bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biotransformation of Ergot Alkaloids by Haloperoxidase from Streptomyces aureofaciens: Stereoselective Acetoxylation and Propionoxylation
Authors: Křen Vladimír , Kawuloková Libuše , Sedmera Petr , Polášek Miroslav , Lindhorst Thisbe K. , van Pée Karl‐Heinz 
Published: July 2007

AbstractAgroclavine (1) was oxidized, by haloperoxidase from Streptomyces aureofaciens, to 2,3‐dihydro‐6,8‐dimethyl‐3β‐acetoxy‐8‐ergolen‐2‐one (2) in the presence of sodium acetate and bromine ions. Acetate was incorporated into the above product during oxidation. In a propionate buffer, incorporation of propionate into the product was observed, yielding 2,3‐dihydro‐6,8‐dimethyl‐3β‐propionoxy‐8‐ergolen‐2‐one (4). The biotransformation proceeded faster in the propionate buffer, affording also the higher oxidation product (4aS),(10bS)‐7‐amino‐3,4,4a,5,6,10b‐hexahydro‐2,4‐dimethyl‐6‐oxobenzo[f]quinoline (3).
Addition and Cyclization Reactions in the Thermal Conversion of Hydrocarbons with an Enyne Structure, 5. High‐Temperature Ring Closures of 1,3‐Hexadien‐5‐ynes to Naphthalenes – Competing Reactions via Isoaromatics, Alkenylidene Carbenes, and Vinyl‐type Radicals
Authors: Hofmann Jörg , Schulz Kathrin , Altmann Annett , Findeisen Matthias , Zimmermann Gerhard 
Published: July 2007

AbstractThe 4‐substituted 1‐phenyl‐1‐butene‐3‐ynes 1a–c and the 2‐ethynylstyrenes 7a–c were subjected to high‐temperature pyrolysis. The cycloisomerization products isolated suggest that these are formed by three competing processes: by (i) an electrocyclic or a molecule‐induced, (ii) an alkenylidene carbene controlled, and (iii) a radical‐controlled ring‐closure process. To estimate the relative importance of these three reactions here mentioned, the substrates have been isomerized in oxygen‐free nitrogen and in nitrogen proportionally substituted by toluene at 700 and 650 °C, respectively. The relative contributions of these isomerizations depend not only on the conversion temperature but also on the substitutent R in 1 or 7.
Assessment of myocardial oxygen extraction fraction and perfusion reserve with BOLD imaging in a canine model with coronary artery stenosis
Authors: Zhang Haosen , Gropler Robert J. , Li Debiao , Zheng Jie 
Published: July 2007

AbstractPurposeTo determine the feasibility of T2‐weighted BOLD imaging for estimating regional myocardial oxygen extraction fraction (OEF) and approximating perfusion reserve (MPR) simultaneously in a canine model with moderate coronary artery stenosis.Materials and MethodsEight mongrel dogs with moderate coronary artery stenosis underwent BOLD imaging at rest and during dipyridamole‐induced hyperemia, using a turbo spin echo (TSE) sequence. Based on a two‐compartment model, myocardial OEFhyperemia was calculated with the corresponding T2. MPR could be approximated based on Fick's law.ResultsDuring responsive hyperemia, a regional hypointensity was observed in the abnormally perfused myocardium, reflecting a relatively smaller myocardial T2 increase (3.06% ± 2.74%, in contrast to 10.19% ± 4.12% in the normal region). The average OEFs in the normally and abnormally perfused myocardial territories were 0.21 ± 0.11 and 0.43 ± 0.12, respectively. For the MPR approximated from the BOLD imaging, a strong correlation (R = 0.9) in the normal myocardium and a good correlation (R = 0.6) distal to the stenosis were obtained compared to microsphere results.ConclusionIn a canine model with moderate coronary artery stenosis, TSE‐based BOLD imaging can quantitatively estimate the regional OEFhyperemia and approximate the MPR, and can distinguish segments perfused by defected coronary artery. J. Magn. Reson. Imaging 2007;26:72–79. © 2007 Wiley‐Liss, Inc.
Phosphorus indices as risk‐assessment tools in the U.S.A. and Europe—a review
Authors: Buczko Uwe , Kuchenbuch Rolf O. 
Published: July 2007

AbstractThe “phosphorus index” (PI) is a semiquantitative tool to assess the risk of P loss from fields to surface waters, which is based on simple arithmetic computations of source (soil test phosphorus (STP), P applications as manure and fertilizer, plant residues) and transport factors (erosion, surface runoff, subsurface drainage, connectivity). Work done since the 1990s in the U.S.A. and several European countries has shown that this approach is capable of delineating critical source areas for P export within a watershed. It is intended to adopt such a PI tool in Germany as well. However, there is no “standard” PI, and the variety of P indices is confusing, since each state and country has developed its own version to account for special regional conditions which are important for P loss. This paper reviews the factors of P loss which are taken into account in P indices and different modifications of P indices according to their components and structural approach. The literature concerning single source and transport factors of P loss is overwhelming, and a structured selection is given in this review.Most P indices can be classed into one of three groups: 1. additive approach, 2. multiplicative approach, and 3. multiplicative‐additive approach.For Germany, it is suggested that specific factors of P loss are incorporated into the basic backbone of a Pennsylvania‐style PI. Realization of the factors could be adopted from existing Scandinavian P indices or from other research results.
Presence of indigestible peptide aggregates of soybean meal in pig ileal digesta residue
Authors: Fischer Morten , Voragen Alphons GJ , Piersma Sander R , Kofod Lene V , Joergensen Christian I , Guggenbuhl Patrick , Nunes Carlos S , Gruppen Harry 
Published: July 2007

AbstractWith the purpose of analysing the molecular size and composition, proteinaceous material was extracted from the insoluble components of a digesta sample obtained from pigs fed a feed consisting of only soybean meal. Gel permeation chromatography indicated that the alkali‐extractable fraction of the proteinaceous material from the residue was of relatively high apparent molecular weight. However, the combined results from gel electrophoresis, RPLC‐MS, and MALDI‐ToF MS showed that the extracted protein material was in fact, to a high extent, composed of aggregated peptides. To our knowledge this has not previously been described. Aggregates extracted by dilute alkali were fully degraded upon subsequent proteolytic treatment. N‐terminal sequencing of selected protein bands from SDS‐PAGE gels indicated the presence of partly degraded β‐conglycinin alpha subunits in the residue. Copyright © 2007 Society of Chemical Industry
Heat shock proteins 47 and 70 expression in rodent skin model as a function of contact cooling temperature: Are we overcooling our target?
Authors: Brown Spencer A. , Farkas Jordan P. , Arnold Christopher , Hatef Daniel A. , Kim Jane , Hoopman John , Kenkel Jeffrey M. 
Published: July 2007

AbstractBackground and ObjectivesThe degree of protective cooling required during laser therapy to achieve an optimal result is unknown. The expression of heat shock proteins, Hsp47 and Hsp70, were examined in the epidermis and dermis as biomarkers to quantify the degree and depth of tissue affected by non‐ablative laser treatment using variable protective cooling parameters.Study Design/Materials and MethodsTwenty‐one male Sprague–Dawley rats were treated with a 1,319 nm Nd:YAG laser using a sapphire cooling plate attached to the hand piece. A 4 cm×4 cm area on each side of the rat was treated with the same energy and pulse settings, with variable contact cooling. Protective cooling parameters, for each degree increment, ranging from 0 to 25°C were studied. Immunohistochemistry (IHC), Western blot and PCR were performed to evaluate the effects of superficial cooling on Hsp47, and Hsp70 expressions.ResultsOur data showed the extent of topical cooling needed to produce a thermal effect at different depths in the dermis, quantified by the expression of Hsp47 and Hsp70. Significant Hsp expression was observed with cooling of 13°C and warmer; no identifiable cellular reaction was observed when cooling below 5°C. There was no evidence of epidermal injury when treating the skin with any protective cooling ranging from 0 to 25°C.ConclusionOur data would suggest contact cooling temperatures 5°C and below completely protects through the entire dermis. There was no evidence of epidermal injury with protective cooling at any temperature between 0 and 25°C. Warmer temperatures are safe and adequately protect the epidermis in this model. Lasers Surg. Med. 39:504–512, 2007. © 2007 Wiley‐Liss, Inc.
Low‐intensity laser irradiation stimulates bone nodule formation via insulin‐like growth factor‐I expression in rat calvarial cells
Authors: Shimizu Noriyoshi , Mayahara Kotoe , Kiyosaki Takeshi , Yamaguchi Akikuni , Ozawa Yasuhiro , Abiko Yoshimitsu 
Published: July 2007

AbstractBackground and ObjectiveWe previously reported that low‐intensity laser irradiation stimulated bone nodule formation through enhanced cellular proliferation and differentiation. However, the mechanisms of irradiation are unclear. Thus, we attempted to determine the responsibility of insulin‐like growth factor (IGF)‐I for the action observed.Study Design/Materials and MethodsOsteoblast‐like cells were isolated from fetal rat calvariae and cultured with rat recombinant (r) IGF‐I, IGF‐I‐antibody (Ab), and/or the cells were irradiated once (3.75 J/cm2) with a low‐intensity Ga‐Al‐As laser (830 nm). The number and area of bone nodules formed in the culture were analyzed, and IGF‐I expression was also examined.ResultsTreatment with rIGF‐I significantly stimulated the number and area of bone nodules. This stimulatory effect was quite similar to those by laser irradiation, and this stimulation was abrogated dose‐dependently by treatment with IGF‐I‐Ab. Moreover, laser irradiation significantly increased IGF‐I protein and gene expression.ConclusionThe stimulatory effect of bone nodule formation by low‐intensity laser irradiation will be at least partly mediated by IGF‐I expression. Lasers Surg. Med. 39:551–559, 2007. © 2007 Wiley‐Liss, Inc.
Polymer/Laponite Composite Latexes: Particle Morphology, Film Microstructure, and Properties
Authors: Negrete‐Herrera Norma , Putaux Jean‐Luc , David Laurent , Haas Felix De , Bourgeat‐Lami Elodie 
Published: July 2007

AbstractTransparent film materials with excellent mechanical and thermal properties were elaborated by drying a latex suspension of armored polymer/Laponite composite particles. Low‐temperature TEM observation of ultrathin cross‐sections of the films indicated a unique network morphology characterized by a “honeycomb” distribution of the Laponite platelets remindful of the original particles morphology.magnified image
Sub‐Micrometer Sized Hairy Latex Particles Synthesized by Dispersion Polymerization Using Hydrophilic Macromolecular RAFT Agents
Authors: Bathfield Maël , D'Agosto Franck , Spitz Roger , Charreyre Marie‐Thérèse , Pichot Christian , Delair Thierry 
Published: July 2007

AbstractDispersion polymerization of n‐butyl acrylate has been performed in a mixture of ethanol and water in the presence of poly(N‐acryloylmorpholine) (polyNAM). These hydrophilic polymer chains are synthesized by the RAFT process and thus incorporate well‐defined chain ends. The dithioester ω‐end group is used as an efficient chain transfer agent under dispersion polymerization conditions to produce hairy poly(n‐butyl acrylate) latex particles. Moreover, pre‐functionalization of the polyNAM chains on the α‐end by a carbohydrate derivative is also achieved to obtain directly functionalized particles according to the same strategy.magnified image
Etiological musculo‐skeletal factor in focal dystonia in a musician's hand: A case study of the right hand of a guitarist
Authors: Leijnse Joris N.A.L. , Hallett Mark 
Published: July 2007

AbstractA case study is presented in which a focal hand dystonia seems to have developed in the right hand of a classical guitarist as a result of a neuromuscular peripheral defect caused by trauma. The trauma was a near total perforation of the first web space by a splinter. Healing was uneventful without apparent functional complications. Two years later the patient noticed difficulties in extending the index in playing, for which he received various unsuccessful treatments during seven years. However, we found more severe dystonic symptoms (cocontractions) in the thumb than in the index during playing, which correlated with an undiagnosed insufficiency in the flexor pollicis brevis (FPB). This defect allowed proposing a biomechanical analysis of compensations for diminished thumb control in playing, which would explain the dysfunction in the index in playing as overcompensation for the thumb problem. If this analysis is correct, the etiology of the case can be traced back to underlying multiarticular control problems in the thumb caused by an insufficient FPB. This defect was considered irrepairable. It was concluded that even with knowledge of the underlying cause, a potentially successful treatment of the dystonia might not exist in this case. The case would demonstrate that task‐specific hand dystonias can arise as overcompensations for (peripheral) neuro‐musculoskeletal defects. The case is illustrated by videos of playing and functional thumb tests. © 2007 Movement Disorder Society
Combining spin echoes with gradient echoes in the context of the global coherent free precession pulse sequence
Authors: Rehwald Wolfgang G. , Salerno Michael , Chen Enn‐Ling , Sievers Burkhard , Kim Raymond J. , Judd Robert M. 
Published: July 2007

AbstractTo extend the signal longevity of magnetically excited spins in flowing fluids while in a state of global coherent free precession (GCFP), a refocusing radiofrequency (RF) pulse and bipolar gradient waveforms were combined with the GCFP sequence. The data demonstrate that RF refocusing in the presence of flowing blood is possible, but the improvement in signal amplitude depends on the static magnetic field homogeneity along the direction of motion and the displacement of the spins between the excitation and the RF refocusing pulse, as well as displacement during subsequent RF refocusing pulses. The least amount of phase dispersion and thus the longest lasting signal is obtained with the shortest echo spacing where only one line of data is recorded between two RF refocusing pulses. This approach was successfully used in a phantom and in vivo to image fast and slow blood flow. Depending on the experimental conditions, signal persistence is improved significantly compared to playing the same sequence without RF refocusing, but the improvement is limited by the product of blood flow velocity and the time between RF refocusing pulses. Magn Reson Med 58:82–91, 2007. © 2007 Wiley‐Liss, Inc.
Modifying and managing the surface properties of polymers
Authors: Hutchings Lian R , Narrianen Amilcar Pillay , Thompson Richard L , Clarke Nigel , Ansari Imtiyaz 
Published: July 2007

AbstractAn ongoing challenge in polymer science is the preparation of materials with bespoke surface properties which differ from that of the bulk, for example hydrophobicity, wettability, chemical resistance, adhesion or biocompatibility. We highlight here recent efforts in the design, development and application of (multi)end‐functionalized polymers as additives for the efficient modification of polymer surface properties. Aryl‐ether moieties bearing up to eight functional groups have been used as initiators for the controlled polymerization of both styrene and methyl methacrylate by atom transfer radical polymerization (ATRP) and of lactide by ring opening polymerization (ROP). The resulting polymers have been used as additives to modify the surfaces of the corresponding bulk polymers. Fluorinated polymer surfaces are particularly appealing in terms of their liquid repellence, chemical inertness and low coefficient of friction. When an additive consisting of a low molecular weight polystyrene chain, end‐capped with four C8F17 groups, is present in a matrix of polystyrene at levels as low as 0.1%, near polytetrafluoroethylene‐like surface properties result. Copyright © 2007 Society of Chemical Industry
Enhancement of wettability in low density polyethylene films using low pressure glow discharge N2 plasma
Authors: Sanchis Rosa M. , Calvo Oscar , Sánchez Lourdes , García David , Balart Rafael 
Published: July 2007

AbstractLow pressure glow discharge nitrogen plasma has been used to improve wettability in a low density polyethylene (LDPE) film for technical applications. The plasma treatment was carried out at a power of 300 W for different exposure times in the 1–20 min range. Wettability changes were analyzed using contact angle measurements. In addition to this, plasma‐treated samples were subjected to an aging process to determine the durability of the plasma treatment. X‐ray photoelectron spectroscopy, atomic force microscopy, and scanning electron microscopy were used for surface characterization. The nitrogen plasma treatment considerably reduced contact angle values thus indicating an increase in surface wettability. The spectroscopic study showed presence of oxygen‐based species on the plasma‐treated samples, which are mainly generated after the plasma treatment as a consequence of air exposure. These polar species contribute to improve surface functionalization, but this is almost lost during aging due to the hydrophobic recovery process. Microscopic studies revealed that also small changes in surface roughness occurred during the plasma treatment but these are very low compared to surface activation. The results confirmed that low pressure nitrogen can be considered as an environmentally efficient process to improve wettability in low density polyethylene films. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2390–2399, 2007
Vapor‐induced spreading dynamics of adsorbed linear and brush‐like macromolecules as observed by environmental SFM: Polymer chain statistics and scaling exponents
Authors: Gallyamov Marat O. , Tartsch Bernd , Mela Petra , Potemkin Igor I. , Sheiko Sergei S. , Börner Hans , Matyjaszewski Krzysztof , Khokhlov Alexei R. , Möller Martin 
Published: July 2007

AbstractScaling exponents ν, that describe the correlation between mean square end‐to‐end distances and contour lengths of macromolecules, were determined by statistical analysis of scanning force micrographs of single linear poly(2‐vinylpyridine) and brush‐like poly(butanoate‐ethyl methacrylate)‐graft‐poly(n‐butyl acrylate) macromolecules adsorbed on mica. Using an atmosphere‐controlled scanning force microscope, single adsorbed molecules were collapsed and re‐expanded upon being exposed to alcohol and water vapor, respectively. This manipulated collapse‐unfolding was used to equilibrate the molecular structure/conformation. The in situ and real‐time scanning force microscopy analysis allows the scientist to quantitatively characterize end‐to‐end distances and contour lengths of the molecules directly on the image and to observe differences in the spreading dynamics for the two types of macromolecules. A distinct difference has been observed between the expanded two‐dimensional (2D) conformations of linear and brush‐like polymer chains. Whereas a scaling exponent ν of 0.73 was found for the expanded 2D conformation of the linear molecules, a ν‐value of 0.53 was determined for the expanded 2D conformation of the seemingly stiffer brush‐like molecules. A theoretical explanation of the differences between the 2D conformations of brush‐like and linear macromolecules is proposed here. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2368–2379, 2007
Porous SiOCH, SiCH and SiO2 Etching in High Density Fluorocarbon Plasma with a Pulsed Bias
Authors: Raballand Vanessa , Cartry Gilles , Cardinaud Christophe 
Published: July 2007

AbstractThe effect of radio frequency bias pulsing on porous SiOCH, SiCH and SiO2 etching using inductively coupled fluorocarbon plasmas was investigated. It was found that pulse frequency had only a small influence on material etch rates. However, pulse duty cycle, defined as the time during which a bias is applied over the total period, clearly modified etch rates and selectivities. Indeed, etch selectivities between porous SiOCH and SiCH or SiO2 were considerably improved when the duty cycle was decreased. This enhancement was associated with relatively high porous SiOCH etch rates, and pattern transfers under low duty cycle conditions proved to be successful. To better understand the pulse process, surface analysis was also realised. According to XPS analysis, the material surface structure was found to be similar after etching in continuous or in pulsed mode. However, fluorocarbon species on material surfaces were fluorine richer after etching in the pulsed mode.magnified image
Experimental Characterisation of the Plasma Absorption Probe
Authors: Scharwitz Christian , Böke Marc , Hong Suk‐Ho , Winter Jörg 
Published: July 2007

AbstractThe plasma absorption probe has been developed to provide a fast and efficient diagnostic tool for the characterisation of discharges, especially of reactive plasmas. Unlike Langmuir probes, the plasma absorption probe measures electron densities in reactive plasmas undisturbed by coatings of the probe surface. It consists of a semirigid coaxial cable with protruding inner conductor as an antenna, covered by a dielectric tube. The measurement principle is based on active resonance spectroscopy. A network analyser feeds the coaxial cable with HF of variable frequency and the power reflection spectrum is detected. At resonant frequencies, characteristic for the discharge, absorption signals are observed. In this paper, we present measurements of the plasma absorption probe for various discharge conditions and we evaluate the probes' further potential for the analysis of reactive plasmas.magnified image
Pulmonary testing using peak flow meters of very low birth weight children born in the perisurfactant era and school controls at age 10 years
Authors: Palta Mari , Sadek‐Badawi Mona , Madden Kathleen , Green Christopher 
Published: July 2007

AbstractWe determined lung function at age 10 years in very low birthweight (VLBW, ≤1,500 g) children and controls, and compared the sensitivity to detect subgroup differences by peak expiratory flow (PEF), forced expiratory volume in one second (FEV1), forced vital capacity (FVC) and their diurnal variation. VLBW children were recruited across the perisurfactant era at admission to six NICUs in Wisconsin and Iowa, and controls from area classrooms. Two hundred sixty five VLBW children and 360 controls were tested by the Jaeger AM1 peak flow meter at age 10 years. Two hundred six VLBW and 79 controls had additional home monitoring. Abnormality was defined as observed/predicted ratio <0.8 for PEF, FEV1, and FVC, and by criteria of Pelkonen for diurnal PEF variation. VLBW children were compared to controls, VLBW children with bronchopulmonary dysplasia (BPD) to those without, and those with respiratory conditions to those without. PEF and FEV1 showed high reproducibility (intraclass correlations, ICC 0.75–0.83). Controls and VLBW children with and without BPD differed significantly on all measures. Baseline test results did not differ across birth years, but PEF variation was less after surfactant availability (P = 0.04). Observed over predicted FEV1 was the most sensitive in detecting differences between groups (P < 0.001), with mean (s.d.) 0.97 (0.12) for controls, 0.88 (0.14) for VLBW children without BPD, and 0.78 (0.13) for those with BPD. Odds ratios for abnormality were especially high with respiratory medication use during the first 5 years of life, 4.4 (95% CI: 2.0–9.8) for FEV1 and 5.1 (95% CI: 2.0–13.2) for diurnal PEF variation. Our results show that respiratory abnormalities persist to at least age 10 years for VLBW children born in the surfactant era. Pediatr Pulmonol. 2007; 42:819–828. © 2007 Wiley‐Liss, Inc.