bluuebunny/crossref_metadata_2025 huggingface dataset:
Autonomic Arousal During Actigraphically Estimated Waking and Sleep in Male Veterans With PTSD
Authors: Bertram Franziska , Jamison Andrea L. , Slightam Cindie , Kim Sunyoung , Roth Heidi L. , Roth Walton T.
Published: October 2014

Physiological hyperarousal is manifested acutely by increased heart rate, decreased respiratory sinus arrhythmia, and increased skin conductance level and variability. Yet it is uncertain to what extent such activation occurs with the symptomatic hyperarousal of posttraumatic stress disorder (PTSD). We compared 56 male veterans with current PTSD to 54 males who never had PTSD. Subjects wore ambulatory devices that recorded electrocardiograms, finger skin conductance, and wrist movement while in their normal environments. Wrist movement was monitored to estimate sleep and waking periods. Heart rate, but not the other variables, was elevated in subjects with PTSD equally during waking and during actigraphic sleep (effect sizes, Cohen's d, ranged from 0.63 to 0.89). The length of the sleep periods and estimated sleep fragmentation did not differ between groups. Group heart rate differences could not be explained by differences in body activity, PTSD hyperarousal symptom scores, depression, physical fitness, or antidepressant use.
Self‐Monitoring of Reexperiencing Symptoms: A Randomized Trial
Authors: Brown Amanda Joelle , Bollini Annie M. , Craighead Linda W. , Astin Millie C. , Norrholm Seth Davin , Bradley Bekh
Published: October 2014

The efficacy of a brief intervention to self‐monitor reexperiencing symptoms was evaluated in 137 U.S. combat veterans with PTSD who were enrolled in 5‐week psychoeducation groups at a large Veterans Affairs Medical Center. Groups were randomized to psychoeducation alone (Education Control, n = 50) or psychoeducation plus intrusion monitoring (Education + Monitoring, n = 87). Education + Monitoring participants were asked to make a daily record of the number and content of nightmares, flashbacks, intrusive trauma‐related thoughts, and physiological and emotional reactions to triggers. Avoidance symptoms were reduced in both conditions (η2 = .093), with no additional benefit from intrusion monitoring (η2 = .001). Compliance with intrusion monitoring was markedly low, which complicated the interpretation of the study findings. Even though intrusion monitoring has a strong theoretical foundation and may be an efficient and cost‐effective alternative to more structured treatments for PTSD, the effect of intrusion monitoring will not be clearly understood until higher compliance can be achieved. Future work in this area should address barriers to compliance and investigate strategies for enhancing motivation to engage in self‐monitoring.
From Betrayal to the Bottle: Investigating Possible Pathways From Trauma to Problematic Substance Use
Authors: Delker Brianna C. , Freyd Jennifer J.
Published: October 2014

Research in both community and clinical settings has found that exposure to cumulative interpersonal trauma predicts substance use problems. Less is known about betrayal as a dimension of trauma exposure that predicts substance use, and about the behavioral and psychological pathways that explain the relation between trauma and substance use. In a sample of 362 young adults, this study evaluated three intervening pathways between betrayal trauma exposure prior to age 18 years and problematic substance use: (a) substance use to cope with negative affect, (b) difficulty discerning and/or heeding risk, and (c) self‐destructiveness. In addition, exposure to trauma low in betrayal (e.g., earthquake) was included in the model. Bootstrap tests of indirect effects revealed that betrayal trauma prior to age 18 years was associated with problematic substance use via posttraumatic stress and two intervening pathways: difficulty discerning/heeding risk (β = .07, p < .001), and self‐destructiveness (β = .12, p < .001). Exposure to lower betrayal trauma was not associated with posttraumatic stress or problematic substance use. Results contribute to a trauma‐informed understanding of substance use that persists despite potentially harmful consequences.
Facile Synthesis and Solid‐State Properties of Liquid‐Crystalline Polypeptides Bearing Biphenyl Mesogens and Alkyl Tails
Authors: Yuan Qiulin , Liu Dan , Deng Yong , Ling Ying , Tang Haoyu
Published: October 2014

A series of liquid‐crystalline 4‐alkyloxybiphenyl‐poly(γ‐propyl‐l‐glutamate) conjugates (PPLGn‐g‐BPCm, n = 10, 54, 110, and 274, m = 4, 6, and 12) with end‐on biphenyl mesogens and variable alkyl tails is synthesized via a facile copper‐mediated alkyne–azide [2+3] 1,3‐dipolar cycloaddition. 1H NMR and FTIR analyses reveal a quantitative conjugation efficiency for each sample. Variable‐temperature FTIR results indicate an irreversible α‐helical to β‐sheet transition of the PPLG10‐g‐BPC6 in the solid state, whereas PPLGn‐g‐BPCm samples with a longer main‐chain length (n ≥ 54) only adopt an α‐helical conformation in the temperature range between 25 and 200 °C. DSC, polarized optical microscopy (POM), and wide‐angle X‐ray scattering (WAXS) results collectively reveal that the PPLGn‐g‐BPCm samples undergo a reversible crystalline to liquid‐crystalline phase transition depending on the main‐/side‐chain lengths. The PPLGn‐g‐BPCm (n ≥ 54, m ≤ 6) samples form highly stable smectic (SmC or SmE) phases with a calculated tilt angle of 73–90°.

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Synthesis of High‐Molecular‐Weight Brush Polymers via RAFT Polymerization within the Micellar Nanoreactor of a PEG‐Based Macromonomer
Authors: Li Na , Liu Weiwei , Xu Lijian , Xu Jianxiong , Du Jingjing
Published: October 2014

The RAFT polymerization of an amphipathic PEG‐based macromonomer (mPEG‐g‐S) in water is performed. It is found that the polymerization proceeds via a micellar polymerization process. The polymerization kinetics, polymer chain extension, and polymer particle evolution of RAFT micellar polymerization are evaluated. It is demonstrated that the polymerization possesses a fast rate and high monomer conversion due to locally concentrating and orienting the hydrophobic polymerizing groups within the micellar nanoreactor. Moreover, the RAFT micellar polymerization is under good control since the polydispersity index (PDI) value of the synthesized brush copolymer is below 1.3 in most cases, even under polymerization conditions with the ratio of RAFT agent to macromonomer at 1:400. Polymerization leads to the formation of a completely grafted brush copolymer, and the as‐synthesized brush copolymer will self‐assemble into spherical particles during the polymerization process. This strategy is anticipated to be an efficient way for the controlled synthesis of completely grafted brush polymers with high molecular weights and their corresponding self‐assembled particles.

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Enhancement of Anhydrous Proton Conductivity of Poly(vinylphosphonic acid)–Poly(2,5‐benzimidazole) Membranes via In Situ Polymerization
Authors: Sen Unal , Usta Hakan , Acar Oktay , Citir Murat , Canlier Ali , Bozkurt Ayhan , Ata Ali
Published: October 2014

Polymer electrolyte membranes (PEMs) are synthesized via in situ polymerization of vinylphosphonic acid (VPA) within a poly(2,5‐benzimidazole) (ABPBI) matrix. The characterization of the membranes is carried out by using Fourier transform infrared (FTIR) spectroscopy for the interpolymer interactions, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) for the thermal properties, and scanning electron microscopy (SEM) for the morphological properties. The physicochemical characterizations suggest the complexation between ABPBI and PVPA and the formation of homogeneous polymer blends. Proton conductivities in the anhydrous state (150 °C) measured by using impedance spectroscopy are considerable, at up to 0.001 and 0.002 S cm−1 for (1:1) and (1:2) molar ratios, respectively. These conductivities indicate significant improvements (>1000×) over the physically blended samples. The results shown here demonstrate the great potential of in situ preparation for the realization of new PEM materials in future high‐temperature and non‐humidified polymer electrolyte membrane fuel cell (PEMFC) applications.

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Free‐breathing combined three‐dimensional phase sensitive late gadolinium enhancement and T1 mapping for myocardial tissue characterization
Authors: Weingärtner Sebastian , Akçakaya Mehmet , Roujol Sébastien , Basha Tamer , Tschabrunn Cory , Berg Sophie , Anter Elad , Nezafat Reza
Published: October 2014

Purpose

To develop a novel MR sequence for combined three‐dimensional (3D) phase‐sensitive (PS) late gadolinium enhancement (LGE) and T1 mapping to allow for simultaneous assessment of focal and diffuse myocardial fibrosis.

Methods

In the proposed sequence, four 3D imaging volumes are acquired with different T1 weightings using a combined saturation and inversion preparation, after administration of a gadolinium contrast agent. One image is acquired fully sampled with the inversion time selected to null the healthy myocardial signal (the LGE image). The other three images are three‐fold under‐sampled and reconstructed using compressed sensing. An acquisition scheme with two interleaved imaging cycles and joint navigator‐gating of those cycles ensures spatial registration of the imaging volumes. T1 maps are generated using all four imaging volumes. The signal‐polarity in the LGE image is restored using supplementary information from the T1 fit to generate PS‐LGE images. The accuracy of the proposed method was assessed with respect to a inversion‐recovery spin‐echo sequence. In vivo T1 maps and LGE images were acquired with the proposed sequence and quantitatively compared with 2D multislice Modified Look‐Locker inversion recovery (MOLLI) T1 maps. Exemplary images in a patient with focal scar were compared with conventional LGE imaging.

Results

The deviation of the proposed method and the spin‐echo reference was < 11 ms in phantom for T1 times between 250 and 600 ms, regardless of the inversion time selected in the LGE image. There was no significant difference in the in vivo T1 times of the proposed sequence and the 2D MOLLI technique (myocardium: 292 ± 75 ms versus 310 ± 49 ms, blood‐pools: 191 ± 75 ms versus 182.0 ± 33). The LGE images showed proper nulling of the healthy myocardium in all subjects and clear depiction of scar in the patient.

Conclusion

The proposed sequence enables simultaneous acquisition of 3D PS‐LGE images and spatially registered 3D T1 maps in a single scan. Magn Reson Med 74:1032–1041, 2015. © 2014 Wiley Periodicals, Inc.
Dynamic contrast‐enhanced MRI in mouse tumors at 11.7 T: comparison of three contrast agents with different molecular weights to assess the early effects of combretastatin A4
Authors: Fruytier A.‐C. , Magat J. , Neveu M.‐A. , Karroum O. , Bouzin C. , Feron O. , Jordan B. , Cron G. O. , Gallez B.
Published: October 2014

Dynamic contrast‐enhanced (DCE)‐MRI is useful to assess the early effects of drugs acting on tumor vasculature, namely anti‐angiogenic and vascular disrupting agents. Ultra‐high‐field MRI allows higher‐resolution scanning for DCE‐MRI while maintaining an adequate signal‐to‐noise ratio. However, increases in susceptibility effects, combined with decreases in longitudinal relaxivity of gadolinium‐based contrast agents (GdCAs), make DCE‐MRI more challenging at high field. The aim of this work was to explore the feasibility of using DCE‐MRI at 11.7 T to assess the tumor hemodynamics of mice. Three GdCAs possessing different molecular weights (gadoterate: 560 Da, 0.29 mmol Gd/kg; p846: 3.5 kDa, 0.10 mmol Gd/kg; and p792: 6.47 kDa, 0.15 mmol Gd/kg) were compared to see the influence of the molecular weight in the highlight of the biologic effects induced by combretastatin A4 (CA4).

Mice bearing transplantable liver tumor (TLT) hepatocarcinoma were divided into two groups (n = 5–6 per group and per GdCA): a treated group receiving 100 mg/kg CA4, and a control group receiving vehicle. The mice were imaged at 11.7 T with a T1‐weighted FLASH sequence 2 h after the treatment. Individual arterial input functions (AIFs) were computed using phase imaging. These AIFs were used in the Extended Tofts Model to determine Ktrans and vp values. A separate immunohistochemistry study was performed to assess the vascular perfusion and the vascular density.

Phase imaging was used successfully to measure the AIF for the three GdCAs. In control groups, an inverse relationship between the molecular weight of the GdCA and Ktrans and vp values was observed. Ktrans was significantly decreased in the treated group compared with the control group for each GdCA.

DCE‐MRI at 11.7 T is feasible to assess tumor hemodynamics in mice. With Ktrans, the three GdCAs were able to track the early vascular effects induced by CA4 treatment. Copyright © 2014 John Wiley & Sons, Ltd.
MOLLI and AIR T1 mapping pulse sequences yield different myocardial T1 and ECV measurements
Authors: Hong KyungPyo , Kim Daniel
Published: October 2014

Both post‐contrast myocardial T1 and extracellular volume (ECV) have been reported to be associated with diffuse interstitial fibrosis. Recently, the cardiovascular magnetic resonance (CMR) field is recognizing that post‐contrast myocardial T1 is sensitive to several confounders and migrating towards ECV as a measure of collagen volume fraction. Several recent studies using widely available Modified Look‐Locker Inversion‐recovery (MOLLI) have reported ECV cutoff values to distinguish between normal and diseased myocardium. It is unclear if these cutoff values are translatable to different T1 mapping pulse sequences such as arrhythmia‐insensitive‐rapid (AIR) cardiac T1 mapping, which was recently developed to rapidly image patients with cardiac rhythm disorders. We sought to evaluate, in well‐controlled canine and pig experiments, the relative accuracy and precision, as well as intra‐ and inter‐observer variability in data analysis, of ECV measured with AIR as compared with MOLLI.

In 16 dogs, as expected, the mean T1 was significantly different (p < 0.001) between MOLLI (891 ± 373 ms) and AIR (1071 ± 503 ms), but, surprisingly, the mean ECV between MOLLI (21.8 ± 2.1%) and AIR (19.6 ± 2.4%) was also significantly different (p < 0.001). Both intra‐ and inter‐observer agreements in T1 calculations were higher for MOLLI than AIR, but intra‐ and inter‐observer agreements in ECV calculations were similar between MOLLI and AIR. In six pigs, the coefficient of repeatability (CR), as defined by the Bland–Altman analysis, in T1 calculation was considerably lower for MOLLI (32.5 ms) than AIR (82.3 ms), and the CR in ECV calculation was also lower for MOLLI (1.8%) than AIR (4.5%).

In conclusion, this study shows that MOLLI and AIR yield significantly different T1 and ECV values in large animals and that MOLLI yields higher precision than AIR. Findings from this study suggest that CMR researchers must consider the specific pulse sequence when translating published ECV cutoff values into their own studies. Copyright © 2014 John Wiley & Sons, Ltd.
Mechanism of tumour vascularization in experimental lung metastases
Authors: Szabo Vanessza , Bugyik Edina , Dezso Katalin , Ecker Nora , Nagy Peter , Timar Jozsef , Tovari Jozsef , Laszlo Viktoria , Bridgeman Victoria L , Wan Elaine , Frentzas Sophia , Vermeulen Peter B , Reynolds Andrew R , Dome Balazs , Paku Sandor
Published: October 2014

The appearance of lung metastases is associated with poor outcome and the management of patients with secondary pulmonary tumours remains a clinical challenge. We examined the vascularization process of lung metastasis in six different preclinical models and found that the tumours incorporated the pre‐existing alveolar capillaries (ie vessel co‐option). During the initial phase of vessel co‐option, the incorporated capillaries were still sheathed by pneumocytes, but these incorporated vessels subsequently underwent different fates dependent on the model. In five of the models examined (B16, HT1080, HT25, C26, and MAT B‐III), the tumour cells gradually stripped the pneumocytes from the vessels. These dissected pneumocytes underwent fragmentation, but the incorporated microvessels survived. In the sixth model (C38), the tumour cells failed to invade the alveolar walls. Instead, they induced the development of vascularized desmoplastic tissue columns. Finally, we examined the process of arterialization in lung metastases and found that they became arterialized when their diameter grew to exceed 5 mm. In conclusion, our data show that lung metastases can vascularize by co‐opting the pulmonary microvasculature. This is likely to have important clinical implications, especially with respect to anti‐angiogenic therapies. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Macrophages from the synovium of active rheumatoid arthritis exhibit an activin A‐dependent pro‐inflammatory profile
Authors: Soler Palacios Blanca , Estrada‐Capetillo Lizbeth , Izquierdo Elena , Criado Gabriel , Nieto Concha , Municio Cristina , González‐Alvaro Isidoro , Sánchez‐Mateos Paloma , Pablos Jose Luis , Corbí Angel L , Puig‐Kröger Amaya
Published: October 2014

Rheumatoid arthritis (RA) is a chronic inflammatory disease whose pathogenesis and severity correlates with the presence of macrophage‐derived pro‐inflammatory cytokines within the inflamed synovium. Macrophage‐derived cytokines fuel the pathological processes in RA and are targets of clinically successful therapies. However, although macrophage polarization determines cytokine production, the polarization state of macrophages in RA joints remains poorly defined. To dissect the molecular basis for the tissue‐damaging effects of macrophages in RA joints, we undertook the phenotypic and transcriptomic characterization of ex vivo isolated CD14+ RA synovial fluid (RA‐SF) macrophages. Flow cytometry and gene profiling indicated that RA‐SF macrophages express pro‐inflammatory polarization markers (MMP12, EGLN3, CCR2), lack expression of markers associated with homeostatic and anti‐inflammatory polarization (IGF1, HTR2B) and exhibit a transcriptomic profile that resembles the activin A‐dependent gene signature of pro‐inflammatory in vitro‐generated macrophages. In fact, high levels of Smad‐activating activin A were found in RA‐SF and, accordingly, the Smad signalling pathway was activated in ex vivo‐isolated RA‐SF macrophages. In vitro experiments on monocytes and macrophages indicated that RA‐SF promoted the acquisition of pro‐inflammatory markers (INHBA, MMP12, EGLN3, CCR2) but led to a significant reduction in the expression of genes associated with homeostasis and inflammation resolution (FOLR2, SERPINB2, IGF1, CD36), thus confirming the pro‐inflammatory polarization ability of RA‐SF. Importantly, the macrophage‐polarizing ability of RA‐SF was inhibited by an anti‐activin A‐neutralizing antibody, thus demonstrating that activin A mediates the pro‐inflammatory macrophage‐polarizing ability of RA‐SF. Moreover, and in line with these findings, multicolour immunofluorescence evidenced that macrophages within RA synovial membranes (RA‐SM) also express pro‐inflammatory polarization markers whose expression is activin A‐dependent. Altogether, our results demonstrate that macrophages from RA synovial fluids and membranes exhibit an MMP12+ EGLN3+ CCR2+ pro‐inflammatory polarization state whose acquisition is partly dependent on activin A from the synovial fluid. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
A comment on continuous spin representations of the Poincaré group and perturbative string theory
Authors: Font A. , Quevedo F. , Theisen S.
Published: October 2014

We make a simple observation that the massless continuous spin representations of the Poincaré group are not present in perturbative string theory constructions. This represents one of the very few model‐independent low‐energy consequences of these models.
Sensitivity testing of WRF parameterizations on air–sea interaction and its impact on water cycle in the Gulf of Guinea
Authors: Meynadier Rémi , de Coëtlogon G. , Bastin S. , Eymard L. , Janicot S.
Published: October 2014

A strong ocean–atmosphere coupling exists in the eastern equatorial region of the tropical Atlantic at intraseasonal time‐scales, with a significant contribution in the functioning and partitioning of the water cycle in spring over the ocean, as well as later in the season over West Africa. Uncertainties in simulating the air–sea interaction in the Gulf of Guinea and its impact on the water cycle are studied using modelling experiments during spring–summer 2006 with the Weather Research and Forecasting model (WRF). Tested parameters include physical packages of cumulus (Cu), planetary boundary‐layer (PBL), microphysics (MP) and radiative (RAD) schemes. The simulations are compared with satellite‐based observations, ship‐based radiosonde data and state‐of‐the‐art atmospheric model reanalyses. Results show that cumulus, microphysics and radiative parametrizations exert a large influence on the simulated seasonal distribution of regional convective rainfall. Non‐local PBL schemes are determinant to simulate the correct surface wind pattern and water vapor distribution in order to get realistic precipitation from intra‐seasonal to diurnal scales, especially over the ocean where the nocturnal rainfall representation is improved.
Effect of resistant starch structure on short‐chain fatty acids production by human gut microbiota fermentation in vitro
Authors: Zhou Zhongkai , Cao Xiaohong , Zhou Julia Y. H.
Published: October 2014

Resistant starch (RS) from uncooked and cooked high amylose starch (HAS) was used to investigate the effect of RS structure on the production of short‐chain fatty acids (SCFA) using a static anaerobic in vitro system. The pH value of culture correlated well to the production of total SCFA after the fermentation (R2 = 0.969). Most importantly, fermentation of RS from thermally treated starch under no moisture condition produced the highest concentration of SCFA and the greatest ratios of butyrate/acetate and butyrate/total SCFA, followed by the fermentation of RS from uncooked HAS. FTIR analysis suggests that all the RS exhibited a relatively higher organized structure compared to its corresponding original starch. The analysis of molecular structure by HPLC showed that the most pronounced difference in molecular composition of RS between the group favoring greater butyrate production and the group supporting a lower butyrate production was that larger molecules (amylopectin fraction) still existed in the former group but not in the latter group. Thus, it can be concluded that RS structure, in particular molecular structure is one of the key factors manipulating SCFA production in amount and proportion.
Starch digestibility and predicted glycaemic index (pGI) in starchy foods consumed in Mexico
Authors: Sáyago‐Ayerdi Sonia G. , Tovar Juscelino , Zamora‐Gasga Victor M. , Bello‐Pérez Luis A.
Published: October 2014

Different starchy foods are frequently consumed in the Mexican diet. Some of them were developed by Pre‐Columbian Mesoamerican civilizations. Until today, common beans (Phaseolus vulgaris), tortillas made with maize (Zea mays) and related maize‐based products are some of the main staple foods. Additionally, wheat‐based foods are also important starch sources, incorporated in different dishes. This review deals with the in vitro digestibility of the starch fraction in foods commonly consumed in Mexico, paying attention to the addition of unconventional, natural raw materials, such as flour and starch from unripe banana, mango dietary fibre and common legumes. These ingredients enhance potential health‐beneficial properties of the diet in cases of non‐communicable diseases, particularly those related to obesity and glycaemic homeostasis. Since Mexico is among the countries with greatest indices of overweight and obesity, this paper reviews the in vitro starch availability features, including predicted GI, of various Mexican foods. Attention is also paid to the effect of cold storage conditions on starch digestibility. As an example, starch digestibility in blue maize tortillas (58%) is lower than in white tortillas (70–89%) and a maize tortilla/boiled bean composite dish ranks as a food with low predicted GI (pGI = 51).
Effects of succinic acid cross‐linking and mono‐phosphorylation of oxidized cassava starch on its paste viscosity stability and sizability
Authors: Zhu Zhifeng , Zheng Hao , Li Xiaochun
Published: October 2014

Oxidized cassava starch (OCS) was cross‐linked with succinic acid (SA) and then phosphorylated with sodium tripolyphosphate to improve viscosity stability and usability of OCS for warp sizing. The level of cross‐linking (LCL) and the degree of substitution (DS) of the phosphorylation were determined according to the stability, water dispersibility, adhesion‐to‐fibers, desizability, aerobic biodegradation, and film properties of the cross‐linked and phosphorylated OCS. The cross‐linking exhibited significant effects on the stability, water dispersibility, adhesion, film properties, and desizability, but was less sensitive to the biodegradation. The phosphorylation after cross‐linking not only showed active effect on the usability, but also did not exhibit any adverse influence upon the stability. Suitable LCL and DS values resulted in stable viscosity, strong adhesion‐to‐fiber, tough starch film, and good desizability. Low LCL and DS could be employed to enhance the stability and improve the usability of OCS for warp sizing. Based on the stability and usability, the LCL and DS values were recommended to be 1 cross‐link for 370‐590 AGU units and 0.038, respectively.
A fractal analysis approach for predicting starch retrogradation from X‐ray diffractograms
Authors: Utrilla‐Coello Rubi G. , Bello‐Perez Luis A. , Lara Victor H. , Vernon‐Carter Eduardo J. , Alvarez‐Ramirez Jose
Published: October 2014

Commonly, the interpretation of starch XRD patterns is hampered by the lack of sharp intensity peaks and the presence of a broad background band. This work proposes a fractal analysis approach for the analysis of XRD patterns obtained from starches. The idea behind the fractal analysis approach is that the broad background pattern contains information pertaining the complexity of the material structure that presumably is arranged within fractal geometries. Thus, the quest is to detect regularities reflected as auto‐correlations of the complex intensity signal. The fractal rescaled range (R/S) analysis is proposed in this work to obtain an index for the regularity of the complex intensity signal. In turn, such regularity index should reflect the regularity of the complex starch structure. The approach is illustrated with native starches from maize, banana, and potato, showing that the former is more regular (i.e. more ordered starch structure) than the latter two. Gelatinization is used to contrast the fractal analysis results. In turn, it is shown that gelatinized starches exhibit a nearly amorphous structure reflected as non‐correlated XRD sequences.
Physicochemical, morphological, and functional properties of flour and starch from peach palm (Bactris gasipaes K.) fruit
Authors: Valencia Germán Ayala , Moraes Izabel Cristina Freitas , Lourenço Rodrigo Vinicius , Bittante Ana Mônica Quinta Barbosa , Sobral Paulo José do Amaral
Published: October 2014

To characterize the flour and starch from peach palm fruit, a non‐conventional raw material, these powders were studied by means of chemical composition, SEM, particle size analyzer, XRD, FTIR, and differential scanning calorimeter, with different water contents. The rheological properties of the solutions and suspensions also were evaluated. Results showed that flour and starch powders have high starch contents (between 73.0 and 84.5%) with average particle size between 9.8 µm (flour) and 8.4 µm (starch). Thermograms revealed endothermic peaks that were affected by hydration conditions between 70–72°C for flour and 61–62°C for starch. Solutions of peach palm fruit flour and starch had a pseudoplastic behavior at 30°C that can be fit well to the power‐law model. Peach palm fruit is a non‐conventional source of flour and starch, but the results proved that these powders could have promising industrial applications, due to their physicochemical properties being similar to those reported for other starches.
Physicochemical properties of pregelatinized wheat and corn starches in the presence of different concentrations of L‐ascorbic acid
Authors: Majzoobi Mahsa , Kaveh Zahra , Farahnaky Asgar , Blanchard Christopher L.
Published: October 2014

Pregelatinized starches are commonly used in many foods, particularly those processed at low temperature, to enhance viscosity and provide a desirable texture. The functional properties of the pregelatinized starch can be affected by other components used in food systems. The main purpose of this study was to determine the effects of various levels of L‐ascorbic acid (L‐AA) including 0, 100, 500, and 1000 mg/kg (starch basis) on some functional properties of pregelatinized wheat (PGW) and corn (PGC) starches. The pH of the samples was reduced significantly as the level of L‐AA increased. Cold‐water solubility increased while water absorption decreased with increasing concentrations of L‐AA and exposure time. Cold water viscosity as determined by a Rapid Visco Analyser decreased as the amount of L‐AA increased. Addition of L‐AA reduced gel firmness, increased turbidity during storage for 72 h and enhanced syneresis during five freeze–thaw cycles. The general behaviors of PGW and PGC starches in the presence of different levels of L‐AA were similar. However, PGW starch showed higher cold‐water viscosity, harder gel texture, more turbidity, and greater syneresis than the PGC starch.
Effect of starch xero‐ and aerogels preparation on the supercritical CO2 impregnation of thymol
Authors: Milovanovic Stoja , Jankovic‐Castvan Ivona , Ivanovic Jasna , Zizovic Irena
Published: October 2014

In this study, for the first time, the supercritical solvent impregnation (SSI) technique has been used to test the incorporation of thymol into starch gels. Corn and tapioca starch hydrogels prepared at different temperatures (70–100°C) were converted to the acetogels and subsequently dried with supercritical CO2 or air to obtain aero‐ or xerogels, respectively. Starch xero‐ and aerogels were impregnated with thymol in a high pressure view cell using supercritical CO2 at 15.5 MPa and 35°C during 24 h. The influence of the botanical origin of starch, temperature for hydrogels preparation (Tgel‐h) and drying method on the gel morphology and thymol impregnation yields was discussed. Determined thymol SSI yields were in the range of 1.15–4.02% for the corn and 0.58–3.63% for the tapioca starch gels. Xerogels had higher thymol loading capacities (1.76–4.02%) than aerogels (0.58–3.31%) at given SSI conditions. Gel morphology and thymol SSI yields were positively affected by the Tgel‐h increase. The xerogel obtained from the corn starch hydrogel prepared at 100°C had the largest specific surface area (5.52 m2/g) and thymol loading capacity (4.02%) at given SSI conditions. These results, along with a simple and low‐cost production, indicated the great potential of the corn starch xerogel for commercial use as a carrier in pharmaceuticals and nutraceuticals.
Our Expedition in Eight‐Membered Ring Compounds: From Planar Dehydrocyclooctenes to Tub‐Shaped Chiral Tetraphenylenes
Authors: Han Jian‐Wei , Li Xin , Wong Henry N. C.
Published: October 2014

Our research focus for almost forty years concerning eight‐membered ring compounds is herein summarized. The design and preparation of these structurally unique compounds featuring a central cyclooctene ring are described in the context of their planar or tub‐shaped conformations. Furthermore, their intrinsic properties and potential applications are also presented.
Array comparative genomic hybridization and fetal congenital heart defects: a systematic review and meta‐analysis
Authors: Jansen F. A. R. , Blumenfeld Y. J. , Fisher A. , Cobben J. M. , Odibo A. O. , Borrell A. , Haak M. C.
Published: October 2014

Objective

Array comparative genomic hybridization (aCGH) is a molecular cytogenetic technique that is able to detect the presence of copy number variants (CNVs) within the genome. The detection rate of imbalances by aCGH compared to standard karyotyping and 22q11 microdeletion analysis by fluorescence in‐situ hybridization (FISH), in the setting of prenatally‐diagnosed cardiac malformations, has been reported in several studies. The objective of our study was to perform a systematic literature review and meta‐analysis to document the additional diagnostic gain of using aCGH in cases of congenital heart disease (CHD) diagnosed by prenatal ultrasound examination, with the aim of assisting clinicians to determine whether aCGH analysis is warranted when an ultrasonographic diagnosis of CHD is made, and to guide counseling in this setting.

Methods

Articles in PubMed, EMBASE and Web of Science databases from January 2007 to September 2014 describing CNVs in prenatal cases of CHD were included. Search terms were: ‘array comparative genomic hybridization’, ‘copy number variants’ and ‘fetal congenital heart defects’. Articles regarding karyotyping or 22q11 deletion only were excluded.

Results

Thirteen publications (including 1131 cases of CHD) met the inclusion criteria for the analysis. Meta‐analysis indicated an incremental yield of 7.0% (95% CI, 5.3–8.6%) for the detection of CNVs using aCGH, excluding aneuploidy and 22q11 microdeletion cases. Subgroup results showed a 3.4% (95% CI, 0.3–6.6%) incremental yield in isolated CHD cases, and 9.3% (95% CI,  6.6–12%) when extracardiac malformations were present. Overall, an incremental yield of 12% (95% CI, 7.6–16%) was found when 22q11 deletion cases were included. There was an additional yield of 3.4% (95% CI, 2.1–4.6%) for detecting variants of unknown significance (VOUS).

Conclusions

In this review we provide an overview of published data and discuss the benefits and limitations of using aCGH. If karyotyping and 22q11 microdeletion analysis by FISH are normal, using aCGH has additional value, detecting pathogenic CNVs in 7.0% of prenatally diagnosed CHD, with a 3.4% additional yield of detecting VOUS. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.
Establishment of spatial pattern
Authors: Slack Jonathan
Published: October 2014

An overview and perspective are presented of mechanisms for the development of spatial pattern in animal embryos. It is intended both for new entrants to developmental biology and for specialists in other fields, with only a basic knowledge of animal life cycles being required. The first event of pattern formation is normally the localization of a cytoplasmic determinant in the egg, either during oogenesis or post‐fertilization. Following cleavage to a multicellular stage, some cells contain the determinant and others do not. The determinant confers a specific developmental pathway on the cells that contain it, often making them the source of the first extracellular signal, or inducing factor. Inducing factors often form concentration gradients to which cells respond by up or downregulating genes at various concentration thresholds. This enables an initial situation consisting of two cell states (with or without the determinant) to generate a multistate pattern. Multiple rounds of gradient signaling, interspersed with phases of morphogenetic movements, can generate a complex pattern using a small number of signals and responding genes. Development proceeds in a hierarchical manner, with broad body subdivisions being specified initially, and becoming successively subdivided to give individual organs and tissues composed of multiple cell types in a characteristic arrangement. Double gradient models can account for embryonic regulation, whereby a similarly proportioned body pattern is formed following removal of material. Processes that are involved at the later stages include the formation of repeating structures by the combination of an oscillator with a gradient, and the formation of tissues with one cell type scattered in a background of another through a process called lateral inhibition. This set of processes make up a ‘developmental toolkit’ which can be deployed in various sequences and combinations to generate a very wide variety of structures and cell types. WIREs Dev Biol 2014, 3:379–388. doi: 10.1002/wdev.144

This article is categorized under:

Establishment of Spatial and Temporal Patterns > Cytoplasmic Localization

Establishment of Spatial and Temporal Patterns > Gradients

Establishment of Spatial and Temporal Patterns > Repeating Patterns and Lateral Inhibition
H2 generation from alkaline electrolyzer
Authors: Bodner Merit , Hofer Astrid , Hacker Viktor
Published: October 2014

Water electrolysis is a promising approach to hydrogen production from renewable energy sources. Even though it is not necessarily environmentally friendly and a large number of possible feedstocks for hydrogen production include fossil resources such as coal, natural gas, and mineral oil, but also biomass, water, and components such as ethanol, methane, or ammonia can be used for hydrogen production. Also, a large variety of different energy sources can be used for hydrogen production. The combination of hydrogen production with renewable energy systems, such as photovoltaics, hydropower, or wind energy is very suitable though. Many innovative processes have been subject to intense research and some have already reached high efficiencies. Alkaline water electrolyzers with anion‐conducting membranes hold many advantages in comparison to other systems. As cheaper, non‐noble metals are stable in alkaline media, the relatively low cost of the electrode materials is one of the main advantages of alkaline systems over electrolyzers using proton‐conducting electrolytes. Therefore, the main part of published literature on alkaline electrolysis describes electrodes based on low cost materials such as nickel for both anode and cathode. Yet still alkaline water electrolyzers have to compete against other forms of hydrogen production, such as steam reforming of natural gas. Even though many studies expect water electrolysis to become economically viable on a long‐term basis, conventional hydrogen production is still hard to under‐price. WIREs Energy Environ 2015, 4:365–381. doi: 10.1002/wene.150

This article is categorized under:

Fuel Cells and Hydrogen > Science and Materials
Semiconducting single-walled carbon nanotubes synthesized by S-doping
Authors: Li Z. J. , Wang L. , Su Y. J. , Liu P. , Zhang Y. F.
Published: October 2014

An approach was presented for synthesis of semiconducting single-walled carbon nanotubes (SWNTs) by sulfur (S) doping with the method of graphite arc discharge. Raman spectroscopy, UV-vis-NIR absorption spectroscopy and electronic properties measurements indicated the semconducting properties of the SWNTs samples. Simulant calculation indicated that S doping could induce convertion of metallic SWNTs into semiconducting ones. This strategy may pave a way for the direct synthesis of pure semiconducting SWNTs.
The electrical switching characteristics of single copper tetra-cyanoquinodimethane nanowire
Authors: Zheng K. B. , Shen H. T. , Ye C. N. , Li J. L. , Sun D. L. , Chen G. R.
Published: October 2014

In this paper, method combined vapor transportation with in-situ chemical reaction is employed to synthesize Cu(TCNQ) nanowires. The typical diameter of nanowires is 50–500 nm with high uniformity. The electrical switching characteristics of single nanowire are observed. The ON-OFF resistance ratio for switching reaches 104. The investigation reveals a linear relationship between the switching threshold and the spacing between the two electrodes. The temporal response of the switching process is 30 ns and the switch exhibits good reproducibility. The collapse of the nanowire under the condition of current surge is also discussed. It is believed that the Cu(TCNQ) nanowire could be promising for applications in nanoelectronics.
Optical properties of ZnO and Mn-doped ZnO nanocrystals by vapor phase transport processes
Authors: Wang Z. , Ma X. Y. , Song J. W. , Yao J. H.
Published: October 2014

In this paper we investigated the optical properties of ZnO and Mn doped ZnO nanocrystals that were fabricated by a vapor phase transport growth process, using zinc acetate dihydrate with or without Mn in a constant O2/Ar mixture gas flowing through the furnace at 400≈600°C, respectively. The as grown ZnO nanocrystals are homogeneous with a mean size of 19 nm observed by scanning electron microscope (SEM). The optical characteristics were analyzed by absorption spectra and photoluminescence (PL) spectra at room-temperature. For ZnO nanocrystals, a strong and predominant UV emission peaked at 377 nm was found in the PL spectra. For Mn doped ZnO nanocrystals, in addition to the strong UV emission, a strong blue emission peaked at 435 nm was observed as well. By doping Mn ions, the major UV emission shifts from 377 nm to 408 nm, showing that Mn ions were not only incorporated into ZnO Ncs, but also introduced an impurity level in the bandgap. Moreover, with the concentration of Mn increasing, the relative intensities of the two emissions change largely, and the photoluminescence mechanism of them is discussed.
Experimental evidence for the formation mechanism of metallic catalyst-free carbon nanotubes
Authors: Tang Y. H. , Li X. C. , Li J. L. , Lin L. W. , Xu H. F. , Huang B. Y.
Published: October 2014

Our work reported that the so-called pure carbon nanotubes (CNTs) can be synthesized without metallic catalyst by chemical vapor deposition (CVD). The as-prepared CNTs have average diameter of 50 nm and length over several microns. Analysis of intermediate objects in the products indicates that their formation mechanism follows the wire-to-tube model. Besides, according to thermodynamic analysis of the driving force combing with experimental results, we find that the thermal gradient can effectively favor the formation of CNTs in our metallic catalyst-free CVD.
Influence of plasma condition on carbon nanotube growth by rf-PECVD
Authors: Man Y. H. , Li Z. C. , Zhang Z. J.
Published: October 2014

Carbon nanotubes (CNTs) have been synthesized from Ar-CH4 mixtures using rf-plasma enhanced chemical vapor deposition (rf-PECVD) at 500°C. Reduction gases such as H2 and NH3 were found unnecessary for carbon nanotube formation compared to thermal CVD. The relationship between the growth of CNTs and the plasma condition in PECVD has been investigated by in situ self bias measurement. Plasma conditions were controlled by changing the interelectrode distance, rf power and the applied substrate negative bias. By increasing the interelectrode distance and rf power, the spatial density of CNTs was on a rise as a result of the increase in ions density and self bias. As the applied substrate negative bias increased, the spatial density of CNTs decreased possibly due to the positive ions over bombarding effect.
State-space approach to vibration of gold nano-beam induced by ramp type heating
Authors: Youssef Hamdy M. , Elsibai Khaled A.
Published: October 2014

In the nanoscale beam, two effects become domineering. One is the non-Fourier effect in heat conduction and the other is the coupling effect between temperature and strain rate. In the present study, a generalized solution for the generalized thermoelastic vibration of gold nano-beam resonator induced by ramp type heating is developed. The solution takes into account the above two effects. State-space and Laplace transform methods are used to determine the lateral vibration, the temperature, the displacement, the stress and the strain energy of the beam. The effects of the relaxation time and the ramping time parameters have been studied.
Current sustainability and electromigration of Pd, Sc and Y thin-films as potential interconnects
Authors: Yang Yong , Xu Shengyong , Xie Sishen , Peng Lian-Mao
Published: October 2014

The progress on novel interconnects for carbon nanotube (CNT)-based electronic circuit is by far behind the remarkable development of CNT-field effect transistors. The Cu interconnect material used in current integrated circuits seems not applicable for the novel interconnects, as it requires electrochemical deposition followed by chemical-mechanical polishing. We report our experimental results on the failure current density, resistivity, electromigration effect and failure mechanism of patterned stripes of Pd, Sc and Y thin-films, regarding them as the potential novel interconnects. The Pd stripes have a failure current density of (8∼10)×106 A/cm2 (MA/cm2), and they are stable when the working current density is as much as 90% of the failure current density. However, they show a resistivity around 210 μΩ·cm, which is 20 times of the bulk value and leaving room for improvement. Compared to Pd, the Sc stripes have a similar resistivity but smaller failure current density of 4∼5 MA/cm2. Y stripes seem not suitable for interconnects by showing even lower failure current density than that of Sc and evidence of oxidation. For comparison, Au stripes of the same dimensions show a failure current density of 30 MA/cm2 and a resistivity around 4 μΩ·cm, making them also a good material as novel interconnects.
Nanofluid Applications in Future Automobiles: Comprehensive Review of Existing Data
Authors: Senthilraja S. , Karthikeyan M. , Gangadevi R.
Published: October 2014

In recent years fluids containing suspension of nanometer sized particles have been an active area of research due to their enhanced thermo physical properties over the base fluids like water, oil etc. Nanofluids possess immense potential applications to improve heat transfer and energy efficient in several areas including automobile, micro electronics, nuclear, space and power generation. Nowadays most of the researchers are trying to use the nanofluids in automobile for various applications such as coolant, fuel additives, lubricant, shock absorber and refrigerant. The goal of this paper is to create the awareness on the promise of nanofluids and the impact it will have on the future automotive industry. This paper also presents a comprehensive data of nanofluids application in automobile for various aspects.
Relating Coalition Capacity to the Adoption of Science‐Based Prevention in Communities: Evidence from a Randomized Trial of Communities That Care
Authors: Shapiro Valerie B. , Oesterle Sabrina , Hawkins J. David
Published: October 2014

Coalition‐based efforts that use a science‐based approach to prevention can improve the wellbeing of community youth. This study measured several coalition capacities that are hypothesized to facilitate the adoption of a science‐based approach to prevention in communities. Using data from 12 coalitions participating in a community‐randomized trial of the prevention strategy Communities That Care (CTC), this paper describes select measurement properties of five salient coalition capacities (member substantive knowledge of prevention, member acquisition of new skills, member attitudes toward CTC, organizational linkages, and influence on organizations), as reported by coalition members, and examines the degree to which these capacities facilitated the community leader reports of the community‐wide adoption of a science‐based approach to prevention. Findings indicated that the five coalition capacities could be reliably measured using coalition member reports. Meta‐regression analyses found that CTC had a greater impact on the adoption of a science‐based prevention approach in 12 matched pairs of control and CTC communities where the CTC coalition had greater member (new skill acquisition) and organizational capacities (organizational linkages).