bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ionization‐Induced Solvent Migration in Acetanilide‐Methanol Clusters Inferred from Isomer‐Selective Infrared Spectroscopy
Authors: Weiler Martin , Nakamura Takashi , Sekiya Hiroshi , Dopfer Otto , Miyazaki Mitsuhiko , Fujii Masaaki 
Published: October 2012

AbstractWe present the resonance‐enhanced multiphoton ionization, infrared‐ultraviolet hole burning (IR‐UV HB), and IR dip spectra of the trans‐acetanilide–methanol (AA–MeOH) cluster in the S0, S1, and cationic ground state (D0) in a supersonic jet. The IR‐UV HB spectra demonstrate the co‐existence of two isomers in S0,1, in which MeOH binds either to the NH or the CO site of the peptide linkage in AA, denoted as AA(NH)–MeOH and AA(CO)–MeOH. When AA(CO)–MeOH is selectively ionized, its IR spectrum in D0 is the same as that measured for AA+(NH)–MeOH. Thus, photoionization of AA(CO)–MeOH induces migration of MeOH from the CO to the NH site with 100% yield.
New detection algorithms based on the jointly Gaussian approach and successive interference cancelation for iterative MIMO systems
Authors: Wu Jie , Zhong Jie , Cai Yunlong , Zhao Minjian , Zhang Wenyan 
Published: October 2012

SUMMARYA new detection algorithm based on the jointly Gaussian approach (JGA) and successive interference cancelation (SIC), named the SIC‐JGA algorithm, is proposed for iterative MIMO systems. Both the a priori symbol estimates of the undetected layers and the a posteriori symbol estimates of the previously detected layers are used in the SIC process. To reduce the complexity of covariance matrix inversion in the proposed algorithm, simplified algorithms named S‐SIC‐JGA are investigated for both the single path and multipath block fading channels under M Phase Shift Keying modulations. A detailed complexity analysis is presented for both the SIC‐JGA and S‐SIC‐JGA algorithms. Numerical results exhibit that the system using the SIC‐JGA algorithm outperforms the JGA algorithm, with an additional complexity for determining the detection order of SIC. The S‐SIC‐JGA algorithm has a much lower complexity compared with the SIC‐JGA algorithm while experiencing an acceptable system performance degradation. Proper detection algorithms can be chosen in different iterations to balance the system performance and the detection complexity. Copyright © 2012 John Wiley & Sons, Ltd.
An authentication and key agreement protocol for satellite communications
Authors: Chang Chin‐Chen , Cheng Ting‐Fang , Wu Hsiao‐Ling 
Published: October 2012

SUMMARYIn 2009 and 2011, Chen et al. and Lasc et al. proposed two separate authentication schemes for mobile satellite communication systems. Unfortunately, their schemes are unable to protect security in the event of smart card loss. In this paper, we propose a novel version that resists common malicious attacks and improves both the schemes of Chen et al. and Lasc et al. The security of our scheme is based on the discrete logarithm problem and one‐way hash function. A nonce mechanism is also applied to prevent replay attack. Furthermore, our scheme is more efficient than related schemes and thus more suitable for being implemented in satellite communication systems. Copyright © 2012 John Wiley & Sons, Ltd.
Cellular IP address provisioning in a heterogeneous wireless network
Authors: Khair Mazen G. , Kantarci Burak , Mouftah Hussein T. 
Published: October 2012

SUMMARYIn this article, we propose a dynamic Internet Protocol (IP) address assignment architecture for heterogeneous wireless IP devices network. The IP device could be a sensor device, a laptop, a cell phone, or any wireless device using IP communications. The proposed architecture introduces security and service reliability to the consumer while reducing the operational expenditure for the service providers. According to the proposed scheme, each node maintains an IP address pool storing the current occupancy of each IP address. Each node advertises its database whenever the ratio of negative acknowledgments from the domain name server to the total number of requests at a given node exceeds a certain threshold. We evaluate our IP assignment scheme under two traffic intensity scenarios, namely the uniform traffic intensity and the heterogeneous traffic intensity. Performance evaluation is carried out with respect to blocking probability and average IP list utilization. We define three types of blocking probability for the user requests as follows: The real blocking, the unjustified acceptance, and the unjustified rejection. We observe that the proposed scheme outperforms the uniform assignment as long as the threshold is below 1.5% for the uniform intensity scenario and 1% for the heterogeneous scenario. Furthermore, this architecture considers the security aspect of the wireless network by allowing only registered devices to communicate with other registered devices. Copyright © 2012 John Wiley & Sons, Ltd.
Generation of a conditional mouse model to target Acvr1b disruption in adult tissues
Authors: Ripoche Doriane , Gout Johann , Pommier Roxane M. , Jaafar Rami , Zhang Chang X. , Bartholin Laurent , Bertolino Philippe 
Published: October 2012

AbstractAlk4 is a type I receptor that belongs to the transforming growth factor‐beta (TGF‐β) family. It takes part in the signaling of TGF‐β ligands such as Activins, Gdfs, and Nodal that had been demonstrated to participate in numerous mechanisms ranging from early embryonic development to adult‐tissue homeostasis. Evidences indicate that Alk4 is a key regulator of many embryonic processes, but little is known about its signaling in adult tissues and in pathological conditions where Alk4 mutations had been reported. Conventional deletion of Alk4 gene (Acvr1b) results in early embryonic lethality prior gastrulation, which has precluded study of Alk4 functions in postnatal and adult mice. To circumvent this problem, we have generated a conditional Acvr1b floxed‐allele by flanking the fifth and sixth exons of the Acvr1b gene with loxP sites. Cre‐mediated deletion of the floxed allele generates a deleted allele, which behaves as an Acvr1b null allele leading to embryonic lethality in homozygous mutant animals. A tamoxifen‐inducible approach to target disruption of Acvr1b specifically in adult tissues was used and proved to be efficient for studying Alk4 functions in various organs. We report, therefore, a novel conditional model allowing investigation of biological role played by Alk4 in a variety of tissue‐specific contexts. genesis 51:120–127, 2013. © 2012 Wiley Periodicals, Inc.
Trends in 20th century global rainfall interception as simulated by a dynamic global vegetation model: implications for global water resources
Authors: Murray S. J. 
Published: October 2012

ABSTRACTThe Land‐surface Processes and eXchanges Dynamic Global Vegetation Model (LPX‐DGVM, one of several developments of the Lund–Potsdam–Jena (LPJ) model) is evaluated in terms of its interception component and used to simulate trends in 20th century global relative throughfall from natural vegetation. Mean global annual runoff is estimated to have been reduced by 163 ± 19 km3 year−1 between 1901 and 2006 as a result of biophysical changes controlling throughfall generation. Widespread decreases in relative throughfall of up to −1% are evident between the periods 1901–1953 and 1954–2006, while changes of up to −15% are shown in parts of North America and East Asia. Areas of simulated decrease in relative throughfall often lie in close proximity to areas of increase, reflecting the effects of vegetation shifts.It is shown that simulated global absolute throughfall has generally increased (because of increasing precipitation) during the studied period, but the curtailing of runoff caused by decreased relative throughfall (as a result of increased fractional plant coverage and possible vegetation shifts) has caused a slight exacerbation of water stress in some regions (including parts of East Asia, North America and the tropics) and increased water supplies in others (for example, other parts of the tropics and northern Russia). This study offers an initial insight into an often overlooked product of climate‐induced vegetation changes and attempts to quantify how these responses may contribute to influencing the global freshwater budget and global water resources. Copyright © 2012 John Wiley & Sons, Ltd.
Structure Determination of γ‐Brass‐Related Composite Structures in the Ni–Zn System: A Guided Tour by a (3+1)‐Dimensional Space Description
Authors: Jana Partha Pratim , Lidin Sven 
Published: October 2012

AbstractThree incommensurately modulated γ‐brass‐related composite structures in the Ni–Zn system have been solved from X‐ray single crystal diffraction data using a 3+1 dimensional super space description. The compounds at the end points of the compositional domain NiZn3–δ (–0.09 ≤ δ ≤ 0.34) and NiZn3.30 crystallize in the orthorhombic superspace group Fmmm(α00)0s0 {F = [(1/2, 1/2, 0, 0); (1/2, 0, 1/2, 0); (0, 1/2, 1/2, 0)]} with the following fundamental cell dimensions a = 4.165(1) Å, b = 8.883(2) Å, c = 12.545(3) Å, q ≈ 0.6311a*; a = 4.161(2) Å, b = 8.876(3) Å, c = 12.535(4) Å, q ≈ 0.6314a* and a = 4.177(2) Å, b = 8.899(1) Å, c = 12.570(2) Å, q ≈ 0.6378a*.
Biologically Active Trifluoromethyl‐Substituted Metallocene Triazoles: Characterization, Electrochemistry, Lipophilicity, and Cytotoxicity
Authors: Maschke Marcus , Lieb Max , Metzler‐Nolte Nils 
Published: October 2012

AbstractWe report the facile synthesis of four different trifluoromethylated metallocene triazoles and their biological evaluation (M = Fe and Ru). The cytotoxicity of all compounds was evaluated using MCF‐7, HT‐29, PT‐45 and GM5657 cells and IC50 values as low as 33 μM were found. It was shown that the metallocene moiety is crucial for the cytotoxic effect. The electrochemical behavior of triazoles 3–6 was investigated by cyclic voltammetry. These electrochemical measurements revealed that all triazoles are less prone to oxidation than ferrocene. Moreover, Log P determination by RP‐HPLC showed increased lipophilicity for the fluorinated derivatives with Log P values up to 3.8. Furthermore, successful bioconjugation could be achieved by coupling triazole 7 to the amino acid L‐leucine.
Epoxidation of 4‐Alkylidenecyclopentenones: A Route to the 1‐Oxaspiro[2.4]hept‐6‐en‐5‐one Framework
Authors: Ahmar Mohammed , Thomé Stéphane , Cazes Bernard 
Published: October 2012

AbstractThanks to their lack of polarity, the exocyclic double bonds of 4‐alkylidenecyclopentenones 4 are selectively epoxidized by MCPBA to give spiroepoxycyclopentenones 7, which feature the nonclassical 1‐oxaspiro[2.4]hept‐6‐en‐5‐one framework. Under acidic conditions, compounds 7 undergo ring‐opening to afford 4‐hydroxy‐4‐(1‐hydroxyalkyl)cyclopentenones 10.
The Proton Sponge Effect: Substitution of Quino[7,8‐h]quinoline and the First Structurally Characterised Derivatives
Authors: Shaffer Karl J. , Parr Daniel C. , Wenzel Marco , Rowlands Gareth J. , Plieger Paul G. 
Published: October 2012

AbstractA new route to unsymmetrical derivatives of quino[7,8‐h]quinoline was developed. Substitutions at the 2,11‐, 4,9‐ and 6,7‐positions of quino[7,8‐h]quinoline were also successfully performed. X‐ray crystal structure determinations of the resulting products revealed the propensity for derivatives of this molecule to exist in either stabilised keto or imino forms as a result of the formation of a strong intramolecular N–H···N hydrogen bond.
Direct and Stereoselective Alkylation of Nitro Derivatives with Activated Alcohols in Trifluoroethanol
Authors: Petruzziello Diego , Gualandi Andrea , Grilli Stefano , Cozzi Pier Giorgio 
Published: October 2012

AbstractHerein we disclose the simple, effective, and practical alkylation of nitroalkanes that takes place with benzylic, benzhydrylic, and propargylic alcohols in trifluoroethanol. A variety of different nitroalkanes bearing functional groups can be used in this SN1‐type reaction to afford the desired products in quantitative yields. Different chiral nitro derivatives were submitted to this highly diastereoselective alkylation reaction with selected benzhydrols. A new, effective, and chiral pyrrolidine organocatalyst was prepared by using this methodology.
Assessment of Cell Viability Using the Chronoamperometric Method Based on Screen‐Printed Electrodes
Authors: Tsai Hweiyan , Tsai Shang‐heng , Deng Hwei‐wen , Bor Fuh C. 
Published: October 2012

AbstractThis study investigates suitable electrochemical mediators and optimal mediator concentration for breast cancer cells, MDA‐MB‐231. The optimized mediators were 1 mM ferricyanide and 10 µM menadione. The specifications for the chronoamperometric detection of ferrocyanide were a linear range of 0.02–0.36 mM. The detection limit was 5.0 µM and the spiked recovery was 95 %–99 %. The oxidation currents increased linearly with cultured cell density. Cell viabilities determined using electrochemical methods confirmed those determined by MTT assay. The running time can be reduced to less than 30 min. The chronoamperometric method can be used as an alternative method for rapidly assessing the viability of breast cancer cells.
Highly Stable Polymeric Ionic Liquid Modified Electrode to Immobilize Ferricyanide for Electroanalysis of Sulfide
Authors: Chang Jen‐Lin , Wei Guor‐Tzo , Chen Tsu‐Yin , Zen Jyh‐Myng 
Published: October 2012

AbstractWe report here the preparation and application of a highly stable polymeric ionic liquid‐modified electrode to immobilize ferricyanide for sulfide analysis. Good long‐term stability of the modified electrode verifies its potential in sensor applications. The electrocatalytic sulfide oxidation signal at ∼0.0 V vs. Ag/AgCl in pH 7 PBS at the modified electrode was used for sulfide detection by hydrodynamic chronoamperometry and a detection limit of 12.9 nM (S/N=3) was obtained. Practical utility of the system is applied to the determination of sulfide content in hot spring water and ground water.
Carbon Cloth/Carbon Nanotube Electrodes for Biofuel Cells Development
Authors: Haddad Raoudha , Xia Wei , Guschin Dmitrii A. , Pöller Sascha , Shao Minling , Vivekananthan Jeevanthi , Muhler Martin , Schuhmann Wolfgang 
Published: October 2012

AbstractCarbon nanotubes (CNTs) grown on carbon cloth substantially increased the surface area of the electrodes. Carbon cloths were pretreated with HNO3 vapor before CNTs growth and electrochemically oxidized afterwards. The CNT‐modified carbon cloths were characterized using scanning electron microscopy, Raman spectroscopy, cyclic voltammetry and electrochemical impedance spectroscopy. Biofuel cells based on these CNT‐modified electrode materials using Laccase from Trametes hirsuta and cellobiose dehydrogenase from Myriococcum thermophilium entrapped in specifically designed Os‐complex modified redox polymers showed a power density of 5.87 µW/cm2 which is 125 fold enhanced as compared with electrodes prepared on untreated carbon cloth.
Different strategies for the preconcentration and separation of parabens by capillary electrophoresis
Authors: Maijó Irene , Borrull Francesc , Aguilar Carme , Calull Marta 
Published: October 2012

Several strategies, namely, large volume sample stacking (LVSS), field‐amplified sample injection (FASI), sweeping, and in‐line SPE‐CE, were investigated for the simultaneous separation and preconcentration of a group of parabens. A BGE consisting of 20 mM sodium dihydrogenphosphate (pH 2.28) and 150 mM SDS with 15% ACN was used for the separation and preconcentration of the compounds by sweeping, and a BGE consisting of 30 mM sodium borate (pH 9.5) was used for the separation and preconcentration of the compounds by LVSS, FASI, and in‐line SPE‐CE. Several factors affecting the preconcentration process were investigated in order to obtain the maximum enhancement of sensitivity. The LODs obtained for parabens were in the range of 18–27, 3–4, 2, and 0.01–0.02 ng/mL, and the sensitivity evaluated in terms of LODs was improved up to 29‐, 77‐, 120‐, and 18 400‐fold for sweeping, LVSS, FASI, and in‐line SPE‐CE, respectively. These preconcentration techniques showed potential as good strategies for focusing parabens. The four methods were validated with standard samples to show the potential of these techniques for future applications in real samples, such as biological and environmental samples.
A probabilistic performance‐based approach for mitigating the seismic pounding risk between adjacent buildings
Authors: Barbato M. , Tubaldi E. 
Published: October 2012

ABSTRACTExisting design procedures for determining the separation distance between adjacent buildings subjected to seismic pounding risk are based on approximations of the buildings' peak relative displacement. These procedures are characterized by unknown safety levels and thus are not suitable for use within a performance‐based earthquake engineering framework.This paper introduces an innovative reliability‐based methodology for the design of the separation distance between adjacent buildings. The proposed methodology, which is naturally integrated into modern performance‐based design procedures, provides the value of the separation distance corresponding to a target probability of pounding during the design life of the buildings. It recasts the inverse reliability problem of the determination of the design separation distance as a zero‐finding problem and involves the use of analytical techniques in order to evaluate the statistics of the dynamic response of the buildings. Both uncertainty in the seismic intensity and record‐to‐record variability are taken into account.The proposed methodology is applied to several different buildings modeled as linear elastic single‐degree‐of‐freedom (SDOF) and multi‐degree‐of‐freedom (MDOF) systems, as well as SDOF nonlinear hysteretic systems. The design separation distances obtained are compared with the corresponding estimates that are based on several response combination rules suggested in the seismic design codes and in the literature. In contrast to current seismic code design procedures, the newly proposed methodology provides consistent safety levels for different building properties and different seismic hazard conditions. Copyright © 2012 John Wiley & Sons, Ltd.
Design method and behavior factor for steel frames with buckling restrained braces
Authors: Bosco Melina , Marino Edoardo M. 
Published: October 2012

SUMMARYBuckling restrained braces (BRBs) are very effective in dissipating energy through stable tension–compression hysteretic cycles and have been successfully experimented in the seismic protection of buildings. Their behavior has been studied extensively in the last decades and today the level of performance guaranteed by these devices and the technological constrains that have to be fulfilled to optimize their behavior are well known. Furthermore, several companies in the world have developed their own BRBs and are now producing them. In spite of this, many seismic codes (for instance, the EuroCode 8) do not stipulate provisions for the design and construction of earthquake‐resistant structures equipped with BRBs. This discourages the structural engineering community from using these devices and seriously limits their use in structural applications. In this paper a procedure for the seismic design of steel frames equipped with BRBs is proposed. Furthermore, the paper presents a numerical investigation aimed at validating this design procedure and proposing the value of the behavior factorqthat should be used for this structural type. To this end, a set of frames with BRBs is first designed by means of several values ofq. Then, the obtained frames are subjected to a set of accelerograms compatible with the elastic response spectrum considered in design. The seismic response of the frames is determined by nonlinear dynamic analysis and represented in terms of the ductility demand of BRBs and the internal force demand of nondissipative members (beams and columns). Finally, the largest value ofqthat leads to acceptable seismic performance of the analyzed frames is assumed as adequate. The value ofqis given in the paper as a continuous function of the assumed ductility capacity of the BRBs. Copyright © 2012 John Wiley & Sons, Ltd.
Isolated human/animal stratum corneum as a partial model for 15 steps in percutaneous absorption: emphasizing decontamination, Part I
Authors: Hui Xiaoying , Lamel Sonia , Qiao Peter , Maibach Howard I. 
Published: October 2012

ABSTRACTSince the advent of World War II, governments and laboratories have made a concerted effort to improve prophylactic and therapeutic interventions counteracting cutaneously directed chemical warfare agents (CWA), and by inference, common industrial and consumer dermatotoxicants. In vitro percutaneous penetration assays, first utilized by Tregear in the 1940s and presently in various modifications, have been fundamental to this effort. Percutaneous penetration, often considered a simple one‐step diffusion process, consists of at least 15 steps. The first part of this review covers the initial steps related to absorption and excretion kinetics, vehicle characteristics, and tissue disposition. Importantly, the partitioning behavior and stratum corneum (SC) diffusion by a wide physicochemical array of compounds shows that many compounds have similar diffusion coefficients determining their percutaneous absorption in vivo. After accounting for anatomical SC variation, the penetration flux value of a substance depends mainly on its SC/vehicle partition coefficient. Additionally, the SC acts as a ‘reservoir’ for topically applied molecules and application of tape stripping has been found to quantify the chemical remaining in the SC which can predict total molecular penetration in vivo. Decontamination is of particular concern and even expediting standard washing procedures after dermal chemical exposure often fails to remove chemicals. This overview summarizes knowledge of percutaneous penetration extending insights into the complexities of penetration, decontamination and potential newer assays that may be of practical importance. Copyright © 2012 John Wiley & Sons, Ltd.
Establishment of transactivation assay systems using fish, amphibian, reptilian and human thyroid hormone receptors
Authors: Oka Tomohiro , Mitsui‐Watanabe Naoko , Tatarazako Norihisa , Onishi Yuta , Katsu Yoshinao , Miyagawa Shinichi , Ogino Yukiko , Yatsu Ryohei , Kohno Satomi , Takase Minoru , Kawashima Yukio , Ohta Yasuhiko , Aoki Yasunobu , Guillette Louis J. , Iguchi Taisen 
Published: October 2012

ABSTRACTThyroid hormones are essential for the regulation of a wide range of biological processes associated with normal development and metabolism in vertebrates. For the screening of chemicals with a potential thyroid hormone and anti‐thyroid hormone activities, we have established transient transactivation assay systems using thyroid hormone receptors (TRα and TRβ) from three frog species (Xenopus laevis, Silurana tropicalis and Rana rugosa), a fish (Oryzias latipes), an alligator (Alligator mississippiensis) and a human (Homo sapiens). In all species examined, similar transcriptional activities were found for triiodothyronine (T3: 10–11 M in TRα and 10–10 M in TRβ) and thyroxine (T4: 10–9 M in TRα and 10–8 M in TRβ). Analogs of thyroid hormone (3,5,3′,‐triiodothyroacetic acid and 3,3′,5,5′‐tetraiodothyroacetic acid) exhibited weaker activity, requiring 10‐fold higher concentrations for induction of activity when compared with T3 and T4. These results provide support for the usefulness of in vitro screening assay systems as part of an approach to test chemicals for potential thyroid hormone receptor activity. In addition, we observed that T3‐stimulated transcriptional activity of the O. latipes TRα was inhibited by 10–5 M tetrabromobisphenol A (TBBPA). In contrast, TR antagonist activities on TRα were not encountered in other species, even with TBBPA concentrations at 10–5 M. In vitro transactivation assay systems using TRs from various species can be used for the screening of chemicals with thyroid‐receptor agonist and antagonist activities. They also can be used for studies that examine evolutionary differences among species in the potency of TR activation. Copyright © 2012 John Wiley & Sons, Ltd.