamous cell carcinoma (OSCC) indicating poor prognosis. Pathological examination by artificial image acquisition and analysis, as the main diagnostic method for LNM, often takes a week or longer which may cause great anxiety of the patient and also retard timely treatment. However, there are few efficient fast LNM diagnosis methods in clinical applications currently. Our previous study profiled the proteomics of extracellular vesicles (EVs) derived from postoperative drainage fluid (PDF) and showed the potential of detecting specific EVs that expressed aspartate β-hydroxylase (ASPH) for LNM diagnosis in OSCC patients. Considering that the analysis of ASPH+ PDF-EVs is challenging due to their low abundance (counting less than 10% of total EVs in PDF) and the complex EV isolation process of ultra-centrifugation, we developed a facile platform containing two microfluidic chips filled with antibody-modified microbeads to isolate ASPH+ PDF-EVs, with both the capture and retrieval rate reaching around 90%. Clinical sample analysis based on our method revealed that a mean of 6 × 106 /mL ASPH+ PDF-EVs could be isolated from LNM+ OSCC patients compared to 2.5 × 106 /mL in LNM- OSCC ones. When combined with enzyme-linked immunosorbent assay (ELISA) technique that was commonly used in clinical laboratories in hospitals, this microfluidic platform could precisely distinguish postoperative OSCC patients with LNM or not in several hours, which were validated by a double-blind test containing 6 OSCC patients. We believe this strategy has promise for early diagnosis of LNM in postoperative OSCC patients and finally helps guiding timely and reasonable treatment in clinic.

Abstract Noninvasive prenatal diagnosis (NIPD) aims to detect fetal-related genetic disorders before birth by detecting markers in the peripheral blood of pregnant women, holding the potential in reducing the risk of fetal birth defects. Fetal-nucleated red blood cells (fNRBCs) can be used as biomarkers for NIPD, given their remarkable nature of carrying the entire genetic information of the fetus. Here, we review recent advances in NIPD technologies based on the isolation and analysis of fNRBCs. Conventional cell separation methods rely primarily on physical properties and surface antigens of fNRBCs, such as density gradient centrifugation, fluorescence-activated cell sorting, and magnetic-activated cell sorting. Due to the limitations of sensitivity and purity in Conventional methods, separation techniques based on micro-/nanomaterials have been developed as novel methods for isolating and enriching fNRBCs. We also discuss emerging methods based on microfluidic chips and nanostructured substrates for static and dynamic isolation of fNRBCs. Additionally, we introduce the identification techniques of fNRBCs and address the potential clinical diagnostic values of fNRBCs. Finally, we highlight the challenges and the future directions of fNRBCs as treatment guidelines in NIPD. Graphical Abstract

Abstract One‐step deposition approaches have been widely applied and developed in the fabrication of quasi‐2D perovskites. However, the regulation of quantum wells (QWs) and crystalline orientation is difficult and complicated when using this methodology. Sequential deposition is another widespread synthetic approach for preparing perovskite films and perovskite dimension engineering. In this article, δ‐CsPbI3 intermediate phase assisted sequential (IPAS) deposition is successfully carried out to fabricate MA‐free quasi‐2D ACI perovskites. The amount of the δ‐CsPbI3 intermediate phase in the PbI2 layer and the concentration of GAI molecule in the IPA solution both play important roles in the production of MA‐free quasi‐2D ACI perovskite films. The n value of the MA‐free quasi‐2D ACI perovskites can be adjusted, which affects the photovoltaic performance and device stability. Compared with one‐step deposition, the MA‐free quasi‐2D ACI perovskites prepared via IPAS deposition have opposite reverse‐graded QW distribution and improved vertical orientation, leading to a remarkable PEC of up to 18.86% and allowing the preparation of unpackaged devices with prominent working stability (80%, ~400 h). The underlying mechanism and crystallization pathway of IPAS deposition confirm that sequential deposition has unique superiority in regulating the QW distribution and crystalline orientation of quasi‐2D perovskites.

Abstract A series of novel Fe-Cd co-doped ZnO nanoparticle based photocatalysts are successfully synthesized by sol-gel route and characterized using scanning electron microscopy (SEM), energy dispersive X-ray emission (EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-Vis spectroscopy, X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET) techniques. The photocatalytic activity of ZnO nanoparticles doped with various atomic weight fraction of Fe and Cd has been investigated under visible light irradiation using the Methylene Blue and Rhodamine B dye in aqueous solution. The FeCd (2%):ZnO (ZFC-1) exhibit the highest photocatalytic activity in terms of rate constant as KMB = 0.01153 min−1 and KRhB = 0.00916 min−1). Further, the re-usability of the ZFC-1 photocatalyst is studied which confirms that it can be reused up to five times with nearly negligible loss of the photocatalytic efficiency. Moreover, the role of photoactive species investigated using a radical scavenger technique. The present investigations show that the doping concentration plays significant role in photocatalytic performance. The visible light absorption shown by Fe-Cd co-doped ZnO nanoparticles is much higher than that of undoped body probably due to co-doping, and the charge carrier recombination is decreased effectively which yields a higher photocatalytic performance. The mechanism for the enhancement of photocatalytic activity under visible light irradiation is also proposed.

A microfluidic droplet mixer is developed for rapid detection of Hg(II) ions. Reagent concentration and droplets can be precisely controlled by adjusting the flow rates of different fluid phases. By selecting suitable flow rates of the oil phase, probe phase and sample phase, probe droplets and sample droplets can be matched and merged in pairs and subsequently well-mixed in the poly (dimethylsiloxane) (PDMS) channels. The fluorescence enhancement probe (Rhodamine B mixed with gold nanoparticles) encapsulated in droplets can react with Hg(II) ions. The Hg(II) ion concentration in the sample droplets is adjusted from about 0 to 1000 nM through fluid regulation to simulate possible various contaminative water samples. The intensity of the emission fluorescence is sensitive to Hg(II) ions (increases as the Hg(II) ion concentration increases). Through the analysis of the acquired fluorescence images, the concentration of Hg(II) ions can be precisely detected. With the advantages of less time, cost consumption and easier manipulations, this device would have a great potential in micro-scale sample assays and real-time chemical reaction studies.

3D microelectrodes are one-step fabricated into a microfluidic droplet separator by filling conductive silver paste into PDMS microchambers. The advantages of 3D silver paste electrodes in promoting droplet sorting accuracy are systematically demonstrated by theoretical calculation, numerical simulation and experimental validation. The employment of 3D electrodes also helps to decrease the droplet sorting voltage, guaranteeing that cells encapsulated in droplets undergo chip-based sorting processes are at better metabolic status for further potential cellular assays. At last, target droplet containing single cell are selectively sorted out from others by an appropriate electric pulse. This method provides a simple and inexpensive alternative to fabricate 3D electrodes, and it is expected our 3D electrode-integrated microfluidic droplet separator platform can be widely used in single cell operation and analysis.

Methods for tagging biomolecules with fluorine 18 as immuno–positron emission tomography (immunoPET) tracers require tedious optimization of radiolabeling conditions and can consume large amounts of scarce biomolecules. We describe an improved method using a digital microfluidic droplet generation (DMDG) chip, which provides computer-controlled metering and mixing of 18 F tag, biomolecule, and buffer in defined ratios, allowing rapid scouting of reaction conditions in nanoliter volumes. The identified optimized conditions were then translated to bench-scale 18 F labeling of a cancer-specific engineered antibody fragments, enabling microPET imaging of tumors in xenografted mice at 0.5 to 4 hours postinjection.

B[a.sub.0.6]S[r.sub.0.4]Ti[O.sub.3] (BST) thin films doped by K (BSTK) from 1 to 20 mol percentage are fabricated by sol-gel method on a Pt/ Ti[O.sub.2]/Si[O.sub.2]/Si substrate. The structure and surface morphology of BST thin films are investigated as functions of K concentration by x-ray diffraction and atomic force microscopy.

The varistor-capacitor property of CaCu3Ti4O12 ceramics has been characterized by a combination of ac impedance spectroscopy and dc measurement. The results demonstrate that the non-Ohmic property and ultrahigh dielectric constant of CaCu3Ti4O12 ceramics are associated with the grain-boundary behavior. The I-V and C-V characteristics of grain-boundary regions in CaCu3Ti4O12 ceramics are explained on the basis of a back-to-back potential barrier model. We suggest that the origin of the potential barrier is related to Cu ions segregated to grain boundaries. [ABSTRACT FROM AUTHOR]

Ba0.6Sr0.4TiO3 (BST) thin films doped by K (BSTK) from 1 to 20 mol % were fabricated by sol-gel method on a Pt/TiO2/SiO2/Si substrate. Thermal evolutionary process of the Ba0.6Sr0.4TiO3 and (Ba0.6Sr0.4)0.95K0.05TiO3 dry gel was carried out by thermogravimetry and differential thermal analysis system. The structure and surface morphology of BST thin films were investigated as functions of K concentration by x-ray diffraction and atomic force microscopy. The dielectric measurements were conducted on metal-insulator-metal capacitors at the frequency from 100 Hz to 1 MHz. The K concentration in BST thin films has a strong influence on the material properties including surface morphology and dielectric and tunable properties. The grain size, surface root-mean-square roughness, dielectric constant, dissipation factor, and tunability all increased with increasing K content up to 7.5 mol % and then decreased with increasing K content from 7.5 to 20 mol % in the BSTK thin films at 1 MHz. The effects of K doping on the microstructure and dielectric and tunable properties of Ba0.6Sr0.4TiO3 thin films were analyzed. The (Ba0.6Sr0.4)92.5%K7.5%TiO3 thin film exhibited the highest dielectric constant of 1040 and the largest tunability of 73.6%. The dielectric constant, dielectric loss, and tunability of K-doped BST thin films with the optimal K content of 5 mol % were about 971, 0.023, and 69.96%, respectively. In addition, its figure of merit showed a maximum value of approximately 28.52. [ABSTRACT FROM AUTHOR]

[(Ba.sub.0.6][Sr.sub.0.4]).sub.92.5%[K.sub.7.5%]Ti[O.sub.3] (BSKT) thin films doped by Mn are fabricated by the sol-gel method on a Pt/Ti[O.sub.2]/Si[O.sub.2]/Si substrate and the structure and surface morphology of Mn-doped BSKT thin films are examined. The studies have shown that the Mn concentration in Mn doped BSKT thin films have a strong influence on material properties including surface morphology and dielectric and tunable properties.

A study was carried to examine the effect of lithium iodide concentration on the conduction behavior of poly(ethylene oxide)-poly(vinylidene fluoride) (PEO-PVDF) polymer-blend electrolyte and the corresponding performance of the dye-sensitized solar cell (DSSC). The results showed that the changes of conduction behavior and the changes of [I.sub.3.sup.-} and [I.sup.-] concentrations in the electrolytes influenced the final performance variation of the corresponding DSSC with varying LiI concentration.

The structural, electrical and optical properties of the Al doped ZnO (AZO) films deposited under different conditions by pulsed laser deposition (PLD) and the origin of these property variations are studied. The intensity of photoluminescence is correlated with the carrier concentration, indicating that the transition of electrons between conduction and valence band has dominated the room temperature emission of AZO films.

The influence of thickness on structural, electrical, and optical properties of ZnO:Al (AZO) films are investigated by depositing a set of polycrystalline AZO samples with different thickness by pulsed laser deposition. The analysis has shown that photoluminescence spectra of AZO films are fitted well by seven emissions and the emission around 2.82 eV can be assigned to N-deep-level related recombination.

A combination of ac impedance spectroscopy and dc measurement is used to characterize the varistor-capacitor property of Ca[Cu.sub.3][Ti.sub.4][O.sub.12] ceramics. The results have shown that the non-Ohmic property and ultrahigh dielectric constant of Ca[Cu.sub.3][Ti.sub.4][O.sub.12] ceramics are associated with the grain-boundary behavior.

We report on the feasible fabrication of microfluidic devices for ferroelectric polymers' synthesis in a rapid and stable fashion. Utilizing micro-mixing and flowfocusing in microchannels, poly(vinylidene fluoride-trifluoroethylene) and copper phthalocyanine are uniformly dispersed in one hydrogel particle, which are then demonstrated to immediate and complete on-chip steady polymerization by moderate ultraviolet treatment. The advantage of our droplet-based microfluidic devices is generating versatile particles from simple spheres to disks or rods, and the lengths of particles can be precisely tuned from 30 to 400 μm through adjusting the flow rates of both disperse and oil phases. In addition, this mixed technique allows for the continuous production of dielectric microparticles with controlled dielectric properties between 10 and 160. Such a microfluidic device offers a flexible platform for multiferroic applications. [ABSTRACT FROM AUTHOR]

Aiming to synthesize multiferroic materials in microscale, a microfluidic device capable of generating multiferroic Janus microparticles is demonstrated. Through bonding two polydimethylsiloxane (PDMS) layers "face to face," laminar flow containing an upper layer and a lower layer can be realized. Accordingly, poly(vinylidene fluoride-trifluoroethylene) ferroelectric polymers and Fe3O4 ferromagnetic particles are separately encapsulated in the two layers of a single droplet. Numerical simulation enables the analysis of cross-mixing between the two counterparts and helps to find an optimized location for adding subsequent ultraviolet treatment, which will polymerize the droplets into Janus particles without any side effect. By modulation of the flow rate, the size of the Janus particles can be precisely tuned. Finally, the ferroelectricity and magnetism of the Janus particles are verified by the magnetization and polarization measurements, indicating the multiferroic nature. [ABSTRACT FROM AUTHOR]

A microfluidic droplet mixer is developed for rapid detection of Hg(II) ions. Reagent concentration and droplets can be precisely controlled by adjusting the flow rates of different fluid phases. By selecting suitable flow rates of the oil phase, probe phase and sample phase, probe droplets and sample droplets can be matched and merged in pairs and subsequently well-mixed in the poly (dimethylsiloxane) (PDMS) channels. The fluorescence enhancement probe (Rhodamine B mixed with gold nanoparticles) encapsulated in droplets can react with Hg(II) ions. The Hg(II) ion concentration in the sample droplets is adjusted from about 0 to 1000 nM through fluid regulation to simulate possible various contaminative water samples. The intensity of the emission fluorescence is sensitive to Hg(II) ions (increases as the Hg(II) ion concentration increases). Through the analysis of the acquired fluorescence images, the concentration of Hg(II) ions can be precisely detected. With the advantages of less time, cost consumption and easier manipulations, this device would have a great potential in micro-scale sample assays and real-time chemical reaction studies. [ABSTRACT FROM AUTHOR]

This paper introduces a cancer cell capture/release microchip based on the self-sacrificed MnO2 nanofibers. Through electrospinning, lift-off and soft-lithography procedures, MnO2 nanofibers are tactfully fabricated in microchannels to implement enrichment and release of cancer cells in liquid samples. The MnO2 nanofiber net which mimics the extra cellular matrix can lead to high capture ability with the help of a cancer cell-specific antibody bio-conjugation. Subsequently, an effective and friendly release method is carried out by using low concentration of oxalic acid to dissolve the MnO2 nanofiber substrate while keeping high viability of those released cancer cells at the same time. It is conceivable that our microchip may have potentials in realizing biomedical analysis of circulating tumor cells for biological and clinical researches in oncology. [ABSTRACT FROM AUTHOR]

A piezoelectric nanogenerator with self-amplified output is prepared with a polydimethylsiloxane (PDMS)/silver nanowire (Ag NW)/poly(vinylidene fluoride-trifluoroethylene) sandwich structure. The Ag NWs facilitate the collection of induced charge generated by the piezoelectric film, and the micro-patterned PDMS films multiply the devices sensitivity under external compression. The nanogenerator exhibits good performance, with a peak open circuit voltage of 1.2 V, and a peak short circuit current of 82 nA. These findings highlight the potential of the nanogenerator in selfpowered devices and wearable energy harvesters. [ABSTRACT FROM AUTHOR]

We report on the feasible generation of BiFeO3-Fe3O4 Janus particles (JPs) based on droplet microfluidic method. Utilizing laminar flow and flow-focusing in microchannels, BiFeO3 and Fe3O4 nanoparticles were separately embedded in each hemisphere of one hydrogel particle. The size of the Janus particles showed favorable uniformity at micron scale and could be precisely controlled by flow rate regulation. The magnetism and ferroelectricity of the JPs were confirmed by magnetization and polarization measurements, indicating potential in multiferroic applications. [ABSTRACT FROM AUTHOR]

A highly environmentally-friendly ubiquinone 10 (UQ10) based I2-free electrolyte, which is inspired by photosynthesis, is employed in dye-sensitized solar cells (DSSCs) under 100 mW cm-2 (AM 1.5G) illumination. Profiting from this UQ10 based electrolyte a 10% increased power conversion efficiency of 8.18% is achieved compared with the traditional one containing I2 (7.44%). The superior performance of this UQ10 based electrolyte is mainly derived from the lower visible light wastage and high catalytic activity to the counter electrode as revealed by photoelectrochemical characterization. Moreover, being widely adopted in cardiovascular medicine and cosmetics, UQ10 is a very safe and low-cost choice for DSSCs. With the advantages of high power conversion efficiency, bio-safety, universal dye compatibility and diversity of molecular design, UQ10 is very promising to be widely applied in DSSCs, and perovskite based solar cells. [ABSTRACT FROM AUTHOR]

In this paper, we demonstrate a new type of microfluidic chip that can realize continuous-flow purification of hydrogel beads from a carrier oil into aqueous solution by using a laminar-like oil/water interface. The microfluidic chip is composed by two functional components: (1) a flow-focusing bead generation module that can control size and shape of beads, (2) a bead extraction module capable of purifying hydrogel beads from oil into aqueous solution. This module is featured with large branch channels on one side and small ones on the opposite side. Water is continuously infused into the bead extraction module through the large branch channels, resulting in a laminar-like oil/water interface between the branch junctions. Simulation and experimental data show that the efficiency of oil depletion is determined by the relative flow rates between infused water and carrier oil. By using such a microfluidic device, viable cells (HCT116, colon cancer cell line) can be encapsulated in the hydrogel beads and purified into a cell culture media. Significantly improved cell viability was achieved compared to that observed by conventional bead purification approaches. This facile microfluidic chip could be a promising candidate for sample treatment in lab-on-a-chip applications. [ABSTRACT FROM AUTHOR]

In this paper we describe a versatile microfluidic strategy for simultaneous preparation of quantum dot-encoded microbeads with controllable barcodes. This method involves the generation of multiple dispersed solutions carrying stepwise concentration gradients of quantum dots by using a pyramidal microfluidic network, the formation of corresponding droplets in parallel flow-focusing droplet generators, and on-chip solidification of these droplets into microbeads. Using a designed microfluidic device, we simultaneously generated five kinds of fluorescence-encoded alginate hydrogel microbeads with a five-level stepwise concentration gradient of monochromatic quantum dot or five controllable ratios of two different-sized quantum dots. This method has the following features: (1) the barcode adapter compartment substitutes the respective preparation of precursor solutions containing the correct concentrations and ratios of different quantum dots for corresponding barcodes. (2) Identical microbeads with distinct quantum dot barcodes can be simultaneously generated in homogeneous conditions. (3) The microfluidic device can be upgraded by increasing or decreasing the inlets and outlets of the pyramidal network and the number of the parallel flow-focusing droplet generators to meet the requirements for the particular barcodes. We expect that this microfluidic route will facilitate the construction and mass-production of robust and reproducible barcode materials. [ABSTRACT FROM AUTHOR]

Optical barcoding technology based on quantum dot (QD)-encoded microparticles has attracted increasing attention in high-throughput multiplexed biological assays, which is realized by embedding different-sized QDs into polymeric matrixes at precisely controlled ratios. Considering the advantage of droplet-based microfluidics, producing monodisperse particles with precise control over the size, shape and composition, we present a proof-of-concept approach for on-demand preparation of QD-encoded microparticles based on this versatile new strategy. Combining a flow-focusing microchannel with a double T-junction in a microfluidic chip, biocompatible QD-doped microparticles were constructed by shearing sodium alginate solution into microdroplets and on-chip gelating these droplets into a hydrogel matrix to encapsulate CdSe/ZnS QDs. Size-controllable QD-doped hydrogel microparticles were produced under the optimum flow conditions, and their fluorescent properties were investigated. A novel multiplex optical encoding strategy was realized by loading different sized QDs into a single droplet (and thus a hydrogel microparticle) with different concentrations, which was triggered by tuning the flow rates of the sodium alginate solutions entrapped with different-colored QDs. A series of QD-encoded microparticles were controllably, and continuously, produced in a single step with the present approach. Their application in a model immunoassay demonstrated the potential practicability of QD-encoded hydrogel microparticles in multiplexed biomolecular detection. This simple and robust strategy should be further improved and practically used in making barcode microparticles with various polymer matrixes. [ABSTRACT FROM AUTHOR]

A sandwich structure with fractal pattern for microstrip line is proposed, in which a fractal pattern consisting of “H” is etched in the plane between the microstrip line and the ground plane of microstrip line. The transmission characteristics of that sandwich structure appear to have the multiple gaps and pass bands of electromagnetic waves is from 40 MHz to 10 GHz, and in particular the use of the fractal patterns array is increasing the gaps property of the gaps and pass bands. In this article, the transmission characteristics of one microstrip line with the sandwich structure normalized by 50 Ω are directly calculated by the finite different time domain (FDTD) method. Experimental observations are in good agreement with the result of FDTD simulations. Microstrip transmission lines incorporating a sandwich structure with fractal patterns exhibit band-stops and slow-wave characteristics, which can be exploited to reject unwanted frequency and to reduce the dimensions of the microstrip structure. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1714–1717, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21756 [ABSTRACT FROM AUTHOR]

A new-style, piezocomposite cymbal transducer is presented in this paper. The single cymbal element is packaged in an ultra-high frequency (UHF) connector and sealed with epoxy, plugged by a coaxial-cable, which is more portable and miniature compared with conventional ones. Several kinds of cap heights are designed and the theory model of class V flextensional transducer is used to study their performance based on the cavity depth and caps thickness. The effect of dimensional changes on fundamental resonant frequencies has been investigated by finite element analysis. It is found that the cymbal transducer exhibits large displacement amplification, fast response time and high effective coupling factor through theoretical calculation, which are coincident with measurements. The results show that this design would have more potential application of low frequency and high energy transmission. [ABSTRACT FROM AUTHOR]

A simple and effective droplet electric separator microfluidic device was developed for cell sorting. The aqueous droplet without precharging operation was influenced to move a distance in the channel along the electric field direction by applying dc voltage on the electrodes beside the channel, which made the target droplet flowing to the collector. Single droplet can be isolated in a sorting rate of ∼100 Hz with microelectrodes under a required pulse. Single or multiple mammalian cell (HePG2) encapsulated in the surfactant free alginate droplet could be sorted out respectively. This method may be used for single cell operation or analysis. [ABSTRACT FROM AUTHOR]

Nanomotors represent a significant step forward in nanotechnology, and prove that nanotubes and other nanostructures several hundred times smaller than the diameter of a human hair can be manipulated and assembled into true devices. In this letter, nanotubes based nanomotors are reported. The nanomotors were observed to move at a velocity of ∼0.5 m/s, which is several orders of magnitude faster than current nanomotors. Concentration difference energy was thought to provide the main motive forces to drive these nanomotors. This phenomenon which is seldom observed at macroscopic scale, is common in microscale, and can be employed to explain some motions of nano- and microscale objects. [ABSTRACT FROM AUTHOR]

The sequential resonant tunneling in La0.5Sr0.5CoO3-δ (LSCO) semiconductor quantum dots (QDs) arrays were observed by current-voltage measurements under room temperature. A series of spikelike current peaks are found, which are resulted from the accumulation and depletion of electrons tunneling through the QDs embedded in insulated barriers. Temperature dependent onset-voltage blueshift and number variation in current peaks are also observed. These results confirm the size-induced metal-to-semiconductor transition in LSCO. [ABSTRACT FROM AUTHOR]

A surface modification method was carried out by rf magnetron sputtering to fabricate ZnO-coated TiO2 electrodes (TiO2/ZnO) for improving the performance of dye-sensitized solar cells. The TiO2/ZnO electrodes had been characterized by x-ray photoelectron spectroscopy, scanning electron microscopy, UV-visible spectrophotometer, and electrochemical impedance spectroscopy. The study results revealed that the TiO2 modification suppresses interfacial recombination. Sputtering ZnO for 3 min on 5 μm TiO2 greatly improves all cell parameters, resulting in increasing efficiency from 4.76% to 6.55%. [ABSTRACT FROM AUTHOR]

(Pb0.25Ba0.15Sr0.6)TiO3 (PBST) nanotube arrays were prepared using porous anodic aluminum oxide (AAO) template from PBST sol solution. Electron microscope results showed that uniform length and diameter of PBST nanotubes were obtained and that the diameter and length of PBST nanotubes were dependent on the pore diameter and the thickness of the applied AAO template. X-ray diffraction and electron diffraction pattern investigations demonstrated that PBST nanotubes were composed of perovskite nanocrystals. Comparison between nanotube and nanofilm polarization results showed that enhanced polarization existed in PBST nanotubes. A mechanism has been proposed to explain this polarization enhancement effect. [ABSTRACT FROM AUTHOR]

(Li1/2Nd1/2)2+ substitution into the A site and (Mg1/3Ta2/3)4+ substitution into the B site of CaTiO3 ceramic were investigated, respectively. The modified CaTiO3 dielectric ceramics prepared by conventional solid-state method exhibit single perovskite structure and improved dielectric properties. Optimal microwave dielectric properties of ℇr=112.6, Q× f=4480 GHz, τf=8.2 ppm/°C in [Ca0.4(Li1/2Nd1/2)0.6] TiO3 and ℇr=60.2, Q× f=36900 GHz, τf=−10.1 ppm/°C in Ca[Ti0.4(Mg1/3Ta2/3)0.6] O3 are obtained, which indicates their potential for microwave application. The effects of change of crystal structure on dielectric properties are also discussed. [ABSTRACT FROM AUTHOR]

Effect of proton irradiation on poly(vinylidene fluoride-trifluoroethylene) 56/44 mol % copolymer has been studied using a Mach–Zehnder heterodyne interferometer, polarization hysteresis loop and dielectric constant measurements. The electrical-field-induced strain response of the copolymer after proton bombardment follows a quadratic electrostriction relationship. The electrostrictive coefficient at 5 kHz is similar to that obtained with a bimorph-based strain sensor, but at a much lower electric field. The polarization hysteresis after proton irradiation is reduced considerably and the dielectric constant exhibits typical relaxor behavior, which is suggested as the cause of the observed results. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Circulating tumor cells (CTCs) are important for the detection and treatment of cancer. Nevertheless, a low density of circulating tumor cells makes the capture and release of CTCs an obstacle. In this work, TiO2 nanopillar arrays coated with gelatin film were synthesized for efficient capture and undamaged release of circulating tumor cells. The scanning electron microscope and atomic force microscope images demonstrate that the substrate has a certain roughness. The interaction between the cell membrane and the nanostructure substrate contributes to the efficient capture of CTC (capture efficiency up to 94.98%). The gelatin layer has excellent biocompatibility and can be rapidly digested by matrix metalloproteinase (MMP9), which realizes the non-destructive release of CTCs (0.1 mg ml−1, 5 min, nearly 100% release efficiency, activity 100%). Therefore, by our strategy, the CTCs can be efficiently captured and released undamaged, which is important for subsequent analysis. [ABSTRACT FROM AUTHOR]

Non-invasive prenatal diagnostics (NIPD) has been an emerging field for prenatal diagnosis research. Carrying the whole genome coding of the fetus, fetal nucleated red blood cells (FNRBCs) have been pursued as a surrogate biomarker traveling around in maternal blood. Here, by combining a unique microbead-based centrifugal separation and enzymatic release, we demonstrated a novel method for FNRBC isolation from the blood samples. First, the gelatin-coated silica microbeads were modified with FNRBC-specific antibody (anti-CD147) to capture the target cells in the blood samples. Then, the density difference between microbead-bound FNRBCs and normal blood cells enables the purification of FNRBCs via an improved high-density percoll-based separation. The non-invasive release of FNRBCs can then be achieved by enzymatically degrading the gelatin film on the surface of the microbeads, allowing a gentle release of the captured target cells with as high as 84% efficiency and ∼80% purity. We further applied it to isolate fetal cells from maternal peripheral blood. The released cells were analyzed by real-time polymerase chain reaction to verify their fetal origin and fluorescent in situ hybridization to detect fetal chromosome disorders. This straightforward and reliable alternative platform for FNRBC detection may have the potential for realizing facile NIPD. [ABSTRACT FROM AUTHOR]

Nanotechnology possesses the potential to revolutionize the diagnosis and treatment of tumors. The ideal nanoparticles used for in vivo cancer therapy should have long blood circulation times and active cancer targeting. Additionally, they should be harmless and invisible to the immune system. Here, we developed a biomimetic nanoplatform with the above properties for cancer therapy. Macrophage membranes were reconstructed into vesicles and then coated onto magnetic iron oxide nanoparticles (Fe3O4 NPs). Inherited from the Fe3O4 core and the macrophage membrane shell, the resulting Fe3O4@MM NPs exhibited good biocompatibility, immune evasion, cancer targeting and light-to-heat conversion capabilities. Due to the favorable in vitro and in vivo properties, biomimetic Fe3O4@MM NPs were further used for highly effective photothermal therapy of breast cancer in nude mice. Surface modification of synthetic nanomaterials with biomimetic cell membranes exemplifies a novel strategy for designing an ideal nanoplatform for translational medicine. [ABSTRACT FROM AUTHOR]