bluuebunny/crossref_metadata_2025 huggingface dataset:
The management of an accessory or replaced right hepatic artery during multiorgan retrieval: Results of an angiographic study
Authors: Cherian Thomas P. , Hegab Bassem , Oliff Simon P. , Wigmore Stephen J.
Published: March 2010

In the presence of anatomical variants such as an accessory or replaced (A/R) right hepatic artery (RHA), a conflict of interest can arise during organ retrieval between liver and pancreatic teams. This angiographic study examines the anatomy of the inferior pancreaticoduodenal artery (IPDA), its relation to the A/R RHA, and the implications for the use of livers and pancreases from multiorgan donors. Gastrointestinal angiograms performed in our institution for unrelated indications were reviewed, and the relevant arteries, their diameters, the distances between origins, the time at which variants were found, and the blood supply to relevant solid organs were recorded. A review of 122 angiograms identified 100 patients in whom both the superior mesenteric artery (SMA) and the celiac axis were cannulated synchronously; these patients composed our study cohort. The IPDA was identified in 95% of the cases. There were 8 patients with a replaced RHA and 4 with an accessory RHA. In all 12, the IPDA had an SMA origin; 3 of these shared a common origin with the A/R RHA on the SMA. In the rest, the mean distance between them was 29 mm (range = 17.8-48.3 mm). All anomalous arteries found were segmental vessels. In conclusion, the A/R RHA incidence in our series was 12%, and no case had an IPDA originating from the A/R RHA. Separate accessory RHA and IPDA origins potentially allow an uncompromised accessory RHA (with its Carrel patch) without risk of prejudice to the pancreatic graft if retrieval is accurately performed. Rarely (3%), there is a common origin between the A/R RHA and the IPDA, and back-bench reconstruction would be required to allow the use of both the liver and pancreas. Liver Transpl 16:742-747, 2010. © 2010 AASLD.
Block Copolymer‐Templated Synthesis and Organization of Semiconductor Nanocrystals
Authors: Karanikolos G. N. , Alexandridis P. , Mountziaris T. J.
Published: March 2010

Summary: Templates formed by the self‐assembly of amphiphilic block copolymers in selective solvents have been found to be instrumental in controlling critical parameters in semiconductor nanomaterials fabrication, including particle size, shape, and composition. These tunable nanoreactors exhibit rich polymorphism and have enabled the synthesis of a variety of nanostructures such as dots, wires, tubes, hollow spheres, and 2‐D structures by growth‐under‐confinement at room temperature. The encapsulated particles have optical and electronic properties that are dependent upon physical dimensions and morphology, and exhibit inherent stability and functionalization flexibility, thus opening up promising prospects through their integration into functional optoelectronic and biological systems.
Synthesis of Poly(Alkyl Cyanoacrylates) as Biodegradable Polymers for Drug Delivery Applications
Authors: Dossi M. , Storti G. , Moscatelli D.
Published: March 2010

Summary: Poly(alkyl cyanoacrylates) are biodegradable and biocompatible polymers. Ethyl, n‐butyl and octyl cyanoacrylate have been approved in the last decades by the US Food and Drug Administration (FDA) and novel applications are continuously appearing. Recently, such polymers have been proposed as raw materials for the synthesis of nanoparticles aimed to drug delivery. In the literature, such nanoparticles have been always produced through heterogeneous polymerization processes in water. In this work, the anionic polymerization of ethyl, n‐butyl and octyl‐cyanoacrylate in water is systematically investigated. Optimum conditions for the process are identified by changing reaction temperature and solution pH. It is found that an aqueous dispersion medium at pH around 5 and 65 °C gives the best results in terms of polymer molecular weight for all monomers, even if the process exhibits the dominant production of low molecular weight (LMW) polymer. On the other hand, the amount of high molecular weight polymer becomes noticeable at room temperature.
In Line Monitoring of VAc‐BuA Emulsion Polymerization Reaction in a Continuous Pulsed Sieve Plate Reactor using NIR Spectroscopy
Authors: Chicoma Dennis , Carranza Verónica , Sayer Claudia , Giudici Reinaldo
Published: March 2010

Summary: This work deals with the in line and in situ monitoring of the changes in residual monomer concentrations and polymer particle size in the process of emulsion copolymerization of vinyl acetate (VAc) and butyl acrylate (BuA) over the sections of a novel tubular reactor (pulsed sieve plate continuous reactor, PSPC) using NIR spectroscopy. Off‐line measurements (gas chromatographic, gravimetric and dynamic light scattering) were used as reference for the development of the multivariate PLS calibration model. All NIR spectra were on‐line collected with an IFS 28/N Bruker spectrometer using a probe (transflectance mode) immersed into the reaction medium. The calibration model and validation data were analyzed using the OPUS/QUANT software. The results indicated that there exists a good agreement between values from the NIR calibration models and the off‐line reference measured experimental data. Moreover, the on‐line NIR can detect efficiently the occurrence of disturbances during the polymerization reaction, a useful tool for the improving the process safety.
Effect of Stabilizer Concentration, Pressure and Temperature on Polymerization Rate and Molecular Weight Development in RAFT Polymerization of MMA in scCO2
Authors: Jaramillo‐Soto Gabriel , García‐Morán Pedro R. , Vivaldo‐Lima Eduardo
Published: March 2010

Summary: An experimental study on the effect of stabilizer concentration, pressure (100 to 500 bar), and temperature (65 to 85 °C) on polymerization rate and molecular weight development in the reversible addition‐fragmentation chain transfer (RAFT) polymerization of methyl methacrylate (MMA) in supercritical carbon dioxide (scCO2) is presented. AIBN was used as initiator, S‐Thiobenzoyl thioglycolic acid as RAFT agent, and Krytox® 257 FSL as stabilizer. It was observed that the polymerization proceeded in a controlled manner. High conversions can be reached in reasonable times. Fairly low polydispersities (around 1.2) are possible if either pressure or temperature are increased, but better results are obtained if the polymerization proceeds at the upper temperature value of 85 °C.
Electrical Properties Investigation in PA12/PANI Composites
Authors: Mezdour Dounia zed , Tabellout Mohamed , Sahli Salah , Fatyeyeva Kateryna
Published: March 2010

Summary: Volume conducting PA‐12 based composites powders were chemically prepared by in situ polymerization and aniline doping at room temperature. These kinds of polyamide / PANI composites were investigated regarding their electrical properties. Their ac and dc electrical properties measured in the frequency range of 10−2–107 Hz are reported and the frequency dependence of electrical conductivity was investigated as a function of PANI concentration leading to the determination of the conductivity. The experimental conductivity was found to increase continuously with PANI content and explained by percolation theory with a relatively low percolation threshold of about 0.4 wt.%. The dielectric behavior of various PANI polymer composites has been characterized by the critical frequency ωc (denoting the crossover from the dc plateau of the conductivity to its frequency dependent ac behaviour). Modelling the conductivity behavior versus volume fraction using Slupkowski approach has revealed that the considered parameters are not sufficient to describe the electrical conductivity behavior.
Synthesis of Poly(3,4‐ethylenedioxythiophene) Hollow Spheres in CTAB/DBS — Mixed Surfactant Solutions
Authors: Sui Jing , Zhang Lijuan , Travas‐Sejdic Jadranka , Kilmartin Paul A.
Published: March 2010

Summary: Hollow microspheres of PEDOT (poly(3,4‐ethylenedioxythiophene) ranging from 0.5 to 10 µm have been synthesized by chemically oxidative polymerization of EDOT(3,4‐ethylenedioxythiophene) using ammonium persulfate in a catanionic surfactant solution obtained by mixing cetyltrimethylammonium bromide (CTAB) and sodium dodecylbenzenesulfonate (SDBS). The effect of the molar ratio of CTAB to SDBS on the morphology of the PEDOT oxidation products has been investigated using SEM and TEM and by an analysis of the structural properties using UV‐visible, FTIR and Raman spectroscopies, elemental analysis and conductivity measurements. The electro‐catalytic activity of PEDOT hollow microspheres for the oxidation of ascorbic acid was investigated by cyclic voltammetry in a pH 6 citrate/phosphate buffer solution and compared to the activity of granular PEDOT particles formed in the absence of the catanionic surfactant.
Effect of Phosphorus‐Nitrogen Intumescent Flame Retardant on Structure and Properties of Poly(propylene)
Authors: Vuillequez A. , Lebrun M. , Ion R.M. , Youssef B.
Published: March 2010

Summary: Phosphorus‐nitrogen intumescent product (R2000) was filled into polypropylene (PP) as a flame retardant. The neat PP and flame‐retarded PP blends were studied for their structural and mechanical properties after verification of the flame retardancy character of blends. In this paper, the influence of incorporation of different amount (5%, 10%, 15%, 20%, and 25%) of R2000 was studied. The flame retardancy is evaluated by limiting oxygen index (LOI) value, which is enhanced from 17.5 for pure PP to 22.7 for the blend comprising 15% intumescent product, phosphorus‐nitrogen based (R2000). The thermal degradation behaviour of the PP/R2000 blends was investigated using thermogravimetric analysis (TGA) under nitrogen (N2) and oxygen (O2) atmospheres. The influence of the R2000 on the PP crystallization was examined by X‐ray diffraction (XRD) and differential scanning calorimetry (DSC). Further, the mechanical properties of the materials were studied by dynamic mechanical analysis (DMA). The incorporation of the flame retardant had no effect on the crystallization of the neat polymer and the mechanical properties of the materials remained unaffected.
Microindentation Hardness of Nanostructured Thermoplastic Materials
Authors: Adhikari Rameshwar , Khatri Shiva K. , Adhikari Santosh , Michler Goerg H. , Calleja Francisco J. Balta
Published: March 2010

Summary:The micromechanical behaviour of various thermoplastics based nanocomposites was investigated with the aid of the microindentation technique. The materials studied were microphase separated styrene‐butadiene block copolymer systems and several thermoplastics reinforced with nano‐sized fillers having variable dimensionality. It was found that the microhardness behaviour of the nanocomposites studied was strongly influenced by the dimensionalities of the filler. Due to large surface to volume‐ratio one‐ and two‐dimensional fillers exhibit a far better reinforcing behaviour than the three dimensional ones. In case of nanostructured block copolymers, the microhardness is not determined by the total polystyrene (PS)/polybutadiene (PB) composition alone but diminishes gradually in presence of freely standing dangling polybutadiene chains even if the morphology of the systems remains unaltered.
A dual mortar approach for 3D finite deformation contact with consistent linearization
Authors: Popp Alexander , Gitterle Markus , Gee Michael W. , Wall Wolfgang A.
Published: March 2010

In this paper, an approach for three‐dimensional frictionless contact based on a dual mortar formulation and using a primal–dual active set strategy for direct constraint enforcement is presented. We focus on linear shape functions, but briefly address higher order interpolation as well. The study builds on previous work by the authors for two‐dimensional problems. First and foremost, the ideas of a consistently linearized dual mortar scheme and of an interpretation of the active set search as a semi‐smooth Newton method are extended to the 3D case. This allows for solving all types of nonlinearities (i.e. geometrical, material and contact) within one single Newton scheme. Owing to the dual Lagrange multiplier approach employed, this advantage is not accompanied by an undesirable increase in system size as the Lagrange multipliers can be condensed from the global system of equations. Moreover, it is pointed out that the presented method does not make use of any regularization of contact constraints. Numerical examples illustrate the efficiency of our method and the high quality of results in 3D finite deformation contact analysis. Copyright © 2010 John Wiley & Sons, Ltd.
Least‐square‐based radial basis collocation method for solving inverse problems of Laplace equation from noisy data
Authors: Mao Xian‐Zhong , Li Zi
Published: March 2010

The inverse problem of 2D Laplace equation involves an estimation of unknown boundary values or the locations of boundary shape from noisy observations on over‐specified boundary or internal data points. The application of radial basis collocation method (RBCM), one of meshless and non‐iterative numerical schemes, directly induces this inverse boundary value problem (IBVP) to a single‐step solution of a system of linear algebraic equations in which the coefficients matrix is inherently ill‐conditioned. In order to solve the unstable problem observed in the conventional RBCM, an effective procedure that builds an over‐determined linear system and combines with least‐square technique is proposed to restore the stability of the solution in this paper. The present work investigates three examples of IBVPs using over‐specified boundary conditions or internal data with simulated noise and obtains stable and accurate results. It underlies that least‐square‐based radial basis collocation method (LS‐RBCM) poses a significant advantage of good stability against large noise levels compared with the conventional RBCM. Copyright © 2010 John Wiley & Sons, Ltd.
Chemical synthesis and characterization of wild‐type and biotinylated N‐terminal domain 1–64 of β2‐glycoprotein I
Authors: Pozzi Nicola , Banzato Alessandra , Bettin Samuele , Bison Elisa , Pengo Vittorio , De Filippis Vincenzo
Published: March 2010

The antiphospholipid syndrome (APS) is a severe autoimmune disease associated with recurrent thrombosis and fetal loss and characterized by the presence of circulating autoantibodies (aAbs) mainly recognizing the N‐terminal domain (DmI) of β2‐glycoprotein I (β2GpI). To possibly block anti‐β2GpI Abs activity, we synthesized the entire DmI comprising residues 1–64 of β2GpI by chemical methods. Oxidative disulfide renaturation of DmI was achieved in the presence of reduced and oxidized glutathione. The folded DmI (N‐DmI) was purified by RP‐HPLC, and its chemical identity and correct disulfide pairing (Cys4‐Cys47 and Cys32‐Cys60) were established by enzymatic peptide mass fingerprint analysis. The results of the conformational characterization, conducted by far‐ and near‐UV CD and fluorescence spectroscopy, provided strong evidence for the native‐like structure of DmI, which is also quite resistant to both Gdn‐HCl and thermal denaturation. However, the thermodynamic stability of N‐DmI at 37°C was remarkably low, in agreement with the unfolding energetics of small proteins. Of note, aAbs failed to bind to plates coated with N‐DmI in direct binding experiments. From ELISA competition experiments with plate‐immobilized β2GpI, a mean IC50 value of 8.8 μM could be estimated for N‐DmI, similar to that of the full‐length protein, IC50(β2GpI) = 6.4 μM, whereas the cysteine‐reduced and carboxamidomethylated DmI, RC‐DmI, failed to bind to anti‐β2GpI Abs. The versatility of chemical synthesis was also exploited to produce an N‐terminally biotin‐(PEG)2‐derivative of N‐DmI (Biotin‐N‐DmI) to be possibly used as a new tool in APS diagnosis. Strikingly, Biotin‐N‐DmI loaded onto a streptavidin‐coated plate selectively recognized aAbs from APS patients.
A rapid protein folding assay for the bacterial periplasm
Authors: Mansell Thomas J. , Linderman Stephen W. , Fisher Adam C. , DeLisa Matthew P.
Published: March 2010

An array of genetic screens and selections has been developed for reporting protein folding and solubility in the cytoplasm of living cells. However, there are currently no analogous folding assays for the bacterial periplasm, despite the significance of this compartment for the expression of recombinant proteins, especially those requiring important posttranslational modifications (e.g., disulfide bond formation). Here, we describe an engineered genetic selection for monitoring protein folding in the periplasmic compartment of Escherichia coli cells. In this approach, target proteins are sandwiched between an N‐terminal signal recognition particle (SRP)‐dependent signal peptide and a C‐terminal selectable marker, TEM‐1 β‐lactamase. The resulting chimeras are localized to the periplasmic space via the cotranslational SRP pathway. Using a panel of native and heterologous proteins, we demonstrate that the folding efficiency of various target proteins correlates directly with in vivo β‐lactamase activity and thus resistance to ampicillin. We also show that this reporter is useful for the discovery of extrinsic periplasmic factors (e.g., chaperones) that affect protein folding and for obtaining folding‐enhanced proteins via directed evolution. Collectively, these data demonstrate that our periplasmic folding reporter is a powerful tool for screening and engineering protein folding in a manner that does not require any structural or functional information about the target protein.
Prostate cancer characteristics and survival in males of African Ancestry according to place of birth: Data from Brooklyn—New York, Guyana, Tobago and Trinidad
Authors: Mutetwa Batsirai , Taioli Emanuela , Attong‐Rogers Alison , Layne Penelope , Roach Veronica , Ragin Camille
Published: March 2010

BACKGROUND

Prostate cancer mortality rates for African‐Americans are much higher than Caucasians and a similar trend is observed for prostate cancer survival. Data on recently immigrated African‐descent men are lacking.

METHODS

Using cancer registry data from Brooklyn, NY and two countries in the Caribbean (Guyana and Trinidad and Tobago), survival rates were estimated. We also examined whether Black race or Caribbean birthplace predict prostate cancer survival among males living in the United States (US).

RESULTS

The Caribbean cases were diagnosed at a later age than those in the US (Guyana: 74.5 years, Trinidad and Tobago: 72.4 years, Brooklyn: 65.8 years). Patients in the Caribbean had a worse 5‐year survival rate compared to those in the US (41.6% vs. 84.4%) but for immigrant Caribbean‐born males living in the US the 5‐year survival rate was not significantly different from African‐Americans (78.1%, 95% CI: 70.9–83.7% vs. 81.4%, 95% CI: 69.5–89.1%, P = 0.792). The risk of death for Caribbean‐born was more than three times higher than US‐born men (HR: 3.43, 95% CI: 2.17–5.44, adjusted for ethnicity, stage, and mean age of diagnosis). A mean age of diagnosis >65 years old and stage IV disease, but not ethnicity, were found to be independently associated with the risk of death.

CONCLUSION

The survival disadvantage for Caribbean‐born patients may be partly due to later diagnosis. Interventions focused on screening, education about the disease and early detection could potentially reduce cancer mortality in this population. Prostate 70: 1102–1109, 2010. © 2010 Wiley‐Liss, Inc.
Relaxin drives Wnt signaling through upregulation of PCDHY in prostate cancer
Authors: Thompson Vanessa C. , Hurtado‐Coll Antonio , Turbin Dmitry , Fazli Ladan , Lehman Melanie L. , Gleave Martin E. , Nelson Colleen C.
Published: March 2010

BACKGROUND

Relaxin, a potent peptide hormone of the insulin‐like family normally produced and secreted by the human prostate, is upregulated in castrate resistant prostate cancer progression. In various tissues, relaxin increases angiogenesis and cell motility through upregulation of vascular endothelial growth factor, matrix metalloproteases, and nitric oxide, and therefore maybe an attractive target for cancer therapeutics.

METHODS

To examine the role of relaxin in prostate cancer progression, LNCaP cells stably transfected with relaxin (LNCaPRLN) were used to form xenograft tumors, and microarray expression analysis was subsequently performed to determine novel pathways regulated by relaxin. Prostate cancer tissue microarrays from patient samples were stained by immunohistochemistry for further validation and correlation of the findings.

RESULTS

Expression analysis identified novel relaxin regulated pathways, including the ProtocadherinY (PCDHY)/Wnt pathway. PCDHY, which upregulates Wnt11, has previously been shown to stabilize β‐catenin, causing β‐catenin to translocate from the cytoplasmic membrane to the nucleus and initiate TCF‐mediated signaling. LNCaPRLN xenografts exhibit increased PCDHY expression and increased cytoplasmic localization of β‐catenin, suggesting relaxin directs Wnt11 overexpression through PCDHY upregulation. Similarly, prostate cancer samples from patients who have undergone androgen ablation have increased Wnt11 expression, which is further upregulated in castrate resistant tissues. Like relaxin, Wnt11, and PCDHY are negatively regulated by androgens, and further analysis indicated that the overexpression of relaxin results in dysregulation of androgen‐regulated genes.

CONCLUSIONS

These data suggest that prostate cancer cell motility and altered androgen receptor activity attributed to relaxin may be mediated in part by Wnt11. Prostate 70: 1134–1145, 2010. © 2010 Wiley‐Liss, Inc.
Acute inflammation promotes early cellular stimulation of the epithelial and stromal compartments of the rat prostate
Authors: Quintar Amado A. , Doll Andreas , Leimgruber Carolina , Palmeri Claudia M. , Roth Felix D. , Maccioni Mariana , Maldonado Cristina A.
Published: March 2010

BACKGROUND

It has been proposed that prostatic inflammation plays a pivotal role in the pathophysiology of benign hyperplasia and prostate cancer. However, little information is available about the prostatic reaction to bacterial compounds in vivo. Our aim was therefore to evaluate the early effects of bacterial infection on rat ventral prostate compartments.

METHODS

Using a rat model of acute bacterial prostatitis by Escherichia coli, we analyzed the histological and ultrastructural changes in the prostate at 24, 48, and 72 hr postinfection. Prostatic tissues were immunostained for prostatic binding protein (PBP), ACTA2, ErbB1, and ErbB2 receptors, TUNEL, and markers of cell proliferation. Dot and Western blots for PBP, ACTA2, ErbB1, ErbB2, and TGFβ1 were also performed.

RESULTS

The prostatic epithelium became hypertrophied, with increases in PBP and ErbB1 expression at 24 hr postinfection. Moreover, inflammation induced the expression of ErbB2, a receptor strongly involved in carcinogenesis. These alterations were more pronounced at 48 hr, but the epithelium also showed apoptosis and finally atrophy at 72 hr postinfection, with a decrease in PBP and ErbB receptors. Interestingly, the epithelial cells exhibited a high level of proliferation in response to the bacteria. The stromal reaction to acute inflammation was initially characterized by smooth muscle hypertrophy. Afterwards, muscle cells acquired a secretory phenotype, with a reduction in ACTA2 at 72 hr postinfection.

CONCLUSIONS

Prostatic inflammation, even at the early stages, promotes atrophic and proliferative changes, and the upregulation of ErbB receptors together with dedifferentiation of smooth muscle cells. These data suggest that repetitive reinfections could lead to uncontrolled growth in the prostate gland. Prostate 70: 1153–1165, 2010. © 2010 Wiley‐Liss, Inc.
Association between integrin expression and prognosis in localized prostate cancer
Authors: Pontes‐Júnior José , Reis Sabrina Thalita , de Oliveira Luis Carlos Neves , Sant'Anna Alexandre C. , Dall'Oglio Marcos Francisco , Antunes Alberto Azoubel , Ribeiro‐Filho Leopoldo Alves , Carvalho Paulo Afonso , Cury Jose , Srougi Miguel , Leite Kátia Ramos Moreira
Published: March 2010

BACKGROUND

Integrins and other adhesion molecules are essential for maintaining the epithelial phenotype. Some studies have reported correlations between abnormalities in their expression and carcinogenesis, but their role in prostate cancer is unclear. Our aim was to study the expression profile of integrins in surgical specimens of prostate cancer and associate their expression patterns with patient outcomes.

METHODS

We selected 111 patients with localized prostate cancer who had undergone radical prostatectomy. Of these patients, 60 had no tumor recurrence after a median follow‐up of 123 months. Integrin expression was evaluated by immunohistochemistry in a tissue microarray containing two tumor samples per patient. A semiquantitative analysis was employed. We measured the association between the expression of eight integrins and tumor recurrence.

RESULTS

Multivariate analysis showed that expression of α3 and α3β1 was related to worse outcome. When α3 expression was strong and α3β1 expression was positive, the odds of recurrence were 3.0‐ and 2.5‐fold higher, respectively. Only 19% and 28% of patients were recurrence‐free in a mean period of 123 months of follow up when their tumors showed strong α3 or positive α3β1 immuno‐expression, respectively.

CONCLUSIONS

We have shown that the expression of integrin α3β1 was independently associated with tumor recurrence after radical prostatectomy, suggesting that this integrin is a potential prognostic marker. Prostate 70: 1189–1195, 2010. © 2010 Wiley‐Liss, Inc.
Electronic structure of a realistic model of amorphous graphene
Authors: Kapko V. , Drabold D. A. , Thorpe M. F.
Published: March 2010

In this note, we calculate the electronic properties of a realistic atomistic model of amorphous graphene. The model contains odd‐membered rings, particularly five and seven membered rings and no coordination defects. We show that odd‐membered rings increase the electronic density of states at the Fermi level relative to crystalline graphene; a honeycomb lattice with semi‐metallic character. Some graphene samples contain amorphous regions, which even at small concentrations, may strongly affect many of the exotic properties of crystalline graphene, which arise because of the linear dispersion and semi‐metallic character of perfectly crystalline graphene. Estimates are given for the density of states at the Fermi level using a tight‐binding model for the π states.
Determination of the etching mechanism in MgS and ZnMgSSe epitaxial lift‐off layers
Authors: Curran Arran , Brown Spyros , Warburton Richard J. , Prior Kevin A.
Published: March 2010

During epitaxial lift‐off of II‐VI semiconductors a sacrificial layer of MgS is dissolved by acid. Here we show that the etching speed of this process varies inversely as the square root of the layer thickness, following a model developed previously for III‐V lift‐off where the rate limiting step in both cases is transport of insoluble product gases from the etching layer. We also propose a model to explain why sacrificial layer etching fails when strong cohesive forces resist the lifting of the epilayer. This occurs when the sacrificial layer is too thin or when it contains more than a critical amount of an insoluble component, cohesion arising from dispersion forces or chains of insoluble atoms, respectively.
Terahertz photoconductivity of a two‐dimensional electron gas in HgCdTe/HgTe quantum wells
Authors: Vasilyev Yu. B. , Gouider F. , Bugár M. , Nachtwei G. , Könemann J. , Brüne C. , Buhmann H.
Published: March 2010

The terahertz (THz) photoconductivity is investigated in HgTe/HgCdTe‐quantum wells (QWs) in Corbino geometry at various wavelengths of excited radiation. The radiation source is a p‐Ge cyclotron laser (pulse width about 1 µs, repetition rate 1 Hz) which is tunable in the wavelength range 120 µm < λ < 180 µm by an external magnetic field. It is shown that the photoconductivity is caused by the heating of two‐dimensional electron gas (2DEG). A rough estimation yields relaxation time around 0.46 µs. Because of the low effective mass, this material system is especially interesting for detector applications.
Optically detected magnetic resonance in CdMnSe/ZnSe submonolayer quantum wells
Authors: Tolmachev D. O. , Babunts R. A. , Romanov N. G. , Baranov P. G. , Namozov B. R. , Kusrayev Yu. G. , Lee S. , Dobrowolska M. , Furdyna J. K.
Published: March 2010

Fine structure of isolated Mn2+ ions in CdMnSe/ZnSe quantum wells (QWs) is revealed by optically detected magnetic resonance (ODMR) recorded by monitoring both exciton emission and intra‐Mn luminescence in the presence of simultaneous microwave irradiation. A large decrease of photoluminescence (PL) intensity of excitons and an increase of PL intensity of Mn2+ ions is observed when an applied magnetic field satisfies the Mn2+ electron paramagnetic resonance (EPR) condition. This suggests that a spin‐dependent energy transfer from excitons to intra‐Mn excitations occurs at the EPR condition.
Annealing effects and generation of secondary phases in ZnO after high‐dose transition metal implantation
Authors: Geurts J. , Schumm M. , Koerdel M. , Ziereis C. , Müller S. , Ronning C. , Dynowska E. , Gołacki Z. , Szuszkiewicz W.
Published: March 2010

ZnO crystals implanted with up to 16 at% Mn, Fe, Co, and Ni, respectively, were studied with microRaman spectroscopy and X‐ray diffraction. After stepwise thermal treatment of the samples in air up to 900 °C, we analyzed the influence of annealing on the formation of secondary phases and the evolution of their microstructure. After a considerable recovery of the radiation damaged ZnO lattice by treatment at 500 °C, the 700 °C step induces for transition metal (TM) concentrations ≥8 at% a strongly TM dependent formation of various stoichiometric and non‐stoichiometric TM oxide precipitates as well as elemental TM clusters. The annealing at 900 °C generally further modifies the amount as well as the chemical composition of the secondary phases.
Teaching and learning science as argument
Authors: Kuhn Deanna
Published: March 2010

The concept of science as argument, and the view that engaging in scientific argumentation should play a key role in science education, has become widely endorsed. The case is made here that this objective will be enhanced by broad understanding of the nature of argument skills and their directions and patterns of development. A line of research directed to this goal is described. © 2010 Wiley Periodicals, Inc. Sci Ed 94:810–824, 2010
The effects of mindfulness‐based group intervention on the mental health of middle‐aged Korean women in community
Authors: Lee Woo Kyeong , Bang Hee Jeong
Published: March 2010

This study was conducted to develop a mindfulness and self‐compassion enhancement intervention for middle‐aged women who complained of emotional distress and to ascertain whether participation in the mindfulness‐based programme was associated with an increase in psychological well‐being and the improvement of psychological symptoms. The results showed that time by group interactions were significant in improving psychological well‐being, depression, anxiety, hostility, somatization, positive affect (PA) and negative affect (NA). These results suggest that participants in the mindfulness and self‐compassion group programme appeared to have enhanced psychological well‐being and improved psychological distress. The study findings also suggest that mindfulness and self‐compassion enhancement programme may be an intervention with potential for helping many individuals to learn to deal with emotional distress. Copyright © 2010 John Wiley & Sons, Ltd.
Three‐Dimensional Fabrication at Small Size Scales
Authors: Leong Timothy G. , Zarafshar Aasiyeh M. , Gracias David H.
Published: March 2010

Despite the fact that we live in a 3D world and macroscale engineering is 3D, conventional submillimeter‐scale engineering is inherently 2D. New fabrication and patterning strategies are needed to enable truly 3D‐engineered structures at small size scales. Here, strategies that have been developed over the past two decades that seek to enable such millimeter to nanoscale 3D fabrication and patterning are reviewed. A focus is the strategy of self‐assembly, specifically in a biologically inspired, more deterministic form, known as self‐folding. Self‐folding methods can leverage the strengths of lithography to enable the construction of precisely patterned 3D structures and “smart” components. This self‐assembly approach is compared with other 3D fabrication paradigms, and its advantages and disadvantages are discussed.

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Frontispiece images reprinted with permission from References25,55,138,80, copyrights 2009, Nature Publishing Group, 2006 and 2007, IOP Publishing, 2001, Conference of Photopolymer Science and Technology, and with permission from Adam Cohen, Microfabrica Inc.
Chemical synthesis of homogeneous glycopeptides and glycoproteins
Authors: Kajihara Yasuhiro , Yamamoto Naoki , Okamoto Ryo , Hirano Kiriko , Murase Takefumi
Published: March 2010

Oligosaccharides linked to proteins are known to play important roles in several biological events. However, oligosaccharides are heterogeneous, which has hindered detailed elucidation of oligosaccharide functions. In order to solve this problem, glycoproteins having homogeneous oligosaccharides have long been required. For this purpose, an efficient preparative method of complex‐type oligosaccharides has been investigated from a natural source and this method was found to afford over 24 kinds of diverse complex‐type oligosaccharides by use of chemical methods and branch‐specific sequential glycosidase digestion. The sufficient amount of homogeneous complex type oligosaccharides obtained enabled us to examine the synthesis of homogeneous glycopeptides as well as glycoproteins by use of solid phase glycopeptide synthetic method and native chemical ligation. This review describes recent progress related to the efficient method of oligosaccharide preparation and synthesis of glycoproteins including bioactive erythropoietin. © 2010 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 10: 80–100; 2010: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.200900024
Odor representations in the mammalian olfactory bulb
Authors: Khan Adil Ghani , Parthasarathy K. , Bhalla Upinder Singh
Published: March 2010

A first key step in studying a sensory modality is to define how the brain represents the features of the sensory stimulus. This has proven to be a challenge in olfaction, where even the stimulus features have been a matter of considerable debate. In this review, we focus on olfactory representations in the first stage of the olfactory pathway, the olfactory bulb (OB). We examine the diverging viewpoints on spatially organized versus distributed representations. We then consider how odor sampling through respiration is a key part of the odorant code. Finally, we ask how the bulb handles the challenging task of representing mixtures. We suggest that current evidence points toward a representation that is spatially organized at the inputs but later distributed, with the spatial organization not being used for much computation. Nevertheless, this is a simple representation that effectively represents multiple individual odorants, as well as odor mixtures. Copyright © 2010 John Wiley & Sons, Inc.

This article is categorized under:

Models of Systems Properties and Processes > Mechanistic Models
Noninvasive analysis of fecal reproductive hormone metabolites in female veiled chameleons (Chamaeleo calyptratus) by enzyme immunoassay
Authors: Kummrow Maya S. , Gilman Christine , Mackie Paula , Smith Dale A. , Mastromonaco Gabriela F.
Published: March 2010

The noninvasive technique of gonadal steroid metabolite measurement in feces for evaluation of reproductive activity has proven an effective and important tool for population management in various captive species, but has not yet been validated and used in reptile species. In this study, enzyme immunoassays (EIAs) were validated for the analysis of fecal samples from female veiled chameleons (Chamaeleo calyptratus) for estrogen (E2), testosterone (T), and progesterone (P) and their metabolites. High performance liquid chromatography and physiological methods (GnRH stimulation) were used for the validation of the assays. Biological events, such as skin color changes indicative of ovarian activity and oviposition, correlated with the cyclical pattern of E2, T and P metabolites in feces over a period of two reproductive cycles. This is the first study to report frequent longitudinal measurements of fecal hormone levels by EIA in a reptile species. Zoo Biol 30:95–115, 2011. © 2010 Wiley‐Liss, Inc.
Evaluation of an alternative to feeding whole frozen fish in belugas (Delphinapterus leucas)
Authors: Mazzaro Lisa M. , Richmond Julie P. , Morgan Jessica N. , Kluever Michaela E. , Dunn J. Lawrence , Romano Tracy A. , Zinn Steven A. , Koutsos Elizabeth A.
Published: March 2010

Feeding fish to captive piscivores can be challenging owing to cost, availability, variability in nutrient, and caloric composition, as well as handling and storage concerns. This trial evaluated the response of three belugas to being fed Fish Analog, an alternative to frozen fish. Body condition, gut transit time, serum chemistry and metabolic hormone analytes, immune function, and behavioral motivation were the dependent variables. Belugas (n=3) were fed various levels of Fish Analog (0–50%) over a 6‐month period, and follow‐up studies were conducted to further examine several dependent variables. When provided in gradually increasing amounts, belugas consumed the Fish Analog, with only minor fecal consistency changes and without behavioral responses indicative of gastric discomfort. Axillary girth and blubber thickness were positively correlated, and did not differ significantly with changes in the percentage of Fish Analog fed. Individual animal variation in initial passage time, some serum chemistry analytes, and immune function differences were noted following feeding of Fish Analog. Feeding Fish Analog reduced blood n9 fatty acids compared with captive belugas fed no Fish Analog. Feeding a DHA‐enriched Fish Analog increased several n3 fatty acids, including eicosapentaenoic acid, but not DHA, compared with whales fed no Fish Analog or non‐DHA‐enriched Fish Analog. Fish Analog was shown to be a viable alternative to feeding fish at up to 50% of the dietary caloric density. Zoo Biol 30:32–51, 2011. © 2010 Wiley‐Liss, Inc.
Reconsidering evidence-based policy: Key issues and challenges
Authors: Head Brian W
Published: March 2010

The evidence-based policy (EBP) movement has sought to promote rigorous analysis of service programs and policy options in order to improve the quality of decision-making. Rigorous research findings are seen as useful and necessary inputs for policy-makers in their ongoing consideration of policy development and program review. This article provides a critical overview of the research literature on evidence-based policy in the context of government policy-making and program improvement. Particular attention is given to the rational expectation that improved policy analysis will flow from a better evidence base, with consequent improvements in the service delivery and problem-solving capacities of government agencies. This expectation is contrasted with the practical limitations on rational processes typical in the real world of political decision-making, which is characterised by bargaining, entrenched commitments, and the interplay of diverse stakeholder values and interests. Key issues for consideration include the forms of evidence that are of greatest relevance or utility for decision-makers, and the most productive forms of interaction between the producers and the users of research and evaluation findings.
Expression of Na+/glucose co-transporter 1 (SGLT1) is enhanced by supplementation of the diet of weaning piglets with artificial sweeteners
Authors: Moran Andrew W. , Al-Rammahi Miran A. , Arora Daleep K. , Batchelor Daniel J. , Coulter Erin A. , Daly Kristian , Ionescu Catherine , Bravo David , Shirazi-Beechey Soraya P.
Published: March 2010

In an intensive livestock production, a shorter suckling period allows more piglets to be born. However, this practice leads to a number of disorders including nutrient malabsorption, resulting in diarrhoea, malnutrition and dehydration. A number of strategies have been proposed to overcome weaning problems. Artificial sweeteners, routinely included in piglets' diet, were thought to enhance feed palatability. However, it is shown in rodent models that when included in the diet, they enhance the expression of Na+/glucose co-transporter (SGLT1) and the capacity of the gut to absorb glucose. Here, we show that supplementation of piglets' feed with a combination of artificial sweeteners saccharin and neohesperidin dihydrochalcone enhances the expression of SGLT1 and intestinal glucose transport function. Artificial sweeteners are known to act on the intestinal sweet taste receptor T1R2/T1R3 and its partner G-protein, gustducin, to activate pathways leading to SGLT1 up-regulation. Here, we demonstrate that T1R2, T1R3 and gustducin are expressed together in the enteroendocrine cells of piglet intestine. Furthermore, gut hormones secreted by the endocrine cells in response to dietary carbohydrates, glucagon-like peptides (GLP)-1, GLP-2 and glucose-dependent insulinotrophic peptide (GIP), are co-expressed with type 1 G-protein-coupled receptors (T1R) and gustducin, indicating that L- and K-enteroendocrine cells express these taste elements. In a fewer endocrine cells, T1R are also co-expressed with serotonin. Lactisole, an inhibitor of human T1R3, had no inhibitory effect on sweetener-induced SGLT1 up-regulation in piglet intestine. A better understanding of the mechanism(s) involved in sweetener up-regulation of SGLT1 will allow the identification of nutritional targets with implications for the prevention of weaning-related malabsorption.
Refugees, Land Reclamation, and Militarized Landscapes in Wartime China: Huanglongshan, Shaanxi, 1937–45
Authors: Muscolino Micah S.
Published: March 2010

This article investigates relationships between refugee flight and environmental change during the Sino-Japanese War of 1937–45 through a study of land reclamation projects in Shaanxi's Huanglongshan region. During the conflict with Japan, China's Nationalist government resettled thousands of refugees who fled war-induced natural disasters in Henan to Huanglongshan to reclaim uncultivated wastelands. Land reclamation reflected an ongoing militarization of China's environment, as political leaders looked to land reclamation to provide relief for refugees, further economic mobilization by exploiting untapped natural resources, and foster an ethos of dedication and self-sacrifice for the nation. Unrestrained land clearance decimated forests that had returned to Huanglongshan's hillsides since its abandonment during the rebellions of the late Qing. By compelling displaced people to cultivate marginal lands, war also threatened the health of refugees by exposing them to endemic disease. Yet the militarizing logic that motivated these reclamation initiatives continued to reshape China's natural landscape long after the Sino-Japanese War ended.
Structural sensitivity of the secondary instability in the wake of a circular cylinder
Authors: GIANNETTI FLAVIO , CAMARRI SIMONE , LUCHINI PAOLO
Published: March 2010

The sensitivity of the three-dimensional secondary instability of a circular-cylinder wake to a structural perturbation of the associated linear equations is investigated. In particular, for a given flow condition, the region of maximum coupling between the velocity components is localized by using the most unstable Floquet mode and its adjoint mode. The variation of this region in time is also found by considering a structural perturbation which is impulsively applied in time at a given phase of the vortex-shedding process. The analysis is carried out for both mode A and mode B types of transition in the wake of a circular cylinder using a finite-difference code. The resulting regions identified as the core of the instability are in full agreement with the results reported in the literature and with the a posteriori checks documented here.
Interaction between a cavitation bubble and shear flow
Authors: DABIRI SADEGH , SIRIGNANO WILLIAM A. , JOSEPH DANIEL D.
Published: March 2010

The deformation of a cavitation bubble in shear and extensional flows is studied numerically. The Navier–Stokes equations are solved to observe the three-dimensional behaviour of the bubble as it grows and collapses. During the collapse phase of the bubble, two re-entrant jets are observed on two sides of the bubble. The re-entrant jets are not the result of interaction with a solid wall or free surface; rather, they are formed due to interaction of the bubble with the background flow. Effects of the viscosity, surface tension and shear rate on the formation and strength of re-entrant jets are investigated. Re-entrant jets with enough strength break up the bubble into smaller bubbles. Post-processing and analysis of the results are done to cast the disturbance by the bubble on the liquid velocity field in terms of spherical harmonics. It is found that quadrupole moments are created in addition to the monopole source.
Characterization of a 14 kDa oocyst wall protein ofEimeria tenellaandE. acervulina
Authors: Eschenbacher K.-H. , Eggli P. , Wallach M. , Braun R.
Published: March 2010

We have extracted a protein of 14 kDa from purified oocyst walls of severalEimeriaspecies. Polyclonal antibodies were raised in rats against the 14 kDa proteins ofE. acervulinaandE. tenella. On immunoblots these antisera reacted in a highly specific manner with the homologous 14 kDa antigens, but not with heterologous antigens. In addition, specific binding of the two antisera to oocyst wall fragments ofE. acervulinaandE. tenellawas demonstrated by immunofluorescence. Partial amino-terminal sequences comprising 20 amino acid residues were obtained from the 14 kDa oocyst wall proteins ofE. acervulinaandE. tenella. They are characterized by an abundance of amino acids containing hydroxyl groups in their side chains (serine, tyrosine, threonine). Binding of the oocyst wall protein ofE. tenellaby peanut agglutinin indicates the presence of O-linked carbohydrates.
Adhesion and invasion of bovine endothelial cells byNeospora caninum
Authors: Hemphill A. , Gottstein B. , Kaufmann H.
Published: March 2010

Neospora caninumis a recently identified coccidian parasite which was, until 1988, misdiagnosed asToxoplasma gondii. It causes paralysis and death in dogs and neonatal mortality and abortion in cattle, sheep, goats and horses. The life-cycle ofNeosporahas not yet been elucidated. The only two stages identified so far are tissue cysts and intracellularly dividing tachyzoites. Very little is known about the biology of this species. We have set up a fluorescence-based adhesion/invasion assay in order to investigate the interaction ofN. caninumtachyzoites with bovine aorta endothelial (BAE) cellsin vitro. Treatment of both host cells and parasites with metabolic inhibitors determined the metabolic requirements for adhesion and invasion. Chemical and enzymatic modifications of parasite and endothelial cell surfaces were used in order to obtain information on the nature of cell surface components responsible for the interaction between parasite and host. Electron microscopical investigations defined the ultrastructural characteristics of the adhesion and invasion process, and provided information on the intracellular development of the parasites.