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We describe the implementation of the current Flexible Atomic Code (FAC) unique electron central potential within the autostructure code. We show that the two codes then give the same atomic data for all practical application purposes. However, autostructure has more flexible potential options which can lead to a more accurate description of atomic processes, especially in low-charged ions. [ABSTRACT FROM AUTHOR]

The Zr55Cu30Al10Ni5 amorphous alloy with thickness 0.5 mm and width of 75 mm was fabricated by twin-roll casting. Due to high rolling force, the alloy exhibited high energy state, high free volume and microstructure inhomogeneity. However, the friction property is not clear because of excellent plasticity and high free volume. The present study tested the friction property of the alloy by rotating pin-on-disk method and investigated the friction behavior and wear mechanism. Besides, the abrasive resistance was improved by subsequent annealing treatment. The results show that the wear mechanisms are mainly abrasive wear, adhesion wear, delamination wear and fatigue wear. The wear law is in accordance with the Archard's empirical wear law. The structural stability and uniformity of that cast strip can be increased by annealing the cast strip at the glass transition temperature. Meanwhile, the wear resistance of the amorphous alloy is improved, and the wear rate in the annealed state is reduced to 88.7 percent of that in the as-cast state, so that abrasive resistance is improved. This study provides a little theoretical basis for amorphous alloy as wear-resistant material and expands the application of amorphous alloy in engineering materials. [ABSTRACT FROM AUTHOR]

Eu3+/Tb3+-co-doped CaWO4 phosphors were synthesized by a simple green co-precipitation process. The structure of the samples was investigated by X-ray diffraction. The photoluminescence spectra and fluorescence decay lifetimes of the samples were measured to investigate the luminescence properties. We analyzed the energy transfer process between Eu3+- and Tb3+-doped CaWO4. As the Tb3+ to Eu3+ energy transfer process was confirmed, Eu3+- and Tb3+-co-doped CaWO4 phosphors showed a color-tunable emission from green to red under a 365-nm UV lamp. [ABSTRACT FROM AUTHOR]

To investigate the relationship between service temperature ranging from –40~250℃, and size effect on tensile properties of thin ASS-304 sheets with nine different thicknesses (40~500 μm), uniaxial tensile tests were performed on thin ASS-304 sheets of the same average grain size in the present study. Within the thickness range of 40 to 300 μm, corresponding to η = t/d values from 1.1 to 8.1. The ultimate tensile strength (UTS), yield strength (YS), and elongation (EL) of ASS-304 exhibits a dimensional effect of "the thinner, the stronger". For example, as the η increases from 1.1 to 8.1, the UTS rapidly decreased from 1798.8 to 839.0 MPa at 20℃, from 1703.1 to 526.9 MPa at 150℃, and from 1661.2 to 478.9 MPa at 250℃, attenuation of 53.36, 69.06, and 71.17%, respectively. Meanwhile, the YS at 20℃ are separately 1768.9 to 418.7 MPa with 1695.2 to 343.3 MPa at 150℃ as well as 1645.7 to 330.1 MPa at 250°C, decrease the proportion of 76.33%, 79.75% and 79.94% respectively. Notably, the UTS, YS, and EL at 150 and 250℃ are lower than those at 20℃. The true stress value of ASS-304 was enhanced at –20 and –40℃, and the true strain increases first and then weakens as the thickness increases, the reason is the transformation- induced-plasticity (TRIP) effect of ASS-304 in stretching. The asymptotic function describes the relationship between strength and the values of η, while the Chapman function represents the relationship between elongation and the η. A linear variation exists between service temperature and tensile properties. And relevant empirical equations including T-η- and T-η-tensile properties were established, which can predict the UTS, YS, and EL of thin ASS-304 sheets under different service temperatures. [ABSTRACT FROM AUTHOR]

MADS-box family genes play an important role in the development of plant reproductive growth, but there have been no genome-wide characterization reports on Isatis indigotica Fortune. In this study, eighty IiMADS genes were identified and clustered into 16 subgroups (3 type I and 13 type II) with reference to Arabidopsis MADS genes. Most IiMADS proteins in the same cluster had similar exon-intron and motif structures. Seventy-four IiMADS genes were randomly distributed among 7 chromosomes, and the remaining genes were contigs. The RNA-seq data showed that most IiMADS transcripts were highly enriched in roots, stems, flowers and fruits but rarely in leaves. Based on our phylogenetic and expression analyses, the IiSVP gene from I. indigotica was cloned and functionally characterized. qRT-PCR revealed that IiSVP is mainly expressed in stems, buds, flowers, and fruits. The IiSVP protein could interact with IiSOC1 and IiFLC, which was detected by BiFC and Y2H. The heterogeneous overexpression of IiSVP in Arabidopsis showed that it suppresses floral organ development, delays flowering and is significantly related to the expression of flowering genes such as FLC, SOC1 and GA20ox2. This study provided new information on the MADS family in I. indigotica and suggested that IiSVP is a key gene in suppressing flowering in I. indigotica. [ABSTRACT FROM AUTHOR]

Tb3+-doped Zn–Al (Zn–Al–Tb) hydrotalcites with tunable blue-green emission synthesized by co-precipitation. The compositions and properties of the samples were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and photoluminescence. XRD and FTIR results indicate that the samples were in a pure hydrotalcite-like phase. The fluorescence spectra indicate that the Zn–Al hydrotalcite exhibited blue fluorescence at 350–450 nm. Under an excitation wavelength of 231 nm, Zn–Al–Tb hydrotalcite exhibited the characteristic green emission of 5D0–7FJ of Tb3+, and the fluorescence lifetime of the sample was 0.8442 ms. At different excitation wavelengths, Zn–Al–Tb hydrotalcites can exhibit emission from green to blue wavelengths, which indicates that Zn–Al–Tb hydrotalcites are potential multicolor functional materials. [ABSTRACT FROM AUTHOR]

This article has been retracted. Please see the Retraction Notice for more detail: https://doi.org/ [ABSTRACT FROM AUTHOR]

The present study aims to optimize friction stir welding (FSW) using statistical tools, thereby improving the mechanical properties of butt welds and achieving the desired butt welds for practical applications, such as arts of traditional handicraft and metal sculpture products. The influence of friction stir welding parameters on butt welds was determined by the orthogonal array test and variance analysis. The pin length, dwell time, tool rotational speed, and traverse speed were found to be highly significant factors of the butt welds. In addition, the response surface method (RSM) was used to construct the model from the data of the orthogonal array experiment run using the significant factor application via Taguchi's design. The experimental results showed that the mechanical properties of butt welds were enhanced by FSW, and the strength of butt welds reached 91%. Furthermore, the fractured properties showed a fine recrystallized grain with fewer defects or imperfections, thereby improving the workability. This was of great significance to the structural safety of large-scale metal sculptures and the pursuit of precision of handicraft products. Based on the tensile strength regression models of friction welding, the linear, interactive, and quadratic models were established, and the quadratic model with 3D contours of the tensile behavior was further developed. The results showed that the predicted values of RSM for butt weld tensile properties were very close to the experimental data, which proved the advisability and availability of RSM based on Taguchi's design in improving the mechanical properties of friction stir welds. [ABSTRACT FROM AUTHOR]

A solar heat pump system was designed and built. In this paper, the operation performance of the system was investigated experimentally. The effects of significant parameters such as the water temperature at the inlet and outlet of the evaporator, collector, and condenser and the solar radiation intensity were considered. When the water temperature at the condenser inlet was set at different values, the water temperature at the evaporator inlet was found to be proportional to the suction pressure and discharge pressure of the compressor and inversely proportional to the compression ratio. At different water temperatures at the evaporator inlet, the influence of the water temperature at the condenser outlet on the suction pressure was not obvious; however, the maximum change in the suction pressure was 0.9MPa. The power consumption of the compressor was hardly affected. Lower water temperature at the collector inlet contributes to improvement of its heat collection efficiency, and various factors should be considered in the design of the collector. The higher was the water temperature at the evaporator inlet and the lower was the water temperature at the condenser outlet, the larger was the found coefficient of performance (COP) of the heat pump unit COP , as well as the found COP of system COP . In addition, as the solar radiation intensity grew, the heating capacity and COP increased continuously, the maximum variation in COP being 0.4. It is hoped that this research will offer valuable insights for designing advanced solar heat pump (SHP) systems. [ABSTRACT FROM AUTHOR]

This work studies the solidification processes and microstructures of Zr55Cu30Al10Ni5 (at. pct) and Cu64Zr36 (at. pct) amorphous alloy sheets fabricated by twin-roll strip casting. A largely excessive volume was frozen in the alloy during the twin-roll strip-casting process, resulting in many soft regions and the inhomogeneity of the microstructure in the amorphous alloy sheet. The results provide insights into the solidification process of amorphous alloys and guidelines for adjusting their microstructure. [ABSTRACT FROM AUTHOR]

The packing patterns have close correlation with the thermoelastic properties of DNA adsorption films and the relevant detection signals of microcantilevers. In this paper, we investigate the influence of packing patterns on the thermoelastic properties of DNA adsorption films, the detection signals of microcantilevers and their temperature dependence. First, the Parsegian's empirical potential based on a mesoscopic liquid crystal theory is employed to describe the interaction energy among coarse-grained DNA cylinders; then, the thought experiment method and the force balance method of nonlinear elastic network nodes are combined to characterize the elastic modulus, prestress and thermal expansion coefficient of DNA adsorption films; finally, based on an effective macroscopic continuum model for DNA microbeam deformation, we study the microcantilever resonance frequency shifts caused by DNA adsorptions and the temperature effect on the microcantilever static deflections, respectively. Results show that, compared with the convex-packaged, the re-entrant honeycomb packing pattern endows DNA adsorption films with a larger adjustable range of the elastic modulus and prestress, so as to make DNA-microcantilevers having an enhanced dynamic detection signal whereas a weaker response to temperature variation. These results are expected to provide a new option for the regulation design of DNA composite materials and microbeam sensors. Packing patterns play a key role in thermoelastic properties of DNA adsorption films and detection signals of microcantilevers. By constructing multiscale relations between DNA mesoscopic free energy and continuum microcantilever deformation, resonant frequency shift, the influence of packing patterns on thermoelastic properties of DNA adsorption films and detection signals of microcantilevers is investigated. Compared with the convex-packaged DNA adsorption film, the concave-packaged one endows a stronger dynamic biodetection signal, whereas a weaker response to ambient temperature variation due to a larger adjustable range of thermoelastic property. [ABSTRACT FROM AUTHOR]

We report on measurements and analysis of telegraph noise of acoustoelectric current induced the surface acoustic waves-based single-electron-transport devices at 1.7 K. Trapping and detrapping electrons in the defect are considered as the physical origin of random telegraph noise. A theoretical model is designed by regarding the impurity potential as the coulomb potential of point charge. And the transitions of different metastable states in the course of measuring current could be well explained by this simplified model. Furthermore, our experimental data indicate that the current noises gradually decrease and finally vanish with the increase of radio frequency (RF) power. Therefore, the RF power in the interdigital transducer could well modulate the amplitude of telegraph noise. [ABSTRACT FROM AUTHOR]

New heterocyclic compound (S)-3-(4-(5-bromo-2-chlorobenzyl)phenoxy)tetrahydrofuran (1), designed by utilizing 5-bromo-2-chlorobenzoic acid (2) as the starting material, is obtained by the organic synthesis and then characterized by single crystal X-ray crystallography, 1H NMR and IR spectroscopy. In the biological study, the CCK-8 assay is performed to evaluate the inhibitory effect of the compound on SPC-A-1 human lung adenocarcinoma cells in vitro by measuring the cancer cell viability. Then, the anticancer activity of the compound is also confirmed by the in vivo xenograft experiment by measuring the mice body weight and the cancer volume. [ABSTRACT FROM AUTHOR]

Background: Esophageal squamous cell carcinoma (ESCC) is a kind of cancer with heterogeneous biological characteristics, which is affected by a complex network of gene interactions. Identification of molecular biomarkers paves the way for individualized therapy based on gene expression profiles, which can overcome the heterogeneity of ESCC. Methods: In this study, GSE20347, GSE23400 and GSE45670 datasets were retrieved from Gene Expression Omnibus (GEO) database, and the overlapping differentially expressed genes (DEGs) in three datasets were screened. Then the overlapping DEGs function was annotated by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway-enrichment analysis. The prognostic value of the top five KEGG pathway-related genes were further validated in The Cancer Genome Atlas (TCGA) database. After extensive statistical analysis, four genes (CDC25B, CXCL8, FZD6 and MCM4) were identified as potential prognostic markers. Among the four candidate genes, the prognostic value of FZD6 in ESCC patients has not been evaluated. Therefore, we finally used immunohistochemistry method to evaluate the effect of FZD6 on the prognosis of patients with ESCC. Additionally, we detected the expression level of FZD6 in ESCC cell line and normal esophageal epithelial cell line, and observed the cell viability of ESCC cell line after FZD6 knockdown. Results: The results showed that the overexpression of FZD6 predicted poor overall survival (OS) (P = 0.005) and progression-free survival (PFS) (P = 0.004) in ESCC patients. COX regression analysis showed that N stage (P = 0.026) and FZD6 expression level (P = 0.001) were independent prognostic factors of OS for ESCC patients. Furthermore, compared with normal esophageal epithelial cell line, the up-regulation of FZD6 was detected in ESCC cell line. Knockdown of FZD6 could significantly inhibit the proliferation of ESCC cells (P < 0.001). Conclusion: CDC25B, CXCL8, FZD6 and MCM4 were screened as candidate genes for prognosis assessment of patients with ESCC. The prognostic role of FZD6 in ESCC patients was confirmed in current study. [ABSTRACT FROM AUTHOR]

Micro-channels have been widely used in variety of devices including bipolar plate, micro-chemical reactor, and micro-heat pipe. Electrochemical machining (ECM) is a promising approach to manufacture such structure on metallic surface. This paper proposed a modified jet-ECM for generating micro-channels. A flexible insulated mask with micro-through-holes was covered on the head surface of a metallic nozzle. During machining, the mask on the modified nozzle was contacted with the workpiece, and the jetting electrolyte in the nozzle was divided into different machining regions by the micro-through-holes in the mask; then, the micro-channels could be generated by moving the workpiece with an effective voltage applied between the nozzle and workpiece. Compared with traditional jet-ECM, the machining region in this method could be confined by the micro-through-hole, which was efficient for generating channel in micro-scale. In addition, multiple micro-channels could be generated by using a mask with a single row of micro-through-holes rather than assembling multiple nozzles. The experimental results showed that the pulse duty cycle has a significant influence on the dimension of micro-channel, while the pulse frequency has slight influence in contrast. In addition, the material removal rate (MRR), effective material removal rate (MRRe), and current efficiency (CE) were investigated with different machining parameters. The results indicated that although MRR was increased with the increasing pulse duty cycle, both MRRe and CE were reduced, leading to a deviation between the theory and experiment. The moving speed of workpiece also has a significant influence on CE. Increasing moving speed was useful for enhancing the CE, from 0.48 to 0.66 with the moving speed increasing from 20 to 80 μm/s. Finally, several kinds of micro-channels such as multiple micro-channels, micro-reactor, and cross micro-channels were well manufactured with this method, demonstrating a flexible and efficient process. [ABSTRACT FROM AUTHOR]

Considering the model that the hydrothermal coupling moving rule of the seasonal frozen soil under freezing and thawing effect, a research was made that how deep we bury and the soil texture are to effect the rule of the diffusion and evaporation of water vapor. By monitoring the moisture content and temperature of the profile of the continuous freezing and thawing soil in region named Xiaotangshan mountain in Beijing and using the hydrothermal coupling moving model, the water transferring rule of clay and sandy loam in different depth that we buried was summarized. Many long-term field experiments showed that when frozen layer buried in a deep way was in a frozen state, the interactive movement of the water in the soil was not active and evaporated slowly. The average value of the water evaporation of clay was about 0.51 mm/day approximately and the situation of the sandy loam soil was 1.24 mm/day. By qualitative analyzing and observation, the less we buried (less than 0.8 m), the ice in the frozen soil layer got more. Besides, the density of the frozen soil layer went higher but the water barely diffused. On the contrary, with the increase of the depth, the diffusion went stronger and stronger due to the contact between the soil and the groundwater. In addition, according to the different soil texture detections, the diameter of soil particle has great influence on the diffusion of the water vapor in the soil. The diffusion rate of the water vapor in the sandy loam soil was twice than that of in clay. Other field water coupling experiments showed that, the soil moisture content was greater, soil freezing period density was larger, and soil water infiltration rate was zero. Soil evaporation was gradually decreased with the increasing of groundwater depth, and the size of soil particle would have a more obvious effect on soil water vapor diffusion and evaporation. Our research results can provide scientific basis for the buried area where contains groundwater to keep moisture in the winter and the resource content of the groundwater in Beijing and the locations in the same latitude of Beijing. This paper’s purpose was to research the law of water vapor diffusion and evaporation, with different soil texture and burial depth, so it can verify the coupled model of seasonal frozen soil water and heat migration. [ABSTRACT FROM AUTHOR]

A new caffeic acid derivative (( E)-3-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)acrylic acid, HL)) is synthesized from caffeic acid, followed by the preparation of a Cu(II) complex, [Cu(L)DMSO]·2DMSO. The structure is determined by single crystal X-ray diffraction, and the urease inhibitory activity of the complex is studied. The results show that IC of the complex is 0.56 μmol/L, which is superior to positive control acetohydroxamic acid (AHA, IC was 10.95 μmol/l), i.e., the complex has strong inhibitory activity towards urease. [ABSTRACT FROM AUTHOR]

The geometrical structures, relative electronic and magnetic properties of small AlCo (1 ≤ n ≤ 9) clusters are systematically investigated within the framework of density functional theory at the BPW91 level. The single Co doping can dramatically affect the ground state geometries of the 1 Al clusters. At the same time, the resulting geometries show that the lowest energy AlCo clusters prefer to be three dimensional structures. Here, the relative stabilities are investigated in terms of the calculated average binding energies, fragmentation energies, and second-order energy differences. Moreover, the result of the highest occupiedlowest unoccupied molecular orbital energy gaps indicates that AlCo clusters have the highest chemical stability for AlCo (1 ≤ n ≤ 9) clusters. Furthermore, the natural population analysis reveals that the charges in AlCo clusters transfer from the Al frames to the Co atom. Additionally, the analyses of the local and total magnetic moments of the AlCo clusters show that the magnetic effect mainly comes from the Co atom. [ABSTRACT FROM AUTHOR]

Much of human cooperation remains an evolutionary riddle. Coevolutionary public goods games in structured populations are studied where players can change from an unproductive public goods game to a productive one, by evaluating the productivity of the public goods games. In our model, each individual participates in games organized by its neighborhood plus by itself. Coevolution here refers to an evolutionary process entailing both deletion of existing links and addition of new links between agents that accompanies the evolution of their strategies. Furthermore, we investigate the effects of time scale separation of strategy and structure on cooperation level. This study presents the following: Foremost, we observe that high cooperation levels in public goods interactions are attained by the entangled coevolution of strategy and structure. Presented results also confirm that the resulting networks show many features of real systems, such as cooperative behavior and hierarchical clustering. The heterogeneity of the interaction network is held responsible for the observed promotion of cooperation. We hope our work may offer an explanation for the origin of large-scale cooperative behavior among unrelated individuals. [ABSTRACT FROM AUTHOR]

The electronic structure of dynamic quantum dots formed by surface acoustic waves potential and the confinement potential produced by gate voltage has been investigated within the spin-density-functional theory. We found the addition energy of this kind quantum dot in general decreases as the electron number increases, so the basic feature of the quantized acoustoelectric current with multi-plateaus can be reproduced. The addition energy needed for a second electron entering into the dynamic quantum dot is found to be about 2.21 meV, which is in good agreement with experimental estimations. Moreover, the formation of the Wigner molecule-like states is observed when the number of electrons in the dot exceeds three. By the calculated addition energy and the evolution of the electron density in the presence of a magnetic field, we also explained the influence of the magnetic field on the acoustoelectric current appeared in the experiments. [ABSTRACT FROM AUTHOR]

Crown rot (CR), caused by various Fusarium species, is a chronic wheat disease in Australia. As part of our objective of improving the efficiency of breeding CR resistant wheat varieties, we have been searching for novel sources of resistance. This paper reports on the genetic control of one of these newly identified resistant genotypes, ‘CSCR6’. A population derived from a cross between CSCR6 and an Australian variety ‘Lang’ was analyzed using two Fusarium isolates belonging to two different species, one Fusarium pseudograminearum and the other Fusarium graminearum. The two isolates detected QTL with the same chromosomal locations and comparable magnitudes, indicating that CR resistance is not species-specific. The resistant allele of one of the QTL was derived from ‘CSCR6’. This QTL, designated as Qcrs.cpi-3B, was located on the long arm of chromosome 3B and explains up to 48.8% of the phenotypic variance based on interval mapping analysis. Another QTL, with resistant allele from the variety ‘Lang’, was located on chromosome 4B. This QTL explained up to 22.8% of the phenotypic variance. A strong interaction between Qcsr.cpi-3B and Qcsr.cpi-4B was detected, reducing the maximum effect of Qcrs.cpi-3B to 43.1%. The effects of Qcrs.cpi-3B were further validated in four additional populations and the presence of this single QTL reduced CR severity by up to 42.1%. The fact that significant effects of Qcrs.cpi-3B were detected across all trials with different genetic backgrounds and with the use of isolates belonging to two different Fusarium species make it an ideal target for breeding programs as well as for further characterization of the gene(s) involved in its resistance. [ABSTRACT FROM AUTHOR]

Dysregulated expression of microRNAs (miRNAs) is associated with a variety of diseases, including colorectal cancer. By comparing more than 200 miRNAs in 13 pairs of matched colorectal cancer and normal adjacent tissue samples through qRT-PCR and microarray analysis, we found a widespread disruption of miRNA expression during colorectal tumorigenesis. In particular, among a panel of presumed targets generated by in silico analysis that may interact with these aberrantly expressed miRNAs, KRAS oncogene has been further experimentally validated as the target of miR-143. First, an inverse correlation between KRAS protein and miR-143 in vivo was found. Second, KRAS expression in Lovo cells was significantly abolished by treatment with miR-143 mimic, whereas miR-143 inhibitor increased KRAS protein level. Third, luciferase reporter assay confirmed that miR-143 directly recognize the 3′-untranslated region of KRAS transcripts. Four, Lovo cells treated with miR-143 inhibitor showed a stimulated cell proliferation, whereas miR-143 overexpression had an opposite effect. Finally, inhibition of KRAS expression by miR-143 inhibits constitutive phosphorylation of ERK1/2. Taken together, the present study provides the first evidences that miR-143 is significant in suppressing colorectal cancer cell growth through inhibition of KRAS translation.Oncogene (2009) 28, 1385–1392; doi:10.1038/onc.2008.474; published online 12 January 2009 [ABSTRACT FROM AUTHOR]

Effect of preparation methods on microstructures and microwave dielectric properties of Ba(Mg1/3Nb2/3)O3 ceramics was investigated. Ba(Mg1/3Nb2/3)O3(BMN) ceramics were prepared by the conventional mixed oxides method and the molten salt synthesis method. It was shown that the single-phase of BMN was obtained at 900 °C in the molten salt synthesis method. No single-phase BMN was obtained in the conventional mixed oxides method, although the calcining temperature was increased up to 1400 °C. BMN powders prepared by the molten salt synthesis method had better sinterability than that prepared by the conventional mixed oxides method. Because of the very different nature of the powders, different microstructures were observed. The molten salt synthesis method ceramics have a higher B-site ordering parameter ( S) and larger grain size than that of the conventional mixed oxides ceramics at same sintering temperature. The variation of Qf, ε r and τ f were also explained based on the difference in microstructures. [ABSTRACT FROM AUTHOR]

A five-step indentation scheme is proposed to extract the elastic and viscoelastic properties of polymeric materials using a sharp indenter. In the formulation, analytical solutions to the elastic-viscoelastic deformation based on the concept of "effective indenters" proposed by both Pharr and Bolshakov [Understanding nanoindentation unloading curves. J. Mater. Res. 17, 2660 (2002)] and Sakai [Elastic recovery in the unloading process of pyramidal microindentation. J. Mater. Res. 18, 1631 (2003)] were derived. Indentation experiments on polymethylmethacrylate following the five-step scheme were performed. The elastic-viscoelastic parameters were extracted by fitting the solution based on Sakai's effective indenter to the experimental results using a genetic algorithm. It was found that the solution based on Sakai's effective indenter was able to correctly extract the elastic properties. Based on this prediction and the experimental results, Pharr and Bolshakov's effective indenter profile could be determined. The extracted elastic-viscoelastic parameters using the solution based on Pharr and Bolshakov's effective indenter were independent of the reloading levels. [ABSTRACT FROM AUTHOR]

A semi-analytical approach was developed to study the creep response of a viscoelastic polymeric thin film on a hard elastic substrate under flat-ended punch indentation. This approach allows one to separate mechanical properties of the film from its substrate. To verify the approach, flat-ended punch creep indentation tests were performed to obtain the long-time viscoelastic behaviors of a polymethyl-methacrylide film overlying on an aluminum substrate. Three viscoelastic models describing the constitutive equations of the polymer film are compared in this paper. "Film-only" viscoelastic parameters were extracted by fitting with the experimental creep curves of flat-ended punch indentation. It is shown that the present approach provides an effective way to characterize the mechanical properties of a polymeric film on an elastic substrate. [ABSTRACT FROM AUTHOR]

Boron nitride (BN) nanocrystals with explosion (E) phase were prepared by a novel laser-assisted materials fabrication, i.e., pulsed-laser-induced liquid (acetone)/solid (hexagonal boron nitride bulk) interfacial reaction at normal temperature and pressure. Typical diameters of these synthesized quasi-spherical BN nanocrystals were in the range of 30 to 80 nm. Transmission electron microscopy, x-ray diffraction, and Fourier transformed infrared spectroscopy were used to identify the morphologies and structures of the synthesized nanocrystals. Additionally, we proposed the formation mechanism of cubic-BN and E-BN nanocrystals upon pulsed-laser-induced liquid/solid interfacial reaction, in which both liquid and solid were simultaneously involved. [ABSTRACT FROM AUTHOR]

Summary. RNA-dependent RNA polymerase (RdRp) is the replicase of positive-strand RNA viruses. Expression and characterization of the replicase are the first steps in the elucidation of the virus replication mechanism. We expressed nonstructural protein 5B (NS5B) of classical swine fever virus (CSFV) as a fusion protein with green fluorescent protein (GFP) in porcine kidney cells (PK-15 cells), natural host cells of CSFV. The expressed CSFV NS5B-GFP fusion protein possessed RdRp activity. By fluorescence microscope it was observed that the density of the fusion protein near cytoplasmic membranes was higher than that in other parts of cells. This was in contrast to the distribution of the GFP alone which was uniformly distributed throughout the cytoplasm. The GFP is a signal for the location of NS5B in a host cell that allows in vitro and in vivo investigation of the distribution of plus-strand RNA virus RdRp. [ABSTRACT FROM AUTHOR]

Many deltas are likely undergoing net erosion because of rapid decreases in riverine sediment supply and rising global sea levels. However, detecting erosion in subaqueous deltas is usually difficult because of the lack of bathymetric data. In this study, by comparing bathymetric data between 1981 and 2012 and surficial sediment grain sizes from the Yangtze subaqueous delta front over the last three decades, we found severe erosion and significant sediment coarsening in recent years since the construction of Three Gorges Dam (TGD), the largest dam in the world. We attributed these morphological and sedimentary variations mainly to the human-induced drastic decline of river sediment discharge. Combined with previous studies based on bathymetric data from different areas of the same delta, we theorize that the Yangtze subaqueous delta is experiencing overall (net) erosion, although local accumulation was also noted. We expect that the Yangtze sediment discharge will further decrease in the near future because of construction of new dams and delta recession will continue to occur. [ABSTRACT FROM AUTHOR]

An analytical solution was derived for the indentation of a cell using atomic force microscopy. It was found that the contribution of the cell membrane to the overall indentation stiffness is dependent on the size of the indenter. When a small indenter [for example, an atomic force microscopy (AFM) tip] is used to probe the mechanical properties of cells, the cell membrane and its prestress were important in interpreting indentation data. The solution allows the partition of contributions from the membrane and the interior soft phase. The apparent elastic modulus of the cell and the prestress of the cell membrane can be extracted. In addition, the modulus of the cell membrane could be estimated from the extracted apparent modulus if the interior soft phase of the cell was known and vice versa. However, when a large indenter is used (for example, a microbead attached to the cantilever beam of the AFM), the contribution of the cell membrane is negligible. [ABSTRACT FROM AUTHOR]

A new approach is proposed to extract the elastic and viscoelastic properties of a polymeric film on a hard substrate using a sharp indentation relaxation test. In the theoretic formulation, a sharp indentation relaxation test on a film/substrate system was interpreted by its equivalent flat-ended punch indentation relaxation test. The radius of the equivalent flat-ended punch was determined by the residual depth of the sharp indentation. A semi-analytical solution for a flat-ended punch relaxation test was derived. Sharp indentation relaxation tests on a polymethyl methacrylate film and a polycarbonate film on a glass substrate were performed. The semi-analytical solution and the experimental results were used to extract the elastic-viscoelastic parameters of the films. The extracted elastic-viscoelastic parameters of both films were found to be in a good agreement with data sheets of the films. The proposed approach provides a simple and yet feasible way to extract "film-only" elastic and viscoelastic properties. [ABSTRACT FROM AUTHOR]