bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of the orientation‐controlled damping temperature based on selective distribution of oligo‐phenol in acrylate rubber/chlorinated butyl rubber blends
Authors: Su Chang , He Pan , Yan Rongjun , Zhao Cunbin , Zhang Cheng
Published: April 2012

In this paper, a series of composites containing of the oligo‐phenol (produced by reacting of 4‐methyl‐phenol with dicyclopentadiene and isobutylene (MPDI)) as organic fillers, and chlorinated butyl rubber (CIIR)/acrylate rubber (AR) as matrix were prepared by melting blending method. The selective distribution phenomenon of organic fillers in the matrix and the damping properties of AR/CIIR/MPDI composites were characterized by DMA, DSC, FT‐IR and SEM, respectively. The results showed that MPDI could form hydrogen bond with AR more easily than with CIIR, which resulted in MPDI dispersing preferentially in AR phase in CIIR/AR composites. And the selective dispersion of MPDI caused that the damping temperature range was orientedly broadened towards the high temperature. Specially, with the content of MPDI increased to 10 wt% in AR/CIIR marix, only the Tg of AR in AR/CIIR composites shifted to higher temperature, which reached to 55.2°C, while the Tg and Tll of CIIR in AR/CIIR composites kept almost unchanged. Otherwise, the temperature range of AR/CIIR/MPDI was expanded to 100.2°C with the tan δ > 0.3. Therefore, it was expected as a promising way to orientedly broaden damping temperature range according to the selective distribution of organic additives in binary systems. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Utilization of antidepressants in Taiwan: a nationwide population‐based survey from 2000 to 2009
Authors: Wu Chi‐Shin , Shau Wen‐Yi , Chan Hung‐Yu , Lee Yen‐Chieh , Lai Yun‐Ju , Lai Mei‐Shu
Published: April 2012

Objective

This study examined trends in antidepressant utilization in Taiwan between 2000 and 2009.

Methods

We collected data from the National Health Insurance Research Database of all incident antidepressant use. We described the incidence, prevalence, and therapeutic indications of antidepressant use. We tested the trends by using logistic regression analyses with adjustment for age and sex.

Results

Overall, the prevalence of antidepressant use per 1000 persons increased from 32.1 in 2000 to 46.3 in 2009; however, the incidence per 1000 persons declined from 20.8 in 2000 to 16.5 in 2009. For antidepressant classes, the prescriptions of selective serotonin reuptake inhibitors and other new agents increased during the study periods; however, the use of tricyclic antidepressants, trazodone, and monoamine oxidase inhibitors declined. For therapeutic indications, we found increasing trends of antidepressant use for sleep and adjustment disorders; however, the rates of antidepressant use for mood disorder, anxiety disorders, and non‐psychiatric conditions decreased.

Conclusions

Regarding the new use of antidepressants in Taiwan between 2000 and 2009, we found that the decreased incidence of antidepressant use might be attributed mainly to the decreased use of tricyclic antidepressants and monoamine oxidase inhibitors. Decreased use among middle‐aged and older persons and fewer antidepressant prescriptions for non‐psychiatric conditions were also noted. Copyright © 2012 John Wiley & Sons, Ltd.
Optimal design of ultra‐broadband, omnidirectional, and polarization‐insensitive amorphous silicon solar cells with a core‐shell nanograting structure
Authors: Yang L. , Mo L. , Okuno Y. , He S.
Published: April 2012

We systematically investigated the optical behaviors of an amorphous silicon solar cell with a core‐shell nanograting structure. The horizontally propagating Bloch waves and Surface Plasmon Polariton waves lead to significant absorption enhancements and consequently short‐circuit current enhancements of this structure, compared with the conventional planar one. The perpendicular carrier collection makes this structure optically thick and electronically thin. An optimal design is achieved through full‐field numerical simulation, and a physical explanation is given. Our numerical results show that this configuration has ultra‐broadband, omnidirectional, and polarization‐insensitive responses and has a great potential in photovoltaics. Copyright © 2012 John Wiley & Sons, Ltd.
Regioregularity and solar cell device performance of poly(3‐dodecylthienylenevinylene)
Authors: Sun Jianyuan , Zhang Cheng , Venkatesan Swaminathan , Li Rui , Sun Sam‐Shajing , Qiao Qiquan
Published: April 2012

Influence of side chain regioregularity on photovoltaic performance has been investigated in bulk heterojunction solar cells based on a series of poly(3‐dodecylthienylenevinylene)s (C12‐PTV) and 6,6‐phenyl‐C61‐butyric acid methyl ester (PCBM). Performance of each C12‐PTV is optimized for fair comparison. It is found that regiorandomness has no detrimental effect on device performance, in sharp contrast to poly(3‐hexylthiophene) (P3HT). Fully regioregular C12‐PTV performs slightly poorer than less regioregular ones mainly due to its fast crystallization behavior. The results suggest that introduction of side chain regiorandomness is an effective strategy to enhance processability of certain types of polymers without a reduction in photovoltaic performance. The better polymer:PCBM weight ratio, found to be 3:7 for all C12‐PTVs, and improved device performance, as compared with the literature work on the same polymer synthesized by a different method, demonstrate again the importance of the integrity of polymer main chain structure. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012
Long‐term recovery of irradiated prostate cancer increases cancer stem cells
Authors: Cho Yong Mee , Kim Young Seok , Kang Mun Jung , Farrar William L. , Hurt Elaine M.
Published: April 2012

BACKGROUND

Despite improvements in treatment, prostate cancer (PC) remains the second‐leading cause of cancer death in men. Radiotherapy is among the first‐line treatments for PC, but a significant number of patients relapse. Recent evidence supports the idea that PC is initiated by a subset of cells, termed cancer stem cells (CSCs). CSCs have also been implicated in radioresistance in various malignancies, but their role in PC has not yet been investigated.

METHODS

We compared the relative radiosensitivity of isolated CSCs to the total population of their corresponding cell lines, and examined the relative numbers of CSCs in irradiated cell lines following long‐term recovery and in recurrent human PC.

RESULTS

Here, we show that while irradiation does not immediately favor increased survival of CSCs, irradiated PC cell lines showed an increase in CSC properties with long‐term recovery. These data suggest that, although CSCs are initially damaged by radiation, they possess a greater capacity for recovery and regrowth.

CONCLUSIONS

The combination of radiotherapy with a CSC‐targeted therapeutic strategy may prevent tumor recurrence. Prostate 72:1746–1756, 2012. © 2012 Wiley Periodicals, Inc.
Prevention of Hydrogen Peroxide‐Induced Red Blood Cells Lysis by Ilex paraguariensis Aqueous Extract: Participation of Phenolic and Xanthine Compounds
Authors: Peralta Ignacio N. , Cogoi Laura , Filip Rosana , Anesini Claudia
Published: April 2012

The fresh leaves and stems of Ilex paraguariensis (Aquifoliaceae) are employed to prepare the commercial product used in North‐eastern Argentina, Southern Brazil and Eastern Paraguay named yerba maté. The presence of polyphenols and xanthines, which present antioxidant activity, has been described in I. paraguariensis. In living organism, reactive oxygen species can cause tissue damage affecting erythrocyte membranes leading to hemolysis.

The aim of this work was to evaluate the protective effect of an aqueous extract of I. paraguariensis (green leaves) on the hemolysis of red blood cells induced by hydrogen peroxide and to correlate this activity with the enzymatic activity related to hydrogen peroxide metabolism. The antioxidant activity of chlorogenic acid and caffeine was also analysed to evaluate their contribution to the activity of the crude extract. The extract as well as the isolated compounds protected red blood cells from hemolysis. This effect was related to a catalase‐like activity. This study could contribute to the knowledge of the antioxidant activity of I. paraguariensis in view of the great quantities of yerba maté consumed by the population. Copyright © 2012 John Wiley & Sons, Ltd.
Chamomile Confers Protection against Hydrogen Peroxide‐Induced Toxicity through Activation of Nrf2‐Mediated Defense Response
Authors: Bhaskaran Natarajan , Srivastava Janmejai K. , Shukla Sanjeev , Gupta Sanjay
Published: April 2012

Oxidative stress plays an important role in the development of various human diseases. Aqueous chamomile extract is used as herbal medicine, in the form of tea, demonstrated to possess antiinflammatory and antioxidant properties. We demonstrate the cytoprotective effects of chamomile on hydrogen peroxide (H2O2)‐induced cellular damage in macrophage RAW 264.7 cells. Pretreatment of cells with chamomile markedly attenuated H2O2‐induced cell viability loss in a dose‐dependent manner. The mechanisms by which chamomile‐protected macrophages from oxidative stress was through the induction of several antioxidant enzymes including NAD(P)H:quinone oxidoreductase, superoxide dismutase, and catalase and increase nuclear accumulation of the transcription factor Nrf2 and its binding to antioxidant response elements. Furthermore, chamomile dose‐dependently reduced H2O2‐mediated increase in the intracellular levels of reactive oxygen species. Our results, for the first time, demonstrate that chamomile has protective effects against oxidative stress and might be beneficial to provide defense against cellular damage. Copyright © 2012 John Wiley & Sons, Ltd.
Anti‐Hyperglycemic Effect of Fermented Ginseng in Type 2 Diabetes Mellitus Mouse Model
Authors: Jeon Woo Jin , Oh Jin Sun , Park Myeong Soo , Ji Geun Eog
Published: April 2012

Ginseng has shown an efficacy in preventing and managing various health conditions. This study aimed to evaluate the effect of the fermented ginseng extract (FGE) in type 2 diabetes mellitus murine model. FGE was provided to male C57BL/ksJ‐db/db mice for 8 weeks at 0.1% (w/w) dose in contrast to water for the control group. Potential anti‐diabetic mechanisms were investigated with blood glucose, serum insulin, serum adiponectin, hemoglobin A1c (HbA1c), glucose tolerance, insulin secretion assay, quantitative real‐time polymerase chain reaction, and hematoxylin–eosin staining. Compared with the control group, the FGE group had lower levels of blood glucose after 6 and 9 h fasting, HbA1c, and the area under the curve in an oral glucose tolerance test and higher levels of adiponectin and serum insulin (p < 0.05). The FGE group had higher levels of peroxisome proliferator‐activated receptor gamma 2 and glucose transporter protein 2 mRNAs, a lower level of tumor necrosis factor‐α (TNF‐α) (p < 0.05), and less lymphocytes in pancreas than the control group had. The FGE exerted anti‐diabetic effects in type 2 diabetic mice. Copyright © 2012 John Wiley & Sons, Ltd.
Use of procaine and procainamide as derivatizing co‐matrices for the analysis of oligosaccharides by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Lavanant Hélène , Loutelier‐Bourhis Corinne
Published: April 2012

RATIONALE

Analysis of oligosaccharides by matrix‐assisted laser desorption/ionization (MALDI) mass spectrometry often yields only alkali metal cation adducts, which results in lower fragmentation yields and difficulty to retrieve sequence information. Derivatization by reductive amination may be used to promote Y‐type glycosidic cleavages. However, this involves time‐consuming preparations and purifications with sample loss. Here, procaine and procainamide were used directly as co‐matrices with 2,5‐dihydroxybenzoic acid (DHB).

METHODS

Acidified 10 g/L procaine hydrochloride or procainamide hydrochloride solutions in water/acetonitrile were added to the oligosaccharide solution one minute before preparing our MALDI targets using DHB with the dried‐droplet method. This simple protocol resulted in deposits of very fine homogeneous crystals.

RESULTS

Positive ion mass spectra, easily acquired in an automated mode, presented a high percentage of oligosaccharides derivatized as Schiff base or glycosylamine notably detected as protonated molecules [M + H]+. The high abundance of procaine or procainamide on the target did not impede the ionization process, improved the signal‐to‐noise ratio and eliminated the need to search for 'sweet spots'. Fragmentation of the protonated precursor ions of the derivatives largely favored Y‐type glycosidic cleavages.

CONCLUSIONS

This easy and fast sample preparation, involving low toxicity and easily accessible chemicals, allowed the selection of protonated molecules as precursor ions for post‐source decay analyses. This opened the possibility of simplifying sequence retrieval in routine oligosaccharide analyses. Copyright © 2012 John Wiley & Sons, Ltd.
Identification of n‐hydroxy acid metabolites in electron impact ionization mass spectrometry
Authors: Li Qingling , Zhang Guo‐Fang
Published: April 2012

RATIONALE

The catabolism of 4‐hydroxy acid (drugs of abuse and lipid peroxidation products) generates a series of hydroxy acids with different carbon chain lengths and hydroxyl group at different locations. The identification of these hydroxy acid metabolites is important to uncover the catabolic pathways of drugs of abuse and lipid peroxidation products.

METHODS

We characterized the fragmentation of trimethylsilyl (TMS) derivatives of hydroxy acids by electron impact ionization (EI) mass spectrometry (MS) with the aid of an isotope‐labeled compound. The metabolites (hydroxy acids) of 4‐hydroxy acid in isolated rat livers were identified by their characterized fragmentation patterns in gas chromatography (GC)/EI‐MS.

RESULTS

TMS migration to both ester and ether groups was found in the fragmentation of 2‐hydroxy acid‐ and 3‐hydroxy acid‐TMS derivatives, but only migration to the ester group was observed in the fragmentation of n‐hydroxy acid‐TMS (n ≥4) derivatives. TMS migration to the ester group generates the following fragments from different hydroxy acids: (i) the characteristic fragment at m/z 190 from 2‐hydroxy acid; (ii) the fragment at m/z 204 from both 3‐hydroxy acid and 4‐hydroxy acid; and (iii) a characteristic fragment at m/z 218 from 4‐hydroxy acid containing more than four carbons in the carbon skeleton. TMS migration to the ether group in 2‐hydroxy acid and 3‐hydroxy acid yields variant fragments depending on the carbon skeleton length. The identified metabolites of 4‐hydroxy acid confirmed the catabolic pathways of 4‐hydroxy acid in the isolated rat livers.

CONCLUSIONS

With the characterized fragmentation patterns of each hydroxy acid in EI‐MS, we successfully identified the various hydroxy acid metabolites of 4‐hydroxyoctanoic acid (and other 4‐hydroxy acids from C5 to C11) in the rat livers. Copyright © 2012 John Wiley & Sons, Ltd.
A statistical approach to delta layer depth profiling
Authors: Wucher Andreas , Krantzman Kristin D.
Published: April 2012

We present a simple statistical model describing the removal and relocation of material during a sputter depth profiling experiment. All input parameters are determined from low‐fluence molecular dynamics simulations, making the model de facto parameter free. The model can be used to extrapolate data from the molecular dynamics simulations to projectile fluences relevant to sputter depth profiling experiments. As a result, the erosion of the surface is calculated in terms of fluence‐dependent filling factors of different sample layers. Using input data determined for the 20‐keV C60 cluster bombardment of silicon, it is found that a steady‐state erosion profile is reached after removal of approximately 20 monolayer equivalents of material. Plotting the contribution of particles from a specific layer to the instantaneous sputtered flux, one can directly determine the delta layer response function predicted from such a model. It is shown that this function can be parameterized by the semiempirical Dowsett response function, and the resulting fitting parameters are compared with published depth profile data. The model is then used to study the role of different processes influencing the observed depth resolution. We find that the statistical nature of the sputtering process suffices to explain many features of experimentally measured delta layer depth profiles. Copyright © 2012 John Wiley & Sons, Ltd.
Compositional gradients and impurity distributions in CuInSe2 thin‐film solar cells studied by atom probe tomography
Authors: Choi Pyuck‐Pa , Cojocaru‐Mirédin Oana , Wuerz Roland
Published: April 2012

The present study is about the characterization of CuInSe2 thin‐film solar cells using atom probe tomography. Elemental distributions, in particular compositional gradients and impurity segregation at internal interfaces, have been determined at the sub‐nanometer scale. Direct evidence of impurity (Cd, Na, and O) segregation at CuInSe2 grain boundaries is given. Possibly occurring point defects are discussed with respect to their influence on the electronic properties and the efficiency of the solar cells. Copyright © 2012 John Wiley & Sons, Ltd.
Adhesion, atomic structure, and bonding variation at TiN/VN interface by chemical segregation
Authors: Yin Deqiang , Peng Xianghe , Qin Yi , Wang Zhongchang
Published: April 2012

Introduction of alloying elements often alters properties of materials. In the technologically significant multilayered superlattice coatings, interfaces are known to play a key role in the deformation mechanisms, especially in the phenomenon of interface‐induced superhardness at nanoscale. Here, we elucidate, by first‐principles calculations, atomic structure of TiN/VN interface and its relationship to adhesion upon introducing Cr, Mo, Ta, Y, Al, Nb, Zr, and Sc, the very commonly occurring alloying elements in the coating. We find that the elements Cr, Mo, Ta, Y weaken substantially interfacial adhesion, whereas the others modify adhesion only slightly. The bond length, charge transfer, and interactions between atoms at interface are found to be the key factors to understanding the origin of shift in properties in the coatings with the chemical alloying. Using several methods of analysis, we have clarified electronic mechanism behind the variation induced by alloying elements and determined the interfacial bonding nature to be mainly ionic with a certain degree of covalency. The theoretical calculations presented provide insight into the complex electronic properties of the TiN/VN interfaces with alloying elements. Our findings help enhance performances of the multilayered coatings for wide‐ranging applications. Copyright © 2012 John Wiley & Sons, Ltd.
Non‐contact evaluation of the electrical conductivity of thin metallic films by eddy current microscopy
Authors: Tohmyoh Hironori , Ishikawa Shoho , Muraoka Mikio
Published: April 2012

An eddy current microscopy technique to evaluate the electrical conductivity of thin metallic films in a non‐contact manner is reported. A narrow track formed in an approximately 100 nm thick Au film was prepared, and a Co–Cr coated magnetic tip was driven to oscillate above the track both with and without current passing through the track. Despite the absence of current, the electromagnetic interaction between the tip and the stray magnetic field from the track gave rise to a phase delay in the probe. This was due to an eddy current being induced within part of the track. Moreover, measurements of the phase change in the probe oscillation for different metallic films with thicknesses of about 100 nm found this to be proportional to the electrical conductivity of the film. Finally, the electrical conductivity of an Al film was evaluated using the eddy current microscopy technique. Copyright © 2012 John Wiley & Sons, Ltd.
Small biparietal diameter in fetuses with spina bifida on 11–13‐week and mid‐gestation ultrasound
Authors: Karl K. , Benoit B. , Entezami M. , Heling K. S. , Chaoui R.
Published: April 2012

Objectives

To assess whether, at 11–13‐week and mid‐trimester ultrasound examinations, the biparietal diameter (BPD) in fetuses with open spina bifida is smaller than the reference range.

Methods

In a multicenter retrospective analysis of data from 23 fetuses with open spina bifida diagnosed at 16–24 weeks, BPD at diagnosis was compared with that measured at 11–13 weeks, before diagnosis. Z‐scores were calculated for comparison of BPD deviations from the reference range within the groups at 11–13 weeks and 16–24 weeks, and between these two time intervals.

Results

BPD Z‐scores at 11–13 weeks and 16–24 weeks were significantly lower (P < 0.0001) in fetuses with open spina bifida when compared to the reference range, with mean values of − 1.29 and − 2.14, respectively, corresponding to the 10th and 1.5th centiles, respectively. At 11–13 weeks only six of the 23 (26%) fetuses with open spina bifida had BPD below the 5th centile, in comparison to 16 (69%) at mid‐gestation. This was confirmed by paired t‐test comparing the first‐trimester with the second‐trimester BPD measurements, which showed significantly slower growth of the BPD in fetuses with spina bifida.

Conclusion

In fetuses with open spina bifida, BPD is smaller not only in the second trimester, as previously reported, but also in the first trimester. This is most likely due to loss of cerebrospinal fluid. We suggest that a BPD value < 10th centile in an otherwise normally grown fetus at 11–13 weeks' gestation should be considered as a potential subtle early marker for open spina bifida. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
Worsening Central Sarcopenia and Increasing Intra‐Abdominal Fat Correlate with Decreased Survival in Patients with Adrenocortical Carcinoma
Authors: Miller Barbra S. , Ignatoski Kathleen M. , Daignault Stephanie , Lindland Ceit , Doherty Megan , Gauger Paul G. , Hammer Gary D. , Wang Stewart C. , Doherty Gerard M. ,   The University of Michigan Analytical Morphomics Group
Published: April 2012

Background

Accurate prediction of survival from adrenocortical carcinoma (ACC) is difficult and current staging models are unreliable. Central sarcopenia as part of the cachexia syndrome is a marker of frailty and predicts mortality. This study seeks to confirm that psoas muscle density (PMD), lean psoas muscle area (LPMA), lumbar skeletal muscle index (LSMI), and intra‐abdominal (IA) or subcutaneous fat (SC) can be used in combination to more accurately predict survival in ACC patients.

Methods

PMD, LPMA, IA, and SC fat were measured on serial CT scans of patients with ACC. Clinical outcome was correlated with quantitative data from patients with ACC and analyzed. A linear regression model was used to describe the relationship between PMD, LPMA, LSMI, IA, and SC fat, time to recurrence, and length of survival according to tumor stage.

Results

One hundred twenty‐five ACC patients (94 females) were treated from 2005 to 2011. Significant morphometric predictors of survival include PMD, LPMA, and IA fat (p ≤ 0.0001, ≤0.0024, <0.0001, respectively) and improve prediction of survival compared to using stage alone. A 100‐mm2 increase in LPMA confers an 8 % lower hazard of death. LSMI does not change significantly between stages (p = 0.3196).

Conclusion

Decreased PMD, LPMA, and increased IA fat suggest decreased survival in ACC patients and correlate with traditional staging systems. A more precise prediction of survival may be achieved when staging systems and morphometric measures are used in combination. Serial measurements of morphometric data are possible. The rate of change of these variables over time may be more important than the absolute value.
SOWING STRATEGIES FOR BARLEY (HORDEUM VULGARE L.) BASED ON MODELLED YIELD RESPONSE TO WATER WITH AQUACROP – CORRIGENDUM
Authors: ABRHA BERHANU , DELBECQUE NELE , RAES DIRK , TSEGAY ALEMTSEHAY , TODOROVIC MLADEN , HENG LEE , VANUTRECHT ELINE , GEERTS SAM , GARCIA-VILA MARGA , DECKERS SEPPE
Published: April 2012

In the published article Berhanu et al. (2012) one of the authors’ names was misspelled and should have read ElineVanuytrecht.
Financial Strength and Product Market Competition: Evidence from Asbestos Litigation
Authors: Hadlock Charles J. , Sonti Ramana
Published: April 2012

We study the role of financial strength on product market competition by examining exogenous shocks to a firm’s liability structure arising from asbestos litigation. We find that exogenous increases (decreases) in asbestos liabilities are interpreted by the market as negative (positive) news for a firm’s close competitors. These reactions are magnified in events in which one asbestos-tainted firm goes bankrupt and other asbestos-tainted stocks fall on the news of the bankruptcy. For smaller competitors, market reactions are more pronounced in more concentrated industries. Our findings support the general hypothesis that increases in fixed liabilities lead to more aggressive product market interactions.
DEBT DENOMINATION AND DEFAULT RISK IN EMERGING MARKETS
Authors: Gumus Inci
Published: April 2012

This paper develops a two-sector small open economy model to analyze the effects of the currency denomination of debt on default risk and interest rates in emerging market economies. Default risk is determined endogenously and depends on the incentives for repayment. The economy can borrow using tradable-denominated nonindexed bonds or bonds whose return is indexed to the domestic price index, which are used as proxies for foreign currency and domestic currency debt, respectively. The model predicts that foreign currency debt leads to lower default risk for high output levels and domestic currency debt reduces the default risk for low output levels. Although the effect of debt denomination on default risk changes with the output level, the default rate of the economy and average interest rates decline as domestic currency borrowing increases. In addition, domestic currency borrowing is found to reduce the countercyclicality of interest rates and the trade balance.
Review of Sociological Literature on Intercountry Adoption
Authors: Willing Indigo , Fronek Patricia , Cuthbert Denise
Published: April 2012

This review surveys sociological literature on intercountry adoption from 1997 to 2010. The analysis finds a preponderance of literature from the United States, reflecting its place as a major receiving country, and a focus on adoption experience organised by reference to the adoption triad: adoptive parents, adoptees, birth families. Reflecting the power imbalances in intercountry adoption, the voices and views of adoptive parents dominate the literature. There is an emerging literature generated by researchers who are intercountry adoptees, while birth families remain almost invisible in this literature. A further gap identified by this review is work which examines intercountry adoption as a global social practice and work which critically examines policy.
Case Study of a Patient with Acute on Chronic Pain Following Total Abdominal Hysterectomy
Authors: Dee Jonathan F.
Published: April 2012

The aim of this case study is to critically explore the holistic care of a patient who requires pain management in the Post Anaesthetic Care Unit (PACU). The development of chronic pain can have a significant psychological impact as well as a debilitating physical effect. The article examines pain assessment tools used in the PACU as well as barriers to their implementation. Finally, both pharmacological and non-pharmacological holistic care interventions are examined.
On the autonomous detection of coronal mass ejections in heliospheric imager data
Authors: Tappin S. J. , Howard T. A. , Hampson M. M. , Thompson R. N. , Burns C. E.
Published: April 2012

We report on the development of an Automatic Coronal Mass Ejection (CME) Detection tool (AICMED) for the Solar Mass Ejection Imager (SMEI). CMEs observed with heliospheric imagers are much more difficult to detect than those observed by coronagraphs as they have a lower contrast compared with the background light, have a larger range of intensity variation and are easily confused with other transient activity. CMEs appear in SMEI images as very faint often‐fragmented arcs amongst a much brighter and often variable background. AICMED operates along the same lines as Computer Aided CME Tracking (CACTus), using the Hough Transform on elongation‐time J‐maps to extract straight lines from the data set. We compare AICMED results with manually measured CMEs on almost three years of data from early in SMEI operations. AICMED identified 83 verifiable events. Of these 46 could be matched with manually identified events, the majority of the non‐detections can be explained. The remaining 37 AICMED events were newly discovered CMEs. The proportion of false identification was high, at 71% of the autonomously detected events. We find that AICMED is very effective as a region of interest highlighter, and is a promising first step in autonomous heliospheric imager CME detection, but the SMEI data are too noisy for the tool to be completely automated.
In situ cosmogenic radiocarbon production and 2‐D ice flow line modeling for an Antarctic blue ice area
Authors: Buizert Christo , Petrenko Vasilii V. , Kavanaugh Jeffrey L. , Cuffey Kurt M. , Lifton Nathaniel A. , Brook Edward J. , Severinghaus Jeffrey P.
Published: April 2012

Radiocarbon measurements at ice margin sites and blue ice areas can potentially be used for ice dating, ablation rate estimates and paleoclimatic reconstructions. Part of the measured signal comes from in situ cosmogenic 14C production in ice, and this component must be well understood before useful information can be extracted from 14C data. We combine cosmic ray scaling and production estimates with a two‐dimensional ice flow line model to study cosmogenic 14C production at Taylor Glacier, Antarctica. We find (1) that 14C production through thermal neutron capture by nitrogen in air bubbles is negligible; (2) that including ice flow patterns caused by basal topography can lead to a surface 14C activity that differs by up to 25% from the activity calculated using an ablation‐only approximation, which is used in all prior work; and (3) that at high ablation margin sites, solar modulation of the cosmic ray flux may change the strength of the dominant spallogenic production by up to 10%. As part of this effort we model two‐dimensional ice flow along the central flow line of Taylor Glacier. We present two methods for parameterizing vertical strain rates, and assess which method is more reliable for Taylor Glacier. Finally, we present a sensitivity study from which we conclude that uncertainties in published cosmogenic production rates are the largest source of potential error. The results presented here can inform ongoing and future 14C and ice flow studies at ice margin sites, including important paleoclimatic applications such as the reconstruction of paleoatmospheric 14C content of methane.
A conceptual model for the blooming behavior and persistence of the benthic mat‐forming diatomDidymosphenia geminata in oligotrophic streams
Authors: Cullis James D. S. , Gillis Carole‐Anne , Bothwell Max L. , Kilroy Cathy , Packman Aaron , Hassan Marwan
Published: April 2012

The benthic, mat‐forming diatomDidymosphenia geminata has the unique ability to produce large amounts of algal biomass under oligotrophic conditions in cold, fast flowing streams and rivers. This presents an ecological paradox that challenges our current understanding of stream ecosystem dynamics. Our understanding of the drivers of D. geminata ecology is still limited. Here we present a conceptual model for the blooming behavior and persistence of this species to advance scientific understanding of strategies for life in fast flowing oligotrophic waters and support the design of future research and mitigation measures for nuisance algal blooms. The conceptual model is based on a synthesis of data and ideas from a range of disciplines including hydrology, geomorphology, biogeochemistry, and ecology. The conceptual model highlights the role of water chemistry, river morphology, and flow thresholds in defining the habitat window for D. geminata. We propose that bed disturbance is a primary control on accumulation and persistence of D. geminataand that the removal threshold can be determined by synthesizing site‐specific information on hydrology and geomorphology. Further, we propose that a key to understanding the didymo paradox is the separation of cellular reproduction and mat morphology with specific controls acting in respect of the different processes.
Validation of atmospheric reanalyses over the central Arctic Ocean
Authors: Jakobson Erko , Vihma Timo , Palo Timo , Jakobson Liisi , Keernik Hannes , Jaagus Jaak
Published: April 2012

Atmospheric reanalyses were validated against tethersonde sounding data on air temperature, air humidity and wind speed, collected during the drifting ice station Tara in the central Arctic in April–August 2007. The data were not assimilated into the reanalyses, providing a rare possibility for their independent validation, which was here made for the lowermost 890 m layer. The following reanalyses were included in the study: the European ERA‐Interim, the Japanese JCDAS, and the U.S. NCEP‐CFSR, NCEP‐DOE, and NASA‐MERRA. All reanalyses included large errors. ERA‐Interim was ranked first; it outperformed the other reanalyses in the bias and root‐mean‐square‐error (RMSE) for air temperature as well as in the bias, RMSE, and correlation coefficient for the wind speed. ERA‐Interim suffered, however, from a warm bias of up to 2°C in the lowermost 400 m layer and a moist bias of 0.3 to 0.5 g kg−1throughout the 890 m layer. The NCEP‐CFSR, NCEP‐DOE, and NASA‐MERRA reanalyses outperformed the other reanalyses with respect to 2‐m air temperature and specific humidity and 10‐m wind speed, which makes them, especially NCEP‐CSFR, better in providing turbulent flux forcing for sea ice models. Considering the whole vertical profile, however, the older NCEP‐DOE got the second highest overall ranking, being better than the new NCEP‐CFSR. Considering the whole group of reanalyses, the largest air temperature errors surprisingly occurred during higher‐than‐average wind speeds. The observed biases in temperature, humidity, and wind speed were in many cases comparable or even larger than the climatological trends during the latest decades.
Bubble‐induced turbulence suppression in Langmuir circulation
Authors: Gemmrich Johannes
Published: April 2012

Dissipation rates ϵof turbulent kinetic energy and air bubble characteristics were observed within the wave‐enhanced near‐surface layer in the open ocean. During a period of well developed Langmuir circulation, short periods of increased air fraction and peak bubble radii <150μm at 2.5m, indicative of the instrumentation package drifting through convergence zones, coincide with significantly reduced dissipation rates. The rate of turbulence suppression correlates well with the buoyancy frequency inferred from the vertical gradient of air fraction. The Ozmidov scale and turbulent time scales associated with the bubble induced stratification are of O(0.5m) and O(20–60s), respectively. These stratification characteristics are consistent with the suppression of energy containing eddies close to the surface, which in turn results in reduced turbulent dissipation rates. Dissipation rates are observed to decay with depth following a power law ϵ ∝ zn, and n = −1, consistent with the theoretical value for constant stress layer scaling, is found within convergence zones, but n ≈ −3 outside.
The Angiogenic Inhibitor TNP‐470 Decreases Caloric Intake and Weight Gain in High‐Fat Fed Mice
Authors: White Heather M. , Acton Anthony J. , Considine Robert V.
Published: April 2012

The angiogenic inhibitor TNP‐470 attenuates high‐fat diet‐induced obesity; however, it is not clear how the compound alters energy balance to prevent weight gain. Five‐week‐old C57BL/6J mice were fed high‐fat diet (45% energy from fat) for 6.5 weeks and treated with TNP‐470 (20 mg/kg body weight; n = 7) or vehicle (saline; n = 7). Control mice (n = 8) received standard chow and sham injection. TNP‐470 mice initially gained weight, but by day 5 body weight was significantly less than high‐fat fed (HFF) mice and not different from that of chow‐fed mice, an effect maintained to the end of the study (28.6 ± 0.6 vs. 22.4 ± 0.6 and 22.2 ± 0.5 g). Percent body fat was reduced in TNP‐470 compared to HFF mice, but was greater than that of chow mice (34.0 ± 1.5, 23.9 ± 1.5, and 17.0 ± 1.4%, P < 0.05). Food intake in TNP‐470‐treated mice was less (P < 0.05) than that in HFF mice by day 5 of treatment (2.5 ± 0.1 vs. 2.8 ± 0.1 g/mouse/day) and remained so to the end of the study. Twenty‐four hours energy expenditure was greater (P < 0.05) in TNP‐470 than HFF or chow mice (7.05 ± 0.07 vs. 6.69 ± 0.08 vs. 6.79 ± 0.09 kcal/kg/h), an effect not explained by a difference in energy expended in locomotion. Despite normalization of body weight, TNP‐470 mice exhibited impaired glucose tolerance (area under the curve 30,556 ± 1,918 and 29,290 ± 1,584 vs. 24,421 ± 903 for TNP, HFF, and chow fed, P < 0.05). In summary, the angiogenic inhibitor TNP‐470 attenuates weight gain in HFF mice via a reduction in caloric intake and an increase in energy expenditure.
Indian Hedgehog signalling triggers Nkx3.2 protein degradation during chondrocyte maturation
Authors: Choi Seung-Won , Jeong Da-Un , Kim Jeong-Ah , Lee Boyoung , Joeng Kyu Sang , Long Fanxin , Kim Dae-Won
Published: April 2012

The Ihh (Indian Hedgehog) pathway plays an essential role in facilitating chondrocyte hypertrophy and bone formation during skeletal development. Nkx3.2 (NK3 homeobox 2) is initially induced in chondrocyte precursor cells, maintained in early-stage chondrocytes and down-regulated in terminal-stage chondrocytes. Consistent with these expression patterns, Nkx3.2 has been shown to enhance chondrocyte differentiation and cell survival, while inhibiting chondrocyte hypertrophy and apoptosis. Thus, in the present study, we investigated whether Nkx3.2, an early-stage chondrogenic factor, can be regulated by Ihh, a key regulator for chondrocyte hypertrophy. We show that Ihh signalling can induce proteasomal degradation of Nkx3.2. In addition, we found that Ihh can suppress levels of Lrp (low-density-lipoprotein-receptor-related protein) (Wnt co-receptor) and Sfrp (secreted frizzled-related protein) (Wnt antagonist) expression, which, in turn, may selectively enhance Lrp-independent non-canonical Wnt pathways in chondrocytes. In agreement with these findings, Ihh-induced Nkx3.2 degradation requires Wnt5a, which is capable of triggering Nkx3.2 degradation. Finally, we found that Nkx3.2 protein levels in chondrocytes are remarkably elevated in mice defective in Ihh signalling by deletion of either Ihh or smoothened. Thus these results suggest that Ihh/Wnt5a signalling may play a role in negative regulation of Nkx3.2 for appropriate progression of chondrocyte hypertrophy during chondrogenesis.
Pref-1 preferentially inhibits heat production in brown adipose tissue
Authors: Rakhshandehroo Maryam , Koppen Arjen , Kalkhoven Eric
Published: April 2012

In mammals there are two types of adipocytes with opposing functions. Brown adipocytes are characterized by a high number of mitochondria and are specialized for heat production (thermogenesis), expressing thermogenic genes such as UCP1 (uncoupling protein 1). White adipocytes, on the other hand, store energy. Although many key regulators in the differentiation of white adipocytes have been established, our current knowledge on the same proteins in brown adipogenesis is lagging behind. One example is Pref-1 (pre-adipocyte factor-1), which maintains white pre-adipocytes in an undifferentiated state, but is only poorly characterized in the brown pre-adipocyte lineage. In this issue of the Biochemical Journal, Armengol et al. now shed new light on the role and regulation of Pref-1 in brown pre-adipocytes. First, Pref-1 specifically inhibits the thermogenic gene programme in brown pre-adipocytes. Secondly, they identified the transcription factor C/EBPδ (CCAAT/enhancer-binding protein δ) as a direct positive regulator of Pref-1 expression, whereas this protein does not fulfil this role in white adipogenesis. Taken together, these findings indicate that specific manipulation of brown adipocyte differentiation and/or function without interfering with their white adipocyte counterparts may be possible, which may open up new therapeutic ways to combat obesity-associated health problems.
Cardiac sympathetic hyperinnervation in deoxycorticosterone acetate-salt hypertensive rats
Authors: Lee Tsung-Ming , Chen Chien-Chang , Chang Nen-Chung
Published: April 2012

Sympathetic activities are elevated in the central SNSs (sympathetic nervous systems) of hypertensive animals, but it is not known whether sympathetic innervation is also elevated in the heart. Sympathetic hyper-responsiveness in hypertension may result from oxidative stress. The aim of the present study was to investigate sympathetic hyperinnervation in DOCA (deoxycorticosterone acetate)-salt hypertensive rats with established hypertension. At 4 weeks after the start of DOCA-salt treatment and uninephrectomization, male Wistar rats were randomized into three groups for 8 weeks: vehicle, NAC (N-acetylcysteine) and triple therapy (hydralazine, hydrochlorothiazide and reserpine). DOCA-salt was associated with increased oxidant release. DOCA-salt produced concentric left ventricular hypertrophy and cardiomyocyte hypertrophy. Sympathetic hyperinnervation was observed in DOCA-salt rats, as assessed by myocardial noradrenaline levels, immunofluorescent analysis of tyrosine hydroxylase, growth-associated factor 43 and neurofilament and Western blotting and real-time quantitative RT–PCR (reverse transcription–PCR) of NGF (nerve growth factor). Arrhythmic scores during programmed stimulation in DOCA-salt rats were significantly higher than those in the control rats. Triple therapy, despite being effective on BP (blood pressure), offered neither attenuated cardiomyocyte hypertrophy nor anti-arrhythmia. The effects of DOCA-salt treatment on NGF expression, sympathetic hyperinnervation and arrhythmias were attenuated by NAC. Furthermore, the effects of NAC on NGF were abolished by administering BSO (L-buthionine sulfoximine), an inhibitor of glutamate–cysteine ligase. In conclusion, DOCA-salt treatment contributes to up-regulation of NGF proteins probably through a free radical-dependent pathway in a BP-independent manner. DOCA-salt rats treated with NAC attenuate sympathetic hyperinnervation and thus show a beneficial effect on arrhythmogenic response to programmed electrical stimulation.
Direct mapping of plasmonic coupling between a triangular gold island pair
Authors: Chen Weizhe , Kirilyuk Andrei , Kimel Alexey , Rasing Theo
Published: April 2012

Local plasmonic coupling between a triangular gold island pair is observed with high spatial resolution (∼10 nm) by an apertureless scanning near-field optical microscope. The measured local field distribution is fully reproduced by three dimensional numerical simulations. Our results show a strong near-field coupling between two adjacent gold triangles, which gives direct evidence to the local field enhancement in plasmonic nanoantenna effect.
Applying alpha-channeling to mirror machines
Authors: Zhmoginov A. I. , Fisch N. J.
Published: April 2012

The α-channeling effect entails the use of radio-frequency waves to expel and cool high-energetic α particles born in a fusion reactor; the device reactivity can then be increased even further by redirecting the extracted energy to fuel ions. Originally proposed for tokamaks, this technique has also been shown to benefit open-ended fusion devices. Here, the fundamental theory and practical aspects of α channeling in mirror machines are reviewed, including the influence of magnetic field inhomogeneity and the effect of a finite wave region on the α-channeling mechanism. For practical implementation of the α-channeling effect in mirror geometry, suitable contained weakly damped modes are identified. In addition, the parameter space of candidate waves for implementing the α-channeling effect can be significantly extended through the introduction of a suitable minority ion species that has the catalytic effect of moderating the transfer of power from the α-channeling wave to the fuel ions.
A study of the accuracy of moment-closure approximations for stochastic chemical kinetics
Authors: Grima Ramon
Published: April 2012

Moment-closure approximations have in recent years become a popular means to estimate the mean concentrations and the variances and covariances of the concentration fluctuations of species involved in stochastic chemical reactions, such as those inside cells. The typical assumption behind these methods is that all cumulants of the probability distribution function solution of the chemical master equation which are higher than a certain order are negligibly small and hence can be set to zero. These approximations are ad hoc and hence the reliability of the predictions of these class of methods is presently unclear. In this article, we study the accuracy of the two moment approximation (2MA) (third and higher order cumulants are zero) and of the three moment approximation (3MA) (fourth and higher order cumulants are zero) for chemical systems which are monostable and composed of unimolecular and bimolecular reactions. We use the system-size expansion, a systematic method of solving the chemical master equation for monostable reaction systems, to calculate in the limit of large reaction volumes, the first- and second-order corrections to the mean concentration prediction of the rate equations and the first-order correction to the variance and covariance predictions of the linear-noise approximation. We also compute these corrections using the 2MA and the 3MA. Comparison of the latter results with those of the system-size expansion shows that: (i) the 2MA accurately captures the first-order correction to the rate equations but its first-order correction to the linear-noise approximation exhibits the wrong dependence on the rate constants. (ii) the 3MA accurately captures the first- and second-order corrections to the rate equation predictions and the first-order correction to the linear-noise approximation. Hence while both the 2MA and the 3MA are more accurate than the rate equations, only the 3MA is more accurate than the linear-noise approximation across all of parameter space. The analytical results are numerically validated for dimerization and enzyme-catalyzed reactions.
The nature of the low energy band of the Fenna-Matthews-Olson complex: Vibronic signatures
Authors: Caycedo-Soler Felipe , Chin Alex W. , Almeida Javier , Huelga Susana F. , Plenio Martin B.
Published: April 2012

Based entirely upon actual experimental observations on electron-phonon coupling, we develop a theoretical framework to show that the lowest energy band of the Fenna-Matthews-Olson complex exhibits observable features due to the quantum nature of the vibrational manifolds present in its chromophores. The study of linear spectra provides us with the basis to understand the dynamical features arising from the vibronic structure in nonlinear spectra in a progressive fashion, starting from a microscopic model to finally performing an inhomogeneous average. We show that the discreteness of the vibronic structure can be witnessed by probing the diagonal peaks of the nonlinear spectra by means of a relative phase shift in the waiting time resolved signal. Moreover, we demonstrate that the photon-echo and non-rephasing paths are sensitive to different harmonics in the vibrational manifold when static disorder is taken into account. Supported by analytical and numerical calculations, we show that non-diagonal resonances in the 2D spectra in the waiting time, further capture the discreteness of vibrations through a modulation of the amplitude without any effect in the signal intrinsic frequency. This fact generates a signal that is highly sensitive to correlations in the static disorder of the excitonic energy albeit protected against dephasing due to inhomogeneities of the vibrational ensemble.