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101.
102.
KeeLoq is a lightweight block cipher with a 32-bit block size and a 64-bit key. Despite its short key size, it is used in remote keyless entry systems and other wireless authentication applications. For example, there are indications that authentication protocols based on KeeLoq are used, or were used by various car manufacturers in anti-theft mechanisms. This paper presents a practical key recovery attack against KeeLoq that requires 216 known plaintexts and has a time complexity of 244.5 KeeLoq encryptions. It is based on the principle of slide attacks and a novel approach to meet-in-the-middle attacks.  相似文献   
103.
Substrate noise is a major obstacle for mixed-signal integration. Ground bounce is a major contributor to substrate noise generation due to the resonance caused by the inductance and the Vdd-Vss admittance that consists of the on-chip digital circuit capacitance of the MOS transistors, the decoupling, and the parasitics arising from the interconnect. In this paper, we address: 1) the dependence of the Vdd-Vss admittance on the different states of the circuit, the supply voltage, and the interconnect, and 2) the computation of the total supply current with ground bounce. By using a fast and accurate macromodeling approach, the Vdd-Vss admittances of several test circuits are computed with 2%-3% error relative to the values simulated from the complete SPICE level netlist, but several orders of magnitude faster in CPU time and with 10% maximum error relative to the measurements on a test ASIC fabricated in a 0.18-/spl mu/m CMOS process on a high-ohmic substrate with 18 /spl Omega//spl middot/cm resistivity. The measurements also show that this admittance mainly depends only on the connectivity of the gates to the supply rail rather than their connectivity among each other.  相似文献   
104.
Abstract— This paper describes the architecture for a color picture tube (CPT), which enables a cost‐effective expansion of the color gamut. Besides a gamut expansion based on application of more‐saturated phosphors in the present three‐primary system, four‐ and five‐primary systems are described. Gun‐pitch modulation allows the application of a conventional electron gun for both a four‐ and five‐primary CRT. In these systems, the mask and matrix transmissions need to be reduced to maintain color purity. From this point of view, a five‐primary CRT is unrealistic. Two four‐primary CRTs are evaluated in more detail. But, here, the total anode current to generate white has to be increased substantially because of the reduced mask and matrix transmissions. Nonetheless, in this paper it is argued that with one of the four‐primary CRTs more‐saturated yellow colors can be displayed at 85% of the display luminance of a conventional system without loss of perceived sharpness.  相似文献   
105.
Two ultrafine, undoped ZrO2 powders with median primary particle sizes of 9 and 25 nm were used to prepare ceramic suspensions for thermoplastic extrusion. The organic vehicle consisted of an industrial-grade poly(ethylene- co -vinyl acetate) (EVA) or polyethylene (PE-HD) and decanoic acid as a dispersing agent. The powder volume loadings achieved were 44% and 52% by volume for the two powders, respectively. The amount of dispersant needed was calculated from a new model based on available chemisorption sites on the powder surface. Mixing and extrusion were conducted using a conventional modular plastic processing unit. Green bodies were dewaxed up to 450°C in an inert atmosphere and sintered to full density in air at 1060° and 1100°C, respectively. Analysis of the ceramic phase content and the microstructure of the bodies is presented.  相似文献   
106.

Background  

Child and infant malnourishment is a significant and growing problem in the developing world. Malnourished children are at high risk for negative health outcomes over their lifespans. Philani, a paraprofessional home visiting program, was developed to improve childhood nourishment. The objective of this study is to evaluate whether the Philani program can rehabilitate malnourished children in a timely manner.  相似文献   
107.
The purpose of this study was to analyze the diagnostic capacity of different classification criteria based on Body Mass Index in the assessment of nutritional status and to evaluate their effectiveness. The sample comprised 367 healthy pregnant adolescents in their first trimester of gestation, from a socioeconomic level IV, between Oct. 1999 and Dec. 2008. Two methodologies were applied for the nutritional classification: (1) Integral nutritional diagnosis (gold standard), and (2) Body Mass Index (BMI), using local reference values: Proyecto Venezuela and the Transversal Study of Caracas, and international reference values: Frisancho and WHO 2006. Concordances, kappa, sensitivity, specificity, positive and negative predictive values, positive and negative likelihood ratios, and the Youden index were calculated. According to the gold standard and BMI, the percentage of well-nourished pregnant women ranged between 62.4% and 80.6%. Within the deficit range, Frisancho was the most effective with kappa: 0.80; sensitivity: 87.3%; specificity: 94.8%; positive likelihood ratio: 16.9, and negative likelihood ratio: 0.13; Youden index: 0.82. Within the excess range, Frisancho and the Transversal Study of Caracas were the most effective with Youden index: 0.86 and 0.83, respectively. These results revealed that Frisancho was the best criterion to diagnose malnutrition in deficit in pregnant women. All references have an adequate diagnostic capacity for the excess range, of which Frisancho and the Transversal Study of Caracas are the best. We recommend using such reference values to optimize the efficiency of the BMI indicator in diagnosing malnutrition in deficit and in excess in the first trimester of gestation in pregnant adolescents within populations with similar characteristics.  相似文献   
108.
Organic solvent nanofiltration (OSN) is gradually expanding from academic research to industrial implementation. The need for membranes with low and sharp molecular weight cutoffs that are able to operate under aggressive OSN conditions is increasing. However, the lack of comparable and uniform performance data frustrates the screening and membrane selection for processes. Here, a collaboration is presented between several academic and industrial partners analyzing the separation performance of 10 different membranes using three model process mixtures. Membrane materials range from classic polymeric and thin film composites (TFCs) to hybrid ceramic types. The model solutions were chosen to mimic cases relevant to today's industrial use: relatively low molar mass solutes (330–550 Da) in n-heptane, toluene, and anisole.  相似文献   
109.
The integrin αIIbβ3 is the most abundant integrin on platelets. Upon platelet activation, the integrin changes its conformation (inside-out signalling) and outside-in signalling takes place leading to platelet spreading, platelet aggregation and thrombus formation. Bloodsucking parasites such as mosquitoes, leeches and ticks express anticoagulant and antiplatelet proteins, which represent major sources of lead compounds for the development of useful therapeutic agents for the treatment of haemostatic disorders or cardiovascular diseases. In addition to hematophagous parasites, snakes also possess anticoagulant and antiplatelet proteins in their salivary glands. Two snake venom proteins have been developed into two antiplatelet drugs that are currently used in the clinic. The group of proteins discussed in this review are disintegrins, low molecular weight integrin-binding cysteine-rich proteins, found in snakes, ticks, leeches, worms and horseflies. Finally, we highlight various oral antagonists, which have been tested in clinical trials but were discontinued due to an increase in mortality. No new αIIbβ3 inhibitors are developed since the approval of current platelet antagonists, and structure-function analysis of exogenous disintegrins could help find platelet antagonists with fewer adverse side effects.  相似文献   
110.
Systemic blood stream infections are a major threat to human health and are dramatically increasing worldwide. Pseudomonas aeruginosa is a WHO-alerted multi-resistant pathogen of extreme importance as a cause of sepsis. Septicemia patients have significantly increased survival chances if sepsis is diagnosed in the early stages. Affinity materials can not only represent attractive tools for specific diagnostics of pathogens in the blood but can prospectively also serve as the technical foundation of therapeutic filtration devices. Based on the recently developed aptamers directed against P. aeruginosa, we here present aptamer-functionalized beads for specific binding of this pathogen in blood samples. These aptamer capture beads (ACBs) are manufactured by crosslinking bovine serum albumin (BSA) in an emulsion and subsequent functionalization with the amino-modified aptamers on the bead surface using the thiol- and amino-reactive bispecific crosslinker PEG4-SPDP. Specific and quantitative binding of P. aeruginosa as the dedicated target of the ACBs was demonstrated in serum and blood. These initial but promising results may open new routes for the development of ACBs as a platform technology for fast and reliable diagnosis of bloodstream infections and, in the long term, blood filtration techniques in the fight against sepsis.  相似文献   
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