The EASI project-improving the effectiveness and quality ofimage-guided surgery

In recent years, advances in computer technology and a significant increase in the accuracy of medical imaging have made it possible to develop systems that can assist the clinician in diagnosis, planning, and treatment. This paper deals with an area that is generally referred to as computer-assisted surgery, image-directed surgery, or image-guided surgery. We report the research, development, and clinical validation performed since January 1996 in the European Applications in Surgical Interventions (EASI) project, which is funded by the European Commission in their “4th Framework Telematics Applications for Health” program. The goal of this project is the improvement of the effectiveness and quality of image-guided neurosurgery of the brain and image-guided vascular surgery of abdominal aortic aneurysms, while at the same time reducing patient risks and overall cost. We have developed advanced prototype systems for preoperative surgical planning and intraoperative surgical navigation, and we have extensively clinically validated these systems. The prototype systems and the clinical validation results are described in this paper     

Properties and some fast algorithms of the Haar transform in image processing and pattern recognition

Properties of the Haar transform in image processing and pattern recognition are investigated. A lower bound of the performance of the Haar transform relative to that of the Karhunen-Loeve transform for first-order Markov processes is found. It is proved that the Haar transform is inferior to the Walsh-Hadamard transform for such processes. A unique condition is presented which, if satisfied by the elements of a matrix, will make the Karhunen-Loeve transform of the matrix and the Haar transform equivalent. Some fast algorithms are given to realize the diagonal elements of a Haar transformed matrix.     

Fabrication of citric acid crosslinked β‐cyclodextrin/hydroxyethylcellulose hydrogel films for controlled delivery of poorly soluble drugs

β‐cyclodextrin grafted hydroxyethylcellulose (βCD‐g‐HEC) hydrogel films were prepared for the controlled release of poorly soluble model drug (ketoconazole) using citric acid as crosslinking agent. The active βCD and carboxyl content of the hydrogel films were determined by phenolphthalein assay and acid–base titration. The films were characterized by solid state ¹³C NMR, ATR–FTIR, thermogravimetric analysis, and differential scanning calorimetric, and analyzed for tensile strength, swelling ratio, drug loading, release, hemocompatibility, in vitro cytotoxicity, and implantation test. An increase in the concentration of βCD in feed increased the active βCD content of the hydrogel films but reduced their extent of interpolymer crosslinking. The βCD‐g‐HEC hydrogel films with high active βCD content showed maximum drug loading whereas those with high crosslinking density were capable of controlling the drug release for long duration. Hemolysis assay and in vitro cytotoxicity study revealed the biocompatible nature of the hydrogel films whereas implantation test indicated their minimal inflammatory effect. From the overall results, βCD‐g‐HEC hydrogel films were found to be better alternative to the previously reported βCD‐HPMC and βCD‐CMC hydrogel films for enhanced loading and long‐term release, respectively, of the poorly soluble drugs. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46452.     

Study of thermally coupled distillation systems for energy-efficient distillation

Distillation is one of the most widely used separation unit operations in process industries, although it is quite energy intensive. In many cases, the enormous energy requirements for distillation make it economically infeasible to carry out the separation. Thermally coupled distillation system (TCDS) is an advanced distillation method that provides significant energy savings of about 30% as compared with conventional distillation column sequences. The most well-known TCDS sequence, the Petlyuk configuration, has some operational challenges due to bidirectional vapour flow, which makes its implementation difficult in two-column mode. To overcome these limitations, a number of unidirectional vapour flow configurations have been proposed in the literature. The work on simulation analysis for such configurations is limited. In this paper, simulation models for two such configurations are developed, analyzed and compared with the Petlyuk and conventional distillation column sequences for separation of equimolar mixture of benzene–toluene–ethylbenzene.     

In Situ Nanoparticle Embedding for Authentication of Epoxy Composites

In situ reduction of chloroauric acid inside an amine‐cured epoxy matrix leads to formation of gold nanoparticles which are embedded inside the part. This phenomenon is leveraged to design an authentication system for composites wherein the particles are embedded spatially and are invisible to the naked eye. Under UV light, the particles diffract light and create an easily visible path. The particles penetrate inside the part and create a permanent, cost‐effective, tamper‐proof code. The advantage of this technique is that this authentication system can be built in composite parts after fabrication of the composite structure. As very small amount (nanograms) of particles are present in the part, negligible change in the thermal characteristics of the parent matrix is observed. The particles can be embedded easily in carbon fiber as well as glass fiber reinforced epoxy structures.     

p型SiC欧姆接触理论及研究进展

碳化硅(SiC)具有宽禁带、高临界击穿电场、高热导率等优异特性,是制备高温、高频、大功率器件最理想的半导体材料之一。然而,制备良好的SiC欧姆接触尤其是p型SiC欧姆接触仍然是SiC器件研制中亟需攻克的关键技术难题。首先对p型SiC欧姆接触的形成机制及金属/SiC接触势垒理论进行了深入分析。然后,对近年来p型SiC欧姆接触的重要研究进展进行了综述,包括形成欧姆接触的金属体系,制备工艺条件,获得的比接触电阻率等,并重点讨论了p型SiC欧姆接触的形成机理。最后,对未来p型SiC欧姆接触的研究方向进行了展望。     

Gelatin–κ-carrageenan polyelectrolyte complex hydrogel compositions for the design and development of extended-release pellets

Present investigation was aimed to develop Zaltoprofen-loaded extended-release (ER) pellets formulation for prolonged release. The matrix type of pellets was prepared by extrusion-spheronization technique using calcium chloride-mediated gelatin–κ-carrageenan (G–κ-Carr) polyelectrolyte complex (PEC) hydrogel using rotatable central composite design. The pellets were characterized for physicochemical, morphological, solid-state characterization and flow properties. The formulations were also estimated for drug release and mucoadhesion potential. The optimized formulation (F1) containing 5:5 ratio of G–κ-Carr showed a drug release up to 98.2% and mucoadhesion of 95%. Optimized formulation showed acceptable release pattern, and hence would be viable alternative to ER type of formulations.     

Coefficient of friction reduction of ethylene‐co‐acrylic acid film: Effects of grafted 12‐aminododecanamide and solvent exposure

The effect of covalently bound 12‐aminododecanamide on the surface coefficient of friction (COF) of ethylene–acrylic acid copolymer (EAA) films was investigated. The reaction involved grafting 12‐aminododecanoic acid to the inherent carboxylic acid groups on the film, followed by amidation of the grafted amino acid. Conversion of film carboxylic acid groups to primary amide groups was also conducted to compare the impact of direct surface amidation. Subsequent measurements showed that both surface amidation schemes reduced the kinetic COF from 0.30 to 0.15 ～ 0.18. Repetitive COF testing revealed that amide‐modified EAA films maintained low COF values that were independent of the number of COF test runs. However, control experiments showed that COF values also depended greatly on simply exposing film to the various reaction solvents, which increased surface roughness. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2242–2248, 2005     

Flash heating in the diamond cell: melting curve of rhenium

A new method for measuring melting temperatures in the laser-heated diamond cell is described. This method circumvents previous problems associated with the sample instability, thermal runaway, and chemical reactions. Samples were heated with a single, 20 milliseconds rectangular pulse from a fiber laser, monitoring their thermal response with a fast photomultiplier while measuring the steady state temperature with a CCD spectrometer. The samples were recovered and analyzed using scanning electron microscopy. Focused ion beam milling allowed to examine both the lateral and the vertical solid-liquid boundaries. Ambient pressure tests reproducibly yielded the known melting temperatures of rhenium and molybdenum. Melting of Re was measured to 50 GPa, a 5-fold extension of previous data. The refractory character of Re is drastically enhanced by pressure, in contrast to Mo.     

Efficiency improvement opportunities for personal computer monitors: implications for market transformation programs

Displays account for a significant portion of electricity consumed in personal computer (PC) use, and global PC monitor shipments are expected to continue to increase. We assess the market trends in the energy efficiency of PC monitors that are likely to occur without any additional policy intervention and estimate that PC monitor efficiency will likely improve by over 40 % by 2015 with saving potential of 4.5 TWh per year in 2015, compared to today's technology. We discuss various energy-efficiency improvement options and evaluate the cost-effectiveness of three of them, at least one of which improves efficiency by at least 20 % cost effectively beyond the ongoing market trends. We assess the potential for further improving efficiency taking into account the recent development of universal serial bus-powered liquid crystal display monitors and find that the current technology available and deployed in them has the potential to deeply and cost effectively reduce energy consumption by as much as 50 %. We provide insights for policies and programs that can be used to accelerate the adoption of efficient technologies to further capture global energy saving potential from PC monitors which we estimate to be 9.2 TWh per year in 2015.