bluuebunny/crossref_metadata_2025 huggingface dataset:
The design of optimal real Gabor filters and their applications in fabric defect detection
Authors: Chen Zehong , Feng Xiaoxia
Published: July 2015

Fabric defect detection has been recognised as one of the key challenges for automatic production, and Gabor filters are one of the most useful tools in detecting fabric defects. The half‐peak tangent method is applied in real Gabor filter design so that the filters can cover the frequency of defects as much as possible. Meanwhile, the half‐peak‐magnitude contours of the neighbouring filters are tangential. On this basis, two optimal orientations are selected by applying direction masks, and the optimal scale at each optimal orientation is determined according to the signal‐to‐noise ratio. In this way, two optimal real Gabor filters are obtained. A new algorithm based on the two optimal filters is proposed for fabric defect detection. A series of experiments are carried out for 46 fabric defect images combined with 46 corresponding reference fabric images, in order to verify the effectiveness of the new algorithm. The experimental results obtained show that the new algorithm can accurately detect defects in grey fabric defect images as well as in colour images. For the 46 fabric defect images, the detection rate is 95.66%, indicating that the new algorithm performs well. In addition, comparison of the new algorithm with other algorithms in the literature demonstrates that the new algorithm is more effective in the detection of several fabric defect images.
An investigation of an instrument‐based method for assessing colour fastness to light of photochromic textiles
Authors: Aldib Mohanad
Published: July 2015

A new method for evaluating the light fastness of photochromic fabrics was established, aimed at replacing the conventional method with an instrumental method. This method was based on comparing the colour difference of photochromic fabrics after light exposure with measured values of the colour differences of the blue wool references after fixed periods of light exposure. This method benefits from replacing the traditional visual evaluation of colour difference between exposed and unexposed areas of textile samples with a more accurate, instrument‐based measurement of the colour difference. The light fastness is then evaluated by comparing the colour difference with tabulated values of colour differences brought about by light exposure, for increased periods of time, of standard blue wool references. This method could be used for measuring light fastness of both traditional and photochromic fabrics. However, blue wool references and tested samples should be exposed to light under similar conditions when using this method to measure colour fastness to light of fabrics.
Synthesis, characterisation, and applications of isoindigo/Pechmann dye heteroanalogue hybrid dyes on polyester fabric
Authors: Aysha Tarek , El‐Sedik Mervat , Mashaly Hamada M. , El‐Apasery Morsy A. , Machalický Oldřich , Hrdina Radim
Published: July 2015

A series of new dyes based on the N‐analogue of Pechmann hybrid dyes were prepared by the condensation of different 5‐aryl derivatives of pyrrolinone ester (phenyl, 4‐bromophenyl, thienyl, and biphenyl) with isatin. N‐Alkylated derivatives were also prepared using bromoethyl acetate. Full 1H and 13C NMR assignment was performed. All prepared dyes were soluble in most organic solvents: N‐alkylated derivatives had better solubility than non‐alkylated derivatives. The UV‐vis absorption spectra of the derivatives under study are quite similar and exhibit maxima in the 509–526 nm range. No E/Z photoisomerisation is observed. The dyeing process, dye exhaustion on polyester, and the fastness properties of the dyes were examined.
A multispectral imaging approach to colour measurement and colour matching of single yarns without winding
Authors: Luo Lin , Shen Hui‐Liang , Shao Si‐Jie , Xin John H
Published: July 2015

This paper investigates a multispectral imaging approach to colour measurement and colour matching of single yarns. The small size of a single yarn makes it impossible for spectrophotometers directly to acquire its spectral reflectance. Multispectral imaging systems, on the other hand, have the potential to measure the reflectance of single yarns as they can record both the spectral and the spatial information of a sample. A multispectral imaging system, namely imaging colour measurement, has been developed to conduct colour measurement of single yarns. A single yarn is first detected from backgrounds by a modified K‐means clustering method. The reflectance of the single yarn is then specified by an averaging method. Comparative experiments based on 100 pairs of single yarns and corresponding yarn windings show that the reflectance magnitude of a single yarn acquired by imaging colour measurement is smaller than that of corresponding yarn winding measured by a Datacolor 650 spectrophotometer. Experiments on 16 single yarns show that the repeatability and spatial reproducibility of the imaging colour measurement system in measuring a single yarn colour are 0.1185 and 0.2827 CMC(2:1) units. A colour matching comparison experiment (pass or fail), using 24 pairs of single yarns and corresponding pairs of solid‐colour yarn dyed fabrics, shows that single yarns measured by imaging colour measurement can achieve similar colour matching results to solid‐colour yarn dyed fabrics measured by the Datacolor 650 spectrophotometer, with degrees of similarity of 87.5 and 83.3% when the CMC(2:1) and CIE2000(2:1:1) colour difference formulas are employed.
Quantification of Aerosol Hydrofluoroalkane HFA‐134a Elimination in the Exhaled Human Breath Following Inhaled Corticosteroids Administration
Authors: Shin Hye‐Won , Barletta Barbara , Yoonessi Leila , Meinardi Simone , Leu Szu‐Yun , Radom‐Aizik Shlomit , Randhawa Inderpal , Nussbaum Eliezer , Blake Donald R. , Cooper Dan M.
Published: July 2015

Inhaled corticosteroids (ICS) and β2‐agonists are the primary pharmacotherapies of asthma management. However, suboptimal medication compliance is common in asthmatics and is associated with increased morbidity. We hypothesized that exhaled breath measurements of the aerosol used in the inhaled medications might prove useful as surrogate marker for asthma medication compliance. To explore this, 10 healthy controls were recruited and randomly assigned to ICS (Flovent HFA) or short acting bronchodilators (Proventil HFA). Both inhalers contain HFA‐134a as aerosol propellant. Exhaled breath sampling and pulmonary function tests were performed prior to the inhaler medication dispersion, immediately after inhalation, then at 2, 4, 6, 8, 24, and 48 hours postadministration. At baseline, mean (SD) levels of HFA‐134a in the breath were 252 (156) pptv. Immediately after inhalation, HFA‐134a breath levels increased to 300 × 106 pptv and were still well above ambient levels 24 hours postadministration. The calculated ratio of forced expiratory volume in 1 second over forced vital capacity did not change over time following inhaler administration. This study demonstrates, for the first time, that breath HFA‐134a levels can be used to assess inhaler medication compliance. It may also be used to evaluate how effectively the medicine is delivered.
Somatic ATP2A2 mutation in a case of papular acantholytic dyskeratosis: mosaic Darier disease
Authors: Knopp Eleanor A. , Saraceni Corey , Moss Jeremy , McNiff Jennifer M. , Choate Keith A.
Published: July 2015

Papular acantholytic dyskeratosis, also known as acantholytic dermatosis of the vulvocrural (or anogenital) area, is an uncommon eruption reported predominantly in women. This entity manifests with pruritic papules in the groin/anogenital area and less commonly on the chest. The pathobiology of papular acantholytic dyskeratosis is uncertain. A 62‐year‐old woman presented with multiple verrucous‐appearing lesions in the groin and on the chest showing acantholytic dyskeratosis on histopathology. Given histological similarity of these papular acantholytic dyskeratosis lesions to Darier disease due to inherited ATP2A2 mutation, we screened affected and normal tissue and peripheral blood in our patient for mutations in ATP2A2. We found an identical ATP2A2 p.706D>N mutation in multiple independent papular acantholytic dyskeratosis lesions that was not present in uninvolved skin or peripheral blood DNA. These findings establish somatic mosaicism of ATP2A2 mutations as a genetic cause for papular acantholytic dyskeratosis.
A sublethal effect on native Anthocoris nemoralis through competitive interactions with invasive Harmonia axyridis
Authors: HOWE ANDY G. , RANSIJN JOHANNES , RAVN HANS P.
Published: July 2015

1. The invasive ladybird Harmonia axyridis Pallas (Coleoptera: Coccinellidae) is implicated in declines of native ladybirds with intraguild predation identified as an underlying mechanism, however, less studied are the effects on non‐coccinellid predators. Intraguild predation between Anthocoris nemoralis Fabricius (Heteroptera: Anthocoridae) and H. axyridis and the relative effects of inter‐ and intraspecific competition on predators on potted Tilia cordata Mill. was investigated, at two aphid densities.

2. Intraguild predation was unidirectional in favour of H. axyridis in Petri dishes although a low level of ladybird egg predation by A. nemoralis occurred. However, on trees intraguild predation was rare.

3. A positive effect of aphid density on H. axyridis weight gain, and increased survival when reared with A. nemoralis on potted trees indicated stronger effects of intraspecific competition on H. axyridis. Consistent suppression of aphids by ladybirds revealed their superior competition for aphids.

4. Anthocoris nemoralis weight gain was reduced when reared with H. axyridis on potted trees, indicating a potential for a sublethal effect through interspecific competition. Survivorship of A. nemoralis did not differ between con‐ and heterospecific treatments, but high aphid density enhanced A. nemoralis survival. Overall, high mortality among nymphs across treatments suggested effects related to both inter‐ and intraspecific competition for resources.

5. Results provide evidence of a sublethal effect by invasive H. axyridis through resource competition, suggesting that where these predators co‐occur, competitive interactions for shared prey are more likely to affect A. nemoralis populations than intraguild predation by H. axyridis.
Involvement of PKA and ERK pathways in ghrelin‐induced long‐lasting potentiation of excitatory synaptic transmission in the CA1 area of rat hippocampus
Authors: Cavalier Mélanie , Crouzin Nadine , Ben Sedrine Azza , de Jesus Ferreira Marie Celeste , Guiramand Janique , Cohen‐Solal Catherine , Fehrentz Jean‐Alain , Martinez Jean , Barbanel Gérard , Vignes Michel
Published: July 2015

Acute effects of ghrelin on excitatory synaptic transmission were evaluated on hippocampal CA1 synapses. Ghrelin triggered an enduring enhancement of synaptic transmission independently of NMDA receptor activation and probably via postsynaptic modifications. This ghrelin‐mediated potentiation resulted from the activation of GHS‐R1a receptors as it was mimicked by the selective agonist JMV1843 and blocked by the selective antagonist JMV2959. This potentiation also required the activation of PKA and ERK pathways to occur as it was inhibited by KT5720 and U0126, respectively. Moreover it most probably involved Ca2+ influxes as both ghrelin and JMV1843 elicited intracellular Ca2+ increases, which were dependent on the presence of extracellular Ca2+ and mediated by L‐type Ca2+ channels opening. In addition, ghrelin potentiated AMPA receptor‐mediated [Ca2+]i increases while decreasing NMDA receptor‐mediated ones. Thus the potentiation of synaptic transmission by GHS‐R1a at hippocampal CA1 excitatory synapses probably results from postsynaptic mechanisms involving PKA and ERK activation, which are producing long‐lasting enhancement of AMPA receptor‐mediated responses.
Resistance to drought affects persistence of alternative regimes in shallow lakes of the Boreal Plains (Alberta, Canada)
Authors: Cobbaert Danielle , Wong Agnes S. , Bayley Suzanne E.
Published: July 2015

We examined how lake and landscape factors affected the persistence of alternative regimes in 23 predominantly fishless, shallow lake ecosystems over seven years in the Boreal Plains, Alberta, Canada. The alternative regimes were dominance by SAV (submerged aquatic vegetation) or by phytoplankton.

The relationship between alternative regime persistence and a suite of lake and landscape variables were determined using regression tree analysis. We also compared the environmental variables and biological communities among alternative regimes using Kruskal–Wallis nonparametric tests and post hoc tests.

Persistence of the SAV‐rich regime was best predicted by water level stability. Switches from a SAV‐rich regime to a phytoplankton‐rich regime have been attributed to drought, which concentrates total phosphorus (TP) and other solutes and increases turbidity, favouring phytoplankton dominance. Lakes with stable water levels are inferred as less sensitive to drought, and presumably experience less evapoconcentration during drought, which helps maintain the SAV‐rich regime. Lakes with more water level drawdown may also delay or inhibit SAV growth through physical disturbance.

In contrast, the persistence of the phytoplankton‐rich regime was highest in lakes with higher TP and a lower proportion of surrounding wetlands. We postulate that lakes with less wetland in the buffer are more responsive to variations in precipitation because these systems have a smaller water storage capacity and lack peatlands that otherwise attenuate the effects of drought via shallow groundwater inputs.

The relative persistence of lakes in the study area was related to lake and landscape factors that affect the relative sensitivity of the lakes to drought conditions. The biological community in these predominantly fishless lakes appears to play a weak role in maintaining the alternative regimes compared to fish‐bearing lake systems.
Life history influences the vulnerability of New Zealand galaxiids to invasive salmonids
Authors: Jones Peter E. , Closs Gerard P.
Published: July 2015

Invasion biology often focuses on the life‐history traits and the physiological tolerance of introduced species, and on assessing the suitability of receiving habitats. Few studies have examined how trait variation in recipient communities affects the responses of native fauna to pressures from invasive species.

This study examines how previously identified life‐history differences in a species‐complex of native New Zealand galaxiid fish influence their spatial interactions with invasive salmonids (mainly Salmo trutta, but also Oncorhynchus mykiss, O. tshawytscha and Salvelinus fontinalis).

A combination of a long‐term, broad‐scale, presence–absence dataset and a more intensive electrofishing survey was used to examine the extent to which galaxiid species distributions overlap with those of salmonids, and to assess demographic effects associated with salmonid presence. A generalised linear modelling approach was used to test the effect of life history on galaxiid–salmonid interactions while taking into account the possible confounding effects of habitat differences between species distributions.

Galaxiid species with ‘fast’ life‐history traits (e.g. high fecundity, small eggs) regularly co‐occurred with salmonids over extensive areas, sometimes over long periods, occasionally where salmonid densities were high. In contrast, galaxiid species with ‘slow’ life‐history traits (e.g. low fecundity, large eggs) were almost never found co‐occurring with salmonids, and evidence suggested they were most often excluded even where salmonid densities were low. The model outputs indicated that, although habitat played an important role, galaxiid life histories were a dominant factor determining whether species co‐occurred with or were excluded by salmonids.

The strong influence of interspecific life‐history variation on how these closely related galaxiid species interact with salmonids demonstrates the importance of detailed life‐history information in predicting how native biota are likely to respond to pressures from invasive species.
Reconsideration of the clinical and histopathological significance of angiogenesis in prostate cancer: Usefulness and limitations of microvessel density measurement
Authors: Miyata Yasuyoshi , Sakai Hideki
Published: July 2015

Angiogenesis plays important roles in tumor growth and cancer cell dissemination in almost all cancers. In prostate cancer, there is general agreement that increased angiogenesis is an important factor in determining tumor development and prognosis in these patients. Microvessel density is recognized as a useful marker for evaluating the angiogenic status of cancer tissues. Many investigators have reported that microvessel density is significantly associated with pathological features and outcomes in prostate cancer patients; however, some researchers have expressed opposing opinions. As the reason for such discrepancy, previous reports have suggested differences in the methodologies of measuring microvessel density in cancer tissues. In the present review, we focus on the variation in such methods, including the selected area and the method used for (semi)quantification. In particular, we discuss the relationship between malignancy potential, tumor progression, and survival and differences in the antibodies used for detection of endothelial cells in detail. We briefly compare the pathological significance and prognostic roles of microvessel density measured using von Willebrand factor, CD31, CD34, and CD105. Based on these analyses, the advantages and limitations of microvessel density measurements in prostate cancer tissues are clarified. Improved “real” and “specific” markers of cancer‐related angiogenesis are necessary for better predictions of prognoses and for discussion of treatment strategies for patients with prostate cancer. However, establishment of a satisfactory cancer‐related endothelial marker could take a long time. Therefore, knowledge regarding the pathological significance of microvessel density – based on understanding of the advantages and limitations of microvessel density determination methods – is important.
Three amino acid residues of an odorant‐binding protein are involved in binding odours in Loxostege sticticalis L.
Authors: Yin J. , Zhuang X. , Wang Q. , Cao Y. , Zhang S. , Xiao C. , Li K.
Published: July 2015

Odorant‐binding proteins (OBPs) play an important role in insect olfactory processes and are thought to be responsible for the transport of pheromones and other semiochemicals across the sensillum lymph to the olfactory receptors within the antennal sensilla. As an important general odorant binding protein in the process of olfactory recognition, LstiGOBP1 of Loxostege sticticalis L. has been shown to have good affinity to various plant volatiles. However, the binding specificity of LstiGOBP1 should be further explored in order to better understand the olfactory recognition mechanism of L. sticticalis. In this study, real‐time PCR experiments indicated that LstiGOBP1 was expressed primarily in adult antennae. Homology modelling and molecular docking were then conducted on the interactions between LstiGOBP1 and 1‐heptanol to understand the interactions between LstiGOBP1 and their ligands. Hydrogen bonds formed by amino acid residues might be crucial for the ligand‐binding specificity on molecular docking, a hypothesis that was tested by site‐directed mutagenesis. As predicted binding sites for LstiGOBP1, Thr15, Trp43 and Val14 were replaced by alanine to determine the changes in binding affinity. Finally, fluorescence assays revealed that the mutants Thr15 and Trp43 had significantly decreased binding affinity to most odours; in mutants that had two‐site mutations, the binding to the six odours that were tested was completely abolished. This result indicates that Thr15 and Trp43 were involved in binding these compounds, possibly by forming multiple hydrogen bonds with the functional groups of the ligands. These results provide new insights into the detailed chemistry of odours’ interactions with proteins.
On Goodness of Fit for Operational Risk
Authors: Feuerverger Andrey
Published: July 2015

The Advanced Measurement Approach (AMA) to operational risk, as described by the Basel Committee on Banking Supervision (), provides a framework meant to be used by banks for establishing the capital required to be set aside to cover worst‐case operational loss scenarios. The problems raised by an AMA approach are primarily statistical in nature, and many lie at the frontier of statistical research. The aim of this paper is to contribute to one of the more pressing challenges of an AMA, namely that of testing the goodness of fit (GoF) of a distributional family to operational loss data. Our focus is on extending certain classically known tests, such as that of Anderson–Darling, with particular emphasis on the right tails of the distributions. The nature of such GoF tests is examined in detail, and computational efficiency of the procedures is taken into account. We also propose a novel saddlepoint approximation method for assessing the asymptotic null distributions of the test statistics based on the eigenvalues of covariance kernels estimated via a jackknife and influence function‐based approach.
The impact of dental caries on children and young people: what they have to say?
Authors: Gilchrist Fiona , Marshman Zoe , Deery Chris , Rodd Helen D.
Published: July 2015

Background

Dental caries affects 60–90% of children across the world and is associated with a variety of negative impacts. Despite its ubiquity, there has been surprisingly little exploration of these impacts from the child's perspective.

Aim

The aim was to allow children to describe the impact of dental caries on their daily lives and to describe the terminology they used.

Design

Children, aged 5–15 years, with caries experience were purposively sampled from primary and secondary care dental clinics. Focus groups (n = 5) and in‐depth interviews (n = 16) were recorded and transcribed verbatim. Data analysis took a narrative approach, and themes were derived from the data using framework analysis.

Results

Pain was the main theme to emerge. Within this, three subthemes were identified: impacts related to pain, strategies adopted to reduce pain, and emotional aspects resulting from pain. A second theme was also identified relating to the aesthetic aspects of caries.

Conclusion

Children as young as 5 years of age were able to competently discuss their experiences of dental caries. Participants reported a number of impacts affecting various aspects of their lives. These will be incorporated into the future development of a caries‐specific measure of oral health‐related quality of life.
A Novel Hot Pressing Flowing Sintering for Preparation of Texturing Ceramics
Authors: Jiang Qiang‐Guo , Liu Jian , Guo Wei‐Ming , Liu Wei , Cheng Li‐Xia , Gong Man‐Feng , Wu Shang‐Hua
Published: July 2015

In this paper, we proposed a novel hot‐pressing flowing sintering (HPFS) for texturing ceramics. The perfectly two‐dimensional textured Si3N4 ceramics were fabricated by HPFS. The Lotgering orientation factor fL for Si3N4 texture was 0.9975. During earlier sintering stage, the specimen flowed along the plane which perpendicular to the hot‐pressing direction under pressure, through the controlling of the graphite die movement. The rod‐like β‐Si3N4 nuclei was easily to texture during the flowing process, due to the small size of the β‐Si3N4 nuclei and the high porosity of the flowing specimen. As a result, the perfectly two‐dimensional textured Si3N4 was obtained. After aligned, the β‐Si3N4 grains grew along the materials flowing direction with little constraint, which accelerated the growth of the grains extensively. So, in addition to texture, the Si3N4 ceramics by HPFS also showed high aspect ratio. The present study indicated that the HPFS would be more simple and low‐cost method for texture of Si3N4, compared with conventional hot‐forging which contained the sintering and forging.
Grain Orientation and Domain Configuration in 3‐1 Type Porous PZT Ceramics with Ultrahigh Piezoelectric Properties
Authors: Xu Tingting , Wang Chang‐An
Published: July 2015

Lead zirconate titanate (PZT) ceramics with one‐dimensional ordered pore channel structure (3‐1 type porous PZT ceramics) were prepared by a freeze‐casting process. Interestingly they showed higher piezoelectric coefficients than those of porous PZT ceramics of other connectivity patterns and even corresponding dense ceramics. The presence of unidirectional porosity, formed by sublimation of directional freezing solvent, markedly affects the microstructure, including grain orientation and domain configuration. XRD patterns of different sections indicated the presence of partially preferred grain growth. Grains along the through‐pore channel direction (crystal growth direction of frozen solvent) were preferentially [002]‐oriented. The porosity caused the reduction of domain size in unpolarized porous ceramics, and then the rise of the polarization rotation in poled ones. Both the oriented grain growth and small domain size enhanced the piezoelectric responses of 3‐1 type porous PZT ceramics. From the structural description, including grain orientation and domain configuration, this work provides two direct evidences for the origin of the ultrahigh piezoelectric properties in 3‐1 type porous PZT ceramics.
CdS Quantum Dot‐Sensitized Vertical TiO2 Nanorod Arrays by a Simple Linker‐Assisted SILAR Method
Authors: Wei Lidong , Li Fen , Hu Sujuan , Li Haijin , Chi Bo , Pu Jian , Jian Li
Published: July 2015

The homogeneously deposition of quantum dots (QDs) on the mesoporous or one‐dimensional TiO2 film with a well‐covered layer has become one major challenge in quantum dot‐sensitized solar cell (QDSSC). In this study, one‐dimensional TiO2 nanorod arrays based photoanode prepared by a simple linker‐assisted SILAR method is studied. The influence of the short organic ligand (TGA) on the homogeneity of QDs on TiO2 nanorod arrays is discussed and the photoelectrochemical performance of QDSSC is evaluated by UV–vis absorbance spectroscopy, current–voltage performance and electrochemical impedance spectroscopy. The results show that the TGA ligand can act as an efficient bridge between CdS QDs and TiO2, whereas the content and particle size of the QDs can be easily tuned by controlling the dipping time and SILAR cycle. Owing to the presence of TGA, the charge‐transfer rate at CdS QDs and TiO2 interfacial region is noticeable enhanced.
Electrical and Thermal Conduction Behaviors in La‐Substituted GdBaCuFeO5+δ Ceramics
Authors: Zeng Chengcheng , Zhan Bin , Butt Sajid , Liu Yaochun , Ren Guangkun , Lin Yuan‐Hua , Li Ming , Nan Ce‐Wen
Published: July 2015

Gd1−xLaxBaCuFeO5+δ polycrystalline ceramics have been prepared by a sol–gel method combined with the traditional ceramic processing. Analysis of the microstructure and phase composition reveals that the pure GdBaCuFeO5+δ phase can be obtained even after the substitution of 50% La at Gd‐site. The band gap can be tuned from 1.47 to 1.36 eV by La substitution, resulting in a significant increase in the electrical conductivity. In addition, the total thermal conductivity can also be suppressed by the substitution of La at Gd‐sites. A ZT value of 0.02 at 1023 K is achieved in the 50% La‐substituted samples, which is over 20 times higher than that of the pure GdBaCuFeO5+δ sample.
The Microstructure and Dielectric Properties of SiBCN Ceramics Fabricated Via LPCVD/CVI
Authors: Liu Yongsheng , Chai Nan , Liu Xiaofei , Qin Hailong , Yin Xiaowei , Zhang Litong , Cheng Laifei
Published: July 2015

Low‐pressure chemical vapor deposition and infiltration was used for the first time to fabricate SiBCN ceramics with proper dielectric properties to lower the preparation temperature. SiBCN ceramics indicated by thermodynamic phase diagram with different phase compositions from CH3SiCl3–NH3–BCl3‐H2 could be obtained through adjustable parameters. The as‐prepared SiBCN ceramics fabricated above 900°C showed proper dielectric properties with dielectric loss of about 0.1, which was due to the generation of amorphous carbon and SiC nanocrystals.
Compilation and Evaluation of the Pressure‐Assisted Master Sintering Surface for Low‐Temperature Cofired Ceramics
Authors: Brandt Bjoern , Rabe Torsten
Published: July 2015

Pressure‐assisted sintering (PAS) is an established procedure for the production of low‐temperature cofired ceramics (LTCC) without lateral shrinkage and minimal shrinkage tolerances for automotive and high‐frequency applications. To develop a feasible model for the prediction of densification during that process, master sintering curves (MSCs) for the commercial LTCC DP951 were generated from thermomechanical analysis (TMA) data in the pressure regime from 2 to 500 kPa. Strain mainly related to creep deformation of the LTCC was identified by evaluation of the strain rate and was discarded for the determination of MSC parameters. It was found that no creep occurred at any pressure up to a relative density of 0.9. Different pressure levels can be modeled with the same activation energy of 400 kJ/mol. Densification curves predicted by the model were in good agreement with experimental data. Based on MSCs, the pressure‐assisted master sintering surface was compiled to illustrate the influence of pressure on densification. The results show that the MSC approach is a suitable method to feasibly predict the densification of LTCC during PAS.
A Novel Top‐Seeded Infiltration Growth Technique for Fabricating Y–Ba–Cu–O Single‐Grain Superconductor Nano‐Composites
Authors: Li Guo‐Zheng , Dong Lei , Deng Xiang‐Yun
Published: July 2015

Top‐seed infiltration and growth technique (TSIG) is proposed to fabricate Y–Ba–Cu–O (YBCO) single‐grain superconductor nano‐composites, in which a solid source composition of nano‐Y2O3 + BaCuO2 and a liquid source composition of Y2O3 + 10BaO + 16CuO are employed. As can be seen, this novel technique uses just one source of precursor powder of BaCuO2, so it is more simplified and efficient. Microstructural observation indicates that fine Y2BaCuO5 (Y‐211) inclusions with a size from dozens of nanometers to about one hundred nanometers are successfully introduced in YBa2Cu3O7−x (Y‐123) superconducting matrix, which can act as more effective pinning centers for improving the bulk performance. Superconducting property measurement shows that, a maximum trapped field of 0.36044 T is present at the center of the sample after magnetization by a permanent magnet (B = 0.5 T). These results prove that our proposed TSIG technique is a practical method for fabricating YBCO bulk superconductor nano‐composites with high performance.
Insights into High‐Temperature Uniaxial Compression Deformation Behavior of Ti3AlC2
Authors: Zhang Hui , Wang Xiaohui , Wan Peng , Zhan Xun , Zhou Yanchun
Published: July 2015

We report on strain‐rate‐dependent compression deformation behavior of Ti3AlC2 at 1000°C–1200°C. At 1000°C and high strain rate (10−2 or 10−3 s−1), Ti3AlC2 deforms in a nonplastic manner. Upon increasing temperature and reducing strain rate, Ti3AlC2 exhibits a limited plasticity. For instance, the true plastic strain at 1200°C and 10−4 s−1 is only 3%, beyond which strain softening following a short hardening regime occurs. The softening results from the formation of localized microvoids and microcracks. Decreasing the strain rate further to 10−5 s−1 at 1200°C, strain hardening instead of softening is identified. Under such conditions, the plastic strain remarkably increases, reaching a value as high as 27%. Postdeformation microstructural analyses of the dislocation configurations explicitly evidence the dislocation reactions, formation of hexagonal dislocation networks and dislocation entanglements. These account for the strain hardening. The extraordinary plasticity at 1200°C and 10−5 s−1 benefits from the initiation of nonbasal slip systems. Finally, a complete high‐temperature deformation scenario for nanolaminated Ti3AlC2 is elaborated.
Climatic, vegetation and edaphic influences on the probability of fire across mediterranean woodlands of south‐eastern Australia
Authors: Gibson Rebecca K. , Bradstock Ross A. , Penman Trent , Keith David A. , Driscoll Don A.
Published: July 2015

Aim

We investigated how the probability of burning is influenced by the time since fire (TSF) and gradients of climate, soil and vegetation in the fire‐prone mediterranean‐climate mallee woodlands of south‐eastern Australia. This provided insight into the processes controlling contemporary fuel dynamics and fire regimes across biogeographical boundaries, and the consequent effects of climate change on potential shifts in boundaries between fuel systems and fire regimes, at a subcontinental scale.

Location

South‐eastern Australia.

Methods

A desktop‐based GIS was used to generate random sampling points across the study region to collect data on intersecting fire interval, rainfall, vegetation and soil type. We used a Bayesian framework to examine the effects of combinations of rainfall, vegetation and soil type on the hazard‐of‐burning and survival parameters of the Weibull distribution. These analyses identify the nature of environmental controls on the length of fire intervals and the age‐dependence of the hazard of burning.

Results

Higher rainfall was consistently associated with shorter fire intervals. Within a single level of rainfall, however, the interaction between soil and vegetation type influenced the length of fire intervals. Higher‐fertility sands were associated with shorter fire intervals in grass‐dominated communities, whereas lower‐fertility sands were associated with shorter fire intervals in shrub‐dominated communities. The hazard of burning remained largely independent of TSF across the region, only markedly increasing with TSF in shrub‐dominated communities at high rainfall.

Main conclusions

Rainfall had a dominant influence on fire frequency in the mediterranean‐climate mallee woodlands of south‐eastern Australia. Predicted changes in the spatial distribution and amount of rainfall therefore have the potential to drive changes in fire regimes, although the effects of soil fertility and rainfall on fire regimes do not align on a simple productivity gradient. Reduced soil fertility may favour plant traits that increase the rate of woody litter fuel accumulation and flammability, which may alter the overriding influence of rainfall gradients on fire regimes.
Pinus nigra (European black pine) as the dominant species of the last glacial pinewoods in south‐western to central Iberia: a morphological study of modern and fossil pollen
Authors: Desprat Stéphanie , Díaz Fernández Pedro Manuel , Coulon Tabatha , Ezzat Leila , Pessarossi‐Langlois Julien , Gil Luis , Morales‐Molino César , Sánchez Goñi Maria Fernanda
Published: July 2015

Aim

Our aim was to discriminate different species of Pinus via pollen analysis in order to assess the responses of particular pine species to orbital and millennial‐scale climate changes, particularly during the last glacial period.

Location

Modern pollen grains were collected from current pine populations along transects from the Pyrenees to southern Iberia and the Balearic Islands. Fossil pine pollen was recovered from the south‐western Iberian margin core MD95‐2042.

Methods

We measured a set of morphological traits of modern pollen from the Iberian pine species Pinus nigra, P. sylvestris, P. halepensis, P. pinea and P. pinaster and of fossil pine pollen from selected samples of the last glacial period and the early to mid‐Holocene. Classification and regression tree (CART) analysis was used to establish a model from the modern dataset that discriminates pollen from the different pine species and allows identification of fossil pine pollen at the species level.

Results

The CART model was effective in separating pollen of P. nigra and P. sylvestris from that of the Mediterranean pine group (P. halepensis, P. pinea and P. pinaster). The pollen of Pinus nigra diverged from that of P. sylvestris by having a more flattened corpus. Predictions using this model suggested that fossil pine pollen is mainly from P. nigra in all the samples analysed. Pinus sylvestris was more abundant in samples from Greenland stadials than Heinrich stadials, whereas Mediterranean pines increased in samples from Greenland interstadials and during the early to mid‐Holocene.

Main conclusions

Morphological parameters can be successfully used to increase the taxonomic resolution of fossil pine pollen at the species level for the highland pines (P. nigra and P. sylvestris) and at the group of species level for the Mediterranean pines. Our study indicates that P. nigra was the dominant component of the last glacial south‐western/central Iberian pinewoods, although the species composition of these woodlands varied in response to abrupt climate changes.
Functional abnormalities in iPSC‐derived cardiomyocytes generated from CPVT1 and CPVT2 patients carrying ryanodine or calsequestrin mutations
Authors: Novak Atara , Barad Lili , Lorber Avraham , Gherghiceanu Mihaela , Reiter Irina , Eisen Binyamin , Eldor Liron , Itskovitz‐Eldor Joseph , Eldar Michael , Arad Michael , Binah Ofer
Published: July 2015

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmia characterized by syncope and sudden death occurring during exercise or acute emotion. CPVT is caused by abnormal intracellular Ca2+ handling resulting from mutations in the RyR2 or CASQ2 genes. Because CASQ2 and RyR2 are involved in different aspects of the excitation‐contraction coupling process, we hypothesized that these mutations are associated with different functional and intracellular Ca²+ abnormalities. To test the hypothesis we generated induced Pluripotent Stem Cell‐derived cardiomyocytes (iPSC‐CM) from CPVT1 and CPVT2 patients carrying the RyR2R420Q and CASQ2D307H mutations, respectively, and investigated in CPVT1 and CPVT2 iPSC‐CM (compared to control): (i) The ultrastructural features; (ii) the effects of isoproterenol, caffeine and ryanodine on the [Ca2+]i transient characteristics. Our major findings were: (i) Ultrastructurally, CASQ2 and RyR2 mutated cardiomyocytes were less developed than control cardiomyocytes. (ii) While in control iPSC‐CM isoproterenol caused positive inotropic and lusitropic effects, in the mutated cardiomyocytes isoproterenol was either ineffective, caused arrhythmias, or markedly increased diastolic [Ca2+]i. Importantly, positive inotropic and lusitropic effects were not induced in mutated cardiomyocytes. (iii) The effects of caffeine and ryanodine in mutated cardiomyocytes differed from control cardiomyocytes. Our results show that iPSC‐CM are useful for investigating the similarities/differences in the pathophysiological consequences of RyR2 versus CASQ2 mutations underlying CPVT1 and CPVT2 syndromes.
A novel TXNIP‐based mechanism for Cx43‐mediated regulation of oxidative drug injury
Authors: Gao Kun , Chi Yuan , Zhang Xiling , Zhang Hui , Li Gang , Sun Wei , Takeda Masayuki , Yao Jian
Published: July 2015

Gap junctions (GJs) play an important role in the regulation of cell response to many drugs. However, little is known about their mechanisms. Using an in vitro model of cytotoxicity induced by geneticin (G418), we explored the potential signalling mechanisms involved. Incubation of cells with G418 resulted in cell death, as indicated by the change in cell morphology, loss of cell viability and activation of caspase‐3. Before the onset of cell injury, G418 induced reactive oxygen species (ROS) generation, activated oxidative sensitive kinase P38 and caused a shift of connexin 43 (Cx43) from non‐phosphorylated form to hyperphosphorylated form. These changes were largely prevented by antioxidants, suggesting an implication of oxidative stress. Downregulation of Cx43 with inhibitors or siRNA suppressed the expression of thioredoxin‐interacting protein (TXNIP), activated Akt and protected cells against the toxicity of G418. Further analysis revealed that inhibition of TXNIP with siRNA activated Akt and reproduced the protective effect of Cx43‐inhibiting agents, whereas suppression of Akt sensitized cells to the toxicity of G418. Furthermore, interference of TXNIP/Akt also affected puromycin‐ and adriamycin‐induced cell injury. Our study thus characterized TXNIP as a presently unrecognized molecule implicated in the regulatory actions of Cx43 on oxidative drug injury. Targeting Cx43/TXNIP/Akt signalling cascade might be a promising approach to modulate cell response to drugs.
Ginsenoside Rg1 improves bone marrow haematopoietic activity via extramedullary haematopoiesis of the spleen
Authors: Liu Hua‐Hsing , Chen Fei‐Peng , Liu Rong‐Kai , Lin Chun‐Lin , Chang Ko‐Tung
Published: July 2015

Cyclophosphamide (CY) is a chemotherapeutic agent used for cancer and immunological diseases. It induces cytotoxicity of bone marrow and causes myelosuppression and extramedullary haematopoiesis (EMH) in treated patients. EMH is characterized with the emergence of multipotent haematopoietic progenitors most likely in the spleen and liver. Previous studies indicated that a Chinese medicine, ginsenoside Rg1, confers a significant effect to elevate the number of lineage (Lin−) Sca‐1+ c‐Kit+ haematopoietic stem and progenitor cells (HSPCs) and restore the function of bone marrow in CY‐treated myelosuppressed mice. However, whether the amelioration of bone marrow by Rg1 accompanies an alleviation of EMH in the spleen was still unknown. In our study, the cellularity and weight of the spleen were significantly reduced after Rg1 treatment in CY‐treated mice. Moreover, the number of c‐Kit+ HSPCs was significantly decreased but not as a result of apoptosis, indicating that Rg1 alleviated EMH of the spleen induced by CY. Unexpectedly, the proliferation activity of c‐Kit+ HSPCs was only up‐regulated in the spleen, but not in the bone marrow, after Rg1 treatment in CY‐treated mice. We also found that a fraction of c‐Kit+/CD45+ HSPCs was simultaneously increased in the circulation after Rg1 treatment. Interestingly, the effects of Rg1 on the elevation of HSPCs in bone marrow and in the peripheral blood were suppressed in CY‐treated splenectomized mice. These results demonstrated that Rg1 improves myelosuppression induced by CY through its action on the proliferation of HSPCs in EMH of the spleen and migration of HSPCs from the spleen to the bone marrow.
Buprenorphine‐elicited alteration of adenylate cyclase activity in human embryonic kidney 293 cells coexpressing κ‐, μ‐opioid and nociceptin receptors
Authors: Wang Pei‐Chen , Ho Ing‐Kang , Lee Cynthia Wei‐Sheng
Published: July 2015

Buprenorphine, a maintenance drug for heroin addicts, exerts its pharmacological function via κ‐ (KOP), μ‐opioid (MOP) and nociceptin/opioid receptor‐like 1 (NOP) receptors. Previously, we investigated its effects in an in vitro model expressing human MOP and NOP receptors individually or simultaneously (MOP, NOP, and MOP+NOP) in human embryonic kidney 293 cells. Here, we expanded this cell model by expressing human KOP, MOP and NOP receptors individually or simultaneously (KOP, KOP+MOP, KOP+NOP and KOP+MOP+NOP). Radioligand binding with tritium‐labelled diprenorphine confirmed the expression of KOP receptors. Immunoblotting and immunocytochemistry indicated that the expressed KOP, MOP and NOP receptors are N‐linked glycoproteins and colocalized in cytoplasmic compartments. Acute application of the opioid receptor agonists— U‐69593, DAMGO and nociceptin— inhibited adenylate cyclase (AC) activity in cells expressing KOP, MOP and NOP receptors respectively. Buprenorphine, when applied acutely, inhibited AC activity to ~90% in cells expressing KOP+MOP+NOP receptors. Chronic exposure to buprenorphine induced concentration‐dependent AC superactivation in cells expressing KOP+NOP receptors, and the level of this superactivation was even higher in KOP+MOP+NOP‐expressing cells. Our study demonstrated that MOP receptor could enhance AC regulation in the presence of coexpressed KOP and NOP receptors, and NOP receptor is essential for concentration‐dependent AC superactivation elicited by chronic buprenorphine exposure.
Role of exosomes and microvesicles in hypoxia‐associated tumour development and cardiovascular disease
Authors: Belting M. , Christianson H. C.
Published: July 2015

Exosomes and microvesicles, collectively referred to as extracellular vesicles (EVs), can transfer complex biological information and induce a diverse signalling response in recipient cells with potential relevance in a wide array of pathological conditions. Tissue hypoxia constitutes a stress‐associated phenotype that is central to the malignant state of aggressive tumours as well as to ischaemic tissue in cardiovascular disorders. The adaptive response to hypoxic stress is largely dependent on intercellular communication in which EVs, and cellular exchange of EV cargo molecules, have recently been implicated. The results of numerous studies indicate that hypoxia‐dependent shaping of the molecular profile of EVs may mediate the biological response to hypoxia. EVs have been shown to induce tumour angiogenesis and hypercoagulation as well as tissue remodelling and protective effects in ischaemic cardiovascular conditions. Recent findings report increased levels of circulating EVs in patients with hypoxia‐associated disorders such as myocardial infarction, stroke and pre‐eclampsia, indicating a role of EVs as biomarkers in these pathophysiological states. Here, we discuss the intriguing role of EVs in tumour development and cardiovascular disease, focusing on the paracrine transfer of the hypoxic response to neighbouring cells and to distant cells at the systemic level, with wide implications for biomarker discovery and therapeutic intervention.
Variation in plant thermal reaction norms along a latitudinal gradient – more than adaptation to season length
Authors: Toftegaard Tenna , Posledovich Diana , Navarro‐Cano José A. , Wiklund Christer , Gotthard Karl , Ehrlén Johan
Published: July 2015

Little is known about the extent to which observed phenological responses to changes in climate are the result of phenotypic plasticity or genetic changes. We also know little about how plasticity, in terms of thermal reaction norms, vary spatially. We investigated if the thermal reaction norms for flower development of five crucifer species (Brassicaceae) differed among three regions along a south–north latitudinal gradient in replicated experiments. The mean response (elevation) of thermal reaction norms of flowering differed among regions in all study species, while sensitivity of flower development to temperature (slope) differed in only one of the species. Differences in mean responses corresponded to cogradient patterns in some species, but countergradient patterns in other. This suggests that differences among regions were not solely the result of adaptation to differences in the length of the growing season, but that other factors, such as herbivory, play an important role. Differences in development rate within species were mainly explained by variation in early phases of bud formation in some species but by variation in later phases of bud formation in other species. The differences in latitudinal patterns of thermal reaction norms among species observed in this study are important, both to identify agents of selection and to predict short‐ and long‐term responses to a warming climate.