bluuebunny/crossref_metadata_2025 huggingface dataset:
A Paleoenvironmental and Archaeological Model-Based Age Estimate for the Colonization of Hawai’l
Authors: Athens J. Stephen , Rieth Timothy M. , Dye Thomas S.
Published: January 2014

Recent estimates of when Hawai’i was colonized by Polynesians display considerable variability, with dates ranging from about A.D. 800 to 1250. Using high resolution paleoenvironmental coring data and a carefully defined set of archaeological radiocarbon dates, a Bayesian model for initial settlement was constructed. The pollen and charcoal assemblages of the core record made it possible to identify and date the prehuman period and also the start of human settlement using a simple depositional model. The archaeological and paleoenvironmental estimates of the colonization date show a striking convergence, indicating that initial settlement occurred at A.D. 940–1130 at a 95 percent highest posterior density region (HPD), and most probably between A.D. 1000 to 1100, using a 67 percent HPD. This analysis highlights problems that may occur when paleoenvironmental core chronologies are based on bulk soil dates. Further research on the dating of the bones ofRattus exulans, a Polynesian introduction, may refine the dating model, as would archaeological investigations focused on potential early site locations.
Espèces végétales indicatrices des échanges d’eau entre tourbière et aquifère
Authors: Munger Julie L. , Pellerin Stéphanie , Larocque Marie , Ferlatte Miryane
Published: January 2014

Les tourbières jouent plusieurs rôles dans l’hydrologie de surface. Les liens hydrologiques entre les tourbières et les eaux souterraines (aquifères) demeurent toutefois peu connus, ce qui rend les zones d’interaction difficiles à identifier. Ce projet avait pour but d’identifier des espèces et des associations d’espèces floristiques indicatrices de zones d’échanges tourbière-aquifère. Ainsi, des suivis piézométriques et des inventaires floristiques ont été réalisés dans 9 tourbières situées dans le Centre-du-Québec et en Abitibi-Témiscamingue. Les échanges tourbière-aquifère ont été identifiés à l’aide de gradients de charges hydrauliques et les espèces indicatrices à l’aide de l’indice de valeur indicatriceINDVAL. Cette méthode a entre autres permis d’identifier 2 espèces (Carex limosaetSphagnum russowii) et 4 associations d’espèces indicatrices d’un apport en eau souterraine à la tourbière. Les espèces indicatrices pourraient devenir un outil utile, rapide et peu coûteux pour prédire les zones d’interactions tourbière-aquifère et ainsi faciliter la tâche des gestionnaires du territoire.
Les génomes du pin gris et du pin tordu, témoins des bouleversements climatiques passés
Authors: Godbout Julie , Bousquet Jean
Published: January 2014

La phylogéographie est un champ de la biogéographie qui s’appuie sur les outils de la génétique afin de mieux comprendre les conséquences d’évènements anciens sur la répartition de la diversité des espèces. Les aires actuelles de répartition de 2 espèces de pin dur, le pin gris (Pinus banksianaLamb.) et le pin tordu (Pinus contortaDougl. ex. Loud.) étaient presque entièrement recouvertes par l’inlandsis au moment du maximum glaciaire, il y a 21 000 ans. Ces 2 espèces représentent donc d’excellents modèles pour étudier l’effet de la dernière glaciation sur la diversité génétique des espèces et pour la compréhension des mouvements de colonisation qui ont accompagné le réchauffement climatique de l’Holocène. L’utilisation de marqueurs génétiques de l’ADN mitochondrial et chloroplastique a permis de détecter une structure géographique marquée pour chacune des 2 espèces, permettant de mettre en évidence plusieurs éléments du paysage ayant favorisé la différenciation génétique de sous-groupes durant l’ère glaciaire. Ces marqueurs ont aussi permis de détecter une introgression naturelle entre ces espèces ainsi que des fluctuations de leurs répartitions au cours de l’Holocène. Les contextes historique, théorique et méthodologique sont aussi abordés de façon à permettre la comparaison avec d’autres espèces du biome boréal.
Alineación entre las evaluaciones externas y los estándares académicos: El Caso de la Prueba Saber de Matemáticas en Colombia.
Authors: Lopez Alexis A.
Published: January 2014

En este estudio se analiza el concepto de alineación presentando los resultados de un estudio que examina el grado de alineación entre una evaluación estandarizada de matemáticas y unos estándares académicos. La alineación se examinó usando el modelo de Webb y los resultados sugieren que el grado de alineación entre las evaluaciones estandarizadas y los estándares académicos no es el más adecuado y por lo tanto los resultados se deben interpretar con mucha cautela y se debe poner mucho cuidado con el tipo de decisiones que se toman con base en los resultados.
Role of aluminum oxide cladding layers in heat transfer in a semiconductor slab with photonic crystal
Authors: Okabe Takashi , Morifuji Masato , Kondow Masahiko
Published: January 2014

To clarify the role of cladding layers in heat transfer in a laser diode fabricated using a photonic crystal, we theoretically investigate heat transfer in a semiconductor slab with a two-dimensional photonic crystal consisting of an array of air holes. For a photonic crystal laser, temperature increase may be a serious problem since air holes can cause poor heat transfer even if a large Q-factor reduces threshold current. We carry out simulations of heat transfer in a structure with AlO
x
layers that are naturally generated by oxidizing conventional AlAs cladding layers. Temperature changes in structures with and without AlO
x
cladding layers show that the AlO
x
cladding layers suppress temperature rise down to about 1/3 of that in the structure without AlO
x
cladding layers.
Bidirectional migration of Au colloids and silicon microrods in liquid using asymmetrical alternating current electric field with insulated electrodes
Authors: Shibata Akihide , Komiya Kenji , Watanabe Keiji , Sato Takuya , Shiomi Takeshi , Kotaki Hiroshi , Schuele Paul J. , Crowder Mark A. , Zhan Changqing , Hartzell John W.
Published: January 2014

In this study, we demonstrate the migration of Au colloids and silicon microrods in deionized (DI) water and isopropyl alcohol (IPA) by applying asymmetrical AC bias to two electrodes capped with a thin dielectric film. Both Au colloids and silicon microrods successfully migrate from one electrode to the other when asymmetrical AC bias is applied to the electrodes. Furthermore, the direction of the migration can be easily reversed by inverting the wave form. The insulated electrodes have the potential to prevent contamination and bubbling originating from electrochemical reactions, which makes the adoption of the technique for mass production processes easy and realistic. The bidirectional migration acts similarly to electrophoresis and is effective even in DI water and IPA in which conventional DC electrophoresis with insulated electrodes is ineffective. This technique is widely applicable to the positional control of small objects including nano- and micro-sized devices.
Global ionospheric total electron contents (TECs) during the last two solar minimum periods
Authors: Jee Geonhwa , Lee Han‐Byul , Solomon Stanley C.
Published: January 2014

The last solar minimum period was anomalously extended and low in EUV irradiance compared with previous solar minima. It can readily be expected that the thermosphere and the ionosphere must be correspondingly affected by this low solar activity. While there have been unanimous reports on the thermospheric changes, being cooler and lower in its density as expected, the ionospheric responses to low solar activity in previous studies were not consistent with each other, probably due to the limited ionospheric observations used for them. In this study, we utilized the measurements of total electron content (TEC) from TOPEX and JASON‐1 satellites during the periods of 1992 to 2010, which includes both the last two solar minimum periods, in order to investigate how the ionosphere responded to the extremely low solar activity during the last solar minimum compared with previous solar minimum. Although the global daily mean TECs show negligible differences between the two solar minimum periods, the global TEC maps reveal that there are significant systematic differences ranging from about −30% to +50% depending on local time, latitude, and season. The systematic variations of the ionospheric responses seem to mainly result from the relative effects of reduced solar EUV production and reduced recombination rate due to thermospheric changes during the last solar minimum period.
Observations of flow variability through the Kerama Gap between the East China Sea and the Northwestern Pacific
Authors: Na Hanna , Wimbush Mark , Park Jae‐Hun , Nakamura Hirohiko , Nishina Ayako
Published: January 2014

The Kerama Gap, near the middle of the Ryukyu Island chain, is the deepest channel with a sill depth of 1050 m connecting the East China Sea (ECS) to the Northwestern Pacific. We measured the flow through the Kerama Gap from June 2009 to June 2011. The 2 year mean transport, 2.0 ± 0.7 Sv, is into the ECS from the Northwestern Pacific; it contributes about 11% of the mean Kuroshio transport in the ECS at the PN line. Subtidal standard deviation of the transport through the Kerama Gap is 3.2 Sv, comparable to that of the PN‐line Kuroshio transport (4.0 Sv), suggesting a significant effect of Kerama Gap transport on temporal variability of the Kuroshio transport in the ECS. Comparison with time series of satellite‐measured sea surface height maps reveals that temporal variability of the Kerama Gap transport is related to the arrival of mesoscale eddies from the east: high (low) transport into the ECS is associated with the presence of a cyclonic (anticyclonic) eddy south of the Kerama Gap.
Bidirectional infrasonic ducts associated with sudden stratospheric warming events
Authors: Assink J. D. , Waxler R. , Smets P. , Evers L. G.
Published: January 2014

In January 2011, the state of the polar vortex in the midlatitudes changed significantly due to a minor sudden stratospheric warming event. As a result, a bidirectional duct for infrasound propagation developed in the middle atmosphere that persisted for 2 weeks. The ducts were due to two zonal wind jets, one between 30 and 50 km and the other around 70 km altitude. In this paper, using microbarom source modeling, a previously unidentified source region in the eastern Mediterranean is identified, besides the more well known microbarom source regions in the Atlantic Ocean. Infrasound data are then presented in which the above mentioned bidirectional duct is observed in microbarom signals recorded at the International Monitoring System station I48TN in Tunisia, from the Mediterranean region to the east and from the Atlantic Ocean to the west. While the frequency bands of the two sources overlap, the Mediterranean signal is coherent up to about 0.6 Hz. This observation is consistent with the microbarom source modeling; the discrepancy in the frequency band is related to differences in the ocean wave spectra for the two basins considered. This work demonstrates the sensitivity of infrasound to stratospheric dynamics and illustrates that the classic paradigm of a unidirectional stratospheric duct for infrasound propagation can be broken during a sudden stratospheric warming event.
How much methane could be released from Arctic hydrates?
Authors: Balcerak Ernie
Published: January 2014

In Arctic seafloor sediments, methane, a potent greenhouse gas, is trapped in chemical structures called hydrates. Methane hydrates form at low‐temperature, high‐pressure conditions, and methane can be released if the temperature rises. Previous studies have raised concern that global climate change could lead to release of significant amounts of methane from Arctic hydrates.
Sensors in the Measurement of Toxic Gases in the Air
Authors: Zhuiykov Serge
Published: January 2014

The use of state‐of‐the‐art chemical sensors for accurate measurement of the toxic gases in air has been increased over the last decade owing to the growing public awareness of the hazards associated with many airborne chemicals, toughening the legislation in various countries toward the reduction of the pollutants' emission and continuous advancements in the development of new measuring concepts and nanomaterials for sensing electrodes (SEs).(1–19)This article provides an overview of the major sensor types with specific examples of the utilization of nanostructured materials for their SEs. Examples of the different sensors and their improved characteristics have been discussed.
Micellar Electrokinetic Chromatography
Authors: Pyell Ute
Published: January 2014

Micellar electrokinetic chromatography (MEKC) is a highly efficient capillary‐format separation technique that is performed with the same experimental setup, which is used with capillary electrophoresis (CE). While the separation principle of CE is based on the differences in the effective electrophoretic mobility of the solutes to be separated (only charged species can be separated), MEKC separation is also based on the differences in the distribution constants between two phases migrating at a different velocity because of electrokinetic effects. In general, the second phase is introduced into the separation electrolyte/background electrolyte (BGE) by adding an ionic surfactant (anionic or cationic) in a concentration above the critical micellar concentration (CMC). Under these conditions, dynamic association colloids (micelles) are formed. These aggregates have an electrophoretic mobility and are able to incorporate solutes or interact strongly with species dissolved in the surrounding medium.

MEKC extends the applicability of CE to neutral solutes. In addition, MEKC has been proven to be superior to CE in the separation of very complex mixtures of solutes with similar electrophoretic mobility because of the various parameters that are available for the manipulation of the separation selectivity. MEKC can be regarded as a separation technique with a similar scope to that of reversed‐phase high‐performance liquid chromatography (RPHPLC) and other modes of high‐performance liquid chromatography HPLC competing with these modes regarding the efficiency of the separation system, separation speed, cost, and tolerance to matrix constituents, as in MEKC, no stationary phase is present, which can be fouled by irreversible sorption of matrix constituents of the sample. Owing to the small injection volume (few nanoliters) and the small detection volume, which is necessary to avoid intolerable instrumental band broadening, there is a strong need for online focusing methods and sensitive miniaturized detection techniques.
Chemical Effects in Hard X‐ray Photon‐In Photon‐Out Spectra
Authors: Hayashi Hisashi
Published: January 2014

Hard X‐ray photon‐in photon‐out techniques are targeted at applications where the sample environment cannot be freely chosen. The resultant X‐ray emission spectra are influenced by the chemical environments of the atoms involved. If high‐resolution measurements are possible, the chemical effects in the X‐ray emission spectra can provide information about the chemical states, complementary to that offered by other X‐ray spectroscopies. X‐ray emission is classified into six categories for convenience: X‐ray diagram lines, X‐ray valence‐band emission, radiative Auger effect, resonant X‐ray emission, Compton scattering, and X‐ray Raman scattering. After a brief description of the history of research on these types of emission, the chemical effects that they reveal and related topics, including high‐resolution absorption measurements and the static structure factor, are reviewed. An overview of the instrumentation employed in both laboratories and synchrotron radiation (SR) facilities is also given.
Free‐Standing Cell Sheet Assembled with Ultrathin Extracellular Matrix as an Innovative Approach for Biomimetic Tissues
Authors: Chen Jun , Qiu Xiaozhong , Wang Leyu , Zhong Wen , Kong Jiming , Xing Malcolm M. Q.
Published: January 2014

Current artificial tissue‐substitutes have limited clinical applications due to unmatched complex combination of cells and extracellular matrix (ECM) as seen in native tissues. From a developmental perspective, the construction of effective biomimetic tissues is from the bottom (one‐dimensional nanoparticles or two‐dimensional membranes) up (three‐dimensional scaffolds or more complex composite). In a hierarchical architecture, each sub‐structure can be assembled in a flexible way with specific regulators and cells, which overcomes the deficiency of one‐for‐all scaffold. Here, a cell‐compatible cell‐lined layered nano‐membrane is developed. Bioactive molecules are mounted on a nano‐membrane and later released to its lined cell sheet. The cell‐lined membrane is in a free‐standing form to regulate cellular functions. The major advantage of this methodology is to provide a versatile approach to construct biomimetic tissues for clinical applications.
The influence of rigid and flexible monomers on the physical‐chemical properties of polyimides
Authors: da Conceição Thiago Ferreira , Felisberti Maria Isabel
Published: January 2014

This article presents the synthesis and characterization of polyimides and copolyimides derived from rigid [4,4′‐(9‐fluorenylidene)dianiline (FNDA) and 3,3′,4,4′‐biphenyltetracarboxylic dianhydride (BPDA)] and flexible segments [4,4′‐(1,3‐phenylenedioxy) dianiline (PDODA) and ethylenediaminetetraacetic dianhydride (EDTAn)], by polyaddition followed by thermal imidization of the polyamic acid. It describes the characterization of the polyimides and the polyamic acids in accordance to 1H NMR, FTIR, GPC, and XRD analysis, as well as solubility, mechanical (DMTA and stress–strain tests), thermal (DSC and TGA), and electric properties. Among the homopolymers, FNDA–BPDA and PDODA–BPDA form free‐standing films. The first presents higher Tg, thermal stability and Young's modulus. To tailor the properties copolyimides of FNDA, PDODA, and BPDA were synthesized. Young's modulus, Tg, thermal stability, dielectric constant, and solubility progressively increase with increasing amount of FNDA. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40351.
We are what we do: Examining learner‐generated content in the anatomy laboratory through the lens of activity theory
Authors: Doubleday Alison F. , Wille Sarah J.
Published: January 2014

Video and photography are often used for delivering content within the anatomical sciences. However, instructors typically produce these resources to provide instructional or procedural information. Although the benefits of learner‐generated content have been explored within educational research, virtually no studies have investigated the use of learner‐generated video and photograph content within anatomy dissection laboratories. This study outlines an activity involving learner‐generated video diaries and learner‐generated photograph assignments produced during anatomy laboratory sessions. The learner‐generated photographs and videos provided instructors with a means of formative assessment and allowed instructors to identify evidence of collaborative behavior in the laboratory. Student questionnaires (n = 21) and interviews (n = 5), as well as in‐class observations, were conducted to examine student perspectives on the laboratory activities. The quantitative and qualitative data were examined using the framework of activity theory to identify contradictions between student expectations of, and engagement with, the activity and the actual experiences of the students. Results indicate that learner‐generated photograph and video content can act as a rich source of data on student learning processes and can be used for formative assessment, for observing collaborative behavior, and as a starting point for class discussions. This study stresses the idea that technology choice for activities must align with instructional goals. This research also highlights the utility of activity theory as a framework for assessing classroom and laboratory activities, demonstrating that this approach can guide the development of laboratory activities. Anat Sci Educ 7: 361–369. © 2014 American Association of Anatomists.
A linker strategy for trans‐FRET assay to determine activation intermediate of NEDDylation cascade
Authors: Malik‐Chaudhry Harbani Kaur , Saavedra Amanda , Liao Jiayu
Published: January 2014

Förster resonance energy transfer (FRET) technology has been widely used in biological and biomedical research and is a valuable tool for elucidating molecular interactions in vitro and in vivo. Quantitative FRET analysis is a powerful method for determining biochemical parameters and molecular distances at nanometer levels. Recently, we reported theoretical developments and experimental procedures for determining the dissociation constant, Kd and enzymatic kinetics parameters, Kcat and KM, of protein interactions with the engineered FRET pair, CyPet and YPet. The strong FRET signal from this pair made these developments possible. However, the direct link of fluorescent proteins with proteins of interests may interfere with the folding of some fusion proteins. Here, we report a new protein engineering strategy for improving FRET signals by adding a linker between the fluorescent protein and the targeted protein. This improvement allowed us to follow the covalent conjugation of NEDD8 to its E2 ligase in the presence of E1 and ATP, which was difficult to determine without linker. Three linkers, LAEAAAKEAA, TSGSPGLQEFGT, and LAAALAAA, which are alpha helix or random coil, all significantly improved the FRET signals. Our results show a general methodology for improving trans‐FRET signals to effectively determine biochemical reaction intermediates. Biotechnol. Bioeng. 2014;111: 1288–1295. © 2014 Wiley Periodicals, Inc.
HER2 overexpression a major risk factor for recurrence in pT1a‐bN0M0 breast cancer: results from a French regional cohort
Authors: Rouanet Philippe , Roger Pascal , Rousseau Emilie , Thibault Severine , Romieu Gilles , Mathieu Andre , Cretin Jacques , Barneon Gilbert , Granier Mireille , Maran‐Gonzalez Aurelie , Daures Jean P. , Boissiere Florence , Bibeau Frederic
Published: January 2014

The management of pT1a‐bN0M0 breast cancer remains an area of controversy. Data from 714 patients classified as having pT1a‐bN0M0 breast cancer and treated, from 1999 to 2004 in the Languedoc‐Roussillon France, were analyzed. The human epidermal growth factor receptor 2 (HER2) status analyses were centralized. The objective of this study was to describe the prognosis of pT1a‐bN0M0 breast cancer according to HER2 distribution and hormonal status. The median follow‐up was 6.4 years. Ten‐year overall survival was 94%. HER2 overexpression was observed in 6.1% of the patients. The 10‐year prognosis of patients with HER2‐positive tumors was worse than that of those with HER2‐negative (disease‐free survival 73% vs. 89%, P < 0.0001). Tumor size (T1a/T1b) was not a relevant prognostic factor. The co‐expression of HER2 with hormonal receptors (HR) was associated with high recurrence at 10 years. In both univariate and multivariate analyses, the most relevant prognostic factor for this population was HER2 amplification. In multivariate analysis, patients with HER2‐positive tumors had higher risk of mortality (HR, 3.89; 95% CI, 1.58–9.56). In pT1a‐bN0M0 breast cancers, HER2 amplification or overexpression is a risk factor for recurrence. In HER2‐positive breast cancers, HR expression is associated with a poor prognosis despite the hormone therapy. For this population, a personalized management may be required.
Isolatable Organophosphorus(III)–Tellurium Heterocycles
Authors: Nordheider Andreas , Chivers Tristram , Schön Oliver , Karaghiosoff Konstantin , Athukorala Arachchige Kasun S. , Slawin Alexandra M. Z. , Woollins J. Derek
Published: January 2014

Invited for the cover of this issue is the group of J. Derek Woollins at the University of St. Andrews. The image shows a burning P4S3 strike‐anywhere matchstick as a representative of the use of an important phosphorus–chalcogen compound together with the key structures discussed in the paper. Read the full text of the article at 10.1002/chem.201303884.
Pharmacokinetics and pharmacodynamics of GSK961081, a novel inhaled muscarinic antagonist β2‐agonist, and fluticasone propionate administered alone, concurrently and as a combination blend formulation in healthy volunteers
Authors: Norris Virginia , Ambery Claire , Riley Trevor
Published: January 2014

Objective

To investigate the pharmacokinetics and pharmacodynamics of inhaled GSK961081 and fluticasone propionate (FP) given alone, concurrently and as a combination blend formulation.

Methods

The study was double‐blind, double‐dummy, four‐way crossover. Twenty‐four healthy volunteers took single doses of the following in randomized order: (1) GSK961081 800 µg; (2) FP 500 µg; (3) GSK961081 800 µg and FP 500 µg as a blend formulation; and (4) GSK961081 800 µg and FP 500 µg concurrently via separate inhalers. The eLung breathing simulator was also used for the in vitro characterization of the formulations.

Results

There was no pharmacokinetic interaction when GSK961081 and FP were administered concurrently. Mean Cmax and AUC(0−t) of GSK961081 were lower (∼20%) and mean Cmax and AUC(0−t) of FP were higher (two fold) following GSK961081/FP blend formulation compared to concurrent or the individual components alone. There was an increase in the FP in vitro ex‐throat dose for the GSK961081/FP blend from the eLung breathing simulator. Serum cortisol suppression was greater with GSK961081/FP blend, with lower (∼10%) cortisol levels than after GSK961081 + FP concurrent or FP alone.

Conclusion

GSK961081/FP blend formulation was associated with an increase in FP systemic exposure and greater serum cortisol suppression.
Language‐like behavior of protein length distribution in proteomes
Authors: Eroglu Sertac
Published: January 2014

In this study, to demonstrate the language‐like behavior of protein length distribution in proteomes, a quantitative linguistic distribution model, Menzerath–Altmann model, was adopted. A total of 10 proteomes from completely sequenced representative organisms (archaea, bacteria, and eukarya domains) were examined. The results showed that the protein length distribution in the complete set of proteomic proteins, or at least in a wide range for each proteome, can be described reasonably well using the distribution model without considering any complex underlying mechanisms. The deliberation of the model parameters confirmed the evolutionary trend and the model parameters were observed to be related to organismal complexity. © 2014 Wiley Periodicals, Inc. Complexity 20: 12–21, 2014
Noise‐tolerant dynamic CMOS circuits design by using true single‐phase clock latching technique
Authors: Wey I‐Chyn , Chang Chun‐Wei , Liao Yu‐Cheng , Chou Heng‐Jui
Published: January 2014

In this paper, a true‐single‐phase clock latching based noise‐tolerant (TSPCL‐NT) design for dynamic CMOS circuits is proposed. A TSPCL‐NT dynamic circuit can isolate and filter noise before the noise enters into the dynamic circuit. Therefore, it cannot only greatly enhance the noise tolerance of dynamic circuits but also release the signal contention between the feedback keeper and the pull‐down network effectively. As a result, noise tolerance of dynamic circuits can be improved with lower sacrifice in power consumption and operating speed. In the 16‐bit TSPCL‐NT Manchester adder, the average noise threshold energy can be enhanced by 3.41 times. In the meanwhile, the power‐delay product can be improved by 5.92% as compared with the state‐of‐the art 16‐bit XOR‐NT Manchester adder design under TSMC 90 nm CMOS process. Copyright © 2014 John Wiley & Sons, Ltd.
Flume‐ and field‐based evaluation of a time‐integrated suspended sediment sampler for the analysis of sediment properties
Authors: Smith Tyler B. , Owens Philip N.
Published: January 2014

Suspended sediment has been identified as a vector for nutrient and contaminant transport in the fluvial environment. A time‐integrated sampler (the Phillips sampler), which emerged over a decade ago as a cost‐effective tool for in situ suspended sediment collection, is increasingly being used to collect samples for the analysis of sediment properties such as particle size composition, and nutrient and contaminant concentrations. This study evaluates the sampler under both flume and field conditions for efficiency in the mass and grain size of the suspended sediment collected. The sampler was tested in a flume using both kaolinite and sediment samples (sieved to < 180 µm) collected from the Quesnel River, British Columbia, Canada. In the kaolinite trails, the sampler preferentially collected coarser grain sizes compared to the original sediment, probably due to finer sediment remaining in suspension and therefore passing through the sampler, and also possibly due to flocculation of the kaolinite upon introduction to the flume. Conversely, the sampler collected river sediment that was finer than the original sediment, probably due to some settling of coarser sediment observed at the bottom of the flume. Once allowance was made for these operational issues associated with the flume, maximum sediment mass efficiency for kaolinite and river sediment was 43% and 87%, respectively. Sediment collected by the time‐integrated sampler during field deployment and adjacent channel bed sediment were also compared. The sampler collected sediment with a representative grain size distribution. However, there were differences in the geochemical (arsenic and selenium) concentrations of channel bed sediment and sediment collected by the Phillips sampler which may be a function of differences in the behavior of geochemical elements associated with the two types of sediment. This work suggests that further research is needed to evaluate the role of the Phillips sampler in collecting sediment for contaminant and nutrient analysis. Copyright © 2014 John Wiley & Sons, Ltd.
Comparison of two hydrogel formulations for drug release in ophthalmic lenses
Authors: Paradiso P. , Galante R. , Santos L. , Alves de Matos A. P. , Colaço R. , Serro A. P. , Saramago B.
Published: January 2014

In the present work two types of polymers were investigated as drug releasing contact lens materials: a poly‐hydroxyethylmethacrylate (pHEMA) based hydrogel and a silicone hydrogel. The silicone hydrogel resulted from the addition of TRIS, a hydrophobic monomer containing silicon (3‐tris(trimethylsilyloxy)silylpropyl 2‐methylprop‐2‐enoate), to pHEMA. Both hydrogels were loaded with an antibiotic (levofloxacin) and an antiseptic (chlorhexidine) by soaking in the drug solutions. The hydrogel properties were determined to be within the range demanded for lens materials. The release profiles of both drugs from the hydrogels were obtained and eventual drug/polymer interactions were assessed with the help of Raman spectra. A mathematical model, developed to mimic the eye conditions, was applied to the experimental results in order to predict the in vivo efficacy of the studied systems. The release profiles were compared with those resulting from the application of commercial eyedrops. The pHEMA based hydrogel demonstrated to be the best material to achieve a controlled release of levofloxacin. In the case of chlorhexidine, the silicone hydrogel seems to lead to better results. In both cases, our results suggest that these materials are adequate for the preparation of daily disposable therapeutic contact lenses. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 1170–1180, 2014.
Chitosan–cellulose composite for wound dressing material. Part 2. Antimicrobial activity, blood absorption ability, and biocompatibility
Authors: Harkins April L. , Duri Simon , Kloth Luther C. , Tran Chieu D.
Published: January 2014

Chitosan (CS), a polysaccharide derived from chitin, the second most abundant polysaccharide, is widely used in the medical world because of its natural and nontoxic properties and its innate ability for antibacterial and hemostasis effects. In this study, the novel composites containing CS and cellulose (CEL) (i.e., [CEL + CS]), which we have previously synthesized using a green and totally recyclable method, were investigated for their antimicrobial activity, absorption of anticoagulated whole blood, anti‐inflammatory activity through the reduction of tumor necrosis factor‐α (TNF‐α) and interleukin‐6 (IL‐6), and the biocompatibility with human fibroblasts. The [CEL + CS] composites were found to inhibit the growth of both Gram positive and negative micro‐organisms. For examples, the regenerated 100% lyophilized chitosan material was found to reduce growth of Escherichia coli (ATCC 8739 and vancomycin resistant Enterococcus faecalis (ATCC 51299) by 78, 36, and 64%, respectively. The composites are nontoxic to fibroblasts; that is, fibroblasts, which are critical to the formation of connective tissue matrix were found to grow and proliferate in the presence of the composites. They effectively absorb blood, and at the same rate and volume as commercially available wound dressings. The composites, in both air‐dried and lyophilized forms, significantly inhibit the production of TNF‐α and IL‐6 by stimulated macrophages. These results clearly indicate that the biodegradable, biocompatible and nontoxic [CEL + CS] composites, particularly those dried by lyophilizing, can be effectively used as a material in wound dressings. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 1199–1206, 2014.
Dependence of Castration‐Resistant Prostate Cancer (CRPC) Stem Cells on CRPC‐Associated Fibroblasts
Authors: Adisetiyo Helty , Liang Mengmeng , Liao Chun‐Peng , Jeong Joseph H. , Cohen Michael B. , Roy‐Burman Pradip , Frenkel Baruch
Published: January 2014

We previously established a role for cancer‐associated fibroblasts (CAF) in enhancing the self‐renewal and differentiation potentials of putative prostate cancer stem cells (CSC). Our published work focused on androgen‐dependent prostate cancer (ADPC) using the conditional Pten deletion mouse model. Employing the same model, we now describe the interaction of CAF and CSC in castration‐resistant prostate cancer (CRPC). CAF isolated from ADPC (ADPCAF) and from CRPC (CRPCAF) were compared in terms of their ability to support organoid formation and tumor initiation by CSC from CRPC (CRPCSC) in vitro and in vivo. CRPCSC formed spheroids in vitro and well‐differentiated glandular structures under the renal capsules of recipient mice in vivo more effectively in the presence of CRPCAF compared to ADPCAF. Furthermore, whereas CSC with CAF from ADPC formed mostly well‐differentiated tumors in our previous study, we now show that CRPCSC, when combined with CRPCAF (but not ADPCAF), can form aggressive, poorly‐differentiated tumors. The potential of CRPCAF to support organoid/tumor formation by CRPCSC remained greater even when compared to 10‐fold more ADPCAF, suggesting that paracrine factors produced specifically by CRPCAF preferentially potentiate the stemness and tumorigenic properties of the corresponding CSC. This apparently unique property of CRPCAF was notable when the CAF and CSC were grafted in either intact or castrated recipient mice. In both environments, CRPCAF induced in the epithelial compartment higher proliferative activity compared to ADPCAF, indicated by a higher Ki67 index. Factors released by CRPCAF to regulate CRPCSC may be targeted to develop novel therapeutic approaches to manage advanced prostate cancer. J. Cell. Physiol. 229: 1170–1176, 2014. © 2014 Wiley Periodicals, Inc.
Non‐Cartesian parallel imaging reconstruction
Authors: Wright Katherine L. , Hamilton Jesse I. , Griswold Mark A. , Gulani Vikas , Seiberlich Nicole
Published: January 2014

Non‐Cartesian parallel imaging has played an important role in reducing data acquisition time in MRI. The use of non‐Cartesian trajectories can enable more efficient coverage of k‐space, which can be leveraged to reduce scan times. These trajectories can be undersampled to achieve even faster scan times, but the resulting images may contain aliasing artifacts. Just as Cartesian parallel imaging can be used to reconstruct images from undersampled Cartesian data, non‐Cartesian parallel imaging methods can mitigate aliasing artifacts by using additional spatial encoding information in the form of the nonhomogeneous sensitivities of multi‐coil phased arrays. This review will begin with an overview of non‐Cartesian k‐space trajectories and their sampling properties, followed by an in‐depth discussion of several selected non‐Cartesian parallel imaging algorithms. Three representative non‐Cartesian parallel imaging methods will be described, including Conjugate Gradient SENSE (CG SENSE), non‐Cartesian generalized autocalibrating partially parallel acquisition (GRAPPA), and Iterative Self‐Consistent Parallel Imaging Reconstruction (SPIRiT). After a discussion of these three techniques, several potential promising clinical applications of non‐Cartesian parallel imaging will be covered. J. Magn. Reson. Imaging 2014;40:1022–1040. © 2014 Wiley Periodicals, Inc.
Metabolomics analysis reveals variation in Schisandra chinensis metabolites from different origins
Authors: Zhang Yinan , Li Fen , Huang Fengjie , Xie Guoxiang , Wei Runmin , Chen Tianlu , Liu Jiajian , Zhao Aihua , Jia Wei
Published: January 2014

Wu Wei Zi (Schisandra chinensis), an important herbal medicine, is mainly distributed in the northeast of China. Its phytochemical compositions, which depend on geographical origin, climatic conditions and cultural practices, may vary largely among Wu Wei Zi from different areas. In this study, we applied a comprehensive metabolite profiling approach using GC–TOF‐MS, ultra‐performance LC (UPLC) quadrupole TOF (QTOF) MS and inductively coupled plasma MS to systematically investigate the metabolite variations of S. chinensis from four different areas including Heilongjiang, Liaoning, Jilin, and Shanxi of China. A total of 65 primary metabolites, 35 secondary metabolites and 64 inorganic elements were identified. Several primary metabolites, including shikimic acid and tricarboxylic acid cycle intermediates, were abundant in those located in Heilongjiang, Jilin, and Liaoning. Besides, bioactive lignans are also highly abundant in those from northeastern China than those from northwestern China. Inorganic elements varied significantly among the different locations. Our results suggested that the metabolite profiling approach using GC–TOF‐MS, ultra‐performance LC quadrupole TOF MS, and inductively coupled plasma MS is a robust and reliable method that can be effectively used to explore subtle variations among plants from different geographical locations.
The effect of peri‐conception hyperglycaemia and the involvement of the hexosamine biosynthesis pathway in mediating oocyte and embryo developmental competence
Authors: Frank Laura A. , Sutton‐McDowall Melanie L. , Gilchrist Robert B. , Thompson Jeremy G.
Published: January 2014

The environment that the oocyte is exposed to during the peri‐conception period can have a significant impact on oocyte developmental competence (the ability of the oocyte to support fertilisation and subsequent embryo development) and the long‐term health of the resulting offspring. This is particularly true for maternal hyperglycaemia. While maternal hyperglycaemia during early pregnancy through term development has been extensively studied, the effects on the oocyte itself, and the underlying mechanisms, remain largely unknown. There is increasing evidence, however, for the role of the fuel‐sensing hexosamine biosynthesis pathway in mediating the effects of hyperglycaemia in many different cell types. In this review, we will focus on the reproductive consequences of maternal hyperglycaemia during the peri‐conceptual period and the role of the hexosamine pathway in mediating these processes. Mol. Reprod. Dev. 81: ???–???, 2014. © 2014 Wiley Periodicals, Inc.
Neuronal inclusions of α‐synuclein contribute to the pathogenesis of Krabbe disease
Authors: Smith Benjamin R , Santos Marta B , Marshall Michael S , Cantuti‐Castelvetri Ludovico , Lopez‐Rosas Aurora , Li Guannan , van Breemen Richard , Claycomb Kumiko I , Gallea Jose I , Celej Maria S , Crocker Stephen J , Givogri Maria I , Bongarzone Ernesto R
Published: January 2014

Demyelination is a major contributor to the general decay of neural functions in children with Krabbe disease. However, recent reports have indicated a significant involvement of neurons and axons in the neuropathology of the disease. In this study, we have investigated the nature of cellular inclusions in the Krabbe brain. Brain samples from the twitcher mouse model for Krabbe disease and from patients affected with the infantile and late‐onset forms of the disease were examined for the presence of neuronal inclusions. Our experiments demonstrated the presence of cytoplasmic aggregates of thioflavin‐S‐reactive material in both human and murine mutant brains. Most of these inclusions were associated with neurons. A few inclusions were detected to be associated with microglia and none were associated with astrocytes or oligodendrocytes. Thioflavin‐S‐reactive inclusions increased in abundance, paralleling the development of neurological symptoms, and distributed throughout the twitcher brain in areas of major involvement in cognition and motor functions. Electron microscopy confirmed the presence of aggregates of stereotypic β‐sheet folded proteinaceous material. Immunochemical analyses identified the presence of aggregated forms of α‐synuclein and ubiquitin, proteins involved in the formation of Lewy bodies in Parkinson's disease and other neurodegenerative conditions. In vitro assays demonstrated that psychosine, the neurotoxic sphingolipid accumulated in Krabbe disease, accelerated the fibrillization of α‐synuclein. This study demonstrates the occurrence of neuronal deposits of fibrillized proteins including α‐synuclein, identifying Krabbe disease as a new α‐synucleinopathy. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd
Effect of internal electric field on non‐radiative carrier recombination in the strain‐balanced InGaAs/GaAsP multiple quantum well solar cells
Authors: Fukuyama Atsuhiko , Aihara Taketo , Yokoyama Yuki , Kojima Michiya , Fujii Hiromasa , Suzuki Hidetoshi , Sugiyama Masakazu , Nakano Yoshiaki , Ikari Tetsuo
Published: January 2014

Effect of an internal built‐in electric field on the non‐radiative recombination process of strain‐balanced InGaAs/GaAsP multiple quantum wells (MQWs) inserted into a GaAs p–i–n solar cell structure was investigated using the piezoelectric photo–thermal technique. From the experimental data obtained from two types of p–i–n solar cell structures with partly charge‐neutral and uniform‐gradient potentials, the decrease in the built‐in electric field contributed to the decrease in the non‐radiative carrier recombination in the MQW. This phenomenon was especially pronounced in the higher photon energy of the incident light and in large quantum well stack number. With the increase in the photon energy, the penetration length shortened, and most carriers were generated in the charge‐neutral area in the i‐region. The present experimental results could be understood by the increase in the radiative recombination processes within the MQW because of the wave function overlap is essentially unity.
Synthesis of location‐dependent phosphorus‐doped ZnO nanostructures on the porous alumina membranes
Authors: Hu Dazhi , Fan Donghua , Zhu Yufu , Wang Wei , Pan Fengming , Wu Ping , Fan Jiyu
Published: January 2014

Phosphorus‐doped ZnO nanostructures are synthesized on porous alumina membranes by evaporating the mixture of pure Zn, carbon, and P2O5 powder. The influences of growth area on phosphorus‐doped ZnO nanostructures are studied in detail. The Raman spectra indicate that phosphorus enters into the ZnO crystal lattice to easily form a Zn–P bond and/or a PZn–O one by occupying an O site and a Zn one. The further analyses for Raman spectra and SEM results display that the change of nanorods morphology should mainly be attributed to the relaxation of lattice strain caused by P occupying Zn sites. Compared with the morphology of samples on Si substrate, it is found that alumina membranes are helpful to the growth of nanostructures due to the existence of localized negative charges. The growth mechanism of different nanostructures is also discussed. The present research results are helpful to realize the preparation of phosphorus‐doped ZnO nanostructures with controllable morphologies.
Long‐Term Results After Adult Ex Situ Split Liver Transplantation Since Its Introduction in 1987
Authors: Schrem Harald , Kleine Moritz , Lankisch Tim Oliver , Kaltenborn Alexander , Kousoulas Lampros , Zachau Lea , Lehner Frank , Klempnauer Jürgen
Published: January 2014

Background

Split liver transplantation is still discussed controversially. Utilization of split liver grafts has been declining since a change of allocation rules for the second graft abolished incentives for German centres to perform ex situ splits. We therefore analysed our long‐term experiences with the first ex situ split liver transplant series worldwide.

Methods

A total of 131 consecutive adult ex situ split liver transplants (01.12.1987–31.12.2010) were analysed retrospectively.

Results

Thirty‐day mortality rates and 1‐ and 3‐year patient survival rates were 13, 76.3, and 66.4 %, respectively. One‐ and three‐year graft survival rates were 63.4 and 54.2 %, respectively. The observed 10‐year survival rate was 40.6 %. Continuous improvement of survival from era 1 to 3 was observed (each era: 8 years), indicating a learning curve over 24 years of experience. Patient and graft survival were not influenced by different combinations of transplanted segments or types of biliary reconstruction (p > 0.05; Cox regression). Patients transplanted for primary sclerosing cholangitis had better survival (p = 0.021; log‐rank), whereas all other indications including acute liver failure (13.6 %), acute and chronic graft failure (9.1 %) had no significant influence on survival (p > 0.05; log‐rank). Biliary complications (27.4 %) had no significant influence on patient or graft survival (p > 0.05; log‐rank). Hepatic artery thrombosis (13.2 %) had a significant influence on graft survival but not on patient survival (p = 0.002, >0.05, respectively; log‐rank).

Conclusions

Split liver transplantation can be used safely and appears to be an underutilized resource that may benefit from liberal allocation of the second graft.