bluuebunny/crossref_metadata_2025 huggingface dataset:
A bioinspired hybrid optimization algorithm for designing broadband frequency selective surfaces
Authors: de Araújo Wellington C. , Lins Hertz W. C. , D'Assunção Adaildo G. , Medeiros Joêmia L. G. , D'Assunção Adaildo G.
Published: December 2013

A hybrid optimization technique is used to synthesize frequency selective surface (FSS) structures composed of periodic arrays of integrated rings and dipole patch elements, printed on dielectric substrates, for microwave filtering applications. The optimization technique is based on the combination of genetic algorithms and neural networks. This hybrid optimization technique is used to determine specific values for the resonant frequency and bandwidth from variations of the FSS structural parameters, such as patch element and periodic array dimensions. The synthesized FSS structure is also analyzed using a fast and accurate wave concept iterative procedure for comparison purpose. Thereafter, prototypes are built and measured. A good agreement is observed between simulated and measured results. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:329–333, 2014
Temperature insensitive fiber optical displacement sensors based on double fiber Bragg gratings
Authors: Jiang Ming , Cui Liuzhu , Liu Rong
Published: December 2013

A temperature insensitive fiber optical displacement sensor based on double Bragg gratings is presented and experimentally demonstrated. The sensor is constructed by a trapezoid slid block and two isosceles cantilevered beams, and two fiber Bragg gratings (FBG) that are glued on the two beams. The displacement can be measured by interrogating the wavelength difference of the two FBGs, and the temperature dependence is greatly reduced. Experimental results show that a displacement sensitivity of 120 pm/mm and a temperature dependence of 2.1 pm/°C are achieved. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:304–306, 2014
A compact broadband spiral antenna for millimeter wave applications
Authors: Chernobrovkin Roman , Ivanchenko D. , Ivanchenko I. , Popenko N. , Pishikov V.
Published: December 2013

The planar spiral antenna being connected with the waveguide and operating in the long‐wave region of the millimeter range is proposed. The antenna has the bandwidth of 6 GHz and the axial ration which does not exceed −3dB in the frequency band 32–36.5 GHz. The radiation pattern shape is slightly changed within the operational frequency band. The results of simulations and experimental data are in good agreement. The nature of radiation pattern and axial ration changing within the operational frequency band is explained from the analysis of near‐field distributions measured at two orthogonal polarizations. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:293–297, 2014
A tunable photonic RF phase shifter using single semiconductor optical amplifier
Authors: Chen Han , Sun Mingming , Ding Yi , Sun Xiaohan
Published: December 2013

A continuously tunable linear radio frequency phase shifter based on polarization interference in single semiconductor optical amplifier is presented, and the theoretical fundamentals of the design are explained. A prototype of the phase shifter with 10‐GHz bandwidth and far beyond 360° tuning range is experimentally demonstrated. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:340–343, 2014
A pneumatically controlled capacitive switch
Authors: Wu Billy , Okoniewski Michal , Hayden Chris
Published: December 2013

The design and fabrication process of a unique pneumatically controlled capacitive switch is described. The switch, developed for reconfigurable antennas, presents a low‐loss alternative switching mechanism, and avoids the issue of a complicated biasing layout associated with electrostatic actuation in the conducting layer. The closed state of the switch is created by a movable copper‐coated solid slug that bridges a gap in a microstrip line with capacitive coupling. The basis of the switching mechanism is pressurized air causing the physical displacement of the slug inside a confining dielectric channel. Repeatable switching between open and closed states by pneumatically controlling the position of the slug was demonstrated with the fabricated switch. The minimum pressure required to move the slug was measured. This switch was measured from 0.5 to 15 GHz using a Thru‐Reflect‐Line calibration to de‐embed the coax‐to‐microstrip transitions. Insertion loss of 0.2 dB and isolation of 25 dB have been achieved at 5 GHz. The successful fabrication and measurement of the switch demonstrates the viability of applying this technology in reconfigurable antenna designs. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:489–493, 2014
Plasmonic narrow band pass filter based on planner Lange coupler
Authors: Andrawis Robert
Published: December 2013

In this article, a new plasmonic narrow band pass filter is introduced and optimized versus different dimensions. The filter is based on Lange coupler with open circuit termination in two of its ports. The results are validated by two full‐wave solvers. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:446–448, 2014
A compact band‐notched ultrawideband dielectric‐loaded antenna
Authors: Tseng Ching‐Fang , Lu Shu‐Cheng
Published: December 2013

A compact ultrawideband (UWB) dielectric‐loaded antenna with band notched characteristics is presented. The antenna consists of the circular metal radiation patch fed by a 50‐Ω microstrip transmission line and a rectangular ground plane with cutting a notch to achieve UWB application. By etching a modified U‐shaped slot in the radiating patch and properly tuning its location and form, band rejected filtering properties in the WiMAX/WLAN bands can be achieved easily. The compact size of the proposed DRA can be reduced to 14.5 × 29 mm2 using a dielectric resonator (DR) above the modified circular radiation patch and possess band‐notched UWB characteristics. A good agreement has been obtained between simulation and measurement and it has good omnidirectional radiation patterns in H‐plane. Especially, the proposed band‐notched UWB loaded with GYA DR has excellent surrounding environment temperature stability. Base on these desirable features of the proposed band‐notched UWB dielectric‐loaded antenna, it is shown that it is a good candidate for various UWB applications. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:456–462, 2014
Microstrip multistopband filter based on prefractal space‐filling curve
Authors: Caramanica Federico
Published: December 2013

In this letter, a method for the design of miniaturized multistopband filters is presented. This methodology exploits multiple resonance behavior of a small‐size prefractal geometries. The considered fractal structures based on space‐filling curve geometry and then, after recasting the design problem as an optimization one by defining a suitable cost function, is optimized by an unsupervised procedure, the gravitational search algorithm, which is a recent and interesting stochastic optimization method. To assess the effectiveness of this approach, a filter with three stopbands has been designed, numerically assessed, and realized. The obtained results are in good agreement with the numerical simulations and this confirms the capabilities of the proposed method as a microwave Computer Aided Design (CAD) tool. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:450–455, 2014
Frequency selective surface with switchable polarization
Authors: Du Guohong , Yu Chengyang , Liu Changjun
Published: December 2013

This article presents a novel frequency selective surface (FSS) with switchable polarization, which is realized using the improved cross slots with embedded strips and isolated island structure. The transmission characteristics of FSS unit cell for both horizontal polarization and vertical polarization are simulated with CST. And a FSS made of an array of 20 × 20 cells is implemented on the substrate Rogers RO4003. The experiment results show that the proposed FSS can obtain polarization switching through short and open circuits for X‐band application. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:515–518, 2014
Design of an ultrawideband conformal metal antenna
Authors: Mondal S. , Sarkar P. P.
Published: December 2013

In this article, a novel design of volcano smoke antenna is proposed as an ultrawideband (UWB) conformal antenna. The radiating element and CPW feed line are in the same plane that makes the antenna completely planar. The proposed planar metal antenna is bent on a cylindrical surface, and the characteristics of the antenna for different bent conditions are studied. This study shows no significant change of reflection coefficient and radiation pattern characteristics of the bent antenna compared to that of flat position. The impedance bandwidth for S11 < −10 dB of the bent antenna covers the UWB (3.1–10.6 GHz). Variation of absolute gain and group delay of the antenna under flat and bent conditions are shown in this article. The measured reflection coefficient agrees with the simulated results. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:430–434, 2014
Quantitative cerebral blood flow with bolus tracking perfusion MRI: Measurements in porcine model and comparison with PET
Authors: Kellner Elias , Mix Michael , Reisert Marco , Förster Katharina , Nguyen‐Thanh Thao , Splitthoff Daniel Nico , Gall Peter , Kiselev Valerij G. , Mader Irina
Published: December 2013

Purpose

We recently presented a method for the quantitative measurement of the arterial input function which allows for determination of absolute cerebral blood flow (CBF) values without adjustable parameters. The aim of the present work is to estimate absolute CBF values by using this new technique and to compare it with the gold standard for cerebral perfusion,
positron emission tomography.

Methods

Pigs (13) were comparatively investigated by each method performing multiple measurement runs. The reproducibility of both methods was assessed by a voxel‐wise correlation of repeated measurements. An intersubject evaluation was performed on median whole‐brain CBF estimates.

Results

The mean CBF (MRI) was
for gray matter, the mean CBF (positron emission tomography) was
for gray and white matter. The reproducibility for MRI correlated with r = 0.85 and
, for positron emission tomography with r = 0.76 and
. The correlation for the median whole‐brain CBF in MRI and positron emission tomography was r = 0.60 and P = 0.04.

Conclusions

The proposed method allows for determination of quantitative CBF without normalization factors. The relatively low estimates of absolute CBF most likely results from the higher age of the pigs as compared to other studies. The intermediate correlation between both methods is caused by physiological intraindividual fluctuations of the CBF and by a limited reproducibility of both methods. Magn Reson Med 72:1723–1734, 2014. © 2013 Wiley Periodicals, Inc.
Can the adrenergic system be implicated in the pathophysiology of bladder pain syndrome/interstitial cystitis? A clinical and experimental study
Authors: Charrua Ana , Pinto Rui , Taylor Anna , Canelas André , Ribeiro‐da‐Silva Alfredo , Cruz Célia D. , Birder Lori Ann , Cruz Francisco
Published: December 2013

Aims

To evaluate sympathetic system activity in bladder pain syndrome/interstitial cystitis (BPS/IC) patients and to investigate if chronic adrenergic stimulation in intact rats induces BPS/IC‐like bladder modifications.

Methods

Clinical study—In BPS/IC patients and aged and body mass index matched volunteers TILT test was undertaken and catecholamines were measured in plasma and 24 hr urine samples. Experimental study—Phenylephrine was injected subcutaneously (14 days) to female Wistar rats. Pain behavior, spinal Fos expression, urinary spotting, number of fecal pellets expelled, frequency of reflex bladder contractions, and urothelial height were analyzed. Urothelium permeability was investigated by trypan blue staining. Immunoreactivity against caspase 3 and bax were studied in the urothelium and against alpha‐1‐adrenoreceptor and TRPV1 in suburothelial nerves. Mast cell number was determined in the sub‐urothelium. In rats with lipopolysaccharide‐induced cystitis, urinary catecholamines, and Vesicular Monoamine Transporter 2 (VMAT2) expression in bladder nerves were analyzed.

Results

The TILT test showed an increase of sympathetic activity. Noradrenaline levels in blood at resting conditions and in 24‐hr urine samples were higher in BPS/IC patients. Phenylephrine administration increased visceral pain, spinal Fos expression, bladder reflex activity, urinary spotting and the number of expelled fecal pellets. The mucosa showed urothelial thinning and increased immunoreactivity for caspase 3 and bax. Trypan blue staining was only observed in phenylephrine treated animals. Suburothelial nerves co‐expressed alpha1 and TRPV1. Mastocytosis was present in the suburothelium. Cystitis increased sympathetic nerve density and urinary noradrenaline levels.

Conclusions

Excessive adrenergic stimulation of the bladder may contribute to the pathophysiological mechanisms of BPS/IC. Neurourol. Urodynam. 34:489–496, 2015. © 2013 Wiley Periodicals, Inc.
Apparent diffusion coefficient measurements of the fetal brain during the third trimester of pregnancy: how reliable are they in clinical practice?
Authors: Sartor Agnès , Arthurs Owen , Alberti Corinne , Belarbi Nadia , Tilea Bogdana , Boizeau Priscilla , Oury Jean‐Francois , Elmaleh‐Berges Monique , Gressens Pierre , Sebag Guy , Alison Marianne
Published: December 2013

Objective

The objective of this study was to determine the reproducibility, the inter‐hemispheric difference and the reference apparent diffusion coefficient (ADC) values of the fetal brain according to gestational age.

Method

One hundred and one normal fetal brain (29.4–38.4 weeks) were analysed with diffusion‐weighted MR imaging. ADC was measured in frontal white matter (FWM), occipital white matter (OWM), centrum semi‐ovale (CSO), basal ganglia (BG), cerebellar hemisphere (CBM) and pons. ADC ratios (fronto‐occipital, fronto‐cerebellar and occipito‐cerebellar) were calculated. Inter‐observer reproducibility was assessed on 27 studies, using intra‐class correlation coefficient and Bland–Altman plot. Inter‐hemispheric difference was evaluated with Bland–Altman plot. Gestation‐specific reference intervals were estimated for each brain region.

Results

Inter‐observer bias was near zero. Limits of agreement (LOA) were clinically acceptable (−0.17; 0.20 to −0.38; 0.31 × 10−3 mm2/s) for all brain regions except for CSO and pons. Inter‐hemispheric bias was near zero. Smallest LOA were for FWM (±0.09 mm2/s) and BG (±0.019 mm2/s). ADC values decreased, whereas ADC ratio increased with gestational age, reflecting normal maturation. Fronto‐occipital, fronto‐cerebellar and occipito‐cerebellar ratios were consistently above 0.8, 1 and 1, respectively.

Conclusion

The fetal brain regions with the highest reproducibility and smallest inter‐hemispheric differences are the frontal, occipital, cerebellar white matter and BG. ADC ratio could be useful to assess differential temporo‐spatial maturation. © 2013 John Wiley & Sons, Ltd.
Effect of alkane chain segment length on the crystallization kinetics of nylon 1010, 1013 and 1014
Authors: Zhang Long , Zhang Xingyuan , Wu Lijun , Deng Yipeng , Liu Ruijie
Published: December 2013

Isothermal and non‐isothermal crystallization kinetics of long alkane chain segment nylon 1010, 1013 and 1014 were investigated by differential scanning calorimetry. The commonly used Avrami equation and that modified by Jeziorny were employed to fit the isothermal and non‐isothermal crystallizations of nylon 1010, 1013 and 1014, respectively. It was found that the crystallization rate of nylon with a longer alkane chain segment was slower than that of nylon with a shorter one at a given cooling rate. The activation energies for the isothermal and non‐isothermal crystallizations determined by the Arrhenius and the Kissinger methods, respectively, decreased with increase of the alkane chain segment length of nylon 1010, 1013 and 1014. Furthermore, the activation energy of the non‐isothermal crystallization process of these nylons, determined by the isoconversional methods of Flynn and Wall and Ozawa, was found to be a decreasing function of the relative degree of crystallinity. © 2014 Society of Chemical Industry
Synthesis and properties of new polyamide/multiwalled carbon nanotube nanocomposites containing a pyridine group
Authors: Shabanian Meisam , Basaki Nemat , Khonakdar Hossein Ali , Kianipour Shokat , Wagenknecht Udo
Published: December 2013

The effects of multiwalled carbon nanotubes (MWCNTs) on the thermal properties and flame retardancy of a new polyamide (PA) derived from glutaric acid and aromatic diamine were investigated in this work. The synthesized PA containing pyridine and trialkylamine groups was characterized by 1H NMR and SEC. The PA unit structure was geometrically optimized at the B3LYP/6‐311++G(d, p) level of theory. PA showed a glass transition temperature of 151 ºC. PA nanocomposites containing two different amounts of MWCNTs were prepared via the solution intercalation technique with the solvent N,N‐dimethylacetamide. Transmission electron microscopy showed that MWCNTs were exfoliated in the polymer matrix, resulting in well‐dispersed morphologies at 3 wt% MWCNT content. The redox behaviors of PA and the nanocomposites were examined using cyclic voltammetry (CV). PA showed a reversible oxidation process in the CV scan. Thermal and flammability properties of the nanocomposites were studied by TGA in nitrogen and air, DSC and with a microscale combustion calorimeter. The TGA results showed that the addition of MWCNTs resulted in a substantial increase in the thermal stability and char yields of the nanocomposites compared with neat PA. The heat release rate and total heat release were significantly reduced in the presence of MWCNTs. © 2013 Society of Chemical Industry
Improvement of the fire behavior of poly(1,4‐butanediol succinate)/flax biocomposites by fiber surface modification with phosphorus compounds: molecular versus macromolecular strategy
Authors: Dorez Gaëlle , Otazaghine Belkacem , Taguet Aurélie , Ferry Laurent , Lopez‐Cuesta José‐Marie
Published: December 2013

The grafting of phosphorus compounds onto natural fibers has been investigated as a strategy for improving poly(1,4‐butanediol succinate)/flax biocomposite fire behavior. Three phosphorus compounds − dihydrogen ammonium phosphate, poly(methacryloyloxy)methyl phosphonic acid homopolymer and poly(methacryloyloxy)methyl phosphonic acid methylmethacrylate copolymer − were selected. The aim of this work was to compare the fire performance conferred by the grafted compounds depending on whether phosphorus is brought by a molecule or a macromolecule. TGA, pyrolysis combustion flow calorimetry and cone calorimetry were used to characterize the thermal stability and fire behavior of the samples. The pyrolysis combustion flow calorimetry results showed that in all cases the presence of phosphorus changes the degradation pathway and thus the flammability properties of flax. The ability of the grafted flame retardant to promote char formation and residue formation was found to be dependent on the nature and quantity of phosphorus covalently bonded to flax. Conversely, cone calorimeter tests revealed similar fire behavior whatever the grafting agent. A significant increase of the char amount and a global enhancement of fire parameters were observed with increasing grafting rate. Moreover, phosphonated polymers promoted a charred sheath around the fibers which acts in addition to their charring, conferring a fire performance close to that of dihydrogen ammonium phosphate for the biocomposite.
MALDI imaging and in‐source decay for top‐down characterization of glioblastoma
Authors: Ait‐Belkacem Rima , Berenguer Caroline , Villard Claude , Ouafik L'Houcine , Figarella‐Branger Dominique , Chinot Olivier , Lafitte Daniel
Published: December 2013

Glioblastoma multiforme is one of the most common intracranial tumors encountered in adults. This tumor of very poor prognosis is associated with a median survival rate of approximately 14 months. One of the major issues to better understand the biology of these tumors and to optimize the therapy is to obtain the molecular structure of glioblastoma. MALDI molecular imaging enables location of molecules in tissues without labeling. However, molecular identification in situ is not an easy task. In this paper, we used MALDI imaging coupled to in‐source decay to characterize markers of this pathology. We provided MALDI molecular images up to 30 μm spatial resolution of mouse brain tissue sections. MALDI images showed the heterogeneity of the glioblastoma. In the various zones and at various development stages of the tumor, using our top‐down strategy, we identified several proteins. These proteins play key roles in tumorigenesis. Particular attention was given to the necrotic area with characterization of hemorrhage, one of the most important poor prognosis factors in glioblastoma.
The versatility of the αβ T‐cell antigen receptor
Authors: Bhati Mugdha , Cole David K. , McCluskey James , Sewell Andrew K. , Rossjohn Jamie
Published: December 2013

The T‐cell antigen receptor is a heterodimeric αβ protein (TCR) expressed on the surface of T‐lymphocytes, with each chain of the TCR comprising three complementarity‐determining regions (CDRs) that collectively form the antigen‐binding site. Unlike antibodies, which are closely related proteins that recognize intact protein antigens, TCRs classically bind, via their CDR loops, to peptides (p) that are presented by molecules of the major histocompatibility complex (MHC). This TCR‐pMHC interaction is crucially important in cell‐mediated immunity, with the specificity in the cellular immune response being attributable to MHC polymorphism, an extensive TCR repertoire and a variable peptide cargo. The ensuing structural and biophysical studies within the TCR‐pMHC axis have been highly informative in understanding the fundamental events that underpin protective immunity and dysfunctional T‐cell responses that occur during autoimmunity. In addition, TCRs can recognize the CD1 family, a family of MHC‐related molecules that instead of presenting peptides are ideally suited to bind lipid‐based antigens. Structural studies within the CD1‐lipid antigen system are beginning to inform us how lipid antigens are specifically presented by CD1, and how such CD1‐lipid antigen complexes are recognized by the TCR. Moreover, it has recently been shown that certain TCRs can bind to vitamin B based metabolites that are bound to an MHC‐like molecule termed MR1. Thus, TCRs can recognize peptides, lipids, and small molecule metabolites, and here we review the basic principles underpinning this versatile and fascinating receptor recognition system that is vital to a host's survival.
Comparative susceptibility of Bemisia tabaci to imidacloprid in field‐ and laboratory‐based bioassays
Authors: Castle Steven J , Merten Paul , Prabhaker Nilima
Published: December 2013

BACKGROUND

Bemisia tabaci biotype B is a resistance‐prone pest of protected and open agriculture. Systemic uptake bioassays used in resistance monitoring programs have provided important information on susceptibility to neonicotinoid insecticides, but have remained decoupled from field performance. Simultaneous bioassays conducted in field and laboratory settings were compared and related to concentrations of imidacloprid in plant tissue for clearer interpretation of resistance monitoring data.

RESULTS

Mean mortalities of adult whiteflies confined on cantaloupe leaves field‐treated with three rates of imidacloprid did not exceed 40% in two trials. In contrast, laboratory bioassays conducted on different subsets of the same whitefly populations yielded concentration–response curves suggestive of susceptibility to imidacloprid in five populations (LC50 values from 1.02 to 6.4) relative to a sixth population (LC50 = 13.8). In the field, densities of eggs and nymphs were significantly lower on the imidacloprid‐treated cantaloupes compared with the untreated control, but the margin of control was greater in 2006 than in 2007. The potential impact of imidacloprid on whitefly eggs was explored in a greenhouse test that showed egg mortality occurring in both early (one‐day‐old) and late (three‐day‐old) eggs on cotton leaves systemically treated with imidacloprid. Quantification of imidacloprid residues in cotton leaves used routinely in systemic uptake bioassays revealed concentrations that greatly exceeded concentrations found in the field‐treated cantaloupe leaves, at least at the three highest solution concentrations used for uptake.

CONCLUSION

Systemic uptake bioassays have been widely used for monitoring B. tabaci resistance to imidacloprid, but without knowledge of imidacloprid concentrations that occur in test leaves relative to field concentrations. Higher mortality observed in systemic uptake bioassays relative to field‐treated cantaloupes in this study suggests that field rates of imidacloprid are only partially effective against B. tabaci adults, in contrast to systemic uptake bioassays that showed susceptibility to imidacloprid. The discrepancy between field‐ and laboratory‐based mortalities is probably due to extraordinarily high concentrations of imidacloprid that can occur in leaves of systemic uptake bioassays, potentially skewing perception of susceptibility to imidacloprid. Published 2013. This article is a U.S. Government work and is in the public domain in the USA
Factors Affecting Success Rate of Advanced Trauma Life Support (ATLS) Courses
Authors: Abu‐Zidan Fikri M. , Mohammad Alshafi , Jamal Abdulla , Chetty Diane , Gautam Subash C. , van Dyke Murray , Branicki Frank J.
Published: December 2013

Background

The aim of the present study was to define the factors that affect passing the assessments for successful completion of the Advanced Trauma Life Support (ATLS) Provider Courses in the United Arab Emirates (UAE).

Methods

The ATLS Provider Course has been taught in three medical centers in the UAE since 2004. A total of 1,041 doctors completed the course during the period 2004–2010. A special protocol was designed to enter data accrued for each course, participants’ demographics, and assessments, including the final results. Direct logistic regression was performed to define factors affecting success in multiple choice questions (MCQ) and in the practical initial assessment station exam. The studied variables included the year, the course site, speciality, level of practice, and pre‐test score.

Results

The majority of participants were surgeons (33.2 %), followed by Emergency Medicine physicians (27.3 %). The logistic regression model showed that having a low pre‐test score (p < 0.0001) and being a family medicine practitioner (p < 0.0001) increased the likelihood of failing the MCQ exam. The chance of passing the end of course practical exam increased with time (p = 0.002). A low pre‐test score (p < 0.0001) and being examined in site A (p = 0.04) increased the chance of failing in the initial assessment exam. The pass rate for the ATLS exam significantly increased after adoption of the interactive approach to teaching.

Conclusions

Prior knowledge and preparation is essential to passing the ATLS exam. Doctors who deal clinically with all aspects of airway, breathing, and circulation of the ATLS course are more likely to pass the MCQ exam in our setting, followed by those who usually manage only the circulation or disability aspects of ATLS. It is possible that the interactive approach to teaching ATLS has improved the overall ATLS success rate.
Fructose promotes the differentiation of 3T3‐L1 adipocytes and accelerates lipid metabolism
Authors: Legeza Balázs , Balázs Zoltán , Odermatt Alex
Published: December 2013

Excessive fructose consumption and elevated glucocorticoids contribute to metabolic syndrome. We show that fructose as the only carbohydrate source is sufficient for the differentiation of 3T3‐L1 fibroblasts into adipocytes. Differentiation of cells in fructose containing medium resulted in increased 11β‐hydroxysteroid dehydrogenase 1 (11β‐HSD1) expression and activity. Experiments with transfected HEK‐293 cells suggested more efficient NADPH generation by fructose compared with glucose in the endoplasmic reticulum (ER). Adipocytes differentiated in the presence of fructose showed increased FABP4 expression, C/EBPα to C/EBPβ ratio and lipolysis. Thus, excessive fructose may cause adverse metabolic effects by enhancing 11β‐HSD1 activity and increasing lipolysis in adipocytes.
Komorbide Substanzstörungen in der erwachsenen Allgemeinbevölkerung
Authors: Piontek Daniela , Kraus Ludwig , Matos Elena Gomes de , Pabst Alexander
Published: December 2013

Ziel: Ziel ist die Untersuchung der homotypischen Komorbidität von Störungen im Zusammenhang mit dem Konsum von legalen und illegalen Substanzen sowie Medikamenten in der erwachsenen Bevölkerung. Methodik: Die Auswertungen basieren auf Daten des Epidemiologischen Suchtsurveys 2012. In einem zweistufigen Zufallsverfahren wurde eine Stichprobe von n = 9084 Personen realisiert (Ausschöpfung 53.6 %). Substanzbezogene Störungen nach DSM-IV wurden mithilfe des Münchener Composite International Diagnostic Interview für Alkohol, Tabak, Cannabis, Kokain, Amphetamine sowie Schmerz-, Schlaf- und Beruhigungsmittel erfasst. Ergebnisse: Multiple Diagnosen (Missbrauch und/oder Abhängigkeit) lagen bei insgesamt 6.6 % der Stichprobe vor. Der Anteil komorbider Substanzstörungen war bei Störungen durch Cannabis-, Schlafmittel- und Kokainkonsum am höchsten. Als Risikofaktoren für das Auftreten mindestens einer bzw. mehr als einer Diagnose erwiesen sich männliches Geschlecht, jüngeres Alter, niedrigere Schulbildung, lediger/geschiedener Familienstand und nicht-deutsche Staatsbürgerschaft. Schlussfolgerungen: Ein nicht unerheblicher Anteil der deutschen Bevölkerung ist von multiplen Substanzstörungen betroffen. Weitere epidemiologische Studien zur Beschreibung dieser Hochrisikogruppe sind nötig.
Hämatologische Veränderungen bei Anorexia nervosa im Kindes- und Jugendalter
Authors: Bühren Katharina , Gärtner Laura , Kennes Lieven N. , Seitz Jochen , Hagenah Ulrich , Herpertz-Dahlmann Beate
Published: December 2013

Fragestellung: Hämatologische Veränderungen sind ein häufiges Phänomen der akuten Anorexia nervosa (AN). Dennoch ist der Zusammenhang mit klinischen Parametern noch unzureichend untersucht. Methodik: Bei 88 Patientinnen mit AN nach DSM-IV wurden bei stationärer Aufnahme und nach Gewichtsrehabilitation die Konzentration der Leukozyten, Erythrozyten und Thrombozyten, der Hämoglobingehalt, der Hämatokrit und ein Differenzialblutbild bestimmt und ein Zusammenhang mit verschiedenen klinischen Parametern untersucht. Ergebnisse: Bei Aufnahme zeigten sich milde Veränderungen der Blutwerte, die zumeist mit der Gewichtsrehabilitation reversibel waren. Patientinnen mit einem großen Gewichtsverlust vor Aufnahme und einem niedrigen altersadjustierten BMI sowie diejenigen, die Psychopharmaka einnahmen, hatten ein größeres Risiko, hämatologische Veränderungen aufzuweisen. Schlussfolgerungen: Auch wenn die hämatologischen Veränderungen bei jugendlichen Patientinnen mit AN zumeist milde sind, sollte bei Patientinnen mit niedrigem altersadjustiertem BMI und/oder ausgeprägter Gewichtsabnahme oder begleitenden Psychopharmakotherapie, auf ein sorgfältiges Monitoring des Blutbildes geachtet werden. Eine Veränderung der leukozytenabhängigen Immunantwort scheint bei erwachsenen chronifizierten Patientinnen zu einer gesteigerten Infektionsgefahr und damit einer erhöhten Mortalität beizutragen.
Anorexia nervosa
Authors: Kappel Viola , van Noort Betteke , Ritschel Franziska , Seidel Maria , Ehrlich Stefan
Published: December 2013

Anorexia nervosa ist eine psychosomatische Erkrankung mit hoher Morbidität und Mortalität, die meist bei Mädchen und jungen Frauen auftritt. Bisher gibt es keine Hinweise auf die Überlegenheit eines bestimmten Therapieverfahrens ( Herpertz et al., 2011 ). Während der klinische Phänotyp bislang im Fokus stand, werden immer häufiger Methoden und Ansätze verwendet, die in der Anorexieforschung bisher unterrepräsentiert waren. Diese beinhalten zum einen die Untersuchung endokrinologischer Merkmale wie z. B. Hormone und andere Mediatoren, die wichtige Vorgänge der Gewichts- und Appetitregulation beeinflussen, aber auch die Erforschung von kognitiven Veränderungen und Persönlichkeitsmerkmalen, die oft auch nach Ende der akuten Krankheitsphase noch messbar sind. Dabei ist es vor allem wichtig, prädisponierende und die Krankheit aufrechterhaltende Faktoren zu identifizieren und zu unterscheiden. Nicht zuletzt ermöglichen bildgebende Verfahren seit einigen Jahren die genauere Untersuchung von funktionellen Zusammenhängen verschiedener Gehirnareale, die diesen prädisponierenden und aufrechterhaltenden Faktoren zugrunde liegen könnten. Letztendlich ist es das Ziel, mit Hilfe dieser neurowissenschaftlichen Methoden langfristig neuropsychologische und biologische Merkmale zu ermitteln, die ein besseres Verständnis der zugrundeliegenden Mechanismen von Anorexia nervosa ermöglichen und damit zur Verbesserung der Behandlung beitragen.
Pilotstudie zur Effektivität eines Emotionsregulationstrainings bei Frauen mit Binge-Eating-Störung
Authors: Svaldi Jennifer , Trentowska Monika , Bender Caroline , Naumann Eva , Tuschen-Caffier Brunna
Published: December 2013

Negative Emotionen sind ein häufiger Auslöser von Essanfällen bei Personen mit Binge-Eating-Störung (BES). Erste Untersuchungen haben gezeigt, dass Defizite in der Emotionsregulation (ER) den Zusammenhang von negativen Emotionen und Essanfällen mediieren. Vor diesem Hintergrund erhielten im Rahmen einer Pilotstudie 14 Frauen mit BES ein ER-Training in der Gruppe. Indikatoren für die Effektivität des Trainings waren Anzahl der Episoden und Tage mit objektiven Essanfällen, Körperunzufriedenheit, sowie Depressivität vor Studienbeginn (T0), nach 8 Wochen Wartezeit (T1) und nach dem 8-wöchigen ER-Training (T2). Während es keine Veränderungen von T0 zu T1 gab, zeigte sich eine signifikante Reduktion der Symptomatik in allen erhobenen Variablen von T1 zu T2. Die Ergebnisse der Pilotstudie unterstützen die Relevanz der ER bezüglich der Reduktion von Essanfällen und damit die Notwendigkeit gut implementierter Therapiestudien, die die Effektivität von ER-Trainings in der Veränderung der Psychopathologie der BES untersuchen. Zudem sind weitere Studien, die die Rolle der ER bei der Aufrechterhaltung der BES klären, notwendig.
Der Beziehungsmuster-Q-Sort (OPD-BQS): Ein Selbsteinschätzungsinstrument zur Erfassung von dysfunktionalen Beziehungsmustern auf Grundlage der Operationalisierten Psychodynamischen Diagnostik
Authors: Zimmermann Johannes , Stasch Michael , Grande Tilman , Schauenburg Henning , Cierpka Manfred
Published: December 2013

Die OPD-Beziehungsachse ( Arbeitskreis OPD, 2006 ) ist ein klinisch orientiertes Fremdbeurteilungsinstrument zur Erfassung von dysfunktionalen Beziehungsmustern. In diesem Artikel wird mit der Selbsteinschätzungsversion des Beziehungsmuster-Q-Sorts (OPD-BQS) ein neuer Zugang zur OPD-Beziehungsdiagnostik vorgestellt. Der BQS ist ein Kartensortierverfahren, mit dem eine Testperson einschätzen kann, welche dysfunktionalen interpersonalen Verhaltensweisen sie bei sich und anderen als typisch erlebt. Anhand von drei Stichproben mit insgesamt 170 Personen konnte gezeigt werden, (1) dass sich die Items des BQS hinsichtlich der bipolaren Dimensionen Nähe und Macht differenzieren lassen, (2) dass die Skalen zum Ausmaß der Probleme sowie zum Erleben von Nähe und Macht akzeptable interne Konsistenzen und Retest-Reliabilitäten aufweisen, (3) dass die konvergente und diskriminante Validität der Skalen gut bis sehr gut ist, und (4) dass die Skalen das zukünftige interpersonale Stresserleben vorhersagen. Mit dem BQS liegt erstmals ein gut validiertes Selbsteinschätzungsinstrument vor, das alternativ oder ergänzend zur OPD-Beziehungsdiagnostik eingesetzt werden kann und neue Forschungsmöglichkeiten eröffnet.
Enhanced stereoselectivity in a di-Ru(ii) complex of an achiral bis-bidentate ligand
Authors: Pal Amlan K. , Ducharme Philippe D. , Hanan Garry S.
Published: December 2013

The diastereoselective formation of a meso-dinuclear Ru(ii) complex of a novel bis-bidentate ligand is reported along with its electrochemical and photophysical properties.
A metal surface with chiral memory
Authors: Karageorgaki Chrysanthi , Ernst Karl-Heinz
Published: December 2013

Prochiral molecules locally induce a chiral restructuring of the Cu(110) surface that persists after removal of the molecules.
Synthesis and characterization of biodegradable polyurethanes with folate side chains conjugated to hard segments
Authors: Pan Zhicheng , Yu Lunquan , Song Nijia , Zhou Lijuan , Li Jiehua , Ding Mingming , Tan Hong , Fu Qiang
Published: December 2013

In this study, a novel folate-conjugated chain extender (LDDFA) was designed and synthesized to enhance site-specific intracellular delivery of drug carriers against folate receptor overexpressing tumors.
On the origin of the low temperatures resistivity minimum in Cr thin films
Authors: Osquiguil E. , Tosi L. , Kaul E. E. , Balseiro C. A.
Published: December 2013

We present measurements of the electrical resistivity and Hall coefficient, ρ and RH, in Cr films of different thicknesses grown on MgO (100) substrates, as a function of temperature T and applied magnetic field H. The results show a low temperature minimum in ρ(T), which is thickness dependent. From 40 K to 2 K, the Hall coefficient is a monotonous increasing function as T is reduced with no particular signature at the temperature Tmin where the minimum develops. We explain the resistivity minimum assuming an imperfect nesting of the Fermi surface leading to small electron and hole pockets. We introduce a phenomenological model which supports this simple physical picture.
Neoclassical toroidal viscosity in perturbed equilibria with general tokamak geometry
Authors: Logan Nikolas C. , Park Jong-Kyu , Kim Kimin , Wang Zhirui , Berkery John W.
Published: December 2013

This paper presents a calculation of neoclassical toroidal viscous torque independent of large-aspect-ratio expansions across kinetic regimes. The Perturbed Equilibrium Nonambipolar Transport (PENT) code was developed for this purpose, and is compared to previous combined regime models as well as regime specific limits and a drift kinetic δf guiding center code. It is shown that retaining general expressions, without circular large-aspect-ratio or other orbit approximations, can be important at experimentally relevant aspect ratio and shaping. The superbanana plateau, a kinetic resonance effect recently recognized for its relevance to ITER, is recovered by the PENT calculations and shown to require highly accurate treatment of geometric effects.
Random-phase approximation correlation energies from Lanczos chains and an optimal basis set: Theory and applications to the benzene dimer
Authors: Rocca Dario
Published: December 2013

A new ab initio approach is introduced to compute the correlation energy within the adiabatic connection fluctuation dissipation theorem in the random phase approximation. First, an optimally small basis set to represent the response functions is obtained by diagonalizing an approximate dielectric matrix containing the kinetic energy contribution only. Then, the Lanczos algorithm is used to compute the full dynamical dielectric matrix and the correlation energy. The convergence issues with respect to the number of empty states or the dimension of the basis set are avoided and the dynamical effects are easily kept into account. To demonstrate the accuracy and efficiency of this approach the binding curves for three different configurations of the benzene dimer are computed: T-shaped, sandwich, and slipped parallel.
Beam loading in a laser-plasma accelerator using a near-hollow plasma channel
Authors: Schroeder C. B. , Benedetti C. , Esarey E. , Leemans W. P.
Published: December 2013

Beam loading in laser-plasma accelerators using a near-hollow plasma channel is examined in the linear wake regime. It is shown that, by properly shaping and phasing the witness particle beam, high-gradient acceleration can be achieved with high-efficiency, and without induced energy spread or emittance growth. Both electron and positron beams can be accelerated in this plasma channel geometry. Matched propagation of electron beams can be achieved by the focusing force provided by the channel density. For positron beams, matched propagation can be achieved in a hollow plasma channel with external focusing. The efficiency of energy transfer from the wake to a witness beam is calculated for single ultra-short bunches and bunch trains.
Ergodicity of the generalized lemon billiards
Authors: Chen Jingyu , Mohr Luke , Zhang Hong-Kun , Zhang Pengfei
Published: December 2013

In this paper, we study a two-parameter family of convex billiard tables, by taking the intersection of two round disks (with different radii) in the plane. These tables give a generalization of the one-parameter family of lemon-shaped billiards. Initially, there is only one ergodic table among all lemon tables. In our generalized family, we observe numerically the prevalence of ergodicity among the some perturbations of that table. Moreover, numerical estimates of the mixing rate of the billiard dynamics on some ergodic tables are also provided.
Giant magnetostriction in Tb-doped Fe83Ga17 melt-spun ribbons
Authors: Wu Wei , Liu Jinghua , Jiang Chengbao , Xu Huibin
Published: December 2013

Giant magnetostriction is achieved in lightly Tb-doped Fe83Ga17 melt-spun ribbons. The average perpendicular magnetostriction λ⊥ is −886 ppm along the melt-spun ribbon direction in the Fe82.89Ga16.88Tb0.23 alloy and the calculated parallel magnetostriction λ|| is 1772 ppm. These values are more than four times as large as those found in binary Fe83Ga17. The enhanced magnetostriction is attributed to a small amount of Tb entering solution in the A2 matrix phase during rapid solidification. The strong localized magnetocrystalline anisotropy of terbium is thought to cause the giant magnetostriction.
Sharp semiconductor-to-metal transition of VO2 thin films on glass substrates
Authors: Jian Jie , Chen Aiping , Zhang Wenrui , Wang Haiyan
Published: December 2013

Outstanding phase transition properties of vanadium dioxide (VO2) thin films on amorphous glass were achieved and compared with the ones grown on c-cut sapphire and Si (111) substrates, all by pulsed laser deposition. The films on glass substrate exhibit a sharp semiconductor-to-metal transition (∼4.3 °C) at a near bulk transition temperature of ∼68.4 °C with an electrical resistance change as high as 3.2 × 103 times. The excellent phase transition properties of the films on glass substrate are correlated with the large grain size and low defects density achieved. The phase transition properties of VO2 films on c-cut sapphire and Si (111) substrates were found to be limited by the high defect density.
Diameter and wall number control of carbon nanotubes by chemical vapor deposition
Authors: Xie Rongsi , Zhong Guofang , Zhang Can , Chen Bingan , Santiago Esconjauregui C. , Robertson John
Published: December 2013

We analyze the relationship between the average wall number (N) and the diameter (d) for carbon nanotubes (CNTs) grown by chemical vapour deposition. It is found that N depends linearly on d for diameters in the range of 2.5–10 nm, while single wall nanotubes predominate for diameters under about 2.1 nm. The linear relationship is found to depend somewhat on the growth conditions. It is also verified that the mean diameter depends on the diameter of the originating catalyst nanoparticle, and thus on the initial catalyst thickness where a thin film catalyst is used. This simplifies the characterisation of CNTs by electron microscopy. We also find a linear relationship between nanotube diameter and initial catalyst film thickness.
Introduction to Focus Issue: Rhythms and Dynamic Transitions in Neurological Disease: Modeling, Computation, and Experiment
Authors: Kaper Tasso J. , Kramer Mark A. , Rotstein Horacio G.
Published: December 2013

Rhythmic neuronal oscillations across a broad range of frequencies, as well as spatiotemporal phenomena, such as waves and bumps, have been observed in various areas of the brain and proposed as critical to brain function. While there is a long and distinguished history of studying rhythms in nerve cells and neuronal networks in healthy organisms, the association and analysis of rhythms to diseases are more recent developments. Indeed, it is now thought that certain aspects of diseases of the nervous system, such as epilepsy, schizophrenia, Parkinson's, and sleep disorders, are associated with transitions or disruptions of neurological rhythms. This focus issue brings together articles presenting modeling, computational, analytical, and experimental perspectives about rhythms and dynamic transitions between them that are associated to various diseases.
p-doping-free InGaN/GaN light-emitting diode driven by three-dimensional hole gas
Authors: Zhang Zi-Hui , Tiam Tan Swee , Kyaw Zabu , Liu Wei , Ji Yun , Ju Zhengang , Zhang Xueliang , Wei Sun Xiao , Volkan Demir Hilmi
Published: December 2013

Here, GaN/AlxGa1-xN heterostructures with a graded AlN composition, completely lacking external p-doping, are designed and grown using metal-organic-chemical-vapour deposition (MOCVD) system to realize three-dimensional hole gas (3DHG). The existence of the 3DHG is confirmed by capacitance-voltage measurements. Based on this design, a p-doping-free InGaN/GaN light-emitting diode (LED) driven by the 3DHG is proposed and grown using MOCVD. The electroluminescence, which is attributed to the radiative recombination of injected electrons and holes in InGaN/GaN quantum wells, is observed from the fabricated p-doping-free devices. These results suggest that the 3DHG can be an alternative hole source for InGaN/GaN LEDs besides common Mg dopants.
Cooperative assembly of IFI16 filaments on dsDNA provides insights into host defense strategy
Authors: Morrone Seamus R. , Wang Tao , Constantoulakis Leeza M. , Hooy Richard M. , Delannoy Michael J. , Sohn Jungsan
Published: December 2013

Significance

Human IFN-inducible protein-16 (IFI16) is an essential intracellular foreign DNA receptor of innate immunity and also implicated in several autoimmune disorders. However, little is known about molecular mechanisms that underlie its function. We show here that IFI16 cooperatively assembles into filaments on dsDNA. IFI16 thus oligomerizes even in the presence of excess DNA, and it is the non–DNA-binding pyrin domain of IFI16 that drives the filament assembly. These results provide unifying mechanistic explanations for several previous in vivo observations regarding IFI16 and also suggest that assembling filaments on foreign nucleic acids is a broad host defense strategy.
Crystal structures of a pentameric ligand-gated ion channel provide a mechanism for activation
Authors: Sauguet Ludovic , Shahsavar Azadeh , Poitevin Frédéric , Huon Christèle , Menny Anaïs , Nemecz Àkos , Haouz Ahmed , Changeux Jean-Pierre , Corringer Pierre-Jean , Delarue Marc
Published: December 2013

Significance

We describe the X-ray structures of the same pentameric ligand-gated ion channel (pLGIC) in both its liganded or ligand-free conformations. This provides the molecular basis for understanding the opening and closing (gating mechanism) of these key players in the fast transmission of chemical signals at synapses. As described with classical allosteric proteins, the tertiary changes of the subunits are linked together through the quaternary constraint by a marked reorganization of the interfaces between subunits and the associated binding pockets and cavities. The closed form displays a cavity that may allow a better understanding of the mechanism of action of pharmacological effectors of pentameric ligand-gated ion channels and the rational design of new modulators.