bluuebunny/crossref_metadata_2025 huggingface dataset:
BRAF mutation is a prognostic biomarker for colorectal liver metastasectomy
Authors: Teng Hao‐Wei , Huang Yu‐Chung , Lin Jen‐Kou , Chen Wei‐Shone , Lin Tzu‐Chen , Jiang Jeng‐Kai , Yen Chueh‐Chuan , Li Anna Fen‐Yau , Wang Hsei‐Wei , Chang Shih‐Ching , Lan Yuan‐Tzu , Lin Chun‐Chi , Wang Huann‐Sheng , Yang Shung‐Haur
Published: February 2012

Background and Objectives

In metastatic colorectal cancer, v‐Ki‐ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) is a predictive biomarker for anti‐epidermal growth factor receptor (EGFR) treatment and V‐raf murine sarcoma viral oncogene homolog B1 (BRAF) is a prognostic biomarker. We aimed to determine the impact of KRAS and BRAF mutation as determined from liver metastases specimens on overall survival (OS) in patients following colorectal liver metastasectomy.

Methods

Liver metastases specimens (n = 292) obtained from patients after liver metastasectomy were used to determine the KRAS/BRAF genotype. Associations between clinicopathological parameters and KRAS/BRAF genotype were identified by univariate and multivariate analyses using the Cox proportional hazards model. The impact of KRAS/BRAF genotype on survival was analyzed using the Kaplan–Meier method.

Results

The 5‐year survival rate of the cohort was 55.8%. The KRAS and BRAF mutation rates were 38.0 and 2.1%, respectively. BRAF genotype, but not KRAS, was found to be an independent prognostic biomarker (HR = 5.181, P = 0.002) after adjustment for other significant confounding clinicopathological variates: Number of liver metastases (HR = 1.983, P = 0.009), concomitant extrahepatic disease (HR = 1.858, P = 0.014), and surgical margin (HR = 3.241, P < 0.001). BRAF genotype was an independent prognostic biomarker in patients with liver metastases only after metastasectomy (HR = 6.245, P < 0.003).

Conclusions

BRAF mutation is an independent prognostic biomarker for colorectal liver metastasectomy. J. Surg. Oncol. 2012; 106:123–129. © 2012 Wiley Periodicals, Inc.
Cirrhotic cardiomyopathy and liver transplantation
Authors: Myers Robert P. , Lee Samuel S.
Published: February 2012

Myocardial contractility in cirrhosis is impaired, particularly under stressful situations, in a phenomenon termed cirrhotic cardiomyopathy. Impairment of the cardiac β-adrenergic receptor and its signaling function appears to be involved in the pathogenesis of this disorder. Additional mechanisms that may have a role include alterations in the physicochemical properties of the cardiomyocyte plasma membrane and abnormalities in circulating humoral factors, such as nitric oxide, carbon monoxide, and catecholamines. The widespread use of orthotopic liver transplantation (OLT) and its associated stresses on the cardiovascular system have highlighted this condition. Cardiac failure has emerged as an important cause of morbidity and mortality in the liver transplant recipient. Unfortunately, pre-OLT recognition of cirrhotic cardiomyopathy is suboptimal because of a lack of sensitive, noninvasive diagnostic tests. Similarly, the management of cirrhotic cardiomyopathy is largely empirical because of a paucity of existing literature. Although evidence suggests that cirrhotic cardiomyopathy may be reversible after OLT, the natural history of this condition warrants further investigation.
The Cauchy‐Kowalewski product for bicomplex holomorphic functions
Authors: De Bie H. , Struppa D. C. , Vajiac A. , Vajiac M. B.
Published: February 2012

In this paper we study the Cauchy‐Kowalewski extension of real analytic functions satisfying a system of differential equations connected to bicomplex analysis, and we use this extension to study the product in the space of bicomplex holomorphic functions. We also show how these ideas can be used to define a Fourier transform for bicomplex holomorphic functions.
Magnetic Fe3O4‐PS‐Polyacetylene Composite Microspheres Showing Chirality Derived From Helical Substituted Polyacetylene
Authors: Liu Dong , Zhang Ling , Li Mingkun , Yang Wantai , Deng Jianping
Published: February 2012

This communication reports the first integration of two significant concepts, “macromolecular helicity‐derived chirality,” and “magneticity” in one single microsphere entity. The novel chiral magnetic composite microspheres consisted of magnetic Fe3O4 nanoparticles and optically active helical substituted polyacetylene. Therefore, they exhibited both remarkable optical activity and magneticity. The microspheres adsorbed (R)‐(+)‐1‐phenylethylamine much more quickly than the other enantiomer, demonstrating the potential applications of the chiral magnetic composite microspheres in chiral recognition and chiral resolution.
The efficacy of in‐and‐out catheterization as a way of trial without catheterization strategy for treatment of acute urinary retention induced by benign prostate hyperplasia: Variables predicting success outcome
Authors: Ko Young Hwii , Kim Jin Wook , Kang Sung Gu , Jang Hoon Ah , Kang Seok Ho , Park Hong Seok , Moon Du Geon , Cheon Jun , Kim Je Jong , Lee Jeong Gu
Published: February 2012

Aim

To evaluate the efficacy and proper use of in‐and‐out catheterization as a strategy for trial without catheterization (TWOC) for treatment of acute urinary retention (AUR).

Methods

Retrospective analysis of 515 patients who visited the emergency room with AUR from January 2004 to December 2008 was conducted. Patients were segregated to one of two groups, depending on management of AUR (in‐and‐out catheterization at one time: Group 1 or indwelling catheter: Group 2). To characterize the optimal patient characteristics particularly fitting for Group 1 among each success subgroup, Fisher's linear discriminant analysis (LDA) was then conducted. Using an equation from LDA, the hit ratio was evaluated in a prospective trial from July to December 2009.

Results

TWOC success rate was 25.1% for Group 1 and 30.3% for Group 2. In successful cases, age, retention volume, and prostate sizes were significantly lower than those of failure counterparts in both Groups 1 and 2. Among these, age and retention volume were finally selected for LDA. When comparing successful cases, these two were significantly lower in Group 1 than Group 2. LDA showed an 81.6% hit ratio for cases with successful TWOC. In a prospective trial of 28 patients, using an equation from LDA, five of seven patients in Group 1 (71.4%) and 16 of 21 patients (76.2%) in Group 2 succeeded in their initial TWOC.

Conclusions

These results suggest the efficacy of in‐and‐out catheterization as a way of attempting TWOC, particularly for the patient with relatively low retention volume and younger age. Neurourol. Urodynam. 31:460–464, 2012. © 2012 Wiley Periodicals, Inc.
Resource allocation in an asymmetric technology race with temporary advantages
Authors: Golany Boaz , Kress Moshe , Penn Michal , Rothblum Uriel G.
Published: February 2012

We consider two opponents that compete in developing asymmetric technologies where each party's technology is aimed at damaging (or neutralizing) the other's technology. The situation we consider is different than the classical problem of commercial R&D races in two ways: First, while in commercial R&D races the competitors compete over the control of market share, in our case the competition is about the effectiveness of technologies with respect to certain capabilities. Second, in contrast with the “winner‐takes‐all” assumption that characterizes much of the literature on this field in the commercial world, we assume that the party that wins the race gains a temporary advantage that expires when the other party develops a superior technology. We formulate a variety of models that apply to a one‐sided situation, where one of the two parties has to determine how much to invest in developing a technology to counter another technology employed by the other party. The decision problems are expressed as (convex) nonlinear optimization problems. We present an application that provides some operational insights regarding optimal resource allocation. We also consider a two‐sided situation and develop a Nash equilibrium solution that sets investment values, so that both parties have no incentive to change their investments. © 2012 Wiley Periodicals, Inc. Naval Research Logistics 59: 128–145, 2012
The Effect of Requiring Private Employers to Extend Health Benefit Eligibility to Same‐Sex Partners of Employees: Evidence from California
Authors: Buchmueller Thomas C. , Carpenter Christopher S.
Published: February 2012

Health disparities related to sexual orientation are well documented and may be due to unequal access to a partner's employer‐sponsored insurance (ESI). We provide the literature's first evaluation of legislation enacted by California in 2005 that required private employers within the state to treat employees in committed same‐sex relationships in the same way as employees in different‐sex marriages with respect to ESI. Our analysis uses data on sexual orientation, partnership, and health insurance from the 2001 to 2007 California Health Interview Surveys (CHIS). Prior to the reform, partnered gay men and lesbians were significantly less likely to have ESI in someone else's name than partnered heterosexuals. Pooling data from 2001 to 2007, we find that the reform had no effects on differences in insurance outcomes between gay and straight men. We find some evidence that the reform increased partnership, reduced full‐time employment, and increased health insurance coverage among lesbians relative to heterosexual women. The increases in insurance coverage for lesbians are consistent with a role for expanded dependent ESI, suggesting that such policies may reduce sexual orientation‐based insurance disparities among women.
The management of menstrual suppression and uterine bleeding: A survey of current practices in the pediatric blood and marrow transplant consortium
Authors: Adegite Enitan A. , Goyal Rakesh K. , Murray Pamela J. , Marshal Mike , Sucato Gina S.
Published: February 2012

Background

Current guidelines recommend the use of combined hormonal contraceptive pills for menstrual suppression in pediatric blood and marrow transplant (BMT) recipients but recent research reveals that provider practice varies. This study was designed to describe the current practice for managing menstrual issues, that is, menstrual suppression and uterine bleeding, in pediatric BMT patients and to better understand health care providers' practices in the use of gonadotropin‐releasing hormone agonists (GnRHa).

Procedure

A cross sectional survey consisting of 53 questions was distributed via email to principal investigators in the Pediatric Blood and Marrow Transplant Consortium (PBMTC). Responses were collected using www.surveymonkey.com.

Results

Menstrual suppression and uterine bleeding in pediatric BMT patients are primarily managed by pediatric oncologists (97%). The most frequently reported hormonal method used for induction of therapeutic amenorrhea was GnRHa (41%). The top three reasons for choosing a method were greater likelihood of amenorrhea, concerns about side effects, and possible gonadal protection. Continuous combined hormonal contraceptive pills were the most commonly used method for the management of clinically significant uterine bleeding regardless of primary method used for menstrual suppression.

Conclusion

Despite the 2002 PBMTC guidelines, wide variation in menstrual suppression management practices still exists. Our data show that use of GnRHa is more common than previously reported. Additional research is needed to develop evidence‐based practice guidelines in pediatric BMT patients. Pediatr Blood Cancer 2012;59:553–557. © 2012 Wiley Periodicals, Inc.
New piezoelectric damping composites of poly(vinylidene fluoride) blended with clay and multi‐walled carbon nanotubes
Authors: Geng Chengzhen , Wang Jianchuan , Zhang Qin , Fu Qiang
Published: February 2012

Damping materials are used to control mechanical vibrations, and piezoelectric damping composite is a very promising material due to its unique mechanism. In this study, a potential piezoelectric damping composite was developed by simply melt mixing poly(vinylidene fluoride) (PVDF) with small amounts of organic modified montmorillonite (OMMT) and multi‐walled carbon nanotubes (MWCNTs). The piezoelectric, mechanical and electrical properties were investigated using a dynamic mechanical analyser, direct current electrical resistivity measurements, X‐ray diffraction, Fourier transform infrared spectroscopy and the direct quasi‐static d33 piezoelectric coefficient method. It was found that the damping property of PVDF can be greatly improved by adding both MWCNTs and OMMT, and the composite containing 1.9 wt% of MWCNTs and 3 wt% of OMMT showed the best damping property. A model and an approximate calculation were applied to explain the improved damping property. Moreover, similar mechanical properties of PVDF composites were observed in the tensile testing and dynamic mechanical analyser measurements. Copyright © 2012 Society of Chemical Industry
Original diols from sunflower and ricin oils: Synthesis, characterization, and use as polyurethane building blocks
Authors: Palaskar Dnyaneshwar V. , Boyer Aurélie , Cloutet Eric , Le Meins Jean‐François , Gadenne Benoit , Alfos Carine , Farcet Céline , Cramail Henri
Published: February 2012

A series of novel fatty acid‐based diols were designed and synthesized from sunflower and ricin oils using optimized chemical reactions and purifications. These diols were categorized in two different types: (i) fatty acid‐based monoester containing diols (FAmE‐1 to FAmE‐6) and (ii) fatty acid‐based diester containing diols (FAdE‐1 to FAdE‐8). Their synthesis involved a series of reactions such as transesterification, epoxidation, ring opening of epoxide, and thiol‐ene additions. Analyses of these new fatty acid‐based diols were performed by HPLC/GC and NMR spectroscopy. The latter were then demonstrated as polyurethane (PU) precursors in the bulk polymerization with isophorone diisocyanate in the presence of dibutyl tin dilaurate as a catalyst. The effects of the diol nature and purity on the PU synthesis and properties were investigated. The structural characterization of the different PUs was carried out by means of FTIR, 1H NMR, and 1H DOSY NMR spectroscopy. The thermomechanical and rheological properties of these new PUs were found dependent on the chemical structure and purity of the diol building block. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Synthesis, conformation transition, liquid crystal phase, and self‐assembled morphology of thermosensitive homopolypeptide
Authors: Liao Ye , Dong Chang‐Ming
Published: February 2012

Thermosensitive diethylene glycol‐derived poly(L‐glutamate) homopolypeptides (i.e., poly‐L‐EG2‐Glu) with different molecular weights (MW) (Mn,GPC = 5380–32520) were synthesized via the ring‐opening polymerization (ROP) of EG2‐L‐glutamate N‐carboxyanhydride (EG2‐Glu‐NCA) in N,N‐dimethylformamide solution at 50 °C. Their molecular structure, conformation transition, liquid crystal (LC) phase behavior, lower critical solution temperature (LCST) transition, and morphology evolution were thoroughly characterized by means of FTIR, 1H NMR, gel permeation chromatography, differential scanning calorimetry, wide angle X‐ray diffraction, polarized optical microscope, transmission electron microscope, and dynamic light scattering. In solid state, the homopolypeptide poly‐L‐EG2‐Glu presented a conformation transition from α‐helix to β‐sheet with increasing their MW at room temperature, while it mainly assumed an α‐helix of 80–86% in aqueous solution. Poly‐L‐EG2‐Glu showed a thermotropic LC phase with a transition temperature of about 100 °C in solid state, while it gave a reversible LCST transition of 34–36 °C in aqueous solution. The amphiphilic homopolypeptide poly‐L‐EG2‐Glu self‐assembled into nanostructures in aqueous solution, and their critical aggregation concentrations decreased with increasing MW. Interestingly, their morphology changed from spherical micelles to worm‐like micelles, then to fiber micelles with increasing MW. This work provides a simple method for the generation of different nanostructures from a thermosensitive biodegradable homopolypeptide. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Supramolecular star polymers with compositional heterogeneity
Authors: Gadwal Ikhlas , De Swati , Stuparu Mihaiela C. , Amir Roey J. , Jang Se Gyu , Khan Anzar
Published: February 2012

We present the synthesis of supramolecular star polymers with heterogeneous chemical compositions through potassium cation‐templated assembly of guanosine end‐functionalized random, diblock, and Y‐shaped copolymers. The assembly and disassembly processes of the synthesized star polymers have been systematically examined on changing the concentration, the temperature, the solvent, and the amount of cation using 1H NMR, UV/vis, and CD spectroscopy. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Hidden symmetries and integrability in higher dimensional rotating black hole spacetimes
Authors: Cariglia M. , Krtouš P. , Kubizňák D.
Published: February 2012

This is a short pedagogical introduction to the subject of Killing‐Stäckel and Killing–Yano tensors and their role in the integrability of various types of equations that are of physical interest in curved space‐time, the main application being higher dimensional rotating black holes with cosmological constant.
Branes and wrapping rules
Authors: Bergshoeff E.A. , Riccioni F.
Published: February 2012

We show that the solitonic branes of ten‐dimensional IIA/IIB string theory must satisfy, upon toroidal compactification, a specific wrapping rule in order to reproduce the number of half‐supersymmetric solitonic branes that follows from a supergravity analysis. The realization of this wrapping rule suggests that IIA/IIB string theory contains a whole class of so‐called “non‐standard” Kaluza‐Klein monopoles.
Using steric constraints to template an organic array on Si(111)‐7 × 7
Authors: McLean A. B. , Weymouth A. J. , Edge G. J. A. , Miwa R. H. , Srivastava G. P.
Published: February 2012

We show that the Si(111)‐7 × 7 surface reconstruction can be used to template an ordered array of 1,3,5‐trimethyl benzene (mesitylene) molecules. The disorder that normally derives from the multiplicity of admissible adsorption geometries, for small aromatic molecules on 7 × 7, is suppressed, and the molecules are found to occupy both halves of the 7 × 7 unit cell with equal probability. It is argued that a steric interaction, associated with the methyl groups, hinders nearest neighbor adsorption and this leads to the formation of an array that has the molecules at the corners of the 7 × 7 half unit cells. To understand the ordering kinetics we used: scanning tunneling microscopy to study site occupancy as a function of coverage, ab initio total energy calculation to study the stability of the attachment sites and kinetic Monte Carlo modeling to investigate the emergence of translational order in the overlayer.

magnified image

When two mesitylene molecules adsorb in nearest neighbor bridging geometries on the 7 × 7 reconstruction, the hydrogen atoms located on the methyl groups interact. To reduce the interaction energy, the molecules form an ordered array that places each molecule at the corner of the half cell.
Iron segregation in silicon‐on‐insulator wafer with polysilicon interlayer
Authors: Yli‐Koski M. , Haarahiltunen A. , Hintsala J. , Savin H.
Published: February 2012

We have studied iron gettering from monocrystalline silicon device layer into polycrystalline silicon (polysilicon) interlayer in thick bonded silicon‐on‐insulator (SOI) wafers. The results show that the polysilicon interlayer acts as an efficient gettering layer for iron. The gettering takes place via both the segregation and precipitation although the dominant gettering mechanism is segregation at low contamination levels. The activation energy of the segregation coefficient between the monocrystalline silicon and the polysilicon interlayer was found to be Ea = 1.9 ± 0.2 eV.
Excitonic states and their wave functions in anisotropic materials: A computation using the finite‐element method and its application to AlN
Authors: Gil Bernard , Felbacq Didier , Guizal Brahim , Bouchitté Guy
Published: February 2012

We have computed the excitonic states in the case of cylindrical symmetry as a function of the anisotropy using the finite‐element method. The wave functions are also obtained and are presented for m = 0, the states coupled with the electromagnetic fields. We illustrate for instance that the state dominantly built from the 3d0 hydrogenic level has a non‐vanishing oscillator strength when the anisotropy increases. As an illustration we conclude our message by the application of that calculation to the interpretation of the 1s–2s splitting in the specific case of aluminum nitride using the predictions of very recent band‐structure calculations.
Instability of amorphous oxide semiconductors via carrier‐mediated structural transition between disorder and peroxide state
Authors: Nahm Ho‐Hyun , Kim Yong‐Sung , Kim Dae Hwan
Published: February 2012

The excited holes occupying the valence band tail (VBT) states in amorphous oxide semiconductors (AOS) are found to induce formation of meta‐stable ${\rm O}_{2}^{{\rm 2}- } $ peroxide defects. The VBT states are at least partly characterized by the O–O ppσ* molecular orbital, and the localized‐hole‐mediated lattice instability results in the formation of the peroxide defects. Along with the O–O bond formation, the ppσ* state is heightened up into the conduction bands, and two electrons are accordingly doped in the electronic ground state. The energy barrier from the ${\rm O}_{2}^{{\rm 2}- } $ peroxide state to the normal disorder state is found to be 0.97 eV in hybrid density functional theory. The hole‐mediated formation of the meta‐stable peroxide defects and their meta‐stability is suggested as an origin of the negative bias and/or illumination stress instability in AOS.
Interdecadal variability of the ENSO–North Atlantic Oscillation connection in boreal summer
Authors: Wu Zhiwei , Lin Hai
Published: February 2012

Understanding the combined effect of El Niño–Southern Oscillation (ENSO) and the North Atlantic Oscillation (NAO) is of great importance for climate seasonal prediction (extreme climate events in particular). Results in this study show that during the last hundred years (1900 to present), the ENSO–NAO connection experiences a notable interdecadal change in summer (June–August) according to a 21‐year sliding correlation between them, namely, from no significant correlation (uncoupling) before the mid‐1970s to a significant correlation (coupling) after the mid‐1970s. Comparison analysis between the coupling epoch (1977–1997) and the uncoupling epoch (1958–1976) shows that the most pronounced circulation anomalies take place over the extratropical North Pacific. Further analysis and numerical experiments suggest that a poleward‐propagating Rossby wave train, possibly enhanced by sea‐surface‐temperature anomalies in the extratropical North Pacific associated with the developing phases of ENSO during the later epoch, is responsible for connecting the ENSO signal with the NAO. © 2012 Crown in the right of Canada. Published by JohnWiley & Sons Ltd.
Spectroscopic parameter and molecular constant investigations for low‐lying electronic states of P ion
Authors: Wang Jie‐Min , Feng Heng‐Qiang , Sun Jin‐Feng
Published: February 2012

The potential energy curves (PECs) of three low‐lying electronic states of P ion, X2Πu, A2Σ, and B2Σ, have been studied using the full valence complete active space self‐consistent field method followed by the highly accurate valence internally contracted multireference configuration interaction (MRCI) approach and MRCI with Davidson correction (+Q). The correlation‐consistent basis sets, aug‐cc‐pV5Z and aug‐cc‐pV6Z, are used and the total energies are extrapolated to the complete basis set limit. Using these PECs obtained with the MRCI+Q/56‐extrapolation, the spectroscopic parameters for these electronic states are determined and compared in detail with experimental data and those of previous studies reported in the literature. The comparison shows that excellent agreement exists between the present results and the available experiments. The first 40 vibrational states for the three electronic states are also computed when the rotational quantum number J equals zero. For each vibrational state, the vibrational level G(υ), inertial rotation constant Bυ, and centrifugal distortion constant Dυ are determined when J = 0, which are in good accord with the available measurements. © 2012 Wiley Periodicals, Inc.
Temperature dependence of the molecular conformations of dilauroyl phosphatidylcholine: A density functional study
Authors: Mineva Tzonka , Krishnamurty Sailaja , Salahub Dennis R. , Goursot Annick
Published: February 2012

Born–Oppenheimer molecular dynamics (BOMD) in combination with density functional theory, augmented with a damped empirical dispersion term, has been used to study the behavior of dilauroyl phosphatidylcholine (DLPC) isomers with temperature. In contrast to dimyristoyl phosphatidylcholine (DMPC), the BOMD results show the presence of various conformations at different temperatures. The molecular order–disorder process, quantified by the distance‐fluctuation criterion as a function of temperature, is characterized by two transitions. This is in line with the known two‐phase transitions of DLPC bilayers, involving trans to gauche conformational changes in the alkane chains. The different temperature dependence of the DLPC and DMPC molecules suggests that the experimentally observed unusual dynamics of DLPC bilayers compared to that of longer chain lipids is governed to a large extent by the intramolecular dynamics. A first‐principles methodology applied at the molecular level can thus be an appropriate tool for microscopic analysis of the order–disorder transitions, which are related to the molecular structural transformations within large assemblies. © 2012 Wiley Periodicals, Inc.
Characterizing optimal sampling of binary contingency tables via the configuration model
Authors: Blanchet Jose , Stauffer Alexandre
Published: February 2012

A binary contingency table is an m × n array of binary entries with row sums r = (r1, …, rm) and column sums c = (c1, …, cn). The configuration model generates a contingency table by considering ri tokens of type 1 for each row i and cj tokens of type 2 for each column j, and then taking a uniformly random pairing between type‐1 and type‐2 tokens. We give a necessary and sufficient condition so that the probability that the configuration model outputs a binary contingency table remains bounded away from 0 as
\documentclass{article} \usepackage{mathrsfs} \usepackage{amsmath} \pagestyle{empty} \begin{document} \begin{align*}N=\sum_{i=1}^m r_i=\sum_{j=1}^n c_j\end{align*} \end{document}
goes to ∞. Our finding shows surprising differences from recent results for binary symmetric contingency tables. © 2012 Wiley Periodicals, Inc. Random Struct. Alg., 2012
Roughness Parameters for Standard Description of Surface Nanoarchitecture
Authors: Webb Hayden K. , Truong Vi Khanh , Hasan Jafar , Fluke Christopher , Crawford Russell J. , Ivanova Elena P.
Published: February 2012

The nanoarchitecture and surface roughness of metallic thin films prepared by magnetron sputtering were analyzed to determine the topographical statistics that give the optimum description of their nanoarchitechture. Nanoscale topographical profiles were generated by performing atomic force microscopy (AFM) scans of 1 μm × 1 μm areas of titanium and silver films of three different thicknesses (3 nm, 12 nm, and 150 nm). Of the titanium films, the 150‐nm film had the highest average roughness (Ra = 2.63 nm), more than four times that of the 3‐nm and 12‐nm titanium films. When silver films were coated on top of 150‐nm titanium films, the average roughness increased further; the 3‐nm (Ra = 4.96 nm) and 150‐nm (Ra = 4.65 nm) silver films average roughnesses were approximately twice that of the 150‐nm titanium film. For topographical analysis, seven statistical parameters were calculated. These parameters included commonly used roughness measurements, as well as some less commonly used measurements, in order to determine which combination of parameters gave the best overall description of the nanoarchitecture of the films presented. Skewness (Rskw), surface area increase (Rsa), and peak counts (Rpc) provided the best description of horizontal surface dimensions, and in conjunction with vertical descriptors Ra and Rq gave the best characterization of surface architecture. The five roughness parameters Ra, Rq, Rskw, Rsa, and Rpc are proposed as a new standard for describing surface nanoarchitecture. SCANNING 34: 257‐263, 2012. © 2012 Wiley Periodicals, Inc.
Fabricating Nanostructures Through a Combination of Nano‐Oxidation and Wet Etching on Silicon Wafers With Different Surface Conditions
Authors: Huang Jen‐Ching
Published: February 2012

This study investigates the surface conditions of silicon wafers with native oxide layers (NOL) or hydrogen passivated layers (HPL) and how they influence the processes of nano‐oxidation and wet etching. We also explore the combination of nano‐oxidation and wet etching processes to produce nanostructures. Experimental results reveal that the surface conditions of silicon wafers have a considerable impact on the results of nano‐oxidation when combined with wet etching. The height and width of oxides on NOL samples exceeded the dimensions of oxides on HPL samples, and this difference became increasingly evident with an increase in applied bias voltage. The height of oxidized nanolines on the HPL sample increased after wet etching; however, the width of the lines increased only marginally. After wet etching, the height and width of oxides on the NOL were more than two times greater than those on the HPL. Increasing the applied bias voltage during nano‐oxidation on NOL samples increased both the height and width of the oxides. After wet etching however, the increase in bias voltage appeared to have little effect on the height of oxidized nanolines, but the width of oxidized lines increased. This study also discovered that the use of higher applied bias voltages on NOL samples followed by wet etching results in nanostructures with a section profile closely resembling a curved surface. The use of this technique enabled researchers to create molds in the shape of a silicon nanolens array and an elegantly shaped nanoscale complex structures mold. SCANNING 34: 264‐270, 2012. © 2012 Wiley Periodicals, Inc.
The Fabrication and Preservation of Nanostructures on Silicon Wafers With a Native Oxide Layer
Authors: Huang Jen‐Ching , Wang Jui‐Yang
Published: February 2012

This study used nano‐oxidation lithography to create oxidized circular nanostructures on a silicon wafer with a native oxide layer (NOL). We also investigated the impact of wet etching on the size of circular oxidized nanostructures and examined how the method and duration of preservation affect them. Experimental results show that the height and width of oxidized circular nanostructures increase proportionally with applied voltage. After wet etching, an increase in applied voltage resulted in a marked increase in the width of the circular nanostructures, a decrease in the inner diameter, and little variation in height. We further demonstrated that in a moist environment, the oxidation process continues, resulting in a further increase in height and width. During the initial stages of preservation, these changes occurred rapidly; however, the increase was negligible after 30 days. We propose the concept of reaction area (RA) ratio to explain the above phenomenon and provide evidence to support these claims. Our results led us to a simple and yet effective method of preserving oxidized circular nanostructures, called the electrostatic patch preservation (EPP) method, to overcome problems associated with changes in size occurring during the preservation of silicon nanostructure molds. SCANNING 34: 347–356, 2012. © 2012 Wiley Periodicals, Inc.
Exploration and exploitation strategies, profit performance, and the mediating role of strategic learning: Escaping the exploitation trap
Authors: Sirén Charlotta A. , Kohtamäki Marko , Kuckertz Andreas
Published: February 2012

This study focuses on the role of strategic learning as a mediating construct between opportunity‐seeking (exploration) and advantage‐seeking (exploitation) strategies and profit performance. Prior studies argue that the effect of these core elements of strategic entrepreneurship (exploration and exploitation) cannot be fully captured through their direct effects on profit performance, but that this relationship consists of mediating factors. This study proposes that the process of strategic learning, through its intraorganizational elements that enable the dissemination, interpretation, and implementation of strategic knowledge, enables firms to capitalize on the benefits of both exploration and exploitation strategies. Results from 206 Finnish software firms indicate that strategic learning fully mediates the relationship between exploration, exploitation, and profit performance. The result contributes by stressing the importance of strategic learning processes, especially in conjunction with entrepreneurial exploration strategies. Furthermore, the study demonstrates that the effect from exploration to strategic learning is moderated by the level of exploitation. This moderation effect suggests that the strategic learning is limited, being a path dependent capability that favors exploitation over exploration when stretched. However, strategic learning effectively allows both types of strategies to improve profit performance. Copyright © 2012 Strategic Management Society.
Orientation Dependence of Martensitic Transformation in High Mn TRIP/TWIP Steels
Authors: Yang Ping , Liu Tong‐Yan , Lu Fa‐Yun , Meng Li
Published: February 2012

Orientation dependence of transformation such as precipitation, allotropic transformation, martensitic transformation, or even twinning and recrystallization prevails strongly during dynamic transformation under deformation. Using mainly EBSD technique, this works reveals this behavior during tension and compression of high manganese TRIP/TWIP steels containing two types of martensites. The results show that this orientation dependence can lead to the differences in transformation kinetics, variant selection, the sizes, and orientations of new grains. These phenomena are ascribed to the influence of Schmid factor and strain accommodation in different deformation conditions.
An empirical methodology for human integration in the SE technical processes
Authors: Hardman Nicholas , Colombi John
Published: February 2012

This research examines quantitative methods to better integrate human considerations into early system design. Studies show that for human systems integration (HSI) concerns, systems engineers often rely on qualitative judgments or delay critical decisions until late in the system lifecycle; actions that have predictable cost, schedule, and performance consequences. Thus, empirical and quantifiable methods were pursued to improve the engineering of human HSI. These methods are mathematically rigorous, grounded in relevant theory, and apply human subjects data to critical systems development challenges. Their utility is demonstrated by application in support of three systems engineering activities: requirements elicitation, functional allocation, and user interface design. Together, they demonstrate a coherent approach to integrate human considerations into early system development—a key tenet of the INCOSE SE Handbook. © 2012 Wiley Periodicals, Inc. Syst Eng
Using a TRIZ framework for systems engineering trade studies
Authors: Blackburn Timothy D. , Mazzuchi Thomas A. , Sarkani Shahram
Published: February 2012

Identifying and appropriately resolving system tradeoffs or effectively evaluating alternatives is a key deliverable of systems engineering. Without proper resolution, system performance is hindered, or suboptimal technologies are chosen. TRIZ, the Theory of Inventive Problem Solving, offers tools and methods to identify and resolve tradeoffs (which it terms contradictions or conflicts). TRIZ recognizes that fundamental performance limits arise when one or more unresolved tradeoffs exist in a system. According to TRIZ, eliminating or reducing the effects of the conflicts is necessary to move to improved system performance. This paper presents a TRIZ Trade Study framework that is useful to identify system conflicts, both across alternatives and within a technology, and at various levels of requirements decomposition, to compare options and optimize how the system performs. The framework was developed to perform a trade study between alternative pharmaceutical production systems, and merges traditional trade study methodologies with classical TRIZ. Specifically, traditional pharmaceutical manufacturing development and manufacturing were traded against an emerging and proposed approach, QbD (Quality by Design). Given TRIZ is scalable and useful to a variety of systems, the application of the TRIZ Trade Study Framework is also broadly applicable across system scale and domains. © 2012 Wiley Periodicals, Inc. Syst Eng
A System‐Aware Cyber Security architecture
Authors: Jones Rick A. , Horowitz Barry
Published: February 2012

As exemplified in the 2010 Stuxnet attack on an Iranian nuclear facility, attackers have the capabilities to embed infections in equipment that is employed in nuclear power systems. In this paper, a new systems engineering focused approach for mitigating such risks is described. This approach involves the development of a security architectural formulation that integrates a set of reusable security services as an architectural solution that is an embedded component of the system to be protected. The System‐Aware architectural approach embeds security components into the system to be protected. The architecture includes services that (1) collect and assess real‐time security relevant measurements from the system being protected, (2) perform security analysis on those measurements, and (3) execute system security control actions as required. This architectural formulation results in a defense that is referred to as System‐Aware Cyber Security. This includes (1) the integration of a diverse set of dynamically interchangeable redundant subsystems involving hardware and software components provided from multiple vendors to significantly increase the difficulty for adversaries by avoiding a monoculture environment, (2) the development of subsystems that are capable of rapidly changing their attack surface through hardware and software reconfiguration (configuration hopping) in response to perceived threats, (3) data consistency checking services (e.g., intelligent voting mechanisms) for isolating faults and permitting moving surface control actions to avoid operations in a compromised configuration, and (4) forensic analysis techniques for rapid post‐attack categorization of whether a given fault is more likely the result of an infected embedded hardware or software component (i.e., cyber attack) or a natural failure. In this paper we present these key elements of the System‐Aware Cyber Security architecture and show, including an application example, how they can be integrated to mitigate the risks of insider and supply chain attacks. In addition, this paper outlines an initial vision for a security analysis framework to compare alternative System‐Aware security architectures. Finally, we summarize future research that is necessary to facilitate implementation across additional domains critical to the nation's interest. © 2012 Wiley Periodicals, Inc. Syst Eng
Acute exposure to pure cylindrospermopsin results in oxidative stress and pathological alterations in tilapia (Oreochromis niloticus)
Authors: Puerto María , Jos Angeles , Pichardo Silvia , Moyano Rosario , Blanco Alfonso , Cameán Ana M.
Published: February 2012

Cylindrospermopsin (CYN) is increasingly recognized as a potential threat to drinking water safety, due to its ubiquity. This cyanotoxin has been found to cause toxic effects in mammals, and although fish could be in contact with this toxin, acute toxicity studies on fish are nonexistent. This is the first study showing that single doses of CYN pure standard (200 or 400 μg CYN/kg fish bw) by oral route (gavage) generate histopathological effects in fish (Tilapia—Oreochromis niloticus) exposed to the toxin under laboratory condition. Among the morphological changes, disorganized parenchymal architecture in the liver, dilated Bowman's space in the kidney, fibrolysis in the heart, necrotic enteritis in the intestines, and hemorrhages in the gills, were observed. Moreover, some oxidative stress biomarkers in the liver and kidney of tilapias were altered. Thus, CYN exposure induced increased protein oxidation products in both organs, NADPH oxidase activity was significantly increased with the kidney being the most affected organ, and decreased GSH contents were also detected in both organs, at the higher dose assayed. © 2012 Wiley Periodicals, Inc. Environ Toxicol 29: 371–385, 2014.
Imaging of an atypical large perineal cyst diagnosed during pregnancy
Authors: Goldberg Y. , Lavie O. , Mandel R. , Auslender R.
Published: February 2012

Perineal cysts are quite frequent, almost 2% of women developing symptoms related to Bartholin or Gartner cysts. In most cases these cysts derive from embryological remnants or ectopic tissue, or form as epithelial inclusion cysts. These structures are usually asymptomatic unless they are complicated by infection. We report the sonographic and magnetic resonance imaging characteristics of a large perineal cyst diagnosed during the first trimester of an uncomplicated pregnancy, followed by conservative management during pregnancy and surgical excision in the puerperium. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.
Two‐dimensional sonographic placental measurements in the prediction of small‐for‐gestational‐age infants
Authors: Schwartz N. , Wang E. , Parry S.
Published: February 2012

Objectives

To determine the utility of two‐dimensional (2D) sonographic placental measurements in the prediction of small‐for‐gestational‐age (SGA) infants.

Methods

The maximal diameter along the fetal surface of the placenta and the maximal placental thickness were measured at 18–24 weeks' gestation, and the measurements repeated in the orthogonal plane. ‘Biometric lags’ were calculated as the difference between sonographic gestational age, estimated using each of a number of fetal biometric measurements, and actual gestational age. These variables were analyzed individually and in combination as predictors of birth weight < 10th percentile (SGA < 10) and < 5th percentile (SGA < 5).

Results

1909 singleton pregnancies were included. Mean placental diameter (SGA < 10, P < 0.001; SGA < 5, P = 0.002) and thickness (SGA < 10, P < 0.006; SGA < 5, P = 0.065) were significantly smaller in SGA pregnancies. The biometric lags were greater in SGA pregnancies, the lag in abdominal circumference (AC) being the most predictive of SGA (P < 0.0001). Multivariable models were significantly predictive of both SGA < 10th percentile (area under the receiver–operating characteristics curve (AUC) = 0.7404) and < 5th percentile (AUC = 0.7204), the best fitting models including AC lag and mean placental diameter and thickness.

Conclusions

2D placental measurements taken in mid‐gestation are significantly associated with the incidence of SGA. Biometric lags can improve the predictive ability further. These easily obtained variables should be considered in future efforts to develop a clinically useful predictive model for adverse outcome of pregnancy.
Organische UV‐Schutzschichten für die Polycarbonatverglasung
Authors: Präfke Christiane , Schulz Ulrike , Kaiser Norbert
Published: February 2012

Polycarbonat als Verglasungsmaterial im Außenbereich macht die Verwendung von funktionalen UV‐ und Kratzschutzschichten notwendig. Die Vakuumbeschichtungstechnik bietet eine Vielzahl von Technologien zur Herstellung solcher komplexer Beschichtungen. Ein wirksamer UV‐Schutz konnte dabei am Fraunhofer IOF durch die Abscheidung organischen UV‐Absorber entwickelt werden. Dazu wurden organische Verbindungen thermisch verdampft und sowohl als Einzelschichten als auch als Hybridschichten mit SiO2‐Matrixmaterial untersucht. Die UV‐Beständigkeit der Beschichtungen auf Polycarbonat konnte damit wesentlich erhöht werden.
Digitaler Gasdosierer im Grobvakuumbereich
Authors: Jitschin Wolfgang , Reinl Friedrich
Published: February 2012

Vakuummessgeräte werden kalibriert, indem man das zu kalibrierende Gerät mit einem Referenzgerät vergleicht. Beide Geräte sind an einem Rezipienten montiert. Nacheinander werden verschiedene Gasdrücke erzeugt und bei jedem Druck werden die Anzeigen der beiden Geräte notiert. Im Grobvakuumbereich erfolgt üblicherweise die Druckerzeugung durch sukzessive Zugabe von Gas in den Rezipienten mittels eines manuell bedienten Dosierventils. Die Druckeinstellung kostet erhebliche Zeit und beansprucht die Hand des Bedieners erheblich. Es wurde daher ein digitaler Gasdosierer mit elektromagnetischen Ventilen entwickelt, der eine schnellere und genauere Druckeinstellung als das analoge Dosierventil erlaubt und zudem die Hand des Bedieners schont. Der Gasdosierer und sein Einsatz werden beschrieben.
Establishing jet scaling patterns with a photon
Authors: Englert Christoph , Plehn Tilman , Schichtel Peter , Schumann Steffen
Published: February 2012

Abstract

Staircase and Poisson scaling are two typical patterns we observe for the exclusive number of jets at high energy hadron colliders. We examine these scaling properties for photon plus jets production at the LHC and find that this channel is well suited to study these features. We illustrate and discuss when to expect each of the two patterns, how to induce a transition through kinematic cuts, and how photons are related to heavy gauge bosons. Measurements of photon+jets production is therefore providing valuable information on exclusive jet scaling, which is going to help to eventually understand the theoretical origin of exclusive jet scaling properties in more detail.
Automatic verification of reduction techniques in Higher Order Logic
Authors: Abed Sa’ed , Ait Mohamed Otmane , Al Sammane Ghiath
Published: February 2012

In this paper we propose an automatic methodology to verify the soundness of model checking reduction techniques. The idea is to use the consistency of the specifications to verify if the reduced model is faithful to the original one. The user provides the reduction technique, the specification and the system under verification. Then, using Higher Order Logic he verifies automatically if the reduction technique is soundly applied. The method is completely defined in an MDG–HOL special integration platform that combines an automatic high level model checking tool Multiway Decision Graphs (MDGs) within the HOL theorem prover. We provide two case studies, the first one is the reduction using SAT–MDG of an Island Tunnel Controller and the second one is the MDG–HOL assume-guarantee reduction of the Look-Aside Interface. The obtained results of our approach offer a considerable gain in terms of the correctness of heuristics and reduction techniques as applied to commercial model checking, however a small penalty is paid in terms of CPU time and memory usage.