bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of biochar amendment on soil‐silicon availability and rice uptake
Authors: Liu Xiaoyu , Li Lianqing , Bian Rongjun , Chen De , Qu Jingjing , Wanjiru Kibue Grace , Pan Genxing , Zhang Xuhui , Zheng Jinwei , Zheng Jufeng
Published: February 2014

Rice growth and its resistance to pests had been often constrained by soil‐silicon (Si) availability. The purpose of this study was to assess the potential of biochar soil amendment (BSA) to improve Si availability in paddy soils. A cross‐site field trail with BSA was conducted in six locations with different climatic and crop‐production conditions across S China. Plant‐available Si content before field‐trials establishment and after rice harvest, as well as Si content in rice shoot were determined. Varying with site conditions, plant‐available Si content of soil was observed to increase significantly with BSA in most sites. Significant increase in rice shoot Si was detected in four out of the six sites, which was well correlated to the concurrent increase in soil pH under BSA treatment. This study demonstrates an important role of BSA to improve Si availability and uptake by rice mainly through increasing soil pH of the acid and slightly acid rice soils.
Effect of methyl jasmonate, sodium selenate and chitosan as exogenous elicitors on the phenolic compounds profile of broccoli sprouts
Authors: Barrientos Carvacho Herna , Pérez Carmen , Zúñiga Gustavo , Mahn Andrea
Published: February 2014

BACKGROUND

Broccoli sprouts are a good source of secondary metabolites, exhibiting biological activity, such as polyphenols, whose concentration is affected by the exposure to exogenous elicitors. The aim of this work was to investigate the effect of sodium selenate, chitosan and methyl jasmonate, applied directly to the seeds or through irrigation, on the content and profile of phenolic compounds in broccoli sprouts. The effect on antioxidant activity was also investigated.

RESULTS

Methyl jasmonate and chitosan decreased antioxidant capacity. Methyl jasmonate significantly decreased total polyphenols content in comparison with control sprouts, while chitosan significantly increased it. Sodium selenate had no statistical effect on antioxidant capacity and total polyphenols concentration. The polyphenols profile in sprouts was composed by quercetin, morine, genisteine, luteoline and sinapic acid. Elicitor type and concentration affected the synthesis of these compounds. Chitosan stimulated the synthesis of quercetin, sinapic acid and morine, whereas methyl jasmonate stimulated the synthesis of luteoline. Sodium selenate had no effect on polyphenols synthesis.

CONCLUSION

The exposure of broccoli to the elicitors produced changes in the phenolic compounds profile of broccoli sprouts. Besides, the stimulation of phenolic compounds synthesis was elicitor‐specific, thus opening the possibility of managing culture conditions to increase the content of a specific phenolic compound. © 2014 Society of Chemical Industry
Macrocyclic polyamine‐functionalized silica as a solid‐phase extraction material coupled with ionic liquid dispersive liquid–liquid extraction for the enrichment of polycyclic aromatic hydrocarbons
Authors: Liu Longhui , He Lijun , Jiang Xiuming , Zhao Wenjie , Xiang Guoqiang , Anderson Jared L.
Published: February 2014

In this study, silica modified with a 30‐membered macrocyclic polyamine was synthesized and first used as an adsorbent material in SPE. The SPE was further combined with ionic liquid (IL) dispersive liquid–liquid microextraction (DLLME). Five polycyclic aromatic hydrocarbons were employed as model analytes to evaluate the extraction procedure and were determined by HPLC combined with UV/Vis detection. Acetone was used as the elution solvent in SPE as well as the dispersive solvent in DLLME. The enrichment of analytes was achieved using the 1,3‐dibutylimidazolium bis[(trifluoromethyl)sulfonyl]imide IL/acetone/water system. Experimental conditions for the overall macrocycle‐SPE–IL‐DLLME method, such as the amount of adsorbent, sample solution volume, sample solution pH, type of elution solvent as well as addition of salt, were studied and optimized. The developed method could be successfully applied to the analysis of four real water samples. The macrocyclic polyamine offered higher extraction efficiency for analytes compared with commercially available C18 cartridge, and the developed method provided higher enrichment factors (2768–5409) for model analytes compared with the single DLLME. Good linearity with the correlation coefficients ranging from 0.9983 to 0.9999 and LODs as low as 0.002 μg/L were obtained in the proposed method.
A Case Study on Culture Brokers and Their Role in Tourism Management in the Indigenous Community of Taquile Island in Puno, Peru
Authors: Cherro Osorio Sandra Guisela , Best Gary
Published: February 2014

This study examines the role of culture brokers in the management of tourism in the indigenous community of Taquile Island. Culture brokers are individuals that have the ability to understand visitors' culture as well as their own. In‐depth interviews were conducted with culture brokers, members of the community and tourists to explore the topic from multiple perspectives. The findings suggest that their strong sense of identity has determined that culture brokers direct the course of action from inside and outside their society, while members of the community contribute from their positions, and this collaborative effort positively influences the tourist experience. Copyright © 2014 John Wiley & Sons, Ltd.
Mapping the Morphology of Polymer–Inorganic Nanocomposites Synthesized by Miniemulsion Polymerization
Authors: Asua José M.
Published: February 2014

A first‐principles map for the equilibrium morphologies of polymer–inorganic nanocomposites synthesized by miniemulsion polymerization is developed. The predictions are compared with literature results on the effect of the initiator type, surfactant concentration, monomer system, and surface characteristics of the inorganic nanoparticles on the morphology of the nanocomposites. The limitations of the morphology map are also discussed.

image
Cofinalities of Borel ideals
Authors: Hrušák Michael , Rojas‐Rebolledo Diego , Zapletal Jindřich
Published: February 2014

We study the possible values of the cofinality invariant for various Borel ideals on the natural numbers. We introduce the notions of a fragmented and gradually fragmented ideal and prove a dichotomy for fragmented ideals. We show that every gradually fragmented ideal has cofinality consistently strictly smaller than the cardinal invariant and produce a model where there are uncountably many pairwise distinct cofinalities of gradually fragmented ideals.
Some integral‐type operators from spaces to mixed‐norm spaces on the unit ball
Authors: Liang Yu‐Xia , Zhou Ze‐Hua
Published: February 2014

We discuss the boundedness and compactness of some integral‐type operators acting from spaces to mixed‐norm spaces on the unit ball of .
Suppressing Instability of Liquid Thin Films by a Fibril Network and its Application to Micropatterning without a Residual Layer
Authors: Park Jaeyoon , Park Minwoo , Jeong Unyong
Published: February 2014

This study proposes a method to coat thin films of non‐volatile solvents on substrates. A small amount of crystalline polymer dissolved in solvents forms a network of crystalline fibrils during the coating process. The network suppresses dewetting of the solvent liquid and helps the liquid film sustaining on the substrate. This strategy can be used in soft lithography to generate micropatterns of diverse materials without having a residual layer. This process does not request etching for achieving residual layer‐free micropatterns, which has been a long challenge in soft lithography. As examples, we demonstrate micropatterns of polymer hydrogels and metal oxides (ZnO, In2O3

image
Stimuli‐Triggered Growth and Removal of a Bioreducible Nanoshell on Nanoparticles
Authors: Han Li‐Fen , Chen Qian‐Bao , Hu Zong‐Tao , Piao Jia‐Gang , Hong Chun‐Yan , Yan Jun‐Jie , You Ye‐Zi
Published: February 2014

A new and easy method of stimuli‐triggered growth and removal of a bioreducible nanoshell on nanoparticles is reported. The results show that pH or temperature could induce the aggregation of disulfide‐contained branched polymers at the surface of nanoparticles; subsequently, the aggregated polymers could undergo intermolecular disulfide exchange to cross‐link the aggregated polymers, forming a bioreducible polymer shell around nanoparticles. When these nanoparticles with a polymer shell are treated with glutathione (GSH) or d,l‐dithiothreitol (DTT), the polymer shell could be easily removed from the nanoparticles. The potential application of this method is demonstrated by easily growing and removing a bioreducible shell from liposomes, and improvement of in vivo gene transfection activity of liposomes with a bioreducible PEG shell.

image
Spin Thermoelectric Properties of Polythiophene Molecular Junction
Authors: Golsanamlou Zahra , Tagani Meysam Bagheri , Soleimani Hamid Rahimpour
Published: February 2014

Spin thermoelectric properties of different lengths of polythiophene in molecular junction are investigated using Green function in linear response regime. An extended Su‐Schrieffer‐Heeger model is used to describe the Hamiltonian of the molecule. The coupling of molecular chain to three‐dimensional ferromagnetic electrodes is studied by a tight‐binding model for both parallel and antiparallel configurations. The decrease of HOMO‐LUMO gap and magnetothermopower and increase of oscillation of the spin thermopower and spin figure of merit are the most important phenomena observed by increasing the molecular length. In addition, results show that the spin thermoelectric coefficients are strongly related to the integral exchange energy.
A prey–predator interaction under fluctuating level water
Authors: Moussaoui A. , Bouguima S.M.
Published: February 2014

We consider three species system, namely prey (roach), predator (pike) and plankton. We derive persistence and extinction conditions of the populations. Using coincidence degree theory, we determine conditions for which the system has a periodic solution. Copyright © 2014 John Wiley & Sons, Ltd.
Strong solutions to an Oldroyd‐B model with slip boundary conditions via incompressible limit
Authors: Ren Dandan , Ou Yaobin
Published: February 2014

In this paper, we establish the local existence of strong solutions to an Oldroyd‐B model for the incompressible viscoelastic fluids in a bounded domain , via the incompressible limit. The main idea is to derive the uniform estimates with respect to the Mach number for the linearized system of compressible Oldroyd equations. Copyright © 2014 John Wiley & Sons, Ltd.
Motor activity at age one year does not predict ADHD at seven years
Authors: Johnson Paul , Ahamat Boolang , Mcconnachie Alex , Puckering Christine , Marwick Helen , Furnivall Daniel , Marwick Robbie , Gillberg Christopher , Heron Jon , Wilson Philip
Published: February 2014

We have examined the predictive utility of motor activity in infancy towards diagnosis of attention deficit hyperactivity disorder (ADHD) in later childhood. We conducted a nested case‐control study using videos of infants in the Avon Longitudinal Study of Parents and Children (ALSPAC). Sixty videos of children who received any Development and Well‐being Assessment (DAWBA) psychiatric diagnosis at age 91 months (including 16 with ADHD) plus two controls per case were selected for data analysis. Body movements were measured at age one year: associations between motor activity‐derived variables using factor analysis, and later ADHD diagnoses were sought. No significant association was found between infant motor activity and later ADHD. A positive association between motor activity and inattentive ADHD was found in males. Motor activity at age one year did not predict ADHD at age seven years. The positive association with inattentive ADHD in males requires further investigation. Copyright © 2014 John Wiley & Sons, Ltd.
Guideline Recommendations for Post‐Acute Postoperative Physiotherapy in Total Hip and Knee Arthroplasty: Are They Used in Daily Clinical Practice?
Authors: Peter W. F. , Nelissen R. G. H. H. , Vliet Vlieland T. P. M.
Published: February 2014

Background

In a Dutch guideline on physiotherapy (PT) in hip and knee osteoarthritis, a number of recommendations on post‐acute (i.e. after discharge from hospital) PT following total hip (THA) and total knee (TKA) arthroplasty were included. Little is known about the uptake of these recommendations in daily clinical practice.

Objective

The aim of the present study was to determine the extent to which the guideline recommendations regarding post‐acute PT after THA and TKA are followed in daily clinical practice.

Methods

An online pilot survey on the delivery of post‐acute, postoperative PT was sent to a random sample of 957 Dutch physiotherapists. The survey included questions on the application of recommended, neither recommended nor advised against, and advised against treatment modalities and various treatment modalities for which there were no formulated recommendations.

Results

A total of 219 physiotherapists completed the questionnaire, with a mean age of 40 years (standard deviation 12.6), 55% female and 95% working in primary care. The vast majority reported the use of the recommended exercise modalities (muscle strengthening exercises (96%), and functional exercises (99%). Continuous passive motion, which was neither recommended nor advised against, and electrical muscle stimulation, which was not recommended, were provided by 1%. Reported treatment modalities for which there were no formulated recommendations included patient education (99%), gait training (95%), active range of motion (ROM) exercises (93%), balance exercises (86%), passive ROM exercises (58%), aerobic exercises (50%), massage (18%) and cold therapy (11%).

Conclusions

The vast majority of physiotherapists reported adhering to recommendations on post‐acute postoperative PT in THA and TKA patients after discharge from hospital. Although yet to be confirmed in a larger nationwide survey, the relatively high frequency of use of many other treatment modalities, for which there were no formulated recommendations, suggests the need to extend the current set of recommendations to include evidence‐based statements on additional treatment modalities. Copyright © 2014 John Wiley & Sons, Ltd.
Functionalized graphene/thermoplastic polyester elastomer nanocomposites by reactive extrusion‐based masterbatch: preparation and properties reinforcement
Authors: Ma Liyan , Yu Bin , Qian Xiaodong , Yang Wei , Pan Haifeng , Shi Yongqian , Song Lei , Hu Yuan
Published: February 2014

A reactive extrusion process was developed to fabricate polymer/graphene nanocomposites with good dispersion of graphene sheets in the polymer matrix. The functionalized graphene nanosheet (f‐GNS) activated by diphenylmethane diisocyanate was incorporated in thermoplastic polyester elastomer (TPEE) by reactive extrusion process to produce the TPEE/f‐GNS masterbatch. And then, the TPEE/f‐GNS nanocomposites in different ratios were prepared by masterbatch‐based melt blending. The structure and morphology of functionalized graphene were characterized by Fourier transform infrared, X‐ray photoelectron spectroscopy, X‐ray diffraction and transmission electron microscopy (TEM). The incorporation of f‐GNS significantly improved the mechanical, thermal and crystallization properties of TPEE. With the incorporation of only 0.1 wt% f‐GNS, the tensile strength and elongation at break of nanocomposites were increased by 47.6% and 30.8%, respectively, compared with those of pristine TPEE. Moreover, the degradation temperature for 10 wt% mass loss, storage modulus at −70°C and crystallization peak temperature (Tcp) of TPEE nanocomposites were consistently improved by 17°C, 7.5% and 36°C. The remarkable reinforcements in mechanical and thermal properties were attributed to the homogeneous dispersion and strong interfacial adhesion of f‐GNS in the TPEE matrix. The functionalization of graphene was beneficial to the improvement of mechanical properties because of the relatively well dispersion of graphene sheets in TPEE matrix, as suggested in the TEM images. This simple and effective approach consisting of chemical functionalization of graphene, reactive extrusion and masterbatch‐based melt blending process is believed to offer possibilities for broadening the graphene applications in the field of polymer processing. Copyright © 2014 John Wiley & Sons, Ltd.
Immune‐mediated mechanism for thrombocytopenia after Loxosceles spider bite
Authors: Levin Carina , Bonstein Lilach , Lauterbach Roy , Mader Rivka , Rozemman Dganit , Koren Ariel
Published: February 2014

Loxoscelism, characterized by high fever, vomiting, malaise, a dermonecrotic lesion, and thrombocytopenia, was diagnosed in a 3‐year‐old female. Clinical laboratory and dermatological signs are described. Blood test showed a transient hypercoagulable state and the presence of IgG antibodies against platelets, suggesting an immune‐mediated mechanism for platelet destruction, in addition to the direct toxic effect of the spider venom. The finding of platelet antibodies after a Loxosceles spider bite has not been previously reported. Pediatr Blood Cancer 2014; 61:1466–1468. © 2014 Wiley Periodicals, Inc.
Radiation synthesis and characterization of styrene/acrylic acid/organophilic montmorillonite hybrid nanocomposite for sorption of dyes from aqueous solutions
Authors: El‐Sigeny Samia , Mohamed Sahar K. , Abou Taleb Manal F.
Published: February 2014

Organophilic montmorillonite (OMMT) was synthesized by cationic exchange reaction of Na+‐MMT and vinyl benzyl triethyl ammonium chloride (VBTAC) as a reactive organic modifier in an aqueous solution. A series of styrene (St)/acrylic acid (AA)/OMMT nanocomposite hydrogel containing different wt% of OMMT was synthesized through in situ polymerization using γ‐ray. The samples were characterized using Fourier transform infrared (FTIR), X‐ray powder diffraction (XRD), and transmission electron microscope (TEM), whereas thermal stability was examined by thermogravimetric analysis (TGA). The adsorption capacity and rate for both Acid Green B (anionic) and Maxilon C.I. Basic (cationic) dye including adsorption kinetics and isotherm were investigated at 30°C. TEM measurements showed spherical nanosized particles of average diameter 30–40 nm and XRD suggested the formation of exfoliated nanocomposite. TGA measurements showed that the addition of OMMT did not enhance the thermal stability where the onset temperature of the degradation for all samples was around 125°C. The effect of some important parameters on dye adsorption such as solution pH, initial dye concentration, and contact time was investigated. The equilibrium data obtained in batch experiments were correlated to Langmuir and Freundlich isotherm equations. Results showed that the adsorption of Acid Green B fitted well to the Langmuir model while the adsorption pattern of Maxilon C.I. Basic followed the Freundlich isotherm, which suggests heterogeneity of the adsorption sites on the nanocomposite. POLYM. COMPOS., 35:2353–2364, 2014. © 2014 Society of Plastics Engineers
Electrospun polyester/cyclodextrin nanofibers for entrapment of volatile organic compounds
Authors: Kayaci Fatma , Uyar Tamer
Published: February 2014

Polyester (PET) nanofibers incorporating cyclodextrins (CD) were obtained via electrospinning. α‐CD, β‐CD, and γ‐CD were used to functionalize PET nanofibers. Bead‐free PET/CD nanofibers were obtained from lower polymer concentration indicating that the incorporation of CD in polymer solution improved the electrospinnability of the PET nanofibers. XRD studies indicated that CD were distributed into nanofiber without forming crystalline aggregates. FTIR peak shift was observed possibly due to interaction between CD and PET. TGA confirmed that initial CD loading (25%, w/w) in the polymer solution was preserved for the PET/CD nanofibers. The presence of most of CD on the surface of PET/CD nanofibers was confirmed by XPS analysis and contact angle measurement. DMA results indicated that incorporation of CD improved the mechanical property of the nanofibers. Our studies showed that PET/CD nanofibers can effectively entrap aniline vapor as a model volatile organic compound (VOC) from surrounding owing to their very large surface area and inclusion complexation capability of CD. The entrapment efficiency of aniline vapor was found to be better for PET/γ‐CD nanofibers compared to PET/α‐CD and PET/β‐CD nanofibers. Our findings suggested that electrospun PET nanofibers functionalized with CD may be used as filtering material for removal of VOC in air filtration. POLYM. ENG. SCI., 54:2970–2978, 2014. © 2014 Society of Plastics Engineers
Star polymers for gene delivery
Authors: Georgiou Theoni K
Published: February 2014

Star polymers are hyperbranched polymers with fascinating properties and exhibiting self‐assembly behaviour that have recently attracted a lot of interest in the field of gene delivery. This perspective aims to summarize the latest studies of star polymers as gene delivery vectors. Specifically, the aim is to identify and discuss the main synthetic methodologies that are used to fabricate star polymers and which structural characteristics affect their ability to be used as gene delivery agents. © 2014 Society of Chemical Industry
Side‐on main‐chain liquid crystalline polymers prepared by acyclic diene metathesis polymerization and thiol‐ene click step‐growth polymerization
Authors: Yang Hong , Lv You‐Jing , Lin Bao‐Ping , Zhang Xue‐Qin , Sun Ying , Guo Ling‐Xiang
Published: February 2014

In this manuscript, we design and synthesize a series of X‐shaped mesogenic monomers, bearing two terminal‐alkene tails. Starting from these X‐shaped monomers, acyclic diene metathesis polymerization and thiol‐ene polyaddition are applied for the first time to prepare two series of side‐on main‐chain liquid crystalline polymers (LCPs), respectively. The mesomorphic behaviors and structure‐property relationships of these new polymers are studied in detail by a combination of1H NMR, GPC, TGA, DSC, POM, and XRD experiments. It turns out that the length of alkoxy terminal chains of the embedded mesogens and the length of the spacer connecting two adjacent mesogens on the polymer backbones markedly influence the mesomorphic properties. Furthermore, a side‐on main‐chain liquid crystalline elastomer fiber is prepared by crosslinking the LCP using a UV‐sensitive bifunctional benzophenone crosslinker. In comparison with the pure polymer fiber's monodomain alignment, the crosslinked elastomer fiber however shows nonaligned polydomain structure, probably due to the order competitions between the mixed crosslinkers, mesogens, and polymer backbones. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem.2014,52, 1086–1098
Dyadic effects of coping strategies on emotional state and quality of life in prostate cancer patients and their spouses
Authors: Lafaye Anaïs , Petit Sylvie , Richaud Pierre , Houédé Nadine , Baguet Fanny , Cousson‐Gélie Florence
Published: February 2014

Background

During cancer, coping strategies adopted by patients with prostate cancer and their spouses have an effect on their own emotional state and quality of life (QoL). However, the effects of coping strategies used by a member of a couple on the well‐being of the other member are unknown. The aim of this study is to examine the dyadic effects of coping strategies on the emotional state and QoL of couples dealing with cancer.

Methods

Ninety‐nine couples completed various self‐questionnaires to assess psychological and physical QoL, anxiety, depressive symptoms, and coping strategies at the beginning, middle, and end of primary treatment.

Results

Results obtained with the actor–partner interdependence model showed that coping strategies used by patients or spouses play a key role not only in their own well‐being but also in their partners'. Indeed, when patients use problem‐focused coping or social support‐seeking, they, as well as their spouses, experience fewer anxiety and depressive symptoms. Conversely, patients or spouses who use emotion‐focused coping experience higher levels of anxiety and depressive symptoms. Finally, and it is a surprising result, when spouses seek social support, patients feel greater anxiety.

Conclusions

These findings suggest that both patients and spouses should be included in psychosocial programs, which develop and reinforce their ability to cope with cancer. Couples may benefit from membership in support groups allowing them to share their experiences. Copyright © 2014 John Wiley & Sons, Ltd.
High‐Strength Pressure‐Free Bonding Using Cu and Ni‐Sn Nanoparticles
Authors: Watanabe Ryota , Ishizaki Toshitaka
Published: February 2014

High‐strength pressure‐free bonding is investigated using Cu nanoparticles as an alternative to conventional solders. Focus is placed on the morphology of Ni‐Sn intermetallic nanoparticles, an additive to a paste of Cu nanoparticles, for improvement of sinterability. The shear strength increases from 23.2 (Cu nanoparticles only) to 31.8 MPa, when 10 wt% of the newly synthesized 15‐nm Ni3Sn2 nanocubes is mixed with the Cu nanoparticle paste. This is the first example of the use of base metal nanoparticles under pressure‐free conditions to achieve the bonding strength of an ordinary Pb‐free solder (Sn‐Ag‐Cu). The addition of smaller Ni3Sn2 nanocubes 8 nm in size or irregularly shaped Ni3Sn2 nanoparticles (25.0 MPa) results in a limited increase in shear strength (26.6 MPa), while the addition of micrometer‐sized Ni3Sn2 particles results in a decrease in shear strength (21.5 MPa). The effects of the size and shape of the added Ni3Sn2 particles on the shear strength are discussed based on SEM observation of the sintered layers.
Ensembles of protein termini and specific proteolytic signatures as candidate biomarkers of disease
Authors: Huesgen Pitter F. , Lange Philipp F. , Overall Christopher M.
Published: February 2014

Early accurate diagnosis and personalized treatment are essential in order to treat complex or fatal diseases such as cancer and autoimmune, cardiovascular and neurodegenerative diseases. To realize this vision, new diagnostic and prognostic biomarkers are urgently required. MS‐based proteomics is the most promising approach for protein biomarker identification, but suffers in clinical translation of biomarker candidates that show only quantitative differences from normal tissue. Indeed, success in translating proteomic data to biomarkers in the clinic has been disappointing. Here, we propose that protein termini provide a new opportunity for biomarker discovery due to qualitative differences in intact and new protein termini between diseased and normal tissues. Altered proteolysis occurs in most pathologies. Disease‐ and process‐specific protein modifications, including proteolytic processing and subsequent modification of the terminal amino acids, frequently lead to altered protein activity that plays key roles in the disease process. Thus, mapping of ensembles of characteristic protein termini provides a proteolytic signature of high information content that shows both quantitative and most importantly qualitative differences in different diseases and stage of disease. These unique protein biomarkers have the added benefit of being mechanistically informative by revealing the activity state of the bioactive protein. Moreover, proteome‐wide isolation of protein termini leads to generalized sample simplification, thereby enabling up to three orders of magnitude lower LODs compared to traditional shotgun proteomic approaches. We introduce the potential of protein termini for biomarker discovery, briefly review methods enabling large‐scale studies of protein termini, and discuss how these may be integrated into a termini‐oriented biomarker discovery pipeline from discovery to clinical application.
Loss functions and their applications in process safety assessment
Authors: Hashemi Seyed Javad , Ahmed Salim , Khan Faisal
Published: February 2014

Process deviations, along with failure of control systems and protection layers, result in safety and quality loss in plant operations. This article proposes an operational risk‐based warning system design methodology based on overall system loss. Loss functions (LFs) are used to define the relationship between process deviations and system loss. For this purpose, properties associated with quadratic LF and a set of inverted probability LFs are investigated and compared. The results suggest that LFs can be used in a novel way to assess operational stability and system safety. The proposed consequence assessment methodology using LFs is then incorporated into a risk‐based warning system design model to analyze warnings associated with process deviations. A simulated case study is presented to demonstrate potential application of the proposed methodology; the study examines the response to a temperature surge for a reactor system. © 2014 American Institute of Chemical Engineers Process Saf Prog 33: 285–291, 2014
The potential of III‐nitride laser diodes for solid‐state lighting
Authors: Wierer Jonathan J. , Tsao Jeffrey Y. , Sizov Dmitry S.
Published: February 2014

The potential of III‐nitride based laser diodes (LDs) for solid‐state lighting (SSL) is discussed. State‐of‐the‐art blue LDs have higher efficiencies at high input power densities when compared to blue light‐emitting diodes (LEDs). This is because the processes that cause the drop in efficiency at high currents for LEDs are not present in the LD operated under stimulated emission. Projections of efficiency improvement show blue LDs have the potential to be nearly as efficient as blue LEDs and provide similar lumen output at much higher input powers. This result provides the possibility that white sources created from blue LD pumped phosphors could someday become a competitive and viable SSL source. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical properties and carrier dynamics in m ‐plane InGaN quantum wells
Authors: Marcinkevičius Saulius , Kelchner Kathryn M. , Nakamura Shuji , DenBaars Steven P. , Speck James S.
Published: February 2014

Scanning near‐field and time‐resolved photoluminescence spectroscopy have been applied to characterize single m‐plane InGaN QW structures. The PL spectra were found to be formed by emission from the extended and the localized states. Lateral dimensions of uniform potential regions were placed around a few tens of nm. It was shown that optimization of the template for the QW growth results in a more uniform emission spectrum and a reduced effect of carrier localization. The radiative recombination time at low temperatures was found to be short, about 0.5 ns. At room temperature, nonradiative recombination via efficient recombination centres was prevailing. Complexes of Ga vacancies with O were suggested to play this role. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Atomistic simulations of InGaN/GaN random alloy quantum well LEDs
Authors: López M. , Pecchia A. , Auf der Maur M. , Sacconi F. , Penazzi G. , Di Carlo A.
Published: February 2014

In this work, a random distribution of Indium in a quantum well has been considered to study the effect on the energy gap of a GaN/InGaN/GaN LED device. Monte Carlo sampling technique has been used to generate hundreds of atomistic model structures of the device active region. In order to calculate pseudomorphic strain and internal deformations of the alloy, a multiscale method combining continuous media elasticity and atomistic valence force field models has been used. A multiphysic quantum/classical simulation coupling driftdiffusion with empirical tight‐binding in order to compute the electron and hole states of the system has been performed. The reliable sp3d5s* parametrization has been used in the calculations of the eigenstates. We have found an energy gap difference of 50.9 meV for x (In) = 0.1 molar fraction between using virtual crystal approximation and a random distribution of In which increase with increasing Indium concentration. Moreover, electrons wave function seems to be more sensitive than holes due to Indium fluctuations
Optical anisotropy of m ‐plane nitride air‐gap distributed Bragg reflector microcavities
Authors: Tao Renchun , Arita Munetaka , Kako Satoshi , Arakawa Yasuhiko
Published: February 2014

We investigated the optical anisotropy properties of m‐plane air/AlGaN distributed Bragg reflector microcavities fabricated by the thermal decomposition of GaN. Micro‐photoluminescence measurements were performed at room temperature. From the recorded spectrum, two cavity modes with different polarization direction (parallel to a and c) were observed, which are attributed to the birefringence properties of the non‐polar nitride structure.

In addition, the mode with E ‖ a has a higher PL intensity than that of the mode with E ‖ c. Based on k · p Hamiltonians, the matrix elements were calculated around the Γ point, revealing the origin of the mode intensity difference. These results would be very helpful for exciton‐cavity coupling research in non‐polar microcavities. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Luminescence of erbium doped aluminum nitride nanoparticles synthesized using inert gas condensation
Authors: Pandya Sneha G. , Kordesch Martin E.
Published: February 2014

Erbium doped aluminum nitride (AlN:Er) nanoparticles (NPs) were synthesized using the inert gas condensation (IGC) technique. As deposited AlN:Er NPs with 30 nm to 100 nm diameters were observed using transmission electron microscopy and field emission scanning electron microscopy. Photoluminescence from selected NPs showed Er3+ ion emission peaks similar to those seen in Er doped AlN thin films: 540 nm and 560 nm with peak widths of 6 nm and 10 nm respectively.

Luminescence from NPs that were heated in air at 1000 °C consisted of several sharp overlapping peaks in the range of 535 nm to 565 nm. As in thin films, the relative intensity of characteristic Er peaks of these AlN:Er NPs was confirmed to be temperature dependent. This makes Er doped NPs useful for nano‐thermometers. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Viability of the use of thin‐film a‐SiC:H photodiodes for protein identification
Authors: Louro P. , Silva V. , Karmali A. , Vieira M.
Published: February 2014

In this paper, we present a multilayer device based on a‐Si:H/a‐SiC:H that operates as photodetector and optical filter. The use of such device in protein detection applications is relevant in Fluorescence Resonance Energy Transfer (FRET) measurements. This method demands the detection of fluorescent signals located at specific wavelengths bands in the visible part of the electromagnetic spectrum. The device operates in the visible range with a selective sensitivity dependent on electrical and optical bias. Several nanosensors were tested with a commercial spectrophotometer to assess the performance of FRET signals using glucose solutions of different concentrations. The proposed device was used to demonstrate the possibility of FRET signals detection, using visible signals of similar wavelength and intensity. The device sensitivity was tuned to enhance the wavelength band of interest using steady state optical bias at 400 nm. Results show the ability of the device to detect signals in this range. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ab‐initio calculations and structural studies of (SiTe)2(Sb2Te3)n (n: 1, 2, 4 and 6) phase‐change superlattice films
Authors: Saito Y. , Tominaga J. , Fons P. , Kolobov A. V. , Nakano T.
Published: February 2014

(SiTe)2(Sb2Te3)n phase‐change superlattices were investigated theoretically and experimentally. Ab‐initio first principle simulations predicted that the (SiTe)2(Sb2Te3)n structures are stable and possess a Dirac semimetal‐like band structure. Calculation of the Z2 invariant indicated that the structure was topologically nontrivial. (SiTe)2(Sb2Te3)n superlattice structures derived from first‐principles were successfully fabricated on a Si substrate by RF‐magnetron sputtering. XRD and TEM indicated that the superlattice films were highly oriented with the 00X planes of Sb2Te3 and the superlattice normal to the substrate surface. The (SiTe)2(Sb2Te3)n superlattice is suggested as new material system for interfacial phase‐change memory applications. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
EFFECTS OF FLOW REGULATION AND NON‐NATIVE SPECIES ON FEEDING HABITS OF EURASIAN OTTER Lutra lutra IN MEDITERRANEAN TEMPORARY RIVERS
Authors: Bueno‐Enciso J. , Díaz‐Ruiz F. , Almeida D. , Ferreras P.
Published: February 2014

In Mediterranean temporary rivers, ecological resources greatly fluctuate because of the high hydrological variability throughout the year. However, flow regulation prevents this natural regime and commonly entails associated non‐native species, which change the structure of aquatic communities. Nonetheless, few studies have tested the interaction of these two disruptive factors (flow regulation and non‐native species) and their synergistic effects on the Eurasian otter (Lutra lutra) diet at the river scale. The aim of this study was to compare the seasonal feeding habits of the otter between a temporary non‐regulated stretch and two regulated stretches invaded by non‐native species in a Mediterranean water course. The Bullaque River (Guadiana River Basin, central Spain) was seasonally sampled for otter spraints and prey abundance assessed from December 2009 to November 2010. Three stretches were considered: high (source, non‐regulated), medium (transition, regulated) and low (confluence, regulated). Diet varied from native prey in the high stretch (amphibians, insects and endemic cyprinids) to non‐native species in the low stretch (red‐swamp crayfish Procambarus clarkii and pumpkinseed sunfish Lepomis gibbosus). Seasonally, ingested biomass of native prey increased in spring. Diet was more diverse in the high stretch. Otters neutrally selected native cyprinids in the high stretch throughout the year, whereas crayfish was selected in the other two stretches. Overall results showed that flow regulation and non‐native species have increased prey availability for the otter; however, this paper highlights the importance of maintaining natural regimes in Mediterranean temporary rivers to conserve native communities and thus minimally impact food webs in Iberian freshwaters. Copyright © 2014 John Wiley & Sons, Ltd.
Direct regression models for longitudinal rates of change
Authors: Bryan Matthew , Heagerty Patrick J.
Published: February 2014

Comparing rates of growth, or rates of change, across covariate‐defined subgroups is a primary objective for many longitudinal studies. In the special case of a linear trend over time, the interaction between a covariate and time will characterize differences in longitudinal rates of change. However, in the presence of a non‐linear longitudinal trajectory, the standard mean regression approach does not permit parsimonious description or inference regarding differences in rates of change. Therefore, we propose regression methodology for longitudinal data that allows a direct, structured comparison of rates across subgroups even in the presence of a non‐linear trend over time. Our basic longitudinal rate regression method assumes a proportional difference across covariate groups in the rate of change across time, but this assumption can be relaxed. Rates are compared relative to a generally specified time trend for which we discuss both parametric and non‐parametric estimating approaches. We develop mixed model longitudinal methodology that explicitly characterizes subject‐to‐subject variation in rates, as well as a marginal estimating equation‐based method. In addition, we detail a score test to detect violations of the proportionality assumption, and we allow time‐varying rate effects as a natural generalization. Simulation results demonstrate potential gains in power for the longitudinal rate regression model relative to a linear mixed effects model in the presence of a non‐linear trend in time. We apply our method to a study of growth among infants born to HIV infected mothers and conclude with a discussion of possible extensions for our methods. Copyright © 2014 John Wiley & Sons, Ltd.
Why strategic factor markets matter: “New” multinationals' geographic diversification and firm profitability
Authors: Kim Heechun , Hoskisson Robert E. , Lee Seung‐Hyun
Published: February 2014

This study examines firm profitability differences among “new” multinational enterprises (NMNEs) pursuing geographic diversification into two distinct types of geographic locations based on the development of strategic factor markets. Building on strategic factor markets theory, we propose that firm‐specific advantages of NMNEs contribute differentially to firm profitability because they evolve differently given strategic factor market differences in host compared to home countries. Using a sample of Korean manufacturing MNEs during the 1993–2003 period, we find that geographic diversification into resource‐poorer host countries has a positive relationship with firm profitability, whereas geographic diversification into resource‐richer host countries has a U‐shaped relationship with firm profitability. Our study demonstrates why strategic factor markets—an important and often overlooked contextual factor—matter in exploring rationales for geographic diversification. Copyright © 2014 John Wiley & Sons, Ltd.
Cell Senescence Abrogates the Therapeutic Potential of Human Mesenchymal Stem Cells in the Lethal Endotoxemia Model
Authors: Carlos Sepúlveda Juan , Tomé María , Eugenia Fernández María , Delgado Mario , Campisi Judith , Bernad Antonio , González Manuel A.
Published: February 2014

Mesenchymal stem cells (MSCs) possess unique paracrine and immunosuppressive properties, which make them useful candidates for cellular therapy. Here, we address how cellular senescence influences the therapeutic potential of human MSCs (hMSCs). Senescence was induced in bone marrow-derived hMSC cultures with gamma irradiation. Control and senescent cells were tested for their immunoregulatory activity in vitro and in vivo, and an extensive molecular characterization of the phenotypic changes induced by senescence was performed. We also compared the gene expression profiles of senescent hMSCs with a collection of hMSCs used in an ongoing clinical study of Graft Versus Host disease (GVHD). Our results show that senescence induces extensive phenotypic changes in hMSCs and abrogates their protective activity in a murine model of LPS-induced lethal endotoxemia. Although senescent hMSCs retain an ability to regulate the inflammatory response on macrophages in vitro, and, in part retain their capacity to significantly inhibit lymphocyte proliferation, they have a severely impaired migratory capacity in response to proinflammatory signals, which is associated with an inhibition of the AP-1 pathway. Additionally, expression analysis identified PLEC, C8orf48, TRPC4, and ZNF14, as differentially regulated genes in senescent hMSCs that were similarly regulated in those hMSCs which failed to produce a therapeutic effect in a GVHD trial. All the observed phenotypic alterations were confirmed in replicative-senescent hMSCs. In conclusion, this study highlights important changes in the immunomodulatory phenotype of senescent hMSCs and provides candidate gene signatures which may be useful to evaluate the therapeutic potential of hMSCs used in future clinical studies. Stem Cells  2014;32:1865–1877
Concise Review: Genetic Dissection of Hypoxia Signaling Pathways in Normal and Leukemic Stem Cells
Authors: Gezer Deniz , Vukovic Milica , Soga Tomoyoshi , Pollard Patrick J. , Kranc Kamil R.
Published: February 2014

Adult hematopoiesis depends on rare multipotent hematopoietic stem cells (HSCs) that self-renew and give rise to progenitor cells, which differentiate to all blood lineages. The strict regulation of the fine balance between self-renewal and differentiation is essential for normal hematopoiesis and suppression of leukemia development. HSCs and progenitor cells are commonly assumed to reside within the hypoxic BM microenvironment, however, there is no direct evidence supporting this notion. Nevertheless, HSCs and progenitors do exhibit a hypoxic profile and strongly express Hif-1α. Although hypoxia signaling pathways are thought to play important roles in adult HSC maintenance and leukemogenesis, the precise function of Hif-dependent signaling in HSCs remains to be uncovered. Here we discuss recent gain-of-function and loss-of-function studies that shed light on the complex roles of hypoxia-signaling pathways in HSCs and their niches in normal and malignant hematopoiesis. Importantly, we comment on the current and often contrasting interpretations of the role of Hif-dependent signaling in stem cell functions. Stem Cells  2014;32:1390–1397
Insulin-Like Growth Factor Promotes Cardiac Lineage Induction In Vitro by Selective Expansion of Early Mesoderm
Authors: Engels Marc C. , Rajarajan Kuppusamy , Feistritzer Rebecca , Sharma Arun , Nielsen Ulrik B. , Schalij Martin J. , Vries Antoine A.F. , Pijnappels Daniël A. , Wu Sean M.
Published: February 2014

A thorough understanding of the developmental signals that direct pluripotent stem cells (PSCs) toward a cardiac fate is essential for translational applications in disease modeling and therapy. We screened a panel of 44 cytokines/signaling molecules for their ability to enhance Nkx2.5+ cardiac progenitor cell (CPC) formation during in vitro embryonic stem cell (ESC) differentiation. Treatment of murine ESCs with insulin or insulin-like growth factors (IGF1/2) during early differentiation increased mesodermal cell proliferation and, consequently, CPC formation. Furthermore, we show that downstream mediators of IGF signaling (e.g., phospho-Akt and mTOR) are required for this effect. These data support a novel role for IGF family ligands to expand the developing mesoderm and promote cardiac differentiation. Insulin or IGF treatment could provide an effective strategy to increase the PSC-based generation of CPCs and cardiomyocytes for applications in regenerative medicine. Stem Cells  2014;32:1493–1502
Concise Review: Evidence for CD34 as a Common Marker for Diverse Progenitors
Authors: Sidney Laura E. , Branch Matthew J. , Dunphy Siobhán E. , Dua Harminder S. , Hopkinson Andrew
Published: February 2014

CD34 is a transmembrane phosphoglycoprotein, first identified on hematopoietic stem and progenitor cells. Clinically, it is associated with the selection and enrichment of hematopoietic stem cells for bone marrow transplants. Due to these historical and clinical associations, CD34 expression is almost ubiquitously related to hematopoietic cells, and it is a common misconception that CD34-positive (CD34+) cells in nonhematopoietic samples represent hematopoietic contamination. The prevailing school of thought states that multipotent mesenchymal stromal cells (MSC) do not express CD34. However, strong evidence demonstrates CD34 is expressed not only by MSC but by a multitude of other nonhematopoietic cell types including muscle satellite cells, corneal keratocytes, interstitial cells, epithelial progenitors, and vascular endothelial progenitors. In many cases, the CD34+ cells represent a small proportion of the total cell population and also indicate a distinct subset of cells with enhanced progenitor activity. Herein, we explore common traits between cells that express CD34, including associated markers, morphology and differentiation potential. We endeavor to highlight key similarities between CD34+ cells, with a focus on progenitor activity. A common function of CD34 has yet to be elucidated, but by analyzing and understanding links between CD34+ cells, we hope to be able to offer an insight into the overlapping properties of cells that express CD34. Stem Cells  2014;32:1380–1389