bluuebunny/crossref_metadata_2025 huggingface dataset:
Shape‐Controlled Nanostructures in Heterogeneous Catalysis
Authors: Zaera Francisco
Published: September 2013

Nanotechnologies have provided new methods for the preparation of nanomaterials with well‐defined sizes and shapes, and many of those procedures have been recently implemented for applications in heterogeneous catalysis. The control of nanoparticle shape in particular offers the promise of a better definition of catalytic activity and selectivity through the optimization of the structure of the catalytic active site. This extension of new nanoparticle synthetic procedures to catalysis is in its early stages, but has shown some promising leads already. Here, we survey the major issues associated with this nanotechnology–catalysis synergy. First, we discuss new possibilities associated with distinguishing between the effects originating from nanoparticle size versus those originating from nanoparticle shape. Next, we survey the information available to date on the use of well‐shaped metal and non‐metal nanoparticles as active phases to control the surface atom ensembles that define the catalytic site in different catalytic applications. We follow with a brief review of the use of well‐defined porous materials for the control of the shape of the space around that catalytic site. A specific example is provided to illustrate how new selective catalysts based on shape‐defined nanoparticles can be designed from first principles by using fundamental mechanistic information on the reaction of interest obtained from surface‐science experiments and quantum‐mechanics calculations. Finally, we conclude with some thoughts on the state of the field in terms of the advances already made, the future potentials, and the possible limitations to be overcome.
Comparing operational definitions of DSM‐5 anorexia nervosa for research contexts
Authors: Brown Tiffany A. , Holland Lauren A. , Keel Pamela K.
Published: September 2013

Objective

DSM‐5 anorexia nervosa (AN) criteria include several changes that increase reliance on clinical judgment. However, research contexts require operational definitions that can be applied reliably and that demonstrate validity. The present study evaluated different operational definitions for DSM‐5 AN.

Method

DSM‐5 AN criteria were applied to diagnostic interview data from 364 women varying two features: threshold for determining low weight for Criterion A (body mass index [BMI] <17.0 kg/m2 vs. <18.5 kg/m2) and explicit endorsement of weight phobia (Criterion B explicit vs. inferred). Resulting groups of individuals with DSM‐5 AN were compared on estimated frequency. In addition, AN groups were compared to non‐eating disorder controls and individuals with an other specified feeding or eating disorder (OSFED) on external validators.

Results

All operational DSM‐5 definitions produced higher lifetime frequency estimates than reported for DSM‐IV AN, with a particularly large increase associated with the broadest definition. All definitions produced significant differences in comparison to controls on external validators that were associated with medium to large effect sizes. Only definitions that required a lower weight threshold or explicit endorsement of weight phobia demonstrated significant differences compared to OSFED on external validators, and these were of small effect size. The specific combination of BMI <18.5 kg/m2 with inferred weight phobia exhibited few meaningful distinctions from the OSFED group.

Discussion

To balance inclusivity, syndromal reliability, and validity, an operational definition for DSM‐5 AN in research contexts should define low weight as BMI <18.5 kg/m2 and require measurable rather than inferred weight phobia. © 2013 Wiley Periodicals, Inc. (Int J Eat Disord 2014; 47:76–84)
Microglia in normal appearing white matter of multiple sclerosis are alerted but immunosuppressed
Authors: Melief Jeroen , Schuurman Karianne G. , van de Garde Martijn D. B. , Smolders Joost , van Eijk Marco , Hamann Jörg , Huitinga Inge
Published: September 2013

Little is known about the functional phenotype of microglia in normal appearing white matter (NAWM) of multiple sclerosis (MS), although it may hold valuable clues about mechanisms for lesion development. Therefore, we studied microglia from NAWM obtained post‐mortem from controls (n = 25) and MS patients (n = 21) for their phenotype ex vivo and their immune responsiveness in vitro, using a microglia isolation method that omits culture and adherence. By flow cytometry, microglia in MS NAWM displayed elevated CD45 levels and increased size and granularity but were distinct from autologous choroid plexus macrophages by absent or low expression of additional markers, in particular CD206. Flow cytometric analysis of microglia from NAWM of three controls and four MS patients showed alterations in levels of Fc‐gamma receptors in MS. In primary microglia from a bigger sample of subjects, analysis of Fc‐gamma receptors by quantitative PCR indicated a significant increase in mRNA levels of the inhibitory CD32b isoform in MS NAWM. Despite their changed activation status, microglia from MS NAWM were unresponsive to lipopolysaccharide in vitro. Notably, culture with dexamethasone led to an impaired induction of the inflammation‐limiting cytokine CCL18 in microglia from MS NAWM compared with those from control NAWM. Together, these data demonstrate that microglia in MS NAWM are in an alerted state, but display features of immunosuppression. Thus, the activation status of microglia in NAWM of MS patients likely reflects a response to ongoing neuroinflammation, which coincides with upregulation of immunoregulatory molecules to prevent full activation and damage to the vulnerable milieu. GLIA 2013;61:1848–1861
Cdc42 regulates schwann cell radial sorting and myelin sheath folding through NF2/merlin‐dependent and independent signaling
Authors: Guo Li , Moon Chandra , Zheng Yi , Ratner Nancy
Published: September 2013

The Rho family GTPase Cdc42 has been implicated in developmental Schwann cell (SC) proliferation, providing sufficient SCs for radial sorting of axons preceding SC differentiation in the peripheral nervous system. We generated Cdc42 conditional knockout (Cdc42‐CKO) mice and confirmed aberrant axon sorting in Cdc42‐CKO nerves. In adult Cdc42‐CKO nerves, blood vessels were enlarged, and mature Remak bundles containing small axons were absent. Abnormal infoldings and outfoldings of myelin sheaths developed in Cdc42‐CKO nerves, mimicking pathological features of Charcot‐Marie‐Tooth (CMT) disease. The NF2/merlin tumor suppressor has been implicated up‐ and down‐stream of Cdc42. In Cdc42‐CKO;NF2‐del double mutant mice, radial sorting defects seen in Cdc42‐CKO nerves were rescued, while changes in myelin sheaths in Cdc42‐CKO nerves were not. Phosphorylation of Focal adhesion kinase (FAK) and P‐GSK3β, as well as expression of β‐catenin were decreased in Cdc42‐CKO nerves, and these changes were rescued by NF2/merlin mutation in Cdc42‐CKO;NF2‐del double mutant mice. Thus, Cdc42 regulates SC radial sorting in vivo through NF2/merlin dependent signaling pathways, while Cdc42 modulation of myelin sheath folding is NF2/merlin independent. GLIA 2013;61:1906–1921
An evaluation of approaches for modelling hydrological processes in high‐elevation, glacierized Andean watersheds
Authors: Ragettli S. , Cortés G. , McPhee J. , Pellicciotti F.
Published: September 2013

We use two hydrological models of varying complexity to study the Juncal River Basin in the Central Andes of Chile with the aim to understand the degree of conceptualization and the spatial structure that are needed to model present and future streamflows. We use a conceptual semi‐distributed model based on elevation bands [Water Evaluation and Planning (WEAP)], frequently used for water management, and a physically oriented, fully distributed model [Topographic Kinematic Wave Approximation and Integration ETH Zurich (TOPKAPI‐ETH)] developed for research purposes mainly. We evaluate the ability of the two models to reproduce the key hydrological processes in the basin with emphasis on snow accumulation and melt, streamflow and the relationships between internal processes. Both models are capable of reproducing observed runoff and the evolution of Moderate‐resolution Imaging Spectroradiometer snow cover adequately. In spite of WEAP's simple and conceptual approach for modelling snowmelt and its lack of glacier representation and snow gravitational redistribution as well as a proper routing algorithm, this model can reproduce historical data with a similar goodness of fit as the more complex TOPKAPI‐ETH. We show that the performance of both models can be improved by using measured precipitation gradients of higher temporal resolution. In contrast to the good performance of the conceptual model for the present climate, however, we demonstrate that the simplifications in WEAP lead to error compensation, which results in different predictions in simulated melt and runoff for a potentially warmer future climate. TOPKAPI‐ETH, using a more physical representation of processes, depends less on calibration and thus is less subject to a compensation of errors through different model components. Our results show that data obtained locally in ad hoc short‐term field campaigns are needed to complement data extrapolated from long‐term records for simulating changes in the water cycle of high‐elevation catchments but that these data can only be efficiently used by a model applying a spatially distributed physical representation of hydrological processes. Copyright © 2013 John Wiley & Sons, Ltd.
Air and water flows induced by pumping tests in unconfined aquifers with low‐permeability zones
Authors: Kuang Xingxing , Jiao Jiu Jimmy , Zhang Keni , Mao Deqiang
Published: September 2013

Air flows from the atmosphere into an unconfined aquifer when the water table falls during pumping tests. Pumping test results in unconfined aquifers may be significantly affected by low‐permeability zones (LPZs) near the initial water table position, because they restrict the downward movement of air. A transient, three‐dimensional air–water two‐phase flow model is employed to investigate numerically the effects of local heterogeneity on pumping test results in unconfined aquifers. Two cases of local heterogeneities are considered herein: a LPZ around the pumping well and on one side of the pumping well. Results show that the drawdown with the LPZ is significantly greater than that of the homogeneous aquifer. The differences in drawdown are the most significant at intermediate times and gradually diminish at later times. The LPZ significantly reduces air flow from the atmosphere to the aquifer. The pore air velocity in the LPZ is very low. The air pressure at the observation point under the LPZ when air begins to enter is significantly lower than the air pressure of the homogeneous aquifer at the same point. After that, the air pressure increases quickly and then increases slowly. The time for the air pressure to reach the atmospheric pressure is significantly longer. Copyright © 2013 John Wiley & Sons, Ltd.
Solar cycle effects on parallel electric field acceleration of auroral electron beams
Authors: Cattell C. , Dombeck J. , Hanson L.
Published: September 2013

We present the occurrence frequency of downgoing auroral electron beams in magnetic local time and invariant latitude, and the dependence on solar cycle, as indicated by F10.7, on whether the ionospheric foot point of the satellite is illuminated or dark, and on the energy flux carried by the electrons. As previously reported, we find that the occurrence of electron beams peaks in the premidnight local time sector and that solar illumination at the foot point (solar zenith angle) reduces both the occurrence and energy of the electron beams. The effect of solar maximum conditions (indicated by F10.7) is almost as large as the effect of the solar zenith angle. The characteristic energy of the electron beams is dependent on the energy flux carried, in addition to both solar zenith angle and F10.7. The beam energy (and therefore the parallel potential drop) is ~1.6 times higher for during solar minimum than during solar maximum for both dark and illuminated foot points. The beam energy during dark solar minimum conditions is a factor of ~3 more than during sunlit minimum conditions. The “area” covered by intense aurora is also reduced during solar maximum, for both sunlit and dark conditions. There is no evidence that the statistical results are due to the fact that acceleration via parallel electric fields moves to lower latitudes during solar maximum.
Enhancing Digital Fluency through a Training Program for Creative Problem Solving Using Computer Programming
Authors: Kim SugHee , Chung KwangSik , Yu HeonChang
Published: September 2013

The purpose of this paper is to propose a training program for creative problem solving based on computer programming. The proposed program will encourage students to solve real‐life problems through a creative thinking spiral related to cognitive skills with computer programming. With the goal of enhancing digital fluency through this proposed training program, we investigated its effects. Two sets of experiments were performed in which 119 typical students and 30 younger, gifted students participated. Two synthetic creative problem solving tests, which had a high correlation with logical ability, scientific problem solving ability and divergent thinking ability, were developed to measure creative problem solving ability. We provided the treatment group with a paper‐based booklet with relevant problems developed specifically for that group. ANCOVA statistical procedures were used to analyze the pre‐ and post‐synthetic creative problem solving tests. The findings of our study are as follows: with typical students, the originality of the treatment group outperformed the control group, a result that was compatible with previous research. With gifted students, the fluency of the treatment group outperformed the control group, and overall creative problem solving ability was enhanced. Remarkably, fluency increased significantly, a notable difference from the results of prior studies. In conclusion, we inferred that, given the definition of digital fluency, if creative problem solving ability is enhanced by a training program for creative problem solving based on computer programming, digital fluency will ultimately be improved. In this paper, we discuss the result of fluency enhancement that contradicts prior research. We suggest that this training program could be a new learning environment for the students who have grown up with digital media.
Nanocomposite‐based stretchable optics
Authors: Ghisleri Cristian , Siano Mirko , Ravagnan Luca , Potenza Marco Alberto Carlo , Milani Paolo
Published: September 2013

Stretchable and conformable optical devices open up very exciting perspectives for the fabrication of systems incorporating diffracting and optical power in a single element. Supersonic cluster beam implantation of silver nanoparticles in an elastomeric substrate grooved by molding allows effective fabrication of cheap and simple stretchable optical elements able to withstand thousands of deformations and stretching cycles without any degradation of their optical properties. The nanocomposite‐based reflective optical devices were characterized both morphologically and optically showing excellent performances and stability compared to similar devices fabricated with standard techniques. The nanocomposite‐based devices can therefore be applied to arbitrary curved nonoptical grade surfaces in order to achieve optical power and to minimize aberrations like astigmatism. The high resilience of the nanocomposite material on which the devices are based allows them to be peeled and reused multiple times.
Investigations on the effect of chloride on the general corrosion behavior of low‐alloy steels in oxygenated high‐temperature water
Authors: Herbst M. , Roth A.
Published: September 2013

This project focused on investigations on the effect of chloride contaminations on the general corrosion and crack initiation behavior of low‐alloy steel (German reactor pressure vessel steel 22NiMoCr3 7) in oxygenated high‐temperature water (HTW). Therefore, tests were performed in oxygenated HTW without chloride and at different chloride contamination levels up to 50 ppb. Chloride was added either permanently or temporarily to simulate a chloride transient during plant operation. During these tests, electrochemical noise (EN) and electrochemical impedance spectroscopy (EIS) measurements were performed to monitor the electrochemical behavior depending on the adjusted environment conditions, especially the effect of chloride on the degradation of low‐alloy steel. After the tests, the specimens were examined macroscopically and microscopically. In addition, the oxide layer thickness was determined using the focused ion beam (FIB) technique and different surface analysis techniques as, e.g., TOF‐SIMS were performed to analyze the composition of the oxide layer. A change of the corrosion behavior of the tested specimens was revealed by the applied electrochemical methods EN and EIS during high‐temperature testing. In addition, the applied post‐test investigations showed a decrease in the oxide layer thickness due to permanently increased chloride concentrations in the HTW. Temporary transients, however, did not cause a long‐term memory effect as shown by both, the electrochemical and the metallographic post‐test investigations.
Determination of critical pitting temperatures for NiCrMo alloys using electrochemical noise measurements
Authors: Schmigalla S. , Heyn A.
Published: September 2013

The determination of critical pitting temperatures (CPT) in various test solutions like ferric chloride solution according to ASTM G48 or “Green Death” solution is a common test method for the comparative assessment of the pitting corrosion resistance of highly alloyed steels and NiCrMo alloys. In addition to the well‐known disadvantages of standard methods, like long test times, subjective examination, and large scatter, for the highest alloyed NiCrMo alloys no stable pitting corrosion can initiate even at the highest test temperatures. This paper describes the limitations of standard test methods and shows how these problems can be solved by an alternative test solution and an adjusted test method. By capturing and examining the current noise under potentiostatic conditions during continuous heating in a 4.5 M calcium chloride solution the transition from metastable to stable pitting corrosion as a criterion for CPT can be detected in a reproducible way.
High Optical Quality Films of Liquid Crystalline Cellulose Derivatives in Acrylates
Authors: Wenzlik Daniel , Zentel Rudolf
Published: September 2013

Cholesteric liquid crystals based on polymers are attractive because of their film‐forming properties. However, their optical properties (sharpness and directionality of the selective reflection) are usually lower than low molar mass compounds because of a polydomain structure and an angular distribution of the helix axes. In this work, cholesteric films made of liquid crystalline cellulose derivatives with improved optical properties are prepared. The careful choice of the solvent, hydrogen bond influencing additives, the synthetic realization of a very high degree of substitution on the cellulosic poly­mer, and the use of mechanical stirring in combination with a tuned substrate treatment and film‐preparation method and subsequent polymerization allow the fabrication of free standing cholesteric films of high optical quality. They show selective reflection with a half width of only 25 nm and nearly only perpendicular reflection. In addition, a method is developed by which fluorescent dyes can be introduced into the films after their preparation.

image
A Versatile Thiol‐ene/Sol–Gel Two‐Stage Curing Process Based on a Hyperbranched Polyester with Different Degrees of 10‐Undecenoyl Modification
Authors: Flores Marjorie , Foix David , Serra Angels , Ramis Xavier , Sangermano Marco
Published: September 2013

Hybrid thiol‐ene system based on a hyperbranched polyester with different degrees of 10‐undecenoyl modification are prepared via a dual UV‐thermal process. The pristine thiol‐ene formulation shows a high reactivity towards UV curing and the addition of the inorganic precursor to the photocurable formulation does not affect the UV‐curing process. The crosslinked systems show an increase of Tg by increasing the vinyl functionality content in the HBP and a Tg increase is also evidenced in the hybrid system as a function of inorganic precursor content. Morphological investigations show that the inorganic domains generated in situ are homogeneously distributed throughout the polymeric matrix. By varying the 10‐undecenoyl modification in the terminal groups of the HBP, the size of the inorganic domains is tunable and it is possible to decrease the dimension of the silica domains by using the HBP with a higher modification degree.
Click Construction of Spiro‐ and Bridged‐Quatrefoil Polymer Topologies with Kyklo‐Telechelics Having an Azide Group
Authors: Ko Yee Song , Yamamoto Takuya , Tezuka Yasuyuki
Published: September 2013

Unprecedented tetracyclic polymer topologies with spiro‐ and a bridged‐type quatrefoil forms are effectively constructed through an alkyne‐azide, click‐linking reaction by employing a kyklo‐telechelic poly(tetrahydrofuran), poly(THF), precursor having an azide group, obtained through an electrostatic self‐assembly and covalent fixation (ESA‐CF) process, and complementary tetrafunctional alkyne reagents of either a pentaerythritol derivative or a four‐armed star telechelic polymer precursor.

image
Changes of the donor nerve in end‐to‐side neurorrhaphies with epineurial window and partial neurectomy: A long‐term evaluation in the rat model
Authors: Liu Hai‐Fei , Chen Zeng‐Gan , Fang Tao‐Lin , Arnold Peter , Lineaweaver William C. , Zhang Jian
Published: September 2013

End‐to‐side (ETS) neurorrhaphy has been applied in the repair of peripheral nerve injuries and in babysitter procedures. However, the long‐term changes of donor nerve and muscle after ETS remain unknown. This study was designed to investigate long‐term changes in donor nerve and muscle in a rat model. Sixty Lewis rats were equally allocated into three groups of 20 rats. The peroneal nerve was divided. In Group A, end‐to‐end (ETE) neurorrhaphy was performed. In Group B, ETS was performed to an epineurial window on the tibial nerve. In Group C, ETS was performed to the tibial nerve with 40% partial neurectomy. The following data were obtained at 6, 12, 18, and 24 weeks postoperatively: latency delaying rate (LDR), amplitude recovery rate (ARR), myelinated fiber counts, muscle force and weight, and cross‐sectional area of gastrocnemius muscle fibers. The results showed no significant changes of the donor nerve and muscle in Group B. Nerve regeneration was found in the peroneal nerve, and myelinated fiber number was significantly decreased when compared to the nerve with ETE. In Group C, the myelinated axon number in the peroneal nerve was equivalent to the level in ETE repair. However, function and structure of the donor nerve and muscle were significantly impaired in the early postoperative period. Nonetheless, full recovery was observed 24 weeks after surgery. Both ETS with epineurial window and 40% donor nerve neurectomy showed reinnervation of the recipient nerve without structural and functional changes of the donor system in a long‐term follow‐up. Partial neurectomy may promote recipient nerve regeneration, but at the cost of donor neuromuscular compromises in the early postoperative period. This study provides long‐term evidence for further investigation of ETS in peripheral nerve repair and in babysitter procedures. © 2013 Wiley Periodicals, Inc. Microsurgery 34:136–144, 2014.
Strong stability and the Cayley transform
Authors: Halikias George
Published: September 2013

The general notion of ‘strong’ stability for internal autonomous system descriptions has been recently introduced for continuous and discrete‐time systems. This is a stronger notion of stability compared with alternative definitions (asymptotic, Lyapunov), which prohibits systems described by natural coordinates to have overshooting responses, for arbitrary initial conditions in state space. The paper reviews three refined notions of strong stability, along with the necessary and sufficient conditions corresponding to each notion. Using the Cayley transformation, it is shown that the notions in the two domains are essentially equivalent and that the strong stability conditions can be transformed from one domain to the other in a straightforward way. Copyright © 2013 John Wiley & Sons, Ltd.
Campanian‐Maastrichtian ocean circulation in the tropical Pacific
Authors: Jung Claudia , Voigt Silke , Friedrich Oliver , Koch Mirjam C. , Frank Martin
Published: September 2013

The Pacific Ocean is the largest water body on Earth, and circulation in the Pacific contributed significantly to climate evolution in the latest Cretaceous, the culmination of a period of long‐term cooling. Here, we present new high‐resolution late Campanian to Maastrichtian benthic and planktic foraminiferal stable isotope data and a neodymium (Nd) isotope record obtained from sedimentary ferromanganese oxide coatings of Ocean Drilling Program Hole 1210B from the tropical Pacific Ocean (Shatsky Rise). These new records resolve 13 million years in the latest Cretaceous, providing insights into changes in surface and bottom water temperatures and source regions of deep to intermediate waters covering the carbon isotope excursions of the Campanian‐Maastrichtian Boundary Event (CMBE) and the Mid‐Maastrichtian event (MME). Our new benthic foraminiferal δ18O and Nd isotope records together with published Nd isotope data show markedly parallel trends across the studied interval over a broad range of bathyal to abyssal water depths interpreted to reflect changes in the intensity of deep‐ocean circulation in the tropical Pacific. In particular, we observe a three‐million‐year‐long period of cooler conditions in the early Maastrichtian (72.5 to 69.5 Ma) when a concomitant change toward less radiogenic seawater Nd isotope signatures probably marks a period of enhanced admixture and northward flow of deep waters with Southern Ocean provenance. We suggest this change to have been triggered by intensified formation and convection of deep waters in the high southern latitudes, a process that weakened during the MME (69.5 to 68.5 Ma). The early Maastrichtian cold interval is closely related to the negative and positive carbon isotope trends of the CMBE and MME. The millions‐of‐years long duration of these carbon cycle perturbations suggests a tectonic forcing of climatic cooling, possibly related to changes in ocean basin geometry and bathymetry.
Composite of cellulosic agricultural waste coated with semiconducting polypyrrole as potential dye remover
Authors: Ovando‐Medina Víctor M. , Díaz‐Flores Paola E. , Martínez‐Gutiérrez Hugo , Moreno‐Ruiz Luis A. , Antonio‐Carmona Iveth D. , Hernández‐Ordoñez Martín
Published: September 2013

A composite was obtained from cellulosic agricultural waste material (Sorghum vulgare) coated with conducting polypyrrole by in situ polymerization using potassium persulfate as chemical oxidant. The composite was characterized by Raman spectroscopy, FTIR spectroscopy, scanning electron microscopy (SEM), and cyclic voltammetry. Aqueous adsorption experiments of methylene blue dye onto the obtained materials at different pH values were conducted. The results showed that this composite is an efficient sorbent for dye removal. The adsorption mechanism was well described by the Langmuir isotherm. The adsorption capacity at neutral pH for uncoated sorghum at an equilibrium concentration (Ce) of methylene blue dye of 10 mg/l was 41.6 mg of dye/g of sorghum and for sorghum/PPy composite was 68.4 mg of dye/gram of composite, which is 1.6 times higher; however, the maxima adsorption capacities were 86.2 and 94.4 mg/g, respectively (only 9.5% more than the uncoated sorghum). It was also observed that at acidic pH for a Ce of 10 mg/l the adsorption capacity of composite was 79.2 mg of dye/gram of composite and the maximum adsorption capacity was 143.5 mg/g (66.4% more than the uncoated sorghum). SEM analysis showed homogeneous coating of cellulosic sorghum material with PPy. Conductivity value of composite was 13.0 × 10−3 S/m. Fabrication of this composite should significantly diminish the cost of dye removal from aqueous solutions with respect to some commercial adsorbents. POLYM. COMPOS., 35:186–193, 2014. © 2013 Society of Plastics Engineers
In Vivo Alterations in Drug Metabolism and Transport Pathways in Patients with Chronic Kidney Diseases
Authors: Joy Melanie S. , Frye Reginald F. , Nolin Thomas D. , Roberts Brittney V. , La Mary K. , Wang Jinzhao , Brouwer Kim L.R. , Dooley Mary Anne , Falk Ronald J.
Published: September 2013

Study Objective

This study was designed to prospectively evaluate the in vivo activities of drug transporters, metabolizing enzymes, and pharmacokinetics in patients with chronic kidney diseases (CKD) caused by glomerulonephritis and nonglomerular etiologies.

Design

A prospective study design.

Participants

Eighteen adults with CKD.

Setting

General Clinical Research Center at the University of North Carolina and University of Pittsburgh.

Measurement and Main Results

Blood and urine were collected and assayed for fexofenadine (transporter function) as well as flurbiprofen and 4‐hydroxyflurbiprofen (CYP2C9 function). CYP3A4 activity was assessed by the erythromycin breath test. In patients with glomerulonephritis, the apparent oral clearance of fexofenadine (representing transporter activity) was 58.8 ± 34.4 L/hour, documenting a 40% reduction compared with previous data in healthy controls. The CYP2C9 pathway (4‐hydroxyflurbiprofen formation clearance) was similar in all the patients with CKD and was concordant with previous reports of patients with end‐stage renal disease (ESRD) and healthy controls. For flurbiprofen, patients with glomerulonephritis had higher oral clearance than those with nonglomerular CKD, suggesting higher unbound fraction and enhanced metabolism through other (non‐CYP2C9) routes. No statistically significant differences in CYP3A4 activity were observed in either group of patients or when compared with results from previous studies of patients with ESRD or healthy controls.

Conclusions

The current study suggests no statistically significant differences in the in vivo activity of CYP2C9 and CYP3A4 in patients with either glomerulonephritis or nonglomerular CKD. However, there are clinical differences in transporter function as defined by at least a 25% reduction in activity in glomerulonephritis as opposed to healthy controls. A similarity in the in vivo function between patients with glomerulonephritis and ESRD, and between patients with glomerulonephritis and nonglomerular CKD was present despite significant differences in kidney function. Further in vivo and in vitro studies are necessary to fully understand the physiologic and disease‐specific nuances that contribute to alterations in drug disposition in patients with kidney diseases.
Formation of Widmanstätten Ferrite in a 0.036% Nb Low Carbon Steel at Temperatures Above the Ae3
Authors: Basabe Vladimir V. , Jonas John J. , Ghosh Chiradeep
Published: September 2013

The formation of Widmanstätten ferrite was investigated in a 0.036% Nb microalloyed steel at temperatures above the Ae3 using optical microscopy, scanning electron microscopy, and electron backscatter diffraction. Such strain‐induced ferrite appears to form in two consecutives stages: (i) stage I, first observed at strains below 0.5, leads to the presence of Widmanstätten ferrite plates only about 200 nm wide, (ii) stage II, observed at strains >0.5, involves the coalescence of the Widmanstätten plates into grains. Thus the microstructures formed by dynamic transformation are composed of fresh Widmanstätten plates (stage 1) and polygonal grains (stage 2). Over the experimental temperature range of 836–896°C, the ultrafine ferrite plates and grains have areas below 2 µm2 and are difficult to detect using optical microscopy.
Effect of Intercritical Annealing Time on Microstructure and Axial Mechanical Properties of TRIP Seamless Steel Tube
Authors: Zhang Zicheng , Li Yanmei , Kong Xiangwei , Manabe Ken‐ichi , Wang Na
Published: September 2013

The transformation‐induced plasticity (TRIP) seamless steel tube, which is expected to be used in the hydroforming process, was prepared with piercing, cold‐drawing and two‐stage heat treatment process (intercritical annealing, “IA” and isothermal bainite treatment, “IBT”). The current study focused on the effect of IA holding time on microstructure and mechanical properties of TRIP seamless steel tube at a predetermined other heat treatment conditions, to maximize the volume fraction and stability of retained austenite as well as to obtain a TRIP seamless steel tube with good combination of strength and ductility. The microstructure and retained austenite volume fraction of the heat‐treated steel tubes were studied via optical microscopy, transmission electron microscopy and X‐ray diffraction. Two‐stage heat treatment carried out in an electrical resistance furnace and a salt‐bath furnace showed that for a predetermined IA temperature, IBT temperature and time, the content of retained austenite as well as total elongation increased first and then decreased with increasing IA time in the set time range in this study. When IA time was 10 min, the largest retained austenite volume fractions for both steel tubes was obtained. As a result, the TRIP seamless steel tube with an austenite volume fraction of 7.02%, total elongation of 35.5% and ultimate tensile strength of 618 MPa was successfully obtained.
Molecular Testing for Cystic Fibrosis Carrier Status Practice Guidelines: Recommendations of the National Society of Genetic Counselors
Authors: Langfelder‐Schwind Elinor , Karczeski Barbara , Strecker Michelle N. , Redman Joy , Sugarman Elaine A. , Zaleski Christina , Brown Trisha , Keiles Steven , Powers Amy , Ghate Sumheda , Darrah Rebecca
Published: September 2013

Purpose

To provide practice recommendations for genetic counselors whose clients are considering cystic fibrosis (CF) carrier testing or seeking information regarding CF molecular test results. The goals of these recommendations are to: 1) Provide updated information about the natural history, diagnosis, and treatment of CF and related conditions. 2) Supplement genetic counselors’ knowledge and understanding of the available carrier screening and diagnostic testing options. 3) Describe the current state of genotype/phenotype correlations forCFTRmutations and an approach to interpreting both novel and previously described variants. 4) Provide a framework for genetic counselors to assist clients’ decision‐making regarding CF carrier testing, prenatal diagnosis, and pregnancy management.

DisclaimerThe practice guidelines of the National Society of Genetic Counselors (NSGC) are developed by members of the NSGC to assist genetic counselors and other health care providers in making decisions about appropriate management of genetic concerns; including access to and/or delivery of services. Each practice guideline focuses on a clinical or practice‐based issue, and is the result of a review and analysis of current professional literature believed to be reliable. As such, information and recommendations within the NSGC practice guidelines reflect the current scientific and clinical knowledge at the time of publication, are only current as of their publication date, and are subject to change without notice as advances emerge.

In addition, variations in practice, which take into account the needs of the individual patient and the resources and limitations unique to the institution or type of practice, may warrant approaches, treatments and/or procedures that differ from the recommendations outlined in this guideline. Therefore, these recommendations should not be construed as dictating an exclusive course of management, nor does the use of such recommendations guarantee a particular outcome. Genetic counseling practice guidelines are never intended to displace a health care provider's best medical judgment based on the clinical circumstances of a particular patient or patient population.

Practice guidelines are published by NSGC for educational and informational purposes only, and NSGC does not “approve” or “endorse” any specific methods, practices, or sources of information.
Airport metal detector activation is rare after posterior spinal fusion in children with scoliosis
Authors: Fabricant Peter D. , Robles Alex , Blanco John S.
Published: September 2013

Purpose

Since the September 11, 2001 terrorist attacks on the World Trade Center in New York City, travel security has become an ever-increasing priority in the United States. Frequent parent and patient inquiry and recent literature reports have generated interest in the impact of heightened security measures on patients with orthopaedic implants, and have indicated increasing rates of metal detector triggering. There are no reports to date, however, evaluating children and adolescents who have undergone posterior spinal fusion for scoliosis, so responses to patient and parent inquiries are not data-driven. The purpose of this study is to determine the frequency of airport metal detector triggering by patients who have had posterior-only spinal fusion and to characterise any potential predictors of metal detector activation.

Methods

A cross-sectional study was performed by interviewing 90 patients who underwent posterior-only spinal fusion for a diagnosis of juvenile or adolescent idiopathic scoliosis and have travelled by air in the past year. Demographic, clinical and surgical instrumentation data were collected and evaluated, along with patients’ reports of airport metal detector triggering and subsequent screening procedures.

Results

Five patients with stainless steel instrumentation (5.6 % of the cohort) triggered an airport walkthrough metal detector, and an additional five patients who did not trigger an airport detector triggered a handheld detector at a different venue. All patients who triggered an airport metal detector had stainless steel instrumentation implanted prior to 2008, and no patient with titanium instrumentation triggered any detector in any venue. All trigger events required subsequent screening procedures, even when an implant card was presented.

Conclusions

In this cohort of children and adolescents with posterior spinal instrumentation, airport walkthrough metal detector triggering was a rare event. Therefore, we advise patients and families with planned posterior scoliosis fusions using titanium instrumentation that airport detection risk is essentially non-existent, and only rare for those with planned stainless steel instrumentation. We no longer issue implant cards postoperatively, as these did not prevent further screening procedures in this cohort.

Level of evidence

Prognostic level 2. Study design: cross-sectional.
The changing prevalence of infertility
Authors: Petraglia Felice , Serour Gamal I. , Chapron Charles
Published: September 2013

Infertility is a major, multifaceted issue worldwide whose prevalence is increasing in both high‐ and low‐income countries. The reasons are numerous, and may differ among world regions, but lifestyle and nutritional factors, epidemic infections, and sexually transmitted diseases are major determinants in most latitudes. Three other reasons may explain the increasing incidence of infertility. First, owing to the widespread use of contraception, the choice of delaying the first pregnancy until the third decade of life places men and women at higher risk for sexually transmitted diseases, and women at higher risk for uterine fibroids, endometriosis, polycystic ovary syndrome, and chronic anovulation. Second, prolonged exposure to chronic stress and environmental pollutants may play a critical role in decreasing fertility. Third, gonadotoxic oncologic treatments allow many patients to survive cancer, at the cost of their fertility. This consideration may justify the development of treatments that preserve fertility.
Numerical investigation of the flow dynamics past a three-element aerofoil
Authors: Deck Sébastien , Laraufie Romain
Published: September 2013

A numerical investigation of the flow dynamics around a two-dimensional high-lift configuration was carried out by means of a zonal detached eddy simulation (ZDES) technique for flow conditions corresponding to aircraft approach. Both slat and flap regions have been scrutinized and compared with experimental data available in the literature. It is shown that slat and flap coves behave like shallow cavities. The distance between the upstream cusp and the downstream edge is the relevant length scale for each cove taken separately. Consistently with previous findings, this study indicates that the maximum of the broadband spectrum of slat (respectively flap) pressure fluctuations occurs for Strouhal numbers$0. 5\leq \mathit{St}\leq 4$when based on slat chord (respectively on flap chord) and free-stream velocity. It is shown that mode$(n)$of the slat cove and mode$(n+ 1)$of the flap cove are very close making a coherent phase relationship possible. A large-scale coupled self-sustained oscillations mechanism between slat and flap cavities, evidenced by spectral analysis, occurs at a Strouhal number$\mathit{St}= 3{\unicode{x2013}} 6$based on the main wing chord and free-stream velocity. This yields to an acoustic feedback mechanism characterized by a normalized frequency depending on the free stream Mach number like$\mathit{St}= (1- { M}_{0}^{2} )/ 2{M}_{0} $. The present result appears to line up with the findings by Heinet al. (J. Fluid Mech., vol. 582, 2007, pp. 179–202) who showed that two types of resonance could exist: surface waves ones, scaling with the total aerofoil length and longitudinal cavity-type resonances, scaling with the slat cove length.
Inertial instability of intense stratified anticyclones. Part 1. Generalized stability criterion
Authors: Lazar Ayah , Stegner A. , Heifetz E.
Published: September 2013

The stability of axisymmetric vortices to inertial perturbations is investigated by means of linear stability analysis, taking into account stratification, vertical eddy viscosity, as well as finite depth of the flow. We consider different types of circular barotropic vortices in a linearly stratified shallow layer confined with rigid lids. For the simplest case of the Rankine vortex we develop an asymptotic analytic dispersion relation and a marginal stability criterion, which compares well with numerical results. This is a further generalization to the well-known generalized Rayleigh criterion, which is only valid for non-dissipative and non-stratified eddies. Unlike the Rayleigh criterion, it predicts that intense anticyclones may be stable even with a core region of negative absolute vorticity, and that the dissipation and stratification work together to stabilize the flow. Numerical analysis reveals that the stability diagrams for various types of vortices are almost identical in the Rossby, Burger and Ekman parameter space. This allows extension of our analytical solutions for the Rankine vortex to a wide variety of vortices. Furthermore, we show that a more suitable parameter for the intensity of the vortex is the vortex Rossby number, while for the inviscid case it is the local normalized vorticity. These predictions are in agreement with laboratory experiments presented in part 2 (J. Fluid Mech., vol. 732, 2013, pp. 485–509).
Inertial instability of intense stratified anticyclones. Part 2. Laboratory experiments
Authors: Lazar Ayah , Stegner A. , Caldeira R. , Dong C. , Didelle H. , Viboud S.
Published: September 2013

Large-scale laboratory experiments were performed on the Coriolis rotating platform to study the stability of intense vortices in a thin stratified layer. A linear salt stratification was set in the upper layer on top of a thick barotropic layer, and a cylinder was towed in the upper layer to produce shallow cyclones and anticyclones of similar size and intensity. We focus our investigations on submesoscale eddies, where the radius is smaller than the baroclinic deformation radius. Towing speed, cylinder size and stratification were changed in order to cover a large range of the parameter space, staying in a relatively high horizontal Reynolds number ($Re= 2000{{\unicode{x2013}}}7000$). The Rayleigh criterion states that inertial instabilities should strongly destabilize intense anticyclonic eddies if the vorticity in the vortex core is negative enough ${\zeta }_{0} / f\lt - 1$, where ${\zeta }_{0} $ is the relative vorticity in the core of the vortex, and $f$ is the Coriolis parameter. However, we found that some anticyclones remain stable even for very intense negative vorticity values, up to ${\zeta }_{0} / f= - 3. 5$, when the Burger number is large enough. This is in agreement with the linear stability analysis performed in part 1 (J. Fluid Mech., vol. 732, 2013, pp. 457–484), which shows that the combined effect of a strong stratification and a moderate vertical dissipation may stabilize even very intense anticyclones, and the unstable eddies we found were located close to the marginal stability limit. Hence, these experimental results agree well with the simple stability diagram proposed in the Rossby, Burger and Ekman parameter space for inertial destabilization of viscous anticyclones within a shallow and stratified layer.
STRICTLY POSITIVE SOLUTIONS FOR ONE-DIMENSIONAL NONLINEAR PROBLEMS INVOLVING THE -LAPLACIAN
Authors: KAUFMANN U. , MEDRI I.
Published: September 2013

Let $\Omega $ be a bounded open interval, and let $p\gt 1$ and $q\in (0, p- 1)$. Let $m\in {L}^{{p}^{\prime } } (\Omega )$ and $0\leq c\in {L}^{\infty } (\Omega )$. We study the existence of strictly positive solutions for elliptic problems of the form $- (\vert {u}^{\prime } \mathop{\vert }\nolimits ^{p- 2} {u}^{\prime } ){\text{} }^{\prime } + c(x){u}^{p- 1} = m(x){u}^{q} $ in $\Omega $, $u= 0$ on $\partial \Omega $. We mention that our results are new even in the case $c\equiv 0$.
Hunger Strikers: Historical Perspectives from the Emergency Management of Refugee Camp Asylum Seekers
Authors: Burkle Frederick M. , Chan Jimmy T. S. , Yeung Richard D. S.
Published: September 2013

The treatment of hunger strikers is always contentious, chaotic and complex. The management is particularly difficult for health professionals as it raises unprecedented clinical, ethical, moral, humanitarian, and legal questions. There are never any easy answers. The current situation of prisoners from the Iraq and Afghanistan Wars currently at the Guantanamo Bay Detention Center in Cuba demands unprecedented transparency, accountability and multilevel coordination to ensure that the rights of the strikers are properly met. There are scant references available in the scientific literature on the emergency management of these tragedies. This historical perspective documents the complex issues faced by emergency physicians in Hong Kong surrounding refugee camp asylum seekers from Vietnam in 1994 and is offered as a useful adjunct in understanding the complex issues faced by emergency health providers and managers.

BurkleFMJr., ChanJTS, YeungRSD. Hunger strikers: historical perspectives from the emergency management of refugee camp asylum seekers. Prehosp Disaster Med. 2013:28(6);1-5.