In situ nitridation of titanium–molybdenum alloys during laser deposition

In situ nitridation during laser deposition of titanium–molybdenum alloys from elemental powder blends has been achieved by introducing the reactive nitrogen gas during the deposition process. Thus, Ti–Mo–N alloys have been deposited using the laser engineered net shaping (LENS^TM) process and resulted in the formation of a hard α(Ti,N) phase, exhibiting a dendritic morphology, distributed within a β(Ti–Mo) matrix with fine scale transformed α precipitates. Varying the composition of the Ar + N₂ gas employed during laser deposition permits a systematic increase in the nitrogen content of the as-deposited Ti–Mo–N alloy. Interestingly, the addition of nitrogen, which stabilizes the α phase in Ti, changes the solidification pathway and the consequent sequence of phase evolution in these alloys. The nitrogen-enriched hcp α(Ti,N) phase has higher c/a ratio, exhibits an equiaxed morphology, and tends to form in clusters separated by ribs of the Mo-rich β phase. The Ti–Mo–N alloys also exhibit a substantial enhancement in microhardness due to the formation of this α(Ti,N) phase, combining it with the desirable properties of the β-Ti matrix, such as excellent ductility, toughness, and formability.     

High-throughput detection and sizing of individual low-index nanoparticles and viruses for pathogen identification

Rapid, chip-scale, and cost-effective single particle detection of biological agents is of great importance to human health and national security. We report real-time, high-throughput detection and sizing of individual, low-index polystyrene nanoparticles and H1N1 virus. Our widefield, common path interferometer detects nanoparticles and viruses over a very large sensing area, orders of magnitude larger than competing techniques. We demonstrate nanoparticle detection and sizing down to 70 nm in diameter. We clearly size discriminate nanoparticles with diameters of 70, 100, 150, and 200 nm. We also demonstrate detection and size characterization of hundreds of individual H1N1 viruses in a single experiment.     

Effects of a a-Si:H layer on reducing the dark current of 1310 nm metal-germanium-metal photodetectors

Two approaches of hydrogenated-amorphous-silicon (a-Si:H), as Schottky-barrier height (SBH) enhancement and passivation layers, were investigated to suppress dark current of 1310 nm metal-germanium-metal photodetectors (MGM-PDs). Observations show that when a-Si:H is inserted between metal and Ge, the dark current is effectively reduced due to SBH enhancement, but similarly lowers photocurrent resulting from the blocking of a-Si:H. In contrast with a-Si:H acting as a passivation layer a very high photo-to-dark current ratio of 6530 is achieved with a high responsivity of 0.72 A/W, attributing to the defect centers on the Ge surface which are passivated. Such a result suggests that the a-Si:H passivation layer is a good candidate in fabricating high-quality 1310 nm MGM-PDs.     

A hierarchical test methodology for systems on chip

We present a hierarchical test methodology for testing a SOC with heterogeneous cores, including the 1149.1-wrapped, P1500-wrapped, and BIST memory cores. We propose an 1149.1-based hierarchical test manager that also provides P1500 test control signals. This scheme includes a memory BIST interface, providing both serial and parallel access ports for BIST circuits. Our approach offers low area and pin overhead, and high flexibility     

A Fully-Human Antibody Specifically Targeting a Membrane-Bound Fragment of CADM1 Potentiates the T Cell-Mediated Death of Human Small-Cell Lung Cancer Cells

Small-cell lung cancer (SCLC) is the most aggressive form of lung cancer and the leading cause of global cancer-related mortality. Despite the earlier identification of membrane-proximal cleavage of cell adhesion molecule 1 (CADM1) in cancers, the role of the membrane-bound fragment of CAMD1 (MF-CADM1) is yet to be clearly identified. In this study, we first isolated MF-CADM1-specific fully human single-chain variable fragments (scFvs) from the human synthetic scFv antibody library using the phage display technology. Following the selected scFv conversion to human immunoglobulin G1 (IgG1) scFv-Fc antibodies (K103.1–4), multiple characterization studies, including antibody cross-species reactivity, purity, production yield, and binding affinity, were verified. Finally, via intensive in vitro efficacy and toxicity evaluation studies, we identified K103.3 as a lead antibody that potently promotes the death of human SCLC cell lines, including NCI-H69, NCI-H146, and NCI-H187, by activated Jurkat T cells without severe endothelial toxicity. Taken together, these findings suggest that antibody-based targeting of MF-CADM1 may be an effective strategy to potentiate T cell-mediated SCLC death, and MF-CADM1 may be a novel potential therapeutic target in SCLC for antibody therapy.     

Simple K-band MMIC VCO utilizing a miniaturized hairpin resonator and a three-terminal p-HEMT varactor with low phase noise and high output power properties

Presents a fully monolithic K-band MMIC voltage-controlled oscillator (VCO) implemented by using a 0.25 /spl mu/m AlGaAs/InGaAs pseudomorphic HEMT (p-HEMT) technology. The use of a half-wavelength miniaturized hairpin-shaped resonator and a three-terminal p-HEMT varactor was effective in reducing the chip size and simplifying fabrication processes of the microwave MMIC VCO without impairing the performance of the circuit. The VCO provides a typical output power of 11.5 dBm at 20.8 GHz and a free-running phase noise of -82 dBc/Hz at 100 kHz offset and -95 dBc/Hz at 1 MHz offset. It also shows a tuning range of 70 MHz with little reduction in output power and high yield properties. The chip size of the MMIC VCO is 1.5 /spl times/ 2.0 mm/sup 2/.     

Cavity length and absorption dependent longitudinal beat in iodine photodissociation laser

As the cavity length of the iodine photodissociation laser (iodine PDL) is varied, the number of neighboring coherent modes increases and the time-dependent mode-competition effect gives rise to typical changes in the pulse shape. The ratio of the number of all coherent modes to that of all oscillating modes is found to be as high as 80 percent when the cavity length is 450 cm. The frequency width in which the neighboring modes are coherent is approximately 0.1 GHz for all cavity lengths used. The effect of a BDN absorber placed in the cavity is distinct in the shorter cavities.     

Neural-network-based variable structure control of electrohydraulicservosystems subject to huge uncertainties without persistent excitation

A novel scheme investigating a radial-basis-function neural network (RBFNN) with variable structure control (VSC) for electrohydraulic servosystems subject to huge uncertainties is presented. Although the VSC possesses some advantages (e.g., fast response, less sensitive to uncertainties, and easy implementation), the chattering control input often occurs. The reason for a chattering control input is that the switching control in the VSC is used to cope with the uncertainties. The larger the uncertainties which arise, the larger switching control occurs. In this paper, an RBFNN is employed to model the uncertainties caused by parameter variations, friction, external load, and controller. A new weight updating law using a revision of e-modification by a time varying dead zone can achieve an exponential stability without the assumption of persistent excitation for the uncertainties or radial basis function. Then, an RBFNN-based VSC is constructed such that some part of uncertainties are tackled, that the tracking performance is improved, and that the level of chattering control input is attenuated. Finally, the stability of the overall system is verified by the Lyapunov stability criterion     

Carbon Metabolism of a Soilborne Mn(II)-Oxidizing Escherichia coli Isolate Implicated as a Pronounced Modulator of Bacterial Mn Oxidation

Mn(II)-oxidizing microorganisms are generally considered the primary driving forces in the biological formation of Mn oxides. However, the mechanistic elucidation of the actuation and regulation of Mn oxidation in soilborne bacteria remains elusive. Here, we performed joint multiple gene-knockout analyses and comparative morphological and physiological determinations to characterize the influence of carbon metabolism on the Mn oxide deposit amount (MnODA) and the Mn oxide formation of a soilborne bacterium, Escherichia coli MB266. Different carbon source substances exhibited significantly varied effects on the MnODA of MB266. A total of 16 carbon metabolism-related genes with significant variant expression levels under Mn supplementation conditions were knocked out in the MB266 genome accordingly, but only little effect on the MnODA of each mutant strain was accounted for. However, a simultaneous four-gene-knockout mutant (namely, MB801) showed an overall remarkable MnODA reduction and an initially delayed Mn oxide formation compared with the wild-type MB266. The assays using scanning/transmission electron microscopy verified that MB801 exhibited not only a delayed Mn-oxide aggregate processing, but also relatively smaller microspherical agglomerations, and presented flocculent deposit Mn oxides compared with normal fibrous and crystalline Mn oxides formed by MB266. Moreover, the Mn oxide aggregate formation was highly related to the intracellular ROS level. Thus, this study demonstrates that carbon metabolism acts as a pronounced modulator of MnODA in MB266, which will provide new insights into the occurrence of Mn oxidation and Mn oxide formation by soilborne bacteria in habitats where Mn(II) naturally occurs.