bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simultaneous chiral separation and determination of ephedrine alkaloids by MEKC‐ESI‐MS using polymeric surfactant I: Method development
Authors: Hou Jingguo , Zheng Jie , Rizvi Syed A. A. , Shamsi Shahab A. 
Published: April 2007

AbstractIn this work, simultaneous separation of eight stereoisomers of ephedrine and related compounds ((±)‐ephedrine, (±)‐pseudoephedrine, (±)‐norephedrine and (±)‐N‐methylephedrine) was accomplished using a polymeric chiral surfactant, i.e. polysodium N‐undecenoxycarbonyl‐L‐leucinate (poly‐L‐SUCL) by chiral (C)MEKC‐ESI‐MS. The conditions of CMEKC were first investigated. The baseline separation of all eight stereoisomers of ephedrine and related compounds was achieved under optimum CMEKC conditions (35 mM poly‐L‐SUCL, 15 mM NH4OAc, pH 6.0, 30% v/v ACN, 30 kV and 20°C) in less than 30 min. Next, a central composite design for response surface modeling has been described to evaluate the electrospray chamber parameters and the sheath liquid conditions. Optimum mass abundance of stereoisomers of ephedrine and related compounds was observed using the spray chamber parameters, namely 250°C drying gas temperature and 8 L/min drying gas flow rate at a nebulizer pressure of 4 psi. Furthermore, the experimental design indicates that the optimum mass abundance of the stereoisomers of ephedrine and related compounds can be obtained using a sheath liquid containing 80:20 v/v methanol‐water, 5 mM NH4OAc at pH 8.5 delivered at 5 µL/min. Finally, compared to MEKC‐UV, the use of poly‐L‐SUCL in MEKC‐MS provided significantly higher sensitivity for stereoisomers of ephedrine and related compounds.
The protective effect of N‐acetylcysteine against cyclosporine A‐induced hepatotoxicity in rats
Authors: Kaya Hasan , Koc Ahmet , Sogut Sadik , Duru Mehmet , Yilmaz H. Ramazan , Uz Efkan , Durgut Ramazan 
Published: April 2007

AbstractThe immunosuppressive agent cyclosporine A (CsA) has been reported to exert measurable hepatotoxic effects. One of the causes leading to hepatotoxicity is thought to be reactive oxygen radical formation. The aim of this study was to investigate the effects of N‐acetylcysteine (NAC) treatment on CsA‐induced hepatic damage by both analysing superoxide dismutase (SOD), glutathione peroxidase (GSH‐Px), aspartate aminotransferase (AST) and alanine transaminase (ALT) activities with malondialdehyde (MDA) and nitric oxide (NO) levels, and using an histological approach. CsA administration produced a decrease in hepatic SOD activity, and co‐administration of NAC with CsA resulted in an increase in SOD activity. MDA and NO levels increased in the CsA group and NAC treatment prevented those increases. A significant elevation in serum AST and ALT activities was observed in the CsA group, and when NAC and CsA were co‐administered, the activities of AST and ALT were close to the control levels. CsA treatment caused evident morphological alterations. Control rats showed no abnormality in the cytoarchitecture of the hepatic parenchyma. The co‐administration of NAC with CsA showed no signs of alteration and the morphological pattern was almost similar to the control group. In conclusion, CsA induced liver injury and NAC treatment prevented the toxic side effects induced by CsA administration through the antioxidant and radical scavenging effects of NAC. Copyright © 2007 John Wiley & Sons, Ltd.
Mitochondria a key role in microcystin‐LR kidney intoxication
Authors: La‐Salete R. , Oliveira M. M. , Palmeira C. A. , Almeida J. , Peixoto F. P. 
Published: April 2007

AbstractMicrocystins (MCs) are a group of closely related cyclic heptapeptides produced by a variety of common cyanobacteria. These toxins have been implicated in both human and livestock mortality. Microcystin‐LR could affect renal physiology by altering vascular, glomerular and urinary parameters, indicating that MC‐LR could act directly on the kidney. The aim of the current work was to examine the effect of MC‐LR on mitochondrial oxidative phosphorylation of rat kidney isolated mitochondria.Furthermore, microcystin‐LR decreased both state 3 and carbonylcyanide p‐trifluoromethoxyphenylhydrazone (FCCP)‐uncoupled respiration. The transmembrane potential was strongly depressed by MC‐LR in a concentration dependent manner, pointing to an uncoupling effect; however, microcystin‐LR did not increase the permeability of the inner mitochondria membrane to protons. Therefore, the transmembrane decrease was a consequence of a strong inhibitory effect on redox complexes. The addition of uncoupling concentrations of MC‐LR to Ca2+‐loaded mitochondria treated with ruthenium red resulted in mitochondrial permeability transition pore (MPTP) opening, as evidenced by mitochondrial swelling in isosmotic sucrose medium. Mitochondrial swelling in the presence of Ca2+ was prevented by cyclosporin A and was drastically inhibited by catalase and dithiothreitol, indicating the participation of mitochondrial generated reactive oxygen species in this process. From this study it can be concluded that the bioenergetic lesion promoted by microcystin‐LR seems to be sufficient to explain renal injury. Copyright © 2007 John Wiley & Sons, Ltd.
A superlinear lower bound for the size of a critical set in a latin square
Authors: Cavenagh Nicholas J. 
Published: April 2007

AbstractA critical set is a partial latin square that has a unique completion to a latin square, and is minimal with respect to this property. Let scs(n) denote the smallest possible size of a critical set in a latin square of order n. We show that for all n, $scs(n)\geq n\lfloor (\log{n})^{1/3}/2\rfloor$. Thus scs(n) is superlinear with respect to n. We also show that scs(n) ≥ 2n−32 and if n ≥ 25, ${\rm scs}(n)\geq \lceil (3n-7)/2 \rceil$. © 2007 Wiley Periodicals, Inc. J Combin Designs 15: 269–282, 2007
The effect of solids on the electrochemical treatment of olive mill effluents
Authors: Kotta Efi , Kalogerakis Nicolas , Mantzavinos Dionissios 
Published: April 2007

AbstractThe electrochemical oxidation of an olive mill effluent over Ti–Pt anodes was studied. The effluent had an average total chemical oxygen demand (COD) value of 234 g L−1, soluble COD of 61 g L−1, soluble phenolic content 3.4 g L−1, total solids of 80 g L−1 and pH = 5.1. Experiments were conducted in a 10 L vessel with the effluent recirculating at 1 L s−1. The applied current was varied between 5 and 20 A, the salinity between 1 and 4% NaCl, and experiments were performed with the effluent diluted with water to achieve the desired initial concentration. Emphasis was given to the effect of the presence of solids as well as of varying operating conditions on process performance as assessed in terms of COD, color and phenols removal. In general, degradation of phenols occurred relatively fast with conversion increasing with increasing applied current and decreasing initial organic loading and this was accompanied by low COD removal levels and moderate decolorization. The presence of solids had practically no effect on phenols removal, which, in most cases, was complete in less than about 180 min of reaction. However, oxidation in the presence of solids resulted in a substantial solid fraction being dissolved and this consequently increased sample color and the soluble COD content. The solid content typically found in olive mill effluents may partially impede its treatment by electrochemical oxidation, thus requiring more severe operating conditions and greater energy consumption. Copyright © 2007 Society of Chemical Industry
Manganese targets m‐aconitase and activates iron regulatory protein 2 in AF5 GABAergic cells
Authors: Crooks Daniel R. , Ghosh Manik C. , Braun‐Sommargren Michelle , Rouault Tracey A. , Smith Donald R. 
Published: April 2007

AbstractStudies suggest that disturbances of amino acid metabolism and cellular iron regulation are important mechanisms underlying manganese (Mn) neurotoxicity, although the targets underlying these disturbances are poorly defined. Using the AF5 neural‐derived cell line, which displays GABAergic properties, we showed that Mn significantly increased glutamate release to 174%–214% of that of the control and that the effects of Mn exposure on the metabolism of glutamate, glutamine, alanine, and GABA resembled the effects of fluorocitrate, an inhibitor of aconitase, but not the effects of other toxicants including paraquat, rotenone, or 3‐nitropropionic acid. Consistent with this, Mn inhibited aconitase activity in AF5 cells, resulting in a 90% increase in intracellular citrate; an in vitro assay revealed that m‐aconitase was significantly more sensitive to inhibition by Mn than was c‐aconitase. RNA mobility shift assay and Western blot showed that Mn treatment caused c‐aconitase to be converted to iron regulatory protein 1 (IRP1) and increased the abundance of IRP2, leading to reduced H‐ferritin expression, increased transferrin receptor expression, and increased uptake of transferrin. To determine the relative contributions of IRP1 and IRP2 in mediating the effects of Mn on iron homeostasis, we exposed transgenic fibroblasts lacking either c‐aconitase/IRP1 or IRP2 to Mn. Manganese exposure minimally altered ferritin levels in cells possessing only c‐aconitase/IRP1, whereas cells possessing only IRP2 showed a robust decrease in ferritin, indicating a dominant role of IRP2 in Mn‐induced alteration of iron homeostasis. Together, these results demonstrate that m‐aconitase is an important target of Mn and thatMn‐induced alteration of iron homeostasis is mediated predominantly through IRP2. © 2007 Wiley‐Liss, Inc.
Clinical features of patellar tendinopathy and their implications for rehabilitation
Authors: Crossley Kay M. , Thancanamootoo Kaviraj , Metcalf Ben R. , Cook Jill L. , Purdam Craig R. , Warden Stuart J. 
Published: April 2007

AbstractThis study investigated the clinical features of patellar tendinopathy (PT), with focus on individuals with unilateral and bilateral PT. A cross‐sectional study design was employed to compare individuals with unilateral (n = 14) or bilateral (n = 13) PT and those without PT (control, n = 31). Features assessed included thigh strength (normalized peak knee extensor torque) and flexibility (sit‐and‐reach and active knee extension), calf endurance (heel‐rise test), ankle flexibility (dorsiflexion), alignment measures (arch height and leg length difference), and functional measures (hop for distance and 6 m hop test). Groups were matched for age and height; however, unilateral and bilateral PT had greater mass with a higher body mass index (BMI) than control. Also, bilateral PT performed more sport hours per week than both unilateral PT and control. Unilateral PT had less thigh strength than control and bilateral PT, whereas bilateral PT had more thigh flexibility than control and unilateral PT. Both unilateral and bilateral PT had altered alignment measures compared to control. Features that predicted symptoms in PT were lower thigh flexibility and strength, whereas those that predicted function were higher thigh strength and lower ankle flexibility. These findings indicate that unilateral and bilateral PT represent distinct entities, and that thigh strength appears particularly important in PT as it predicted both symptoms and function in PT. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1164–1175, 2007
New protein PCiP from edible golden oyster mushroom (Pleurotus citrinopileatus) activating murine macrophages and splenocytes
Authors: Sheu Fuu , Chien Po‐Jung , Wang His‐Kai , Chang Hui‐Hsin , Shyu Yuan‐Tay 
Published: April 2007

AbstractA new immunomodulatory protein (PCiP) was purified from an edible golden oyster mushroom (Pleurotus citrinopileatus) by extraction with 5% (v/v) cold acetic acid in the presence of 0.1% (v/v) 2‐mercaptoethanol, followed by ammonium sulfate fractionation, DE‐52 and MonoQ anion‐exchange chromatography. Electrophoresis assays demonstrated that the molecular mass of PCiP was approximately 15.0 kDa and its pI was around 5.2. PCiP is a simple protein without carbohydrate, and cannot agglutinate mouse red blood cells, suggesting PCiP is not a lectin. In addition, PCiP (5–20 µg mL−1) alone activated murine splenocytes, and markedly increased their proliferation and gamma‐interferon (IFN‐γ secretion, but suppressed MTT metabolization, while murine splenocytes were simultaneously stimulated by the mitogen concanavalin A (ConA). Furthermore, PCiP (5–20 µg mL−1) directly activated murine macrophages and increased the production of both the nitric oxide (NO) and tumor necrosis factor‐alpha (TNF‐α by RAW 264.7 macrophages. These findings suggest that PCiP could strengthen both the innate and adaptive responses of its host. Copyright © 2007 Society of Chemical Industry
Profiling glucosinolates in vegetative and reproductive tissues of four Brassica species of the U‐triangle for their biofumigation potential
Authors: Bellostas Natalia , Sørensen Jens C , Sørensen Hilmer 
Published: April 2007

AbstractGlucosinolates are amino acid derived allelochemicals present in all plants of the order Capparales. These compounds are degraded by myrosinase isoenzymes, releasing a series of biologically active products defined by the parent glucosinolate and the reaction conditions. Species within the Brassicaceae are found to differ in their glucosinolate profile and glucosinolate concentrations. Different tissues within a single plant also show such variations, which are further influenced by the growth stage and environmental conditions. In the experiments described in this paper, four Brassica species of the U‐triangle (B. carinata, B. nigra, B. juncea and B. rapa) were compared with respect to their glucosinolate profiles in roots, stems, leaves and reproductive organs at different developmental stages. The glucosinolate profile of corresponding ripe seeds was also determined. Prop‐2‐enylglucosinolate was identified as the major glucosinolate in the three mustards, where it represented over 90% of the total glucosinolate concentration of ripe seeds and over 50% of green tissues. The relative concentration of this glucosinolate increased in all tissues during plant growth. Brassica rapa showed a different glucosinolate profile than the three mustards, with higher concentrations of but‐3‐enylglucosinolate, 2‐hydroxybut‐3‐enylglucosinolate and 2‐hydroxypent‐4‐enylglucosinolate. The concentration of indol‐3‐ylmethylglucosinolates was also higher in B. rapa than in the mustard plants, with 4‐hydroxyglucobrassicin representing 30% of the total glucosinolate concentration in ripe seeds. The total glucosinolate concentration of the species studied varied with growth stage and the mustards achieved a maximum towards the end of the period monitored. Glucosinolate concentration decreased in roots and leaves but increased in reproductive tissues. The determined glucosinolate profiles are an initial step in assessing the biofumigation potential of these species of the Brassicaceae family. Copyright © 2007 Society of Chemical Industry
Functionalized Multi‐Walled Carbon Nanotubes Prepared by In Situ Polycondensation of Polyurethane
Authors: Chen Xianhong , Chen Xiaojin , Lin Ming , Zhong Wenbin , Chen Xiaohua , Chen Zhenhua 
Published: April 2007

AbstractTreating MWCNTs with an acidic solution (concentrated H2SO4/HNO3; 3:1) and subsequently with succinic acid peroxide leads to MWCNTs functionalized with carboxyl groups on their sidewalls (or surfaces). These MWCNT‐COOH were converted to MWCNT‐COCl and further to MWCNT‐NH2. The PU was covalently coated onto the sidewalls (or surfaces) of the MWCNT by in situ polymerization of TDI under ultrasound in the presence of MWCNT‐NH2. The results show that PU is chemically tethered to the MWCNT sidewalls (or surfaces) via the ∼HNCONH∼ linkage, with a thickness in the range of approximately 2 to 5 nm, and the amount of grafted PU is about 34 wt.‐%.magnified image
Formation and Photoresponsive Properties of Giant Microvesicles Assembled from Azobenzene‐Containing Amphiphilic Diblock Copolymers
Authors: Su Wei , Han Kuo , Luo Yanhua , Wang Zhong , Li Yinmei , Zhang Qijin 
Published: April 2007

AbstractDiblock copolymers composed of poly(acrylic acid) and poly{6‐[4‐(4‐methylphenylazo)phenoxy]hexyl acrylate} (PAA‐block‐PAzoM) were synthesized by RAFT polymerization. In a mixture of H2O and THF, PAA‐block‐PAzoM self‐assembled into giant spherical microvesicles, which were dispersed in the mixture. Using UV‐vis spectroscopy and optical microscopy, it is demonstrated that the spherical shape of the vesicles results from a framework composed of the azobenzene H‐aggregate skeleton. A plausible structural model of the microvesicles is proposed, and a discussion on the formation of H‐aggregates and the photoresponsive properties is presented.magnified image
Synthesis and Characterization of Poly[oxy(ω,ω,ω‐trifluoroalkylsulfonylmethyl)ethylene]s: Effect of Terminal CF3 and CH3 Moieties on the Wettability of the Comb‐Like Polymers
Authors: Kim Byoung Gak , Sohn Eun‐Ho , Lee Jong‐Chan 
Published: April 2007

AbstractTwo CF3‐terminated polymers were synthesized by polymer analogous reactions in order to study the effect of the terminal CF3 groups on their surface properties. ESCA and NEXAFS showed that they contain highly ordered side chains oriented perpendicularly to the polymer surface. The CF3‐terminated polymers showed enhanced wettability by polar solvents as compared to the corresponding CH3‐terminated polymers, while the wettability by non‐polar dodecane showed the opposite trend. This was attributed to specific interactions between the oriented surface dipoles of the CF3‐terminated surfaces and the polar solvents. Thus, terminal CF3 groups in a polymer can increase its surface polarity.magnified image
Ultrahigh‐Molecular‐Weight Polyethylene by Using a Titanium Calix[4]arene Complex with High Thermal Stability under Polymerization Conditions
Authors: Frediani Marco , Sémeril David , Comucci Alessandro , Bettucci Lorenzo , Frediani Piero , Rosi Luca , Matt Dominique , Toupet Loïc , Kaminsky Walter 
Published: April 2007

AbstractThe new complex 25,27‐dipropyloxy‐26,28‐dioxocalix[4]arene titanium (IV) dichloride (1) was evaluated as an ethylene polymerization catalyst. Activation with methylalumoxane resulted in an active system producing ultrahigh‐molecular‐weight polyethylene. As expected for a Ziegler‐Natta catalyst, the polymerization reaction follows first‐order kinetics. The most striking feature of the catalytic system (1/MAO) is its remarkably high thermal stability. This peculiarity probably relies on the electronic stabilization of the metal center by the two coordinating propoxy groups.magnified image
Über nichtlineare Eigenwertaufgaben in konvexen Mengen
Authors: Miersemann Erich 
Published: April 2007

AbstractWe consider the bifurcation problem of a general class of variational inequalities at the first igenvalue of the associated linear problem. Essentially we use a generalization of LJUSTERNIK's emma, MIERSEMANN [13]. We apply our results to buckling problems for the thin elastic plate.
Nonlinear Elliptic Variational Inequalities
Authors: Bose Deb K. , Brill Heinz 
Published: April 2007

AbstractWe consider the problem of finding a solution to a class of nonlinear elliptic variational inequalities. These inequalities may be defined on bounded or unbounded domains Ω, and the nonlinearity can depend on gradient terms. Appropriate definitions of sub‐and supersolutions relative to the constraint sets are given. By using a mixture of maximal monotone operator theory and compactness arguments we prove the existence of a H2(Ω) solution lying between a given subsolution φ1 and a given supersolution φ2≧φ1, when Ω is bounded, and a H1(Ω) solution when Ω is unbounded.
On maximally unitarily mixed states on W*‐algebras
Authors: Alberti P. M. 
Published: April 2007

AbstractThe matter of discussion is the set of states on W*‐algebras. States are considered in relation to unitary mixing where the full group of unitary elements is used. Among all the states, one could talk about, we are mainly interested in studying those the degree of mixture of which is maximally. We give a general description of the set of maximally unitarily mixed states. For a finite W*‐algebra the set of states in question is identified as the set of unitarily invariant states and for each state there is precisely one maximally mixed state comparable with it in the sense of unitary mixture. The latter fact fails to be true in the general case of an infinite W*‐algebra. In this case the problem is more complicated. For a properly infinite W*‐algebra we introduce an interesting symmetric ideal, the c‐ideal. We prove that a state on a properly infinite W*‐algebra is maximally mixed if and only if its kernel contains the c‐ideal, i. e. maximally mixed states may be identified with the set of states on the quotient algebra generated by the c‐ideal. For a general infinite W*‐algebra the solution of the problem can be represented as a combination of both above mentioned cases. The point of view we adopted in handling the mixture relation has its origin in UHLMANN'S work.
Safety and tolerability of growth hormone therapy in multiple system atrophy: A double‐blind, placebo‐controlled study
Authors: Holmberg Björn , Johansson Jan‐Ove , Poewe Werner , Wenning Gregor , Quinn Niall P. , Mathias Chris , Tolosa Eduardo , Cardozo Adriana , Dizdar Nil , Rascol Olivier , Slaoui Tarik ,   Growth‐Hormone MSA Study Group,   European MSA Study Group (EMSA‐SG)
Published: April 2007

AbstractThe objective of this study was to investigate tolerability and possible neurotrophic effects of growth hormone (GH) in treatment of multiple system atrophy (MSA). In this double‐blind pilot study, MSA patients were randomized to recombinant human growth hormone (r‐hGH, n = 22), 1 mg every second day (6 months) followed by alternating daily injections of 1 mg and 0.5 mg (6 months), or matched placebo (n = 21). Safety analysis demonstrated no obvious between‐group differences. In both groups, there was progressive worsening of Unified Parkinson's Disease Rating Scale total score, which tended to be less in r‐hGH‐treated patients (12.9% at 6 months, 25.3% at 12 months) than in placebo (17.0% and 35.7%). Similarly, there was a trend to less worsening in Unified MSA Rating Scale total score with r‐hGH (13.2% and 21.2%) than with placebo (21.1% and 36.5%). Cardiovascular reflex autonomic testing also tended to show less deterioration with r‐hGH than with placebo at 12 months. However, 95% CI did not indicate treatment differences for any efficacy measures. In conclusion, r‐hGH administration in MSA patients for up to 1 year appears safe and might influence disease symptoms, signs and, possibly, progression. The results support further studies utilizing higher doses in more patients. © 2007 Movement Disorder Society