bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of Gas Utilization Efficiency in Injection Refining Process
Authors: Liu Yan , Zhang Ting An , Masamichi Sano , He Ji Cheng
Published: December 2011

According to practical situation of Mg-based desulphurization, this paper has defined the formula of bubble effectiveness with low ratio of height to diameter, and derived the theoretical formula of the bubble utilization rate relating to gas flow rate, bubble diameter and mass transfer coefficient. When the absorption rate is treated as first order reaction, the theoretical formula is presented which includes physical conditions, equipment conditions and operating conditions. It indirectly reflects the three conditions on the effective of bubble utilization rate. The calculation formula of bubble utilization rate at different sizes and different residence time distribution is derived.
Structure Design and Force Analysis of Dushan Inverted Siphon Engineering
Authors: Du Pei Rong , Li Xiao Fen
Published: December 2011

This paper adopt computer which is a efficient computational tool, analyzing Dushan inverted siphon structure, researching variation law of the inverted siphon’s stress and displacement in construction process and operational process. Research results further verified rationality and security of the design schemes, which provides reliable reference for construction and operational of inverted siphon structure.
Structure Evolution of Fe-7.5at.%Ni Alloy Thin Strips under Near-Rapid Solidification Conditions
Authors: Guo Yuan Yi , Zhu Liang , Xie Ke , Li Ke Feng , Song Chang Jiang , Zhai Qi Jie
Published: December 2011

In this paper, the structure evolution of Fe-7.5at.%Ni thin strips under near-rapid solidification conditions was investigated. One-dimensional (1D) heat transfer model was used to calculate the cooling rate of thin strips. The calculated results showed that the decrease of distance from the surface, made the effective heat transfer increase sharply, which led to a higher cooling rate. Moreover, the experimental results showed that the size of the columnar crystals increased clearly by the increase of the distance from the surface, and equiaxed grains appeared when the distance was above 0.75mm. In addition, it is indicated that even the strip thickness changed from 1.0mm to 2.0mm, the size of columnar crystals didn’t change much in regions which have the same distance from the surface.
A Thermo-Sensitive Laser Imaging Composition Derived from a Modified Phenolic Resin
Authors: Pu Jia Ling , Li Zhong Xiao
Published: December 2011

The performances of CTP plate depend heavily on polymer binder and those capable of producing large image contrast by exposure are keys to quality plate. This research proposed a polymer resin containing hydrophilic spices in the side chain which could be sheltered by the thermal induced crosslinking reaction during plate manufacturing process and released upon imaging exposure. The resin was prepared through esterification reaction of maleic anhydride with phenolic resin, and its chemical structure was characterized by IR spectrum. Plate coatings were formulated with the modified polymer as binder resin, 2,2-bis(4- (2-(vinyloxy)ethoxy)phenyl)propane as the crosslinking agent, a near infrared absorbing dye and crystal violet as the tracing agent. Solubility of the exposed and unexposed coatings in diluted aqueous alkaline was investigated in situ using a home-made dissolving rate tester. It was found that polymer containing 4-6% mole carboxyl groups led to high image contrast and this contribution came directly from the cross-linking and decrosslinking reactions. Preliminary test indicated that this polymer coating generated positive image of high contrast after exposure and could be used as CTP plate coating for thermal laser imaging.
Effect of Sintering Conditions on the Properties of Mn-Zn Ferrites Produced by Co-Precipitation
Authors: Wang Gui Xin , Wu Hong Xia , Jiang Yan Fei , Peng Hui Fen , Wang Xin
Published: December 2011

Mn0.49Zn0.48Fe2.06O4ferrite nano-powders were prepared by co-precipitation method and pressed into ring samples by dry pressing to study the effect of sintering atmosphere, sintering temperature and heating rate on properties of Mn-Zn Ferrites. X ray diffraction (XRD), scanning electron microscopy (SEM), and vibration sample magnetometer (VSM) were used to characterize properties of the obtained samples. It was shown that the samples sintered in nitrogen contained no impurities with cubic spinel structure. The samples sintered at 880°C with heating rate of 5°C/min had a density of 4.82 g•cm-3, high quality factor Q of 57 at a frequency of 2MHz, high saturation magnetization Ms of 90.02emu•g-1.
Thermal Cracking Resistance of Shotcrete Based on Temperature Matched Curing
Authors: Chen Bo , Ding Jian Tong , Cai Yue Bo , Kang Qiu Bo
Published: December 2011

In order to evaluate the thermal cracking resistance of shotcrete under the condition of practical temperature field and strong restrain, a proper test method is needed. Based on temperature matched curing and by applying temperature stress testing machine, a new test method has been provided. With the application of this test method, thermal cracking resistance of three shotcretes with different types of fiber were investigated. Test results show that the cracking tendency of different shotcretes can be distinguished with the parameter of the difference between the max temperature and the cracking temperature.
Microstructure and Properties of 0.2mm Thick Sheet Titanium Alloy by Micro-Laser Welding
Authors: Yu Liang , Chen Yu Hua , Gong Wei Huai
Published: December 2011

0.2mm thick titanium alloy sheet was butt-welded using micro impulse laser, influnce of the different processing parameter on the surface and cross-section morphology of welded joint was studied , testing the mechanical properties of joints. The result show that argon as a shielding gas, 0.2mm thick titanium alloy to the laser as heat source can be successful butt welding with process parameters of the pulse power 8.8W, pulse width 2.9ms, pulse frequency 7.0HZ, and forming a good welded appearance, the tensile strength and microhardness of welded joints was higher than the base metal. By the needle-like martensite α 'phase composition of the basket-like structure located in the center of the weld.
One-Step Synthesis of Methyl Isobutyl Ketone from Acetone Catalysed by Ni-Zirconia
Authors: Du Chang Hai , Yang Zhuo Min , Zhao Guo Bin , Zhu Li Jie
Published: December 2011

The one-step synthesis of methyl isobutyl ketone from acetone (MIBK) and H2 in liquid phase was studied over Ni-zirconia catalyst prepared by precipitation. The performances of Ni/ZrO2 catalysts were evaluated by the conversion of acetone and the selectivity of MIBK. The effect of different preparation conditions such as aging temperature, calcination temperature, nickel content and reduction temperature was investigated. The results showed that high acetone conversions of up to 33% and MIBK selectivities of up to 85% were recorded at a nickel content of 13.0 wt % and the reduction temperature of 400°C.
Alkali-Thickening Characteristics of Vinyl Acetate and Vinyl Ester Versatic Acid Copolymer Latex Using Carboxylic Monomers
Authors: Liu Hai Ying , Gu Ji You , Zhao Huan
Published: December 2011

VAc/Veova10/MAA copolymer latex containing carboxyl groups was synthesized by the semi-continuous seed emulsion polymerization with vinyl acetate (VAc), vinyl ester of versatic acid (Veova10) and methacrylic acid (MAA). Alkali-thickening characteristics of VAc/Veova10/MAA copolymer latex containing carboxyl groups, adjusted from pH 5.5 to 6.4, 8.9, 9.8 with NaOH aq., were investigated by DSC. The results showed that the viscosities of VAc/Veova10/MAA copolymer latex were increased with the inceasing of pH, The frozen temperature peaks were observed to increase with the increasing of pH, the thawed temperature peaks were shifted to lower temperature, and the state of water in latexes were different. The partial morphologies of latexes were irregular and latexes were pseudoplastic fluid. And water absorption of films were increased with the increasing of pH in latexes and dry and wet shear strengths were also decreased.
Effect of Doping Cation Valencies on Low Temperature Performance of LiFePO4/C
Authors: Li Ning , Wu Bo Rong , Zhou Chuan Xiong , Ren Yong Huan , Yang Chun Wei , Yao Jing Wen , Wu Feng
Published: December 2011

The doped and undoped LiFePO4/C samples are prepared by two-step solid-state reaction. The X Ray Diffraction (XRD) results indicate that metal ions are successfully doped in LiFePO4 without any unexpected phase. The Scanning Electron Microscope (SEM) shows that the particle morphologies of samples are near-spherical with about 200-300nm size which can be observed in all samples. The electrochemical tests indicate that doping oversize ions will increase electrode polarization. The limitation of the Li+ migration is intensified by doping metal ions with high valence. LiFePO4/C samples doped with Mn2+ and Ti4+behave better at low temperature, especially the one doped with Ti4+. Battery with this Ti4+doped material can yield 77mAhg-1 when discharge at -20°C and 0.5C, about 26mAhg-1 higher than the undoped one.
Functional Modification of Xylan-Rich Hemicelluloses in Ionic Liquid
Authors: Peng Xin Wen , Ren Jun Li , Zhong Lin Xin , Huang Yan Bo , Sun Run Cang
Published: December 2011

Xylan-rich Hemicelluloses (XH) isolated from wheat straw were converted to functional biopolymers by modification using succinic anhydride (SA) as reactant without catalyst in 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) ionic liquid. The reaction was performed under various conditions such as different temperatures, different times, and the different amounts of SA, and the effect of reaction factors on the degree substitution (DS) of products were discussed. The product had the maximum DS of 1.80. The structure of modified hemicellulosic derivatives (MD) was actually confirmed by13C NMR spectroscopy. The thermal behavior of MD was monitored by means of thermogravimetry (TG) and differential thermal analysis (DTA), and the thermal stability of MD was lower than XH.
Synthetic Flow-Field Analysis of Main and Auxiliary Nozzles in Air-Jet Looms
Authors: Song Shuan Jun , Shen Dan Feng
Published: December 2011

The synthetic flow-field model of main and auxiliary nozzle flow-field in air-jet loom is introduced. The software of computational fluid dynamics FLUENT is used for the first time to simulate synthetic flow-field, and velocity vector is analyzed. To different spray angles of auxiliary nozzle, the velocity and total pressure of central air are compared in brief. The boundary conditions are changed by User Defined Functions (UDF) and the comparison analysis is done before and after using UDF.
A Feeding System Control of NC Honing Machines Based on Fuzzy Neural Network
Authors: Zhao Jia Li , Sun Zhen Ju , Yang Ning Du
Published: December 2011

The principle of feeding system for NC honing machines is described and the mathematical model of hydraulic feeding system is built in this paper.A fuzzy netural network(FNN) with BP feedback is suggested,which is applied to improve the self-learning ability and dynamic performance of the feeding system. Simulation results are given and performance comparisons with fuzzy control are conducted,highlighting the modeling characteristics of FNN as a controlling method and an effectiveness for feeding system to control the feeding system.
Dynamic Response of the Double Loop DC Motor Control System with the Different Moment of Inertia
Authors: Sun Feng , Wang Niu , Zhang Guo Feng
Published: December 2011

According to the relation of inertia moment and electromechanical time constant, dynamic structure and inertia moment of double loop DC motor control system is proposed. The effect of the moment of inertia on the dynamic response process of the double-loop DC control system is analyzed. In addition, the mathematical relation of the inertia moment and the rotation acceleration for the double-loop DC control system is discussed. Lastly, the effectiveness of the mathematical relation is verified through the experiment of the actual system.
Optimization and Analysis of WEDM Process Parameters Based on Nonlinear Regression Model
Authors: Qiang Huai Bo , Wu Qiong
Published: December 2011

The process parameters of wire cut electrical discharge machining were optimized to improve machining quality and efficiency.The nonlinear regression model of process parameters and processing index was established. The objective function is presented by test method and an optimization result containing multiple parameters was achieved. The results show that the nonlinear regression model can accurately reflect the relation between process parameters and quality index.
Research on Process Planning Method of NC Tube Bending
Authors: Zhang Jin Rong , Li Feng , Zhu Qiang , Wang Yong Jun
Published: December 2011

In order to improve efficiency and quality of tube process, a new process planning method for NC tub bending is proposed. Factors affecting NC tube bending process is firstly discussed, and NC bending process planning is also achieved by theoretical process set calculation, occurrence of interference processes set analysis, clamping difficult process analysis and optimal set of processes selection. The method above is effective and useful for planning process of the complex tube bending parts.
Achieving the Measurement of Tool Diameter by the Boundary Tracing Algorithm Based on Model
Authors: Lai Yue Shen , Shi Meng , Tian Jun Wei , Cheng Gang
Published: December 2011

Boundary tracing method is an important preprocessing instrument for image recognition and image measurement, but the traditional boundary tracing method exits a conflict between the veracity and the speed. In response to these problems, we propose the boundary tracking algorithm based on the model, and then obtain the tool diameter. Experiments show that the boundary tracking algorithm can achieve a good boundary track. Compared two algorithms of diameter measurements, we obtain that the least square method runs shorter, and more efficient.
Calculation of Phonon Dispersion for 3d Transition Metals Cr and Fe by Modified Analytic Embedded Atom Method
Authors: Xie You , Zhang Jian Min
Published: December 2011

The modified analytical embedded atom method is applied to calculate the phonon dispersion of body-centered cubic 3d transition metals Cr and Fe along five symmetry directions [q 0 0], [1 q q], [q q q], [q q 0] and [1/2 1/2 q]. Our results of phonon dispersion curves are in good agreement with the available experimental data. For the two transition metals Cr and Fe, along the same direction, a similar phonon dispersion curve is obtained in spite of the phonon frequency decreases for Cr and Fe due to the atom mass increases. There are no experimental results for comparison along the directions [1 q q] and [1/2 1/2 q], further experimental measurement are needed.
Analysis and Prospect of Wireless Sensor Network Routing Technology
Authors: Duan Qun , Zhao A Ni
Published: December 2011

A wireless sensor network integrates sensor technology, embedded computing technology, modern networking and wireless communication technology, distributed information processing technology to form a wireless network. This paper analyzes the architecture of the wireless sensor network and its routing features, analyzes current wireless sensor network routing protocols, and summarizes wireless sensor routing technology development prospects.
Study on Modeling of Digital Machining Process and its Condition Monitoring & Diagnosis Method
Authors: Cao Hong Rui , Li Bing , He Zheng Jia
Published: December 2011

Based on a cutting dynamics model, a new digital machining process model that integrates workpiece quality and machining condition information is proposed, and the mapping relationship between machine tool structural dynamics and product quality information (e.g., dimension error, surface shape) is analyzed in detail. On the basis of the digital machining process model, the condition monitoring and fault diagnosis method of the machining process is investigated, and an implementation flowchart of the method is proposed with explanations of critical techniques. Finally, the proposed model is applied to the condition monitoring and fault diagnosis of the machining process of a CNC end milling machine. The damage of its spindle bearing is detected successfully, which provides the proof for the root cause identification of machining error in the digital machining process.
Position Stability Analysis of Gripper Bars on Die-Cutting Machine
Authors: Wang Fang , Chen Hong , Zhao Mei Ning
Published: December 2011

Position stability analysis of gripper bars on die-cutting machine is one of the important factor which affects machining quality and production capacity. By introducing comprehensive influence parameter period ratio such as machine speed and mechanism natural frequency,mathematical model of gripper bars in stopping period has been established. The results indicate that dynamic motion error of gripper bars in stopping period show an increasing tendency so as to affect stable position with the increasing of period ratio. To ensure a stable position state in stopping period, finally two solutions are given out to satisfy high accuracy.
Development of Parametric Design System for Disc Cams with Translating Roller Followers
Authors: Wang Lin Yan , Shen Tao , Shen Yun Bo , Li Shao Kang
Published: December 2011

The parameterized design system of disc cams with translating roller followers was studied. The secondary development of AutoCAD was chosen as the developing tool. According to the design theories of the disc cam, the solution steps of the best offset and base circle radius were proposed in this work. All the solution steps meet the requirements of the motion parameters of the push bar. The method of identifying the reasonable step angle for the given fitting precision was developed. The profile curve of the disc cam can be drawn automatically and saved as the ‘dwg’ format file. Finally, an example was used to verify the feasibility of the system.
Kategeet en geloofsvorming: Perspektiewe vanuit die Praktiese Teologie
Authors: Venter Casper J.H.
Published: December 2011

Scrutinising this topic is an attempt to equip catechists more extensively in serving and furthering the forming of faith in the process of formal catechesis given to children. An additional aim is to highlight an outcome indicated in certain practical-theological studies, that is, that the rational dimension in the forming of faith should not be accentuated one-sidedly in formal catechetical ministry within faith communities. On basis-theoretical level the following aspects are investigated: a closer definition of faith from Hebrews focusing on the forming of faith by means of catechesis; the action of learning in the forming of faith; the sequence in the action of teaching as indicated in Scripture; the gifts of the Holy Spirit in intermediating the process of forming faith; the way and attitude in which the catechist fulfils his or her ministry, and in last instance, the spirituality of the catechist. On metatheoretical level applicable aspects from the field of Emotional and Social Intelligence are investigated. Data from the field of Emotional Intelligence that should be part of the catechist’s teaching equipment point to the necessity of being conscious of aspects such as self-awareness, self-control, self-motivation and social skills. Contributions from the field of Social Intelligence include attitudes and skills like empathy, the ability of presenting oneself effectively in formulating ideas, the authority with which the catechist communicates, and his or her caring for someone else’s needs. In final instance, relevant practice-theoretical perspectives that can be applied in catechetical ministry, and specifically in the forming and passing on of faith, are outlined.
Die konstellasie taalbegrip-logika in die Middeleeuse filosofie (1): Augustinus tot Aquinas
Authors: Beukes Johann
Published: December 2011

The constellation language-logic in medieval philosophy (1): St Augustine to St Aquinas This series of two articles provides an in-depth overview of some of the most prominent (and some of the most underpublished) medieval thinkers’ stance on the constellation of language and logic, thus as a combined and condensed problem in Western philosophy between the 5th and 15th centuries. The articles form part of a rehabilitating series of modern-critical articles on understated and marginalised themes, texts and figures in medieval philosophy. The positions of the well-known philosophers that are covered in the two articles, St Augustine, Peter Abelard, St Thomas Aquinas, John Duns Scotus and William of Ockham, are juxtaposed with some less familiar philosophical positions, amongst others those of Boethius, Peter of Spain, John Wyclif and Peter de Rivo.
The Holy Spirit and the Early Church: Doctrine & Confession
Authors: Van Oort Johannes
Published: December 2011

This article firstly investigates in what way various main theological figures in the first centuries of the Christian era spoke about the Trinity and thus, also, about the Holy Spirit. Secondly, it investigates how the formulas of Early Christian confessions of faith developed into their mature and final forms. Such (baptismal) confessions often reveal trinitarian expressions and explicit wordings about the Holy Spirit.
Mentor as maestro – van mineur na majeur: Die rol van oordrag tussen mentor en mentee
Authors: Nel Johan
Published: December 2011

Mentor as maestro – from minor to major: The role of transfer between mentor and mentee This article takes a glance at the role played by a mentor. The emphasis is on the authentic mentoring process. The metaphor of music is used to illustrate the different keys in which people experience life at large. The hypothesis poses that the transgression takes place during the interaction between the mentor and mentee. As in music, lives can be modulated into another, major key, which may lead to a life of abundance.
Case Report: Acute tuberculous laryngitis presenting as acute epiglottitis
Authors: El Beltagi Ahmed H , Khera Pushpinder S , Alrabiah Lamya , Al Shammari Noufa FJ
Published: December 2011

The incidence of laryngeal tuberculosis (TB), which had dropped dramatically after the institution of modern anti-TB chemotherapy, has shown recent reemergence. It is important to be aware of its possibility, especially as it can present with nonspecific upper airway symptoms and a frequent lack of constitutional manifestations. We report such a case presenting as acute epiglottitis, with diffuse involvement of the supraglottic larynx associated with reactivation lung TB.
ADVANCEMENTS IN EPDM SPONGE COMPOUND PROCESSING USING EPDM BIMODAL POLYMERS
Authors: Jacob Sunny , Jourdain Eric P.
Published: December 2011

Ethylene-propylene-diene (EPDM) elastomers are the primary polymer choice for automotive weatherseal applications due to their outstanding weathering and heat resistance properties. Automotive sealing systems are complex in design; in particular, door seals are one of the most complex components of the sealing system, generally consisting of a low-density sponge profile co-extruded onto a dense metal carrier, as attachment to the car body. Door (or weather) seals contribute to the comfort inside the car by providing insulation from water, vibration, and aerodynamic noises. The geometry of the sponge profile has become increasingly complex over the years to improve overall sealing performance. It controls the door closing force, assessed by load deflection measurements, and the long-term sealing performance, assessed through up to 1000 hours of compression set testing. In the last decade, the use of bimodal EPDM grades for the production of sponge profiles has grown significantly and contributed to increased productivity for door sealing systems. The recent advances in compound mixing and sponge extrusion using bimodal EPDM polymers will be reviewed. It will also be illustrated that such techniques can provide overall cost reduction and production efficiency without adverse effect on essential OEM requirements such as surface aspect, mechanical properties, compression load deflection and permanent set.
Retrospective Validation of New Simulation Software to Prevent Perioperative Hypothermia in Major Urologic Abdominal Surgery
Authors: Bräuer Anselm , Gassner Sebastian , Koch Jochim , Heise Daniel , Quintel Michael
Published: December 2011

Background. Perioperative hypothermia is still a major problem. Therefore, it would be useful to predict which warming method would prevent perioperative hypothermia in a particular patient. Methods. The simulation software “ThermoSim Vers. 5.07” was validated using the data of two prospective, randomized, and controlled studies. The diagnostic effectiveness was assessed by calculating sensitivity and specificity, positive predictive value (PPV), and negative predictive value (NPV) in the detection of perioperative hypothermia. Results. Sensitivity of the software was 100% (Study 1) and 94% (Study 2), specificity was 67% (Study 1) and 38% (Study 2), PPV was 60% (Study 1) and 50% (Study 2), and NPV was 100% (Study 1) and 90% (Study 2). Conclusions. The software is helpful in predicting which warming method is necessary to prevent perioperative hypothermia. Thermal treatment based on the prediction of the software will lead to some overtreatment, but will prevent perioperative hypothermia reliably.
Development of Pancreatic Ductal Adenocarcinoma Associated with Intraductal Papillary Mucinous Neoplasia
Authors: Inui Kazuo , Yoshino Junji , Miyoshi Hironao , Kobayashi Takashi , Yamamoto Satoshi
Published: December 2011

We retrospectively investigated the incidence of pancreatic ductal adenocarcinoma among patients with intraductal papillary mucinous neoplasms of the pancreas. Based on imaging in 195 such patients, we chose surgery as initial treatment for 54, and periodic evaluation over 6 to 192 months (mean, 52) for 141. In 6 of the 141 patients observed for intraductal papillary mucinous neoplasm (4.2%), pancreatic ductal adenocarcinoma developed. Further, careful monitoring for cancer occurrence in the remnant pancreas proved essential in the surgical resection group; 2 of 26 patients (7.7%) subsequently developed pancreatic ductal adenocarcinoma in the remnant pancreas, at 41 months and 137 months after surgery. Serial observation of patients with intraductal papillary mucinous neoplasms by contrast-enhanced computed tomography or magnetic resonance cholangiopancreatography therefore is critical, whether or not surgical treatment initially was performed.
Enhancing Light Emission of Nanostructured Vertical Light‐Emitting Diodes by Minimizing Total Internal Reflection
Authors: Ye Byeong‐Uk , Kim Buem Joon , Song Yang Hee , Son Jun Ho , Yu Hak ki , Kim Myung Hwa , Lee Jong‐Lam , Baik Jeong Min
Published: December 2011

Nanostructured vertical light‐emitting diodes (V‐LEDs) with a very dense forest of vertically aligned ZnO nanowires on the surface of N‐face n‐type GaN are reported with a dramatic improvement in light extraction efficiency (∼3.0×). The structural transformation (i.e., dissociation of the surface nitrogen atoms) at the nanolevel by the UV radiation and Ozone treatments contributes significantly to the initial nucleation for the nanowires growth due to the interdiffusion of Zn into GaN, evident by the scanning photoemission microscopy (SPEM), high‐resolution transmission electron microscopy (HR‐TEM), and ultraviolet photoelectron spectroscopy (UPS) measurements. This enables the growth of densely aligned ZnO nanowires on N‐face n‐type GaN. This approach shows an extreme enhancement in light extraction efficiency (>2.8×) compared to flat V‐LEDs, in good agreement with the simulation expectations (∼3.01×) obtained from 3D finite‐difference time‐domain (FDTD) tools, explained by the wave‐guiding effect. The further increase (∼30%) in light extraction efficiency is also observed by optimized design of nanogeometry (i.e., MgO layer on ZnO nanorods).
Highly Efficient, Irreversible and Selective Ion Exchange Property of Layered Titanate Nanostructures
Authors: Li Nian , Zhang Lide , Chen Yongzhou , Fang Ming , Zhang Junxi , Wang Huimin
Published: December 2011

Layered titanates (Na2Ti3O7·nH2O) with exchangeable sodium cations located in the interlayer have been synthesized by simple hydrothermal treatment of Ti precursor in concentrated NaOH solutions. By proper control of the synthesis conditions, different morphologies of nanofibers and nanosheets are obtained. The metastable layered structure of the titanates collapses during the ion exchange, resulting in irreversible ion exchange. Target cations (eg., Ag+, Cu2+, Pb2+ and Eu3+) are completely concentrated from water and then tightly immobilized in the interlayer which is of great significance for the removal and subsequent safe disposal of hazardous metal cations. The ion exchange of the nanosheets is much more efficient than that of the nanofibers and other inorganic ion exchangers due to the larger surface area, less stable layered structure and larger amount of interlayer water of the nanosheets. The ion exchange of the titanates is also very selective. Valence, hardness, and radius of cations are main factors affecting the selectivity. Cations trapped in the interlayer are released by an acid‐induced phase transformation of the titanate nanosheets to rutile. Then the rutile can be used as a new Ti precursor to synthesize the titanate nanostructures, resulting in a full cycle of material use. The nanosheets may find applications in the decontamination and safe disposal of radioactive and heavy metal cations and also in the collection of valuable cations from water.
Encapsulating Elastically Stretchable Neural Interfaces: Yield, Resolution, and Recording/Stimulation of Neural Activity
Authors: Graudejus Oliver , Morrison Barclay , Goletiani Cezar , Yu Zhe , Wagner Sigurd
Published: December 2011

A high‐resolution elastically stretchable microelectrode array (SMEA) for interfacing with neural tissue is described. The SMEA consists of an elastomeric substrate, such as poly(dimethylsiloxane) (PDMS), elastically stretchable gold conductors, and an electrically insulating encapsulating layer in which contact holes are opened. We demonstrate the feasibility of producing contact holes with 40 μm × 40 μm openings, show why the adhesion of the encapsulation layer to the substrate is weakened during contact hole fabrication, and provide remedies. These improvements result in greatly increased fabrication yield and reproducibility. An SMEA with 28 microelectrodes was fabricated. The contact holes (100 μm × 100 μm) in the encapsulation layer are only ∼10% the size of the previous generation, allowing a larger number of microelectrodes per unit area, thus affording the capability to interface with a smaller neural population per electrode. This new SMEA is used to record spontaneous and evoked activity in organotypic hippocampal tissue slices at 0% strain before stretching, at 5% and 10% equibiaxial strain, and again at 0% strain after relaxation. Stimulus–response curves at each strain level are measured. The SMEA shows excellent biocompatibility for at least two weeks.
Rasta Resin–PPh3–NBniPr2 and its Use in One‐Pot Wittig Reaction Cascades
Authors: Teng Yan , Lu Jinni , Toy Patrick H.
Published: December 2011

A new triarylphosphine–tertiary amine bifunctional polymeric reagent has been prepared and used effectively in a variety of one‐pot Wittig reactions. The design of this reagent resolved a deficiency of a previously reported related material, and allowed it to perform more efficiently in such reactions. Furthermore, it was readily recyclable, and was also successfully applied in cascade processes involving one‐pot Wittig reactions followed by either a conjugate reduction or a reductive aldol reaction. In these reaction cascades, the phosphine oxide groups generated in the Wittig reaction served as the catalyst for the subsequent reaction.
Injection of paraoxonase 1 (PON1) to mice stimulates their HDL and macrophage antiatherogenicity
Authors: Rosenblat Mira , Volkova Nina , Aviram Michael
Published: December 2011

We analyzed, for the first time, the effects of recombinant PON1 (rePON1) intraperitoneal injection to C57BL/6 mice on their HDL and macrophage antiatherogenic properties. Thioglycolate‐treated mice were injected with either saline (Control), or rePON1 (50 μg/mouse), and 20 H post injection, their blood samples and peritoneal macrophages (MPM) were collected. A significant increase in serum and HDL‐PON1 arylesterase and lactonase activities was noted. Similarly, a significant increment, by 3.8 and 2.8 fold, in MPM‐PON1 arylesterase and lactonase activities, respectively, as compared to the activities in control MPM was observed. The HDL from rePON1‐injected mice was resistant to oxidation by copper ions as compared to control HDL. Furthermore, enrichment of the mouse HDL with rePON1 increased its ability to induce cholesterol efflux from J774A.1 macrophage cell line, and to inhibit macrophage‐mediated LDL oxidation. In MPM from rePON1‐injected mice vs. control MPM, there was a significant reduction in cholesterol mass, by 42%, in association with inhibition in cellular cholesterol biosynthesis rate, by 33%, and with significant stimulation, by 65%, of human HDL‐mediated cholesterol efflux from the cells. We conclude that rePON1 injection to mice improved the mice HDL and MPM antiatherogenic properties, and these effects could probably lead to attenuation of atherosclerosis development.
Terpenoids from Maytenus Species and Assessment of Their Reversal Activity against a Multidrug‐Resistant Leishmania tropica Line
Authors: Kennedy María L. , Llanos Gabriel G. , Castanys Santiago , Gamarro Francisco , Bazzocchi Isabel L. , Jiménez Ignacio A.
Published: December 2011

The phytochemical analysis of the root bark extracts of the Chilean Maytenus, M. chubutensis, and M. magellanica (Celastraceae), led to the isolation of one phenolic nortriterpene, 1, and one diterpene with a nor‐ent‐kaurene skeleton, 2. In addition, four known compounds were isolated, among which compound 3 has been isolated for the first time from a natural source. Their structures were elucidated by spectroscopic methods, including 1D‐ and 2D‐NMR (COSY, ROESY, HSQC, and HMBC) experiments, comparison with data reported in the literature, and chemical correlations. The isolated compounds were assayed for their reversal activity against a multidrug‐resistant Leishmania tropica line, overexpressing a P‐glycoprotein related transporter. Compound 1 showed moderate multidrug‐resistance reversal activity.
Electrolysis of Water in the Diffusion Layer: First‐Principles Molecular Dynamics Simulation
Authors: Hofbauer Florian , Frank Irmgard
Published: December 2011

With Car–Parrinello molecular dynamics simulations the elementary reaction steps of the electrolysis of bulk water are investigated. To simulate the reactions occurring near the anode and near the cathode, electrons are removed or added, respectively. The study focuses on the reactions in pure water. Effects depending on a particular electrode surface or a particular electrolyte are ignored. Under anodic conditions, the reaction continues till molecular oxygen is formed, under cathodic conditions the formation of molecular hydrogen is observed. In addition the formation of hydrogen peroxide is observed as an intermediate of the anodic reaction. The simulations demonstrate that the electrochemistry of oxygen formation without direct electrode contact can be explained by radical reactions in a solvent. These reactions may involve the intermediate formation of ions. The hydrogen formation is governed by rapid proton transfers between water molecules.
Modelling Zwitterions in Solution: 3‐Fluoro‐γ‐aminobutyric Acid (3F‐GABA)
Authors: Cao Jie , Bjornsson Ragnar , Bühl Michael , Thiel Walter , van Mourik Tanja
Published: December 2011

The conformations and relative stabilities of folded and extended 3‐fluoro‐γ‐aminobutyric acid (3F‐GABA) conformers were studied using explicit solvation models. Geometry optimisations in the gas phase with one or two explicit water molecules favour folded and neutral structures containing intramolecular NH⋅⋅⋅O‐C hydrogen bonds. With three or five explicit water molecules zwitterionic minima are obtained, with folded structures being preferred over extended conformers. The stability of folded versus extended zwitterionic conformers increases on going from a PCM continuum solvation model to the microsolvated complexes, though extended structures become less disfavoured with the inclusion of more water molecules. Full explicit solvation was studied with a hybrid quantum‐mechanical/molecular‐mechanical (QM/MM) scheme and molecular dynamics simulations, including more than 6000 TIP3P water molecules. According to free energies obtained from thermodynamic integration at the PM3/MM level and corrected for B3LYP/MM total energies, the fully extended conformer is more stable than folded ones by about −4.5 kJ mol−1. B3LYP‐computed 3J(F,H) NMR spin–spin coupling constants, averaged over PM3/MM‐MD trajectories, agree best with experiment for this fully extended form, in accordance with the original NMR analysis. The seeming discrepancy between static PCM calculations and experiment noted previously is now resolved. That the inexpensive semiempirical PM3 method performs so well for this archetypical zwitterion is encouraging for further QM/MM studies of biomolecular systems.
Three‐Dimensional Porous Metal–Radical Frameworks Based on Triphenylmethyl Radicals
Authors: Datcu Angela , Roques Nans , Jubera Véronique , Maspoch Daniel , Fontrodona Xavier , Wurst Klaus , Imaz Inhar , Mouchaham Georges , Sutter Jean‐Pascal , Rovira Concepció , Veciana Jaume
Published: December 2011

Lanthanide coordination polymers {[Ln(PTMTC)(EtOH)2H2O]⋅x H2O, y EtOH} [Ln=Tb (1), Gd (2), and Eu (3)] and {[Ln(αHPTMTC)(EtOH)2H2O]⋅x H2O, y EtOH} [Ln=Tb (1′), Gd (2′), and Eu (3′)] have been prepared by reacting LnIII ions with tricarboxylate‐perchlorotriphenylmethyl/methane ligands that have a radical (PTMTC3−) or closed‐shell (αHPTMTC3−) character, respectively. X‐ray diffraction analyses reveal 3D architectures that combine helical 1D channels and a fairly rare (6,3) connectivity described with the (42.8)⋅(44.62.85.104) Schäfli symbol. Such 3D architectures make these polymers porous solids upon departure of the non‐coordinated guest‐solvent molecules as confirmed by the XRD structure of the guest‐free [Tb(PTMTC)(EtOH)2H2O] and [Tb(αHPTMTC)(EtOH)2H2O] materials. Accessible voids represent 40 % of the cell volume. Metal‐centered luminescence was observed in TbIII and EuIII coordination polymers 1′ and 3′, although the LnIII‐ion luminescence was quenched when radical ligands were involved. The magnetic properties of all these compounds were investigated, and the nature of the {Ln–radical} (in 1 and 2) and the {radical–radical} exchange interactions (in 3) were assessed by comparing the behaviors for the radical‐based coordination polymers 1–3 with those of the compounds with the diamagnetic ligand set. Whilst antiferromagnetic {radical–radical} interactions were found in 3, ferromagnetic {Ln–radical} interactions propagated in the 3D architectures of 1 and 2.
A Microporous Metal–Organic Framework for Highly Selective Separation of Acetylene, Ethylene, and Ethane from Methane at Room Temperature
Authors: He Yabing , Zhang Zhangjing , Xiang Shengchang , Fronczek Frank R. , Krishna Rajamani , Chen Banglin
Published: December 2011

A novel three‐dimensional microporous metal–organic framework Zn4L(DMA)4 (UTSA‐33, H8L=1,2,4,5‐tetra(5‐isophthalic acid)benzene, DMA=N,N′‐dimethylacetamide) with small pores of about 4.8 to 6.5 Å was synthesized and structurally characterized as a non‐interpenetrated (4,8)‐connected network with the flu topology (Schläfli symbol: (41261284)(46)2). The activated UTSA‐33 a exhibits highly selective separation of acetylene, ethylene, and ethane from methane with the adsorption selectivities of 12 to 20 at 296 K, which has been established exclusively by the sorption isotherms and simulated breakthrough experiments, thus methane can be readily separated from their binary and even ternary mixtures at room temperature.
Solid‐Supported Gallium Triflate: An Efficient Catalyst for the Three‐Component Ketonic Strecker Reaction
Authors: Wiles Charlotte , Watts Paul
Published: December 2011

In light of the growing interest in the use of rare earth metal triflates as water‐tolerant Lewis acid catalysts, we embarked upon the development of a solid‐supported gallium triflate (PS‐Ga(OTf)2) derivative as a means of increasing the cleanliness and cost effectiveness of using these increasingly expensive catalytic materials in synthetic processes. Having previously highlighted the advantages associated with coupling solid‐supported catalysis and the emerging area of micro‐reaction technology, we screened PS‐Ga(OTf)2 for activity towards the ketonic Strecker reaction, in which the target α‐aminonitriles were obtained in higher yield and purity compared to reactions reported in literature, in which the analogous homogeneous catalyst was used.
Unprecedented Bidentate Coordination of the Uranyl Cation by the Chromate Anion in the Structure of [(CH3)2CHNH3]2[UO2(CrO4)2]
Authors: Siidra Oleg I. , Nazarchuk Evgeny V. , Krivovichev Sergey V.
Published: December 2011

[(CH3)2CHNH3]2[UO2(CrO4)2] is the first uranyl chromate with a bidentate coordination mode between the uranyl and chromate ions. Although this type of coordination is typical for sulfates, it has not been previously observed for other group VI elements. Statistical analysis of the bidentate coordination geometry parameters in uranyl compounds is given.
Photolytic Release of Butyric Acid from Oxygen‐ and Nitrogen‐Based Heteroaromatic Cages
Authors: Soares Ana M. S. , Piloto Ana M. , Hungerford Graham , Costa Susana P. G. , Gonçalves M. Sameiro T.
Published: December 2011

In order to develop butyric acid photoactive prodrugs, new heteroaromatic conjugates based on oxygen and nitrogen were synthesised and evaluated under irradiation at 254, 300, 350 and 419 nm. Light‐triggered uncaging of butyric acid from the corresponding heterocyclic cages was achieved with complete release of the drug in short times. Naphtho[2,3‐d]oxazole, naphtho[1,2‐d]oxazole, 3‐oxo‐3H‐benzo[f]benzopyran, 2‐oxo‐2H‐benzo[h]benzopyran and 6‐oxo‐6H‐benzopyrano[6,7‐d]oxazole conjugates were readily photolysed, and the best results were obtained for naphtho‐oxazoles at 254 and 300 nm and for 3‐oxo‐3H‐benzo[f]benzopyran, 2‐oxo‐2H‐benzo[h]benzopyran and 2‐methyl‐6‐oxo‐6H‐benzopyrano[6,7‐d]oxazole at 350 nm. 3‐Oxo‐3H‐benzo[f]benzopyran also afforded good results at 419 nm. The photophysical processes involved were further elucidated by the use of time‐resolved fluorescence techniques.
ETV6 rearrangements are recurrent in myeloid malignancies and are frequently associated with other genetic events
Authors: Haferlach Claudia , Bacher Ulrike , Schnittger Susanne , Alpermann Tamara , Zenger Melanie , Kern Wolfgang , Haferlach Torsten
Published: December 2011

ETV6 (TEL) rearrangements are favorable in pediatric acute lymphoblastic leukemia but are less well characterized in myeloid malignancies. We investigated 9,550 patients with myeloid disorders for ETV6 rearrangements by chromosome banding analysis and interphase fluorescence in situ hybridization. ETV6 rearrangements were identified in 51 of 9,550 (0.5%) patients (range, 19.2–85.3 years). Frequencies were in detail: acute myeloid leukemia (AML): 40 of 3,798, 1.1%; myelodysplastic syndromes (MDS): 6 of 3,375, 0.2%; myeloproliferative neoplasms (MPNs): 5 of 1,720, 0.3%; MDS/MPN: 0 of 210; and chronic myelomonocytic leukemia: 0 of 447. Thirty‐three different partner bands of ETV6 were identified, and most were recurrent: 3q26 (n = 10), 5q33 (n = 4), 17q11 (n = 3), 22q12 (n = 3), 5q31 (n = 2), and 2q31 (n = 2). Additional chromosomal abnormalities were identified in 29 of 51 (57%) ETV6 rearranged cases. In AML, ETV6 rearrangements were frequently associated with NPM1 (9/39, 23%) and RUNX1 mutations (6/31, 19%). The FAB M0 subtype was more frequent in ETV6 rearranged de novo AML than other AML (P < 0.001); expression of CD7 and CD34 by immunophenotyping was higher in ETV6 rearranged AML compared with other subgroups. Survival of 29 ETV6 rearranged de novo AML was compared with 818 AML from other cytogenetic subgroups. Median overall and event‐free survival of ETV6 rearranged cases was similar to the intermediate‐risk cohort (26.3 vs. 62.2 months and 14.0 vs. 15.4 months) defined according to Medical Research Council criteria. Our study confirms the variety of ETV6 rearrangements in AML, MDS, and MPNs often in association with other genetic events. Prognosis of ETV6 rearranged de novo AML seems to be intermediate, which should be independently confirmed. © 2011 Wiley Periodicals, Inc.
CGH arrays compared for DNA isolated from formalin‐fixed, paraffin‐embedded material
Authors: Krijgsman Oscar , Israeli Danielle , Haan Josien C. , van Essen Hendrik F. , Smeets Serge J. , Eijk Paul P. , M. Steenbergen Renske D. , Kok Klaas , Tejpar Sabine , Meijer Gerrit A. , Ylstra Bauke
Published: December 2011

Formalin‐fixed, paraffin‐embedded (FFPE) archival tissue is an important source of DNA material. The most commonly used technique to identify copy number aberrations from chromosomal DNA in tumorigenesis is array comparative genomic hybridization (aCGH). Although copy number analysis using DNA from FFPE archival tissue is challenging, several research groups have reported high quality and reproducible DNA copy number results using aCGH. Aim of this study is to compare the commercially available aCGH platforms suitable for high‐resolution copy number analysis using FFPE‐derived DNA. Two dual channel aCGH platforms (Agilent and NimbleGen) and a single channel SNP‐based platform (Affymetrix) were evaluated using seven FFPE colon cancer samples, and median absolute deviation (MAD), deflection, signal‐to‐noise ratio, and DNA input requirements were used as quality criteria. Large differences were observed between platforms; Agilent and NimbleGen showed better MAD values (0.13 for both) compared with Affymetrix (0.22). On the contrary, Affymetrix showed a better deflection of 0.94, followed by 0.71 for Agilent and 0.51 for NimbleGen. This resulted in signal‐to‐nose ratios that were comparable between the three commercially available platforms. Interestingly, DNA input amounts from FFPE material lower than recommended still yielded high quality profiles on all platforms. Copy number analysis using DNA derived from FFPE archival material is feasible using all three high‐resolution copy number platforms and shows reproducible results, also with DNA input amounts lower than recommended. © 2011 Wiley Periodicals, Inc.