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Taiwan's electricity consumption during summer increases significantly owing to the abnormal climatic changes caused by the greenhouse effect. An expedient strategy to develop a high-efficiency magnetic power generator can address the existing problem of power shortage in Taiwan. The magnetic power generator uses the force between the polarity of the magnet and the induced magnetic field of the coil to generate suction and thrust forces, which are generated when a magnet enters and leaves the coil, respectively, and can reduce the motor power consumption to achieve an energy saving effect. From the viewpoint of single-phase magnetic power generators, an angle transformation arrangement is used to achieve a positive power output to maximize the power efficiency, and three-phase power generation is used to maximize the output, where 8 magnets and 12 six-wire wound coils are used in conjunction with a delta or Y connection to achieve three-phase output. Each phase is 120° out of phase and each phase has 4 coils that generate power per revolution simultaneously. The high output characteristic enables the use of the three-phase magnetic power generators in several industrial applications. Herein, for a single-phase power generator, 8 magnets and 10 wires were used in an angle transformation arrangement, which achieved an output efficiency of up to 129.7%, whereas the three-phase power generator with 8 magnets and 12 six-wire wound coils with a diameter of 0.4 mm were used in conjunction with a delta or Y connection and achieved, which achieved an output efficiency of up to 82%, indicating that both these generators can be used for emergency power generation in homes, factories, or hospitals. [ABSTRACT FROM AUTHOR]

Protein stability affects the physiological functions of proteins and is also a desirable trait in many protein engineering tasks, yet improving protein stability is challenging because of limitations in methods for directly monitoring protein stability in cells. Here, we report an in vivo stability biosensor wherein a protein of interest (POI) is inserted into a microbial enzyme (CysGA) that catalyzes the formation of endogenous fluorescent compounds, thereby coupling POI stability to simple fluorescence readouts. We demonstrate the utility of the biosensor in directed evolution to obtain stabilized, less aggregation-prone variants of two POIs (including nonamyloidogenic variants of human islet amyloid polypeptide). Beyond engineering applications, we exploited our biosensor in deep mutational scanning for experimental delineation of the stability-related contributions of all residues throughout the catalytic domain of a histone H3K4 methyltransferase, thereby revealing its scientifically informative stability landscape. Thus, our highly accessible method for in vivo monitoring of the stability of diverse proteins will facilitate both basic research and applied protein engineering efforts. [ABSTRACT FROM AUTHOR]

• The sorbent with improved amine molecules dispersion was fabricated. • The capture capacity loss was insignificant after 20 cycles capture-regeneration test. • The outstanding selectivity toward CO 2 under CO 2 /N 2 mixture was presented. The modification of ordered mesoporous carbon (OMC) via NH 3 heat treatment and subsequent amine refluxing at increased temperature was investigated to improve their performances for cyclic CO 2 /N 2 separation stability and kinetics. Characterizations conducted with nitrogen adsorption/desorption isotherm, Fourier transform infrared spectroscopy, elemental analysis, and X-ray photoelectron spectroscopy demonstrated that the porosity and surface chemistry of the OMCs were tuned by modification. Adsorption evaluation with volumetric and gravimetric methods under various conditions indicated that the resulting amine-introduced N-doped OMC presented a high CO 2 adsorption capacity with fast kinetics, outstanding selectivity at 50 °C and maintained superior separation performance after 20 cycles. The presence of accessible amino groups in considerable amounts renders the modified mesoporous carbon a promising candidate for CO 2 capture from flue gas by using the temperature swing adsorption. [ABSTRACT FROM AUTHOR]

Oxysophocarpine (OSC), an alkaloid isolated from Sophora flavescens Ait, has been traditionally used as a medicinal agent based on the observed pharmacological effects. In this study, the direct effect of OSC against neuronal injuries induced by oxygen and glucose deprivation (OGD) in neonatal rat primary-cultured hippocampal neurons and its mechanisms were investigated. Cultured hippocampal neurons, which were exposed to OGD for 2 h followed by a 24 h reoxygenation, were used as an in vitro model of ischemia and reperfusion. 2-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and lactate dehydrogenase (LDH) assay were used to confirm neural damage and to further evaluate the protective effects of OSC. The concentration of intracellular-free calcium [Ca2+]i and mitochondrial membrane potential (MMP) were measured to determine the intracellular mechanisms and to further estimate the degree of neuronal damage. Changes in expression of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, p-ERK1/2, p-JNK1/2, and p-p38 MAPK were also observed in the in vitro model. It was shown that OSC (0.8, 2, or 5 µmol/L) significantly attenuated the increased absorbance of MTT, and the release of LDH manifests the neuronal damage by the OGD/R. Meanwhile, the pretreatment of the neurons during the reoxygenation period with OSC significantly increased MMP; it also inhibited [Ca2+]i the elevation in a dose-dependent manner. Furthermore, the pretreatment with OSC (0.8, 2, or 5 µmol/L) significantly down-regulated expressions of IL-1β, TNF-α, p-ERK1/2, p-JNK1/2, and p-p38 MAPK in neonatal rat primary-cultured hippocampal neurons induced by OGD/R injury. In conclusion, OSC displays a protective effect on OGD-injured hippocampal neurons by attenuating expression of inflammatory factors via down-regulated the MAPK signaling pathway. [ABSTRACT FROM AUTHOR]

At low temperatures, EuTiO3 system has very large resistivities and exhibits colossal magnetoresistance. Based on a first principle calculation and the dynamical mean-field theory for small polaron we have calculated the transport properties of EuTiO3. It is found that due to electron-phonon interaction the conduction band may form a tiny polaronic subband which is close to the Fermi level. The tiny subband is responsible for the large resistivity. Besides, EuTiO3 is a weak antiferromagnetic material and its magnetization would slightly shift the subband via exchange interaction between conduction electrons and magnetic atoms. Since the subband is close to the Fermi level, a slight shift of its position gives colossal magnetoresistance. [ABSTRACT FROM AUTHOR]

With the rapid development of urban transportation, people urgently need high-precision and up-to-date road maps. At the same time, people themselves are an important source of road information for detailed map construction, as they can detect real-world road surfaces with GPS devices in the course of their everyday life. Big trace data makes it possible and provides a great opportunity to extract and refine road maps at relatively low cost. In this paper, a new refinement method is proposed for incremental road map construction using big trace data, employing Delaunay triangulation for higher accuracy during the GPS trace stream fusion process. An experiment and evaluation were carried out on the GPS traces collected by taxis inWuhan, China. The results show that the proposed method is practical and improves upon existing incremental methods in terms of accuracy. [ABSTRACT FROM AUTHOR]

This study analyzes how anode thickness and working temperature affect heat/mass transport characteristics and cell performance of the anode-supported SOFC button cell by the finite-volume SIMPLE-C method coupled with preconditioned conjugate gradient methods. The numerical results of this work are compared with the experimental data and good agreement is observed. The simulation is carried out for various anode thicknesses (0.1, 0.5, and 1.0 mm) and working temperatures (873, 1073, and 1273 K). The results showed that the cell performance reduces about 5.05% as the anode thickness is increased from 0.1 mm to 1.0 mm; however, the influence of anode thickness on the heat/mass transport phenomenon is slight because the geometric size of anode thickness is tiny for the whole SOFC. In addition, the cell performance increases about 50.54% as the working temperature is increased from 873 K to 1273 K. A higher working temperature enhances the fluid velocity and convection and consequently promotes the chemical reaction and obtains a better cell performance. [ABSTRACT FROM AUTHOR]

Based on first-principles calculations, we reveal that the interactions between extended line defects (ELDs) of type "585" (formed by five and eight membered rings) ELDs embedded in graphene can induce ordered magnetism and self-doping of graphene. By reducing the distance between 585 ELDs, a distinct charge transfer is predicted from the center of 585 ELDs to their edges, which induces a Dirac point shift below the Fermi level, resulting in distance- or density-dependent n-type doping in the graphene. Relevant to the above finding, we found a distance-dependent spin polarization at the edges of 585 ELDs, attributable to the rigidity of the π electronic structure. Our finding suggests a promising approach for achieving π-type graphene for spintronic devices by creating 585 ELDs. [ABSTRACT FROM AUTHOR]

Five Holstein lactating dairy cows fed 5 total mixed rations (TMR) with different forage combinations were used in a 5 x 5 Latin square design to investigate diurnal variations of progesterone (P4), testosterone, and androsta-1,4-diene-3,17-dione (ADD) concentrations in the rumen. Meanwhile, different P4 inclusion levels [0 (control), 2, 20, 40, 80, and 100 ng/mL in culture fluids] were incubated in vitro for 6, 12, 24, 36, 48, and 72 h together with rumen mixed microorganisms grown on a maize-rich feed mixture (maize meal:Chinese ryegrass hay = 4:1) with an aim to determine microbial P4 transformation into testosterone and ADD. Ruminal P4, testosterone, and ADD concentrations of lactating dairy cows were greater in the TMR with forage combination of corn silage plus alfalfa hay or Chinese wild ryegrass hay than the TMR with the corn stover-based forage combination. The diurnal fluctuation pattern showed that P4, testosterone, and ADD concentrations in the rumen were greater at nighttime than daytime and peaked 6 h after feeding in the morning or afternoon. The in vitro batch cultures showed that the P4 elimination rate was highest at the P4 addition of 20 ng/mL and declined with the further increased addition of P4. The treatments after dosing P4 exhibited a shorter time than the control group until half of the initial P4 inclusion was eliminated (i.e., half time), and the lowest half time (1.46 h) occurred at the P4 addition of 20 ng/mL. In summary, the ruminal steroids concentration was affected by forage type and quality, and the rumen microorganisms exhibited great ability to transform P4 into testosterone and ADD, depending on incubation time and initial P4 addition level, suggesting that the host might affect the metabolism of its rumen microorganisms via the endogenous steroids. [ABSTRACT FROM AUTHOR]

Calcium oxide (CaO) is a promising adsorbent to separate CO2 from flue gas. However, with cycling of carbonation/decarbonation at high temperature, the serious sintering problem causes its capture capacity to decrease dramatically. A CaTiO3-decorated CaO-based CO2 adsorbent was prepared by a continuous and simple aerosol-assisted self-assembly process in this work. Results indicated that CaTiO3 and CaO formed in the adsorbent, whereas CaO gradually showed a good crystalline structure with increased calcium loading. Owing to the high thermal stability of CaTiO3, it played a role in suppressing the sintering effect and maintaining repeated high-temperature carbonation and decarbonation processes. When the calcium and titanium ratio was 3, the CO2 capture capacity was as large as 7 mmol/g with fast kinetics. After 20 cycles under mild regeneration conditions (700 °C, N2), the performance of CO2 capture of CaTiO3-decorated CaO-based adsorbent nearly unchanged. Even after 10 cycles under severe regeneration conditions (920 °C, CO2), the performance of CO2 capture still remained nearly 70% compared to the first cycle. The addition of CaTiO3 induced good and firm CaO dispersion on its surface. Excellent kinetics and stability were evident. [ABSTRACT FROM AUTHOR]

Abstract: Heat flow through the roof contributes in the total heat gain of a building. The contribution becomes more severe for single story houses covered by metal sheet roofing. This paper presents a new design for metal sheet roofing structure in order to improve its total thermal resistance. Its main concept is to utilize phase change material properties to firstly absorb the downward heat flow made by incident solar radiation to the room and then release it back to the environment by means of the naturally favored external convection especially during the nocturnal cycle. Experimental and numerical analyses have been conducted to compare thermal performance of the new design and the available normal roofing with the same materials and color. A general mathematic equation system, which can be used for further evaluation and prediction of the new design with varied parameters, has been derived for the thermal process through the roof. The results show that the new design can effectively reduce the downward thermal flow through the roof into the house. As a consequence, the cooling load of the house can be lower and more electricity for cooling attempt can be saved. [Copyright &y& Elsevier]

Abstract: Carbapenem resistance in Acinetobacter baumannii is a global problem. The purpose of this study was to elucidate current resistance mechanisms of imipenem-resistant A. baumannii (IRAB) in Taiwan and their correlation with patient outcomes. Acinetobacter baumannii clinical isolates from two teaching hospitals in Taiwan were collected in 2009 and were examined by Etest for determination of the minimum inhibitory concentrations (MICs) of imipenem, ceftazidime and ceftriaxone. Primers specific for carbapenemase genes and upstream regions were designed for PCR amplification. Bacterial isolates were genotyped by pulsed-field gel electrophoresis (PFGE). Clinical presentations of patients were analysed retrospectively. Upstream insertion sequence ISAba1 was found in 34 isolates that carried bla OXA-23, including 28 with transposon Tn2006 (ISAba1–bla OXA-23–ISAba1) in an AbaR4-type resistance island and 6 with Tn2008 (ISAba1–bla OXA-23), as well as in 8 isolates carrying ISAba1–bla OXA-51-like. All of these isolates expressed full resistance to imipenem (MIC>32mg/L). Forty-one different PFGE genotypes were found among 62 isolates. Tn2006 was found in 19 genotypes (46.3%), which is more common than ISAba1–bla OXA-51-like (12.2%) (P =0.001). Prior use of carbapenems or extended-spectrum cephalosporins for ≥5 days was the only independent risk factor significantly associated with IRAB infection (odds ratio=361.175). Higher mortality was significantly associated with infection caused by IRAB and ISAba1–bla OXA-23-carrying strains compared with infection caused by imipenem-susceptible A. baumannii and ISAba1–bla OXA-51-like-carrying strains (P =0.009 and 0.027, respectively). Tn2006 is currently the most common imipenem resistance determinant, which showed a higher ability to spread among A. baumannii and was associated with a higher mortality in IRAB-infected patients. [Copyright &y& Elsevier]

Abstract: Nanostructures of ZnO grown by chemical vapor deposition were used as sensing materials. These materials, ZnO nanorods, were characterized by scanning electron microscopy (SEM), photoluminescence (PL) and X-ray diffraction (XRD). The ozone sensing properties of various ZnO nanomaterials were studied. Under 2.5ppm ozone, ZnO nanorods showed a rapid response time of 45s and recovery time of 5s, and the sensor response (S, the ratio of the resistance in an ozone gas without UV to resistance in air with UV, S = R ozone/R air) is 850. The low defect density and high mobility accounts for the fast response and recovery times. The sensor response was measured in the range from 1 to 2.5ppm ozone in this study. [Copyright &y& Elsevier]

Abstract: An original study of an immobilized iron oxide catalyst (SiG1) with one hydroxylation intermediate of phenol (catechol) in the reductive dissolution process was performed. Also, SiG1 was applied as the catalyst for the oxidation of phenol and catechol in the presence of hydrogen peroxide. The SiG1 used in this study reacted more efficiently with catechol than the other iron oxides. Only the hydroxylation intermediates of phenol (i.e. catechol and 1,4-hydroquinone) were able to reductively dissolve SiG1. However, there are no interactions between SiG1 and phenol. The reductive dissolution of SiG1 not only occurred at acidic solution but also occurred at alkali solution in the presence of catechol. Furthermore, the solution of pH 5 was found to be a critical condition in which the interactions of SiG1 and catechol were weak in the presence or absence of H2O2. The yields of Fe2+ from SiG1 in the presence of catechol were limited by the equilibrium of reduction and the oxidation rate of iron(III, II) species. A kinetic model was applied to obtain the estimated maximum concentration of Fe2+ produced by SiG1 and estimated proportional constant in the presence of catechol at different pH conditions by using a trial and error method. Catechol induced the reductive dissolution of SiG1 and then promoted its own oxidation along with that of phenol in the presence of hydrogen peroxide. [Copyright &y& Elsevier]

Abstract: Love wave devices are very promising for sensing applications because of high sensitivity. In this paper, ZnO thin films doped with 3mol% Mg were deposited on the 64° YX-LiNbO3 substrates by RF magnetron sputtering technique. XRD, SEM, and AFM measurements investigated characteristics of the films. Under different condition such as layer thickness and substrate temperature, the phase velocity, sensitivity, temperature coefficient of frequency and phase shift of Love wave devices in a MZO/LiNbO3 structure are presented. The maximum sensitivity of MZO/LiNbO3 appears at unheated temperature and is higher than that of the SiO2/Quartz and SiO2/LiTaO3 structures reported. [Copyright &y& Elsevier]

Abstract: The influence of Mg dopants on the crystalline structures of MZO thin films and the properties of Love wave sensors has been studied in this paper. 0–20mol% Mg doped ZnO films with c-axis preferred orientation were deposited on the 64° YX-LiNbO3 substrates by RF magnetron sputtering technique. XRD, SEM, and AFM measurements investigated characteristics of the films. The phase shift and temperature coefficient of frequency of Love wave devices in MZO/LiNbO3 structures are presented. The appropriate addition of Mg dopant will produce a rough surface to raise the sensitivity. Besides, the effects of reflector gratings on the properties of Love wave sensors are also investigated. [Copyright &y& Elsevier]

Abstract: Lead-free (Na0.5K0.5)NbO3 ceramics doped with 0.5mol% SrTiO3 have been prepared by the conventional mixed-oxide method with sintering temperature at 1060–1120°C in this paper. The samples are characterized by X-ray diffraction analysis and scanning electron microscopy. The dielectric, piezoelectric and ferroelectric properties are also investigated. The results present that the increase of the sintering temperature is very effective in improving the density and electric properties. However, the samples would be deteriorated as they are sintered over the optimum temperature. 0.5mol% SrTiO3 doped (Na0.5K0.5)NbO3 ceramics show excellent properties with sintering temperature at 1100°C. [Copyright &y& Elsevier]

Abstract: Lead-free (Na0.5K0.5)NbO3 ceramics doped with CaTiO3 (0–3mol%) have been prepared by the conventional mixed oxide method in this paper. All of the CaTiO3 doped (Na0.5K0.5)NbO3 specimens do not deliquesce as exposed to water for a long time. The samples are characterized by X-ray diffraction analysis, Raman scattering spectra, scanning electron microscopy, and atomic force microscopy. The dielectric, piezoelectric and ferroelectric properties are also investigated. The results show that the addition of CaTiO3 is very effective in preventing the deliquescence and in improving the electric properties of (Na0.5K0.5)NbO3 ceramics. Finally, surface acoustic wave devices based on lead-free ceramics have been successfully fabricated and their characterization is presented. [Copyright &y& Elsevier]

Abstract: Lead-free (Na0.5K0.5)NbO3 ceramics doped with 0.5mol% CaTiO3 have been prepared by the conventional mixed-oxide method with sintering temperature at 1040–1120°C in this paper. The samples are characterized by X-ray diffraction analysis and scanning electron microscopy. The dielectric, piezoelectric and ferroelectric properties are also investigated. The results present that the increase of the sintering temperature is very effective in improving the density and electric properties. However, the properties of the samples would be deteriorated as they are sintered over the optimum temperature. The NKN-0.5%CT ceramics show excellent properties with sintering temperature at 1100°C. [Copyright &y& Elsevier]

Abstract: Lead-free (1− x)[(Na0.5K0.5)NbO3]–xSrTiO3 ceramics, where x =0–3mol%, have been prepared by the conventional mixed oxide method in this paper. All of the SrTiO3 doped (Na0.5K0.5)NbO3 specimens do not deliquesce as exposed to water for a long time. The samples are characterized by X-ray diffraction analysis, scanning electron microscopy, and atomic force microscopy measurements. The dielectric, piezoelectric and ferroelectric properties are also investigated. Our results show that the addition of SrTiO3 is very effective in preventing the deliquescence and in improving the electric properties of (Na0.5K0.5)NbO3 ceramics. Finally, surface acoustic wave devices based on lead-free ceramics have been successfully fabricated and their characterization is presented. [Copyright &y& Elsevier]

Chitosan nanoparticles loaded with lysozyme were prepared by means of an ionic gelation process of chitosan (CS) and tripolyphosphate (TPP) on mild condition. Observations by TEM showed that the spherical chitosan nanoparticles were 50–280 nm in diameter. This work focuses on the effects of molecular weight (M v ) of CS, content of CS, TPP, and initial lysozyme on encapsulation efficiency (EE), loading capacity (LC), release rate and activity of lysozyme in chitosan nanoparticles. Increasing M v of chitosan, TPP content, or decreasing initial lysozyme content, EE was enhanced whereas when increasing chitosan content, EE first increased then decreased. LC increased as M v of chitosan, content of TPP, or initial lysozyme increased or chitosan content decreased. The EE could be up to 47.3% and the LC could be 11.4%. The lysozyme release rate increased with decreasing the initial amount of lysozyme, M v , or content of chitosan and increasing the amount of TPP. The relative activity of lysozyme in all the samples was maintained above 85%. [ABSTRACT FROM AUTHOR]

Abstract: Love wave devices are very promising for sensing applications because of high sensitivity. In this paper, ZnO thin films doped with lithium (Li) and magnesium (Mg) were deposited on the 42°45′ ST-cut quartz and 36° YX-LiTaO3 substrates by RF magnetron sputtering technique. XRD, SEM, and AFM measurements investigated characteristics of the films. Under different conditions such as doping content, layer thickness, and substrate temperature, the phase velocity, temperature coefficient of frequency, electromechanical coupling coefficient and sensitivity of Love wave devices in ZnO/Quartz and ZnO/LiTaO3 structures are presented. The maximum sensitivities of ZnO/Quartz and ZnO/LiTaO3 are much higher than the SiO2/Quartz and SiO2/LiTaO3 structures reported. [Copyright &y& Elsevier]

Abstract: Love-mode surface acoustic wave (SAW) devices are very promising for liquid and gas media sensing applications because of high sensitivity. In this paper, an experimental study of the structures based on zinc oxide (ZnO) guiding layer and 36° YX-lithium tantalate (LiTaO3) substrate with different sputtering conditions to deposit ZnO films is presented. Poly-crystal ZnO films with c-axis (002) orientation have been successfully grown on the 36° YX-LiTaO3 substrate by RF magnetron sputtering technique. The deposited films were characterized as a function of argon–oxygen gas flow ratio, RF power, deposition pressure, and annealing temperature. Crystalline structures, stress, and surface roughness characteristics of the films were investigated by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), and atomic force microscopy (AFM) measurements. Highly orientated (002) films were obtained under a base pressure of 10 mTorr, containing 40% oxygen and 60% argon at RF power of 60 W and a substrate temperature around 120 °C. The films were then annealed at 600 °C. Love-mode devices based on this structure (ZnO/IDT/36° YX-LiTaO3) are presented. [Copyright &y& Elsevier]

Poly-crystal zinc oxide thin films with c-axis orientation have been successfully grown on the silicon substrate by r.f. magnetron sputtering technique. A systematic study has been made of the influence of substrate temperature on the film structural and optical properties. For SAW device applications, it is necessary for ZnO films to have c-axis oriented crystalline structure. Much lower FWHM values 0.24 &circle; is obtained under the substrate temperature at 100 &circle; C for gaining effective electromechanical coupling. Crystalline structures, stress, and surface morphology characteristics of the films were investigated by X-ray diffraction, scanning electron microscopy. Reflective Second Harmonic Generation was used to analyze the quality of the ZnO film, and the results from these ZnO films coincide with the X-ray pattern and SEM image. Optical transmittance measurements were carried out by UV-visible spectrophotometer. [ABSTRACT FROM AUTHOR]

Using theories of the magnetoresistance in the variable-range hopping regime, we are able to interpret the low magnetic field magnetoresistance data taken at liquid helium temperatures of an insulating Al70Pd22.5Re7.5 quasicrystal having a resistivity ratio R=ρ(4.2 K)/ρ(300 K) equal to 77. [Copyright &y& Elsevier]

A molydate-stabilized. 'non-activated' form of the progesterone receptor from the cytosol of oestrogen-stimulated chick oviduct has been purified to homogeneity by a three-step procedure. The first step, affinity chromatography using a N-(12-amino-dodecyl)-3-oxo-4-androsten-17β-carboxamide-substituted Sepharose gel, purified the receptor 1500-2700-fold with ≈ 50% recovery. In the second step, ion-exchange chromatography through a DEAE-cellulose column, progesterone receptor was eluted as a single peak at 0.1 M KCl. Purification after this step was >6700-fold. The third step was filtration through Ultrogel AcA 34, resulting in overall purification ≈ 7400-fold with overall recovery ≈ 25% of pure receptor on the basis of 1 binding site/molecule of Mr 85 000. The purified molybdate-stabilized receptor had a sedimentation coefficient ≈ 7.9 S ± 0.1 (n = 4) in 0.15 M or 0.4 M KCl containing sucrose 5-20% gradient and ≈ 8.9 S ± 0.2 (n = 6) in 0.15 M KCl containing glycerol 10-35% gradient, and its Stokes radius was 7.05 ± 0.10 nm (n = 3) (calculated Mr between 240 000 and 280 000). Binding specificity of the purified receptor was the same as that found in crude cytosol. SDS-PAGE revealed a single band migrating as a polypeptide of Mr ≈ 85 000 ± 2300 (n = 9). PAGE under nondenaturing conditions at total acrylamide concentrations 5%, 7% and 9% showed a single [³H]ORG 2058-protein band (ORG 2058 is a high-affinity analogue more suitable than progesterone for electrophoretic studies). The data suggest that the high molecular weight molybdate-stabilized progesterone receptor purified from oestrogen-primed chick oviduct is composed of only ≈ 85 000-Mr polypeptide chains. [ABSTRACT FROM AUTHOR]

Abstract: A simple process was developed to fabricate poly (lactic acid) (PLA) film possessing a highly ordered nanoscale surface. For the first step, an array of silica microspheres was prepared by self-assembly on a completely hydrophilic silicon wafer. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) images showed that a highly ordered array was formed, and then this array was used as the template for fabricating polymer film with highly ordered nanoscale surface. Next, a PLA solution was spin coated on the template. After solidifying, silica microspheres were embedded in the thin layer of PLA, maintaining their highly organized structures. Finally, silica microspheres were etched away by hydrofluoric acid, and only the PLA film with a close-packed hexagonally pattern structure was left on the silicon wafer substrate. [Copyright &y& Elsevier]

Abstract: A simple method was developed to fabricate nano-patterned protein layers on poly (lactic acid) (PLA) surface by dewetting method. It was found that nano-patterned protein layers were formed on PLA surface by slow drying in high humidity. The influence of wettability and viscoelastic properties of substrates were also investigated. As a result, typical spinodal dewetting patterns formed for BSA. However, network structures were obtained for collagen at acidic condition and well-oriented fibrils at neutral pH. It was attributed to dewetting on hydrophobic substrate as well as the plasticity and variety of collagen self-assemblies. [Copyright &y& Elsevier]

Abstract: Graft polymerization of acrylic acid (AA) onto poly(l-lactide) (PLLA) film by UV irradiation was carried out to develop surfaces for N-methylene phosphonic chitosan (NMPC) immobilization. The properties of modified films were discussed by colorimetric method, attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), contact angles, atomic force microscopy (AFM) and osteoblast incubation. The results showed that AA solution concentration and irradiation time had effect on the graft carboxyl densities. Comparing the ATR-FTIR images, two new peaks at 1561cm−1 and 1632cm−1 proved that NMPC was immobilized on the film surface successfully. The water contact-angles were decreased from 90±5° to 37±5° after modification. The AFM images indicated that the surface of the combined film was rougher than that of untreated film. The grafted film provided an excellent substrate for the growth of osteoblast. [Copyright &y& Elsevier]

A bandpasss filter (BPF) using active transmission lines (ATLs) in a standard 0.18 μm CMOS technology at the 2.4 GHz band is presented. The ATL consists of a passive transmission line which is loaded by Λ‐type circuits periodically. The ATL incorporating the Λ‐type circuits not only compensates its resistive losses but also increases the slow‐wave factors. Moreover, an inductor is also used in the BPF to improve the passband flatness and circuit instability. Under a power consumption of 21 mW, the BPF achieves 0.5 dB insertion loss at the centre frequency of 2.3 GHz, and a 3 dB bandwidth of 550 MHz. [ABSTRACT FROM AUTHOR]

Patients with viral infections are susceptible to osteoporosis. This cohort study investigated the correlation between human papillomavirus (HPV) infections and the risk of osteoporosis via 12,936 patients with new-onset HPV infections and propensity score-matched non-HPV controls enrolled in Taiwan. The primary endpoint was incident osteoporosis following HPV infections. Cox proportional hazards regression analysis and the Kaplan-Meier method was used to determine the effect of HPV infections on the risk of osteoporosis. Patients with HPV infections presented with a significantly high risk of osteoporosis (adjusted hazard ratio, aHR = 1.32, 95% CI = 1.06–1.65) after adjusting for sex, age, comorbidities and co-medications. Subgroup analysis provided that populations at risk of HPV-associated osteoporosis were females (aHR = 1.33; 95% CI = 1.04–1.71), those aged between 60 and 80 years (aHR = 1.45, 95% CI = 1.01–2.08 for patients aged 60–70; aHR = 1.51; 95% CI = 1.07–2.12 for patients aged 70–80), and patients with long-term use of glucocorticoids (aHR = 2.17; 95% CI = 1.11–4.22). HPV-infected patients who did not receive treatments for HPV infections were at a greater risk (aHR = 1.40; 95% CI = 1.09–1.80) of osteoporosis, while the risk of osteoporosis in those who received treatments for HPV infections did not reach statistical significance (aHR = 1.14; 95% CI = 0.78–1.66). Patients with HPV infections presented with a high risk of subsequent osteoporosis. Treatments for HPV infections attenuated the risk of HPV-associated osteoporosis. [ABSTRACT FROM AUTHOR]

Lycium barbarum polysaccharides (LBP) have been reported to have a wide range of beneficial effects including neuroprotection, anti -aging and anticancer. However, the anti -inflammation mechanism of LBP on primary cultured rat hippocampal neurons injured by oxygen-glucose deprivation/reperfusion (OGD/RP) is incompletely understood. We investigate the neuroprotective effects of LBP on neonatal rat primary cultured hippocampal neurons injured by OGD/RP with different approaches: MTT assay was used to detect cell viability, lactate dehydrogenase leakage was used to detect neuronal damage, formation of reactive oxygen species was determined by using fluorescent probe DCFH-DA. Hoechst 33,342 staining and TUNEL staining were used to determine the cell apoptosis. JC-1 was used to evaluate loss of mitochondrial membrane potential (MMP). The fluorescence intensity of [Ca] in hippocampal neurons was determined by laser scanning confocal microscopy. The expression of various apoptotic markers such as TLR4, IκB, IL-6 and NF-κB were investigated by RT-PCR and western blot analysis. Results from each approach demonstrated that LBP increased the cell abilities and decreased the cell morphologic impairment. Furthermore, LBP increased MMP but inhibited [Ca] elevation and significantly suppressed overexpression of NF-κB, IL-6 TLR4 and increased IκB expression. [ABSTRACT FROM AUTHOR]

A submarine pipeline is mainly used to transfer liquid or gas between two land masses and may thus suffer corrosion from the severe subsea environment. Hence, the safety of a corroded pipeline must be evaluated by professionals. In this study, stress analysis of a corroded pipeline is conducted for three situations (i.e. simple defect, complex surface, and interacting defects). A simple defect is modelled using the 3D drawing software CATIA, and ANSYS simulates the stress of the corrosion defect; the effects of the defect were determined using different defect widths and depths. A complex surface involves the use of AUTOCAD VBA to establish the 3D surface based on random data and to generate an Initial Graphics Exchange Specification file. CATIA is used for file opening and geometric modelling and is finally keyed into ANSYS for analysis. ANSYS then is used for the stress analysis. The analysis covers a single rectangular defect, a spherical defect, and interacting effects of both types of defects. Finally, the stress analysis results are explored. [ABSTRACT FROM PUBLISHER]

This paper presents a 2.4-GHz vital-sign sensor for noncontact healthcare monitoring applications. The sensor consists of one VCO, two circulators, three Wilkinson power dividers, one 90° hybrid, two mixers, and two active band-pass filters. The sensor with the injection-locked VCO and the I/Q demodulator reduces system complexity and avoids the null detection points, respectively. Moreover, the sensor achieves a long sensing distance without the need of a low-noise amplifier or a power amplifier. Under total power consumption of 17.8 mW, experimental results demonstrate that vital-sign signals including respiration and heartbeat can be identified and detected correctly up to 80 cm away from the subject. Moreover, the errors of heartbeats are less than 4.9% compared to a contact device. [ABSTRACT FROM PUBLISHER]

Graphite encapsulated iron metal nanoparticles (FeGEM) are a core/shell nanostructured material. By introducing various liquid alcohols as carbon source during modified arc-discharge synthesis procedures, we succeeded in raising the yield rate of FeGEM from 10 wt.% to 40–50 wt.%. However, the hydrophobic outer graphite (graphene) shells and the strong magnetic attraction between inner ferromagnetic iron cores can easily lead to rapid agglomeration and precipitation of FeGEM nanoparticles in a polar solvent such as water. As a result, it may impede many potential applications of FeGEM nanoparticles in numerous fields. To overcome the problem, it is necessary to change the hydrophobic surface of FeGEM nanoparticles to a hydrophilic one. In this work, we show that progressive sequential refluxing in nitric acid, thionyl chloride and tetraethylenepentamine (TEPA) can modify FeGEM nanoparticles with different functional groups. After refluxing with nitric acid solution, the grafted FeGEM is able to disperse in polar solvent, such as deionized water or ethanol for over 24 h. Zeta potential analysis and SQUID were used to characterize the grafted FeGEM at the refluxing step, and ultraviolet–visible spectrophotometry was used to measure the suspension ability of modified FeGEM nanoparticles in a colloidal system. [ABSTRACT FROM AUTHOR]

BACKGROUND: This study aimed to quantify total lymphatic fluid spaces of the inner ears volumetrically in the dog in order to find a correlation between the lymphatic volume of the inner ears and motion sickness susceptibility. METHODS: A total of 16 healthy adult Beagle dogs were used to delineate the lymphatic fluid spaces of inner ears by magnetic resonance imaging with a 3-dim ensio nal-c onstr uctiv e interference steady-state sequence. Manual segmentation was applied for 3-dimensional reconstruction and volumetric quantification of total lymphatic space. The susceptibility of Beagle dogs to motion sickness was judged by latency of vomiting during rotatory stimulus. RESULTS: The volume range of total fluid space in the vestibule and cochlea of Beagle dogs is 55.07 ± 6.2 mm3. There is no significant difference in the total lymphatic volume of bilateral inner ears between 2 different motion sickness susceptibility groups (i.e., sensitive group and insensitive group), but the difference of lymphatic volume in the cochlea and vestibule between bilateral inner ears in insensitive group is greater than that of sensitive group. Moreover, a significant positive correlation was found between bilateral inner ear difference in lymphatic volume and vomiting latency. CONCLUSION: Magnetic resonance imaging could be used as a method to evaluate the inner ear lymphatic fluid volume of Beagle dogs with different susceptibilities to motion sickness, through which we found that motion sickness susceptibility is related to the difference in lymphatic volume in the vestibule and cochlea between bilateral inner ears, and the larger the volume difference, the lower the susceptibility. [ABSTRACT FROM AUTHOR]

Photoelectrocatalytic hydrolysis of ammonia borane (AB) is a promising technique for producing hydrogen gas (H 2) in the presence of an appropriate photocatalyst under light irradiation and bias. The application of cuprous oxide on titanium dioxide nanotube arrays (Cu 2 O/TNA) for the photoelectrocatalytic hydrolysis of AB was studied. Cu 2 O/TNA exhibited a spectral response in the ultraviolet–visible region and an onset wavelength of 600 nm. With AB in an electrolyte, Cu 2 O/TNA exhibited a significant increase in its photocurrent spectral response at a bias of 0.1 V versus Ag/AgCl. The H 2 generation rate by photoelectrocatalysis (under 5-mW cm−2 irradiation at 455 nm; bias of 0.1 V vs. Ag/AgCl) was 0.018 μmol s−1 cm−2, which was twice that by photocatalysis and four times those by catalysis and electrocatalysis; a Faradaic efficiency of 77% (corresponding to the oxidation reaction of AB) was also observed. Hence, Cu 2 O/TNA is an efficient photoanode for photoelectrocatalytic hydrolysis of AB. [Display omitted] • Cu 2 O/TNA is a promising photoanode for photoelectrocatalytic hydrolysis of AB. • Cu 2 O/TNA performed a significant spectral response at 0.1 V versus Ag/AgCl. • H 2 generation rate by PEC was twice that by PC and four times those by C and EC. • The reaction at 0.1 V versus Ag/AgCl corresponded to the oxidation reaction of AB. [ABSTRACT FROM AUTHOR]

In this study, the structural and ferroelectric properties of Bi 0.95 Dy 0.05 FeO 3 (BDFO) thin films prepared using pulsed laser deposition (PLD) under various deposition rates (D r) and substrate temperatures (T s) are investigated. Regardless of D r in the range of 1.0–3.0 Å/s, a predominant crystallographic orientation, BDFO(001), and similar microstructure are consistently identified for BDFO films at T s = 500 °C. Stress analysis revealed the distinct stress states with D r. Ferroelectric properties might depend on stress in this case. The compressive stress found for the film at D r = 3.0 Å/s results in enhanced polarization, with a 2P r of 180 μC/cm2. In contrast, tensile stress for the film at D r = 1.0 Å/s exhibits a lower 2P r = 106 μC/cm2. Besides, XRD results for the films at different T s demonstrated that the optimal temperature for BDFO growth is T s = 500 °C, which exhibits the lowest leakage current density due to the suppressed vacancies and improved crystallinity. These findings provide comprehensive insights into the structural and ferroelectric properties of BDFO films, elucidating the impact of deposition rate on their characteristics, and significantly improving ferroelectric properties of BDFO films for the applications. • BDFO(001) texture is well confirmed for Bi 0.95 Dy 0.05 FeO 3 films. • The stress in the BDFO thin film could be well controlled by the deposition rate. • The ferroelectricity of BDFO film could be tuned by the stress control. • Enhanced 2P r = 180 μC/cm2 is obtained for the films with larger compressive stress. • The optimal substrate temperature results in promoted crystallinity and texture. [ABSTRACT FROM AUTHOR]

Abstract: Conventional radiography is insensitive for early and accurate estimation of the mal-alignment and wear of knee prostheses. The two-staged (rough and fine) registration of the model-based RSA technique has recently been developed to in vivo estimate the prosthetic pose (i.e, location and orientation). In the literature, rough registration often uses template match or manual adjustment of the roentgen images. Additionally, possible error induced by the nonorthogonality of taking two roentgen images neither examined nor calibrated prior to fine registration. This study developed two RSA methods for automate the estimation of the prosthetic pose and decrease the nonorthogonality-induced error. The predicted results were validated by both simulative and experimental tests and compared with reported findings in the literature. The outcome revealed that the feature-recognized method automates pose estimation and significantly increases the execution efficiency up to about 50 times in comparison with the literature counterparts. Although the nonorthogonal images resulted in undesirable errors, the outline-optimized method can effectively compensate for the induced errors prior to fine registration. The superiority in automation, efficiency, and accuracy demonstrated the clinical practicability of the two proposed methods especially for the numerous fluoroscopic images of dynamic motion. [Copyright &y& Elsevier]

Abstract: Samarium (Sm) modified lead titanate ceramics with a composition of (Pb0.85Sm0.1)(Ti0.98Mn0.02)O3 piezoceramics doped with SiO2 were prepared by conventional mixed-oxide method. Microstructural and compositional analyses of the PbTiO3-based ceramics have been carried out using X-ray diffraction (XRD) and scanning electron microscope (SEM). The effects of Si additives on the sintering temperature and piezoelectric properties of the ceramics have been investigated. We successfully showed that the SiO2 was helpful in lowering the sintering temperature from 1250 to 1100°C and still keeps good piezoelectric and dielectric properties. Surface acoustic wave (SAW) devices were fabricated and the properties, including phase velocity and temperature coefficient of frequency (TCF), were measured. [Copyright &y& Elsevier]

Abstract: In this study, tin dioxide (SnO2) nanowires were synthesized on a silicon substrate (111) using a direct gas reaction route on a large scale at 800°C. These SnO2 nanowires were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman-scattering spectroscopy. XRD, SEM and TEM indicated that the products were tetragonal SnO2 nanowires with lattice parameters of a =4.73Å and c =3.17Å. Three vibration modes were observed at 478, 634, and 776cm−1 in the Raman spectra of the samples. Complex impedance analysis of SnO2 nanowires well fitted with a simple RC electrical model. According to the current–voltage (I–V) measurements, it was found that the SnO2 nanowires were a good sensing for detecting carbon monoxide. The response to 500ppm CO of the SnO2 nanowires reached 60%. [Copyright &y& Elsevier]

The highly purified, molybdate-stabilized '8-9-S' form of the chick oviduct progesterone receptor complexed with [³H]progesterone (Specific activity ≈ 10-12 nmol bound steroid/mg protein) was prepared according to the three-step method [Renoir et al. (1982) Eur. J. Biochem. 127., 71-79] and 50-90 µg samples were injected into a goat and a rabbit. Specific antibodies were observed as early as 2 weeks following the first booster injection and increased considerably 12 weeks later after further booster injections. Results were similar in the two animals, with higher titers observed in the goat. Antibodies cross-reacted with the 'transformed' 4-S form of the chick oviduct progesterone receptor. They also cross-reacted with molybdate-stabilized 8-9-S progesterone receptors of mammalian species (obtained from MCF-7 human breast cancer cells and from rabbit and mouse uteri), suggesting some evolutionary conservation of steroid hormone receptors. No cross-reaction was observed with chick oviduct oestradiol receptor and with chick plasma transcortin (a non-receptor progesterone-binding protein). [ABSTRACT FROM AUTHOR]

Guided tissue regeneration is a standard surgical treatment for periodontal regeneration. For the purpose of producing a novel guided tissue regeneration membrane with antibacterial activity and osteogenesis, coaxial electrospinning was utilized to manufacture core/shell structure fiber mats. Polyvinylpyrrolidone loaded with naringin was worked as the core of the fiber to enrich osteogenesis and poly(lactic-co-glycolic acid)–Poly- l -lactic acid–Poly- dl -lactic acid loaded with metronidazole was designed as the shell of the fiber to prevent or treat infections caused by bacteria. The loaded metronidazole with an initial short-term release and the loaded naringin with a long-term sustainable release allowed the membranes with multifunction of antibacterial activity and boosting the proliferation of osteoblast with improved osteogenesis, respectively. The fibrous membrane also shielded osteoblast and fibroblasts from ingrowth. The study provided a simple coaxial electrospinning crafts for fabricating multifunctional guided tissue regeneration membranes. A graphical abstract is available online as a supplementary material. [ABSTRACT FROM AUTHOR]

The low-field dielectric responses of pure and 0.15 wt. % MnO-added (1-x)Pb(Fe2/3W1/3)O3–xPbTiO3 [(1-x)PFW–xPT] were investigated with the empirical model, the Curie–Weiss law and the spin-glass model. According to the experimental data and the fitting results, we conclude that (1) the lattice structure is changed and the electron compensation is induced with MnO addition. (2) The dielectric behaviors obey the Curie–Weiss law as the temperature is much far above Tm for all samples. (3) TCW, the temperature at which the dielectric behaviors deviate from the Curie–Weiss law, is higher and the diffuse phase characteristic is more obvious as decreasing PbTiO3 content or adding MnO. (4) The tailed temperature-dependent local order parameters, which are derived from the spin-glass model and the experimental results, for more diffuse phase transition relaxors show higher thermal stability in the spontaneous polarization microregions. (5) The temperature-dependent local ordering parameters change from a long-range-ordered ferroelectric state to a short-range-ordered relaxor with decreasing the PbTiO3 content or adding MnO. [ABSTRACT FROM AUTHOR]

Regarding the dielectric characteristics of the diffusion phase transition (DPT) in ferroelectric relaxor materials, several researchers have provided similar but different laws to explain these phenomenon. These laws, presented by Burfoot et al. and Eiras et al., have been proven to provide a better explanation, especially the dielectric diffusion phenomenon, of the incomplete DPT materials if compared with the models presented by Smolensky, and Isupov. However, the differences in fitting adaptability and the physical and mathematical meanings between these two laws have never been discussed. In this paper, we analyze these two laws in the (1-x)Pb(Fe2/3W1/3)-xPbTiO3 [(1-x)PFW-xPT] relaxor system using the statistical regression theory. We find that the laws of both Burfoot and Eiras demonstrate the same adaptability and provide smaller estimation bias on the samples than the models of Smolensky and Isupov, despite the complete or incomplete DPT characteristics. When x is smaller, the samples tend to be complete DPT phenomenon and the estimation bias of Smolensky and Isupov`s models is relatively smaller. However, when the samples show ferroelectric characteristics, the estimation bias will be increased. [ABSTRACT FROM AUTHOR]

In this paper, pure and 0.15 wt %MnO additives of (1-x)Pb(Fe2/3W1/3)O3–xPbTiO3 [(1-x)PFW-xPT] with x=0.1, 0.2, 0.3, and 0.4 were synthesized by the conventional solid state reaction method. The dielectric diffusion properties were investigated with the empirical law. The lattice structure was found to transfer from tetragonal to pseudocubic and the diffusion phase characteristic is more notable as decreasing PbTiO3 compositions or adding MnO additives. Moreover, the dielectric loss is improved and the space charge polarization effect is vanished as adding MnO additives in 0.7PFW-0.3PT compounds. We suggested it was probably due to the lead vacancy which is substituted by the manganese ions or the interstitial manganese ions intervene into the interstice between the positive and negative ions. [ABSTRACT FROM AUTHOR]

Highlights • High throughput and label-free particle sensing with microwave resonators at S band is demonstrated. • Phase-locked loop is employed for improving detection resolution. • Smaller particle sensing is achievable as channel size scaling-down. • Results were optimized by using the sensors fabricated by standard printed circuit board manufacturing technology. • Much shorter particle dwell time in split ring resonator sensor. Abstract We developed a novel particle sensor based on micro channels embedded in microwave resonators, which are fabricated by standard print circuit board manufacturing technology. The sensing frequency falls in the range 2–4 GHz, the widely used microwave S band. A 70 μm-particle can produce a frequency shift of 0.5 MHz in a sensor with 150 μm channel size, with a dwell time of 0.5 ms by using double split ring resonators. These resonator sensors may employ phase-locked loop in achieving a higher detection resolution. [ABSTRACT FROM AUTHOR]

The goal of this study was to clarify the protective role of the Wnt/β-catenin pathway agonist SKL2001 in a rat model of Caerulein-induced acute pancreatitis. AR42J cells and rats were divided into 4 groups: control, Caerulein, SKL2001 + Caerulein, and SKL2001 + control. Cell apoptosis was examined using flow cytometry. Hematoxylin–eosin staining was performed to observe pathological changes in pancreatic and small intestinal tissues. Inflammatory cytokines were detected by enzyme-linked immunosorbent assay (ELISA), while genes related to the Wnt/β-catenin pathway were quantified using quantitative real-time PCR. In vitro results showed that Caerulein promoted cell necrosis, inhibited the Wnt/β-catenin pathway, and increased the level of inflammatory cytokines. However, SKL2001 reduced cell necrosis and inflammatory cytokines and activated the Wnt/β-catenin pathway. Additionally, in vivo results demonstrated the accumulation of fluid (i.e., edema), hemorrhage, inflammation and necrosis of the pancreatic acini occurred 6 h after the final Caerulein induction, with the damage reaching a maximal level 12 h after the final Caerulein induction; meanwhile, the Wnt/β-catenin pathway was evidently inhibited with an enhanced level of inflammatory cytokines. The aforementioned damage was further aggravated 12 h later. Nevertheless, the pancreatic and small intestinal tissue damages were alleviated in Caerulein-induced rats treated with SKL2001. In conclusion, activation of the Wnt/β-catenin pathway could inhibit Caerulein-induced cell apoptosis and inflammatory cytokine release, thus improving pancreatic and intestinal damage in rats with acute pancreatitis. [ABSTRACT FROM AUTHOR]

People leave traces of movements that might affect the behavior of others both online in cyberspace and offline in real space. Previous studies, however, have used only questionnaires, network data, or GPS data to study spatio-temporal behaviors, ignoring the relationship between online and offline activities, and overlooking the influence of previous activities on future behaviors. We propose a Pheromone-based Fusion Model, viewing human behaviors as similar to insect foraging behaviors to model spatio-temporal recreational activity patterns, on and offline. In our model, website data were combined with GPS data to evaluate the attractiveness of destinations over time using twenty-nine landscapes in Beijing, China; big website data and GPS trajectories were gathered from 181 users for 57 months. The datasets were portioned into two periods. Online and offline recreational pheromones were calculated from the first period and the visitation rates were extracted from the second period. These data were subsequently applied in a regression analysis to determine unknown parameters and estimate the attractiveness of destinations. The proposed method was compared with two other approaches that use either GPS data or online data alone, in order to verify effectiveness. The results show that the proposed method can estimate future behaviors, based on real world and online past actions. [ABSTRACT FROM AUTHOR]

The unbalanced distribution of taxi passengers in space and time affects taxi driver performance. Existing research has studied taxi driver performance by analyzing taxi driver strategies when the taxi is occupied. However, searching for passengers when vacant is costly for drivers, and it limits operational efficiency and income. Few researchers have taken the costs during vacant status into consideration when evaluating taxi driver performance. In this paper, we quantify taxi driver performance using the taxi's average efficiency. We propose the concept of a high-efficiency single taxi trip and then develop a quantification and evaluation model for taxi driver performance based on single trip efficiency. In a case study, we first divide taxi drivers into top drivers and ordinary drivers, according to their performance as calculated from their GPS traces over a week, and analyze the space-time distribution and operating patterns of the top drivers. Then, we compare the space-time distribution of top drivers to ordinary drivers. The results show that top drivers usually operate far away from downtown areas, and the distribution of top driver operations is highly correlated with traffic conditions. We compare the proposed performance-based method with three other approaches to taxi operation evaluation. The results demonstrate the accuracy and feasibility of the proposed method in evaluating taxi driver performance and ranking taxi drivers. This paper could provide empirical insights for improving taxi driver performance. [ABSTRACT FROM AUTHOR]