Adenoviral-mediated suicide gene therapy for hepatic metastases of breast cancer

Metastases of breast cancer are a major cause of treatment failure. To evaluate the therapeutic efficacy of suicide gene therapy in metastatic breast cancer, we used the herpes simplex virus thymidine kinase (HSV-tk) gene followed by ganciclovir (GCV) administration to treat breast cancer, generated by an adenocarcinoma cell line MOD in syngeneic mice. The bystander effect of HSV-tk + GCV on tumor cell killing was illustrated by demonstrating complete regression of subcutaneous tumors consisting of 90% parental tumor cells and 10% HSV-tk transformed tumor cells. To establish a model of breast cancer metastases in the liver, tumors were generated by intra-hepatic implantation of MOD cells in syngeneic animals. Two weeks after tumor cell implantation, replication defective adenoviral vectors expressing HSV-tk (ADV.tk), or beta-galactosidease (ADV. beta-Gal) were injected intratumorally, followed by buffer or GCV administration. Treatment with ADV.tk + GCV resulted in significant regression of tumor (P < .001), as assessed by computerized morphometric analysis of residual tumor. This was reflected as a significant prolongation of survival in treated animals (P < .001). These results demonstrate that ADV-mediated suicide gene therapy in vivo can be incorporated in a comprehensive treatment strategy for liver metastases of breast cancer.     

Mineral matter as a measure of oxidation of a coking coal

The petrography, agglomerating characteristics, low-temperature ash (LTA) mineralogy and chemistry of ten consecutive channel samples from D seam, Natal Ridge, Crowsnest coalfield, British Columbia, were compared. It was found that there is a direct correlation between oxidation, as indicated by absence or limited caking character, and the presence of the mineral bassanite ($\text{CaS0}{}_4\text{·}\text{1}\text{2}\text{H}{}_2\text{O}$) in LTA. An attempt to estimate quantitatively the extent of oxidation by the anhydrite content in LTA samples further heated to 500 °C has resulted in the detection of partial oxidation of a coal sample having an FSI of $\text{6}\text{1}\text{2}$, reduced from a normal value of 8. The recognition and quantification of oxidation using epigenetic gypsum and its derivatives, however, probably only applies to the weakly pyritic, usually freshwater, coals typical of the Rocky Mountain coalfields of British Columbia and the Gondwana coalfields of the southern hemisphere.     

A general in situ hydrothermal rolling-up formation of one-dimensional, single-crystalline lead telluride nanostructures

In this study we demonstrate that one-dimensional (1D) nanostructured lead telluride (PbTe) can be synthesized in a hydrothermal reaction between lead foil and tellurium powder. The resulting materials were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The formation of the 1D structure can be explained by an in situ hydrothermal rolling-up mechanism whereby PbTe is formed hydrothermally and deposited on the lead substrate. The lead underneath the PbTe layer is then selectively etched by a cetyltrimethylammonium bromide solution, thus allowing the PbTe to roll up into 1D structures. This method can be extended to prepare other 1D tellurides, including CdTe, Cu(2)Te, and Ag(2)Te.     

Study of segmented ethylene terephthalate–caprolactone copolymer by differential refractometry and light scattering

A segmented ethylene terephthalate (ET)–caprolactone (CL) copolymer was characterized by light scattering in chloroform tetrahydrofuran and butanone. The flexibility of the copolymer chain is comparable with that of typical flexible chains, such as polystyrene. In the process of applying the Bushuk–Benoit light scattering theory to the segmented PET–PCL copolymer, we encountered not only the problem of finding three solvents with different refractive index but also the problem of determining the specific refractive index increments for the PET and PCL segments in the copolymer, i.e., ν_PET and ν_PCL . In principle, the approximate values of ν_PET and ν_PCL can be obtained from the PET and PCL homopolymers, respectively. In reality, it involves many practical problems, e.g., to find three solvents not only for copolymer but also for the PET and PCL homopolymers. In this study, a different method was used to find both ν_PET and ν_PCL , wherein the ν values of at least two segmented PET–PCL copolymers with different PET compositions were used. With ν_PET , ν_PCL , and ν, we characterized the absolute molecular weight. Further, we show that the composition of an unknown segmented PET–PCL copolymer can be estimated from ν_PET , ν_PCL , and ν. © 1994 John Wiley & Sons, Inc.     

Effects of post-deposition annealing on the electrical propertiesand reliability of ultrathin chemical vapor deposited Ta2O5 films

This paper reports the effects of post-deposition rapid thermal annealing on the electrical characteristics of chemical vapor deposited (CVD) Ta₂O₅ (~10 nm) on NH₃-nitrided polycrystalline silicon (poly-Si) storage electrodes for stacked DRAM applications. Three different post-deposition annealing conditions are compared: a) 800°C rapid thermal O₂ annealing (RTO) for 20 sec followed by rapid thermal N₂ annealing (RTA) for 40 sec, b) 800°C RTO for 60 sec and c) 900°C RTO for 60 see. Results show that an increase in RTO temperature and time decreases leakage current at the cost of capacitance. However, over-reoxidation induces thicker oxynitride formation at the Ta₂O₅/poly-Si interface, resulting in the worst time-dependent dielectric breakdown (TDDB) characteristics     

Fuzzy learning control for a flexible-link robot

There are two main drawbacks in fuzzy control: 1) the design of fuzzy controllers is usually performed in an ad hoc manner where it is often difficult to choose some of the controller parameters; and 2) the fuzzy controller constructed for the nominal plant may later perform inadequately if significant and unpredictable plant parameter variations occur. In this paper we illustrate these two problems on a two-link flexible robot testbed by: 1) developing, implementing, and evaluating a fuzzy controller for the robotic mechanism, and 2) illustrating that payload variations can have negative effects on the performance of a well designed fuzzy control system. Next, we show how to develop and implement a fuzzy model reference learning controller for the flexible robot and illustrate that it can automatically synthesize a rule-base for a fuzzy controller that will achieve comparable performance to the case where it was manually constructed, and automatically tune the fuzzy controller so that it can adapt to variations in the payload     

An Efficient Triple-Tandem Polymer Solar Cell

We present an efficient triple-tandem polymer solar cell with identical poly(3-hexylthiophene) (P3HT) and 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6, 6)C₆₁ (PCBM) bulk heterojunction as the active layers and highly transparent Al (1 nm)/ MoO₃ (15 nm) as the intermediate layer. This intermediate layer is structurally smooth as characterized by atomic force microscopy. Although identical organic active layers are used to construct such triple-tandem cell, a tripled open-circuit voltage of 1.73 V and power conversion efficiency of 2.03% are obtained under simulated solar irradiation of 100 mW/cm² (AM1.5), demonstrating a viable technique for fabricating triple-tandem polymer cell with the intermediate layer of Al/MoO₃.     

Hole mobilities of thermally polymerized triaryldiamine derivatives and their application as hole-transport materials in organic light-emitting diodes (OLEDs)

This paper describes the synthesis of three triaryldiamine derivatives presenting two thermally polymerizable trifluorovinyl ether groups that can be polymerized through thermal curing to form perfluorocyclobutyl (PFCB) polymers. These PFCB polymers, studied using time-of-flight techniques for the first time, exhibited remarkable non-dispersive hole-transport properties, with values of μ_h of ca. 10^?4 cm² V^?1 s^?1. When we employed these thermally polymerized polymers as hole-transport layers (HTLs) in electroluminescence devices containing tris(8-hydroxyquinolate) aluminum (Alq₃) as the emission layer, we obtained high current densities (ca. 3400 mA cm^?2), impressive brightnesses (5 × 10⁴ cd m^?2), and high external quantum efficiencies (EQEs = 1.43%). These devices exhibited the same turn-on voltage, but higher EQEs, relative to those incorporating the vacuum-processed model compound N,N′-di(1-naphthyl)-N,N′-diphenylbenzidine (α-NPD) (EQE = 1.37%) as the HTL under the same device structure.     

Ge-Rich (70%) SiGe Nanowire MOSFET Fabricated Using Pattern-Dependent Ge-Condensation Technique

A top-down approach of forming SiGe-nanowire (SGNW) MOSFET, with Ge concentration modulated along the source/drain (Si_0.7Ge_0.3) to channel (Si_0.3Ge_0.7) regions, is presented. Fabricated by utilizing a pattern-size-dependent Ge-condensation technique, the SGNW heterostructure PMOS device exhibits 4.5times enhancement in the drive current and transconductance (G_m) as compared to the homojunction planar device (Si_0.7Ge_0.3). This large enhancement can be attributed to several factors including Omega-gated nanowire structure, enhanced hole injection efficiency (due to valence band offset), and improved hole mobility (due to compressive strain and Ge enrichment in the nanowire channel).     

Evanescent-Coupled Ge p-i-n Photodetectors on Si-Waveguide With SEG-Ge and Comparative Study of Lateral and Vertical p-i-n Configurations

Si-waveguide-integrated lateral Ge p-i-n photodetectors using novel Si/SiGe buffer and two-step Ge-process are demonstrated for the first time. Comparative analysis between lateral Ge p-i-n and vertical p-Si/i-Ge/n-Ge p-i-n is made. Light is evanescently coupled from Si waveguide to the overlaying Ge- detector, achieving high responsivity of 1.16 A/W at 1550 nm with f_{3 dB} bandwidth of 3.4 GHz for lateral Ge p-i-n detector at 5 V reverse bias. In contrast, vertical p-Si/i-Ge/n-Ge p-i-n has lower responsivity of 0.29 A/W but higher bandwidth of 5.5 GHz at -5 V bias. The higher responsivity of lateral p-i-n detectors is attributed to smaller optical mode overlap with highly doped Ge region as in vertical p-i-n configuration.