bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis, Characterization, Antioxidant and Antitumor Evaluation of Some New Thiazolidine and Thiazolidinone Derivatives
Authors: Gouda Moustafa A. , Abu‐Hashem Ameen A. 
Published: December 2010

Abstract2‐(2‐Cyano‐acetylamino)‐4,5,6,7‐tetrahydrobenzo[b]thiophene‐3‐carboxylic acid ethyl ester (2) was utilized as a key intermediate for the synthesis of thiocarbamoyl derivative 3 via its reaction with phenyl isothiocyanate. Treatment of 3 with chloroacetyl chloride afforded thiazolidin‐5‐one 4. Compound 7 reacted with different α‐halo carbonyl compounds to give thiazolidine 8a,b, and thiazolidin‐4‐one derivatives 9. Treatment of 4 with the appropriate aromatic aldehyde and tolyl diazonium chloride afforded the corresponding thiazolidin‐5‐one derivatives 5a,b and 6, respectively. The thiazolidin‐4‐one derivative 10 was obtained via the reaction of compound 2 with 2‐mercaptoacetic acid. Finally, the thiazoline 11 was obtained via the reaction of compound 2 with phenyl isothiocyanate/sulfur. The title compounds were characterized by elemental analyses and spectral data. The quantum mechanical calculations for some compounds were accomplished and subjected for antioxidant and antitumor studies, whereas, some of them exhibited promising activities.
Self‐Assembly of 3,6‐Bis(4‐triazolyl)pyridazine Ligands with Copper(I) and Silver(I) Ions: Time‐Dependant 2D‐NOESY and Ultracentrifuge Measurements
Authors: Happ Bobby , Pavlov Georges M. , Altuntas Esra , Friebe Christian , Hager Martin D. , Winter Andreas , Görls Helmar , Günther Wolfgang , Schubert Ulrich S. 
Published: December 2010

AbstractTwo 3,6‐bis(R‐1H‐1,2,3‐triazol‐4‐yl)pyridazines (R=mesityl, monodisperse (CH2CH2O)12CH3) were synthesized by the copper(I)‐catalyzed azide–alkyne cycloaddition and self‐assembled with tetrakis(acetonitrile)copper(I) hexafluorophosphate and silver(I) hexafluoroantimonate in dichloromethane. The obtained copper(I) complexes were characterized in detail by time‐dependent 1D [1H, 13C] and 2D [1H‐NOESY] NMR spectroscopy, elemental analysis, high‐resolution ESI‐TOF mass spectrometry, and analytical ultracentrifugation. The latter characterization methods, as well as the comparison to analog 3,6‐di(2‐pyridyl)pyridazine (dppn) systems and their corresponding copper(I) and silver(I) complexes indicated that the herein described 3,6‐bis(1H‐1,2,3‐triazol‐4‐yl)pyridazine ligands form [2×2] supramolecular grids. However, in the case of the 3,6‐bis(1‐mesityl‐1H‐1,2,3‐triazol‐4‐yl)pyridazine ligand, the resultant red‐colored copper(I) complex turned out to be metastable in an acetone solution. This behavior in solution was studied by NMR spectroscopy, and it led to the conclusion that the copper(I) complex transforms irreversibly into at least one different metal complex species.
Protein‐protein interactions: Making sense of networks via graph‐theoretic modeling
Authors: Pržulj Nataša 
Published: December 2010

AbstractThe emerging area of network biology is seeking to provide insights into organizational principles of life. However, despite significant collaborative efforts, there is still typically a weak link between biological and computational scientists and a lack of understanding of the research issues across the disciplines. This results in the use of simple computational techniques of limited potential that are incapable of explaining these complex data. Hence, the danger is that the community might begin to view the topological properties of network data as mere statistics, rather than rich sources of biological information. A further danger is that such views might result in the imposition of scientific doctrines, such as scale‐free‐centric (on the modeling side) and genome‐centric (on the biological side) opinions onto this area. Here, we take a graph‐theoretic perspective on protein‐protein interaction networks and present a high‐level overview of the area, commenting on possible challenges ahead.
Bovine lactoperoxidase – a versatile one‐ and two‐electron catalyst of high structural and thermal stability
Authors: Banerjee Srijib , Furtmüller Paul G. , Obinger Christian 
Published: December 2010

AbstractLactoperoxidase (LPO), a member of the peroxidase‐cyclooxygenase superfamily, is found in multiple human exocrine secretions and acts as a first line of defense against invading microorganisms by production of antimicrobial oxidants. Because of its ability to efficiently catalyze one‐ and two‐electron oxidation reactions of inorganic and organic compounds, the heme peroxidase is widely used in food biotechnology, cosmetic industry, and diagnostic kits. In order to probe its structural integrity, conformational, and thermal stability, we have undertaken a comprehensive investigation by using complementary biophysical techniques including UV–Vis, circular dichroism and fluorescence spectroscopy as well as differential scanning calorimetry (DSC). The oxidoreductase exhibits a high chemical and thermal stability under oxidizing conditions but is significantly destabilized by addition of DTT. Due to its unique ester bonds between the prosthetic group and the protein as well as six intra‐chain disulfides, unfolding of the central compact (‐helical core occurs concomitantly with denaturation of the heme cavity. The corresponding enthalpic and entropic contributions to the free enthalpy of unfolding are presented. Together with spectroscopic data they will be discussed with respect to the known structure of bovine LPO and homologous myeloperoxidase as well as to its practical application.
Identification of a Napsamycin Biosynthesis Gene Cluster by Genome Mining
Authors: Kaysser Leonard , Tang Xiaoyu , Wemakor Emmanuel , Sedding Katharina , Hennig Susanne , Siebenberg Stefanie , Gust Bertolt 
Published: December 2010

AbstractNapsamycins are potent inhibitors of bacterial translocase I, an essential enzyme in peptidoglycan biosynthesis, and are classified as uridylpeptide antibiotics. They comprise an N‐methyl diaminobutyric acid, an ureido group, a methionine and two non‐proteinogenic aromatic amino acid residues in a peptide backbone that is linked to a 5′‐amino‐3′‐deoxyuridine by an unusual enamide bond. The napsamycin gene cluster was identified in Streptomyces sp. DSM5940 by using PCR probes from a putative uridylpeptide biosynthetic cluster found in S. roseosporus NRRL15998 by genome mining. Annotation revealed 29 hypothetical genes encoding for resistance, regulation and biosynthesis of the napsamycins. Analysis of the gene cluster indicated that the peptide core structure is assembled by a nonlinear non‐ribosomal peptide synthetase (NRPS)‐like mechanism that involves several discrete single or didomain proteins. Some genes could be assigned, for example, to the synthesis of the N‐methyl diaminobutyric acid, to the generation of m‐tyrosine and to the reduction of the uracil moiety. The heterologous expression of the gene cluster in Streptomyces coelicolor M1154 resulted in the production of napsamycins and mureidomycins as demonstrated by LC‐ESI‐MS and MS/MS analysis. The napsamycin gene cluster provides a molecular basis for the detailed study of the biosynthesis of this class of structurally unusual compounds.
An Insight into Artificial Leaves for Sustainable Energy Inspired by Natural Photosynthesis
Authors: Zhou Han , Fan Tongxiang , Zhang Di 
Published: December 2010

AbstractThe development of green sustainable energy to control our carbon‐based energy “addiction” and to reduce atmospheric CO2 emissions is one of the most urgent issues regarding the continued existence of man on planet earth. Among renewable energy resources, solar energy is by far the largest exploitable resource. Photosynthesis provides a blueprint for solar energy conversion and storage in fuels. Natural green leaves capture and convert solar energy into chemical fuel through photosynthesis. The two reactions are the splitting of water into hydrogen and oxygen (water splitting) and the reduction of CO2 into carbohydrates (CO2 reduction). Inspired by natural leaves, constructing artificial leaves by mimicking photosynthesis to capture solar energy, split water into hydrogen and oxygen, and convert atmospheric carbon dioxide, thus producing various forms of environmentally clean fuels, is of high significance. Many major advances in this research area are highlighted in this Minireview. Some typical successful prototypes from natural systems that can be used for the biomimetic design of artificial leaves are particularly emphasized.
Gram‐Scale Synthesis of Magnetically Separable and Recyclable Co@SiO2 Yolk‐Shell Nanocatalysts for Phenoxycarbonylation Reactions
Authors: Park Ji Chan , Lee Hyun Ju , Jung Hyun Seok , Kim Mijong , Kim Hae Jin , Park Kang Hyun , Song Hyunjoon 
Published: December 2010

AbstractCo@SiO2 yolk‐shell nanostructures were fabricated on a gram scale by simple hydrogen reduction of CoO@SiO2 core‐shell nanoparticles without using an etching step. The cobalt core diameters were reduced by the lattice volume contraction of CoO to Co, forming vacancy between the cores and the silica shells. The Co@SiO2 yolk‐shell nanocatalysts were employed for the phenoxycarbonylation of iodobenzene, and exhibited high activity and reusability. The magnetic property of the cobalt cores enabled the facile separation of catalysts from the products.
Effective Decolorization of Azo Dye Utilizing SnO2/CuO/Polymer Films under Simulated Solar Light Irradiation
Authors: Jiang R. , Zhu H.‐Y. , Guan Y.‐J. , Fu Y.‐Q. , Xiao L. , Yuan Q.‐Q. , Jiang S.‐T. 
Published: December 2010

AbstractSnO2/CuO/polymer flexible thin films were prepared by a solution casting technology and characterized by high‐resolution TEM and XRD. The influences of key operational parameters on photocatalytic decolorization of azo dye (Biebrich Scarlet Red, BSR) were investigated systematically. The results showed good crystalline and clear lattice spacings of the novel composite photocatalyst. BSR was bleached effectively and the decolorization efficiency was >98 % in the presence of 1.0 g L–1 photocatalyst under simulated solar light irradiation. The decolorization was more effective in acidic solution with the optimal pH in the range of 4–6. The tested co‐anions in general decreased the decolorization rates by decreasing the adsorption of BSR on the surface of the photocatalyst and reacting with positive hole (h+)/hydroxyl radicals (HO·).
Supercritical CO2 Extraction of Chlorophyll a from Spirulina platensis with a Static Modifier
Authors: Tong Y. , Gao L. , Xiao G. , Pan X. 
Published: December 2010

AbstractSupercritical CO2 extraction with a static modifier was applied to extract chlorophyll a from Spirulina platensis. The effects of the process were investigated by single‐factor and response surface analysis experiments. The optimal process parameters for supercritical CO2 extraction were determined to be: ethanol/water as the modifier, 40 vol.‐% water content in the modifier, 21.2 mL modifier volume, 1 h static soaking time, 2 h dynamic extraction time, 48.7 MPa extraction pressure, 326.4 K extraction temperature, and 10 g min–1 CO2 flow rate. The optimized chlorophyll a extraction yield was 6.84 mg g–1. A comparison of the experimental results suggested that the yield of chlorophyll a by supercritical CO2 extraction with modifier was higher than that obtained by conventional solvent extraction.
Path modelling by sequential PLS regression
Authors: Næs T. , Tomic O. , Mevik B.‐H. , Martens H. 
Published: December 2010

AbstractThis paper presents a new approach to path modelling, based on a sequential multi‐block modelling in latent variables. The approach is explorative and focused on interpretation. The method breaks with standard traditions of estimating all paths using one single modelling. Instead, one separate model is estimated for each endogenous block. Each separate model is constructed by stepwise use of the standard PLS regression on matrices that are orthogonalised with respect to each other. The advantages of the approach are that it can allow for different dimensionality within each block, it is invariant to relative weighting of the blocks and it is based on simple and standard methodology allowing for simple outlier detection, validation and interpretation. No convergence problems are involved and the method can be used for situations with many more variables than samples. An application based on sensory analysis of wines will be used to illustrate the method. Copyright © 2010 John Wiley & Sons, Ltd.
A chemometrical approach to study interactions between ethynylestradiol and an AhR‐agonist in stickleback (Gasterosteus aculeatus)
Authors: Andersson Carin , Lundstedt‐Enkel Katrin , Katsiadaki Ioanna , Holt William V. , Van Look Katrien J.W. , Örberg Jan 
Published: December 2010

AbstractQuantifiable responses in fish, such as induction of certain proteins, can be used as indicators of chemical contamination of waterways. In order to evaluate differences in ethoxyresorufin‐O‐deethylase (EROD) induction capacity of the gill and the liver and effects on organs and biomarker proteins, e.g. gill and liver EROD, hepatosomatic index (HSI), nephrosomatic index (NSI), gonadosomatic index (GSI), spiggin, vitellogenin and sperm motility were analysed in male three‐spined sticklebacks (Gasterosteus aculeatus) exposed for 21 days to β‐naphthoflavone (βNF) alone (Exp 1) or in combination with 17α‐ethynylestradiol (EE2) (Exp 2). The sperm motility variables were studied using computer‐assisted sperm analysis (CASA).Exp 1: Gill EROD activity was significantly induced in fish exposed to ≥1.2 µg/l and hepatic EROD activity in fish exposed to ≥6 µg/l. No significant effect of ßNF on the production of spiggin or vitellogenin or on sperm variables was found.Exp 2: A significant additative effect of EE2 + βNF was shown for gill EROD. A significant antagonistic effect of the two compounds was found on NSI where an increased EE2 concentration led to an increase in NSI while an increased concentration of βNF led to a decreased NSI. Interestingly, the results showed that exposure to intermediate concentrations of EE2 and ßNF led to a significant increase in the sperm variables. In the aquatic environment mixtures of numerous chemicals with oestrogenic activity are present, so if the capacity to induce gill EROD activity is a general property of oestrogen‐acting chemicals, our findings are important. Copyright © 2010 John Wiley & Sons, Ltd.
Rotary cement kiln coating estimator: Integrated modelling of kiln with shell temperature measurement
Authors: Sadighi Sepehr , Shirvani Mansoor , Ahmad Arshad 
Published: December 2010

AbstractCoating thickness protection in the burning zone of a rotary cement kiln during operation is important from the viewpoint of the kiln productivity. In this paper, an integrated model is presented to estimate the coating thickness in the burning zone of a rotary cement kiln by using measured process variables and scanned shell temperature. The model can simulate the variations of the system, thus the impact of different process variables and environmental conditions on the coating thickness can be analysed. The presented steady‐state model derived from heat and mass balance equations uses a plug flame model for simulation of gas and/or fuel oil burning. Moreover, the heat transfer value from shell to the outside is improved by a quasi‐dynamic method. Therefore, at first, the model predicts the inside temperature profile along the kiln, then by considering two resistant nodes between temperatures of the inside and outside, the latter measured by shell scanner, it estimates the formed coating thickness in the burning zone. The estimation of the model was studied for three measured data sets taken from a modern commercial cement kiln. The results confirm that the average absolute error for estimating the coating thickness for the cases 1, 2, and 3 are 3.26, 2.82, and 2.21 cm, respectively.
Removal of Ni(II) Using Cation Exchange Resins in Packed Bed Column: Prediction of Breakthrough Curves
Authors: Gomathi Priya Ponnaiah , Ahmed Basha Chiya , Ramamurthi Veerappan 
Published: December 2010

AbstractSorptive removal of Ni(II) from electroplating rinse wastewaters by cation exchange resin Dueolite C 20 was investigated at the temperature of 30°C under dynamic conditions in a packed bed. The effects of sorbent bed length 0.1–0.2 m, fixed flow rate 6 dm3 min−1, and the initial rinse water concentration (C0) 53.1 mg L−1 on the sorption characteristics of Dueolite C 20 were investigated at an influent pH of 6.5. More than 94.5% of Ni(II) was removed in the column experiments. The column performance was improved with increasing bed height and decreasing the flow rate. The Thomas, Yoon–Nelson, Clark, and Wolborska models were applied to the experimental data to represent the breakthrough curves and determine the characteristic design parameters of the column. The sorption performance of the Ni(II) ions through columns could be well described by the Thomas, Yoon–Nelson, and Wolborska models at effluent‐to‐influent concentration ratios (C/C0) >0.03 and <0.99. Among the all models, the Clark model showed the least average percentage time deviation. The sorptive capacity of electroplating rinse water using Ni(II) was found to be 45.98 mg g−1.
Occurrence of the Antimicrobials Sulfamethoxazole and Trimethoprim in Hospital Effluent and Study of Their Degradation Products after Electrocoagulation
Authors: Martins Ayrton F. , Mallmann Carlos A. , Arsand Daniel R. , Mayer Francieli Martins , Brenner Carla G. B. 
Published: December 2010

AbstractIn this study, an investigation was carried out into the occurrence of sulfamethoxazole (SMX) and trimethoprim (TMP) in the effluent of the university hospital (HUSM) of the UFSM. The degradation of these antimicrobials by the electrocoagulation (EC) process was also examined, in both the aqueous solution and hospital effluent, and a study was conducted in order to identify the subproducts formed. The experiments were optimized through factorial planning and, also, checked by response surface methodology. The best conditions for EC (achieving 58.0% of chemical oxygen demand (COD) reduction) were obtained by using 13 mA cm−2, 500 mg L−1 of NaCl, and 30 mm of interelectrode distance. The quantification of SMX (27.8 µg L−1) and TMP (6.65 µg L−1) in the hospital effluent, and the identification of the degradation products were carried out through liquid chromatography‐mass spectrometry quadrupole linear and ion trapping with electrospray ionization (LC‐ESI‐MS/MS_QTrap). Removals of 88.0% (degradation only) and 33.0% (adsorption only) were achieved for aqueous solutions of SMX and TMP, respectively, under optimized conditions. In hospital effluent samples, fortified with additions of SMX and TMP, corresponding removals of 16.0% (degradation) and 28.0% (adsorption) were achieved. This suggests that the EC process is efficient in degrading SMX in aqueous solution, although the same was not the case with TMP. The degradation products of SMX were identified (m/z 256.0 and 288.5); however, only the latter is mentioned in the literature. Toxicological aspects were not considered in this study.
Determination of Sulfamethoxazole and Trimethoprim and Their Metabolites in Hospital Effluent
Authors: Brenner Carla G. B. , Mallmann Carlos A. , Arsand Daniel R. , Mayer Francieli M. , Martins Ayrton F. 
Published: December 2010

AbstractIn this work, an analytical methodological study was carried out to determine the antimicrobials sulfamethoxazole and trimethoprim, as well as their metabolites, in hospital effluent. The determinations were conducted by liquid chromatography tandem mass spectrometry using a hybrid triple quadrupole‐linear ion trap mass spectrometer (LC‐QqLIT‐MS). The data acquisition was made in selected reaction monitoring (SRM) mode, in which two SRM transitions were monitored to ensure that the target compounds were accurately identified by the information dependent acquisition (IDA) function. The limits of detection (LOD) and quantification (LOQ) were 0.25 and 0.80 µg L−1 for sulfamethoxazole and 0.15 and 0.50 µg L−1 for trimethoprim. The linear range for the SMX was 0.8–100.0 µg L−1 and TMP was 0.5–100.0 µg L−1 on the basis of six‐point calibration curves generated by means of linear regression analysis. The coefficients of the correlation were higher than 0.999, which ensured the linearity of the method. The average concentration of sulfamethoxazole and trimethoprim found in hospital effluent was 27.8 and 6.65 µg L−1, respectively. The analytical methodology employed allowed two metabolites to be identified, N4‐acetyl‐sulfamethoxazole and α‐hydroxy‐trimethoprim. Fragmentation pathways were proposed.
Preparation of Magnetic Hydroxyapatite and Their Use as Recyclable Adsorbent for Phenol in Wastewater
Authors: Wang Xianxiang 
Published: December 2010

AbstractMagnetic hydroxyapatite (HAP), which combined superparamagnetic Fe3O4 nanoparticles and HAP, composite materials were prepared by ultrasound method in this paper. It has also been found that these materials have the ability to adsorb phenol in wastewater. The magnetic materials were investigated by scanning electron microscope, X‐ray diffraction (XRD), Fourier transform infrared spectroscopy, thermal gravimetric analysis, vibrating sample magnetometer, and N2 adsorption in order to elucidate the morphology, structure, and other properties. When the prepared magnetic materials were calcined at 200°C, the prepared Fe3O4 was oxidized to Fe2O3, possessing loose‐shaped holes with a high specific area of 325.2 m2/g, a magnetization intensity of 12.5 emu/g, and the N2 adsorption isotherm belongs to porous adsorption type I. Moreover, the magnetic HAP can adsorb 90% phenol in wastewater. This means that it is an excellent recyclable phenol sorbent for sewage treatment. Experiments confirmed that the Freundlich adsorption isotherms model applies to lower phenol concentrations (0–50 mg/L), while for high phenol concentrations (50–500 mg/L) the Langmuir adsorption isotherms model fits. The magnetic sorbents have the capacity to regenerate after reaching adsorption saturation using ethanol as eluant and external magnetic field as separation unit. The efficiency of adsorption was reduced only by 10% over a six time use period.
Synthesis and Antimicrobial Evaluation of Nitazoxanide‐Based Analogues: Identification of Selective and Broad Spectrum Activity
Authors: Ballard T. Eric , Wang Xia , Olekhnovich Igor , Koerner Taylor , Seymour Craig , Salamoun Joseph , Warthan Michelle , Hoffman Paul S. , Macdonald Timothy L. 
Published: December 2010

AbstractA library composed of nitazoxanide‐based analogues was synthesized and assayed for increased antibacterial efficacy against the pyruvate–ferredoxin oxidoreductase (PFOR) using microorganisms Helicobacter pylori, Campylobacter jejuni and Clostridium difficile. Derivatives were found to recapitulate and improve activity against these organisms and select analogues were tested for their ability to disrupt the PFOR enzyme directly. The library was also screened for activity against staphylococci and resulted in the identification of analogues capable of inhibiting both staphylococci and all PFOR organisms at low micromolar minimum inhibitory concentrations with low toxicity to human foreskin cells.