bluuebunny/crossref_metadata_2025_split huggingface dataset:
Advances in diagnosis and treatment in patients with pulmonary arterial hypertension
Authors: Park Myung H. 
Published: January 2008

AbstractPulmonary arterial hypertension (PAH) is a progressive disease marked by vasoconstriction and vascular remodeling within pulmonary arteries leading to right heart failure and death. Significant advances in understanding the pathobiology of the disease have identified three key pathways involved in progression of this disease, which are the endothelin pathway, the prostacyclin pathway, and the nitric oxide/cyclic guanosine monophosphate pathway. Echocardiogram is the best screening tool to obtain an estimation of the pulmonary artery systolic pressure but right heart catheterization remains the standard by which the diagnosis is made. There are currently six FDA approved therapies for PAH. The mechanistic rationale, evidence behind their use and side effect considerations in utilizing these therapies in PAH patients will be the focus of this review. © 2008 Wiley‐Liss, Inc.
Cutting balloon angioplasty for resistant venous stenoses of dialysis access: Immediate and patency results
Authors: Wu Chih‐Cheng , Wen Szu‐Chi 
Published: January 2008

AbstractObjectives:To evaluate the technical success, safety and patency of cutting balloon angioplasty for the treatment of resistant dialysis access stenoses.Background:Cutting balloon angioplasty has been proposed to be useful in treating resistant dialysis access stenoses. However, they are based on experience with very limited cases and formal patency data is insufficient.Methods:The author retrospectively reviewed 896 percutaneous transluminal angioplasty (PTA) procedures for the treatment of dysfunctional or thrombotic dialysis access. Thirty‐seven of 623 patients with native fistulas and 23 of 273 patients with synthetic grafts had residual stenoses of more than 30% after conventional PTA at an inflation pressure of 24 atm for 60 sec. In these 60 patients, additional cutting balloon PTA was performed.Results:The overall technical success rate was 96.7% and clinical success rate was 98.3%. Only one patient experienced mild local extravasation. The postintervention primary patency rates for native fistula group (N = 37) were 100%, 86.4%, and 67.5% at 1‐month, 3‐month, and 6‐month; the postintervention primary patency rates for synthetic graft group (N = 23) were 87.0%, 60.9%, and 34.2% at 1‐month, 3‐month, and 6‐month respectively.Conclusions:For resistant venous stenoses of dialysis access, cutting balloon PTA is effective, safe, and seems to provide comparative primary patency as suggested by guidelines. © 2008 Wiley‐Liss, Inc.
Rapid Prediction of CO2 Solubility in Aqueous Solutions of DEA and MDEA
Authors: Bahadori A. , Vuthaluru H. B. , Mokhatab S. 
Published: January 2008

AbstractIn the present work, a simple‐to‐use correlation is developed to predict the solubility of CO2 in aqueous solutions of DEA and MDEA as a function of the reduced partial pressure and temperature. Using the interaction parameters generated, the model is applied to correlate the CO2 loading in different amine solutions. The results from the proposed correlation have been compared with the reported experimental data and it was found that there is a good agreement between the observed data and the model predictions over a wide range of operating conditions in aqueous solutions of both diethanolamine (DEA) and methyldiethanolamine (MDEA).
Scaling Up of the Geometrically Similar Unbaffled Circular Tank Surface Aerators
Authors: Rao A. R. K. , Kumar B. 
Published: January 2008

AbstractThe present investigation is concerned with the development of scale‐up equations for the oxygen transfer coefficient, k, and the power number, PO, for unbaffled circular tank surface aerators under geometrically similar conditions, with the purpose of designing energy efficient aerators. It has been found for the present aerators that k and PO are uniquely related to a parameter, X, governing the theoretical power per unit volume and which is defined as Fr4/3Re1/3, where Fr and Re are the impellers' Froude and Reynolds numbers, respectively. Empirical correlations between k and X, as well as PO with X are developed for the range of experiments conducted. Based on such experimental results, procedures to design energy efficient aeration systems have been demonstrated and it was found that smaller sized aerators are more energy efficient and economical when compared to bigger sized tanks, while aerating the same volume of water, by maintaining the same input power to the tanks irrespective of their size. It has been also demonstrated that substantial amounts of energy can be saved if the aeration tanks run at higher input power.
Three‐Dimensional Numerical Simulation of Dense Pneumatic Conveying of Pulverized Coal in a Vertical Pipe at High Pressure
Authors: Pu W. , Zhao C. , Xiong Y. , Liang C. , Chen X. , Lu P. , Fan C. 
Published: January 2008

AbstractA two‐fluid model based on the kinetic theory of granular flow was used to study three‐dimensional steady state flow behavior of dense phase pneumatic conveying of pulverized coal in a vertical pipe, where the average solid concentration ranges from 11 % to 30 %, and the transport pressure ranges from 2.6 Mpa to 3.3 Mpa. Since the solid concentration is rather high, a k–ϵ–kp–ϵp model which considers the turbulence interaction between the gas and particle phase, was incorporated into the two‐fluid model. The simulation results including profiles of gas and particle phase axial velocity, profiles of solid concentration, profiles of the turbulence intensity of the particle phase, as well as the value of the pressure gradient were reported. Then, the influences of solid concentration and transport pressure on the flow behaviors were discussed. The experiment was also carried out to validate the accuracy of the simulation results which showed that the predictions of pressure gradient were in good agreement with the experimental data. Simulation results indicate that the location of maximal solid concentration deviates from the pipe center and the deviation becomes more obvious with the solid concentration increasing, which is analogous to the phenomenon in the liquid/solid flow. Besides, pressure gradient declines as the transport pressure decreases, which is validated by experiment described in the paper. Moreover, the analysis indicates that it is necessary to consider the turbulence of particles for the simulation of dense phase pneumatic conveying at high pressure.
Mixing of Jets in Cross Flow after Double Rows of Radial Injections
Authors: Nirmolo A. , Woche H. , Specht E. 
Published: January 2008

AbstractMultiple rows of jets injected into a cross flow with diameters of 0.3 to 3 m were studied experimentally and numerically. The measured values were in good agreement with CFD calculations. The optimum mixing for a single row was obtained at a normalized momentum flux ratio (J/n2) of 0.3 with a penetration depth (h/R) of 0.6, which is in accordance with previous studies. This condition is valid for all numbers of nozzles. However, increasing the number of nozzles will also improve the mixing quality. Double rows with a staggered arrangement always give a worse mixing quality, compared to a single row. Double rows with an inline arrangement will improve the mixing quality only if the injected volumetric flows produce over‐ and under‐penetrated jets for a $ {\dot V}_{\rm jo1} $/$ {\dot V}_{\rm jo2} $ ratio of 3/1 or 1/3. For operation under ever changing conditions a single row with J/n2 > 0.3 and n ≥ 24 is recommended.
Ionic Modifiers in Phase Transition Extraction
Authors: Castro Arce J. , Strozyk M. , Bart H.‐J. 
Published: January 2008

AbstractThe influence of the addition of NaCl on the temperature‐induced phase separation of 3‐methoxypropionitrile and water was investigated experimentally and theoretically. Experiments performed under direct microscopic observation revealed an enhanced domain growth speed and an improved clarifying behavior. It was found that the relevant physical properties changed dramatically with the addition of NaCl, which induced a shift of the equilibrium curve and a change of the operational temperature. Dissipative particle dynamics simulations have also predicted this shift, although electrostatic interactions were not taken into account explicitly in the current study.
CO2 Capture Using CaO Modified with Ethanol/Water Solution during Cyclic Calcination/Carbonation
Authors: Li Y.‐J. , Zhao C.‐S. , Qu C.‐R. , Duan L.‐B. , Li Q.‐Z. , Liang C. 
Published: January 2008

AbstractThe calcium‐based sorbent cyclic calcination/carbonation reaction is an effective technique for capturing CO2 from combustion processes. The CO2 capture capacity for CaO modified with ethanol/water solution was investigated over long‐term calcination/carbonation cycles. In addition, the SEM micrographs and pore structure for the calcined sorbents were analyzed. The carbonation conversion for CaO modified with ethanol/water solution is greater than that for CaO hydrated with distilled water and is much higher than that for calcined limestone. Modified CaO achieves the highest conversion for carbonation at the range of 650–700 °C. Higher values of ethanol concentration in solution result in higher carbonation conversion for modified CaO, and lead to better anti‐sintering performance. After calcination, the specific surface area and pore volume for modified CaO are higher than those for hydrated CaO, and are much greater than those for calcined limestone. The ethanol molecule enhances H2O molecule affinity and penetrability to CaO in the hydration reaction so that the pores in CaO modified are obviously expanded after calcination. CaO modified with ethanol/water solution can act as a new and promising type of calcium‐based regenerable CO2 sorbent for industrial applications.
Fuzzy Optimization of Extractive Fermentation Processes Including Cell Recycle for Lactic Acid Production
Authors: Lin H.‐T. , Wang F.‐S. 
Published: January 2008

AbstractIn this study, a bioprocess optimization problem was considered for a multiple‐stage extractive fermentation, including cell recycling, to produce lactic acid. The aim of the optimization problem is to obtain the maximum overall productivity, conversion and yield simultaneously, so that the optimization problem is formulated as a multi‐objective optimization procedure. The fuzzy goal attainment method was introduced to the multi‐objective optimization problem in order to obtain a trade‐off solution. The approach was also employed to determine the optimal design for two simplified continuous fermentation processes. From the computational results, the overall productivity for the fermentation processes including cell recycling, enabled a higher dilution rate so that the overall productivity was ca. thirteen‐fold higher than that of the continuous fermentation process without cell recycling.
Structural Paradigms in Macropolyhedral Boranes
Authors: Kiani Farooq Ahmad , Hofmann Matthias 
Published: January 2008

AbstractMacropolyhedral borane clusters are concave polyhedra constituting fused convex simple polyhedra. They are formally obtained by condensation of simple polyhedral boranes under elimination of between one and four BH3 or isoelectronic units. The number of eliminated vertexes from simple polyhedra equals the number of shared vertexes in macropolyhedral boranes. For each of the eight classes with general formulae ranging from BnHn−4 to BnHn+10, more than one structure type is possible, differing in the number of shared vertexes and in the types of the two combined cluster fragments. However, only one type of “potential structures” is represented by experimentally known examples and is found to be favored by theoretical calculations. A sophisticated system exists among the favored macropolyhedral borane structures. For each class of macropolyhedral boranes, the number of skeletal electron pairs is directly related to the general formula, the number of shared vertexes and the type of fused cluster fragments. In order to predict the distribution of vertexes among the fused fragments, we propose the concept of preferred fragments. Preferred fragments are those usually present in the thermodynamically most stable structure of a given class of macropolyhedral boranes and are also frequently observed in the experimentally known structures. This allows us to completely predict the cluster framework of the thermodynamically most stable macropolyhedral borane isomers.
A Heteroditopic Fluoroionophoric Platform for Constructing Fluorescent Probes with Large Dynamic Ranges for Zinc Ions
Authors: Zhang Lu , Clark Ronald J. , Zhu Lei 
Published: January 2008

AbstractA heteroditopic fluoroionophoric platform has been designed for constructing fluorescent probes for zinc ions over large concentration ranges. The responses of the prototype probes3 aand3 bto zinc ions were shown to be consistent with our hypothesis, according to which the modulation of photoinduced electron transfer followed by conformation rigidification or enhanced internal charge transfer of a ditopic ligand upon successive zinc coordination affords a sensitive fluorescence enhancement in one wavelength channel followed by an emission band shift to another wavelength channel. The heteroditopic arylvinyl‐bipy platform established in this study provides a lead structure for constructing fluorescent probes for real‐time live cell imaging of zinc ions over broad dynamic ranges.
Selective Mono‐ and 1,2‐Difunctionalisation of Cyclopentene Derivatives via Mg and Cu Intermediates
Authors: Despotopoulou Christina , Bauer Richard C. , Krasovskiy Arkady , Mayer Peter , Stryker Jeffrey M. , Knochel Paul 
Published: January 2008

AbstractA single Br/Mg exchange of 1,2‐dibromocyclopentene with iPrMgCl⋅ LiCl provides the corresponding β‐bromocyclopentenylmagnesium reagent, which can then be reacted with various electrophiles (yields: 65–82 %). In the presence of a secondary alkylmagnesium halide and Li2CuCl4 (2 mol %), these 2‐bromoalkenylmagnesium compounds undergo bromine substitution and can then further react with electrophiles to give 1,2‐difunctionalised cyclopentenes (63–79 %). The mechanism of this process is discussed.
Modellierungsansätze für die Design‐Optimierung von reaktiven Rektifikationskolonnen
Authors: Barkmann S. , Sand G. , Engell S. 
Published: January 2008

AbstractDieser Beitrag beschäftigt sich mit der Auslegung von komplexen integrierten Prozessen am Beispiel der Reaktivrektifikation. Zur Ermittlung des aus ökonomischer Sicht optimalen Apparatedesigns und Betriebspunkts können Methoden der mathematischen Optimierung eingesetzt werden. Dies führt auf große, gemischt‐ganzzahlige nichtlineare Optimierungsprobleme, die mit verfügbaren kommerziellen Algorithmen auch ohne Vorinformation über die optimale Konfiguration des Apparats oder der Apparateverschaltung gelöst werden können. Der Rechenaufwand hängt dabei stark von der Anzahl der diskreten Variablen ab. Hier werden die allgemeine Methodik vorgestellt und verschiedene Modellierungsansätze für die diskreten Entscheidungsvariablen hinsichtlich des Rechenzeitbedarfs und der Lösungsqualität der Optimierung verglichen.
Filtration zur Partikelabtrennung bei der Wasserreinigung
Authors: Gimbel R. , Nahrstedt A. , Panglisch S. 
Published: January 2008

AbstractSowohl im industriellen als auch kommunalen Bereich ist die Entfernung partikulärer Stoffe aus Wasser eine zentrale Aufgabe. Speziell zur Behandlung stark verdünnter Suspensionen und großer Volumenströme bieten sich hierfür die Tiefenfiltration sowie die Oberflächenfiltration in Form der Membranfiltration an. Die Tiefenfiltration ist seit vielen Jahrzehnten in der Wasserreinigung etabliert und wurde ständig weiterentwickelt. Dagegen ist die Membranfiltration unter Verwendung von Ultra‐ und Mikrofiltrationsmembranen, die i. d. R. als Kapillaren zum Einsatz kommen, ein Verfahren, das erst seit etwa 15 Jahren großtechnisch relevant ist, in dieser Zeitspanne aber ein geradezu exponentielles Wachstum aufweist.
Changes of the Properties in the Upper Layers of Human Skin on Treatment with Models of Different Pharmaceutical Formulations—An Ex vivo ESR Imaging Study
Authors: Moll Klaus‐Peter , Herrmann Werner , Stößer Reinhard , Borchert Hans‐Hubert 
Published: January 2008

AbstractThe noninvasive method of spectral‐spatial electron spin resonance imaging (ESRI) was used to obtain a polarity map of human skin. The spin probes TEMPO, TEMPOL, and CAT‐1, which are considered to act as drug representatives, were applied as reporter molecules. The polarity in skin layers was described by means of the changes of the hyperfine splitting constant Aiso, which itself is a reflection of interactions at a molecular level, and the effect of polarity on the spatial distribution of spin probes in skin samples was studied. Analyses of ESR tomograms of two‐phase systems finalized in a simplified description for the empiric interpretation of values of the isotropic hyperfine coupling constants Aiso of spin probes in different layers of human skin. The simplified statement provides values for the probability of interactions of water molecules with the NO group of spin probes. This allows conclusions concerning the state of hydration of the spin probes in different layers of the skin and introduces the spatial polarity function as additional and valuable information for existing skin models.
Role of the cytokine environment and cytokine receptor expression on the generation of functionally distinct dendritic cells from human monocytes
Authors: Conti Lucia , Cardone Marco , Varano Barbara , Puddu Patrizia , Belardelli Filippo , Gessani Sandra 
Published: January 2008

AbstractMyeloid dendritic cells (DC) and macrophages evolve from a common precursor. However, factors controlling monocyte differentiation toward DC or macrophages are poorly defined. We report that the surface density of the GM‐CSF receptor (GM‐CSFR) α subunit in human peripheral blood monocytes varies among donors. Although no correlation was found between the extent of GM‐CSFR and monocyte differentiation into DC driven by GM‐CSF and IL‐4, GM‐CSFR expression strongly influenced the generation of CD1a+ dendritic‐like cells in the absence of IL‐4. CD1a+ cells generated in the presence of GM‐CSF express CD40, CD80, MHC class I and II, DC‐SIGN, MR, CCR5, and partially retain CD14 expression. Interestingly, they spontaneously induce the expansion of CD4+ and CD8+ allogeneic T lymphocytes producing IFN‐γ, and migrate toward CCL4 and CCL19. Upon stimulation with TLR ligands, they acquire the phenotypic features of mature DC. In contrast, the allostimulatory capacity is not further increased upon LPS activation. However, by blocking LPS‐induced IL‐10, a higher T cell proliferative response and IL‐12 production were observed. Interestingly, IL‐23 secretion was not affected by endogenous IL‐10. These results highlight the importance of GM‐CSFR expression in monocytes for cytokine‐induced DC generation and point to GM‐CSF as a direct player in the generation of functionally distinct DC.
SWAP‐70 regulates mast cell FcϵRI‐mediated signaling and anaphylaxis
Authors: Sivalenka Raja R. , Sinha Manoj , Jessberger Rolf 
Published: January 2008

AbstractMast cells, perhaps best known by their ability to trigger allergic reactions after stimulation through the FcϵRI, express the unusual phosphatidylinositol 3‐kinase (PI3K)‐dependent, Rac‐binding protein SWAP‐70. Here, we show that the IgE‐mediated passive cutaneous and the systemic anaphylactic responses are strongly reduced in SWAP‐70–/– mice. Cultured SWAP‐70–/– immature bone marrow mast cells (BMMC) are also impaired in FcϵRI‐mediated degranulation, which can be restored by expression of exogenous wild‐type SWAP‐70, but less so if a phosphatidylinositol trisphosphate (PIP3) binding mutant is expressed. SWAP‐70 itself supports inositol‐3‐phosphate and PIP3 production, the latter indicating a potential feedback from SWAP‐70 towards PI3K. FcϵRI‐stimulated transcription and release of cytokines is controlled by SWAP‐70. Key FcϵRI signal transduction events like activation of LAT by phosphorylation, activation of Akt/PKB and of p38 MAP kinase are reduced in SWAP‐70–/– BMMC, but ERK is strongly hyperactivated. Some requirements for SWAP‐70 were apparent only under limited‐strength signaling conditions. We suggest that SWAP‐70 defines a new element of efficient mast cell activation upon FcϵRI signaling, important for the control of mast cell‐dependent anaphylaxis.
Synthesis of para‐Amino Benzoic Acid–TiO2 Hybrid Nanostructures of Controlled Functionality by an Aqueous One‐Step Process
Authors: Rahal Raed , Daniele Stéphane , Hubert‐Pfalzgraf Liliane G. , Guyot‐Ferréol Véronique , Tranchant Jean‐François 
Published: January 2008

AbstractIn situ amino acid surface‐modified TiO2 nanoparticle syntheses were performed by a simple one‐pot hydrolysis of heteroleptic titanium alkoxide [Ti(OiPr)3(O2CC6H4NH2)]m in water with NnBu4Br. This process allowed precise control of the surface grafting rate by varying the amount of precursors and provided highly functionalized nanomaterials. Their compositions and microstructures were determined by C, H and N elemental analyses, TGA‐MS, 13C CP‐MAS NMR, XRD, TEM, BET, Raleigh diffusion, FTIR, Raman, XPS and UV/Vis experiments. The results indicated that (i) the aggregation rate increased with an increase in the loading of the organic substrate and (ii) the amino acid is chemisorbed as a carboxylate group onto the TiO2 nanoparticles, which leads to a strong interaction between the amino acid and the TiO2 nanoparticle and good stability of these hybrids. Applications of low‐aggregated nanomaterials were demonstrated as efficient protection additive against UVA + UVB radiations.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Sc3AlN – A New Perovskite
Authors: Höglund Carina , Birch Jens , Beckers Manfred , Alling Björn , Czigány Zsolt , Mücklich Arndt , Hultman Lars 
Published: January 2008

AbstractSc3AlN with perovskite structure has been synthesized as the first ternary phase in the Sc–Al–N system. Magnetron sputter epitaxy at 650 °C was used to grow single‐crystal, stoichiometric Sc3AlN(111) thin films onto MgO(111) substrates with ScN(111) seed layers as shown by elastic recoil detection analysis, X‐ray diffraction, and transmission electron microscopy. The Sc3AlN phase has a lattice parameter of 4.40 Å, which is in good agreement with the theoretically predicted 4.42 Å. Comparisons of total formation energies show that Sc3AlN is thermodynamically stable with respect to all known binary compounds. Sc3AlN(111) films of 1.75 µm thickness exhibit a nanoindentation hardness of 14.2 GPa, an elastic modulus of 249 GPa, and a room‐temperature electrical resistivity of 41.2 µΩ cm. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Tilting of active folds and drainage asymmetry on the Manawatu anticlines, New Zealand: a preliminary investigation
Authors: Clement Alastair J. H. , Brook Martin S. 
Published: January 2008

AbstractThe apparent southward tilting of five anticlines in the Manawatu, North Island, New Zealand, is investigated using two drainage basin analysis techniques: the transverse topographic symmetry factor (T) and the asymmetry factor (AF). The techniques are used to determine whether westward‐flowing trunk streams on the gentle western limbs of five anticlines are migrating southwards across their drainage basins, concomitant with down‐tilting of the fold axes. While results show potential for the techniques to be applied in such a tectonic setting, our findings are inconclusive. This could be due to the incipient nature of the folds (c. 0·5 Ma in age), and it would seem more appropriate to apply the techniques in concert with detailed field analyses of river migration patterns. Copyright © 2008 John Wiley & Sons, Ltd.