bluuebunny/crossref_metadata_2025_split huggingface dataset:
Actin immobilization on chitin for purifying myosin II
Authors: de Souza Marcelle Gomes , Grossi André Luiz , Pereira Elisângela Lima Bastos , da Cruz Carolina Oliveira , Mendes Fernanda Machado , Cameron Luiz Claudio , Paiva Carmen Lucia Antão 
Published: January 2008

AbstractThis article presents our experience on teaching biochemical sciences through an innovative approach that integrates concepts of molecular cell biology and protein chemistry. This original laboratory exercise is based on the preparation of an affinity chromatography column containing F‐actin molecules immobilized on chitin particles for purifying skeletal myosin II. It favors the active learning of protein extraction and purification, the learning of concepts such as muscle contraction, cytoskeleton structure, and its importance for the living cell. This laboratory exercise also promotes learning biotechnological applications of chitin and the applications of protein immobilization in different industrial fields. Furthermore, the activities target the development of laboratorial abilities, problem‐solving skills, and the ability to write a scientific report, following the model of a scientific article. The trials are mainly proposed for either an undergraduate project for advanced students in the life sciences or a postgraduate practical training course. In both the cases, the students must have had biochemistry as part of their regular curriculum. Alternatively, the affinity chromatography method can fit in any regular biochemistry course if active chitin, F‐actin, and a myosin II extract are provided. It is very important to mention that this laboratory exercise can be used even in places where a facility such as ultracentrifugation is lacking. For that, the steps of actin purification are skipped, and actin is commercially obtained. Therefore, it is an adequate approach for the active learning of biochemical and molecular cell biology principles and techniques even in poor countries.
ChemInform Abstract: Njaoamines G (Ia) and H (Ib), Two New Cytotoxic Polycyclic Alkaloids and a Tetrahydroquinolone (II) from the Marine Sponge Neopetrosia sp.
Authors: Sorek Hagit , Rudi Amira , Benayahu Yehuda , Kashman Yoel 
Published: January 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Simulation of Air Quality using an ISCST3 Dispersion Model
Authors: Sharma Sumit , Chandra Avinash 
Published: January 2008

AbstractUrban air quality is an issue of major concern across many cities in India. In particular, high levels of particulate matter (both SPM and RSPM) are responsible for noncompliance to air quality standards. Air quality modeling is an effective tool to simulate the air quality of a region and to predict air quality concentrations under different scenarios. Kanpur city which is a top‐ten urban conglomerate in India (based on population) is chosen for the application of the ISCST3 model and simulation of air quality. Sectored emission loads are estimated for transport, industrial, power, and domestic sectors, which provide an estimate of the major contributors to air pollution with specific reference to particulate matter, which is a major pollutant of concern. A detailed scenario analysis is carried out to estimate the changes in emissions that would take place due to various interventions. Dispersion modeling is carried out using the ISCST3 model, to estimate the concentrations of SPM all over the city under different scenarios. Emission inventory and meteorological data served as input to the model, and the air quality is predicted for various seasons and intervention scenarios. The modeled values for the scenario without intervention results in an underestimation of 48%, which is due to unaccountable or unidentified sources, trans‐boundary movement of SPM, and model calibration errors. To overcome the error, the model is calibrated with the observed values and results are obtained for other scenarios using the calibration factor. The paper demonstrates only the research direction currently used to simulate air quality in Indian cities. However, further refinement and research is required before it could be used for more accurate predictions.
Fine Particles (PM2.5) in Residential Areas of Lucknow City and Factors Influencing the Concentration
Authors: Barman S. C. , Singh Ramesh , Negi M. P. S. , Bhargava S. K. 
Published: January 2008

AbstractUrban populations are exposed to a high level of fine and ultrafine particles from motor vehicle emissions which affect human health. To assess the hourly variation of fine particle (PM2.5) concentration and the influence of temperature and relative humidity (RH) on the ambient air of Lucknow city, monitoring of PM2.5 along with temperature and RH was carried out at two residential locations, namely Vikas Nagar and Alambagh, during November 2005. The 24 h mean PM2.5 concentration at Alambagh was 131.74 μg/m3 and showed an increase of 13.74%, which was significantly higher (p < 0.05) than the Vikas Nagar level. The 24 h mean PM2.5 on weekdays for both locations was found to be 142.74 μg/m3 (an increase of 66.23%) which was significantly higher (p < 0.01) than the weekend value, indicating that vehicular pollution is one of the important sources of PM2.5. The mean PM2.5 at night for all the monitoring days was 157.69 μg/m3 and was significantly higher (p < 0.01) than the daytime concentration (89.87 μg/m3). Correlation and multiple regressions showed that the independent variables, i. e., time, temperature, and RH together accounted for 54%, whereas RH alone accounted for 53% of total variations of PM2.5, suggesting that RH is the best influencing variable to predict the PM2.5 concentration in the urban area of Lucknow city. The 24 h mean PM2.5 for all the monitoring days was found to be higher than the NAAQS recommended by the US‐EPA (65 μg/m3) and can be considered to be an alarming indicator of adverse health effects for city dwellers.
Sedimentary Phosphorus Form Distribution and Cycling in the Littoral Subzones of a Eutrophic Lake
Authors: Liu Honglei , Yin Chengqing , Wang Hongjun , Wang Weidong , Shan Baoqing 
Published: January 2008

AbstractAlgae which bloom in open water and accumulate in the littoral zones may affect the biogeochemical cycle of phosphorus in eutrophic lakes. To determine such effects, a part of the lakeshore with little allochthonous nutrient input in Taihu Lake, China was selected for this field study. Distinct differences in sedimentary P forms were found among the different littoral subzones. The surface sedimentary total phosphorus (TP) content was 655 mg/kg in the eulittoral subzone and 631 to 641 mg/kg in the infralittoral subzone. Both were much higher than that in the profundal zone (410 mg/kg). Calcium‐bound P (Ca‐P) was significantly correlated to exchangeable P (Ex‐P), and they both had the highest contents in the infralittoral subzone and the lowest in the profundal zone. The aluminum‐ and iron‐bound P (Al‐P, Fe‐P) contents decreased from land to water along the ecotone section. Lower Fe/P ratios and higher Al‐P/Fe‐P ratios appeared in the infralittoral subzone, as compared with the profundal zone. This suggested that the accumulated algae could lead to a great deposit of P in the littoral zones. However, the active sedimentary P form transformation in the littoral zones would also result in a partial release of the accumulated P to the overlying water.
Nutrient Recovery from Human Urine Using Pretreated Zeolite and Struvite Precipitation in Combination with Freezing‐Thawing and Plant Availability Tests on Common Wheat
Authors: Ganrot Zsófia , Slivka Andreas , Dave Göran 
Published: January 2008

AbstractThe nutrient rich fractions in wastewater originating from human urine and can be recovered as solids for more efficient recycling, facilitated handling and storage for reuse in agriculture. Freezing and thawing can be used to concentrate the urine nutrients. Phosphorus (P) and nitrogen (N) can be precipitated as struvite [(Mg,Ca)(K,NH4)(PO4)·6H2O] by adding MgO and additional nitrogen can be recovered by using zeolites. The zeolite in this study was pretreated in two ways: (i) washed and (ii) washed and thermally treated. The P recovery was high (> 97%) and the N recovery was ca. 50 to 60%. There was no significant difference in the nitrogen recovery among the different pretreated zeolites or between the pretreated and the untreated zeolite. Freezing had a positive effect on the nutrient concentration. The acute toxicity of the supernatants was tested on Daphnia magna to evaluate the possibilities of discharging the remaining supernatants to a recipient. The supernatants from the frozen treatments and from the unfrozen and washed zeolites were much less toxic than those of the original urine. The minerals acted as slow‐release fertilizers in climate chamber tests on spring wheat.
Behavior of Steroid Hormones and Conjugates During Wastewater Treatment – A Comparison of Three Sewage Treatment Plants
Authors: Schlüsener Michael P. , Bester Kai 
Published: January 2008

AbstractThe fate of the steroid hormones 17 β‐estradiol, estrone, estriol, 16 α‐hydroxyestrone, and β‐estradiol 17‐acetate, the hormone‐conjugates β‐estradiol 3‐sulfate and estrone 3‐sulfate, and the oral contraceptives 17 α‐ethinylestradiol and mestranol were studied during wastewater treatment as wastewater treatment plants are the major source contamination of urban surface waters with steroid hormones. The elimination efficiencies of three different concepts of WWTPs, i. e., activated sludge versus trickling filter, were compared over four weeks at different weather conditions. While larger WWTPs operating on activated sludge eliminated hormones more constantly than smaller WWTPs, heavy rainfall events led to a collapse of the elimination efficiency. By using trickling filter techniques for the treatment of wastewater an elimination of the steroid hormones could not be observed. Additionally, mass flows on a per person basis are compared. In the three experiments, which ran continuously for four weeks each, it turned out that the concentrations of ethinylestradiol and mestranol were below 6 ng/L in all samples. The inflow concentrations were 70 to 82 ng/L (estrone), 17 to 44 ng/L (estradiol), 61 to 130 ng/L (hydroxyestrone), 189 to 255 ng/L (estriol), 10 to 17 ng/L (estrone‐3‐sulfate) and about 28 ng/L (estradiol‐3‐ sulfate). While in the activated sludge treatment plants the elimination of estrone was 90 and 50%, respectively, estrone was formed from precursors in the trickling filter plant. A similar situation occurred for 17β‐estradiol, estrone 3‐sulfate, and estradiol 3‐sulfate. Hydroxyestrone was eliminated with similar efficiencies in all wastewater treatment plants (64 to 82%), as well as estriol (34 to 69%). Accordingly, the emissions of the wastewater treatment plants differed largely and were not attributed to the size of the respective plant, only.
On decoupled time step/subcycling and iteration strategies for multiphysics problems
Authors: Valli A. M. P. , Carey G. F. , Coutinho A. L. G. A. 
Published: January 2008

AbstractThis work investigates partitioned iterative solution of coupled multiphysics systems including subcycling time‐stepping strategies for decoupled subsystems in conjunction with a proportional‐integral‐derivative feedback control algorithm for adaptive time‐step selection. Some basic algorithms are proposed and the total computational effort to integrate to steady state is compared for a representative coupled flow and heat transfer problem to illustrate the approach and assess performance efficiency. Copyright © 2008 John Wiley & Sons, Ltd.
Thermal and mechanical numerical modelling of electric discharge machining process
Authors: Salah Nizar Ben , Ghanem Farhat , Atig Kaïs Ben 
Published: January 2008

AbstractIn electric discharge machining (EDM), the heat gradients caused by the electric discharge create a non‐uniform local thermal expansion on the level of the surface layers of machined materials from where genesis of thermal stresses takes place. These thermal stresses, if exceeding yield stress, can remain and become residual after the cooling of the part. The modelling of these phenomena, during the heating by the electric discharge and the cooling by the dielectric liquid, requires a heat transfer model, the material behaviour identification, a thermo‐mechanical model for the thermal and the residual stress models.This paper presents numerical results concerning the temperature distribution, the thermal and residual stresses of a stable steel material (AISI316L) machined by EDM. Comparison of numerical results with experimental data and numerical results from the literature shows good agreement and is hence quite satisfactory. Copyright © 2008 John Wiley & Sons, Ltd.
Electrochemical Determination of L‐Lactate Using Phenylboronic Acid Monolayer‐Modified Electrodes
Authors: Takahashi Shigehiro , Kurosawa Shiho , Anzai Jun‐ichi 
Published: January 2008

AbstractThe surface of a gold (Au) disk electrode was modified with a self‐assembled monomolecular layer of dithiobis(4‐butylamino‐m‐phenylboronic acid) (DTBA‐PBA) to prepare L‐lactate‐sensitive electrodes. The DTBA‐PBA‐modified electrodes exhibited an attenuated cyclic voltammogram (CV) for the Fe(CN)63− ion in the presence of L‐lactate, as a result of the formation of phenylboronate ester of L‐lactate accompanied with the addition of OH− ion to the boron atom. In other words, the negatively charged DTBA‐PBA monolayer blocked the electrode surface from the access of the Fe(CN)63−/4− ions. Thus, the DTBA‐PBA monolayer‐modified Au electrode can be used for determining L‐lactate on the basis of the change in redox current of Fe(CN)63−/4− ions. The calibration graph useful for determining 1–30 mM L‐lactate was obtained.
Voltammetry of Selenium(+4) in Atmospheric Precipitates
Authors: Zelić Marina 
Published: January 2008

AbstractUsing square‐wave cathodic stripping voltammetry on a hanging mercury drop electrode, selenium(+4) was measured in rainwater samples and snow melts. The ratio of peak currents, obtained from filtered and nonfiltered fractions of the same sample, could be even three, but standard addition method indicates the same initial concentration in both cases. The influence of filtration is explained in terms of decreased surfactant level. From one of the samples, double peaks of unknown origin were obtained. They reflect two irreversible processes which are not fully independent. Possible explanation includes two modifications of the same deposit, formed during accumulation step. The influence of surfactants and/or other organic compounds on the signal of interest could perhaps be useful in various studies of organic matter, dissolved in rainwater or snow melt.
A Facile Preparation of H2O2 Sensors Using Layer‐by‐Layer Deposited Thin Films Composed of Poly(ethyleneimine) and Carboxymethyl Cellulose as Matrices for Immobilizing Hemin
Authors: Wang Baozhen , Du Xiaoyan , Wang Maoqing , Gong Weilei , Anzai Jun‐ichi 
Published: January 2008

AbstractA layer‐by‐layer (LbL) thin film composed of poly(ethyleneimine) (PEI) and carboxymethyl cellulose (CMC) was prepared on the surface of a gold (Au) disk electrode and the LbL layer was impregnated with hemin to fabricate amperometric hydrogen peroxide (H2O2) sensors. Hemin can be easily immobilized in the LbL layer by immersing the LbL film‐coated electrode in the hemin solution. The hemin‐modified electrode thus prepared exhibited an amperometric response to H2O2 on the basis of the electrochemical reduction catalyzed by hemin. The output current of the hemin‐modified electrode depended on the concentration of H2O2 over the range of 0.005–1.0 mM. Thus, the LbL film composed of PEI and CMC was found to be an excellent material for the facile preparation of hemin‐based H2O2 sensors.
Concentration polarization and nonequilibrium electroosmotic slip in hierarchical monolithic structures
Authors: Nischang Ivo , Höltzel Alexandra , Seidel‐Morgenstern Andreas , Tallarek Ulrich 
Published: January 2008

AbstractThis article illustrates the appearance and electrohydrodynamic consequences of concentration polarization (CP) in hierarchically structured monolithic fixed beds used as stationary phases in CEC and related electrical‐field‐assisted separation techniques. Subject of the investigation are silica‐based monoliths in capillary format with a bimodal pore size distribution. Ion‐permselectivity in the intraskeleton pore space together with diffusive and electrokinetic transport induces depleted and enriched CP zones at the anodic and cathodic interfaces, respectively, of the cation‐selective mesoporous skeleton. The extent of electrical‐field‐induced CP is shown to be governed by the fluid phase ionic strength, which tunes the ion‐permselectivity of the mesoporous monolith skeleton via local electrical double layer overlap, and by the applied electrical field strength, which determines local transport. The analysis of quantitative confocal laser scanning microscopy data, resolving CP on the local skeleton scale, indicates that at sufficiently high field strength a transition from intraskeleton to interskeleton boundary‐layer‐dominated transport of charged species occurs. This transition is correlated to the onset of macroscopically measured, nonlinear EOF velocities, whose occurrence is explained in the framework of a nonequilibrium electroosmotic slip. It is shown that the onset of nonlinear electrokinetics in the system can be tuned by properties of the BGE, particularly buffer pH, which modulates the pH‐dependent surface charge density and consequently the ion‐permselective skeleton's charge selectivity. Finally, the CP dynamics of monolithic and particulate fixed beds are compared, and the observed differences are related to the specific morphologies of the two hierarchical fixed bed structures.
Further Highly Oxygenated Guaiane Lactones from the South China Sea Gorgonian Menella sp.
Authors: Li Liang , Wang Chang‐Yun , Huang Hui , Mollo Ernesto , Cimino Guido , Guo Yue‐Wei 
Published: January 2008

AbstractFour new highly oxygenated guaiane lactones, 1‐epimenverin B (1), menverin F (2), 1‐deoxymenverin F (3), and menverin G (4), together with the two known related analogues menverins B (5) and C (6), were isolated from the South China Sea gorgonian Menella sp. Their structures and relative configuration were elucidated by analysis of spectroscopic data and by comparison with those of known related compounds.
Three Novel Compounds from the Flowers of Bombax malabaricum
Authors: Wu Jun , Zhang Xiao‐Hui , Zhang Shu‐Wei , Xuan Li‐Jiang 
Published: January 2008

AbstractTwo unusual 9′‐norneolignans, bombasin (1) and bombasin 4‐O‐β‐glucoside (2), and a novel D‐gulono‐γ‐lactone derivative, bombalin (3), were isolated from the flowers of Bombax malabaricum, together with the three known compounds dihydrodehydrodiconiferyl alcohol 4‐O‐β‐D‐glucopyranoside (4), trans‐3‐(p‐coumaroyl)quinic acid (5), and neochlorogenic acid (6). Their structures were elucidated by extensive spectroscopic methods as well as chemical transformation. Compounds 1–3 were evaluated against the HGC‐27 gastrointestinal and Hela cervical human cancer cell lines, but all were inactive in both lines (IC50>50 μM).
Synthesis of 4‐(Isothiazol‐3‐yl)morpholines and 1‐(Isothiazol‐3‐yl)piperazines, and Their Inhibitory Activity towards Acetylcholinesterase
Authors: Wolf Janine , Tanarro Camino M. González , Gütschow Michael , Sieler Joachim , Schulze Bärbel 
Published: January 2008

AbstractThe synthesis of novel triaryl‐substituted 4‐(isothiazol‐3‐yl)morpholines 7 and 8, and 1‐(isothiazol‐3‐yl)piperazines 9–13 by reaction of the corresponding isothiazolium salts 5 and 6 with secondary amines in the presence of t‐BuOK in absolute THF is described. Some representatives of the isothiazoles were evaluated as inhibitors of acetylcholinesterase from Electrophorus electricus.
A One‐Pot Synthesis of 1,3‐Dihydro‐1,3,3‐tris(perfluoroalkyl)isobenzofuran‐1‐olates and Their Complete NMR Spectroscopic Analysis on the Basis of 1D and 2D Experiments
Authors: Tyrra Wieland , Scherer Harald , Babadzhanova Lesya A. , Kirij Natalya V. , Yagupolskii Yurii L. , Naumann Dieter , Pantenburg Ingo 
Published: January 2008

AbstractA convenient synthesis of the 1,3‐dihydro‐1,3,3‐tris(perfluoroalkyl)isobenzofuran‐1‐ols 3a,b was elaborated starting from commercially available phthaloyl dichloride and trimethyl(perfluoroalkyl)silanes (Me3SiRf) 1a,b (Rf=CF3, C2F5) in the presence of a fluoride source (Schemes 1 and 3). In a reaction analogous to alkyl Grignard reagents, double chloride substitution by two perfluoroalkyl groups and subsequent addition of one perfluoroalkyl group with concomitant ring closure led to this new class of compounds (Scheme 2). The syntheses of the alcohols and some alcoholates, as well as of the corresponding trimethylsilyl ethers are described. A combination of special 1D and 2D NMR experiments allowed the assignment of all atoms of the new compounds. The solid‐state structure of 1,3‐dihydro‐1,3,3‐tris(trifluoromethyl)isobenzofuran‐1‐ol (3a) was elucidated by X‐ray diffraction methods.
Age‐related and zonal anatomical changes of apparent diffusion coefficient values in normal human prostatic tissues
Authors: Tamada Tsutomu , Sone Teruki , Toshimitsu Shinya , Imai Shigeki , Jo Yoshimasa , Yoshida Koji , Yamamoto Akira , Yamashita Takenori , Egashira Naoto , Nagai Kiyohisa , Fukunaga Masao 
Published: January 2008

AbstractPurposeTo identify age‐related changes and differences in the diffusion of water molecules within the prostate, through diffusion‐weighted imaging (DWI) of the prostate gland in healthy adult Japanese men.Materials and MethodsA total of 114 healthy male volunteers (mean age, 55 years; range, 24–81 years) underwent DWI of the prostate with a single‐shot echo‐planar imaging (EPI) sequence using b‐factors of 0 and 1000 seconds/mm2. Apparent diffusion coefficient (ADC) values of six locations in the peripheral zone (PZ) and two locations in the central gland (CG) were measured and correlations between region and age were examined.ResultsADC values measured within both PZ and CG regions of the prostate showed a uniform distribution, and no significant differences were found between evaluated regions. However, mean ADC values were 1.64 ± 0.27 ×10−3 mm2/second for PZ and 1.26 ± 0.12 ×10−3 mm2/second for CG, representing a significant difference. In addition, significant positive correlations were identified between ADC values for both PZ and CG regions and subject age (r = 0.526, P < 0.0001; r = 0.190, P = 0.0431, respectively).ConclusionADC values within both PZ and CG regions of the prostate increase with age, and this must be taken into consideration when using DWI in the diagnosis of prostate cancer. J. Magn. Reson. Imaging 2008. © 2008 Wiley‐Liss, Inc.