bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental and Numerical Study of Interface Crack Propagation in Foam-cored Sandwich Beams
Authors: Berggreen C. , Simonsen B. C. , Borum K. K.
Published: August 2006

This article deals with the prediction of debonding between core and face sheet in foam-cored sandwich structures. It describes the development, validation, and application of a FEM-based numerical model for the prediction of the propagation of debond damage. The structural mechanics is considered to be geometrically nonlinear while the local fracture mechanics problem is assumed to be linear. The presented numerical procedure for the local fracture mechanics is a further development of the crack surface displacement method, here denoted as the crack surface displacement extrapolation method. The considered application example is to tear off one of the face laminates from the sandwich. This configuration can be found in many applications but is considered here to be occurring in a ship structure, particularly at the hard spot where the superstructure meets the deck. Face tearing experiments are carried out for structures with three different core densities, material tests are carried out and finally the face tearing tests are simulated with the developed procedure. It is shown that for low core densities, where the crack propagates in the interface immediately below the face sheet, there is fair agreement between experiments and theory. For cores with higher density, the crack tends to propagate in the laminate itself with extensive fiber bridging leading to rather conservative numerical predictions. However, for structural configurations where LEFM can be applied, the presented procedure is sufficiently robust and accurate to be used in a number of important engineering applications, for example risk-based inspection and repair schemes.
Measurement and Compensation of Spring-back of a Hybrid Composite Beam
Authors: Jung Woo-Kyun , Chu Won-Shik , Ahn Sung-Hoon , Won Myung-Shik
Published: August 2006

Fiber-reinforced composite materials have been advanced in various applications for their excellent mechanical and electromagnetic properties. On their manufacturing processes, however, thermo-curing inherently produces the undesired thermal deformation, so-called spring-back, mainly caused by temperature drop from the process temperature to room temperature. In order to fabricate designed part geometry, the spring-back must be understood especially in hybrid composites consisting of distinct groups of different materials. In this research, the spring-back of a hybrid composite beam is measured by a series of experiments, and is predicted by the classical lamination theory (CLT) and finite element analysis (ANSYS). To confirm the predicted spring-back, {glass fiber/epoxy} + {carbon fiber/epoxy} asymmetric hybrid composites are fabricated under various conditions such as cure cycle, laminate thickness, stacking sequence, and curing sequence. The results from CLT and FEA agree well with the experimental data, but the spring-back cannot be removed completely. To fabricate flat hybrid composite beams, a web-based spring-back compensation service is developed. The CLT-based code allows the user to predict spring-back and to fabricate a mold that compensates spring-back.
Simulation of the Hot-pressing of a Multi-layered Wood Strand Composite
Authors: Lee Jong N. , Kamke Frederick A. , Watson Layne T.
Published: August 2006

A mathematical model of the hot-pressing consolidation process for manufacturing a multi-layered oriented strand composite is developed and tested. Such a process model requires independent physical properties and user-specified structure for each layer of the mat. The model uses two-dimensional (slow variation is assumed in the third dimension) heat- and mass-transfer theory and a viscoelastic compression model. The through-the-thickness (vertical) density profile (VDP) was found to be highly dependent on the initial moisture content gradient, internal mat strand properties, and hydrothermal compressive response of the mat. The VDP predicted by the model showed good agreement with experimental results. The proposed mathematical model thus shows promise as a tool to analyze optimally design-oriented strand composites.
Rapid Composite Tube Manufacture Utilizing the QuickstepTM Process
Authors: Silcock Michael D. , Garschke Claudia , Hall Wayne , Fox Bronwyn L.
Published: August 2006

In this study, a novel method for manufacturing composite tubes utilizing the QuickstepTM process has been developed. Tubes manufactured from `quick-cure' Toray G83C prepreg have demonstrated highly repeatable axial crush behavior with an average specific energy absorption (SEA) of 86 kJ/kg. The cure cycle is optimized by comparing the results from compression, dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC), and porosity testing. The tube lay-up is optimized using compression and porosity test results. The effect of changes in fiber-orientation on SEA is also investigated. Process development has resulted in a robust manufacturing method capable of producing fully cured, high performance composite tubes with a cure cycle of 7 min. This corresponds to a 95% reduction in time compared to an equivalent autoclave cycle.
Organic Rectorite-modified Unsaturated Polyester Resin Composites
Authors: Yuan Li , Ma Xiao-Yan , Liang Guo-Zheng , Yun Huang
Published: August 2006

In this study, rectorite (REC), being a type of layered silicates, has been applied to the polymer to improve its properties. The glass fiber-reinforced polymer-layered silicate clay composites are a new option to modify the properties of the polymer. In the present study, unsaturated polyester resins (UP) are modified by organic rectorite (OREC) to improve the mechanical properties of UP and fiber-reinforced UP (UP/F) composites. The influences of OREC on the gel time, viscosity, and reaction mechanism of UP are discussed. The chemical structures and microstructures of OREC and OREC-modified UP (OREC/UP) are analyzed by using Fourier transform infrared spectrometer (FTIR) and X-ray diffraction (XRD), respectively. The fracture morphologies of OREC/UP and glass fiber-reinforced OREC/UP (OREC/UP/F) composites are observed by using a scanning electron microscope (SEM). The mechanical properties, the resistance to medium, and the ultraviolet aging of OREC/UP and OREC/UP/F composites are investigated. Additionally, the heat distortion temperature of OREC/UP and the hot-air aging of OREC/UP/F composites are also measured. The results indicate that the addition of OREC can increase the gel time and viscosity. The mechanical properties as well as other properties of pure UP and UP/F composites can be improved by adding OREC, and the comprehensive properties of OREC/UP/F composites containing 2wt% OREC are optimal among the prepared ternary composites.
A Phenomenological Mohr—Coulomb Failure Criterion for Composite Laminates under Interlaminar Shear and Compression
Authors: Xiao J.R. , Gillespie J.W.
Published: August 2006

A new phenomenological delamination criterion has been proposed for considering the effects of through-thickness compression based on a modified Mohr—Coulomb friction mechanism. Published experimental results show that through-thickness compressions increase the interlaminar shear (ILS) strength nonlinearly, which requires a nonlinear friction function. The proposed delamination criterion with a nonlinear friction function considers the full extent of the ILS increase observed in available experiments. Excellent agreements have been achieved between predicted and experimental failure envelopes with proper selections of parameters. The present theory is able to predict the shear strength enhancement in the presence of friction and compression more accurately than current methods. The strain rate effect on compression dependent ILS of composite laminates is also addressed qualitatively.
An Accurate Mixed-mode Delamination Failure Criterion for Laminated Fibrous Composites Requiring Limited Experimental Input
Authors: Davidson Barry D. , Zhao Wenming
Published: August 2006

A mixed-mode delamination failure criterion is proposed that may be characterized using test data from only double cantilever beam, end-notched flexure, and single leg bending tests. For validation, a comprehensive literature survey is first performed to obtain toughness versus mode mix data for continuous fiber polymeric matrix composites, and the proposed criterion is then evaluated using those studies where sufficient data are reported. To this end, the criterion is used to obtain an expression for toughness versus mode mixity using only a subset of the experimental data that is presented in any given source. This is done using the toughness data from mode I and mode II tests that are performed, as well as the results from the test with a mode ratio closest to that of the single leg bending test. The failure locus predicted by the new criterion is then compared to the experimentally determined toughnesses over the full range of the experimental data. These results indicate that the proposed criterion is highly accurate for materials spanning a wide range of classifications of fiber reinforced polymeric matrix composites. Further, the accuracy of the proposed criterion is found to be equal to or better than other delamination failure criteria that have been utilized in the past, including those that use a great deal more experimental data for their characterization. It is concluded that the proposed criterion, which can be obtained from only a few simple tests, has predictive accuracy that is similar to that obtained using a failure locus that is fully characterized experimentally. A variety of practical uses of this new criterion are also described.
The extension of the western limb, Bushveld Complex (South Africa), at Cullinan Diamond Mine
Authors: Cawthorn R.G. , McKenna N.
Published: August 2006

Mafic rocks of the Bushveld Complex at the southeastern end of the western limb, intersected in bore core from the Cullinan Diamond Mine, are described. A 260 m thick ultramafic body of orthopyroxene and chromite cumulate rocks, with mg# – 100*Mg/(Mg+Fe) – values from 77 to 84 and 0.25 to 0.5% Cr2O3 in the pyroxene, is considered to have affinity to the Critical Zone. Such an interpretation considerably extends the eastern limit of Critical Zone rocks of the western limb of the Bushveld Complex. The whole-rock composition of the lower, chilled basal contact of this body has 10% MgO and 500 ppm Cr, and is comparable to magmas considered parental to the Bushveld Complex. Due to intrusion of a younger sill, the upper contact is not preserved in the bore core. The cumulate rocks have higher interstitial component, inferred from incompatible trace element abundances (Zr, Ti and K), than normal Critical Zone rocks, interpreted to be a result of more rapid cooling due to proximity to the basal contact. The near-constancy of mg# in the pyroxene in the entire succession suggests that large volumes of magma flowed through this conduit, with only the liquidus phases of orthopyroxene and chromite being precipitated.

Five generations of sills, intruded into the underlying metasedimentary rocks, are identified. The oldest is tholeiitic, and was metamorphosed prior to the emplacement of the Bushveld Complex. The second equates to the magma proposed as being parental to the Bushveld Complex (2060 Ma). The third represents the products of differentiation of that magma. The fourth is syenitic, and related to the Pienaars River Alkaline Complex (1430–1300 Ma). The fifth is tholeiitic (1150 Ma), and cuts the Cullinan kimberlite.
Characteristics of halloysite associated with rectorite from Hubei, China
Authors: Hong H.-L. , Mi J.-X.
Published: August 2006

The mineralogical characteristics of halloysite in rectorite pelite in the Zhongxiang area, Hubei, China, were investigated using X-ray diffraction, scanning electron microscopy and high-resolution transmission electron microscopy methods. The results show that halloysite crystals exhibit euhedral lamellar, tubular or club-like, and needle-like or fibre-like morphologies, indicating that they crystallized from a significantly water-saturated environment. The mineral assemblage of the rectorite pelite is rectorite, halloysite, illite, gypsum, pyrite and rutile, suggesting a weak supergene alteration. Several features related to crystallization of halloysite were noted. Growth of halloysite on rectorite edge surfaces in voids and twins of halloysite on a nanometer scale with composition plane (110) were found in the Zhongxiang rectorite pelite, and, in particular, the tapered ends of tubes suggest that halloysite crystallized from solution. Disaggregation of lamellar halloysite particles into parallel clusters of single tubular halloysite crystals suggests that because of significant [H2O] activity in the environment, halloysite may have been derived from the alteration of rectorite.
The missing sulphur in mattheddleite, sulphur analysis of sulphates, and paragenetic relations at Leadhills, Scotland
Authors: Essene E. J. , Henderson C. E. , Livingstone A.
Published: August 2006

Published electron microprobe analyses of mattheddleite, a lead sulpho-silicate apatite from Leadhills, Scotland, have 9–13% IV site deficiencies. However, galena was used as a standard for S, which suggested that low S resulted from a shift in the S-Kα peak. Wavelength scans with a PET crystal show that the S-Kα peak is shifted down by 0.0026 Å for sulphates relative to sulphides. Quantitative analyses show a ∼30% increase of S in mattheddleite using a celestite standard, which fills the IV site, but with Si > S, on average Pb5S1.2Si1.8O11.7Cl0.6(OH)0.4. Direct analysis of oxygen with the electron microprobe implies that the charge imbalance engendered from the inequality of Si and S is compensated with substitution of a vacancy (□), as in Pb5S1.2Si1.8[O11.7□0.3] [Cl0.6(OH)0.4] or Pb5S1.2Si1.8[O11.7(Cl, OH)0.73]. [Cl,OH)0.7 □0.3]. Calculation of OH as l–C1 suggests the presence of both OH- and Cl-dominant mattheddleite at Leadhills, but direct analysis of H is needed to confirm the dominance of OH in the channel site. Wavelength-dispersive analyses of S in apatite and other sulphates must be undertaken with sulphate standards: use of sulphide standards yields a negative error on the order of 10–20% in the resultant S concentration. Reactions of mattheddleite with other Pb minerals at Leadhills show that their stability depends on fluid composition as well as pressure and temperature. An X-ray map of Cl shows complex zoning between Cl-poor and Cl-rich mattheddleite, recording rapid changes in the fluid chemistry during late-stage hydrothermal processes at Leadhills.
The origin of the hydrous scandium phosphate, kolbeckite, from the Hagendorf-Pleystein pegmatite province, Germany
Authors: Dill H.G. , Weber B. , Füssl M. , Melcher F.
Published: August 2006

The rare hydrous scandium phosphate, kolbeckite, [Sc(PO4).2H2O], has been recognized for the first time from the Hagendorf-Pleystein pegmatite province. The mineral was formed by the alteration of quartz-rich relict cores of pegmatites containing rutile, ilmenite, columbite, pyrochlore, wolframite, monazite and apatite. The alteration process involved acidic meteoric water and was not related to low-temperature hydrothermal fluids. Scandium and phosphorous for the formation of the kolbeckite were provided by the decomposition of the primary oxides and phosphates, respectively. Hydrous Sc phosphates are considered to form only during advanced stages of weathering in Al- and Fe-poor environments. In Al- and Fe-rich environments Sc is scavenged from solution as a trace component of Al- and Fe phosphates. A special type of leucoxene containing Fe, Al and P was formed during the process of formation of kolbeckite. In the absence of phosphate anions, Sc is removed in solution and ‘normal’ leucoxene is formed.
Characterization of fluoro-edenite by μ-Raman and μ-FTIR spectroscopy
Authors: Rinaudo C. , Cairo S. , Gastaldi D. , Gianfagna A. , Mazziotti Tagliani S. , Tosi G. , Conti C.
Published: August 2006

The prismatic variety of fluoro-edenite, a new amphibole found in lavas from Mt Etna in Biancavilla (Catania Province, Sicily, Italy), has been characterized by μ-Raman and μ-FTIR spectroscopy. The wavenumbers at which the bands are detected in the μ-Raman and μ-FTIR spectra are compared with tremolite, asbestos the chemical and crystallographic characteristics of which are very similar to those of fluoro-edenite.
An XRD, SEM and TG study of a uranopilite from Australia
Authors: Frost R.L. , Weier M.L. , Ayoko G.A. , Martens W. , Čejka J.
Published: August 2006

A uranopilite from The South Alligator River, Northern Territory, Australia, has been studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) with EDAX attachment, and thermogravimetry in conjunction with evolved gas mass spectrometry. The XRD shows that the mineral is a pure uranopilite with few if any impurities. The SEM images show that the uranopilite consists of elongated crystals, up to 50μm long and 5 μm wide. Thermogravimetry combined with mass spectrometry shows that dehydration occurs at ∼31°C resulting in the formation of metauranopilite. The first dehydration step over 20–71°C corresponds to a decrease of 5.4 wt.%, equivalent to 6.076 H2O. The second dehydration step, over the temperature range 71 –162.4°C corresponds to a decrease of 4.7 wt.%, equivalent to 5.288 H2O, making a total of 11.364 moles of H2O, close to 12 H2O for uranopilite.

Dehydroxylation takes place over the temperature range 80–160°C. The loss of sulphate occurs at higher temperatures in two steps at 622 and 636°C. A mass loss also occurs at 755°C, accounted for by evolved oxygen.
Structural changes induced by cation ordering in ferrotapiolite
Authors: Zema M. , Tarantino S.C. , Giorgiani A.
Published: August 2006

Structural modifications as a function of the degree of order (Q) in FeTa2O6ferrotapiolite have been characterized by means of single-crystal X-ray diffraction (SC-XRD). A total of 26 datasets covering the range ofQbetween 0.154 and 1 have been obtained by thermal treatments followed by quenching of natural tapiolite crystals. Ordering of Fe2+at theAsites and of Ta5+at theBsites causes a linear increase in thea/clattice constants ratio, as a consequence of a linear decrease of the c dimension and only slight modifications of theaparameter. Calibration ofa/c vs. Qrepresents a very useful tool for a rapid determination of the degree of order of tapiolite samples. Polyhedral volumes of the two octahedral sites vary linearly withQas a consequence of the different ionic radii of the two species. Both the sites remain almost regular at allQvalues but theBsite shows an increasing off-centre displacement of the cation with increasingQ.Observed structure factors of supercell reflections, characterized byl≠ 3n, increase linearly as a function ofQ,thus representing a further tool for a quick evaluation of the degree of order.
Differential kinase requirements in human and mouse Fc-gamma receptor phagocytosis and endocytosis
Authors: Huang Zhen-Yu , Barreda Daniel R , Worth Randall G , Indik Zena K , Kim Moo-Kyung , Chien Paul , Schreiber Alan D
Published: August 2006

Fc gamma receptors (FcγRs) contribute to the internalization of large and small immune complexes through phagocytosis and endocytosis, respectively. The molecular processes underlying these internalization mechanisms differ dramatically and have distinct outcomes in immune clearance and modulation of cell function. However, it is unclear how the same receptors (FcγR) binding to identical ligands (IgG) can elicit such distinct responses. We and others have shown that Syk kinase, Src-related tyrosine kinases (SRTKs) and phosphatidyl inositol 3-kinases (PI3K) play important roles in FcγR phagocytosis. Herein, we demonstrate that these kinases are not required for FcγR endocytosis. Endocytosis of heat-aggregated IgG (HA-IgG) by COS-1 cells stably transfected with FcγRIIA or chimeric FcγRI-γ-γ (EC-TM-CYT) was not significantly altered by PP2, piceatannol, or wortmannin. In contrast, phagocytosis of large opsonized particles (IgG-sensitized sheep erythrocytes, EA) was markedly reduced by these inhibitors. These results were confirmed in primary mouse bone marrow-derived macrophages and freshly isolated human monocytes. Levels of receptor phosphorylation were similar when FcγRIIA was cross-linked using HA-IgG or EA. However, inhibition of FcγR phosphorylation prevented only FcγR phagocytosis. Finally, biochemical analyses of PI3K(p85)-Syk binding indicated that direct interactions between native Syk and PI3K proteins are differentially regulated during FcγR phagocytosis and endocytosis. Overall, our results indicate that FcγR endocytosis and phagocytosis differ dramatically in their requirement for Syk, SRTKs, and PI3K, pointing to striking differences in their signal transduction mechanisms. We propose a competitive inhibition-based model in which PI3K and c-Cbl play contrasting roles in the induction of phagocytosis or endocytosis signaling cascades.
CD69 targeting differentially affects the course of collagen-induced arthritis
Authors: Sancho David , Gómez Manuel , Martinez del Hoyo Gloria , Lamana Amalia , Esplugues Enric , Lauzurica Pilar , Martinez-A Carlos , Sánchez-Madrid Francisco
Published: August 2006

CD69 expression is induced following activation of leukocytes at inflammatory sites and plays a negative regulatory role in the development of collagen-induced arthritis (CIA). To evaluate potential strategies of CD69 targeting in chronic inflammatory diseases, two different anti-CD69 mAbs were generated and their effects on CIA were studied. Administration of the IgG1 anti-CD69 mAb 2.2 to DBA/1 mice with CIA led to an exacerbation of the disease, correlated with down-modulation of CD69 from the cell surface, and reproduced the phenotype of the CD69(−/−) mouse in wild-type animals. In contrast, treatment with the IgG2a anti-CD69 mAb 2.3 was effective in ameliorating CIA when administered in the early or intermediate phases of the disease, causing a decreased production of proinflammatory cytokines in inflammatory foci. Monoclonal antibody 2.3 induces partial depletion of CD69+ cells in vivo. Moreover, adoptive transfer of type-II collagen (CII)-sensitized cells treated with mAb 2.3 to deplete CD69+ cells did not result in arthritis. The attenuation of inflammation correlates with reduced lymphocyte proliferative response in response to CII and with a reduction in the frequency of CII-specific T cells producing IFN-γ. We thus conclude that CD69 targeting by mAbs can either enhance or dampen the immune response.
Liposome-mediated RNA transfection should be used with caution
Authors: Barreau Carine , Dutertre Stéphanie , Paillard Luc , Osborne H. Beverley
Published: August 2006

Liposome-mediated RNA transfection appears to present a number of advantages for studying the metabolism of reporter mRNAs in mammalian cells. This method is also widely used to transfect siRNAs. Here we describe results indicating that reporter mRNAs introduced into HeLa cells by liposomes do not present the expected behaviors. Namely, the stability of reporter mRNAs was independent of the presence or absence of an AUUUA instability element, a poly(A) tail, or even a 5′ methylated cap. Confocal microscopy showed that fluorescent RNAs introduced by liposome-mediated transfection were present in discrete particles. These observations imply that a number of control experiments are required when using liposome to mediated RNA transfection, and the possible consequences are discussed.
Multiscale modeling of solidification during laser cladding process
Authors: Cao Y. , Choi J.
Published: August 2006

Laser cladding is an additive manufacturing process in which a laser generates a melt pool on the substrate material while a second material in a powder or wire form is injected into that melt pool. Among all laser manufacturing processes, laser cladding offers the most extensive variety of possibilities to alter a component at its surface. Despite immense potential and advancements, the process model of microstructure evolution and its coupling with macro parameters of the laser cladding process has not been fully developed. To address this issue, a process model of microstructure evolution has been studied by utilizing a phase-field method. The phase-field method has become a widely used computational tool for the modeling of microstructure evolution with the advantage of avoiding tracking the interface explicitly and satisfying interfacial boundary conditions. In present work, the numerical solutions of a phase-field model have been analyzed. The linking of macroscale process and microstructure evolution was examined by considering the relationship of macro- and microparameters. The effects of thermal noise and melt undercooling on the solidification microstructure have also been studied. The predicted results with different undercoolings were compared with the microsolvability theory and a good agreement was found. Different solidification morphologies of different locations in the melt pool are also investigated. It was found that it is not the mass transfer but the heat transfer in the melt pool that dominates the solidification process.
Fatal postlymphoma chemotherapy hepatitis B reactivation secondary to the emergence of a YMDD mutant strain with lamivudine resistance in a noncirrhotic patient
Authors: Law Joanna K. , Ali Jaber Al , Harrigan P. Richard , Sherlock Christopher H. , Savage Kerry J. , Yoshida Eric M.
Published: August 2006

Hepatitis B reactivation is a well‐known complication during or after chemotherapy in chronic hepatitis B (HBV) carriers. The current practice guidelines in Canada and the United States recommends patients receive antiviral prophylaxis prior to the onset of chemotherapy in chronic HBV carriers with lamivudine. We report a case of a 57‐year‐old man with follicular lymphoma on lamivudine prophylaxis and no clinical evidence of cirrhosis, and developed fatal HBV reactivation after the emergence of a YMDD mutant strain of HBV that confers lamivudine resistance. Fatal reactivation secondary to the development of lamivudine resistance has not, to date, been well‐ reported. Our experience indicates the need to carefully monitor patients for suspected drug‐ resistant HBV mutants with the addition of anti‐viral agents effective against the YMDD mutational strain, when lamivudine resistance emerges. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.
Humanization of anti‐human insulin receptor antibody for drug targeting across the human blood–brain barrier
Authors: Boado Ruben J. , Zhang Yufeng , Zhang Yun , Pardridge William M.
Published: August 2006

A murine monoclonal antibody (MAb) to the human insulin receptor (HIR) has been engineered for use as a brain drug delivery system for transport across the human blood–brain barrier (BBB). The HIRMAb was humanized by complementarity determining region (CDR) grafting on the framework regions (FR) of the human B43 IgG heavy chain and the human REI kappa light chain. A problem encountered in the humanization process was the poor secretion of the CDR‐grafted HIRMAb by myeloma cells. This problem was solved by the production of human/mouse hybrids of the engineered heavy chain variable region (VH), which led to the replacement of five amino acids in the FR3 of the VH with original murine amino acids. No replacement of FR amino acids in the light chain variable region (VL) was required. The affinity of the humanized HIRMAb for the HIR was decreased 27% relative to the murine HIRMAb. The humanized HIRMAb avidly bound to the HIR of isolated human brain capillaries, which are used as an in vitro model system of the human BBB. The HIRMAb cross reacts with the HIR of Old World primates such as the Rhesus monkey. The humanized HIRMAb was radiolabeled with 125‐iodine, and injected intravenously into an adult, anesthetized Rhesus monkey. Brain scanning showed the humanized HIRMAb was rapidly transported into all parts of the primate brain after intravenous administration. The humanized HIRMAb may be used as a brain drug and gene delivery system for the targeting of large molecule therapeutics across the BBB in humans. Biotechnol. Bioeng. 2007;96: 381–391. © 2006 Wiley Periodicals, Inc.
Comparison of two continuous fungal bioreactors for posttreatment of anaerobically pretreated weak black liquor from kraft pulp mills
Authors: Ortega‐Clemente Alfredo , Marín‐Mezo G. , Ponce‐Noyola M.T. , Montes‐Horcasitas M.C. , Caffarel‐Méndez S. , Barrera‐Cortés Josefina , Poggi‐Varaldo Héctor M.
Published: August 2006

The purpose of this work was to evaluate and compare two continuous systems of posttreatment of anaerobically pretreated weak black liquor (WBL). The first system consisted of a packed bed reactor (PBR) with Trametes versicolor (Tv) immobilized on wood cubes of holm oak (biocubes). The second system was a fluidized bed reactor (FBR) with Lentinus edodes (Le) immobilized on wood cubes of holm oak. The reactors operated for 65 days at a hydraulic retention time (HRT) of 5 days, at 28°C, with continuous aeration. Response variables monitored were conventional and specific, unit, net removal efficiency (η and ηsun, respectively) of chemical oxygen demand (COD), color, and ligninoids, and enzymatic activities of manganese peroxidase (MnP), lignin peroxidase (LiP), laccase (Lac) and proteases. The PBR showed an average color η superior to that of the FBR (52.42 ± 21.78% and 25.34 ± 14.38% for PBR and FBR, respectively); removals of COD and ligninoids presented a similar pattern to that of color. Lac activity was significantly larger in PBR than in FBR. Activity of MnP in PBR was higher than that of the FBR (0.004 and 0.002 U MnP/mL, respectively). This difference could be ascribed to the different fungi present in each bioreactor. LiP activity was very low in both reactors. Average value of proteases was almost double in the FBR as compared with PBR (0.472 and 0.209 U Proteases/mL, respectively). During the last 2 weeks of operation, biocubes in the FBR experienced a significant loss of the attached Le biomass, probably by attrition. This and higher protease activity in the FBR could explain the lower pollutant removals achieved in the FBR. Overall, PBR with immobilized Tv showed a better performance than the FBR with Le for the posttreatment of the recalcitrant anaerobic effluent. Extended and sustained pollutant removal (65 days) was achieved in the PBR, although more research is needed to evaluate bioreactor performance at shorter hydraulic retention times. Biotechnol. Bioeng. 2007;96:640–650. © 2006 Wiley Periodicals, Inc.
Amino acid and manganese supplementation modulates the glycosylation state of erythropoietin in a CHO culture system
Authors: Crowell Christopher K. , Grampp Gustavo E. , Rogers Gary N. , Miller Janis , Scheinman Robert I.
Published: August 2006

The manufacture of secreted proteins is complicated by the need for both high levels of expression and appropriate processing of the nascent polypeptide. For glycoproteins, such as erythropoietin (EPO), posttranslational processing involves the addition of oligosaccharide chains. We initially noted that a subset of the amino acids present in the cell culture media had become depleted by cellular metabolism during the last harvest cycle in our batch fed system and hypothesized that by supplementing these nutrients we would improve EPO yields. By increasing the concentration of these amino acids we increased recombinant human erythropoietin (rHuEPO) biosynthesis in the last harvest cycle as expected but, surprisingly, we also observed a large increase in the amount of rHuEPO with a relatively low sialic acid content. To understand the nature of this process we isolated and characterized the lower sialylated rHuEPO pool. Decreased sialylation correlated with an increase in N‐linked carbohydrates missing terminal galactose moieties, suggesting that β‐1,4‐galactosyltransferase may be rate limiting in our system. To test this hypothesis we supplemented our cultures with varying concentrations of manganese (Mn2+), a cofactor for β‐1,4‐galactosyltransferase. Consistent with our hypothesis we found that Mn2+ addition improved galactosylation and greatly reduced the amount of rHuEPO in the lower sialylated fraction. Additionally, we found that Mn2+ addition increased carbohydrate site occupancy and narrowed carbohydrate branching to bi‐antennary structures in these lower sialylated pools. Surprisingly Mn2+ only had this effect late in the culture process. These data indicate that the addition of Mn2+ has complex effects on stressed batch fed cultures. Biotechnol. Bioeng. 2007;96: 538–549. © 2006 Wiley Periodicals, Inc.
Proton Transfer 200 Years after von Grotthuss: Insights from Ab Initio Simulations
Authors: Marx Dominik
Published: August 2006

In the last decade, ab initio simulations and especially Car–Parrinello molecular dynamics have significantly contributed to the improvement of our understanding of both the physical and chemical properties of water, ice, and hydrogen‐bonded systems in general. At the heart of this family of in silico techniques lies the crucial idea of computing the many‐body interactions by solving the electronic structure problem “on the fly” as the simulation proceeds, which circumvents the need for pre‐parameterized potential models. In particular, the field of proton transfer in hydrogen‐bonded networks greatly benefits from these technical advances. Here, several systems of seemingly quite different nature and of increasing complexity, such as Grotthuss diffusion in water, excited‐state proton‐transfer in solution, phase transitions in ice, and protonated water networks in the membrane protein bacteriorhodopsin, are discussed in the realms of a unifying viewpoint.
Freestanding Polyelectrolyte Films as Sensors for Osmotic Pressure
Authors: Nolte Marc , Dönch Ingo , Fery Andreas
Published: August 2006

Freestanding ultrathin polyelectrolyte‐multilayer membranes, transferred to topographically structured polydimethylsiloxane (PDMS), are used as mechanical sensors. Due to the membranes′ semipermeability, high‐molecular‐weight molecules can be either entrapped inside them or excluded, thus generating an osmotic pressure. This leads to a deformation. We investigate the deformation as a function of the osmotic pressure and present an analytical theory that fully describes the data. Thus, osmotic pressures can be determined quantitatively. The individual osmotic‐sensitive elements have only microscopic dimensions, and arrays can be easily produced.
Transitions: Dilemmas of leadership
Authors: Harris Sidney E.
Published: August 2006

The author explores his insights and lessons learned during service as a dean at two business schools.
Asymmetric biomimetic oxidations of phenols using oxazolidines as chiral auxiliaries: the enantioselective synthesis of (+)‐ and (−)‐dehydrodiconiferyl alcohol
Authors: Bruschi Maurizio , Orlandi Marco , Rindone Bruno , Rummakko Petteri , Zoia Luca
Published: August 2006

Stereoselective bimolecular radical coupling reactions of phenylpropenoid phenols are described. Evans's 2‐oxazolidinone 11a–d derivatives of ferulic acid were prepared and oxidized to give dimeric benzofuran neolignan structures 12–13a–d in 40–50% overall yields. The chiral phenols were dimerized either enzymatically with hydrogen peroxide and horseradish peroxidase (HRP) or with silver oxide. The enantioselectivity after reductive cleavage of the chiral auxiliaries to give dehydrodiconiferyl alcohol ranged from 18% to 62% enantiomeric excess. The conformational analysis and the activation energy using semiempirical PM3 calculations on the intermediate quinomethides is used to explain the observed stereoselectivity. Copyright © 2006 John Wiley & Sons, Ltd.
Structural and electronic properties of ScSb, ScAs, ScP and ScN
Authors: Tebboune AbdelGhani , Rached Djamel , Benzair AbdelNour , Sekkal Nadir , Belbachir A. H.
Published: August 2006

The structural and electronic properties of ScSb, ScAs, ScP and ScN III–V materials are investigated within a version of the first‐principles full potential linear muffin‐tin orbitals method (FPLMTO) that enables an accurate treatment of the interstitial regions. At high pressure, the transition from rocksalt (B1) to CsCl (B2) structure is found to be possible. The zinc blende phase is also investigated and is found to give a semiconductor behavior with a wide bandgap to all our materials. The latter is direct at X for ScAs, ScSb, ScP. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Microscopic evidence of the FFLO state in CeCoIn5 probed by NMR study
Authors: Kumagai K. , Kakuyanagi K. , Saitoh M. , Matsuda Y. , Takashima S. , Nohara M. , Takagi H.
Published: August 2006

An anomalous temperature dependence of 115In‐NMR spectrum is observed in the newly‐discovered high field and low temperature superconducting phase of CeCoIn5. The anomalies near the upper limit of H C 2 are attributed to spatially‐distributed local density of states of quasiparticles. From a simulation with the phenomenological model for the sinusoidally‐modulated superconducting order parameter, the present NMR study provides a microscopic evidence that the Fulde‐Ferrell‐Larkin‐Ovchinnikov (FFLO) state is realized at the high field phase in CeCoIn5. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Large magneto‐optic Kerr effect on double thin Mn/Sb films
Authors: Attaran‐Kakhki Ebrahim
Published: August 2006

The magneto‐optic effects are known phenomena on magnetic media; these effects could be used in magneto‐optics storages and switches. Recently; these effect are used in inducing the spintronic as well. In the present work we have considered the Kerr and Faraday effects on double evaporated Mn/Sb thin films. We evaporated a 100 nm Sb film on a cleaned glass substrate and then a 100 nm Mn film on top of the Sb layer. The prepared double film has been annealed in vacuum at about 150 °C for 5 hours. Then the magnet‐optic hysteresis loop of film has been plotted. From the hysteresis loop the optical rotation was calculated. The measurement shows an optical rotation up to one degree which is quit reasonable for this media. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetic properties of Fe‐(Nd, Sm)‐B amorphous alloys
Authors: Hassanain N. , Lassri H. , Berrada A. , Krishnan R.
Published: August 2006

The magnetization behaviour of amorphous alloys Fe80–xRExB20 (RE = Nd, Sm) with 0 ≤ x ≤ 16, prepared by melt‐spinning technique. The effect of rare earth substitution on the magnetic properties (Tc, M 0, Hc …) of amorphous alloy has been investigated. Using Random Magnetic Anisotropy Model (RMA), we have analysed our results and obtained some fundamental parameters. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pb substitution effect on the normal and superconductivity states transport of polycrystalline MgB2
Authors: Zouaoui M. , Annabi M. , Ben Azzouz F. , Ben Salem M.
Published: August 2006

A series of samples of Mg1–xPbxB2 were synthesized by the conventional solid state reaction method. Its temperature dependence of resistivity was studied from the zero resistivity temperature Tc up to 300 K. In order to more understand the main reason of the decreases of Tc, we analyse the resistivity versus temperature data in the normal state using Bloch‐Grüneisen formula. The Debye temperature, θD, has been extracted from the fits. θD is seen to decrease with the lead substitution from 1280 K to 835 K. Using θD and Tc, the electron‐phonon interaction parameter λ, has been given by McMillan equation. The values of λ increase from 0.70 to 0.84 respectively for x = 0% and x = 1% sample. The decrease in Tc is argued mainly by the decrease in the density of states at the Fermi level N(EF) with Pb concentration than the decrease in θD. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The effect of sintering temperature on the weak link behavior of Bi‐2223 superconductors
Authors: Kameli P. , Salamati H. , Eslami M. , Akhavan M.
Published: August 2006

We have studied the effect of sintering temperature on the weak link behavior of polycrystalline Bi2223 superconductors with different intergranular coupling using the XRD, electrical resistivity and AC susceptibility techniques. The XRD results show that by increasing sintering temperature up to 865 °C the Bi2212 phase fraction decrease. It was found that the Bi2212 phase on the grain boundaries is likely to play the role of weak links and consequently reduces the intergranular critical current densities. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pulmonary Nodule Resection During Lung Volume Reduction Surgery
Authors: Allen Gloria M. , DeRose Joseph J.
Published: August 2006

Lung volume reduction surgery (LVRS) and concomitant pulmonary nodule resection can improve the respiratory function of and remove malignant lesions in patients with chronic obstructive pulmonary disease and lung cancer. Previously, using standard selection criteria, some patients with emphysema who also had lung nodules were denied surgery because of the severity of their pulmonary dysfunction. In this article, the authors report improved pulmonary function in 11 patients with severe emphysema who underwent combined LVRS and nodule resection. AORN J 66 (Nov 1997)808‐818.
An Alcohol and Drug Education Program for Nurses
Authors: Markey Bernadine T. , Stone Joan B.
Published: August 2006

Alcohol and drug use and abuse present serious problems for health care professionals, both as clinicians and abusers. These topics, however, have not been addressed adequately in nursing curricula. Nurses need to know the effects that alcohol and drug use and abuse have on individuals, families, and society. In this article, the authors outline the framework for a course or presentation that reviews the problems and applies the nursing process to the issues. The course can be adapted to meet the needs of nurses in any discipline, including the perioperative area, as well as for other health care providers and community groups. Course content and teaching strategies are included.AORN J66 (Nov 1997) 845‐853.
Self‐Efficacy Enhanced Preoperative Instruction
Authors: Oetker‐Black S. , Teeters D. , Cukr P. , Rininger S.
Published: August 2006

Perioperative nurses traditionally have helped patients cope with the adversities of surgery through preoperative instruction. The authors conducted a study to determine whether an efficacy‐enhancing preoperative teaching protocol was effective in increasing preoperative self‐efficacy in patients scheduled to undergo laparoscopic cholecystectomy procedures with general anesthesia. The subjects were 60 surgical patients in a 156‐bed community hospital located in the midwestern United States. Analysis of covariance indicated there were no significant differences between groups after controlling for preoperative self‐efficacy. Further research is needed to determine whether an efficacy‐enhancing teaching protocol can improve selected short‐ and long‐term outcomes in surgical patients. AORN J 66 (Nov 1997) 854‐864.
Development and Implementation of a Perioperative Assistant Training Program
Authors: Messina Jeanette
Published: August 2006

Due to health care reform, many institutions have had to examine the way they deliver patient care. This article describes how, in response to this challenge, an interdisciplinary OR team at North Shore University Hospital, Manhasset, NY, developed and implemented the role of perioperative assistant in the OR. The authors describe the education curriculum for program completion, along with specific results. The program's difficulties and challenges are described, as well as what was learned as the program proceeded. The authors stress that program implementation depended on the efforts of all staff members, their willingness to help develop the perioperative assistant role, and their ability to function as a team. AORN J 66 (Nov 1997) 890‐904.
Powered Functional Endoscopic Sinus Surgery
Authors: Krouse H.J. , Parker C.M. , Purcell R. , Krouse J.H. , Christmas D.A.
Published: August 2006

The use of powered instrumentation in functional endoscopic sinus surgery has been a revolutionary development in the surgical treatment of chronic sinusitis. Several studies have demonstrated the safety, efficacy, and ease of use of this new technique. To provide support and coordinate the surgical process in powered functional endoscopic sinus surgery procedures, perioperative nurses must have an appreciation for its specific equipment handling and for appropriate patient care. This article describes a specific protocol that perioperative nurses can use to facilitate efficient and safe surgical environments for patients who undergo powered endoscopic sinus surgery procedures. AORN J 66 (Sept 1997) 405–414.
Computer‐assisted Endoscopic Sinus Surgery
Authors: Petroff Paula F.
Published: August 2006

Until the development and use of computer‐assisted localization technology in endoscopic sinus surgery procedures, surgical risks to patients undergoing endoscopic sinus surgery procedures included blindness, diplopia, or partial vision loss and damage to the cribriform plates and posterior roofs of their ethmoidal sinuses. Successful patient outcomes were dependent on the ability of surgeons to visualize surgical sites directly, to correlate data from two‐dimensional computed tomography scans, and to apply these data to anatomic landmarks. Advances in computer‐imaging modalities and computer‐assisted localization technology have eliminated many of the surgical problems and patient complications associated with early endoscopic sinus surgery procedures and have caused fundamental changes in the way otorhinolaryngologists diagnose and treat patients with sinus disease. AORN J 66 (Sept 1997) 416–425.
Stent‐Graft Placement Procedures for Descending Thoracic Aortic Aneurysms
Authors: Liston Sheilagh M.
Published: August 2006

Descending thoracic aortic aneurysms most often are caused by arteriosclerosis and appear most frequently in elderly males. These patients often are asymptomatic, but they may experience symptoms related to compression of adjacent thoracic structures, or they may present for treatment when their aneurysms rupture. Open surgical resections and repairs of descending thoracic aortic aneurysms are associated with bleeding, paraplegia, strokes, renal insufficiency, and the need for prolonged ventilatory support in the postoperative period. At Stanford (Calif) University Hospital, surgeons are placing endovascular stent‐grafts in patients with descending thoracic aortic aneurysms who meet specific anatomic selection criteria. This new treatment modality provides patients with a less invasive, less hazardous, and potentially less expensive alternative to open surgical resection and repair procedures. Preoperative teaching and skilled perioperative nursing care are essential for positive patient outcomes with stent‐graft treatment of descending thoracic aortic aneurysms. AORN J 66 (Sept 1997) 433–444.
An Orientation Program for Unlicensed Assistive Personnel
Authors: Nyberg Denise Bauer , Campbell Jamie L.
Published: August 2006

The nursing profession has worked with unlicensed assistive personnel (UAP) for decades; however, with the budget cuts resulting from health care redesign, some health care providers have expressed apprehension about UAP roles (eg, nurse aides, orderlies, unit clerks). Staff members in the perioperative services department at Children's Hospital Medical Center, Cincinnati, have defined a UAP role that enhances the OR's efficiency in patient care and maintains the cost‐effective measures outlined in the facility's strategic goals. A key element in the success of this perioperative UAP role implementation has been the development of a competency‐based orientation program that helps UAP develop and maintain their specific skills. AORN J 66 (Sept 1997) 445–454.