Hierarchically Structured Magnetic Nanoconstructs with Enhanced Relaxivity and Cooperative Tumor Accumulation

Iron oxide nanoparticles are formidable multifunctional systems capable of contrast enhancement in magnetic resonance imaging, guidance under remote fields, heat generation, and biodegradation. Yet, this potential is underutilized in that each function manifests at different nanoparticle sizes. Here, sub‐micrometer discoidal magnetic nanoconstructs are realized by confining 5 nm ultra‐small super‐paramagnetic iron oxide nanoparticles (USPIOs) within two different mesoporous structures, made out of silicon and polymers. These nanoconstructs exhibit transversal relaxivities up to ≈10 times (r ₂ ≈ 835 mm ^?1 s^?1) higher than conventional USPIOs and, under external magnetic fields, collectively cooperate to amplify tumor accumulation. The boost in r ₂ relaxivity arises from the formation of mesoscopic USPIO clusters within the porous matrix, inducing a local reduction in water molecule mobility as demonstrated via molecular dynamics simulations. The cooperative accumulation under static magnetic field derives from the large amount of iron that can be loaded per nanoconstuct (up to ≈65 fg) and the consequential generation of significant inter‐particle magnetic dipole interactions. In tumor bearing mice, the silicon‐based nanoconstructs provide MRI contrast enhancement at much smaller doses of iron (≈0.5 mg of Fe kg^?1 animal) as compared to current practice.     

可编程芯片：拼合成一个模拟解决方案

可配置模拟IC已经出现了多年,表面看来对市场的影响不及其数字同胞FPGA（现场可编程门阵列）。不过,当前的经济形势却使可编程模拟标准产品的概念突然显现出吸引力。一些需求能很好地适合这些器件的优点：保持在某个产品领域的设计前沿,不花费很多的设计成本,并且不存在会影响任何一个设计进入量产的最终用户需求。这样的日子可能为时不远了。     

Antimicrobial Gallium‐Doped Phosphate‐Based Glasses

Novel quaternary gallium‐doped phosphate‐based glasses (1, 3, and 5 mol % Ga₂O₃) were synthesized using a conventional melt quenching technique. The bactericidal activities of the glasses were tested against both Gram‐negative (Escherichia coli and Pseudomonas aeruginosa) and Gram‐positive (Staphylococcus aureus, methicillin‐resistant Staphylococcus aureus, and Clostridium difficile) bacteria. Results of the solubility and ion release studies showed that these glass systems are unique for controlled delivery of Ga³⁺. ⁷¹Ga NMR measurements showed that the gallium is mostly octahedrally coordinated by oxygen atoms, whilst FTIR spectroscopy provided evidence for the presence of a small proportion of tetrahedral gallium in the samples with the highest gallium content. FTIR and Raman spectra also afford an insight into the correlation between the structure and the observed dissolution behavior via an understanding of the atomic‐scale network bonding characteristics. The results confirmed that the net bactericidal effect was due to Ga³⁺, and a concentration as low as 1 mol % Ga₂O₃ was sufficient to mount a potent antibacterial effect. The dearth of new antibiotics in development makes Ga³⁺ a potentially promising new therapeutic agent for pathogenic bacteria including MRSA and C. difficile.     

A CMOS RF front-end for a multistandard WLAN receiver

This letter describes the design and performance of a dual band tri-mode receiver front-end compliant with the IEEE 802.11a, b, and g standards. The receiver front-end was built in a 0.18-/spl mu/m CMOS process and achieves a noise figure of 4.7 dB/5.1 dB for the 2.4-GHz/5-GHz bands, respectively. The receiver front-end provides a dual gain mode of 5 dB/30 dB with an IIP3 of -1dBm for the low gain mode. The front-end draws 25 mA/27 mA from a 1.8-V supply for the 2.4-GHz/5-GHz bands, respectively.     

基于数学建模要求下先进的提拉法控制系统研制

提出了在开发一种先进的直拉法晶体生长控制系统中占据重要地位的设备及工艺特征的下位机模型;分析所采集到的实验数据,揭示出控制中的重要问题,由此开发了一种新的控制结构;该模型是建立在常规控制结构和提出新的控制结构性能对比的基础上。     

An improved minimizing algorithm for sum of disjoint products[reliability theory]

The Abraham-Locks-revised (ALR) sum-of-disjoint products (SDP) algorithm is an efficient method for obtaining a system reliability formula. The author describes a minor modification of the ALR algorithm called the Abraham-Locks-Wilson (ALW) method. The new feature is an alternative method of ordering paths and terms. ALW obtains a shorter disjoint system formula on a test example than any previous SDP method and allows small computational savings in processing large paths of complex networks. As there are different ways to obtain a reliability formula it is useful to use an approach which yields the smallest formula relative to computational effort expended. The extra effort in ordering the terms should be reasonably small and usually leads to improved efficiency in the later stages of the algorithm. ALW allows the analyst to operate in a more efficient way on many problems, particularly if the overlap ordering is used in the early stages of processing but is probably ignored for terms that contain a majority of the Boolean variables     

A correlation-based approach to calculate rotation and translation of moving cells.

We present a noniterative image cross-correlation approach to track translation and rotation of crawling cells in time-lapse video microscopy sequences. The method does not rely on extracting features or moments, and therefore does not impose specific requirements on the type of microscopy used for imaging. Here we use phase-contrast images. We calculate cell rotation and translation from one image to the next in two stages. First, rotation is calculated by cross correlating the images' polar-transformed magnitude spectra (Fourier magnitudes). Rotation of the cell about any center in the original images results in translation in this representation. Then, we rotate the first image such that the cell has the same orientation in both images, and cross correlate this image with the second image to calculate translation. By calculating the rotation and translation over each interval in the movie, and thereby tracking the cell's position and orientation in each image, we can then map from the stationary reference frame in which the cell was observed to the cell's moving coordinate system. We describe our modifications enabling application to nonidentical images from video sequences of moving cells, and compare this method's performance with that of a feature extraction method and an iterative optimization method.     

Mean on the Screen: Social Aggression in Programs Popular With Children

A content analysis was conducted to examine the portrayal of social aggression in the 50 most popular television programs among 2‐ to 11‐year‐old children. Results revealed that 92% of the programs in the sample contained some social aggression. On average, there were 14 different incidents of social aggression per hour in these shows, or one every 4 minutes. Compared to the portrayals of physical aggression, social aggression was more likely to be enacted by an attractive perpetrator, to be featured in a humorous context, and neither rewarded or punished. In these ways, social aggression on television poses more of a risk for imitation and learning than do portrayals of physical aggression. Findings are discussed in terms of social cognitive theory.     

今天的EDA向何处去？

这就是正在没落的电子设计自动化业的现状吗？上月初,每年一次的设计自动化研讨会开幕,据说到场人数低于预期。有些供应商（最著名的是Cadence Design Systems）缺席展会,很多其它厂商的展位也缩水。已有人在议论EDA必须有所变化。本文发表时,Cadence已宣布了对Mentro Graphics的主动出价,而Mentor也迅速加以拒绝,理由是出价过低,以及不可能获得监管批准等。现在有一种论调是EDA业三巨头（Candence、Mentor和Synopsys）的合并,它表示着市场的最终老化。