bluuebunny/crossref_metadata_2025 huggingface dataset:
Astroviruses
Authors: Schultz‐Cherry Stacey
Published: April 2015

Astroviruses are positive‐sense, single‐stranded RNA viruses encoding three open reading frames. However, the exact number of processed proteins remains unknown. Originally identified as a common cause of childhood diarrhoea, especially in children under 2 years of age, astroviruses are now recognised as an infection of diverse mammals and birds. Disease can range from asymptomatic to mild, self‐limiting gastroenteritis, as well as nephritis, hepatitis and encephalitis in certain host species. Astrovirus pathogenicity and immune response is only poorly characterised and may differ between mammalian and avian species. Given the wide host range and extensive genetic diversity among species, it is not surprising that classifying astrovirus family members remains a challenge. In this article, the current knowledge of astroviruses is reviewed, including their replication, viral evolution, pathogenesis and immune response.

Key Concepts

The
Astroviridae
are a complex family of emerging viruses.

Astrovirus pathogenesis and host immune responses remain an underexplored area of investigation.

Astroviruses may be more prevalent in humans than previously recognised.

Astroviridae
classification and nomenclature for newly identified genotypes are needed.

Astroviruses are associated with more than gastroenteritis.
Zebrafish as an Experimental Organism
Authors: Bielen Holger
Published: April 2015

Over the last 20 years, the popularity of the zebrafish model has grown more rapidly than any other vertebrate model, and by now the zebrafish is used for virtually all disciplines of biological and medical research. New sophisticated advances in gene editing, transgenesis, 3D‐imaging and behavioural assay design have been established successfully and complemented the ‘tool box’ to make the zebrafish one of the most powerful vertebrate model organisms. There is now information available on expression of over 12 000 genes and about 1000 mutant phenotypes. The latest high‐quality sequence assembly of the zebrafish genome allows in‐depth comparative genomic analysis which will further enhance the use of zebrafish as a model for human diseases. Together with the previously established techniques such as forward genetics, cell‐transplantation, ‐ablation and ‐extraction, which can now be used for new generation sequencing analysis with temporal‐spatial precision, the zebrafish provides an outstanding
in vivo
vertebrate model to study development and human disease.

Key Concepts

The advantages of the zebrafish model include rapid development, short generation time, large number of offspring and transparency of the embryos

The zebrafish has become an excellent genetic model organism, amenable to forward genetic screens, targeted mutagenesis and efficient transgenesis

Using the zebrafish as a research model for developmental biology, regeneration, chemical screens and disease will expand our knowledge in basic and clinical research
D
e
G
raaf,
R
egnier
Authors: van Ruler Han
Published: April 2015

Regnier de Graaf (1641–1673) was a Dutch anatomist, experimental physiologist and innovative theorist, who received his medical training at Leiden University during a particularly creative period of methodological improvements in the field. Continuing his physiological studies even as a practitioner in Delft, de Graaf personally cultivated a scientific attitude to medical and biological questions that would bring him lasting fame, especially for his description of the female reproductive organs and his interpretation of the nature of mammalian ovaries. The term ‘Graafian follicle’, which stands for a mature ovarian follicle containing a ripened ovum, is derived from his name.
Hemichordates: Development
Authors: Miyamoto Norio , Wada Hiroshi
Published: April 2015

Hemichordates are marine invertebrates consisting of two distinct groups: the solitary enteropneusts, or acorn worms (comprising a few hundred species), and the colonial and tube‐dwelling pterobranchs (comprising 20 or so species). Phylogenetically, hemichordates are the sister group to echinoderms, together composing the Ambulacraria, and share some features with chordates. Hemichordates are thus considered key organisms for addressing the origins of deuterostome and chordate body plans. Unlike the other deuterostome models including echinoderms and chordates, however, information about the developmental biology of this group is limited. Recent improvements in the accessibility of embryos, functional tool development and genomic resources from several model organisms have yielded important information on the cellular and genetic mechanisms of embryogenesis and organogenesis in hemichordates. Comparisons of hemichordates and other deuterostomes permit identification of the common ancestor of deuterostomes and help elucidate the origin of the chordate body plan.

Key Concepts

Hemichordate developmental biology is key to elucidating the origin of chordates and the early evolution of deuterostomes.

Descriptive and comparative studies using novel model species provide new insights into hemichordate evolution and diversity.

Establishment of genetic resources and experimental methods drive the molecular developmental biology of hemichordates.

Hemichordates and chordates show a conserved anteroposterior patterning mechanism.

Hemichordate research indicates that inversion of the dorsoventral axis occurred in the chordate lineage.

Gill slits of hemichordates and chordates are almost certainly homologous.

The stomochord of hemichordates and the notochord of chordates share some genetic features, but are unlikely to be homologous.

The origin of the tubular nervous system predates the diversification of hemichordates and chordates, but the homology of the collar nerve cord and neural tube still requires resolution.
Obesity: Genetics
Authors: Grant Struan FA , McCormack Shana E
Published: April 2015

Obesity is a disorder of energy balance. In obese individuals, there is excess body fat accumulation, which can lead to myriad health problems. The dysregulation of energy intake (appetite) and energy expenditure (activity) in obesity remains incompletely understood, but studies in humans and in model systems clearly demonstrate a strong genetic component to this condition. Within the past decade, major progress has been made in characterising the genetic component of obesity, with genome‐wide association studies revealing the most loci, including identifying the strongest association signal harboured within the
FTO
gene. Such studies have thus provided greater insight into the aetiology of this complex trait and are aiding in making diagnostic and therapeutic inroads into this common health concern.

Key Concepts

Obesity is characterised by an accumulation of excess adipose tissue that has myriad adverse health effects in virtually every organ system.

The rising global prevalence of obesity, particularly in developing nations and in children, is worrisome and incompletely understood.

Despite clear environmental contributions to disease risk, obesity is highly heritable.

In so‐called ‘syndromic’ genetic forms of obesity, genetic changes lead to obesity along with involvement of other organ systems. In ‘non‐syndromic’ obesity, genetic changes lead to an obesity‐predominant phenotype. Animal models of these conditions have led to important insights on the hypothalamic control of appetite.

Technological advances have led to the ability to perform genome‐wide association studies and identify novel genes and pathways related to obesity.

The complex interaction between genetics/epigenetics and myriad factors including the microbiome, diet/environment, physical activity and circadian rhythm may hold clues as to what individualised therapeutics may improve prevention and treatment of this highly morbid condition.
C
harles
B
.
D
avenport
Authors: Sohasky Kate E
Published: April 2015

Charles Benedict Davenport (1866–1944) was one of the most prominent public figures of the eugenics movement in the early decades of the twentieth century in the United States. Trained as a morphologist, biologist and geneticist, he is most remembered for his eugenic studies. Under his direction of Cold Spring Harbor Laboratory on Long Island, New York, the research conducted by the laboratory's Eugenics Record Office supported the early eugenics movement by serving as the leading repository of eugenic information and as a primary centre for the training of eugenic field workers.
DNA
Methylation: Enzymology
Authors: Jurkowska Renata Z , Jeltsch Albert
Published: April 2015

Methylated bases (C5‐methylcytosine, N4‐methylcytosine and N6‐methyladenine) are found in the DNA of most species, where they play important biological roles. There exist two families of DNA methyltransferases with specificity for methylation of the C5 position of cytosine or exocyclic amino groups of cytosine or adenine. They all use
S
‐adenosyl‐l‐methionine as the methyl group donor and contain a catalytic domain with a similar fold. In bacteria, methylation of DNA is used to distinguish self and foreign DNA, to direct post‐replicative mismatch repair, co‐ordinate DNA replication and cell cycle and for regulation of gene expression. In vertebrates, DNA methylation is established by three DNA methyltransferases (Dnmt1, Dnmt3a and Dnmt3b) in a cell‐type‐specific pattern, mainly at the CG sites. It functions as an epigenetic mark and is involved in the regulation of chromatin accessibility in many biological contexts. Bacterial DNA methyltransferases are mainly directed by the DNA sequence of their target site, whereas mammalian and plant Dnmts are recruited and regulated by several factors and other epigenetic signals, including modification of histone tails or RNA molecules.

Key Concepts

DNA methylation adds information to the DNA that is not encoded in the DNA sequence.

DNA methyltransferases use AdoMet as methyl group donor and flip their target base out of the DNA helix.

DNA methylation in bacteria reflects the sequence specificity of the bacterial methyltransferases, whereas eukaryotic enzymes are targeted and regulated by a network of different mechanisms.

Maintenance of mammalian DNA methylation patterns is mainly encoded in the palindromic nature of the CG site and is coupled to DNA replication.

Eukaryotic DNA methyltransferases are recruited by specific histone modifications generating a network of interconnected epigenetic signals.
Microtubule Plus‐End‐Tracking Proteins
Authors: Pereira Ana L , Maiato Helder
Published: April 2015

Microtubules are dynamic cytoskeletal components necessary for several intracellular processes, including cell division, differentiation, migration and intracellular transport. Microtubule plus‐end‐tracking proteins (+TIPs) consist of a highly diversified group of evolutionary conserved families of proteins that preferentially accumulate at the plus‐ends of microtubules. Importantly, +TIPs are capable of interacting with each other, which allows the establishment of complex protein networks greatly implicated in the regulation of microtubule behaviour. These networks play an important role mediating the interactions between microtubules and several cellular structures, such as membranes, kinetochores and the actin cytoskeleton, thereby influencing cellular architecture and coordinating diverse biological processes. For these reasons, +TIPs have been extensively studied, including the peculiar structural features allowing for the generation of networks, the mechanisms behind microtubule plus‐end‐tracking and their respective roles in the cell.

Key Concepts

+TIPs consist of an evolutionarily conserved, yet highly diversified group of proteins that preferentially accumulate at the plus‐end of microtubules regulating their dynamics.

In their structure +TIPs can comprise specialized domains fit to directly interact with tubulin, or able to bind proteins capable of autonomously associating with tubulin.

The establishment of +TIPs networks responsible for the regulation of microtubule dynamics is important for numerous biological processes in interphase and mitosis.
Spin Filtering through Single‐Wall Carbon Nanotubes Functionalized with Single‐Stranded DNA
Authors: Alam Kazi M. , Pramanik Sandipan
Published: April 2015

High spin polarization materials or spin filters are key components in spintronics, a niche subfield of electronics where carrier spins play a functional role. Carrier transmission through these materials is “spin selective,” that is, these materials are able to discriminate between “up” and “down” spins. Common spin filters include transition metal ferromagnets and their alloys, with typical spin selectivity (or, polarization) of ≈50% or less. Here carrier transport is considered in an archetypical one‐dimensional molecular hybrid in which a single wall carbon nanotube (SWCNT) is wrapped around by single stranded deoxyribonucleic acid (ssDNA). By magnetoresistance measurements it is shown that this system can act as a spin filter with maximum spin polarization approaching ≈74% at low temperatures, significantly larger than transition metals under comparable conditions. Inversion asymmetric helicoidal potential of the charged ssDNA backbone induces a Rashba spin‐orbit interaction in the SWCNT channel and polarizes carrier spins. The results are consistent with recent theoretical work that predicted spin dependent conductance in ssDNA‐SWCNT hybrid. Ability to generate highly spin polarized carriers using molecular functionalization can lead to magnet‐less and contact‐less spintronic devices in the future. This can eliminate the conductivity mismatch problem and open new directions for research in organic spintronics.
Light‐Emitting Paper
Authors: Asadpoordarvish Amir , Sandström Andreas , Larsen Christian , Bollström Roger , Toivakka Martti , Österbacka Ronald , Edman Ludvig
Published: April 2015

A solution‐based fabrication of flexible and light‐weight light‐emitting devices on paper substrates is reported. Two different types of paper substrates are coated with a surface‐emitting light‐emitting electrochemical cell (LEC) device: a multilayer‐coated specialty paper with an intermediate surface roughness of 0.4 μm and a low‐end and low‐cost copy paper with a large surface roughness of 5 μm. The entire device fabrication is executed using a handheld airbrush, and it is notable that all of the constituent layers are deposited from solution under ambient air. The top‐emitting paper‐LECs are highly flexible, and display a uniform light emission with a luminance of 200 cd m−2 at a current conversion efficacy of 1.4 cd A−1.
High‐Performance Organic Lithium Batteries with an Ether‐Based Electrolyte and 9,10‐Anthraquinone (AQ)/CMK‐3 Cathode
Authors: Zhang Kai , Guo Chunyang , Zhao Qing , Niu Zhiqiang , Chen Jun
Published: April 2015

Organic carbonyl electrode materials of lithium batteries have shown multifunctional molecule design and high capacity, but have the problems of poor cycling and low rate performance due to their high solubility in traditional carbonate‐based electrolytes and low conductivity. High‐performance organic lithium batteries with modified ether‐based electrolyte (2 m LiN(CF3SO2)2 in 1,3‐dioxolane/dimethoxyethane solvent with 1% LiNO3 additive (2m‐DD‐1%L)) and 9,10‐anthraquinone (AQ)/CMK‐3 (AQC) nanocomposite cathode are reported here. The electrochemical results manifest that 2m‐DD‐1%L electrolyte promotes the cycling performance due to the restraint of AQ dissolution in ether‐based electrolyte with high Li salt concentration and formation of a protection film on the surface of the anode. Additionally, the AQC nanocomposite improves the rate performance because of the nanoconfinement effect of CMK‐3 and the decrease of charge transfer impedance. In 2m‐DD‐1%L electrolyte, AQC nanocomposite delivers an initial discharge capacity of 205 mA h g−1 and a capacity of 174 mA h g−1 after 100 cycles at 0.2 C. Even at a high rate of 2 C, its capacity is 146 mA h g−1. This strategy is also used for other organic carbonyl compounds with quinone substructures and they maintain high stable capacities. This sheds light on the development of advanced organic lithium batteries with carbonyl electrode materials and ether‐based electrolytes.
Synthesis of (−)‐Deoxynupharidine by Allenic Hydroxylamine Cyclisation
Authors: Bates Roderick W. , Lim Chia Juan , Collier Steven J. , Sukumaran Joly
Published: April 2015

(−)‐Deoxynupharidine has been synthesised via an intermediate that can also be used for other Nuphar alkaloids. Significant steps include the optimised enzymatic resolution of an allenic alcohol, highly diastereoselective silver‐catalysed cyclisation of an allenic hydroxylamine, selective cross‐metathesis, diastereoselective intramolecular reductive amination, and stereoelectronically controlled enolate alkylation.
Strategy for Internal Labeling of Large RNAs with Minimal Perturbation by Using Fluorescent PNA
Authors: Schmitz Anita G. , Zelger‐Paulus Susann , Gasser Gilles , Sigel Roland K. O.
Published: April 2015

Fluorescence techniques for the investigation of biomolecules and their folding pathways require an efficient labeling strategy. A common method to internally label large RNAs involves the introduction of long loops for hybridization of fluorophore‐carrying DNA strands. Such loops often disturb the structure, and thus the functionality, of the RNA. Here we show, in a proof of concept study with a >600 nucleotide group II intron ribozyme, that the usage of the nucleic acid analogue peptide nucleic acid (PNA) is more efficient in several aspects, minimizing the required structural modifications of the RNA. We demonstrate by various methods, including smFRET, that much smaller concentrations and shorter PNAs can be applied, compared to DNA, for rapid and specific internal RNA labeling. The folding pathway and catalytic activity of this large ribozyme is only minimally affected by the PNA, but the background signal is significantly reduced.
Thermally Stabilized Cobalt‐Based Fischer–Tropsch Catalysts by Phosphorous Modification of Al2O3: Effect of Calcination Temperatures on Catalyst Stability
Authors: Woo Min Hee , Cho Jae Min , Jun Ki‐Won , Lee Yun Jo , Bae Jong Wook
Published: April 2015

A phosphorous‐modified Al2O3 support was prepared by the impregnation method and applied for the preparation of cobalt‐based Fischer–Tropsch synthesis (FTS) catalysts (Co/P–Al2O3), which were calcined at different temperatures. The Co/P–Al2O3 showed a significant increase of thermal stability with a higher catalytic performance without severe deactivation even above a calcination temperature of 600 °C compared with the unmodified Co/Al2O3. These findings are explained by the suppressed cobalt aluminate formation and less pronounced aggregation of cobalt particles. The suppressed aggregation of cobalt particles is attributed to the localized presence of aluminum phosphate by forming a thermally stable metal–phosphorous oxo‐species on Al2O3 surfaces thus suppressing the migration of cobalt particles to the outer pore mouths of the support. These effects significantly enhance the catalytic activity with a higher thermal stability of the catalysts.
Recent Progress in Non‐Platinum Counter Electrode Materials for Dye‐Sensitized Solar Cells
Authors: Theerthagiri Jayaraman , Senthil Arumugam Raja , Madhavan Jagannathan , Maiyalagan Thandavarayan
Published: April 2015

Dye‐sensitized solar cells (DSSCs) have gained increasing attention with regard to photovoltaic devices, because of their low cost and simple fabrication methods; they are mostly investigated in indoor light‐harvesting and portable applications. The focus has been on three main parameters of photovoltaic devices, that is, lifetime, and cost effectiveness. A DSSC consists of four prominent components including a photoanode, a photosensitizer, a redox electrolyte, and a counter electrode. The counter electrode is a crucial component, in which triiodide is reduced to iodide by electrons flowing through the external circuit. An effective approach to improve the performance of a counter electrode is to enhance the power conversion efficiency and to reduce the cost of the device. Platinum‐coated conducting glass electrodes give the best performance, but their high cost and the scarcity of platinum restricts large‐scale application in DSSCs. This has prompted researchers to develop low‐costing platinum‐free electrodes for DSSCs. In this review, we focus mainly on counter electrode materials for the electrocatalytic redox reaction for the I−/${{\rm{I}}_{\rm{3}}^ - }$ electrolyte, and apart from this, other counter electrode materials for iodine‐free redox electrolytes are discussed. Different counter electrode materials are highlighted in different categories such as carbon materials, conducting polymers, oxide and sulfide materials, transition‐metal nitrides and carbides, and composite materials. The stability of counter electrodes in DSSCs is also presented.
Establishing the Coordination Chemistry of Antimony(V) Cations: Systematic Assessment of Ph4Sb(OTf) and Ph3Sb(OTf)2 as Lewis Acceptors
Authors: Robertson Alasdair P. M. , Chitnis Saurabh S. , Jenkins Hilary A. , McDonald Robert , Ferguson Michael J. , Burford Neil
Published: April 2015

The coordination chemistry of the stiboranes Ph4Sb(OTf) (1 a, OTf = OSO2CF3) and Ph3Sb(OTf)2 (3) with Lewis bases has been investigated. The significant steric encumbrance of the Sb center in 1 a precludes interaction with most ligands, but the relatively low steric demands of 4‐methylpyridine‐N‐oxide (OPyrMe) and OPMe3 enabled the characterization of [Ph4Sb(OPyrMe)][OTf] (2 a) and [Ph4Sb(OPMe3)][OTf] (2 b), rare examples of structurally characterized complexes of stibonium acceptors. In contrast, 3 was found to engage a variety of Lewis bases, forming stable isolable complexes of the form [Ph3Sb(donor)2][OTf]2 [donor=OPMe3 (6 a), OPCy3 (6 b, Cy=cyclohexyl), OPPh3 (6 c), OPyrMe (6 d)], [Ph3Sb(dmap)2(OTf)][OTf] (6 e, dmap=4‐(dimethylamino)pyridine) and [Ph3Sb(donor)(OTf)][OTf] [donor=1,10‐phenanthroline (7 a) or 2,2′‐bipy (7 b, bipy=bipyridine)]. These compounds exhibit significant structural diversity in the solid‐state, and undergo ligand exchange reactions in line with their assignment as coordination complexes. Compound 3 did not form stable complexes with phosphine donors, with reactions instead leading to redox processes yielding SbPh3 and products of phosphine oxidation.
Trio Catalysis Merging Enamine, Brønsted Acid, and Metal Lewis Acid Catalysis: Asymmetric Three‐Component Aza‐Diels–Alder Reaction of Substituted Cinnamaldehydes, Cyclic Ketones, and Arylamines
Authors: Deng Yongming , Kumar Siddhartha , Wheeler Kraig , Wang Hong
Published: April 2015

A trio catalyst system, composed of arylamine, BINOL‐derived phosphoric acid, and Y(OTf)3, enables the combination of enamine catalysis with both hard metal Lewis acid catalysis and Brønsted acid catalysis for the first time. Using this catalyst system, a three‐component aza‐Diels–Alder reaction of substituted cinnamaldehyde, cyclic ketone, and arylamine is carried out with high chemo‐ and enantioselectivity, affording a series of optically active 1,4‐dihydropyridine (DHP) derivatives are obtained in 91–99 % ee and 59–84 % yield. DHPs bearing a chiral quaternary carbon center are also obtained with good enantioselectivity and moderate yield (three examples). Preliminary mechanistic investigations have also been conducted.
Development and psychometric evaluation of the Quality of Patient‐Centered Cancer Care measure with hematological cancer survivors
Authors: Tzelepis Flora , Sanson‐Fisher Robert W. , Hall Alix E. , Carey Mariko L. , Paul Christine L. , Clinton‐McHarg Tara
Published: April 2015

BACKGROUND

The Institute of Medicine (IOM) recommended 6 objectives for achieving patient‐centered care. However, most patient‐reported outcome measures developed with cancer populations fail to address all 6 patient‐centeredness dimensions. The Quality of Patient‐Centered Cancer Care (QPCCC) measure was developed on the basis of IOM recommendations, and the measure's validity, reliability, and floor and ceiling effects were examined.

METHODS

The development of the QPCCC measure included interviews with hematological cancer survivors and feedback from hematologists and cancer patients. To evaluate the measure's psychometric properties, hematological cancer survivors were identified via 2 cancer registries and were mailed the QPCCC measure. To examine test‐retest reliability, a second QPCCC measure was mailed to survivors 7 to 14 days after they had returned the first measure.

RESULTS

Overall, 545 hematological cancer survivors completed the 48‐item QPCCC measure. Exploratory factor analysis revealed a 10‐factor structure with factor loadings > 0.40. The subscales were labeled Treatment Delivery, Treatment Decision Making, Coordinated and Integrated Care, Emotional Support, Timely Care, Follow‐Up Care, Respectful Communication, Patient Preferences and Values, Cancer Information, and Equitable Care. The QPCCC measure demonstrated acceptable internal consistency for all subscales (Cronbach's α = .73‐.94). When test‐retest reliability was assessed, 4 items demonstrated substantial agreement (κ > 0.60), whereas 40 items showed moderate agreement (κ = 0.41‐0.60). Ceiling effects were present for 8 subscales.

CONCLUSIONS

The QPCCC measure has acceptable face and content validity, construct validity, and internal consistency. However, the measure's discriminant validity and test‐retest reliability could be improved. The QPCCC measure could be used to improve patient‐centered cancer care. Cancer 2015;121:2383–2392. © 2015 American Cancer Society.
Effect of Dimethyl Carbonate on the Dynamic Properties and Ionicities of Ionic Liquids with [MIII(hfip)4]− (M=B, Al) Anions
Authors: Rupp Alexander B. A. , Welle Sabrina , Klose Petra , Scherer Harald , Krossing Ingo
Published: April 2015

Several ionic liquids (ILs) comprising [B(hfip)4]− [hfip=OCH(CF3)2] or [Al(hfip)4]− anions and imidazolium or ammonium cations were prepared and mixed with up to 270 mol % of dimethyl carbonate (DMC). The viscosities, conductivities, and self‐diffusion constants of these mixtures and, where possible, of the neat ILs were measured and compared with common [NTf2]− based ILs and their mixtures with DMC. A tremendous decrease of the viscosities and a likewise increase of the conductivities and diffusion constants can be achieved for all classes of ILs. However, the order of the conductivities is partially reversed in the diffusion data. This is probably due to the low dielectric constant of DMC and the, thus, favored ion pairing, as evidenced, for example, by the calculated ionicities. Altogether, our data show that the chemically robust, but high‐melting and more viscous [B(hfip)4]− ILs might be candidates for electrolytes when mixed with suitable molecular solvents.
Output‐capacitorless segmented low‐dropout voltage regulator with controlled pass transistors
Authors: Saberkari Alireza , Qaraqanabadi Farima , Shirmohammadli Vahideh , Martínez Herminio , Alarcon Eduard
Published: April 2015

This article presents a low quiescent current output‐capacitorless quasi‐digital complementary metal‐oxide‐semiconductor (CMOS) low‐dropout (LDO) voltage regulator with controlled pass transistors according to load demands. The pass transistor of the LDO is segmented into two smaller sizes based on a proposed segmentation criterion, which considers the maximum output voltage transient variations due to the load transient to different load current steps to find the suitable current boundary for segmentation. This criterion shows that low load conditions will cause more output variations and settling time if the pass transistor is used in its maximum size. Furthermore, this situation is the worst case for stability requirements of the LDO. Therefore, using one smaller transistor for low load currents and another one larger for higher currents, a proper trade‐off between output variations, complexity, and power dissipation is achieved. The proposed LDO regulator has been designed and post‐simulated in HSPICE in a 0.18 µm CMOS process to supply a stable load current between 0 and 100 mA with a 40 pF on‐chip output capacitor, while consuming 4.8 μA quiescent current. The dropout voltage of the LDO is set to 200 mV for 1.8 V input voltage. The results reveal an improvement of approximately 53% and 25% on the output voltage variations and settling time, respectively. Copyright © 2015 John Wiley & Sons, Ltd.
Parallel domain decomposition method for finite element approximation of 3D steady state non‐Newtonian fluids
Authors: Shiu Wen‐Shin , Hwang Feng‐Nan , Cai Xiao‐Chuan
Published: April 2015

We introduce a stabilized finite element method for the 3D non‐Newtonian Navier–Stokes equations and a parallel domain decomposition method for solving the sparse system of nonlinear equations arising from the discretization. Non‐Newtonian flow problems are, generally speaking, more challenging than Newtonian flows because the nonlinearities are not only in the convection term but also in the viscosity term, which depends on the shear rate. Many good iterative methods and preconditioning techniques that work well for the Newtonian flows do not work well for the non‐Newtonian flows. We employ a Galerkin/least squares finite element method, with stabilization parameters adjusted to count the non‐Newtonian effect, to discretize the equations, and the resulting highly nonlinear system of equations is solved by a Newton–Krylov–Schwarz algorithm. In this study, we apply the proposed method to some inelastic power‐law fluid flows through the eccentric annuli with inner cylinder rotation and investigate the robustness of the method with respect to some physical parameters, including the power‐law index and the Reynolds number ratios. We then report the superlinear speedup achieved by the domain decomposition algorithm on a computer with up to 512 processors. Copyright © 2015 John Wiley & Sons, Ltd.
Learning Through Play
Authors: Honeyford Michelle A. , Boyd Karen
Published: April 2015

Play has a significant role in language and literacy learning. However, even when valued in schools, opportunities for play are limited beyond early childhood education. This study of an after‐school program for adolescents looks closely at several forms of play that students engaged in to produce self‐portraits. The study suggests that play and experimentation with visual texts, tools, spaces, peers, and materials contributed to students’ engagement with complex visual literacy practices. Two important implications are discussed: (1) that learning through play is a participatory, inclusive approach to literacy that invites adolescent students, even those often reticent to take risks, to cultivate literacy practices and identities; and (2) that visual modes of literacy play and production enable an experiential understanding of academic literacy concepts adaptable to other modalities and contexts.
Acrylamide induces locomotor defects and degeneration of dopamine neurons in Caenorhabditis elegans
Authors: Li Jia , Li Dan , Yang Yongsheng , Xu Tiantian , Li Ping , He Defu
Published: April 2015

Acrylamide can form in foods during the cooking process and cause multiple adverse effects. However, the neurotoxicity and mechanisms of acrylamide have not been fully elucidated. In Caenorhabditis elegans, we showed that 48 h exposure to 10–625 mg l−1 acrylamide resulted in a significant decline in locomotor frequency of body bending, head thrashing and pharynx pumping. In addition, acrylamide exposure reduced crawling speeds and changed angles of body bending. It indicates that acrylamide induces locomotor defects, along with parkinsonian‐like movement impairment, including bradykinesia and hypokinesia. Acrylamide also affected chemotaxis plasticity and reduced learning ability. Using transgenic nematodes, we found that acrylamide induced downexpression of Pdat‐1 and led to the degeneration of dopaminergic neurons. Moreover, the enhanced expression of unc‐54, encoding a subunit of α‐synuclein was found. It illustrates that acrylamide is efficient in inducing crucial parkinsonian pathology, including dopaminergic damage and α‐synuclein aggregation. These findings suggest the acrylamide‐induced locomotor defects and neurotoxicity are associated with Parkinson's disease. Copyright © 2015 John Wiley & Sons, Ltd.
The integumental appendages of the turtle shell: An evo‐devo perspective
Authors: Moustakas‐Verho Jacqueline E. , Cherepanov Gennadii O.
Published: April 2015

The turtle shell is composed of dorsal armor (carapace) and ventral armor (plastron) covered by a keratinized epithelium. There are two epithelial appendages of the turtle shell: scutes (large epidermal shields separated by furrows and forming a unique mosaic) and tubercles (numerous small epidermal bumps located on the carapaces of some species). In our perspective, we take a synthetic, comparative approach to consider the homology and evolution of these integumental appendages. Scutes have been more intensively studied, as they are autapomorphic for turtles and can be diagnostic taxonomically. Their pattern of tessellation is stable phylogenetically, but labile in the individual. We discuss the history of developmental investigations of these structures and hypotheses of evolutionary and anomalous variation. In our estimation, the scutes of the turtle shell are an evolutionary novelty, whereas the tubercles found on the shells of some turtles are homologous to reptilian scales. J. Exp. Zool. (Mol. Dev. Evol.) 324B: 221–229, 2015. © 2015 Wiley Periodicals, Inc.
Prevalence of impaired memory in hospitalized adults and associations with in‐hospital sleep loss
Authors: Calev Hila , Spampinato Lisa M. , Press Valerie G. , Meltzer David O. , Arora Vineet M.
Published: April 2015

BACKGROUND

Effective inpatient teaching requires intact patient memory, but studies suggest hospitalized adults may have memory deficits. Sleep loss among inpatients could contribute to memory impairment.

OBJECTIVE

To assess memory in older hospitalized adults, and to test the association between sleep quantity, sleep quality, and memory, in order to identify a possible contributor to memory deficits in these patients.

DESIGN

Prospective cohort study.

SETTING

General medicine and hematology/oncology inpatient wards.

PATIENTS

Fifty‐nine hospitalized adults at least 50 years of age with no diagnosed sleep disorder.

MEASUREMENTS

Immediate memory and memory after a 24‐hour delay were assessed using a word recall and word recognition task from the University of Southern California Repeatable Episodic Memory Test. A vignette‐based memory task was piloted as an alternative test more closely resembling discharge instructions. Sleep duration and efficiency overnight in the hospital were measured using actigraphy.

RESULTS

Mean immediate recall was 3.8 words out of 15 (standard deviation = 2.1). Forty‐nine percent of subjects had poor memory, defined as immediate recall score of 3 or lower. Median immediate recognition was 11 words out of 15 (interquartile range [IQR] = 9–13). Median delayed recall score was 1 word, and median delayed recognition was 10 words (IQR = 8–12). In‐hospital sleep duration and efficiency were not significantly associated with memory. The medical vignette score was correlated with immediate recall (r = 0.49, P < 0.01).

CONCLUSIONS

About half of the inpatients studied had poor memory while in the hospital, signaling that hospitalization might not be an ideal teachable moment. In‐hospital sleep was not associated with memory scores. Journal of Hospital Medicine 2015;10:439–445. © 2015 Society of Hospital Medicine.
The association of patient complexities with antibiotic ordering
Authors: Wooten Darcy , Kahn Katherine , Grein Jonathan D. , Eells Samantha J. , Miller Loren G.
Published: April 2015

BACKGROUND

Antibiotic treatment decisions for medically complex patients are complicated, as the risk of undertreatment may be severe, whereas overtreatment may be associated with adverse effects and the emergence of antibiotic resistant pathogens.

OBJECTIVE

To determine the influence of patient complexities on providers’ decisions to prescribe antibiotics in 3 common hospital‐based clinical vignettes.

DESIGN

A physician survey.

SETTING

Three urban medical centers in Los Angeles County, California.

PARTICIPANTS

Hospital‐based physicians.

MEASUREMENTS

Physicians were presented 3 clinical vignettes, with variations by patient age, comorbidity burden, functional status, and follow‐up, and asked to choose the best antibiotic regimen. We described the association of additional patient complexity on the proportion of guideline‐adherent antibiotic choices.

RESULTS

In the survey, 28% to 49% of physicians recommended antibiotics that were inconsistent with national guidelines. This percentage increased to 48% to 63% for medically complex patients, defined as those with either older age, high medical comorbidity burden, poor functional status, or limited follow‐up after hospital discharge (P < 0.01).

CONCLUSIONS

In 3 vignettes depicting common clinical scenarios among hospitalized adults, inappropriate antibiotic use was prevalent and occurred more often for patients with medical complexities. Treatment guidelines should consider addressing medically complex patients in the context of infection management. Journal of Hospital Medicine 2015;10:446–452. © 2015 Society of Hospital Medicine
Effect of fermented medicinal plants on growth performance, nutrient digestibility, fecal noxious gas emissions, and diarrhea score in weanling pigs
Authors: Zhao Pinyao , Li Hanlin , Lei Yan , Li Tianshui , Kim Sunki , Kim Inho
Published: April 2015

BACKGROUND

Antibiotics used as growth promoters in livestock have been banned in the European Union since 2006. Alternatives of antibiotics have focused on phytogenic plants, such as herbs and medicinal plants. No studies have evaluated the use of fermented medicinal plants (FMP) made up of Gynura procumbens, Rehmannia glutinosa and Scutellaria baicalensis in weanling pigs. Therefore, an experiment was conducted to determine the effects of FMP on growth performance, nutrient digestibility, fecal noxious gas emissions and diarrhea score in weanling pigs.

RESULTS

FMP supplementation increased (P < 0.05) average daily gain, average daily feed intake, gain:feed, apparent total tract digestibility of dry matter, nitrogen and gross energy compared with NC treatment, while a linear effect (P < 0.05) was observed on those criteria. Ammonia, total mercaptans and hydrogen sulfide concentrations were decreased (P < 0.05) by the supplementation of FMP compared with NC. Additionally, diarrhea score was lower (P < 0.05) by FMP addition compared with NC during days 0–7 and days 8–14.

CONCLUSION

These results suggested that FMP could be used as an alternative to antibiotics by enhancing growth performance and nutrient digestibility, and decreasing fecal noxious gas emission and early diarrhea score of weanling pigs. © 2015 Society of Chemical Industry
Free amino acids analysis by liquid chromatography with tandem mass spectrometry in several botanicals with antioxidant character
Authors: Moldoveanu Serban C. , Zhu Jeff , Qian Nancy
Published: April 2015

A novel method based on liquid chromatography with tandem mass spectrometry for the analysis of 19 amino acids in plant materials is described. For the analysis, the plant material is extracted with 0.1 N hydrochloric acid with internal standards present in the extraction solution. The filtered extracts are injected using no clean‐up into the liquid chromatographic system coupled with a triple‐quadrupole tandem mass spectrometer with an electrospray ionization source. The analytes are separated using ion pair chromatography on a reversed‐phase column. The detection is performed in multiple‐reaction monitoring positive‐ion mode. Quantitation is obtained using calibrations. The validated procedure has been applied for the analysis of amino acids in 18 samples of plant material including botanicals with antioxidant character. The analysis requires 16 min separation time, has excellent precision and accuracy allowing amino acid analysis in a wide range of concentrations.
The role of postoperative hematoma on free flap compromise
Authors: Ahmad Faisal I. , Gerecci Deniz , Gonzalez Javier D. , Peck Jessica J. , Wax Mark K.
Published: April 2015

Objectives/Hypothesis

Hematomas may develop in the postoperative setting after free tissue transfer. When hematomas occur, they can exert pressure on surrounding tissues. Their effect on the vascular pedicle of a free flap is unknown. We describe our incidence of hematoma in free flaps and outcomes when the flap is compromised.

Study Design

Retrospective chart review of 1,883 free flaps performed between July 1998 and June 2014 at a tertiary referral center.

Methods

Patients with free flap compromise due to hematoma were identified. Etiology, demographic data, and outcomes were evaluated.

Results

Eighty‐eight (4.7%) patients developed hematomas. Twenty (22.7%) of those had flap compromise. Twelve compromises (60%) showed evidence of pedicle thrombosis. The salvage rate was 75% versus 54% in 79 flaps with compromise from other causes (P = .12). Mean time to detection of the hematoma was 35.3 hours in salvaged flaps compared to 91.6 hours in unsalvageable flaps (P = .057). Time to operating room (OR) from detection was 2.8 hours in salvageable flaps compared to 12.4 hours in nonsalvageable flaps (P = .053). The salvage rate for flaps that returned to the OR in <5 hours was 93.3% compared to 20% (P = .0049) for those that did not. Vascular thrombosis reduced salvage rate to 58.3% from 100% (P = .002) when there was no thrombosis.

Conclusions

In our series hematomas developed rarely. When they did, 23% went on to develop flap compromise. Prompt recognition and re‐exploration allowed for a high salvage rate. Vessel thrombosis predicted inability to salvage the flap.

Level of Evidence

4 Laryngoscope, 125:1811–1815, 2015
Unusual airway complication after percutaneous tracheotomy: Case report and literature review
Authors: Roxbury Christopher , Qualliotine Jesse , Molena Daniela , Kim Young
Published: April 2015

We report a case of a 59‐year‐old male who experienced tracheoesophageal fistula and grade IV subglottic stenosis after percutaneous dilation tracheotomy. Although percutaneous tracheotomy is considered a safe procedure that is often performed in the intensive care unit setting, it is not without complications. While subglottic stenosis and tracheoesophageal fistula are known complications of percutaneous tracheotomy, this report discusses a patient who experienced both complications simultaneously. The purpose of this report is to discuss potential serious complications of percutaneous tracheotomy and their management, and to review the literature on percutaneous tracheotomy complications.

Level of Evidence

NA Laryngoscope, 125:1883–1885, 2015
Self‐reported Tobacco use does not correlate with carcinogen exposure in smokers with head and neck cancer
Authors: Khariwala Samir S. , Carmella Steven G. , Stepanov Irina , Bandyopadhyay Dipankar , Nelson Heather H. , Yueh Bevan , Hatsukami Dorothy K. , Hecht Stephen S.
Published: April 2015

Objectives/Hypothesis

Head and neck squamous cell carcinoma (HNSCC) is strongly associated with tobacco use. We sought to examine the relationship between self‐reported tobacco use and the level of urinary tobacco carcinogen metabolites in a cohort of patients with HNSCC.

Study Design

Cross‐sectional analysis.

Methods

Eighty‐four cigarette smokers with head and neck cancer completed tobacco and alcohol use questionnaires, and the following urinary tobacco metabolites were quantified: 1‐hydroxypyrene (1‐HOP), N'‐nitrosonornicotine and its glucuronides (total NNN), 4‐(methylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanol and its glucuronides (total NNAL), and cotinine. A cross‐sectional analysis was performed with assessment of correlation coefficients.

Results

When analyzed based on self‐reported cigarettes per day (CPD), no significant correlation with any of the studied tobacco carcinogen metabolites was found. However, urinary cotinine showed significant correlation with total NNN, total NNAL, and 1‐HOP. Total NNN, total NNAL, and 1‐HOP showed significant correlation with each other suggesting exposure occurs to each proportionally.

Conclusions

In smokers with HNSCC, self‐reported tobacco use does not predict actual carcinogen exposure. In contrast, urinary cotinine levels significantly correlate with carcinogen levels. Therefore, urinary cotinine is the preferred value for estimating carcinogen dose in these patients. 1‐HOP levels were significantly associated with total NNN and total NNAL suggesting that smokers are exposed to these carcinogens proportionally. These data indicate that utilizing conventional methods of estimating tobacco exposure (CPD) may not accurately approximate exposure to tobacco carcinogens in smokers with HNSCC. These data have implications for future studies focused on screening and epidemiology of smokers with HNSCC.

Level of Evidence

NA Laryngoscope, 125:1844–1848, 2015
Extensive evaporation in a modern temperate estuary: Stable isotopic and compositional evidence
Authors: Barrie Gemma M. , Worden Richard H. , Barrie Craig D. , Boyce Adrian J.
Published: April 2015

Estuaries have long been recognized as sites of major compositional fluctuations that can have a range of effects including mineral growth in the water column and in the underlying estuarine sediment. We have studied chloride and sodium concentrations and stable isotopes (H and O) from a suite of estuarine waters from the temperate Anllóns estuary in NW Spain to assess the complexity of estuarine mixing process. Water samples were collected hourly from in estuary sites over three consecutive days and end‐member samples were collected on each sampling day. Evaporative concentration of the estuarine waters is demonstrated by the maximum concentration of geochemically conservative chloride being as much as 17.5% greater in the estuary than in the local seawater. Relative to chloride concentration, both δ2H and δ18O values of estuary waters tend to be more enriched than would be expected for the simple physical mixing of river water and seawater. These patterns can only be plausibly accounted for through evaporation affecting the water, concentrating the chloride and causing isotope fractionation. We have modelled the effects of evaporation on chloride concentration and the stable isotopes in the estuary; the results closely match the distribution of analytical data suggesting that up to 40% evaporation has happened. We have demonstrated that two thirds of estuarine water samples analysed underwent between 5% and 40% evaporation. This previously unreported degree of evaporation in estuaries has important implications for any processes that is effected by the consequent degree of elevated solute concentration.