bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrasonics
Authors: Cantrell John H.
Published: March 2011

The fundamental physical and technical principles of ultrasound in solids and fluids are developed with an emphasis on the underlying relationship with thermodynamics. The development of concepts relevant for understanding the technical and analytical applications of ultrasound is stressed throughout the article. The notions of stress (pressure), strain, and elastic constants are introduced via the thermodynamic state functions. The basic wave equations are obtained and solved for various modes of wave propagation in unbounded propagation media. The introduction of bounded media with appropriate boundary conditions leads variously to the consideration of wave reflection and refraction, resonance phenomena, surface waves, and guided waves. Ultrasonic attenuation is introduced as a manifestation of wave scattering, diffraction, and energy absorption. The effects of relaxation processes in solids, liquids, and gases on the ultrasonic wave velocity and attenuation are considered from the perspective of irreversible thermodynamics. The origin of wave dispersion is addressed and discussed in the context of its influence on ultrasonic measurement parameters and techniques. Both contacting and noncontacting means of generating and detecting ultrasound are reviewed. Representative pulse, continuous wave, and optical techniques for measuring ultrasonic velocity and attenuation are summarized. Applications of ultrasound are emphasized and discussed at appropriate places throughout the article as the subject is developed. The article concludes with an extended review of industrial, medical, microscopical, and underwater applications.
Units
Authors: Siebert Bernd R. L. , Stenger Jörn
Published: March 2011

A generally accepted consistent system of dimensions and units is indispensable for trade, industrial production, communication in pure and applied science, and many other applications. Requirements on a system of units for expressing the values of quantities are presented and discussed.The International System of Units(SI), based on its recent eighth edition by the Bureau International des Poids et Measures (BIPM), is presented as such a consistent system of units. Guidance on its use is given and its future development is discussed. Support for converting non‐SI units to SI units is provided in an appendix.
Fundamentals of Materials Measurement and Testing
Authors: Czichos Horst
Published: March 2011

The article contains sections titled:

Introduction

Scope of Materials Measurement and Testing

Overview on Materials and Their Characteristics

Nature of Materials

Types of Materials

Processing of Materials

Scale of Materials

Properties of Materials

Application of Materials

Categories of Materials Characterization Methods

Characterization of Materials Composition

Elemental Chemical Analysis

Compound and Molecular Specific Analysis

Surface Chemical Analysis

Metrology in Elemental Analysis—An Example to Establish Traceability

Characterization of Materials Microstructure

Microstructural Analysis

Surface Topography Analysis

Characterization of Materials Properties

Mechanical Properties

Thermal Properties

Electrical Properties

Magnetic Properties

Optical Properties

Characterization of Materials Performance

Influences on Materials Integrity

Materials Deterioration Analysis

Aging

Biogenic Impact

Corrosion

Wear

Fracture

Nondestructive Evaluation

Ultrasonic Evaluation

Magnetic and Electrical Evaluation

Radiological Evaluation

Computerized Tomography

Reference Materials and Reference Procedures

Acknowledgments
Laser Spectroscopy
Authors: Inguscio Massimo , Rusciano Giulia , Sasso Antonio
Published: March 2011

Most of the actual knowledge of atomic and molecular structure derives from spectroscopic analysis of the radiation emitted when atoms or molecules are properly excited. The foundation of spectral analysis dates back to about 1860, with the work of Kirchhoff and Bunsen which argued that from the analysis of the emission by sample after a proper excitation it was possible to get information on the sample itself. Starting from this pioneering work, spectroscopic investigations have undergone an impressive evolution and applications have covered a wider a wider range. So far, besides fundamental physics, spectroscopic analysis are of direct importance in an increasing variety of applications in fields such asastrophysics, combusion, plasma physics, soft matter and, in recent years, bio‐medicine. In the following pages, the main techniques of laser spectroscopy are examined: starting from discovery of the hydrogen atom spectral series, the modern application of ultrasensitive spectroscopic techniques to sample constituted by only a few molecules (single molecule spectroscopy) are discussed. Of course, this contribution surely can not be exhaustive, and the reader is referred to more general treatments of the theory and practice of spectroscopy for a more detailed treatment.
Luteoviruses
Authors: Brault Véronique , Herrbach Etienne , Rodriguez‐Medina Caren
Published: March 2011

Luteoviruses, that is, members of the
Luteoviridae
family, are plant viruses that can infect a wide range of host plants, including many important crops such as cereals, cucurbits, legumes, potato, sugarbeet and sugar cane. Their icosahedral virions contain a single (+)
ribonucleic acid
genome in a capsid composed of two structural proteins. They are limited to phloem cells in host plants and are only transmitted by aphids in a circulative and nonpropagative mode with high specificity.

Growing data are accumulating on plant–luteovirus relationships and more particularly on the mechanism developed by the virus to overcome plant defence. The tight interaction between luteoviruses and their aphid vector has also been extensively studied. Information from these studies together with a better understanding of the epidemiology of luteoviruses will help to combat their detrimental effects on crops.

Key Concepts:

Luteoviruses have a highly compacted genome and use a diversity of translation mechanisms to express viral proteins.

Function of the viral gene products is known, but their plant and aphid partners have not been fully identified.

Luteoviruses are confined to phloem tissue, but the causes of their phloem restriction are not completely deciphered.

Luteoviruses circulate in the vector aphid's body, without any replication, by crossing the gut and the accessory salivary gland epithelia.

Epidemiology of luteoviruses reveals a high complexity of mutual ecological interactions between virus, plant and vector, influenced by multiple biotic and abiotic factors.

Control of luteoviral diseases includes cultural practices, insecticidal measures, natural and biotechnological plant resistance and epidemiology‐based forecasting systems.
Parainfluenza Viruses
Authors: Chambers Raychel , Takimoto Toru
Published: March 2011

Parainfluenza viruses are enveloped viruses that contain nonsegmented negative‐strand genomic
ribonucleic acid
(RNA). Replication of these viruses begins with entry by attachment and fusion, followed by genomic transcription and replication. Next, the

de novo

synthesised viral components are trafficked to assembly sites at the plasma membrane where newly formed virions bud out from the cell. These viruses are respiratory pathogens which act as the causative agents for croup, bronchiolitis and pneumonia. As a group, the parainfluenza viruses are second only to human respiratory syncytial virus as the cause of acute paediatric respiratory tract disease and are responsible for hundreds of thousands of additional U.S. hospitalisations per year. Despite their clinical importance, licensed vaccines or antiviral compounds for prevention or treatment of parainfluenza viruses are not currently available, making understanding the pathogenesis of these viruses critical for antiviral drug and vaccine development.

Key Concepts:

Parainfluenza viruses are enveloped, nonsegmented negative‐strand RNA viruses, which cause respiratory infections.

The structure of the virion consists of glycoprotein spikes protruding from a lipid envelope under which lies the matrix protein surrounding the viral nucleocapsid, consisting of viral RNA encapsidated by nucleoprotein and associated with the polymerase complex.

Specific interactions between the two envelope glycoproteins HN and F are necessary for efficient virus infection.

Because the viral genome is negative‐stranded RNA, an intermediate step is required for production of progeny viral genomes.

Newly synthesised viral nucleocapsids are transported to the assembly site at the plasma membrane utilising the microtubule network.

Pathogenicity of parainfluenza viruses is highly dependent on the anti‐interferon activity of the viral accessory proteins.

Infectious virus can be created from a complementary deoxyribonucleic acid (cDNA) clone of the viral RNA genome, which is termed reverse genetics.

The development of vaccines against parainfluenza viruses currently include intranasally administered vaccines attenuated by cold‐passage, host range attenuation, chimeric vaccine constructs, or the introduction of attenuating mutations through the use of reverse genetics.
Cutin and Suberin
Authors: Li‐Beisson Yonghua
Published: March 2011

Cutin and suberin are cell‐wall associated glycerolipid polymers specific to plants. Cutin forms the framework of the cuticle sealing the aerial epidermis, whereas suberin is present in the periderm of barks and underground organs. Suberised walls are also found in root internal tissues. Barriers based on cutin and suberin restrict transport of water across cell walls and limit pathogen invasions. Chemical analysis shows that both polymers are polyesters composed mostly of C16‐C18 hydroxyacids, diacids and epoxyacids esterified to each other and to glycerol. Suberin, whose best known form is cork, usually differs from cutin by a higher content in C20‐C24 aliphatics and aromatics. In the last decade, the identification of

Arabidopsis

mutants affected in cutin or suberin content has allowed the identification of several proteins involved in polyester biosynthesis, including
acyltransferases
with unique specificities,
fatty acid hydroxylases
,
acyl‐CoA synthetases
,
fatty acid elongases
and an ABC transporter.

Key Concepts:

The epidermal cells and suberising cells have specialised enzymes that convert the common cellular fatty acids into the unique components of cutin and suberin, respectively.

Oxygenated fatty acid monomers are produced by fatty acid oxidases of the cytochrome P450 superfamily.

Acylglycerol dimers can be synthesised by special glycerol‐3‐phosphate acyltransferases.

Whether polymerisation of dimers and monomers occurs in intracellular compartments or in the cell walls is still unknown.

How cutin and suberin polymers are linked to the cell walls remains to be determined.

Cutin contributes to the formation of surface nanostructures in epidermis.
Bayes' Factors
Authors: Johnson Valen E
Published: March 2011

Bayes' factors play a pivotal role in Bayesian hypothesis testing, representing the factor through which the prior odds between competing hypotheses are transformed to the posterior odds between the hypotheses. Mathematically, Bayes' factors are defined as the ratio of the marginal probability assigned to the data by one hypothesis to the marginal probability assigned to data by the other hypothesis. In many parametric statistical tests, hypotheses are defined by the specification of prior densities on unknown parameters. In such cases, Bayes' factors represent the ratio of an averaged likelihood function, averaged with respect to the different prior densities assigned to the unknown parameter under each hypothesis. Inconsistencies in the limiting behaviour of Bayes' factors may arise when hypotheses are defined with respect to prior densities that have overlapping support.

Key Concepts:

Bayes' factors are used in Bayesian hypothesis tests and are the key factors through which experimental data determine the posterior probability assigned to scientific hypotheses.

Bayes' factors represent the ratio of the probability assigned by competing hypotheses to a common set of data.

Bayes' factors equal the posterior odds divided by the prior odds between hypotheses.

The natural logarithm of a Bayes' factor is called the weight of evidence.
Brain Tumours
Authors: López Giselle Y , Cummings Thomas J , Bigner Darell D , McLendon Roger E
Published: March 2011

Brain tumour genetics allow for improved classification and development of therapeutic options for certain primary brain tumours. Tumours with specific genetic alterations and molecular profiles are also associated with certain inherited familial cancer syndromes, including Li–Fraumeni syndrome, neurofibromatosis and tuberous sclerosis. Recent advances in genetic profiling, from karyotype analyses to fluorescencein situhybridisation (FISH) to genome‐wide sequencing have greatly improved the understanding of the genetic basis for these tumours. Karyotype analyses rapidly identified loss of chromosome arms 1p and 19q as the most common genetic abnormality in oligodendrogliomas. Digital karyotyping identifiedOTX2in medulloblastomas, and further studies revealed its frequent overexpression in anaplastic medulloblastomas. Recently, genome‐wide sequencing identified three key pathways as mutated in the majority of glioblastomas, namely, thep53, retinoblastoma and receptortyrosine kinasepathways. Further analysis may prove key to identifying likely therapeutic targets.

Key Concepts:

The most common primary malignant brain tumour of adults is glioblastoma, a grade IV astrocytoma with an average survival of approximately 1 year following diagnosis.

Recent genome‐wide expression analyses have identified distinct expression patterns in glioblastoma patients which predict survival and may eventually be used to target therapies.

Three key pathways altered in the majority of astrocytomas include the receptor tyrosine kinase, p53 and retinoblastoma signalling pathways.

Epidermal growth factor receptor (EGFR) is overexpressed in the majority of glioblastomas and is frequently mutated to a constitutively active variant, EGFRvIII.

Mutations in IDH1 or IDH2 are the most common abnormality in both oligodendrogliomas and progressive astrocytomas, occurring in 60–90% of tumours.

The most characteristic chromosomal abnormality in oligodendrogliomas is complete allelic losses of chromosome 1p and 19q.

Gene expression microarray data has made possible the classification of medulloblastomas into subgroups based on expression of Sonic hedgehog pathway, Wnt pathway, neuronal differentiation or photoreceptor gene expression patterns.

The most common specific chromosomal abnormality in medulloblastomas is loss of 17p, which is often associated with gain of 17q.
Origin and Evolution of Insect Metamorphosis
Authors: Belles Xavier
Published: March 2011

Insect metamorphosis can be classified into three modalities: ametabolan (no changes), hemimetabolan (progressive changes) and holometabolan (dramatical changes at the end of the cycle). The metamorphic changes are mainly regulated by two hormones: the moulting hormone, which promotes the moults, and the juvenile hormone (JH), which represses the transformation into the adult. The action of these two hormones is mediated by a number of transcription factors, and the molecular mechanisms regulating the expression of these and of the corresponding target genes are finally refined by the action of microribonucleic acids. Among the different transcription factors involved, those of the Broad‐Complex group are especially interesting because they have a differential expression and JH dependency in holometabolans and hemimetabolans. Holometabolan metamorphosis probably evolved from hemimetabolan ancestors, although the mechanisms underlying such a transition are still obscure.

Key Concepts:

Insect metamorphosis can be classified into three modalities: ametabolan, hemimetabolan and holometabolan.

The main hormones involved in the regulation of insect metamorphosis are the moulting hormone and the juvenile hormone.

The molecular mechanisms underlying the action of the moulting hormone are reasonably well known, but those related to juvenile hormone are much less understood.

Broad‐Complex transcription factors are involved in the transduction of both, the moulting hormone and the juvenile hormone, but have a differential expression and juvenile hormone dependency in holometabolans and hemimetabolans.

Fossil record and phylogenetic reconstructions suggest that hemimetaboly evolved from ametabolan ancestors, whereas holometaboly derived from hemimetaboly.

Mechanisms underlying the evolutionary transitions from ametaboly to hemimetaboly and to holometaboly are still obscure and under debate.
Hogben, Lancelot
Authors: Tabery James
Published: March 2011

Lancelot Hogben, although less famous than contemporaries such as RA Fisher, Julian Huxley and JBS Haldane, left a lasting impression on twentieth‐ and twenty‐first‐century biology. Hogben's extensive background in experimental biology led him to introduce theinterdependence of nature and nurtureas a concept and tool for critiquing eugenic attempts to partition nature and nurture. This attention to the interdependence of nature and nurture can be traced into modern scientific practice (in research on gene–environment interaction, phenotypic plasticity and developmental systems theory) as well as modern scientific debate (in disputes over the limits of the human genome project, the heritability wars and the geneticisation of complex human traits).
Ultraviolet/Visible Light Detection and Ranging Applications in Air Monitoring
Authors: Wolf J.‐P.
Published: March 2011

Recent progress in light detection and ranging (LIDAR) and differential absorption light detection and ranging (DIAL) technology has allowed three‐dimensional (3‐D) mappings of concentrations of air pollutants to be obtained at the highest sensitivity (parts per billion) and over large distances (several kilometers). It is now possible to monitor on‐line spatial distributions of nitrogen oxides, sulfur dioxide, ozone, benzene, toluene, and aerosols. With the advent of tunable solid‐state laser systems, such as vibronic lasers and optical parametric oscillators (OPOs), LIDAR systems have furthermore reached industrial standards in terms of reliability and ease of operation. An overview of results and capabilities of “all‐solid‐state” LIDAR/DIAL systems is presented. The examples of application include detailed urban studies performed in large cities (e.g. Berlin, Leipzig, Lyon, Paris, Stuttgart, Geneva, Athens, and Seville), with special attention to smog formation processes and tropospheric ozone generation. Industrial applications are also numerous, such as site monitoring, identification of diffuse emissions, and evaluation of the impact of new emitters through plume dispersion studies. The use of LIDAR systems for validating numerical models is also discussed, along with intercomparison with standard analyzers and related certification issues. The last section is dedicated to a new class of LIDAR systems, based on femtosecond lasers, which not only allow multicomponent analysis but also possible weather modulation.
Electron Paramagnetic Resonance Imaging
Authors: Eaton Gareth R. , Eaton Sandra S.
Published: March 2011

Unpaired electrons can be measured by their absorption of electromagnetic radiation when the energy level separations established by a magnetic field match the energy of the incident electromagnetic radiation (usually microwave or radio frequency). The measurement method is called electron paramagnetic resonance (EPR). The EPR methodology can be continuous‐wave (CW), pulsed, or rapid‐scan EPR. Since the paramagnetic species are commonly not uniformly distributed in the material studied, the spatial distribution can be discerned by performing the EPR measurement in a magnetic‐field gradient, such that different parts of the sample resonate at different strengths of the applied magnetic field. Performing EPR in a gradient field and then constructing a spatial image from the acquired EPR spectra is called EPR imaging, sometimes abbreviated to EPRI. The method is analogous to MRI, but with several differences in implementation due to differences in spectral line widths, relaxation times, and unpaired spin concentrations. The goal of EPRI is to determine why the spins are where they are. Applications are as diverse as understanding physiology, measuring O2concentration in tumors, and determining the distribution of radiation‐induced defect centers in solid materials.
Matrix‐assisted Laser Desorption/Ionization Mass Spectrometry of Polymers
Authors: Pasch Harald , Alpheus Mautjana Nare
Published: March 2011

Matrix‐assisted laser desorption/ionization mass spectrometry (MALDI MS) has proved to be one of the best methods for identification and determination of the number of monomer units of simple polymers, including their end‐groups. However, most man‐made polymers are complex materials with numerous macromolecules (oligomers) of different chain lengths and different chemical compositions in one sample. Since MALDI MS primarily produces singly charged ions of each molecule in the sample, its mass spectra are easy to interpret and therefore useful for polymer characterization. Different oligomers of interesting polymers can be isolated in tandem mass spectrometry (MS/MS) for analysis of their monomer sequence to relate properties of the polymer to its molecular structure. Furthermore, the polymerization mechanism responsible for a given polymer can often be deduced from the oligomer structure. MALDI MS‐based methods have been used for the determination of molar mass distributions of complex polymers. However, to obtain meaningful data, proper understanding of polymer complexity as well as good insight of MALDI MS instrumentation and sample preparation protocol is necessary. Since the introduction of MALDI, different types of mass analyzers have been used. Each type has its advantages while other mass analyzers are simply not suitable for MALDI or for the targeted mass range.
Generation of Spatio‐Temporally Controlled Targeted Somatic Mutations in the Mouse
Authors: Metzger Daniel , Chambon Pierre
Published: March 2011

The generation of ligand‐activated site‐specific Cre recombinases has led to the development of cell type–specific temporally controlled targeted somatic mutagenesis in the mouse. We illustrate this technique using K14‐Cre‐ERT2 transgenic mice that express the tamoxifen (tam)‐activatable Cre‐ERT2 recombinase in epidermal basal keratinocytes to induce mutations in epidermal keratinocytes of adult mice. Our highly reproducible technique, based on induction of Cre‐ERT2 recombinase activity by tamoxifen administration at low doses (once daily 100‐µg intraperitoneal injection for 5 days), has allowed the generation of site‐directed somatic mutations of numerous genes in mouse epidermal keratinocytes, and several mouse models of human diseases. The present step‐by‐step protocol describes how to introduce temporally controlled targeted mutations in epidermal keratinocytes of adult mice. Curr. Protoc. Mouse Biol. 1:55‐70. © 2011 by John Wiley & Sons, Inc.
Imaging Cancer in Mice by PET, CT, and Combined PET‐CT
Authors: Mulero Francisca , Donate Luis E. , Serrano Manuel
Published: March 2011

The possibility of imaging tumors in live mice has opened new opportunities for cancer research, particularly regarding the ability to perform longitudinal studies in combination with a therapeutic intervention. Here, we detail methods to optimize visualization of murine tumors by positron emission tomography (PET), computed tomography (CT), and combined PET‐CT. Curr. Protoc. Mouse Biol. 1:85‐103. © 2011 by John Wiley & Sons, Inc.
Ethical Considerations in Mouse Experiments
Authors: Baertschi Bernard , Gyger Marcel
Published: March 2011

Mice count morally because they can be harmed. This raises a moral issue in animal experimentation. Three main ethical attitudes towards animals are reviewed here. The Kantian view denies moral value to animals because they lack reason. The second view, by Singer, considers animals as sentient creatures (i.e., able to suffer). Finally, Regan considers that animals are subjects of their own life; they are autonomous and therefore have moral rights. Singer is a reformist and allows animal experimentation under certain conditions. Regan is abolitionist, saying that animals have moral rights that cannot be negotiated. Current animal protection legislation strives to put in balance the human and animal interests to decide whether an animal experiment is morally justified or not. An ethical evaluation process is conducted based on the harm‐benefit assessment of the experiment. The researcher has to implement the 3Rs (Replacement, Reduction, Refinement) to minimize the harms to the animals and make sure that the outcomes are scientifically significant and that the quality of the science is high, in order to maximize benefits to humans and animals. Curr. Protoc. Mouse Biol. 1:155‐167. © 2011 by John Wiley & Sons, Inc.
High‐Resolution Patterning of Various Large‐Area, Highly Ordered Structural Motifs by Directional Photofluidization Lithography: Sub‐30‐nm Line, Ellipsoid, Rectangle, and Circle Arrays
Authors: Lee Seungwoo , Kang Hong Suk , Park Jung‐Ki
Published: March 2011

A major challenge in nanolithography is to overcome the resolution limit of conventional patterning methods. Herein, we demonstrate a simple and convenient approach to generate sub‐30‐nm various structural motifs with precisely controlled sizes, shapes, and orientations. The proposed method, the “directional photofluidization” of an azopolymer, follows the same philosophy as a path‐changing approach, for example, thermal‐reflow of polymer arrays, in that post‐treatment simultaneously leads to a reduction of the feature sizes and line‐edge roughness (LER) of nanostructures. However, in contrast to thermal‐induced isotropic reflow, directional photofluidization provides unprecedented flexibility to control the structural features, because the direction of photofluidization can be arbitrary controlled according to the light polarization. Furthermore, this approach offers good control of the final features due to a gradual reduction in the rate of photofluidization during light irradiation. More importantly, the photofluidic behavior of the azopolymer significantly reduces the LER, and thus it can improve the quality of nanostructures. Finally, the far‐field process of directional photofluidization enables hierarchical nanofabrication, in contrast to mechanical contact fabrication, because the patterned light can reconfigure the polymer arrays selectively. Our approach is potentially advantageous for the fabrication of various structural motifs with well‐controlled dimensions on the nanoscale and with minimized LER.
Ultrathin Transparent Au Electrodes for Organic Photovoltaics Fabricated Using a Mixed Mono‐Molecular Nucleation Layer
Authors: Stec Helena M. , Williams Rebecca J. , Jones Tim S. , Hatton Ross A.
Published: March 2011

A rapid, solvent free method for the fabrication of highly transparent ultrathin (∼8 nm) Au films on glass has been developed. This is achieved by derivatizing the glass surface with a mixed monolayer of 3‐mercaptopropyl(trim­ethoxysilane) and 3‐aminopropyl(trimethoxysilane) via co‐deposition from the vapor phase, prior to Au deposition by thermal evaporation. The mixed mono­layer modifies the growth kinetics, producing highly conductive films (∼11 Ω per square) with a remarkably low root‐mean‐square roughness (∼0.4 nm) that are exceptionally robust towards UV/O3 treatment and ultrasonic agitation in a range of common solvents. As such, they are potentially widely applicable for a variety of large area applications, particularly where stable, chemically well‐defined, ultrasmooth substrate electrodes are required, such as in organic optoelectronics and the emerging fields of nanoelectronics and nanophotonics. By integrating microsphere lithography into the fabrication process, we also demonstrate a means of tuning the transparency by incorporating a random array of circular apertures into the film. The application of these nanostructured Au electrodes is demonstrated in efficient organic photovoltaic devices where it offers a compelling alternative to indium tin oxide coated glass.
Influence of Phase Segregation on Recombination Dynamics in Organic Bulk‐Heterojunction Solar Cells
Authors: Baumann Andreas , Savenije Tom J. , Murthy Dharmapura Hanumantharaya K. , Heeney Martin , Dyakonov Vladimir , Deibel Carsten
Published: March 2011

The recombination dynamics of charge carriers in organic bulk‐heterojunction (BHJ) solar cells made of the blend system poly(2,5‐bis(3‐dodecylthiophen‐2‐yl)thieno[2,3‐b]thiophene) (pBTCT‐C12):[6,6]‐phenyl‐C61‐butyric acid methyl ester (PC61BM) with a donor–acceptor ratio of 1:1 and 1:4 are studied here. The techniques of charge‐carrier extraction by linearly increasing voltage (photo‐CELIV) and, as local probe, time‐resolved microwave conductivity are used. A difference of one order of magnitude is observed between the two blends in the initially extracted charge‐carrier concentration in the photo‐CELIV experiment, which can be assigned to an enhanced geminate recombination that arises through a fine interpenetrating network with isolated phase regions in the 1:1 pBTCT‐C12:PC61BM BHJ solar cells. In contrast, extensive phase segregation in 1:4 blend devices leads to an efficient polaron generation that results in an increased short‐circuit current density of the solar cells. For both studied ratios a bimolecular recombination of polarons is found using the complementary experiments. The charge‐carrier decay order of above two for temperatures below 300 K can be explained on the basis of a release of trapped charges. This mechanism leads to delayed bimolecular recombination processes. The experimental findings can be generalized to all polymer:fullerene blend systems allowing for phase segregation.
Synthesis of 3‐Arylindole‐2‐carboxylates via Copper‐Catalyzed Hydroarylation of o‐Nitrophenyl‐Substituted Alkynoates and Subsequent Cadogan Cyclization
Authors: Yamamoto Yoshihiko , Yamada Satoshi , Nishiyama Hisao
Published: March 2011

A two‐step route to biologically important 3‐arylindole‐2‐carboxylic esters has been successfully established: o‐nitrophenyl‐substituted alkynoates underwent copper‐catalyzed hydroarylation in the presence of commercially available arylboronic acids to afford 3,3‐diarylacrylates, which were then converted to indolecarboxylates via a modified Cadogan cyclization using a molybdenum catalyst and triphenylphosphine.
Catalytic De/Hydrogenation in Mg by Co‐Doped Ni and VOx on Active Carbon: Extremely Fast Kinetics at Low Temperatures and High Hydrogen Capacity
Authors: Jia Yi , Cheng Lina , Pan Nan , Zou Jin , (Max) Lu Gaoqing , Yao Xiangdong
Published: March 2011

A multi‐component catalyst Ni‐VOx/AC (VOx is comprised of V2O5 and VO2, x = 2.18) was synthesized by a wet impregnation method. The synthesized Ni‐VOx/AC shows a superior catalytic effect on de/hydrogenation of Mg. The MgH2+Ni‐VOx/AC composites can absorb 6.2 wt.‐% hydrogen within only 1 min at 150 °C under a hydrogen pressure of 2 MPa and desorb 6.5 wt.‐% hydrogen within 10 min at 300 °C under an initial hydrogen pressure of 1 KPa, which overcomes a critical barrier for practical use of Mg as a hydrogen storage material. A significant decrease of activation energy (Ea) indicates that Ni‐VOx/AC catalyst is highly efficient for Mg de/hydrogenation, which may be ascribed to the synergistic effect of bimetals (metal oxides) and nanocarbon.
Frugivory in four sympatric lemurs: implications for the future of Madagascar's forests
Authors: Wright Patricia C. , Tecot Stacey R. , Erhart Elizabeth M. , Baden Andrea L. , King Stephen J. , Grassi Christina
Published: March 2011

Although some conservationists accept that not all species can be saved, we illustrate the difficulty in deciding which species are dispensable. In this article, we examine the possibility that the integrity of a forest relies on its entire faunal assemblage. In Madagascar, one faunal group, the lemurs, accounts for the greatest biomass and species richness among frugivores. For example, 7 of the 13 sympatric lemur species in Madagascar's eastern rainforests consume primarily fruit. Because of this, we suggest that some tree species may rely heavily on particular lemur taxa for both seed dispersal and germination. In Ranomafana National Park, the diets for four of the day‐active lemur frugivores have been documented during annual cycles over a 5‐year period. We predicted that, although the fruit of some plant taxa would be exploited by multiple lemur species, the fruit of others would be eaten by one lemur species alone. Analyses reveal that while lemurs overlap in a number of fruit taxa exploited, 46% (16/35) of families and 56% (29/52) of genera are eaten exclusively by one lemur species. We, therefore, predict local changes in forest composition and structure if certain of these lemur species are eliminated from a forest owing to hunting, disease, or habitat disturbance. We also suggest that this result may be of global significance because carbon sequestration by the tropical forests in Madagascar may be reduced as a result of this predicted change in forest composition. Am. J. Primatol. 73:585–602, 2011. © 2011 Wiley‐Liss, Inc.
Surface‐engineered hydroxyapatite nanocrystal/ poly(ε‐caprolactone) hybrid scaffolds for bone tissue engineering
Authors: Kim So Yeon
Published: March 2011

To achieve novel polymer/bioceramic composite scaffolds for use in materials for bone tissue engineering, we prepared organic/inorganic hybrid scaffolds composed of biodegradable poly(ε‐caprolactone) (PCL) and hydroxyapatite (HA), which has excellent biocompatibility with hard tissues and high osteoconductivity and bioactivity. To improve the interactions between the scaffolds and osteoblasts, we focused on surface‐engineered, porous HA/PCL scaffolds that had HA molecules on their surfaces and within them because of the biochemical affinity between the biotin and avidin molecules. The surface modification of HA nanocrystals was performed with two different methods. Using Fourier transform infrared, X‐ray diffraction, and thermogravimetric analysis measurements, we found that surface‐modified HA nanocrystals prepared with an ethylene glycol mediated coupling method showed a higher degree of coupling (%) than those prepared via a direct coupling method. HA/PCL hybrid scaffolds with a well‐controlled porous architecture were fabricated with a gas‐blowing/particle‐leaching process. All HA/PCL scaffold samples exhibited approximately 80–85% porosity. As the HA concentration within the HA/PCL scaffolds increased, the porosity of the HA/PCL scaffolds gradually decreased. The homogeneous immobilization of biotin‐conjugated HA nanocrystals on a three‐dimensional, porous scaffold was observed with confocal microscopy. According to an in vitro cytotoxicity study, all scaffold samples exhibited greater than 80% cell viability, regardless of the HA/PCL composition or preparation method. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Osteoarthritis susceptibility genes influence the association between hip morphology and osteoarthritis
Authors: Waarsing J. H. , Kloppenburg M. , Slagboom P. E. , Kroon H. M. , Houwing‐Duistermaat J. J. , Weinans H. , Meulenbelt I.
Published: March 2011

Objective

The identified osteoarthritis (OA) susceptibility genes are mainly active in skeletal development and could thus affect joint geometry. Because nonoptimal joint geometry is a risk factor for the development of OA, we investigated if and how the path that leads from nonoptimal joint geometry to OA of the hip is influenced by these genes.

Methods

The shape of the hips of subjects in the Genetics, Osteoarthritis and Progression Study, consisting of sibling pairs with symptomatic OA at multiple joint locations, was quantified by applying a statistical shape model to radiographs. Shape aspects (modes) were correlated to OA characteristics. We then tested for the association of shape modes with OA susceptibility single‐nucleotide polymorphisms (SNPs) of GDF5, FRZB, and DIO2.

Results

Four of 23 shape modes (mode 1, mode 17, mode 18, and mode 21) were strongly associated with OA characteristics. We observed a significant interaction between carrier status of DIO2 rs12885300 and hip OA characteristics for mode 1 (P = 0.005). This indicates that this specific aspect of hip shape correlates with OA characteristics only in carriers of the susceptibility allele.

Conclusion

Our results suggest that it is more likely that the rs12885300 SNP of DIO2 increases the vulnerability of cartilage to nonoptimal bone shapes rather than directly influencing the formation of these shapes.
Comparison of traditional methods with 3D computer models in the instruction of hepatobiliary anatomy
Authors: Keedy Alexander W. , Durack Jeremy C. , Sandhu Parmbir , Chen Eric M. , O'Sullivan Patricia S. , Breiman Richard S.
Published: March 2011

This study was designed to determine whether an interactive three‐dimensional presentation depicting liver and biliary anatomy is more effective for teaching medical students than a traditional textbook format presentation of the same material. Forty‐six medical students volunteered for participation in this study. Baseline demographic information, spatial ability, and knowledge of relevant anatomy were measured. Participants were randomized into two groups and presented with a computer‐based interactive learning module comprised of animations and still images to highlight various anatomical structures (3D group), or a computer‐based text document containing the same images and text without animation or interactive features (2D group). Following each teaching module, students completed a satisfaction survey and nine‐item anatomic knowledge post‐test. The 3D group scored higher on the post‐test than the 2D group, with a mean score of 74% and 64%, respectively; however, when baseline differences in pretest scores were accounted for, this difference was not statistically significant (P = 0.33). Spatial ability did not statistically significantly correlate with post‐test scores for the 3D group or the 2D group. In the post‐test satisfaction survey the 3D group expressed a statistically significantly higher overall satisfaction rating compared to students in the 2D control group (4.5 versus 3.7 out of 5, P = 0.02). While the interactive 3D multimedia module received higher satisfaction ratings from students, it neither enhanced nor inhibited learning of complex hepatobiliary anatomy compared to an informationally equivalent traditional textbook style approach. Anat Sci Educ 4: 84–91, 2011. © 2011 American Association of Anatomists.
Chondroprotective effects of pulsed electromagnetic fields on human cartilage explants
Authors: Ongaro Alessia , Pellati Agnese , Masieri Federica Francesca , Caruso Angelo , Setti Stefania , Cadossi Ruggero , Biscione Roberto , Massari Leo , Fini Milena , De Mattei Monica
Published: March 2011

This study investigated the effects of pulsed electromagnetic fields (PEMFs) on proteoglycan (PG) metabolism of human articular cartilage explants from patients with osteoarthritis (OA). Human cartilage explants, recovered from lateral and medial femoral condyles, were classified according to the International Cartilage Repair Society (ICRS) and graded based on Outerbridge scores. Explants cultured in the absence and presence of IL‐1β were treated with PEMF (1.5 mT, 75 Hz) or IGF‐I alone or in combination for 1 and 7 days. PG synthesis and release were determined. Results showed that explants derived from lateral and medial condyles scored OA grades I and III, respectively. In OA grade I explants, after 7 days exposure, PEMF and IGF‐I significantly increased35S‐sulfate incorporation 49% and 53%, respectively, compared to control, and counteracted the inhibitory effect of IL‐1β (0.01 ng/ml). The combined exposure to PEMF and IGF‐I was additive in all conditions. Similar results were obtained in OA grade III cartilage explants. In conclusion, PEMF and IGF‐I augment cartilage explant anabolic activities, increase PG synthesis, and counteract the catabolic activity of IL‐1β in OA grades I and III. We hypothesize that both IGF‐I and PEMF have chondroprotective effects on human articular cartilage, particularly in early stages of OA. Bioelectromagnetics 32:543–551, 2011. © 2011 Wiley‐Liss, Inc.
Genotoxic effects of 3 T magnetic resonance imaging in cultured human lymphocytes
Authors: Lee Joong Won , Kim Myeong Seong , Kim Yang Jee , Choi Young Joo , Lee Younghyun , Chung Hai Won
Published: March 2011

The clinical and preclinical use of high‐field intensity (HF, 3 T and above) magnetic resonance imaging (MRI) scanners have significantly increased in the past few years. However, potential health risks are implied in the MRI and especially HF MRI environment due to high‐static magnetic fields, fast gradient magnetic fields, and strong radiofrequency electromagnetic fields. In this study, the genotoxic potential of 3 T clinical MRI scans in cultured human lymphocytes in vitro was investigated by analyzing chromosome aberrations (CA), micronuclei (MN), and single‐cell gel electrophoresis. Human lymphocytes were exposed to electromagnetic fields generated during MRI scanning (clinical routine brain examination protocols: three‐channel head coil) for 22, 45, 67, and 89 min. We observed a significant increase in the frequency of single‐strand DNA breaks following exposure to a 3 T MRI. In addition, the frequency of both CAs and MN in exposed cells increased in a time‐dependent manner. The frequencies of MN in lymphocytes exposed to complex electromagnetic fields for 0, 22, 45, 67, and 89 min were 9.67, 11.67, 14.67, 18.00, and 20.33 per 1000 cells, respectively. Similarly, the frequencies of CAs in lymphocytes exposed for 0, 45, 67, and 89 min were 1.33, 2.33, 3.67, and 4.67 per 200 cells, respectively. These results suggest that exposure to 3 T MRI induces genotoxic effects in human lymphocytes. Bioelectromagnetics 32:535–542, 2011. © 2011 Wiley‐Liss, Inc.
Fetal head anomaly restricted to the eye, the mandible, and the pterygoid process of the sphenoid: A histological study
Authors: Jin Zhe Wu , Li Chun Ai , Kim Ji Hyun , Shibata Shunichi , Murakami Gen , Cho Baik Hwan
Published: March 2011

A report on an unusual combination of anomalies in the head of a female fetus. The authors examined whole body semiserial paraffin sections of a female fetus (155 mm CRL; ∼18 weeks of gestation), with a particular focus on the head region. Cranial autonomic ganglia, nasal olfactory cells, and the orbital muscle were investigated using immunohistochemistry for tyrosine hydroxylase, vasoactive intestinal peptide, calretinin, and smooth muscle actin expression. The surface gross anatomy of the fetus appeared normal. The left eyeball lacked a lens (the eyeballs were otherwise normal). The orbital muscle was very thick and located in the anterolateral side of the extraocular muscles. Conversely, the extraocular muscles made a cluster in the superoposterior side of the orbit. The infratemporal fossa was small due to the bulky, transversely extended lateral pterygoid process in contrast to the small coronoid process of the mandible. The bilateral mandibular bases overlapped at the midline symphysis. The thin orbitosphenoid and thick alisphenoid provided an almost flat, anterior cranial base. Nasal olfactory cells and cranial autonomic ganglia appeared to be normal. No major anomaly was observed in the brain. Because of the changes in topographical anatomy, the orbital muscle probably lost its normal bony attachment and appeared to push the extraocular muscles superoposteriorly. A gene function redundancy rather than mutation may explain the present restricted anomalies in the mandible and pterygoid process. Clin. Anat. 24:599–606, 2011. © 2011 Wiley‐Liss, Inc.
Henry Jacob Bigelow (1818–1890): His contributions to anatomy and surgery
Authors: Malenfant Jason , Robitaille Martin , Schaefer Jamie , Tubbs R. Shane , Loukas Marios
Published: March 2011

There have been many advances in the medical world over time that have greatly contributed to ameliorating and prolonging human life. The employment of surgical anesthesia is arguably one of the greatest medical discoveries of all time, and has immensely broadened our ability to treat the ill. While Dr. Henry Jacob Bigelow (1818–1890) was not the inventor of anesthesia, he was the first to publish and advocate its use in the 19th century (Bigelow and Bigelow [1894] A Memoir of Henry Jacob Bigelow, Boston: Little, Brown, and Company; Harrington and Mumford [1905] The Harvard Medical School: A History, Narrative and Documentary, Vol 2, New York: Lewis Publishing Company). Bigelow also contributed to revolutionizing the fields of orthopedic and urologic surgery, publishing extensive research on subjects where there was previously very little knowledge, and even developing new techniques. He also impacted the field of neuropsychiatry in his publication regarding Phineas Gage. His contributions to the medical field have set him apart as one of the most influential and famous surgeons of America in the 19th century. Anatomically, he will be remembered eponymously for his iliofemoral ligament and septum in the femur. Clin. Anat. 24:539–543, 2011. © 2011 Wiley‐Liss, Inc.
Structure and Function of Intrinsically Disordered Proteins. By Peter Tompa.
Authors: Lemke Edward A.
Published: March 2011

CRC Press, Boca Raton 2010, XXVII+331 pp., hardcover $ 99.95.—ISBN 978‐1‐4200‐7892‐3
Development of Lipid Targeting Raman Probes for In Vivo Imaging of Caenorhabditis elegans
Authors: Charan Shobhit , Chien Fan‐Ching , Singh Narendra , Kuo Chiung‐Wen , Chen Peilin
Published: March 2011

A simple, sensitive, and highly specific lipid targeting Raman probe (Nile red coated silver nanoparticles) has been developed to image living nematode Caenorhabditis elegans (C. elegans). Our idea of imaging lipids in C. elegans is to combine the specificity of the fluorescent dye, Nile red, and the highly enhanced Raman scattering on the silver nanoparticles. Our strategy involves the fabrication of a lipid targeting probe, which is incorporated into the intracellular intestinal granules of C. elegans by incubating these worms in the solution containing Raman probes, resulting in an uptake and subsequent incorporation of these Raman probes into the intestinal granule, thus allowing fast visualization of lipid droplets through a conventional confocal imaging technique.
Total Synthesis of Chloptosin: A Dimeric Cyclohexapeptide
Authors: Oelke Alexander J. , Antonietti Francesca , Bertone Leonardo , Cranwell Philippa B. , France David J. , Goss Rebecca J. M. , Hofmann Tatjana , Knauer Stephan , Moss Steven J. , Skelton Paul C. , Turner Richard M. , Wuitschik Georg , Ley Steven V.
Published: March 2011

Here we describe in full our investigations into the synthesis of the dimeric cyclohexapeptide chloptosin in 17 linear steps. Particularly, this work features an organocatalytic tandem process for the synthesis of the embedded piperazic acids, in which a differentially protected azodicarboxylate is used together with pyrrolidinyl tetrazole as the catalyst. The central biaryl bond is being formed by Stille coupling of two sterically demanding ortho‐chloropyrroloindole fragments. The inherent flexibility of the synthetic strategy proved beneficial as the route could be adjusted smoothly during the progression of the synthesis programme.