bluuebunny/crossref_metadata_2025 huggingface dataset:
COMP-1 promotes competitive advantage of nematode sperm
Authors: Hansen Jody M , Chavez Daniela R , Stanfield Gillian M
Published: March 2015

Competition among sperm to fertilize oocytes is a ubiquitous feature of sexual reproduction as well as a profoundly important aspect of sexual selection. However, little is known about the cellular mechanisms sperm use to gain competitive advantage or how these mechanisms are regulated genetically. In this study, we utilize a forward genetic screen in Caenorhabditis elegans to identify a gene, comp-1, whose function is specifically required in competitive contexts. We show that comp-1 functions in sperm to modulate their migration through and localization within the reproductive tract, thereby promoting their access to oocytes. Contrary to previously described models, comp-1 mutant sperm show no defects in size or velocity, thereby defining a novel pathway for preferential usage. Our results indicate not only that sperm functional traits can influence the outcome of sperm competition, but also that these traits can be modulated in a context-dependent manner depending on the presence of competing sperm.
Intersections in delta development; analyzing actors for complexity-sensitive spatial concepts
Authors: Pel Bonno , Van Popering-Verkerk Jitske , Van Buuren Arwin , Edelenbos Jurian
Published: March 2015

Delta areas can be considered complex adaptive socio-ecological systems. The Dutch Southwest delta, facing serious flood risks, vulnerability to ecological decline, and various challenging issues of agriculture, industry, harbor development and energy provision, is a case in point. Still, many institutional barriers exist towards governing and planning this complex whole as such. In this article we therefore develop and test a method for the development of integrative, complexity-sensitive spatial concepts: First, stakeholder analysis techniques are used to disclose the diversity of system understandings amongst the actors involved. Moreover, the method mobilizes these constructivist techniques to gain insight into the CAS property of co-evolving subsystems. Through the subsequent inventory, classification and synthesis of such ‘intersections’ between subsystems, the method helps identify the delta’s crucial clusters of interdependent subsystems, or ‘configurations’. We present three of such configurations, to illustrate how this method informs the step from systems analysis to spatial design.
A global model for cave ventilation and seasonal bias in speleothem paleoclimate records
Authors: James Eric W. , Banner Jay L. , Hardt Benjamin
Published: March 2015

Cave calcite deposits (speleothems) provide long and continuous records of paleoenvironmental conditions in terrestrial settings. Typical environmental proxy measurements include speleothem growth rate and variations in elemental and isotope geochemistry. Commonly the assumption is made that speleothems grow continuously and at a constant rate throughout the year. However, seasonal variation of growth rate may be the rule in many caves. Here we apply observations of modern calcite growth and cave‐air CO2 concentrations and a model of factors controlling cave ventilation to construct a global model predicting where cave calcite growth may be seasonal. Previous models and measurements of calcite precipitation in caves demonstrate the retardation of speleothem growth by high cave‐air CO2. Elevated CO2 is commonly dissipated by ventilation driven by density differences between cave and surface air. Seasonal cycles in atmospheric temperature, pressure, and humidity commonly drive these density contrasts. Modeling these changes latitudinally and globally indicates a geographic control on seasonal cave ventilation and thus on a principal controlling factor of speleothem growth. The model predicts that given constant water, calcium, and CO2 inputs, speleothems from temperate to boreal continental regions commonly accumulate more calcite in the cool season and less or none in the warm season. These models predict that proxies from temperate to boreal speleothems may be seasonally biased due to seasonal ventilation, whereas tropical and maritime records should not.
Natural remanent magnetization acquisition in bioturbated sediment: General theory and implications for relative paleointensity reconstructions
Authors: Egli R. , Zhao X.
Published: March 2015

We present a general theory for the acquisition of natural remanent magnetizations (NRM) in sediment under the influence of (a) magnetic torques, (b) randomizing torques, and (c) torques resulting from interaction forces. Dynamic equilibrium between (a) and (b) in the water column and at the sediment‐water interface generates a detrital remanent magnetization (DRM), while much stronger randomizing torques may be provided by bioturbation inside the mixed layer. These generate a so‐called mixed remanent magnetization (MRM), which is stabilized by mechanical interaction forces. During the time required to cross the surface mixed layer, DRM is lost and MRM is acquired at a rate that depends on bioturbation intensity. Both processes are governed by a MRM lock‐in function. The final NRM intensity is controlled mainly by a single parameter γ that is defined as the product of rotational diffusion and mixed‐layer thickness, divided by sedimentation rate. This parameter defines three regimes: (1) slow mixing (γ < 0.2) leading to DRM preservation and insignificant MRM acquisition, (2) fast mixing (γ > 10) with MRM acquisition and full DRM randomization, and (3) intermediate mixing. Because the acquisition efficiency of DRM is larger than that of MRM, NRM intensity is particularly sensitive to γ in case of mixed regimes, generating variable NRM acquisition efficiencies. This model explains (1) lock‐in delays that can be matched with empirical reconstructions from paleomagnetic records, (2) the existence of small lock‐in depths that lead to DRM preservation, (3) specific NRM acquisition efficiencies of magnetofossil‐rich sediments, and (4) some relative paleointensity artifacts.
North‐south asymmetry in global distribution of the solar wind speed during 1985–2013
Authors: Tokumaru Munetoshi , Fujiki Ken'ichi , Iju Tomoya
Published: March 2015

Interplanetary scintillation (IPS) observations made between 1985 and 2013 are used to investigate the north‐south (N‐S) asymmetry in global distribution of the solar wind speed. The IPS observations clearly demonstrate that the global distribution of the solar wind speed systematically changes with the solar activity. This change is found to closely correlate with that in polar magnetic fields of the Sun, while fast wind data at solar minima systematically deviate from this correlation. The IPS observations show that notable N‐S asymmetry of polar solar winds occurs at the solar maxima, and small but significant N‐S asymmetry exists at the solar minima. The observed asymmetry at the solar maxima is consistent with the time lag in the reversal of polar magnetic fields between north and south hemispheres. We also find that significant N‐S asymmetry of the polar fast wind lasts for the period between Cycles 23 and 24 solar maxima, starting from predominance of the fast wind over the north pole and ending with that over the south pole. The N‐S asymmetry revealed from IPS observations is found to be generally consistent with Ulysses observations. We compare IPS observations with magnetic field data of the Sun and find that the ratio of the quadrupole to dipole coefficients exhibits a similar time variation to that of the N‐S asymmetry revealed from IPS observations. This suggests that higher‐order multipole moments play an important role in determining the N‐S asymmetry of the solar wind when the dipole moment weakens.
U‐Pb dating of interspersed gabbroic magmatism and hydrothermal metamorphism during lower crustal accretion, Vema lithospheric section, Mid‐Atlantic Ridge
Authors: Rioux Matthew , Jöns Niels , Bowring Samuel , Lissenberg C. Johan , Bach Wolfgang , Kylander‐Clark Andrew , Hacker Bradley , Dudás Frank
Published: March 2015

New U/Pb analyses of zircon and xenotime constrain the timing of magmatism, magmatic assimilation, and hydrothermal metamorphism during formation of the lower crust at the Mid‐Atlantic Ridge. The studied sample is an altered gabbro from the Vema lithospheric section (11°N). Primary gabbroic minerals have been almost completely replaced by multiple hydrothermal overprints: cummingtonitic amphibole and albite formed during high‐temperature hydration reactions and are overgrown first by kerolite and then prehnite and chlorite. In a previous study, clear inclusion‐free zircons from the sample yielded Th‐corrected 206Pb/238U dates of 13.528 ± 0.101 to 13.353 ± 0.057 Ma. Ti concentrations, reported here, zoning patterns and calculated Th/U of the dated grains are consistent with these zircons having grown during igneous crystallization. To determine the timing of hydrothermal metamorphism, we dated a second population of zircons, with ubiquitous <1–20 µm chlorite inclusions, and xenotimes that postdate formation of metamorphic albite. The textures and inclusions of the inclusion‐rich zircons suggest that they formed by coupled dissolution‐reprecipitation of metastable igneous zircon during or following hydrothermal metamorphism. Th‐corrected 206Pb/238U dates for the inclusion‐rich zircons range from 13.598 ± 0.012 to 13.503 ± 0.018 Ma and predate crystallization of all but one of the inclusion‐free zircons, suggesting that the inclusion‐rich zircons were assimilated from older hydrothermally altered wall rocks. The xenotime dates are sensitive to the Th correction applied, but even using a maximum correction, 206Pb/238U dates range from 13.341 ± 0.162 to 12.993 ± 0.055 Ma and postdate crystallization of both the inclusion‐rich zircons and inclusion‐free igneous zircons, reflecting a second hydrothermal event. The data provide evidence for alternating magmatism and hydrothermal metamorphism at or near the ridge axis during accretion of the lower crust at a ridge‐transform intersection and suggest that hydrothermally altered crust was assimilated into younger gabbroic magmas. The results of this study show that high‐precision U‐Pb dating is a powerful method for studying the timing of magmatic and hydrothermal processes at mid‐ocean ridges.
Estimating daily climatologies for climate indices derived from climate model data and observations
Authors: Mahlstein Irina , Spirig Christoph , Liniger Mark A. , Appenzeller Christof
Published: March 2015

Climate indices help to describe the past, present, and the future climate. They are usually closer related to possible impacts and are therefore more illustrative to users than simple climate means. Indices are often based on daily data series and thresholds. It is shown that the percentile‐based thresholds are sensitive to the method of computation, and so are the climatological daily mean and the daily standard deviation, which are used for bias corrections of daily climate model data. Sample size issues of either the observed reference period or the model data lead to uncertainties in these estimations. A large number of past ensemble seasonal forecasts, called hindcasts, is used to explore these sampling uncertainties and to compare two different approaches. Based on a perfect model approach it is shown that a fitting approach can improve substantially the estimates of daily climatologies of percentile‐based thresholds over land areas, as well as the mean and the variability. These improvements are relevant for bias removal in long‐range forecasts or predictions of climate indices based on percentile thresholds. But also for climate change studies, the method shows potential for use.
Dissolved organic carbon lability increases with water residence time in the alluvial aquifer of a river floodplain ecosystem
Authors: Helton Ashley M. , Wright Meredith S. , Bernhardt Emily S. , Poole Geoffrey C. , Cory Rose M. , Stanford Jack A.
Published: March 2015

We assessed spatial and temporal patterns of dissolved organic carbon (DOC) lability and composition throughout the alluvial aquifer of the 16 km2 Nyack Floodplain in northwest Montana, USA. Water influx to the aquifer derives almost exclusively from the Middle Fork of the Flathead River, and water residence times within the aquifer range from days to months. Across seasons and channel discharge conditions, we measured DOC concentration, lability, and optical properties of aquifer water sampled from 12 wells, both near and ~3 m below the water table. Concentrations of DOC were typically low (542 ± 22.7 µg L−1; mean ± se), and the percentage of labile DOC averaged 18 ± 12% during 3 day laboratory assays. Parallel factor analysis of fluorescence excitation‐emission matrices revealed two humic‐like and two amino acid‐like fluorescence groups. Total DOC, humic‐like components, and specific UV absorbance decreased with water residence time, consistent with sorption to aquifer sediments. However, labile DOC (both concentration and fraction) increased with water residence time, suggesting a concurrent influx or production of labile DOC. Thus, although the carbon‐poor, oxygen‐rich aquifer is a net sink for DOC, recalcitrant DOC appears to be replaced with more labile DOC along aquifer flow paths. Our observation of DOC production in long flow paths contrasts with studies of hyporheic DOC consumption along short (centimeters to meters) flow paths and highlights the importance of understanding the role of labile organic matter production and/or influx in alluvial aquifer carbon cycling.
Revisiting the hemispheric asymmetry in midlatitude ozone changes following the Mount Pinatubo eruption: A 3‐D model study
Authors: Dhomse S. S. , Chipperfield M. P. , Feng W. , Hossaini R. , Mann G. W. , Santee M. L.
Published: March 2015

Following the eruption of Mount Pinatubo, satellite and in situ measurements showed a large enhancement in stratospheric aerosol in both hemispheres, but significant midlatitude column O3 depletion was observed only in the north. We use a three‐dimensional chemical transport model to determine the mechanisms behind this hemispheric asymmetry. The model, forced by European Centre for Medium‐Range Weather Forecasts ERA‐Interim reanalyses and updated aerosol surface area density, successfully simulates observed large column NO2 decreases and the different extents of ozone depletion in the two hemispheres. The chemical ozone loss is similar in the Northern (NH) and Southern Hemispheres (SH), but the contrasting role of dynamics increases the depletion in the NH and decreases it in the SH. The relevant SH dynamics are not captured as well by earlier ERA‐40 reanalyses. Overall, the smaller SH column O3 depletion can be attributed to dynamical variability and smaller SH background lower stratosphere O3 concentrations.
Statistical precipitation bias correction of gridded model data using point measurements
Authors: Haerter Jan O. , Eggert Bastian , Moseley Christopher , Piani Claudio , Berg Peter
Published: March 2015

It is well known that climate model output data cannot be used directly as input to impact models, e.g., hydrology models, due to climate model errors. Recently, it has become customary to apply statistical bias correction to achieve better statistical correspondence to observational data. As climate model output should be interpreted as the space‐time average over a given model grid box and output time step, the status quo in bias correction is to employ matching gridded observational data to yield optimal results. Here we show that when gridded observational data are not available, statistical bias correction can be carried out using point measurements, e.g., rain gauges. Our nonparametric method, which we call scale‐adapted statistical bias correction (SABC), is achieved by data aggregation of either the available modeled or gauge data. SABC is a straightforward application of the well‐known Taylor hypothesis of frozen turbulence. Using climate model and rain gauge data, we show that SABC performs significantly better than equal‐time period statistical bias correction.
Saturn's giant storm and global radiant energy
Authors: Li Liming , Jiang Xun , Trammell Harold J. , Pan Yefeng , Hernandez Joseph , Conrath Barney J. , Gierasch Peter J. , Achterberg Richard K. , Nixon Conor A. , Flasar F. Michael , Perez‐Hoyos Santiago , West Robert A. , Baines Kevin H. , Knowles Benjamin
Published: March 2015

We analyze the relationship between Saturn's radiant energies and the 2010 giant storm with the Cassini observations. The storm increased the emitted power in a wide latitudinal band (20–55°N) with a maximum change of 9.2 ± 0.1% around 45°N from 2010 to 2011. Such a regional change caused the global‐average emitted power to increase by ~2.0 ± 0.2%. Saturn's giant storm occurs quasiperiodically (i.e., period approximately one Saturnian year), so it is possible that giant storms continuously modify the emitted power if the storm modification has a lifetime close to one Saturnian year. The hemispheric‐average emitted power in the southern hemisphere, which was mainly affected by the seasonal change, decreased by 8.5 ± 0.3% from 2004 to 2013. Our estimates also imply that the 2010 giant storm significantly modified the absorbed solar power of Saturn. The significant temporal variations of radiant powers should be considered in reexamining the value of Saturn's internal heat flux.
Papillomaviruses
Authors: Roberts Sally
Published: March 2015

Papillomaviruses are a large family of small deoxyribonucleic acid (DNA) tumour viruses that cause hyperproliferative warts of cutaneous and mucosal epithelium. These viruses are ubiquitous in the animal kingdom and infect reptiles, birds and mammals and probably originated 350 million years ago. Subsets of human papillomaviruses (HPVs), referred to as ‘high‐risk’ types are associated with anogenital cancers (uterine cervix, vulva, vagina, anus, penis), oropharyngeal cancers and skin cancers. The papillomavirus life cycle is strictly dependent on the terminal differentiation programme of the host cell – the keratinocyte. The virus deregulates host cell cycle control and inactivates the host cells' antiproliferative response in order to reprogramme the differentiating cells to support viral replication. In the case of high‐risk viruses, this is achieved by interactions with important tumour repressor pathways. Two prophylactic vaccines (Gardasil and Cervarix) are available to control infection by the most prevalent HPV types found in anogenital and oropharyngeal cancers.

Key Concepts

Papillomaviruses show strong species and tissue restriction and they share a similar genetic organisation.

Papillomaviruses are small double‐stranded (ds) DNA viruses that replicate as non‐integrated episomes in keratinocytes and are dependent on the keratinocyte undergoing terminal differentiation in order to complete their life cycle.

Low‐risk viruses such as HPV6 and 11 are associated with the formation of anogenital warts and laryngeal papillomaviruses that have a low risk of progression to cancer.

The most severe impact of human papillomavirus infection is the progression of a small proportion of infections to anogenital, oropharyngeal and skin cancers.

High‐risk viruses such as HPV16 and 18 are associated with infections of the mucosa lining the anogenital and oropharyngeal tract and HPV16 is the most prevalent genotype in cancers arising at these sites.

A majority of HPV infections are naturally eliminated by host‐cell‐mediated immunity and HPV infections are especially common in immunocompromised individuals (e.g. HIV‐infected patients, organ‐recipient patients, predisposing genetic conditions, e.g. epidermodysplasia verruciformis).

These viruses are a common sexually transmitted disease (STD) and infection in the oropharynx is most likely via an oral‐genital route.

High‐risk HPV early proteins E5, E6 and E7 are oncoproteins and the expression of E6 and E7 is retained in all cancers; E6 and E7 deregulate tumour suppressor pathways leading to host genomic instability.

Papillomaviruses replicate as extrachromosomal plasmids in the nulei of infected cells, but during cancer progression, the viral genome often becomes integrated into the host chromosome, resulting in a loss of the negative feedback control of viral oncogene expression by E2.

Prophylactic vaccines protect against infection with vaccine‐associated HPV types by inducing neutralising antibodies that recognise epitopes on the major capsid protein.
Regeneration of Vertebrate Tissues: Model Systems
Authors: Stocum David L
Published: March 2015

Vertebrate animals exhibit four mechanisms of tissue regeneration: re‐growth of cellular parts, such as nerve axons; lineage‐specific proliferation of differentiated cells with or without dedifferentiation; transdifferentiation and activation of adult stem cells. The most common mechanism is the proliferation and differentiation of adult stem cells, used by epithelia, muscle, bone and blood. In some cases, such as the liver and pancreas, regeneration is accomplished by either lineage‐specific proliferation of differentiated cells or a stem cell population, depending on the nature of the damage. All four mechanisms are used by urodele salamanders in the regeneration of limbs. The cellular activities in all these mechanisms are regulated by a wide variety of growth factor signalling pathways and transcription factors. Regenerative medicine uses three major strategies based on knowledge of regenerative mechanisms: transplants of stem cells or their derivatives, construction of bioartificial tissues composed of natural or synthetic biomaterials seeded with cells and the pharmaceutical induction of regeneration at the site of injury by natural or synthetic regeneration‐promoting molecules.

Key Concepts

Regeneration restores the original structure and function of damaged or missing tissues.

Tissues use four mechanisms to regenerate: re‐growth of cell parts, lineage‐specific reproduction of parent cells, transdifferentiation and activation of adult stem cells.

Some tissues use more than one mechanism of regeneration.

Growth factor signals and transcription factors are important regulators of regeneration.

Regenerative medicine uses three strategies to regenerate damaged tissues: cell transplants, bioartificial tissue implants and pharmaceutical induction of regeneration directly at the site of damage by scaffolds or soluble molecules.

The source of cells for transplants and bioartificial tissues is a crucial issue for regenerative medicine.

Induced pluripotent stem cells (iPSCs) and/or transdifferentiation may solve many of the problems presented by adult and embryonic stem cells.
Protein–
DNA
Interactions
Authors: Rooman Marianne , Wintjens René
Published: March 2015

The control of the information stored in the genome is managed by DNA‐binding proteins, which are therefore of fundamental importance to cellular life. A wide diversity of such proteins, exhibiting various DNA‐binding modes, specificities and functions, is observed in living organisms. We start by describing the various roles that are played by DNA‐binding proteins, from transcription regulation to DNA repair, and review the types of molecular interactions that stabilise the protein–DNA complexes. We also describe the main structural DNA‐binding protein motifs, among which are the well‐known HTH (helix‐turn‐helix) motifs and zinc fingers, that are recurrently observed in proteins of various functions and origin. Finally, we discuss the different ways in which proteins acquire their specificity for a given DNA sequence, conformation and/or topology.

Key Concepts

DNA‐binding proteins have a fundamental role in the maintenance of genetic material and in the regulation of gene expression.

Most DNA‐binding proteins bind DNA through recurrent structural motifs.

The protein–DNA affinity is achieved through non‐specific interactions between amino acids and the DNA backbone and through specific interactions between amino acids and DNA bases.

Some proteins recognise specific DNA sequences owing to favourable direct interactions between amino acids and nucleobases.

Some proteins recognise specific local or global DNA conformations or topologies.
Protein Motifs: Zinc Fingers
Authors: Meyer Sandra , Kieffer Bruno
Published: March 2015

Zinc is a catalytic, structural and regulatory ion involved in a wide variety of biological processes. It is essential for stabilising the fold of biomolecules called ‘zinc finger’, a term that originates from the finding of the particular organisation of zinc coordinating amino‐acids in the primary sequence of the TFIIIA transcription factor. Zinc fingers currently designate a vast family of protein domains and folds found in proteins involved in both protein–nucleic acids and protein–protein interactions. The variety of folds stabilised by zinc as well as genome sequence analysis suggests that zinc has played an important role in the evolution of the proteome. The modular structure of zinc fingers allowed the design of very specific DNA‐ and RNA‐binding proteins opening a wide range of applications such as artificial nucleases or transcription factors.

Key Concepts

Zinc fingers are small folded protein domains, involved in numerous biological processes.

Zinc coordination by proteins allowed the evolution of a wide variety of folds.

Zinc ions have a wide range of affinities for proteins zinc‐binding sites, allowing metal exchange.

Zinc fingers are involved in protein–protein and protein–DNA interactions.

The rules underlying the specific recognition of DNA sequences by C2H2 zinc fingers are known, enabling the design of artificial DNA enzymes.
Gambling: Pathological Decision‐Making
Authors: Tobias‐Webb Juliette , Clark Luke
Published: March 2015

Gambling is an instance of risky decision‐making where money is staked on the uncertain prospect of a larger outcome. While commercial gambling is widely recognised to have a negative expected value (generated by the ‘house edge’), gambling is highly prevalent in most countries. It is also a behaviour that becomes dysfunctional for a minority of gamblers, and ‘gambling disorder’ is conceptualised as a form of behavioural addiction. Psychological theories of gambling should explain both the sheer existence of this behaviour within human decision‐making and its potential to become addictive. Contemporary approaches are considered, drawing upon conditioning, cognitive psychology, relevant personality variables and underlying neurobiology.

Key Concepts

Gambling is a prevalent form of recreational risk‐taking.

Gambling disorder has been reclassified recently as an addictive disorder in the DSM‐5 and is thereby the first recognised behavioural addiction.

Motivational and cognitive accounts propose that gambling disorder is acquired and maintained through reinforcement learning and distorted beliefs about the probability of events.

Impulsivity is a risk factor for gambling disorder, supported by prospective research.

Neurobiological studies support the overlap between gambling disorder and substance use disorders, with characteristic changes in dopamine and the brain reward system.
Bacteriophages and Food Safety
Authors: Woolston Joelle , Sulakvelidze Alexander
Published: March 2015

Interest in using bacteriophages to improve food safety has been gaining momentum recently, driven by both the continued occurrence of foodborne outbreaks worldwide and the desire of consumers for natural foods. Bacteriophages are naturally part of the normal microflora of many foods, and the ‘phage biocontrol’ approach is based on the concept of using the right phage, in the right place, in the right concentration to control foodborne pathogens. This approach has been applied to three main areas of food safety: (1) pre‐harvest treatment of livestock, (2) decontamination of inanimate surfaces in the processing environment and (3) post‐harvest treatment (i.e. direct food applications). The last type of intervention has perhaps received the most attention, with an increasing number of studies supporting the idea that bacteriophages may provide a safe, environmentally friendly and effective approach for improving food safety, by significantly reducing contamination of various foods with specific foodborne bacterial pathogens.

Key Concepts

Bacteriophages may provide a safe, environmentally friendly and effective approach for significantly reducing contamination of various foods with foodborne bacterial pathogens.

Several bacteriophage products are commercially available for use in pre‐harvest applications, on food contact surfaces and for direct food (post‐harvest) applications.

Bacteriophages are specific; they kill the target pathogen and do not affect the natural microflora of foods.

Bacteriophages can reduce levels of bacterial pathogens on food contact surfaces in as little as 5‐min contact time.

Bacteriophages can reduce levels of the targeted bacterial pathogen on a variety of foods, including, but not limited to, dairy products, fruits and vegetables and poultry.
Preparation of Starch‐Based Bionanocomposite Hydrogel with Mica for Fire Retardancy
Authors: Mallick Bipra Narayan , Rana Pradeep Kumar , Sahoo Prafulla Kumar
Published: March 2015

We know that starch is formed from granules separated from each other. When grafted with butyl acrylate (BA), those granules became more in contact and coherent to formed a merged network‐like spongy structure, which upholds a large amount of water to show improved water absorbency. BA was grafted onto starch to obtain a novel starch‐g‐poly(butyl acrylate) (PBA) biocopolymer hydrogel and formed a bionanocomposite hydrogel with mica as the additive for fire retardancy and was characterized by FTIR, SEM, and TGA. The insertion of mica into the starch‐g‐PBA exhibited an intercalated structure as confirmed by XRD and TEM analyses and also supported the hydrogel as a bionanocomposite, which showed an improved water absorbency and biodegradability with a better thermal stability. Cone calorimetric analysis evaluated the pronounced fire retardancy of the novel starch‐g‐PBA/mica bionanocomposite, providing an excellent protection in delaying the ignition time with greatest extension of time at a peak heat release rate on exposure to fire.
Effect of Polyethylene Glycol on Bis(2‐hydroxyethyl) terephthalate‐Based Polyurethane/Alginate pH‐Sensitive Blend for Oral Protein Delivery
Authors: Bhattacharyya Aditi , Mukhopadhyay Piyasi , Pramanik Nilkamal , Kundu Patit P.
Published: March 2015

Polyurethanes (PUs) are synthesized by reacting two polyols, namely bis(2‐hydroxyethyl) terephthalate (BHET) and polyethylene glycol (PEG), taken in four different ratios and hexamethylene diisocyanate, where the polyol content is slightly higher than the stoichiometrically required amount. BHET is obtained by the glycolysis of polyethylene terephthalate waste. The synthesized PUs are blended with sodium alginate in the ratio of 7:3 and then cross‐linked by calcium chloride to get a pH‐sensitive protein (bovine serum albumin, BSA) carrier. X‐ray diffraction patterns of different PU compositions indicate the presence of amorphous phase. The hydroxyl value of OH‐terminated PUs is found to be increasing with increasing amount of PEG in the composition. PEGylated PU shows higher water uptake and protection against hemolysis with a rising amount of PEG in the PU. Fourier transform infrared spectroscopy of the blend shows characteristic peaks for both PU and alginate distinctly, indicating good dispersion of both the polymers. pH responsive swelling behavior in different pH media corresponding to the gastrointestinal tract (pH 1.2 and 7.4) is investigated for all the prepared blends. The minimum degree of swelling is observed for PU with the maximum amount PEG at pH 1.2, whereas the degree of swelling of the same PU significantly increased at pH 7.4. BSA encapsulation efficiency of the blends increases with an increase in PEG content in the PU and varies within the range of 88–99%. The release profile of BSA at pH 7.4 is found to be similar as observed in the swelling study.
Safety and efficacy results of switch from imiglucerase to velaglucerase alfa treatment in patients with type 1 Gaucher disease
Authors: Elstein Deborah , Mehta Atul , Hughes Derralynn A. , Giraldo Pilar , Charrow Joel , Smith Laurie , Shankar Suma P. , Hangartner Thomas N. , Kunes Yune , Wang Nan , Crombez Eric , Zimran Ari
Published: March 2015

Gaucher disease (GD) is a lysosomal storage disorder; symptomatic patients with type 1 GD need long‐term disease‐specific therapy of which the standard of care has been enzyme replacement therapy (ERT). Thirty‐eight of 40 patients (aged 9–71 years) clinically stable on ERT with imiglucerase, safely switched to a comparable dose of velaglucerase alfa (units/kg) during TKT034, a 12‐month, open‐label clinical study, and for 10–50 months in an extension study. The most common adverse events (AEs) judged to be drug‐related in the extension were fatigue and bone pain. No drug‐related serious AEs were reported. No AEs led to study withdrawal. At 24 months from baseline (baseline being TKT034 week 0), patients had generally stable hemoglobin, platelet, spleen, liver, and bone density parameters. Nevertheless, dose adjustment based on the achievement of therapeutic goals was permitted, and 10 patients, including seven patients who had platelet counts <100 × 109/L at baseline, were given at least one 15 U/kg‐dose increase during the extension. Trends indicative of improvement in platelet count and spleen volume, and decreasing levels of GD biomarkers, chitotriosidase and CCL18, were observed. Immunogenicity was seen in one patient positive for anti‐imiglucerase antibodies at baseline. This patient tested positive for anti‐velaglucerase alfa antibodies in TKT034, with low antibody concentrations, and throughout the extension study; however, the patient continued to receive velaglucerase alfa without clinical deterioration. In conclusion, clinically stable patients can be switched from imiglucerase to velaglucerase alfa ERT and maintain or achieve good therapeutic outcomes. Am. J. Hematol. 90:592–597, 2015. © 2015 Wiley Periodicals, Inc.
Routine conventional karyotyping of lymphoma staging bone marrow samples does not contribute clinically relevant information
Authors: Nardi Valentina , Pulluqi Olja , Abramson Jeremy S. , Dal Cin Paola , Hasserjian Robert P.
Published: March 2015

Bone marrow (BM) evaluation is an important part of lymphoma staging, which guides patient management. Although positive staging marrow is defined as morphologically identifiable disease, such samples often also include flow cytometric analysis and conventional karyotyping. Cytogenetic analysis is a labor‐intensive and costly procedure and its utility in this setting is uncertain. We retrospectively reviewed pathological reports of 526 staging marrow specimens in which conventional karyotyping had been performed. All samples originated from a single institution from patients with previously untreated Hodgkin and non‐Hodgkin lymphomas presenting in an extramedullary site. Cytogenetic analysis revealed clonal abnormalities in only eight marrow samples (1.5%), all of which were positive for lymphoma by morphologic evaluation. Flow cytometry showed a small clonal lymphoid population in three of the 443 morphologically negative marrow samples (0.7%). Conventional karyotyping is rarely positive in lymphoma staging marrow samples and, in our cohort, the BM karyotype did not contribute clinically relevant information in the vast majority of cases. Our findings suggest that karyotyping should not be performed routinely on BM samples taken to stage previously diagnosed extramedullary lymphomas unless there is pathological evidence of BM involvement by lymphoma. Am. J. Hematol. 90:529–533, 2015. © 2015 Wiley Periodicals, Inc.
Management of nosocomial scabies, an outbreak of occupational disease
Authors: Jungbauer Frank H.W. , Veenstra‐Kyuchukova Yanka K. , Koeze Jacqueline , KruijtSpanjer Martijn R. , Kardaun Sylvia H.
Published: March 2015

Background The optimal approach to managing institutional scabies outbreaks has yet to be defined. We report on outbreak managements are needed.

Methods We report on a large outbreak of scabies in three acute care wards in a tertiary university teaching hospital in the Netherlands.

Results The outbreak potentially effected 460 patients and 185 health care workers who had been exposed to the index patient.

Conclusion Containment of an outbreak relies on a quick and strict implementation of appropriate infection control measures and should include simultaneous treatment of all infested persons and exposed contacts to prevent secondary spread and prolonged post‐intervention surveillance. Am. J. Ind. Med. 58:577–582, 2015. © 2015 Wiley Periodicals, Inc.
Synthesis of Billard–Langlois Reagents and their Derivatives by Copper‐Catalyzed N‐Trifluoromethylthiolation of Arylamines with a Trifluoromethanesulfonyl Hypervalent Iodonium Ylide
Authors: Huang Zhongyan , Yang Yu‐Dong , Tokunaga Etsuko , Shibata Norio
Published: March 2015

A one‐step synthesis of Billard–Langlois reagents and their derivatives, trifluoromethanesulfenamides, is reported. A series of primary and secondly arylamines were directly N−H trifluoromethylthiolated by a trifluoromethanesulfonyl hypervalent iodonium ylide under mild, copper‐catalyzed reaction conditions in high yields. Heteroaromatic amines were also successfully trifluoromethylthiolated under the same reaction conditions. An arylamine with an NH‐pyrrole moiety was chemoselectively N‐trifluoromethylthiolated.
Chronic rhinosinusitis and cystic fibrosis: the interaction between sinus bacteria and mucosal immunity
Authors: Kim Raymond J.T. , Park Lydia , Wood Andrew J. , Yin Tary , Jain Ravi , Douglas Richard G.
Published: March 2015

Background

Chronic rhinosinusitis (CRS) is highly prevalent in cystic fibrosis (CF) patients, in whom a close correlation exists between the microbiology of the upper and lower respiratory tracts. We have reported intramucosal bacterial microcolonies in the sinus mucosa from idiopathic CRS patients and have made observations suggesting that these may result from mucosal immunotolerance secondary to altered macrophage function. In this study, we sought to determine whether intramucosal microcolonies exist in the mucosa of CF patients with CRS, and to investigate the associated mucosal immunology.

Methods

Mucus swabs and tissue biopsies were taken from 9 patients with CF undergoing functional endoscopic sinus surgery (FESS) for CRS, 11 with idiopathic CRS undergoing FESS, and 9 with normal sinuses having transnasal pituitary surgery. Microbiology samples were taken for culture and intramucosal microcolonies were sought using Gram staining. Mucosal immune cells were identified using fluorescent immunohistochemistry.

Results

Positive culture rates were similar between CRS patients and controls, but there were significantly more intramucosal microcolonies in the CRS groups (8/9 CF‐CRS, 7/11 CRS), compared to controls (1/9). Furthermore, the biodensity of intramucosal microcolonies was significantly higher in CF‐CRS than idiopathic CRS. Mirroring the microbiological observations, the number of CD163+ macrophages was significantly increased in CF‐CRS compared to idiopathic CRS (p = 0.03).

Conclusion

Intramucosal bacteria exist within the sinus mucosa of patients with CF, and in significantly greater numbers than in idiopathic CRS patients. We speculate that intramucosal microcolonies may also exist in the lower respiratory tract mucosa in CF and play a role in disease recalcitrance.
Management of advanced intracranial intradural juvenile nasopharyngeal angiofibroma: combined single‐stage rhinosurgical and neurosurgical approach
Authors: Naraghi Mohsen , Saberi Hooshang , Mirmohseni Atefeh Sadat , Nikdad Mohammad Sadegh , Afarideh Mohsen
Published: March 2015

Background

Although intracranial extension of juvenile nasopharyngeal angiofibroma (JNA) occurs commonly, intradural penetration is extremely rare. Management of such tumors is a challenging issue in skull‐base surgery, necessitating their removal via combined approaches. In this work, we share our experience in management of extensive intradural JNA.

Methods

In a university hospital–based setting of 2 tertiary care academic centers, retrospective chart of 6 male patients (5 between 15 and 19 years old) was reviewed. Patients presented chiefly with nasal obstruction, epistaxis, and proptosis. One of them was an aggressive recurrent tumor in a 32‐year‐old patient. All cases underwent combined transnasal, transmaxillary, and craniotomy approaches assisted by the use of image‐guided endoscopic surgery, with craniotomy preceding the rhinosurgical approach in 3 cases.

Results

Adding a transcranial approach to the transnasal and transmaxillary endoscopic approaches provided 2‐sided exposure and appreciated access to the huge intradural JNAs. One postoperative cerebrospinal fluid leak and 1 postoperative recurrence at the site of infratemporal fossa were treated successfully. Otherwise, the course was uneventful in the remaining cases.

Conclusion

Management of intracranial intradural JNA requires a multidisciplinary approach of combined open and endoscopic‐assisted rhinosurgery and neurosurgery, because of greater risk for complications during the dissection. Carotid rupture and brain damage remain 2 catastrophic complications that should always be kept in mind. A combined rhinosurgical and neurosurgical approach also has the advantage of very modest cosmetic complications.
Reduction of unexpected serious adverse events after introducing medical emergency team
Authors: Kawaguchi Rui , Nakada Taka‐aki , Oshima Taku , Abe Ryuzo , Matsumura Yosuke , Oda Shigeto
Published: March 2015

Aim

To assess the clinical benefits of introducing a medical emergency team system for early medical intervention in hospital care.

Methods

This prospective analysis included all cases of medical emergency team activation during the first year after the introduction of the medical emergency team system at Chiba University Hospital (Chiba, Japan) in February 2011. The rates of in‐hospital mortality and unexpected events before and after introduction of the medical emergency team system were compared.

Results

The total number of medical emergency team activation calls was 83 (4.9 per 1,000 admissions). The activation of the medical emergency team system was requested most frequently from the general ward (56.6%) and by a physician (57.8%), with the most important reasons for activation being cardiac arrest (37.3%), breathing abnormality (33.7%), and impaired consciousness (32.5%). The most frequent medical interventions by the medical emergency team were intubation (43.3%) and oxygen inhalation (41.0%). Approximately one‐half of the patients requiring activation of the medical emergency team system were critically ill and needed subsequent intensive care unit admission. Although no significant difference was observed between the pre‐ and post‐ medical emergency team in‐hospital mortalities (2.1% versus 2.0%, respectively), the incidence rate of serious events significantly decreased (12.4% versus 6.8%, respectively; P = 0.015).

Conclusion

Most patients requiring activation of the medical emergency team system were critically ill and needed emergency treatment at the location of the medical emergency team activation, with subsequent critical care. Although the introduction of the medical emergency team system did not affect the in‐hospital mortality rate, it reduced the incidence of unexpected serious adverse events, suggesting that it may be clinically useful.
Ortho‐Chinonmethide als reaktive Intermediate in asymmetrischen Brønsted‐Säure‐katalysierten Cycloadditionen mit Alkenen mittels exklusiver Aktivierung des Elektrophils
Authors: Hsiao Chien‐Chi , Raja Sadiya , Liao Hsuan‐Hung , Atodiresei Iuliana , Rueping Magnus
Published: March 2015

Ein effizientes Verfahren für die enantioselektive Synthese von chiralen Chromanen mit mehreren Stereozentren wurde entwickelt. Ein chirales Binol‐basiertes N‐Triflylphosphoramid erwies sich dabei als effektiver Katalysator für die In‐situ‐Generierung von ortho‐Chinonmethiden (o‐QMs) und deren nachfolgende Cycloaddition mit nichtaktivierten Alkenen. Diese führte hoch diastereo‐ und enantioselektiv zu Chromanen.
Flipping a G‐Tetrad in a Unimolecular Quadruplex Without Affecting Its Global Fold
Authors: Dickerhoff Jonathan , Weisz Klaus
Published: March 2015

A unimolecular G‐quadruplex with a hybrid‐type topology and propeller, diagonal, and lateral loops was examined for its ability to undergo structural changes upon specific modifications. Substituting 2′‐deoxy‐2′‐fluoro analogues with a propensity to adopt an anti glycosidic conformation for two or three guanine deoxyribonucleosides in syn positions of the 5′‐terminal G‐tetrad significantly alters the CD spectral signature of the quadruplex. An NMR analysis reveals a polarity switch of the whole tetrad with glycosidic conformational changes detected for all four guanine nucleosides in the modified sequence. As no additional rearrangement of the overall fold occurs, a novel type of G‐quadruplex is formed with guanosines in the four columnar G‐tracts lined up in either an all‐syn or an all‐anti glycosidic conformation.
Enantioselektive intramolekulare Hydroacylierung von nichtaktivierten Alkenen: robuste und vielseitige NHC‐katalysierte Bildung von cyclischen chiralen Ketonen
Authors: Janssen‐Müller Daniel , Schedler Michael , Fleige Mirco , Daniliuc Constantin G. , Glorius Frank
Published: March 2015

Eine enantioselektive intramolekulare Hydroacylierung mit einem N‐heterocyclischen Carben (NHC) als Katalysator ermöglicht die Bildung von cyclischen Ketonen aus nichtaktivierten Olefin‐substituierten Aldehyden (bis zu 99 % ee). Darüber hinaus wurden zum ersten Mal aliphatische Aldehyde in einer effizienten NHC‐katalysierten Hydroacylierung eingesetzt.
Tandem Catalytic C(sp3)H Amination/Sila‐Sonogashira–Hagihara Coupling Reactions with Iodine Reagents
Authors: Buendia Julien , Darses Benjamin , Dauban Philippe
Published: March 2015

A new tandem CN and CC bond‐forming reaction has been achieved through RhII/Pd0 catalysis. The sequence first involves an iodine(III) oxidant, then the in situ generated iodine(I) by‐product is used as a coupling partner. The overall process demonstrates the synthetic value of iodoarenes produced in trivalent iodine reagent mediated oxidations.
Mixing Biomimetic Heterodimers of Nucleopeptides to Generate Biocompatible and Biostable Supramolecular Hydrogels
Authors: Yuan Dan , Du Xuewen , Shi Junfeng , Zhou Ning , Zhou Jie , Xu Bing
Published: March 2015

As a new class of biomaterials, most supramolecular hydrogels formed by small peptides require the attachment of long alkyl chains, multiple aromatic groups, or strong electrostatic interactions. Based on the fact that the most abundant protein assemblies in nature are dimeric, we select short peptide sequences from the interface of a heterodimer of proteins with known crystal structure to conjugate with nucleobases to form nucleopeptides. Being driven mainly by hydrogen bonds, the nucleopeptides self‐assemble to form nanofibers, which results in supramolecular hydrogels upon simple mixing of two distinct nucleopeptides in water. Moreover, besides being biocompatible to mammalian cells, the heterodimer of the nucleopeptides exhibit excellent proteolytic resistance against proteinase K. This work illustrates a new and rational approach to create soft biomaterials by a supramolecular hydrogelation triggered by mixing heterodimeric nucleopeptides.