采用可高效再配置DSP系统的动态加载技术

新的移动通信市场为DSP技术带来了一系列新的挑战。我们可采用动态加载技术来有效解决这些难题。     

Rat parvovirus type 1: the prototype for a new rodent parvovirus serogroup

A newly recognized parvovirus of laboratory rats, designated rat parvovirus type 1a (RPV-1a), was found to be antigenically distinct. It was cloned, sequenced, and compared with the University of Massachusetts strain of rat virus (RV-UMass) and other autonomous parvoviruses. RPV-1a VP1 identity with these viruses never exceeded 69%, thus explaining its antigenic divergence. In addition, RPV-1a had reduced amino acid identity in NS coding regions (82%), reflecting phylogenetic divergence from other rodent parvoviruses. RPV-1a infection in rats had a predilection for endothelium and lymphoid tissues as previously reported for RV. Infectious RPV-1a was isolated 3 weeks after inoculation of infant rats, suggesting that it, like RV, may result in persistent infection. In contrast to RV, RPV-1a was enterotropic, a characteristic previously associated with parvovirus infections of mice rather than rats. RPV-1a also differed from RV in that infection was nonpathogenic for infant rats under conditions where RV infection causes high morbidity and mortality. Thus, RPV-1a is the prototype virus of an antigenically, genetically, and biologically distinct rodent parvovirus serogroup.     

A novel DNA-peptide complex for efficient gene transfer and expression in mammalian cells

To develop a nonviral gene delivery system for treatment of diseases, our strategy is to construct DNA complexes with short synthetic peptides that mimic the functions of viral proteins. We have designed and synthesized two peptides which emulate viral functions - a DNA condensing agent, YKAK(8)WK, and an amphipathic, pH-dependent endosomal releasing agent, GLFEALLELLESLWELLLEA. The active gene delivery complex was constructed step-wise through a spontaneous self-assembly process involving oppositely charged, electrostatic interactions. To assemble DNA-peptide complexes with different overall net charges, only the negative charges of DNA phosphate, the positive charges of the 10 epsilon-amino groups of YKAK(8)WK and the negative charges of the 5 gamma-carboxyl groups of GLFEALLELLESLWELLLEA were considered. In the first step, negatively charged DNA was rapidly-mixed with an excess of YKAK(8)WK to form positively charged DNA-YKAK(8)WK complexes, which gave little gene transfer. In the second step and to form the active complex,the cationic DNA complex was rapidly mixed with spontaneously incorporated through electrostatic interactions. Transfection using these complexes of CMV-luc, YKAK(8)WK and GLFEALLELLESLWELLLEA gave high-levels of gene expression in a variety of cell lines. These simple DNA complexes, which contain only three molecularly defined components, have general utility for gene delivery and can replace viral vectors and cationic lipids for some applications in gene therapy.     

Understanding the preferential oxidation of carbon monoxide (PrOx) using size‐controlled Au nanocrystal catalyst

Removing CO from hydrogen streams is an important industrial process. The catalytic preferential oxidation of CO (PrOx) is a promising method for CO removal, leaving the hydrogen concentration unchanged. Here, the effect of size and support on the gold‐catalyzed PrOx reaction using size‐controlled Au nanocrystals (NCs) is investigated. For all supports, Au NC sizes of 2–5 nm show the highest rates, whereas for larger sizes rates drop. Ceria‐supported Au shows by far the best performance. By analyzing the dependency of the reaction rate on the NC diameter, the most active centers for CO oxidation on Au/CeO₂ are Au⁺ corner atoms at the interface with the support, resulting in 2.1 nm Au NCs supported on ceria reaching full O₂ conversion and CO selectivity of about 50%. Therefore, it is suggested that increasing the fraction of Au‐ceria interface sites would lead to the best performing materials for this reaction. © 2018 American Institute of Chemical Engineers AIChE J, 64: 3159–3167, 2018     

Micro solar energy harvesting using thin film selective absorber coating and thermoelectric generators

The use of a nanometer-scale solar selective absorber coating to enhance the performance of a thermoelectric generation (TEG) module in solar thermal energy harvesting is presented. The thin film coating is fabricated by electrochemical deposition of a bimetallic layer of tin and nickel on copper substrate. The coating has a dendrite structure with grain size of 100 nm. Testing indicates the ability of these collectors to transform incident radiation into thermal energy. The collectors utilizing the selective coating achieved a final temperature 10 °C higher than the baseline copper device. More importantly, the coating demonstrates the ability to collect and transmit over 90 % of the available heat flux. The harvested thermal energy is applied to drive a TEG module for useful power generation. The device utilized with selective absorber coating shows an output power 4.5 times more than the baseline device. Overall area of the collector plate is 16 cm².     

A Process for the Aqueous Enzymatic Extraction of Corn Oil from Dry Milled Corn Germ and Enzymatic Wet Milled Corn Germ (E-Germ)

A bench-scale aqueous enzymatic method was developed to extract corn oil from corn germ from either a commercial corn dry mill or corn germ from a newly-developed experimental enzymatic wet milling process (E-Germ). With both types of germs, no oil was extracted when acidic cellulase was the only enzyme used. Pre-treating dry milled corn germ by heating it in boiling water or microwave pretreatment, followed by enzymatic extraction with the acidic cellulase resulted in oil yields of about 43% and 57%, respectively. A two-step process, combining both acidic cellulase and alkaline protease treatments, with no heat pretreatment, achieved oil yields of 50–65% from dry milled corn germ and 80–90% from E-Germ. Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture.     

Open Pluggable Edge Services: An Architecture for Networked Content Services

The IETF's open pluggable edge services (OPES) working group focuses on rule-based, in-line transformation services of data flows between two Internet endpoints, such as Web servers and Web clients. The group has developed an architectural framework to authorize, invoke, and trace such application-level services. The framework follows a one-party consent model, which requires that at least one of the application-layer endpoints explicitly authorize each service. OPES services must also be reversible by request of the application endpoints     

The Effect of Cobalt on the Degradation of Methyl β-D-Gluco-Pyranoside by Oxygen in Aqueous Sodium Hydroxide Solution

Abstract

The effect of Co(II) (0 to 0.25 mW CoSO₄) on the degradation of methyl β-D-glucopyranoside (MBG) at 120°C in 1.25M NaOH with 0.68 MPa oxygen pressure was studied. When the Co(II) was increased from 0.00 to 0.01 to 0.05 mM the MBG half-life decreased from 12 to 6 to 1.5 hours, reflecting approximately a 0.5 order kinetic dependence on cobalt. An oxidation-reduction cycle between Co(II) and Co(III) involving oxidation of Co(II) by oxygen and oxidation of the glucoside by Co(III), hydroxyl radical, or superoxide is proposed for the degradation. At the 0.25 mM Co(II) addition level highly adsorptive Co(OH)₂ formed prior to reaction initiation with oxygen and removed otherwise soluble cobalt from solution. This resulted in lower rates of MBG degradation than obtained even at 0.01 mM Co(II) addition. However, Co(II) solubility could be enhanced if silicate anions or polyols (including MBG) were added to the alklaine medium prior to the Co(II) addition. In reactions initially containing 0.25 mM soluble Co(II), an adsorptive precipitate, presumably CoO(OH), gradually formed after reaction initiation with oxygen. Precipitation of the Co(III) solid coincided with a rapid decline in the rate of MBG degradation. Cobalt had little effect on the products of MBG degradation.