bluuebunny/crossref_metadata_2025 huggingface dataset:
In‐Flight Vehicle Health Management
Authors: Srivastava Ashok N. , Meyer Claudia , Mah Robert W.
Published: December 2010

Integrated Vehicle Health Management (IVHM) is a complex, multidisciplinary science that draws upon numerous fields including aerospace engineering, electrical engineering, computer science, mechanical engineering, statistics, and many sub‐disciplines of these fields. As operational costs rise for modern aerospace systems, health management technologies are becoming more critical from both safety and maintenance perspectives.

The ultimate goal of an IVHM system is to detect, diagnose, predict, and mitigate adverse events during the operation of a system. Many traditional approaches to systems engineering break down the system into its constituent subsystems and components, each of which draws from its own scientific or engineering discipline. From a health management perspective, this is not sufficient; system‐level integration of subsystem health management capabilities is critical to the overall effectiveness of the final implementation. Moreover, the health management system design is sometimes an afterthought rather than an integral part of the design process. This can lead to a situation where appropriate sensing technologies, computational environments, and information management systems are not included in the final design.

This chapter describes a systematic approach to the development of IVHM technologies and systems that emphasizes IVHM's most important goals – detection, diagnosis, prognosis, and mitigation – in a system or subsystem‐independent manner.
Cognitive Engineering and Aviation Safety
Authors: Pritchett Amy R. , Lewis David S.
Published: December 2010

Humans are a unique and vital component of aviation that can adapt their behavior in response to new circumstances. Some aspects of human behavior, such as reaction time to clearly defined tasks, can be modeled in isolation. Other aspects can be predicted as a response to their situation, in which they will adapt to maintain “control” and achieve the desired combined system performance. Cognitive engineering is the discipline of designing complex, safety‐critical systems recognizing the need for good human performance. The design challenge is to properly enable humans' performance in situations both expected and unexpected. With the design of technology, procedures, and training to support their adaptation to the inherent dynamics of aviation operations, humans serve as the greatest contribution to safety. Conversely, in an inflexible system human dynamism becomes the source of error and faults. Thus, an important aspect of design is to both prevent predictable faults and to ensure the system has the flexibility by which humans can return things to right. This requires explicit choices in distributing responsibility for risk mitigation and safety between technology, operating procedures, and human performance, recognizing that automation brings with it risks that are increasingly difficult for human operators to handle.
Human Spaceflight Risk Management
Authors: Apt Jay
Published: December 2010

Deaths and close calls have occurred in both the initial development and mature operation phases of human spaceflight. The spacecraft, ground operators, flight crew, and the structure of the spaceflight organization each present opportunities for risk analysis, management, and mitigation. An understanding of the nature of problem definition and verification is required to adequately manage risks. If the formal requirements of verification of proposed solutions to design and organizational artifact construction are not understood, risks are greatly increased. Spacecraft and organizational design risk management can be addressed, but require both rigorous tools and continuous attention to both engineering and organizational behavior.
Flight Control for Rotorcraft
Authors: Clarke Tim
Published: December 2010

In this chapter, we consider some of the practical issues necessary to take idealized flight control laws, perhaps developed using classical or modern control engineering design methodologies, to their implementation on a real flight vehicle. We restrict the discussion to the conventional, single main rotor, tail rotor configuration.
Digital Image Correlation in Experimental Mechanics for Aerospace Materials and Structures
Authors: Daly Samantha H.
Published: December 2010

Digital Image Correlation (DIC) is a non‐contact optical method used to measure full‐field surface deformations. The technique is a fast, robust, highly scalable and accurate method for determining both the surface profile of a three‐dimensional object and the displacements (Lagrangian strains) on the surface of the object. From its inception in the early 1980s, the capabilities of computer‐based digital image correlation have grown tremendously. Since that time, it has proven to be an indispensable tool in the experimental characterization of structures and materials over a wide range of length and time scales. This chapter discusses the fundamental principles underlying the technique and its application in the experimental characterization of aerospace materials and structures.
Communication Satellites
Authors: Hoeber Christopher F.
Published: December 2010

This chapter gives an overview of the history and current applications of communications satellites, as well as their typical architecture and the technologies used to make them work. Fifty years ago, pioneering communications satellites relayed a handful of signals between two huge ground antennas. Today, their powerful sophisticated descendants broadcast video and audio to millions of users, provide Internet access capacities of more than 100 Gbps, support two‐way personal communications to tiny personal antennas in satellite phones, and transport huge amounts of business information. Modern satellites are complex marvels of systems engineering, balancing and integrating many subsystems and functions into systems that optimize communications capacity and performance, reliability, mass, and cost. The design has evolved to large body stabilized box‐shaped spacecraft with deployable solar arrays and antennas, directing radio frequency waves to the Earth at high power. The communications payload repeater and antenna engineering strategies as discussed in this chapter illustrate how major requirements are addressed and technologies are selected. The bus or platform discussion highlights the technologies that support the payload through launch vibration, bring it to its assigned orbit location and keep it there, point it very accurately, power and control it, and so on. These bus subsystems include power, structures, mechanisms, thermal control, attitude and orbit control, command and data handling, and propulsion.
Science Satellites – Landers and Rovers
Authors: Kornfeld Richard P.
Published: December 2010

Since the dawn of space exploration more than 50 years ago, bold attempts to land rovers and landers on other celestial objects were undertaken. While initial exploration focused on the Moon and the neighboring planets ‐ Venus and Mars, more recent exploration included the surfaces of asteroids, comets, and some of the outer planets and its moons. This chapter surveys past, present, and potential future surface missions, discusses some of the engineering considerations applicable to landers and rovers, and closes with case studies of missions to the Moon, Venus, and Mars.
Science Satellites: Interplanetary Spacecraft
Authors: McNutt Ralph L.
Published: December 2010

Interplanetary spacecraft have played key roles in both scientific exploration of the solar system and national policy from the beginning of the Space Age. Initially simple low‐mass satellites, interplanetary spacecraft have become major scientific investigations with multiple international connections for answering fundamental questions about the origin, state, and evolution of all major bodies in the solar system. Such spacecraft and their payloads represent significant investments of both time and money and must operate reliably under extreme conditions. While relying on many satellite standard parts and some satellite standard systems, interplanetary spacecraft represent a small fraction of all spacecraft launched. Pressing the limits of launch vehicle, propulsion, telecommunications, and spacecraft longevity, these machines are custom made to their missions and continue to return knowledge of our universe that can be obtained in no other way to Earth from across the solar system and beyond.
Elevated pulmonary artery pressure among Amhara highlanders in Ethiopia
Authors: Hoit Brian D. , Dalton Nancy D. , Gebremedhin Amha , Janocha Allison , Zimmerman Peter A. , Zimmerman Allison M. , Strohl Kingman P. , Erzurum Serpil C. , Beall Cynthia M.
Published: December 2010

Objective

Pulmonary arterioles respond to hypoxia with constriction that raises vascular resistance and pulmonary artery blood pressure. The response is sustained indefinitely by the chronic hypoxia of high‐altitude residence among highlanders of European and Andean descent, but not Tibetans. The objective of this study was to identify the consequences of lifelong hypoxia exposure for the pulmonary vasculature among Amhara high‐altitude natives from Ethiopia.

Methods

A three‐way static group comparison tested for the effect of Amhara ancestry and high residence altitude on pulmonary hemodynamics measured using echocardiography in samples of 76 healthy adult Amhara lifelong residents at 3700 m, 54 Amhara lifelong residents at 1200 m, and 46 U.S. low‐altitude residents at 282 m.

Results

Amhara at 3700 m had average Doppler‐estimated pulmonary artery systolic pressure (tricuspid regurgitant gradient) of 27.9 ± 8.4 (SD) mm Hg as compared with 21.9 ± 4.0 among Amhara at low altitude and 16.5 ± 3.6 in the U.S. low‐altitude reference sample. However, there was no residence altitude effect on pulmonary blood flow or vascular resistance. Amhara ancestry was associated with greater pulmonary artery systolic pressure and pulmonary blood flow, yet lower pulmonary vascular resistance.

Conclusions

The Amhara at 3700 m had elevated pulmonary artery pressure, but without the elevated pulmonary vascular resistance characteristic of the classic model of the response to long‐term hypoxia by the pulmonary vasculature. The elevated pressure among Amhara may be a consequence of high pulmonary blood flow regardless of altitude and represent a newly identified pattern of response. Am. J. Hum. Biol., 2011. © 2010 Wiley‐Liss, Inc.
Synthesis and Antimicrobial Activity of Some New N‐Substituted Quinoline Derivatives of 1H‐Pyrazole
Authors: Thumar Nilesh J. , Patel Manish P.
Published: December 2010

A new series of 32 derivatives of 4‐pyrazolyl‐N‐(hetero)arylquinoline 5a–p and 6a–p were synthesized by a one‐pot base‐catalyzed cyclocondensation reaction of 1‐phenyl‐3‐(hetero)aryl‐pyrazole‐4‐carbaldehyde 1a–h, malononitrile 2, and 3‐(hetero)aryl‐5,5‐disubstitutedcyclohex‐2‐enone 3a–b or 4a–b, respectively. All the synthesized compounds were characterized by elemental analysis, FT‐IR, 1H‐NMR, and 13C‐NMR spectral data. All the synthesized compounds were screened, against six bacterial pathogens, namely Bacillus subtilis, Clostridium tetani, Streptococcus pneumoniae, Salmonella typhi, Vibrio cholerae, Escherichia coli, and antifungal activity, against two fungal pathogens Aspergillus fumigatus and Candida albicans, using broth microdilution MIC method. Some of the compounds were found to be more or equipotent against most of the employed strains than commercially available drugs as evident from the screening data.
New Insights into Keggin‐Type 12‐Tungstophosphoric Acid from 31P MAS NMR Analysis of Absorbed Trimethylphosphine Oxide and DFT Calculations
Authors: Huang Shing‐Jong , Yang Chih‐Yi , Zheng Anmin , Feng Ningdong , Yu Ningya , Wu Pei‐Hao , Chang Yu‐Chi , Lin Ying‐Chih , Deng Feng , Liu Shang‐Bin
Published: December 2010

The acid and transport properties of the anhydrous Keggin‐type 12‐tungstophosphoric acid (H3PW12O40; HPW) have been studied by solid‐state 31P magic‐angle spinning NMR of absorbed trimethylphosphine oxide (TMPO) in conjunction with DFT calculations. Accordingly, 31P NMR resonances arising from various protonated complexes, such as TMPOH+ and (TMPO)2H+ adducts, could be unambiguously identified. It was found that thermal pretreatment of the sample at elevated temperatures (≥423 K) is a prerequisite for ensuring complete penetration of the TMPO guest probe molecule into HPW particles. Transport of the TMPO absorbate into the matrix of the HPW adsorbent was found to invoke a desorption/absorption process associated with the (TMPO)2H+ adducts. Consequently, three types of protonic acid sites with distinct superacid strengths, which correspond to 31P chemical shifts of 92.1, 89.4, and 87.7 ppm, were observed for HPW samples loaded with less than three molecules of TMPO per Keggin unit. Together with detailed DFT calculations, these results support the scenario that the TMPOH+ complexes are associated with protons located at three different terminal oxygen (Od) sites of the PW12O403− polyanions. Upon increasing the TMPO loading to >3.0 molecules per Keggin unit, abrupt decreases in acid strength and the corresponding structural variations were attributed to the change in secondary structure of the pseudoliquid phase of HPW in the presence of excessive guest absorbate.
Anionic Activators for Differential Sensing with Cell‐Penetrating Peptides
Authors: Montenegro Javier , Matile Stefan
Published: December 2010

The design, synthesis, and evaluation of small peptides with one to three negative charges and one to three hydrazides as key components of membrane‐based synthetic sensing systems are reported. Their spontaneous reaction with hydrophobic aldehydes or ketones gives rapid access to small collections of amphiphilic anions. These anionic amphiphiles can activate polycations as anion transporters in lipid‐bilayer membranes. Odorants are used as representative hydrophobic aldehydes and ketones, and cell‐penetrating peptides (CPPs) as polycationic transporters in fluorogenic vesicles. Different activities obtained with different counterion activators are used to generate multidimensional patterns that can be recognized by principal component and hierarchical cluster analysis to extract unique “fingerprints” for individual analytes (including enantiomers, cis–trans isomers or perfumes as illustrative analyte mixtures). Comparison of the peptide activators reveals that carboxylates perform better than phosphonates. Gemini‐like activators containing two carboxylates and two hydrophobic hydrazone tails are best, whereas excessive charges and tails give weaker activities. This result differs from cationic activators of polyanionic transporters such as DNA, which worked best with octopus amphiphiles with one cationic head and four hydrophobic tentacles.
Mesenchymal stem cells from development to postnatal joint homeostasis, aging, and disease
Authors: De Bari Cosimo , Kurth Tobias B. , Augello Andrea
Published: December 2010

Joint morphogenesis involves signaling pathways and growth factors that recur in the adult life with less redundancy to safeguard joint homeostasis. Loss of such homeostasis due to abnormal signaling networks as in aging could lead to diseases such as osteoarthritis. Stem cells are the cellular counterpart and targets of the morphogenetic signals, and they function to maintain the tissues by ensuring replacement of cells lost to physiological turnover, injury, aging, and disease. Mesenchymal stem cells (MSCs) are key players in regenerative medicine for their ability to differentiate toward multiple lineages such as cartilage and bone, but they age along the host body and senesce when serially passaged in culture. Understanding correlations between aging and its effects on MSCs is of the utmost importance to explain how aging happens and unravel the underlying mechanisms. The investigation of the MSC senescence in culture will help in developing more efficient and standardized cell culture methods for cellular therapies in skeletal regenerative medicine. An important area to explore in biomedical sciences is the role of endogenous stem cell niches in joint homeostasis, remodeling, and disease. It is anticipated that an understanding of the stem cell niches and related remodeling signals will allow the development of pharmacological interventions to support effective joint tissue regeneration, to restore joint homeostasis, and to prevent osteoarthritis. Birth Defects Research (Part C) 90:257–271, 2010. © 2010 Wiley‐Liss, Inc.
Überspannung „sichtbar“ gemacht
Authors: Wille Leif , Witt Alexander , Flint Alfred
Published: December 2010

In der technischen Anwendung von Elektrolysen, aber auch im Unterricht bei der Behandlung des Themas „Elektrochemie“ spielt die Überspannung eine bedeutende Rolle. Klassisch wird dieses Thema über die Ermittlung unterschiedlicher Zersetzungsspannungen beim gleichen Elektrolyten aber unterschiedlichem Elektrodenmaterial erschlossen. Im Folgenden wird nun ein Vorschlag unterbreitet, wie man ausgehend von einem überraschenden Ergebnis bei einer Elektrolyse schließlich zu einem Experiment kommt, in dem die vom Elektrodenmaterial abhängige Überspannung zur Abscheidung von Wasserstoff und Sauerstoff quasi „offensichtlich“ wird.
Adsorption of Amaranth Dye onto Alumina Reinforced Polystyrene
Authors: Ahmad Rais , Kumar Rajeev
Published: December 2010

Adsorptive removal of toxic amaranth dye by alumina reinforced polystyrene (ARP) composite was studied as a function of contact time, pH, initial dye concentration, and temperature. The results indicated that adsorption was strongly dependent on pH and temperature of the dye solution. The adsorption was favored at low pH with the maximum removal at pH 2.0. Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich (D–R) models were used for the description of adsorption equilibrium data and the best interpretation for the experimental data was given by the D–R model. The adsorption kinetics was tested using pseudo first order, pseudo second order, Elovich, intraparticle, and film diffusion models and the removal by ARP followed a pseudo second order kinetics. Thermodynamic studies revealed that both adsorption and desorption was spontaneous and endothermic in nature. From the exhausted adsorbent, about 70 and 96% desorption was obtained with (99%) CH3OH and 0.1 M NaOH, respectively.
Synthesis and in vitro/in vivo Evaluation of the Antitrypanosomal Activity of 3‐Bromoacivicin, a Potent CTP Synthetase Inhibitor
Authors: Conti Paola , Pinto Andrea , Wong Pui E. , Major Louise L. , Tamborini Lucia , Iannuzzi Maria C. , De Micheli Carlo , Barrett Michael P. , Smith Terry K.
Published: December 2010

The first convenient synthesis of enantiomerically pure (αS,5S)‐α‐amino‐3‐bromo‐4,5‐dihydroisoxazol‐5‐yl acetic acid (3‐bromoacivicin) is described. We demonstrate that 3‐bromoacivicin is a CTP synthetase inhibitor three times as potent as its 3‐chloro analogue, the natural antibiotic acivicin. Because CTP synthetase was suggested to be a potential drug target in African trypanosomes, the in vitro/in vivo antitrypanosomal activity of 3‐bromoacivicin was assessed in comparison with acivicin. Beyond expectation, we observed a 12‐fold enhancement in the in vitro antitrypanosomal activity, while toxicity against mammalian cells remained unaffected. Despite its good in vitro activity and selectivity, 3‐bromoacivicin proved to be trypanostatic and failed to completely eradicate the infection when tested in vivo at its maximum tolerable dose.
X‐Ray Near‐Edge Absorption Study of Temperature‐Induced Low‐Spin‐to‐High‐Spin Change in Metallo‐Supramolecular Assemblies
Authors: Arezki Bahia , Schwarz Guntram , Bodenthin Yves , Luetzenkirchen‐Hecht Dirk , Markert Christian , Wagner Ralph , Frahm Ronald , Kurth Dirk G. , Pietsch Ullrich
Published: December 2010

X‐ray absorption near the iron K edge (XANES) was used to investigate the characteristics of temperature‐induced low‐spin‐to‐high‐spin change (SC) in metallo‐supramolecular polyelectrolyte amphiphile complexes (PAC) containing FeN6 octahedra attached to two or six amphiphilic molecules. Compared to the typical spin‐crossover material Fe(phen)2(NCS)2 XANES spectra of PAC show fingerprint features restricted to the near‐edge region which mainly measures multiple scattering (MS) events. The changes of the XANES profiles during SC are thus attributed to the structure changes due to different MS path lengths. Our results can be interpreted by a uniaxial deformation of FeN6 octahedra in PAC. This is in agreement with the prediction that SC is originated by a structural phase transition in the amphiphilic matrix of PAC, but in contrast to Fe(phen)2(NCS)2, showing the typical spin crossover being associated with shortening of all the metal–ligand distances.
Use of Polyoxometalate Catalysts in Ionic Liquids to Enhance the Dissolution and Delignification of Woody Biomass
Authors: Sun Ning , Jiang Xinyu , Maxim Mirela L. , Metlen Andreas , Rogers Robin D.
Published: December 2010

A well‐known polyoxometalate, [PV2Mo10O40]5−, in both acidic (acidic POM, H5[PV2Mo10O40]) and ionic liquid‐compatible form ([C2mim]POM, [1‐ethyl‐3‐methylimidazolium]4H[PV2Mo10O40]), has been studied as a catalyst for the dissolution and delignification of wood in the ionic liquid (IL) 1‐ethyl‐3‐methylimidazolium acetate ([C2mim]OAc). Differences were observed with variables such as the form of POM, POM loading, and reaction conditions. Generally, the addition of POM leads to a faster dissolution, a lower lignin content in the recovered cellulose‐rich materials (isolated pulp), and a lower isolated yield of lignin due to its oxidation. Acidic POM decreases the lignin content of the pulp without compromising the yield of the pulp. [C2mim]POM in the IL facilitates greater delignification (lower lignin content in pulp) than the IL with acidic POM; however, the overall pulp yield is also lower indicating some degradation of the carbohydrates. The POM can be recovered with [C2mim]OAc after evaporation of the reconstitution solvent (e.g., acetone/water) and can be reused, albeit with some loss of POM and loss of POM activity under the current conditions.
Substrate‐Dependant Ability of Titanium(IV) Oxide Photocatalytic Thin Films Prepared by Thermal CVD to Generate Hydrogen Gas from a Sacrificial Reaction
Authors: Hyett Geoffrey , Darr Jawwad A. , Mills Andrew , Parkin Ivan P.
Published: December 2010

We report the observation of hydrogen production from photodiodes, when irradiated with UV light. These photodiodes were composed of a stainless steel substrate, with a TiO2 photocatalyst deposited suing APCVD on one side and Pt deposited using sputter coating on the other. In contrast similar devices made using a titanium substrate show no measurable H2 production.
Fabrication of La0.8Sr0.2CrO3‐based Perovskite Film via Flame‐Assisted Vapor Deposition for H2 Production by Reforming
Authors: Sansernnivet Mayuree , Laosiripojana Navadol , Assabumrungrat Suttichai , Charojrochkul Sumittra
Published: December 2010

Flame‐assisted vapor deposition (FAVD) has a principle similar to conventional CVD in which a film is deposited from a vapor phase. It is a simple and cost‐effective technique as it is operated in an open atmosphere. The microstructure of the deposited films is controlled by varying the processing parameters. In our research, an oxide film of lanthanum chromite perovskite‐based (La0.8Sr0.2CrO3) material is fabricated, using the FAVD technique, on a stainless steel substrate (SS430) for an application in solid oxide fuel cells (SOFC). The precursor solution for La0.8Sr0.2CrO3 film is prepared from metal nitrate compounds with a concentration in the range 0.0125 − 0.0500 M. Dense and porous films are fabricated, depending on various processing parameters such as fuel to water ratio, air pressure, flow rate of a precursor, and the distance between the spray nozzle and the substrate. The effect of various processing parameters on the microstructure and phase formation of the deposited film are investigated using scanning electron microscopy (SEM) and X‐ray diffraction (XRD). The deposition temperature resulting from the total heat of combustion from the combination of all the deposition parameters is very important in determining the properties of the films. According to the SEM images, a small particle size on the nanometer scale is found at high deposition temperature. On the other hand, the particles are connected into a dense film at low deposition temperatures. The main phase of LaCrO3 is found in all deposition temperatures (temp range). For hydrogen production, the methane steam reforming over the porous film of La0.8Sr0.2CrO3 at 900 °C is investigated. Under specific operating conditions (low inlet H2O/CH4 ratio), its catalytic reactivity is comparable to metallic‐based catalysts but with less inlet steam required.
Coordination Chemistry of Thiazole‐Based Ligands: New Complexes Generating 3D Hydrogen‐Bonded Architectures
Authors: Rossin Andrea , Di Credico Barbara , Giambastiani Giuliano , Gonsalvi Luca , Peruzzini Maurizio , Reginato Gianna
Published: December 2010

The hydrothermal (solvothermal) reactions of ZnII, CoII, and CuII salts with the thiazole‐based ligands 2‐Htzc (thiazole‐2‐carboxylic acid), 4‐Htzc (thiazole‐4‐carboxylic acid), and Htzc‐py [2‐(2‐pyridyl)thiazole‐4‐carboxylic acid] led to the formation of coordination complexes with assorted geometry at the metal centers. The new complexes were characterized by conventional spectroscopic methods as well as by single‐crystal X‐ray analysis, TG–MS, and PXRD. Crystallographic studies have shown that an extended supramolecular network is generated in the solid state through the formaton of hydrogen bonds between the several polar groups present in the complex frameworks.
Synthesis, Structures, and Aggregation Properties of N‐Acylamidines
Authors: Wigbers Christof , Prigge Jörg , Mu Zhongchen , Fröhlich Roland , Chi Lifeng , Würthwein Ernst‐Ulrich
Published: December 2010

N‐Acylamidines 1a–q, which are important ligands for metal ion complexation, were easily prepared either by acylation of amidines 2 or by treatment of N‐acylimidates 3 with amines. Additionally, the reaction of amidinium salts with aroyl halides in the presence of sodium hydroxide gave the aryl derivatives 1r–1ad and three azobenzene derivatives 1ae–1ag. The respective substitution pattern of these novel derivatives was selected with respect to possible steric and electronic effects in coordination reactions as well as with regard to the aggregation properties. N‐Acylamidines 1 may exist as three types of tautomers, which were examined in solution by NMR spectroscopic analysis and by quantum chemical DFT and SCS‐MP2‐calculations for single molecules in the gas phase. Internal rotations require activation energies between 3–17 (C–N) and 15–27 (C=N) kcal/mol. Due to their excellent ability to form intra‐ and intermolecular hydrogen bonds, these molecules show very variable aggregation behavior in the solid state (X‐ray analysis) as well as on surfaces, depending on the substitution pattern. Thus, dimeric (1c, 1d, and 1u) and tetrameric (1f) aggregates with strong NH···OC hydrogen bonding, as well as polymeric chain structures (1x and 1z) were observed in the solid state. Furthermore, a dimer 1k involving only the amidine subunits, rather than the carbonyl function, was found. Monolayers of molecules 1u and 1ab physisorbed at the liquid/HOPG (high orientated pyrolytic graphite) interface in 1‐phenyloctane solution were examined by Scanning Tunneling Microscopy (STM).
Peptide–Heterocycle Chimera: New Classes of More Drug‐Like Peptidomimetics by Ligations of Peptide–Bis(electrophiles) with Various Bis(nucleophiles)
Authors: El‐Dahshan Adeeb , Nazir Samina , Ahsanullah  , Ansari Farzana Latif , Rademann Jörg
Published: December 2010

Several C‐terminal peptidyl‐substituted bis‐ and tris(electrophiles) were prepared by starting from polymeric phosphoranylidenacetates as acyl anion equivalents. After C‐acylations with amino acids and peptide elongation, the obtained peptidyl‐phosphoranylideneacetate resins were either cleaved oxidatively, delivering peptidyl‐diketo esters, or saponified, leading to immediate decarboxylation. The generated peptidyl‐phosphorane could be treated with aldehydes to yield peptidyl vinyl ketones or could be cleaved oxidatively to yield peptidyl keto aldehydes. Ligation with various bis(nucleophiles) including hydrazines, hydroxylamine, diamines, amino‐thiols, amidines, and guanidines were investigated in the formation of peptide‐heterocycle chimera containing pyrazoline, pyrazole, isoxazole, isoxazoline, thiazepine, quinoxaline, and imidazolone heterocycles.
Photochemical Reactions of Chloranil with Cyclooctene, 1,5‐Cyclooctadiene, and Cyclohexene Revisited
Authors: Christl Manfred , Braun Max , Deeg Oliver , Wolff Stephan
Published: December 2010

Depending on the reaction conditions, excited chloranil (3CA) and cis‐cyclooctene (cis‐CO) furnished three types of products, which all contain carbocyclic four‐membered rings. The illumination of a solution in benzene by light bulbs gave rise to the all‐cis 1:1 cycloadduct (11a) in 76 % yield. On its part, this compound reacted with cis‐CO under the action of better sources for UV light with the formation of three isomeric 1:2 cycloadducts. Two of them underwent a photochemical dechlorination leading to a cyclobutene derivative. Albeit rather sluggishly, 3CA and trans‐cyclooctene (trans‐CO) brought about an unsymmetrical 1:1 and a 1:2 cycloadduct. By contrast, excited 11a reacted smoothly with trans‐CO and afforded a 72 % yield of the unsymmetrical 1:2 cycloadduct that resulted from 3CA and cis‐CO in addition to two symmetrical 1:2 cycloadducts. Also, excited 11a and cyclohexene (CH) furnished a bis(cyclobutane) derivative, a significant portion of which was subject to a dechlorination to give a cyclobutene derivative. cis,cis‐1,5‐Cyclooctadiene (COD) and CH were transformed by 3CA to 1:1 and 1:2 cycloadducts, analogous to cis‐ and trans‐CO. In addition to this, 3CA suffered photoreduction in the presence of COD and CH. The [2+2] cycloaddition onto a carbonyl group of 3CA with formation of a spirooxetane occurred to a small extent only with COD, but not at all with cis‐ and trans‐CO and CH.
Square Wave Voltammetric Determination of Lead(II) Ions Using a Carbon Paste Electrode Modified by a Thiol‐Functionalized Kaolinite
Authors: Tonlé Ignas K. , Letaief Sadok , Ngameni Emmanuel , Walcarius Alain , Detellier Christian
Published: December 2010

This work reports the electroanalysis of lead(II) in aqueous medium, using a carbon paste electrode modified by a novel thiol‐functionalized clay. This later was obtained upon the grafting of 3‐chloropropyltriethoxysilane onto the interlayer surfaces of kaolinite, followed by the substitution under carefully controlled conditions of chloro by thiol groups. The raw kaolinite, its dimethylsulfoxide (DMSO) intercalate used as starting material and the resulting hybrids were characterized by X‐ray diffraction, thermal analysis, infrared spectroscopy and CHNS elemental analysis. These techniques demonstrated the displacement of DMSO by the organosilane molecules which were grafted on the internal hydroxyl groups located on the kaolinite surface. The final functionalized kaolinite, with approximate chemical formula Si4Al4O10(OH)6[O2Si(OEt)(CH2)3SH] was evaluated as electrode modifier for lead(II) sensing. A two‐step analytical procedure based on the accumulation at open circuit–detection was applied by square wave voltammetry. Various parameters affecting both the two steps were optimized: a linear response to lead(II) was obtained in the concentration range from 3×10−7 to 10−5 M, with a detection limit estimated at 6×10−8 M. The interfering effect of some ions likely to influence the stripping determination of lead(II) ions was evaluated, and the proposed method applied to a real sample.
Voltammetry and Spectroscopy Study of In Vitro Interaction of Fenitrothion with DNA
Authors: Ahmadi Farhad , Jafari Batool
Published: December 2010

The interaction of Fenitrothion with DNA has been studied using the voltammetric and spectroscopic methods. An irreversible reduction was concluded from the CV data of Fenitrothion. The values of (αn)f=1.91 and (αn)b=2.06 were measured and the reduction process of Fenitrothion was performed with 4 electrons. By using non‐linear regression analysis of CV data, the binding constant, binding site size, and diffusion coefficient for free Fenitrothion (Df) and DNA‐Fenitrothion (Db) were calculated as: 1.03×104, 1.204, 5.2×10−4 and 1.72×10−5, respectively. Also the voltammetric, spectroscopic, thermodynamic and activation energy of DNA‐Fenitrothion complex revealed that the mode of interaction might be partial‐intercalative and complex formation is entropy favored.
Catalytic Adsorptive Stripping Voltammetry of Cobalt in the Presence of Nitrite at an In Situ Plated Bismuth Film Electrode
Authors: Rutyna Iwona , Korolczuk Mieczysław
Published: December 2010

For the first time an in situ plated bismuth film electrode has been applied to catalytic adsorptive stripping voltammetry of cobalt in the presence of nitrite. At optimised conditions bismuth film was plated before each measurement for 30 s at −1.0 V from a sample solution with the added supporting electrolyte and Bi(III) in the form of its complex with tartrate. The calibration graph for Co(II) for an accumulation time of 120 s was linear from 5×10−10 to 1×10−8 mol L−1. The detection limit was 1.1×10−10 mol L−1. The proposed procedure was applied for Co(II) determination in certified water reference material.
Anxiety positive subjects show altered processing in the anterior insula during anticipation of negative stimuli
Authors: Simmons Alan N. , Stein Murray B. , Strigo Irina A. , Arce Estibaliz , Hitchcock Carla , Paulus Martin P.
Published: December 2010

Prior neuroimaging studies support the hypothesis that anticipation, an important component of anxiety, may be mediated by activation within the insular and medial prefrontal cortices including the anterior cingulate cortex. However, there is an insufficient understanding of how affective anticipation differs across anxiety groups in emotional brain loci and networks. We examined 14 anxiety positive (AP) and 14 anxiety normative (AN) individuals completing an affective picture anticipation task during functional magnetic resonance imaging (fMRI). Brain activation was examined across groups for cued anticipation (to aversive or pleasant stimuli). Both groups showed greater activation in the bilateral anterior insula during cued differential anticipation (i.e., aversive vs. pleasant), and activation on the right was significantly higher in AP compared to AN subjects. Functional connectivity showed that the left anterior insula was involved in a similar network during pleasant anticipation in both groups. The left anterior insula during aversive and the right anterior insula during all anticipation conditions coactivated with a cortical network consisting of frontal and parietal lobes in the AP group to a greater degree. These results are consistent with the hypothesis that anxiety is related to greater anticipatory reactivity in the brain and that there may be functional asymmetries in the brain that interact with psychiatric traits. Hum Brain Mapp, 2011. © 2010 Wiley‐Liss, Inc.
Clinical functional MRI of the language domain in children with epilepsy
Authors: Wilke Marko , Pieper Tom , Lindner Katja , Dushe Thekla , Staudt Martin , Grodd Wolfgang , Holthausen Hans , Krägeloh‐Mann Ingeborg
Published: December 2010

Functional MRI (fMRI) for the assessment of language functions is increasingly used in the diagnostic workup of patients with epilepsy. Termed “clinical fMRI,” such an approach is also feasible in children who may display specific patterns of language reorganization. This study was aimed at assessing language reorganization in pediatric epilepsy patients, using fMRI. We studied 26 pediatric epilepsy patients (median age, 13.05 years; range, 5.6–18.7 years) and 23 healthy control children (median age, 9.37 years; range, 6.2–15.4 years), using two child‐friendly fMRI tasks and adapted data‐processing streams. Overall, 81 functional series could be analyzed. Reorganization seemed to occur primarily in homotopic regions in the contralateral hemisphere, but lateralization in the frontal as well as in the temporal lobes was significantly different between patients and controls. The likelihood to find atypical language organization was significantly higher in patients. Additionally, we found significantly stronger activation in the healthy controls in a primarily passive task, suggesting a systematic confounding influence of antiepileptic medication. The presence of a focal cortical dysplasia was significantly associated with atypical language lateralization. We conclude that important confounds need to be considered and that the pattern of language reorganization may be distinct from the patterns seen in later‐onset epilepsy. Hum Brain Mapp, 2011. © 2010 Wiley‐Liss, Inc.
Highly unsaturated phosphorus compounds: Trimeric and dimeric sulfides of a α,β‐di‐tert‐butyl vinyl phosphaalkyne
Authors: Ionkin Alex S. , Marshall William J. , Fish Brian M.
Published: December 2010

The first examples of sulfides of a 1,3,5‐triphosphabenzene were synthesized by the sulfurization of parent 1,3,5‐triphosphabenzene 2. Disulfide 7 was found to be remarkably thermally stable, the stability likely coming from the contribution of resonance forms 7A and 7B. In addition to two hydrolysis products of trisulfide 8, which can be anticipated in unsaturated phosphorus chemistry, a new and not trivial bicyclic bridgehead five‐membered heterocycle 10 was isolated among the decomposition products of 8. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 22:114–118, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20664
The Slow‐Release Strategy in Suzuki–Miyaura Coupling
Authors: Lennox Alastair J. J. , Lloyd‐Jones Guy C.
Published: December 2010

Despite great advances in metal‐catalyzed cross‐coupling reactions, their efficacy is often compromised by side reactions, reducing the yield, or requiring a large excess of one component. Suzuki–Miyaura cross‐coupling is no exception, as the boronic acid functionality can be susceptible to a range of undesired processes. A number of methods have been developed to mitigate these side reactions, and herein we focus on the “slow‐release” strategy. These conditions involve deployment of a “masking” reagent that protects the vulnerable boronic acid functionality from degradation, particularly protodeboronation, whilst simultaneously facilitating controlled liberation of the active reagent into the catalytic milieu. Under suitably tailored conditions, this dual‐action approach ensures that the concentration of the free boronic acid is minimized, thus attenuating its degradation but still facilitating transmetallation of the organoboron species with the key organopalladium intermediate.
One‐pot synthesis of pyrano‐ and furanoquinolines catalyzed by molten tetra‐n‐butylphosphonium bromide under solvent‐free conditions
Authors: Salehi Javad , Veisi Hojat , Khodaei Mohammad M. , Khosropour Ahmad R.
Published: December 2010

Molten tetra‐n‐butylphosphonium bromide is found to be a practical and inexpensive catalytic media for stereoselective one‐pot synthesis of pyranoquinoline and furanoquinoline derivatives in good to excellent yields. Products of undesirable reactions resulting from polymerization are not observed. The use of this catalyst media avoids the use of any cocatalysts or toxic organic solvents. J. Heterocyclic Chem., (2011).
Interactive 3D anatomy and affinities of Bathysciadiidae (Gastropoda, Cocculinoidea): deep‐sea limpets feeding on decaying cephalopod beaks
Authors: Hartmann Heike , Heß Martin , Haszprunar Gerhard
Published: December 2010

The anatomy of five bathysciadiid limpets, the type species Bathysciadium costulatum (Locard, 1898), Bathysciadium sp. B (off New Zealand), Bathypelta pacifica (Dall, 1908), Bathypelta sp. A (off New Zealand), and Bathyaltum wareni n.g., n.sp. (deep East Atlantic Ocean Basins), which all feed on decaying cephalopod beaks, has been investigated by means of semithin serial sectioning and interactive, computer‐aided 3D reconstructions. Bathyaltum wareni is described as a species new to science based on additional SEM photos of shell and radula. Differences between species are found in conditions of shell, protoconch, mantle papilla, copulatory organ, receptaculum openings, oral lappets, and rectal histology. The Bathysciadiidae share several synapomorphies with the Cocculinidae (s. str.), namely the pseudoplicatid gill, a single, left kidney, the hermaphroditic gonad with the single, glandular gonoduct, and the statocysts with single statoliths. Therefore, these families are united in a clade Cocculinoidea, which is considered to be highly modified offshoot of early gastropods independent of the likewise “cocculiniform” Lepetelloidea, which should be classified among the Vetigastropoda. J. Morphol. 272:259–279, 2011. © 2010 Wiley‐Liss, Inc.
Detection of human parechovirus in stool samples collected from children with acute gastroenteritis in Japan during 2007–2008
Authors: Pham Ngan Thi Kim , Chan‐It Wisoot , Khamrin Pattara , Nishimura Shuichi , Kikuta Hideaki , Sugita Kumiko , Baba Tsuneyoshi , Yamamoto Atsuko , Shimizu Hideaki , Okitsu Shoko , Mizuguchi Masashi , Ushijima Hiroshi
Published: December 2010

Of 477 stool specimens, which had been screened for rotavirus, adenovirus, norovirus, sapovirus and astrovirus, collected from infants and children with acute gastroenteritis in pediatric clinics encompassing five localities (Sapporo, Tokyo, Maizuru, Osaka, and Saga) in Japan from July 2007 to June 2008, 247 negative samples (51.7%) were subjected to screening for human parechovirus. Human parechovirus (HPeV) was detected by RT‐PCR using a primer pair to amplify 5′UTR region of its genome and was genotyped by sequencing of the VP1 gene. HPeV was detected in 20 of 247 specimens tested, and the detection rate was found to be 8.1%. Seventeen of the 20 strains that tested positive for HPeV were sequenced successfully the VP1 gene. The majority of the HPeV strains (n = 15) could be identified as HPeV1, and the remaining 2 strains could be typed as HPeV3. By phylogenetic and identical matrix analyses of HPeV VP1 sequences, HPeV1 should be divided into two lineages, and all of the Japanese studied HPeV1 strains belong to the lineage 2 accordingly. This is the first report of the circulation of HPeV, especially HPeV1 in Japan. J. Med. Virol. 83:331–336, 2011. © 2010 Wiley‐Liss, Inc.
Prevalence of human coronaviruses in adults with acute respiratory tract infections in Beijing, China
Authors: Ren Lili , Gonzalez Richard , Xu Jin , Xiao Yan , Li Yongjun , Zhou Hongli , Li Jianguo , Yang Qingqing , Zhang Jing , Chen Lan , Wang Wei , Vernet Guy , Paranhos‐Baccalà Gláucia , Wang Zhong , Wang Jianwei
Published: December 2010

Human coronaviruses (HCoVs) are a common etiological agent of acute respiratory tract infections. HCoV infections, especially those caused by the two HCoVs identified most recently, NL63 and HKU‐1, have not been characterized fully. To evaluate the prevalence and clinical presentations of HKU1 and NL63 in adults with acute respiratory tract infections, an investigation of HCoV infections in Beijing, China from 2005 to 2009 was performed by using reverse transcriptase PCR assays and sequencing analysis. Among 8,396 respiratory specimens studied, 87 (1%) clinical samples were positive for HCoVs, of which 50 samples (0.6% of the total) were positive for HCoV‐OC43, 15 (0.2%) for HCoV‐229E, 14 (0.2%) for HCoV‐HKU1, and 8 (0.1%) for HCoV‐NL63. The prevalence of HCoV infection in adults exhibited distinct seasonal fluctuations during the study period. In addition, patients positive for HCoV‐229E infections were more likely to be co‐infected with other respiratory viruses. Enterovirus, rhinovirus, and parainfluenza virus type 3 were the most common viruses found in patients with HCoV infections. The demographic and clinical data present in this study of HCoV infections in adults with acute respiratory tract infections should improve our understanding of the pathogenesis of HCoVs. J. Med. Virol. 83:291–297, 2011. © 2010 Wiley‐Liss, Inc.
VP7 Gene of human rotavirus A genotype G5: Phylogenetic analysis reveals the existence of three different lineages worldwide
Authors: da Silva Marcelle Figueira Marques , Tort Luis Fernando López , Goméz Mariela Martínez , Assis Rosane Maria Santos , Volotão Eduardo de Mello , de Mendonça Marcos César Lima , Bello Gonzalo , Leite José Paulo Gagliardi
Published: December 2010

Group A rotavirus (RV‐A) genotype G5, which is common in pigs, was also detected in children with severe diarrhea in Brazil, Argentina, Paraguay, Cameroon, China, Thailand, and Vietnam. To evaluate the evolutionary relationship among RV‐A G5 strains, the VP7 and VP4 genes of 28 Brazilian RV‐A G5 human strains, sampled between 1986 and 2005, were sequenced and compared with other RV‐A G5 strains currently circulating worldwide in animals and humans. The phylogenetic analysis of RV‐A G5 VP7 gene strains demonstrates the existence of three main lineages: (a) Lineage I: Brazilian strains grouped with three porcine strains from Thailand; (b) Lineage II: porcine, bovine, and equine strains from different regions; (c) Lineage III: human strains isolated in Asia and Africa, and two porcine strains from Argentina. The VP8* (*non‐typable) subunit of VP4 gene sequencing showed that all P[8] strains fell into three major genetic lineages: P[8]‐1; P[8]‐2; and P[8]‐3. These results showed that the RV‐A G5 strains circulating in humans are the result of two independent zoonotic transmission events, most likely from pigs. J. Med. Virol. 83:357–366, 2011. © 2010 Wiley‐Liss, Inc.
Changes in the HIV‐1 mutational profile before first‐line HAART in the RESINA cohort
Authors: Reuter Stefan , Oette Mark , Sichtig Nadine , Kaiser Rolf , Balduin Melanie , Jensen Björn , Häussinger Dieter ,   for the RESINA study group
Published: December 2010

Sporadic observations have shown changing patterns of transmitted drug resistance mutations (TDRMs) in HIV infection even without selection pressure by antiretroviral treatment (ART). Repeated genotypic resistance analyses in treatment‐naïve patients were performed, in order to analyze intraindividual variances of resistance patterns over time. Between the years 2001 and 2008 two genotypic resistance tests were performed at different time‐points in 49 treatment‐naïve HIV‐positive patients aged >18 years. Wild‐type virus was found at baseline and during follow‐up in 31 patients (group A, median time between resistance tests 146 days), while resistance mutations were found either at baseline or during follow‐up in 18 patients (group B, median time between resistance tests 297 days). In group B, the pattern of resistance changed in eight out of 18 patients over time, with three patients showing decreasing numbers and five patients showing increasing numbers of resistance mutations. The pattern of resistance mutations remained unchanged in 10 out of 18 patients. The mutational pattern in untreated HIV infection may change over time and a single resistance analysis may underestimate the true prevalence of preserved resistance mutations. If these findings can be confirmed in a larger number of patients, it would be prudent to perform genotypic resistance testing both at baseline and prior to the start of ART in order to capture a more complete picture of preserved mutations before initiating ART. J. Med. Virol. 83:187–195, 2011. © 2010 Wiley‐Liss, Inc.