bluuebunny/crossref_metadata_2025 huggingface dataset:
Detailed spectroscopic analysis of complex multi‐component materials using a combination of Raman mapping with BTEM
Authors: Widjaja Effendi , Garland Marc
Published: March 2012

The combined application of Raman microscopy and self‐modeling curve resolution techniques can address a wide range of material characterization problems. In particular, the combination of Raman microscopy and the Band‐Target Entropy Minimization (BTEM) algorithm has been applied to various organic, inorganic, pharmaceutical and bio‐material related problems. In the present contribution, the principles behind this type of analysis are reviewed, followed by a number of case‐by‐case studies. For each of these examples, a Raman microscopic mapping measurement (consisting of 100 s up to 1000 s of spectra) is performed, followed by BTEM analysis which provides the underlying pure component spectra of the constituents present in the system without the use of any a priori information. In most cases, outstanding signal‐to‐noise ratios for components at the 0.1‐1.0 % level can be obtained, and sometimes trace constituents can also be detected. Subsequently, the identity of the components can be determined by comparison to spectral libraries. Finally, the reconstructed pure component spectra can be further used to obtain the spatial distribution of the constituents present in the sample. Copyright © 2012 John Wiley & Sons, Ltd.
Thinking outside the classical chain reaction box of lipid oxidation
Authors: Schaich Karen M.
Published: March 2012

For the past few decades, research on lipid oxidation mechanisms has been rather stagnant due to a pervasive attitude that reactions of lipid oxidation were well understood, so only tailoring applications of basic knowledge to stabilize individual systems was needed. This simplistic approach worked during the low fat/no fat era because there was little lipid substrate to oxidize. However, with current reformulation of foods with polyunsaturated fatty acids for health, preventing oxidation of these essential fatty acids presents major challenges that cannot always be solved with traditional thinking. Because critical gaps in our understanding prevent moving forward with improved processing, formulations, and packaging to provide high‐PUFA lipid foods that remain shelf‐stable beyond a few months, details about oxidation mechanisms that were previously considered irrelevant have now become critically important. Considered here are alternate reaction pathways that compete with classical hydrogen abstraction and must be integrated into the overall free radical chain to more accurately account for kinetics and products of lipid oxidation.
Alternatives to tropical fats based on high‐stearic sunflower oils
Authors: Garcés Rafael , Martínez‐Force Enrique , Salas Joaquín J. , Bootello Miguel A.
Published: March 2012

New high‐oleic high‐stearic sunflower lines produce oils that could be a source of disaturated triacylglycerol alternatives to tropical fats. These oils can be fractionated to produce stearins enriched in stearic acid with physical properties similar to cocoa butter and other confectionary fats without hydrogenation or transesterification. These fats can be produced in temperate countries from a well‐established crop like sunflower, and represent a healthy source of saturated fatty acids.
The Effects of Nanofiber Topography on Astrocyte Behavior and Gene Silencing Efficiency
Authors: Cao Haoqing , Marcy Guillaume , Goh Eyleen Lay Keow , Wang Feng , Wang Jun , Chew Sing Yian
Published: March 2012

Astrocyte‐nanofiber interactions are studied by culturing primary rat cortical astrocytes on poly[caprolactone‐co‐(ethyl ethylene phosphate)] electrospun nanofibers and solvent‐cast films (two‐dimensional control). The results indicate that nanofiber topography significantly suppresses astrocyte proliferation and enhances apoptosis, without altering cellular activation as compared to films. Moreover, nanofiber topography enhances gene‐silencing efficiency in astrocytes. The results suggest that nanofibers may serve as potential substrates for nerve regeneration by suppressing astrocyte growth and may further facilitate the use of gene‐silencing to enhance CNS regeneration.

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Imaging measures predict progression in progressive supranuclear palsy
Authors: Whitwell Jennifer L. , Xu Jia , Mandrekar Jay , Gunter Jeffrey L. , Jack Clifford R. , Josephs Keith A.
Published: March 2012

Objective:

The aim of this work was to determine whether the progressive supranuclear palsy rating scale, a measure of disease severity, is associated with neuroanatomical changes in progressive supranuclear palsy.

Methods:

We recruited 22 subjects with probable progressive supranuclear palsy who completed the progressive supranuclear palsy rating scale at 2 time points. All subjects had magnetic resonance imaging and diffusion tensor imaging. Associations were assessed between whole brain volume, ventricular volume, midbrain area and superior cerebellar peduncle fractional anisotropy, and baseline/change of the progressive supranuclear palsy rating scale.

Results:

Superior cerebellar peduncle fractional anisotropy correlated with the total score and gait/midline subscore of the progressive supranuclear palsy rating scale. Whole brain volume, midbrain area, and disease duration predicted subsequent change over time in the gait/midline subscore of the progressive supranuclear palsy rating scale.

Conclusions:

Imaging measures could be useful to help predict clinical progression in subjects with progressive supranuclear palsy. © 2012 Movement Disorder Society
A CPW FED planar monopole antenna with modified H shaped slot for WLAN/Wi‐MAX application
Authors: Ghatak Rowdra , Goswami C. , Mishra R. K. , Poddar D. R.
Published: March 2012

A planar monopole antenna with dual wideband resonance characteristics is presented that simultaneously satisfies wireless local area network (802.11 a/b) and Wi‐MAX applications. The proposed antenna structure consists of a rectangular monopole beveled at the base with a modified H shaped slot and occupies an area of 32 × 51.5 mm2. The measured realized gain is around 2.0 dBi in the lower band (2.35–2.80 GHz) and about 3.8 dBi in the upper band (3.28–5.95 GHz). © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1296–1301, 2012
A compact UWB slot antenna with signal rejection in 5–6 GHz band
Authors: Subbarao Akkala , Raghavan S.
Published: March 2012

In this article, a novel planar slot antenna is presented with band‐notched characteristic for ultra wideband applications.The antenna is fed by coplanar wave guide. A “C” shaped slot etched on the radiating patch to avoid interference from WLAN and HYPERLAN/2 bands. The antenna has measured bandwidth ranging from 3 to 10.6 GHz for VSWR ≤ 2. The antenna has omni directional radiation pattern in H‐plane and bi‐directional in E‐plane. The group delay of antenna is less than 1 ns except in the notched band. Good agreement is found between measured and simulated results. The antenna can be easily integrated with microwave circuitry and is a good for UWB applications. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1292–1296, 2012
A triple gain mode digitally controlled amplifier in cmos process
Authors: Park Bonghyuk , Jung Jaeho
Published: March 2012

A high dynamic range, wide‐band triple gain mode amplifier has been developed using CMOS 0.18‐μm technology.The proposed low‐noise amplifier (LNA) consists of feedback architecture in the first stage and cascode topology in the second stage. The frequency response of 2.0–3.5 GHz is demonstrated in this work. In high‐gain mode, measured results show a noise figure (NF) of 2.6–2.9 dB, gain of 25.4–28.2 dB, and input P1dB of −19.0 dBm with 10.9 mA DC current. In mid‐gain mode, the LNA achieves 4.2–6.5 dB NF and 21.3–22.5 dB gain with 11.0 mA current consumption. In low‐gain mode, 6.7–8.5 dB NF, 10.2–12.5 dB gain, and −10 dBm input P1dB with 11.0 mA current are realized. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1263–1266, 2012
Hybrid integration of 4‐W and 8‐W S‐band GaN power amplifiers on a selectively anodized aluminum substrate
Authors: Kim Dong‐Wook
Published: March 2012

Hybrid integration of 4‐W and 8‐W GaN power amplifiers operating in 2–3 GHz is attempted on a selectively anodized aluminum substrate. Discrete GaN high electron mobility transistors are inserted in selectively etched pockets of the aluminum metal substrate and all passive matching circuits are fabricated on the anodized aluminum oxide layer of the aluminum substrate. The 4‐W power amplifier shows a flat gain of 20–23 dB in 0.7–4.5 GHz, a maximum output power of 37.5 dBm at 2.5 GHz, and output power variation of ±0.35 dB in 2–3 GHz. The 8‐W power amplifier also shows a maximum output power of 39.6 dBm at 2.5 GHz and output power variation of ±0.5 dB in 2–3 GHz. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1261–1263, 2012
Investigation of spatial filters at microwave frequencies: Application for antenna directivity enhancement
Authors: Yahiaoui Riad , Burokur Shah Nawaz , Vigneras Valérie , de Lustrac André , Mounaix Patrick
Published: March 2012

We report the theoretical and experimental investigations of a frequency selective surface (FSS) operating in the microwave regime. Numerical simulations using finite element method and reflection–transmission microwave measurements have been performed and a good quantitative agreement has been observed. Angular robustness is also demonstrated which makes it promising in telecommunication applications. The potential application of the FSS as a partially reflecting surface (PRS) reflector Fabry–Pérot (FP) cavity is proposed and evaluated. Measured return losses and radiations patterns done in an anechoic chamber agree very well with the simulated ones. A high directivity of 20 dBi is observed for the FP cavity. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1327–1332, 2012
Noncontact detection of the location of buried conductive grids with pulsed THz wave
Authors: Chang Yun‐ching , Gao Yaohui , Wang Chao , Yao Jimmy , Cheng Jiping , Yin Stuart , Ruffin Paul , Brantley Christina , Edwards Eugene , Luo Claire
Published: March 2012

In this article, a new method for precisely measuring the location of buried conductive grid based on time‐domain pulsed terahertz (THz) reflectometry is presented. The location of the buried conductive grid is determined by the time difference of reflected THz pulses between the front surface and the buried conductive grid. Since the wavelength of THz wave is usually larger than the roughness of unpolished optical surface and the period of conductive grid, the proposed method is insensitive to the surface condition. Furthermore, this is a non‐contact and real‐time measurement technique. The experimental result indicates that the accuracy of the measurement is at least on the order of 10 μm. Such kind of technique will be very helpful for enhancing the quality and reduce the cost of fabricating electro‐optic windows with embedded conductive grids and/or wires. It can also be beneficial for some other applications. For example, since there are often embedded conductive wires in explosive devices, it can be used to detect the explosive devices because the proposed method can remotely determine the dimensions and locations of conductive wires embedded in dielectric enclosures. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1135–1138, 2012
Miniaturization cantor set fractal ultrawideband antenna with a notch band characteristic
Authors: Li Yingsong , Yang Xiaodong , Liu Chengyuan , Jiang Tao
Published: March 2012

A CPW‐fed wide slot ultrawideband antenna with notch band characteristic is presented numerically and experimentally. The radiation patch is implemented using Cantor set fractal technology. By setting two symmetrical triangular tapered corners at the bottom of the wide slot, the impedance bandwidth of the proposed antenna can be enhanced. In addition, a T‐shaped tuning stub suspends at the top of the wide slot to achieve the notch band characteristic. Experimental and numerical results show that the proposed antenna, with compact size of 26 × 21 mm2, has an impedance bandwidth range from 2.8 to 11 GHz for voltage standing‐wave ratio less than 2, except the rejected band 5–6.3 GHz. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1227–1230, 2012
A 3.1‐dB NF, 21.31 dB gain micromachined 3–10 GHz distributed amplifier for UWB systems in 0.18‐μm CMOS technology
Authors: Lin Yo‐Sheng , Chang Jin‐Fa , Huang Pen‐Li , Lu Shey‐Shi
Published: March 2012

A high‐gain and low‐noise micromachined CMOS distributed amplifier (DA) using cascaded gain cell, which constitutes an inductively parallel‐peaking cascode‐stage with a low‐Q RLC load and an inductively series‐peaking common‐source stage, is demonstrated.Flat and high S21 and flat and low noise figure (NF) are achieved simultaneously by adopting a slightly under‐damped Q‐factor for the second‐order transconductance frequency response of the proposed cascaded gain cell. The two‐stage DA consumes 37.8 mW and achieves flat and high S21 of 20.47 ± 0.72 dB with an average NF of only 3.3 dB over the 3∼10 GHz band of interest, one of the best reported NF performances for a CMOS UWB DA or LNA in the literature. In addition, the result shows that a 0.84‐dB increase in average S21 (from 20.47 to 21.31 dB) and a 0.2‐dB decrease (from 3.3 to 3.1 dB) in average NF are achieved mainly due to the improvement of the quality factor of the inductors in the DA. This means that this DA architecture in conjunction with the backside ICP dry‐etching technique is very promising for high‐performance 3∼10 GHz UWB communication systems. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1163–1167, 2012
Novel tunable single‐longitunal mode fiber ring laser with two FBG‐FP filters
Authors: Du Yong , Dong Xiaopeng , Chen Minxiu , Zhou Jinlong
Published: March 2012

Using a pair of fiber Bragg grating Fabry‐Pérot filters (FBG‐FP) as its wavelength‐selective components based on the Vernier effect, a novel single longitudinal, discretely tunable and stable fiber ring laser is proposed in this letter.We studied the characteristics of this sort of tunable fiber laser both theoretically and experimentally, and obtained eight single‐wavelength lasing from 1550.840 to 1551.762 nm with an average of 96 pm spacing by pulling the Tunable FBG‐FP. The output spectrum of the single‐wavelength lasing is specified by the transmission maximum of the fixed FBG‐FP and recorded automatically by the optical spectrum analyzer at an interval of 1 min. It is found that the output wavelength drift within a few picometers, and the fluctuation of the output power is less than 0.1 dB. This sort of fiber ring laser has potential applications in optical communications and sensors. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1230–1234, 2012
A 30–65 GHz wideband double‐balanced gilbert‐cell mixer using GaAs pHEMT technology
Authors: Kao Hsuan‐Ling , Ke J.Y. , Yeh C. S. , Chiu Hsien‐Chin , Fu Jeffrey S.
Published: March 2012

This article presents a wideband, double‐balanced microwave/millimeter‐wave Gilbert‐cell mixer, using 0.15 μm GaAs pHEMT technology. Two baluns and a matching network are used in RF‐ and LO‐ports to convert single‐ended signals to differential signals, for wideband use. This mixer demonstrates an average conversion gain is 2.22 ± 1.5 dB at PLO = 2 dBm, from 30 to 65 GHz. The LO‐to‐RF and LO‐to‐IF isolations are all better than 28 dB, between 30 and 65 GHz. The measured P1dB and IIP3 are 5 dBm at 40 GHz and 10 dBm at 60 GHz, respectively. The mixer occupies a chip area, including probing pads, of 1.68 mm2 and consumes 21 mA, with a supply voltage of 5V. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1196–1200, 2012
Compact ultra‐wideband bandpass filter with new coupled line structure for wireless
Authors: Shaman Hussein
Published: March 2012

In this letter, a new ultra‐wideband bandpass filter using microstrip parallel coupled line structure is proposed. The filter is constructed of only two sections of three‐coupled lines, which is a quarter wavelength long at the midband frequency. In addition, one of the outer coupled lines of each section is shorted to the ground. As a result, the filter exhibits two new symmetric transmission zeros around the passband, which increase the selectivity of both edges of the passband significantly. The transmission zeros can be located at the desired frequency by adjusting the width or the length of the coupled lines or also by changing the gap between them. The desired bandwidth can be obtained where the bandwidth is reversely proportional to the gap between the coupled lines. The design is successfully realized verified by full‐wave electromagnetic simulation and the experiment. A good agreement between the expected and measured results is obtained, and it validates the efficiency of the proposed new coupled line structure and corresponding filter design technique. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1319–1321, 2012
Single walled carbon nanotube bolometer coupled to a Sierpinski fractal antenna for the detection of megahertz radiation
Authors: Vera‐Reveles Gustavo , Simón Jorge , Briones Edgar , González Francisco J.
Published: March 2012

In this article, the receiving properties of a fractal antenna coupled to a film of single‐walled carbon nanotubes used as a bolometer are numerically and experimentally investigated in the megahertz frequency region. The numerical results show resonant frequencies at 420 and 1710 MHz, close to the 500 and 1600 MHz resonant frequencies obtained experimentally, the responsivity of the devices was calculated at 0.178 V/W at 610 MHz for an ibias of 0.3 μA. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1251–1253, 2012
Acoustic dispersion measurement for a single‐mode‐fiber‐based acoustooptic tunable filter excited by flexural acoustic wave
Authors: Zhang Hao , Liu Bo , Lin Wei , Dong Hongguang , Liu Lihui
Published: March 2012

An experimental approach to directly measure acoustic dispersion for a single‐mode‐fiber‐based acoustooptic tunable filter excited by flexural acoustic wave has been proposed and experimentally demonstrated. The cladding modes that participate in the mode coupling process have been ascertained by using the phase matching condition. And based on experimental observation of transmission spectral response to applied frequency, acoustic phase velocity as a function of applied radiation frequency signal frequency has been obtained. Furthermore, averaged acoustic dispersion across different cladding modes indicates that acoustic round frequency linearly increases with the increment of acoustic propagation constant with a coefficient of determination of 0.99941. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1281–1285, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26790
Physical interpretation of negative characteristic resistances associated with lossless periodic transmission line structures
Authors: Lamultree Suthasinee , Torrungrueng Danai
Published: March 2012

This article presents a physical interpretation of negative characteristic resistances (NCRs) associated with lossless periodic transmission line (TL) structures using the model of conjugately characteristic‐impedance transmission lines (CCITLs).Interestingly, the CCITL model of lossless periodic TL structure can exhibit both non‐negative characteristic resistances (NNCR) and NCRs with appropriate propagation constants. Nevertheless, the physical meaning for the NCR case is still ambiguous. To physically interpret the NNCR and NCR cases, it is found that the propagation constant plays an important role. In addition, the suitable definitions of incident and reflected waves for both NNCR and NCR cases are also provided. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1180–1183, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26796
A high‐performance ibc‐Hub transceiver for intra‐body communication system
Authors: Lin Yo‐Sheng , Wang Chien‐Chin , Chen Chi‐Chen , Hsiao Chung‐Chih , Chou Yi‐Hsuan
Published: March 2012

We report a high‐performance intra‐body communication hub (IBC‐hub) transceiver for IBC system, consisting of an on–off keying (OOK) transmitter and a clock and data recovery (CDR) receiver. We also demonstrate the signal transmission model of IBC. The OOK transmitter in the IBC‐hub takes commands from the RF gateway, and then transmits them to the sensor node biomedical system‐on‐a‐chip (SOC) through human body. The CDR receiver in the IBC‐hub receives the biomedical signals (in digital format) from the sensor node biomedical SOC through human body, and then transfers them to the RF gateway through the micro‐control unit. Such kind of transmission methodology in conjunction with our proposed IBC network is much more power‐efficient than wireless communication. Moreover, since no antenna is required, small chip size is achieved. The OOK transmitter consumes 12.7 mW and achieves an output power of −11.36 dBm at 433 MHz. At supply voltage of 3 V, the CDR receiver consumes 2.2 mW and achieves RMS jitter and eye height (of the data eye diagram) of 1.81 ns and 2.747 V, respectively, in the condition of locking to a 2 Mb/s pseudo‐random binary sequence with length of 27 − 1. The measured bit‐error rate in IBC transmission is 2.44 × 10−9, better than previous work in the literature. The excellent results indicate the IBC‐hub transceiver is suitable for IBC system. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1143–1153, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26797
How should bladder sensation be measured?: ICI‐RS 2011
Authors: De Wachter S. , Smith P. , Tannenbaum C. , Van Koeveringe G. , Drake M. , Wyndaele J.J. , Chapple C.
Published: March 2012

Aims

Disturbed bladder sensations, or in broader terms, sensory dysfunctions are increasingly recognized as key elements in the origin and manifestation of symptom syndromes of urinary dysfunction. Adequate assessment of bladder sensation is crucial to improve our understanding of the pathophysiology and treatment of urinary dysfunction. This manuscript summarizes the discussions of a think tank on “How to measure bladder sensation” held at the ICI‐RS meeting in 2011.

Methods

Based upon literature reviews on bladder sensation presented at the think tank in the ICI‐RS meeting, discussions evolved which were summarized in the ICI‐RS report. Different physicians/researchers further elaborated on this report, which is presented in this manuscript.

Results

Bladder sensations are not merely the result of bladder distension. Other factors inside the bladder or bladder wall: central processing and/or cognitive manipulation may play an important role. Current methods to measure sensations such as urodynamics, voiding diaries, forced diuresis, electrical stimulation and brain imaging are likely sub‐optimal as they only consider part of these factors in isolation.

Conclusions

Different methods to measure bladder sensations have been described and are used in clinical practice. Current methods only address part of the parameters responsible for the generation and perception of urinary sensations. Further focused research is required, and several recommendations are provided. Neurourol. Urodynam. 31:370–374, 2012. © 2012 Wiley Periodicals, Inc.
The adult urology perspective on management of stress urinary incontinence in pediatric urology: ICI‐RS 2011
Authors: Drake Marcus J.
Published: March 2012

The modern era of patient‐centered, multidisciplinary professional practice comes with the expectation of effective interaction between specialties dealing with closely related clinical areas. Interaction between adult and pediatric urology is generally limited in terms of training, conferences, and joint diagnostic/treatment algorithms. However, in the more complex cases managed by pediatric urologists, long‐term medical input is commonly necessary. Accordingly, regular interaction between the relevant specialties would be beneficial for continuity of care of individual patients, achieving best results at transition to adolescence, awareness of long‐term outcome of pediatric urological procedures and development of new surgical techniques. This article reviews the discussions at the 2011 International Consultation on Incontinence Research Society meeting in Bristol. Neurourol. Urodynam. 31:384–385, 2012. © 2012 Wiley Periodicals, Inc.
Can we, and do we need to, define bladder neck hypermobility and intrinsic sphincteric deficiency?: ICI‐RS 2011
Authors: Smith Phillip P. , van Leijsen Sanne A.L. , Heesakkers John P.F.A. , Abrams Paul , Smith Anthony R.B.
Published: March 2012

Aims

Bladder neck hypermobility (BNH, also called urethral hypermobility), and intrinsic sphincteric deficiency (ISD) are terms frequently used in the clinical evaluation and management of stress urinary incontinence, and as subject qualifiers in clinical research. The terms also infer pathophysiologic concepts, as BNH and ISD appear to represent two different aspects of failure of the continence mechanism. Unfortunately, neither term is well‐defined, and the various clinical and urodynamic characterizations of these terms do not correlate well with one another.

Methods

The value of these concepts and these specific terms was debated at the ICI‐RS meeting, Bristol, UK, June 2011. Two clinicians were asked to take opposing viewpoints, with three weeks lead‐time prior to the meeting. Each discussant presented one viewpoint, “for” or “against,” followed by a brief discussion to review the presentations.

Results

The consensus was that, while we currently cannot adequately define these terms, there is a need to develop terminology employing these concepts.

Conclusions

Terminology should permit improved definition of the sphincteric mechanism, allow individual patient characterization and serve as useful waypoints in treatment decisions. Neurourol. Urodynam. 31:309–312, 2012. © 2012 Wiley Periodicals, Inc.
Fostering artistic ensemble performance: Exploring the role of transformational leadership
Authors: Boerner Sabine , Gebert Diether
Published: March 2012

Although empirical studies suggest that a transformational leadership style is efficient in orchestras, a coherent explanation for this finding is lacking. Linking research on workforce diversity with research on team innovation, this article provides a framework that explains the positive effects of transformational leadership in orchestras. Transformational leaders enhance the positive effects of ensemble diversity on idea generation, while at the same time reducing its negative effects on idea integration. This twofold effect of transformational leadership promotes artistic ensemble performance, that is, a coherent, highly synchronized interpretation of a given score. Contributions to the literature and implications for further research are formulated.
Volunteers and the risk of posttraumatic stress disorder
Authors: Jaffe Eli , Sasson Uzi , Knobler Haim , Aviel Einat , Goldberg Avishy
Published: March 2012

Symptoms of posttraumatic stress disorder (PTSD) result from exposure to a traumatic event and influence a person's ability to cope psychologically. Recent documentation from emergency rooms shows that medical personnel, including volunteers who treated severely injured people, can develop symptoms of PTSD even though the volunteers themselves were not personally subjected to the stressful event. This article finds similar results among adolescents who volunteered with Magen David Adom (MDA), Israel's national emergency medical, disaster, ambulance, and blood bank service. Because of the security threats Israel has faced, these adolescents are likely to be exposed to traumatic events during their volunteer service, and some may develop PTSD. This article explores who is most susceptible to developing PTSD and the underlying theories of why that may be the case. Since the adolescents' motives to volunteer vary, the article proposes that volunteers with certain motives retain their enthusiasm for volunteering despite the danger of developing PTSD symptoms. It also finds that some of the motives to volunteer correlated with a reduction in the level of PTSD symptoms. Understanding the adolescents' motivations to volunteer will help nonprofit leaders and managers allocate volunteers according to their motivations and the levels of threat a particular job entails.
Colloidal Synthesis of Gold Semishells
Authors: Rodríguez‐Fernández Denis , Pérez‐Juste Jorge , Pastoriza‐Santos Isabel , Liz‐Marzán Luis M.
Published: March 2012

This work describes a novel and scalable colloid chemistry strategy to fabricate gold semishells based on the selective growth of gold on Janus silica particles (500 nm in diameter) partly functionalized with amino groups. The modulation of the geometry of the Janus silica particles allows us to tune the final morphology of the gold semishells. This method also provides a route to fabricating hollow gold semishells through etching of the silica cores with hydrofluoric acid. The optical properties were characterized by visible near‐infrared (vis‐NIR) spectroscopy and compared with simulations performed using the boundary element method (BEM). These revealed that the main optical features are located beyond the NIR region because of the large core size.
Identifying and Acting on Early Warning Signs in Complex Projects
Authors: Williams Terry , Klakegg Ole Jonny , Walker Derek H. T. , Andersen Bjørn , Magnussen Ole Morten
Published: March 2012

We consider identification of early warning signs (EWS) in projects. Project professionals are not good at detecting or acting on EWS. Barriers that lead to this are identified. The nature of EWS and their detection change with the evolving situation. Project assessments, typically part of gateways, are useful in identifying EWS connected to the formalities of the project. As complexity increases, assessments have more limited use, and the project is increasingly dependent on detecting EWS by informal “gut feeling.” Thus, knowledge, experience, and communication skills are increasingly important in complex situations. We conclude with a list of early warning signs.
Silole‐containing poly(silylenevinylene)s: Synthesis, characterization, aggregation‐enhanced emission, and explosive detection
Authors: Zhao Zujin , Jiang Tao , Guo Yanju , Ding Liyuan , He Bairong , Chang Zhengfeng , Lam Jacky W. Y. , Liu Jianzhao , Chan Carrie Y. K. , Lu Ping , Xu Liwen , Qiu Huayu , Tang Ben Zhong
Published: March 2012

Hydrosilylation polymerizations of 1,1‐dimethyl‐2,5‐bis(4‐ethynylphenyl)‐3,4‐diphenylsilole with aromatic silylhydrides including 1,4‐bis(dimethylsilyl)benzene, 4,4′‐bis(dimethylsilyl)biphenyl, 2,5‐bis(dimethylsilyl)thiophene, and 2,7‐bis(dimethylsilyl)‐9,9‐dihexylfluorene in the presence of Rh(PPh3)3Cl catalyst in refluxed tetrahydrofuran afford a series of silole‐containing poly(silylenevinylene)s. Under optimum condition, the alkyne polyhydrosilylation reactions progress efficiently and regioselectively, yielding polymers with high molecular weights (Mw up to 95,300) and good stereoregularity (E content close to 99%) in high yields (up to 92%). The polymers are processable and thermally stable, with high decomposition temperatures in the range of 420−449 °C corresponding to 5% weight loss. They are weakly fluorescent in the solution state but become emissive in the aggregate and film states, demonstrating their aggregation‐enhanced emission characteristics. The explosive sensing capabilities of the polymers are examined in both solution and aggregate states. The emissions of the polymers aggregates in aqueous mixture are quenched more efficiently by picric acid in an exponential pattern with high quenching constants (up to 27,949 L mol−1), suggesting that the polymers aggregates are sensitive chemosensors for explosive detection. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Effect of precursor chain‐length on the formation and stability of poly(ethylene glycol)‐based supramolecular star polymers
Authors: Gadwal Ikhlas , De Swati , Stuparu Mihaiela C. , Jang Se Gyu , Amir Roey J. , Khan Anzar
Published: March 2012

A homologous series of guanosine end‐functionalized poly(ethylene glycol)s have been prepared, and their assembly–disassembly behavior in the presence of potassium cations has been systematically examined upon changing the concentration, temperature, nature of solvent, amount of cation, and type of anion using 1H‐NMR, UV/Vis, and circular dichroism spectroscopy. The results revealed a strong dependence of the assembly formation, and the stability of the formed supramolecular ensemble on the chain‐length of the assembly precursor. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Associations between cancer‐related financial stress and strain and psychological well‐being among individuals living with cancer
Authors: Sharp Linda , Carsin Anne‐Elie , Timmons Aileen
Published: March 2012

Background

Cancer places a financial and economic burden on individuals, but relatively little is known about the consequences. We investigated associations between cancer‐related financial stress and strain and psychological well‐being.

Methods

Individuals >6 months post‐diagnosis with breast, prostate and lung cancer, identified from the National Cancer Registry Ireland, completed a postal questionnaire. Financial stress was assessed by the impact of the cancer diagnosis on household ability to make ends meet, financial strain by feelings about household financial situation since the cancer diagnosis and psychological well‐being (depression, anxiety and distress) by the Depression Anxiety Stress Scales‐21. Logistic regression was used to identify associations between financial stress and strain and depression, anxiety and distress of (a) any severity and (b) severe or worse.

Results

The response rate was 54%. Of 654 respondents, 49% reported increased financial stress and 32% increased financial strain due to cancer. Depression, anxiety and distress were present in: 36%, 29% and 29%, respectively (any severity); and 14%, 13% and 13%, respectively (severe or worse). In adjusted analyses, depression risk was raised threefold in those reporting increased cancer‐related financial stress (odds ratio (OR) = 2.79, 95%CI 1.87–4.17) and increased cancer‐related financial strain (OR = 3.56, 95%CI 2.23–5.67). For severe or worse depression, the risk estimates were more pronounced (increased stress: OR = 4.36, 95%CI 2.35–8.10; increased strain: OR = 8.21, 95%CI 3.79–17.77). Similar associations were found for anxiety and distress.

Conclusions

Cancer‐related financial stress and strain were consistently associated with increased risk of adverse psychological outcomes. If confirmed, these findings provide further rationale for initiatives to alleviate the financial burden of cancer. Copyright © 2012 John Wiley & Sons, Ltd.
Comfort First: an evaluation of a procedural pain management programme for children with cancer
Authors: McCarthy Maria , Glick Ron , Green Jessica , Plummer Karin , Peters Kari , Johnsey Lydia , DeLuca Cinzia
Published: March 2012

Background

The Comfort First Program (CFP) provides children and their caregivers with early procedural pain management intervention to reduce procedural pain and distress. This study evaluated whether the CFP was meeting its goals and effectively implementing the Royal Australasian College of Physicians paediatric pain management guidelines.

Methods

The study was conducted as a single‐site cross‐sectional audit. One hundred and thirty‐five patients (mean age 7.7 years) receiving treatment at the Royal Children's Hospital, Melbourne, Children's Cancer Centre Day Oncology Unit were observed. Procedural aspects related to the treatment room, carer and staff behaviour, child distress and use of pharmacologic and nonpharmacologic interventions were recorded using an audit tool developed for the study.

Results

The procedure room was regularly quiet and prepared before the child entered. Median procedure duration was 8 min. Median procedure wait time was 54 min. At least one carer was typically present during procedures. Comfort First (CF) clinicians were more likely to be present in procedures with a significantly distressed child. Carers, nurses and CF clinicians generally displayed comfort‐promoting behaviour. Topical anaesthetic was regularly utilised. Nonpharmacologic supports were frequently used, particularly distraction. Patients under 8 years of age were significantly more likely to receive nonpharmacologic supports and have a carer and CF clinician present. Age was a significant predictor of distress, with higher distress rates in younger children.

Conclusions

The CFP was found to be effectively implementing procedural pain guidelines. Regular audit is recommended to ensure adherence to pain management standards. Copyright © 2012 John Wiley & Sons, Ltd.
Surgical management of pulmonary artery sling: Trachea diameter and outcomes with or without tracheoplasty
Authors: Huang Shu‐Chien , Wu En‐Ting , Wang Ching‐Chia , Chen Shyh‐Jye , Chen Yih‐Sharng , Chang Chung‐I , Chiu Ing‐Sh , Wang Shoei‐Shen
Published: March 2012

Objectives

Pulmonary artery sling is frequently associated with tracheal and/or bronchial stenosis. A number of patients receive only re‐implantation or relocation of the left pulmonary artery (LPA) while other patients may require tracheoplasty for stenosis of the airway. This study used computer tomography (CT) scans for the evaluation of airways and to evaluate the trachea diameter and the clinical outcomes with or without tracheoplasty.

Methods

A total of 15 patients with PA sling who received CT scans were included in this study. We reviewed the clinical outcomes and the severity of trachea stenosis, and evaluated various surgical strategies.

Results

Among the 15 patients, one received only conservative treatment, 14 (93%) patients received LPA re‐implantation, and eight (53%) received tracheoplasty. For the eight patients that received LPA reimplantation and tracheoplasty, five received slide tracheoplasty and all survived, two patients had pericardial patch augmentation and both died, and one patient received a resection and end‐to‐end anastomosis and survived. The diameter of the trachea in survivors without tracheoplasty was significantly larger than those who died or received tracheoplasty (3.2 ± 0.3 mm vs. 2.2 ± 0.4 mm, P = 0.003). Establishing 3.0 mm as the threshold, the positive predictive value for tracheoplasty or mortality was 89% and the negative predictive value was 83%.

Conclusions

In this study cohort, approximately 60% of the patients with PA sling received tracheoplasty. A diameter of the trachea <3 mm is associated with the use of tracheoplasty or poor outcomes. Slide tracheoplasty provided acceptable good results. Pediatr Pulmonol. 2012. 47:903–908. © 2012 Wiley Periodicals, Inc.
Mathieu Moonshine and symmetries of K3 σ‐models
Authors: Volpato R.
Published: March 2012

A recent observation by Eguchi, Ooguri and Tachikawa (EOT) suggests a relationship between the largest Mathieu group 𝕄24 and the elliptic genus of K3. This correspondence would be naturally explained by the existence of a non‐linear σ‐model on K3 with the Mathieu group as its group of symmetries. However, all possible symmetry groups of K3 models have been recently classified and none of them contains 𝕄24. We review the evidence in favour of the EOT conjecture and discuss the open problems in its physical interpretation.
Asymptotically Schrödinger space‐times
Authors: Hartong J. , Rollier B.
Published: March 2012

We first review how asymptotically Schrödinger space‐times arise in a natural way by performing a TsT transformation on asymptotically AdS space‐times and some of its consequences. We then give a coordinate independent definition of a pure Schrödinger space‐time in terms of an AdS metric and an AdS null Killing vector. Furthermore, by analogy with the AdS case, we provide a local coordinate independent definition of a Schrödinger boundary in terms of a defining function. Finally this directly leads us to the construction of a Fefferman‐Graham expansion for locally Schrödinger space‐times.
The manageable formation of the gradient‐layered polymer/fullerene blend films via the addition of bathocuproine and their applications in organic solar cells
Authors: Qin Dashan , Quan Wei , Liu Jinsuo , Li Guifang , Chen Lei , Zhang Jidong , Yan Donghang
Published: March 2012

We report the manageable formation of the gradient‐layered poly(3‐hexylthiophene) and [6,6]‐phenyl C61‐butyric acid methyl ester (P3HT/PCBM) blend film by spin coating via introducing bathocuproine (BCP) into the mixed P3HT/PCBM solution. The BCP can improve the aggregation and thereby the preferential precipitation of PCBM during the spin‐coating process, leading to the gradient‐layered phase separation of P3HT and PCBM. The regular solar cells using the gradient‐layered ternary blend films gave poor photovoltaic performance, due to the mismatch between the polarity of the regular‐device structure and the vertical composition profile of the ternary blend film. By contrast, in the inverted solar cell, the gradient‐layered ternary blend film could provide the increased device performance over the conventional bulk heterojunction binary blend films.
Rich variety in the ground states of [Pd(dmit)2]2 salts, and the methodology for analysing intra‐dimer interactions, inter‐dimer interactions and MO levels
Authors: Yamamoto Takashi , Nakazawa Yasuhiro , Tamura Masafumi , Yakushi Kyuya , Kato Reizo
Published: March 2012

A group of [Pd(dmit)2]2 salts, whose two‐dimensional structures take (pesudo‐) triangular lattice, has a diversity in the ground states. In order to investigate the ground states, we have developed the methodology for analysing subtle changes in the inter‐molecular interactions and MO level using the vibrational and electronic spectroscopy. This methodology is applied to several [Pd(dmit)2]2 salts. We have found some relationships between the ground states and the inter‐dimer and intra‐dimer interactions under HOMO–LUMO inversion.
Is there a common theme behind the correlated‐electron superconductivity in organic charge‐transfer solids, cobaltates, spinels, and fullerides?
Authors: Mazumdar Sumit , Clay R. Torsten
Published: March 2012

We posit that there exist deep and fundamental relationships between the above seemingly very different materials. The carrier concentration‐dependences of the electronic behavior in the conducting organic charge‐transfer solids and layered cobaltates are very similar. These dependences can be explained within a single theoretical model, the extended Hubbard Hamiltonian with significant nearest neighbor Coulomb repulsion. Interestingly, superconductivity in the cobaltates seems to be restricted to bandfilling exactly or close to one‐quarter, as in the organics. We show that dynamic Jahn–Teller effects and the resultant orbital ordering can lead to 1/4‐filled band descriptions for both superconducting spinels and fullerides, which show evidence for both strong electron–electron and electron–phonon interactions. The orbital orderings in antiferromagnetic lattice‐expanded bcc M3C60 and the superconductor are different in our model. Strong correlations, quarter‐filled band and lattice frustration are the common characteristics shared by these unusual superconductors.
Magnetic fluctuations above the Néel temperature in κ‐(BEDT‐TTF)2Cu[N(CN)2]Cl, a quasi‐2D Heisenberg antiferromagnet with Dzyaloshinskii–Moriya interaction
Authors: Antal Ágnes , Fehér Titusz , Náfrádi Bálint , Forró László , Jánossy András
Published: March 2012

We report on magnetic fluctuations studied by electron spin resonance (ESR) spectroscopy in the layered organic crystal κ‐(BEDT‐TTF)2Cu[N(CN)2]Cl. A line broadening above the antiferromagnetic ordering temperature, TN = 23 K is attributed to two‐dimensional magnetic fluctuations of a staggered magnetization induced by the interplay of the magnetic field and the Dzyaloshinskii–Moriya (DM) interaction.
Propensity score applied to survival data analysis through proportional hazards models: a Monte Carlo study
Authors: Gayat Etienne , Resche‐Rigon Matthieu , Mary Jean‐Yves , Porcher Raphaël
Published: March 2012

Propensity score methods are increasingly used in medical literature to estimate treatment effect using data from observational studies. Despite many papers on propensity score analysis, few have focused on the analysis of survival data. Even within the framework of the popular proportional hazard model, the choice among marginal, stratified or adjusted models remains unclear. A Monte Carlo simulation study was used to compare the performance of several survival models to estimate both marginal and conditional treatment effects. The impact of accounting or not for pairing when analysing propensity‐score‐matched survival data was assessed. In addition, the influence of unmeasured confounders was investigated. After matching on the propensity score, both marginal and conditional treatment effects could be reliably estimated. Ignoring the paired structure of the data led to an increased test size due to an overestimated variance of the treatment effect. Among the various survival models considered, stratified models systematically showed poorer performance. Omitting a covariate in the propensity score model led to a biased estimation of treatment effect, but replacement of the unmeasured confounder by a correlated one allowed a marked decrease in this bias. Our study showed that propensity scores applied to survival data can lead to unbiased estimation of both marginal and conditional treatment effect, when marginal and adjusted Cox models are used. In all cases, it is necessary to account for pairing when analysing propensity‐score‐matched data, using a robust estimator of the variance. Copyright © 2012 John Wiley & Sons, Ltd.
Adaptive designs for single‐arm phase II trials in oncology
Authors: Englert Stefan , Kieser Meinhard
Published: March 2012

Clinical phase II trials in oncology are conducted to determine whether the activity of a new anticancer treatment is promising enough to merit further investigation. Two‐stage designs are commonly used for this situation to allow for early termination. Designs proposed in the literature so far have the common drawback that the sample sizes for the two stages have to be specified in the protocol and have to be adhered to strictly during the course of the trial. As a consequence, designs that allow a higher extent of flexibility are desirable. In this article, we propose a new adaptive method that allows an arbitrary modification of the sample size of the second stage using the results of the interim analysis or external information while controlling the type I error rate. If the sample size is not changed during the trial, the proposed design shows very similar characteristics to the optimal two‐stage design proposed by Chang et al. (Biometrics 1987; 43:865–874). However, the new design allows the use of mid‐course information for the planning of the second stage, thus meeting practical requirements when performing clinical phase II trials in oncology. Copyright © 2012 John Wiley & Sons, Ltd.