bluuebunny/crossref_metadata_2025 huggingface dataset:
Turbulent shear‐layer scaling in the limit of infinite Reynolds number derived from the unsteady equations of motion
Authors: Scheichl Bernhard , Kluwick Alfred
Published: September 2008

By considering the time‐mean motion, an asymptotic description of turbulent shear flows in the limit of high Reynolds numbers, conveniently carried out by adopting the method of matched asymptotic expansions, is inherently based on (a few) assumptions regarding the essential physical properties of the flow in the respective layer considered. Although this procedure has substantiated some classical results, as, for instance, the logarithmic law of the wall, it is, nevertheless, not completely satisfactory from a rational point of view: for this reason, we first demonstrate that a rigorous application of the matching principle alone is not capable of deducing the aforementioned wall law in the case of boundary layer flows by taking into account the widely accepted presumption of the so‐called ‘inviscid’ nature of the fully turbulent main portion of the shear layer. Therefore, to some extent, the usual approaches turn out to be incomplete, for (i) the motivation for the assumptions commonly employed seems not stringent and, unfortunately, (ii) are, strictly speaking, insufficient for developing a complete asymptotic theory. To be more precise, assumptions that are usually expressed by dimensional considerations can not adequately enter the matching conditions derived from the non‐dimensional form of the governing equations, which, however, is required for an asymptotic analysis. Consequently, the time‐mean scaling of the asymptotic structure of the flow is seen to result from an asymptotic analysis of the Navier–Stokes equations by, as the only fundamental assumption, considering an asymptotically slender turbulent shear layer. Amongst others, it is demonstrated briefly how a combination of multiple‐scales techniques and matched asymptotic expansions leads to the internal boundary layer splitting. Also, it is outlined how the latter also reflects the time‐mean characteristics of the flow, which have already been adopted successfully in former studies, e.g. by using rather conventional mixing length arguments. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A note on computational blood rheology
Authors: Sequeira Ad´elia , Janela João Paulo
Published: September 2008

We briefly present some numerical simulations for a generalized Newtonian model describing the shear‐thinning behavior of blood in a realistic 3D geometry. Results are compared with those obtained using the Newtonian model
Partly dissipative reaction diffusion systems: global attractors and determining modes
Authors: Shao Zhoude
Published: September 2008

This is an outline of a paper that extend the results of Hale and Raugel [2003] on regularity and determining nodes for solutions of dissipative evolutionary equations to abstract partly dissipative systems. The results are applicable to partly dissipative reaction diffusion systems. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Multiscale singularity trees
Authors: Somchaipeng K. , Sporring J. , Johansen P. , Kreiborg S.
Published: September 2008

We propose MultiScale Singularity Trees (MSSTs) as a structure to represent images, and we propose an algorithm for image comparison based on comparing MSSTs. The algorithm is tested on 3 public image databases and compared to 2 state‐of‐theart methods. We conclude that the computational complexity of our algorithm only allows for the comparison of small trees, and that the results of our method are comparable with state‐of‐the‐art using much fewer parameters for image representation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Convex separable minimization with box constraints
Authors: Stefanov Stefan M.
Published: September 2008

A minimization problem with convex separable objective function subject to a convex separable inequality constraint of the form “less than or equal to” and bounds on the variables (box constraints) is considered. Necessary and sufficient condition is proved for a feasible solution to be an optimal solution to this problem. An iterative algorithm of polynomial complexity for solving problems of the considered form is suggested and its convergence is proved. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Model order reduction for nonlinear problems in circuit simulation
Authors: Verhoeven A. , Voss T. , Astrid P. , ter Maten E.J.W. , Bechtold T.
Published: September 2008

Electrical circuits usually contain nonlinear components. Hence we are interested in MOR methods that can be applied to a system of nonlinear Differential‐Algebraic Equations (DAEs). In particular we consider the TPWL (Trajectory PieceWise Linear) and POD (Proper Orthogonal Decomposition) methods. While the first one fully exploits linearity, the last method needs modifications to become efficient in evaluation. We describe a particular technique based on Missing Point Estimation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Herpes simplex virus type 1 DNA is located within Alzheimer's disease amyloid plaques
Authors: Wozniak MA , Mee AP , Itzhaki RF
Published: September 2008

The brains of Alzheimer's disease sufferers are characterized by amyloid plaques and neurofibrillary tangles. However, the cause(s) of these features and those of the disease are unknown, in sporadic cases. We previously showed that herpes simplex virus type 1 is a strong risk factor for Alzheimer's disease when in the brains of possessors of the type 4 allele of the apolipoprotein E gene (APOE‐ε4), and that β‐amyloid, the main component of plaques, accumulates in herpes simplex virus type 1‐infected cell cultures and mouse brain. The present study aimed to elucidate the relationship of the virus to plaques by determining their proximity in human brain sections. We used in situ polymerase chain reaction to detect herpes simplex virus type 1 DNA, and immunohistochemistry or thioflavin S staining to detect amyloid plaques. We discovered a striking localization of herpes simplex virus type 1 DNA within plaques: in Alzheimer's disease brains, 90% of the plaques contained the viral DNA and 72% of the DNA was associated with plaques; in aged normal brains, which contain amyloid plaques at a lower frequency, 80% of plaques contained herpes simplex virus type 1 DNA but only 24% of the viral DNA was plaque‐associated (p < 0.001). We suggest that this is because in aged normal individuals, there is a lesser production and/or greater removal of β‐amyloid (Aβ), so that less of the viral DNA is seen to be associated with Aβ in the brain. Our present data, together with our finding of Aβ accumulation in herpes simplex virus type 1‐infected cells and mouse brain, suggest that this virus is a major cause of amyloid plaques and hence probably a significant aetiological factor in Alzheimer's disease. They point to the usage of antiviral agents to treat the disease and possibly of vaccination to prevent it. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Hepatocyte‐specific activation of NF‐κB does not aggravate chemical hepatocarcinogenesis in transgenic mice
Authors: Yau T‐O , Chan C‐F , Gee‐San Lam S , Cheung O‐F , Ching Y‐P , Jin D‐Y , Sham M‐H , Ng IOL
Published: September 2008

The NF‐κB signalling pathway plays important roles in liver organogenesis and carcinogenesis. Mouse embryos deficient in IKKβ die in mid‐gestation, due to excessive apoptosis of hepatoblasts. Although activation of the NF‐κB signalling pathway has been demonstrated in human hepatocellular carcinoma, the role of NF‐κB is controversial. Here, we have generated transgenic mice in which a constitutively active form of IKKβ was expressed in a hepatocyte‐specific manner. Using electrophoretic mobility shift assay, we documented increased NF‐κB activities and up‐regulated levels of NF‐κB downstream target genes, Bcl‐xL and STAT5, in the transgenic mouse livers. These results confirmed that the NF‐κB pathway was activated in the livers of the transgenic mice. However, there was no significant difference in tumour formation between transgenic and wild‐type mice up to an age of 50 weeks. When we treated the transgenic mice with the chemical carcinogen diethylnitrosamine (DEN), we observed no significant differences in the incidence and size of liver tumours formed in these mice with and without DEN treatment at 35 weeks of age, suggesting that the activated NF‐κB pathway in the livers of the transgenic mice did not enhance hepatocarcinogenesis. Interestingly, some of the transient transgenic embryos (E12.5) had abnormal excessive accumulation of nucleated red blood cells in their developing livers. In summary, NF‐κB activation in hepatocytes did not significantly affect chemical hepatocarcinogenesis. In addition, the TTR/IKKCA transgenic mice may serve as a useful model for studying the role of NF‐κB activation in hepatocarcinogenesis as well as inflammatory and metabolic diseases. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Frequency and clinical features of the JAK2 V617F mutation in pediatric patients with sporadic essential thrombocythemia
Authors: Nakatani Takuya , Imamura Toshihiko , Ishida Hiroyuki , Wakaizumi Katsuji , Yamamoto Tohru , Otabe Osamu , Ishigami Tsuyoshi , Adachi Souichi , Morimoto Akira
Published: September 2008

Background

Pediatric essential thrombocythemia (ET) is a rare and heterogenous disease entity. While several recent studies have focused on the role of the JAK2 V617F mutation in pediatric ET, the frequency of pediatric ET cases with this mutation and the associated clinical features remain unclear.

Procedure

We examined six childhood cases who had been diagnosed with ET according to WHO criteria (onset age: 0.2–14 years) for the presence of the JAK2 V617F mutation, MPLW515L mutation and JAK2 exon 12 mutations. Two sensitive PCR‐based methods were used for the JAK2 V617F genotyping. We also examined the expression of polycythemia rubra vera‐1 (PRV‐1), which is a diagnostic marker for clonal ET.

Results

We found that three of the six cases had the JAK2 V617F mutation and that all six cases expressed PRV‐1 in their peripheral granulocytes. Neither MPL W515L mutation nor JAK2 exon 12 mutations was detected in the patients without JAK2 V617F mutation. The two patients who developed thrombocythemia during infancy were JAK2 V617F‐negative.

Conclusions

These findings suggest that the JAK2 V617F mutation is not rare in childhood sporadic ET cases, and that these cases might be older and myeloproliferative features. Pediatr Blood Cancer 2008;51:802–805. © 2008 Wiley‐Liss, Inc.
Identification of a novel mutation in DKC1 in dyskeratosis congenita
Authors: Kurnikova Maria , Shagina Irina , Khachatryan Lilia , Schagina Olga , Maschan Mikchail , Shagin Dmitriy
Published: September 2008

Dyskeratosis congenita (DC) is a rare congenital syndrome characterized by the triad of reticular skin pigmentation, nail dystrophy and mucosal leukoplakia, and the predisposition to bone marrow failure and malignancy. DC is genetically heterogeneous and X‐linked and autosomal forms of the disease exist. Here, we report the clinical description and mutation analysis of a Russian family with X‐linked DC. A novel mutation in DKC1 raised de novo in the maternal grandmother's gamete was found; this mutation is a 2 bp inversion in exon 3: NM_001363:c.166_167invCT (Leu56Ser). Pediatr Blood Cancer 2009;52:135–137. © 2008 Wiley‐Liss, Inc.
Using genetic algorithms to select most predictive protein features
Authors: Kernytsky Andrew , Rost Burkhard
Published: September 2008

Many important characteristics of proteins such as biochemical activity and subcellular localization present a challenge to machine‐learning methods: it is often difficult to encode the appropriate input features at the residue level for the purpose of making a prediction for the entire protein. The problem is usually that the biophysics of the connection between a machine‐learning method's input (sequence feature) and its output (observed phenomenon to be predicted) remains unknown; in other words, we may only know that a certain protein is an enzyme (output) without knowing which region may contain the active site residues (input). The goal then becomes to dissect a protein into a vast set of sequence‐derived features and to correlate those features with the desired output. We introduce a framework that begins with a set of global sequence features and then vastly expands the feature space by generically encoding the coexistence of residue‐based features. It is this combination of individual features, that is the step from the fractions ofserineandburied(input space 20 + 2) to the fraction ofburied serine(input space 20 ☆ 2) that implicitly shifts the search space from global feature inputs to features that can capture very local evidence such as a the individual residues of a catalytic triad. The vast feature space created is explored by a genetic algorithm (GA) paired with neural networks and support vector machines. We find that the GA is critical for selecting combinations of features that are neither too general resulting in poor performance, nor too specific, leading to overtraining. The final framework manages to effectively sample a feature space that is far too large for exhaustive enumeration. We demonstrate the power of the concept by applying it to prediction of protein enzymatic activity. Proteins 2009. © 2008 Wiley‐Liss, Inc.
Structural basis for sugar recognition, including the Tn carcinoma antigen, by the lectin SNA‐II from Sambucus nigra
Authors: Maveyraud Laurent , Niwa Hideaki , Guillet Valérie , Svergun Dmitri I. , Konarev Peter V. , Palmer Rex A. , Peumans Willy J. , Rougé Pierre , Van Damme Els J. M. , Reynolds Colin D. , Mourey Lionel
Published: September 2008

Bark of elderberry (Sambucus nigra) contains a galactose (Gal)/N‐acetylgalactosamine (GalNAc)‐specific lectin (SNA‐II) corresponding to slightly truncated B‐chains of a genuine Type‐II ribosome‐inactivating protein (Type‐II RIPs, SNA‐V), found in the same species. The three‐dimensional X‐ray structure of SNA‐II has been determined in two distinct crystal forms, hexagonal and tetragonal, at 1.90 Å and 1.35 Å, respectively. In both crystal forms, the SNA‐II molecule folds into two linked ββ‐trefoil domains, with an overall conformation similar to that of the B‐chains of ricin and other Type‐II RIPs. Glycosylation is observed at four sites along the polypeptide chain, accounting for 14 saccharide units. The high‐resolution structures of SNA‐II in complex with Gal and five Gal‐related saccharides (GalNAc, lactose, αα1‐methylgalactose, fucose, and the carcinoma‐specific Tn antigen) were determined at 1.55 Å resolution or better. Binding is observed in two saccharide‐binding sites for most of the sugars: a conserved aspartate residue interacts simultaneously with the O3 and O4 atoms of saccharides. In one of the binding sites, additional interactions with the protein involve the O6 atom. Analytical gel filtration, small angle X‐ray scattering studies and crystal packing analysis indicate that, although some oligomeric species are present, the monomeric species predominate in solution. Proteins 2009. © 2008 Wiley‐Liss, Inc.
Sampling efficiency in explicit and implicit membrane environments studied by peptide folding simulations
Authors: Ulmschneider Jakob P. , Ulmschneider Martin B.
Published: September 2008

Efficient exploration of the conformational space of peptides embedded in biological membranes is vital to extract converged thermodynamic and kinetic data from simulation studies. Recently developed implicit membrane models promise vast increases in sampling efficiency compared to explicit membrane simulations, allowing for ab initio structure prediction and functional studies. In this study, a previously developed implicit membrane model, based on the generalized Born method, is compared to an explicit di‐palmitoyl‐phosphatidyl‐choline lipid bilayer and an octane slab membrane mimic. The complete folding process of a synthetic 16‐residue peptide is compared using these three setups. Since the comparison requires the entire folding pathway to be captured, individual simulations ranged up to 3 μs of MD. A quantitative sampling comparison using a wide range of performance metrics reveals that the implicit membrane model is at least 2 orders of magnitude more efficient than the simplest explicit setups. Proteins 2009. © 2008 Wiley‐Liss, Inc.
Interactions of different inhibitors with active‐site aspartyl residues of HIV‐1 protease and possible relevance to pepsin
Authors: Sayer Jane M. , Louis John M.
Published: September 2008

The importance of the active site region aspartyl residues 25 and 29 of the mature HIV‐1 protease (PR) for the binding of five clinical and three experimental protease inhibitors [symmetric cyclic urea inhibitor DMP323, nonhydrolyzable substrate analog (RPB) and the generic aspartic protease inhibitor acetyl‐pepstatin (Ac‐PEP)] was assessed by differential scanning calorimetry. ΔTm values, defined as the difference in Tm for a given protein in the presence and absence of inhibitor, for PR with DRV, ATV, SQV, RTV, APV, DMP323, RPB, and Ac‐PEP are 22.4, 20.8, 19.3, 15.6, 14.3, 14.7, 8.7, and 6.5°C, respectively. Binding of APV and Ac‐PEP is most sensitive to the D25N mutation, as shown by ΔTm ratios [ΔTm(PR)/ΔTm(PRD25N)] of 35.8 and 16.3, respectively, whereas binding of DMP323 and RPB (ΔTm ratios of 1–2) is least affected. Binding of the substrate‐like inhibitors RPB and Ac‐PEP is nearly abolished (ΔTm(PR)/ΔTm(PRD29N) ≥ 44) by the D29N mutation, whereas this mutation only moderately affects binding of the smaller inhibitors (ΔTm ratios of 1.4–2.2). Of the nine FDA‐approved clinical HIV‐1 protease inhibitors screened, APV, RTV, and DRV competitively inhibit porcine pepsin with Ki values of 0.3, 0.6, and 2.14 μM, respectively. DSC results were consistent with this relatively weak binding of APV (ΔTm 2.7°C) compared with the tight binding of Ac‐PEP (ΔTm ≥ 17°C). Comparison of superimposed structures of the PR/APV complex with those of PR/Ac‐PEP and pepsin/pepstatin A complexes suggests a role for Asp215, Asp32, and Ser219 in pepsin, equivalent to Asp25, Asp25′, and Asp29 in PR in the binding and stabilization of the pepsin/APV complex. Proteins 2009. Published 2008 Wiley‐Liss, Inc.
Thermoelectric power of nanoscale MnSi1.7 films
Authors: Hou Q. R. , Zhao W. , Chen Y. B. , He Y. J.
Published: September 2008

MnSi1.7 bulk materials and thin films are usually p‐type. When the thickness of MnSi1.7 film is reduced to nanoscale, however, the carriers are p‐type around room temperature and transform to n‐type at high temperatures. The thermoelectric powers at room temperature and 633 K are 128 and –340 μV/K, respectively. A n‐type MnSi1.7 film with a thickness of about 14 nm is prepared. The thermoelectric power reaches to –967 μV/K at 483 K. From these data, the energy band gap is estimated as 0.93 eV, which is consistent with that obtained from the temperature dependence of the electrical resistivity measurements. The large thermoelectric power may be due to the increase in the electronic density of states and energy band gap in low‐dimensional semiconductors or hetero‐structures being formed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Phase‐change memories
Authors: Lacaita Andrea L. , Wouters Dirk J.
Published: September 2008

Phase Change Materials are adopted in optical data storage and are currently evolving to become the active material of a new viable non‐volatile memory technology which is expected to eventually replace no‐longer‐scaling Flash memory technologies. Phase‐Change Memories store their information as the material phase of a chalcogenide metal alloy (high‐resistive amorphous, respectively low‐resistive crystalline phase), the most important compound being Ge2Sb2Te5(GST). To give insight in this important evolution, the paper describes the different aspects of Phase‐Change Memories. It starts from basic operation principle and fundamental material properties (Sections 2 and 3). Vital to their operation are not only the vitrification and crystallization properties of the chalcogenide material, but also the phenomenon of electronic threshold switching enabling low‐voltage Joule heating in the amorphous phase. Understanding and modeling of these effects are described in Section 4. Cell concepts and integration technology aspects, including optimization schemes aimed at reducing the program current are covered in Section 5. Finally, the excellent reliability and scaling properties of Phase‐Change Memories are discussed in Sections 6 and 7. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Single dot spectroscopy on InAs/GaAs piezoelectric quantum dots
Authors: Dialynas G. E. , Chatzidimitriou N. , Kalliakos S. , Tsintzos S. , Savvidis P. G. , Hatzopoulos Z. , Pelekanos N. T.
Published: September 2008

We report on single dot spectroscopy of InAs/GaAs quantum dots grown by molecular beam epitaxy along the polar (211)B direction. Unlike the (001) dots, in the (211)B dots we have systematically observed large blue shifts of the biexciton lines with respect to the excitonic ones. This is attributed to the strong piezoelectric field present inside the polar dots. In order to better interpret our results, we performed preliminary photoluminesence studies under the influence of an external electric field, which showed large Stark shifts of the quantum dot ensemble. From the analysis of these results, we deduced that the piezoelectric field in the (211)B InAs/GaAs quantum dots is as large as 800kV/cm, which is consistent with the large anti‐binding energies of bi‐excitons observed in this system. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Efficient infrared emission from patterned thin metal films on a Si photonic crystal
Authors: Theodoni P. , Vamvakas V. Em. , Speliotis Th. , Chatzichristidi M. , Bayiati P. , Raptis I. , Papanikolaou N.
Published: September 2008

We study the infrared optical response of periodically patterned thin metal films on a Si photonic crystal using Fourier‐transform infrared spectroscopy and full electrodynamic calculations. Thin metallic films on top of Si substrate were patterned using optical lithography; furthermore the Si substrate was etched, using the metal as a mask. The structures have a narrow band absorption spectrum for wavelengths close to the lattice constant of the patterning. Both Al and Au films gave similar infrared response. Our results can be explained by multiple scattering electrodynamic simulations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
All‐organic optocouplers based on polymer light‐emitting diodes and photodetectors
Authors: Stathopoulos N. A. , Palilis L. C. , Vasilopoulou M. , Botsialas A. , Falaras P. , Argitis P.
Published: September 2008

In this work, we demonstrate all organic flexible polymeric optocouplers by utilizing a donor‐acceptor bulk heterojunction polymer photodetector (PD) as the output unit and a polymer light‐emitting diode (PLED) as the input unit. The input unit is a single‐layer PLED on a glass or a plastic (PET) substrate utilizing a green emitting polyfluorene‐benzothiadiazole copolymer in the active layer. The output unit is a single‐layer PD on a glass substrate utilizing a P3HT:PCBM(1:1 by weight) blend, where P3HT is regioregular poly(3‐hexylthiophene) and PCBM is (6,6)‐phenyl‐C61‐butyric acid methyl ester. The electroluminescence spectrum of the PLED peaks at 530 nm and covers a spectral range that coincides quite well with the PD absorption spectrum (between 450 and 650 nm). The current density transfer ratio reaches 0.012% for an optocoupler that operates at 0 V and 15 V for the PD and PLED, respectively. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
New modes of FFT impedance spectroscopy applied to semiconductor pore etching and materials characterization
Authors: Carstensen J. , Foca E. , Keipert S. , Föll H. , Leisner M. , Cojocaru A.
Published: September 2008

A systematic approach for the application of fast Fourier transform (FFT) impedance spectroscopy to semiconductor photo‐electrochemistry is given. In particular, photo‐impedance spectroscopy in two novel modes is used in conjunction with conventional current–voltage impedance spectroscopy, and applied to some aspects of pore etching in InP and Si as well as to the characterization of multicrystalline Si or other solar cell material. The technique, applicable in situ with high time resolution, employs optimized hardware and software, extensive mathematical modeling of carrier transport, and the numerical implementation of fast parameter extraction algorithms. The complete system with a fully integrated impedance spectrometer delivers a wealth of new data including key parameters of pore etching. Examples given include the in situ tracking of the fast switch‐over between pore growth modes in InP as well as following a pore etching process over long time scales in Si. FFT impedance spectroscopy in the novel back side illumination mode, in combination with the conventional mode, allows not only some active control of macropore etching in n‐type Si by supplying crucial real‐time data like the valence of the dissolution process and the pore depth, but also provides new fundamental insights into the electrochemical processes occurring at the (porous) electrode. FFT photo‐impedance spectroscopy in the front side illumination mode used in conjunction with a scanned laser beam allows fast local measurements of all semiconductor parameters relevant for solar cell applications, like doping concentration, minority carrier lifetime, diffusion constant, or surface recombination velocity with high spatial resolution; this is demonstrated for large multicrystalline Si wafers. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth and electrical characterization of thin conductive Au nanoparticle chains on oxidized Si substrates between electrodes for sensor applications
Authors: Zoy A. , Nassiopoulou A. G.
Published: September 2008

Citrate‐stabilized colloid Au nanoparticles with an average diameter of 40 nm have been assembled in nanoparticle chains between microelectrodes on oxidized V‐groove‐etched Si surfaces by the technique of dielectrophoresis. Chain formation was investigated as a function of electrodes configuration and the amplitude and frequency of the applied electric field. Conductive thin (∼100‐200 nm thick) single and multiple Au nanoparticle chains, with a length in the range of 1 to 10 µm, were preferentially formed on V‐groove lines between the electrodes. Electrical characterization by temperature‐dependent current‐voltage measurements showed that the Au nanoparticle chains exhibit ohmic conductivity with a resistance in the range of few Ω to few kΩ, depending on the distance between electrodes and the configuration of the Au nanoparticles in the structure. On the contrary, 5 nm diameter tiopronin‐stabilized Au NPs chains exhibited nearest‐ neighbour hopping conductivity and non‐linear thermally‐activated I‐V characteristics. We also tested nanogap formation in the chains by an applied pulse of electric current, in view of applying the nanoparticle chains in the tracing of chemical or biological molecules. The conductive thin Au nanoparticle chains, with or without nanogaps, are interesting building blocks for different sensor devices. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theoretical study of electronic spectra of [Pt3(μ‐CO)3(CO)3] (n = 3–5) complexes
Authors: Mendizabal Fernando , Burgos Darwin , Olea‐Azar Claudio
Published: September 2008

The platinum‐platinum attraction and the spectroscopic properties of [Pt3(μ‐CO)3(CO)3] (n = 3–5) were studied at the PBE level. Theoretical calculations are in agreement with experimental geometries. The absorption spectra of these platinum complexes were calculated by the single excitation time‐dependent (TD) density functional method. All complexes showed MLCT transitions interrelated with the intertriangular complexes. The values obtained at the PBE level are in agreement with the experimental color range. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Molecular parameters of tetraatomic carbonyls X2CO and XYCO (X, Y = H, F, Cl) in the ground and lowest excited electronic states, part 1: A test ofab initiomethods
Authors: Bokarev Sergey I. , Dolgov Evgeny K. , Bataev Vadim A. , Godunov Igor A.
Published: September 2008

Geometrical parameters of tetraatomic carbonyl molecules X2CO and XYCO (X, Y = H, F, Cl) in the ground (S0) and lowest excited singlet (S1) and triplet (T1) electronic states as well as values of barriers to inversion inS1andT1states andS1←S0andT1←S0adiabatic transition energies were systematically investigated by means of various quantum‐chemical techniques. The following methods were tested: HF, MP2, CIS, CISD, CCSD, EOM‐CCSD, CCSD(T), CR‐EOM‐CCSD(T), CASSCF, MR‐MP2, CASPT2, CASPT3, NEVPT2, MR‐CISD, and MR‐AQCC within cc‐pVTZ and cc‐pVQZ basis sets. The accuracy of quantum‐chemical methods was estimated in comparison with experimental data and rather accurate structures of excited electronic states were obtained. MP2 and CASPT2 methods appeared to be the most efficient and CCSD(T), CR‐EOM‐CCSD(T), and MR‐AQCC the most accurate. It was found that at equilibrium all the molecules under study are nonplanar inS1andT1electronic states with CO out‐of‐plane angle ranging from 34° (H2CO,S1) to 52° (F2CO,T1), and height of barrier to inversion varying from 300 (H2CO,S1) to 11,000 (F2CO,T1) cm−1. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Management of diabetes in pregnancy
Authors: Adamson Karen A. , McKnight John A.
Published: September 2008

Pregnancy in women with diabetes is associated with significantly increased risks. The authors look at the factors that influence outcome and how these can be addressed through advanced planning. Copyright © 2008 Wiley Interface Ltd
Tribophyiscal scaling effects in friction and wear of polymers on small‐ and large‐scale tests
Authors: Samyn P. , Schoukens G.
Published: September 2008

Coefficients of friction and wear rates for polyacetal and polytetrafluoroethylene are measured on small‐scale cylinder‐on‐plate tests and large‐scale flat‐on‐flat tests. Three models for extrapolation between small‐ and large‐scale test results, which are based on experimental parameters, are presented: (i) one single mechanical parameter (normal load), (ii) the contact‐pressure–sliding‐velocity model (temperature limit), and (iii) a macroscopic geometry model. The last model is most extensively evaluated and considers thermal effects, sample geometry and contact conditions. After correction for the thermal sliding regime and viscoelastic deformation, the coefficients of friction can be extrapolated while the wear rates are more sensitive to the contact situation. High‐temperature tests on small scale are not representative for high‐load tests on large scale. Besides mechanical effects such as stress concentrations and debris mobility, variations in polymer structure under sliding (formation of rigid amorphous phase) and chemical interactions (wear debris polymerisation) also change with testing scale. The latter effects are explicitly illustrated from spectroscopic measurements on the worn surfaces. Copyright © 2008 John Wiley & Sons, Ltd.
Nonparametric Estimation of Standard Errors in Covariance Analysis Using the Infinitesimal Jackknife
Authors: Jennrich Robert I.
Published: September 2008

The infinitesimal jackknife provides a simple general method for estimating standard errors in covariance structure analysis. Beyond its simplicity and generality what makes the infinitesimal jackknife method attractive is that essentially no assumptions are required to produce consistent standard error estimates, not even the requirement that the population sampled has the covariance structure assumed. Commonly used covariance structure analysis software uses parametric methods for estimating parameters and standard errors. When the population sampled has the covariance structure assumed, but fails to have the distributional form assumed, the parameter estimates usually remain consistent, but the standard error estimates do not. This has motivated the introduction of a variety of nonparametric standard error estimates that are consistent when the population sampled fails to have the distributional form assumed. The only distributional assumption these require is that the covariance structure be correctly specified. As noted, even this assumption is not required for the infinitesimal jackknife. The relation between the infinitesimal jackknife and other nonparametric standard error estimators is discussed. An advantage of the infinitesimal jackknife over the jackknife and the bootstrap is that it requires only one analysis to produce standard error estimates rather than one for every jackknife or bootstrap sample.
Motor Nerve Transfers to Restore Extrinsic Median Nerve Function: Case Report
Authors: Hsiao Eugene C. , Fox Ida K. , Tung Thomas H. , Mackinnon Susan E.
Published: September 2008

Active pronation is important for many activities of daily living. Loss of median nerve function including pronation is a rare sequela of humerus fracture. Tendon transfers to restore pronation are reserved for the obstetrical brachial plexus palsy patient. Transfer of expendable motor nerves is a treatment modality that can be used to restore active pronation. Nerve transfers are advantageous in that they do not require prolonged immobilization postoperatively, avoid operating within the zone of injury, reinnervate muscles in their native location prior to degeneration of the motor end plates, and result in minimal donor deficit. We report a case of lost median nerve function after a humerus fracture. Pronation was restored with transfer of the extensor carpi radialis brevis branch of the radial nerve to the pronator teres branch of the median nerve. Anterior interosseous nerve function was restored with transfer of the supinator branch to the anterior interosseous nerve. Clinically evident motor function was seen at 4 months postoperatively and continued to improve for the following 18 months. The patient has 4+/5 pronator teres, 4+/5 flexor pollicis longus, and 4-/5 index finger flexor digitorum profundus function. The transfer of the extensor carpi radialis brevis branch of the radial nerve to the pronator teres and supinator branch of the radial nerve to the anterior interosseous nerve is a novel, previously unreported method to restore extrinsic median nerve function.
Tumoral Calcinosis–or is it? A Case Report and Review
Authors: Hammert Warren C. , Lindsay Leroy R.
Published: September 2008

Tumoral calcinosis is an uncommon lesion, composed of ectopic calcified tissue, most commonly seen in the large joints of the hips, shoulders, and elbows, but may involve the hand and wrist. Patients will often present with localized swelling and reduced mobility around the involved joints. Pain is inconsistent when presenting in the hands or wrists, but the lesions may interfere with daily activities. Multiple variations of the process have been described, ranging from those with no definable etiology (primary), to those associated with disorders (secondary) such as renal insufficiency, hyperparathyroidism, or hypervitaminosis D. The original description of tumoral calcinosis, however, is the familial or hereditary type. Treatment of this process involves optimizing the underlying physiology and complete surgical excision for symptomatic cases.
End-of-Skin Grafts in Syndactyly Release: Description of a New Flap for Web Space Resurfacing and Primary Closure of Finger Defects
Authors: Sharma Ramesh Kumar , Tuli Puneet , Makkar Surinder Singh , Parashar Atul
Published: September 2008

Treatment of syndactyly necessitates creation of neo-web space and separation of fingers. Traditionally, this has been done by use of flaps taken from the dorsum; the resultant raw areas thus created have been managed by use of skin grafts. The classical teaching has been that the separated fingers will need skin graft as primary closure is not possible. The skin grafts have a tendency to contract and lead to finger flexion contractures and “creep” of the web space. We describe a flap based upon subcutaneous tissue in the web that is moved in a V–Y fashion to resurface the neo-web. The flap donor site can easily be closed primarily. The fingers are then separated; the subcutaneous fat is carefully removed from the finger flaps under magnification to allow primary closure of the finger defects. It has been possible to primarily close the donor site and fingers in all the patients. The procedure has been used in seven patients with 14 web releases. The age varied between 10 months to 3 years. The V–Y advancement flap based upon the subcutaneous pedicle in the region of the web allows adequate creation of a new web space. The careful de-fattening of skin flaps allows the separated fingers to be closed primarily.
Effect of Conjugated Linoleic Acid and Fatty Acid Positional Distribution on Physicochemical Properties of Structured Lipids
Authors: Rocha‐Uribe A. , Hernandez E.
Published: September 2008

Specific structured lipids (SSL), previously produced by enzymatic acidolysis of coconut oil with different levels of conjugated linoleic acid (CLA) as fatty acid (FA), using a sn‐1, 3 specific immobilized lipase, were used to prepare randomized structured lipids (RSL). A fraction of each SSL was subjected to chemical interesterification with sodium methoxide catalyst in order to modify the FA positional distribution and produce the corresponding RSL. Both families of structured lipids (SL) containing CLA were physicochemically characterized. Then, analysis of variance (ANOVA) was performed to evaluate the effects of CLA content (10, 20, 30 and 40%) and FA positional distribution (specific and randomized) on physicochemical properties of SL. Free fatty acids (FFA), peroxide value (PV) and p‐anisidine value (p‐AV) were not significantly affected by either CLA content or distribution. As expected, the iodine value (IV) and saponification value (SV) were influenced by CLA content but not by FA positional distribution, while oxidative stability index (OSI) was affected by both factors. Dropping point (DP), cloud point (CP) and solid fat content (SFC) decreased with the increase of CLA, while viscosity increased with the level of CLA. The FA positional distribution affected practically all the evaluated physical properties of SL, except CP and DP.
Pubertal timing and its link to behavioral and emotional problems among ‘at‐risk’ African American adolescent girls
Authors: Carter Rona , Jaccard James , Silverman Wendy K. , Pina Armando A.
Published: September 2008

Using an ‘at‐risk’ sample of African American girls, the present study examined the link between girls' retrospective reports of pubertal timing, girls' perceived relative pubertal timing, and their behavioral and emotional problems as rated by the girls themselves (N = 102; 11–17 years), as well as teachers and parents. Structural equation modeling results indicated that the girls' retrospective reports of menarche were significantly related to their perceived relative menarche, whereas the girls' retrospective reports of development of their breasts were not related to their perceived relative development of breasts. Girls who perceived their breasts developing early relative to their peers were more likely to engage in delinquent behaviors according to teacher report. Significant effects of teacher reported adolescent internalizing problems also were found for girls who retrospectively reported either early or late development of breasts. The study's findings underscore the importance of teasing apart the effects of different indicators of girls' pubertal development on psychosocial adjustment and including teachers' reports of girls' emotional and behavioral problems, particularly among girls with the additional risks associated with residing in an economically disadvantaged urban setting.
Time Out: An Analysis
Authors: Dillon Kimberly Anne
Published: September 2008

ENSURING PATIENT SAFETY in the OR includes performing a time out to help prevent wrong site surgery. The circulating nurse, in the role of patient advocate, usually is the OR team member who initiates the time out.

A CORRECTLY PERFORMED TIME OUT includes verifying the correct patient; procedure; site (eg, organ, limb, vertebral level, laterality); surgeon; and position, as well as that proper equipment, instrumentation, and implants are available. Unacceptable time outs can be categorized as borderline, contrary, related, illegitimate, or invented cases.

HEALTH CARE SYSTEMS should follow the Joint Commission's Universal Protocol and should have tools in place to ensure that patients will undergo correct site surgery. AORN J 88 (September 2008) 437–442. © AORN, Inc, 2008.
Laparoscopic‐Assisted Colon Surgery
Authors: Hageman Danny , Caillet Victoria , Kostohryz Jeff , Madick Sue
Published: September 2008

LAPAROSCOPIC‐ASSISTED colon surgery is a safe alternative to conventional open colectomy. Using the laparoscopic approach, the surgeon uses tools through port sites to mobilize the section of colon to be removed, avoiding a large laparotomy incision. Usually, two to three 5‐mm port sites and one 10‐mm or 12‐mm port site are created.

ALTHOUGH THIS PROCEDURE often requires a small incision to remove the diseased portion of the colon, the incision is much smaller, causing less postoperative pain and shortening the hospital stay. This leads to a faster return to activities of daily living for the patient. AORN J 88 (September 2008) 403–412. © AORN, Inc, 2008.
Evaluating a Case Study Using Bloom's Taxonomy of Education
Authors: Larkin Brenda G. , Burton Karen J.
Published: September 2008

THE JOINT COMMISSION recognizes effective communication among caregivers as an important factor for ensuring patient safety, especially at times when the patient's care is handed off from one caregiver or service to another.

THIS CASE STUDY reviews the course of treatment for one patient throughout the perioperative continuum, including the postoperative unit where a pre‐arrest situation developed.

A WORKSHOP USING BLOOM'S TAXONOMY of Educational Objectives enabled staff members to more clearly understand the patient's situation. It also allowed the participants to gain an increased understanding of significant data and has been strategic in preventing patient complications. AORN J 88 (September 2008) 390–402. © AORN, Inc, 2008.
Perioperative Nursing Competency
Authors: Stobinski James X.
Published: September 2008

OR MANAGERS FACE INCREASING pressure to ensure nursing competency.

SUBSPECIALTY EDUCATION programs provide a critical foundation upon which eventual clinical competency will be built, but the relationship between competency and clinical performance is not yet well understood.

A VARIETY OF PERIOPERATIVE nursing subspecialty programs are described in the literature. These programs were examined in the context of the theoretical connection between education, clinical experience, and nursing competency.AORN J88 (September 2008) 417–436. © AORN, Inc, 2008.
Young people making sense of pain: Cognitive appraisal, function, and pain in 8–16 year old children
Authors: Huguet Anna , Eccleston Christopher , Miró Jordi , Gauntlett‐Gilbert Jeremy
Published: September 2008

Recurrent pain is a common childhood problem which for some becomes chronic and is associated with severely impaired functioning. Relationships of psychological variables with impaired functioning have rarely been investigated in samples of children reporting pain in non‐clinical settings. The aim of this study was to examine the role of cognitive appraisal in the relationship between chronic pain and level of functioning in a normal school‐attending population of children who report pain as a common experience. Five hundred and sixty one schoolchildren aged between 8 and 16 years and their parents participated in a cross‐sectional interview and questionnaire study. Child functioning was measured in two ways: self‐reported quality of life, and self‐reported functional disability associated with pain. Results showed a consistent pattern across both specific measures of functioning used. Catastrophic appraisals of pain can explain partially the functional impairment found in a sample of normal schoolchildren with chronic pain. Positive expectations about ability, the responsibility to exert control over the pain, and the belief that medication and doctors will help to control the pain, were found to be protective of normal functioning in chronic pain. Cognitive factors were found to mediate but not moderate the relationship between pain and disability, and quality of life.
Painful or painless lower limb dysesthesias are highly predictive of peripheral neuropathy: Comparison of different diagnostic modalities
Authors: Scherens Andrea , Maier Christoph , Haussleiter Ida Sybille , Schwenkreis Peter , Vlckova‐Moravcova Eva , Baron Ralf , Sommer Claudia
Published: September 2008

Dysesthesias of the lower limbs are a common complaint of patients and may be indicative of peripheral neuropathy. Here we investigated the prevalence and type of neuropathy in patients presenting with this complaint and compared the diagnostic performance of different diagnostic modalities. Forty‐two patients were recruited prospectively and underwent a clinical examination, nerve conduction studies, quantitative sensory testing (QST), and skin biopsy at the dorsum of the foot. All patients had a correlate for their dysesthesias in at least one diagnostic modality. Most patients (>90%) had signs of small fiber loss or dysfunction. In about half of all patients large fibers were also affected. Nerve conduction studies were abnormal in 23/42 patients (54.8%). Cold or warm detection thresholds in QST were abnormal in 15/42 (35.7%) patients. Decreased intraepidermal nerve fiber density (IENFD) was found in 37 patients (88.1%), including some patients with normal QST findings. Nearly all patients with pathological QST had a reduced IENFD, indicating a high positive predictive value (93%) of QST in screening for reduced IENFD as correlate for neuropathy. Therefore in all patients with lower limb dysesthesias of unknown origin, the non‐invasive methods of NCS and QST should be used and potentially complemented by skin biopsy.
The primacy of mania: A reconsideration of mood disorders
Authors: Koukopoulos Athanasios , Ghaemi S. Nassir
Published: September 2008

In contemporary psychiatry, depression and mania are conceived as different entities. They may occur together, as in bipolar disorder, or they may occur separately, as in unipolar depression. This view is partly based on a narrow definition of mania and a rather broad definition of depression. Generally, depression is seen as more prominent, common, and problematic; while mania appears uncommon and treatment-responsive. We suggest a reversal: mania viewed broadly, not as simply episodic euphoria plus hyperactivity, but a wide range of excitatory behaviors; and depression seen more narrowly. Further, using pharmacological and clinical evidence, and in contrast to previous theories of mania interpreted as a flight from depression, we propose the primacy of mania hypothesis (PM): depression is a consequence of the excitatory processes of mania. If correct, current treatment of depressive illness needs revision. Rather than directly lifting mood with antidepressants, the aim would be to suppress manic-like excitation, with depression being secondarily prevented. Potential objections to, and empirical tests of, the PM hypothesis are discussed.