Search

Breaches of tailings dams have had catastrophic consequences in the mining industry worldwide. Therefore, the characteristics of tailings and their effects on the stability of tailings dams need to be investigated. In this paper, the mechanical properties of uniform tailings and smaller sedimentary tailings are analyzed in laboratory testing. The critical hydraulic gradient of tailings is explored and a tailings dam model is constructed. The results of testing indicate that the strength of tailings gradually decreases with an increase in the content of fine particles smaller than 0.075 mm. The critical content of fine particles is 35% fine particles smaller than 0.075 mm. The strength, cohesion, and internal friction angle of uniform tailings are greater than those of smaller sedimentary tailings. The critical hydraulic gradient decreases with an increase in the content of fine particles smaller than 0.075 mm, and the critical content of fine particles is again approximately 35%. However, the critical hydraulic gradient of smaller sedimentary tailings is higher than that of uniform tailings. An equation is presented to calculate the critical hydraulic gradient of tailings. The seepage failure of the tailings dam can be divided into four parts. An equation is presented to calculate the critical hydraulic gradient of a tailings dam. [ABSTRACT FROM AUTHOR]

Abstract—The paper considers the problem of optimal control of an electric propulsion spacecraft maneuvering between the spatial halo orbits around the L2 libration point in the Earth−Moon system. The proposed methodology finds the initial approximations for calculating the transfer trajectories within the framework of restricted three-body problem and improves the computational efficiency of calculations. A low-thrust transfer between the halo orbits is calculated to confirm the validity of this computational procedure. [ABSTRACT FROM AUTHOR]

Schizochytrium sp. is a marine fungus, which usually lives in the salinity of 40–100% seawater and has unique salt tolerance characteristics. In this study, we explored the candidate mitogen-activated protein kinase (MAPK) related to the salt-tolerant regulatory network from Schizochytrium sp. Firstly, 6 potential MAPK genes from Schizochytrium sp. were identified based on the genome information and bioinformatics analysis. Then, the MAPK gene expression of Schizochytrium sp. under different cultivation conditions locked two genes encoding Mpk6315 and Mpk2022. Furthermore, overexpressing of Mpk6315 in S. cerevisiae enhanced cell growth by 62% while and Mpk2022 overexpression improved the membrane integrity under different stress conditions, indicating that Mpk6315 might play an important role for cell growth and Mpk2022 could help cells to encounter different environmental stressors. This study was the first time to identify the MAPK genes from Schizochytrium sp., which could enlarge the MAPK modules of salt stress tolerance and provide new elements for improving the stress resistance of other microorganisms. [ABSTRACT FROM AUTHOR]

We studied the effect of fibroblast growth factor receptor 3 (FGFR3) inhibitor BGJ-398 on the differentiation of bone marrow mesenchymal stem cells (BM MSC) into osteoblasts in wild type (wt) mice and in animals with mutation in TBXT gene (mt) and possible differences in the pluripotency of these cells. Cytology tests showed that the cultured BM MSC could differentiate into osteoblasts and adipocytes. The effect of different BGJ-398 concentrations on the expression of FGFR3, RUNX2, SMAD1, SMAD4, SMAD5, SMAD6, SMAD7, and SMAD8 were studied by quantitative reverse transcription PCR. The expression of RUNX2 protein was evaluated by Western blotting. BM MSC of mt and wt mice did not differ in pluripotency and expressed the same membrane marker antigens. BGJ-398 inhibitor reduced the expression of FGFR3 and RUNX2. In BM MSC from mt and wt mice have similar gene expression (and its changing) in FGFR3, RUNX2, SMAD1, SMAD4, SMAD5, SMAD6, SMAD7, and SMAD8 genes. Thus, our experiments confirmed the effect of decreased expression of FGFR3 on osteogenic differentiation of BM MSC from wt and mt mice. However, BM MSC from mt and wt mice did not differ in pluripotency and are an adequate model for laboratory research. [ABSTRACT FROM AUTHOR]

A substructure hybrid test is an effective approach to reproduce the seismic behavior of engineering structures. The structure is partitioned into several substructures; those with complex behavior are analyzed experimentally, whereas the others are analyzed numerically, combining the merits of physical experiments and numerical simulations. Previous studies often loaded physical substructures in two or three translational directions. Simultaneous rotational loading in three Cartesian axes is difficult because the load testing device has to be configured spatially, resulting in control problems due to strong coupling. Special expertise in mechanical engineering is necessary to solve this problem. To this end, this study proposes an integrated load testing device suitable for physical loading in all six degrees-of-freedom simultaneously. The device is based on a Stewart platform and can provide a large axial force required by most gravity-bearing components. It also has a large inherent stiffness necessary to obtain the force-displacement curve from damage through complete failure. This paper describes the force-displacement mixed control based on the Stewart configuration, which is necessary for testing engineering structures. Control software is developed and interfaced with the mid-ware OpenFresco to coordinate the numerical substructure. A hybrid test is conducted using a small-scale, electronic-driven load testing device. The test ran smoothly without any malfunctions, demonstrating the excellent performance of the testing system. [ABSTRACT FROM AUTHOR]

Using the gravimetric method the adsorption characteristics of SAPO-34 zeolite and silica gel to water vapor in vacuum condition have been experimentally studied. Comparisons of the result in vacuum condition to the result in moist air condition were carefully conducted. It was found that the equilibrium adsorption concentration of the two materials in vacuum condition was higher than the equilibrium concentration in moist air under the same condition. Also, the adsorption time to reach the equilibrium state was greatly shortened in vacuum cases. The maximum time shortening was up to 48.1% for the SAPO-34 zeolite and 38.8% for the silica gel as compared to the time of the moist air cases. With an anti-S type of the adsorption isotherm curve the concentration change of the SAPO-34 zeolite was insensitive in the middle pressure range, while the concentration change of the silica gel was more sensitive in the middle pressure range with a S type isotherm curve. The existing Freundlich equation and S-B-K equation did not fit well the adsorption isotherm of the SAPO-34 zeolite and the silica gel. Therefore novel correlations were proposed and they fitted the experimental data with much better accuracy. [ABSTRACT FROM AUTHOR]

Water buffalo (Bubalus bubalis) is an important livestock species in developing countries due to its contribution to meat, milk production, and a certain form of labor. However, the genetic potential of buffalo milk production traits has not been fully exploited. To date, 516 candidate genes associated with milk production traits of buffalo have been identified. The present study aimed to explore the possible molecular mechanisms underlying milk production traits of this species through functional genomics analysis of these candidate genes by using different bioinformatics tools. Gene ontology (GO) analysis indicated that these candidate genes were associated with complex biological processes, such as cell proliferation and mitotic nuclear division. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis demonstrated that these candidate genes were enriched in multiple signaling pathways, such as AMPK, ErbB, Toll-like receptor, and Jak-STAT. In addition, one function module consisting of 57 nodes and 139 edges were identified from the protein-protein interaction (PPI) network. GO analysis showed that the 57 candidate genes in this function module were enriched in three main biological processes, including homeostasis, metabolism, and cell response. These three distinct biological processes are well known for regulating mammary gland activities, which explained clearly the mechanism underlying milk production traits. This study provides a novel perspective for better understanding of the biological processes linked with milk production traits. This knowledge is conducive to the improvement of milk yield and composition of this species. [ABSTRACT FROM AUTHOR]

Eutectic 63Sn-37Pb solder is a typical viscoplastic material widely used in aerospace applications. In order to benchmark the mechanical reliability of electronic packaging structures in harsh environments, this study focused on the constitutive behavior of the solder. A unified creep-plasticity constitutive model is proposed with an enriched flow rule to satisfactorily describe the plastic and hardening stages. The strain rate range of 10-4 and 10-2 s-1 and the temperature range of -55 and 125°C are covered by a series of comprehensive uniaxial tensile experiments. Moreover, the experimental results are analyzed to elucidate the underlying mechanism of the calibrated parameters. It is found that the drag strength increases with temperature, while its slope is reduced with the strain rate. The short range of back stress is closely associated with temperature to influence the hardening slope of the stress–strain relationships. The value of hardening exponent is sensitive to strain rate and thus determined to be 0.52 and 2.72 for the strain rate greater and less than 2·10-4 s-1, respectively. The strain rate and temperature ranges in this study are capable of covering the temperature cycling tests for reliability qualification of electronic devices. Thus, the proposed enhancement of the unified creep-plasticity constitutive model facilitates the finite element simulations of packaging structures under temperature cycling conditions. This framework of the proposed constitutive model is readily extended to other types of viscoplastic solders within wide strain rate and temperature ranges. [ABSTRACT FROM AUTHOR]

The alternating current (AC) corrosion behavior of X80 steels annealed for different times was investigated in an alkaline soil simulation solution by electrochemical measurement, immersion test and surface analysis technology. The results show that with or without AC interference, the steels annealed for various times have different corrosion resistance. The anticorrosion resistance of steel improves with an increase in annealing time. AC interference results in the evolution of the main cathodic reaction, and facilitates the corrosion of the steels. The steel annealed for 20 min presents a more severe corrosion degree with distinct pits. The corrosion behavior of the steels annealed for different times with AC application is closely related to the microstructure. A decrease in pearlite reduces the number of galvanic corrosion cells, decreasing the corrosion rate of steel. And the grain increase is beneficial for improving the corrosion resistance of the annealed steel. [ABSTRACT FROM AUTHOR]

Corrosion behavior of X65 pipeline steels with different microstructures under alternating current (AC) interference was investigated in acid soil simulation solution by potentiodynamic polarization curve, potentiostatic polarization curve and immersion test. The results show that superimposed AC causes a sharp increase in corrosion current density of X65 steel. With the increase in iAC, the corrosion current densities of steels with various microstructures increase, especially at high iAC. Hot-rolled steel mainly experiences uniform corrosion, with very slight pit corrosion. Serious corrosion degrees with intensive corrosion pits can be observed on the surfaces of normalized and quenched microstructure steels. The annealed steel exhibits the feature of non-uniform corrosion with some pitting. The steels with various microstructures applied with AC have different corrosion resistance. The normalized steel shows the worst corrosion resistance, then the quenched microstructure, and the hot-rolled steel displays the optimum corrosion resistance. The difference in the microstructure can result in difference in corrosion degree and occurrence position of pitting corrosion of X65 steel. The normalized microstructure composed of polygonal ferrite and a large amount of pearlite and bainite is the most susceptible to AC corrosion. [ABSTRACT FROM AUTHOR]

Concrete is a type of quasi-brittle material with high compressive strength and low tensile strength. To obtain the complete tensile stress-deformation curve of massive concrete specimens, a specially designed loading machine is proposed with a pair of hydraulic oil dampers parallel to the direction of the tensile loading. The dampers were designed with valves to modify the stiffness of the loading machine, enhancing the stiffness of the machine before the applied stress reaches 90% of the ultimate stress of the concrete. Several experiments were conducted with the proposed loading machine on prism-shaped specimens (size: 1350 mm× 450 mm × 450 mm), and the stress-deformation curves and mechanical parameters of the concrete were obtained. Finally, an empirical formula is presented and compared with the experimental results. [ABSTRACT FROM AUTHOR]

Complex plasmas are low temperature plasmas that contain microparticles in addition to ions, electrons, and neutral particles. The microparticles acquire high charges, interact with each other and can be considered as model particles for effects in classical condensed matter systems, such as crystallization and fluid dynamics. In contrast to atoms in ordinary systems, their movement can be traced on the most basic level, that of individual particles. In order to avoid disturbances caused by gravity, experiments on complex plasmas are often performed under microgravity conditions. The PK-3 Plus Laboratory was operated on board the International Space Station from 2006 - 2013. Its heart consisted of a capacitively coupled radio-frequency plasma chamber. Microparticles were inserted into the low-temperature plasma, forming large, homogeneous complex plasma clouds. Here, we review the results obtained with recent analyzes of PK-3 Plus data: We study the formation of crystallization fronts, as well as the microparticle motion in, and structure of crystalline complex plasmas. We investigate fluid effects such as wave transmission across an interface, and the development of the energy spectra during the onset of turbulent microparticle movement. We explore how abnormal particles move through, and how macroscopic spheres interact with the microparticle cloud. These examples demonstrate the versatility of the PK-3 Plus Laboratory. [ABSTRACT FROM AUTHOR]

Twenty-five resveratrol derivatives were synthesized, among which eight compounds have not yet been reported. The target compounds were evaluated for thrombin inhibitory activity in vitro (IC50). The results showed that four compounds displayed a better thrombin inhibitory activity with IC50 values from 10.43 to 18.31 μM, better than resveratrol (25.87 μM). The R3 position of resveratrol was modified by heterocyclic rings containing oxygen and sulfur, which could increase the anticoagulant activity of resveratrol. [ABSTRACT FROM AUTHOR]

We proposed a mesh-free method, the called node-based smoothed point interpolation method (NS-PIM), for dynamic analysis of rotating beams. A gradient smoothing technique is used, and the requirements on the consistence of the displacement functions are further weakened. In static problems, the beams with three types of boundary conditions are analyzed, and the results are compared with the exact solution, which shows the effectiveness of this method and can provide an upper bound solution for the deflection. This means that the NS-PIM makes the system soften. The NS-PIM is then further extended for solving a rigid-flexible coupled system dynamics problem, considering a rotating flexible cantilever beam. In this case, the rotating flexible cantilever beam considers not only the transverse deformations, but also the longitudinal deformations. The rigid-flexible coupled dynamic equations of the system are derived via employing Lagrange’s equations of the second type. Simulation results of the NS-PIM are compared with those obtained using finite element method (FEM) and assumed mode method. It is found that compared with FEM, the NS-PIM has anti-ill solving ability under the same calculation conditions. [ABSTRACT FROM AUTHOR]

The dynamic characteristics of SAPO-34 and ZSM-5 zeolite in the desorption process have been experimentally studied with the gravimetric method. The weight change of the test sample was recorded continually for different conditions of temperature and pressure. The curve of the desorption degree with the temperature and the pressure was obtained and discussed. With the intrinsic different micro-structure, the two zeolites showed distinguished characteristics of the desorption. In contrast to an S-shaped desorption curve of the SAPO-34, the ZSM-5 showed an exponential desorption curve. In comparison, the desorption characteristics of the ZSM-5 were better than that of the SAPO-34 in the temperature range of 40 °C ~ 90 °C. Nevertheless, the effect of the pressure on the desorption degree was stronger for the SAPO-34 than for the ZSM-5. Further analysis revealed that the desorption speed was affected more strongly by the temperature than by the pressure. [ABSTRACT FROM AUTHOR]

For both single-phase and multiphase metallic materials, it is necessary to understand the mechanical behavior on the grain-size scale in detail to get information that is not obtainable from macro-scale mechanical characterizations. This paper presents a methodology for uniaxial tensile testing of micro-specimens isolated from a bulk material. The proposed concept of multiple parallel micro-tensile specimens at the tip of a macro-sized wedge reduces the alignment work and offers an easy way for specimen handling. The selection of site-specific specimens is based on detailed microstructural and crystallographic characterization. Three kinds of representative specimens are presented to illustrate the wide range of application of the methodology for a variety of materials. Accurate, reproducible measurement of force (2.5 μN resolution) and displacement (~10 nm resolution) is demonstrated, while accurate alignment (in-plane rotational and out-of-plane tilt misalignment of <0.2°) limits the stress due to bending to <0.2% of the imposed uni-axial stress. Combined with detailed material characterization on both sides of the micro-specimens, this method yields detailed insights into the micro-mechanics of bulk materials which is hard to obtain from traditional macro-mechanical tests. [ABSTRACT FROM AUTHOR]

The effect of short-term drought stress on the water content, antioxidant system and photosynthetic characteristics was investigated using cucumber ( Cucumis sativus L.) seedlings. The results indicated that polyethylene glycol induced water stress reduced water content in shoots of cucumber seedling after treatment of 36 hours, and caused obvious reductions in net photosynthetic rate, stomatal conductance, intercellular CO concentration and transpiration of leaves. In addition, water stress significantly reduced the photosynthetic pigment content and inhibited photochemical activity, including actual photochemical efficiency, maximal quantum yield of photosystem II photochemistry and coefficient for photochemical quenching. Meanwhile non-photochemical quenching increased. As responses to drought stress, significant increases in electrolyte leakage, malondialdehyde, superoxide anion and hydrogen peroxide levels were detected in leaves. The superoxide dismutases, catalase, glutathione reductase and dehydroascorbate reductase activities, protein, ascorbate and glutathione content, all decreased and peroxidases activity increased, while ascorbate peroxidase and monodehydroascorbate reductase activities exhibited different trend under different degree of water stress. Therefore, it can be concluded that water stress strongly disrupted the normal metabolism of leaves and restrained water absorption. [ABSTRACT FROM AUTHOR]

The corrosion behavior and laws of the west-east gas pressure pipeline of L415 steel were studied in simulated leaching liquid. The failure of the L415 steel during the pressure testing process was investigated using electrochemical polarization, electrochemical impedance spectroscopy, and immersion test. The corrosion rate of the L415 steel increased with ion concentration in the leaching liquid. This rate reached about 0.8 mm a and belonged to the severe corrosion grade. Pitting corrosion was observed in various simulated solutions with different aggressive species concentrations. The original ion concentration in the leaching liquid (1×) is the key factor influencing pitting initiation and development. Pitting showed easy nucleation, and its growth rate was relatively slow, in the basic simulating solution of the leach liquid (i.e., the ion content is compactable to the real condition in the rust on the inner steel pipe surface). Pitting was also highly sensitive and easily grew in the solution with doubled ion concentration in the basic simulating solution (2×). A uniform corrosion, instead of pitting, mainly occurred when the ion concentration was up to 10× of the basic solution. [ABSTRACT FROM AUTHOR]

In this work, the macro adsorption characteristic of water vapor by the allochroic silica gel and the zeolite 5A and ZSM-5 were investigated experimentally. BET analysis method presented the difference of the porosity, the micro pore volume, and the specific surface area of the material. The dynamic and the equilibrium characteristics of the sample were measured thermo-gravimetrically in the moist air. In general, the ZSM-5 zeolite showed an inferior feature of the adsorption speed and the equilibrium concentration to the others. By comparison to the result of SAPO-34 zeolite in the open literature, the 5A zeolite showed some superiorities of the adsorption. The equilibrium concentration of the ZSM-5 zeolite was higher than that of the SAPO-34 calcined in the nitrogen, whereas it was lower than that calcined in the air. The adsorption isotherm was correlated and the relation of the isotherm to the microstructure of the material was discussed. With more mesopore volume involved, the zeolite presented an S-shaped isotherm in contrast to the exponential isotherm of the silica gel. In addition, the significance of the S-shaped isotherm for the application in adsorption heat pump has also been addressed. [ABSTRACT FROM AUTHOR]

The aim of the study was to expand the substrate scope of Gliocladium deliquescens NRRL 1086 and generate coumarin glycosides using 4-methylumbelliferone (4-MU) as a substrate. The obtained results indicated that 4-MU can be metabolized to its glucoside (M1) and sulfate conjugate (M2), and the structures of the metabolites were elucidated by spectroscopic or enzymatic methods. Time course experiments detected that nearly 90% of 4-MU could be metabolized within 24 h, and the maximum yield of M1 could reach as high as 32%. Further tests revealed that the glucose concentration in the medium had little effect on the yield of M1 but time of 4-MU-adding could markedly affect the glycosylation procedure, and the favorable time to accumulate M1 was in the 12 or 24 h-old stage II culture, while in the 36 h-old or even older stage II culture, the substrate was almost metabolized to M2. The attempts to alter the ratio between M1 and M2 were performed by addition of quercetin and S-tetrahydroberberrubine or reduction of the sulfate concentration in the culture medium. Herein we describe, to the best of our knowledge, the first example of simultaneously microbial glycosylation and sulfation of coumarins. [ABSTRACT FROM AUTHOR]

In this work, the corrosion behavior of X80 pipeline steel at various frequencies AC was investigated in carbonate/bicarbonate solution using the polarization curve, EIS test, Mott-Schottky curve and immersion tests. A new understanding on AC corrosion of the steel in alkaline environment is proposed. Decreasing AC frequency negatively shifts the corrosion potential and increases the corrosion rate of steel, as well as corrosion pits occur more readily. The superimposed AC shifts the critical pitting potential negatively and degrades the passivity of the steel. AC reduces the compactness and uniformity of the passive film formed on the steel and increases the possibility of the breakdown of the film, as well decreases the film thickness. The application of AC could prevent the passive film forming on the surface of X80 steel and result in a destructive effect on the film formed on the steel surface, especially at the low-frequency AC. [ABSTRACT FROM AUTHOR]

The corrosion behavior and mechanism of E690 high-strength steel in marine environment with different pH values were studied through electrochemical technology and long-term alternating wet-dry cycle experiments combined with SEM and XRD. Results showed that the corrosion current density of E690 high-strength steel gradually increased with decreased pH. After long-term tests in alternating wet-dry marine environment with various pH values, uniform corrosion mainly occurred on E690 steel, accompanied by vast corrosion pitting. Weight loss analysis demonstrated that corrosion rate decreased with increased pH. Moreover, corrosion mechanism varied with pH, and hydrogen-evolution reaction greatly increased the E690 steel corrosion rate at low pH. Meanwhile, the compositions of corrosion products slightly differed with pH; these products consisted of FeO, FeO, α-FeOOH, β-FeOOH, γ-FeOOH, and amorphous substances. However, the rust-layer density varied. Cr in the rust layer promoted the densification of rust layer and improved the decay resistance of E690 steel. [ABSTRACT FROM AUTHOR]

In this work, effects of pH value on the electrochemical and stress corrosion cracking (SCC) behavior of X70 pipeline steel in the dilute bicarbonate solutions were investigated using electrochemical measurements, slow strain rate tensile tests and surface analysis techniques. Decrease of the solution pH from 6.8 to 6.0 promotes the anodic dissolution and cathodic reduction simultaneously. Further decrease of the pH value mainly accelerates the cathodic reduction of X70 pipeline steel. As a result, when the solution pH decreases form 6.8 to 5.5, SCC susceptibility decreases because of the enhancement of the anodic dissolution. When the solution pH decreases from 5.5 to 4.0, SCC susceptibility increases gradually because of the acceleration of cathodic reactions. [ABSTRACT FROM AUTHOR]

MCPH1, also known as BRIT1, has recently been identified as a novel key regulatory gene of the DNA damage response pathway. MCPH1 is located on human chromosome 8p23.1, where human cancers frequently show loss of heterozygosity. As such, MCPH1 is aberrantly expressed in many malignancies, including breast and ovarian cancers, and the function of MCPH1 has been implicated in tumor suppression. However, it remains poorly understood whether MCPH1 deficiency leads to tumorigenesis. Here we generated and studied both Mcph1−/− and Mcph1−/−p53−/− mice; we showed that Mcph1−/− mice developed tumors with long latency, and that primary lymphoma developed significantly earlier in Mcph1−/−p53−/− mice than in Mcph11+/+p53−/− and Mcph1+/−p53−/− mice. The Mcph1−/−p53−/− lymphomas and derived murine embryonic fibroblasts (MEFs) were both more sensitive to irradiation. Mcph1 deficiency resulted in remarkably increased chromosome and chromatid breaks in Mcph1−/−p53−/− lymphomas and MEFs, as determined by metaphase spread assay and spectral karyotyping analysis. In addition, Mcph1 deficiency significantly enhanced aneuploidy as well as abnormal centrosome multiplication in Mcph1−/−p53−/− cells. Meanwhile, Mcph1 deficiency impaired double strand break (DSB) repair in Mcph1−/−p53−/− MEFs as demonstrated by neutral Comet assay. Compared with Mcph1+/+p53−/− MEFs, homologous recombination and non-homologous end-joining activities were significantly decreased in Mcph1−/−p53−/− MEFs. Notably, reconstituted MCPH1 rescued the defects of DSB repair and alleviated chromosomal aberrations in Mcph1−/−p53−/− MEFs. Taken together, our data demonstrate MCPH1 deficiency promotes genomic instability and increases cancer susceptibility. Our study using knockout mouse models provides convincing genetic evidence that MCPH1 is a bona fide tumor suppressor gene. Its deficiency leading to defective DNA repair in tumors can be used to develop novel targeted cancer therapies in the future. [ABSTRACT FROM AUTHOR]

The crack propagation behavior of pipeline steels with or without AC application was studied in high pH solution using the crack propagation experiment (cyclic load). The results show that there is a significant difference in the crack propagation behavior of steels with or without AC interference. The crack growth rate (CGR) of steel under superimposed AC is considerably greater than that without AC. AC could cause an obvious effect on the crack propagation behavior, and enhance the CGR. The crack propagation behavior of steel under AC application in high pH solution is analogous to that in near-neutral pH solution. [ABSTRACT FROM AUTHOR]

Dopamine signaling in nucleus accumbens is essential for cocaine reward. Interestingly, imaging studies have reported blunted dopamine increases in striatum (assessed as reduced binding of [11C]raclopride to D2/D3 receptors) in detoxified cocaine abusers. Here, we evaluate whether the blunted dopamine response reflected the effects of detoxification and the lack of cocaine-cues during stimulant exposure. For this purpose we studied 62 participants (43 non-detoxified cocaine abusers and 19 controls) using positron emission tomography and [11C]raclopride (radioligand sensitive to endogenous dopamine) to measure dopamine increases induced by intravenous methylphenidate and in 24 of the cocaine abusers, we also compared dopamine increases when methylphenidate was administered concomitantly with a cocaine cue-video versus a neutral-video. In controls, methylphenidate increased dopamine in dorsal (effect size 1.4; P<0.001) and ventral striatum (location of accumbens) (effect size 0.89; P<0.001), but in cocaine abusers methylphenidate's effects did not differ from placebo and were similar whether cocaine-cues were present or not. In cocaine abusers despite the markedly attenuated dopaminergic effects, the methylphenidate-induced changes in ventral striatum were associated with intense drug craving. Our findings are consistent with markedly reduced signaling through D2 receptors during intoxication in active cocaine abusers regardless of cues exposure, which might contribute to compulsive drug use. [ABSTRACT FROM AUTHOR]

This paper is a continuation of a previous paper titled 'A novel way to calculate energy efficiency for rechargeable batteries' published on Journal of Power Sources/2012 describing a new method to calculate energy efficiency for rechargeable batteries. The present paper further describes the application of energy efficiency model on the evaluation of fuel consumption and emission for the heavy-duty hybrid electric vehicles (HD-HEVs). A more accurate calculation method of net energy change for power battery pack is proposed based on energy efficiency model of power battery pack. A more simplified and accurate correction method of fuel consumption and emission is also presented based on equivalent mileage. The fuel consumption and emission on chassis dynamometer are measured in the HD-HEVs. The experiment results show that relative errors of fuel consumption and emission between equivalent mileage correction results and linear regression correction results are less than 3%, which verifies accuracy and validates the proposed evaluation method for HD-HEVs fuel consumption and emission. [ABSTRACT FROM AUTHOR]

We investigated the effects of exogenous sodium nitroprusside (SNP), a nitric oxide (NO) donor, on growth of cucumber ( Cucumis sativus L., cv. Jinyou No.1) seedlings and antioxidant enzyme activities in cucumber leaves under waterlogging stress. The growth of cucumber seedlings was significantly inhibited when plants were exposed to waterlogging, whereas shoot spraying with SNP significantly alleviated the inhibition of growth from this type of stress: height, fresh and dry weights of the flooded plants increased obviously. Waterlogging also caused the activation of the antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX)), the reduction of the chlorophyll content, and the accumulation of MDA and protein in leaves. It was found that SNP treatment further potentiated the antioxidant enzyme activities and maintained the chlorophyll and protein content during the entire water-logging period; however, it reduced the MDA content. Thus, NO protects plants from oxidative damage and promotes growth by activation of antioxidant enzymes in leaves in an extent sufficient for the alleviation of membrane injury. However, exogenous NO had no significant effects on cucumber seedlings growth and antioxidant enzyme activities under nonstress conditions. [ABSTRACT FROM AUTHOR]

The electrochemical and sulfide stress corrosion cracking (SSCC) behaviors of 13Cr stainless steel and P110 steel were investigated in a simulated acidic annular environment with low-temperature and high-pressure HS/CO using electrochemical methods, U-bend immersion tests, and scanning electron microscopy. In the solution containing high pressure CO, 13Cr, and P110 steels exhibited general corrosion and severe pitting, respectively. Compared with sweet corrosion, additional HS in the solution enhanced the corrosion of 13Cr steel but inhibited the corrosion of P110 steel. By contrast, in a solution containing 4 MPa CO and different $$ {P}_{{{\text{H}}_{ 2} {\text{S}}}}$$ (0-0.3 MPa), the susceptibility of both 13Cr stainless steel and P110 steel toward SSCC was significantly promoted by increases in HS partial pressure. The 13Cr stainless steel exhibited higher susceptibility toward SSCC than P110 steel under a HS/CO environment but lower susceptibility under a pure CO environment. [ABSTRACT FROM AUTHOR]

The phosphatidylinositol 3′-kinase (PI3K) pathway is dysregulated in multiple myeloma (MM); we therefore tested a highly selective class I PI3K inhibitor, GDC-0941, for anti-myeloma activity. Functional and mechanistic studies were first performed in MM cell lines, then extended to primary MM patient samples cultured in vitro. GDC-0941 was then assessed as a single agent and in various combinations in myeloma tumor xenograft models. We show p110 α and β are the predominant PI3K catalytic subunits in MM and that a highly selective class I PI3K inhibitor, GDC-0941, has robust activity as a single agent to induce cell cycle arrest and apoptosis of both MM cell lines and patient myeloma cells. Mechanistic studies revealed an induction of cell cycle arrest at G0/G1, with decreased phospho-FoxO1/3a levels, decreased cyclin D1 and c-myc expression, and an increase in the cell cycle inhibitor, p27kip. Induction of apoptosis correlated with increased expression of the pro-apoptotic BH3-only protein BIM, cleaved caspase 3 and cleaved poly (ADP-ribose) polymerase (PARP). In vitro, GDC-0941 synergized with dexamethasone (Dex) and lenalidomide (combination index values of 0.3-0.4 and 0.4-0.8, respectively); in vivo GDC-0941 has anti-myeloma activity and significantly increases the activity of the standard of care agents in several murine xenograft tumor models (additional tumor growth inhibition of 37-53% (Dex) and 22-72% (lenalidomide)). These data provide a clear therapeutic hypothesis for the inhibition of PI3K and provide a rationale for clinical development of GDC-0941 in myeloma. [ABSTRACT FROM AUTHOR]

We first introduce the notion of a right generalized partial smash product and explore some properties of such partial smash product. Based on these notions and properties, then we construct a Morita context for partial coactions of a co-Frobenius Hopf algebra. Finally, we prove that any Hopf partial Galois extension induces a unique partial entwining map compatible with the right partial coaction. [ABSTRACT FROM AUTHOR]

The 2D problem of a time-harmonic plane shear horizontal (SH) wave scattered by a finite closed crack in an isotropic material is presented in the paper. The crack is arbitrarily orientated with regard to the incident wave. A spring model based on the assumption that the traction components on the crack surfaces are linearly related to the crack opening displacement (COD) is used to model the closed crack. The problem is formulated in a set of boundary integral equations which contains the CODs as unknowns. Numerical examples are presented for the CODs, elastodynamic stress intensity factors, and the scattered displacement field for various parameters, such as spring stiffness, crack sizes and crack orientations. The results show that both the crack closure and orientation have significant effects on the scattered displacement field for the closed crack. [ABSTRACT FROM AUTHOR]

This paper investigates the stress corrosion cracking (SCC) behavior of welded API X70 pipeline steel in simulated underground water using the slow strain rate test, fractographic characterization by scanning electron microscopy, and potentiodynamic polarization techniques. SCC susceptibility of the heat-affected zone (HAZ) is demonstrated to be dependent on two factors: the effect of the microstructure in the HAZ on electrochemical reactions and the effect of the mechanical property on SCC occurrence. Electrochemical experiments indicate that the microstructures in the HAZ, especially the softened microstructure, can significantly facilitate the processes of hydrogen evolution when cathodic potential is positive to −1050 mV. However, when the cathodic potential is below −1050 mV, the cathode current densities of different microstructures are close to one another and greatly increase because of the decrease of the applied potentials. The SCC behavior is consistent with the electrochemical results. Under −650 and −850 mV, SCC is most likely to occur in the softened region, and under −1200 mV, SCC occurs in both the softened and hardened regions. [ABSTRACT FROM AUTHOR]

Emerging evidence has shown that aberrantly expressed microRNAs (miRNAs) are highly associated with tumour development and progression. However, little is known about the potential role of miRNAs in gastric cancer (GC) metastasis. In this study, miR-409-3p was found to be downregulated frequently in human GCs, and its expression was significantly associated with tumor-node-metastasis (TNM) stage and lymph node metastasis. Enforced expression of miR-409 in GC cells significantly reduced their migration and invasion in vitro and their capacity to develop distal pulmonary metastases and peritoneal dissemination in vivo. Moreover, we found that miR-409 exerted its function predominantly through the mature miR-409-3p, but not miR-409-5p. Microarray and bioinformatics analysis identified the pro-metastatic gene radixin (RDX) as a potential miR-409-3p target. Further studies confirmed that miR-409-3p suppressed the expression of RDX by directly binding to its 3′-untranslated region. Silencing of RDX by small interfering RNAs phenocopied the effects of miR-409 overexpression, whereas restoration of RDX in miR-409-overexpressed GC cells reversed the suppressive effects of miR-409. Taken together, these results demonstrate that miR-409 suppresses GC cell invasion and metastasis by directly targeting RDX and that patients with downregulated miR-409-3p are prone to lymph node metastasis. [ABSTRACT FROM AUTHOR]

Cocaine-induced stroke is among the most serious medical complications associated with its abuse. However, the extent to which acute cocaine may induce silent microischemia predisposing the cerebral tissue to neurotoxicity has not been investigated; in part, because of limitations of current neuroimaging tools, that is, lack of high spatiotemporal resolution and sensitivity to simultaneously measure cerebral blood flow (CBF) in vessels of different calibers (including capillaries) quantitatively and over a large field of view. Here we combine ultrahigh-resolution optical coherence tomography to enable tracker-free three-dimensional (3D) microvascular angiography and a new phase-intensity-mapping algorithm to enhance the sensitivity of 3D optical Doppler tomography for simultaneous capillary CBF quantization. We apply the technique to study the responses of cerebral microvascular networks to single and repeated cocaine administration in the mouse somatosensory cortex. We show that within 2-3 min after cocaine administration CBF markedly decreased (for example, ∼70%), but the magnitude and recovery differed for the various types of vessels; arterioles had the fastest recovery (∼5 min), capillaries varied drastically (from 4-20 min) and venules showed relatively slower recovery (∼12 min). More importantly, we showed that cocaine interrupted CBF in some arteriolar branches for over 45 min and this effect was exacerbated with repeated cocaine administration. These results provide evidence that cocaine doses within the range administered by drug abusers induces cerebral microischemia and that these effects are exacerbated with repeated use. Thus, cocaine-induced microischemia is likely to be a contributor to its neurotoxic effects. [ABSTRACT FROM AUTHOR]

Two new copper( II) complexes ( I, II) with benzimidazole ligands have been synthesized and characterized by elemental analysis and X-ray single-crystal diffraction. Compound I is triclinic, P $\bar 1$ , a = 11.4205(6), b = 13.0956(7), c = 18.2305(9) Å, α = 85.960(1)°, β = 80.388(0)°, γ = 77.517(1)°, V = 2623.0(2) Å, Z = 2; compound II is monoclinic, C2/ c, a = 24.2684(11), b = 17.5247(8), c = 19.3149(15) Å, β = 122.710(1)°, V = 6911.9(7) Å, Z = 4. In both compounds, Cu(II) atoms are coordinated by four benzimidazole nitrogen atoms in a slightly distorted tetrahedral fashion. [ABSTRACT FROM AUTHOR]

Two new cobalt(III) and zinc(II) complexes, [Co(L) (HO)] · ClO ( I) and [Ni(L) (HO)] · 2ClO ( II), where L is the deprotonated form of 5-methoxy-2-[(2-morpholin-4-ylethylimino)methyl]phenol, and L is the zwitterionic form of 2-[(2-isopropylaminoethylimino)methyl]-5-methoxyphenol, were synthesized and structurally characterized by elemental analyses, IR spectra, and single-crystal X-ray diffraction. The crystal of I is monoclinic: space group P2/ c, a = 11.1512(4), b = 28.2424(11), c = 10.9655(4) Å, β = 95.746(2)°, V = 3436.1(2) Å, Z = 4. The crystal of II is triclinic: space group P2/ c, a = 8.1441(2), b = 10.4531(3), c = 10.8849(3) Å, α = 84.0240(10)°, β = 76.9800(10)°, γ = 74.2280(10)°, V = 867.92(4) Å, Z = 1. Complex I consists of a mononuclear cobalt(III) complex cation and a perchlorate anion. Complex II consists of a crystallographic centrosymmetric mononuclear nickel(II) complex cation and two perchlorate anions. Each metal atom in the complexes is in an octahedral coordination. [ABSTRACT FROM AUTHOR]

The hydrogen-induced cracking (HIC) susceptibility of the X80 steel in HS environment and its heated-treatment microstructure was evaluated. The field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM) and energy dispersive spectroscopy (EDS) were employed to study the morphology and chemical composition of the inclusions, precipitates and HIC cracks in the X80 steel. The hydrogen trapping efficiency was investigated by measuring the permeability ( JL) and the apparent diffusivity ( D). The results showed that heat-treated specimens had lower trapping efficiency, but were more susceptible to HIC. Most of the HIC cracks initiated from the inclusions rich in Mn, Al, Ca, and Ti, and propagated transgranularly in the original and air cooled specimens, but mainly intergranularly in water quenched specimens. [ABSTRACT FROM AUTHOR]

We report a laser-diode-end-pumped acousto-optical Q-switched double-end diffusion-bonded Nd : YVO self-Raman laser at 1176 nm. The maximum average output power at the first-Stokes wavelength of 1176 nm was obtained to be 3.1 W at the incident pump power of 25 W and the repetition rate of 90 kHz, with the corresponding optical conversion efficiency of 12.4%. The shortest pulse width, the maximum pulse energy and the highest peak power were measured to be 5 ns, 42 μJ and 7.5 kW, respectively. [ABSTRACT FROM AUTHOR]

Antibody-drug conjugates (ADCs) are potent cytotoxic drugs linked to antibodies through chemical linkers, and allow specific targeting of drugs to neoplastic cells. The expression of CD22 is limited to B-cells, and we show that CD22 is expressed on the vast majority of non-Hodgkin's lymphomas (NHLs). An ideal target for an ADC for the treatment of NHL would have limited expression outside the B-cell compartment and be highly effective against NHL. We generated an ADC consisting of a humanized anti-CD22 antibody conjugated to the anti-mitotic agent maytansine with a stable linker (anti-CD22-MCC-DM1). Anti-CD22-MCC-DM1 was broadly effective in in vitro killing assays on NHL B-cell lines. We did not find a strong correlation between in vitro potency and CD22 surface expression, internalization of ADC or sensitivity to free drug. We show that anti-CD22-MCC-DM1 was capable of inducing complete tumor regression in NHL xenograft mouse models. Further, anti-CD22-MCC-DM1 was well tolerated in cynomolgus monkeys and substantially decreased circulating B-cells as well as follicle size and germinal center formation in lymphoid organs. These results suggest that anti-CD22-MCC-DM1 has an efficacy, safety and pharmacodynamic profile that support its use as a treatment for NHL. [ABSTRACT FROM AUTHOR]

The article focuses on a study carried out to examine the suitability of the digital image correlation (DIC) technique in the whole field sheet-metal tensile test. It states that the full-range strain distribution at the microscopic level during the tensile test was measured using the DIC system. It describes the experimental setup, and discusses the calibration process and measured results. The test shows that DIC will help in the evaluation and optimization of new materials.

The design of a Ka-band gyrotron traveling wave amplifier with high power and wide bandwidth is presented in detail. The amplifier operates in the TE11 circular mode at the fundamental cyclotron harmonic. The distributed loss technique is adopted in the interaction circuit which guarantees the amplifier zero-drive stability. The effects of the parameters such as input power, driver frequency and magnetic field on the performance of the gyro-TWT are discussed. The simulation results show that the gain and the 3dB bandwidth of the designed Ka-band gyro-TWT are about 56.0dB and 1.8 GHz ,respectively. The peak output power and the corresponding electronic efficiency are about 100 kW and 23.8% respectively with the voltage 70 kV and the current 6A at the velocity ratio 1.0. [ABSTRACT FROM AUTHOR]

We have previously shown that protein kinase D1 (PKD1), charter member of PKD protein family, is downregulated in advanced prostate cancer (PC) and influences androgen receptor (AR) function in PC cells. Other independent studies showed that serine 82 residue in heat shock protein 27 (Hsp27) undergoes substrate phosphorylation by PKD1 and is associated with nuclear transport of AR resulting in increased AR transcriptional activity. In this study, we show that PKD1 interacts and phosphorylates Hsp27 at Ser82 in PC cells, which is mediated by p38-dependent mitogen-activated protein kinase pathway and is necessary for PKD1 repression of AR transcriptional activity and androgen-dependent proliferation of PC cells. The study provides first in vivo evidence that Hsp27 is a mediator of repression of AR function by PKD1 in PC cells, thereby linking the data in the published literature. [ABSTRACT FROM AUTHOR]

Bell’s inequality in two coupled quantum dots within cavity QED, including Förster and exciton–phonon interactions, is investigated theoretically. It is shown that the environmental temperature has a significant impact on Bell’s inequality. [ABSTRACT FROM AUTHOR]

We propose a physical understanding of scattering by subwavelength grooves surrounding a single perfect conductor slit based on the superposition of a cylindrical traveling surface wave and a standing surface wave. The collective reflection coefficient was introduced to handle the multi-interaction of the surface wave between subwavelength grooves, and a slit–grooves focusing structure was designed to demonstrate its validity. In comparison to numerical simulations by the finite difference time domain method, the proposed method proves effective in describing the multi-interaction behavior of a surface wave and in further refining the phase perturbation at the grooves’ exits. [ABSTRACT FROM AUTHOR]

Corrosion of X70 steel with different heat treatments (quenching, air cooling, and furnace cooling) in an alkaline soil was investigated by weight-loss, surface characterization and electrochemical measurements. The cathodic/anodic reactions of X70 steel in alkaline soil are dominated by the oxygen reduction and formation of iron oxides that deposit on the steel surface. The protection of the oxide deposit is through a physical block effect. The deposit layer formed on as-received steel has a compact, complete structure and thus, provides an effective protection over the underneath steel. However, the deposit layers on the heat-treated steels are generally loose, porous and defective, and provide minor protectiveness. Corrosion of steel is affected by its microstructure. Generally, steels with heat treatments have a higher corrosion rate than the as-received steel. The presence of more pearlite enhances the corrosion rate of ferrite by a galvanic effect. When the steel contains bainite and martenite phases, the activity of the steel is further increased. [ABSTRACT FROM AUTHOR]

The electrochemical corrosion characteristics of carbon steel in a salty soil at different temperatures were studied by measurements and analyses of potentiodynamic polarization curves, linear polarization resistance and electrochemical impedance spectroscopy. The results showed that the mass-transfer of dissolved oxygen plays an essential role in carbon steel corrosion, and the whole corrosion process is mix-controlled by both activation and mass-transfer steps. Passivity can be developed on carbon steel in the soil at low temperatures. With the increase of temperature, the passive current density increases and the passive potential range decreases. When temperature is elevated to a certain value, 50 °C in this system, passivity cannot be maintained and the steel is dominated by an active dissolution status. Anodic Tafel slope decreases continuously with the increase in temperature, which is mainly due to the enhanced electrode reaction rate at an elevated temperature. Simultaneously, cathodic Tafel slope increases with temperature continuously due to the decrease of the solubility of dissolved oxygen in soil. Since the diffusion activation energy is generally much smaller than the reaction activation energy, the effect of temperature on diffusion is far less than that on electrode reaction rate. [ABSTRACT FROM AUTHOR]

The authors theoretically demonstrate the terahertz beam shaping with metallic subwavelength holes array surrounded by concentric periodic grooves. High transmission and directional radiation can be obtained simultaneously for the resonant excitation of the surface wave in the combined structure. Finite-difference time-domain simulation results shows that the transmission mainly depends on the lattice constant of hole array and the features of incident surface around it, while the far-field angle distribution is dominated by the details of the output surface. This compact beam shaping structure is hoped to serve as a basic device for future terahertz systems. [ABSTRACT FROM AUTHOR]