bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relationship Between RDX Properties and Sensitivity
Authors: Doherty Ruth M. , Watt Duncan S. 
Published: February 2008

AbstractAn interlaboratory comparison of seven lots of commercially available RDX was conducted to determine what properties of the nitramine particles can be used to assess whether the RDX has relatively high or relatively low sensitivity. The materials chosen for the study were selected to give a range of HMX content, manufacturing process and reported shock sensitivity. The results of two different shock sensitivity tests conducted on a PBX made with the RDX lots in the study showed that there are measurable differences in the shock sensitivity of the PBXs, but the impact sensitivity for all of the lots is essentially the same. Impact sensitivity is not a good predictor of shock sensitivity for these types of RDX. Although most RDX that exhibits RS has low HMX content, that characteristic alone is not sufficient to guarantee low sensitivity. A range of additional analytical chemistry tests were conducted on the material; two of these (HPLC and DSC) are discussed within.
Reduced Sensitivity RDX Obtained From Bachmann RDX
Authors: Spyckerelle Christian , Eck Geneviève , Sjöberg Per , Amnéus Anna‐Maria 
Published: February 2008

AbstractIn recent years much interest has been generated in a quality of reduced sensitivity RDX (RS‐RDX), like I‐RDX® which, when incorporated in cast cure and even pressable plastic bonded explosives (PBX compositions), can confer reduced shock sensitivity as measured through gap test. At crystal level, lot of work has been done to try to determine which property or properties may explain the behaviour of the corresponding cast PBX composition. But up to now, and despite an international inter‐laboratory comparison (Round Robin) of seven lots of RDX from five different manufacturers conducted from 2003 to 2005, even if some techniques lead to interesting results, there is no dedicated specification to apply to RS‐RDX. This quality (I‐RDX®) has proved to retain its low sensitivity even after ageing, which does not seem to be the case for standard RDX produced by the Bachmann process (when re‐crystallized under I‐RDX conditions in order to obtain RS‐RDX). It has been shown that the higher sensitivity of RDX produced by the Bachmann process, or the evolution of sensitivity after ageing of RS‐RDX produced from Bachmann RDX may be linked to the presence of octogen (HMX) during the crystallization process. In order to check such hypothesis, low HMX content RDX produced by the Bachmann process has been prepared and evaluated in cast PBX composition (PBX N 109). Results of the characterization of such quality of RDX and its evaluation in cast PBX composition as well as ageing behaviour are presented and discussed; there are indications that removal of HMX from Bachmann RDX may lead to RS‐RDX, which retains its RS character even after ageing.
RDX and HMX with Reduced Sensitivity Towards Shock Initiation–RS‐RDX and RS‐HMX
Authors: Hammer Johansen Øyvind , Digre Kristiansen Jørn , Gjersøe Richard , Berg Alf , Halvorsen Terje , Smith Kjell‐Tore , Nevstad Gunnar Ove 
Published: February 2008

AbstractReduced Sensitivity RDX (RS‐RDX) has received a lot of attention and interest from the explosive community in the recent years. There are several producers of RS‐RDX, most of them using a direct nitration (Woolwich process) for the RDX synthesis, while Chemring Nobel uses the Bachmann process. The processes for obtaining the RS properties probably differ between the various producers. Chemring Nobel has also developed an HMX quality that shows Reduced Sensitivity (RS‐HMX) of different particle size distributions. The shock sensitivity is at the same level as for RS‐RDX in comparable compositions. Reduced shock sensitivity has been obtained for RS‐RDX and Reduced Sensitivity (RS‐HMX) in both pressable and cast‐cured compositions. By using a pressable composition, it is possible to get the results from a BICT gap test faster than from a cast‐cured composition that has to go through a curing process. Chemring Nobel in cooperation with FFI have performed an extensive accelerated ageing testing of RS‐RDX produced by the Bachmann process. The samples have been aged at 60 and 70 °C and the shock sensitivity tested by two different gap tests. The results demonstrate that the Chemring Nobel RS‐RDX retain the insensitivity towards shock during ageing and show no degradation at all. Accelerated ageing testing of RS‐HMX has also been performed and shows no degradation in the shock sensitivity.
Reduced Sensitivity RDX (RS‐RDX) in Pressed Formulations: Respective Effects of Intra‐Granular Pores, Extra‐Granular Pores and Pore Sizes
Authors: Borne Lionel , Mory Julien , Schlesser Franck 
Published: February 2008

AbstractReduced sensitivity RDX (RS‐RDX) particles are now available from several manufacturers. But a clear understanding of this reduced sensitivity behavior is not yet available. RS‐RDX particles are usually employed in cast formulations to reduce their shock sensitivity. The use of RS‐RDX in pressed formulations is more recent and does not always give reduced sensitivity formulations.
Particle Size Modification of Thermally Stable Secondary Explosives for IM Applications
Authors: Parker Adam , Claridge Robert P. , Hamid Javid , Proud William G. 
Published: February 2008

AbstractAs well as improving the survivability of weapons and platforms, insensitive munitions (IM) reduce both casualty rates and mission losses. Their use also leads to improved safety during storage and transportation. For a munition to fulfil IM criteria, each of its energetic sub‐sections must be IM compliant. The initiator and explosive train are the most critical of these sub‐systems as their safety and reliability are of paramount importance if the weapon is to be suitable for service use, yet they are generally the most difficult part of a weapon to protect from inadvertent initiation. As part of an ongoing study into initiation methods suitable for use in IM systems, an investigation into the behaviour of energetic materials when impacted by laser‐driven flyers was performed. Laser‐based detonators exhibit increased safety characteristics over conventional initiation methods as they can be based on insensitive secondary explosives rather than sensitive primary explosives. Also, they are less susceptible to accidental initiation due to an external hazard threat. Single pulses from a high‐powered Q‐switched Nd:YAG laser were used to launch flyers from substrate‐backed aluminium films to velocities up to 6 km s−1 across a short stand‐off to impact explosive targets. Several novel energetic materials have been selected for investigation as potential candidates for inclusion within flyer‐based initiation systems and explosive train applications. The materials are of interest due to their increased thermal stability and power output over conventional explosives currently in service. Attempts were made to increase the flyer responsiveness of the materials by tuning their particle size using ultrasound. The effect of particle size on the initiation threshold energy was investigated for three materials.
Solution structure, antibacterial activity, and expression profile of Manduca sexta moricin
Authors: Dai Huaien , Rayaprolu Subrahmanyam , Gong Yuxi , Huang Rudan , Prakash Om , Jiang Haobo 
Published: February 2008

AbstractIn response to wounding or infection, insects produce a battery of antimicrobial peptides (AMPs) and other defense molecules to kill the invading pathogens. To study their structures, functions, and transcriptional regulation, we synthesized Manduca sexta moricin, a 42‐residue peptide (GKIPVKAIKQAGKVIGKGLRAINIAGTTHDVVSFFRPKKKKH, 4539 Da). The compound exhibited potent antimicrobial activities against a broad spectrum of Gram‐positive and Gram‐negative bacteria with a minimum inhibitory concentration of 1.4 µM. The mRNA levels of M. sexta moricin increased substantially in fat body and hemocytes after the larvae were challenged with bacterial cells. We determined the solution structure of this AMP by two‐dimensional 1H1H ‐nuclear magnetic resonance spectroscopy. The tertiary structure is composed of an eight‐turn α‐helix spanning almost the entire peptide. Insights of relationships between the structure and function are also presented. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.
Isolation and characterization of a C12‐lipopeptide produced byBacillus subtilisHSO 121
Authors: Liu Xiang‐Yang , Yang Shi‐Zhong , Mu Bo‐Zhong 
Published: February 2008

AbstractA new lipopeptide with C12fatty acid has been isolated from the cell broth ofBacillus subtilisHSO121 by chromatographic methods, which is believed to be the homologue of lipopeptides. The fatty acid portion was methylated and analyzed by GC/MS, ESI Q‐TOF MS and1H‐NMR. The peptide portion, of which the amino acid composition was obtained by HPLC combined with a phenyl isothiocyanate (PITC) derivatization methods, was analyzed by ESI Q‐TOF MS. Comparing the obtained results with surfactin C13showed that the new lipopeptide has a peptide moiety similar to that of surfactin and the difference exists in the fatty acid portion, which is an iso‐C12β‐hydroxy fatty acid. The critical micelle concentration (CMC) of this new homologue is estimated to be 6.27 × 10−5mol/l in 10 mmol/l phosphate buffer solution (PBS, pH 8.0) at 30 °C, and the surface tension at CMC (γCMC) achieved is as little as 27.71 mN/m. The hemolytic activities of the C12‐lipopeptide on 2% human erythrocytes showed a HC50of 26.5 µmol/l. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.
High‐throughput solid‐phase permethylation of glycans prior to mass spectrometry
Authors: Kang Pilsoo , Mechref Yehia , Novotny Milos V. 
Published: February 2008

AbstractPermethylation of glycans prior to their mass spectrometric determination has now become a time‐honored methodology in glycoconjugate analysis due to the advantage of a simultaneous analysis of neutral and acidic glycans as well as enhanced sensitivity and easier tandem mass spectrometry interpretation. While the different solvent extraction‐based versions of this method often suffice in different structural studies, they are generally less satisfactory in the quantitative determinations aiming at minor quantities of the analyzed materials. To overcome these difficulties, we recently introduced a solid‐phase capillary permethylation technique (Kang et al., Rapid Commun. Mass Spectrom. 2005; 19: 3421) for microscale determination. Here, we describe a very useful high‐throughput extension of the solid‐phase methodology utilizing spin columns packed with sodium hydroxide beads. This procedure has been thoroughly optimized to match the analytical performance parameters of the previously used capillary technique. As demonstrated with a high‐precision glycomic profiling analysis of human blood serum, this methodological improvement offers simplicity and reproducibility, allowing the complete permethylation of 12–18 samples in less than 20 min. Copyright © 2008 John Wiley & Sons, Ltd.
Simultaneous use of gas chromatography/ion trap mass spectrometry ‐ electron capture detection to improve the analysis of bromodiphenyl ethers in biological and environmental samples
Authors: Wang Dongli , Atkinson Shannon , Hoover‐Miller Anne , Shelver Weilin L. , Li Qing X. 
Published: February 2008

AbstractBromodiphenyl ethers (BDEs) are a class of synthetic flame retardants and are widely present in the environment. Analysis of higher BDE congeners has proven to be a challenge. We report the development of a method that enhances their analysis by splitting the eluent of a gas chromatograph (GC) between an electron capture detector (ECD) and an ion trap mass spectrometer (ITMS): 1:10, ECD:ITMS. This allowed the quantitation of the lower molecular weight (MW) BDE congeners (Br1–Br7) with the ITMS and of the higher MW BDEs (Br8–Br10) with the highly sensitive ECD. The IT temperature, ionization mode, and MS/MS parameters (excitation amplitude and stability parameter) were optimized. This method took the advantages of the best detector for the different BDE homologues and was suitable for the analysis of BDEs in environmental and biological samples. Average recoveries were 52–112% for BDEs from spiked sand samples and 57–126% from spiked lard samples after accelerated solvent extraction followed by silica gel and alumina column clean‐up. Average recoveries ranged from 51% to 130% for 13C‐labeled BDEs spiked in the real and in matrix samples. The method detection limits for specific congeners were 0.18–120 pg/g of the BDEs in animal tissue samples, and 0.05–40 pg/g in soil and indoor dust samples. The utility of the method was demonstrated by analyzing actual harbor seal blubber, indoor dust and soil samples. The concentration of each BDE ranged from non‐detectable (nd) to 41 ng/g in the dry soil sample, nd to 1042 ng/g in the indoor dust, nd to 15 ng/g wet weight in the Alaskan harbor seal blubber sample, and 0.02 to 11 ng/µL of the identified 23 of the 42 breakdown products from BDE‐209 after zerovalent iron treatment. Finally, an interlaboratory comparison showed high correspondence between the GC/ITMS‐ECD method and a GC high‐resolution MS system for the analysis of BDEs in soil samples. Copyright © 2008 John Wiley & Sons, Ltd.
Dehydroalanine derived from cysteine is a common post‐translational modification in human serum albumin
Authors: Bar‐Or Raphael , Rael Leonard T. , Bar‐Or David 
Published: February 2008

AbstractThe conversion of a cysteine residue into dehydroalanine (DHA) in proteins was previously described. This post‐translational modification (PTM) can be generated artificially as a result of heat and an alkaline environment. The presence of this PTM on human serum albumin (HSA) in plasma collected from healthy volunteers and critically ill patients as well as in commercially available HSA was studied. Using liquid chromatography/mass spectrometry (LC/MS) and matrix‐assisted laser desorption/ionization tandem mass spectrometry (MALDI‐MS/MS) methods, a fragment containing DHA was identified in the trypsin digest of commercial HSA and isolated HSA from plasma. The sequence (RPC*FSALEVDETYVPK) corresponded to the expected molecular mass and fragmentation pattern of a tryptic peptide of HSA where the cysteine residue (cys487) was modified to DHA. The presence of this common PTM of HSA has potential effects on ligand binding to HSA, plasma clearance of this oxidized form of HSA, protein‐protein interactions, and oxidation‐reduction potential. Copyright © 2008 John Wiley & Sons, Ltd.
Cellular proteins detected in HIV‐1
Authors: Ott David E. 
Published: February 2008

AbstractIt has been known for some time that HIV‐1 virions contain cellular proteins in addition to proteins encoded by the viral genome. Recent studies have vastly increased the number of host proteins detected in HIV‐1. This review summarises the current findings on several cellular proteins present in these virions, including some functional studies on their potential roles in the viral replication cycle and pathogenesis. Because retroviruses require extensive assistance from host proteins and pathways, the data from biochemical characterisations of HIV‐1 serve as an important starting point for understanding the role of cellular proteins that act in or influence the biology of HIV‐1. Additionally, a better understanding of the interactions between cellular proteins and viral components might provide more targets for anti‐HIV therapeutic intervention and provide for a better understanding of how HIV‐1 alters the immune system. The extensive study of HIV‐1 has already brought new insights to the fields of immunology and vaccine science. In the same way, knowledge of viral‐‐cellular protein interactions might assist our understanding of important cellular pathways. Copyright © 2008 John Wiley & Sons, Ltd.
Stability‐ and performance‐robustness tradeoffs: MIMO mixed‐µvscomplex‐µ design
Authors: Vasconcelos J. F. , Athans M. , Fekri S. , Silvestre C. , Oliveira P. 
Published: February 2008

AbstractWe present a non‐trivial case study designed to highlight some of the practical issues that arise when using mixed‐µ or complex‐µ robust synthesis methodologies. By considering a multi‐input multi‐output three‐cart mass–spring–dashpot (MSD) with uncertain parameters and dynamics, it is demonstrated that optimized performance (disturbance‐rejection) is reduced as the level of uncertainty in one or two real parameters is increased. Comparisons are made (a) in the frequency domain, (b) by RMS values of key signals and (c) in time‐domain simulations. The mixed‐µ controllers designed are shown to yield superior performance as compared with the classical complex‐µ design. The singular value decomposition analysis shows the directionality changes resulting from different uncertainty levels and from the use of different frequency weights. The nominal and marginal stability regions of the closed‐loop system are studied and discussed, illustrating how stability margins can be extended at the cost of reducing performance. Copyright © 2008 John Wiley & Sons, Ltd.
Insulator nanocapillary production from biological sample
Authors: Bereczky R. J. , Tökési K. , Varga D. , Zhang Z. M. , Ding Z. J. 
Published: February 2008

AbstractDiatoms are unicellular microscopic organisms with silicon dioxide‐based cylindrical‐shaped skeletons, enveloped with an organic material composed of essentially polysaccharides and proteins. By removing the organic compounds from the diatom, we present an alternative method for the preparation of insulating nanocapillaries. The lengths of the capillaries are about 100 µm and the diameters of the regularly structured pores are about 200 nm. Moreover, we confirm with measurements by XPS that the shell of the Pennales diatoms contains mostly SiO2. Copyright © 2008 John Wiley & Sons, Ltd.
Growth and adhesion of biphasic crystalline–amorphous Sm/FeTaN magnetic nanospheroids on a Ta surface
Authors: Cefalas A. C. , Kovač J. , Sarantopoulou E. , Dražić G. , Kollia Z. , Kobe S. 
Published: February 2008

AbstractThe adhesion strength of magnetic films of intermetallic alloys on different substrates specifies their long‐term magnetic functionality, among other physicochemical characteristics of the films. Nanospheroids of Sm/FeTaN intermetallic alloys were grown from the Sm13.8 Fe82.2 Ta4.0 target by pulse laser deposition at 157 nm. The high‐temperature, liquefied nanodroplets were formed in the plume. They eventually solidified on the surface of a Ta substrate covered with a thin Ta/O layer in the form of biphasic nanospheroids, consisting of a crystalline nucleus surrounded by an amorphous mantle. Such nanostructures exhibit a ferromagnetic response because the oxidization of the inner crystalloid nucleus, which specifies the magnetic properties, is prevented by the amorphous spheroid mantle. The strength of adhesion of the nanodroplets on the Ta substrate was inversely proportional to the Sm/Fe concentration. The nanodroplets with high Sm/Fe concentration were bound on the Ta substrate with a large average contact angle of ∼161.4° due to the strong intermolecular forces in the alloy. The nanodroplets with low Sm/Fe concentration exhibited hydrophilic binding, and they were strongly attached to the Ta substrate with an average contact angle of 11.3° . Magnetic force microscopy measurements revealed that the magnetic response of the nanospheroids was proportional to the contact angle. Copyright © 2008 John Wiley & Sons, Ltd.
An aspect‐oriented software architecture for code mobility
Authors: Lobato Cidiane , Garcia Alessandro , Romanovsky Alexander , Lucena Carlos 
Published: February 2008

AbstractMobile agents have come forward as a technique for tackling the complexity of open distributed applications. However, the pervasive nature of code mobility implies that it cannot be modularized using only object‐oriented (OO) concepts. In fact, developers frequently evidence the presence of mobility scattering in their system's modules. Despite these problems, they usually rely on OO application programming interfaces (APIs) offered by the mobility platforms. Such classical API‐oriented designs suffer a number of architectural restrictions, and there is a pressing need for empowering developers with an architectural framework supporting a flexible incorporation of code mobility in the agent applications. This work presents an aspect‐oriented software architecture, called ArchM, ensuring that code mobility has an enhanced modularization and variability in agent systems, and is straightforwardly introduced in otherwise stationary agents. It addresses OO APIs' restrictions and is independent of specific platforms and applications. An ArchM implementation also overcomes fine‐grained problems related to mobility tangling and scattering at the implementation level. The usefulness and usability of ArchM are assessed within the context of two case studies and through its composition with two mobility platforms. Copyright © 2008 John Wiley & Sons, Ltd.
Mixed-type gastric carcinomas exhibit more aggressive features and indicate the histogenesis of carcinomas
Authors: Zheng Hua-chuan , Li Xiao-han , Hara Takuo , Masuda Shinji , Yang Xiang-hong , Guan Yi-fu , Takano Yasuo 
Published: February 2008

AbstractTo investigate the pathobiological behaviors of gastric mixed-type (MT) carcinomas and gastric carcinogenesis, the clinicopathological characteristics of MT carcinomas were analyzed and compared with intestinal-type (IT) and diffuse-type (DT) carcinomas. The expression of Ki-67, caspase-3, p53, fragile histine triad (FHIT), maspin, extracellular matrix metalloproteinase inducer (EMMPRIN), vascular growth factor (VEGF), MUC-2, 4, 5AC and 6, CD44, E-cadherin, β-catenin, and phosphorylated glycogen synthase kinase 3β-ser9 (P-GSK3β-ser9) was examined on tissue microarrays using immunohistochemistry. It was found that MT carcinomas exhibited large size, deep invasion, frequent local invasion, and lymph node metastasis in comparison with IT and DT carcinomas (p < 0.05). All the markers except MUC-5AC showed higher expression in IT than DT carcinomas (p < 0.05). The expression of maspin, EMMPRIN, VEGF, MUC-4, and membrane E-cadherin was stronger in MT intestinal than diffuse component (p < 0.05). Immunoreactivities to Ki-67, EMMPRIN, and VEGF were weaker in IT carcinoma than in the MT intestinal portion (p < 0.05), while the opposite was true for CD44, MUC-2, and MUC-6 (p < 0.05). The MT diffuse component displayed a higher expression of FHIT, VEGF, and P-GSK3β-ser9 than DT carcinoma (p < 0.05). The accumulative survival rate of the IT carcinoma patients was higher than the other types (p < 0.05). The invasive depth, venous invasion, lymph node, peritoneal or liver metastasis, and Lauren's classification were independent prognostic factors for gastric carcinomas (p < 0.05). These findings suggested that MT carcinomas were also indicated to be more aggressive than IT and DT carcinomas. Significant differences were observed in the proliferation, apoptosis, angiogenesis, mucin secretion, and cell adhesion between IT and DT carcinomas, whereas only a few of these characteristics showed differences between the MT intestinal and diffuse parts, thus suggesting that both the MT components might originate from the stem cells with similar genetic traits, but follow different histogenic pathways.