Search

The tungsten inert gas (TIG) welding–brazing technology using Mg based filler was developed to join AZ31B Mg alloy to TA2 pure Ti in a lap configuration. The results indicate that robust joints can be obtained with welding current in the range of 60–70 A and welding speed of 0·2 m min−1. The joints were found to be composed of the coarse grained fusion zone accompanied with the precipitated phase of Mg17Al12, and a distributed Mg–Ti solid solution zone at the interface of Mg/Ti, indicating that metallurgical bonding was achieved. The maximum tensile–shear strength of 193·5 N mm−1, representing 82·3% joint efficiency relative to the Mg alloy base metal, was attained. The optimised Mg/Ti joint fractured at Mg fusion zone upon tensile–shear loading, mainly caused by grain coarsening. Moreover, the fracture surface practically consisted of scraggly areas, which was characterised by equiaxed dimple patterns accompanied with a few lamellar tearing.

Summary In the secretory pathway, budding of vesicular transport carriers from the trans-Golgi network (TGN) must coordinate specification of lipid composition with selection of secreted proteins. We elucidate a mechanism of soluble protein cargo sorting into secretory vesicles with a sphingomyelin-rich membrane; the integral membrane proteoglycan Syndecan-1 (SDC1) acts as a sorting receptor, capturing the soluble enzyme lipoprotein lipase (LPL) during export from the TGN. Sorting of LPL requires bivalent interactions between LPL and SDC1-linked heparan sulfate chains and between LPL and the Golgi membrane. Physical features of the SDC1 transmembrane domain, rather than a specific sequence, confer targeting of SDC1 and bound LPL into the sphingomyelin secretion pathway. This study establishes that physicochemical properties of a protein transmembrane domain that drive lateral heterogeneity of the plasma membrane also operate at the TGN to confer sorting of an integral membrane protein and its ligand within the biosynthetic secretory pathway.

In this paper, the shielding effectiveness of the electromagnetic shielding composite coating with copper powder and silver coated copper powder as the base material was tested by preparing the polyurethane matrix with 0.95~1.01 isocyanate index and adding flaky ferro-silico-aluminium powder. The field comparison experiment shows that the silver-clad copper-based electromagnetic shielding composite coating has a good efficiency of power frequency electromagnetic shielding, which is up to 30.71dB. It has a broad application prospect in the field of electromagnetic protection of power transmission and transformation facilities.

Impulse pressuring diffusion bonding of a copper alloy to a stainless steel was performed in vacuum. Using Ni interlayer of 12.5 μm, the joint produced at 825 °C under 5–20 MPa for 20 min exhibited lower strength, which could result from the insufficient thermal excitation and plastic deformation. At 850 °C under 5–20 MPa for 5–20 min, the strength of the joint improved with time. An optimized joint strength reached up to 217.2 MPa. Fracture occurred along the Cu–Ni reaction layer and the Ni layer and almost plastic fracture was confirmed by extensive dimples on the fracture surface. Using the interlayer of 50 μm, the fracture surface was similar. Without Ni assistance, under the same bonding condition, the joint strength was about 174.2 MPa. The lowered strength might be attributed to the appearance of some unbonded zones in the joint. Lots of brittle fracture areas appeared on the fracture surface.

STIM1 (stromal interaction molecule 1) is one of the key elements that mediate store-operated Ca2+ entry via CRAC (Ca2+- release-activated Ca2+) channels in immune and non-excitable cells. Under physiological conditions, the intramolecular auto-inhibitions in STIM1 C- and STIM1 N-termini play essential roles in keeping STIM1 in an inactive state. However, the auto-inhibitory mechanism of the STIM1 C-terminus is still unclear. In the present study, we first predicted a short inhibitory domain (residues 310–317) in human STIM1 that might determine the different localizations of human STIM1 from Caenorhabditis elegans STIM1 in resting cells. Next, we confirmed the prediction and further identified an aromatic amino acid residue, Tyr316, that played a crucial role in maintaining STIM1 in a closed conformation in quiescent cells. Full-length STIM1-Y316A formed constitutive clusters near the plasma membrane and activated the CRAC channel in the resting state when co-expressed with Orai1. The introduction of a Y316A mutation caused the higher-order oligomerization of the in vitro purified STIM1 fragment containing both the auto-inhibitory domain and CAD (CRAC-activating domain). We propose that the Tyr316 residue may be involved in the auto-inhibitory mechanism of the STIM1 C-terminus in the quiescent state. This inhibition could be achieved either by interacting with the CAD using hydrogen and/or hydrophobic bonds, or by an intermolecular interaction using repulsive forces, which maintained a dimeric STIM1.

Solid-state diffusion bonding of commercially pure titanium to 304 stainless steel using an Ag interlayer was carried out at 825–875 °C under a uniaxial pressure of 8 MPa for 20 min in vacuum. The microstructural observations revealed that the resultant joints were composed of the remnant Ag interlayer, TiAg intermetallic phase and Ti–Ag solid solution. An optimized bonding strength of up to 414 MPa was achieved. Fracture took place through the remnant Ag interlayer during tensile tests and the interfacial TiAg phase exhibited no detrimental effect on the bonding strength. Extensive dimples were observed on the fracture surfaces, indicating that the joints were ductile in nature.

One of the principal functions of the trans Golgi network (TGN) is the sorting of proteins into distinct vesicular transport carriers that mediate secretion and interorganelle trafficking. Are lipids also sorted into distinct TGN-derived carriers? The Golgi is the principal site of the synthesis of sphingomyelin (SM), an abundant sphingolipid that is transported. To address the specificity of SM transport to the plasma membrane, we engineered a natural SM-binding pore-forming toxin, equinatoxin II (Eqt), into a nontoxic reporter termed Eqt-SM and used it to monitor intracellular trafficking of SM. Using quantitative live cell imaging, we found that Eqt-SM is enriched in a subset of TGN-derived secretory vesicles that are also enriched in a glycophosphatidylinositol-anchored protein. In contrast, an integral membrane secretory protein (CD8α) is not enriched in these carriers. Our results demonstrate the sorting of native SM at the TGN and its transport to the plasma membrane by specific carriers.

In the study, the plant-mix cold recycling technology of foamed asphalt (PCRTFA) was applied to a reconstruction project of a highway in Hainan province, China. The mix proportions of the raw materials and related parameters of PCRTFA were analyzed firstly. Then, the pavement construction test was carried out. After that, the reconstruction project of the highway was performed. At last, the construction technology and quality control were expounded. The case study shows that the PCRTFB can achieve the purpose of reusing resources and save construction costs. This study can provide technical reference for other similar pavement reconstruction projects in Hainan province.

The aim of this study was to investigate the clinical results and efficacy of an arthroscopic approach to correct anterior displacement of the disc without reduction of the temporomandibular joint (TMJ) with limitation of mouth opening. We studied 28 joints with internal derangement in 23 patients, all of whom had had arthroscopic surgery (lavage, lysis of adhesions in the superior compartment, incision parallel to the disc-synovial crease of the upper joint compartment, and pull back of the anteriorly located disc). Objective and subjective data (increase in maximal interincisal opening, magnetic resonance imaging, and visual analogue pain score, VAS) were collected preoperatively and at 7, 30, 60 days, and 6 months or more postoperatively. Maximal interincisal opening improved from a mean (SD) of 20.4 (±4.5) mm preoperative measurement to 38.9 (±3.2) mm by 6 months postoperatively where indicated in previous line. The VAS showed a significant improvement in pain score (p=0.0023). Sixty days postoperatively the positions of the discs in 14 of the TMJs had improved considerably. In 13 of the TMJs the positions had improved slightly. Only 1 of the TMJs had not improved at all. There were no complications in any patient. Our arthroscopic procedure is safe, minimally invasive, and effective for the treatment of patients with displacement of the disc anteriorly without reduction of the TMJ.

Summary How the principal functions of the Golgi apparatus—protein processing, lipid synthesis, and sorting of macromolecules—are integrated to constitute cargo-specific trafficking pathways originating from the trans-Golgi network (TGN) is unknown. Here, we show that the activity of the Golgi localized SPCA1 calcium pump couples sorting and export of secreted proteins to synthesis of new lipid in the TGN membrane. A secreted Ca2+-binding protein, Cab45, constitutes the core component of a Ca2+-dependent, oligomerization-driven sorting mechanism whereby secreted proteins bound to Cab45 are packaged into a TGN-derived vesicular carrier whose membrane is enriched in sphingomyelin, a lipid implicated in TGN-to-cell surface transport. SPCA1 activity is controlled by the sphingomyelin content of the TGN membrane, such that local sphingomyelin synthesis promotes Ca2+ flux into the lumen of the TGN, which drives secretory protein sorting and export, thereby establishing a protein- and lipid-specific secretion pathway.

Insulin stimulates GLUT4 (glucose transporter 4) translocation in adipocytes and muscles. An emerging picture is that Rab10 could bridge the gap between the insulin signalling cascade and GLUT4 translocation in adipocytes. In the present study, two potential effectors of Rab10, GDI (guanine-nucleotide-dissociation inhibitor)-1 and GDI-2, are characterized in respect to their roles in insulin-stimulated GLUT4 translocation. It is shown that both GDI-1 and GDI-2 exhibit similar distribution to GLUT4 and Rab10 at the TGN (trans-Golgi network) and periphery structures. Meanwhile, GDI-1 clearly interacts with Rab10 with higher affinity, as shown by both immunoprecipitation and in vivo FRET (fluorescence resonance energy transfer). In addition, the participation of GDIs in GLUT4 translocation is illustrated when overexpression of either GDI inhibits insulin-stimulated GLUT4 translocation in 3T3-L1 adipocytes. Taken together, we propose that GDI-1 is preferentially involved in insulin-stimulated GLUT4 translocation through facilitating Rab10 recycling.

Herein, we report on the preparation and characterization of polyimide (PI) membranes containing Ag nanoparticles in pores distributing on one side. The presence of the Ag nanoparticles in the pores was confirmed by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Plasma Emission Spectrometer. The results showed that the pores distributed on bottom side of the membranes, and the Ag nanoparticles dispersed evenly on the wall of the pores. The pores provided excellent dispersing environment for the Ag nanoparticles. The quantities and dispersing densities of Ag nanoparticles are larger when they are prepared from silver nitrate (AgNO3) solutions with higher concentration.

We report experimental results on the temperature dependence of band gap in size-controlled CdSe nanocrystals. Such temperature-dependent property is also size-dependent. Within a certain temperature range, the band gap absorption peak position ( λ in nm) of CdSe nanocrystals with a given particle size ( D ) can be expressed as a simple linear function of temperature ( T in K): λ = 0.1 T + C ( D , 298 K). This function is practically applicable to any particle size and temperature. A comparison reveals that the band gap values calculated using this function are in agreement with the experimental ones reported previously.

Herein, we report on direct preparation of macroporous polyimide (PI) films with pores distributing on one side, the method of which relies on sedimentation of ceramic spheres in polyamic acid (PAA) solutions in a gravitational field and imidization of PAA/ceramic spheres mixtures to obtain PI/ceramic spheres hybrid films followed by curing in dilute hydrofluoric (HF) acid. In this strategy, the curing of the hybrid films in HF acid leads to the formation of pores. The introduction of pores makes the room-temperature dielectric constants of the macroporous films lower than that of pure PI film. Moreover, the macroporous PI films have improved Young's moduli and higher thermal stability in nitrogen atmosphere. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 261–266, 2007

Short tandem repeats (STRs) and single nucleotide polymorphisms (SNPs) have been already used to perform noninvasive prenatal paternity testing from maternal plasma DNA. The frequently used technologies were PCR followed by capillary electrophoresis and SNP typing array, respectively. Here, we developed a noninvasive prenatal paternity testing (NIPAT) based on SNP typing with maternal plasma DNA sequencing. We evaluated the influence factors (minor allele frequency (MAF), the number of total SNP, fetal fraction and effective sequencing depth) and designed three different selective SNP panels in order to verify the performance in clinical cases. Combining targeted deep sequencing of selective SNP and informative bioinformatics pipeline, we calculated the combined paternity index (CPI) of 17 cases to determine paternity. Sequencing-based NIPAT results fully agreed with invasive prenatal paternity test using STR multiplex system. Our study here proved that the maternal plasma DNA sequencing-based technology is feasible and accurate in determining paternity, which may provide an alternative in forensic application in the future.

The signaling adaptor TRAF3 is a highly versatile regulator of both innate immunity and adaptive immunity, but how its phosphorylation is regulated is still unknown. Here we report that deficiency in or inhibition of the conserved serine-threonine kinase CK1ɛ suppressed the production of type I interferon in response to viral infection. CK1ɛ interacted with and phosphorylated TRAF3 at Ser349, which thereby promoted the Lys63 (K63)-linked ubiquitination of TRAF3 and subsequent recruitment of the kinase TBK1 to TRAF3. Consequently, CK1ɛ-deficient mice were more susceptible to viral infection. Our findings establish CK1ɛ as a regulator of antiviral innate immune responses and indicate a novel mechanism of immunoregulation that involves CK1ɛ-mediated phosphorylation of TRAF3.

Design of a temperature sensing system for downhole application is facilitated by finite element analysis in this study, to research the temperature distribution of downhole in oil well. To deal with inaccuracy of mesh error in consideration of high aspect ratio of the oil well, we divided the well into multiple 500 meters - length pieces, each one of which was divided into 10 computing segments for feasibility of simulation with reduced complexity. Temperature distribution simulation of our proposed system prototype to work at 3k meters under the ground surface are analyzed as reported. We formatted an important power function equation for describing relationship between delta temperature (temperature gradient) and the segments; and the equation predicted ∼38k temperature difference between the temperature at 3k depth and the exit of the oil well.

Metal grid transparent conductive electrodes have been developed by traditional printing techniques, but lower resolution of grid line has limited its performance. In this study, conductive grid patterns with ~10 µm width were created on the polyethylene terephthalate (PET) substrate by microcontact printing (µCP) silver nanoparticles ink. We have found that the composition of silver nanoparticles ink and the O2 plasma treated time of polydimethylsiloxane (PDMS) stamp were critical for the µCP process. Specially, the hole size of stamp has great influence on the patterns shape when using grid-structured stamp. This is because the break of liquid bridge formed between two adjacent lines of stamp depends on the hole size of stamp during the dry process of ink. Larger hole was beneficial for the formation of grid patterns with smooth edge. Conductive grid patterns with typical sheet resistance of 610 Ω/ and 74% transparency were acquired over the entire 1 cm square area using 40 µm hole stamp. This method will lead to a facile strategy to prepare conductive electrode.

This article conducts a research on wheel slip ratio control for distributed drive electric vehicles. In consideration of wheel rotation dynamics and its strong nonlinear properties, a proportional–integral controller is designed in this paper aimed at regulating the wheel slip ratio to a constant value regardless of the road adhesion conditions. At the same time, an online road coefficient estimator is proposed to provide optimal slip ratio for the designed wheel slip ratio controller. The global asymptotic stability of the system is proved by the Lyapunov stability theory. In addition, a distributed drive electric vehicle model is established for performance assessment due to its precise and fast-response torque control. Simulation results show that the proposed controller adaptively regulates the wheel slip ratio to the optimal value of current road with fast convergence speed and high accuracy. Generally, the proposed adaptive controller greatly improves the driving performance of the electric vehicle.

Through applying the liquid metal and elastomer as the core and shell materials, respectively, a coaxial printing method is being developed in this work for preparing a stretchable and conductive cable. When liquid metal alloy eutectic Gallium-Indium is embedded into the elastomer matrix under optimized control, the cable demonstrates well–posed extreme mechanic performance, under stretching for more than 350%. Under developed compression test, the fabricated cable also demonstrates the ability for recovering original properties due to the high flowability of the liquid metal and super elasticity of the elastomeric shell. The written cable presents high cycling reliability regarding its stretchability and conductivity, two properties which can be clearly predicted in theoretical calculation. This work can be further investigated as a strain sensor for monitoring motion status including frequency and amplitude of a curved object, with extensive applications in wearable devices, soft robots, electronic skins, and wireless communication.

Rab10 activation promotes GLUT4 storage vesicle recruitment to the plasma membrane in response to insulin and coordinates with myosin-Va to mediate vesicle fusion., Rab proteins are important regulators of insulin-stimulated GLUT4 translocation to the plasma membrane (PM), but the precise steps in GLUT4 trafficking modulated by particular Rab proteins remain unclear. Here, we systematically investigate the involvement of Rab proteins in GLUT4 trafficking, focusing on Rab proteins directly mediating GLUT4 storage vesicle (GSV) delivery to the PM. Using dual-color total internal reflection fluorescence (TIRF) microscopy and an insulin-responsive aminopeptidase (IRAP)-pHluorin fusion assay, we demonstrated that Rab10 directly facilitated GSV translocation to and docking at the PM. Rab14 mediated GLUT4 delivery to the PM via endosomal compartments containing transferrin receptor (TfR), whereas Rab4A, Rab4B, and Rab8A recycled GLUT4 through the endosomal system. Myosin-Va associated with GSVs by interacting with Rab10, positioning peripherally recruited GSVs for ultimate fusion. Thus, multiple Rab proteins regulate the trafficking of GLUT4, with Rab10 coordinating with myosin-Va to mediate the final steps of insulin-stimulated GSV translocation to the PM.

The Ca(2+) release-activated Ca(2+) (CRAC) channel pore is formed by Orai1 and gated by STIM1 after intracellular Ca(2+) store depletion. To resolve how many STIM1 molecules are required to open a CRAC channel, we fused different numbers of Orai1 subunits with functional two-tandem cytoplasmic domains of STIM1 (residues 336-485, designated as S domain). Whole-cell patch clamp recordings of these chimeric molecules revealed that CRAC current reached maximum at a stoichiometry of four Orai1 and eight S domains. Further experiments indicate that two-tandem S domains specifically interact with the C-terminus of one Orai1 subunit, and CRAC current can be gradually increased as more Orai1 subunits can interact with S domains or STIM1 proteins. Our data suggest that maximal opening of one CRAC channel requires eight STIM1 molecules, and support a model that the CRAC channel activation is not in an "all-or-none" fashion but undergoes a graded process via binding of different numbers of STIM1.

To investigate the effect of the well-defined RNA elements (VR, RCS2, CS2, CS1 and SL) within the 3'untranslated region (UTR) on dengue virus (DEN) translation.We constructed a virus induced reporter gene (VIRG) by inserting the firefly luciferase (LUC) gene between 5'- and 3'-UTRs of DEN2-43 genome. Subsequently, a series of modified VIRGs consisting of different RNA elements in the 3'UTR were constructed. A 3'UTR-deficient VIRG was also constructed. The translational efficiency of all VIRGs was then analyzed by LUC detection, real time RT-PCR and Western blot assays.The translation of 3'UTR-deficient VIRG was abolished. The translational efficiency of VIRG with RNA element VR was comparable with that of VIRG with unmodified 3'UTR. The translational efficiency of VIRG with RNA elements RCS2 or CS2 was significantly higher while the translational efficiency of VIRG with RNA elements CS1 or SL was substantially lower than that of VIRG with RNA element VR.These results suggested that 3'UTR was indispensable for DEN translation, and some RNA elements within 3'UTR might either up-regulate or down- regulate translation.

In this paper, we propose a novel unitary downlink precoding design scheme for multiuser (MU) spatial multiplexing (SM) multiple-input multiple-output (MIMO) systems. With the perfect channel state information (p-CSI) available at the transmitter and the linear decoder at the receiver, we construct the cost function based on the minimum average probability of vector symbol error (APVSE) and give the design method of the precoding matrices. Our proposed precoding matrices can completely eliminate co-channel interference (CCI) for each user at the transmitter, and each terminal user will eventually observe an interference-free single-user (SU) channel, thus simplify the decoding of each terminal user. Finally, we derive the upper bound APVSEs of several schemes for performance comparison and the latter simulation results have shown that our proposed downlink precoding for MU SM MIMO system obtains the almost same performance as the SU precoding system.

In this paper a method using quadratic congruential sequences to design regular LDPC code is proposed. The main advantage of this method is that the structure of the encoder can be generated using a determined recursion, rather than having to store the encoder structure graph in memory, which facilitates hardware implementation. Simulation results show that these codes provide almost the same performance of a constrained pseudorandom construction that explicitly avoids cycles of length less than or equal to four.

A plasmonic lens composed of a dielectric-filled nanoslits structure on an aluminum film is proposed and experimentally demonstrated. The slits' structure is designed with equal distance, length, and width, but filled with variant thickness SiO2 dielectric for specific phase retardations. A dual focused ion beam instrument is employed to mill the slits and deposit SiO2 into the slits. The phase modulation by SiO2-filled slits is illustrated by a double slits interference experiment. The light focusing behavior of the fabricated plasmonic lens is experimentally characterized by a scanning near-field optical microscope. Experimental results show good agreement with the simulations. (C) 2014 Society of Photo-Optical Instrumentation Engineers (SPIE).

Ultra-low coverage sequencing (ULCS) is one of the most promising strategies for sequencing based clinical application. These clinical applications, especially prenatal diagnosis, have a strict requirement of turn-around-time; therefore, the application of ULCS is restricted by current high throughput sequencing platforms. Recently, the emergence of rapid sequencing platforms, such as MiSeq and Ion Proton, brings ULCS strategy into a new era. The comparison of their performance could shed lights on their potential application in large-scale clinic trials. In this study, we performed ULCS (