Search

A well-designed carbon nanosphere functionalized with bimetallic Fe–Co phosphides (Fe–Co–P@C) was prepared, which modifies the separator to inhibit the diffusion of polysulfide by the physical restriction and chemical absorption and reduces the shuttle effect. Meanwhile, this elaborated separator with large surface area and porosity can not only provide sufficient active sites for the conversion of polysulfide, but also enhance polarity and electron conductivity which is conducive to accelerate Li+ ion/e– diffusion. As a result, the assembled lithium sulfur battery with the Fe–Co–P@C membrane displays a remarkable discharge capacity of 1031 mAh/g at 0.2 C and an excellent cycling stability (45% retention rate after 250 cycles at 1 C). [ABSTRACT FROM AUTHOR]

We show that certain extension results obtained by Maz'ya and Poborchi for domains with an outward peak can be realized via composition operators generated by reflections. We also study the case of the complementary domains. [ABSTRACT FROM AUTHOR]

Comminution is widely used in the deep processing of coal resources. Different chemical structures in coals can influence follow-up procedures significantly. A planetary ball mill was used as a comminution device, and its effects on the grain size and chemical structure of anthracite from Ningxia, China were studied. Comminution kinetics were studied and qualitative and quantitative analyses of functional groups were done by IR spectrometry. The results demonstrate that product size distribution of anthracite from Ningxia conformed to the n-order kinetic model and the grain size reached −42 nm after 24 h. The peak intensity of the IR spectra increased markedly, and the surface activity of anthracite powder was enhanced after ultrafine comminution. Penta-substituted benzene rings of aromatic hydrogen were the dominant group in raw anthracite, while tris-substituted benzene rings of aromatic hydrogen became the dominant form after 24 h of ultrafine comminution. During ultrafine comminution, cyclization of aliphatic chains, dehydroaromatization of cycloparaffin, substitution reactions of orienting groups on aromatic rings, and decarboxylic reactions of benzene rings might occur. Although raw anthracite shows a relatively high degree of metamorphism, its particles show stronger activity and can absorb more oxygen after ultrafine comminution, thus increasing oxygen enrichment. The CH in the aliphatic hydrocarbons of ultrafine anthracite basically disappeared, and CH2 was more easily lost than CH3 during ultrafine comminution. Oxygencontaining functional groups in anthracite were altered or some of their elements reacted with oxygen, which decreased the amount of free OH groups on anthracite particle surfaces. During ultrafine comminution, the stability of hydrogen bonds was ranked OH...π > OH...OH > free OH groups > OH...ether > OH...N > cyclic OH tetramers. These changes indicate that the ultrafine anthracite comminution process is also accompanied with chemical reactions. The results provide a reference and guidance for exploring changes in the molecular structures of ultrafine anthracite and follow-up deep processing. In particular, the occurrence of mercaptan -SH and FeS2 implies that sulfur exists in anthracite in both organic and inorganic forms. The absorption peak of ultrafine pulverized kaolinite was intensified, indicating that minerals were dissociated and more impurities were exposed after comminution. [ABSTRACT FROM AUTHOR]

The solvothermal reaction of 4,4′-bipyridine (Bipy) and mercury nitrate in a mixed acetonitrile/water solution leads to a novel mercury coordination compound with the in situ formation of cyanide ions Hg(Bipy)(CN)2 (1). Its structure is determined by single crystal X-ray diffraction (XRD), and further characterized by powder XRD, elemental analysis, and IR spectroscopy. Compound 1 exhibits a 1D zigzag [Hg(Bipy)(CN)2]n chain structure. The solid-state photoluminescent properties of 1 are also investigated. [ABSTRACT FROM AUTHOR]

Composite structures made of 2 mm-thick titanium and 10 mm-thick carbon steel are widely used in infrastructures such as long-distance gas transportation. However, cracking, which is caused by intermetallic compounds (ICs), is a dominate failure mode in welds of this structure. Thus, a common way to improve the in-service life of is reduce the number of ICs. In this paper, we employ a novel hybrid welding method to fabricate composite structures of TA2 titanium and Q235 carbon steel. Specifically, Ti and carbon steel is welded by laser and double Cold Metal Transfer (CMT) welding, respectively. The microstructure near the interface of Ti and steel is then examined using SEM, EBSD, EDS, with emphasis on the ICs in terms of chemical elements and morphologies. Results show that FeTi and Fe2Ti are the main ICs near the interface, and responsible for the failure of the welds. The effect of welding heat input on the formation of ICs is investigated as well. Results show that ICs are smaller when the heat input is low. Under low heat input circumstance, the tensile strength of the weld can reach up to 420 MPa. [ABSTRACT FROM AUTHOR]

A new monocular zinc(II) complex [Zn(L1)Cl2] (complex 1), where L1 stands for 2,6-bis{[(4-isopropylphenyl)imino]ethyl}pyridine is synthesized and characterized. Complex 1 crystallizes in the monoclinic crystal system in the P21/n space group with a = 10.941 Å, b = 15.918 Å, c = 16.199 Å, β = 107.60°, and Z = 4. L1 acts as a tridentate ligand and is coordinated to the Zn1 atom in a five-coordinated trigonal bipyramidal geometry. The thermogravimetric analysis suggests that complex 1 can be stable up to 351 °C. The study of the photoluminescent properties indicates that complex 1 shows intense metal-perturbed π–π* intraligand fluorescence in the solid state. [ABSTRACT FROM AUTHOR]

With the development of cold region engineering, it is crucial to study the mechanical properties of frozen soil. In practice, frozen soil is inevitably subject to impact loading, making the study of frozen soil under impact loading necessary for engineering in cold regions. The split–Hopkinson pressure bar (SHPB) is an important experimental means for obtaining the dynamic performance of materials. In this study, an SHPB experiment was conducted on frozen soil under confining pressure. The frozen soil exhibited an evident strain rate effect and temperature effect under confining pressure. The SHPB experiment on frozen soil under confining pressure was simulated numerically using LS-DYNA software and the Holmquist–Johnson–Cook (HJC) material model. A loading simulation with passive confining pressure and active confining pressure was completed by adding an aluminum sleeve and applying a constant load. The simulation results obtained using the above methods were in good agreement with the experimental results. The strength of the frozen soil under confining pressure was greater than that of the uniaxial impact, and there was an evident confining pressure effect. Furthermore, the confining pressure provided by passive confinement was larger than that provided by active confinement. The passive confining pressure energy absorption efficiency was higher than for the active confining pressure due to the need to absorb more energy under the same damage conditions. The frozen soil exhibited viscoplastic failure characteristics under confining pressure. [ABSTRACT FROM AUTHOR]

The nonlinear dynamic characteristics of giant magnetostrictive ultrasonic transducer (GMUT) are researched in this paper, and the optimal control strategy is proposed. New nonlinear differential terms are introduced to explain the hysteretic phenomena of giant magnetostrictive materials (GMM), and the nonlinear dynamic model of a giant magnetostrictive ultrasonic transducer subjected to harmonic magnetic field and stochastic disturbance is developed. The system's nonlinear dynamic responses are discussed, and the optimal control strategy is proposed to improve the system's accuracy. Numerical simulation and experiment results show that there are abundant nonlinear dynamic behaviors in the system; the stability of the system varies with the parameters, which causes stochastic bifurcation; the system's accuracy is improved through stochastic optimal control. The results of this study are helpful for the application of giant magnetostrictive ultrasonic transducer in engineering fields. [ABSTRACT FROM AUTHOR]

We design high-power AlGaInP laser diodes emitting at ~640 nm. AlN and SiC submounts are used as heat sinks for the laser chips. The laser diode with SiC submount showed a higher thermal rollover power of 3.9 W and higher maximum conversion efficiency of 39% at 25°C. In the range of 15 – 35°C, the two types of lasers have similar characteristic temperature T0. At higher temperatures beyond 40°C, the laser chip mounted on SiC revealed an improved T0, compared to that on AlN. By measuring the wavelength drift of the two types of lasers, we estimate the thermal resistance to be 9.1 K/W for the laser diode on AlN and 5.6 K/W for the laser diode on SiC. [ABSTRACT FROM AUTHOR]

The application of synchronous fluorescence spectroscopy combined with chemometrics using pretreated spectra was explored to develop a rapid, low-cost, and nondestructive method for discriminating between brands of different strong aroma type liquors. Principal component analysis, partial least square discriminant analysis, support vector machine, and back-propagation artificial neural network techniques were used to classify and predict the brands of liquor samples. Compared with the other models, the SVM model achieved the best results, with an identification rate of 100% for the calibration set, and 96.67% for the prediction set. The overall results showed that synchronous fluorescence spectroscopy with an efficient chemometrics method can be used successfully to identify different brands of liquor. [ABSTRACT FROM AUTHOR]

Abstract In the present study, selective laser melting (SLM) was used to successfully fabricate Inconel 718–tungsten carbide (WC) composites. The processing parameter optimization results reveal that nearly non-porous composites (99.54%) were achieved with the laser power of 220 W, scanning speed of 850 mm s−1, and the hatch spacing of 150 μm. The microstructural characterization unveils that elongated grain structure in the heat flow direction was observed in the case of pure IN718 while WC particles served as obstacles to hinder the grain growth in the composites. The formation of in situ intermediate layer and the strong interfacial bonding between WC super-hard particles and the matrix acted as load bearing and significantly contribute to the overall properties of composites. Mechanical tests indicate significant improvements of microhardness and tensile strengths, although a drop in strength was observed when the amount of WC reached 15 wt.%. In addition, the thermal experiment shows that the composites are dimensionally stable at higher temperature compared to their monolithic counterpart. The findings suggest that the developed IN718-WC composites can be utilized in many critical engineering applications in nuclear sector. [ABSTRACT FROM AUTHOR]

Insight into the anisotropic fracture properties of shale under a high in situ stress is important for the design and optimization of hydraulic fracturing treatment for deep shale formations. In this work, a series of hydraulic fracturing tests were conducted on hollow double wing crack specimens of Longmaxi shale with three principal fracture orientations: arrester, divider, and short transverse orientations. To reveal the influence of in situ stress on shale fractures, various confining pressures, i.e., 0, 20, 40, 60, and 80 MPa, were applied. The 3D anisotropic fracture properties of shale under deep in situ stress conditions were then investigated and highlighted. The breakdown pressure, mode I fracture toughness, and fracture energy were found to increase significantly with the confining pressure, indicating that the fracture resistance of the studied shale increases remarkably under high in situ stresses. Furthermore, as expected, both the fracture toughness and fracture energy exhibited remarkable anisotropies under each confining pressure condition, and the minimum fracture toughness and fracture energy were always found in the short transverse orientation. Interestingly, the fracture toughness and fracture energy in the arrester orientation were found to be smaller than those in the divider orientation under confining pressures ranging from 0 to 60 MPa, while the opposite was true under a confining pressure of 80 MPa, demonstrating that shale fracture anisotropy is influenced by in situ stress that should be carefully considered in hydraulic fracturing design. For fracture morphology, a higher confining pressure leads to a smoother fracture surface and more transgranular cracking. Highlights: Slight crack deflection is observed only in the arrester orientation The increase rates of fracture resistances gradually reduce as confining pressure increases High in situ stress changes the anisotropy in fracture resistance Unexpected, a higher confining pressure leads to a smoother fracture surface [ABSTRACT FROM AUTHOR]

The nonlinear dynamic characteristics of Fe-Ga cantilever nanobeam subjected to stochastic excitation are studied in this paper where the nonlocal effect is considered. Nonlinear differential terms are introduced to explain the hysteretic phenomena of the Fe-Ga alloy's strain-magnetic field intensity curves, and the nonlinear dynamic model of Fe-Ga cantilever composite nanobeam subjected to stochastic excitation is developed. The system's nonlinear dynamic characteristics are discussed, and the optimal control strategy is proposed to enhance the system's reliability. Numerical simulations show that the nonlocal effect can influence the system's stochastic Hopf bifurcation; the boundary of the system's safe basin has fractal characteristics, the area of safe basin decreases when the intensity of the noise increases, and it increases again through stochastic optimal control. The results of this study are helpful for the application of Fe-Ga composite nanobeam in engineering fields. [ABSTRACT FROM AUTHOR]

Yeast hybrid systems have been widely used due to their convenience and low cost. Based on these systems, many methods have been developed to analyze protein-protein, protein-DNA and protein-RNA interactions. In this paper, we are reviewing these different yeast hybrid systems. According to the number of hybrid proteins, yeast hybrid systems can be divided into three categories, yeast one-hybrid, yeast two-hybrid and yeast three-hybrid systems. Alternatively, yeast hybrid systems can be categorized according to the subcellular localization of the protein interaction process in the cell into nuclear protein-protein interactions, cytosol protein-protein interactions and membrane protein-protein interactions. Throughout the review, we focus on the progress and limitations of each yeast hybrid system over the recent years. [ABSTRACT FROM AUTHOR]

Dynamic modeling of tethered spacecraft with the consideration of elasticity of tether is prone to the numerical instability and error accumulation over long-term numerical integration. This paper addresses the challenges by proposing a globally stable numerical approach with the nodal position finite element method (NPFEM) and the implicit, symplectic, 2-stage and 4th order Gaussian-Legendre Runge-Kutta time integration. The NPFEM eliminates the numerical error accumulation by using the position instead of displacement of tether as the state variable, while the symplectic integration enforces the energy and momentum conservation of the discretized finite element model to ensure the global stability of numerical solution. The effectiveness and robustness of the proposed approach is assessed by an elastic pendulum problem, whose dynamic response resembles that of tethered spacecraft, in comparison with the commonly used time integrators such as the classical 4th order Runge-Kutta schemes and other families of non-symplectic Runge-Kutta schemes. Numerical results show that the proposed approach is accurate and the energy of the corresponding numerical model is conservative over the long-term numerical integration. Finally, the proposed approach is applied to the dynamic modeling of deorbiting process of tethered spacecraft over a long period. [ABSTRACT FROM AUTHOR]

Background:Aberrant Smad7 expression contributes to the invasion and metastasis of pancreatic cancer cells. However, the potential mechanism underlying aberrant Smad7 expression in human pancreatic ductal adenocarcinoma (PDAC) remains largely unknown.Methods:Bioinformatic prediction programmes and luciferase reporter assay were used to identify microRNAs regulating Smad7. The association between miR-367 expression and the overall survival of PDAC patients was evaluated by Kaplan-Meier analysis. The effects of miR-367 and Smad7 on the invasion and metastasis of pancreatic cancer cells were investigated both in vitro and in vivo.Results:We found that miR-367 downregulated Smad7 expression by directly targeting its 3′-UTR in human pancreatic cancer cells. High level of miR-367 expression correlated with poor prognosis of PDAC patients. Functional studies showed that miR-367 promoted pancreatic cancer invasion in vitro and metastasis in vivo through downregulating Smad7. In addition, we showed that miR-367 promoted epithelial-to-mesenchymal transition by increasing transforming growth factor-β (TGF-β)-induced transcriptional activity.Conclusions:The present study identified and characterised a signalling pathway, the miR-367/Smad7-TGF-β pathway, which is involved in the invasion and metastasis of pancreatic cancer cells. Our results suggest that miR-367 may be a promising therapeutic target for the treatment of human pancreatic cancer. [ABSTRACT FROM AUTHOR]

Nonlinear dynamic characteristics and optimal control of magnetic shape memory alloy (MSMA) cantilever beam subjected to axial stochastic excitation is studied in this paper. Nonlinear difference item is introduced to interpret the hysteretic phenomena of MSMA, and the nonlinear dynamic model of MSMA cantilever beam subjected to axial stochastic excitation is developed. The steady-state probability density function of the dynamic response of the system is obtained, and the conditions of stochastic Hopf bifurcation are analyzed. The reliability function of the system is solved, and then the probability density of the first-passage time is obtained. Finally, the optimal control strategy is proposed in stochastic dynamic programming method. Numerical simulations show that the stability of the trivial solution varies with bifurcation parameter, and stochastic Hopf bifurcation appears in the process; the reliability of the system is proved by stochastic optimal control, and the first-passage time is delayed. The results are helpful to engineering application of MSMA cantilever beam. [ABSTRACT FROM AUTHOR]

Let R be a ring, and let n; d be non-negative integers. A right R-module M is called (n; d)-projective if Extd+1 R (M;A) = 0 for every n-copresented right R-module A. R is called right n- cocoherent if every n-copresented right R-module is (n+1)-coprese- nted, it is called a right co-(n; d)-ring if every right R-module is (n; d)-projective. R is called right n-cosemihereditary if every sub- module of a projective right R-module is (n; 0)-projective, it is called a right n-V-ring if it is a right co-(n; 0)-ring. Some properties of (n; d)-projective modules and (n; d)-projective dimensions of modules over n-cocoherent rings are studied. Certain characterizations of n-copresented modules, (n; 0)-projective modules, right n-cocoherent rings, right n-cosemihereditary rings, as well as right n-V-rings are given respectively. [ABSTRACT FROM AUTHOR]

Background:Many radiation regimens for treating prostate cancer have been used over the years, but which regimen is optimal for localised or locally advanced prostate cancer lacks consensus. We performed a network meta-analysis to identify the optimal radiation regimen.Methods:We systematically reviewed data from 27 randomised controlled trials and could group seven radiation regimens as follows: low- and high-dose radiation therapy (LDRT and HDRT), LDRT+ short- or long-term androgen deprivation therapy (LDRT+SADT and LDRT+LADT), HDRT+SADT, hypofractionated radiotherapy (HFRT), and HFRT+SADT. The main outcomes were overall mortality (OM), prostate-specific antigen (PSA) failure, cancer-specific mortality, and adverse events.Results:For the network meta-analysis of 27 trials, LDRT+LADT and LDRT+SADT were associated with decreased risk of OM as compared with LDRT alone as was LDRT+LADT compared with HDRT. Apart from HFRT, all other treatments were associated with decreased risk of PSA failure as compared with LDRT. HFRT+SADT was associated with decreased risk of cancer-specific mortality as compared with HFRT, LDRT+SADT, HDRT, and LDRT.Conclusions:HFRT+SADT therapy might be the most efficacious treatment but with worst toxicity for localised or locally advanced prostate cancer, and HDRT showed excellent efficacy but more adverse events. [ABSTRACT FROM AUTHOR]

We theoretically demonstrate that an electrically tunable polarizer can be obtained using a periodic array of graphene ribbons supported on a dielectric film on top of a thick piece of metal. The polarizing mechanism originates from anisotropic absorption of the graphene ribbons. The results of fullwave numerical simulations reveal that absorption of 0.0075 for one polarization and 0.9986 for another polarization can be obtained at normal incidence in the THz range. For circular incidence polarization, the corresponding polarizing extinction ratio increases to 65 dB. [ABSTRACT FROM AUTHOR]

In addition to protein-coding genes, the human genome makes a large amount of noncoding RNAs, including microRNAs and long noncoding RNAs (lncRNAs). Both microRNAs and lncRNAs have been shown to have a critical role in the regulation of cellular processes such as cell growth and apoptosis, as well as cancer progression and metastasis. Although it is well known that microRNAs can target a large number of protein-coding genes, little is known whether microRNAs can also target lncRNAs. In the present study, we determine whether miR-21 can regulate lncRNA expression. Using the lncRNA RT-PCR (reverse transcription-polymerase chain reaction) array carrying 83 human disease-related lncRNAs, we show that miR-21 is capable of suppressing the lncRNA growth arrest-specific 5 (GAS5). This negative correlation between miR-21 and GAS5 is also seen in breast tumor specimens. Of interest, GAS5 can also repress miR-21 expression. Whereas ectopic expression of GAS5 suppresses, GAS5-siRNA increases miR-21 expression. Importantly, there is a putative miR-21-binding site in exon 4 of GAS5; deletion of the miR-21-binding site abolishes this activity. Experiments with in vitro cell culture and xenograft mouse model suggest that GAS5 functions as a tumor suppressor. We further show that the biotin-labeled GAS5-RNA probe is able to pull down the key component (AGO2) of the RNA-induced silencing complex (RISC) and we subsequently identify miR-21 in this GAS5-RISC complex, implying that miR-21 and GAS5 may regulate each other in a way similar to the microRNA-mediated silencing of target mRNAs. Together, these results suggest that miR-21 targets not only tumor-suppressive protein-coding genes but also lncRNA GAS5. [ABSTRACT FROM AUTHOR]

This paper studies libration dynamics and stability of deorbiting nano-satellites by short and bare electrodynamic tethers. A critical aspect of satellite deorbit by an electrodynamic tether is to maintain the tether aligned with the local vertical and stable while subjected to external perturbations. The dynamics of electrodynamic tether system in deorbit application is divided into the orbital motion of the center of system's mass and the tether libration motion relative to that center. Major space environmental perturbations including the current-induced electrodynamic force, atmospheric drag, oblateness effect of the Earth, irregularity of geomagnetic field, variable plasma density, solar radiation pressure, and lunisolar gravitational attractions are considered in the dynamic analysis. Quantitative analyses are provided in order to characterize the order of the perturbative torques during the deorbit process. A single index is derived from the libration energy to stabilize the libration motion by regulating the current in the tether through simple on-off switching. Numerical results show that the libration dynamics of an electrodynamic tether has significant impacts on the deorbit process and the electrodynamic tether cannot effectively deorbit satellites without libration stability control. The proposed current regulation strategy is simple and very effective in stabilizing libration motion of an electrodynamic tether. [ABSTRACT FROM AUTHOR]

In this paper, nonlinear dynamic characteristics and optimal control of giant magnetostrictive laminated plate (GMLP) subjected to in-plane stochastic excitation were studied. Von del Pol nonlinear item was introduced to interpret the hysteresis phenomenon of the strain-magnetic field intensity curve of giant magnetostrictive material, and the nonlinear dynamic model of GMLP subjected to in-plane stochastic excitation was developed. Local and global stochastic stabilities were analyzed according to largest Lyapunov exponent theory and singular boundary theory. The functions of steady-state probability density and joint probability density were obtained, and the condition of stochastic Hopf bifurcation was analyzed. The reliability function was solved from backward Kolmogorov equation, and the probability density of the first-passage time was obtained. Finally, the optimal control strategy was proposed in stochastic dynamic programming method. Numerical simulation shows that the stability of the solution varies with parameter, and stochastic Hopf bifurcation appears in the process; the reliability of the system was improved by optimal control, and the first-passage time was delayed. The result is helpful to engineering applications of GMLP. [ABSTRACT FROM AUTHOR]

We theoretically show that a polarization-independent optical band-stop filter operation can be performed by a two-dimensional sub-wavelength array of symmetric cross-shaped plasmonic nanoantennas. The proposed filter's optical properties can be controlled by varying the size and periodicity of the plasmonic nanoantennas. So, this can be used to design filters in many frequency ranges of interest. In addition, the filter is simply constructed as a coating with only 30-nm thickness, which is much thinner than the operation wavelength, and thus facilitates the fabrication and further large-scale optical integration. [ABSTRACT FROM AUTHOR]

This paper analyses reflection and refraction of plane waves at a perfect interface between two anisotropic piezoelectric media. The equations of elastic waves, quasi-static electric field, and constitutive relationships for the piezoelectric media are derived. A solution based on the inhomogeneous wave theory is developed to address the inconsistency between the numbers of independent wave modes in the media and the numbers of interfacial boundary conditions to obtain accurate reflection and refraction coefficients in case of strong piezoelectric media, where all the elastic and electric continuity conditions across the interface are satisfied simultaneously. The study shows that there exist independent and zero energy wave modes satisfying the general Snell's law and propagating along the interface for any incident wave angle. These waves can be treated as pseudo surface waves. It is further found that all the reflection/refraction waves including the pseudo surface waves obey the energy conservation law at the interface boundary. In addition, the analysis also reveals that the reflection and refraction elastic waves can turn into pseudo surface waves at some critical incident angles. [ABSTRACT FROM AUTHOR]

This paper investigates the potential of ultrasonic non-destructive measurements of residual stresses using the modal frequency spacing method based on the interference spectrum of leaky Lamb waves as an alternative to the commonly used flight-time approach in ultrasonic methods. Extensive experiments were carried out to verify the viability and robustness of the technique using an instrumented leaky Lamb wave setup with uniaxial stressed samples and welded steel samples. To improve the signal-to-noise ratio, multiple sets of raw signals of specularly reflected and leaky Lamb waves were acquired and then averaged in the time domain. The acquired data in the time domain were then transformed into the frequency domain to form the interference spectrum of leaky Lamb waves with a good repeatability. The acoustoelastic coefficient of carbon steel is then derived from the measured relationship of wave velocity and applied stress. Finally, a welded steel plate was examined and residual stress was evaluated. The current work demonstrates the feasibility and the potential of the proposed method in measuring residual stresses in welded plates and thin-walled structures. [ABSTRACT FROM AUTHOR]

Introduction: Description of syrinx resolution after posterior fossa decompression (PFD) in patients with scoliosis secondary to Chiari malformation type I (CMI) and syringomyelia (SM) has been rarely reported in the literature. This study was performed to investigate the outcome of PFD in patients with scoliosis secondary to CMI and to identify potential predictive factors for better outcome after PFD.Material and Methods: Patients with scoliosis secondary to CMI and SM, who had undergone PFD during the period 2000 through 2009, were recruited. Inclusion criteria were (1) age ≤ 18 years, (2) diagnosis of SM associated with CMI, (3) scoliosis as the first complaint, (4) having undergone preoperative and follow-up magnetic resonance imaging (MRI). Patients with acquired CMI anomalies or who had received syringosubarachnoid shunting were excluded. The maximal S/C ratio and syrinx length were measured to evaluate syrinx resolution after PFD. A 20% decrease in S/C ratio or length at the latest follow-up was defined as a significant radiographic improvement and complete resolution was used to describe the syrinx disappearing after PFD.Results: 44 patients were recruited. Follow-up MRI was conducted for all 44 patients at 6 ± 3 months postoperatively, for 37 patients at 2 years ± 3 months, for 26 patients at 4 years ± 3 months, and for 15 patients at 6 years ± 3 months. 97.7% (43 of 44) of patients showed significant radiographic improvement by MRI. The distance of tonsillar descent (mm) was correlated significantly with the surgical outcome (r = 0.116, P = 0.013). Significant improvement was observed within 6 months postoperatively, with continued slow improvement after that.Conclusion: Syringes showed significant improvement after PFD in most patients with scoliosis secondary to CMI. Resolution generally occurred within 6 months follow-up and continued at a slow rate for several years. In addition, the severity of tonsillar descent is a potential predictor for better improvement after standard PFD. [ABSTRACT FROM AUTHOR]

This study aims to investigate the influence of diet roughage proportion on the methanogenic communities from the rumen and fecal samples in Altay local sheep native to Xinjiang and better understand the association of methanogenic diversity or abundance with methane emissions of the ruminants. In this study, the high roughage diet was found to cause more methane emissions for either maintenance or ad- lib group, but the total methanogenic abundance was not influenced by roughage proportion and showed no significant difference between groups. Furthermore, the denaturing gradient gel electrophoresis was conducted to reveal the difference in methanogenic diversity. Phylogenetic analysis showed that the sequences obtained were divided into three groups, affiliated to the genus of Methanobrevibacter, Methanocorpusculum and an unidentified methanogenic-like group. Of these sequences, the predominant diversity from the genus of Methanobrevibacter and the unidentified methanogenic-like archaeons in the rumen was found to be significantly induced by the high roughage diet, implying that the variation of diversity at the species or strain level might have an effect on methane emissions from the rumen. Further analysis showed that five methangenic sequences from the rumen were possibly associated with the differential methane emissions. [ABSTRACT FROM AUTHOR]

This paper presents a nondestructive stress evaluation technique using the ultrasonic interference spectrum of leaky Lamb waves. By using a specific pitch-catch ultrasonic setup, the symmetric and antisymmetric modes of Lamb waves in a finite plate are decoupled, leading to simple relationships between the modal frequency spacing of two adjacent modes in the interference spectrum and the acoustic wave velocities that are functions of stress. As a result, the stress in the plate can be determined by measuring the modal frequency spacing instead of the relative flight times to calculate the acoustic wave velocity. Extensive experiments were carried out to verify the viability and robustness of the new technique using a simple testing system. It has been demonstrated that the new technique is about 25 times more accurate than existing flight-time approaches using the same testing system. The experimental results agree well with the results obtained by other ultrasonic methods using expensive equipment. [ABSTRACT FROM AUTHOR]

To elucidate the osmotic adjustment characteristics of mangrove plants, inorganic ion and organic solute contents of intermediate leaves were investigated in 3-month-old Kandelia candel (L.) Druce seedlings during 45 days of NaCl treatments (0, 200, and 500 mM NaCl). The contents of Na, Cl, total free amino acids, proline, total soluble sugars, pinitol and mannitol increased to different degree by salinity, whereas, K content decreased by salinity compared with control. NaCl treatment induced an increase of inorganic ion contribution while a decrease of organic solute contribution. It was concluded that accumulating a large amount of inorganic ions was used as the main osmotic adjustment mechanism under salinity treatment. However, accumulation of organic osmolytes might be considered to play much more important role in osmoregulation under severe salinity (500 mM NaCl) than under moderate salinity (200 mM NaCl), thus the damage caused by high toxic ions (Na and Cl) concentration in K. candel leaves could be avoided. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) techniques including laser powder bed fusion have been widely used to produce metallic components with microstructures and mechanical properties distinctly different from the conventionally manufactured counterparts. Understanding how AM parameters affect the evolution of microstructure, including texture, of these AM metallic components is critical for appropriate manipulation of their processing and therefore their mechanical properties. Here we conducted a systematic investigation of texture evolution of a face-centred cubic CrMnFeCoNi high-entropy alloy cuboid fabricated using laser powder bed fusion. Our results showed that the texture evolutions along the build direction were different between the corner and central parts of the sample. Detailed analysis suggested that the texture evolution is closely related to local thermal gradient, which is a property that can be manipulated through changing AM parameters. The different textures lead to the significant variations of mechanical properties within the sample. [ABSTRACT FROM AUTHOR]

A prototype of a Superconducting Electromagnet Iron Remover (SEIR) system with a 3 tesla (T) central field has been designed and manufactured at the Institute of High Energy Physics (IHEP) of China. The SEIR system is deliberately designed to separate small pieces of hazardous ferromagnetic materials, such as detonators, from coal to achieve high purity and good yield. The SEIR system consists of a NbTi superconducting magnet, a LHe recondensation type cryostat with two GM cryocoolers (31 W/40 K, 1 W/4.2 K), and a pair of binary current leads (CLs), etc. This paper presents the thermal analysis and experimental results of the SEIR system. A three-dimensional (3D) model of calculation for the magnet system was built. The heat load and the temperature distribution of the magnet system were analyzed using a finite element method. With regard to the heat load of the system, the finite element analysis (FEA) simulation results were quite close to the experimental results. [ABSTRACT FROM AUTHOR]

CSR1 (cellular stress response 1), a newly characterized tumor-suppressor gene, undergoes hypermethylation in over 30% of prostate cancers. Re-expression of CSR1 inhibits cell growth and induces cell death, but the mechanism by which CSR1 suppresses tumor growth is not clear. In this study, we screened a prostate cDNA library using a yeast two-hybrid system and found that the cleavage and polyadenylation-specific factor 3 (CPSF3), an essential component for converting heteronuclear RNA to mRNA, binds with high affinity to the CSR1 C terminus. Further analyses determined that the binding motifs for CPSF3 are located between amino acids 440 and 543. The interaction between CSR1 and CPSF3 induced CPSF3 translocation from the nucleus to the cytoplasm, resulting in inhibition of polyadenylation both in vitro and in vivo. Downregulation of CPSF3 using small interfering RNA induced cell death in a manner similar to CSR1 expression. A CSR1 mutant unable to bind to CPSF3 did not alter CPSF3 subcellular distribution, did not inhibit its polyadenylation activity and did not induce cell death. In summary, CSR1 appears to induce cell death through a novel mechanism by hijacking a critical RNA processing enzyme.Oncogene (2009) 28, 41–51; doi:10.1038/onc.2008.359; published online 22 September 2008 [ABSTRACT FROM AUTHOR]

We evaluate reference data to examine whether there are sex-, age-, height-, weight- and BMI-related differences of quantitative ultrasound parameters (QUS) for healthy Chinese children and adolescents. A total of 726 healthy children and adolescents (360 male and 366 female) aged from 10–21 years were examined with a Lunar Achilles Express densitometer. The measurements on the right heel included speed of sound (SOS), broadband ultrasound attenuation (BUA), and a calculated stiffness index (SI). Our results found that there were no significant differences for BUA, SOS and SI between males and females, except in the age range of 12 to 13 years. The values of all parameters were significantly higher in the 12-year-old females compared to males, and BUA values were significantly higher in 13-year-old females compared to males. A spurt in QUS parameters were observed at 12 years in females and at 14 years in males. A steady increase of BUA, SOS, and SI was seen with increasing body height and weight in both sexes. In conclusion, the present results can be used as reference data for children and adolescents in China. [ABSTRACT FROM AUTHOR]

Quantitative structure-pharmacokinetic/pharmacodynamic (PK/PD) relationship (QSPR) techniques and chemometric methods were employed to classify fluoroquinolones with respect to their activity against Streptococcus pneumoniae. Density functional theory (DFT) was used to calculate a set of molecular descriptors (properties) for 13 synthetic fluoroquinolones. The descriptors were further analyzed using chemometric methods including principal component analysis (PCA), hierarchical cluster analysis (HCA), and stepwise discriminant analysis (SDA). The PCA and SDA methods were employed in order to reduce the dimensionality and select a subset of variables that would be more effective for classifying the fluoroquinolones according to their degree of antipneumococcal activity. The methods of PCA, SDA and HCA were quite efficient to classify 13 compounds in two groups (active and inactive), and the net charge on ring B ( Q B), molecular volume (VOL), and partition coefficient (log P ) were found to be descriptors important for the classification. These methodologies of PCA, SDA and HCA provide a reliable rule for classifying new fluoroquinolones with respect to antipneumococcal activity. The application of the SPP relationship is of considerable value for clinicians, drug developers, and regulators because PK/PD principles form the basis of modern antimicrobial chemotherapy. [ABSTRACT FROM AUTHOR]

We propose a novel photonic crystal waveguide configuration consisting of coupled-resonator optical waveguides at the termination to obtain enhanced transmission and beaming of light. We show theoretically that such a configuration can collimate the light output from a photonic crystal waveguide over a wide bandwidth range. The mechanism explained in this paper may be easily extrapolated to the photonic crystal configuration of air holes in a dielectric substrate. [ABSTRACT FROM AUTHOR]

Yb3+:GdAl3(BO3)4 (hereafter Yb3+:GAB) crystals with large sizes and good optical quality have been grown by the top-seed solution growth (TSSG) method. The polarized absorption and emission spectra have been investigated at room temperature. For the σ-polarization, the intensities of both absorption and emission spectra are stronger than those for the π-polarization, the σ-absorption cross section of Yb3+ in GAB being 3.43×10-20 cm2 at 977 nm, and the σ-emission cross section being 0.98×10-20 cm2 at 1045 nm. The fluorescence lifetime of the 2 F 5/2→2 F 7/2 transition was measured to be 800 μs in the 5% doped sample used for our laser experiments, 993 μs in a 10% doped sample and 569 μs in a 0.5% doped sample. The laser parameters were estimated as: βmin=0.022, Isat=10.4 kW/cm2 and Imin=0.23 kW/cm2. About 0.4 W laseroutput at the wavelength of 1043 nm was achieved when the Yb3+:GAB crystal was pumped by a 974 nm laser diode, with 27.4% slope efficiency. [ABSTRACT FROM AUTHOR]

The application of recognition for the weld seam and its initial position in a complicated environment based on the image pattern match technology has been discussed. According to adopting the two-step pattern match method, the recognition speed and accuracy have been improved, and the error points have been wiped off during the global pattern match stage by using the area analysis method. The initial position can be accurately recognized by using the method that dynamically adjusts the search area during the local pattern match stage in the area that is near the end of the weld. The results of the experiments prove that this method not only has the characters that include anti-jamming, fast running speed and high recognition, but also has a preferably practical value. [ABSTRACT FROM AUTHOR]

A series of mesoporous Al2O3 samples with different porous structures and phases were prepared and used as supports for Cu/Al2O3 catalysts. These catalysts were characterized by N2 adsorption, NMR, TGA, XRD, and UV–vis spectroscopic techniques and tested for the catalytic reaction of N2O decomposition. The activity increased with the increasing calcination temperatures of supports from 450 to 900 °C; however, a further increase in calcination temperature up to 1200 °C resulted in a significant reduction in activity. Characterization revealed that the calcination temperatures of supports influenced the porous structures and phases of the supports, which in turn affected the dispersions, phases, and activities of the impregnated copper catalyst. The different roles of surface spinel, bulk CuAl2O4, and bulk CuO is clarified for N2O catalytic decomposition. Two mechanism schemes were thus proposed to account for the varying activities of different catalysts. [ABSTRACT FROM AUTHOR]

Large-scale and very even multi-wall carbon nanotube (MWNT) films have been obtained at room temperature by an electrophoresis deposition technique. The characterization, by means of scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, and micro-Raman spectroscopy, shows that the MWNTs with hydrogen-plasma (HP) treatment are covered by onion-like nanolumps, and three-dimensional multiple-way- connected nanotube webs are formed. The electronic property of the treated MWNT film is converted from semiconducting to metallic. The field-emission test indicates that the HP-treated MWNT film has a low threshold of 1.1 V/μm (at 0.1 μA/cm[SUP2]), a high emission light spot density of about 105 cm[SUP-2], and a stable and suitable emission current. The conversion mechanism of the treated carbon nanotube structure and the reason for the change of the electronic and field-emission characteristics of the MWNT films are discussed. [ABSTRACT FROM AUTHOR]

Root growth is critical for crops to use soil water under water-limited conditions. A field study was conducted to investigate the effect of available soil water on root and shoot growth, and root water uptake in winter wheat (Triticum aestivum L.) under deficit irrigation in a semi-arid environment. Treatments consisted of rainfed, deficit irrigation at different developmental stages, and adequate irrigation. The rainfed plots had the lowest shoot dry weight because available soil water decreased rapidly from booting to late grain filling. For the deficit-irrigation treatments, crops that received irrigation at jointing and booting had higher shoot dry weight than those that received irrigation at anthesis and middle grain filling. Rapid root growth occurred in both rainfed and irrigated crops from floral initiation to anthesis, and maximum rooting depth occurred by booting. Root length density and dry weight decreased after anthesis. From floral initiation to booting, root length density and growth rate were higher in rainfed than in irrigated crops. However, root length density and growth rate were lower in rainfed than in irrigated crops from booting to anthesis. As a result, the difference in root length density between rainfed and irrigated treatments was small during grain filling. The root growth and water use below 1.4 m were limited by a caliche (45% CaCO3) layer at about 1.4 m profile. The mean water uptake rate decreased as available soil water decreased. During grain filling, root water uptake was higher from the irrigated crops than from the rainfed. Irrigation from jointing to anthesis increased seasonal evapotranspiration, grain yield, harvest index and water-use efficiency based on yield (WUE), but did not affect water-use efficiency based on aboveground biomass. There was no significant difference in WUE among irrigation treatments except one-irrigation at middle grain filling. Due to a relatively deep root system in rainfed crops, the higher grain yield and WUE in irrigated crops compared to rainfed crops was not a result of rooting depth or root length density, but increased harvest index, and higher water uptake rate during grain filling. [ABSTRACT FROM AUTHOR]

A theoretical investigation for the conductivity of single walled nanotube films is carried out with an effective medium model in the Terahertz region. The results are compared with the recent experiment and a decrease of the real conductivity with increasing frequency is predicted. Meanwhile, the off-diagonal components of the dielectric function of single-walled carbon nanotube films based on the magnetooptical effects are also shown. © 2003 MAIK “Nauka / Interperiodica”. [ABSTRACT FROM AUTHOR]

Vascular endothelial growth factor (VEGF) and its receptors (VEGFR) have been implicated in promoting solid tumor growth and metastasis via stimulating tumor-associated angiogenesis. We recently showed that certain 'liquid' tumors such as leukemia not only produce VEGF, but also express functional VEGFR, resulting in an autocrine loop for tumor growth and propagation. A chimeric anti-VEGFR2 (or kinase insert domain containing receptor, KDR) antibody, IMC-1Cll, was shown to be able to inhibit VEGF-induced proliferation of human leukemia cells in vitro, and to prolong survival of nonobese diabetic-severe combined immune deficient (NOD-SCID) mice inoculated with human leukemia cells. Here we produced two fully human anti-KDR antibodies (IgG1), IMC-2C6 and IMC-1121, from Fab fragments originally isolated from a large antibody phage display library. These antibodies bind specifically to KDR with high affinities: 50 and 200pM for IMC-1121 and IMC2C6, respectively, as compared to 270pM for IMC-1Cll. Like IMC-1Cll, both human antibodies block VEGF/KDR interaction with an ICs0 of approximately 1 nM, but IMC-1121 is a more potent inhibitor to VEGF-stimulated proliferation of human endothelial cells. These anti-KDR antibodies strongly inhibited VEGF-induced migration of human leukemia cells in vitro, and when administered in vivo, significantly prolonged survival of NOD-SCID mice inoculated with human leukemia cells. It is noteworthy that the mice treated with antibody of the highest affinity, IMC-1121, survived the longest period of time, followed by mice treated with IMC-2C6 and IMC-1Cll. Taken together, our data suggest that anti-KDR antibodies may have broad applications in the treatment of both solid tumors and leukemia. It further underscores the efforts to identify antibodies of high affinity for enhanced antiangiogenic and antitumor activities. [ABSTRACT FROM AUTHOR]

Investigates the link between tryptophan hydroxylase (TPH) and suicide completion. Association between the gene that codes TPH and suicidal behavior; Genotyping of a sample of suicide completers; Public-health problem of suicidal behavior; Evidence that subjects with suicidal behavior have reduced serotonergic neuro-transmission.

Key message: WSL8 encoding a deoxyribonucleoside kinase (dNK) that catalyzes the first step in the salvage pathway of nucleotide synthesis plays an important role in early chloroplast development in rice. The chloroplast is an organelle that converts light energy into chemical energy; therefore, the normal differentiation and development of chloroplast are pivotal for plant survival. Deoxyribonucleoside kinases (dNKs) play an important role in the salvage pathway of nucleotides. However, the relationship between dNKs and chloroplast development remains elusive. Here, we identified a white stripe leaf 8 (wsl8) mutant that exhibited a white stripe leaf phenotype at seedling stage (before the four-leaf stage). The mutant showed a significantly lower chlorophyll content and defective chloroplast morphology, whereas higher reactive oxygen species than the wild type. As the leaf developed, the chlorotic mutant plants gradually turned green, accompanied by the restoration in chlorophyll accumulation and chloroplast ultrastructure. Map-based cloning revealed that WSL8 encodes a dNK on chromosome 5. Compared with the wild type, a C-to-G single base substitution occurred in the wsl8 mutant, which caused a missense mutation (Leu 349 Val) and significantly reduced dNK enzyme activity. A subcellular localization experiment showed the WSL8 protein was targeted in the chloroplast and its transcripts were expressed in various tissues, with more abundance in young leaves and nodes. Ribosome and RNA-sequencing analysis indicated that some components and genes related to ribosome biosynthesis were down-regulated in the mutant. An exogenous feeding experiment suggested that the WSL8 performed the enzymic activity of thymidine kinase, especially functioning in the salvage synthesis of thymidine monophosphate. Our results highlight that the salvage pathway mediated by the dNK is essential for early chloroplast development in rice. [ABSTRACT FROM AUTHOR]

The structural, electronic and magnetic properties of organic-inorganic hybrid mixed perovskites CH3NH3CrxPb1−xI3 (x = 0.25, 0.50, 0.75, 1.00) in cubic, tetragonal and orthorhombic phases have been investigated by first-principles calculation. The results indicate that the tetragonal CH3NH3Cr0.75Pb0.25I3 is a spin gapless semiconductor with Curie temperature of 663 K estimated using mean field approximation. All other CH3NH3CrxPb1−xI3 mixed perovskites are half-metallic ferromagnets together with 100% spin polarization, and their total magnetic moment are 4.00, 8.00, 12.00 and 16.00 µB per unit cell for x = 0.25, 0.50, 0.75 and 1.00, respectively. The effect of <100>, <110> and <111> orientation of organic cation CH3NH3+ on the electronic properties of CH3NH3Cr0.50Pb0.50I3 was investigated. The results show that the CH3NH3+ in different orientations have a slight effect on the lattice constants, the energy gap in minority-spin states, half-metallic gap, local magnetic moment, and Curie temperature. [ABSTRACT FROM AUTHOR]

Coherent light-matter interaction in ultrathin metamaterials has been demonstrated to dynamically modulate intensity, polarization and propagation direction of light. The gradient metasurface with a transverse phase variation usually exhibits an anomalous refracted beam of light dictated by so-called generalized Snell's law. However, less attention has been paid to coherent control of the metasurface with multiple anomalous refracted beams. Here we propose an ultrathin gradient metasurface with single trapezoid-shaped slot antenna as its building block that allows one normal and two deflected transmitted beams. It is numerically demonstrated that such metasurface with multiple scattering modes can be coherently controlled to modulate output intensities by changing the relative phase difference between two counterpropagating coherent beams. Each mode can be coherently switched on/off and two deflected anomalous beams can be synchronously dictated by the phase difference. The coherent control effect in the trapezoid-shaped slit metasurface will offer a promising opportunity for multichannel signals modulation, multichannel sensing and wave front shaping. [ABSTRACT FROM AUTHOR]