bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increasing the accuracy of mass isotopomer analysis through calibration curves constructed using biologically synthesized compounds
Authors: Shen Tie , Shen Weiqun , Xiong Ying , Liu Haiyan , Zheng Haoran , Zhou Hong , Rui Bin , Liu Jianping , Wu Jihui , Shi Yunyu 
Published: April 2009

AbstractMass isotopomer analysis is an important technique to measure the production and flow of metabolites in living cells, tissues, and organisms. This technique depends on accurate quantifications of different mass isotopomers using mass spectrometry. Constructing calibration curves using standard samples is the most universal approach to convert raw mass spectrometry measurements into quantitative distributions of mass isotopomers. Calibration curve approach has been, however, of very limited use in comprehensive analyses of biological systems, mainly suffering from the lack of extensive range of standard samples with accurately known isotopic enrichment. Here, we present a biological method capable of synthesizing specifically labeled amino acids. These amino acids have well‐determined and estimable mass isotopomer distributions and thus can serve as standard samples. In this method, the bacterium strain Methylobacterium salsuginis sp. nov. was cultivated with partially 13C‐labeled methanol as the only carbon source to produce 13C‐enriched compounds. We show that the mass isotopomer distributions of the various biosynthesized amino acids are well determined and can be reasonably estimated based on proposed binomial approximation if the labeling state of the biomass reached an isotopic steady state. The interference of intramolecular inhomogeneity of 13C isotope abundances caused by biological isotope fractionation was eliminated by estimating average 13C isotope abundance. Further, the predictions are tested experimentally by mass spectrometry (MS) spectra of the labeled glycine, alanine, and aspartic acid. Most of the error in mass spectrometry measurements was less than 0.74 mol% in the test case, significantly reduced as compared with uncalibrated results, and this error is expected to be less than 0.4 mol% in real experiment as revealed by theoretical analysis. Copyright © 2009 John Wiley & Sons, Ltd.
Microfluidic chips for mass spectrometry‐based proteomics
Authors: Lee Jeonghoon , Soper Steven A. , Murray Kermit K. 
Published: April 2009

AbstractMicrofluidic devices coupled to mass spectrometers have emerged as excellent tools for solving the complex analytical challenges associated with the field of proteomics. Current proteome identification procedures are accomplished through a series of steps that require many hours of labor‐intensive work. Microfluidics can play an important role in proteomic sample preparation steps prior to mass spectral identification such as sample cleanup, digestion, and separations due to its ability to handle small sample quantities with the potential for high‐throughput parallel analysis. To utilize microfluidic devices for proteomic analysis, an efficient interface between the microchip and the mass spectrometer is required. This tutorial provides an overview of the technologies and applications of microfluidic chips coupled to mass spectrometry for proteome analysis. Various approaches for combining microfluidic devices with electrospray ionization (ESI) and matrix‐assisted laser desorption/ionization (MALDI) are summarized and applications of chip‐based separations and digestion technologies to proteomic analysis are presented. Copyright © 2009 John Wiley & Sons, Ltd.
DC and small‐signal comparison of horizontal emitter designs of InGaP/GaAs heterojunction bipolar transistors
Authors: López‐González Juan M. 
Published: April 2009

AbstractThis paper describes the DC and small‐signal performance of two InGaP/GaAs heterojunction bipolar transistors (HBTs) that have the same chip size. This is done in order to compare emitter–base designs using the TCAD ATLAS device simulator. The HBT devices analyzed have the same cutoff and maximum frequencies but significant differences are observed in other characteristics such as base–emitter turn‐on voltage, saturation collector–emitter voltage, forward current gain, maximum transducer gain and maximum stable gain. Copyright © 2009 John Wiley & Sons, Ltd.
The regime shift in the early 1980s of spring precipitation in Korea
Authors: Choi Ki‐Seon , Kim Do‐Woo , Byun Hi‐Ryong 
Published: April 2009

AbstractThe change‐point analysis demonstrates that there is a regime shift in the spring precipitation in Korea in 1980–1981. The total spring precipitation in the years post‐1980 showed a distinct decrease compared to the years pre‐1980. This phenomenon of reduced spring precipitation was particularly dominant in the southwestern regions of the Sobaek Mountain range in Korea. This phenomenon was also noticed in China and Japan, excluding south China. One of the major causes for this decrease in spring precipitation was the increased snow depth in the mid‐latitude regions of continental East Asia. This resulted in a strengthened cold anticyclone over continental East Asia and a relatively weakened subtropical anticyclone over the western North Pacific, thus forcing a continuation of the typical winter pressure pattern of ‘high‐West and low‐East’ in East Asia from preceding winter into current spring. The strengthened northerlies from this zonal pressure pattern played a significant role in restricting the northern movement of the subtropical anticyclone and preventing the inflow of warm and humid air into Korea. Copyright © 2009 Royal Meteorological Society
Seasonal variations in polyphenols and lipoic acid in fruits of tomato irrigated with sea water
Authors: Incerti Annalisa , Navari‐Izzo Flavia , Pardossi Alberto , Izzo Riccardo 
Published: April 2009

AbstractBACKGROUND: Polyphenols and lipoic acid, due to their functions of antioxidant and free radical scavengers, are universally recognized as beneficial for preventing widespread human diseases, including cancer, and cardiovascular and cerebrovascular pathologies. In addition, they contribute to the determination of food taste and colour. These compounds were determined in tomato fruits (Solanum lycopersicum L., cv. Daniela) picked at red‐ripe stage during spring and autumn from tomato plants grown in rockwool slabs in a greenhouse in nutrient solutions with either groundwater or dilute sea water.RESULTS: Compared with groundwater, total phenolic acids, flavonoids and dihydrolipoic acid in tomato plants irrigated with sea water showed a decrease during spring and an increase during autumn. The interaction between sea water and season played a significant role in polyphenol and lipoic acid production.CONCLUSION: The consumption of polyphenols and lipoic acid is related to oxidative processes, which could be induced by natural physiological processes or more by environmental changes such as salinity or high irradiance. The lower presence of these antioxidants, observed in spring, may be a consequence of the more noxious levels of oxidative stress induced by the high salinity treatment when applied under a higher irradiance, typical conditions of spring in comparison to autumn. Copyright © 2009 Society of Chemical Industry
Assessment for fungal, mycotoxin and insect spoilage in maize stored for human consumption in Zambia
Authors: Kankolongo Muimba A , Hell Kerstin , Nawa Irene N 
Published: April 2009

AbstractBACKGROUND:Maize constitutes the main staple food and most important crop grown in Zambia. However, maize incurs considerable losses both in field and storage due to pathogens and insects. Some of the pathogens and resultant mycotoxins reduce the nutritional quality of the product. Mycotoxins are toxigenic fungal compounds that can cause cancer and suppress growth. In spite of this health hazard, there has been very little research to document their occurrence. Maize grains stored for human consumption were sampled from different agro‐ecosystems (forest, valley and plateau areas) of three agroecological zones (high, mid and low altitude).RESULTS:Several fungal genera were recovered among whichAspergillus flavus, A. niger, Fusarium verticillioides, F. solani, Rhizopus stoloniferandPenicilliumspp. were prevalent. The weevilSitophilus zeamaisand the larger grain borerProstephanus truncatuswere the most damaging. Enzyme‐linked immunosorbent assay (ELISA) tests yielded fumonisins and aflatoxins ranging between 0.02 and 21.44 ppm, and 0.7 and 108.39 ppb in 96.4% and 21.4% of samples, respectively. Fumonisin was more pronounced in villages in forest areas whereas aflatoxin was highest in valley and forest areas in Zone II.CONCLUSION:Strategic interventions to curtail fungal, mycotoxin and insect contamination should be directed towards improved agronomic and post‐harvest practices of maize from fields to consumers. Copyright © 2009 Society of Chemical Industry
Farmers' perception of environmental degradation and their adoption of improved management practices in Alxa, China
Authors: Wei Y. P. , Chen D. , White R. E. , Willett I. R. , Edis R. , Langford J. 
Published: April 2009

AbstractThe environment and the natural resource base have been severely degraded in Alxa League, western Inner Mongolia, China, over the past half‐century. This study reports surveys that reveal farmers' perceptions of environmental degradation and their adoption of improved management practices in this poor and remote desert region. Surveys were made in villages that had been engaged in a large environmental rehabilitation and management project [Alxa League environmental rehabilitation and management project (ALERMP)] and those that had not. The survey results showed that farmers perceived environmental degradation in terms of increased frequency and severity of sandstorms, movement of sand dunes, deterioration of pasture quality and declines in groundwater depth and quality. Farmers had low adoption rates for improved management practices, ranging from zero to a maximum of 28·5 per cent for the most adopted practice. A Tobit model analysis showed that the education level of farmers, the availability of extension services and whether farmers had participated in ALERMP were highly significantly correlated with the farmers' perception of degradation. The farmers' adoption of improved management practices was found to be significantly correlated only with whether they had participated in ALERMP. This shows that specific extension activities of the type possible in large and well‐funded projects are required if farmers are to recognise degradation and adopt improved management practices. The promotion of farmer education and strengthening of extension services are recommended as the best policy strategies for improving environmental management in this region. Copyright © 2009 John Wiley & Sons, Ltd.
Explicit polynomial preserving trace liftings on a triangle
Authors: Ainsworth Mark , Demkowicz Leszek 
Published: April 2009

AbstractWe give an explicit formula for a right inverse of the trace operator from the Sobolev space H1(T) on a triangle T to the trace space H1/2(∂T) on the boundary. The lifting preserves polynomials in the sense that if the boundary data are piecewise polynomial of degree N, then the lifting is a polynomial of total degree at most N and the lifting is shown to be uniformly stable independently of the polynomial order. Moreover, the same operator is shown to provide a uniformly stable lifting from L2(∂T) to H1/2(T). Finally, the lifting is used to construct a uniformly bounded right inverse for the normal trace operator from the space H(div; T) to H–1/2(∂T) which also preserves polynomials. Applications to the analysis of high order numerical methods for partial differential equations are indicated (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Extension of bounded vector‐valued functions
Authors: Frerick Leonhard , Jordá Enrique , Wengenroth Jochen 
Published: April 2009

AbstractIn this paper we consider extensions of bounded vector‐valued holomorphic (or harmonic or pluriharmonic) functions defined on subsets of an open set Ω ⊂ ℝN. The results are based on the description of vector‐valued functions as operators. As an application we prove a vector‐valued version of Blaschke's theorem (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On some local property of the shape of interfaces for the porous media equation
Authors: Hayasida Kazuya 
Published: April 2009

AbstractWe consider the porous media equation with absorption for various conditions and prove that the shape of ist interface never becomes strongly upward convex. For this sake we derive an improperly posed estimate for solutions of the porous media equation for the non‐characteristic Cauchy problem (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Decomposition for Morrey type Besov–Triebel spaces
Authors: Wang Henggeng 
Published: April 2009

AbstractIn this paper, the author establishes the decomposition of Morrey type Besov–Triebel spaces in terms of atoms and molecules concentrated on dyadic cubes, which have the same smoothness and cancellation properties as those of the classical Besov–Triebel spaces. The results extend those of M. Frazier, B. Jawerth for Besov–Triebel spaces and those of A. L. Mazzucato for Besov–Morrey spaces (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
1H NMR discrimination of CHF4226.01 diastereoisomers in DMSO‐d6
Authors: Capacchi Silvia , Lipreri Milco , Rizzi Andrea , Caló Claudia , Peveri Tiziana , Catinella Silvia 
Published: April 2009

AbstractTwo diastereoisomers CHF4226.01 (R, R) and CHF4232.01 (S, R), differing for a chiral center, have been studied to investigate their possible discrimination using NMR. 1D NMR and 2D NMR experiments, such as COSY, NOESY and ROESY, were performed on pure isomers and on the association complexes formed in the presence of the chiral reagent (S)‐(−)‐1‐(2‐napthyl)ethylamine (S‐NEA). Moreover, computational studies, concerning conformational analysis and molecular dynamics, were started and supported the NMR results. Copyright © 2009 John Wiley & Sons, Ltd.
T2 relaxation measurement with solvent suppression and implications to solvent suppression in general
Authors: Hoffmann Markus M. , Sobstyl Hanna S. , Badali Vincent A. 
Published: April 2009

AbstractA number of suppression pulse sequences including Excitation Sculpting and WATERGATE were incorporated into the standard Carr‐Purcell‐Meiboom‐Gill (CPMG) program for T2 measurement and experimentally evaluated. The chosen suppression schemes were of varying complexity encompassing pulse program elements, such as presaturation, gradients, and selective pulses, which are typically utilized for solvent suppression. The quality of the spectral data and the accuracy of T2 measurements of the investigated suppression schemes were evaluated using three aqueous samples with increasing proton content in the water solvent, i.e. by volume 100% D2O, 80/20% D2O/H2O, and 20/80% D2O/H2O. For signals removed from the water signal, the T2 values were generally very consistent between all pulse sequences tested. T2 measurements can be unreliable for signals too close to the water signal such that they are significantly suppressed as well. Their intensity may actually grow initially through cross relaxation that transfers magnetization back to the solute signal. In turn, this relaxation phenomenon can be exploited to improve the spectral quality of conventional solvent suppression schemes. In favorable cases, even signals that are completely masked by the water signal can be recovered by adding a carefully chosen number of spin echoes with optimized evolution time to conventional water suppression pulse programs, such as Excitation Sculpting or WATERGATE. Copyright © 2009 John Wiley & Sons, Ltd.
Hyperelastic modelling of small‐strain stiffness anisotropy of cyclically loaded sand
Authors: Gajo A. 
Published: April 2009

AbstractExperimental evidence shows that soil stiffness at very small strains is strongly anisotropic and depends on the stress level and void ratio. In particular, stiffness anisotropy varies considerably in sand when subjected to cyclic loading, following the stress cycles applied. To model this behaviour, an innovative hyperelastic formulation based on the elastoplastic coupling is incorporated in a new kinematic hardening elastoplastic model. The proposed hyperelastic–plastic model is the first to be capable of correctly simulating all aspects of the small‐strain behaviour of granular materials subjected to monotonic and cyclic loads. This hyperelastic formulation is generally applicable to any elastoplastic model. Copyright © 2009 John Wiley & Sons, Ltd.
The clinical and urodynamic results of a 3‐month percutaneous posterior tibial nerve stimulation treatment in patients with multiple sclerosis‐related neurogenic bladder dysfunction
Authors: Kabay Sahin , Kabay Sibel Canbaz , Yucel Mehmet , Ozden Hilmi , Yilmaz Zahide , Aras Ozgen , Aras Bahar 
Published: April 2009

AbstractAimThe aim of this study was to investigate the effect of PTNS after 12 weeks, on the urodynamic findings in the Multiple Sclerosis (MS) patients with neurogenic detrusor overactivity (NDO).MethodsA total of 19 MS patients with NDO were enrolled in the study. Urodynamic studies before and after 12 weeks PTNS were performed. PTNS was applied unilaterally from the medial malleolus and posterior to the edge of the tibia by using charge‐compensated 200 µs pulses with a pulse rate of 20 Hz, weekly, during 3 months. The effects of PTNS on urodynamic variables were compared of baseline and after PTNS data in MS patients.ResultsMean volume at the first involuntary detrusor contraction (1st IDCV) on standard cystometry was 124.2±37.6 ml, while it was 217.5±66.4 mL after PTNS. Mean maximum cystometric capacity (MCC) on standard cystometry was 199.7±29.3 mL, while it was 266.8±36.9 mL after stimulation. The improvements in the 1st IDCV and MCC were statistically significant after stimulation. Mean Pdetmax at first involuntary detrusor contraction, maximal detrusor pressure at maximum cystometric capacity, detrusor pressure at maximal flow (PdetQmax) and maximal flow rate (Qmax) were statistically significant after PTNS for 12 weeks.ConclusionsThese results have demonstrated that PTNS is effective to suppress NDO in MS patients after PTNS. Although long‐term efficacy of PTNS is known, the findings showed prominent improvements on the clinical and urodynamic outcome, we think that the use of PTNS for DO in MS patients will be promising in clinical practice in the future. Neurourol. Urodynam. 28:964–968, 2009. © 2009 Wiley‐Liss, Inc.
Deterrence, technology, and the sensible distribution of arms control verification resources
Authors: Avenhaus Rudolf , Canty Morton J. 
Published: April 2009

AbstractFor routine inspections in the frame of arms control, we address the determination of a rational basis for the distribution of available verification resources among controlled States. The analysis is performed primarily in the context of the nonproliferation treaty. In the spirit of this treaty, which in its original conception stressed objectivity, we adopt a formal, quantified point of view applying the theory of n‐person noncooperative games. Emphasis is placed on the conditions necessary for fulfillment of the fundamental verification objective of deterring illegal behavior, and reasonable and intuitively understandable conclusions are derived. © 2009 Wiley Periodicals, Inc. Naval Research Logistics 58: 295–303, 2011
Recommended use of insulin in type 1 diabetes in children
Authors: Johnston Philip , Flanagan Nuala , Carson Dennis , Bell Patrick 
Published: April 2009

AbstractOur series Prescribing in children gives practical advice for successful management of childhood problems in general practice. Here, the authors describe the management of type 1 diabetes with insulin and briefly discuss the use of oral hypoglycaemic agents in type 2 diabetes. Copyright © 2009 Wiley Interface Ltd
Surface morphology of zinc oxide nanorods grown by hydrothermal deposition technique
Authors: Hari Parameswar , Spencer Daryl 
Published: April 2009

AbstractZinc oxide (ZnO) nanorods grown by hydrothermal techniques are of great interest in photonic and electronic device applications because they offer low cost, low temperature deposition techniques compared to conventional molecular beam vapor deposition and sputtering methods. Our studies of ZnO nanorods grown by hydrothermal technique on indium tin oxide (ITO) coated glass substrates at 90 °C for 9 hours resulted in uniform growth of hexagonally shaped closed nanorod structures. We used scanning electron microscopy (SEM) to map changes in surface morphology of ZnO nanorods grown on various substrates. In this work we investigated the effects of temperature and the choice of conductive substrate on the size and shape of ZnO nanorods grown by hydrothermal growth. In particular, we studied the changes in surface morphology of ZnO nanorods deposited on ITO, ZnO coated glass, Aluminum coated glass, conducting transparent oxide (CTO) glass and mylar substrates. We will present quantitative data on changes in diameter and shape of ZnO nanorods as the growth substrate is varied. We will also discuss the surface morphology of ZnO nanorods grown by hydrothermal techniques at 95 °C on ZnO thin film substrate fabricated by sputter coating of ZnO on glass substrate. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electroluminescence analysis of 1.3‐1.5 μm InAs quantum dot LEDs with (Ga,In)(N,As) capping layers
Authors: Montes M. , Hierro A. , Ulloa J. M. , Guzmán A. , Khalfioui M. Al , Hugues M. , Damilano B. , Massies J. 
Published: April 2009

AbstractThe electroluminescence (EL) of a series of InAs/(Ga,In)(N,As) self‐assembled quantum dot light emitting diodes (QDLEDs) with different capping layer composition is analysed. Room temperature EL close to 1.5 μm is demonstrated using 15% In and 2% N in the capping layer. The origin of the different peaks present in the EL spectra of N‐containing devices has been studied and the higher energy peaks have been attributed to emission from the quantum well constituted by the wetting and the capping layers. The effect of rapid thermal annealing (RTA) on the EL is analysed. It is found that the EL emission energy blue‐shifts after RTA. This blue‐shift is smaller for the N‐containing devices (∼40 meV) than for a InAs/In0.15Ga0.85As reference QDLED (∼85 meV). In addition, the QDLEDs power slope efficiency is also studied at 14 K. It is readily seen that this efficiency decreases by three orders of magnitude with the addition of 2% N to the InGaAs capping layer. Nevertheless, after RTA, this efficiency recovers partially, increasing by two orders of magnitude and reaching values close to those of the N‐free reference QDLEDs. This enhancement can be explained by the reduction of the non‐radiative recombination centre density in the capping layer after RTA, which leads to a higher carrier injection efficiency into the QDs. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical Kerr signals of GaAs/AlAs multilayer cavities for a short pulse
Authors: Morita Ken , Kanbara Toshiyuki , Yano Shinsuke , Kitada Takahiro , Isu Toshirou 
Published: April 2009

AbstractOptical Kerr signals of GaAs/AlAs multilayer cavities with various quality factor (Q) were measured by an optical pump and probe technique with ultrashort pulses. Although the light intensity is enhanced in the cavities by Q, light power is restricted by the narrower spectrum of the cavity mode than that of the input ultrashort pulse. The measured Kerr signals showed larger dependence on the quality factor than that expected by simple consideration for the field enhancement effect by cavities. It seems that the nonlinear phase shift in the cavity is enhanced by the photon life time in addition to the field enhancement. This indicates that multilayer cavities are useful for enhancement of the optical Kerr signals. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)