bluuebunny/crossref_metadata_2025 huggingface dataset:
Method to determine molecular diffusivities of phenol in bitumen
Authors: Tang Joseph S. , Zhang Pei Xin
Published: March 2009

Phenols, carboxylic acids and other water‐soluble compounds in bitumen constitute a potential source of groundwater pollution. To assess the extent of damages that could result from a spill, a water extraction method was used to determine the molecular diffusion of phenol in bitumen. This method involves the diffusion of phenol through bitumen into the flowing water in a well‐stirred cell. From the phenol concentration in water, the phenol flux and hence the phenol diffusion coefficient in bitumen can be deduced. An approximate dimensionless solution was obtained by de‐coupling the diffusional flux from the concentration buildup in water. The phenol diffusion coefficient was determined to be 4.0 ± 0.3 × 10−8 m2/s at 22°C. The derivation and the properties of the dimensionless solution were also discussed in the paper.
Reductant flow control for NOX removal from lean exhaust gases
Authors: Krijnsen Henrike C. , Van Kooten Wijnand E. J. , Calis Hans Peter A. , Bleek Cor M. Van Den
Published: March 2009

This review article describes and discusses the literature on reducing agent control systems for NOx emission reduction in the exhaust gas of full lean‐burn engines. The literature can be classified as feedback, feedforward, feedforward‐feedback, feedforward/feedforward‐feedback and periodical dosing control systems, which can be further classified as classical, override, co‐ordinated, constrained and split systems or a combination of those.

As long as reproducible, fast and cheap NOx sensors are not commercially available, the control system should be an inferential feedforward or feedforward‐feedback system supplied with constraints for environmental and economical reasons. For future applications an oxidation catalyst downstream of the deNOx catalyst should be applied to convert any inevitable reductant slip, due to modelling errors, to harmless compounds.
Simple shear, hysteresis and yield stress in biofluids
Authors: And Ning Sun , De Kee Daniel
Published: March 2009

Biofluids such as blood, as well as other structured materials, exhibit rather complex rheological behaviour. In this paper, starting from a first‐order kinetic model, we developed a constitutive equation and studied its applicability to model biofluids. In particular, we studied the cases of simple shear flow, hysteresis and yield stress. Model predictions were successfully compared with experimental data on complex materials such as blood and a penicillin suspension.
Optimization of amino acids production from waste fish entrails by hydrolysis in sub and supercritical water
Authors: Kang Kilyoon , Quitain Armando T. , Daimon Hiroyuki , Noda Reiji , Goto Naohiro , Hu Hong‐Ying , Fujie Koichi
Published: March 2009

A resource recovery technique using sub‐ and supercritical water hydrolysis was applied to convert waste fish entrails into amino acids. The effect of reaction parameters such as temperature and time necessary for the control of reaction towards optimum yield of amino acids was investigated. Results showed a maximum yield of total amino acids (137 mg/g dry fish) from waste fish entrails at T= 523 K (P = 4 MPa) and reaction time of 60 min in a batch reactor. Under supercritical conditions (e. g., T= 653 K, P = 45 MPa), the yield decreases due to rapid decomposition compared to production rate of amino acids. The results suggest operation of the system at short reaction time and mild temperature condition.
A new pressure drop model for flow‐through orifice plates
Authors: Liu Shijie , Afacan Artin , Masliyah Jacob H.
Published: March 2009

This study was carried out to seek a suitable model to describe flow through orifices. The model of developing flow through short ducts was found to be adequate. There were two free parameters in the model equation involving the normalized pressure drop and Reynolds number. Experiments were performed using two Plexiglas tanks separated by an orifice. The liquid level height variation with time was recorded. A unique parametric estimation technique was used to determine the two free parameters from the dynamic liquid level data. It was found that direct use of the experimental data (liquid level heights) is the best option in correlating the experimental data with the model. The correlation fits well with the present and literature experimental data quite well. It was found that the variation of the pressure drop with the flow rate is linear when the flow is weak, where the orifice Reynolds number is less 10. When the flow is strong, the ratio of the pressure drop to the flow rate becomes linearly related to the flow rate. These two limits are identical to those for flow in porous media.
Hydrodynamic modelling of the axial density profile in the riser of a low‐density circulating fluidized bed
Authors: Smolders Kathleen , Baeyens Jan
Published: March 2009

The axial density profile is an important characteristic of the CFB riser and a key parameter in the CFB design. A simple, but reliable model is needed to predict the density profiles. Elutriation‐based models treat the dense phase at the bottom of the riser as a dense bubbling bed whereas the dilute phase higher up can be looked upon as the entrainment zone above the dense bed. The elutriation model, as originally presented by Rhodes et al. (1986) and based on Wen et al. (1982) is extensively studied and modified. In spite of the modifications, the use of entrainment models has certain clear limitations due to a wide range of predictions as evident from Table 1. Elutriation rates are calculated based on the hydrodynamic phenomena in the dense bed and a fitting procedure for the entrainment decay constant (σ) was performed.
Fluidization regimes in two‐ and three‐phase fluidized beds: Comparison between measurement techniques
Authors: Barghi Shazad , Briens Cedric L.
Published: March 2009

Fluidization regimes were studied in liquid‐solid and gas‐Liquid‐solid fluidized beds. The liquid velocities at which regime transitions occur in liquid‐solid and gas‐liquid‐solid systems were obtained for monosize and multicomponent systems. Minimum fluidization, complete fluidization and complete mixing velocities of particles were obtained from pressure drop measurements, a collision technique or a conductivity method. The collision technique provided accurate complete fluidization and complete mixing velocities by measuring directly the particle motion. The conductivity technique, which is easier to implement, gave similar but less accurate results.
Heat transfer between an isolated bubble and the dense phase in a fluidized bed
Authors: Hartman George , Wu Wenyuan , Chen Zumao , Agarwal Pradeep K.
Published: March 2009

Heat transfer between the bubble and dense phases of a bubbling fluidized bed plays a very important role in the system performance, especially for applications involving solids drying and gas‐phase combustion. However, very few experimental data are available on this subject in the literature. An experimental and modelling investigation on the heat transfer behaviour of isolated bubbles injected into an incipiently fluidized bed is reported in this paper. A new single‐thermocouple technique was developed to measure the heat transfer coefficient. The effects of bed particle type and size, and bubble size on the heat transfer coefficient were examined. The heat transfer coefficient was found to exhibit a maximum as the bubble size increased in the bubble size range investigated. The bed particle size had a comparatively small effect on the heat transfer coefficient. A simple mathematical model was developed which provides good agreement with experimental data.
Enhancement of the overall volumetric oxygen transfer coefficient in a stirred tank bioreactor using ethanol
Authors: Bi Yonghong , Hill Gordon A. , Sumner Robert J.
Published: March 2009

Ethanol was observed to improve the oxygen mass transfer rate into a well‐mixed bioreactor. The effects of impeller speed and ethanol concentration on the oxygen transfer from air to the water phase and on the average bubble diameter in a stirred tank bioreactor are reported and modelled. The results show that the oxygen mass transfer coefficient (kLa) increases from 0.002 to 0.017 s−1 (for distilled water) due to the increase of impeller speed from 135 to 600 rpm. With increasing ethanol concentration from 0 to 8 g/L, the oxygen mass transfer coefficients increase from 0.015 to 0.049 s−1 and from 0.017 to 0.076 s−1, for impeller speeds of 450 and 600 rpm, respectively. The average bubble diameter decreased from 7.0 mm to 1.7 mm in pure distilled water as the impeller speed was increased from 135 to 600 rpm. When ethanol was present in the aqueous phase, the bubble diameter fell from 6.0 mm to 0.6 mm as the impeller speed was similarly increased.
Kinetics of Aqueous‐Phase catalytic dehydration of 2‐Propanol
Authors: Rivard Jean‐Marc , Zhang Qinglin , Chuang Karl T.
Published: March 2009

The aqueous‐phase catalytic dehydration of 2‐propanol was investigated in a batch slurry reactor. Alumina, zeolite 13X, SAPO‐5 and silicalite are all active in the liquid phase dehydration of 2‐propanol at 463 K with silicalite being the most active catalyst. Propylene was found to be the major reaction product, with diisopropyl ether and acetone formed in trace amounts. The reaction kinetics over silicalite was determined at a temperature range of 434 to 463 K and at a concentration range of 4 to 10 mol% 2‐propanol in water. A single site Langmuir‐Hinshelwood‐Hougen‐Watson (LHHW) type mechanism was found to describe the kinetic data well. Water was found to inhibit the dehydration reaction. The activation energy over silicalite was determined to be 226.8 kJ/mol while the heat of adsorption for 2‐propanol and water was –45.5 and –9.6 kJ/mol, respectively.
Operability of a thermally driven magnesium oxide/water chemical heat pump
Authors: Kato Yukitaka , Minakami Atsushi , Li Guangzhe , Yoshizawa Yoshio
Published: March 2009

The operability of a thermally driven chemical heat pump using the magnesium oxide/water reaction system was demonstrated experimentally. The heat pump system, consisting of a packed bed reactor and a water reservoir, was operated thermally with no mechanical work. The thermal output performance of the reactor bed was measured under pressures between SO and 202 kPa. The heat pump was expected to be applicable as a heat storage system for high efficiency energy utilization in cogeneration.
Optimization of a model IV fluidized catalytic cracking unit
Authors: Luus Rein , Woo Stephen S.
Published: March 2009

Maximization of a profit function related to a fluidized catalytic cracking unit model was carried out by Luus‐jaakola optimization procedure. A 7‐dimensional search is carried out on a FCC unit described by 113 nonlinear algebraic equations and 9 differential equations. Despite the low sensitivity and the existence of several local optima, the global optimum was obtained with reasonable amount of computational effort. At the optimum, the profit function is 1% higher than when the air blowers are constrained to operate at their maximum capacity.
Lag phase model for transient growth of pseudomonas putida on phenol
Authors: Tarighian Alireza , Hill Gordon , Lin Yen‐Han
Published: March 2009

The successful design of large‐scale bioreactors requires the ability to predict both steady‐state and dynamic operating conditions. At the same time, mathematical models should not be too complex in order to reduce experimental work required to determine kinetic parameters. A simple model which predicts the behaviour of batch and transient continuous culture operations is presented and experimentally verified. The model is based on two regions of metabolic activity: the lag phase and the active phase. Pseudomonas putida growing on phenol as a substrate in a well‐mixed bioreactor was tested in three modes of operation: batch, continuous start‐up and continuous step‐change. The model is demonstrated to predict all the qualitative aspects of the dynamic phases of growth and is quantitatively accurate.
Rate equations for the fischer‐tropsch reaction on a promoted iron catalyst
Authors: Rahmati Montazer , Mehdi Mohammad , Bargah‐Soleimani Mehdi
Published: March 2009

Intrinsic rates for the Fischer‐Tropsch synthesis reaction over a promoted iron catalyst fabricated at the Research Institute of the Petroleum Industry (RIPI) have been obtained in the temperature range of 290°C to 310°C, pressure range of 1500 to 2300 kPa, molar hydrogen to carbon monoxide ratio of 0.76 to 1.82, and a space velocity of 3300 h−1 under conditions of constant catalyst activity. To this end, the initial reaction rates have been measured at constant temperature (±1°C) in the absence of diffusion limitations, and power‐law equations have been fitted in terms of the hydrogen and carbon monoxide partial pressures for the reaction rates.
Pseudoischemic Electrocardiogram in Myasthenia Gravis with Thymoma: Reversibility After Thymectomy
Authors: Chiavistelli Patrizio , Cei Marco , Carmignani Giovanni , Bartolomei Carlo , Mumoli Nicola
Published: March 2009

Abnormal ST T‐wave changes can be found at presentation in various noncoronary disorders; misinterpretation of these patterns as ischemic heart disease can lead to erroneous diagnosis and treatment. Here we present a case of myasthenia gravis (MG) with thymoma, in which the resting electrocardiogram (ECG) led to a misleading diagnosis of myocardial ischemia. After thymectomy, the ECG resumed a normal pattern. Myasthenia gravis is not usually considered in the differential diagnosis of conditions associated with an abnormal ECG. The combination of dysphagia, dyspnoea, ECG changes, and creatine kinase (CK) elevations may easily bring to mind an erroneous and possibly deleterious diagnosis of myocardial ischemia. Copyright © 2009 Wiley Periodicals, Inc.
Higher arterial stiffness, greater peripheral vascular resistance and lower blood flow in lower‐leg arteries are associated with long‐term hyperglycaemia in type 2 diabetic patients with normal ankle‐brachial index
Authors: Suzuki Eiji , Yoshimura Toru , Omura Yasushi , Sakaguchi Masayoshi , Nishio Yoshihiko , Maegawa Hiroshi , Hisatomi Akitaka , Fujimoto Kazuma , Takeda Jun , Kashiwagi Atsunori
Published: March 2009

Background

Higher arterial stiffness and greater peripheral vascular resistance reduce blood flow in lower‐leg arteries and contribute to the development of ischaemic limb in diabetic patients even without peripheral artery occlusive disease. The aim of this study was to clarify whether these vascular parameters are associated with long‐term hyperglycaemia in diabetic patients.

Methods

We examined 45 type 2 diabetic patients and 38 age‐matched nondiabetic subjects without peripheral artery occlusive disease assessed by ankle‐brachial index consecutively admitted to our hospital, and followed them over a 3‐year period (3.7 ± 0.7 years) with no vasodilative medication. Blood flow and resistive index, a measure of peripheral vascular resistance, at the popliteal artery were evaluated using gated two‐dimensional cine‐mode phase‐contrast magnetic resonance imaging. Brachial‐ankle pulse wave velocity was measured to assess arterial stiffness.

Results

At baseline, consistent with our previous report, diabetic patients showed higher brachial‐ankle pulse wave velocity (p < 0.0001) and resistive index (p < 0.0001) and lower flow volume (p = 0.0044) than those of nondiabetic subjects. Stepwise multiple regression analysis revealed that duration of diabetes, mean HbA1c during the study, use of renin‐angiotensin system inhibitors and change per year in resistive index were identified as significant independent variables predicting change per year in blood flow (r2 = 0.733, p < 0.0001) in diabetic patients. Mean HbA1c during the study was positively correlated with changes per year in brachial‐ankle pulse wave velocity (p = 0.00007) and resistive index (p = 0.0014) and was negatively correlated with that in blood flow (p < 0.0001) in diabetic patients.

Conclusions

Long‐term hyperglycaemia is a major cause of impaired peripheral circulation in lower‐leg arteries in diabetic patients without peripheral artery occlusive disease. Copyright © 2009 John Wiley & Sons, Ltd.
Working map of the lampbrush chromosomes of Xenopus tropicalis: A new tool for cytogenetic analyses
Authors: Penrad‐Mobayed May , El Jamil Anwar , Kanhoush Rasha , Perrin Caroline
Published: March 2009

The amphibian Xenopus tropicalis, whose genome has been recently sequenced, has become an important model organism for vertebrate developmental genetics. The development of cytogenetic tools in this new model organism should contribute to an understanding of the organization of the amphibian genome and the mapping of a variety of loci of interest. In this respect, oocyte lampbrush chromosomes are particularly useful for the localization of genomic sequences expressed during oogenesis. We have constructed a working map of X. tropicalis lampbrush chromosomes, which allows the 10 bivalents of the oocyte karyotype to be readily identified by distinctive combinations of specific landmark structures composed of lateral loops, spheres, and granules. We have also established the patterns of RNA Pol III sites over the chromosomes by immunofluorescence using antibodies directed against two Pol III subunits. Specific staining patterns were found for each chromosome, which constitute a supplementary tool for their identification. Developmental Dynamics 238:1492–1501, 2009. © 2009 Wiley‐Liss, Inc.
Biocatalytic Cascade for the Synthesis of Enantiopure β‐Azidoalcohols and β‐Hydroxynitriles
Authors: Schrittwieser Joerg H. , Lavandera Iván , Seisser Birgit , Mautner Barbara , Kroutil Wolfgang
Published: March 2009

A three‐step, two‐enzyme, one‐pot reaction sequence starting from prochiral α‐chloroketones leading to enantiopure β‐azidoalcohols and β‐hydroxynitriles is described. Asymmetric bioreduction of α‐chloroketones by hydrogen transfer catalysed by an alcohol dehydrogenase (ADH) established the stereogenic centre in the first step to furnish enantiopure chlorohydrin intermediates. Subsequent biocatalysed ring closure to the epoxide and nucleophilic ring opening with azide, N3–, or cyanide, CN–, both catalysed by a nonselective halohydrin dehalogenase (Hhe) proceeded with full retention of configuration to give enantiopure β‐azidoalcohols and β‐hydroxynitriles, respectively. Both enantiomers of various optically pure β‐azidoalcohols and β‐hydroxynitriles were synthesised. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Chemiluminescent PEG‐PCL micelles for imaging hydrogen peroxide
Authors: Dasari Madhuri , Lee Dongwon , Erigala Venkata Reddy , Murthy Niren
Published: March 2009

Hydrogen peroxide is one of the fundamental molecules of biology, regulating key cell signaling pathways and the development of numerous inflammatory diseases. There is therefore great interest in developing contrast agents that can detect hydrogen peroxide in vitro and in vivo. In this report, we present a new contrast agent for imaging hydrogen peroxide, termed the chemiluminescent poly(ethylene glycol)‐b‐poly(ϵ‐caprolactone) (PEG‐PCL) micelles (CPMs), which can detect hydrogen peroxide at nanomolar concentrations and chemiluminesce in the near IR range (676 nm) in the presence of hydrogen peroxide. The CPMs are composed of a PEG‐PCL scaffold and have fluorescent dyes and peroxalate esters in their hydrophobic PCL core. The CPMs image hydrogen peroxide by undergoing a three‐component chemiluminescent reaction involving a peroxalate ester, a fluorescent dye, and hydrogen peroxide. The CPMs also have a stealth PEG corona to enhance their circulation half life. The CPMs should find numerous applications for imaging hydrogen peroxide because of their nanomolar sensitivity, small size, and stealth pegylated surface. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Synthesis and Properties of Homologous Series of Polyallylcarbosilane Dendrimers with Dense Macromolecular Structure
Authors: Tatarinova E. A. , Voronina N. V. , Bystrova A. V. , Buzin M. I. , Muzafarov A. M.
Published: March 2009

Synthesis of the six generations of polyallylcarbosilane dendrimers with tetrafunctional branching center and tetrafunctional base reagent is reported. Obtained dendrimers are compared to carbosilane dendrimers with less dense molecular structure synthesized before. Densification of the dendrimer structure alters some basic dendrimer properties as well as their dependence on generation.
QoS provision in wireless access networks: a routing perspective considering mobility
Authors: Samdanis Konstantinos , Aghvami A. Hamid
Published: March 2009

Future wireless communications are expected to provide mobile users access to the desired service with the appropriate quality at any place. The essential elements for assembling such a vision are mobility, quality of service (QoS) provision and scalability, which are expected to be merged into the design process of wireless access networks. Internet mobility support is currently entering a mature phase in which scalable solutions provide low loss or even seamless handovers in cellular and heterogeneous mobile environments. Wireless and mobile QoS architectures extend the equivalent Internet approaches in order to accommodate the requirements associated with the presence of wireless links and mobility. Nevertheless, none of the popular mobility proposals combined with wireless and mobile QoS architectures encounter QoS in the routing function, leaving the QoS provision underutilized. QoS routing (QoSR) complements existing QoS architectures, enhancing application performance especially in the case of congestion, while providing efficient resource management. However, QoSR was originally designed for fixed IP networks without taking mobility into account. This paper investigates the interaction of QoSR in wireless access networks, identifying key points for the efficient cooperation with mobility and existing QoS architectures. Copyright © 2009 John Wiley & Sons, Ltd.
Evaluation of curing and physical properties of NR/SBR blends using radiation‐grafting copolymer
Authors: Hassan Medhat M. , Abd El‐Megeed Anhar. A. , Maziad Nabila A.
Published: March 2009

The curing characterizations of natural rubber (NR) and styrene butadiene rubber (SBR) lattices and their blends with and without NR‐g‐MA and SBR‐g‐MA were studied by using oscillating disc rheometer methods. The minimum value for torque decreases with increasing NR in the blends and with the incorporation ofNR‐g‐MA and SBR‐g‐MA. The value of maximum torque increases with increasing of SBR in the blend and with the presence of (NR‐g‐MA and SBR‐g‐MA) is decreased. The mechanical properties of the samples were studied. The tensile strengths increased steadily with an increase of NR content in the blend. Thermal characteristics of these latex blends were studied by thermogravimetric analysis. Thermal degradation of these individual lattices and their blends were investigated with special reference to blend ratio and vulcanization techniques. As the SBR content in the blends increased their thermal stability was also found to increase. POLYM. COMPOS., 2009. © 2009 Society of Plastics Engineers
Giant enhancement of material damage associated to electronic excitation during ion irradiation: The case of LiNbO3
Authors: Rivera A. , Olivares J. , García G. , Cabrera J. M. , Agulló‐Rueda F. , Agulló‐López F.
Published: March 2009

The structural damage induced by ion irradiation on dielectric materials and associated device degradation has been, so far, explained on the basis of collisional processes mostly ignoring the electronic excitation. Recent work, focused on lithium niobate, offers conclusive evidence that at high ion energy and moderate mass (A ≥ 15) electronic excitation may induce a giant enhancement over the damage rate due to nuclear collisions. As a consequence the material becomes amorphized at irradiation fluences far below those required for nuclear collisions alone. These results are expected to have a deep impact on many technologies including storage of radioactive waste, radiation‐resistant materials for fusion reactors, lifetime of components and devices in space missions, nano‐patterning in electronics and photonics, and possibly heavy‐ion therapy in medicine. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Inkjet printed, conductive, 25 μm wide silver tracks on unstructured polyimide
Authors: Meier Henning , Löffelmann Ute , Mager Dario , Smith Patrick J. , Korvink Jan G.
Published: March 2009

25 μm wide, conductive silver tracks on untreated and unstructured polyimide have been produced by inkjet printing using standard 10 pL printheads. This was achieved by reducing the droplet size to ∼2 pL by tailoring the waveform and by heating the print cartridge and the substrate to 55 °C. A simple formula was used to predict the track width. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transport characteristics of indium nitride (InN) films grown by plasma assisted molecular beam epitaxy (PAMBE)
Authors: Knübel Andreas , Aidam Rolf , Cimalla Volker , Kirste Lutz , Baeumler Martina , Leancu Crenguta‐Columbina , Lebedev Vadim , Wallauer Jan , Walther Markus , Wagner Joachim
Published: March 2009

We report on the PAMBE‐growth of high‐quality InN layers with In polarity and on the influence of growth parameters such as Indium‐to‐nitrogen flux ratio as well as substrate temperature on the electronic transport characteristics of these layers. The flux ratio was changed between 0.94 to 1.18 near stoichiometric conditions and the growth temperature was varied between 400 and 485 °C as measured by calibrated pyrometer temperature. The InN films were grown on metal‐organic vapour deposition (MOCVD) GaN templates 3″ in diameter with InN layer thicknesses of 700 nm as determined by spectroscopic ellipsometry (SE). Under In‐rich and near stoichiometric growth conditions a minimum surface root mean square roughness of 0.6 nm was achieved. High resolution X‐ray diffraction show purely hexagonal phase growth and no evidence for the presence of cubic inclusions. InN layers grown under optimized growth conditions exhibit a narrow (FWHM 20 meV) near band edge low temperature photoluminescence (PL) spectrum with a PL peak energy of 0.67 eV, indicating an InN band gap energy of ≈ 0.7 eV, consistent with the dielectric function spectrum derived from SE measurements. Room temperature van‐der‐Pauw Hall measurements reveal high electron mobilities up to 1910 cm2/Vs with mean bulk electron concentrations as low as 5 x 1017 /cm3. Furthermore, efficient surface emission of THz radiation has been demonstrated. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Clique percolation
Authors: Bollobás Béla , Riordan Oliver
Published: March 2009

Derényi, Palla and Vicsek introduced the following dependent percolation model, in the context of finding communities in networks. Starting with a random graph Ggenerated by some rule, form an auxiliary graph G′ whose vertices are the k‐cliques of G, in which two vertices are joined if the corresponding cliques share k – 1 vertices. They considered in particular the case where G = G(n,p), and found heuristically the threshold function p = p(n) above which a giant component appears in G′. Here we give a rigorous proof of this result, as well as many extensions. The model turns out to be very interesting due to the essential global dependence present in G′. © 2009 Wiley Periodicals, Inc. Random Struct. Alg., 2009
Smart Pectin‐based Superabsorbent Hydrogel as a Matrix for Ibuprofen as an Oral Non‐steroidal Anti‐inflammatory Drug Delivery
Authors: Pourjavadi Ali , Barzegar Shahram
Published: March 2009

The purpose of this study was to produce an intelligent superabsorbent polymer (SAP) to be used as a pH sensitive matrix for the controlled delivery of drugs. Novel types of highly swelling SAPs were prepared by grafting crosslinked acrylic acid‐co‐acrylamide (AA‐co‐AAm) chains onto pectin by free‐radical polymerization. The superabsorbent formation was confirmed by Fourier transform infrared spectroscopic (FT‐IR) and scanning electron microscopy (SEM). The controlled release behavior of ibuprofen (IBU) from the superabsorbent polymer was investigated. SAP structural‐property relationships that affect its controlled release behavior were determined. Analysis of the results indicated that it is possible to optimize ibuprofen (IBU) controlled release by adjusting the SAP composition and the crosslinking degree of the copolymer. The results revealed that the release profiles of IBU from the superabsorbent polymer were slow (lower than 2%) in simulated gastric fluid (SGF, pH 1.2) over 3 h, but nearly all of the initial drug content (more than 84%) was released in simulated intestinal fluid (SIF, pH 7.4) within 85 h after changing media. Overall the results demonstrated that biodegradable superabsorbents could successfully deliver a drug to the intestine without losing the drug in the stomach, and could be potential candidates as an orally administrated drug delivery system.
A bandwidth‐efficient cooperative relaying scheme with hard interference cancellation and iterative decoding
Authors: Van Khuong Ho , Le‐Ngoc Tho
Published: March 2009

This paper considers a coded cooperative relaying scheme in which all successfully decoded signals from multiple sources are simultaneously forwarded by a multi‐antenna relay to a common multi‐antenna destination to increase bandwidth efficiency. Iterative decoding with hard interference cancellation is used at destination to recover user information. By using orthogonal transmission from sources to avoid their mutual interference, the multi‐antenna relay offers receive space diversity that greatly enhances the decoding performance at the relay. This makes the source‐relay transmission more robust, less sensitive to the source‐relay link SNR, and hence increases the contribution of the relay in cooperative transmission. Simulation results show that the proposed scheme significantly outperforms direct transmission under the same transmit power and bandwidth efficiency. Copyright © 2009 John Wiley & Sons, Ltd.
Separation of Extracellular Esterases from Pellet Cultures of the Basidiomycete Pleurotus sapidus by Foam Fractionation
Authors: Linke Diana , Nimtz Manfred , Berger Ralf G. , Zorn Holger
Published: March 2009

Two extracellular esterases were produced in submerged cultures of the basidiomycete Pleurotus sapidus. A foam fractionation device was designed and employed for the isolation of the esterolytic enzymes. The recovery of enzyme activity in the liquefied foam strongly depended on the superficial gas velocity. High purification and enrichment factors (Ea = 62.0, P = 15.5) were achieved using nitrogen at 1.87 cm min−1 within 100 min. Increasing the superficial gas velocity to 2.49 cm min−1 improved the recovery of total esterase activity in the foam to >95% at the expense of reduced enrichment and purification factors. Differences in their physicochemical characteristics resulted in differing foaming properties of the two esterases secreted by P. sapidus. By variation of the pH value of the culture medium and addition of Triton X‐100, both esterases were successively and quantitatively transferred into the foam in a two‐step fractionation process.
Validation of the Hypomania Checklist (HCL‐32) in a nonclinical sample of German adolescents
Authors: Holtmann Martin , Pörtner Franca , Duketis Eftichia , Flechtner Hans‐Henning , Angst Jules , Lehmkuhl Gerd
Published: March 2009

We tested the psychometric properties of the Hypomania Checklist (HCL‐32) in a sample of nonclinical adolescents, examined the association with current psychopathology, and tested if “hypomanic” adolescents differ from other participants regarding HCL‐scores and psychopathology. A total of 294 students completed the HCL‐32 and the SDQ, a screening for psychopathology. In adolescence, the internal structure of hypomania seems to be represented by a triple structure. The first factor “active‐elated” is an indicator of symptoms related to energy and activity. The adult factor “irritable‐risk taking” is better reflected by two separate factors (“disinhibited/stimulation‐seeking” and “irritable‐erratic”). These factors were associated with externalizing problems. “Hypomanic” adolescents showed higher HCL total and disinhibited/stimulation‐seeking scores and reported more conduct problems than “non‐hypomanic” youngsters. The internal structure of the HCL in adolescents mirrors the association of juvenile bipolarity with substance use and symptoms of ADHD and conduct disorder and presents preliminary evidence for its validity.
Functional cloning of genes that suppress oxidative stress‐induced cell death: TCTP prevents hydrogen peroxide‐induced cell death
Authors: Nagano-Ito Michiyo , Banba Aoi , Ichikawa Shinichi
Published: March 2009

We used retroviral‐mediated expression cloning to identify cDNAs that inhibit cell death induced by oxidative stress. To isolate the genes, we introduced a murine embryonic retroviral cDNA library into NIH/3T3 cells, and selected for cells resistant to hydrogen peroxide. The surviving cells were cloned, and the integrated cDNAs were rescued by polymerase chain reaction. Several of the isolated cDNAs are known to be involved in modulating the redox state of cells. Other cDNAs encode proteins known to suppress apoptosis caused by reasons other than oxidative stress. These included polyadenylate‐binding protein, cytosolic 1 (Pabpc1) and translationally controlled tumor protein (TCTP).
Expectant management of incomplete abortion in the first trimester
Authors: Pauleta Joana R. , Clode Nuno , Graça Luís M
Published: March 2009

Objective

To evaluate the effectiveness and acceptability of expectant management of induced and spontaneous first trimester incomplete abortion.

Methods

A prospective observational trial, conducted between June 2006 and November 2007, of 2 groups of patients diagnosed with an incomplete abortion: 66 patients who had received misoprostol for an induced abortion (group 1) and 30 patients who had had a spontaneous abortion (group 2). Transvaginal ultrasound was performed weekly. The success rate (complete abortion without surgery), time to resolution, duration of bleeding and pelvic pain, rate of infection, number of unscheduled hospital visits, and level of satisfaction with expectant management were recorded.

Results

The incidence of complete abortion was 86.4% and 82.1% in groups 1 and 2 respectively at day 14 after diagnosis, and 100% in both groups at day 30 (two group 2 patients underwent curettage and were excluded from the analysis). Both groups reported 100% satisfaction with expectant management, although over 90% of the women reported feeling anxious.

Conclusion

Expectant management for incomplete abortion in the first trimester after use of misoprostol or after spontaneous abortion may be practical and feasible, although it may increase anxiety associated with the impending abortion.
Injection laryngoplasty with calcium phosphate cement
Authors: Shiotani Akihiro , Okubo Keisuke , Saito Koichiro , Fujimine Takekatsu , Tomifuji Masayuki , Ikeda Asako , Araki Koji , Momoshima Suketaka
Published: March 2009

Objective

To assess the feasibility of injection laryngoplasty with calcium phosphate cement (CPC), which is an injectable paste, self‐hardening, and which recrystallizes to calcium hydroxylapatite after injection.

Study Design

A case series with planned data collection.

Methods

Fifty‐six patients with unilateral vocal fold paralysis, who received injection laryngoplasty with CPC between August 2003 and August 2007 with a minimum follow‐up period of six months, were enrolled in this study. Volumetric and migration analysis for injected CPC were performed using CT after surgery. Vocal function was also assessed by GRBAS subjective voice assessment scale and maximum phonation time (MPT), acoustic analysis including period perturbation quotient (PPQ), amplitude perturbation period (APQ), and noise‐to‐harmonics ratio (NHR).

Results

No remarkable migration or absorption of injected CPC was observed on CT up to two years after surgery. The average remaining volume of CPC was 87.8% ± 5.3% two years after injection compared to immediately after injection. Significant improvements in GRBAS scales, MPT, PPQ, APQ, and NHR were observed postoperatively. No adverse effects were observed.

Conclusions

Our clinical experience revealed that CPC was safe, nonabsorbable, and effective. Injection laryngoplasty with CPC may be a useful option in the treatment of glottic insufficiency.
Identification of Conserved Regulatory Elements in Mammalian Promoter Regions: A Case Study Using the PCK1 Promoter
Authors: Liu George E. , Weirauch Matthew T. , Van Tassell Curtis P. , Li Robert W. , Sonstegard Tad S. , Matukumalli Lakshmi K. , Connor Erin E. , Hanson Richard W. , Yang Jianqi
Published: March 2009

A systematic phylogenetic footprinting approach was performed to identify conserved transcription factor binding sites (TFBSs) in mammalian promoter regions using human, mouse and rat sequence alignments. We found that the score distributions of most binding site models did not follow the Gaussian distribution required by many statistical methods. Therefore, we performed an empirical test to establish the optimal threshold for each model. We gauged our computational predictions by comparing with previously known TFBSs in the PCK1 gene promoter of the cytosolic isoform of phosphoenolpyruvate carboxykinase, and achieved a sensitivity of 75% and a specificity of approximately 32%. Almost all known sites overlapped with predicted sites, and several new putative TFBSs were also identified. We validated a predicted SP1 binding site in the control of PCK1 transcription using gel shift and reporter assays. Finally, we applied our computational approach to the prediction of putative TFBSs within the promoter regions of all available RefSeq genes. Our full set of TFBS predictions is freely available at http://bfgl.anri.barc.usda.gov/tfbsConsSites.
Identification of Semaphorin 5A Interacting Protein by Applying Apriori Knowledge and Peptide Complementarity Related to Protein Evolution and Structure
Authors: Sadanandam Anguraj , Varney Michelle L. , Singh Rakesh K.
Published: March 2009

In the post-genomic era, various computational methods that predict protein-protein interactions at the genome level are available; however, each method has its own advantages and disadvantages, resulting in false predictions. Here we developed a unique integrated approach to identify interacting partner(s) of Semaphorin 5A (SEMA5A), beginning with seven proteins sharing similar ligand interacting residues as putative binding partners. The methods include Dwyer and Root-Bernstein/Dillon theories of protein evolution, hydropathic complementarity of protein structure, pattern of protein functions among molecules, information on domain-domain interactions, co-expression of genes and protein evolution. Among the set of seven proteins selected as putative SEMA5A interacting partners, we found the functions of Plexin B3 and Neuropilin-2 to be associated with SEMA5A. We modeled the semaphorin domain structure of Plexin B3 and found that it shares similarity with SEMA5A. Moreover, a virtual expression database search and RT-PCR analysis showed co-expression of SEMA5A and Plexin B3 and these proteins were found to have co-evolved. In addition, we confirmed the interaction of SEMA5A with Plexin B3 in co-immunoprecipitation studies. Overall, these studies demonstrate that an integrated method of prediction can be used at the genome level for discovering many unknown protein binding partners with known ligand binding domains.
Cash Crops and Freedom: Export Agriculture and the Decline of Slavery in Colonial West Africa
Authors: Austin Gareth
Published: March 2009

This article argues that the greatest economic and social transformations of the early colonial period in West Africa, the “cash-crop revolution”, and “the slow death of slavery” and debt bondage, had stronger and more varied causal connections than previously realized. The economic circumstances of late nineteenth and early twentieth-century West Africa delayed and diluted abolitionist measures. Indeed, the coercion of labour, through the exercise of property rights in people, contributed to the speed with which the cash-crop economies developed. Conversely, however, the scale and composition of cash-crop expansion did much to determine that the slave trade and pawning would be replaced by a consensual labour market. They also shaped the possibilities for peasant versus larger-scale organization of production, and the distribution of income by gender and between communities.
Variation in the Chemical Composition of the Swede
Authors: Collins S. H.
Published: March 2009

That swedes are better feeding materials under some conditions than under others is more or less generally recognised; the suggestion of controlling these conditions is perhaps not new, but little of practical importance has been achieved in this direction. About five years ago the subject was considered at the Durham College of Science (now Armstrong College), Newcastle-upon-Tyne, and experiments were started which have been repeated and added to every season. The object of these investigations was to form a list of the different varieties of swedes in order of merit. Incidentally other points of interest have arisen, and are dealt with in the following pages. The results of these experiments have been published each year in the Annual Report of the Agricultural Department of the College, but a review of the work done seems of sufficient general importance to prove interesting to a larger circle of readers.
British Ticks
Authors: Wheler Edward Galton
Published: March 2009

The Ixodidae have received so little consideration at the hands of British naturalists that there does not exist amongst our literature any classification of the family having pretension to accuracy or completeness. This may be sufficient to account for the fact that in 1900 when inviting correspondence through the columns of Science-Gossip, I did not receive any reply from a fellow-countryman who had made a serious attempt to study the British ticks, though I have been favoured with much kindly assistance from correspondents who had turned their attention to foreign species.
Mendelian Heredity in Cotton
Authors: Fletcher F.
Published: March 2009

In Volume II. Part 2 of this Journal there appeared a note by W. L. Balls on the above subject, in which he states that “long lint is completely dominant over short.” This dominance, the present writer in India has found to occur in the case of crosses between many very different varieties. The question is not however so simple as it would appear to be from Mr Ball's statement “that the breeding of pure types suitable to the needs of the manufacturer and the cultivator will possibly prove a little difficult”; for though length of staple is on the whole dominant we often get seeds that carry both long and short cotton.
The Ammonia in Soils
Authors: Russell Edward John
Published: March 2009

It has long been recognised that the amount of ammonia in soils cannot be determined by distillation with a solution of caustic soda or potash since these strong alkalis slowly decompose the complex nitrogenous matter and evolve a coutinuous stream of ammonia. Boussingault showed more than fifty years ago how this difficulty could be obviated. By using magnesia in place of soda or potash the decomposition of such substances as urea, asparagin, and albumin was not great even on long boiling, but when the distillation was carried out under reduced pressure at 38°—40° there was no decomposition at all. Ammonium salts, on the other hand, were completely broken up in these circumstances. He used this low pressure method in his researches on the ammonia content of urine, but does not appear to have applied it to soils. Sufficiently accurate results could, he considered, be obtained by distillation at 100°, and this method was for many years generally adopted. It gave results varying according to the nature of the soil from 10 to 100 parts of nitrogen per million (·001 to ·01 per cent.), which may still be found quoted in some of the agricultural text books.
On the Quantity of Ammonia and Nitric Acid in the Rain-water collected at Flahult in Sweden
Authors: von Feilitzen Hjalmar , Lugner Ivar
Published: March 2009

Numerous investigations have been made on the amounts of combined nitrogen in rain and snow in different parts of the world during the last 60 years.
Losses in making and storing Farmyard Manure
Authors: Wood T. B.
Published: March 2009

Two pairs of young heifers were fed on a weighed and analysed diet, and their dung was sampled and analysed both in the fresh and in the rotted states.

It was found that the fresh dung contained about ¾ths of the nitrogen, ⅔rds of the phosphoric acid, and ⅞ths of the potash consumed by the animals in food and litter.

The dung made by the cake-fed animals was found to be more readily fermentable, and consequently more liable to loss during storage, than that made by the animals fed on roots and hay only.

The loss was found to fall chiefly on the ammoniacal nitrogen in which the cake-made dung is comparatively very rich.

Taking as a base-line the amounts of nitrogen and phosphoric acid in the dung of the animals fed on roots and hay only, it was found that the fresh dung of the cake-fed animals contained 82 per cent, of the nitrogen, and 70 per cent, of the phosphoric acid, of the cake they had consumed.

So great however was the loss of ammoniacal nitrogen from the cake-made dung, that after 6 months' storage under cover in the solid undisturbed state in which it was left in the boxes by the animals, only 37 per cent, of the nitrogen of the cake still remained in the rotted dung.

Dung is not usually kept so long as this, nor through such a hot time of the year, so that the average loss will probably be less than that found in the experiment, and ½ the nitrogen of purchased foods may very well be the average amount recovered in the dung.

The experiment shews however that, without any very flagrant mismanagement, the proportion recovered may fall considerably below ½, especially if the dung suffers further loss while lying on the surface of the land in dry weather.
South African Cereal Rusts, with Observations on the Problem of Breeding Rust-Resistant Wheats.
Authors: Pole Evans I. B.
Published: March 2009

History has little of note to relate regarding cereal rusts in South Africa. G. W. Thompson (1) in his Travels and Adventures in South Africa informs us that the wheat crops during 1708—1710 were severely attacked by rust. Theal (2) nevertheless maintains that rust in wheat was not known in the country before the year 1727, when the epidemic was so bad that the crops were almost a complete failure, although he states that rust in rye had been known before 1727. The year 1820, however, is reported as one notorious for the severity of the rust attack.