A novel InP/InGaAs tunneling emitter bipolar transistor (TEBT) is fabricated and demonstrated. The studied device exhibits a very small collector-emitter offset voltage of 40 mV and an extremely wide operation regime. The operation region is larger than 11 decades in magnitude of collector current (10/sup -12/ to 10/sup -1/A). A current gain of 3 is obtained even if the device is operated at an ultralow collector current of 3.9 /spl times/ 10/sup -12/A (1.56 /spl times/ 10/sup -7/A/cm/sup 2/). Furthermore, the common-emitter breakdown voltage of the studied device is higher than 2 V. Consequently, the studied device shows a promise for low supply voltage, and low-power consumption circuit applications. 相似文献
Based on Lee-Lu-Lee's array multipliers and the RESO method, a concurrent error detection scheme in array multipliers for GF(2m ) fields is presented and only one clock cycle is added. The fault tolerant capability in such array multipliers is also included and only two extra clock cycles are required 相似文献
Amplification or overexpression of HER-2/neu in human lung cancer has been correlated with poor prognosis and chemoresistance. We have previously reported that the adenovirus type 5 early region 1A (E1A) gene product can suppress HER-2/neu-mediated transformation phenotypes through inhibition of HER-2/neu expression. To find an efficient way to treat HER-2/neu-overexpressing lung cancer with E1A, a replication-deficient adenovirus containing the E1A gene, Ad.E1A(+), was used to transduce E1A into HER-2/neu-overexpressing and low expressing human lung cancer cell lines. Tumour cell growth in vitro and colony formation in soft agarose were greatly inhibited by Ad.E1A(+) transduction in HER-2/neu-overexpressing lung cancer cell lines. In HER-2/neu low expressing cell lines, E1A could not inhibit cell growth in vitro but could reduce the colony formation ability in soft agarose, indicating different effects of E1A in these two types of cancer cells. To test the therapeutic efficacy of E1A to lung cancer by systemic delivery in vivo, tumor-bearing mice were established by intratracheal injection of lung cancer cells and treated by i.v. tail injections of Ad.E1A(+). As a result, Ad.E1A(+) suppressed HER-2/neu overexpression and inhibited intratracheal lung cancer growth. However, no significant tumor suppression effect of Ad.E1A(+) was observed in mice bearing HER-2/neu low expressing cell line when the same therapeutic procedure was followed. Thus, we conclude that systemic delivery of Ad.E1A(+) can efficiently achieve therapeutic effect in HER-2/neu-overexpressing lung cancer in vivo. 相似文献
Polycylic aromatic hydrocarbons (PAHs) are listed as carcinogenic and mutagenic priority pollutants, belonging to the environmental endocrine disrupters. Most PAHs in the environment stem from the atmospheric deposition and diesel emission. Consequently, the elimination of PAHs in the off-gases is one of the priority and emerging challenges. Catalytic oxidation has been widely used in the destruction of organic compounds due to its high efficiency (or conversion of reactants), its economic benefits and good applicability.
This study investigates the application of the catalytic oxidation using Pt/γ-Al2O3 catalysts to decompose PAHs and taking naphthalene (the simplest and least toxic PAH) as a target compound. It studies the relationships between conversion, operating parameters and relevant factors such as treatment temperatures, catalyst sizes and space velocities. Also, a related reaction kinetic expression is proposed to provide a simplified expression of the relevant kinetic parameters.
The results indicate that the Pt/γ-Al2O3 catalyst used accelerates the reaction rate of the decomposition of naphthalene and decreases the reaction temperature. A high conversion (over 95%) can be achieved at a moderate reaction temperature of 480 K and space velocity below 35,000 h−1. Non-catalytic (thermal) oxidation achieves the same conversion at a temperature beyond 1000 K. The results also indicate that Rideal–Eley mechanism and Arrhenius equation can be reasonably applied to describe the data by using the pseudo-first-order reaction kinetic equation with activation energy of 149.97 kJ/mol and frequency factor equal to 3.26 × 1017 s−1. 相似文献
Neurological complications of radiotherapy and chemotherapy can affect the central or peripheral nervous system. Most are dose-dependent and constitute a limiting factor in the administration of treatments. Radiation-induced neurological complications are classified as acute, early-delayed or delayed. The most important are radionecrosis and cognitive dysfunction/leukoencephalopathy. Neurotoxicity of chemotherapy is frequent and depends upon dose, type of drugs (especially cisplatin and methotrexate) and their combination with radiotherapy. 相似文献
As IC devices scale down to the submicron level, the resistance-capacitance (RC) time delays are the limitation to circuit
speed. A solution is to use low dielectric constant materials and low resistivity materials. In this work, the influence of
underlying barrier Ta on the electromigration (EM) of Cu on hydrogen silsesquioxane (HSQ) and SiO2 substrates was investigated. The presence of a Ta barrier not only improves the adhesion between Cu and dielectrics, but
also enhances the crystallinity of Cu film and improves the Cu electromigration resistance. The activation energy obtained
suggests a grain boundary migration mechanism and the current exponent calculated indicates the Joule heating effect. 相似文献
A Montgomery's algorithm in GF(2m) based on the Hankel matrix-vector representation is proposed. The hardware architecture obtained from this algorithm indicates low-complexity bit-parallel systolic multipliers with irreducible trinomials. The results reveal that the proposed multiplier saves approximately 36% of space complexity as compared to an existing systolic Montgomery multiplier for trinomials. A scalable and systolic Montgomery multiplier is also developed by applying the block-Hankel matrix-vector representation. The proposed scalable systolic architecture is demonstrated to have significantly less time-area product complexity than existing digit-serial systolic architectures. Furthermore, the proposed architectures have regularity, modularity and local interconnectability, making the.m highly appropriate for VLSI implementation. 相似文献
Today, with the increasing popularity of multicore processors, one approach to optimizing the processor's performance is to reduce the execution times of individual applications running on each core by designing and implementing more powerful cores. Another approach, which is the polar opposite of the first, optimizes the processor's performance by running a larger number of applications on a correspondingly larger number of cores, albeit simpler ones. The difference between these two approaches is that the former focuses on reducing the latency of individual applications or threads (it optimizes the processor's single-threaded performance), whereas the latter focuses on reducing the latency of the applications' threads taken as a group (it optimizes the processor's multithreaded performance). The panel, from the 2007 Workshop on Computer Architecture Research Directions, discusses the relevant issues. 相似文献
The present study shows that extracellular adenosine triphosphate (ATP) has the capacity to mediate dose-dependent lysis of the monocytic leukemia cell line THP-1. The lysis, assessed by 51Cr release, was found to be selective for ATP, because adenosine diphosphate (ADP) or other nucleotides were less effective in their ability to lyse the cells. The amount of 51Cr released was particularly enhanced by the stimulation of the cells with 1,000 U/mL of interferon gamma (IFN-gamma) for 3 days, and the sensitivity was time and dose dependent. Analysis of the mechanism of lysis indicated that the fully ionized form, ATP4-, mediated the lysis, because the addition of cation chelators or the absence of the divalent cations, Ca2+ and Mg2+, in the culture medium of a 6-hour 51Cr release assay increased the percent specific lysis. Therefore, the ATP receptors on THP-1 cells were classified as P2Z purinoceptors. Moreover, it is shown here that the Ca2+/calmodulin complex plays a role in the regulation of the lysis by extracellular ATP of THP-1 cells, because antagonists of this complex, such as trifluoperazine or KN-62, were found to inhibit the ATP-mediated cell lysis. 相似文献