bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microwave‐assisted Cadogan reaction for the synthesis of 2‐aryl‐2H‐indazoles, 2‐aryl‐1H‐benzimidazoles, 2‐carbonylindoles, carbazole, and phenazine
Authors: Creencia Evelyn Cuevas , Kosaka Masahiro , Muramatsu Toshikatsu , Kobayashi Masashi , Iizuka Tomohiro , Horaguchi Takaaki 
Published: November 2009

Abstract
magnified image The Cadogan reaction, a widely accepted route for the synthesis of nitrogen containing heterocycles, is modified by using microwave radiation as the source of heat instead of the conventional heating by reflux in a nitrogen atmosphere for several hours. Appropriate starting materials were mixed with triethyl phosphite or triphenylphosphine and irradiated with microwaves for several minutes at a specific power to give the desired products. The indazoles were prepared by irradiating N‐(2‐nitrobenzylidene) anilines with triethyl phosphite at 200 W for 12–14 min to give 85–92% product yields. Irradiation of the mixture of N‐benzylidene‐2‐nitroanilines and triphenylphosphine at 200 W for 3–5 min yielded 93–96% of the benzimidazoles. The carbonylindoles were obtained in 61–68% yields by irradiating 2‐nitrochalcone or alkyl 2‐nitrocinnamates and triphenylphosphine with microwaves at 80–200 W for 8–11 min. The mixture of 2‐nitrobiphenyl and triphenylphosphine yielded 96% of carbazole when irradiated with microwaves at 200 W for 2 min while 75% of phenazine was obtained by irradiating the mixture of 2‐nitrodiphenylamine and triphenylphosphine with microwaves at 200 W for 3.5 min. These results show that microwave‐assisted Cadogan reactions gave better product yields at shorter reaction times. J. Heterocyclic Chem., (2009).
Variability of water quality in a riparian wetland with interacting shallow groundwater and surface water
Authors: Schmalz Britta , Springer Pina , Fohrer Nicola 
Published: November 2009

AbstractLowland catchment hydrology is dominated by shallow groundwater with complex interactions between groundwater and surface water. In lowland catchments of N Germany, a high fraction of agricultural land is drained and therefore influenced by fast water transport to discharge systems with resulting alterations to water quality. The investigated catchment area “Kielstau” (approx. 50 km2) in the N of Schleswig‐Holstein serves as an example. Detailed investigations on the interactions between groundwater, river, and ditch‐water quality were evaluated at a drained riparian wetland area (0.15 km2) used as grassland in the central part of this catchment. The water quality in the drainage ditches showed variability dependent on their hydrological integration. At the far‐from‐river end, groundwater and ditch‐water quality were in most parameters much more alike than at the close‐to‐river end. The composition of ditch water at the close‐to‐river end of the ditch was determined by transformation processes and dilution which took place along the ditch much more than exfiltration processes like those that were dominant at the far‐from‐river end. In most cases, the mean NH$ _4^+ $ concentrations were higher in the groundwater than in the ditches, but the highest concentrations were found all along the time in the close‐to‐river sampling points and in the river. The highest NO$ _3^- $ concentration was observed in a ditch influenced by an adjacent arable field as well as in the river. The concentrations of phosphate and total P were lower in groundwater than in the ditch water.
Biogeochemical interfaces in soil: The interdisciplinary challenge for soil science
Authors: Totsche Kai U. , Rennert Thilo , Gerzabek Martin H. , Kögel‐Knabner Ingrid , Smalla Kornelia , Spiteller Michael , Vogel Hans‐Jörg 
Published: November 2009

AbstractSoil, the “Earth's thin skin” serves as the delicate interface between the biosphere, hydrosphere, atmosphere, and lithosphere. It is a dynamic and hierarchically organized system of various organic and inorganic constituents and organisms, the spatial structure of which defines a large, complex, and heterogeneous interface. Biogeochemical processes at soil interfaces are fundamental for the overall soil development, and they are the primary driving force for key ecosystem functions such as plant productivity and water quality. Ultimately, these processes control the fate and transport of contaminants and nutrients into the vadose zone and as such their biogeochemical cycling. The definite objective in biogeochemical‐interface research is to gain a mechanistic understanding of the architecture of these biogeochemical interfaces in soils and of the complex interplay and interdependencies of the physical, chemical, and biological processes acting at and within these dynamic interfaces in soil. The major challenges are (1) to identify the factors controlling the architecture of biogeochemical interfaces, (2) to link the processes operative at the individual molecular and/or organism scale to the phenomena active at the aggregate scale in a mechanistic way, and (3) to explain the behavior of organic chemicals in soil within a general mechanistic framework. To put this in action, integration of soil physical, chemical, and biological disciplines is mandatory. Indispensably, it requires the adaption and development of characterization and probing techniques adapted from the neighboring fields of molecular biology, analytical and computational chemistry as well as materials and nano‐sciences. To shape this field of fundamental soil research, the German Research Foundation (DFG) has granted the Priority Program “Biogeochemical Interfaces in Soil”, in which 22 individual research projects are involved.
Xylan‐Based Nanoparticles: Prodrugs for Ibuprofen Release
Authors: Daus Stephan , Heinze Thomas 
Published: November 2009

AbstractEsterification of xylan with ibuprofen via activiation of the carboxylic acid with N,N′‐carbonyldiimidazole (CDI) yields products of high drug loadings. Subsequent sulfation of xylan ibuprofen esters using the gentle agent SO3/DMF was successfully carried out in order to modify hydrophobicity of the xylan esters. The structure of the novel xylan esters was evaluated by means of NMR spectroscopy. The resulting xylan derivatives self assemble into spherical nanoparticles with mean diameters ranging from 162 to 472 nm. Preliminary stability measurements indicate that hydrolytic stability decreases with increase in degree of substitution of sulfate groups. Thus, a new concept toward improved drug delivery from polysaccharide‐based nanoparticles can be established here.magnified image
Electrochemical impedance spectroscopy investigation of chlorinated rubber‐based coatings containing polyaniline as anticorrosion agent
Authors: Baldissera A. F. , Freitas D. B. , Ferreira C. A. 
Published: November 2009

AbstractCorrosion protection of mild steel by a newly developed chlorinated rubber (CR)‐based coating system containing the inherently conductive polymer polyaniline (PAni) as an anticorrosion agent was studied. The synthesis of PAni and preparation of CR‐based paint containing this polymer are described herein. The corrosion behavior of mild steel samples coated with a CR resin, CR/PAni‐EB (emeraldine base), CR/PAni‐ES (emeraldine salt), and CR/DBSA‐doped PAni were investigated in 3.5% NaCl solution. For this purpose, electrochemical impedance spectroscopy and corrosion potential versus time measurements were utilized. It was found that the addition of the two forms of PAni, doped and undoped, to the CR resin increased its corrosion protection efficiency.
Electrochemical corrosion of silicon carbide ceramics
Authors: Sydow U. , Schneider M. , Herrmann M. , Kleebe H.‐J. , Michaelis A. 
Published: November 2009

AbstractRecently, SiC‐based ceramics have been found to exhibit corrosion damage patterns, which can only be explained by electrochemical processes. Therefore, the current work focusses on the electrochemical test procedures to determine the corrosion behaviour of solid state sintered silicon carbide (SSiC) ceramics in acidic and alkaline media. The corrosion current densities have been determined from linear voltammetric scans. At anodic polarization potentials, electrochemically induced etching patterns were observed in alkaline solution. The formation of pores and crevices during electrochemical oxidation in acidic solution could be monitored by field emission scanning electron microscopy (FESEM) in addition to transmission electron microscopy (TEM). Impedance spectra measured after anodic polarization could be described by the assumption of a pore model equivalent circuit.
Adsorption rate and protective effect of tributyl(cyclohexyl)ammonium chloride inhibitor on the acidic corrosion of steel
Authors: Magerramov A. M. , Rzayev Z. M. O. , Aliyev I. A. , Khalilova F. I. 
Published: November 2009

AbstractThe inhibition of corrosion of a steel surface by an inhibitor, tributyl(cyclohexyl)ammonium chloride (TBCA), was investigated by gravimetric and electrochemical polarization measurements in various aqueous solutions of HCl and H2SO4 acids. It is known that the most extensive corrosive destruction proceeds during the initial stage of contact between the metallic surface and the aggressive surroundings. The change from H2SO4 to HCl considerably decreases the time for formation of an adsorption layer. The high adsorption of the surface‐active cationic TBCA on the steel electrode surface can be explained by the specific adsorption of Cl− anions increasing the negative charge on the electrode surface. It was observed that the value of the polarizing current can be increased from time to time by addition of more TBCA inhibitor. This fact can be explained by the low stability of the film‐forming layer on the steel. A similar decrease of the protective effect was also observed in HCl solution. The inhibitor provides at least a slowing of the corrosion process (τ = 21 min). It was found that an increase in H2SO4 concentration from 1.0 to 0.2 N did not change the protective action of the inhibitor and had rather high values (θ = 283 ma/h, ψ = 84%, and τ = 14 min at [I] = 3.5 × 10−4 mol/L). It was shown that the attraction constant has a negative value (A = −1.5 and Ka = 22.3) for the inhibitor, which relates to a high value for the adsorption ability of TBCA in HCl solution and therefore with the intermolecular repulsive force between adsorption molecules having similar charges. The protective action of TBCA increases with an increase in temperature, which is correlated with the chemical nature of its adsorption on the steel surface.
Historic Account of the Development in the Understanding of the Propagation Kinetics of Acrylate Radical Polymerizations
Authors: van Herk Alex M. 
Published: November 2009

AbstractAcrylates and methacrylate polymers are widely used in a variety of applications such as coatings, adhesives, and synthetic rubbers. In a continuous effort to increase the understanding and control over the radical (co)polymerizations of acrylate monomers the kinetic parameters, such as the propagation and termination rate constants, need to be determined. In particular, the propagation rate coefficients of the family of acrylate monomers have been a topic of intense scientific study over the last 10 years or so. In the last decade an almost full understanding of the complicated aspects of acrylate radical polymerizations has been established. It is the purpose of this essay to give a short historic account of the developments in this understanding of acrylate radical polymerizations.magnified image
Online real‐time reconstruction of adaptive TSENSE with commodity CPU/GPU hardware
Authors: Roujol Sébastien , de Senneville Baudouin Denis , Vahala Erkki , Sørensen Thomas Sangild , Moonen Chrit , Ries Mario 
Published: November 2009

AbstractAdaptive temporal sensitivity encoding (TSENSE) has been suggested as a robust parallel imaging method suitable for MR guidance of interventional procedures. However, in practice, the reconstruction of adaptive TSENSE images obtained with large coil arrays leads to long reconstruction times and latencies and thus hampers its use for applications such as MR‐guided thermotherapy or cardiovascular catheterization. Here, we demonstrate a real‐time reconstruction pipeline for adaptive TSENSE with low image latencies and high frame rates on affordable commodity personal computer hardware. For typical image sizes used in interventional imaging (128 × 96, 16 channels, sensitivity encoding (SENSE) factor 2‐4), the pipeline is able to reconstruct adaptive TSENSE images with image latencies below 90 ms at frame rates of up to 40 images/s, rendering the MR performance in practice limited by the constraints of the MR acquisition. Its performance is demonstrated by the online reconstruction of in vivo MR images for rapid temperature mapping of the kidney and for cardiac catheterization. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
High‐resolution magnetic resonance angiography in the mouse using a nanoparticle blood‐pool contrast agent
Authors: Howles Gabriel P. , Ghaghada Ketan B. , Qi Yi , Mukundan Srinivasan , Johnson G. Allan 
Published: November 2009

AbstractHigh‐resolution magnetic resonance angiography is already a useful tool for studying mouse models of human disease. Magnetic resonance angiography in the mouse is typically performed using time‐of‐flight contrast. In this work, a new long‐circulating blood‐pool contrast agent—a liposomal nanoparticle with surface‐conjugated gadolinium (SC‐Gd liposomes)—was evaluated for use in mouse neurovascular magnetic resonance angiography. A total of 12 mice were imaged. Scan parameters were optimized for both time‐of‐flight and SC‐Gd contrast. Compared to time‐of‐flight contrast, SC‐Gd liposomes (0.08 mmol/kg) enabled improved small‐vessel contrast‐to‐noise ratio, larger field of view, shorter scan time, and imaging of venous structures. For a limited field of view, time‐of‐flight and SC‐Gd were not significantly different; however, SC‐Gd provided better contrast‐to‐noise ratio when the field of view encompassed the whole brain (P < 0.001) or the whole neurovascular axis (P < 0.001). SC‐Gd allowed acquisition of high‐resolution magnetic resonance angiography (52 × 52 × 100 micrometer3 or 0.27 nL), with 123% higher (P < 0.001) contrast‐to‐noise ratio in comparable scan time (∼45 min). Alternatively, SC‐Gd liposomes could be used to acquire high‐resolution magnetic resonance angiography (0.27 nL) with 32% higher contrast‐to‐noise ratio (P < 0.001) in 75% shorter scan time (12 min). Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Neuromuscular diseases associated with HIV‐1 infection
Authors: Robinson‐Papp Jessica , Simpson David M. 
Published: November 2009

AbstractNeuromuscular disorders are common in human immunodeficiency virus (HIV); they occur at all stages of disease and affect all parts of the peripheral nervous system. These disorders have diverse etiologies including HIV itself, immune suppression and dysregulation, comorbid illnesses and infections, and side effects of medications. In this article, we review the following HIV‐associated conditions: distal symmetric polyneuropathy; inflammatory demyelinating polyneuropathy; mononeuropathy; mononeuropathy multiplex; autonomic neuropathy; progressive polyradiculopathy due to cytomegalovirus; herpes zoster; myopathy; and other, rarer disorders. Muscle Nerve, 2009
Developing reference data for nerve conduction studies: An application of quantile regression
Authors: Peng Limin , Wuu Joanne , Benatar Michael 
Published: November 2009

AbstractIntroduction: The interpretation of nerve conduction studies, as with any diagnostic test, requires an ability to differentiate normal from abnormal. To this end there have been many efforts to establish reference or normative data, but they have been hampered by a variety of methodological shortcomings. The goal of this article is to introduce a statistical method known as quantile regression, which we contend is better suited than existing methods to generate reference data, especially when there is a need to adjust for covariates. Methods: Statistical methods previously used for generation of reference data are reviewed. Quantile regression is presented and used to estimate the lower percentiles for response amplitudes of the radial sensory and tibial motor nerves. Results: Using data from 190 subjects, it is possible to estimate as low as the 2nd percentile for the radial nerve. Using data from 99 subjects it is possible to estimate as low as the 4th percentile for the tibial nerve. Percentile estimation for both nerves required adjustment for age, but no other covariates. Discussion: Quantile regression is well suited to the estimation of extreme percentiles, the very percentiles that are most relevant to reference data. It is also less dependent on data distribution and permits covariate adjustment, even for continuous variables such as age, which are clinically important determinants of reference data for nerve conduction studies. We recommend the use of quantile regression for future studies of reference data. Muscle Nerve 40: 763–771, 2009
Reference data for commonly used sensory and motor nerve conduction studies
Authors: Benatar Michael , Wuu Joanne , Peng Limin 
Published: November 2009

AbstractIntroduction: The goal of this study was to generate reference data for a wide range of sensory and motor nerve conduction studies (NCSs) that are commonly used in routine electrodiagnostic practice. Methods: NCS data were collected from control subjects with a normal neurological examination and no known risk factors for or symptoms to suggest disease of the peripheral nervous system. Thirteen sensory and motor nerves were studied in the upper and lower limbs using standard recording techniques. Quantile regression was used to obtain estimates of the lower (e.g., 5th) percentiles for sensory and motor amplitudes and conduction velocities, as well as estimates of the upper (e.g., 95th) percentiles for distal motor latency and F‐wave latencies. Results: Reference data for sensory and motor amplitudes required adjustment for age; F‐wave latencies required adjustment for gender. Covariate adjustments were not required for other reference data. Data from N = 100 and N = 190 subjects permitted estimation of as low as the 4th and 2nd percentile, respectively, but further increases to N = 296 did not permit estimation of a more extreme percentile. Discussion: Efforts to develop reference data require careful selection of study subjects; sufficient sample size; adjustment for relevant covariates; and appropriate statistical methods for analysis. Reference data that cannot be estimated reliably due to absent potentials or data variability must be interpreted with caution. We present data for a range of clinically applicable reference percentiles, but judgment regarding which is most appropriate for diagnostic purpose awaits empiric evaluation in a disease population. Muscle Nerve 40: 772–794, 2009
”Nicht den Zug verpassen“
Authors: Bulmahn Maren , Guggolz Ernst 
Published: November 2009

AbstractOb — und wenn ja, welche — Spezialchemikalien in Zukunft in Saudi‐Arabien mit Gewinn produzierbar sind, berichtet Hubert Bader, Partner bei Chemadvice in den Nachrichten aus der Chemie.
Die Farbe der Tonkrieger: Eine Aufgabe für die Chemie
Authors: Langhals Heinz 
Published: November 2009

AbstractDie Terrakotta‐Armee, welche die Grabstätte des ersten chinesischen Kaisers Qin Shihuangdi bewacht, gehört zu den größten archäologischen Funden überhaupt. Ihre Restaurierung ist mit etablierten Methoden kaum zu beherrschen und erfordert neue chemische Wege und oft unkonventionelle Methoden, etwa bei der Konservierung der Farbschichten der Terrakotta‐Figuren.
Performance evaluation of a 32‐element head array with respect to the ultimate intrinsic SNR
Authors: Lattanzi Riccardo , Grant Aaron K. , Polimeni Jonathan R. , Ohliger Michael A. , Wiggins Graham C. , Wald Lawrence L. , Sodickson Daniel K. 
Published: November 2009

AbstractThe quality of an RF detector coil design is commonly judged on how it compares with other coil configurations. The aim of this article is to develop a tool for evaluating the absolute performance of RF coil arrays. An algorithm to calculate the ultimate intrinsic signal‐to‐noise ratio (SNR) was implemented for a spherical geometry. The same imaging tasks modeled in the calculations were reproduced experimentally using a 32‐element head array. Coil performance maps were then generated based on the ratio of experimentally measured SNR to the ultimate intrinsic SNR, for different acceleration factors associated with different degrees of parallel imaging. The relative performance in all cases was highest near the center of the samples (where the absolute SNR was lowest). The highest performance was found in the unaccelerated case and a maximum of 85% was observed with a phantom whose electrical properties are consistent with values in the human brain. The performance remained almost constant for 2‐fold acceleration, but deteriorated at higher acceleration factors, suggesting that larger arrays are needed for effective highly‐accelerated parallel imaging. The method proposed here can serve as a tool for the evaluation of coil designs, as well as a tool to guide the development of original designs which may begin to approach the optimal performance. Copyright © 2009 John Wiley & Sons, Ltd.
Damage development in a noncrimp‐glass fabric reinforced epoxy composite material
Authors: Cruz‐Santos G. , Rodríguez‐Laviada J. , Rios‐Soberanis C.R. 
Published: November 2009

AbstractThe relationship between textile architecture and the damage sequence under tensile loading has been investigated experimentally for a composite material reinforced with a noncrimp glass‐fiber textile of configuration [0°, +45°, 90°, −45°] stacking sequence based on epoxy resin matrix cured with high‐temperature hardener. The system chosen for this work consists of a bifunctional epoxy, diglycidyl ether of bisphenol A, cured with a tetrafunctional amine, diaminodiphenyl sulfone (DDS). This system ensures to obtain a rigid material with excellent mechanical properties in order to observe, analyze, and identify the process and progress of the generated damage and the failure mechanism which leads to the materials fracture. The properties have been studied for each ply direction at 0°, +45°, 90°, and −45° in order to make a comparative assessment of the influence of the polyester (PES) yarns in zig‐zag and unidirectional geometry, that hold together the four plies in the textile, in the composite damage generation. The laminates were uniaxially tensile loaded until final fracture occurred. It was found that PES threads have an effect on cracking progression depending on the textile orientation. POLYM. COMPOS., 2009. © 2009 Society of Plastics Engineers
Exploring the process of becoming and working as a practice development unit
Authors: Bray Lucy , Brown Jeremy , Prescott Trish , Moen Charlotte 
Published: November 2009

AbstractThis study aimed to explore the perspective of multidisciplinary staff on the process of becoming and working as a practice development unit (PDU). PDUs are reported as positive initiatives within health care. It is important to understand the process of becoming a PDU and the ongoing effects of the process to the staff working within the unit. This project engaged with multidisciplinary staff working on six PDU units throughout the north‐west of England. Data collection was in two phases: a self‐completion questionnaire distributed to all staff within the PDUs (n = 625, 28.2% response rate) followed by 17 semi‐structured telephone interviews. The majority of questionnaire respondents (n = 114, 64%) indicated that they would recommend PDU accreditation to other units. The main themes arising from the project focus on accreditation having a positive influence on multidisciplinary team working, evidence‐based practice and improving opportunities for professional development. Issues were raised during the interviews regarding the increased development of staff leading to high turnover, the high workload involved in leading the accreditation and the inequitable involvement of professions in the process. Copyright © 2009 John Wiley & Sons, Ltd.