bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study on the structure of nylon 6 films iodinated before forming. II. Investigation of the crystallization behavior through thermal analysis
Authors: Jeong Won Young , Kang Young Ah , Lee Yang Hun 
Published: August 2004

AbstractTwo kinds of amorphous nylon 6 films iodinated before forming from the powders iodinated with 0.2N and 1.0N I2/KI aqueous solutions were prepared by a melt‐press, and isothermally treated at 20 to 80°C for 1 day to 20 days. Thermal analyses were performed to investigate mainly the crystallization behavior on the treatment. The DSC thermograms for the treated films exhibit three temperature‐groups of endothermic peaks at 60 ∼ 70°C, 105 ∼ 120°C, and higher than 150°C, which may be associated with the melting of the complex crystal, the relaxed γ‐crystal, and the relaxed α‐crystal, respectively. The film containing less I2/KI and treated at the higher temperature exhibits the peaks associated with the more stable type of crystal. The peak temperature generally increases with the treating temperature and time. On the occasion of there being two peaks associated with the γ‐crystal and the α‐crystals, ΔH for the α‐crystal increases while that for the γ‐crystal decreases with increasing the treating time. The TG curves indicate two temperature‐zones of weight loss by the volatilization of I2 from I5− and the decompositions of I3− and nylon 6. With increasing treating temperature, the % weight loss by the volatilization of I2 decreases, and consequently the temperature of the weight loss by the decomposition of nylon 6 increases. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1062–1069, 2004
Endovascular repair of carotid artery aneurysm with Jostent covered stent: Initial experience and one‐year result
Authors: Chan Albert W. , Yadav Jay S. , Krieger Derk , Abou‐Chebl Alex 
Published: August 2004

AbstractTreatment for symptomatic extracranial carotid artery aneurysm is evolving and we describe two cases of successful endovascular treatment of distal internal carotid aneurysm using Jostent, a balloon‐expandable coronary polytetrafluoroethylene‐covered stent. Both patients remained symptom‐free at 1 year after the procedure and patency of the stents was maintained. We conclude that endovascular treatment of carotid artery aneurysm with Jostent is feasible and safe and may be more preferable than conventional strategies. Catheter Cardiovasc Interv 2004;63:15–20. © 2004 Wiley‐Liss, Inc.
Parental views of surveillance for early speech and language difficulties
Authors: Glogowska Margaret , Campbell Rona 
Published: August 2004

Objective: To investigate parents' experiences of surveillance for early talking difficulties. Design: Qualitative study nested within a randomised controlled trial. Setting: Interviews with the parents of 20 children identified as having early difficulties. Results: Most parents were in favour of surveillance of children's language. Parents do not totally welcome surveillance, however, as it also potentially medicalises their children's early lives. The study also revealed that many of the parents felt stigmatised by their children's difficulties. Conclusions: Listening to parents' accounts can increase professionals' understanding of their responses to monitoring of their child's development and referral to specialist services.
Evaluation of two pairs of chiral stationary phases: Effects from the length of the achiral spacers
Authors: Thunberg Linda , Allenmark Stig , Friberg Annika , Ek Fredrik , Frejd Torbjörn 
Published: August 2004

AbstractTwo pairs of chiral stationary phases (CSPs) with different C2‐symmetric central parts were prepared and evaluated by chromatography of a series of structurally different racemates. Within each pair, the selectors on which the CSPs are based had different lengths of their achiral spacers. The CSPs based on selectors with short spacers showed higher enantioselectivity than the phases incorporating long spacers. On one pair of the phases, a study of the influence from different retention modifiers was performed for a series of benzodiazepinones. This demonstrated the importance of the polymer structure formed from the selectors with different spacer lengths for the enantiodiscriminating ability of the CSPs. Chirality 16:614–624, 2004. © 2004 Wiley‐Liss, Inc.
Role of hydrochloric acid in the treatment of central venous catheter infections in children with cancer
Authors: Barbaric Draga , Curtin Julie , Pearson Lyra , Shaw Peter J. 
Published: August 2004

AbstractBACKGROUNDThe use of central venous catheters (CVCs) in pediatric cancer patients is associated with substantial risk of producing sepsis. The treatment of catheter‐related infections has generally consisted of antibiotic administration with or without catheter removal. The authors report the first published experience using intraluminal hydrochloric acid (HCl) instillation as an adjunct to systemic antimicrobials in the management of catheter‐related infections in children with cancer.METHODSAll episodes of intraluminal instillation of 2 M HCl in oncology patients at The Children's Hospital at Westmead between December 1994 and August 2000 were reviewed. Episodes of HCl use were identified from a prospectively maintained infection data base. Successful treatment was defined as no recurrence of infection and no need for CVC removal in the 100 days after HCl administration.RESULTSForty‐two episodes of HCl instillation were evaluated that occurred in children in whom blood cultures remained positive despite 48 hours of appropriate, systemic antibiotics and formed the basis of this review. All patients had in situ a surgically placed, subcutaneously tunneled CVC. The combination of systemic antibiotic therapy and HCl instillation was successful in eradicating infection in 67% of infection episodes in this patient cohort. The catheter salvage rate was 83% in patients with isolated Gram‐negative infections, 75% in patients with isolated fungemia, and 50% in patients with isolated Gram‐positive infections.CONCLUSIONSThe results suggest that HCl instillation is a useful adjunct to systemic antibiotic therapy, enabling both catheter salvage and eradication of antibiotic‐refractory catheter‐related infection. Cancer 2004. © 2004 American Cancer Society.
Efficacy of MitoTracker Green™ and CMXrosamine to measure changes in mitochondrial membrane potentials in living cells and tissues
Authors: Pendergrass W. , Wolf N. , Poot M. 
Published: August 2004

AbstractBackgroundChloromethyl‐X‐rosamine (CMXRos) and MitoTracker Green (MTG) have proved to be useful dyes with which to measure mitochondrial function. CMXRos is a lipophilic cationic fluorescent dye that is concentrated inside mitochondria by their negative mitochondrial membrane potential (MMP). MTG fluorescence has been used as a measure of mitochondrial mass independent of MMP. The fluorescence ratio of the two dyes is a relative measure of the MMP independent of mitochondrial mass. Because MTG was recently reported to be sensitive to MMP, we have reevaluated the effects of loss of MMP on MTG and CMXRos fluorescence, using both flow cytometry and laser scanning confocal microscopy (LSCM).MethodsUsing flow cytometry, the relative fluorescence of CMXRos, R123, and MTG was determined in human lymphoblastoid cell lines (LCLs) with or without carbonyl cyanide p‐trifluoromethoxylphenyl‐hydrazone (FCCP), used to collapse the MMP. LSCM analysis was also used to evaluate the effect of FCCP on MTG and CMXRos fluorescence of mouse cells and viable lenses in culture. The cytotoxicity of the dyes was determined using flow analysis of endogenous NADH fluorescence. The sensitivity of MTG fluorescence to H2O2 was also evaluated using flow cytometry.ResultsCMXRos fluorescence was dependent on MMP, whereas MTG fluorescence was not affected by MMP, using either flow or LSCM. Specific staining of mitochondria was seen with both dyes in all cell types tested, without evidence of cytotoxicity, as determined by NADH levels. H2O2 damage slightly increased MTG staining of cells.ConclusionsOur results indicate that CMXRos is a nontoxic sensitive indicator of relative changes in MMP, whereas MTG is relatively insensitive to MMP and oxidative stress, using both flow and LSCM analyses, provided optimal staining conditions are used. In addition, these dyes can be useful for the study of mitochondrial morphology and function in whole tissues, using LSCM. © 2004 Wiley‐Liss, Inc.
Characterization of cell‐cycle progression and growth of WB‐F344 normal rat liver epithelial cells following gamma‐ray exposure
Authors: Gerashchenko Bogdan I. , Azzam Edouard I. , Howell Roger W. 
Published: August 2004

AbstractBackgroundApparently normal rat liver epithelial cells (WB‐F344) have been widely used in studies pertaining to carcinogenesis. Ionizing radiation, a well known carcinogen, is known to perturb cell‐cycle progression in a dose‐dependent manner, thereby causing delay in cell proliferation. However, for WB‐F344 cells, there is a paucity of such data, which are of substantial importance in understanding their radiation response. Here, the distribution of phases in the cell‐cycle and the proliferation ability of WB‐F344 cells are characterized at various time points after the cells have been irradiated with different doses of γ‐rays.MethodsAfter WB‐F344 cells reached 100% confluence, they were trypsinized and suspended at 3.5 × 105 cells/ml in culture medium. Cells were irradiated in suspension with 137Cs γ‐rays at doses from 1–10 Gy. After irradiation, 1 × 105 cells were plated into 60 × 15‐mm culture dishes and incubated at 37°C, with 2% CO2 and 98% air. At 12, 24, 36, 48, and 60 h postirradiation, cells were harvested, counted, and subjected to flow cytometric cell‐cycle analysis.ResultsGrowth curves of WB‐F344 cells irradiated with γ‐rays started to separate at 36 h postirradiation. By 60 h postirradiation, the growth curves for each of the 10 absorbed doses were distinctly separated. Drastic redistributions of control and irradiated cells within G0/G1‐, S‐, and G2/M‐phases of the cell cycle were observed during the first 36 h of cell growth. At each time point postirradiation, cell‐cycle phase profiles of irradiated cells were altered in a dose‐dependent manner. In general, there was a strong correlation between the percentage of G2/M‐phase cells and absorbed dose, with the exception of 24 h postirradiation. The percentage of G2/M‐phase cells increased as a function of time postirradiation, suggestive of delays in the passage of cells through the G2 cell‐cycle checkpoint.ConclusionsThis work provides a general description of cell cycle redistribution and repopulation kinetics of WB‐F344 cells at various times postirradiation of quiescent cells that were subsequently allowed to proliferate. In general, growth inhibition and delays in progression through G2/M‐phase correlated well with radiation dose. These data should be of considerable significance in the design of experiments that examine the radiation response of these cells. © 2004 Wiley‐Liss, Inc.
High‐throughput laser‐mediated in situ cell purification with high purity and yield
Authors: Koller Manfred R. , Hanania Elie G. , Stevens Janine , Eisfeld Timothy M. , Sasaki Glenn C. , Fieck Annabeth , Palsson Bernhard Ø. 
Published: August 2004

AbstractBackgroundTechnologies for purification of living cells have significantly advanced basic and applied research in many settings. Nevertheless, certain challenges remain, including the robust and efficient purification (e.g., high purity, yield, and sterility) of adherent and/or fragile cells and small cell samples, efficient cell cloning, and safe purification of biohazardous cells. In addition, existing purification methods are generally open loop and exhibit an inverse relation between cell purity and yield.MethodsAn automated closed‐loop (i.e., employing feedback control) cell purification technology was developed by building upon medical laser applications and laser‐based semiconductor manufacturing equipment. Laser‐enabled analysis and processing has combined high‐throughput in situ cell imaging with laser‐mediated cell manipulation via large field‐of‐view optics and galvanometer steering. Laser parameters were determined for cell purification using three mechanisms (photothermal, photochemical, and photomechanical), followed by demonstration of system performance and utility.ResultsPhotothermal purification required approximately 108 W/cm2 at 523 nm in the presence of Allura Red, resulting in immediate protein coagulation and cell necrosis. Photochemical purification required approximately 109 W/cm2 at 355 nm, resulting in apoptosis induction over 4 to 24 h. Photomechanical purification required more than 1010 W/cm2 independent of wavelength, resulting in immediate cell lysis. Each approach resulted in high efficiency purification (>99%) after a single operation, as demonstrated with eight cell types. An automated closed‐loop process to re‐image and irradiate remaining targets in situ was implemented, resulting in improved purification (99.5–100%) without decreasing cell yield or affecting sterility in this closed system. Efficient purification was demonstrated with B‐ and T‐cell mixtures over a wide range of contaminating cell percentages (0.1–99%) and cell densities (104‐106/cm2). Efficient cloning of 293T cells based on fluorescence with green fluorescent protein after plasmid transfection was also demonstrated.ConclusionsIn situ laser‐mediated purification was achieved with nonadherent and adherent cells on the automated laser‐enabled analysis and processing platform. Closed‐loop processing routinely enabled greater than 99.5% purity with a greater than 90% cell yield in sample sizes ranging from 101 to 108 cells. Throughput ranged from approximately 103 to 105 total cells/s for contaminating percentages ranging from 99% to 0.1%, respectively. © 2004 Wiley‐Liss, Inc.
Exercise as a therapeutic intervention for the prevention and treatment of insulin resistance
Authors: Hawley John A. 
Published: August 2004

AbstractDuring the past half‐century, there has been a dramatic increase in the incidence of obesity, insulin resistance and type 2 diabetes. A hallmark feature of these conditions is impaired glucose tolerance (IGT). Cross‐sectional and retrospective epidemiological studies have provided direct evidence that a lack of physical activity is strongly associated with IGT. Indeed, physical inactivity is an independent risk factor for insulin resistance and type 2 diabetes. The primary defect(s) in the development of whole‐body insulin resistance remain unclear. However, during the past decade significant progress has been made towards an understanding of the molecular basis underlying the beneficial effects of exercise training in stimulating the entry of glucose into insulin‐sensitive tissues. Accordingly, it is now well accepted that regular physical exercise offers an effective therapeutic intervention to improve insulin action in skeletal muscle in insulin‐resistant individuals. This review provides evidence that physical inactivity is significantly associated with IGT and directly contributes to the cascade of events that lead to the expression of the ‘exercise‐deficient phenotype’ associated with insulin resistance and type 2 diabetes. In contrast, exercise training will be shown to significantly reduce the risk of developing insulin resistance by improving glucose tolerance and insulin action in individuals predisposed to develop type 2 diabetes. Several putative mechanisms for enhanced glucose uptake after exercise training will be discussed. A determination of the underlying biological mechanisms that result from exercise training is essential in order to define the precise variations in physical activity that result in the most desired effects on targeted risk factors, and to aid in the development of such interventions. Copyright © 2004 John Wiley & Sons, Ltd.
Diminished transcription of chromosome arm 4q is inversely related to local spreading of hepatocellular carcinoma
Authors: Dykema Karl J. , Furge Kyle A. 
Published: August 2004

AbstractTo identify transcriptional features associated with local spreading of hepatocellular carcinoma (HCC), regional expression biases were determined from the gene expression profiles of solitary HCC tumors and of HCC tumors associated with additional intrahepatic lesions and/or portal vein involvement. Regional expression biases are genetic intervals in which gene expression is coordinately changed. Often, but not always, a regional expression bias indicates an underlying chromosomal aberration. This study demonstrated that the presence or absence of a regional expression bias on chromosome arm 4q can predict the presence or absence of intrahepatic spread/portal vein involvement in 83% of cases analyzed (n = 40). These results suggest that the transcriptional state of 4q may be a marker for local spreading of HCC and that a more detailed genetic/epigenetic characterization of this locus may provide additional insights into HCC development. © 2004 Wiley‐Liss, Inc.
Determination of the Dimerization Equilibrium Constants of Omeprazole and Pirkle's Alcohol through Optical‐Rotation Measurements
Authors: Baciocchi Renato , Juza Markus , Classen Jörg , Mazzotti Marco , Morbidelli Massimo 
Published: August 2004

AbstractA new procedure to measure the equilibrium constants for the dimerization (homochiral and heterochiral) reactions of enantiomers in solution was applied to two different compounds, namely omeprazole and Pirkle's alcohol, both in CHCl3. This procedure is based on the measurement of the optical rotation of the solution as a function of its composition, which exhibits a nonlinear dependence on the enantiomer enrichment. Such nonlinearity depends on the extent of dimerization, and it is a strong effect in the case of omeprazole, whose equilibrium constants are 14.0±3.5 l/mol and 25.2±4.0 l/mol for the formation of homochiral and of heterochiral dimers, respectively. Pirkle's alcohol exhibits a weaker effect that allows only to estimate the order of magnitude of these constants, i.e., ca. 0.10 and 0.34 l/mol, respectively.
Efficient Synthesis of α,β‐Epoxy Carbonyl Compounds in Acetonitrile: Darzens Condensation of Aromatic Aldehydes with Ethyl Chloroacetate
Authors: Wang Zong‐Ting , Xu Li‐Wen , Xia Chun‐Gu , Wang Han‐Qing 
Published: August 2004

AbstractThe Darzens reaction of ethyl 2‐chloroacetate (1) with aromatic aldehydes 2 in the presence of polymer‐supported or nonsupported quaternary ammonium salts proceeds under mild conditions by phase‐transfer catalysis to give the corresponding epoxides 3 in satisfactory yields (Tables 1 and 2). With both MeCN as solvent and polystyrene‐supported catalysts, diastereoselective Darzens reactions proceed in excellent yields and short times, with a fair degree of stereoinduction.
Three New Homologous 3‐Alkyl‐1,4‐benzoquinones from the Fruiting Bodies of Daldinia concentrica
Authors: Qin Xiang‐Dong , Liu Ji‐Kai 
Published: August 2004

AbstractA new homologous series of 3‐alkyl‐5‐methoxy‐2‐methyl‐1,4‐benzoquinones (1–3), with chain lengths of C21 to C23, were isolated from the fruiting bodies of Daldinia concentrica, together with five known compounds. The molecular structures were established by spectroscopic methods.
Aurophilic towards H‐Bonding Interactions in Phosphine‐pyrazolato‐gold(I) Complexes: Luminescence Studies and Crystal Structure of {3,5‐Bis[4‐(octyloxy)phenyl]‐1H‐pyrazolato‐κN1}(triphenylphosphine)gold{3,5‐Bis[4‐(octyloxy)phenyl]‐1H‐pyrazole} ([Au(pz)(PPh3)]⋅(Hpz))
Authors: Ovejero Paloma , Cano Mercedes , Campo José A. , Heras José V. , Laguna Antonio , Crespo Olga , Pinilla Elena , Torres M. Rosario 
Published: August 2004

AbstractCompounds [{Au(pz)(PPh3)}2] (pz=3,5‐disubstituted pyrazolato; R=BuOC6H4 (bp), 1; R=C8H17OC6H4 (op), 2; R=C6H13OC6H4 (hp), 3) were easily obtained by reaction of [Au(NO3)(PPh3)] and the corresponding pyrazolato ligand. They exhibit similar NMR patterns, their ESI‐MS or FAB‐MS data being in agreement with a monomeric molecular formulation [Au(pz)(PPh3)]. By contrast, 1 crystallizes as the dimer [{Au(pz)(PPh3)}2] and exhibits aurophilic Au ⋅⋅⋅Au contacts, while crystallization of 2 in CH2Cl2/hexane gives rise to compound 4, [Au(pz)(PPh3)]⋅(Hpz). The X‐ray structure of 4 was solved, showing a H‐bond interaction between the monomer of 2 and Hpz. Reactions between [{Au(pz)(PPh3)}2] and their corresponding 1H‐pyrazole (Hpz) were also explored. Compounds 1–3 exhibit luminescence in the solid state. Their emission spectra are reported and analyzed.
Der Mechanismus der Alken‐Ozonolyse – eine kritische Betrachtung
Authors: Schank Kurt 
Published: August 2004

AbstractThe Mechanism of Alkene Ozonolysis – a Critical Examination. Alkene ozonolyses have been carried out in experimental organic chemistry for more than a century, and a lucid description of the underlying reaction mechanism has been developped and integrated in most chemistry textbooks. Nevertheless, there are a great number of exceptions hard to rationalize by the accepted mechanism. Attempts in the past to give more‐convincing answers to this problem failed. Therefore, the search for an alternative mechanistic model without contradictions is compelling. The present paper offers a redox model based upon the known properties of ozone both as a strong oxidant and an O‐atom‐transferring agent, especially when reacted with alkenes of sufficiently high electron density to act as reducing partners.
Phosphorus‐Nitrogen Compounds: Novel Spirocyclic Phosphazene Derivatives. Structure of 3,3″‐Propane‐1,3‐diylbis[4′,4′,6′,6′‐tetrachloro‐3,4‐dihydrospiro[1,3,2‐benzoxazaphosphorine‐2,2′λ5‐[4λ5,6λ5][1,3,5,2,4,6]triazatriphosphorine]]
Authors: Bilge Selen , Natsagdorj Amgalan , Demiriz Şemsay , Çaylak Nagihan , Kılıç Zeynel , Hökelek Tuncer 
Published: August 2004

AbstractThe reactions of N2O2‐donor‐type aminopodands1–3with trimer N3P3Cl6led to the novel spirocyclic phosphazene derivatives4–10(Scheme). Compounds4–7and8–10are the first examples of the substituted spiro‐ansa‐spiro and spiro‐bino‐spiro phosphazene derivatives, respectively. The pyrrolidinyl‐substituted phosphazene derivatives7and10were synthesized from5and9, respectively, with an excess of pyrrolidine. The reaction of aminopodand3(R(CH2)4) with N3P3Cl6in dry THF afforded only spiro‐ansa‐spiro phosphazene6. The molecular structure of compound9was determined by X‐ray diffraction: it shows the novel spiro‐bino‐spiro phosphazene architecture.
Seven New Norditerpenoid Alkaloids from Spanish Consolida orientalis
Authors: Alva Alenguer , Grandez Maritza , Madinaveitia Alberto , de la Fuente Gabriel , Gavín José A. 
Published: August 2004

AbstractSeven new norditerpenoid alkaloids named 1‐O‐demethyltricornine (1), 14‐O‐benzoyltakaosamine (2), 1‐O,19‐didehydrotakaosamine (3), 14‐O‐demethyldelboxine (4), all belonging to the lycoctonine‐type alkaloids, and 8‐O‐methylconsolarine (5), 14‐O‐deacetylpubescenine (6), and 18‐O‐benzoyl‐14‐O‐deacetyl‐18‐O‐demethylpubescenine (7), these belonging to the rare group of the 6‐epilycoctonine‐type alkaloids, were isolated from the aerial parts of Consolida orientalis (Gay) Schröd. The structures of the new compounds were elucidated by 1D‐ and 2D‐NMR and HR‐EI‐MS. Moreover, 37 known norditerpenoid alkaloids (lycoctonine‐type) were isolated and identified by comparing their spectral data with those reported in the literature.