bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of ultra‐performance liquid chromatography/time‐of‐flight mass spectrometry with nozzle‐skimmer fragmentation for comprehensive quantitative analysis of secondary metabolites in Arabidopsis thaliana
Authors: Sugimoto Takanori , Bamba Takeshi , Izumi Yoshihiro , Nomura Hironari , Shiina Takashi , Fukusaki Eiichiro 
Published: November 2011

AbstractThis study sought to develop techniques for LC/MS‐based metabolomics and to verify that an MS/MS spectral tag (MS2T) could be used in practical secondary metabolite profiling. The retention time (RT), precursor ions, and fragment ions generated by nozzle‐skimmer fragmentation were determined using ultra‐performance liquid chromatography/time‐of‐flight mass spectrometry (UPLC/TOF‐MS) and compared with the MS2T. A standard mix was analyzed with UPLC/TOF‐MS under the same conditions as were used to construct the MS2T. The difference in RT for the standards was less than 0.15 min and the average RSD was about 2.8%, suggesting that the analysis was highly repeatable. Both precursor ions and fragment ions were observed when the cone voltage was 75 V. Experimental data and fragmentation pattern in the MS2T annotation list were highly similar. Wild‐type and cas‐1 mutant Arabidopsis thaliana samples treated with an elicitor were analyzed using UPLC/TOF‐MS. Sixty‐five peaks were successfully annotated. Fragment ions were observed with nozzle‐skimmer fragmentation in 50 of 65 (77%) peaks. The reliability of annotation may have increased as a result of fragment ions. Results of multivariate analysis suggested that cas‐1 was related to induction of the biosynthesis of these flavonoids. The devised method facilitated practical secondary metabolite profiling.
Selective removal of caffeine from tea extracts using macroporous crosslinked polyvinyl alcohol adsorbents
Authors: Ma Ning , Wang Peng , Kong Xia , Shi Rongfu , Yuan Zhi , Wang Chunhong 
Published: November 2011

AbstractThe hydrolysis reaction of ester groups in vinyl acetate (VAc) was used to introduce hydroxyl groups into the matrix of a macroporous adsorbent, which was itself prepared by free radical suspension copolymerization of triallyl isocyanurate (TAIC) and VAc. Therefore, the copolymerization incompatibility between the hydrophilic and the hydrophobic monomer was overcome successfully and the hydrophobic matrix of the polymeric adsorbent containing a polyvinyl alcohol (PVA) segment was obtained. Introduction of the PVA segment decreased the hydrophobic adsorption affinity of the adsorbent while producing the hydrogen‐bonding interaction. When isolating the two active components, polyphenols (TPh) and caffeine (CAF), from green tea extracts, this polymeric adsorbent, namely poly(TAIC‐co‐VA), exhibited good adsorption selectivity towards TPh over CAF. The adsorption mechanism leading to this selectivity involved a hydrophobic interaction mechanism for CAF and multiple weak hydrophobic and hydrogen‐bonding interactions for TPh. The adsorption thermodynamics for TPh on poly(TAIC‐co‐VA) were studied. The effects of adsorbent structure and gradient desorption conditions on isolation were investigated. The result showed that adsorbent, with 20% TAIC content, was able to efficiently remove CAF from different tea extracts with different ratios of TPh and CAF. Finally, almost no CAF was detected in the TPh fraction and the recovery of TPh was greater than 95%.
Selective determination of trace thiamphenicol in milk and honey by molecularly imprinted polymer monolith microextraction and high‐performance liquid chromatography
Authors: Li Juan , Chen Huaixia , Chen Hui , Ye Yong 
Published: November 2011

AbstractA novel solid‐phase microextraction (SPME) method based on molecularly imprinted polymer (MIP) monolith as the sorbent for the selective extraction of thiamphenicol (TAP) in milk and honey was developed. The newly developed MIP monolith was produced using TAP as the template molecule, 4‐vinylpyridine (4‐VP) as the functional monomer. The TAP‐MIP monolith synthesized in a micropipette tip could be connected with syringes in different sizes simply to perform SPME process without any other treatment. The derivated MIP monolith showed high selectivity and enrichment ability for TAP. A simple, rapid and sensitive method for the determination of TAP in milk and honey using polymer monolith microextraction (PMME) based on the MIP monolith combined with high‐performance liquid chromatography‐photodiodes array detector was developed. Several parameters affecting MIP monolith microextraction were investigated, including the flow rate, volume, pH and salt concentration of sample, the type and volume of washing solution, the type and flow rate of eluent. The recovery of this method for TAP was investigated and high recoveries of 92.9–99.3% from milk and honey were obtained with relative standard deviations less than 4.9%.
Randomized controlled trial on postoperative pulmonary humidification after total laryngectomy: External humidifier versus heat and moisture exchanger
Authors: Mérol Jean‐Claude , Charpiot Anne , Langagne Thibault , Hémar Patrick , Ackerstaff Annemieke H. , Hilgers Frans J. M. 
Published: November 2011

AbstractObjectives/Hypothesis:Assessment of immediate postoperative airway humidification after total laryngectomy (TLE), comparing the use of an external humidifier (EH) with humidification through a heat and moisture exchanger (HME).Study Design:Randomized controlled trial (RCT).Methods:Fifty‐three patients were randomized into the standard (control) EH (N = 26) or the experimental HME arm (N = 27). Compliance, pulmonary and sleeping problems, patients' and nursing staff satisfaction, nursing time, and cost‐effectiveness were assessed with trial‐specific structured questionnaires and tally sheets.Results:In the EH arm data were available for all patients, whereas in the HME arm data were incomplete for four patients. The 24/7 compliance rate in the EH arm was 12% and in the HME arm 87% (77% if the four nonevaluable patients are considered noncompliant). Compliance and patients' satisfaction were significantly better, and the number of coughing episodes, mucus expectoration for clearing the trachea, and sleeping disturbances were significantly less in the HME arm (P < .001). This was also the case for nursing time and nursing staff satisfaction and preference.Conclusions:This RCT clearly shows the benefits of immediate postoperative airway humidification by means of an HME over the use of an EH after TLE. This study therefore underlines that HMEs presently can be considered the better option for early postoperative airway humidification after TLE.
A new analytical solution based on joint relaxation for analyzing symmetrical block stability
Authors: Bagheri M. , Stille H. 
Published: November 2011

SUMMARYThe magnitude of clamping forces has a significant influence on the estimated ultimate pullout force of a block. The Crawford–Bray equation, which is fundamental in considering clamping forces, is only a function of horizontal stress and block height. Further research to incorporate the influence of induced stress in block stability analysis was considered, but all the previous analytical solutions for analyzing block stability assume a continuum medium to estimate clamping forces and do not allow joint deformations to occur before block movement due to gravity. Assuming a continuous medium to estimate clamping forces leads to an overestimation of block stability and therefore unsafe design. In this paper, an attempt has been made to deepen the understanding of the block failure mechanism and correct the estimated magnitude of clamping forces in a discontinuous medium. A conceptual model is proposed based on the loading–unloading of the block from an in‐situ state to failure. Based on this model, an analytical solution has been developed that calculates clamping forces in a discontinuous medium. The validity and model uncertainty of the solution were checked for different conditions. The new analytical solution is both precise and accurate and can be used as a design tool to estimate block stability. Copyright © 2011 John Wiley & Sons, Ltd.
A 6000‐Year‐Old Hand Amputation from Bulgaria—The Oldest Case from South‐East Europe?
Authors: Zäuner S. P. , Wahl J. , Boyadziev Y. , Aslanis I. 
Published: November 2011

ABSTRACTA skeleton from Tell Yunatsite in Bulgarian Thrace shows evidence of amputation of the right hand. The individual dates back to the end of the fifth millennium, connecting it to the Late Copper Age of that region. The Chalcolithic settlement on the tell ended immediately after a bellicose assault. Therefore, the question arose if the loss of the hand may be connected with this incidence. Anthropological studies in close collaboration with the archaeologists on site made clear that the abscission took place at an earlier time. This result led to a series of complex questions. These are described in this work. We will show that a congenital origin for the loss of the hand can be excluded, and that the individual survived this severe injury for a certain time span. Several possible explanations for an amputation are discussed. It turns out that a surgical intervention seems to be the most likely reason. It becomes clear that there must have been an excellent medical knowledge in the Copper Age concerning surgery and wound treatment. Furthermore, the survival of the handicapped individual documents a certain social cohesion. Copyright © 2011 John Wiley & Sons, Ltd.
Chronic cardiac allograft rejection: critical role of ED‐A+ fibronectin and implications for targeted therapy strategies
Authors: Franz Marcus , Neri Dario , Berndt Alexander 
Published: November 2011

AbstractChronic cardiac allograft rejection is characterized by cardiac allograft vasculopathy (CAV) and cardiac interstitial fibrosis (CIF) causing severe long‐term complications after heart transplantation and determining allograft function and patients' prognosis. Until now, there have been no sufficient preventive or therapeutic strategies. CAV and CIF are accompanied by changes in the extracellular matrix, including re‐expression of the fetal fibronectin splice variant known as ED‐A+ fibronectin. This molecule has been shown to be crucial for the development of myofibroblasts (MyoFbs) as the main cell type in CIF and for the activation of vascular smooth muscle cells (VSMCs) as the main cell type in CAV. Relevant re‐expression and protein deposition of ED‐A+ fibronectin has been demonstrated in animal models of chronic rejection, with spatial association to CAV and CIF, and a quantitative correlation to the rejection grade. The paper by Booth et al published in this issue of The Journal of Pathology could prove for the first time the functional importance of ED‐A+ fibronectin for the development of CIF as a main component of chronic cardiac rejection. Thus, promising conclusions for the development of new diagnostic, preventive, and therapeutic strategies for chronic cardiac rejection focusing on ED‐A+ fibronectin can be suggested. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Genetic and epigenetic similarities and differences between childhood and adult AML
Authors: Juhl‐Christensen Caroline , Ommen Hans Beier , Aggerholm Anni , Lausen Birgitte , Kjeldsen Eigil , Hasle Henrik , Hokland Peter 
Published: November 2011

AbstractBackgroundThe biology of acute myeloid leukemia (AML) is complex and includes both genetic and epigenetic aberrations. We addressed the combined consequences of promoter hypermethylation of p15, CDH1, ER, MDR1, and RARB2 and mutation of NPM1, CEBPA, FLT3, and WT1 in a Danish cohort of 70 pediatric and 383 adult AML patients.ProcedureMutation analysis was done by fragment analysis followed by sequencing or by sequencing alone. Methylation status was determined using methylation‐sensitive melting curve analysis (MS‐MCA) after initial bisulfite modification.ResultsAmong pediatric AMLs, we found promoter hypermethylation in p15 (47%), CDH1 (64%), ER (62%), MDR1 (8%), and RARB2 (22%) and mutations in NPM1 (11%), CEBPA (3%), FLT3ITD (4%), FLT3D835 (7%), and WT1 (7%). Promoter hypermethylation was significantly more frequent in core binding factor leukemias (CBF) compared to AMLs with abnormalities involving 11q23 (P = 0.024). Compared to adult AML we found a significant difference in p15 (47% vs. 73%, P < 0.001) and RARB2 (22% vs. 42%, P = 0.003) methylation, as well as in NPM1 (11% vs. 31%, P = 0.001) and FLT3ITD (4% vs. 26%, P < 0.001) mutation.ConclusionAge‐related differences exist in the frequency of mutations and it appears that promoter hypermethylation occurs in a non‐random pattern in childhood AML accompanying specific genetic aberrations, and might represent an important step in the leukemogenic transformation. Pediatr Blood Cancer 2012; 58: 525–531. © 2011 Wiley Periodicals, Inc.
Mutations profile of polycythemia vera and essential thrombocythemia among Japanese children
Authors: Ismael Olfat , Shimada Akira , Hama Asahito , Sakaguchi Hiroshi , Doisaki Sayoko , Muramatsu Hideki , Yoshida Nao , Ito Masafumi , Takahashi Yoshiyuki , Akita Naohiro , Sunami Shosuke , Ohtsuka Yoshitoshi , Asada Youji , Fujisaki Hiroyuki , Kojima Seiji 
Published: November 2011

AbstractBackgroundAcquired somatic mutations of JAK2 have been reported to play a pivotal role in the pathogenesis of BCR‐ABL1‐negative myeloproliferative neoplasm (MPN). However, the molecular characteristics of childhood MPN remain to be elucidated.Patient and MethodsWe investigated a group of pediatric patients diagnosed either with essential thrombocythemia (ET; N = 9) or polycythemia vera (PV; N = 4) according to WHO criteria (median age = 10 years; range 1.5–15 years) in whom direct sequencing was performed for the existence of genetic alterations in JAK2, MPL, TET2, ASXL1, CBL, IDH1, and IDH2. More sensitive allele specific polymerase chain reaction was used for JAK2V617F genotyping.ResultsWe found three patients harbor JAK2V617F mutation (2/9 ET and 1/4 PV). Bone marrow examination showed small and large megakaryocytes with dysplastic features in JAK2V617F‐positive ET patients compared to those without JAK2V617F. We identified a previously unrecognized missense mutation at codon 1230 in exon 12 of ASXL1 gene in ET and PV patients (1/9 ET and 1/4 PV). Otherwise, no genetic alterations could be detected in JAK2 exon 12, MPL, TET2, CBL, IDH1, and IDH2 in all ET and PV patients.ConclusionAlthough JAK2 mutations in childhood ET and PV are not as frequent as reported in adult patients, JAK2 is the most frequently mutated gene in childhood MPN known so far. Owing to the presence of childhood MPN without any genetic alterations in JAK2, MPL, TET2, ASXL1, CBL, IDH1, and IDH2, new biological markers have to be found. Pediatr Blood Cancer 2012;59:530–535. © 2011 Wiley Periodicals, Inc.
Microcontroller‐based simple maximum power point tracking controller for single‐stage solar stand‐alone water pumping system
Authors: Packiam P. , Jain N. K. , Singh I. P. 
Published: November 2011

ABSTRACTA simple microcontroller‐based maximum power point tracking controller is proposed for a single‐stage solar stand‐alone water pumping system for remote, isolated, and nonelectrified population, where less maintenance, low cost, and an efficient system is of prime interest. It consists of a photovoltaic (PV) module, a DC–AC converter utilizing space‐vector pulse‐width modulation, an induction motor coupled with a water pump, a voltage sensor, and a current sensor. A space‐vector pulse‐width modulation‐controlled DC–AC converter aided by a fast‐acting on–off supervisory controller with a modified perturb‐and‐observe algorithm performs both the functions of converting PV output voltage to a variable voltage, variable frequency output, as well as extracting the maximum power. A limited variable step size is preferred during transient state, and a steady frequency, which is calculated on the basis of steady‐state oscillation, is set during steady state. A fast‐acting on–off supervisory controller regulates DC link voltage during steady state and enables maximum power point tracking algorithm only during transient state to draw a new voltage reference. In the event of low voltage, the controller switches off the motor but continuously scans for an available PV voltage. The system is not protected against an overcurrent because the maximum current is equal to its short circuit current. The 16‐bit microcontroller dsPIC6010A (Microchip Technology, Inc., Chandler, AZ, USA) is used to implement the control functions. The proposed controller is verified through simulation as well as tested in the laboratory prototype model. The simulation and experimental results show good correlation. Copyright © 2011 John Wiley & Sons, Ltd.
High‐efficiency InGaN/GaN quantum well structures on large area silicon substrates
Authors: Zhu D. , McAleese C. , Häberlen M. , Kappers M. J. , Hylton N. , Dawson P. , Radtke G. , Couillard M. , Botton G. A. , Sahonta S.‐L. , Humphreys C. J. 
Published: November 2011

AbstractThe growth techniques which have enabled the realization of InGaN‐based multi‐quantum‐well (MQW) structures with high internal quantum efficiencies (IQE) on 150 mm (6‐in.) silicon substrates are reviewed. InGaN/GaN MQWs are deposited onto GaN templates on large‐area (111) silicon substrates, using AlGaN strain‐mediating interlayers to inhibit thermal‐induced cracking and wafer‐bowing, and using a SiNx interlayer to reduce threading dislocation densities in the active region of the MQW structure. MQWs with high IQE approaching 60% have been demonstrated. Atomic resolution electron microscopy and EELS analysis have been used to study the nature of the important interface between the Si(111) substrate and the AlN nucleation layer. We demonstrate an amorphous SiNx interlayer at the interface about 2 nm wide, which does not, however, prevent good epitaxy of the AlN on the Si(111) substrate.
Band gap reduction and dielectric function of Ga1−xZnxN1−xOx and In1−xZnxN1−xOx alloys
Authors: Dou Maofeng , Persson Clas 
Published: November 2011

AbstractThe band gap reductions, dielectric functions and absorption coefficients of the Ga1−xZnxN1−xOx and In1−xZnxN1−xOx (x = 0.00, 0.25, 0.50, 0.75, and 1.00) alloys were calculated, employing the partial self‐consistent GW approximation. As a comparison, the local density approximation (LDA) and the Heyd–Scueria–Ernzerhof (HSE) hybrid functional were also used to calculate the gap reduction. Both Ga1−xZnxN1−xOx and In1−xZnxN1−xOx alloys show strong band gap bowing. As a result, the band gap energy in Ga1−xZnxN1−xOx is reduced by Eg(GaN) − Eg (Ga1−xZnxN1−xOx) = 1.61, 2.01 and 1.91 eV for x = 0.25, 0.50, and 0.75, respectively. This allows optoelectronic devices based on GaN and ZnO with more efficient absorption or emission of light in the visible light range. The calculated dielectric functions and absorption spectra demonstrate that the band gap reduction enhances the optical absorption around the 2.5 eV region. Interestingly, the In1−xZnxN1−xOx alloy with x = 0.25 has the large optical absorption coefficient in the energy region 0.69–6.0 eV, and the alloy has very good absorption at 2–3 eV.
Investigation of a relaxation mechanism specific to InGaN for improved MOVPE growth of nitride solar cell materials
Authors: Pantzas K. , Patriarche G. , Orsal G. , Gautier S. , Moudakir T. , Abid M. , Gorge V. , Djebbour Z. , Voss P. L. , Ougazzaden A. 
Published: November 2011

AbstractIn this paper we report on a spontaneous 2D/3D transition observed in InGaN alloys after 60 nm of growth. This transition is responsible for the formation of a stack of distinct InGaN layers. The driving mechanism is shown to be lateral fluctuations of the indium composition, that arise to accommodate the increasing strain energy of the InGaN layer. Three distinct stages of growth have been identified. First, a homogeneous, 2D InGaN layer forms, pseudomorphically strained on the underlying GaN. Then, at around 30 nm large lateral fluctuations of the indium composition are observed and a second pseudomorphic layer, composed of indium‐rich and indium‐poor clusters, is formed. Finally induces a 2D/3D transition at 60 nm and a 3D InGaN layer is formed.
Laser induced temperature effects in multi‐walled carbon nanotubes probed by Raman spectroscopy
Authors: Judek Jaroslaw , Jastrzebski Cezariusz , Malolepszy Artur , Mazurkiewicz Marta , Stobinski Leszek , Zdrojek Mariusz 
Published: November 2011

AbstractWe examined the influence of continuous laser irradiation on as‐prepared and oxidized multi‐walled carbon nanotubes (MWCNTs) on the basis of Raman scattering. Differences between Raman spectra for both types of nanotube samples are shown. We evaluate the influence of the laser power density (LPD) on two main Raman modes (D and G) based on the position of the peaks, widths, and the relative intensity ID/IG ratio. Impurities and their interaction with nanotubes are crucial for interpretation of the measured effects. Oxidation, as well as the irradiation process, improves purity of samples. No structural changes of the tubes are observed. The Raman signal decrease is likely to originate from nanotube loss.
Threshold voltage stability comparison in AlGaN/GaN FLASH MOS‐HFETs utilizing charge trap or floating gate charge storage
Authors: Kirkpatrick Casey , Lee Bongmook , Choi YoungHwan , Huang Alex , Misra Veena 
Published: November 2011

AbstractEnhancement mode operation of AlGaN/GaN devices with breakdown voltage over 700 V is achieved by threshold shifting in a FLASH metal oxide semiconductor heterojunction field effect transistor. Charge stored during a programming step in either a charge trap or metal floating gate charge storage layer is responsible for this shift. Threshold stability for charge trap and floating gate memories is compared with charge trap devices losing <10% of initial threshold voltage shift after 104 seconds. Charge trap and floating gate devices maintain enhancement mode operation after 4 × 104 s. Threshold voltage as a function of drain bias for each storage method is compared. The most stable threshold voltage is observed when utilizing charge trap storage due to the discrete nature of the traps. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)