bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparative study on the interaction of recombinant human soluble catechol‐O‐methyltransferase on some hydrophobic adsorbents
Authors: Passarinha L. A. , Bonifácio M. J. , Queiroz J. A. 
Published: February 2007

AbstractThe main scope of this work is the evaluation and potential application of hydrophobic interaction chromatography in the isolation of recombinant human soluble catechol‐O‐methyltransferase (hSCOMT) from an Escherichia coli cell extract. Therefore, a comparative study on the interaction of recombinant hSCOMT with different hydrophobic adsorbents (butyl‐, octyl‐, phenyl‐ and epoxy‐Sepharose), was developed. The four adsorbents were evaluated in terms of selectivity, recovery and fractionation of recombinant hSCOMT from its Escherichia coli‐free culture broth. Our data shows that the adjustment of the ionic strength on the mobile phase and the type of hydrophobic ligand are the most useful factors for a complete binding of hSCOMT and a selective fractionation of contaminating proteins. The results of these studies demonstrate that, although epoxy‐Sepharose is used as a last resort due to the high salt concentrations needed, hSCOMT bind to the other three resins at low concentrations of ammonium sulfate (≤0.6 m) and eluted just by decreasing the ionic strength on the eluent to 0 m, without loss of specific of activity. The stepwise gradient with 0.6, 0.2, 0.075 and 0 m of ammonium sulfate onto a butyl‐Sepharose media was found to be the most effective in the isolation of hSCOMT, leading to an enzyme solution with a 3.9‐fold increased in specific activity. Since biochemical and structural studies require significant quantities of the enzyme in an active form, the above described approach may give some insight into the optimization and development of new purification strategies of mammalian COMTs. Copyright © 2007 John Wiley & Sons, Ltd.
Permeability of atenolol and propranolol in the presence of dimethyl sulfoxide in rat single‐pass intestinal perfusion assay with liquid chromatography/UV detection
Authors: Venkatesh Gantala , Ramanathan S. , Nair N. K. , Mansor S. M. , Sattar Munavvar Abdul , Khan Md. Abdul Hye , Navaratnam V. 
Published: February 2007

AbstractA simple and sensitive RP‐HPLC‐UV method was developed and validated for simultaneous determination of atenolol and propranolol and subsequently applied to investigate the effect of dimethyl sulfoxide in rat in situ intestinal permeability studies. Atenolol (400 µm) and propranolol (100 µm) were perfused in the small intestine of anaesthetized (pentobarbitone sodium 60 mg/kg, i.p.) male Sprague–Dawley rats either in the presence (1, 3 and 5%) or in the absence of dimethyl sulfoxide. There was no significant alteration (p > 0.05) in the permeability of atenolol and propranolol, which indicated there was no effect of various concentrations of dimethyl sulfoxide (1–5%) on the membrane integrity of the rat intestinal tissues. The analytical method was validated on a C4 column with a mobile phase comprising ammonium acetate buffer (pH 3.5, 0.02 m) and acetonitrile in the ratio of 30:70 (v/v) at a flow rate of 1.0 mL/min. The validated method was found to be accurate and precise and stability studies were carried out at different storage conditions and both analytes were found to be stable. These findings are applicable for determining the absorbability of water‐insoluble drugs and new chemical entities for the purpose of classifying them in the biopharmaceutical classification system. Copyright © 2007 John Wiley & Sons, Ltd.
Rapid determination of cinchocaine in skin by high‐performance liquid chromatography
Authors: Elsayed Mustafa M. A. 
Published: February 2007

AbstractA simple, rapid, accurate, precise and specific analytical method has been developed, validated and applied for determination of cinchocaine in guinea pig and albino rabbit dorsal skins, after in vivo application of cinchocaine formulations. Extraction was performed using a solvent mixture of ethanol and 0.1 M hydrochloric acid (90:10; v/v). Samples were chromatographed on Spheri‐5, RP18 column with a particle size of 5 µm and 220 mm × 4.6 mm i.d. The mobile phase was a mixture of acetonitrile and triethylamine phosphate buffer (pH 2.8; 0.04 M) (60:40, v/v). UV detection was carried out at 247 nm and the run time was 6 min with typical retention time of cinchocaine of 3.63 ± 0.02 min. Specificity was demonstrated, showing that the cinchocaine peak was free of interference from skin endogenous components. The detector response was found to be linear in the concentration range 0.96–56.00 µg/mL with a coefficient of correlation r = 0.99996. The relative standard deviations of within‐ and between‐day analyses were all below 5%. The drug extraction procedure was validated. Satisfactory recoveries with relative standard deviation values below 5% were obtained, indicating efficient quantitative reproducible extraction procedure. Copyright © 2007 John Wiley & Sons, Ltd.
Simultaneous quantification of five anthraquinones in rat plasma by high‐performance liquid chromatography with fluorescence detection
Authors: Yan Dongming , Ma Yueming 
Published: February 2007

AbstractA sensitive high‐performance liquid chromatographic method with fluorescence detection (excitation 435 and emission 515 nm) was established and validated for quantification of five anthraquinones (aloe‐emodin, rhein, emodin, chrysophanol and physcion) in rat plasma. Following a single‐step liquid–liquid extraction, the analytes and internal standard (1,8‐dihydroxyanthraquinone) were separated on a reversed‐phase C18 column with water–phosphoric acid–methanol as mobile phase at a flow rate of 1 mL/min. The linear ranges of the calibration curves were 6.5–1300 ng/mL for aloe‐emodin, 20–4000 ng/mL for rhein, 40–8000 ng/mL for emodin, 15–3000 ng/mL for chrysophanol and 13–2600 ng/mL for physcion. The lower limit of quantification was 6.5 ng/mL for aloe‐emodin, 20 ng/mL for rhein, 40 ng/mL for emodin, 15 ng/mL for chrysophanol and 13 ng/mL for physcion. The mean accuracy was 94.3–105.1% for aloe‐emodin, 90.3–108.8% for rhein, 92.6–106.7% for emodin, 95.8–103.8% for chrysophanol and 98.7–101.2% for physcion. The within‐batch and between‐batch precisions were ≤5.5% and ≤13.4%, respectively. This method is suitable for determining the five anthraquinones in plasma simultaneously and thus investigating the pharmacokinetics of anthraquinones from Xiexin decoction in rats. Copyright © 2007 John Wiley & Sons, Ltd.
Simultaneous determination of aminothiols, ascorbic acid and uric acid in biological samples by capillary electrophoresis with electrochemical detection
Authors: Yao Xiao , Wang Yuting , Chen Gang 
Published: February 2007

AbstractA method based on capillary electrophoresis with electrochemical detection has been employed for the separation and determination of homocysteine, cysteine, reduced glutathione, ascorbic acid and uric acid. Effects of several important factors such as the acidity and concentration of the running buffer, separation voltage, injection time and detection potential were investigated to acquire the optimum conditions. The detection electrode was a 500 µm diameter platinum disk electrode at a working potential of +1.05 V (vs saturated calomel electrode). The five analytes were well separated within 10 min in a 50 cm long fused silica capillary at a separation voltage of 18 kV in a 100 mm phosphate buffer (pH 7.8). The relation between peak current and analyte concentration was linear over about 3 orders of magnitude with the detection limits (S/N = 3) ranging from 0.83 to 2.58 µm. The proposed method was successfully applied to determine cysteine, reduced glutathione, ascorbic acid and uric acid in human whole blood and rat brain tissues with satisfactory assay results and should find a wide range of bioanalytical applications. Copyright © 2007 John Wiley & Sons, Ltd.
Role of regulator of G‐protein signaling 2 (RGS2) in periodontal ligament cells under mechanical stress
Authors: de Araujo Rui M. Santos , Oba Yasuo , Moriyama Keiji 
Published: February 2007

AbstractMechanical stress is thought to regulate the expression of genes in the periodontal ligament (PDL) cells. Using a microarray approach, we recently identified a regulator of G‐protein signaling 2 (RGS2) as an up‐regulated gene in the PDL cells under compressive force. The RGS protein family is known to turn off G‐protein signaling. G‐protein signaling involves the production of cAMP, which is thought to be one of the biological mediators in response to mechanical stress. Here, we investigated the role of RGS2 in the PDL cells under mechanical stress. PDL cells derived from the ligament tissues of human premolar teeth were cultured in collagen gels and subjected to static compressive force. Compressive force application time‐dependently enhanced RGS2 expression and intracellular cAMP levels. To examine the interrelationship between RGS2 and cAMP, the PDL cells were treated with 2′,5′‐dideoxyadenosine (DDA), an inhibitor of adenyl cyclase, or antisense S‐oligonucleotide (S‐ODN) to RGS2 under compressive force. DDA dose‐dependently inhibited RGS2 stimulated by compressive force. Blockage of RGS2 by antisense S‐ODN elevated the cAMP levels compared with controls. These results indicate that cAMP stimulates RGS2 expression, which in turn leads to a decrease in the cAMP production by inactivating the G‐protein signaling in the mechanically stressed PDL cells. Copyright © 2007 John Wiley & Sons, Ltd.
QTc‐interval abnormalities in a forensic population
Authors: Girgis Sobhi , Huckstep Bernard , Oakley Janette , Ferriter Michael , Nikolaou Vassilis 
Published: February 2007

AbstractBackground Antipsychotic drugs have been linked to sudden death among psychiatric patients, with a suggestion that prolongation of the QT‐interval detectable on a standard electrocardiogram may be linked to fatal cardiac arrhythmias in these circumstances. Patients in secure forensic psychiatric facilities may be particularly likely to be on high‐dose antipsychotic medication, and yet, as far as the authors are aware, no study of QT‐intervals among such patients has been reported.Aim To investigate the prevalence of QT‐interval abnormalities and associated known risk factors for fatal cardiac arrhythmias in a sample of forensic patients.Method Participants had a 12‐lead electrocardiogram taken at 50 mm/s. Information was collected on their age, gender, psychiatric diagnosis, history of cardiovascular, liver and kidney diseases, and smoking, on all medications and on history of seclusion over the previous 12 months. Analysis was carried out using binary logistic regression.Results Lower rates of QT‐interval abnormalities than might be expected for this population were found. It was also found that a high dose of antipsychotics was associated with QTc prolongation (Adjusted OR = 9.5, 95% CI 2.6–34.2), a result consistent with previous literature.Conclusion Forensic patients need not be at increased risk of QTc abnormality provided risk factors are properly managed. A high dose of antipsychotic medication increases the risk of QTc prolongation. Copyright © 2007 John Wiley & Sons, Ltd.
What do you think you're looking at? Investigating social cognition in young offenders
Authors: Jones Alice P. , Forster Alice S. , Skuse David 
Published: February 2007

AbstractAim This small study was designed to assess the nature and severity of social‐cognitive deficits in antisocial adolescents.Method Thirty‐seven boys aged 15–18 from a Young Offenders Institute and Community College participated. They were asked to complete a test of general intellectual ability and self‐rating of social competence as well as tasks from the Skuse Schedules for the Assessment of Social Intelligence.Results Young offenders were poor at recognizing the facial expression of anger, regardless of intellectual ability. They could not accurately identify the direction of another's eye gaze. Their performance on theory of mind tasks, however, was unimpaired.Conclusion These preliminary findings imply selective impairment in the cognitive appraisal of threat, which may contribute to social maladjustment. Further such study of social cognition among young offenders is indicated. Copyright © 2007 John Wiley & Sons, Ltd.
Mortality among homicide offenders: a retrospective population‐based long‐term follow‐up
Authors: Lindqvist Per , Leifman Anders , Eriksson Anders 
Published: February 2007

AbstractBackground Empirical data on homicide and homicide offenders are needed in the ongoing discussion on violence and crime prevention. One issue, insufficiently investigated, is the post‐trial life course of homicide offenders.Aim To examine whether the mortality rate, as well as cause and manner of death, of homicide offenders is different from the general population.Method An incidence cohort of Swedish homicide offenders from 1970 to 1980 (n = 153) was re‐examined by computerized record linkage with the National Cause‐of‐Death Register for the period between trial and 1 October 2002, i.e. 22–32 years after the offence. Death certificates were analysed, and standard procedures for calculating Standard Mortality Rate (SMR) and survival analysis were employed.Results Half of the study subjects had died by 2002. The overall mortality rate was about three times higher than that of the general population. In particular, the risk of suicide was salient.Implications It can be argued that offenders' self‐neglect and self‐contempt merge with public and professional views, predisposing to an increased risk of premature death. Copyright © 2007 John Wiley & Sons, Ltd.
The validity of the Violence Risk Appraisal Guide (VRAG) in predicting criminal recidivism
Authors: Kröner Carolin , Stadtland Cornelis , Eidt Matthias , Nedopil Norbert 
Published: February 2007

AbstractIntroduction The VRAG is an actuarial risk assessment instrument, developed in Canada as an aid to estimating the probability of reoffending by mentally ill offenders.Aim To test the predictive validity of the VRAG with a German sample.Method The predictive validity of the VRAG was tested on a sample of 136 people charged with a criminal offence and under evaluation for criminal responsibility in the forensic psychiatry department at the University of Munich in 1994–95. The predicted outcome was tested by means of ROC analysis for correlation with the observed rate of recidivism between discharge after the 1994–95 assessment and the census date of 31 March 2003. Recidivism rate was calculated from the official records of the National Conviction Registry.Results Just over 38% of the sample had reoffended by 2003. Their mean time‐at‐risk was 58 months (SD 3.391; range 0–115 months). The VRAG yielded a high predictive accuracy in the ROC analysis with an AUC of 0.703. For a constant time‐at‐risk < = 7 years, the predicted probability and observed rates of recidivism correlated significantly with Pearson's r = 0.941.Conclusions The validity of the VRAG was replicated with a German sample. The VRAG yielded good predictive accuracy, despite differences in sample and outcome variables compared with its original sample. Copyright © 2007 John Wiley & Sons, Ltd.
Balloon angioplasty for branch pulmonary artery stenosis—Cutting balloons
Authors: De Giovanni Joseph V. 
Published: February 2007

AbstractPulmonary artery stenosis can cause right ventricular strain but intrapulmonary lesions are inaccessible to surgery; moreover, some are also resistant to high pressure balloon angioplasty. An alternative is the use of microsurgical devices mounted on balloons for transvenous delivery, including cutting balloons. The current literature is sparse but seems to indicate a role for cutting balloons in specific situations. The higher cost of these devices does not merit routine use instead of high pressure balloons but a randomised controlled study is underway to address this issue. Until the results of this become available, the role of cutting balloons for pulmonary artery stenosis remains limited to specific situations. The recommendations for the safe use of these devices must be adhered to by all operators. © 2007 Wiley‐Liss, Inc.
Selective Catalysis and Nanoscience: An Inseparable Pair
Authors: Zecchina Adriano , Groppo Elena , Bordiga Silvia 
Published: February 2007

AbstractSelective catalysts can be considered as nanomachines designed to perform the synthesis of molecules with high reaction activity and high selectivity. These properties arise from a precise control of the structure of the active sites, of the three‐dimensional environment and of their relationship. In both homogeneous and heterogeneous catalysts the active site three‐dimensional environment ensemble is always a complex structure resembling the tuneable structure of enzymes, which are the most efficient catalysts optimized by nature over billions of years. To illustrate this concept the structure of a few homogeneous and heterogeneous catalysts for alkenes hydrogenation and for olefin polymerization are chosen and discussed as examples.
Carbon Dioxide Hydrogenation Catalyzed by a Ruthenium Dihydride: A DFT and High‐Pressure Spectroscopic Investigation
Authors: Urakawa Atsushi , Jutz Fabian , Laurenczy Gábor , Baiker Alfons 
Published: February 2007

AbstractReaction pathways during CO2 hydrogenation catalyzed by the Ru dihydride complex [Ru(dmpe)2H2] (dmpe=Me2PCH2CH2PMe2) have been studied by DFT calculations and by IR and NMR spectroscopy up to 120 bar in toluene at 300 K. CO2 and formic acid readily inserted into or reacted with the complex to form formates. Two formate complexes, cis‐[Ru(dmpe)2(OCHO)2] and trans‐[Ru(dmpe)2H(OCHO)], were formed at low CO2 pressure (<5 bar). The latter occurred exclusively when formic acid reacted with the complex. A RuH⋅⋅⋅HOCHO dihydrogen‐bonded complex of the trans form was identified at H2 partial pressure higher than about 50 bar. The trans form of the complex is suggested to play a pivotal role in the reaction pathway. Potential‐energy profiles along possible reaction paths have been investigated by static DFT calculations, and lower activation‐energy profiles via the trans route were confirmed. The H2 insertion has been identified as the rate‐limiting step of the overall reaction. The high energy of the transition state for H2 insertion is attributed to the elongated RuO bond. The H2 insertion and the subsequent formation of formic acid proceed via Ru(η2‐H2)‐like complexes, in which apparently formate ion and Ru+ or Ru(η2‐H2)+ interact. The bond properties of involved Ru complexes were characterized by natural bond orbital analysis, and the highly ionic characters of various complexes and transition states are shown. The stability of the formate ion near the Ru center likely plays a decisive role for catalytic activity. Removal of formic acid from the dihydrogen‐bonded complex (RuH⋅⋅⋅HOCHO) seems to be crucial for catalytic efficiency, since formic acid can easily react with the complex to regenerate the original formate complex. Important aspects for the design of highly active catalytic systems are discussed.
Feststoffextraktion
Authors: Bart H.‐J. , Schmidt M. 
Published: February 2007

AbstractDie Feststoffextraktion aus Pflanzen ermöglicht eine Gewinnung unter Strukturerhaltung komplexer chemischer Verbindungen. Am Beispiel der Extraktion von Triterpensäuren aus Salbei werden dazu mögliche Extrahierphasen (überkritische, tensidhaltige etc.) diskutiert. Klassische organische Lösungsmittelgemische zeigen die höchsten Extraktionskapazitäten, doch kann eine Verbesserung der Extraktionsausbeute (Löslichkeit, Selektivität) durch Zusätze (Lösungsvermittler, Puffer etc.) erreicht werden.
Biokraftstoffe – Eine langfristige Energiequelle
Authors: Wille A. 
Published: February 2007

AbstractBei der Entwicklung und dem Einsatz von Biokraftstoffen handelt es sich um ein ebenso spannendes wie weitgefächertes Thema, das in den letzten Jahren eine Dynamik erfahren hat, die einen ganzen Wissenschafts‐ und Wirtschaftszweig geschaffen hat. Dieser wird durch die Verknappung der globalen fossilen Energieträgerbasis für eine energiehungrige Weltgemeinschaft angetrieben. Eine Vielzahl von Technologien und Einsatzmöglichkeiten von Biomasse ist vonnöten, um die Energiematrix sinnvoll und nachhaltig zu ergänzen. Viele Forschungsvorhaben kreisen heute um die Frage nach der Weiterentwicklung der Biokraftstoffe, um von der ersten zur zweiten Generation zu kommen. Dafür ist es notwendig, technisch machbare und makroökonomisch verträgliche Verfahren zu entwickeln, die nicht nur die Energieausbeute des Kohlenstoffspeichers Biomasse weiter steigern, um die fossile Energie zu ergänzen und teilweise zu ersetzen, sondern auch, um damit einen Beitrag zur Verbesserung des globalen Klimas zu ermöglichen.
Multidisciplinary frontiers in breast cancer management
Authors: Singletary S. Eva 
Published: February 2007

AbstractThe current paradigm of breast cancer management may be altered significantly over the coming years by the adoption of new treatment schema and devices outside of the surgical arena. New advances in breast cancer imaging will improve our ability to detect early‐stage disease but also will assist in monitoring treatment outcomes and support the development of nonsurgical ablation techniques. These advances, some already in use, include a 3‐dimensional adaptation of digital mammography, color Doppler ultrasonography that can visualize neovascularization in growing tumors, contrast‐enhanced magnetic resonance imaging with improved accuracy for the detection of occult cancers, a specialized approach to positron emission tomography designed for use on the breast, and the development of nanoparticle contrast agents that can be visualized with near‐infrared light. Systemic therapy, which revolutionized breast cancer management in the last half of the 20th century, is being reconceptualized, with attention turning to adjusting the timing of chemotherapy. Dose‐dense regimens are being tested, and there also is interest in so‐called metronomic chemotherapy in which very low doses are given on a very frequent schedule, resulting in reduced toxicity and treatment outcomes that reflect an antiangiogenic mode of action. Finally, the possibility of a breast cancer vaccine continues to intrigue and excite physicians and patients alike, with the promise of enlisting the body's own immune system to seek out and destroy cancer cells and/or prevent the development of future disease. It will be important for surgeons to stay aware of all developments that may improve the care of their patients and to be true surgical oncologists rather than merely surgical technicians. Cancer 2007. © 2007 American Cancer Society.
A novel circuit element and its application in signal amplification
Authors: Gift Stephan J. G. , Maundy Brent 
Published: February 2007

AbstractA novel IC‐based current amplifier configuration for signal‐processing applications that can be configured using commercially available integrated circuit elements is presented. The circuit is accurate, has a wide bandwidth and can drive grounded loads. It utilizes a CCII+ type current conveyor with its input circuit in the feedback loop of a current feedback amplifier (CFA). In the current amplifying mode, the circuit has a low input impedance over a broad frequency range which never rises above the low input impedance of the inverting input of the associated CFA. Experimental results obtained using AD844s confirm the results derived. Copyright © 2007 John Wiley & Sons, Ltd.