bluuebunny/crossref_metadata_2025 huggingface dataset:
Smart Search Engine
Authors: Al-anbaki Simaa Hassan Hadi
Published: June 2024

Existing information retrieval systems, such search engines, must be improved due to the issue of having too much information on the web or in broad sectors. More consideration is needed. Integrated search tools that can manage searches and filters effectively and show relevant results The main sitting technology is bloated with ever-increasing volumes of data, much like the Internet. You'll have finished your keyword research and all of this information one day. Its capacity to deliver timely information that people are seeking. Search engines work to overcome the restrictions imposed by the conventional method of keyword research as a result. This study seeks to outline the primary issues that keyword search engines currently face in order to keep up with the rapid expansion of the web and to meet all user expectations in a timely manner. In the next section, it examines a number of models that are not dependent on keywords that have been created, created, or used by researchers and search engines, and rates those technologies in accordance with the aspects that each search engine prioritizes in order to deliver results.
Ferromagnetic Target Detection in the Ocean Using Drone-based Magnetic Anomaly Detection
Authors: Yim Sinhyuk , Kim Dongkyu , Yoon Jihun , Bang Eunseok , Oh Seokmin , Kim Bona , Shim Kyumin , Lee Sangkyung
Published: June 2024

Magnetic anomaly signals from the ferromagnetic targets such as ships in the sea are measured by drone-based magnetic anomaly detection. A quantum magnetometer is suspended from the drone by 4 strings. Flight altitude and speed of drone are 100 m and 5 m/s, respectively. We obtain magnetic anomaly signals of few nT from the ships clearly. We analyze the signal characteristics by the ferromagnetic target through simulation using COMSOL multiphysics.
A Study on Standard Process of Risk Management for Defense Systems Test Works
Authors: Na Taeheum , Heo Dongeun , Kim Youngmin , Lee Jooyeoun
Published: June 2024

Today, risks created by uncertainty must be managed for successful project execution. From this perspective, applying a risk management process is very important for successful defense systems test works. This paper describes ‘the implentation of risk management process for test work’ carried out by DTERI’s process improvement activities. In this study, the concept of risk management process, and details of the risk management process are examined through PMBOK and ISO/IEC/IEEE 15288, CMMI. After that, we defined ‘Standard Process for Risk Management’ of defence systems test works. And, we describe ‘Risk Management Function’ of DTERI’s Project Management System(PMS) and the risk management process of DTERI. Finally, the effectiveness of the risk management standard process is verified through quantitative analysis.
Characteristic Property of Combustion and Internal Ballistics of Triple-Based Propellant according to Particle Size of RDX
Authors: Son Soojung , Lee Wonmin , Lee Woojin , Kim Daegeon
Published: June 2024

The important factors in the design of the gun propellant are impetus, flame temperature and pressure. In this paper, we considered a nitrocellulose based propellant composition that replaced sensitive NG(Nitroglycerin) with RDX(Cyclotrimethylenetrinitramine) and DEGDN(Diethylene glycol dinitrate) which high energy and low sensitivity. Particle size and content of RDX are the two main factors that affect the burning stability of RDX-based propellants. Among them, the characteristics of the propellant according to the particle size of RDX were confirmed. The relative combustion rate(R.Q., Relative Quickness) of the propellant changed according to the RDX particle size, and internal ballistics of properties of propellant were also varied. The particle size of RDX can be confirmed as a major factor in the combustion and internal ballistics characteristics of the propellant.
Functional Groups Containing Selenium and Tellurium in Oxidation States from 3 to 6
Authors: Piotr Kiełbasiński Wanda H. Midura , Drabowicz Józef
Published: September 2011

The chapter presents the progress made in recent years (mostly after 1987) in the chemistry of the selenium and tellurium compounds in oxidation states from 3 to 6 but, to make the presentation more comprehensible, it also contains selected references to earlier achievements. It is divided into seven sections, comprising particular classes of organoselenium and organotellurium derivatives which are discussed in the order of increasing oxidation states: selenonium and telluronium salts, selenoxides, telluroxides, selenimines and tellurimines, selenones, tellurones and selenoximines. All the sections are divided into subsections devoted to the synthesis and structure, reactivity and transformations and synthetic applications of the discussed classes of compounds. Particular emphasis is laid on the synthesis and properties of the chiral, non‐racemic forms of each class of compounds.
Adhesion Aspects in Composites
Authors: Ferraris Monica
Published: September 2011

An update on the most relevant issues on adhesion in composites is reviewed. Two aspects are considered: adhesion between the matrix and the reinforcing phase in composites and adhesion between composites to be joined to themselves or to other materials.

Polymer‐, ceramic‐, metal‐, glass‐, and glass‐ceramic‐matrix composites are considered.
Colorants for Composites
Authors: Lee Yong‐Keun
Published: September 2011

Colorants and special effect pigments are key ingredients of plastics compounds, offering countless possibilities to designers who want to differentiate their products. Color, simply stated, is light energy, reflected from or passing through an object, and viewed by a human observer or instrument detector. Colorants and the chemicals that may be added to, or naturally occur in, objects that modify the light energy produce the object's color. Colorants contain certain groups of atoms that selectively absorb certain wavelength of visible light and reflect the complementary color. These chemical groups are called
chromophores
. Other chemical groups, called
auxochromes
, may be present in a colorant molecule to modify the color and provide undertones.

Colorants can be dye, pigment, biological pigment, ink, paint, or colored chemicals. There are two major classifications of colorants used for the coloring of composites. They are dyes and pigments. Dyes are organic chemicals that are soluble in polymers and provide strong, transparent color and only produce color by light absorption. Pigments are essentially insoluble in plastic medium and must be mixed in a fine dispersion to provide uniform coloration.

Pigments can be further divided by chemistry into organic and inorganic types. Organic pigments provide strong, translucent or transparent color and have smaller average particle size than inorganic pigments. Conventional organic pigments have thermal stability lower than that of average inorganic pigment, and some can cause part warpage. More new, high heat‐resistant and high performance organic pigments are stable. As with dyes, pigments produce effects by mechanism of light absorption, but since many pigments (inorganic) have refractive indices greater than the plastics in which they are dispersed, pigments produce color effect by light scattering as well. Dyes, because of their fine particle size, tend to be transparent. Pigments have varied opacifying power.

Although dyes are gaining increasing acceptance, especially with the transparent plastics such as acrylic, rigid polyvinyl chloride (PVC), polyester, and polystyrene, their general industrial use has been limited. However, it must be stressed that if the plastic application requirements include bright shades, transparency, and good tintorial strength, the application of the dyes should be considered. Because of the limited use of dyes in plastics, the remainder of this discussion is directly to pigment properties and types.
Composite Impact
Authors: Liu Dahsin
Published: September 2011

This article outlines the fundamental issues involved in the investigations of composite materials that are subjected to impact loading. It addresses experimental techniques, numerical analysis, and composite response. In experimental techniques, low velocity impact, ballistic impact, crash impact, and blast impact are presented, while finite element method is the dominant subject for numerical analysis. Impact characteristics, damage process, delamination, and residual strength are of primary concerns of composite materials subjected to impact. Some suggested readings are also included at the end of the article.
Helicopter Composite Materials Applications: Airframe
Authors: Overd Michael
Published: September 2011

This article describes the challenges encountered by helicopter airframe designers and the reasons why composite materials are increasingly used in their designs. The pros and cons of composite materials are discussed and examples of the use of composite materials are given. A discussion of the comparative cost of ownership of metallic and composite helicopter airframes is also included.
Impact Damage
Authors: Chen Fujia , Hodgkinson John M.
Published: September 2011

Composite structures are susceptible to impact damage. Here we discuss the damage of composites subjected to impact with different velocity and energy. We summarize the testing and evaluation methods of impact resistance and damage toleration and conclude the effects of composite fiber structures and material properties on impact damage. Finally, we discuss the theoretical and numerical analyses of impact damage on composites.
Mechanical Aging
Authors: Piggott Michael R.
Published: September 2011

Fatigue of polymers and metals and of their fiber‐reinforced composites are described. Glass‐reinforced polymer laminates suffer from static fatigue, but reinforcing polymers with nanoparticles yield some benefits. Carbon‐reinforced polymers suffer negligible fatigue, static, or dynamic. Reinforced metals are not as fatigue resistant as reinforced polymers. Polymers creep under stress at room temperature, but metals do not creep till half the melting temperature (°K) is reached. Polymers also suffer stress relaxation. These potential weaknesses are described and discussed with particular attention given to fiber laminates and composites.
Nanofillers
Authors: Kim Dong Ouk , Lee Jun‐Ho , Hwang Taeseon , Oh Jun Suk , Hong Jung , Lee Pyoung‐Chan , Seferis James C. , Nam Jae‐Do
Published: September 2011

Among various nanofillers for composite systems, this article collectively summarizes several carbon‐based fillers and inorganic fillers, both attracting great attention recently in both the academia and industry for the advent of highly integrated electronic device and energy storage systems. The carbon‐based fillers include carbon nanotube, graphene, and graphene oxide, which are considered to open a new era of functionalized nanocomposite systems in the near future. The inorganic nanofillers include layered silicate, aluminum nitride, and boron nitride, which could substantially change mechanical, electrical, and thermal properties of the composite materials.
Vanadium Oxide Nanowire–Carbon Nanotube Binder‐Free Flexible Electrodes for Supercapacitors
Authors: Perera Sanjaya D. , Patel Bijal , Nijem Nour , Roodenko Katy , Seitz Oliver , Ferraris John P. , Chabal Yves J. , Balkus Kenneth J.
Published: September 2011

Vanadium pentoxide (V2O5) layered nanostructures are known to have very stable crystal structures and high faradaic activity. The low electronic conductivity of V2O5 greatly limits the application of vanadium oxide as electrode materials and requires combining with conducting materials using binders. It is well known that the organic binders can degrade the overall performance of electrode materials and need carefully controlled compositions. In this study, we develop a simple method for preparing freestanding carbon nanotube (CNT)‐V2O5 nanowire (VNW) composite paper electrodes without using binders. Coin cell type (CR2032) supercapacitors are assembled using the nanocomposite paper electrode as the anode and high surface area carbon fiber electrode (Spectracarb 2225) as the cathode. The supercapacitor with CNT‐VNW composite paper electrode exhibits a power density of 5.26 kW Kg−1 and an energy density of 46.3 Wh Kg−1. (Li)VNWs and CNT composite paper electrodes can be fabricated in similar manner and show improved overall performance with a power density of 8.32 kW Kg−1 and an energy density of 65.9 Wh Kg−1. The power and energy density values suggest that such flexible hybrid nanocomposite paper electrodes may be useful for high performance electrochemical supercapacitors.
Surface modification of polyethersulfone membrane to improve its hydrophobic characteristics for waste frying oil filtration: Radio frequency plasma treatment
Authors: Tur Eren , Onal‐Ulusoy Baran , Akdogan Ebru , Mutlu Mehmet
Published: September 2011

In this study, polyethersulfone (PES) membrane was subjected to surface modification using hexamethyldisiloxane (HMDSO) and 1,1,1,3,3,3‐hexafluoro‐2‐propanol (HFIP) in radio frequency (RF) plasma system to improve its hydrophobic property for recovery of waste frying oil. Structural and morphological changes on the membrane surfaces were characterized by contact angle measurements, Fourier transform infrared spectroscopy‐attenuated total reflection (FTIR‐ATR) and atomic force microscopy (AFM). Permeate fluxes, physical and chemical properties of waste frying oil and waste frying oil–methanol micella (oil/methanol 1/3, 1/1, 1/3, v/v) after filtration through unmodified and modified PES membranes were investigated. The results showed that PES membranes modified with HMDSO at 75 W for 5 min (discharge power–exposure time) selectively rejected total polar compounds (TPC) and free fatty acids (FFAs) of waste frying oil to the extent of 46.9–48% and 35.3–40%, respectively. Furthermore, the viscosity of waste frying oil was reduced to the extent of 9.4–12.8%. RF‐plasma‐treated PES membranes appeared to improve the regeneration of waste frying oils and allow these oils to be used for either repeated frying operations or biodiesel production. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123:3402–3411, 2012
Toughness improvement of epoxy networks by nanophase‐separating antiplasticizers
Authors: Laiarinandrasana L. , Fu Y. , Halary J. L.
Published: September 2011

Two epoxy‐amine networks were toughened by using a nanophase separating antiplasticizer at various contents ranging from 0 to 20 mol % with respect to the epoxide. These model networks were chosen to differ markedly by their glass transition temperature in the absence of additive, namely 180°C and 114°C. Net stress was measured as a function of crack opening displacement on single edge notch bending specimens. Analysis of the experimental data yielded both stiffness and fracture toughness. In addition, fracture surfaces were observed by scanning electron microscopy. Effect on both stiffness and toughness of network characteristics (nature of the hardener, amount of additive) were carefully examined. Conditions were found for which fracture energy at crack initiation substantially increases without any detrimental effect on stiffness. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Cloning and molecular characterization of an ornithine decarboxylase gene and its expression during embryonic development of the housefly, Musca domestica
Authors: Toutges Michelle J. , Santoso Adi
Published: September 2011

We are interested in identifying targets that may be used to develop new control products for the common housefly, Musca domestica, a vector of disease for many vertebrates. One such target, ornithine decarboxylase (ODC), is an embryonic enzyme involved in the regulation of polyamines and is a critical enzyme during M. domestica development. In this study, the cDNA for ODC from M. domestica was cloned, sequenced, and characterized. The full‐length cDNA was 1,337‐bp, consistent with a single band of approximately 1.35 kb obtained by northern analysis. The open‐reading frame contains 1,191 bp, yielding a deduced polypeptide of 396 amino acid residues with a predicted mass of 44,618 Da. The deduced M. domestica ODC protein was homologous to other ODC proteins. mRNA expression profiles analyzed by real‐time PCR indicated that the ODC transcript is temporally regulated throughout embryogenesis. Sequence data and Southern blot analysis suggests that there were likely only one or two closely linked copies of the M. domestica ODC gene. © 2011 Wiley Periodicals, Inc.
The Role of the nπ* 1Au State in the Photoabsorption and Relaxation of Pyrazine
Authors: Lin Chih‐Kai , Niu Yingli , Zhu Chaoyuan , Shuai Zhigang , Lin Sheng Hsien
Published: September 2011

The geometric, energetic, and spectroscopic properties of the ground state and the lowest four singlet excited states of pyrazine have been studied by using DFT/TD‐DFT, CASSCF, CASPT2, and related quantum chemical calculations. The second singlet nπ* state, 1Au, which is conventionally regarded dark due to the dipole‐forbidden 1Au←1Ag transition, has been investigated in detail. Our new simulation has shown that the state could be visible in the absorption spectrum by intensity borrowing from neighboring nπ* 1B3u and ππ* 1B2u states through vibronic coupling. The scans on potential‐energy surfaces further indicated that the 1Au state intersects with the 1B2u states near the equilibrium of the latter, thus implying its participation in the ultrafast relaxation process.
Site‐specific protein labeling with amine‐containing molecules using Lactobacillus plantarum sortase
Authors: Matsumoto Takuya , Takase Ryosuke , Tanaka Tsutomu , Fukuda Hideki , Kondo Akihiko
Published: September 2011

Modification of proteins with small molecules is a widely used and powerful tool in biological research. Enzymatic approaches are particularly promising because substrate specificity allows for site‐specific modification. Sortase A, a transpeptidase from Staphylococcus aureus, cleaves between the T and G residues in the sequence LPXTG, and subsequently links the carboxyl group of the T residue to an amino group of N‐terminal glycine oligomers by a native peptide bond. Although Gram‐positive bacteria have several kinds of sortases, there are few reports concerning their expression and substrate specificity. Here, we demonstrate site‐specific protein modification with primary amine‐containing molecules catalyzed by Lactobacillus plantarum sortase. Enhanced green fluorescent protein (EGFP) was employed as a model protein, and an amine‐containing biotin molecule was site‐specifically conjugated with LPQTSEQ‐tagged EGFP. We developed a novel Lactobacillus plantarum sortase that has different substrate specificity compared to Staphylococcus aureus sortase. Amine‐directed protein modification was achieved using the Lactobacillus plantarum sortase ''LPQTSEQ'' sequence original recognition tag. Our results demonstrate a promising method for expanding the capabilities of site‐specific protein‐small molecule modification.
High‐throughput assessment of antigen conformational stability by ultraviolet absorption spectroscopy and its application to excipient screening
Authors: Dasnoy Sébastien , Le Bras Vivien , Préat Véronique , Lemoine Dominique
Published: September 2011

In high‐throughput screening (HTS) assays, the use of ultraviolet absorption spectroscopy (UA) is commonly limited to concentration and turbidity measurements. Our aim was to evaluate microplate‐based UA and its second‐derivative [(2d)UA] for measuring the conformational stability of two recombinant antigenic proteins in the presence of 44 excipients. Protein conformational stability was assessed by (2d)UA upon titration with guanidine hydrochloride. (2d)UA was compared with tryptophan fluorescence spectroscopy (TF) and differential scanning fluorimetry (DSF), both commonly used techniques for measuring protein conformational stability. The HTS data were corrected for plate, row and column effects by applying a median polish procedure. Irrespective of the unfolding method applied, similar stabilizing excipients were identified by all analytical methods for a given antigen. The native forms of both antigens were destabilized by arginine, hydroxypropyl‐β‐cyclodextrin, and sodium docusate, and were protected by polyols. The median polish correction improved the quality of the prediction models and the screening resolution. The higher sensitivities of TF and DSF compared with (2d)UA allowed the identification of a larger number of stabilizing excipients. However, similar screening resolutions (z'‐factor > 0.8) were observed for 2dUA, TF, and DSF in a HTS of excipients applied to one of the antigens. Therefore, (2d)UA deserves more attention in HTS studies focused on protein conformational stability. Biotechnol. Bioeng. 2012; 109:502–516. © 2011 Wiley Periodicals, Inc.
Tissue‐specific biomass recalcitrance in corn stover pretreated with liquid hot‐water: Enzymatic hydrolysis (part 1)
Authors: Zeng Meijuan , Ximenes Eduardo , Ladisch Michael R. , Mosier Nathan S. , Vermerris Wilfred , Huang Chia‐Ping , Sherman Debra M.
Published: September 2011

Lignin content, composition, distribution as well as cell wall thickness, structures, and type of tissue have a measurable effect on enzymatic hydrolysis of cellulose in lignocellulosic feedstocks. The first part of our work combined compositional analysis, pretreatment and enzyme hydrolysis for fractionated pith, rind, and leaf tissues from a hybrid stay‐green corn, in order to identify the role of structural characteristics on enzyme hydrolysis of cell walls. The extent of enzyme hydrolysis follows the sequence rind < leaves < pith with 90% conversion of cellulose to glucose in 24 h in the best cases. Physical fractionation of corn stalks or other C4 grasses into soft and hard tissue types could reduce cost of cellulose conversion by enabling reduced enzyme loadings to hydrolyze soft tissue, and directing the hard tissue to other uses such as thermal processing, combustion, or recycle to the land from which the corn was harvested. Biotechnol. Bioeng. 2012; 109:390–397. © 2011 Wiley Periodicals, Inc.
Mechanistic Studies on the Reaction between Cob(II)alamin and Peroxynitrite: Evidence for a Dual Role for Cob(II)alamin as a Scavenger of Peroxynitrous Acid and Nitrogen Dioxide
Authors: Mukherjee Riya , Brasch Nicola E.
Published: September 2011

Peroxynitrite/peroxynitrous acid (ONOO−/ONOOH; pKa(ONOOH)=6.8) is implicated in multiple chronic inflammatory and neurodegenerative diseases. Both mammalian B12‐dependent enzymes are inactivated under oxidative stress conditions. We report studies on the kinetics of the reaction between peroxynitrite/peroxynitrous acid and a major intracellular vitamin B12 form, cob(II)alamin (Cbl(II)), using stopped‐flow spectroscopy. The pH dependence of the reaction is consistent with peroxynitrous acid reacting directly with Cbl(II) to give cob(III)alamin (Cbl(III)) and .NO2, followed by a subsequent rapid reaction between .NO2 and a second molecule of Cbl(II) to primarily form nitrocobalamin. In support of this mechanism, a Cbl(II)/ONOO(H) stoichiometry of 2:1 is observed at pH 7.35 and 12.0. The final major Cbl(III) product observed (nitrocobalamin or hydroxycobalamin) depends on the solution pH. Analysis of the reaction products in the presence of tyrosine—a well‐established .NO2 scavenger—reveals that Cbl(II) reacts with .NO2 at least an order of magnitude faster than tyrosine itself. Given that protein‐bound Cbl is accessible to small molecules, it is likely that enzyme‐bound and free intracellular Cbl(II) molecules are rapidly oxidized to inactive Cbl(III) upon exposure to peroxynitrite or .NO2.
Selectivity in the Addition Reactions of Organometallic Reagents to Aziridine‐2‐carboxaldehydes: The Effects of Protecting Groups and Substitution Patterns
Authors: Kulshrestha Aman , Schomaker Jennifer M. , Holmes Daniel , Staples Richard J. , Jackson James E. , Borhan Babak
Published: September 2011

Good to excellent stereoselectivity has been found in the addition reactions of Grignard and organozinc reagents to N‐protected aziridine‐2‐carboxaldehydes. Specifically, high syn selectivity was obtained with benzyl‐protected cis, tert‐butyloxycarbonyl‐protected trans, and tosyl‐protected 2,3‐disubstituted aziridine‐2‐carboxaldehydes. Furthermore, rate and selectivity effects of ring substituents, temperature, solvent, and Lewis acid and base modifiers were studied. The diastereomeric preference of addition is dominated by the substrate aziridines’ substitution pattern and especially the electronic character and conformational preferences of the nitrogen protecting groups. To help rationalize the observed stereochemical outcomes, conformational and electronic structural analyses of a series of model systems representing the various substitution patterns have been explored by density functional calculations at the B3LYP/6‐31G* level of theory with the SM8 solvation model to account for solvent effects.
Co3(HCOO)6 Microporous Metal–Organic Framework Membrane for Separation of CO2/CH4 Mixtures
Authors: Zou Xiaoqin , Zhang Feng , Thomas Sebastien , Zhu Guangshan , Valtchev Valentin , Mintova Svetlana
Published: September 2011

Continuous metal–organic framework‐type Co3(HCOO)6 intergrown films with a one‐dimensional zigzag channel system and pore aperture of 5.5 Å are prepared by secondary growth on preseeded macroporous glass‐frit disks and silicon wafers. The adsorption behavior of CO2 or CH4 single gases on the Co3(HCOO)6 membrane is investigated by in situ IR spectroscopy. It is shown that the isosteric heats of adsorption for CO2 (17.7 kJ mol−1) and CH4 (14.4 kJ mol−1) do not vary with increasing amount of adsorbed gases. The higher value of isosteric heat for CO2 is an indication of the stronger interaction between the CO2 and the Co3(HCOO)6 membrane. The Co3(HCOO)6 membrane is studied by binary gas permeation of CO2 and CH4 at different temperatures (0, 25, and 60 °C). The membrane has CO2/CH4 selectivity with a separation factor higher than 10, which is due to the unique structure and molecular sieving effect. Upon increasing the temperature from 0 to 60 °C, the preferred permeance of CO2 over CH4 is increased from 1.70×10−6 to 2.09×10−6 mol m−2 s−1 Pa−1, while the separation factor for CO2/CH4 shows a corresponding decrease from 15.95 to 10.37. The effective pore size of the Co3(HCOO)6 material combined with the pore shape do not allow the two molecules to pass simultaneously, and once the CO2 molecules are diffused in the micropores, the CH4 is blocked. The supported Co3(HCOO)6 membrane retains high mechanical stability after a number of thermal cycles.
Facile Preparation of Carbon Nanotube/Poly(ethyl 2‐cyanoacrylate) Composite Electrode by Water‐Vapor‐Initiated Polymerization for Enhanced Amperometric Detection
Authors: Chen Qiwen , Gan Zhibin , Wang Joseph , Chen Gang
Published: September 2011

A carbon nanotube/poly(ethyl 2‐cyanoacrylate) (CNT/PECA) composite electrode was developed for enhanced amperometric detection. The composite electrode was fabricated on the basis of water‐vapor‐initiated polymerization of a mixture of CNTs and ethyl 2‐cyanoacrylate in the bore of a piece of fused silica capillary. The morphology and structure of the composite were investigated by scanning electron microscopy, Fourier transform infrared spectroscopy, X‐ray diffraction, and thermogravimetric analysis. The results indicate that the CNTs were well dispersed and embedded throughout the PECA matrix to form an interconnected CNT network. The analytical performance of this unique CNT‐based detector has been demonstrated by separating and detecting six flavones in combination with capillary electrophoresis. The advantages of the CNT/PECA composite detector include lower operating potential, higher sensitivity, low expense of fabrication, satisfactory resistance to surface fouling, and enhanced stability; these properties indicate great promise for a wide range of applications.
Clinical significance of KISS1 protein expression for brain invasion and metastasis
Authors: Ulasov Ilya V. , Kaverina Natalya V. , Pytel Peter , Thaci Bart , Liu FeiFei , Hurst Douglas R. , Welch Danny R. , Sattar Husein A. , Olopade Olufunmilayo I. , Baryshnikov Anatoly Y. , Kadagidze Zaira G. , Lesniak Maciej S.
Published: September 2011

BACKGROUND:

Metastases to the brain represent a feared complication and contribute to the morbidity and mortality of breast cancer. Despite improvements in therapy, prognostic factors for development of metastases are lacking. KISS1 is a metastasis suppressor that demonstrates inhibition of metastases formation in several types of cancer. The purpose of this study was to determine the importance of KISS1 expression in breast cancer progression and the development of intracerebral lesions.

METHODS:

In this study, we performed a comparative analysis of 47 brain metastases and 165 primary breast cancer specimens by using the antihuman KISS1 antibody. To compare KISS1 expression between different groups, we used a 3‐tier score and the automated score computer software (ACIS) evaluation. To reveal association between mRNA and protein expression, we used quantitative reverse transcription‐polymerase chain reaction (qRT‐PCR) analysis. Significance of immunohistochemistry stainings was correlated with clinicopathological data.

RESULTS:

We identified that KISS1 expression is significantly higher in primary breast cancer compared with brain metastases (P < .05). The mRNA analysis performed on 33 selected ductal carcinoma brain metastatic lesions and 36 primary ductal carcinomas revealed a statistically significant down‐regulation of KISS1 protein in metastatic cases (P = .04). Finally, we observed a significant correlation between expression of KISS1 and metastasis‐free survival (P = .04) along with progression of breast cancer and expression of KISS1 in primary breast cancer specimens (P = .044).

CONCLUSIONS:

In conclusion, our study shows that breast cancer expresses KISS1. Cytoplasmic expression of KISS1 may be used as a prognostic marker for increased risk of breast cancer progression. Cancer 2012;. © 2011 American Cancer Society.
The potential for overuse of atypical thyroid diagnoses
Authors: Henry Michael
Published: September 2011

The atypical follicular cell diagnosis in the new Bethesda System for Reporting Thyroid Cytopathology is a heterogeneous category without well‐defined cellular criteria and has the potential for overuse. Laboratories should monitor the use of this diagnosis.
On multiwatermarking in cloud environment
Authors: Wang Jinwei , Lian Shiguo
Published: September 2011

Multiwatermarking is the technique to embed multiple messages into the same media content. It can be used to identify media content's owners or trace the illegal redistributors in media distribution. Especially in cloud environment with multiple content providers or users, multiwatermarking may have potential applications. However, some performances of multiple watermark embedding, for example, the distortion and security, are not considered. In this paper, the application scenarios of multiwatermarking in cloud environment are figured out, which investigate the secure media distribution models suitable for cloud‐based platform. Additionally, the multiwatermarking based on additive rule is studied and then analyzed theoretically from two aspects, one of which is the multi‐embedding of same watermark sequence and the other is the multiembedding of different watermark sequences. The analysis emphasizes on four aspects; that is, robustness, capacity, distortion, and security. And each of which considers two cases, that is, the authorized embedding and unauthorized embedding. Additionally, the correlation detection based on multiwatermarking is proposed, and for each case, the corresponding suggestions to improve system performance are proposed. Some comparative experiments are performed, and results are given to show the validity of these theoretical analysis.Copyright © 2011 John Wiley & Sons, Ltd.
Effect of an Ionic liquid on the Unfolding of Human Serum Albumin: A Fluorescence Correlation Spectroscopy Study
Authors: Kumar Das Dibyendu , Kumar Das Atanu , Kumar Mandal Amit , Mondal Tridib , Bhattacharyya Kankan
Published: September 2011

The effect of the room temperature ionic liquid (RTIL) 1‐pentyl‐3‐methyl‐imidazolium bromide ([pmim][Br]) on the unfolding of a protein, human serum albumin (HSA), is studied by fluorescence correlation spectroscopy (FCS). The structural fluctuations of the protein exhibit three characteristic time constants, namely, ∼3, ∼35 and ∼260 μs. On addition of the RTIL, the dynamics become slightly slower, with time constants of ∼5, ∼40 and ∼350 μs. The two fast components (3 and 35 μs in the absence of RTIL and 5 and 40 μs in the presence of RTIL) are assigned to chain motion of the protein. The slowest component (260 or 350 μs) may arise from detachment (unbinding) of the non‐covalent dye from the protein. In the absence of RTIL—and on addition of guanidinium hydrochloride (GdnHCl)—as the protein unfolds, the contribution of the fastest component increases rapidly from 10 % at 1 M to 40 % at 6 m, and its time constant decreases from 3 μs to 1 μs. In the presence of RTIL, the addition of GdnHCl causes significant changes in both the structure (CD spectrum) and the time constants of conformational fluctuation. In the presence of the RTIL, the addition of GdnHCl gives rise to a very slow component (1025 μs in 1 M and 560 μs in 6 M GdnHCl). It is proposed that the guanidinium cation (GdnH+) repels the imidazolium cation ([pmim]+) at the protein surface, and this causes a change in the structure and dynamics of the protein. On addition of 6 M GdnHCl, the diffusion coefficient of C153 bound to HSA decreases. The hydrodynamic radius of the denatured protein (in 6 M GdnHCl) is larger than that of the native protein (about 1.75 times in the absence of RTIL and 2.6 times in the presence of RTIL).
Solvothermal synthesis of flower‐like lanthanum tartrate and lanthanum oxide microspheres in ethanol‐water mixed system
Authors: Si Limin , Yue Linhai , Jin Dalai
Published: September 2011

Monodispersed lanthanum tartrate microspheres with flower‐like shape were synthesized by a mild solvothermal method using ethanol‐water mixed system as the solvent. Lanthanum oxide with reserved spherical shape was subsequently fabricated by a following calcination process. X‐ray diffraction analyses (XRD), X‐ray spectroscopy (EDS), scanning electron microscopy (SEM), thermogravimetry‐differential thermal analysis (TG‐DTA) were employed to characterize the composition, structure, and morphology of the products. The lanthanum tartrate microspheres were aggregated by nanosheets as petals. Size of the aggregation and thickness of the petal vary with the vol.% of ethanol. As the vol.% of ethanol increases the degree of aggregation and the thickness of the petal decrease, and other properties such as the size distribution, dispersion are also modulated. These alterations can be interpreted by the changing dielectric constant of mixed solvent. Such lanthanum tartrate can be applied to fabricate micro‐sphereshaped lanthanum oxide after calcination. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of Zn2+ ions concentration on the optical properties of Zn/Er:LiNbO3 crystals
Authors: Qian Yannan , Wang Rui , Xing Lili , Xu Yanling , Yang Chunhui , Liu Xinrong
Published: September 2011

Congruent Er3+(3 mol%):LiNbO3 crystals codoped with ZnO (X mol %, X=0, 3, 6 and 7) were grown by the Czochralski technique. The Er contents in the crystals were measured by an inductively coupled plasma atomic emission spectrometer (ICP‐AES). Under 800 nm excitation, the upconversion emission spectra reveal an enhancement of the green emission with respect to the red emission when the Zn2+ ions are introduced into Er:LiNbO3 crystal. The effect of Zn2+ ions concentration on the intensity ratio of the green to red emission has been investigated. Two cross‐relaxation processes (2H11/2 + 4I13/2 → 4I11/2 + 4F9/2 and 4F7/2 + 4I11/2 → 4F9/2 + 4F9/2) are involved in populating the 4F9/2 state, which bypass the green‐emitting states. The OH‐ absorption spectra indicate that the Zn2+ codoping leads to a decreased concentration of Er3+ cluster sites contributing to the enhancement of the green emission. The studies on UV‐vis absorption spectra show that the heavily codoped with Zn2+ results in the reformation of the Er3+ cluster sites in Er:LiNbO3. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Oligodeoxynucleotide IMT504: lack of effect on immune parameters during islet regeneration in single dose streptozotocin‐induced diabetes
Authors: Bianchi M. S. , Calvo V. , Chasseing N. A. , Lago N. , Libertun C. , Montaner A. D. , Lux‐Lantos V. A.
Published: September 2011

Background

We have shown that oligodeoxynucleotide IMT504 improved blood glucose and islet beta‐cell content in streptozotocin (STZ)‐induced diabetic rats, inducing early expression of progenitor markers. Here we determined the effect of IMT504 on islet infiltration and on immunomodulatory proteins indoleamine 2,3‐dioxygenase (IDO) and TNF‐α‐stimulated gene/protein 6 (TSG‐6) in islets of STZ‐diabetic rats, at the time of progenitor markers expression.

Methods

Male rats were i.p. injected with STZ [60 mg/kg body weight (BW)] or citrate buffer (control) (day 1). Starting on day 4, STZ animals were daily treated with saline (STZ‐saline) or IMT504 (20 mg/kg BW/day s.c., STZ‐IMT504) and killed after two consecutive decreases in blood glucose. Islet area and insulin expression, CD3 (T lymphocytes), CD68 (macrophages), IDO and TSG‐6 immunostainings were determined. Islet infiltration was also evaluated by haematoxylin staining.

Results

STZ‐induced diabetes in rats, with an important decrease in islet area was reversed by IMT504. Diabetes development did not involve islet infiltration, determined by haematoxylin and by the absence of significant T lymphocyte and macrophage presence. IMT504 did not induce changes in these parameters. IDO was not expressed in controls; the percentages of IDO‐positive islets were very low and similar in STZ‐saline and STZ‐IMT504. Scarce TSG‐6 was expressed in all groups, without significant differences.

Conclusions

IMT504 improved insulin content but did not alter IDO or TSG‐6 staining in islets of STZ‐diabetic rats, suggesting that they do not participate in the IMT504‐induced repair process. IMT504 did not per se modify leukocyte presence in islets of diabetic rats. Copyright © 2011 John Wiley & Sons, Ltd.
Genetic Connectivity among Populations of an Endangered Snake Species from Southeastern Australia (Hoplocephalus bungaroides, Elapidae)
Authors: Dubey Sylvain , Sumner Joanna , Pike David A. , Keogh J. Scott , Webb Jonathan K. , Shine Richard
Published: September 2011

For endangered species that persist as apparently isolated populations within a previously more extensive range, the degree of genetic exchange between those populations is critical to conservation and management. A lack of gene flow can exacerbate impacts of threatening processes and delay or prevent colonization of sites after local extirpation. The broad‐headed snake, Hoplocephalus bungaroides, is a small venomous species restricted to a handful of disjunct reserves near Sydney, Australia. Mark‐recapture studies have indicated low vagility for this ambush predator, suggesting that gene flow also may be low. However, our analyses of 11 microsatellite loci from 163 snakes collected in Morton National Park, from six sites within a 10‐km diameter, suggest relatively high rates of gene flow among sites. Most populations exchange genes with each other, with one large population serving as a source area and smaller populations apparently acting as sinks. About half of the juvenile snakes, for which we could reliably infer parentage, were collected from populations other than those in which we collected their putative parents. As expected from the snakes’ reliance on rocky outcrops during cooler months of the year, most gene flow appears to be along sandstone plateaux rather than across the densely forested valleys that separate plateaux. The unexpectedly high rates of gene flow on a landscape scale are encouraging for future conservation of this endangered taxon. For example, wildlife managers could conserve broad‐headed snakes by restoring habitats near extant source populations in areas predicted to be least affected by future climate change.
Nitrone Ylides: Two Possible 1,3‐Dipolar Cycloadditions but Only One Stepwise Formation of all‐cis‐5‐Aryl‐2,3,5‐trisubstituted N‐Hydroxypyrrolidines
Authors: Merino Pedro , Tejero Tomás , Díez‐Martínez Alba , Gültekin Zeynep
Published: September 2011

An efficient methodology for the synthesis of all‐cis‐N‐hydroxypyrrolidines has been developed through the formal [3+2] dipolar cycloaddition of electron‐poor alkenes and nitrone ylides generated from N‐(methoxycarbonylmethyl)nitrones. Treatment of the nitrone with a tertiary amine in the presence of either a lithium salt or butyllithium followed by addition of the alkene at low temperature provided the product in very good chemical yield and excellent diastereoselectivity. Isolation and characterization of a key intermediate demonstrated that the reaction is a stepwise process consisting of an initial Michael addition followed by an intramolecular Mannich‐type reaction.
Modulating cortico‐striatal and thalamo‐cortical functional connectivity with transcranial direct current stimulation
Authors: Polanía Rafael , Paulus Walter , Nitsche Michael A.
Published: September 2011

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that has been shown to alter cortical excitability and activity via application of weak direct currents. Beyond intracortical effects, functional imaging as well as behavioral studies are suggesting additional tDCS‐driven alterations of subcortical areas, however, direct evidence for such effects is scarce. We aimed to investigate the impact of tDCS on cortico‐subcortical functional networks by seed functional connectivity analysis of different striatal and thalamic regions to prove tDCS‐induced alterations of the cortico‐striato‐thalamic circuit. fMRI resting state data sets were acquired immediately before and after 10 min of bipolar tDCS during rest, with the anode/cathode placed over the left primary motor cortex (M1) and the cathode/anode over the contralateral frontopolar cortex. To control for possible placebo effects, an additional sham stimulation session was carried out. Functional coupling between the left thalamus and the ipsilateral primary motor cortex (M1) significantly increased following anodal stimulation over M1. Additionally, functional connectivity between the left caudate nucleus and parietal association cortices was significantly strengthened. In contrast, cathodal tDCS over M1 decreased functional coupling between left M1 and contralateral putamen. In summary, in this study, we show for the first time that tDCS modulates functional connectivity of cortico‐striatal and thalamo‐cortical circuits. Here we highlight that anodal tDCS over M1 is capable of modulating elements of the cortico‐striato‐thalamo‐cortical functional motor circuit. Hum Brain Mapp 33:2499–2508, 2012. © 2011 Wiley Periodicals, Inc.
Filtering the reality: Functional dissociation of lateral and medial pain systems during sleep in humans
Authors: Bastuji Hélène , Mazza Stéphanie , Perchet Caroline , Frot Maud , Mauguière François , Magnin Michel , Garcia‐Larrea Luis
Published: September 2011

Behavioral reactions to sensory stimuli during sleep are scarce despite preservation of sizeable cortical responses. To further understand such dissociation, we recorded intracortical field potentials to painful laser pulses in humans during waking and all‐night sleep. Recordings were obtained from the three cortical structures receiving 95% of the spinothalamic cortical input in primates, namely the parietal operculum, posterior insula, and mid‐anterior cingulate cortex. The dynamics of responses during sleep differed among cortical sites. In sleep Stage 2, evoked potential amplitudes were similarly attenuated relative to waking in all three cortical regions. During paradoxical, or rapid eye movements (REM), sleep, opercular and insular potentials remained stable in comparison with Stage 2, whereas the responses from mid‐anterior cingulate abated drastically, and decreasing below background noise in half of the subjects. Thus, while the lateral operculo‐insular system subserving sensory analysis of somatic stimuli remained active during paradoxical‐REM sleep, mid‐anterior cingulate processes related to orienting and avoidance behavior were suppressed. Dissociation between sensory and orienting‐motor networks might explain why nociceptive stimuli can be either neglected or incorporated into dreams without awakening the subject. Hum Brain Mapp, 2012. © 2011 Wiley Periodicals, Inc.
Crosstalk between mitochondrial (dys)function and mitochondrial abundance
Authors: Michel Sébastien , Wanet Anaïs , De Pauw Aurélia , Rommelaere Guillaume , Arnould Thierry , Renard Patricia
Published: September 2011

A controlled regulation of mitochondrial mass through either the production (biogenesis) or the degradation (mitochondrial quality control) of the organelle represents a crucial step for proper mitochondrial and cell function. Key steps of mitochondrial biogenesis and quality control are overviewed, with an emphasis on the role of mitochondrial chaperones and proteases that keep mitochondria fully functional, provided the mitochondrial activity impairment is not excessive. In this case, the whole organelle is degraded by mitochondrial autophagy or “mitophagy.” Beside the maintenance of adequate mitochondrial abundance and functions for cell homeostasis, mitochondrial biogenesis might be enhanced, through discussed signaling pathways, in response to various physiological stimuli, like contractile activity, exposure to low temperatures, caloric restriction, and stem cells differentiation. In addition, mitochondrial dysfunction might also initiate a retrograde response, enabling cell adaptation through increased mitochondrial biogenesis. J. Cell. Physiol. 227: 2297–2310, 2012. © 2011 Wiley Periodicals, Inc.
Long cycles in subgraphs of (pseudo)random directed graphs
Authors: Ben‐Eliezer Ido , Krivelevich Michael , Sudakov Benny
Published: September 2011

We study the resilience of random and pseudorandom directed graphs with respect to the property of having long directed cycles. For every 08γ81/2 we find a constant c = c(γ) such that the following holds. Let G = (V, E) be a (pseudo)random directed graph on n vertices and with at least a linear number of edges, and let G′ be a subgraph of G with (1/2 + γ)|E| edges. Then G′ contains a directed cycle of length at least (c − o(1))n. Moreover, there is a subgraph G′′of G with (1/2 + γ − o(1))|E| edges that does not contain a cycle of length at least cn. © 2011 Wiley Periodicals, Inc. J Graph Theory 70: 284–296, 2012