65nm半导体工艺发展策略

本文研究Altera在65nm工艺上的工程策略,介绍公司如何为客户降低生产和计划风险,并同时从根本上提高密度、性能,及降低成本和功耗.     

Update on optimized purification and characterization of natural milk allergens

Highly purified allergens namely cow's milk alpha-lactalbumin (ALA). (Bos d 4), beta-lactoglobulin (BLG) (Bos d 5) and casein (Bos d 8) and goat's milk casein were prepared from the raw milk from a single animal with a known genetic background. Consequently the natural isoforms are limited, constant and characterized. Purification included selective precipitations and chromatographical steps. Characterization of structure and allergenic activity assessment of milk allergens were carried out using physicochemical and immunochemical methods. Taken together data demonstrated the absence of impurities and of contamination by other milk allergens in each preparation. NMR and circular dichroism analyses confirmed the native conformation and proper folding of ALA and BLG and the expected absence of folding of bovine and caprine casein. Enzyme immuno assays confirmed the native conformation of BLG and the purity and immunoreactivity of all the proteins. The allergenic activity, e. g. the IgE binding capacity, of purified proteins was identical as that of those proteins when present in milk. The purified proteins also demonstrated the ability to provoke the degranulation of humanized rat basophilic leukaemia cells. All the data thus confirm the purity, identity, structural conformation and functionality of the prepared milk allergens.     

Computation offloading balance in small cell networks with mobile edge computing

Wireless Networks - As a promising way to offset the low computation capacity of user equipments (UEs), mobile edge computing (MEC) has attracted great attention of academy and industrial recently....     

Subdiaphragmatic and intrathoracic paraspinal malignant peripheral nerve sheath tumors: a clinicopathologic study of 25 patients and 26 tumors

BACKGROUND: To determine the effects of anatomic site on the presentation and diagnosis of malignant peripheral nerve sheath tumors (MPNSTs) and on the treatment and outcomes of the patients, the authors initiated a study of these tumors at different sites. An earlier report described MPNSTs of the buttock and lower extremity, and the current series analyzes those presenting at intrathoracic (IT) and subdiaphragmatic (SD) paraspinal sites. METHODS: The authors reviewed data on patients with paraspinal MPNSTs who were seen at Memorial Hospital during the period 1960-1995 and for whom histologic slides were available. Various clinicopathologic parameters and their effects on patient outcomes were examined. RESULTS: Twenty-five patients with 26 tumors were evaluated. Seven tumors were IT and 19 were SD; 60% of the patients had neurofibromatosis type 1 (NF1). Most patients presented with pain, and a diagnostic delay (of 3 months to 2 years) was often noted. Mean tumor sizes for SD and IT tumors were 14.3 cm and 6.6 cm, respectively. Most MPNSTs were composed of spindle cells in fascicles. Twenty-seven percent exhibited divergent differentiation. Twenty-four tumors were high grade, and a low grade component was identified in 8 tumors. Surgical resection was attempted for 23 tumors (88%), but complete resection was achieved in only 6 cases (23%). Eighty percent of the patients died of their tumors, 2-year and 5-year survival rates were 35% and 16%, and median survival was 8.5 months. Significant prognostic factors were tumor size <5 cm, the presence of a low grade component, and complete tumor resection. CONCLUSIONS: Paraspinal MPNSTs have more aggressive behavior than peripherally located tumors, mainly because of the difficulty encountered in resecting them completely. Prognoses of patients with MPNST at this site appear to be affected by resection status, tumor size, and tumor grade.     

Global annealing genetic algorithm and its convergence analysis

A new selection mechanism termed global annealing selection (GAnS) is proposed for the genetic algorithm. It is proved that the GAnS genetic algorithm converges to the global optimums if and only if the parents are allowed to compete for reproduction, and that the variance of population's fitness can be used as a natural stopping criterion. Numerical simulations show that the new algorithm has stronger ability to escape from local maximum and converges more rapidly than canonical genetic algorithm.     

Nucleating agent effects on selected properties of polypropylene

A study of nucleating agent effects on the selected optical and mechanical properties of a semicrystalline homoisotactic polypropylene is presented. The results showed that the type and concentration of the nucleating agents to be added, and the screw speed during the compounding process, were of vital importance. It was also noticed that the improvement in optical clarity due to the addition of the additive might not necessarily benefit the mechanical properties of injection molded articles.     

Linear or branched structure? Probing molecular architectures of fullerene-styrene copolymers by size exclusion chromatographs with online right-angle laser-light scattering and differential viscometric detectors

The poly(C₆₀-co-styrene)s prepared by radical copolymerizations of C₆₀ and styrene in bulk were characterized by multiple-detector size-exclusion chromatographs consisting of a refractometer, a differential viscometer, and/or a right-angle laser-light scattering photometer. The multidetector systems enabled the determinations of reliable, absolute molecular weights of the copolymers. The plots of intrinsic viscosity vs. molecular weight and radius of gyration vs. molecular weight offered valuable information about the molecular architectures of the copolymers. The slopes of the plots reveal that the structure of the copolymer changes with its C₆₀ content: the copolymer with a low C₆₀ content of 0.58 wt% possesses a linear structure, whereas its conger with a high C₆₀ content of 1.14 wt% possesses a branched structure.     

Phospholipids and oxophospholipids in atherosclerotic plaques at different stages of plaque development

We identified and quantified the hydroperoxides, hydroxides, epoxides, isoprostanes, and core aldehydes of the major phospholipids as the main components of the oxophospholipids (a total of 5–25 pmol/μmol phosphatidylcholine) in a comparative study of human atheroma from selected stages of lesion development. The developmental stages examined included fatty streak, fibrous plaque, necrotic core, and calcified tissue. The lipid analyses were performed by normal-phase HPLC with on-line electrospray MS using conventional total lipid extracts. There was great variability in the proportions of the various oxidation products and a lack of a general trend. Specifically, the early oxidation products (hydroperoxides and epoxides) of the glycerophosphocholines were found at the advanced stages of the plaques in nearly the same relative abundance as the more advanced oxidation products (core aldehydes and acids). The anticipated linear accumulation of the more stable oxidation products with progressive development of the atherosclerotic plaque was not apparent. It is therefore suggested that lipid infiltration and/or local peroxidation is a continuous process characterized by the formation and destruction of both early and advanced products of lipid oxidation at all times. The process of lipid deposition appears to have been subject to both enzymatic and chemical modification of the normal tissue lipids. Clearly, the appearance of new and disproportionate old lipid species excludes randomness in any accumulation of oxidized LDL lipids in atheroma.     

Molecular dynamics simulation of liquid crystal formation within semi-flexible main chain LCPs

Molecular dynamics simulations of a semi-flexible main chain LCP (liquid crystalline polymer) have been carried out using a newly developed model named solo-LJ-spring-GB model. The new model represents the molecular chain in the form of GB-spring-LJ-spring-…-LJ-spring-GB sections that simplifies the model and reduces the simulation computation by many times. The new model was evaluated by studying the phase behaviors of semi-flexible main chain LCPs through simulation. The results, such as the spontaneous phase transition from isotropic phase to nematic phase as the system temperature decreases and the odd-even effect of the number of flexible spacers on its thermodynamic properties agree well with other experimental results as well as simulations using the traditional GB/LJ model. The orientational and translational mobilities of mesogenic units in the new model have also been measured and compared with those in the traditional GB/LJ model with very little differences found.