bluuebunny/crossref_metadata_2025_split huggingface dataset:
Peroxynitrite—An ugly biofactor?
Authors: Ascenzi Paolo , di Masi Alessandra , Sciorati Clara , Clementi Emilio 
Published: July 2010

AbstractCellular damage occurring under oxidative conditions has been ascribed mainly to the formation of peroxynitrite (ONOOH/ONOO−) that originates from the reaction of NO•with O2•−. The detrimental effects of peroxynitrite are exacerbated by the reaction with CO2that leads to ONOOC(O)O−, which further decays to the strong oxidant radicals NO2•and CO3•−. The reaction with CO2, however, may redirect peroxynitrite specificity. An excessive formation of peroxynitrite represents an important mechanism contributing to the DNA damage, the inactivation of metabolic enzymes, ionic pumps, and structural proteins, and the disruption of cell membranes. Because of its ability to oxidize biomolecules, peroxynitrite is implicated in an increasing list of diseases, including neurodegenerative and cardiovascular disorders, inflammation, pain, autoimmunity, cancer, and aging. However, peroxynitrite displays also protective activities: (i) at high concentrations, it shows anti‐viral, anti‐microbial, and anti‐parasitic actions; and (ii) at low concentrations, it stimulates protective mechanisms in the cardiovascular, nervous, and respiratory systems. The detrimental effects of peroxynitrite and related reactive species are impaired by (pseudo‐) enzymatic systems, mainly represented by heme‐proteins (e.g., hemoglobin and myoglobin). Here, we report biochemical aspects of peroxynitrite actions being at the root of its biomedical effects.
Hepatic ischaemia–reperfusion injury from bench to bedside
Authors: Bahde R , Spiegel H-U 
Published: July 2010

AbstractBackgroundVascular occlusion to prevent haemorrhage during liver resection causes ischaemia–reperfusion (IR) injury. Insights into the mechanisms of IR injury gathered from experimental models have contributed to the development of therapeutic approaches, some of which have already been tested in randomized clinical trials.MethodsThe review was based on a PubMed search using the terms ‘ischemia AND hepatectomy’, ‘ischemia AND liver’, ‘hepatectomy AND drug treatment’, ‘liver AND intermittent clamping’ and ‘liver AND ischemic preconditioning’; only randomized controlled trials (RCTs) were included.ResultsTwelve RCTs reported on ischaemic preconditioning and intermittent clamping. Both strategies seem to confer protection and allow extension of ischaemia time. Fourteen RCTs evaluating pharmacological interventions, including antioxidants, anti-inflammatory drugs, vasodilators, pharmacological preconditioning and glucose infusion, were identified.ConclusionSeveral strategies to prevent hepatic IR have been developed, but few have been incorporated into clinical practice. Although some pharmacological strategies showed promising results with improved clinical outcome there is not sufficient evidence to recommend them.
On estimating model complexity and prediction errors in multivariate calibration: generalized resampling by random sample weighting (RSW)
Authors: Xu L. , Xu Q.‐S. , Yang M. , Zhang H.‐Z. , Cai C.‐B. , Jiang J.‐H. , Wu H.‐L. , Yu R.‐Q. 
Published: July 2010

AbstractThe present paper focuses on determining the number of PLS components by using resampling methods such as cross validation (CV), Monte Carlo cross validation (MCCV), bootstrapping (BS), etc. To resample the training data, random non‐negative weights are assigned to the original training samples and a sample‐weighted PLS model is developed without increasing the computational burden much. Random weighting is a generalization of the traditional resampling methods and is expected to have a lower risk of getting an insufficient training set. For prediction, only the training samples with random weights less than a threshold value are selected to ensure that the prediction samples have less influence on training. For complicated data, because the optimal number of PLS components is often not unique or readily distinguished and there might exist an optimal region of model complexity, the distribution of prediction errors can be more useful than a single value of root mean squared error of prediction (RMSEP). Therefore, the distribution of prediction errors are estimated by repeated random sample weighting and used to determine model complexity. RSW is compared with its traditional counterparts like CV, MCCV, BS and a recently proposed randomization test method to demonstrate its usefulness. Copyright © 2010 John Wiley & Sons, Ltd.
The Trigonal Prism in Coordination Chemistry
Authors: Cremades Eduard , Echeverría Jorge , Alvarez Santiago 
Published: July 2010

AbstractHerein we analyze the accessibility of the trigonal‐prismatic geometry to metal complexes with different electron configurations, as well as the ability of several hexadentate ligands to favor that coordination polyhedron. Our study combines i) a structural database analysis of the occurrence of the prismatic geometry throughout the transition‐metal series, ii) a qualitative molecular orbital analysis of the distortions expected for a trigonal‐prismatic geometry, and iii) a computational study of complexes of several transition‐metal ions with different hexadentate ligands. Also the tendency of specific electron configurations to present a cis bond‐stretch Jahn–Teller distortion is analyzed.
Sequence, Stoichiometry, and Dimensionality Control in Porphyrin/Bis‐calix[4]arene Self‐Assemblies in Aqueous Solution
Authors: D'Urso Alessandro , Cristaldi Domenico Andrea , Fragalà Maria Elena , Gattuso Giuseppe , Pappalardo Andrea , Villari Valentina , Micali Norberto , Pappalardo Sebastiano , Parisi Melchiorre F. , Purrello Roberto 
Published: July 2010

AbstractThe use of a water‐soluble octacationic bis‐calix[4]arene with divergent cavities (BC4) as a templating agent for the assembly of a tetraanionic porphyrin (CuTPPS) has allowed the noncovalent synthesis of 2D or 3D multiporphyrin assemblies. Self‐assembly of CuTPPS and BC4 molecules proceeded under hierarchical control in a stepwise fashion to yield discrete and isolable supramolecular nanostructures containing up to 33 molecular elements (i.e., the CuTPPS/BC4 17:16 assembly, obtained in less than three hours). The formation of these species could be conveniently monitored by means of UV/Vis spectroscopy by following the absorbance of the Soret band at 412 nm. In particular, the attainment of the pivotal CuTPPS/BC4 5:4 species with a cruciform structure, as the key fork‐point intermediate for the subsequent formation of the higher 2D and 3D assemblies, has been demonstrated by light‐scattering studies and by an unequivocal synthesis of mixed‐porphyrin/calixarene 5:4 species involving the use of two different types of metallated porphyrins, namely CuTPPS and MnTPPS. The remarkable stability of these assemblies permits a stepwise synthesis that makes it possible to choose the desired porphyrin sequence.
Lithiated Fluorinated Styrene Oxides: Configurational Stability, Synthetic Applications, and Mechanistic Insight
Authors: Capriati Vito , Florio Saverio , Perna Filippo Maria , Salomone Antonio 
Published: July 2010

AbstractThe configurational stability of some lithiated fluorinated styrene oxides has been investigated. Chemical studies have shown that in ethereal solvents α‐lithiated ortho‐, meta‐, and para‐fluorostyrene oxides (2‐Li, α‐5‐Li, and α‐6‐Li) are all configurationally stable in the reaction time scale, whereas α‐lithiated ortho‐, meta‐, and para‐trifluoromethylstyrene oxides (9‐Li, 13‐Li, and 14‐Li) are configurationally unstable. Optically active oxiranyllithiums 2‐Li and 9‐Li, could be stereospecifically generated and quenched with electrophiles. The corresponding derivatives were then successfully subjected to regiospecific ring‐opening reactions with amines to give fluorinated β‐amino alcohols with a stereodefined quaternary carbinol center, which are useful synthons in medicinal chemistry. The barriers of inversion have been calculated (Eyring equation) for oxiranyllithiums 9‐Li, 13‐Li, and 14‐Li by determining the enantiomeric ratios after electrophilic quenching on aging the enantioenriched organolithium for different times in THF; in the case of 9‐Li, activation parameters have also been determined. Mechanisms that may be responsible of the racemization oxiranyllithiums 9‐Li, 13‐Li, and 14‐Li undergo once generated are also discussed.
Alkylative Carbocyclization of ω‐Iodoalkynyl Tosylates with Alkynyllithium Compounds Through a Carbenoid‐Chain Process Leading to (1‐Iodoprop‐2‐ynylidene)tetrahydrofurans and ‐cyclopropanes
Authors: Harada Toshiro , Imaoka Daisuke , Kitano Chie , Kusukawa Takahiro 
Published: July 2010

AbstractAlkylative carbocyclization reactions of ω‐iodoalkynyl tosylates with alkynyllithium compounds to give products with incorporated iodine atoms are described. Slow addition of 2‐(3‐iodoprop‐2‐ynyloxy)ethyl tosylates to 1‐alkynyllithium compounds in tetrahydrofuran at 40 °C followed by additional stirring at this temperature gives (Z)‐3‐(1‐iodoprop‐2‐ynylidene)tetrahydrofurans stereoselectively in good to moderate yields. Under similar conditions at 0 °C, 4‐iodobut‐1‐ynyl tosylates react with 1‐alkynyllithium compounds to give (1‐iodoprop‐2‐ynylidene)cyclopropanes. The carbocyclization reactions are proposed to proceed through a new carbenoid‐chain process involving the exo cyclization of a lithium acetylide intermediate and the vinylic substitution of the resulting TsO,Li‐cycloalkylidenecarbenoids (Ts=tosyl) by 1‐alkynyllithium compounds.
Dioxygenase‐Like Reactivity of an Isolable Superoxo–Nickel(II) Complex
Authors: Company Anna , Yao Shenglai , Ray Kallol , Driess Matthias 
Published: July 2010

AbstractAlthough O2 activation by metals such as iron and copper has been a matter of intensive research in the last decades, this type of chemistry for nickel systems is still in its infancy. Moreover, studies regarding the oxidizing ability of the resulting “Nin–O2” species towards exogenous substrates are scarce. In this work, we report on the reactivity of an isolable and thermally stable mononuclear superoxo–nickel compound [NiII(β‐diketiminato)(O2)] (1) towards different types of organic substrates. In addition, we have been able to prove that the β‐diketiminato ligand can undergo partial intramolecular oxidation due to close proximity between the isopropyl groups of the β‐diketiminato‐aryl and the superoxo subunits. Compound 1 performs hydrogen‐atom abstraction from O‐H and N‐H groups and most importantly it shows an unprecedented dioxygenase‐like reactivity in the oxidation of 2,4,6‐tri‐tert‐butylphenol. The latter reaction most likely occurs through the mediation of a putative [NiIII‐oxo] intermediate, affording an unprecedented oxidation product of the phenol that incorporates two oxygen atoms from a single O2 subunit. Results presented herein provide evidence of the striking oxidizing ability of dioxygen–nickel species and further support the viability to use such systems as oxidation catalysts analogous to its heavy metal congener, palladium.
Systems Chemistry Approach in Organic Photovoltaics
Authors: Würthner Frank , Meerholz Klaus 
Published: July 2010

AbstractThe common approach in organic materials science is dominated by the perception that the properties of the bulk materials are virtually determined by the properties of the molecular building blocks. In this Concept Article, we advocate for taking into account supramolecular organization principles for all kinds of organic solid‐state materials, irrespective of them being crystalline, liquid crystalline, or amorphous, and discuss a showcase example, that is, the utilization of merocyanine dyes as p‐type organic semiconductors in bulk heterojunction (BHJ) solar cells. Despite their extraordinarily large dipole moments, which are considered to be detrimental for efficient charge carrier transport, BHJ organic photovoltaic materials of these dyes with fullerenes have reached remarkable power conversion efficiencies of meanwhile nearly 5 %. These at the first glance contradictory properties are, however, well‐understandable on the systems chemistry level.
Semistate models of electrical circuits including memristors
Authors: Riaza Ricardo , Tischendorf Caren 
Published: July 2010

AbstractIn this paper we present several semistate or differential‐algebraic models arising in nodal analysis of nonlinear circuits including memristors. The goal is to characterize the tractability index of these models under strict passivity assumptions, a key issue for the numerical simulation of circuit dynamics. We show that the main model, which combines memristors' fluxes and charges, is index two. From a technical point of view, this result is based on the use of a projector along the image of the leading matrix, in contrast to previous index analyses. For charge‐controlled memristors, the elimination of fluxes yields an index one system in topologically nondegenerate circuits, and an index two model otherwise. Analogous results are also proved to hold for flux‐controlled memristors. Our framework accommodates coupling effects among resistors, memristors, capacitors and inductors. Copyright © 2010 John Wiley & Sons, Ltd.
A scalable and efficient key escrow model for lawful interception of IDBC‐based secure communication
Authors: Han Kyusuk , Yeun Chan Yeob , Shon Taeshik , Park Jonghyuk , Kim Kwangjo 
Published: July 2010

AbstractKey escrowing is one of the core technologies for the lawful interception (LI) of secure communications in the wired and wireless networks. Although many previous studies on the key escrowing have been done before, they are insufficient to be deployed in practical networks due to conflicts with the LI requirements. Moreover, there is lack of consideration on the LI of ID‐based cryptosystem (IDBC)‐based secure communication because the interest of the LI was moved to the industries and IDBC has the inherent key escrowing property. However, the inherent property of IDBC cannot prevent ‘illegal’ eavesdropping of all the communications in the networks from the law enforcement agency with the ‘legally’ obtained key. Thus, we propose a new key escrow model that satisfies the requirements of LI and overcomes the potential threats of IDBC. Our contributions enable the scalable and efficient key escrowing for the LI of secure one‐way and two‐pass communication in the mobile networks. Copyright © 2010 John Wiley & Sons, Ltd.
Distributed BLAST with relay selection for multi‐antenna AF relaying
Authors: Bahrami Hamid Reza , Le‐Ngoc Tho 
Published: July 2010

AbstractBy examining the diversity–multiplexing tradeoff (DMT) of an amplify‐and‐forward (AF) multi‐antenna multi‐relay network, a procedure to select the optimal number of relays and relay candidates is established. Subsequently, a distributed BLAST transmission scheme in conjunction with successive nulling and cancellation at destination is proposed to achieve the optimal DMT. Illustrative results indicate that the proposed method can significantly enhance the outage probability performance, and for a selected number of relays in use, the performance enhancement can be further improved by increasing the number of available relays in the AF network. Copyright © 2010 John Wiley & Sons, Ltd.
The global challenge of type 2 diabetes and the strategies for response in ethnic minority groups
Authors: Lirussi Flavio 
Published: July 2010

AbstractEthnic minorities living in high‐income countries usually exhibit a greater risk of developing diabetes along with higher morbidity and mortality rates. We evaluated the effectiveness of interventions to improve glycaemic control in ethnic minority groups. Results of major controlled trials, systematic reviews and meta‐analyses were included in the review. Only 1/47 studies addressing diet and exercise interventions reported details on the ethnicity of the studied population. Self‐management education was successful if associated with increased self‐efficacy; delivered over a longer period; of high intensity; culturally tailored; and when using community educators. Strategies adopted in community‐gathering places, family‐based, multifaceted, and those tackling the social context were likely to be more effective. A positive relationship was found between social support and self‐management behaviour as well as quality of life, but there is little evidence about the impact of organizational changes within health‐care services on diabetes control. More research is needed to strengthen the evidence on effective strategies for response to diabetes in ethnic minorities. Also, there is a need to take into account diabetes beliefs and communication difficulties, as well as potential protective factors. Globally, many health‐care systems are inadequately equipped to improve diabetes prevention and disease outcomes in these communities. Copyright © 2010 John Wiley & Sons, Ltd.
Type 2 diabetes mellitus and obesity in sub‐Saharan Africa
Authors: Tuei Vivian C. , Maiyoh Geoffrey K. , Ha Chung‐Eun 
Published: July 2010

AbstractWhile communicable diseases such as human immunodeficiency virus/acquired immune deficiency syndrome, malaria, and tuberculosis have continued to pose greater threats to the public health system in sub‐Saharan Africa (SSA), it is now apparent that non‐communicable diseases such as diabetes mellitus are undoubtedly adding to the multiple burdens the peoples in this region suffer. Type 2 diabetes mellitus (T2DM) is the most common form of diabetes (90–95%), exhibiting an alarming prevalence among peoples of this region. Its main risk factors include obesity, rapid urbanization, physical inactivity, ageing, nutrition transitions, and socioeconomic changes. Patients in sub‐Saharan Africa also show manifestations of β‐cell dysfunction and insulin resistance. However, because of strained economic resources and a poor health care system, most of the patients are diagnosed only after they have overt symptoms and complications. Microvascular complications are the most prevalent, but metabolic disorders and acute infections cause significant mortality. The high cost of treatment of T2DM and its comorbidities, the increasing prevalence of its risk factors, and the gaps in health care system necessitate that solutions be planned and implemented urgently. Aggressive actions and positive responses from well‐informed governments appear to be needed for the conducive interplay of all forces required to curb the threat of T2DM in sub‐Saharan Africa. Despite the varied ethnic and transitional factors and the limited population data on T2DM in sub‐Saharan Africa, this review provides an extensive discussion of the literature on the epidemiology, risk factors, pathogenesis, complications, treatment, and care challenges of T2DM in this region. Copyright © 2010 John Wiley & Sons, Ltd.
Improvement of particle swarm optimization based on the repetitive search guideline
Authors: Hiraoka Sodo , Okamoto Takashi , Aiyoshi Eitaro 
Published: July 2010

AbstractParticle Swarm Optimization (PSO), which has attracted a great deal of attention as a global optimization method in recent years, has the drawback that continuous search based on its excellent dynamic characteristics cannot be performed stably until the end of computation due to its very strong tendency to convergence. In this paper, we propose a ARepetitive Search Guidelinewhich differs from the common guidelines in the improved methods which have since been proposed and by which the continuous search in PSO is achieved without losing PSO's excellent dynamic characteristics due to repetitive search in a promising area where the objective function values are expected to be small. We consider four improved methods based on the proposed guidelines, then confirm their effectiveness by application to 100‐variable multipeaked benchmark problems. 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 173(2): 42–54, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ eej.20964
A new weakly basic amino‐reactive fluorescent label for use in isoelectric focusing and chip electrophoresis
Authors: Schulze Philipp , Link Martin , Schulze Marcel , Thuermann Sebastian , Wolfbeis Otto S. , Belder Detlev 
Published: July 2010

AbstractIn this study, we present a novel amino‐reactive fluorescence marker (referred to as UR‐431), which is well suited for electrophoretic techniques. A main feature of this marker is its weakly basic behavior when conjugated to analytes. Labeled primary amines exhibit a positive net charge and accordingly a cathodic mobility below a pH of 2.4. The label features a pH‐independent fluorescence emission and is thus very interesting for electrophoretic applications such as IEF. The absorption maximum of this yellow daylight chromophore is at 431 nm, whereas fluorescence emission peaks at 537 nm (quantum yield≈0.1). The label was successfully conjugated to amines, peptides and proteins and separated via CE and MCE. The on‐chip detection limit of labeled lysine using a mercury‐lamp‐based fluorescence microscope was determined as 12 nM. An important feature of the new label is that it effects only a subtle change of the pI of proteins compared with common anionic labels, e.g. FITC. pI values of proteins were investigated by comparing native proteins and labeled proteins in CIEF. UR‐431 was also applied to sensitive detection of amines and peptides in MCE.
Throughput enhancement through femto‐cell deployment
Authors: Bharucha Zubin , Haas Harald , Saul Andreas , Auer Gunther 
Published: July 2010

AbstractThis paper studies the impact of a femto‐cell underlay deployment that shares radio frequency resources with urban macro‐cells. Due to their random and uncoordinated deployment, femto‐cells potentially cause destructive interference to macro‐cells andvice versa. On the other hand, femto‐cells promise to substantially enhance the spectral efficiency due to an increased reuse of radio resources. The performance of networks with indoor Home Evolved NodeB (HeNB) deployment is compared to a system where all users, including indoor users, are served by the outdoor macro Evolved NodeB (eNB). In addition, the impact of closed‐access and open‐access femto‐cell operation is examined. It is demonstrated that significant capacity gains can be achieved through such HeNB deployment, regardless of whether closed‐access or open‐access is considered. Results clearly indicate that the capacity gains through femto‐cell deployment outweigh the additional interference they introduce. Copyright © 2010 John Wiley & Sons, Ltd.