bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flabelliformides A and B, Two Novel Indole Alkaloids from Ervatamia flabelliformis
Authors: Liang Shuang , Chen Hai‐Sheng , Shen Yun‐Heng , Jin Li , Zhang Wei‐Dong 
Published: August 2007

AbstractFlabelliformides A (1) and B (2), containing a novel C20 indole core, have been isolated from the stems of Ervatamia flabelliformis. The structures of 1 and 2 were elucidated on the basis of spectral analysis and X‐ray crystallography.
N‐Heterocyclic Carbene–Palladium Complexes as Efficient Catalysts for the Oxidative Carbonylation of Amines to Ureas
Authors: Zheng Shuzhan , Peng Xingao , Liu Jianming , Sun Wei , Xia Chungu 
Published: August 2007

AbstractA highly efficient oxidative carbonylation reaction of amines to ureas was developed making use of carbene–palladium complexes in the absence of any promoter. Both aliphatic amines and aromatic amines were transformed in good to excellent yields to the expected ureas.
Chemical Constituents from Craibiodendron yunnanense
Authors: Yang Sheng‐Xiang , Gao Jin‐Ming , Qin Jian‐Chun , Zhou Lin , Chiu Ming‐Hua , Wang Lei 
Published: August 2007

AbstractA new triterpene, (3β,12β)‐taraxast‐20(30)‐ene‐3,12‐diol (=(3β,12β,18α,19α)‐urs‐20(30)‐ene‐3,12‐diol; 1), together with the known compounds ursolic acid, α‐amyrin, β‐amyrin, (2α,3β)‐2,3‐dihydroxyursa‐5,12‐dien‐28‐oic acid, (2α,3β)‐2,3,23‐trihydroxyurs‐12‐en‐28‐oic acid, (2S,3S,4R,8Z)‐1‐O‐(β‐D‐glucopyranosyl)‐2‐{[(2R)‐2‐hydroxydocosanoyl]amino}octadec‐8‐ene‐1,3,4‐triol, and (2S,3S,4R,8Z)‐1‐O‐(β‐D‐glucopyranosyl)‐2‐[(palmitoyl)amino]octadec‐8‐ene‐1,3,4‐triol, and quercetin 3‐(β‐D‐glucopyranoside) were isolated from the leaves of Craibiodendron yunnanense. Their structures were established on the basis of spectral evidence. The last four compounds were identified for the first time in this plant.
Synthesis, Configuration, and Antimicrobial Properties of Novel Substituted and Cyclized ‘2′,3″‐Thiazachalcones’
Authors: Usta Asu , Yaşar Ahmet , Yılmaz Nagihan , Güleç Canan , Yaylı Nuran , Karaoğlu Şengül Alpay , Yaylı Nurettin 
Published: August 2007

AbstractNine new thiazachalcone‐based drugs, compounds 1–9, were prepared and fully characterized. The configurations of the photochemical‐dimerization products 7–9 were rationalized by semi‐empirical calculations. Both the experimental data and the theoretical calculations showed that the δ‐truxinic acid type dimer is the most stable isomer of all. All compounds were tested for their antibacterial and antifungal activities. The N‐alkylated congeners 4–6 showed strong antimicrobial activities against various bacteria and a yeast‐like fungus. The MIC and MBC values were as low as 0.1 μg/ml. All the compounds were active against the Gram‐positive bacterium Staphylococcus aureus.
Isolation and Structure Elucidation of Nortriterpenoids from Schisandra rubriflora
Authors: Xiao Wei‐Lie , Pu Jian‐Xin , Wang Rui‐Rui , Yang Liu‐Meng , Li Xiao‐Li , Li Sheng‐Hong , Li Rong‐Tao , Huang Sheng‐Xiong , Zheng Yong‐Tang , Sun Han‐Dong 
Published: August 2007

AbstractSeven new highly oxygenated nortriterpenoids, rubriflorins D–J (1–7), were isolated from the leaves and stems of Schisandra rubriflora, and their structures were elucidated on the basis of extensive analysis of spectroscopic data. These new compounds feature the opening of ring A compared with related known nortriterpenoids isolated from the genus Schisandra and showed weak activity against HIV‐1.
Withanolide Compounds from the Flower of Datura metel L.
Authors: Yang Bingyou , Wang Qiuhong , Xia Yonggang , Feng Weisheng , Kuang Haixue 
Published: August 2007

AbstractThree new withanolide compounds named baimantuoluoline A (1), B (2), and C (3) and the two known withanolides withafastuosin E (4) and withametelin C (5) were isolated from the fraction exhibiting activity for psoriasis in the flower of Datura metel L. The three new structures were determined as (5α,6α,7α,12β,15β,22R)‐6,7‐epoxy‐5,12,15‐trihydroxy‐1‐oxowitha‐2,24‐dienolide (1), (5α,6β,15β,22R)‐ 5,6,15,21‐tetrahydroxy‐1‐oxowith‐24‐enolide (2), and (5α,6β,12β,22R)‐5,6,12,21‐tetrahydroxy‐27‐methoxy‐1‐oxowitha‐2,24‐dienolide (3) on the basis of extensive spectroscopic data (HR‐ESI‐MS, 1H‐ and 13C‐NMR, 1H,1H‐COSY, HSQC, HMBC, and NOESY) (withanolide=22‐hydroxyergostan‐26‐oic acid δ‐lactone).
Kinetics and Mechanism of the Reaction between an Arenediazonium Ion and Methyl Gallate (=Methyl 3,4,5‐Trihydroxybenzoate) in Aqueous Solution: Evidence for Diazo Ether Formation through an O‐Coupling Reaction
Authors: Losada‐Barreiro Sonia , Sánchez‐Paz Verónica , Bravo‐Díaz Carlos 
Published: August 2007

AbstractWe have investigated the kinetics and mechanism of the reaction between 3‐methylbenzenediazonium ions (3MBD) and methyl gallate (=methyl 3,4,5‐trihydroxybenzoate; MG), in aqueous buffer solution by employing spectrophotometric (UV/VIS) and electrochemical (linear‐sweep voltammetry, LSV) techniques and computational methods. Because the absorption band of MG overlaps that of 3MBD, the reaction was monitored spectrophotometrically by measuring the changes in absorbance with time due to product formation, and biphasic kinetic profiles, indicative of accumulation of an intermediate in the course of the reaction, were obtained. The formation of an intermediate was confirmed by LSV. The observed rate constants kobs for 3MBD disappearance were obtained by fitting the decrease in the peak current of the first reduction peak of 3MBD with time to the integrated first‐order equation. The variation of kobs with [MG] was determined at different pH values and follows a saturation kinetic pattern. Alternatively, at a fixed [MG], kobs values show an inverse dependence on [H+], suggesting that the reactive species is the anion and not the neutral form of MG. To discern which of the three OH groups of MG is the first one undergoing deprotonation, the geometries of the resulting anions were optimized by using B3LYP hybrid density functional theory (DFT) and a 6‐31G(++d,p) basis set. The deprotonation energies suggest that the OH group at the 4‐position is first deprotonated. The kinetic results can be accommodated, therefore, by assuming two competitive mechanisms, the spontaneous DN+AN decomposition involving 3MBD, and a mechanism involving an electrophilic attack at the O‐atom at C(4) in a pre‐equilibrium step, leading to the formation of a transient diazo ether of the type ArNNOR which further decomposes. All attempts to isolate and characterize the diazo ether failed.
Further New Cembranoid Diterpenes from the Hainan Soft Coral Sarcophyton latum
Authors: Yan Xiao‐Hong , Li Zhen‐Yu , Guo Yue‐Wei 
Published: August 2007

AbstractFour new cembranoid diterpenes, sarcophytonolides I–L (1–4), were isolated from the Hainan soft coral Sarcophyton latum. Their structures were established by detailed analysis of 1D and 2D NMR spectra and by comparison with related model compounds.
Efficient Synthesis of Oxazolidin‐2‐one via (Chitosan‐Schiff Base)cobalt(II)‐Catalyzed Oxidative Carbonylation of 2‐Aminoalkan‐1‐ols
Authors: Liu Jianming , Sun Wei , Zheng Shuzhan , Xia Chungu 
Published: August 2007

AbstractThe (chitosan‐Schiff base)cobalt(II) complex was found to be an efficient catalyst for the oxidative carbonylation (CO/O2) of 2‐aminoalkan‐1‐ols 1 to give oxazolidin‐2‐ones 2, in the presence of NaI. The effects of promoters, temperature, solvents, and other reaction conditions were investigated in this study.
Spatial sampling requirements for monitoring upper‐air climate change with radiosondes
Authors: McCarthy Mark P. 
Published: August 2007

AbstractThe global climate observing system upper air network (GUAN) was established to provide a network of high quality radiosonde stations with sufficient historical data records, and a commitment to future observing, in support of the needs of the climate research community. An assessment of the spatial sampling requirements for such a network in order to monitor large‐scale climate changes has been conducted.The GUAN provides adequate coverage for monitoring global, tropical and hemispheric mean climate. Priority stations within the GUAN have been identified based upon their unique contribution to the network. Further sampling improvements to the GUAN may be possible by utilizing radiosonde stations located in India, Africa and northern polar regions. To keep sampling‐related trend error below 0.05 K/decade in the troposphere, and 0.1 K/decade in the stratosphere, requires a radiosonde station to be located approximately every 30° longitude and 15° latitude north of 30°N. The inhomogeneous distribution of radiosonde stations in the tropics and southern hemisphere place a stronger requirement of 20° longitude and 10° latitude south of 30°N. The radiosonde network is inadequate for monitoring humidity except in the northern mid‐latitudes. © Crown Copyright 2007. Reproduced with the permission of the Controller of HMSO. Published by John Wiley & Sons, Ltd
1H and 23Na MRI studies of Atlantic salmon (Salmo salar) and Atlantic cod (Gadus morhua) fillet pieces salted in different brine concentrations
Authors: Veliyulin Emil , Aursand Ida G 
Published: August 2007

AbstractBACKGROUND: Applicability of magnetic resonance imaging (MRI) to quantitative analysis of sodium in salted fish products is usually impaired by the partial 23Na MRI ‘invisibility’ phenomena as well as high investment costs of the MRI equipment.RESULTS: Salmon and cod fillet pieces, unsalted and brine salted (50, 100, 150, 200 and 250 g kg−1 NaCl) for 48 h, were studied using 1H and 23Na MRI. Based on MRI results, T1 and T2 relaxation times were calculated for 1H and the T2 time for 23Na nuclei. In addition, water diffusion images for all fillet samples and reference brine solutions were obtained. Variation of the nuclear magnetic resonance relaxation times and water diffusion constants with brine concentration is discussed in terms of the muscle structural changes. Sodium MRI visibility factors for the MRI method used were determined for all fish samples.CONCLUSION: Observed changes in proton and sodium NMR relaxation times with the salt content reflect complex counteraction of several factors related to the muscle structural changes. Sodium MRI visibility factors appear to be dependent on a number of experimental factors in a complex matter, making quantitative sodium analysis by the MRI technique used non‐trivial. Copyright © 2007 Society of Chemical Industry
Processing and Characterization of Waxy Maize Starch Films Plasticized by Sorbitol and Reinforced with Starch Nanocrystals
Authors: Viguié Jérémie , Molina‐Boisseau Sonia , Dufresne Alain 
Published: August 2007

AbstractNanocomposites films have been processed from a filler and a matrix having the same nature, i.e. waxy maize starch. The filler consists of nanoplatelet‐like starch particles obtained as an aqueous suspension by acid hydrolysis of starch granules and the matrix was prepared by plasticization and disruption of starch granules with water and sorbitol. Nanocomposite films were obtained by casting and evaporating the mixture of the aqueous suspension of starch nanocrystals with the gelatinized starch. The resulting films were conditioned before testing and the effect of accelerated ageing in moist atmosphere was investigated. The thermal properties of the nanocomposite films were determined from DSC measurements and the mechanical characterization was performed in both the linear and nonlinear range.magnified image
Micellization of Poly(2‐oxazoline)‐Based Quasi‐Diblock Copolymers on Surfaces
Authors: Fustin Charles‐André , Lefèvre Nathalie , Hoogenboom Richard , Schubert Ulrich S. , Gohy Jean‐François 
Published: August 2007

AbstractThe micellization on surfaces of two series of quasi‐diblock copoly(2‐oxazoline)s consisting of 2‐phenyl‐2‐oxazoline (PhOx) segments linked to either 2‐methyl‐2‐oxazoline (MeOx) or 2‐ethyl‐2‐oxazoline (EtOx) segments is investigated in detail. Those micelles are not pre‐existing in the initial ethanol solution but are formed during the spin‐coating process by the evaporation of the solvent inducing the precipitation of the less soluble PhOx segments. The morphology and size of the surface micelles vary according to the fraction of PhOx in the copolymers. Moreover, it is demonstrated that the chemical nature of the more soluble MeOx or EtOx segments also has an influence on the morphology of the resulting surface micelles.magnified image
A Mechanistic and Characteristic Investigation of Electrooxidation of 2‐Amino‐3‐cyano‐4‐methylthiophene
Authors: Pak Faruk , Ekinci Duygu , Tümer Ferhan , Demir Ümit 
Published: August 2007

AbstractThe electrochemical oligomerization of 2‐amino‐3‐cyano‐4‐methylthiophene (ACMT) has been studied by cyclic voltammetry, potential controlled electrolysis and digital simulation. The product analysis after preparative electrolysis was carried out by UV‐vis‐NIR, 1H and 13C NMR and FT‐IR spectroscopic techniques. The kinetic data were estimated using the results of fitting the digitally simulated voltammograms to the experimentally obtained cyclic voltammograms. The oligomerization proceeds according to an ECE mechanism resulting in the formation of an oligomeric mixture containing dimer and tetramer. UV‐vis‐NIR and fluorescence measurements indicated that the isolated dimer and tetramer showed higher conjugation than the monomer unit and the conjugation increased with an increase in the number of monomer units.magnified image
Piezoelectric Ink‐Jet Printing of Horseradish Peroxidase: Effect of Ink Viscosity Modifiers on Activity
Authors: Di Risio Sabina , Yan Ning 
Published: August 2007

AbstractIn this study a bioink containing the horseradish peroxidase (HRP) enzyme was formulated and jetted with a piezoelectric‐based ink‐jet deposition system. A number of polymers with different molecular weights, functional groups and electric charge were tested as viscosity modifiers. The impact of viscosity modifiers on HRP activity was systematically studied. It was found that viscosity modifiers typically used in commercial ink formulations significantly impaired HRP activity possibly due to limitations in diffusion. In contrast, carboxymethyl cellulose increased viscosity to the desired range for piezoelectric jetting without negatively affecting the HRP activity. Good jettability was obtained for the HRP bioink by adding a suitable surfactant, a viscosity modifier and a humectant.magnified image
Energy Transfer Between a Cationic‐Conjugated Poly(fluorene‐co‐phenylene) and Thiazole Orange for DNA Hybridization Detection Involving G‐Rich Sequences
Authors: Liu Bin , Bazan Guillermo C. 
Published: August 2007

AbstractEfficient energy transfer between a cationic poly(fluorene‐co‐phenylene) and thiazole orange mediated by a G‐rich oligonucleotide provided sensitized TO emission over 25 000‐fold more intense than that from free TO. Higher energy transfer efficiency to ssDNA/TO relative to dsDNA/TO leads to an improved sensitivity and selectivity in G‐rich DNA hybridization detection as compared to the direct use of TO as the signal reporter. The signal amplification provided by conjugated polymers is useful to amplify the response from other TO‐based detection protocols.magnified image
Reliability and validity of ICARS in focal cerebellar lesions
Authors: Schoch Beate , Regel Jens Peter , Frings Markus , Gerwig Marcus , Maschke Matthias , Neuhäuser Markus , Timmann Dagmar 
Published: August 2007

AbstractTo evaluate the therapies for cerebellar diseases appropriate neurological assessment methods to measure severity of ataxia are required. Reliability and validity of the semiquantitative International Cooperative Ataxia Rating Scale (ICARS) has recently been examined in patients with degenerative ataxias. We evaluated reliability (internal consistency), criterion‐related validity and internal construct validity of ICARS for the first time in patients with focal cerebellar lesions (68 patients with surgical lesions and 68 patients with ischemic lesions). For comparison 45 patients with degenerative cerebellar ataxia were included. We found an excellent Cronbach's α as a measurement for internal consistency which was independent from underlying disease. Criterion‐related validity was high. Total ICARS score mirrored clearly the immediate postsurgical worsening and the improvement during the first 3 months after focal surgical and ischemic lesions, whereas in chronic state of focal and degenerative cerebellar disorders ICARS score remained nearly unchanged. Principal component analysis in patients with focal lesions revealed five distinct and clinically meaningful factors which corresponded to the four ICARS subscores and reflected the laterality of kinetic functions. In degenerative disorders, however, the items for the subscore “kinetic function” loaded to more than one factor. Total ICARS score seems to be a useful and valid measurement to describe the time course of ataxia in patients with focal and degenerative disorders affecting primarily the cerebellum. Validity of subscores however is good in focal, but not in degenerative disorders. © 2007 Movement Disorder Society
Different cerebral cortical areas influence the effect of subthalamic nucleus stimulation on parkinsonian motor deficits and freezing of gait
Authors: Lyoo Chul Hyoung , Aalto Sargo , Rinne Juha O , Lee Ki Ook , Oh Seung Hun , Chang Jin Woo , Lee Myung Sik 
Published: August 2007

AbstractInconsistent response in freezing of gait (FOG) with levodopa treatment or STN DBS makes the pathogenesis difficult to understand. We studied brain areas associated with the expression of STN DBS effect on parkinsonian motor deficits and FOG. Ten Parkinson's disease patients with typical FOG were included. One month before STN DBS, we performed [18F]‐deoxyglucose PET scans and measured the UPDRS motor and modified FOG (mFOG) scores during levodopa off and on periods. At two months after STN DBS, same rating scores were measured. The percentage improvement of mFOG and UPDRS motor scores by STN DBS during levodopa off period was calculated. We searched for brain areas in which glucose metabolism correlated with the improvement of mFOG and UPDRS motor scores by DBS. During levodopa off period, STN DBS improved the UPDRS motor scores by 32.3% and the mFOG scores by 56.6%. There was no correlation between the improvements of both scores. The improvement of UPDRS motor score by DBS correlated with the metabolic activities of rostral supplementary motor area (Brodmann's area 8; BA8), anterior cingulate cortex (BA32), and prefrontal cortex (BA9). On the other hand, there was a positive correlation between the improvement of mFOG score by DBS and the metabolic activity of the parietal, occipital, and temporal sensory association cortices. In conclusion, dysfunction of different cerebral cortical areas limits the beneficial effects of DBS on parkinsonian motor deficits and FOG. © 2007 Movement Disorder Society
Cause of death in Wilson disease
Authors: Walshe John M. 
Published: August 2007

AbstractBefore 1948, all patients with Wilson disease died shortly after diagnosis. In 1948, BAL (dimercaprol) was introduced as a possible effective treatment, to be followed by penicillamine (1955), zinc salts (1961), trientine (1969), liver transplantation (1982), and tetrathiomolybdate (1984). Despite this wide range of therapeutic options, patients still die. This article examines the cause of death in 67 patients (33 men, 34 women) out of a series of 300 seen between 1948 and 2000. Patients were classified according to their presentation as neurological, 32 patients, hepatic 11, mixed hepatic/neurological 10, hemolytic, 6, and “sibling biopsy ” 8. Diagnostic failure was the principal cause of death but there were multiple other causes of which the principal was poor compliance and the development of malignant disease after 10 years of follow‐up. The development of new symptoms should alert the physician to the possibility of a new pathology. © 2007 Movement Disorder Society
Pure akinesia with gait freezing: A third clinical phenotype of progressive supranuclear palsy
Authors: Williams David R. , Holton Janice L. , Strand Kate , Revesz Tamas , Lees Andrew J. 
Published: August 2007

AbstractThe clinical syndrome of pure akinesia has most often been associated with progressive supranuclear palsy (PSP) and is characterized by difficulty initiating gait and “freezing” during walking, writing and speaking. Similar syndromes have been described under the rubrics of primary progressive freezing gait and primary gait ignition failure. We investigated the specificity of the clinical syndrome of pure akinesia with gait freezing (PAGF) for PSP‐tau pathology. Among 749 patients archived at the QSBB, only 7 fulfilled proposed diagnostic criteria of: gradual onset of freezing of gait or speech; absent limb rigidity and tremor; no sustained response to levodopa; and no dementia or ophthalmoplegia in the first 5 years of disease. In these cases detailed pathological examination was performed. PSP was the pathological diagnosis in six patients, and Parkinson's disease (PD) in the seventh. As defined, this syndrome had a positive predictive value of 86% for PSP‐tau pathology. In the cases with PSP there were no additional features of coexistent vascular or PD and the median PSP‐tau score was 3, reflecting relative mild tau load. The clinical syndrome of PAGF appears to have a high specificity for PSP‐tau pathology. This relatively uncommon presentation of PSP‐tau pathology has less severe tau accumulation than in the more common, “classic” PSP clinical phenotype: Richardson's disease. © 2007 Movement Disorder Society
CD44‐positive colorectal adenoma cells express the potential stem cell markers musashi antigen (msi1) and ephrin B2 receptor (EphB2)
Authors: Schulenburg A , Cech P , Herbacek I , Marian B , Wrba F , Valent P , Ulrich‐Pur H 
Published: August 2007

AbstractThe majority of colorectal adenomas contain a mutation in the APC gene activating the wnt pathway. As wnt signalling preserves stem cell functions, it would be expected that stem cells would be enriched in adenomas. We have shown expression of the wnt target gene CD44, which may characterize the expanded stem cell compartment, in colorectal tumours. To investigate this possibility, we performed an immunohistological survey of CD44 expression in relation to the proliferation marker Ki67 and apoptosis in colorectal tumour tissue, and have isolated a CD44‐positive subpopulation of the human colorectal adenoma cell line LT97 for cell biological analysis. In tissues, CD44 expression was not related to Ki67, but was associated with lower apoptosis in the CD44‐positive areas. CD44‐positive and ‐negative populations isolated from LT97 cultures were identical in their Ki‐ras and p53 status but differed in their growth and survival characteristics. While CD44‐positive cells attached and grew to reconstitute the original culture, the CD44‐negative cells rapidly underwent apoptosis and were unable to resume growth. In comparison to unsorted growing LT97 cells, the CD44‐positive cells had shifted ß‐catenin into the nucleus and expressed ß‐catenin target genes, such as ephrin B receptor (ephB2) and musashi antigen (msi1). By contrast, CD44‐negative cultures contained no cells with nuclear β‐catenin. In summary, the CD44‐positive cells accumulating in colorectal tumours have increased survival capacity both in vivo and in vitro. They also express markers typical of colorectal progenitor cells, msi1 and ephB2, in the premalignant progenitor population. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.