bluuebunny/crossref_metadata_2025 huggingface dataset:
Association between AMELX polymorphisms and dental caries in Koreans
Authors: Kang SW , Yoon I , Lee HW , Cho J
Published: November 2010

Oral Diseases (2011) 17, 399–406

Objectives:  Dental caries is greatly influenced disease by environmental factors, but recently there are increasing evidences for a genetic component in caries susceptibility. AMELX is the gene coding amelogenin, which is the most important factor for normal enamel development. The aim of this study was to examine the relationship between dental caries and single nucleotide polymorphisms (SNPs) in AMELX.

Subjects and methods:  For this study, we used DNA samples collected from 120 unrelated individuals older than 12 years of age. All of them were examined for their oral and dental status under the WHO recommended criteria, and clinical information such as DMFT and DMFS were evaluated. Individuals whose DMFT and DMFS index lower than 2 were designated ‘very low caries experience’ and higher than 3 were designated ‘higher caries experience’. Genomic DNA was extracted from hair samples, and single nucleotide polymorphisms of AMELX were genotyped. Genotyping of three SNPs (rs17878486, rs5933871, rs5934997, intron) in AMELX gene was determined by direct sequencing and analyzed with SNPStats.

Results:  There were significant associations between rs5933871 and rs5934997 SNP and caries susceptibility in the water fluoridation group.

Conclusions:  These results suggest that SNPs of AMELX might be associated with dental caries susceptibility in Korean population.
Quantitative analysis of masticatory activity during unilateral mastication using muscle fMRI
Authors: Yamaguchi S , Itoh S , Watanabe Y , Tsuboi A , Watanabe M
Published: November 2010

Oral Diseases (2011) 17, 407–413

Objective:  Quantitative analysis of the activities of all masticatory muscles is required to elucidate the mechanism of stomatognathic dysfunction. Electromyography can be used to record the activity of masticatory muscles, but quantification of the overall activity of every masticatory muscle has not been accomplished because of methodological limitations. In this study, we used muscle functional magnetic resonance imaging for simultaneous quantification of the overall activities of the masseter, medial pterygoid and lateral pterygoid muscles during unilateral gum chewing.

Methods:  Seven healthy male volunteers participated in the study. We evaluated changes in the mean proton transverse relaxation time in the bilateral masseter, medial pterygoid and lateral pterygoid muscles before and after unilateral gum chewing, and to quantify the overall activity of these muscles simultaneously during unilateral gum chewing.

Results:  After 5 min of chewing, the activity of the ipsilateral masseter was highest among the six muscles, followed by the ipsilateral medial pterygoid, contralateral lateral pterygoid and contralateral masseter muscles.

Conclusion:  These results affirm the importance of the ipsilateral masseter muscle and quantitatively demonstrate the important contribution of the ipsilateral medial pterygoid and contralateral lateral pterygoid muscles during unilateral mastication.
Sexual Behavior Predictors of Satisfaction in a Chinese Sample
Authors: Tao Peng , Brody Stuart
Published: November 2010

Introduction

Previous multivariate research in Europe found that sexual satisfaction was associated directly with frequency of penile–vaginal intercourse (PVI) but inversely with masturbation and some aspects of non-PVI partnered sex.

Aims

To examine the associations of sexual satisfaction in a sample from the People’s Republic of China, including not only frequencies of various sexual behaviors, but also frequencies of orgasm.

Methods

Chinese industrial workers (N = 158, age over 24 years) completed the sexual satisfaction scale of the Multidimensional Sexuality Questionnaire (MSQ) and a short form of the Marlowe-Crowne social desirability scale, and provided details of the one month frequencies of engaging in, and having an orgasm from, PVI, masturbation, and non-PVI partnered sex.

Main Outcome Measures

Multiple regression prediction of sexual satisfaction from age, social desirability responding, and in separate analyses, frequencies of the sexual behaviors or the corresponding orgasm frequencies.

Results

For men and women, sexual satisfaction was associated with frequency of PVI and of PVI orgasm (the latter for women only), but not other sexual behavior or orgasm frequency. Similar results were obtained for the MSQ satisfaction scale and for a single satisfaction item.

Conclusions

Despite cultural differences (and our smaller, less diverse sample), the positive prediction of satisfaction from only PVI (and in our sample of women, PVI orgasm) frequency—but not other sexual activities—was similar to that in a Swedish sample. Future research might also examine possible occasional avoidance of ejaculation by some Chinese men.
ADOLESCENT ROMANCE AND DELINQUENCY: A FURTHER EXPLORATION OF HIRSCHI'S “COLD AND BRITTLE” RELATIONSHIPS HYPOTHESIS*
Authors: GIORDANO PEGGY C. , LONARDO ROBERT A. , MANNING WENDY D. , LONGMORE MONICA A.
Published: November 2010

Hirschi (1969) argued that delinquent youth tend to form relatively “cold and brittle” relationships with peers, depicting these youths as deficient in their attachments to others. The current analysis explores connections between delinquency and the character of adolescent romantic ties, drawing primarily on the first wave of the Toledo Adolescent Relationships Study and focusing on 957 teens with dating experience. We examine multiple relationship qualities/dynamics to explore both the “cold” and the “brittle” dimensions of Hirschi's hypothesis. Regarding the “cold” assumption, results suggest that delinquency is not related to the perceived importance of the romantic relationship, level of intimate self‐disclosure, or feelings of romantic love, and more delinquent youth actually report more frequent contact with their romantic partners. Analyses focused on two dimensions tapping the “brittle” description, which indicate that although durations of a focal relationship do not differ according to the level of respondent delinquency, more delinquent youths report higher levels of verbal conflict.
Interaction of HIV‐1 Reverse Transcriptase Ribonuclease H with an Acylhydrazone Inhibitor
Authors: Gong Qingguo , Menon Lakshmi , Ilina Tatiana , Miller Lena G. , Ahn Jinwoo , Parniak Michael A. , Ishima Rieko
Published: November 2010

HIV‐1 reverse transcriptase is a bifunctional enzyme, having both DNA polymerase (RNA‐ and DNA‐dependent) and ribonuclease H activities. HIV‐1 reverse transcriptase has been an exceptionally important target for antiretroviral therapeutic development, and nearly half of the current clinically used antiretrovirals target reverse transcriptase DNA polymerase. However, no inhibitors of reverse transcriptase ribonuclease H are on the market or in preclinical development. Several drug‐like small molecule inhibitors of reverse transcriptase ribonuclease H have been described, but little structural information is available about the interactions between reverse transcriptase ribonuclease H and inhibitors that exhibit antiviral activity. In this report, we describe NMR studies of the interaction of a new ribonuclease H inhibitor, BHMP07, with a catalytically active HIV‐1 reverse transcriptase ribonuclease H domain fragment. We carried out solution NMR experiments to identify the interaction interface of BHMP07 with the ribonuclease H domain fragment. Chemical shift changes of backbone amide signals at different BHMP07 concentrations clearly demonstrate that BHMP07 mainly recognizes the substrate handle region in the ribonuclease H fragment. Using ribonuclease H inhibition assays and reverse transcriptase mutants, the binding specificity of BHMP07 was compared with another inhibitor, dihydroxy benzoyl naphthyl hydrazone. Our results provide a structural characterization of the ribonuclease H inhibitor interaction and are likely to be useful for further improvements of the inhibitors.
Axonal Loss and Neurofilament Phosphorylation Changes Accompany Lesion Development and Clinical Progression in Multiple Sclerosis
Authors: Schirmer Lucas , Antel Jack P. , Brück Wolfgang , Stadelmann Christine
Published: November 2010

Neuroaxonal damage and loss are increasingly recognized as disability determining features in multiple sclerosis (MS) pathology. However, little is known about the long‐term sequelae of inflammatory demyelination on neurons and axons.

Spinal cord tissue of 31 MS patients was compared to three amyotrophic lateral sclerosis (ALS) and 10 control subjects. MS lesions were staged according to the density of KiM‐1P positive macrophages and microglia and the presence of myelin basic protein (MBP) positive phagocytes. T cells were quantified in the parenchyma and meninges. Neuroaxonal changes were studied by immunoreactivity (IR) for amyloid precursor protein (APP) and variably phosphorylated neurofilaments (SMI312, SMI31, SMI32).

Little T cell infiltration was still evident in chronic inactive lesions. The loss of SMI32 IR in ventral horn neurons correlated with MS lesion development and disease progression. Similarly, axonal loss in white matter (WM) lesions correlated with disease duration. A selective reduction of axonal phosphorylated neurofilaments (SMI31) was observed in WM lesions. In ALS, the loss of neuronal SMI32 IR was even more pronounced, whereas the relative axonal reduction resembled that found in MS.

Progressive neuroaxonal neurofilament alterations in the context of chronic inflammatory demyelination may reflect changes in neuroaxonal metabolism and result in chronic neuroaxonal dysfunction as a putative substrate of clinical progression.
Effect of Blanching in Water and Sugar Solutions on Texture and Microstructure of Sliced Carrots
Authors: Neri Lilia , Hernando Isabel Hernando , Pérez‐Munuera Isabel , Sacchetti Giampiero , Pittia Paola
Published: November 2010

Abstract:  Thermal processing of vegetables has pronounced effects on the cell structure, often negatively affecting the final textural properties of the product. In order to study the effect of thermal processing and the protective effect of sugars on the tissue, sliced carrots were subjected to blanching treatments under different time and temperature combinations both in water and in 4% sugar solutions made of trehalose or maltose. The influence of these process conditions on mass transfer, texture, and microstructure (Cryo‐scanning electron microscopy) was thus investigated. The total mass loss of all the samples blanched in water was associated to their cook value () except for the overprocessed one (90 °C, 10 min) that showed a total mass change significantly lower due to water uptake. The use of trehalose and maltose in the blanching solution reduced the solute loss while increasing the water loss. Microstructural analysis of the differently blanched carrots showed detachments between adjacent cell walls as well as plasmolysis phenomena as the time and temperature of the thermal treatment were increased. A protective effect of both sugars on cell structures was observed mostly in the sample treated at 90 °C. At macroscopic level, textural changes upon blanching were observed by a penetration test. As blanching time was increased, samples processed at 75 °C showed a hardness increase, while those processed at 90 °C showed a hardness decrease. However, both trehalose and maltose did not exert significant effects on the textural properties of blanched carrots when compared with those blanched in water.

Practical Application:  The results of this study could offer interesting perspectives in the optimization of the heat treatments in order to preserve the quality of semi‐finished processed vegetables. Furthermore, the microstructural analysis is nowadays an important investigation tool that could contribute to a deeper understanding of both the effects of processing and ingredients on the vegetable microstructure and its relationship with the changes occurring on the quality properties at macroscopic level.
Antimicrobial Effectiveness of Bioactive Packaging Materials from Edible Chitosan and Casein Polymers: Assessment on Carrot, Cheese, and Salami
Authors: Moreira Maria del Rosario , Pereda Mariana , Marcovich Norma E. , Roura Sara I.
Published: November 2010

Abstract:  Antimicrobial packaging is one of the most promising active packaging systems for controlling spoilage and pathogenic microorganisms. In this work, the intrinsic antimicrobial properties of chitosan (CH) were combined with the excellent thermoplastic and film‐forming properties of sodium caseinate (SC) to prepare SC/CH film‐forming solutions and films. The antimicrobial effectiveness of SC, CH, and SC/CH coatings on the native microfloras of cheese, salami, and carrots was evaluated. In vitro assays through the test tube assay indicated that the most significant antimicrobial effect was achieved by CH and SC/CH solutions on carrot and cheese native microfloras. SC film‐forming solutions did not exert antimicrobial activity on any of the native microflora studied. SC, CH, and SC/CH films stored in controlled environments showed that the retention of the antimicrobial action was observed until 5‐d storage, at 65% relative humidity in both temperatures (10 °C and 20 °C). In vivo assays were also performed with SC, CH, and SC/CH applied as coatings or wrappers on the 3 food substrates. CH and SC/CH applied at both immersion and wrapper exerted a significant bactericidal action on mesophilic, psychrotrophic, and yeasts and molds counts, showing the 3 microbial populations analyzed a significant reduction (2.0 to 4.5 log CFU/g). An improvement of the bactericidal properties of the CH/SC blend respect to those of the neat CH film is reported. The ionic interaction between both macromolecules enhances its antimicrobial properties.

Practical Application:  The continuous consumer interest in high quality and food safety, combined with environmental concerns has stimulated the development and study of biodegradable coatings that avoid the use of synthetic materials. Among them, edible coatings, obtained from generally recognized as safe (GRAS) materials, have the potential to reduce weight loss, respiration rate, and improve food appearance and integrity. They can be used in combination with other food preservation techniques in order to extend the effectiveness of the food preservation chain. Moreover, antimicrobial films and coatings have innovated the concept of active packaging and have been developed to reduce, inhibit, or delay the growth of microorganisms on the surface of food in contact with the package. The use of antimicrobials packaging films to control the growth of microorganisms in food can have a significant impact on shelf‐life extension and food safety. In addition, antimicrobial films can be prepared by the combination of inherent antimicrobial materials (that is, CH), with good film‐forming protein‐based ones (that is, SC). Therefore, the objective of this work is to study the performance of 2 biodegradable and edible biopolymers and their combination as natural packages for selected food products.
Production of Okara and Soy Protein Concentrates Using Membrane Technology
Authors: Vishwanathan K.H. , Govindaraju K. , Singh Vasudeva , Subramanian R.
Published: November 2010

Abstract:  Microfiltration (MF) membranes with pore sizes of 200 and 450 nm and ultrafiltration (UF) membranes with molecular weight cut off of 50, 100, and 500 kDa were assessed for their ability to eliminate nonprotein substances from okara protein extract in a laboratory cross‐flow membrane system. Both MF and UF improved the protein content of okara extract to a similar extent from approximately 68% to approximately 81% owing to the presence of protein in the feed leading to the formation of dynamic layer controlling the performance rather than the actual pore size of membranes. Although normalized flux in MF‐450 (117 LMH/MPa) was close to UF‐500 (118 LMH/MPa), the latter was selected based on higher average flux (47 LMH) offering the advantage of reduced processing time. Membrane processing of soy extract improved the protein content from 62% to 85% much closer to the target value. However, the final protein content in okara (approximately 80%) did not reach the target value (90%) owing to the greater presence of soluble fibers that were retained by the membrane. Solubility curve of membrane okara protein concentrate (MOPC) showed lower solubility than soy protein concentrate and a commercial isolate in the entire pH range. However, water absorption and fat‐binding capacities of MOPC were either superior or comparable while emulsifying properties were in accordance with its solubility. The results of this study showed that okara protein concentrate (80%) could be produced using membrane technology without loss of any true proteins, thus offering value addition to okara, hitherto underutilized.

Practical Application:  Okara, a byproduct obtained during processing soybean for soymilk, is either underutilized or unutilized in spite of the fact that its protein quality is as good as that of soy milk and tofu. Membrane‐processed protein products have been shown to posses superior functional properties compared to conventionally produced protein products. However, the potential of membrane technology has not been exploited for the recovery of okara protein. Our study showed that protein content of okara extract could be improved from approximately 68% to approximately 81% without losing any true proteins in the process.
Cryptococcus gattii: In Vitro Susceptibility to Photodynamic Inactivation
Authors: Soares Betânia Maria , Alves Orley Araújo , Ferreira Marcus Vinícius Lucas , Amorim José Cláudio Faria , Sousa Gerdal Roberto , de Barros Silveira Lívio , Prates Renato Araújo , Ávila Thiago Vinícius , de Matos Baltazar Ludmila , da Glória de Souza Daniele , Santos Daniel Assis , Modolo Luzia Valentina , Cisalpino Patrícia Silva , Pinotti Marcos
Published: November 2010

Cryptococus gattii is an emergent primary human pathogen that causes meningismus, papilledema, high intracranial pressure and focal involvement of the central nervous system in immunocompetent hosts. Prolonged antifungal therapy is the conventional treatment, but it is highly toxic, selects for resistant strains, contributes to therapy failure and has a poor prognosis. Photodynamic inactivation (PDI) offers a promising possibility for the alternative treatment of cryptococcosis. The aim of this study was to test the effectiveness of toluidine blue O (TBO) and light‐emitting diode (LED) against C. gattii strains with distinct susceptibility profile to antifungal drugs (amphotericin B: 0.015–1.0 μg mL−1; itraconazole: 0.015–2 μg mL−1; fluconazole: 4–64 μg mL−1). Using 25 μm (6.76 μg mL−1) TBO and LED energy density of 54 J cm−2 these fungal isolates presented variable susceptibility to PDI. The production of reactive oxygen species (ROS)/peroxynitrite was determined, and the catalase and peroxidase activities were measured. After PDI, high amounts of ROS/peroxynitrite are produced and higher catalase and peroxidase activities could be correlated with a lower susceptibility of C. gattii isolates to PDI. These results indicate that PDI could be an alternative to C. gattii growth inhibition, even of isolates less susceptible to classical antifungal drugs, also pointing to mechanisms related to their variable susceptibility behavior.
Swimbladder inflation and its implication to the culture of marine finfish larvae
Authors: Woolley Lindsey D. , Qin Jian G.
Published: November 2010

This review examines the initial swimbladder inflation in cultured finfish larvae and the mechanisms controlling body buoyancy and the distribution of larvae during the critical early development stages. The literature suggests that the body buoyancy of larvae affects their distribution in the tank and fish with low buoyancy are likely to sink to the bottom leading to mortality. Initial swimbladder inflation occurs in a finite period of the postlarval stage and a number of biotic and abiotic factors have been associated with preventing inflation during the ‘window’ period. In recent times larval rearing techniques have been advanced, but it is still a challenge to increase the initial swimbladder inflation rates and maintain larval positioning in the water column to reduce mortality. This review shows that various nutritional and abiotic factors can be manipulated in the culture of many finfish species to achieve high rates of swimbladder inflation and reduce deformations and mortality during early larval rearing.
Vascular Closure Devices in Acute Coronary Syndromes: From Arbitrary to a Necessity?
Authors: Dihu Jamil B. , Chadaga Amar R. , Sanborn Timothy A.
Published: November 2010

Vascular closure devices (VCDs) were initially developed to improve access site hemostasis and allow for earlier ambulation in patients undergoing diagnostic catheterization and percutaneous coronary intervention (PCI). Though initially thought to be beneficial, large meta‐analysis has shown conflicting data regarding whether VCDs alter access site bleeding in a variety of clinical settings. One area of particular interest for the adoption of VCDs has been in the setting of acute coronary syndromes (ACS) in which multiple antiplatelet strategies are often employed leading to a high risk of bleeding. Bleeding in ACS has been shown to be a powerful independent predictor of 30‐day mortality. Recently, investigators have reported that VCDs reduce access site bleeding in the setting of ACS. In our review, we use several selected representative clinical trials to provide a historical account for the use of VCDs. We also provide for a review of data as it relates to access site bleeding in ACS along with analysis showing that VCDs may potentially provide for reductions in bleeding and vascular complications in patients with ACS undergoing PCI.
Optimization of a Single-Cell Solid-Oxide Fuel Cell Using Computational Fluid Dynamics
Authors: Sembler William J. , Kumar Sunil
Published: November 2010

To determine the effects of various parameters on the performance of a solid-oxide fuel cell (SOFC), a series of simulations was performed using computational fluid dynamics (CFD). The first step in this process was to create a three-dimensional CFD model of a specific single-cell SOFC for which experimental performance data had been published. The CFD simulation results developed using this baseline model were validated by comparing them to the experimental data. Numerous CFD simulations were then performed with various thermal conditions at the cell’s boundaries and with different fuel and air inlet temperatures. Simulations were also conducted with fuel utilization factors from 30% to 90% and air ratios from 2 to 6. As predicted by theory, conditions that resulted in higher cell temperatures or in lower air and fuel concentrations resulted in lower thermodynamically reversible voltages. However, the higher temperatures also reduced Ohmic losses and, when operating with low to moderate current densities, activation losses, which often caused the voltages actually being produced by the cell to increase. Additional simulations were performed during which air and fuel supply pressures were varied from 1 atm to 15 atm. Although the increased pressure resulted in higher cell voltages, this benefit was significantly reduced or eliminated when air- and fuel-compressor electrical loads were included. CFD simulations were also performed with counterflow, crossflow, and parallel-flow fuel-channel to air-channel configurations and with various flow-channel dimensions. The counterflow arrangement produced cell voltages that were equal to or slightly higher than the other configurations, and it resulted in a differential temperature across the electrolyte that was significantly less than that of the parallel-flow cell and was close to the maximum value in the crossflow cell, which limits stress caused by uneven thermal expansion. The use of wider ribs separating adjacent flow channels reduced the resistance to the electrical current conducted through the ribs. However, it also reduced the area over which incoming fuel and oxygen were in contact with the electrode surfaces and, consequently, impeded diffusion through the electrodes. Reducing flow-channel height reduced electrical resistance but increased the pressure drop within the channels. Plots of voltage versus current density, together with temperature and species distributions, were developed for the various simulations. Using these data, the effect of each change was determined and an optimum cell configuration was established. This process could be used by fuel cell designers to better predict the effect of various changes on fuel cell performance, thereby facilitating the design of more efficient cells.
Time-Optimal Control of Flexible Robots Made Robust Through Wave-Based Feedback
Authors: O’Connor William J. , McKeown David J.
Published: November 2010

This paper presents a new, robust, time-optimal control strategy for flexible manipulators controlled by acceleration-limited actuators. The strategy is designed by combining the well-known, open-loop, time-optimal solution with wave-based feedback control. The time-optimal solution is used to design a new launch wave input to the wave-based controller, allowing it to recreate the time-optimal solution when the system model is exactly known. If modeling errors are present or a real actuator is used, the residual vibrations, which would otherwise arise when using the time-optimal solution alone, are quickly suppressed due to the additional robustness provided by the wave-based controller. A proximal time-optimal response is still achieved. A robustness analysis shows that significant improvements can be achieved using wave-based control in conjunction with the time-optimal solution. The implications and limits are also discussed.
In-Situ Shrinkage Sensor for Injection Molding
Authors: Panchal Rahul R. , Kazmer David O.
Published: November 2010

Dimensional consistency is a critical attribute for injection molded part quality and is highly dependent on the polymer morphology, the thermal expansion, and various processing parameters. The dimensional shrinkage can be estimated by knowing the pressure-volume-temperature behavior of the polymer but with limited accuracy. There are various process monitoring systems available in the market; none of which has the capability of directly monitoring and controlling the real time shrinkage and part dimensions online. With a view to measuring in-mold shrinkage, a button cell type in-mold shrinkage sensor was developed, validated, and compared against the traditional shrinkage prediction and estimation methods. The shrinkage sensor consists of an elastic diaphragm instrumented with strain gages connected in a full bridge circuit. The sensor is placed beneath the movable pin that is protruded into the mold cavity and remains in contact with the sensor diaphragm. The sensor diaphragm is deflected due to the melt pressure acting on the pin into the mold cavity and is retracted back toward its original position as the melt solidifies and shrinks away from the mold cavity wall. The sensor signals acquired during each molding cycle were analyzed to validate the sensor performance in a design of experiments as a function of packing pressure, melt temperature, cooling time, and coolant temperature. The regression results indicate that the shrinkage sensor outperforms cavity pressure transducers and other methods of predicting the in-mold shrinkage. For polypropylene, the shrinkage sensor is able to measure the shrinkage to an average accuracy of 0.01 mm for a molded part with a nominal thickness of 2.5 mm. The coefficient of correlation, R2, between the sensor’s final positions to the final part thickness was 0.921 for the in-mold shrinkage sensor. Other dimension prediction methods had lower correlation coefficients.
Sub-10 nm patterning of gold nanostructures on silicon-nitride membranes for plasmon mapping with electron energy-loss spectroscopy
Authors: Koh Ai Leen , McComb David W. , Maier Stefan A. , Low H. Y. , Yang Joel K. W.
Published: November 2010

Using high-resolution electron-beam lithography and lift-off, Au structures with sub-10 nm dimensions or spacings were fabricated on 30-nm-thick silicon-nitride (SiN) membranes. Fabricating metal nanostructures on electron-transparent SiN membranes permitted their surface plasmon resonances to be measured using electron energy-loss spectroscopy in a scanning transmission electron microscope (STEM). The surface plasmons that were excited by the 300 keV electron beam exhibited spatially and spectrally distinct longitudinal and transverse modes in elongated Au nanostructures. As the plasmonic response of the nanoparticle was dependent on the point of excitation of the STEM beam, a surface plasmon map could be obtained with nanometer resolution for nanostructures with various geometries. This combination of high-resolution lithography and microscopy will facilitate the design and systematic study of plasmonic nanostructures.
Nanofabrication of x-ray zone plates using ultrananocrystalline diamond molds and electroforming
Authors: Wojcik Michael J. , Joshi Vishwanath , Sumant Anirudha V. , Divan Ralu , Ocola Leonidas E. , Lu Ming , Mancini Derrick C.
Published: November 2010

X-ray zone plates are diffractive focusing optics composed of concentric rings of phase-shifting material with a changing period along their radii. Hard x-ray zone plates operate primarily in a range of photon energies from 3 to 30 keV. In order to achieve needed resolution and efficiency, high-aspect-ratio structures are typically patterned and fabricated by gold electroforming into a dielectric mold. Ideally, the molds would be mechanically stable and radiation resistant. Ultrananocrystalline diamond offers a solution with a set of physical properties that suggests that the material can be fabricated to desired requirements. The authors present here the first results for the fabrication of hard x-ray zone plates using an ultrananocrystalline diamond mold for electroforming gold and discuss future developments for creating an optimized focusing optic.
Field induced shape and work function modification for the ZrO/W(100) Schottky cathode
Authors: Liu K. , Schwind G. A. , Swanson L. W. , Campbell J. A.
Published: November 2010

The origin of the frequently observed long and short term current drifts after a change in the extractor voltage for the ZrO/W(100) Schottky cathode has been investigated. It has been found that a reversible, field dependent change in the equilibrium work function and shape of the cathode end form occurs at the typical operating temperature of 1800 K. The shape change results in three distinct geometric end form shapes. Although these end forms have been observed previously [L. W. Swanson and G. A. Schwind, in Handbook of Charged Particle Optics, 2nd ed., edited by J. Orloff (CRC, New York, 2008), Chap. 1, p. 1; S. Fujita, T. R. Wells, W. Ushio, H. Sato, and M. M. El-Gomati, J. Microsc. 235, 215 (2010); M. S. Bronsgeest and P. Kruit, J. Vac. Sci. Technol. B 27, 2524 (2009)], the purpose of this study is to elucidate the operating conditions under which these changes occur and the associated changes in emission properties. Emitters in the radii range 200–900 nm were investigated over the typical current density operating range employed in most electron probe forming systems. A correlation between work function and electric field has been found, which can be explained by a reversible, field induced change in the ZrO equilibrium coverage in the high field region of the emitter, thereby causing a change in the work function. It is believed that these field induced changes in the equilibrium work function and emitter shape at 1800 K explain the short and long term drifts observed after a change in extractor voltage.
Robust estimation of line width roughness parameters
Authors: Patel Kedar , Lahiri Soumendra N. , Spanos Costas J.
Published: November 2010

Estimation of line width roughness (LWR) parameters is necessary for semiconductor process optimization, comparison of next-generation lithography processes as well as device performance simulation. According to previous studies [V. Constantoudis et al., J. Vac. Sci. Technol. B 21, 1019 (2003); J. Vac. Sci. Technol. B 22, 1974 (2004)], a complete description of LWR can be provided by three parameters: root-mean square roughness (σ), correlation length (ξ), and roughness exponent (α). However, the primary challenge in the estimation of the aforementioned LWR parameters is the limited availability of data in the scanning electron micrograph (SEM) image. A typical SEM image consists of 8–20 lines of 300–1500 nm length. It has been recognized that for a given line, in the presence of correlation between line widths at a given separation, the estimate of σ for a finite length of line can be significantly biased. Furthermore, for next-generation lithography (NGL) technologies such as double patterning, the number of lines available to estimate each lithography step is cut in half since alternate lines are produced from different processes. Thus, there is a need for an estimation procedure that performs robustly for arbitrarily shorter and fewer numbers of lines. Using a vectorized block or block of blocks bootstrap technique for dependent data and a weighted least-squares (WLS) fitting procedure, the authors fit a specific form of a variogram model. Block of blocks bootstrap is used to estimate the variance of a variogram, which in turn provides the WLS weights. Additionally, the bootstrap approach also allows us to estimate the error in the estimated LWR parameters, a vital requirement that has not been addressed by any of the previously reported procedures on this subject. The authors’ procedure works even in the presence of some unknown local critical dimension (CD) variation or if there is a systematic difference in CD (by design or otherwise) between the lines. The authors validate their procedure with simulated roughness profiles with deterministic LWR parameters. Lastly, as an application of their procedure, they evaluate actual profiles from a variety of different mainstream NGL processes such as litho-freeze-litho-etch double patterning lithography, self-aligned double patterning, and extreme ultraviolet, as well as alternatives such as directed self-assembly and nanoimprint lithography. It was shown that σ can be overestimated by over two times if local variation is not treated properly.
Mechanism and dynamics of block copolymer directed assembly with density multiplication on chemically patterned surfaces
Authors: Liu Guoliang , Delcambre Sean P. , Stuen Karl O. , Craig Gordon S. W. , de Pablo Juan J. , Nealey Paul F. , Nygård Kim , Satapathy Dillip K. , Bunk Oliver , Solak Harun H.
Published: November 2010

In this work, we used scanning electron microscopy (SEM), in situ coherent small angle x-ray scattering (SAXS), and Monte Carlo molecular simulation to gain insights into the dynamics of block copolymer directed assembly with density multiplication on chemically patterned surfaces. During directed assembly, it was observed with SEM that poly(styrene-block-methyl methacrylate) initially formed discrete polystyrene domains that lacked long-range order at the free surface. After further annealing, the polystyrene domains gradually coalesced into linear domains that were not registered fully with the underlying chemical pattern. The linear domains could be trapped in metastable morphologies. Finally, the linear polystyrene domains formed perpendicular lamellae in full registration with the underlying chemical pattern. It was revealed with SAXS that scattering peaks characteristic of the period of the chemical pattern appeared and disappeared at the early stages of assembly. Finally, the morphological evolution of directed assembly of block copolymer on chemically patterned surfaces was modeled by molecular simulations.
Impact compression behaviors of high-capacity long piles
Authors: So Arthur K.O. , Ng Charles W.W.
Published: November 2010

The Hiley formula underestimates driving resistance of long piles. Methods using affected pile length have been suggested, but have been found to be inapplicable for high-capacity piles. The impact compression behaviors of about 4700 high-capacity H-piles that were 14–80 m long at final set were studied. Measured data revealed that maximum impact forces are very scattered, but their means are independent of the hammer type, ram weight, ram drop, impact velocity, and pile length. Maximum impact compression of pile and affected pile length exist in both long and short piles. The affected pile length in turn is significant to the blow efficiency, hammer constant, and energy transfer ratio. This length is governed by the impact momentum and impact energy, and can be estimated by an energy-based equation. If the affected pile length determined by this equation is substituted into the Hiley formula to back-analyze the driving resistance, predictability of the driving formula can be improved by about 8%. This improvement is significant enough to reduce the number of hammer blows required at very hard driving conditions and reduce pile damage. Furthermore, this proposed equation is simple to use in the field and is more economical compared with stress-wave monitoring techniques.
ENERGY CONTENTS OF A CLASS OF REGULAR BLACK HOLE SOLUTIONS IN TELEPARALLEL GRAVITY
Authors: SHARIF M. , JAWAD ABDUL
Published: November 2010

In this paper, we discuss the energy–momentum problem in the realm of teleparallel gravity. The energy–momentum distribution for a class of regular black holes coupled with a nonlinear electrodynamics source is investigated by using Hamiltonian approach of teleparallel theory. The generalized regular black hole contains two specific parameters α and β (a sort of dipole and quadrupole of nonlinear source) on which the energy distribution depends. It is interesting to mention here that our results exactly coincide with different energy–momentum prescriptions in general relativity.
MAXIMAL DIMENSIONS OF UNIFORM SIERPINSKI FRACTALS
Authors: KAHNG BYUNGIK , DAVIS JEREMY
Published: November 2010

We studied the invariant fractals in convex N-gons given by N identical pure contractions at its vertices with non-overlapping images, which we called uniform Sierpinski fractals. We provided the explicit formulae for the maximal contraction ratio RN, and the maximal Hausdorff dimension hN, for the uniform Sierpinski fractals. We used maximal N-grams and principal crossing points as the main tools.
INVESTIGATING S VELOCITY STRUCTURE OF THE UPPER MANTLE BENEATH WEST INDONESIA USING SEISMOGRAM ANALYSIS OF TWO STRONG SOUTH JAVA EARTHQUAKES IN MALAYSIAN SEISMOLOGICAL NETWORK
Authors: SANTOSA BAGUS JAYA
Published: November 2010

This research investigated the S speed structure in the upper mantle beneath West Indonesia by analyzing the seismogram triggered by the C052606A and C071706B earthquakes in South Java and recorded at the Malaysian seismological network MY. The method used is waveform comparison between the measured seismogram and the synthetic one in the time domain and three Cartesian components simultaneously, instead of travel time data or dispersion curve, which are commonly used by other seismologists. The seismogram comparison was conducted in the same unit and a low-pass filter with 20 mHz corner frequency was applied to both seismograms. Seismogram analysis shows very strong deviations in the arrival times and amplitudes of the Love and Rayleigh surface waveforms. To solve the observed deviation, a correction on the earth structure covering the speed gradient of βh and the value of zero-order coefficients for the βh and βv in the earth upper mantle is required. The research's result shows that the area of East Sumatra and Borneo has negative correction of S speed structure in the upper mantle layers, compared to PREMAN standard earth model. This result is different from other seismological result.
Existence of Positive Bounded Solutions of Semilinear Elliptic Problems
Authors: Toumi Faten
Published: November 2010

This paper is concerned with the existence of bounded positive solution for the semilinear elliptic problem Δu = λp(x)f(u) in Ω subject to some Dirichlet conditions, where Ω is a regular domain in ℝn (n ≥ 3) with compact boundary. The nonlinearity f is nonnegative continuous and the potential p belongs to some Kato class K(Ω). So we prove the existence of a positive continuous solution depending on λ by
the use of a potential theory approach.
Assessment of a Hexapod Surgical System for Robotic Micro-Macro Manipulations in Ocular Surgery
Authors: Bourges Jean-Louis , Hubschman Jean-Pierre , Wilson Jason , Prince Stephen , Tsao Tsu-Chin , Schwartz Steven
Published: November 2010

Purpose: Robotic intraocular microsurgery requires a remote center of motion (RCM) at the site of ocular penetration. We designed and tested the Hexapod Surgical System (HSS), a microrobot mounted on the da Vinci macrorobot for intraocular microsurgery. Material and Methods: Translations and rotations of the HSS were tested for range of motion and stability. Precision and dexterity were assessed by pointing and inserting a coupled probe into holes of various sizes. The stability of a nonmechanical RCM was quantified. HSS functionalities were observed on porcine eyes. Results: The HSS maximal translations were 10 (x and y axes) and 5 cm (z axis). The maximal rotations were 15 and 22° (x and y axes). The precision was within 0.5 mm away from targets in 26/30 tests and maximal in 16/30 tests. The mean translational and rotational stability at the tip of the probe were 1.2 (0.6–1.9) and 1 mm (0–2), respectively. The average dexterity times were 5.2 (4.4–6.5), 7.1 (5.6–10.8) and 12.3 s (7.8–21.7) for 5-, 2- and 1-mm holes, respectively. The RCM was stable (within 0.1 mm). A vitreous cutter coupled to the HSS moved into porcine eyes through a sclerotomy with a stable RCM. Conclusion: The HSS provides an RCM dedicated for intraocular robotic surgery with a high level of precision and dexterity. Although it can be further improved, the micro-macro robotic system is a feasible approach for ocular surgery.
The Status of Thrombophilic Defects and Non-O Blood Group as Risk Factors for Gestational Vascular Complications among Tunisian Women
Authors: Klai Sarra , Fekih-Mrissa Najiba , Rachdi Radhouen , Gritli Nasredine
Published: November 2010

Aims: Our objectives were to assess inherited thrombophilia and non-O blood group for the risk of gestational vascular complications among the Tunisian population. Methods: This study comprised 203 test subjects with adverse pregnancy outcomes including recurrent pregnancy loss, intra-uterine growth retardation, pre-eclampsia and placental abruption. Each subgroup was matched with 100 controls and analyzed separately. All patients were evaluated for factor V Leiden, factor II G20210A mutations and for non-O blood group. Protein S, protein C and antithrombin levels were determined and deficiencies noted. Results: The factor V Leiden mutation, non-O blood group and protein C deficiency had the highest incidences among patients both as a whole and in the 4 subgroups. The factor II G20210A mutation, protein S and antithrombin deficiencies were not statistically significant risk factors. Conclusion: Our results provide evidence for a significant association between the factor V mutation and placental abruption. Furthermore, we found that this and the non-O blood group independently increased the risk for intra-uterine growth retardation in our population.
U83836E Inhibits Retinal Neurodegeneration in Early-Stage Streptozotocin-Induced Diabetic Rats
Authors: Wang Hong , Zheng Zhi , Gong Yuanyuan , Zhu Bijun , Xu Xun
Published: November 2010

Oxidative stress plays a role in the pathogenesis of neurodegeneration in diabetic retinopathy (DR). However, whether an excellent reactive oxygen species scavenger, U83836E, inhibits the neurodegeneration in DR remains uncertain. This study is aimed at clarifying the effects of U83836E on DR. Two weeks after streptozotocin (STZ) injection, diabetic rats and control animals were assigned at random to receive U83836E or vehicle for 2 weeks. Transmission electron microscopy and electroretinography were used to observe the changes in retina ultrastructure and electrophysiological function, respectively; superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels were measured using a spectrometer. STZ-induced diabetic rats showed obvious vacuolation and many swollen mitochondria in the retinal ganglion cells of the retina, and reduced amplitudes of b-waves and oscillatory potentials. Concomitantly, there was a decrease in SOD activity and increase in MDA levels. These changes were inhibited by U83836E. These results suggest that U83836E improves neurodegeneration in DR and possesses a great potential for the treatment of DR.
Normal Enamel. I. Quantitative Polarized Light Study
Authors: Gwinnett A. John
Published: November 2010

SYNOPSIS IN INTERLINGUA

HISTOLOGIA DE ADAMANTE "NORMAL". 1. STUDIO QUANTITATIVE A LUMINE POLAKISATE.—Studios de imbibition esseva executate con sectiones de dentes permanente, primarimente con le objectivo de determinar si o non adamante es capace de imbiber exogene materiales liquide. Tres milles cinque centos valores de birefringentia esseva registrate e recognoscite como generalmente congrue con illos reportate per previe investigatores. Certe sectiones imbibeva medios altere que aqua durante que certes se trovava impenetrabile. Le imbibition poteva esser describite como representante le comportamento de un cribro molecular, ben que illo non resimilava le comportamento de un systema ideal de corpore mixte. Le spatio disponibile al imbibition amontava approximativemente a 0, 2 pro cento del volumine total.
Osteogenic Activity of Odontoblasts in Transplanted Tooth Pulps
Authors: Zussman William V.
Published: November 2010

SYNOPSIS IN INTERLINGUA

ACTIVITATE OSTEOGENIC DE ODONTOBLASTOS IN TRANSPLANTATE PULPA DENTAL.—Intacte pulpa dental ab incisores de rattos adulte esseva transplantate subcutaneemente ad in animales homologe de un a quatro dies de etate con le objectivo de studiar le formation de tissu calcificate per le odontoblastos. Post le transplantation e le restauration de odontoblastos intacte, tanto spiculas de osso compacte como etiam osso spongiose de characteristicas simile a dentina esseva formate. Post 24 dies, le odontoblastos esseva circumferentiate de stratos de iste genere de osso. Odontoblastos que habeva previemente formate dentina comenciava producer osso quando illos esseva non plus in contacto con tissu oral. Formationes cellular simile a immatur structuras dental esseva inducite per le odontoblastos in tissu fibrose de sito adjacente al transplantas.
Comparison of Amounts of Remodeling Activity in Opposite Cortices of Ribs in Children and Adults
Authors: Landeros Oscar , Frost Harold M.
Published: November 2010

SYNOPSIS IN INTERLINGUA

COMPARATION DEL GRADOS DE ACTIVITATE REMODULATORI IN OPPOSITE CORTICES DE COSTAS IN JUVENILES E ADULTOS.—Le "leges osso-structural" de Frost esseva usate in formular predictiones relative al rapiditate del remodulation de specimens standard de costas human in le curso de varie stadios de vita. Si on suppone que le mentionate leges es valide, il seque a base de cognoscite factos de physiologia respiratori que on pote predicer que le metabolismo de osso debe esser plus rapide in juveniles que in adultos, que illo debe esser plus rapide in le cutanee que in le pleural cortice costal de juveniles, e que illo debe tender a esser equal in ambe cortices post le maturation skeletic. Mesurationes histologic de un specimen standard de costa ab 40 subjectos ha confirmate cata-un de ille predictiones.