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Summary The natural selection of ribose as the exclusive sugar for RNA has been one of the greatest puzzles in the origins of life. Here, we present a plausible solution to this problem that circumvents the limitations of previous hypotheses, inspired by the unique retention properties of ribose in ligand-exchange chromatography. It is discovered that metal cations and clay minerals have a synergistic effect to selectively bind to ribose against other monosaccharides. Excitingly, ribose can be continuously and highly selectively enriched on metal-doped-clays (MDCs) from a complex Formose mixture, which could be the origin of its rise to prominence. Prebiotic scenarios of the dynamic isolation of ribose from sugar mixture are simulated with microflow technology. The MDC-retained ribose exhibits long-term stability for the upcoming nucleosidation reactions. Computational studies help elucidate the unique stability of the ribose-MDC complex. MDC also promotes the 5′-phosphorylation of nucleosides with greater yield and selectivity than reported.

Clinical evidence has established that concomitant traumatic brain injury (TBI) accelerates bone healing, but the underlying mechanism is unclear. This study shows that after TBI, injured neurons, mainly those in the hippocampus, release osteogenic microRNA (miRNA)-enriched small extracellular vesicles (sEVs), which targeted osteoprogenitors in bone to stimulate bone formation. We show that miR-328a-3p and miR-150-5p, enriched in the sEVs after TBI, promote osteogenesis by directly targeting the 3′UTR of FOXO4 or CBL, respectively, and hydrogel carrying miR-328a-3p-containing sEVs efficiently repaires bone defects in rats. Importantly, increased fibronectin expression on sEVs surface contributes to targeting of osteoprogenitors in bone by TBI sEVs, thereby implying that modification of the sEVs surface fibronectin could be used in bone-targeted drug delivery. Together, our work unveils a role of central regulation in bone formation and a clear link between injured neurons and osteogenitors, both in animals and clinical settings., Concomitant traumatic brain injury accelerates bone healing, but the mechanism is unclear. Here, the authors show that injured neurons, mainly those in the hippocampus, release osteogenic miRNA-enriched small extracellular vesicles, which targete osteoprogenitors to stimulate bone formation.

Two-dimensional (2D) tellurium (Te) has drawn extensive interest for its intriguing properties, such as p-type conduction, high mobility, environmental stability, and field effects. Here, we employ...

The insensitive ignitors with magnesium/tellurium dioxide (Mg/TeO2) priming composition installed on the spacecraft will experience a harsh thermal environment. Therefore, it is necessary to verify their availability at extreme temperatures. Differential Scanning Calorimetry and Thermogravimetric Analysis (DSC-TGA) were used to analyze the reaction process of the Mg/TeO2 priming composition. The morphology change of the Mg/TeO2 priming composition after -70 ℃6d, room temperature, 165 ℃6d were analyze by digital cameras, scanning electron microscope (SEM), as well as the output pressure, ignition time, function time and firing sensitivity of the Mg/TeO2 priming composition under three temperature conditions were tested. The results show that in a temperature range of -70 ℃ ~ 165 ℃, the temperature conditions have an effect on the output pressure less than 5%, the influence of high temperature conditions on ignition/ function time and sensitivity is greater than low temperature. It can be used as a priming composition for insensitive ignitors at -70 ℃ ~ 165 ℃.

A continuous-flow photocatalytic synthesis of the industrially important thiuram disulfides has been developed, utilizing O2 as the oxidant and Eosin Y as the photoredox catalyst. This highly atom- and step-economical method features much reduced reaction time as well as excellent product yield and purity, making it a sustainable and potentially scalable process for industrial production.

Here, we report the fabrication of TiO2/Fe2O3 core/shell heterojunction nanorod arrays by a pulsed laser deposition (PLD) process and their further use as photoelectrodes toward high-performance visible light photoelectrochemical (PEC) water splitting. The morphology, phase, and carrier conduction mechanism of plain TiO2 and TiO2/Fe2O3 core/shell nanostructure were systematically investigated. PEC measurements show that the TiO2/Fe2O3 core/shell nanostructure enhances photocurrent density by nearly 2 times than the plain ones, increases visible light absorption from 400 to 550 nm, raises the on/off separation rate, and delivers high stability with only a 3% decrease of current density for tests of even more than 14 days. This work provides a method to design an efficient nanostructure by combination of a facile hydrothermal process and high-quality PLD process to fabricate a clean surface and excellent crystallinity for charge separation, transfer, and collection toward enhanced PEC properties.

Removal of trace chlorobutane (CB) isomers is highly desired to produce high grade 1-chlorobutane (1-CB) and 2-chlorobutane (2-CB). Here, we report that nonporous adaptive crystals (NACs) of perethylated pillar[5]arene (EtP5) and pillar[6]arene (EtP6) effectively remove trace CB isomers. EtP5 NACs can remove trace 1-CB (2%) from 2-CB to improve its purity from 98.0% to 99.9%, while EtP6 NACs can remove trace 2-CB from 1-CB to improve its purity from 98.0% to 99.9%. The adsorption of trace CB isomers results in the formation of new CB-loaded crystal structures, whose thermostability is higher than their corresponding isomer-loaded structures. This determines the selectivity of NACs toward the trace CB isomers. Reversible transformations between nonporous guest-free and guest-loaded structures make EtP5 and EtP6 highly recyclable.

Two monochloropyridine isomers, 2-chloropyridine (2-CP) and 3-chloropyridine (3-CP), are in need of a more effective separation method besides rectification. Herein we offer a facile and energy-sav...

Background Tourette syndrome (TS) is a common childhood disorder characterized by unwanted movements or vocal sounds called tics. It is often accompanied by other psychobehavioral disorders, including fearful behavior. The establishment and evaluation of rat models of TS and comorbid fear can provide an experimental basis for the treatment of TS and its comorbid fear disorder. Methods Sixteen rats were randomly divided into a model group (n=8) and control group (n=8). In the model group, rats were injected intraperitoneally with iminodipropionitrile (IDPN) for 1 week to establish the TS model, which was followed by acoustic and electrical stimulation for 3 weeks to establish the rat models of TS and comorbid fear. The control group received intraperitoneal injection of saline for 1 week, and no further intervention was given in the last 3 weeks. The behavioral changes of the rats were observed and analyzed by the open field test (OFT). Protein kinase A (PKA), cyclic adenosine monophosphate (cAMP), and dopamine (DA) were measured by enzyme-linked immunosorbent assay (ELISA), and tyrosine hydroxylase (TH) and microRNA-134 (miRNA-134) in the brain tissue were detected by using polymerase chain reaction (PCR). Results One rat in the model group died on the 24th day. Compared with the control group, the model group had significantly higher scores of locomotor activity, stereotyped behavior, and motor behavior, along with prolonged freezing time and significantly lower expression of miRNA-134. The differences in the expressions of PKA, cAMP, DA, and TH in brain tissue were not statistically significant. Conclusions The rat models of TS and comorbid fear have similar changes in behaviors and miRNA-134 level to those in clinical settings and therefore can be used as a reliable animal model to study the mechanism of action of TS and comorbid fear.

Dairy farm slurry is an important biomass resource that can be used as a fertilizer and in energy utilization and chemical production. This study aimed to establish an innovative ultrasound-assisted electrochemical oxidation (UAEO) digestion method for the rapid and onsite analysis of the heavy metal (HM) contamination level of dairy slurry. The effects of UAEO operating parameters on digestion efficiency were tested based on Cu and Zn concentrations in a dairy slurry sample. The results showed that Cu and Zn digestion efficiency was (96.8 ± 2.6) and (98.5 ± 2.9)%, respectively, with the optimal UAEO operating parameters (digestion time: 45 min, ultrasonic power: 400 W, NaCl concentration: 10 g/L). The digestion recovery rate experiments were then operated with spiked samples to verify the digestion effect on broad-spectrum HMs. When the digestion time reached 45 min, all digestion recovery rates exceeded 90%. Meanwhile, free chlorine concentration, particle size distribution, and micromorphology were investigated to demonstrate the digestion mechanism. It was found that 414 mg/L free chorine had theoretically enough oxidative ability, and the ultrasound intervention could deal with the blocky undissolved particles attributed to its crushing capacity. The results of particle size distribution showed that the total volume and bulky particle proportion had an obvious decline. The micromorphology demonstrated that the ultrasound intervention fragmented the bulky particles, and electrochemical oxidation made irregular blocky structures form arc edge and cellular structures. The aforementioned results indicated that UAEO was a novel and efficient method. It was fast and convenient. Additionally, it ensured digestion efficiency and thus had a good application prospect.

Researchers have put significant efforts on developing versatile fluorescent polymeric systems due to their promising biological/biomedical labelling, tracking, monitoring, imaging, and diagnostic applications. However, complicated organic/polymeric synthesis or post-modification of these functionalized platforms is still a big obstacle for their further application and thereby provides clear motivation for exploring alternative strategies for the design and fabrication of easily available fluorescent systems. The marriage of supramolecular polymers and fluorescent imaging can provide a facile and dynamic manner instead of tedious and time-consuming synthesis due to the dynamic and reversible nature of noncovalent interactions. Herein, based on water-soluble pillararene/paraquat molecular recognition, we successfully prepare two amphiphilic polypseudorotaxanes which can self-assemble into supramolecular polymersomes in water. These polymersomes can be reversibly destroyed and reformed by tuning the solution pH. Attributed to the aggregation-induced emission of tetraphenylethylene groups, intense fluorescence can be introduced into the obtained supramolecular polymersomes. Furthermore, pH-triggered release of an encapsulated water-insoluble drug (doxorubicin) from the self-assembled fluorescent supramolecular polymersomes is also investigated.\ud \ud

The separation of haloalkene cis–trans isomers is difficult to achieve, yet highly desired in the chemical industry. Here, we report an energy-efficient adsorptive separation of 1,4-dichloro-2-bute...

Perovskite oxide SrVO3 (SVO) is a transparent conductor with excellent optical and electrical properties. Most of the previous works have focused on (001)-oriented SVO thin films. As an alternative to tin-doped indium oxide (ITO), the other orientations of SVO thin films are important to be considered as well. In the present work, the optical and electrical properties of (111)-oriented SVO epitaxial films have been investigated. Excellent electrical conductivity (2.92 × 104 S cm−1) and optical transparency (56.6%) have been demonstrated, which are comparable to those of ITO and expand the applications of epitaxial SVO thin films in other orientations as transparent conducting oxide.

The incorporation of supramolecular macrocycles into porous organic polymers may endow the material with enhanced uptake of specific guests through host−guest interactions. Here we report a solvent and catalyst-free mechanochemical synthesis of pillar[5]quinone (P5Q) derived multi-microporous organic polymers with hydrophenazine linkages (MHP-P5Q), which show a unique 3-step N2 adsorption isotherm. In comparison with analogous microporous hydrophenazine-linked organic polymers (MHPs) obtained using simple twofold benzoquinones, MHP-P5Q is demonstrated to have a superior performance in radioactive iodomethane (CH3I) capture and storage. Mechanistic studies show that the rigid pillar[5]arene cavity has additional binding sites though host−guest interactions as well as the halogen bond (−I⋯N = C−) and chemical adsorption in the multi-microporous MHP-P5Q mainly account for the rapid and high-capacity adsorption and long-term storage of CH3I., Incorporation of supramolecular macrocycles into porous organic polymers can increase uptake of guest molecules through host−guest interactions. Here the authors report a pillar[5]quinone derived multi-microporous organic polymer, which show a superior performance in radioactive iodomethane capture and storage.

Transparent conducting oxides (TCOs), such as indium-tin oxide (ITO) and indium gallium zinc oxide (IGZO), are essential components in the design of flexible optoelectronic devices. However, it is still a challenge to prepare low-cost flexible transparent conductive film for achieving the flexible functionality together with high optical transparency and electrical conductivity. Herein, fluorphlogopite (mica) is selected as the bendable and transparent substrate for the fabrication of low-cost perovskite CaVO3 TCO epitaxial film. Benefitting from thin mica substrate with high Young’s modulus of 200 GPa, flexible CaVO3 TCO epitaxial film exhibits high mechanical stability in terms of electrical conductivity and optical transparency after bending up to 105 cycles. The change of resistance can reflect the bending curvature and strain state. Our results provide a new pathway to design superior mechanical flexibility and stability CaVO3 TCO films for application in flexible, light-weight, and portable smart optoelectronic devices.

Postsynthetic modification in crystalline solids without disruption of crystallinity is very important for exerting control that is unattainable over chemical transformation in solution. This has been achieved in porous crystalline frameworks via solid-solution reactions to endow them with multiple functions. However, this is rather rare in nonporous molecular crystals, especially via solid-vapor reactions. Herein, we report unique solid-vapor postsynthetic modification of nonporous adaptive crystals (NACs) of a pillar[4]arene[1]quinone (EtP4Q1) containing four inert 1,4-diethoxybenzene units and one active benzoquinone unit. Amine vapors that can be physically adsorbed by EtP4Q1 NACs react with the EtP4Q1 backbone via Michael addition with in situ formation of new crystal structures. First, amines are physically adsorbed into cavities of EtP4Q1 molecules and slowly react due to their juxtapsition with the benzoquinone units. Amines that are too bulky to enter EtP4Q1 NACs do not react. Moreover, the process displays both reactant-size and -shape selectivities because of the rigid cavity of EtP4Q1 and the different binding strengths of various amines with EtP4Q1.

The separation of cyclic aliphatics of high purity, which are produced from hydrogenation of the corresponding aromatics, is highly desired in the chemical industry. An energy-efficient and environmentally friendly adsorptive separation method using nonporous adaptive crystals of perethylated pillar[5]arene (EtP5) and pillar[6]arene (EtP6) is described. Adaptive EtP5 crystals separate toluene from methylcyclohexane with 98.8 % purity, while adaptive EtP6 crystals separate methylcyclohexane from toluene with 99.2 % purity. The selectivities come from the stability of new EtP5 and EtP6 crystal structures upon capture of toluene and methylcyclohexane, respectively. The reversible transformations between nonporous guest-free EtP5 or EtP6 structures and guest-loaded structures make them highly recyclable.

A CO2-enhanced bola-type supramolecular amphiphile was constructed from a water-soluble pillar[5]arene and a CO2-responsive bola-amphiphile. The gas-responsive self-assembly behavior of this supramolecular amphiphile and its application in controlled release were investigated.

Here we report the synthesis of a novel, easily available and rigid acyclic C-shaped host−−clip[4]arene. It has the ability to bind electron-poor pyridinum salts in solution. A bipyridinum salt, paraquat, is found to have a 1:1 complexation stoichiometry in acetone but a 2:1 complexation stoichiometry in the solid state with clip[4]arene. Unlike traditional [2]pseudorotaxanes with structures of linear guest molecules threaded into macrocyclic hosts, the complex of clip[4]arene and paraquat is rather a [2]pseudoclipaxane where a linear molecule is threaded through a rigid acyclic C-shaped molecule. Furthermore, the complexation between clip[4]arene and paraquat is redox-controlled and can be reversibly regulated through the sequential addition of Zn powder and exposure to air.

Here we show a new adsorptive separation approach using nonporous adaptive crystals of a pillar[5]arene. Desolvated perethylated pillar[5]arene crystals (EtP5α) with a nonporous character selectively adsorb 1-pentene (1-Pe) over its positional isomer 2-pentene (2-Pe), leading to a structural change from EtP5α to 1-Pe loaded structure (1-Pe@EtP5). The purity of 1-Pe reaches 98.7% in just one cycle and EtP5α can be reused without losing separation performance.

Here we report that easily obtained per-ethylated pillar[6]arene (EtP6) is a new adsorbent for iodine capture with high chemical and thermal stability. Nonporous EtP6 solids are shown to capture not only volatile iodine in the air but also iodine dissolved in an organic solvent and aqueous solution. Uptake of iodine leads to a structural transformation of EtP6 in the solid state. In the single crystal structure of iodine-doped EtP6 (I2@EtP6), each adsorbed iodine molecule is located between two adjacent EtP6 molecules to form a linear supramolecular polymer. Iodine is released spontaneously from I2@EtP6 solids when they are immersed in cyclohexane. These EtP6 solids can be reused many times without losing iodine capture capacity.

The removal of soluble cyclic ether contaminants, such as dioxane and THF, produced in industrial chemical processes from water is of great importance for environmental protection and human health. Here we report that nonporous adaptive crystals of perethylated pillar [ 5 ] arene ( EtP5 ) and pillar [ 6 ] arene ( EtP6 ) work as adsorbents for cyclic ether contaminant removal via host-guest complexation at the solid-solution interface. Nonporous EtP6 crystals have the ability to adsorb dioxane from water with the formation of 1:2 host-guest complex crystals, while EtP5 crystals cannot. However, both guest-free EtP5 and EtP6 crystals remove THF from water with EtP5 having a better capacity. This is because EtP5 forms a 1:2 host-guest complex with THF via host-guest complexation at the solid-solution interface while EtP6 forms a 1:1 host-guest complex with THF. EtP6 also shows the ability to selectively remove dioxane from water even in the presence of THF. Moreover, the reversible transitions between nonporous guest-free EtP5 and EtP6 structures and guest-loaded structures make them highly recyclable.

Summary For the RNA world hypothesis, the direct condensation between nucleobase and ribose to afford canonical nucleoside has been a formidable challenge in terms of regioselectivity. In this report, we demonstrate that cavitation, a frequently occurring energy-intensive phenomenon upon the collapse of bubbles, could be a plausible driving force to form the purine nucleosides directly from nucleobase and ribose with the desired regioselectivity. Under cavitation, the overall yield of N9 nucleosides increases compared with non-cavitation conditions, whereas the amount of the undesired ribosylamino isomers decreases. Plausible geochemical scenarios on primordial Earth are proposed that could facilitate enrichment of the desired N9 nucleosides. Under salt-free dry-wet conditions, much improved yield (7.2%) and selectivity (N9/ribosylamino = 0.45) of the N9 isomers are achieved compared with the classical routes.

Supramolecular brush copolymers have attracted continuing interest due to their unusual architectures, fascinating properties, and potential applications in many fields involving smart stimuli-responsive drug delivery systems. Herein, the first pillararene-based amphiphilic supramolecular brush copolymer (P5-PEG-Biotin⊃PTPE) was constructed on the basis of the host–guest molecular recognition between a water-soluble pillar[5]arene (P5) and a viologen salt (M). P5-PEG-Biotin⊃PTPE self-assembled into supramolecular nanoparticles (SNPs), which were utilized as a self-imaging drug delivery vehicle by taking advantage of the aggregation-induced emission (AIE) effect. Encapsulation of anticancer drug doxorubicin (DOX) caused deactivation of the fluorescences of both the tetraphenylethene (TPE) and DOX chromophores due to the energy transfer relay (ETR) effect, mediated by Förster resonance energy transfer (FRET) and aggregation-caused quenching (ACQ). The release of loaded DOX molecules can be triggered by low pH and reductase, recovering the “silenced” fluorescence caused by the interruption of the ETR effect, achieving in situ visualization of the drug release process by observing the location and magnitude of the energy transfer-dependent fluorescence variation. The biotin ligands on the surfaces of the DOX-loaded SNPs act as targeting agents to deliver DOX preferentially to cancer cells over-expressing biotin receptor. In vitro studies demonstrated that the loading of DOX by this supramolecular nanomaterial exhibited selective cytotoxicity towards cancer cells over normal cells. The potency of this sophisticated supramolecular drug delivery system in cancer therapy was further evaluated in HeLa tumor-bearing mice. In vivo experiments confirmed that the DOX-loaded SNPs possess excellent antitumor efficacy with negligible systemic toxicity.

For most conductive materials, resistance remains constant over time in the absence of external physical stimulation. Here, we report the time-dependent resistance of a quasi-two-dimensional electron gas (Q2DEG) on a KTaO3 substrate. Ar+-ion bombardment is used to achieve a Q2DEG of high density. Such a Q2DEG shows a linear increase in resistance with time without further physical stimulus. Both the resistance and its increase rate can be determined by the beam voltage of Ar+ bombardment. Furthermore, we find that light illumination strongly influences the increase rate of resistance, with the effect depending primarily on the wavelength of incident light. The Hall effect reveals that this phenomenon can be attributed to the spontaneous decrease in carrier density over time due to the migration of oxygen vacancies. Our work offers a pathway toward a self-excited resistance timer in a Q2DEG system.

Two-dimensional electron gas (2DEG) has been studied extensively because of its abundant physical properties, but no effort has been made to construct p-n or Schottky heterojunctions based on it. Here, we report a universal, practical Ar+-ion-bombardment assistant (AIBA) method to achieve a junction contact between a film of a p-type semiconductor (or metal) and 2DEG. Several materials have been attempted to verify the AIBA method, including a two-dimensional semiconductor (WSe2), an oxide superconductor (YBa2Cu3O7), an amorphous material (amorphous carbon) thin film, and a metal (Au). Despite different growth methods, all of the samples exhibit clear heterointerfaces and good rectifying behaviors, which indicates the formation of p-n and Schottky junctions. Different from the traditional methods to fabricate the vertical heterojunctions by layer-by-layer growth, the AIBA method enables us to achieve lateral heterojunctions, which may lead to remarkable physical properties. These as-fabricated heterostructures show significant photoconductivity at room temperature. This work paves the way for functional 2DEG-based devices with lateral heterojunctions.

The detection and adsorption of volatile low-molecular-weight aliphatic aldehydes is of significance, owing to their physical volatility, chemical toxicity, and widespread applications in chemical industrial processes. Here, nonporous adaptive pillar[4]arene[1]quinone (EtP4Q1) crystals with vapochromic behavior are used for the volatile aliphatic aldehyde uptake and sensing. When desolvated EtP4Q1 crystals (EtP4Q1α) are exposed to aliphatic aldehydes with different carbon chain lengths, they quantitatively adsorb vapors of these aldehydes, accompanied by different color changes. Crystal structure analyses show that the structure of EtP4Q1 transforms from EtP4Q1α into the corresponding new structures after the adsorption of these aldehydes, which leads to different color changes. The selectivity of EtP4Q1α crystals, which function as both sensors and adsorbents upon exposure to mixed aldehyde vapors, is also explored. Finally, it is demonstrated that EtP4Q1α crystals can be recycled many times without loss of performance.

A novel kind of self-assembly polyoxometalate-type hybrid material, [TEAPS] 8 P 2 W 16 V 2 O 62 , bearing of sulfo-group grafted ammonium (TEAPS) and vanadium-substituted heteropoly anions has been prepared. This compound has a layered-shape structure in total and it can process self-assembly to nano-size particle and chrysanthemum-like assemblies through supermolecular interactions. Moreover, from cyclic voltammetry studies, this kind of polyoxometalate-based hybrid compounds exhibit unique electrochemical properties that the vanadium in the complexes can process reduction in anhydrous environment, which is unlikely in water solution as a simple hydrated ion because of the water protonation about the substrate.

Studies on fluorescent polymeric aggregates have resulted in significant advances in fluorescence-based techniques in materials and life sciences. The aggregate morphology has a very important influence on the functions of fluorescent polymeric aggregates, so it is vital to access various morphologies with control. However, it is intricate and time-consuming to construct fluorescent polymeric aggregates with diverse morphologies through conventional methods that require the preparation of a series of polymers with different hydrophobic/hydrophilic volume ratios. Herein, to address this problem, we present a facile supramolecular strategy to construct fluorescent polymeric aggregates with various morphologies based on the self-assembly of supramolecular amphiphilic graft copolymers. It is worth noting that, in this supramolecular strategy, we only need to prepare two building blocks to achieve a diverse set of fluorescent polymeric aggregates.

Vertically aligned nanocomposites with vertical interfaces are a novel concept that show powerful advantages over conventional nanocomposites with lateral interfaces. However, significant obstacles to a systematic understanding of vertical interfaces still remain. Here, heteroepitaxial (BaTiO3)0.5:(Sm2O3)0.5 nanocomposite thin films have been fabricated and the conduction behaviors have been investigated. A spontaneous phase ordering with clear vertical interfaces has been found in the composite films. Because of the structural discontinuity as well as a large strain generated at the interfaces, the vertical interfaces are revealed to become the sinks to attract oxygen vacancies. The accumulated oxygen vacancies contributed to a largely reduced leakage current and a different leakage mechanism in the composite films compared to that of the pure BaTiO3 film. The present work represents a methodology to manipulate functionalities by designing configuration of the interfaces in oxide thin films.

Horizontal, single-dimensional, trianglelike poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE) nanorods are prepared under lateral nanoconfinement induced by faceted m-plane sapphire surfaces. X-ray diffraction reciprocal space mappings reveal that the polymer contains polycrystalline ferroelectric β-phase PVDF. Depolarizing fields induce different polarizations in polymer nanorods along the out-of-plane and in-plane directions. The differences are characterized using vector piezoresponse force microscopy. The depolarizing fields in the lateral PVDF-TrFE nanorods are further discussed in theory. Our results suggest that a nanofaceted m-plane sapphire can be an alternative template to induce the depolarizing fields for future nanosacle devices.Horizontal, single-dimensional, trianglelike poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE) nanorods are prepared under lateral nanoconfinement induced by faceted m-plane sapphire surfaces. X-ray diffraction reciprocal space mappings reveal that the polymer contains polycrystalline ferroelectric β-phase PVDF. Depolarizing fields induce different polarizations in polymer nanorods along the out-of-plane and in-plane directions. The differences are characterized using vector piezoresponse force microscopy. The depolarizing fields in the lateral PVDF-TrFE nanorods are further discussed in theory. Our results suggest that a nanofaceted m-plane sapphire can be an alternative template to induce the depolarizing fields for future nanosacle devices.

We demonstrate the photoconductivity and related relaxation characteristics at the metallic interfaces between SrTiO3 (STO) substrates and LaAlO3 (LAO) films deposited at oxygen pressures ranged from 2 × 10−3 to 2 × 10−6 Torr. The photoconductivity results show that all the LAO/STO interfaces exhibit both persistent and transient photoconductivity, which decrease rapidly with increasing oxygen vacancies in the heterostructures. Using double exponential model, the photoinduced relaxation processes are also analyzed. The interface with less oxygen vacancies shows slower resistance recovery process. Our results provide deeper insight into the optoelectric response of two-dimensional electron gas at complex oxides interface.

Amorphous carbon (a-C) films, deposited on Si substrates at 500 °C, were transferred onto flexible polyethylene (PE) substrates by a lift-off method, which overcomes the limit of deposition temperature. After transferring, a-C films exhibited a large piezoresistive effect. Such flexible samples could detect the change of bending angle by attaching them onto Cu foils. The ratio of the bending and non-bending resistances reaches as large as ~27.8, which indicates a potential application as a pressure sensor. Also, the a-C/PE sample revealed an enhanced sensitivity to gas pressure compared with the a-C/Si one. By controlling the bending angle, the sensitivity range can be tuned to shift to a low- or high-pressure region. The fatigue test shows a less than 1% change in resistance after 10 000 bending cycles. Our work provides a route to prepare the flexible and piezoresistive carbon-based devices with high sensitivity, controllable pressure-sensing and high stability.

Twelve new highly oxygenated lanostane triterpenoids and nine known ganoderic acids were isolated from the fruiting body of Ganoderma lucidum. The new compounds were lanostane nortriterpenoids with 27 carbons (1-5 and 8), lanostane nor-triterpenoids with 25 carbons (6 and 7), and lanostane triterpenoids (9-12) based on multiple spectroscopic data analysis, including HRESIMS, 1D-NMR, 2D-NMR, and CD. Compounds 1-5 were identified as rare nor-lanostanoids that contain a 17 beta-pentatomic lactone ring. Compound 13, possessing a lactone ring, had been isolated previously. The P-glycoprotein (P-gp) inhibitory effects of compounds 1-21 were evaluated at a concentration of 20 mu M using an adriamycin (ADM)-resistant human breast adenocarcinoma cell line (MCF-7/ADR). Compounds 1, 5, 18, and 20 and verapamil increased the accumulation of ADM in MCF-7/ADR cells approximately 3-fold when compared with the negative control. These data support the significant P-glycoprotein inhibitory activities of compounds 1, 5, 18, and 20. In silico docking analysis suggested these compounds had similar P-gp recognition mechanisms compared with those of verapamil (a classical inhibitor). Furthermore, in an in vitro bioassay, compounds 2, 4, 5, 6, and 18 showed moderate inhibitory effects against alpha-glucosidase compared with those of the positive control acarbose.

Vertical interfaces in vertically aligned nanocomposite thin films have been approved to be an effective method to manipulate functionalities. However, several challenges with regard to the understanding on the physical process underlying the manipulation still remain. In this work, because of the ordered interfaces and large interfacial area, heteroepitaxial (BaTiO3)1-x:(Sm2O3)x thin films have been fabricated and used as a model system to investigate the relationship between vertical interfaces and dielectric properties. Due to a relatively large strain generated at the interfaces, vertical interfaces between BaTiO3 and Sm2O3 are revealed to become the sinks to attract oxygen vacancies. The movement of oxygen vacancies is confined at the interfaces and hampered by the misfit dislocations, which contributed to a relaxation behavior in (BaTiO3)1-x:(Sm2O3)x thin films. This work represents an approach to further understand that how interfaces influence on dielectric properties in oxide thin films.

Oxygen vacancies (V(O)) effects on magnetic ordering in Eu₀.₅Ba₀.₅TiO₃₋δ (EBTO₃₋δ) thin films have been investigated using a combination of experimental measurements and first-principles density-functional calculations. Two kinds of EBTO₃₋δ thin films with different oxygen deficiency have been fabricated. A nuclear resonance backscattering spectrometry technique has been used to quantitatively measure contents of the V(O). Eu₀.₅Ba₀.₅TiO₃ ceramics have been known to exhibit ferroelectric (FE) and G-type antiferromagnetic (AFM) properties. While, a ferromagnetic (FM) behavior with a Curie temperature of 1.85 K has been found in the EBTO₃₋δ thin films. Spin-polarized Ti(3+) ions, which originated from the V(O), has been proven to mediate a FM coupling between the local Eu 4f spins and were believed to be responsible for the great change of the magnetic ordering. Considering the easy formation of V(O), our work opens up a new avenue for achieving co-existence of FM and FE orders in oxide materials.

We report photoelectric properties of two-dimensional electron gas (2DEG) at an amorphous LaAlO3/SrTiO3 interface. Under visible light illumination (650 nm), an enhancement of electric conductivity is observed over the temperature range from 2 to 300 K. Particularly, a resistance upturn appearing below 25 K, which is further proved to from the Kondo effect, is suppressed by the 650 nm visible light. From the results of light-assisted Hall measurements, light irradiation increases the carrier mobility rather than carrier density in the Kondo regime. It is suggested that light induces the decoherence effect of localized spin states, hence the electron scattering is weakened and the carrier mobility is improved accordingly. Moreover, the enhancement of electrical conductivity by visible light verifies that in-gap states located in the SrTiO3 side of the interface play an important role in the electrical transport of the amorphous SrTiO3-based oxide 2DEG system. Our results provide deeper insight into the pho...

Nanocomposite metal oxides have been extensively investigated in bulk and thin film forms because of their wide range of applications in microelectronics, magneto electronics, and optoelectronics (Ramesh and Spaldin, 2007). Oxide films in nanocomposite form are particularly appealing as the interaction or coupling between the constituents can lead to enhanced or new functionalities (Zheng et al., 2006). Furthermore, the nanocomposite oxide films could lead to their applications as building blocks for the assembly of nanostructures or molecular monolayers (Cheng et al., 2006). A currently primary goal is to fabricate nanocomposite oxide films using a simple and low-cost process. Self-assembly has been the focus of much research in the last four decades. It has proved its ability to offer a rich variety of periodic nanoscale patterns in an easy way (Guiton and Davies, 2007). Recent efforts have striven to bring these two fields together. A major challenge is to control a self-assembled nanocomposite oxide film to create a desired nanostructure (Moshnyaga et al., 2003). In a film-on-substrate geometry, epitaxial composite films can be divided into two forms: horizontal and vertical. These two structures can be reviewed as the building blocks for a desired nanostructure and they are also specific architectures which show lots of potential applications (Yang et al., 2009). This chapter outlines the recent results about the material design, fabrication, and physical properties of these two nanostructures.

Copper and copper oxide thin films have been synthesized on (001) SrTiO3 substrates using pulsed laser deposition. Three kinds of thin films can be achieved by changing deposition temperature and laser energy density: pure Cu, Cu:Cu2O composite, and pure Cu2O thin films. A phase diagram about the compositions of thin films has been represented and explained by redox reaction at the substrate surface during the deposition process. The present work represents a novel approach to further understand the surface reaction during deposition process and to fabricate oxide thin films with variable valence states using pulsed laser deposition.

Self-assembled oxide thin films have tremendous potential applications in next generation of multifunctional systems. However, the manipulation of nanostructures and understanding on the relationship between nanostructures and functionalities remain as substantial challenges. Recently, an interesting architecture transformation between two basic nanocomposite structures has been demonstrated, i.e., from a horizontal layered structure to a vertical columnar structure, simply by tuning the film compositions in the (YBa2Cu3O7-δ)1-x:(BaZrO3)x system. In this work, the architecture dependence of functionalities has been investigated. The nanostructure manipulation has been revealed to largely affect the lattice structures and superconductive properties, especially at the critical composition of nanostructure transformation. The present work represents a novel approach to tune the self-assembled nanostructures and to further understand that how the nanostructures contribute to the functionalities in oxide thin ...

Vertical interfaces have been approved to be able to effectively manipulate conduction behavior in oxide thin films. However, a systematic investigation is needed to understand the physical process underlying the interface effects. Here, epitaxial (BiFeO3)0.5:(Sm2O3)0.5 thin films have been fabricated and used as a model system. The microstructure and leakage behavior of (BiFeO3)0.5:(Sm2O3)0.5 composite films on (001) and (011) SrTiO3 substrates have been investigated. The different substrate orientation originated to different geometrical configurations of interfaces in the composite films. The leakage current has been significantly reduced when the complicated distribution of interfaces leads to a longer distance of conduction path. The present work represented an approach to reduce the leakage current and to further understand the way that how the interface contributes to the conduction behavior in oxide thin films.