bluuebunny/crossref_metadata_2025 huggingface dataset:
Adaptive backstepping integral control of a small‐scale helicopter for airdrop missions
Authors: Lee Chi‐Tai , Tsai Ching‐Chih
Published: April 2010

This paper presents an adaptive Lyapunov‐based controller with integral action for small‐scale helicopters carrying out airdrop missions. The proposed controller is designed via adaptive backstepping. Unlike the approximate modeling approaches, where the coupling effect of the helicopter is neglected, the proposed method is developed according to a complete dynamic model such that the closed‐loop helicopter system is guaranteed to be globally ultimately bounded. Two numerical simulations with airdrops are conducted to exemplify the merits of the proposed controller. Through simulation results, the proposed control method is shown to outperform the well‐known controller in Mahony and Hamel,Int. J. Robust Nonlinear Control, Vol. 14, No. (12), pp. 1035–1059 (2004).

Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
An updated history of the Teratology Society
Authors: Shepard Thomas H. , Barr Mason , Brent Robert L. , Hendrickx Andrew , Kochhar Devendra , Oakley Godfrey , Scott William J. , Rogers John M.
Published: April 2010

BACKGROUND: The 49‐year history of the Teratology Society is reviewed. An abbreviated history is outlined in table form, with listings of the Warkany Lectures, the Continuing Education Courses, and officers of the society. The original article was updated to include the years 2000 to 2010. METHODS: A year‐by‐year description of the events is given, including the scientific and social content of the annual meetings and changes in the business of the society, in many cases using comments from the past presidents. The valuable and unique diversity of the members is discussed and illustrated, presenting the disciplines and main research areas of the presidents. The number of submitted abstracts and the various categories are tabulated, averaging the number and type over successive periods. A significant increase in the number of abstracts dealing with epidemiology and developmental biology is evident. The society's development is compared to that of a human, and the question was asked by Shephard et al. (2000): Have we reached the maturational stage of old age or senescence, or is the society still maturing gracefully? This question needs further discussion by all the members. By 2010, many positive changes are happening to revitalize the society. RESULTS: During the past 50 years, we have developed the scientific basis to prevent birth defects caused by rubella, alcoholism, and folate deficiency, as well as other prenatal exposures. We are now taking advantage of advances in many fields to begin shaping the Teratology Society of the 21st century. CONCLUSIONS: We must now engage in political battles to obtain the resources needed to conduct further research and to implement prevention programs, as well as to provide care and rehabilitation for persons with birth defects. Birth Defects Research (Part A), 2010. © 2010 Wiley‐Liss, Inc.
LpxA: A natural nanotube
Authors: Das Atanu , Mukhopadhyay Chaitali
Published: April 2010

UDP‐N‐acetylglucosamine 3‐O‐acyltransferase is a protein with a left‐handed parallel β‐helix, which is a natural nanotube. They are associated with unusual high stability. To identify the reason behind the structural stability of β‐helical nanotubular structure, we have performed a total of 4 μs molecular dynamics simulations of the protein in implicit solvent at four different temperatures and monitored the unfolding pathway. The correlation in movement between different regions of the nanotubular structure has been identified from the dynamical cross‐correlation map and contribution of some specific residues towards unfolding transition has been identified by principal component analysis. Difference in stability of the three loop regions has also been characterized. Construction of the unfolding conformational energy landscape identifies the probable intermediates that can appear in the unfolding pathway of the protein. © 2010 Wiley Periodicals, Inc. Biopolymers 93: 845–853, 2010.
Control of misincorporation of serine for asparagine during antibody production using CHO cells
Authors: Khetan Anurag , Huang Yao‐ming , Dolnikova Jana , Pederson Nels E. , Wen Dingyi , Yusuf‐Makagiansar Helena , Chen Paul , Ryll Thomas
Published: April 2010

A recombinant monoclonal antibody produced by Chinese hamster ovary (CHO) cell fed‐batch culture was found to have amino acid sequence misincorporation upon analysis by intact mass and peptide mapping mass spectrometry. A detailed analysis revealed multiple sites for asparagine were being randomly substituted by serine, pointing to mistranslation as the likely source. Results from time‐course analysis of cell culture suggest that misincorporation was occurring midway through the fed‐batch process and was correlated to asparagine reduction to below detectable levels in the culture. Separate shake flask experiments were carried out that confirmed starvation of asparagine and not excess of serine in the medium as the root cause of the phenomenon. Reduction in serine concentration under asparagine starvation conditions helped reduce extent of misincorporation. Supplementation with glutamine also helped reduce extent of misincorporation. Maintenance of asparagine at low levels in 2 L bench‐scale culture via controlled supplementation of asparagine‐containing feed eliminated the occurrence of misincorporation. This strategy was implemented in a clinical manufacturing process and scaled up successfully to the 200 and 2,000 L bioreactor scales. Biotechnol. Bioeng. 2010;107: 116–123. © 2010 Wiley Periodicals, Inc.
Peptide array‐based characterization and design of ZnO‐high affinity peptides
Authors: Okochi Mina , Sugita Tomoya , Furusawa Seiji , Umetsu Mitsuo , Adschiri Tadafumi , Honda Hiroyuki
Published: April 2010

Peptides with both an affinity for ZnO and the ability to generate ZnO nanoparticles have attracted attention for the self‐assembly and templating of nanoscale building blocks under ambient conditions with compositional uniformity. In this study, we have analyzed the specific binding sites of the ZnO‐binding peptide, EAHVMHKVAPRP, which was identified using a phage display peptide library. The peptide binding assay against ZnO nanoparticles was performed using peptides synthesized on a cellulose membrane using the spot method. Using randomized rotation of amino acids in the ZnO‐binding peptide, 125 spot‐synthesized peptides were assayed. The peptide binding activity against ZnO nanoparticles varied greatly. This indicates that ZnO binding does not depend on total hydrophobicity or other physical parameters of these peptides, but rather that ZnO recognizes the specific amino acid alignment of these peptides. In addition, several peptides were found to show higher binding ability compared with that of the original peptides. Identification of important binding sites in the EAHVMHKVAPRP peptide was investigated by shortened, stepwise sequence from both termini. Interestingly, two ZnO‐binding sites were found as 6‐mer peptides: HVMHKV and HKVAPR. The peptides identified by amino acid substitution of HKVAPR were found to show high affinity and specificity for ZnO nanoparticles. Biotechnol. Bioeng. 2010;106: 845–851. © 2010 Wiley Periodicals, Inc.
Effect of zeta potential value on bacterial behavior during electrophoretic separation
Authors: Kłodzińska Ewa , Szumski Michał , Dziubakiewicz Ewelina , Hrynkiewicz Katarzyna , Skwarek Ewa , Janusz Władysław , Buszewski Bogusław
Published: April 2010

The aggregation and/or adhesion of bacterial cells is a serious disadvantage of electrophoretic separations. In this study, physicochemical surface characteristics of bacteria were measured to establish their role in bacterial adhesion and aggregation on the basis of electrophoretic behavior of different clinical strains of Gram‐positive Staphylococcus aureus and Gram‐negative Escherichia coli bacteria. The number and the shape of peaks obtained on the electropherograms were connected with the zeta potential measurements and in‐line microscope observation using specially designed CE fluorescence stereomicroscope setup. These results suggest that the lower the zeta potential, the higher the number of smaller peaks detected. The direct microscopic observation of electrophoretic movement proved the presence of many small aggregates originating from individual or clustered bacterial cells. On the other hand, lower zeta potential was also observed for dead bacterial cells, which suggested that some of the peaks can be attributed to viable cells while the other to the dead ones.
Hippocampal atrophy patterns in mild cognitive impairment and Alzheimer's disease
Authors: Mueller Susanne G. , Schuff Norbert , Yaffe Kristine , Madison Catherine , Miller Bruce , Weiner Michael W.
Published: April 2010

Background:

Histopathological studies and animal models suggest that hippocampal subfields may be differently affected by aging, Alzheimer's disease (AD), and other diseases. High‐resolution images at 4 Tesla depict details of the internal structure of the hippocampus allowing for in vivo volumetry of different subfields. The aims of this study were as follows: (1) to determine patterns of volume loss in hippocampal subfields in normal aging, AD, and amnestic mild cognitive impairment (MCI). (2) To determine if measurements of hippocampal subfields provide advantages over total hippocampal volume for differentiation between groups.

Methods:

Ninety‐one subjects (53 controls (mean age: 69.3 ± 7.3), 20 MCI (mean age: 73.6 ± 7.1), and 18 AD (mean age: 69.1 ± 9.5) were studied with a high‐resolution T2 weighted imaging sequence aimed at the hippocampus. Entorhinal cortex (ERC), subiculum, CA1, CA1‐CA2 transition zone (CA1‐2), CA3 & dentate gyrus (CA3&DG) were manually marked in the anterior third of the hippocampal body. Hippocampal volume was obtained from the Freesurfer and manually edited.

Results:

Compared to controls, AD had smaller volumes of ERC, subiculum, CA1, CA1‐2, and total hippocampal volumes. MCI had smaller CA1‐2 volumes. Discriminant analysis and power analysis showed that CA1‐2 was superior to total hippocampal volume for distinction between controls and MCI.

Conclusion:

The patterns of subfield atrophy in AD and MCI were consistent with patterns of neuronal cell loss/reduced synaptic density described by histopathology. These preliminary findings suggest that hippocampal subfield volumetry might be a better measure for diagnosis of early AD and for detection of other disease effects than measurement of total hippocampus. Hum Brain Mapp, 2010. © 2010 Wiley‐Liss, Inc.
Childhood psychiatric disorders as anomalies in neurodevelopmental trajectories
Authors: Shaw Philip , Gogtay Nitin , Rapoport Judith
Published: April 2010

Childhood psychiatric disorders are rarely static; rather they change over time and longitudinal studies are ideally suited to capture such dynamic processes. Using longitudinal data, insights can be gained into the nature of the perturbation away from the trajectory of typical development in childhood disorders. Thus, some disorders may reflect a delay in neurodevelopmental trajectories. Our studies in children with attention‐deficit/hyperactivity disorder (ADHD) suggest that cortical development is delayed with a rightward shift along the age axis in cortical trajectories, most prominent in prefrontal cortical regions. Other disorders may be characterized by differences in the velocity of trajectories: the basic shape of neurodevelopmental curves remains intact, but with disrupted tempo. Thus, childhood onset schizophrenia is associated with a marked increase during adolescence in the velocity of loss of cerebral gray matter. By contrast, in childhood autism there is an early acceleration of brain growth, which overshoots typical dimensions leading to transient cerebral enlargement. Finally, there may be more profound deviations from typical neurodevelopment, with a complete “derailing” of brain growth and a loss of the features which characterize typical brain development. An example is the almost complete silencing of white matter growth during adolescence of patients with childhood onset schizophrenia. Adopting a longitudinal perspective also readily lends itself to the understanding of the neural bases of differential clinical outcomes. Again taking ADHD as an example, we found that remission is associated with convergence to the template of typical development, whereas persistence is accompanied by progressive divergence away from typical trajectories. Hum Brain Mapp, 2010. © 2010 Wiley‐Liss, Inc.
Neural plasticity of development and learning
Authors: Galván Adriana
Published: April 2010

Development and learning are powerful agents of change across the lifespan that induce robust structural and functional plasticity in neural systems. An unresolved question in developmental cognitive neuroscience is whether development and learning share the same neural mechanisms associated with experience‐related neural plasticity. In this article, I outline the conceptual and practical challenges of this question, review insights gleaned from adult studies, and describe recent strides toward examining this topic across development using neuroimaging methods. I suggest that development and learning are not two completely separate constructs and instead, that they exist on a continuum. While progressive and regressive changes are central to both, the behavioral consequences associated with these changes are closely tied to the existing neural architecture of maturity of the system. Eventually, a deeper, more mechanistic understanding of neural plasticity will shed light on behavioral changes across development and, more broadly, about the underlying neural basis of cognition. Hum Brain Mapp, 2010. © 2010 Wiley‐Liss, Inc.
Cannabis use and mental health problems
Authors: van Ours Jan C. , Williams Jenny
Published: April 2010

This paper investigates whether cannabis use leads to worse mental health. To do so, we account for common unobserved factors affecting mental health and cannabis consumption by modeling mental health jointly with the dynamics of cannabis use. Our main finding is that using cannabis increases the likelihood of mental health problems, with current use having a larger effect than past use. The estimates suggest a dose–response relationship between the frequency of recent cannabis use and the probability of currently experiencing a mental health problem. Copyright © 2010 John Wiley & Sons, Ltd.
From market shares to consumer types: Duality in differentiated product demand estimation
Authors: Kalouptsidi Myrto
Published: April 2010

A widely applied method for differentiated product demand estimation, introduced by Berry, Levinsohn and Pakes in 1995, is founded on matching observed and theoretical market shares of products. In this paper, we allow for discrete consumer tastes and derive an equivalent matching occurring in the consumer type space. The equivalence between the two formulations expresses a duality between market shares and consumer types. In applications where a large number of products and a small number of consumer types is natural, the dual formulation introduced in this paper is computationally more efficient than the primal. Indeed, simulation exercises show that the dual method can be significantly faster. Copyright © 2010 John Wiley & Sons, Ltd.
In vitro cellular responses in the RTG‐2 cell line to complex mixtures of dioxins and dioxin‐like PCDDs, PCDFs and PCBs
Authors: del Mar Babín María , Sanz Paloma , Concejero Miguel Angel , Martínez María Angeles , Tarazona José Vicente
Published: April 2010

High‐resolution gas chromatography/mass spectrometry (HRGC/MS) is the standard method for analysing dioxin, furan and polybrominated retardants in hazardous waste. Determination of dioxin‐like compounds using in vitro bioassays such as ethoxyresorufin‐O‐deethylase (EROD) is an important tool to evaluate their Ah receptor‐mediated toxic effects, because it detects all arylhydrocarbon receptor ligands in a variety of sample matrices. In the present work, we compared RTG‐2 cell line EROD bioassay with HRGC/MS for assessing waste samples (liquid and solid) contaminated with polychlorinated dibenzo‐p‐dioxins and dibenzofurans, polychlorinated biphenyls (dioxin‐like PCBs) and other xenobiotics. For liquid samples, HRGC/MS‐toxic equivalent (HRGC/MS‐TEQ) values ranged from 273.26 to 5.84 ng TEQ l−1 and correlated well (correlation coefficient 0.99) with values obtained by EROD‐TEQ, which ranged from 128 to 2.5 ng TEQ l−1. For solid samples, HRGC/MS‐TEQ values ranged from 3.44 to 0.49 ng TEQ g−1 and correlated less well than liquid samples (correlation coefficient 0.64) with values obtained by EROD‐TEQ ranging from 2.27 to 0.93 ng TEQ g−1. The overestimation of RTG‐2 EROD‐TEQ (1.2 ± 0.92 of values established by HRGC/MS) and the absence of false‐negative results may limit analytical costs by eliminating the need for follow‐up GC/MS analysis on the negative samples. We suggest that RTG‐2 EROD bioassay is an inexpensive means for preliminary dioxin and furan positive screenings of waste samples. Copyright © 2010 John Wiley & Sons, Ltd.
Corrosion resistance and in vitro response of laser‐deposited Ti‐Nb‐Zr‐Ta alloys for orthopedic implant applications
Authors: Samuel Sonia , Nag Soumya , Nasrazadani Seifollah , Ukirde Vaishali , Bouanani Mohamed El , Mohandas Arunesh , Nguyen Kytai , Banerjee Rajarshi
Published: April 2010

While direct metal deposition of metallic powders, via laser deposition, to form near‐net shape orthopedic implants is an upcoming and highly promising technology, the corrosion resistance and biocompatibility of such novel metallic biomaterials is relatively unknown and warrants careful investigation. This article presents the results of some initial studies on the corrosion resistance and in vitro response of laser‐deposited Ti‐Nb‐Zr‐Ta alloys. These new generation beta titanium alloys are promising due to their low elastic modulus as well as due the fact that they comprise of completely biocompatible alloying elements. The results indicate that the corrosion resistance of these laser‐deposited alloys is comparable and in some cases even better than the currently used commercially‐pure (CP) titanium (Grade 2) and Ti‐6Al‐4V ELI alloys. The in vitro studies indicate that the Ti‐Nb‐Zr‐Ta alloys exhibit comparable cell proliferation but enhanced cell differentiation properties as compared with Ti‐6Al‐4V ELI. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.
The cytologic criteria of malignancy
Authors: Fischer Andrew H. , Zhao Chengquan , Li Qing Kay , Gustafson Karen S. , Eltoum Isam‐Eldin , Tambouret Rosemary , Benstein Barbara , Savaloja Lynnette C. , Kulesza Peter
Published: April 2010

Cytology and cell biology are two separate fields that share a focus on cancer. Cancer is still diagnosed based on morphology, and surprisingly little is known about the molecular basis of the defining structural features. Cytology uses the smallest possible biopsy for diagnosis by reducing morphologic “criteria of malignancy” to the smallest scale. To begin to develop common ground, members of the American Society of Cytopathology Cell Biology Liaison Working Group classify some of the “criteria of malignancy” and review their relation to current cell biology concepts. The criteria of malignancy are extremely varied, apparently reflecting many different pathophysiologies in specific microenvironments. Criteria in Group 1 comprise tissue‐level alterations that appear to relate to resistance to anoikis, alterations in cell adhesion molecules, and loss of apical–basal polarity. Criteria in Group 2 reflect genetic instability, including chromosomal and possibly epigenetic instability. Criteria in Groups 3 are subcellular structural changes involving cytoplasmic components, nuclear lamina, chromatin and nucleoli that cannot be accounted for by genetic instability. Some distinct criteria in Group 3 are known to be induced by cancer genes, but their precise structural basis remains obscure. The criteria of malignancy are not closely related to the histogenetic classification of cancers, and they appear to provide an alternative, biologically relevant framework for establishing common ground between cytologists and cell biologists. To understand the criteria of malignancy at a molecular level would improve diagnosis, and likely point to novel cell physiologies that are not encompassed by current cell biology concepts. J. Cell. Biochem. 110: 795–811, 2010. © 2010 Wiley‐Liss, Inc.
Investigating the microbial inactivation efficiency of a 25 L batch solar disinfection (SODIS) reactor enhanced with a compound parabolic collector (CPC) for household use
Authors: Ubomba‐Jaswa Eunice , Fernández‐Ibáñez Pilar , Navntoft Christian , Polo‐López M. Inmaculada , McGuigan Kevin G.
Published: April 2010

BACKGROUND: A simple point‐of‐use solar disinfection (SODIS) reactor was designed to treat 25 L of water and was constructed from a methacrylate tube placed along the linear focus of a compound parabolic concentrator (CPC) and mounted at 37° inclination. Experiments were carried out over a 7 month period by seeding a 106 CFU mL−1 concentration of Escherichia coli K‐12 in 25 L of well water or turbid water to mimic field conditions and determine the microbial effectiveness of the reactor.

RESULTS: During periods of strong sunlight, complete inactivation of bacteria occurred in under 6 h, even with water temperatures < 40 °C. Under cloudy and low solar intensity conditions, prolonged exposure was needed. Turbid water (100 NTU) was disinfected in 7 h with water temperatures > 50 °C. No regrowth of bacteria occurred within 24 h and 48 h following solar disinfection. The construction cost of this prototype reactor was approximately US$ 200 but with an expected lifetime of 10 years, the running cost of the reactor is expected to be US$ 0.002 L−1.

CONCLUSION: This study confirms that significant water disinfection can be achieved using a low cost CPC‐enhanced 25 L batch SODIS reactor. Copyright © 2010 Society of Chemical Industry
Effects of electrolytes on the reduction of 2,4‐dinitrotoluene by zero‐valent iron
Authors: Fan Jin‐Hong , Wang Hong‐Wu , Wu De‐Li , Ma Lu‐Ming
Published: April 2010

BACKGROUND: Dinitrotoluenes (DNTs) are environmentally persistent, making the remediation of contaminated streams and groundwater difficult. Zero‐valent iron (Fe0) can be used as an electron source for the reduction of recalcitrant DNTs in waste‐water and thus enhance their biodegradability. However, little is known about the qualitative effects of major anions and cations present in waste‐water on the reduction of DNTs by Fe0.

RESULTS: The presence of Na2SO4 and NaCl at levels between 0.25 and 2 mmol L−1 was observed to enhance the reactivity of Fe0 towards 2,4‐DNT. The positive effect of K2SO4 is stronger than that of Na2SO4 at the same level (1 mmol L−1). Varying (NH4)2SO4 from 0.1 to 1.0 mmol L−1 improved the efficiency of 2,4‐DNT degradation by Fe0. The effects of varying NaNO3 and NaNO2 from 0 mmol L−1 to 4.7 mmol L−1 and 0 mmol L−1 to 5.8 mmol L−1, respectively, were also investigated. Both NaNO3 and NaNO2 at low concentration improved the efficiency of 2,4‐DNT degradation by Fe0, however, at high concentration, inhibiting effects appeared.

CONCLUSION: SO42−, Cl−, Na+, K+ and NH4+ notably enhanced 2,4‐DNT reduction by Fe0 at the tested concentrations. The positive effect of K+, Cl− was relatively stronger than that of Na+ and sulfate (SO42−). However, the effect of NH4+ was relatively weaker at concentrations greater than 1.0 mmol L−1. The presence of low concentrations of NO3− and NO2− promoted 2,4‐DNT reduction by Fe0 and inhibited the reaction. The results suggest that 2,4‐DNT reduction by Fe0 can be controlled by the ions composition of the waste‐water. Copyright © 2010 Society of Chemical Industry
Quantum‐dots‐based detection of hepatitis C virus (HCV) NS3 using RNA aptamer on chip
Authors: Roh Changhyun , Lee Ho‐Young , Kim Sang‐Eun , Jo Sung‐Kee
Published: April 2010

BACKGROUND: Over 170 million people, more than 3% of the world's population, suffer from the hepatitis C virus (HCV) infection and the rate of death from liver‐related mortality to HCV has increased. In respect of this, the development of assays for biological imaging should be urgently considered as an essential factor in diagnosis.

RESULTS: A novel HCV‐detecting technique using a nanoparticle‐supported aptamer probe was demonstrated. With the aid of nanoparticle quantum dots (QDs) with carboxyl group as an imaging probe, and 5′‐end‐amine‐modified RNA oligonucleotide as a capturing probe, target HCV NS3 was visually detected on chip. The QDs‐based RNA aptamer for HCV NS3 showed high selectivity and specificity against other protein such as BSA. The detection limit of HCV NS3 protein was 5 ng mL−1 level.

CONCLUSION: With a novel strategy for protein–aptamer interaction, the feasibility of applying QDs‐based fluorescent detection technique to HCV viral protein assay for the development of a protein biochip was demonstrated. This scheme of QDs‐mediated imaging with a target‐oriented specific RNA aptamer for the detection of infectious HCV diseases provides an efficient strategy and a promising new platform for monitoring applications. Copyright © 2010 Society of Chemical Industry
MRT Letter: Optimal composite depth function for 3D shape recovery of microscopic objects
Authors: Majid Abdul , Mahmood Muhammad Tariq , Choi Tae‐Sun
Published: April 2010

Generally, in shape from focus techniques, a single focus measure is used in estimating the three‐dimensional structure of microscopic objects. However, the performance of a single focus measure is limited to estimate accurately the depth map of diverse type of objects. To cope with this problem, we propose genetic programming based novel approach by developing an optimal composite depth (OCD) function for accurate depth estimation. This OCD function optimally combines the initial depth and focus information extracted from individual focus measures. An improved performance of this function is reported for synthetic and real world microscopic objects. Microsc. Res. Tech., 2010. © 2010 Wiley‐Liss, Inc.
Nanohybrid versus nanofill composite in class I cavities: Margin analysis after 12 months
Authors: de Andrade Ana Karina Maciel , Duarte Rosângela Marques , Guedes Lima Severino Jackson , Passos Tibério Andrade , Lima Kenio Costa , Montes Marcos Antônio Japiassú Resende
Published: April 2010

This study evaluates the margin of a nanofill, a nanohybrid, and a conventional microhybrid composite in restorations in occlusal cavities of posterior teeth after 12 months. Forty‐one patients, each with three molars affected by primary caries or the need to replace restorations, participated in this research. The teeth were restored with a nanofill (Filtek Z350), a nanohybrid (Esthet‐X), and a microhybrid as a control (Filtek Z250). Ten patients were selected randomly, and the three restorations were molded with a low‐viscosity polyvinyl siloxane material. The molds were poured with epoxy resin, gold‐sputter coated, observed by scanning electron microscopy, and classified as: “perfect margin,” “marginal irregularity,” “marginal gap,” “marginal fracture,” or “artifact.” For statistical analysis, the Wilcoxon and Friedman nonparametric tests and paired‐samples t‐test were used (significance level of 5%). The performance of the three materials was compared after 1 week and 12 months. No statistically significant differences were detected for all criteria (P > 0.05). When each composite was compared over time, statistically significant differences were found for the criterion, perfect margins (Esthet‐X and Filtek Z350, P < 0.05). The materials performed satisfactorily over the 12‐month‐observation period, but all composites under investigation showed a certain amount of deterioration relating to marginal quality over time. Microsc. Res. Tech. 74:23‐27, 2011. © 2010 Wiley‐Liss, Inc.
The development of PET radioligands for imaging the translocator protein (18 kDa): What have we learned?
Authors: Luus Christopher , Hanani Raphy , Reynolds Aaron , Kassiou Michael
Published: April 2010

The translocator protein (TSPO; 18 kDa), formerly known as the peripheral benzodiazepine receptor (PBR), is minimally expressed in the healthy brain. On the other hand, increased levels of TSPO have been noted in brain disorders for which an immune response is elicited. This increase in TSPO expression has been reported to coincide with the process of microglial activation making the measurement of TSPO density a useful indicator of active brain disease. To this end several new classes of TSPO positron emission tomography radioligands have been developed and evaluated. However, the incomplete pharmacological characterization of the TSPO and its ligands as well as differences in pathophysiology, pharmacology and molecular nature across species and tissue types means that caution must be exercised when comparing data obtained with various TSPO radioligands. A re‐evaluation of our interpretation of imaging data, which better correlates with our current understanding of TSPO pharmacology in disease, requires consideration. Copyright © 2010 John Wiley & Sons, Ltd.
Analysis of quadruple corner‐cut ridged square waveguide by hybrid mode‐matching boundary‐element method
Authors: Tao Yun , Shen Zhongxiang , Zheng Boyu
Published: April 2010

In this paper, the square waveguide with quadruple corner‐cut ridges is analyzed using the hybrid mode‐matching boundary‐element method. Because of its symmetry, only a quarter of its cross‐section needs to be considered and it is then divided into three regions. The electromagnetic field components in two regular regions can be obtained using the mode‐matching method and the third irregular region is discretized using the boundary‐element method. The combination of two methods produces one matrix equation, from whose determinant the cutoff wavenumbers of waveguide modes can then be computed. This hybrid technique takes advantage of the mode‐matching method's high efficiency and the boundary‐element method's versatility. The convergence of this hybrid method is studied, and numerical results are compared with the conventional boundary‐element method and commercial finite‐element software package, which shows that our hybrid method can achieve the same accuracy with much less time. The influence of the cut‐corners on the cutoff wavenumbers of the dominant and higher‐order modes is then examined. A simple approximate equation is found to accurately predict the cutoff wavenumber of TE20 mode. The single‐mode bandwidth of a quadruple ridged square waveguide is calculated thereafter, which shows that this corner‐cut structure can provide a broader bandwidth compared to the one without cut‐corners. Copyright © 2010 John Wiley & Sons, Ltd.
Using WCS‐FDTD method to simulate various cylindrical metallic enclosures
Authors: Chen Juan , Tian Chunming
Published: April 2010

The weakly conditionally stable (WCS) finite‐difference time‐domain (WCS‐FDTD) method in the cylindrical coordinate system is employed to compute the electromagnetic coupling and shielding of various cylindrical enclosures. In the WCS‐FDTD method, a larger time‐step size than that allowed by the Courant–Friedrich–Levy stability condition limitation can be set because the algorithm of this method is WCS. Consequently, an increase in computational efforts caused by fine cells due to thin sots can be prevented. The results from the WCS‐FDTD method agree well with the results from the conventional FDTD method, and the required CPU time for the WCS‐FDTD method is much shorter than that for the FDTD method. Careful investigation of different aspects of the shielding properties of the cylindrical enclosures is performed, and the shielding performance of the cylindrical enclosure and rectangular enclosure is compared. The result obtained in this paper can be used to design a practical cylindrical shielding enclosure. Copyright © 2010 John Wiley & Sons, Ltd.
A modified MPPT control loop for PV/battery‐charging system using PI controller optimally tuned with GA
Authors: Nafeh Abd El‐Shafy A.
Published: April 2010

In this study, a stand‐alone photovoltaic (PV)/battery‐charging system is proposed to efficiently charge a lead–acid battery with the available maximum power from the PV array. The relative sizing of the battery characteristics with respect to the PV array characteristics is indicated. The maximum‐power‐point (MPP)‐tracking operation is achieved through developing a new control loop, which is based on using the incremental conductance algorithm and the PI controller. The parameters of the PI controller are optimally tuned using the genetic algorithm (GA) by minimizing the integral of squared error and settling time. The proposed system was simulated twice by using MATLAB‐SIMULINK and by writing the appropriate MATLAB code in an M‐file. The SIMULINK model was designed to investigate the performance of the proposed system, whereas the M‐file model was designed to be used with the GA tool under MATLAB software, to optimally tune the PI controller. The simulation results indicated a rapid tracking capability for the PV array MPPs and a good matching between the PV array and the battery under various charging conditions. Copyright © 2010 John Wiley & Sons, Ltd.
A Raman spectroscopic study of the antimony mineral klebelsbergite Sb4O4(OH)2(SO4)
Authors: Frost Ray L. , Bahfenne Silmarilly
Published: April 2010

Many minerals based upon antimonite and antimonate anions remain to be studied. Most of the bands occur in the low wavenumber region, making the use of infrared spectroscopy difficult. This problem can be overcome by using Raman spectroscopy. The Raman spectra of the mineral klebelsbergite Sb4O4(OH)2(SO4) were studied and related to the structure of the mineral. The Raman band observed at 971 cm−1 and a series of overlapping bands are observed at 1029, 1074, 1089, 1139 and 1142 cm−1 are assigned to the SO42−ν1 symmetric and ν3 antisymmetric stretching modes, respectively. Two Raman bands are observed at 662 and 723 cm−1, which are assigned to the SbO ν3 antisymmetric and ν1 symmetric stretching modes, respectively. The intense Raman bands at 581, 604 and 611 cm−1 are assigned to the ν4 SO42− bending modes. Two overlapping bands at 481 and 489 cm−1 are assigned to the ν2 SO42− bending mode. Low‐intensity bands at 410, 435 and 446 cm−1 may be attributed to OSbO bending modes. The Raman band at 3435 cm−1 is attributed to the OH stretching vibration of the OH units. Multiple Raman bands for both SO42− and SbO stretching vibrations support the concept of the non‐equivalence of these units in the klebelsbergite structure. It is proposed that the two sulfate anions are distorted to different extents in the klebelsbergite structure. Copyright © 2010 John Wiley & Sons, Ltd.
Capacity of selected ionic liquids as alternative EP/AW additive
Authors: Schneider Ameneh , Brenner Josef , Tomastik Christian , Franek Friedrich
Published: April 2010

In this paper, it is shown that specific ionic liquids have great potential to be used as additives for tribological applications. The results promise a high load carrying capacity; especially for the cation 3‐Octhylthiazolium and long term stability up to temperatures of 120°C is given. However, only extreme pressures/anti‐wear properties are examined in detail with the selected test method. Friction modifier (FM) effectiveness cannot easily be demonstrated, because of the good performance of the selected base stock. Nevertheless, ionic liquids in general did not change the FM characteristic of the base oil in a negative way. A promising potential for ionic liquids to replace a majority of additives in tribological systems is given. Methods used are Schwing‐Reib‐Verschleiß test according to DIN ASTM D 5706, and Four Ball Tests according to DIN 51360. Mechanisms related to additives in lubricants are investigated by X‐ray photoelectron spectroscopy. Copyright © 2010 John Wiley & Sons, Ltd.
Effect of soil compositions on the electrochemical corrosion behavior of carbon steel in simulated soil solution
Authors: Liu T. M. , Wu Y. H. , Luo S. X. , Sun C.
Published: April 2010

In this study, effect of cations, Ca2+, Mg2+, K+, and anions, SO42–, HCO3–, NO3– on electrochemical corrosion behavior of carbon steel in simulated soil solution was investigated through potentiodynamic polarization curves and electrochemical impedance spectroscopy. The results indicate that the Ca2+and Mg2+ can decrease the corrosion current density of carbon steel in simulated soil solution, and K+, SO42–, HCO3–, and NO3– can increase the corrosion density. All the above ions in the simulated soil solution can decrease its resistivity, but they have different effect on the charge transfer resistivity. This finding can be useful in evaluating the corrosivity of certain soil through chemical analysis, and provide data for construction engineers.
Developing a hardening process for steel micro components in a drop‐tube furnace
Authors: von Bargen R. , von Hehl A. , Zoch H.‐W.
Published: April 2010

Due to the rising demand for small high‐performance products needed in wide sections of applications (for example automotive, micro electronics) the requirements for micro components concerning size scale (miniaturizing), quantity, costs and quality require new micro production processes to be developed. Dealing with the challenges of micro production the Collaborative Research Center 747 (CRC) “Micro Cold Forming” funded by the German Research Foundation was established at the University of Bremen in 2007. One of the elementary process steps during production is the heat treatment. The heat treatment process is responsible for the adjustment of the material properties in order to ensure the ability to form and furthermore to obtain the required mechanical properties. Given the challenges of handling the small and extremely sensitive components with an approximate volume of a cubic millimeter a new heat treatment process has been developed. An integrated 5.5 m high vertical drop‐tube furnace enables a short‐term austenitisation of steel components during falling. At the bottom of the furnace the quenching takes place by using water or ambient air as quenching medium. By this procedure the hardness of soft‐annealed components made of steel quality C100 could be increased from 2196 ± 241 HM 0.05/5.0 (revalued 254 ± 45 HV 0.005) up to nearly 6700 HM 0.05/5.0 (revalued 1050 HV 0.005).

In der Produktion von Mikrobauteilen nehmen die Anforderungen in Bezug auf Baugröße (Miniaturisierung), Stückzahl, Stückpreis und Qualität immer mehr zu. Die dabei auftretenden Herausforderungen werden seit 2007, im von der Deutschen Forschungsgemeinschaft geförderten Sonderforschungsbereich 747 “Mikrokaltumfomen”, an der Universität Bremen interdisziplinär angegangen. Einer der elementaren Fertigungsschritte in einer Prozesskette ist die Wärmebehandlung. Zum einen dient sie der Einstellung von Gefügeeigenschaften, die eine Kaltumformung, mit möglichst geringem Energie‐ und Krafteinsatz ermöglichen. Zum anderen muss nach der Umformung in vielen Fällen das Werkstück noch einmal wärmebehandelt werden, um die Gebrauchseigenschaften, zum Beispiel in Bezug auf die Festigkeit, einzustellen. Unter Berücksichtigung der Schwierigkeiten, welche beim konventionellen Chargieren von kleinen und empfindlichen Mikrobauteilen, mit einem Raumvolumen kleiner einem Kubikzentimeter, auftreten würden, wurde ein neuer Wärmebehandlungsprozess inklusiv Anlagentechnik entwickelt. Das Härten von Mikrobauteilen aus Stahl, in diesem Fall C100, wird in einem 5,5 m hohen vertikalen Fallrohrofen bei Temperaturen oberhalb von 1100°C, durch ein Kurzzeitaustenitisieren mit anschließender Abschreckung an ruhender Luft oder in Wasser durchgeführt. Mittels dieser Wärmebehandlung konnte die Härte des weichgeglühten Materials von 2196 ± 241 HM 0.05/5.0 (umgewertet 254 ± 45 HV 0.005) auf bis zu 6700 HM 0.05/5.0 (umgewertet 1050 HV 0.005) gesteigert werden.
Use of Ti in hard metal alloys – Part I: structural and microstructural analysis
Authors: Lamim J. D. , de Oliveira H. C. P , Batista A. C. , Guimarães R. S. , Filgueira M.
Published: April 2010

Nanosized WC, and binders Co, Ti and Ti‐Co, are used to process hardmetals. Titanium (Ti) was proposed to reduce and even replace the Co in these composites, verifying the effectiveness of the new binders. Samples of nanosized WC with 10 wt% Co, 9 wt% WC 1 wt% Ti – Co, WC‐10 wt% Ti were cold compacted at 200 MPa and sintered at 1500°C during 1 hour under vacuum of 10–2 mbar for the processing of hardmetal were performed. The structural characterization by X‐ray diffraction and microstructure by scanning electron microscopy (SEM) and EDS microanalysis of the sintered material. We observed the presence of the W2C phase in the sintered samples, and Co3W phases in the samples with Co content and a good distribution of binder phase, leading to formation of small “pool” of Co and Ti and small porosity and well distributed. It was proved that using Ti as binder phase, the neta phase formation was avoided.
Surface modification of fabrics for improved flash‐fire resistance using atmospheric pressure plasma in the presence of a functionalized clay and polysiloxane
Authors: Horrocks A. R. , Nazaré S , Masood R. , Kandola B. , Price D.
Published: April 2010

Improving flash‐fire resistance of otherwise flame resistant fabrics is a recognized challenge within the civil emergency and defence communities. Simulation of the flash‐fire condition using cone calorimetry has demonstrated the effectiveness of atmospheric plasma treatments in which either a functionalized clay, a polysiloxane (poly(hexamethyldisiloxane)) or both are deposited on to plasma‐activated fiber surfaces. Textile substrates comprised flame retardant (Proban®) cotton and a poly (meta‐aramid) (Nomex®). Results show that the generated surface layer has a measurable effect on fabric ignition and burning characteristics when exposed in a cone calorimeter at heat flux levels up to 70 kW/m2. Reductions in peak heat release rates (PHRR) are observed for all substrates especially for argon/clay and argon/clay/polysiloxane, plasma‐treated samples, with reductions of over 50% being observed for Proban® cotton and smaller reductions (≤20%) for Nomex® fabrics. Gravimetric, scanning electron microscopic, and cone calorimetric studies show that both original surface deposits and subsequent properties are retained after a simulated washing process including the argon/clay plasma‐treated Proban® and Nomex® fabrics in which no potentially binding polysiloxane was present. This suggests that plasma‐activated fiber surfaces in the presence of a functionalized clay enable relatively strong binding forces to be generated.

The results provide further evidence in addition to our earlier reported studies that atmospheric plasma treatment of fabric surfaces in the presence of a functionalized clay produces an inorganic coating that confers reduced flammability at the high heat fluxes used suggesting increased resistance to flash‐fire ignition. Copyright © 2010 John Wiley & Sons, Ltd.
Lesezeichen im Buch des Lebens. Epigenetik
Authors: Wagner Julia M. , Jung Manfred
Published: April 2010

In den 40er Jahren des vergangenen Jahrhunderts führte der englische Entwicklungsbiologe Conrad H. Waddington den Begriff Epigenetik ein. Hierunter versteht man heute vererbbare Änderungen, die nicht auf einer Änderung der Erbsubstanz beruhen.

Die Epigenetik ist ein hochaktuelles und stark beforschtes Gebiet in den Naturwissenschaften. Für den Pharmazeuten ist sie speziell deshalb von Interesse, da sie neue Ansätze zur Behandlung von Krankheiten wie Krebs liefert. Erste Arzneistoffe, die über epigenetische Mechanismen wirken, kamen in den letzten Jahren neu auf den Markt. Was genau sich hinter dem Begriff Epigenetik verbirgt, soll im folgenden Artikel dargestellt werden.
HDAC‐Inhibitoren als Therapie für neuronale Erkrankungen. Entdeckung neuer Anwendungsgebiete
Authors: Fischer Andre
Published: April 2010

Jüngste Daten weisen darauf hin, dass eine deregulierte Histon‐Acetylierung in eine Reihe von neurodegenerativen und kognitiven Erkrankungen involviert ist. Histondesacetylase‐Inhibitoren gelten daher als aussichtsreiche therapeutische Strategie für so unterschiedliche neuronale Erkrankungen wie Chorea Huntington, Morbus Alzheimer oder Schizophrenie. Dieser Artikel stellt die wichtigsten Ergebnisse dieses neuen Forschungsgebiets zusammen.
Epigenetische Therapie bei Myelodysplastischen Syndromen (MDS). Therapie mit DNA‐Methyltransferase‐Inhibitoren
Authors: Daskalakis Michael , Blagitko‐Dorfs Nadja , Hackanson Björn , Lübbert Michael
Published: April 2010

Derzeit können ältere Patienten mit einer symptomatischen MDS‐Erkrankung entweder supportiv, mit einem DNA‐Methyltransferase‐Inhibitor oder mit Lenalidomid (5q‐Syndrom) behandelt werden. Bei jüngeren Patienten im guten Allgemeinzustand steht als kurative Behandlungsoption die allogene Stammzelltransplantation zur Verfügung.

Mit dem Einsatz von 5‐Azacytidin und Decitabine als epigenetische Monotherapie kann älteren Patienten erstmals eine gut verträgliche Behandlung angeboten werden, welche zu einer Verzögerung der Krankheitsprogression, einer Verlängerung der Überlebenszeit und einer Verbesserung der Lebensqualität führt.

Derzeit ist es noch zu früh, um den möglichen Nutzen einer kombinierten Therapie aus DNA‐Methyltransferase‐ und Histondesacetylase‐Inhibitoren beurteilen zu können. Hier bleiben die Ergebnisse weiterer klinischer Phase‐II‐ und Phase‐III‐Studien abzuwarten.

Interessanterweise zeigen erste Studien einen positiven Effekt von 5‐Azacytidin und Decitabine als Immunmodulatoren im Rahmen der Konditionierungstherapie vor einer allogenen Stammzelltransplantation. Weitere klinische Studien müssen diesen Mechanismus eingehender evaluieren, um langfristig auch älteren Patienten durch nebenwirkungsärmere Konditionierungstherapien die kurative Option einer allogenen Transplantation zu ermöglichen.
Mechanical and thermal properties, morphology and relaxation characteristics of poly(lactic acid) and soy flour/wood flour blends
Authors: Li Yonghui , Venkateshan Karthik , Sun Xiuzhi Susan
Published: April 2010

Poly(lactic acid) (PLA) is a biodegradable polymer derived from sugar‐based materials, and its applications are varied. PLA blends are commonly employed to overcome certain disadvantages such as poor impact strength, low heat distortion temperature, poor processability and relatively high cost. In this study, blending PLA with soy flour (SF), wood flour (WF) and sodium bisulfite‐modified SF was used to improve the adhesion to PLA. In all cases, 0.5 wt% methylenediphenyl diisocyanate (MDI) was used as a coupling agent. Mechanical and thermal properties, morphology and relaxation characteristics of the blends were investigated. The results showed that MDI was an effective coupling agent for the WF/PLA system in improving tensile strength and elongation. Differential scanning calorimetry results indicated that SF and modified SF act as nucleation agents and facilitate the crystallization behavior of PLA by increasing the percentage crystallinity. From mechanical relaxation of the temperature‐variant system, we determined how the mechanical relaxation time evolves during the course of heating and obtained the Kohlrausch–Williams–Watts parameter and activation energy (ΔE). PLA and its blends exhibited highly homogeneous relaxational dynamics in their transition from glass to liquid, and ΔE of PLA and its blends is mainly affected by their densities and compositions. Copyright © 2010 Society of Chemical Industry