bluuebunny/crossref_metadata_2025_split huggingface dataset:
Autoxidation of Cyclohexane: Conventional Views Challenged by Theory and Experiment
Authors: Hermans Ive , Nguyen Thanh Lam , Jacobs Pierre A. , Peeters Jozef 
Published: April 2005

AbstractIn spite of its industrial importance, the detailed reaction mechanism of cyclohexane autoxidation by O2 is still insufficiently known. Based on quantum chemical potential energy surfaces, rate coefficients of the primary and secondary chain propagation steps involving the cyclohexylperoxyl (CyOO.) radical were evaluated using multiconformer transition‐state theory. Including tunneling and hindered‐internal‐rotation effects, the rate coefficient for hydrogen‐atom abstraction from cyclohexane (CyH) by CyOO. was calculated to be k(T)=1.46×10−11×exp(−17.8 kcal mol−1/RT) cm3 s−1 (300–600 K), close to the experimental data. A “Franck–Rabinowitch cage” reaction between the nascent cyclohexylhydroperoxide (CyOOH) and cyclohexyl radical, products from CyOO.+CyH, is put forward as an initially important cyclohexanol (CyOH) formation channel. αH abstraction by CyOO. from cyclohexanone was calculated to be only about five times faster than that from CyH, too slow to explain all the observed side products. The α‐hydrogen (αH) abstractions from CyOH and CyOOH by CyOO. are predicted to be about 10 and 40 times faster, respectively, than the CyOO.+CyH reaction. The very fast CyOO.+CyOOH reaction proceeds through the unstable Cy−αH.OOH radical that decomposes spontaneously into the ketone (QO) plus the .OH radical; the “hot” .OH is found to produce the bulk of the alcohol via a second, “activated cage” reaction analogous to that above. It is thus shown how the very reactive CyOOH intermediate is the predominant source of ketone and alcohol, while it also leads to some side products. The α‐hydroxy‐cyclohexylperoxyl radical formed during the moderately fast oxidation of CyOH is shown to decompose fast into HO2.+cyclohexanone in a rapidly equilibrated reaction, which constitutes a smaller, second ketone source. These two fast cyclohexanone forming routes avoid the need for unfavorable molecular routes hitherto invoked as ketone sources. The theoretical predictions are supported and complemented by experimental findings. The newly proposed scheme is also largely applicable to the oxidation of other hydrocarbons, such as toluene, xylene, and ethylbenzene.
Mechanical Response Analysis and Power Generation by Single‐Cell Stretching
Authors: Micoulet Alexandre , Spatz Joachim P. , Ott Albrecht 
Published: April 2005

AbstractTo harvest useful information about cell response due to mechanical perturbations under physiological conditions, a cantilever‐based technique was designed, which allowed precise application of arbitrary forces or deformation histories on a single cell in vitro. Essential requirements for these investigations are a mechanism for applying an automated cell force and an induced‐deformation detection system based on fiber‐optical force sensing and closed loop control. The required mechanical stability of the setup can persist for several hours since mechanical drifts due to thermal gradients can be eliminated sufficiently (these gradients are caused by local heating of the cell observation chamber to 37 °C). During mechanical characterization, the cell is visualized with an optical microscope, which enables the simultaneous observation of cell shape and intracellular morphological changes. Either the cell elongation is observed as a reaction against a constant load or the cell force is measured as a response to constant deformation. Passive viscoelastic deformation and active cell response can be discriminated. The active power generated during contraction is in the range of Pmax=10−16 Watts, which corresponds to 2500 ATP molecules s−1 at 10 kBT/molecule. The ratio of contractive to dissipative power is estimated to be in the range of 10−2. The highest forces supported by the cell suggest that about 104 molecular motors must be involved in contraction. This indicates an energy‐conversion efficiency of approximately 0.5. Our findings propose that, in addition to the recruitment of cell‐contractile elements upon mechanical stimulation, the cell cytoskeleton becomes increasingly crosslinked in response to a mechanical pull. Quantitative stress–strain data, such as those presented here, may be employed to test physical models that describe cellular responses to mechanical stimuli.
Noncovalent Complexes between Dimethyl Ether and Formic Acid—An Ab Initio and Matrix Isolation Study
Authors: Sánchez‐García Elsa , Studentkowski Marc , Montero Luis A. , Sander Wolfram 
Published: April 2005

AbstractThe complexes formed by noncovalent interactions between formic acid and dimethyl ether are investigated by ab initio methods and characterized by matrix isolation spectroscopy. Six complexes with binding energies between −2.26 and −7.97 kcal mol−1 (MP2/cc‐pVTZ+zero point vibrational energy+basis set superposition erros) are identified. The two strongest bound complexes are, within a range of 0.3 kcal mol−1, isoenergetic. The binding in these six dimers can be described in terms of OH⋅⋅⋅O, CO⋅⋅⋅H, CO⋅⋅⋅H and CH⋅⋅⋅O interactions. Matrix isolation spectroscopy allowed to characterize the two strongest bound complexes by their infrared spectra.
Reliability evaluation considering customized power quality supply in FRIENDS
Authors: Mitsukuri Yuki , Kita Hiroyuki , Hara Ryoichi , Tanaka Eiichi , Hasegawa Jun 
Published: April 2005

AbstractThe authors have proposed a Flexible, Reliable and Intelligent ENergy Delivery System (called “FRIENDS”), which is a new concept for a future power distribution system. One of the most important feature of FRIENDS is to be able to manage the reliability of power supply. In this paper, FRIENDS and a conventional distribution system are compared quantitatively as to supply reliability and cost through time sequential Monte Carlo simulation. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 151(4): 25–35, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20053
Slot antenna‐coupled thin‐film warm carrier far‐infrared radiation detectors
Authors: Yasuoka Yoshizumi , Suzuki Kenji 
Published: April 2005

AbstractSlot antenna‐coupled thin‐film warm carrier devices were fabricated, and the detection properties were investigated at 94 and 700 GHz. Two‐dimensional 8 × 3 slot antenna arrays fed by a coplanar waveguide were used as the antennas. The thin‐film antennas were fabricated with a photolithographic method, and the warm carrier detectors, which have a contact area of 8 × 10−10cm2, were fabricated with an electron beam lithographic method. The experimental results indicate that the fabricated devices receive the far‐infrared radiation with antenna and rectified it with nonlinear I–V characteristic. By changing the antenna from the single‐slot antenna to the two‐dimensional 8 × 3 slot antenna array, the detected sensitivity improved by 11 dB. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 151(4): 1–6, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20083
Spindle pole fragmentation due to proteasome inhibition
Authors: Ehrhardt Anka G. , Sluder Greenfield 
Published: April 2005

AbstractDuring interphase, the centrosome concentrates cell stress response molecules, including chaperones and proteasomes, into a proteolytic center. However, whether the centrosome functions as proteolytic center during mitosis is not known. In this study, cultured mammalian cells were treated with the proteasome inhibitor MG 132 and spindle morphology in mitotic cells was characterized in order to address this issue. Proteasome inhibition during mitosis leads to the formation of additional asters that cause the assembly of multipolar spindles. The cause of this phenomenon was investigated by inhibiting microtubule‐based transport and protein synthesis. These experimental conditions prevented the formation of supernumerary asters during mitosis. In addition, the expression of dsRed without proteasome inhibition led to the fragmentation of spindle poles. These experiments showed that the formation of extra asters depends on intact microtubule‐based transport and protein synthesis. These results suggest that formation of supernumerary asters is due to excessive accumulation of proteins at the spindle poles and consequently fragmentation of the centrosome. Together, this leads to the conclusion that the centrosome functions as proteolytic center during mitosis and proteolytic activity at the spindle poles is necessary for maintaining spindle pole integrity. © 2005 Wiley‐Liss, Inc.
Pharmacogenomics in colorectal carcinomas: Future perspectives in personalized therapy
Authors: Russo Antonio , Corsale Simona , Cammareri Patrizia , Agnese Valentina , Cascio Sandra , Di Fede Gaetana , Macaluso Marcella , Bazan Viviana 
Published: April 2005

AbstractThe recent introduction of new drugs such as capecitabine, irinotecan, and oxaliplatinum has greatly improved the clinical outcome of patients with advanced/metastatic colorectal cancer. Nevertheless, some patients may suffer from the adverse drug reactions which will probably be the main cause of chemotherapy failure. The goal of pharmacogenomics is to find correlations between therapeutic responses to drugs and the genetic profiles of patients; the different responses to a particular drug are due, in fact, not only to the specific clinico‐pathological features of the patient or to environmental factors, but also to the ethnic origins and the particular individual's genetic profile. Genes which codify for the metabolism enzymes, receptor proteins, or protein targets of chemotherapy agents often present various genetic polymorphisms. The main aim of this review is to provide an overview of the known polymorphisms present in the genes which codify for factors (thymidylate synthase dihydropyrimidine dehydrogenase, uridine diphosphate (UDP)‐glucuronosyl‐transferase 1A1, enzymes implicated in DNA repair) involved in the action mechanisms of the drugs now utilized in chemotherapeutic treatment of colorectal carcinoma, such as fluoropyrimidines, irinotecan, and platinum agents. © 2005 Wiley‐Liss, Inc.
Polyamine depletion inhibits NF‐κB binding to DNA and interleukin‐8 production in human chondrocytes stimulated by tumor necrosis factor‐α
Authors: Facchini Annalisa , BorzÍ Rosa Maria , Marcu Kenneth B. , Stefanelli Claudio , Olivotto Eleonora , Goldring Mary B. , Facchini Andrea , Flamigni Flavio 
Published: April 2005

AbstractThe activation of the NF‐κB pathway by pro‐inflammatory cytokines, such as tumor necrosis factor‐α (TNFα), can be an important contributor for the re‐programming of chondrocyte gene expression, thereby making it a therapeutic target in articular diseases. To search for new approaches to limit cartilage damage, we investigated the requirement of polyamines for NF‐κB activation by TNFα in human C‐28/I2 chondrocytes, using α‐difluoromethylornithine (DFMO), a specific polyamine biosynthesis inhibitor. The NF‐κB pathway was dissected by using pharmacological inhibitors or by expressing a transdominant IκBα super repressor. Treatment of C‐28/I2 chondrocytes with TNFα resulted in a rapid enhancement of nuclear localization and DNA binding activity of the p65 NF‐κB subunit. TNFα also increased the level and extracellular release of interleukin‐8 (IL‐8), a CXC chemokine that can have a role in arthritis, in an NF‐κB‐dependent manner. Pre‐treatment of chondrocytes with DFMO, while causing polyamine depletion, significantly reduced NF‐κB DNA binding activity. Moreover, DFMO also decreased IL‐8 production without affecting cellular viability. Restoration of polyamine levels by the co‐addition of putrescine circumvented the inhibitory effects of DFMO. Our results show that the intracellular depletion of polyamines inhibits the response of chondrocytes to TNFα by interfering with the DNA binding activity of NF‐κB. This suggests that a pharmacological and/or genetic approach to deplete the polyamine pool in chondrocytes may represent a useful way to reduce NF‐κB activation by inflammatory cytokines in arthritis without provoking chondrocyte apoptosis. © 2005 Wiley‐Liss, Inc.
Extracellular acidification enhances DNA binding activity of MafG‐FosB heterodimer
Authors: Shimokawa Noriaki , Kumaki Iku , Qiu Chun‐Hong , Ohmiya Yoshihiro , Takayama Kiyoshige , Koibuchi Noriyuki 
Published: April 2005

AbstractCells are quite sensitive to a change of the extracellular pH and respond to it through detection of the H+/HCO level in extracellular fluid. However, little is known about molecular details induced by acidosis, such as intracellular pathways and gene expression. Here we describe properties of gene expression, protein interaction, and DNA binding activity of basic region leucine zipper (bZIP) transcription factor Maf and FosB during extracellular acidification. When cells were incubated with low pH medium, the expressions of small Maf proteins (MafG, MafK, and MafF) and FosB were clearly increased in an extracellular pH‐dependent manner and expressed transiently with a peak after 1–2 h after stimulation. Immunofluorescence and protein binding studies indicated that MafG was partially co‐localized with FosB in the nucleus and MafG can form heterodimers with FosB at extracellular pH 7.40. Moreover, we found that MafG–FosB complexes are able to bind to AP‐1 consensus sequence, TGACTCA. To investigate whether extracellular acidification influences to dimerization and DNA binding activity of MafG and FosB, extracellular pH of cultured cells was decreased from 7.40 to 6.80. The decrease in extracellular pH led to enhanced dimerization of MafG with FosB leading to augmentation of the DNA binding activity of the heterodimer to AP‐1 consensus sequence. Moreover, extracellular acidification induces mRNA expression of matrix metalloproteinase‐1, one of the genes that are regulated by AP‐1. These results suggest that MafG–FosB complexes are involved in transcriptional regulation in response to extracellular acidification. © 2005 Wiley‐Liss, Inc.
Circular chromatic index of graphs of maximum degree 3
Authors: Afshani Peyman , Ghandehari Mahsa , Ghandehari Mahya , Hatami Hamed , Tusserkani Ruzbeh , Zhu Xuding 
Published: April 2005

AbstractThis paper proves that if G is a graph (parallel edges allowed) of maximum degree 3, then χ′c(G) ≤ 11/3 provided that G does not contain H1 or H2 as a subgraph, where H1 and H2 are obtained by subdividing one edge of K (the graph with three parallel edges between two vertices) and K4, respectively. As χ′c(H1) = χ′c(H2) = 4, our result implies that there is no graph G with 11/3 < χ′c(G) < 4. It also implies that if G is a 2‐edge connected cubic graph, then χ′c(G) ≤ 11/3. © 2005 Wiley Periodicals, Inc. J Graph Theory 49: 325–335, 2005
Prevention of coronary artery disease in cancer patients
Authors: Jurado Javier , Thompson Paul D. 
Published: April 2005

AbstractImprovements in cancer treatment are increasing survival rates, placing cancer survivors at increased risk of coronary artery disease (CAD). Thoracic radiation as cancer therapy can accelerate the atherosclerotic process, and some older studies suggest that mediastinal radiation can increase the CAD risk two to fivefold. The management of serum lipids using diet and drugs is the cornerstone of efforts designed to reduce CAD events. The present article reviews the association between radiation and coronary disease and provides guidelines for the prevention of atherosclerotic CAD in this patient group and in the general population of cancer survivors. Pediatr Blood Cancer 2005;44:620–624. © 2005 Wiley‐Liss, Inc.
Folding pathways forinitiatorandeffectorprocaspases from computer simulations
Authors: Piana Stefano , Taylor Zoe , Rothlisberger Ursula 
Published: April 2005

AbstractThe folding pathways of procaspases 3, 7, and 8 have been studied using a Gô‐like Hamiltonian and molecular dynamics simulations coupled with a parallel tempering scheme. The folding pathways and the overall structures of procaspases 3 and 7 are similar, and are characterized by monomeric as well as dimeric folding intermediates in agreement with the available structural and thermochemical data. The folding pathway of procaspase 8, on the other hand, is characterized by a larger population of monomers and partially folded dimer intermediates, and only a relatively small population of folded dimer species. The most stable structure predicted for procaspase 8 is a dimer, in which the position of the linker is remarkably different from the one observed in procaspases 3 and 7, leading to the fact that all the contacts that stabilize the active site are essentially formed. This novel and unexpected structure provides a rationale for the observed activity of the procaspase 8 dimer, and thus could be highly relevant for the initiation of FAS‐mediated apoptosis. Proteins 2005. © 2005 Wiley‐Liss, Inc.
GSA algorithm applied to electronic structure: Hartree–Fock–GSA method
Authors: de Andrade M. D. , Mundim K. C. , Malbouisson L. A. C. 
Published: April 2005

AbstractA stochastical algorithm to investigate the real closed‐shell Hartree–Fock problem is proposed. The approach is based on a global optimization method, the generalized simulated annealing. We tested this methodology by determining the Hartree–Fock ground state of the H2, LiH, BH, Li2, OH−, FH, CO, N2, BeH2, CH2, H2O, NH3, HCHO, CH4 molecular systems using minimal, double‐zeta, and triple‐zeta bases. The main characteristic of this method is that it enables mapping the electronic hypersurface to find minima with the guarantee of finding the absolute minimum of the functional in focus. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Possible steps to the emergence of life: The [GADV]‐protein world hypothesis
Authors: Ikehara Kenji 
Published: April 2005

AbstractBased on the fact that RNA has not only a genetic function but also a catalytic function, the RNA world theory on the origin of life was first proposed about 20 years ago. The theory assumes that RNA was amplified by self‐replication to increase RNA diversity on the primitive earth. Since then, the theory has been widely accepted as the most likely explanation for the emergence of life. In contrast, we reached another hypothesis, the [GADV]‐protein world hypothesis, which is based on pseudo‐replication of [GADV]‐proteins. We reached this hypothesis during studies on the origins of genes and the genetic code, where [G], [A], [D], and [V] refer to Gly, Ala, Asp, and Val, respectively. In this review, possible steps to the emergence of life are discussed from the standpoint of the [GADV]‐protein world hypothesis, comparing it in parallel with the RNA world theory. It is also shown that [GADV]‐peptides, which were produced by repeated dry‐heating cycles and by solid phase peptide synthesis, have catalytic activities, hydrolyzing peptide bonds in a natural protein, bovine serum albumin. These experimental results support the [GADV]‐protein world hypothesis for the origin of life. © 2005 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 5: 107–118; 2005: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20037
The Ethics of Placebo‐controlled Trials: A Comparison of Inert and Active Placebo Controls
Authors: Edward Sarah J. L. , Stevens Andrew J. , Braunholtz David A. , Lilford Richard J. , Swift Teresa 
Published: April 2005

AbstractBecause of the recent and controversial example of sham surgery for the evaluation of fetal tissue transplants for Parkinson’s disease, there is renewed interest in the ethics of using “active” placebos in surgical trials, where otherwise there are no inert procedures available, and in pharmacological trials, where there are inert substances, but where patients may guess to which arm they have been allocated. This paper seeks to clarify the ethical arguments surrounding the use of active placebos in trials, and to set up a notation for assessing the ethics of trials more generally. We first establish an framework by which ethics committees can analyze such trials. We examine (1) the scientific value of the research; (2) the expected risks and benefits to individual patients, and (3) the voluntary nature of consent. We then contrast the implications of this framework for inert and active placebo‐controlled trials, respectively. In particular, we analyze their relative expected utility using three main utility factors, namely, treatment effects, placebo effects, and altruism. We conclude that, when the intervention is already widely available, active placebo trials rely more heavily on altruism than do inert placebo trials and, when the intervention is restricted, this excess reliance may not be needed. What our analysis provides is the explicit justification for the apparent caution of Institutional Review Boards or ethics committees when reviewing sham operations, especially when the expected harm is not trivial and the risk of exploitation is high.
How To Analyze an Article
Authors: Urschel John D. 
Published: April 2005

AbstractIn clinical research investigators generalize from study samples to populations, and in evidence‐based medicine practitioners apply population‐level evidence to individual patients. The validity of these processes is assessed through critical appraisal of published articles. Critical appraisal is therefore a core component of evidence‐based medicine (EBM). The purpose of critical appraisal is not one of criticizing for criticism’s sake. Instead, it is an exercise in assigning a value to an article. A checklist approach to article appraisal is outlined, and common pitfalls of analysis are highlighted. Relevant questions are posed for each section of an article (introduction, methods, results, discussion). The approach is applicable to most clinical surgical research articles, even those of a nonrandomized nature. Issues specific to evidence‐based surgical practice, in contrast to evidence‐based medicine, are introduced.
Effect of long‐term grazing on soil organic carbon content in semiarid steppes in Inner Mongolia
Authors: Cui Xiaoyong , Wang Yanfen , Niu Haishan , Wu Jing , Wang Shiping , Schnug Ewald , Rogasik Jutta , Fleckenstein Jürgen , Tang Yanhong 
Published: April 2005

AbstractTo clarify the response of soil organic carbon (SOC) content to season‐long grazing in the semiarid typical steppes of Inner Mongolia, we examined the aboveground biomass and SOC in both grazing (G‐site) and no grazing (NG‐site) sites in two typical steppes dominated by Leymus chinensis and Stipa grandis, as well as one seriously degraded L. chinensis grassland dominated by Artemisia frigida. The NG‐sites had been fenced for 20 years in L. chinensis and S. grandis grasslands and for 10 years in A. frigida grassland. Aboveground biomass at G‐sites was 21–35% of that at NG‐sites in L. chinensis and S. grandis grasslands. The SOC, however, showed no significant difference between G‐site and NG‐site in both grasslands. In the NG‐sites, aboveground biomass was significantly lower in A. frigida grassland than in the other two grasslands. The SOC in A. frigida grassland was about 70% of that in L. chinensis grassland. In A. frigida grassland, aboveground biomass in the G‐site was 68–82% of that in the NG‐site, whereas SOC was significantly lower in the G‐site than in the NG‐site. Grazing elevated the surface soil pH in L. chinensis and A. frigida communities. A spatial heterogeneity in SOC and pH in the topsoil was not detected the G‐site within the minimal sampling distance of 10 m. The results suggested that compensatory growth may account for the relative stability of SOC in G‐sites in typical steppes. The SOC was sensitive to heavy grazing and difficult to recover after a significant decline caused by overgrazing in semiarid steppes.