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A persistent mystery in the melanoma field has been the function of one of the first melanoma tumor antigens characterized, namely p97 (melanotransferrin; MTf). While MTf expression increases melanoma cell proliferation, migration, and tumorigenesis, the molecular mechanism responsible is unknown. On the other hand, N-myc down-stream regulated gene 1 (NDRG1) is a potent metastasis suppressor and WNT antagonist. Expression of NDRG1 in melanoma cells suggests a role in inhibiting metastasis, with this study investigating MTf’s role in oncogenic signaling. We demonstrate MTf acts as a pro-oncogenic WNT agonist, which down-regulates NDRG1, while silencingMTfincreases NDRG1 expression. In contrast, silencingNDRG1increases MTf expression. These observations demonstrate a bidirectional negative feedback loop and “Yin-Yang” relationship between MTf and NDRG1. Mechanistically, MTf was directly associated with the WNT co-receptor, lipoprotein-receptor 6 (LRP6), and increased total LRP6 expression, activated p-LRP6 (Ser1490), β-catenin, and activated β-catenin (Ser552) levels, with MTf expression inducing their nuclear accumulation. Additionally, MTf expression increased downstream WNT targets, namely cyclin D1 and c-Myc, with c-Myc down-regulating NDRG1 expression. Silencingc-Mycprevented the Yin-Yang relationship between NDRG1 and MTf, indicating c-Myc played a key role in their inverse regulation. Melanoma patient specimens demonstrated that a low NDRG1/MTf ratio was significantly (p= 0.008) associated with lower survival and metastasis. Chemotherapeutic agents that up-regulated NDRG1 depressed MTf and nuclear LRP6 and potently inhibited melanoma xenograft growthin vivo. This study demonstrates MTf acts as a WNT agonist, with a Yin-Yang relationship being observed with the WNT antagonist, NDRG1.

Strelitzia reginae is a popular cut flower that has blue petals and orange sepals. Flower color is an important plant trait; however, little is known about its molecular mechanisms in S. reginae. In this study, cDNA libraries were constructed for blue petals and orange sepals of S. reginae. A total of 75 487 unigenes were obtained from transcriptome sequencing and de novo assembly, of which 41.86 % were annotated by public databases. Ultra-high performance liquid chromatography analysis revealed that anthocyanins were the main pigment in blue petals, and that carotenoids controled pigment formation in the orange sepals. Using a system analysis-based approach, 73 and 29 candidate genes related to anthocyanin and carotenoid biosyntheses were identified, respectively. Among these, chalcone synthase 2, chalcone isomerase 1, flavanone 3-hydroxylase 1, flavonoid 3',5'-hydroxylase 1, dihydroflavonol 4-reductase 1, anthocyanidin synthase 1, and anthocyanidin 3-O-glucosyltransferase 1 were considered to be important in regulating the formation of blue petals, and phytoene synthase 1, phytoene desaturaser 1, ζ-carotene desaturase 1, lycopene β-cyclase 3, and β-carotene hydroxylase 2 might play important roles in orange sepal formation. This study improves our understanding of flower color and provides evidence for future molecular breeding of ornamental plants based on flower color modifications.

The preferred orientation full intermetallic compound (IMC) interconnects were fabricated using the current driven bonding (CDB) method. The electromigration behavior and mechanical properties of the (001) Cu/IMC(30 µm Cu6Sn5)/Cu interconnects under a current density of 2.0×10^4 A/cm2 at 150 °C and 180 °C were investigated. The Cu/Cu6Sn5/Cu IMC interconnects exhibited an excellent electromigration resistance, since there was no obvious damage after aging at 150 °C and 180 °C for 200 h, and even after electromigration under 2.0×10^4 A/cm2 at 150 °C and 180 °C for 200 h. The microstructural evolution of the Cu/Cu6Sn5/Cu IMC interconnects undergoing aging and electromigration was mainly the growth of interfacial Cu3Sn and formation of Kirkendall voids in Cu3Sn. Electromigration significantly accelerated the growth of interfacial Cu3Sn IMCs compared with aging, and there was no obvious "polarity effect" for the growth of interfacial Cu3Sn IMCs undergoing electromigration. The Cu/Cu6Sn5/Cu IMC interconnects had a high mechanical reliability even undergoing high temperature aging and high current stressing (electromigration). The average tensile strength of full IMC interconnects remained unchanged, i.e., 82.0 MPa and 81.8 MPa, even after aging at 150 °C for 300 h and electromigration (2.0×10^4 A/cm2) at 150 °C for 300 h, respectively, which were similar to that of the as-soldered state (86.7 MPa). However, the microstructural degradation of traditional Sn-3.0Ag-0.5Cu solder interconnects undergoing electromigration was greatly serious, and the Sn-3.0Ag-0.5Cu solder interconnects failed even after electromigration at 150 oC for less than 100 h. The present work is expected to provide a guidance for the promising application of the preferred orientation full IMC interconnects in 3D integrated circuits packaging.

Line-type Cu/Sn/Ni and Cu/Sn/Ni-P interconnects as well as real Ni/Sn3.0Ag0.5Cu/Cu and Ni/Sn3.0Ag0.5Cu/Ni-P flip chip solder joints were comparatively studied to reveal the electromigration reliability of solder joints. The experimental results of the line-type solder interconnects showed that Cu could diffuse to the opposite anode Ni interface and change the interfacial IMC type while Ni could not change IMC type at the opposite anode Cu interface under a current density of 1×104A/cm2 at 150 oC. In real flip chip solder joints, the EM life of Cu (OSP) solder joints was significantly longer than that of Ni-P (ENEPIG) solder joints. A higher Cu content in the solder bumps effectively improved the electromigration resistance of solder joints. This work provides a suggestion for optimizing the structure of flip chip solder joints.

Without using any interfacial passivation layers, high- κ dielectric Y 2 O 3 , HfO 2 , and Ga 2 O 3 (Gd 2 O 3 ) [GGO], by electron beam evaporation in ultra-high-vacuum (UHV), have been directly deposited on Ge substrate. Comprehensive investigations have been carried out to study the oxide/Ge interfaces chemically, structurally, and electronically: hetero-structures of all the studied oxides on Ge are highly thermally stable with annealing to 500 °C, and their interfaces remain atomically sharp. The electrical analyses have been conducted on metal–oxide–semiconductor (MOS) devices, i.e. MOS capacitors (MOSCAPs) and MOS field-effect-transistors (MOSFETs). Dielectrics constants of the Y 2 O 3 , HfO 2 , and GGO have been extracted to be ∼17, 20, and 13–15, respectively, indicating no interfacial layer formation with 500 °C annealing. A low interfacial density of states ( D it s), as low as 3 × 10 11 cm −2 eV −1 , has been achieved for GGO/Ge near mid-gap along with a high Fermi-level movement efficiency as high as 80%. The GGO/Ge pMOSFETs with TiN as the metal gate have yielded very high-performances, in terms of 496 μA/μm, 178 μS/μm, and 389 cm 2 /V s in saturation drain current density, maximum transconductance, and effective hole mobility, respectively. The gate width and gate length of the MOSFET are 10 μm and 1 μm.

Self-diffusion of nickel and manganese has been investigated by the radiotracer technique in Ni50Mn50 alloys over a wide temperature range. Experiments were performed on disordered fcc, B2 and L10 structure phases present in the equiatomic alloy at high, intermediate, and low temperatures, respectively. The diffusivity of manganese was found to be significantly faster (factor 3 to 5) than that of nickel in the fcc and B2 phases. More than one order of magnitude diffusivity increase was observed upon the transition from the higher temperature fcc to the intermediate temperature B2 phase. The activation enthalpy from nickel self-diffusion in the disordered fcc phase is significantly higher than the corresponding value for manganese. In the B2 phase there is only a slight difference between the activation enthalpies of the components, which indicates a coupled diffusion mechanism of the two components. A comparison of the present tracer self-diffusion data with literature data on interdiffusion in the Ni-Mn system permits to estimate thermodynamic factors by using the Darken-Manning equation. The thermodynamic factor varies from 3 to 5 depending on the structure.

It was reported in a previous study that the Sn-6Bi-2Ag-0.5Cu solder alloy had great potential to replace leaded alloys. This alloy was prepared by mechanical alloying, and had the advantage of providing a high percentage of supersaturate solution of bismuth in tin. In the present paper, the microstructural evolution of surface-mount joints during aging was examined. In the as-soldered joints, small bismuth and Ag3Sn particles of about 1 mum in size were found to be finely dispersed in a nearly pure tin matrix with a small amount of eta-Cu6Sn5 phase in the bulk of solder. During aging, microstructural evolution of solder joints occurred. These include Cu-Sn intermetallic compound (IMC) layer growth at the interface between solder and copper pad on the printed circuit board, as well as bismuth phase and Ag3Sn phase coarsening. The shear strength of the solder joints decreased parabolically with the increase in IMC layer thickness, such that taus=22.22-radic22.05(t-1.88), where taus is the shear strength in MPa and t (>1.88) is the total IMC layer thickness in micrometers. The microstructure of solder appeared to be stable under aging at elevated temperatures up to about 160degC. Above this temperature, brittle and porous IMC epsiv-Cu3Sn appeared at the copper/eta-Cu6Sn 5 interface. Fracture was found to occur at the Cu-Sn IMC layer-solder interface and in the bulk of solder

In this paper the scalability of ALD HfO2 in passivating high indium content InGaAs were studied. A capacitance equivalent thickness (CET) of 1.0 nm has been achieved in this work without any surface pretreated process.

In this paper, there is no surface cleaning and interfacial passivation layer prior to the ALD-HfO2. However, the oxide/InGaAs interface is atomically sharp without the existence of arsenic oxides, strongly indicating self-cleaning of the ALD process. Excellent well-behaved J-EG and C-V characteristics of ALD-HfO2/In0.53Ga0.47As/InP have been demonstrated in this work.

Energy efficient wireless communication system is the key to the future. The goal of this paper is to maximize the energy efficiency performance of a wireless communication system within the IEEE 802.11 standards. The distributed coordination function (DCF) of IEEE 802.11 medium access control (MAC) provides two fundamental access modes, namely 2-way (basic access) and 4-way (RTS/CTS) frame exchange modes. We applied a fair 802.11h transmit power control (TPC) based power-rate adaptive scheme to both DCF access modes and propose a novel and effective strategy that allows any wireless stations to switch between the two access modes based on network conditions to achieve a truly energy efficient system. We analyze and compare the energy efficiency of 2-way and 4-way access modes with our proposed adaptive energy efficient scheme and our simulation results show that our proposed strategy gives a more superior performance in system energy utilization, by achieving an average of 20% Mbits/Joule gain compared to a rate-adaptive 2-way or 4-way DCF access mode for a ten-stations network.

In this paper, the study on the relationship between green assembly material properties and failure mechanism of moisture sensitivity reliability are reported. It focuses on the JEDEC level 2 and 3 precondition conditions that are 85/spl deg/C, 60%RH for 168hrs and 30/spl deg/C, 60RH% for 192 hrs, respectively. Besides, the paper discusses the process parameters and relative material influences. For instance, package block warpage and compound moisture absorption effects. Cure kinetic and thermal resistances of the green compound were analyzed by differential scanning calorimetry (DSC) and thermo gravimetric analysis (TGA), respectively. On the surfaces of delamination of reliability test specimens, which are analysis by scanning electron microscope (SEM) and scanning acoustic tomograph (SAT). The remainder flux amount at melt range of lead free solder affects circularity of solder ball dramatically. Furthermore, block warpage and moisture sensitivity reliability results reveal some conflict between process and reliability request. The compound with higher filler content relatively with less resin ratio exhibits larger block warpage and lower moisture uptake, respectively. That conducts poor facility during process and good performances in reliability test.