bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic Stresses Concentrations of SH Wave by Circular Tunnel with Lining
Authors: Zhang Yi Guang , Zhou Chuan Lu , Liu Yi Xian
Published: August 2011

Based on the scattering theory of elastic waves, employing the wave function expansion method, the scattering and the dynamic stresses concentration of SH wave by circular tunnel with lining are investigated. The analytical solution of the problem is derived, and the numerical solution of the dynamic stress concentration factors around the lining is presented. The effects of the shear elasticity of the surrounding rock and the lining, the wave number on the dynamic stress concentration factors are analyzed. Analysis has shown that the shear elasticity of the surrounding rock and the wave number are factors that influence dynamic stress concentration factor, and provide important theoretical foundation for the earthquake evaluation of lining.
Antecedence of Partnership Formation between Buyer and Supplier in Manufacturing Engineering Based on Matching Theory
Authors: Pei Xu Dong
Published: August 2011

Based on the matching theory, the antecedence of partnership formation between Buyer and Supplier in manufacturing engineering is explored. The results show that strategic level matching and operational level matching are positively associated with partnership formation, and cultural level matching moderates effects of strategic level matching and operational level matching on partnership formation.
Genesis Analysis of Common Defects of Reflow Soldering and Research for Solutions
Authors: Peng Yong , Wang Wan Gang , Wang Xiao Ping
Published: August 2011

To guarantee the quality of surface mounting electronic products, this article analyzes the process features of its four working zones, discusses some main factors which influences the soldering quality of reflow soldering, analyzes the common soldering defects and their causes according to the temperature and process features of reflow soldering during the process of reflow soldering like row-up, bridging, wicking and solder balling. By these measurements, appearance frequency of reflow soldering is effectively reduced and quality of surface mounting electronic products is also raised.
Key Parameter Optimization in Wave Soldering
Authors: Wang Wan Gang , Peng Yong , Wang Xiao Ping
Published: August 2011

Wave soldering is mainly used in electronic assembling process of traditional through-hole cartridge printed-circuit board and hybrid packaged process combining surface mounting with through-hole cartridge components. Compared with manual welding, wave soldering has advantages of high productive efficiency, good welding quality and high reliability. Wave soldering process is a complex and systematic project. During the practical productive process, flux coating quantity, preheat temperature of printed board, soldering temperature and time, uphill height of printed board and peak height should be strictly controlled and its process parameter should be comprehensively regulated in order to achieve better soldering quality.
Surface Corrugation and Stacking Misorientation in Multilayers of Graphene on Nickel
Authors: Raineri Vito , Bongiorno Corrado , di Franco Salvatore , Lo Nigro Raffaella , Rimini Emanuele , Giannazzo Filippo
Published: August 2011

Graphene films were grown on thin polycrystalline Ni using a buried amorphous carbon (a-C) layer as C source. Rapid thermal processes (RTP) at temperatures from 600 to 800°C were used to promote C diffusion into Ni and its subsequent segregation on Ni surface, during the sample cool down. RTP at 800°C was the optimal condition for graphene film formation. Micro-Raman spectroscopy showed that the grown film is mostly composed by multilayers of graphene. Atomic force microscopy showed that the film presents peculiar corrugations (wrinkles), isotropically oriented and with heights ranging from from ~1 to ~15 nm. Selected area diffraction by transmission electron microscopy on the MLG membranes shows a rotational disorder between the stacked graphene layers.
Recombination at Oxide Precipitates in Silicon
Authors: Murphy John D. , Bothe Karsten , Krain Rafael , Olmo Massimiliano , Voronkov Vladimir V. , Falster Robert J.
Published: August 2011

Transient and quasi-steady-state photoconductance methods were used to measure minority carrier lifetime in p-type Czochralski silicon processed in very clean conditions to contain oxide precipitates. Precipitation treatments were varied to produce a matrix of samples, which were then characterised by chemical etching and transmission electron microscopy to determine the density and morphology of the precipitates. The lifetime component associated with the precipitates was isolated by preventing or factoring out the effects of other known recombination mechanisms. The lifetime component due to unstrained precipitates could be extremely high (up to ~4.5ms). Recombination at unstrained precipitates was found to be weak, with a capture coefficient of ~8 x 10-8cm3s-1at an injection level equal to half the doping level. Strained precipitates and defects associated with them (dislocations and stacking faults) act as much stronger recombination centres with a capture coefficient of ~3 x 10-6cm3s-1at the same level of injection. The lifetime associated with strained precipitates increases with temperature with a ~0.18eV activation energy over the room temperature to 140°C range. The shape of the injection level dependence of lifetime was similar for all the specimens studied, with the magnitude of the lifetime being dependent on the precipitate density, strain state and temperature, but independent of precipitate size.
Effects of Ultrasonic Cleaning on Carrier Lifetimes and Photovoltage in Monocrystalline Silicon
Authors: Nadtochiy A.B. , Korotchenkov Oleg , Drapalik Markus , Schlosser Viktor
Published: August 2011

Effects of a kHz-frequency ultrasonic cleaning of silicon wafers on free carrier lifetimes and the photovoltage magnitude are addressed. It is found that the initial photovoltage decay, taken before ultrasonic treatments, can be fitted to a double-exponent form, exhibiting the involvement of shorter- and longer time recombination and trapping centers. The decay speeds up remarkably due to the treatment, and the rapid component of the decay grows at the expense of the slow component. It is also found that, before the treatment, the decay time is markedly non-uniform over the wafer surface, implying the existence of distributed sites affecting carrier lifetimes. The cleaning causes an overall smoothening of the lifetime distribution, which is accompanied by the above shortening. A likely explanation of the effects is based on two facts: (i) the cavitating bubbles are capable of locally removing the surface oxide layer affecting the dangling bonds on the bare Si surface, and (ii) the oxygen and hydrogen, decomposed in water at elevated pressures and temperatures occurring inside a cavitating bubble, can micro-precipitate the Si wafer thus affecting the recombination rate.
Transmission Electron Microscopy Investigations of Metal-Impurity-Related Defects in Crystalline Silicon
Authors: Seibt Michael , Saring Philipp , Hahne Philipp , Stolze Linda , Falkenberg M.A. , Rudolf Carsten , Abdelbarey Doaa , Schuhmann Henning
Published: August 2011

This contribution summarizes recent efforts to apply transmission electron microscopy (TEM) techniques to recombination-active extended defects present in a low density. In order to locate individual defects, electron beam induced current (EBIC) is applied in situ in a focused ion beam (FIB) machine combined with a scanning electron microscope. Using this approach defect densities down to about 10cm-2 are accessible while a target accuracy of better than 50nm is achieved. First applications described here include metal impurity related defects in multicrystalline silicon, recombination and charge collection at NiSi2 platelets, internal gettering of copper by NiSi2 precipitates and site-determination of copper atoms in NiSi2.
Time-Resolved Photocurrent Measurements on PbS Nanocrystal Schottky-Contact Photovoltaic Cells
Authors: Rothemund Ralph , Kreuzer Susanne , Fromherz Thomas , Jantsch Wolfgang
Published: August 2011

We fabricated and characterized NIR-active Schottky-contact solar cells with PbS nanocrystals (NCs) as the active medium. The photovoltaic e ffect is due to carrier generation in the PbS NCs as proven by the comparison of the spectrally-resolved external quantum effciency of the devices and absorbance spectra of the PbS NCs. The operative regime is extended well beyond the Si bandgap into the infrared spectral region up to 1500 nm limited by our measurement setup. One sun I-V and time-resolved photocurrent measurements help to identify critical solar cell parameters for the further improvement of PbS NC Schottky-contact solar cells.
Nephrotic Syndrome and Subepithelial Deposits in a Mouse Model of Immune-Mediated Anti-Podocyte Glomerulonephritis
Authors: Meyer-Schwesinger Catherine , Dehde Silke , Klug Philipp , Becker Jan U. , Mathey Sabrina , Arefi Kazem , Balabanov Stefan , Venz Simone , Endlich Karl-Hans , Pekna Marcela , Gessner J. Engelbert , Thaiss Friedrich , Meyer Tobias N.
Published: August 2011

Subepithelial immune complex deposition in glomerular disease causes local inflammation and proteinuria by podocyte disruption. A rat model of membranous nephropathy, the passive Heymann nephritis, suggests that Abs against specific podocyte Ags cause subepithelial deposit formation and podocyte foot process disruption. In this study, we present a mouse model in which a polyclonal sheep anti-mouse podocyte Ab caused subepithelial immune complex formation. Mice developed a nephrotic syndrome with severe edema, proteinuria, hypoalbuminemia, and elevated cholesterol and triglycerides. Development of proteinuria was biphasic: an initial protein loss was followed by a second massive increase of protein loss beginning at approximately day 10. By histology, podocytes were swollen. Electron microscopy revealed 60–80% podocyte foot process effacement and subepithelial deposits, but no disruption of the glomerular basement membrane. Nephrin and synaptopodin staining was severely disrupted, and podocyte number was reduced in anti-podocyte serum-treated mice, indicating severe podocyte damage. Immunohistochemistry detected the injected anti-podocyte Ab exclusively along the glomerular filtration barrier. Immunoelectron microscopy localized the Ab to podocyte foot processes and the glomerular basement membrane. Similarly, immunohistochemistry localized mouse IgG to the subepithelial space. The third complement component (C3) was detected in a linear staining pattern along the glomerular basement membrane and in the mesangial hinge region. However, C3-deficient mice were not protected from podocyte damage, indicating a complement-independent mechanism. Twenty proteins were identified as possible Ags to the sheep anti-podocyte serum by mass spectrometry. Together, these data establish a reproducible model of immune-mediated podocyte injury in mice with subepithelial immune complex formation.
IL-12p35 Subunit Contributes to Autoimmunity by Limiting IL-27–Driven Regulatory Responses
Authors: Vasconcellos Rita , Carter Natalie A. , Rosser Elizabeth C. , Mauri Claudia
Published: August 2011

Contrasting results have emerged from studies performed using IL-12p35−/− mice. Animals lacking the IL-12p35 subunit can either be protected from or develop exacerbated autoimmune diseases, intracellular infections, and delayed-type hypersensitivity responses. In this study, we report that mice lacking the IL-12p35 subunit develop a significantly milder Ag-induced arthritis compared with wild-type (WT) mice. Lack of severe inflammation is accompanied by an increase in the mRNA levels of the Ebi-3 and p28 subunits and increased secretion of IL-27 and IL-10. This anti-inflammatory environment contributed to increased differentiation of regulatory T and B cells with intact suppressive function. Furthermore, IL-12p35−/− mice display reduced numbers of Th17 cells compared with WT arthritic mice. Neutralization of IL-27, but not the systemic administration of IL-12, restored inflammation and Th17 to levels seen in WT mice. The restoration of disease phenotype after anti–IL-27 administration indicates that the IL-12p35 subunit acts as negative regulator of the developing IL-27 response in this model of arthritis.
Short Communication: Successful vitrification of mouse oocytes using the cryotop method with moderate cryoprotectant concentrations
Authors: Habibi Afrooz , Hosseini Ahmad , Farrokhi Naser , Amidi Fardin , Carvalhais Isabel , Chaveiro António , Moreira da Silva Fernando
Published: August 2011

Habibi, A., Hosseini, A., Farrokhi, N., Amidi, F., Carvalhais, I., Chaveiro, A. and Moreira da Silva, F. 2011. Short Communication: Successful vitrification of mouse oocytes using the cryotop method with moderate cryoprotectant concentrations. Can. J. Anim. Sci. 91: 385–388. The response of vitrified mouse MII oocytes in the presence of two concentrations of cryoprotectants [vit1 (15%: 7.5% dimethyl sulfoxide (DMSO)+7.5% ethylene glycol (EG) and vit2 (30%: 15% DMSO+15% EG)] was analyzed to investigate whether reducing cryoprotectant concentrations can affect oocyte survival after cryopreservation by the cryotop method. After thawing the survival, fertilization, cleavage and blastocyst rates were compared with unfrozen oocytes. It can be concluded that 15% cryoprotectant (7.5% DMSO+7.5% EG), instead of the commonly used 30% (15% DMSO+15% EG), could be helpful by moderating the probable toxic effects of vitrification solution in mouse oocyte during vitrification by cryotop.
Vantagens das listas de discussão como fonte de informação pessoal e profissional
Authors: Böhmerwald Paula , Cendón Beatriz Valadares
Published: August 2011

Este artigo aborda as características e funcionalidades das Listas de Discussão, com o objetivo de suprir a falta de material disponível em português sobre o tema e de difundir sua utilização. Mostra os principais comandos de três servidores de listas: Listserv, Listproc e Majordomo; contrasta as Listas de Discussão com os Grupos de Discussão e com os chats; relaciona algumas regras de Netiqueta e apresenta vários exemplos de listas de discussão das áreas de biblioteconomia e ciência da informação.
China's FTAs: Legal Characteristics and Implications
Authors: Wang Guiguo
Published: August 2011

The contemporary world is witnessing an interesting and seemingly contradictory phenomenon. At the same time that globalization continues to develop, the World Trade Organization (WTO), itself a direct result of globalization, can make no progress in the negotiations on its Doha Development Agenda—a perceived further step of globalization. Since deeper integration cannot be achieved at the multilateral level, regional and especially bilateral arrangements for liberalizing trade and investment, most of which are in the form of bilateral free trade agreements (FTAs), have become increasingly common. Notwithstanding their bilateral nature, FTAs are often referred to as regional arrangements (RTAs) since WTO members have an obligation to report such agreements to that multilateral system, where they are reviewed by the Committee on Regional Trade Agreements.
Electromechanical Actuators Based on Graphene and Graphene/Fe3O4 Hybrid Paper
Authors: Liang Jiajie , Huang Yi , Oh Jiyoung , Kozlov Mikhail , Sui Dong , Fang Shaoli , Baughman Ray H. , Ma Yanfeng , Chen Yongsheng
Published: August 2011

Exceptionally high specific surface area, mechanical strength, electrical conductivity, and a special two‐dimensional structure make graphene a highly promising material for electromechanical actuators. Electromechanical actuators are fabricated using flexible graphene‐based paper prepared via a filtration process, and the stroke of these graphene‐based actuators is directly measured during electrochemical double‐layer charge injection. Actuation strain up to 0.064% was obtained for pristine graphene paper in response to an applied potential of –1 V in 1 M NaCl solution. Double‐layer charge injection in graphene sheets is believed to induce actuation strain through a combination of coulombic and quantum‐chemical‐based expansion. To increase electrochemical‐double‐layer capacitance and actuator performance, Fe3O4 nanoparticles were used to partially prevent graphene sheets from restacking and allow the electrolyte ions to infiltrate the resulting magnetic graphene paper more easily. The magnetic graphene paper exhibits actuation strain as large as 0.1% at –1 V applied potential, which is about 56% higher than that of the pristine graphene paper.
Graphene: Piecing it Together
Authors: Rümmeli Mark H. , Rocha Claudia G. , Ortmann Frank , Ibrahim Imad , Sevincli Haldun , Börrnert Felix , Kunstmann Jens , Bachmatiuk Alicja , Pötschke Markus , Shiraishi Masashi , Meyyappan M. , Büchner Bernd , Roche Stephan , Cuniberti Gianaurelio
Published: August 2011

Graphene has a multitude of striking properties that make it an exceedingly attractive material for various applications, many of which will emerge over the next decade. However, one of the most promising applications lie in exploiting its peculiar electronic properties which are governed by its electrons obeying a linear dispersion relation. This leads to the observation of half integer quantum hall effect and the absence of localization. The latter is attractive for graphene‐based field effect transistors. However, if graphene is to be the material for future electronics, then significant hurdles need to be surmounted, namely, it needs to be mass produced in an economically viable manner and be of high crystalline quality with no or virtually no defects or grains boundaries. Moreover, it will need to be processable with atomic precision. Hence, the future of graphene as a material for electronic based devices will depend heavily on our ability to piece graphene together as a single crystal and define its edges with atomic precision. In this progress report, the properties of graphene that make it so attractive as a material for electronics is introduced to the reader. The focus then centers on current synthesis strategies for graphene and their weaknesses in terms of electronics applications are highlighted.
The effects of distal limb segment shortening on locomotor efficiency in sloped terrain: Implications for Neandertal locomotor behavior
Authors: Higgins Ryan W. , Ruff Christopher B.
Published: August 2011

Past studies of human locomotor efficiency focused on movement over flat surfaces and concluded that Neandertals were less efficient than modern humans due to a truncated limb morphology, which may have developed to aid thermoregulation in cold climates. However, it is not clear whether this potential locomotor disadvantage would also exist in nonflat terrain. This issue takes on added importance since Neandertals likely spent a significant proportion of their locomotor schedule on sloped, mountainous terrains in the Eurasian landscape. Here a model is developed that determines the relationship between lower limb segment lengths, terrain slope, excursion angle at the hip, and step length. The model is applied to Neandertal and modern human lower limb reconstructions. In addition, for a further independent test that also allows more climate‐terrain cross comparisons, the same model is applied to bovids living in different terrains and climates. Results indicate that: (1) Neandertals, despite exhibiting shorter lower limbs, would have been able to use similar stride frequencies per speed as longer‐limbed modern humans on sloped terrain, due to their lower crural indices; and (2) shortened distal limb segments are characteristic of bovids that inhabit more rugged terrains, regardless of climate. These results suggest that the shortened distal lower limb segments of Neandertals were not a locomotor disadvantage within more rugged environments.Am J Phys Anthropol, 2011. © 2011 Wiley‐Liss, Inc.
Optimization of (Phenylmethylidene)‐hydantoins as Prostate Cancer Migration Inhibitors: SAR‐Directed Design, Synthesis, and Pharmacophore Modeling
Authors: Mudit Mudit , El Sayed Khalid A.
Published: August 2011

Prostate cancer is one of the most common cancer forms among males of Western countries. Natural products proved to be an unparalleled source of molecular diversity. The 4‐(hydroxyphenylmethylidene)hydantoin (PMH; 1), (5Z)‐5‐(4‐hydroxybenzylidene)imidazolidine‐2,4‐dione, was isolated from the Red Sea sponge Hemimycale arabica, and recently showed junctional complexes stabilization, anti‐invasive, and antimetastatic activities in vitro and in vivo. The related synthetic analogue, (5Z)‐5‐[4‐(ethylsulfanyl)benzylidene]imidazolidine‐2,4‐dione (2), showed several‐fold‐improved in vivo antimetastatic properties against the highly invasive prostate cancer. To further optimize the activity of PMHs, various ligand‐based strategies were used including the extension of the structure, structural simplification, linker extension, and computer‐assisted CoMFA (Comparative Molecular Field Analysis) results. These strategies yielded thirty 2nd‐generation PMHs, designed based on the 1st‐generation PMHs, such as 1 and 2. Wound‐healing assay was selected to evaluate the in vitro anti‐migratory potential of these new PMHs against the PC‐3 cell line. Several active PMHs, including 10, 13, 24, 29, with nearly twelvefold enhancement of activity vs. 2, were identified. Active compounds were then used to build a pharmacophore model using the SYBYL's DIStance COmparison technique (DISCOtech). Active PMHs were also screened for fragment‐based drug likeness using the OSIRIS program, and an overall drug score was also calculated. Interestingly, the overall drug scores of 24 and 29 along with their anti‐migratory activity were significantly greater than those of 1 and 2. In conclusion, PMHs can be the appropriate scaffolds for the urgently needed drug candidates for the control of androgen independent prostate cancer.
Anthracene and Anthraquinone Derivatives from the Stem Bark of Juglans mandshuricaMaxim.
Authors: Lin Hua , Zhang Yu‐Wei , Zheng Li‐Hua , Meng Xiang‐Ying , Bao Yong‐Li , Wu Yin , Yu Chun‐Lei , Huang Yan‐Xin , Li Yu‐Xin
Published: August 2011

One new anthracene derivative, juglanthracenoside A (1), two new anthraquinones, juglanthraquinone A (2) and juglanthraquinone B (3), along with a new naturally occurring anthraquinone, 9,10‐dihydro‐4,8‐dihydroxy‐9,10‐dioxoanthracene‐2‐carboxylic acid (4), have been isolated from the stem bark of Juglans mandshurica. Their structures were established by detailed spectroscopic analysis and comparison of the NMR data with those of related compounds. Compound 1 displayed noticeable antioxidant activity in both 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) and 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS) free radical‐scavenging assays, while compound 4 showed strong cytotoxicity against HepG2, SGC7901, HCT‐8, and A549 cell lines in vitro.
MRI‐guided vascular access with an active visualization needle
Authors: Saikus Christina E. , Ratnayaka Kanishka , Barbash Israel M. , Colyer Jessica H. , Kocaturk Ozgur , Faranesh Anthony Z. , Lederman Robert J.
Published: August 2011

Purpose:

To develop an approach to vascular access under magnetic resonance imaging (MRI), as a component of comprehensive MRI‐guided cardiovascular catheterization and intervention.

Materials and Methods:

We attempted jugular vein access in healthy pigs as a model of “difficult” vascular access. Procedures were performed under real‐time MRI guidance using reduced field of view imaging. We developed an “active” MRI antenna‐needle having an open‐lumen, distinct tip appearance and indicators of depth and trajectory in order to enhance MRI visibility during the procedure. We compared performance of the active needle against an unmodified commercial passively visualized needle, measured by procedure success among operators with different levels of experience.

Results:

MRI‐guided central vein access was feasible using both the active needle and the unmodified passive needle. The active needle required less time (88 vs. 244 sec, P = 0.022) and fewer needle passes (4.5 vs. 9.1, P = 0.028), irrespective of operator experience.

Conclusion:

MRI‐guided access to central veins is feasible in our animal model. When image guidance is necessary for vascular access, performing this component under MRI will allow wholly MRI‐guided catheterization procedures that do not require adjunctive imaging facilities such as x‐ray or ultrasound. The active needle design showed enhanced visibility, as expected. These capabilities may permit more complex catheter‐based cardiovascular interventional procedures enabled by enhanced image guidance. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.
Correlation of phase values with CT hounsfield and R2* values in calcified neurocysticercosis
Authors: Roy B. , Verma S. , Awasthi R. , Rathore R.K. , Venkatesan R. , Yoganathan S.A. , Das J.K. Maria , Prasad K.N. , Gupta R.K.
Published: August 2011

Purpose:

To correlate phase and R2* derived from susceptibility‐weighted magnetic resonance imaging (MRI) with computed tomography‐Hounsfield (CT‐HU) values in calcified neurocysticercosis and to evaluate phase imaging in the assessment of calcified neurocysticercosis.

Materials and Methods:

Thirty‐five patients with 52 calcified lesions underwent both CT and MRI. Phase and R2* were calculated from multi‐echo 3D‐T2‐star‐weighted‐angiography data. MRI and CT data were coregistered using mutual information. Spearman's correlation was performed between quantitative phase and CT‐HU and R2* values. The Mann–Whitney U‐test was used to see differences between CT‐HU and R2* values from corresponding positive and negative phase regions.

Results:

The median values of CT‐HU and R2* from regions with positive and negative phase were found to be 142.10 (range: 41.89–491.75) and 68.5/sec (range: 20–110/sec) and 137.30 (range: 30.83–458.88) and 69/sec (range: 0–110/sec), respectively. There was a significant correlation of positive phase values with corresponding CT‐HU and R2* values. In addition, there was a significant correlation of R2* and CT‐HU with negative phase values.

Conclusion:

We conclude that there is a significant correlation between negative and positive phase with CT‐HU and R2* values, suggesting that the CT hyperdense lesion may have both calcium and other minerals, which can be differentiated using phase imaging. Conventional MRI should include phase imaging to detect calcified neurocysticercosis. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.
Hydrolysis of carboxylate and phosphate esters using monopyridinium oximes in cationic micellar media
Authors: Singh Namrata , Ghosh Kallol K. , Marek Jan , Kuca Kamil
Published: August 2011

The reactions of p‐nitrophenyl acetate (PNPA) with a series of monopyridinium oximes, viz. 2‐PAM (2‐hydroxyiminomethyl‐1‐methylpyridinium iodide), 3‐PAM (3‐hydroxyiminomethyl‐1‐methylpyridinium iodide), and 4‐PAM (4‐hydroxyiminomethyl‐1‐methylpyridinium iodide) have been studied in the presence of cationic surfactants of same hydrophobic chain length (C16) within the concentration range of 0.5–6.0 mM at pH 8.0 under the pseudo‐first‐order condition. The observed rate constant (kobs) increases with increasing surfactant concentration culminating into a maximum, and this has been analyzed in detail following the concepts of micellar catalysis. The structure–activity relationship of the investigated oximes has been discussed, and 2‐PAM was found to be the most reactive among all the three investigated oximes for the cleavage of PNPA. Esterolytic decomposition of p‐nitrophenyldiphenyl phosphate with oximate ions (CHNO−) was followed in cetyltrimethylammonium bromide micelles at pH 9.0, and 4‐PAM was the most reactive oxime for the micellar hydrolysis of phosphate ester. The apparent acid dissociation constants (pKa) of the investigated oximes have been determined spectrophotometrically. © 2011 Wiley Periodicals, Inc. Int J Chem Kinet 43: 569–578, 2011
Evaluation of signal formation in local arterial input function measurements of dynamic susceptibility contrast MRI
Authors: Bleeker Egbert J. W. , Webb Andrew G. , van Walderveen Marianne A. A. , van Buchem Mark A. , van Osch Matthias J. P.
Published: August 2011

Correct arterial input function (AIF) measurements in dynamic susceptibility contrast‐MRI are crucial for quantification of the hemodynamic parameters. Often a single global AIF is selected near a large brain‐feeding artery. Alternatively, local AIF measurements aim for voxel‐specific AIFs from smaller arteries. Because local AIFs are measured higher in the arterial‐tree, it is assumed that these will reflect the true input of the microvasculature much better. However, do the measured local AIFs reflect the true concentration‐time curves of small arteries? To answer this question, in vivo data were used to evaluate local AIF candidates selected based on two different types of angiograms. For interpretation purposes, a 3D numerical model that simulated partial‐volume effects in local AIF measurements was created and the simulated local AIFs were compared to the ground truth. The findings are 2‐fold. First, the in vivo data showed that the shape‐characteristics of local AIFs are similar to the shape‐characteristics of gray matter concentration‐time curves. Second, these findings are supported by the simulations showing broadening of the measured local AIFs compared to the ground truth. These findings are suggesting that local AIF measurements do not necessarily reflect the true concentration‐time curve in small arteries. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.
Automated liver sampling using a gradient dual‐echo Dixon‐based technique
Authors: Bashir Mustafa R. , Dale Brian M. , Merkle Elmar M. , Boll Daniel T.
Published: August 2011

Magnetic resonance spectroscopy of the liver requires input from a physicist or physician at the time of acquisition to insure proper voxel selection, while in multiecho chemical shift imaging, numerous regions of interest must be manually selected in order to ensure analysis of a representative portion of the liver parenchyma. A fully automated technique could improve workflow by selecting representative portions of the liver prior to human analysis. Complete volumes from three‐dimensional gradient dual‐echo acquisitions with two‐point Dixon reconstruction acquired at 1.5 and 3 T were analyzed in 100 subjects, using an automated liver sampling algorithm, based on ratio pairs calculated from signal intensity image data as fat‐only/water‐only and log(in‐phase/opposed‐phase) on a voxel‐by‐voxel basis. Using different gridding variations of the algorithm, the average correct liver volume samples ranged from 527 to 733 mL. The average percentage of sample located within the liver ranged from 95.4 to 97.1%, whereas the average incorrect volume selected was 16.5–35.4 mL (2.9–4.6%). Average run time was 19.7–79.0 s. The algorithm consistently selected large samples of the hepatic parenchyma with small amounts of erroneous extrahepatic sampling, and run times were feasible for execution on an MRI system console during exam acquisition. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.
Automatic segmentation of amyloid plaques in MR images using unsupervised support vector machines
Authors: Iordanescu Gheorghe , Venkatasubramanian Palamadai N. , Wyrwicz Alice M.
Published: August 2011

Deposition of the β‐amyloid peptide (Aβ) is an important pathological hallmark of Alzheimer's disease (AD). However, reliable quantification of amyloid plaques in both human and animal brains remains a challenge. We present here a novel automatic plaque segmentation algorithm based on the intrinsic MR signal characteristics of plaques. This algorithm identifies plaque candidates in MR data by using watershed transform, which extracts regions with low intensities completely surrounded by higher intensity neighbors. These candidates are classified as plaque or nonplaque by an unsupervised learning method using features derived from the MR data intensity. The algorithm performance is validated by comparison with histology. We also demonstrate the algorithm's ability to detect age‐related changes in plaque load ex vivo in amyloid precursor protein (APP) transgenic mice that coexpress five familial AD mutations (5xFAD mice). To our knowledge, this study represents the first quantitative method for characterizing amyloid plaques in MRI data. The proposed method can be used to describe the spatiotemporal progression of amyloid deposition, which is necessary for understanding the evolution of plaque pathology in mouse models of Alzheimer's disease and to evaluate the efficacy of emergent amyloid‐targeting therapies in preclinical trials. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Numerical simulation of the effect of interface friction of a bounding structure on shear deformation in a granular soil
Authors: Ebrahimian Babak , Bauer Erich
Published: August 2011

Recently, the shear behavior of a cohesionless granular strip that is in contact with a very rough surface of a moving bounding structure has been numerically investigated by several authors by using a micropolar hypoplastic continuum model. It was shown that the micropolar boundary conditions assumed along the interface have a strong influence on the deformations within the granular layer. In previous investigations, only interface friction angles for very rough bounding structures were assumed. In contrast, the focus of the present paper is on the influence of the interface roughness on the deformation behavior of the granular strip when the interface friction angle is lower than the peak friction angle of the granular material. In addition to the interface friction angle, particular attention is also paid to the influence of the mean grain diameter, the solid hardness, the initial void ratio, and the vertical stress on the maximum horizontal shear displacement within the granular layer before sliding is started. Copyright © 2011 John Wiley & Sons, Ltd.
Long‐term results in childhood rhabdomyosarcoma: A report from the Italian cooperative study RMS 79
Authors: Bisogno Gianni , Pastore Guido , Perilongo Giorgio , Sotti Guido , Cecchetto Giovanni , Dallorso Sandro , Carli Modesto
Published: August 2011

Background

The results obtained by protocols for children with rhabdomyosarcoma (RMS) have improved in recent decades. Survival curves usually reach a plateau 3 years after the diagnosis, suggesting that long‐term survival can be expected, but late events are known to occur. We analyzed the long‐term results of the RMS 79 protocol to investigate the type and impact of such events.

Procedure

From 1979 to 1987, 163 children with RMS diagnosed at 21 Italian institutions were registered. Each institution was contacted every year to record patients' status after the end of treatment. When patients were lost to follow‐up, their status was checked by inquiring at the Registry Offices of the towns of residence and the cause of death or occurrence of second cancers was investigated by contacting the patients or their family by phone.

Results

Overall, 16 patients had late events, that is, 7 tumor recurrences, 6 second tumors, and 3 deaths due to treatment‐related complications. The overall survival rates dropped from 62.6 at 3 years to 52.8 at 20 years. By multivariate analysis, the characteristics influencing long‐term survival were histology, tumor site and size, and IRS group. Factors predictive of any kind of late event were tumor site and IRS group.

Conclusions

Major late events can significantly affect the long‐term survival of children with RMS. Modern protocols should provide for a much longer follow‐up than is usually considered to confirm the results achieved and enable possible correlations between primary treatment and late events to be investigated. Pediatr Blood Cancer 2012; 58: 872–876. © 2011 Wiley Periodicals, Inc.
Antiobesity Effects of Chinese Black Tea (Pu‐erh Tea) Extract and Gallic Acid
Authors: Oi Yasuyuki , Hou I‐Ching , Fujita Hiroyuki , Yazawa Kazunaga
Published: August 2011

The antiobesity effects of Chinese black tea (Pu‐erh tea) and of gallic acid (GA) were investigated using in vitro and in vivo assays. Chinese black tea extract (BTE) and GA inhibited pancreatic lipase activity in a dose‐dependent manner in vitro; the IC(inhibitory concentration)50 values were 101.6 and 9.2 µg/mL, respectively. Black tea extract (50, 100 mg/kg body weight (b.w.)) and GA (15, 45 mg/kg b.w.) significantly suppressed the elevation of blood triglyceride after oral administration of a corn oil emulsion (8 mL oil/kg b.w.) to male ddY mice. Moreover, the antiobesity effects of BTE and GA were also evaluated in a mouse model of diet‐induced obesity. Female ddY mice were divided into seven groups; normal diet (ND) group, high fat diet (HFD) group, BTE (0.2% and 0.6% of diets) groups, and GA (0.007%, 0.02% and 0.1% of diets) groups; the experimental groups were fed the test diets for 12 weeks. The BTE 0.6% and GA 0.1% groups showed significant suppression of weight gain. The weight of parametrial adipose tissue was strongly correlated with the body weight. These results suggest that GA contributes to the antiobesity effect of BTE as an active constituent by inhibiting pancreatic lipase activity. Copyright © 2011 John Wiley & Sons, Ltd.
On the correlation functions associated with polynomials of the diffusion operator
Authors: Yaremchuk M. , Smith S.
Published: August 2011

Correlation functions (CFs) associated with the inverse background‐error correlations (iBECs) represented by polynomials of the diffusion operator D are obtained analytically for the binomial approximations of the Gaussian BEC and in the general case of a quadratic polynomial of D. The respective analytical expressions for one‐, two‐ and three‐dimensional cases have two tuning parameters, which provide enough freedom in adjusting the CFs' shape to experimental data. The polynomial coefficients of the corresponding iBEC operator are obtained in terms of these tuning parameters and may be useful in the design of the BEC models for variational data assimilation. Published in 2011 by John Wiley & Sons Ltd.
A two‐step watermarking attack using long‐range correlation image restoration
Authors: Taherinia Amir H. , Jamzad Mansour
Published: August 2011

This paper presents an efficient scheme for blind watermark attacking using the concept of matching of the long‐range data. The main idea of the proposed attack is to add plenty of noise to the watermarked image and then try to restore an unwatermarked copy of the noisy image. The aim is to destroy the watermark information without accessing the parameters used during the watermark embedding process. So, it allows our approach to be completely free from any pre‐assumption on the watermarking algorithm or any other parameters that is used during the watermark embedding procedure. Experimental results show the proposed algorithm's superiority over several other traditional watermarking benchmarks such as Stirmark and Optimark. Peak signal‐to‐noise ratio of the watermarked image after applying the proposed attack is more than 45 dB, and the normalized cross‐correlation for the extracted watermark is lower than 0·4, so the watermark is not detectable after our attack. Copyright © 2011 John Wiley & Sons, Ltd.
Nanopatterning of Ferritin Molecules and the Controlled Size Reduction of Their Magnetic Cores
Authors: Martinez Ramsés V. , Chiesa Marco , Garcia Ricardo
Published: August 2011

A nanopatterning method to deposit ferritin proteins with nanoscale accuracy over large areas is reported. Selective deposition is driven by the electrostatic interactions existing between the proteins and nanoscale features. Upon deposition, the protein shell can be removed by heating the patterns in an oxygen atmosphere. This leaves exposed the iron oxide core, which can be further reduced in size by plasma‐etching methods. In this way, the initial ferritin molecules, which have a nominal size of 12 nm, are reduced to 2 nm nanoparticles. Magnetic force measurements confirm the magnetic activity of the as‐deposited and etched nanoparticles.
Brief Report: Chimeric Pigs Produced from Induced Pluripotent Stem Cells Demonstrate Germline Transmission and No Evidence of Tumor Formation in Young Pigs
Authors: West Franklin D. , Uhl Elizabeth W. , Liu Yubing , Stowe Heather , Lu Yangqing , Yu Ping , Gallegos-Cardenas Amalia , Pratt Scott L. , Stice Steven L.
Published: August 2011

The recent development of porcine induced pluripotent stem cells (piPSCs) capable of generating chimeric animals, a feat not previously accomplished with embryonic stem cells or iPSCs in a species outside of rodents, has opened the doors for in-depth study of iPSC tumorigenicity, autologous transplantation, and other key aspects to safely move iPSC therapies to the clinic. The study of iPSC tumorigenicity is critical as previous research in the mouse showed that iPSC-derived chimeras possessed large numbers of tumors, rising significant concerns about the safety of iPSC therapies. Additionally, piPSCs capable of generating germline chimeras could revolutionize the transgenic animal field by enabling complex genetic manipulations (e.g., knockout or knockin of genes) to produce biomedically important large animal models or improve livestock production. In this study, we demonstrate for the first time in a nonrodent species germline transmission of iPSCs with the live birth of a transgenic piglet that possessed genome integration of the human POU5F1 and NANOG genes. In addition, gross and histological examination of necropsied porcine chimeras at 2, 7, and 9 months showed that these animals lacked tumor formation and demonstrated normal development. Tissue samples positive for human POU5F1 DNA showed no C-MYC gene expression, further implicating C-MYC as a cause of tumorigenicity. The development of germline-competent porcine iPSCs that do not produce tumors in young chimeric animals presents an attractive and powerful translational model to study the efficacy and safety of stem cell therapies and perhaps to efficiently produce complex transgenic animals.
Three‐dimensional transperineal ultrasound findings associated with anal incontinence after intrapartum sphincter tears in primiparous women
Authors: Valsky D. V. , Cohen S. M. , Lipschuetz M. , Hochner‐Celnikier D. , Yagel S.
Published: August 2011

Objective

Three‐dimensional transperineal sonography (3D‐TPS) performed in women following third‐ or fourth‐degree intrapartum tears repaired with the overlapping technique demonstrates characteristic signs. The aim of this study was to investigate the correlation of these signs with clinical complaints of incontinence.

Methods

This was a prospective observational study. Sixty primiparous women underwent 3D‐TPS 3–42 (mean, 10.6) months after surgical repair of third‐ or fourth‐degree postpartum sphincter tears with the overlapping technique and were evaluated for clinical degree of incontinence using the St Mark's Incontinence Score (SMIS) questionnaire. The following signs were assessed on 3D‐TPS: interruption of the internal anal sphincter or external anal sphincter, ‘half moon’ sign, changes in the mucosal folds and thickening of the external anal sphincter in the area of sphincter repair. As a comparison group, 27 primiparous women after normal vaginal delivery, without clinically recognized anal sphincter tears, were evaluated similarly, 3–37 (mean, 9.9) months postpartum.

Results

Abnormal sonographic signs were apparent in 35 (58.3%) of 60 women in the study group, and 39 (65%) of 60 had some clinical complaints of incontinence 3–42 months after delivery, most of a mild degree. Higher SMIS results were found in women of the study group than in those of the comparison group (mean (SD) 2.80 (0.481) vs. 1.15 (0.365); P = 0.018). The rates of incontinence were similar between the women in the study group with normal ultrasound findings and the women in the comparison group (9/25 vs. 10/27; relative risk (RR) = 0.97, 95% CI, 0.47–1.97).

Conclusions

Sonographic signs of anal sphincter tear and repair had disappeared at follow‐up examination in almost half of the patients, and therefore this examination should be deferred from the early postpartum period. A substantial proportion of women report some complaint of incontinence after sphincter repair, most of a slight degree. Such complaints are associated with abnormal 3D‐TPS findings at follow up, while in women with a normal 3D‐TPS scan the rate of incontinence complaints is similar to that in women after normal delivery. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
Predicting the filial behaviors of Chinese–Malaysian adolescents from perceived parental investments, filial emotions, and parental warmth and support
Authors: Cheah Charissa S.L. , Bayram Özdemir Sevgi , Leung Christy Y.Y.
Published: August 2011

The present study examined the mediating role of perceived parental warmth and support in predicting Chinese Malaysian adolescents’ filial behaviors from their age, perceived parental investments, and positive filial emotions toward their parents. The effects of these predictors were examined separately for mothers and fathers. Participants included 122 Chinese adolescents (M = 13.14 years; SD = 2.22) in Malaysia. Adolescents’ perceived parental investments, filial emotions, and warmth and support from each parent were positively, and age was negatively associated with their filial behaviors. No gender differences were found. Perceived maternal warmth and support significantly mediated the effect of age, perceived investments from, and filial emotions toward mothers on adolescents’ filial behaviors, but perceived paternal warmth and support did not have a mediating role. The present study sheds light on the unique maternal versus paternal filial role, and important familial processes in Chinese‐Malaysian children and adolescents from a cultural perspective.
The role of intramolecular interactions in the functional control of multiheme cytochromes c
Authors: Fonseca Bruno M. , Paquete Catarina M. , Salgueiro Carlos A. , Louro Ricardo O.
Published: August 2011

Detailed thermodynamic and structural data measured in soluble monomeric multiheme cytochromes c provided the basis to investigate the functional significance of interactions between redox co‐factors. The steep decay of intramolecular interactions with distance means that close proximity of the redox centers is necessary to modulate the intrinsic reduction potentials in a significant way. This ensures selection of specific populations during redox activity in addition to maintaining fast intramolecular electron transfer. Therefore, intramolecular interactions between redox co‐factors play an important role in establishing the biological function of the protein by controlling how electrons flow through and are distributed among the co‐factors.
Coblation for epistaxis management in patients with hereditary haemorrhagic telangiectasia: a multicentre case series
Authors: Joshi H , Woodworth B A , Carney A S
Published: August 2011

Objective:

To propose radiofrequency coblation as a potential treatment modality for mild to moderate epistaxis in patients with hereditary haemorrhagic telangiectasia.

Method:

Case reports and review of the world literature concerning coblation and other treatment modalities for epistaxis in patients with hereditary haemorrhagic telangiectasia.

Results:

Effective epistaxis control was achieved in four out of five cases of hereditary haemorrhagic telangiectasia. In the fifth case, we struggled to achieve haemostasis due to disease severity.

Conclusion:

Radiofrequency coblation is a novel technique, which was found to be a safe, effective, quick and well tolerated treatment option for epistaxis management in patients with hereditary haemorrhagic telangiectasia.