bluuebunny/crossref_metadata_2025 huggingface dataset:
Phase Field Simulation of the Pure Material Dendrite Growth in a Forced Flow
Authors: Liu Jing , Wang Ying Shuo
Published: September 2012

The phase field method is effective in simulating the formation of solidification microstructure. Based on the phase field models of coupling flow field and noise field proposed by Tong and Beckermann, using finite difference method to solve control equation, apartly simulating the dendritic morphology under the condition of convection or none convection, and drawing the following conclusions after comparing the results: in the side, the dendrite will no longer be symmetrical under the condition of countercurrent and downstream, the dendrite tip grows faster with countercurrent than that of the latter, while the dendrite grows almost naturally in the vertical direction of convection.
Characteristic of Point Defect around the Photonic Crystal Bend
Authors: Lu Ruei Chang , Wang Chun Min , Lee Keh Yi
Published: September 2012

In this paper, we analyzed the transmission characteristics of the point defects around the 90-degree waveguide bend in photonic crystal. Without suspicion, the nearest defects greatly affect the transmission characteristics, but the farther third layer has more influence than the nearer second layer. Moreover, the defects in line with the propagating path should be avoided. Lastly, the defects in outer side of the corner bend hardly affect the transmission characteristic, but the defects in inner side do the contrary. These results should be helpful in fabricating 2D photonic crystal with 90° bent structure.
Precision Focal Measuring System Based on CCD Aerial Cameras
Authors: Zhao Mei , Sha Yu Fang , Guo Fei , Yang Ming Quan
Published: September 2012

In view of bigger error (0.24%) of conventional measuring method, this paper focuses on a bigger aperture aerial camera focus measuring system and discusses measuring principle and structure of the system. The image in this system is received by the collimator of long focus and area CCD (Charge Coupled Devices) camera. Using dynamic scanning and center of gravity method, the system measures effectively the location and size of the optimum image. The image resolution of CCD can be up to one tenth of the size of the photosensitive sensor and the precision of 0.1percent of focus measuring can be obtained. The problem of the larger error of conventional measuring method is salved fundamentally. The accurate, real-time and on-line measurement of the focus of aerial camera lens can be realized and the exact determination of the position of the surface can be determined.
Study of Aperture-Averaged Scintillation for a Partially Coherent Gaussian Schell-Model Beam Propagation in Slant Atmospheric Turbulence
Authors: Li Ya Qing , Wu Zhen Sen , Zhang Yuan Yuan , Zhang Han Lu
Published: September 2012

Based on the extended Huygens-Fresnel principle, scintillation of a partially coherent Gaussian Schell-model (GSM) beam propagation in weakly slant atmospheric turbulence is studied. The expression of aperture-averaging factor of the system receiver is derived. We analyzed the aperture-averaged scintillation index numerically. A comparison of the aperture-averaged scintillation of the beam propagation in slant path with that of the beam propagation in horizontal path is made. Results obtained show using partially coherent beams and considering aperture-averaging effect can decrease the scintillation and improve the optical communication system performance.
The Three-Dimensional Analysis of Light Scattering Characters for Rayleigh Particles On/Below the Wafer
Authors: Gong Lei , Wu Zhen Sen , Li Ya Qing
Published: September 2012

Laser light scattering is a powerful tool for its noncontract nature and its convenience to nondestructive examination in the semiconductor industry. Taking the advantage of the scattering matrixes, the models of particulate contaminants on the wafer and subsurface defects are established, respectively. And the bidirectional reflectance distribution functions are derived. The results show that when the Rayleigh particle is on the wafer, the variation of BRDFpp is smooth without gulch for a definite incident angle. However, there is a gulch with the increment of scattering angle and the position of gulch is reduced with the increment of incident angle. When the Rayleigh particle is below the wafer, with an identical incident angle, there is a gulch with the variation of scattering azimuth angle. In addition, BRDFpp becomes larger and larger with the incident angle of p polarization light increment. The conclusions provide theoretical basis for quality evaluation and identify the information of contaminants detected in the semiconductor industry.
A Three-Channels WDN Based on Multimode Interference Photonic Crystal
Authors: Yan Jia Han
Published: September 2012

A photonic crystal waveguide coupled structure can be constructed by putting three photonic crystal waveguides in parallel and adjacent form. Study the coupling of the approximate solution interference acts and the self-image phenomenon of this multi-mode waveguide system based on the guided mode propagation analysis method, a three-channels multimode interference wavelength division multiplexing is designed. The presented device not only has a high transmission rate, but also has the advantages of multiple wavelength selection and may have potential and practical applications in the field of photonic integrated circuits in future.
An Improved CSO Resolution Method for IR Sensor Based on Pixel-Cluster Decomposition
Authors: Zhang Hui , Xu Hui , Xu Yang
Published: September 2012

The observation of Closely Spaced Object (CSO) using a space-based IR sensor can result in merged measurements on the focal plane due to the limited resolution and the Point Spread Function (PSF) of optics. This paper proposes an improved CSO resolution method based on pixel-cluster decomposition meeting real-time computation requirement. Simulation are carried out to test the performance of the method, and the results confirm its effectiveness.
Electromagnetically Induced Left-Handedness in a Dense Atomic Vapor Medium
Authors: Wang Li Qiang , Yan Xiang’an
Published: September 2012

We discuss how a three-level system can be used to change the frequency-dependent magnetic permeability of a dense atomic gas to be significantly different from 1. The results show that a negative permittivity and permeability simultaneously with transparent propagation of the electric part of the probe filed can be obtained. Moreover, the magnetic part of the probe field can be amplified instead of strong absorption as usual materials. Therefore, it may be possible to obtain left-handed electrodynamics for an atomic gas using three atomic levels.
Wavelet Analysis of PK2600 Measurement Data on Core-Rod
Authors: Li Hong Sheng , Li Zhen Yu
Published: September 2012

The Core Rod made by Plasma Chemical Vapor Deposition process is measured by PK2600 for Refractive Index Profile. The measurement data is very important to justify the core rod quality. A method based on DWT is presented in this paper to discover some information which is difficult to emerge according to conventional way. The analysis result can be used to optimize the core-rod making process.
Wavelength Division Multiplexer Based on Periodic Dielectric Waveguide Ring Resonator
Authors: Lu Ruei Chang , Chen Tung Hao , Liao Yu Ping
Published: September 2012

In this paper, we propose and investigate an optical wavelength division multiplexer based on periodic dielectric waveguide ring resonator by using finite-difference time-domain method. From the simulation results, compact and high performance wavelength division multiplexer could be obtained to separate the wavelength of 1.31μm and 1.55μm.
Durability of Wood-Polymer Composite Prepared by In Situ Polymerization of Functional Monomers
Authors: Gong Ding Wang , Liu Zhen Bo , Huang Hua Wei , Zhang Chang Qing , Liang Chen
Published: September 2012

Fast-growing plant wood, Micheliamacclurel wood, was modified by formation of wood-polymer composite to improve its decay resistance. Two functional monomers, glycidyl methacrylate and ethylene glycol dimethacrylate, added with a few Azo-bis-isobutryonitrile as initiator, and maleic anhydride as catalyst, were first impregnated into wood cell lumen under a vacuum-pressure condition, and then in-situ polymerized into copolymers through a catalyst-thermal treatment. The decay resistances of untreated wood and wood-polymer composites were assessed by weight loss and compared by SEM observations. SEM and FTIR analysis indicated that the in-situ polymerized copolymers fully filled up wood cell lumen and also grafted onto wood cell walls, resulting in the blockage of passages for microorganisms and moisture to wood cell walls. Thus, the decay resistance of the wood-polymer composite against brown rot fungus and white rot fungus in terms of weight loss achieved 1.04%~1.33%, improved 95.10%~95.35% than those of untreated Micheliamacclurel wood; and also higher than that of boron-treated wood. The SEM observations presented the remarkable improvement of decay resistance of wood after such treatment, which effectively protected wood from degradation by fungi.
Performance Research on Aniline Adsorption from Aqueous Solution by Modified Zeolite/EPDM Composite
Authors: Liu Xiu Qi , Xing He Qin , Chen Hong , Liu Jia Tong
Published: September 2012

In this study, a new composite was prepared for aniline adsorption by melt blending with EPDM as the matrix and natural zeolite was modified by microwave as the filler. The properties and some influential factors of composite for adsorption of aniline in the solutions were experimentally investigated, such as composite dosage, adsorption time and pH values. The results showed that in the case of the initial concentration of the aniline wastewater was 50mg/L, when the use level of composite was 1 g, pH value was 1, and the oscillating adsorption time was 2 h, the removal rate could be up to 92%.
Theoretical Investigation of Energy Splitting of γ-LiAlO2: Co3+ Ceramic
Authors: Huang Yi , Miao Feng , Ma Jian
Published: September 2012

The γ-LiAlO2:Co3+ceramics were successfully fabricated by using multi-mode cavity microwave furnace, and the sample’s infrared absorption and photoluminescence spectra were measured at room temperature. There are nine bands in the range of 1300-48000 cm-1. Using the crystal-field theory and introducing the average covalent factor model, we calculated the energy splittings of Co3+ions in γ-LiAlO2. These bands were firstly explained and assigned. These calculation results are in good agreement with the optical experiment data.
Study on Morphologies of Palladium Coated Foam Nickel Cathodes for Dechlorination of 2,4-Dichlorophenol
Authors: Li Jun Jing , Liu Hui Ling , Wang Zhi Wei , Cheng Xiu Wen
Published: September 2012

Electrolytically deposited palladium on polypyrrole film, which is electropolymerized using potentiostatic method, covered foam nickel electrode as a support was used as cathode for the electrocatalytic hydrodechlorination of 2, 4-dichlorophenol in aqueous solution. It is well known that the morphologies of polypyrrole films have dramatic influences on the dispersion of metals and the performance of the composite electrode. The influence of applied potential, temperature and polymerization time on the morphology of the films was studied by scanning electron microscopy (SEM). The fundamental electrocatalytic hydrodechlorination (ECH) results indicated that the electrocatalytic activity of Pd loaded polypyrrole foam nickel electrode is excellent for dechlorination of 2,4-dichlorophenol. The present study shows a promising choice of this kind of composite electrode for ECH.
Prosys-Laser: Smart Laser Protective Textile Systems
Authors: Dammacco Giada , Wenzel Dirk , Hennigs Christian
Published: September 2012

“Passive” and “active” laser-protective clothing and curtains are hardly available on the market today for the use with hand-held laser processing devices (HLD) and automated laser machines. However, the fact that serious laser injuries of the skin happen shows that skin protection against laser radiation is necessary. Thus, key developments described in this paper are on the one hand highly innovative functional multi-layer technical textiles, providing a high level of passive laser resistance. On the other hand, active systems, containing functional multi-layer smart fabrics which detect laser exposure and, by means of a safety control, deactivate the laser beam automatically, are depicted. Furthermore, test methods and testing set-ups to qualify such passive and active functional technical textiles and tailored personal protective equipment (PPE) are developed. The passive laser-protective textile system will be realized using the best combination of materials, providing, at the same time, laser, fire, and heat protection together with other properties. Designing active system means the realization of functionalized fabrics and to exploit their physical properties. The electronics which interface the active system, providing signal conditioning, acquisition, on-body pre-processing, local data storage and wireless communication, is a major part of the active approach. The electronics will provide alarms and ultimately enforce laser shutdown upon defined conditions.
Structural Conformability and Fluid Uptake Properties of Smart Wound Dressings
Authors: Uzun Muhammet , Anand Subhash , Shah Tahir
Published: September 2012

In this study ten commercial smart wound dressings - CombiDerm®, Versiva® XC®, Sorbsan Plus SA, Opsite* Post-Op, Aquacel™ Surgical, DuoDerm®, Granuflex®, Mepilex® Border, Allevyn Gentle Border and Biatain® - were tested and evaluated. The following experimental tests were performed on the dressing specimens; area density, thickness, fluid uptake and handling, conformability, absorption rate, waterproofness, stainless steel (SS) peel test and vertical wicking. It was found that Biatain® had the highest absorbency and fluid handling capacity and also had lower moisture vapour permeability value compared to the other dressings. Versiva® XC® and DuoDerm® had higher extensibility values than other dressings, which are 3.56 machine direction (MD) and 3.99 (CD) cross direction Ncm-1 for Versiva® XC® and 3.67 (MD) - 3.12 (CD) Ncm-1 for DuoDerm®. The pattern of results for permanent set was found to be similar to the extensibility results. All tested dressings passed the waterproofness threshold. DuoDerm® and Granuflex® showed more than 20 minutes rate of absorption and also their SS Peel values were found to be considerably higher than the other dressings investigated.
Shape Memory Polymers in Textiles
Authors: Hu Jin Lian , Lu Jing
Published: September 2012

This paper highlight the most important areas and directions of shape memory polymers in textiles. The textiles of shape memory polymers involve fibre spinning (including wet-spinning, melt-spinning and electro-spinning), fabric, smart apparel, actively finishing technology and WVP investigation. Based on the molecular structure of shape memory polymer, the shape memory transformation from polymer to textiles and application theory are illustrated and stated. Additionally, the challenges of shape memory polymers in textiles are pointed out and some research directions are also suggested in this paper.
Improvements of Smart Garment Electronic Contact System
Authors: Parkova Inese , Vališevskis Aleksandrs , Ziemele Inese , Briedis Uģis , Vilumsone Ausma
Published: September 2012

In order to improve comfort of smart garment, rigid electronic boards can be replaced with textile circuits, which use conductive yarns. When one tries to improve wearing comfort, often the most problematic items turn to be connection points of the electronic circuitry. The aim of this research is to determine behaviour of conductive yarns after they have been sewn into textile material, as well as to determine their suitability for the intended applications. In order to determine the quality of a conductive connective seams resistance has been measured (in Ω) under the influence of various variable factors: type of yarn, length of stitch, number of layers, type of seam. Besides that seam durability tests were carried, which show resistance changes over time and after washing.
Microfluidic Microchemomechanical Systems
Authors: Allerdissen Merle , Greiner Rinaldo , Richter Andreas
Published: September 2012

The lab-on-a-chip (LOC) technology was expected to influence our every day live in a similarly fundamental way as integrated circuits have. Unfortunately, this demand has not been met yet. The cause therefore lies in the complexity of microelectromechanical systems (MEMS), which form the base of the current LOC technology. We present a new concept of LOC which are based on fluidic microchemomechanical systems (μCMS). During the fabrication process, these μCMS are preprogrammed by monolithic integration of special active components. These active components are holding chemical energy that can be transformed at least once into mechanical energy and thus provide a timed and quantitative exactly defined fluidic function. With our simple and inexpensive fabrication method combined with the above mentioned advantages of the invented μCMS, new and better LOC technology can be developed.
PLZT:Nd3+ Ceramics for Photonic Applications
Authors: Plonska Malgorzata , Pisarski Wojciech A. , Wodecka-Dus Beata , Cienki Lukasz
Published: September 2012

In the present work the influence of neodymium concentration (0-1at-%) and sintering conditions on 8/65/35 PLZT:Nd3+ ceramics were studied. All ceramic powders were synthesized by MOM technique from high purity raw materials (>99,9%), and subsequently sintered by free sintering and hot uniaxial pressing method. To analyze the powders and ceramics more the XRD, EDS SEM, and ferroelectric measurements were performed. Optical spectra were examined for all prepared samples, and their optical properties were analyzed using reflectance, excitation and luminescence measurements. The study gives a detailed account of the relationships between doping and preparing conditions on the basic physical and dielectric and optical properties of obtained ceramic materials.
Real-Time Smart Abstract Shape Identifiers
Authors: Hassan Maguid H.M.
Published: September 2012

Smart structural systems are emerging as a vehicle for implementing semi active control algorithms. Sensors, processors and actuators are the generic basic components of any smart structural system. Sensors are employed in gathering information that could be used by a smart shape identifier in order to define a real-time abstract deformed shape of the system at any given point in time. This information could be employed in proposing a suitable smart control algorithm to suppress the vibration of a given structural system. In this paper, a generic framework for abstract shape identification is developed. The proposed framework employs predefined potential deformed patterns, for a given structural system, in training and/or designing the smart shape identifier. Two applications were developed which employ neural network and fuzzy logic as two potential smart technologies. Both models are capable of indentifying and/or classifying the abstract deformed shape of a three degree-of-freedom structural system in real-time. The neural network model was developed and trained by a single earthquake record then tested using five unseen earthquake records. The fuzzy inference system employed a rule-base that was developed to capture all potential combinations of inter-story deformations then tested using all six earthquake records. The performance of both models was measured by the statistical and geometrical properties of a linear compliance graph. The developed systems were initially designed and tested to model a three-degree-of-freedom system and are now being expanded to model a multi-degree-of-freedom system.
Safety Assessment of Bridge Structures Using Ambient Vibration
Authors: Lee Chin Hyung , You Young Jun , Park Ki Tae , Joo Bong Chul , Lee Bo Mi , Kim Tae Heon
Published: September 2012

In this study, relative load-carrying capacity (RLC) evaluation system in which the change of load-carrying capacity of a bridge structure can be estimated through the variation of the dynamic property, which is induced by the stiffness change due to the deterioration of the bridge, by using ambient traffic-induced vibration was proposed. The system uses the natural excitation technique in conjunction with the eigensystem realization algorithm for identification of modal parameters. Indoor test using a truss-typed model bridge and field measurement were performed to verify the suggested system and it was shown that the RLC estimation system is suitable for the safety assessment of bridge structures in a simple and efficient manner.
Novel Bionic Biomembrane Supported by Gold Nanoparticles/Cellulose Hybrid Films
Authors: Liu Zhi Ming , An Yuan Lin , Wu Wen Jian
Published: September 2012

As one of the main methods to study biomembranes, the construction of highly active bionic biomembrane systems is very important. Based on the hybrid film of gold nanoparticles and cellulose, a novel system of bionic biomembrane is demonstrated. The ratio effects of lecithin to cholesterin on the stability of bilayer lipid membranes are studied. Lipid solutions that can form stable membranes in the air and in some aqueous solutions are prepared. The bionic biomembranes composed of bilayer lipid membranes and hybrid films of gold nanoparticles and cellulose can be sustained for a long period in aqueous solutions. The bionic biomembranes also exhibit some interesting electrochemical properties.
Seasonal forecasts of drought indices in African basins
Authors: Dutra E. , Di Giuseppe F. , Wetterhall F. , Pappenberger F.
Published: September 2012

Abstract. Vast parts of Africa rely on the rainy season for livestock and agriculture. Droughts can have a severe impact in these areas which often have a very low resilience and limited capabilities to mitigate their effects. This paper tries to assess the predictive capabilities of an integrated drought monitoring and forecasting system based on the Standard precipitation index (SPI). The system is firstly constructed by temporally extending near real-time precipitation fields (ECMWF ERA-Interim reanalysis and the Climate Anomaly Monitoring System-Outgoing Longwave Radiation Precipitation Index, CAMS-OPI) with forecasted fields as provided by the ECMWF seasonal forecasting system and then is evaluated over four basins in Africa: the Blue Nile, Limpopo, Upper Niger, and Upper Zambezi. There are significant differences in the quality of the precipitation between the datasets depending on the catchments, and a general statement regarding the best product is difficult to make. All the datasets show similar patterns in the South and North West Africa, while there is a low correlation in the tropical region which makes it difficult to define ground truth and choose an adequate product for monitoring. The Seasonal forecasts have a higher reliability and skill in the Blue Nile, Limpopo and Upper Niger in comparison with the Zambezi. This skill and reliability depends strongly on the SPI time-scale, and more skill is observed at larger time-scales. The ECMWF seasonal forecasts have predictive skill which is higher than using climatology for most regions. In regions where no reliable near real-time data is available, the seasonal forecast can be used for monitoring (first month of forecast). Furthermore, poor quality precipitation monitoring products can reduce the potential skill of SPI seasonal forecasts in two to four months lead time.
Motivating Factors and Psychosocial Barriers to Condom Use among out-of-School Youths in Dar es Salaam, Tanzania: A Cross Sectional Survey Using the Health Belief Model
Authors: Katikiro E. , Njau B.
Published: September 2012

Condoms remain a cost-effective and relatively simple intervention to prevent HIV infection. However, condom use is still very low, particularly among youths aged 15 to 24. 348 individuals (186 males and 162 females) completed a pre-tested questionnaire. Logistic regression analysis was used to identify factors associated with condom use. Out of 348 respondents, 296 (85.0%) were sexually experienced, and 260 (87.8%) reported noncondom use in the past 3 months prior to the study. Among men, noncondom use was independently associated with feeling shy to buy condoms (AOR = 1.16; 95% CI 1.12–1.34), condoms reducing sexual pleasure (AOR = 8.19; 95% CI 3.98–17.01), and HIV is a serious and deadly disease (AOR = 0.36; 95% CI 0.28–0.46). Among women, experiencing forced sex (AOR = 1.16; 95% CI 1.10–2.78), condoms reduce sexual pleasure (AOR = 8.29; 95% CI 3.36–20.73), and inability to convince a partner to use condoms (AOR = 1.14; 95% CI 1.04–1.28) were predictors of noncondom use. In conclusion, sexually active youths in this population practice risky sexual behaviours, with low condom use practices. Strategies to improve condom use should address these psychosocial barriers associated with noncondom use.
Comparison of Measurements of 12 Analytes in Equine Blood Samples Using the In-Practice Falcor 350 and the Reference KoneLab 30i Analysers
Authors: Papasouliotis K. , Tennant K. V. , Dodkin S. , Mason J.
Published: September 2012

Falcor 350 is a wet-reagent biochemistry analyser that is available for in-house use. The aim of this study was to compare the results produced by this analyser with those obtained by the KoneLab 30i that served as the reference instrument. Blood samples from 60 clinical cases were analysed for urea, creatinine, total proteins, albumin, creatine kinase, aspartate aminotransferase, alkaline phosphatase, total bilirubin, total calcium, phosphate, sodium, and potassium using both instruments. Good to excellent correlations (rs value) value) were identified for creatinine (0.88), total proteins (0.92), albumin (0.93), creatine kinase (0.98), aspartate aminotransferase (0.98), alkaline phosphatase (0.94), total bilirubin (0.98), phosphate (0.95), and potassium (0.97). The correlations for total calcium (0.71), sodium (0.68), and urea (0.64) were fair. For albumin, aspartate aminotransferase, creatine kinase, phosphate, potassium, total bilirubin, creatinine, and total proteins, the two instruments produce values that are closely related to each other and are sufficiently similar to allow them to be used interchangeably without the need for additional correction factor computations. Because of differences in the methodologies, the Falcor results for alkaline phosphatase, total calcium, and sodium cannot be used interchangeably and should be interpreted using reference intervals established from the Falcor analyser.
Applications of Steroid in Clinical Practice: A Review
Authors: Shaikh Safiya , Verma Himanshu , Yadav Nirmal , Jauhari Mirinda , Bullangowda Jyothi
Published: September 2012

Steroids are perhaps one of the most widely used group of drugs in present day anaesthetic practice, sometimes with indication and sometimes without indications. Because of their diverse effects on various systems of the body, there has been renewed interest in the use of steroids in modern day anaesthetic practice. This paper focuses on the synthesis and functions of steroids and risks associated with their supplementation. This paper also highlights the recent trends, relevance, and consensus issues on the use of steroids as adjunct pharmacological agents in relation to anaesthetic practice and intensive care, along with emphasis on important clinical aspects of perioperative usefulness and supplementation.
Solid Papillary Carcinoma of the Breast: A Pathologically and Clinically Distinct Breast Tumor
Authors: Saremian Jinous , Rosa Marilin
Published: September 2012

Solid papillary carcinomas are tumors morphologically characterized by round, well-defined nodules composed of low-grade ductal cells separated by fibrovascular cores. These tumors are rare and affect predominantly older women. Although they are considered in situ carcinomas, debate and uncertainty still exist regarding their true nature, because immunohistochemistry for myoepithelial cells has shown absence of myoepithelial cell layer along the epithelial-stromal interface of the tumor in many cases. Clinically, these tumors present as a palpable, centrally located mass or as bloody nipple discharge. Pathologically, solid papillary carcinomas exhibit low-grade features, and often the tumors display neuroendocrine and mucinous differentiation. In the majority of cases an associated invasive carcinoma is present, with colloid and neuroendocrine carcinomas being the most common. The pathologic differential diagnosis is broad and ranges from benign to malignant lesions. The treatment for solid papillary carcinomas is surgical excision. When invasive carcinoma is not present, the prognosis is excellent.
Power Indices and U.S. Presidential Elections
Authors: Colen Yong S. , Navaratna Channa , Colen Jung , Kim Jinho
Published: September 2012

The 2000 presidential election provides an ideal backdrop for introducing the electoral voting system, weighted voting, and the Banzhaf and Shapley-Shubik Power Indices.
Blood‐Inert Surfaces via Ion‐Pair Anchoring of Zwitterionic Copolymer Brushes in Human Whole Blood
Authors: Chang Yung , Shih Yu‐Ju , Lai Chia‐Jung , Kung Hsiao‐Han , Jiang Shaoyi
Published: September 2012

A strategy to create blood‐inert surfaces in human whole blood via ion‐pair anchoring of zwitterionic copolymer brushesand a systematic study of how well‐defined chain lengths and well‐controlled surface packing densities of zwitterionic polymers affect blood compatibility are reported. Well‐defined diblock copolymers, poly(11‐mercaptoundecyl sulfonic acid)‐block‐poly(sulfobetaine methacrylate) (PSA‐b‐PSBMA) with varying zwitterionic PSBMA or negatively charged PSA lengths, are synthesized via atom‐transfer radical polymerization (ATRP). PSA‐b‐PSBMA is grafted onto a surface covered with polycation brushes as a mimic polar/hydrophilic biomaterial surface via ion‐pair anchoring at a range of copolymer concentrations. Protein adsorption from single‐protein solutions, 100% blood serum, and 100% blood plasma onto the surfaces covered with PSA‐b‐PSBMA brushes is evaluated using a surface plasmon resonance sensor. Copolymer brushes containing a high amount of zwitterionic SBMA units are further challenged with human whole blood. Low protein‐fouling surfaces with >90% reduction with respect to uncoated surfaces are achieved with longer PSA blocks and higher concentrations of PSA‐b‐PSBMA copolymers using the ion‐pair anchoring approach. This work provides a platform to achieve the control of various surface parameters and a practical method to create blood‐inert surfaces in whole blood by grafting ionic‐zwitterionic copolymers to charged biomaterials via charge pairing.
Nanocasting of Mesoporous In‐TM (TM = Co, Fe, Mn) Oxides: Towards 3D Diluted‐Oxide Magnetic Semiconductor Architectures
Authors: Pellicer Eva , Cabo Moisés , Rossinyol Emma , Solsona Pau , Suriñach Santiago , Baró Maria Dolors , Sort Jordi
Published: September 2012

Transition metal (Co, Fe, Mn)‐doped In2O3−y mesoporous oxides are synthesized by nanocasting using mesoporous silica as hard templates. 3D ordered mesoporous replicas are obtained after silica removal in the case of the In‐Co and In‐Fe oxide powders. During the conversion of metal nitrates into the target mixed oxides, Co, Fe, and Mn ions enter the lattice of the In2O3 bixbyite phase via isovalent or heterovalent cation substitution, leading to a reduction in the cell parameter. In turn, non‐negligible amounts of oxygen vacancies are also present, as evidenced from Rietveld refinements of the X‐ray diffraction patterns. In addition to (In1−xTMx)2O3−y, minor amounts of Co3O4, α‐Fe2O3, and MnxOy phases are also detected, which originate from the remaining TM cations not forming part of the bixbyite lattice. The resulting TM‐doped In2O3−y mesoporous materials show a ferromagnetic response at room temperature, superimposed on a paramagnetic background. Conversely, undoped In2O3−y exhibits a mixed diamagnetic‐ferromagnetic behavior with much smaller magnetization. The influence of the oxygen vacancies and the doping elements on the magnetic properties of these materials is discussed. Due to their 3D mesostructural geometrical arrangement and their room‐temperature ferromagnetic behavior, mesoporous oxide‐diluted magnetic semiconductors may become smart materials for the implementation of advanced components in spintronic nanodevices.
Nanostructured Alkaline‐Cation‐Containing δ‐MnO2 for Photocatalytic Water Oxidation
Authors: Boppana Venkata Bharat Ram , Yusuf Seif , Hutchings Gregory S. , Jiao Feng
Published: September 2012

Oxygen evolution from water is one of the key reactions for solar fuel production. Here, two nanostructured K‐containing δ‐MnO2 are synthesized: K‐δ‐MnO2 nanosheets and K‐δ‐MnO2 nanoparticles, both of which exhibit high catalytic activity in visible‐light‐driven water oxidation. The role of alkaline cations in oxygen evolution is first explored by replacing the K+ ions in the δ‐MnO2 structure with H+ ions through proton ion exchange. H‐δ‐MnO2 catalysts with a similar morphology and crystal structure exhibit activities per surface site approximately one order of magnitude lower than that of K‐δ‐MnO2, although both nanostructured H‐δ‐MnO2 catalysts have much larger Brunauer–Emmett–Teller (BET) surface areas. Such a low turnover frequency (TOF) per surface Mn atom might be due to the fact that the Ru2+(bpy)3 sensitizer is too large to access the additional surface area created during proton exchange. Also, a prepared Na‐containing δ‐MnO2 material with an identical crystal structure exhibits a TOF similar to that of the K‐containing δ‐MnO2, suggesting that the alkaline cations are not directly involved in catalytic water oxidation, but instead stabilize the layered structure of the δ‐MnO2.
Scaffold/Extracellular Matrix Hybrid Constructs for Bone‐Tissue Engineering
Authors: Thibault Richard A. , Mikos Antonios G. , Kasper F. Kurtis
Published: September 2012

The limited natural ability of the body to fully repair large bone defects often necessitates the implantation of a replacement material to promote healing. While the current clinical strategies to address such bone defects generally carry associated limitations, bone‐tissue engineering approaches seek to minimize any adverse effects and facilitate complete regeneration of the lost tissue. Of particular interest are hybrid constructs that incorporate multiple components found within the native bone matrix to enhance the osteogenicity of biocompatible materials, which might otherwise be non‐osteogenic. This Progress Report will focus on such hybrid constructs that incorporate multiple components from native bone matrix for bone‐tissue engineering and will highlight the synthesis and characterization of the hybrid constructs, cellular attachment and proliferation within the constructs, in vitro osteogenicity of the constructs, and the biological response to in vivo implantation of the constructs at ectopic and orthotopic sites.
A Unique Ruthenium Carbyne Complex: A Highly Thermo‐endurable Catalyst for Olefin Metathesis
Authors: Shao Mingbo , Zheng Lu , Qiao Weixia , Wang Jingjing , Wang Jianhui
Published: September 2012

A cationic ruthenium carbyne complex was prepared and was found to initiate olefin metathesis reactions with good activities, which throws a new light on the design of a new type of ruthenium catalyst for RCM reactions. More importantly, no double bond isomerized by‐product was observed even at elevated temperatures in reactions catalyzed by the new carbyne complex. A mechanism involving the in situ conversion of the ruthenium carbyne to a ruthenium carbene complex via addition of an iodide to the carbyne carbon was also proposed.
Enantiocontrolled Synthesis of Tertiary α‐Hydroxy‐α‐ynyl Esters by Dimethylzinc‐Mediated Addition of Alkynes to α‐Keto Esters
Authors: Infante Rebeca , Gago Alfonso , Nieto Javier , Andrés Celia
Published: September 2012

A perhydro‐1,3‐benzoxazine behaves as an excellent chiral ligand in the nucleophilic addition of alkynylzinc derivatives, prepared from terminal alkynes and dimethylzinc, to α‐keto esters without using other Lewis acids. The enantioselectivity is excellent and homogeneous for a wide variety of aromatic and heteroaromatic α‐keto esters. Aliphatic enolizable α‐keto esters were alkynylated with moderate enantioselection.
Asymmetric Michael Reaction of Acetaldehyde with Nitroolefins Catalyzed by Highly Water‐Compatible Organocatalysts in Aqueous Media
Authors: Qiao Yupu , He Junpeng , Ni Bukuo , Headley Allan D.
Published: September 2012

A novel category of diarylprolinol silyl ether catalysts which contain different lengths of alkylamine tags, was designed and synthesized. These catalysts were used, along with benzoic acid as the co‐catalyst, to catalyze the asymmetric Michael reaction of the highly reactive acetaldehyde with nitroolefins. For the reactions studied, this catalytic system exhibited high reactivity in brine without any organic solvents; good yields (30–61%) and high enantioselectivities (80–97% ee) for a wide variety of nitrostyrenes were obtained.
Synthesis of Azocino[5,4‐b]indoles via Gold‐Catalyzed Intramolecular Alkyne Hydroarylation
Authors: Peshkov Vsevolod A. , Pereshivko Olga P. , Eycken Erik V. Van der
Published: September 2012

An efficient procedure for the synthesis of the azocino[5,4‐b]indole framework is presented, relying on a cationic gold‐catalyzed intramolecular alkyne hydroarylation of propargylic amides derived from various tryptamines and 3‐substituted 2‐propynoic acids. The triphenylphosphinegold(I) chloride/silver(I) triflate catalytic system was found to be superior to our previously described mercury(II) triflate catalyst, and hence the substrate scope of the process was significantly expanded.
Selective Hydrogenation of Nitroarenes and Olefins over Rhodium Nanoparticles on Hydroxyapatite
Authors: Huang Lei , Luo Pingfei , Pei Weige , Liu Xiaoyun , Wang Yong , Wang Jun , Xing Weihong , Huang Jun
Published: September 2012

We have demonstrated a highly active and selective nanocatalyst, Rh/HAP (rhodium supported on hydroxyapatite), for the reduction of nitroarenes with hydrazine and for the hydrogenation of olefins with hydrogen gas under mild conditions. Nitroarenes were hydrogenated selectively to the corresponding anilines over the Rh/HAP catalyst with hydrazine as reducing agent, and reducible groups, such as halides (fluorine, chlorine, bromine and iodine), cyano and alkene were untouched. Moreover, olefins can be hydrogenated selectively to the corresponding alkanes in good yields over the Rh/HAP catalyst in the presence of reducible nitro, carbonyl and cyano groups when H2 was used.
Tin Tetrachloride‐Catalyzed Regiospecific Allylic Substitution of Quinone Monoketals: An Easy Entry to Benzofurans and Coumestans
Authors: Liu Yingjie , Liu Jingxin , Wang Mang , Liu Jun , Liu Qun
Published: September 2012

A highly regioselective allylic substitution of quinone monoketals with α‐oxoketene dithioacetals is achieved under the catalysis of only tin tetrachloride (1 mol%). The advantages of the reaction, including its simplicity, rapidity, low catalyst loading of inexpensive tin tetrachloride, mild conditions and; in particular, the regiospecificity, is proposed to be due to a pseudo‐intramolecular process. This new synthetic method provides a facile [3+2] cycloaddition route to benzofurans and is highlighted by the synthesis of coumestans.
Retropinacol/Cross‐Pinacol Coupling Reactions – A Catalytic Access to 1,2‐Unsymmetrical Diols
Authors: Scheffler Ulf , Stößer Reinhard , Mahrwald Rainer
Published: September 2012

A new concept to access unsymmetrical 1,2‐diols with high yields is reported. This new methodology is based on a retropinacol/cross‐pinacol coupling process. This transformation is characterized by its operational simplicity and very mild reaction conditions.
A rare association of fibromuscular dysplasia, renal agenesis, renal arteriovenous fistulae, and vertebral anomalies: Expanding the V in VACTERL association
Authors: Alomari Ahmed K. , Alomari Ahmad I.
Published: September 2012

We report on the association of renal agenesis, renal arteriovenous fistulae, fibromuscular dysplasia and vertebral body anomaly in a young female patient with renovascular hypertension. We believe these vertebral and vascular anomalies can be included under the “V” of the VACTERL association; expanding the vascular spectrum of this complex disorder. © 2012 Wiley Periodicals, Inc.
2q24 deletions: Further characterization of clinical findings and their relation to the SCN cluster
Authors: Nimmakayalu Manjunath , Noble Nathan , Horton V. Kim , Willing Marcia , Copeland Sara , Sheffield Val , Nagy Peter L. , Wassink Tom , Patil Shivanand , Shchelochkov Oleg A.
Published: September 2012

As the resolution of molecular cytogenetic methods continues to improve, it has become increasingly possible to refine genotype–phenotype correlations based upon gene involvement. We report three new patients with nonrecurrent deletions involving subbands of 2q24. These patients were referred for evaluation of developmental delay, but were found to have unique, nonoverlapping clinical features. Patient 1 presented with infantile seizures, microcephaly, and brain anomalies, along with facial dysmorphism, growth retardation, neuromuscular scoliosis, and later with developmental regression. Array comparative genomic hybridization (aCGH) detected an 8 Mb interstitial deletion encompassing the neuronal sodium channel (SCN) gene cluster. Patient 2 presented with growth retardation, congenital heart defect, and hypotonia. Patient 3 presented with developmental delay and behavioral problems. Patients 2 and 3 had no history of seizures, microcephaly, or brain anomalies and were found to have deletions of 2q24, ∼8 Mb and <500 kb respectively, centromeric to and outside the SCN cluster. It has been demonstrated that mutations and copy number variants (CNVs) affecting the SCN gene cluster result in severe, early‐onset seizures. It is however, less clear whether haploinsufficiency of regions outside the SCN cluster may result in phenotypically recognizable and clinically significant features. We discuss additional dosage sensitive genes that may exist outside the SCN cluster. Our and published data indicate that 2q24 deletions not involving the SCN cluster are associated with fewer neurobehavioral problems, but may predispose to congenital malformations. © 2012 Wiley Periodicals, Inc.
Apolipoprotein E genotype and neurological disease onset in Niemann–Pick disease, type C1
Authors: Fu Rao , Yanjanin Nicole M. , Elrick Matthew J. , Ware Christopher , Lieberman Andrew P. , Porter Forbes D.
Published: September 2012

Niemann–Pick disease, type C1 (NPC1) is a lipid storage disorder that results in progressive neurological impairment. The NPC1 phenotype is extremely variable and at the individual level is likely influenced by other genetic traits. In addition to residual function of NPC1 protein, we hypothesize that modifier genes, as frequently observed with other autosomal recessive diseases, influence the NPC phenotype. The NPC1 phenotype includes progressive dementia, and the NPC pathology has some overlap with the pathology of Alzheimer disease (AD). Thus, we examined apolipoprotein E (ApoE) and microtubule‐associated protein tau (MAPT) polymorphisms in a cohort of 15 NPC1 patients with well characterized longitudinal disease progression. Although we did not find any correlations between disease severity and tau polymorphisms, we found significant associations between ApoE polymorphisms and phenotypic severity. Specifically, ApoE4 and ApoE2 alleles were associated, respectively, with increased and decreased disease severity in this cohort of NPC1 patients. These data support the hypothesis that ApoE may play a role in modulating NPC1 neuropathology. © 2012 Wiley Periodicals, Inc.
Synthesis of Vasorelaxaing 1,4‐Disubstituted 1,2,3‐Triazoles Catalyzed by a 4′‐Phenyl‐2,2′:6′,2′′‐Terpyridine Copper(II) Complex Immobilized on Activated Multiwalled Carbon Nanotubes
Authors: Sharghi Hashem , Ebrahimpourmoghaddam Sakineh , Doroodmand Mohammad Mahdi , Purkhosrow Azar
Published: September 2012

A supported catalyst has been prepared by immobilization of a copper(II) complex of 4′‐phenyl‐2,2′:6′,2′′‐terpyridine on activated multiwalled carbon nanotubes [AMWCNTs‐O‐CuII‐PhTPY]. This heterogeneous catalyst was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), inductively coupled plasma (ICP) analysis, UV/vis and FT‐IR techniques. To ensure the efficiency and fidelity of the copper species, the implementation of three‐component strategies in click chemistry was tested. The catalyst enabled the development of one‐pot, two‐step, mild, and environmentally benign syntheses of diversely decorated 1,2,3‐triazoles from alkynes, epoxides or benzyl/alkyl halides, and sodium azide in water. The complex has high catalytic activity, regioselectivity, and was recycled five successive times. In another experiment, the vasorelaxing effect of the triazole products was studied in isolated rat thoracic aorta. All of the selected compounds are vasorelaxants, based on the IC50 values obtained, and the vasorelaxing potency and maximal response for three of the compounds are comparable to acetylcholine.
Synthesis and characterization of chitosan‐graft‐poly(acrylic acid)/nontronite hydrogel composites based on a design of experiments
Authors: Rodrigues Francisco H. A. , Pereira Antonio G. B. , Fajardo André R. , Muniz Edvani C.
Published: September 2012

A 24–1 fractional factorial design was used to evaluate the effect of some parameters, such as the acrylic acid (AA)/chitosan (CTS) molar ratio, crosslinker concentration, initiator concentration, and filler concentration, in the swelling capacity of superabsorbent hydrogel composites based on CTS‐graft‐poly(acrylic acid) and nontronite clay. The data from wide‐angle X‐ray scattering and Fourier transform infrared spectroscopy confirmed the syntheses of the hydrogel composites. Main and interaction effects were analyzed by analysis of variance, F tests, and p values. We found that the AA/CTS and crosslinker were the most influential effects in the evaluated response. The proposed statistical model presented a high coefficient of determination (R2 = 0.985). In addition to the swelling kinetics, the effects of pH and salt for the both compositions (with and without filler), which presented the best water uptake, were evaluated. Both hydrogels showed responsive behavior in relation to the pH and the salt solution, presenting good potential for application as devices in the controlled release of solutes. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013