bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of vancomycin, daptomycin, fosfomycin, tigecycline, and ceftriaxone on Staphylococcus epidermidis biofilms
Authors: Hajdu Stefan , Lassnigg Andrea , Graninger Wolfgang , Hirschl Alexander M. , Presterl Elisabeth 
Published: April 2009

AbstractInfection of medical implanted material is associated with considerable morbidity and costs. In the following work, we investigated the effects of vancomycin, daptomycin, fosfomycin, tigecycline, and ceftriaxone on biofilms formed by Staphylococcus epidermidis isolates causative for implant infection and catheter‐associated bacteremia. Biofilms were studied using the static microtiter plate model and incubated with the antibiotics increasing the concentration from 1× to 128× the minimal inhibitory concentration (MIC) of the respective isolate tested. To quantify the reduction of the biomass, the optical density ratio (ODr) of stained biofilms and the number of growing bacteria were determined. Incubation of the staphylococcal biofilms with the antibiotics decreased the biofilm ODr (at baseline = 1) for ceftriaxone (0.83 ± 0.48) but minimally only for fosfomycin (0.96 ± 0.64), daptomycin (1.05 ± 0.59), tigecycline (1.18 ± 0.66), and vancomycin (0.98 ± 0.44) at exceedingly high concentrations of 128 × MIC. The significant reduction of the bacterial growth was not achieved for all antibiotics, not even at the highest concentrations tested. Using higher doses of the antibiotics may be of some value in the treatment of biofilm‐associated infections, although effects are seen only at clinically unachievable doses. However, to eradicate the staphylococcal biofilm, additional measures like debridement and/or removal of the implant are needed. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:1361–1365, 2009
Visible Raman spectroscopy for the discrimination of olive oils from different vegetable oils and the detection of adulteration
Authors: El‐Abassy R. M. , Donfack P. , Materny A. 
Published: April 2009

AbstractWe have investigated the potential of Raman spectroscopy with excitation in the visible spectral range (VIS Raman) as a tool for the classification of different vegetable oils and the quantification of adulteration of virgin olive oil as an example. For the classification, principal component analysis (PCA) was applied, where 96% of the spectral variation was characterized by the first two components. A significant similarity between sunflower oil and extra‐virgin olive oil was found using this approach. Therefore, sunflower oil is a potential candidate for adulteration in most commercially available olive oils. Beside the classification of the different vegetable oils, we have successfully applied Raman spectroscopy in combination with partial least‐squares (PLS) regression analysis for very fast monitoring of adulteration of extra‐virgin olive oil with sunflower oil. Different mixtures of extra‐virgin olive oil with three different sunflower oil types were prepared between 5 and 100% (v/v) in 5% increments of sunflower oil. While in the present context the adulteration usually refers to the addition of reasonable amounts of the adulterant (given the similarity with the basic product), we show that the technique proposed can also be used for trace analysis of the adulterant. Without using techniques like surface‐enhanced Raman scattering (SERS), a quantitative detection limit down to 500 ppm (0.05%) could be achieved, a limit irrelevant for adulteration in commercial terms but significant for trace analysis. The qualitative detection limit even was at considerably lower concentration values. Based on PCA, a clear discrimination between pure extra‐virgin olive oil and olive oil adulterated with sunflower oil was achieved. The adulterant content was successfully determined using PLS regression with a high correlation coefficient and small root mean‐square error for both prediction and validation. Copyright © 2009 John Wiley & Sons, Ltd.
Study of the vibrational spectra of (CH3)3GeCl from experimental and DFT calculations
Authors: Roldán María Lorena , Brandán Silvia Antonia , Navarro Amparo , Ben Altabef Aída 
Published: April 2009

AbstractNew infrared (for gas and liquid phase) and Raman (for liquid) spectra were measured for the chlorotrimethylgermane to obtain a complete assignment of its fundamental modes. The measurement of the low‐temperature infrared spectrum together with the application of Fourier self‐deconvolution to the Raman spectra resolves the CH vibrational modes into their components. The Rauhut and Pulay scaled quantum mechanical (SQM) force field methodology and the wavenumber‐linear scaling (WLS) method were used to predict the vibrational spectra as a guide to the assignment of the fundamental bands. A quantum mechanical analysis was carried out to obtain the harmonic force field. Copyright © 2009 John Wiley & Sons, Ltd.
Simultaneous determination of 103 pesticide residues in tea samples by LC‐MS/MS
Authors: Huang Zhiqiang , Zhang Ying , Wang Libing , Ding Li , Wang Meilin , Yan Hongfei , Li Yongjun , Zhu Shaohua 
Published: April 2009

AbstractA simple and sensitive method was developed and validated for the simultaneous determination of 103 pesticide residues in tea by LC‐MS/MS. For the analysis of the pesticide with polarity, thermal lability or low volatility, this LC‐MS/MS method has an advantage over GC. In this work, residual pesticides were extracted from the tea sample with ACN and then purified using Carb‐NH2 SPE cartridges. Using the multiple reaction monitoring mode, the pesticides were quantified and identified by the most abundant and characteristic fragment ions. The recoveries obtained for each pesticide ranged between 65 and 114% at three spiked concentration levels. The intra‐day precisions were lower than 19.6%. Good linear relationships were observed with the correlation coefficients r2 >0.996 for all analytes. The established method was successfully applied to the determination of pesticide residues in real tea samples.
LC‐MS of novel narcoepileptics and related substances
Authors: Nageswara Rao Ramisetti , Shinde Dhananjay D. , Ramesh Venna , Srinivas Ragampeta 
Published: April 2009

AbstractModafinil, adrafinil and their related substances were synthesized and analyzed by RP‐LC with ESI‐MS/MS. The ionization mode, polarity, cone voltage, and chromatographic conditions were evaluated. The optimum LC‐MS conditions to obtain fragment ions indispensable for identification of the structures were described. The bulk drugs purity of modafinil and adrafinil was evaluated on Kromasil C18 column with ACN/0.02 M ammonium acetate as mobile phase in gradient elution mode at 30°C. The method was found to be suitable not only for monitoring the reactions during the process development but also for quality assurance of modafinil and adrafinil.
SFE kinetics of bioactive compounds from Helianthus annuus L.
Authors: Casas Lourdes , Mantell Casimiro , Rodríguez Miguel , Torres Ascensión , Macías Francisco A. , Martínez de la Ossa Enrique J. 
Published: April 2009

AbstractThe kinetics of the supercritical fluid extraction of bioactive compounds from sunflower using CO2 as solvent were studied in order to establish an efficient method for this extraction. The influence of time of extraction at different solvent flow rates was investigated. The extraction pressure and temperature were optimized in previous studies and these values used were 400 bar and 50°C. The extraction yields and the bioactivity levels of the extracts were also analysed. The results indicate that the most appropriate extraction time is between 120 and 180 min depending on the solvent flow and the pretreatment of the sample. The dried sample extracted at 40 g/min, the congealed sample extracted at the same flow and 180 min, and the dried sample extracted at 25 g/min for 120 min showed the best activity profiles. The extractions were carried out in a pilot plant with an extraction vessel with a capacity of 2 L.
Quantitation of imidazo[1,2‐a]quinoxaline derivatives in human and rat plasma using LC/ESI‐MS
Authors: Khier Sonia , Moarbess Georges , Deleuze‐Masquefa Carine , Solassol Isabelle , Margout Delphine , Pinguet Frédéric , Bonnet Pierre‐Antoine , Bressolle Françoise M. M. 
Published: April 2009

AbstractSince several years, our group developed quinoxalinic compounds. Among the synthesized compounds, in the imidazo[1,2‐a]quinoxaline series, EAPB0203 has shown interesting activities both on melanoma and lymphoma. The structure of EAPB0203 has been modulated and a new compound, EAPB0503, exhibits an in vitro cytotoxic activity on melanoma cancer cell line 7–9 times higher than EAPB0203. We validated an LC/ESI‐MS method to simultaneously quantify EAPB0503 and its metabolite EAPB0603 in human and rat plasma. Chromatography was performed on a C8 Zorbax eclipse XDB column with a mobile phase consisting of acetronitrile and formate buffer gradient elution. LC‐MS data were acquired in SIM mode at m/z 305, 291, and 303 for EAPB0503, EAPB0603, and the internal standard, respectively. The drug/internal standard peak area ratios were linked via quadratic relationships to concentrations (low range: 5–300 μg/L, high range: 100–1000 μg/L). The method is precise (precision, ⪇14%) and accurate (recovery, 92–113%). Mean extraction efficiencies, >72% for each analyte, were obtained. The lower LOQs were 5 μg/L. This highly specific and sensitive method was successfully used to investigate plasma concentrations of EAPB0503 and EAPB0603 in a pharmacokinetic study carried out in rat and would also be useful in clinical trials at a later stage.
Removal of endocrine‐disrupting compounds from water using macroporous molecularly imprinted cryogels in a moving‐bed reactor
Authors: Le Noir Mathieu , Plieva Fatima M. , Mattiasson Bo 
Published: April 2009

AbstractHighly efficient removal of endocrine‐disrupting compounds (EDCs) such as 17β‐estradiol (E2), 4‐nonylphenol (NP) and atrazine from water was achieved using a novel macroporous adsorption medium. The medium consisted of a macroporous poly(vinyl alcohol) (PVA) cryogel with molecularly imprinted polymer (MIP) particles embedded in it. The MIP was prepared using E2, NP and atrazine as templates. The macroporous composite molecularly imprinted cryogels were formed inside the open‐ended protective shells, known as Kaldnes carriers. These adsorbents (defined as Macroporous Gel Particles, MGPs) were evaluated on the removal of E2, NP and atrazine from water using different column configurations, namely column filled with the MGPs (packed‐bed column) and in moving‐bed reactors (defined here as moving‐bed MGPs reactor). Complete binding (> 99%) of E2 from a spiked aqueous solution (1 mg/L) was achieved using E2‐MIP/MGPs in a moving‐bed MGPs reactor at the retention time in the reactor of 4 min, while only 77% was bound to the nonimprinted medium (NIP/MGPs). Similar results were also obtained for the adsorption medium imprinted with atrazine. All contaminants studied (E2, atrazine and NP) were effectively removed from water at low (environmentally relevant) concentrations by the respective adsorption medium.
Instrumental planar chromatographic method for determination of carbamazepine in human serum
Authors: Mennickent Sigrid , Fierro Ricardo , Vega Mario , de Diego Marta , Godoy C. Gloria 
Published: April 2009

AbstractAn instrumental planar chromatographic (HPTLC) method for quantification of carbamazepine in human serum was developed using liquid‐liquid extraction with dichloromethane, fluorescence activation with perchloric acid 60%/ethanol/water (1:1:1, v/v) and fluorescence detection. Planar chromatographic separation was performed on precoated silica gel F254 HPTLC plates using a mixture of ethyl acetate/toluene/methanol/acetic acid glacial (5:4:0.5:0.5, v/v) as mobile phase. Densitometric detection was done at 366 nm. The method was validated for linearity, precision and accuracy. Linear calibration curves in the range of 3 and 20 ng/μL showed correlation coefficient of 0.998. The intra‐assay and inter‐assay precision, expressed as the RSD, were in the range of 0.41–1.24% (n = 3) and 2.17–3.17% (n = 9), respectively. The LOD was 0.19 ng, and the LOQ was 0.57 ng. Accuracy, calculated as percentage recovery, was between 98.98 and 101.96%, with a RSD not higher than 1.52%. The method was selective for the active principle tested. In conclusion, the method is useful for quantitative determination of carbamazepine in human serum.
Simultaneous extraction of tocotrienols and tocopherols from cereals using pressurized liquid extraction prior to LC determination
Authors: Milagros Delgado‐Zamarreño M. , Bustamante‐Rangel Myriam , Sierra‐Manzano Sergio , Verdugo‐Jara Marcela , Carabias‐Martínez Rita 
Published: April 2009

AbstractTocopherols and tocotrienols have been simultaneously determined in food samples using a rapid and simple analytical method including pressurized liquid extraction (PLE) and LC with electrochemical detection. Separation was carried out on a Phenomenex Synergi 4 μm Hydro‐RP 80A column, using a solution of 2.5 mM acetic acid/sodium acetate in methanol/water (99:1, v/v) as mobile phase at a flow rate of 1.0 mL/min. Column temperature was maintained at 30°C. Detection was performed by coulometric detection at 500 mV except for (β+γ)‐tocotrienol, in wheat and rye samples, which was at +350 mV. A palm oil containing a relatively large amount of γ‐tocotrienol and lower concentrations of α‐ and δ‐tocotrienols and α‐ and γ‐tocopherols was used to provide reference retention times for the tocotrienols. Analyte quantification was performed using the external standard method. The calibration equations of tocopherols were used to quantify both tocopherols and their corresponding tocotrienols. The extraction recoveries obtained using the optimized PLE conditions were in the 80–114% range, with RSDs lower than 15%. The method was successfully applied to the determination of tocotrienols and tocopherols in cereal (wheat, rye, barley, maize and oat) and palm oil samples.
Development and validation of an HPLC method for the determination of seven penicillin antibiotics in veterinary drugs and bovine blood plasma
Authors: Samanidou Victoria F. , Giannakis Dimitrios E. , Papadaki Antonia 
Published: April 2009

AbstractHerein a quantitative method for the determination of seven penicillins in bovine plasma and veterinary drugs has been developed. Amoxicillin (AMO), ampicillin (AMP), penicillin G (PENG), penicillin V (PENV), oxacillin (OXA), cloxacillin (CLO) and dicloxacillin (DICLO) were separated on a Perfectsil ODS‐2 (250×4 mm, 5 μm) column, using gradient elution, with a mobile phase of 0.1% v/v TFA and ACN–methanol (90:10 v/v). PDA detection was used at 240 nm. Penicillins were isolated from bovine plasma by SPE on Lichrolut RP‐18 cartridges with mean recoveries from 85.7 to 113.5%. Colchicine (3 ng/μL) was used as an internal standard. The developed method was validated in terms of selectivity, linearity, accuracy, precision, stability and sensitivity. Repeatability (n = 5) and between‐day precision (n = 5) revealed RSD < 12%. The detection limits in the bovine plasma were estimated as 18 ng for AMO and AMP, 25 for PENG, PENV and OXA, 3 ng for CLO and 12 ng for DICLO. Spiked plasma samples were stable for 1 wk, except for AMP and CLO, which were stable for 3 wk and OXA for 4 wk. AMO, PENG and PENV were stable for two freeze–thaw cycles, OXA, CLO and DICLO for four, while AMP only for one.
Kinetics of acid degradation of proton pump inhibitors in the presence of a thiol
Authors: Al‐Matar Ali Kh. , El‐Eswed Bassam , Tutunji Maha F. 
Published: April 2009

AbstractAn in vitro investigation of the kinetics of the complex system of acid‐catalyzed conversions and subsequent reactions of proton pump inhibitors (PPIs; omeprazole, lansoprazole and pantoprazole) was carried out using differential pulse polarography at the static mercury drop electrode. Reactions were investigated in the presence of 2‐mercaptoethanol, in solutions buffered to pH values ranging from 2.0 to 5.0. The first‐order reaction network was proposed for all conversions. The rate of degradation of PPIs and subsequent reactions with 2‐mercaptoethanol were found to follow the following general order: lansoprazole > omeprazole > pantoprazole. The rate of conversion of PPIs into sulfenic acid was found to be directly dependent on the basicity of benzimidazole nitrogen of PPIs, which determines the electrophilic reactivity of the adjacent carbon (C2). The rate of conversion of the sulfenic acid of PPIs into the disulfide (the inhibition reaction) was found to be dependent on the electrophilicity of the sulfur atom of the sulfenic acid. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 498–506, 2009
Rate constants of the gas‐phase reactions of OH radicals with trans‐2‐hexenal, trans‐2‐octenal, and trans‐2‐nonenal
Authors: Gao Tingting , Andino Jean M. , Rivera Carlos C. , Márquez Misaela Francisco 
Published: April 2009

AbstractThe rate constants of the gas‐phase reaction of OH radicals with trans‐2‐hexenal, trans‐2‐octenal, and trans‐2‐nonenal were determined at 298 ± 2 K and atmospheric pressure using the relative rate technique. Two reference compounds were selected for each rate constant determination. The relative rates of OH + trans‐2‐hexenal versus OH + 2‐methyl‐2‐butene and β‐pinene were 0.452 ± 0.054 and 0.530 ± 0.036, respectively. These results yielded an average rate constant for OH + trans‐2‐hexenal of (39.3 ± 1.7) × 10−12 cm3 molecule−1 s−1. The relative rates of OH+trans‐2‐octenal versus the OH reaction with butanal and β‐pinene were 1.65 ± 0.08 and 0.527 ± 0.032, yielding an average rate constant for OH + trans‐2‐octenal of (40.5 ± 2.5) × 10−12 cm3 molecule−1 s−1. The relative rates of OH+trans‐2‐nonenal versus OH+ butanal and OH + trans‐2‐hexenal were 1.77 ± 0.08 and 1.09 ± 0.06, resulting in an average rate constant for OH + trans‐2‐nonenal of (43.5 ± 3.0) × 10−12 cm3 molecule−1 s−1. In all cases, the errors represent 2σ (95% confidential level) and the calculated rate constants do not include the error associated with the rate constant of the OH reaction with the reference compounds. The rate constants for the hydroxyl radical reactions of a series of trans‐2‐aldehydes were compared with the values estimated using the structure activity relationship. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 483–489, 2009
Kinetics of gas‐phase reactions of CH3OCH2CF3, CH3OCH3, CH3OCH2CH3, CH3CH2OCH2CH3, and CHF2CF2OCH2CF3 with NO3 radicals at 298 K
Authors: Chen L. , Uchimaru T. , Kutsuna S. , Tokuhashi K. , Sekiya A. , Okamoto H. 
Published: April 2009

AbstractRate constants for the gas‐phase reactions of CH3OCH2CF3 (k1), CH3OCH3 (k2), CH3OCH2CH3 (k3), and CH3CH2OCH2CH3 (k4) with NO3 radicals were determined by means of a relative rate method at 298 K. NO3 radicals were prepared by thermal decomposition of N2O5 in a 700–750 Torr N2O5/NO2/NO3/air gas mixture in a 1‐m3 temperature‐controlled chamber. The measured rate constants at 298 K were k1 = (5.3 ± 0.9) × 10−18, k2 = (1.07 ± 0.10) × 10−16, k3 = (7.81 ± 0.36) × 10−16, and k4 = (2.80 ± 0.10) × 10−15 cm3 molecule−1 s−1. Potential energy surfaces for the NO3 radical reactions were computationally explored, and the rate constants of k1–k5 were calculated according to the transition state theory. The calculated values of rate constants k1–k4 were in reasonable agreement with the experimentally determined values. The calculated value of k5 was compared with the estimate (k5 < 5.3 × 10−21 cm3 molecule−1 s−1) derived from the correlation between the rate constants for reactions with NO3 radicals (k1–k4) and the corresponding rate constants for reactions with OH radicals. We estimated the tropospheric lifetimes of CH3OCH2CF3 and CHF2CF2OCH2CF3 to be 240 and >2.4 × 105 years, respectively, with respect to reaction with NO3 radicals. The tropospheric lifetimes of these compounds are much shorter with respect to the OH reaction. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 490–497, 2009
Harmonic scalpel in the treatment of Zenker's diverticulum
Authors: Fama Anthony F. , Moore Eric J. , Kasperbauer Jan L. 
Published: April 2009

AbstractObjectives/Hypothesis:To describe the transoral treatment of Zenker's diverticulum with a harmonic scalpel and review the initial outcomes of patients treated with this technique.Study Design and Methods:Retrospective study of 25 patients with symptomatic Zenker's diverticula who were treated endoscopically with the harmonic scalpel (Ethicon Endo‐Surgery, Inc, Cincinnati, OH). Electronic medical records were reviewed. Extracted data included outpatient clinic notes, operative reports, hospital summaries, and follow‐up visits.Results:All identified patients (N = 25) were treated successfully and safely with the harmonic scalpel. All patients were observed overnight, and 21 (84%) were dismissed the day after surgery. One patient with a history of cardiac disease had a non–ST‐elevation myocardial infarction, one patient had aspiration pneumonia, and two patients had chest pain (both stayed for complete evaluations with negative findings). One patient had subcutaneous emphysema. No patients had hemorrhage, infection, mediastinitis, or death in the postoperative period. The average length of follow‐up was 10.3 months. One patient had a recurrent diverticulum that was treated with an open surgical technique.Conclusions:Various treatment options are available for Zenker's diverticulum. There has been a trend toward less invasive techniques, and the harmonic scalpel is one useful treatment option. This review demonstrates that the harmonic scalpel is a safe and effective alternative. Longer follow‐up time is needed to assess long‐term success and incidence of recurrence with this new technique. Laryngoscope, 2009
Use of ionic liquid for the enzyme‐catalyzed polymerization of phenols
Authors: Zaragoza‐Gasca Pedro , Villamizar‐Gálvez Omar J. , García‐Arrazola Roeb , Gimeno Miquel , Bárzana Eduardo 
Published: April 2009

AbstractIonic liquid and buffer mixture media are first reported in the peroxidase‐catalyzed polymerization of phenol. Yield of 100% with molecular weights of 7000 KDa, as assessed by size‐exclusion chromatography (SEC), were attained using 1‐butyl‐3‐methylimidazolium tetrafluoroborate–buffer mixtures with added hydrogen peroxide. The simplicity of the process and the low vapor pressure of the solvent media allow an eco‐friendly alternative to the general synthesis of polyphenolic‐type biopolymers. Evidence for the consequent polyphenol (PPO) was obtained from solid‐state 13C cross‐polarization magic angle spinning (CP‐MAS) NMR spectroscopy and FT‐IR. Copyright © 2009 John Wiley & Sons, Ltd.
Eisen und Eisenmangel aus medizin‐ und pharmaziehistorischer Sicht. Die Maske des Mars
Authors: Müller Irmgard 
Published: April 2009

AbstractÄhnlich wie bei den Avitaminosen war auch bei den Eisen‐Mangelkrankheiten der Weg zu ihrer Entschlüsselung reich an Umwegen und von vielen Rückschlägen, Missverständnissen und Irrgängen gezeichnet. Die Vorstellung, dass etwas nicht Vorhandenes, eine negative Entität, eine Krankheit hervorbringen sollte, lag lange Zeit außerhalb des ärztlichen Denkens, das gewohnt war, in konkreten Substraten mit quantitativen Begriffen sich auf Spurensuche zu begeben.
Eisen‐Stoffwechselstörungen. Diagnose und Therapie
Authors: Heimpel Hermann , Bommer Martin 
Published: April 2009

AbstractEisen gehört zu den für die vitalen Körperfunktionen aller höheren Tiere notwendigen “Spurenelemente”. Innerhalb dieser Gruppe nimmt Eisen insofern eine Sonderstellung ein, als es in vergleichsweise großer Menge vorhanden ist und dass sowohl Mangelzustände als auch klinisch relevante Zustände von Eisen‐Überladung häufiger vorkommen als bei allen anderen Metallen.